PubMed Health⌕ Search

Biomedical subjects

C Arvanitakis

Publications and source records attributed to C Arvanitakis.

At least 37 records · Page 2Linked to original sources
PubMed1978

Characterization of p-aminobenzoic acid transport across the rat intestine.

The intestinal absorption of PABA, a member of the vitamin B complex, was characterized in vivo and in vitro in the rat by the segmental intestinal perfusion and everted gut sac technique. Net PABA absorption was directly proportional to substrate concentration, and saturation of absorption did not occur with increasing concentrations of PABA (1 to 50 mM), indicating a nonsaturable process. Jejunal and ileal absorption rates were similar and were not influenced by the presence of glucose or the absence of sodium in the test solution. Similarly, 14C-PABA transport in vitro was nonsaturable and proportional to PABA concentration (0.05, 0.5, 1, 10, and 50 mM). It was not inhibited by ouabain or other PABA analogues such as folic acid and benzoic acid. These studies indicate that PABA, a vitamin B cofactor, is absorbed by a nonsaturable, sodium-independent process, which characterizes passive diffusion and is similar to the absorption of other vitamin B members.

4-Aminobenzoic Acid↗
PubMed1978

Secretory immunoglobulin deficiency in a family with inflammatory bowel disease.

A family with 4 of 10 first-degree relatives affected with inflammatory bowel disease (IBD) was studied to determine whether any distinct immunological abnormalities occur in the affected members, as compared with unaffected members of the family, normal controls, and other unrelated patients with IBD. Red cell blood type and HL-A phenotypes did not distinguish between healthy and affected members, although HL-A2, 32, B27, and B12 were the predominant haplotypes in members with IBD. There was no significant difference between the two groups in the lymphocyte subpopulation counts of T cells, B cells, and cells carrying Fc or complement receptors. The in vitro mitogen response, however, to phytohemagglutinin and pokeweed mitogen were depressed in the affected members. Serum IgA and C3 levels were significantly elevated in members with IBD compared to healthy subjects with values of 232 +/- 69 (mean +/- SD) versus 148 +/- 29 mg per dl for IgA (P less than 0.05) and 173 +/- 32 versus 115 +/- 22 mg per dl for C3 (P less than 0.025), respectively. Plasma and, to a lesser extent, peripheral lymphocytes from 2 affected members who were tested were cytotoxic to allogeneic colonic epithelial cells. Salivary IgA was normal in the affected family members and unrelated patients with IBD. However, the free secretory component of salivary IgA was absent or markedly depressed in family members, as well as in unrelated patients with ulcerative colitis. This deficiency of the secretory immune system appears to characterize more frequently ulcerative colitis than Crohn's disease and may compromise mucosal host defenses in IBD.

Adolescent↗
PubMed1978

Functional and morphological abnormalities of the small intestinal mucosa in pernicious anemia--a prospective study.

Small intestinal mucosal function and structure was investigated in 13 patients with pernicious anemia prior to and after treatment with vitamin B12. Histological abnormalities of the jejunal mucosa were shortening of villi of varying degree, increased infiltrate of the lamina propria with monocytes and plasma cells and megalocytosis of the absorptive epithelial cell. Malabsorption of d-xylose occurred in 45%, fat in 30%, vitamin B12-IF complex in 69%, hypocarotinemia in 23% and hypoalbuminemia in 30% of the patients. By contrast, digestive brush border enzymes, i.e. disaccharidases, alkaline phosphatase and leucyl-naphthylamidase were not altered in pernicious anemia. Patients with significant jejunal mucosal abnormalities and decrease of the absorptive surface demonstrated malabsorption of one or more nutrients. Morphological and functional abnormalities were restored to normal after treatment with vitamin B12, suggesting that small intestinal changes in pernicious anemia constitute primary systemic manifestations.

Aged↗
PubMed1977

Treatment of toxic megacolon. A comparative review of 29 patients.

A review of 29 patients with toxic megacolon complicating ulcerative colitis was undertaken to (1) compare the results of medical and surgical treatment; (2) determine the optimal timing for surgical intervention, and (3) identify possible precipitating factors. Twenty-one patients were treated medically with nasogastric suction, steroids, parental fluids, blood transfusions, and antimicrobial agents. Of the 21 patients, 11 (53%) showed improvement by subjective and objective criteria and 10 (47%) failed to respond. Sixteen patients were treated surgically. This group was subdivided into 8 patients who failed to respond to medical treatment and 8 treated surgically. Total proctocolectomy with ileostomy was performed in 8 and subtotal colectomy and ileoproctostomy in 8, with subsequent proctectomy and ileostomy in 6 patient. Six of 8 patients (75%) treated primarily surgically improved, and 2 (25%) died. Seven of 8 patients (87.5%) treated surgically after failure of medical trial showed definite postoperative improvement, and 1 (12.5%) failed. Those who were operated on within the first 48-72 hr after the diagnosis of toxic megacolon was made responded uniformly well. Anticholinergics, opiates,, barium enema, and colonoscopy were identified as possible precipitating factors in 70% of cases. The results of this tudy in this patient population indicate that early surgical therapy in toxic megacolon is associated with better results than medical therapy (P less than 0.025). Although intensive, optimal medical therapy plays a significant role in the management of toxic megacolon, failure to induce rapid improvement within 48-72 hr constitutes an indication for definitive surgical treatment.

Adolescent↗
PubMed1977

Recurrent colonic ulcers in celiac sprue, an unrecognized fatal complication: report of a case.

In a patient who had celic sprue intractable to a gluten-free diet, volvulus and jejunal and colonic ulcers developed. Following segmental colonic resection, these ulcers recurred at the site of the previous anastomosis, and proved a fatal complication because of colonic perforation. Since no obvious etiology of colonic ulcers could be identified in this case, it is possible that they may represent an unrecognized intestinal complication of celiac sprue similar to jejunoileal ulcers.

Adult↗
PubMed1977

Lactase deficiency--a comparative study of diagnostic methods.

The diagnostic value of 1-14C-lactose breath test was compared with the standard lactose tolerance test and lactase assay in jejunal biopsies in 16 control subjects, 14 patients with lactase deficiency (LD) proven by lactase assay and 20 patients with irritable bowel syndrome (IBS). 14CO2 specific activity in the 2-hr breath collection after administration of 1-14C-lactose (5 muCi) provided a satisfactory separation between the control and LD group. Values were 7.0 +/- 2.0% dose administered/mmoles 14CO2 X 10(-3) (mean +/- SD) in the control group versus 2.1 +/- 1.5 in LD (P less than 0.001) versus 4.9 +/- 2.3 in IBS (P less than 0.01). 1-14C-lactose breath test was superior to standard lactose tolerance test in specificity (P less than 0.05) and provided a satisfactory correlation between 14C-lactose absorption and lactase assay (r = 0.77). The prevalence of LD in IBS was 40% by the breath test and 35% by lactase assay, suggesting that lactose malabsorption may play a role in the symptoms in the population of some patients with IBS. It appears that 1-14C-lactose breath test is a sensitive, specific and accurate method for the diagnosis of LD in clinical practice and suitable for large scale epidemiological surveys.

Breath Tests↗
PubMed1977

Effect of aspirin on intestinal absorption of glucose, sodium, and water in man.

The effect of aspirin on small intestinal function in six healthy volunteers was examined using a segmental perfusion technique, with a test solution of 40 mM D-glucose, 140 mM NaCl, and 0-5% polyethylene glycol. Jejunal glucose, sodium, and water absorption rates were inhibited by 50% after oral administration of 2-6 g aspirin. Adenosine triphosphate (ATP) concentration was assayed in jejunal mucosal biopsies before and after aspirin. There was an almost 50% decrease in mucosal ATP levels after aspirin. This effect may be mediated through cellular injury and impairment of mitochondrial energy metabolism. These data suggest that aspirin may significantly alter small intestinal function. It appears possible that the inhibitory effect of aspirin on glucose absorption may account, at least in part, for the lower blood sugar levels observed with the use of the drug.

Adenosine Triphosphate↗
PubMed1976

The role of metoclopramide in peroral jejunal biopsy: a controlled randomized trial.

Metoclopramide is known to enhance gastric emptying and stimulate duodenal and small-intestinal peristaltic activity. The effect of the drug on peroral jejunal biopsy was examined in a controlled, double-blind, randomized trial. Forty-nine patients (24 females and 25 males) who required jejunal biopsy for diagnostic purposes were admitted to the study. All the biopsies were performed by the same operator using the Quinton multipurpose suction biopsy tube and applying the same technique. Twenty-four patients ranging in age from 18 to 67 years (mean 44.5) received placebo intravenously (sodium metabisulfite), and 25 patients from 16 to 73 years old (mean 39.9) received 10 mg of metoclopramide intravenously prior to the jejunal intubation. Objective parameters of the study were (1) time in minutes required for the intubation at the biopsy site, ie, the area at the ligament of Treitz, and (2) fluoroscopy time. Intubation time in the placebo group was 22.3 +/- 1.9 min (mean +/- SEM) vs 11.3 +/- 1.4 min in the metoclopramide group (P less than 0.001). Fluoroscopy exposure time was 2.47 +/- 0.25 in the placebo group vs 1.40 +/- 0.12 min in the metoclopramide group (P less than 0.001). Subjective clinical evaluation of the operator's assessment of the procedure was based on a 0-4 scale (much easier = 0, easier = 1, average = 2, harder = 3, and much harder = 4). Metoclopramide administration resulted in a significantly easier performance of the procedure (P less than 0.001) but did not influence patient tolerance. Three patients who received metoclopramide and one receiving placebo developed mild to moderate drowsiness of short duration. The results of this controlled trial indicate that metoclopramide significantly shortens the time required for jejunal biopsy and reduces fluoroscopy exposure. Its regulatory action on gastrointestinal motility contributes to the easier performance of a valuable diagnostic procedure.

Adolescent↗
PubMed1976

Digestion of tripeptides and disaccharides: relationship with brush border hydrolases.

Intestinal digestion of two tripeptides (leucyl-glycyl-glycine, prolyl-glycyl-glycine) and two disacchrarides (sucrose, maltose) was examined in the hamster by intestinal perfusion in vivo and hydrolysis of the substrates by microvillus membranes. Perfusion studies showed that luminal disappearance rates of leucyl-glycl-glycine were significantly higher than prolyl-glycyl-glycine (P less than o.001), sucrose (P less than 0.001), and maltose (P less than 0.005). Hydrolytic products of leucyl-glycyl-glycine, sucrose, and maltose were detected in the gut lumen in appreciable concentrations, whereas negligible concentrations of prolyl-glycyl-glycine products were present. Leucyl-glycyl-glycine hydrolysis in microvillus membranes was markedly higher than prolyl-glycyl-glycine (P less than 0.001), which was predominant in the cytoplasmic fraction. These results indicate that leucyl-glycyl-glycine, like sucrose and maltose, is hydrolyzed at the membrane. With some tripeptides, i.e., leucyl-glycyl-glycine, digestion occurs at the microvillus membrane with subsequent transport of hydrolytic products into the intestinal epithelial cell. Other tripeptides, i.e., prolyl-glycyl-glycine, may cross the membrane and undergo intracellular hydrolysis by cytoplasmic peptidases.

Alkaline Phosphatase↗
PubMed1975

Achalasia of the esophagus. A reappraisal of esophagomyotomy vs forceful pneumatic dilation.

56 patients with achalasia of the esophagus were reviewed in a retrospective study to compare the results of a forceful pneumatic dilation with those of a Heller esophagomyotomy. 22 of 33 patients treated with forceful dilation (67%), showed relief of dysphagia and reduction in the average esophageal diameter by barium swallow during the follow-up period (mean = 6.5 years). In 2 patients (6%), forceful dilation was complicated by esophageal perforation, promptly diagnosed, and successfully treated at surgery in both patients. 21 out of 23 patients who underwent esophagomyotomy (91%) showed permanent relief of symptoms and improvement by endoscopic and radiographic criteria. There were no significant postoperative complications during the follow-up period ranging between 1.5 and 10.0 years. The results of this study indicate that esophagomyotomy constitutes a more effective therapeutic modality than forceful dilation (P less than 0.05). Although esophageal dilation has a place in the treatment of early achalasia, esophagomyotomy appears to be a safer and a more successful form of treatment, of particular value in advanced esophageal disease and in those instances where pneumatic dilation fails to result in immediate clinical improvement.

Adult↗