Methemoglobin formation in mutant hemoglobin α chains: electron transfer parameters and rates

Hemoglobin-mediated transport of dioxygen (O2) critically depends on the stability of the reduced (Fe2+) form of the heme cofactors. Some protein mutations stabilize the oxidized (Fe3+) state (methemoglobin, Hb M), causing methemoglobinemia, and can be lethal above 30%. The majority of the analyses of factors influencing Hb oxidation are retrospective and give insights only for inner-sphere mutations of heme (His58, His87). Herein, we report the first all-atom molecular dynamics simulations on both redox states and calculations of the Marcus electron transfer (ET) parameters for the α chain Hb oxidation and reduction rates for Hb M. The Hb wild-type (WT) and most of the studied α chain variants maintain globin structure except the Hb M Iwate (H87Y). The mutants forming Hb M tend to have lower redox potentials and thus stabilize the oxidized (Fe3+) state (in particular, the Hb Miyagi variant with K61E mutation). Solvent reorganization (λsolv 73–96%) makes major contributions to reorganization free energy, whereas protein reorganization (λprot) accounts for 27–30% except for the Miyagi and J-Buda variants (λprot ∼4%). Analysis of heme-solvent H-bonding interactions among variants provide insights into the role of Lys61 residue in stabilizing the Fe2+ state. Semiclassical Marcus ET theory-based calculations predict experimental kET for the Cyt b5-Hb complex and provide insights into relative reduction rates for Hb M in Hb variants. Thus, our methodology provides a rationale for the effect of mutations on the structure, stability, and Hb oxidation reduction rates and has potential for identification of mutations that result in methemoglobinemia

An Educational Interventional Study to Assess Awareness about Mosquito Breeding, Diseases Caused and Protective Measures Against them among Families Residing in an Urban Slum of Indore City

Background: Community participation plays an important role in control of Mosquito borne diseases. This study tries to assess impact of educational intervention on various aspects of mosquito borne diseases in an urban slum. Methodology: An educational interventional study was done in 200 families residing in a slum (Badi Gwaltoli) which is in field practice area of Urban Health Centre attached to Department of Community Medicine of M.G.M.Medical College, Indore. A pretested semi-structured questionnaire was administered to the Head of the family which studied their awareness and perception regarding breeding sites and biting habits of mosquitoes, diseases spread by them and personal protective measures used, followed by an educational intervention and post assessment. Data was entered into Microsoft excel spread sheet and analysed using SPSS version 20 software. Results: 46% of study population knew the correct breeding season of mosquitoes (monsoon season) during pre-intervention and 68% of the population post- intervention (p- value 0.004). When asked at what time mosquitoes bite the most, maximum number (92%) of people said that mosquitoes bite most in the evening and night, while only 6% and 2% were for morning and noon, respectively. Only 3.5% of the population who knew about breeding sites knew about artificial collections of water. Majority said mosquito breed in dirty stagnant water (78.5%). About 96%of the study population was aware that mosquitoes spread diseases. However, only 33.3%of respondents knew correctly about the diseases spread which improved to 68% in the post-intervention period (p-value=.000). 46% knew all the protection measures against mosquitoes in the pre-intervention which increased to 86% in the post intervention (p.value-.005). Conclusion: Awareness about Aedes mosquitoes and its habits is quite poor and many people still believe that only dirty water serves as a breeding place in mosquitoes. Regular IEC sessions informing community about mosquito-borne diseases will improve community participation

A Repurposing Programme Evaluating Repurposing Transdermal Oestradiol Patches for the Treatment of Prostate Cancer Within the PATCH and STAMPEDE Trials: Current Results and Adapting Trial Design

AIMS: Androgen deprivation therapy (ADT), usually achieved with luteinising hormone releasing hormone analogues (LHRHa), is central to prostate cancer management. LHRHa reduce both testosterone and oestrogen and are associated with significant long-term toxicity. Previous use of oral oestrogens as ADT was curtailed because of cardiovascular toxicity. Transdermal oestrogen (tE2) patches are a potential alternative ADT, supressing testosterone without the associated oestrogen-depletion toxicities (osteoporosis, hot flushes, metabolic abnormalities) and avoiding cardiovascular toxicity, and we here describe their evaluation in men with prostate cancer. MATERIALS AND METHODS: The PATCH (NCT00303784) adaptive trials programme (incorporating recruitment through the STAMPEDE [NCT00268476] platform) is evaluating the safety and efficacy of tE2 patches as ADT for men with prostate cancer. An initial randomised (LHRHa versus tE2) phase II study (n = 251) with cardiovascular toxicity as the primary outcome measure has expanded into a phase III evaluation. Those with locally advanced (M0) or metastatic (M1) prostate cancer are eligible. To reflect changes in both management and prognosis, the PATCH programme is now evaluating these cohorts separately. RESULTS: to date: Recruitment is complete, with 1362 and 1128 in the M0 and M1 cohorts, respectively. Rates of androgen suppression with tE2 were equivalent to LHRHa, with improved metabolic parameters, quality of life and bone health indices (mean absolute change in lumbar spine bone mineral density of -3.0% for LHRHa and +7.9% for tE2 with an estimated difference between arms of 9.3% (95% confidence interval 5.3-13.4). Importantly, rates of cardiovascular events were not significantly different between the two arms and the time to first cardiovascular event did not differ between treatment groups (hazard ratio 1.11, 95% confidence interval 0.80-1.53; P = 0.54). Oncological outcomes are awaited. FUTURE: Efficacy results for the M0 cohort (primary outcome measure metastases-free survival) are expected in the final quarter of 2023. For M1 patients (primary outcome measure - overall survival), analysis using restricted mean survival time is being explored. Allied translational work on longitudinal samples is underway

Formulation, characterisation and stabilisation of buccal films for paediatric drug delivery of omeprazole

This study aimed to develop films for potential delivery of omeprazole (OME) via the buccal mucosa of paediatric patients. Films were prepared using hydroxypropylmethylcellulose (HPMC), methylcellulose (MC), sodium alginate (SA), carrageenan (CA) and metolose (MET) with polyethylene glycol (PEG 400) as plasticiser, OME (model drug) and L-arg (stabiliser). Gels (1% w/w) were prepared at 40°C using water and ethanol with PEG 400 (0–1% w/w) and dried in an oven (40°C). Optimised formulations containing OME and L-arg (1:1, 1:2 and 1:3) were prepared to investigate the stabilisation of the drug. Tensile properties (Texture analysis, TA), physical form (differential scanning calorimetry, DSC; X-ray diffraction, XRD; thermogravimetric analysis, TGA) and surface topography (scanning electron microscopy, SEM) were investigated. Based on the TA results, SA and MET films were chosen for OME loading and stabilisation studies as they showed a good balance between flexibility and toughness. Plasticised MET films were uniform and smooth whilst unplasticised films demonstrated rough lumpy surfaces. SA films prepared from aqueous gels showed some lumps on the surface, whereas SA films prepared from ethanolic gels were smooth and uniform. Drug-loaded gels showed that OME was unstable and therefore required addition of L-arg. The DSC and XRD suggested molecular dispersion of drug within the polymeric matrix. Plasticised (0.5% w/w PEG 400) MET films prepared from ethanolic (20% v/v) gels and containing OME: L-arg 1:2 showed the most ideal characteristics (transparency, ease of peeling and flexibility) and was selected for further investigation

Designing bus transit services for routine crowd situations at large event venues

National Research Foundation (NRF) Singapore under International Research Centres in Singapore Funding Initiativ

Transdermal oestradiol for androgen suppression in prostate cancer: long-term cardiovascular outcomes from the randomised Prostate Adenocarcinoma Transcutaneous Hormone (PATCH) trial programme

Background: Androgen suppression is a central component of prostate cancer management but causes substantial long-term toxicity. Transdermal administration of oestradiol (tE2) circumvents first-pass hepatic metabolism and, therefore, should avoid the cardiovascular toxicity seen with oral oestrogen and the oestrogen-depletion effects seen with luteinising hormone releasing hormone agonists (LHRHa). We present long-term cardiovascular follow-up data from the Prostate Adenocarcinoma Transcutaneous Hormone (PATCH) trial programme. Methods: PATCH is a seamless phase 2/3, randomised, multicentre trial programme at 52 study sites in the UK. Men with locally advanced or metastatic prostate cancer were randomly allocated (1:2 from August, 2007 then 1:1 from February, 2011) to either LHRHa according to local practice or tE2 patches (four 100 μg patches per 24 h, changed twice weekly, reducing to three patches twice weekly if castrate at 4 weeks [defined as testosterone ≤1·7 nmol/L]). Randomisation was done using a computer-based minimisation algorithm and was stratified by several factors, including disease stage, age, smoking status, and family history of cardiac disease. The primary outcome of this analysis was cardiovascular morbidity and mortality. Cardiovascular events, including heart failure, acute coronary syndrome, thromboembolic stroke, and other thromboembolic events, were confirmed using predefined criteria and source data. Sudden or unexpected deaths were attributed to a cardiovascular category if a confirmatory post-mortem report was available and as other relevant events if no post-mortem report was available. PATCH is registered with the ISRCTN registry, ISRCTN70406718; the study is ongoing and adaptive. Findings: Between Aug 14, 2007, and July 30, 2019, 1694 men were randomly allocated either LHRHa (n=790) or tE2 patches (n=904). Overall, median follow-up was 3·9 (IQR 2·4–7·0) years. Respective castration rates at 1 month and 3 months were 65% and 93% among patients assigned LHRHa and 83% and 93% among those allocated tE2. 157 events from 145 men met predefined cardiovascular criteria, with a further ten sudden deaths with no post-mortem report (total 167 events in 153 men). 26 (2%) of 1694 patients had fatal cardiovascular events, 15 (2%) of 790 assigned LHRHa and 11 (1%) of 904 allocated tE2. The time to first cardiovascular event did not differ between treatments (hazard ratio 1·11, 95% CI 0·80–1·53; p=0·54 [including sudden deaths without post-mortem report]; 1·20, 0·86–1·68; p=0·29 [confirmed group only]). 30 (34%) of 89 cardiovascular events in patients assigned tE2 occurred more than 3 months after tE2 was stopped or changed to LHRHa. The most frequent adverse events were gynaecomastia (all grades), with 279 (38%) events in 730 patients who received LHRHa versus 690 (86%) in 807 patients who received tE2 (p<0·0001) and hot flushes (all grades) in 628 (86%) of those who received LHRHa versus 280 (35%) who received tE2 (p<0·0001). Interpretation: Long-term data comparing tE2 patches with LHRHa show no evidence of a difference between treatments in cardiovascular mortality or morbidity. Oestrogens administered transdermally should be reconsidered for androgen suppression in the management of prostate cancer. Funding: Cancer Research UK, and Medical Research Council Clinical Trials Unit at University College London

Re-examining the effect of door-to-balloon delay on STEMI outcomes in the context of unmeasured confounders: a retrospective cohort study

Literature studying the door-to-balloon time-outcome relation in coronary intervention is limited by the potential of residual biases from unobserved confounders. This study re-examines the time-outcome relation with further consideration of the unobserved factors and reports the population average effect. Adults with ST-elevation myocardial infarction admitted to one of the six registry participating hospitals in Australia were included in this study. The exposure variable was patient-level door-to-balloon time. Primary outcomes assessed included in-hospital and 30 days mortality. 4343 patients fulfilled the study criteria. 38.0% (1651) experienced a door-to-balloon delay of >90 minutes. The absolute risk differences for in-hospital and 30-day deaths between the two exposure subgroups with balanced covariates were 2.81 (95% CI 1.04, 4.58) and 3.37 (95% CI 1.49, 5.26) per 100 population. When unmeasured factors were taken into consideration, the risk difference were 20.7 (95% CI −2.6, 44.0) and 22.6 (95% CI −1.7, 47.0) per 100 population. Despite further adjustment of the observed and unobserved factors, this study suggests a directionally consistent linkage between longer door-to-balloon delay and higher risk of adverse outcomes at the population level. Greater uncertainties were observed when unmeasured factors were taken into consideration