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Biomedical subjects

I N Marks

Publications and source records attributed to I N Marks.

At least 109 records · Page 6Linked to original sources
PubMed1985

Vitamin A therapy in patients with Crohn's disease.

Vitamin A therapy has been claimed in isolated reports to be of benefit to patients with Crohn's disease. To investigate this further, 86 patients were entered into a long-term double-blind study of vitamin A, 50,000 U twice daily, as compared with placebo. After a mean of 14.1 mo of treatment there was no significant difference between the groups as measured by a variety of activity indices (including the National Cooperative Crohn's Disease Activity Index), the number of acute attacks, and the surgical rate. No toxic effects of vitamin A were observed during the study. In this study vitamin A has not been shown to be of benefit to patients with Crohn's disease who are in remission.

Adolescent↗
PubMed1985

Comparison of the oral (PABA) pancreatic function test, the secretin-pancreozymin test and endoscopic retrograde pancreatography in chronic alcohol induced pancreatitis.

The oral (PABA) pancreatic function test (PFT), the secretin-pancreozymin test and endoscopic retrograde pancreatography (ERCP) have been carried out in 32 patients with suspected chronic alcohol induced pancreatitis (CAIP) in order to evaluate which, if any, test was most likely to confirm the provisional diagnosis. Thirty one patients had changes of minimal (n = 6) moderate (n = 7) or advanced (n = 18) chronic pancreatitis on pancreatography, whilst one patient had a pancreas divisum. Eight hour urinary PABA excretion was significantly reduced in patients with moderate and advanced structural changes (p less than 0.001) and correlated significantly with all parameters of the PFT, although eight patients with an abnormal pancreatogram and pancreatic function test had a normal PABA value. The PFT was abnormal in 23 patients, but normal in five patients with an abnormal pancreatogram and low PABA value. Most patients with minimal change pancreatitis had a normal PABA test and PFT. We conclude that pancreatography appears to be the most sensitive method for detecting chronic pancreatic damage and for confirming a clinical diagnosis of chronic alcohol induced pancreatitis. Both the PFT and PABA test are useful confirmatory tests and whilst the PFT is slightly more sensitive for assessing pancreatic exocrine function, the PABA test is well tolerated and simple to perform. It may therefore be the complementary investigation of choice for this group of patients.

4-Aminobenzoic Acid↗
PubMed1985

Plasma cell infiltration of the small bowel: lack of evidence for a non-secretory form of alpha-heavy chain disease.

Eight patients with diffuse plasma cell infiltration of the small bowel who had the clinical features of immunoproliferative small intestinal disease (IPSID), but whose serum was negative for free alpha-heavy chains, were investigated for evidence of a non-secretory form of alpha-chain disease (alpha-CD). Molecular sieving and immunoblotting of serum, immunoperoxidase staining of biopsy specimens, and in vitro protein synthesis studies utilising an immunoprecipitation technique and polyacrylamide gel electrophoresis, failed to detect any new cases of alpha-CD. Four of the eight cases were found to have diffuse intestinal lymphoma. The remaining four patients, who were unsuccessfully investigated for evidence of a significant abnormality in cellular immunity, have not developed detectable alpha-CD protein or lymphoma over a mean of 143 months. Despite continuing exposure to possible environmental stimuli, it is concluded that not all cases of IPSID elaborate detectable alpha-CD protein or evolve to lymphoma.

Adolescent↗
PubMed1985

Plasma cell infiltration of the small intestine, recurrent pulmonary infections, and cellular immunodeficiency (Nezelof's syndrome).

An 18-year follow-up of a young woman who presented at the age of 10 years with a malabsorption syndrome and recurrent chest infections is reported. The serum immunoglobulins, and in particular the IgA, were increased, cell-mediated immunity was impaired but free alpha heavy chains were not detected. A jejunal biopsy showed plasma cell infiltration of the bowel with villous atrophy. Bronchiectasis, recurrent skin infections, and sinusitis were treated with frequent courses of antibiotics and corticosteroids. An initial presumptive diagnosis of cystic fibrosis was excluded by a normal sweat test. Although difficult to classify her exact type of immune deficiency state, the data would appear to conform to the syndrome of cellular immunodeficiency with normal or near normal immunoglobulins and lymphopenia (Nezelof's syndrome).

Adult↗
PubMed1984

Effect of mepyramine on the untoward side-effects of impromidine.

The value of impromidine, a potent histamine H2-receptor agonist, as an effective acid-secretory stimulant is limited by its tendency to cause cardiovascular side-effects. The possibility that the latter may be mediated not only by H2-receptors in the heart and peripheral blood vessels but also by overflow stimulation of H1-receptors was investigated in a double-blind study using impromidine with or without the H1-antagonist, mepyramine maleate. There was no significant difference between the two groups, suggesting that the side-effects are mediated by H2-receptors in the cardiovascular system alone.

Aminopyridines↗
PubMed1984

Recurrence of duodenal ulceration in patients on maintenance ranitidine.

Fifty-seven patients with recently healed duodenal ulcers were entered into a 1-year trial of maintenance therapy with ranitidine ( Zantac ; Glaxo) 150 mg at night to assess the safety and efficacy of the drug. Twenty-two of the patients were withdrawn because they violated the trial protocol. No serious side-effects were noted, but only 19 of the 35 patients who met the requirements of the study were free of endoscopic evidence of ulcer recurrence at the end of the trial period. The relapse rate of 46% in the present study was of the same order as those found in two previous South African studies of maintenance therapy with cimetidine given in a dose of 400 mg at night. These findings leave the question whether routine maintenance therapy is warranted in our patients unanswered.

Adult↗
PubMed1984

Are acid secretory tests of diagnostic value in patients with benign-looking gastric ulcers?

In 41 patients in whom endoscopy showed benign gastric ulcer, gastric secretory function was assessed before and after stimulation with pentagastrin (6 micrograms/kg); they were then followed up for a period of 2-4 years. Of these 41 patients, 37 had benign and the remaining 4 malignant ulcers. Of the 37 patients with benign gastric ulcers, 11 had basal achlorhydria but all secreted acid after pentagastrin stimulation. Seven of these 37 patients (19%) secreted less than 5 mmol/h in response to stimulation with pentagastrin. Of the 4 patients with malignant gastric ulcer, 3 had basal achlorhydria. After pentagastrin stimulation 3 of these patients (75%) secreted up to 5 mmol/h and 1 patient secreted 17 mmol/h. Biopsy evidence of malignancy was only obtained after repeat endoscopy and biopsy in 2 of these 4 patients. The present study confirms that a malignant ulcer may simulate a benign ulcer on endoscopy, and shows that the finding of hypochlorhydria in such patients warrants a cautious approach with repeat endoscopy and biopsy to exclude a malignant lesion.

Adult↗
PubMed1984

Conservative surgery in the Zollinger-Ellison syndrome.

Laparotomy failed to show an obvious primary lesion in two patients with the Zollinger-Ellison syndrome (ZES), one of whom had metastatic gastrinoma in a solitary lymph node which was removed. Both patients underwent a truncal vagotomy and pyloroplasty. Postoperative acid studies have shown a marked and sustained diminution in acid hypersecretion which was particularly striking in the patient with a solitary metastatic lymph node. The patient without a detectable lesion is now well-controlled on half the dose of cimetidine required pre-operatively and the other no longer requires therapy. We believe that patients in whom pre-operative investigations have shown no evidence of extensive metastases should undergo laparotomy in the hope of finding a solitary primary or isolated metastatic lesions unassociated with an obvious primary in the pancreas. Available evidence suggests that simple removal of such lesions offers the patient an excellent chance of long-term remission. However, if no such lesion is discovered, vagotomy may be the logical procedure to assist in the subsequent pharmacological control of the acid hypersecretory state.

Adult↗
PubMed1984

Structure and function in noncalcific pancreatitis.

A group of 47 carefully assessed patients with noncalcific pancreatitis was studied with ERCP and the secretin pancreozymin pancreatic function test (PFT). A simple scoring system was constructed for each of the PFT indices to create a PFT score for each patient and four grades of ERCP abnormality were documented, from minimal to gross. A simple pancreatic pain score was constructed to allow for the inclusion of patients with classical pancreatic pain in the absence of acute attacks associated with an elevated serum amylase. In general there was a correlation between the degree of structural change and functional impairment, with patients with the worst pancreatic function having the grossest ERCP changes. ERCP was abnormal in 45 of the 47 patients (96%) and the PFT in 34 of the 47 (72%). However, there were some marked discrepancies between the two methods, in particular two patients with normal function in the presence of gross structural changes. ERCP proved to be the more sensitive diagnostic technique than the PFT in this group of patients.

Adolescent↗
PubMed1983

Abdominal tuberculosis. A 10-year review.

Clinical experience with 125 patients with abdominal tuberculosis (46 of whom had intestinal tuberculosis, 8 mesenteric tuberculous lymphadenitis and 71 the peritoneal form) is presented. The diagnosis, especially in the intestinal cases, was seldom considered and a wide variety of conditions was simulated. Ileocaecal tuberculosis accounted for only 11 (24%) of the intestinal cases, while 17 patients (37%) had more distal involvement. A number of patients with diffuse colonic tuberculosis were seen. Chest radiographs showed that 51% of the 125 patients had active tuberculosis, but were completely normal in 38% of cases. Tuberculin skin testing was negative in 45% of cases. The pathogenesis, pathological features, diagnostic difficulties and complications are discussed, and the importance of considering the diagnosis is stressed.

Adolescent↗
PubMed1983

Inflammatory bowel disease in Cape Town, 1975-1980. Part I. Ulcerative colitis.

Previously documented and new patients with ulcerative colitis seen between 1975 and 1980 in the Gastro-intestinal Clinic of Groote Schuur Hospital were studied to establish the local incidence and clinical features of this disease. There were 220 patients and the mean follow-up was 7,7 +/- 0,4 years. Sixty per cent of patients were White, 37% Coloured and 3% Black. The incidence for the Coloured and White population was calculated to be 1,3 and 2,4/100 000 per year during 1970-1974 and 1,6 and 2,1/100 000 per year during 1975-1980, respectively. In Jews the rates were 8,5 and 10,4/100 000 per year for the two periods. Insufficient data are available to calculate an incidence for the Black population. The disease was limited to less than 15 cm above the anus in 14% of patients, to the rectosigmoid colon in 45%, and to the rest of the colon in 40%. Although the severity of symptoms was related to the extent of disease, 22% of patients with extensive colitis had mild symptoms, while 15% with disease limited to the rectum had severe symptoms. The clinical features were similar in the White and Coloured population groups. A total colectomy was performed on 20% of patients with extensive colitis; in 2% the disease was complicated by colonic carcinoma.

Adolescent↗
PubMed1983

Inflammatory bowel disease in Cape Town, 1975-1980. Part II. Crohn's disease.

Patients with Crohn's disease seen in the Gastro-intestinal Clinic of Groote Schuur Hospital between 1975 and 1980 were studied to establish the incidence and clinical features of this disease. There were 117 patients and the mean (+/- SEM) follow-up was 6,1 +/- 0,5 years. Of these patients 72% were White, 37% Coloured and 1% Black. The incidence for the Coloured and White population groups was calculated to be 0,4 and 0,9/100 000 per year during 1970-1974 and 1,3 and 1,2/100 000 per year during 1975-1980 respectively. In Jews the rates were 5,0 and 7,2/100 000 per year for the two periods. Insufficient data are available to calculate an incidence for the Black population. The disease involved the ileum in 39%, the colon in 17% and both areas in 44% of patients. At presentation 18% of patients had mild, 37% moderate, and 45% severe disease. The severity of symptoms was not related to the extent of the disease. A peri-anal fistula was present in 24% of patients. There was no difference in clinical features between the different population groups. Surgical resection had been performed in 50% of patients and 29% of these had had two or more resections. The surgical rate in the ileitis group was 63%, in the ileocolitis group 49% and in those with colitis 20%.

Adult↗
PubMed1983

Primary sclerosing cholangitis associated with inflammatory bowel disease in Cape Town, 1975 - 1981.

Patients with inflammatory bowel disease and serum alkaline phosphatase persistently raised to more than twice the normal level were investigated to assess the frequency of primary sclerosing cholangitis (PSC) in the Gastro-intestinal Clinic from 1975 to 1981. Twelve patients had a persistently raised alkaline phosphatase level of hepatic origin, 9 out of 250 with ulcerative colitis and 3 out of 164 with Crohn's disease. PSC was demonstrated in 8(3%) of the patients with ulcerative colitis, and carcinoma of the pancreas in the remaining 1. Three of the patients with PSC also had gallstones. The colitis antedated the biliary symptoms and signs in all but 1 patient. There was no correlation between the duration, extent and activity of the colitis and the development and outcome of the liver involvement. Investigations in the 3 patients with Crohn's disease revealed the presence of PSC in 2 (1,2%) and chronic active hepatitis in the 3rd. Of the 2 with PSC, one had cholelithiasis and has had recurrent episodes of cholangitis. The other has had only mild symptoms.

Adult↗
PubMed1983

Evaluation of an extended pancreatic function test in normal subjects and in patients with chronic pancreatitis.

Exocrine pancreatic response was evaluated in patients with varying degrees of pancreatic damage and in control subjects by means of an extended pancreatic function test (PFT). A second injection of secretin and pancreozymin was given after completion of the standard test. The discriminatory value of the standard PFT with regard to bicarbonate and enzyme output was not enhanced by a second bolus dose of hormones. It is concluded that the secretory potential of damaged pancreatic exocrine tissue cannot be exhausted by prolonged stimulation employing repeat bolus stimulation.

Adult↗
PubMed1983

The pharmacokinetics of ranitidine in patients with chronic duodenal ulceration: a comparison of responders and non-responders.

The pharmacokinetics of orally administered ranitidine were studied in 17 male patients with chronic duodenal ulceration. The patients were divided into 2 groups, 10 responders and 7 nonresponders, on the basis of their endoscopic response to ranitidine treatment. The 10 responders were studied both after a single 150 mg dose (SD) and after multiple dosing (MD) with ranitidine 150 mg twice daily for 4 weeks. The area under the curve (AUC) and maximum concentration (Cmax) were significantly higher (p less than 0.01 and p less than 0.05, respectively) after MD than after SD, but the half-life (t1/2) and minimum concentration (Cmin) 12 h postdosing did not differ. The non-responders were studied after MD only and their pharmacokinetic characteristics were compared with those of responders. No differences between the 2 groups were found. However, 2 non-responders had particularly low plasma ranitidine levels and high acid output. Such patients may need larger doses of ranitidine for adequate suppression of gastric acid. Five patients (4 responders and 1 non-responder) received ranitidine 20 mg i.v. The drug followed a two-compartment model, with mean values for t1/2 beta, volume of distribution steady-state and total plasma clearance of 80 min, 701 and 680 ml/min, respectively. The oral bioavailability of ranitidine in these 5 patients showed wide variation (27-76%; mean 51%).

Administration, Oral↗
PubMed1983

Pharmacokinetics of ranitidine in patients with chronic renal failure.

The pharmacokinetic behaviour of a single oral 150 mg ranitidine dose was studied in six patients with severe chronic renal failure (CRF) (creatinine clearance 2-18 ml/min) and compared to that in ten patients with duodenal ulceration but normal renal function (N) (creatinine clearance 69-125 ml/min). Although the maximum concentrations (Cmax) were significantly higher in CRF group when compared to N group (p less than 0.025) there was no difference in the time taken to reach Cmax (tmax). The area under the curve (AUC) was also significantly larger in the CRF group (p less than 0.001) than in the N group. Within the CRF group there was a large variation in Cmax (CV = 38%) and AUC (46%) which may reflect variable bioavailability of ranitidine. The terminal elimination rate constant (beta) was significantly smaller (p less than 0.001) in CRF group when compared with N group resulting in a median t1/2 for the CRF group of 7.3 h, 2.4 times that of N group. The recovery of unchanged ranitidine in the urine was significantly less in CRF group (p less than 0.001) despite a great interindividual variation in both groups. A significant linear relationship between beta and creatinine clearance was shown (r = 0.81 p less than 0.001). The results indicate that ranitidine elimination is appreciably reduced in renal failure. It is tentatively suggested that the standard 150 mg dose should be halved while keeping the dose interval unchanged at twelve hours in patients with severe renal failure (creatinine clearance less than 30 ml/min).

Adult↗
PubMed1983

Comparative study of pancreatic polypeptide (PP) secretion, endocrine and exocrine function, and structural damage in chronic alcohol induced pancreatitis (CAIP).

The serum pancreatic polypeptide response to intravenous Boots secretin (1.5 U/kg), glucose tolerance, and insulin responses have been studied in 25 patients with chronic alcohol induced pancreatitis of varying severity, and these results compared with a secretin-pancreozymin test, and the structural damage noted on pancreatography. For the pancreatic polypeptide response 16 healthy subjects acted as controls. There was a marked reduction in pancreatic polypeptide response in patients with advanced structural changes of chronic alcohol induced pancreatitis compared with patients with minimal/moderate changes (p less than 0.01) and with healthy controls (p less than 0.05) although there was no difference between the latter two groups. Similarly, while the ratio of peak to mean basal pancreatic polypeptide concentration was also significantly reduced in patients with advanced changes compared with healthy controls (p less than 0.05) there was a marked degree of overlap in patients with lesser degrees of structural damage and control subjects. For all patients with chronic alcohol induced pancreatitis, however, there was a significant correlation between the pancreatic polypeptide response and each parameter of the standard secretin-pancreozymin test and with glucose tolerance and the integrated insulin response. We conclude therefore that while the secretin stimulated pancreatic polypeptide response correlates significantly with accepted tests of pancreatic structure and function, there is a significant degree of overlap in the response obtained in patients who have minimal/moderate damage and healthy controls making the test insufficiently sensitive for routine diagnostic use.

Adult↗