1,970 research outputs found
Recommended from our members
Evaluation of coated QCM for the detection of atmospheric ozone
A coated acoustic wave sensor has been developed to selectively detect atmospheric ozone. The selective detection has been assessed using a variety of coatings: beeswax, gallic acid, indigo carmine, polybutadiene, potassium iodide and sodium nitrite. Polybutadiene was the most sensitive with a limit of detection of 55 ppb. The sensitivity was improved by operating at higher harmonics and was shown to increase linearly with harmonic up to the 11th harmonic. This novel work shows that ozone detection can be improved by operating at the crystals' harmonic frequencies and in conjunction with a suitable flow rate, a potentially highly sensitive and fast response sensor can be created based on acoustic wave technolog
Ubiquitin ligase MKRN1 modulates telomere length homeostasis through a proteolysis of hTERT
Telomere homeostasis is regulated by telomerase and a collection of associatedproteins. Telomerase is, in turn, regulated by post-translational modifications of the rate-limiting catalytic subunit hTERT. Here we show that disruption of Hsp90 by geldanamycin promotes efficient ubiquitination and proteasome-mediated degradation of hTERT. Furthermore, we have used the yeast two-hybrid method to identify a novel RING finger gene (MKRN1) encoding an E3 ligase that mediates ubiquitination of hTERT. Overexpression of MKRN1 in telomerase-positive cells promotes the degradation of hTERT and decreases telomerase activity and subsequently telomere length. Our data suggest that MKRN1 plays an important role in modulating telomere length homeostasis through a dynamic balance involving hTERT protein stability
Targeting of MKRNI for identifying cancer treatment agents
The molecular chaperone Hsp90 binds specifically to hTERT and is required for assembly of active telomerase activity. We show that disruption of Hsp90 function gy geldanamycin efficient ubiquitination and proteasome-mediated degradation of hTERT
Segond's fracture: a biomechanical cadaveric study using navigation
Background Segond’s fracture is a well-recognised radiological
sign of an anterior cruciate ligament (ACL) tear.
While previous studies evaluated the role of the anterolateral
ligament (ALL) and complex injuries on rotational
stability of the knee, there are no studies on the biomechanical
effect of Segond’s fracture in an ACL deficient
knee. The aim of this study was to evaluate the effect of a
Segond’s fracture on knee rotation stability as evaluated by
a navigation system in an ACL deficient knee.
Materials and methods Three different conditions were
tested on seven knee specimens: intact knee, ACL deficient
knee and ACL deficient knee with Segond’s fracture. Static
and dynamic measurements of anterior tibial translation
(ATT) and axial tibial rotation (ATR) were recorded by the
navigation system (2.2 OrthoPilot ACL navigation system
B. Braun Aesculap, Tuttlingen, Germany).
Results Static measurements at 30 showed that the mean
ATT at 30 of knee flexion was 5.1 ± 2.7 mm in the ACL
intact condition, 14.3 ± 3.1 mm after ACL cut
(P = 0.005), and 15.2 ± 3.6 mm after Segond’s fracture
(P = 0.08). The mean ATR at 30 of knee flexion was
20.7 ± 4.8 in the ACL intact condition, 26.9 ± 4.1 in
the ACL deficient knee (P[0.05) and 30.9 ± 3.8 after
Segond’s fracture (P = 0.005). Dynamic measurements
during the pivot-shift showed that the mean ATT was
7.2 ± 2.7 mm in the intact knee, 9.1 ± 3.3 mm in the
ACL deficient knee(P = 0.04) and 9.7 ± 4.3 mm in the
ACL deficient knee with Segond’s fracture (P = 0.07).
The mean ATR was 9.6 ± 1.8 in the intact knee,
12.3 ± 2.3 in the ACL deficient knee (P[0.05) and
19.1 ± 3.1 in the ACL deficient knee with Segond’s
lesion (P = 0.016).
Conclusion An isolated lesion of the ACL only affects
ATT during static and dynamic measurements, while the
addition of Segond’s fracture has a significant effect on
ATR in both static and dynamic execution of the pivot-shift
test, as evaluated with the aid of navigation
Influenza vaccination coverage rates in five European countries during season 2006/07 and trends over six consecutive seasons
<p>Abstract</p> <p>Background</p> <p>The objectives of the survey were to identify the level of influenza vaccination coverage in five European countries between 2001 and 2007, to understand the drivers and barriers to vaccination, to assess vaccination intentions for the winter 2007/08 as well as major encouraging factors for vaccination.</p> <p>Methods</p> <p>Between 2001 and 2007, representative household surveys were performed with telephone or mailed (France) interviews of individuals aged 14 and above. The questionnaire used in the UK, Germany, Italy, France and Spain was essentially the same in all seasons. The data were subsequently pooled. Four target groups were defined for the analysis: 1) persons aged 65 years and over; 2) persons working in the medical field; 3) chronically ill persons and 4) combined target group composed of individuals belonging to one or more of the previous groups 1, 2 or 3.</p> <p>Results</p> <p>In 2006/07, vaccination coverage was, 25.0% in UK, 27.4% in Germany, 21.8% in Spain, 24.2% in France and 24.4% in Italy. During six influenza seasons (2001–2007), vaccination coverage showed a slight positive trend in the five countries (p ≤ 0.0001). In the elderly (≥ 65 years), across all countries, no significant trend was seen; the vaccination rate decreased non-significantly from a peak of 64.2% in season 2005/06 to 61.1% in season 2006/07. The most frequent reason for getting vaccinated was a recommendation by the family doctor or nurse (51%), and this was also perceived as the major encouraging factor for vaccination (61%). The main reason for not getting vaccinated was feeling unlikely to catch the flu (36%).</p> <p>Conclusion</p> <p>In the UK, Germany and Spain, influenza vaccination coverage rates in season 2006/07 dropped slightly compared to the previous season. However, a trend of increasing vaccination coverage was observed from 2001/02 to 2006/07 across Europe. The family doctor is the major source of encouragement for individuals getting vaccinated. Efforts to overcome the barriers to vaccination need to be put in place to reach the WHO objective of 75% coverage in the elderly by 2010. This is a major challenge to be faced by governments, healthcare workers and healthcare organisations.</p
The Quality of Reporting of Cohort, Case-Control Studies in the Korean Journal of Family Medicine
Nutritional status and structural brain changes in Alzheimer's disease: The NUDAD project
INTRODUCTION: Weight loss is associated with higher mortality and progression of cognitive decline, but its associations with magnetic resonance imaging (MRI) changes related to Alzheimer's disease (AD) are unknown. METHODS: We included 412 patients from the NUDAD project, comprising 129 with AD dementia, 107 with mild cognitive impairment (MCI), and 176 controls. Associations between nutritional status and MRI measures were analyzed using linear regression, adjusted for age, sex, education, cognitive functioning, and cardiovascular risk factors. RESULTS: Lower body mass index (BMI), fat mass (FM), and fat free mass index were associated with higher medial temporal atrophy (MTA) scores. Lower BMI, FM, and waist circumference were associated with more microbleeds. Stratification by diagnosis showed that the observed associations with microbleeds were only significant in MCI. DISCUSSION: Lower indicators of nutritional status were associated with more MTA and microbleeds, with largest effect sizes in MCI
Impact of Vitamin D Supplementation on Arterial Vasomotion, Stiffness and Endothelial Biomarkers in Chronic Kidney Disease Patients
Background: Cardiovascular events are frequent and vascular endothelial function is abnormal in patients with chronic
kidney disease (CKD). We demonstrated endothelial dysfunction with vitamin D deficiency in CKD patients; however the impact of cholecalciferol supplementation on vascular stiffness and vasomotor function, endothelial and bone biomarkers in CKD patients with low 25-hydroxy vitamin D [25(OH)D] is unknown, which this study investigated.
Methods: We assessed non-diabetic patients with CKD stage 3/4, age 17–80 years and serum 25(OH)D ,75 nmol/L. Brachial
artery Flow Mediated Dilation (FMD), Pulse Wave Velocity (PWV), Augmentation Index (AI) and circulating blood biomarkers were evaluated at baseline and at 16 weeks. Oral 300,000 units cholecalciferol was administered at baseline and 8-weeks.
Results: Clinical characteristics of 26 patients were: age 50614 (mean61SD) years, eGFR 41611 ml/min/1.73 m2, males
73%, dyslipidaemia 36%, smokers 23% and hypertensives 87%. At 16-week serum 25(OH)D and calcium increased (43616
to 84629 nmol/L, p,0.001 and 2.3760.09 to 2.4260.09 mmol/L; p = 0.004, respectively) and parathyroid hormone
decreased (10.868.6 to 7.464.4; p = 0.001). FMD improved from 3.163.3% to 6.163.7%, p = 0.001. Endothelial biomarker
concentrations decreased: E-Selectin from 566662123 to 525662058 pg/mL; p = 0.032, ICAM-1, 3.4560.01 to
3.1061.04 ng/mL; p = 0.038 and VCAM-1, 54633 to 42633 ng/mL; p = 0.006. eGFR, BP, PWV, AI, hsCRP, von Willebrand
factor and Fibroblast Growth Factor-23, remained unchanged.
Conclusion: This study demonstrates for the first time improvement of endothelial vasomotor and secretory functions with vitamin D in CKD patients without significant adverse effects on arterial stiffness, serum calcium or FGF-23.
Trial Registration: ClinicalTrials.gov NCT0200571
Overview of a paediatric renal transplant programme
No Abstract. South African Medical Journal Vol. 96(9) (Part 2) 2006: 955-95
Revealing mammalian evolutionary relationships by comparative analysis of gene clusters
Many software tools for comparative analysis of genomic sequence data have been released in recent decades. Despite this, it remains challenging to determine evolutionary relationships in gene clusters due to their complex histories involving duplications, deletions, inversions, and conversions. One concept describing these relationships is orthology. Orthologs derive from a common ancestor by speciation, in contrast to paralogs, which derive from duplication. Discriminating orthologs from paralogs is a necessary step in most multispecies sequence analyses, but doing so accurately is impeded by the occurrence of gene conversion events. We propose a refined method of orthology assignment based on two paradigms for interpreting its definition: by genomic context or by sequence content. X-orthology (based on context) traces orthology resulting from speciation and duplication only, while N-orthology (based on content) includes the influence of conversion events
- …