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Biomedical subjects

A Kumar

Publications and source records attributed to A Kumar.

At least 685 records · Page 38Linked to original sources
PubMed1998

Clinical significance of fever after percutaneous nephrolithotomy.

OBJECTIVES: In the immediate postoperative period after percutaneous stone removal, body temperature elevations are common. Pyrexia after a percutaneous nephrolithotomy (PCNL) generates concern because of the possibility of urinary extravasation and bacteremia. We reviewed our experience with PCNL to determine the clinical significance of a postoperative fever before discharge from the hospital. METHODS: Between July 1994 and December 1996, 63 patients underwent 69 PCNLs. Each had documented negative urine cultures preoperatively and received prophylactic antibiotics at the time of surgery. For each case, clinical and operative charts were reviewed to determine stone composition, fever during hospital stay, postoperative bacteriologic cultures, postoperative white blood cell count (WBC), and clinical course. RESULTS: Complete data were available for 66 procedures. Eight patients (12%) had at least one body temperature reading between 38.0 and 38.5 degrees C. Eleven patients (16.7%) had at least one temperature greater than 38.5 degrees C. Each patient with a temperature greater than 38.5 degrees C was hemodynamically stable with negative blood and urine cultures. No patient with a fever between 38.0 and 38.5 degrees C was cultured. Stone analysis did not demonstrate any association between postoperative fever and stone composition (including 22 struvite stones). Postoperative WBC also did not predict pyrexia. Fever alone did not prolong hospital stay. CONCLUSIONS: In patients with negative urine cultures who are prophylaxed with immediate preoperative antibiotics and maintained on postoperative antibiotics, pyrexia after PCNL does not require an immediate bacteriologic evaluation in those who are hemodynamically stable.

Female↗
PubMed1998

Corneal infection after radial keratotomy.

PURPOSE: To evaluate nine eyes that developed corneal infection after radial keratotomy (RK) and their subsequent management. SETTING: Dr. Rajendra Prasad Centre for Ophthalmic Sciences, New Delhi, India. METHOD: The parameters evaluated were interval between RK and development of the ulcer, number of keratotomy incisions, nature of surgery (primary or secondary), status at presentation, and best corrected visual acuity (BCVA). Corneal scrapings were taken from all eyes for microbiological evaluation. Initial therapy was based on clinical impression and subsequent therapy, on the microbiological report. RESULTS: Staphylococcus species were the most frequently isolated bacteria followed by Pseudomonas aeruginosa. Two eyes had fungal growth, and no organisms were isolated from one. All but one eye responded to medical therapy; healing took 23 to 26 days. Therapeutic penetrating keratoplasty (PKP) was done in one eye. Presenting BCVA of hand movement to 6/36 improved to hand movement to 6/18 after the ulcer healed. Final BCVA was 6/36 to 6/9 after lamellar keratoplasty or PKP or with contact lens of spectacle correction. CONCLUSION: Our study shows that corneal infection is a potential complication of RK. Therefore, persistent postoperative irritation should be carefully observed to ensure early diagnosis and prompt therapy.

Adolescent↗
PubMed1998

Endothelin-1-like immunoreactivity in a new rodent model of spontaneous hypertension.

The purpose of this study was to determine plasma and tissue endothelin-1 (ET-1)-like immunoreactivity in a new rodent model of spontaneous hypertension. Plasma and tissues were procured from pentobarbital-anesthetized 16- to 18-week-old male hamsters with spontaneous hypertension and genetically/age-matched normotensive hamsters. We found that ET-1-like immunoreactivity in the plasma was similar in both groups. However, renal and cardiac ET-1-like immunoreactivity was 11- and 1.7-fold higher in spontaneously hypertensive hamsters relative to normotensive hamsters, respectively (P < .05). ET-1-like immunoreactivity was slightly, but significantly, lower in the lung and spleen of spontaneously hypertensive hamsters relative to normotensive hamsters (P < .05). ET-1-like immunoreactivity in the liver and brain was similar in both groups. We conclude that ET-1-like immunoreactivity is significantly higher in two target organs for hypertension, kidney and heart, but not in plasma or brain of adult male hamsters with spontaneous hypertension, relative to genetically/age-matched normotensive hamsters. We suggest that renal and cardiac ET-1 could play a role in the natural history of spontaneous hypertension in hamsters.

Animals↗
PubMed1998

Spontaneous hemobilia in a hemophiliac treated by factor VIII replacement and nasobiliary drainage.

We report a case of spontaneous hemobilia in a hemophilia patient presenting with classical Sandblom's triad of symptoms. Endoscopic retrograde cholangiography was helpful in establishing the diagnosis. Hemobilia subsided with factor VIII replacement and endoscopic nasobiliary drainage. Endoscopic nasobiliary drainage resulted in lysis of the clots in the biliary tree and relief of obstructive jaundice.

Cholestasis↗
PubMed1998

Efficacy of diode laser for managing diabetic macular oedema.

PURPOSE: To evaluate the effect of photocoagulation for diabetic macular oedema using Diode laser in a prospective randomized fashion and comparing its effects with the Argon green laser. METHODS: 40 eyes with focal and diffuse oedema were randomly treated with Diode and 40 eyes were treated with Argon green. Following investigations were performed: visual acuity, fundus evaluation, flourescein angiography and visual fields. RESULTS: 79% treated with Diode had partial to complete regression of oedema and so also 82% with Argon green at six months post laser. CONCLUSIONS: There was no difference in improvement or worsening of visual acuity between the two lasers. This study is of importance as it has been the first prospective randomized study of its kind using Diode laser in diabetic macular oedema.

Diabetes Mellitus, Type 2↗
PubMed1998

Sympathetic ophthalmia associated with antecedent adherent leucoma--a rare association.

PURPOSE: To report a rare association of sympathetic ophthalmia with an antecedent adherent leucoma. METHOD: A 40-year-old patient with an adherent leucoma developed sympathetic ophthalmia in the fellow eye, 15 years after the occurrence of a perforated corneal ulcer. RESULTS: Intravenous pulse dexamethasone therapy followed by tapering oral prednisolone led to complete resolution of the disease process in the sympathising eye. CONCLUSION: Patients with an adherent leucoma subsequent to a perforated corneal ulcer may remain at an increased risk of developing sympathetic ophthalmia during their lifetime.

Administration, Oral↗
PubMed1998

Prone position ultrasonography in silicone filled eyes.

PURPOSE: To evaluate the efficacy of a new technique of prone position ultrasonography in cases with silicone filled eyes. METHODS: Forty patients with prior pars plana vitrectomy and silicone oil instillation referred to a tertiary eye care centre were the subjects of this study. A prospective clinical trial was undertaken to evaluate the efficacy of prone position ultrasonography in addition to routinely performed supine position ultrasonography in these patients. The technique was undertaken by 2 independent observers and compared with the findings by indirect ophthalmoscopy or surgical results. Interobserver variability was also calculated. RESULTS: Two spikes were observed in supine position corresponding to the intravitreal silicone oil surface and the sclera, whereas a single spike corresponding to the sclera was observed in prone position. Supine position ultrasonography yielded a diagnostic accuracy of 61.8%, which increased to 96.7% when the procedure was supplemented with prone position ultrasonography. Specificity increased from 75 to 100% by the addition of this adjuvant procedure, however, with no significant difference in the interobserver variability ('K'=0.67 Vs 'K'= 0.62). CONCLUSION: Prone position ultrasonography is a useful adjunct to the routinely performed supine position ultrasonography in silicone filled eyes and increases the diagnostic yield.

Diagnostic Techniques, Ophthalmological↗
PubMed1998

Complement-regulatory protein expression and activation of complement cascade on erythrocytes from patients with rheumatoid arthritis (RA).

It has been previously reported that the expression of the complement receptor, CR1, on erythrocytes is reduced in patients with RA and that the reduced expression of CR1 is related to disease activity. In this study we investigate the role of other regulatory proteins, i.e. decay-accelerating factor (DAF) and CD59 (membrane inhibitor of reactive lysis), in the pathogenesis of RA by checking the expression of DAF and CD59 on erythrocytes of RA patients to establish whether reduced expression of DAF and CD59 on erythrocytes could be related to increased ability of erythrocytes to activate complement in RA. Flow cytometry was used to measure the expression of DAF and CD59 on erythrocytes from RA patients as well as the deposition of C3 fragments occurring in vivo or after in vitro complement activation. Significantly reduced expression of DAF and CD59 was observed on erythrocytes of RA patients. A significant inverse relationship was observed between DAF expression and in vitro complement activation, whereas no significant relationship between CD59 and complement activation was observed. Finally, we demonstrated an inverse relationship between CH50 activity and DAF expression. Thus, determination of DAF on erythrocytes can emerge as an additional tool in the assessment of extent of complement activation in RA.

Adolescent↗
PubMed1998

Differential production of IL-10 by T cells and monocytes of HIV-infected individuals: association of IL-10 production with CD28-mediated immune responsiveness.

Immune unresponsiveness in HIV-1 infection can result from impaired signals delivered by the costimulatory CD28-B7 pathway and the altered production of immunoregulatory cytokines, in particular IL-10, whose production is altered in HIV-1 infection. In this study we investigate IL-10 regulation in T cells and monocytes from HIV+ individuals, and its association with CD28-mediated T cell proliferation. IL-10 production as analysed in T cell- and monocyte-depleted peripheral blood mononuclear cells (PBMC), and by intracellular staining at the single-cell level, reveals a defect in IL-10 production by CD4+ and CD8+ T cells, whereas monocytes constitute the major IL-10-producing cell type. To investigate the impact of IL-10 on immune responsiveness, CD28-mediated proliferative responses in HIV+ individuals were correlated with PHA-induced IL-10 production. CD4+ T cells expressed CD28, yet exhibited markedly reduced CD28-mediated cell proliferation. This CD28-mediated CD4+ T cell proliferation was found to be inversely associated with the levels of PHA-induced IL-10 production and could be restored, at least in part, by anti-IL-10 antibodies. These results suggest that IL-10 production is differentially regulated in T cells and monocytes of HIV+ individuals, and that IL-10 may have a role in inducing immune unresponsiveness by modulating the CD28-B7 pathway.

Adult↗
PubMed1998

An estimate of phylogenetic relationships among culicine mosquitoes using a restriction map of the rDNA cistron.

Restriction maps of the rDNA cistron of twelve species of mosquitoes in six genera of the subfamily Culicinae were constructed using eight 6 bp recognition restriction enzymes. Anopheles albimanus was used as an outgroup. The size of the rDNA cistron ranged from 8.5 kb in Aedes katherinensis to 12.9 kb in Ae. polynesiensis. A total of twenty-six sites were scored; eighteen were polymorphic among ingroup taxa. The proportion of polymorphic nucleotide sites (Pnuc) was 0.059 and the heterozygosity per nucleotide site (Hnuc) was 0.028. Wagner and Fitch Parsimony, Dollo Parsimony and Nei-Li distance/neighbour-joining methods were used to construct phylogenetic trees. The rDNA RFLP dataset did not provide a well-supported phylogeny among culicine taxa. The RFLP phylogenies are incongruent with the morphology character based and molecular phylogenies and derived relationships did not correspond with current taxonomic classifications. The lack of resolution was due to homoplasy arising from frequent independent loss or gain of restriction sites among unrelated taxa.

Animals↗
PubMed1998

Relief of urinary tract obstruction in tuberculosis to improve renal function. Analysis of predictive factors.

OBJECTIVE: To assess the effect of the relief of obstruction on the ultimate function of the affected renal unit in urinary tuberculosis, and to identify predictors of functional recoverability. PATIENTS AND METHODS: Of a total of 82 patients with urinary tuberculosis presenting over 7 years, 38 with evidence of upper tract obstruction were analysed. All patients were assessed with pre-operative excretory urography, urinary mycobacterial cultures and serum chemistry. Patients with subnormally functioning kidneys were assessed with baseline renal scans. Preliminary intervention in the form of JJ stenting or percutaneous nephrostomy (PCN) was carried out in patients with reasonable renal function. Function was reassessed after 4 weeks to detect evidence of improvement and factors which could affect the outcome were determined. RESULTS: Thirty-eight patients had documented upper tract obstruction, of whom six had bilateral obstruction (total of 44 renal units). Ten renal units were not functioning at presentation, with a mean (SD) glomerular filtration rate (GFR) of 3.0 (5.73) mL/min, and no preliminary intervention was performed. In the remaining 34, preliminary intervention was carried out before definitive surgery (JJ stenting in 14, PCN in 15 and PCN followed by antegrade JJ stenting in five); 21 of these renal units were salvaged but 13 were lost despite overcoming the obstruction. Three of the 13 units deteriorated from having acceptable pre-treatment GFRs to becoming non-functional. Good renal cortical thickness, a low grade of renal involvement (Semb 1 or 2), the presence of more distal disease in the form of ureteric stricture and a GFR of > 15 mL/min were good predictors of renal recovery after diversion. CONCLUSIONS: The loss of some renal units seems inevitable in patients with urinary tuberculosis, despite advances in chemotherapy. Having pre-operative predictors of renal recovery may ensure optimal patient selection, thereby reducing the number of procedures and economic burden on the patient who does not require intervention.

Adult↗
PubMed1998

Cytokine interactions promote synergistic fibronectin accumulation by mesangial cells.

BACKGROUND: The development of glomerulosclerosis has been associated with the presence of the cytokines transforming growth factor-beta 1 (TGF-beta 1), tumor necrosis factor-alpha (TNF-alpha) and/or interleukin-1 beta (IL-1 beta), at some stage in the glomerulus. To better understand the role of these cytokines in the scarring process their effect on rat mesangial cell fibronectin production was investigated. METHODS: Mesangial cells were exposed to 10 ng/ml of either TGF-beta 1, TNF-alpha, or IL-1 beta or to TGF-beta 1 in combination with TNF-alpha or IL-1 beta. Tissue culture supernatants and cell lysates were assayed for fibronectin. Supernatants were also assayed for TGF-beta 1. Northern blot analyses probing for fibronectin, transin, TIMP-1 and TGF-beta 1 were carried out on RNA extracted from mesangial cells exposed to individual and combinations of cytokines. RESULTS: Individually these cytokines were only able to induce modest increases in fibronectin protein levels. However, when mesangial cells were exposed to TGF-beta 1 in combination with either TNF-alpha or IL-1 beta then fibronectin levels were synergistically up-regulated approximately fivefold over unstimulated levels. Northern analysis demonstrated that fibronectin mRNA levels in the combination were also synergistically increased. In contrast, rat transin gene expression in the combinations was reduced to well below levels induced by TNF-alpha and IL-1 beta individually. In addition, synergistic up-regulation of both TGF-beta 1 protein and message by the cytokine combinations was also observed. TGF-beta 1: TNF-alpha and TGF-beta 1: IL-1 beta induced additive increases in TIMP-1 (tissue inhibitor of metalloproteinases-1) mRNA levels. CONCLUSIONS: These data illustrate that complex interactions can occur between cytokines within the glomerulus modulating both matrix synthetic and degradation pathways. These could initiate the scarring process and the development of glomerulosclerosis.

Animals↗
PubMed1998

Effect of some physiological factors on nitrogenase activity and nitrogenase mediated hydrogen evolution by mixed microbial culture.

Fermentative H2 evolution, nitrogenase activity (acetylene reduction) and nitrogenase mediated H2 evolution was studied in free cells of mixed microbial population of H2 producers. At 3% glucose level, the cells produced 8.35 l H2/mol glucose utilized. The role of nitrogenase system in H2 generation was evident by derepressed nitrogenase activity (0.46 nmoles C2H4 produced/mg protein/h) under defined in vitro conditions. For maximum expression of the activity, the cells required preactivation under anaerobic conditions by incubating at 40 degrees C for 20-24 h with 0.2% glucose in the culture medium. At an O2 level of more than 0.25%, the acetylene reduction activity decreased significantly and could not be detected at a level of 20%. Nitrogenase activity development was higher at acetylene: inoculum ratio between 4.2-6.25. H2 evolution was lower when the mixed cells were incubated under an atmosphere of 10% C2H2 and 5% CO gas. This decrease in H2 evolution was also evident at 2.5-6.5 mM NaNO3 and KNO3 concentrations in the liquid culture medium thus establishing more than 50% H2 evolution through nitrogenase.

Acetylene↗
PubMed1998

Production and purification of an extracellular cellulase from Bacillus brevis VS-1.

A bacteria identified as Bacillus brevis has been isolated from the soil. It has been found to secrete cellulase extracellularly whose production increased almost five times on addition of galactose in the culture medium. Production of cellulase has been found optimal at pH 5.5, 37 degrees C and 175 rpm speed using environmental orbital shaker. The cellulase has been purified using ultrafiltration and Sephadex G-200 column chromatography. The native molecular weight of the enzyme is found to be 33,000 +/- 2000 using Sephadex G-200 gel filtration chromatography. The subunit molecular weight (33,000 +/- 2,000) indicate monomeric nature of the enzyme. The enzyme showed Michaelis Menten kinetics exhibiting Km approximately 1.7 +/- 0.1 mg/ml for CMC. The enzyme activity got inhibited by heavy metals viz. Hg+2 and Ag+2.

Bacillus↗
PubMed1998

Improvement in cell-mediated immune function during potent anti-human immunodeficiency virus therapy with ritonavir plus saquinavir.

Inhibiting human immunodeficiency virus (HIV) replication with potent antiretroviral therapy may result in improved immune function, and this may lead to favorable outcomes, independent of changes in CD4+ lymphocyte count. The effect of combination protease inhibitor therapy (ritonavir plus saquinavir) on functional measures of cell-mediated immunity in 41 HIV-infected patients from one center of a multicenter trial was investigated. After 24 weeks, median plasma virus load decreased from 4.74 log10 copies/mL to below the detection limit of the assay (2.30 log10), and mean CD4+ lymphocyte count increased from 284 cells/microL to 413 cells/microL. Proliferative responses to phytohemagglutinin developed in 21 of 34 patients in whom responses were absent at baseline. Increases were observed in interleukin-2, -12, and -10 production and in the expression of CD28 on CD8+ lymphocytes. Initiation of potent anti-HIV therapy results in a degree of immune restoration, suggesting that HIV-induced immune suppression is a dynamic and potentially reversible process.

CD28 Antigens↗
PubMed1998

Relapse of Wegener's granulomatosis in the first trimester of pregnancy: a case report.

The association of Wegener's granulomatosis and pregnancy is rare and poses unique therapeutic challenges, particularly when active disease presents in early pregnancy. We describe a 22-yr-old woman who recovered successfully from her initial episode of Wegener's granulomatosis with a standard course of treatment with prednisolone and cyclophosphamide. Two and a half years later, she presented with relapse during the first trimester of pregnancy (primigravida). Since the clinical features suggested mild disease, she was started on prednisolone at a dose of 1 mg/kg/day, to which she seemed to respond very well for 3 months. Unfortunately, she had a spontaneous abortion at 5 months of gestation while on 25 mg/day of prednisolone. At this time, her disease flared further, with clinically manifest lung disease which was not part of her initial presentation. She was treated with another course of oral cyclophosphamide and prednisolone, and a remission was achieved in 4 months. There are no agreed guidelines on the treatment of Wegener's granulomatosis during pregnancy. In this report, the therapeutic issues are discussed against the background of the available literature.

Abortion, Spontaneous↗
PubMed1998

Serum magnesium levels in protein-energy malnutrition.

Serum magnesium levels were measured by atomic absorption spectrophotometry in 46 malnourished and 12 healthy children, aged 3 months to 5 years. The nutritional status of children was classified in relation to weight for age and height for age using the Indian Academy of Pediatrics and the Waterlow classifications, respectively. NCHS data were used for the purposes of comparison. Serum magnesium levels were significantly low in children with moderate (weight for age 61-70 per cent) and severe (weight < or = 60 per cent) malnutrition, and in children with marked linear growth retardation (height for age < 85 per cent). Nearly half of the marasmic children had serum magnesium levels in the hypomagnesemic range (below 1.56 mg/dl). Serum magnesium levels had significant correlations with height for age and serum albumin.

Body Height↗