From brain to bile. Evidence that conjugation and omega-hydroxylation are important for elimination of 24S-hydroxycholesterol (cerebrosterol) in humans.
(1/54)
The brain is the almost exclusive site of formation of 24S-hydroxycholesterol in man, and there is a continuous flux of this oxysterol across the blood-brain barrier into the circulation. The hepatic metabolism of 24S-hydroxycholesterol was studied here by three different approaches: incubation of tritium-labeled 24S-hydroxycholesterol with human primary hepatocytes, administration of tritium-labeled 24S-hydroxycholesterol to a human volunteer, and quantitation of free and conjugated 24S-hydroxycholesterol and its neutral metabolites in ileocecal fluid from patients with ileal fistulae. 24S-Hydroxycholesterol as well as 24R-hydroxycholesterol were converted into bile acids by human hepatocytes at a rate of about 40% of that of the normal intermediate in bile acid synthesis, 7 alpha-hydroxycholesterol. There was also a conversion of 24S-hydroxycholesterol into conjugate(s) of 5-cholestene-3 beta,24S,27-triol at a rate similar to the that of conversion into bile acids. When administered to a human volunteer, labeled 24S-hydroxycholesterol was converted into bile acids at about half the rate of simultaneously administered labeled 7 alpha-hydroxycholesterol. Free, sulfated, and glucuronidated 24S-hydroxycholesterol and 5-cholestene-3 beta,24,27-triol were identified in ileocecal fluid. The excretion of these steroids was about 3.5 mg/24 h, amounting to more than 50% of the total estimated flux of 24S-hydroxycholesterol from the brain. It is concluded that 24S-hydroxycholesterol is a less efficient precursor to bile acids and that about half of it is conjugated and eliminated in bile as such or as a conjugate of a 27-hydroxylated metabolite. The less efficient metabolism of 24S-hydroxycholesterol may explain the surprisingly high levels of this oxysterol in the circulation and is of interest in relation to the suggested role of 24S-hydroxycholesterol as a regulator of cholesterol homeostasis. (+info)
Progressive bovine paratuberculosis is associated with local loss of CD4(+) T cells, increased frequency of gamma delta T cells, and related changes in T-cell function.
(2/54)
Bovine paratuberculosis is caused by the infection of young calves with Mycobacterium avium subsp. paratuberculosis, resulting in a chronic granulomatous infection of predominantly the ileum. After an incubation period of 2 to 5 years, the disease becomes progressive in some of the chronically infected, but asymptomatic cows. This results in a protein-losing enteropathy that will ultimately be fatal. A loss of cell-mediated immune responses in symptomatic animals has been described, but no information is available concerning immune reactivity in the intestine. We sought to investigate putative disease status-associated lymphocyte subset distributions and antigen-specific functional characteristics of mononuclear cells isolated from blood, gut-associated lymphoid tissue, and the intestinal walls of 22 cows in different stages of disease and in control animals. The results demonstrated a significant decrease in CD4(+) T-cell frequency and a significant increase in TcR1-N12(+) gamma delta T-cell frequency in ileum lamina propria lymphocytes of symptomatic animals compared to the asymptomatic shedders. Immunohistology revealed that there was also an absolute decrease in the number of CD4(+) T cells in sections of the lesional ileum. Our findings also indicated that both peripheral and intestinal cell-mediated responses are decreased in symptomatic animals compared to asymptomatic animals. We conclude that the decrease in cell-mediated responses is likely related to a loss of antigen-specific CD4(+) T cells, which is most prominent in the lesional ileum from symptomatic animals, thus contributing to the progressive nature of bovine paratuberculosis. (+info)
Studies on the fibercolonoscopy: with special reference to the latest procedures.
(3/54)
The Machida type fibercolonoscope, or FCS, devised by us is an anterior direct vision type of fiberscope. The most important feature of this new fiberscope consists of a tip of 5 cm size which is capable of being directed by flection up to 120 degrees in any direction and the tip up to 30 cm possessing a fishing-rod-like flexibility and elasticity by means of a special spiral spring. This angle-regulating mechanism makes it possible to insert this instrument along the course of the intestine under direct visual control. The fishing-rod-like construction where the maximal flexibility is greatest at the tip makes it considerably easier to pass sites of marked flexure in the colon. At examination the insertion of the instrument is guided by direct observation and by roentgenoscopy. The results in 200 cases in 1970 and thereafter, when operative techniques No. I, II and III devised previously by us were used, showed that successful insertion into the cecum was possible in 139 out of 173 cases (80%) except 27 cases of pathological stenosis due to cancer and other reasons. Thus fibercolonoscopy now enables the direct observation of the colon beyond the reach of the signoidoscope, providing a useful diagnostic procedure. Furthermore, a medium-long fibercolonoscope or FCS-M has been produced by us for examination of the lower portion of the large intestine. This is used in the inverted position without roentgenoscopic guidance as in conventional sigmoidoscopy. When this method, fibersigmoidoscopy, was used in 120 cases, it was possible to examine up to the transverse colon in 19 cases, the splenic flexure in 22 cases and the descending colon in 39 cases without the use of special techniques I, II and III. Thus in the majority of cases it is possible to carry out the examination of the left colon in this manner. The usefulness of fibersigmoidoscopy in the practical clinic is, therefore, rather larger than that of fibercolonoscopy. (+info)
Ileocecal valve as substitute for the missing pyloric sphincter after partial distal gastrectomy.
(4/54)
OBJECTIVES: Accelerated gastric emptying (including dumping syndrome) occurs frequently after gastric resections, largely resulting from rapid entry of meal contents into the small intestine. The authors hypothesized that an ileocecal segment used as an interpositional graft placed between the remaining part of the stomach and the small intestine would slow down food transit and thus replace pyloric function. METHODS: Thirty Gottingen minipigs were randomized into three groups. Group 1: partial gastrectomy and Roux-en-Y reconstruction; Group 2: partial gastrectomy and ileocecal interpositional graft; and Group 3: sham laparotomy. Gastric emptying in the nonsedated animals was quantified using radioscintigraphy at 3 and 6 months postoperatively. The animals ingested 300 grams of soft food containing 99mTc labeled resin- pellets using a technique previously described. Data were analyzed using ANOVA. RESULTS: Three months postoperatively, the ileocecal group had a significantly prolonged gastric emptying time compared with the Roux-en-Y group, but gastric emptying time was also significantly faster compared to the control group (sham laparotomy). After 6 months no significant difference was seen between the ileocecal group and the controls, while emptying rates were still significantly faster in the Roux-en-Y group. CONCLUSIONS: Reconstruction of the gastric reservoir with an ileocecal segment largely restores gastric emptying patterns of food in minipigs. Six months postoperatively, gastric emptying time is similar to that of controls, and significantly slower when compared with the group with Roux-en-Y reconstruction. These results suggest that the ileocecal interposition graft could offer specific advantages over current reconstruction procedures. (+info)
Cecal rupture by Anoplocephala perfoliata infection in a thoroughbred horse in Seoul Race Park, South Korea.
(5/54)
A 7-year-old Thoroughbred horse was admitted to the Equine Hospital, Korea Racing Association with signs of colic. Based on the size of impactions, the clinical signs, the results of abdominal paracentesis and medical treatment, the prognosis was poor. The horse died 3 hours later following hopeless discharge. At necropsy, the caecum and large colon were fully filled with fecal contents and there was a rupture (10 cm in dia) in the latero- ventral caecum. The mucosa of the ileo-caecal and caeco- colic valves appeared to the hyperemic, edematous and ulcerous. There were many tapeworms in the affected mucosa. Histopathologically, lesions included hyperaemia, a deep necrotic inflammatory lesion and ulcers in the mucosa and submucosa of ileo-caecal and caeco-colic valves. One hundred thirty four faecal samples were obtained from 16 stables and submitted to parasitic examination. A total of 4 genera of eggs were recovered: Stongylus spp (82.1%), Anoplocephala perfoliata (10.5%), Bovicola equi (0.7%) and Parascaris equorum (1.5%). The major findings in this study are the presence of A perfoliata and its suspected association with the colic which led into an eventual caecal rupture. This study indicates the needs for an epidemiological survey of colic that is associated with Anoplocephala. (+info)
Cytomegalovirus colitis manifested with a ring like ileocecal valve ulcer in a Korean AIDS patient.
(6/54)
A 32-year-old man, who had no previous medical history, was hospitalized with 3-week duration of abdominal pain, fever, and watery diarrhea. Initial colonoscopy showed subepithelial hemorrhagic spots throughout the entire colon together with well-circumscribed ulcer around the ileocecal valve. Serologic test disclosed HIV-positive and repeated biopsies at ulcer base finally revealed that the patient had cytomegalovirus ulcer in ileocecal area. (+info)
Intussusception as a cause of bowel obstruction in adults.
(7/54)
BACKGROUND: Due to its unspecific presentation, intussusception is often diagnosed with delay in adults. METHODS: From 1986 to 2002, ten patients (men/women: 8/2, median age: 53.6 years) were managed for intussusception. Clinical, radiological and surgical management data were retrospectively analyzed. RESULTS: All patients presented with abdominal symptoms (pain: 10/10, nausea and vomiting: 3/10, diarrhoea: 2/10, "red-currant jelly stool": 2/10) during a median time of 8.3 months (2 days - 6 years) and with a trend for longer duration of symptoms for benign compared to malignant underlying disease (2 years vs 1 month). Two cases had developed acute bowel obstruction at the time of surgery. CT-scan was always performed, with correct diagnosis in seven cases. Ultrasonography (4/10), contrast enema (5/10) or coloscopy (4/10) either missed the intussusception or served merely to confirm the CT diagnosis. At surgery, an underlying lesion (six malignant and four benign tumours) was identified and removed in all cases (four small bowel, three right colon, two ileocaecal and one left colon resections). Eight were undiagnosed previously. CONCLUSIONS: Intussusception is rare in adults, but should be considered in cases of chronic or acute bowel obstructions. Early surgical management allows detection and potential cure of underlying tumours. (+info)
Technical Note: Improved technique for fitting pigs with steered ileocecal valve cannulas.
(8/54)
Collection of ileal digesta to evaluate AA digestibilities has become increasingly important in swine nutrition research. Steered ileocecal valve cannulation of pigs permits total collection of ileal digesta, while still allowing normal digesta flow during noncollection periods. This technique was modified and used with 64 crossbred barrows in five trials. Our procedural changes included preoperative i.v. administration of a broad-spectrum antibiotic and nonsteroidal antiinflammatory drug, sharp incision through the muscle layers of the laparotomy wound, use of a heparinized saline lavage solution, replacement of the guide ring with a stylette, and fixing the outer cannula barrel in place with a hose clamp. The current technique involves a right flank laparotomy, parallel and distal to the last rib, with the pig under general anesthesia. A stainless-steel ring (inner ring = 2.0 mm thick, 35.0 mm i.d.) is introduced into the ileal lumen through an enterotomy proximal to the origin of the ileocecal fold. A nylon string attached to this ring is threaded through the ileum and ileocecal valve into the cecum using a silastic stylette, which encases the string. A second stainless-steel ring (outer ring = 2.0 mm thick, 34 mm o.d.) is fixed in place around the ileum, distal to the inner ring and just proximal to the ileocecal valve. A polyurethane cannula barrel (barrel = 100 mm long, 26 mm i.d., 32 mm o.d.; flange = 70 mm o.d.) is introduced into the cecal lumen via an enterotomy through the lateral cecal band and secured in place with two purse-string sutures. The cannula is exteriorized through an incision caudal and proximal to the intial laparotomy site, where it is plugged using a cylindrical stopper (26 mm o.d., 55 mm long) and held in place by a second cannula barrel (barrel = 43 mm length, 33 mm i.d., 41 mm o.d.; flange = 80 mm o.d.). Procedural changes decreased postsurgical complications, as evidenced by decreased seepage around the cannula and fewer and less severe adhesions noted at necropsy. Based on five trials, this technique is a reliable means of collecting ileal digesta for nutrient analyses. (+info)