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Biomedical subjects

M Singh

Publications and source records attributed to M Singh.

At least 91 records · Page 5Linked to original sources
PubMed2004

Maternal intravaginal prostaglandin E2 gel before elective caesarean section at term to induce catecholamine surge in cord blood: randomised, placebo controlled study.

OBJECTIVE: To test the hypothesis that the application of intravaginal prostaglandin E(2) gel before elective caesarean section (ECS) will induce a catecholamine surge in umbilical arterial blood. DESIGN: Randomised, double blind, placebo controlled trial. SETTING: A regional perinatal referral centre. PATIENTS: Mothers booked for ECS at or above 38 weeks gestation. INTERVENTIONS: Thirty six consenting mothers were randomly allocated to receive either 2 mg intravaginal prostaglandin E(2) gel (study group; n = 18) or an equal volume of K-Y jelly as a placebo (control group; n = 18) 60 minutes before the ECS. Computer generated random numbers contained in coded, sealed envelopes were used for allocation. The obstetric and neonatal teams were blinded to the randomisation status of enrolled mothers. MAIN OUTCOME MEASURES: Catecholamine concentrations in the umbilical arterial blood samples collected at delivery. RESULTS: The median (interquartile range) neonatal gestation and birth weight were 271 (269-274) days and 3605 (3072-3970) g for the study group and 271 (270-273) days and 3340 (3000-3622) g for the control group. Median (interquartile range) noradrenaline (norepinephrine) concentrations in the umbilical arterial blood were significantly higher in the study group than the control group (15.9 (9.8-28.92) v 4.6 (1.65-14.4) ng/l, p = 0.03). Adrenaline (epinephrine) concentrations did not differ significantly between the two groups (1.6 (< 0.5-3.1) v 1.4 (< 0.5-2.75) ng/l, p = 0.6). No treatment related complications occurred. CONCLUSION: A labour related catecholamine surge could be simulated by intravaginal prostaglandin E(2) gel.

Administration, Intravaginal↗
PubMed2004

Gastro-oesophageal reflux and bronchial asthma: current status and future directions.

In recent years there have been several reports suggesting an association between bronchial asthma and gastro-oesophageal reflux; however a cause and effect relationship has not been proven yet. Confirmation of such a relationship is likely to have far reaching implications on the management of asthma. Reliable assessment of this issue is hampered by the presence of various lacunae in most of the published studies. Hence it is essential to carefully examine the strength of data suggesting a link between asthma and reflux. This article critically analyses currently available literature on the subject (including published reviews, meta-analyses, and randomised clinical trials in the English language) and summarises valid conclusions that can be drawn; it also proposes a framework for future studies to resolve the issue.

Asthma↗
PubMed2004

Percutaneous absorption and skin irritation upon low-level prolonged dermal exposure to nonane, dodecane and tetradecane in hairless rats.

Even though the dermal toxicity of hydrocarbon fuels has been well established in the literature, there is little information available on the dermal penetration kinetics and irritation potential of the individual hydrocarbons. The penetration and skin retention of nonane, dodecane and tetradecane was assessed in vitro using hairless rats' skin. The effects of unocclusive dermal exposures of these chemicals (15 microL every 2 h for 8 h a day for four days) on the transepidermal water loss (TEWL) and erythema were measured in CD hairless rats. The expression of interleukin 1alpha (IL- 1alpha) and TNF-alpha in the skin and blood were measured at the end of dermal exposures. The flux of dodecane was 3- and 77-fold higher than nonane and tetradecane. The retention of chemicals in stratum corneum (SC) was in the order of tetradecane > dodecane > nonane, and directly correlated to the log Kp (r2 = 0.9900) and molecular weight of the chemicals (r2 = 0.8782). The TEWL and erythema data indicate that irritation was in the following order: tetradecane > dodecane > nonane. Likewise, the expression of IL-lalpha in the blood and TNF-alpha in the skin after dermal exposures was higher for tetradecane followed by dodecane and nonane compared to control. In conclusion, the aliphatic hydrocarbon chemicals of the present study induced cumulative irritation upon low-level repeat exposures for a four-day period. The affinity of the chemicals to SC and their gradual accumulation in the skin in the present study is the probable cause for the differences in the skin irritation profiles of different aliphatic chemicals. The findings of the present study will be helpful in understanding the skin irritation response of the chemicals in humans; indeed the reality check arises from dermal exposures in humans and human experience in occupational handling of these chemicals.

Administration, Cutaneous↗
PubMed2004

Changes in the reproductive system of male mice immunized with a GnRH-analogue conjugated to mycobacterial hsp70.

Immunosterilization is an attractive alternative to surgical castration. Gonadotropin-releasing hormone (GnRH) controls the production of the gonadotropins thereby having an orchestrating effect on the reproductive hormone cascade and spermatogenesis. Induction of neutralizing antibody can abrogate the effect of the hormone. Current GnRH-based vaccines often require strong adjuvants and/or multiple injections of the vaccines to overcome variability in the response. Heat shock proteins (hsp) have been used as carrier molecules because of their powerful intrinsic ability to enhance an immune response to associated antigens. A GnRH-analogue, GnRH-d6-Lys, was conjugated to recombinant Mycobacterium tuberculosis hsp70. Male BALB/c mice were immunized i.p. with GnRH-hsp70 in the mild adjuvant Ribi or in incomplete Freund's adjuvant (IFA). The initial immunizations were done on pre-pubertal 3-week-old mice, with boosts at 5 and 8 weeks of age. The mice were killed at 10 weeks of age and GnRH-specific antibodies and serum testosterone levels measured. All the immunized mice mounted GnRH-specific antibody responses, with no difference in the mice immunized with GnRH-hsp70/Ribi or with GnRH-hsp70/IFA. There was substantial atrophy of the urogenital complex and significantly (P < 0.0005) reduced levels of testosterone-dependent testicular relaxin-like factor mRNA expression. Mice immunized with GnRH-hsp70/Ribi showed substantially reduced (P < 0.001) serum testosterone levels. These results indicate that hsp70 may serve as a particularly advantageous carrier for GnRH-based vaccines.

Adjuvants, Immunologic↗
PubMed2004

Protective effect of ginger, Zingiber officinale Rosc on experimental atherosclerosis in rabbits.

The effects of air dried ginger powder (0.1g/kg body weight, po, for 75 days) were studied on experimentally induced atherosclerosis in rabbits by cholesterol feeding (0.3g/kg body weight, po). Cholesterol feeding for 75 days lead to distinct development of atheroma in the aorta and coronary arteriesof the rabbits and this was significantly inhibited by about 50% following ginger administration. There was distinct decrease in lipid peroxidation and enhancement of fibrinolytic activity in ginger treated animals. However, ginger did not lower blood lipidsto any significant extent. This distinct protection from the development of atherosclerosis by ginger is probably because of its free radical scavanging, prostaglandin inhibitory and fibri properties.

Animals↗
PubMed2004

Influence of hyperglycemia on aggregation, deformability and shape parameters of erythrocytes.

The hemorheological and morphological changes in blood samples of diabetic patients, with varying levels of hyperglycemia but normal cholesterol concentration, are determined and are compared with healthy subjects. The shape analysis is carried out by shape descriptors based on projected area, perimeter and form factor, as measured by processing of images of erythrocytes. The aggregation and deformability of erythrocytes are measured by sequential variation of the transmitted laser light after passing through the erythrocytes suspension in plasma and passage of erythrocytes suspension in physiological saline through cellulose membrane, respectively. The results show that with the increase of glucose concentration the erythrocytes aggregation is enhanced and deformability is reduced in diabetic patients compared to that of healthy subjects. The shape parameters, which quantify the changes in erythrocytes in diabetes, show significant deviation from the shape of normal cells. A significant increase in the perimeter to area ratio and form factor in hyperglycemia also corresponds to highly significant increase in filtration time (decrease in deformability).

Adult↗
PubMed2004

Hereditary opalescent dentin--a case report.

A female patient aged 6 years reported with brown coloured small sized teeth that were continuously wearing out. The teeth were badly attrited upto the gingival margins. The occlusal surfaces were flattened. The clinical and radiographical examination confirmed the case as Hereditary opalescent Dentin. The rationale for early diagnosis and treatment has been discussed.

Child↗
PubMed2003

The influence of various methods of cold storage of skin on the permeation of melatonin and nimesulide.

The purpose of this study was to investigate the influence of different methods of skin preservation on the percutaneous permeation of two drugs with varied physicochemical properties (melatonin and nimesulide). Hairless rat skin was freshly excised and immediately stored at three different storage conditions: (a). 4 degrees C in minimal essential medium eagle (MEM), (b). frozen at -22 degrees C and (c) frozen at -22 degrees C in 10% glycerol (as a cryoprotective agent). The permeation of melatonin and nimesulide from saturated solutions was studied using the skin stored at various cold storage conditions for 6 months. At 4 degrees C, the flux of melatonin was similar to fresh skin for up to 7 days (P>0.05) and increased 2.4-fold at 14 days (P<0.001). The flux of melatonin was similar to fresh skin for 14 days with skin at -22 degrees C (P>0.05) and then steadily increased from 30 days onwards and at 180 days, the flux was 5-fold greater than fresh skin (P<0.001). Freezing of skin at -22 degrees C with 10% glycerol showed similar flux values for melatonin up to 60 days and at 180 days the flux increased 2.2-fold as compared to fresh skin (P<0.001). In the case of nimesulide, the skin stored for 2 days at 4 degrees C showed similar flux as compared to fresh skin (P>0.05) and increased steadily from 4 days onwards and at 14 days the flux was 3.5-fold higher than fresh skin (P<0.001). The skin frozen at -22 degrees C with or without 10% glycerol showed no difference in flux up to 4 days which however increased from 7 days onwards. At 180 days, the skin at -22 degrees C showed 2.5-fold increase in the flux (P<0.001) whereas the skin frozen with 10% glycerol showed 2-fold increase in the flux (P<0.001) as compared to fresh skin. The results of the present study demonstrate that the permeability of the drugs across the stored skin was dependent on the storage condition, the length of storage and the physicochemical properties of the drug under study. Overall, the freezing of skin at -22 degrees C with 10% glycerol was found to be very helpful for the long-term storage of skin for percutaneous permeation studies.

Animals↗
PubMed2003

Laser reflectance imaging of human forearms and their tissue-equivalent phantoms.

Laser back-scattered radiation from a human forearm is affected by the compositional variation in tissues and was imaged by a reflectance imaging system. The measurement probe consisted of one input fibre and one output fibre, separated by a distance of 0.3 cm. The diffuse reflectance data were collected by placing the probe on the forearm. By interpolation and median filtering of these data, the colour-coded reflectance images of the forearms of ten subjects were reconstructed. For comparative analysis of the mean reflectance, the forearm area was divided into ten regions. The mean normalised back-scattered intensity (NBI) near the ulnar region of the wrist was 4.76 +/- 0.24% and was significantly higher (p < 0.0005) compared with that at other regions, which varied from 3.49 +/- 0.17% to 4.43 +/- 0.14%. Tissue-equivalent phantoms of these, required for the clinical assessment of optical techniques, were constructed using various combinations of paraffin wax and dyes. The matching of the NBI images of these stable and inexpensive phantoms with those of the forearms of the respective subjects showed the similarity of their optical parameters.

Adult↗
PubMed2003

Non-invasive imaging of optical parameters of biological tissues.

The normalised back-scattered intensity (NBI) profiles at various locations on the forearms of ten human subjects were obtained by moving the multi-probe of a laser reflectometer. The statistical analysis of the NBI data showed that the variation in the NBI was significantly higher at the ulnar region compared with that at other regions. For determination of the scattering (mus) and absorption (mus) coefficients and the anisotropy parameter g at each location on the forearm, these profiles were matched with the NBI profiles simulated by a Monte Carlo procedure (chi(2)0.99). For the reconstruction of images of variation of these parameters, the averaged values of mua, mus, and g at all locations on the forearms of the subjects were determined. The absorption coefficient had a minimum (1.92 cm(-1)) and maximum (2.21cm(-1)) at the wrist and the lateral region of the forearm, respectively. The scattering coefficient had a maximum (194 cm(-1)) at the medial side and near the elbow, and a minimum (186 cm(-1)) at the lateral side of the forearm. Similar changes in the anisotropy parameter were also observed. By interpolation of the data of each parameter on a 100 x 100 image matrix and after median filtering, colour-coded images of the variation in the optical parameters were constructed. These images could be useful for diagnostic and therapeutic applications of lasers.

Adult↗
PubMed2003

Evaluation of an aerosolized selective COX-2 inhibitor as a potentiator of doxorubicin in a non-small-cell lung cancer cell line.

PURPOSE: To evaluate the in vitro effects of an aerosolized cyclooxygenase-2 (COX-2) inhibitor, nimesulide, on the cytotoxicity and apoptotic response of doxorubicin against the human lung adenocarcinoma cell line A549. METHODS: Nimesulide was formulated into a metered dose inhaler (MDI) formulation and characterized for aerodynamic particle size and medication delivery. The in vitro cytotoxicity of nimesulide-MDI in the presence or absence of doxorubicin was assessed by using the six-stage viable impactor by an already standardized method. Induction of apoptosis in A549 cells by nimesulide (nonaerosolized or aerosolized) in combination with doxorubicin was evaluated by established techniques such as caspase-3 estimation and terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) staining. Finally, to understand the mechanism of action, the influence of different treatments on the expression of COX-2 and peroxisome proliferator-activated receptor-gamma (PPAR-gamma) in A549 cells was studied by immunoblotting. RESULTS: The nimesulide-MDI formulation had a mass median aerodynamic diameter (MMAD) of 1.1 microm, (GSD = 2.8) and a medication delivery of 51 microg/shot. Nimesulide-MDI (40 shots) in combination with doxorubicin (0.01 microg/ml) had a cell kill of more than 60% as determined by in vitro cytotoxicity assay. The specific caspase-3 activity in A549 cells treated with nimesulide (40 microg/ml) and doxorubicin (0.25 microg/ml) in combination was 3 and 5 times higher than doxorubicin and nimesulide, respectively. Further, TUNEL staining showed apoptosis in over 30% of A549 cells treated with aerosolized nimesulide and doxorubicin combination vs. negligible as seen in cells treated individually. The expression of COX-2 was not altered in control or treatments, whereas PPAR-gamma was expressed only in the combination treatment. CONCLUSION: Our results indicate that aerosolized nimesulide significantly enhances doxorubicin activity against A549 cells, and the enhanced cytotoxicity was probably mediated via a COX-2-independent mechanism.

Aerosols↗
PubMed2003

Nosocomial outbreak of diarrhoea by enterotoxigenic Escherichia coli among preterm neonates in a tertiary care hospital in India: pitfalls in healthcare.

An outbreak of watery diarrhoea accompanied by low-grade fever and weight loss in 16 preterm neonates (age range 2-20 days) admitted to a neonatal intensive care unit (NICU) over four days in August 2000 is reported. Escherichia coli having similar antibiograms were identified on routine bacterial stool cultures in 14 (87.5%) neonates and none of the other known enteropathogens were detected. An investigation was undertaken to trace the source of infection. Surveillance cultures of swabs from the utensils used to prepare milk feed, culture of the formula feed and all items handled by one particular cook yielded growth of E. coli as did culture of his hand swabs and faecal sample. The causative agent was identified as enterotoxigenic E. coli (ETEC) as toxin production could be demonstrated by reverse passive latex agglutination in all the strains of E. coli isolated both from the infected neonates and the source of infection. The outbreak was effectively controlled by appropriate therapy and institution of proper measures of hygiene after identification of the source of infection.

Animals↗
PubMed2003

Empyema thoracis: a 10-year comparative review of hospitalised children from south Asia.

AIMS: To study the clinical and microbial profile of childhood empyema in South Asia and to identify the changes over the past three decades. METHODS: A total of 265 children (aged 1 month to 12 years) with empyema admitted to the Advanced Pediatric Center, PGIMER, Chandigarh, India in 1989-98, were reviewed retrospectively. RESULTS AND CONCLUSIONS: One third of children were under 5. Culture positivity had decreased significantly (48% v 75%) over the years. Staphylococcus aureus continues to be the commonest (77%) aetiological agent; clustering was seen during hot and humid months (46%). Culture positive Streptococcus pneumoniae cases also decreased (9% v 27%); all were seen during the winter and spring season. Gram negative rods grew in more patients (11% v 7%). Community acquired methicillin resistant S aureus (MRSA) was isolated in three patients. Most children (93%) were treated with parenteral cloxacillin and an aminoglycoside. Tube drainage (TD) was used in 92% of fibropurulent cases, and was successful in 79%. Of 48 patients with failed TD, 12 needed decortication; limited thoracotomy was sufficient in the remaining 36. Surgery was mainly required by children with persistent pleural sepsis after 10 days of TD. Delaying surgery until 14 days had a significantly higher potential of requiring decortication. Early change to oral antibiotics (after 1-2 weeks of parenteral therapy) reduced the hospital stay significantly (17+7 v 23+7 days) without compromising long term outcome. Twenty two patients presenting late in the chronic stage underwent decortication at admission.

Anti-Bacterial Agents↗
PubMed2003

Comparison of oral versus intravenous iron therapy in predialysis patients of chronic renal failure receiving recombinant human erythropoietin.

OBJECTIVES: To compare oral versus intravenous iron in pre-dialysis patients of chronic renal failure (CRF) receiving recombinant human erythropoietin (rHuEPO). METHODS: The study was undertaken in 40 adult patients of chronic renal failure. The patients were randomly divided into two groups A and B of 20 patients each. Group A patients were given oral iron and group B patients were given intravenous iron. All patients in both groups were given recombinant human erythropoietin 2000 IU twice weekly subcutaneously. The study was carried for up to three months. Patients were monitored every month for renal parameters and haematological parameters which included haemoglobin, reticulocyte count and packed cell volume. Ferrokinetic studies were done at baseline and at three months. RESULTS: It was observed that haematological parameters showed significant statistical improvement in the intravenous iron group as compared to group A (oral iron group). The ferrokinetic studies revealed that serum iron, serum ferritin and transferrin saturation, decreased significantly in oral iron group, whereas significant increase was seen in group B (intravenous iron group). None of the patients developed any adverse effects because of erythropoietin or iron therapy. CONCLUSIONS: Concomitant use of intravenous iron is better than oral iron in CRF patients treated with rHuEPO. The intravenous route of iron administration may be a preferred route along with rHuEPO therapy, more so in the Indian context where prevalence of iron deficiency anaemia is fairly high.

Administration, Oral↗
PubMed2003

Age specific incidence rate and pathological spectrum of oral cancer in Allahabad.

BACKGROUND: Cancer of the oral cavity is one of the commonest cancers in India. Use of smokeless tobacco (Pan masala, Zarda etc ) is on the increase in North India and specially in Uttar Pradesh. AIMS: To assess the patients characteristics and histopathological subtypes of the oral cancer in our region. SETTINGS AND DESIGN: A single institutional retrospective study of 11 years from 1990 to 2000 was designed. Data was collected year wise using the tumour registry data. MATERIAL AND METHODS: A total of 40,559 biopsies were examined in the department during 1990-2000, out of which the oral cavity constituted 759 biopsies. The data was analysed with emphasis on age, sex, risk factors, site and histology. STATISTICAL ANALYSIS: The data was analysed utilizing the Kolomogroo-Smirnov two sample test. RESULTS: A comparison of the age specific incidence rates of oral cancer during 1990-2000 in Allahabad showed that the incidence was maximum in the 50-59 years age group and squamous cell carcinoma grade I was the most prevalent type. Of the total of 759 biopsies from oral cavity, 303 malignant cases. 232 (76.57%) were males and 71 (23.43% were females with a male to female ratio of 3.27:1. The tongue was the most frequently involved site--found in 42.57% cases. On an average, 63 new cases of oral cavity per annum were detected during this period. CONCLUSIONS: Properly structured site specific data like this can augment National Cancer Registry Programme (NCRP) and is an essential indicator for the magnitude and the pattern of the cancer problem in India Urgent public health measures like public education and oral cancer awareness are required to curb this avoidable epidemic.

Age Distribution↗