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M R Bakhshi J C Myers P S Howard D R Soprano E P Kirby 《Biochimica et biophysica acta》1992,1132(3):325-328
A cDNA library, constructed from bovine heart endothelial cell poly(A)+ RNA, was screened using a BstXI fragment of human von Willebrand and factor (vWF) cDNA as a probe. This probe codes for the major adhesion domain of vWF that includes the GPIb, collagen and heparin binding domains. Of the ten positive clones obtained, a clone that spanned the region of interest was sequenced by the dideoxynucleotide method yielding a sequence of 1550 bp. This region of the bovine cDNA codes for amino acids corresponding to #262 to #777 in human vWF and encompasses the entire pro adhesion domain. Both the nucleotide sequence and the deduced amino acid sequence are 82% homologous to those of human vWF. Cysteine residues #471, 474, 509 and 695, which form intrachain bonds in human vWF, are also present in the bovine vWF sequence. 相似文献
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Bita Zamiri Mila Mirceta Karol Bomsztyk Robert B. Macgregor Jr. Christopher E. Pearson 《Nucleic acids research》2015,43(20):10055-10064
Unusual DNA/RNA structures of the C9orf72 repeat may participate in repeat expansions or pathogenesis of amyotrophic lateral sclerosis and frontotemporal dementia. Expanded repeats are CpG methylated with unknown consequences. Typically, quadruplex structures form by G-rich but not complementary C-rich strands. Using CD, UV and electrophoresis, we characterized the structures formed by (GGGGCC)8 and (GGCCCC)8 strands with and without 5-methylcytosine (5mCpG) or 5-hydroxymethylcytosine (5hmCpG) methylation. All strands formed heterogenous mixtures of structures, with features of quadruplexes (at pH 7.5, in K+, Na+ or Li+), but no feature typical of i-motifs. C-rich strands formed quadruplexes, likely stabilized by G•C•G•C-tetrads and C•C•C•C-tetrads. Unlike G•G•G•G-tetrads, some G•C•G•C-tetrad conformations do not require the N7-Guanine position, hence C9orf72 quadruplexes still formed when N7-deazaGuanine replace all Guanines. 5mCpG and 5hmCpG increased and decreased the thermal stability of these structures. hnRNPK, through band-shift analysis, bound C-rich but not G-rich strands, with a binding preference of unmethylated > 5hmCpG > 5mCpG, where methylated DNA-protein complexes were retained in the wells, distinct from unmethylated complexes. Our findings suggest that for C-rich sequences interspersed with G-residues, one must consider quadruplex formation and that methylation of quadruplexes may affect epigenetic processes. 相似文献
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Aim
To investigate whether hormonal fluctuations during the menstrual cycle affect corticospinal excitability, intracortical inhibition (ICI) or facilitation (ICF) in primary motor cortex, and also whether the hormonal fluctuations have any effect on manual dexterity in neurologically intact women.Materials and Methods
Twenty volunteers (10 Female, 10 Male) were included in this study. The levels of progesterone and estradiol were measured from saliva during the women’s menstrual follicular, ovulation and mid-luteal phases. Motor evoked potentials were recorded from the right first dorsal interosseous muscle. Single and paired-pulse Transcranial Magnetic Stimulation (TMS) were delivered in a block of 20 stimuli. With paired-pulse technique, 3ms and 10ms inter-stimulus intervals were used to assess ICI and ICF, respectively. The Grooved Pegboard Test (GPT) was completed in each session before the TMS assessments. Male participants were tested at similar time intervals as female participants.Results
Mixed design ANOVA revealed that GPT score in female participants was significantly lower at the mid-luteal phase compared to the ovulation phase (p = 0.017). However, it was not correlated with progesterone or estrogen fluctuations during the menstrual cycle. The results also showed that the effect of phase, sex and the interaction of phase by sex for resting motor threshold, ICI or ICF were not significant (p > 0.05).Conclusion
Manual dexterity performance fluctuates during the menstrual cycle in neurologically intact women, which might be due to the balance of the neuromodulatory effects of P4 and E2 in the motor cortex during different phases. 相似文献88.
Background
Although 80% of persons with disabilities live in low and middle-income countries, there is still a lack of comprehensive, cross-culturally validated tools to identify persons facing activity limitations and functioning difficulties in these settings. In absence of such a tool, disability estimates vary considerably according to the methodology used, and policies are based on unreliable estimates.Methods and Findings
The Disability Screening Questionnaire composed of 27 items (DSQ-27) was initially designed by a group of international experts in survey development and disability in Afghanistan for a national survey. Items were selected based on major domains of activity limitations and functioning difficulties linked to an impairment as defined by the International Classification of Functioning, Disability and Health. Face, content and construct validity, as well as sensitivity and specificity were examined. Based on the results obtained, the tool was subsequently refined and expanded to 34 items, tested and validated in Darfur, Sudan. Internal consistency for the total DSQ-34 using a raw and standardized Cronbach’s Alpha and within each domain using a standardized Cronbach’s Alpha was examined in the Asian context (India and Nepal). Exploratory factor analysis (EFA) using principal axis factoring (PAF) evaluated the lowest number of factors to account for the common variance among the questions in the screen. Test-retest reliability was determined by calculating intraclass correlation (ICC) and inter-rater reliability by calculating the kappa statistic; results were checked using Bland-Altman plots. The DSQ-34 was further tested for standard error of measurement (SEM) and for the minimum detectable change (MDC). Good internal consistency was indicated by Cronbach’s Alpha of 0.83/0.82 for India and 0.76/0.78 for Nepal. We confirmed our assumption for EFA using the Kaiser-Meyer-Olkin measure of sampling well above the accepted cutoff of 0.40 for India (0.82) and Nepal (0.82). The criteria for Bartlett’s test of sphericity were also met for both India (< .001) and Nepal (< .001). Estimates of reliability from the two countries reached acceptable levels of ICC of 0.75 (p<0.001) for India of 0.77 for Nepal (p<0.001) and good strength of agreement for weighted kappa (respectively 0.77 and 0.79). The SEM/MDC was 0.80/2.22 for India and 0.96/2.66 for Nepal indicating a smaller amount of measurement error in the screen.Conclusions
In Nepal and India, the DSQ-34 shows strong psychometric properties that indicate that it effectively discriminates between persons with and without disabilities. This instrument can be used in association with other instruments for the purpose of comparing health outcomes of persons with and without disabilities in LMICs. 相似文献89.
Samuel Wanji Nathalie Amvongo-Adjia Benjamin Koudou Abdel Jelil Njouendou Patrick W. Chounna Ndongmo Jonas A. Kengne-Ouafo Fabrice R. Datchoua-Poutcheu Bridget Adzemye Fovennso Dizzle Bita Tayong Fanny Fri Fombad Peter U. Fischer Peter I. Enyong Moses Bockarie 《PLoS neglected tropical diseases》2015,9(11)
Background
Immunochromatographic card test (ICT) is a tool to map the distribution of Wuchereria bancrofti. In areas highly endemic for loaisis in DRC and Cameroon, a relationship has been envisaged between high L. loa microfilaria (Mf) loads and ICT positivity. However, similar associations have not been demonstrated from other areas with contrasting levels of L. loa endemicity. This study investigated the cross-reactivity of ICT when mapping lymphatic filariasis (LF) in areas with contrasting endemicity levels of loiasis and mansonellosis in Cameroon.Methodology/Principal Findings
A cross-sectional study to assess the prevalence and intensity of W. bancrofti, L. loa and M. perstans was carried out in 42 villages across three regions (East, North-west and South-west) of the Cameroon rainforest domain. Diurnal blood was collected from participants for the detection of circulating filarial antigen (CFA) by ICT and assessment of Mf using a thick blood smear. Clinical manifestations of LF were also assessed. ICT positives and patients clinically diagnosed with lymphoedema were further subjected to night blood collection for the detection of W. bancrofti Mf. Overall, 2190 individuals took part in the study. Overall, 24 individuals residing in 14 communities were tested positive by ICT, with prevalence rates ranging from 0% in the South-west to 2.1% in the North-west. Lymphoedema were diagnosed in 20 individuals with the majority of cases found in the North-west (11/20), and none of them were tested positive by ICT. No Mf of W. bancrofti were found in the night blood of any individual with a positive ICT result or clinical lymphoedema. Positive ICT results were strongly associated with high L. loa Mf intensity with 21 subjects having more than 8,000 L. loa Mf ml/blood (Odds ratio = 15.4; 95%CI: 6.1–39.0; p < 0.001). Similarly, a strong positive association (Spearman’s rho = 0.900; p = 0.037) was observed between the prevalence of L. loa and ICT positivity by area: a rate of 1% or more of positive ICT results was found only in areas with an L. loa Mf prevalence above 15%. In contrast, there was no association between ICT positivity and M. perstans prevalence (Spearman’s rho = - 0.200; p = 0.747) and Mf density (Odds ratio = 1.8; 95%CI: 0.8–4.2; p = 0.192).Conclusions/Significance
This study has confirmed the strong association between the ICT positivity and L. loa intensity (Mf/ml of blood) at the individual level. Furthermore, the study has demonstrated that ICT positivity is strongly associated with high L. loa prevalence. These results suggest that the main confounding factor for positive ICT test card results are high levels of L. loa. The findings may indicate that W. bancrofti is much less prevalent in the Central African region where L. loa is highly endemic than previously assumed and accurate re-mapping of the region would be very useful for shrinking of the map of LF distribution. 相似文献90.