Postcontraction [acetylcarnitine] reflects interindividual variation in skeletal muscle ATP production patterns in vivo

In addition to its role in substrate selection (carbohydrate vs. fat) for oxidative metabolism in muscle, acetylcarnitine production may be an important modulator of the energetic pathway by which ATP is produced. A combination of noninvasive magnetic resonance spectroscopy measures of cytosolic acetylcarnitine and ATP production pathways was used to investigate the link between [acetylcarnitine] and energy production in vivo. Intracellular metabolites were measured in the vastus lateralis muscle of eight males (mean: 28.4 yr, range: 25-35) during 8 min of incremental, dynamic contractions (0.5 Hz, 2-min stages at 6%, 9%, 12%, and 15% maximal torque) that increased [acetylcarnitine] approximately fivefold from resting levels. ATP production via oxidative phosphorylation, glycolysis, and the creatine kinase reaction was calculated based on phosphorus metabolites and pH. Spearman rank correlations indicated that postcontraction [acetylcarnitine] was positively associated with both absolute (mM) and relative (% total ATP) glycolytic ATP production (rs = 0.95, P = 0.001; rs = 0.93, P = 0.002), and negatively associated with relative (rs = -0.81, P = 0.02) but not absolute (rs = -0.14, P = 0.75) oxidative ATP production. Thus, acetylcarnitine accumulated more when there was a greater reliance on "nonoxidative" glycolysis and a relatively lower contribution from oxidative phosphorylation, reflecting the fate of pyruvate in working skeletal muscle. Furthermore, these data indicate striking interindividual variation in responses to the energy demand of submaximal contractions. Overall, the results of this preliminary study provide novel evidence of the coupling in vivo between ATP production pathways and the carnitine system.NEW & NOTEWORTHY Production of acetylcarnitine from acetyl-CoA and free carnitine may be important for energy pathway regulation in contracting skeletal muscle. Noninvasive magnetic resonance spectroscopy was used to investigate the link between acetylcarnitine and energy production in the vastus lateralis muscle during dynamic contractions (n = 8 individuals). A positive correlation between acetylcarnitine accumulation and "nonoxidative" glycolysis and an inverse relationship with oxidative phosphorylation, provides novel evidence of the coupling between ATP production and the carnitine system in vivo.

771 LET’S TALK ABOUT RESUS. DO WE DO IT? WHO DOES IT? WHAT ARE THE OUTCOMES?

Introduction

Discussing preferences around cardiopulmonary resuscitation (CPR) is recommended to patients who wish to discuss this, or where there is foreseeable risk of life-threatening clinical deterioration. Our team felt that we discussed this routinely for our inpatients but wished to investigate how we did this, when we did this, why decisions were made and who led these discussions.

Methods

We retrospectively reviewed the electronic patient notes of 118 patients recently discharged from elderly medicine between February and November 2020 and recorded demographic details, co-morbidities and outcomes of discussions regarding resuscitation.

Results

100/118 patients had a RESPECT form documenting preferences. Of these 100 patients, 97% had a DNACPR recommendation, 2 had a ‘for resuscitation’ recommendation and one was undecided. 69% of patients had their preferences recorded during the current admission. 43% of discussions were led by a tier 1/2 doctor. 21% of discussions were led by a tier 3 doctor. 23% of discussions were led by a consultant. It was unclear who had led the discussion 13% of the time. 29/97 patients had a DNACPR due to their wishes. 16/97 patients had a DNACPR based on clinical grounds that it would not succeed. 33/97 patients had a DNACPR on the grounds that burden outweighed risks and they had capacity In 19/97 patients the reason for DNACPR was not clearly documented. There were 6 discussions where there was distress or disagreement—all of the discussions resulted in DNACPR recommendation 1 patient had a DNACPR reversed during their admission and none were reversed afterwards.

Conclusion

Systematically discussing preferences around resuscitation is feasible and rarely results in distress. The majority of patients have a recommendation for DNACPR and discussions are led by ‘junior’ doctors.

Emotional labor and professional practice in sports medicine and science

The aim of this study was to explore how sport medicine and science practitioners manage their emotions through emotional labor when engaging in professional practice in elite sport. To address the research aim a semistructured interview design was adopted. Specifically, eighteen professional sport medicine and science staff provided interviews. The sample comprised sport and exercise psychologists (n=6), strength and conditioning coaches (n=5), physiotherapists (n=5), one sports doctor and one generic sport scientist. Following a process of thematic analysis, the results were organized into the following overarching themes: (a) factors influencing emotional labor enactment, (b) emotional labor enactment, and (c) professional and personal outcomes. The findings provide a novel contribution to understanding the professional demands faced by practitioners and are discussed in relation to the development of professional competencies and the welfare and performance of sport medics and scientists.

A single-center evaluation of the risk for colonization or bacteremia with piperacillin-tazobactam- and cefepime-resistant bacteria in patients with acute leukemia receiving fluoroquinolone prophylaxis

Fluoroquinolone prophylaxis is indicated to prevent neutropenic fever in patients with acute leukemia. However, fluoroquinolone use has been associated with development of multi-drug-resistant Pseudomonas aeruginosa and extended spectrum β-lactamase producing gram-negative bacilli. Due to a presumed risk of multi-drug resistance associated with fluoroquinolone prophylaxis, patients admitted to our hospital with neutropenic fever receive empiric carbapenem therapy until cultures are negative for 72 h or identification of an organism. Our study seeks to identify the incidence of multi-drug-resistant organism colonization and bacteremia among patients who receive fluoroquinolone prophylaxis and to evaluate duration of empiric carbapenem therapy. A retrospective review of adult patients with acute leukemia receiving a fluoroquinolone as outpatient infection prophylaxis, admitted to our tertiary cancer center for treatment of neutropenic fever was completed. Surveillance and blood cultures were reviewed for antibiotic resistance. Duration of empiric carbapenem therapy was reviewed. One hundred patients and 177 admissions for neutropenic fever were included. Six patients harbored a piperacillin-tazobactam-resistant organism found during routine surveillance. Among these patients, two bacteremias were identified, one of which was a piperacillin-tazobactam-resistant organism. Five bacteremias were identified among 83 patients with negative surveillance cultures. Among the bloodstream infections, five organisms isolated were fluoroquinolone resistant. No cefepime-resistant organism was isolated on surveillance or bloodstream cultures. Adherence to the institution guideline of narrowing antibiotics after 72 h of negative cultures occurred in only 13% of neutropenic fever cases. The average duration of carbapenem therapy in 177 neutropenic fever episodes was 4.4 days. Our findings show that among our patient population, there is a low risk of bacteremia with a piperacillin-tazobactam-resistant or cefepime-resistant organism. However, prompt de-escalation of carbapenem therapy needs to be reiterated within hospital practice.

The Input Signal Step Function (ISSF), a standard method to encode input signals in SBML models with software support, applied to circadian clock models

Time-dependent light input is an important feature of computational models of the circadian clock. However, publicly available models encoded in standard representations such as the Systems Biology Markup Language (SBML) either do not encode this input or use different mechanisms to do so, which hinders reproducibility of published results as well as model reuse. The authors describe here a numerically continuous function suitable for use in SBML for models of circadian rhythms forced by periodic light-dark cycles. The Input Signal Step Function (ISSF) is broadly applicable to encoding experimental manipulations, such as drug treatments, temperature changes, or inducible transgene expression, which may be transient, periodic, or mixed. It is highly configurable and is able to reproduce a wide range of waveforms. The authors have implemented this function in SBML and demonstrated its ability to modify the behavior of publicly available models to accurately reproduce published results. The implementation of ISSF allows standard simulation software to reproduce specialized circadian protocols, such as the phase-response curve. To facilitate the reuse of this function in public models, the authors have developed software to configure its behavior without any specialist knowledge of SBML. A community-standard approach to represent the inputs that entrain circadian clock models could particularly facilitate research in chronobiology.

What is the biological basis of pattern formation of skin lesions?

Pattern recognition is at the heart of clinical dermatology and dermatopathology. Yet, while every practitioner of the art of dermatological diagnosis recognizes the supreme value of diagnostic cues provided by defined patterns of 'efflorescences', few contemplate on the biological basis of pattern formation in and of skin lesions. Vice versa, developmental and theoretical biologists, who would be best prepared to study skin lesion patterns, are lamentably slow to discover this field as a uniquely instructive testing ground for probing theoretical concepts on pattern generation in the human system. As a result, we have at best scraped the surface of understanding the biological basis of pattern formation of skin lesions, and widely open questions dominate over definitive answer. As a symmetry-breaking force, pattern formation represents one of the most fundamental principles that nature enlists for system organization. Thus, the peculiar and often characteristic arrangements that skin lesions display provide a unique opportunity to reflect upon--and to experimentally dissect--the powerful organizing principles at the crossroads of developmental, skin and theoretical biology, genetics, and clinical dermatology that underlie these--increasingly less enigmatic--phenomena. The current 'Controversies' feature offers a range of different perspectives on how pattern formation of skin lesions can be approached. With this, we hope to encourage more systematic interdisciplinary research efforts geared at unraveling the many unsolved, yet utterly fascinating mysteries of dermatological pattern formation. In short: never a dull pattern!

An outbreak of multi-resistant Shigella sonnei in a long-stay geriatric nursing centre

An outbreak of Shigella sonnei infection in a long-stay nursing centre was detected during routine surveillance of notifications in July 1999. Subsequent investigations identified 13 cases of multi-resistant S. sonnei infection affecting nine staff, three community members associated with the centre and one resident of the centre. Each isolate of S. sonnei was genetically indistinguishable. The outbreak investigation identified contact with residents with vomiting and diarrhoea as a significant risk factor for infection amongst staff providing nursing care. This association, and the duration of the outbreak over several months, suggests that transmission was most likely person-to-person. This outbreak demonstrates the importance of infection control policies and hygiene measures in long-stay nursing facilities.

Cross-species amplification of soybean (Glycine max) simple sequence repeats (SSRs) within the genus and other legume genera: implications for the transferability of SSRs in plants

We investigated the transferability of 31 soybean (Glycine max) simple sequence repeat (SSR) loci to wild congeners and to other legume genera. Up to 65% of the soybean primer pairs amplified SSRs within Glycine, but frequently, the SSRs were short and interrupted compared with those of soybeans. Nevertheless, 85% of the loci were polymorphic within G. clandestina. Cross-species amplification outside of the genus was much lower (3%-13%), with polymorphism restricted to one primer pair, AG81. AG81 amplified loci in Glycine, Kennedia, and Vigna (Phaseoleae), Vicia (Vicieae), Trifolium (Trifolieae), and Lupinus (Genisteae) within the Papilionoideae, and in Albizia within the Mimosoideae. The primer conservation at AG81 may be explained by its apparent proximity to the seryl-tRNA synthetase gene. Interspecific differences in allele size at AG81 loci reflected repeat length variation within the SSR region and indels in the flanking region. Alleles of identical size with different underlying sequences (size homoplasy) were observed. Our findings and the emerging patterns in other plant studies suggest that in contrast to animals, successful cross-species amplification of SSRs in plants is largely restricted to congeners or closely related genera. Because mutations in both the SSR region and the flanking region contribute to variation in allele size among species, knowledge of DNA sequence is essential before SSR loci can be meaningfully used to address applied and evolutionary questions.

Hospitalization and mortality of diabetes in older adults. A 3-year prospective study

OBJECTIVE

In light of increased fatality from acute events and the increased frequency of chronic complications, life expectancy might well be shortened in older patients with diabetes. The current studies investigated factors affecting the likelihood of dying or being hospitalized in older patients with diabetes.

RESEARCH DESIGN AND METHODS

A total of 135 older patients with diabetes were followed for 3 years after predictive factors were evaluated and compared with a cohort of patients without diabetes.

RESULTS

Mortality was only 3,250 per 100,000 patient-years, similar to that for patients without diabetes, but the frequency of hospitalizations was more than twice as high in patients with diabetes. Five factors predicted hospitalization and death. Of these, the geriatric depression score was the best predictor of these poor outcomes.

CONCLUSIONS

Older patients with diabetes were hospitalized more often than those without diabetes, but mortality was similar. Dysphoria is a major predictor of poor outcomes in older patients with diabetes.

Effects of sexual intercourse on maximal aerobic power, oxygen pulse, and double product in male sedentary subjects

It is well known that athletes in the United States are told to abstain from sexual intercourse prior to athletic competition. The rationale for such a policy appears to be related to the hypothesis that sexual intercourse decreases the athletes' ability to perform efficiently and/or maximally. But the effect that sexual intercourse may have on exercise performance has not been examined widely. Very likely, the restrictions placed on athletes have little to do with the athletes' physiological ability to substain a particular exercise intensity and/or perform maximally. The purpose of this study was to determine the effects of sexual intercourse 12 hours prior to maximal treadmill exercise on aerobic power, oxygen pulse, and double product (i.e., an index of relative cardiac work). Eleven male subjects were tested on the treadmill with and without prior sexual intercourse. The results from the maximal exercise tests showed that aerobic power, oxygen pulse, and double product were not different. Therefore, the data suggest that it is justified to dismiss the point of view that sexual intercourse decreases maximal exercise performance.

The cardiovascular effects of high-dose butorphanol-nitrous oxide anaesthesia before and during operation

The cardiovascular effects of high doses of butorphanol (0.3-0.45 mg . kg-1) plus 60 per cent N2O anaesthesia were measured at unconsciousness, following tracheal intubation, and immediately before and at one and ten minutes after surgical stimulation in 17 A.S.A. class I and II patients undergoing elective gastric or gall bladder surgery. Butorphanol and N2O produced unconsciousness with only small decreases in heart rate and cardiac output but did not result in sufficient analgesia to block or treat stimulation of the cardiovascular system secondary to tracheal intubation or surgical incision, even when supplemented with additional butorphanol to high cumulative dose levels (1.0 mg . kg-1). The data suggest that even high dose butorphanol - N2O anaesthesia requires supplementation with other anaesthetics or anaesthetic adjuvants to prevent cardiovascular stimulation during general abdominal surgery.