On separating processes of event categorization, task preparation, and mental rotation proper in a handedness recognition task.

We investigated the nature of event-related potential (ERP) effects in a handedness recognition task requiring mental rotation. Thirty subjects were tested with rotated and sometimes reflected alphanumeric characters while ERPs were recorded from 18 electrodes. On each trial, a cue provided valid information about the angular displacement of the following probe. This design allowed a distinction between three processing episodes: evaluation of the difficulty of the forthcoming task, preparation for the task, and the mental rotation task itself. The three episodes were accompanied by distinct ERP effects having distinct polarities, a different rank order of amplitudes for different probe orientations, and a different topography. These data confirm previous findings showing that mental rotation is accompanied by a parietal negativity. However, they also suggest that the rotation-related negativity found after tilted stimuli in standard mental rotation tasks is most likely overlapping with another, simultaneously triggered ERP effect functionally related to an evaluation of task difficulty.     

Use of adenovirus protein IX (pIX) to display large polypeptides on the virion--generation of fluorescent virus through the incorporation of pIX-GFP.

The adenovirus (Ad) protein IX (pIX) is a minor component of the Ad capsid and associates with the hexons that make up the facets of the icosahedron. In this study, we investigated whether a large protein tag could be fused to pIX without compromising the Ad vector itself. As proof-of-principle, we generated a pIX-green fluorescent protein (GFP) fusion protein. We show that a virus encoding the pIX-GFP can be generated and that pIX-GFP fusion protein was incorporated into the Ad capsid as efficiently as native pIX. In tissue culture, translocation of Ad/pIX-GFP from the outside of the cell to the nucleus could be followed using fluorescence microscopy, and the timing of migration to the nucleus was similar to that previously reported for Ad. We also could track the virus after injection into the tibialis anterior muscle of mice. Shortly after injection, the majority of the Ad/pIX-GFP accumulated in pockets adjacent to the muscle fibers, with some migration of the virus between fibers. Our ability to attach GFP to the Ad virion, through fusion to pIX, provides a valuable tool for virus tracking in vitro and in vivo. Moreover, our data indicate that pIX can be used as a platform to anchor proteins to the Ad capsid, such as large ligands for cell-type-specific targeting of the vector.     

Defective membrane systems in dystrophic skeletal muscle of the UM-X7.1 strain of genetically myopathic hamster.

1. The function of mitochondria, sarcotubular membranes (heavy microsomes), sarcolemma and myofibrils from the hind-leg skeletal muscle of about 60- and 150-day-old normal and myopathic (UM-X7.1) hamsters was examined. 2. The mitochondrial calcium uptake as well as mitochondrial phosphorylation and respiratory rates were lower in 60-day-old myopathic skeletal muscle, unlike 150-day-old myopathic animals, when pyruvate-malate and glutamate-malate were used as substrates. However, mitochondria from 150-day-old myopathic animals showed depressed glutamate-dependent respiratory and phosphorylation rates and succinate-supported initial rate of calcium uptake. 3. The microsomal calcium-uptake, but not calcium-binding, and Ca2+-stimulated adenosine triphosphatase (ATPase) activity of the 150-day-old myopathic skeletal muscle were lower than the control values. Although microsomal calcium-binding, calcium-uptake and ATPase activities of the 60-day-old myopathic muscle were not depressed significantly, the initial rate of calcium uptake was less than the control. 4. The sarcolemmal Ca2+-ATPase, but not Mg2+-ATPase or Na+ +K+-ATPase, activity was higher in 60-day-old myopathic muscle whereas the activities of all these enzymes from 150-day-old myopathic animals were higher than the control. On the other hand, the Na+ +K+-ATPase activities from 60- and 150-day-old myopathic animals were inhibited by ouabain to a lesser extent in comparison with the respective control values. 5. The myofibrillar Ca2+-ATPase and Mg2+-ATPase activities as well as inhibition of Mg2+-ATPase due to Na+ and K+ in myopathic muscle were no different from the control values. 6. The results reported here give further support to the view that different membrane systems of the dystrophic muscle are defective.     

Prognostic value of blood and bone marrow T-colony-forming cells (T-CFC) in patients with lymphadenopathy syndrome (LAS)

The in vitro proliferation capacity of peripheral blood committed T-cell precursors (T-CFC) from LAS patients was studied in order to define whether this parameter could be associated with transition to AIDS. In all patients a significantly (P less than 0.0001) decreased plating efficiency was detected. However, the lowest T-cell colony growth (less than 50 colonies/5 x 10(4) cells) was observed in the 23 patients who subsequently developed the full-blown disease within 150-570 days. Conversely, only one patient (n = 107) whose T-CFC generated greater than 50 colonies/5 x 10(4) cells developed AIDS after a mean follow-up of 867 days (range 120-1260 days). T-CFC from these patients displayed an impaired in vitro differentiation and self-renewal capacity which was independent of the clinical evolution of the disease. In 5 out of 12 AIDS patients, adherent cell-depletion of peripheral blood mononuclear cells (PBMC) enhanced the plating efficiency. Moreover, patients' but not normal adherent cells could inhibit normal T-cell colony growth in a dose-dependent manner. Media conditioned by patients' unstimulated adherent cells (LCM-A+p) also inhibited normal T-cell colony formation. In addition, LCM-A+p were capable of inhibiting interleukin 2-receptor (IL 2-R) expression and interleukin 2 (IL 2) production by normal mitogen-stimulated T-cells. These findings suggest that adherent cell-derived inhibitory activity(ies) could be responsible for the low T-cell colony formation observed in some AIDS patients.     

Dynamic changes in CREB phosphorylation and neuroadaptive gene expression in area V1 of adult monkeys after monocular enucleation

Our understanding of the molecular events that emerge after change in sensory input remains elusive, especially with regard to mature area V1. Here, we characterized P-CREB expression in area V1 of monkeys at multiple time-points after monocular enucleation (ME) to assess the possible contribution of CREB in visually deprived neocortex. Immunoblot assays and immunostainings showed that P-CREB is dynamically regulated in adult area V1, reaching a peak level between 5 and 30 days after ME, and becoming reduced at the 90-day post-ME time-point. This striking temporal increase in P-CREB level was paralleled by a concomitant increase of two CREB-regulated pro-survival effectors, namely Bcl-2 and Bcl-w. We present our results in the context of recent advances about adult visual neocortex and propose that ME induces a multifaceted CREB-mediated response that favors intrinsic stability of neurons and facilitates mature cortical networks to reorganize over a prolonged period.     

Postpartum Haemorrhage and Eclampsia: Differences in Knowledge and Care-seeking Behaviour in Two Districts of Bangladesh

In high- and low-performing districts of Bangladesh, the study explored the demand-side of maternal healthcare by looking at differences in perceived knowledge and care-seeking behaviours of women in relation to postpartum haemorrhage or eclampsia. Haemorrhage and eclampsia are two major causes of maternal mortality in Bangladesh. The study was conducted during July 2006–December 2007. Both postpartum bleeding and eclampsia were recognized by women of different age-groups as severe and life-threatening obstetric complications. However, a gap existed between perception and actual care-seeking behaviours which could contribute to the high rate of maternal deaths associated with these conditions. There were differences in care-seeking practices among women in the two different areas of Bangladesh, which may reflect sociocultural differences, disparities in economic and educational opportunities, and a discrimination in the availability of care.Key words: Beliefs, Care-seeking behaviour, Maternal mortality, Postpartum haemorrhage, Eclampsia, Qualitative research, Bangladesh