692 research outputs found
Cognitive phenotype of juvenile absence epilepsy: An investigation of patients and unaffected siblings
Objective: The cognitive profile of juvenile absence epilepsy (JAE) remains largely uncharacterized. This study aimed to: (1) elucidate the neuropsychological profile of JAE; (2) identify familial cognitive traits by investigating unaffected JAE siblings; (3) establish the clinical meaningfulness of JAE-associated cognitive traits; (4) determine whether cognitive traits across the idiopathic generalized epilepsy (IGE) spectrum are shared or syndrome-specific, by comparing JAE to juvenile myoclonic epilepsy (JME); and (5) identify relationships between cognitive abilities and clinical characteristics. Methods: We investigated 123 participants—23 patients with JAE, 16 unaffected siblings of JAE patients, 45 healthy controls, and 39 patients with JME—who underwent a comprehensive neuropsychological test battery including measures within four cognitive domains: attention/psychomotor speed, language, memory, and executive function. We correlated clinical measures with cognitive performance data to decode effects of age at onset and duration of epilepsy. Results: Cognitive performance in individuals with JAE was reduced compared to controls across attention/psychomotor speed, language, and executive function domains; those with ongoing seizures additionally showed lower memory scores. Patients with JAE and their unaffected siblings had similar language impairment compared to controls. Individuals with JME had worse response inhibition than those with JAE. Across all patients, those with older age at onset had better attention/psychomotor speed performance. Significance: JAE is associated with wide-ranging cognitive difficulties that encompass domains reliant on frontal lobe processing, including language, attention, and executive function. JAE siblings share impairment with patients on linguistic measures, indicative of a familial trait. Executive function subdomains may be differentially affected across the IGE spectrum. Cognitive abilities are detrimentally modulated by an early age at seizure onset
Rationing tests for drug-resistant tuberculosis - who are we prepared to miss?
BACKGROUND: Early identification of patients with drug-resistant tuberculosis (DR-TB) increases the likelihood of treatment success and interrupts transmission. Resource-constrained settings use risk profiling to ration the use of drug susceptibility testing (DST). Nevertheless, no studies have yet quantified how many patients with DR-TB this strategy will miss. METHODS: A total of 1,545 subjects, who presented to Lima health centres with possible TB symptoms, completed a clinic-epidemiological questionnaire and provided sputum samples for TB culture and DST. The proportion of drug resistance in this population was calculated and the data was analysed to demonstrate the effect of rationing tests to patients with multidrug-resistant TB (MDR-TB) risk factors on the number of tests needed and corresponding proportion of missed patients with DR-TB. RESULTS: Overall, 147/1,545 (9.5%) subjects had culture-positive TB, of which 32 (21.8%) had DR-TB (MDR, 13.6%; isoniazid mono-resistant, 7.5%; rifampicin mono-resistant, 0.7%). A total of 553 subjects (35.8%) reported one or more MDR-TB risk factors; of these, 506 (91.5%; 95% CI, 88.9-93.7%) did not have TB, 32/553 (5.8%; 95% CI, 3.4-8.1%) had drug-susceptible TB, and only 15/553 (2.7%; 95% CI, 1.5-4.4%) had DR-TB. Rationing DST to those with an MDR-TB risk factor would have missed more than half of the DR-TB population (17/32, 53.2%; 95% CI, 34.7-70.9). CONCLUSIONS: Rationing DST based on known MDR-TB risk factors misses an unacceptable proportion of patients with drug-resistance in settings with ongoing DR-TB transmission. Investment in diagnostic services to allow universal DST for people with presumptive TB should be a high priority
The regulatory subunit of PKA-I remains partially structured and undergoes β-aggregation upon thermal denaturation
Background: The regulatory subunit (R) of cAMP-dependent protein kinase (PKA) is a modular flexible protein that responds with large conformational changes to the binding of the effector cAMP. Considering its highly dynamic nature, the protein is rather stable. We studied the thermal denaturation of full-length RIα and a truncated RIα(92-381) that contains the tandem cyclic nucleotide binding (CNB) domains A and B. Methodology/Principal Findings: As revealed by circular dichroism (CD) and differential scanning calorimetry, both RIα proteins contain significant residual structure in the heat-denatured state. As evidenced by CD, the predominantly α-helical spectrum at 25°C with double negative peaks at 209 and 222 nm changes to a spectrum with a single negative peak at 212-216 nm, characteristic of β-structure. A similar α→β transition occurs at higher temperature in the presence of cAMP. Thioflavin T fluorescence and atomic force microscopy studies support the notion that the structural transition is associated with cross-β-intermolecular aggregation and formation of non-fibrillar oligomers. Conclusions/Significance: Thermal denaturation of RIα leads to partial loss of native packing with exposure of aggregation-prone motifs, such as the B' helices in the phosphate-binding cassettes of both CNB domains. The topology of the β-sandwiches in these domains favors inter-molecular β-aggregation, which is suppressed in the ligand-bound states of RIα under physiological conditions. Moreover, our results reveal that the CNB domains persist as structural cores through heat-denaturation. © 2011 Dao et al
Moduli Stabilization and Cosmology of Type IIB on SU(2)-Structure Orientifolds
We consider type IIB flux compactifications on six-dimensional
SU(2)-structure manifolds with O5- and O7-planes. These six-dimensional spaces
allow not only for F_3 and H_3 fluxes but also for F_1 and F_5 fluxes. We
derive the four-dimensional N=1 scalar potential for such compactifications and
present one explicit example of a fully stabilized AdS vacuum with large volume
and small string coupling. We then discuss cosmological aspects of these
compactifications and derive several no-go theorems that forbid dS vacua and
slow-roll inflation under certain conditions. We also study concrete examples
of cosets and twisted tori and find that our no-go theorems forbid dS vacua and
slow-roll inflation in all but one of them. For the latter we find a dS
critical point with \epsilon numerically zero. However, the point has two
tachyons and eta-parameter \eta \approx -3.1.Comment: 35 pages + appendices, LaTeX2e; v2: numerical dS extremum added,
typos corrected, references adde
Global asthma prevalence in adults: findings from the cross-sectional world health survey
<p>Abstract</p> <p>Background</p> <p>Asthma is a major cause of disability, health resource utilization and poor quality of life world-wide. We set out to generate estimates of the global burden of asthma in adults, which may inform the development of strategies to address this common disease.</p> <p>Methods</p> <p>The World Health Survey (WHS) was developed and implemented by the World Health Organization in 2002-2003. A total of 178,215 individuals from 70 countries aged 18 to 45 years responded to questions related to asthma and related symptoms. The prevalence of asthma was based on responses to questions relating to self-reported doctor diagnosed asthma, clinical/treated asthma, and wheezing in the last 12 months.</p> <p>Results</p> <p>The global prevalence rates of doctor diagnosed asthma, clinical/treated asthma and wheezing in adults were 4.3%, 4.5%, and 8.6% respectively, and varied by as much as 21-fold amongst the 70 countries. Australia reported the highest rate of doctor diagnosed, clinical/treated asthma, and wheezing (21.0%, 21.5%, and 27.4%). Amongst those with clinical/treated asthma, almost 24% were current smokers, half reported wheezing, and 20% had never been treated for asthma.</p> <p>Conclusions</p> <p>This study provides a global estimate of the burden of asthma in adults, and suggests that asthma continues to be a major public health concern worldwide. The high prevalence of smoking remains a major barrier to combating the global burden of asthma. While the highest prevalence rates were observed in resource-rich countries, resource-poor nations were also significantly affected, posing a barrier to development as it stretches further the demands of non-communicable diseases.</p
Faecal pharmacokinetics of orally administered vancomycin in patients with suspected Clostridium difficile infection
<p>Abstract</p> <p>Background</p> <p>Oral vancomycin (125 mg qid) is recommended as treatment of severe <it>Clostridium difficile </it>infection (CDI). Higher doses (250 or 500 mg qid) are sometimes recommended for patients with very severe CDI, without supporting clinical evidence. We wished to determine to what extent faecal levels of vancomycin vary according to diarrhoea severity and dosage, and whether it is rational to administer high-dose vancomycin to selected patients.</p> <p>Methods</p> <p>We recruited hospitalized adults suspected to have CDI for whom oral vancomycin (125, 250 or 500 mg qid) had been initiated. Faeces were collected up to 3 times/day and levels were measured with the AxSYM fluorescence polarization immunoassay.</p> <p>Results</p> <p>Fifteen patients (9 with confirmed CDI) were treated with oral vancomycin. Patients with ≥4 stools daily presented lower faecal vancomycin levels than those with a lower frequency. Higher doses of oral vancomycin (250 mg or 500 mg qid) led to consistently higher faecal levels (> 2000 mg/L), which were 3 orders of magnitude higher than the MIC<sub>90 </sub>of vancomycin against <it>C. difficile</it>. One patient receiving 125 mg qid had levels below 50 mg/L during the first day of treatment.</p> <p>Conclusions</p> <p>Faecal levels of vancomycin are proportional to the dosage administered and, even in patients with increased stool frequency, much higher than the MIC<sub>90</sub>. Patients given the standard 125 mg qid dosage might have low faecal levels during the first day of treatment. A loading dose of 250 mg or 500 mg qid during the first 24-48 hours followed by the standard dosage should be evaluated in larger studies, since it might be less disruptive to the colonic flora and save unnecessary costs.</p
Falciparum malaria in young children of rural Burkina Faso: comparison of survey data in 1999 with 2009
<p>Abstract</p> <p>Background</p> <p>Roll Back Malaria (RBM) interventions such as insecticide-treated mosquito nets (ITN) and artemisinin-based combination therapy (ACT) have become implemented with different velocities in the endemic countries of sub-Saharan Africa (SSA) in recent years. There is conflicting evidence on how much can be achieved under real life conditions with the current interventions in the highly endemic savannah areas of SSA.</p> <p>Methods</p> <p>The study took place in a rural area of north-western Burkina Faso, which was defined as holoendemic in 1999. Clinical and parasitological data were compared in two cohorts of young children of the same age range from eight villages. Surveys took place in June and December of the year 1999 and 2009 respectively.</p> <p>Results</p> <p>Prevalence of mosquito net use increased from 22% in 1999 to 73% in 2009, with the majority of nets being ITNs in 2009. In 2009, <it>P. falciparum </it>prevalence was significantly lower compared to 1999 (overall reduction of 22.8%).</p> <p>Conclusions</p> <p>The reduction in malaria prevalence in young children observed between 1999 and 2009 in a rural and formerly malaria holoendemic area of Burkina Faso is likely attributable to the increase in ITN availability and utilization over time.</p
A microcosting study of microsurgery, LINAC radiosurgery, and gamma knife radiosurgery in meningioma patients
The aim of the present study is to determine and compare initial treatment costs of microsurgery, linear accelerator (LINAC) radiosurgery, and gamma knife radiosurgery in meningioma patients. Additionally, the follow-up costs in the first year after initial treatment were assessed. Cost analyses were performed at two neurosurgical departments in The Netherlands from the healthcare providers’ perspective. A total of 59 patients were included, of whom 18 underwent microsurgery, 15 underwent LINAC radiosurgery, and 26 underwent gamma knife radiosurgery. A standardized microcosting methodology was employed to ensure that the identified cost differences would reflect only actual cost differences. Initial treatment costs, using equipment costs per fraction, were €12,288 for microsurgery, €1,547 for LINAC radiosurgery, and €2,412 for gamma knife radiosurgery. Higher initial treatment costs for microsurgery were predominantly due to inpatient stay (€5,321) and indirect costs (€4,350). LINAC and gamma knife radiosurgery were equally expensive when equipment was valued per treatment (€2,198 and €2,412, respectively). Follow-up costs were slightly, but not significantly, higher for microsurgery compared with LINAC and gamma knife radiosurgery. Even though initial treatment costs were over five times higher for microsurgery compared with both radiosurgical treatments, our study gives indications that the relative cost difference may decrease when follow-up costs occurring during the first year after initial treatment are incorporated. This reinforces the need to consider follow-up costs after initial treatment when examining the relative costs of alternative treatments
Shear Stress Modulation of Smooth Muscle Cell Marker Genes in 2-D and 3-D Depends on Mechanotransduction by Heparan Sulfate Proteoglycans and ERK1/2
During vascular injury, vascular smooth muscle cells (SMCs) and fibroblasts/myofibroblasts (FBs/MFBs) are exposed to altered luminal blood flow or transmural interstitial flow. We investigate the effects of these two types of fluid flows on the phenotypes of SMCs and MFBs and the underlying mechanotransduction mechanisms.Exposure to 8 dyn/cm(2) laminar flow shear stress (2-dimensional, 2-D) for 15 h significantly reduced expression of alpha-smooth muscle actin (alpha-SMA), smooth muscle protein 22 (SM22), SM myosin heavy chain (SM-MHC), smoothelin, and calponin. Cells suspended in collagen gels were exposed to interstitial flow (1 cmH(2)O, approximately 0.05 dyn/cm(2), 3-D), and after 6 h of exposure, expression of SM-MHC, smoothelin, and calponin were significantly reduced, while expression of alpha-SMA and SM22 were markedly enhanced. PD98059 (an ERK1/2 inhibitor) and heparinase III (an enzyme to cleave heparan sulfate) significantly blocked the effects of laminar flow on gene expression, and also reversed the effects of interstitial flow on SM-MHC, smoothelin, and calponin, but enhanced interstitial flow-induced expression of alpha-SMA and SM22. SMCs and MFBs have similar responses to fluid flow. Silencing ERK1/2 completely blocked the effects of both laminar flow and interstitial flow on SMC marker gene expression. Western blotting showed that both types of flows induced ERK1/2 activation that was inhibited by disruption of heparan sulfate proteoglycans (HSPGs).The results suggest that HSPG-mediated ERK1/2 activation is an important mechanotransduction pathway modulating SMC marker gene expression when SMCs and MFBs are exposed to flow. Fluid flow may be involved in vascular remodeling and lesion formation by affecting phenotypes of vascular wall cells. This study has implications in understanding the flow-related mechanobiology in vascular lesion formation, tumor cell invasion, and stem cell differentiation
- …