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Biomedical subjects

M Singh

Publications and source records attributed to M Singh.

At least 1,063 records · Page 59Linked to original sources
PubMed1983

Studies on the effects of total nephrectomy in sheep.

Effects of total nephrectomy were studied in six sheep. There was no marked deterioration in the clinical condition of the animals except anorexia and reduced water intake. Three sheep survived the period of observation of 120 hours when they were euthanized. One animal suddenly died at each of 76, 80 and 100 hours. Progressive increase of blood urea nitrogen concentration was accompanied by severe metabolic acidosis in the later stages. Plasma creatinine rose significantly but the change was not marked. Plasma inorganic phosphorous and calcium decreased significantly. Unaffected plasma sodium levels were accompanied by hyperkalemia and hypochloremia. Plasma total proteins and albumin decreased significantly in the later stages. Results showed markedly different responses to total nephrectomy in sheep as compared to changes reported in cattle and nonruminants.

Acidosis↗
PubMed1982

Rapid synthesis of oligodeoxyribonucleotides. VII. Solid phase synthesis of oligodeoxyribonucleotides by a continuous flow phosphotriester method on a kieselguhr-polyamide support.

A new kieselguhr-polydimethylacrylamide support has been used in a continuous flow, column system for solid phase synthesis of oligodeoxyribonucleotides by a phosphotriester procedure. Using only protected mononucleotides a 14-mer, 20-mer and 27-mer were assembled in high repetitive yield using a simple manually operated, bench top apparatus.

Acrylamides↗
PubMed1982

The location of the first AUG codons in cowpea mosaic virus RNAs.

We have made use of the known sequence of the 5' ends of both CPMV RNAs to synthesise an oligodeoxynucleotide which can prime second-strand DNA synthesis on full-length cDNA copies of both RNAs. By priming synthesis in the presence of dideoxynucleoside triphosphates, we have determined the positions of the first AUG codons in each RNA. These occur at positions 115 and 207 on M and B RNA respectively. By using a cloned double-stranded DNA fragment derived from near the 5' end of M RNA as a primer additional sequence from the 5' terminal region of M RNA has been obtained.

Base Sequence↗
PubMed1982

Effect of different extenders on glutamic oxalacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) release from frozen buffalo semen.

Sixty buffalo semen samples (motility greater than 60%) were frozen in 3 extenders, viz., Tris yolk glycerol (TY-G), Citric acid whey glycerol (CAW-G) and Egg yolk glucose sodium bicarbonate glycerol (EYGSB-G) for studying the release of GOT and GPT enzymes in the extracellular fluid during pre-freezing (after first extension) and post-freezing (15 minutes and 30 days after freezing). Release of GOT and GPT enzymes was less in TY-G than CAW-G and EYGSB-G extenders. Significant differences (P<0.01) in GOT and GPT release were observed between extenders and bulls at various stages of freezing of semen.

Journal Article↗
PubMed1982

Progesterone profile in buffaloes during various stages of oestrous cycle using radioimmunoassy technique.

Investigation were carried out to study the norms of progesterone concentration in the blood serum of buffaloes during various phases of oestrous cycle. Twenty four animals (12 heifers and 12 cows) were used. The blood serum samples were stored at -20 degrees C until processed for progesterone assay. The progesterone concentrations were measured by the radioimmunoassay technique. The progesterone levels were 0.360 +/- 0.062 and 0.334 +/- 0.066 ng/ml on the day of oestrus in buffalo-heifers and buffalo-cows, respectively. The values were around 1 ng/ml till day 6, followed by a gradual increase to a peak average value of 4.888 +/- 0.399 and 5.119 +/- 0.415 ng/ml on day 15 of the cycle in heifers and cows, respectively. Thereafter, the progesterone concentration fell abruptly to a level similar to that at oestrus. The mean progesterone value a day before oestrus was 0.488 +/- 0.067 and 0.577 +/- 0.053 ng/ml in buffalo-heifers and buffalo-cows, respectively. The mean progesterone concentration of different days of the cycle (except day 16) did not differ significantly (P / -0.01) between heifers and cows.

Journal Article↗
PubMed1982

Adenyl cyclase activity following fluoride ingestion.

Adenyl cyclase activity and fluoride content were investigated in various tissues of adult rabbits given NaF (10 mg/kg body wt./day) orally for 6 months. The activity of adenyl cyclase increased significantly in bone, liver, and kidney, whereas it was unchanged in skeletal muscle following fluoride ingestion. The levels of fluoride were elevated in serum and all the tissues investigated following fluoride ingestion; bone revealed the highest percentage increase and skeletal muscle the lowest.

Adenylyl Cyclases↗
PubMed1982

Melanization and encapsulation in Aedes aegypti and Aedes togoi in response to parasitization by a filarioid nematode (Breinlia booliati).

In Aedes aegypti (Singapore strain), s refractory host, there was a marked progressive decline of developing larvae of Breinlia booliati during the incubation period. However, in Aedes togoi, a susceptible host, the filarial larvae developed normally and the number of larvae remained constant throughout the incubation period. Encapsulation and melanization of B. booliati larvae in Ae. aegypti and Ae. togoi were studied. Ae. togoi occasionally mounted a defence reaction to the infection. In Ae. aegypti, various stages of filarial larvae were frequently affected by the defence mechanisms of the host, and a relatively large number of melanized larvae were recovered in dissections throughout the incubation period. The process of melanization is described and the relationship between melanization and haemocytes of mosquitoes is discussed. Haemocytes of the mosquito host appeared to be involved in the encapsulation of filarial larvae, as evidenced by adherence of cells to the cuticle of the larvae and the formation of a translucent, gelatinous envelope which contained intact cells, necrotic cells, spaces and numerous whitish granules. The possible involvement of a humoral reaction in bringing about the degeneration and retardation of the filarial larvae is discussed.

Aedes↗
PubMed1982

Effect of thiamin deficiency on pancreatic acinar cell function.

The aim of the present study was to determine the effect of thiamin deficiency on pancreatic acinar cell function. Weight-matched triplets of Sprague-Dawley rats were fed a purified thiamin-deficient diet ad libitum, isocaloric amount of purified thiamin-sufficient diet or rat feed ad libitum for a mean of 33 (+/- 0.5 SEM) days. Effect of diets on body weight, pancreas weight, DNA, RNA, protein and amylase content, synthesis of protein and secretion were determined. Controls diet effect was considered when fed ad libitum controls were different from isocaloric controls. Thiamin effect was considered when thiamin-deficient diet treatment resulted in effects similar to control diet effects in addition to specific effects that included reduced body weight, total protein, and amylase. Basal and bethanechol (10-4 M) stimulated secretion of protein and amylase were increased. It is concluded from this study that thiamin deficiency per se induced a reduction in body weight, pancreatic protein and digestive enzyme content and increased protein and digestive enzyme secretion due to metabolic derangements leading probably to altered redox state of pancreatic acinar cell.

Amylases↗
PubMed1982

Kinetics and characterization of the proteins synthesized during infection by bacteriophage PM2.

Using two-dimensional gel electrophoresis, we have examined the proteins whose synthesis is stimulated in Alteromonas espejiana by infection with the membrane-containing bacteriophage PM2. In addition to four virus structural proteins, 11 non-structural proteins have been resolved and identified by their apparent isoelectric points and molecular weights. The relative rate of synthesis of each of the proteins was determined during the course of infection. Synthesis of the earliest proteins began around 10 min after infection. Synthesis of the virus structural proteins as a group did not begin until about 25 min after infection. In contrast to these structural proteins, the rate of synthesis of most of the non-structural virus proteins began to decline between 30 and 35 min after infection. This time preceded the onset of cell lysis marked by ion leakage (47 min); it corresponded to the beginning of packaging of virus DNA, removing that DNA from replication and transcription. Protein processing could not be demonstrated by pulse-chase labelling. These 15 proteins account for all of the coding capacity of the virus DNA. The virus origin of 14 of these proteins was established in an in vitro transcription-translation system programmed by PM2 DNA.

Bacteriophages↗
PubMed1982

Role of cyclic adenosine monophosphate in amylase release from dissociated rat pancreatic acini.

1. The effect of octapeptide of cholecystokinin-pancreozymin (CCK(8)), bethanechol, cholera toxin, glucagon and vasoactive intestinal polypeptide (VIP) on amylase secretion and lactic dehydrogenase (LDH) release from isolated rat pancreatic acini was studied.2. In isolated rat pancreatic acini, in the absence of theophylline in the medium, amylase secretion was increased by 65-78% with 10(-7) and 10(-6) M-cholera toxin. In the presence of theophylline, amylase secretion was increased by 43-56% with 10(-7) and 10(-6) M-cholera toxin following a 90 min incubation. No effect was observed in the presence of theophylline at 30 and 60 min. The effect of cholera toxin was potentiated by CCK(8) at 60 and 90 min.3. In the absence of theophylline in the medium, amylase secretion was increased by 81-118% with 10(-5) and 10(-4) M-glucagon and 86% with 10(-6) M-VIP at 60 min. In the presence of theophylline in the medium, amylase secretion was increased by 53-246% with 10(-9) to 10(-6) M-glucagon and 111-158% with 10(-7) and 10(-6) M-VIP respectively. The effect of glucagon and VIP was potentiated by CCK(8).4. Potentiation of the rate of amylase release due to glucagon (10(-5) M) and VIP (10(-6) M) occurred during the first 15 min of incubation.5. Release of LDH was not increased by any of these agents.6. It is concluded that cyclic AMP rise (due to cholera toxin, glucagon and VIP effect) increased amylase secretion from rat pancreatic acinar cells. This effect is less marked than in the guinea-pig pancreas and is potentiated by agents mobilizing cellular Ca(2+) (CCK(8) and bethanechol).7. These data indicate species-specific variation in the action of cyclic AMP in the pancreas.

Amylases↗
PubMed1982

Nonparallel transport of exportable proteins in rat pancreas in vitro.

The relative change in in vitro discharge of amylase (or total protein) versus pulse-labeled protein from rat pancreatic fragments was studied after in vivo stimulation with bethanechol or saline injections. Bethanechol was injection were pulse-labeled for 5 min with [14C]L-phenylalanine. The pulse was chased for 60 min. In fragments derived from animals injected with saline, ratio of amylase (or total protein) to new secretory protein decreased at 5 and 15 min but there was no change at 45 min of in vitro incubation with 5 X 10-5 M bethanechol. In fragments derived from animals injected with bethanechol, ratio of amylase to radiolabeled secretory protein decreased at 5 and 15 min and the ratio of total protein to radiolabeled secretory protein secretion decreased at 5 but not at 15 and 45 min. There was a lack of parallelism between the ratios of amylase to radiolabeled protein secretion and total protein secretion to radiolabeled protein secretion in animals injected with bethanechol in vivo followed by in vitro incubations. These experiments indicate that the older proteins are preferentially secreted under nonstimulated conditions and mixing of granules occurs following stimulation. The time required for mixing varies depending on whether the cells are stimulated or not. These data provide support for the concept that there may be more than one subpopulation of zymogen granules in the acinar cell leading to nonparallel enzyme secretion.

Amylases↗