The relationship between type 2 theta and behavior

Although there is extensive literature on the correlation between Type 1 theta activity in the hippocampus and behavior, little is known about the behavioral correlates of "Type 2" (immobility) theta. In the present study, guinea pigs were exposed to three high "arousal" situations. These situations produced reliable trains of "Type 2" theta. Atropine sulfate abolished "arousal" and Type 2 theta. In the second study, we determined whether the Type 2 theta response was produced by specific stimuli or by a generalized sensitization to incoming sensory stimuli created by the testing situation. In this study, a stimulus which had not previously elicited Type 2 theta was presented a second time after a presentation of a stimulus which did elicit Type 2 theta. The previously neutral stimulus now elicited Type 2 theta. These results were interpreted within an "arousal" theory framework.     

Working With Parents Through a Devastating Experience-The Birth of a Mongoloid Child

The author believes that professional advice given the parents of a mongoloid infant determines their initial decision on institutionalization. Multidisciplinary counseling by the health team can help parents decide on a course of action that will prove satisfactory in the long run. Consultation should include health t e r n efforts to help parents work through the mourning process and presentation of a) an objective, comprehensive view of the child's condition, b) information on integrating a mongoloid into the family unit, and c) outside resources available to the parents. Deliberation with the parents to help them reach their own decision is essential.     

Diseases of comfort: primary cause of death in the 22nd century

CONTEXT: The world has started to feel the impact of a global chronic disease epidemic, which is putting pressure on our health care systems. If uncurbed, a new generation of "diseases of comfort" (such as those chronic diseases caused by obesity and physical inactivity) will become a major public health problem in this and the next century. OBJECTIVE: To describe the concept, causes, and prevention and control strategies of diseases of comfort. METHODS: Brokered by a senior research scientist specialised in knowledge translation, a chair, a president, and a past president of national public health associations contributed their views on the subject. RESULTS: Diseases of comfort have emerged as a price of living in a modern society. It is inevitable that these diseases will become more common and more disabling if human "progress" and civilisation continue toward better (more comfortable) living, without necessarily considering their effects on health. Modern technology must be combined with education, legislation, intersectoral action, and community involvement to create built and social environments that encourage, and make easy, walking, physical activity, and nutritious food choices, to reduce the health damaging effects of modern society for all citizens and not only the few. CONCLUSIONS: Public health needs to be more passionate about the health issues caused by human progress and adopt a health promotion stance, challenging the assumptions behind the notion of social "progress" that is giving rise to the burden of chronic disease and developing the skills to create more health promoting societies in which individual health thrives.     

Difficulties in Immunohaematology : The Weak D Antigen

Background

The Rh blood system is one of the most polymorphic and immunogenic systems known to humans. The expression of Rh blood group antigen is complex. The Rh D antigen is the most important of the antigens that constitute the Rh antigen system. In most cases, D antigen can easily be detected. However, due to variability of expression, weak forms antigen are encountered. The reactivity of weak D with antisera is variable and presents as a problem in blood banking.

Methods

A retrospective analysis for a five-year period was done. Blood samples that were negative for Rh D by immediate spin tube method were tested for weak D antigen by additional lab tests.

Result

Of 34932 serial Rh grouping tests done in our Blood Bank, the incidence of weak D Rh antigen was 0.189%. All these were confirmed by the antiglobulin test.

Conclusion

These patients present as a problem for the blood banker and a curiosity to the clinician. Although uncommon, all health care workers should be aware of this entity to avoid anti D alloimmunisation.Key Words: Weak D, Rh Blood Group     

Hypothalamic Y2 receptors regulate bone formation

Neuropeptide Y (NPY) is a downstream modulator of leptin action, possibly at the level of the arcuate nucleus where NPY neurons are known to express both leptin receptors and Y2 receptors. In addition to the well-described role of NPY and leptin in energy balance and obesity, intracerebroventricular administration of NPY or leptin also causes bone loss. Here we show that Y2 receptor-deficient mice have a twofold increase in trabecular bone volume as well as greater trabecular number and thickness compared with control mice. We also demonstrate that central Y2 receptors are crucial for this process, since selective deletion of hypothalamic Y2 receptors in mature conditional Y2 knockout mice results in an identical increase in trabecular bone volume within 5 weeks. This hypothalamus-specific Y2 receptor deletion stimulates osteoblast activity and increases the rate of bone mineralization and formation, with no effect on osteoblast or osteoclast surface measurements. The lack of any changes in plasma total calcium, leptinemia, or hypothalamo-pituitary-corticotropic, -thyrotropic, -somatotropic, or -gonadotropic output suggests that Y2 receptors do not modulate bone formation by humoral mechanisms, and that alteration of autonomic function through hypothalamic Y2 receptors may play a key role in a major central regulatory circuit of bone formation.     

Y4 receptor knockout rescues fertility in ob/ob mice

Hypothalamic neuropeptide Y (NPY) has been implicated in the regulation of energy balance and reproduction, and chronically elevated NPY levels in the hypothalamus are associated with obesity and reduced reproductive function. However, it is not known which one of the five cloned Y receptors mediates these effects. Here we show that crossing the Y4 receptor knockout mouse (Y4(-/-)) onto the ob/ob background restores the reduced plasma testosterone levels of ob/ob mice as well as the reduced testis and seminal vesicle size and morphology to control values. Fertility in the sterile ob/ob mice was greatly improved by Y4 receptor deletion, with 100% of male and 50% of female Y4(-/-),ob/ob double knockout mice producing live offspring. Development of the mammary ducts and lobuloalveoli was significantly enhanced in pregnant Y4(-/-) and Y4(-/-),ob/ob females. Consistent with the improved fertility and enhanced mammary gland development, gonadotropin releasing hormone (GnRH) expression was significantly increased in Y4(-/-) and Y4(-/-),ob/ob animals. Y4(-/-) mice displayed lower body weight and reduced white adipose tissue mass accompanied by increased plasma levels of pancreatic polypeptide (PP). However, Y4 deficiency had no beneficial effects to reduce body weight or excessive adiposity of ob/ob mice. These data suggest that central Y4 receptor signaling specifically inhibits reproductive function under conditions of elevated central NPY-ergic tonus.