Circulatory efficiency in patients with severe aortic valve stenosis before and after aortic valve replacement.

BACKGROUND: Circulatory efficiency reflects the ratio between total left ventricular work and the work required for maintaining cardiovascular circulation. The effect of severe aortic valve stenosis (AS) and aortic valve replacement (AVR) on left ventricular/circulatory mechanical power and efficiency is not yet fully understood. We aimed to quantify left ventricular (LV) efficiency in patients with severe AS before and after surgical AVR. METHODS: Circulatory efficiency was computed from cardiovascular magnetic resonance (CMR) imaging derived volumetric data, echocardiographic and clinical data in patients with severe AS (n = 41) before and 4 months after AVR and in age and sex-matched healthy subjects (n = 10). RESULTS: In patients with AS circulatory efficiency was significantly decreased compared to healthy subjects (9 ± 3% vs 12 ± 2%; p = 0.004). There were significant negative correlations between circulatory efficiency and LV myocardial mass (r = - 0.591, p < 0.001), myocardial fibrosis volume (r = - 0.427, p = 0.015), end systolic volume (r = - 0.609, p < 0.001) and NT-proBNP (r = - 0.444, p = 0.009) and significant positive correlation between circulatory efficiency and LV ejection fraction (r = 0.704, p < 0.001). After AVR, circulatory efficiency increased significantly in the total cohort (9 ± 3 vs 13 ± 5%; p < 0.001). However, in 10/41 (24%) patients, circulatory efficiency remained below 10% after AVR and, thus, did not restore to normal values. These patients also showed less reduction in myocardial fibrosis volume compared to patients with restored circulatory efficiency after AVR. CONCLUSION: In our cohort, circulatory efficiency is reduced in patients with severe AS. In 76% of cases, AVR leads to normalization of circulatory efficiency. However, in 24% of patients, circulatory efficiency remained below normal values even after successful AVR. In these patients also less regression of myocardial fibrosis volume was seen. Trial Registration clinicaltrials.gov NCT03172338, June 1, 2017, retrospectively registered.

Spike-triggered average electrical stimuli as input filters for bionic vision-a perspective.

Bionic retinal implants are gaining acceptance in the treatment of blindness from degenerative diseases including retinitis pigmentosa and macular degeneration. OBJECTIVE: A current obstacle to the improved performance of such implants is the difficulty of comparing the results of disparate experiments. Another obstacle is the current difficulty in selectively activating the many different retinal ganglion cell types that are used as separate pathways for visual information to the brain. APPROACH: To address these obstacles, we propose a modelling framework based on white noise stimulation and reverse correlation. In this perspective, we first outline early developments in visual retinal physiology leading up to the implementation of white noise stimuli and spike-triggered averaging. We then review recent efforts to adapt the white noise method for electrical stimulation of the retina and some of the nuances of this approach. MAIN RESULTS: Based on such white noise methods, we describe a modelling framework whereby the effect of any arbitrary electrical stimulus on a ganglion cell's neural code can be better understood. SIGNIFICANCE: This framework should additionally disentangle the effects of stimulation on photoreceptor, bipolar cell and retinal ganglion cell-ultimately supporting selective stimulation of specific ganglion cell types for a more nuanced bionic retinal implant. Finally, we point to upcoming considerations in this rapidly developing domain of research.

Replacing corn with pearl millet (raw and sprouted) with and without enzyme in chickens' diet.

An experiment was conducted to compare a commercial corn-soya bean meal diet with a pearl millet (raw and sprouted) diet containing less soya bean meal, alone or in combination with exogenous enzyme, on growth performance and ileal villus development of chicks. Two-hundred-and-forty-one-day-old male broilers (10/pen) were randomly allocated to one of the following dietary treatments: (i) a standard corn-soya bean meal control diet (CTL); (ii) a raw pearl millet-soya bean meal diet (PM); (iii) a sprouted pearl millet-soya bean meal diet (SPM); (iv) CTL + exogenous enzymes (CE); (v) PM + exogenous enzymes (PE); and (vi) SPM + exogenous enzymes (SPE) with four replicate pens/treatment. Body weight of birds at day 21 did not differ between those fed the CTL, and SPM and PE diets. In comparison with feeding broilers the CTL diet, feeding the PE and SPM diets caused significant decrease in feed intake, but with equivalent growth and feed efficiency. However, at day 21, feed conversion ratio did not differ between birds fed the CTL diet and those fed the PM, PE and SPM diets. At day 21, broilers fed the PM and PE diets had longer villi (p < 0.05) than those fed the CTL diet. At day 21, villi width was reduced (p < 0.05) by raw pearl millet supplementation than CTL diet. It is concluded that, in comparison with corn, broiler diets formulated with sprouted pearl millet or pearl millet with enzyme require less soya bean meal and can be used to improve growth performance traits and villus development.

Comparison of anger management, anxiety and perceived stress in patients with cancer and Coronary Heart Disease (CHD).

The present study was conducted with the aim of studying the comparison of anger management, anxiety and perceived stress in patients with cancer and Coronary Heart Disease (CHD). The two groups of subjects consisted of patients with cancer (n = 120) and patients with CHD (n = 118) who were selected by using a convenience sampling method and by the employment of Spielberger's State-Trait Anger Expression, Costello and Camry Depression and Anxiety scale and Perceived Stress Scale of Cohen, Kamarak and Mermelstein. In order to analyze the data, after the calculation of descriptive statistics and correlation coefficients, MONOVA was employed to test the hypotheses. The findings indicated that patients with CHD regulate the excitement by externalizing anger and patients with cancer control this excitement by internalizing anger. Moreover, stress and depression in patients with CHD were greater than in patients with cancer. The findings were explained by the employment of the theoretical patterns of the mediating role of personality and regulation of excitement in stress and illness.

Designing a minimum data set for breast cancer: a starting point for breast cancer registration in iran.

BACKGROUND: Due to the high incidence of deaths from breast cancer, high cost of treatment and limited resources, the need to formulate and implement effective programs in reducing the burden of disease is obvious. Care, control and creation of cancer information system having an infrastructure from collection of minimum data sets (MDS) are the top priorities of research in Iran's Ministry of Health. METHODS: This is an applied descriptive research with comparative approach implemented in 2010. MDS for breast cancer on selected countries were searched and reviewed and proposed model based on the country's need was designed. Research data were implemented in 2 stages; assessment of MDS on selected countries and the validation of the proposed model through several meetings that has been carried out by the Undersecretary for Research and Technology and several oncologists and pathologists. RESULTS: The MDS is composed of 11 parameters in the form of fields in closed structured arrangements with consideration to coding responses. These parameters include: hospital data, demography, referral, physical examination and investigation, diagnostic information, pathology, treatment, palliative care, completion of primary treatment, clinical trials and follow-up. This form is available for use in the cancer registry database. CONCLUSION: MDS provides an opportunity to strengthen communication between performed researches and research results for the improvement of programs, policies and strategies and provides positive effect on equality in the health system. Although the stages of creating the MDS for breast cancer has been successful, but many challenges has been met until its completion.

Evaluation of periodicals journals and community of medical sciences in iran.

BACKGROUND: Medical journals are scientific resources where utilization of knowledge is availed and create an environment of competitiveness. To speed up the growth and increase scientific production and in order that the rank of Iranian journals be defined regionally and globally, journal standardization is necessary. This study was done to evaluate the country's medical journals from 2004-2006. METHODS: This is a descriptive/analytical study. Evaluation was based on the following; scientific credibility, registry and year of service, journal management, technical quality and accessibility. The number of journals evaluated during 2004-2006 were 86, 103 and 93, respectively and the process involved 3 phases 1) defining the journal's structural indicators and designing the evaluation form 2) collection, sharing and final confirmation of information with the publication staff 3) data entry, analysis and ranking RESULTS: Improvement and growth of publication depends largely on 5 parameters and its development were based on the following; publication management (61.62 points), scientific credibility (43.80 points), quality of accessing the journals (37.05 points), quality of publication (14.80 points) and registry and year of service (0.02 points). Based on the study, an upward developmental trend of the country's medical journals can be seen and the tools were sufficient in terms of validity and reliability. A revised and more comprehensive checklist that would evaluate all aspects of a publication basing on latest indicators is developed. CONCLUSION: Evaluations of the country's medical journals not only promote compliance to international standards but also led to more indexing of journals in accredited international indices.