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Biomedical subjects

R Assan

Publications and source records attributed to R Assan.

At least 271 records · Page 15Linked to original sources
PubMedDate not supplied

Probability of remission in individual in early adult insulin dependent diabetic patients. Results from the Cyclosporine Diabetes French Study Group.

The aim of this study was to determine which candidates were suitable for immunotherapy among adult insulin dependent diabetic patients of recent onset. A statistical analysis was performed using the results of a multicentre randomized trial of cyclosporine versus placebo after nine months of treatment. When the baseline characteristics of the patients in remission were compared with those not in remission, there was no difference observed either in initial residual beta-cell function (glucagon stimulated C-peptide level), or in immunological markers (T4 and T8 lymphocytes counts, Interleukin 2). The parameters showing the most difference were, in addition to treatment group, the duration of diabetes symptoms and body mass index at inclusion, and the HLA-DR phenotype. This was confirmed using a logistic regression analysis, in which these variables were found to be significantly related to remission. The probability of remission in each individual patient was then calculated using these variables in the mathematical function provided by the logistic model. Ninety eight out of 110 patients were correctly classified using this method. In addition, it must be noted that only subjects adequately treated by cyclosporine were still in complete remission after a one year follow-up. Conversely, it appeared that immunosuppression in subjects having a predicted probability of remission lower than 0.35 using the mathematical function, and being non-DR3, non-DR4 has to be avoided. These results will be useful in optimizing the recruitment of patients in on-going or future trials of immunotherapy in early diabetes.

Adolescent↗
PubMedDate not supplied

Reproducible high yields of rat islets of Langerhans.

Isolation of islets of Langerhans from the pancreas by action of collagenase, a major breakthrough for physiological studies in vitro, has long appeared empirical, and the results were sometimes unpredictable. Isolation yields (number of islets obtained per pancreas) and their reproducibility, purification from exocrine remnants and vitality of the islets obtained, can improve owing to precise techniques, adapted to the architecture of collagen in the pancreas. We have tested four isolation-purification techniques in the rat pancreas. The best results were obtained by combining intra-ductal collagenase injection, with complete but moderate distension of the gland, avoiding leakage, multistep digestion (in situ and then in vitro), followed by purification on a discontinuous bovine serum albumin (BSA) gradient. Average yields were 670 +/- 40 islets per pancreas (range 570-800), versus 170 +/- 9 (range 40-350) with the technique used initially. The use of BSA discontinuous gradient improved the purification yield: 90-96% of islets obtained were concentrated in the 26/29% BSA interface. Furthermore, this technique shortened the duration of purification step: 1 hr (centrifugation gradient) vs 3 hrs (handpicked). It was verified that islets were morphologically free of exocrine tissue. Islet structure was well preserved either in conventional histology or insulin and glucagon immunoperoxidase staining. Islet vitality, as assessed by trypan blue exclusion test, was 100% of freshly isolated islets, and 89% after 24 hrs culture. Insulin secretory responses to a given stimulus were stronger than in the case of islets isolated by former techniques: 10-12 times the basal release (vs 5 times) with clear dose-response proportionality.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Overwhelming strongyloidiasis in a diabetic patient following ACTH treatment and keto-acidosis.

A non insulin-dependent Zairian patient developed ketoacidosis and then overwhelming strongyloidiasis following ACTH treatment. Severe cardiovascular and respiratory failure, associated with severe acute hypoprotidemia, preceded death, which occurred within three days. Pathologic examination revealed a massive parasitic infiltration of the gastro-enteric mucosa, mesenteric lymph nodes, and the pulmonary tissue and vessels. We suggest that ACTH treatment and keto-acidosis induced immune deficiency and triggered the acute parasitic episode, in a patient originating from an endemic area. Badly controlled diabetes should be known as a risk factor of hyperinfection by Strongyloides stercoralis in latent carriers.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

[Diabetogenic tropical pancreatitis].

The tropical calcifying pancreatitis and/or fibrous pancreatitis are responsible for a number of cases of juvenile insulin-dependent diabetes in the Third World countries. World wide distributed in the tropical areas of Asia, Africa and South America, they can also be observed in Europe, in migrants from these countries. Intensive epidemiological and biochemical studies are currently developed in order to shed light on the many obscure points. Classification of the typical calcifying pancreatitis and the related syndromes is a matter of debate. The pathological basis is calcification of the pancreas and echography of the gland may become a cheap convenient relatively specific tool for epidemiology. The clinical syndrome consists of chronic painful pancreatic episodes since childhood, associated with pancreatic exocrine insufficiency, followed by the onset, during adolescence, of diabetes mellitus, which is most of the times insulin dependent. Patients' history is free of chronic alcoholism, but includes constantly chronic caloric and proteic malnutrition. Although insulin dependent this diabetes in not prone to ketosis, due presumably to carnitine deficiency and relative glucagon deficiency (or suppressibility). Insulin resistance is traditionally noted, the pathophysiology of which is unknown. The mechanism of calcification appearance is also undetermined. Either a deficiency in pancreatic stone protein, or the toxic effect of cyanogen glucosides present in cassava and other tropical foodstuffs, or the malnutrition-related deficiency in sulphur-containing aminoacids may be causal factors. No valid experimental model of the disease is available.

Calcinosis↗
PubMedDate not supplied

[Adult celiac disease and type 1 diabetes: a severe and sometimes unknown genetic association].

In 6 type 1 (insulin-dependent) diabetics, treated with insulin since the age of 2 to 35 years (mean 12), coeliac disease was diagnosed between the 10 th and 73 th years of age (mean 26). Five were of North African origin. Digestive symptoms and severe malnutrition were present in all of them, associated, in the two younger, with a major growth retardation and, in one, multiple pathologic fractures. Biopsy of the small intestine demonstrated, in all, total or subtotal villous atrophy. The metabolic control of diabetes was poor, with frequent hypoglycaemic attacks, induced by minute insulin doses. Severe chronic complications of diabetes were detectable in all of them. Plasma anti-reticulin antibodies were present, at high titer before starting the gluten-free diet, declining slowly after starting this diet, and negative in the patients who followed this diet. Among the genetic markers (which were determined in 4), HLA A1 was present in 4, B8 and DR3 in 3 and DR4 in 3. The DR7 was not detected. The gluten-free diet, memorized by the patients by the use of simple rules, improved the digestive symptoms, and insulin doses could then be increased. The overall prognosis remained poor, due to diabetic complications and sociologic desinsertion. Coeliac disease occurs in 1 to 2% of type 1 diabetics and 4-6% of the coeliac patients are diabetics. Diabetic subjects from North Africa are at high risk of this association. Misdiagnosis of the coeliac disease compromises the metabolic control and nutritional state.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗