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Biomedical subjects

Pankaj Chaturvedi

Publications and source records attributed to Pankaj Chaturvedi.

18 recordsLinked to original sources

Acidic transcription factors position the genome at nuclear speckles through transcription-dependent and -independent mechanisms.

A small fraction of the genome reproducibly positions near nuclear speckles (NSs), increasing the expression and/or splicing efficiency of NS-associated genes. How specific genomic regions in mammalian cells are targeted to NSs remains unclear. Here, we demonstrate the establishment of genome-wide NS association without active transcription. We show that DNA sequences derived from NS-associated regions, when integrated as transgenes, are autonomously targeted to NSs. By systematically dissecting one such genomic locus, the COL1A1-SGCA locus, we identified redundant NS-targeting cis-regulatory elements, including an ∼600-bp fragment with 17 binding motifs for 8 transcription factors (TFs). Four NS-targeting TFs within this fragment contain acidic activation domains (AADs) that provide both chromatin-context and transcription-dependent NS targeting, properties that appear to be common among several other tested AADs. A subset of acidic activator TFs contains an additional, transcription-independent NS-targeting activity. Our findings establish diverse and partially redundant NS-targeting activities, which may facilitate dynamic gene positioning at the NS periphery for context-specific transcriptional responses.

Transcription, Genetic↗

Association of alcohol and different types of alcoholic beverages on the risk of buccal mucosa cancer in Indian men: a multicentre case-control study.

INTRODUCTION: While a large proportion of buccal mucosa cancer (BMC) is attributed to tobacco use, the contribution of alcohol is little-known. In India, alcohols include internationally-recognised (IRL) and locally-brewed liquor (LBL) types, which might contribute differently to the risk of BMC. We conducted an observational study to evaluate the association of local and foreign alcoholic beverage use on the risk of developing BMC. METHODS: Data from 1803 BMC cases and 1903 visitor controls from a multicentric case-control study was analysed for 11 IRLs and 30 LBLs. Healthy visitor controls were randomly sampled from the source population of the study centres which enrolled the cases. Quantitative data on the amount, the number of times consumed per day or week, and the lifetime duration of consumption for each of the alcoholic beverages were collected using an interviewer administered standardised questionnaire, which was then used to estimate the grams per day consumption of alcohol. Odds ratios (OR) and 95% CI were estimated after adjustment for potential confounders, including tobacco use. The joint effect of tobacco and alcohol on BMC risk, the attributable fraction (AF) of cases and state-wise population attributable fraction (PAF) were estimated. RESULTS: An increased risk of 1.68 (95% CI=1.44-1.97), 1.72 (95% CI=1.46-2.04), and 1.87 (95% CI=1.46-2.39) was observed for ever-users of any alcohol, IRLs and LBLs, respectively for BMC. The findings show 9 grams/day of alcohol increased the risk of BMC by approximately 50%, and 62% of cases could be attributed to alcohol drinking and chewing tobacco, with an overall PAF of 11.3% for India. CONCLUSION: This study shows that alcohol, even in low quantities, increases the risk for BMC. Prevention of consumption of tobacco and alcohol together could substantially reduce the incidence of BMC.

Humans↗

Buccal plate excision for buccal paramandibular spread.

Cancer of buccal gingival sulcus lie in close proximity to mandible but tend to invade bone late in the course of disease. Segmental mandibulectomy advocated for these tumors results in cosmetic disfigurement and functional impairment. We, for the first time, describe a mandibular preservation alternative, in form of buccal cortical plate excision, for these tumors.

Cheek↗

Selective neck dissection (I-III) for node negative and node positive necks.

Selective neck dissection (I-III) for oral cancers offers similar regional control rates with less morbidity as compared with modified radical neck dissection. Charts of 414 patients with oral cancer, who underwent selective neck dissection (I-III) during 1994-2001, were analysed retrospectively. Seventy nine percent of the patients had a primary tumour in the gingivo-buccal complex. Cancer of tongue showed a trend towards higher regional failure (12.3%) as compared to gingivo-buccal cancers (6.5%). Primary tumour was staged as T1-8%, T2-47%, T3-19% and T4-26%. Sixty five percent of the patients were clinically node negative. Isolated neck failure was observed in 4.8% of patients at 2 years and in 5.8% at 5 years. De-differentiation of primary tumour and perineural spread were associated with regional failures. Eighty three percent of the neck recurrences were in the ipsilateral neck and only 16% of these were at levels IV or V. In all, 30% of all regional failures were outside the field of dissection.

Adult↗

The role of nutrition in oncology: a need for a change of attitude and curriculum.

BACKGROUND: The role of nutrition in cancer is poorly understood by Indian oncologists, who are exposed to minimal education on nutrition in their undergraduate and postgraduate careers. METHODS: A postal questionnaire survey, without reminder, assessed the knowledge and beliefs about nutrition of 120 oncologists in India (response rate = 58%). RESULTS: There was a lack of teaching and understanding by surgeons and radiation and medical oncologists about the role of nutrition in prevention, carcinogenesis, treatment, and outcome. CONCLUSIONS: There needs to be much more emphasis in undergraduate and postgraduate education about the supportive role of nutrition in cancer.

Clinical Competence↗

Advanced squamous cell carcinoma of lower gingivobuccal complex: patterns of spread and failure.

BACKGROUND: Carcinoma of the gingivobuccal complex is commonly associated with the use of smokeless tobacco known as "quid." METHODS: We conducted a retrospective chart review of 511 patients with advanced cancer of gingivobuccal complex surgically treated during 1994 to 1995. We evaluated patterns of disease failure in these patients and correlated disease-free survival with various prognostic factors. RESULTS: During a median follow-up of 46 months, 159 locoregional recurrences and 11 distant metastases were detected in 148 patients. Seventy-nine percent of the recurrences appeared within 18 months of surgery, and the median survival for patients with recurrent disease was less than 4 months. Two-year and 5-year disease-free survival rates were 64% and 57%, respectively. On multivariate analysis, disease-free survival showed significant correlation with skin involvement and extracapsular spread. CONCLUSIONS: Gingivobuccal cancers usually fail locoregionally. Soft tissue infiltration and extracapsular spread of nodal disease influence disease-free survival.

Adult↗

A novel technique of raising a pectoralis major myocutaneous flap through the skin paddle incision alone.

A good reconstruction should not only be functionally and aesthetically sound at the recipient site but also cause least possible cosmetic aberration of the donor site. The pectoralis major myocutaneous (PMMC) flap continues to be one of the most commonly used flap for head and neck reconstruction in this part of the world. Conventionally, once the skin paddle over the pectoralis major muscle is marked, a line is drawn joining the outer edge of the skin flap extending to the apex of the anterior axillary skin fold or midclavicular point to expose the underlying pectoralis major muscle and harvest the flap. We intend to suggest a novel technique, in which the pectoralis major muscle is exposed by raising the skin around the skin paddle incision alone without making any further extension.

Dermatologic Surgical Procedures↗

Reconstruction of early lower gingivo buccal complex lesions using floor of mouth advancement augmented with hyoglossus release.

The surgical treatment in early cancers of the lower gingivobuccal (GB) complex involves wide resection of the buccal mucosa and GB sulcus with or without marginal mandibulectomy. To reconstruct this defect we endeavour to describe a method of advancement of the lateral floor of mouth and tongue to provide pliable, vascularised tissue to bridge the mucosal defect and achieve tension free, primary closure whilst preserving maximum tongue mobility and maintaining adequate mouth opening, thus offering an elegant and simple solution to the problems of reconstruction in early lesions of the lower gingivo buccal complex.

Cheek↗