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S Chugh

Publications and source records attributed to S Chugh.

At least 19 recordsLinked to original sources
PubMed2005

Evaluation of methods for AmpC beta-lactamase in gram negative clinical isolates from tertiary care hospitals.

The purpose of this study was to simultaneously screen for Extended-spectrum beta-lactamases (ESBL) and AmpC beta-lactamases in gram negative clinical isolates from four tertiary care hospitals and further to compare two detection methods three-dimensional extraction method and AmpC disk test for AmpC beta-lactamases. A total of 272 isolates were screened for ESBL and AmpC beta-lactamase by modified double disk approximation method (MDDM). Synergy observed between disks of ceftazidime/cefotaxime and clavulanate were considered as ESBL producer. Isolates showing reduced susceptibility to either of the test drugs (ceftazidime or cefotaxime) and cefoxitin were considered as presumptive AmpC producers and further confirmed by three-dimensional extraction method and AmpC disk test. A total of 173 (64%) of the isolates were found to be ESBL positive and 61 (23%) showed resistant to cefoxitin. ESBL was detected in 80 (62%) isolates of E. coli and 71 (73%) of Klebsiella spp. The occurrence of AmpC beta-lactamases was found to be 8% (22) of the total isolates and the two detection methods for AmpC beta-lactamase showed concordant results. Screening for ESBL and AmpC can be simultaneously done by MDDM method and confirmation for AmpC beta-lactamase should be carried out routinely in tertiary care hospitals by AmpC disk test, as it is a simple and rapid procedure.

Anti-Bacterial Agents↗
PubMed2001

Staged bilateral total knee replacement--a safer approach in older patients.

Simultaneous bilateral total knee replacement has been advocated for bilateral symptomatic arthritis of the knee. The alternative is staged bilateral total knee replacement. We retrospectively reviewed all the total knee replacements performed in our hospital between January 1996 and July 1999. A total of 455 patients had 533 total knee replacements: 54 patients had simultaneous bilateral total knee replacement, 34 patients had staged bilateral total knee replacement and 367 patients had unilateral total knee replacements. Four patients who had simultaneous bilateral total knee replacement died in the immediate post-operative period. During the same period, no deaths were observed in the other two groups. Risk factors were assessed and in our series, age was the only factor found to be associated with mortality following simultaneous bilateral total knee replacement. A staged operation appears to be safer than simultaneous bilateral total knee replacement for patients who are 75 years or older.

Age Factors↗
PubMed2001

Identification of up-regulated Ras-like GTPase, Rap1b, by suppression subtractive hybridization.

BACKGROUND: Diabetic nephropathy accounts for over 30% of the end-stage renal disease (ESRD). A number of defined mechanisms and molecules that are involved in its pathogenesis are known, while others remain to be identified. METHODS: Suppression subtraction hybridization (SSH)-polymerase chain reaction (PCR) was employed to search for new genes that may be relevant to the pathogenesis of diabetic nephropathy during embryonic development, the time when the kidney is most susceptible to various forms of stress. A diabetic state was induced in pregnant mice at day-13 of gestation by administration of streptozotocin. The kidneys of newborn mice with blood glucose level> 200 mg/dL were harvested, mRNA isolated and subjected to SSH-PCR. Several differentially expressed cDNA fragments with up-regulated expression were isolated. One of the cDNA fragments had homology with human Ras-like guanine 5'-triphosphate (GTPase), Rap1b gene. By utilizing the lambdaZAP II mouse cDNA library and SMART RACE amplification, a full-length Rap1b cDNA was isolated. A recombinant protein was generated in pET15b bacterial expression system. An anti-Rap1b antibody was raised in rabbits by immunizing them with the fusion protein, and its specificity was confirmed by Western blot analysis. RESULTS: Rap1b cDNA had an open reading frame of 552 bp with a predicted putative protein size of approximately 21 kD. In vitro translation verified the authentication of the Rap1b cDNA clone. Northern blot analyses revealed a single approximately 2.3 kb Rap1b mRNA transcript. Its expression was up-regulated in several tissues, including the kidney of newborn diabetic mice. The degree of up-regulation of Rap1b mRNA expression was proportional to the blood glucose levels. Western blot analyses confirmed the hyperglycemia-induced up-regulation of the Rap1b expression. In situ hybridization and immunofluorescence studies revealed that Rap1b was expressed in the inner medullary collecting tubules. During hyperglycemia, its expression was accentuated and extended into the outer medullary and cortical collecting tubules. Similar up-regulation of Rap1b was observed when embryonic kidneys, harvested at day-13 of gestation, were exposed to high glucose ambience. CONCLUSION: The data suggest that Rap1b, a GTP-binding protein that plays a critical role in various signaling intracellular events, is another molecule that may be relevant to the pathobiology of diabetic nephropathy.

Amino Acid Sequence↗
PubMed2001

Aminopeptidase A: a nephritogenic target antigen of nephrotoxic serum.

BACKGROUND: We investigated potential targets of antibody-mediated glomerular injury induced with a noncomplement binding fraction of sheep anti-rat nephrotoxic serum (NTS). This model is characterized by severe complement- and leukocyte-independent proteinuria within 24 hours of NTS injection into rats. METHODS: NTS-reactive glomerular cell and matrix proteins were identified by immunoprecipitation, Western blot analysis, protein sequencing, cDNA library screening, and enzyme-linked immunosorbent assay. Proteinuria was measured in rats injected with NTS from which reactivity against type IV collagen had been removed by immunoadsorption, and antibodies were eluted from the glomeruli of proteinuric rats that had been injected with unabsorbed NTS. Having identified aminopeptidase A (APA) as a major target of NTS, we studied the effect of NTS and anti-APA on mouse glomerular epithelial cells in culture. RESULTS: NTS identified several podocyte and matrix proteins; however, APA was the only cell surface protein reactive with antibodies eluted from the glomeruli of rats injected with NTS. Although the eluate also contained reactivity to the noncollagenous domains of alpha1 and alpha3 chains of type IV collagen, immunodepletion of these antibodies did not diminish the ability of NTS to cause proteinuria. We also documented the surface expression of APA on mouse glomerular epithelial cells in culture, and found that NTS and specific anti-APA antibodies induce a time- and temperature-dependent redistribution of the antigen. CONCLUSIONS: APA, a type II integral membrane metallopeptidase, is a major target of NTS in vivo and is known to be present on the surface of podocytes. NTS-induced proteinuria is independent of reactivity to known nephritogenic matrix proteins. These findings, in combination with previous studies showing that monoclonal anti-APA antibodies induce severe proteinuria in mice, suggest that anti-APA antibodies are responsible for complement-independent proteinuria in this model.

Aminopeptidases↗
PubMed1999

Nephritogenic mAb 5-1-6 is directed at the extracellular domain of rat nephrin.

mAb 5-1-6 identifies an antigen on rat podocyte slit-diaphragms and induces severe proteinuria when injected into rats. Nephrin, an Ig-like transmembrane protein that is mutated in congenital nephrotic syndrome of the Finnish type, has been localized to the slit-diaphragm on human podocytes. Here we document that the mAb 5-1-6 antigen is rat nephrin. After incubation of rat glomeruli with this mAb, the antibody/antigen complex was chemically cross-linked, extracted, and immunoprecipitated, prior to Western analysis. By mass spectrometry and 2D gel electrophoresis, we identified several peptides with complete identity to human nephrin. In addition, the 185-kDa protein immunoprecipitated by mAb 5-1-6 from rat glomerular extracts reacts with a rabbit anti-mouse nephrin antibody. Finally, nephrin and the mAb 5-1-6 antigen have identical glomerular localization patterns on immunofluorescence of rat kidney. These results demonstrate that the nephritogenic mAb 5-1-6 identifies the extracellular domain of nephrin, thereby documenting the importance of the slit-diaphragm and its component, nephrin, in the regulation of glomerular permselectivity.

Amino Acid Sequence↗
PubMed1998

Autologous bone grafting in staged scoliosis surgery. The patient as bone bank.

STUDY DESIGN: A prospective clinical study in which autologous rib graft, harvested during the thoracotomy in staged scoliosis correction, is stored within the patient for use during the second stage (posterior intrumentation and fusion). OBJECTIVE: To determine whether the bone stored by this technique is biologically viable and microbiologically safe. SUMMARY OF BACKGROUND DATA: To the authors' knowledge, this method of storage of bone has never been described previously. METHODS: During the first operation, the excised rib was divided into 3-5 cm fragments and stored in a sub-muscular plane adjacent to the posterior elements of the spine before closure. The graft was then retrieved at the second stage. Samples were sent for histologic and microbiologic examination before implantation. RESULTS: On histologic examination, more than 50% of the osteocytes retained their basophilic staining, indicating that they were viable. In addition, osteoclastic activity was notably absent. There was no significant bacterial contamination of the samples. Clinically, all patients achieved satisfactory bone fusion. CONCLUSION: Homeostatic equilibrium in humans provides the ideal environment in which bone graft can be stored. There is no increased risk of infection, and the osteogenic potential of the graft is retained.

Bone Transplantation↗
PubMed1993

Polymyositis associated with ulcerative colitis.

An elderly woman with chronic ulcerative colitis who developed proximal muscle weakness, increased serum creatine phosphokinase activity, and histological and electromyographic abnormalities characteristic of polymyositis is described. Treatment with corticosteroids and 5-acetylsalicylic acid was followed by a remission in bowel symptoms, improvement in muscle power, and reversal of electromyographic changes. An autoimmune link between the two disorders seems likely.

Aged↗
PubMed1993

Invasive pulmonary aspergillosis and nocardiosis in an immunocompromised host.

A case of invasive pulmonary aspergillosis and nocardiosis following high dose prolonged steroid therapy given for suspected rapidly progressive glomerulonephritis is reported. A favourable response was achieved with a combination of amphotericin B and cotrimoxazole. A high index of suspicion and aggressive investigations are necessary for confirmation of diagnosis and early institution of appropriate therapy.

Amphotericin B↗
PubMed1993

Renal amyloidosis in juvenile rheumatoid arthritis.

We report a child who developed juvenile rheumatoid arthritis at the age of 7 years and nephrotic syndrome due to renal amyloidosis within 2 years of the onset of arthropathy. Literature on the management and prognosis has also been reviewed.

Amyloidosis↗
PubMed1992

Psychiatric morbidity in the families of paranoid and non-paranoid schizophrenia patients.

A total of 1018 and 812 first degree relatives (FDR) of schizoprencies and controls respectively, were studied to find out the psychiatric morbidity in the families of paranoid and non-paranoid schizophrenia patients. The risk of schizophrenia and affective disorders was found to be independent of the probands subtype diagnosis. The risk for schizoid-schizotypal and paranoid personality disorders was found to be increased in the first degree relatives of paranoid schizophrenic, as compared to non-paranoid schizophrenic, thus suggesting that the psychopathology in the FDR may differ with the subtype diagnosis of the proband.

Adolescent↗