Failure of immune homeostasis -- the consequences of under and over reactivity.

The immune system is a tightly regulated network that is able to maintain a balance of immune homeostasis under normal physiological conditions. Normally, when challenged with foreign antigen, specific appropriate responses are initiated that are aimed at restoring homeostasis. However under particular circumstances, this balance is not maintained and immune responses either under or over react. Cancer is an example of a situation where the immune response can be inefficient or unresponsive, resulting in uncontrolled growth of the cancer cells. Conversely, when the immune response over-reacts, this can result in conditions such as autoimmunity or pathology following infection. Many drug therapies have been developed that aim to alleviate or prevent such immune disorders and restore immune homeostasis. This review highlights recent advances in immunotherapies, with an emphasis on specific examples in the treatment of cancer, autoimmune disease (multiple sclerosis) and viral infection (respiratory syncytial virus).

Knowledge of fetal alcohol syndrome (FAS) among natives in Northern Manitoba.

OBJECTIVE: To investigate knowledge about fetal alcohol syndrome (FAS) among Natives in northern Manitoba. A second objective was to determine if there are age or gender differences in level of knowledge. A third objective was to examine the relationship between knowledge about FAS and reported frequency of drug and alcohol use during pregnancy. METHOD: A nonrandom sample of 466 Natives from northern Manitoba was interviewed about drug and alcohol use during pregnancy and knowledge of FAS. The sample was proportionately representative of the 26 northern reserves, with an approximately equal number of male and female subjects ranging in age from 13 to 71 years. RESULTS: Northern Manitoban Natives have lower levels of FAS knowledge than the general public. Of this sample, 80% believed drinking alcohol could adversely affect the unborn baby and 36% had heard of FAS, compared to 90% and 64%, respectively, in the general U.S. population. Natives in their 20s and 30s were more knowledgeable than Natives in their 50s and 60s. Females tended to be more knowledgeable than males. Drug and alcohol use during pregnancy is high (51% of women report drinking during one or more pregnancies) and the relationship between FAS knowledge and drug use during pregnancy appears weak. Young people were the most knowledgeable about FAS but also the most likely to report having used drugs or alcohol during pregnancy. CONCLUSIONS: The low levels of knowledge about FAS among the Native population supports the need for continued education. However, the results also suggest that education by itself may be insufficient to make dramatic changes in behavior.

Human sex ratio as it relates to caloric availability.

The relationship between human sex ratios at birth and caloric availability per capita was examined across different countries. Significant positive correlations were obtained between the amount of food a country had available and the percentage of male births. Furthermore, increases or decreases in a country's caloric availability were related to corresponding changes in that country's sex ratio. These results provide evidence of adaptive sex ratio biasing in humans. The physiological mechanism by which this effect operates is probably higher mortality rates for male embryos and fetuses as a result of nutritional deficiencies and associated stressors.

PIP: Researchers applied data on caloric supply per capita and on number of female and male live births to the Pearson product-moment correlation to examine the relationship between various countries' caloric supply per capita and their sex ratio at birth. In 1979-80 and 1982-84, mean caloric availability and percentage of male births had a significant positive correlation (coeff. = .365 and .524, respectively; p .01 in both periods). Further, increases or decreases in a country's caloric availability (e.g., famine) in the 2 years following a stable 3-year-period were significantly correlated to corresponding changes in that country's percentage of male births (coeff. = .524; p .01). Even thought deviations from the mean 51.33% were minimal (SD = .55%), a small deviation equalled many 1000s of excess male or female births in countries with large populations. These findings suggested that adaptive sex ratio biasing occurs in humans. The physiological mechanism responsible for this biasing may be nutritional deficiencies during gestation causing increased mortality rates for male embryos and fetuses. The variance explained by changes in caloric supply was 28%, but several confounding factors may have reduced the extent of the correlations. For example, unavailability of birth and/or caloric supply data prevented the researchers from including many of the poorest countries. In fact, the 1980 World Tables indicated that 36% of all countries had a caloric supply per capita 100% of requirements while the countries meeting this definition in the study made up just 13% of all countries. Further, countries with caloric supplies 120% of requirements made up 54% of the countries in the study. Another concern was that food availability does not necessarily mean equal distribution or consumption of the food.