Quantitatieve permeabiliteitsbepalingen

Permeability of cell membranes of pressed baker's yeast was estimated by estimating the decline in concentration of the permeating substance. Therefore it was necessary to know the amount of water imbibed in the cell walls, the free water in the cells, and the imbibed water of the dispersed colloidal phase (protoplasm) in the cells.With correction for the dispersed colloidal phase, the yeast cells behaved according to the law of Boyle Mariotte van 't Hoff. The uptake of substances by yeast cells was estimated chemically. Inorganic cations and anions were taken up according to lyotropic range, Ca 2+ Uptake of organic acids depended closely on their degree of dissociation. Of the sugars tested lactose did not permeate, whereas glucose was rapidly adsorbed by the cell surface. Some substances were adsorbed by the disperse phase (K + and urea)

Tocilizumab in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Background: In this study, we aimed to evaluate the effects of tocilizumab in adult patients admitted to hospital with COVID-19 with both hypoxia and systemic inflammation. Methods: This randomised, controlled, open-label, platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing several possible treatments in patients hospitalised with COVID-19 in the UK. Those trial participants with hypoxia (oxygen saturation <92% on air or requiring oxygen therapy) and evidence of systemic inflammation (C-reactive protein ≥75 mg/L) were eligible for random assignment in a 1:1 ratio to usual standard of care alone versus usual standard of care plus tocilizumab at a dose of 400 mg–800 mg (depending on weight) given intravenously. A second dose could be given 12–24 h later if the patient's condition had not improved. The primary outcome was 28-day mortality, assessed in the intention-to-treat population. The trial is registered with ISRCTN (50189673) and ClinicalTrials.gov (NCT04381936). Findings: Between April 23, 2020, and Jan 24, 2021, 4116 adults of 21 550 patients enrolled into the RECOVERY trial were included in the assessment of tocilizumab, including 3385 (82%) patients receiving systemic corticosteroids. Overall, 621 (31%) of the 2022 patients allocated tocilizumab and 729 (35%) of the 2094 patients allocated to usual care died within 28 days (rate ratio 0·85; 95% CI 0·76–0·94; p=0·0028). Consistent results were seen in all prespecified subgroups of patients, including those receiving systemic corticosteroids. Patients allocated to tocilizumab were more likely to be discharged from hospital within 28 days (57% vs 50%; rate ratio 1·22; 1·12–1·33; p<0·0001). Among those not receiving invasive mechanical ventilation at baseline, patients allocated tocilizumab were less likely to reach the composite endpoint of invasive mechanical ventilation or death (35% vs 42%; risk ratio 0·84; 95% CI 0·77–0·92; p<0·0001). Interpretation: In hospitalised COVID-19 patients with hypoxia and systemic inflammation, tocilizumab improved survival and other clinical outcomes. These benefits were seen regardless of the amount of respiratory support and were additional to the benefits of systemic corticosteroids. Funding: UK Research and Innovation (Medical Research Council) and National Institute of Health Research

Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial

Background: Many patients with COVID-19 have been treated with plasma containing anti-SARS-CoV-2 antibodies. We aimed to evaluate the safety and efficacy of convalescent plasma therapy in patients admitted to hospital with COVID-19. Methods: This randomised, controlled, open-label, platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]) is assessing several possible treatments in patients hospitalised with COVID-19 in the UK. The trial is underway at 177 NHS hospitals from across the UK. Eligible and consenting patients were randomly assigned (1:1) to receive either usual care alone (usual care group) or usual care plus high-titre convalescent plasma (convalescent plasma group). The primary outcome was 28-day mortality, analysed on an intention-to-treat basis. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936. Findings: Between May 28, 2020, and Jan 15, 2021, 11558 (71%) of 16287 patients enrolled in RECOVERY were eligible to receive convalescent plasma and were assigned to either the convalescent plasma group or the usual care group. There was no significant difference in 28-day mortality between the two groups: 1399 (24%) of 5795 patients in the convalescent plasma group and 1408 (24%) of 5763 patients in the usual care group died within 28 days (rate ratio 1·00, 95% CI 0·93–1·07; p=0·95). The 28-day mortality rate ratio was similar in all prespecified subgroups of patients, including in those patients without detectable SARS-CoV-2 antibodies at randomisation. Allocation to convalescent plasma had no significant effect on the proportion of patients discharged from hospital within 28 days (3832 [66%] patients in the convalescent plasma group vs 3822 [66%] patients in the usual care group; rate ratio 0·99, 95% CI 0·94–1·03; p=0·57). Among those not on invasive mechanical ventilation at randomisation, there was no significant difference in the proportion of patients meeting the composite endpoint of progression to invasive mechanical ventilation or death (1568 [29%] of 5493 patients in the convalescent plasma group vs 1568 [29%] of 5448 patients in the usual care group; rate ratio 0·99, 95% CI 0·93–1·05; p=0·79). Interpretation: In patients hospitalised with COVID-19, high-titre convalescent plasma did not improve survival or other prespecified clinical outcomes. Funding: UK Research and Innovation (Medical Research Council) and National Institute of Health Research

Legal framework for food fortification : examples from Vietnam and Indonesia

Background. Food fortification is a cost-effective, powerful, and sustainable strategy to combat micronutrient deficiency, with the potential to reach large sections of the population with minimal cost and effort. However, the implementation of food fortification on a systematic and large scale, for instance in national programs, has often been challenging. Objective. This paper takes a closer look at food fortification efforts and legislation mechanisms in Vietnam and Indonesia in order to determine specific factors and components in the legal framework that are crucial to the success of fortification programs, Methods. Fortification efforts in Indonesia and Vietnam are evaluated using published data as well as unpublished data from detailed evaluation reports, and compared with respect to the specific circumstances, constraints, objectives and results in each country. Results. The legal framework is a crucial factor for the success of food fortification programs, as it shapes to a large extent the implementation of food fortification. The legal framework is instrumental to ensure the quality, safety, availability, cost-effectiveness, and sustainability of food fortification. In the first place, the legal framework should specify the fortificants and fortification levels, as well as the food vehicles and the fortification procedures. In addition, it should ensure the commitment of policy makers and producers to fortification, regulate the costing, describe and ensure information and communication such as product labeling, integrate social marketing into the implementation, and provide the means to monitor and enforce fortification. A clear public health objective, together with careful consideration of the choices and restrictions dictated by the specific national environments, will help to develop legal frameworks that optimize the potential success of food fortification strategies. Conclusions. The lessons from these experiences show that a mandatory approach to fortification, with costing, monitoring and enforcement, and social marketing clearly defined and well embedded in the legal framework and in the implementation structures, is the best foundation for an effective, sustainable, and feasible food fortification program