A longitudinal study of short- and long-term activity levels in male and female spontaneously hypertensive, Wistar-Kyoto, and Sprague-Dawley rats.

The pattern of locomotor activity across development was assessed in male and female spontaneously hypertensive (SHR), Wistar-Kyoto (WKY), and Sprague-Dawley (SD) rats. Open field activity did not indicate hyperactivity in the SHR. Instead, the SD strain was generally more active. Strains and sexes did not differ in open-field locomotor response to drug challenges. When short-term (10-12 min) activity in different apparatuses was compared, the SD were most active in the open field, the SHR in the residential figure-eight maze, and the WKY in the running wheel. Long-term tests indicated hyperactivity in the SHR in the residential figure-eight maze and hypoactivity in the SD in the running wheels. Until such strain differences in activity are thoroughly defined, the use of the SHR as a model of attention-deficit/hyperactivity disorder is limited. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Misattribution of dissonance and behaviour-consistent attitude change.

Examined the prediction that people who have misattributed dissonance arousal to an external source may come to question the appropriateness of this attribution and may then be motivated to alter their attitudes. This was tested by having an experimenter discredit the plausibility of an external source after misattribution had presumably occurred. 80 female undergraduates participated in the study, with 16 of these Ss serving as controls. 64 Ss were given a pill described as having either unpleasant side effects or no side effects and then were committed to write counterattitudinal essays under high-choice conditions. Some Ss were then told that a mistake had been made and that they had actually been given the other form of the pill. As predicted, Ss who had initially been led to believe that the pill had aversive side effects but were later told that it did not manifested behavior-consistent attitude change. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Biochemical mediators of meningeal inflammatory response to group B streptococcus in the newborn piglet model

The meningeal inflammatory response to a heat-killed mutant unencapsulated strain of type III group B Streptococcus (GBS) was studied in a newborn piglet model. GBS (10(9) colony-forming unit equivalents) or saline (control) was inoculated intraventricularly. Serial cerebrospinal fluid measurements were done at baseline and over the course of the next 24 h for cytochemical changes and production of tumor necrosis factor (TNF) and prostaglandins. In separate experiments, we defined the time course of early changes during the first 6 h and dose response relationship over a range of inocula 10(6) to 10(9) colony-forming unit equivalents. The intraventricular inoculation of the heat-killed unencapsulated GBS induced marked leukocytosis and increased protein by 6 h. These changes were preceded by a several hundredfold increase in TNF (maximum at 2 h) and prostaglandins (maximum at 2-4 h). The early and sharp rise in TNF suggests its pivotal role in initiating the inflammatory cascade. The magnitude of the inflammatory response increased with increasing bacterial dose over the range studied. To study the effect of encapsulation of GBS in the induction of meningeal inflammation, we compared the response to the unencapsulated mutant strain with that to the encapsulated parent strain. The encapsulated strain produced much smaller inflammatory changes, and only with high doses of bacteria. The GBS cell wall appeared to be the primary bacterial product triggering inflammation. Intraventricular injection of the heat-killed unencapsulated GBS with exposed cell wall can serve as a valid model for studying neonatal meningitis.     

Age-related differences in the temporal and spatial regulation of matrix metalloproteinases (MMPs) in normal skin and acute cutaneous wounds of healthy humans

Despite the association of increasing age with chronic wound-healing disorders and an impaired rate of healing of acute cutaneous wounds, the role of matrix metalloproteinases (MMPs) is unknown. To determine the spatial and temporal patterns and activities of MMP-1, -2, -3 and -9, 132 healthy humans aged between 19 and 96 years underwent 4-mm punch biopsies followed by wound excision between day 1 and day 180 post-wounding. Wounds showed an age-related increase in MMP-2 and MMP-9 immunostaining from day 3; this was associated with degradation of gelatin as shown by zymograms and with increased proteinase activity as shown by azocoll assays. Distinct spatial localisations for each MMP were observed: MMP-2 was found in epidermal structures; MMP-9 was observed in inflammatory cells up to day 21; MMP-1 was localised to keratinocytes at the wound margin. Normal old skin showed pro-MMP-2 bands on zymography and increased MMP-2 immunostaining. These results indicate that: (1) intrinsic ageing is associated with the up-regulation of MMPs previously associated with chronic wound healing; (2) wound-tissue proteinases are essentially active up to day 21 postwounding; and (3) intrinsic ageing may predispose to tissue breakdown disorders because of MMP-2 up-regulation in normal skin.     

Epidemiologic profile of AIDS among Puerto Rican women in the San Juan Standard Metropolitan Statistical Area, 1981-1995

This article describes the epidemiologic profile of Puerto Rican women affected by AIDS in the San Juan Standard Metropolitan Statistical Area (SMSA). Information from AIDS cases reported to the Puerto Rico (PR) AIDS Surveillance System was analyzed. From July 1981 through June 30 1995, a cumulative total of 15,877 AIDS cases have been reported in PR, 9,838 (62%) of these cases were reported in the San Juan SMSA and 2,044 (20.8%) were women. The male to female ratio was 3.8. The predominant mode of exposure among women was heterosexual contact (48.7%), followed by intravenous drug use (40.4%). The most affected age group among women was 30 to 39 years (43.3%) followed by 20-29 (26.2%). Eighty-one percent of women were in childbearing age. A substantial increase in AIDS cases has been reported for women who revealed heterosexual contact (from 45% in 1993 to 64% in 1995), representing the fastest growing category of AIDS cases in the island. The median survival time after reporting was 16.4 months (95% CI: 15.3-17.7) for males and 22.7 months (95% CI: 19.9 and 26.9) for females. Preventive efforts must be oriented toward education and risk behavior modification primarily directed to young women.     

Identification and characterization of genes that interact with lin-12 in Caenorhabditis elegans

We identified and characterized 14 extragenic mutations that suppressed the dominant egg-laying defect of certain lin-12 gain-of-function mutations. These suppressors defined seven genes: sup-17, lag-2, sel-4, sel-5, sel-6, sel-7 and sel-8. Mutations in six of the genes are recessive suppressors, whereas the two mutations that define the seventh gene, lag-2, are semi-dominant suppressors. These suppressor mutations were able to suppress other lin-12 gain-of-function mutations. The suppressor mutations arose at a very low frequency per gene, 10-50 times below the typical loss-of-function mutation frequency. The suppressor mutations in sup-17 and lag-2 were shown to be rare non-null alleles, and we present evidence that null mutations in these two genes cause lethality. Temperature-shift studies for two suppressor genes, sup-17 and lag-2, suggest that both genes act at approximately the same time as lin-12 in specifying a cell fate. Suppressor alleles of six of these genes enhanced a temperature-sensitive loss-of-function allele of glp-1, a gene related to lin-12 in structure and function. Our analysis of these suppressors suggests that the majority of these genes are part of a shared lin-12/glp-1 signal transduction pathway, or act to regulate the expression or stability of lin-12 and glp-1.     

Suspended particles in the liquid insulation of aging power transformers

This paper examines some theoretical aspects of the relationship between the aging of oil and the deterioration of the internal insulation of the windings, and looks at some new findings that might provoke fresh consideration of the relationship between the analytical properties of liquid insulation and the dielectric properties of windings.     

Prolactin and growth hormone mRNA and protein characterization in SMtTW rat pituitary tumours

During human pregnancy, plasma corticotrophin-releasing hormone (CRH) levels rise from undetectable amounts prior to 20 weeks gestation to reach a peak near term, with an exponential rise during the final 5 weeks of gestation. Within hours of parturition plasma levels fall and rapidly return to undetectable baseline measurements. The appearance of CRH in maternal plasma has been attributed to the placental production and subsequent release into the maternal circulation of this hormone. Previous studies have shown that human placental extracts contain a CRH-like peptide and this has been reinforced by the observation of CRH mRNA in placental tissue. Initial attempts to identify the site of production using immunocytochemistry have led to conflicting results. This study attempts to clarify this situation by using a variety of highly specific anti-CRH antibodies to show the cellular expression of placental CRH. Intense CRH staining was observed in the syncytial trophoblast layer in first trimester and term chorionic villi, whilst the underlying cytotrophoblast appeared to be negative. The fetal membranes also contained CRH immunoreactivity with the cytotrophoblast cells in the chorionic membrane displaying the most intense staining. CRH immunoactivity was also observed in the amnion and in some cells in the decidua. As a model of cellular CRH expression, cytotrophoblast cells from term chorionic membrane were isolated and shown to be positive for CRH.