3,274 research outputs found

    A pygmy right whale Caperea marginata (Grey, 1846) stranded at Stanley, Tasmania

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    A pregnant female pygmy right whale, Caperea marginata (Gray, 1846) which stranded at West Beach, Stanley was examined within 24 hours of stranding. No significant pathological condition was detected in the carcase thus eliminating disease as the likely cause of stranding. However, the area is a notorious "whale trap", and it is therefore assumed that geographical and hydrological conditions accounted for the stranding. A number of interesting anatomical features are noted

    Matched increases in cerebral artery shear stress, irrespective of stimulus, induce similar changes in extra-cranial arterial diameter in humans.

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    The mechanistic role of arterial shear stress in the regulation of cerebrovascular responses to physiological stimuli (exercise and hypercapnia) is poorly understood. We hypothesised that, if shear stress is a key regulator of arterial dilation, then matched increases in shear, induced by distinct physiological stimuli, would trigger similar dilation of the large extra-cranial arteries. Participants ( n = 10) participated in three 30-min experimental interventions, each separated by ≥48 h: (1) mild-hypercapnia (FICO2:∼0.045); (2) submaximal cycling (EX; 60%HRreserve); or (3) resting (time-matched control, CTRL). Blood flow, diameter, and shear rate were assessed (via Duplex ultrasound) in the internal carotid and vertebral arteries (ICA, VA) at baseline, during and following the interventions. Hypercapnia and EX produced similar elevations in blood flow and shear rate through the ICA and VA ( p < 0.001), which were both greater than CTRL. Vasodilation of ICA and VA diameter in response to hypercapnia (5.3 ± 0.8 and 4.4 ± 2.0%) and EX (4.7 ± 0.7 and 4.7 ± 2.2%) were similar, and greater than CTRL ( p < 0.001). Our findings indicate that matched levels of shear, irrespective of their driving stimulus, induce similar extra-cranial artery dilation. We demonstrate, for the first time in humans, an important mechanistic role for the endothelium in regulating cerebrovascular response to common physiological stimuli in vivo

    Practices participating in a dental PBRN have substantial and advantageous diversity even though as a group they have much in common with dentists at large

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    <p>Abstract</p> <p>Background</p> <p>Practice-based research networks offer important opportunities to move recent advances into routine clinical practice. If their findings are not only generalizable to dental practices at large, but can also elucidate how practice characteristics are related to treatment outcome, their importance is even further elevated. Our objective was to determine whether we met a key objective for The Dental Practice-Based Research Network (DPBRN): to recruit a diverse range of practitioner-investigators interested in doing DPBRN studies.</p> <p>Methods</p> <p>DPBRN participants completed an enrollment questionnaire about their practices and themselves. To date, more than 1100 practitioners from the five participating regions have completed the questionnaire. The regions consist of: Alabama/Mississippi, Florida/Georgia, Minnesota, Permanente Dental Associates, and Scandinavia (Denmark, Norway, and Sweden). We tested the hypothesis that there are statistically significant differences in key characteristics among DPBRN practices, based on responses from dentists who participated in DPBRN's first network-wide study (n = 546).</p> <p>Results</p> <p>There were statistically significant, substantive regional differences among DPBRN-participating dentists, their practices, and their patient populations.</p> <p>Conclusion</p> <p>Although as a group, participants have much in common with practices at large; their substantial diversity offers important advantages, such as being able to evaluate how practice differences may affect treatment outcomes, while simultaneously offering generalizability to dentists at large. This should help foster knowledge transfer in both the research-to-practice and practice-to-research directions.</p

    Worldwide trends in mortality from biliary tract malignancies

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    BACKGROUND: Intrahepatic cholangiocarcinomas are malignant tumors arising from the intrahepatic biliary tract. The pathogenesis of these tumors remains unknown. Although there is a marked global variation in prevalence, some recent studies have suggested an increase in mortality from intrahepatic cholangiocarcinoma in several regions of low endemicity. As the study of mortality trends may yield clues to possible etiological factors, we analyzed worldwide time trends in mortality from biliary tract malignancies. METHODS: Annual age-standardized rates for individual countries were compiled for deaths from biliary tract malignancies using the WHO database. These data were used to analyze gender and site-specific trends in mortality rates. RESULTS: An increasing trend for mortality from intrahepatic cholangiocarcinoma was noted in most countries. The average estimated annual percentage change (EAPC) in mortality rates for males was 6.9 ± 1.5, and for females was 5.1 ± 1.0. Increased mortality rates were observed in all geographic regions. Within Europe, increases were higher in Western Europe than in Central or Northern Europe. In contrast, mortality rates for extrahepatic biliary tract malignancies showed a decreasing trend in most countries, with an overall average EAPC of -0.3 ± 0.4 for males, but -1.3 ± 0.4 for females. CONCLUSIONS: There has been a marked global increase in mortality from intrahepatic, but not extra-hepatic, biliary tract malignancies

    Mother Positivity and Family Adjustment in Households with Children with a Serious Disability

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    Only limited attention has been given to parent coping resources in the positive adjustment of families of children with a disability. This study is the first to explore maternal positivity as a psychological coping resource related to family adjustment in these families. Consistent with broaden-and-build theory and prior positivity research, positivity was operationalized through a ratio of positive to negative affect scores. We employed longitudinal tracking over a 1 year interval. Children’s diagnostic categories included developmental conditions or impairments, mental health disorders, complex health conditions, physical/motor conditions or impairments, sensory impairments, and provisionally diagnosed conditions or impairments. We used a computer assisted telephone survey to gather psychological, family, and demographic information from 152 mothers in Alberta, Canada. Hierarchical regression analysis indicated mothers’ level of positivity and age, when controlled for family adjustment at Time 1, accounted for 46% of the variance in family adjustment at Time 2. That is, older mothers with higher positivity scores were found to live in households with higher levels of family adjustment after 1 year. These findings provide promising support for broaden-and-build theory, which posits that positive experienced emotions can offset and diminish the negative health and relationship impacts of chronic stress. Study findings support the salience of mothers’ positivity as a psychological coping resource, which is related to enhanced family adjustment in situations of childhood disability

    MFGE8 does not influence chorio-retinal homeostasis or choroidal neovascularization in vivo

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    Purpose: Milk fat globule-epidermal growth factor-factor VIII (MFGE8) is necessary for diurnal outer segment phagocytosis and promotes VEGF-dependent neovascularization. The prevalence of two single nucleotide polymorphisms (SNP) in MFGE8 was studied in two exsudative or “wet” Age-related Macular Degeneration (AMD) groups and two corresponding control groups. We studied the effect of MFGE8 deficiency on retinal homeostasis with age and on choroidal neovascularization (CNV) in mice. Methods: The distribution of the SNP (rs4945 and rs1878326) of MFGE8 was analyzed in two groups of patients with “wet” AMD and their age-matched controls from Germany and France. MFGE8-expressing cells were identified in Mfge8+/− mice expressing ß-galactosidase. Aged Mfge8+/− and Mfge8−/− mice were studied by funduscopy, histology, electron microscopy, scanning electron microscopy of vascular corrosion casts of the choroid, and after laser-induced CNV. Results: rs1878326 was associated with AMD in the French and German group. The Mfge8 promoter is highly active in photoreceptors but not in retinal pigment epithelium cells. Mfge8−/− mice did not differ from controls in terms of fundus appearance, photoreceptor cell layers, choroidal architecture or laser-induced CNV. In contrast, the Bruch's membrane (BM) was slightly but significantly thicker in Mfge8−/− mice as compared to controls. Conclusions: Despite a reproducible minor increase of rs1878326 in AMD patients and a very modest increase in BM in Mfge8−/− mice, our data suggests that MFGE8 dysfunction does not play a critical role in the pathogenesis of AMD

    Genome-wide linkage analysis of 972 bipolar pedigrees using single-nucleotide polymorphisms.

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    Because of the high costs associated with ascertainment of families, most linkage studies of Bipolar I disorder (BPI) have used relatively small samples. Moreover, the genetic information content reported in most studies has been less than 0.6. Although microsatellite markers spaced every 10 cM typically extract most of the genetic information content for larger multiplex families, they can be less informative for smaller pedigrees especially for affected sib pair kindreds. For these reasons we collaborated to pool family resources and carried out higher density genotyping. Approximately 1100 pedigrees of European ancestry were initially selected for study and were genotyped by the Center for Inherited Disease Research using the Illumina Linkage Panel 12 set of 6090 single-nucleotide polymorphisms. Of the ~1100 families, 972 were informative for further analyses, and mean information content was 0.86 after pruning for linkage disequilibrium. The 972 kindreds include 2284 cases of BPI disorder, 498 individuals with bipolar II disorder (BPII) and 702 subjects with recurrent major depression. Three affection status models (ASMs) were considered: ASM1 (BPI and schizoaffective disorder, BP cases (SABP) only), ASM2 (ASM1 cases plus BPII) and ASM3 (ASM2 cases plus recurrent major depression). Both parametric and non-parametric linkage methods were carried out. The strongest findings occurred at 6q21 (non-parametric pairs LOD 3.4 for rs1046943 at 119 cM) and 9q21 (non-parametric pairs logarithm of odds (LOD) 3.4 for rs722642 at 78 cM) using only BPI and schizoaffective (SA), BP cases. Both results met genome-wide significant criteria, although neither was significant after correction for multiple analyses. We also inspected parametric scores for the larger multiplex families to identify possible rare susceptibility loci. In this analysis, we observed 59 parametric LODs of 2 or greater, many of which are likely to be close to maximum possible scores. Although some linkage findings may be false positives, the results could help prioritize the search for rare variants using whole exome or genome sequencing
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