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Biomedical subjects

R Deshpande

Publications and source records attributed to R Deshpande.

At least 19 recordsLinked to original sources
PubMed2006

Evaluation of a pyroelectric detector with a carbon multiwalled nanotube black coating in the infrared.

The performance of a pyroelectric detector with a carbon multiwalled nanotube coating was evaluated in the 0.9-14 microm wavelength range. The relative spectral responsivity of this detector was shown to be flat over most of the wavelength range examined, and the spectral flatness was shown to be comparable to the best infrared black coatings currently available. This finding is promising because black coatings with spectrally flat absorbance profiles are usually associated with the highest absorbance values. The performance of the detector (in terms of noise equivalent power and specific detectivity) was limited by the very thick (250 microm thick) LiNbO3 pyroelectric crystal onto which the coating was deposited. The responsivity of this detector was shown to be linear in the 0.06-2.8 mW radiant power range, and its spatial uniformity was comparable to that of other pyroelectric detectors that use different types of black coating. The carbon nanotube coatings were reported to be much more durable than other infrared black coatings, such as metal blacks, that are commonly used to coat thermal detectors in the infrared. This, in combination with their excellent spectral flatness, suggests that carbon nanotube coatings appear extremely promising for thermal detection applications in the infrared.

Journal Article↗
PubMed2004

The impact of cyclosporine on the development of immunosuppressive therapy: perspective from a transplant nephrologist involved with the development of C2.

The availability of Neoral in place of Sandimmun offered better pharmacokinetics and improved results but emphasized the poor accuracy of trough levels as a tool for monitoring drug exposure and dosage adjustment. Subsequent studies confirmed that Neoral exposure correlated with clinical events and it was found that C2 was the single point that correlated best with exposure as determined by AUC(0-4h). Single and multicenter studies have now shown that C2 monitoring is practically feasible and that its use resulted in very low rates of acute rejection with excellent renal function. One retrospective comparison suggested that rates of acute rejection were lower with C2 than with C0 monitoring. This tool has now been shown to be effective in managing African-American renal transplants and those with delayed graft function. A very recent international randomized trial has shown equivalent rates of acute rejection in liver transplant recipients treated with both Neoral and Prograf. Studies now in progress will permit further refinement of target levels with the potential to improve long-term results.

Area Under Curve↗
PubMed2003

Complete thoracic ectopia cordis.

Thoracic ectopia cordis is a rare congenital defect with very few reported survivors after surgical correction. We report a case of complete thoracic ectopia cordis with double outlet right ventricle. The diagnosis was established antenatally and a repair was undertaken soon after birth. The child remained stable and was extubated on the fifth post-operative day. Forty-eight hours later the child succumbed to an unexplained respiratory arrest. Also presented is a review of the different surgical strategies for this unusual condition.

Cardiac Surgical Procedures↗
PubMed2003

Extracapsular cataract surgery compared with manual small incision cataract surgery in community eye care setting in western India: a randomised controlled trial.

AIM: To study "manual small incision cataract surgery (MSICS)" for the rehabilitation of cataract visually impaired and blind patients in community based, high volume, eye hospital setting; to compare the safety and effectiveness of MSICS with conventional extracapsular cataract surgery (ECCE). METHODS: In a single masked randomised controlled clinical trial, 741 patients, aged 40-90 years, with operable cataract were randomly assigned to receive either MSICS or ECCE and operated upon by one of eight participating surgeons. Intraoperative and postoperative complications were graded and scored according to the Oxford Cataract Treatment and Evaluation Team recommendations. The patients were followed up at 1 week, 6 weeks, and 1 year after surgery and their visual acuity recorded. RESULTS: This paper reports outcomes at 1 and 6 weeks. 706 of the 741(95.3%) patients completed the 6 week follow up. 135 of 362 (37.3%) of ECCE group and 165 of 344 (47.9%) of MSICS group had uncorrected visual acuity of 6/18 or better after 6 weeks of follow up. 314 of 362 (86.7%) of ECCE group and 309 of 344 (89.8%) of MSICS group had corrected postoperative vision of 6/18 or better. Four of 362 (1.1%) of ECCE group and six of 344 (1.7%) of MSICS group had corrected postoperative visual acuity less than 6/60. There were no significant differences between the two groups for intraoperative and severe postoperative complications. CONCLUSION: MSICS and ECCE are both safe and effective techniques for treatment of cataract patients in community eye care settings. MSICS needs similar equipment to ECCE, but gives better uncorrected vision.

Adult↗
PubMed2001

Prevalence of missed opportunities for measles immunization in rural areas of Gujarat.

To assess the prevalence of missed opportunities for measles immunization, reason for their occurrence and potential aspect of avoiding them on measles immunization coverage a cross sectional study in 40 clusters of 4 villages, Ardi, Valasan, Chikhodra and Bamroli having a population of twenty four thousand was carried out. A total of 300 children between the age group 9-24 months were included in the study. Immunization status of each child was recorded either from immunization card or maternal recall. Coverage for measles vaccine was 78.66%. Prevalence of missed opportunity was 15.33%. It was found that significant increase in measles coverage can be achieved upto 94% if all missed opportunities for measles vaccine are avoided.

Cluster Analysis↗
PubMed2000

Late esophageal toxicity using a combination of external beam radiation, intraluminal brachytherapy and 5-fluorouracil infusion in carcinoma of the esophagus.

One hundred patients with potentially curable squamous cell carcinoma of the esophagus were treated using a combination of external beam radiation, medium-dose intraluminal brachytherapy (ILBT), and 5-fluorouracil infusion (as a radiosensitizer) from January 1990 to December 1993. The main objective was to determine late toxicity and optimization of the dose of intraluminal radiation. All patients had external radiation of 50 Gy over 5 1/2 weeks, followed by ILBT of 20 Gy for 50 patients (group 1) and 15 Gy for a subsequent 50 patients (group 2), using a dose rate of 315-330 cGy/h with the prescription at 1 cm off axis. The 5-fluorouracil infusion was 500 mg/m2 administered 12 h prior to ILBT. The treatment-related complications among groups 1 and 2 were strictures 24% vs. 8% (p = 0.029), ulceration 30% vs. 28% (p = 0.8), and tracheoesophageal fistulae 12% for both groups. The overall survival for groups 1 and 2 was 8% and 23% at 5 years. The development of life-threatening complications is a major concern and extreme caution is urged before selecting patients for a combination of ILBT and 5-fluorouracil treatment.

Brachytherapy↗
PubMed2000

Biochemical characterization of S100A2 in human keratinocytes: subcellular localization, dimerization, and oxidative cross-linking.

S100A2 is a calmodulin-like protein of unknown function, whose transcription is positively regulated in response to ErbB and p53 signaling. Expression of S100A2 is markedly increased in the context of ErbB-driven reactive epidermal hyperplasia, and decreased in the context of hypofunctional p53 mutations in carcinoma cell lines and tumors. This bimodal pattern of regulation suggests an important function for S100A2 in keratinocyte differentiation and carcinogenesis. Taking the biochemical approach to the determination of S100A2 function, we have characterized its physical state and subcellular localization in normal human keratinocytes. S100A2 in hypotonic lysates remained soluble after centrifugation at 100 000 x g, indicating that it is not associated with cell membranes. Permeabilization experiments confirmed the lack of membrane association and revealed a digitonin-insoluble nuclear fraction of S100A2, which was confirmed by immunofluorescence microscopy. Pulldown assays of epitope-tagged S100A2 and yeast two-hybrid screening revealed that S100A2 displays a strong propensity to homodimerize. Naturally expressed S100A2 dimers in normal human keratinocytes readily underwent intermolecular disulfide cross-linking unless a strong denaturant was present during cell lysis. Treatment of intact normal human keratinocytes with hydrogen peroxide strongly promoted S100A2 cross-linking. These results demonstrate that native S100A2 is a homodimer that does not depend on disulfide cross-linking for stability, but undergoes intermolecular cross-linking at cysteine residues in response to oxidative stress. Based on these findings, we propose that S100A2 may protect normal keratinocytes against carcinogens by participating in the cellular proof-reading response to oxidative stress.

Antibodies, Monoclonal↗
PubMed1998

Amyloid precursor protein processing in sterol regulatory element-binding protein site 2 protease-deficient Chinese hamster ovary cells.

Amyloid peptides of 39-43 amino acids (Abeta) are the major constituents of amyloid plaques present in the brains of Alzheimer's (AD) patients. Proteolytic processing of the amyloid precursor protein (APP) by the yet unidentified beta- and gamma-secretases leads to the generation of the amyloidogenic Abeta peptides. Recent data suggest that all of the known mutations leading to early onset familial AD alter the processing of APP such that increased amounts of the 42-amino acid form of Abeta are generated by a gamma-secretase activity. Identification of the beta- and/or gamma-secretases is a major goal of current AD research, as they are prime targets for therapeutic intervention in AD. It has been suggested that the sterol regulatory element-binding protein site 2 protease (S2P) may be identical to the long sought gamma-secretase. We have directly tested this hypothesis using over-expression of the S2P cDNA in cells expressing APP and by characterizing APP processing in mutant Chinese hamster ovary cells that are deficient in S2P activity and expression. The data demonstrate that S2P does not play an essential role in the generation or secretion of Abeta peptides from cells, thus it is unlikely to be a gamma-secretase.

Amyloid Precursor Protein Secretases↗
PubMed1998

Preliminary studies on the amoebicidal efficacy of contact lens disinfection systems.

PURPOSE: This preliminary study evaluated the efficacy of contact lens disinfection systems against Acanthamoeba castellanii, tested with and without co-incubation with Pseudomonas aeruginosa. METHODS: First, disinfection systems containing 3% hydrogen peroxide, 0.00005% polyaminopropyl biguanide or 0.001% polyquaternium were challenged with A. castellanii for 72 h. Surviving cells were enumerated. Second, A. castellanii were co-incubated with P. aeruginosa for 48 h, then exposed to the disinfectants for 6 h. RESULTS: There was zero survival of A. castellanii in hydrogen peroxide and variable survival in multipurpose systems. Following co-incubation, A. castellanii survival increased significantly (P = 0.015). CONCLUSIONS: Multipurpose systems have variable anti-amoeba activity and storage cases contaminated by bacteria may enhance amoeba survival.

Acanthamoeba↗
PubMed1997

The defective antigen-presenting activity of murine fetal macrophage cell lines.

We have previously reported that placental macrophages of fetal origin have a decreased ability to present antigen. To clarify the underlying mechanism for this deficiency, we have generated primary fetal macrophage cell lines. Our data show that despite their defective antigen-presenting ability, fetal macrophages do express all known accessory molecules, intracellular adhesion molecule-1, B7 and major histocompatibility complex class II molecules. However, fetal macrophages do not express detectable invariant chain mRNA which is known to have a major role in the class II-associated antigen-processing pathway. Since fetal macrophages can neither present antigenic peptides nor superantigen, the diminished invariant chain expression alone cannot account for the impaired antigen-presenting function of fetal macrophages.

Animals↗
PubMed1997

Estradiol down-regulates LPS-induced cytokine production and NFkB activation in murine macrophages.

PROBLEM: In vivo and in vitro studies have indicated that estradiol can affect cytokine production in different cell types. This study examines whether estradiol affects inflammatory cytokine production by murine splenic macrophages. METHODS: Mouse splenic macrophages were first treated with 17 beta-estradiol, followed by lipopolysaccharide (LPS) stimulation. The production of cytokines by macrophages with or without estradiol treatment was determined at both the protein and mRNA levels. The nuclear factor-kB (NFkB) activity of activated mouse splenic macrophages was also evaluated by electrophoretic mobility shift assay. RESULT: Our results show that 17 beta-estradiol decreases LPS-induced IL-1 alpha, IL-6, and TNF-alpha production but not IL-10, IL-12, and macrophage inflammatory protein (MIP) production by splenic macrophages. Furthermore, inhibition of cytokine production by 17 beta-estradiol was associated with a decreased LPS-induced NFkB-binding activity. CONCLUSION: Because cytokines are important mediators of immune function, the alteration of cytokine production by 17 beta-estradiol may thus have a profound effect on the outcome of immune response during inflammation.

Animals↗
PubMed1996

Primary carcinoid tumor of the liver: report of four resected cases including one with gastrin production.

Four cases of primary hepatic carcinoid were identified during a retrospective study of liver resections for primary tumor. The cases included two adult males, one adult female, and a 9-year-old boy in whom gastrin levels were documented. The estimation of gastrin levels was prompted by symptoms suggestive of acid-peptic disease. One patient died postoperatively. The other three are alive and well at 3 years, 2 years, and at 1 year, respectively, after surgery, outcomes distinctly different from hepatocellular carcinomas. Diagnostic difficulties may be experienced in histologic assessment, and this may require recourse to immunohistochemistry and electron microscopy. Long-term follow-up and careful exclusion of a possible primary elsewhere are necessary for establishing the primary nature of liver carcinoids.

Adult↗
PubMed1994

Experience in screening for cervical cancer in rural areas of Barsi Tehsil (Maharashtra).

The organization of cancer detection camps is gaining popularity in our country and it is therefore necessary to evaluate the effectiveness of this approach in the early diagnosis and treatment of cancer. This to our knowledge has not been done. This report analyses an experience in screening for cervical cancer in rural areas of Barsi Tehsil (Maharashtra). The Barsi Tehsil consists of 134 villages with a population of 34,080 women above the age of 30 years (1982-1987). Of these 2,846 were screened through a series of cancer detection camps between 1982 and 1987. The results of the cytological screening in these women have been presented. An evaluation of the camp approach was carried out by the Population based Cancer Registry set up under the National Cancer Registry Programme (Indian Council of Medical Research) in Barsi, Paranda and Bhum tehsils. It was shown that acceptance of cytological screening was poor, thereby indicating that the mere holding of camps was not in itself sufficient to motivate the people, to subject themselves to the Pap smear. Certain suggestions which would appreciably increase the acceptance of cytological screening have been put forward.

Adult↗