Inactivation and degradation of CuZn-SOD by active oxygen species in wheat chloroplasts exposed to photooxidative stress

Substantial increases in the relative and absolute number of older persons in our society pose a challenge for biology, social and behavioral science, and medicine. Successful aging is multidimensional, encompassing the avoidance of disease and disability, the maintenance of high physical and cognitive function, and sustained engagement in social and productive activities. Research has identified factors predictive of success in these critical domains. The stage is set for intervention studies to enhance the proportion of our population aging successfully.     

Evidence for association and genetic linkage of the angiotensin-converting enzyme locus with hypertension and blood pressure in men but not women in the Framingham Heart Study

BACKGROUND: There is controversy regarding the association of the angiotensin-converting enzyme deletion-insertion (ACE D/I) polymorphism with systemic hypertension and with blood pressure. We investigated these relations in a large population-based sample of men and women by using association and linkage analyses. METHODS AND RESULTS: The study sample consisted of 3095 participants in the Framingham Heart Study. Blood pressure measurements were obtained at regular examinations. The ACE D/I polymorphism was identified by using a polymerase chain reaction assay. In logistic regression analysis, the adjusted odds ratios for hypertension among men for the DD and DI genotypes were 1.59 (95% confidence interval [CI], 1.13 to 2.23) and 1.18 (95% CI, 0.87 to 1.62), respectively, versus II (chi2 P=.02). In women, adjusted odds ratios for the DD and DI genotypes were 1.00 (95% CI, 0.70 to 1.44) and 0.78 (95% CI, 0.56 to 1.09), respectively (P=.14). In linear regression analysis, there was an association of the ACE DD genotype with increased diastolic blood pressure in men (age-adjusted P=.03, multivariate-adjusted P=.14) but not women. Quantitative trait linkage analyses in 1044 pairs of siblings, by using both ACE D/I and a nearby microsatellite polymorphism of the human growth hormone gene, supported a role of the ACE locus in influencing blood pressure in men but not in women. CONCLUSIONS: In our large, population-based sample, there is evidence for association and genetic linkage of the ACE locus with hypertension and with diastolic blood pressure in men but not women. Our data support the hypothesis that ACE, or a nearby gene, is a sex-specific candidate gene for hypertension. Confirmatory studies in other large population-based samples are warranted.     

Proxy informant reliability and bias in epidemiological research: analysis of a screening questionnaire for mental disorders

OBJECTIVES: To evaluate the reliability, magnitude and direction of the resulting bias in the application of a screening instrument for mental disorders by considering proxy informants in comparison to primary informants. METHODS: Data are taken from a general morbidity community-based survey carried out in 520 randomly selected households of an industrial area of the Metropolitan Region of Salvador, the capital of Bahia state, Brazil. During the pilot phase, the first 70 families of the total sample were asked to participate in the evaluation of research instruments. The Questionnaire of Adult Psychiatric Morbidity, QAPM, consists of 44 questions about psychiatric symptoms widely used in Brazil. The husbands and wives of the selected families answered QAPM questions regarding themselves and their respective partners. One family refused to participate. The Kappa index was estimated for each QAPM question. To assess the magnitude and direction of bias, the proportional variation of prevalence was estimated from proxy and primary respondents. Each informant was analyzed as a primary informant when answering about his/her own symptoms and as a proxy informant when answering those about his/her partner. RESULTS: Proxy informants as compared to primary informants show weak reliability, as measured by the Kappa Index, particularly when husbands reported on their wives' symptoms. An overall underestimation of prevalence estimates was found, which reveals the potential negative bias with the use of proxy informants for psychological symptoms. No bias was found for only two questions (lack of appetite and globus hystericus) when women were taken as proxy informants for their husbands. In addition, departures of proxy informants from primary informant-based estimates were greater among men than to women. CONCLUSIONS: Proxy informants underestimate the occurrence of psychological symptoms in this community-based study. When the feasibility of a research project, based on the QAPM depends on the use of proxies, wives may be recommended as better informants than their husbands.     

Proliferative events in the cerebral ventricular zone

The neocortex varies vastly in size and complexity yet its cytology, laminar architecture, and general plan of cytoarchitectonic organization are closely similar across mammalian species. These similarities of structure and organization emerge in the course of a closely similarly developmental history. Thus, the neocortex in all species arises in the course of a discrete neuronogenetic interval (NI) from a pseudostratified ventricular epithelium (PVE) located in the margin of the developing cerebral wall. Once their terminal cell division in this epithelium has been completed the young neurons migrate across the cerebral wall to the neocortex where they grow, differentiate, and become synaptically incorporated into cerebral neural systems. The neurons forming the deepest cortical layers are the earliest to be formed while progressively later formed neurons arise at progressively later times in development. In experiments in mice, we have determined that it is the relation of total cell cycle number, occurring in the course of the NI, to the cell cycle output function, Q, which is regulatory to the duration of NI and to the rate of neuron production. Cell cycle number appears largely to be regulated by progression in the length of the G1 phase of the cycle. We propose that regulation is mediated by cell external substances, acting upon the proliferating cell during G1 phase.     

Strain differences in susceptibility of female mice to 1,2-dimethylhydrazine

C3H, CBA, C57BL/6j, (CBA x C57BL/6j)F1, BALB/c, DBA/2, C3HA and AKR female mice were treated with 25 weekly s.c. injections of a solution of 1,2-dimethylhydrazine (DMH) in water at a dose level of 8 mg/kg body weight. BALB/c mice appeared to be most sensitive to the induction of epithelial colorectal (93.3%) and anal tumours by DMH. There was, however, a dissociation between the severity of the macroscopical tumour lesions in the colon of BALB/c mice and their relatively weak tendency to infiltrative growth. C3HA mice were more resistant to the induction of intestinal tumours (30.9%) but the tumours showed a deep invasion into the intestinal wall. There was no correlation between the strains and within a given strain between the development of colorectal and anal neoplasms. C3H and CBA mice strains developed a high incidence of uterine sarcomas (37.5 and 40.7%, respectively) which were not found at all in BALB/c, DBA/2 and C3HA mice and which appeared in C57BL/6j and AKR mice at low frequency (2.7 and 7.7%, respectively). C57BL/6j, BALB/c, DBA/2 and C3HA mice developed haemorrhagic lesions of the ovaries (35.1, 46.7, 62.9 and 85.7%, respectively). These lesions, which led to peritoneal haemorrhage, were one of the main causes of death in C3HA and DBA/2 strains. It seems that, with the exception of AKR mice, an inverse relationship exists between the occurrence of haemorrhagic ovarian lesions and development of uterine sarcomas in female mice treated with DMH.     

Domestication-related behavior in sheep

Chronic nicotine exposure in the rat produces a characteristic increase in neuronal nicotinic binding sites in many brain regions. The conventional method for inducing such increases utilizes twice daily subcutaneous injections of a near maximal, sub-convulsive dose of nicotine. Alternatively, nicotine may be chronically infused via an osmotic mini-pump. However, little is known about how administration of nicotine by chronic infusion compares to multiple injections in producing nicotinic receptor upregulation. This study used [3H]-epibatidine, a high potency neuronal nicotinic agonist radioligand, to compare the increases in receptor levels in rat brain, spinal cord and trigeminal ganglion tissues following chronic nicotine administration via either twice daily injections (2 mg/kg s.c.) or an osmotic mini-pump (1 mg/kg/hr) for 10 days. All central and peripheral nervous system tissues examined demonstrated significant neuronal nicotinic receptor up-regulation following chronic infusion of nicotine. Only the cerebral cortex and hippocampus displayed significant up-regulation following nicotine administration by injections. Moreover, in all tissues studied, the receptor levels measured were significantly higher in the animals that received nicotine by chronic infusion compared with multiple injections. These data indicate that chronic infusion of nicotine is a convenient and efficacious alternative to multiple injections for producing neuronal nicotinic receptor up-regulation in both central and peripheral nervous tissues.     

The effect of antiemetics and reduced radiation fields on acute gastrointestinal morbidity of adjuvant radiotherapy in stage I seminoma of the testis: a randomized pilot study

OBJECTIVE: To assess the long term effects of weight loss with and without additional aerobic and weight training exercises on exercise tolerance and cardiorespiratory fitness in obese women. EXPERIMENTAL DESIGN: Randomized prospective study for an approximately one-year community setting. PATIENTS: 31 healthy obese women volunteers (age 42.8 yrs +/- 6 SD) recruited by community advertisement. INTERVENTION: All subjects underwent a weight loss program consisting of low calorie diet and behavior therapy for a minimum of 46 weeks. They were randomly assigned to one of the four groups. Group A: diet alone, Group B: diet plus aerobic exercise program in a supervised group setting, Group C: Diet plus weight training and Group D: diet plus weight training plus aerobic exercise program. MEASURES: Exercise time (Tex) peak sustained workload (Wp), peak oxygen consumption (VO2), oxygen pulse and the rate of change of VO2 on recovery (VO2rec) were measured at the beginning and after 47.5 weeks +/- 1.5 SD, of the program. RESULTS: All subjects lost weight and achieved increased Tex and lowered resting VO2. VO2 peak and VO2 peak kg-1 increase in Groups B and D only. O2 pulse and VO2rec improved in group D. Improvements in exercise time correlated significantly with initial exercise time and weight loss. CONCLUSIONS: Weight loss increase Tex irrespective of participation in an exercise program. However, evidence of improved aerobic fitness occurred only in groups performing aerobic exercise.