Age-related features of the anaerobic exchange threshold (ANET) in cyclist children

Были показаны особенности реакции кардиореспираторной системы на ацидемические изменения. Спортсмены более высокой квалификации имеют более высокий ПАНО, что может служить оценкой качества и интенсивности тренировок на выносливость. The paper demonstrates the cardio-respiratory system response to acidemic changes. Athletes of higher qualifications have a higher threshold of anaerobic metabolism, which can asses the quality and intensity of endurance training.

A Personal Biography of a Physiological Misnomer: The Anaerobic Threshold

In 1973 Wasserman, Whipp, Koyal, and Beaver published a groundbreaking study titled “Anaerobic threshold and respiratory gas analysis during exercise”. At that time, respiratory gas analysis and laboratory computers had evolved such that more advanced respiratory exercise physiology studies were possible. The initial publications from this group on the onset of anaerobic metabolism in cardiac patients, the first breath-by-breath VO2 system, the first description of the anaerobic threshold, and then later new methods to detect the anaerobic threshold have been and continue to be highly cited. In fact, their 1973 anaerobic threshold paper is the sixth and their 1986 paper is the second most cited paper ever published in the Journal of Applied Physiology. The anaerobic threshold concept has also generated>5500 publications with the rates increasing over time. The publication of two papers that help to refute the “anaerobic” explanation for this phenomenon had no effect on the rates of citations of the original anaerobic threshold papers or the number of anaerobic threshold papers published since. Thus, despite now substantial evidence refuting the proposed anaerobic mechanisms underlying this phenomenon, these papers continue to be highly influential in the discipline of exercise physiology and, perhaps even more explicitly, clinical exercise physiology.

Potentiating hypoxic microenvironment for antibiotic activation by photodynamic therapy to combat bacterial biofilm infections

Traditional antibiotic treatment has limited efficacy for the drug-tolerant bacteria present in biofilms because of their unique metabolic conditions in the biofilm infection microenvironment. Modulating the biofilm infection microenvironment may influence the metabolic state of the bacteria and provide novel therapeutic routes. Here, photodynamic therapy (PDT)-activated chemotherapy by potentiating the hypoxia of biofilm infection microenvironment is proposed to tackle methicillin-resistant Staphylococcus aureus (MRSA) biofilm infections. In this study, PDT was used not only to eradicate MRSA biofilms in normoxic conditions, but also to potentiate the hypoxic microenvironment, which induces the anaerobic metabolism of MRSA and activates metronidazole to kill bacteria. Moreover, PDT-activated chemotherapy could polarize the macrophages to a M2-like phenotype and promote the repair of the biofilm infected wounds in mice. This biofilm infection microenvironment modulation strategy, whereby the hypoxic microenvironment is potentiated to synergize PDT with chemotherapy, provides an alternative pathway for efficient treatment of biofilm-associated infections.

The effect of ArcA on the growth, motility, biofilm formation, and virulence of Plesiomonas shigelloides

Background The anoxic redox control binary system plays an important role in the response to oxygen as a signal in the environment. In particular, phosphorylated ArcA, as a global transcription factor, binds to the promoter regions of its target genes to regulate the expression of aerobic and anaerobic metabolism genes. However, the function of ArcA in Plesiomonas shigelloides is unknown. Results In the present study, P. shigelloides was used as the research object. The differences in growth, motility, biofilm formation, and virulence between the WT strain and the ΔarcA isogenic deletion mutant strain were compared. The data showed that the absence of arcA not only caused growth retardation of P. shigelloides in the log phase, but also greatly reduced the glucose utilization in M9 medium before the stationary phase. The motility of the ΔarcA mutant strain was either greatly reduced when grown in swim agar, or basically lost when grown in swarm agar. The electrophoretic mobility shift assay results showed that ArcA bound to the promoter regions of the flaK, rpoN, and cheV genes, indicating that ArcA directly regulates the expression of these three motility-related genes in P. shigelloides. Meanwhile, the ability of the ΔarcA strain to infect Caco-2 cells was reduced by 40%; on the contrary, its biofilm formation was enhanced. Furthermore, the complementation of the WT arcA gene from pBAD33-arcA+ was constructed and all of the above features of the pBAD33-arcA+ complemented strain were restored to the WT level. Conclusions We showed the effect of ArcA on the growth, motility, biofilm formation, and virulence of Plesiomonas shigelloides, and demonstrated that ArcA functions as a positive regulator controls the motility of P. shigelloides by directly regulating the expression of flaK, rpoN and cheV genes.

Sport Massage Dan Waktu Recovery Asam Laktat Pada Atlit Softball

Various factors causing fatigue in athletes include an increase of lactic acid in muscles. According to the movement patterns of softball athletes, the energy source comes from the Lactaid anaerobic metabolism. Therefore, it is necessary to know the elimination of lactic acid in muscles, reflecting the decrease of lactic acid in the blood. This study aimed to determine the recovery time of lactic acid levels after exercise in 0 minutes, 5 minutes, 10 minutes, and 20 minutes. Accutrend Lactacid measured softball athlete lactic acid levels. The method used in this study was an experimental method with One-Shot Case Study research design, while the research subjects were randomly assigned from the viable softball athlete population in the Student Activity Unit. The samples included 12 athletes. Data analysis employed t-test paired scores with significance p ≤ 0.05 using SPSS V. 20.0 software. The results showed that the lactic acid levels returned to normal, namely the level of 2.79 mMol/L, at 20 minutes of rest. It concludes that that lactic acid levels of softball athletes increased after the start of training, decreased after 5 minutes of rest, and returned to normal in 20 minutes of rest.

The Role of Cerebral Oxygen Saturation Measured by Near-Infrared Spectroscopy (NIRS) in Evaluating Pediatric Shock Resuscitation Outcome

Shock in children remains public health importance and causes significant morbidity and mortality worldwide. Hypoperfusion in shock results in decreased oxygen delivery to the tissues, causing a shift from more efficient aerobic pathways to anaerobic metabolism, which results in lactate as the end product. Unlike blood lactate measurement, near-infrared spectroscopy (NIRS) monitoring system is safe and easy to use in measuring tissue oxygenation non-invasively. However, NIRS monitoring has yet to be validated against a standard measure of regional oxygenation. The primary objective of this article is to review the role of cerebral oxygen saturation (rSO2) measured by NIRS in evaluating the outcome of pediatric shock resuscitation.

Fnr Negatively Regulates Prodigiosin Synthesis in Serratia sp. ATCC 39006 During Aerobic Fermentation

The well-known Crp/Fnr family regulator Fnr has long been recognized as an oxygen sensor to regulate multiple biological processes, including the switch between aerobic/anaerobic metabolism, nitrogen fixation, bioluminescence, infection, and virulence. In most cases, Fnr was found to be active under anaerobic conditions. However, its role in aerobic antibiotic metabolism has not yet been revealed. In this research, we report that in the model organism, Serratia sp. ATCC 39006, Fnr (Ser39006_013370) negatively regulates prodigiosin production by binding to the spacer between the −10 and −35 region in the promoter of prodigiosin biosynthetic gene cluster under aerobic conditions. Fnr was also shown to modulate the anti-bacterial activity and motility by regulating pathway-specific regulatory genes, indicating that Fnr acts as a global regulator in Serratia sp. ATCC 39006. For the first time, we describe that Fnr regulates antibiotic synthesis in the presence of oxygen, which expands the known physiological functions of Fnr and benefits the further investigation of this important transcriptional regulator.