L-lactate Concentration Research Articles

Intestinal fatty acid-binding protein (I-FABP) as biomarker of ischemic damage in experimentally induced 12-h small bowel obstruction.

Laboratory tests have low diagnostic specificity for strangulated intestinal obstruction. The diagnostic potential of the intestinal fatty acid-binding protein (I-FABP) expressed in the tips of the intestinal villi continues to be explored. The number of white blood cells, blood plasma levels of L-lactate, C-reactive protein (CRP) and I-FABP were measured in rats with experimentally induced 12-h strangulated and non-strangulated intestinal obstruction. The results of the laboratory tests were compared with the changes in the morphology of the intestinal wall. The studied diagnostic markers, except for CRP, were elevated by 12-h L-lactate and I-FABP concentrations were significantly higher in the strangulated obstruction group than in other groups. L-lactate (cutoff value: 3.01mmol/L) had 86.1% sensitivity and 66.7% specificity for strangulated obstruction (AUC 0.815, p < 0.001). I-FABP levels above 5.432ng/ml indicated strangulated obstruction with 83.33% sensitivity and 88.9% specificity (AUC 0.906, p < 0.001). Villi destruction was observed at 2h in the strangulated obstruction group. I-FABP levels peaked at 4h and plateaued at 12h. Functional changes were observed in the non-strangulated group; they were accompanied by a significant increase in I-FABP concentrations that lasted until 12h. Compared with traditional diagnostic markers of strangulated intestinal obstruction, I-FABP demonstrated higher accuracy in the first 12h, although its concentrations reached the plateau already at 4h and did not increase thereafter. The functional changes in small bowel wall in non-strangulated obstruction were accompanied by continuous increase in I-FABP concentrations up to 12h, which may have influenced the diagnostic accuracy of the marker.

Determining lactate concentrations in Korean indigenous calves and evaluating its role as a predictor for acidemia in calf diarrhea

BackgroundCalf diarrhea leads to high mortality rates and decreases in growth and productivity, causing negative effects on the livestock industry. Lactate is closely associated with metabolic acidosis in diarrheic calves. However, there have been no reports on lactate concentrations in Korean indigenous (Hanwoo) calves, especially those with diarrhea. This study aimed to determine the reference range of L-lactate and D-lactate concentrations in Hanwoo calves and to better understand the utility of lactate as predictive factors for acidemia in diarrheic calves.ResultsL-lactate and D-lactate concentrations were measured in healthy (n = 44) and diarrheic (n = 93) calves, and blood gas analysis was performed on diarrheic calves. The reference range in healthy calves was 0.2–2.25 mmol/L for L-lactate and 0.42–1.38 mmol/L for D-lactate. Diarrheic calves had higher concentrations of L-lactate and D-lactate than healthy calves. In diarrheic calves, L-lactate and D-lactate each had weak negative correlation with pH (r = − 0.31 and r = − 0.35). In diarrheic calves with hyper-L-lactatemia, the combined concentrations of L-lactate and D-lactate had moderate correlation with pH (r = − 0.51) and anion gap (r = 0.55). Receiver operating characteristic analysis showed D-lactate had fair predictive performance (AUC = 0.74) for severe acidemia, with an optimal cut-off value of > 1.43 mmol/L. The combined concentrations of L-lactate and D-lactate showed fair predictive performance for predicting acidemia (AUC = 0.74) and severe acidemia (AUC = 0.72), with cut-off values of > 6.05 mmol/L and > 5.95 mmol/L.ConclusionsThe determined reference ranges for L-lactate and D-lactate in Hanwoo calves enable the identification of hyper-L-lactatemia and hyper-D-lactatemia. Diarrheic calves exhibited increased lactate concentrations correlated with acid-base parameters. While the concentrations of L-lactate and D-lactate have limitations as single diagnostic biomarkers for predicting acidemia or severe acidemia, their measurement remains important, and L-lactate has the advantage of being measurable at the point-of-care. Assessing lactate concentrations should be considered by clinicians, especially when used alongside other clinical indicators and diagnostic tests. This approach can improve calf diarrhea management, contributing positively to animal welfare and providing economic benefits to farms.

The effect of probiotic supplementation on sleep, depression-like behaviour, and central glucose and lactate metabolism in male and female pubertal mice exposed to chronic sleep disruption

The prevalence of depression significantly increases during puberty and adolescence. Puberty is the period during which sexual maturity is attained, while adolescence persists beyond puberty and includes physiological, social, emotional, and cognitive maturation. A stressor that has been shown previously to induce depression is chronic sleep disruption. Probiotics can prevent stress-induced depression. However, it was unclear whether probiotics could prevent depression following chronic sleep disruption and what mechanism may be involved. Therefore, we investigated whether pubertal probiotic treatment could prevent depression-like behavior in mice following chronic sleep disruption. We also examined whether probiotic treatment could improve sleep quality, and increase serotonin, tryptophan, glucose, and L-lactate concentrations in chronically sleep-disrupted mice. We hypothesized that probiotic treatment would prevent depression-like behavior, improve sleep quality, and increase serotonin, tryptophan, glucose, and L-lactate concentrations in sleep-disrupted mice. Male and female mice (N=120) received cannula and electroencephalogram (EEG) electrode implants at postnatal day (PND) 26. Mice received Lacidofil® or Cerebiome® probiotics (PND 33–51) and were sleep-disrupted for the first 4 hours of the light phase (sleep period) (PND 40–51). Hippocampal L-lactate and glucose concentrations and sleep were measured over a 24-h period (PND 48–49). Depression-like behaviour was evaluated using tail suspension (PND 49) and forced swim tests (PND 50). Chronic sleep disruption increased depression-like behaviour and NREM duration in the dark phase, and reduced all metabolites and neuromodulating biomolecules measured within the brain. However, mice treated with probiotics did not display depression-like behaviour or decreased hippocampal L-lactate following chronic sleep disruption. Cerebiome prevented decreases to prefrontal serotonin and hippocampal glucose concentrations, while Lacidofil increased NREM duration in the latter half of the light phase. The current study not only replicates previous findings linking chronic sleep disruption to depression, but also demonstrates that pubertal probiotic treatment can mitigate the effects of chronic sleep disruption on depression-like behaviour and on the neural mechanisms underlying depression in a strain-dependent manner.

Healthy and diabetic primary human osteoblasts exhibit varying phenotypic profiles in high and low glucose environments on 3D-printed titanium surfaces.

The revolution of orthopedic implant manufacturing is being driven by 3D printing of titanium implants for large bony defects such as those caused by diabetic Charcot arthropathy. Unlike traditional subtractive manufacturing of orthopedic implants, 3D printing fuses titanium powder layer-by-layer, creating a unique surface roughness that could potentially enhance osseointegration. However, the metabolic impairments caused by diabetes, including negative alterations of bone metabolism, can lead to nonunion and decreased osseointegration with traditionally manufactured orthopedic implants. This study aimed to characterize the response of both healthy and diabetic primary human osteoblasts cultured on a medical-grade 3D-printed titanium surface under high and low glucose conditions. Bone samples were obtained from six patients, three with Type 2 Diabetes Mellitus and three without. Primary osteoblasts were isolated and cultured on 3D-printed titanium discs in high (4.5 g/L D-glucose) and low glucose (1 g/L D-Glucose) media. Cellular morphology, matrix deposition, and mineralization were assessed using scanning electron microscopy and alizarin red staining. Alkaline phosphatase activity and L-lactate concentration was measured in vitro to assess functional osteoblastic activity and cellular metabolism. Osteogenic gene expression of BGLAP, COL1A1, and BMP7 was analyzed using reverse-transcription quantitative polymerase chain reaction. Diabetic osteoblasts were nonresponsive to variations in glucose levels compared to their healthy counterparts. Alkaline phosphatase activity, L-lactate production, mineral deposition, and osteogenic gene expression remained unchanged in diabetic osteoblasts under both glucose conditions. In contrast, healthy osteoblasts exhibited enhanced functional responsiveness in a high glucose environment and showed a significant increase in osteogenic gene expression of BGLAP, COL1A1, and BMP7 (p<.05). Our findings suggest that diabetic osteoblasts exhibit impaired responsiveness to variations in glucose concentrations, emphasizing potential osteoblast dysfunction in diabetes. This could have implications for post-surgery glucose management strategies in patients with diabetes. Despite the potential benefits of 3D printing for orthopedic implants, particularly for diabetic Charcot collapse, our results call for further research to optimize these interventions for improved patient outcomes.

Evaluation of peritoneal l-lactate concentration in horses in the early post-partum period.

Peritoneal fluid lactate concentration is an important diagnostic tool in horses with abdominal pain. Information on peritoneal lactate concentrations is lacking following parturition in the mare. To compare blood and peritoneal lactate concentrations in a population of mares within 36h post-partum, report a normal reference range and identify any impact of retained foetal membranes (RFMs). This is a retrospective study evaluating healthy mares from which blood and peritoneal samples had been obtained within 36h of parturition. Exclusion criteria included signs of abdominal pain within this period. Data was interrogated for normality using a Shapiro-Wilk test. Wilcoxon signed-rank test and Bland-Altman analysis were used to compare blood and peritoneal lactate concentrations. Linear regression was used to compare age and breed data with peritoneal lactate concentrations. Significance was defined as p<0.05. Forty mares met the inclusion criteria. Mean age was 12.6±4.1 years, and most mares were multiparous (65%). Peritoneal lactate ((1.2 (IQR=0.9-1.6)mmol/L) was increased compared to blood lactate concentration (0.7 (IQR=0-1.1)mmol/L; p<0.001). Plasma total protein (TP) concentrations were 68 (IQR=64-74)g/L and peritoneal protein concentrations 8 (IQR=4-9.7)g/L. Six mares developed RFM. The median fold-increase in peritoneal lactate concentration compared to blood lactate concentration was 0.9 (IQR: 0.01-1.7; range: 0-2.5). The reference range for peritoneal fluid lactate concentration was 0-2.5mmol/L. Peritoneal lactate concentrations in healthy post-partum mares remained within the normal reference range and were not influenced by RFM or parturition. Increased peritoneal lactate in this group warrants further investigation.

Semiconducting polymer dots based l-lactate sensor by enzymatic cascade reaction system

Backgroundl-lactate detection is important for not only assessing exercise intensity, optimizing training regimens, and identifying the lactate threshold in athletes, but also for diagnosing conditions like L-lactateosis, monitoring tissue hypoxia, and guiding critical care decisions. Moreover, l-lactate has been utilized as a biomarker to represent the state of human health. However, the sensitivity of the present l-lactate detection technique is inadequate. ResultsHere, we reported a sensitive ratiometric fluorescent probe for l-lactate detection based on platinum octaethylporphyrin (PtOEP) doped semiconducting polymer dots (Pdots-Pt) with enzymatic cascade reaction. With the help of an enzyme cascade reaction, the l-lactate was continuously oxidized to pyruvic and then reduced back to l-lactate for the next cycle. During this process, oxygen and NADH were continuously consumed, which increased the red fluorescence of Pdots-Pt that responded to the changes of oxygen concentration and decreased the blue fluorescence of NADH at the same time. By comparing the fluorescence intensities at these two different wavelengths, the concentration of l-lactate was accurately measured. With the optimal conditions, the probes showed two linear detection ranges from 0.5 nM to 5.0 μM and 5.0 μM–50.0 μM for l-lactate detection. The limit of detection was calculated to be 0.18 nM by 3σ/slope method. Finally, the method shows good detection performance of l-lactate in both bovine serum and artificial serum samples, indicating its potential usage for the selective analysis of l-lactate for health monitoring and disease diagnosis. SignificanceThe successful application of the sensing system in the complex biological sample (bovine serum and artificial serum samples) demonstrated that this method could be used for sensitive l-lactate detection in practical clinical applications. This detection system provided an extremely low detection limit, which was several orders of magnitude lower than methods proposed in other literatures.

Effects of Adenosine and Lactate Coexistence on NK92 Cell

Aims: This study aims to investigate the impact of lactate and adenosine, present in the tumor microenvironment (TME), on the immune cell immunity.&#x0D; Methodology: Five groups included Adenosine concentration screening groups, L-lactic acid and Sodium L-lactate concentration groups, Adenosine + L-lactic acid and Adenosine + sodium L-lactate concentration groups were chosen to evaluate the NK92 cell functions. The proliferation ability and morphological observations of NK92 cells were assessed using a hemocytometer. The CCK-8 assay measured the inhibition of NK92 cell activity in the treatment group, while the crystal violet method evaluated the effect of NK92 cells on the killing ability of A549 cells.&#x0D; Results: A concentration of 50 μM adenosine served as a reference for high adenosine experimental concentrations, demonstrating a significant impact on NK92 immune cells within the TME. The functional entity "lactic acid" revealed independent effects of lactate [La-] and hydrogen ions [H+]. Lactate enhanced cell viability but reduced NK92 cytotoxicity. Conversely, lactic acid containing hydrogen ions caused a sharp decrease in cell viability and cytotoxicity to tumor cells.&#x0D; Conclusion: Elevated adenosine concentration and acidification of the tumor microenvironment significantly inhibit the ability of NK cells to kill tumor cells.

Solução intravenosa poliiônica com concentração elevada de lactato (84 mEq/L) é eficaz para o tratamento de bezerros com diarreia

ABSTRACT This study aimed to evaluate the effectiveness of an electrolyte solution with a high lactate concentration (84mEq/L; L84) in correcting imbalances in diarrheal calves. Another solution with similar electrolyte composition, containing 84mEq/L of bicarbonate (B84) was used for comparison. Diarrhea was induced in neonatal calves by rotavirus infection, sucrose ingestion and furosemide administration. When a moderate degree of metabolic acidosis was reached, the calves were treated with intravenous infusion of L84 (n=10) or B84 (n=10) solutions. Venous blood and urine samples were collected before starting the infusion (0 h), in the middle (2.5 h), at the end (5.0 h) and 2.5 hours later. Total plasma protein concentration, blood and urine pH, blood pCO2, HCO3 -, and BE, plasma and urine concentration of L-lactate, and serum and urine concentrations of Na+, K+, and Cl- were measured. Strong ion difference, total concentration of non-volatile weak acids, anion gap, strong ion gap, percentage change in plasma volume, and urinary fractional clearances of Na+, K+, Cl-, and L-lactate were calculated. The calves demonstrated moderate dehydration, hypernatremia, hyperchloremia, metabolic acidosis, and unmeasured anion accumulation. These changes were completely corrected with the L84 solution, and the effects did not differ from those observed with B84 solution. The calves recovered without further therapeutic procedures, demonstrating that the L84 solution was effective for treating diarrheal calves.

Sodium alginate hydrogelation mediated paper-based POCT sensor for visual distance reading and smartphone-assisted colorimetric dual-signal determination of L-lactate.

Herein, we present a paper-based POCT sensor based on lactate dehydrogenase-mediated alginate gelation combined with visual distance reading and smartphone-assisted colorimetric dual-signal analysis to determine the concentration of L-lactate in yogurt samples. In this research, L-lactate was transformed into pyruvate by lactate dehydrogenase. Pyruvate then triggered the gelation of a sol mixture, increasing the viscosity (ηs) of the mixture, which was shown as a decrease in the diffusion diameter on the paper-based sensor. In addition, protons from pyruvate accelerated the degradation of Rhodamine B, causing color fading of the mixture, which was analyzed using RGB analysis application software. Under optimal experimental conditions, the linear ranges of visual distance reading and smartphone-assisted colorimetric analysis were 0.1-15 μM and 0.3-15 μM and the detection limits were 0.03 μM and 0.07 μM, respectively. As a proof-of-concept application, we exploited the paper-based sensor to determine the concentration of L-lactate in yogurt samples. The results from the dual-signal paper-based sensor were consistent with the ones from HPLC analysis. In short, this study developed a simple, convenient, cost-effective, and feasible method for the quantitative detection of L-lactate in real samples.

In vitro evaluation of microbial D- and L-lactate production as biomarkers of infection.

Mammalian cells produce and metabolize almost exclusively L-lactate, bacterial species have the capacity to produce both D-lactate and L-lactate. The aim of this study was to evaluate the intrinsic production of D- and L-lactate in the most common pathogenic microorganisms causing septic arthritis (SA) and periprosthetic joint infection (PJI) as a potential biomarker for the diagnosis of infection. Following microorganisms were grown according to ATCC culture guides and tested for production of D- and L-lactate: Staphylococcus aureus (ATCC 43300), Staphylococcus epidermidis (ATCC 35984), Enterococcus faecalis (ATCC 19433), Streptococcus pyogenes (ATCC 19615), Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), Cutibacterium acnes (ATCC 11827), and Candida albicans (ATCC 90028). Pathogens were inoculated in 8 ml of appropriate liquid media and incubated as planktonic or biofilm form in either aerobic, anaerobic or CO2 atmosphere up to 312 h. D- and L-lactate measurements were performed at different time points: 0, 6, 9, 12 and 24 h, then once per day for slow-growing pathogens. Samples were serially diluted and plated for colony counting. Liquid culture media without microorganisms served as a negative control. Production of D-lactate was observed in all tested microorganisms, whereas no L-lactate was detected in E. coli, P. aeruginosa, and C. albicans. Maximal concentration of D-lactate was produced by S. aureus (10.99 mmol/L), followed by E. coli (1.22 mmol/L), and S. epidermidis (0.48 mmol/L). Maximal L-lactate concentration was observed in S. pyogenes (10.12 mmol/L), followed by S. aureus (9.71 mmol/L), E. faecalis (2.64 mmol/L), and S. epidermidis (2.50 mmol/L). S. epidermidis bacterial biofilm produced significantly higher amount of D- and L-lactate compared to planktonic form (p = 0.015 and p = 0.002, respectively). Our study has demonstrated that the most common pathogenic microorganisms causing SA and PJI have the capability to generate measurable amounts of D-lactate in both planktonic and biofilm form, highlighting the practical value of this biomarker as an indicator for bacterial and fungal infections. In contrast to D-lactate, the absence of L-lactate production in certain tested bacteria, as well as in fungi, suggests that L-lactate is not eligible as a biomarker for diagnosing microbial infections.

Survival rates and factors associated with survival and laminitis of horses with acute diarrhoea admitted to referral institutions.

Clinicopathological findings and their association with the outcome and development of laminitis in horses with acute diarrhoea has not been investigated in a multicentre study across different geographic regions. Describe and compare clinicopathologic findings of diarrhoeic horses between different geographic regions, survival rates and factors associated with non-survival and laminitis. Multicentre retrospective case series. Information from horses with acute diarrhoea presenting to participating institutions between 2016 and 2020 was collected, and clinicopathological data were compared between surviving and non-surviving horses and horses that did and did not develop laminitis. Survival rates and seasonal and geographic differences were also investigated. One thousand four hundred thirty-eight horses from 26 participating institutions from 4 continents were included; 76% survived to discharge with no differences identified between geographic regions. The survival proportion of horses with SIRS and creatinine concentrations > 159 μmol/L was 55% (154/279) compared with 81% (358/437) for those with SIRS and creatinine concentrations < 159 μmol/L (p < 0.001). The survival proportion of horses with SIRS that had an L-lactate concentration > 2.8 mmol/L was 59% (175/298) compared with 81% (240/296) in horses with SIRS and L-lactate concentration < 2.8 mmol/L (p < 0.001). The proportion of horses that developed laminitis was lower in Europe (4%, 19/479) compared with North America (8%, 52/619), Australia (8%, 12/138) and Latin America (11%, 16/146) (p < 0.05). More horses developed laminitis in the summer (46%, 39/85) compared with winter (18%, 15/85), spring (18%, 15/85) and fall (19%, 16/85) (p < 0.01). Horses with laminitis had greater odds of non-survival than those without laminitis (OR: 3.73, 95% CI: 2.47-5.65). Not all variables were available for all horses due to the retrospective nature. Clinicopathological findings in horses with acute diarrhoea and their association with survival are similar across geographic regions. However, developing laminitis secondary to diarrhoea is less common in Europe. In addition, factors associated with non-survival were indicative of disease severity and subsequent cardiovascular compromise.

Preoperative and Surgical Predictors of the Treatment Outcome of Dairy Cows with Right Abomasal Displacement-A Retrospective Study of 234 Cases.

The displacement of the abomasum to the right (RDA) is a common condition regularly encountered in dairy cows, which requires urgent surgical correction. The survival of the patient primarily depends on early diagnosis and timely treatment, but other factors contributing to the outcome have been discussed in the literature. The objective of this study was to identify preoperative clinical, hematological, as well as intraoperative parameters that are associated with the prognosis of cows with RDA or abomasal volvulus (AV). This retrospective study included patients admitted to a veterinary teaching hospital over a period of 6 years with a diagnosis of RDA or AV. A total of 234 cows were included, of which 193 were discharged after treatment and thus classified as survivors. In contrast, 41 cases died or were euthanized during or after surgery and were categorized as non-survivors. Non-survivors showed more severe dehydration, higher heart rate, lower sodium, as well as higher L-lactate and phosphorus concentration in their blood prior to surgery compared with the survivors. During surgery, the abomasum of non-survivors was markedly dilated and twisted more frequently than in survivors. The results presented here can facilitate the early identification of animals with poor prognosis requiring more intensive peri- and postoperative care.

Informative value of blood l-lactate and integral leukocyte indices for predicting severe course of mycoplasmosis in calves

The aim was to study the informativity of blood L-lactate and integral leukocyte indices for predicting a severe course of mycoplasmosis in calves during their natural infection with M. bovis. Daily clinical observation of 36 Holstein calves naturally infected with M. bovis (at the age of 10-15 days) was carried out for one month on the farms of the Ural Federal District. In blood samples obtained from the jugular vein of animals at the first signs of the disease, the levels of hemoglobin, erythrocytes, leukocytes, platelets, hematocrit on Abacus Junior Vet analyzer (Diatron, Austria), L-lactate concentration - by reaction with paraoxydiphenyl on UV-1800 spectrophotometer (Shimadzu, Japan) were studied. Differential leukocyte counts in Romanowsky- Giemsa stained blood smears were performed using Olympus BX43 microscope (Olympus, Japan). The following integral leukocyte indices were calculated: Krebs index (KI), leukocyte index of intoxication by Y. J. Calf- Calif (LII), neutrophil reactive response by T. Sh. Khabirov (NRR), adaptation index (AI), Bredeck index (IB), nuclear shift index (NSI), lymphocyte- granulocyte index (ILG), neutrophil to monocyte ratio index (NMR), leukocyte shift index (LSI), lymphocyte to monocyte ratio index (LMR) and lymphocyte to neutrophil ratio (LNR). In 22 (61,1 %) calves a mild to moderately severe course was detected, in 14 (38,9 %) - a severe course of mycoplasmosis. The animals predisposed to a severe course of mycoplasmosis had higher blood L-lactate &gt; 1.68 mmol/l, AI &gt; 1.57 units, ILG &gt; 16.7 units, LNR &gt; 1.41 units, reduced KI &lt; 0.645 units and LSI &lt; 0.600 units at the first clinical signs of disease. The information value of predictors for prognosing severe mycoplasmosis in calves was evaluated as very good; the sensitivity was 71.4-85.7 %, the specificity made 81.8-90.9 %. The accumulation of L-lactate in the blood of animals and changes in leukocyte indices (AI, ILG, LNR, KI, LSI) were shown to be interrelated.

Use of multiple admission variables better predicts intestinal strangulation in horses with colic than peritoneal or the ratio of peritoneal:blood l-lactate concentration.

Early identification of strangulating obstruction (SO) in horses with colic improves outcomes, yet early diagnosis of horses requiring surgery for SO often remains challenging. To compare blood and peritoneal fluid l-lactate concentrations, peritoneal:blood l-lactate ratio, peritoneal minus blood (peritoneal-blood) l-lactate concentration and other clinical variables for predicting SO and SO in horses with small intestinal lesions (SO-SI) and then to develop a multivariable model to predict SO and SO-SI. Retrospective cohort. A total of 197 equids admitted to a referral institution for colic between 2016 and 2019 that had peritoneal fluid analysis performed at admission were included. Twenty-three admission variables were evaluated individually for the prediction of a SO or SO-SI and then using multivariable logistic regression. Odds ratios (ORs) with 95% confidence intervals (CI) and area under the curve of the receiver operator characteristic (AUC ROC) were calculated. All variables performed better in the model than individually. The final multivariable model for predicting SO included marked abdominal pain (OR 5.31, CI 1.40-20.18), rectal temperature (OR 0.30, CI 0.14-0.64), serosanguineous peritoneal fluid (OR 35.34, CI 10.10-122.94), peritoneal-blood l-lactate (OR 1.77, CI 1.25-2.51), and peritoneal:blood l-lactate ratio (OR 0.36, CI 0.18-0.72). The AUC ROC was 0.91. The final multivariable model for predicting SO-SI included reflux volume (OR 0.69, CI 0.56-0.86), blood l-lactate concentration (OR 0.43, CI 0.22-0.87), serosanguineous peritoneal fluid (OR 4.99, CI 1.26-19.74), and peritoneal l-lactate concentration (OR 3.77, CI 1.82-7.81). Retrospective, single-hospital study design. Blood and peritoneal fluid l-lactate concentrations should be interpreted in conjunction with other clinical variables. The relationship between peritoneal and blood l-lactate concentration for predicting SO or SO-SI was complex when included in a multivariable model. Models to predict SO probably vary based on lesion location.

Dietary Chitosan Supplementation Modulates Hematology, Lipid Profile, Rumen Function, Antioxidant Status, and Thyroxin in Zaraibi Goat Bucks Fed on High-Fat Diets

Recently, chitosan gained a great attention due to its unique biological activities as a natural biodegradable polymer derived from chitin with non-antigenic, non-toxic. It has several positive impacts on animal health including potent antioxidant, antimicrobial activities, and anti-immunogenicity. Therefore, it is a natural, bioactive, mucoadhesive, and biocompatible compound used commonly as a safe additive in animal production. This study was conducted to detect the effects of dietary inclusion of chitosan in high-fat diet (HFD) on growth, hematology, lipid profile, rumen function, oxidative stress, and antioxidant status of Zaraibi goat bucks. Total of 18 sexually mature bucks (38.69±0.57 kg BW) were allocated into 3 groups (n= 6); the control group fed the control diet and treatment groups received HFD (the control diet with 3% fat) and the HFD plus 2.5% chitosan for 8 weeks, respectively. Results showed that HFD increase (P<0.05) final body weight, total weight gain, white blood cells (WBCs), and serum total cholesterol (TC), triglycerides (TG), VLDL, LDL, and malondialdehyde (MDA) with declined free T4 hormone, and HDL with the exhaustion of GSH, CAT and GPx activities beside reducing ruminal total proteins, glucose, ammonia-N, TVFA, total and L-lactate concentrations. Chitosan dietary inclusion to HFD reversed the aforementioned parameters with a notable enhancement of the antioxidant enzyme activities, suppressed the elevated MDA levels, and restored the depleted T4 level. Therefore, chitosan could be safely utilized as a dietary supplement in buck's diets to improve organ functions, lipid profile, antioxidant defense system, scavenge free radicals, and potentiate Buck's reproductive activities.

Acid-base imbalances and the association of blood-gas variables, electrolytes, and biochemical analytes with outcome in hospitalized calves undergoing abdominal surgery.

Surgical abdominal emergencies in calves are associated with a guarded prognosis and have the potential for complex metabolic derangements including acid-base imbalances. To perform a comprehensive analysis of acid-base status and to assess the prognostic relevance of preoperative clinicopathologic variables in calves undergoing abdominal surgery. Hospital-based study samples of 535 (dataset 1; DS1) and 83 calves (dataset 2; DS2). Retrospective (DS1) and prospective (DS2) case series. In DS1, acidemia (pH <7.33) was present in 49.9%, whereas alkalemia (pH >7.37) was present in 30.7% of calves. Plasma L-lactate, chloride, and serum inorganic phosphorus concentration accounted for 51.9%, 11.6% and 9.4% of the variation of venous blood pH, respectively. Classification tree analysis indicated that a negative outcome (death or euthanasia during hospitalization) was associated with venous pO2 ≤33.6 mm Hg, anion gap >18.3 and >22.9mEq/L, serum albumin concentration ≤36.5 and ≤29.4g/L, serum urea concentration >4.4 mmol/L, and plasma ionized calcium concentration ≤1.26 mmol/L. The area under the receiver operating characteristic curve of this model was 0.85 (95% CI: 0.82-0.89, P < .001) and the resulting sensitivity and specificity for the prediction of nonsurvival at the optimal probability cut-point of 0.5 was 89.8% and 65.7%, respectively. In DS2 the model had a similar sensitivity and specificity of 90.5% and 70%, respectively. Clinicopathologic imbalances and associated changes of acid-base status are common in calves with surgical abdominal emergencies and have clinical utility for the prediction of a negative postoperative outcome.

An enhanced L-lactate biosensor based on nanohybrid of chitosan, iron-nanoparticles and carboxylated multiwalled carbon nanotubes

An enhanced biosensor was developed for the determination of blood lactate in lacto-acidosis patients. The biosensor employed a nanohybrid composed of chitosan/iron oxide nanoparticles and carboxylated multiwalled carbon nanotubes (CHIT/Fe3O4NPs/c-MWCNTs), electrodeposited onto an Au electrode, followed by covalent immobilization of L-lactate oxidase (LOx) onto this nano-hybrid. The biosensor (LOx/CHIT/Fe3O4NPs/c-MWCNTs/AuE) exhibited notable improvements in its analytical characteristics such as a rapid response time (4s), a lower detection limit of 0.15 μM and a wider linear range of 1–3000 μM of L-lactic acid. Additionally, it displayed enhanced reproducibility and an extended shelf life of 100 days. The biosensor was employed to measure the concentration of L-lactate in the plasma of both apparently healthy individuals and lacto-acidosis patients. The results showed that the L-lactate concentrations ranged from 112 ± 1.24 to 183 ± 29.15 μmol/L in apparently healthy individuals, whereas it ranged from 2236 ± 33.29 to 4949 ± 72.39 μmol/L in lacto-acidosis patients, which is significantly higher than in apparently healthy individuals. Thus, the integration of the CHIT/Fe3O4NPs/c-MWCNTs hybrid film in the biosensor led to the enhanced analytical performance of the biosensor.

Astrocyte L-Lactate Signaling in the ACC Regulates Visceral Pain Aversive Memory in Rats.

Pain involves both sensory and affective elements. An aspect of the affective dimension of pain is its sustained unpleasantness, characterized by emotional feelings. Pain results from interactions between memory, attentional, and affective brain circuitry, and it has attracted enormous interest in pain research. However, the brain targets and signaling mechanism involved in pain remain elusive. Using a conditioned place avoidance (CPA) paradigm, we show that colorectal distention (CRD magnitude ≤ 35 mmHg, a subthreshold for pain) paired with a distinct environment can cause significant aversion to a location associated with pain-related insults in rats. We show a substantial increase in the L-lactate concentration in the anterior cingulate cortex (ACC) following CPA training. Local exogenous infusion of lactate into the ACC enhances aversive memory and induces the expression of the memory-related plasticity genes pCREB, CREB, and Erk1/2. The pharmacological experiments revealed that the glycogen phosphorylation inhibitor 1,4-dideoxy-1,4-imino-D-arabinitol (DAB) impairs memory consolidation. Furthermore, short-term Gi pathway activation of ACC astrocytes before CPA training significantly decreases the lactate level and suppresses pain-related aversive learning. The effects were reversed by the local infusion of lactate into the ACC. Our study demonstrates that lactate is released from astrocytes in vivo following visceral pain-related aversive learning and memory retrieval and induces the expression of the plasticity-related immediate early genes CREB, pCREB, and Erk1/2 in the ACC. Chronic visceral pain is an important factor in the pathophysiology of irritable bowel syndrome (IBS). The current study provides evidence that astrocytic activity in the ACC is required for visceral pain-related aversive learning and memory.

Effect of rest, post-rest transport duration, and conditioning on performance, behavioural, and physiological welfare indicators of beef calves.

The aim of this study was to assess the effects of conditioning, rest, and post-rest transport duration on welfare indicators of 6-7 mo old beef calves following a 20-h transport. Three hundred and twenty-eight weaned calves (237 ± 29.7 kg of BW) were randomly assigned to a 2 × 2 × 2 nested factorial design: conditioning, conditioned (C) or non-conditioned (N); rest, 0 (R0) or 8 (R8) h, and post-rest transport, 4 (T4) or 15 (T15) h. Calves were sampled before (LO1) and after (UN1) the initial 20-h journey, before (LO2) and after (UN2) the additional 4 or 15-h journey, and at 1, 2, 3, 5, 14, and 28 d after UN2. Data was analyzed using the GLIMMIX procedure of SAS. Fixed effects included conditioning, transport, and time nested within rest period, while random effects included animal and pen. Greater shrink (p < 0.01) was observed in C than N calves after the initial 20-h transport. During the first week after transportation, the mean ADG of N calves was greater than C calves (p < 0.01). From d 14 to d 28, however, the mean ADG of C calves was greater than N calves (p < 0.01). Flight speed, cortisol and L-lactate concentrations were greater (p ≤ 0.05) in C than N calves between LO1 and d 5, while greater (p ≤ 0.02) non-esterified fatty acids, creatine kinase, serum amyloid-A, and haptoglobin concentrations were observed in N than C calves between LO1 and d 3. The R8-T4 calves had greater (p < 0.01) ADG than R8-T15 calves between LO1 and d 5. The R0-T4 calves had greater L-lactate concentrations than R0-T15 and R8-T4 calves (both p = 0.02) on d 1. The R0 calves had greater (p < 0.01) ADG than R8 calves between 14 and 28 d. This study suggests that C calves are better fit for transport than N calves as evidenced by behavioural and physiological parameters. Fewer and inconsistent differences were observed for rest and post-rest transport treatments.

Effects of a Specific Pre- and Probiotic Combination and Parent Stock Vaccination on Performance and Bacterial Communities in Broilers Challenged with a Multidrug-Resistant Escherichia coli.

Antibiotic resistance poses a risk for human and animal health, leading to a growing demand for effective alternatives. Combining nutritional tools and parent stock vaccination could be an approach to achieve sufficient protection against bacterial infections in poultry. In an Escherichia coli O1/O18 challenge trial, we investigated the protective effects of feeding diets containing Enterococcus faecium DSM 7134 and fructooligosaccharides (FOS) combined with specific parent stock vaccination in 225 ROSS 308 broilers. Data on performance parameters, intestinal microbial composition and metabolites, and antibiotic resistance genes (sul1-3, dhfr1a, SHV-12) were obtained. E. faecium and FOS combined with parent stock vaccination led to the highest body weights, which were significantly higher than those of controls throughout the experiment and decreased the relative abundance of Proteobacteria in the crop digesta compared to that in the positive control. However, cumulative feed conversation remained unaffected by the strategies. Birds receiving the pre-/probiotic combination showed lower cecal pH levels and higher crop L-lactate concentrations than the controls, whereas copy numbers of dhfr1a (trimethoprim resistance) and SHV-12 (extended-spectrum beta-lactamase) genes were only decreased in broilers from vaccinated hens compared to those in the challenged control. In conclusion, prophylactic administration of E. faecium and FOS in combination with parent stock vaccination can have complementary effects by improving broiler weight gain and stimulating intestinal bacterial metabolism, which may be beneficial for maintaining gut health in terms of Escherichia coli infection.