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Ammonia nitrogen is a common environmental factor in aquaculture systems. High levels of ammonia nitrogen threaten the health of shrimp. This study aimed to investigate ammonia nitrogen stress in the hepatopancreas of Penaeus vannamei by integrating physiological, metabolome, and transcriptome analysis. The study revealed that exposure to ammonia nitrogen resulted in injury to the hepatopancreas, deformation disorder of the lumen, blurred boundaries, and increased vacuoles. After ammonia nitrogen stress, the activities of ammonia-metabolizing enzymes (glutamate dehydrogenase and glutamine synthetase) increased significantly, while the activity of transglutaminase decreased significantly. In addition, antioxidant enzymes (glutathione peroxidase, catalase, and superoxide dismutase) were significantly decreased. Additionally, the activity of energy metabolizing enzyme (hexokinase) was increased, and immune enzyme (alkaline phosphatase) activity was decreased. The accumulation of metabolites, such as d-myo-inositol, hexadecenoic acid, aspartate, and ornithine in the metabolite groups, showed significant differences under ammonia stress. Transcriptome analysis suggested that the KEGG pathways were significantly enriched in energy and primary metabolism, metabolism of cofactors and vitamins, and signaling pathways. The comprehensive analysis of metabolome and transcriptome displayed significant enrichment pathways, including TCA cycle, purine metabolism, pyrimidine metabolism, and folic acid biosynthesis under ammonia nitrogen stress. Simultaneously, six genes were found to respond to ammonia stress, including inositol oxygenase-like, histone h1-β, postembryonic, blood cell protein-glutamine-glutamyltransferase-like, receptor tyrosine protein phosphatase T-like, trichohyalin-like, and thyroxine 5-deiodinase-like. The results showed that ammonia nitrogen stress caused hepatopancreas tissue damage, changed in enzyme activities, metabolic process, and related gene expression in P. vannamei. [ABSTRACT FROM AUTHOR]

Yeasts are attractive hosts for the production of heterologous products due to their genetic tractability and relative ease of growth. While the baker's yeast Saccharomyces cerevisiae is a powerful workhorse of the biotechnology industry, the species has metabolic limitations and it is critical that we develop alternative platforms that will facilitate the development of bioprocesses that rely on sustainable feedstocks. In this study, we used synthetic biology tools to construct coumaric acid–producing strains of Kluyveromyces marxianus, a yeast whose physiological traits render it attractive for biotechnology applications. Coumaric acid is a building block in the synthesis of many different families of aromatics and is a key precursor for the synthesis of complect phenylpropanoid molecules, including many flavours and aromas. The starting point for this work was a K. marxianus chassis strain that has increased flux towards the synthesis of tyrosine and phenylalanine, the aromatic amino acids that can serve as starting points for coumaric acid synthesis. Following principles of synthetic biology, a modular approach was taken to identify the best solution to different metabolic possibilities and these were then combined in different ways. For the first step, it was established that the route from phenylalanine was superior to that from tyrosine and the combined overexpression of PlPAL , AtC4H and AtCPR1 delivered the highest yield of coumaric acid. Next, it was established that while Pdc5 and Aro10 both had phenylpyruvate decarboxylase activity, inactivation of ARO10 was sufficient to prevent flux loss in the pathway. Since phenylalanine is the starting point, efforts were made to improve efficiency of its production. It was found that glutamate was a preferred nitrogen source for coumaric acid production, and this knowledge was used to engineer a strain that overexpressed S. cerevisiae GDH1 and delivered higher yields of coumaric acid. Ultimately, this strategy led to the development of strains that has yields of up to 48 mg coumaric acid /g glucose. Strains were evaluated in bioreactors to investigate the effects of different process parameters. These analyses indicated that engineered strains face some redox balance challenges and further work will be required overcome these to develop strains that can perform well under industrial conditions. • The yeast Kluyveromyces marxianus was engineered to produce the aromatic precursor molecule coumaric acid. • The highest yield obtained was 48 mg coumaric acid per g glucose. • Engineering the GS/GOGAT pathway to increase intracellular glutamate increased coumaric acid titres. [ABSTRACT FROM AUTHOR]

Premium-tasty japonica rice, distinguished by its unique flavor and enriched nutritional value, has attracted significant attention across Asia. Nitrogen metabolism plays a crucial role in determining the growth, development, and quality of rice grains. This study investigates the effects of nitrogen application rates on the enzymatic activities related to nitrogen metabolism, nitrogen metabolites, and grain protein content in the premium-tasty japonica rice variety, Suxiangjing 100. Using a range of nitrogen application rates (0, 80, 160, 240, 320, and 400 kg per hectare), comprehensive analyses were conducted across various developmental stages. Results indicate that as nitrogen application increased, there were distinct patterns in the enzyme activities and metabolite concentrations related to nitrogen metabolism in the leaves of premium-tasty japonica rice. The activities of nitrate reductase (NR), glutamine synthetase (GS), and glutamate synthase (GOGAT) peaked at moderate nitrogen applications, while excessive nitrogen led to a decrease in their activities. The activity of Glutamate Dehydrogenase (GDH) generally increased, but showed a decline after the filling stage. With increasing nitrogen application, the concentrations of nitrate nitrogen (NO3–N), ammonium nitrogen (NH4–N), free amino acids (FAA), and soluble proteins (SP) initially rose but declined at excessive application rates. The grain protein content increased, with levels of prolamin, glutelin, and globulin peaking at nitrogen applications of 240 kg/ha and 320 kg/ha, while changes in albumin levels were minimal. This study not only provides novel insights into the role of nitrogen in shaping the growth and quality of premium-tasty japonica rice, but also suggests refined nitrogen management strategies for sustainable agricultural practices. [ABSTRACT FROM AUTHOR]

The article pays tribute to the late Professor Peter J. Lea, a renowned scientist and Emeritus Professor at Lancaster University. Professor Lea's research focused on nitrogen assimilation in plants, contributing significantly to crop improvement and nitrogen metabolism. He was also involved in various activities, such as serving as President of the Association of Applied Biologists and mentoring students and scientists. His impactful work and collaborations have left a lasting legacy in the field of plant science. [Extracted from the article]

The objectives of this study were to identify factors associated with prepartum DMI, evaluate the performance of linear models to estimate prepartum DMI using different classes of predictors, and investigate the consequences of different levels of prepartum DMI on transition metabolism and lactation performance. Individual feed intake of nulliparous (n = 100) and parous cows (n = 173) was measured by automatic feeding bins from d −35 to 98 relative to calving. Rumination and physical activities were monitored by wearable sensors. Blood metabolites were measured on d −21, −10, −3, 0, 3, 7, 10, 14, and 21. Body weight and BCS were assessed throughout the study. The average prepartum DMI as percentage of BW (DMIpBW) was calculated for each cow and used as dependent variable of linear models. Parity, prepartum BCS and BW, 305-d milk production in the previous lactation, milk yield at dry-off (MYDO), and the length of the dry period were associated with DMIpBW. These factors explained 41% of the variation in DMIpBW across all cows and 49% in parous cows.. Estimations of DMIpBW were improved when data on prepartum rumination and blood metabolites were added into the predictive models. In the latter, the adjusted R2 increased to values between 47% and 61%, and selected models performed consistently in a 5-fold cross-validation analysis. To evaluate the implications of DMIpBW to transition metabolism and performance, cows were ranked within parity and classified into terciles as low (LFI), moderate (MFI), or high feed intake (HFI). The mean DMI was 1.44%, 1.70%, and 1.91% ± 0.01% of BW, respectively. No differences in BW were observed in nulliparous cows, but all 3 groups of parous cows differed (LFI = 892, MFI = 849, HFI = 798 ± 8 kg). The proportion of cows with BCS >3.5 at enrollment differed among all groups, and averaged 67.4%, 55.1%, and 36.5% ± 6%, respectively. For parous cows, 305-d milk production and MYDO differed among all groups and averaged 9,808, 10,457, and 11,182 ± 233 kg, and 18.1, 23.1, and 26.2 ± 1 kg/d, respectively. After calving, DMI (LFI = 20.9, MFI = 21.9, and HFI = 22.1 ± 0.2 kg/d) and milk yield (LFI = 36.7, MFI = 38.2, and HFI = 38.3 ± 0.4 kg/d) was lower in LFI cows compared with the other 2 groups. Postpartum energy balance differed among all groups and averaged −2.79, −1.63, and −0.66 ± 0.3 Mcal/d for LFI, MFI, and HFI, respectively. During the transition period, LFI cows had higher serum concentrations of nonesterified fatty acids, BHB, Cl (prepartum only), and aspartate aminotransferase (AST; postpartum only), and lower serum concentrations of cholesterol, P, glutamate dehydrogenase, gamma-glutamyl transferase (prepartum only), AST (prepartum only), urea (parous only), and superoxide dismutase activity (parous only). In conclusion, a low level of prepartum DMI was associated with fatter and heavier cows, lower milk production in previous lactation, important adjustments in energy metabolism during the transition period, and moderate losses in DMI and milk yield in the subsequent lactation. Moreover, the inclusion of prepartum rumination activity and target blood metabolites into predictive models improved the estimations of prepartum DMI. The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. [ABSTRACT FROM AUTHOR]

Renal fibrosis is the common outcome of practically all progressive forms of chronic kidney disease (CKD), a significant societal health concern. Glutamate dehydrogenase (GDH) 1 is one of key enzymes in glutamine metabolism to catalyze the reversible conversion of glutamate to α‐ketoglutarate and ammonia. However, its function in renal fibrosis has not yet been proven. In this study, GDH1 expression was significantly downregulated in kidney tissues of both children with kidney disease and animal models of CKD. In vivo, the use of R162 (a GDH1 inhibitor) significantly improved renal fibrosis, as indicated by Sirius red and Masson trichrome staining. These findings are consistent with the impaired expression of fibrosis indicators in kidneys from both the unilateral ureteral obstruction (UUO) and 5/6 nephrectomy (5/6 Nx) models. In vitro, silencing GDH1 or pretreatment with R162 inhibited the induction of fibrosis indicators in tissue kidney proximal tubular cells (TKPTS) treated with Transforming growth factor Beta 1 (TGF‐β1), whereas activating GDH1 worsened TGF‐β1's induction impact. Using RNA‐sequence, luciferase reporter assays and Biacore analysis, we demonstrated that GDH1 interacts with Peroxisome proliferator‐activated receptor gamma (PPARγ) and blocks its transcriptional activity, independent of the protein's expression. Additionally, R162 treatment boosted PPARγ transcriptional activity, and blocking of this signaling pathway reversed R162's protective effect. Finally, we discovered that R162 treatment or silencing GDH1 greatly lowered reactive oxygen species (ROS) and lipid accumulation. These findings concluded that suppressing GDH1 or R162 treatment could prevent renal fibrosis by augmenting PPARγ transcriptional activity to control lipid accumulation and redox balance. [ABSTRACT FROM AUTHOR]

Mainly performed within a rapid diagnostic tests company, a lateral flow (LF) system using gold nanoparticles (AuNPs) as transducers is presented able to detect three bacteria of interest, of relevance for antimicrobial resistance (AMR): Clostridioides difficile, methicillin-resistant Staphylococcus aureus (MRSA), and Klebsiella pneumoniae, with a limit of detection of 25 ng/mL of glutamate dehydrogenase (GDH) for C. difficile, 36 ng/mL of penicillin-binding protein 2a (PBP2a) for MRSA, and 4 × 106 CFU/mL for K. pneumoniae. The system showed good results with bacteria culture samples, is user-friendly, and suitable for rapid testing, as the results are obtained within 15 min. [ABSTRACT FROM AUTHOR]

Glutamate dehydrogenase (GDH) participates in the energy metabolism of proteins and the synthesis of metabolites important for the organism. In this study, GDH enzyme was purified from the liver of rainbow trout (Oncorhynchus mykiss) by 2',5'‐ADP Sepharose 4B affinity chromatography in one step. As a result of this purification process, GDH enzyme was purified 171‐fold with 5.83 U/mg protein‐specific activity. The characterization experiments presented that the storage stability of the purified GDH enzyme was determined as −80°C; optimum temperature 40°C; it was determined that the optimum ionic strength was 100 mM phosphate buffer and the optimum pH was 8.00. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE) and PAGE studies showed that the natural molar mass of the purified GDH enzyme was 346.74 kDa, and the molar mass of its subunits was 53.71 kDa. Km and Vmax values for substrates and coenzymes of GDH enzyme purified from rainbow trout liver were calculated, and the lowest Km value was found in NAD+ (1.86 mM) and the highest Vmax value in NH4+ (1.79 U/mL). The effects of some metal ions, vitamins, and solvents on the activity of the purified GDH enzyme were investigated and also IC50 values and inhibition types. The metal ion with the lowest IC50 value is Ag+ (8.65 ± 1.68 μM), and the vitamin is B6 (0.77 ± 0.04 mM). The binding affinities of inhibitors were investigated with molecular docking, based on the conformational state of GDH. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. Bile acids are cholesterol-derived molecules that are primarily produced in the liver. In nonruminants with fatty liver, overproduction of bile acids is associated with liver injury. During the transition period, fatty liver is a metabolic disorder that can affect up to 50% of high-producing dairy cows. The purpose of this study was to provide a comprehensive evaluation of hepatic bile acid metabolism in dairy cows with fatty liver by assessing the expression changes of genes involved in bile acid synthesis, export, and uptake. The serum activities of aspartate aminotransferase, alanine aminotransferase, and glutamate dehydrogenase and the concentration of total bile acids were all greater, whereas the serum concentration of total cholesterol was lower in cows with fatty liver than in healthy cows. The content of total bile acids was higher, but total cholesterol was slightly lower in liver tissues from fatty liver cows than from healthy cows. The hepatic mRNA abundance of cholesterol 7a-hydroxylase (CYP7A1); hydroxy-delta-5-steroid dehydrogenase, 3 β- and steroid delta-isomerase 7 (HSD3B7); and sterol 12α-hydroxylase (CYP8B1), enzymes involved in the classic pathway of bile acid synthesis, was higher in fatty liver cows than in healthy cows. Compared with healthy cows, the hepatic mRNA abundance of alternative bile acid synthesis pathway-related genes sterol 27-hydroxylase (CYP27A1) and oxysterol 7α-hydroxylase (CYP7B1) did not differ in cows with fatty liver. The protein and mRNA abundances of bile acid transporter bile salt efflux pump (BSEP) were lower in the liver of dairy cow with fatty liver. Compared with healthy cows, the hepatic mRNA abundance of bile acid transporters solute carrier family 51 subunit α (SLC51A) and ATP binding cassette subfamily C member 1 (ABCC1) and 3 (ABCC3) was greater in cows with fatty liver, whereas the solute carrier family 51 subunit β (SLC51B) did not differ. The expression of genes involved in bile acid uptake, including solute carrier family 10 member 1 (NTCP), solute carrier organic anion transporter family member 1A2 (SLCO1A2) and 2B1 (SLCO2B1) was upregulated in dairy cows with fatty liver. Furthermore, the hepatic protein and mRNA abundance of bile acid metabolism regulators farnesoid X receptor (FXR) and small heterodimer partner (SHP) were lower in cows with fatty liver than in healthy cows. Overall, these data suggest that inhibition of the FXR signaling pathway may lead to increased bile acid synthesis and uptake and decreased secretion of bile acids from hepatocytes to the bile, which elevates hepatic bile acid content in dairy cows with fatty liver. Because the hepatotoxicity of bile acids has been demonstrated on nonruminant hepatocytes, it is likely that liver injury is induced by increased hepatic bile acid content in dairy cows with fatty liver. [ABSTRACT FROM AUTHOR]

Leishmaniasis is a complex vector-borne disease caused by intracellular protozoan parasites of the Leishmania genus. It presents a significant public health challenge in tropical and subtropical regions globally. As resistance to treatment increases, managing and controlling Leishmaniasis becomes more challenging, necessitating innovative approaches. To address this challenge, our study utilized subtractive genomics and structure-based approaches to identify common drug targets and combat antimicrobial resistance (AMR) across five Leishmania species strains. The subtractive genomics approach unraveled Glutamate Dehydrogenase (GDH) as a promising drug target for treating Leishmania infections. The investigation considered established methodologies observed in analogous studies, orthologous group, and druggability tests. Multiple sequence alignment revealed conserved sequences in GDH, while phylogenetic tree analysis provided insights into the evolutionary origin and close relationships of GDH across Leishmania species. Conserved sequences in GDH along with its function in pathogenicity provided insights into the close relationships of GDH across Leishmania species. Using a structure-based approach, our study showed the molecular interactions between GDH and three ligands—Bithionol, GW5074, and Hexachlorophene—through molecular docking and 100 ns molecular dynamics (MD) simulations. GW5074 exhibited a significant affinity for GDH, as indicated by stable RMSD values, a more compact conformation, and a higher number of hydrogen bonds than Bithionol. MMPBSA analysis confirmed the superior binding energy of the GW5074-GDH complex, emphasizing its potential as a potent ligand for drug development. This comprehensive analysis identified GW5074 as a promising candidate for inhibiting GDH activities in Leishmania species, contributing to the development of effective therapeutics against Leishmania infections. [ABSTRACT FROM AUTHOR]

An increase in GDH activity has been established in the first six hours after plants are exposed to hypoxic conditions, which ensures the formation of an adaptive response of cellular metabolism to the lack of oxygen in the cell. A difference in the transcriptional activity of homologous GDH-1 genes in wheat leaves under stress conditions was shown. An increase in the mRNA content of the GDH-1(5A) gene in wheat leaves after plants are exposed to hypoxic conditions is observed in the first hours of the experiment, which correlates with a change in the catalytic activity of glutamate dehydrogenase. Regulation of this gene is carried out by the transcription factor HIF, the specific landing site of which is found in the transcription initiation site of the promoter of this gene. [ABSTRACT FROM AUTHOR]

This study investigates the impact of various molecular weights (MWs) of fulvic acid (FA) on maize growth, grain yield, and nutrient uptake under different nitrogen levels (NLs). A 2 × 3 balanced design was employed, with high (0.2 g N/kg) and low (0.05 g N/kg) NLs, and three FA MW ranges (W1 = 3 000 D, 3 000 < W2 = 10 000 D, W3 > 10 000 D) were applied at 25 mg/kg in soil. Significant interactions between NLs and FA MWs were observed in chlorophyll a/b ratio, nitrate reductase and glutamate dehydrogenase activities, nitrogen content, and nitrogen uptake efficiency. Overall, under different NLs, FA application reduced chlorophyll a/b ratio, increased nitrogen metabolism enzyme activities, promoted maize growth, and thereby improved grain yield and nitrogen fertiliser uptake efficiency. Additionally, the promotion effect of low MW FA on these indicators outweighed that of high MW FA, yet the latter exhibited a more pronounced effect on increasing grain nitrogen concentration. Structural equation model analysis revealed direct effects of chlorophyll content, nitrogen accumulation, nitrogen uptake efficiency, NLs and FA MWs on maize grain yield, with FA MWs negatively impacting yield. [ABSTRACT FROM AUTHOR]

Yellowing is the first visually observable sign of plant leaf senescence. We found that Arabidopsis double knockout mutant gdh1gdh2 for genes of NAD(H)-dependent glutamate dehydrogenase retains green color of the leaves (stay-green phenotype) during a dark-induced senescence, in contrast to wild-type plants, whose leaves turn yellow. When the gdh1gdh2 plants are exposed to the dark more than four days, they demonstrate slower chlorophyll degradation than in the wild-type plants under the same conditions, as well as dysregulation of chlorophyll breakdown genes encoding chlorophyll b reductase, Mg-dechelatase, pheophytinase and pheophorbide a oxygenase. The slowed degradation of chlorophyll b in gdh1gdh2 plants significantly alters the chlorophyll a/b ratio. Ion leakage in the mutant plants increases significantly from four to eight days in the darkness, correlating with their premature death during this period. The discovered facts suggest a functional connection between activity of NAD(H)-dependent glutamate dehydrogenase and dark-induced senescence progress in Arabidopsis. [ABSTRACT FROM AUTHOR]

Introduction: Clostridioides difficile (C. difficile), once considered a nosocomial pathogen, is now increasingly being observed in the community. The organism is known to cause Antibiotic-associated Diarrhoea (AAD), Pseudomembranous Colitis (PMC), megacolon, and even death. Aim: To determine the prevalence of C. difficile in stool samples and to associate the findings with the clinical presentation and risk factors of the patients. Materials and Methods: This retrospective cross-sectional study analysed 208 stool samples received for C. difficile detection at Father Muller Medical College Hospital, Mangaluru, Karnataka, India from January 2021 to January 2023 using the CerTest C. difficile Glutamate dehydrogenase (GDH)+ Toxin A+B onestep combo card test. The results were then associated with the clinical profiles of the patients retrieved from the hospital software, Backbone. Statistical analysis was performed using frequency, percentage, the Chi-square test, and the z-test. Results: Out of the 208 samples analysed from patients belonging to all ages, 20 samples (9.62%) harboured toxigenic C. difficile, while 22 samples (10.58%) contained non toxigenic C. difficile. Proton Pump Inhibitor (PPI) use and underlying diseases/conditions were identified as highly significant risk factors (χ2=32.28, p-value

Root-associated fungal endophytes may facilitate nitrogen (N) absorption in plants, leading to benefits in photosynthesis and growth. Here, we investigated whether endophytic insect pathogenic fungi (EIPF) are capable of transferring soil N to the crop species Chenopodium quinoa. We evaluated nutrient uptake, carbon allocation, and morpho-physiological performance in C. quinoa in symbiosis with two different EIPF (Beauveria and Metarhizium) under contrasting soil N supply. A controlled experiment was conducted using two plant groups: (1) plants subjected to low N level (5 mM urea) and (2) plants subjected to high N level (15 mM urea). Plants from each group were then inoculated with different EIPF strains, either Beauveria (EIPF1+), Metarhizium (EIPF2+) or without fungus (EIPF-). Differences in N and C content, amino acids, proteins, soluble sugars, starch, glutamine synthetase, glutamate dehydrogenase, and physiological (photosynthesis, stomatal conductance, transpiration), and morphological performance between plant groups under each treatment were examined. We found that both Beauveria and Metarhizium translocated N from the soil to the roots of C. quinoa, with positive effects on photosynthesis and plant growth. These effects, however, were differentially affected by fungal strain as well as by N level. Additionally, an improvement in root C and sugar content was observed in presence of EIPF, suggesting translocation of carbohydrates from leaves to roots. Whereas both strains were equally effective in N transfer to roots, Beauveria seemed to exert less demand in C. quinoa for photosynthesis-derived carbohydrates compared to Metarhizium. Our study revealed positive effects of EIPF on N transfer and morpho-physiological performance in crops, highlighting the potential of these fungi as an alternative to chemical fertilizers in agriculture systems. [ABSTRACT FROM AUTHOR]

The effect of salt stress (150 mM NaCl) on the expression of genes, methylation of their promoters, and enzymatic activity of glutamate dehydrogenase (GDH), glutamate decarboxylase (GAD), and the 2-oxoglutarate (2-OG)–dehydrogenase (2-OGDH) complex was studied in maize (Zea mays L.). GDH activity increased continuously under salt stress, being 3-fold higher after 24 h. This was accompanied by the appearance of a second isoform with lower electrophoretic mobility. The expression of the Gdh1 gene strongly increased after 6–12 h of incubation, which corresponded to the demethylation of its promoter, while Gdh2 gene expression slightly increased after 2–6 h and then decreased. GAD activity gradually increased in the first 12 h, and then returned to the control level. This corresponded to the increase of Gad expression and its demethylation. Salt stress led to a 2-fold increase in the activity of 2-OGDH during the first 6 h of NaCl treatment, then the activity returned to the control level. Expression of the genes Ogdh1 and Ogdh3 peaked after 1–2 h of incubation. After 6–8 h with NaCl, the expression of these genes declined below the control levels, which correlated with the higher methylation of their promoters. We conclude that salt stress causes a redirection of the 2-OG flux to the γ-aminobutyric acid shunt via its amination to glutamate, by altering the expression of the Gdh1 and Gdh2 genes, which likely promotes the assembly of the native GDH molecule having a different subunit composition and greater affinity for 2-OG. [ABSTRACT FROM AUTHOR]

The domestication of crops, coupled with agroecosystem development, is associated with major environmental changes and provides an ideal model of phenotypic plasticity. Here, we examined 32 genotypes of three tetraploid wheat (Triticum turgidum L.) subspecies, wild emmer, emmer, and durum wheat, which are representative of the key stages in the domestication of tetraploid wheat. We developed a pipeline that integrates RNA-Seq data and population genomics to assess gene expression plasticity and identify selection signatures under diverse nitrogen availability conditions. Our analysis revealed differing gene expression responses to nitrogen availability across primary (wild emmer to emmer) and secondary (emmer to durum wheat) domestication. Notably, nitrogen triggered the expression of twice as many genes in durum wheat compared to that in emmer and wild emmer. Unique selection signatures were identified at each stage: primary domestication mainly influenced genes related to biotic interactions, whereas secondary domestication affected genes related to amino acid metabolism, in particular lysine. Selection signatures were found in differentially expressed genes (DEGs), notably those associated with nitrogen metabolism, such as the gene encoding glutamate dehydrogenase (GDH). Overall, our study highlights the pivotal role of nitrogen availability in the domestication and adaptive responses of a major food crop, with varying effects across different traits and growth conditions. Nitrogen had a pivotal role in tetraploid wheat domestication and adaptive responses, leading to diverse impacts on gene expression and selection signatures during primary and secondary domestication. [ABSTRACT FROM AUTHOR]

Bilirubin (BR) is an important ingredient of a valuable Chinese medicine, Calculus bovis. Over recent decades, increasing evidence has confirmed that BR offers health benefits in cardiovascular health, stroke, diabetes, and metabolic syndrome. However, BR is mainly produced by extraction from pig bile. In this study, we assembled an efficient pathway for BR production by metabolic engineering of Escherichia coli. First, heme oxygenase (HO1) and biliverdin reductase were co-expressed in E. coli. HPLC and LC–MS confirmed the accumulation of BR in the recombinant E. coli cells. To improve BR production, the catalytic abilities of HO1 from different species were investigated. In addition, the outermembrane-bound heme receptor (ChuA) and the enzymes involved in heme biosynthesis were overexpressed among which ChuA, 5-aminolevulinic acid dehydratase (HemB), protoporphyrin oxidase (HemG), and ferrochelatase (HemH) were found to enhance BR accumulation in E. coli. In addition, expression of ferredoxin (Fd) was shown to contribute to efficient conversion of heme to BR in E. coli. To increase supply of NADPH, isocitrate dehydrogenase (IDH), NAD kinase (nadK), NADP-specific glutamate dehydrogenase (gdhA), and glucose-6-phosphate 1-dehydrogenase (ZWF) were overexpressed and were found to enhance BR accumulation when these proteins were expressed with a low-copy plasmid pACYCduet-1. Modular optimization of the committed genes led to a titer of 17.2 mg/L in strain M1BHG. Finally, fed-batch fermentation was performed for the strains M1BHG and M1, resulting in accumulation of 75.5 mg/L and 25.8 mg/L of BR, respectively. This is the first report on biosynthesis of BR through metabolic engineering in a heterologous host. [ABSTRACT FROM AUTHOR]

Regional citrate anticoagulation (RCA) is a preferred method for continuous renal replacement therapy (CRRT) due to its benefits of extended filter lifespan and reduced bleeding complications. However, RCA can cause metabolic side effects such as alkalosis, acidosis, hypotension, and electrolyte imbalances. Optimal anticoagulation requires careful adjustment of citrate infusion based on blood flow rate. Citrate accumulation can occur in certain conditions, leading to adverse effects. Strategies for adapting citrate anticoagulation include adjusting the dose based on the patient's condition. The Cori cycle has been proposed as an alternative pathway for citrate metabolism outside the liver mitochondria. Establishing thresholds for citrate initiation is important, and lactate levels can be used as an indicator of impaired citrate metabolism. The proposed hypothesis of an alternative inducible citrate metabolism pathway requires further research, including an animal model, to validate its effectiveness. Overall, RCA is a viable option for patients with liver failure, and further research is needed to optimize its application and improve anticoagulation strategies in various clinical contexts. [Extracted from the article]

Glucagon is critical for the maintenance of blood glucose, however nutrient regulation of pancreatic α-cells remains poorly understood. Here, we identified a role of leucine, a well-known β-cell fuel, in the α-cell–intrinsic regulation of glucagon release. In islet perifusion assays, physiologic concentrations of leucine strongly inhibited alanine- and arginine-stimulated glucagon secretion from human and mouse islets under hypoglycemic conditions. Mechanistically, leucine dose-dependently reduced α-cell cAMP, independently of Ca2+, ATP/ADP, or fatty acid oxidation. Leucine also reduced α-cell cAMP in islets treated with somatostatin receptor 2 antagonists or diazoxide, compounds that limit paracrine signaling from β/δ-cells. Studies in dispersed mouse islets confirmed an α-cell–intrinsic effect. The inhibitory effect of leucine on cAMP was mimicked by glucose, α-ketoisocaproate, succinate, and the glutamate dehydrogenase activator BCH and blocked by cyanide, indicating a mechanism dependent on mitochondrial metabolism. Glucose dose-dependently reduced the impact of leucine on α-cell cAMP, indicating an overlap in function; however, leucine was still effective at suppressing glucagon secretion in the presence of elevated glucose, amino acids, and the incretin GIP. Taken together, these findings show that leucine plays an intrinsic role in limiting the α-cell secretory tone across the physiologic range of glucose levels, complementing the inhibitory paracrine actions of β/δ-cells. Article Highlights: Despite the critical role of pancreatic islets as nutrient sensors, the mechanisms by which amino acids regulate glucagon release remain incompletely understood. We show that leucine, a well-known β-cell fuel, regulates glucagon secretion via a combination of α-cell–intrinsic and islet paracrine signaling. Leucine intrinsically suppresses α-cell cAMP, independently of α-cell Ca2+, ATP/ADP, or fatty acid oxidation. Our findings demonstrate complementary roles of leucine and glucose in the regulation of α-cell cAMP and glucagon secretion. [ABSTRACT FROM AUTHOR]

This study investigated the effects of exogenous nitric oxide (NO) on growth, antioxidant enzymes, and key nitrogen metabolism enzymes in pepper seedlings under high-temperature stress. In addition, targeted metabolomics was used to study the differential accumulation of amino acid metabolites, thereby providing theoretical support for the use of exogenous substances to mitigate high-temperature stress damage in plants. The results showed that high-temperature stress increased soluble sugar, soluble protein, amino acids, proline, malondialdehyde (MDA), and hydrogen peroxide (H2O2) content, electrolyte leakage, and superoxide anion (O2·-) production rate while altering the activities of antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX)] and key nitrogen metabolism enzymes [nitrate reductase (NR), glutamine synthetase (GS), glutamate dehydrogenase (GDH), and nitric oxide synthase (NOS)]. c-PTIO (2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide, an NO scavenger) exacerbates oxidative stress and further reduces NO content and enzyme activities. However, exogenous SNP (sodium nitroprusside, an NO donor) effectively alleviated these adverse effects by enhancing antioxidant defense mechanisms, increasing NO content, and normalizing amino acid metabolite levels (kynurenine, N-acetyl-L-tyrosine, L-methionine, urea, and creatine), thereby maintaining normal plant growth. These findings suggest that SNP can enhance stress tolerance in pepper seedlings by improving osmotic regulation, antioxidant capacity, and nitrogen metabolism, effectively mitigating the damage caused by high-temperature stress. [ABSTRACT FROM AUTHOR]

The proper functioning of neural circuits that integrate sensory signals is essential for individual adaptation to an ever-changing environment. Many molecules can modulate neuronal activity, including neurotransmitters, receptors, and even amino acids. Here, we ask whether amino acid transporters expressed by neurons can influence neuronal activity. We found that minidiscs (mnd), which encodes a light chain of a heterodimeric amino acid transporter, is expressed in different cell types of the adult Drosophila brain: in mushroom body neurons (MBs) and in glial cells. Using live calcium imaging, we found that MND expressed in α/β MB neurons is essential for sensitivity to the L-amino acids: Leu, Ile, Asp, Glu, Lys, Thr, and Arg. We found that the Target Of Rapamycin (TOR) pathway but not the Glutamate Dehydrogenase (GDH) pathway is involved in the Leucine-dependent response of α/β MB neurons. This study strongly supports the key role of MND in regulating MB activity in response to amino acids. [ABSTRACT FROM AUTHOR]

Liver injury with marked elevation of aspartate aminotransferase enzyme (AST) is commonly observed in dengue infection. To understand the pathogenesis of this liver damage, we compared the plasma levels of hepatic specific, centrilobular predominant enzymes (glutamate dehydrogenase, GLDH; glutathione S transferase-α, αGST), periportal enriched 4-hydroxyphenylpyruvate dioxygenase (HPPD), periportal predominant arginase-1 (ARG-1), and other non-specific biomarkers (paraoxonase-1, PON-1) in patients with different outcomes of dengue infection. This hospital-based study enrolled 87 adult dengue patients, stratified into three groups based on plasma AST levels (< 80, 80–400, > 400 U/L) in a 1:1:1 ratio (n = 40, n = 40, n = 40, respectively. The new liver enzymes in the blood samples from the 4th to 6th days of their illness were measured by commercial enzyme-linked immunosorbent assay (ELISA) or colorimetric kits. Based on the diagnosis at discharge days, our patients were classified as 40 (46%) dengue without warning signs (D), 35 (40.2%) dengue with warning signs (DWS), and 11 (12.6%) severe dengue (SD) with either shock (two patients) or AST level over 1000 U/L (nine patients), using the 2009 WHO classification. The group of high AST (> 400 U/L) also had higher ALT, GLDH, ARG-1, and HPPD than the other groups, while the high (> 400 U/L) and moderate (80–400 U/L) AST groups had higher ALT, αGST, ARG-1, and HPPD than the low AST group (< 80 U/L). There was a good correlation between AST, alanine aminotransferase enzyme (ALT), and the new liver biomarkers such as GLDH, αGST, ARG-1, and HPPD. Our findings suggest that dengue-induced liver damage initiates predominantly in the centrilobular area toward the portal area during the dengue progression. Moreover, these new biomarkers should be investigated further to explain the pathogenesis of dengue and to validate their prognostic utility. Key messages: Arginase-1, α-glutathione S transferase, and 4-hydroxyphenylpyruvate dioxygenase levels were significantly associated with dengue severity and can serve as good prognostic predictors for liver injury. Our findings suggest that dengue-induced liver damage initiates predominantly in the centrilobular area toward the portal area during the dengue progression. [ABSTRACT FROM AUTHOR]

Plasmodium falciparum malaria remains a dominant infectious disease that affects Africa than the rest of the world, considering its associated cases and death rates. It's a febrile illness that produces several reliable biomarkers, for example, P. falciparum lactate dehydrogenase (PfLDH), P. falciparum Plasmodium glutamate dehydrogenase (PfGDH), and P. falciparum histidine‐rich proteins (HRP‐II) in blood circulatory system that can easily be employed as targets in rapid diagnostic tests (RDTs). In recent times, several DNA aptamers have been developed via SELEX technology to detect some specific malaria biomarkers (PfLDH, PvLDH, HRP‐II, PfGDH) in a biosensor mode with good binding affinity properties to overcome the trend of cross‐reactivity, limited sensitivity and stability problems that have been observed with immunodiagnostics. In this review, we summarized existing diagnostic methods and relevant biomarkers to suggest promising approaches to develop sensitive and species‐specific multiplexed diagnostic devices enabling effective detection of malaria in complex biological matrices and surveillance in the endemic region. Significance statement: The focus of this review was to summarize research findings on the existing diagnostics approaches for malaria infection and the necessity for multiplex malaria detection using aptamer agents, biomarkers, and microfluidic technology. The World Health Organization had shown that malaria infection does not only lead to death, there are other complications such as low birthweight, growth retardation, poor cognitive function, and malnutrition in underage children (0−5 years). However, due to the lack of adequate medical facilities in the low‐middle income countries (LMIC) and low analytical performance of the existing biomedical devices, there is a need for medium to high throughput point‐of‐care devices to conduct routine surveillance by testing. Microfluidic technology is a facile and versatile approach to diagnostics that can be trialed to multiplex assay for malaria in the LMIC. [ABSTRACT FROM AUTHOR]

Downy mildew is one of the main diseases that cause a reduction in cucumber yield. Chemical control not only increases pathogenic bacteria resistance and causes environmental pollution but also endangers the health of humans as they are abundant pesticide residues in fruits. Dopamine, a strong antioxidant that widely exists in plants, can effectively protect plants from the adverse effects of such chemicals. In this study, the susceptible cucumber cultivar 'Changchun Mici' and the disease-resistant cultivar 'Jinchun No. 4' were used as test materials to explore the alleviating effect of exogenous dopamine on cucumber downy mildew. After downy mildew infection, exogenous dopamine (100 µmol L−1) had the greatest significant effect on improving the disease resistance of cucumber, increasing the activities of superoxide dismutase, catalase, peroxidase, and ascorbate peroxidase in cucumber, thereby reducing the accumulation of the superoxide anion and hydrogen peroxide in leaves, the content of malondialdehyde, and the relative electrical conductivity in leaves, which significantly improved the antioxidant capacity of cucumber. Simultaneously, exogenous dopamine increased the leaf wax content and trichome density; the activities of polyphenol oxidase, chitinase, and β-1,3-glucanase; and the expression of CsPR1, so that the disease index was significantly reduced. As for nitrogen metabolism, exogenous dopamine significantly increased the activities of nitrate reductase, glutamine synthase, glutamate synthase, and glutamate dehydrogenase, as well as the content of nitrate nitrogen, whereas it decreased the accumulation of ammonium nitrogen, thereby promoting nitrogen metabolism in cucumber. As a consequence, exogenous dopamine improved the yield and quality of cucumbers infected by downy mildew. [ABSTRACT FROM AUTHOR]

Fermentation with Bacillus subtilis significantly enhances the physiological activity and bioavailability of soymilk, but the resulting characteristic flavor seriously affects its industrial promotion. The objective of this study was to identify key proteins associated with characteristic flavors in B. subtilis BSNK-5-fermented soymilk using tandem mass tag (TMT) proteomics. The results showed that a total of 765 differentially expressed proteins were identified. Seventy differentially expressed proteins related to characteristic flavor were screened through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. After integrating metabolomics data, fifteen key proteases of characteristic flavor components in BSNK-5-fermented soymilk were further identified, and free ammonia was added. In addition, there were five main formation mechanisms, including the decomposition of urea to produce ammonia; the degradation of glutamate by glutamate dehydrogenase to produce ammonia; the degradation of threonine and non-enzymatic changes to form the derivative 2,5-dimethylpyrazine; the degradation of valine, leucine, and isoleucine to synthesize isovalerate and 2-methylbutyrate; and the metabolism of pyruvate and lactate to synthesize acetate. These results provide a theoretical foundation for the improvement of undesirable flavor in B. subtilis BSNK-5-fermented soy foods. [ABSTRACT FROM AUTHOR]

Soil acidification is a global environmental problem with significant impacts on agricultural production, environmental protection, and ecosystem health. Soil acidification is widespread in China, affecting crop yields, agricultural product quality, and biodiversity. Since the 1980s, much work has been done on acidic soils in China, but it is controversial whether excessive nitrogen fertilizer application can lead to soil acidification mechanisms. To address the above issues, we conducted a meta-analysis of 115 published papers to integrate and analyze the effects of N fertilizer application on soil acidification and biological properties from 1980 to 2024. We also quantified the effect of nitrogen fertilization on soil acidification and biological changes under different climatic conditions. The results showed that under long-term application of nitrogen fertilizers in China from 1980 to 2024, soil pH decreased by an average of 15.27%, and the activities of soil urease, nitrate reductase, nitrite reductase, catalase, glutamate dehydrogenase, and glutamate synthetase decreased by an average of 9.82–22.37%. The soil microbial community richness (Chao1 index) increased by 6.53%, but the community diversity (Shannon index) decreased by 15.42%. Among the dominant soil microorganisms, the relative abundance of bacteria decreased by an average of 9.67–29.38% and the abundance of gene expression of nifH, amoA-AOA, amoA-AOB, and qnorB decreased by 9.92–19.83%. In addition, we found that the mean annual temperature and rainfall impacted soil acidification via their effect on soil microbial diversity and community composition. This study provides a scientific basis for an in-depth understanding of the spatial and temporal variation of soil acidification and biological properties in China. [ABSTRACT FROM AUTHOR]

Background: The parasitic protozoan Giardia duodenalis is an important cause of diarrheal disease in humans and animals that can be spread by fecal–oral transmission through water and the environment, posing a challenge to public health and animal husbandry. Little is known about its impact on large-scale sheep farms in China. In this study we investigated G. duodenalis infection of sheep and contamination of the environment in large-scale sheep farms in two regions of China, Henan and Ningxia. Methods: A total of 528 fecal samples, 402 environmental samples and 30 water samples were collected from seven large-scale sheep farms, and 88 fecal samples and 13 environmental samples were collected from 12 backyard farms. The presence of G. duodenalis was detected by targeting the β-giardin (bg) gene, and the assemblage and multilocus genotype of G. duodenalis were investigated by analyzing three genes: bg, glutamate dehydrogenase (gdh) and triphosphate isomerase (tpi). Results: The overall G. duodenalis detection rate was 7.8%, 1.4% and 23.3% in fecal, environmental and water samples, respectively. On the large-scale sheep farms tested, the infection rate of sheep in Henan (13.8%) was found to be significantly higher than that of sheep in Ningxia (4.2%) (P < 0.05). However, the difference between the rates of environmental pollution in Henan (1.9%) and Ningxia (1.0%) was not significant (P > 0.05). Investigations of sheep at different physiological stages revealed that late pregnancy ewes showed the lowest infection rate (1.7%) and that young lambs exhibited the highest (18.8%). Genetic analysis identified G. duodenalis belonging to two assemblages, A and E, with assemblage E being dominant. A total of 27 multilocus genotypes were identified for members of assemblage E. Conclusions: The results suggest that G. duodenalis is prevalent on large-scale sheep farms in Henan and Ningxia, China, and that there is a risk of environmental contamination. This study is the first comprehensive examination of the presence of G. duodenalis on large-scale sheep farms in China. Challenges posed by G. duodenalis to sheep farms need to be addressed proactively to ensure public health safety. [ABSTRACT FROM AUTHOR]

A prevailing animal model currently used to study severe human diseases like obstructive cholestasis, primary biliary or sclerosing cholangitis, biliary atresia, and acute liver injury is the common bile duct ligation (cBDL). Modifications of this model include ligation of the left hepatic bile duct (pBDL) or ligation of the left bile duct with the corresponding left hepatic artery (pBDL+pAL). Both modifications induce cholestasis only in the left liver lobe. After induction of total or partial cholestasis in mice, the well-being of these animals was evaluated by assessing burrowing behavior, body weight, and a distress score. To compare the pathological features of these animal models, plasma levels of liver enzymes, bile acids, bilirubin, and within the liver tissue, necrosis, fibrosis, inflammation, as well as expression of genes involved in the synthesis or transport of bile acids were assessed. The survival rate of the animals and their well-being was comparable between pBDL+pAL and pBDL. However, surgical intervention by pBDL+pAL caused confluent necrosis and collagen depositions at the edge of necrotic tissue, whereas pBDL caused focal necrosis and fibrosis in between portal areas. Interestingly, pBDL animals had a higher survival rate and their well-being was significantly improved compared to cBDL animals. On day 14 after cBDL liver aspartate, as well as alanine aminotransferase, alkaline phosphatase, glutamate dehydrogenase, bile acids, and bilirubin were significantly elevated, but only glutamate dehydrogenase activity was increased after pBDL. Thus, pBDL may be primarily used to evaluate local features such as inflammation and fibrosis or regulation of genes involved in bile acid synthesis or transport but does not allow to study all systemic features of cholestasis. The pBDL model also has the advantage that fewer mice are needed, because of its high survival rate, and that the well-being of the animals is improved compared to the cBDL animal model. [ABSTRACT FROM AUTHOR]

The purpose of this study was to explore the carbon and nitrogen metabolism mechanisms of sand-cultivated cucumbers under different deficit irrigation–nitrogen management strategies and provide a theoretical basis for their greenhouse management. This study set up two factors, the deficit irrigation level and the nitrogen application rate, and conducted an experiment on deficit irrigation–nitrogen coupling of sand-cultivated cucumbers using a quadratic saturation D–optimal design. Seven treatments were set up in the experiment, to measure the soluble sugar and protein contents, as well as the activity of key enzymes for carbon and nitrogen metabolism at five different growth stages. The results indicate that the 80% irrigation with 623 kg N hm−2 (IN4) treatment significantly improved the soluble sugar, protein, and actual leaf nitrogen contents of cucumber at the five different growth stages and, as a result, achieved higher sucrose synthase (SS) and sucrose phosphate synthase (SPS) activities in the cucumber leaves. Furthermore, such improvements were due to the reduction in oxidative damage of sand–cultivated cucumber at various growth stages. The IN4 and 89% irrigation with 1250 kg N hm−2 (IN5) treatments significantly increased the activities of RuBisCO, catalase (CAT), peroxidise (POD), and superoxide dismutase (SOD) at various growth stages of sand-cultivated cucumber. The higher activities of glutamate dehydrogenase (GLDH), glutamate synthase (GOGAT), nitrate reductase (NR), glutamine synthase (GS), acid invertase enzyme (AIE), neutral invertase enzyme (NIE), and better antioxidative enzyme activities were recorded under the IN4 treatments at various growth stages, which effectively improve (69.6%) cucumber yield. The soil properties, carbon and nitrogen metabolism, and antioxidant metabolism were positively correlated with sand-cultivated cucumber yield in a greenhouse. We concluded that the IN4 treatment was the better deficit irrigation–nitrogen management strategy because it considerably improves carbon and nitrogen metabolism, antioxidant enzyme activities, and sand–cultivated cucumber yield in a greenhouse. [ABSTRACT FROM AUTHOR]

While cytostatic chemotherapy targeting DNA is known to induce genotoxicity, leading to cell cycle arrest and cytokine secretion, the impact of these drugs on fibroblast–epithelial cancer cell communication and metabolism remains understudied. Our research focused on human breast fibroblast RMF-621 exposed to nonlethal concentrations of cisplatin and doxorubicin, revealing reduced proliferation, diminished basal and maximal mitochondrial respirations, heightened mitochondrial ROS and lactate production, and elevated MCT4 protein levels. Interestingly, RMF-621 cells enhanced glucose uptake, promoting lactate export. Breast cancer cells MCF-7 exposed to conditioned media (CM) from drug-treated stromal RMF-621 cells increased MCT1 protein levels, lactate-driven mitochondrial respiration, and a significantly high mitochondrial spare capacity for lactate. These changes occurred alongside altered mitochondrial respiration, mitochondrial membrane potential, and superoxide levels. Furthermore, CM with doxorubicin and cisplatin increased migratory capacity in MCF-7 cells, which was inhibited by MCT1 (BAY-8002), glutamate dehydrogenase (EGCG), mitochondrial pyruvate carrier (UK5099), and complex I (rotenone) inhibitors. A similar behavior was observed in T47-D and ZR-75-1 breast cancer cells. This suggests that CM induces metabolic rewiring involving elevated lactate uptake to sustain mitochondrial bioenergetics during migration. Treatment with the mitochondrial-targeting antioxidant mitoTEMPO in RMF-621 and the addition of an anti-CCL2 antibody in the CM prevented the promigratory MCF-7 phenotype. Similar effects were observed in THP1 monocyte cells, where CM increased monocyte recruitment. We propose that nonlethal concentrations of DNA-damaging drugs induce changes in the cellular environment favoring a promalignant state dependent on mitochondrial bioenergetics. [ABSTRACT FROM AUTHOR]

This document discusses the modulation of γ-aminobutyric acid type A receptors (GABAA) by the endocannabinoid (eCB) system. The exact mechanism of this connection is still under debate, but experimental studies have shown that endocannabinoids enhance GABAA activity under conditions of low GABA concentrations and reduce GABAA activity at high GABA levels. The involvement of cannabinoid receptors in the regulation of GABAergic neurotransmission suggests that the eCB system may have anxiolytic effects through the modulation of GABAergic receptors. Additionally, the inhibition of glutamine synthetase (GS) influences GABAA receptor regulation, decreasing benzodiazepine binding. The expression of astrocytic GS is regulated by mitogen-activated protein kinases (MAPKs), with p38 upregulating and ERK1/2 downregulating GS. Further studies are needed to determine the exact mechanisms of these interactions. [Extracted from the article]

Cryptosporidium spp., Giardia intestinalis and microsporidia are unicellular opportunistic pathogens that can cause gastrointestinal infections in both animals and humans. Since companion animals may serve as a source of infection, the aim of the present screening study was to analyse the prevalence of these intestinal protists in fecal samples collected from dogs living in 10 animal shelters in central Europe (101 dogs from Poland and 86 from the Czech Republic), combined with molecular subtyping of the detected organisms in order to assess their genetic diversity. Genus-specific polymerase chain reactions were performed to detect DNA of the tested species and to conduct molecular subtyping in collected samples, followed by statistical evaluation of the data obtained (using χ2 or Fisher's tests). The observed prevalence was 15.5, 10.2, 1 and 1% for G. intestinalis, Enterocytozoon bieneusi, Cryptosporidium spp. and Encephalitozoon cuniculi, respectively. Molecular evaluation has revealed the predominance of dog-specific genotypes (Cryptosporidium canis XXe1 subtype; G. intestinalis assemblages C and D; E. cuniculi genotype II; E. bieneusi genotypes D and PtEbIX), suggesting that shelter dogs do not pose a high risk of human transmission. Interestingly, the percentage distribution of the detected pathogens differed between both countries and individual shelters, suggesting that the risk of infection may be associated with conditions typical of a given location.

Background: Whole plant senescence represents the final stage in the life cycle of annual plants, characterized by the decomposition of aging organs and transfer of nutrients to seeds, thereby ensuring the survival of next generation. However, the transcriptomic profile of vegetative organs during this death process remains to be fully elucidated, especially regarding the distinctions between natural programmed death and artificial sudden death induced by herbicide. Results: Differential genes expression analysis using RNA-seq in leaves and roots of Arabidopsis thaliana revealed that natural senescence commenced in leaves at 45–52 days after planting, followed by roots initiated at 52–60 days. Additionally, both organs exhibited similarities with artificially induced senescence by glyphosate. Transcription factors Rap2.6L and WKRY75 appeared to serve as central mediators of regulatory changes during natural senescence, as indicated by co-expression networks. Furthermore, the upregulation of RRTF1, exclusively observed during natural death, suggested its role as a regulator of jasmonic acid and reactive oxygen species (ROS) responses, potentially triggering nitrogen recycling in leaves, such as the glutamate dehydrogenase (GDH) shunt. Root senescence was characterized by the activation of AMT2;1 and GLN1;3, facilitating ammonium availability for root-to-shoot translocation, likely under the regulation of PDF2.1. Conclusions: Our study offers valuable insights into the transcriptomic interplay between phytohormones and ROS during whole plant senescence. We observed distinct regulatory networks governing nitrogen utilization in leaf and root senescence processes. Furthermore, the efficient allocation of energy from vegetative organs to seeds emerges as a critical determinant of population sustainability of annual Arabidopsis. [ABSTRACT FROM AUTHOR]

As a widely available, low-cost agricultural byproduct, bagasse is a potential solid carbon source and provides microbial attachment as a biofilm carrier. In this study, the effects of bagasse as a carbon source on biofloc formation, water quality, microbial community structure, and nitrogen conversion in a shrimp culture system were explored, and the performance of bagasse bioflocs was assessed. No bagasse was added to the control group (CK), and three bagasse addition groups were set up, with the floc content of the water maintained at 5 mL/L (BF5 group), 10 mL/L (BF10 group), and 15 mL/L (BF15 group). The results showed that bagasse bioflocs formed in the fourth week when bagasse was placed in the culture water, and the surface of bagasse was covered with thick biofilm at that time. The DOC content of the BF15 group was significantly greater than that of the CK group, from 30.31 to 105.06% (P < 0.05), and the DOC increased with increasing bagasse biofloc content. The BF group rapidly converted TAN to NO2−-N and then to NO3−-N because the accumulation of nitrite nitrogen in the BF15 group occurred 1 week earlier than in the other groups; at the 8th week, the nitrite nitrogen conversion rate of each BF group was close to 100%, which was significantly greater than that of the CK group (P < 0.05). The relative abundances of genes encoding microbial glutamate dehydrogenase and glutamate synthase increased in the bagasse biofloc groups (P < 0.05). The relative abundances of genes from Rhodobacterales and Hyphomicrobiales in each group were greater, but bagasse bioflocs increased the proportion of Hyphomicrobiale. In summary, adding bagasse to the shrimp culture system can form a biofloc system, resulting in the formation of a rich bacterial biofilm on its surface. Bagasse addition not only affects the composition of microbial communities but also accelerates the nitrification process in water. As a result, ammonia and nitrite are converted into nitrate, which is essential for maintaining the stability of the ecosystem balance in aquaculture water. [ABSTRACT FROM AUTHOR]

Crop production decreases because of water deficit stress conditions worldwide. Understanding genetic variation in enzymes and physiological responses of wheat genotypes under drought conditions is necessary to select tolerant genotypes for cultivation under drought conditions. These goals set 15 wheat genotypes for cultivation in the fall of 2022 with two irrigation interval regimes to evaluate their growth and yield-related traits for drought tolerance. The experiment had a randomized complete block design with three replications. Results showed highly significant differences among studied genotypes for all assessed traits. Genotype G11 gave the highest values in aldehyde dehydrogenase activity, spike per meter, grain yield, and biological yield (9.620 milliunits/mL, 975.8 spikes m-1, 10.725 t ha-1, and 29.568 t ha-1, respectively). Genotype G1 emerges with the utmost value for glutamate dehydrogenase activity (9.62 milliunits/mL), G2 for tillers per meter (1030.0 tillers m-1 ), G4 for spike length (11.17 cm), G6 for 1000-grain weight (40.8 g), G12 for grains per spike (40.9 grain spike-1 ), and G14 for plant height (117.2 cm). Likewise, water level treatments exhibited a significant impact on the studied traits. However, genotype G11 was leading in grain and biological yields. The five-day irrigation interval treatment gave the highest values in all studied traits except for glutamate dehydrogenase activity. Therefore, the study concluded that wheat genotypes responded differently to water level treatments and water stress at 14-day irrigation intervals, which can benefit screening the wheat genotypes for water deficit stress. [ABSTRACT FROM AUTHOR]

Drug-induced liver injury (DILI) is a challenge in clinical medicine and drug development. Highly sensitive novel biomarkers have been identified for detecting DILI following a paracetamol overdose. The study objective was to evaluate biomarker performance in a 14-day trial of therapeutic dose paracetamol. The PATH-BP trial was a double-blind, placebo-controlled, crossover study. Individuals (n  = 110) were randomized to receive 1 g paracetamol 4× daily or matched placebo for 2 weeks followed by a 2-week washout before crossing over to the alternate treatment. Blood was collected on days 0 (baseline), 4, 7, and 14 in both arms. Alanine transaminase (ALT) activity was measured in all patients. MicroRNA-122 (miR-122), cytokeratin-18 (K18), and glutamate dehydrogenase (GLDH) were measured in patients who had an elevated ALT on paracetamol treatment (≥50% from baseline). ALT increased in 49 individuals (45%). All 3 biomarkers were increased at the time of peak ALT (K18 paracetamol arm: 18.9 ± 9.7 ng/ml, placebo arm: 11.1 ± 5.4 ng/ml, ROC-AUC = 0.80, 95% CI 0.71–0.89; miR-122: 15.1 ± 12.9fM V 4.9 ± 4.7fM, ROC-AUC = 0.83, 0.75–0.91; and GLDH: 24.6 ± 31.1U/l V 12.0 ± 11.8U/l, ROC-AUC = 0.66, 0.49–0.83). All biomarkers were correlated with ALT (K18 r  = 0.68, miR-122 r  = 0.67, GLDH r  = 0.60). To assess sensitivity, biomarker performance was analyzed on the visit preceding peak ALT (mean 3 days earlier). K18 identified the subsequent ALT increase (K18 ROC-AUC = 0.70, 0.59–0.80; miR-122 ROC-AUC = 0.60, 0.49–0.72, ALT ROC-AUC = 0.59, 0.48–0.70; GLDH ROC-AUC = 0.70, 0.50–0.90). Variability was lowest for ALT and K18. In conclusion, K18 was more sensitive than ALT, miR-122, or GLDH and has potential significant utility in the early identification of DILI in trials and clinical practice. [ABSTRACT FROM AUTHOR]

Lysophosphatidylcholine (LPC) is immunomodulatory in nonruminants; however, the actions of LPC on immunity in cattle are undefined. Our objective was to study the effects of LPC administration on measures of immunity, liver health, and growth in calves. Healthy Holstein heifer calves (n = 46; age 7 ± 3 d) were randomly assigned to 1 of 4 treatments (n = 10 to 11 calves/treatment): a milk replacer diet unsupplemented with lecithin in the absence (CON) or presence of subcutaneously (s.c.) administered mixed (mLPC; 69% LPC-16:0, 25% LPC-18:0, 6% other) or pure LPC (pLPC; 99% LPC-18:0), or a milk replacer diet supplemented with 3% lecithin enriched in lysophospholipids containing LPC in the absence of s.c.-administered LPC (LYSO) for 5 wk. Calves received 5 s.c. injections of vehicle (10 mL of phosphate-buffered saline containing 20 mg of bovine serum albumin/mL; CON and LYSO) or vehicle containing mLPC or pLPC to provide 10 mg of total LPC per kilogram of BW per injection every 12 h during wk 2 of life. Calves were fed a milk replacer containing 27% crude protein and 24% fat at 1.75% of BW per day (dry matter basis) until wk 6 of life (start of weaning). Starter grain and water were provided ad libitum. Body measurements were recorded weekly, and clinical observations were recorded daily. Blood samples were collected weekly before morning feeding and at 0, 5, and 10 h, relative to the final s.c. injection of vehicle or LPC. Data were analyzed using a mixed model, with repeated measures including fixed effects of treatment, time, and their interaction. Dunnett's test was used to compare treatments to CON. Peak rectal temperatures were higher in mLPC or pLPC, relative to CON. Plasma LPC concentrations were greater in mLPC and LYSO calves 5 h and 10 h after the final injection, relative to CON. Calves receiving mLPC and pLPC also had higher circulating serum amyloid A concentrations, relative to CON. Calves receiving mLPC had greater serum aspartate aminotransferase, γ-glutamyltransferase, and glutamate dehydrogenase concentrations, relative to CON. Calves provided mLPC experienced lower average daily gain (ADG) after weaning, relative to CON. The LYSO treatment did not modify rectal temperatures, ADG, or measures of liver health, relative to CON. We conclude that LPC administered as s.c. injections induced an acute febrile response, modified measures of liver and immune function, and impaired growth in calves. [ABSTRACT FROM AUTHOR]

Despite global warming, the response of rice yield to long-term warming in cool regions and its physiological mechanisms remain unknown. This study used the widely cultivated japonica rice Jiyang100 in Northeast China. Taking rice grown under natural temperatures as a control (CK), field warming treatments were conducted at the tillering-panicle initiation (T1), whole growth (T2), and grain-filling (T3) stages. The positive effects of T1, T2, and T3 on the total number of spikelets per hole increased the yield in both years, with average increases of 11.5%, 9.9% and 6.5% compared to CK, respectively. Warming treatments improved the stay-green traits, photosynthesis, sucrose synthesis, and nitrogen metabolism of rice. The yield was positively correlated with the relative chlorophyll content (SPAD), soluble sugar content, sucrose content, and the activities of sucrose phosphate synthase (SPS), nitrate reductase (NR), glutamine synthetase (GS), glutamine oxoglutarate aminotransferase (GOGAT) in flag leaves. In addition, SPAD had a positive correlation with soluble sugar content, soluble protein content, and the activities of NR, GS, GOGAT, glutamate dehydrogenase (GDH), but a negative correlation with acid invertase (AI) activity. The stay-green ability was positively correlated to the net photosynthetic rate (Pn), soluble sugar content and soluble protein content. The coupling interactions of stay-green traits, nitrogen and carbon metabolism increased the yield potential and yield supply capacity, increased yield under long-term warming conditions in the cool regions. Under gradual warming, the physiological response of rice in cool regions promotes plant growth and development, thereby increasing yield. [ABSTRACT FROM AUTHOR]

Background: Salt stress is one of the most common abiotic stresses, reducing plant growth and productivity. Thus, the development of suitable management practices to minimize the deleterious effects of salt stress has become necessary. Aims: This study was conducted to investigate the possible mechanisms underlying salt tolerance conferred by jasmonic acid (JA). Methods: Salt‐stressed wheat seedlings were supplemented with 1 mM JA and/or 1 mM ibuprofen (IBU), an inhibitor of endogenous JA biosynthesis, in the culture medium. Results: The obtained results showed that salt stress significantly decreased shoot and root dry weight production and relative water contents. This was associated with a noteworthy reduction in leaf and root ascorbate (AsA) concentrations, as well as glutamine synthetase (GS), glutamate synthase (GOGAT), and glutamate dehydrogenase (GDH) activities. Exogenously supplied JA did not affect GS and GOGAT activities in leaves and roots of salt‐treated seedlings. However, noticeable enhancements were observed in growth, AsA concentrations, as well as GDH activities. Likewise, the inhibition of JA biosynthesis by IBU application was accompanied by a significant decrease in seedlings' growth associated with a noticeable reduction in AsA concentrations and GDH activities. The decreases in growth and GDH activities were also obtained following inhibition of AsA biosynthesis by lycorine (Lyc) application. By contrast, increased GDH activities and enhanced growth were obtained following exogenous AsA supplementation, with or without JA biosynthesis inhibition. Conclusions: The findings implied that exogenous JA enhanced AsA biosynthesis and induced GDH activity, which further promoted the growth of wheat seedlings in salt‐stressed conditions. Therefore, the stimulation of AsA biosynthesis and GDH activity through JA application in the rhizosphere may be suggested as a vital strategy for strengthening the salt tolerance of wheat plants, at least at the seedling stage. [ABSTRACT FROM AUTHOR]

We previously showed that the transaminase inhibitor, aminooxyacetic acid, reduced respiration energized at complex II (succinate dehydrogenase, SDH) in mitochondria isolated from mouse hindlimb muscle. The effect required a reduction in membrane potential with resultant accumulation of oxaloacetate (OAA), a potent inhibitor of SDH. To specifically assess the effect of the mitochondrial transaminase, glutamic oxaloacetic transaminase (GOT2) on complex II respiration, and to determine the effect in intact cells as well as isolated mitochondria, we performed respiratory and metabolic studies in wildtype (WT) and CRISPR-generated GOT2 knockdown (KD) C2C12 myocytes. Intact cell respiration by GOT2KD cells versus WT was reduced by adding carbonyl cyanide-p-trifluoromethoxyphenylhydrazone (FCCP) to lower potential. In mitochondria of C2C12 KD cells, respiration at low potential generated by 1 µM FCCP and energized at complex II by 10 mM succinate + 0.5 mM glutamate (but not by complex I substrates) was reduced versus WT mitochondria. Although we could not detect OAA, metabolite data suggested that OAA inhibition of SDH may have contributed to the FCCP effect. C2C12 mitochondria differed from skeletal muscle mitochondria in that the effect of FCCP on complex II respiration was not evident with ADP addition. We also observed that C2C12 cells, unlike skeletal muscle, expressed glutamate dehydrogenase, which competes with GOT2 for glutamate metabolism. In summary, GOT2 KD reduced C2C12 respiration in intact cells at low potential. From differential substrate effects, this occurred largely at complex II. Moreover, C2C12 versus muscle mitochondria differ in complex II sensitivity to ADP and differ markedly in expression of glutamate dehydrogenase. NEW & NOTEWORTHY: Impairment of the mitochondrial transaminase, GOT2, reduces complex II (succinate dehydrogenase, SDH)-energized respiration in C2C12 myocytes. This occurs only at low inner membrane potential and is consistent with inhibition of SDH. Incidentally, we observed that C2C12 mitochondria compared with muscle tissue mitochondria differ in sensitivity of complex II respiration to ADP and in the expression of glutamate dehydrogenase. [ABSTRACT FROM AUTHOR]

Nanomaterials, including ZIF‐8 nanoparticles (NPs), are shown to be effective antimicrobial agents against Methicillin‐resistant Staphylococcus aureus(MRSA). However, the antibiofilm properties and mechanisms of ZIF‐8 NPs remain uncertain. In this study, ZIF‐8 NPs are prepared using the room temperature solution reaction method and characterized. Biofilm formation inhibition test and biofilm eradication test are performed and the results show that ZIF‐8 NPs can inhibit the formation of MRSA biofilm as well as disperse established MRSA biofilm. Proteomics and real‐time fluorescence quantitative polymerase chain reaction (PCR) are conducted to prove that ZIF‐8 NPs reduce the expression of adhesion‐related proteins, namely the fibronectin‐binding proteins A and B (fnbA/fnbB), fibrinogen binding protein caking factors A and B (clfA/clfB), elastin binding protein (ebps), and fibrin binding protein (eno). ZIF‐8 NPs also inhibit the arginine biosynthesis pathway by affecting the activities of argininosuccinate lyase, ornithine carbamyl transferase, Glutamate dehydrogenase, carbamate kinase, and arginine deiminase. A conclusion can be drawn from the above results that ZIF‐8 NPs can inhibit bacterial adhesion and kill bacteria directly, ultimately destroying MRSA biofilm. This study provides a molecular basis for the treatment of MRSA biofilm with ZIF‐8 NPs. [ABSTRACT FROM AUTHOR]

Background: 1,5-pentanediol (1,5-PDO) is a linear diol with an odd number of methylene groups, which is an important raw material for polyurethane production. In recent years, the chemical methods have been predominantly employed for synthesizing 1,5-PDO. However, with the increasing emphasis on environmentally friendly production, it has been a growing interest in the biosynthesis of 1,5-PDO. Due to the limited availability of only three reported feasible biosynthesis pathways, we developed a new biosynthetic pathway to form a cell factory in Escherichia coli to produce 1,5-PDO. Results: In this study, we reported an artificial pathway for the synthesis of 1,5-PDO from lysine with an integrated cofactor and co-substrate recycling and also evaluated its feasibility in E.coli. To get through the pathway, we first screened aminotransferases originated from different organisms to identify the enzyme that could successfully transfer two amines from cadaverine, and thus GabT from E. coli was characterized. It was then cascaded with lysine decarboxylase and alcohol dehydrogenase from E. coli to achieve the whole-cell production of 1,5-PDO from lysine. To improve the whole-cell activity for 1,5-PDO production, we employed a protein scaffold of EutM for GabT assembly and glutamate dehydrogenase was also validated for the recycling of NADPH and α-ketoglutaric acid (α-KG). After optimizing the cultivation and bioconversion conditions, the titer of 1,5-PDO reached 4.03 mM. Conclusion: We established a novel pathway for 1,5-PDO production through two consecutive transamination reaction from cadaverine, and also integrated cofactor and co-substrate recycling system, which provided an alternative option for the biosynthesis of 1,5-PDO. [ABSTRACT FROM AUTHOR]

Excitotoxicity is a common pathological process in neurological diseases caused by excess glutamate. The purpose of this study was to evaluate the effect of gypenoside XVII (GP-17), a gypenoside monomer, on the glutamatergic system. In vitro, in rat cortical nerve terminals (synaptosomes), GP-17 dose-dependently decreased glutamate release with an IC50 value of 16 μM. The removal of extracellular Ca2+ or blockade of N-and P/Q-type Ca2+ channels and protein kinase A (PKA) abolished the inhibitory effect of GP-17 on glutamate release from cortical synaptosomes. GP-17 also significantly reduced the phosphorylation of PKA, SNAP-25, and synapsin I in cortical synaptosomes. In an in vivo rat model of glutamate excitotoxicity induced by kainic acid (KA), GP-17 pretreatment significantly prevented seizures and rescued neuronal cell injury and glutamate elevation in the cortex. GP-17 pretreatment decreased the expression levels of sodium-coupled neutral amino acid transporter 1, glutamate synthesis enzyme glutaminase and vesicular glutamate transporter 1 but increased the expression level of glutamate metabolism enzyme glutamate dehydrogenase in the cortex of KA-treated rats. In addition, the KA-induced alterations in the N-methyl-D-aspartate receptor subunits GluN2A and GluN2B in the cortex were prevented by GP-17 pretreatment. GP-17 also prevented the KA-induced decrease in cerebral blood flow and arginase II expression. These results suggest that (i) GP-17, through the suppression of N- and P/Q-type Ca2+ channels and consequent PKA-mediated SNAP-25 and synapsin I phosphorylation, reduces glutamate exocytosis from cortical synaptosomes; and (ii) GP-17 has a neuroprotective effect on KA-induced glutamate excitotoxicity in rats through regulating synaptic glutamate release and cerebral blood flow. [ABSTRACT FROM AUTHOR]

Salinity is a global challenge to sustainable agriculture, impacting plant growth at cellular and functional levels. Nevertheless, silicon (Si), a multifunctional micro-element, plays a vital role in restoring and maintaining growth and development during unfavourable abiotic conditions such as high salinity exposure. Therefore, in the current research, two salinity levels [S1; 1 M (1000 mM) NaCl and S2; 2 M (2000 mM) NaCl] were used to assess the effects of exogenous Si (Si-1; 150 mg/L and Si-2; 250 mg/L) on key biological characteristics and especially the metabolite profiles of Panicum turgidum plants. Our findings revealed that the salt stress negatively affected the plants through high salt content (Na+ and Cl−) that further antagonized the essential nutrient balance in tissues; increased NH 4 +, but lowered NO 3 − and K+ in both roots and leaves. The excessive production of NH 4 + led to over-accumulation of methylglyoxal (MG), resulting in the hyper-accumulation of sugars and altering the concentrations of amino acids, thereby inducing diabetes-like symptoms in P. turgidum plants. Interestingly, Si application restored the growth of P. turgidum plants by reducing oxidative damage thereby modifying the nutritional status, metabolic and biochemical characteristics of the plants. Specifically, the application of Si-2 showed improvement of key biological indictors in leaves and roots under both salinity levels. The current study also demonstrated that Si substantially reduced the NH 4 +-mediated MG-induced stress by lowering the concentration of MG, up-regulating the antioxidant capacity of various enzymes glyoxalase I (Gly-I), glyoxalase II (Gly-II), glutathione (GSH), glutamine: 2-oxoglutarate aminotransferase (GOGAT), nitrate reductase (NR), glutamine synthetase (GS), glutamate dehydrogenase (GDH); with concomitant changes in the levels of sugar/carbohydrates in roots and leaves of P. turgidum. [Display omitted] • The over-accumulation of salt ions negatively affected the essential nutrients uptake and altered the metabolic profile of Panicum turgidum. • The imbalanced NH 4 + and NO 3 − ratio resulted in the hyper-accumulation of methylglyoxal (MG) and carbohydrates; concomitant lowering of the amino acids content leading to diabetes-like symptoms in Panicum turgidum. • Silicon effectively reduced the negative impacts of salinity by reducing the MG and NH 4 + content, thereby restoring the nutritional, biochemical, and metabolic profile of Panicum turgidum plants undergoing unfavorable conditions. [ABSTRACT FROM AUTHOR]

The excitatory neurotransmitter glutamate has a role in neuronal migration and process elongation in the central nervous system (CNS). The effects of chronic glutamate hyperactivity on vesicular and protein transport within CNS neurons, that is, processes necessary for neurite growth, have not been examined previously. In this study, we measured the effects of lifelong hyperactivity of glutamate neurotransmission on axoplasmic transport in CNS neurons. We compared wild-type (wt) to transgenic (Tg) mice over-expressing the glutamate dehydrogenase gene Glud1 in CNS neurons and exhibiting increases in glutamate transmitter formation, release, and synaptic activation in brain throughout the lifespan. We found that Glud1 Tg as compared with wt mice exhibited increases in the rate of anterograde axoplasmic transport in neurons of the hippocampus measured in brain slices ex vivo, and in olfactory neurons measured in vivo. We also showed that the in vitro pharmacologic activation of glutamate synapses in wt mice led to moderate increases in axoplasmic transport, while exposure to selective inhibitors of ion channel forming glutamate receptors very significantly suppressed anterograde transport, suggesting a link between synaptic glutamate receptor activation and axoplasmic transport. Finally, axoplasmic transport in olfactory neurons of Tg mice in vivo was partially inhibited following 14-day intake of ethanol, a known suppressor of axoplasmic transport and of glutamate neurotransmission. The same was true for transport in hippocampal neurons in slices from Glud1 Tg mice exposed to ethanol for 2 h ex vivo. In conclusion, endogenous activity at glutamate synapses regulates and glutamate synaptic hyperactivity increases intraneuronal transport rates in CNS neurons. [ABSTRACT FROM AUTHOR]

Background Multistep laboratory testing is recommended for the diagnosis of Clostridioides difficile infection (CDI). The aim of this study was to present the impact of multistep CDI diagnostic testing in an academic hospital system and evaluate the toxin B gene polymerase chain reaction (PCR) cycle threshold (Ct) values of PCR-positive tests. Methods In October 2022, our system began reflex testing all PCR-positive stool samples with the C. DIFF QUIK CHEK COMPLETE (Techlab), an enzyme immunoassay–based test with results for the glutamate dehydrogenase antigen (GDH) and C difficile toxin A/B. Hospital-onset (HO) CDI and CDI antibiotic use before and after testing were tracked. Ct values were obtained from the Infectious Diseases Diagnostic Laboratory. Receiver operating curve analysis was used to examine the sensitivity and specificity for identifying GDH+/toxin+ and GDH−/toxin− at various Ct thresholds. Results The HO-CDI rate decreased from 0.352 cases per 1000 patient-days to 0.115 cases per 1000 patient-days post–reflex testing (P <.005). Anti-CDI antibiotics use decreased, but the decrease was not commensurate with CDI rates following reflex testing. PCR+/GDH+/toxin+ samples had a lower mean Ct value than PCR+/GDH–/toxin– samples (23.3 vs 33.5, P <.0001). A Ct value of 28.65 could distinguish between those 2 groups. Fifty-four percent of PCR+/GDH+/toxin− samples had a Ct value below that cut-off, suggesting the possibility of CDI with a negative toxin test. Conclusions Reflex testing for a laboratory diagnosis of CDI results in rapid, systemwide decreases in the rate of HO-CDI. Additional research is needed to distinguish CDI from C difficile colonization in patients with discordant testing. [ABSTRACT FROM AUTHOR]

The present study examined the regulatory mechanism of hydrogen sulfide (H2S) and nitric oxide (NO) in nickel (Ni) stressed cyanobacteria viz., Nostoc muscorum and Anabaena sp. by analyzing growth, photosynthetic pigments, biochemical components (protein and carbohydrate), exopolysaccharides (EPS), inorganic nitrogen content, and activity of enzymes comprised in nitrogen metabolism and Ni accumulation. The 1 µM Ni substantially diminished growth by 18% and 22% in N. muscorum and Anabaena sp. respectively, along with declining the pigment contents (Chl a/Car ratio and phycobiliproteins), and biochemical components. It also exerted negative impacts on inorganic uptake of nitrate and nitrite contents; nitrate reductase and nitrite reductase; and ammonium assimilating enzymes (glutamine synthetase, glutamate synthase, and glutamate dehydrogenase exhibited a reverse trend) activities. Nonetheless, the adverse impact of Ni can be mitigated through the exogenous supplementation of NaHS [sodium hydrosulfide (8 µM); H2S donor] and SNP [sodium nitroprusside (10 µM); NO donor] which showed substantial improvement on growth, pigments, nitrogen metabolism, and EPS layer and noticeably occurred as a consequence of a substantial reduction in Ni accumulation content which minimized the toxicity effects. The accumulation of Ni on both the cyanobacterial cell surface (EPS layer) are confirmed by the SEM–EDX analysis. Further, the addition of NO scavenger (PTIO; 20 µM) and inhibitor of NO (L-NAME; 100 µM); and H2S scavenger (HT; 20 µM) and H2S inhibitor (PAG; 50 µM) reversed the positive responses of H2S and NO and damages were more prominent under Ni stress thereby, suggesting the downstream signaling of H2S on NO-mediated alleviation. Thus, this study concludes the crosstalk mechanism of H2S and NO in the mitigation of Ni-induced toxicity in rice field cyanobacteria. [ABSTRACT FROM AUTHOR]

Hepatitis A virus (HAV) infects humans and nonhuman primates, typically causing an acute self-limited illness. Three HAV genotypes have been described so far for humans, and three genotypes have been described for nonhuman primates. We observed transiently elevated liver enzymes in Mauritius-origin laboratory-housed macaques in Germany and were not able to demonstrate an etiology including HAV by serology and polymerase chain reaction (PCR). HAV is a rare pathogen in cynomolgus macaques, and since all employees were routinely vaccinated against HAV, it was not a part of the routine vaccination and screening program. A deep sequencing approach identified a new HAV genotype (referred to as Simian_HAV_Macaca/Germany/Mue-1/2022) in blood samples from affected animals. This HAV was demonstrated by reverse transcription PCR in blood and liver and by in situ hybridization in liver, gall bladder, and septal ducts. A commercial vaccine was used to protect animals from liver enzyme elevation. The newly identified simian HAV genotype demonstrates 80% nucleotide sequence identity to other simian and human HAV genotypes. There was deeper divergence between Simian_HAV_Macaca/Germany/Mue-1/2022 and other previously described HAVs, including both human and simian viruses. In situ hybridization indicated persistence in the biliary epithelium up to 3 months after liver enzymes were elevated. Vaccination using a commercial vaccine against human HAV prevented reoccurrence of liver enzyme elevations. Because available assays for HAV did not detect this new HAV genotype, knowledge of its existence may ameliorate potential significant epidemiological and research implications in laboratories globally. [ABSTRACT FROM AUTHOR]

There are two paralogs of glutamate dehydrogenase (GDH) in humans encoded by the GLUD1 and GLUD2 genes as a result of a recent retroposition during the evolution of primates. The two human GDHs possess significantly different regulation by allosteric ligands, which is not fully characterized at the structural level. Recent advances in identification of the GDH ligand binding sites provide a deeper perspective on the significance of the accumulated substitutions within the two GDH paralogs. In this review, we describe the evolution of GLUD1 and GLUD2 after the duplication event in primates using the accumulated sequencing and structural data. A new gibbon GLUD2 sequence questions the indispensability of ancestral R496S and G509A mutations for GLUD2 irresponsiveness to GTP, providing an alternative with potentially similar regulatory features. The data of both GLUD1 and GLUD2 evolution not only confirm substitutions enhancing GLUD2 mitochondrial targeting, but also reveal a conserved mutation in ape GLUD1 mitochondrial targeting sequence that likely reduces its transport to mitochondria. Moreover, the information of GDH interactors, posttranslational modification and subcellular localization are provided for better understanding of the GDH mutations. Medically significant point mutations causing deregulation of GDH are considered from the structural and regulatory point of view. [ABSTRACT FROM AUTHOR]