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Biomedical subjects

B Mohanty

Publications and source records attributed to B Mohanty.

At least 19 recordsLinked to original sources

Laboratory based approaches for arsenic remediation from contaminated water: recent developments.

Arsenic contamination in water has posed severe health problems around the world. In spite of the availability of some conventional techniques for arsenic removal from contaminated water, development of new laboratory based techniques along with enhancement and cost reduction of conventional techniques are essential for the benefit of common people. This paper provides an overview of the arsenic issue in water such as modes of contamination of ground water as well as surface water by arsenic, its metabolism and health impacts, factors influencing arsenic poisoning, fundamentals of arsenic poisoning mechanism and world scenario of arsenic poisoning. It discusses and compares the conventional laboratory based techniques, like precipitation with alum, iron, Fe/Mn, lime softening, reverse osmosis, electro dialysis, ion exchanges, adsorption on activated alumina/carbon, etc., for arsenic removal from contaminated water. It also discusses the best available techniques and mentions the cost comparison among these techniques too. Recent developments in the research on the laboratory based arsenic removal techniques, like improvement of conventional techniques and advances in removal technology along with its scopes and limitations have also been reviewed.

Adsorption↗

Interferometry of direct photons in central 208Pb + 208Pb collisions at 158A GeV.

Two-particle correlations of direct photons were measured in central 208Pb+208Pb collisions at 158A GeV. The invariant interferometric radii were extracted for 100<K(T)<300 MeV/c and compared to radii extracted from charged pion correlations. The yield of soft direct photons, K(T)<300 MeV/c, was extracted from the correlation strength and compared to theoretical calculations.

Journal Article↗

Anomalous self-assembly of gelatin in ethanol-water marginal solvent.

Light scattering, rheology, and atomic force microscope (AFM) studies have been performed on solutions of a polyampholyte (gelatin) prepared in water-ethanol marginal solvent. At ethanol concentration approximately 45+/-2% v/v anomalous aggregation led to formation of fractal (on hydrophilic substrates; glass, quartz and silicon) aggregate of polypeptide molecules having fractal dimension d(f) in 2D=1.60+/-0.08. The time evolution morphology of these self-assembled and self-organized structures formed on hydrophilic substrates was driven by selective ethanol evaporation and was observed by an AFM. These fractal aggregates eventually transformed into near-spherical clusters with fractal corona having same fractal dimension (d(f)=1.58+/-0.05) and finally, the corona separated and regular aggregates were formed. The kinetics of aggregation on substrates could be modeled through random sequential adsorption of particles with continuum power-law size distribution. The temporal growth of aggregate hydrodynamic radius R(h)(t) and scattered intensity I(s)(t) measured in the bulk were observed to exhibit; R(h)-t(z) and I(s)-t(z)-with z=1/d(f), giving a fractal dimension d(f) in 3D approximately equal to 2.6+/-0.2, which is discussed within the framework of Smoluchowski aggregation kinetics. This growth in R(h) is accompanied by narrowing down of the particle size distribution. Solution rheology at this ethanol concentration revealed minimum thixotropy and maximum infinite shear viscosity features.

Journal Article↗

Comparative incidence of venous air embolism and associated hypotension in adults and children operated for neurosurgery in the sitting position.

BACKGROUND AND OBJECTIVE: Venous air embolism is a constant threat during neurosurgery performed in the sitting position. No large prospective study has compared the incidence of venous air embolism and associated hypotension between adults and children. METHODS: Four hundred and thirty patients (334 adults, 96 children) scheduled to undergo planned posterior fossa surgery in the sitting position (between January 1989 to December 1994) were studied with end-tidal carbon dioxide monitoring. Intraoperatively, a sudden and sustained decrease in end-tidal carbon dioxide tension of >0.7 kPa was presumed to be due to venous air embolism. Management during the episode was on the established guidelines. Hypotension (decrease in systolic arterial pressure of 20% or more from the previous level) was treated with crystalloids and/or a vasopressor. RESULTS: Capnometry detected a 28% incidence rate of air embolism in adults (93/334) and a 22% incidence rate in children (21/96) (P = 0.29). In both groups, the highest incidence rate of embolism took place during muscle handling (44% of adults versus 38% of children, P = 0.8). Embolic episodes were accompanied by hypotension in 37% of adults (34/93) and in 33% of children (7/21) (P = 0.98). To restore arterial pressure to pre-embolic levels, 53% of adults (18/34) and 43% of children (3/7) were administered vasopressors (P = 0.94). There was no intraoperative mortality. The surgical procedure on one adult was abandoned because of persistent hypotension following the embolic episode. CONCLUSION: The incidence of venous air embolism and consequent hypotension is similar in adults and children.

Adult↗

Reduction of mechanical heart valve thrombosis through a clinical audit.

BACKGROUND AND AIM OF THE STUDY: Patients with mechanical heart valves implanted at four cardiothoracic centers were followed up in a hospital in Eastern India. Despite successful surgery and regular hospital visits, long-term survival was compromised by anticoagulation-related complications. METHODS: Systematic analysis revealed under-anticoagulation in most patients. Thrombosis risk in 80 patients on regular follow up from 1989 to 1997 was 8.68 per 100 patient years (pt-yr). The incidence of both thrombotic and bleeding complications was reported as less than two per 100 pt-yr, when prothrombin time was consistently in the range of INR 2.5 to 3.9. In targeting this low event rate, impediments to optimum anticoagulation in the local set-up were identified. International Normalized Ratio (INR) was introduced to report prothrombin time (PT). Patients and doctors were educated about drug and diet interactions with oral anticoagulants (OAC) and the early features of valve thrombosis. Treatment protocols were evolved. The impact of the remedial measures was studied in 81 patients (64 old, 17 new) over a total of 254 pt-yr of follow up, from 1998 to 2001. RESULTS: Thrombosis risk was reduced from 8.68 to 5.12 per 100 pt-yr, while non-fatal bleeding events increased from 0.28 to 1.96 per 100 pt-yr. Due to early recognition of occlusive prosthetic valve thrombosis and institution of fibrinolytic therapy, fatal events were reduced from 3.8 per 100 pt-yr to none for four consecutive years (statistically significant at 99% CI). CONCLUSION: The clinical audit proved to be a valuable tool for understanding the problems in health care delivery, and bringing about improvement.

Administration, Oral↗

Bleeding complication during coumarin therapy due to amiodarone and azithromycin.

A patient with mechanical heart valves developed bleeding, after the introduction of amiodarone and azithromycin. Though the anticoagulant effect could be neutralized, the patient succumbed to heart failure. Any new drug prescribed to patients on anticoagulant must be assessed for its potential for interaction and warrants frequent prothrombin time testing.

Amiodarone↗

Immunocytochemistry of the pars tuberalis of the pituitary gland in some Indian wild birds: a comparative study.

Immunohistochemistry has been applied to the cells of the pars tuberalis (PT) of the pituitary gland of three species of Indian wild birds (Halcyon smyrnensis perpulchra, Lonchura striata striata, Dicrurus adsimilis macrocercus). As in the pars distalis (PD), five types of immunoreactive cells (gonadotropic, GTH; thyrotropic, TSH; lactotropic/prolactin, PRL; growth hormone/somatotropic, STH; and cortico-melanotropic, ACTH/MSH cells) are present in the PT of these birds. In addition to the GTH cells, immunoreactive TSH, PRL, STH, and ACTH/MSH cells are present in the avian PT. The GTH cells are the predominant cell population of the PT. Other immunoreactive cells, though less numerous, are also present, unlike their inconsistent occurrence in several mammalian PTs. Though immunologically related, the PT cells distinctly differ from their counterparts in the PD with regard to their morphology, intensity of immunoreaction, and cellular arrangement.

Adrenocorticotropic Hormone↗

Immunoelectron microscopy of corticotropes and melanotropes in the pituitary gland of the European ferret, Mustela putorius furo.

The superimposition technique and protein A-gold method of immunoelectron microscopy were employed to study the ultrastructure of corticotropes as well as melanotropes in the ferret pituitary gland. This is the first study ever elucidating the ultrastructural heterogeneity of melanotropes in mammalian pars intermedia on an immunocytochemical basis. Morphological heterogeneity of pars distalis corticotropes has also been elucidated. It is suggested that the different subtypes may represent stages of development (histogenesis), or functional phases of a single cell type. In addition, the occurrence and distribution of both corticotropes and melanotropes in different hypophyseal components have been studied by light-microscopic immunocytochemistry.

Adrenocorticotropic Hormone↗

Light- and electron-microscopic immunocytochemistry of somatotropes in the anterior pituitary gland of European ferret, Mustela putorius furo.

Light-microscopic immunocytochemistry of ferret anterior pituitary revealed the localization of somatotropes in the pars distalis, but no immunoreactive cells were detected in the pars tuberalis. Ultrastructural studies by superimposition immunocytochemistry and immuno-electron microscopy, elucidated the morphological heterogeneity of these somatotropic cells. They were classified into 2 subtypes on the basis of size of the secretory granules. Type-I cells with small granules (mean diameter, 192 nm), were considered to be the immature somatotrop, while Type-II cells, with comparatively larger secretory granules (mean diameter, 257 nm), were considered to be the matured form of Type-I cells and the typical somatotropic cell-type, and were much more predominant than the Type-I cells. The fact that Type-II cells had a distinct Golgi zone and many mitochondria, while in Type-I cells the intracellular organelles were generally less developed, supports this suggestion. In addition to these two extreme subtypes, several intermediate forms were also encountered that may represent different transitional phases during the conversion of Type I to Type II. Protein A-gold immuno-electron microscopy illustrated the specific localization of growth hormone over the granules, with no labelling over any other cytoplasmic organelles of the 2 somatotrope subtypes.

Animals↗

Monitoring of temephos (abate) application as a cyclopicide under the guineaworm eradication programme in India.

Temephos application in unsafe water sources at a dose of 1ppm, which started in 1986, is an important activity of the guineaworm eradication programme in India. During March 1989, monitoring of temephos application was carried out in six villages in each of the five guineaworm endemic districts: Kurnool (Andhra Pradesh), Gulbarga (Karnataka), Dhar (Madhya Pradesh), Thane (Maharashtra) and Jhalawar (Rajasthan), selected for the study. Out of 62 unsafe water sources targeted in the sampled villages for temephos treatment, 43 were treated during 1989 in the five districts (coverage 69.35 per cent). Out of these 43 treated sources 79.1 per cent were free of cyclops and the rest 20.93 per cent showed a variable cyclops count. 117 adult cyclops identified from these sources included Mesocyclops byalinus (82) and M. leuckarti (35). People's perception of utility of chemical treatment of water sources varied from negligibly low to moderate levels. Those areas which received timely application of temephos during the preceding year, al sharp decline in the number of cases in 1989 was observed. However, in those villages where no temephos was applied or where application was started as late as April or May, there was no impact on prevalence of the disease.

Animals↗