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Biomedical subjects

D K Gupta

Publications and source records attributed to D K Gupta.

At least 163 records · Page 9Linked to original sources

Split notochord syndrome presenting with meningomyelocoele and dorsal enteric fistula.

Split notochord syndrome is a rare congenital anomaly. We present the history of a 16-day-old male infant who presented to us with a lumbosacral meningomyelocoele and a dorsal enteric fistula along with the cleft of lower vertebrae. Review of the literature, has revealed eight such cases with very few survivals. We successfully treated the patient.

Humans↗

On the division of trypanosomes in Colisa fasciata (Perciformes) in vivo.

In vivo observation of the division in the trypomastigotes of the fish trypanosome, Trypanosoma trichogasteri, from Colisa fasciata is hereby reported for the first time. The division is initiated with the duplication of the kinetoplast followed by nuclear division and cytokinesis. Contrary to earlier reports, cytokinesis commences from the posterior end and the flagellum originates simultaneously or subsequent to cytoplasmic separation.

Animals↗

Comparison of biosynthesis and subcellular distribution of lysozyme and lysosomal enzymes in U937 monocytes.

Using metabolic labelling and sucrose density fractionation we compared the synthesis of lysozyme and lysosomal enzymes in human monocytic U937 cells. In pulse-chase experiments in sucrose density gradients, the intracellular radioactively labelled lysozyme distributed similarly to cathepsin D and beta-hexosaminidase. With the aid of immunochemical detection in Western blots, the steady-state distribution of lysozyme was found to be slightly different from that of beta-hexosaminidase; relatively more lysozyme was present in fractions sedimenting between lysosomes and the Golgi apparatus. The observed distribution of the lysozyme antigen with a prominent peak in the lysosomal fraction was in striking contrast to the broad distribution of the lysozyme activity. The difference was explained by a bias in the determination of the activity of lysozyme by the 'lysoplate' diffusion assay.

Cathepsin D↗

Tilorone acts as a lysosomotropic agent in fibroblasts.

Tilorone, an amphiphilic cationic compound with antiviral activity perturbed the lysosomal system. In cultured fibroblasts tilorone induced storage of sulfated glycosaminoglycans, enhanced secretion of precursor forms of lysosomal enzymes, inhibited intracellular proteolytic maturation of lysosomal enzymes, and inhibited receptor-mediated endocytosis of lysosomal enzymes. In isolated lysosomes tilorone was found to increase pH and to abolish the ATP-dependent acidification. These effects suggest that tilorone acts like a weak base that accumulates in acid compartments of the cells, raises the pH therein and interferes with lysosomal catabolic activity and with receptor-mediated transport of lysosomal enzymes.

Cathepsin D↗

Processing and transport of lysosomal enzymes in human monocyte line U937.

Precursors of cathepsin D and beta-hexosaminidase synthesized in the U937 monocyte line are processed to mature forms with similar kinetics as in fibroblasts. In U937 cells the processing of the precursor of the beta-chain of beta-hexosaminidase, however, results in a larger fragment that resembles a processing intermediate in fibroblasts. This difference is explained by differences in the equipment of the cells with proteinases, since cross-feeding of the precursors to the cells results in a processing characteristic for the recipient cell type. In sucrose gradients the precursors are found partly in a low- and partly in a high-density region. Mature polypeptides and activity of lysosomal enzymes fractionate mainly in the higher density region. In U937 cells the transport and maturation of endogenous lysosomal enzymes are less sensitive to bases (NH4Cl, chloroquine, tilorone) and to antibody against the mannose 6-phosphate specific receptors than in fibroblasts. A small portion of enzymes released from U937 cells contains the markers recognized by the mannose-6-phosphate specific receptors. U937 cells express these receptors and utilize them for transport of endogenous and exogenous lysosomal enzymes. It appears, however, that a fraction of lysosomal enzymes is transported in U937 cells independent of the mannose-6-phosphate-specific receptors.

Biological Transport↗

A psychiatric study of amputees.

Psychiatric manifestations were studied in 72 amputees in the post-operative period. All were right handed. Besides phantom limb phenomena, which were observed in nearly four-fifths of the cases and are described in another paper, nearly two-thirds had psychiatric symptoms inthe form of depression (45 patients), anxiety (38), crying spells (38), insomnia (34), loss of appetite (23), suicidal ideas (21) and psychotic behaviour (2). Right arm amputees had phantom phenomena and insomnia significantly more often than left. Nearly one-fifth of the cases were diagnosed as having psychotic depressive reactions, two-fifths as having depressive neurosis and two, both with right upper limb amputations, as schizophrenic.

Adolescent↗

Phantom limb: a phenomenological study.

Phantom limb phenomena during the post-operative period were studied in 72 amputees. All were right handed. Phantom limb was present in 86.1 per cent of the cases, significantly more commonly amputation of the right arm. Nearly half of the phantoms developed within the first 24 hours and another quarter in the next 24 hours, appearing earlier in lower limb amputees. Movements in the phantom were felt by three-quarters of the cases, an incidence unaffected by site or side of amputation. Telescopy was present in nearly two-thirds and phantom limb pain in over two-thirds, significantly more commonly in the upper limb amputees but uninfluenced by the side of amputation. Thirty-one of the patients dreamed that their limbs were intact.

Adolescent↗