Preliminary Findings from a Brief,Peer-Led Safer Sex Intervention for College Students Living in Residence Halls

The purpose of this study was to evaluate a single-session peer-led safer sex intervention, based on the Information-Motivation-Behavioral Skills theoretical model, for college students residing in campus residence halls. Participants (N = 108) were assigned to either an hour long control or 5-module intervention session. Compared to the control condition, the intervention increased participants’ information and women’s subjective norms about preventative behavior. Both the control and intervention sessions increased intentions to perform preventative behaviors (e.g., keep condoms available). These preliminary results suggest that this intervention is promising for increasing constructs associated with safer sexual behavior and could easily be implemented by residence hall staff.     

Divided attention, as measured by dichotic speech performance, in dementia of the Alzheimer type

To determine if impaired dichotic performance in patients with dementia of the Alzheimer type is due to the inability to divide attention or the inability to perceive degraded auditory stimuli, we measured performance on tasks of both dichotic and degraded monotic speech materials. We also examined whether perception of degraded speech stimuli presented monaurally is related to abnormalities of temporal lobe anatomy and physiology, as we have shown for dichotic performance. Although the patients were impaired on both dichotic and monotic tests, significantly greater impairment was seen on the dichotic test. Our earlier finding of a significant relation between dichotic performance and measures of anterior temporal lobe atrophy and reduced glucose metabolism was replicated, but no significant relation was found between monotic tests and measures to temporal lobe integrity. We conclude that the inability to divide attention, rather than abnormal processing of degraded stimuli per se, is reflected in poor dichotic performance in patients with dementia of the Alzheimer type, and that dichotic performance, unlike degraded monotic perception, depends directly on the integrity of temporal cortex in these patients.     

Effects of risperidone on dopamine receptor subtypes in developing rat brain.

The atypical antipsychotic risperidone is often prescribed to pediatric patients with neuropsychiatric disorders, though its effects on the developing brain remain unclear. Accordingly, we studied the effects of repeated treatment of risperidone on dopamine receptors in brain regions of juvenile rat. Levels of dopamine receptors (D(1), D(2), D(3), D(4)) in forebrain regions of juvenile rats were quantified after 3 weeks of treatment with three different doses of risperidone (0.3, 1.0 and 3.0 mg/kg) and compared findings to those in adult rats treated with risperidone (3.0 mg/kg/day) previously. Risperidone (at 1.0 and 3.0 mg/kg/day) increased levels of D(1) receptors in nucleus accumbens and caudate-putamen of juvenile, but not adult rats. Conversely, all three doses of risperidone dose-dependently increased D(2) labeling in medial prefrontal cortex and hippocampus, and D(4) receptor in nucleus accumbens, caudate-putamen and hippocampus of juvenile animals as well as in adults. Only the high dose of risperidone (3.0 mg/kg) increased D(2) receptors in caudate-putamen in both juvenile and adult brain. D(3) receptors were not altered by risperidone in any brain region at any dose or age. The findings indicate dose-dependent effects of risperidone on dopamine receptors in developing animals, and that juvenile animals are more sensitive than adults to the cerebral effects of risperidone.     

Premenstrual symptoms in black and white community samples

Premenstrual syndrome specialty clinics are reported to be almost exclusively attended by white women. This racial discrepancy has raised the question of whether there is a lower prevalence or severity of symptoms during the premenstruum among black women. The authors evaluated selected premenstrual symptoms in a representative community-based sample and found no difference in the prevalence or severity of premenstrual symptoms reported by black and white women, except for a higher prevalence of food cravings among blacks. Exploration of broader sociocultural factors may explain the observed racial difference in seeking help for premenstrual complaints.     

Angiogenesis and the blood-brain barrier in intracerebral solid and cell suspension grafts

Solid and suspension grafts of fetal central nervous system (CNS) tissue rapidly reform an intact blood-brain barrier (BBB), whereas solid grafts of peripheral nervous system (PNS) tissue fail to establish a BBB as detected by horseradish peroxide (HRP) leakage, administrated intravenously. We examined the acute changes in the BBB after grafting of fetal CNS tissue in solid and suspension form and superior cervical ganglion (SCG) and PNS tissue in the same manner. Adult rats (n = 20) received fetal (day 14–15) forebrain grafts (either solid or cell suspension) to their rostral corpus callosum bilaterally. A second group (n = 20) received SCG solid and cell suspension grafts at the same coordinates with the same technique. The animals were killed on first, third, seventh, and tenth days after grafting. Intravenous HRP (Sigma, type VI, 75 mg/5-g rat) was given 1 hour before perfusion with mixed aldehydes. Fifty-micron coronal sections were examined for the presence and location of the graft by cresyl violet and AChE staining and Mesulam's TMB method to detect HRP leakage. HRP leakage was detected in the parenchyma in all groups on the first and the third days post-transplantation indicating a disrupted BBB. No HRP reaction was seen at days 7 and 10 in groups receiving fetal forebrain tissue whether solid or cell suspension. Solid grafts of SCG consistently demonstrated HRP leakage from the first through the tenth day. However, cell suspension of SCG established a BBB by 7 days. These results suggest that within the solid grafts of CNS and PNS tissue, the permeability of the vessels is dictated by the transplanted tissue itself. When cell suspensions of the same tissue are introduced, host CNS tissue dominates as the local environment resulting in non-leaky vasculature within the graft.     

Biphasic Shocks Compared with Monophasic Damped Sine Wave Shocks for Direct Ventricular Defibrillation during Open Heart Surgery

Background: Biphasic waveform shocks are more effective than monophasic shocks for transchest ventricular defibrillation, atrial cardioversion, and defibrillation with implantable defibrillators but have not been studied for open chest, intraoperative defibrillation. This prospective, blinded, randomized clinical study compares biphasic and monophasic shock effectiveness and establishes intraoperative energy dose-response curves.

Methods: Patients undergoing cardiothoracic surgery with bypass cardioplegia were randomly assigned to the monophasic or biphasic shock group. Ventricular fibrillation occurring after aortic clamp removal was treated with escalating energies of 2, 5, 7, 10, and 20 J until defibrillation occurred. If ventricular fibrillation persisted, a 20-J crossover shock of the other waveform was used.

Results: Cumulative defibrillation success at 5 J, the primary end point of the study, was higher in the biphasic group than in the monophasic group (25 of 50 vs. 9 of 41 defibrillated;P = 0.011). In addition, the biphasic group required lower threshold energy (6.8 vs. 11.0 J;P = 0.003), less cumulative energy (12.6 vs. 23.4 J;P = 0.002), and fewer shocks (2.5 vs. 3.5;P = 0.002). Crossover-shock effectiveness did not differ between groups. Dose-response curves show biphasic shocks to have higher cumulative success rates at all energies tested.