Continuous wave optical parametric oscillator for quartz-enhanced photoacoustic trace gas sensing

A continuous wave optical parametric oscillator, generating up to 300 mW idler output in the 3–4 μm wavelength region, and pumped by a fiber-amplified DBR diode laser is used for trace gas detection by means of quartz-enhanced photoacoustic spectroscopy (QEPAS). Mode-hop-free tuning of the OPO output over 5.2 cm-1 and continuous spectral coverage exceeding 16.5 cm-1 were achieved via electronic pump source tuning alone. Online monitoring of the idler wavelength, with feedback to the DBR diode laser, provided an automated closed-loop control allowing arbitrary idler wavelength selection within the pump tuning range and locking of the idler wavelength with a stability of 1.7×10-3 cm-1 over at least 30 min.\ud \ud Using this approach, we locked the idler wavelength at an ethane absorption peak and obtained QEPAS data to verify the linear response of the QEPAS signal at different ethane concentrations (100 ppbv-20 ppmv) and different power levels. The detection limit for ethane was determined to be 13 ppbv (20 s averaging), corresponding to a normalized noise equivalent absorption coefficient of 4.4×10-7 cm-1  W/Hz1/2

Comparing the Efficacy of Bevacizumab and Ranibizumab in Patients with Diabetic Macular Edema (BRDME):The BRDME Study, a Randomized Trial

Purpose: To generate conclusive evidence regarding the noninferiority of intravitreal bevacizumab compared with ranibizumab in patients with diabetic macular edema (DME). Design: Comparative, randomized, double-masked, multicenter, noninferiority clinical trial. Participants: Eligible patients were older than 18 years, diagnosed with type 1 or type 2 diabetes mellitus, with glycosylated hemoglobin of less than 12%, central area thickness of more than 325 μm, and visual impairment from DME with a best-corrected visual acuity (BCVA) between 24 letters and 78 letters. Methods: From June 2012 through February 2018, a total of 170 participants were randomized to receive 6 monthly injections of either 1.25 mg bevacizumab (n = 86) or 0.5 mg ranibizumab (n = 84). Main Outcome Measures: Primary outcome was change in BCVA from baseline to month 6 compared between the 2 treatment arms. The noninferiority margin was 3.5 letters. Results: The difference in mean BCVA between treatment arms was 1.8 letters in favor of ranibizumab after 6 months of follow-up; BCVA improved by 4.9±6.7 letters in the bevacizumab group and 6.7±8.7 letters in the ranibizumab group. The lower bound of the 2-sided 90% confidence interval (CI) was –3.626 letters, exceeding the noninferiority margin of 3.5 letters. Central area thickness decreased more with ranibizumab (138.2±114.3 μm) compared with bevacizumab (64.2±104.2 μm). In a post hoc subgroup analysis, participants with a worse BCVA at baseline (≤69 letters) improved by 6.7±7.0 letters with bevacizumab and 10.4±10.0 letters with ranibizumab, and central area thickness decreased significantly more in the ranibizumab arm of this subgroup compared with the bevacizumab arm. Participants with an initially better BCVA at baseline (≥70 letters) did not demonstrate differences in BCVA or OCT outcomes between treatment arms. Conclusions: Based on change in BCVA from baseline to month 6, the noninferiority of 1.25 mg bevacizumab to 0.5 mg ranibizumab was not confirmed. Only the subgroup of patients with a lower BCVA at baseline showed better visual acuity and anatomic outcomes with ranibizumab. Our study confirmed the potential differential efficacy of anti–vascular endothelial growth factor agents in the treatment of DME as well as the difference in response between patient groups with different baseline visual acuities

Comparing the Efficacy of Bevacizumab and Ranibizumab in Patients with Retinal Vein Occlusion:The Bevacizumab to Ranibizumab in Retinal Vein Occlusions (BRVO) study, a Randomized Trial

PURPOSE: Comparing the efficacy of intravitreal injections of bevacizumab to ranibizumab in the treatment of macular edema (ME) resulting from retinal vein occlusion (RVO). DESIGN: Comparative, randomized, double-masked, multicenter, noninferiority clinical trial. The noninferiority margin was 4 letters. PARTICIPANTS: Patients with vision loss resulting from ME secondary to a branch or (hemi) central RVO who might benefit from anti-vascular endothelial growth factor treatment were eligible for participation. METHODS: From June 2012 through February 2018, 277 participants were randomized to receive injections of 1.25 mg bevacizumab (n = 139) or 0.5 mg ranibizumab (n = 138). The follow-up was 6 months with a monthly dosing interval. MAIN OUTCOME MEASURES: The primary outcome was a change in visual acuity from baseline at 6 months. Changes in the central area thickness and safety were studied as secondary outcomes. RESULTS: The mean visual acuity (±standard deviation) improved, with 15.3±13.0 letters for bevacizumab and 15.5±13.3 letters for ranibizumab after 6 months of monthly treatment. The lower limit of the 2-sided 90% confidence interval was -1.724 letters, which is within the noninferiority margin of 4 letters. Even in the branch and (hemi-)central RVO subgroups, minimal differences were found in visual acuity outcomes between treatment arms. Changes in central area thickness on OCT at 6 months did not differ significantly between treatment groups, with a decrease of 287.0±231.3 μm in the bevacizumab group and 300.8±224.8 μm in the ranibizumab group. Severe adverse events (SAEs) were also distributed equally over both treatment groups: 10 participants (7.1%) in the bevacizumab group and 13 participants (9.2%) in the ranibizumab group experienced SAEs. CONCLUSIONS: This study showed, based on the change in visual acuity, that bevacizumab is noninferior to ranibizumab for patients with ME resulting from RVO of either subtype when receiving monthly injections for a period of 6 months. In addition, anatomic and safety outcomes did not differ between treatment groups. Based on our findings, bevacizumab may be an effective alternative to ranibizumab

Optimising Psychoeducation for Transient Ischaemic Attack and Minor Stroke Management (OPTIMISM): Protocol for a feasibility randomised controlled trial

Background: A transient ischaemic attack (TIA) and minor stroke are medical emergencies and often a warning sign of future strokes if remain untreated. Few studies have investigated the long-term psychosocial effects of TIA and minor stroke. Secondary prevention and medical management are often the primary focus with limited access offered for further psychosocial support. Psychoeducational interventions can provide education and advice to people with physical health conditions and, with suitable tailoring, could be appropriate for people after TIA and minor stroke. This study aims to develop a group psychoeducational intervention for people after TIA and minor stroke and to test whether it is acceptable and feasible. Methods: This mixed-methodology study involves two phases: Phase 1) A qualitative study to determine the content of a suitable intervention; Phase 2) A single-centre feasibility randomised controlled trial to evaluate the acceptability of this intervention. The overall study has ethical approval. Stroke survivors have been involved in designing and monitoring the trial. The aim is to recruit 30-40 participants from a Stroke/TIA Service, within 6 months following their diagnosis. Participants will be randomly allocated to either the usual care control group or the intervention group (psychoeducational programme). The programme will consist of six group sessions based on providing education, psychological and social support. The primary outcomes will relate to the feasibility aims of the study. Outcomes will be collected at 3 and 6 months to assess mood, quality of life, knowledge and satisfaction, and resource use. Discussion: There is a need to develop and evaluate effective interventions that enhance the education provided to people after TIA and minor stroke and to promote their psychosocial wellbeing. Findings will indicate the acceptability of the intervention and parameters needed to conduct a definitive trial

The EMIF-AD PreclinAD study: study design and baseline cohort overview

BACKGROUND: Amyloid pathology is the pathological hallmark in Alzheimer’s disease (AD) and can precede clinical dementia by decades. So far it remains unclear how amyloid pathology leads to cognitive impairment and dementia. To design AD prevention trials it is key to include cognitively normal subjects at high risk for amyloid pathology and to find predictors of cognitive decline in these subjects. These goals can be accomplished by targeting twins, with additional benefits to identify genetic and environmental pathways for amyloid pathology, other AD biomarkers, and cognitive decline. METHODS: From December 2014 to October 2017 we enrolled cognitively normal participants aged 60 years and older from the ongoing Manchester and Newcastle Age and Cognitive Performance Research Cohort and the Netherlands Twins Register. In Manchester we included single individuals, and in Amsterdam monozygotic twin pairs. At baseline, participants completed neuropsychological tests and questionnaires, and underwent physical examination, blood sampling, ultrasound of the carotid arteries, structural and resting state functional brain magnetic resonance imaging, and dynamic amyloid positron emission tomography (PET) scanning with [18F]flutemetamol. In addition, the twin cohort underwent lumbar puncture for cerebrospinal fluid collection, buccal cell collection, magnetoencephalography, optical coherence tomography, and retinal imaging. RESULTS: We included 285 participants, who were on average 74.8 ± 9.7 years old, 64% female. Fifty-eight participants (22%) had an abnormal amyloid PET scan. CONCLUSIONS: A rich baseline dataset of cognitively normal elderly individuals has been established to estimate risk factors and biomarkers for amyloid pathology and future cognitive declin

Cognitive function and drivers of cognitive impairment in a European and a Korean cohort of people living with HIV

Although cognitive impairments are still prevalent in the current antiretroviral therapy era, limited investigations have compared the prevalence of cognitive disorder in people living with HIV (PLWH) and its determinants in different regions and ethnicities. We compared cognitive performance across six domains using comparable batteries in 134 PLWH aged ≥45 years from the COBRA study (Netherlands, UK), and 194 PLWH aged ≥18 years from the NeuroAIDS Project (South Korea). Cognitive scores were standardized and averaged to obtain domain and global T-scores. Associations with global T-scores were evaluated using multivariable regression and the ability of individual tests to detect cognitive impairment (global T-score ≤45) was assessed using the area-under-the-receiver-operating-characteristic curve (AUROC). The median (interquartile range) age of participants was 56 (51, 62) years in COBRA (88% white ethnicity, 93% male) and 45 (37, 52) years in NeuroAIDS (100% Korean ethnicity, 94% male). The rate of cognitive impairment was 18.8% and 18.0%, respectively (p = 0.86). In COBRA, Black-African ethnicity was the factor most strongly associated with cognitive function (11.1 [7.7, 14.5] lower scores vs. white ethnicity, p < 0.01), whereas in NeuroAIDS, age (0.6 [0.1, 1.3] per 10-year, p<0.01) and education (0.7 [0.5, 0.9] per year, p<0.01) were significantly associated with cognitive function with anemia showing only a weak association (−1.2 [−2.6, 0.3], p=0.12). Cognitive domains most associated with cognitive impairment were attention (AUROC = 0.86) and executive function (AUROC = 0.87) in COBRA and processing speed (AUROC = 0.80), motor function (AUROC = 0.78) and language (AUROC = 0.78) in NeuroAIDS. Two cohorts of PLWH from different geographical regions report similar rates of cognitive impairment but different risk factors and cognitive profiles of impairment

Red ROM als kwaliteitsinstrument

In het recent verschenen rapport over de bekostiging van de curatieve ggz concludeert de Algemene Rekenkamer (2017): ‘informatie die met ROM [routine outcome monitoring] wordt verkregen, heeft beperkingen en is van onvoldoende kwaliteit om te dienen als sturingsinformatie bij de zorginkoop’ (p. 14). Dit rapport is door een groep psychiaters en psychologen aangegrepen om de petitie ‘Stop benchmark met ROM’ (www.stoprom.com) in het leven te roepen, die inmiddels door ruim 6000 mensen getekend is. In dit artikel reageren wij op deze petitie. Wij onderschrijven dat ROM geen basis mag zijn voor zorginkoop, maar vinden dat ROM en benchmarking van grote waarde kunnen zijn voor het verbeteren van de kwaliteit van de behandeling en pleiten daarom voor inhoudelijke doorontwikkeling van benchmarking in plaats van deze te stoppen