Status of chromosome breaks and gaps in breast cancer. a follow-up study.

Genetic susceptibility and environmental factors are believed to be responsible for chromosomal instabilities and higher incidence of breast cancer. We conducted a follow-up study to find the levels of chromosome breaks and gaps in 20 premenopausal women with breast cancer before surgery, 1 month after surgery, and 3 years after surgery with respect to 20 age- and gender-matched controls. The mean level of chromosome breaks and gaps was found to be significantly higher (P<0.001) in breast cancer patients (before surgery) as compared with the controls. The chromosome breaks and gaps after 1 month of surgery were observed significantly decreased (P<0.005) when compared with that of patients before the surgery. Further significant increase in chromosome breaks and gaps was found after 3 years of surgery as compared with both the patients after 1 month of surgery (P<0.05) and controls (P<0.005). The significant increase in chromosome breaks and gaps in breast cancer patients (before surgery) may be due to the effects of genetic susceptibility to environmental carcinogens and endogenous factors. However, the decrease in this level after 1 month of surgery may be due to the removal of cancerous tissues, which in turn removes the effect of mutagens and clastogenic factors. Further increase in chromosome breaks and gaps after 3 years of surgery may be due to the long-term effects of therapeutic agents and genetic susceptibility to environmental carcinogens in the patients. The study furthermore suggests that the high level of chromosome breaks and gaps after 3 years of surgery may be a risk factor for the development of secondary tumor in patients.

Effect of nitric oxide and malondialdehyde on sister-chromatid exchanges in breast cancer.

Nitric oxide (NO) and malondialdehyde (MDA) play a significant role in DNA damage, sister-chromatid exchanges (SCEs) and carcinogenesis. Here, we determine plasma NO and MDA to evaluate their role in carcinogenesis and their effect on the frequency of SCEs in 45 female breast cancer patients and in 35 age- and sex-matched controls. Plasma NO (P<0.01) and MDA (P<0.001) was significantly higher in the breast cancer group, and a direct correlation were found between plasma NO and MDA concentration and tumour grade. Patients with stage II disease showed the highest levels of both NO and MDA, compared with controls. Simultaneously, SCE frequency per lymphocyte in the breast cancer group was found to be significantly (P<0.001) higher; the greatest increase being found in patients with stage IV disease. Positive correlation was found between SCEs and both NO and MDA in the breast cancer group; however, both NO and MDA production decreased with increasing severity of the disease. Lower NO production in stage IV disease may be due to lower expression of nitric oxide synthase (NOS), further facilitating the production of superoxide anions (O2*-). The reaction between NO and O2*- results in peroxynitrite (OONO-) formation, which works efficiently at the molecular level and may induce higher SCE frequency. This work suggests that further cytogenetic and molecular study is required to provide definite answers for the therapeutic use of NO in breast cancer.

Free oxygen radicals--predictors of neonatal outcome following perinatal asphyxia.

The study was undertaken to evaluate the role of free oxygen radicals in asphyxiated neonates. Thirty term neonates appropriate for gestational age and with severe birth asphyxia (Apgar score of 3 or less at 1 minute of life) formed the study subjects. The levels of superoxide dismutase (SOD), glutathione peroxidase (GPx), creatine phosphokinase (CPK) and lipid peroxidase (LPO) in the CSF of these neonates were estimated between 12 and 48 hrs of life. Enzyme estimation was performed by standard methods and the results were analysed statistically using Multivariate Logistic Regression analysis and non parametric tests namely Kruskal Wallis test and Wilcoxon's rank sum test. Out of the thirty babies, 14 were observed to be neurologically normal, 9 had significant morbidity and 7 died. The SOD levels ranged from 12.4 to 140 units/ml, GPx from 128 to 1933 nmol/min/dl, CPK from 2 to 2098 IU/dl and LPO from 5.4 to 30.8 umol/hr/dl. The SOD and GPx levels had an inverse relationship whereas rise in LPO and CPK levels were directly proportional to the extent of neurological damage and ultimate clinical outcome. CPK levels higher than 140 IU/ml were lethal and associated with 100% mortality whereas all normal neonates had CPK below 37 IU/ml. The levels of antioxidant enzymes can reliably and significantly predict mortality and morbidity whereas level of an enzyme cannot confidently confer normalcy. Hence antioxidant enzyme levels with a cut off value can be a useful marker and serve as a prognostic indicator in times to come.

Changes in anti-oxidant enzymes and lipid peroxidation in hyaline membrane disease.

This study was conducted to elucidate the changes in key antioxidant enzymes e.g. Superoxide dismutase (SOD), Catalase and Glutathione peroxidase (GPx) along with lipid peroxidation (LPO) in preterm newborns having hyaline membrane disease (HMD) and thus to find out role of free radicals mediated injury in this disease. Twenty one preterm appropriate for gestational age newborns were included in the study. Eleven of them had hyaline membrane disease and ten were controls without any disease. Status of superoxide dismutase, glutathione peroxidase and catalase, the three main antioxidant enzymes and lipid peroxidation was monitored at 12-24 hours of age. SOD and catalase were found significantly elevated in cases having hyaline membrane disease along with significantly more lipid peroxidation. It is evident that free radicals result in the induction of the antioxidant enzymes; however, the elevated enzymes are unable to counteract the high concentration of the free radicals which are being produced in the diseased cases and leads to increase in lipid peroxidation in hyaline membrane disease. It is concluded that free radicals play a significant role in hyaline membrane disease and the preterm newborns have ability to induce antioxidant enzymes in response to oxidative stress.

Seroepidemiology of hepatitis A in Delhi.

A prospective study was done to determine the age specific prevalence of antihepatitis A antibodies (anti HAV Abs) among children in Delhi. Four hundred and twenty children aged 0-12 years attending outpatient department for vaccination or any minor illness were studied. Sera was tested by ELISA for anti HAV Abs using a commercial kit (Hepvase A 96 TMB). Thirty samples of cord blood were similarly analyzed. All samples of cord blood were positive for anti HAV Abs. Prevalence of anti HAV Abs was 80% by 5 years of age. The most vulnerable age group was 0.5-1.5 years (anti HAV Ab positivity). Cord blood had 100% positivity. Univariate and multivariate analyses taking anti HAV antibody positivity as dependant variable demonstrated that age and father's education (socioeconomic status) significantly affect prevalence of anti HAV Abs. Sex, water supply, history of jaundice in self or family did not have any significant effect on anti HAV antibody positivity. Prevalence of anti HAV antibodies is 80% by 5 years of age. Further studies in different strata of society and different regions in the country are required to assess the need and age for vaccination.

Serum TNF-alpha and free radical scavengers in neonatal septicemia.

Tumor necrosis factor-alpha (TNF-alpha) and free radicals have been implicated in the pathogenesis of neonatal septicemia and its complications. This case control study was conducted between November 1996 to July 1997 to determine the levels of TNF-alpha and free radical scavengers viz. superoxide dismutase (SOD) and glutathione peroxidase (GPX) in the serum of 30 septic neonates and 20 healthy controls. Patients with neonatal sepsis registered significantly higher levels of TNF-alpha, SOD and GPX in comparison to controls (p < 0.05). The neonates with septic shock had five fold increase in TNF-alpha levels (2262 +/- 605.8 pg/ml) as compared to those without shock (738.8 +/- 728.8 pg/ml). There was no statistically significant difference in levels of antioxidant enzymes between neonates with shock and without shock. The levels of TNF-alpha and antioxidant enzymes were not affected by the type of organism isolated in blood culture.

CSF interleukin-1 beta, tumor necrosis factor-alpha and free radicals production in relation to clinical outcome in acute bacterial meningitis.

OBJECTIVE: To study the relationship of CSF IL-1 beta and TNF-alpha with free radicals in acute bacterial meningitis (ABM) and to evaluate the clinical outcome in relation to the levels of these cytokines and free radicals in CSF. DESIGN: Prospective with controls. SETTING: Referral unit of a teaching hospital. METHODS: 32 children between 3m-12 yrs of age with proven acute bacterial meningitis comprised the study group. In the control group, 20 children with febrile seizures were included. CSF cytokines- Interleukin Ib and tumour necrosis factor a,free radicals O(2)-, H(2)O(2) and enzymes SOD and CPK were measured in all the children. RESULTS: CSF IL-Ib and TNF-a concentration were markedly elevated in children with ABM (441.5 +/- 216.1 pg/ml, and 1009 +/- 529.1 pg/ml, respectively) as compared to controls (52.67 +/- 6.92 pg/ml, and 86.42 +/- 16.24 pg/ml) (p <0.0001). Free radicals viz., superoxide anion, hydrogen peroxide production and enzymes creatinine phosphokinase and superoxide dismutase were also significantly elevated in ABM as compared to controls. There was direct correlation of CSF cytokines with CSF cytology, protein and free radicals production in ABM. Patients who expired or had neurological sequelae had markedly elevated concentrations of cytokines and free radicals. CONCLUSION: IL-I beta, TNF-alpha and free radicals are significantly elevated in CSF of patients with ABM. The concentration of these cytokines correlated well with free radical production, and with routinely measured CSF parameters and had a direct bearing on outcome of ABM

Free oxygen radicals in acute renal failure.

OBJECTIVE: To assess the levels of free oxygen radicals in acute renal failure and their predictive value in clinical outcome. DESIGN: Prospective. SETTING: Intensive care unit. METHODS: Study was conducted in 50 children (25 with acute renal failure and 25 age and sex matched controls). Blood urea, serum creatinine, serum protein, uric acid and free oxygen radical markers were estimated in both groups. Superoxide dismutase (SOD), glutathione peroxidase(GPx) and lipid peroxide (LPO) were estimated in blood by standard techniques. RESULTS: Hemolytic uremic syndrome (HUS) was a major cause of acute renal failure (52%), rest were due to acute glomerulonephritis (AGN), septicemia and renal venous thrombosis. In the renal failure group 56% of the patients were dialyzed (peritoneal) and the mortality was 28% (7/25). The levels of SOD, GPx and LPO were significantly raised in renal failure group. Higher values of LPO, SOD and GPx were documented in subjects who expired. The most important independent variable for predicting clinical outcome was LPO with a sensitivity of 89.4%, specificity of 93%, positive predictive value of 95%. CONCLUSION: Levels of free oxygen radicals (SOD, LPO and GPx) are raised in acute renal failure and these enzymes can be used as marker of renal injury. LPO levels are highly sensitivity and specific for predicting the clinical outcome

Expression of aphidicolin-induced fragile sites and their relationship between genetic susceptibility in breast cancer, ovarian cancer, and non-small-cell lung cancer patients.

Fragile sites are nonrandomly located gaps and/or breaks and their expres-sion can be induced by specific culture conditions. There are many reports in the literature that indicate that these sites can act as factors that predispose to specific chromosome aberrations and other complex rearrangement in the chromosome and their association with cancers. In the present study, the expression of the fragile sites induced by aphidicolin was evaluated on prometaphase chromosomes from peripheral blood lymphocytes of 55 patients with breast cancer patients belonging to different stages of the cancer, 25 patients with epithelial ovarian cancer, and 13 with non-small-cell lung cancer, 100 of their first-degree clinically healthy female relatives, and 100 normal age-matched healthy persons without a familial history of cancer. The frequency of expression of the fragile sites in cancer patients and their first-degree relatives was found to be statistically significant (P<0.05) than those of the controls. In different stages of breast cancer patients, 6q26 is the best-defined fragile site whereas 13q13 is confined to stage II and stage III patients only. The chromosomal aberration rate/cell in breast cancer patients was found to be 0.29+/-0.13, in epithelial ovarian cancer patients 0.38+/-0.14, and in non-small-cell lung cancer 0.29+/-0.11 as compared to 0.07+/-0.03 in controls, and was found to be statistically significant. Therefore, our results indicate that these fragile sites may be the unstable sites in the genome and, hence, can be used as suitable and reliable markers for genetic predisposition to breast cancer, epithelial ovarian cancer, and in non-small-cell lung cancer.