Biomedical subjects

Debabrata Basu

Publications and source records attributed to Debabrata Basu.

3 recordsLinked to original sources

PubMed2026

Functional analysis of the role of a wound-induced leucine aminopeptidase gene homologue isolated from Rorippa indica in aphid herbivory.

Leucine aminopeptidases (LAPs) are multifunctional enzymes with roles in both defence and development. In plants, they are reported to be induced by wound-inflicting Lepidopteran insects and regulate wound response pathways leading to an effective defence response. Infestation by Hemipteran mustard aphid, Lipaphis erysimi (L.) Kaltenbach has been reported to induce wound response as well as a wound-responsive Arabidopsis thaliana Lap1 homologue (RI01; GenBank Accession: JK034053) in Rorippa indica (L.) Hiern. This is interesting as Hemipteran insects like aphids are assumed to inflict minimal wounding. In the present study, starting with the RI01 sequence information, we isolated the full length (1566 bp) sequence of a novel R. indica Lap (RiLap) gene, performed in silico analyses and developed transgenic R. indica plants with suppressed RiLAP activity by expressing a 565 bp antisense fragment of RiLap cDNA. We found that the isolated RiLAP is an acidic LAP of M17 family and suppressing it causes a significant increase in aphid herbivory but reduction in total chlorophyll content and possibly photosynthetic capacity in aphid infested transgenic plants of the T1 generation. These findings though preliminary suggest that RiLap could have a role in deterring aphids by acting as a regulatory protein simultaneously balancing defence response and photosynthetic capacity or plant growth. Noting the dearth of research in this area, this pilot study will be useful for designing future in depth analyses in understanding the role of Laps in defence response against Hemipteran insects. The study has implications in the development of sustainable pest management avenues.

Leucyl Aminopeptidase↗

PubMed2005

Synthetic hydroxyapatite-based integrated orbital implants: a human pilot trial.

PURPOSE: Orbital implants are used as fillers following enucleation or evisceration surgeries to replace the lost volume for better cosmesis and motility of the artificial eye. Over the last decade porous hydroxyapatite (HAp) implants derived from the naturally occurring corals, are increasingly used. Recently synthetic HAp-based implants have been introduced. After fibrovasculrisation they have the added advantage of being directly integrated with the artificial shell, thereby increasing the motility to a great extent. The current study, evaluated the efficacy of two different models of synthetic HAp with 75% porosity and pore sizes ranging from 100 to 300 mm. METHODS: Synthetic HAp powders were prepared with a novel wet chemical route. Two models of porous orbital implants with the characteristic designs for both evisceration and enucleation surgery were developed, characterised and implanted to consecutive 25 human subjects, 17 following evisceration, and 8 following enucleation. The postoperative performances of these implants were evaluated in respect to the degree of volume replacement (implant + prosthesis), presence/absence of lagophthalmos and lower eye-lid laxity, status of socket and fornices. Magnetic resonance imaging assessed the stability of the implants within the socket and progressive fibro-vascularisation within the porous scaffold as a function of time. Finally, motility of the implants as well as the prostheses (horizontal movements by Lister Perimeter) and subjective cosmetic results (qualitative) were also evaluated. RESULTS: During the 2.5 years of follow-up study, no significant postoperative complications were noticed. One case, showed an anterior implant exposure of 3-4 mm, and was managed with donor scleral patch graft and one case of conjunctival thinning was corrected by re-suturing the conjunctival dehiscence. Fourteen of the 25 patients had a very good movement of the prostheses (> 20 degrees horizontal movement) and the other 11 patients had a fair motility (10 - 20 degrees). The degree of volume replacement (with prosthesis) was found to be very good in 21 patients and fair in other 4 patients. All patients reported cosmetic satisfaction. CONCLUSION: Synthetic HAp-based integrated orbital implants with this modified design were found clinically safe and cosmetically acceptable.

Durapatite↗

PubMed2004

The mannitol cycle in Pleurotus ostreatus (Florida).

In mushroom, presence of the mannitol cycle has not been reported so far although the polyol is supposed to be generated by the reduction of fructose by mannitol dehydrogenase. This study submits evidence for the presence of the mannitol cycle in Pleurotus ostreatus. The key enzyme of the cycle, mannitol-1-phosphate dehydrogenase (M1PDH), was present appreciably in all the developmental stages of the mushroom. However, the enzyme level dropped significantly at the onset of sporulation. The presence of M1DPH was confirmed by isozyme analysis and RT-PCR mediated amplification of a approximately 400 bp DNA fragment.

Electrophoresis, Polyacrylamide Gel↗