366 research outputs found
Degeneration and impaired regeneration of gray matter oligodendrocytes in amyotrophic lateral sclerosis.
Oligodendrocytes associate with axons to establish myelin and provide metabolic support to neurons. In the spinal cord of amyotrophic lateral sclerosis (ALS) mice, oligodendrocytes downregulate transporters that transfer glycolytic substrates to neurons and oligodendrocyte progenitors (NG2(+) cells) exhibit enhanced proliferation and differentiation, although the cause of these changes in oligodendroglia is unknown. We found extensive degeneration of gray matter oligodendrocytes in the spinal cord of SOD1 (G93A) ALS mice prior to disease onset. Although new oligodendrocytes were formed, they failed to mature, resulting in progressive demyelination. Oligodendrocyte dysfunction was also prevalent in human ALS, as gray matter demyelination and reactive changes in NG2(+) cells were observed in motor cortex and spinal cord of ALS patients. Selective removal of mutant SOD1 from oligodendroglia substantially delayed disease onset and prolonged survival in ALS mice, suggesting that ALS-linked genes enhance the vulnerability of motor neurons and accelerate disease by directly impairing the function of oligodendrocytes
Sexual behavior research on a Cohort of gay men, 1984–1990: Can we predict how men will respond to interventions?
In 1984, over 1000 gay and bisexual men volunteered to participate in both the Chicago Multicenter AIDS Cohort Study (MACS) and a companion psychosocial study, the Coping and Change Study (CCS). Participants in the semiannual Chicago MACS/CCS evaluations comprise the largest cohort of high-risk men under continuous medical, behavioral, and psychosocial observation. Chicago MACS/CCS researchers prospectively chart the sexual behavior change patterns of the cohort and relate those behavioral changes to psychosocial correlates and actual HIV infection risk. This report summarizes the behavioral natural history of the Chicago MACS/CCS cohort from 1984 to 1990, focusing on receptive anal sex practices and use patterns for alcohol and the most frequently used recreational drugs. As these are prospective observational and not controlled intervention studies, psychosocial correlates of sexual behavior change by members of the cohort are suggestive of factors influencing behavior change rather than indicative of causal relationships. However, the voluntary availability to participants in the Chicago MACS/CCS of HIV-1 antibody test results beginning in late 1985 provided the opportunity to examine whether demographic, psychosocial, or behavioral factors were indicators of sexual behavior change following disclosure and counseling about HIV-1 serostatus. Recommendations for promotion and maintenance of safer sexual behavior for the long run, and limitations in the generalizability of these findings to the much more diverse populations of men who have sex with other men conclude this article.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44099/1/10508_2005_Article_BF01541496.pd
Improvement in cognitive and psychosocial functioning and self image among adolescent inpatient suicide attempters
BACKGROUND: Psychiatric treatment of suicidal youths is often difficult and non-compliance in treatment is a significant problem. This prospective study compared characteristics and changes in cognitive functioning, self image and psychosocial functioning among 13 to 18 year-old adolescent psychiatric inpatients with suicide attempts (n = 16) and with no suicidality (n = 39) METHODS: The two-group pre-post test prospective study design included assessments by a psychiatrist, a psychologist and medical staff members as well as self-rated measures. DSM-III-R diagnoses were assigned using the SCID and thereafter transformed to DSM-IV diagnoses. Staff members assessed psychosocial functioning using the Global Assessment Scale (GAS). Cognitive performance was assessed using the Wechsler Adult Intelligence Scale, while the Offer Self-Image Questionnaire (OSIQ) was used to assess the subjects' self-image. ANCOVA with repeated measures was used to test changes from entry to discharge among the suicide attempters and non suicidal patients. Logistic regression modeling was used to assess variables associated with an improvement of 10 points or more in the GAS score. RESULTS: Among suicide attempter patients, psychosocial functioning, cognitive performance and both the psychological self and body-image improved during treatment and their treatment compliance and outcome were as good as that of the non-suicidal patients. Suicidal ideation and hopelessness declined, and psychosocial functioning improved. Changes in verbal cognitive performance were more pronounced among the suicide attempters. Having an improved body-image associated with a higher probability of improvement in psychosocial functioning while higher GAS score at entry was associated with lower probability of functional improvement in both patient groups. CONCLUSION: These findings illustrate that a multimodal treatment program seems to improve psychosocial functioning and self-image among severely disordered suicidal adolescent inpatients. There were no changes in familial relationships, possibly indicating a need for more intensive family interventions when treating suicidal youths. Multimodal inpatient treatment including an individual therapeutic relationship seems recommendable for severely impaired psychiatric inpatients tailored to the suicidal adolescent's needs
Functional Induction of the Cystine-Glutamate Exchanger System Xc- Activity in SH-SY5Y Cells by Unconjugated Bilirubin
We have previously reported that exposure of SH-SY5Y neuroblastoma cells to unconjugated bilirubin (UCB) resulted in a marked up-regulation of the mRNA encoding for the Na+ -independent cystine∶glutamate exchanger System Xc− (SLC7A11 and SLC3A2 genes). In this study we demonstrate that SH-SY5Y cells treated with UCB showed a higher cystine uptake due to a significant and specific increase in the activity of System Xc−, without the contribution of the others two cystine transporters (XAG− and GGT) reported in neurons. The total intracellular glutathione content was 2 folds higher in the cells exposed to bilirubin as compared to controls, suggesting that the internalized cystine is used for gluthathione synthesis. Interestingly, these cells were significantly less sensitive to an oxidative insult induced by hydrogen peroxide. If System Xc− is silenced the protection is lost. In conclusion, these results suggest that bilirubin can modulate the gluthathione levels in neuroblastoma cells through the induction of the System Xc−, and this renders the cell less prone to oxidative damage
Identifying the connection between Roman Conceptions of ‘Pure Air’ and Physical and Mental Health in Pompeian Gardens (c. 150 BC-AD 79): A Multi-Sensory Approach to Ancient Medicine
Different genres of Roman literature commented on the relationship between the condition of the environment and physical and mental health. They often refer to clear, pure, or good air as a beneficial aspect of the environment. Yet, unlike fetid air, they provide few descriptions of what constituted healthy air quality. Moreover, aside from pointing out the association between the environment and bodily condition, the writers also did not explain precisely how the link between the two was made. This paper utilizes a comparative study of ancient literature and the archaeological remains of Roman gardens in Pompeii: archaeobotanical samples, fresco paintings, location, and surviving features. Three questions are addressed in this study: First, how did the Romans identify and define pure? Second, how did air connect to the body? Third, what were the qualities of pure air and how did they benefit the body? Not only was inhalation a means of linking air to the body, but the two were also related through sensory perception. I argue that sight, sound, and olfaction were used to identify the qualities of pure air. Through the sensory process of identification, the beneficial properties of pure air were, in accordance with ancient perceptions of sensory function, taken into the body and affected health. Thus, sensory perception acted as the bridge between the environment and health
Технологические решения для строительства разведочной вертикальной скважины глубиной 2680 метров на газовом месторождении (ХМАО)
Технологические решения для строительства разведочной вертикальной скважины глубиной 2680 метров на газовом месторождении (ХМАО).Technological solutions for the construction of an exploration vertical well with a depth of 2680 meters at the gas field (KHMAO)
Fever as a Cause of Hypophosphatemia in Patients with Malaria
Hypophosphatemia occurs in 40 to 60% of patients with acute malaria, and in many other conditions associated with elevations of body temperature. To determine the prevalence and causes of hypophosphatemia in patients with malaria, we retrospectively studied all adults diagnosed with acute malaria during a 12-year period. To validate our findings, we analyzed a second sample of malaria patients during a subsequent 10-year period. Serum phosphorus correlated inversely with temperature (n = 59, r = −0.62; P<0.0001), such that each 1°C increase in body temperature was associated with a reduction of 0.18 mmol/L (0.56 mg/dL) in the serum phosphorus level (95% confidence interval: −0.12 to −0.24 mmol/L [−0.37 to −0.74 mg/dL] per 1°C). A similar effect was observed among 19 patients who had repeat measurements of serum phosphorus and temperature. In a multiple linear regression analysis, the relation between temperature and serum phosphorus level was independent of blood pH, PCO2, and serum levels of potassium, bicarbonate, calcium, albumin, and glucose. Our study demonstrates a strong inverse linear relation between body temperature and serum phosphorus level that was not explained by other factors known to cause hypophosphatemia. If causal, this association can account for the high prevalence of hypophosphatemia, observed in our patients and in previous studies of patients with malaria. Because hypophosphatemia has been observed in other clinical conditions characterized by fever or hyperthermia, this relation may not be unique to malaria. Elevation of body temperature should be added to the list of causes of hypophosphatemia
Bias and Evolution of the Mutationally Accessible Phenotypic Space in a Developmental System
Genetic and developmental architecture may bias the mutationally available phenotypic spectrum. Although such asymmetries in the introduction of variation may influence possible evolutionary trajectories, we lack quantitative characterization of biases in mutationally inducible phenotypic variation, their genotype-dependence, and their underlying molecular and developmental causes. Here we quantify the mutationally accessible phenotypic spectrum of the vulval developmental system using mutation accumulation (MA) lines derived from four wild isolates of the nematodes Caenorhabditis elegans and C. briggsae. The results confirm that on average, spontaneous mutations degrade developmental precision, with MA lines showing a low, yet consistently increased, proportion of developmental defects and variants. This result indicates strong purifying selection acting to maintain an invariant vulval phenotype. Both developmental system and genotype significantly bias the spectrum of mutationally inducible phenotypic variants. First, irrespective of genotype, there is a developmental bias, such that certain phenotypic variants are commonly induced by MA, while others are very rarely or never induced. Second, we found that both the degree and spectrum of mutationally accessible phenotypic variation are genotype-dependent. Overall, C. briggsae MA lines exhibited a two-fold higher decline in precision than the C. elegans MA lines. Moreover, the propensity to generate specific developmental variants depended on the genetic background. We show that such genotype-specific developmental biases are likely due to cryptic quantitative variation in activities of underlying molecular cascades. This analysis allowed us to identify the mutationally most sensitive elements of the vulval developmental system, which may indicate axes of potential evolutionary variation. Consistent with this scenario, we found that evolutionary trends in the vulval system concern the phenotypic characters that are most easily affected by mutation. This study provides an empirical assessment of developmental bias and the evolution of mutationally accessible phenotypes and supports the notion that such bias may influence the directions of evolutionary change
- …