Search PubMed⌕ Search

Biomedical subjects

A Gupta

Publications and source records attributed to A Gupta.

At least 757 records · Page 42Linked to original sources
PubMed1991

Ocular complications in renal allograft recipients.

Ocular complications in renal allograft recipients are a significant cause of morbidity. Of 80 renal transplant recipients, 42 (52.5%) developed ocular complications. These included posterior subcapsular cataract in 22 patients (27.5%), opportunistic ocular infections by CMV, cryptococcus, mucormycosis, herpes simplex and herpes zoster in five (6.25%), steroid-induced raised intraocular pressure in four (5%) and primary disease-related vascular complications in ten (12.5%). Our findings highlight the importance of regular ocular examination of all allograft recipients in the post-transplant period.

Adolescent↗
PubMed1991

Termination of paroxysmal supraventricular tachycardia with a nasogastric tube--a case report.

The case is described of a 29-year-old man with a history of recurrent attacks of paroxysmal supraventricular tachycardia. The patient presented to the emergency ward with complaints of palpitations which had not been relieved by vagal stimulation maneuvers and propranolol. When intravenous metoprolol failed to convert the rhythm, a nasogastric tube was passed which immediately converted the tachycardia to normal sinus rhythm. The literature is reviewed and problems and complications of various techniques are discussed.

Adult↗
PubMed1991

Solitary retinal astrocytoma.

A two-year-old female child presented with a left retinal mass in front of the optic disc and total serous retinal detachment. Enucleation was performed for suspected retinoblastoma. Histopathologically the tumour was composed of astrocytic giant cells with a few spindle-shaped astrocytes. Presence of multiple necrotic foci in the tumour resembling micro-abscesses and extension of tumour cells beyond lamina cribrosa were additional unusual features.

Astrocytoma↗
PubMed1991

Identification of related DNA sequences in Borrelia burgdorferi and two strains of Leptospira interrogans by using polymerase chain reaction.

The suitability of a polymerase chain reaction assay for Borrelia burgdorferi in epidemiological studies of infected tick populations was evaluated by using 28 strains of Leptospira interrogans and lysates of fixed adult Ixodes tick tissues. Two false positives representing leptospires were differentiated from B. burgdorferi by using an oligonucleotide probe.

Animals↗
PubMed1991

Is rheumatoid arthritis in Indians associated with HLA antigens sharing a DR beta 1 epitope?

HLA class II antigens were identified in a group of 44 patients with rheumatoid arthritis (RA) originating largely from the north or northeast of the Indian subcontinent and resident now in east London. Compared with 67 locally typed east London Asian controls, the prevalence of three HLA-DR antigens was raised in the patients: DR1 18.2% v 6.0% chi 2 = 3.99, DR4 20.5% v 11.9% chi 2 = 1.48, and DRw10 27.3% v 8.9% chi 2 = 6.56. These differences were also found when the patients with RA were compared with a larger control group of 110 northern Indians: DR1 18.2% v 7.2% chi 2 = 4.02, DR4 20.5% v 7.2% chi 2 = 5.56, and DRw10 27.3% v 8.1% chi 2 = 9.7. Twenty five (57%) of the patients expressed at least one of these antigens. All patients were also characterised for HLA-Dw types by mixed lymphocyte culture typing. The prevalence of the HLA-DR4 associated Dw types in the patients was: Dw4 2.3%, Dw10 0%, Dw14 11.4%, and Dw15 6.8%. The DR beta 1 chains of DR1 and DRw10 together with the Dw types of DR4 other than Dw10 share amino acid residues in a region of the third hypervariable region considered to be critical in antigen presentation. It is concluded that RA in Indians is associated with these HLA antigens, and data from this study support the hypothesis of a cross reactive epitope common to HLA specificities associated with RA.

Arthritis, Rheumatoid↗
PubMed1991

Effects of pH on phosphate transport by flounder renal tubule primary cultures.

Transepithelial phosphate (Pi) fluxes were determined in primary monolayer cultures of the winter flounder proximal tubule in Ussing chambers. Net Pi secretion, peritubular (P)-to-lumen (L) net flux (Jnet = 17.0 +/- 3.77 nmol.cm-2.h-1), was strongly stimulated by lowering peritubular pH to 6.5 (pHP 6.5 vs. pHL 7.5) compared with control tissues at pH 7.5 (pHP 7.5 vs. pHL 7.5) where net reabsorption (L-to-P Jnet = 1.10 +/- 0.36 nmol.cm-2.h-1) occurred. The stimulation of net secretion by pHP 6.5 was inhibited to 27% of control by 200 microM amiloride. The imposition of a reversed pH gradient (pHL 6.5 vs. pHP 7.5) did not stimulate Pi secretion. Preincubation with 0.5 U/ml phospholipase C caused a nearly fivefold stimulation of Pi secretion compared with the untreated controls. H-7 (100 microM), a protein kinase inhibitor, caused a 2.5-fold reduction in phorbol ester (PE)-induced stimulation of Pi secretion. H-7 also significantly inhibited Pi secretion (50% reduction) when peritubular pH was lowered to 6.5. PE-induced net Pi secretion was significantly lower when luminal pH was lowered to 5.5 compared with controls where luminal pH was kept at 7.5. Amiloride (200 microM) significantly inhibited the PE-induced net Pi secretion in the presence of luminal pH 7.5 but had no significant effect at luminal pH 5.5. Replacement of luminal NaCl with LiCl or isosmolar mannitol significantly reduced net phosphate secretion under the conditions of lowered peritubular pH. Net Pi secretion was also dependent on the maintenance of a cellular Na+ gradient, since 100 microM ouabain inhibited PE-induced net Pi secretion.(ABSTRACT TRUNCATED AT 250 WORDS)

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1991

Localization of ral, a small Mr GTP-binding protein, to collecting duct cells in bovine and rat kidney.

Plasma membranes from bovine kidney cortex were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and transferred to nitrocellulose membranes. Blotting with [alpha-32P]GTP and [35S]GTP gamma S demonstrated specific binding to three and six distinct protein bands, respectively, in the 20,000- to 29,000-Mr range. This indicated the presence of small Mr GTP binding proteins (smg) in bovine kidney cortex. Only one smg with 28,000 Mr was labeled with hydrolysis-resistant GTP photoaffinity probe p3-(4-azidoanilido)-p1-5GTP (AAGTP). The major smg in platelet membranes that binds GTP on nitrocellulose blots has been identified as ral-Mr 29,000. With the use of an antiserum against the ral A gene product, one of the smg with Mr of 29,000 present in bovine renal cortical plasma membranes was identified as ral. Ral was absent from glomerular homogenate, suggesting that it is localized to the tubular segments of the nephron. Ral was detected only in the particulate fraction and not the cytosol. Further subcellular localization of ral was investigated by immunohistochemical staining. Anti-ral antibody immunostained the apical and basolateral membranes of cells in the cortical and medullary collecting ducts in a speckled pattern in the bovine kidney. In the rat kidney, however, uniform linear staining of cortical and medullary collecting ducts predominantly localized to the apical membrane was observed. To date, no function has been assigned to ral. Localization of the ral gene product to the collecting duct suggests a specific functional role for this GTP-binding protein.

Affinity Labels↗
PubMed1991

Age-related elevation of lipid peroxidation products: diminution of superoxide dismutase activity in the central nervous system of rats.

Alteration in lipid peroxidation products such as lipid peroxides, lipid hydroperoxides were studied in different regions of CNS of ageing rats (13, 26, 52, 78 and 104 weeks). The levels of lipid peroxide and lipid hydroperoxide were increased in various regions of brain and spinal cord. However, the activity of superoxide dismutase was decreased in cerebrum, hypothalamus, hippocampus, cerebellum, brain stem and spinal cord. The present communication demonstrates that the different parts of CNS at 13 and 26 weeks of age have lipid peroxidation products different from that of 104-week-old rats.

Aging↗
PubMed1991

Regulation of cytosolic calcium by parathyroid hormone and oscillations of cytosolic calcium in fibroblasts from normal and pseudohypoparathyroid patients.

UNLABELLED: The second messengers for PTH action on fibroblasts have not been determined. The hypothesis that Ca2+ is a second messenger was examined by spectrofluorometric measurement of cytosolic calcium ([Ca2+]i), of fura-2-loaded human dermal skin fibroblasts. PTH induced: 1) transient elevations of [Ca2+]i due to both Ca2+ influx and intracellular release which were independent of CAMP generation, and 2) membrane depolarization. PTH treatment of fibroblasts depolarized by KCl induced oscillations of [Ca2+]i, but spontaneous oscillatory activity was not observed. Transient elevations of [Ca2+]i similar to that induced by PTH were observed with PTH-related peptide (PTHrp). PTH regulation of [Ca2+]i was normal in fibroblasts from patients with pseudohypoparathyroidism (PHP) type Ia (deficiency of the stimulatory GTP-binding protein, Gs), but PTH induced transient decreases in [Ca2+]i in fibroblasts from patients with PHP type Ib (defective PTH receptor). Both PHP Ia and Ib fibroblasts exhibited: 1) spontaneous [Ca2+]i oscillations, possibly due to voltage gated Ca2+ entry and Ca2+ induced Ca2+ release; and 2) greater sensitivity than normal fibroblasts for release of Ca2+ from intracellular stores when [Ca2+]i was decreased by lowering external Ca2+. CONCLUSIONS: 1) PTH-induced transient elevations in [Ca2+]i in normal fibroblasts result from Ca2+ entry and intracellular release which are independent of CAMP generation; 2) [Ca2+]i homeostasis is altered in PHP fibroblasts, resulting in Ca2+ oscillations; 3) PTH regulation of [Ca2+]i is altered in PHP Ib, but not in PHP Ia fibroblasts.

Calcium↗
PubMed1991

The treatment of Colles' fracture. Immobilisation with the wrist dorsiflexed.

In a prospective study, 204 consecutive patients with displaced Colles' fractures had closed reduction then plaster immobilisation. Three different positions of the wrist in plaster were randomly allocated: palmar flexion, neutral and dorsiflexion. The results in the three groups were compared. Fractures immobilised with the wrist in dorsiflexion showed the lowest incidence of redisplacement, especially of dorsal tilt, and had the best early functional results. Immobilisation of the wrist in palmar flexion has a detrimental effect on hand function; it is suggested that it is also one of the main causes for redisplacement of the fracture. This is discussed in relation to the functional anatomy of the wrist and the mechanics of plaster fixation.

Adolescent↗
PubMed1991

Identification and localization of pertussis toxin-sensitive GTP-binding proteins in bovine kidney glomeruli.

The vascular tree and the mesangium in the glomerulus respond to various hormones, growth factors, and autonomic signals, leading to generation of second messengers and regulation of ion channels. Guanine nucleotide regulatory proteins (G proteins) mediate these effects in other systems. Glomerular G proteins were studied by immunoblotting and immunohistochemical techniques. Glomeruli were isolated from bovine kidney cortex by differential sieving. Glomerular proteins were resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and nitrocellulose transfers were immunoblotted with antibodies to G proteins. G alpha,common antiserum (P-960) recognized proteins with a molecular mass of 41 to 45 kDa. Antibodies against peptide sequences specific to Gi alpha and Go alpha demonstrated Gi alpha, 1/3 (molecular mass, 39 to 41 kDa), Gi alpha 2 (molecular mass, 40 kDa), and Go alpha (molecular mass, 39 kDa). Presence of these proteins was further confirmed by pertussis toxin-catalyzed ADP ribosylation of protein(s) with a molecular mass of 39 to 41 kDa in the glomeruli. Immunohistochemical staining of frozen sections from bovine kidney cortex revealed the presence of Gi alpha 2 in capillary loop distribution in glomeruli and interstitium, but Gi,1/3 or Go could not be demonstrated. The pattern of immunofluorescence with Gi alpha 2 antiserum suggested localization of Gi alpha 2 to the endothelium in glomerular and interstitial vasculature. The novel finding of Go in glomeruli requires localization of Go to specific cells and determination of its role in glomerular physiology. In conclusion, these studies demonstrate that bovine kidney glomeruli express alpha subunits of pertussis toxin-sensitive GTP-binding proteins Gi,1/3, Gi,2 and Go.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Diphosphate Ribose↗
PubMed1991

Gestational cadmium exposure and brain development: a biochemical study.

The neurochemical effects of maternally administered cadmium (50 ppm through drinking water from 0 day of pregnancy) on the whole brain of offsprings exposed during gestation were studied in 7, 14 and 21 days old rats. The developmental pattern of body weight, protein, DNA and RNA contents in brain were not affected in Cd exposed pups of any age group. Brain weights were significantly reduced in exposed pups of postnatal age of 7 and 14 days but were comparable to controls in 21 days old pups. The content of Cd increased significantly in the brain of gestationally exposed pups of 7 days and remained almost stationary throughout the experimental period. The activity of Acetylcholinesterase, Na+, K(+)-ATPase, CNPase, 5'-Nucleotidase in the brain increased significantly from 7 to 21 days of age in control animals. In experimental pups, the activity of most of the enzymes was almost comparable to controls at 7 days of age except succinate dehydrogenase, which was significantly inhibited at 7, 14 and 21 days compared to controls. The activity of other enzymes was also significantly inhibited in the brain of experimental pups compared to controls of 21 days of age indicating marked retardation in the development of these enzymes. However, these changes had no correlation with the accumulation of Cd in the brain. These studies indicate that in utero exposure to Cd may retard the development of certain neurochemicals which may have long term implications on the brain functions.

Animals↗