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Biomedical subjects

M Singh

Publications and source records attributed to M Singh.

At least 757 records · Page 42Linked to original sources
PubMed1991

Reconstruction of out-of-plane cardiac displacement patterns as observed on the chest wall during various phases of ECG by capacitance transducer.

The out-of-plane displacements due to cardiac action have been measured on the chest wall by an electronic distance measurement technique which is based on the variation of the capacitance between the probe and moving surface. The displacements were measured at 36 locations over the entire cardiac region along with ECG and were directly fed to an IBM PC/AT computer after A/D conversion. From these data, the displacement patterns for the whole region during the complete cardiac cycle could be reconstructed in a perspective view. The sequential analyses of the displacements shows the details of the cardiac events and the results obtained are in agreement with other techniques. The averaged displacements over various regions of the heart for normal subjects have also been presented.

Analog-Digital Conversion↗
PubMed1991

Reconstruction of sequential cardiac in-plane displacement patterns on the chest wall by laser speckle interferometry.

Time-average speckle interferometry has been applied to obtain displacement patterns on the chest wall produced by cardiac action, in the absence of breathing, during various phases of the cardiac cycle. This has been achieved by an electronic shutter, controlled by the electrocardiogram of the subject. The recorded holographic plates processed under identical conditions are scanned by the pointwise method to obtain the absolute displacements at various locations corresponding to the activities of the various cardiac chambers and values. These data are transformed to a 40 x 30 matrix by an interpolation method and, from this, three-dimensional displacement plots are reconstructed by an IBM PC/AT computer. These patterns shown the displacements over the entire cardiac area corresponding to the activities of various regions during the cardiac cycle. The apex and aortic valve areas show the maximum displacements during the systolic phase. During the diastolic phase the activities over the low pressure atrial regions are also observed. The results obtained outline the functional details of the normal heart and the activities over various areas are in agreement with that of other noncontact techniques.

Algorithms↗
PubMed1991

Cytotoxicity of eugenol in sealer containing zinc-oxide.

In this study two zinc-oxide-based root canal sealers were compared for their tissue toxic response. The sealers tested were zinc-oxide eugenol and zinc-oxide glycerine. Fifteen albino rats were used for the study and were injected subcutaneously in the preset state. The tissue response was assessed by counting the polymorphonuclear cells at Day 1, Day 7 and Day 15 of the study period. The inflammatory response was graded according to the mean polymorphonuclear counts in the five rats for each period. The results showed that the toxicity was greater for the eugenol-containing sealer and increased during the three time intervals. For the non-eugenol sealer the response was milder and reached a peak by 7 days after which it decreased.

Animals↗
PubMed1991

Physiological effects of hydrogen sulfide inhalation during exercise in healthy men.

Occupational exposure to hydrogen sulfide (H2S) is prevalent in a variety of industries. H2S when inhaled 1) is oxidized into a sulfate or a thiosulfate by oxygen bound to hemoglobin and 2) suppresses aerobic metabolism by inhibiting cytochrome oxidase (c and aa3) activity in the electron transport chain. The purpose of this study was to examine the acute effects of oral inhalation of H2S on the physiological responses during graded cycle exercise performed to exhaustion in healthy male subjects. Sixteen volunteers were randomly exposed to 0 (control), 0.5, 2.0, and 5.0 ppm H2S on four separate occasions. Compared with the control values, the results indicated that the heart rate and expired ventilation were unaffected as a result of the H2S exposures during submaximal and maximal exercise. The oxygen uptake had a tendency to increase, whereas carbon dioxide output had a tendency to decrease as a result of the H2S exposures, but only the 5.0 ppm exposure resulted in a significantly higher maximum oxygen uptake. Blood lactate concentrations increased significantly during submaximal and maximal exercise as a result of the 5.0 ppm exposure. Despite these large increases in lactate concentration, the maximal power output of the subjects was not significantly altered as a result of the 5.0 ppm H2S exposure. It was concluded that healthy young male subjects could safely exercise at their maximum metabolic rates while breathing 5.0 ppm H2S without experiencing a significant reduction in their maximum physical work capacity during short-term incremental exercise.

Administration, Inhalation↗
PubMed1991

Endurance training decreases serum testosterone levels in men without change in luteinizing hormone pulsatile release.

Cross-sectional studies have suggested that total and bioavailable testosterone levels are reduced in some male athletes. Such changes may be related to loss of body weight, increased serum cortisol, and/or alterations in LH pulsatile release. To determine how endurance training may affect androgen levels, we measured serum total testosterone, sex hormone-binding globulin, free androgen index, LH, FSH, PRL, cortisol, and weight in 15 previously sedentary males. We also examined pulsatile LH release in a subset of 5 subjects. Over 6 months of training, the men increased weekly running mileage to an average of 56 km/week. Total testosterone and free androgen index levels decreased significantly. PRL and cortisol also decreased, while single sample LH and FSH remained unchanged. There was a significant reduction in weight, which did not correlate with changes in serum testosterone levels. LH pulsatile release was not altered by training in the subset of 5 runners. These data confirm previous findings of physiological reduction in serum testosterone and PRL levels and suggest that the testosterone decrease is not related to changes in LH pulsatile release, weight, or increased serum cortisol levels.

Adult↗
PubMed1991

Community support for young physically handicapped people.

This study examined the cost of home and hospital care for individuals who are severely physically handicapped and who may have many years to live. In addition to quantifying the overall level of these services and their costs, factors which might influence the level of service were identified and their use related to the diagnosis, duration and severity of disability, and number of unpaid carers. Costs of health and social service community support increased with severity of disability, and were mostly incurred by individuals with a Barthel score of less than 50 (more severe handicap). Costs, except for those individuals with cerebral palsy, were independent of the number of careers, and for those of school and university age the costs of special educational facilities were significant.

Adult↗
PubMed1991

A comparative study of PAP technique and in-situ molecular hybridization for identification of human papilloma viruses in cervical lesions.

The association of Human Papilloma Virus (HPV) with cervical lesions was correlated using peroxidase anti-peroxidase (PAP) technique and in-situ molecular hybridization (MH) with H3 labelled DNA probes (HPV type 6, 11, 16 and 18). The PAP technique to demonstrate capsid antigen and molecular hybridization for DNA sequences was studied in 30 cases. The correlation of HPV with cervical lesions was seen in 29.9% cases with PAP technique unlike 73.4% using M.H. technique, indicating the efficacy of the latter.

Carcinoma↗
PubMed1991

Serodiagnosis of melioidosis in Singapore by the indirect haemagglutination test.

Melioidosis is endemic in Singapore, with diagnosis dependent upon both bacteriological culture and serodiagnosis. Using the polysaccharide (melioidin)-sensitized turkey red cells in the indirect haemagglutination test (IHAT), 20 (100%) of the Pseudomonas pseudomallei culture-positive cases were detectable by the IHAT with titles ranging from 1:16 to 1:32, 768. Eight of these patients who died within a few days after the IHAT was performed had titres ranging from 1:16 to 1:1028. Five culture-negative patients, with clinical symptoms suggestive of melioidosis infection and who responded to treatment with ceftazidime, showed IHA titres between 1:64 and 1:8,192. One hundred and twenty one sera from patients with pneumonia, abscesses, or diabetes mellitus were IHAT negative. The IHAT showed good specificity since negative titres were seen in tests using sera from 2 patients with culture-positive Pseudomonas aeruginosa and 4 patients positive for Legionella. IHAT negative results were obtained from tests of 50 normal blood donors and 50 sewerage workers. Of 683 national servicemen tested, 5 (0.73%) had IHAT titres ranging from 1:16 to 1:128. Unlike hyperendemic areas such as Thailand where interpretation of IHAT is seriously hampered by IHA titres found in one-third to half of the population, serodiagnosis of melioidosis by the sensitive IHAT may be employed in Singapore as a routine procedure since background IHA titres are low.

Hemagglutination Tests↗
PubMed1991

A controlled study of sugar-fortified milk feeding for prevention of neonatal hypoglycaemia.

Healthy term, large for gestational age (LGA) infants (130) with blood sugar greater than 30 mg/dl at the age of less than 30 min were randomized into two groups. Group I (study group) babies received sugar-fortified milk formula while group II (control group) received standard milk formula. Milk was fed at a minimum of 80 ml/kg/24 h. The first feed was given within 45 min of birth and subsequently at 2 h of age and then 2 hourly till the age of 24 h. The blood sugar (initial within 30 min of birth) was monitored by dextrostix at the age of 2, 4, 12 and 24 h. The babies on fortified feeds received significantly (P less than 0.001) higher amount of carbohydrate (8.2 mg/kg/min) as compared to those on standard milk (5.2 mg/kg/min). The incidence of hypoglycaemia was reduced significantly (P less than 0.05) by the sugar fortified feeds. The mean blood sugar level in babies receiving fortified feeds was significantly (P less than 0.001) higher at all ages as compared to those receiving standard feeds. Nearly all the babies who subsequently developed hypoglycaemia had an earlier blood sugar level of less than 60 mg/dl. The study shows that sugar-fortified milk feeds are useful in preventing hypoglycaemia in LGA infants and should be routinely recommended in the special care neonatal units of developing countries especially when facilities for monitoring blood sugar are unsatisfactory or unavailable.

Animals↗
PubMed1991

Resistant coagulase negative staphylococci from clinical samples.

Antibiotic susceptibility testing against 17 antibiotics was done on 96 strains of various species of coagulase negative staphylococci by Stokes method. Hundred per cent sensitivity was found against vancomycin and cefotaxime and about 90 per cent against ciprofloxacin, clavulanate potentiated amoxycillin, cloxacillin and clindamycin. Strains showed highest resistance against cotrimoxazole (77.08%) and tetracycline (64.59%). Clavulanate potentiated amoxycillin was found to be highly active against penicillin, ampicillin and amoxycillin resistant organisms. The results highlight the importance of antibiotic resistance typing among coagulase negative staphylococci species which are increasingly being reported from serious clinical infections making empiric therapy and selection of antibiotics difficult in these infections.

Anti-Bacterial Agents↗
PubMed1991

Perinatal outcome of infants born to diabetic mothers.

Two hundred and sixty three pregnant diabetic mothers' perinatal outcome was evaluated. Two hundred and twenty five infants were born to gestational diabetic mothers (IGDM) and 38 infants to mothers with established diabetes mellitus (IDM). In IGDM group, 34 babies (15%) were preterm and 45 (20%) were low birth weight (less than 2500 g). Thirty eight babies (17%) were large-for-dates (LFD) and 14 (6.2%) were small-for-dates (SFD). Among IDM group, 8 (21%) babies were preterm and 8 (21%) were low birth weight (less than 2500 g). Fifteen babies (39.5%) were LFD and 3 (8%) were SFD. Out of all babies, hypoglycemia occurred in 43 (16%), birth asphyxia in 24 (9%) and respiratory distress in 21 (8%). Nearly half of respiratory distress were due to hyaline membrane disease. Perinatal mortality rate was significantly higher (p less than 0.001) in IDM (237/1000 live birth) as compared to IGDM (40/1000 live birth).

Congenital Abnormalities↗
PubMed1991

Antimicrobial efficacy of iodoformized zinc oxide-eugenol sealer on micro-organisms of root canal.

Iodoformized zinc oxide-eugenol was tested for its antibacterial effect against the aerobic and anaerobic bacteria obtained from the root canals of deciduous teeth; the bacteria were staph aureus, strep viridans, strep faecalis, bacteroides melaninogenicus and also mixed culture obtained from infected non-vital anterior teeth. The sensitivity was checked on BHI- agar plates employing well-method. Iodoformized zinc oxide eugenol paste was found to be effective for both the aerobic and anaerobic bacteria of the root canals of deciduous teeth with maximum sustaining period of 10 days; staphylococcus aureus was found to be the most susceptible, while Streptococcus faecalis the most resistant.

Bacteria↗