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Biomedical subjects

R Abraham

Publications and source records attributed to R Abraham.

At least 91 records · Page 5Linked to original sources
PubMed1989

Modified diffusion blotting for rapid and efficient protein transfer with PhastSystem.

An easy-to-perform and efficient blotting method was developed for the transfer of proteins separated in PhastGel media. The method was evaluated by comparing the blotting results of low molecular weight marker proteins at different times. 14C-Labelled proteins were used for the assessment of the transfer efficiency. Highly efficient transfer was achieved within 1 h of blotting and the proteins were almost completely eluted from the gel in 2 h. The gel remained on its solid plastic backing, which is not the case when using an electrophoretic transfer method. As little as 1.25 ng of electrophoretically separated protein were enzymatically detected on the blot when applying blot-biotinylation. The transfer was performed at low temperature (4 degrees C), which-in contrast to thermoblotting-additionally offers the chance to blot thermolabile proteins. These superior features, together with the method's versatility and low cost, mark an interesting alternative to the previously recommended blotting procedures after PhastSystem electrophoresis.

Blotting, Western↗
PubMed1989

Antibodies to hepatitis B virus x-protein in sera of patients with acute and chronic active hepatitis.

Sera of patients with acute (AH) and chronic active hepatitis (CAH) were tested for anti-hepatitis B virus (HBV) x-protein (HBx) by immunoblotting, using recombinant MS2- and beta gal-HBx fusion proteins as substrate. Antibodies against HBx were detected in 5 out of 17 patients with AH at an early stage of infection, and in 13 out of 35 patients with CAH. Positive sera from AH patients showed a relatively weak anti-HBx reactivity when compared to sera from CAH patients. In follow up studies we tested serial serum samples from patients positive for anti-HBx. Patients with AH were observed for 3 to 6 weeks and CAH patients for up to 51 months. In general anti-HBx reactivities appeared to be stable although significant differences in apparent antibody levels were noted when sera from individual patients were compared. Our data further support an early expression of HBx-antigen in HBV-infected individuals. There was no correlation between HBe-antigen and anti-HBx in CAH.

Blotting, Western↗
PubMed1989

High arachidonic acid levels in the cord blood of infants of mothers on vegetarian diets.

1. Maternal and umbilical cord plasma samples were collected from forty-seven Asian women, twenty-eight life-long vegetarians and seventeen non-vegetarians, during delivery of their babies. The concentrations and fatty acid profiles of the plasma free fatty acid and triacylglycerol fractions were determined. 2. There were no significant differences between the levels of free fatty acid and triacylglycerol in either maternal or cord plasma from vegetarian compared with non-vegetarian Asian women. The fatty acid profiles of the lipid fractions in the two groups were similar. Total plasma free fatty acid levels in the maternal circulation correlated with umbilical cord levels. 3. The levels of linoleic acid in the maternal plasma free fatty acid fraction of the Asian women were much higher than previous reports on mixed populations of European women. In the Asian women arachidonic acid concentrations in both maternal and umbilical circulations were over four times higher than those reported for women unselected for race and diet.

Adult↗
PubMed1989

Coronary artery vasculitis and myocardial infarction associated with antiphospholipid antibodies in a pregnant woman.

A 28-year-old, 16 week primigravida presented with an acute anteroseptal myocardial infarction and a past history of recurrent venous thromboembolism and primary infertility. Although she lacked other clinical features of systemic lupus erythematosus, she had a circulating 'lupus' anticoagulant, anticardiolipin antibodies, a weakly positive anti-nuclear antibody and thrombocytopenia. She died suddenly despite corticosteroid therapy and autopsy revealed coronary arteritis and thrombosis.

Adult↗
PubMed1989

A comparison of two methods for measuring thermal thresholds in diabetic neuropathy.

Thermal thresholds can be measured psychophysically using either the method of limits or a forced-choice method. We have compared the two methods in 367 diabetic patients, 128 with symptomatic neuropathy. The Sensortek method was chosen for the forced-choice device, the Somedic modification of the Marstock method for a method of limits. Cooling and heat pain thresholds were also measured using the Marstock method. Somedic thermal thresholds increase with age in normal subjects, but not to a clinically significant degree. In diabetics Marstock warm threshold increased by 0.8 degrees C/decade, Sensortek by 0.1 degrees C/decade. Both methods had a high coefficient of variation in normal subjects (Sensortek 29%, Marstock warm 14%, cool 42%). The prevalence of abnormal thresholds was similar for both methods (28-32%), though Marstock heat pain thresholds were less frequently abnormal (18%). Only 15-18% of patients had abnormal results in both tests. Sensortek thresholds were significantly lower on repeat testing, and all thresholds were higher in symptomatic patients. Both methods are suitable for clinical thermal testing, though the method of limits is quicker. In screening studies the choice of a suitable apparatus need not be determined by the psychophysical basis of the test.

Adolescent↗
PubMed1988

An increase in intracellular free Ca2+ associated with serum-free growth stimulation of Swiss 3T3 fibroblasts by epidermal growth factor in the presence of bradykinin.

Bradykinin gave a biphasic increase in intracellular free Ca2+ concentration ([Ca2+]i) in serum-deprived Swiss 3T3 fibroblasts loaded with the photoprotein aequorin. Epidermal growth factor (EGF) alone did not increase [Ca2+]i, but when added after bradykinin there was an increase in [Ca2+]i. The EGF-dependent increase in [Ca2+]i was maximal at 3 min and disappeared with a half-life of 6 min after bradykinin. Removing Ca2+ from the external medium did not abolish either the bradykinin or the EGF-induced [Ca2+]i responses. Although prostaglandins E2 and F2 alpha also gave [Ca2+]i responses and permitted an EGF-dependent [Ca2+]i response, the effect of bradykinin did not appear to be mediated by prostaglandins since it was not blocked by indomethacin. Vasopressin and phorbol 12-myristate 13-acetate both gave a [Ca2+]i response but did not facilitate a [Ca2+]i response by EGF. Bradykinin or EGF alone did not increase DNA synthesis in growth-arrested Swiss 3T3 fibroblasts, but EGF added together with, or after, bradykinin increased DNA synthesis. The effect disappeared with a half-life of 180 min after the addition of bradykinin. It is concluded that stimulation of receptor protein tyrosine kinase is unlikely, by itself, to explain the increase in DNA synthesis produced by EGF. The observed increase in [Ca2+]i caused by EGF after bradykinin probably reflects the interaction of intracellular second messenger pathways leading to facilitation of DNA synthesis.

Aequorin↗
PubMed1988

Assessment of trace metal intake and status in a Gujerati pregnant Asian population and their influence on the outcome of pregnancy.

Dietary assessments and biochemical indices including plasma zinc and copper were determined in pregnant vegetarian and non-vegetarian Gujerati women in India at 28 weeks gestation, and the results were contrasted with those of a comparable group of Gujerati pregnant women living in Harrow. Even though the dietary intake of energy, protein and zinc was significantly lower in the Indian vegetarian Gujerati group when compared to the equivalent group in Harrow, the birthweights of the babies delivered at term were similar. The intake of zinc in the diet of the Gujerati Indian vegetarian and non-vegetarian groups was only one quarter of the US recommended intake during pregnancy and was approximately one half in the Harrow Indian groups. Even so, the plasma concentrations of zinc were similar in all dietary groups in either India or Harrow. The albumin content in the plasma of both the Gujerati Indian vegetarian and non-vegetarian was significantly reduced when compared to the equivalent Harrow dietary groups. The plasma concentrations of both calcium and sodium were significantly correlated with the albumin concentration but not with the plasma content of zinc. Copper levels were elevated to the normal range in both dietary groups of the Gujerati and were similar to the concentrations found in the Harrow groups.

Birth Weight↗
PubMed1987

Left ventricular full-thickness cardiomyoplasty with pericardial neoendocardium: experimental development of a surgical procedure.

Cardiomyoplasty, a surgical procedure using stimulated skeletal muscle graft to replace or repair damaged myocardium, has been successfully performed in experimental animals and clinical patients. Whenever feasible, endocardium of the damaged myocardial segment is retained and partial-thickness cardiomyoplasty should be carried out. However, if this procedure were to be applied to enlarge a hypoplastic ventricle or to maintain normal dimensions of the ventricular cavity in some repairs in adults, full-thickness replacement of the ventricular wall with contractile skeletal muscle mass would be required. To develop such a technique, several canine experiments were carried out. In 7 dogs, "simple full-thickness cardiomyoplasty" was performed by using a latissimus dorsi muscle graft to repair a full-thickness left ventricular wall defect. We found it was difficult to obtain adequate hemostasis between the nonscarred myocardial tissue and the skeletal muscle graft, and excessive suturing to obtain hemostasis resulted in strangulation of the muscle grafts. The skeletal muscle-blood interface in the left ventricle was found to be highly thrombogenic. The perioperative hemorrhage and the risk of muscle graft strangulation by excessive sutures were avoided by using a pericardial patch as neoendocardium in 5 dogs that underwent similar full-thickness cardiomyoplasty procedures. Although the pericardial neoendocardium was not fully antithrombogenic in this canine model, endothelialization of the endocardium occurred within several weeks after operation. Thus, when combined with an implantable synchronized burst stimulator, this technique may in the future provide an effective "full-thickness dynamic cardiomyoplasty" to enlarge the ventricles and augment myocardial function in select patients.

Animals↗
PubMed1987

Diets of Asian pregnant women in Harrow: iron and vitamins.

In a study of the Asian pregnancy, the dietary intakes of 813 Asians and 54 Europeans living in Harrow were compared. Results of calculation of intakes of iron and vitamins are presented in this paper. The key findings were that vitamins D and B12 intakes were markedly lower amongst the Asians, particularly the Hindu vegetarians. Asians had lower intakes of other vitamins but these levels are unlikely to lead to deficiency and therefore not relevant in clinical terms. The Hindu vegetarians can be regarded as a fairly homogenous group with differences occurring within the group only in vitamin B12 intake. From the nutritional data it appears unnecessary to advocate any change in the Gujarati diet other than supplementation with vitamin D.

Asia↗
PubMed1986

Rapid induction of forestomach tumors in partially hepatectomized Wistar rats given butylated hydroxyanisole.

Rats subjected to two-thirds partial hepatectomy (PH) and given the antioxidant butylated hydroxyanisole (BHA) at a dietary concentration of 2% for 3 months developed forestomach lesions. Histologically, these lesions were classified as hyperplasia, dysplasia of the basal cell, papillomas, and carcinomas in situ. In intact rats forestomach carcinomas were seen by other investigators after feeding 2% BHA for 15-20 months. Histochemical studies of tumors revealed a marked increase in the phenotypic expression of the oncofetal enzyme, gamma-glutamyl transpeptidase (GGT) in the tumors of treated rats.

Animals↗
PubMed1986

In vitro effects of cadmium chloride on preimplantation rat embryos.

Preimplantation rat embryos (8-cell, morulae, blastocysts) were incubated for 24 hr in vitro in a Brinster medium with or without cadmium chloride (1 microgram/ml). CdCl2 arrested the development of both the 8-cell and morulae into blastocysts. Morphologic observations revealed the 8-cell embryo to have shrunken cells and pyknotic nuclei. Morulae appeared smaller in size with fewer cells than comparable controls. CdCl2 was clearly cytotoxic to the early blastocysts, inner mass cells were most damaged with cell death, pyknosis, and accumulation of debris.

Animals↗
PubMed1986

[Aicardi's syndrome. Report of 2 cases].

Aicardi's syndrome is a clinical entity characterized by agenesis of the corpus callosum, severe mental subnormality, seizures (most frequently spasms in flexion), characteristic electroencephalographic changes (burst-suppression pattern), typical chorioretinal lacunae, present only in females. Other associated findings are rib and vertebral dysplasias; frequently found are cortical heterotopias. This syndrome is of hereditary origin, now considered a probable X-linked dominant trait with male lethality. The authors describe two cases of this syndrome with the full clinical picture.

Agenesis of Corpus Callosum↗
PubMed1985

Chronic and subchronic effects of various forms of carrageenan in rats.

The subchronic and chronic toxicity of undegraded (native) carrageenan with respect to botanical source, and type of polymer chain (kappa, lambda, and iota) was investigated in rats for 13 to 39 weeks. The carrageenans were incorporated in the diet at 1 or 5% w/w. In all instances comparable levels of Alphacel were used. In the study designed to determine if there were any differences between various strains of rat, the Osborne-Mendel rat was used in addition to the Sprague-Dawley strain. Only the Sprague-Dawley strain was used in the other studies. Parameters utilized for detecting toxicity included mortality, body weights, fecal occult blood, hematologic indices, clinical chemistry, gross and microscopic histology, and evidence of carrageenan storage. Except for minor changes, no evidence was obtained for any direct effect of the carrageenans on the liver or the gastrointestinal tract.

Animals↗
PubMed1985

Uptake and disposition of mirex in hepatocytes and subcellular fractions in CD1 mouse liver.

In vivo uptake and disposition of [14C]mirex by CD1 mouse liver subcellular fractions and cells of different nuclear ploidy were examined following single or multiple doses of mirex injected intraperitoneally. Significant amounts of mirex were rapidly taken up by liver (21-29%), suggesting that liver is one of the primary sites of accumulation of the chemical. Among subcellular fractions, mirex was predominantly distributed in mitochondria and microsomes in the irreversibly bound form (about 20%), although its levels fluctuated considerably with time. Mirex was completely dissociated with trichloroacetic acid treatment from both nuclear and plasma membrane fractions, although the total uptake by these fractions was markedly high. The time course of uptake and concentration-dependent disposition of mirex revealed that polyploid hepatocytes selectively accumulated higher amounts of the chemical (two to three times) compared to diploid hepatocytes. The increased affinity of polyploid cells to mirex may indicate a greater susceptibility of this cell type to the chemical insult and also may suggest a possible early involvement of polyploids in the tumorigenic process in rodent livers.

Animals↗