Plasma Lactate Concentrations Research Articles

Assessment of shock index in healthy cats and in cats presenting to an emergency room with shock.

To prospectively compare the shock index (SI) in a population of healthy cats with a population of cats presenting to the emergency room (ER) deemed to be in a state of shock. Prospective cohort study of cats. University teaching hospital. Twenty-seven healthy control cats were enrolled to establish a reference interval, and 27 cats were enrolled that were presented to the ER with clinical signs of shock. Shock was defined as abnormalities in at least 2 of the following inclusion criteria: plasma lactate concentration > 2.5mmol/L; peripheral vasoconstriction (at least 2 of the following parameters: capillary refill time >3s, rectal-interdigital temperature gradient [RITG] >8°C, femoral pulse not palpable, pale mucous membranes); or systolic blood pressure (SBP) < 100mmHg. Upon presentation, SI (SI=heart rate [HR]/SBP), HR, SBP, and RITG were recorded in both groups, along with peripheral venous blood sampling for lactate measurement. The mean SI in the control group was 1.47±0.2 and was 1.87±0.47 in the shock group (P=0.001). Using equality in sensitivity and specificity of 0.7, an SI cutoff point of 1.54 (95% confidence interval [CI]: 0.49-0.86) was determined with an estimated area under the receiver operating characteristic curve of 0.78 (95% CI: 0.65-0.90). HR, plasma lactate concentration, and RITG did not differ between the groups. Systolic arterial blood pressure (P=0.01), rectal temperature (P=0.02), and interdigital temperature (P=0.04) differed significantly. The SI is a noninvasive, easy, and reliable parameter for distinguishing cats in shock from normal cats.

Determination of reference intervals of venous blood gas and acid-base parameters in clinically healthy awake cats.

Venous blood gas and acid-base analysis is often performed in cats and requires appropriate reference intervals (RIs) for interpretation. The currently available RIs were created from small numbers of cats, while current guidelines suggest that a minimum number of 40 samples is required for the creation of an accurate/appropriate RI. In 41 healthy awake cats, pH, PvCO2, PvO2, sodium, potassium, ionized calcium, chloride, glucose, and plasma lactate concentrations were measured, while bicarbonate, standardized base excess, and anion gap were calculated. These data were used to calculate RIs, using a statistical approach that conforms to the American Society for Veterinary Clinical Pathology guidelines. RIs for venous blood gas and traditional acid-base analysis from a relatively large population of healthy cats are now available for clinical use and standardized for future research studies.

Potentials of Presepsin as a Novel Sepsis Biomarker in Critically Ill Adults: Correlation Analysis with the Current Diagnostic Markers.

Background: Sepsis is a major cause of patient death in intensive care units (ICUs). Rapid diagnosis of sepsis assists in optimizing treatments and improves outcomes. Several biomarkers are employed to aid in the diagnosis, prognostication, severity grading, and sub-type discrimination of severe septic infections (SSIs), including current diagnostic parameters, hemostatic measures, and specific organ dysfunction markers. Methods: This study involved 129 critically ill adults categorized into three groups: sepsis (Se = 48), pneumonia (Pn = 48), and Se/Pn (33). Concentrations of five plasma markers (IL-6, IL-8, TREM1, uPAR, and presepsin) were compared with 13 well-established measures of SSI in critically ill patients. These measures were heart rate (HR), white blood count (WBC), C-reactive protein (CRP), procalcitonin (PCT), lactate plasma concentrations, and measures of hemostasis status (platelets count (PLT), fibrinogen, prothrombin time (PT), activated partial thromboplastin time (APTT), international normalization ratio (INR) and D-dimer). Plasma bilirubin and creatinine served as indicators of liver and kidney dysfunction, respectively. Results: Promising roles for these biomarkers were found. The best results were for presepsin, which scored 10/13, followed by IL-6 and IL-8 (each scored 7/13), and the worst were for TREM-1 and uPAR (scored 3/13). Presepsin, IL-6, and IL-8 discriminated between the SSI sub-types, whilst only presepsin correlated with bilirubin and creatinine. uPAR was positive for kidney dysfunction, and TREM-1 was the only indicator of artificial ventilation (AV). Conclusions: Presepsin is an important potential biomarker in SSIs. However, further work is needed to define this marker's diagnostic and prognostic cutoff values.

Effect of acetate- and lactate-containing intravenous fluid on acid-base status, electrolytes and plasma lactate concentration in dehydrated cats.

Acetate (ACE) and lactate (LAC)-containing balanced resuscitation fluids are commonly used for fluid therapy in cats. These fluids can influence acid-base and electrolyte status. This prospective randomised study compared two balanced crystalloid solutions regarding their effect on acid-base status, electrolytes and LAC concentrations in dehydrated cats after intravenous fluid therapy. A total of 100 client-owned cats presenting to the emergency service with dehydration ⩾5% due to diarrhoea, vomiting or anorexia were included in this study. They were randomised to receive either ACE- (Sterofundin ISO; B Braun Vet Care) or LAC-containing (Ringer-Laktat nach Hartmann; B. Braun Vet Care) fluids for rehydration. Exclusion criteria were age <6 months, severe electrolyte abnormalities, severely increased creatinine or bolus therapy, and decompensated heart disease and liver diseases. Vital parameters were assessed and venous blood gas analysis was performed before and after fluid therapy. Data were analysed using the Mann-Whitney U-test and the Wilcoxon matched-pairs signed-rank test. The significance level was set at P ⩽0.05. Post-rehydration pH normalised, and bicarbonate and base excess increased in both groups. Anion gap and LAC and potassium concentrations decreased in both groups. No difference in electrolyte, acid-base status and LAC was observed between cats receiving ACE and cats receiving LAC. Both fluids have similar effects on dehydrated cats' acid-base status and electrolyte and LAC concentrations. No significant differences in values were found between ACE- and LAC-containing resuscitation fluids. Blood LAC concentration decreased in both groups.

Lower Plasma Lactate Concentrations After Training Support the Hypothesis of Improved Metabolic Flexibility in Male Long-Term Selected Marathon Mice Compared to Unselected Controls.

Metabolic flexibility describes the capability to switch between oxidative fuels depending on their availability during diet or exercise. In a previous study, we demonstrated that in response to training, marathon (DUhTP) mice, paternally selected for high treadmill performance, are metabolically more flexible than unselected control (DUC) mice. Since exercise-associated metabolic flexibility can be assessed by indirect calorimetry or partially by circulating lactate concentrations, we investigated these parameters in DUhTP and DUC mice. Therefore, males of both lines completed a three-week high-speed treadmill training or were physically inactive (sedentary) before being placed in a metabolic cage for three days (one day of acclimatization, two days with monitoring), measuring CO2 and O2 to calculate respiratory quotient (RQ) and fatty acid oxidation (FATox). Circulating blood lactate concentrations were determined. Training resulted in a lower RQ in DUhTP and an increased RQ in DUC mice compared to their sedentary counterparts. Increased FATox rates and lower lactate concentrations were observed in exercised DUhTP but not in DUC mice, indicating a shift to oxidative metabolism in DUhTP and a glycolytic one in DUC mice. Therefore, improved metabolic flexibility in DUhTP mice is verifiable up to three days after training.

Daily glucose variability is associated with intrahepatic fat content, β cell sensitivity, and biomarkers of glycolysis in youth with obesity.

Pediatric obesity is associated with insulin resistance, which, in turn, impacts glucose and lipid metabolism. This study sought to assess how glucose variability relates to intrahepatic fat content, β cell insulin sensitivity, and glycolysis in youth with obesity. A total of 27 youth with obesity (11 girls, BMI percentile, median [25th-75th percentiles]: 99.0 [97.9-99.0]) wore a continuous glucose monitoring device for 10 days and underwent a 3-h oral glucose tolerance test. β cell function was assessed using the oral minimal model, and liver proton density fat fraction was measured by magnetic resonance imaging. Average sensor-derived glucose and glucose standard deviation (STDEV) and coefficient of variation (CV) were associated with liver proton density fat fraction(p = 0.0130, p = 0.0005, and p = 0.0028, respectively). First-phase insulin secretion, basal insulin secretion, and insulin sensitivity were associated with STDEV (p = 0.0344, p = 0.0091, and p = 0.0031, respectively) and CV (p = 0.0128, p = 0.0012, and p = 0.0022, respectively). STDEV and CV were also associated with 2-h glucose (p = 0.0067 and p = 0.0324, respectively) and plasma lactate (p = 0.0030 and p = 0.0123, respectively). Daily glucose variability is associated with the degree of intrahepatic fat content, postprandial glucose, and plasma lactate concentrations.

Moderately cool environment with rain and wind increases cold strain and energy expenditure via carbohydrate oxidation during running exercise.

Outdoor exercise often proceeds despite rain and wind in cool conditions. The aim of this study was to investigate the effects of rain with wind on physiological responses during running exercise at 70% V̇O<inf>2max</inf> in cool conditions. Eleven healthy men exercised on a treadmill at 70% V̇O<inf>2max</inf> intensity for 60 min under conditions of 10 mm/h rain and 3 m/sec wind (RW) or not (CON) at 10°C in a climatic chamber able to simulate various temperature, humidity, rain, and wind conditions. Body temperature, expired air, and blood samples were measured at rest and exercise. Rectal temperature, mean weighted skin temperature, and thermal sensation were all significantly lower in RW than in CON during exercise (all P<0.05). Oxygen uptake was significantly higher in RW than in CON during exercise (all P<0.05). Participants' rating of perceived exertion was significantly higher in RW than in CON at 50 and 60 min (P<0.05). Respiratory exchange ratio was significantly higher in RW than in CON at 10, 20, and 40 min. Plasma lactate concentration and plasma norepinephrine levels were significantly higher in RW than in CON during exercise (both P<0.05). Rain with wind intensified body heat loss, and energy expenditure and carbohydrate oxidation increased as the body cooled. These conditions may decrease exercise performance.

Social facilitation of trotting: Can horses perceive and adapt to the movement of another horse?

Exercise intensity is prone to be self-regulated in horses exercising freely. The main drivers include social, feeding and escape behaviors, as well as the operant conditioning. We hypothesized that self-regulated exercise intensity may increase due to the presence of another horse exercising ahead. Seven horses were assigned to a 2x2 crossover trial following treadmill familiarization. Video images of a trotting horse were displayed on the wall in front of the experimental unit (Visual), which was positioned in the treadmill. Physiological and behavioral markers were further compared with a control visual stimulus (Co), comprising a racetrack image without horses. Horses were sampled during a constant load exercise test (1) at rest (baseline), (2) after the warm-up (0 - 10th minute) and (3) after visual stimulation or control (10th- 12th minutes of the SET) to quantify plasma lactate and glucose concentration, heart rate, head angle, as well as behavioral markers. Following visual stimulation, heart rate (130.8 ± 27.8 b.p.m.) was higher than control (84.7 ± 15.1 b.p.m., P = .017), as was plasma lactate (Visual - 5.28 ± 1.48 mg/dl; Co -3.27 ± 1.24 mg/dl, P = .042) and head angle (Visual - 36.43 ± 3.69°; Co -25.14 ± 4.88°, P = .003). The prevalence of "ears forward" behavior was also higher following Visual (100% - 7/7) than Co (14% - 1/7, P = .004). These results suggest that visual stimulus (1) was safe and well tolerated and (2) prompted the anaerobic lactic pathways and shifted the behavior to a vigilant state. In conclusion, horses were able to perceive and adapt to a social environment. Our findings validate the use of social facilitation of trotting to encourage horses to move forward avoiding the use of the whip.

Serial paired arterial and jugular venous point-of-care values in dogs undergoing manual basic life support.

To evaluate differences in point-of-care (POC) variables obtained from arterial and jugular venous blood in dogs undergoing manual basic life support (BLS) and report changes over time. Experimental study. Small animal research facility. Twenty-four purpose-bred research dogs. Dogs were anesthetized, and arterial catheters were placed before euthanasia. One minute after cardiopulmonary arrest, BLS consisting of manual chest compressions and ventilation delivered via endotracheal intubation, face mask, mouth-to-nose, or no ventilation was initiated. Paired arterial and jugular venous blood samples were obtained for POC testing before euthanasia (T0), at 3minutes (T3), and at 6minutes (T6) into BLS. The association of POC variables with arterial or venous sample type while controlling for type of ventilation and sampling timepoint was determined using a generalized linear mixed model. Variables obtained from arterial and venous blood samples were compared over time using repeated measures ANOVA or Friedman test. Pao2, anion gap, potassium, chloride, glucose concentration, and PCV were significantly higher in arterial blood samples compared with venous samples (P<0.03). By T6, arterial glucose concentration, arterial and venous base excess, venous pH, and plasma lactate, potassium, creatinine, bicarbonate, and sodium concentrations were significantly increased, and arterial and venous Po2, ionized calcium concentration, PCV, and total plasma protein concentration were significantly decreased from T0 (P<0.05). Although statistically significant, arteriovenous differences and changes in POC blood variables during BLS were small and not clinically relevant over time. Given the challenges of arterial blood sampling, it may be reasonable to pursue venous blood sampling during CPR. Further studies in dogs undergoing BLS and advanced life support are needed to better understand the potential clinical role of POC testing during CPR.

Morphology and metabolic traits related to swimming performance in Australasian snapper (Chrysophrys auratus) selected for fast growth.

Changes in body shape are linked to swimming performance and become relevant for selective breeding programmes in cultured finfish. We studied how the selection for fast growth could affect phenotypes by investigating the relationship between swimming performance and body shape. We also investigated how swimming might affect plasma metabolite concentrations. Critical swimming speed (UCrit), body traits (e.g., BW, body weight; BL, body length; K, condition factor), and plasma lactate and glucose concentrations were evaluated in two cohorts of Australasian snapper (Chrysophrys auratus): one derived from wild broodstock (F1), and the other selected for fast growth (F4). UCrit tests (n = 8) were applied in groups of 10 snapper of similar BW (71.7 g) and BL (14.6 cm). The absolute or relative UCrit values of both cohorts were similar (0.702 m⋅s-1 and 4.795 BL⋅s-1, respectively), despite the F4 cohort displaying a higher K. A positive correlation between K and absolute UCrit (Pearson's r = 0.414) was detected in the F4 cohort, but not in the F1 cohort, which may be linked to differences in body shape. A negative correlation between relative UCrit and body size (Pearson's r between -0.682 and -0.501), but no correlation between absolute UCrit and body size, was displayed in both cohorts. Plasma lactate and glucose concentrations were higher in the F4 cohort at UCrit. Whether a longer selective breeding programme could result in more changes in body shape, potentially affecting swimming performance, should be explored, along with the potential outcomes of the differences in metabolic traits detected.

Endocrine data provide further evidence of physiologic derangement in sea turtles affected by the Deepwater Horizon oil spill

This study was conducted to characterize the adrenocortical and thyroid status of Kemp’s ridley sea turtles Lepidochelys kempii that were affected by the Deepwater Horizon oil spill. A plasma aldosterone assay was validated for L. kempii, and it was used along with previously validated assays for corticosterone and free thyroxine to assess hormone concentrations of 30 L. kempii that were hospitalized due to oil exposure, representing 2 severities of oiling (lightly or heavily oiled). Hormone concentrations were also assessed in relation to 8 clinical biochemical analytes. Analysis of paired samples indicated that oiled turtles had significantly higher initial aldosterone and corticosterone concentrations, which declined during convalescence (average 96 and 90% decrease, respectively). Thyroxine concentrations significantly increased between admission and convalescence (average 65% increase). Initial biochemical data indicated significantly higher plasma potassium, ionized magnesium, and lactate concentrations compared to convalescent values. Aldosterone concentrations were positively correlated with corticosterone, negatively correlated with free thyroxine, and variably correlated with several clinical biochemical analytes. Results of this study indicate that L. kempii had robust adrenocortical activity after oiling, capture, and transport to the hospital, regardless of the degree of oiling, resulting in very high plasma concentrations of aldosterone and corticosterone. This study also confirms that aldosterone can be reliably measured in sea turtle plasma samples, providing another diagnostic tool for the physiologic assessment of this Critically Endangered species.

Relationship between Neonatal Cerebral Fuels and Neurosensory Outcomes at 3 Years in Well Babies: Follow-Up of the Glucose in Well Babies (GLOW) Study

Plain Language SummaryIn the Glucose in Well babies and their later Neurodevelopment (GLOWiNg) study, we investigated whether the availability of brain fuels in healthy term babies during the first 5 days after birth was associated with their neurodevelopmental progress at 3 years of age. We had measured plasma glucose, lactate, and beta-hydroxybutyrate concentrations when the children were babies, as these are the most common brain fuels. We used the Ages and Stages questionnaire, which is completed by parents, to assess the child’s development in areas including communication, motor skills (fine and gross), and problem solving.We studied 64 families whose babies were part of the Glucose in Well Babies (GLOW) study in New Zealand. Using both structural equation modelling and linear regression, we found that even though many babies experienced episodes of low plasma glucose concentrations, there was no detectable relationship between these episodes and developmental progress at 3 years of age. We explored other factors, including glucose concentrations, total fuels available, and the duration of low glucose episodes, and found no significant associations. Our results suggest that in healthy term babies, episodes of low glucose concentrations in the first days after birth may be part of the normal metabolic transition after birth and may not have long-term implications for neurodevelopment. However, larger studies using different assessment tools are needed to confirm these findings.

Effects of restrictive fluid therapy on the time to resolution of hyperlactatemia in ICU patients with septic shock. A secondary post hoc analysis of the CLASSIC randomized trial

PurposeThe aim of this study was to examine the effects of intravenous (IV) fluid restriction on time to resolution of hyperlactatemia in septic shock. Hyperlactatemia in sepsis is associated with worse outcome. Sepsis guidelines suggest targeting lactate clearance to guide fluid therapy despite the complexity of hyperlactatemia and the potential harm of fluid overload.MethodsWe conducted a post hoc analysis of serial plasma lactate concentrations in a sub-cohort of 777 patients from the international multicenter clinical CLASSIC trial (restriction of intravenous fluids in intensive care unit (ICU) patients with septic shock). Adult ICU patients with septic shock had been randomized to restrictive (n = 385) or standard (n = 392) intravenous fluid therapy. The primary outcome, time to resolution of hyperlactatemia, was analyzed with a competing-risks regression model. Death and discharge were competing outcomes, and administrative censoring was imposed 72 h after randomization if hyperlactatemia persisted. The regression analysis was adjusted for the same stratification variables and covariates as in the original CLASSIC trial analysis.ResultsThe hazard ratios (HRs) for the cumulative probability of resolution of hyperlactatemia, in the restrictive vs the standard group, in the unadjusted analysis, with time split, were 0.94 (confidence interval (CI) 0.78–1.14) at day 1 and 1.21 (0.89–1.65) at day 2–3. The adjusted analyses were consistent with the unadjusted results.ConclusionIn this post hoc retrospective analysis of a multicenter randomized controlled trial (RCT), a restrictive intravenous fluid strategy did not seem to affect the time to resolution of hyperlactatemia in adult ICU patients with septic shock.

Clinical Relevance of Plasma Lactic Acid in the Onset and Prognosis of Sudden Deafness.

Sudden deafness poses a significant threat to patients' quality of life, yet effective indicators for evaluating its onset and prognosis remain elusive. The inner ear is primarily supplied by the labyrinthine artery, which lacks collateral circulation. Changes in coagulation function and hemorheology can cause spasm or thrombosis of the labyrinthine artery, leading to ischemia, hypoxia, and microcirculation disorders in the inner ear, ultimately resulting in sudden deafness. This retrospective study examined 196 patients with sudden deafness, utilizing the 2015 Chinese guideline for diagnosis and treatment classification. Coagulation system analysis used the STA-R Evolution automatic coagulation analyzer, measuring activated partial thromboplastin time (APTT), prothrombin time (PT), and fibrinogen (FIB). Plasma lactate concentration was determined using a Johnson and Johnson Fusion 5.1 model plasma lactate detector. Results of the study revealed a correlation between the degree of hearing loss and disease prognosis. Patients with higher grade hearing loss exhibited elevated plasma lactate levels upon admission compared with those with lower grade hearing loss. Importantly, elevated plasma lactate levels at admission served as predictive indicators for treatment outcomes. In addition, patients with ineffective treatment demonstrated a more coagulable blood state, as evidenced by the lower APTT (ineffective treatment: 31.47 ± 4.55 seconds, effective treatment: 35.17 ± 5.38 seconds) and PT on admission, but higher plasma FIB. In conclusion, plasma lactate levels upon admission hold promise as prognostic markers for sudden deafness treatment outcomes, providing valuable insights for clinical management.

Venous blood gas and lactate values in adult giraffe trained for voluntary jugular phlebotomy.

Blood gas analyses have previously been performed for giraffe under anesthesia and with physical restraint in a chute; however, reference values for giraffe that are trained to participate in venipuncture without chemical or physical restraint have not previously been described. Using a point-of-care blood gas and lactate analyzer and 20 giraffe trained for voluntary phlebotomy, values were determined for venous blood gasses and plasma lactate concentration. Ninety-five percent confidence in the mean values for venous pH (7.34-7.46), partial pressure of carbon dioxide (PCO2; 28.5-37.8 mmHg), partial pressure of oxygen (PO2; 56-102 mmHg), bicarbonate (HCO3 -; 18.9-21.0 mmol/L), base excess (BE; -6.0 to -3.6 mmol/L), total carbon dioxide (TCO2; 19.9-22.0 mmol/L), and lactate (0.32-0.56 mmol/L) were calculated. This is the first report on venous blood gas analysis values for giraffe without chemical or physical restraint. These data will provide a reference for clinical interpretation of venous blood gas and lactate values in giraffe and demonstrate some of the potential diagnostic benefits to training giraffe and other zoo species for voluntary medical procedures.

Beyond Rest: Exploring the Sleep-Exercise Connection

Introduction The bidirectional relationship between the effects of sleep and exercise is often underappreciated. We aim to explore the bidirectional relationship of sleep and exercise. We further discuss the prominence of poor sleep in both the athletic and general population and understand the underlying mechanisms of interdependencies between the two. The goal is to illuminate practical implications to improve both areas and optimize physical and mental health.Objectives-To explore the bidirectional relationship between sleep and exercise-To understand how exercise can counterbalance the adverse metabolic consequences of sleep deprivation. MethodsWe conducted a systemic literature review from Pubmed, Scopus, and PsychINFO using the search terms: “(exercise) and (sleep),” “(exercise performance) and (sleep),” “(sleep quality) and (exercise).” We included original studies in English conducted on age groups 18 years and older.Results Data from 31 studies shows that a significant number of athletes experience poor sleep quality and daytime sleepiness. 68.5% of Qatar Stars League soccer players and 61% of collegiate athletes in NCAA institutions report daytime fatigue several times a week. Most common causes include overtraining, hectic travel schedules, and sleeping in unfamiliar settings. Studies confirm athletes often sleep less before intense training or competitions. Sleep deficiency may lead to reduced muscular strength and endurance, mood changes, increased perceived effort, impaired cognitive processing, and diminished motor skills. Athletes averaging less than 8 hours of sleep nightly were 1.7 times more prone to injuries. Physiologically, sleep loss alters ventilation, plasma lactate concentration, hormone secretion, and inflammatory responses, hinders muscle glycogen restoration. Extended sleep restriction decreases testosterone levels, which influence muscle mass, energy, bone strength, and more. On the contrary, exercise may counter adverse metabolic impacts of sleep deprivation. High-intensity interval exercise (HIIE) has shown to nullify negative metabolic effects of sleep deprivation, suggesting exercise’s protective potential.Conclusions Sleep and exercise are fundamental to maintaining physical, mental, emotional, and spiritual health. The bidirectional, interdependent relationship can be best utilized by the providers to optimize overall well being. The critical impact of adequate sleep, particularly among athletes, is frequently underestimated. Poor sleep can detrimentally affect performance, amplify injury risks, and disrupt physiological functions, yet contemporary lifestyles often downplay its significance. It is important for healthcare professionals to emphasize a balanced approach to optimize these vital aspects. Continued research can offer strategies that benefit athletes and the broader populace, aiming to uplift daily life functionality.Disclosure of InterestNone Declared

Influence of High-Intensity Interval Training on Neuroplasticity Markers in Post-Stroke Patients: Systematic Review.

Background: Exercise has shown beneficial effects on neuronal neuroplasticity; therefore, we want to analyze the influence of high-intensity interval training (HIIT) on neuroplasticity markers in post-stroke patients. Methods: A systematic review of RCTs including studies with stroke participants was conducted using the following databases (PubMed, LILACS, ProQuest, PEDro, Web of Science). Searches lasted till (20/11/2023). Studies that used a HIIT protocol as the main treatment or as a coadjutant treatment whose outcomes were neural plasticity markers were used and compared with other exercise protocols, controls or other kinds of treatment. Studies that included other neurological illnesses, comorbidities that interfere with stroke or patients unable to complete a HIIT protocol were excluded. HIIT protocol, methods to assess intensity, neuroplasticity markers (plasmatic and neurophysiological) and other types of assessments such as cognitive scales were extracted to make a narrative synthesis. Jadad and PEDro scales were used to assess bias. Results: Eight articles were included, one included lacunar stroke (less than 3 weeks) and the rest had chronic stroke. The results found here indicate that HIIT facilitates neuronal recovery in response to an ischemic injury. This type of training increases the plasma concentrations of lactate, BDNF and VEGF, which are neurotrophic and growth factors involved in neuroplasticity. HIIT also positively regulates other neurophysiological measurements that are directly associated with a better outcome in motor learning tasks. Conclusions: We conclude that HIIT improves post-stroke recovery by increasing neuroplasticity markers. However, a limited number of studies have been found indicating that future studies are needed that assess this effect and include the analysis of the number of intervals and their duration in order to maximize this effect.

Enrichment of medium-quality colostrum by adding colostrum replacer, combined or not with transition milk in the feeding of dairy calves

Fifty Holstein calves were allocated in randomized blocks and distributed in a 2 × 2 factorial arrangement; (A) two sources of Ig: (1) Control: bovine colostrum (25% Brix); (2) Enriched colostrum: mid-quality bovine colostrum (20% Brix) enriched with colostrum replacer to 25% Brix; and (B) two transition feeding diets: (1) Whole milk (WM): supply of 4 L/day of whole milk for 3 days after the colostrum feeding; and (2) Formulated transition milk (FTM): supply 4 L/day of whole milk enriched with 70 g/L of colostrum replacer for 3 days after the colostrum feeding. Blood samples were collected at 0, 24, 48, and 72 h of age to determine total serum protein (TSP), glucose, non-esterified fatty acids (NEFA), erythrocyte and leukocyte concentrations. IgG was measured at 48 h. During the preweaning period, calves received 6 L/day of whole milk. Blood samples were collected weekly to determine TSP, glucose, and lactate. The colostrum protocols were equally efficient for transfer of passive immunity with IgG concentration at 48 h ≥ 49.6 g/L. Colostrum or transition feeding program did not influence the erythrocyte and leukocyte concentrations. The TSP concentration measured until 72 h was higher for calves fed maternal colostrum. Calves fed milk in the transition period had higher glucose concentrations. Calves receiving bovine colostrum and FTM had higher glucose concentrations in the preweaning period, while the enriched colostrum decreased plasma lactate concentrations. In summary, enrichment of mid-quality colostrum is an alternative in situations of a shortage of high-quality colostrum; however, feeding 4 L/day of FTM only for 3 days after colostrum feeding does not show additional benefits.

85 Evaluation of a Saccharomyces cerevisiae fermentation product on performance, plasma metabolites, rumen parameters, and fecal pathogen shedding in feedlot steers

Abstract The objective of the experiment was to evaluate a commercial Saccharomyces cerevisiae fermentation product (SCFP; NaturSafe, Dimond V, Cedar Rapids, IA) on performance, plasma metabolites, rumen parameters, and fecal pathogen shedding in feedlot steers. Crossbred steers (n = 61; 271 ± 48.1 kg) were sourced from 3 different research units at Oklahoma State University and assigned to 1 of 3 experimental treatments in a randomized complete block design. Steers were group housed in pens equipped with an automated individual feed intake system. Treatments consisted of a negative control (CON), CON with tylosin phosphate (TYL; 9.9 mg · kg-1 of diet DM), or CON with SCFP (1.63 g · kg-1 of diet DM). Body weight and feed efficiency did not differ among treatments (P ≥ 0.12). However, steers fed SCFP tended to have greater ADG from d 35 to 56 (P = 0.10). In addition, steers fed SCFP exhibited increased DMI from d 56 to 112 (P = 0.03), a tendency for increased DMI from d 112 to final (P = 0.07), and increased DMI overall (P = 0.05). There was no treatment × time interaction for pH, pH change, or lactate concentrations in rumen fluid (P ≥ 0.11), but all were impacted by time (P &amp;lt; 0.01). A treatment × time interaction (P &amp;lt; 0.01) was detected for fecal pH and fecal pH change, with the pH being greater in TYL fed steers on d 56 and in CON fed steers on the final day. Steers that consumed CON had a reduced fecal pH (P &amp;lt; 0.01) and steers consuming SCFP tended to have a reduced fecal pH (P = 0.08) from d 35 to 56 compared with TYL fed steers, while both CON and SCFP fed steers experienced an increase in fecal pH from d 56 to 112 (P &amp;lt; 0.01). A time effect was detected (P ≤ 0.04) for plasma glucose, lactate, urea nitrogen, and non-esterified fatty acid concentrations among treatment groups. A treatment × time interaction was observed (P &amp;lt; 0.02) for stx2 genes of Shiga toxin producing Escherichia coli (STEC) in individual fecal samples where SCFP and TYL fed steers tended to exhibit an increased concentration compared with CON fed steers on d 14, while on d 190 CON and SCFP fed steers exhibited an increased concentration compared with TYL fed steers. Overall, STEC, E. coli O157:H7, and Salmonella concentrations were all impacted by time (P &amp;lt; 0.001). This experiment suggests that SCFP could be utilized as a potential alternative to TYL in feedlot cattle without adversely affecting cattle performance. However, SCFP did not impact pathogen shedding. In addition, CON fed steers performed similarly to both SCFP and TYL fed steers.

Effect of a 14-Day Period of Heat Acclimation on Horses Using Heated Indoor Arenas in Preparation for Tokyo Olympic Games.

To optimise the performance and welfare of horses during equestrian competitions in hot climates, it is advised to acclimate them to the heat. The effects of training in a heated indoor arena were studied. Four Olympic horses (13.3 ± 2.2 years; three eventers, one para-dressage horse) were trained for 14 consecutive days in a heated indoor arena (32 ± 1 °C; 50-60% humidity) following their normal training schedule in preparation for the Tokyo Olympic games. Standardised exercise tests (SETs) were performed on Day 1 and Day 14, measuring heart rate (HR; bpm), plasma lactate concentration (LA; mmol/L), deep rectal temperature (Trec; °C), sweat loss (SL; L), and sweat composition (K+, Cl- and Na+ concentration). The data were analysed using linear mixed models. The Trec and HR were significantly decreased after acclimation (estimate: -0.106, 95% CI -0.134, -0.078; estimate: -4.067, 95% CI -7.535, -0.598, respectively). Furthermore, for all the horses, the time taken to reach their peak Trec and heat storage increased, while their LA concentrations decreased. The SL, Cl-, and Na+ concentrations decreased in three out of the four horses. Conclusions: Fourteen days of normal training in a heated indoor arena resulted in a reduction in cardiovascular and thermal strain. This is advantageous because it shows that elite sport horses can be acclimated while training as usual for a championship.