Subatomic Particles and the Human Buffer System

Paper Subatomic Particles There are three unique kinds of subatomic particles. The core of an iota is made out of two distinct sorts of particles, protons and neutrons. Protons are decidedly charged particles. The heaviness of a proton is one amu. Protons are situated inside the core and can't move from inside the core. The proton image is . Neutrons are additionally situated inside the core and have a nonpartisan charge. Neutrons are likewise one amu like protons. Neutrons can move from the core of an iota making a particle an isotope. The neutron image is .Electrons are situated outside the core in vitality levels. Electrons have a negative charge and weigh roughly 1/2000th of an amu. The weight is practically unimportant. Electrons can change in an iota making cations and anions. Cations are a positive charge when an iota loses an electron. Anions are a negative charge when a molecule increases an electron. These are the three subatomic particles that make up an iota and their qua lities. Exposition Buffer System Buffers oppose pH vacillations. A cradle is made out of a frail corrosive and a powerless base. Carbonic corrosive is the powerless corrosive and bicarbonate is the feeble base.When an answer is to acidic the pH is low and there are to numerous hydrogen particles. The low pH level is brought about by to numerous hydrogen particles. To make an answer impartial you would need to make progressively corrosive my joining bicarbonate and hydrogen particles to frame carbonic corrosive. By doing this you are lessening the quantity of hydrogen particles in an answer. At the point when an answer is to fundamental the pH is high and the quantity of hydrogen particles is low. The pH is high on the grounds that the arrangement has a low number of hydrogen particles. To make an answer unbiased in an essential arrangement you have to separate carbonic corrosive expanding the quantity of hydrogen particles.

Healthcare Finance in The United States of America Free Essays

In United States the Congress had passed the Medicare Prescription Drug, Improvement and Modernization Act of 2003 or MMA and with this forced a stoppage for year and a half on the beginning of new doctor claimed forte clinics. Simultaneously, they likewise needed to realize the position with respect to specific issues of doctor possessed heart, orthopedic and careful forte medical clinics through MedPAC. The group visited locales, made lawful investigation and met the offer proprietors in these emergency clinics lastly introduced a report to the Congress. We will compose a custom paper test on Human services Finance in The United States of America or on the other hand any comparative theme just for you Request Now It had additionally experienced the cost reports got from Medicare and inpatient cases of 2002, which was the latest around then. This will normally shape the premise of such medical clinics being allowed or not. (Doctor possessed claim to fame medical clinics) The discoveries of this board of trustees indicated that:- Doctor possessed medical clinics for the most part treated patients who had less serious issues and focused on explicit determination related gatherings and the explanation behind both of this was these were relied upon to be more beneficial than different patients. These emergency clinics don't treat the same number of Medicaid patients as network emergency clinics. Concerning expenses of patients in these emergency clinics for the patients, the Medicare patients didn't get advantages of lower costs however the inpatients had shorter times of remain. There was no calculable effect of doctor possessed strength emergency clinics on the network medical clinics as observed in 2002, and there was likewise no effect on the budgetary exhibition of the network medical clinics. The vast majority of the distinctions in benefit can be amended by improving the planned patient framework for inpatients that are made by Medicare. Along these lines as per the discoveries there are not significant contrasts between the network clinics and doctor possessed claim to fame medical clinics as far as expenses or ability for administrations. (Doctor claimed forte emergency clinics) Contrasts among sorts of emergency clinics: We will make correlation of the emergency clinics in India and USA. In India, aside from the administration emergency clinics, there are various enormous medical clinics run by trusts or huge organizations. In the city of Bombay or Mumbai, the clinics named Jaslok or Hinduja are controlled by trusts and Wockhardt Heart Hospital is controlled by a significant pharmaceutical organization. In any event, when the medical clinic has been advanced by a doctor, still the emergency clinic is run like an enterprise as is found on account of Apollo Hospitals. There is presently another clinic named as Asian Heart Hospital in Bombay which has been advanced by a doctor group and they have an enormous stake in the emergency clinic. The group of doctor is driven by one Mr. Panda who is currently the CEO of the medical clinic. These doctors have all contributed their own assets, and to get more assets, they have even requested more commitments from different doctors who are presently not inhabitant in India. The emergency clinic is the aftereffect of an arrangement by these doctors in 1993-94. The clinic took around 10 years to finish. In this way one ought to understand that a medical clinic sets aside a long effort to come to fruition up. (Specialists in arms) The most concerning issues in the administration of clinics originate from doctors and prestigious doctors are looked for empanelment by emergency clinics. The doctors at that point persistently power the emergency clinics to update their foundation and furthermore charge overwhelming expenses from the patients. Toward the finish of the administrations by the doctors, it is they who get the greatest returns. It is additionally hard to hold the doctors as they leave at the soonest opportunity, and this announcement is from one of the advertisers of the medical clinic, GW Capital. They are currently putting cash in the idea of doctor oversaw private emergency clinics. This brought about its venture of Rs 150 million or around 3 million dollars in purchasing a 26 percent stake in another medical clinic bunch in Hyderabad, in 2000 called the Care Group. That gathering has extended quick and now has over a 1000 beds in its tasks in six focuses. (Specialists in arms) Thus the expenses of the medical clinics will require around 12 million dollars for a 1000 bed activity. Simultaneously, not all clinics are made considering cash and there are emergency clinics in Chennai or Madras in India which have 150 doctors, 500 attendants and 371 Para-clinical staff. The whole group works inside a financial plan of Rs 120 million or 2.4 million dollars. (Mending Ministry of the Madras Diocesan Medical Board) This emergency clinic is controlled by a strict strategic its goal is to offer support to the individuals and this emergency clinic wouldn't like to bring in cash, yet run at make back the initial investment costs. In United States, during 2002 there were 48 emergency clinics saw as doctor possessed medical clinics. Of them 12 were heart clinics, 25 were orthopedic emergency clinics and 11 were careful medical clinics. These clinics are commonly little with normal limits of orthopedic emergency clinics being 16 beds, the careful claim to fame medical clinics being 14 beds and heart emergency clinics are the biggest with normal limit being 52 beds. The general states of these medical clinics are not undeniable as they don't have crisis offices, while 93 percent of the network emergency clinics have crisis offices. The purpose behind presence of these emergency clinics is the doctor authority over the medical clinics. (Doctor claimed forte emergency clinics) simultaneously, one of these medical clinics has been named as one of country’s top 100 heart medical clinics. (Parkwest Medical Center) Money related situation of private medical clinics: As indicated by accessible reports, the private medical clinics are in a situation to take on patients who are fit for paying for them, and not take on patients who need to rely upon oversaw care associations. This expands the earnings of the clinics by 20 to 50 percent. This decreases the expense of a detour medical procedure at one of the emergency clinics in India, Care to about Rs 80,000 or $1,700. The expense in India is higher by around 30 to 40 percent in corporate medical clinics. Indeed, even the new clinic, Asian Heart has anticipated a money make back the initial investment during the second year of tasks, and before the second's over year it hopes to deliver a 15 percent profit to the speculator. Along these lines on a speculation of $50 million, the profits would be $7.5 million from the subsequent year. (Specialists in arms) The situation in United States is the equivalent, and despite some private claim to fame emergency clinics not having made any appropriations to investors, the examination indicated that the edge in these medical clinics was around 13 percent in 2002 when contrasted with 3 to 6 percent that was seen for network medical clinics. (Doctor possessed claim to fame emergency clinics) The benefits of doctor possessed claim to fame clinics: To discover this angle out, there were conversations with the doctors who were putting resources into these clinics. The cardiologists and specialists need to concede their patients, play out the necessary strategies and have the patients recoup with least aggravation. They accept that network medical clinics can't coordinate their administrations as those emergency clinics have an assortment of administrations and missions that they need to embrace. The immediate control by the doctors help to build profitability through less unsettling influences to the timetables in working room which originate from the crisis cases that occur, diminishing the vacation between activities between two distinct medical procedures and this is because of tidying up the working room all the more productively, expanded capacity to work between two working rooms in any event, when the working rooms are hindered because of some other work and better efficiencies through direct control of working room staff. As referenced before, they additionally prefer to shape claim to fame medical clinics as they have increments in salary. There is some expansion because of efficiency, however they can gather a portion of the benefits from the office for themselves and other related doctors. They focus on offering types of assistance that are beneficial, on treating patients who are less wiped out and in this manner progressively gainful. (Doctor possessed strength medical clinics) Even in India a similar circumstance exists and a large portion of the doctors who have now begun creating emergency clinics have been cooperating before, and one of the fundamental points is to expel the weight from oversaw human services frameworks that they need to confront something else. There is presently a particular change in the development of medical clinics and new emergency clinics are being framed by doctors. The absolute expenses have been talked about somewhat, yet without the interest of doctors, the clinics are probably not going to be fruitful. The most effective method to refer to Healthcare Finance in The United States of America, Essay models

Cognitive Distortions and Eating Disorders

Cognitive Distortions and Eating Disorders Eating Disorders Symptoms Print Cognitive Distortions and Eating Disorders By Susan Cowden, MS facebook linkedin Susan Cowden is a licensed marriage and family therapist and a member of the Academy for Eating Disorders. Learn about our editorial policy Susan Cowden, MS Updated on February 24, 2020 Olga Batishcheva/Getty Images More in Eating Disorders Symptoms Treatment Diagnosis Awareness and Prevention Cognitive distortions  are inaccurate or exaggerated thought patterns or thoughts. They are sometimes also referred to as dysfunctional, negative, or automatic thoughts. Cognitive distortions about food, weight, and body image are a core symptom of both  anorexia nervosa  and  bulimia  nervosa and  are experienced by many other people as well. Treatment for eating disorders usually prioritizes weight restoration, resumption of regular eating patterns, and other behavioral changes. Later on, treatment also commonly addresses problematic thinking patterns. 10 Common Cognitive Distortions Different Kinds of Cognitive Distortions Different patterns of problematic thoughts are commonly experienced by people with eating disorders. Recognizing, challenging, and changing negative thought patterns is one of the main components of  cognitive behavioral therapy (CBT). Learning the patterns of cognitive distortions through CBT or another type of therapy can help you learn to recognize them. Keep in mind that identifying the exact type of problematic thinking you are experiencing is not the critical componentâ€"you just want to become more aware of them. Here are a few of the most common cognitive distortions experienced by people with eating disorders. Shoulds Shoulds  are demands  that you place on yourself such as thinking I should have done better. or I must be perfect. Regarding eating disorders, shoulds might include thoughts about needing to exercise, what foods should/shouldnt be eaten, or what you should weigh. All or Nothing Thinking This type of thinking is sometimes known as black and white thinking. It contributes to perfectionistic tendencies because it causes you to believe that something is either completely okay/right or completely wrong. When you have an eating disorder, this can crop up when you have a plan to adhere to a specific dietary ruleâ€"you may feel as if the day is completely ruined when you eat something ‘wrong’ or the scale reads something other than what you’d like to see. How to Overcome All-Or-Nothing Thinking Overgeneralizing Overgeneralizing is like or nothing thinking. It occurs when you believe that a negative experience or situation describes your life completely. An example might be believing that a relapse means that you will never recover fully, rather than seeing it as a temporary setback. Catastrophizing Any time you believe that a situation is so bad that you simply cannot survive it, you may be catastrophizing about the situation or its outcome. For example, you might believe that if you weighed a certain amount, no one would like you or your self-worth would plummet. You might also believe that your weight will rise based on what you have eaten at one meal or snack. Labeling Labeling is a distortion that attempts to place people and things  in  specific categories. Examples of this might be “I’m such a loser, “I have no  self-control, or “These foods will make me gain weight.” Typically, these labels are overly simplistic and are unable to describe all of the complexities humans possess. Rejecting the Positive  Many cognitive distortions focus only on the negative aspects of something and reject anything positive. For someone with an eating disorder, this type of distortion may focus only on criticizing mistakes  or focus only on the caloric content of food instead of on the nutrition and energy in the food. The Power of Positive Thinking Unfavorable Comparisons Many people with eating disorders compare the way they look, what they weigh, and how much they eat to the people around them. These comparisons tend to always be negative. For instance, if you think someone weighs less than you do, the eating disorder thoughts may focus on how you ‘should’ also weigh less. However, if you believe that you weigh less, the eating disorder thoughts focus on keeping you at the lower weight. Blaming and Personalizing Blaming and personalizing are two sides of the same issue. When someone personalizes, they believe that everything is their fault, whereas when someone blames others, they believe that everything is someone else’s fault. The truth likely lies somewhere in the middleâ€"and sometimes it is no one’s fault that something has happened. How to Track and Change Your Cognitive Distortions Keep a record of thoughts that occur before binges or purges and/or times you feel upset. See if they follow any of the patterns described above. Once you are aware of your cognitive distortions you can learn some strategies for managing and modifying cognitive distortions.  A cognitive-behavioral therapist can also help you to run experiments to test the validity of these thoughts. How Cognitive Restructuring Works

Analysis Of Othello By William Shakespeare - 1436 Words

Rasheed Patrick Ms. Milliner EES21QH-01 01/17/17 Final Paper In Othello every character has their own personalities that makes them the person they are. In Othello there are characters that show true grit, a fixed mindset, and a growth mindset. Each characters are different which makes the book even more interesting. True grit means to endure and push through to do something better no matter what it takes. An example of grit is studying for a long period of time for a test and enduring the amount of work that must be completed. The definition of mindset is the established set of attitude held by someone. There are two other types of mindset as well. There is growth mindset and fixed mindset. Growth mindset is when the person isn t†¦show more content†¦Even though Iago did not become lieutenant he still believes he is worth more than what others believe his is. This shows that Iago has a growth mindset and still believe he can be better than Cassio. For example, Carol Dweck states, â€Å"When they are not coping with failure, they fe el just as worthy and optimistic - and bright and attractive - as people with the growth mindset†(Dweck 53).This shows that Iago is a very determined antagonist in the story and won t give up until he gets what he feels he deserves. He also proves he has a growth mindset in act one scene one. In act one scene one Iago continues to talk to Roderigo about the lieutenant situation. Iago then states, â€Å"O, sir, content you. I follow him to serve my turn upon him. We cannot be truly followed. You shall mark Many a duteous and knee-crooking knave That, doting on his own obsequious bondage, Wears out his time, much like his master’s ass, For naught but provender; and when he’s old, cashiered†(Act one scene one). Iago states that he is only working with Othello to take advantage of him. Iago plans on working under Othello until he is able to use him to become someone far more bigger than he is. Othello is the protagonist of the story, he is married to Desdemona and is general of the army in Venice. Othello has a growth and fixed mindset simply because if he falls he’ll try again to do better. Othello shows having aShow MoreRelatedOthello Analysis : Othello By William Shakespeare1115 Words   |  5 PagesRiley Thompson Professor Grill LIT 200 2 November 2014 Othello Analysis Assignment Othello, a play that was written in 1604 by William Shakespeare, is an example of a type of story called a â€Å"tragedy.† Throughout the course of the work, Othello proves himself to be very easily misled, despite his heroic status. This causes him to lose his ability to make good judgments and decisions. Even though Othello had a reputation as a hero, he ends up being one of the most gullible characters in the play whenRead MoreAnalysis Of Othello By William Shakespeare Essay2413 Words   |  10 Pagesprocess, such as a process known as Classical Conditioning. Mind manipulation has been presented by villains throughout movies, novels, and even plays. The play Othello, written around 1603 by William Shakespeare, with the villain character Iago, is characterized as a jealous, hubris, sinister, crafty, and manipulative being. William Shakespeare has managed to write a tragic play where he used Iago’s malicious words to provide early Classical Conditioning, to cloud Ot hello’s mind of critical thoughtsRead MoreAnalysis Of Othello By William Shakespeare1579 Words   |  7 Pagesdiscriminated against due to your race? In Othello by William Shakespeare the theme of race is evident through out the play and is a very critical aspect towards the plot. Since Othello has a strong sense of self he is able to counter-balance the overt racism he is faced with in the beginning because he is respected and has high stature as a war general. Him and his wife lived happily without worrying what others thought of their bi-racial marriage. But, when Othello hears rumors of his wife’s possibleRead MoreAnalysis Of Othello By William Shakespeare1240 Words   |  5 PagesRationale In Part Four of the course, Critical Study, we studied Shakespeare’s tragedy, Othello. This is a play that comprises of enduring themes of love, betrayal, jealousy, appearance versus reality, racism, and revenge. I chose to write a diary for this play because we are only presented with the facade of these characters. Throughout the play, the audience is left to wonder what goes on behind the scenes. And the only way to achieve this is to put ourselves in their shoes in order to experienceRead MoreAnalysis Of Othello By William Shakespeare865 Words   |  4 PagesHandkerchief William Shakespeare is a famous writer had written lot of poetry, stories, dramas etc. In his drama, he usually has a sad ending. He introduces a clue that diverts a character’s mind and thought. One of his plays named â€Å"Othello† he introduces a handkerchief as a clue that had diverted different characters’ thoughts. That handkerchief changed from a love token into a source of suspicion in Othello’s mind. In this story, main character named Othello, who gave that handkerchief to his wifeRead MoreAnalysis Of Othello By William Shakespeare1505 Words   |  7 PagesQuanisha Taylor Dr. Traylor English 1102 16 November 2015 Sadistic Motives In William Shakespeare’s play Othello Iago has the ability to charm and convince people of his loyalty and honesty. Iago immediately introduced his malicious desire for revenge, but he had no proven reason for his actions. Throughout the play Iago devises a devious plan to convince the other characters of his cunning contrivance. Iago treats others as the fool with no intentions of caring about their feelings. Behind hisRead MoreAnalysis Of Othello By William Shakespeare1575 Words   |  7 Pagesdiscriminated against due to your race? In Othello by William Shakespeare the theme of race is evident through out the play and is a very critical aspect towards the plot. Since Othello has a strong sense of self he is able to counter-balance the overt racism he is faced with in the beginning because he is respected and has high stature as a war general. Him and his wife lived happily without worrying what others thought of their bi-racial marriage. But, when Othello hears rumors of his wife’s possibleRead MoreAnalysis Of Othello By William Shakespeare1090 Words   |  5 Pagesyears, women have been seen as inferior and weaker than men, while men are seen as superior and stronger than women. However, the word strong doesn t measure their physical strength, but by their strength to ignore societies standards. Othello by William Shakespeare takes place during the late 16th century a time in which women didn’t have a voice and were expected to be obedient and chaste. Although this was the case for many women, Emilia is a strong character because she stood up for what she believedRead MoreAnalysis Of Othello By William Shakespeare1378 Words   |  6 PagesEES21GH-02 01/20/17 Final paper Throughout the play Othello by William Shakespeare, we sit in on the life of an African American military commander, or Moor, who was deceived by a jealous under officer named Iago. Iago’s only motive for deceiving the Moor was animosity because Othello did not promote him to Lieutenant. With the help of a passive man named Roderigo, Iago was able to convince Othello that his wife had cheated on him with the man Othello did promote to Lieutenant, named Cassio. After convincingRead MoreAnalysis Of Othello By William Shakespeare Essay1606 Words   |  7 PagesThe theme of power is explored in various ways throughout ‘Othello’, Shakespeare uses the vulnerability of characters’ flaws to allow power shifts to occur through manipulation. The Elizabethan value consensus highlights the difference in gender roles, with societal expectations being defined by the divine order. The limitations of social mobility provide a strong platform for the theme of power to b e embedded upon, with characters such as Desdemona and Emilia representing the struggle that women

Philosophy from the Female Perspective Essay - 2206 Words

Virginia Held is a modern day philosopher with theories on the feminist view in philosophy. All of the major philosophers have always written from the male perspective. As far back as the Bible, most major writings have always been geared towards men. They were considered the predominant species from the creation of Eve from Adams rib. Many philosophers have described worlds that were based upon men, war, and reason. These theories were based on the experience of man. Women were too emotional and simple to understand the complexity of the world. Philosophers have always focused on mans influence and role in the world. These philosophers have downplayed or ignored the role of women in history. This paper will discuss the gender†¦show more content†¦Throughout history, the role of women has changed. They have evolved into thinking and analytical creatures that possess the ability to make decisions and govern their own lives. Feminists characteristically begin w ith different concerns and give different emphases to the issues we consider than do non-feminist approaches. (Morality and Moral Controversies, pg. 89) Feminism is reshaping the worlds moral and theoretical beliefs. Held feels that in order for the world to truly be rational, the female perspective and experience must be taken into account. Thus far, philosophy has been shaped around the belief that man is the more superior of the sexes. While man has always been associated with rational ideas, it has been believed that in order to be rational, man must break free of the feminist ideals and emotion. Genevieve Lloyd has written about the man of reason. In this, she has said that even though times have changed, the man of reason has remained the same. This would be the rejection of all that is feminine. Until recent times, it has been believed that feminism was irrational and the opposite of reason. From the beginnings of philosophical thought, femaleness was symbolically a ssociated with what Reason supposedly left behind - the dark powers of the earth goddesses, immersion in unknown forces associated with mysterious powers. The early GreeksShow MoreRelatedAnimal Mating And The Development Of Behavioral Characters1111 Words   |  5 PagesMarlene Zuk observes the disputes that arise when nature is explained among various palliative, humanizing, and political viewpoints in Sexual Selections: What We Can and Can’t Learn about Sex from Animals. She has discovered that biologists and sociologists and the society persist to view the behavior of animal as human beings’ behavior. We elucidate such interpretations for our own egoisms, and that results in us being unaware of what’s actually happening with the animals themselves. In this bookRead More Feminist Theory - There is No One Definition of Woman Essay1400 Words   |  6 Pagesencompassing the inherently different experiences of non-white/non-Anglo women â€Å"much of the theory has failed to be relevant to the lives of women who are not white or middle class† (I bid. 21). This displacement of a large population of the world’s women from feminist theory is extremely threatening to the development of a woman’s voice, in so far as this voice is key to fighting the battles that feminism sets out to fight: the end of repression, the establishment of opportunity, and creation of recognitionRead MoreWestern and Eastern Cosmologies1423 Words   |  6 Pagesbranch of philosophy dealing with the origin and general structure of the universe, with its parts, elements, and laws, and especially with such of its characteristics as space, time, causality, and freedom (Drew).† The second definition of cosmology is: â€Å"the branch of astronomy that deals with the general structure and evolution of the universe (Drew).† Therefore, cosmology is the study of the origin of the universe, and it can be interpreted through a philosophical or scientific perspective. But forRead MoreLet the Punishment Fit the Crime in the State of Calif ornia1301 Words   |  6 Pages190.4 to be true† (CA Codes). I was disconcerted with the fact that PC §190.4(14) was an enhancement that had been examined. This implied that my actions may have carried a tortuous value (CA Codes). I recognize the factors of my being a young, white female with no previous criminal record as likely having carried a heavily weighted value. Ultimately, I was sentenced (punished) by the county of Sacramento to 25 years to life with the possibility of parole. This was the preferred sentence, in my opinionRead MoreUtilitarian Perspective On Feminism1563 Words   |  7 PagesA Utilitarian Perspective on Women’s Rights John Stuart Mill’s discussion of the subjection of women leaves many scholars regarding him as one of the first feminist philosophers of his time. His work analyzes and questions the everyday perspectives on women’s rights, and challenges common societal notions. Many philosophers today look to his work for a variety of reasons; some applaud his work for being ahead of it’s time. Others dismiss it, claiming that it’s flawed due to personal attachment.Read MoreThe Ideas Of Race And Racialized Categories From The Minds830 Words   |  4 PagesPhilosophy is all about exploring the different perspectives people have in their minds. This was my initial thought of what philosophy was. I knew that many of the topics that we discussed in this class would stimulate my mind. Learning new theories that contribute to the better understanding of my history is something that I enjoy greatly. No matter the level of difficulty of the subject matter, I enjoy learning wha t I consider to be reality. Discussing not only where the ideas of race and racializedRead MoreArticle Analysis : Performative Acts And Gender Constitution1387 Words   |  6 Pagesidentity repeatedly constructed throughout time. Butler is trying to show us a feminist perspective of sex and gender. She attempts to follow Beauvoir’s path in a fight against society norms. To understand Butler’s work, it is important to know who Butler is. Judith Butler was born on February 24, 1956 in Cleveland, Ohio. She attended Bennington College and Yale University afterwards where she studied philosophy, receiving her B.A. in 1978 and her Ph.D. in 1984. She then taught at Wesleyan UniversityRead MorePsychological And Physical Aspects Of Science1683 Words   |  7 Pages Philosophy of science has long studied the psychological and physical aspects of scientific knowledge, where situational factors inescapably influence researchers and outcomes of scientific studies and knowledge in general (reference). This idea is reflective in philosophy by the term ‘situated knowers’ (Stamford), broadly explained by considering how the same object can be interpreted differently by others in terms of their individual relation to it. An explanation of an object is reflective ofRead MoreThe Value Of Philosophy And Its Influence On Society1271 Words   |  6 PagesThe value of philosophy lies in its ability to influence a society and/or provide wisdom to others. Often philosophy is mistakenly thought of as inadequate compared to science. Breakthroughs in medicine allow us to live healthier and longer lives; While technological advances allow for a more connected and convenient world. Despite popular belief, philosophy is just as evident as science in advancing society. Contrary to the empirical measurement’s that science provides, philosophy provides wisdomRead MoreFeminism in Chinese Buddhism: Patriarchy versus Non-Duality1271 Words   |  5 PagesBuddhism is a religion founded on non-differentiation. One of the goals of meditation is to view all things dispassionately, without becoming attached to the notion of things as good or bad. Material existence, including the body (whether it is male or female) i s inherently impermanent. The issue of womens religious statuses and roles remains more ambiguous and controversial in Buddhism than it is for other world religion†¦ some suggest that the core of Buddhist tenets contains egalitarian†¦feminist (Gross

The gastrointestinal tract Free Essays

string(84) " the first in vitro study investigating the peristaltic reflex in guinea pig ileum\." ABSTRACT The objective of the present study was to examine the effect of 5-HT4 receptor ligands on the peristaltic reflex in the mouse colon. 5-hydroxytryptamine, a neurotransmitter found mainly within the gastrointestinal tract, has been implicated in the contraction and relaxation of smooth muscle within this region. The actions of 5-HT are mediated by at least one or more of seven subtype receptors. We will write a custom essay sample on The gastrointestinal tract or any similar topic only for you Order Now The receptor subtype that will be the focus of attention in this study is the 5-HT4 receptor. Segments of the proximal colon obtained from MF1 mice, were cannulated at the anal and aboral ends, and secured horizontally in a water jacketed bath containing oxygenated Krebs solution. The intraluminal distension pressure was controlled by adjusting the elevation of the reservoir, and the volume ejected to the aboral side was recorded and measured via a a pressure transducer and Power Lab system using Chart v4.1.2 software for Windows.. All drugs were administered serosally. Cumulative concentration response curves of 5-HT and tegaserod (agonists) were obtained by adding increasing concentrations of drugs at an interval of 5-15 minutes. The antagonists GR113808 and SB204070 were added to the tissues after regular peristalsis was obtained and allowed to equilibrate for 15 minutes, after which either 5-HT or tegaserod were added cumulatively. All results are expressed as mean ±SEM from number of animals indicated by n. A regular peristalsis was established before the addition of 5-HT (average rate of peristalsis was 77 ±7, n=7. 5-HT facilitated peristalsis at 10-7M and further cumulative addition of 5-HT caused a slow decrease in peristalsis until at 10-4M, rate of peristalsis was inhibited. In all tissues in which peristalsis was inhibited, it recovered once tissue was washed. In the presence of SB204070 and GR113808, there was no significant change in the rate of peristalsis. The addition of tegaserod produced only a slow decrease in peristalsis until peristalsis was abolished in all tissues at 10-4M. The peristalsis abolished by tegaserod could not be re-established in any tissue by washing. In all tissues, it was possible to obtain peristalsis so the effects of drug testing could be established. The addition of the 5-HT4 selective receptor antagonists, SB204070 and GR113808, showed no significant change in the concentration-response curves. The partial 5-HT4 agonist, tegaserod, also did not facilitate peristalsis in the current study. Both these findings suggest that the 5-HT4 receptor is not implicated in the mouse proximal colon INTRODUCTION 1.1 The gastrointestinal tract The digestive system is a vital component of the human body; the overall function being to provide nourishment for over a trillion cells within the body. To be able to do this, the digestive system is specialised to ingest food, propel it through the digestive tract, digest it, and absorb water, electrolytes and other nutrients from the lumen of the gastrointestinal tract (Seeley et al, 2006). The absorbed substances are transported to the cells, via the circulatory system, whilst the undigested substances are eliminated from the anus. The digestive system consists of the main digestive tract, a tube extending from the mouth to the anus, as well as its associated component organs and accessory organs, which are primarily glands located outside the digestive tract that secrete fluids into the digestive tract (Seeley et al, 2006). The component organs include the oral cavity (mouth), pharynx (throat), oesophagus, stomach, small intestine, large intestine and anus. The accessory organs include three pairs of salivary glands, the exocrine pancreas and the exocrine liver. To enable the homoeostatic environment within the body to be maintained, it is vital that the digestive system is functioning efficiently. The large intestine, which consists of the caecum, colon and rectum, has sufficient homeostatic functions, and contributes to the overall stability of the homoeostatic environment within the body. The colon is the central part of the large intestine, and constitutes the last 150cm of the gastrointestinal tract. It i s approximately a 6cm tube, which extends from the ileum to the anus. Its main function is to store faecal material and regulate its release into the external environment (Smith et al, 2006). It also produces a thick mucous secretion, which lubricates the passage of faecal material during defecation. The gastrointestinal tract of a mouse consists of the oesophagus, stomach, small intestine and large intestine. The mouse colon is similar to the human colon, consisting of the ascending, transverse and descending parts but lacking the sigmoid part (Cook, 1965). http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/G/GITract.html The main physiological processes of the digestive system are digestion, absorption, motility, secretion, and excretion. Digestion involves the breakdown of larger molecules to smaller ones (i.e. glucose and amino acids) to allow efficient utilisation and absorption of these molecules. The ingested material and secretions are transported across the epithelial cell membrane, mainly within the small intestine. Subsequently, the transported molecules enter the circulation; a central physiological process of the digestive system. The gastrointestinal tract is approximately a 15 feet long tube, and food must be moved along it to reach the correct sites for digestion, mixing and absorption (Smith et al, 2001). This process, known as peristalsis, is aided by the smooth muscle lining the tract, which contracts and relaxes mixing the ingested material, whilst at the same time propelling it through the tract. Propulsion of the intestinal contents is a crucial part of digestion that depends on the coordinated activity of circular and longitudinal smooth muscles brought about by the peristaltic reflex (Shiinaa et al, 2005). The peristaltic reflex is initiated by either stimulation of the gastrointestinal mucosa or by stretching of the intestinal wall, resulting in a circular contraction behind the stimulus and an area of relaxation in front of it (Shiinaa et al, 2005). This wave of contraction moves in the oral-anal direction, and subsequently propels the contents within the lumen forward. The reflex is co-ordinated by the intramural nerve plexuses within the intestine and so, can be obtained even in the isolated tissues. Many studies investigating the mechanisms which mediate intestinal motility have predominantly focused on peristalsis. Trendelengburg (1917) carried out the first in vitro study investigating the peristaltic reflex in guinea pig ileum. You read "The gastrointestinal tract" in category "Essay examples" Within the ileum, the reflex was found to consist of contractions of both the longitudinal and circular muscles that were both regular as well as coordinated. The increase in intraluminal pressure, which causes the ileum to distend, is followed by an increase in longitudinal muscle contraction, and subsequently, by an increase in circular muscle contraction, which propels the contents towards the anal section (Trendelengburg, 1917). Gastrointestinal disorders are a common problem in today’s society, and many lead to long term diseases and even morbidity, as well as having a negative impact on healthcare costs (Crowell et al, 2004) However, due to the complexity and the differing functions of the various organs of the GI tract, the treatment of disorders within the tract is a very complex task and has not, as of yet, been fully understood. Diseases of the colon can lead to a whole host of illnesses, including diarrhoea, constipation, Crohn’s disease, Inflammatory Bowel disease, Irritable Bowel Syndrome (IBS), and many more. Symptoms occurring outside of the GI tract, in particular symptoms associated with ibs, including anxiety, depression and schizophrenia, have been related to the morbidity of such disorders. It has been suggested by research, that altered levels of the neurotransmitter, 5-hydroxytryptamine (serotonin), may lead to both intestinal and extra intestinal symptoms in IBS, as well as being implicated in other functional bowel diseases It is therefore important that further studies are carried investigating the link between 5-hydroxytryptamine and disorders of the gastrointestinal tract, and to further understand the pathogenesis of these disorders, so that new, more effective treatments can be formulated. 1.25-hydroxytryptamine 5-hydroxytryptamine, also more commonly referred to as serotonin, is a monoamine neurotransmitter, and is predominantly synthesised, stored and released in the enterchromaffin cells of the intestinal mucosa (Costedio et al, 2007). According to Gershon et al (1965), 5-HT is synthesised through the action of two tryptophan hydroxylases, TpH1 and TpH2, which are found within the enterochromaffin cells and neurons. Approximately 95% of all mammalian 5-hydroxytryptamine is found within the gastrointestinal tract (Sanger, G.J, 2008) 5-HT initiates the peristaltic and secretory reflex, and transmits information to the central nervous system, by activating both the intrinsic and extrinsic primary afferent neurones (Sikandar et al 2009). It can also modulate a wide range of biological processes such as mood, cognition, perception, feeding behaviour, smooth muscle contractility, and platelet aggregation (Setola et al, 2003). Within the guinea pig ileum, 5-HT has been found to cause both facilitation and inhibition of peristalsis (Tuladhar et al), and has been found to facilitate peristalsis, when added serosally in the marmoset ileum (Tuladhar et al, 1996). The actions of 5-HT, particularly contraction or relaxation responses, are mediated by at least one or more of seven subtype receptors (Setola et al, 2003), ranging from 5-HT1 to 5-HT7. 5-HT1 and 5-HT2 receptors have been further subdivided, as can be seen in figure 2.With the exception of the 5-HT3 receptor, the other receptors are, at molecular level, G protein couple metabotropic receptors which span the membrane. The 5-HT3 receptor is a ligand-gated ion channel (Barnes et al, 1999). Many 5-HT receptors can now be associated with various physiological responses, ranging from modulation of neuronal activity and transmitter release to behavioural change (Barnes et al, 1999). Receptor Subtype Transduction Mechanism Localization Function Specific Agonists Specific Antagonists 5-HT1AvAC (Gi/o)Limbic system (hippocampus, lateral septum, cortical areas), mesencephalic raphe nucleiHyperpolarization, modulation of neurotransmitter release, anxiolysis, hypothermia, hyperphagiaXaliprofen (2491) S 14506 (1771) Ipsapirone (1869) BP 554 (0556) U 92016A (2739) Tandospirone (2854)*MM 77 (0933) NAN-190 (0553) Spiroxatrine (0631) (S)-WAY 100135 (1253) 5-HT1BvAC (Gi/o)Basal ganglia, striatum, amygdala, trigeminal ganglion, vascular smooth muscleAutoreceptor, locomotion, hypophagia, hypothermia, modulation of neurotransmitter release, vasoconstrictionCGS 12066B (0638) CP 93129 (1032) CP 94253 (1317) 5-Nonyloxytryptamine (0901)GR 55562 (1054) Isamoltane (0992) SB 224289 (1221) NAS-181 (1413) 5-HT1DvAC (Gi/o)Basal ganglia, hippocampus, cortex, spinal cord, vascular smooth muscleAutoreceptor, modulation of neurotransmitter releaseL-694,247 (0781) GR 46611 (0864) PNU 109291 (2556) PNU 142633 (1985)BRL 15572 (1207) Cyanopindolol (0993) LY 310762 (3078) 5-ht1EvAC (Gi/o)Cortex, caudate putamen, claustrum, hippocampus, amygdalaUnknownBRL 54443 (1129)– 5-HT1FvAC (Gi/o)Hippocampus, cortex, dorsal raphe nucleus, uterusSpeculative role in visual and cognitive functionBRL 5443 (1129) LY 344864 (2451) LY 334370 (3079)– 5-HT2A^ PLCForebrain, caudate nucleus, nucleus accumbens, hippocampus, olfactory tubercle, vascular smooth muscle, blood plateletsNeuronal depolarization, head twitch, hyperthermia, modulation of neurotransmitter release smooth muscle contraction, platelet activationTBC-2 (2592)R-96544(1742) Spiperone (0995) MDL 11,939 (0870) 4F 4PP (0523) Risperidone (2865) 5-HT2B^ PLCBrain, stomach fundus (rat), gut, heart, kidney, lungContraction of the stomach fundus, anxietyBW 723C86 (1059)SB 204741 (1372) LY 272015 (3077) 5-HT2C^ PLCChoroid plexus, cortex, limbic system, basal gangliaHypolocomotion, hypophagia, penile erection, hyperthermia, anxiety, v noradrenalin and dopamine releaseMK 212 (0941) Ro 60-0175 (1854) WAY 161503 (1801) CP 809101 (3041) 1-Methylpsilocin (3017)N-Desmethylclozapine (1007) RS 102221 (1050) SB 242084 (2901) 5-HT3Ion channel (Na+, K+, Ca2+)Dorsal vagal complex, hippocampus, amygdala, caudate, cerebral cortex, heart, intestinesAnxiety, cognition, pain , reward/withdrawal, vomiting reflex, vasodilation, intestinal tone and secretionSR 57227 (1205) Quipazine (0629) 1-phenylbiguanide (0969) m-chlorophenylbiguanide (0440)MDL 72222 (0640) Tropisetron (2459) Y-25130 (0380) Ondansetron (2891) Granisetron (2903) 5-HT4^ AC (Gs)Cerebral cortex, limbic areas, hippocampus, colliculus, intestinesLearning and memory, visual perception, anxiety, motor coordination, arousal, smooth muscle relaxation, modulation of neurotransmitter releaseCisapride (1695) RS 67333 (0989)* RS 67506 (0990)* CJ 033466 (3089)*GR 113808 (1322) GR 125487 (1658) RS 39604 (0991) RS 23597-190 (0728) 5-ht5Av AC (Gi/o)Amygdala, hippocampus, caudate nucleus, cerebellum, hypothalamus, thalamus, substantia nigra, spinal cordModulation of exploratory behavior and locomotion–SB 699551 (3188) 5-HT6^ AC (Gs)Striatum, olfactory tubercles, nucleus accumbens, hippocampus, stomach, adrenal glandsMemory and learning, modulation of neurotransmitter release5-Methyl-5-hydroxytryptamine (0558) EMD 386088 (2382)SB 258585 (1961) Ro 47-1816/001 (2911) SB 399885 (3189) NPS ALX Compound 4a (3285) 5-HT7^ AC (Gs)Thalamus, hypothalamus, hippocampus, cerebral cortex, amygdala, GI and vascular smooth muscle, heartCircadian rhythms, smooth muscle relaxation, nociception, hypotension, modulation of REM sleep, learning and memory, LH releaseAS 19 (1968) LP 44 (2534) LP 12 (2925)Pimozide (0937) SB 269970 (1612) SB 259719 (2726) Figure 2: A table summarising the properties of 5-HT receptors and subtypes (http://www.tocris.com/pharmacologicalBrowser.php?ItemId=5101) 1.3 5-HT4 receptor subtype The receptor subtype that will be the focus of attention in this study is the 5-HT4 receptor subtype. These receptors are located primarily in the nigrostriatal and mesolimbic systems and smooth muscle in the gastrointestinal tract, and play a role in gastrointestinal motility (Craig Clark, 1989), as well as in anxiety, visual perception, memory and learning. The 5-HT4 receptors on intrinsic primary and afferent neurones, are activated by endogenous serotonin released from enterchromaffin cells, in response to mechanical or chemical stimuli. These neurons release transmitters such as calcitonin gene-related peptide (CGRP), activating interneurons which in turn stimulate excitatory neurons on the orad side of the mucosal stimulus and stimulate inhibitory neurons on the caudad side (Ji et al, 2004). Subsequently, this results in peristaltic reflexes occurring at the site of the originating stimuli. The effect of 5-HT4 receptor modulated peristalsis has been found in guinea pig ileum (Tuladhar, 1994; Tuladhar et al, 1995). Also, stimulation of 5-HT4 receptors have been reported to enhance the peristaltic reflex in the rat distal colon (Kadowaki et al, 2002). 5-HT4 receptor agonists, such as tegaserod and 5-HT, stimulate gastrointestinal motility and secretion through release of acetylcholine from excitatory neurones. It is important to note that 5-HT4 agonists strengthen, rather than directly activate the peristaltic reflexes 1.45-HT4 receptor agonists and antagonists The 5-HT4 receptor agonists that will be focus of this study will be tegaserod and 5-hydroxytryptamine (as mentioned above), and antagonists will be GR113808 and SB204070. Tegaserod [3-(5-methoxy-1H-indol-3-ylmethylene)- N-pentyl-carbazimidamide] hydrogen maleate, is a partial 5-HT4 agonist that has been implicated in gastro-intestinal motility. In the guinea pig ileum, tegaserod was found to stimulate peristalsis by increasing the number of circular muscle contractions (Ji et al, 2004). It has been used in the treatment of symptoms of irritable bowel syndrome, including abdominal pain, bloating and constipation (Muller-Lissner et al, 2001). The responses mediated by 5-HT4 receptors have been greatly facilitated by a number of highly selective antagonists e.g. GR113808, SB204070 SB204070 (1-Butyl-4-piperidinyl)methyl-8-amino-7-chloro-1,4-benzodioxane-5-carboxylate hydrochloride) is a selective 5-HT4 serotonin receptor antagonist. In the guinea pig distal colon, SB204070 was found to antagonize 5-HT4 receptor mediated-contractions Although the nature of the antagonism is quite complex, it has been suggested that SB204070 acts has a pseudo-irreversible antagonist (Wardle et al, 1994). GR113808 (1-methyl-1H-indole-3-carboxylic acid, [1-[2-[(methylsulfonyl)amino]ethyl] -4-piperidinyl]methyl ester) is a potent, selective 5-HT4 receptor antagonist. In the guinea-pig ascending colon, GR113808 behaved as an antagonist of 5-hydroxytryptamine -induced contraction, with a high affinity for the 5-HT4 receptor (Gale et al, 1994). 1.3Aims of the study The aims of our investigation were to investigate whether 5-HT4 receptor ligands were able to modulate the peristaltic reflex within the mouse proximal colon. This study also allowed us to investigate the effect of pharmacological manipulations that have been designed to study the role of 5-hydroxytryptamine on the peristaltic reflex within this region of the intestine. This study was undertaken using a range of 5-HT4 receptor agonists and antagonists. METHOD 2.1 Krebs solution The Krebs-Heinslet solution was prepared at the start of the experiment. To prepare one litre of the solution, 2.1g of sodium hydrogen carbonate (NaHCO3) and 2g of glucose were dissolved in 300ml of dissolved water. 40ml of the Krebs-Heinslet concentration was added to the solution, and the preparation was made up to 1 litre using distilled water. It was found that 5 litres was an adequate volume for the experiment, therefore this was prepared by multiplying each quantity by 5. The marriotte bottle containing the Krebs-Heinslet solution was attached to the apparatus, and used to wash out each organ bath three times, and then added to the required level. 2.2 Preparation of the tissue The experiment was carried out using MF1 mice. The animals were killed by cervical dislocation, and the GI tract was removed. Segments of the proximal colon (approx. 2-3cm) were carefully dissected on a polystyrene board, taking care not to puncture the colon and to disturb it as little as possible. This section was then quickly transferred to the water jacketed glass bath, which contained Krebs-Heinslet solution aerated with 95% oxygen and 5% CO2, and maintained at 37OC. This was to prevent hypoxia of the tissue and abnormal temperature. All tissues were equilibrated for at least 20 minutes prior to the start of the experiment. The oral end of the proximal colon was cannulated to the inflow glass tube, which was connected to the reservoir containing saline solution, and secured with thread. The intraluminal contents of the colon were allowed to expel naturally via peristalsis, brought about by the raising of the height of the reservoir by 4cm. After the contents had been expelled, the reservoir was lowered and the aboral end was then cannulated to the opposing outflow glass tube. The tissue was then left to equilibrate for at least 20 minutes prior to the start of the experiment. Finally, to induce peristalsis, the intraluminal pressure was raised, by raising the reservoir by 4cm for at least 15 minutes, until peristalsis became regular and the drugs could be administered; the height of the reservoir needed to achieve steady peristalsis was determined in preliminary experiments. 2.3 Experimental preparation The outflow tube was connected, via a plastic tube, to a T glass tube, which was open to the atmosphere. Changes to the volume of fluid driven into this vertical tube during peristalsis were measured as a pressure changes, and recorded using pressure transducers connected to a quad bridge amplifier and Power Lab system using Chart v4.1.2 software for Windows. Before the proximal colon was cannulated, the computer software was calibrated to zero, and set to commence recording. Figure 3: A schematic diagram representing apparatus used to study peristalsis in mouse proximal colon. The peristalsis trace on the power lab software was recorded as a series of peaks and troughs. During peristalsis the peaks were formed when the tissue contracted, and the troughs formed when the tissue relaxed. This cycle was repeated with each peristaltic stroke. 2.4 Administration of drugs After regular peristalsis had been established, the drugs could be administered serosally. A cumulative response curve for the agonist tegaserod was obtained by adding increasing concentrations of tegaserod (0.01 µM– 10 µM). In the preliminary experiments, it was found that tegaserod 10-2M did not allow the tissue to exhibit peristalsis sufficiently, and was too potent, therefore the highest concentration used was 10-3M. Each concentration had a 15 minute contact time with the tissue before the next concentration was administered. The volume ejected and the rate of peristalsis was measured and recorded. Changes to the rate of peristalsis were then compared to the control values obtained 15 minutes prior to administering the first drug. In the preliminary experiments, it was found that washing the tissue between each drug administration had a negative effect on peristalsis, and subsequently the tissue didn’t recover. Therefore drugs were administered continuously wit hout washout. This process was repeated with the agonist, 5-HT, with concentrations ranging from 0.1 µM-100 µM. To examine the effects of GR113808 and SB204070 (antagonists) on 5-HT and tegaserod responses, either antagonist was added to the tissues after regular peristalsis was obtained and allowed to equilibrate for 15 minutes, after which either 5-HT or tegaserod were added cumulatively and their effects on peristalsis were measured as described above 2.5 Statistical analysis All results are expressed as mean ±SEM from number of animals indicated by n. The difference between the values was determined by using the unpaired t test when two groups were compared and using the one way ANOVA followed by Fisher’s PLSD when more than two groups were compared. 2.6Consideration of safety issues The chemicals used within this investigation were obtained from Tocris bioscience. To ensure the safety of all members of the group throughout the duration of the investigation, a chemical risk assessment form (COSHH) was formulated and signed by all members. This form highlighted all the chemicals that were to be used throughout the experiment, and the risks and precautions associated with each of them. It was ensured that the precautions were adhered to at all stages of the experiment, and general laboratory regulations were also put into place i.e. no eating or drinking in labs, wearing a lab coat etc. RESULTS The peristaltic reflex was investigated within the mouse proximal colon. Segments of the proximal colon (approximately 3cm in length) were cannulated in vitro, and regular peristalsis was achieved by raising of the intraluminal pressure. Peristalsis was distinguished as circular muscle contractions arising from the oral side and travelling to the anal side. The proximal part of the colon was distinguished from the distal part by striations across the surface, and also by it containing softer faecal pellets 3.1 The effects of 5-HT on the peristaltic reflex in the mouse proximal colon A regular peristalsis was established before the addition of 5-HT (average rate of peristalsis was 77 ±7, n=7). The fluid was ejected from the oral to anal direction. The addition of 5-HT 10-7M caused a significant increase in the rate of peristalsis. At this concentration the rate of peristalsis was 101  ± 8, n=7, which was a substantial increase from the control value. Further cumulative addition of 5-HT caused a slow decrease in peristalsis until at 10-4M, rate of peristalsis, at 56  ± 19, n=7 , was lower than the control at the beginning. In all tissues in which peristalsis was inhibited, it recovered once tissue was washed. 3.2 The effects of the 5-HT4 receptor antagonist, SB204070, on the cumulative addition of 5-HT on the peristaltic reflex in the mouse proximal colon 3.3 The effects of tegaserod on the peristaltic reflex in the mouse proximal colon 3.4The effects of the 5-HT4 receptor antagonist, GR113808, on the cumulative addition Tegaserod on the peristaltic reflex in the mouse proximal colon DISCUSSION Gastrointestinal disorders within humans and animals have become much more common, and as such more effective treatments need to be formulated. Research has implicated 5-hydroxytryptamine within these disorders, and thus the 5-HT receptors, which are involved in gastrointestinal motility, are potential targets for treating such disorders. The present investigation was designed to study the peristaltic reflex within the mouse proximal colon, and further, to investigate the 5-HT4 receptor, which has been found to modulate peristalsis in the guinea pig ileum (Tuladhar et al., 1995). Peristalsis is the principle mechanism controlling the movement of chyme within the intestine, and takes place without the conscious control. The nervous pathway of the peristaltic reflex is entirely intrinsic (Bulbring et al,1958), and therefore we can obtain this reflex even in isolated tissues. The method used to study peristalsis was similar to the one used by Trendelengburg (1917), in which the peristaltic reflex was triggered by raising of the intraluminal pressure, allowing the measurement of different parameters of peristalsis, including the rate of peristaltic stokes and the volume of intraluminal fluid ejected to the anal side with each peristaltic stroke. Within the present study, regular peristalsis was obtained so the effects of the 5-HT4 receptor ligands could be established. Craig and Clarke (1991) suggested that the 5-HT4 receptors had a facilitatory effect on 5-HT in the guinea-pig ileum and this was further confirmed by Tuladhar et al (1993). However, this finding was not reciprocated within the mouse proximal colon. Cumulative addition of 5-HT produced facilitation of peristalsis within the mouse proximal colon, characterised by an increase in the number of peristaltic strokes per hour and thus the rate of peristalsis at 10-7M.. This facilitation was observed at concentrations up until10 -4M, where inhibition of peristalsis was observed. At this concentration, 5-HT desensitised the tissues so no further peristalsis could be established. However, peristalsis was re-established in 6 out of the 7 tissues after washing of the tissues. This facilitatory and inhibitory effect of 5-HT was also observed in various studies carried out by Tuladhar et al, Bulbring Crema (1958) and others. Therefore, this study has shown that the addition of 5-HT in vitro can modulate peristalsis within the mouse proximal colon. At lower concentrations, 5-HT facilitates peristalsis, whereas at higher concentrations 5-HT can both facilitate and inhibit peristalsis. In the present study both GR113808 and SB204070 failed to affect the facilitatory effect of 5-HT in the mouse proximal colon. GR113808 and SB204070 are both highly potent 5-HT4 receptor antagonists (Gale et al., 1994; Wardle et al., 1994). This suggests that the 5-HT4 receptor is not implicated within the mouse proximal; had it been implicated both SB204070 and GR113808 would have antagonised the 5-HT4 receptor mediated contractions, and there would have been a significant decrease in the rate of peristalsis. This is in contrast to the findings by Costall et al (1993), where the 5-HT4 receptor was implicated in the guinea pig ileum, in which it exhibited a facilitatory effect on 5-HT. In the guinea-pig ileum tegaserod has also been shown to facilitate peristalsis ( Ji et al, 2004 ), which was not observed in the current study. This further suggests that the 5-HT4 receptor is not implicated within the mouse proximal colon; as tegaserod is a partial 5-HT4 agonist, had 5-HT4 receptor been implicated, facilitation of peristalsis would have been observed. The inhibitory effect of 5-HT on peristalsis has been reported to involve the 5-HT7 receptor (Tuladhar et al, 2003). Further studies are required to examine the receptor involved in the inhibitory effect of 5-HT in the mouse colon and to examine whether 5-HT7 receptors are involved. It is interesting to note that the inhibitory effect of tegaserod could involve a completely different mechanism as peristalsis could not be recovered by washing in any tissue, in contrast with 5-HT. In conclusion, the current study has shown that 5-HT can both facilitate and inhibit peristalsis. However, the 5-HT receptors mediating these effects are likely to be different from the ones involved in the modulation of peristalsis in the guinea-pig ileum. Further studies are required to establish the receptors involved. REFERENCES ARBAB SIKANDERA, S. V. R., A, AND KAUSHAL KISHOR PRASADA (2009). Role of serotonin in gastrointestinal motility and irritable bowel syndrome. Clinica Chimica Acta, 403, 47-55 BARNES, N. M. SHARP, T. (1999). A review of central 5-HT receptors and their function. Neuropharmacology, 38, 1083-1152. BULBRING, E., LIN RC (1958)The effect of intraluminal application of 5-hydroxytryptamine and 5-hydroxytryptophan on peristalsis; the local production of 5-HT and its release in relation to intraluminal pressure and propulsive activity. J Physiol 2006 Aug 15;575(Pt 1):1-2. COOK, M. J. (1965) The anatomy of the laboratory mouse. London (New York): Academic Press. COSTEDIO, M., HYMAN, N. MAWE, G. (2007). Serotonin and Its Role in Colonic Function and in Gastrointestinal Disorders. Diseases of the Colon Rectum, 50, 376-388. CRAIG, D. A. CLARKE, D. E. 1990. Pharmacological characterization of a neuronal receptor for 5-hydroxytryptamine in guinea pig ileum with properties similar to the 5-hydroxytryptamine receptor. Journal of Pharmacology and Experimental Therapeutics, 252, 1378-1386. CROWELL, M. D. 2004. Role of serotonin in the pathophysiology of the irritable bowel syndrome. British journal of pharmacology, 141, 1285-93. GALE, J. D., GROSSMAN, C. J., WHITEHEAD, J. W., OXFORD, A. W., BUNCE, K. T. HUMPHREY, P. P. (1994). GR113808: a novel, selective antagonist with high affinity at the 5-HT4 receptor. British journal of pharmacology, 111, 332-8. GERSHON, M. D., DRAKONTIDES, A. B. ROSS, L. L. 1965. Serotonin: Synthesis and Release from the Myenteric Plexus of the Mouse Intestine. Science, 149, 197-9. JI, S. W., PARK, H., CHUNG, J. P., LEE, S. I. LEE, Y. H. 2004. Effects of tegaserod on ileal peristalsis of guinea pig in vitro. Journal of pharmacological sciences, 94, 144-52. Kadowaki, M., Wang, X.B., Shimatani, H., Yoneda, S. Takaki, M. (2002). 5-HT4 receptor enhances the propulsive power of the peristaltic reflex in the rat distal colon. Naunyn-Schmied. Arch. Pharmacol, 99, 62-65. MARGARET E. SMITH, D. G. M. (2001). The digestive system- Basic science and clinical conditions, Elsevier ltd. MULLER-LISSNER, S. A. (2001) Tegaserod, a 5-HT(4) receptor partial agonist, relieves symptoms in irritable bowel syndrome patients with abdominal pain, bloating and constipation Aliment Pharmacol Ther ROD R. SEELEY, T. D. S., PHILIPSTATE(2006). Anatomy and physiology. McGraw Hill Higher Education SANGER, G. J. (2008). 5-hydroxytryptamine and the gastrointestinal tract: where nextTrends in pharmacological sciences, 29, 465-71. SETOLA, V. ROTH, B. L. (2003). Why Mice Are Neither Miniature Humans nor Small Rats: A Cautionary Tale Involving 5-Hydroxytryptamine-6 Serotonin Receptor Species Variants. Molecular Pharmacology, 64, 1277-1278. SHIINA, T., SHIMIZU, Y., SUZUKI, Y., NIKAMI, H. TAKEWAKI, T. (2005). Measurement of the propelled liquid by isolated hamster ileum as a parameter to evaluate peristalsis. European Journal of Pharmacology, 517, 120-126. SIKANDER, A., RANA, S. V. PRASAD, K. K. (2009). Role of serotonin in gastrointestinal motility and irritable bowel syndrome. Clinica chimica acta; international journal of clinical chemistry, 403, 47-55. TULADHAR, B.R., COSTALL, B. NAYLOR, R.J. (1995). Evidence of a 5-Ht3 Receptor-Mediated Facilitation of the Emptying Phase of the Peristaltic Reflex in the Isolated Guinea-Pig Ileum. Br J Pharmacol, 114, P374-P374. TULADHAR, B.R., COSTALL, B. NAYLOR, R.J. (2002). Modulation of 5-HT4 receptor function in the rat isolated ileum by fluoxetine: the involvement of endogenous 5-hydroxytryptamine. Br J Pharmacol, 136, 150-6. TULADHAR B.R (2003) 5-HT7 receptors mediate the inhibitory effect of 5-HT on peristalsis in the isolated guinea-pig ileum. Br J Pharmacol WARDLE, K. A., ELLIS, E. S., BAXTER, G. S., KENNETT, G. A., GASTER, L. M. SANGER, G. J. (1994). The effects of SB 204070, a highly potent and selective 5-HT4 receptor antagonist, on guinea-pig distal colon. British journal of pharmacology, 112, 789-94. HTTP://WWW.TOCRIS.COM/PHARMACOLOGICALBROWSER.PHP?ITEMID=5115. APPENDIX Table 1: 5-HT alone S.No -log C (M) RATE OF PERISTALSIS 1 2 3 4 5 6 7 AVG SEM N 1 Before58.7 56.9 71.6 114.9 73.9 77.1 82.2 77 7 7 2 7.00 126.8 77.6 95.1 115.3 119.4 76.8 95.6 101 8 7 3 6.00 120.4 58.1 77.3 102.7 127.7 92.1 70.2 93 10 7 4 5.00 42.9 26.1 61.9 104.5 93.0 67.9 93.7 70 11 7 5 4.00 0.0 0.0 37.9 105.7 113.7 29.8 105.0 56 19 7 Table 1 shows the rate of peristalsis after adding the agonist,5-HT 10-8 – 10-4 M, to mouse proximal colon. The values are expressed as mean ±SEM. Table 2: 5-HT in the presence of SB204070 S.No -log C (M) RATE OF PERISTALSIS 1 2 3 4 5 6 7 AVG SEM N 1 SB-204070 7.00 79.4 129.3 44.1 31.2 101.6 79.2 82.8 78.2 12.4 7 2 5-HT 5.00 149.9 124.6 71.3 30.2 102.7 58.8 95.1 90.4 15.3 7 3 5HT 4.00 113.8 132.2 19.7 27.9 96.3 51.2 130.3 81.6 18.1 7 4 5HT 3.00 90.8 114.9 23.0 25.9 99.2 77.2 0.0 61.6 16.8 7 5 5HT 2.00 0.0 122.1 0.0 0.0 0.0 55.8 0.0 25.4 17.9 7 Table 2 shows the rate of peristalsis after adding 5-HT 10-5 – 10-2 in the presence of the 5-HT4 antagonist, SB204070 10-7M, to the mouse proximal colon. The values are expressed as mean ±SEM. Table 3: Tegaserod alone S.No -logC (M) RATE OF PERISTALSIS 1 2 3 4 5 AVG SEM N 1 Before 42.6 45.6 151.3 45.6 116.6 80.322.5 5 2 8.00 40.9 40.9 127.3 41.3 123.0 74.7 20.6 5 3 7.00 38.7 35.2 107.4 32.6 0.0 42.8 17.5 5 4 6.00 31.1 38.1 97.9 27.9 123.3 63.7 19.6 5 5 5.00 0.0 0.00 0.00 0.0 45.4 9.0 9.0 5 Table 3 shows the rate of peristalsis after adding the agonist, tegaserod 10-8 – 10-5 M, to mouse proximal colon. The values are expressed as mean ±SEM. Table 4: Tegaserod in the presence of SB204070 S.No -logC (M) RATE OF PERISTALSIS 1 2 3 4 5 AVG SEM N 1 BEFORE 99.4 107.5 121.2 124.3 105.4 111.5 4.7 5 2 SB-204070 7.00 64.5 98.1 65.1 59.8 53.6 68.2 7.7 5 3 Tegaserod 8.00 100.1 105.8 91.3 110.8 54.3 92.5 10.0 5 4 Tegaserod 7.00 107.3 122.2 74.5 72.5 59.7 87.3 11.7 5 5 Tegaserod 6.00 111.4 113.4 99.2 90.5 83.799.6 5.7 5 6 Tegaserod 5.00 0.00.0 104.9 213.4 75.7 78.8 39.5 5 Table 4 shows the rate of peristalsis after adding tegaserod 10-8 – 10-5 in the presence of the 5-HT4 antagonist, SB204070 10-7M, to the mouse proximal colon. The values are expressed as mean ±SEM. Table 5: Tegaserod in the presence of GR113808 S.No -logC (M) RATE OF PERISTALSIS 1 2 3 4 5 6 7 AVG SEM N 1 BEFORE 33.0 108.2 129.9 50.7 31.9 34.1 35.0 64.8 17.6 7 2 GR113808 6.00 15.6 82.6 121.6 47.6 25.2 18.4 19.6 52.0 17.2 7 3 Tegaserod 8.00 37.8 267.2 105.9 48.0 22.2 26.12 21.5 75.5 33.8 7 4 Tegaserod 7.00 71.3 339.7 112.2 49.7 17.4 24.00 9.2 89.0 43.9 7 5 Tegaserod 6.00 74.4 277.4 49.0 37.2 19.9 14.53 0.0 67.4 36.2 7 6 Tegaserod 5.00 20.1 0.0 0.0 30.7 -1.5 10.02 0.0 8.4 4.7 7 Table 5 shows the rate of peristalsis after adding tegaserod 10-8 – 10-5 in the presence of the 5-HT4 antagonist, GR11380810-6M, to the mouse proximal colon. The values are expressed as mean ±SEM. How to cite The gastrointestinal tract, Essay examples

The Octopus Essay Example

The Octopus Essay Boleslav Akselrud Professor Schrepfer Facets of The Octopus In Frank Norris’ first installment of his intended three part series on wheat, and the crop’s far reaching global implications, The Octopus: A Story of California, the author adapts the events and circumstances surrounding the 1880 Mussel Slough tragedy to paint the picture of the historically rugged and prospecting American west’s collision with large industrial capital and monopolized industry; specifically the railways of the Southern Pacific Rail Company. Norris adopts, and in some ways pioneers the naturalist style of writing at the turn of the twentieth-century, but The Octopus is not merely a work of fiction; the novel provides a realist perspective to a complex period of the American frontier’s history. While depicting this unique period of the American frontier, Norris is however, guilty of tailoring certain characters to fit his purposes, and taking advantage of his control of the reader’s emotions, specifically interpretations of good and evil, to align readers with his views of the betrayal of the farming industry by the unstoppable force of the rail industry. We will write a custom essay sample on The Octopus specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on The Octopus specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on The Octopus specifically for you FOR ONLY $16.38 $13.9/page Hire Writer The book opens with an introduction to a set of grain farms in the San Joaquin Valley of California. Readers are introduced to Presley, a young man well-educated at an eastern college who chose to live on one of the local ranches, Los Muertos, due, in part, to the cleanliness of the air after nearly dying of tuberculosis. Presley is a writer, but at the beginning of the novel, he states that his artistic inspiration has all but failed him, also playing a hand in his relocation to the Valley. He was in search of a subject; [†¦] he did not know exactly what; some vast, tremendous theme, heroic, terrible†¦Ã¢â‚¬  (Norris, 33) Presley will grow to be the most prevalent character in the book, and he would eventually find his inspiration, and make himself, and through him Norris’ viewpoint heard. As Norris introduces Presley and other characters, he also lays the historic foundation for the plot of the novel. Norris writes of the landscape of the farms, adding historical b ackground all the while. He describes Presley’s daytime bicycle ride through the farmland of the Valley, and through Presley’s eyes, he tells the reality of farming in California. The land in the San Joaquin was settled due in large part to the laying of rails in the area. The government worked a deal with the rail company that would allow the railway to own half of the plots within a twenty mile radius of the tracks, in return for laying them. This land, however, was not very well suited for much, especially farming due to the lack of irrigation. Because of this, the rail company offered much of their undeveloped land to settlers, with the promise of allowing them to purchase this land at rates as low as $2. 50 per acre later. The allure of the west, and the spirit of the frontier yielded interest from many, but profits for this group were contingent not only on the success of the crop, which at the time of the novel was doing poorly from lack of irrigation, but also on the logistics involved in transporting it, and by extension, the railways. As Presley rode along on his bicycle delivering mail on his way to the old town of Guadalajara, he mused on the manifestations of the issue of climate: â€Å"After the harvest, small though that harvest had been, the ranches seemed asleep. [†¦] There was no rain, there was no wind, there was no growth, no life; the very stubble had no force even to rot. [†¦] [On] the [†¦] only [division of the ranch] whereon the wheat had been successful, [this was] no doubt because of the Little Mission Creek that ran through it. (Norris, 44-47) Clearly, the ranchers would have to improve the land in order to reap any benefit from it, but in a leaflet distributed by the rail company advertising the land, the Southern and Pacific Rail Company stipulated that land prices would not be increased due to improvements performed by the farmers, such as irrigation. The issue of the railroad is at the heart of Norris’ novel. The author presents his work in such a way that clearly define s good and evil, leaving no place for ambiguity. Although he starts slowly, there can be no mistaking that his ultimate motive is painting the railways red. The first clear indication of this is evident in Presley’s interaction with one of his close friends, an engineer for the Southern and Pacific Rail Company, Dyke. Dyke is initially portrayed as a salt of the earth employee, working without complaint for the company in order to dote on his daughter, Sidney. Dyke continues to explain to Presley that he has had his pay cut dramatically, and when arguing against this, the company simply fired him. Here, Norris uses this situation to express just how much of a monopoly Southern and Pacific had, and by extension, Norris sprouts the roots for the reader’s hatred of the rail company. Presley advises Dyke to attempt to find another rail company to work for, but when Dyke presses him to suggest another, he is silenced. â€Å"Dyke’s challenge was unanswerable. † (Norris , 56) Through this, Norris is able to express just how important the ‘benevolence’ of the rail company was. Quite simply, the farms had been built around the rail, and thus almost every person’s finances depended on its policies and even its whims. Naturally, when a profitable industry smote the hopes of its dependents, a sense of anger is developed by the reader. In this sense, Norris takes advantage of the reader, and while not directly misinforming his audience, he plays on emotions to portray history in such a way that is privy to his agenda of depicting good and evil. Although it is difficult to condone the actions of the rail companies, throughout the novel Norris places such perspective as would justify others evil in light of the rail company’s greed. After Dyke was fired by the company, he decides to pursue an agricultural approach to making a living. He invests his saved earnings in a plot of land upon which he can farm hops, but even before his first harvest is ready, he learns that the railway has more than doubled its former rates for transporting the crop. Realizing that this eliminates his profit margin, he does not even bother harvesting his crop, and before long he finds himself a drunk, spending weeks on end in Caraher’s saloon. He then decides to use his knowledge of the trains to become a robber and sometimes a murderer. Norris, however, through Presley finds ways to justify this evil, and even further justifies attempts on the life of S. Behrman, the designated local villain. Regardless of the author’s intent, robbery and murder are facets of evil, but Norris places this above the actions of the rail company, using Dyke as a folk hero. In such pursuits, Norris jeopardizes The Octopus as a veritable historical source. History is not supposed to be subjective, and while this is often difficult to realize, such instances as described above display Norris’ use of the reader’s emotions to align an audience to his cause, and ultimately hinder the effectiveness of the novel as a historical document. Norris’ proliferation of this double-standard is evident not only in the heart wrenching betrayal of Dyke by the rail company, but also in the character of Magnus Derrick. Derrick owns the Los Muertos ranch, and is depicted by Norris as the proud champion of his laborers, called ‘the Governor’ by his respecting workers. This is the initial impression of the character, and it stays so, even when the uglier side of Magnus is shown. Magnus is described as an old school prospector, having made his money through the sale of his portion of the Corpus Christi gold mine in the middle of the nineteenth-century. With the crop not doing so well, and the threat of seizure of his ranch by the rail company, Derrick is faced with a moral dilemma. He must either enter the corruption of the day and submit to bribery, or lose all of his land and livelihood. When he is faced with certain defeat in the struggle with climbing freight rates, Magnus folds and aligns himself with the view that corruption is a necessary evil. The effects of this decision are far reaching, and Magnus finds himself blackmailed by the proprietor of the local newspaper who, on the rail company’s payroll, had become privy to the corruption. After the novel’s version of the armed conflict at Mussel Slough, Magnus finds himself with a dead son, no land, and a conscience that drives him to insanity. Despite the clear lack of judgment by Magnus and the obvious evil that partaking in corruption implies, his poor decisions are excused by Norris as instincts to gamble everything that he retained from his prospecting days, in hopes of making the best for himself and his dependents. Norris further blames the rail industry for forcing Magnus into a situation where he could not come out the better, and thus can pin the blame for Derrick’s demise on the railway, regardless of how evident it is that Magnus had a hand in his own undoing. In Norris’ eyes, there is no room for ambiguity, and he minces no words in the process of representing the Southern and Pacific Company as an evil machine. The namesake of the novel carries with it a dark connotation, and there is little doubt that this is strategically placed by the author. The rail industry is continually cast against the masses of workers, a manifestation of Norris’ ever clearer populist agenda. When showing more of Presley’s musings, he furthers the above views. â€Å"[Presley] told himself that, as a part of the people, he loved the people and sympathized with their hopes and fears, and joys and griefs. †¦] He had set himself the task of giving true, absolutely true, poetical expression to the life of the ranch, and yet, again and again, he brought up against the railroad, that stubborn iron barrier against which his romance shattered itself to froth and disintegrated, flying spume. His heart went out to the people. † (Norris, 41 ) Norris continually describes the rail industry as a machine, devoid of humanity and inherently evil. At the end of the first chapter, this view is compounded, once again through Presley’s character. Presley saw again, in his imagination, the galloping monster, the terror of steel and steam, with its single eye, cyclopean, red, shooting from horizon to horizon; but saw it now as the symbol of a vast power, huge, terrible, flinging the echo of its thunder over all the reaches of the valley, leaving blood and destruction in its path; the leviathan, with tentacles of steel clutching into the soil, the soulless Force, the iron hearted Power, the monster, the Colossus, the Octopus. † (Norris, 128) Although Norris describes an important period in the history of the American West, he is also an author, and The Octopus is a work of fiction. There are vast quantities of historical background in Norris’ story, and even some parallels to real people and events, but the author can use his words to sway the thoughts of his readers, and at times Norris can demonize the rail industry while also justifying the actions of his protagonists. Thus, while historical novels may offer unique insight to events such as the Mussel Slough Massacre, the emotional control that the authors have can sometimes skew perspectives. Works Cited Norris, Frank. The Octopus: A Story of California. Gutenberg Project, 1995. PDF.