Thermoresponsive Substrates used for the Expansion of Human Mesenchymal Stem Cells and the Preservation of Immunophenotype

The facile regeneration of undifferentiated human mesenchymal stem cells (hMSCs) from thermoresponsive surfaces facilitates the collection of stem cells avoiding the use of animal derived cell detachment agents commonly used in cell culture. This communication proposes a procedure to fabricate coatings from commercially available pNIPAm which is both affordable and a significant simplification on alternative approaches used elsewhere. Solvent casting was used to produce films in the micrometer range and successful cell adhesion and proliferation was highly dependent on the thickness of the coating produced with 1 μm thick coatings supporting cells to confluence. 3T3 cell sheets and hMSCs were successfully detached from the cast coatings upon temperature reduction. Furthermore, results indicate that the hMSCs remained undifferentiated as the surface receptor profile of hMSCs was not altered when cells were detached in this manner.     

Surgeon Migration Between Developing Countries and the United States: Train, Retain, and Gain from Brain Drain

Background

The critical shortage of surgeons in many low- and middle-income countries (LMICs) prevents adequate responses to surgical needs, but the factors that affect surgeon migration have remained incompletely understood. The goal of this study was to examine the importance of personal, professional, and infrastructural factors on surgeon migration from LMICs to the United States. We hypothesized that the main drivers of surgeon migration can be addressed by providing adequate domestic surgical infrastructure, surgical training programs, and viable surgical career paths.

Methods

We conducted an internet-based nationwide survey of surgeons living in the US who originated from LMICs.

Results

66 surgeons completed the survey. The most influential factors for primary migration were related to professional reasons (p ≤ 0.001). Nonprofessional factors, such as concern for remuneration, family, and security were significantly less important for the initial migration decisions, but adopted a more substantial role in deciding whether or not to return after training in the United States. Migration to the United States was initially considered temporary (44 %), and a majority of the surveyed surgeons have returned to their source countries in some capacity (56 %), often on multiple occasions (80 %), to contribute to clinical work, research, and education.

Conclusions

This study suggests that surgically oriented medical graduates from LMICs migrate primarily for professional reasons. Initiatives to improve specialist education and surgical infrastructure in LMICs have the potential to promote retention of the surgical workforce. There may be formal ways for LMICs to gain from the international pool of relocated surgeons.     

Evidence for treatment of muscular vein thrombosis in orthopaedic patients

Background

Does below-knee symptomatic muscular (gastrocnemius or soleus) vein thrombosis (MVT) warrant investigation and treatment in post-operative orthopaedic patients? We performed a literature search and evaluated the evidence looking for guidance regarding this question.

Materials and methods

We performed a literature search with the use of PubMed, Medline and Google Scholar from 1950 to September 2011. Search terms included “muscular vein thrombosis” (MVT) and “isolated gastrocnemius or soleus vein thrombosis” (IGSVT). We reviewed the eight level II studies relevant to our search, only one of which was in a specific orthopaedic population.

Results

Studies looking at the rates of progression of isolated MVT have shown conflicting results. There is also a lack of consensus between studies that compare progression amongst groups with or without anticoagulant treatment. The majority of the studies do not distinguish between medical, surgical or orthopaedic patients.

Conclusions

We cannot confidently recommend commencement of anticoagulation treatment upon identification of MVT in post-operative orthopaedic patients. We can only suggest that, once MVT is diagnosed, the patient should undergo serial ultrasound scan (USS) duplex scans, and if propagation is identified, then treatment may be deemed beneficial.Level of evidence: III (review of non-randomized controlled cohort/follow-up studies).     

Combined Hyperlipidemia In A Single Subject With Tetraplegia: Ineffective Risk Reduction After Atorvastatin Monotherapy

Abstract

Background/Objective: Effects of atorvastatin (Lipitor) drug monotherapy (1 0 mg daily) on fasting blood Iipid profiles and cardiovascular disease (CVD) risks were examined for a single subject with C5-C6 tetraplegia. Routine fasting Iipid profiles were analyzed by standard biochemistry techniques for total cholesterol (TC) , triglycerides (TG) , low-density lipoprotein-cholesterol (LDL-C) , and high-density lipoprotein-cholesterol (HDL-C). Lipid profiles were analyzed on 3 occasions before drug therapy was initiated and 3 months after therapy commenced. The TC:HDL and LDL:HDL ratios were computed for all sampling times and used to assess pretreatment and post-treatment CVD risk.

Results: Fasting TC, TG, and LDL-C were all significantly reduced by therapy. The pretreatment HDL-C of 3 5 mg/ dl was lowered to 21 mg/ dl. As a result, the TC:HDL risk ratiowas only marginally reduced from 6 .6 to 6.4, whereas the LDL:HDL risk ratio remained unchanged by treatment.

Conclusions: In this man with tetraplegia, atorvastatin drug monotherapy rapidly lowered TC, TG, LDL-C, and HDL-C. However, the TC: HDL ratio, considered the best predictor of CVD risk, was unchanged.     

Evidence for an Exaggerated Postprandial Lipemia in Chronic Paraplegia

Abstract

Background/Objective: Excessive delay in triglyceride (TG) metabolism after ingestion of dietary fatrepresents a significant cardiovascular disease (CVD) risk. The objective of this study was to compare thepostprandial lipemic responses of individuals with paraplegia with those of healthy nondisabled individuals.

Methods: The ability of 3 recreationally active individuals with paraplegia having normal fasting TG(mean= 103 mg/dl) to metabolize TG after ingestion of a high-fat test meal was compared with apreviously published cohort of 21 recreationally active individuals without paraplegia (TG mean= 86 mg/dl)who underwent identical testing. The subjects with paraplegia had venous blood taken under fastingconditions, and then ingested a milkshake containing premium ice cream blended with heavy whippingcream(~ 92% of calories from fat). Additional blood samples were obtained at 2, 4, and 6 hours afteringestion. The area under the curve (AUC) for TG clearance for both subject groups was measured with anarea planimeter.

Results: TG uptake for both groups was almost identical for the first 2 hours after ingestion. At 4 and 6 hoursafter ingestion, the TG levels were 50 and 35 mg/dl higher, respectively, in subjects with paraplegia than innondisabled subjects. When corrected for small baseline differences in TG concentrations (16 mg/dl), theAUC was 46.5% greater for the group with paraplegia than in the nondisabled group. A near mirrorassociation across time was observed between postprandial serum high-density lipoprotein cholesterol(HDL-C) and TG levels in subjects with paraplegia.

Conclusion: This case series finds an exaggerated postprandial lipemia (PPL) in persons with paraplegiawith normal fasting TGs. This finding is the first evidence, in a small population, of an unreported potentialCVD risk in persons with paraplegia.     

ASO Visual Abstract: Time to Surgical Treatment and Facility Characteristics as Potential Drivers of Racial Disparities in Breast Cancer Mortality: Delay,Facilities, and Breast Cancer Mortality

Annals of Surgical Oncology -     

Information literacy: developing lifelong skills through nursing education

The amount and complexity of information nurses are expected to manage continues to increase exponentially. Support has grown for integrated curriculum approaches that include appropriate content on the use of a variety of information formats and instruction using resource-based and process methods. Such teaching-learning approaches demand a major shift in educational paradigms and encompass resource-based learning, undergraduate research, service learning, inquiry learning, and problem-based learning. The implementation of an integrated curriculum promises advanced information skills, access, and use of available evidence to support clinical decision making and a foundation for lifetime learning. In this article, we argue that for information literacy to be enhanced, collaboration between teaching faculty and librarians must be fostered in meaningful ways. We report on the rationale of an integrated curriculum, changes to nursing education, and obstacles to the development and application of advanced information skills that exist within higher education and clinical settings.     

Effects of Circuit Resistance Training and Timely Protein Supplementation on Exercise-Induced Fat Oxidation in Tetraplegic Adults

Background:

Substrate utilization during exercise in persons with spinal cord injury (SCI) remains poorly defined.

Purpose:

To investigate effects of circuit resistance training (CRT) and timing of protein supplementation (PS) on fuel utilization in persons with tetraplegia.

Methods:

Eleven individuals with chronic tetraplegia underwent 6 months of CRT 3 times weekly. Five randomly assigned participants received immediate PS (iPS) administered in split doses prior to and following all exercise sessions. Other participants consumed a matched dose of PS that was delayed until 24 hours post-exercise (dPS). Participants underwent a maximal graded exercise test (GXT) to volitional exhaustion at 4 conditioning time points: 3 months before (-3mo), at the beginning of (0mo), 3 months into (3mo), and 6 months following (6mo) the CRT conditioning program. Respiratory measures were continuously obtained throughout the GXT via open-circuit spirometry. Fuel utilization and energy expenditure were computed from the respiratory data.

Results:

The differences in changes in substrate utilization between the PS groups were not significant as determined by the interaction of PS group and conditioning time point, F (3, 27) = 2.32, P = .098, η²_P = .205. Maximal absolute fat oxidation did not change significantly from 0 to 6mo (mean difference, 0.014 ± 0.031 g/min; P = .170), and fat oxidation remained low never exceeding an average of 0.10 ± 0.09 g/min for any given exercise intensity.

Conclusion:

Maximum fat utilization during exercise and fat utilization at matched exercise intensities were not increased in persons with tetraplegia, independent of PS, and levels of fat oxidation remained low after training.Key words: carbohydrate, fat, oxidationCnsiderable evidence documents a disturbing prevalence of overweight and obesity in persons with spinal cord injury (SCI). Combined prevalence rates for conditions of overweight and obesity in persons with chronic SCI are daunting; depending on the definition used for classification, they range from 55%¹ to 95.7%² of the population. Accretion of body fat is most common within 2 to 7 months of injury after SCI and is likely caused by physical deconditioning, loss of metabolically active muscle mass, reduced whole body energy expenditure, and a hypercaloric diet whose macronutrient composition is excessive in saturated fat.Fat oxidation plays an important role in daily energy homeostasis and the etiology of obesity, and numerous studies have reported a reduced ability to oxidize fat in obese individuals at rest and during exercise.^3–8 It is known that persons with physical disability have a 1.2- to 3.9-fold higher prevalence of obesity than those without disability,⁹ yet little is known about their substrate partitioning at rest or during physical activity. When compared to nondisabled controls performing voluntary exercise, persons with SCI have markedly reduced mobilization, delivery, and limb uptake of free fatty acids (FFA) during electrically stimulated leg exercise.¹⁰ This is most likely the result of reduced sympathoadrenal ß-adrenergic stimulation and/or limited neural activity in motor centers and afferent nerves from working muscle, depending on the level of injury.¹⁰ The limited FFA availability during exercise leads to heavy reliance on carbohydrates (CHO) and the limited contribution of fats as a fuel source.^11–15Knowledge of training-induced adaptations in substrate use after SCI represents an important step in evaluating exercise as a legitimate intervention to reduce the prevalence and severity of cardioendocrine diseases such as obesity; these adaptations have received limited research attention. A majority of studies on substrate partitioning after SCI have involved subjects who were already well-trained.^11–15 Otherwise, functional electrical stimulation (FES) training for 1 year shifted muscle fiber type distribution toward fatigue resistance and increased the activity of mitochondrial enzymes citrate synthase and ß-hydroxyacyl-CoA-dehydrogenase.^16,17 Although these adaptations provide indirect evidence for higher rates of maximal whole body fat oxidation, their effects on substrate oxidation and partitioning during more common volitional arm exercise were not examined.We have previously reported that 6 months of circuit resistance training (CRT) performed by persons with chronic SCI improves fitness measures of peak cardiorespiratory (CR) capacity (VO_2peak), time to fatigue, peak and average anaerobic power output, and isokinetic and isoinertial strength.^18,19 Recent data from our laboratory²⁰ also show that the addition of an optimally timed protein supplementation (PS) to a CRT conditioning program by persons with chronic tetraplegia augments gains made in CR fitness and anaerobic power, although it is not known whether these fitness gains translate into increased fat oxidation during exercise. As improvements in CR fitness have long been associated with an enhanced ability to utilize fat as a fuel source,^21–23 this investigation analyzed changes on substrate utilization following 6 months of CRT in persons with tetraplegia and examined whether these changes were affected by timely PS. It was hypothesized that conditioning exercise would be associated with greater amounts and proportions of fat utilization measured during matched intensities of subpeak work and that timely PS would further enhance these beneficial conditioning adaptations.