A Heme Oxygenase-1 Transducer Model of Degenerative and Developmental Brain Disorders

Heme oxygenase-1 (HO-1) is a 32 kDa protein which catalyzes the breakdown of heme to free iron, carbon monoxide and biliverdin. The Hmox1 promoter contains numerous consensus sequences that render the gene exquisitely sensitive to induction by diverse pro-oxidant and inflammatory stimuli. In “stressed” astroglia, HO-1 hyperactivity promotes mitochondrial iron sequestration and macroautophagy and may thereby contribute to the pathological iron deposition and bioenergetic failure documented in Alzheimer disease, Parkinson disease and certain neurodevelopmental conditions. Glial HO-1 expression may also impact neuroplasticity and cell survival by modulating brain sterol metabolism and the proteasomal degradation of neurotoxic proteins. The glial HO-1 response may represent a pivotal transducer of noxious environmental and endogenous stressors into patterns of neural damage and repair characteristic of many human degenerative and developmental CNS disorders.     

A stress-coping profile of opioid dependent individuals entering naltrexone treatment: A comparison with healthy controls.

Background: Stress is known to increase addiction vulnerability and risk of relapse to substance use. Purpose & Method: We compared opioid dependent individuals entering naltrexone treatment (n = 57) with healthy controls (n = 75) on measures of stress, coping, and social support and examined the relative contribution of group membership, coping, and social support to stress within the sample. Analyses of variance (ANOVA) and covariance (ANCOVA), and stepwise multiple regression were conducted. Results: Compared with controls, opioid dependent subjects reported greater stress, less use of adaptive coping, but comparable use of maladaptive/avoidant coping. No group differences were found with respect to social support. Perceived stress was predicted by group membership, low social support, and greater use of maladaptive/avoidant coping, and the prediction by social support and maladaptive/avoidant coping did not differ by group. Conclusion: Opioid dependent individuals entering naltrexone treatment experience higher levels of stress and report less use of adaptive coping strategies when compared with controls. Group membership, maladaptive/avoidant coping, and social support independently contribute to perceived stress. Findings suggest that novel treatment approaches that decrease maladaptive/avoidant coping and improve social support are important aspects of decreasing stress during early recovery from opioid addiction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences and adolescent depression.

This study investigates the role of certain psychosocial variables—sex, age, body image/self-esteem, self-consciousness, stressful life events, and the degree to which an individual identifies with the cultural stereotype of masculinity—as correlates and antecedents to depression in adolescents and explores possible intraindividual mediators of the stress–depression relationship in adolescents. A battery of self-report measures was administered to public high school students in Grades 9–12 in their classrooms at two different times 1 month apart. Female adolescents reported more depressive symptoms, self-consciousness, stressful recent events, feminine attributes, and negative body image and self-esteem; no age effects were obtained. Results suggest a model of adolescent depression in which body image/self-esteem and stressful recent events are significant contributors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assessment of depression in adolescents using the Center for Epidemiologic Studies Depression Scale.

Operating characteristics of the Center for Epidemiologic Studies Depression Scale (CES-D) were examined by using data from 4 samples of students in Grades 9–12. The CES-D was found to have good internal consistency and test–retest reliability. Dimensionality was comparable to that found for adults. Structure varied little by order of assessment (Trial 1 of Trial 2), age, or gender. Salience of items, in terms of rank order of mean item scores, was remarkably similar to that reported for college and general adult samples. With the standard cutoff score of 16 or more, half of the high school students were classified as depressed. There was a pronounced gender effect, with proportionately more women reporting depressive symptoms across the 4 samples. Although it appears that the CES-D scale may be appropriate for use with adolescents, the issues of stability of scores over time, appropriate cutoff scores, and usefulness in detecting cases of clinical depression remain unresolved. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

XeF laser performance for F2and NF3fuels

XeF laser performance has been investigated for F2versus NF3as the halogen donor (fuel). The experiments were all performed in 3 AMAGAT Ne/Xe/fuel mixtures at ambient temperature and a pump rate of 132 KW/cm³on a 1 me-beam pumped laser. The F2-based laser mixture has been shown to be recyclable, with no loss in laser output, while laser performance steadily degrades for NF2-fueled mixtures under repetitively pulsed conditions. Despite the fact that F3absorbs at the XeF wavelength, it has been demonstrated that under appropriately chosen conditions the XeF intrinsic efficiency is essentially the same (2.2 percent) for both F2and NF3fuels for deposited energy loadings up to at least 150 j/l. Absorption, gain, fuel burn-up, and fluorescence were also measured in order to better characterize the laser medium and to determine the major factors contributing to the efficiency.     

Allocation of energy inputs among the end-uses in the US petroleum and coal products industry

This paper models the allocation of energy inputs in the US petroleum and coal products industry by allocating combustible fuel and renewable energy inputs among generic end-uses, including intermediate conversions through onsite power and steam generation. This analysis, called an energy end-use model, showed that 72% of the fuel input in the US petroleum and coal products industry goes to onsite steam and power generation, whereas 28% goes directly to end-uses. Eight percent of the boiler output is used for power generation, 72% goes directly to end-uses, and 20% is waste heat. Among the end-uses, process heating is the biggest energy user with a total energy consumption of 2338 PJ, whereas machine drive is the biggest electricity consumer with a consumption of 168 PJ. This paper also provides estimates of the uncertainty of the data. The approach to create this model is applicable to all other industries for which data is available and the model is consistent with US Department of Energy data for 1998. When used in conjunction with similar models for other years, it can be used to identify the changes and trends in energy utilization even at the prime mover level of detail.     

Mitochondrial DNA variable number tandem repeats (VNTRs): utility and problems in molecular ecology

Analysis of mitochondrial (mt)DNA size polymorphism in the form of variable number tandem repeats (mtVNTRs) has become an increasingly popular methodology for addressing questions in molecular ecology. When detected by PCR, mtVNTR analysis can provide a sensitive, rapid, and cost-effective measure of genetic variability that may be exploited in studies of population differentiation and biogeography. Despite the emergence of this approach, there has been little critical evaluation of its success or utility as a practical tool. In this review, we identify problematic methodological, theoretical and interpretive factors that can influence the utility of mtVNTR analysis. The reliability of the procedure is considered in terms of both detection of alleles and scoring of intra-individual allele frequencies. While many of the potential technical problems of the technique do not raise serious practical concerns, this rapid and sensitive methodology is seriously compromised by the difficulty of reliably assessing allele frequencies, of assaying only germline tissue, and in our ignorance of the mechanisms generating mtVNTR diversity. Thus, although there is a considerable potential for mtVNTR pilot studies to assess genetic diversity, the utility of the technique to resolve broader questions in molecular ecology should be treated cautiously until such a time as the system is better understood.     

A separation principle between scheduling and admission control forbroadband switching

A framework for joint scheduling and admission control in broadband switching systems based on a principle of separation between these two levels of control is developed. It is shown that an admission control strategy can be tailored to a particular mix of traffic by using high-level information from the scheduler. This principle is presented in the context of asynchronous time-sharing (ATS) in which explicit guarantees of cell-level and call-level quality of service (QOS) are given to several traffic classes. The separation principle allows the formulation of an optimal admission control policy that maximizes the expected system utility and maintains all QOS guarantees. Several heuristic admission control policies are considered and compared with the optimal policy. The admissible load region is introduced as a means of quantifying the capacity of a switch under the QOS constraints at the cell and call levels. Numerical calculations for a single MAGNET II switching node carrying two classes of real-time traffic are used to illustrate the effects of different scheduling and admission control policies on both the expected utility and the admissable load region     

Association of apolipoprotein E epsilon2 and vasculopathy in cerebral amyloid angiopathy

Endogenous opioid peptides appear to be involved in acute behavioral effects induced by single doses of ethanol. However, its role in repeated ethanol exposure has not been studied. In the present study ethanol was given to rats at the doses of 2 and 4 g/kg by a stomach gauge for 15 days, and its effects on spontaneous motility, open-field activity, and active avoidance behavior recorded on the 3rd, the 6th and the 15th days. Then the effect of naloxone (0.5 and 2 mg/kg by intraperitoneal route) was tested against a challenge ethanol dose, administrated by oral route, on the 16th day. Control animals received tap water and saline instead of ethanol or naloxone, respectively. Both doses of ethanol induced a decrease in spontaneous motility that was antagonized by naloxone. Open-field ambulations were increased by the high dose of ethanol, low-dose lacking effect; naloxone did not modify these ethanol effects. The low dose of ethanol shortened latency time in shuttlebox, the high dose causing escape and freezing responses; none of these effects were modified by naloxone. Therefore, endogenous opioid peptides appear to play a limited role in the chronic effects of ethanol in rats; particularly its effects in tests inducing an increase in the level of anxiety were resistant to naloxone.