Diplatin, a Novel and Low-Toxicity Anti-Lung Cancer Platinum Complex, Activation of Cell Death in Tumors via a ROS/JNK/p53-Dependent Pathway, and a Low Rate of Acquired Treatment Resistance

Background: Platinum-based drugs prevail as the main treatment of lung cancer; this is caused by their relative effectiveness despite known side effects, such as neurotoxicity. The risk reward of the treatment and side effects is confronted when dosage is considered and when resistance to treatment develops. Development of new compounds that improve effectiveness and safety profiles addresses this ongoing need in clinical practice.

Objectives: The novel water-soluble platinum complex, diplatin, was synthesized, and its antitumor potency and toxicology profile were evaluated in murine xenograft tumor models and in lung cancer cell lines.

Methods: The effects of diplatin, cisplatin (DDP), and carboplatin (CBP) on the viability of nine lung tumor cell lines and one normal human lung epithelial cell line were evaluated using the MTT assay. Therapeutic index was calculated as LD₅₀/ED₅₀ to identify and compare the ideal therapeutic windows of the above compounds. Diplatin’s antitumor effects were assessed in lung xenograft tumors of nude mice; molecular mechanisms of therapeutic effects were identified.

Results: Diplatin had desirable IC₅₀ compared to CBP in a variety of cultured tumor cells, notably lung tumor cells. In the mouse xenograft lung tumor, diplatin led to a substantially improved therapeutic index when compared to the effects of DDP and CBP. Importantly, diplatin inhibited the growth of DDP-resistant lung tumor cells. Diplatin’s mode of action was characterized to be through cell cycle arrest in the G2/M phase and induction of lung tumor apoptosis via ROS/JNK/p53-mediated pathways.

Conclusion: Diplatin was observed to have antitumor effects in mice with both greater potency and safety compared with DDP and CBP. These observations indicate that diplatin is promising as a potential treatment in future clinical applications.

Effect of infectious bursal disease virus infection on energy metabolism in embryonic chicken livers

1. The purpose of this study was to investigate ATP levels and the activities of important enzymes involved in glycolysis and TCA cycle in livers of embryonated chicken eggs infected by infectious bursal disease virus (IBDV).2. Embryonated chicken eggs (9 days) were randomly divided into two groups (50 eggs per group). The first group was inoculated with a very virulent IBDV (vvIBDV) isolate into the chorioallantoic membrane. The second group was maintained as uninfected control eggs and inoculated with physiological saline. Embryo survival was assessed daily, and six embryos were sacrificed at 24, 48, 72, 96, and 120 hpi for examining livers. Viral loads in the livers were evaluated by qRT-PCR. A comparative analysis of markers associated with the regulation of energy metabolism across several functional classes (ATP, pyruvic and lactic acids, mitochondrial protein, NAD+/NADH ratios, and enolase, lactic acid dehydrogenase and the respiratory chain complex I activities) were examined in the context of IBDV infection.3. The results indicated that increases in the enzymatic activities associated with glycolytic metabolism in turn affected the synthesis and cytoplasmic concentrations of ATP at early timepoints in infected chicken embryos. Subsequently, energy metabolism was inhibited through the pathological perturbations of metabolic enzymes and mitochondrial damage, as inferred from reduced ATP generation.4. These results suggested impaired bioenergetics, which may lead to liver dysfunction consequent to IBDV infection, contributing to the disease pathogenesis.

[Role of erythroblast-like Ter cells in the pathogenesis of collagen-induced arthritis]

OBJECTIVE

To explore the role of Ter cells in the development of the collagen-induced arthritis (CIA), we detected their quantity changes in the spleen of different stages of CIA mice and analyzed the correlation between Ter cells and the joint scores, and we also analyzed the correlation between Ter cells and the frequencies of T and B cell subsets, so as to further understand the pathogenesis of rheumatoid arthritis.

METHODS

The six to eight weeks DBA/1 mice were used to prepare CIA model. After the second immunization, we began to evaluate the joint score. According to the time of CIA onset and the joint score, the CIA mice were divided into three stages: early, peak and late stages. According to the final joint score, the CIA mice at the peak stage were subdivided into the high score group (score>8) and the low score group (score≤8). The frequencies of Ter cells in the spleen of the naïve mice and the CIA mice at various stages and the frequencies of T and B cell subsets in the spleen of the CIA mice at the peak stage were detected by flow cytometry, then we carried on the correlation analysis.

RESULTS

The frequencies of Ter cells in the spleen of the CIA mice was significantly higher than those of the naïve mice (8.522%±2.645% vs. 1.937%±0.725%, P<0.01), the frequencies of Ter cells in the spleen of the high score group mice was significantly lower than those of the low score group (6.217%±0.841% vs. 10.827%±0.917%, P<0.01). The frequencies of Th1 cells in the spleen of the high score group mice was significantly higher than those of the low score group mice (1.337%±0.110% vs. 0.727%±0.223%, P<0.05). The frequencies of Th17 cells in the spleen of the high score group mice was higher than those of the low score group mice (0.750%±0.171% vs. 0.477%±0.051%, P=0.099). The frequencies of germinal center B cells in the spleen of the high score group mice was significantly higher than those of the low score group mice (1.243%±0.057% vs. 1.097%±0.015%, P<0.05). Correlation analysis results showed that the frequencies of Ter cells in the spleen of the CIA mice at the peak stage was strongly negatively correlated with the frequencies of CD4+ T, Th1, Th17, and germinal center B cells, and was strongly positively correlated with the frequencies of B10 cells, indicating that these cells might have a protective effect in CIA. Studies on dynamic changes showed that the frequencies of Ter cells in the spleen of the CIA mice at the late stage was significantly lower than those at the peak stage (0.917%±0.588% vs. 8.522%±2.645%, P<0.001), suggesting the protective effect of these cells in arthritis.

CONCLUSION

Ter cells were significantly increased in the spleen of the CIA mice at peak stage, and were negatively correlated with joint scores and pathogenic immune cells, and positively correlated with protective immune cells. Ter cells were significantly decreased in the spleen of the CIA mice at the late stage. What we mentioned above suggests that Ter cells might be involved in the progression of rheumatoid arthritis as an immunomodulatory cell,but further in vivo and in vitro experiments are needed to verify its specific effects and mechanism.

On-line quantitative analysis of heavy metals in water based on laser-induced breakdown spectroscopy

Heavy metal pollution from industrial wastewater is an important source. A method for heavy metals determination in industrial wastewater based on laser-induced breakdown spectroscopy (LIBS) technique was studied and the on-line monitoring system that used automatic graphite enrichment and spatial plasma confinement detection was developed and field demonstrated. The limits of detection (LOD) of heavy metal elements (Cd, Cr, Cu, Ni, Pb, Zn) could reach several μg/L. In Tongling, the on-line heavy metal monitor was field demonstrated. The calibration curves of copper and zinc were built on site, and then on-line monitoring was conducted. The measurement results of this monitor were compared with ICP-OES and had a good correlation. The results showed that the heavy metal monitor could be used for on-line detection of heavy metals in wastewater and had a good reliability.

Association of Fruit and Vegetable Intake and Frailty among Chinese Elders: A Cross-Sectional Study in Three Cities

OBJECTIVES

To examine the association of FVI and frailty in Chinese elders.

DESIGN

A sectional study was conducted in three cities (Shanghai, Zhengzhou, and Baoji) in China from June 2017 to June 2018.

PARTICIPANTS

A total of 5699 participants from 49 districts were included in the current study by two-stage sampling methods.

MEASUREMENTS

Frailty was measured by a validated Chinese version of the FRAIL scale. FVI per day was measured by two single questions.

RESULTS

The sample proportion with sufficient fruit intake was 36.7%, and 44.7% reported sufficient vegetable intake. The sample proportions that were robust, pre-frail, and frail were 43.6%, 38.3%, and 18.1%, respectively. Compared with low FVI, after including covariates, the odds ratio (OR) of frailty was 0.84 (95% CI: 0.73-0.97) for moderate fruit intake and 0.81 (95% CI: 0.70-0.94) for enough fruit intake; the OR of frailty was 0.83 (95% CI: 0.68-0.91) for moderate vegetable intake and 0.77 (95% CI: 0.64-0.93) for enough vegetable intake.

CONCLUSION

High FVI was negatively associated with the OR of frailty in Chinese elders. This finding implies it is important to promote FVI among adults to prevent frailty.

Is metformin still the most efficacious first-line oral hypoglycaemic drug in treating type 2 diabetes? A network meta-analysis of randomized controlled trials

OBJECTIVES

The objective of the study is to compare the efficacy of hypoglycaemic drugs for type 2 diabetes mellitus (T2DM) by network meta-analysis of randomized controlled trials (RCTs).

METHODS

We compared 11 major oral hypoglycaemic drugs under five categories evaluated by RCTs as drug monotherapy for the patients with T2DM, measuring glycosylated haemoglobin (%) or fasting plasma glucose (mmol L^-1 ) as outcomes. RCT quality was assessed with the Cochrane risk of bias tool. Network meta-analysis estimated the mean differences and 95% credible intervals. Subgroup and sensitivity analyses were performed to determine the results robustness. The Grading of Recommendation, Assessment, Development, and Evaluation evidence strength was assessed.

RESULTS

Seventy-five RCTs including 33,830 patients were identified. Their study quality was high. Regarding glycosylated haemoglobin, top three anti-diabetics were repaglinide (mean differences -1.39 [95% credible intervals -1.75 to -1.03]), gliclazide (-1.37 [-2.04 to -0.71]) and metformin (-1.13 [-1.37 to -0.90]), against placebo. Regarding fasting plasma glucose, top three anti-diabetics were repaglinide (-2.01 [-2.75 to -0.97]), metformin (-1.72 [-2.16 to -1.27]) and glipizide (-1.57 [-2.44 to -0.64]), against placebo. There was no difference between metformin and repaglinide. Subgroup and sensitivity analyses found the results to be robust. The evidence strength was moderate to high.

CONCLUSION

This meta-analysis showed that repaglinide and metformin would be the most efficacious oral drugs for first-line monotherapy of T2DM.

[Systemic lupus erythematosus with acquired hemophilia A: a case report]

Acquired hemophilia A (AHA) is anunusual disease resulting from autoantibodies (inhibitors) against coagulation factor VIII (FVIII) and clinically manifests as bleeding, which sometimes can cause potentially limb-threatening or life-threatening situations. AHA is associated with cancers, auto-immune disorders, infections, dermatologic conditions and certain medications, among which it is commonly secondary to multiple rheumatologic conditions, such as rheumatoid arthritis, systemic lupus erythematosus (SLE), pollymyositis, autoimmune hemolytic anemia and undifferentiated connective tissue disease. In autoimmune diseases, it may be the result of autoantibody producing against FVIII, and some cases of AHA may act as the first manifestation of SLE. AHA should be suspected in patients who have spontaneously hemorrhagic events with an isolated prolonged activated partial thromboplastin time (APTT), reduced FVIII activity and a negative lupus anticoagulant (LA). When FVIII inhibitor is found, it can be diagnosed. The management of AHA focuses on the following goals: (1) controlling and preventing bleeding, (2) eradication of the inhibitor, (3) treatment of the underlying disease. Here, a case of AHA in a patient with lupus is reported. A 53-year-old man with a 4-year history of SLE developed arthralgia and ecchymotic skin lesions after arthrocentesis of knee joint. Ultrasound confirmed the presence of an intramuscular hematoma. Coagulation tests revealed that FVIII activity reduced to 1% and a prolonged APTT (92.2 s), FVIII inhibitors were found to be as high as 60.0 Bethesda Units. Initial treatments with methylprednisolone 200 mg/d were started but new hemorrhagic manifestation occurred and hisbiological indexes were not good. Then the patient was treated with intravenous pulse corticosteroids (methylprednisolone 500 mg/d), intravenous cyclophosphamide, and also plasma and prothrombin complex infusion. Subsequently, FVIII activity returned within normal ranges, FVIII inhibitors decreased and clinical improvement was significantly obtained. The patient's condition kept stable till now.Hemorrhagic events due to production of antibodies directed against coagulation factors were rarely observed in SLE and attentions should be paid to the association between SLE and AHA.Bypass treatment was considered as the immediate antihemorrhagic treatment. Corticosteroid combined with immunosuppressor was recommended as the main therapy to eradicate the inhibitors. However we still lack the therapeutic guidelines and standardized treatment in patients of AHA with SLE at present.

[Increased receptor activator of nuclear factor kappa B ligand expressed on B10 cells in rheumatoid arthritis]

OBJECTIVE

To detect receptor activator of nuclear factor kappa B ligand (RANKL) expressed on B10 cells in rheumatoid arthritis (RA) and to evaluate the correlation between RANKL-producing B10 cells in RA and clinical features and laboratory parameters, trying to reveal the possible role of B10 cells in the pathogenesis of RA and the potential mechanism of impaired immunosuppressive capacities.

METHODS

25 RA patients and 20 healthy volunteers were enrolled. These RA patients did not received treatment with glucocorticoids, disease-modifying anti-rheumatic drug and biologics during the recent half of a year. The levels of RANKL-producing B10 cells were measured by flow cytometry (FCM) and polymerase chain reaction (PCR). The correlation between the frequencies of RANKL-producing B10 cells in RA and clinical data, laboratory parameters were analyzed. The role of tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) in inducing RANKL expression in B10 cells was evaluated by in vitro stimulation assay. Independent samples t test, Pearson and Spearman correlation were used for statistical analysis.

RESULTS

B10 cells were capable of producing RANKL at a low level in health controls. The frequencies of RANKL-producing B10 cells were markedly higher in RA patients than in health controls (3.65%±1.59% vs. 2.25%±0.68%, P<0.01). The frequencies of these cells correlated positively with RA tender joint counts, swollen joint counts and disease activity score in 28 joints (DAS28) (r=0.479, P=0.035; r=0.519, P=0.008; r=0.526, P=0.019). However, no correlation was found between these cells and RA patient age, disease duration, or the levels of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF) and anti-citrullinated peptide antibody (ACPA). After in vitro stimulation by TNF-α, but not IL-1β, B10 cells isolated from healthy donors demonstrated fundamentally upregulated expression of RANKL.

CONCLUSION

Our studies showed the frequencies of RANKL-producing B10 cells were markedly higher in RA patients, and their frequencies were positively correlated with RA tender joint counts, swollen joint counts and DAS28. These findings suggested that B10 cells might be involved in RA bone destruction.

Efficacy and safety of rituximab therapy for membranous nephropathy: a meta-analysis

OBJECTIVE

Membranous nephropathy (MN) is a leading cause of nephrotic syndrome in adults, but the treatment of MN remains controversial. Rituximab, a possible alternative treatment option, represented a new therapeutic hope for the treatment of membranous nephropathy (MN). We performed a meta-analysis to perform the efficacy and safety of rituximab therapy.

MATERIALS AND METHODS

Either randomized controlled trials (RCTs), cohort studies or case studies were eligible for review and were performed in Medline, Embase, Web of Science, Cochrane database with the computerized searches. The primary outcome measure was remissions and the endpoint outcomes. We assessed the following studies methodological quality independently by using the Cochrane Collaboration tool for assessing risk of bias scale. The primary meta-analyses were performed using fixed or random effects models due to a1n expected clinical diversity.

RESULTS

Five trials with a total of 351 patients were included. We found significant difference between rituximab and the placebo group on complete remissions rate (OR=1.6, 95%; CI=0.96, 2.66; I2 of 0% indicating no heterogeneity) and eGFR (MD=-0.69, 95% CI=-14.53, 0.73). The factors of remission and no remission MN patients who received treatment with rituximab on remission were proteinuria and albumin, which reported different (MD=7.20, 95% CI=-9.07, -5.33) (MD=10.70, 95% CI=7.23, 14.17). But remains high risk of infusion reactions (OR= 81.37, 95% CI=4.89, 1354.41). No evidence of significant risk of bias was reported.

CONCLUSIONS

Rituximab had a beneficial effect and remissions of proteinuria on MN during follow-up times, but some adverse events were still unknown. Taking consideration of long-term therapeutic side effects and dose of the drug, we suggest that rituximab might replace cyclophosphamide and steroids as first-line immunosuppressive therapy in MN patients.

Comprehensive analysis of the mitochondrial DNA diversity in Chinese cattle

Complete mitochondrial DNA D-loop sequences of 1105 individuals were used to assess the diversity of maternal lineages of cattle populations in China. In total, 250 taurine and 88 zebu haplotypes were identified. Five main haplogroups-T1a, T2, T3, T4 and T5-were identified in Bos taurus, whereas Bos indicus harbored two haplogroups-I1 and I2. Our results suggest that the distribution of T1a in Asia was concentrated mainly in the northeast region (northeast China, Korea and Japan); haplogroups T2, T3 and T4 were predominant in Chinese cattle; and T5 was sporadically detected in Mongolian and Pingwu cattle. In contrast to the widespread presence of I1, I2 was distributed only in southwestern China (Yunnan-Guizhou Plateau and the Tibet Autonomous Region) and Xinjiang Uygur Autonomous Region. This is the first time that all five taurine haplogroups and two zebu haplogroups have been found in Mongolian cattle. In addition, eight individuals in Tibetan cattle carried the Bos grunniens mtDNA type. The high mtDNA diversity (H = 0.904 ± 0.008) and the weak genetic structure among the 57 Chinese cattle breeds/populations are consistent with their complex historical background, migration route and ecological environment.

[De novo Assembly and Analysis of Sumac (Toxicodendron vernicifluum (Stokes) F.A. Barkley) Transcriptomes Provides Insights into the Biosynthesis of Urushiol]

Sumac is universally known for its abundance of raw lacquer. Toxicodendron vernicifluum (Stokes) F.A. Barkley is one of the widely distributed native sumac cultivars. To accelerate sumac breeding for more prolific, high-quality, and robust cultivars, it is essential to explore its lacquer metabolism. However, transcriptomic and genomic data available for sumac are still limited. In this study, we generated the transcriptomic profiles of triploid Toxicodendron vernicifluum CV. Dahongpao (Dahongpao) and diploid T. vernicifluum and Toxicodendron vernicifluum CV. Huoyanzi (Huoyanzi), with 87856 unigenes. About 53% of these unigenes were annotated using Nr, Swiss-Prot, Kyoto Encyclopedia of Genes and Genomes (KEGG), Cluster of Orthologous Groups (COG) and Gene Ontology (GO). We identified nine differentially expressed candidate genes associated with type III polyketide synthase formation, which is the first step in urushiol biosynthesis. Additionally, a number of simple sequence repeats (EST-SSRs) were identified in T. vernicifluum for further molecular marker-assisted breeding. This study is the first report of Toxicodendron species transcriptome.

[Comparison of clinical values in decision making between cone beam CT and conventional approach in furcation involvement of maxillary molar]

Objective: To compare the use of cone beam computed tomography (CBCT) and conventional approach (clinical probing and periapical radiograph) in assessing furcation involvement (FI) of maxillary molars and making treatment decisions. Methods: Thirty-two subjects were selected from the pool of patients at the Department of Periodontology, Tianjin Stomatology Hospital & Hospital of Stomatology, NanKai University from January 2015 to December 2016. All the patients have a diagnosis of generalized chronic periodontitis. Ninety-five maxillary molar with FI from the radiography database were analysed. Two doctors used conventional approach and CBCT images to assess FI and make treatment decision respectively. If the clinical and radiographic findings did not clearly indicate a distinct periodontal therapy, two treatment options were considered. Results: There was statistical difference of the FI diagnosis between traditional group and CBCT group assessment of the 95 molars (P=0.000). Thirty-five maxillary molars (36.8%, 17 patients) got two treatment recommendations by conventional approach but 7 (7.4%, 5 patients) by CBCT-based approach. When with the less invasive treatment recommendation, there was statistical difference between conventional approach and CBCT-based approach (P=0.001). An agreement was observed in 63.2% (60/95) of the teeth, while in another 29.5% (28/95) the CBCT-based treatment decision was more invasive than the conventional approach. When with the more invasive treatment recommendation, there was also statistical difference between two approaches (P=0.045). An agreement was observed in 86.3% (82/95) of the teeth, while in another 3.2% (3/95) the CBCT-based treatment decision was more invasive than the conventional approach. Conclusions: CBCT images of maxillary molars may provide detailed information of FI and a reliable basis for treatment decision.

Ferruginol induced apoptosis on SK-Mel-28 human malignant melanoma cells mediated through P-p38 and NF-κB

In the present investigation, the antitumor effect of ferruginol (FGL) in SK-Mel-28 human malignant melanoma cells was studied. To investigate the cytotoxic property of FGL, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used. Results revealed that prolonged treatment duration decreases the IC25, IC50, and IC75 concentrations of FGL. The cytotoxicity was further confirmed by lactate dehydrogenase assay. As evident from comet assay, FGL induces DNA damage in a dose-dependent manner. Annexin V and 7-ADD assays showed that FGL-induced DNA damage triggers apoptosis-mediated cell death as confirmed by caspase-3 activity assay. As seen through Western blotting, FGL increases phosphorylation of p38 and nuclear translocation of NF-κB. Further, it was observed that p38 phosphorylation is responsible for NF-κB translocation to the nucleus. Further, inhibition of p38 phosphorylation and translocation of NF-κB decrease caspase-3 activity. The above finding confirms that caspase-3 activation is mediated through P-p38 and nuclear translocation of NF-κB. The present findings indicate that FGL significantly suppresses the proliferation of SK-Mel-28 cells in a dose- and time-dependent manner through induction of apoptosis. Furthermore, FGL executes apoptosis through phosphorylation of key protein such as p38 and translocation of NF-κB into the nucleus.

[Comparison of lymphatic staining methods based on whole organ sections of laryngeal carcinoma]

Objective:To compare the diagnostic potential of HE staining, enzymatic histochemistry and immunohistochemistry in displaying lymphatic vessel of laryngeal carcinoma.Method：We recruited 3 patients who were pathologically diagnozed as laryngeal squamous cell carcinoma and were performed total laryngectomy in the First Affiliated Hospital of Shanxi Medical University from April to December 2016. According to the improved Kawamoto's Film Method, frozen specimens of whole laryngeal squamous cell carcinoma were made. Immunohistochemistry, using lymphatic endothelial cell specific marker D2-40, enzymatic histochemistry (5-nucleotidase) and HE staining were used to stain the frozen sections of laryngeal carcinoma. Then the staining results of lymphatic vessels in the specimens of laryngeal carcinoma were compared by the optical microscope. Result：The background of HE and D2-40 immunohistochemical staining were clear.5-Nase staining had a deeper background and more nonspecific staining. By immunohistochemistry,102（97.1%,102/105）blood vessels were identified, and 3(2.9%) were partly positive. While using 5-Nase,56（53,3%,56/105）blood vessels were identified. In 105 lumen structures that could not be clearly judged,95（90,5%）were positive by D2-40,while by 5-Nase staining,89（84.8%）were positive including a large number of glands.In addition, positive cells scattered in dots or clusters were observed in 5-Nase and D2-40 staining sections, but these cells or structures could not be identified by HE staining. Conclusion：D2-40 immunohistochemistry may have certain applied value in the study of lymphatic vessels associated with laryngeal carcinoma.

Hepatic glutamate transport and glutamine synthesis capacities are decreased in finished vs. growing beef steers, concomitant with increased GTRAP3-18 content

Hepatic glutamate uptake and conversion to glutamine is critical for whole-body N metabolism, but how this process is regulated during growth is poorly described. The hepatic glutamate uptake activities, protein content of system [Formula: see text] transporters (EAAC1, GLT-1) and regulatory proteins (GTRAP3-18, ARL6IP1), glutamine synthetase (GS) activity and content, and glutathione (GSH) content, were compared in liver tissue of weaned Angus steers randomly assigned (n = 8) to predominantly lean (growing) or predominantly lipid (finished) growth regimens. Steers were fed a cotton seed hull-based diet to achieve final body weights of 301 or 576 kg, respectively, at a constant rate of growth. Liver tissue was collected at slaughter and hepatic membranes fractionated. Total (75%), Na+-dependent (90%), system [Formula: see text]-dependent (abolished) glutamate uptake activity, and EAAC1 content (36%) in canalicular membrane-enriched vesicles decreased as steers developed from growing (n = 6) to finished (n = 4) stages, whereas Na+-independent uptake did not change. In basolateral membrane-enriched vesicles, total (60%), Na+-dependent (60%), and Na+-independent (56%) activities decreased, whereas neither system [Formula: see text]-dependent uptake nor protein content changed. EAAC1 protein content in liver homogenates (n = 8) decreased in finished vs. growing steers, whereas GTRAP3-18 and ARL6IP1 content increased and GLT-1 content did not change. Concomitantly, hepatic GS activity decreased (32%) as steers fattened, whereas GS and GSH contents did not differ. We conclude that hepatic glutamate uptake and GS synthesis capacities are reduced in livers of finished versus growing beef steers, and that hepatic system [Formula: see text] transporter activity/EAAC1 content is inversely proportional to GTRAP3-18 content.