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Biomedical subjects

V Singh

Publications and source records attributed to V Singh.

At least 37 records · Page 2Linked to original sources
PubMed2004

Contrast-free unilateral endoscopic palliation in malignant hilar biliary obstruction: new method.

BACKGROUND: Bilateral endoscopic drainage is difficult in malignant hilar biliary obstruction. Recently, unilateral drainage in malignant hilar biliary obstruction has been shown to be equally effective. However, contrast injection leads to cholangitis. There have been no reported studies on contrast-free metal stenting in malignant hilar biliary obstruction. The present study was undertaken to evaluate the results of contrast-free unilateral metal stenting in type II malignant hilar biliary obstruction. METHODS: We prospectively studied the results of unilateral metal stenting in type II malignant hilar biliary obstruction without contrast injection in 18 patients. RESULTS: A successful endoscopic drainage was achieved in 100% (18/18) of patients with hilar strictures. Cholangitis and 30-day mortality occurred in none. CONCLUSIONS: Unilateral endoscopic metal stenting without contrast in type II malignant hilar biliary obstruction is a safe and effective method of palliation.

Biliary Tract Neoplasms↗
PubMed2004

Efficacy of extracorporeal shock wave lithotripsy for solitary lower calyceal stone: a statistical model.

OBJECTIVE: To evaluate the effect of inferior calyceal radiographic anatomy, number of extracorporeal shock wave lithotripsy (ESWL) sessions and stone size on the successful clearance of solitary inferior calyceal calculi after ESWL. PATIENTS AND METHODS: In a prospective study between January 2001 and November 2002, 66 renal units with a solitary inferior calyceal calculus of < or = 2 cm were treated with electrohydraulic ESWL. The infundibulopelvic angle (two definitions), infundibulovertebral angle, inferior calyceal infundibular diameter, infundibular length, cortical thickness over the lower pole, number of minor calyces and stone size were determined from intravenous urography before treatment. The number of ESWL sessions was also included in the analysis. Treatments which produced residual fragments not clearing within 3 months of satisfactory fragmentation were considered as failures. All patients in whom the treatment failed were treated successfully by percutaneous nephrolithotomy. The data were then analysed using two different statistical methods; first by intravariable differences using the test of proportion (Fisher's test) and then all the variables together using logistic regression. RESULTS: At 3 months 78.8% of the renal units were clear of stone. All intravariable differences were statistically significant except stone size (<1 cm, 1-2 cm). In a multivariate analysis of all variables, only stone size was the most important predictor for successful stone clearance (P = 0.03). CONCLUSIONS: ESWL is the initial treatment of choice in selected patients with inferior calyceal stones. The stone size appears to be the most important predictor for stone clearance.

Adolescent↗
PubMed2004

Spontaneous bilateral internal jugular vein thrombosis: a sign of metastasis.

Head and neck swellings are common referrals to the otolaryngology department, with a wide range of aetiologies. Internal jugular vein thrombosis presenting as swelling in the neck is a rare occurrence. The authors report a case of bilateral internal jugular vein thrombosis secondary to malignant lymphadenopathy of unknown origin. The patient presented with a short history of a diffuse swelling in the neck with neck stiffness. Examination revealed palpable cervical and axillary lymphadenopathy. Causes of spontaneous internal jugular vein thrombosis were discussed.

Adult↗
PubMed2004

Massive retropharyngeal lymphadenopathy in an infant: an unusual presentation of infectious mononucleosis.

Infectious mononucleosis causing upper airway obstruction due to tonsillar disease and associated lymphadenopathy in adolescents is well recognized. However, infection with Epstein-Barr virus (EBV) in a young child of six months is rare. The authors present such a case, with massive swelling of the retropharyngeal lymph nodes, that has not been published previously. The patient presented to this department with a short history of an upper respiratory tract infection and mild upper airway obstruction. On examination there was a massive enlargement of the retropharyngeal space with a compromised airway. This was confirmed on X-ray. She made an uneventful recovery following incision and drainage and a short period of endotracheal intubation. Because of the presence of retropharyngeal lymphoid tissue in infancy an alternative site of upper airway obstruction may occur here in this age group.

Airway Obstruction↗
PubMed2004

Aminoglycoside resistance in enterococci isolated from paediatric septicaemia in a tertiary care hospital in north India.

BACKGROUND & OBJECTIVES: Enterococci are important nosocomial agents and serious infections caused by them are often treated with a combination of cell wall inhibitor and aminoglycoside. However, the presence of high level aminoglycoside resistance in these isolates makes this treatment combination ineffective. The prevalence of such isolates in a tertiary care set up has important diagnostic and therapeutic implications. The present study was carried out to find out the occurrence of high level aminoglycoside resistant isolates of enterococci in paediatric septicaemia cases in a tertiary care set up in north India. METHODS: Blood of paediatric cases with a clinical diagnosis of septicaemia was cultured to isolate and identify enterococci. Agar screen method was used to detect high level streptomycin and gentamicin resistance in these isolates. Vancomycin susceptibility of these isolates were determined as per the National Committee for Clinical Laboratory Standards (NCCLS) recommendations. RESULTS: Fifty one enterococcal strains were isolated from 21 neonates, nine infants and 21 children with a clinical diagnosis of septicaemia. Sixty eight per cent of these isolates had high level gentamicin resistance and forty three per cent had high level streptomycin resistance. All the isolates with high level streptomycin resistance also had high level gentamicin resistance. More than ninety five per cent of these isolates were sensitive to vancomycin. INTERPRETATION & CONCLUSION: The occurrence of high level gentamicin and high level streptomycin resistance in enterococcal isolates in our set up was high. This would require routine testing of the enterococcal isolates for high level aminoglycoside resistance. Alternative treatment regimes need to be sought, besides prudent use of antibiotics.

Aminoglycosides↗
PubMed2003

Limit on the electron neutrino magnetic moment from the kuo-sheng reactor neutrino experiment.

A search of neutrino magnetic moment was carried out at the Kuo-Sheng Nuclear Power Station at a distance of 28 m from the 2.9 GW reactor core. With a high purity germanium detector of mass 1.06 kg surrounded by scintillating NaI(Tl) and CsI(Tl) crystals as anti-Compton detectors, a detection threshold of 5 keV and a background level of 1 kg(-1) keV(-1) day(-1) at 12-60 keV were achieved. Based on 4712 and 1250 h of reactor ON and OFF data, respectively, the limit on the neutrino magnetic moment of mu(nu;(e))<1.3x10(-10)mu(B) at 90% confidence level was derived. An indirect bound of the nu;(e) radiative lifetime of m(3)(nu)tau(nu)>2.8x10(18) eV(3) s can be inferred.

Journal Article↗
PubMed2003

A non-ionic water-soluble seed gum from Ipomoea campanulata.

A non-ionic water-soluble galactomannan, having galactose and mannose in 2:3 molar ratio was isolated from endosperm of the seeds of Ipomoea campanulata. The seed gum was found to have linear chain of beta (1-->4) linked mannopyranosyl units with D-galactose side chains attached through alpha (1-->6) linkage to the main chain. This structure is similar to many commercial gums like Guar, Carob and Locust bean gum. Various physical properties of the gum were studied in order to explore the possibility of commercial exploitation of the seed gum.

Galactose↗
PubMed2003

Delivery of antigen in allogeneic cells preferentially generates CD(4+) Th1 cells.

We have examined the possibility of evoking antigen-specific T cell immune response by using allogeneic cells as a source of adjuvant and also as a vehicle to deliver antigen. The mice were immunized with different preparations of antigen-pulsed allogeneic and syngeneic splenocytes. It was observed during the study that the animals immunized with antigen-pulsed mitomycin C treated allogeneic cells elicited antigen specific CD(4+) Th1 cell response. Predominant release of IL-2, interferon (IFN)-gamma and IgG2a-isotype also occurred. In contrast, mice immunized with antigen-pulsed syngeneic cells chiefly enhanced the production of interleukin (IL)-4 and IgG1-isotype. Further, allogeneic macrophages induced better T cell response than B cells or splenocytes and prominently induced the expression of B7-1 and B7-2. Immunization with antigen-pulsed macrophages provided better recall responses compared to B cells. This was manifested by the high LFA-1alpha and low CD45RB expression on T cells. Because it is already known that mitomycin C-treated cells undergo apoptosis and dendritic cells engulf apoptotic cells, we therefore propose that generation of T cell response using antigen-pulsed allogeneic cells may be due to the engulfment of these cells by dendritic cells, which may then process and present antigen entrapped in allogeneic cells to activate naive CD(4+) T cells and differentiate them to Th1 cells. This study therefore provides a rational basis for manipulating antigen-specific responses by immunizing with antigen-pulsed allogeneic cells.

Animals↗
PubMed2003

Adherence to tuberculosis treatment: lessons from the urban setting of Delhi, India.

The Revised National Tuberculosis Control Programme (RNTCP), which incorporated the WHO DOTS strategy was introduced in India in the mid-1990s. An operational research project was conducted between 1996 and 1998 to assess the needs and perspectives of patients and providers in two chest clinics in Delhi, Moti Nagar and Nehru Nagar, during the introduction of the new strategy. This paper reports on the findings of the project, concentrating on information collected from 40 in-depth interviews with patient defaulters and from non-participant observations in clinics and directly observed treatment centres. In Moti Nagar chest clinic, 117 of 1786 (6.5%) patients and 195 of 1890 (10%) patients in Nehru Nagar left care before their treatment was complete. It was argued that the reasons for default stem from a poor correlation between patient and programme needs and priorities, and from particular characteristics of the disease and its treatment. Patient needs that were not met by the health system included convenient clinic timings, arrangements for the provision for treatment in the event of a family emergency and provision for complicated cases like alcoholics. The problems facing the provider were poor interpersonal communication with the health staff, lack of attention and support at the clinic, difficulty for patients to re-enter the system if they missed treatment and, in certain areas, long distances to the clinic. Problems related to diseases were inability of the staff to deal with drug side-effects, and patients' conception of equating well-being with cure. Simple, practical measures could improve the provision of tuberculosis (TB) treatment: more flexible hours, allowances for poor patients to reach the clinics and training health care staff for respectful communication and monitoring drug side-effects. The findings indicate a need to rethink the label of 'defaulter' often given to the patients. The important areas for future operational research is also highlighted.

Adolescent↗
PubMed2003

A non-viral gene delivery system designed for clinical use.

Gene delivery can be accomplished using non-viral systems, and these have received increased attention These include ex vivo transfection of cells using an electric field to induce transient cell-membrane permeability (electroporation). This approach has the distinct advantage of not requiring the inclusion of a secondary agent (e.g. a lipid, viral package or carrier protein) any of which can be immunogenic or toxic. Available electroporation systems utilize a low volume (<1 mL) processing chamber and are open systems. The MaxCyte system employs a continuous flow design and can very rapidly process volumes ranging from 0.02 mL to >1 L. Transgenes for markers (eGFP) and functional proteins (e.g., cytokines, angiogenic factors) have been loaded in plasmids up to 14 kB in size. With appropriate application of pre- and post-processing cell manipulations, very satisfactory loading efficiencies and cell viability have been obtained. Cells can be processed with multiple plasmids, resulting in expression of the corresponding number of gene products. This capability has been considered for therapeutic and bioprocessing applications. The MaxCyte system was designed specifically for ex vivo clinical applications. The electrodes are manufactured of special materials and under precise conditions, in order to eliminate potential risks from electrolytic effects. The processing chamber and associated containers can be provided as disposable, sterile, closed (or functionally closed) systems-quite similar to the disposable harnesses used with cell separators. This system is thus suitable for integration into a current good manufacturing practice environment.

Clinical Trials as Topic↗
PubMed2003

Distinguishing intracerebral hemorrhages caused by arteriovenous malformations.

BACKGROUND: There is a shortage of data addressing the clinical characteristics of patients with arteriovenous malformations (AVMs) who present with intracerebral hemorrhages (ICH). METHODS: A retrospective cohort study of members of a large, pre-paid health care program was conducted to identify factors that distinguish ICH secondary to cerebral AVMs from all other causes. Univariate and multivariate analysis was performed using Student's t test, Wilcoxon rank-sum test, and logistic regression. RESULTS: Patients with an underlying AVM were younger and more likely to be female, non-smokers with lower blood pressures, lower cholesterol, and lower white blood cell counts on presentation. CONCLUSIONS: These clinical characteristics may be useful in defining potential risk factors in future prospective studies as well as targeting candidates for additional imaging studies after ICH with no apparent etiology.

Adult↗
PubMed2003

Acute intermittent porphyria: an unusual cause of malignant hypertension.

Hypertension is a rare complication of acute intermittent porphyria (AIP) and is related to the sympathetic over-activity seen in this condition. We report a patient with AIP with malignant hypertension that recurred with a subsequent episode. Mechanisms of hypertension and renal damage are discussed.

Adolescent↗
PubMed2002

Viability of dried filaments, survivability and reproduction under water stress, and survivability following heat and UV exposure in Lyngbya martensiana, Oscillatoria agardhii, Nostoc calcicola, Hormidium fluitans, Spirogyra sp. and Vaucheria geminata.

Dried vegetative filaments of Spirogyra sp., Vaucheria geminata and Nostoc calcicola died within 1/2, 1 and 4 h, respectively; those of Hormidium fluitans, Oscillatoria agardhii and Lyngbya martensiana retained under similar storage conditions viability for 3, 5 and 10 d, respectively. The viability of dried vegetative filaments of L. martensiana, O. agardhii and H. fluitans decreased on storage at 20 degrees C in the dark. L. martensiana and O. agardhii tolerated 0.8 mol/L NaCl. The resistance to desiccation in L. martensiana and O. agardhii exhibited similar dependence as that to frost, to heat and UV light. O. agardhii filaments became slightly broader and their cells developed large number of gas vacuoles when grown in 0.8 mol/L NaCl-containing medium. The water stress imposed on growing algae either on high-agar solid media or in NaCl-containing liquid media reduced hormogonium formation in L. martensiana and O. agardhii, heterocyst and akinete formation in N. calcicola and fragmentation in H. fluitans; it did not induce conjugation in Spirogyra sp. and formation of reproductive organs in V. geminata. In all studied algae the stress reduced at various levels the survival of vegetative parts. Generally, algal body form and composition rather than habitats seem to decide primarily the level of resistance against various stress conditions.

Culture Media↗
PubMed2002

Anti-oxidant and immunomodulatory properties of seabuckthorn (Hippophae rhamnoides)--an in vitro study.

This study was designed to determine the anti-oxidant and immunomodulatory properties of seabuckthorn (Hippophae rhamnoides) using lymphocytes as a model system. Chromium(VI) as potassium dichromate was used to induce oxidative damage. The production of free radicals by chromium and the ability of alcoholic leaf and fruit extracts of seabuckthorn to inhibit the oxidative damage induced by chromium was investigated. Addition of chromium (10 microg/ml) to the cells resulted in enhanced cytotoxicity, apoptosis, free radical production and decreased glutathione (reduced) levels. Chromium also caused a significant inhibition of lymphocyte proliferation induced by both lipopolysaccharide and concanavalin A. Alcoholic extracts of leaves and fruits of seabuckthorn at a concentration of 500 microg/ml were found to inhibit chromium-induced free radical production, apoptosis, DNA fragmentation and restored the anti-oxidant status to that of control cells. In addition, these extracts also were able to arrest the chromium-induced inhibition of lymphocyte proliferation. These observations suggest that the alcoholic extracts of leaves and fruits of seabuckthorn have marked cytoprotective properties, which could be attributed to the anti-oxidant activity.

Adjuvants, Immunologic↗
PubMed2002

TB control, poverty, and vulnerability in Delhi, India.

The Revised National Tuberculosis Control Programme (RNTCP), based on the World Health Organization's DOTS strategy,* was introduced in India in the mid-1990s. This paper reports the findings from operational research studies in two pilot sites in New Delhi from 1996 to 1998. A variety of operational research methods were used, including semi-structured interviews, focus group discussions, non-participant observations and collection of data from the tuberculosis registers. The cure rates for the clinics were 71 and 75% with a default rate of 6 and 11%, respectively. An important finding was that health workers screened patients to determine their ability to conform to the direct observation of treatment element of the RNTCP. If the health worker was confident that the patient would comply and/or be easy to trace in the community in the event of 'default', they were provided with short-course treatment under the RNTCP. Other patients, largely those who were in absolute poverty, socially marginalized, itinerant labourers, poorly integrated in the city, were put on standard tuberculosis (TB) treatment as for the previous National TB Programme. The programme was evidently excluding the most vulnerable from the best available care. These findings demonstrate the potential dangers of target-driven programmes where there is an absence of support to both frontline health workers and patients. The paper also highlights the importance of operations research in helping to identify problems within TB programmes.

Antitubercular Agents↗