In vitro responses to known in vivo genotoxic agents in mouse germ cells

Genotoxic compounds have induced DNA damage in male germ cells and have been associated with adverse clinical outcomes including enhanced risks for maternal, paternal and offspring health. DNA strand breaks represent a great threat to the genomic integrity of germ cells. Such integrity is essential to maintain spermatogenesis and prevent reproduction failure. The Comet assay results revealed that the incubation of isolated germ cells with n‐ethyl‐n‐nitrosourea (ENU), 6‐mercaptopurine (6‐MP) and methyl methanesulphonate (MMS) led to increase in length of Olive tail moment and % tail DNA when compared with the untreated control cells and these effects were concentration‐dependent. All compounds were significantly genotoxic in cultured germ cells. Exposure of isolated germ cells to ENU produced the highest concentration‐related increase in both DNA damage and gene expression changes in spermatogonia. Spermatocytes were most sensitive to 6‐MP, with DNA damage and gene expression changes while spermatids were particularly susceptible to MMS. Real‐time PCR results showed that the mRNA level expression of p53 increased and bcl‐2 decreased significantly with the increasing ENU, 6‐MP and MMS concentrations in spermatogonia, spermatocytes and spermatids respectively for 24 hr. Both are gene targets for DNA damage response and apoptosis. These observations may help explain the cell alterations caused by ENU, 6‐MP and MMS in spermatogonia, spermatocytes and spermatids. Taken together, ENU, 6‐MP and MMS induced DNA damage and decreased apoptosis associated gene expression in the germ cells in vitro. Environ. Mol. Mutagen. 58:99–107, 2017. © 2017 Wiley Periodicals, Inc.     

Volumetric and surface-based 3D MRI analyses of fetal isolated mild ventriculomegaly

Diagnosis of fetal isolated mild ventriculomegaly (IMVM) is the most common brain abnormality on prenatal ultrasound. We have set to identify potential alterations in brain development specific to IMVM in tissue volume and cortical and ventricular local surface curvature derived from in utero magnetic resonance imaging (MRI). Multislice 2D T2-weighted MRI were acquired from 32 fetuses (16 IMVM, 16 controls) between 22 and 25.5 gestational weeks. The images were motion-corrected and reconstructed into 3D volumes for volumetric and curvature analyses. The brain images were automatically segmented into cortical plate, cerebral mantle, deep gray nuclei, and ventricles. Volumes were compared between IMVM and control subjects. Surfaces were extracted from the segmentations for local mean surface curvature measurement on the inner cortical plate and the ventricles. Linear models were estimated for age-related and ventricular volume-associated changes in local curvature in both the inner cortical plate and ventricles. While ventricular volume was enlarged in IMVM, all other tissue volumes were not different from the control group. Ventricles increased in curvature with age along the atrium and anterior body. Increasing ventricular volume was associated with reduced curvature over most of the ventricular surface. The cortical plate changed in curvature with age at multiple sites of primary sulcal formation. Reduced cortical folding was detected near the parieto-occipital sulcus in IMVM subjects. While tissue volume appears to be preserved in brains with IMVM, cortical folding may be affected in regions where ventricles are dilated.     

Does the Cerebellum Implement or Select Geometries? A Speculative Note

The Cerebellum - During evolution, living systems, actively interacting with their environment, developed the ability, through sensorimotor contingencies, to construct functional spaces shaping...     

Multimodal visual-somatosensory integration in saccade generation

Neurophysiological studies have demonstrated multisensory interaction effects in the neural structures involved in saccade generation when visual, auditory or somatosensory stimuli are presented bimodally. Visual-auditory interaction effects have been demonstrated in numerous behavioural studies of saccades but little is known about interaction effects involving somatosensory stimuli. The present study examined visual-somatosensory interaction effects on saccade generation using a multisensory paradigm, whereby task-irrelevant distractors appeared spatially-coincident with, or remote from the designated saccade target. Somatosensory distractors reduced the latency of saccades when presented before the visual target and the greatest facilitation effect was observed with spatially-coincident stimuli. Visual distractors spatially-coincident with a somatosensory target reduced latency (and increased peak velocity) when presented before and after the target. Visual distractors contralateral to somatosensory targets increased saccade latency and produced high error rates of saccades made to the distractor. The high error rates and latency modulation with visual distractors is consistent with a bias for visual stimuli in the saccadic system. In the visual target condition, saccade latency was modulated by a somatosensory distractor that was entirely task-irrelevant and this effect was always greatest with spatially-coincident distractors. The multisensory distractor effects are discussed in terms of saccades being programmed to the non-target modality, the early triggering of a non-spatial saccade 'when' signal, and multisensory neuronal enhancement effects.     

SARS‐CoV‐2 and guttate psoriasis: A case report and review of literature

Guttate psoriasis is a rare dermatological presentation of SARS‐CoV‐2 infection and is seen mainly in patients with an underlying disease psoriasis.     

Unemployment Rates and Trauma Admissions

In this article, we tested the hypothesis that the number and demographic characteristics of admissions to our trauma center were related to unemployment rates. The correlation study was conducted at The American College of Surgeons-verified level I trauma center in our area (New Orleans, Louisiana). It included all trauma admissions. Monthly unemployment rate data from our area were obtained from the Bureau of Labor Statistics. The hospital trauma registry supplied trauma emergency room admissions and demographic data. Mean daily trauma admissions were calculated for each month. Pearson correlations were used for statistical analysis. Over 24,000 trauma admissions occurred over a six-year period. Unemployment rates correlated with penetrating trauma admissions (r = 0.50; p < 0.001). Interestingly, unemployment rates inversely correlated with total trauma admissions (r = −0.73; p < 0.001), blunt trauma admissions (r = −0.81; p < 0.001), and ratio of blunt-to-penetrating trauma admissions (r = −0.82; p < 0.001). Higher percentage of male patients (r = 0.66; p < 0.001), percentage of African-American patients (r = 0.53; p < 0.001), and mortality (r = 0.56; p < 0.001) correlated positively with higher unemployment rates. We concluded that as unemployment rates decrease, emergency room penetrating trauma admissions decrease, while total and blunt trauma admissions increase. As the socioeconomic status (measured by unemployment rates) of the community changes, so do the demographic make-up and mortality of the trauma population. Our findings suggest that during times of economic hardships, certain population groups are at higher risk for trauma. Prevention should be aimed accordingly.