Effects of low-intensity blood flow restriction training vs. no blood flow restriction training on measures of aerobic capacity in physically active individuals

Background: Blood flow restriction (BFR) training has become an extremely popular training method over the years. Improvements in measures of aerobic capacity (such as VO2max) are crucial for individuals whom seek to be physically active for longer periods of time. Recent studies have focused on the combination of BFR and aerobic exercise at lower training intensities as an adapted training method for either maintaining or improving measures of aerobic capacity in physically active individuals.Clinical Question: In physically active individuals, is low-intensity blood flow restriction training more effective than no blood flow restriction training at improving measures of aerobic capacity?Methods: A computer-assisted literature search of PubMed, MEDLINE, SPORTDiscus, and EBSCOHost databases (from inception to November 2019) was utilized to identify studies of level 3 evidence or higher that assessed the effect of low-intensity BFR training versus no BFR training on measures of aerobic capacity in physically active individuals. The main outcomes of interest were either pre-post testing assessments of aerobic fitness (such as VO2max or VO2peak) and/or pre-post testing assessments of aerobic performance (such as time to exhaustion).Summary of Key Findings: The search strategy revealed 4 studies that met the inclusion criteria. One study reported that there were no significant improvements in measures of aerobic capacity when using low-intensity BFR training versus not using BFR training (1.96%, p < 0.05), while two studies reported that there in fact were significant improvements in measures of aerobic capacity (VO2max: 6.5%, p < 0.05 and TTE: 15.4%, p < 0.01; VO2max: +9.1± 6.2%, P < 0.001). One study reported that there were significant improvements in aerobic capacity when using low-intensity BFR training versus low-intensity training without BFR (BFR group: 5.6 ± 4.2%, P = 0.006, ES = 0.33; LOW group: 0.4 ± 4.7%, P = 0.75); however, high-intensity training without BFR showed greater improvements in aerobic capacity when compared to low-intensity training with BFR (HIT group: 9.2 ± 6.5%, P = 0.002, ES = 0.9).Clinical Bottom Line: There is moderate evidence to support the use of low-intensity BFR training to improve aerobic capacity in physically active individuals.Strength of Recommendation: Grade B evidence exists that low-intensity BFR training is more effective than no BFR training at improving measures of aerobic capacity in physically active individuals

Vancomycin minimum inhibitory concentration is not a substitute for clinical judgment: Response to healthcare-associated ventriculitis and meningitis

To the Editor—We read with interest the new clinical practice guideline for healthcare-associated ventriculitis and meningitis published in Clinical Infectious Diseases [1]. The guideline recommends consideration of alternative therapies for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) meningitis and ventriculitis for isolates with a vancomycin minimum in-hibitory concentration (MIC) ≥1μg/mL. We believe this recommendation places inappropriate emphasis on a single determinant of antimicrobial therapy that has uncertain clinical relevance and variable accuracy depending on the antimicrobial susceptibility testing (AST) method used. This may lead clinicians to use less well-evidenced strategies in cases likely to respond to vancomycin

Women\u27s Age of First Exposure to Internet Pornography Predicts Sexual Victimization

Increases in the availability and accessibility of Internet pornography have led growing numbers of children to become consumers of sexually explicit media. Research has identified negative behavioral and attitudinal outcomes associated with Internet pornography use in childhood and adolescence, but few studies have examined sexual victimization as a correlate. The current study aimed to examine the association between age of first Internet pornography exposure and sexual victimization. Data from 154 undergraduate women yielded several important findings. Women who viewed Internet pornography unintentionally at a younger age reported more sexual victimization. Specifically, compared to women who were first unintentionally exposed to Internet pornography at age 14 or older, women with unintentional first Internet pornography exposure before the age of 14 reported more childhood sexual abuse, sexual abuse in adulthood, and more instances of sexual coercion and aggression. Women with younger age of unintentional Internet pornography exposure also reported more interpersonal sexual objectification than women who had never viewed Internet pornography at all. Age of first intentional exposure to Internet pornography was not related to women’s self-reported experiences of objectification, although this may be because women’s intentional exposure tended to happen at older ages. Overall, the results of this study suggest that women’s unintentional Internet pornography exposure at a young age may contribute to a potentially harmful sexual socialization. Early Internet pornography exposure in childhood should be considered a potential risk factor for women’s sexual victimization

Utilizing Low-Intensity Blood Flow Restriction Training to Improve Aerobic Capacity in Physically Active and Injured Individuals: A Critically Appraised Topic

Purpose: To determine if, in physically active individuals, low-intensity Blood Flow Restriction (BFR) training is more effective than training without BFR at improving measures of aerobic capacity. Methods: A database search was conducted for articles that matched inclusion criteria (minimum level 2 evidence, physically active participants, comparison of low-intensity BFR to no BFR training, comparison of pre-post testing with aerobic fitness or performance, training protocols \u3e2 weeks, studies published after 2010) by two authors and assessed by one using the PEDro scale (a minimum of 5/10 was required) to ensure level 2 quality studies that were then analyzed. Results: Four studies met all inclusion criteria. Three of the studies found significant improvements in aerobic capacity (VO2max) using BFR compared to no BFR. While the fourth study reported significant improvements in time to exertion (TTE) training with BFR, this same study did not find significant improvements in measures of aerobic capacity with BFR training. All compared BFR to non-BFR training. It was noted that high-intensity training without BFR was superior to both low-intensity training with and without BFR with respect to improvements in aerobic capacity. Conclusions: Moderate evidence exists to support the use of low-intensity BFR training to improve measures of aerobic capacity in physically active individuals over not using BRF. Clinicians seeking to maintain aerobic capacity in their patients who are unable, for various reasons, to perform high levels of aerobic activity may find low-intensity BFR training useful as a substitution while still receiving improvements in measures of aerobic capacity

When do confounding by indication and inadequate risk adjustment bias critical care studies? A simulation study

Abstract Introduction In critical care observational studies, when clinicians administer different treatments to sicker patients, any treatment comparisons will be confounded by differences in severity of illness between patients. We sought to investigate the extent that observational studies assessing treatments are at risk of incorrectly concluding such treatments are ineffective or even harmful due to inadequate risk adjustment. Methods We performed Monte Carlo simulations of observational studies evaluating the effect of a hypothetical treatment on mortality in critically ill patients. We set the treatment to have either no association with mortality or to have a truly beneficial effect, but more often administered to sicker patients. We varied the strength of the treatment’s true effect, strength of confounding, study size, patient population, and accuracy of the severity of illness risk-adjustment (area under the receiver operator characteristics curve, AUROC). We measured rates in which studies made inaccurate conclusions about the treatment’s true effect due to confounding, and the measured odds ratios for mortality for such false associations. Results Simulated observational studies employing adequate risk-adjustment were generally able to measure a treatment’s true effect. As risk-adjustment worsened, rates of studies incorrectly concluding the treatment provided no benefit or harm increased, especially when sample size was large (n = 10,000). Even in scenarios of only low confounding, studies using the lower accuracy risk-adjustors (AUROC < 0.66) falsely concluded that a beneficial treatment was harmful. Measured odds ratios for mortality of 1.4 or higher were possible when the treatment’s true beneficial effect was an odds ratio for mortality of 0.6 or 0.8. Conclusions Large observational studies confounded by severity of illness have a high likelihood of obtaining incorrect results even after employing conventionally “acceptable” levels of risk-adjustment, with large effect sizes that may be construed as true associations. Reporting the AUROC of the risk-adjustment used in the analysis may facilitate an evaluation of a study’s risk for confounding.http://deepblue.lib.umich.edu/bitstream/2027.42/111639/1/13054_2015_Article_923.pd

Homozygous in-frame deletion in CATSPERE in a man producing spermatozoa with loss of CatSper function and compromised fertilizing capacity

STUDY QUESTIONDoes a man (patient 1) with a previously described deficiency in principle cation channel of sperm (CatSper) function have a mutation in the CatSper-epsilon (CATSPERE) and/or CatSper-zeta (CATSPERZ) gene?SUMMARY ANSWERPatient 1 has a homozygous in-frame 6-bp deletion in exon 18 (c.2393_2398delCTATGG, rs761237686) of CATSPERE.WHAT IS KNOWN ALREADYCatSper is the principal calcium channel of mammalian spermatozoa. Spermatozoa from patient 1 had a specific loss of CatSper function and were unable to fertilize at IVF. Loss of CatSper function could not be attributed to genetic abnormalities in coding regions of seven CatSper subunits. Two additional subunits (CatSper-epsilon (CATPSERE) and CatSper-zeta (CATSPERZ)) were recently identified, and are now proposed to contribute to the formation of the mature channel complex.STUDY DESIGN, SIZE, DURATIONThis was a basic medical research study analysing genomic data from a single patient (patient 1) for defects in CATSPERE and CATSPERZ.PARTICIPANTS/MATERIALS, SETTING, METHODSThe original exome sequencing data for patient 1 were analysed for mutations in CATSPERE and CATSPERZ. Sanger sequencing was conducted to confirm the presence of a rare variant.MAIN RESULTS AND THE ROLE OF CHANCEPatient 1 is homozygous for an in-frame 6-bp deletion in exon 18 (c.2393_2398delCTATGG, rs761237686) of CATSPERE that is predicted to be highly deleterious.LIMITATIONS, REASONS FOR CAUTIONThe nature of the molecular deficit caused by the rs761237686 variant and whether it is exclusively responsible for the loss of CatSper function remain to be elucidated.WIDER IMPLICATIONS OF THE FINDINGSPopulation genetics are available for a significant number of predicted deleterious variants of CatSper subunits. The consequence of homozygous and compound heterozygous forms on sperm fertilization potential could be significant. Selective targeting of CatSper subunit expression maybe a feasible strategy for the development of novel contraceptives.STUDY FUNDING/COMPETING INTEREST(S)This study was funded by project grants from the MRC (MR/K013343/1 and MR/012492/1), Chief Scientist Office/NHS research Scotland. This work was also supported by NIH R01GM111802, Pew Biomedical Scholars Award 00028642 and Packer Wentz Endowment Will to P.V.L. C.L.R.B is the editor-in-chief of Molecular Human Reproduction, has received lecturing fees from Merck and Ferring, and is on the Scientific Advisory Panel for Ohana BioSciences. C.L.R.B was chair of the World Health Organization Expert Synthesis Group on Diagnosis of Male infertility (2012–2016)

Initial Characterization of the FlgE Hook High Molecular Weight Complex of Borrelia burgdorferi

The spirochete periplasmic flagellum has many unique attributes. One unusual characteristic is the flagellar hook. This structure serves as a universal joint coupling rotation of the membrane-bound motor to the flagellar filament. The hook is comprised of about 120 FlgE monomers, and in most bacteria these structures readily dissociate to monomers (∼ 50 kDa) when treated with heat and detergent. However, in spirochetes the FlgE monomers form a large mass of over 250 kDa [referred to as a high molecular weight complex (HMWC)] that is stable to these and other denaturing conditions. In this communication, we examined specific aspects with respect to the formation and structure of this complex. We found that the Lyme disease spirochete Borrelia burgdorferi synthesized the HMWC throughout the in vitro growth cycle, and also in vivo when implanted in dialysis membrane chambers in rats. The HMWC was stable to formic acid, which supports the concept that the stability of the HMWC is dependent on covalent cross-linking of individual FlgE subunits. Mass spectrometry analysis of the HMWC from both wild type periplasmic flagella and polyhooks from a newly constructed ΔfliK mutant indicated that other proteins besides FlgE were not covalently joined to the complex, and that FlgE was the sole component of the complex. In addition, mass spectrometry analysis also indicated that the HMWC was composed of a polymer of the FlgE protein with both the N- and C-terminal regions remaining intact. These initial studies set the stage for a detailed characterization of the HMWC. Covalent cross-linking of FlgE with the accompanying formation of the HMWC we propose strengthens the hook structure for optimal spirochete motility

Closing the brief case: A Fatal Case of Necrotizing Fasciitis Due to Multidrug-Resistant Acinetobacter baumannii

ANSWERS TO SELF-ASSESSMENT QUESTIONS 1. What is the most common etiology of monomicrobial (type 2) necrotizing fasciitis? a. Acinetobacter baumannii b. Staphylococcus aureus c. Streptococcus pyogenes d. Vibrio vulnificus Answer: c. Although all of the organisms listed cause type 2 necrotizing fasciitis, the most common cause is still S. pyogenes, with an incidence of 0.4 per 100,000 in the United States. Due to variations in reporting practices, the exact incidences of other etiologies are not known, but they are less common than S. pyogenes

Cellulosomics, a gene-centric approach to investigating the intraspecific diversity and adaptation of Ruminococcus flavefaciens within the rumen

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