Sridhar H

Oral cancer in southern India: The influence of smoking, drinking, paan‐chewing and oral hygiene

Between 1996 and 1999 we carried out a case‐control study in 3 areas in Southern India (Bangalore, Madras and Trivandrum) including 591 incident cases of cancer of the oral cavity (282 women) and 582 hospital controls (290 women), frequency‐matched with cases by age and gender. Odds ratios (ORs) and 95% confidence intervals (CIs) were obtained from unconditional multiple logistic regressions and adjusted for age, gender, center, education, chewing habit and (men only) smoking and drinking habits. Low educational attainment, occupation as a farmer or manual worker and various indicators of poor oral hygiene were associated with significantly increased risk. An OR of 2.5 (95% CI 1.4–4.4) was found in men for smoking ≥ 20 bidi or equivalents versus 0/day. The OR for alcohol drinking was 2.2 (95% CI 1.4–3.3). The OR for paan chewing was more elevated among women (OR 42; 95% CI 24–76) than among men (OR 5.1; 95% CI 3.4–7.8). A similar OR was found among chewers of paan with (OR 6.1 in men and 46 in women) and without tobacco (OR 4.2 in men and 16.4 in women). Among men, 35% of oral cancer is attributable to the combination of smoking and alcohol drinking and 49% to pan‐tobacco chewing. Among women, chewing and poor oral hygiene explained 95% of oral cancer.

Oral cancer in Southern India: the influence of body size, diet, infections and sexual practices

Between 1996 and 1999, we carried out a study in Southern India on risk factors for oral cancer. The study included 591 incident cases of cancer of the oral cavity (282 women) and 582 hospital controls (290 women). Height was unrelated to oral cancer risk. Body mass index (weight in kilograms/height in metres squared) was inversely associated with risk (P for trend<0.001). Paan chewers with low BMI were at particularly high risk. Risk was increased among subjects consuming meat (odds ratio (OR) 1.54, 95% confidence interval (CI) 1.00–2.37), ham and salami (OR 4.40, 95% CI 2.88–6.71) two or more times per week. Frequent consumption of fish, eggs, raw green vegetables, cruciferous vegetables, carrots, pulses, apples or pears, citrus fruit, and overall consumption of vegetables and fruit decreased oral cancer risk (P for trend for each of these items less than or equal to 0.001). The risk associated with low consumption of vegetables was higher among smokers than among non-smokers. Men, but not women, who practised oral sex had an increased oral cancer risk (OR 3.14, 95% CI 1.15–8.63). Women with more than one sexual partner during life were at increased oral cancer risk (OR 9.93, 95% CI 1.57–62.9).

High incidence of oligozoospermia and teratozoospermia in human semen infected with the aerobic bacterium Streptococcus faecalis

Bacterial culture of semen samples from 100 male partners in infertile couples revealed the presence of aerobic bacteria in 49 cases. Streptococcus faecalis (Enterococcus) was isolated from 53%, micrococci species from 20% and alpha-haemolytic streptococci from 16% of the infected samples. The incidence of oligozoospermia and teratozoospermia was significantly (P < 0.05) higher in men whose semen samples contained S. faecalis than those whose semen samples contained micrococci or alpha-haemolytic streptococci or those that did not contain bacteria. The mean sperm concentration, as well as the mean percentage of morphologically normal spermatozoa, was significantly (P < 0.03) lower in semen infected with S. faecalis compared with that containing micrococci or alpha-haemolytic streptococci and the uninfected samples. There is a high incidence of semen infection with S. faecalis, and it is associated with compromised semen quality in terms of sperm concentration and morphology. The presence of micrococci or alpha-haemolytic streptococci does not appear to have any detrimental effect on sperm quality.

Invasive aspergillosis in cancer

Summary.  Ten confirmed cases of invasive aspergillosis (IA) in cancer patients were analysed retrospectively. Eight were pulmonary, one was sinonasal and one was cutaneous. The majority of patients had haematological malignancies (7), the remaining three were cases of solid tumours. Fever was present in all 10 cases. Cough and lung signs were present in all eight cases of invasive pulmonary aspergillosis. Haemoptysis was encountered in three of nine cases of pulmonary and sinonasal aspergillosis. Mortality was low (2%). While corticosteroids, antibiotics and anticancer chemotherapy/radiotherapy were factors predisposing the patients to IA, neutropenia was perhaps responsible for their mortality. Seven of the patients had other associated pathogens isolated in culture in addition to Aspergillus spp. Aspergillus fumigatus was the predominant species, followed by A. flavus, A. glaucus, A. nidulans and A. niger. Direct microscopic examination (in six of seven cases) and culture (six of seven cases) correlated well with radiographic and clinical findings in cases with lung involvement. Serology for anti‐Aspergillus antibodies performed by gel diffusion precipitin test was positive in one case of sinonasal aspergillosis, wherein only one precipitin band was observed. Correlation of clinical symptoms, consistent radiographic findings and microbiological work‐up (the latter including a triad of direct microscopy, culture and serology) are required to arrive at a diagnosis of IA, especially where histology cannot form the mainstay of diagnosis.

Utility of molecular and serodiagnostic tools in cerebral toxoplasmosis with and without tuberculous meningitis in AIDS patients: A study from South India

Background: Antemortem diagnosis of cerebral toxoplasmosis, the second most common opportunistic infection (OI) in HIV-infected individuals in developing countries is a challenge. Materials and Methods: Toxoplasma gondii (T.gondii) -specific serology and nested polymerase chain reaction (nPCR) were evaluated in sera and ventricular/lumbar cerebrospinal fluid (CSF) of 22 autopsy confirmed cases of cerebral toxoplasmosis with HIV and 17 controls. Frequency of concomitant T.gondii infection was investigated in 17 cases of HIV-associated tuberculous meningitis (TBM). Results: The sensitivity, specificity, and positive and negative predictive values of T. gondii IgG on CSF (ventricular and lumbar) and sera was 100% in histology proven cerebral toxoplasmosis (concentrations: 258 ± 50, 231 ± 36, and 646 ± 243 IU/mL, respectively); majority (94%) being high avidity type, suggesting reactivation/reinfection. The sensitivity of B1 nPCR was 100% on ventricular CSF, whereas it was only 77% on lumbar CSF. Based on histology, nPCR, and IgG serology, T. gondii co-infection with TBM was observed in 65% (11/17) of cases. Discussion and Conclusion: CSF IgG serology and nPCR are tests with high sensitivity and specificity for the diagnosis of cerebral toxoplasmosis. TBM and cerebral toxoplasmosis can coexist and should be considered in the background of HIV infection in developing countries.

p53 tumor suppressor gene mutations in hepatocellular carcinoma patients in India.

We congratulate Katiyar et al. on their excellent study, which we believe is the first of its kind from our country. We understand that this study was directed primarily at studying p53 mutations in HCC as seen in India. However, we would like to highlight why the use of multiple primers/probes against hepatitis B virus (HBV) would be more appropriate in a study of this nature. During an acute HBV infection, hepatocytes producing viral particles are destroyed immunologically by a strong CD8 T-cell response that is targeted against HB core (HBc)/HB envelope (HBe) and HB surface (HBs) proteins expressed on the surface. This process also may lyse cells with integrated viral DNA, which are capable of expressing HBcAg/HBeAg and HBsAg. Thus, during carcinogenesis, there may be immune selection of cells with integrated viral DNA that are incapable of expressing HBcAg/HBeAg. Therefore, while investigating the association of HBV with HCC, it is essential to use probes/primers that encompass more than one region of the viral genome. This will ensure that even HCC cells bearing incomplete HBV genomes (e.g. those bearing either the surface (S)/core (C)/X genes alone or in combination) will be detected. If, however, specific probes/primers against any one region of the viral genome are used alone, it is likely that some cases harboring the viral genome may not be detected. In the paper under reference, PCR was negative for C gene, but serum HBsAg and HBeAg were positive in 2 of 21 cases (Cases 5, 6; Table 2 in their study). It would be interesting to know the results of S and X genes in these two cases, especially because they did show evidence of HBV infection, and in all probability may have the integrated HBV genome minus the C gene. Further, we would like to mention in passing that in a study that is currently underway at our center (unpublished data), we have come across HCC cases that were positive for S and X genes but negative for the C gene of the HBV. In India, because reports already have shown the association of HBV with HCC to be high, studies using such probes would corroborate such seroepidemiologic data and highlight the exact prevalence of the virus. Hence, it would be advisable to use a battery of primers/ probes against HBV with special reference to HCC.