Pavani Sowjanya - Academia.edu (original) (raw)

Papers by Pavani Sowjanya

Research paper thumbnail of DNA Methylation Profile at the DNMT3L Promoter

Research paper thumbnail of Shedding of Epstein-Barr Virus and Cytomegalovirus from the Genital Tract of Women in a Periurban Community in Andhra Pradesh, India

Journal of Clinical Microbiology, Jul 1, 2011

We found a large number of false-positive readings by visual inspection with acetic acid (VIA) in... more We found a large number of false-positive readings by visual inspection with acetic acid (VIA) in a study of cervical cancer screening strategies (VIA, human papillomavirus HPV DNA testing, and Pap cytology) in a periurban community in Andhra Pradesh, India. We evaluated whether these false-positive readings might be occurring as a result of infections with Epstein-Barr virus (EBV) or cytomegalovirus (CMV), prevalent latent herpesviruses known to be shed from the female genital tract. While we found that there was no association between VIA results and the presence of EBV or CMV in the cervix, we did find a high prevalence of both viruses: 20% for EBV and 26% for CMV. In multivariate analyses, CMV prevalence was associated with younger age, lack of running water in the home, and visually apparent cervical inflammation. EBV prevalence was associated with older age and a diagnosis of cervical intraepithelial neoplasia grade 1 or greater. The biological and clinical implications of these viruses at the cervix remain to be determined. The strong association between the presence of EBV and cervical disease warrants future exploration to determine whether EBV plays a causal role in disease development or if it is merely a bystander in the process.

Research paper thumbnail of Supplementary Data from Determinants of VIA (Visual Inspection of the Cervix After Acetic Acid Application) Positivity in Cervical Cancer Screening of Women in a Peri-Urban Area in Andhra Pradesh, India

Supplementary Data from Determinants of VIA (Visual Inspection of the Cervix After Acetic Acid Ap... more Supplementary Data from Determinants of VIA (Visual Inspection of the Cervix After Acetic Acid Application) Positivity in Cervical Cancer Screening of Women in a Peri-Urban Area in Andhra Pradesh, India

Research paper thumbnail of Data from Determinants of VIA (Visual Inspection of the Cervix After Acetic Acid Application) Positivity in Cervical Cancer Screening of Women in a Peri-Urban Area in Andhra Pradesh, India

Objectives: Visual inspection of the cervix after acetic acid application (VIA) is widely recomme... more Objectives: Visual inspection of the cervix after acetic acid application (VIA) is widely recommended as the method of choice in cervical cancer screening programs in resource-limited settings because of its simplicity and ability to link with immediate treatment. In testing the effectiveness of VIA, human papillomavirus DNA testing, and Pap cytology in a population-based study in a peri-urban area in Andhra Pradesh, India, we found the sensitivity of VIA for detection of cervical intraepithelial neoplasia grade 2 and worse (CIN2+) to be 26.3%, much lower than the 60% to 90% reported in the literature. We therefore investigated the determinants of VIA positivity in our study population.Methods: We evaluated VIA positivity by demographics and reproductive history, results of clinical examination, and results from the other screening methods.Results: Of the 19 women diagnosed with CIN2+, only 5 were positive by VIA (positive predictive value, 3.1%). In multivariate analysis, VIA posit...

Research paper thumbnail of The FASEB Journal • Hypothesis The wild-type Ras: road ahead

The cellular Ras is known to play an important role in cellular proliferation mediated by growth ... more The cellular Ras is known to play an important role in cellular proliferation mediated by growth factor receptor. Evidence also points to its role in growth arrest. Substantiated proof for growth-suppressive activity of wild-type Ras comes from studies that showed 1) loss of wild-type ras allele in tumors, 2) suppression of growth in cells transformed by oncogenic ras upon overexpression of wild-type Ras, and 3) up-regulation of Ras expression during postnatal development and following growth arrest of untransformed cells in culture. To understand the mechanism by which the wild-type Ras brings about these diverse actions, we evaluated its well-known role in actively proliferating cells and its less understood role in growth arrest. This led to the proposal that wild-type Ras in either GDP or GTP-bound state can antagonize the function of oncogenic

Research paper thumbnail of DNA Methylation Profile at the DNMT3L Promoter

Epigenetic events play a prominent role during cancer development. This is evident from the fact ... more Epigenetic events play a prominent role during cancer development. This is evident from the fact that almost all cancer types show aberrant DNA methylation. These abnormal DNA methylation levels are not restricted to just a few genes but affect the whole genome. Previous studies have shown genome‑wide DNA hypomethylation and gene‑specific hypermethylation to be a hallmark of most cancers. Molecules like DNA methyltransferase act as effectors of epigenetic reprogramming. In the present study we have examined the possibility that the reprogramming genes themselves undergo epigenetic modifications reflecting their changed transcriptional status during cancer development. Comparison of DNA methylation status between the normal and cervical cancer samples was carried out at the promoters of a few reprogramming molecules. Our study revealed statistically significant DNA methylation differences within the promoter of DNMT3L. A regulator of de novo DNA methyltransferases DNMT3A and DNMT3B, ...

Research paper thumbnail of P589 The influence of preconception vaginal microbiota on preterm birth

Poster Presentations, 2019

more variation in reports of minority taxa and relative abundances. Standardized use of mock comm... more more variation in reports of minority taxa and relative abundances. Standardized use of mock communities may improve reproducibility across vaginal microbiota studies. Disclosure No significant relationships.

Research paper thumbnail of Correlation of plasma nitrite/nitrate levels and inducible nitric oxide gene expression among women with cervical abnormalities and cancer

Nitric Oxide, 2016

Cervical cancer is caused by infection with high risk human papillomavirus (HR-HPV). Inducible ni... more Cervical cancer is caused by infection with high risk human papillomavirus (HR-HPV). Inducible nitric oxide synthase (iNOS), a soluble factor involved in chronic inflammation, may modulate cervical cancer risk among HPV infected women. The aim of the study was to measure and correlate plasma nitrite/nitrate levels with tissue specific expression of iNOS mRNA among women with different grades of cervical lesions and cervical cancer. Tissue biopsy and plasma specimens were collected from 120 women with cervical neoplasia or cancer (ASCUS, LSIL, HSIL and invasive cancer) and 35 women without cervical abnormalities. Inducible nitric oxide synthase (iNOS) mRNA from biopsy and plasma nitrite/nitrate levels of the same study subjects were measured. Single nucleotide polymorphism (SNP) analysis was performed on the promoter region and Ser608Leu (rs2297518) in exon 16 of the iNOS gene. Differences in iNOS gene expression and plasma nitrite/nitrate levels were compared across disease stage using linear and logistic regression analysis. Compared to normal controls, women diagnosed with HSIL or invasive cancer had a significantly higher concentration of plasma nitrite/nitrate and a higher median fold-change in iNOS mRNA gene expression. Genotyping of the promoter region showed three different variations: A pentanucleotide repeat (CCTTT) n, -1026T > G (rs2779249) and a novel variant -1153T > A. These variants were associated with increased levels of plasma nitrite/nitrate across all disease stages. The higher expression of iNOS mRNA and plasma nitrite/nitrate among women with pre-cancerous lesions suggests a role for nitric oxide in the natural history of cervical cancer.

Research paper thumbnail of Downregulation of calcineurin activity in cervical carcinoma

Cancer cell international, 2005

BACKGROUND: Calcineurin (CaN) is an important serine-threonine phosphatase (PP2B), which plays a ... more BACKGROUND: Calcineurin (CaN) is an important serine-threonine phosphatase (PP2B), which plays a crucial role in calcium-calmodulin mediated signal transduction events. Calcineurin has been implicated in pathogenesis of various diseases cardiac hypertrophy, diabetic neuropathy and Alzheimer's, however its role in neoplasia remains unclear. RESULTS: In view of this we evaluated the calcineurin activity in serum and biopsy samples collected from women diagnosed with invasive squamous cell carcinoma of cervix. A significant reduction was observed in the calcineurin activity in cancer cervix patients compared to the control group. However the calcineurin activity remained unaltered in the cervical scrapes obtained from patients diagnosed with low-grade squamous intra epithelial lesions (LSIL). Interestingly the downregulation of calcineurin activity in squamous cell carcinomas was not accompanied by any significant change in DNA-binding affinity of the transcriptional factor NFAT (N...

Research paper thumbnail of The wild‐type Ras: road ahead

The FASEB Journal, 2005

The cellular Ras is known to play an important role in cellular proliferation mediated by growth ... more The cellular Ras is known to play an important role in cellular proliferation mediated by growth factor receptor. Evidence also points to its role in growth arrest. Substantiated proof for growth-suppressive activity of wild-type Ras comes from studies that showed 1) loss of wild-type ras allele in tumors, 2) suppression of growth in cells transformed by oncogenic ras upon overexpression of wild-type Ras, and 3) up-regulation of Ras expression during postnatal development and following growth arrest of untransformed cells in culture. To understand the mechanism by which the wild-type Ras brings about these diverse actions, we evaluated its well-known role in actively proliferating cells and its less understood role in growth arrest. This led to the proposal that wild-type Ras in either GDP or GTP-bound state can antagonize the function of oncogenic Ras.-Singh, A., Sowjanya, A. P., Ramakrishna, G. The wild-type Ras: road ahead.

Research paper thumbnail of Shedding of Epstein-Barr Virus and Cytomegalovirus from the Genital Tract of Women in a Periurban Community in Andhra Pradesh, India

Journal of Clinical Microbiology, 2011

We found a large number of false-positive readings by visual inspection with acetic acid (VIA) in... more We found a large number of false-positive readings by visual inspection with acetic acid (VIA) in a study of cervical cancer screening strategies (VIA, human papillomavirus HPV DNA testing, and Pap cytology) in a periurban community in Andhra Pradesh, India. We evaluated whether these false-positive readings might be occurring as a result of infections with Epstein-Barr virus (EBV) or cytomegalovirus (CMV), prevalent latent herpesviruses known to be shed from the female genital tract. While we found that there was no association between VIA results and the presence of EBV or CMV in the cervix, we did find a high prevalence of both viruses: 20% for EBV and 26% for CMV. In multivariate analyses, CMV prevalence was associated with younger age, lack of running water in the home, and visually apparent cervical inflammation. EBV prevalence was associated with older age and a diagnosis of cervical intraepithelial neoplasia grade 1 or greater. The biological and clinical implications of the...

Research paper thumbnail of Indian women with higher serum concentrations of folate and vitamin B12 are significantly less likely to be infected with carcinogenic or high-risk (HR) types of human papillomaviruses (HPVs)

International Journal of Women's Health, 2010

Background: Studies conducted in the USA have demonstrated that micronutrients such as folate and... more Background: Studies conducted in the USA have demonstrated that micronutrients such as folate and vitamin B12 play a significant role in modifying the natural history of high-risk human papillomaviruses (HR-HPVs), the causative agent for developing invasive cervical cancer (CC) and its precursor lesions. Objective: The purpose of the current study was to investigate whether these micronutrients have similar effects on HR-HPV infections in Indian women. Methods: The associations between serum concentrations of folate and vitamin B12 and HR-HPV infections were evaluated in 724 women who participated in a CC screening study in the southern state of Andhra Pradesh, India. Serum folate and vitamin B12 concentrations were measured by using a competitive radio-binding assay. Digene hybrid capture 2 (HC2) assay results were used to categorize women into two groups, positive or negative for HR-HPVs. Unconditional logistic regression models specified a binary indicator of HC2 (positive/negative) as the dependent variable and serum folate concentrations combined with serum vitamin B12 concentrations as the independent predictor of primary interest. Models were fitted, adjusting for age, education, marital status, parity, type of fuel used for cooking and smoking status. Results: Women with higher concentrations of serum folate (6 ng/mL) and vitamin B12 (356 pg/mL) were at lower risk of being positive for HR-HPVs compared to those with serum folate 6 ng/mL and serum vitamin B12  356 pg/mL (odds ratio = 0.26; 95% confidence interval: 0.08-0.89; P = 0.03). Conclusions: These results demonstrated that improving folate and vitamin B12 status in Indian women may have a beneficial impact on the prevention of CC. Micronutrient based interventions for control of HR-HPV infections may represent feasible alternatives to vaccine based approaches to HPV disease prevention, which are currently unaffordable for use in resource limited areas in rural India.

Research paper thumbnail of DNA Methylation Profile at the DNMT3L Promoter: A Potential Biomarker for Cervical Cancer

Research paper thumbnail of Development and characterization of ten novel microsatellite markers from olive ridley sea turtle (Lepidochelys olivacea)

Conservation Genetics, 2007

A microsatellite-enriched library was constructed and a set of 19 SSR markers were developed to c... more A microsatellite-enriched library was constructed and a set of 19 SSR markers were developed to characterize a germplasm collection of Hyptis pectinata (L.) Poit., maintained at the Universidade Federal de Sergipe (UFS). Fifteen markers of 19 ranged from moderately to highly polymorphic. A total of 113 alleles were identified, with a mean of 7.52 alleles per locus. The mean H O and H E were 0.582 and 0.657, respectively. The primers developed were efficient tools for accessing the genetic diversity of the germplasm collection analyzed and may also be useful for other studies involving this species and other species in the genus Hyptis.

Research paper thumbnail of Suitability of Self-Collected Vaginal Samples for Cervical Cancer Screening in Periurban Villages in Andhra Pradesh, India

Cancer Epidemiology, Biomarkers & Prevention, 2009

Objectives: Our aim was to determine if (1) Hybrid Capture 2 and a PCR-based method were comparab... more Objectives: Our aim was to determine if (1) Hybrid Capture 2 and a PCR-based method were comparable for detection of high-risk human papillomavirus (HPV) clinician-collected and self-collected samples were equally efficient to detect HPV and cervical cancer precursor lesions, and (3) if participation rates improved with home-based versus clinic-based self collection. Methods: Samples were selected from women participating in a cervical cancer screening study according to HPV, visual inspection with acetic acid, or Pap smear screening results. From 432 of 892 selected women, split sample aliquots were tested for HPV DNA using both the Hybrid Capture 2 assay and the Roche prototype line blot assay. Women from a subset of villages were recruited at two separate time points for clinic-based self-collection and home-based self-collection, and participation rates were compared. Results: Pairwise agreement between self- and clinician-collected samples was high by both Hybrid Capture 2 (90....

Research paper thumbnail of Determinants of VIA (Visual Inspection of the Cervix After Acetic Acid Application) Positivity in Cervical Cancer Screening of Women in a Peri-Urban Area in Andhra Pradesh, India

Cancer Epidemiology, Biomarkers & Prevention, 2010

Objectives: Visual inspection of the cervix after acetic acid application (VIA) is widely recomme... more Objectives: Visual inspection of the cervix after acetic acid application (VIA) is widely recommended as the method of choice in cervical cancer screening programs in resource-limited settings because of its simplicity and ability to link with immediate treatment. In testing the effectiveness of VIA, human papillomavirus DNA testing, and Pap cytology in a population-based study in a peri-urban area in Andhra Pradesh, India, we found the sensitivity of VIA for detection of cervical intraepithelial neoplasia grade 2 and worse (CIN2+) to be 26.3%, much lower than the 60% to 90% reported in the literature. We therefore investigated the determinants of VIA positivity in our study population. Methods: We evaluated VIA positivity by demographics and reproductive history, results of clinical examination, and results from the other screening methods. Results: Of the 19 women diagnosed with CIN2+, only 5 were positive by VIA (positive predictive value, 3.1%). In multivariate analysis, VIA pos...

Research paper thumbnail of Presence of RAS Mutations but No Role of BRAF and Beta-Catenin Mutations Together With Human Papilloma Virus (HPV) In Squamous Cell Carcinoma of Esophagus In a …

… of the American …, 2006

Worldwide esophageal cancer ranks among the ten most common cancers. Although, there is a rising ... more Worldwide esophageal cancer ranks among the ten most common cancers. Although, there is a rising entity of adenocarcinoma, the majority of carcinoma of the esophagus are squamous-cell carcinoma. It shows uneven geographical distribution in its occurrence, ...

Research paper thumbnail of Detection of Genomic Amplification of the Human Telomerase Gene TERC, a Potential Marker for Triage of Women with HPV-Positive, Abnormal Pap Smears

The American Journal of Pathology, 2009

Research paper thumbnail of DNA Methylation Profile at the DNMT3L Promoter

Research paper thumbnail of Shedding of Epstein-Barr Virus and Cytomegalovirus from the Genital Tract of Women in a Periurban Community in Andhra Pradesh, India

Journal of Clinical Microbiology, Jul 1, 2011

We found a large number of false-positive readings by visual inspection with acetic acid (VIA) in... more We found a large number of false-positive readings by visual inspection with acetic acid (VIA) in a study of cervical cancer screening strategies (VIA, human papillomavirus HPV DNA testing, and Pap cytology) in a periurban community in Andhra Pradesh, India. We evaluated whether these false-positive readings might be occurring as a result of infections with Epstein-Barr virus (EBV) or cytomegalovirus (CMV), prevalent latent herpesviruses known to be shed from the female genital tract. While we found that there was no association between VIA results and the presence of EBV or CMV in the cervix, we did find a high prevalence of both viruses: 20% for EBV and 26% for CMV. In multivariate analyses, CMV prevalence was associated with younger age, lack of running water in the home, and visually apparent cervical inflammation. EBV prevalence was associated with older age and a diagnosis of cervical intraepithelial neoplasia grade 1 or greater. The biological and clinical implications of these viruses at the cervix remain to be determined. The strong association between the presence of EBV and cervical disease warrants future exploration to determine whether EBV plays a causal role in disease development or if it is merely a bystander in the process.

Research paper thumbnail of Supplementary Data from Determinants of VIA (Visual Inspection of the Cervix After Acetic Acid Application) Positivity in Cervical Cancer Screening of Women in a Peri-Urban Area in Andhra Pradesh, India

Supplementary Data from Determinants of VIA (Visual Inspection of the Cervix After Acetic Acid Ap... more Supplementary Data from Determinants of VIA (Visual Inspection of the Cervix After Acetic Acid Application) Positivity in Cervical Cancer Screening of Women in a Peri-Urban Area in Andhra Pradesh, India

Research paper thumbnail of Data from Determinants of VIA (Visual Inspection of the Cervix After Acetic Acid Application) Positivity in Cervical Cancer Screening of Women in a Peri-Urban Area in Andhra Pradesh, India

Objectives: Visual inspection of the cervix after acetic acid application (VIA) is widely recomme... more Objectives: Visual inspection of the cervix after acetic acid application (VIA) is widely recommended as the method of choice in cervical cancer screening programs in resource-limited settings because of its simplicity and ability to link with immediate treatment. In testing the effectiveness of VIA, human papillomavirus DNA testing, and Pap cytology in a population-based study in a peri-urban area in Andhra Pradesh, India, we found the sensitivity of VIA for detection of cervical intraepithelial neoplasia grade 2 and worse (CIN2+) to be 26.3%, much lower than the 60% to 90% reported in the literature. We therefore investigated the determinants of VIA positivity in our study population.Methods: We evaluated VIA positivity by demographics and reproductive history, results of clinical examination, and results from the other screening methods.Results: Of the 19 women diagnosed with CIN2+, only 5 were positive by VIA (positive predictive value, 3.1%). In multivariate analysis, VIA posit...

Research paper thumbnail of The FASEB Journal • Hypothesis The wild-type Ras: road ahead

The cellular Ras is known to play an important role in cellular proliferation mediated by growth ... more The cellular Ras is known to play an important role in cellular proliferation mediated by growth factor receptor. Evidence also points to its role in growth arrest. Substantiated proof for growth-suppressive activity of wild-type Ras comes from studies that showed 1) loss of wild-type ras allele in tumors, 2) suppression of growth in cells transformed by oncogenic ras upon overexpression of wild-type Ras, and 3) up-regulation of Ras expression during postnatal development and following growth arrest of untransformed cells in culture. To understand the mechanism by which the wild-type Ras brings about these diverse actions, we evaluated its well-known role in actively proliferating cells and its less understood role in growth arrest. This led to the proposal that wild-type Ras in either GDP or GTP-bound state can antagonize the function of oncogenic

Research paper thumbnail of DNA Methylation Profile at the DNMT3L Promoter

Epigenetic events play a prominent role during cancer development. This is evident from the fact ... more Epigenetic events play a prominent role during cancer development. This is evident from the fact that almost all cancer types show aberrant DNA methylation. These abnormal DNA methylation levels are not restricted to just a few genes but affect the whole genome. Previous studies have shown genome‑wide DNA hypomethylation and gene‑specific hypermethylation to be a hallmark of most cancers. Molecules like DNA methyltransferase act as effectors of epigenetic reprogramming. In the present study we have examined the possibility that the reprogramming genes themselves undergo epigenetic modifications reflecting their changed transcriptional status during cancer development. Comparison of DNA methylation status between the normal and cervical cancer samples was carried out at the promoters of a few reprogramming molecules. Our study revealed statistically significant DNA methylation differences within the promoter of DNMT3L. A regulator of de novo DNA methyltransferases DNMT3A and DNMT3B, ...

Research paper thumbnail of P589 The influence of preconception vaginal microbiota on preterm birth

Poster Presentations, 2019

more variation in reports of minority taxa and relative abundances. Standardized use of mock comm... more more variation in reports of minority taxa and relative abundances. Standardized use of mock communities may improve reproducibility across vaginal microbiota studies. Disclosure No significant relationships.

Research paper thumbnail of Correlation of plasma nitrite/nitrate levels and inducible nitric oxide gene expression among women with cervical abnormalities and cancer

Nitric Oxide, 2016

Cervical cancer is caused by infection with high risk human papillomavirus (HR-HPV). Inducible ni... more Cervical cancer is caused by infection with high risk human papillomavirus (HR-HPV). Inducible nitric oxide synthase (iNOS), a soluble factor involved in chronic inflammation, may modulate cervical cancer risk among HPV infected women. The aim of the study was to measure and correlate plasma nitrite/nitrate levels with tissue specific expression of iNOS mRNA among women with different grades of cervical lesions and cervical cancer. Tissue biopsy and plasma specimens were collected from 120 women with cervical neoplasia or cancer (ASCUS, LSIL, HSIL and invasive cancer) and 35 women without cervical abnormalities. Inducible nitric oxide synthase (iNOS) mRNA from biopsy and plasma nitrite/nitrate levels of the same study subjects were measured. Single nucleotide polymorphism (SNP) analysis was performed on the promoter region and Ser608Leu (rs2297518) in exon 16 of the iNOS gene. Differences in iNOS gene expression and plasma nitrite/nitrate levels were compared across disease stage using linear and logistic regression analysis. Compared to normal controls, women diagnosed with HSIL or invasive cancer had a significantly higher concentration of plasma nitrite/nitrate and a higher median fold-change in iNOS mRNA gene expression. Genotyping of the promoter region showed three different variations: A pentanucleotide repeat (CCTTT) n, -1026T > G (rs2779249) and a novel variant -1153T > A. These variants were associated with increased levels of plasma nitrite/nitrate across all disease stages. The higher expression of iNOS mRNA and plasma nitrite/nitrate among women with pre-cancerous lesions suggests a role for nitric oxide in the natural history of cervical cancer.

Research paper thumbnail of Downregulation of calcineurin activity in cervical carcinoma

Cancer cell international, 2005

BACKGROUND: Calcineurin (CaN) is an important serine-threonine phosphatase (PP2B), which plays a ... more BACKGROUND: Calcineurin (CaN) is an important serine-threonine phosphatase (PP2B), which plays a crucial role in calcium-calmodulin mediated signal transduction events. Calcineurin has been implicated in pathogenesis of various diseases cardiac hypertrophy, diabetic neuropathy and Alzheimer's, however its role in neoplasia remains unclear. RESULTS: In view of this we evaluated the calcineurin activity in serum and biopsy samples collected from women diagnosed with invasive squamous cell carcinoma of cervix. A significant reduction was observed in the calcineurin activity in cancer cervix patients compared to the control group. However the calcineurin activity remained unaltered in the cervical scrapes obtained from patients diagnosed with low-grade squamous intra epithelial lesions (LSIL). Interestingly the downregulation of calcineurin activity in squamous cell carcinomas was not accompanied by any significant change in DNA-binding affinity of the transcriptional factor NFAT (N...

Research paper thumbnail of The wild‐type Ras: road ahead

The FASEB Journal, 2005

The cellular Ras is known to play an important role in cellular proliferation mediated by growth ... more The cellular Ras is known to play an important role in cellular proliferation mediated by growth factor receptor. Evidence also points to its role in growth arrest. Substantiated proof for growth-suppressive activity of wild-type Ras comes from studies that showed 1) loss of wild-type ras allele in tumors, 2) suppression of growth in cells transformed by oncogenic ras upon overexpression of wild-type Ras, and 3) up-regulation of Ras expression during postnatal development and following growth arrest of untransformed cells in culture. To understand the mechanism by which the wild-type Ras brings about these diverse actions, we evaluated its well-known role in actively proliferating cells and its less understood role in growth arrest. This led to the proposal that wild-type Ras in either GDP or GTP-bound state can antagonize the function of oncogenic Ras.-Singh, A., Sowjanya, A. P., Ramakrishna, G. The wild-type Ras: road ahead.

Research paper thumbnail of Shedding of Epstein-Barr Virus and Cytomegalovirus from the Genital Tract of Women in a Periurban Community in Andhra Pradesh, India

Journal of Clinical Microbiology, 2011

We found a large number of false-positive readings by visual inspection with acetic acid (VIA) in... more We found a large number of false-positive readings by visual inspection with acetic acid (VIA) in a study of cervical cancer screening strategies (VIA, human papillomavirus HPV DNA testing, and Pap cytology) in a periurban community in Andhra Pradesh, India. We evaluated whether these false-positive readings might be occurring as a result of infections with Epstein-Barr virus (EBV) or cytomegalovirus (CMV), prevalent latent herpesviruses known to be shed from the female genital tract. While we found that there was no association between VIA results and the presence of EBV or CMV in the cervix, we did find a high prevalence of both viruses: 20% for EBV and 26% for CMV. In multivariate analyses, CMV prevalence was associated with younger age, lack of running water in the home, and visually apparent cervical inflammation. EBV prevalence was associated with older age and a diagnosis of cervical intraepithelial neoplasia grade 1 or greater. The biological and clinical implications of the...

Research paper thumbnail of Indian women with higher serum concentrations of folate and vitamin B12 are significantly less likely to be infected with carcinogenic or high-risk (HR) types of human papillomaviruses (HPVs)

International Journal of Women's Health, 2010

Background: Studies conducted in the USA have demonstrated that micronutrients such as folate and... more Background: Studies conducted in the USA have demonstrated that micronutrients such as folate and vitamin B12 play a significant role in modifying the natural history of high-risk human papillomaviruses (HR-HPVs), the causative agent for developing invasive cervical cancer (CC) and its precursor lesions. Objective: The purpose of the current study was to investigate whether these micronutrients have similar effects on HR-HPV infections in Indian women. Methods: The associations between serum concentrations of folate and vitamin B12 and HR-HPV infections were evaluated in 724 women who participated in a CC screening study in the southern state of Andhra Pradesh, India. Serum folate and vitamin B12 concentrations were measured by using a competitive radio-binding assay. Digene hybrid capture 2 (HC2) assay results were used to categorize women into two groups, positive or negative for HR-HPVs. Unconditional logistic regression models specified a binary indicator of HC2 (positive/negative) as the dependent variable and serum folate concentrations combined with serum vitamin B12 concentrations as the independent predictor of primary interest. Models were fitted, adjusting for age, education, marital status, parity, type of fuel used for cooking and smoking status. Results: Women with higher concentrations of serum folate (6 ng/mL) and vitamin B12 (356 pg/mL) were at lower risk of being positive for HR-HPVs compared to those with serum folate 6 ng/mL and serum vitamin B12  356 pg/mL (odds ratio = 0.26; 95% confidence interval: 0.08-0.89; P = 0.03). Conclusions: These results demonstrated that improving folate and vitamin B12 status in Indian women may have a beneficial impact on the prevention of CC. Micronutrient based interventions for control of HR-HPV infections may represent feasible alternatives to vaccine based approaches to HPV disease prevention, which are currently unaffordable for use in resource limited areas in rural India.

Research paper thumbnail of DNA Methylation Profile at the DNMT3L Promoter: A Potential Biomarker for Cervical Cancer

Research paper thumbnail of Development and characterization of ten novel microsatellite markers from olive ridley sea turtle (Lepidochelys olivacea)

Conservation Genetics, 2007

A microsatellite-enriched library was constructed and a set of 19 SSR markers were developed to c... more A microsatellite-enriched library was constructed and a set of 19 SSR markers were developed to characterize a germplasm collection of Hyptis pectinata (L.) Poit., maintained at the Universidade Federal de Sergipe (UFS). Fifteen markers of 19 ranged from moderately to highly polymorphic. A total of 113 alleles were identified, with a mean of 7.52 alleles per locus. The mean H O and H E were 0.582 and 0.657, respectively. The primers developed were efficient tools for accessing the genetic diversity of the germplasm collection analyzed and may also be useful for other studies involving this species and other species in the genus Hyptis.

Research paper thumbnail of Suitability of Self-Collected Vaginal Samples for Cervical Cancer Screening in Periurban Villages in Andhra Pradesh, India

Cancer Epidemiology, Biomarkers & Prevention, 2009

Objectives: Our aim was to determine if (1) Hybrid Capture 2 and a PCR-based method were comparab... more Objectives: Our aim was to determine if (1) Hybrid Capture 2 and a PCR-based method were comparable for detection of high-risk human papillomavirus (HPV) clinician-collected and self-collected samples were equally efficient to detect HPV and cervical cancer precursor lesions, and (3) if participation rates improved with home-based versus clinic-based self collection. Methods: Samples were selected from women participating in a cervical cancer screening study according to HPV, visual inspection with acetic acid, or Pap smear screening results. From 432 of 892 selected women, split sample aliquots were tested for HPV DNA using both the Hybrid Capture 2 assay and the Roche prototype line blot assay. Women from a subset of villages were recruited at two separate time points for clinic-based self-collection and home-based self-collection, and participation rates were compared. Results: Pairwise agreement between self- and clinician-collected samples was high by both Hybrid Capture 2 (90....

Research paper thumbnail of Determinants of VIA (Visual Inspection of the Cervix After Acetic Acid Application) Positivity in Cervical Cancer Screening of Women in a Peri-Urban Area in Andhra Pradesh, India

Cancer Epidemiology, Biomarkers & Prevention, 2010

Objectives: Visual inspection of the cervix after acetic acid application (VIA) is widely recomme... more Objectives: Visual inspection of the cervix after acetic acid application (VIA) is widely recommended as the method of choice in cervical cancer screening programs in resource-limited settings because of its simplicity and ability to link with immediate treatment. In testing the effectiveness of VIA, human papillomavirus DNA testing, and Pap cytology in a population-based study in a peri-urban area in Andhra Pradesh, India, we found the sensitivity of VIA for detection of cervical intraepithelial neoplasia grade 2 and worse (CIN2+) to be 26.3%, much lower than the 60% to 90% reported in the literature. We therefore investigated the determinants of VIA positivity in our study population. Methods: We evaluated VIA positivity by demographics and reproductive history, results of clinical examination, and results from the other screening methods. Results: Of the 19 women diagnosed with CIN2+, only 5 were positive by VIA (positive predictive value, 3.1%). In multivariate analysis, VIA pos...

Research paper thumbnail of Presence of RAS Mutations but No Role of BRAF and Beta-Catenin Mutations Together With Human Papilloma Virus (HPV) In Squamous Cell Carcinoma of Esophagus In a …

… of the American …, 2006

Worldwide esophageal cancer ranks among the ten most common cancers. Although, there is a rising ... more Worldwide esophageal cancer ranks among the ten most common cancers. Although, there is a rising entity of adenocarcinoma, the majority of carcinoma of the esophagus are squamous-cell carcinoma. It shows uneven geographical distribution in its occurrence, ...

Research paper thumbnail of Detection of Genomic Amplification of the Human Telomerase Gene TERC, a Potential Marker for Triage of Women with HPV-Positive, Abnormal Pap Smears

The American Journal of Pathology, 2009