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In this paper, a terahertz metamaterial refractive index sensor based on electromagnetically induced transparency effect is proposed. The unit structure is composed of a closed square ring and a split circular ring. The transmission spectrum of the sensor generates sharp transparent peak at around 0.615 THz. Geometric factors on transmittance were simulated and analyzed, including the size of the opening ring, the distance between the two rings, the circular ring radius, and the refractive index of the tested object. Subsequently, the sensing performance of the device was also studied with a refractive index sensitivity of 3.68 µm/RIU. [ABSTRACT FROM AUTHOR]

A nano resonator is designed consisting of the metal-insulator-metal (MIM) waveguide coupled with the concentric annulus cavity. The optical transmission characteristics and sensing characteristics of the designed sensor are studied by using finite element method. Experimental results show that the combination of the MIM waveguide and the concentric annulus cavity can produce bright mode and dark mode around the central wavelength of 565 nm. Due to the interaction between these modes, the Fano resonance phenomenon will be produced with a transitional dip around the wavelength of 585 nm. Compared with the impacts of the width of the metal baffle and the coupling gap, the Fano resonance effect is very sensitive to the variation of the radii of the concentric annulus cavity, which is helpful to design the tunable optical devices based on Fano resonance in the future. However the modulation depth is obviously influenced by the width of the metal baffle and the coupling gap. The research also demonstrates the sharp asymmetric Fano transmission spectrum is also sensitive to the surrounding medium. By calculating the shift of the resonant wavelength with the change of the refractive index of the medium in the resonator, the device can achieve the sensitivity of 550 nm/RIU and the figure of merit of 70. [ABSTRACT FROM AUTHOR]

The accurate detection of external defects in kiwifruit is an important part of postharvest quality assessment. Previous studies have not considered the problems posed by the actual grading environment. In this study, we designed a novel approach based on improved Yolov5 to achieve real-time and efficient non-destructive detection of multiple defect categories in kiwifruit. First, a kiwifruit image acquisition device based on grading lines was developed to enhance the image acquisition. Subsequently, a kiwifruit dataset was constructed based on the external defect characteristics and a new data enhancement method was proposed to augment the kiwifruit samples. Thereafter, the SPD-Conv and DW-Conv modules were combined to improve Yolov5s, with EIOU as the loss calculation function. The results demonstrated that the improved model training loss value was 0.013 lower, the convergence was accelerated, the number of parameters was reduced, and the computational effort was increased. The detection accuracies of the samples in the test set, which included healthy, leaf-rubbing damaged, healed cuts or scarred, and sunburned samples, were 98.8%, 98.7%, 97.6%, and 95.9%, respectively, with an overall detection accuracy of 97.7%. The detection time was 8.0 ms, thereby meeting real-time sorting demands. The average detection accuracy and model size of SSD, Yolov5s, Yolov7, and Yolov5-Ours were compared. When the confidence threshold was 0.5, the detection accuracy of Yolov5-Ours was 10% and 6.4% higher than that of SSD and Yolov5s, respectively. In terms of the model size, Yolov5-Ours was approximately 6.5- and 4-fold smaller than SSD and Yolov7, respectively. Thus, Yolov5-Ours achieved the highest accuracy, adaptability, and robustness for the detection of all kiwifruit categories as well as a small volume and portability. These results can provide technical support for the non-destructive detection and grading of agricultural products in the future. [ABSTRACT FROM AUTHOR]

In order to solve the problems of low sensitivity and complex structure of surface –plasmon- polariton (SPP) sensor at the present stage, a highly sensitive and stable SPP sensor composed of metal-insulator-metal (MIM) waveguide, a stub and a resonant cavity is proposed. The diameter of the MIM waveguide is chosen to be 50 nm so that only the single mode exists. The radius and refractive index of the cavity can vary, which is imbedded in silver background so that SPP phenomenon can be produced. The optical transmission characteristics and sensing characteristics of the designed sensor are studied by using finite element method. Experimental results show that the combination of the MIM waveguide and the stub can produce continuous state and the cavity can produce discrete state at the wavelength of 830 nm. At the same time, our research also demonstrates the sharp asymmetric Fano transmission spectrum is also sensitive to the surrounding medium. The application of the designed device in the field of refractive index sensing is also studied by calculating the shift of the resonant wavelength with the change of the refractive index of the medium in the resonator. The device can achieve refractive index sensing performance with the sensitivity of 803 nm/RIU and the figure of merit of 121. [ABSTRACT FROM AUTHOR]

Context: Glucagon-like peptide-1 receptor agonists (GLP-1RAs) and sodium-glucose cotransporter-2 inhibitors (SGLT2is) are used off-label in the management of type 1 diabetes mellitus (T1DM) in real-world practice as adjuvant therapies to insulin. There are few real-world data regarding efficacy and safety of this practice. Objective: This work aimed to determine the efficacy and safety of GLP-1RAs and sodium-glucose SGLT2is in the management of T1DM in realworld practice. Methods: A retrospective chart review was performed of all instances of GLP-1RA and/or SGLT2i use greater than 90 days in adult patients with T1DM at a single academic center. We report the clinical and safety outcomes over the duration of use. Results: We identified 104 patients with T1DM who ever used a GLP-1RA (76 patients) or SGLT2i (39 patients) for more than 90 days. After 1 year of therapy, GLP-1RA users had statistically significant reductions in weight (90.5 kg to 85.4 kg; P< .001), glycated hemoglobin A1c (HbA1c) (7.7% to 7.3%; P=.007), and total daily dose of insulin (61.8 units to 41.9 units; P<.001). SGLT2i users had statistically significant reductions in HbA1c (7.9% to 7.3%; P<.001) and basal insulin (31.3 units to 25.6 units; P=.003). GLP-1RA users compared to SGLT2i users had greater reduction in weight (P=.027) while HbA1c reduction was comparable between the groups. Over a mean total duration of use of 29.5 months/patient for both groups, more SGLT2i users experienced diabetic ketoacidosis (DKA) (12.8% vs 3.9%). Therapy was discontinued because of adverse events 26.9% of the time for GLP-1RA users vs 27.7% for SGLT2i users. Conclusion: GLP-1RA and SGLT2i use in T1DM is associated with clinically relevant benefits. DKA remains a clinical concern with SGLT2i use, requiring careful patient selection and monitoring, with the risk to benefit ratio of treatment evaluated at an individual level. [ABSTRACT FROM AUTHOR]

Chenodeoxycholic acid (CDCA), a primary bile acid (BA), has been demonstrated to play an important role as a signaling molecule in various physiological functions. However, the role of CDCA in regulating intestinal epithelial cell (IEC) function remains largely unknown. Herein, porcine intestinal epithelial cells (IPEC-J2) were used as an in vitro model to investigate the effects of CDCA on IEC proliferation and explore the underlying mechanisms. IPEC-J2 cells were treated with CDCA, and flow cytometry and transcriptome analysis were adopted to investigate the effects and potential molecular mechanisms of CDCA on the proliferation of IECs. Our results indicated that adding 50 µmol/L of CDCA in the media significantly increased the proliferation of IPECJ2 cells. In addition, CDCA treatment also hindered cell apoptosis, increased the proportion of G0/G1 phase cells in the cell cycle progression, reduced intracellular ROS, and MDA levels, and increased mitochondrial membrane potential, antioxidation enzyme activity (T-AOC and CAT), and intracellular ATP level (p < 0.05). RNA-seq results showed that CDCA significantly upregulated the expression of genes related to cell cycle progression (Cyclin-dependent kinase 1 (CDK1), cyclin G2 (CCNG2), cell-cycle progression gene 1 (CCPG1), Bcl-2 interacting protein 5 (BNIP5), etc.) and downregulated the expression of genes related to mitochondrial biogenesis (ND1, ND2, COX3, ATP6, etc.). Further KEGG pathway enrichment analysis showed that CDCA significantly enriched the signaling pathways of DNA replication, cell cycle, and p53. Collectively, this study demonstrated that CDCA could promote IPEC-J2 proliferation by regulating cell cycle progression and mitochondrial function. These findings provide a new strategy for promoting the intestinal health of pigs by regulating intestinal BA metabolism. [ABSTRACT FROM AUTHOR]

Background: An in silico screen was performed to identify FDA approved drugs that inhibit SARS-CoV-2 main protease (Mpro), followed by in vitro viral replication assays, and in vivo pharmacokinetic studies in mice. These studies identified atovaquone as a promising candidate for inhibiting viral replication. Methods: A 2-center, randomized, double-blind, placebo-controlled trial was performed among patients hospitalized with COVID-19 infection. Enrolled patients were randomized 2:1 to atovaquone 1500 mg BID versus matched placebo. Patients received standard of care treatment including remdesivir, dexamethasone, or convalescent plasma as deemed necessary by the treating team. Saliva was collected at baseline and twice per day for up to 10 days for RNA extraction for SARS-CoV-2 viral load measurement by quantitative reverse-transcriptase PCR. The primary outcome was the between group difference in log-transformed viral load (copies/mL) using a generalized linear mixed-effect models of repeated measures from all samples. Results: Of the 61 patients enrolled; 41 received atovaquone and 19 received placebo. Overall, the population was predominately male (63%) and Hispanic (70%), with a mean age of 51 years, enrolled a mean of 5 days from symptom onset. The log10 viral load was 5.25 copies/mL vs. 4.79 copies/mL at baseline in the atovaquone vs. placebo group. Change in viral load did not differ over time between the atovaquone plus standard of care arm versus the placebo plus standard of care arm. Pharmacokinetic (PK) studies of atovaquone plasma concentration demonstrated a wide variation in atovaquone levels, with an inverse correlation between BMI and atovaquone levels, (Rho -0.45, p = 0.02). In post hoc analysis, an inverse correlation was observed between atovaquone levels and viral load (Rho -0.54, p = 0.005). Conclusion: In this prospective, randomized, placebo-controlled trial, atovaquone did not demonstrate evidence of enhanced SARS-CoV-2 viral clearance compared with placebo. However, based on the observed inverse correlation between atovaquone levels and viral load, additional PK-guided studies may be warranted to examine the antiviral effect of atovaquone in COVID-19 patients. [ABSTRACT FROM AUTHOR]

Objectives: An increasing percentage of the US population is obese. Cardiometabolic risk in the population increases with body mass index (BMI), but whether this correlation changes over time is unknown. We analysed the National Health and Nutrition Examination Survey (NHANES) database from 1999 to 2016 to determine if the prevalence of cardiometabolic disease and cardiovascular events within each BMI category is changing over time as the BMI of the population is increasing.Study Design: For each of the nine survey cycles covering this period, we divided the population by BMI category (normal, overweight, class 1 obesity, class ≥2 obesity) and subsequently by the presence of cardiovascular events or cardiometabolic disease. NHANES participants are a group of 5000 individuals/cycle selected to be representative of the US population. We used the weighted data sets to perform trend analyses for each risk/BMI group adjusted for relevant confounders.Results: The distribution of the highest risk category (cardiovascular event) has not changed over time within any BMI category. The distribution of the lowest risk category (cardiometabolically healthy) increased significantly over time in all BMI categories. This was noted in the 18- to 45-year subgroup but not in the group aged >45 years.Conclusions: The increase in the prevalence of overweight and obese individuals might be associated with a 'healthy obesity' phenotype in those <45 years; however, individuals >45 years showed a proportional increase in associated cardiometabolic risk. [ABSTRACT FROM AUTHOR]

Hypomagnesemia associates with inflammation and risk of diabetes and hypertension, which may contribute to kidney function decline. We hypothesized that low serum magnesium (SMg) levels independently associate with a significant decline in estimated glomerular filtration rate (eGFR). We analyzed SMg levels in 2056 participants from the Dallas Heart Study, a longitudinal, populationbased, multiethnic, cohort study involving residents of Dallas County, Texas, USA. The primary study outcome was the change in eGFR using multivariable linear regression models adjusted for demographics, anthropometric and biochemical parameters, medications, C reactive protein levels, prevalent hypertension and diabetes. During a median followup of 7.0 years (25th, 75th percentile: 6.5, 7.6), the median decrease in eGFR was -0.71 (25th, 75th percentile: -2.43, +0.68) mL/min/1.73 m2 per year in the entire cohort. In a fully adjusted model, the lowest SMg quintile (=1.9 mg/dL or =0.8 mM) was associated with a -0.50 mL/min/1.73 m2 per year drop in eGFR (95% CI -0.95 to -0.05; p=0.028) compared with the highest SMg quintile (=2.3 mg/dL or =1.0 mM). Every 0.2 mg/dL (0.08 mM) decrease in SMg was associated with an eGFR decline of -0.23 mL/min/1.73 m² per year (95% CI -0.38 to -0.08; p=0.003), a decline that was more pronounced in participants with prevalent diabetes compared with patients without diabetes (-0.51 vs -0.18 mL/min/1.73 m² per year, respectively). In conclusion, low SMg was independently associated with eGFR decline. Further studies are needed to determine whether Mg repletion can ameliorate inflammation, lower blood pressure and serum glucose and ultimately prevent or retard kidney function decline. [ABSTRACT FROM AUTHOR]

Objective: To compare infant and toddler anthropometric measurements, feeding practices and mean nutrient intakes by race/ethnicity and income.Design: Cross-sectional analysis using general linear modelling. Ten years of survey data (2003-2012) were combined to compare anthropometric measurements, feeding practices and mean nutrient intakes from a nationally representative US sample.Setting: The 2003-2012 National Health and Nutrition Examination Survey (NHANES).Subjects: Infants and toddlers (n 3669) aged 0-24 months.Results: Rates of overweight were higher among Mexican-American infants and toddlers (P=0·002). There were also several differences in feeding practices among groups based on race/ethnicity. Cessation of breast-feeding occurred earlier for non-Hispanic black and Mexican-American v. non-Hispanic white infants (3·6 and 4·2 v. 5·3 months; P<0·0001; P=0·001). Age at first feeding of solids was earlier for white than Mexican-American infants (5·3 v. 5·7 months; P=0·02). There were differences in almost all feeding practices based on income, including the lowest-income infants stopped breast-feeding earlier than the highest-income infants (3·2 v. 5·8 months, P<0·0001). Several differences in mean nutrient intakes by both race/ethnicity and income were also identified.Conclusions: Our study indicates that disparities in overweight, feeding practices and mean nutrient intakes exist among infants and toddlers according to race/ethnicity, which cannot be disentangled from income. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effect of Astragalus polysaccharide (APS) supplementation on the growth performance, plasma biochemical parameters, and plasma immune and antioxidant indexes of weaned piglets in a commercial swine farm. A total of 120 piglets weaned at 22 days and allocated to 2 groups, and fed a basal diet either without (CTR) or with 200 mg/kg of APS in a local commercial farm for a 42-d experiment. At end of the trial, one piglet from each pen was selected for blood sampling. The results showed that dietary APS decreased the feed conversion ratio (FCR) compared to the CTR group from day 14 to day 28 and day 0 to day 42 (P = 0.08 and 0.02, respectively). In addition, supplementation of APS had the tendency to increase the plasma superoxide dismutase activity and IgG content of piglets compared to the CTR group on day 42 (P = 0.06 and 0.09, respectively). Results in this study suggested that dietary APS might have a beneficial effect on growth performance and health status of weaned piglets under the commercial condition. [ABSTRACT FROM AUTHOR]

The gas molecule nitric oxide (NO) can cooperate with ethylene to tightly modulate plant growth and stress responses. One of the mechanism of their crosstalk is that NO is able to activate ethylene biosynthesis, possibly through post-translational modification of key enzymes such as ACC synthase and oxidase by S-nitrosylation. In this paper, we focus on the crosstalk of NO with ethylene signaling transduction transcription factor EIN3 (Ethylene Insensitive 3) and downstream gene expression in alleviating germination inhibition and growth damage induced by high salt. The Arabidopsis lines affected in ethylene signaling (ein3eil1) and NO biosynthesis (nia1nia2) were employed to compare with the wild-type Col-0 and overexpressing line EIN3ox. Firstly, the obviously inhibited germination, greater ratio of bleached leaves and enhanced electrolyte leakage were found in ein3eil1 and nia1nia2 lines than in Col-0 plants upon high salinity. However, the line EIN3ox obtained a notably elevated ability to germinate and improved seedling resistance. The experiment with SNP alone or plus high salt mostly enhanced the expression of EIN3 transcripts, compared with ACO4 and ACS2. The western blot and transcript analysis found that high-salt-induced EIN3 stabilization and EIN3 transcripts were largely attenuated in the NO biogenesis mutant nia1nia2 plants than in Col-0 ones. This observation was confirmed by simulation experiments with NO scavenger cPTIO to block NO emission. Taken together, our study provides insights that NO promotes seed germination and seedlings growth under salinity may depend on EIN3 protein. [ABSTRACT FROM AUTHOR]

This study tested the hypothesis that l-arginine (Arg) may stimulate cell proliferation and prevent lipopolysaccharide (LPS)-induced death of intestinal cells. Intestinal porcine epithelial cells (IPEC-1) were cultured for 4 days in Arg-free Dulbecco’s modified Eagle’s-F12 Ham medium (DMEM-F12) containing 10, 100 or 350 μM Arg and 0 or 20 ng/ml LPS. Cell numbers, protein concentrations, protein synthesis and degradation, as well as mammalian target of rapamycin (mTOR) and Toll-like receptor 4 (TLR4) signaling pathways were determined. Without LPS, IPEC-1 cells exhibited time- and Arg-dependent growth curves. LPS treatment increased cell death and reduced protein concentrations in IPEC-1 cells. Addition of 100 and 350 μM Arg to culture medium dose-dependently attenuated LPS-induced cell death and reduction of protein concentrations, in comparison with the basal medium containing 10 μM Arg. Furthermore, supplementation of 100 and 350 μM Arg increased protein synthesis and reduced protein degradation in both control and LPS-treated IPEC-1 cells. Consistent with the data on cell growth and protein turnover, addition of 100 or 350 μM Arg to culture medium increased relative protein levels for phosphorylated mTOR and phosphorylated ribosomal protein S6 kinase-1, while reducing the relative levels of TLR4 and phosphorylated levels of nuclear factor-κB in LPS-treated IPEC-1 cells. These results demonstrate a protective effect of Arg against LPS-induced enterocyte damage through mechanisms involving mTOR and TLR4 signaling pathways, as well as intracellular protein turnover. [ABSTRACT FROM AUTHOR]

Abstract  Cholesterol and docosahexaenoic acid (DHA) are important nutrients for neural development of infants. However, little is known about the effect of cholesterol or DHA on concentrations of amino acids (AA) in neonatal tissues. This study was conducted with the piglet (an established model for studying human infant nutrition) to test the hypothesis that dietary supplementation with the lipids may modulate AA availability in tissues. Sixteen newborn pigs were nursed by sows for 24 h and then assigned to one of four treatment groups, representing supplementation with 0.0% (control), 0.2% cholesterol, 0.2% DHA, or cholesterol plus DHA to the basal milk-formula. All piglets were euthanized at 49 days of age. In brain, cholesterol supplementation reduced (P P P  [ABSTRACT FROM AUTHOR]

Abstract  This study was conducted using the piglet model to test the hypothesis that mucosal cells of the neonatal small intestine can degrade nutritionally essential amino acids (EAA). Enterocytes were isolated from the jejunum of 0-, 7-, 14-, and 21-day-old pigs, and incubated for 45 min in Krebs buffer containing plasma concentrations of amino acids and one of the following L-[1-14C]- or L-[U-14C]-amino acids plus unlabeled tracees at 0.5, 2, or 5 mM: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine. In these cells, branched-chain amino acids (BCAA) were extensively transaminated and 15–50% of decarboxylated branched-chain α-ketoacids (BCKA) were oxidized to CO2 depending on the age of piglets. BCAA transamination increased but their decarboxylation decreased between 0 and 14 days of age. Addition of 1 and 2 mM α-ketoglutarate to incubation medium dose-dependently stimulated BCAA transamination without affecting their decarboxylation. Western blot analysis revealed that the abundance of mitochondrial BCAA aminotransferase declined but cytosolic BCAA aminotransferase increased between 0 and 14 days of age, with the cytosolic protein being the major isoform in 7- to 21-day-old pigs. BCKA dehydrogenase protein existed primarily as the phosphorylated (inactive) form in enterocytes of newborn pigs and its levels were markedly reduced in older pigs. All measured parameters of BCAA metabolism did not differ between 14- and 21-day-old pigs. In contrast to BCAA, catabolism of methionine and phenylalanine was negligible and that of other EAA was absent in enterocytes from all ages of piglets due to the lack of key enzymes. These results indicate that enterocytes are an important site for substantial degradation of BCAA but not other EAA in the neonatal gut. [ABSTRACT FROM AUTHOR]

Abstract  Gases, such as nitric oxide (NO), carbon monoxide (CO), hydrogen sulfide (H2S), and sulfur dioxide (SO2) are known toxic pollutants in the air. However, they are now recognized as important signaling molecules synthesized in animals and humans from arginine, glycine (heme), and cysteine, respectively. At physiological levels, NO, CO, and SO2 activate guanylyl cyclase to generate cGMP which elicits a variety of responses (including relaxation of vascular smooth muscle cells, hemodynamics, neurotransmission, and cell metabolism) via cGMP-dependent protein kinases. H2S is also a crucial regulator of both neurological function and endothelium-dependent relaxation through cGMP-independent mechanisms involving stimulation of membrane KATP channels and intracellular cAMP signaling. Additionally, NO, CO, and H2S confer cytoprotective and immunomodulatory effects. Moreover, NH3 is a major product of amino acid catabolism and profoundly affects the function of neurons and the vasculature through glutamine-dependent inhibition of NO synthesis. Emerging evidence shows that amino acids are not only precursors for these endogenous gases, but are also regulators of their production in a cell-specific manner. Thus, recent advances on gaseous signaling have greatly expanded our basic knowledge of amino acid biochemistry and nutrition. These exciting discoveries will aid in the design of new nutritional and pharmacological means to prevent and treat major health problems related to developmental biology and nutrient metabolism, including intrauterine growth restriction, preterm birth, aging, neurological disorders, cancer, obesity, diabetes, and cardiovascular disease. [ABSTRACT FROM AUTHOR]

Abstract  This study tested the hypothesis that L-glutamine (Gln) or L-alanyl-L-glutamine (Ala-Gln) prevents oxidant- or endotoxin-induced death of neonatal enterocytes. Enterocytes of neonatal pigs rapidly hydrolyzed Ala-Gln and utilized Gln. To determine whether Gln or Ala-Gln has a cytoprotective effect, IPEC-1 cells were cultured for 24 h in Gln-free Dulbecco’s modified Eagle’s-F12 Ham medium containing 0, 0.5, 2.0 or 5.0 mM Gln or Ala-Gln, and 0, 0.5 mM H2O2 or 30 ng/ml lipopolysaccharide (LPS). Without Gln or Ala-Gln, H2O2- or LPS-treated cells exhibited almost complete death. Gln or Ala-Gln at 0.5, 2 and 5 mM dose-dependently reduced H2O2- or LPS-induced cell death by 14, 54 and 95%, respectively, whereas d-glutamine, alanine, glutamate, ornithine, proline, glucosamine or nucleosides had no effect. To evaluate the effectiveness of Gln or Ala-Gln in vivo, 7-day-old piglets received one-week oral administration of Gln or Ala-Gln (3.42 mmol/kg body weight) twice daily and then a single intraperitoneal injection of LPS (0.1 mg/kg body weight); piglets were euthanized in 24 and 48 h to analyze intestinal apoptotic proteins and morphology. Administration of Gln or Ala-Gln to LPS-challenged piglets increased Gln concentrations in small-intestinal lumen and plasma, reduced intestinal expression of Toll-like receptor-4, active caspase-3 and NFkB, ameliorated intestinal injury, decreased rectal temperature, and enhanced growth performance. These results demonstrate a protective effect of Gln or Ala-Gln against H2O2- or LPS-induced enterocyte death. The findings support addition of Gln or Ala-Gln to current Gln-free pediatric amino acid solutions to prevent intestinal oxidative injury and inflammatory disease in neonates. [ABSTRACT FROM AUTHOR]

L-Arginine administration may be useful for the treatment of intrauterine growth restriction, but concerns remain about effective precursors for administration into pregnant dams. Therefore, we used an ovine model to test the hypothesis that infusion of L-citrulline into the maternal circulation increases L-arginine availability to the fetus. On d 135 ± 1 of gestation, ewes received an i.v. bolus dose of L-citrulline (155 μmol/kg body weight) or the same dose of L-arginine-HCI. Maternal and fetal arterial blood samples were obtained simultaneously at -120, -60, 0, 5, 15, 30, 60, 120, 180, and 240 min relative to the time of amino acid administration. Concentrations of arginine in maternal plasma increased to peak values within 5 min after its injection in ewes and declined rapidly thereafter, whereas concentrations of arginine in fetal plasma increased between 15 and 30 min and returned to baseline values by 60 min. In contrast, administration of citrulline increased concentrations of citrulline and arginine in maternal and fetal plasma between 5 and 60 min and values remained elevated thereafter. The differential pharmacokinetics for arginine compared with citrulline infusion was consistent with the observation that the half-life of citrulline was twice that of arginine in ewes. We conclude that i.v. administration of citrulline is more effective than arginine in sustaining high concentrations of argmnine in the maternal and fetal circulations of pregnant ewes. These novel findings provide support for studies of the clinical use of arginine and citrulline as therapeutic means to prevent or ameliorate fetal growth retardation in mammals. [ABSTRACT FROM AUTHOR]

Dietary supplementation of glutamine prevents intestinal dysfunction and atrophy in weanling piglets, but the underlying mechanism(s) are largely unknown. This study was conducted to test the hypothesis that weaning or glutamine may modulate expression of genes that are crucial for intestinal metabolism and function. In Expt. 1, we obtained small intestine from 28-d-old pigs weaned at 21 d of age and from age-matched suckling piglets. In Expt. 2, piglets were weaned at 21 d of age and then had free access to diets supplemented with 1% L-glutamine (wt:wt) or isonitrogenous L-alanine (control). At d 28, we collected small intestine for biochemical and morphological measurements and microarray analysis of gene expression using the Operon Porcine Genome Oligo set. Early weaning resulted in increased (52-346%) expression of genes related to oxidative stress and immune activation but decreased l35-77%l expression of genes related to macronutrient metabolism and cell proliferation in the gut. Dietary glutamine supplementation increased intestinal expression (120-124%) of genes that are necessary for cell growth and removal of oxidants, while reducing (34-75%) expression of genes that promote oxidative stress and immune activation. Functionally, the glutamine treatment enhanced intestinal oxidative-defense capacity (indicated by a 29% increase in glutathione concentration), prevented jejunal atrophy, and promoted small intestine growth (+ 12%) and body weight gain (+ 19%) in weaned piglets. These findings reveal coordinate alterations of gene expression in response to weaning and aid in providing molecular mechanisms for the beneficial effect of dietary glutamine supplementation to improve nutrition status in young mammals. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the mechanism for the effect of elevated levels of dietary zinc oxide (ZnO) in enhancing the intestinal growth of weanling piglets. In. Experiment 1, 4-wk-old (8.1 ± 0.6 kg) crossbred barrows (n = 36) were assigned randomly to 1 of the 2 dietary groups, with 6 pens/group (3 pigs/pen). One group was fed the basal diet containing 100 mg Zn/kg diet. The other group was fed the basal diet supplemented with ZnO to provide 3000mg Zn/kg diet. Pigs consumed their feed ad libitum for 14 d. In Experiment 2, 4-wk-old (7.6 ± 0.16 kg) crossbred barrows (n = 16) were housed individually and assigned to 1 of the 2 dietary groups (8 pigs/group) as in Experiment 1, except that the 2 groups were pair-fed the same amount of feed. At the end of a 1 4-d treatment period, all of the pigs in both Experiments 1 and 2 were weighed, feed consumption was measured, and blood samples were collected for assays of insulin-like growth factor-I (IGF-I). In addition, 1 pig from each pen in Experiments 1 and 2 was selected randomly to obtain the small-intestinal mucosa for analyzing IGF-I and IGF-l receptor (IGF-IR) gene expression and to determine the small-intestinal morphology. In Experiment 1, dietary supplementation of ZnO increased (P < 0.05) the daily body weight gain and daily feed intake. In Experiment 2, dietary supplementation of ZnO increased (P < 0.05) the daily body weight gain and feed conversion efficiency. In both experiments, the villous height of the small-intestinal mucosa and both the mRNA and protein levels for IGF-l and IGF-IR in the small intestine were markedly enhanced (P < 0.05) by feeding elevated levels of Zn. Serum IGF-I levels did not differ between the control and Zn-supplemental groups in either experiment. Collectively, these results suggest that dietary Zn supplementation exerts its beneficial effects on the intestinal growth of weanling piglets through increasing IGF-l and IGF-IR expression in the small-intestinal mucosa. [ABSTRACT FROM AUTHOR]

Ovulation in the Bactrian camel depends upon ovulation-inducing factors in the seminal plasma. The present study was conducted to isolate and purify the bioactive fractions from the seminal plasma of these camels. The seminal plasma was fractionated by anion-exchange chromatography, and six fractions were obtained. The bioactive potential of each fraction was estimated from its effect on rat pituitary tissue cultured in vitro and by the effect of an intramuscular injection of the fraction into female camels in vivo. Both the third fraction (F3) and the fifth fraction (F5) stimulated the release of LH in vitro and in vivo. In addition, female camels ovulated within 48 h after intramuscular injection of F3. However, neither F3 nor F5 had any significant effect on the secretion of FSH, either in vitro or in vivo. When F3 was further fractionated into four subfractions, the third subfraction (F3-3) still stimulated the in vitro release of LH, but not of FSH. An attempt to further purify the ovulation-inducing factors in F3-3 failed owing to the similarity of the molecular characters. [ABSTRACT FROM AUTHOR]

Mutations of the dystrophin gene cause Duchenne muscular dystrophy, but the pathogenetic mechanisms are poorly understood. We previously reported that dystrophin-deficient muscles are susceptible to ischemia during exercise. Reactive oxygen species (ROS) produced during reperfusion of ischemic muscle can cause tissue injury. Because dystrophin-deficient muscle is abnormally sensitive to ROS, we hypothesized that ischemia-reperfusion (I/R) injury would be enhanced in dystrophin-deficient muscles of mdx mice, and that this damage would be ameliorated by antioxidant treatment. Anesthetized mdx and C57BL10 mice were subjected to 1 h of unilateral hindlimb ischemia followed by 2 h of reperfusion. Sarcolemmal damage following I/R was enhanced in mdx vs C57BL10 mice as shown by greater increases in serum creatine kinase (+2775±260 vs +1136±211 U/L; P<0.05) and in Evans blue dye (EBD) uptake by muscle (EBD+ area: 31±6 vs 8±3% of plantaris; 27±5 vs 3±1% of soleus; P<0.05). Infusion of the superoxide dismutase mimetic tempol (172 mg/kg, iv) attenuated EBD uptake by 63% in plantaris and by 31% in soleus muscles (P<0.05 vs I/R alone) of mdx mice, but had no effect in C57BL10 mice. These data demonstrate that the hindlimb muscles of mdx mice are abnormally susceptible to I/R-induced injury, and suggest that ROS production is a key event mediating sarcolemmal damage in dystrophin-deficient muscle. [ABSTRACT FROM AUTHOR]