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Biomedical subjects

P Chaturvedi

Publications and source records attributed to P Chaturvedi.

At least 19 recordsLinked to original sources

Split therapy: planned neck dissection followed by definitive radiotherapy for a T1, T2 pharyngolaryngeal primary cancer with operable N2, N3 nodal metastases--a prospective study.

BACKGROUND: The management of patients with a small pharyngolaryngeal cancer (T1 and T2) with large nodal metastases is a subject of debate. We present data on the feasibility and outcome of treating these patients with surgery for the nodal metastases followed by definitive radiotherapy. METHODS: Prospective study of 59 patients of small pharyngolaryngeal primary squamous carcinomas with operable (N2/N3) nodal metastasis treated with neck dissection followed by radiotherapy. RESULTS: Complete nodal clearance was achieved in 54 (90%). The mean nodal size was 4 cm and extranodal extension was seen in 88% of patients in the study group. There were no significant postoperative complications. Median interval between surgery and radiotherapy was 23 days. Forty-nine patients (83%) started their RT within 6 weeks of surgery. With a median follow-up of 25 months, the disease free and overall survival was 54% and 60% (5 years). CONCLUSION: The management of patients with a radiocurable pharyngolaryngeal primary with large nodes by this approach is a feasible option with adequate control and survival.

Adult↗

Functional characterization of an orphan nuclear receptor, Rev-ErbAalpha, in chondrocytes and its potential role in osteoarthritis.

OBJECTIVE: To evaluate the expression and function of the orphan nuclear receptor Rev-ErbAalpha in articular cartilage and to investigate its role in osteoarthritis (OA). METHODS: Expression of Rev-ErbAalpha was analyzed at both the messenger RNA and protein levels in human and bovine articular cartilage and chondrocytes by real-time polymerase chain reaction (TaqMan) and immunocytochemical techniques. The effects of cartilage catabolic and anabolic agents on the expression of Rev-ErbAalpha were evaluated by TaqMan analysis. Overexpression was achieved by either adenoviral transduction or treatment with a peroxisome proliferator-activated receptor alpha agonist, whereas expression was suppressed by antisense oligonucleotides. RESULTS: Among the 48 known nuclear receptors, Rev-ErbAalpha was found to be the most highly expressed in OA cartilage. It is known to function as a transcription repressor. Treatment of articular chondrocytes with known catabolic agents resulted in the induction of Rev-ErbAalpha, whereas stimulation with anabolic agents led to a decrease in expression. Overexpression of the nuclear receptor was associated with an increase in the expression of matrix-degrading enzymes such as matrix metalloproteinase 13 and aggrecanase. In contrast, a decrease in Rev-ErbAalpha expression led to a concomitant reduction in the activity of matrix-degrading enzymes. CONCLUSION: This study is the first to demonstrate that Rev-ErbAalpha is highly expressed in OA articular chondrocytes and that its expression is modulated by known cartilage catabolic and anabolic stimuli. We also demonstrated that modulation of Rev-ErbAalpha expression in chondrocytes may be a novel means of regulating the expression and production of multiple matrix-degrading enzymes. These observations suggest that Rev-ErbAalpha may be a novel therapeutic target for OA.

ADAM Proteins↗

Bacillus aerius sp. nov., Bacillus aerophilus sp. nov., Bacillus stratosphericus sp. nov. and Bacillus altitudinis sp. nov., isolated from cryogenic tubes used for collecting air samples from high altitudes.

Four novel bacterial strains were isolated from cryogenic tubes used to collect air samples at altitudes of 24, 28 and 41 km. The four strains, 24K(T), 28K(T), 41KF2a(T) and 41KF2b(T), were identified as members of the genus Bacillus. Phylogenetic analysis based on 16S rRNA gene sequences indicated that three of the strains, 24K(T), 28K(T) and 41KF2a(T), are very similar to one another (>98 % sequence similarity) and show a similarity of 98-99 % with Bacillus licheniformis and 98 % with Bacillus sonorensis. DNA-DNA hybridization studies showed that strains 24K(T), 28K(T) and 41KF2a(T) exhibit <70 % similarity with each other and with B. licheniformis and B. sonorensis. Differences in phenotypic and chemotaxonomic characteristics between the novel strains and B. licheniformis and B. sonorensis further confirmed that these three isolates are representatives of three separate novel species. Strain 41KF2b(T) showed 100 % 16S rRNA gene sequence similarity to Bacillus pumilus, but differed from its nearest phylogenetic neighbour in a number of phenotypic and chemotaxonomic characteristics and showed only 55 % DNA-DNA relatedness. Therefore, the four isolates represent four novel species for which the names Bacillus aerius sp. nov. (type strain, 24K(T)=MTCC 7303(T)=JCM 13348(T)), Bacillus aerophilus sp. nov. (type strain, 28K(T)=MTCC 7304(T)=JCM 13347(T)), Bacillus stratosphericus sp. nov. (type strain, 41KF2a(T)=MTCC 7305(T)=JCM 13349(T)) and Bacillus altitudinis sp. nov. (type strain, 41KF2b(T)=MTCC 7306(T)=JCM 13350(T)) are proposed.

Air Microbiology↗

Candida colonization in preterm babies admitted to neonatal intensive care unit in the rural setting.

PURPOSE: Candida colonization in neonates results in significant morbidity and mortality. The purpose of this study was to determine colonization of Candida spp. in preterm babies and identify the risk factors. METHODS: Swabs from oral, rectum, groin and umblicus of 103 preterm and 100 term neonates were obtained within 24 hours of birth, day three, day five, day seven and thereafter every week till the neonate was admitted in the neonatal intensive care unit (NICU). Swabs were also collected from the mother's vagina prior to delivery. Twice every month, air of the NICU was sampled by settle plate and swabs were collected from the hands of health care workers and inanimate objects of NICU. Identification and speciation was done by standard methods. Antibiotic sensitivity was studied against amphotericin B, ketoconazole and fluconazole by disk diffusion method. RESULTS: Colonization with Candida was significantly higher in preterms. Earliest colonization was of oral mucosa and 77.1% of the preterms had colonised at various sites by the first week of life. Significant risk factors in colonized versus non-colonized preterms were male sex, longer duration of rupture of membranes (DROM), administration of steroids and antibiotics and vaginal colonization of mothers, whereas those in preterms versus terms were low birth weight and gestational age. C. albicans was the commonest species, both in the colonized preterms (45.9%) and vagina of mothers. Resistance was seen to fluconazole and ketoconazole only. No Candida spp. was isolated from health care personnel or environment. CONCLUSIONS: Colonization of preterms by Candida is a significant problem in NICU and the significant risk factors observed in colonized preterms were male sex, longer DROM, administration of steroids and antibiotics and vaginal colonization of mothers.

Adult↗

Role of Momordica charantia in maintaining the normal levels of lipids and glucose in diabetic rats fed a high-fat and low-carbohydrate diet.

This study aims to assess whether or not a methanol extract of Momordica charantia is able to normalise lipid and glucose levels in diabetic rats fed a high-fat and a low-carbohydrate diet. Different doses of the extract are administered orally for 45 days. The rats are bled at the beginning of the experiment and at 15-day intervals. Blood glucose, triglyceride, low-density lipoprotein (LDL), high-density lipoprotein (HDL) and cholesterol are estimated. Results showed that M. charantia extract normalised blood glucose level, reduced triglyceride and LDL levels and increased HDL level. The animals reverted to a diabetic state once the M. charantia extract was discontinued.

Animals↗

Pedobacter himalayensis sp. nov., from the Hamta glacier located in the Himalayan mountain ranges of India.

Strain HHS 22(T) was isolated from a glacial water sample from the snout of the Hamta glacier located in the Himalayan mountain ranges of India. Phenotypic, chemotaxonomic and phylogenetic analyses established the affiliation of the isolate to the genus Pedobacter. HHS 22(T) exhibits high 16S rRNA gene sequence similarity with Pedobacter cryoconitis (98 %). However, the level of DNA-DNA relatedness between HHS 22(T) and P. cryoconitis is only 42 %. Furthermore, HHS 22(T) differs from P. cryoconitis and the four other recognized species of Pedobacter in a number of phenotypic characteristics. These data suggest that HHS 22(T) represents a novel species of the genus Pedobacter, for which the name Pedobacter himalayensis sp. nov. is proposed. The type strain is HHS 22(T) (= JCM 12171(T) = MTCC 6384(T)).

Bacterial Typing Techniques↗

Dyadobacter hamtensis sp. nov., from Hamta glacier, located in the Himalayas, India.

Strain HHS 11(T) was isolated from a water sample collected from the snout of Hamta glacier located in the Himalayan mountain ranges of India. Phenotypic, chemotaxonomic and phylogenetic analyses established the affiliation of the isolate to the genus Dyadobacter. HHS 11(T) possessed 96 and 95% 16S rRNA gene sequence similarity with respect to Dyadobacter crusticola and Dyadobacter fermentans, respectively. Furthermore, strain HHS 11(T) differs from D. crusticola and D. fermentans in a number of phenotypic characteristics. These data suggest that strain HHS 11(T) represents a novel species of the genus Dyadobacter, for which the name Dyadobacter hamtensis sp. nov. is proposed. The type strain is HHS 11(T) (=JCM 12919(T)=MTCC 7023(T)).

Bacterial Typing Techniques↗

Simultaneous reconstruction of large skin and mucosal defect following head and neck surgery with a single skin paddle pectoralis major myocutaneous flap.

The pectoralis major myocutaneous (PMMC) flap is commonly used for head and neck reconstruction especially in impoverished nations. PMMC is a sturdy pedicled flap with relatively fewer complications, the learning curve is short and no specialized training in microvascular surgery is needed in order to use this flap. In a defect that requires a large skin and mucosal lining the authors routinely use either a bi-paddle PMMC or a combination of PMMC (for the mucosal lining) and a delto-pectoral flap (for the skin defect). It is indisputable that free tissue transfer is a better way of reconstruction for the majority of most such defects. Unfortunately, not all patients can be offered this form of reconstruction due to the cost, time, expertise and infrastructural constraints in high volume centres such as ours. Bi-paddling of PMMC is hazardous in obese males and most female patients. In such patients the skin defect is reconstructed usually by the delto-pectoral (DP) flap but this, for obvious reasons, is less welcomed by the patients. The authors suggest a technique wherein mucosal lining is created by the myofascial lining (inner surface) of the flap and the skin defect is reconstructed by the skin paddle of the single paddle PMMC. It should be considered wherever a DP flap is unacceptable, or bi-paddling or free tissue transfer is not possible.

Female↗

Effect of Momordica charantia on lipid profile and oral glucose tolerance in diabetic rats.

In this study, the methanol extract of Momordica charantia fruit extract was administered to diabetic rats to assess the long term effect of the extract on the lipid profile and the oral glucose tolerance test. Treatment for 30 days showed a significant decrease in triglyceride, low density lipoprotein and a significant increase in high density lipoprotein level. A significant effect on oral glucose tolerance was also noted. Chronic administration showed an improvement in the oral glucose tolerance curve. The effect was more pronounced when the test was done in rats fed the extract on the day of the test compared with tests done in rats which were not fed the extract on the same day.

Animals↗

Utilization of intestinal clamps for precise cutting of the pectoralis major muscle while raising a myocutaneous flap.

A variety of approaches have been employed for the reconstruction of head and neck defects and most of the techniques involve the use of arterialized vascular flaps alone, or in conjunction with other regional or local tissues. We frequently use a pectoralis major myocutaneous (PMMC) flap in our hospital in addition to other pedicled or free tissue transfers. A PMMC flap is a reliable flap with acceptable complications, needs a small learning curve, takes less time, and does not require additional investment (i.e. microscopes, loops etc). The disadvantages of the PMMC flap is that it has a restricted arc of rotation, gives a cosmetically unacceptable bulk in the neck, it is difficult in females and causes significant shoulder dysfunction. We have made a small improvization in the flap-raising technique which is helpful for the surgeon. This involves utilization of intestinal clamps to hold and cut the pectoralis major muscle.

Female↗

Regulation of type 1 diabetes by a self-MHC class II peptide: role of transforming growth factor beta (TGF-beta).

The present study was undertaken to analyze the regulatory T cells generated in response to class I derived self-I-A beta(g7) (54-76) peptide. It was observed T cells from young unprimed type 1 diabetes (T1D) prone NOD mice did not respond to self-I-A beta(g7) (54-76) peptide although T cells from primed young NOD mice showed a strong response. T cells from young unprimed BALB/c mice responded to self-I-A beta(d) (62-78) peptide. However, a breakdown of tolerance to these peptides was observed with age in both the strains. Culture supernatant from I-A beta(g7) (54-76) peptide-primed cells secreted large amounts of TGF-beta and inhibited T cell responses in allogeneic-MLR. Further, I-A beta(g7) (54-76) peptide specific T cell lines from young (I-A.Y) and diabetic (I-A.D) NOD mice were established. I-A.Y secreted IL-4, TGF-beta and IL-10 while I-A.D T cell line secreted IL-10 and IFN-gamma. We found that I-A.D T cell line induced diabetes when transferred in NOD/SCID mice but I-A.Y T cell line did not induce disease. These results show that immunization of NOD mice with I-A beta(g7) (54-76) peptide at a younger age induces a regulatory T cell response suggesting that correcting the defects in immunoregulatory mechanisms using self-MHC peptides may be one of the approaches to prevent autoimmune diseases like T1D.

Animals↗