Orthostatic intolerance in adolescent chronic fatigue syndrome

OBJECTIVES: To demonstrate the association between orthostatic intolerance and the chronic fatigue syndrome (CFS) in adolescents and to delineate the form that orthostatic intolerance takes in these children. STUDY DESIGN: We investigated the heart rate and blood pressure (BP) responses to head-up tilt (HUT) in 26 adolescents aged 11 to 19 years with CFS compared with responses in adolescents referred for the evaluation of simple faint and to responses in 13 normal healthy control children of similar age. RESULTS: A total of 4/13 of the controls and 18/26 simple faint patients experienced typical faints with an abrupt decrease in BP and heart rate associated with loss of consciousness. One CFS patient had a normal HUT. A total of 25/26 CFS patients experienced severe orthostatic symptoms associated with syncope in 7/25, orthostatic tachycardia with hypotension in 15/25, and orthostatic tachycardia without significant hypotension in 3/25. Acrocyanosis, cool extremities, and edema indicated venous pooling in 18/25. None of the control or simple faint patients experienced comparable acral or tachycardic findings. CONCLUSIONS: We conclude that chronic fatigue syndrome is highly related to orthostatic intolerance in adolescents. The orthostatic intolerance of CFS often has heart rate and BP responses similar to responses in the syndrome of orthostatic tachycardia suggesting that a partial autonomic defect may contribute to symptomatology in these patients.     

COVID-19 vaccine effectiveness against SARS-CoV-2 infection during the Delta period,a nationwide study adjusting for chance of exposure,the Netherlands,July to December 2021

BackgroundDifferential SARS-CoV-2 exposure between vaccinated and unvaccinated individuals may confound vaccine effectiveness (VE) estimates.AimWe conducted a test-negative case–control study to determine VE against SARS-CoV-2 infection and the presence of confounding by SARS-CoV-2 exposure.MethodsWe included adults tested for SARS-CoV-2 at community facilities between 4 July and 8 December 2021 (circulation period of the Delta variant). The VE against SARS-CoV-2 infection after primary vaccination with an mRNA (Comirnaty or Spikevax) or vector-based vaccine (Vaxzevria or Janssen) was calculated using logistic regression adjusting for age, sex and calendar week (Model 1). We additionally adjusted for comorbidity and education level (Model 2) and SARS-CoV-2 exposure (number of close contacts, visiting busy locations, household size, face mask wearing, contact with SARS-CoV-2 case; Model 3). We stratified by age, vaccine type and time since vaccination.ResultsVE against infection (Model 3) was 64% (95% CI: 50–73), only slightly lower than in Models 1 (68%; 95% CI: 58–76) and 2 (67%; 95% CI: 56–75). Estimates stratified by age group, vaccine and time since vaccination remained similar: mRNA VE (Model 3) among people ≥ 50 years decreased significantly (p = 0.01) from 81% (95% CI: 66–91) at < 120 days to 61% (95% CI: 22–80) at ≥ 120 days after vaccination. It decreased from 83% to 59% in Model 1 and from 81% to 56% in Model 2.ConclusionSARS-CoV-2 exposure did not majorly confound the estimated COVID-19 VE against infection, suggesting that VE can be estimated accurately using routinely collected data without exposure information.     

Quantitative kinetic modelling and mapping of cerebral glucose transport and metabolism using glucoCESL MRI

Chemical-exchange spin-lock (CESL) MRI can map regional uptake and utilisation of glucose in the brain at high spatial resolution (i.e sub 0.2 mm³ voxels). We propose two quantitative kinetic models to describe glucose-induced changes in tissue R_1ρ and apply them to glucoCESL MRI data acquired in tumour-bearing and healthy rats. When assuming glucose transport is saturable, the maximal transport capacity (T_max) measured in normal tissue was 3.2 ± 0.6 µmol/min/mL, the half saturation constant (K_t) was 8.8 ± 2.2 mM, the metabolic rate of glucose consumption (MR_glc) was 0.21 ± 0.13 µmol/min/mL, and the cerebral blood volume (v_b) was 0.006 ± 0.005 mL/mL. Values in tumour were: T_max = 7.1 ± 2.7 µmol/min/mL, K_t = 14 ± 1.7 mM, MR_glc = 0.22 ± 0.09 µmol/min/mL, v_b = 0.030 ± 0.035 mL/mL. T_max and K_t were significantly higher in tumour tissue than normal tissue (p = 0.006 and p = 0.011, respectively). When assuming glucose uptake also occurs via free diffusion, the free diffusion rate (k_d) was 0.061 ± 0.017 mL/min/mL in normal tissue and 0.12 ± 0.042 mL/min/mL in tumour. These parameter estimates agree well with literature values obtained using other approaches (e.g. NMR spectroscopy).     

腰椎间盘突出伴侧隐窝狭窄症的微创治疗破

0引言 腰椎间盘突出症伴侧隐窝狭窄症目前最有效的方法依然是椎间盘突出髓核摘除及神经根通道减压清理术. 如何减少创伤,保持脊柱稳定,尽快康复,以最少的并发症和最低的经济负担,获得优良的中远期疗效一直是脊柱外科的目标[1-3]. 2000-09/2004-03我院开展显微内窥镜椎间盘切除(MED)手术375例,其中120例有椎间盘突出伴侧隐窝狭窄,进行椎间盘摘除及神经根通道清理术. 现将随访到的98例作一短中期疗效的总结报道.     

Infliximab decreases inflammatory activity but has no effect on small fiber neuropathy related symptoms in Dutch patients with sarcoidosis

Background and aim:Small fiber neuropathy (SFN) may present as complication in sarcoidosis. SFN can potentially result into a large range of symptoms with a high impact on quality of life. Although treatment of the underlying disease of SFN is paramount, little research has been performed to investigate SFN improvement as consequence of sarcoidosis treatment. This retrospective study investigates whether there is an association between the anti-inflammatory effects of infliximab and SFN-symptomsMethods:The Small Fiber Neuropathy Screening List (SFNSL) was used to measure changes in SFN symptoms during infliximab treatment. Maximal standardized uptake value (SUVmax) from Fluordeoxyglucose Positron Emission Tomography (FDG-PET) was used as a measure for inflammatory activityResults:36 sarcoidosis patients were eligible for analysis. SFNSL-score showed a mean decrease of -1,9 points (p = 0.446). SUVmax did improve with a mean of -3.7 (p<0.001). No correlation between a decrease of SUVmax and SFNSL screening list could be found (p=0.610)Conclusions:Our data reveal no association between anti-inflammatory effect of infliximab and SFN-related symptoms in patients with sarcoidosis, which contradicts previous case-reports and case-series. Given the major negative impact of SFN-related symptoms on the quality of life in patients with sarcoidosis, it is necessary that the possible beneficial effect of anti-inflammatory therapy will be further addressed in future prospective studies.     

Aqueous/non-aqueous electrolyte tradeoffs in charge transfer and electrochromics of pseudocapacitive oxide films

Environmental sustainability, safety, cost, and performance are the driving metrics for modern technological developments. Progress in these realms has been made for electrochromic (EC) devices by optimizing anode/cathode electrode materials. Yet, by these standards, the role of the electrolyte has remained unexplored. This investigation on charge transfer mechanisms at the electrolyte/electrode interface facilitates a contrast of the aqueous and non-aqueous electrolytes studied. A classic EC, high-performing, non-aqueous, lithium chlorine oxide in propylene carbonate (PC-LiClO₄) is examined against a non-flammable, low reactive, cost-effective, aqueous, potassium hydroxide (KOH) electrolyte; to strengthen the understanding of electrochromics the electrolytes are referenced against the anodic EC nickel oxide (NiO) thin films. The KOH presents as a diffusion dominant response, supported by the findings of the cyclic voltammetry and electrochemistry impedance data (b = 0.56, 45°∠), respectively, compared to the more surface capacitive PC-LiClO₄ (b = 0.68, 60°∠). Interestingly, despite the KOH full redox potential window being half the PC-LiClO₄, the KOH system''s current density reached more than 3 times higher than PC-LiClO₄. Additionally, realizing the same current density (2 mA cm⁻²) in multi-step chronoamperometry, the required potential is ∼5 times lower for KOH than for PC-LiClO₄ electrolyte, albeit the KOH has a longer response time. Inherent tradeoffs in the systems are considered for theoretical analysis of these phenomena, i.e., molar mass, ionization energy, viscosity, etc. The chemical nature of the electrolyte shows a profound effect on electrochemical kinetics at the NiO/electrolyte interface, pointing to the significance of all aspects in an electrochemical cell. The coupled effect of the electrolyte composition/electrode material pairing dictates the charge-storage mechanisms (and subsequently, EC properties). Furthermore, knowledge of contrasts in electrolyte type is of great interest to the scientific community for the modern metric-based optimizations of many other clean energy systems.

Environmental sustainability, safety, cost, and performance are the driving metrics for modern technological developments.     

Educational objectives and requirements of an undergraduate clerkship in general practice. The outcome of a consensus procedure

OBJECTIVES: The main aim of this study was to reach consensus between students, faculty and general practice teachers on the educational objectives and requirements of the clerkship in general practice. METHOD: The consensus procedure consisted of four steps and all active general practice teachers (n = 116) were asked to participate in the study. RESULTS: We identified 189 educational objectives: 127 complaints (problems, symptoms, syndromes), 29 clinical skills and 37 objectives concerning the theoretical dimensions of general practice. Educational requirements crystallized to 16 essential preconditions of a teaching practice and 35 didactic activities to be performed by the general practice teachers. CONCLUSIONS: These consensus results will be used to structure the medical curriculum and as guidelines for the educational process during the clerkship.