Physiological adaptations to exercise in people with spinal cord injury

The number of patients that suffer some type of spinal cord lesion in recent years are high and have increased because of factors such as traffic accidents. Although their life expectancy has increased, cardiovascular illnesses is one of the main causes of morbidity and mortality. Since the degree of physical fitness is an important factor regarding the risk of cardiovascular disease, the objective of the present study was to examine the global adaptation (cardiorespiratory, metabolic and thermoregulatory response) of the organism to exercise and the application of this data to the habitual practice of physical activity to improve state of health. A group of 42 patients with spinal injury, 85% of whom were paraplegic and the remaining 15% tetraplegic performed 42 exercise tests on a cycloergometer. Body temperature (tympanum, surface of the deltoids and surface of the back), metabolic parameters (plasma uric acid, glycemia, plasma lactate), cardiocirculatory adaptation (heart rate, blood pressure arm, blood pressure leg) and ventilatory adaptation (VO2, VCO2, fr Vt, VE) were monitored. Blood pressure in the arm, blood concentrations of lactate and ventilatory parameters showed an evolution statistically dependent on the work to which the subject was submitted. Heart rate showed a statistically significant correlation with the ventilatory parameters and work load. The proportional response of the cardioventilatory parameters to the increase in the work load allowed us to evaluate the repercussion of a given exercise and thus avoid exercise of an excessive intensity that could produce cardiocirculatory changes that might entail an added risk. Heart rate presents an excellent correlation, shown in this work, with the oxygen consumption and could therefore be used to quantify the cardiorespiratory and metabolic repercussion of the exercise carried out. Furthermore, this quantification may allow for the adaptation of exercise intensity to the patient thus improving the results obtained from the practice of exercise that has been proven so necessary in these patients.     

A finite-element model for healing of cutaneous wounds combining contraction, angiogenesis and closure

A simplified finite-element model for wound healing is proposed. The model takes into account the sequential steps of dermal regeneration, wound contraction, angiogenesis and wound closure. An innovation in the present study is the combination of the aforementioned partially overlapping processes, which can be used to deliver novel insights into the process of wound healing, such as geometry related influences, as well as the influence of coupling between the various existing subprocesses on the actual healing behavior. The model confirms the clinical observation that epidermal closure proceeds by a crawling and climbing mechanism at the early stages, and by a stratification process in layers parallel to the skin surface at the later stages. The local epidermal oxygen content may play an important role here. The model can also be used to investigate the influence of local injection of hormones that stimulate partial processes occurring during wound healing. These insights can be used to improve wound healing treatments.     

Long-Range Enhancer Interactions Are Prevalent in Mouse Embryonic Stem Cells and Are Reorganized upon Pluripotent State Transition

1. Download high-res image (195KB)
2. Download full-size image

     

The Influence of Body Mass Index on Outcomes in Patients Undergoing Cardiac Surgery: Does the Obesity Paradox Really Exist?

Purpose

Obesity influences risk stratification in cardiac surgery in everyday practice. However, some studies have reported better outcomes in patients with a high body mass index (BMI): this is known as the obesity paradox. The aim of this study was to quantify the effect of diverse degrees of high BMI on clinical outcomes after cardiac surgery, and to assess the existence of an obesity paradox in our patients.

Methods

A total of 2,499 consecutive patients requiring all types of cardiac surgery with cardiopulmonary bypass between January 2004 and February 2009 were prospectively studied at our institution. Patients were divided into four groups based on BMI: normal weight (18.5–24.9 kg∙m⁻²; n = 523; 21.4%), overweight (25–29.9kg∙m⁻²; n = 1150; 47%), obese (≥30–≤34.9kg∙m⁻²; n = 624; 25.5%) and morbidly obese (≥35kg∙m⁻²; n = 152; 6.2%). Follow-up was performed in 2,379 patients during the first year.

Results

After adjusting for confounding factors, patients with higher BMI presented worse oxygenation and better nutritional status, reflected by lower PaO₂/FiO₂ at 24h and higher albumin levels 48h after admission respectively. Obese patients showed a higher risk for Perioperative Myocardial Infarction (OR: 1.768; 95% CI: 1.035–3.022; p = 0.037) and septicaemia (OR: 1.489; 95% CI: 1.282–1.997; p = 0.005). In-hospital mortality was 4.8% (n = 118) and 1-year mortality was 10.1% (n = 252). No differences were found regarding in-hospital mortality between BMI groups. The overweight group showed better 1-year survival than normal weight patients (91.2% vs. 87.6%; Log Rank: p = 0.029. HR: 1.496; 95% CI: 1.062–2.108; p = 0.021).

Conclusions

In our population, obesity increases Perioperative Myocardial Infarction and septicaemia after cardiac surgery, but does not influence in-hospital mortality. Although we found better 1-year survival in overweight patients, our results do not support any protective effect of obesity in patients undergoing cardiac surgery.     

La calidad de vida en ancianos polimedicados con multimorbilidad

Objectives

To estimate the values of the quality of life dimensions using the SF-12 questionnaire in the elderly on polymedication and with multiple morbidities, and identify the variables associated with it.

Material and methods

A cross-sectional study on a sample of 393 patients selected from the elderly population over 67 years and who took more than 5 drugs. The SF-12 was complemented by a personal interview in the clinic or in the home of the patient. Central tendency, dispersion, and the percentiles of the 8 dimensions were calculated, as well as the SF-36 physical and mental component summary measures (PCS and MCS). All patients below the 25th percentile of the PCS and MCS were classified as patients with a deterioration. Logistic regression was used to determine the variables that were associated with the deterioration in the quality of life.

Results

It is a population with high morbidity. The subjects showed very low scores on the general health scales −mean (SD): 25.7 (17.4)−; physical function −32.6 (32.1)−; and PCS: [(37.8 (25.1)]. Women had a worse quality of life than men in all the scales. Female sex, being over 80 years, frequent falls, chronic pain, cancerous disease, and depression, are variables that determine the health-related quality of life (HR-QoL).

Conclusion

This population has a poor HR-QoL, particularly in the physical dimensions. Chronic pain and depression, together with age and being female are variables that determine the deterioration in the HR-QoL.     

Racemization and transesterification of alkyl hydrogeno-phenylphosphinates

In this article, we explore, both theoretically and experimentally, the general reactivity of alkyl hydrogeno-phenylphosphinates with alcohols. We show that alcohol molecules act exclusively as nucleophilic species, and add to alkyl hydrogeno-phenylphosphinates, leading to pentacoordinated intermediates. These intermediates are shown to subsequently competitively undergo alcohol eliminations and/or Berry pseudorotations. This offers several possible routes for racemizations and/or alcohol exchange reactions. Transition standard Gibbs free energies predicted from DFT calculations for the overall alcohol exchange mechanism are shown to be compatible with those experimentally measured in case ethanol reacts with ethyl hydrogeno-phenylphosphinate (134.5～136.0 kJ mol^?1 at 78 °C).

Open image in new window

Graphical abstract ?

     

Creatine supplementation and performance in 6 consecutive 60 meter sprints

Creatine is an ergogenic aid used in individual and team sports. The aim of this study is to analyze the effect of monohydrate creatine supplementation on physical performance during 6 consecutive maximal speed 60 meter races, and the changes induced in some characteristic biochemical and ventilatory parameters. The study was carried out on nineteen healthy and physically active male volunteers, and randomly distributed into two groups: Group C received a supplement of creatine monohydrate (20 g/day for 5 days) and group P received placebo. Tests were performed before and after supplementation. No significant changes were observed in weight or body water measured by bioimpedance or the sum of 7 skinfold or performance during the 60 meter races. Group C showed a statistically significant increase in plasma creatinine from 69.8 +/- 12.4 to 89.3 +/- 12.4 micromol x L(-1) (p<0.05). In group C in the second control day (after creatine supplementation), expiratory volume V(E), O2 uptake and CO2 production were lower after 2 minutes of active recovery period. These results indicate that creatine monohydrate supplementation does not appear to improve the performance in 6 consecutive 60 meter repeated races but may modify ventilatory dynamics during the recovery after maximal effort.     

Comparison of Hi-C results using in-solution versus in-nucleus ligation

BackgroundChromosome conformation capture and various derivative methods such as 4C, 5C and Hi-C have emerged as standard tools to analyze the three-dimensional organization of the genome in the nucleus. These methods employ ligation of diluted cross-linked chromatin complexes, intended to favor proximity-dependent, intra-complex ligation. During development of single-cell Hi-C, we devised an alternative Hi-C protocol with ligation in preserved nuclei rather than in solution. Here we directly compare Hi-C methods employing in-nucleus ligation with the standard in-solution ligation.ResultsWe show in-nucleus ligation results in consistently lower levels of inter-chromosomal contacts. Through chromatin mixing experiments we show that a significantly large fraction of inter-chromosomal contacts are the result of spurious ligation events formed during in-solution ligation. In-nucleus ligation significantly reduces this source of experimental noise, and results in improved reproducibility between replicates. We also find that in-nucleus ligation eliminates restriction fragment length bias found with in-solution ligation. These improvements result in greater reproducibility of long-range intra-chromosomal and inter-chromosomal contacts, as well as enhanced detection of structural features such as topologically associated domain boundaries.ConclusionsWe conclude that in-nucleus ligation captures chromatin interactions more consistently over a wider range of distances, and significantly reduces both experimental noise and bias. In-nucleus ligation creates higher quality Hi-C libraries while simplifying the experimental procedure. We suggest that the entire range of 3C applications are likely to show similar benefits from in-nucleus ligation.

Electronic supplementary material

The online version of this article (doi:10.1186/s13059-015-0753-7) contains supplementary material, which is available to authorized users.