Umadevi K Rao

Chemical and physical basics of routine formaldehyde fixation

Formaldehyde is the widely employed fixative that has been studied for decades. The chemistry of fixation has been studied widely since the early 20th century. However, very few studies have been focused on the actual physics/chemistry aspect of process of this fixation. This article attempts to explain the chemistry of formaldehyde fixation and also to study the physical aspects involved in the fixation. The factors involved in the fixation process are discussed using well documented mathematical and physical formulae. The deeper understanding of these factors will enable pathologist to optimize the factors and use them in their favor.

Oral lichen planus: An update on pathogenesis and treatment

Oral lichen planus (OLP) is a chronic inflammatory disease that affects the mucus membrane of the oral cavity. It is a T-cell mediated autoimmune disease in which the cytotoxic CD8+ T cells trigger apoptosis of the basal cells of the oral epithelium. Several antigen-specific and nonspecific inflammatory mechanisms have been put forward to explain the accumulation and homing of CD8+ T cells subepithelially and the subsequent keratinocyte apoptosis. A wide spectrum of treatment modalities is available, from topical corticosteroids to laser ablation of the lesion. In this review, we discuss the various concepts in the pathogenesis and current treatment modalities of OLP.

Orofacial and systemic manifestations in 212 paediatric HIV patients from Chennai, South India

BACKGROUND Lesions in the mouth and in other tissues and organs (oral and systemic lesions) in paediatric HIV infection are diverse and show differences in clinical presentation and severity from that of adults. Very little data exist for oral lesions in paediatric population in India. AIM To document and study oral and more widespread lesions in paediatric HIV seropositive patients. DESIGN A cross-sectional study. SETTING Paediatric HIV seropositive patients at tertiary centers: Ragas Dental College and Hospital and YRG CARE, Chennai, India. PATIENTS AND METHODS Two hundred and twelve paediatric HIV patients aged 0-14 years seen over a period of 1 year were included in the study. Clinical history, oral and systemic examinations were recorded by qualified dental surgeons and physicians. RESULTS One hundred and thirty-two patients had oral lesions ranging in number from one to three. Oral lesions included oral candidiasis (OC) (56.1%), gingivitis (10.8%), oral pigmentation (6.1%), depapillation of the tongue (5.7%), ulcers (4.2%), and oral hairy leukoplakia (1.4%). The most common systemic lesion observed was nonspecific lymphadenopathy (74.1%) followed by pruritic eruptions (53.8%), measles (51.4%), and tuberculosis (TB) (49.1%). Thirty-three (26%) patients were not immunosuppressed, 74 (58%) were moderately immunosuppressed, and 20 (15%) were severely immunosuppressed. Oral lesions exhibited positive correlation with lesions in other parts of the body. CONCLUSION Oral lesions are a common feature in paediatric HIV infection. Their management is vital to improve the quality of life of the infected children.

Tooth decay in alcohol and tobacco abusers.

Background: Alcohol and tobacco abuse are detrimental to general and oral health. Though the effects of these harmful habits on oral mucosa had been demonstrated, their independent and combined effect on the dental caries experience is unknown and worthy of investigation. Materials and Methods: We compared 268 alcohol-only abusers with 2426 alcohol and tobacco abusers in chewing and smoking forms to test the hypothesis that various components of their dental caries experience are significantly different due to plausible sociobiological explanations. Clinical examination, Decay, Missing, Filled Teeth (DMFT) Index and Oral Hygiene Index - Simplified were measured in a predetermined format. Descriptive statistics, Chi-square test and one-way ANOVA analysis were done using SPSS Version 16.0. Result: The mean DMFT were 3.31, 3.24, 4.09, 2.89 for alcohol-only abusers, alcohol and chewing tobacco abusers, smoking tobacco and alcohol abusers, and those who abused tobacco in smoke and smokeless forms respectively. There was no significant difference between the oral hygiene care measures between the study groups. Presence of attrition among chewers and those with extrinsic stains experienced less caries than others. Discussion and conclusion: The entire study population exhibited a higher incidence of caries experience. Use of tobacco in any form appears to substantially increase the risk for dental caries. Attrition with use of chewing tobacco and presence of extrinsic stains with tobacco use appear to provide a protective effect from caries. The changes in oral micro-flora owing to tobacco use and alcohol may play a critical role in the initiation and progression of dental caries.

Assessment of oral mucosa in normal, precancer and cancer using chemiluminescent illumination, toluidine blue supravital staining and oral exfoliative cytology

Context: Carcinoma in an early stage of development is hard to detect clinically because the lesion may not be palpable and color of the lesional tissue is not necessarily different from the color of the surrounding mucosa. In order to improve the efficacy of the diagnosis, techniques are being developed to complement clinical examination and to facilitate the identification of initial carcinomas. Aims: To find out the efficacy of chemiluminescent illumination (ViziLite™) for the diagnosis in precancer and cancer patients and compare this result to toluidine blue staining and oral exfoliative cytology. Materials and Methods: This study was done in 3 groups. Each group consists of 10 cases. Group I consists of normal appearing mucosa. Group II and III consist of clinically diagnosed pre-cancer and clinically suggestive of cancer respectively. Chemiluminescent illumination, toluidine blue supravital staining, oral exfoliative cytology and biopsy were performed in all cases. Statistical analysis used: SPSS version 10.05 was used to calculate positive and negative predictive values. Results: In Group I, all 10 patients showed negative result to ViziLite™. 8 patients showed positivity and 2 patients showed negativity to ViziLite™ test in Group II. 9 patients were positive and one patient was negative for ViziLite™. Conclusions: Chemiluminescent illumination test was sensitive for precancerous and cancerous lesions, which presented as keratotic lesions and red-white lesions. It showed negative result to erosive lesions. Toluidine blue staining test was reliable in precancerous and cancerous lesions, which present as erosive and red-white lesions. It showed negative result to keratotic lesions. Oral exfoliative cytology has diagnostic value in cancer patients than in precancer patients. These Results indicate that chemiluminescent illumination test is relatively reliable and accurate than toluidine blue staining test and useful chair side diagnostic test.

Concepts in sample size determination.

Investigators involved in clinical, epidemiological or translational research, have the drive to publish their results so that they can extrapolate their findings to the population. This begins with the preliminary step of deciding the topic to be studied, the subjects and the type of study design. In this context, the researcher must determine how many subjects would be required for the proposed study. Thus, the number of individuals to be included in the study, i.e., the sample size is an important consideration in the design of many clinical studies. The sample size determination should be based on the difference in the outcome between the two groups studied as in an analytical study, as well as on the accepted p value for statistical significance and the required statistical power to test a hypothesis. The accepted risk of type I error or alpha value, which by convention is set at the 0.05 level in biomedical research defines the cutoff point at which the p value obtained in the study is judged as significant or not. The power in clinical research is the likelihood of finding a statistically significant result when it exists and is typically set to >80%. This is necessary since the most rigorously executed studies may fail to answer the research question if the sample size is too small. Alternatively, a study with too large a sample size will be difficult and will result in waste of time and resources. Thus, the goal of sample size planning is to estimate an appropriate number of subjects for a given study design. This article describes the concepts in estimating the sample size.

Prevalence and correlates of tobacco use among urban adult men in India: A comparison of slum dwellers vs non-slum dwellers

BACKGROUND Tobacco use is reported to be rampant in urban slums in developing countries. Demographical variations in tobacco use between males living in urban slums vs those living in non-slum areas in India has not been reported, and this study was undertaken to address this issue. MATERIALS AND METHODS Secondary data analysis of National Family Health Survey-3 (NFHS-3) was undertaken to study demographical variations in tobacco use between urban slum dwellers and non-slum dwellers in eight Indian cities. Demographic determinants for use of smoking and chewing forms of tobacco in the two groups were analyzed. SPSS version 16.0 (SPSS Inc., IL, USA) was used for statistical analysis. RESULT The study population comprised 6887 (41.8%) males from slum areas and 9588 (58.2%) from non-slum areas of eight urban cities. Cigarette/beedi smoking was the commonest form of tobacco use among the study population. Pan masala use was the least common form of smokeless tobacco use, next only to snuff. There was a high statistical significance observed within the various demographic parameter studied in both the slum and non-slum dwelling males in study population. However, on studying the differences between the two groups, it was observed that statistical significance of P≤.001 was observed with age (15-49), secondary education, religion, household structure and marital status. The difference between the two groups in the mean number of cigarettes/beedis smoked was not statistically significant (P=.598). DISCUSSION AND CONCLUSION Male slum dwellers are a distinct urban population, whose health needs assessment requires a different approach than that for non-slum dwellers who often can afford the services that an urban Indian city can offer.

Gender differences in oral lesions among persons with HIV disease in Southern India

Introduction: In India, it is estimated that 2.5 million people are currently living with Human Immunodeficiency virus infection (HIV) of which one million are women. Given the occurrence of oral lesions in our population, we studied the patter of these lesions with respect to the role played by gender. Materials and Methods: 3729 consecutive patients seen over a period of 10 years (from 1998 to 2008) attending the YRG CARE (Center for AIDS Research and Education), at Chennai, India constituted the study group. The oral lesions were diagnosed and the findings were entered into a database and analysed using the SPSS package SPSS11. Results: 3724 adult patients (71% males 29% females) were recruited in this study. 95% and 92% of males and females respectively acquired the infection through the heterosexual route. 69% of them presented with at least one oral lesion. There was a significant difference in the occurrence of oral candidiasis (OC) (18.8% males 10.3% females, P = 0.00) and oral hairy leukoplakia (OHL) (1.2% males 0.4% females, P = 0.023) between gender. The mean CD4 counts in males (n = 1908) was 284.48 ± 222.45 and in females (n = 1087) it was 394.51 ± 274.56. Males had 2.2 times higher risk of getting OC, 3.1 times higher risk of OHL and over all males had 1.58 times of having any oral lesion compared to females. Multivariate logistic regression that the odds of having OC (OR = 1.7, 95%CI 1.2-2.2, P = 0.001) and OHL (OR = 3.1, 95%CI 1.1-8.9; P = 0.03) were significantly higher for males than for females after controlling for duration of being HIV positive, CD4 count and HAART. 1412 patients had their spouses HIV status also as HIV positive and 769 patients had their spouse HIV status as negative. 858 patients were on HARRT (627 males and 231 females) The partial correlation analysis, done between gender and CD4 counts, when controlling for HAART was r = 0.2028 (P = 0.00). Conclusion: Our study confirms that males had a higher risk of oral lesions, especially OC and OHL, than females. The females in this study had a significantly higher mean CD4 counts than males. This different immunological status of the females compared to males should be taken in to consideration in the evaluation and management of HIV positive patients in our country.

Expression of p53 and Cyclin D1 in oral squamous cell carcinoma and normal mucosa: An Immunohistochemical study

Aim: To assess p53 and Cyclin D1 expression using Immunohistochemistry in normal mucosa and oral squamous cell carcinoma. Materials and Methods: Twenty cases of Oral squamous cell carcinoma (OSCC) and 10 normal mucosa were used and the primary antibodies used were p53 (DAKO-DO7) and Cyclin D1 Mouse Anti human Cyclin D1 (DCS-6) 1: 100 dilution. Statistical analysis: Labelling index was calculated and mean LI and SD were calculated, using Descriptive Statistics and t-test was used to compare mean LI between antibodies used in OSCC. Percentage positivity was done by Chi-Square test. Comparison of LI between p53 and Cyclin D1 was studied using t test. Results: p53 was positive in 30% and Cyclin D1 in40% of normal cases and 65% and 95% of OSCC were positive for p53 and Cyclin D1 respectively. Mean LI of p53 and Cyclin D1 were found to be statistically significant between the normal mucosa and OSCC. The correlation of mean LI of p53 and Cyclin D1 in OSCC was found to be statistically significant. LI of p53 was found to be higher than Cyclin D1 in OSCC. Conclusion: In the present study, increased p53 and Cyclin D1 expression were seen in OSCC when compared to the normal mucosa and a positive correlation was seen between increased p53 and Cyclin D1 expression in OSCC.

Review of paraneoplastic syndromes associated with oropharyngeal squamous cell carcinoma

Malignancies are usually preceded by the presence of various paraneoplastic syndromes (PNS), which could be the indirect and/or remote effects of the metabolites produced by neoplastic cells. PNS manifested by oropharyngeal squamous cell carcinomas, which is the most common head and neck malignancy, are highlighted in this review. Knowledge of the clinical spectrum of these syndromes will equip the oral physician for early diagnosis and management of these hidden malignancies, especially of the pharyngeal region.