282 research outputs found

    Prenatal hypoxia induces increased cardiac contractility on a background of decreased capillary density.

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    Background: Chronic hypoxia in utero (CHU) is one of the most common insults to fetal development and may be associated with poor cardiac recovery from ischaemia-reperfusion injury,yet the effects on normal cardiac mechanical performance are poorly understood. Methods: Pregnant female wistar rats were exposed to hypoxia (12% oxygen, balance nitrogen)for days 10–20 of pregnancy. Pups were born into normal room air and weaned normally. At 10 weeks of age, hearts were excised under anaesthesia and underwent retrograde 'Langendorff' perfusion. Mechanical performance was measured at constant filling pressure (100 cm H2O) with intraventricular balloon. Left ventricular free wall was dissected away and capillary density estimated following alkaline phosphatase staining. Expression of SERCA2a and Nitric Oxide Synthases (NOS) proteins were estimated by immunoblotting. Results: CHU significantly increased body mass (P < 0.001) compared with age-matched control rats but was without effect on relative cardiac mass. For incremental increases in left ventricular balloon volume, diastolic pressure was preserved. However, systolic pressure was significantly greater following CHU for balloon volume = 50 μl (P < 0.01) and up to 200 μl (P < 0.05). For higher balloon volumes systolic pressure was not significantly different from control. Developed pressures were correspondingly increased relative to controls for balloon volumes up to 250 μl (P < 0.05).Left ventricular free wall capillary density was significantly decreased in both epicardium (18%; P <0.05) and endocardium (11%; P < 0.05) despite preserved coronary flow. Western blot analysis revealed no change to the expression of SERCA2a or nNOS but immuno-detectable eNOS protein was significantly decreased (P < 0.001) in cardiac tissue following chronic hypoxia in utero. Conclusion: These data offer potential mechanisms for poor recovery following ischaemia, including decreased coronary flow reserve and impaired angiogenesis with subsequent detrimental effects of post-natal cardiac performance

    Lighting and perceptual cues: Effects on gait measures of older adults at high and low risk for falls

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    <p>Abstract</p> <p>Background</p> <p>The visual system plays an important role in maintaining balance. As a person ages, gait becomes slower and stride becomes shorter, especially in dimly lighted environments. Falls risk has been associated with reduced speed and increased gait variability.</p> <p>Methods</p> <p>Twenty-four older adults (half identified at risk for falls) experienced three lighting conditions: pathway illuminated by 1) general ceiling-mounted fixtures, 2) conventional plug-in night lights and 3) plug-in night lights supplemented by laser lines outlining the pathway. Gait measures were collected using the GAITRite<sup>© </sup>walkway system.</p> <p>Results</p> <p>Participants performed best under the general ceiling-mounted light system and worst under the night light alone. The pathway plus night lights increased gait velocity and reduced step length variability compared to the night lights alone in those at greater risk of falling.</p> <p>Conclusions</p> <p>Practically, when navigating in more challenging environments, such as in low-level ambient illumination, the addition of perceptual cues that define the horizontal walking plane can potentially reduce falls risks in older adults.</p

    Coincidence of paroxysmal supraventricular tachycardia and panic disorder: two case reports

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    Panic disorder (PD) is characterised by sudden attacks of intense fear with somatic symptoms including palpitations and tachycardia. Reciprocally, palpitations caused by paroxysmal supraventricular tachycardia (PSVT) are commonly associated with anxiety and may therefore be misdiagnosed as PD. As demonstrated by two case reports, PSVT and PD can occur comorbidly in a chronological sequence, with PSVT possibly precipitating and maintaining PD via interoceptive processes or, alternatively, with PD increasing the risk for PSVT by elevating stress levels. As both PSVT and PD require different treatments, potentially helpful differential clinical diagnostic criteria are proposed

    Interviewer BMI effects on under- and over-reporting of restrained eating: evidence from a national Dutch face-to-face survey and a postal follow-up

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    Contains fulltext : 102650pub.pdf (publisher's version ) (Open Access)Objectives To determine the effect of interviewer BMI on self-reported restrained eating in a face-to-face survey and to examine under- and over-reporting using the face-to face study and a postal follow-up. Methods A sample of 1,212 Dutch adults was assigned to 98 interviewers with different BMI who administered an eating questionnaire. To further evaluate misreporting a mail follow-up was conducted among 504 participants. Data were analyzed using two-level hierarchical models. Results Interviewer BMI had a positive effect on restrained eating. Normal weight and pre-obese interviewers obtained valid responses, underweight interviewers stimulated underreporting whereas obese interviewers triggered overreporting. Conclusion In face-to-face interviews self-reported dietary restraint is distorted by interviewer BMI. This result has implications for public health surveys, the more so given the expanding obesity epidemic.5 p

    Voluntary motor drive: possible reduction in Tourette syndrome

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    Electrophysiologically, Tourette syndrome (TS) is characterized by shortened cortical silent period (CSP), reflecting decreased motor inhibition. However, voluntary versus involuntary aspects of inhibitory functions in TS are not well understood. Hence, investigating voluntary motor drive (VMD) could help to elucidate this issue. A group of 14 healthy adolescents was compared with subjects of same age suffering from TS with (N = 6) and without (N = 6) presence of distal tics. Basic resting and active motor thresholds (RMT and AMT, respectively) as well as suprathreshold transcranial magnetic stimulation-conditioned RMT and AMT were determined during the CSP. The difference between AMT and RMT was considered as VMD quantum. No group-differences were found in RMT or AMT. Subjects with distal tics showed reduced VMD compared to healthy controls while patients without distal tics did not differ from controls. In the second half of CSP, patients with distal tics showed also diminished VMD compared to tic-patients without distal tics. The findings support the notion, that TS shows possible reduction of VMD and is associated with central motor threshold alterations confined to the very motor networks related to the tics observed

    A software pipeline for processing and identification of fungal ITS sequences

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    <p>Abstract</p> <p>Background</p> <p>Fungi from environmental samples are typically identified to species level through DNA sequencing of the nuclear ribosomal internal transcribed spacer (<it>ITS</it>) region for use in BLAST-based similarity searches in the International Nucleotide Sequence Databases. These searches are time-consuming and regularly require a significant amount of manual intervention and complementary analyses. We here present software – in the form of an identification pipeline for large sets of fungal <it>ITS </it>sequences – developed to automate the BLAST process and several additional analysis steps. The performance of the pipeline was evaluated on a dataset of 350 <it>ITS </it>sequences from fungi growing as epiphytes on building material.</p> <p>Results</p> <p>The pipeline was written in Perl and uses a local installation of NCBI-BLAST for the similarity searches of the query sequences. The variable subregion <it>ITS2 </it>of the <it>ITS </it>region is extracted from the sequences and used for additional searches of higher sensitivity. Multiple alignments of each query sequence and its closest matches are computed, and query sequences sharing at least 50% of their best matches are clustered to facilitate the evaluation of hypothetically conspecific groups. The pipeline proved to speed up the processing, as well as enhance the resolution, of the evaluation dataset considerably, and the fungi were found to belong chiefly to the <it>Ascomycota</it>, with <it>Penicillium </it>and <it>Aspergillus </it>as the two most common genera. The <it>ITS2 </it>was found to indicate a different taxonomic affiliation than did the complete <it>ITS </it>region for 10% of the query sequences, though this figure is likely to vary with the taxonomic scope of the query sequences.</p> <p>Conclusion</p> <p>The present software readily assigns large sets of fungal query sequences to their respective best matches in the international sequence databases and places them in a larger biological context. The output is highly structured to be easy to process, although it still needs to be inspected and possibly corrected for the impact of the incomplete and sometimes erroneously annotated fungal entries in these databases. The open source pipeline is available for UNIX-type platforms, and updated releases of the target database are made available biweekly. The pipeline is easily modified to operate on other molecular regions and organism groups.</p

    Traumatic brain injury as a risk factor for Alzheimer disease. Comparison of two retrospective autopsy cohorts with evaluation of ApoE genotype

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    BACKGROUND AND PURPOSE: The impact of traumatic brain injury (TBI) on the pathogenesis of Alzheimer disease (AD) is still controversial. The aim of our retrospective autopsy study was to assess the impact of TBE and ApoE allele frequency on the development of AD. MATERIAL AND METHODS: We examined 1. the incidence of AD pathology (Braak stageing, CERAD, NIA-Reagan Institute criteria) in 58 consecutive patients (mean age ± SD 77.0 ± 6.8 years) with residual closed TBI lesions, and 2. the frequency of TBI residuals in 57 age-matched autopsy proven AD cases. In both series, ApoE was evaluated from archival paraffin-embedded brain material. RESULTS: 1. TBE series: 12.1 % showed definite and 10.3% probable AD (mean age 77.6 and 75.2 years), only 2/13 with ApoEε3/4. From 45 (77.6%) non-AD cases (mean age 78.2 years), 3 had ApoEε3/4. The prevalence of 22.4% AD in this small autopsy cohort was significantly higher than 3.3% in a recent large clinical series and 14% in the general population over age 70. 2. In the AD cohort with ApoEε4 allele frequency of 30% similar to other AD series, residuals of closed TBI were seen in 4 brains (7%) (mean age ± SD 78.2 ± 6.4), all lacking the ApoEε4 allele. TBI incidence was slightly lower than 8.5% in the clinical MIRAGE study. CONCLUSIONS: The results of this first retrospective autopsy study of TBI, ApoEε allele frequency, and AD confirm clinical studies suggesting severe TBI to be a risk factor for the development AD higher in subjects lacking ApoEε4 alleles. Further studies in larger autopsy series are needed to elucidate the relationship between TBI, genetic predisposition, and AD
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