1. Portincasa P, Moschetta A, Palasciano G. Cholesterol gallstone disease. Lancet. 2006;368:230–239.[PubMed]
2. Katsika D, Grjibovski A, Einarsson C, Lammert F, Lichtenstein P, Marschall HU. Genetic and environmental influences on symptomatic gallstone disease: a Swedish study of 43,141 twin pairs. Hepatology. 2005;41:1138–1143.[PubMed]
3. Kratzer W, Mason RA, Kächele V. Prevalence of gallstones in sonographic surveys worldwide. J Clin Ultrasound. 1999;27:1–7.[PubMed]
4. Grundy SM, Barnett JP. Metabolic and health complications of obesity. Dis Mon. 1990;36:641–731.[PubMed]
5. Grundy SM. Metabolic syndrome scientific statement by the American Heart Association and the National Heart, Lung, and Blood Institute. Arterioscler Thromb Vasc Biol. 2005;25:2243–2244.[PubMed]
6. Grundy SM, Cleeman JI, Daniels SR, Donato KA, Eckel RH, Franklin BA, Gordon DJ, Krauss RM, Savage PJ, Smith SC, et al. Diagnosis and management of the metabolic syndrome: an American Heart Association/National Heart, Lung, and Blood Institute Scientific Statement. Circulation. 2005;112:2735–2752.[PubMed]
7. Eckel RH, Grundy SM, Zimmet PZ. The metabolic syndrome. Lancet. 2005;365:1415–1428.[PubMed]
8. Tsai CJ, Leitzmann MF, Willett WC, Giovannucci EL. Prospective study of abdominal adiposity and gallstone disease in US men. Am J Clin Nutr. 2004;80:38–44.[PubMed]
9. Wang DQ, Afdhal NH. Genetic analysis of cholesterol gallstone formation: searching for Lith (gallstone) genes. Curr Gastroenterol Rep. 2004;6:140–150.[PubMed]
10. Everhart JE, Khare M, Hill M, Maurer KR. Prevalence and ethnic differences in gallbladder disease in the United States. Gastroenterology. 1999;117:632–639.[PubMed]
11. Sandler RS, Everhart JE, Donowitz M, Adams E, Cronin K, Goodman C, Gemmen E, Shah S, Avdic A, Rubin R. The burden of selected digestive diseases in the United States. Gastroenterology. 2002;122:1500–1511.[PubMed]
12. Diehl AK. Epidemiology and natural history of gallstone disease. Gastroenterol Clin North Am. 1991;20:1–19.[PubMed]
13. Attili AF, Carulli N, Roda E, Barbara B, Capocaccia L, Menotti A, Okoliksanyi L, Ricci G, Capocaccia R, Festi D. Epidemiology of gallstone disease in Italy: prevalence data of the Multicenter Italian Study on Cholelithiasis (M.I.COL.) Am J Epidemiol. 1995;141:158–165.[PubMed]
14. Attili AF, Capocaccia R, Carulli N, Festi D, Roda E, Barbara L, Capocaccia L, Menotti A, Okolicsanyi L, Ricci G, et al. Factors associated with gallstone disease in the MICOL experience. Multicenter Italian Study on Epidemiology of Cholelithiasis. Hepatology. 1997;26:809–818.[PubMed]
15. Portincasa P, Di Ciaula A, Wang HH, Moschetta A, Wang DQ. Medicinal treatments of cholesterol gallstones: old, current and new perspectives. Curr Med Chem. 2009;16:1531–1542.[PubMed]
16. Theophrastus Bombastus von Hohenheim Das Buch von den tartarischen Krankheiten nach dem alten Namen vom Stein/sand und Grieβ. In: Brisgoius IH, editor. Ander Theil der Bucher und Schrifften des Philippi Theophrasti Bombast von Hohenheim/Paracelsi. Basel: Conrad Waldkirk, 1589: 246-250
17. Portincasa P. Gallbladder and bile in health and gallstone disease: The role of motility, gallstones and bile lipid composition. Utrecht: PhD Thesis Utrecht University; 1995.
18. Wang HH, Portincasa P, Wang DQ. Molecular pathophysiology and physical chemistry of cholesterol gallstones. Front Biosci. 2008;13:401–423.[PubMed]
19. Portincasa P, Di Ciaula A, Wang HH, Palasciano G, van Erpecum KJ, Moschetta A, Wang DQ. Coordinate regulation of gallbladder motor function in the gut-liver axis. Hepatology. 2008;47:2112–2126.[PubMed]
20. Wittenburg H, Lammert F. Genetic predisposition to gallbladder stones. Semin Liver Dis. 2007;27:109–121.[PubMed]
21. Wang DQ, Zhang L, Wang HH. High cholesterol absorption efficiency and rapid biliary secretion of chylomicron remnant cholesterol enhance cholelithogenesis in gallstone-susceptible mice. Biochim Biophys Acta. 2005;1733:90–99.[PubMed]
22. Lammert F, Sauerbruch T. Mechanisms of disease: the genetic epidemiology of gallbladder stones. Nat Clin Pract Gastroenterol Hepatol. 2005;2:423–433.[PubMed]
23. Portincasa P, Moschetta A, Puglisi F, Wang DQH. Medical treatment of gallstone disease. In: Borzellino G, Cordiano C, editors. Biliary lithiasis. Basic Science, Current Diagnosis and Management. Milano: Springer Italia S.r.l; 2008. pp. 149–157.
24. Lammert F, Miquel JF. Gallstone disease: from genes to evidence-based therapy. J Hepatol. 2008;48 Suppl 1:S124–S135.[PubMed]
25. Sherlock S, Dooley J. Diseases of the liver and biliary system. Oxford: Blackwell Science; 2002.
26. Portincasa P, Moschetta A, Petruzzelli M, Palasciano G, Di Ciaula A, Pezzolla A. Gallstone disease: Symptoms and diagnosis of gallbladder stones. Best Pract Res Clin Gastroenterol. 2006;20:1017–1029.[PubMed]
27. Ammon HV, Hofmann AF. The Langenbuch paper. I. An historical perspective and comments of the translators. Gastroenterology. 1983;85:1426–1433.[PubMed]
28. Langenbuch C. Ein fall von exstirpation der gallenblase wegen chronischer cholelithiasis. Heilung. Berlin Klin Wochenschr. 1882;19:725–727.
29. Schiff M Il coleinato di soda nella cura dei calcoli biliari. L'Imparziale 1873; 13: 97-98
30. Dabney WM The use of choleate of soda to prevent the formation of gall-stones. Am J Med Sci 1876; 142: 410-412
31. Rewbridge AG. The disappearance of gallstone shadows following the prolonged admnistration of bile acids. Surgery. 1937;1:395–400.
32. Danzinger RG, Hofmann AF, Schoenfield LJ, Thistle JL. Dissolution of cholesterol gallstones by chenodeoxycholic acid. N Engl J Med. 1972;286:1–8.[PubMed]
33. Hou R, Goldberg AC. Lowering low-density lipoprotein cholesterol: statins, ezetimibe, bile acid sequestrants, and combinations: comparative efficacy and safety. Endocrinol Metab Clin North Am. 2009;38:79–97.[PubMed]
34. Istvan ES, Deisenhofer J. Structural mechanism for statin inhibition of HMG-CoA reductase. Science. 2001;292:1160–1164.[PubMed]
35. Zhu Y, Li F, Guo GL. Tissue-specific function of farnesoid X receptor in liver and intestine. Pharmacol Res. 2011;63:259–265.[PMC free article][PubMed]
36. Wang HH, Portincasa P, Mendez-Sanchez N, Uribe M, Wang DQ. Effect of ezetimibe on the prevention and dissolution of cholesterol gallstones. Gastroenterology. 2008;134:2101–2110.[PMC free article][PubMed]
37. Tait N, Little JM. The treatment of gall stones. BMJ. 1995;311:99–105.[PMC free article][PubMed]
38. Hofmann AF, Amelsberg A, vanSonnenberg E. Pathogenesis and treatment of gallstones. N Engl J Med. 1993;328:1854–1855.[PubMed]
39. Johnston DE, Kaplan MM. Pathogenesis and treatment of gallstones. N Engl J Med. 1993;328:412–421.[PubMed]
40. Gibney EJ. Asymptomatic gallstones. Br J Surg. 1990;77:368–372.[PubMed]
41. Jørgensen T. Abdominal symptoms and gallstone disease: an epidemiological investigation. Hepatology. 1989;9:856–860.[PubMed]
42. Festi D, Sottili S, Colecchia A, Attili A, Mazzella G, Roda E, Romano F. Clinical manifestations of gallstone disease: evidence from the multicenter Italian study on cholelithiasis (MICOL) Hepatology. 1999;30:839–846.[PubMed]
43. Thistle JL, Cleary PA, Lachin JM, Tyor MP, Hersh T. The natural history of cholelithiasis: the National Cooperative Gallstone Study. Ann Intern Med. 1984;101:171–175.[PubMed]
44. Friedman GD, Raviola CA, Fireman B. Prognosis of gallstones with mild or no symptoms: 25 years of follow-up in a health maintenance organization. J Clin Epidemiol. 1989;42:127–136.[PubMed]
45. Gracie WA, Ransohoff DF. The natural history of silent gallstones: the innocent gallstone is not a myth. N Engl J Med. 1982;307:798–800.[PubMed]
46. Friedman GD. Natural history of asymptomatic and symptomatic gallstones. Am J Surg. 1993;165:399–404.[PubMed]
47. Venneman NG, Renooij W, Rehfeld JF, VanBerge-Henegouwen GP, Go PM, Broeders IA, van Erpecum KJ. Small gallstones, preserved gallbladder motility, and fast crystallization are associated with pancreatitis. Hepatology. 2005;41:738–746.[PubMed]
48. Venneman NG, Buskens E, Besselink MG, Stads S, Go PM, Bosscha K, van Berge-Henegouwen GP, van Erpecum KJ. Small gallstones are associated with increased risk of acute pancreatitis: potential benefits of prophylactic cholecystectomy. Am J Gastroenterol. 2005;100:2540–2550.[PubMed]
49. Paumgartner G, Carr-Locke DL, Dubois F, Roda E, Thistle JL. Strategies in the treatment of gallstone disease. Working team report. Gastroenterol Int. 1993;6:65–75.
50. Brugge WR. The silent gallstone. In: Afdhal NH, editor. Gallbladder and biliary tract diseases. New York, NY: Marcel Dekker Inc; 2000. pp. 447–453.
51. Keus F, de Jong JA, Gooszen HG, van Laarhoven CJ. Small-incision versus open cholecystectomy for patients with symptomatic cholecystolithiasis. Cochrane Database Syst Rev. 2006:CD004788.[PubMed]
52. Keus F, de Jong JA, Gooszen HG, van Laarhoven CJ. Laparoscopic versus open cholecystectomy for patients with symptomatic cholecystolithiasis. Cochrane Database Syst Rev. 2006:CD006231.[PubMed]
53. Keus F, de Jong JA, Gooszen HG, van Laarhoven CJ. Laparoscopic versus small-incision cholecystectomy for patients with symptomatic cholecystolithiasis. Cochrane Database Syst Rev. 2006:CD006229.[PubMed]
54. Lammert F, Neubrand MW, Bittner R, Feussner H, Greiner L, Hagenmüller F, Kiehne KH, Ludwig K, Neuhaus H, Paumgartner G, et al. [S3-guidelines for diagnosis and treatment of gallstones. German Society for Digestive and Metabolic Diseases and German Society for Surgery of the Alimentary Tract] Z Gastroenterol. 2007;45:971–1001.[PubMed]
55. Giger UF, Michel JM, Opitz I, Th Inderbitzin D, Kocher T, Krähenbühl L. Risk factors for perioperative complications in patients undergoing laparoscopic cholecystectomy: analysis of 22,953 consecutive cases from the Swiss Association of Laparoscopic and Thoracoscopic Surgery database. J Am Coll Surg. 2006;203:723–728.[PubMed]
56. Tuveri M, Tuveri A. Laparoscopic cholecystectomy: complications and conversions with the 3-trocar technique: a 10-year review. Surg Laparosc Endosc Percutan Tech. 2007;17:380–384.[PubMed]
57. Duca S, Bãlã O, Al-Hajjar N, Lancu C, Puia IC, Munteanu D, Graur F. Laparoscopic cholecystectomy: incidents and complications. A retrospective analysis of 9542 consecutive laparoscopic operations. HPB (Oxford) 2003;5:152–158.[PMC free article][PubMed]
58. Pokorny WJ, Saleem M, O’Gorman RB, McGill CW, Harberg FJ. Cholelithiasis and cholecystitis in childhood. Am J Surg. 1984;148:742–744.[PubMed]
Writers Workshop: Writer Resources
Writing Tips: Thesis Statements
Defining the Thesis Statement
What is a thesis statement?
Every paper you write should have a main point, a main idea, or central message. The argument(s) you make in your paper should reflect this main idea. The sentence that captures your position on this main idea is what we call a thesis statement.
How long does it need to be?
A thesis statement focuses your ideas into one or two sentences. It should present the topic of your paper and also make a comment about your position in relation to the topic. Your thesis statement should tell your reader what the paper is about and also help guide your writing and keep your argument focused.
Questions to Ask When Formulating Your Thesis
Where is your thesis statement?
You should provide a thesis early in your essay -- in the introduction, or in longer essays in the second paragraph -- in order to establish your position and give your reader a sense of direction.
Tip: In order to write a successful thesis statement:
- Avoid burying a great thesis statement in the middle of a paragraph or late in the paper.
- Be as clear and as specific as possible; avoid vague words.
- Indicate the point of your paper but avoid sentence structures like, “The point of my paper is…”
Is your thesis statement specific?
Your thesis statement should be as clear and specific as possible. Normally you will continue to refine your thesis as you revise your argument(s), so your thesis will evolve and gain definition as you obtain a better sense of where your argument is taking you.
Tip: Check your thesis:
- Are there two large statements connected loosely by a coordinating conjunction (i.e. "and," "but," "or," "for," "nor," "so," "yet")?
- Would a subordinating conjunction help (i.e. "through," "although," "because," "since") to signal a relationship between the two sentences?
- Or do the two statements imply a fuzzy unfocused thesis?
- If so, settle on one single focus and then proceed with further development.
Is your thesis statement too general?
Your thesis should be limited to what can be accomplished in the specified number of pages. Shape your topic so that you can get straight to the "meat" of it. Being specific in your paper will be much more successful than writing about general things that do not say much. Don't settle for three pages of just skimming the surface.
The opposite of a focused, narrow, crisp thesis is a broad, sprawling, superficial thesis. Compare this original thesis (too general) with three possible revisions (more focused, each presenting a different approach to the same topic):
- Original thesis:
- There are serious objections to today's horror movies.
- Revised theses:
- Because modern cinematic techniques have allowed filmmakers to get more graphic, horror flicks have desensitized young American viewers to violence.
- The pornographic violence in "bloodbath" slasher movies degrades both men and women.
- Today's slasher movies fail to deliver the emotional catharsis that 1930s horror films did.
Is your thesis statement clear?
Your thesis statement is no exception to your writing: it needs to be as clear as possible. By being as clear as possible in your thesis statement, you will make sure that your reader understands exactly what you mean.
Tip: In order to be as clear as possible in your writing:
- Unless you're writing a technical report, avoid technical language. Always avoid jargon, unless you are confident your audience will be familiar with it.
- Avoid vague words such as "interesting,” "negative," "exciting,” "unusual," and "difficult."
- Avoid abstract words such as "society," “values,” or “culture.”
These words tell the reader next to nothing if you do not carefully explain what you mean by them. Never assume that the meaning of a sentence is obvious. Check to see if you need to define your terms (”socialism," "conventional," "commercialism," "society"), and then decide on the most appropriate place to do so. Do not assume, for example, that you have the same understanding of what “society” means as your reader. To avoid misunderstandings, be as specific as possible.
Compare the original thesis (not specific and clear enough) with the revised version (much more specific and clear):
- Original thesis: Although the timber wolf is a timid and gentle animal, it is being systematically exterminated. [if it's so timid and gentle -- why is it being exterminated?]
- Revised thesis: Although the timber wolf is actually a timid and gentle animal, it is being systematically exterminated because people wrongfully believe it to be a fierce and cold-blooded killer.
Does your thesis include a comment about your position on the issue at hand?
The thesis statement should do more than merely announce the topic; it must reveal what position you will take in relation to that topic, how you plan to analyze/evaluate the subject or the issue. In short, instead of merely stating a general fact or resorting to a simplistic pro/con statement, you must decide what it is you have to say.
- Avoid merely announcing the topic; your original and specific "angle" should be clear. In this way you will tell your reader why your take on the issue matters.
- Original thesis: In this paper, I will discuss the relationship between fairy tales and early childhood.
- Revised thesis: Not just empty stories for kids, fairy tales shed light on the psychology of young children.
- Avoid making universal or pro/con judgments that oversimplify complex issues.
- Original thesis: We must save the whales.
- Revised thesis: Because our planet's health may depend upon biological diversity, we should save the whales.
- When you make a (subjective) judgment call, specify and justify your reasoning. “Just because” is not a good reason for an argument.
- Original thesis: Socialism is the best form of government for Kenya.
- Revised thesis: If the government takes over industry in Kenya, the industry will become more efficient.
- Avoid merely reporting a fact. Say more than what is already proven fact. Go further with your ideas. Otherwise… why would your point matter?
- Original thesis: Hoover's administration was rocked by scandal.
- Revised thesis: The many scandals of Hoover's administration revealed basic problems with the Republican Party's nominating process.
Do not expect to come up with a fully formulated thesis statement before you have finished writing the paper. The thesis will inevitably change as you revise and develop your ideas—and that is ok! Start with a tentative thesis and revise as your paper develops.
Is your thesis statement original?
Avoid, avoid, avoid generic arguments and formula statements. They work well to get a rough draft started, but will easily bore a reader. Keep revising until the thesis reflects your real ideas.
Tip: The point you make in the paper should matter:
- Be prepared to answer “So what?” about your thesis statement.
- Be prepared to explain why the point you are making is worthy of a paper. Why should the reader read it?
Compare the following:
- Original thesis:
- There are advantages and disadvantages to using statistics. (a fill-in-the-blank formula)
- Revised theses:
- Careful manipulation of data allows a researcher to use statistics to support any claim she desires.
- In order to ensure accurate reporting, journalists must understand the real significance of the statistics they report.
- Because advertisers consciously and unconsciously manipulate data, every consumer should learn how to evaluate statistical claims.
Avoid formula and generic words. Search for concrete subjects and active verbs, revising as many "to be" verbs as possible. A few suggestions below show how specific word choice sharpens and clarifies your meaning.
- Original: “Society is...” [who is this "society" and what exactly is it doing?]
- Revised: "Men and women will learn how to...," "writers can generate...," "television addicts may chip away at...," "American educators must decide...," "taxpayers and legislators alike can help fix..."
- Original: "the media"
- Revised: "the new breed of television reporters," "advertisers," "hard-hitting print journalists," "horror flicks," "TV movies of the week," "sitcoms," "national public radio," "Top 40 bop-til-you-drop..."
- Original: "is, are, was, to be" or "to do, to make"
- Revised: any great action verb you can concoct: "to generate," "to demolish," "to batter," "to revolt," "to discover," "to flip," "to signify," "to endure..."
Use your own words in thesis statements; avoid quoting. Crafting an original, insightful, and memorable thesis makes a distinct impression on a reader. You will lose credibility as a writer if you become only a mouthpiece or a copyist; you will gain credibility by grabbing the reader with your own ideas and words.
A well-crafted thesis statement reflects well-crafted ideas. It signals a writer who has intelligence, commitment, and enthusiasm.