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D K Gupta

Publications and source records attributed to D K Gupta.

At least 145 records · Page 8Linked to original sources
PubMed1990

Biochemical analysis of glycophospholipids from wild-type mouse lymphoma cells and from Thy-1 negative mutants which do not add glycolipid-anchored proteins.

Thy-1 is a major glycophospholipid (GPL)-anchored protein found on the surface of neurons, epithelial cells, fibroblasts and murine T-lymphomas. Biochemical studies were undertaken to determine if murine T-lymphomas contain glycolipids which may be on the path of GPL-anchor biosynthesis. Biosynthetic labeling experiments on Thy-1-positive (wild-type) cells followed by battery of chemical and enzymatic diagnostics on the isolated [3H]mannolipids have, for the first time, led to description of a set of glycolipids which have properties consistent with their being GPL-anchor precursors. Using these results as a guide, major differences have been observed upon analysis of the radiolabeled mannolipids of Thy-1-negative mutants from 7 complementation classes, A-C, E, F, H and I. The biosynthetic lesions in anchor synthesis have been identified in some of the mutants.

Animals↗
PubMed1990

Impedance plethysmographic observations in thoracic outlet syndrome.

Forty patients with symptoms of neuro-vascular compression in the upper extremities were subjected to impedance plethysmographic study using Parulkar's method. Two patients recorded decreased blood flow (BFI) in supine position and were diagnosed as having partial occlusion at subclavian level. Sixteen of the patients recorded decreased BFI on 90 degrees abduction and hyper-abduction. Twelve of these patients had radiological evidence of anomalous cervicle ribs. In remaining four patients extrinsic impression on the subclavian artery due to fibrous deposits was confirmed by arteriography. Remaining 22 patients recorded normal impedance plethysmograms. Impedance plethysmography thus provided a non-invasive modality for confirmation of vascular compression in thoracic outlet syndrome.

Adolescent↗
PubMed1990

Diagnosis of venous disorders using impedance plethysmography.

Impedance plethysmography (IPG) was carried out in one hundred and forty-one patients suspected of venous disorders using Parulkar's method. In these patients occlusive impedance phlebography (OIP) and venography were also carried out using standard procedures. Comparison of IPG and OIP observations with venographic findings revealed sensitivity of these methods to be 65% and 77.7% in the diagnosis of primary varicosity of veins and chronic deep vein thrombosis respectively with a specificity of 85%. Occlusive impedance phlebograms showing unilateral decrease in OIP parameters were observed to be sufficiently diagnostic. IPG observations in 5 patients with arterio-venous malformation were observed to be different from those in patients with deep vein thrombosis.

Adolescent↗
PubMed1990

Superoxide generation by neutrophils after exposure to a conventional peritoneal dialysis solution for different time periods.

Neutrophils were isolated from canine blood and exposed to a conventional, acidic, lactate-containing peritoneal dialysis solution for 0, 2 and 4 minutes in one study and 0, 4, 7 and 10 minutes in another. Superoxide generation, expressed in nanomoles per million cells, was determined using a method based on the superoxide dismutase-inhibitable reduction of ferricytochrome c. Brief exposure of neutrophils to a conventional dialysis solution could significantly inhibit the generation of superoxide by neutrophils.

Animals↗
PubMed1989

Isolated ileal-loop endorectal pull-through: a new approach in the management of complicated Hirschsprung's disease.

The isolated ileal-loop endorectal pull-through was performed on two patients with Hirschsprung's disease complicated by disuse atrophy of the distal colon. In both patients there was not only a short length of the proximal ganglionic colon, which could not be safely pulled down to the perineum, but also nonavailability of the distal aganglionic colon, which had to be resected for nonfunctioning disuse atrophy. This technique allowed a safe endorectal pull-through with primary anal anastomosis, and also prevented complications like frequent watery diarrhea, steatorrhea, malabsorption of vitamins A, D, and K, and pernicious anemia frequently observed following popular surgical procedures for long-segment and total colonic aganglionsis.

Anal Canal↗
PubMed1989

Effects of bicarbonate-containing versus lactate-containing peritoneal dialysis solutions on superoxide production by human neutrophils.

Human neutrophils were isolated from healthy volunteers and exposed to either bicarbonate-containing (pH 7.4) or lactate-containing (pH 5.2) peritoneal dialysis solution in vitro. Superoxide production by neutrophils was measured by a method based on the superoxide dismutase-inhibitable reduction of ferricytochrome c. Bicarbonate-containing peritoneal dialysis solution was found to be superior to the lactate-containing one in facilitating the production of superoxide anion by human neutrophils.

Adult↗
PubMed1989

L-lactate for high-efficiency hemodialysis: feasibility studies and a randomized comparison with acetate and bicarbonate.

We evaluated the feasibility of using L-lactate as a base for hemodialysis. In one study, acid-base changes using 40 mM L- or DL-lactate were compared. In a second study, acid-base status using various amounts of L-lactate exclusively was studied. The third study compared symptoms and acid-base changes during 9 weeks of high-efficiency dialysis when using L-lactate, acetate, or bicarbonate as base. In the first study, plasma bicarbonate changes were equivalent with 40 mM L-lactate and 40 mM DL-lactate, but overall correction of acidosis appeared to be suboptimal. In the second study, when compared to a bicarbonate control period, correction of acidosis was reduced when using 40 mM L-lactate + 4 mM acetate solution, but increased when using a 46 mM L-lactate + 4 mM acetate solution. In the third study, correction of acidosis was comparable when using 42 mM L-lactate + 4 mM acetate, 39 mM acetate, or 35 mM HCO3 + 4 mM acetate. Whereas 46% +/- 12 (SEM) treatments "failed" because of symptoms when using acetate, the percentages of "failed" treatments were only 7% +/- 4.2 with L-lactate (p less than 0.05) and 11% +/- 4.2 with bicarbonate (p less than 0.05). The results suggest that L-lactate is a suitable dialysis solution base that is capable of correcting chronic uremic acidosis. During high-efficiency dialysis, the incidence of intradialytic symptoms with L-lactate is comparable to that with bicarbonate and less than that with acetate.

Acetates↗
PubMed1989

Biochemical, kinetic and cytochemical approaches resolve Golgi subcompartments of IgM-secreting rat myeloma cells.

The rat myeloma cells chosen for study (IR202) are highly specialized toward the synthesis and secretion of immunoglobulin M (IgM). In [35S]methionine pulse-chase protocols the half-time for secretion of newly synthesized [35S]Ig at 37 degrees C is approximately 2 1/2 h. No degradation of [35S]Ig was detected in such experiments. Pulse-chase experiments with [3H]galactose show that addition of this terminal sugar occurs only approximately 2 min before discharge. The intracellular pool of Ig bearing mature oligosaccharides is therefore very small. Incubation at 20 degrees C stops secretion of the [35S]- and [3H]Ig. We describe a subcellular fractionation protocol for these cells which results in the recovery of a total microsomal fraction by gel filtration. This fraction includes approximately 1/4 of the galactosyltransferase and uridine diphosphatase (UDPase) of the homogenate. By employing two cytological Golgi markers (an "overosmicatable material" and UDPase), galactosyltransferase activity and [35S]methionine and [3H]galactose pulse-chase protocols with the chase at 15 degrees C we document the partial resolution of Golgi subcompartments in isopycnic sucrose gradients used to subfractionate the total microsomal fraction. Electron microscopic and enzymologic examination of the fractions resolved by these gradients confirm that rough microsomes are well separated from Golgi membranes and that the fractions most highly enriched in galactosyltransferase activity have a protein-based specific activity approximately 10 times that of the total microsomal fraction. These studies, therefore, form the basis for an analysis of the composition of the membranes of the Golgi Complex and document the location of proximal Golgi elements, as defined by cytological criteria, in isopycnic gradients.

Animals↗
PubMed1989

A novel lectin-gold density perturbation eliminates plasma membrane contaminants from Golgi-enriched subcellular fractions.

The availability of pure Golgi fractions is a prerequisite for documenting the composition of the membranes of the Golgi Complex and comparing and contrasting this organelle with the rough endoplasmic reticulum. In a companion article, we have described a subcellular fractionation protocol for rat myeloma cells which effectively eliminates rough microsomes from Golgi-enriched fractions. Nevertheless, a major overlap with plasma membrane remains. We have therefore developed a novel density perturbation procedure to eliminate plasma membrane contaminants. By binding a conjugate of wheat germ agglutinin and colloidal gold to cells at 4 degrees C before homogenization we cause extensive sedimentation of plasma membrane markers to the "mitochondrial pellet" as well as a major shift in the isopycnic density of these markers. The differential and isopycnic sedimentation of several Golgi markers is unaffected in lectin-gold treated cells. The Golgi-enriched fractions obtained by isopycnic sedimentation are therefore of high purity. This procedure may be of general use for either purifying or eliminating plasma membrane-derived vesicles. Adaptations of the method might be equally useful for density perturbation of intracellular organelles.

Animals↗
PubMed1988

Suppression of neutrophil superoxide production by conventional peritoneal dialysis solution.

The pH of conventional peritoneal dialysis solution is normally in the range of 5.0 to 5.5, because acid has been added during the manufacturing process to prevent caramelization of dextrose during sterilization. We studied the effects of normalizing the pH of conventional peritoneal dialysis solution on superoxide production by normal human neutrophils. At a pH of 6.0, superoxide generation was 4.07 +/- 2.56 (SD) nanomoles per million cells. With normalization of pH to 7.4, superoxide production was 19.3 +/- 7.3 (p less than 0.001). The results suggest that the unphysiologic acidity of conventional peritoneal dialysis solution has deleterious consequences on neutrophil superoxide formation.

Adolescent↗
PubMed1988

Mesenteric lipoma.

Explore the source record for details and available documents.

Child, Preschool↗
PubMed1987

Conditions for a reliable application of the lysoplate method in the determination of lysozyme.

Using the 'lysoplate' method, less than 1 ng lysozyme can be detected. However, the sensitivity of this method is strongly dependent on the quality of the diffusion medium and on the presence of substances in the samples that affect the interaction of lysozyme with the gel medium and thus its rate of diffusion. The activity of lysozyme in the 'lysoplate' assay can be titrated with a specific antibody. The titration is suitable for quantitative determination of lysozyme. A screening of serum samples for pathologically increased lysozyme content can simply be performed by assaying lysozyme in samples supplemented with a standard amount of anti-lysozyme antibody.

Antibodies↗