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Biomedical subjects

M Singh

Publications and source records attributed to M Singh.

At least 271 records · Page 15Linked to original sources
PubMed2000

Stilboestrol plus adrenal suppression as salvage treatment for patients failing treatment with luteinizing hormone-releasing hormone analogues and orchidectomy.

OBJECTIVE: To investigate the efficacy of low-dose stilboestrol (SB) with hydrocortisone in patients with advanced prostate cancer refractory to androgen suppression. PATIENTS AND METHODS: Thirty-four consecutive patients (median age 70 years, range 51-83) with metastatic disease who progressed on hormone therapy, as shown by recurrent/worsening symptoms and an increase in prostate-specific antigen (PSA) level, were recruited and discontinued hormonal treatment before starting SB. Patients received SB (1 mg/day) combined with hydrocortisone (40 mg/day). In an attempt to reduce the incidence of thrombo-embolic events, aspirin (75 mg/day) was also added. RESULTS: Stilboestrol was the second-line treatment in 19 patients and the third or fourth in 15. The median (range) duration of treatment with SB was 5 (0.5-21) months and the median follow-up 7.5 months, with 18 patients still alive and 14 still on treatment. Of 29 symptomatic patients, 24 had symptomatic improvement and five had no clear benefit; the median duration of benefit was 6 (2-21) months. The PSA level decreased by 0-50% in six patients, by 50-90% in 13 and by > 90% in eight, while there was symptomatic improvement in these three categories in five, 11 and seven patients, respectively. The median times to PSA nadir and progression were 4 and 6 months, respectively. Some thrombo-embolic events and fluid retention occurred but overall the treatment was well tolerated. CONCLUSION: Low-dose SB with hydrocortisone is effective in refractory prostate cancer, although there is some toxicity. Randomized studies against hydrocortisone or SB alone are needed to establish the cost/benefit ratio of this combination.

Aged↗
PubMed2000

A 3-year follow-up of a prospective randomized trial comparing transurethral electrovaporization of the prostate with standard transurethral prostatectomy.

OBJECTIVE: To compare the safety, efficacy and durability of transurethral electrovaporization of the prostate (TUVP) with standard transurethral resection of the prostate (TURP). PATIENTS AND METHODS: In all, 104 patients admitted from the waiting list for surgery for BPH were randomized to either TUVP (52 patients, mean age 67.5 years) or TURP (52 patients, mean age 70.2 years); 51, 47 and 40 patients in each arm completed 1, 2 and 3 years of follow-up, respectively. Patients were assessed at baseline and during the follow-up using the International Prostate Symptom Score (IPSS), the associated quality-of-life score (QoL), postvoid residual volume (PVR) and maximum urinary flow rate (Qmax). RESULTS: Both groups had comparable mean IPSS, QoL, Qmax and PVR at baseline. The mean (SD) values for TUVP and TURP, respectively, at 3 years showed a significant and maintained improvement in IPSS, at 4.1 (3.3) and 7.1 (6.2) (P = 0.01), in QoL, at 1.0 (0.9) and 1.6 (1.4) (P = 0.04), and in Qmax, at 22.2 (8.5) and 18 (7.1) mL/s (P = 0.02), with decreases in PVR of 30 (38) and 21.9 (26.2) mL (P = 0.27). The re-operation rate in each group was 4% during the first year, 4% during the second year and 5% during the third year. After surgery and at 1, 2 and 3 years of follow-up, impotence was reported in 17% of the TUVP group and 11% of the TURP group (P = 0.49), and retrograde ejaculation in 72% of the TUVP group and 89% of the TURP group (P = 0.47). CONCLUSION: The 3-year follow-up results confirm that TUVP is as effective as standard TURP in the treatment of moderate-sized BPH. The long-term side-effects and complications were comparable and the initial improvement was maintained over 3 years in most patients in both groups.

Aged↗
PubMed2000

Constructing surfaces and contours in displays of color from motion: the role of nearest neighbors and maximal disks.

Color-from-motion displays consist of a sparse array of dots which never move but change color according to various algorithms. Yet such displays can trigger human vision to construct apparent motion of a subjective surface which is uniformly colored and bounded by a subjective contour. We show that the perceptual strength of this construction depends on the density and regularity of dot placement. We studied three objective measures of density and regularity: nearest-neighbor distance, mean of maximal disks, and variance of maximal disks. We found that nearest-neighbor mechanisms alone are inadequate to account for the perceptual strength of the subjective surfaces and contours. Mechanisms sensitive to areal gaps provide a more adequate account.

Color Perception↗
PubMed2000

Incidence, clinical spectrum, and outcome of intrauterine infections in neonates.

A prospective study was undertaken on the incidence of intrauterine infections by screening 1302 cord blood samples for total IgM by radial immunodiffusion. Specific IgM against cytomegalovirus (CMV), rubella and Toxoplasma were estimated in cord blood samples found to contain total IgM > 20 mg/dl. All these neonates were examined at birth and at discharge. Cord blood samples with total IgM > 20 mg/dl were further screened for specific IgM against rubella, CMV and Toxoplasma. Neonates found to have positive specific IgM were followed-up for hearing, opthalmological and developmental assessment. Raised cord blood (IgM > 20 mg/dl) was found in 270/1302 (20.6 per cent). Mean birth weight was comparable in babies with raised (> 20 mg/dl) or low (< 20 mg/dl) cord blood total IgM. Incidence of prematurity and low birth weight were not statistically different in babies with raised cord blood IgM when compared to those with low cord blood IgM levels. Similarly, incidence of intrauterine growth retardation (IUGR) idiopathic was similar in two groups. Specific IgM for rubella was found to be positive in eight (0.6 per cent). Of these, three had symptomatic rubella infection. Two mothers of these symptomatic babies had exanthematous viral illness during first trimester. Specific IgM for CMV was found to be positive in 23 (1.8 per cent) while two infants had symptomatic CMV disease. None of the babies was found to have specific IgM against Toxoplasma. One baby with symptomatic CMV disease and one with rubella died. Another baby with symptomatic CMV disease developed neonatal hepatitis which improved on follow-up but the infant went on to develop sensorineural deafness. All other asymptomatic babies with specific IgM positive against rubella and CMV were found to have normal vision, hearing and development on follow-up.

Animals↗
PubMed2000

The National Movement of Neonatal Resuscitation in India.

Birth asphyxia is an important cause of preventable neonatal morbidity and mortality in developing countries. Of the 26 million births each year in India, 4-6 per cent of neonates fail to establish spontaneous breathing at birth. These babies can be helped, if healthcare professionals present at the time of birth are skilled in the art of neonatal resuscitation. Since the introduction of the Neonatal Resuscitation Programme (NRP) by the American Academy of Pediatrics and American Heart Association, organized training programmes for instructors and providers have been launched in India, under the aegis of the National Neonatology Forum (NNF) since 1990. The initial goal was to train the trainers and provide them with the necessary equipment. The NNF created a national faculty of 150 pediatricians and nurses for NRP by conducting certification courses in various regions of the country. The certified faculty members in turn trained 12,000 healthcare professionals in various parts of India over the following 2 years. Simultaneously, in several teaching institutions, NRP was introduced into the curricula of medical and nursing students. This programme provides a uniform, systematic and action-oriented approach to the resuscitation of the newborn. Prospective evaluation of the resuscitation programme in teaching hospitals has revealed the use of rational resuscitation practices and a significant decline in asphyxia-related deaths.

Asphyxia Neonatorum↗
PubMed2000

Three-dimensional reconstruction of transillumination tomographic images of human breast phantoms by red and infrared lasers.

A laser transillumination tomographic system, using red and near infrared lasers, to obtain cross-sectional images of human breast phantoms and human hand is proposed. The scanning assembly is consisting of upward, downward, rotational and pitch movements. The phantoms, made of paraffin wax, agar gel, and milk placed in a glass model, are embedded with abnormalities like blood, water, solid objects, and tissues. By illuminating the phantoms at various heights by either red or infrared laser the projection data are collected. Based on 64 projections the tomogram of each section is constructed. By volume visualization procedure applied to the tomograms the objects of varying composition embedded within the phantoms are detected and their size, shape, and location depth are determined. The cross-sectional image of a human hand obtained by this procedure further shows the possibility of application of this technique for imaging of organs.

Algorithms↗
PubMed2000

Antigen specificity in experimental bovine tuberculosis.

This report describes the kinetics of T-cell responses to a panel of mycobacterial antigens (PPD-M, PPD-A, ESAT-6, Ag85, 38kD, MPB64, MPB70, MPB83, hsp16.1, hsp65, and hsp70) following experimental infection of cattle with Mycobacterium bovis. Increased antigen-specific lymphocyte proliferation, gamma interferon, and interleukin-2 responses were observed in all calves following infection. Positive lymphocyte proliferation and cytokine responses to PPD-M and ESAT-6 were observed throughout the infection period studied. In contrast, responses to all other antigens were more variable and were not constantly present, suggesting that antigen cocktails rather than individual antigens should be used for immunodiagnosis. The detection of cytokine responses in the absence of lymphocyte proliferation, particularly during the early stages of infection, suggests a role for antigen-specific cytokine readout systems in the early identification of M. bovis infection in cattle.

Animals↗
PubMed2000

Frequencies of certain complement protein alleles and serum levels of anti-heat-shock protein antibodies in cerebrovascular diseases.

BACKGROUND AND PURPOSE: A strong correlation exists between the intensity of atherosclerotic alterations in different arteries. Marked differences exist, however, in the age and sex distribution and risk factors for coronary heart disease (CHD) and cerebrovascular disease (CVD). We therefore performed genetic and immunologic studies in patients with CVD. METHODS: We studied 292 patients with CVD (stroke or transient ischemic attack) and as control either 198 healthy blood donors and 485 healthy elderly (aged >60 years) people (genetic study) or 94 blood donors aged 45 to 60 years and 49 healthy elderly (aged >60 years) people (anti-heat-shock protein [hsp] measurements). Allele frequencies of 3 genes (C4A, C4B, and C3) encoding proteins of the complement system were determined by electrophoresis and immunofixation. Serum concentration of autoantibodies against 60-kDa heat-shock protein (anti-hsp60) was measured by the enzyme-linked immunosorbent assay method. RESULTS: Marked differences were observed between CVD patients and controls in the genetic studies. In the CVD patients aged >60 years, the frequency (11.3%) of the deficient allele of the C4B gene (C4B*Q0) was significantly (P:=0.0003) higher than that of the healthy controls (5.4%). By contrast, in the group aged 45 to 60 years, the frequency of the C4B*Q0 allele was lower in patients than in controls. Serum concentration of anti-hsp60 in the CVD patients did not differ from control values. CONCLUSIONS: In previous studies C4B*Q0 frequency was reported to be higher in CHD patients aged 45 to 60 years than in aged-matched controls. Moreover, high anti-hsp60 levels were found in CHD patients. These findings contrast with our present report of lower frequency of C4B*Q0 in CVD patients. Therefore, genetic and immunologic factors may at least partly explain the differences between the natural history and risk factors of CHD and CVD.

Cerebrovascular Disorders↗
PubMed2000

Histological changes to palatal and paratubal muscles in oral submucous fibrosis.

Oral submucous fibrosis (OSMF) is prevalent in the Indian subcontinent. In a large number of patients conductive deafness due to eustachian tube dysfunction has been found. The present study was, therefore, planned to assess the histopathological changes in palatal and paratubal muscles in oral submucous fibrosis. Incisional biopsy from the soft palate was taken in clinically proven cases of OSMF. In most of the cases, signs of chronic inflammation and fibrosis were seen in the submucosa. Dysplasia was noticed in seven (13.2 per cent) patients. Degenerative changes in palatal/paratubal muscles were found in the form of loss of cross striations in seven (13.2 per cent), oedematous muscle fibres in five (9.4 per cent) and atrophy in five (9.4 per cent) cases. It was concluded that there was definite involvement of palatal and paratubal muscles in OSMF. This could explain the eustachian tube dysfunction in these patients.

Ear Diseases↗
PubMed2000

Na+/H+ exchanger: an emerging therapeutic target in cardiovascular disorders.

Six isoforms of Na(+)/H(+) exchanger (NHE) have been identified to date. The NHE-1 isoform is expressed on the plasma membrane of cardiomyocytes and is involved in the regulation of intracellular pH and cell volume under normal physiological conditions. Myocardial ischemia-reperfusion is reported to strongly activate NHE-1. NHE-1 activation is postulated to contribute to myocardial injury by Ca(2+) overload. Several amiloride analogs non-selectively inhibit all isoforms of NHE and have been demonstrated to confer cardioprotection against ischemia-reperfusion injury in a number of experimental models with infarction, contractility, enzyme release and arrhythmias as endpoint. Recently, several selective inhibitors of the NHE-1 isoform have been synthesized and tested for their cardioprotective effect in animal models of ischemia-reperfusion injury. Cariporide and eniporide are currently being evaluated in phase II clinical trials for their antiischemic efficacy. NHE activity is reported to be altered in lymphocytes and vascular smooth muscle cells of spontaneously hypertensive rats and hypertensive patients. However, further research is required to clarify the role of NHE in the pathogenesis of hypertension. Several mitogenic stimuli are reported to activate NHE. Results of studies evaluating the effect of NHE inhibitors on postinfarction-induced cardiac remodeling in animals are promising. Further investigations are being carried out to highlight the involvement of NHE in cardiac hypertrophy. Based on the available data, it can be suggested that NHE has emerged as a useful target site in myocardial ischemia and may become a novel site for pharmacological modulation in hypertension and cardiac hypertrophy.

Journal Article↗
PubMed2000

Structure-activity relationship of chemical penetration enhancers in transdermal drug delivery.

Transdermal drug delivery (TDD) is the administration of therapeutic agents through intact skin for systemic effect. TDD offers several advantages over the conventional dosage forms such as tablets, capsules and injections. Currently there are about eight drugs marketed as transdermal patches. Examples of such products include nitroglycerin (angina pectoris), clonidine (hypertension), scopolamine (motion sickness), nicotine (smoking cessation), fentanil (pain) and estradiol (estrogen deficiency). Since skin is an excellent barrier for drug transport, only potent drugs with appropriate physicochemical properties (low molecular weight, adequate solubility in aqueous and non-aqueous solvents, etc) are suitable candidates for transdermal delivery. Penetration enhancement technology is a challenging development that would increase significantly the number of drugs available for transdermal administration. The permeation of drugs through skin can be enhanced by physical methods such as iontophoresis (application of low level electric current) and phonophoresis (use of ultra sound energy) and by chemical penetration enhancers (CPE). In this review, we have discussed about the CPE which have been investigated for TDD. CPE are compounds that enhance the permeation of drugs across the skin. The CPE increase skin permeability by reversibly altering the physicochemical nature of the stratum corneum, the outer most layer of skin, to reduce its diffusional resistance. These compounds increase skin permeability also by increasing the partition coefficient of the drug into the skin and by increasing the thermodynamic activity of the drug in the vehicle. This review compiles the various CPE used for the enhancement of TDD, the mechanism of action of different chemical enhancers and the structure-activity relationship of selected and extensively studied enhancers such as fatty acids, fatty alcohols and terpenes. Based on the chemical structure of penetration enhancers (such as chain length, polarity, level of unsaturation and presence of some special groups such as ketones), the interaction between the stratum corneum and penetration enhancers may vary which will result in significant differences in penetration enhancement. Our review also discusses the various factors to be considered in the selection of an appropriate penetration enhancer for the development of transdermal delivery systems.

Administration, Cutaneous↗
PubMed2000

Noninvasive revascularization by enhanced external counterpulsation: a case study and literature review.

Nearly 8 million people in the United States suffer from symptoms of coronary artery disease (CAD). Unfortunately, the population of patients with ischemic coronary disease that is not readily amenable to surgical or percutaneous revascularization continues to grow. For patients who are not candidates for standard revascularization procedures and in whom aggressive medical therapy fails to control symptoms, enhanced external counterpulsation (EECP) is a new, noninvasive outpatient method to improve quality of life by decreasing ischemic symptoms and permit increased activity. We report the case of a 56-year-old woman with severe, symptomatic CAD receiving maximal medical therapy who underwent a course of EECP therapy because she was not a good candidate for other forms of revascularization. She demonstrated dramatic improvement in her anginal symptoms and complete resolution of myocardial ischemia on repeat nuclear stress imaging. This case suggests that EECP is a safe and effective method for reducing symptoms of myocardial ischemia in patients for whom standard percutaneous or surgical revascularization is not suitable treatment.

Activities of Daily Living↗
PubMed2000

A double-blind placebo-controlled study on prophylactic use of cisapride on feed intolerance and gastric emptying in preterm neonates.

OBJECTIVE: To evaluate whether prophylactic use of cisapride will reduce the incidence of feed intolerance and gastro-esophageal reflux, and improve gastric emptying in early neonatal period in preterm babies. DESIGN: Double blind randomized controlled trial. SETTING: Hospital based. SUBJECTS: Forty nine preterm babies between 29-34 weeks of gestation were administered either cisapride or placebo. METHODS: Babies were enrolled in the study once they reached 30 ml/kg/day of enteral feeding or when 25% of total fluid intake was received through the enteral route. Those with sepsis, congenital malformations and on aminophylline were excluded. The subjects were randomized to receive either cisapride or placebo in a dose of 0.2 mg/kg/dose every 8 hourly for 14 days or till discharge. During the study period babies were observed for clinical signs of feed intolerance as judged by increase in abdominal girth, increased prefeed gastric residuals or vomiting. Gastro-esophageal reflux and gastric emptying time was assessed by Technetium phytate scan on day 7 +/- 1. RESULTS: Feed intolerance was noticed in 59% of study and 41% of control population. No significant difference was noticed in the two groups in the total number of episodes of feed intolerance (1.54 +/- 2.4 vs 1.18 +/- 1.6). Nearly 50% of babies in each group had gastro-esophageal reflux. Gastric emptying time (mean (SD) and median) was found to be comparable (p = 0.70) in those on drug and placebo (58.1 (32.2 min) 48.8 min) vs (53.8 (34.6 min) 43.4 min). CONCLUSION: Cisapride does not reduce the incidence of feed intolerance, gastro-esophageal reflux and does not improve gastric emptying in normal preterm neonates.

Cisapride↗