Ivana Beatrici Manica da Cruz

Impact of psychological and endocrine factors on cytokine production of healthy elderly people

Human ageing has been associated with immunological changes including blunted T-cell responses and increased production of pro-inflammatory cytokines. Here, we investigated the role of psychological and endocrine factors in the production of pro-inflammatory cytokines (tumor necrosis factor-alpha and interleukin (IL)-6) as well as soluble IL-2Ralpha, associated with T-cell activation. Forty-six elderly subjects (60-91 yrs) and 33 young adults (20-40 yrs) were recruited accordingly the SENIEUR protocol. The emotional status was measured by structured clinical interviews. Salivary cortisol levels (9, 12 and 22 h) and serum dehydroepiandrosterone (DHEA) were assessed by radioimmunoassays. The elderly were more stressed, depressed and anxious than the young subjects. Cortisol levels were increased whereas DHEA levels were significantly reduced in the elderly. Both groups showed equivalent production of pro-inflammatory cytokines as well as soluble IL-2Ralpha. Psychological scores were positively correlated to evening cortisol levels and negatively correlated to morning DHEA levels. No relationships were noted between psychological factors and cytokines studied. However, evening cortisol levels were found positively correlated to TNF-alpha and sIL-2Ralpha levels. These data indicate that healthy ageing is associated with significant distress and activation of the hypothalamic-pituitary-adrenal axis. Our data also suggest that there are complex psychoneuroendocrine relationships involved with cytokine production during ageing.

Healthy Aging Is Associated with Unaltered Production of Immunoreactive Growth Hormone but Impaired Neuroimmunomodulation

Background: Both endocrine and immune systems are continuously remodeled during aging. Objective: Here, we investigated to what extent adrenal and somatosenescence are associated reciprocal changes in the immune system during strictly healthy aging. Methods: Forty-six elderly subjects and 33 young adults were recruited according to the health criteria of the SENIEUR protocol. Peripheral blood mononuclear cells were isolated and stimulated in vitro with lipopolysaccharide or phytohemagglutinin to assess the production of immunoreactive growth hormone (GH). Peripheral sensitivity to steroids was assessed in vitroby dexamethasone-, cortisol- or dehydroepiandrosterone (DHEA)-induced inhibition of T-cell proliferation. DHEA and GH levels were measured by radioimmunoassays. Results: Healthy elderly had lower salivary DHEA and serum GH levels (somatosenescence). They presented reduced T-cell sensitivity to dexamethasone but similar cellular sensitivities to cortisol and DHEA. Their cells produced similar levels of immunoreactive GH compared to the cells of young adults. Conclusions: These data indicate that healthy aging is associated with adrenal and somatosenescence as well as impaired neuroendocrine immunoregulation at the level of the lymphocyte. In addition, somatosenescence may not be associated with a reciprocal decline in immunoreactive GH.

Psychoneurodendocrine correlates of lymphocyte subsets during healthy ageing.

Ageing has been associated with increased cortisol levels and absolute counts of T lymphocytes with memory phenotype. Although the mechanisms underlying these changes are still unknown, it has been speculated that this could be related to a dysfunction in FAS/CD95 expression in naive or memory cells. In this study, we investigated the role of psychoneuroendocrine variables in regulating CD95 expression on lymphocyte subsets. Forty-six elderly subjects (65-91 years) and 33 young adults (20-40 years) were recruited accordingly the SENIEUR protocol. The psychological status was measured by structured clinical interviews, salivary cortisol was assessed along the day (9, 12 and 22h) and peripheral blood lymphocytes were immunophenotyped. The elderly were more stressed, depressed and anxious than the young subjects. Cortisol levels were increased in the elderly, indicating an activation of the hypothalamic-pituitary-adrenal (HPA) axis. We observed reduced counts of CD45RA+CD95+ cells in the elderly compared to young adults. The elderly subjects also showed a reduced expression of CD3 and CD62L in contrast to increased CD95 expression in CD45RA+ cells. The emotional state was positively correlated with the lymphocyte markers. Our data suggest the healthy ageing is associated with psychoneuroendocrine alterations that may be implicated in the regulation of CD95 expression on peripheral T cells.

Efeito da temperatura na maturação ovariana e longevidade de Anastrepha fraterculus (Wied.) (Diptera: Tephritidae)

Anastrepha fraterculus (Wied.) shows a populational fluctuation related to the year season in Southern Brazil. Adults cannot be colected by means of conventional methods of capture in the winter. Even with the use of special traps, a very low number of adults is caught. Two hypothesis are pointed out to explain the increase of the population at spring: a) adults migrate from neighbouring areas with temperature more favourable during winter, and b) some individuals that can survive the critical period develop a differential metabolic regulation. In this paper the second hypothesis was tested by studying the effect of four temperatures (9, 13, 20 and 25oC) on ovarian maturation and longevity of the females. Only at 25 and 20oC ovarian maturation has occurred. The life expectancy was larger in the intermediate temperatures (20 and 13oC) than in the extreme temperatures (25 and 9oC). The relation between ovarian maturation and longevity was observed at 25 and 20oC, although at 25oC the ovarian maturation was faster, but the life expectancy was lower. Therefore, the hypothesis of developmental regulation cannot be discarded as a populational mechanism in A. fraterculus for its populational increase in the months subsequent to the winter.

Genetic components affecting embryonic developmental time of Drosophila melanogaster

The developmental time of the embryonic stage of Drosophila melanogaster was 21.66% faster and 14.75% slower than controls in populations selected for fast and slow developmental speed, respectively. The genetic model with two main loci with dominant and additive effect added to maternal effect and their relevant interactions can explain 96% of the phenotypic variability in the embryonic developmental time according to 14 crossing progenies involving fast and slow flies.

Age and time exposure-related toxicity of fenthion to male and female Anastrepha fraterculus (Wied.) (Diptera: Tephritidae)

O efeito da idade, sexo e tempo de exposicao de machos e femeas de Anastrepha fraterculus (Wied.) a toxicidade do fentiom foi avaliado. A idade das moscas mostrou ser importante para o aparecimento dos primeiros sintomas de intoxicacao; machos e femeas no pico reprodutivo (30 e 60 dias de idade, respectivamente) sao menos susceptiveis ao inseticida que moscas nas demais idades (quatro e 120 dias). Nao foram detectadas diferencas de toxicidade relacionadas com o peso corporal dos insetos. O TL50, que variou de 3-7 min, mostrou serem os machos menos sensiveis que as femeas em todas as idades testadas. Adultos de ambos os sexos, com 30 dias de idade, submetidos a uma exposicao continua e descontinua ao fentiom, nao apresentaram efeito toxicologico cumulativo do inseticida. Analises estatisticas sugerem a possivel ocorrencia de um mecanismo geral de desintoxicacao (quantitativo e/ou qualitativo) relacionado com o sexo, a idade e o tempo de exposicao ao fentiom. Como a especie apresenta alta mobilidade na natureza sugere-se que estas caracteristicas biologicas e comportamentais sejam consideradas para a obtencao de resultados mais realistas.