Oxidative microbial degradation of 2,4,6-trinitrotoluene via 3-methyl-4,6-dinitrocatechol

A novel pathway for biodegradation of 2,4,6-trinitrotoluene (TNT) was investigated where TNT was the sole carbon, nitrogen, and energy source. Results showed the ability of microorganismsto metabolize TNT through removal of a nitro-group, oxygenation of the aromatic ring, and production of a metabolite that is typically a precursor to oxygenolytic ring cleavage. Nitrite production was observed in active systems, and TNT degradation activity was repeatable and transferable. The metabolic intermediate, 3-methyl-4,6-dinitrocatechol, was positively identified through stable isotope mass spectrometry and tandem mass spectrometry. Experimentation with 14C-TNT showed >3% 14C-labeled CO2 in active systems after 30 d exposure to microorganisms. An increasing fraction of 14C-labeled material was associated with biomass with time, where 11.41 +/- 2.91% and 17.09 +/- 1.49% of 14C was associated with biomass in active systems after 20 and 30 d, respectively, as compared with 5.68 +/- 1.33% and 6.08 +/- 1.27% in inactive systems. Parallel degradation of TNT and production of organic metabolites and nitrite were observed in shake flasks constructed with soil from historically contaminated sites, indicating that the novel pathway identified herein is disturbed in the environment. Therefore, results presented provide evidence of a previously unreported pathway for oxidative degradation of TNT.     

Toxic and Phenotypic Effects of AAV_Cre Used to Transduce Mesencephalic Dopaminergic Neurons

A popular approach to spatiotemporally target genes using the loxP/Cre recombination system is stereotaxic microinjection of adeno-associated virus (AAV) expressing Cre recombinase (AAV_Cre) in specific neuronal structures. Here, we report that AAV_Cre microinjection in the ventral tegmental area (VTA) of ErbB4 Cyt-1-floxed (ErbB4 Cyt-1^fl/fl) mice at titers commonly used in the literature (~10¹²–10¹³ GC/mL) can have neurotoxic effects on dopaminergic neurons and elicit behavioral abnormalities. However, these effects of AAV_Cre microinjection are independent of ErbB4 Cyt-1 recombination because they are also observed in microinjected wild-type (WT) controls. Mice microinjected with AAV_Cre (10¹²–10¹³ GC/mL) exhibit reductions of tyrosine hydroxylase (TH) and dopamine transporter (DAT) expression, loss of dopaminergic neurons, and they behaviorally become hyperactive, fail to habituate in the open field and exhibit sensorimotor gating deficits compared to controls microinjected with AAV_GFP. Importantly, these AAV_Cre non-specific effects are: (1) independent of serotype, (2) occur with vectors expressing either Cre or Cre-GFP fusion protein and (3) preventable by reducing viral titers by 1000-fold (10¹⁰ GC/mL), which retains sufficient recombination activity to target floxed genes. Our studies emphasize the importance of including AAV_Cre-injected WT controls in experiments because recombination-independent effects on gene expression, neurotoxicity and behaviors could be erroneously attributed to consequences of gene ablation.     

Gain-of-Function Dynamin-2 Mutations Linked to Centronuclear Myopathy Impair Ca2+-Induced Exocytosis in Human Myoblasts

Gain-of-function mutations of dynamin-2, a mechano-GTPase that remodels membrane and actin filaments, cause centronuclear myopathy (CNM), a congenital disease that mainly affects skeletal muscle tissue. Among these mutations, the variants p.A618T and p.S619L lead to a gain of function and cause a severe neonatal phenotype. By using total internal reflection fluorescence microscopy (TIRFM) in immortalized human myoblasts expressing the pH-sensitive fluorescent protein (pHluorin) fused to the insulin-responsive aminopeptidase IRAP as a reporter of the GLUT4 vesicle trafficking, we measured single pHluorin signals to investigate how p.A618T and p.S619L mutations influence exocytosis. We show here that both dynamin-2 mutations significantly reduced the number and durations of pHluorin signals induced by 10 μM ionomycin, indicating that in addition to impairing exocytosis, they also affect the fusion pore dynamics. These mutations also disrupt the formation of actin filaments, a process that reportedly favors exocytosis. This altered exocytosis might importantly disturb the plasmalemma expression of functional proteins such as the glucose transporter GLUT4 in skeletal muscle cells, impacting the physiology of the skeletal muscle tissue and contributing to the CNM disease.     

Social competence promotion with inner-city and suburban young adolescents: Effects on social adjustment and alcohol use.

Assessed the impact of school-based social competence training on skills, social adjustment, and self-reported substance use of 282 6th and 7th graders. Training emphasized broad-based competence promotion in conjunction with domain-specific application to substance abuse prevention. The 20-session program comprised 6 units: stress management, self-esteem, problem solving, substances and health information, assertiveness, and social networks. Findings indicated positive training effects on Ss' skills in handling interpersonal problems and coping with anxiety. Teacher ratings revealed improvements in Ss' constructive conflict resolution with peers, impulse control, and popularity. Self-report ratings indicated gains in problem-solving efficacy. Results suggest some preventive impact on self-reported substance use intentions and excessive alcohol use. In general, the program was found to be beneficial for both inner-city and suburban students. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of dietary n−3 and n−6 polyunsaturated fatty acids on lipid-metabolizing enzymes in obese rat liver

This study was designed to examine whether n−3 and n−6 polyunsaturated fatty acids at a very low dietary level (about 0.2%) would alter liver activities in respect to fatty acid oxidation. Obese Zucker rats were used because of their low level of fatty acid oxidation, which would make increases easier to detect. Zucker rats were fed diets containing different oil mixtures (5%, w/w) with the same ratio of n−6/n−3 fatty acids supplied either as fish oil or arachidonic acid concentrate. Decreased hepatic triacylglycerol levels were observed only with the diet containing fish oil. In mitochondrial outer membranes, which support carnitine palmitoyltransferase I activity, cholesterol content was similar for all diets, while the percentage of 22∶6n−3 and 20∶4n−6 in phospholipids was enhanced about by 6 and 3% with the diets containing fish oil and arachidonic acid, respectively. With the fish oil diet, the only difference found in activities related to fatty acid oxidation was the lower sensitivity of carnitine palmitoyltransferase I to malonyl-CoA inhibition. With the diet containing arachidonic acid, peroxisomal fatty acid oxidation and carnitine palmitoyltransferase I activity were markedly depressed. Compared with the control diet, the diets enriched in fish oil and in arachidonic acid gave rise to a higher specific activity of aryl-ester hydrolase in microsomal fractions. We suggest that slight changes in composition of n−3 or n−6 polyunsaturated fatty acids in mitochondrial outer membranes may alter carnitine palmitoyltransferase I activity.     

The effects of emotional content on reality-monitoring performance in young and older adults.

Reality monitoring refers to a person's ability to distinguish between perceived and imagined events. Prior research has demonstrated that young adults show a reality-monitoring advantage for negative arousing information as compared with neutral information. The present research examined whether this reality-monitoring benefit extends to positive information in young adults and whether older adults show a reality-monitoring advantage for emotional information of either valence. Two studies revealed no evidence for a reality-monitoring advantage for positive information; in both age groups, the reality-monitoring advantage existed only for negative information. Older adults were, however, more likely to remember that a positive item had been included on a study list than they were to remember that a nonemotional item had been studied. Young adults did not show this mnemonic enhancement for positive information. These results indicate that although older adults may show some mnemonic benefits for positive information (i.e., an enhanced ability to remember that a positive item was studied), they do not always show enhanced memory for source-specifying details of a positive item's presentation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social housing investment: Housing policy and finance in the UK and the Netherlands, 1970–1992

Levels of social housing investment in the UK and the Netherlands are considered for the period 1970–1992. The changing housing policies and the developing structures of social housing finance are analysed. These factors have contributed to the decline in social housing construction in the UK and the Netherlands. In particular, the desire of governments in both countries to cut public capital expenditure on housing and increase the role of private, capital in new construction reduced the output during the 1980s. In the UK, a tight monetarist policy was adopted with the aim of keeping inflation down. This can be seen as a major cause of declining levels of public expenditure on housing production. In the Netherlands, a more significant role, compared to the UK, seems to have been played by developments on the housing market, especially the real estate crisis in 1978–1982. In both countries, the outlook for investment in social housing is gloomy Hugo Priemus hold the chair in housing at Delft Unviersity of Technology, and he is managing director of OTB Research Institute for Policy and Technology Jacqueline Smith is research assistant at the School of the Built Environment, De Montfort University, Leicester, (UK). Both cooperate in the Centre for Comparative Housing Research, a joint venture between the School of the Built Environment and OTB.