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Biomedical subjects

N B Singh

Publications and source records attributed to N B Singh.

At least 37 records · Page 2Linked to original sources
PubMed1993

Angiotensin converting enzyme activity in female reproductive tract of domestic fowl (Gallus domesticus) and its interactions with semen.

Presence of angiotensin converting enzyme (ACE, EC 3.4.15.1) in female reproductive tract and its interaction with semen has been investigated in domestic fowl. Higher activity of ACE was detected in homogenates of infundibulum region followed by magnum and relatively low level was noticed in rest of the parts of the oviduct (i.e. isthmus, uterus, uterovaginal-junction and vagina). This decreasing order in ACE activity was, however, reversed when these segments were incubated with semen. ACE in the ovarian follicular wall increased with corresponding increase in the follicle size. Presence of some stimulatory or inhibitory substances for ACE in the oviduct of fowl is suggested.

Animals↗
PubMed1993

Elective induction versus spontaneous labor after sonographic diagnosis of fetal macrosomia.

OBJECTIVE: To test the hypothesis that elective induction of labor, compared to spontaneous labor, reduces the cesarean rate in women with a sonographic diagnosis of fetal macrosomia. METHODS: Sonography results over a period of 27 months were used to select 262 consecutive patients who met the following inclusion criteria: singleton pregnancy at term, estimated fetal weight (EFW) at the 90th percentile or greater, and delivery at our institution. The subjects were divided into four groups based on obstetric management: spontaneous labor (N = 115), elective induction of labor with macrosomia as the sole indication (N = 44), induction of labor for other maternal or fetal indications (N = 48), and elective cesarean delivery (N = 55). The analysis focused on the first two groups. These were compared regarding cesarean rate, indications for cesarean, and shoulder dystocia rate. Multiple logistic regression was used to control for potential confounders. RESULTS: With elective induction, the cesarean rate was 57%, significantly higher than the 31% rate with spontaneous labor (P < .01). The induced group also had a significantly higher EFW and birth weight. When logistic regression was used to control for birth weight, parity, and care provider, elective induction was still associated with a higher risk of cesarean delivery than was spontaneous labor (adjusted odds ratio 2.7, 95% confidence interval 1.2-5.9; P < .02). Shoulder dystocia occurred in one of 19 vaginal deliveries with elective induction (5.3%) and in two of 79 with spontaneous labor (2.5%). CONCLUSION: Because elective induction of labor increased the cesarean rate and did not prevent shoulder dystocia, we conclude that mothers with macrosomic fetuses can safely be managed expectantly unless there is a medical indication for induction.

Adult↗
PubMed1991

Detection of M. leprae-specific antigens with dot-ELISA in urine and nasal samples from leprosy patients.

One-hundred-two urine and nasal samples collected from leprosy patients of different classifications of disease were studied for the presence of Mycobacterium leprae antigens, including phenolic glycolipid-I (PGL-I). Lipids were extracted from the urine samples, and nasal washings were concentrated and used as such in the dot-ELISA. Two types of primary antibodies, a polyclonal antibody obtained from lepromatous (LL) leprosy patients' pooled and absorbed sera and an anti-PGL-I monoclonal antibody, were used for the detection of M. leprae antigens from these samples. The polyclonal sera detected 23% to 36% of the paucibacillary (PB) and 100% of the multibacillary (MB) leprosy cases from the urine samples. Corresponding values for nasal detection were 10% to 18% for PB and 100% for MB cases. The monoclonal antibody against PGL-I could not detect tuberculoid (TT) leprosy cases. From the urine samples, however, 16% of the borderline tuberculoid (BT), 25% of the borderline (BB), 80% of the borderline lepromatous (BL), and 100% of the LL leprosy cases were detectable. It was interesting to note that PB, skin-smear negative cases were detectable from urine examination. The specificity and sensitivity of the test is discussed in relation to the crossreacting antigens.

Adolescent↗
PubMed1990

The specific 18-kilodalton antigen of Mycobacterium leprae is present in Mycobacterium habana and functions as a heat-shock protein.

A mAb previously thought to be specific for Mycobacterium leprae has been found to cross-react with a cultivable mycobacterium, Mycobacterium habana TMC5135. The epitope is present on a protein of identical molecular mass (18 kDa) in both species. When M. habana is subjected to heat shock, expression of the protein is significantly increased, whereas other forms of environmental stress do not increase its expression. Since immunization of mice with M. habana results in protection against infection with M. leprae, the possibility of using a molecular genetic approach to investigate the role of this protein in protective immunity is raised.

Antibodies, Bacterial↗
PubMed1990

Enterovirus-specific serum IgA antibody responses in patients with acute infections, chronic cardiac disease, and recently diagnosed insulin-dependent diabetes mellitus.

Employing an antibody class capture ELISA, we assessed the significance of enterovirus (EV)-specific serum IgA (EV-IgA) as a marker of EV infection. EV-IgA was detectable in 64% of sera from patients with acute illnesses which may be attributable to EV infection who also had EV-IgM, but also in 30% of sera from patients without evidence of EV infection. High EV-IgA levels were more closely associated with the presence of EV-IgM and were demonstrable in 39% of patients with acute infections who were EV-IgM positive, compared to 3% of those who were EV-IgM negative. Among patients with acute EV infection confirmed by virus isolation, EV-IgA was present in 67% and EV-IgM was present in 83%. As a marker of acute EV infection, EV-IgA is less sensitive and less specific than EV-IgM. EV-IgA responses in patients with chronic cardiac disease paralleled EV-IgM responses in some cases but there was no significant association between these two antibody responses in this group as a whole. High EV-IgA responses were present in 20% of EV-IgM positive and 21% of EV-IgM negative patients, and may persist as a result of an immunoregulatory defect leading to virus or antigen persistence at mucosal surfaces. High EV-IgA levels were also detectable in 33% of EV-IgM positive newly diagnosed insulin-dependent diabetics but in none who were EV-IgM negative, which suggests that most EV infections in these patient were acute rather than persistent.

Acute Disease↗
PubMed1990

Variation in angiotensin-converting enzyme activity in the testes of prepubertal, pubertal and adult cockerels.

The variation in the level of angiotensin-converting enzyme in the testes of prepubertal, pubertal and adult cockerels were investigated. Maximum levels of angiotensin-converting enzyme were observed at 8 wk of age, followed by a progressive decrease (P/0.01) until 14 wk of age. After this stage, however, a rapid growth rate of the testes and comb was noted. The concentration of angiotensin-converting enzyme in pubertal and adult birds remained at a significantly lower level than in the prepubertal birds. The level of activity of this enzyme was significantly but negatively correlated with age and with the weights of the testes and comb. The high level of this enzyme found in prepubertal cockerels suggests it may be more highly involved in the early rather than later stages of spermatogenesis.

Journal Article↗
PubMed1990

Effects of cyproterone acetate and testosterone treatments on some physical parameters, angiotensin converting enzyme activity and fertilizing ability of spermatozoa of domestic cocks (Gallus domesticus).

Healthy adult cocks were administered through the intramuscular route with 1 or 15 mg cyproterone acetate (CyA)/kg b. wt. or testosterone at the rate of 1.5 mg/kg b. wt. daily for a period of 25 days. High doses of CyA and testosterone caused severe suppression (P less than 0.01) of semen volume, sperm concentration, sperm motility and angiotensin converting enzyme activity (ACE EC 3.4.15.1). Fertilizing ability of spermatozoa was also reduced drastically at the end of treatment period. No loss of sexual behaviour was observed in treated birds as compared to controls. Recovery in all parameters from deleterious effects of these drugs was rapid after cessation of treatment. Lower doses of CyA did not affect the parameters of semen. The results are discussed in relation to the possible mechanism of action of CyA and testosterone.

Animals↗
PubMed1989

Vaccination of mice against Mycobacterium leprae infection.

Intradermal immunization with killed Mycobacterium leprae renders mice immune to infection with viable M. leprae. This protection is long lasting and systemic in that immunization in the left flank results in protection in both the left and right footpads. Immunization with Mycobacterium vaccae was ineffective in protecting mice against M. leprae infection, while Mycobacterium bovis BCG provided partial protection. Mycobacterium habana TMC 5135 (now known as Mycobacterium simiae) was found to be as effective as M. leprae in protecting mice against footpad infection.

Animals↗
PubMed1988

Detection of leprosy antigenuria through DOT-ELISA.

Fifty-five samples of urine from different grades of leprosy patients and normal persons were processed for detection of PGL-1 antigen through DOT-ELISA on nitrocellulose paper strips using anti-human IgG horse raddish peroxidaseconjugate. About 66.6% of the paucibacillary and 100% of the multibacillary leprosy cases were detectable through this technique on the basis of differential colour development on the strips. Possibility of its use in the field conditions has been discussed.

Antigens, Bacterial↗
PubMed1988

Use of non-conventional antigen: M. habana in detecting M. leprae antibodies from leprosy patients and contacts in FLA-ABS test.

An indirect immunofluorescent (FLA-ABS) test has been developed to detect M. leprae specific antibodies in the active and subclinical cases of leprosy. An antigenically related mycobacterium, M. habana, was used as an antigen to detect M. leprae specific antibodies in the sera samples of leprosy patients. A comparison was made with M. leprae antigen using same set of sera samples. M. habana is capable of detecting anti-M. leprae antibodies in the serum samples of leprosy patients, previously absorbed with various mycobacterial antigens, cardiolipin and lecithin, almost to the same percentage as M. leprae. Possible use of M. habana antigen as an alternative to M. leprae, in the serodiagnosis of leprosy, has been discussed.

Antibodies, Bacterial↗
PubMed1988

Relative cross reactivity of habanin, lepromin and tuberculin in guinea pigs sensitized with homologous and heterologous mycobacteria.

An atypical strain Mycobacterium habana has been studied for its antigenic cross reactivity with delayed type of hypersensitivity responses in guinea pigs. Guinea pigs sensitized with M. habana, M. leprae and M. tuberculosis when challenged with habanin, lepromin and tuberculin in criss-cross fashion have demonstrated strong cross reactivity with each other. Possibilities of developing M. habana as a vaccine against tuberculosis and/or leprosy has been discussed.

Animals↗