Development and validation of a machine-learning model for predicting the risk of death in sepsis patients with acute kidney injury.

The mortality rate of patients with sepsis-induced acute kidney injury (S-AKI) is notably elevated. The initial categorization of prognostic indicators has a beneficial impact on elucidating and enhancing disease outcomes. This study aimed to predict the mortality risk of S-AKI patients by employing machine learning techniques. The sample size determined by a four-step procedure yielded 1508 samples. The research design necessitated the inclusion of individuals with S-AKI from the Medical Information Mart for Intensive Care (MIMIC)-IV database. The patients were initially admitted to the Intensive Care Unit (ICU) for their hospital stay. Additionally, these patients (aged from 18 to 89 years old) had encountered S-AKI on the day of their admittance. Forty-two predictive factors were analyzed, with hospitalization death as the outcome variable. The training set (4001 cases) consisted of 70 % of the participants, and the remaining (1714 cases) participants were allocated to the validation set. Furthermore, an additional validation set (MIMIC-III) consisted of 1757 patients from the MIMIC-III database. Moreover, an external validation set from the Intensive Care Department of Beijing Friendship Hospital (BFH) comprised 72 patients. Six machine learning models were employed in the prediction, namely the logistic, lasso, rpart, random forest, xgboost, and artificial neural network models. The comparative efficacy of the newly developed model in relation to the APACHE II model for predicting mortality risk was also assessed. The XGBoost model exhibited a superior performance with the training set. With the internal validation set and the two external validation sets (MIMIC-III and BFH), the xgboost algorithm demonstrated the highest performance. Meanwhile, APACHE II performed poorly at predicting the mortality risk with the BFH validation set. The mortality risk was influenced by three primary clinical parameters: urine volume, lactate, and Glasgow Coma Scale (GCS) score. Thus, we developed a prediction model for the risk of death among S-AKI patients that has an improved performance compared to previous models and is a potentially valuable tool for S-AKI prediction and treatment in the clinic.

Development and validation a nomogram prediction model for early diagnosis of bloodstream infections in the intensive care unit.

Purpose: This study aims to develop and validate a nomogram for predicting the risk of bloodstream infections (BSI) in critically ill patients based on their admission status to the Intensive Care Unit (ICU). Patients and methods: Patients' data were extracted from the Medical Information Mart for Intensive Care-IV (MIMIC-IV) database (training set), the Beijing Friendship Hospital (BFH) database (validation set) and the eICU Collaborative Research Database (eICU-CRD) (validation set). Univariate logistic regression analyses were used to analyze the influencing factors, and lasso regression was used to select the predictive factors. Model performance was assessed using area under receiver operating characteristic curve (AUROC) and Presented as a Nomogram. Various aspects of the established predictive nomogram were evaluated, including discrimination, calibration, and clinical utility. Results: The model dataset consisted of 14930 patients (1444 BSI patients) from the MIMIC-IV database, divided into the training and internal validation datasets in a 7:3 ratio. The eICU dataset included 2100 patients (100 with BSI) as the eICU validation dataset, and the BFH dataset included 419 patients (21 with BSI) as the BFH validation dataset. The nomogram was constructed based on Glasgow Coma Scale (GCS), sepsis related organ failure assessment (SOFA) score, temperature, heart rate, respiratory rate, white blood cell (WBC), red width of distribution (RDW), renal replacement therapy and presence of liver disease on their admission status to the ICU. The AUROCs were 0.83 (CI 95%:0.81-0.84) in the training dataset, 0.88 (CI 95%:0.88-0.96) in the BFH validation dataset, and 0.75 (95%CI 0.70-0.79) in the eICU validation dataset. The clinical effect curve and decision curve showed that most areas of the decision curve of this model were greater than 0, indicating that this model has a certain clinical effectiveness. Conclusion: The nomogram developed in this study provides a valuable tool for clinicians and nurses to assess individual risk, enabling them to identify patients at a high risk of bloodstream infections in the ICU.

Taurine alleviates heat stress-induced mammary inflammation and impairment of mammary epithelial integrity via the ERK1/2-MLCK signaling pathway.

Heat stress leads to milk production losses and mammary gland inflammation, which may be associated with mammary epithelium damage. Taurine is one of the most abundant free amino acids in mammals which has anti-inflammatory properties. This study aimed to explore the effect of taurine pretreatment on heat stress-induced mammary epithelial integrity disruption and inflammatory damage. In our first experiment on dairy cows our results showed that compared with animals under autumn thermoneutral condition (THI = 62.99 ± 0.71), summer heat stress (THI = 78.01 ± 0.39) significantly reduced milk yield and disrupted mammary epithelial integrity as revealed by increased concentrations of serotonin and lactose in plasma, and increased levels of SA and Na+/K+ in milk. In our second study, 36 lactating mice were randomly divided into three groups (n = 12) for a 9d experiment using a climate chamber to establish a heat stress model. Our findings suggest taurine pretreatment could attenuate heat stress-induced mammary histopathological impairment, inflammation response, and enhance mammary epithelium integrity, which was mainly achieved by promoting the secretion of ZO-1, Occludin, and Claudin-3 through inhibiting activation of the ERK1/2-MLCK signaling pathway in the mammary gland. Overall, our findings indicated that heat stress induced mammary epithelium dysfunction in dairy cows, and emphasized the protective effect of taurine on mammary health under heat stress conditions using a mouse model, which may be achieved by alleviating the mammary epithelium integrity damage and inflammation response.

Nomogram Prediction Model of Hypernatremia on Mortality in Critically Ill Patients.

Objective: To investigate the value of hypernatremia in the intensive care unit (ICU) for the risk prediction of mortality in severe patients. Methods: Clinical data of critically ill patients admitted to the ICU of Beijing Friendship Hospital, were collected for retrospective analysis. Univariate and multivariate logistic regression analyses were employed to analyze the influencing factors. Nomograms predicting the mortality were constructed with R software and validated with repeated sampling. Results: A total of 442 cases were eligible for this study. Hypernatremia within 48 hours of ICU admission, change in sodium concentration (CNa+) within 48 hours, septic shock, APACHE II score, hyperlactatemia within 48 hours, use of continuous renal replacement therapy (CRRT) within 48 hours, and the use of mechanical ventilation (MV) within 48 hours of ICU admission were all identified as independent risk factors for death within 28 days of ICU admission. These predictors were included in a nomogram of 28-day mortality in severe patients, which was constructed using R software. Conclusion: The nomogram could predict the individualized risk of 28-day mortality based on the above factors. The model has better discrimination and accuracy and has high clinical application value.

A protein- and fiber-rich diet with astaxanthin alleviates high-fat diet-induced obesity in beagles.

Background and aims: Overweight or obesity is one of the most prevalent health burdens in companion pets and predisposes subjects to multiple comorbidities and reduced longevity. Dietary management and sufficient exercise are effective options for weight loss but challenged by modern lifestyle and calorie control-triggered malnutrition. Therefore, this study aimed to develop a formulated obesity control diet characterized by protein- and fiber-rich diet and supplemented with astaxanthin. We systemically evaluated global influences of the designed weight-loss diet on metabolic homeostasis in an obese beagle model. Materials and methods: Beagles were induced for obesity by a 24-week HFD treatment and then included into weight-loss programs. Briefly, obese beagles were randomly assigned to two groups that were fed with a formulated weight-loss diet or control diet, respectively. Body weight and body condition scoring (BCS) were analyzed biweekly. Computed tomography (CT), nuclear magnetic resonance imaging (MRI) measurements, and blood and adipose tissue biopsies were collected at 0 and 8 weeks. Plasma lipids and adipocyte size were also measured after 8 weeks of weight-loss diet feeding. The global influence of the formulated diet on the whole spectrum of gene panels were examined by adipose RNA assays. Results: Twenty-four weeks of continuous HFD feeding significantly induced obesity in beagles, as evidenced by increased body weight, BCS, abdominal fat mass, and serum lipid levels. The obese and metabolic condition of the modeled canine were effectively improved by an 8-week weight-loss diet administration. Importantly, we did not observe any side effects during the weight loss duration. Transcriptional analysis of adipose tissues further supported that a weight-loss diet significantly increased energy metabolism-related pathways and decreased lipid synthesis-related pathways. Conclusion: The prescribed weight-loss diet exhibited profound benefits in canine weight management with well safety and palatability. These findings support effective strategies of nutritional management and supplementation approaches for weight control in companion animals.

Nomogram Prediction Model of Serum Chloride and Sodium Ions on the Risk of Acute Kidney Injury in Critically Ill Patients.

Purpose: This study aims to investigate the effect of serum chloride and sodium ions on AKI occurrence in ICU patients, and further constructs a prediction model containing these factors to explore the predictive value of these ions in AKI. Methods: The clinical information of patients admitted to ICU of Beijing Friendship Hospital Affiliated to Capital Medical University was collected for retrospective analysis. Logistic regression analysis was used to analyzing the influencing factors. A nomogram for predicting AKI risk was constructed with R software and validated by repeated sampling. Afterwards, the effectiveness and accuracy of the model were tested and evaluated. Results: A total of 446 cases met the requirements of this study, of which 178 developed AKI during their stay in ICU, with an incidence rate of 39.9%. Hypernatremia, heart failure, sepsis, APACHE II score, and initial creatinine value and BE value at ICU admission before the diagnosis of AKI were identified as independent risk factors for developing AKI during ICU stay. These predictors were incorporated into the nomogram of AKI risk in critically ill patients, which was constructed by using R software. Receiver operating characteristic curve analysis was further used and showed that the area under the curve of the model was 0.7934 (95% CI 0.742-0.8447), indicating that the model had an ideal value. Finally, further evaluated its clinical effectiveness. The clinical effect curve and decision curve showed that most areas of the decision curve of this model were greater than 0, indicating that this model owned a certain clinical effectiveness. Conclusion: The nomogram based on hypernatremia, heart failure, sepsis, APACHE II score, and initial creatinine and BE value in ICU can predict the individualized risk of AKI with satisfactory distinguishability and accuracy.

Phosphorus equivalency of phytase with various evaluation indicators of duck in starter.

This study was conducted to evaluate phosphorus (P) equivalency of phytase with various evaluation indicators of ducks in starter (0-14 days). Three hundred and twenty 1-day-old Cherry Valley ducks were randomly assigned to eight groups. The dietary treatments were four levels of available phosphorus (aP) with 0.25%, 0.32%, 0.39%, and 0.46% (treatments I-IV) and four levels of phytase added to low-aP basal diet (treatment I) with 300, 600, 900, and 1200 units (U) per kg (treatments V-VIII). The results were that compared to treatment I, increasing aP and supplementary phytase significantly (p < 0.05) improved body weight (BW), BW gain (BWG), feed intake (FI), live BW, carcass weight, semieviscerated weight, eviscerated weight, leg muscle weight, and decreased feed conversion ratio (FCR). Treatments V and VI did not significantly increase tibia ash, tibia calcium, and tibia P of 14-day-old ducks (p > 0.05). Following the increase of aP level (treatments I-IV), apparent utilization of Ca and P of ducks increased with varying degrees. With the increase of dietary phytase level (treatments V-VIII), the apparent utilization of Ca and P showed no significant difference (p > 0.05) but an increasing trend. Serum P reached the highest level when adding 600 U/kg phytase (treatment VI). Serum Ca and serum alkaline phosphatase activity showed no significant difference among treatments V-VIII (p > 0.05). Based on corn-soybean-rapeseed meal diet, with the evaluation indexes of FI, BWG, tibia ash, tibia Ca, tibia P, and apparent utilization of Ca and P, the addition of 500 U/kg phytase could release aP of 0.03%, 0.04%, 0.02%, 0.01%, 0.02%, 0.08%, and 0.07%, respectively. On the same way, the addition of 1000 U/kg phytase could release aP of 0.07%, 0.09%, 0.06%, 0.02%, 0.07%, 0.09%, and 0.09%, respectively.

Impact of Cumulative Fluid Balance During Continuous Renal Replacement Therapy on Mortality in Patients With Septic Acute Kidney Injury: A Retrospective Cohort Study.

Background: The clinicians often use continuous renal replacement therapy (CRRT) for the fluid management of patients with septic acute kidney injury (AKI). However, there is limited knowledge of the effects of changes in fluid balance (FB) on CRRT and its association with outcomes in patients with septic AKI. Objective: This study aimed to determine the association of cumulative FB (CFB) during treatment with 28-day all-cause mortality in the patients with septic AKI who require CRRT. Methods: This retrospective observational study examined patients who received CRRT due to septic AKI in a mixed intensive care unit (ICU) of a tertiary teaching hospital between January 2015 and December 2018. The patients were divided into three groups-negative FB, even FB, and positive FB-based on the CFB during CRRT. The primary outcome was 28-day all-cause mortality. Results: We examined 227 eligible patients and the mean age was 62.4 ± 18.3 years. The even FB group had a significantly lower 28-day mortality (43.0%, p = 0.007) than the positive FB group (72.7%) and the negative FB group (54.8%). The unadjusted and adjusted Cox regression models indicated that the positive FB group had an increased risk for 28-day all-cause mortality relative to the even FB group. A restricted cubic splines model indicated a J-shaped association between the CFB and 28-day all-cause mortality in the unadjusted model. Conclusion: Among the critically ill patients with septic AKI who require CRRT, those with positive FB had a higher mortality rate than those with even FB.

Phosphorus equivalency of phytase with various evaluation indicators of meat duck.

The objective of the present experiment was to determine the efficacy and the phosphorus (P) equivalency of phytase in the corn-soybean meal-rapeseed meal diets of Cherry Valley ducks from 1 to 35 d of age. 320 ducks were randomly divided into 8 blocks of 5 cages with 8 ducks per cage. This experiment included eight treatments diets. The available P levels of I to IV treatments were respectively 0.25%, 0.32%, 0.39%, 0.46% (d 1-14) and 0.20%, 0.27%, 0.34%, 0.41% (d 15-35). And 4 levels of phytase added to low-P basal diet (treatment I) with 300, 600, 900, and 1,200 U/kg (treatment V to VIII). Among them, treatment IV was a P-adequate positive control, treatment I was a low-P negative control. The ratio of calcium (Ca) to P was 1.3:1 for all diets. The other nutritional indexes in all diets were basically the same. Ducks were provided ad libitum access to water and experimental diets. The negative control diet reduced (P < 0.05) body weight, carcase weight, eviscerated weigh, breast muscle weight, leg muscle weight, bone ash, tibia Ca and tibia P, and increasing levels of available P and supplementary phytase significantly (P < 0.05) improved the growth performance and slaughtering performance of meat ducks. Phytase supplementation at a dose of 900 U/kg in the low-P basal diet increased the growth performance of ducks to a level comparable to that of a P-adequate diet. The available P level of 0.39% (1-14 d) and 0.34% (15-35 d) could meet the nutritional needs of meat ducks for P, and the apparent P utilization rate was high, and the effective utilization effect of P was the best. In addition, with the evaluation indexes of feed intake, body weight gain, tibia ash, tibia Ca, tibia P, content of blood Ca and P, the addition of 500 U/kg phytase could release available P of 0.02%, 0.02%, 0.02%, 0.02%, 0.01%, 0.04%, and 0.03%, respectively. In the same way, the addition of 1,000 U/kg phytase could release available phosphorus of 0.14%, 0.04%, 0.04%, 0.05%, 0.02%, 0.12%, and 0.01%, respectively.

Salidroside Activates the AMP-Activated Protein Kinase Pathway to Suppress Nonalcoholic Steatohepatitis in Mice.

BACKGROUND AND AIMS: NASH is becoming a leading cause of liver cirrhosis and HCC. Salidroside (p-hydroxyphenethyl-ß-D-glucoside; SAL) has various biological and pharmacological activities, including anti-inflammatory, -oxidant, and -cancer activities. However, the therapeutic effect and underlying molecular mechanism of SAL in NASH remain to be further clarified. METHODS AND RESULTS: In this study, we found that SAL alleviated lipid accumulation and inflammatory response in primary hepatocytes after palmitic acid/oleic acid (PO) stimulation. In addition, SAL effectively prevented high-fat/high-cholesterol (HFHC)-diet-induced NASH progression by regulating glucose metabolism dysregulation, insulin resistance, lipid accumulation, inflammation, and fibrosis. Mechanistically, integrated RNA-sequencing and bioinformatic analysis showed that SAL promoted AMPK-signaling pathway activation in vitro and in vivo, and this finding was further verified by determining the phosphorylation levels of AMPK. Furthermore, the protective effects of SAL on lipid accumulation and inflammation in hepatocytes and livers induced by PO or HFHC stimulation were blocked by AMPK interruption. CONCLUSIONS: Our studies demonstrate that SAL protects against metabolic-stress-induced NASH progression through activation of AMPK signaling, indicating that SAL could be a potential drug component for NASH therapy.

Effect of seasonal thermal stress on oxidative status, immune response and stress hormones of lactating dairy cows.

This study aimed to assess the impact of seasonal thermal stress on oxidative stress, immune response, and stress hormones of lactating dairy cows in subtropical regions with different levels of temperature-humidity index (THI). A total of 32 healthy lactating Holstein dairy cows experienced 4 seasons (8 cows/season). The physiological parameters were categorized into low THI (LTHI, THI = 42.97 ± 0.95) in winter, moderate THI (MTHI, THI = 61.84 ± 0.42) in spring and autumn, and high THI period (HTHI, THI = 86.09 ± 0.23) in summer. The blood samples were collected twice in each season to measure oxidative stress, inflammatory and hormonal parameters. Our results showed THI had a positive correlation with the rectal temperature (R 2 = 0.821, P < 0.001) and respiratory rate (R 2 = 0.816, P < 0.001). Dry matter intake, milk yield and fat percentage also significantly differed among groups (P < 0.05). Compared with the MTHI group, the LTHI group exhibited a significant increase in malondialdehyde (MDA) level (P < 0.001), and the HTHI group displayed a significant increase in levels of cortisol, interleukin (IL)-10, IL-1ß and tumor necrosis factor-α (P < 0.001). Opposite changes in serum endotoxin and immunoglobulin G levels were observed with the increasing THI (P < 0.001). LTHI notably increased the triiodothyronine level, although the thyroxine level was reduced by LTHI and HTHI compared with the MTHI group. In conclusion, LTHI and HTHI conditions may induce different degrees of oxidative stress, inflammation response, and stress hormone imbalances on lactating dairy cows, therefore environmental management is necessary for the health of dairy cows in extreme weather conditions.

Relationships among bedding materials, bedding bacterial composition and lameness in dairy cows.

OBJECTIVE: Bedding materials directly contact hooves of dairy cows and they may serve as environmental sources of lameness-associated pathogen. However, the specific composition of bacteria hidden in bedding materials is still not clear. The aim of this study was to determine the effect bedding material and its bacterial composition has on lameness of Holstein heifers. METHODS: Forty-eight Holstein heifers with similar body weights were randomly assigned into three groups including sand bedding (SB), concrete floor (CF), and compost bedding (CB). Hock injuries severity and gait performance of dairy cows were scored individually once a week. Blood samples were collected at the end of the experiment and bedding material samples were collected once a week for Illumina sequencing. RESULTS: The CF increased visible hock injuries severity and serum biomarkers of joint damage in comparison to SB and CB groups. Besides, Illumina sequencing and analysis showed that the bacterial community of CB samples had higher similarity to that of SB samples than CF samples. Bacteria in three bedding materials were dominated by gastrointestinal bacteria and organic matter-degrading bacteria, such as Actinobacteria, Firmicutes, and norank JG30-KF-cM45. Lameness-associated Spirochaetaceae and Treponeme were only detected in SB and CB samples with a very low relative abundance (0% to 0.08%). CONCLUSION: The bacterial communities differed among bedding materials. However, the treponemes pathogens involved in the pathogenesis of lameness may not be a part of microbiota in bedding materials of dairy cows.

Japanese encephalitis following liver transplantation: A rare case report.

BACKGROUND: Japanese encephalitis (JE) is a serious public health concern with a high mortality rate in many Asian countries. For many years, JE virus (JEV) was considered the major cause of viral encephalitis in Asia. Although most JE cases are asymptomatic, the case fatality rate approaches 30%, and approximately 30%-50% of survivors have long-term neurological sequelae. To the best of our knowledge, JEV infection has never been reported following liver transplantation. CASE SUMMARY: We report a case of a woman who underwent liver transplantation for autoimmune liver disease but presented with fever and neurological symptoms 13 d after transplantation. Magnetic resonance imaging revealed JEV infection, and positive immunoglobulin M antibody to JEV in blood and cerebrospinal fluid confirmed JE. The patient was treated with antiviral agents, immune regulation, and organ function support. No neurological sequelae were present after 1 year of follow-up. CONCLUSION: Imaging and lumbar puncture examination should be performed as soon as possible in patients with fever and central nervous system symptoms after liver transplantation, and the possibility of atypical infection should be considered, which is helpful for early diagnosis and improved prognosis.

Impact of yeast and lactic acid bacteria on mastitis and milk microbiota composition of dairy cows.

This experiment was conducted to evaluate the impact of yeast and lactic acid bacteria (LAB) on mastitis and milk microbiota composition of dairy cows. Thirty lactating Holstein cows with similar parity, days in milk were randomly assigned to five treatments, including: (1) Health cows with milk SCC < 500,000 cells/mL, no clinical signs of mastitis were found, fed basal total mixed ration (TMR) without supplementation (H); (2) Mastitis cows with milk SCC > 500,000 cells/mL, fed basal TMR without supplementation (M); (3) Mastitis cows fed basal TMR supplemented with 8 g day-1 yeast (M + Y); (4) Mastitis cows fed basal TMR supplemented with 8 g day-1 LAB (M + L); (5) Mastitis cows (milk SCC > 500,000 cells/mL) fed basal TMR supplemented with 4 g day-1 yeast and 4 g day-1 LAB (M + Y + L). Blood and milk sample were collected at day 0, day 20 and day 40. The results showed efficacy of probiotic: On day 20 and day 40, milk SCC in H, M + Y, M + L, M + Y + L was significantly lower than that of M (P < 0.05). Milk concentration of TNF-α, IL-6 and IL-1ß in M + Y + L were significantly reduced compared with that of M on day 40 (P < 0.05). Milk Myeloperoxidase (MPO) and N-Acetyl-ß-D-Glucosaminidase (NAG) activity of M + Y, M + L, M + L + Y were lower than that of M on day 40 (P < 0.05). At genus level, Staphylococcus, Chryseobacterium and Lactococcus were dominant. Supplementation of LAB decreased abundance of Enterococcus and Streptococcus, identified as mastitis-causing pathogen. The results suggested the potential of LAB to prevent mastitis by relieving mammary gland inflammation and regulating milk microorganisms.

Effect of different seasons (spring vs summer) on the microbiota diversity in the feces of dairy cows.

We aimed to study how seasonal heat stress (i.e., spring vs. summer) influenced microbiota diversity in the dairy cows' feces using Illumina MiSeq sequencing. Sixteen dairy cows were experiencing spring thermoneutral conditions (daily mean temperature = 18.8 ± 3.40 °; daily mean THI = 64.29 ± 4.94) and 16 under summer heat stress (daily mean temperature = 27.63 ± 5.34 °; daily mean THI = 82.56 ± 1.74). Fecal samples were collected per cow three times daily from day 18 to day 22 during each experimental period. Results revealed that the microbiota diversity in the feces was significantly lower (P < 0.05) under summer heat stress. At both the phylum and genera levels, significant differences were observed on microbiota composition in cow's feces between spring and summer. The most dominant phylum was Firmicutes, contributing 69.45% and 87.14% of the fecal microbiota in spring and summer, respectively, followed by Bacteroidetes, contributing 25.27% and 4.45%, respectively. Compared with the dairy cows in the spring season, the relative abundance of unclassified Peptostreptococcaceae, Turicibacter, and Clostridium_sensu_stricto_1 (P < 0.05) were greatly increased (P < 0.05), while the significant decrease in the proportion of Ruminococcaceae_UCG-005 and Rikenellaceae_RC9_gut_group as well as Bacteroides were observed in hot summer. Prediction of microbiota gene function in feces based on PICRUSt method found that different microbiota between spring and summer were mainly concentrated on the function related to membrane transport, infectious diseases, immune system diseases, and lipid metabolism. This study demonstrates that diversity and composition of fecal microbiota in dairy cows varies under different THI condition, and the relationship between fecal microbiota and cows' health needs further research.

Effects of chromium picolinate supplementation on growth performance, small intestine morphology and antioxidant status in ducks under heat stress conditions / Efectos de la suplementación con picolinato de cromo en el rendimiento de crecimiento, morfología del intestino delgado y estado antioxidante en patos bajo condiciones de estrés calórico

SUMMARY: The experiment was conducted to evaluate the effects of dietary supplemental chromium (Cr) on growth performance, meat quality, intestinal morphology, mucosa Hsp70 mRNA expression and antioxidant status of ducks reared under heat stress conditions. All ducks were randomly divided into three treatment groups, respectively, control group (Control, 23 ± 2 °C), heat stress group (HS, 32 ±2 °C), Cr picolinate group (CrPic, 32 ± 2 °C, 0.2 mg Cr/kg). Feed and distilled-deionized water were available ad libitum for an experimental phase of 35 days. Samples were collected on the day 14, 21 and 35 to determine biological and hematological values. Results showed that heat stress or dietary supplemental Cr both didn't have distinct influence on growth performance (P>0.05), compared to controls. Ducks fed 0.2 mg Cr/kg diet had greater ultimate pH (pHu)(P<0.05) than HS group. At day 14, the ratio of villus height to crypt depth (V/C) in CrPic group significantly increased (P<0.05) than that of HS group in jejunum. Heat stress remarkably increased Hsp70 mRNA expression in jejunum compared with controls (P<0.05). While the expression of Hsp70 mRNA in CrPic group was significantly decreased compared with HS (P<0.05). At day 21, the V/C of ileum in CrPic group significantly increased compared with HS group (P<0.05). Serum SOD levels in CrPic group were significantly higher than those in HS group (P<0.05). At day 35, Hsp70 mRNA expression and serum T-SOD levels in CrPic group significantly increased compared with controls (P<0.05). T-AOC in HS group significantly decreased compared with controls (P<0.05). Results indicate that dietary Cr supplementation doesn't influence ducks' growth performance, but has a positive effect on meat quality, small intestine morphology, also regulates Hsp70 mRNA expression under heat stress conditions, and enhances the antioxidant status.

RESUMEN: Se evaluó los efectos del cromo (Cr) dietético suplementario sobre el rendimiento del crecimiento, la calidad de la carne, la morfología intestinal, la expresión del ARNm Hsp70 en la mucosa y el estado antioxidante de los patos criados bajo condiciones de estrés por calor. Todos los patos se dividieron aleatoriamente en tres grupos: grupo control (control, 23 ± 2 °C), grupo de estrés térmico (HS, 32 ± 2 °C) y grupo de picolinato de Cr (CrPic, 32 ± 2 °C, 0,2 mg Cr / kg). El alimento y el agua desionizada destilada estuvieron disponibles ad libitum durante la fase experimental de 35 días. Las muestras se recogieron los días 14, 21 y 35 para determinar los valores biológicos y hematológicos. Los resultados mostraron que el estrés térmico o la suplementación dietética de Cr no tuvieron una influencia distinta en el rendimiento del crecimiento (P> 0,05), en comparación con los controles. Los patos alimentados con 0,2 mg de Cr / kg de dieta tuvieron un mayor pH final (pHu) (P <0,05) que el grupo HS. En el día 14, la relación de la altura de las vellosidades a la profundidad de la cripta (V / C) en el grupo CrPic aumentó significativamente (P <0,05) en relación a la del grupo de HS en el yeyuno. El estrés por calor incrementó notablemente la expresión del ARNm de Hsp70 en el yeyuno en comparación con los controles (P <0,05). Mientras que la expresión del ARNm de Hsp70 en el grupo CrPic se redujo significativamente en comparación con HS (P <0,05). En el día 21, la relación V / C del íleon en el grupo CrPic aumentó significativamente en comparación con el grupo HS (p <0,05). Los niveles séricos de SOD en el grupo CrPic fueron significativamente más altos que los del grupo HS (P <0,05). En el día 35, la expresión de ARNm de Hsp70 y los niveles séricos de T-SOD en el grupo CrPic aumentaron significativamente en comparación con los controles (P <0,05). T-AOC en el grupo HS disminuyó significativamente en comparación con los controles (P <0,05). Los resultados indican que la suplementación dietética de Cr no influye en el rendimiento de crecimiento de los patos, pero tiene un efecto positivo en la calidad de la carne, en la morfología del intestino delgado, y también regula la expresión de ARNm de Hsp70 en condiciones de estrés calórico y mejora el estado antioxidante.

Methionine metabolism in piglets Fed DL-methionine or its hydroxy analogue was affected by distribution of enzymes oxidizing these sources to keto-methionine.

Previous evidence shows that the extensive catabolism of dietary essential amino acids (AA) by the intestine results in decreased availability of these AA for protein synthesis in extraintestinal tissues. This raises the possibility that extraintestinal availability of AA may be improved by supplying the animal with an AA source more of which can bypass the intestine. To test this hypothesis, six barrows (35-day-old, 8.6 +/- 1.4 kg), implanted with arterial, portal, and mesenteric catheters, were fed a DL-methionine (DL-MET) or DL-2-hydroxy-4-methylthiobutyrate (DL-HMTB) diet once hourly and infused intramesenterically with 1% p-amino hippurate. Although the directly available L-MET in DL-MET diet was about 1.2-fold that in DL-HMTB diet, the net portal appearance of L-MET was not different between the two diets. Compared with the low mRNA abundance and low activity of D-2-hydroxy acid dehydrogenase (D-HADH) and l-2-hydroxy acid oxidase (L-HAOX) in the intestine, the high mRNA abundance and high activity of D-AA oxidase (D-AAOX) indicated that the intestine had a relatively higher capacity of D-MET utilization than of dl-HMTB utilization to L-MET synthesis and its subsequent metabolism. However, in contrast to the much lower D-AAOX activity (nmol/g tissue) in the stomach than in the liver and kidney, both d-HADH and L-HAOX activity in the stomach was comparable with those in the liver and/or kidney, indicating the substantial capacity of the stomach to convert DL-HMTB to L-MET. Collectively, the difference in distribution of activity and mRNA abundance of D-AAOX, D-HADH, and L-HAOX in the piglets may offer a biological basis for the similar portal appearance of L-MET between DL-MET and DL-HMTB diets, and thus may provide new important insights into nutritional efficiency of different L-MET sources.

[Construction of anti-lung tumor gene differentially expressed bank of wild mouse].

OBJECTIVE: To construct the anti-lung tumor gene differentially expressed bank of wild mouse and to explore the mechanisms of the TW wild mouse suppressing the occurring of lung tumor. METHODS: Using suppression subtractive hybridization (SSH) technique, the differentially expressed genes between TAF1 mouse and A/wy mouse were selected out and the subtracted cDNA bank was constructed. 166 clones were performed DNA sequencing and then were assayed by blast programme. RESULTS: Among the blast results of 166 differentially expressed clones, 87 known genes (mRNA or cDNA) were in homology with 134 clones and were divided into 7 classifications according to the biological role.14 DNA fragments were in homology with 32 clones, in which 20 clones were in homology with 9 mouse DNA sequences, 2 clones were in homology with one bacterial gene sequences and 3 clones were clone vector. CONCLUSION: With SSH technique, the anti-lung tumor gene differentially expressed bank of wild mouse are successfully constructed.