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N Das

Publications and source records attributed to N Das.

99 records · Page 6Linked to original sources
PubMedDate not supplied

Bacopasaponin C: critical evaluation of anti-leishmanial properties in various delivery modes.

Bacopasaponin C, an indigenous glycoside, was isolated from Indian medicinal plant Bacopa monniera (b. brahmi) and was tested for antileishmanial properties both in free and in various delivery modes, e.g., niosomes, microspheres, and nanoparticles that are used now as alternatives to more commonly used liposomes. The different vesicles were prepared by published protocols. The percent intercalation of Bacopasaponin C in liposomes, niosomes, and micropspheres determined at its absorption maximal (lambda(max) = 238 nm, epsilon = 8.6 x 10(3) M(-1) x cm(-1)) was found to be 30; for nanoparticles it was 50. At equivalent dose of 1.75 mg/kg body weight, every third day for a total of 6 doses in 15 days, Bacopasaponin C in all the vesicular forms was found to be very active. An inverse linear relationship between the efficacy and the size of the vesicles was established. As analyzed from tissue histology, blood pathology, and specific tests related to normal liver and kidney functions, Bacopasaponin C in each of the four vesicular forms was found to be without any side effects. Thus, because of its indigenous origin and non-toxic nature, Bacopasaponin C could very well be considered for application in the clinic through these alternative delivery modes.

Animals↗
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Unilateral groin and pelvic irradiation for unilaterally node-positive women with vulval carcinoma.

It is essential that any patient with resected vulval cancer and significant nodal disease receive optimal adjuvant treatment with radiation. Adequate radiotherapy for such patients with unilateral positive groin nodes has not been defined. Whether both groins and pelvic sidewalls should be irradiated or only the affected (node positive) side remains unclear. From our registry, we identified all patients with primary, previously untreated squamous cell carcinoma of the vulva undergoing bilateral inguinofemoral lymphadenectomy (superficial and deep nodes) and having unilaterally positive groin nodes treated with unilateral groin and pelvic radiotherapy (44 Gy in 22 fractions). Clinical and pathologic records were reviewed to identify the anatomical site and timing of recurrences in these patients and determine whether unilateral groin and pelvic irradiation was sufficient for disease control on the node-negative side. From 1983 to 2002, 20 patients with unilateral positive nodes treated with unilateral groin and pelvic irradiation were identified. Nineteen patients were classed as having FIGO stage III disease and one as FIGO stage IV due to involvement of the rectal mucosa. There were nine patients with disease recurrences in this group (45%). The disease-free interval ranged from 4 to 31 months (median time to recurrence, 9 months). All nine patients had local or regional failures, the most common site being the ipsilateral groin (six of nine patients). One patient was also found to have distant metastases. There were no recurrences noted in the contralateral (nonirradiated) groin or pelvic sidewall. Recurrence was generally fatal. Eight of the nine patients subsequently died of their disease. The ninth patient died of another cause. There was a high incidence of regional failure after unilateral groin and pelvic radiotherapy, but there were no recurrences on the nonirradiated, node-negative side. Although a small series, we speculate that there is no apparent disadvantage to administering unilateral adjuvant radiotherapy for unilaterally positive groin nodes and encourage further studies in order to more confidently determine whether the tendency observed in our center holds true.

Adult↗
PubMedDate not supplied

Effect of oxidative stress and erythropoietin on cytoskeletal protein and lipid organization in human erythrocytes.

Phenylhydrazine (PHX)-mediated damage in human red blood cells has been assessed by monitoring the release of tyrosine from cell proteins as well as using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). PHX-treated red blood cells exhibited concentration- and time-dependent tyrosine release. ATP has no effect on the release of tyrosine. This observation is supported by SDS-PAGE pattern of RBC membrane proteins, which shows a correlation between tyrosine release and cytoskeletal protein degradation. PHX requires the presence of erythrocyte cytosolic fraction for the degradation, possibly due to the presence of a proteolytic enzyme in the cytosol. PHX treatment renders the membrane proteins susceptible to the proteolytic attack. Treatment of PHX-exposed erythrocyte with bee venom phospholipase A2 induces the translocation of phosphatidylserine (PS) and phosphatidylethanolamine (PE) to the outer surface of the cell membrane. At the same time, phosphatidylcholine (PC) was translocated towards the inner surface, altering the membrane phospholipid asymmetry. Interestingly, increased tyrosine production followed by translocation of phospholipids across the red blood cell membrane by PHX treatment is completely inhibited by 0.2 units of erythropoietin (EP). Our findings suggest that exposure of red blood cells to an oxidant like PHX causes degradation of cytoskeletal protein by an ATP-independent proteolytic pathway and this in turn allows the transbilayer movement of phospholipids across the cell membrane. EP, by scavenging the hydroxyl radicals produced during interaction of PHX with red blood cells, protects the erythrocytes from oxidative attack.

Cytoskeletal Proteins↗
PubMedDate not supplied

Plastination of whole brain specimen and brain slices.

BACKGROUND: The human dead body specimens are plastinated for teaching purposes in medical institutions, using silicone. The silicone impregnated whole brain specimens and brain slices do not give satisfactory results. METHODS: In the present study the brain specimens were plastinated with another polymer known as Polyester-Copolymer. The brain specimens were first preserved and then fixed with 5% formalin. The specimens were then dehydrated and degreased in a volatile solvent acetone. The specimens were placed in Polyester-Copolymer solution which penetrated the brain tissue both intracellulary and intercelluraly. The specimens were then cured by gas method. RESULTS: The whole brain specimens and brain slices plastinated with Polyester-Copolymer were dry, odorless, handy and durable. It also gives a clear visual contrast between grey and white matter in brain slices whereas the brain specimens plastinated with silicone are flexible and sticky. There was no color contrast between grey and white matter. CONCLUSION: The polyester impregnated brain specimens and slices are non-toxic and ideal for teaching purposes and examinations. They require minimal aftercare. The whole organ serial sections of plastinated brain specimens will help 3-dimensional study of the normal brain and will improve the assessment of brain pathology.

Brain↗
PubMedDate not supplied

Detection of liposomes in portal blood following oral administration.

125Iodine-labeled human immunoglobulin G-encapsulated dipalmitoyl phosphatidylcholine liposomes were prepared with or without asialoganglioside. Distribution of radioactivity following the oral administration of these liposomes in rats was checked in liver and in blood of the portal vein and heart. Gel filtration of plasma from the portal vein showed the presence of intact liposomes and protein. In contrast, neither liposomes nor protein were detected in cardiac blood but only lower molecular weight materials. The presence of liposomes in portal blood was further suggested from experiments using 6-carboxyfluorescein-entrapped liposomes. The level of liposomes in portal venous blood plasma was found to be lower in asialoganglioside liposomes. But this level could be increased substantially, almost to that in liposomes without asialoganglioside, by injection (iv) of asialofetuin.

Administration, Oral↗
PubMedDate not supplied

A cross-sectional study on factors including HIV testing and counselling determining unsafe injecting practices among injecting drug users of Manipur.

In India, a steep increase in the prevalence of HIV (0% to 50% within six months) among the IDUs has been reported in Manipur, a north eastern state in 1990. In spite of large scale intervention program like educational campaign and widespread voluntary HIV testing in this state, the infection has quickly spread to the heterosexual population at large. The determinants of risk taking behaviors like sharing of unclean needle among the IDU population has been explored in this paper. A cross sectional study has been carried out among all of the 488 IDUs who attended any detoxification centers and prison during last two years at Imphal, the capital city of this state. Self reported behaviors based on the pre-scheduled interview were recorded and participation rate was satisfactory. The data was compared to a similar survey carried out by us in 1990. Although there has been decline in risk behavior among the IDUs, a logistic regression analysis reveals that unsafe needle sharing behavior is not influenced by the knowledge on HIV transmission, educational status or history of HIV testing or serostatus of the individual. The limitation of cross sectional nature of the study, bias due to collection of data in prison, self reported behavior, possible differences with street samples of the addict are discussed.

AIDS Serodiagnosis↗
PubMedDate not supplied

Problem based module for the learning of biochemistry and molecular biology of hepatitis.

A problem based module for learning the concepts and practice of biochemistry and molecular biology in the understanding of hepatitis is suggested. The components of this module are (a) triggers--which represent case presentation, investigations and management strategies in the form of small statements organized in a logical sequence to provoke hypothetico-deductive reasoning and self directed identification of learning needs by the students, (b) guidelines for student tutor interaction--for conducting the learning exercise which is in the form of small group discussions facilitated by a tutor, (c) list of learning needs-essentially to be indentified in each group, (d) list of learning objectives--to ensure the necessary learning achievement, (e) few suggestions and guidelines for learning resources and (f) an overview of the problem. This module can be modified or altered for students at different phases of the medical curriculum. The suggested module can be best implemented through 3 tutorial sessions of 2 hours each, on alternate days, supported by 2-3 resource sessions (brief interactive/didactic lectures on selected difficult areas) in between. Alternate days can be organized for practical or skill sessions along with time for student's own learning and presentation in group during the tutorial session to be held on the following day.

Curriculum↗
PubMedDate not supplied

Relationship of national highway with injecting drug abuse and HIV in rural Manipur, India.

Earlier study reported that about 1% of general population or urban Manipur was injecting drug users (IDUs). A study was conducted to observe the IDU prevalence in rural Manipur and the role of national highway (NH) in determining the IDU prevalence if any. It was also aimed to study the HIV prevalence among IDUs of different villages. Villages were startified in to 3 categories based on distance and communication facilities from the national highway, which cuts across the villages to the neighboring state, Nagaland. Villages close to NH had the highest IDU prevalence of 1.3% and remote villages had the least prevalence of 0.2% whereas villages in between the above mentioned two groups had a prevalence of 0.9%. It was surprisingly observed that HIV was uniformly distributed among the IDUs of all villages and ranged from 50-51%. This indicates that IDU prevalence at distance is predominantly determined by the presence of drug trafficking route/s like national highway whereas HIV prevalence is mainly determined by the needle sharing behaviour of IDUs.

Adolescent↗