Design and Initial Results of a Multi-Phase Randomized Trial of Ceftriaxone in Amyotrophic Lateral Sclerosis

Objectives: Ceftriaxone increases expression of the astrocytic glutamate transporter, EAAT2, which might protect from glutamate-mediated excitotoxicity. A trial using a novel three stage nonstop design, incorporating Phases I-III, tested ceftriaxone in ALS. Stage 1 determined the cerebrospinal fluid pharmacokinetics of ceftriaxone in subjects with ALS. Stage 2 evaluated safety and tolerability for 20-weeks. Analysis of the pharmacokinetics, tolerability, and safety was used to determine the ceftriaxone dosage for Stage 3 efficacy testing. Methods: In Stage 1, 66 subjects at ten clinical sites were enrolled and randomized equally into three study groups receiving intravenous placebo, ceftriaxone 2 grams daily or ceftriaxone 4 grams daily divided BID. Participants provided serum and cerebrospinal fluid for pharmacokinetic analysis on study day 7. Participants continued their assigned treatment in Stage 2. The Data and Safety Monitoring Board (DSMB) reviewed the data after the last participants completed 20 weeks on study drug. Results: Stage 1 analysis revealed linear pharmacokinetics, and CSF trough levels for both dosage levels exceeding the pre-specified target trough level of 1 µM (0.55 µg/mL). Tolerability (Stages 1 and 2) results showed that ceftriaxone at dosages up to 4 grams/day was well tolerated at 20 weeks. Biliary adverse events were more common with ceftriaxone but not dose-dependent and improved with ursodeoxycholic (ursodiol) therapy. Conclusions: The goals of Stages 1 and 2 of the ceftriaxone trial were successfully achieved. Based on the pre-specified decision rules, the DSMB recommended the use of ceftriaxone 4 g/d (divided BID) for Stage 3, which recently closed. Trial Registration ClinicalTrials.gov NCT00349622

Control of hyperglycaemia in paediatric intensive care (CHiP): study protocol.

BACKGROUND: There is increasing evidence that tight blood glucose (BG) control improves outcomes in critically ill adults. Children show similar hyperglycaemic responses to surgery or critical illness. However it is not known whether tight control will benefit children given maturational differences and different disease spectrum. METHODS/DESIGN: The study is an randomised open trial with two parallel groups to assess whether, for children undergoing intensive care in the UK aged <or= 16 years who are ventilated, have an arterial line in-situ and are receiving vasoactive support following injury, major surgery or in association with critical illness in whom it is anticipated such treatment will be required to continue for at least 12 hours, tight control will increase the numbers of days alive and free of mechanical ventilation at 30 days, and lead to improvement in a range of complications associated with intensive care treatment and be cost effective. Children in the tight control group will receive insulin by intravenous infusion titrated to maintain BG between 4 and 7.0 mmol/l. Children in the control group will be treated according to a standard current approach to BG management. Children will be followed up to determine vital status and healthcare resources usage between discharge and 12 months post-randomisation. Information regarding overall health status, global neurological outcome, attention and behavioural status will be sought from a subgroup with traumatic brain injury (TBI). A difference of 2 days in the number of ventilator-free days within the first 30 days post-randomisation is considered clinically important. Conservatively assuming a standard deviation of a week across both trial arms, a type I error of 1% (2-sided test), and allowing for non-compliance, a total sample size of 1000 patients would have 90% power to detect this difference. To detect effect differences between cardiac and non-cardiac patients, a target sample size of 1500 is required. An economic evaluation will assess whether the costs of achieving tight BG control are justified by subsequent reductions in hospitalisation costs. DISCUSSION: The relevance of tight glycaemic control in this population needs to be assessed formally before being accepted into standard practice

Consistent patterns of common species across tropical tree communities

Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees.Publisher PDFPeer reviewe

Nonsteroidal antiinflammatory drugs in the nephrotic syndrome

In dit proefschrift is een aantal onderzoekingen over de werking van indometacine en soortgelijke antiflogistica - de zogenaamde nonsteroidal antiinflammatory drugs (NSAID's) - op de nierfunktie en eiwituitscheiding in de urine van patienten met eenn efrotisch syndroom gebundeld. ... Zie: Samenvatting

The Clinical Implications of Body Surface Area as a Poor Proxy for Cardiac Output

Background: Prosthesis-patient mismatch (PPM), routinely used to characterize the degree of hemodynamic obstruction caused by a prosthetic heart valve, is associated with adverse patient outcomes after aortic valve replacement (AVR). In the common definition of PPM, the opening area of the valve is related to the patients’ cardiac output, by indexing effective orifice area (EOA) with body surface area (BSA). The aim of this study is to assess the implications of using BSA as a proxy for cardiac output. Methods: 744 patients with normal LV function underwent echocardiographic assessment after surgical AVR. To validate the use of BSA as a proxy for cardiac output, the relation between these variables was analyzed. The effects of BSA on the classification of PPM (EOAi < 0.85 cm2/m2) and the presence of hemodynamic obstruction (mean gradient ≥ 20 mmHg and/or Doppler velocity index < 0.35) were estimated. Results: There was a weak correlation between BSA and cardiac output (r: 0.29, 95% CI: 0.22;0.35), and cardiac output was not proportional to BSA (Cardiac output = 1.5 x BSA +1.9). As a result, the increased risk of patients with a large BSA to be labelled with PPM (OR: 5.2, 95% CI: 2.5,11 per m2 BSA), was not reflected by a significantly higher risk of hemodynamic obstruction (OR: 1.5, 95% CI: 0.5,4.9 per m2 BSA). Conclusions: The current definition of PPM results in a systematic overestimation of hemodynamic obstruction in patients with a larger BSA, and we recommend cautious use in this subgroup. Abbreviations: AVR: Aortic valve replacement; BMI: Body mass index; BSA: Body surface area; EOA: Effective orifice area; EOAi: Indexed effective orifice area; LVOT: Left ventricular outflow tract; PERIGON: PERIcardial SurGical AOrtic Valve ReplacemeNt Pivotal Trial; PPM: Prosthesis-patient mismatch; TTE: Transthoracic echocardiography; VARC-2: Valve Academic Research Consortium-2