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Biomedical subjects

P Dutta

Publications and source records attributed to P Dutta.

At least 91 records · Page 5Linked to original sources
PubMed1997

Biting behaviour and biting rhythm of potential Japanese encephalitis vectors in Assam.

Studies on biting behaviour and biting cycles of medically important mosquitoes were carried out in Madhupur village and Tarajan tea estate of upper Assam. Collections were made off human baits outdoors and indoors and off cattle bait outdoors from August 1991 to July 1992. Human bait collections were performed using the 'stationary direct bait' technique. A total of 9,072 adult host seeking female mosquitoes representing 26 species and 5 genera were collected off baits of which 36.9% were collected off human baits and the rest from cattle. All mosquitoes were primarily zoophilic, although significant numbers were collected biting man outdoors. Biting preferences of important Japanese encephalitis (JE) vectors for man and cattle were studied using outdoor man:outdoor cattle ratio (attraction ratio = AR). Culex quinquefasciatus was attracted towards human baits the most (AR = 8.1:1), followed by Cx. bitaeniorhynchus (AR = 1.6:1) and Mansonia annulifera (AR = 1.3.1). The hourly biting activity of important JE vectors throughout the night on two bait types was also studied using three point moving averages. Hierarchical agglomerative cluster analysis was used to compare and classify mosquitoes on the basis of their similarity in biting rhythms.

Animals↗
PubMed1997

ERCP in situs inversus: do we need to turn the other way?

Endoscopic procedures are difficult in patients with situs inversus owing to left-right reversal of viscera. Conventionally, reversal of the position of the endoscopist in relation to the patient is advocated to overcome the anatomical difficulty. We describe a patient with chronic calcific pancreatitis and pseudocyst of the pancreas who had situs inversus. ERCP was performed with minor modification of maneuvers with the patient in the usual left lateral decubitus and the endoscopist on the left of the table.

Adult↗
PubMed1997

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↗
PubMed1997

Binding of water and solute to protein-mixture and protein-coated alumina.

Extent of water vapour adsorption (n1) of gelatin and bovine serum albumin and their mixtures in different proportion respectively has been measured by isopiestic vapour pressure methods at various values of water activity (a1) ranging between zero and unity. Similar measurements have also been carried out with gelatin and BSA coated alumina powder. At a given value of a1, n1 for the protein mixture is found to be significantly less than their ideal value obtained from the additivity rule. Such decrease is probably due to the protein-protein interaction as a result of which some of the water binding sites become unavailable for water vapour adsorption. On the other hand when a protein is mixed with alumina powder, the water vapour adsorption of the protein coated alumina surface at a given water activity is found to be 2 to 3 times larger than its ideal value obtained from the additivity rule. The standard free energy changes for hydration of protein mixtures and protein-coated alumina have been evaluated using Bull equation. The extent of excess hydration of these proteins and their mixtures as well as protein-coated alumina in the presence of excess neutral salts and urea respectively have been evaluated using the isopiestic method. In all cases, the moles of water and solute respectively bound in absolute amount to biopolymers, biopolymer mixtures and protein-coated alumina have been evaluated in the limited range of solute concentrations in the medium. Based on the Gibbs-Duhem equations, a rigorous expression for the standard free energy change for binding of excess solute and solvent to biopolymer have been evaluated with reference to unit solute mole fraction as standard state. Free energies of excess hydration of different biopolymer systems have been evaluated using this equation.

Aluminum Oxide↗
PubMed1996

Reduction of stress nonuniformities by apodization of compressor displacement in elastography.

Elastography is a method for imaging the elastic properties of compliant tissues that produces gray-scale strain or elasticity images called elastograms. The method is based on external tissue compression, with ultrasonic detection of local target displacements and subsequent computation of strain profiles along the compression axis. The internal strain variations are a result of the tissue elasticity variations and the applied deformation or compression. A number of mechanical artifacts that appear in elastograms have been identified. One such artifact appears as the result of a nonuniform stress distribution under the compressors used, including darkening (low stress) of the central region and brightening (high stress) of the peripheral regions under the compressor. On an elastogram, these areas may be misinterpreted as being respectively harder and softer than the rest of the target. In this article, a displacement apodization method for the minimization of this artifact is discussed, and its effects are studied using finite element simulations. When the isometric compression of standard elastography was replaced by an apodized displacement profile calculated from reciprocity conditions, a significant improvement in stress uniformity under the compressor was achieved.

Artifacts↗
PubMed1996

Thermodynamics of water-lipid interaction in presence and absence of salts.

Extents of hydration of different lipids such as cholesterol, lecithin, lysolecithin, gangliosides, hydroxy cerebrosides, sphingomyelin, Dalda (hydrogenated fat), coconut oil and sunflower oil in the presence and absence of some inorganic electrolytes, sucrose and urea have been studied using the isopiestic vapour pressure technique. Except triglycerides, the shape of the water vapour adsorption isotherms for other lipids are in agreement with type II or type III BET isotherms respectively. The overall shape of each curve for triglycerides does not agree with any of the shapes of five types of BET isotherms. At water activity (1) approaching unity, maximum number of moles of water bound (delta n1zero) per mole of cholesterol are 1.6 and 2.6 at 28 degrees C and 37 degrees C, respectively. Values of delta n1zero at 23 degrees C stand in the following order: Ganglioside > lysolecithin > sphingomyelin > hydroxy cerebrosides. For triglycerides n1 increases with increase of a1 and reaches maximum in between 0.95 to 0.98 beyond which it sharply decreases to zero as a1 approaches unity. Standard free energy changes (delta Gzero) and enthalpy changes (delta Hzero) for cholesterol and lysolecithin have been evaluated from the experimental data. The excess hydration of cholesterol in the presence of several inorganic salts, urea and sucrose have been estimated from isopiestic experiments and free energies of excess hydration have been evaluated.

Lipids↗
PubMed1996

Feeding patterns of Anopheles dirus, the major vector of forest malaria in north east India.

The feeding behavior of Anopheles dirus, the forest breeding, major malaria vector in northeast India was studied. The analysis of blood meals collected from this mosquito revealed that the species was highly anthropophilic in nature, the anthropophilic index being 90.5. The results of bait collection on human and cattle bait also confirmed its biting preference for human hosts. The species was observed to land on human bait throughout the night, showing prominent biting time at 20.00-21.00, 23.00-24.00 and 02.00-03.00 hours during the study period.

Animals↗
PubMed1996

Role of some environmental factors in modulating seasonal abundance of potential Japanese encephalitis vectors in Assam, India.

Temporal changes in the abundance of host-seeking, potential Japanese encephalitis (JE) vector mosquitos and the role of some ecological factors that are modulating the abundance of vector mosquitos were studied. Vector surveillance was conducted for one year in 4 JE prone villages of Dibrugarh, Assam. Among potential JE vectors, the most abundant mosquito was Culex vishnui s.s. comprising about 22.32%. Maximum density of the mosquito was found during the month of April and another peak was observed in the month of September. The influence of meteorological factors on the abundance of JE vectors was found to vary from species to species. The final multiple regression equations (after variables were selected using STEPWISE procedure) consisted of a combination of linear, quadratic, cubic and interactive ecological variables and accounted for 25-98% of the variations in the abundance of JE vector mosquitos. Complex interactions among environmental factors, such as minimum and maximum temperature, rainfall and flood level are involved in modulating the seasonal abundance of mosquitos. A time lag is involved before a cause and effect relationship is established between environmental parameters (independent variables) and entomological variables (dependent variables). Inundation caused by flooding is favorable for mansonioid mosquito species whereas it has an adverse effect on non-mansonioid mosquito species.

Animals↗
PubMed1995

Risk factors for development of dehydration in young children with acute watery diarrhoea: a case-control study.

In a case-control study to understand the risk factors for development of life-threatening dehydration, a total of 379 children comprising 243 cases (moderate or severe dehydration) and 136 controls (non or mild dehydration) up to 2 years of age suffering from acute watery diarrhoea were studied. By univariate analysis, the presence of vibrios in stool, withdrawal of breast feeding during diarrhoea, not giving fluids, including oral rehydration solution (ORS), during diarrhoea, frequent purging ( > 8/day), vomiting ( > 2/day) and undernutrition were identified as risk factors. However, by multivariate analysis after controlling for confounders, withdrawal of breast feeding during diarrhoea (odds ratio (OR) = 6.8, p < 0.00001) and not giving ORS during diarrhoea (OR = 2.1, p < 0.006) were identified as significant risk factors. The confounding variables which also contributed significantly to increasing the risk were age ( < or = 12 months; OR = 2.7, p = 0.001), frequent purging ( > 8/day; OR = 4.1, p < 0.00001), vomiting ( > 2/day; OR = 2.4, p = 0.001) and severe undernutrition (%median < or = 60 weight-for-age of Indian Academy of Paediatrics classification; OR = 3.1, p = 0.001). We feel that these findings will be useful for Global and National Diarrhoeal Diseases Control Programmes for formulating intervention strategies for preventing death due to diarrhoeal dehydration.

Acute Disease↗
PubMed1995

Efficacy of ciprofloxacin in enteric fever: comparison of treatment duration in sensitive and multidrug-resistant Salmonella.

The efficacy of two regimens of ciprofloxacin was compared in a randomized study conducted on 69 patients with enteric fever, 52.2% of whom had infection with multidrug-resistant (MDR) strains of Salmonella typhi or S. paratyphi. Patients were randomly assigned to two regimens (10 days versus 14 days) of ciprofloxacin (500 mg twice a day). The mean +/- SD time required for defervescence was similar for both regimens (4.2 +/- 1.9 days in the 10-day group and 4.9 +/- 2.6 days in the 14-day group). A 100% cure was observed in each treatment group and no serious side effects were observed. Relapse occurred in two patients (14-day regimen). Only one patient (14-day regimen) had growth of S. typhi in stool culture at the time of the first follow-up three days after completion of therapy. Follow-up studies on available patients on two, six, and 12 months after completion of therapy revealed that all patients had negative stool cultures for S. typhi and S. paratyphi. This study indicates that ciprofloxacin may be recommended as an initial therapy for enteric fever for adult men and nonpregnant and nonlactating women in areas where MDR strains of S. typhi and S. paratyphi are prevalent, and that 500 mg twice a day of the drug given for 10 days is as effective as 14 days at the same dosage.

Adolescent↗
PubMed1995

Filariasis in the labour population of a tea estate in Upper Assam.

Preliminary random and mass blood surveys undertaken between 2000-0100 h in a tea garden of Upper Assam revealed more than 8 per cent positivity for microfilaria (mf) of Wuchereria bancrofti. The mf carriers were considerably high among males (73) as compared to females (48). Culex quinquefasciatus was incriminated as a vector with man hour density of 68.5 in human dwellings (indoors). The detection of mf in children who had never moved from the area and filaria larvae in vector mosquitoes collected from human dwellings indicate that indigenous transmission is going on in the garden and that filariasis has become a local health problem.

Adolescent↗