Posterior longitudinal ligament ossification myelopathy and hypothyroidism

Two elderly white women with a long history of hypothyroidism and myelopathy showed ossification in posterior longitudinal ligament at their cervical spine. Case histories are presented and the reported association of PLLO with other conditions discussed.     

Functional genomic screen of human stem cell differentiation reveals pathways involved in neurodevelopment and neurodegeneration

Human embryonic stem cells (hESCs) can be induced and differentiated to form a relatively homogeneous population of neuronal precursors in vitro. We have used this system to screen for genes necessary for neural lineage development by using a pooled human short hairpin RNA (shRNA) library screen and massively parallel sequencing. We confirmed known genes and identified several unpredicted genes with interrelated functions that were specifically required for the formation or survival of neuronal progenitor cells without interfering with the self-renewal capacity of undifferentiated hESCs. Among these are several genes that have been implicated in various neurodevelopmental disorders (i.e., brain malformations, mental retardation, and autism). Unexpectedly, a set of genes mutated in late-onset neurodegenerative disorders and with roles in the formation of RNA granules were also found to interfere with neuronal progenitor cell formation, suggesting their functional relevance in early neurogenesis. This study advances the feasibility and utility of using pooled shRNA libraries in combination with next-generation sequencing for a high-throughput, unbiased functional genomic screen. Our approach can also be used with patient-specific human-induced pluripotent stem cell-derived neural models to obtain unparalleled insights into developmental and degenerative processes in neurological or neuropsychiatric disorders with monogenic or complex inheritance.     

Posterior spinal cord block: a dosimetric study

To determine the optimal width of a midline posterior spinal block (MPSB) (to avoid delivering too great a dose to the cord and too small a dose to adjacent tissue), the authors determined with magnetic resonance (MR) imaging normal ranges of cord depth and width and correlated them with film dosimetric data. In 59 randomly selected patients there was a wide range for both depth and width. The average depths of the anterior and posterior surfaces of the cord were 6.7 cm +/- 1.4 and 5.4 cm +/- 1.3, respectively. The average cord width was 1.6 cm +/- 0.4. Optimal cord block width as a function of cord width was determined for a 6-MV photon beam. The optimal cord block width at the surface (half-value layer [HVL] thickness = 6) varied from 1.5 to 3.0 cm for cord widths of 0.8-2.4 cm, which correspond to two standard deviations from the average. There was no significant dependence on depth of the cord. For optimal treatment outcome, the MPSB width may have to be determined for each patient individually.     

The dystrophin gene and cognitive function in the general population

The aim of our study is to investigate whether single-nucleotide dystrophin gene (DMD) variants associate with variability in cognitive functions in healthy populations. The study included 1240 participants from the Erasmus Rucphen family (ERF) study and 1464 individuals from the Rotterdam Study (RS). The participants whose exomes were sequenced and who were assessed for various cognitive traits were included in the analysis. To determine the association between DMD variants and cognitive ability, linear (mixed) modeling with adjustment for age, sex and education was used. Moreover, Sequence Kernel Association Test (SKAT) was used to test the overall association of the rare genetic variants present in the DMD with cognitive traits. Although no DMD variant surpassed the prespecified significance threshold (P<1 × 10⁻⁴), rs147546024:A>G showed strong association (β=1.786, P-value=2.56 × 10⁻⁴) with block-design test in the ERF study, while another variant rs1800273:G>A showed suggestive association (β=−0.465, P-value=0.002) with Mini-Mental State Examination test in the RS. Both variants are highly conserved, although rs147546024:A>G is an intronic variant, whereas rs1800273:G>A is a missense variant in the DMD which has a predicted damaging effect on the protein. Further gene-based analysis of DMD revealed suggestive association (P-values=0.087 and 0.074) with general cognitive ability in both cohorts. In conclusion, both single variant and gene-based analyses suggest the existence of variants in the DMD which may affect cognitive functioning in the general populations.     

The association of PTSD with physical and mental health functioning and disability (VA Cooperative Study #569: the course and consequences of posttraumatic stress disorder in Vietnam-era Veteran twins)

Purpose

To assess the relationship of posttraumatic stress disorder (PTSD) with health functioning and disability in Vietnam-era Veterans.

Methods

A cross-sectional study of functioning and disability in male Vietnam-era Veteran twins. PTSD was measured by the Composite International Diagnostic Interview; health functioning and disability were assessed using the Veterans RAND 36-Item Health Survey (VR-36) and the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0). All data collection took place between 2010 and 2012.

Results

Average age of the 5,574 participating Veterans (2,102 Vietnam theater and 3,472 non-theater) was 61.0 years. Veterans with PTSD had poorer health functioning across all domains of VR-36 and increased disability for all subscales of WHODAS 2.0 (all p < .001) compared with Veterans without PTSD. Veterans with PTSD were in poorer overall health on the VR-36 physical composite summary (PCS) (effect size = 0.31 in theater and 0.47 in non-theater Veterans; p < .001 for both) and mental composite summary (MCS) (effect size = 0.99 in theater and 0.78 in non-theater Veterans; p < .001 for both) and had increased disability on the WHODAS 2.0 summary score (effect size = 1.02 in theater and 0.96 in non-theater Veterans; p < .001 for both). Combat exposure, independent of PTSD status, was associated with lower PCS and MCS scores and increased disability (all p < .05, for trend). Within-pair analyses in twins discordant for PTSD produced consistent findings.

Conclusions

Vietnam-era Veterans with PTSD have diminished functioning and increased disability. The poor functional status of aging combat-exposed Veterans is of particular concern.     

Comparison of selective media for isolation of Campylobacter jejuni/coli

A comparison of Skirrow's, Butzler's, Blaser's, Campy-BAP and Preston media for Campylobacter spp was made using human, animal and environmental specimens. Butzler's medium gave the lowest isolation rate and Preston medium, which was the most selective, the highest isolation rate. Enrichment culture using Preston enrichment broth gave a higher isolation rate than direct plating onto Preston medium.