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Biomedical subjects

N S Rao

Publications and source records attributed to N S Rao.

At least 19 recordsLinked to original sources
PubMed2001

Quality of drinking water from ponds in villages of Kolleru Lake region.

Kolleru Lake is the largest natural freshwater lake in the districts of East and West Godavari of Andhra Pradesh. The major population centres in the Kolleru Lake region are the 148 villages of which 50 bed villages and 98 belt villages. All bed and belt villages in lake region have at least one drinking water pond. Drinking water ponds are filled with lake water during monsoon season and directly supplied to the public throughout the year. The water samples were collected from village drinking water ponds in a year by covering three seasons and analysed for different physico-chemical parameters to assess the quality of drinking water.

Environmental Monitoring↗
PubMed1998

Technique of removal of an impacted sharp object in a penetrating head injury using the lever principle.

Penetrating head injuries can be difficult to manage as the extensive surgery which may be required can result in severe morbidity and mortality in some patients. A conservative surgical approach with a "pull and see" policy was adopted successfully in a described case. Extraction can be achieved by using the mechanical advantage of the lever principle. By this method while removing the object any movements of sharp edges which will cause secondary damage can be reduced to a minimum.

Brain Injuries↗
PubMed1997

Nuclear magnetic resonance assignment and secondary structure of an ankyrin-like repeat-bearing protein: myotrophin.

Multidimensional heteronuclear NMR has been applied to the structural analysis of myotrophin, a novel protein identified from spontaneously hypertensive rat hearts and hypertrophic human hearts. Myotrophin has been shown to stimulate protein synthesis in myocytes and likely plays an important role in the initiation of cardiac hypertrophy, a major cause of mortality in humans. Recent cDNA cloning revealed that myotrophin has 11B amino acids containing 2.5 contiguous ANK repeats, a motif known to be involved in a wide range of macromolecular recognition. A series of two- and three-dimensional heteronuclear bond correlation NMR experiments have been performed on uniformly 15N-labeled or uniformly 15N/13C-labeled protein to obtain the 1H, 15N, and 13C chemical shift assignments. The secondary structure of myotrophin has been determined by a combination of NOEs, NH exchange data, 3JHN alpha coupling constants, and chemical shifts of 1H alpha, 13C alpha, and 13 C beta. The protein has been found to consist of seven helices, all connected by turns or loops. Six of the seven helices (all but the C-terminal helix) form three separate helix-turn-helix motifs. The two full ANK repeats in myotrophin are characteristic of multiple turns followed by a helix-turn-helix motif. A hairpin-like turn involving L32-R36 in ANK repeat #1 exhibits slow conformational averaging on the NMR time scale and appears dynamically different from the corresponding region (D65-169) of ANK repeat #2.

Amino Acid Sequence↗
PubMed1997

Levels and determinants of gynecological morbidity in a district of south India.

This article presents the results of an assessment of gynecological morbidity among 385 women with young children residing in a district of Karnataka State, South India. All three main modes of assessment (clinical examination, laboratory tests, and self-reports) reveal a high burden of reproductive tract infections. The two most common conditions, identified by laboratory tests, were bacterial vaginosis and mucopurulent cervicitis. Approximately one-fourth of the women had clinical evidence of pelvic inflammatory disease, cervical ectopy, and fistula. The contribution of sexually transmitted diseases to overall gynecological morbidity appears to be relatively modest; 10 percent were so diagnosed. Associated conditions of anemia and chronic energy deficiency were common. Severe anemia was found in 17 percent of cases and severe chronic energy deficiency in 12 percent. These results indicate that radical improvements in women's health in India will require far more than the diagnosis and treatment of reproductive tract infections.

Comorbidity↗
PubMed1996

Alpha helix-RNA major groove recognition in an HIV-1 rev peptide-RRE RNA complex.

The solution structure of a human immunodeficiency virus type-1 (HIV-1) Rev peptide bound to stem-loop IIB of the Rev response element (RRE) RNA was solved by nuclear magnetic resonance spectroscopy. The Rev peptide has an alpha-helical conformation and binds in the major groove of the RNA near a purine-rich internal loop. Several arginine side chains make base-specific contacts, and an asparagine residue contacts a G.A base pair. The phosphate backbone adjacent to a G.G base pair adopts an unusual structure that allows the peptide to access a widened major groove. The structure formed by the two purine-purine base pairs of the RRE creates a distinctive binding pocket that the peptide can use for specific recognition.

Amino Acid Sequence↗
PubMed1996

Tumor necrosis factor-alpha (TNF-alpha)-induced optic neuropathy in rabbits.

Both in vitro and in vivo studies have implicated a role for tumor necrosis factor-alpha (TNF alpha) in various demyelinating diseases, including HIV-related encephalopathy. To investigate whether intravitreal TNF alpha can induce optic nerve axonal damage in a rabbit eye model, fifteen rabbit eyes were initially injected with TNF alpha (final concentrations: 2U, 20U, and 200U respectively) and studied at varying time intervals for up to 24 weeks post-injection, using light and electron microscopy. Control optic nerves (no injection or diluent injection only) had normal myelinated axons and glia; the myelinated regions, neural retina, retinal glia and vasculature of control retinas were normal. In TNF alpha-exposed optic nerves, intact, degenerating and demyelinated axons were interspersed. Astrogliosis was present, particularly from 8 weeks p.i. and was noted up to 24 weeks. Oligodendrocytes were not severely affected in TNF alpha-exposed optic nerves, and activated macrophages or microglia were not obvious. Axonal degeneration was visible among the more superficial myelinated fibers in TNF alpha-exposed retinas however the neural retina glia were unaffected. These observations suggest that the axonal degeneration induced in TNF alpha-exposed rabbit optic nerves over a 24 week period was most likely related to direct effects of TNF alpha on optic nerve axons, and not primarily due to anterograde degeneration from retinal lesions. In-so-far as neurological pathology in general, and optic nerve degeneration in particular, has been described in AIDS, and TNF alpha levels may be elevated in this disease, it is of great clinical significance that TNF alpha has the capacity to mediate neuronal or axonal injury. If so, strategies to block or inhibit TNF alpha can be pursued for treatment for the neurological symptoms of AIDS.

Animals↗
PubMed1996

Preliminary morphometric study of tumor necrosis factor-alpha (TNF alpha)-induced rabbit optic neuropathy.

Intravitreal injections of tumor necrosis factor-alpha (TNF alpha) induce morphological changes in the optic nerve suggesting a primary TNF alpha-induced optic neuropathy. A preliminary morphometric analysis of axonal loss and degeneration in optic nerves of a TNF alpha rabbit eye model was conducted. Fifteen rabbits were injected in one eye only with TNF alpha (final doses: 2 U, 20 U and 200 U respectively), and optic nerve cross-sections were examined using a semi-automated image analysis system, at varying time intervals for up to 24 weeks post-injection. Control optic nerves (uninjected or injected with diluent only) were also assessed. Intact, degenerating and demyelinated axons were visible in TNF alpha-exposed optic nerves. Considerable variation was observed between TNF alpha-exposed optic nerves, however the intact axon density consistently decreased in the 200 U TNF alpha group, although not in the 2 U and 20 U groups. Overall, TNF alpha-exposed optic nerves had significantly more degenerating profiles compared to control optic nerves. These observations suggest a dose-dependent axonal loss and degeneration associated with the morphological changes induced in rabbit optic nerves following intravitreal injection of TNF alpha.

Animals↗
PubMed1996

Medical students' attitudes toward electroconvulsive therapy: an Indian perspective.

A questionnaire addressing issues related to electroconvulsive therapy (ECT) was administered to 165 undergraduate medical students in an urban hospital in India. Of various sources, the mass media contributed most to the students' knowledge about and attitudes toward the treatment. Senior and junior students differed little in their knowledge and attitudes. Many students believed that ECT is cruel and barbaric and that it occasions pain to the patient; however, few considered that it compromises thinking and reasoning, that it causes brain damage, that it is misused, that it is used to punish violent or uncooperative patients, that it is outmoded, or that it should be banned. Many students thought that the use of ECT should be governed by law. Myths and concerns about ECT were identified in a subset of students who expressed reluctance to receive ECT if indicated for themselves. There is a need to improve undergraduate medical education on ECT.

Adult↗
PubMed1995

Detoxification of a local Microcystis bloom by an algicidal antibiotic from Oscillatoria late-virens.

Mouse toxicity due to microcystin (hepatotoxin) was detected in water bloom of a local lake, comprising mainly Microcystis aeruginosa. Both toxicity and biomass content of the phytoplankton varied seasonally. Incubations with an algicidal metabolite from Oscillatoria late-virens and a herbicide 3-(3,4-dichlorophenyl)-1, 1-dimethyl urea (DCMU) caused depigmentation and detoxification in bloom samples. Algicide-incubation also encouraged growth of protozoa and bacteria, pathogenic form included.

Anti-Bacterial Agents↗
PubMed1995

Designing of peptides with immuno-modulatory properties using protein A as a probe.

A series of reports from our laboratory have described the multifarious properties of protein A of Staphylococcus aureus Cowan I, apart from its IgG binding affinity. Original reports regarding its anti-tumor, anti-toxic, anti-carcinogenic and immunomodulatory properties published earlier by the authors have implicated some uniqueness of this bacterial protein. It was conceived that such diversified properties must lie in its specific peptide sequences, rendering it to act and behave as a multipotent "Biological Response Modifier" (BRM). The high resolution X-ray structure of protein A-Fc complex has been delineated earlier, and has been the foundation of many protein engineering studies. This structure along with the amino acid sequence data of its four repetitive domains provided us the basis for designing an octapeptide. This octapeptide was synthesized by solid phase peptide synthesis considering it as the probable site through which PA binds IgG. This octapeptide (NH2-Gln-Asn-Ala-Phe-Tyr-Glu-Ile-Leu-COOH) is present in the first helical segment of B-domain of protein A, and also is a part of domain D, A and C. This octapeptide has been shown to bind IgG by the immunoblotting technique. The binding affinity of the octapeptide appears to be significantly higher than that of intact protein A, as was revealed by calculation of Ka (association constant) and Kd (dissociation constant) values. This octapeptide might serve as a good immunoadsorbant for IgG and/or immune complexes.

Adjuvants, Immunologic↗
PubMed1994

Optic nerve morphometry following axonal degeneration from SAIDS in rhesus monkeys.

In order to further study AIDS (acquired immunodeficiency syndrome) related neuropathologic findings, specifically progressive diffuse leuko-encephalopathy (PDL) and optic neuropathy, ten macaque monkeys (Macaca mulatta) were infected with simian immunodeficiency virus (SIV), observed for varying periods, and then sacrificed and tissue prepared for analysis. A marked difference from human AIDS pathology was found: in all monkeys, there was significant peripheral axonal dropout, as opposed to relatively little dropout in the central areas of the nerves (t stat. = -5.9, p < .001). In those monkeys infected with SIV for over one year, the axonal loss in the periphery was also greater than in the central optic nerve (t stat. = -5.03, p < .001); monkeys infected with SIV for less than one year had slightly less peripheral than central loss (t stat. = -4.5, p = .001). When compared with humans, however, it was found that the overall loss of axons was less (15% in monkeys vs. up to 45% in humans). There was also a lack of discernible retinal pathology, such as cotton wool spots, in the monkey tissue.

Animals↗
PubMed1994

Relationship between rate of administration of electroconvulsive shocks and rate of learning in rats: implications for the practice of ECT.

Number of electroconvulsive therapy (ECT) treatments administered and severity of psychopathology confound the interpretation of clinical studies that address the relationship between the rate of administration of ECT and cognitive morbidity occasioned by the treatment. A preclinical study was therefore conducted to address the issue. Three groups (n = 8/group) of adult male Sprague-Dawley rats received six electroconvulsive shocks (ECS) in daily ECS, 3 ECS/week, and 2 ECS/week schedules; a fourth group (control; n = 8) received only sham ECS. From days 2 to 7 after the conclusion of the ECS/sham ECS course, the rats were monitored for learning on the Hebb-Williams complex maze. The control, 2 ECS/week, and 3 ECS/week groups showed significant learning by days 3, 5, and 7, respectively, while the daily ECS group showed no significant learning during the assessment period. This indicates that even when the cumulative effect of ECS on learning is controlled for, more frequent ECS is associated with slower learning. Extrapolating to clinical settings, it is suggested that wider spacing of ECT may lessen ECT-induced cognitive morbidity.

Animals↗
PubMed1991

Benign intracranial hypertension--its unusual manifestations.

Among our patients with benign intracranial hypertension, we encountered 3 who presented with unusual clinical features. Presentations were pseudotumor without papilledema, unilateral papilledema, and IIIrd and Vth cranial nerve involvement. Lumbo-peritoneal shunt completely resolved the symptoms and signs in 2 of the patients; in the third, symptoms and signs cleared following lumbar puncture.

Adult↗
PubMed1990

Studies on the synthesis, characterisation and antimicrobial activity of new Co(II), Ni(II) and Zn(II) complexes of Schiff base derived from ninhydrin and glycine.

For the first time, Co(II), Ni(II) and Zn(II) complexes have been synthesized involving an intermediate Schiff base, indane-1,3-dione-2-imine-N-acetic acid the condensed product of ninhydrin and glycine. These coloured complexes were characterised by elemental analysis, molar conductivity, thermogravimetric analyses/differential thermal analysis, infrared, magnetic susceptibility, NMR and electronic spectral studies. Mechanisms for their formation have been proposed. The experimental studies reveal that the complexes possess octahedral stereochemistry whereas the Schiff base behaves as a monobasic tridentate ligand. A molecular structure for the metal complexes is also proposed. A comparative study of the antimicrobial activity of ninhydrin and the corresponding metal complexes against Escherichia coli, Proteus mirabilis, Staphylococcus aureus and Streptococcus faecalis has been undertaken and the results are discussed.

Anti-Bacterial Agents↗
PubMed1990

Bacteriochlorophyll and Photosynthetic Reaction Centers in Rhizobium Strain BTAi 1.

Rhizobium strain BTAi 1, which nodulates both stems and roots of Aeschynomene indica L., formed bacteriochlorophyll and photosynthetic reaction centers resembling those of purple photosynthetic bacteria when grown aerobically ex planta under a light-dark cycle. Bacteriochlorophyll formation was not observed under continuous dark or light growth conditions. The amount of pigment formed was similar to that previously found in aerobic photosynthetic bacteria. Stem nodules appear to fix nitrogen photosynthetically, as illumination of A. indica stem nodules with near-infrared light resulted in an enhanced rate of acetylene reduction. Near-infrared light did not enhance acetylene reduction when either A. indica or soybean root nodules were illuminated. The BTAi 1 isolate can be differentiated from members of the family Rhodospirillaceae by several criteria.

Journal Article↗