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Biomedical subjects

S K Gupta

Publications and source records attributed to S K Gupta.

At least 397 records · Page 22Linked to original sources
PubMed1995

Increased incidence of spina bifida occulta in fluorosis prone areas.

Spina bifida, a congenital deformity of the posterior wall of vertebrae of the spine, is a midline defect of skin, vertebral arches and neural tube, usually in the lumbosacral region. Its incidence is reported to be 0.2 to 0.4 per 1000 live births. Various hypotheses have been put forward as etiological factors for spina bifida including consumption of potato affected by blight and hardness of drinking water but these have not been proven. Two groups of 50 randomly chosen children were established. The study group consisted of children aged 5 to 12 years, weighing 15 to 30 kg, consuming fluoride rich drinking water (4.5 and 8.5 ppm fluoride; WHO permissible limit is 1.5 ppm fluoride), and manifesting either clinical, dental and/or skeletal fluorosis. The control group consisted of age and weight-matched children, consuming less than or equal to 1.5 ppm fluoride in drinking water and not showing any evidence of fluoride toxicity. These children were evaluated for antenatal history, general clinical examination (especially for dimples, tufts of hair, haemangioma on skin throughout the length of spine), other congenital abnormalities, evidence of fluoride toxicity, biochemical estimation for fluoride levels in blood and serum and by skiagrams of the spine to examine for the presence of spina bifida occulta. A total of 22 (44%) of the 50 children in group A, the study group, and 6 (12%) of the 50 children in group B, the control group, revealed spina bifida occulta in the lumbosacral region.(ABSTRACT TRUNCATED AT 250 WORDS)

Case-Control Studies↗
PubMed1995

The role of routine angioscopy in vascular access surgery.

PURPOSE: The purpose of this retrospective study is to describe our techniques, review our experience, and determine the feasibility, safety, and role of the routine use of angioscopy during primary and revision vascular access surgery. METHODS: Between February 1991 and October 1993, intraoperative angioscopy was routinely performed in 84 consecutive operations (51 patients) for vascular access surgery. We reviewed the videotaped recordings of the angioscopic studies together with the clinical data according to a predetermined protocol. RESULTS: There were 43 primary procedures (36 autogenous arteriovenous fistulas and 7 bridge graft fistulas) and 41 revision procedures for failed vascular access (7 autogenous arteriovenous fistulas and 34 graft bridge fistulas). In 20.9% of the primary vascular access procedures, abnormal endoluminal findings were noted. Based on these findings, only one additional intervention was performed. In revision vascular access surgery, abnormal endoluminal findings were noted in 92.7%, resulting in additional surgical interventions in 65.9% of the procedures. In the revised synthetic bridge graft fistulas, stenosis of the midgraft (n = 9) as a result of needle insertion for dialysis was more common than at venous anastomosis (n = 4). Detection and correction of endoluminal abnormalities resulted in a 30-day patency of 66.6% as opposed to 33.3% when none was detected (p < or = 0.012, Fisher's exact test). CONCLUSIONS: Routine angioscopy is technically feasible and can be performed safely in anuric patients during vascular access surgery. It provides additional and useful intraoperative information that may significantly alter the surgical procedure. Routine angioscopy may also provide new insights into the pathophysiology of vascular access failure.

Adult↗
PubMed1995

Characterization of P. aeruginosa pili binding human corneal epithelial proteins.

Soluble human corneal epithelial proteins (hcep) to which P. aeruginosa pili bind were identified and characterized using gel electrophoresis and Western blotting techniques. Pilus binding proteins were identified using nitrocellulose membrane blots of one dimensional polyacrylamide gels (1-D-SDS-PAGE) of solubilized hcep and a pilus overlay assay. Five major proteins of approximate molecular weights < 21, 38, 45, 66, 97 (a doublet) kilodaltons (kDa) and two additional proteins of > 97 kDa bound pili using an overlay assay and immunoblotting with the monoclonal antibody (MAb) XLR-3, specific for pili. Several of these pili binding proteins were confirmed as single proteins using a similar pilus overlay assay and blotted proteins from two-dimensional polyacrylamide gels (2-D-SDS-PAGE) of hcep. A solid-phase binding assay confirmed that pili binding to hcep was specific, competitive and saturable. The importance of the carbohydrate portions of corneal pili binding proteins was assessed by preincubation of 1-D gel blots of hcep or dot blots of selected eluted pilus binding proteins ( < 21, 38, 45, 66 and 97 kDa) with periodic acid. Mild periodate oxidation of blots before pilus overlay assay completely abolished pili binding. The role of glycosylation of proteins also was assessed using 1-D blots of hcep or dot blots of eluted pilus binding proteins. These blots were preincubated with different lectins before incubation with pili in the pilus overlay assay. Of several lectins examined, only sConA, which recognizes terminal mannose residues, prevented pili binding in the pilus overlay assay. These studies provide evidence that several human corneal epithelial glycosylated proteins provide receptor sites for bacterial pili binding, and that the binding of pili to these proteins is specific, competitive and saturable. They also show that the carbohydrate mannose functions as an integral component of hcep pili binding receptors.

Antibodies, Monoclonal↗
PubMed1995

Prevalence of ticks in relation to their role as vector of Borrelia burgdorferi under autochthone conditions.

A total of 59 (78.7%) of 75 areas were found to be inhabitated by ticks; all the 4335 collected ticks were identified as Ixodes ricinus. Both nymphs and adults were found to be more active during the late spring and early summer months. Ticks of 29 recreation areas were found to be carrying spirochaetes. Considering the total number of 75 recreation areas examined and the total number of 59 areas inhabitated by ticks the percentage was 38.7 and 49.2 respectively. The positivity rate by dark field microscopy was 16.7% in 653 tick samples (single nymphs 8.8%, pooled nymph samples 21.5%, single females 10.9% and single males 10.8%). Overall positivity rate by culture examination of 245 samples was 22.8%. It was maximal in nymphs (24.7%) followed by males (21.1%) and females (19.7%). 10.2% of the 177 samples, found negative by DFM, were positive by this method. A positivity rate of 23.9% in 96 tick samples was found by IFAT. A total of 56 spirochaete-strains were obtained of which 51 could be maintained further; 50 strains were identified as Borrelia burgdorferi.

Animals↗
PubMed1995

A community-based evaluation of eyesight and spectacle use after intracapsular cataract extraction in northern India.

The visual outcome and extent of aphakic spectacle use at community level was evaluated in 177 patients who underwent ICCE in peripheral camps. In 16.9%, both eyes were operated. The mean age at cataract surgery was 63 years (range 33-82 years). After surgery, 79.7% had better vision; 72.3% were extremely satisfied with the surgical outcome. Of those with improved or similar vision, 81.9% were regularly using aphakic spectacles. Free aphakic spectacles after surgery were received by 57.6%. Broken spectacles was the most common cause for not using or intermittently using spectacles. The major benefits to patients were the ability to undertake personal activities, improved mobility and recognition of family members, friends and cattle.

Adult↗
PubMed1995

Recurrent Guillain Barre' Syndrome: a clinical, electrophysiological and morphological study.

Of the 220 patients of acute idiopathic demyelinating polyneuritis (AIDP/GBS) seen over a seven year period, 15 patients (M:F:11:4) had a relapsing course (6.8%). Their ages ranged from 8 yrs to 70 yrs. They had 36 episodes at a variable interval of 3 months to 25 yrs. Relapse rate varied from one to four. Antecedent events were noted during 16 episodes in 9 patients but the triggering factors were varied. Clinical features of individual episodes were similar to the acute monophasic illness, although they differed inseverity from one episode to the other. Autonomic disturbances were rare. Albuminocytological dissociation was observed during 19 of the 24 episodes. Electrophysiological abnormalities were observed during 19 of the 24 episodes. Electrophysiological abnormalities were present in all and were comparable with patients of non-recurrent illness. Sural nerve biopsy in 3 patients showed evidence of demyelination, remyelination, Wallerian degeneration and myelin breakdown but none had features of inflammation. With the exception of one death, functional recovery was complete in the majority of patients, irrespective of the type of therapeutic intervention. Acute onset, frequent facial involvement, brief clinical course, near complete recovery and very long asymptomatic periods may distinguish these patients of acute relapsing demyelinating polyneuropathy (ARDP) from chronic relapsing demyelinating polyneuropathy. Relapses in GBS are however unpredictable and recurrent GBS is indistinguishable clinically, electrophysiologically and morphologically from the more frequently seen non-recurrent form of monophasic GB Syndrome. A biochemical or immunological marker may help in this distinction.

Adolescent↗
PubMed1995

Acute inflammatory demyelinating neuropathy: a critical evaluation of diagnostic criteria for demyelination.

There is agreement on the clinical diagnostic criteria for acute inflammatory demyelinating polyneuropathy (AIDP/GBS) however, there is lack of consensus for detection of demyelination. In order to critically evaluate the prevailing criteria, sixty-six patients who fulfilled NINCDS criteria and had typical features of GBS were studied for electrophysiological abnormalities of peripheral nerves by using standard methods (median, common peroneal, sural and ulnar) between 1 to 12 weeks after the onset of symptoms. The commonest abnormality on motor nerve conduction study was prolonged distal latency (75%-83%) followed by reduction in CMAP amplitude (63%-82%), decreased velocity (48%-62%), conduction block (17%-39%) and f-wave abnormalities (37.8%-59%). Sensory conduction abnormalities were detected in over 20% of median, 25% of ulnar and 33% of sural nerves. All the patients had abnormality of at least two motor conduction parameters in one nerve when values beyond 2 SD of the mean were considered abnormal and over 70% of patients had three abnormalities in two nerves or two abnormalities in three nerves. Comparison with the prevailing criteria for demyelination revealed that the number of patients fulfilling them varied widely: Albers et al. (1985): 74.2%, Albers et al. (1989): 40.9% and Cornblath: 30.3%. We believe that the current criteria for detection of demyelination in acute neuropathy are too strict, underestimate the underlying pathology in GBS and need reassessment.

Adolescent↗
PubMed1994

Somatic mutation of immunoglobulin lambda chains: a segment of the major intron hypermutates as much as the complementarity-determining regions.

The rate and nature of hypermutation of immunoglobulin genes are of prime importance in the affinity maturation of antibodies. Although a considerable body of information has been gathered for kappa light chains, there is much less data for lambda chains. We have derived a large data base of somatic mutants of mouse lambda 1 light chains from Peyer's patches germinal center B cells. The endogenous lambda 1 genes mutate at a rate comparable to that previously found for a kappa transgene (V kappa ox1). There are intrinsic hot spots of mutation common to both in-frame and out-of-frame rearrangements; these hot spots cluster in hypermutating domains. In contrast to the pattern seen for V kappa Ox1, the hot spot clusters are found not only in complementarity-determining region (CDR)1 but also in CDR2 and CDR3; mutations also cluster in the joining/constant region intron. The differences between the pattern of mutations in V kappa Ox1 and lambda 1 light chains are discussed.

Amino Acid Sequence↗
PubMed1994

Cytogenetic effects of deltamethrin on rat bone marrow.

Deltamethrin, a synthetic pyrethroid insecticide, was administered to adult female albino rats as a single i.p., s.c., or oral dose of 5.6, 8.4, or 11.2 mg/kg b.w. or repeated i.p. doses of 2.24 mg/kg b.w. for five consecutive days (cumulative dose 11.2 mg/kg b.w.). This treatment inhibited the mitotic index in a dose-dependent manner and increased the frequency of chromosome aberrations in the bone marrow at 24 h post exposure. The parenterally (i.p. and s.c.) administered deltamethrin appeared more effective than the oral gavage for eliciting its cytotoxicity and genetic toxicity potential. The frequency of micronucleated erythrocytes in the bone marrow was also increased at 30 h following a single i.p. dose of 5.6, 8.4, or 11.2 mg/kg b.w. The most prevalent abnormality observed in this study was endomitotic reduplication of chromosomes which, along with mitotic inhibition and micronucleus induction, indicated microtubular/mitotic spindle poisoning by deltamethrin. The increased frequency of chromosome aberrations and micronucleated erythrocytes also suggests a clastogenic potential of deltamethrin. These observations indicate the in vivo susceptibility of mammals to the genetic toxicity potential of deltamethrin.

Animals↗
PubMed1994

Expression of a mutant Gi2 alpha subunit inhibits ATP and thrombin stimulation of cytoplasmic phospholipase A2-mediated arachidonic acid release independent of Ca2+ and mitogen-activated protein kinase regulation.

The 85-kDa cytoplasmic phospholipase A2 (cPLA2) is the major hormone and growth factor-regulated enzyme that catalyzes release of arachidonic acid in mammalian cells. Activation of cPLA2 requires elevation of intracellular Ca2+ and the phosphorylation of the cPLA2 enzyme by mitogen-activated protein (MAP) kinase. Down-regulation of protein kinase C by phorbol esters or pertussis toxin catalyzed ADP-ribosylation of Gi proteins inhibits thrombin and ATP receptor-stimulated MAP kinase and arachidonic acid release, indicating that functional protein kinase C and Gi proteins are required for G protein regulation of arachidonic acid release. A mutant G alpha i2 subunit having Gly203 mutated to Thr (alpha i2G203T) inhibited thrombin and ATP receptor stimulation of arachidonic acid release independent of adenylyl cyclase inhibition, Ca2+ mobilization, and MAP kinase activation. Overexpression of the wild-type alpha i2 polypeptide or the inactive mutant alpha i2G204A (Gly204 mutated to Ala) polypeptide had no effect on thrombin or ATP receptor stimulation of arachidonic acid release. The phenotype observed with expression of the mutant alpha i2G203T polypeptide defines a role for Gi2 in the control of cPLA2 activity and subsequent arachidonic acid release in addition to the regulation of intracellular Ca2+ levels and MAP kinase activity.

Adenosine Triphosphate↗
PubMed1994

Lymphoglandular bodies in lymphoid lesions and non-lymphoid round cell tumours: a quantitative assessment.

Lymphoglandular bodies (cytoplasmic fragments) were counted in 10 high power fields (HPF) of the smears in 35 cases of non-Hodgkin lymphoma (NHL), 26 Hodgkin's disease (HD), 36 reactive lymphadenitis, 24 non-lymphoid round cell tumors, and 20 cases of secondaries in lymph nodes. The number of lymphoglandular bodies in both May-Grünwald-Giemsa (MGG) and hematoxylin-eosin (H&E) stained smears in NHL, HD, and reactive lymphadenitis were significantly higher compared to non-lymphoid round cell tumors (P < 0.001). In H&E stained smear 92.5% of NHL, 86.2% of reactive lymph nodes, and 66.7% of HD cases had > 100 lymphoglandular bodies per 10 HPF. In MGG stained smears 100% NHL, 89.7% of reactive lymphadenitis, and 66.7% of HD cases contained > 100 lymphoglandular bodies per 10 HPF. On the other hand only 4.8% of non-lymphoid round cell tumors crossed this level in both H&E stained and MGG stained smears. Number of lymphoglandular bodies was also significantly higher in MGG stained smears compared to H&E stained smears (P < 0.05 to < 0.01) and in fine-needle aspiration (FNA) smears compared to imprint smears (P < 0.01 to < 0.001) in cases of NHL, HD, and reactive lymphadenitis.

Adolescent↗
PubMed1994

Pharmacokinetics of orally and intravenously administered cyclosporine in pre-kidney transplant patients.

The pharmacokinetics of cyclosporine (CSA) and four metabolites were evaluated in eight hemodialysis subjects awaiting renal transplantation to compare metabolic patterns with those observed in post-transplant patients and normal volunteers. Each subject received a single 4-mg/kg intravenous and a single 10-mg/kg oral dose separated by a 1-week washout period. Blood samples were collected before and at .5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 14, and 24 hours after CSA dosing. Cyclosporine blood, plasma, and metabolite (M17, M1, M18, M21) levels were determined by high-pressure liquid chromatography. Mean (+/- standard deviation) CSA blood clearance was .47 +/- .15 L/hour/kg, steady-state volume of distribution (Vss) was 1.9 +/- .5 L/kg, and mean residence time (MRT) was 4.4 +/- 1.8 hours after intravenous dosing. With plasma, mean clearance was .70 +/- .31 L/hour/kg, Vss was 2.4 +/- 1.2 L/kg, and MRT was 3.7 +/- 2.2 hours. Cyclosporine bioavailability (F) averaged 24 +/- 11 and 24 +/- 15%, using blood and plasma, respectively. Values for clearance and Vss were approximately 30 to 100% greater than comparable estimates in healthy volunteers, but F and MRT were not altered to this extent. These changes might be explained on the basis of decreased protein binding in uremic patients. The area under the curve ratio for M17 and M1 to CSA increased an average of 1.7- and 3.9-fold, respectively, after oral dosing compared with intravenous administration, indicating increased conversion during first-pass metabolism.

Administration, Oral↗