Defence Research Laboratory Tezpur

Assam, India

Defence Research Laboratory Tezpur

Assam, India
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Mazumder A.H.,Defence Research Laboratory Tezpur | Das J.,Defence Research Laboratory Tezpur | Kumar Gogoi H.,Defence Research Laboratory Tezpur | Chattopadhyay P.,Defence Research Laboratory Tezpur | And 2 more authors.
Pharmacognosy Journal | Year: 2012

Introduction: The current research has focused on the potentiality of medicinal plants for treatment of Candida albicans infections. Five plants viz. Clerodendron colebrookianum Walp. (Leaf), Gnetum gnemon L. (Leaf), Sarcochlamys pulcherrima (Roxb.) Gaud. (Leaf), Garcinia lancifolia (Don) Roxb (Leaf) and Euryale ferox Salisb. (Seed), used as traditional medicines in Cachar district, Assam, India were selected to evaluate in vitro activity against C. albicans. Methods: The plant samples were extracted with methanol. Agar well diffusion assay was used to test the activity of the plant extracts and broth microdilution method was used to determine the MIC. Results: All extracts showed anticandidial activity with zones of inhibition ranging from 17 to 25 mm at 2×105 μg/ml extract. E. ferox and S. pulcherrima showed the highest activity with the MIC value of 1.25 × 104 μgg/ml. The remaining extracts were comparatively less effective showing MIC value of 2.5 × 104 μg/ml. Conclusions: Anticandidial activity of the plants extracts, observed in this study highlighted further in vivo investigation and identification of the active compounds for therapeutic uses. The anticandidial activity of S. pulcherrima and G. lancifolia is probably the first report to the best of our knowledge. © 2012 Pharmacognosy Network Worldwide [Phcog.Net].


Yadav K.,Defence Research Laboratory Tezpur | Dhiman S.,Defence Research Laboratory Tezpur | Rabha B.,Defence Research Laboratory Tezpur | Goswami D.,Defence Research Laboratory Tezpur | And 2 more authors.
Journal of Arthropod-Borne Diseases | Year: 2017

Background: Orang Primary Health Centre (OPHC) and Balipara Primary Health Centre (BPHC) of Assam (India) report mosquito borne diseases annually. Current study was performed to ascertain the prevalence of known malaria and Japanese Encephalitis (JE) vectors and their possible role in disease transmission. Methods: Malaria epidemiological data for 2006-2010 and JE data for 2008-2013 of Assam, India were obtained from the health authority. Mosquitoes were collected using CDC light traps and identified morpho-taxonomically. Results: Plasmodium falciparum cases (81.5%, 95% CI= 72.0-91.1) were statistically higher in OPHC (P < 0.0001, t= 8.0) during the recent years. There was 4.4 folds rise in the confirmed acute encephalitis syndrome (AES) and 3.2 folds increase in the confirmed JE cases during 2013 as compared to 2008. Altogether 9,218 mosquito specimens (PTND= 153.6), comprising of 44.1% anophelines (PTND= 67.7), 42.3% culicines (PTND= 65.0) and 9.5% mansonia (PTND= 14.6) were recorded. In BPHC, An. vagus was recorded in high density (P < 0.0001), whereas Cx. quinquefasciatus was the predominant JE vector (P= 0.04). In OPHC, among the known malaria vectors, the density of An. annularis was significantly high (P < 0.0001). However Culex bitaeniorhynchus was the predominant known JE vector (P < 0.0001) followed by Cx. quinquefasciatus. Conclusion: Even in the absence of known efficient vectors, many Anopheles species are still involved in malaria transmission. There was disappearance of An. minimus and An. dirus and establishment of An. annularis, An. vagus and An. philippinensis/nivipes mosquitoes in study area.


Datta S.,Defence Research Laboratory Tezpur | Chatterjee S.,Defence Research Laboratory Tezpur | Veer V.,Defence Research Laboratory Tezpur | Chakravarty R.,ICMR Virus Unit
Journal of Clinical and Experimental Hepatology | Year: 2012

Hepatitis B virus (HBV) infection is one of the major global health problems, especially in economically under-developed or developing countries. HBV infection can lead to a number of clinical outcomes including chronic infection, cirrhosis and liver cancer. It ranks among the top 10 causes of death, being responsible for around 1 million deaths every year. Despite the availability of a highly efficient vaccine and potent antiviral agents, HBV infection still remains a significant clinical problem, particularly in those high endemicity areas where vaccination of large populations has not been possible due to economic reasons. Although HBV is among the smallest viruses in terms of virion and genome size, it has numerous unique features that make it completely distinct from other DNA viruses. It has a partially double stranded DNA with highly complex genome organization, life cycle and natural history. Remarkably distinct from other DNA viruses, it uses an RNA intermediate called pregenomic RNA (pgRNA) and reverse transcriptase for its genome replication. Genome replication is accomplished by a complex mechanism of primer shifting facilitated by direct repeat sequences encoded in the genome. Further, the genome has evolved in such a manner that every single nucleotide of the genome is used for either coding viral proteins or used as regulatory regions or both. Moreover, it utilizes internal in-frame translation initiation codons, as well as different reading frames from the same RNA to generate different proteins with diverse functions. HBV also shows considerable genetic variability which has been related with clinical outcomes, replication potential, therapeutic response etc. This review aims at reviewing fundamental events of the viral life cycle including viral replication, transcription and translation, from the molecular standpoint, as well as, highlights the clinical relevance of genetic variability of HBV. © 2012 INASL.


PubMed | Defence Research Laboratory Tezpur and ICMR Virus Unit
Type: Journal Article | Journal: Journal of clinical and experimental hepatology | Year: 2015

Hepatitis B virus (HBV) infection is one of the major global health problems, especially in economically under-developed or developing countries. HBV infection can lead to a number of clinical outcomes including chronic infection, cirrhosis and liver cancer. It ranks among the top 10 causes of death, being responsible for around 1million deaths every year. Despite the availability of a highly efficient vaccine and potent antiviral agents, HBV infection still remains a significant clinical problem, particularly in those high endemicity areas where vaccination of large populations has not been possible due to economic reasons. Although HBV is among the smallest viruses in terms of virion and genome size, it has numerous unique features that make it completely distinct from other DNA viruses. It has a partially double stranded DNA with highly complex genome organization, life cycle and natural history. Remarkably distinct from other DNA viruses, it uses an RNA intermediate called pregenomic RNA (pgRNA) and reverse transcriptase for its genome replication. Genome replication is accomplished by a complex mechanism of primer shifting facilitated by direct repeat sequences encoded in the genome. Further, the genome has evolved in such a manner that every single nucleotide of the genome is used for either coding viral proteins or used as regulatory regions or both. Moreover, it utilizes internal in-frame translation initiation codons, as well as different reading frames from the same RNA to generate different proteins with diverse functions. HBV also shows considerable genetic variability which has been related with clinical outcomes, replication potential, therapeutic response etc. This review aims at reviewing fundamental events of the viral life cycle including viral replication, transcription and translation, from the molecular standpoint, as well as, highlights the clinical relevance of genetic variability of HBV.


Dhiman S.,Defence Research Laboratory Tezpur | Rabha B.,Defence Research Laboratory Tezpur | Chattopadhyay P.,Defence Research Laboratory Tezpur | Das N.G.,Defence Research Laboratory Tezpur | And 4 more authors.
Tropical Biomedicine | Year: 2012

In the present study we have evaluated the repellent activity of mixture of Curcuma longa, Zanthoxylum limonella and Pogostemon heyneanus essential oils in 1:1:2 ratio at 5%, 10% and 20% concentration against blackflies in northeastern India. Initially the essential oil mixture tested here has been found effective against Aedes albopictus mosquitoes. The average protection recorded in 20% concentration (170.56±4.0; 95% CI = 162.09-179.02) was higher as compared to other two concentrations (F = 90.2; p<0.0001; df = 53). Percentage repellency and repellency index was found to be higher in 20% concentration (p≤0.017). No appreciable clinical and behavioral signs were observed in the acute dermal toxicity using rat model. No changes were observed in biochemical profiles of treatment group animals. Similarly, no prominent lesions were observed in vital organs of treatment in both the sexes. The study concludes that tested repellent is safe for use and has multi-insects repellent property.


PubMed | Defence Research Laboratory Tezpur
Type: Journal Article | Journal: Tropical biomedicine | Year: 2012

In the present study we have evaluated the repellent activity of mixture of Curcuma longa, Zanthoxylum limonella and Pogostemon heyneanus essential oils in 1:1:2 ratio at 5%, 10% and 20% concentration against blackflies in northeastern India. Initially the essential oil mixture tested here has been found effective against Aedes albopictus mosquitoes. The average protection recorded in 20% concentration (170.56 4.0; 95% CI = 162.09-179.02) was higher as compared to other two concentrations (F = 90.2; p<0.0001; df = 53). Percentage repellency and repellency index was found to be higher in 20% concentration (p 0.017). No appreciable clinical and behavioral signs were observed in the acute dermal toxicity using rat model. No changes were observed in biochemical profiles of treatment group animals. Similarly, no prominent lesions were observed in vital organs of treatment in both the sexes. The study concludes that tested repellent is safe for use and has multi-insects repellent property.

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