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Biomedical subjects

M Sengupta

Publications and source records attributed to M Sengupta.

At least 19 recordsLinked to original sources

Correction to Microscopically Determined Particle Size According to Diffraction Correction Theory.

The theory of diffraction correction for transparent (phase) spherical particles under partially coherent illumination has been applied to the optical photomicrographic determination of particle size distribution for four different nearly monodisperse polystyrene latex samples. The thus corrected particle size distribution for each sample has been compared with the corresponding electron microscopic determination. Copyright 1999 Academic Press.

Journal Article↗

The Primary Electroviscous Effect in Polystyrene Latices of Small Particle Size Range Prepared with the Addition of Anionic Surfactant as Emulsifier. Effect of Increasing Concentrations of Quaternary Ammonium Counterions of Different Ionic Sizes and Stability Characteristic of the Latices and the Latex-Electrolyte Mixtures.

Polystyrene latices were prepared by the emulsion polymerization method using hydrogen peroxide as an initiator and sodium dodecyl sulfate as the emulsifying agent. Latices of different particle sizes were prepared by the seeded growth technique. The particle size and its frequency distribution were determined by electron microscope. The viscosities and electrophoretic mobilities of the latex and latex:added electrolyte mixtures were measured in the presence of gradually increasing concentrations of quaternary ammonium counterions of different ionic sizes. The zeta-potentials were calculated by the computational method of Wiersema-Loeb- Overbeek (WLO); the surface charge densities sigma were calculated by the method of Loeb-Wiersema-Overbeek (LWO). The primary electroviscous effects were calculated by using the Booth equation. The free energies of adsorption Delta&Gmacr;ads of the counterions on the particle surface were calculated. The stability characteristic of the latices and latex-added electrolyte mixtures has been studied on the basis of the DLVO theory. Copyright 1998 Academic Press.

Journal Article↗

Multi-drug resistant typhoid fever with diarrhea.

OBJECTIVE: To provide information about the characteristics of diarrheal stool in multi-drug resistant typhoid fever and observe the clinical course after treatment with furazolidone or ciprofloxacin. SETTING: Hospital based. SUBJECTS AND METHODS: Twenty one male children who were positive for multi-drug resistant S. typhi by blood and stool cultures, having diarrhea at the time of hospitalization comprised the subjects. Serum and stool electrolytes were estimated. Stool samples were also processed to detect established enteropathogens, leukocytes and red blood cells. Children were treated either with furazolidone or ciprofloxacin and evaluated till recovery. RESULTS: Mean (+/- SD) pre-admission duration of fever and diarrhea of these cases were 19.1 (+/- 5.6) and 15.8 (+/- 4.6) days, respectively. Stool character in 81% of the patients was watery with mean (+/- SD) volume of stool 51.4 (+/- 25.1) ml per kg body weight in the first 24 hours of observation. Leukocyte count varied between 20-49 per high power field in 66.7% stool samples. Occult blood was present in only 19% cases. Fecal red blood cells in high power field were detected in 52.4% cases. Mean fecal electrolytes (mmol/liter) were as follows: sodium-53.8, potassium-51.4, chloride-41.6 and total CO2-24.3. Most of the children (71.4%) had no dehydration and had normal serum electrolytes. The isolated strains of S. typhi were multi-drug resistant. These children were treated successfully either with furazolidone or ciprofloxacin. CONCLUSION: The stools of multi-drug resistant typhoid fever patients were watery with little blood. Their electrolyte contents were more similar to the diarrheal stool seen in shigellosis rather than cholera. Uncontrolled observations revealed that children recovered with furazolidone or ciprofloxacin therapy.

Anti-Infective Agents↗

Correlation of biological activity (therapeutic and toxic) with solvochromic properties of metronidazole, emetine hydrochloride and diloxanide furoate.

Goat blood, when incubated for different periods with diloxanide furoate, metronidazole and emetine hydrochloride, underwent changes in fatty acid constituents and their peroxidation products measured as malonaldehyde. These findings, together with the changes noted in the drug-lipid partition coefficient, are discussed in an attempt to correlate the lipid constitution and biological activity of the drugs.

Amebicides↗

Dengue haemorrhagic fever (DHF) outbreak in Calcutta--1990.

An outbreak of Dengue Haemorrhagic Fever (DHF) occurred in Calcutta between September and December, 1990. Children and young adults were the major victims. Haemorrhagic manifestations and shocks were the main features in most of the hospitalised cases. Five mouse pathogenic agents were isolated from 105 acute cases and all were identified as DEN-3. HI and CF test with 55 paired sera revealed evidence of dengue infection in 33 (60 per cent) and flavivirus group reaction including dengue in 17 (30.9 per cent). It was for the first time, that DEN-3 was considered to be the etiologic agent for DHF in Calcutta.

Adolescent↗

Effect of propranolol hydrochloride on blood cell lipids in relation to partition coefficient and biological activity.

Considering the high lipophilicity of propranolol (log P = 3.56), its interactions with the cell membrane lipids of goat blood have been investigated. It is observed that lipid loss after incubation of blood cells with propranolol hydrochloride in salt glucose medium for varying periods of time was accompanied with significant increases in PUFAs. Amongst the PUFAs studied the omega 3 and omega 6 fatty acids, the two important precursors of eicosenoids, have shown increase in varying amounts. This phenomenon is presumably responsible for the significant cardiovascular activity of this drug.

Animals↗

Correlation of phospholipid loss in goat whole blood with solvochromic properties of antiamebics like emetine, metronidazole and diloxanide furoate.

Phospholipid content of whole blood lipid decreases significantly when goat blood is incubated for different length of time with different amebicidal agents (e.g., emetine, metronidazole and diloxanide furoate). The plots of relative per cent phosphate loss against incubation period show biphasic nature and suggest that the rates of phospholipid loss bears some relation with the drug's lipophilicity (log P in 1 octanol/water system). The absolute phospholipid loss seems to be governed by the drug's aquasolubility. Implication of these finding were discussed in terms of their clinical profiles assuming that the loss of phospholipid is due to drug's binding with the phospholipid layer in amebic cyst-coat, being the first step which may trigger a chain of events leading to the onset of drug action.

Amebicides↗

Effect of lignocaine on blood lipid in relation to partition coefficient and biological activity.

To correlate lipophilicity of lignocaine with changes in lipid composition of blood as a result of in vitro incubation with the drug, phosphorus content and fatty acid compositions of blood lipids before and after lignocaine treatment have been compared with those of a standard phospholipid, lecithin, under similar conditions of drug treatment. The change in fatty acid constituents has been correlated with the biological activity (both therapeutic and toxic) of lignocaine.

Animals↗

Effect of isosorbide dinitrate on enzymatically estimated infarction size and on clinical condition of the patients of acute myocardial infarction.

With the aim of reducing myocardial infarction size, isosorbide dinitrate (ISDN) was tried in 27 patients of acute myocardial infarction (AMI). There was 11% reduction of infarction size, in the ISDN treated group, in comparison to that of non treated group, though the result was not statistically significant. But, many of the in-hospital complications were significantly less in the treated group. After a critical analysis of the result it was concluded that a statistically insignificant result, as regard reduction of infarction size in AMI, cannot always exclude the utility of a drug therapy in AMI.

Creatine Kinase↗