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Biomedical subjects

A Das

Publications and source records attributed to A Das.

At least 361 records · Page 20Linked to original sources
PubMed1987

Detrimental actions of endogenous fatty acids and their derivatives. A study of ischaemic mitochondrial injury.

Functional and structural alterations of myocardial mitochondria were investigated after four conditions of myocardial ischaemia in guinea pig heart: (1) 45 min complete ischaemia, (2) 60 min low-flow anoxic perfusion (0.3 ml/g wet weight per minute) with a modified Tyrode solution, (3) as (2) with 0.4 mM palmitic acid added to the perfusate, and (4) as (2) with 0.4 mM oleic acid added. Under conditions (1) and (2) the loss of tissue ATP (20-30% of aerobic control) and the degree of mitochondrial injury were similar. But when fatty acids were present during low-flow anoxia, ATP loss and mitochondrial injury were more severe. Oleic acid caused greater injury than palmitic acid. The extent of mitochondrial injury corresponded to variations in mitochondrial long-chain acyl CoA content. Compared to aerobic control values, acyl CoA was increased 1.5 fold under condition (1), not significantly altered under condition (2), increased 3.2 fold under condition (3) and increased 4.3 fold under condition (4). In low-flow anoxia fatty acids enhanced the depression of oxidative phosphorylation, the loss of cytochromes, the inhibition of adenine nucleotide translocase and the reduction of mitochondrial Ca2+ sequestration. Fatty acid induced injury differed in quality from that of conditions (1) and (2): complex II dependent respiration was markedly affected, cytochrome b was lost extensively, and cytochrome oxidase activity was distinctly reduced. The results indicate that fatty acids, when administered to ischaemic myocardium, interfere with mitochondrial membranes at several sites, probably by their CoA esters. The more lipophilic oleyl moiety has a greater effect than the palmityl moiety.

Acyl Coenzyme A↗
PubMed1987

Linear IgA bullous dermatosis of adults and children: an immunoelectron microscopic study.

The ultrastructural localization of the IgA deposits in the skin of 15 patients with linear IgA bullous dermatosis of adults (LAD), 13 with chronic bullous dermatosis of childhood (CBDC) and three with childhood cicatricial pemphigoid (CCP) were studied. The site of the antigen was determined using sera from two LAD, 13 CBDC and two CCP patients. In all 31 patients the IgA was located predominantly below the lamina lucida (sublamina densa). Similarly, the indirect immunoelectron microscopic studies demonstrated the antigen to be present at the same site, below the lamina densa. This suggests that in linear IgA bullous dermatosis the antibody reacts with the antigen in the sublamina densa region of the basement membrane zone.

Adolescent↗
PubMed1987

Demonstration of insulin-specific mRNA in cultured rat retinal glial cells.

A number of studies have recently demonstrated that insulin may be synthesized outside the pancreas. The present study was designed to investigate whether insulin-like activity exists in retinal glial cells and if so, whether it is due to local synthesis of insulin. Immunocytochemical techniques using insulin antisera were applied to cultured rat retinal glial cells, and insulin-like immunoreactivity was demonstrated in the cytoplasm of these cells. In situ DNA-RNA hybridization studies using 3H-labeled rat insulin cDNA indicated that the glial cells, particularly the Müller cells of the retina also contained the mRNA necessary for de novo synthesis of insulin or a closely homologous peptide. This peptide may be important in neuromodulation or regulation of metabolism of retinal cells and capillaries.

Animals↗
PubMed1986

Insulin-like immunoreactivity in human retinoblastoma Y79 cell line.

Cells from the Y79 human retinoblastoma cell line were examined by immunofluorescence immunocytochemistry using an antiserum against insulin. All the cells showed intense staining, indicating the presence of insulin-like immunoreactivity in these cells. Our observations suggest that insulin may play an important role in the metabolism of retinoblastoma cells and that it may be possible to use this cell line as an in vitro model for studies on the action of insulin in the metabolism of human retinal cells.

Cell Line↗
PubMed1986

Promoters of Agrobacterium tumefaciens Ti-plasmid virulence genes.

The DNA sequences of the promoter and 5' upstream regions of six Agrobacterium tumefaciens Ti-plasmid encoded virulence (vir) genes were determined. The transcription initiation sites were mapped by the S1 nuclease protection assay. In the -10 region, the vir promoters share a consensus sequence that is homologous to a DNA sequence found in the same region of E. coli promoters. In contrast, the -35 region sequences are variable. Several vir genes contain two common hexanucleotide sequences, 5'CGAGTA3' and 5'GCAATT3'. Translation initiation codons for all vir genes, except virG, are preceded by sequences homologous to the ribosome binding site sequences found in E. coli.

Base Sequence↗
PubMed1986

Pleurodesis in metastatic pneumothorax.

A 57-year-old woman with bilateral pneumothoraces secondary to pulmonary metastases from leiomyosarcoma of the uterus was treated successfully by intrapleural instillation of tetracycline.

Female↗
PubMed1985

Glucagon-like immunoreactivity in mouse and rat retina.

Mouse and rat retinae were examined by the peroxidase-anti-peroxidase technique of immunocytochemistry using an antiserum against glucagon. The immunoreactivity was found in the cells of the ganglion cell layer and inner nuclear layer, including Müller cells. These observations may indicate that glucagon or a similar peptide is important in neuromodulation and/or metabolism of retinal cells.

Animals↗