An Enzyme Assay Kit for GABA Quantification in Plant Tissues

Gamma-aminobutyric acid (GABA) is an amino acid that has a role as a signaling molecule. In plants, its involvement in stress responses is widely investigated. A newly developed method of quantification of GABA is described in this chapter. The assay kit consisting of three bacterial enzymes enables easy but accurate measurement of GABA (~200 mg/mL) based on the serial enzymatic reaction leading to dye formation. The method was successfully applied to measure the GABA content in several plant tissues.

Utility of non-invasive liver fibrosis markers to predict the incidence of chronic kidney disease (CKD): A systematic review, meta-analysis, and meta-regression

BACKGROUND AND AIMS

Chronic kidney disease (CKD) and non-alcoholic fatty liver disease (NAFLD) share common risk factors and pathogenesis mechanisms. However, the association between the degree of liver fibrosis and the incidence of CKD remains unclear. This study aims to examine the utility of non-invasive fibrosis markers to predict the occurrence of CKD.

METHODS

Cochrane Library, Scopus, and Medline were searched up to May 20th, 2023 using combined keywords. Literature that analyzes FIB-4, NFS, and APRI to predict CKD incidence was included in this review. We used random-effect models of odds ratio (OR) with 95% confidence intervals (CI) to express the outcomes in this review.

RESULTS

Twenty-one studies were included. Our meta-analysis showed that high FIB-4 was associated with a higher incidence of CKD (OR 2.51; 95%CI: 1.87-3.37, p < 0.00001, I2 = 96%). Further regression analysis revealed that this association was significantly influenced by hypertension (p = 0.0241), NAFLD (p = 0.0029), and body mass index (BMI) (p = 0.0025). Our meta-analysis also showed that high NFS (OR 2.49; 95%CI: 1.89-3.30, p < 0.00001, I2 = 96%) and high APRI (OR 1.40; 95%CI: 1.14-1.72, p = 0.001, I2 = 26%) were associated with a higher incidence of CKD.

CONCLUSIONS

This study suggests that these non-invasive liver fibrosis markers can be routinely measured both in NAFLD patients and the general population to enable better risk stratification and early detection of CKD.

Liver Transaminase Concentrations in Children with Acute SARS-CoV-2 Infection

OBJECTIVE

To evaluate the relationship between SARS-CoV-2 infection and liver injury by comparing transaminase concentrations among children tested for SARS-CoV-2 and other respiratory viruses in pediatric emergency departments.

DESIGN & METHODS

Eligible children were <18 years with suspected SARS-CoV-2, tested using molecular approaches in emergency departments between March 7, 2020, and June 15, 2021 (Pediatric Emergency Research Network), and between August 6, 2020, and February 22, 2022 (Pediatric Emergency Research Canada). We compared aspartate (AST) and alanine aminotransferase (ALT) concentrations at presentation for SARS-CoV-2 and other respiratory viruses through a multivariate linear regression model, with the natural log of serum transaminase concentrations as dependent variables.

RESULTS

Of 16,892 enrolled children, 2,462 (14.6%) had transaminase concentrations measured; 4,318 (25.6%) were SARS-CoV-2 positive, and 3,932 (23.3%) were tested for additional respiratory viruses. Among study participants who had additional respiratory virus testing performed, the most frequently identified viruses were enterovirus/rhinovirus [8.7% (343/3,932)], respiratory syncytial virus [4.6% (181/3,932)], and adenovirus [2.6% (103/3,932)]. Transaminase concentrations were elevated in 25.6% (54/211) of children with isolated SARS-CoV-2 detection and 21.6% (117/541) of those with no virus isolated; P=0.25. In the multivariable model, isolated SARS-CoV-2 detection was not associated with elevated ALT (Odds Ratio (OR): 0.96; 95%Confidence Interval (CI): 0.84, 1.08) or AST (OR: 1.03; 95%CI: 0.92, 1.16) concentrations, with negative respiratory panel as the referent group. Ninety-day follow-up was completed in 82.2% (3,550/4,318) of SARS-CoV-2 positive children; no cases of new-onset liver disease were reported.

CONCLUSION

Among those tested, transaminase concentrations did not vary between SARS-CoV-2-positive children and those with a negative respiratory viral panel. In multivariate analysis, SARS-CoV-2 infection was not associated with increased initial transaminase concentrations compared to other respiratory viruses.

Etiologies and Outcomes of Transaminase Elevation > 1000 IU/L: A Systematic Review and Meta-Analysis

BACKGROUND

Among liver injury causes, few result in marked elevation of liver enzymes to a level > 1,000 international units per liter (IU/L). This review summarizes common etiologies of marked transaminase elevation and associated prognostic factors.

METHODS

We performed a comprehensive search on PubMed, EMBASE, Cochrane Library, and Google Scholar from inception through December 2022 using MOOSE guidelines for studies reporting frequency of etiologies of marked transaminase elevation. We used a proportion meta-analysis to pool frequencies with corresponding 95% confidence interval (CI). I² was used to adjudicate heterogeneity. We used CMA software for statistical analysis.

RESULTS

Seven relevant studies (n = 1608 patients) were included. The pooled frequency of ischemic hepatitis was 51% (95% CI 42-60%, I² = 91%), viral hepatitis was 13.1% (95% CI 9.7-17.6%, I² = 80%), toxins or drug-induced liver injury (DILI) was 13% (95% CI 8-18%, I² = 85%), and pancreaticobiliary-related injury was 7.8% (95% CI 4.4-13.6%, I² = 89%). Mortality was significantly higher in ischemic hepatitis versus other causes of marked transaminase elevation, with an odds ratio of 21 (95% CI 9.9-44.8, P value < 0.0001, I² = 64% Q 11.1).

DISCUSSION

This is the first meta-analysis to examine etiologies of marked transaminase elevation > 1000 IU/L. Liver ischemia is the most common cause, while other causes include DILI or toxins, viral hepatitis, and biliary pathologies. We found biliary pathologies to be the fourth most common cause. This is clinically relevant as it has been traditionally linked to a cholestatic pattern of liver injury. Being aware of this presentation may help prevent delayed or missed diagnoses and unnecessary testing.

Relationship between triglyceride-glucose index and aminotransferase among Royal Thai Army personnel 2017-2021: a serial cross-sectional study

BACKGROUND

Insulin resistance (IR) is a major pathogenesis of nonalcoholic fatty liver disease (NAFLD). The triglyceride-glucose (TyG) index has recently gained popularity to assess IR and NAFLD due to its simplicity and low cost. The aim of the current study was to evaluate the relationship between the TyG index and aminotransferase.

METHODS

A serial cross-sectional study was conducted among 232,235 Royal Thai Army (RTA) personnel aged 35-60 years from 2017-2021. Elevated aminotransferase was defined as ≥ 40 U/L and ≥ 35 U/L among males and females, respectively. A linear regression analysis between the TyG index and log-transformed aminotransferase was performed. High- and low-TyG index groups were divided according to Youden's index cut point for predicting elevated aminotransferase. Multivariable logistic analysis was also utilized to investigate the association between the TyG index and elevated aminotransferase.

RESULTS

The TyG index revealed a dose‒response relationship with log-transformed aminotransferase in both sexes and all age groups. The TyG index was positively associated with the prevalence of elevated aminotransferases. In comparison with the first TyG quartile (< 8.37), participants in the fourth quartile (> 9.23) had a higher chance for elevated ALT (AOR: 2.81, 95% CI: 2.71-2.90 for males and AOR: 4.01, 95% CI: 3.50-4.60 for females, P < 0.001 for both). In the fourth TyG quartile, the prevalence of elevated ALT was 47.8% and 40.2% in the participants aged 35-44 and male participants, respectively.

CONCLUSION

A high TyG index is a novel risk factor for elevated aminotransferase among RTA personnel. Those with a high TyG index should be screened for elevated aminotransferase, particularly males aged 35-44 years.

Evaluation of the Patient with Markedly Abnormal Liver Enzymes

Liver enzyme tests are very commonly ordered by physicians, and when they return as abnormal, they can pose a clinical challenge to the provider. Markedly abnormal liver enzymes indicate severe hepatic injury and require immediate evaluation. There are various causes for abnormal liver tests, including infectious, autoimmune, genetic, metabolic, drug, and vascular causes. An understanding of the patterns of aminotransferase and alkaline phosphatase elevations is useful in narrowing the differential diagnosis. A thorough history and physical examination, appropriate blood testing, and imaging are typically key to evaluating the patient with abnormal liver enzymes.

Biochemical characterization of plant aromatic aminotransferases

Aromatic aminotransferases (Aro ATs) are pyridoxal-5-phosphate (PLP)-dependent enzymes that catalyze the transamination reactions of an aromatic amino acid (AAA) or a keto acid. Aro ATs are involved in biosynthesis or degradation of AAAs and play important functions in controlling the production of plant hormones and secondary metabolites, such as auxin, tocopherols, flavonoids, and lignin. Most Aro ATs show substrate promiscuity and can accept multiple aromatic and non-aromatic amino and keto acid substrates, which complicates and limits our understanding of their in planta functions. Considering the critical roles Aro ATs play in plant primary and secondary metabolism, it is important to accurately determine substrate specificity and kinetic properties of Aro ATs. This chapter describes various methodologies of protein expression, purification and enzymatic assays, which can be used for biochemical characterization of Aro ATs.

Diabetes Mellitus May Exacerbate Liver Injury in Patients with COVID-19: A Single-Center, Observational, Retrospective Study

INTRODUCTION

The spread of coronavirus disease 2019 (COVID-19) is having a profound effect on global health. In this study, we investigated early predictors of severe prognosis from the perspective of liver injury and risk factors for severe liver injury in patients with COVID-19.

METHODS

We examined prognostic markers and risk factors for severe liver injury by analyzing clinical data measured throughout the course of the illness and the disease severity of 273 patients hospitalized for COVID-19. We assessed liver injury on the basis of aminotransferase concentrations and fibrosis-4 (FIB-4) index on admission, peak aminotransferase concentration during hospitalization, aminotransferase peak-to-average ratio, and albumin and total bilirubin concentrations. Furthermore, we analyzed age, aspartate aminotransferase (AST) concentrations, FIB-4 index on admission, hypertension, diabetes mellitus (DM), dyslipidemia, cerebral infarction, myocardial infarction, and body mass index as mortality risk factors.

RESULTS

We identified advanced age as a risk factor. Among biochemical variables, AST concentration and FIB-4 index on admission were associated with high mortality. AST on admission and peak AST during hospitalization were significantly higher in the non-surviving (n = 45) than the discharged group (n = 228). Multivariable Cox hazards analyses for mortality showed significant hazard ratios for age, peak AST, and FIB-4 index on admission (p = 0.0001 and 0.0108, respectively), but not in a model including AST and FIB-4 index on admission. Furthermore, the AST peak was significantly higher among non-surviving patients with DM than in those without DM.

CONCLUSIONS

We found that advanced age, high AST, and FIB-4 index on admission and a higher peak AST during hospitalization are risk factors for poor COVID-19 prognosis. Furthermore, DM was a risk factor for exacerbation of liver injury among non-surviving patients. The AST concentration and FIB-4 index should be assessed periodically throughout hospitalization, especially in patients with high AST values on admission and those with DM.

Updated upper limits of normal serum alanine aminotrasferase levels for screening metabolic dysfunction-associated fatty liver disease in obese children

BACKGROUND/PURPOSE

Alanine aminotransferase (ALT) is a cost-effective screening test for asymptomatic liver diseases. The aims of this study are to redefine the ULNs of ALT using the 2010-2012 Nutrition and Health Survey in Taiwan (NAHSIT) database and to determine whether the updated ULNs can better screen for metabolic dysfunction-associated fatty liver disease (MAFLD) in obese children.

METHODS

Reference data were obtained from 2895 NAHSIT participants (1442 boys, 1453 girls) aged 6-18 years. Participants with any of MAFLD-related metabolic risk factors, including overweight/obesity, elevated triglyceride, low high-density lipoprotein cholesterol and high fasting glucose, were excluded. This study compared the sensitivities of different ULNs of ALT for detecting MAFLD in our previously established cohort of obese children.

RESULTS

The ULNs of ALT defined as the 95th percentile in metabolically healthy NAHSIT participants were 23 IU/L for boys and 18 IU/L for girls. When using the updated ULNs, the percentages of elevated ALT levels were 13.0% in boys and 7.8% in girls of all NAHSIT participants. When using the updated ULNs of ALT to detect MAFLD in obese children, the sensitivity was 84.0% in boys and 74.3% in girls. In contrast, when using the conventional ALT cutoff (>40 IU/L), the sensitivity decreased to 61.4% in boys and 36.4% in girls.

CONCLUSION

After taking into account MAFLD-related metabolic risk factors, the ULNs of ALT are 23 IU/L for boys and 18 IU/L for girls in Taiwan. The updated ULNs may be better cutoffs for screening MAFLD in obese children.

Serum fibrinogen-like protein 1 as a novel biomarker in polycystic ovary syndrome: a case-control study

PURPOSE

To investigate the relationship between fibrinogen-like protein 1 (FGL-1) concentrations and various metabolic characteristics in patients with polycystic ovary syndrome (PCOS) and explore whether FGL-1 could be a predictive biomarker for PCOS.

METHODS

This case-control study included 136 patients with PCOS and 34 normal controls recruited in the Department of Endocrinology and Metabolism, Shanghai Tenth People's Hospital between May 2017 and June 2021. Anthropometric characteristics, metabolic parameters, and reproductive hormones were collected. Serum FGL-1 measurement was conducted using enzyme-linked immunosorbent assay (ELISA) kits.

RESULTS

Serum FGL-1 concentrations were higher in patients with PCOS than in control subjects in body mass index (BMI) subgroups, insulin resistance (IR) subgroups, and hepatic function subgroups, respectively. Serum FGL-1 concentrations were significantly associated with BMI, glycosylated hemoglobin A1c (HbA1c), fasting plasma glucose (FPG), homeostasis model assessment of insulin resistance (HOMA-IR), alanine aminotransferase (ALT), aspartate aminotransferase (AST), high-density lipoprotein cholesterol (HDL-c), and serum uric acid (SUA) in all individuals. The receiver operating characteristic (ROC) curve analysis revealed that the best cutoff value for FGL-1 levels to predict PCOS was 21.02 ng/ml with a sensitivity of 74.3% and a specificity of 70.6%. Both univariate and multiple logistic regressions indicated that the odds ratio (OR) for PCOS significantly increased in the subjects with high levels of FGL-1.

CONCLUSION

In our study, FGL-1 was associated with serum aminotransferase and various metabolic indexes. Moreover, the high risk of PCOS was independently associated with the increased FGL-1 levels, which suggested that FGL-1 could be a predictive biomarker for PCOS.

Bi-directional Relationship Between Celiac Disease and Liver Chemistries: A Systematic Review and Meta-Analysis

AIMS

Previous studies have reported conflicting results regarding prevalence of elevated LC (2-70%) in celiac disease (CD). This systematic review and meta-analysis assessed the prevalence of elevated LC at time of CD diagnosis and associated response to GFD. We also report the prevalence of CD in patients with unexplained elevation of LC.

METHODS

Studies assessing LC (aspartate aminotransferase [AST] and alanine aminotransferase [ALT]) in CD patients were eligible. Studies with < 50 cases or in pediatric populations were excluded.

RESULTS

In total, 20 studies assessing prevalence of elevated LC in 4,265 participants with newly diagnosed CD (mean age = 35.6 ± 6.5 years, 69.8% female) were included. Pooled prevalence of elevated LC was 18.7% (95% CI 13.8-24.8; I2 = 95%). Normalization of elevated LC was seen in 83.1% (95% CI 73.4-89.7; I2 = 79%, 11 studies) of patients after GFD. On meta-regression, age at CD diagnosis, gender, and Marsh grading were not associated with elevated LC. Among 979 participants (7 studies) with unexplained elevation of LC, pooled seroprevalence and biopsy-proven CD was 6.4% (95% CI 2.9-10.3, I2 = 71%) and 4.5% (95% CI 2.6-7.7, I2 = 67%), respectively.

CONCLUSION

Elevated LC are seen in approximately one-fifth of patients at CD diagnosis with majority normalizing after GFD. Age, gender, and degree of intestinal damage are not predictive of elevated LC. In the appropriate clinical scenario, liver tests should be serially monitored in CD reserving workup for additional causes after a trial of GFD. Patients with unexplained elevation of liver tests should be screened for celiac disease.

The Effects of Helicobacter Pylori Eradication on Liver Function and Metabolic Profile in Non-diabetic Non-alcoholic Steatohepatitis: A 5-year Randomized Clinical Trial

BACKGROUND: To evaluate the effects of Helicobacter pylori (HP) eradication on liver function tests (LFT) and fat content (LFC) in non-diabetic non-alcoholic steatohepatitis (NASH). METHODS: This randomized clinical trial included dyspeptic HP infected non-diabetic NASH participants. The intervention arm received HP eradication treatment, while the control arm did not get any HP treatment. In the meantime, the standard management of NASH was performed in both trial arms. Mean alterations in LFT were the primary outcome and the secondary outcomes included the mean changes in LFC and serum metabolic profile. The trial follow-up period was 5 years. RESULTS: 40 participants (female: 20), with a mean age of 41.58 (±12.31) years, were enrolled in the study. The HP eradication arm included 20 participants (female: 11) with a mean age of 40.25 (±10.59) years, and the control arm consisted of 20 individuals (female: 9) with a mean age of 42.90 (±13.97) years. The tests of within-subjects effects showed a significant decrease in mean serum alanine aminotransferase (ALT; P=0.007), triglyceride (TG; P=0.04), cholesterol (P=0.004), and fasting blood sugar (FBS; P<0.001), and an increase in high-density lipoprotein (HDL; P=0.04) in both research groups during the study period. The tests of between-subjects effects demonstrated a more significant decrement of FBS in HP eradicated patients than the controls (P=0.02). The reduction in waist circumference, aspartate aminotransferase (AST), ALT, alkaline phosphatase, triglyceride, cholesterol, low-density lipoprotein, insulin, and LFC were more prominent in the intervention group than the controls; however, these differences were not statistically significant. CONCLUSION: Adding HP eradication treatment to standard NASH treatment showed more therapeutic effect thanthe standard NASH treatment protocol alone regarding the decrement of FBS in participants with dyspeptic non-diabetic NASH. Considering the non-statistically significant improvement in other metabolic indices and LFT in this trial, further studies are recommended.

Coronavirus Disease 2019 and Liver Injury: A Retrospective Analysis of Hospitalized Patients in New York City

BACKGROUND AND AIMS

Coronavirus disease 2019 (COVID-19) is a global threat, affecting more than 100 million people and causing over 2 million deaths. Liver laboratory test abnormalities are an extrapulmonary manifestation of COVID-19, yet characterization of hepatic injury is incomplete. Our objective was to further characterize and identify causes of liver injury in patients with COVID-19.

METHODS

We conducted a retrospective cohort study of 551 patients hospitalized with COVID-19 at NewYork-Presbyterian Hospital/Columbia University Irving Medical Center between March 1, 2020 and May 31, 2020. We analyzed patient demographics, liver laboratory test results, vital signs, other relevant test results, and clinical outcomes (mortality and intensive care unit admission).

RESULTS

Abnormal liver laboratory tests were common on hospital admission for COVID-19 and the incidence increased during hospitalization. Of those with elevated serum alanine aminotransferase and/or alkaline phosphatase activities on admission, 58.2% had a cholestatic injury pattern, 35.2% mixed, and 6.6% hepatocellular. Comorbid liver disease was not associated with outcome; however, abnormal direct bilirubin or albumin on admission were associated with intensive care unit stay and mortality. On average, patients who died had greater magnitudes of abnormalities in all liver laboratory tests than those who survived. Ischemic hepatitis was a mechanism of severe hepatocellular injury in some patients.

CONCLUSIONS

Liver laboratory test abnormalities are common in hospitalized patients with COVID-19, and some are associated with increased odds of intensive care unit stay or death. Severe hepatocellular injury is likely attributable to secondary effects such as systemic inflammatory response syndrome, sepsis, and ischemic hepatitis.

Multicenter Analysis of Clinical Features and Prognosis of COVID-19 Patients with Hepatic Impairment

Background/Aims

Recent data indicate the presence of liver enzyme abnormalities in patients with coronavirus disease 2019 (COVID-19). We aimed to evaluate the clinical features and treatment outcomes of COVID-19 patients with abnormal liver enzymes.

Methods

We performed a retrospective, multicenter study of 874 COVID-19 patients admitted to five tertiary hospitals from February 20 to April 14, 2020. Data on clinical features, laboratory parameters, medications, and treatment outcomes were collected until April 30, 2020, and compared between patients with normal and abnormal aminotransferases.

Results

Abnormal aminotransferase levels were observed in 362 patients (41.1%), of which 94 out of 130 (72.3%) and 268 out of 744 (36.0%) belonged to the severe and non-severe COVID- 19 categories, respectively. The odds ratios (95% confidence interval) for male patients, patients with a higher body mass index, patients with severe COVID-19 status, and patients with lower platelet counts were 1.500 (1.029 to 2.184, p=0.035), 1.097 (1.012 to 1.189, p=0.024), 2.377 (1.458 to 3.875, p=0.001), and 0.995 (0.993 to 0.998, p>0.001), respectively, indicating an independent association of these variables with elevated aminotransferase levels. Lopinavir/ ritonavir and antibiotic use increased the odds ratio of abnormal aminotransferase levels after admission (1.832 and 2.646, respectively, both p<0.05). The median time to release from quarantine was longer (22 days vs 26 days, p=0.001) and the mortality rate was higher (13.0% vs 2.9%, p<0.001) in patients with abnormal aminotransferase levels.

Conclusions

Abnormal aminotransferase levels are common in COVID-19 patients and are associated with poor clinical outcomes. Multivariate analysis of patients with normal aminotransferase levels on admission showed that the use of lopinavir/ritonavir and antibiotics was associated with abnormal aminotransferase levels; thus, careful monitoring is needed.

The association between serum liver enzymes and cancer mortality

Interpreting levels of liver enzymes is often challenging because they may be influenced by metabolic processes beyond the liver. Given their pathophysiologic roles in inflammation and oxidative stress, higher levels of these enzymes may be associated with increased risk of mortality. However, studies have found inconsistent results. Thus, we examined the association of liver enzymes levels with cancer mortality in the general US adult population. We used the US National Health and Nutrition Examination Survey from 1999 to 2016. Kaplan-Meier survival curve comparisons were examined across quartiles of liver enzymes. Cox proportional hazards models were built to examine the relationship between cancer mortality and liver enzymes quartiles without and with adjustment for potential confounding factors. During the 338,882 person-years follow-up, 1059 participants had cancer-related deaths. There was a nonlinear U-shaped relationship between serum alanine and aspartate aminotransferase (ALT and AST) levels and cancer mortality. There was no relationship between cancer mortality and gamma-glutamyltransferase (GGT); however, each 10 IU/L increase in GGT after median was associated with 1% higher mortality risk (HR = 1.01; 95% CI = 1.00, 1.02; P = 0.001). Only subjects with high levels of alkaline phosphatase (ALP) had higher cancer mortality (HR = 1.63; 95CI = 1.30, 2.05; P < 0.001 and HR = 1.52; 95%CI = 1.20, 1.94; P = 0.001, respectively). Only the lowest and highest serum ALT and AST levels are associated with increased cancer mortality. For ALP, the relationship is present at higher levels. The association with GGT was not robust to different analyses. The mechanisms underlying the observed relationships need further exploration.

A Reliable Prognostic Marker for Liver Dysfunction in COVID-19 Infection

BACKGROUND In December 2019, COVID-19 emerged from China and spread to become a pandemic, killing over 1,350,000 up to November 18, 2020. Some patients with COVID-19 have abnormal liver function tests. We aimed to determine the clinical significance of liver chemistries in patients with COVID-19. METHODS We performed a cross-sectional study of 1044 consecutive patients with confirmed COVID-19 in two referral hospitals in Tehran, Iran, from February to April 2020. All cases were diagnosed by clinical criteria and confirmed by characteristic changes in the spiral chest computed tomography (CT) and nucleic acid testing of the nasopharyngeal samples. We evaluated the association between abnormal liver enzymes or function tests and survival, intensive care unit (ICU) admission and fatty liver changes in CT scans. RESULTS The mean age was 61.01 ± 16.77 years, and 57.68% were male. Of 495 patients with elevated alanine transaminase (ALT) levels, 194 had chest CT scans, in which fatty liver disease was seen in 38.1%. 41 patients (21.13%) had moderate to severe, and 33 (17.01%) had borderline fatty liver disease. Bilirubin, albumin, and partial thromboplastin time (PTT), along with other markers such as HCO₃, C-reactive protein (CRP), triglyceride, and length of admission, were significantly associated with ICU admission and mortality. Prothrombin time (PT), platelet count, and low-density lipoprotein (LDL) levels were also correlated with mortality. Fasting blood sugar (FBS) and pH were important indices in ICU admitted patients. CONCLUSION Liver function tests accurately predict a worse prognosis in patients with COVID-19. However, liver enzymes were only slightly increased in those who died or needed ICU admission and were not related to the fatty liver changes.

Snapshots along the catalytic path of KabA, a PLP-dependent aminotransferase required for kanosamine biosynthesis in Bacillus cereus UW85

Kanosamine is an antibiotic and antifungal monosaccharide. The kanosamine biosynthetic pathway from glucose 6-phosphate in Bacillus cereus UW85 was recently reported, and the functions of each of the three enzymes in the pathway, KabA, KabB and KabC, were demonstrated. KabA, a member of a subclass of the VI_β family of PLP-dependent aminotransferases, catalyzes the second step in the pathway, generating kanosamine 6-phosphate (K6P) using l-glutamate as the amino-donor. KabA catalysis was shown to be extremely efficient, with a second-order rate constant with respect to K6P transamination of over 10⁷ M^-1s^-1. Here we report the high-resolution structure of KabA in both the PLP- and PMP-bound forms. In addition, co-crystallization with K6P allowed the structure of KabA in complex with the covalent PLP-K6P adduct to be solved. Co-crystallization or soaking with glutamate or 2-oxoglutarate did not result in crystals with either substrate/product. Reduction of the PLP-KabA complex with sodium cyanoborohydride gave an inactivated enzyme, and crystals of the reduced KabA were soaked with the l-glutamate analog glutarate to mimic the KabA-PLP-l-glutamate complex. Together these four structures give a complete picture of how the active site of KabA recognizes substrates for each half-reaction. The KabA structure is discussed in the context of homologous aminotransferases.

The relative expression of hepatocellular and cholestatic liver enzymes in adult patients with liver disease

INTRODUCTION AND OBJECTIVES

Hepatocellular liver injury is characterized by elevations in serum alanine (ALT) and aspartate (AST) aminotransferases while cholestasis is associated with elevated serum alkaline phosphatase (ALP) levels. When both sets of enzymes are elevated, distinguishing between the two patterns of liver disease can be difficult. The aim of this study was to document the predicted ranges of serum ALP values in patients with hepatocellular liver injury and ALT or AST values in patients with cholestasis.

MATERIALS AND METHODS

Liver enzyme levels were documented in adult patients with various types and degrees of hepatocellular (non-alcoholic fatty liver disease, hepatitis B and C, alcohol and autoimmune hepatitis) and cholestatic (primary biliary cholangitis and primary sclerosing cholangitis) disease.

RESULTS

In 5167 hepatocellular disease patients with ALT (or AST) values that were normal, 1-5×, 5-10× or >10× elevated, median (95% CI) serum ALP levels were 0.64 (0.62-0.66), 0.72 (0.71-0.73), 0.80 (0.77-0.82) and 1.15 (1.0-1.22) fold elevated respectively. In 252 cholestatic patients with ALP values that were normal, 1-5× or >5× elevated, serum ALT (or AST) values were 1.13 (0.93-1.63), 2.47 (2.13-2.70) and 4.57 (3.27-5.63) fold elevated respectively. In 56 patients with concurrent diseases, ALP levels were beyond predicted values for their hepatitis in 38 (68%) and ALT (or AST) values beyond predicted values for their cholestatic disorder in 24 (43%).

CONCLUSIONS

These data provide health care providers with predicted ranges of liver enzymes in patients with hepatocellular or cholestatic liver disease and may thereby help to identify patients with concurrent forms of liver disease.

Predictors for incidence and remission of nonalcoholic fatty liver disease in obese children and adolescents

BACKGROUND/PURPOSE

The status of nonalcoholic fatty liver disease (NAFLD) can wax and wane over time in children. However, the factors affecting its incidence and remission remain elusive. We aimed to investigate NAFLD incidence, remission and predicting factors in obese children.

METHODS

Obese children aged 9-10 and 12-13 years were recruited from schools and followed up for 2 years. Liver ultrasonography was performed at baseline and Year 1. Alanine aminotransferase (ALT) concentrations were measured at baseline, Year 1 and Year 2. Elevated ALT was defined as above 26 U/L for boys and 22 U/L for girls. Four NAFLD susceptible genes, including PNPLA3, GCKR, TM6SF2 and MBOAT7, were genotyped. We analyzed the effects of these risk factors on the incidence and remission of NAFLD and elevated ALT.

RESULTS

At baseline, 86 of 440 (19.5%) subjects had ultrasonography-diagnosed NAFLD. At Year 1, of 264 subjects without NAFLD at baseline, 20 (7.6%) developed NAFLD. The baseline BMI z-score and increment in BMI z-score independently predicted incident NAFLD. Of the 68 subjects with NAFLD at baseline, 36 (52.9%) had NAFLD remission. Decrement in BMI z-score independently predicted NAFLD remission. The four studied NAFLD susceptible genes were not significantly associated with either the incidence or remission of NAFLD. In addition, changes in BMI z-score predicted the incidence and remission of elevated ALT from Year 1 to Year 2.

CONCLUSION

Obese children with increasing BMI are more likely to develop NAFLD and those with decreasing BMI are more likely to have NAFLD remission.

Gut bacterial deamination of residual levodopa medication for Parkinson's disease

Background

Parkinson’s disease (PD) is a progressive neurodegenerative disorder characterized by both motor and non-motor symptoms. Gastrointestinal tract dysfunction is one of the non-motor features, where constipation is reported as the most common gastrointestinal symptom. Aromatic bacterial metabolites are attracting considerable attention due to their impact on gut homeostasis and host’s physiology. In particular, Clostridium sporogenes is a key contributor to the production of these bioactive metabolites in the human gut.

Results

Here, we show that C. sporogenes deaminates levodopa, the main treatment in Parkinson’s disease, and identify the aromatic aminotransferase responsible for the initiation of the deamination pathway. The deaminated metabolite from levodopa, 3-(3,4-dihydroxyphenyl)propionic acid, elicits an inhibitory effect on ileal motility in an ex vivo model. We detected 3-(3,4-dihydroxyphenyl)propionic acid in fecal samples of Parkinson’s disease patients on levodopa medication and found that this metabolite is actively produced by the gut microbiota in those stool samples.

Conclusions

Levodopa is deaminated by the gut bacterium C. sporogenes producing a metabolite that inhibits ileal motility ex vivo. Overall, this study underpins the importance of the metabolic pathways of the gut microbiome involved in drug metabolism not only to preserve drug effectiveness, but also to avoid potential side effects of bacterial breakdown products of the unabsorbed residue of medication.

Patterns of transaminase elevation in rhabdomyolysis versus acetaminophen toxicity

BACKGROUND

Transaminase elevations can occur from liver injury or in the setting of rhabdomyolysis. The goal of this study is to evaluate indices that could differentiate acetaminophen toxicity from muscle injury in the setting of transaminase elevations.

METHODS

A retrospective chart review of consecutive cases reported to our regional poison center. Patients with transaminase (AST and ALT) elevation were grouped as those with acetaminophen exposure (AT) and those with elevated creatine phosphokinase (CPK) without evidence of acetaminophen exposure (RHB).

RESULTS

Of the 345 patients included in the study, elevated AST/ALT levels were attributed to rhabdomyolysis in 168 patients and attributed to acetaminophen toxicity in 177 patients. The median AST: ALT values also differed between groups, with patients in the RHB group had higher median ratios (p < 0.001). Using an AST: ALT value of 2.02 as a diagnostic cutoff produced a specificity of 0.52 (95% CI: 0.37, 0.64) and sensitivity of 0.84 (95% CI: 0.73, 0.94) for acetaminophen detection in the test dataset (N = 104).

CONCLUSIONS

Elevated transaminases due to liver injury from acetaminophen ingestion had a different pattern than elevated transaminases due to rhabdomyolysis. Lower AST:ALT ratios were found in acetaminophen cases, however, the specificity using a ratio threshold of ≤1 would be 83%.

Identification of a species-specific aminotransferase in Pediococcus acidilactici capable of forming α-aminobutyrate

During cheese ripening, the bacterial strain Pediococcus acidilactici FAM18098 produces the non-proteinogenic amino acid, α-aminobutyrate (AABA). The metabolic processes that lead to the biosynthesis of this compound are unknown. In this study, 10 P. acidilactici, including FAM18098 and nine Pediococcus pentosaceus strains, were screened for their ability to produce AABA. All P. acidilactici strains produced AABA, whereas the P. pentosaceus strains did not. The genomes of the pediococcal strains were sequenced and searched for genes encoding aminotransferases to test the hypothesis that AABA could result from the transamination of α-ketobutyrate. A GenBank and KEGG database search revealed the presence of a species-specific aminotransferase in P. acidilactici. The gene was cloned and its gene product was produced as a His-tagged fusion protein in Escherichia coli to determine the substrate specificity of this enzyme. The purified recombinant protein showed aminotransferase activity at pH 5.5. It catalyzed the transfer of the amino group from leucine, methionine, AABA, alanine, cysteine, and phenylalanine to the amino group acceptor α-ketoglutarate. Αlpha-ketobutyrate could replace α-ketoglutarate as an amino group acceptor. In this case, AABA was produced at significantly higher levels than glutamate. The results of this study show that P. acidilactici possesses a novel aminotransferase that might play a role in cheese biochemistry and has the potential to be used in biotechnological processes for the production of AABA.

A covalent small molecule inhibitor of glutamate-oxaloacetate transaminase 1 impairs pancreatic cancer growth

Metabolic programs are rewired in cancer cells to support survival and tumor growth. Among these, recent studies have demonstrated that glutamate-oxaloacetate transaminase 1 (GOT1) plays key roles in maintaining redox homeostasis and proliferation of pancreatic ductal adenocarcinomas (PDA). This suggests that small molecule inhibitors of GOT1 could have utility for the treatment of PDA. However, the development of GOT1 inhibitors has been challenging, and no compound has yet demonstrated selectivity for GOT1-dependent cell metabolism or selective growth inhibition of PDA cell lines. In contrast, potent inhibitors that covalently bind to the transaminase cofactor pyridoxal-5'-phosphate (PLP), within the active site of the enzyme, have been reported for kynurenine aminotransferase (KAT) and gamma-aminobutyric acid aminotransferase (GABA-AT). Given the drug discovery successes with these transaminases, we aimed to identify PLP-dependent suicide substrate-type GOT1 inhibitors. Here, we demonstrate that PF-04859989, a known KAT2 inhibitor, has PLP-dependent inhibitory activity against GOT1 and shows selective growth inhibition of PDA cell lines.

COVID-19 prognosis: what we know of the significance and prognostic value of liver-related laboratory parameters in SARS-CoV-2 infection

AIM

The present study aims to evaluate the prognostic value of liver-related laboratory parameters in COVID-19.

BACKGROUND

This is not the first nor will it be the last time that a member of the β-coronaviruses wages a full-scale war against human health. Notwithstanding atypical pneumonia being the primary symptom, the emergence of severe disease mainly resulting from the injury of non-pulmonary organs leaves no alternative, in some cases, other than a dreadful death.

METHODS

To provide a well-conceptualized viewpoint representing the prognostic values of liver-related laboratory parameters in COVID-19, a meta-analysis was performed with the calculation of mean difference and 95% confidence intervals of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (Bili), and albumin (Alb) in severe and non-severe COVID-19 patients.

RESULTS

While severe COVID-19 cases displayed higher values of ALT, AST, and Bili compared to non-severe patients (mean differences of 7.48, 12.07, and 3.07, respectively), the value of Alb was significantly lower in severe cases (mean differences of -6.15). There was also a correlation between alterations in all of the parameters; however, only correlations between ALT and Bili (R=0.98, p=0.0031), and Bili and Alb (R=-1, p=0.0012) were significant.

CONCLUSION

Abnormal values of liver-related examinations outwardly contribute to reflect the progression of the disease toward an unfavorable outcome. Therefore, careful scrutiny of these parameters will provide clinicians with invaluable information regarding SARS-CoV-2 infection, at least in terms of liver injury.

Purification, characterization and identification of rat brain cytosolic tyrosine transaminase as glutamine Transaminase-K

The current study was undertaken to investigate the spectrum of tyrosine transaminases enzymes in a cytosolic fraction of rat brain and to specifically purify and characterize a previously identified cytosolic brain enzyme possessing tyrosine/glyoxylate transaminase activity. Based upon extensive biochemical and immunochemical characterization of purified brain tyrosine/glyoxylate transaminase, we concluded the purified enzyme is glutamine transaminase-K (EC 2.6.1.64). This conclusion was based on: 1.) a concurrent enrichment in the tyrosine/glyoxylate and glutamine/phenylpyruvate transaminase activities during purification, 2.) demonstration of a co-substrate specificity for amino acids and α-keto acids that was highly consistent with published information for glutamine transaminase-K, 3.) results from detailed kinetic analysis, 4.) glutamine was a potent inhibitor of in vitro tyrosine/glyoxylate transamination, 5.) biochemical characterization, including pH optimum of 8.5 and spectrophotometric analysis and 6.) immunoanalytical analysis using a specific antiserum to rat renal glutamine transaminase-k. In addition, immunochemical characterization of a crude soluble extract of whole brain suggests that the in vitro tyrosine transaminase activity for several different α-keto acid co-substrates likely reflect the activity of glutamine transaminase-K. In conclusion, this investigation confirmed the presence of multiple tyrosine transaminase enzymes in a cytosolic extract of rat brain. Moreover, we concluded glutamine transaminase-K represents a predominant cytosolic enzyme in rat brain that's capable of catalyzing in vitro transamination of p-tyrosine and other aromatic amino acids, including the neurotransmitter precursors L-dopa and 5-hydroxytryptophan. The purified transaminase possesses a broad co-substrate specificity with preferential reactivity with α-keto acids derived from neutral aliphatic and aromatic amino acids. Lastly, we identified a heterogeneous regional distribution of tyrosine/glyoxylate transaminase (glutamine transaminase-K) in rat brain with a significantly higher level of in vitro activity in cerebellum.

The prognostic significance of serum gamma-glutamyltransferase levels and AST/ALT in primary hepatic carcinoma

Background

Blood counting and the liver function tests, as the routine examinations, can reflect the immune and nutritional status of the body, our aim is to assess the prognostic significance of serum gamma-glutamyltransferase (GGT) levels and AST/ALT in primary hepatic carcinoma.

Methods

Clinico-pathological data of 414 patients with primary hepatic carcinoma in the 1st Affiliated Hospital of Anhui Medical College between January 2007 to January 2014 was analyzed retrospectively in this study. Survival curves were described by Kaplan-Meier method and compared by Log-rank test, univariate and multivariate analysis were used to identify the prognostic factors.

Results

GGT was positively correlated with the tumor size(P = 0.000), tumor volume (P = 0.000), tumor volume percent (P = 0.004), TNM stage(P = 0.009), 1-year survival rate (P = 0.000), 3- years survival rate (P = 0.000) and 5-years survival rate(P = 0.000). The serum ALT/AST was significantly correlated with age (P = 0.047), tumor size(P = 0.002), tumor volume (P = 0.010), tumor volume percent (P = 0.005), TNM stage(P = 0.006), liver cirrhosis(P = 0.003), 3- years survival rate (P = 0.032) and 5-years survival rate(P = 0.000). The Kaplan-Meier curves showed that the patients with primary hepatic carcinoma had a longer time in the low GGT group and low AST/ALT group, showing a significant difference (P < 0.05). The univariate and multivariate analyses showed that TNM stage, differentiation grade, tumor volume, GGT and AST/ALT were independent factors for predicting overall survival rate of primary hepatic carcinoma patients.

Conclusions

GGT and AST/ALT were independent factors for predicting overall survival rate of primary hepatic carcinoma patients.

Comparison of aminotransferases of three Bacillus strains Bacillus altitudinis W3, Bacillus velezensis SYBC H47, and Bacillus amyloliquefaciens YP6 via genome analysis and bioinformatics

Aminotransferases have attracted considerable attention due to their extraordinary potential for the biosynthesis of chiral amines. Research on transaminase genes can facilitate their application to various fields. Herein, 89 putative aminotransferase genes potentially encoding useful biocatalysts were identified in three Bacillus strains genomes by genome annotation. Enzymes encoded by genes ota3, ota8, otae6, otae21, otaf1, otaf8, and otaf26 belong to pyridoxine 5'-phosphate-dependent enzyme class IV. These seven ω-aminotransferase genes are highly conserved according to phylogenetic tree and bioinformatics analyses, as are the putative lysine catalytic residues in the corresponding enzymes (ω-BPTA 1-7). The enzymes may possess similar activity to ω-aminotransferases from Arthrobacter sp. KNK 168. The potential application of these novel enzymes for the synthesis of medicinal amino compounds will be explored in future genetic engineering studies.

Perinatal outcomes of intrahepatic cholestasis of pregnancy in twin versus singleton pregnancies: is plurality associated with adverse outcomes?

PURPOSE

To determine the rate of obstetric and neonatal complications associated with intrahepatic cholestasis of pregnancy in twin versus singleton gestations.

METHODS

A retrospective cohort study including patients diagnosed with intrahepatic cholestasis of pregnancy at a single tertiary center between 2011 and 2016. Women were allocated into two groups: twin pregnancies (n = 56) and singleton pregnancies (n = 186). Obstetric and neonatal outcomes were compared between the two groups.

RESULTS

Intrahepatic cholestasis of pregnancy was diagnosed earlier in gestation in twin compared to singleton pregnancies (33.1 ± 2.8 vs. 35.1 ± 3.0 weeks, respectively; adjusted P < 0.001). Maternal serum levels of fasting total bile acids were significantly higher in twin pregnancies compared to singletons [27 (IQR 16-44) vs. 16 (IQR 10-26) µmol/L, respectively; P = 0.01]. None of the pregnancies in our cohort was complicated by fetal death. Apgar score at 5 min and umbilical artery and vein PH at delivery were comparable between the two groups.

CONCLUSIONS

Intrahepatic cholestasis of pregnancy in twin pregnancies appears to be more severe compared to singletons, as reflected by an earlier presentation and higher levels of maternal serum total bile acids. Large prospective studies are required to customize a management strategy specific for women with twin pregnancies and intrahepatic cholestasis of pregnancy.

Crystal structures of aminotransferases Aro8 and Aro9 from Candida albicans and structural insights into their properties

Aminotransferases catalyze reversibly the transamination reaction by a ping-pong bi-bi mechanism with pyridoxal 5'-phosphate (PLP) as a cofactor. Various aminotransferases acting on a range of substrates have been reported. Aromatic transaminases are able to catalyze the transamination reaction with both aromatic and acidic substrates. Two aminotransferases from C. albicans, Aro8p and Aro9p, have been identified recently, exhibiting different catalytic properties. To elucidate the multiple substrate recognition of the two enzymes we determined the crystal structures of an unliganded CaAro8p, a complex of CaAro8p with the PLP cofactor bound to a substrate, forming an external aldimine, CaAro9p with PLP in the form of internal aldimine, and CaAro9p with a mixture of ligands that have been interpreted as results of the enzymatic reaction. The crystal structures of both enzymes contains in the asymmetric unit a biologically relevant dimer of 55 kDa for CaAro8 and 59 kDa for CaAro9p protein subunits. The ability of the enzymes to process multiple substrates could be related to a feature of their architecture in which the active site resides on one subunit while the substrate-binding site is formed by a long loop extending from the other subunit of the dimeric molecule. The separation of the two functions to different chemical entities could facilitate the evolution of the substrate-binding part and allow it to be flexible without destabilizing the conservative catalytic mechanism.

Mining of aminotransferase gene ota3 from Bacillus pumilus W3 via genome analysis, gene cloning and expressing for compound bioamination

Aminotransferases are widely employed as biocatalysts to produce chiral amines and biologically active pharmaceuticals via asymmetric synthesis. In this study, transaminase genes in the Bacillus pumilus W3 genome were analysed, and gene ota3 encoding a putative (R)-selective transaminase was identified. The sequence of ota3 shares highest sequence identity (24.7%) with the first (R)-selective aminotransferase from Arthrobacter sp. KNK 168. Amino acid sequence and conserved domains analyses indicated that ω-BPAT encoded by ota3 belonged to the pyridoxal 5'-phosphate-dependent class IV (PLPDE_IV) superfamily. Both native and codon-optimised ω-BPAT genes were recombinantly expressed, and the purified proteins had a molecular mass of ~33.4 kDa. Furthermore, enantioselectivity tests with (S)- and (R)-α-phenethylamine revealed its (R)-selectivity. The optimal conditions for catalytic reaction were 45 °C and pH 7.0, and ω-BPAT retained stability at 20 °C and pH 7.0. Thus, ω-BPAT is a novel (R)-selective aminotransferase with great potential as a universal biocatalyst.

Association between obstructive sleep apnea and non-alcoholic fatty liver disease: a systematic review and meta-analysis

The relationship between obstructive sleep apnea (OSA) and non-alcoholic fatty liver disease (NAFLD) has been an issue of great concern. The primary purpose of this study was to determine the influence of OSA on the levels of liver enzymes including alanine transaminase (ALT) and aspartate transaminase (AST). The secondary purpose was to estimate the effect of OSA on the histological lesions of NAFLD, such as steatosis, lobular inflammation, ballooning degeneration, fibrosis, as well as NAFLD activity score (NAS). A systematic literature review using PubMed, Cochrane Library, Embase, and Ovid technologies from January 2007 to April 2017 was performed, and 9 studies (2272 participants) that met the selection criteria were evaluated. The present study demonstrated that OSA was related to ALT levels, but no significant correlation was found with AST levels. The subgroup analysis showed that the severity of OSA was associated with ALT levels, not with AST levels. The meta-regression analysis showed that age, sex, homeostasis model assessment, diabetes mellitus, body mass index, and waist circumference did not have a significant effect on the levels of ALT and AST. OSA was also found to be significantly correlated with steatosis, lobular inflammation, ballooning degeneration, and fibrosis, but was not correlated with NAS. OSA was independently related to the development and progression of NAFLD in terms of liver enzyme level and histological alterations. Future studies should investigate the possible relevant mechanisms, thereby guiding the exploration of potential therapeutic implications to prevent the progression of disease.

Metabolic engineering of indole pyruvic acid biosynthesis in Escherichia coli with tdiD

Background

Indole pyruvic acid (IPA) is a versatile platform intermediate and building block for a number of high-value products in the pharmaceutical and food industries. It also has a wide range of applications, such as drugs for the nervous system, cosmetics, and luminophores. Chemical synthesis of IPA is a complicated and costly process. Moreover, through the biosynthesis route employing l-amino acid oxidase, the byproduct hydrogen peroxide leads the degradation of IPA. TdiD, identified as a specific tryptophan aminotransferase, could be an alternative solution for efficient IPA biosynthesis.

Results

Escherichia coli strain W3110, which demonstrates basic production when supplied with tryptophan, was engineered for IPA biosynthesis. Several strategies were implemented to improve IPA production. First, through incorporating the codon-optimized tdiD into W3110, IPA levels increased from 41.54 ± 1.26 to 52.54 ± 2.08 mg/L. Second, after verifying the benefit of an increased phenylpyruvate pool, a YL03 strain was constructed based on a previously reported mutant strain of W3110 with a plasmid carrying aroF^fbr and pheA^fbr to further improve IPA production. The recombinant YL03 strain accumulated IPA at 158.85 ± 5.36 mg/L, which was 3.82-fold higher than that of the wild-type W3110 strain. Third, optimization of tdiD^co expression was carried out by replacing the Trc promoter with a series of constitutively active promoters along with increasing the plasmid copy numbers. The highest IPA production was observed in YL08, which achieved 236.42 ± 17.66 mg/L and represented a greater than 5-fold increase as compared to W3110. Finally, the effects of deletion and overexpression of tnaA on IPA biosynthesis were evaluated. The removal of tnaA led to slightly reduced IPA levels, whereas the overexpression of tnaA resulted in a considerable decline in production.

Conclusions

This study illustrates the feasibility of IPA biosynthesis in E. coli through tdiD. An efficient IPA producing strain, YL08, was developed, which provides a new possibility for biosynthesis of IPA. Although the final production was limited, this study demonstrates a convenient method of IPA synthesis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12934-016-0620-6) contains supplementary material, which is available to authorized users.

Metabolic and transcriptomic changes induced in host during hypersensitive response mediated resistance in rice against the Asian rice gall midge

BACKGROUND

An incompatible interaction between rice (Oryza sativa) and the Asian rice gall midge (AGM, Orseolia oryzae Wood-Mason), that is usually manifested through a hypersensitive response (HR), represents an intricate relationship between the resistant host and its avirulent pest. We investigated changes in the transcriptome and metabolome of the host (indica rice variety: RP2068-18-3-5, RP), showing HR when attacked by an avirulent gall midge biotype (GMB1), to deduce molecular and biochemical bases of such a complex interaction. Till now, such an integrated analysis of host transcriptome and metabolome has not been reported for any rice-insect interaction.

RESULTS

Transcript and metabolic profiling data revealed more than 7000 differentially expressed genes and 80 differentially accumulated metabolites, respectively, in the resistant host. Microarray data revealed deregulation of carbon (C) and nitrogen (N) metabolism causing a C/N shift; up-regulation of tetrapyrrole synthesis and down-regulation of chlorophyll synthesis and photosynthesis. Integrated results revealed that genes involved in lipid peroxidation (LPO) were up-regulated and a marker metabolite for LPO (azelaic acid) accumulated during HR. This coincided with a greater accumulation of GABA (neurotransmitter and an insect antifeedant) at the feeding site. Validation of microarray results by semi-quantitative RT-PCR revealed temporal variation in gene expression profiles.

CONCLUSIONS

The study revealed extensive reprogramming of the transcriptome and metabolome of RP upon GMB1 infestation leading to an HR that was induced by the generation and release of reactive oxygen species i.e. singlet oxygen and resulted in LPO-mediated cell death. RP thus used HR as a means to limit nutrient supply to the feeding maggots and simultaneously accumulated GABA, strategies that could have led to maggot mortality. The integrated results of transcript and metabolic profiling, for the first time, provided insights into an HR+ type of resistance in rice against gall midge.

Is ketogenic diet treatment hepatotoxic for children with intractable epilepsy?

PURPOSE

Long-term ketogenic diet (KD) treatment has been shown to induce liver steatosis and gallstone formation in some in vivo and clinical studies. The aim of this retrospective study was to evaluate the hepatic side effects of KD in epileptic children.

METHOD

A total of 141 patients (mean age: 7.1±4.1years [2-18 years], 45.4% girls), receiving KD at least one year for intractable epilepsy due to different diagnoses (congenital brain defects, GLUT-1 deficiency, West syndrome, tuberous sclerosis, hypoxic brain injury, etc.) were included in the study. Serum triglyceride, cholesterol, aminotransferase, bilirubin, protein and albumin levels and abdominal ultrasonography were recorded before and at 1, 3, 6, and 12 months following after diet initiation.

RESULTS

The mean duration of KD was 15.9±4.3months. At one month of therapy, three patients had elevated alanine and aspartate aminotransferase levels. These patients were receiving ketogenic diet for Doose syndrome, idiopathic epilepsy and GLUT-1 deficiency. Hepatosteatosis was detected in three patients at 6 months of treatment. Two of these patients were treated with KD for the primary diagnosis of tuberous sclerosis and one for Landau Kleffner syndrome. Cholelithiasis was detected in two patients at 12 months of treatment. They were receiving treatment for West syndrome and hypoxic brain injury sequelae.

CONCLUSION

Long-term ketogenic diet treatment stimulates liver parenchymal injury, hepatic steatosis and gallstone formation. Patients should be monitored by screening liver enzymes and abdominal ultrasonography in order to detect these side effects.

The auxins, IAA and PAA, are synthesized by similar steps catalyzed by different enzymes

One of the fundamental plant growth substances, indole-3-acetic acid (IAA), belongs to a class of phytohormones known as auxins. The main IAA biosynthesis pathway involves the conversion of tryptophan to indole-3-pyruvic acid, which is in turn converted to IAA. The two enzymes responsible for these conversions, members of the TAA1 and YUCCA gene families, respectively, have recently been implicated in the synthesis of another auxin, phenylacetic acid (PAA). While there is some evidence to support this theory, there are also some concerns. Here we address the question: to what extent does the TAA1/YUCCA system contribute to the biosynthesis of PAA? In addition, we highlight the importance of measuring auxin metabolites and conjugates in addressing such questions.

Kynurenine aminotransferase 3/glutamine transaminase L/cysteine conjugate beta-lyase 2 is a major glutamine transaminase in the mouse kidney

Background

Kynurenine aminotransferase 3 (KAT3) catalyzes the transamination of Kynurenine to kynurenic acid, and is identical to cysteine conjugate beta-lyase 2 (CCBL2) and glutamine transaminase L (GTL). GTL was previously purified from the rat liver and considered as a liver type glutamine transaminase. However, because of the substrate overlap and high sequence similarity of KAT3 and KAT1, it was difficult to assay the specific activity of each KAT and to study the enzyme localization in animals.

Methods

KAT3 transcript and protein levels as well as enzyme activity in the liver and kidney were analyzed by regular reverse transcription-polymerase chain reaction (RT-PCR), real time RT-PCR, biochemical activity assays combined with a specific inhibition assay, and western blotting using a purified and a highly specific antibody, respectively.

Results

This study concerns the comparative biochemical characterization and localization of KAT 3 in the mouse. The results showed that KAT3 was present in both liver and kidney of the mouse, but was much more abundant in the kidney than in the liver. The mouse KAT3 is more efficient in transamination of glutamine with indo-3-pyruvate or oxaloacetate as amino group acceptor than the mouse KAT1.

Conclusions

Mouse KAT3 is a major glutamine transaminase in the kidney although it was named a liver type transaminase.

General significance

Our data highlights KAT3 as a key enzyme for studying the nephrotoxic mechanism of some xenobiotics and the formation of chemopreventive compounds in the mouse kidney. This suggests tissue localizations of KAT3/GTL/CCBL2 in other animals may be carefully checked.

•

Mouse kynurenine aminotransferase 3 (KAT3) was specifically inhibited by methionine.

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Mouse KAT3 is more abundant in the kidney than in the liver.

•

Mouse KAT3 is a major glutamine transaminase in the kidney although it was named a liver transaminase.

Biochemical Profile of Nonalcoholic Fatty Liver Disease Patients in Eastern India with Histopathological Correlation

Aminotransferase assay is often used as a screening test as well as an endpoint for resolution of disease in nonalcoholic fatty liver disease (NAFLD). Aim of the study was to evaluate the relationship of transaminase level with metabolic variables and histology in NAFLD. Single center observational study was conducted in a gastroenterology clinic at Cuttack in coastal Odisha. Subjects were consecutive patients presenting with functional bowel disease and undergoing abdominal sonography. All participants were evaluated for the presence of metabolic syndrome (MS), insulin resistance, liver function test and lipid profile. Various parameters were compared between NAFLD subjects and controls. 53.5 % of NAFLD had normal serum transaminases, whereas 20.8 % of healthy controls had transaminitis. NAFLD patients had significantly higher BMI, fasting plasma glucose, serum transaminases, serum triglycerides, serum insulin and homeostatic model assessment (HOMA) IR than controls. NAFLD patients who had transaminitis had significantly higher incidence of MS and higher mean HOMA IR than those without. There was no significant difference in histopathological features between NAFLD with and without transaminitis. To conclude, over half of NAFLD subjects do not have transaminitis while transaminitis is present in a fifth of healthy people without fatty liver. Hence serum transaminase should not be used as screening test for NAFLD. NAFLD patients with transaminitis had a higher incidence of MS and insulin resistance than those without. However, there was no significant difference in histopathological features between these two groups.

Evaluation of aminotransferase abnormality in dengue patients: A meta analysis

Dengue virus is a type of flavivirus transmitted by Aedes mosquitoes. The symptoms of infection by this virus range from asymptomatic or mild symptomatic dengue fever (DF) to dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS). Significant abnormality in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) has been shown in a large number of dengue infection cases and to be indicator for liver injury provided that there are no other combined infections or liver injury. This study aims to assess the abnormal levels of liver aminotransferase in dengue patients. The related literature was searched in multiple databases, including PubMed, Embase, Google Scholar and Cochrane Library. The literature was selected through strict inclusion and exclusion criteria, and the quantitative synthesis of the liver aminotransferase abnormality was performed with R software. The fixed or random effects model was employed based on the results of the statistical test for homogeneity. In total, 15 studies were included. The proportion of AST abnormality with 95% confidence interval (95% CI) was 0.80 (95% CI: 0.56-0.92) in DHF patients and 0.75 (95% CI: 0.63-0.84) in DF patients; the proportion of ALT abnormality was 0.54 (95% CI: 0.34-0.73) in DHF patients and 0.52 (95% CI: 0.41-0.63) in DF patients. Serum ALT and AST levels may be indicators for evaluating liver injury in dengue infection and for diagnosis and treatment effect.

Heterologous Expression and Characterization of Mimosinase from Leucaena leucocephala

Heterologous expression of eukaryotic genes in bacterial system is an important method in synthetic biology to characterize proteins. It is a widely used method, which can be sometimes quite challenging, as a number of factors that act along the path of expression of a transgene to mRNA, and mRNA to protein, can potentially affect the expression of a transgene in a heterologous system. Here, we describe a method for successful cloning and expression of mimosinase-encoding gene from Leucaena leucocephala (leucaena) in E. coli as the heterologous host. Mimosinase is an important enzyme especially in the context of metabolic engineering of plant secondary metabolite as it catalyzes the degradation of mimosine, which is a toxic secondary metabolite found in all Leucaena and Mimosa species. We also describe the methods used for characterization of the recombinant mimosinase.

Acute Hepatic Phenotype of Wilson Disease: Clinical Features of Acute Episodes and Chronic Lesions Remaining in Survivors

BACKGROUND AND AIMS

Wilson disease (WD) is an inherited disorder of copper metabolism, and an international group for the study of WD (IGSW) has proposed three phenotypes for its initial presentation: acute hepatic, chronic hepatic, and neurologic phenotypes. Characterization of the acute hepatic phenotype may improve our understanding of the disease.

METHODS

Clinical features of 10 WD patients with the acute hepatic phenotype and characteristics of chronic lesions remaining in survivors were assessed by the European Association for the Study of the Liver (EASL) guidelines.

RESULTS

All six patients younger than 30 years had survived an acute episode of hemolytic anemia with residual liver disease of cirrhosis or chronic hepatitis. The acute episode was self-limiting in two of the four patients over the age of 30 years and progressed to acute liver failure in the other two patients. One of the two survivors had residual liver disease of chronic hepatitis, while the other had chronic hepatitis and neurologic disease. Neurologic disease remained in a patient who successfully received a liver transplantation. During acute episodes, serum levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) changed rapidly along with anemia. Liver-specific ALT levels were age-dependently correlated with hemoglobin (Hb) concentrations. Enzyme reduction was milder for AST than ALT, which resulted in a high AST/ALT ratio in the anemic stage. The anemic stage in two patients transformed to acute liver failure.

CONCLUSIONS

All survivors of an acute episode of the acute hepatic phenotype had residual liver disease or both liver and neurologic diseases. The rapid changes in liver enzymes during the acute episode and the liver and neurologic diseases remaining in survivors may provide a better understanding of WD.

Functional roles of a predicted branched chain aminotransferase encoded by the LkBAT1 gene of the yeast Lachancea kluyveri

Branched chain amino acid aminotransferases (BCATs) catalyze the last step of the biosynthesis and the first step of the catabolism of branched chain amino acids. In Saccharomyces cerevisiae, BCATs are encoded by the ScBAT1 and ScBAT2 paralogous genes. Analysis of Lachancea kluyveri genome sequence, allowed the identification of the LkBAT1 locus, which could presumably encode a BCAT. A second unlinked locus (LkBAT1bis), exhibiting sequence similarity to LkBAT1 was also identified. To determine the function of these putative BCATs, L. kluyveri mutant strains lacking LkBAT1, LkBAT1bis or both genes were generated and tested for VIL metabolism. LkBat1 displayed branched chain aminotransferase activity and is required for VIL biosynthesis and catabolism. However, Lkbat1Δ mutant is a valine and isoleucine auxotroph and a leucine bradytroph indicating that L. kluyveri harbors an alternative enzyme(s) involved in leucine biosynthesis. Additionally, heterologous reciprocal gene complementation between S. cerevisiae and L. kluyveri orthologous LkBAT1, ScBAT1 and ScBAT2 genes, confirmed that the mitochondrial LkBat1 functions as BCAT in S. cerevisiae, restoring wild type phenotype to the ScBAT1 null mutant. Conversely, LkBAT1bis did not display a role in BCAAs metabolism. However, when ethanol was used as carbon source, deletion of LkBAT1bis in an Lkbat1Δ null strain resulted in an extended 'lag' growth phase, pointing to a potential function of LkBAT1 and LkBAT1bis in the aerobic metabolism of L. kluyveri. These results confirm the BCAT function of LkBAT1 in L. kluyveri, and further support the proposition that the BCAT function in ancestral-type yeasts has been distributed in the two paralogous genes present in S. cerevisiae.

Hepatocellular Carcinoma Risk of Compensated Cirrhosis Patients with Elevated HBV DNA Levels according to Serum Aminotransferase Levels

Sometimes, hepatitis B virus (HBV)-related cirrhotic patients with normal aminotransferase levels are closely followed-up for the elevation of aminotransferase levels instead of prompt antiviral therapy (AVT). We analyzed the long-term hepatocellular carcinoma (HCC) risk according to the aminotransferase levels in a retrospective cohort of 1,468 treatment-naïve, HBV-related, compensated cirrhosis patients with elevated HBV DNA levels (≥ 2,000 IU/mL). Based on aminotransferase levels, patients were categorized into normal (< 40 U/L, n = 364) and elevated group (≥ 40 U/L, n = 1,104). During a median of 5.3 yr of follow-up (range: 1.0-8.2 yr), HCC developed in 296 (20%) patients. The 5-yr cumulative HCC incidence rate was higher in patients with elevated aminotransferase level, but was not low in normal aminotransferase level (17% vs. 14%, P = 0.004). During the follow-up, 270/364 (74%) patients with normal aminotransferase levels experienced elevation of aminotransferase levels, and AVT was initiated in 1,258 (86%) patients. Less patients with normal aminotransferase levels received AVT (70% vs. 91%, P < 0.001) and median time to start AVT was longer (17.9 vs. 2.4 months, P < 0.001). AVT duration was an independent factor associated with HCC, and median duration of AVT was shorter (4.0 vs. 2.6 yr, P < 0.001) in patients with normal aminotransferase levels. The HCC risk of compensated cirrhosis patients with normal aminotransferase level is not low, and AVT duration is associated with lowered HCC risk, indicating that prompt AVT should be strongly considered even for those with normal aminotransferase levels.

Structural basis for the relaxed substrate selectivity of Leishmania mexicana broad specificity aminotransferase

Leishmania species are early branching eukaryotic parasites that cause difficult-to-treat tissue-damaging diseases known as leishmaniases. As a hallmark of their parasitic lifestyle, Leishmaniae express a number of aminotransferases that are involved in important cellular processes and exhibit broader substrate specificity than their mammalian host's counterparts. Here, we have determined the crystal structure of the broad specificity aminotransferase from Leishmania mexicana (LmexBSAT) at 1.91Å resolution. LmexBSAT is a homodimer and belongs to the α-branch of family-I aminotransferases. Despite the fact that the protein was crystallized in the absence of substrates and has lost the pyridoxal-5'-phosphate (PLP) cofactor during crystallization, the structure resembles the closed, ligand-bound form of related enzymes such as chicken cytosolic aspartate aminotransferase. Its broader substrate specificity seems to be rooted in increased flexibility of a substrate-binding arginine (R291) and the interactions of this residue with the N-terminus of the second chain of the dimer.

Pen and Pal are nucleotide-sugar dehydratases that convert UDP-GlcNAc to UDP-6-deoxy-D-GlcNAc-5,6-ene and then to UDP-4-keto-6-deoxy-L-AltNAc for CMP-pseudaminic acid synthesis in Bacillus thuringiensis

CMP-pseudaminic acid is a precursor required for the O-glycosylation of flagellin in some pathogenic Gram-negative bacteria, a process known to be critical in bacterial motility and infection. However, little is known about flagellin glycosylation in Gram-positive bacteria. Here, we identified and functionally characterized an operon, named Bti_pse, in Bacillus thuringiensis israelensis ATCC 35646, which encodes seven different enzymes that together convert UDP-GlcNAc to CMP-pseudaminic acid. In contrast, Gram-negative bacteria complete this reaction with six enzymes. The first enzyme, which we named Pen, converts UDP-d-GlcNAc to an uncommon UDP-sugar, UDP-6-deoxy-D-GlcNAc-5,6-ene. Pen contains strongly bound NADP(+) and has distinct UDP-GlcNAc 4-oxidase, 5,6-dehydratase, and 4-reductase activities. The second enzyme, which we named Pal, converts UDP-6-deoxy-D-GlcNAc-5,6-ene to UDP-4-keto-6-deoxy-L-AltNAc. Pal is NAD(+)-dependent and has distinct UDP-6-deoxy-d-GlcNAc-5,6-ene 4-oxidase, 5,6-reductase, and 5-epimerase activities. We also show here using NMR spectroscopy and mass spectrometry that in B. thuringiensis, the enzymatic product of Pen and Pal, UDP-4-keto-6-deoxy-L-AltNAc, is converted to CMP-pseudaminic acid by the sequential activities of a C4″-transaminase (Pam), a 4-N-acetyltransferase (Pdi), a UDP-hydrolase (Phy), an enzyme (Ppa) that adds phosphoenolpyruvate to form pseudaminic acid, and finally a cytidylyltransferase that condenses CTP to generate CMP-pseudaminic acid. Knowledge of the distinct dehydratase-like enzymes Pen and Pal and their role in CMP-pseudaminic acid biosynthesis in Gram-positive bacteria provides a foundation to investigate the role of pseudaminic acid and flagellin glycosylation in Bacillus and their involvement in bacterial motility and pathogenicity.

Effects of pyridoxine on growth performance and plasma aminotransferases and homocysteine of white pekin ducks

A dose-response experiment with seven supplemental pyridoxine levels (0, 0.66, 1.32, 1.98, 2.64, 3.30, and 3.96 mg/kg) was conducted to investigate the effects of pyridoxine on growth performance and plasma aminotransferases and homocysteine of White Pekin ducks and to estimate pyridoxine requirement for these birds. A total of 336 one-day-old male White Pekin ducks were divided to 7 experimental treatments and each treatment contained 8 replicate pens with 6 birds per pen. Ducks were reared in raised wire-floor pens from hatch to 28 d of age. At 28 d of age, the weight gain, feed intake, feed/gain, and the aspartate aminotransferase, alanine aminotransferase, and homocysteine in plasma of ducks from each pen were all measured. In our study, the pyridoxine deficiency of ducks was characterized by growth depression, decreasing plasma aspartate aminotransferase activity and increasing plasma homocysteine. The ducks fed vitamin B₆-deficient basal diets had the worst weight gain and feed/gain among all birds and this growth depression was alleviated (p<0.05) when pyridoxine was supplemented to basal diets. On the other hand, plasma aspartate aminotransferase and homocysteine may be the sensitive indicators for vitamin B₆ status of ducks. The ducks fed basal diets had much lower aspartate aminotransferase activity and higher homocysteine level in plasma compared with other birds fed pyridoxine-supplemented diets (p<0.05). According to quadratic regression, the supplemental pyridoxine requirements of Pekin ducks from hatch to 28 days of age was 2.44 mg/kg for feed/gain and 2.08 mg/kg for plasma aspartate aminotransferase and the corresponding total requirements of this vitamin for these two criteria were 4.37 and 4.01 mg/kg when the pyridoxine concentration of basal diets was included, respectively. All data suggested that pyridoxine deficiency could cause growth retardation in ducks and the deficiency of this vitamin could be indicated by decreasing plasma aspartate aminotransferase activity and increasing plasma homocysteine.

Effect of vitamin E supplementation on aminotransferase levels in patients with NAFLD, NASH, and CHC: results from a meta-analysis

OBJECTIVE

The antioxidant vitamin E has been extensively employed to treat chronic liver diseases. The aim of this study was to assess the effect of vitamin E supplementation in lowering alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels in patients with nonalcoholic fatty liver disease (NAFLD), nonalcoholic steatohepatitis (NASH), and chronic hepatitis C (CHC).

METHODS

We searched all publications in PubMed, Web of Science, and Cochrane Library databases up to June 2013. In total, eight articles met the eligibility criteria, among which, two studies about NAFLD, four studies about NASH, and three studies about CHC, were identified and included in the meta-analysis.

RESULTS

According to standardized mean difference and 95% confidence interval, 12.19 (-4.08 to 28.46) for ALT and 6.84 (-3.18 to 16.86) for AST in patients with NAFLD, 4.54 (1.62-7.46) for ALT and 3.55 (1.39-5.71) for AST in patients with NASH, and 0.61 (0.20-1.02) for ALT and 0.68 (0.07-1.29) for AST in patients with CHC, vitamin E supplementation could optimize ALT and AST levels in patients with NASH and CHC, although it was not statistically significantly associated with reduced ALT and AST levels in patients with NAFLD.

CONCLUSION

To summarize, the evidence currently available supported the theory that vitamin E supplementation can optimize aminotransferase levels for patients with NAFLD, NASH, and CHC, and more well-designed, large-scale clinical trials are encouraged to examine the therapeutic effect of vitamin E for these disorders.

Hepatitis E virus and serum level aminotransferases in blood donors

BACKGROUND

Hepatitis E virus (HEV) infection is a self-limiting viral infection that can lead to severe complications and death. In different regions the epidemiology of this infection varies. In this study we evaluated the seroepidemiology of hepatitis E infection in Jahrom, a city in southern Iran.

METHODS

This was a cross-sectional descriptive study of serum samples from 477 subjects, including 30 females and 447 males. HEV immunoglobulin G (IgG) and immunoglobulin M (IgM) were measured by enzyme-linked immunosorbent assays (ELISA). Alanine transaminase (ALT) and aspartate transaminase (AST) levels were also determined. Four hundred forty-seven subjects were male and 30 were female. Subjects were classified by age and sex.

RESULTS

One woman (3.3%) and 25 men (5.5%) were positive for HEV antibodies (IgG and/or IgM). There was found an association between serum level of aminotransferases and seropositivity for HEV.

CONCLUSION

The result of this study indicates that HEV is an etiological factor for hepatitis in this area of IRAN. The cost benefit of active immunization in endemic regions should be evaluated because an outbreak could have tragic consequences.

Persistent hypertransaminasemia in asymptomatic children: A stepwise approach

We aimed to examine the major causes of isolated chronic hypertransaminasemia in asymptomatic children and develop a comprehensive diagnostic flow diagram. A MEDLINE search inclusive of publications throughout August 2012 was performed. We found only a small number of publications that had comprehensively investigated this topic. Consequently, it was difficult to construct a diagnostic flowchart similar to those already available for adults. In children, a “retesting panel” prescription, including gamma-glutamyl transpeptidase and creatine kinase in addition to aminotransferases, is considered a reasonable approach for proficiently confirming the persistence of the abnormality, ruling out cholestatic hepatopathies and myopathies, and guiding the subsequent diagnostic steps. If re-evaluation of physical and historical findings suggests specific etiologies, then these should be evaluated in the initial enzyme retesting panel. A simple multi-step diagnostic algorithm incorporating a large number of possible pediatric scenarios, in addition to the few common to adults, is available. Accurately classifying a child with asymptomatic persistent hypertransaminasemia may be a difficult task, but the results are critical for preventing the progression of an underlying, possibly occult, condition later in childhood or during transition. Given the high benefit/cost ratio of preventing hepatic deterioration, no effort should be spared in diagnosing and properly treating each case of persistent hypertransaminasemia in pediatric patients.

Relationship between serum adiponectin and non-alcoholic steatohepatitis in young men

AIM: To investigate the relationship between serum adiponectin and non-alcoholic steatohepatitis (NASH) in young men.

METHODS: The body mass index (BMI), alanine aminotransferase, aspartate aminotransferase, total cholesterol (TCHO), triglyceride, high-density lipoprotein, low-density lipoprotein (LDL), fasting plasma glucose and fasting plasma insulin were examined in 64 NASH patients and 46 healthy controls. The levels of adiponectin and high molecular weight (HMW) adiponectin were determined by ELISA and Western blot. The data were analyzed using SPSS19.0.

RESULTS: The level of total adiponectin and the ratio of HMW to total adiponectin were decreased in men with NASH, compared with controls (total adiponectin: 0.92 ± 0.17 vs 1.02 ± 0.16, P < 0.01; HMW/total: 0.39 ± 0.14 vs 0.47 ± 0.11, P < 0.01). The level of total adiponectin was decreased with the increase in the severity of NASH. Furthermore, the level of total adiponectin inversely correlated with TCHO (r = -0.358, P < 0.01) and LDL (r =- 0.339, P < 0.05). The ratio of HMW to total adiponectin was inversely correlated with BMI (r = -0.279, P < 0.05), but positively correlated with HDL (r = 0.266, P < 0.05).

CONCLUSION: The level of total adiponectin and the ratio of HMW to total adiponectin are directly related to NASH in young men. Adiponectin may play an important role in the development of NASH.