gastric adenocarcinoma is a cancer of the stomach that is the next most common cancer after lung cancer in the world. it is more common in males compared to females by 2:1 (although dr. thom's experience says more 1:1), and usually presents in ages 50-70. GA is highly prevalent in certain countries-- in particular, a high incidence in japan suspected to be linked to large nitrite use as preservative. within the US, GA is more common in african americans, hispanics, and native americans as compared to white americans. anyone who has a diet high in salt or nitrites has increased susceptibility towards developing GA, as does a sufferer of hypochlorhydria (decreased acid leads to imbalanced flora leads to more nitrite formation). people with h. pylori infection are 3-6 more likely to develop GA as well.
GA can be difficult to diagnose and only show up in its later stage, leading to a poor prognosis (10% 5 year survival rate). the early stage may be asymptomatic or nonspecific; vague epigastric discomfort or nausea, while the late stage presents with symptoms of advanced gastric cancer. this might include digestive difficulties (nausea, dysphagia, vomiting), systemic changes (lack of appetite, fatigue, weakness), and bleeding issues (melena, hematemesis). on a PE, GA patients might present with a palpable mass, abdominal tenderness, hepatomegaly, and ascites. in the lab, they might present with iron deficiency anemia, positive occult blood, and elevated ALT (from liver damage) / bilirubin / CEA.
the next section of the GI lectures went into general diagnostic ideas for GI issues, starting with differentiating the presentation of abdominal pain from various organs. an esophageal issue such as perforation would manifest substernally. a stomach ulcer would present in the LUQ while a duodenal ulcer would present in the RUQ. small intestine obstruction would present periumbilically while colon obstruction (or appendicitis, diverticulitis, cancer) would present below the umbilicus. splenic flexure pain would present in the LUQ and might be from diverticulitis or ruptured spleen. rectosigmoid would manifest in the suprapubic area, maybe from diverticulitis. rectal issues such as an anal fistula would show up over the sacral area. pancreatitis would present with pain in the epigastric region, and possibly the thoracic spine as well as left scapula. liver / gall bladder issues would present in the RUQ, possibly radiating to the right shoulder and could be from adenoma, gallstones, cholecystitis.
digestive efficiency is the sum of many independent processes and can be measured by any of these: pancreatic function, fat absorption, carb absorption, gut motility, fecal pH and content. pancreas function is measured via chymotrypsin and elastase. gut motility is broken down into two aspects: transit time, the time it takes for ingested food to first start exiting the GI system, and the retention time, the additional time that is needed for the entire meal to be digested and excreted. transit time is normally 20-30 hours and a shorter time would result in incomplete digestion and might be the result of imbalanced flora. retention time is 50-72 hours and a shorter time results from a tonic, spastic colon while a longer time results from an atonic, limp colon. both result in improper mixing and incomplete digestion.
the function of the mucosal barrier screen can be measured in several ways as well, such as intestinal IgA levels, lysozyme, alpha anti chymotrypsin, and the anti-gliadin antibody. low IgA levels can point to either deficient production, suppression, or high IgA use: food allergies, parasites, stress, are all factors. high IgA levels can indicate a fast transit time, and a short transit time can indicate the opposite. fecal lysozyme is an indicator of colonic inflammation and intestinal alpha anti-chymotrypsin is an indicator for small intestine involvement.
some last notes on the different microorganisms that colonize the gut: giardia can live underneath the fingernails of an infected person for up to 3 months ("if the cook in the family has it, the whole family has it"). cryptosporidium is nearly ubiquitious in water wupplies. entameba histolytica antibody can be detected in the saliva, stool, and serum and can indicate an ongoing GI infection (stool) or an extraintestinal infection (serum). c. difficile is present in about 3% of stool samples, while klebsiella pneumonia is in 40% of infants and 30% of adults, as is h. pylori. in general, the composition of the microflora depends on several host factors: peristaltic characteristics, mucous composition, concentration of bile / acid / O2, carbohydrate composition, and reactivity with the host immune system.
questions
gastric adenocarcinoma introduction and risk factors...
1. how common is a gastric adenocarcinoma?
2. what is the general pathogenesis of adenocarcinoma?
3. which country has a particularly increased risk for adenocarcinoma?
4. compare the incidence of gastric adenocarcinoma of different racial groups within the US.
5. what are some dietary risk factors for gastric adenocarcinoma?
6. what effect does hypochlorhydria have on gastric adenocarcinoma?
7. describe the effect of h. pylori infection regarding the risk of developing gastric adenocarcinoma.
8. what is the typical age for GA?
GA diagnosis...
9. what are the symptoms during the early stages of GA?
10. what are the symptoms of the late stages of GA?
11. what are the physical exam findings of GA?
12. what are some possible lab findings for GA?
13. what are the imaging techniques used to diagnose GA?
14. what is the prognosis of GA?
where in the abdomen would issues of the following organs manifest and what may they be from?
15. esophagus.
16. stomach.
17. duodenal bulb.
18. small intestine.
19. colon.
20. splenic flexure.
21. rectosigmoid.
22. rectum.
23. pancreas.
24. liver / GB.
measuring digestive efficiency...
25. what are the procedures for an intake of a patient with GI symptoms and what is the best order to do things in?
26. what are some general measures of digestion efficiency?
27. what are two tests to perform as a measure of pancreatic efficiency?
28. what is a normal transit time and what might a fast transit time indicate?
29. what is a normal retention time?
30. what might an abnormally short and long retention time indicate?
mucosal barrier screen...
31. what are some measures that can assess the functioning of the mucosal barrier screen?
32. what can be the cause of low or reduced intestinal IgA?
33. how does transit time affect IgA levels?
34. what does the fecal lysozyme test indicate?
35. what does intestinal alpha anti-chymotrypsin indicate?
36. what do anti-gliadin antibody levels indicate?
microflora...
37. what are the four main ways for evaluating a yeast or fungal infection of the GI tract?
38. how long can giardia live underneath the fingernails?
39. cryptosporidium is a potential problem for...
40. what is the reservoir for cryptosporidium?
41. what does the presence of IgA entameba histolytica imply in the stool, saliva, and serum?
42. how common is the positive finding of clostridium difficile in a stool sample?
43. how common is klebsiella pneumonia in infant and adult intestinal flora?
44. how common is h. pylori in the GI tract?
45. what are the factors that are responsible for the distribution of microflora in the gut?
answers
1. the next most common cancer after lung cancer.
2. gastritis, atrophic gastritis, metaplasia, dysplasia, carcinoma.
3. japan.
4. 1.5-2.5 more common in african americans, hispanics, native americans compared to caucasians.
5. high salt intake, nitrates.
6. promotes bacterial colonization in the stomach and nitrite formation, leading to increased risk for GA.
7. 3-6 times more likely to develop gastric adenocarcinoma.
8. 50-70 years old.
9. nonspecific, usually asymptomatic, maybe vague epigastric discomfort, nausea.
10. signs of advanced gastric cancer:
• dysphagia, pain, bloating, vomiting upon eating
• fatigue, weakness, weight loss d/t decreased appetite
• upper GI bleeding symptoms- melena, hematemesis, occult bleeding
[georgia eats, gets tired and bleeds]
11. palpable mass, tender abdomen, hepatomegaly, ascites.
12. fe deficiency anemia, occult blood, elevated alkaline phosphatase, bilirubin (hepatomegaly), elevated CEA. [blood, blood, ALT, bili, CEA] [bill bled blood in the elevator of the CIA building in georgia]
13. endoscopy, xray, CT.
14. very poor; 10% 5 year survival.
15. substernal, perforation.
16. LUQ, perforated gastric ulcer.
17. RUQ, perforated duodenal ulcer.
18. periumbilical, obstruction.
19. below umbilicus, appendicitis, diverticulitis, cancer, obstruction.
20. LUQ, diverticulitis, ruptured spleen.
21. suprapubic, diverticulitis,
22. over sacrum, anal fistula.
23. epigastric / thoracic spine / L scapula, from pancreatitis.
24. RUQ / R shoulder and scapula / thoracics, from adenoma, gallstones, cholecystitis.
25. history, PE, labs, imaging.
26. digestive efficiency:
pancreatic function
fat, carb absorption
gut motility - transit and retention time
occult blood
fecal pH
27. chymotrypsin, elastase levels.
28. 20-30 hours, faster might indicate imbalanced flora.
29. 50-72 hours.
30. short: spastic, tonic, no mixing. long: atonic, no mixing, poor muscle tone.
31. intestinal IgA, fecal lysozyme, intestinal alpha anti-chymotrypsin, anti-gliadin antibody.
32. deficient production, food allergies, parasites, suppression from cortisol, reduced villi height.
33. longer transit time decreases IgA levels and shorter increases them.
34. inflammation of the colon.
35. small intestine involvement.
36. reaction to gliadin can indicate mild enteritis to full blown celiacs.
37. microscopy, culture, serum antigens, antibodies.
38. 3 months via cysts despite hand washing.
39. immunocompromised patients.
40. most water supplies have cryptosporidium.
41. stool: commensal, gut infection. saliva: invasive ongoing, gut infection. serum: extraintestinal, like the liver.
42. 3% of adults.
43. 40% infants, 30% adults.
44. about 1/3 of us have it.
45. peristaltic wave
mucus composition
bile, acid, O2 concentration
substrate availability
growth factor availability
microorganism reactivity with immune system
No comments:
Post a Comment