Lifespan extension and increased resistance to environmental stressors by N-Acetyl-L-Cysteine in Caenorhabditis elegans

OBJECTIVE: This study was performed to determine the effect of N-acetyl-L-cysteine, a modified sulfur-containing amino acid that acts as a strong cellular antioxidant, on the response to environmental stressors and on aging in C. elegans. METHOD: The survival of worms under oxidative stress conditions induced by paraquat was evaluated with and without in vivo N-acetyl-L-cysteine treatment. The effect of N-acetyl-L-cysteine on the response to other environmental stressors, including heat stress and ultraviolet irradiation (UV), was also monitored. To investigate the effect on aging, we examined changes in lifespan, fertility, and expression of age-related biomarkers in C. elegans after N-acetyl-L-cysteine treatment. RESULTS: Dietary N-acetyl-L-cysteine supplementation significantly increased resistance to oxidative stress, heat stress, and UV irradiation in C. elegans. In addition, N-acetyl-L-cysteine supplementation significantly extended both the mean and maximum lifespan of C. elegans. The mean lifespan was extended by up to 30.5% with 5 mM N-acetyl-L-cysteine treatment, and the maximum lifespan was increased by 8 days. N-acetyl-L-cysteine supplementation also increased the total number of progeny produced and extended the gravid period of C. elegans. The green fluorescent protein reporter assay revealed that expression of the stress-responsive genes, sod-3 and hsp-16.2, increased significantly following N-acetyl-L-cysteine treatment. CONCLUSION: N-acetyl-L-cysteine supplementation confers a longevity phenotype in C. elegans, possibly through increased resistance to environmental stressors. .

Pediatric tuberculosis in immigrants to the United Kingdom from the Indian sub-continent.

Tuberculosis (TB) is now an uncommon disease in the United Kingdom (U.K.) and its overall incidence is declining. However, the incidence of TB in immigrants from India, Pakistan, and Bangladesh (the Indian sub-continent, ISC) is much higher than in the native white population or immigrant groups from other areas, and this is so even for children of ISC ethnic origin born in the U.K. The clinical pattern of the disease also differs, extrapulmonary involvement being commoner in ISC patients than white patients. The epidemiology and management of TB in pediatric patients of ISC origin is reviewed and reasons for differences from other ethnic groups in the U.K. are discussed.

Perinatal and postneonatal mortality in England and Wales among immigrants from the Indian subcontinent.

Perinatal and postneonatal mortality among immigrants to England and Wales from India, Pakistan and Bangladesh (Asians) for the years 1982-85 showed significant differences not only between the immigrant and indigenous populations, but also among the different groups from the Indian subcontinent. Compared with the perinatal mortality rate of 10.1 per 1000 total births in UK born mothers, rates in infants of mothers born in India, Bangladesh, and Pakistan were 12.5, 14.3 and 18.8 respectively. In contrast, postneonatal mortality in infants of Indian and Bangladeshi origin (3.9 and 2.8 per 1000 live births respectively) was lower than in the indigenous population (4.1), with Pakistani infants experiencing the highest rate (6.4). Excess perinatal mortality in infants of Asian origin was apparent at most maternal ages and parities. Pakistani infants had the highest rates of perinatal and postneonatal mortality in all age, parity and birth weight groups. The Asian groups showed higher mortality from congenital anomalies in both the perinatal and the postneonatal period, the rates in Pakistani infants being almost double those in Indian and Bangladeshi infants. A significant finding was the lower rates of sudden infant death in all the groups of Asian origin.

Effect of retraining on nutrition among tribal women volunteers in Bangladesh.

Training programme on Nutrition was carried out on 42 tribal women nutrition volunteers from Rangamati, Khagrachari and Banderban districts of Chittagong Hill Tracts during July 1987 to June 1988. There were a basic training for 10 days and five retrainings of 6 days on the same group. Assessments on the level of their knowledge before and after each training were conducted by a standard questionnaire. Mean score obtained by the trainees initially was 46.28% which increased to 97.23% in the last round. Although the knowledge gain was found statistically significant in each retraining but the retention of knowledge in pre-test of each retraining was found statistically significant (P less than 0.001) upto second round (i.e. 1st retraining) and thereafter the retention was found insignificant (P greater than 0.05).