Sexually dimorphic responses to neonatal basal forebrain lesions in mice: II. Cortical morphology

Previous studies in the mouse have shown that neonatal lesions to the cholinergic basal forebrain (nBM) areas result in transient cholinergic depletion of neocortex and precipitate altered cortical morphogenesis. Lesion-induced morphological alterations in cortex persist into adulthood and are accompanied by behavioral changes, including spatial memory deficits. The current study investigated whether neonatal nBM lesions affect male and female mice differently in adulthood. Quantitative morphometry of cortical layer width was employed to assess alterations in cytoarchitecture in neonatally nBM-lesioned and littermate control mice of both sexes following behavioral testing. Our results showed significant decreases in cortical layer IV and V widths across somato/motor cortex in neonatally nBM lesioned mice of both sexes. Sexually dimorphic responses were observed in cortical layer II/III and total cortical width, limited to the area containing the "barrel cortex" representation of the whisker hairs. In lesioned females, layer II/III and total cortical width were decreased relative to female controls, and in lesioned males, layer II/III was increased relative to controls, whereas total cortical width was unchanged. In male but not female mice we observed significant correlations between decreased widths in layer IV and V and impaired performance on a spatial memory task. The current data further support a role of developing cholinergic cortical afferents in the modulation of cortical morphogenesis and cortical circuits involved in cognitive behaviors. In addition, our observations provide further evidence for sexually dimorphic development and function in cognitive centers of the rodent brain.     

The judgement of absence in neglect

The usual way of looking at neglect is by investigating how neglect patients fail to detect that something is there. In this study, we look at how neglect patients correctly detect that something is not there. Patients with parietal lesions (11 with and 16 without neglect) and 23 control subjects indicated whether a dot target was or was not present in a geometrical display. While control subjects were consistently (and unexpectedly) faster in the no-dot than in the dot condition, the distinguishing response time pattern of right parietal patients with neglect was not--as one might expect--a relatively longer response time to left vs right targets, but a longer response time to target absence vs presence. This may be due to a serial search or, alternatively, it might result from double-checking for target absence, produced by lowered perceptual confidence. Since this "wariness" about stimulus absence seems to operate in parallel with neglect patients' denial of the deficit, we conclude that the response time pattern observed in this study could be used as a measure of subjective (un)awareness of neglect.     

Reflex human papillomavirus deoxyribonucleic acid testing in women with abnormal Papanicolaou smears

OBJECTIVE: The study examined interrelationships between sensitivity and specificity of "reflex human papillomavirus deoxyribonucleic acid testing" from liquid-based cervical cytologic specimens by means of receiver operator characteristics curves. STUDY DESIGN: A cohort study was performed on 265 women evaluated by colposcopy because of atypical squamous cells of undetermined significance or low-grade squamous intraepithelial lesion found on Papanicolaou smear. RESULTS: At a positive threshold of 0.2 pg/ml (1000 copies of human papillomavirus per test), human papillomavirus deoxyribonucleic acid testing detected 86% of women with cervical intraepithelial neoplasia and 93% of women with high-grade cervical intraepithelial neoplasia with a specificity of 30%. Decreasing the sensitivity of the human papillomavirus test to 1 pg/ml (5000 copies of human papillomavirus per test) improved the specificity of a positive result to 44% but decreased the clinical sensitivity to 78% for cervical intraepithelial neoplasia grade 2 or 3. Relationships between sensitivity and specificity were influenced by patient age and referral diagnosis. For example, limiting the analysis to only women with a referral for atypical squamous cells of undetermined significance found on Papanicolaou smear and a positive human papillomavirus test threshold of 0.5 pg/ml produced a sensitivity of 90% for cervical intraepithelial neoplasia grade 2 or 3 and a test specificity of 55%. CONCLUSION: Human papillomavirus deoxyribonucleic acid testing of residual cellular material from liquid cytologic specimens appears to be more appropriate for older women (>30 years old) and women with atypical squamous cells of undetermined significance, as opposed to low-grade squamous intraepithelial lesion, on their Papanicolaou smears.     

The therapeutic role in later life: husbands, wives and couples

The present study investigates the extent to which marital partners are different or similar in their ways of enacting the therapeutic, or supportive, role. Specifically, the article compares husbands and wives categorically as in non-dyadic studies and then as marital partners as in dyadic studies. In addition, this study, by using data from the Aging Couples Study, included only dual-earner couples so as to control for the effects of work life on marital relations. Results showed that studies of individual married men and women understate the differences between marital partners in that some wives "overbenefit" in the exchange of conjugal supports. However, husbands more often "overbenefit." Findings also indicated that the norm of reciprocity does not prevail regarding the extent of support, although it does for the types of support exchanged.     

Success Probability in Fabrication of Long, High-Strength Optical Fibers

To predict success probability in fabrication of multikilometer-length fibers as a function of on-line proof-stress level, strength data for 100-m gage lengths were used in the modified Weibull analysis. The results are discussed with regard to actual fabrication yields of 1.38-GPa (200 kpsi) on-line proof-tested chemically-vapor-deposited fibers.     

Assessing internal tobacco industry knowledge of the neurobiology of tobacco dependence.

The recent availability of internal tobacco industry documents provides a significant resource for evaluating industry understanding of the pharmacological, psychosocial, and behavioral mechanisms underlying tobacco dependence. In this study, we catalog the range of efforts undertaken by tobacco manufacturers seeking knowledge of these mechanisms. Some areas of industry research, such as cellular and molecular studies of nicotine and its effects, are widely available in the open literature. Of greater interest are internal research projects that have demonstrated direct influence on product development. These include studies of smoker psychology and behavior, evoked-response studies of tobacco-delivered nicotine, the effects of sensory perception, dose-related effects, and the development of nicotine analogs and synergists. Our findings suggest extensive industry knowledge of mechanisms that determine smoker perception and behavior, and application of this knowledge in product development, including control of sensory response, uptake of nicotine, and product effects. Independent research recently has begun to consider the contributions of tobacco product ingredients and design factors to the determination of risk, severity, and prevalence of addiction. However, the application of these findings to cessation and treatment efforts is still quite limited. We conclude that clinical research would greatly benefit from further examination of the decades of knowledge accumulated by tobacco manufacturers.