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Biomedical subjects

B P Das

Publications and source records attributed to B P Das.

At least 19 recordsLinked to original sources
PubMed2006

Electric quadrupole moments of the D states of alkaline-earth-metal ions.

The electric quadrupole moment for the 4d(2)D(5/2) state of (88)Sr(+); one of the most important candidates for an optical clock, has been calculated using the relativistic coupled-cluster theory. This is the first application of this theory to determine atomic electric quadrupole moments. The result of the calculation is presented and the important many-body contributions are highlighted. The calculated electric quadrupole moment is (2.94 +/- 0.07)ea(2)(0), where a(o) is the Bohr radius and the electronic charge while the measured value is (2.6 +/- 0.3) ea(2)(0). This is so far the most accurate determination of the electric quadrupole moment for the above mentioned state. We have also calculated the electric quadrupole moments for the metastable 4d(2)D(3/2) state of 88(Sr(+) and for the 3d(2)D(3/2.5/2) and 5d(2)D(3/2.5/2) states of (43)Ca(+) and (138)Ba(+), respectively.

Journal Article↗
PubMed2006

Relativistic coupled-cluster theory of atomic parity nonconservation: application to 137Ba+.

We report the result of our ab initio calculation of the 6s2S1/2-->5d2D3/2 parity nonconserving electric dipole transition amplitude in 137Ba+ based on relativistic coupled-cluster theory. Considering single, double, and partial triple excitations, we have achieved an accuracy of less than 1%. If the accuracy of our calculation can be matched by the proposed parity nonconservation experiment in Ba+ for the above transition, then the combination of the two results would provide an independent nonaccelerator test of the standard model of particle physics.

Journal Article↗
PubMed2005

Distribution of Plasmodium falciparum genotypes in clinically mild and severe malaria cases in Orissa, India.

A cross-sectional study was conducted in a malaria hyperendemic state of India to ascertain the distribution of Plasmodium falciparum genotypes in patients with mild (n=40) and severe (n=35) malaria. PCR and nested PCR were used to determine the glutamate-rich protein (GLURP), merozoite surface proteins 1 and 2 (MSP1 and MSP2) and knob-associated histidine-rich protein (KAHRP) for characterization of the parasite. The results indicate that (i) the 200bp allele of the MAD20 family of MSP1 and the 550bp allele of the 3D7 family of MSP2 show over-representation in severe malaria cases; (ii) the multiplicity of infection with respect to MSP2 alleles is significantly higher (P<0.001) in severe cases than in mild cases; and (iii) comparison with the findings of other studies leads to the conclusion that the distribution of P. falciparum genotypes between different clinical groups differs geographically.

Adult↗
PubMed2005

Knowledge, attitudes and practices (KAP) regarding the management of diarrhea by pharmacists and licensed drug sellers in eastern Nepal.

Diarrhea constitutes a major cause of morbidity and mortality in developing countries. Inappropriate drug prescribing is common in diarrhea, resulting in an increase in cost and adverse drug reactions. In Nepal, drug sellers often act as the first contact persons for the underprivileged. No information has been available regarding their knowledge, attitudes and practices (KAP) regarding diarrhea management. Using a structured questionnaire, between the 1st of January and the 31st of December 2003, 109 drug sellers in eastern Nepal were interviewed about their educational status, patient/attendant presentation at the outlet and their advice to patients/attendants. Only 2.7% of drug sellers were qualified in health education. Eighty percent of the patients/attendants sought advice from the drug sellers, only 20% presented to the outlet with prescriptions. The data reveals that about half of them were taking note of the nature of the diarrhea. Although 62 (56.8%) of them were aware of dehydration, only 2 (1.8%) of them knew all three signs of dehydration (dry tongue, non-elastic skin and sunken eyes). Sixty-six (60.5%) of them knew about oral rehydration solution (ORS), its principle and the required period of administration. About 50 to 60% of them were aware of the implications resulting from dehydration from uncontrolled diarrhea and of the importance of ORS in its management. Only 20% of the drug sellers advised ORS alone, otherwise it was dispensed along with drugs, such as antimotility agents (AMA) or metronidazole. As a result of the above findings, it is important to educate the drug sellers by conferring knowledge about the ethical aspects of drugs in the management of diarrhea.

Attitude of Health Personnel↗
PubMed2005

First time detection of Japanese encephalitis virus antigen in dry and unpreserved mosquito Culex tritaeniorhynchus Giles, 1901, from Karnal district of Haryana state of India.

Japanese encephalitis virus (JEV) antigen has been detected by antigen capture enzyme linked immunosorbentassay (ELISA) in dry specimens of the mosquito Culex tritaeniorhynchus Giles, 1901, collected from Karnal district of Haryana state in northern India. These mosquitoes were stored in dry condition for 20 months, at room temperature, before processing. The procedure of detecting JEV infection in long time stored, dry vector mosquitoes, has important application in the surveillance of Japanese encephalitis.

Animals↗
PubMed2005

Entomological indices of Aedes aegypti at some international airports and seaports of southern India--a report.

Entomological surveys were undertaken at some of the international airports/seaports (Bangalore, Calicut, Chennai, Cochin, Thiruvanathapuram and Vishakapatnam) to find out the breeding prevalence of dengue vector mosquito in diverse breeding containers from 1998 to 2004. Three vector indices (House index, Container index and Breateu index) were used to assess the breeding potential at each airport/seaport. International Health Regulations urged national governments to keep all the international airports/seaports and peripheral areas up to 400 meters free from Aedes aegypti mosquitoes. However, surveys revealed high vector indices at all the airports and seaports. Health authorities of airports/seaports need to take cognizance of these facts and develop action plan for appropriate control measures with emphasis on vector surveillance.

Aedes↗
PubMed2004

The PfCRT (K76T) point mutation favours clone multiplicity and disease severity in Plasmodium falciparum infection.

In Orissa, a malaria-hyperendemic area of India, we assessed the relationship between the PfCRT (K76T) point mutation of Plasmodium falciparum and the clinical severity of malaria. Forty uncomplicated and 36 severe malaria cases were selected, and parasite species, density and schizontaemia determined by examination of Giemsa-stained thick or thin blood films. The PfCRT point mutation was analysed by PCR-RFLP and genotypes of the parasite isolates investigated by nested PCR using the polymorphic region of the merozoite surface protein-2. We found that (i) the prevalence of the PfCRT point mutation was significantly higher (P < 0.01) in severe malaria cases and that (ii) heavy parasitaemia along with clone multiplicity was statistically more common (P < 0.01) in severe cases. These associations may be due to progression of uncomplicated to severe disease after chloroquine treatment failure and/or increased virulence of chloroquine-resistant parasites. The implications for antimalarial treatment policy are discussed.

Adult↗
PubMed2003

Effect of nimodipine, a dihydropyridine calcium channel antagonist on the pharmacokinetics of carbamazepine in rhesus monkeys.

Calcium channel antagonists have been shown to have an anticonvulsant activity in a variety of seizure models and also to potentiate the anticonvulsant activity of other standard antiepileptic drugs like carbamazepine, phenytoin and valporoate. A pharmacokinetic interaction may be involved in such potentiation. This cross over single dose study was carried out to find out if there was a pharmacokinetic interaction between carbamazepine, a commonly used antiepileptic drug and nimodipine, a dihydropyridine calcium channel antagonist in rhesus moneys. Carbamazepine 46 mg/kg and nimodipine 9.6 mg/kg was administered through a nasogastric tube and blood samples were collected at 0.5, 1, 2, 3, 6, 9, 12, 24, 48, 72 and 96 hours after drug administration and were assayed for carbamazepine. Nimodipine caused a significant increase in peak plasma concentration (C(max)) of carbamazepine and a decrease in plasma absorption half life (t1/2 alpha). There was no significant change in other pharmacokinetic parameters between the two groups. The results of the study suggest that concurrent administration of carbamazepine and nimodipine may cause a significant rise in carbamazepine concentration as may contribute to a potentiation of anticonvulsant effect of carbamazepine and an increase in the incidence of adverse effects warranting that nimodipine should be prescribed cautiously in epileptic patients receiving carbamazepine and it might be very appropriate to do therapeutic drug monitoring of carbamazepine in such patients.

Animals↗
PubMed2001

Clinical evaluation of human placental extract (placentrex) in radiation-induced oral mucositis.

To evaluate human placental extract in the treatment of radiation mucositis involving the oral/oropharyngeal region, a prospective randomized study was carried out in 120 patients with squamous cell carcinoma of the head and neck from August 1997 to March 1999. The study was conducted in patients receiving radical external radiation therapy, planned for = > 60 Gy/30 F/6 weeks, who developed grade 2 radiation mucositis (patchy mucositis) during radiation treatment. The patients were randomized in two groups of 60 patients each to receive either placentrex treatment (placentrex group) or conventional treatment (control group). Placentrex treatment was given as Inj Placentrex 2 ml by deep intramuscular injection 5 days a week for 15 injections. Conventional treatment given in the control group was disprin gargles and betamethasone oral drops. A subjective decrease in pain was observed in 48/60 (80%) of patients in the placentrex group compared with 22/60 (36.7%) in the control group. The progression to grade 3 radiation mucositis was 24/60 (40%) in the placentrex group compared with 52/60 (86.7%) in the control group. The subjective improvement in difficulty in swallowing was seen in 56/60 (93%) of patients in the placentrex group compared with 9/60 (15%) of patients in the control group. Only one patient in the placentrex group compared with three in the control group required interruption of radiation therapy because of severe radiation reactions. Human placental extract appears to be effective in the management of radiation-induced oral/oropharyngeal mucositis and especially in controlling subjective symptoms.

Abnormalities, Radiation-Induced↗
PubMed2000

Comparison of two radiation dose schedules in post mastectomy carcinoma of the breast.

In 108 histopathologically proved breast cancer patients, after surgical treatment with modified radical mastectomy, two radiation dose schedules have been compared. Radiation therapy was given on a 60Co teletherapy machine using gent pair technique for chest wall irradiation and direct fields for lymphatic drainage areas. The patients were randomly divided into two groups (Group A and Group B). 54 patients were given external radiotherapy 40 Gy/17 F/3.2 weeks and remaining 54 patients were given 45 Gy/20 F/4 weeks. Results of treatment in Group A versus Group B were as follows; chest wall failure 5/50(10%) versus 3/54 (5.6%), axillary lymphnods failure 3/50(6%) versus 4/54(7%), distant metastasis 16/50(32%) versus 15/54(28%). Radiation reactions were almost similar in both the groups. Skin reactions were most common radiation effects [45/50 (90%) in Group A and 43/54 (79.6% in Group B]. Thus no statistically significant difference in local control and efficacy of these two radiation dose schedules was observed in postmastectomy carcinoma of the breast.

Adult↗
PubMed1998

Biochemical and histopathological changes in respiratory system of rats following exposure to diesel exhaust.

Effect of exposure to diesel exhaust (DE) for different durations was evaluated using histopathological and biochemical parameters in respiratory system of the rats. Animals were exposed to 1 part DE diluted with 5 parts of clean air in a simulation chamber for 15 min/day for 1, 7, 14 and 21 days. After completion of various exposures, biochemical parameters including elastase inhibitory capacity (EIC) and protein content of the bronchial airway lavage (BAL) and histopathological changes along with lung/body weight ratio were assessed. The elastase inhibitory capacity (an index of the protection against destruction of elastin, a lung connective tissue) was maximum at 1 week indicating thereby that the body renders protection against injury by increasing EIC levels in the initial phase. However, protein content in the BALF increased after 1 week and reached maximum at 2 weeks. Histopathological changes followed similar time course of pattern with accumulation of macrophages and protein exudation. Prolonged exposure up to 3 weeks, however was accompanied by chronic inflammatory changes and thickening of alveolar septa and blood vessels. Changes in lung/body weight ratio and suspended particulate matter (SPM) deposited on filters (simulation chamber) correlated well with EIC, protein content in BALF and histopathological changes. The biochemical findings accompanied with chronic structural changes in the lungs of rats following exposure to DE could be relevant to the clinical observation of increased incidence of chronic lung diseases after continued DE exposure.

Air Pollutants↗
PubMed1997

Comparative role of three-dimensional radiotherapy planning and inhomogeneity corrections in carcinoma of the tongue.

The authors have assessed the role of computerized three-dimensional (3-D) and traditional (TD) radiotherapy planning and inhomogeneity corrections in improving target volume coverage and normal tissue sparing in carcinoma of the tongue. Coverage of target volumes in 3-D versus TD plans revealed the following. Volume receiving 95% of dose, clinical target volume (CTV): 1-68% versus 0-24%; gross tumour volume-lymph nodes (GTV-l): 0-80% versus 0-20%; gross tumour volume-primary tumour (GTV-II): 0-65% versus 0-26%. Dose to 95% of target volume CTV 77-92% versus 76-87%; GTV-I: 81-90% versus 61-88%; GTV-II: 82-93% versus 68-87%. Minimum dose to 5% of target volume, CTV: 77-93% versus 74-81%; GTV-I: 81-90% versus 61-88%; GTV-II: 76-93% versus 68-87%. Minimum dose to a volume of no less than 5% of the target volume, CTV: 93-98% versus 88-96%; GTV-I: 87-100% versus 88-97%; GTV-II: 86-98% versus 88-96%. A new parameter (inhomogeneity difference) was devised to study target volume dose homogeneity and was found to be very useful. Dose to two-thirds of the parotid glands in 3-D versus TD plans showed a mean of 46 versus 65% for right parotid glands and 44 versus 56% for left parotid glands in all patients. Better tumour dose homogeneity, increased mean tumour dose, avoidance of geographic misses and better parotid sparing was achieved in 3-D plans as compared to TD plans. We could not demonstrate any role for inhomogeneity corrections using currently available computerized dose algorithms.

Carcinoma, Squamous Cell↗
PubMed1997

An equipment for the study of behavioural responses of mosquitoes to residual application of synthetic insecticides.

Excito-Repellency (E-R) Test Box was developed to study under laboratory conditions the refractory behaviour of mosquitoes to residual application of synthetic insecticides. The observations obtained through the equipment were compared with another behavioural study of mosquitoes using standard WHO irritability test kit. During 16 hour exposure period there was restricted entry of mosquitoes in DDT treated chamber of E-R test box for all mosquito species tested (Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus). Blood feeding success of An. stephensi was significantly low (20%) in DDT treated chamber as compared to untreated control chamber (77%). Of all the species tested in E-R test box, An. stephensi was found to be highly irritant to DDT inducing 80% exit rate as compared to that of 10% from control chamber. Similarly, results of irritability test demonstrated highest irritant behaviour of An. stephensi to DDT. The paper also includes a discussion on comparative efficacy of WHO irritability test kit and the present E-R Box.

Animals↗
PubMed1997

Effect of short and long-term exposure to diesel exhaust on sensitivity of guinea pig tracheal preparation to histamine.

Single exposure, to diesel exhaust (1 part exhaust diluted by 5 parts of clean air) reduced EC50 of histamine indicating hyperresponsiveness of the receptors in trachea of exposed guinea pigs. In contrast, following repeated exposure for 7, 14 or 21 days (15 min/day), EC50 was progressively increased indicating the possibility of down-regulated histamine receptors. Further, simultaneous significant increase in histamine levels (bioassayed on guinea pig ileum) in bronchial airway lavage fluid supports the aforementioned hypothesis. The change in lung/body weight ratio and suspended particulate matter deposited on filters followed the same temporal pattern as EC50. The findings are suggestive of differential effects of diesel exhaust on airway depending upon the duration of exposure.

Air Pollutants↗
PubMed1994

Field trial with redtop flycatcher baited with ready made protein meal for the control of houseflies in Gazipur dairy farm, Delhi.

A field trial with Redtop Flycatcher having bait formulated as ready made protein meal a.i 977 gms/kg was carried out for the control of adult housefly Musca domestica domestica L. in Gazipur dairy farm situated at eastern corner of Delhi and observation compared with another field trial with commonly available Baygon bait using scattering method. The observation recorded during the field trial revealed that the new flycatcher was capable of retaining the trapped flies and the protein bait remained active for a period of 35 to 42 days (with peak attractability around the ninth day) without requiring refilling the flycatcher with bait during this period. The flycatcher installed in indoor situation was found to be more effective than that kept outside. Parallel tests with Baygon bait containing 2 per cent Propoxur scattered @ 40 gms a.i/100 m2 were found to kill more flies than the new protein baited flycatcher but required daily replenishment of the insecticide. Fly attractancy of the protein sample was also compared with that of other food sources for the flies available in the study area over a period of five days, independently using the same flycatcher. Wheat flour dough was observed to be the most efficient fly attractant compared to other food sources including protein bait.

Animals↗