The effect of ozone on airway relaxation mechanisms has been seldom studied. We exposed guinea pigs to ozone (0.3, 0.6 or 1.2 ppm for 4 h) and studied the in vitro tracheal responses to isoproterenol and nitroprusside, looking for differences between cervical and thoracic regions. We found that ozone did not alter responses to nitroprusside, whereas it produced a concentration-dependent decrease in the responses to isoproterenol in thoracic but not cervical tracheas. Thus, in isolated organ studies care should be taken to avoid mixing cervical and thoracic tracheal regions, at least when adrenergic responses are to be evaluated.

Animals↗

PubMedDate not supplied

Expression of APP in transgenic mice: a comparison of neuron-specific promoters.

The beta-amyloid precursor protein (APP) carries mutations in codons 717 or 670/671, which cosegregate with familial forms of Alzheimer's disease (AD). As an initial step to study the related pathogenetic mechanisms in vivo we have generated transgenic mice expressing APP with these mutations. Several neuron-specific promoters were used to drive expression of human APP cDNAs. Only the Thy-1 promoter yielded transgene expression levels comparable to or above the endogenous mouse levels. Deletion of a 121 bp sequence from the 3' untranslated region of APP appeared to increase mRNA levels. Transgene mRNA was found throughout the brain with highest levels in hippocampus and cerebral cortex. Accordingly, human APP was detected in these regions by Western blotting. Protein levels paralleled mRNA levels reaching or exceeding the amount of endogenous APP. Variable reactivity of human APP in cell bodies was shown by immunocytochemistry. Although our initial histological examinations did not reveal any alterations characteristic of AD, further studied will be required.

Aging↗

PubMedDate not supplied

Progressive age-related impairment of cognitive behavior in APP23 transgenic mice.

Transgenic APP23 mice expressing human APP(751) with the K670N/M671L mutation, were compared at ages 3, 18 or 25 months to non-transgenic littermates in passive avoidance and in a small and large Morris maze. The task in the smaller pool habituated their flight response to the platform. Impairments in passive avoidance and small pool performance in APP23 mice were clearly age-related. In the larger Morris maze APP23 mice at all ages were impaired in latency and distance swum before finding the platform. Identical performance of 18-month APP23 and controls in a visible platform condition indicates that the Morris maze performance deficit was not due to sensory, motor or motivational alterations. At age 3 months both groups initially unexpectedly avoided the visible platform, suggesting that in young mice neophobia may contribute significantly to performance in cognitive tests. In conclusion, APP23 mice exhibit both early behavioral impairment in the large Morris maze as well as impairments in passive avoidance and small pool performance that are marked only in old age.

Aging↗

PubMedDate not supplied

Distinct processing of endogenous and overexpressed recombinant presenilin 1.

The presenilin 1 (PS1) gene has been identified by positional cloning. More than 30 mutations were detected in this gene which cosegregate with Alzheimer's disease (AD). Understanding their role in disease pathogenesis requires a characterization of the PS1 protein. We have generated a set of antibodies against the three major hydrophilic domains of the deduced amino acid sequence. Analyzing cultured cells and brain samples, we identified the endogenous PS1 polypeptide as well as amino- and carboxy-terminal fragments. These metabolites were much more abundant than the full-length molecule, indicating substantial processing. Overexpression of human PS1 markedly increased the full-length polypeptide but hardly altered the amount of the metabolites. Instead, additional proteolytic fragments appeared suggesting a different metabolism of the excess PS1, which may impede studies in transfected cells. Our results indicate a tight regulation of the endogenous PS1 metabolites. PS1 and its fragments are shown to be integral membrane proteins of the endoplasmic reticulum. The mechanisms regulating the generation of the metabolites, their potential function, and role in AD remain to be studied.

Blotting, Western↗

PubMedDate not supplied

Menstrual cycle changes and intellectual performance.

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Adolescent↗

PubMedDate not supplied

The effect of menstruation on cognitive and perceptual-motor behavior: a review.

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Adolescent↗

PubMedDate not supplied

Attitudes toward menopause and aging across ethnic/racial groups.

OBJECTIVE: Attitudes have a potential role to play in the experience of menopause. The objective of this study was to examine the degree to which attitudes toward menopause and aging vary across ethnic groups and menopausal status (ie, premenopausal through postmenopausal). METHODS: More than 16,000 women were interviewed by telephone as part of the Study of Women's Health Across the Nation. They represented five ethnic/racial groups (African American, white, Chinese American, Japanese American, and Hispanic) from seven geographical sites (Boston, MA; Pittsburgh, PA; Chicago, IL; Michigan; New Jersey; and northern and southern California). RESULTS: African American women were significantly more positive in attitude. The least positive groups were the less acculturated Chinese American and Japanese American women. Menopausal status was not a consistent predictor of attitude across ethnic groups. CONCLUSIONS: In general, women's attitudes toward menopause range from neutral to positive. Ethnic groups within the United States vary slightly, but reliably, in their attitudes toward menopause and aging. Factors other than those directly associated with menopausal status seem to play a role in attitude.

Adult↗

PubMedDate not supplied

How does menstruation affect cognitive competence and psychophysiological response?

Studies of the effect of the menstrual cycle on standardized cognitive tasks, work and academic performance, perceptual-motor performance, and psychophysiological measures are reviewed. The weight of the evidence argues against a menstrual cycle effect on behavior. Studies of self report and of behaviors reflecting self confidence suggest that beliefs of menstrual debilitation remain in the population. Studies of atypical and deviant groups indicate a possible connection between behavior and the menstrual cycle.

Achievement↗

PubMedDate not supplied

The troubled teen: suicide, drug use, and running away.

The incidence and predisposing factors of suicide, drug use, and running away in adolescence are described with particular attention to teenage females. A description of common underlying themes and of steps for prevention and treatment is included.

Adolescent↗