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Singh NP, Gupta AP, Sinha AK, Ahuja PS. High-performance thin layer chromatography method for quantitative determination of four major anthraquinone derivatives in Rheum emodi. J Chromatogr A 2005; 1077:202-6. [PMID: 16001557 DOI: 10.1016/j.chroma.2005.03.130] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A high-performance thin layer chromatographic (HPTLC) method for the rapid and simple quantification of the four major anthraquinone derivatives i.e. physcion, chrysophanol, emodin and chrysophanol glycoside in Rheum emodi is described. HPTLC of anthraquinone derivatives was performed on pre-coated RP-18 F254S HPTLC plates. For achieving good separation, the mobile phase of methanol-water-formic acid (80:19:1, v/v/v) was used. The densitometric determination of anthraquinone derivatives was carried out at 445 nm in reflection/absorption mode. The calibration curves were linear in the range of 20-100 ng for physcion, 80-400 ng for chrysophanol and emodin, and 200-1000 ng for chrysophanol glycoside. The method was found to be reproducible and convenient for quantitative analysis of anthraquinone derivatives in the methanolic extract of rhizomes of R. emodi collected from three different locations of Western Himalaya, India.
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Abstract
A simple, sensitive, and reliable DNA diffusion assay for quantification of apoptosis is based on the principle that nuclear DNA of apoptotic cells have abundant alkali-labile sites and under alkaline conditions small pieces of DNA thus generated diffuse in agarose, giving the appearance of a halo if stained with a sensitive fluorescent dye such as YOYO-1. The protocol for detection of apoptosis described here is tested for estimation of apoptosis in human leukocytes (mostly neutrophils) incubated at 37 degrees C for 24 h. Cells were mixed with agarose, microgels were made, and cells were lysed in a solution of high salt, detergents, and alkali. DNA was precipitated in microgels by ethanol and spermine. Staining of DNA was done with an intense fluorescent dye, YOYO-1. Apoptotic cells show a circular gradient of granular DNA with a dense central zone and a lighter and hazy outer zone, giving the overall appearance of a halo.
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Abstract
Diphtheroids or "coryneform" bacilli are usually considered to be nonpathogenic "normal flora" of human skin and mucous membranes. Because bacterial cultures are frequently contaminated with these organisms the correct diagnosis and treatment may be delayed by the failure to recognize serious infections caused by them. Few confirmed cases of orthopaedic infections due to Arcanobacterium haemolyticum infection have been reported, partly because of inadequate identification of this bacterium. We report a case of septic arthritis due to A. haemolyticum.
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Singh NP, Gupta S, Chandra J, Anuradha S, Kohli R, Rizvi SNA. Continuous ambulatory peritoneal dialysis (CRPD)--an initial Indian experience. JOURNAL OF THE INDIAN MEDICAL ASSOCIATION 2005; 103:22, 24, 26 passim. [PMID: 16008326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Continuous ambulatory peritoneal dialysis (CAPD) is a widely accepted mode of renal replacement therapy. CAPD is largely underutilised in India. Twenty patients of chronic renal failure (CRF) were started on CAPD-10 on the standard straight set, 10 on the Y-set. The efficacy of CAPD was evaluated by assessment of laboratory parameters at the onset and after three months of CAPD. Significant improvements in blood, urea, serum creatinine, serum bicarbonate, serum calcium, serum phosphorous, haemoglobin level and blood pressure were observed. There was a significant deterioration in the serum lipid and protein levels on CAPD. Peritonitis was a major complication observed. On the standard set the incidence of peritonitis was one episode per 5.92 patient months compared to one episode per 19.33 patient months with the Y-set (P value = 0.05). Peritonitis occurred more frequently in the summer months. At the end of one year, 70% patients continued on CAPD, with 3 deaths, one each due to malnutrition, myocardial infarction and tunnel infection. Three patients switched over to other replacement therapies. To conclude, CAPD can emerge as a safe, viable mode of renal replacement in developing countries like India.
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Lai H, Sasaki T, Singh NP, Messay A. Effects of artemisinin-tagged holotransferrin on cancer cells. Life Sci 2005; 76:1267-79. [PMID: 15642597 DOI: 10.1016/j.lfs.2004.08.020] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2004] [Accepted: 08/25/2004] [Indexed: 11/28/2022]
Abstract
Artemisinin reacts with iron to form free radicals that kill cells. Since cancer cells uptake relatively large amount of iron than normal cells, they are more susceptible to the toxic effect of artemisinin. In previous research, we have shown that artemisinin is more toxic to cancer cells than to normal cells. In the present research, we covalently attached artemisinin to the iron-carrying plasma glycoprotein transferrin. Transferrin is transported into cells via receptor-mediated endocytosis and cancer cells express significantly more transferrin receptors on their cell surface and endocytose more transferrin than normal cells. Thus, we hypothesize that by tagging artemisinin to transferrin, both iron and artemisinin would be transported into cancer cells in one package. Once inside a cell, iron is released and can readily react with artemisinin close by tagged to the transferrin. This would enhance the toxicity and selectivity of artemisinin towards cancer cells. In this paper, we describe a method to synthesize such a compound in which transferrin was conjugated with an analog of artemisinin artelinic acid via the N-glycoside chains on the C-domain. The resulting conjugate ('tagged-compound') was characterized by MALDI-MS, UV/Vis spectroscopy, chemiluminescence, and HPLC. We then tested the compound on a human leukemia cell line (Molt-4) and normal human lymphocytes. We found that holotransferrin-tagged artemisinin, when compared with artemisinin, was very potent and selective in killing cancer cells. Thus, this 'tagged-compound' could potentially be developed into an effective chemotherapeutic agent for cancer treatment.
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Singh NP, Prakash A, Kubba S, Ganguli A, Singh AK, Sikdar S, Agarwal SK, Dinda AK, Grover C. Psoriatic nephropathy--does an entity exist? Ren Fail 2005; 27:123-7. [PMID: 15717645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023] Open
Abstract
Psoriasis is an immune-mediated chronic inflammatory disorder of the skin. Association with kidney disease has been debated for a long time. Secondary renal amyloidosis in psoriatic arthropathy and drug-induced renal lesions secondary to methotrexate or cyclosporine are accepted accompaniments of psoriasis. IgA nephropathy is also known to occur in psoriatics. We report three interesting cases of renal involvement in long-standing established psoriasis on topical therapy alone. The patients presented with hypertension, significant proteinuria, hypoalbuminemia, and dyslipidemia. Kidney biopsies revealed "mesangioproliferative glomerulonephritis with IgA nephropathy," "focal proliferative glomerulonephritis," and "membranous glomerulonephropathy." The former two had marked active urinary sediment. Patients improved on prednisolone and angiotensin-converting enzyme inhibitors. Contrary to the belief that renal involvement in psoriasis is coincidental, we propose that kidney disease may be a common accompaniment of psoriasis, which may be labeled as "psoriatic nephropathy" or "psoriatic kidney disease." The exact mechanism of this entity is yet to be elucidated.
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Trisini AT, Singh NP, Duty SM, Hauser R. Relationship between human semen parameters and deoxyribonucleic acid damage assessed by the neutral comet assay. Fertil Steril 2004; 82:1623-32. [PMID: 15589869 DOI: 10.1016/j.fertnstert.2004.05.087] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2004] [Revised: 05/05/2004] [Accepted: 05/05/2004] [Indexed: 10/26/2022]
Abstract
OBJECTIVE To explore the association between semen parameters and sperm DNA damage. DESIGN Cross-sectional. SETTING Andrology clinic. PATIENT(S) Two hundred fifty-seven men undergoing infertility assessment. INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) Sperm concentration and motility were measured using computer-assisted sperm analysis; morphology was scored using the strict criteria. The neutral comet assay was used to measure sperm DNA damage. Comet assay parameters included comet extent, percent DNA in the comet tail, and tail distributed moment, an integrated measure of length and intensity. We also scored cells that were too long to measure (>300 microm), which we referred to as cells with high DNA damage. RESULT(S) Men older than 35 years had a statistically significant increase in the number of cells with high DNA damage as compared with younger men. In age-adjusted regression analyses, the most consistent associations were found between semen parameters and the number of cells with high DNA damage. For an interquartile range change in the number of cells with high DNA damage, sperm concentration declined 14.2 x 10(6)/mL, motility declined 4.3%, and morphology declined 0.5%. Comet extent and percent DNA in the comet tail were also associated with a decline in sperm concentration and motility, respectively. CONCLUSION(S) Although there were associations between semen and comet assay parameters, their magnitudes were weak, suggesting that the comet assay provides additional independent information on sperm function.
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Goyal R, Singh NP, Manchanda V, Mathur M. Detection of clindamycin susceptibility in macrolide resistant phenotypes of Staphylococcus aureus. Indian J Med Microbiol 2004; 22:251-4. [PMID: 17642749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The present study aimed at in vitro detection of macrolide resistant phenotypes of methicillin resistant Staphylococcus aureus (MRSA) and interpretation of susceptibility tests to guide therapy. The study included 25 MRSA strains that were resistant to erythromycin and clindamycin, 25 MRSA strains that were sensitive to both erythromycin and clindamycin and 100 MRSA isolates which displayed erythromycin resistant but clindamycin susceptible phenotype. Erythromycin and clindamycin double disc susceptibility testing was done to detect inducible clindamycin resistance. Dilution susceptibility testing for clindamycin and erythromycin alone and in combination was performed for all 150 strains. Seventy-six strains showed blunting around clindamycin disc (inducible resistance). After induction with erythromycin, minimum inhibitory concentration (MIC) of clindamycin was noticed to rise from at least 16 to 256 g/mL in iMLSB phenotypes indicating inducible resistance. The detailed result analysis suggests the possible role of clindamycin in treatment of some of the erythromycin resistant isolates (non inducible), as there are multiplicity of resistance mechanisms and diversity of phenotypic expressions.
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Meeker JD, Singh NP, Ryan L, Duty SM, Barr DB, Herrick RF, Bennett DH, Hauser R. Urinary levels of insecticide metabolites and DNA damage in human sperm. Hum Reprod 2004; 19:2573-80. [PMID: 15333606 DOI: 10.1093/humrep/deh444] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Members of the general population are exposed to non-persistent insecticides at low levels. The present study explored whether environmental exposures to carbaryl and chlorpyrifos are associated with DNA damage in human sperm. METHODS Subjects (n=260) were recruited through a Massachusetts infertility clinic. Individual exposures were measured as spot urinary metabolite concentrations of chlorpyrifos [3,5,6-trichloro-2-pyridinol (TCPY)] and carbaryl [1-naphthol (1N)], adjusted using specific gravity. Sperm DNA integrity was assessed by neutral comet assay and reported as comet extent, percentage DNA in comet tail (Tail%) and tail distributed moment (TDM). RESULTS A statistically significant increase in Tail% was found for an interquartile range (IQR) increase in both 1N [coefficient=4.1; 95% confidence interval (CI) 1.9-6.3] and TCPY (2.8; 0.9-4.6), while a decrease in TDM was associated with IQR changes in 1N (-2.2; -4.9 to 0.5) and TCPY (-2.5; -4.7 to -0.2). A negative correlation between Tail% and TDM was present only when stratified by comet extent, suggesting that Tail% and TDM may measure different types of DNA damage within comet extent strata. CONCLUSIONS Environmental exposure to carbaryl and chlorpyrifos may be associated with increased DNA damage in human sperm, as indicated by a change in comet assay parameters.
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Singh NP, Lai HC. Artemisinin induces apoptosis in human cancer cells. Anticancer Res 2004; 24:2277-80. [PMID: 15330172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
BACKGROUND Artemisinin is a chemical compound extracted from the wormwood plant, Artemisia annua L. It has been shown to selectively kill cancer cells in vitro and retard the growth of implanted fibrosarcoma tumors in rats. In the present research, we investigated its mechanism of cytotoxicity to cancer cells. MATERIALS AND METHODS Molt-4 cells, in complete RPMI-1640 medium, were first incubated with 12 microM of human holotransferrin at 37 degrees C in a humid atmosphere of 5% CO2 for one hour. This enhanced the iron supply to the cells. The cells were then pelleted and transferred to a complete RPMI-1640 containing 200 microM of an analog dihydroartemisinin (DHA) and incubation was started (0 h). In addition, some culture samples were treated with holotransferrin alone and some (controls) were assayed without neither holotransferrin nor DHA treatment. Cells were counted and DNA diffusion assay was used to evaluate apoptosis and necrosis in each sample at 0 h and at 1, 2, 4 and 8 h of incubation. RESULTS DHA treatment significantly decreased cell counts and increased the proportion of apoptosis in cancer cells compared to controls (chi2=4.5, df=1, p<0.035). Addition of holotransferrin significantly further decreased cell counts (chi2=4.5, df=1, p<0.035) and increased apoptosis (chi2=4.5, df=1, p<0.035). No necrotic cells were observed. CONCLUSION This rapid induction of apoptosis in cancer cells after treatment with DHA indicates that artemisinin and its analogs may be inexpensive and effective cancer agents.
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Lai H, Singh NP. Magnetic-field-induced DNA strand breaks in brain cells of the rat. ENVIRONMENTAL HEALTH PERSPECTIVES 2004; 112:687-94. [PMID: 15121512 PMCID: PMC1241963 DOI: 10.1289/ehp.6355] [Citation(s) in RCA: 177] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In previous research, we found that rats acutely (2 hr) exposed to a 60-Hz sinusoidal magnetic field at intensities of 0.1-0.5 millitesla (mT) showed increases in DNA single- and double-strand breaks in their brain cells. Further research showed that these effects could be blocked by pretreating the rats with the free radical scavengers melatonin and N-tert-butyl-alpha-phenylnitrone, suggesting the involvement of free radicals. In the present study, effects of magnetic field exposure on brain cell DNA in the rat were further investigated. Exposure to a 60-Hz magnetic field at 0.01 mT for 24 hr caused a significant increase in DNA single- and double-strand breaks. Prolonging the exposure to 48 hr caused a larger increase. This indicates that the effect is cumulative. In addition, treatment with Trolox (a vitamin E analog) or 7-nitroindazole (a nitric oxide synthase inhibitor) blocked magnetic-field-induced DNA strand breaks. These data further support a role of free radicals on the effects of magnetic fields. Treatment with the iron chelator deferiprone also blocked the effects of magnetic fields on brain cell DNA, suggesting the involvement of iron. Acute magnetic field exposure increased apoptosis and necrosis of brain cells in the rat. We hypothesize that exposure to a 60-Hz magnetic field initiates an iron-mediated process (e.g., the Fenton reaction) that increases free radical formation in brain cells, leading to DNA strand breaks and cell death. This hypothesis could have an important implication for the possible health effects associated with exposure to extremely low-frequency magnetic fields in the public and occupational environments.
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Athavale A, Souza GAD, Avasthi R, Singh NP, Kale M, Taneja A, Sireesha K. A clinical trial of the efficacy and safety of montelukast as monotherapy in patients with chronic stable bronchial asthma. JOURNAL OF THE INDIAN MEDICAL ASSOCIATION 2004; 102:109-11. [PMID: 15200214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
This study is aimed to evaluate the efficacy and safety of montelukast, as monotherapy, in the treatment of chronic stable bronchial asthma in adults. This was a multicentre, open label, non-comparative, prospective, 4-week study. Eligible patients discontinued all anti-inflammatory medication (steroids, chromoglycate sodium) 2 weeks prior to starting therapy with montelukast (10 mg daily). The primary efficacy criteria were improvements in forced expiratory volume in one second (FEV1), peak exploratory flow rate (PEFR) after 4 weeks of therapy. Secondary efficacy criteria were improvement in the patients' symptoms (assessed on an ordinal scale), decrease in discomfort levels (scored on a scale of 0-100), change in peripheral eosinophil counts, decrease in total daily dose of inhaled beta2 agonist (salbutamol). A total of 148 patients, mean age (+/- SD) 40.21 +/- 13.70 years, were enrolled into the study. At the end of the study there were significant improvements in FEV1 and PEFR (29% and 28% increase respectively from baseline values, p<0.000001). The mean total daily dose of inhaled salbutamol decreased significantly from prestudy values of 461 +/- 332 microg/day to 161 +/- 207 microg/day (p<0.000001). The mean eosinophil counts fell from 5.80 +/- 4.90% (+/- SD) to 4.84 +/- 4.42% (+/- SD) (p=0.02). Symptom scores improved significantly as did subjective assessment of discomfort. A total of 29 (19.6%) adverse events were reported, all of which were of mild to moderate intensity. Monotherapy with montelukast significantly improved parameters of asthma control. It was well tolerated with no reports of serious or severe adverse events.
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Singh NP, Guo L, Que X, Shirwan H. Blockade of indirect recognition mediated by CD4+ T cells leads to prolonged cardiac xenograft survival. Xenotransplantation 2004; 11:33-42. [PMID: 14962291 DOI: 10.1111/j.1399-3089.2004.00079.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The T-cell response to xenografts is induced by direct and indirect recognition of xenoantigens. Although the importance of indirect recognition is well established in vitro, the contribution of this pathway to xenograft rejection in vivo remains to be fully elucidated. We herein investigated the direct contribution of indirect recognition to cardiac xenograft rejection in the rat-to-mouse (PVG.R8-to-C57BL/10) concordant model. Rat xenoantigens invoked a vigorous proliferative response in mouse T cells harvested from naïve or graft recipients at rejection. Indirect recognition predominated the response, as antibodies against mouse class II I-A(b), CD80, or CD86 molecules significantly (45 to 60%) blocked the proliferative response. Importantly, the blockade of indirect recognition in vivo by treating the graft recipients with a monoclonal antibody (mAb) against class II I-A(b) molecule on days 0, 1, and 3 post-transplantation resulted in significant (P < 0.009) prolongation of cardiac xenograft survival (Mean Survival Time (MST) >94 +/- 55 days vs. 7 +/- 0.8 days for controls). In contrast, treatment of recipients with a mAb against mouse class I H-2K(b)/D(b) molecules did not significantly affect graft rejection (MST = 8 +/- 1 days). These results demonstrate that indirect recognition mediated by CD4(+) T cells plays a critical role in the rejection of cardiac grafts in the rat-to-mouse xenogeneic model.
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Abstract
OBJECTIVE This study was designed to explore the relationship between men's age and DNA damage and apoptosis in human spermatozoa. DESIGN Semen samples were collected from men between the ages of 20 and 57 years. Sperm DNA double-strand breaks were assessed using the neutral microgel electrophoresis (comet) assay, and apoptosis was estimated using the DNA diffusion assay. SETTING Academic medical center. PATIENT(S) Sixty-six men aged 20 to 57 years were recruited from infertility laboratory and general populations and consented to donate a semen sample. Recruitment was determined by time and day of analysis; the only exclusions were for azoospermia, prostatitis, or prior cancer therapy. INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) DNA damage and apoptosis in human sperm. RESULT(S) Age correlated with an increasing percentage of sperm with highly damaged DNA (range: 0-83%) and tended to inversely correlate with percentage of apoptotic sperm (range: 0.3%-23%). For example, percentage of sperm with highly damaged DNA, comet extent, DNA break number, and other comet measures was statistically significantly higher in men aged 36-57 years than in those aged 20-35 years, but percentage apoptosis was statistically significantly lower in the older group. Semen analysis showed percentage motility to be significantly higher in younger age groups. CONCLUSION(S) This study clearly demonstrates an increase in sperm double-stranded DNA breaks with age. Our findings also suggest for the first time an age-related decrease in human sperm apoptosis. These novel findings may indicate deterioration of healthy sperm cell selection process with age.
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Hauser R, Singh NP, Chen Z, Pothier L, Altshul L. Lack of an association between environmental exposure to polychlorinated biphenyls and p,p'-DDE and DNA damage in human sperm measured using the neutral comet assay. Hum Reprod 2003; 18:2525-33. [PMID: 14645167 DOI: 10.1093/humrep/deg508] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Chlorinated organic chemicals, such as polychlorinated biphenyls (PCB), hexachlorobenzene (HCB), dichlorodiphenyl trichloroethane (DDT), and dichlorodiphenyl dichloroethene (DDE, the most stable daughter compound of DDT) are persistent lipophilic compounds found in a large portion of the general population. To explore the hypothesis that environmental exposure to these compounds is associated with altered DNA integrity in human sperm, a study of 212 male partners of a sub-fertile couple who presented to the Massachusetts General Hospital Andrology Laboratory was conducted. METHODS The neutral single cell microgel electrophoresis assay (comet assay) was used to assess DNA integrity in sperm. VisComet image analysis software was used to measure total comet length, the proportion of DNA present in the comet tail, and tail distributed moment, an integrated measure of length and intensity. RESULTS In the regression analyses, there were no statistically significant consistent associations between the comet assay parameters and any of the individual PCB congeners, sum of PCB, or p,p'-DDE. CONCLUSION These results suggest that there are not strong relationships between adult levels of these chlorinated organic compounds and sperm DNA damage as measured by the comet assay.
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Goyal JL, Singh NP, Bhatia A. Evaluation of visual functions in patients on ethambutol therapy for tuberculosis: a prospective study. THE JOURNAL OF COMMUNICABLE DISEASES 2003; 35:230-43. [PMID: 15909750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
UNLABELLED To study the incidence of clinical and subclinical optic nerve toxicity with ethambutol therapy in patients with tuberculosis and to evaluate the reversibility of its side effects after cessation of therapy. This prospective randomized controlled study included 60 newly diagnosed adult cases of tuberculosis, who were randomly assigned into two groups. The study group included 30 patients (60eyes) who received ethambutol as a part of their anti-tubercular treatment and the control group included 30 patients (60eyes) who did not receive ethambutol. The patients were examined on monthly basis. The visual parameters studied were best corrected visual acuity, pupillary reactions, optic disc changes, color vision, contrast sensitivity, pupil cycle time, visual field charting and visual evoked potential. Ethambutol was stopped in those patients in whom toxicity was detected and they were followed more frequently. Only one patient (3.3%) showed decrease in visual acuity, three patients (10%) developed visual field defects, two patients (6.7%) showed deterioration of contrast sensitivity, the pupil cycle time was prolonged in one eye and two patients (6.7%) showed abnormal visual evoked potential. During the therapy, all patients in the study group had normal pupillary reactions, fundus picture and color vision. CONCLUSIONS Ethambutol induced ocular toxicity was seen in three patients (10%) in our study. The maximum visual recovery occurred in first six to eight weeks after stopping ethambutol. The visual recovery was complete in only one patient, but it was partial in two patients i.e. visual fields, contrast sensitivity and visual evoked potential remained abnormal.
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Singh NP, Ganguli A, Prakash A. Drug-induced kidney diseases. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 2003; 51:970-9. [PMID: 14719587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
Drug-induced kidney disease constitutes an important cause of acute renal failure and chronic kidney disease in present day clinical practice. Different classes of drugs, by virtue of immunological mechanisms or direct toxicity initiate certain stereotyped renal responses. For most patients suffering from drug-induced nephropathy common risk factors which precipitate the adverse effects include: old age, volume -depleted state, pre-existing renal dysfunction and coexisting use of other nephrotoxins. Although it is impossible to present all the drugs causing renal disease, a few prototype drugs are mentioned. In a case of undiagnosed renal disease a possibility of drug-induced renal failure should be kept as the prompt removal of the drug and supportive management can reverse the renal dysfunction to a large extent.
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Singh NP, Prakash A, Garg D, Makhija A, Pathania A, Prakash N, Kubba S, Agarwal SK. Aplastic anemia complicating systemic lupus erythematosus: successful management with cyclosporine. Rheumatol Int 2003; 24:40-2. [PMID: 13680150 DOI: 10.1007/s00296-003-0318-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2002] [Accepted: 02/12/2003] [Indexed: 10/26/2022]
Abstract
Anemia is common with connective tissue disorders, but pancytopenia is rare. We report a 22-year-old female who presented with menorrhagia, seizures, anemia, leukocytosis, thrombocytopenia, pericardial effusion, positive ANA, and evidence of vasculitis on CT head scan and was diagnosed with systemic lupus erythematosus (SLE). After 7 months of remission, she was readmitted with menorrhagia and pancytopenia. Investigations revealed aplastic anemia. She survived on transfusion support for 6 weeks, during which period she received methylprednisolone and cyclophosphamide pulses, and phenytoin was omitted but to no avail. Cyclosporine (300 mg/day) was started and the aplastic anemia responded. After 4 months of therapy, the cyclosporine was gradually tapered over the next 2 months. The patient has been on 10 mg/day of prednisolone for the last 6 months. Aplastic anemia is rare in SLE and the response to immunosuppressants is variable, but here is a success story.
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Singh NP, Yolcu ES, Taylor DD, Gercel-Taylor C, Metzinger DS, Dreisbach SK, Shirwan H. A novel approach to cancer immunotherapy: tumor cells decorated with CD80 generate effective antitumor immunity. Cancer Res 2003; 63:4067-73. [PMID: 12874008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
Abstract
Malignant cells often elude the immune system by lacking costimulatory signals required for the generation of effective antitumor immunity. Immunization with tumor cells genetically modified to express costimulatory molecules is a highly promising approach to cancer immunotherapy. However, genetic modification of tumor cells is not only labor/time intensive but is also less efficient and bears safety concerns. To override these complications, we have recently developed a novel technology that allows for efficient and durable display of exogenous proteins on the surface of a cell within 2 h. This technology involves modification of the cell membrane with a biotin derivative and decoration of biotinylated cells with proteins chimeric with core streptavidin. A chimeric molecule composed of the extracellular domains of the human CD80 costimulatory molecule and core streptavidin (CD80-SA) was efficiently displayed on the cell surface, where it persisted with a t(1/2) of >10 days in vivo. Tumors from patients with advanced stage gynecologic cancers decorated with CD80-SA elicited potent ex vivo tumor-specific proliferative and cytotoxic responses in autologous lymphocytes. Immunization with tumor cells decorated with CD80-SA completely prevented tumor growth in an aggressive model of mouse lymphoma. This technology may serve as a fast, efficient, and safe alternative to gene transfer approaches for engineering tumor cells for use in immunotherapy and research.
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Duty SM, Singh NP, Silva MJ, Barr DB, Brock JW, Ryan L, Herrick RF, Christiani DC, Hauser R. The relationship between environmental exposures to phthalates and DNA damage in human sperm using the neutral comet assay. ENVIRONMENTAL HEALTH PERSPECTIVES 2003; 111:1164-9. [PMID: 12842768 PMCID: PMC1241569 DOI: 10.1289/ehp.5756] [Citation(s) in RCA: 152] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Phthalates are industrial chemicals widely used in many commercial applications. The general population is exposed to phthalates through consumer products as well as through diet and medical treatments. To determine whether environmental levels of phthalates are associated with altered DNA integrity in human sperm, we selected a population without identified sources of exposure to phthalates. One hundred sixty-eight subjects recruited from the Massachusetts General Hospital Andrology Laboratory provided a semen and a urine sample. Eight phthalate metabolites were measured in urine by using high-performance liquid chromatography and tandem mass spectrometry; data were corrected for urine dilution by adjusting for specific gravity. The neutral single-cell microgel electrophoresis assay (comet assay) was used to measure DNA integrity in sperm. VisComet image analysis software was used to measure comet extent, a measure of total comet length (micrometers); percent DNA in tail (tail%), a measure of the proportion of total DNA present in the comet tail; and tail distributed moment (TDM), an integrated measure of length and intensity (micrometers). For an interquartile range increase in specific gravity-adjusted monoethyl phthalate (MEP) level, the comet extent increased significantly by 3.6 micro m [95% confidence interval (95% CI), 0.74-6.47]; the TDM also increased 1.2 micro m (95% CI, -0.05 to 2.38) but was of borderline significance. Monobutyl, monobenzyl, monomethyl, and mono-2-ethylhexyl phthalates were not significantly associated with comet assay parameters. In conclusion, this study represents the first human data to demonstrate that urinary MEP, at environmental levels, is associated with increased DNA damage in sperm.
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Singh NP, Bansal R, Thakur A, Kohli R, Bansal RC, Agarwal SK. Effect of membrane composition on cytokine production and clinical symptoms during hemodialysis: a crossover study. Ren Fail 2003; 25:419-30. [PMID: 12803505 DOI: 10.1081/jdi-120021154] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Intradialytic symptoms including hypotension have been reported during dialysis and it has been suggested that these are related to the release of cytokines like IL-1beta and TNFalpha by blood mononuclear cells when they get activated either due to contact with the dialyzer membrane or by compliment activation. OBJECTIVE To study the relationship between hemodialysis symptoms, cytokine production, and dialyzer membrane composition. METHOD In a randomized prospective crossover study, 20 ESRD patients on maintenance hemodialysis were studied over cuprophan (CU) and polysulfone (PS) low flux dialyzer membranes for three weeks each undergoing a biweekly dialysis schedule of 4 h sessions. Serial IL-1beta and TNFalpha levels were measured over 0, 15, 240 min during the first use of the dialyzer for all patients on both membranes. Intradialytic symptoms were monitored in a total of 240 dialysis sessions. RESULTS IL-1beta levels increased from 16.6 +/- 2.2 to 64.8 +/- 25.1 pg/mL on CU and 21.5 +/- 3.7 to 103.5 +/- 30.7 pg/mL on PS membrane over the 4-h dialysis session. Similarly TNFalpha increased from 42.8 +/- 4.5 to 354.9 +/- 80.4 pg/mL on CU and 117.1+/- 53.7 to 387.0 +/- 78.0 pg/mL on PS membrane. IL-1beta levels increased significantly with PS membrane while TNFalpha rise was significant with both the membranes. Nausea was the most common symptom occurring in 138 dialysis sessions (57.5%). Vomiting, chest pain, fever, chills, and breathlessness occurred significantly more during dialysis with CU membrane as compared with PS membrane (P < 0.01). Nausea, cramps, back pain, itching, restlessness, post dialysis fatigue, and hypotension did not differ between the two membranes. The mean rise in the cytokine levels during the first 15 min of sessions where the symptoms occurred, when compared with the mean rise in sessions where the symptoms did not occur, did not reveal any significant difference. Cytokine release did not correlate with the occurrence of intradialytic symptoms. CONCLUSION Both CU and PS membranes increase circulating cytokine levels. More intradialytic clinical symptoms are seen in dialysis with CU as compared with PS membrane but the rise in cytokines IL-1beta and TNFalpha does not appear to be responsible for them.
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Singh NP, Prakash A, Makhija A, Garg D, Pathania A, Agarwal SK. Staphylococcal pericarditis in a chronic renal failure patient. Ren Fail 2003; 25:493-8. [PMID: 12803514 DOI: 10.1081/jdi-120021811] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
A 34-year-old female with end-stage renal disease was admitted for severe metabolic acidosis, uremic encephalopathy, pericarditis and severe anemia following a bout of acute gastroenteritis. She improved on aggressive medical management including intensive hemodialysis and was initiated onto maintenance heparin-free hemodialysis (twelve hours per week) and discharged. After a week, she presented with fever with chills and rigors for three days, was toxic, severely orthopenic and had a pulsus paradoxus of 36 mmHg. Echocardiography suggested cardiac tamponade. Aspiration revealed frank pus with polymorphonuclear predominance and Staphylococcus aureus on culture. CT of the thorax revealed pericardial effusion. In the absence of any obvious septic foci, concomitant pleuro-pulmonary sepsis, mediastinal or intra-abdominal pathology; a diagnosis of "acute primary purulent pericarditis" was made. Patient was put on parenteral antibiotics-ceftriaxone and metrogyl. Vancomycin was added after sensitivity results. Pericardial drainage was required initially. After toxemia improved, paradox decreased and fever subsided, the pericardial catheter was removed and antibiotics continued for a period of four weeks. Maintenance hemodialysis was continued during hospital stay and after discharge.
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Prakash A, Singh NP, Makhija A, Garg D, Kubba S, Agarwal SK. Mediastinitis presenting as pyrexia of unknown origin. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 2003; 51:405-7. [PMID: 12723660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
A 55 year old female was admitted as a case of pyrexia of unknown origin (PUO) of 2 months duration. She had developed throat ache, progressive dysphagia for both solids and liquids, dry cough and retrosternal pain for one week. Examination revealed fever, tachycardia, tachypnoea and a soft tissue warm tender, erythematous, non-fluctuant swelling in lower anterior neck with chest findings suggestive of bilateral pleural effusion. Plain X-rays of the neck and chest strengthened the clinical suspicion of cellulitis of lower neck with bilateral pleural effusion. CT scan confirmed the radiologic findings and also revealed pericardial effusion and thickening; small mediastinal lymphadenopathy and mediastinitis. Patient responded to parenteral antibiotics (ceftriaxone and metronidazole) and hydrocortisone with complete resolution in 10 days.
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Prakash A, Singh NP, Agarwal SK, Prakash N. Plummer's nails. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 2003; 51:382. [PMID: 12723653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
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Singh NP, Guo L, Mhoyan A, Shirwan H. Predominant expression of Th2 cytokines and interferon-gamma in xenogeneic cardiac grafts undergoing acute vascular rejection. Transplantation 2003; 75:586-90. [PMID: 12640294 DOI: 10.1097/01.tp.0000052594.83318.68] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The Th1 response has been shown to play a role in acute allograft rejection, whereas the Th2 response has been implicated in the protection of allografts. Unlike allografts, the pattern of cytokines in response to solid-organ xenografts has been the subject of limited studies. We investigated intragraft cytokine expression in a concordant cardiac xenograft model (rat-to-mouse) to test if a particular cytokine profile predominates. METHODS Intra-abdominal cardiac transplantation was performed using C57BL/10 mice as recipients of PVG.R8 rat hearts. Syngeneic grafts (C57BL/10-to-C75BL/10) served as controls. Cardiac grafts harvested on various days posttransplantation were analyzed for histology and intragraft cytokine expression using reverse-transcriptase polymerase chain reaction. RESULTS The grafts in this model were rejected with a mean survival time of 7+/-1 days and showed extensive evidence of acute vascular rejection, consisting of global distortion of myocardial architecture, fewer cellular infiltrates, interstitial hemorrhage with myocyte necrosis thrombosis, and vasculitis with neutrophils and lymphocytes infiltrating vessel walls. Cardiac xenografts predominantly expressed Th2 cytokines, interleukin (IL)-4, IL-10, and transforming growth factor-beta with various kinetics. IL-10 was detectable on day 1 and reached its peak level of expression on day 6 posttransplantation. IL-4 showed minimal and undetectable expression on days 1 and 3 and significant expression on day 6 posttransplantation. Transforming growth factor-beta was expressed moderately on all days examined. The expression of interferon (IFN)-gamma, a Th1 cytokine, was specific to xenografts and showed a gradual increase from days 3 to 6 posttransplantation. In marked contrast, IL-2 showed complete lack of expression. CONCLUSIONS Our data demonstrate predominant expression of Th2 cytokines and IFN-gamma in cardiac xenografts undergoing acute vascular rejection. The Th2 cytokines may promote acute vascular rejection by regulating the humoral response, and IFN-gamma may delay, but not prevent, this response.
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Singh NP, Kumari V, Chauhan D. Mosquito larvicidal properties of the leaf extract of a herbaceous plant, Ocimum canum (Family: Labiatae). THE JOURNAL OF COMMUNICABLE DISEASES 2003; 35:43-5. [PMID: 15239305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
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Singh NP, Mandal SK, Thakur A, Kapoor D, Anuradha S, Prakash A, Kohli R, Agarwal SK. Efficacy of GM-CSF as an adjuvant to hepatitis B vaccination in patients with chronic renal failure--results of a prospective, randomized trial. Ren Fail 2003; 25:255-66. [PMID: 12739832 DOI: 10.1081/jdi-120018726] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Chronic renal failure patients on hemodialysis are at an increased risk of acquiring hepatitis B infection. Hence vaccination against hepatitis B assumes great importance in these patients. However, the response to hepatitis B vaccination is poor, even when 4 double doses (40 microg) of the vaccine are given. This study was conducted to determine the efficacy of GM-CSF as an adjuvant to hepatitis B vaccine in CRF patients. METHODS CRF patients including both hemodialysis (HD) and non-dialysis (ND) patients were randomized to receive either placebo or a single injection of GM-CSF (in varying doses of 50 microg, 100 microg, 150 microg) a day prior to the 1st dose of recombinant hepatitis B vaccine (40 microg). Three more doses of the vaccine were given at 1, 2, and 6 months. The anti-HBs antibody titres were measured by ELISA at 3 and 7 months. Patients having antibody titres less than 10 IU/L were considered non-responders. The response rate and mean antibody titers were compared between the control (I) and GM-CSF (II) groups. RESULTS In group I, 31 and 27 patients were available for evaluation at 3 and 7 months respectively. In group II, 33 and 28 patients could be evaluated at the same time points. Within the control group (group I), the response rate in hemodialysis patients (63.6%) was lower as compared to non-dialysis patients (81.2%). The response rate in group II was higher than that in group I at both 3 months as well as 7 months (78.1% vs. 62.3% and 89.3% vs. 74.1%, p = ns). The best response rates in group II were observed when GM-CSF was used in a dose of 150 microg (90.9% at 3 months and 100% at 7 months). The mean antibody titers were also found to be higher in the group II as compared to group I (409.6 vs. 243.9 IU/L, p = 0.01). CONCLUSION The results of this randomized, prospective study suggest that: 1. Patients with chronic renal failure should be vaccinated for hepatitis B as chronic renal insufficiency is established. 2. GM-CSF is an effective adjuvant to hepatitis B vaccine in these patients especially when a priming dose of 150 microg is used prior to 1st dose of hepatitis B vaccination.
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Singh NP, Arora SK, Gupta A, Anuradha S, Sridhara G, Agarwal SK, Gulati P. Stroke: a rare presentation of cardiac hydatidosis. Neurol India 2003; 51:120-1. [PMID: 12865545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
Abstract
A 13-year-old boy presented with acute stroke leading to right-sided hemiparesis. A contrast CT scan of the brain showed a hemorrhagic infarct in the left basal ganglia region with surrounding edema. Echocardiography showed a hydatid cyst in the right atrial chamber extending into the left atrium. A single hepatic hydatid was also seen.
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Singh NP, Goyal R, Manchanda V, Gupta P. Disseminated nocardiosis in an immunocompetent child. ANNALS OF TROPICAL PAEDIATRICS 2003; 23:75-8. [PMID: 12648329 DOI: 10.1179/000349803125002904] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
We report a 2-month-old child with a disseminated Nocardia farcinica infection that presented with suppurative lymphatic abscess. The child did not have any predisposing factors and responded to treatment with co-trimoxazole and amikacin. This is first case report of disseminated nocardiosis caused by Nocardia farcinica in an immunocompetent child.
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Singh NP, Goyal R, Manchanda V, Das S, Kaur I, Talwar V. Changing trends in bacteriology of burns in the burns unit, Delhi, India. Burns 2003; 29:129-32. [PMID: 12615458 DOI: 10.1016/s0305-4179(02)00249-8] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A retrospective study of bacterial isolates from the wounds of patients admitted to burns unit, was undertaken at Guru Tegh Bahadur Hospital, University College of Medical Sciences, Delhi, India, over a period of 5 years between July 1997 and April 2002. The study compared the results obtained with the previous 5 years data (June 1993-June 1997) from the same unit to determine the changing patterns and emerging trends of bacterial isolates and their antimicrobial susceptibilities. Pseudomonas species (31%) and Staphylococcus aureus (22%) were the most common pathogens followed by Klebsiella species (19%). Multi-drug resistant (MDR) Acinetobacter species (9%) have emerged as an important nosocomial pathogen in our burn unit. Most of the gram-negative isolates obtained were found to be multi-drug resistant and 61% of the tested isolates were extended spectrum beta-lactamase (ESBL) producers. Concomitant resistance to penicillin and aminoglycosides was observed in 61% of Enterococcus fecalis isolates. When compared with the results of previous 5 years (June 1993-June 1997) Pseudomonas spp. was still the commonest pathogen in the burns unit. However, isolation of this organism and other gram-negative organisms has decreased in comparison to previous years. The incidence of antimicrobial resistance has markedly increased over the past years resulting in limitation of therapeutic options.
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Manchanda V, Singh NP. Occurrence and detection of AmpC beta-lactamases among Gram-negative clinical isolates using a modified three-dimensional test at Guru Tegh Bahadur Hospital, Delhi, India. J Antimicrob Chemother 2003; 51:415-8. [PMID: 12562713 DOI: 10.1093/jac/dkg098] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AmpC enzymes can be differentiated from other extended-spectrum beta-lactamases by their ability to hydrolyse cephamycins as well as other extended-spectrum cephalosporins. The present study was designed to determine the occurrence of AmpC enzyme-harbouring Gram-negative clinical isolates in a tertiary care hospital in Delhi, India. Among the 135 clinical isolates of Gram-negative bacilli tested, 20.7% were found to harbour AmpC enzymes using a modified three-dimensional test. Inhibition of zone distortion in the presence of cloxacillin confirmed AmpC-harbouring isolates. Maximal incidence of AmpC producers was found among Acinetobacter spp. (42.8%) followed by Klebsiella pneumoniae isolates (33.3%). No AmpC-harbouring isolates revealed decreased susceptibility to cefoxitin. Therefore, Gram-negative bacilli showing resistance to any cephalosporin or aztreonam irrespective of cefoxitin susceptibility should be screened for the AmpC enzyme. The modified three-dimensional test is easy to carry out and can be applied as a phenotypic screening method for detection of AmpC-harbouring Gram-negative organisms. This is the first study to determine the occurrence of AmpC beta-lactamases from India.
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Antao B, Rowlands TE, Singh NP, McCleary AJ. Pelviureteric junction disruption as a complication of chemical lumbar sympathectomy. CARDIOVASCULAR SURGERY (LONDON, ENGLAND) 2003; 11:42-4. [PMID: 12543571 DOI: 10.1016/s0967-2109(02)00122-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Chemical lumbar sympathectomy is a commonly performed procedure in vascular surgery and pain management. This case report discusses the management of a patient who suffered pelviureteric junction disruption following phenol injection for ischaemic leg pain despite radiological evidence of correct placement. The authors suspect this is an underreported complication, which could be relevant in obtaining informed consent.
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Yolcu ES, Askenasy N, Singh NP, Cherradi SEL, Shirwan H. Cell membrane modification for rapid display of proteins as a novel means of immunomodulation: FasL-decorated cells prevent islet graft rejection. Immunity 2002; 17:795-808. [PMID: 12479825 DOI: 10.1016/s1074-7613(02)00482-x] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Long-term display of exogenous proteins on the cell surface may have important research and therapeutic implications. We report a novel method for the cell-surface display of proteins that involves generation of a chimeric protein with core streptavidin, biotinylation of cells, and "decoration" with the protein. A chimeric protein with the extracellular portions of FasL (SA-FasL) was efficiently displayed on the cell surface within 2 hr without detectable cellular toxicity. Biotin and SA-FasL persisted on the cell surface for weeks in vitro and in vivo. Immunomodulation with SA-FasL-decorated splenocytes effectively blocked alloreactive responses in naive and presensitized rodents and prevented the rejection of allogeneic pancreatic islets. This approach may serve as an alternative to gene transfer-based expression with broad research and therapeutic applications.
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Singh NP, Penn PE, Pendergrass WR, Wolf NS. White light-mediated DNA strand breaks in lens epithelial cells. Exp Eye Res 2002; 75:555-60. [PMID: 12457867 DOI: 10.1006/exer.2002.2046] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It was hypothesized that white light can induce DNA single-strand breaks/alkali labile sites in lens epithelial cells during the dissection process when lenses are being collected for study. Dissection of lenses in white light significantly increased 'Integrated Intensity' (P=0.0216), an index of DNA single strand breaks/alkali labile sites, using the alkaline microgel electrophoresis assay. In addition, we investigated the DNA damaging effect of visible light in a human lymphocyte model in which cells were exposed to white light, red light or minimal indirect light for 5 min. Results of these experiments confirm our conclusion that visible light induces DNA damage in cells. These findings may be relevant in a genotoxicity study on cells ex vivo.
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Singh NP, Anuradha S, Agarwal SK. Current recommendations on iron therapy in anaemia of chronic renal failure. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 2002; 50:1295-302. [PMID: 12568217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
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Singh NP, Muller CH, Berger RE. DNA double strand breaks and apoptosis in human sperm: effects of donor age. Fertil Steril 2002. [DOI: 10.1016/s0015-0282(02)03562-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Anuradha S, Agarwal SK, Singh NP, Gupta A, Chowdhury V. An unusual presentation of the Papillon-Lefevre syndrome as recurrent liver abscesses. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 2002; 50:974-6. [PMID: 12126360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
The Papillon-Lefevre syndrome is a rare genetic disorder with a predisposition to severe infections. We describe Papillon-Lefevre syndrome in a 17 year old boy from a family where four out of eight siblings were affected with this disease and who presented with recurrent pyogenic liver abscesses over a period of 9 years, an association never previously reported.
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Singh NP, Manchanda V, Gomber S, Kothari A, Talwar V. Typhoidal focal suppurative lymphatic abscess. ANNALS OF TROPICAL PAEDIATRICS 2002; 22:183-6. [PMID: 12070955 DOI: 10.1179/027249302125000922] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
We describe a submandibular suppurative lymphatic abscess caused by Salmonella typhi in an 8-year-old child. The diagnosis was confirmed by repeated isolation of S. typhi from the abscess. A literature search found no previous report of a similar nature and this therefore seems to be the first case report of focal suppurative typhoidal lymphatic abscess. The child responded to cephalexin and surgical drainage.
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Singh NP, Ogburn CE, Wolf NS, van Belle G, Martin GM. DNA double-strand breaks in mouse kidney cells with age. Biogerontology 2002; 2:261-70. [PMID: 11868901 DOI: 10.1023/a:1013262327193] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A Biojector device fitted with a CO2 cartridge was used to prepare single cell suspensions from kidneys of 12-month- (middle-aged) and 24-month-old (old) C57B1/6 mice. Microgel electrophoresis of DNA from these cells revealed a modest but significant 7.3% increase (P = 0.04) in DNA double-strand breaks in old mice. This increase is equivalent to the DNA damage induced by 0.1 Gray of X-rays (5 double-strand breaks) in kidney cells of 10-month-old mice, as determined by a standard calibration curve. Greater DNA damage with aging was also positively correlated with higher levels of pathology in the kidneys.
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Anuradha S, Singh NP, Agarwal SK. Total dose infusion iron dextran therapy in predialysis chronic renal failure patients. Ren Fail 2002; 24:307-13. [PMID: 12166697 DOI: 10.1081/jdi-120005364] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Intravenous iron therapy is now the standard modality of iron supplementation in hemodialysis patients, but its role in predialysis chronic renal failure patients is less well established. The efficacy and safety of intravenous iron dextran as a total dose infusion in predialysis chronic renal failure patients, not receiving erythropoietin was assessed in this study. METHODS Fifty-six predialysis chronic renal failure patients with anemia, not receiving erythropoietin were included in the study, after obtaining informed consent. Hemoglobin, serum creatinine, creatinine clearance rate and serum ferritin were assessed in all the patients at baseline. Iron dextran in a dose of 1 g dissolved in 500 mL normal saline was administered to all patients as a total dose infusion over 6 h after a prior test dose. Patients were kept in hospital under observation for at least 24 h. All the parameters were repeated in all the patients at 12 weeks and in 21 patients at 1 year. RESULTS The mean hemoglobin (g/dL) in the patients at baseline and at 12 weeks was 8.28 +/- 0.57 and 9.22 +/- 0.44 respectively (p < 0.001). The mean serum ferritin (ng/mL) increased from 29.73 +/- 9.38 at baseline to 218.43 +/- 15.66 at 12 weeks (p < 0.00001). The mean ferritin value in the 21 patients at 1 year was 136.5 +/- 23.4 (p < 0.01). There were no major adverse events and only minor side effects were observed in 4.9% patients. CONCLUSION Iron dextran as a total dose infusion corrects anemia in predialysis patients and is an effective method to replenish iron stores. The effect on serum ferritin are evident even at 1 year after the total dose infusion.
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Duty SM, Singh NP, Ryan L, Chen Z, Lewis C, Huang T, Hauser R. Reliability of the comet assay in cryopreserved human sperm. Hum Reprod 2002; 17:1274-80. [PMID: 11980751 DOI: 10.1093/humrep/17.5.1274] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Although the comet assay has potential value for measuring DNA damage in large epidemiological human sperm studies, it is impractical to perform the assay daily on fresh semen samples. Therefore, before its use in epidemiological studies, the reliability of the comet assay in measuring DNA damage in cryopreserved sperm should be compared with that in fresh human sperm. METHODS Semen samples from 16 men were cryopreserved in liquid nitrogen (LN) using four methods: flash freezing with and without cryopreservative, and programmable freezing with and without cryopreservative. Neutral microgel electrophoresis was performed and comets were stained with YOYO-1. Comet length was measured using an eyepiece micrometer at x400 magnification. RESULTS The highest correlation was between comet assay results obtained from fresh human semen compared with semen flash frozen without cryopreservative (R = 0.88). However, the method of cryopreservation, as compared with other sources of variability, accounted for only 6% of the variability. Inter-individual variability accounted for 20%, and individual sperm-to-sperm variability within an ejaculate accounted for 65%. CONCLUSIONS Flash-freezing in LN without cryopreservative most closely reproduced the results obtained using fresh human semen samples, and thereby represents the most appropriate cryopreservation method for human semen in epidemiological studies utilizing the neutral comet assay.
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Anuradha S, Bansal R, Gupta A, Singh NP, Kohli R, Agarwal SK. Embolisation of haemodialysis catheter. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 2002; 50:608-9. [PMID: 12164426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
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Singh NP, Lai H. Selective toxicity of dihydroartemisinin and holotransferrin toward human breast cancer cells. Life Sci 2001; 70:49-56. [PMID: 11764006 DOI: 10.1016/s0024-3205(01)01372-8] [Citation(s) in RCA: 221] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Artemisinin becomes cytotoxic in the presence of ferrous iron. Since iron influx is high in cancer cells, artemisinin and its analogs selectively kill cancer cells under conditions that increase intracellular iron concentrations. We report here that after incubation with holotransferrin, which increases the concentration of ferrous iron in cancer cells, dihydroartemisinin, an analog of artemisinin, effectively killed a type of radiation-resistant human breast cancer cell in vitro. The same treatment had considerably less effect on normal human breast cells. Since it is relatively easy to increase the iron content inside cancer cells in vivo, administration of artemisinin-like drugs and intracellular iron-enhancing compounds may be a simple, effective, and economical treatment for cancer.
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Deshpande AU, Apte GS, Bahulikar RA, Lagu MD, Kulkarni BG, Suresh HS, Singh NP, Rao MK, Gupta VS, Pant A, Ranjekar PK. Genetic diversity across natural populations of three montane plant species from the Western Ghats, India revealed by intersimple sequence repeats. Mol Ecol 2001; 10:2397-408. [PMID: 11742544 DOI: 10.1046/j.0962-1083.2001.01379.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We analysed genetic diversity across the natural populations of three montane plant species in the Western Ghats, India; Symplocos laurina, Gaultheria fragrantissima and Eurya nitida using intersimple sequence repeat (ISSR) markers. These markers revealed genetic diversity within the populations of these plants from Nilgiri and also between two populations of S. laurina from Nilgiri and Amboli. Genetic variation within and between populations was analysed using various parameters such as total heterozygosity (HT), heterozygosity within population (HS), diversity between populations (DST), coefficient of population differentiation (GST), genetic distance (D) and gene flow (Nm). Total heterozygosity (HT) was higher for S. laurina (0.238) than for G. fragrantissima (0.172) and E. nitida (0.182). Two populations of S. laurina, separated by > 1000 km, showed a high within-population variation (53.7%) and a low gene flow (Nm = 0.447). upgma phenograms depicted a tendency of accessions to group according to their geographical locations in all the three plant species. The insight gained into the genetic structure of these plant populations might have implications in developing in situ and ex situ conservation strategies.
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Agrawal CS, Jain BK, Das DN, Singh NP. Solitary tuberculous abscess of liver. JOURNAL OF THE INDIAN MEDICAL ASSOCIATION 2001; 99:591-2. [PMID: 12018546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Tuberculous liver abscess (TLA) is an extremely rare condition even in the country where tuberculosis is an alarming public health problem. Here a case of TLA is reported from Nepal with diagnostic and management principles and review of literature.
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Agarwal SK, Singh A, Anuradha S, Singh NP, Sokhi J, Baveja UK. Cytokine profile in human immunodeficiency virus positive patients with and without tuberculosis. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 2001; 49:799-802. [PMID: 11837467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
BACKGROUND Human immunodeficiency virus (HIV) infection is associated with a profound dysregulation of the immune system and alterations in the cytokine profile. Tuberculosis, a common opportunistic infection in HIV positive patients, leads to further immune suppression and a faster progression of the disease. This study was conducted to assess and compare the cytokine profiles in HIV positive subjects with and without pulmonary tuberculosis. METHODS Twenty HIV positive patients and 20 controls were evaluated after being divided into four groups of 10 each--group 1--HIV positive patients without tuberculosis, group 2--HIV positive patients with pulmonary tuberculosis, group 3--healthy adults and group 4--HIV negative patients with pulmonary tuberculosis. After clinical evaluation, the CD4 cell counts and the cytokine profiles--interleukins (IL)-2, 4, 6, 10, 12, interferon gamma (IFN gamma) and tumour necrosis factor alpha (TNF alpha) were studied in all the subjects at the start and after three months of antituberculosis therapy. RESULTS the CD4 cell counts were significantly lower in groups 1 and 2 compared to groups 3 (p < 0.01) and the counts in group 2 were significantly lower than in group 1 in both at baseline (p = 0.0076) and at three months (p = 0.089). The levels of the type 1 cytokines (IL-2, IL-12 and IFN gamma were significantly lower in patients in groups 1 and 2 compared to group 3 (p < 0.001 for both). The levels in group 2 were lower than in group 1 (p < 0.001). The type 2 cytokines (IL-4, IL-6, IL-10 and TNF alpha) were higher in group 1 and 2 compared to group 3, though statistically significant for IL-6 in group 1 (p < 0.05) and for IL-4, IL-6 and TNF alpha in group 2. A highly significant (p < 0.0001) positive correlation between CD4 cell counts and type 1 cytokines and a highly significant (p < 0.0001) negative correlation between CD4 cell counts and type 2 cytokines was observed. CONCLUSIONS A decline in the type 1 and a rise in type 2 cytokines was observed in HIV infection. Patients in group 2 had the lowest CD4 cell counts, lowest levels of type 1 cytokines and highest levels of type 2 cytokines denoting maximum immunosuppression.
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Kshirsagar RD, Singh NP. Some less known ethnomedicinal uses from Mysore and Coorg districts, Karnataka state, India. JOURNAL OF ETHNOPHARMACOLOGY 2001; 75:231-238. [PMID: 11297857 DOI: 10.1016/s0378-8741(01)00199-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Present communication deals with 76 ethnomedicinal plants being used traditionally in Karnataka, India. These plants are reported to have 78 less known ethnomedicinal uses for curing various skin diseases, cuts, stomach disorders, gynaecological complaints and snakebites.
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Larson KL, Brannian JD, Singh NP, Burbach JA, Jost LK, Hansen KP, Kreger DO, Evenson DP. Chromatin structure in globozoospermia: a case report. JOURNAL OF ANDROLOGY 2001; 22:424-31. [PMID: 11330642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Sperm nuclear abnormalities in patients with globozoospermia have not been well characterized and may lead to the high rates of fertilization failure and embryo loss reported in patients with this form of teratozoospermia. This study used transmission electron microscopy (TEM), the sperm chromatin structure assay (SCSA), and single cell gel eletrophoresis assay (COMET) to assess if globozoospermia is associated with sperm chromatin structure abnormalities, DNA fragmentation, or both. The flow cytometric SCSA measures abnormal chromatin structure based on the susceptibility of sperm nuclear DNA to acid-induced denaturation in situ. COMET measures DNA fragmentation in individual sperm nuclei based upon gel electrophoretic patterns. Although sperm concentration (113 million/mL) and motility (66%) were normal in the patient, there was complete acrosome deficiency. TEM and SCSA data confirmed light microscopic examination that showed that sperm populations included a mixture of round and elongated sperm heads. Even though 100% of sperm had abnormal head morphology, only 13% demonstrated DNA denaturation (COMPalpha(t)), which is below our threshold of 15% COMPalpha(t), and consistent with high-fertility patients. Of interest, 13% of the sperm were also positive in the COMET assay, supporting our previous observations that SCSA-positive cells are also positive for DNA fragmentation. It was unexpected but of great interest that a human sperm population with 100% sperm morphology abnormalities had a chromatin integrity at the molecular level that is equivalent to sperm populations shown in previous studies to be highly fertile. These data are the first reported using SCSA and COMET assays to evaluate a patient with globozoospermia and support previous reports that intracytoplasmic sperm injection of globozoospermia may result in fertility/pregnancy. Lower success rates seen in some patients may be due to unrelated factors.
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