Oxygen Consumption Index Research Articles

Development of myocardial oxygen consumption index using non-invasive continuous blood pressure monitor and practical application of optimal exercise prescription algorithm

Cardiology is a crucial speciality given the prevalence of cardiovascular disease. As weight gain and a sedentary lifestyle are major factors associated with heart disease, many prevention efforts and treatment strategies centre on exercise. Associate Professor (Lecturer) Yasunori Suematsu is a cardiologist based at Fukuoka University Hospital who is working to optimise exercise therapy for patients in the rehabilitation phase of treatment. Suematsu is developing a myocardial oxygen consumption index using a non-invasive continuous blood pressure monitor and working on an optimal exercise prescription algorithm to assist in the post-recovery treatment of his patients. As optimal exercise intensity varies depending on the day and factors such as physical condition, pathological condition, mental state, recovery and autonomic nerve activity, the programme that Suematsu is developing enables individuals to easily measure their optimal exercise intensity for the day. This means that they can exercise at the most beneficial intensity for them every day. When it comes to data collection for the programme, he is interested in the product of systolic blood pressure and heart rate, called the double product, which enables him to evaluate the anaerobic metabolic threshold. His new technique enables this to be measured accurately and non-invasively using a device called a continuous sphygmomanometer, which can continuously measure blood pressure. The researchers are using this to develop a new myocardial oxygen consumption marker using the double product as a reference.

The Role of Metabolic Therapy in the Treatment of Chronic Coronary Syndrome. Results of Own Research

Ischemic heart disease (IHD) and stroke are the main causes of mortality and disability worldwide. One of the most controversial issues in modern cardiology is the feasibility of using metabolic drugs for the treatment of patients with angina. The main directions in metabolic therapy are optimization of energy production and expenditure and normalization of the balance between the intensity of free radical oxidation and antioxidant processes. The objective: to determine the clinical effectiveness of combined metabolic therapy with domestic drugs meldonium, ethylmethylhydroxypyridine succinate and armadin in the complex treatment of military personnel with IHD. Materials and methods. The study included 36 military personnel with coronary artery disease with stable angina pectoris of functional class II–III. Patients were treated in the cardiology department of the Military Medical Clinical Treatment and Rehabilitation Center (Irpin). All examined patients were male, the average age was 43.7 ± 2.7 years, the duration of the disease was 4.2 ± 2.3 years, the onset of angina attacks was 39.6 ± 2.8 years. All patients received standard therapy in accordance with the ESC recommendation. Additionally intravenous drip infusions of meldonium (100 mg/ml, 5 ml per 100.0 saline), ethylmethylhydroxypyridine succinate (50 mg/ml, 2 ml intravenously in a 1:2 dilution in saline, slowly in a jet) and armadin (300 mg, 1 tablet in the evening for 2 weeks, then 1 tablet solution twice a day for 4 weeks) were prescribed. The effectiveness of the prescribed complex was monitored based on the dynamics of clinical status, bicycle ergometry indicators, and Holter ECG monitoring before the start of treatment and after 14–16 days. Results. The use of metabolic therapy significantly improved the general condition of patients, reduced the number of angina attacks, and reduced the need for nitroglycerin tablets. Analysis of the sample with dosed physical activity before the start of therapy revealed a significant percentage of patients with ST segment depression of 2 mm at the height of physical activity, and the total relative number of patients with ST segment depression of 1.5–2 mm was 72.2%. During the repeated examination ST segment depression was not determined in 94.4% of patients. Before treatment, rhythm disturbances in the form of supraventricular and ventricular extrasystoles were recorded on the background of maximum exercise, and after treatment, no rhythm disturbances were detected. In the dynamics of the therapy, it was possible to achieve a decrease in blood pressure (BP) indicators during exercise, the level of systolic BP decreased by 16.4%, and diastolic BP – by 9.4% (p < 0.05). Recovery time significantly decreased by 35.2%, but oxygen consumption and tolerance index significantly increased. Conclusions. The results of the study demonstrated that combination therapy with domestically produced metabolic drugs (meldonium, ethylmethylhydroxypyridine succinate and armadine) with a combination of injectable and tablet forms showed high effectiveness in the treatment of military personnel with coronary artery disease. The combination of drugs that patients received during the study demonstrated good tolerability and the absence of adverse reactions.

ИССЛЕДОВАНИЕ ФУНКЦИОНАЛЬНОЙ ПОДГОТОВЛЕННОСТИ OCR-АТЛЕТОВ РЕСПУБЛИКИ ТАТАРСТАН

The research purpose is to identify the level of functional fitness of the strongest OCR-athletes of the Republic of Tatarstan. Methods and organization of the research. The study involved 9 OCR-athletes with the sports qualification of Candidate for Master of Sports, 1st category and without category. The test included a load on a treadmill (treadban h/p/cosmos) with a smoothly increasing running speed, performed to failure. To determine aerobic performance, the CORTEX MetaLyzer 3B gas analyzer was used, the following parameters were determined: time to reach AT and VO2max; respiratory gas exchange ratio (RER); respiratory depth (l), frequency (1/min) and minute volume of respiration (l/min); respiratory efficiency index (VE/VO2); cardiac performance indices – HR (bpm), stroke (ml) and minute blood volume (l/min); oxygen consumption indices – relative (VO2/kg, ml/min/kg) and absolute (Vmax, l/s) oxygen consumption. Statistical processing of the obtained data was performed using the SPSS 20 program. Research results and their discussion. It was revealed that OCR-athletes are inferior to skiers and track and field athletes in terms of respiratory gas exchange ratio (RER) and relative oxygen consumption, but surpass skiers in terms of time to achieve AT and VO2max, which indicates that OCR-athletes should have high functional fitness and be physically versatile. Conclusion. The functional fitness of OCR-athletes specializing in middle- and long-distance running is a key factor for achieving success in this sport. Athletes must have high endurance to overcome long distances, as well as have good strength, speed and coordination indicators to pass certain obstacles on the track. The conducted research allowed us to determine the level of functional fitness of the strongest OCR-athletes of the Republic of Tatarstan, which in the future can help in developing a methodology for the training process in obstacle races at various distances.

Pathobiochemical aspects of divers barodentalgia

Introduction. During their descent under water, divers may suffer from acute toothache attacks (barodentalgia), creating an emergency that leads to the termination of diving descent. Barodentalgia can be caused by hypoxic process in the pulp of filled teeth under increased intrapulpal pressure.Objective. To reveal the peculiarities of hypoxic processes in the pulp of filled teeth under hyperbaric exposure basing on oximetry and fluorescence change parameters.Мaterials and methods. The study involved 34 male divers who underwent a dental examination at the first stage to select individuals for the second stage of the experiment. 24 subjects were selected for the second stage and evaluated for oximetric (mixed blood saturation) and fluorescent (reduced coenzyme NADH, oxidized coenzyme FAD, fluorescent oxygen consumption index — FOCI) indices of filled teeth. The evaluation was performed by optical tissue oximetry (OTO) and laser-induced fluorescence (LIF) methods before and after immersion in a barocamera at pressure of 0.4 MPa while breathing air.Results. Following exposure to increased pressure of the gas medium as compared to the initial values in the filled teeth, the following phenomena were observed: decrease in pulp saturation by 33.7% (p<0.05); increase in NADH by 14.4%; decrease in FAD by 22.9%; increase in FOD by 73.4% (p<0.05).Conclusions. The revealed changes in the indicators of mixed blood saturation, NADH, FAD and FOCI confirm the presence of hypoxic process in the pulp of filled teeth under hyperbaric exposure.

Continuous measurements of respiratory muscle blood flow and oxygen consumption using noninvasive frequency-domain near-infrared spectroscopy and diffuse correlation spectroscopy.

Prior studies of muscle blood flow and muscle-specific oxygen consumption have required invasive injection of dye and magnetic resonance imaging, respectively. Such measures have limited utility for continuous monitoring of the respiratory muscles. Frequency-domain near-infrared spectroscopy and diffuse correlation spectroscopy (FD-NIRS & DCS) can provide continuous surrogate measures of blood flow index (BFi) and metabolic rate of oxygen consumption (MRO2). This study aimed to validate sternocleidomastoid FD-NIRS & DCS outcomes against electromyography (EMG) and mouth pressure (Pm) during incremental inspiratory threshold loading (ITL). Six female and six male healthy adults (means ± SD; 30 ± 7 yr, maximum inspiratory pressure 118 ± 61 cmH2O) performed incremental ITL starting at low loads (8 ± 2 cmH2O) followed by 50-g increments every 2 min until task failure. FD-NIRS & DCS continuously measured sternocleidomastoid oxygenated and deoxygenated hemoglobin + myoglobin (oxy/deoxy[Hb + Mb]), tissue saturation of oxygen (StO2), BFi, and MRO2. Ventilatory parameters including inspiratory Pm were also evaluated. Pm increased during incremental ITL (P < 0.05), reaching -47[-74 to -34] cmH2O (median [IQR: 25%-75%]) at task failure. Ventilatory parameters were constant throughout ITL (all P > 0.05). Sternocleidomastoid BFi and MRO2 increased from the start of the ITL (both P < 0.05). Deoxy[Hb + Mb] increased close to task failure, concomitantly with a constant increase in MRO2, and decreased StO2. Sternocleidomastoid deoxy[Hb + Mb], BFi, StO2, and MRO2 obtained during ITL via FD-NIRS & DCS correlated with sternocleidomastoid EMG (all P < 0.05). In healthy adults, FD-NIRS & DCS can provide continuous surrogate measures of respiratory BFi and MRO2. Increasing sternocleidomastoid oxygen consumption near task failure was associated with increased oxygen extraction and reduced tissue saturation.NEW & NOTEWORTHY This study introduces a novel approach, frequency-domain near-infrared spectroscopy and diffuse correlation spectroscopy (FD-NIRS & DCS), for noninvasive continuous monitoring of respiratory muscle blood flow and metabolic rate of oxygen consumption. Unlike prior methods involving invasive dye injection and magnetic resonance imaging, FD-NIRS & DCS offers the advantage of continuous measurement without the need for invasive procedures. It holds promise for advancing muscle physiology understanding and opens avenues for real-time monitoring of respiratory muscles.

Reproducibility and sex differences in muscle oxygenation during brachial artery occlusion in healthy participants.

Near-infrared spectroscopy (NIRS) measurement is a widely used technique to measure muscle oxygenation. A knowledge of the reproducibility of NIRS measurements is essential for the correct interpretation of data. Our aim was to test the reproducibility and sex differences of NIRS measurements during brachial artery occlusion in healthy participants. An NIRS device was used to measure muscle oxygenation and microvascular function during a 5 min brachial occlusion. Muscle oxygen consumption (mVO2) and tissue saturation index (TSI%) were used. The occlusion test was performed three times on separate days for males (n = 13, 28 ± 8 years) and females (n = 13, 29 ± 7 years). During the occlusion phase, the reproducibility of mVO2 was excellent (intraclass correlation; ICC = 0.90). During the reperfusion phase, the maximal change in TSI% revealed the best reproducibility (ICC = 0.77). There were no sex differences in reproducibility. Male participants had higher muscle oxygenation during occlusion (mVO2, 0.054 ± 0.010 vs. 0.038 ± 0.012 mLO2/min/100 g, p = 0.001, male and female, respectively). There were no sex differences during the reperfusion phase. The reproducibility of NIRS to measure muscle oxygenation and microvascular function during circulation occlusion and reperfusion is good to excellent. Muscle oxygen capacity measured during occlusion is higher in males compared to females, and there are no sex differences in microvascular function during the reperfusion phase.

THE INFLUENCE OF BIOCOMPATIBILITY OF THE EXTRACORPOREAL OXYGENATOR CIRCUIT ON THE DEGREE OF HEMOLYSIS AND OPTIMIZATION OF OXYGEN STATUS IN MINIMALLY INVASIVE CORONARY ARTERY BYPASS GRAFTING

Introduction. A distinctive feature of cardiopulmonary bypass in minimally invasive coronary artery bypass grafting (CABG) is the significantly longer perfusion time, involving active blood drainage from the vein to the cardiotomy reservoir, which carries the risk of hemolysis development. In this context, mechanical hemolysis disrupts the gas transport function of the blood.&#x0D; The aim of the research. Reducing hemolysis and optimizing oxygen status of patients during minimally invasive coronary artery bypass grafting surgeries.&#x0D; Materials and methods. The study included 60 patients, who underwent minimally invasive coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB) under moderate hypothermia. The patients were divided into two groups of 30 individuals each. To improve the biocompatibility of the oxygenator, the circuit in Group 1 (Gr1) was treated with an adaptive composition, while in Group 2 (Gr2), the oxygenator circuit remained untreated. The following parameters were examined: hemoglobin (Hb), hematocrit (Ht), red blood cell count (RBC), oxygen delivery index (DO2I), oxygen consumption index (VO2I), oxygen extraction ratio (O2ER%), oxygen extraction index (O2EI%), venous (SpvO2), and arterial (SpaO2) oxygen saturation, oxygen tension in arterial (PaO2) and venous blood (PvO2), acid-base status of the blood (pH, pCO2,HCO3ˉ, BE), and the degree of hemolysis.&#x0D; Results. Before initiation of cardiopulmonary bypass (CPB), an insignificant increase in O2IE% was observed in Gr1 (26.07±1.57) and Gr2 (27.11±0.81); p=0.875, indicating an increase in tissue oxygen consumption. At the hypothermic stage CPB, both Gr1 and Gr2 demonstrated a statistically significant decrease in Hb, Ht, and RBC levels (p&lt;0.05) due to hemodilution, accompanied by a decrease in IDO2, IVO2, O2IE%, and O2ER% in both groups due to hypothermia. After rewarming, O2ER% in Gr1 (22.91±2.68) and Gr2 (24.59±2.02); p=0.191, and O2EI% in Gr1 (22.92±2.44) and Gr2 (24.61±2.01); p=0.215, were in the normal range. After weaning off cardiopulmonary bypassin Gr2, O2EI% was 27.34±1.97, indicating an increase in oxygen consumption and oxygen extraction. Upon separation from CPB, Gr2 showed a tendency to mild compensated metabolic acidosis, mainly due to HCO3ˉ 21.9±0.3. During the rewarming stage, the hemolysis value was 0.36±0.09in Gr1 and 0.45±0.17 in Gr2 (p&lt;0.001). After CPB, hemolysis was 0.41±0.15 in Gr1 and 0.61±0.22 in Gr2 (p&lt;0.001).&#x0D; Conclusions. Improving the biocompatibility of the extracorporeal oxygenatorcircuit makes it possible to reduce hemolysis and optimise the patient's oxygen status after cardiopulmonary bypass in minimally invasive coronary artery bypass grafting.

Age-dependent energy metabolism and transcriptome changes in urine-derived stem cells

The global population over 60 years old is projected to reach 1.5 billion by 2050. Understanding age-related disorders and gender-specificities is crucial for a healthy aging. Reliable age-related biomarkers are needed, preferentially obtained through non-invasive methods. Urine-derived stem cells (UDSCs) can be easily obtained, although a detailed bioenergetic characterization, according to the donor aging, remain unexplored. UDSCs were isolated from young and elderly adult women (22–35 and 70–94 years old, respectively). Surprisingly, UDSCs from elderly subjects exhibited significantly higher maximal oxygen consumption and bioenergetic health index than those from younger individuals, evaluated through oxygen consumption rate. Exploratory data analysis methods were applied to engineer a minimal subset of features for the classification and stratification of UDSCs. Additionally, RNAseq of UDSCs was performed to identify age-related transcriptional changes. Transcriptional analysis revealed downregulation of genes related to glucuronidation and estrogen metabolism, and upregulation of inflammation-related genes in UDSCs from elderly individuals. This study demonstrates unexpected differences in the UDSCs’ OCR between young and elderly individuals, revealing improved bioenergetics in concurrent with an aged-like transcriptome signature. UDSCs offer a non-invasive model for studying age-related changes, holding promise for aging research and therapeutic studies.

Characteristics of 16-17-year-old young males' physical development in the process of judo club activities.

Aim: To investigate the influence of judo club activities on the physical development indicators of 16-17-year-old young males. Materials and Methods: The research, conducted in 2022-2024, involved 54 young males aged 16-17, who were divided into experimental (EG) and control (CG) groups of 27 each. The physical development was assessed by body weight, hand dynamometry, lung capacity, heart rate, and blood pressure indicators. Cooper, Rufier, Stange, Genchi, vital, strength, body weight, Robinson, and maximum oxygen consumption indices were calculated. Results: The positive influence of judo club activities on the physical development of 16-17-year-old young males was revealed: all studied indicators significantly improved in the EG young males during the experiment. Judo training sessions had the most effective impact on the indicators characterizing the development of the muscular system and the level of strength qualities. At the end of the experiment, young males of the EG showed significantly better physical development than the CG representatives in terms of strength index (by 6.33 %), static endurance of stronger (by 2.07 s) and weaker (2.03 s) hands. According to the indicators characterizing the state of cardiovascular and respiratory systems, the indicators of young males of both groups were significantly the same. Conclusions: It has been established that judo club activities, which were conducted taking into account the age characteristics of 16-17-year-old young males, create the most favorable conditions for the harmonious physical development of boys, promoting their health and preparing them for future educational and professional activities.

Evaluation of the photodynamic effect on the state of microcirculation and oxygenation in periodontal tissues in the treatment of chronic generalized periodontitis

Increasing the effectiveness of treatment of chronic generalized periodontitis using PDT based on clinical and functional substantiation of the effects of a photosensitizer. A clinical and functional study and treatment of moderate chronic generalized periodontitis was carried out in 62 people (26 men and 36 women) aged from 35 to 55 years without a somatic model with an orthognathic occlusion diagnosed according to ICD-10 - K05.3. Of these, 2 groups were divided depending on the type of treatment: Group 1 (main) - patients with moderate chronic generalized periodontitis - 32 people. (17 men and 15 women, average age of the group - 43.2±2.2 years); Group 2 (control) - patients with moderate chronic generalized periodontitis - 30 people. (14 men and 16 women, average age of the group - 44.0±3.3 years). Complex treatment consisted of sanitation of the mouth, removal of dental plaque and curettage of periodontal pockets in group 1, followed by PDT with Revixan gel using a special wired aligner REVIXAN DENTAL LED (16 r). The clinical condition of the periodontium was assessed using the Greene Vermillion Hygienic Index (OHI-S), the Mühlleman Bleeding Index (SBI) modified by Cowell, and the periodontal index PI. To study the state of microcirculation in the gum tissue, the laser Doppler flowmetry (LDF) method was used using the LAKK-M device (NPP «Lazma», Russia). The state of microcirculation was assessed by the microcirculation index (M), which characterizes the level of tissue blood flow; parameter - «σ», which determines the fluctuation of the erythrocyte flow. According to Wavelet analysis of LDF-grams, the shunt index (SH) of blood flow was determined. In the «LDF + spectrometry» mode, oxygenation in periodontal tissues was studied using optical tissue oximetry (OTO), based on the results of which the perfusion saturation index (Sm) and the specific oxygen consumption index (U, %) were determined. According to LDF data, after PDT (group 1), normalization of clinical indices and the level of microcirculation in periodontal tissues was established, which was accompanied by an increase in the level of blood flow (M) and its activity (σ), which persisted after 3 and 6 months. after PDT. The perfusion saturation index (Sm) and specific oxygen consumption (U) increased more significantly after PDT, which persisted after 3 and 6 months. In the control group, the dynamics of indicators was less pronounced. The use of PDT with Revixan gel normalizes the clinical condition of the periodontium, indicators of microhemodynamics and oxygen metabolism.

Evaluation of the results of vestibuloplasty according to microhemodynamics and oxygenation in the mucous membrane of the alveolar ridge

Evaluation of the effectiveness of vestibuloplasty according to microhemodynamics and oxygenation in the mucous membrane of the alveolar ridge. To achieve this goal, a clinical and functional study was carried out in the mucous membrane of the alveolar ridge after vestibuloplasty in 80 patients (35 men and 45 women) aged from 18 to 65 years, average age 41.5±1.9 years, without somatic pathology with a diagnosis according to ICD-10 «K08.1» with an insufficient or completely absent zone of attached keratinized gums, 2 groups were separated from them depending on the type of treatment: mail group comprised 40 people and was divided into 2 subgroups. In subgroup A a free gingival graft (FGG) was used as a covering material (subgroup A) with removable device. In subgroup B (20 people), a collagen matrix and a removable device were used. Control group consisted of subgroup 1 (20 people), in which FGG was used as a covering material, and subgroup 2 (20 people), in which collagen matrix was used. Using laser Doppler flowmetry (LDF), we determined the microcirculation index which characterizes the level of tissue blood flow. Oxygenation studies were carried out using optical tissue oximetry (OTO), determining the perfusion oxygen saturation index and the specific oxygen consumption index. Statistical processing of the results was carried out using MS Excel and MS Access. Analysis of the results of LDF in the main group (subgroup A and B) showed that 3 days after surgery, the level of blood flow (M) and its intensity (σ) decreased by 35% and 54%, and 24% and 49%, respectively, indicating the development of ischemia in the microvasculature which resolved after 14 days in subgroup A and 1 month in subgroup B. In the control group (subgroup 1 and 2), the dynamics of tissue blood flow 3 days after surgery were similar, but microcirculation indicators were restored after 1 and 3 months, respectively. According to optical OTO in the main group 3 days after surgery, oxygenation rates decreased by 36% and 50% (subgroup A) and 20% and 41% (subgroup B) indicating the development of hypoxia in the tissues which resolved after 14 days and 1 month after surgery, respectively. In the control group (subgroup 1 and 2), oxygenation indicators were restored after 1 and 3 months, respectively. After vestibuloplasty using FGG or collagen matrix and a removable denture, microhemodynamics and oxygenation in the mucous membrane of the alveolar ridge restored earlier than in controls.

Chronic supplementation of noni in diabetic type 1-STZ rats: effects on glycemic levels, kidney toxicity and exercise performance

Noni is a fruit with potential medicinal use preventing elevated blood glucose levels in diabetes mellitus. Its effects have been attributed to an antioxidant property in several other diseases. However, the effects of noni-chronic supplementation on exercise performance in the presence of diabetes conditions are not known. Thirty-two male Wistar rats were used to verify the effects of chronic noni (Morinda citrifolia L) juice administration on glycemia, triglyceride levels, and its relation to physical performance. In addition, it was verified if chronic noni supplementation is safe for clinical use through kidney morphology analysis. In half of the rats, diabetes mellitus (DM) was induced with STZ. All rats were submitted to an incremental workload running test (IWT) until fatigued so that oxygen consumption and performance indexes (exercise time to fatigue and workload) could be analyzed before noni administration. Then, the control and DM groups received a placebo (saline solution) or noni juice (dilution 2:1) at a dose of 2 mL/kg once a day for 60 days. The result was four groups: control + placebo (CP), control + noni (CN), DM + placebo (DMP), and DM + noni (DMN). Our dose was based on in previous study by Nayak et al. (2011) that observed a significant reduction in glycemia with 2 ml/kg of the noni juice without any toxicity effect cited. Groups were then given a third IWT to verify the effect of the noni juice on exercise performance (exercise time to fatigue, workload, maximal oxygen consumption) and glycemia. Twenty-four hours after the third test, all animals were euthanized and blood and kidneys were removed for posterior analysis. The DM induction with STZ impaired the performance by 39%. Noni administration improved the time to fatigue and workload in DM rats beyond reducing hyperglycemia. These results could be associated with an improved energy efficiency promoted by noni ingestion, since the oxygen consumption was not different between the groups, although the exercise was longer in animals with noni ingestion. Our results provided evidence that chronic noni administration causes kidney damage since increased Bowman’s space area in the control rats, suggesting glomerular hyperfiltration at the same magnitude as the non-treated DM group.In conclusion, chronic noni ingestion promoted glycemic control and improved the performance in DM rats but caused kidney toxicity.

#2567 ASSOCIATION OF IMBALANCE OF MYOCARDIAL OXYGEN SUPPLY/DEMAND WITH MYOCARDIAL INJURY IN END STAGE KIDNEY DISEASE PATIENTS

Abstract Background and Aims It is well known that oxygen transport ability is impaired in patients with anemia, low hemoglobin (Hb) level, whereas the double product (DP, bpm*mmHg), consisting of the systolic blood pressure (SBP) multiplied by the heart rate (HR), is an index of myocardial oxygen consumption. The combination of these two markers could be a potential marker for balance of myocardial oxygen supply and demand. Therefore, we hypothesized that the balance of these two markers may lead to myocardial damage in end-stage kidney disease (ESKD) patients who is susceptible to vulnerable heart in oxygen balance. The purpose of this study is to examine the association of balance of DP and Hb with myocardial injury in ESKD patients. Method A single-center, cross-sectional study has conducted. From December 2010 to November 2021, 327 consecutive ESKD patients started maintenance hemodialysis (HD). Among them, 44 patients met the exclusion criteria as follows: (1) missing data of cardiac troponin T (cTnT); (2) complicating acute cardiac syndrome; (3) death during hospitalization for HD initiation, a total of 283 ESKD patients were enrolled into the study finally. The patients were divided four groups according to the high or low of Hb level of 9 g/dL and DP 12500, a median of our patients, and named low-DP/high-Hb; G1, low-DP/low-Hb; G2, high-DP/high-Hb; G3, and high-DP/low-Hb; G4. The patients with G1 group were defined as a well oxygen balanced group, whereas those with G4 was defined as an imbalance of oxygen supply and demand group. Based on the results of previous study, cTnT cut off for myocardial injury was serum cTnT ≧0.15 ng/mL. Odds ratio (OR) for myocardial injury was calculated in each group compared with well oxygen balanced group by logistic regression analysis. Results Median age was 72 years, 71% of them were male, 52.6% had diabetes. Mean Hb level was 9.09 ± 1.61, and median DP was 12144 (25% tile 10540, 75% tile 14688). Median cTnT was 0.083 (25% tile 0.057 and 75% tile 0.13), and 20.4% of patients were defined as suffering from myocardial injury latently. In the adjusted model, the odds for myocardial injury was significantly increasing in high-DP compared with low-DP (OR: 1.87, p = 0.049), while low-Hb did not show significant increment of odds for myocardial injury compared with high-Hb. As shown in the Table 1, compared to well-balanced group (G1), OR increased by exposing only high-DP (G3), however it was not statistically significant (OR 1.20, p = 0.68). Interestingly, by exposing with high-DP with low-Hb simultaneously (G4), synergistic increased OR was found compared with well-balanced (G1) group (OR 3.07, 95%CI 1.24-7.62, p = 0.015). Furthermore, these associations were enhanced and weakened if Hb cut-off level became to be lower (Hb 8 g/dL) and higher (Hb 10 g/dL), as shown in Tables 2, 3. Conclusion Imbalance of oxygen supply (Hb) and demand (DP) was associated with myocardial injury in incident HD patients. Appropriate control of anemia, SBP and HR may have possibility to prevent myocardial injury. Especially we need to pay attention more to the Hb level if BP and HR control is insufficient. Tables 1, 2, 3. Odds ratio for cTnT≧0.15 in four groups divided by DP and Hb (adjusted for age, male, CRP, albumin, diabetes mellitus).

Effect of Soaking Time on the Spontaneous Combustion Characteristics of Lignite

ABSTRACT When mining deep coal seams, the overlying mined-out area must be pumped and drained, and the remnant coal in the mining void area is vulnerable to spontaneous combustion via water immersion and air drying. To investigate the effect of soaking time on the spontaneous combustion characteristics of lignite, low-temperature N2 adsorption experiments and Fourier transform infrared spectroscopy (FTIR) experiments were used in this study to investigate the changes in pore structure and functional group content of coal samples by increasing the soaking time. Based on programmed warming experiments, macroscopic characteristic indicators of coal spontaneous combustion (CSC) oxidizability, such as the oxygen consumption rate and index gas, were derived. Results showed that the effect of soaking caused the total pore volume and specific surface area of lignite to increase to different degrees, which enhanced the adsorption capacity of coal to oxygen and improved the effective contact of oxygen with the active sites on the coal surface. However, there was no consistency in the effect of different soaking times on the content of reactive functional groups of the coal, with higher methyl and methine contents after 60 days of soaking (S60) and 120 days of soaking (S120) than in the raw coal (RC), and less in 90 days of soaking (S90). The propensity of coal to spontaneously combust is determined by both the pore structure and reactive functional groups, which shows the propensity of spontaneous combustion S60>S120>RC>S90. Results from this study are important in understanding the mechanism of CSC of water-soaked lignite in mined-out areas and can provide theoretical guidance to prevent CSC in mining areas.

Comparison of Hemodynamic Effects of Dobutamine and Ephedrine Infusions in Isoflurane-Anesthetized Horses.

The objective of this study was to compare the hemodynamic effects of dobutamine and ephedrine during the management of anesthesia-related hypotension in healthy horses. Thirteen horses underwent general anesthesia with isoflurane and were randomly divided into two different groups, one of which received a dobutamine constant rate infusion (CRI) (1 µg/kg bwt/min) and the other received an ephedrine CRI (20 µg/kg bwt/min) when hypotension (<60 mmHg) was identified, following up to 15 min after the blood pressure reached 70 mmHg. All horses were equipped with a pulmonary artery catheter and a peripheral artery catheter, and multiparameter monitoring commenced as soon as they were under mechanical ventilation. Hemodynamic parameters were recorded, while tissue perfusion markers (peripheral oxygen saturation, arterial oxygen partial pressure, arterial carbon dioxide partial pressure, arterial pH, arterial plasma bicarbonate concentration, arterial oxygen saturation, mixed venous oxygen saturation, mixed venous oxygen content, arterial oxygen content, arteriovenous oxygen difference, oxygen delivery index, oxygen consumption index, and oxygen extraction ratio), serum lactate concentration, and troponin I concentrations were analyzed before the start of infusions (T0), when the blood pressure reached 70 mmHg (T1), and 15 min after T1 (T2). The time to restore the arterial pressure was similar in both groups (p > 0.05); however, the heart rate was higher in the ephedrine group (p = 0.0098), and sinus bradyarrhythmia occurred in the dobutamine group. Furthermore, both experimental protocols increased cardiac output (p = 0.0012), cardiac index (p = 0.0013), systemic vascular resistance (p = 0.008), systemic vascular resistance index (p < 0.001), and ameliorated perfusion markers. In the dobutamine group, the pulmonary artery wedge pressure (p < 0.001) and systolic index (p = 0.003) were elevated, while the arteriovenous oxygen difference was reduced in the ephedrine group (p = 0.02). Troponin I was used as a myocardial injury indicator, and did not differ between moments or between groups (p > 0.05). We concluded that both drugs were effective and safe to treat anesthetic hypotension under the conditions of this study.

PHYSIOLOGICAL AND BIOCHEMICAL PARAMETERS OF NORMOBARIC HYPOXIA STRESS IN HUMANS

The aim of the study is to examine the dynamics of the sympathoadrenal and adrenocortical components of acute normobaric hypoxia stress and their correlation with some physiological and biochemical parameters characterizing the energy metabolism in humans.&#x0D; Materials and methods. Fourteen trial subjects were exposed to 40-minute hypoxia while breathing nitrogen-oxygen mixture containing 9 % of oxygen. At 5th, 10th, 20th, and 40th minutes of hypoxia, blood was taken from the cubital vein for further analysis. The authors determined a number of physiological parameters, such as pulse rate; blood pressure; oxygen consumption; rheographic index of cerebral blood flow. We also evaluated epinephrine, norepinephrine, cortisol, lactate and glucose blood levels at the time of sampling. The authors estimated the increase in parameters at control points compared to baseline, as well as the correlation of the increase in various indicators.&#x0D; Results. A significant increase in blood epinephrine (max. min 20), norepinephrine (max. min 10) and lactate (max. min 40) was found in trial subjects under hypoxia compared to baseline parameters. A significant increase in oxygen consumption and rheographic index of cerebral blood flow was established under hypoxia (max. min 40). The longer the trial subject was exposed to hypoxia, the more the degree of conjugation in the dynamics of sympathoadrenal response, cerebral blood flow, and energy metabolism (lactate, glucose) was.&#x0D; Conclusion. The obtained facts prove the heterochrony of sympathoadrenal and adrenocortical stress components in the dynamics of the human body response to acute normobaric hypoxia. With hypoxia development, the impact of the adrenergic component on mobilizing the energy of glycolytic processes increases.

Intensity Differences of Resistance Training for Type 2 Diabetic Patients: A Systematic Review and Meta-Analysis.

Resistance training is used as adjunctive therapy for type 2 diabetes (T2DM), and the aim of this study was to investigate the differences in the treatment effects of different intensities of resistance training in terms of glycemia, lipids, blood pressure, adaptations, and body measurements. A comprehensive search was conducted in the PubMed, EMBASE (Excerpta Medica dataBASE), EBSCO (Elton B. Stephens Company) host, Cochrane Library, WOS (Web of Science), and Scopus databases with a cut-off date of April 2022, and reference lists of relevant reviews were also consulted. The literature screening and data extraction were performed independently by two researchers. RoB2 (Risk of bias 2) tools were used for the literature quality assessment, the exercise intensity was categorized as medium-low intensity and high intensity, and the meta subgroup analysis was performed using R Version. A fixed or random effects model was selected for within-group analysis based on the heterogeneity test, and a random effects model was used for the analysis of differences between subgroups. A total of 36 randomized controlled trials were included, with a total of 1491 participants. It was found that resistance training significantly improved HbA1c (glycated hemoglobin), fasting blood glucose, TG (triglycerides), TC (total cholesterol), and LDL (low-density lipoprotein cholesterol) levels in patients with T2DM and caused a significant reduction in systolic blood pressure, percent of fat mass, and HOMA-IR (homeostatic model assessment for insulin resistance) indexes. The effects of high and medium-low intensity resistance training on T2DM patients were different in terms of HOMA-IR, maximal oxygen consumption, weight, waist-to-hip ratio, and body mass indexes. Only medium-low intensity resistance training resulted in a decrease in HOMA-IR. In addition to weight (MD = 4.25, 95% CI: [0.27, 8.22], I2 = 0%, p = 0.04; MD = -0.33, 95% CI: [-2.05, 1.39], I2 = 0%, p = 0.76; between groups p = 0.03) and HOMA-IR (MD = 0.11, 95% CI: [-0.40, -0.63], I2 = 0%, p = 0.85; MD = -1.09, 95% CI: [-1.83, -0.36], I2 = 87%, p = < 0.01; between groups p = 0.0085), other indicators did not reach statistical significance in the level of difference within the two subgroups of high intensity and medium-low intensity. The treatment effects (merger effect values) of high intensity resistance training were superior to those of medium-low intensity resistance training in terms of HbA1c, TG, TC, LDL levels and diastolic blood pressure, resting heart rate, waist circumference, fat mass, and percentage of fat mass. Therefore, high intensity resistance training can be considered to be a better option to assist in the treatment of T2DM and reduce the risk of diabetic complications compared to medium-low intensity resistance training. Only one study reported an adverse event (skeletal muscle injury) associated with resistance training. Although results reflecting the difference in treatment effect between intensity levels reached no statistical significance, the practical importance of the study cannot be ignored.

EFEITOS DO TREINAMENTO DE ALTA INTENSIDADE NA RESISTêNCIA DOS JOGADORES DE BASQUETEBOL

ABSTRACT Introduction: The aerobic endurance training of sports athletes has become the focus of research in institutions and related units. One of the recent proposals is high-intensity interval training to develop athletic aerobic endurance. Objective: Study the effect of high-intensity interval training on aerobic endurance in basketball players. Methods: Fifteen athletes from a university were randomly selected and divided into a high-intensity interval training group, a moderate-intensity continuous training group, and a low-intensity continuous training group, with the control of external influence factors. The indicators analyzed were the average aerobic endurance index of maximal oxygen consumption, average anaerobic capacity, and average maximal power output. The data were obtained before and after the experiment. They were compared and discussed using statistical analysis. Results: The average maximal oxygen consumption in the three training groups increased significantly, and the effect was most evident under the high-intensity intermittent training conditions. This training method could increase the maximal exercise time of the normal groups by up to two times. Conclusion: Intermittent high-intensity training can effectively improve the aerobic endurance of basketball players. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

INFLUÊNCIA DAS ARTES MARCIAIS SOBRE O FÍSICO DOS ESTUDANTES UNIVERSITÁRIOS PRATICANTES

ABSTRACT Introduction The continuous practice of martial arts can lead to significant changes in the functioning of respiratory organs in the long term. This habit can improve the body’s physical development, including the immune system. Objective To investigate the influence of martial arts classes on the physical fitness of college students who practice them. Methods 53 college students are evaluated. Influencing factors are martial arts dedication and training time. The experiment assesses cardiopulmonary function (cardiac function capacity, maximal oxygen consumption, blood pressure, heart rate, and other indexes). The secondary exercise stress tolerance test method was used to investigate cardiopulmonary exercise function in college students. Results 90% of the cardiopulmonary function assessment of the martial arts exercise group is excellent. The practitioners’ heart rate and maximum oxygen volume are significantly higher (P&lt;0.05). Systolic and diastolic blood pressure between the groups did not show significant changes (&lt; 120/80mmhg). Martial arts did not change systolic, diastolic blood pressure, or heart rate in the long term. Conclusion Martial arts education has a good influence on students’ physical fitness and significantly impacts students’ strength and vital capacity. Evidence Level II; Therapeutic Studies – Investigating the results.

Interaction between reduced pH and multiple stressors affects the physiology of the fiddler crabLeptuca thayeri(Rathbun, 1900) (Decapoda: Brachyura: Ocypodidae)

AbstractIncreasing ocean acidification combined with other impacts may cause changes in homeostatic mechanisms of intertidal invertebrates. Stressors do not act in isolation, and experimental work is needed to assess their synergistic potential. We evaluated the effect of exposure to multiple stressors on the survival, osmoregulation, metabolism, Q10, excretion, hepatosomatic index, and energy substrate oxidation on of the fiddler crab Leptuca thayeri (Rathbun, 1900). Crabs were exposed to two pH values (7.0, 6.3) combined with temperatures (20, 25, 30, 35, 40 °C) and these pH values combined with salinities (10, 20, 30, 40, and 50 psu) during acute exposure. All individuals died at 40 °C. Crabs osmoregulated, suggesting that the factors evaluated did not affect salt absorption or secretion. Individuals were weak hyperosmorregulators at lower salinities in the pH 7 control, but they became strong hyperosmoregulators at acidified pH 6.3. Alterations in oxygen consumption and hepatosomatic index were observed in individuals exposed to the acidified pH combined with temperatures or salinities, compared to those kept in the control pH. Q10 was elevated under an acidified pH, with crabs using proteins and lipids as energy substrates. The interaction between reduced pH and temperature or salinity thus affected physiological mechanisms related to the energetic metabolism, but elevated temperatures are more limiting because they affected survival. These physiological effects of acute exposure offer clues about extreme climatic events, which have a short duration but can affect the related energy demands.