PubMed Health⌕ Search

Biomedical subjects

M Bhatnagar

Publications and source records attributed to M Bhatnagar.

At least 19 recordsLinked to original sources
PubMed2004

Physiology of Anabaena khannae and Chlorococcum humicola under fluoride stress.

Sodium fluoride showed pH-dependent physiological responses in the two test microalgae Anabaena khannae and Chlorococcum humicola. A. khannae showed severe membrane damage with fluoride at low pH with leakage of pigments and electrolytes. Annihilation of photosynthesis along with inhibition in 14C uptake was observed at pH 6 with 50 mg/L fluoride. While respiration was less affected in the cyanobacterium, C. humicola showed 30 % inhibition in respiratory activity. Resistance of C. humicola to fluoride toxicity has been attributed to the hindrance provided by the thick cell envelope, intracellular compartmentation and increase in extracellular pH as a consequence of its metabolism.

Anabaena↗
PubMed2001

Distribution of somatostatin (SS) immunoreactivity using specific rabbit antibodies in preoptic-anterior hypothalamus (PO-AH) of female rat brain.

Distribution of somatostatin (SS) immunoreactivity was observed in the preoptic-anterior hypothalamus (PO-AH) of the female rat brain. Six specific rabbit antibodies A (SS-14), B (SS-28), C (SS-28 complete), D (SS 14 and SS-28 both), E (SS preprohormone) and F (GHRH) were used for immunostaining using Avidin-Biotin Complex (ABC) method (Hsu et al., 1981). Immunostaining was observed with all the six antibodies, in the serial sections passing through various bregma levels (-0.3 to -3.3 mm) of preoptic-anterior hypothalamic (PO-AH) region including median eminence (ME). In conclusion, the present study suggests that immunoreactive nerve terminals for both SS-14 and SS-28 are present in internal (IZ) and external zones (EZ) of ME. High intensity of SS-14 and SS-28 containing terminals in EZ suggests that both SS fractions are involved in regulating GH secretion in anterior pituitary. This is a first report on comparative distribution of immunoreactivities of four different fractions of SS, SS-preprohormone and GHRH in PO-AH.

Animals↗
PubMed2001

Neuroprotective effects of Withania somnifera Dunn. in hippocampal sub-regions of female albino rat.

The neuroprotective effects of W. somnifera were studied on stressed adult female Swiss albino rats. Experimental rats were subjected to immobilization stress for 14 h and were treated with a root powder extract of W. somnifera available as Stresscom capsules (Dabur India Ltd). Control rats were maintained in completely, non stressed conditions. Thionin stained serial coronal sections (7 microm) of brain passing through the hippocampal region of stressed rats (E(1) group) demonstrated 85% degenerating cells (dark cells and pyknotic cells) in the CA(2) and CA(3) sub-areas. Treatment with W. somnifera root powder extract significantly reduced (80%) the number of degenerating cells in both the areas. The study thus demonstrates the antistress neuroprotective effects of W. somnifera.

Animals↗
PubMed2000

Anemia in children: early iron supplementation.

Iron deficiency anemia is the most wide spread micronutrient deficiency disorder in the world, being most prevalent in women and young children. The present study was conducted to find out the prevalence of anemia in children and its contributory factors with reference to early iron supplementation. It was a cross sectional study done on 137 children of age 1-2 years in urban slums of Meerut. Prevalence of anemia in the study group was 59.9%. The socio-economic status, mother's educational status, birth weight, sibling order, and type of weaning food did not show any significant relationship with the prevalence of anemia in these children, whereas, weaning time, nutritional status and early iron supplementation had a positive impact on it. Exclusive breast feeding upto 4 months followed by weaning, adequate nutritional status and early iron supplementation have a definite role in prevention of anemia in children.

Age Factors↗
PubMed2000

Gluco- and mineralocorticoid receptor-mediated regulation of neurotrophic factor gene expression in the dorsal hippocampus and the neocortex of the rat.

Gluco- and mineralocorticoid receptors (GR and MR) act via common promoter elements but may exert different effects on gene regulation in various regions of the forebrain. In order to separately analyse the role of GR and MR in the regulation of neurotrophic factor genes and their receptors, we used adrenalectomy and subsequent hormone injections in the rat as a model system. Twenty-four hours after adrenalectomy rats were injected with a single dose of corticosterone (2 and 10 mg/kg), aldosterone (0.5 mg/kg) or the synthetic glucocorticoid agonist RU 28362 (4 mg/kg). Gene expression of basic fibroblast growth factor (bFGF) and its high-affinity receptors [fibroblast growth factor receptor subtypes 1-3 (FGF-R1, FGF-R2, FGF-R3)], as well as brain-derived growth factor (BDNF) and neurotrophin-3 (NT-3) was analysed at 4 h after the hormone injection in CA1-CA4 (cornus of Ammon areas of the hippocampus) and dentate gyrus of the dorsal hippocampus and in neocortex by means of in situ hybridization. We found that bFGF is regulated in CA2, CA3 and dentate gyrus by GR and MR together, and in CA1, CA4 and neocortex by GR alone. FGF-R2 expression in the hippocampus seems to be regulated only by MR, while BDNF expression appears to depend on both receptors. FGF-R1, FGF-R3 and NT-3 were only moderately affected by the hormone activation of GR and MR acting in concert or alone in the various regions. Thus, the present findings suggest that the adrenal cortical system through GR and MR participate in the control of neurotrophic factor signalling in a highly subregion- and cellular-dependent manner.

Adrenalectomy↗
PubMed2000

Stress induced neuron degeneration and protective effects of Semecarpus anacardium Linn. and Withania somnifera Dunn. in hippocampus of albino rats: an ultrastructural study.

Effects of herbal formulations were studied on hippocampal neuron cell bodies. Study was carried out in adult Swiss albino rats. Experimental rats (E) were divided into three groups. Group E1 rats were given immobilization stress for 14 hr/day for 30 days. Rats in E2 and E3 group were given daily single dose (40 mg/kg/body wt.) of alcoholic extract of S. anacardium and W. somnifera. After 1 hr giving the plant extract, the rats were subjected to stress. Treatment continued for 14 hr for 30 days. Control rats were kept in complete nonstress condition. Ultrastructural characteristics of neuron cell bodies in hippocampal sublayer (CA1-CA4 and Dg) was studied in rats of E1, E2 and E3 groups and compared with control. Results of the present study demonstrated, that both CA2 and Dg, 85% of neuron cell bodies exhibited degenerating characteristics, (which includes karyorrhexis, membrane blebbing, chromatin condensation, chromatin fragmentation and intracellular spacing). Interestingly, after the treatment with S. ancardium cells demonstrating degenerating characteristics was significantly reduced (80%) as compared to treatment with W. somnifera. Study suggests that probably both the herbal drugs have cytoprotective properties.

Animals↗
PubMed1999

Low-dose midazolam infusion for oculoplastic surgery under local anesthesia.

PURPOSE: Oculoplastic surgery with infiltration of local anaesthesia at the operative site performed as a day-case procedure is both efficient and cost-effective. Patients considered unsuitable for this because of fear or apprehension may, however, benefit from per-operative conscious sedation. We sought to study the efficacy and safety of this using midazolam, a water-soluble benzodiazepine. METHOD: We have performed a controlled clinical trial comparing the effect of a low-dose intravenous infusion of midazolam (0.2 mg/ml of normal saline at a rate of 1 mg/h) with saline placebo on 48 subjects undergoing oculoplastic surgery with local anaesthesia. Patients were given pre- and post-operative questionnaires assessing, amongst other factors, anxiety levels, pain, degree of reported amnesia and psychomotor recovery. RESULTS: Using the low-dose midazolam infusion no adverse cardiorespiratory reactions occurred. Patients receiving midazolam reported remembering significantly less about their operation than controls (p = 0.04) and showed significantly lower state-anxiety after their operation than before (p < 0.02). This change was not noted in the placebo group. There was no significant difference in the psychomotor performance of patients given midazolam compared with controls 2 h after surgery. CONCLUSIONS: A low-dose continuous infusion of midazolam can be used to safely provide effective anxiolysis and conscious sedation with good psychomotor recovery during oculoplastic procedures in a day-case setting.

Adolescent↗
PubMed1999

Somatostatin (SRIF) like immunoreactivity in median eminence (ME) of female rat brain: evidence of compartmentalization in ME.

Somatostatin (SRIF) immunoreactivity was observed in rostrocaudal extent (Bregma levels-1.8 mm to -3.8 mm) of the median eminence (ME) in female rat brain using Avidin-Biotin Complex (ABC) method (Hsu et al, 1981). SRIF immunoreactivity (IR) was observed in entire-rostrocaudal extent of both internal (IZ) and external zone (EZ) of ME. Image analysis of SRIF stained sections showed that in rostral ME (Bregma -1.8 to -2.3 mm) dense immunoreactive nerve terminals were observed in EZ. In medial ME (Bregma -2.3 mm to 3.3 mm) SRIF-IR was low in IZ and dense in EZ. In this region dense immunoreactive nerve terminals were observed in lateral margin of EZ. In caudal ME (Bregma -3.3 mm to -3.8 mm) nerve terminals in lateral EZ and median IZ and EZ showed dense reactivity in nerve terminals. These results led us to hypothesize that each region-lateral IZ and EZ and medial IZ and EZ are independent functional units in ME. Six functionally independent compartments could be identified-Compartment I and III of IZ and IV in EZ (Lateral margins in ME), Compartment V (IZ) and Compartment VI (medial EZ).

Animals↗
PubMed1999

Reproductive tract infections among rural women in Meerut.

The present study was done among 500 women of reproductive age group. Study revealed overall prevalence rate of RTI of 44.8%. Excessive vaginal discharge was the most common presenting symptom (42.0%). Inspite of such an high prevalence of reproductive tract infections, only 22.8% of the women sought treatment for their problem. The study suggests to improve the awareness about RTI and its treatment facility among women and also recommends to develop a strategy to train and reorient the health personnel.

Adolescent↗
PubMed1997

Poliomyelitis in western Uttar Pradesh.

The studies on prevalence of lameness in Western Uttar Pradesh revealed the overall poliomyelitis prevalence rate of 6.47/1000 children and an annual incidence rate of 19.3 per lac population with an average age of onset at 17.2 months. The overall OPV coverage was 53.2% with a vaccine efficacy of 94.2%. The incidence of poliomyelitis was negatively correlated to OPV immunization strongly suggesting the need of achieving high level of OPV coverage as a first step for eradication of poliomyelitis.

Child↗
PubMed1996

On the role of glucocorticoid receptors in brain plasticity.

1. The mapping of glucocorticoid receptors (GR) in the rat central nervous system (CNS) has demonstrated their widespread presence in large numbers of nerve and glial cell populations also outside the classical stress regions. 2. The present paper summarizes the evidence that glucocorticoids via GR in the CNS can act as lifelong organizing signals from development to aging. The following examples are given. (a) In the prepubertal and adult offspring, prenatal corticosterone treatment can produce long-lasting changes in striatal dopaminergic communication. (b) In adulthood, the evidence suggests complex regulation by adrenocortical hormones of neurotrophic factors and their receptors in the hippocampal formation. (c) In aging, the strongly GR-immunoreactive pyramidal cell layer of the CA1 hippocampal area appears to be preferentially vulnerable to neurotoxic actions of glucocorticoids, especially in some rat strains. 3. Strong evidence suggests that each nerve cell in the CNS is supported by a trophic unit, consisting of other nerve cells and glial cells, blood vessels, and extracellular matrix molecules. Due to multiple actions on nerve and glial cell populations of the different trophic units, the glucocorticoids may exert either an overall trophic or a neurotoxic action. It seems likely that with increasing age, the endangering actions of glucocorticoids on nerve cells prevail over the neurotrophic ones, leading to reduced nerve cell survival in some trophic units.

Adrenal Cortex Hormones↗
PubMed1995

Neurotensin-like immunoreactivity in odontoblasts and their processes in rat maxillary molar teeth and the effect of pulpotomy.

A strong neurotensin-like immunoreactivity (NT-like IR) was detected in the odontoblast cells of the rat teeth. 4 h after a partial pulpotomy performed in two maxillary molar teeth a decreased NT-like IR was observed in the odontoblast layer located at the vicinity of the lesion together with edema and nuclear pyknosis. NT-like IR became further decreased after 24 h. After 7 days NT-like IR had almost fully disappeared with signs of necrosis of the dental pulp and infiltration of polymorphonuclear lymphocytes. It seems possible that NT like peptides in the odontoblast cell layer may play a role, e.g., in dentinogenesis and/or nociception.

Animals↗
PubMed1995

Immunocytochemical detection of ornithine decarboxylase (ODC) in paraffin-embedded tissues as a possible prognostic indicator for oral lesions.

Intracellular levels of ornithine decarboxylase (ODC) are raised following mitogenic stimulus and in neoplasia. Because lesions of the oral cavity are often difficult to assess histologically, we have determined the value of immunocytochemical detection of ODC as a prognostic indicator in 74 routinely fixed and paraffin-embedded oral biopsies using peroxidase-antiperoxidase and immunogold-silver staining. The latter proved more sensitive, yielding positive reactions in 32 of 43 oral carcinomas (11/14 well differentiated, 16/21 moderately differentiated and 3/5 poorly differentiated) and 7/11 potentially malignant lesions, compared with 19/45 carcinomas and 1/15 potentially malignant lesions, by peroxidase anti-peroxidase. Hyperplastic lesions (n = 7) and normal non-keratinized buccal mucosa (n = 7) were all negative. Follow-up was possible in 13 of the carcinoma patients. Of 7 positive ODC reactions but clinically node-free at biopsy, 2 died and 2 had recurrences within 3 years, whereas all of 6 with no immunoreactivity were symptom-free after 3-5 years. Immunostaining for ODC may be helpful for the prognostic assessment of routinely processed oral lesions and in choosing treatment.

Animals↗
PubMed1994

Glial and neuronal glucocorticoid receptor immunoreactive cell populations in developing, adult, and aging brain.

A detailed mapping of glucocorticoid receptor (GR) immunoreactivity (IR) in rat CNS was performed employing a mouse monoclonal antibody against rat liver GR. Subjective comparisons were made between the present results and the available data in the literature. A semiquantitation of GR immunostaining was found necessary and was obtained by microdensitometric and morphometric techniques, which enabled the distinction of neuronal and glial cell populations containing GR IR in various CNS regions. GR IR in the CNS was mainly found in the nuclear compartment. The GR was present in neuronal populations with classical neurotransmitters, especially monoamines and glutamate and with various neuropeptides. The degree of colocalization varied according to the function of the brain area. Functional implications were made in relation to stress sensitivity, mood and nociception/antinociception. The global control of networks by glucocorticoids may allow an optimal integration of different types of circuits. The GR is found already in the fetal rat and the development of GR mRNA and receptor protein was followed during the pre- and postnatal periods. The GR appears to be a major factor in brain maturation and in modulation of stress responses. In aged Brown Norway rat brain GR IR but not mineralocorticoid receptor (MR) IR is reduced in the hippocampal nerve cells. The intensity of GR IR but not the number of nerve cells is altered, indicating a reduced activation of the GR in aging in this rat strain. Overall GR participates in neuronal plasticity from fetal and postnatal life to adult life and aging.

Aging↗
PubMed1993

Fluoride toxicity: a biochemical and scanning electron microscopic study of enamel surface of rabbit teeth.

The present study has been carried out to investigate the effect of fluoride toxicity on the morphology as well as inorganic chemical constituents of rabbit teeth. Rabbits were administered sodium fluoride at a dose of 10 mg NaF/kg body weight every 24 h for 18 and 23 months. The incisor and molar teeth (whole tooth) were investigated for fluoride, calcium and phosphorus content in 18- and 23-month treated animals. The enamel surfaces of incisor teeth of 23-month treated animals were examined under scanning electron microscope. A significant increase in fluoride levels and significant decrease in calcium content was found following fluoride administration for 18 and 23 months as compared to control. Ca/P ratio was significantly increased only in 23-month treated animals. The scanning electron micrographs revealed hypoplastic, rough, uneven, pitted and cracked enamel surfaces covered with granular deposits as a result of excessive intake of fluoride. It can be concluded that long term fluoride administration leads to severe structural alterations on the enamel surface, possibly through defective mineralization.

Animals↗