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Biomedical subjects

S Sahai

Publications and source records attributed to S Sahai.

At least 19 recordsLinked to original sources
PubMed2001

Childhood bacterial meningitis in Pondicherry, South India.

OBJECTIVE: To identify causative bacteria from cerebrospinal fluid (CSF) of children with meningitis and analyse various clinical and laboratory parameters. METHODS: Over a 20 month period, September 1994 to April 1996, one hundred episodes of acute bacterial meningitis in children aged 1 month-12 years were studied in a tertiary urban hospital in South India. Organisms were isolated from the cerebrospinal fluid (CSF) in 35% of cases. Among infants and children, the two major pathogens were H. influenzae (17%) and S. pneumoniae (12%). RESULTS: The illness at presentation was mild in 13% and severe in 36% of cases. The association of subdural effusion in children with Salmonella Gp B meningitis merits attention. The overall case fatality rate was 25%. S. pneumoniae had a higher case fatality rate than Salmonella Gp B and H. influenzae (50% vs 17% vs 12%). All the three infants below 3 months of age with S. pneumoniae meningitis died. On analysis of selected clinical and laboratory features by discriminant analysis, CSF culture was the significant (P = 0.02) variable in relation to outcome. In pneumococcal meningitis, CSF WBC count was a highly significant variable in relation to outcome (Wilk's Lambda 0.15, F = 24.64, P = 0.0002). CONCLUSION: Prevention of infections due to H. influenzae and S. pneumoniae should be given higher priority.

Analysis of Variance↗
PubMed2000

Comparison of PathVysion and INFORM fluorescence in situ hybridization kits for assessment of HER-2/neu status in breast carcinoma.

BACKGROUND: Fluorescence in situ hybridization is advocated for precise assessment of HER-2/neu status in breast carcinoma; however, few objective data compare available kits for clinical laboratories contemplating development of the test. METHODS AND RESULTS: Thirty breast carcinomas were analyzed for HER-2/neu amplification with the PathVysion kit (Vysis, Downers Grove, IL) and INFORM kit (Ventana Medical Systems, Tucson, AZ). Each kit was evaluated for morphology, background staining, technical and interpretation time, and cost. PathVysion detected amplification in seven of 30 cases (23.3%); INFORM detected six of 30 cases (20%). A greater percentage of PathVysion cases showed good morphology and lower background staining than INFORM. Technical and interpretation times, as well as cost, were less with PathVysion than INFORM. CONCLUSION: PathVysion is superior to INFORM because it produces better morphology and less background staining and is faster and less expensive than the INFORM kit. It also includes a chromosome 17 probe that serves as an internal control and enables correction for chromosome 17 aneuploidy.

Breast Neoplasms↗
PubMed2000

HER-2/neu assessment in breast cancer by immunohistochemistry and fluorescence in situ hybridization: comparison of results and correlation with survival.

BACKGROUND: HER-2/neu immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) results guide breast cancer therapy; however, few studies compared the results and no published studies have correlated them with patient outcome. METHODS AND RESULTS: We compared results, cost, and turnaround time in 117 archival, invasive breast carcinomas and compared 50-month survival in 65 of these cases using commercial HER-2/neu IHC and FISH assays. Twenty-one of 112 FISH (19%) and 33 of 117 IHC cases (28%) were positive. Concordance was high overall (88%; 98 of 112 cases) and in IHC 3+ cases (88%; 14 of 16 cases) but low in IHC 2+ cases (35%; six of 17 cases). Survival correlated with IHC results in 3+ cases (P =.02) and FISH cases with signal ratio greater than 4.0 (P =.03), but not in IHC 2+ cases (P=.7). Cost and turnaround time were greater for FISH. CONCLUSION: IHC is appropriate for initial HER-2/neu assessment; however, patients with tumors scored less than 3+, particularly those interpreted as 2+, would benefit from FISH to more accurately assess HER-2/neu status and avoid inaccurate prognostication and inappropriate treatment.

Breast Neoplasms↗
PubMed2000

Sinusitis and carotid artery stroke.

The relationship between sinusitis and ischemic stroke is unexplored. The anatomic proximity between the paranasal sinuses and the internal carotid artery suggests that inflammation of the sinuses could easily extend to the intracranial vasculature. We report 4 patients with acute ischemic stroke and extensive disease of the paranasal sinuses. All patients had large vessel stroke involving the internal carotid artery territory. All patients had extensive disease of the sphenoid and other sinuses. The sinus disease was demonstrated by magnetic resonance imaging. These case report observations suggest a relationship between inflammation of the paranasal sinuses, particularly sphenoid sinusitis, and ischemic stroke.

Carotid Artery, Internal↗
PubMed2000

Predictive value of maximal stress test in patients showing atypical or no symptoms of ischaemic heart disease.

A study was carried out on 76 patients attending outpatients' department of medicine, Government Medical College, Nagpur. These patients had either (a) atypical angina or (b) no symptoms but certain factors for ischaemic heart disease. All cases were subjected to maximal stress test. Thirty-five cases (46.05%) showed a positive result on the basis of 'ST' segment depression of 2 mm or more. In the absence of facilities for coronary angiography, treadmill test is an important diagnostic tool for ischaemic heart disease.

Adult↗
PubMed1995

Spectrum of renal cortical necrosis in acute renal failure in eastern India.

Renal cortical necrosis is an uncommon cause of acute renal failure. We report 23 cases of biopsy-proven renal cortical necrosis which constituted 6.3% (23/363) of all cases of acute renal failure studied over a period of seven years (1985-92). The patients were divided into two groups: obstetric and non-obstetric. Obstetric complications were responsible for renal cortical necrosis in 15 (65.2%) patients while non-obstetric conditions accounted for the remaining eight (34.8%) cases. The overall incidence of cortical necrosis in obstetric acute renal failure was 15/63 (23.8%) patients, the incidence being nearly equal in early (20.5%) and late (29%) pregnancy. Post-abortum renal failure was the sole cause of cortical necrosis in early pregnancy in the obstetric group. Haemolytic uraemic syndrome (three patients) and septicaemia (two patients) were the main cause of necrosis in the non-obstetric group. The cortical necrosis was diffuse and patchy in 17 and six patients, respectively. The disease had a fatal prognosis in 20 (87%) patients; mortality was due to uraemic complications and infections in the majority of patients. The high frequency of post-abortum renal cortical necrosis in our patients is similar to the experience of other Indian workers.

Abortion, Spontaneous↗
PubMed1990

Glutamate in the mammalian CNS.

The excitatory amino acid glutamate plays an important role in the mammalian CNS. Studies conducted from 1940 to 1950 suggested that oral administration of glutamate could have a beneficial effect on normal and retardate intelligence. The neurotoxic nature of glutamate resulting in excitotoxic lesions (neuronal death) is thought possibly to underlie several neurological diseases including Huntington's disease, status epilepticus. Alzheimer's dementia and olivopontocerebellar atrophy. This neurodegenerative effect of glutamate also appears to regulate the formation, modulation and degeneration of brain cytoarchitecture during normal development and adult plasticity, by altering neuronal outgrowth and synaptogenesis. In addition to its function as a neurotransmitter in several regions of the CNS, glutamate seems to be specifically implicated in the memory process. Long-term potentiation (LTP) and long-term depression (LTD), two forms of synaptic plasticity associated with learning and memory, both involve glutamate receptors. Studies with antagonists of glutamate receptors reveal a highly selective dependency of LTP and LTD on the N-methyl-D-aspartate and quisqualate receptors respectively. The therapeutic value of glutamate receptor antagonists is being actively investigated. The most promising results have been obtained in epilepsy and to some extent in ischaemia and stroke. The major drawback remains the inability of antagonists to permeate the blood-brain barrier when administered systemically. Efforts should be directed towards finding antagonists that are lipid soluble and able to cross the blood-brain barrier and to find precursors that would yield the antagonist intracerebrally.

Animals↗
PubMed1990

Changes in gill structure induced by BHC, lindane and endosulfan in the fresh-water teleost Puntius ticto (Ham.).

The effect of three organochlorinated pesticides on the gill structure of Puntius ticto, a freshwater teleost, was investigated. Fish exposed to sublethal concentrations of BHC (0.17 ppm), lindane (0.19 ppm) and endosulfan (0.20 ppm) were studied. The pesticides were detected qualitatively in the gill tissue by thin-layer chromatography (TLC). The results showed that they could be detected after 15 days' exposure, but not after 96 h exposure. Histopathological examination revealed several structural and functional changes in the gills. Exposure to BHC was followed by an inflammatory reaction and complete dystrophy of the lamellar structure of the gills. Lindane-treated fish showed disruption of the epithelial covering of the gills and excessive haemorrhage in the blood vessels. In exposure to endosulfan the gill lamellae shrank and became thinner.

Animals↗
PubMed1989

The yolk nucleus in the freshwater teleost Garra gotyla gotyla (Gray).

The structure and functional significance of the yolk nucleus in Garra are described. The study shows that the yolk nucleus appears in the cytoplasm of the early perinucleolus stage of the oocyte. It is present as a deeply stained structure enclosed in a vesicle. It disappears in the yolk vesicle stage and vitellogenesis begins soon afterwards. This probably indicates that it plays a role in the initiation of vitellogenesis. When yolk formation starts, the yolk nucleus disappears; this also suggests that it is of functional significance in yolk synthesis.

Animals↗
PubMed1987

Genesis and systematization of cardiovascular anomalies and analysis of skeletal malformations in murine trisomy 16 and 19. Two animal models for human trisomies.

On account of genetic homologies, trisomy 16 in the mouse is generally regarded as a direct animal model of Down's syndrome. Mouse trisomy 19, on the other hand, can be seen as a general model of human trisomies. A detailed evaluation of the cardiovascular system and skeleton in 109 fetuses with trisomy 16 and 422 balanced siblings was carried out in order to systematize the cardiovascular anomalies and the pathogenetic mechanisms responsible for their formation according to (1) general retardation, (2) genetically determined impairment of neural-crest cell migration, and (3) direct gene action on organogenesis. Skeletal malformations in the form of a rib-vertebra syndrome encountered in Ts 16 are described here for the first time. In 108 fetuses and 219 neonates resulting from cross-breeding to induce trisomy 19, we found no significant increase in the frequency of the foregoing anomalies. These results are discussed with regard to a chromosome-specific genetic influence as opposed to a general effect of chromosome imbalance. The specificity of the Ts16 syndrome is compared with that of individual organ anomalies as can be induced by teratogenic agents. Our investigation shows that specific malformation patterns of a particular type can be produced by a variety of methods. However, the overall patterns of the two syndromes are highly chromosome-specific. On detailed examination, the malformation pattern of mouse trisomy 16 shows significant similarities with that of human trisomy 21.

Animals↗
PubMed1985

2-Amino-4-phosphonobutyric acid selectively blocks two-way avoidance learning in the mouse.

There seems to be ample evidence supporting the view that glutamate plays a significant role in the mammalian brain as a neurotransmitter. It is considered to be a likely transmitter candidate in one or more hippocampal pathways. Recently it has been visualized in excitatory, possibly glutamatergic, neurons in the hippocampus. Glutamate has been proposed to mediate memory formation. We wanted to see if blocking glutamate action by a specific glutamate antagonist could result in reduction of learning ability. 2-Amino-4-phosphonobutyric acid (APB) is an analogue of glutamic acid and has been used as a glutamate antagonist in electrophysiological studies on invertebrate neuromuscular junction, retina and hippocampus. We tested the influence of APB on the acquisition of two way avoidance learning in the shuttle box and on learning in the water maze. Our results show that intraperitoneal injection of APB led to a reduction in avoidance learning, whereas learning in the water maze was unaffected.

Aminobutyrates↗