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Biomedical subjects

S Misra

Publications and source records attributed to S Misra.

At least 145 records · Page 8Linked to original sources

Isozymic pattern of lactate dehydrogenase in cases of bancroftian filariasis.

Isozymic patterns of lactate dehydrogenase (E.C. 1.1.1.27) by polyacrylamide gel electrophoresis (PAGE) were observed in various categories of filariasis and controls, i.e. asymptomatic microfilaraemia and symptomatic amicrofilaraemia, endemic normal and non-endemic normal. Lactate dehydrogenase (LDH) activity was also observed amongst the above categories of patients. An increase in enzyme activity and change in the isozymic pattern was observed in the above categories of filaria infected serum. LDH activity doubled in asymptomatic microfilaraemia whereas in symptomatic amicrofilaraemia the increase in LDH activity was thirtyfold. The isozymic pattern of microfilaraemic cases showed the presence of three bands B4, A1B3, A2B2, which are quite thick as compared to normal healthy subjects, whereas the patients with symptomatic amicrofilaraemia showed marked elevation of serum LDH-4 or A3B1. The LDH was partially purified by combined treatment of (NH4)2SO4 fractionation and gel filtration. The isozymic pattern of purified LDH showed a similar pattern.

Animals↗

A comparative study of acetylcholinesterase activity in bovine (S. cervi) and human (B. malayi, W. bancrofti) filaria.

Setaria cervi, a bovine filarial parasite, contains a significant amount of acetylcholinesterase (AChE) activity with microfilaria having five to ten times more AChE activity than female and male adult worms, respectively. Because AChE shows substrate specificity and hydrolyzes acetylthiocholine but not butrylthiocholine, this parasitic enzyme is likely a true acetylcholinesterase. The latter also resembles an AChE enzyme in the human filarial parasite B. malayi which hydrolyzes acetylthiocholine iodide three times faster than butrylthiocholine iodide. The S. cervi AChE, like its counterpart, also exhibit inhibition with eserine, a specific inhibitor of this enzyme. Subcellular localization of AChE in adult female worms shows enzyme activity both in the mitochondrial and post-mitochondrial fraction. However, enzyme activity in the soluble fraction is twenty-seven times greater than in the mitochondrial fraction.

Acetylcholinesterase↗

In vitro and in vivo effect of diethylcarbamazine on the activity of acetylcholinesterase from Wuchereria bancrofti infected human serum.

The acetylcholinesterase (AChE) activity was measured in human serum from persons infected with the filarial parasite Wuchereria bancrofti. The asymptomatic microfilaremic serum showed five times increase in AChE-activity as compared with normal serum, whereas only little difference was observed in serum from patients with elephantiasis. Similar results were obtained when the enzyme activity was measured in the immune complexes precipitated with polyethyleneglycol. Further, the effect of the antifilarial drug diethylcarbamazine (DEC), on the AChE activity of infected and normal serum was studied in in vivo and in vitro experiments. In vitro, DEC was found to be effective only with respect to AChE from asymptomatic microfilaremic serum where 75% decrease in enzyme activity was observed at 100 mumol. The oral administration of DEC (5 mg/kg of body weight/day) effected the activity of AChE from microfilaremic serum as shown after 1 hr, 1 and 3 weeks. A regular decrease in enzyme activity of asymptomatic microfilaremic serum was observed. By increasing time periods and after three weeks the level of AChE reaches the normal value. In vitro and in vivo the same concentration of DEC has negligible effect on the normal serum suggesting that in case of asymptomatic microfilaremic serum the increased activity of AChE is different in nature than the host acetylcho-[abstract incomplete in journal]

Acetylcholinesterase↗

The normal glenohumeral relationships. An anatomical study of one hundred and forty shoulders.

We measured the dimensions of the humeral and glenoid articular surfaces in 140 shoulders that were representative of a given population of patients, and also evaluated several glenohumeral relationships. Ninety-six measurements were made in the shoulders of cadavera and forty-four, on magnetic resonance-imaging studies of living patients. Eighty-five per cent of the humeral measurements fell within eight fixed combinations of the radius of curvature and the thickness of the humeral head, in two-millimeter increments. The average radius of curvature of the humeral head in the coronal plane was 24 +/- 2.1 millimeters (range, nineteen to twenty-eight millimeters). The average thickness of the humeral head was 19 +/- 2.4 millimeters (range, fifteen to twenty-four millimeters). There was a wide variability in the size of the humeral head and a direct correlation between the differences in size and the heights in both men and women. The humeral articular surface was spherical in the center; however, the peripheral radius was two millimeters less in the axial plane than in the coronal plane. Thus, the peripheral contour of the articular surface was elliptical (ratio, 0.92). The radius of curvature of the glenoid, measured in the coronal plane, was an average of 2.3 +/- 0.2 millimeters greater than that of the humeral head. The average dimensions of the glenoid in the superior-inferior and anterior-posterior (lower half) directions were 39 +/- 3.5 millimeters (range, thirty to forty-eight millimeters) and 29 +/- 3.2 millimeters (range, twenty-one to thirty-five millimeters). The anterior-posterior dimension of the glenoid was pear-shaped, the lower half being larger than the top half. The ratio of the lower half to the top half was 1:0.80 +/- 0.01. There was a strong linear correlation between the lateral humeral offset and the size of the humeral head (radius of curvature and thickness). The average lateral humeral offset was 56 +/- 5.7 millimeters (range, forty-three to sixty-seven millimeters). The superior most point on the humeral articular surface was an average of 8 +/- 3.2 millimeters (range, three to twenty millimeters) cephalad to the top of the greater tuberosity. Our data show that reconstruction of the lateral humeral offset is important in optimization of the moment arm of the deltoid and rotator cuff and of the normal tension of the soft tissue after prosthetic reconstruction.

Adult↗

Role of Ca2+ ion on Leishmania-macrophage attachment.

Leishmania donovani, the etiological agent for the disease visceral leishmaniasis, attach themselves to the macrophages for initiation of the disease. The attachment process has been found to be regulated by Ca2+ ions. Verapamil, a Ca(2+)-channel blocker inhibits Leishmania-macrophage attachment. The inhibitory effect is increased with time. Nifedipine, another Ca(2+)-channel blocker exhibits the same effect. The attachment process is stimulated by Ca(2+)-ionophore alone. The inhibitory effects of the calcium channel blockers are reversed by the ionophore.

Animals↗

Lipid changes of goat sperm plasma membrane during epididymal maturation.

Highly purified plasma membranes of maturing goat caput-, corpus- and cauda-epididymal spermatozoa were isolated by aqueous two-phase polymer methods and their lipid constituents were analysed. Phospholipid (approx. 75% w/w), neutral lipid (approx. 15% w/w) and glycolipid (approx. 10% w/w) were the major sperm membrane lipids. There was a significant decrease in the total lipids (approx. 25% w/w), phospholipid (approx. 30% w/w) and glycolipid (approx. 80% w/w) contents of sperm membrane during epididymal maturation. On the contrary, the mature cauda-sperm membrane showed greater (approx. 50% w/w) neutral lipid content than that of the immature caput sperm. Phosphatidylcholine (PC), phosphatidylethanolamine (PE) and sphingomyelin were the phospholipids of the sperm membrane, the former two being the major lipids. Both PC and PE fractions consisted of three species--diacyl, alkylacyl and alkenylacyl forms, the last one being the dominant species in both PC and PE. Of all the phospholipids, diacyl PE decreased most strikingly (approx. 65% w/w) during sperm maturation. The neutral lipid fraction contained sterols, wax esters, 1-O-alkyl-2,3-diacylglycerol, triacylglycerol and fatty acids. Sterols represented nearly 75% w/w of the neutral lipids and cholesterol was the major component (approx. 95% w/w) of the sterol fraction. The sperm maturity was associated with marked increase of sterol (approx. 60% w/w) and steryl ester (approx. 200% w/w) and decrease (approx. 50-65% w/w) of the other membrane-bound neutral lipids. The glycolipid was identified as monogalactosyldiacylglycerol. The fatty acid profile of the various membrane lipids underwent marked alteration during the epididymal transit of the male gametes. Cholesterol/phospholipid and saturated/unsaturated fatty acid ratios increased greatly in the maturing sperm membrane. The altered lipid profile of the mature sperm membrane leads to changes in its fluidity that play an important role in determining the structure and functions of the biomembrane.

Animals↗

Clinical & bacteriological profile of neonatal pneumonia.

In a prospective study of 44 neonates (33 outborn and 11 inborn) with pneumonia, the bacteriology of pneumonia was determined by blood culture and serum counterimmunoelectrophoresis (CIEP). Twenty-nine babies also underwent lung aspiration. The lung aspirate was subjected to bacterial culture and CIEP. CIEP was done to detect the bacterial antigens of Streptococcus pneumoniae and Haemophilus influenzae. Absence of tachypnoea, found more commonly in low birth weight babies, was a poor prognostic sign. Low birth weight babies had a significantly higher mortality than babies with normal birth weight. Altogether, a bacterial etiology of neonatal pneumonia could be established in 25 cases (56.7%). In 10 babies, Strep. pneumoniae antigen was detected in serum and/or lung aspirate. Micro-organisms were cultured from blood and/or lung aspirate from 17 babies. Eleven babies (25%) grew Gram negative bacteria. The common bacteria identified in decreasing order of frequency were Strep. pneumoniae, Klebsiella pneumoniae, Staphylococcus epidermidis, Acinatobacter lowfii, Staph. aureus, Pseudoamonas aeruginosa etc. All the Gram negative bacteria as well as staphylococci were sensitive to amikacin while only 23.5 per cent was sensitive to gentamicin. All staphylococci isolated were sensitive to methicillin.

Bacteremia↗

Splenoportovenography: safety, success rate and hemodynamic changes, and incidence and natural history of splenic hematoma.

Forty-five non-cirrhotic patients undergoing splenoportovenography (SPV) were studied. SPV was performed successfully in 43 (95.5%) patients. Local pain was encountered in 12 (26.6%) and lasted for a mean (+/- SD) of 7 +/- 3.8 hours. Local tenderness was noted in 17 (37.7%) and lasted for 6.8 +/- 3.7 hours. The mean rise in the pulse rate after the procedure was 6.5 +/- 4.7 beats per minute and the fall in the systolic and diastolic blood pressures was 3.4 +/- 2.5 and 0.8 +/- 1.7 mmHg respectively. Post-SPV splenic hematoma was noted in 3 (6.6%) patients. All were subcapsular, at the site of puncture, and disappeared by the seventh day. There was no difference in the age, change in the pulse rate, and fall in systolic or diastolic blood pressures between those who developed and those who did not develop hematoma. One patient required one unit of blood transfusion. There were no deaths. SPV was noted to be a simple and safe procedure with a high success rate with minimal morbidity and no mortality.

Adolescent↗

Cytotype control of Drosophila P element transposition: the 66 kd protein is a repressor of transposase activity.

Drosophila P transposable elements encode two proteins, an 87 kd transposase protein and a 66 kd protein that has been hypothesized to repress transposition. We have made germline transformants carrying modified P element derivatives that encode only the 66 kd protein and shown that these elements repress transposase activity in both the germline and the soma. The position of these elements in the genome quantitatively affected their ability to negatively regulate transposase and to express the 66 kd protein. Single 66 kd element-containing strains did not exhibit the maternal inheritance of P cytotype characteristic of P strains. However, we demonstrated that a true P strain produced higher levels of the 66 kd protein during oogenesis than single 66 kd P elements. Thus, the expression of the 66 kd repressor during oogenesis may be a major determinant of the maternal effect of P cytotype.

Animals↗

The hospital trauma team: a model for trauma management.

A triage system was established as the initiating mechanism for a trauma team response to assist the assessment and early management of patients presenting to an accident and emergency department. A checklist of triage criteria was used. During a 6-month period, 342 patients (29.7% of trauma admissions) satisfied the triage criteria, which should have resulted in an average of 1.9 trauma team calls per day. Staff compliance with the triage tool was 75.4%. The overtriage rate for the checklist criteria was 52.7%. The triage tool identified patients with severe injuries who were not initially considered sufficiently injured to justify initiation of the trauma team response. The sensitivity of the triage tool in identifying patients with serious injury was 95.0%. Comparison of the review with a similar review performed 12 months earlier demonstrated that staff compliance with initiating the trauma team response had improved. Using data from 564 patients from both series, logistic regression analysis of the power of the triage criteria to predict serious injury contributed to a revision of the triage criteria. This trauma triage tool and trauma team response constitute a valid approach to the early hospital management of trauma patients. This system may be more appropriate or achievable in many hospitals than the construction of dedicated trauma reception units or permanent surgical staffing of general Accident and Emergency departments.

Adolescent↗

A new technique of in vitro assay of antifilarials using different life-forms of Acanthocheilonema viteae.

An approach has been made to develop an in vitro screening system to evaluate antifilarial efficacy of compounds and an effort has been made to establish correlation between in vivo and in vitro screening technique. The in vitro experiments were conducted simultaneously using three life-forms (adult, microfilaria and infective larva) of Acanthocheilonema viteae using five antifilarial agents representing four chemical groups. All the selected antifilarials were known to be active against one or more life-stages of human lymphatic or animal filariids. Diethylcarbamazine and Centperazine showed 100% microfilaricidal and infective larvicidal actions at concentrations of 0.5 and 0.25 mg/ml and 0.5 and 0.0313 mg/ml respectively with no effect on adult worms even at 1 mg/ml. Levamisole was effective against all the three life-stages killing 100% adult worms at 1 mg/ml, infective larvae at 0.0625 mg/ml and microfilariae at 0.0125 mg/ml, while mebendazole exhibited activity only against adult worms (100% at 0.5 mg/ml). Ivermectin killed adult females and microfilariae at 0.063 and 0.5 mg/ml respectively but did not affect infective larvae even up to 1 mg/ml concentration. The study indicated that in vitro screening system can be used for primary screening of potential antifilarial agents provided three life-forms of A. viteae are used simultaneously to avoid false negative results. It would however be more appropriate if a few compounds of a particular chemical class are initially assessed both in vivo and in vitro for validity of subsequent test results in vitro.

Animals↗

Training perception of acute airflow obstruction.

Ten asthmatics selected for their tendency to experience frequent acute exacerbations were instructed in peak flow measurement. Each subject then recorded estimated peak flow (EPF) and measured peak flow (PF) at home twice daily. Data for up to 56 consecutive observations (4 weeks) per subject were analyzed. The correlation coefficient between EPF and PF following PF drops of 15% was .993 overall and was not significantly different following PF drops even greater than 25%. The absolute and proportional differences between PF and EPF were also not significantly affected by the magnitude of PF drop but decreased over time indicating improved accuracy of estimates with practice. Asthmatics can be trained to estimate accurately acute drops in airflow. Such ability has not been demonstrated in prior studies which utilized verbal symptom reports as indicators of subjective perception of airflow. Accurate perception would be a useful aid in achieving early recognition of acute exacerbations and in improving medication compliance. It is an adjunct to regular peak flow measurement, not a substitute for it.

Airway Obstruction↗

Analysis of stress-induced gene expression in fish cell lines exposed to heavy meals and heat shock.

We have examined the effect of heavy metals on the expression of two major groups of stress-induced proteins in fish cell lines: the 70 kDa heat-shock proteins (hsp70) and metallothioneins (MTs). The rainbow trout hepatoma (RTH) cell line synthesized the hsp70 protein in response to zinc and heat shock, while chinook salmon embryonic (CHSE) cells synthesized this protein in response to these inducers, as well as cadmium. The synthesis of this 70 kDa protein was correlated with the accumulation of hsp70 mRNA as measured by hybridization to a trout hsp70 gene probe. Heavy metals also induced the synthesis of MT in RTH cells. However, heat shock did not result in induction of MT and its mRNA. Unlike RTH cells, CHSE cells did not synthesize MT following exposure to cadmium or zinc. When these cells were treated with 5-azacytidine prior to heavy metal treatment, accumulation of MT mRNA was observed. Northern blot analysis of total RNA from 5-azacytidine treated CHSE cells, using a trout MT (tMT-B) cDNA probe, indicated that the time-course of induction and the maximal level of MT mRNA accumulation in response to cadmium and zinc paralleled that observed in RTH cells. Copper and dexamethasone were ineffective in inducing MT mRNA in 5-azacytidine-treated CHSE cells. These results indicate that MT is specifically induced in response to heavy metal treatment, whereas the synthesis of hsp70 appears to be a general stress response. Furthermore, MT is differentially regulated by heavy metals and dexamethasone in these cell lines and the expression of MT is cell-type-specific.

Animals↗

Evaluation of antileishmanial activity of trans-aconitic acid.

TAA, an inhibitor of the enzyme aconitase, inhibits the growth of L. donovani promastigotes. Morphogenic transformation of the amastigote to the promastigote (table; see text) form in vitro was also inhibited by 2 mM TAA. TAA also reduced multiplication of the parasite in macrophage culture. In the hamster model of leishmania, TAA significantly reduced the parasitic burden of liver. In acute toxicity tests with BALB/c mice no deaths were recorded even at a dose level of 2 g/kg body wt/day.

Aconitic Acid↗