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Biomedical subjects

I Segal

Publications and source records attributed to I Segal.

At least 19 recordsLinked to original sources
PubMed1992

Choledochoduodenal fistula from a penetrating duodenal ulcer. A case report.

Choledochoduodenal fistula is an uncommon complication of duodenal ulcer disease. The role of medical therapy is unclear and surgical management has been recommended for the condition. A patient who was treated with ranitidine 150 mg twice daily for 8 weeks for a giant duodenal ulcer with a choledochoduodenal fistula is reported. Both the ulcer and the fistula completely healed on medical therapy. Medical therapy may now become the treatment of choice for this condition due to the availability of potent acid-reducing agents.

Adult↗
PubMed1992

Oesophageal cancer in three regions of South Africa.

Cancer of the oesophagus is the commonest cancer in South African black males. The highest incidence rates occur in the south of Transkei. The rate among urban blacks, especially in Soweto, is also high. This study determined risk factors for oesophageal cancer in patients in three different environments--urban Soweto, rural Ciskei and rural-urban Bophuthatswana. Males were affected more than females. The majority of patients in all three regions were smokers. With regard to alcohol consumption, most Sowetans (84%) and Ciskeians (91%), but only 57% of patients from Bophuthatswana, were drinkers. Home-brewed drinks were the main source of alcohol. Oesophageal cancer occurs in both rural and urban environments, affects people without regard to tribal ethnicity, and occurs mainly in the 6th decade; moreover, almost all patients present with advanced disease.

Age Factors↗
PubMed1992

Pancreatic ascites and effusion. Risk factors for failure of conservative therapy and the role of octreotide.

The possible risk factors for failure of medical therapy were examined in 23 patients with pancreatic ascites or effusion. The ascites or effusion resolved completely in 10 patients after a mean (+/- SEM) of 30 +/- 2 days of conventional medical treatment. In five patients in whom conventional medical therapy failed, the addition of an octreotide (SMS 201-995) analogue to the medical therapy led to a resolution of the ascites (three patients) or effusion (two patients). Six patients underwent surgery after failed medical therapy, one patient died while receiving conservative therapy, and one patient refused hospital treatment. Serum sodium and albumin levels were significantly lower, and the ratio of total fluid protein to total serum protein was significantly higher in the group that failed to heal in response to conventional medical therapy. Nine of 11 patients with mild to moderately severe chronic pancreatitis healed in response to conservative therapy. Only one of 10 patients with advanced pancreatitis healed in response to conventional medical therapy. Our results suggest that a selective surgical approach is warranted to treat pancreatic ascites and effusion. In patients with mild or moderately severe pancreatitis, medical therapy is recommended. Patients with advanced pancreatic disease should be selected for early surgery. Octreotide may be useful in the patient in whom surgery may be associated with a prohibitive morbidity or mortality.

Ascites↗
PubMed1992

Colonic pH: a comparison between patients with colostomies due to trauma and colorectal cancer.

Colonic pH is important in the regulation of colonic cell growth, control of absorption and secretion, and bile acid degradation, which may be a key step in the development of colon cancer. This study determined the mucosal, luminal, and fecal pH in right and left colons of otherwise healthy patients who underwent colostomies because of trauma. The pH was evaluated while patients consumed a western diet. In addition, the mucosal, luminal, and fecal pH in patients with colostomies carried out for colorectal cancer also was assessed. All patients were blacks--a low-risk group for colorectal cancer. The results showed that mucosal pH was alkaline (pH 8) and was similar on both sides of the colon of healthy colostomates and in colon cancer patients. Luminal pH (7.6) was the same in healthy right colostomates and cancer patients and was significantly lower that mucosal pH. Fecal pH was significantly lower in right colostomates (6.0) than in left (6.5), and in healthy right colostomates compared with colon cancer patients (6.6). In addition, fecal pH was significantly lower than mucosal and luminal pH.

Adult↗
PubMed1991

Malabsorption of carbohydrate foods by urban blacks.

Prevalences of non-infective bowel diseases are very low in South African urban blacks compared with the white population. In seeking elucidation, using breath hydrogen measurements in series of black and white subjects, small-bowel transit time was determined, and the malabsorption of maize, wheat, and rice investigated. Median transit times in both ethnic groups were similar. Rice was fully, but wheat incompletely absorbed by both groups. Maize, the staple food of blacks, was incompletely absorbed by them, although completely absorbed by the white subjects. Carbohydrate consumption is high in the black population (60-65% of total energy intake). It is probable that in blacks, despite their now eating a low-fibre diet, an expected increase in large-bowel diseases has been inhibited in part by the protective mechanism of fermentation of malabsorbed maize and wheat.

Adult↗
PubMed1991

Glycaemic responses to different carbohydrate foods in healthy and diabetic blacks in Soweto.

Diabetes mellitus is uncommon in rural southern African blacks. With urbanisation and lifestyle changes, incidence rises to that in western populations. To assess associated changes in carbohydrate metabolism, glycaemic responses to glucose, refined maize, refined rice and bread were studied in 8 healthy and 8 non-insulin-dependent diabetic urban blacks. Additionally, in the healthy group serum insulin responses were measured. In the healthy, maize (the staple food of blacks) elicited the highest glucose response (207 mmol/l/min) and bread the lowest (107 mmol/l/min). The glycaemic indices of maize and glucose were similar. Serum insulin responses to maize were significantly lower than that of bread at 90 minutes (maize 66 muU/ml; bread 93 muU/ml; P = 0.02). In diabetics, maize and glucose elicited similar glycaemia (928 mmol/l/min and 921 mmol/l/min respectively). The high glucose response to maize could relate to its processing and physical form. The low insulin secretion could be due to inadequate stimulation by the 'entero-insular' axis. Moreover, variability in glucose insulin responses could stem from ethnic or genetic reasons. In the dietary management of black diabetics, refined maize should be replaced by other cereals.

Adult↗
PubMed1991

Reflux esophagitis therapy: sucralfate versus ranitidine in a double blind multicenter trial.

Sucralfate (Sc) suspension 6 g/day and ranitidine (Rn) tablets, 150 mg, were compared in 125 patients in a double-blind, multicenter, endoscopically controlled trial in the treatment of reflux esophagitis. Inclusion criteria were symptomatic reflux (number and severity of attacks) and endoscopic evidence of esophagitis (grades 1 to 4). Clinical assessments were performed on entry, and at 4 and at 8 weeks, and endoscopy was repeated at 8 weeks. Sc suspension and Rn placebo or Sc placebo and Rn tablets were taken on waking and immediately before retiring at night. Of the 125 patients, 27 were withdrawn because of default (Rn = 4; Sc = 14), noncompliance (Rn = 1; Sc = 2), or the development of congestive cardiac failure (Rn = 1), diarrhea (Rn = 1; Sc = 1), nausea (Sc = 1), constipation (Sc = 1), and hematemesis (Sc = 1). Analysis was performed on the remaining 98 patients, 43 of whom had been treated with Sc and 55 with Rn. Heartburn, acid regurgitation, epigastric pain, dysphagia, and chest pain were relieved in 34% vs 40%, 67% vs 72%, 71% vs 57%, and 86% vs 63% for Sc and Rn, respectively. There was no significant difference between the two groups. Endoscopic healing occurred in 47% of the Sc- and in 31% of the Rn-treated patients (chi 2 = 2.50), and healing or improvement was noted in 81% of the Sc- and 64% of the Rn-treated patients. This difference approached statistical significance (chi 2 = 3.73). There was no obvious endoscopic benefit in 8 of the 43 and 20 of the 55 patients in the groups treated with Sc and Rn, respectively. Although the findings with sucralfate and ranitidine in patients with reflux esophagitis completing the trial suggest a benefit of these agents, the absence of a placebo control group and the high default rates, particularly for those receiving sucralfate, preclude any firm conclusions as to relative or specific efficacy of these agents in this condition.

Administration, Oral↗
PubMed1991

Use of a stationary bed reactor and serum-free medium for the production of recombinant proteins in insect cells.

Insect cells (Spodoptera frugiperda) have been cultured in a stationary bed reactor, packed with a fibrous polyester carrier. When the bioreactor was perfused with serum-supplemented medium, a cell density of 6 x 10(6) cells ml-1 packed carrier was reached. Scanning electron microscopy investigations have shown that the insect cells grew along the three-dimensionally oriented fibers of the Fibra-cel carrier. After infection of the logarithmically growing cells with a recombinant baculovirus (Autographa californica) containing the gene coding for beta-galactosidase, the medium in the bioreactor was changed to serum-free medium. At day 13 postinfection (p.i.), a beta-galactosidase level of 320 microgram ml-1 and, at day 17 p.i., a virus titer of 2.1 x 10(8) TCID50 units ml-1 (day 17 p.i.) were reached. In another bioreactor, operated in a similar way but with serum-containing medium, a beta-galactosidase concentration of 360 microgram ml-1 and a virus titer of 2.3 x 10(8) TCID50 units ml-1 were obtained. These results indicate the potential use of this production system for the production of recombinant protein and baculovirus in insect cells.

Animals↗
PubMed1991

Limitations of faecal chymotrypsin as a screening test for chronic pancreatitis.

Faecal chymotrypsin was measured in patients with chronic pancreatitis and in healthy black urban and rural control subjects. In the patients, significantly lower values of faecal chymotrypsin were obtained (mean (SD) 2.4 1.79 U/g stool) whereas in urban control subjects, values were within the normal range (mean (SD) 13.2 (11.9)). In rural black control subjects, however, the faecal chymotrypsin value was significantly lower (mean (SD) 7.1 (5.1)) than in urban black control subjects. It is suggested that faecal pH may influence faecal chymotrypsin values. The mean faecal pH in rural black subjects (pH 6.14) was significantly lower than that in urban control subjects (pH 6.77) and in patients with chronic pancreatitis (pH 6.61). Moreover, mean faecal chymotrypsin is high (20.0 U/g stool) at a pH greater than 7. Between pH 6 and 7 the mean value drops to 8.6 U/g stool and below pH 6 mean faecal chymotrypsin is in the abnormal range (4.4 U/g stool). Hence, low values for faecal chymotrypsin may be due to lower faecal pH (less than 6) in healthy control subjects. For diagnostic purposes, the faecal pH value should be determined if a low faecal chymotrypsin value is obtained.

Adult↗
PubMed1990

Can premature luteinization in superovulation protocols be prevented by aspiration of an ill-timed leading follicle?

In 12 patients stimulated for in vitro fertilization and embryo transfer (IVF-ET), a single leading follicle developed, whereas the other follicles were 6 mm smaller. In 7 patients chosen at random (group A), the leading follicle was aspirated, whereas in the other 5 the leading follicle was allowed to continue growing (group B). Comparison of the hormonal pattern of both groups showed that a premature luteinizing hormone (LH) surge was avoided only in group A, and only in this group a second follicle aspiration for IVF-ET was done, and two pregnancies were achieved. In group B, aspiration for IVF-ET was canceled because of premature LH surge. It is suggested that aspiration of a single leading follicle during ovulation induction may be an efficient method to avoid premature LH surge enabling other follicles to develop up to the preovulatory stage.

Adult↗
PubMed1990

Pathological effects of pellagra on the esophagus.

This study determined the pathological effects of niacin/tryptophan deficiency on the esophagus. Nine patients with severe clinical pellagra and 31 age- and sex-matched controls were assessed. All pellagrins had an esophagitis varying from severe to mild. The esophagitis improved in five patients following six to seven days of vitamin therapy. The relationship between vitamin deficiencies and esophageal cancer is discussed.

Adult↗
PubMed1990

Alternative pathways for hydrogen disposal during fermentation in the human colon.

Hydrogen gas, which is produced during fermentation in the human colon, is either excreted in breath or metabolised by gut bacteria through a variety of pathways. These may include methanogenesis, dissimilatory sulphate reduction, and acetogenesis. To determine which of these routes predominates in the large intestine, stools were taken from 30 healthy subjects and incubated as 5% (w/v) slurries with Lintner's starch. In 23 of 30 subjects, methane production was the main method of hydrogen disposal. In the remaining seven, high rates of sulphate reduction were recorded together with raised production of H2S. All samples showed relatively low rates of hydrogen evolution and of acetate formation from CO2 and H2. Sulphate reduction and methanogenesis seem to be mutually exclusive in the colon and this is probably linked to sulphate availability. Sulphate reduction, methanogenesis, and acetogenesis were strongly influenced by pH. Sulphate reduction was optimal at alkaline pH values whereas methane production was maximal at a neutral pH and acetogenesis favoured acidic conditions. Faecal H2S values were related to carriage of sulphate reducing bacteria. These data show that a number of competing pathways for hydrogen disposal are possible in the large gut and that a variety of factors such as colonic pH and sulphate availability can determine which of these mechanisms predominates.

Acetates↗
PubMed1990

What causes appendicitis?

Appendicitis was rare in the past and still is in traditional Third World populations. It began to increase a century ago, peaked about 1950, and has now fallen to about half its previous incidence. As to causation, dietetically, it was contended that the increase was promoted primarily by an associated fall in dietary fiber intake. The recently advanced hygiene hypothesis considers the increase to have stemmed from improvements in hygiene, generally; these limited exposure to enteric infections and modified response to virus infections, thereby triggering appendicitis. Major uncertainties still prevail over the promotive and precipitating factors of the disease. It is doubtful whether individuals can take any action to avoid appendicitis.

Africa↗
PubMed1990

Protein-losing enteropathy in congestive cardiac failure: an entity of minor clinical significance.

Protein-losing enteropathology (PLE) occurs rarely in congestive cardiac failure (CCF). Using fecal alpha 1-antitrypsin, an endogenous marker of enteric protein loss, we studied 25 patients in severe CCF to determine the frequency, degree, and clinical significance of PLE. Excessive enteric protein loss was found in only two patients, confirming the relative infrequency of this condition. In addition, enteric protein loss did not appear to correlate with the serum albumin level; neither did it influence treatment or prognosis of the CCF. It is concluded that PLE associated with CCF is of minor clinical significance.

Biomarkers↗