[Effects of different types of intraocular lens implantation on patient's visual quality and function after phacoemulsification]

Objective: To explore the effects of different types of intraocular lens (IOL) implantation on patient's visual quality and function after phacoemulsification. Methods: The clinical data of patients with monocular cataract who underwent phacoemulsification in the Department of Ophthalmology, People's Hospital Affiliated to Shandong First Medical University between December 2021 and May 2023 were retrospectively analyzed. According to the types of IOL, the patients were divided into monofocal group, bifocal group and depth of focus extension group. Three months later, uncorrected distance visual acuity (UCDVA), best corrected distance visual acuity (BCDVA), uncorrected intermediate visual acuity (UCIVA), best corrected intermediate visual acuity (BCIVA), uncorrected near visual acuity (UCNVA) and best corrected near visual acuity (BCNVA) were detected. Contrast sensitivity and total wavefront aberration were measured by visual function analyzer. Satisfaction with visual quality was evaluated by hospital-made satisfaction questionnaire. Results: A total of 92 patients were included, with 31 males and 61 females, and their age was (61.8±5.2) years. There were 43, 28 and 21 cases in monofocal group, bifocal group and depth of focus extension group, respectively. No statistically significant difference was found in clinical baseline data among the three groups. UCIVA, UCDVA, BCIVA and BCDVA in depth of focus extension group were 1.01±0.13, 0.92±0.18, 1.21±0.19 and 1.20±0.23, respectively, which were higher than those in monofocal group (0.62±0.12, 0.74±0.13, 1.02±0.17, 1.07±0.19, respectively) and bifocal group (0.67±0.15, 0.78±0.14, 1.01±0.16, 1.01±0.18, respectively), while absolute value of spherical equivalent [(-0.42±0.07) D] was lower than that in the other two groups [ (-0.49±0.05) D and (-0.45±0.08) D] (both P<0.05). UCNVA and BCNVA in bifocal group were 0.91±0.18 and 1.25±0.18, which were higher than those in depth of focus extension group (0.63±0.24 and 1.19±0.17) (both P<0.05). There were no significant differences in contrast sensitivity among the three groups under day vision or between monofocal group and bifocal group under night vision (all P>0.05), but the contrast sensitivity was higher in depth of focus extension group under night vision (3.0, 6.0, 12.0 c/d) than other two groups (all P<0.05). The score of ocular discomfort was the highest in bifocal group, followed by depth of focus extension group and monofocal group (both P<0.05). The score of visual interference in bifocal group was lower than that in monofocal group and depth of focus extension group (both P<0.05). The scores of subjective feeling in bifocal group and depth of focus extension group were higher than that in monofocal group (both P<0.05). The reading score was the highest in bifocal group, followed by depth of focus extension group and monofocal group (both P<0.05). There was no significant difference in total low-order aberration among the three groups (P=0.472). The total aberration and higher-order aberration [(0.74±0.35) μm and (0.41±0.12) μm] were the highest in monofocal group, followed by bifocal group [(0.61±0.21) μm and (0.22±0.09) μm] and depth of focus extension group [(0.46±0.13) μm and (0.06±0.09) μm] (all P<0.05). Conclusions: IOL implantation with depth of focus extension can enhance visual range, night vision and contrast sensitivity, and thus effectively improve postoperative visual quality and function in cataract patients. The bifocal IOL can better improve the patient's UCNVA and BCNVA, resulting in high satisfaction with visual quality.

[Research progress on the mechanism of action of heme oxygenase-1 regulating ferroptosis in non-alcoholic fatty liver disease]

Non-alcoholic fatty liver disease (NAFLD) has gradually become the most prevalent chronic liver disease in the world, but its pathogenesis has not been fully elucidated. Ferroptosis is a novel type of programmed cell death caused by iron-dependent lipid peroxidation. Heme oxygenase-1 is a recognized antioxidant enzyme and an important regulatory factor in ferroptosis that modulates ferroptosis through various pathways and, in turn, regulates NAFLD. This paper reviews the regulatory mechanism of heme oxygenase-1 on NAFLD in ferroptosis pathway, with a view to clarifying the occurrence and development mechanisms of NAFLD and providing new vision and targets for its prevention and treatment.

[Real-world study on the efficacy and safety of first-line antiviral therapy for chronic hepatitis B]

Objective: To clarify the clinical efficacy of first-line oral antiviral drugs tenofovir alafenamide (TAF), tenofovir disoproxil fumarate (TDF), and entecavir (ETV) in the treatment of chronic hepatitis B (CHB) and their safety profiles with lipid, bone, and kidney metabolism. Methods: 458 CHB cases diagnosed and treated at the Department of Hepatology of Integrated Traditional Chinese and Western Medicine of the Third Hospital of Hebei Medical University from February 2010 to November 2022 were selected. TAF (175 cases), TDF (124 cases), and ETV (159 cases) were used as therapies. At 24 and 48 weeks, the virology, biochemical response, changes in liver stiffness measurement (LSM), and bone, kidney, and blood lipid metabolism safety profiles were compared and analyzed. Results: After 24 and 48 weeks of TAF, TDF, and ETV therapy, HBV DNA load decreased by 3.28, 2.69, and 3.14 log10 IU/ml and 3.28, 2.83, and 3.65 log10 IU/ml, respectively, compared with the baseline, and the differences between the three groups were statistically significant, P < 0.001. The complete virological response rates were 73.95%, 66.09%, 67.19%, and 82.22%, 72.48%, and 70.49%, respectively. The incidence rates of low-level viremia were 16.67%, 21.70%, and 23.08%, while poor response rates were 1.11%, 3.67%, and 4.10%. ALT normalization rates were 64.00%, 63.89%, 67.96%, and 85.33%, 80.56%, 78.64%, respectively, and there was no statistically significant difference among the groups. LSM was significantly improved in patients treated with TAF for 48 weeks, P = 0.022. Serum phosphorus level gradually decreased with the prolongation of TDF treatment. The TAF treatment group had a good safety profile for kidney, bone, and phosphorus metabolism, with no dyslipidemia or related occurrences of risk. Conclusion: There are some differences in the therapeutic effects of first-line anti-HBV drugs. TAF has the lowest incidence of low-level viremia after 48 weeks of treatment and has a good safety profile in kidney, bone, and blood lipid metabolism.

[Applied research of ultrasound attenuation parameter in the diagnosis of metabolic dysfunction-associated fatty liver disease]

Objective: To evaluate the efficacy, establish a diagnostic model, and value of ultrasound attenuation parameters (UAP) to diagnose hepatic steatosis in metabolic dysfunction-associated fatty liver disease (MAFLD) and its relevant disorders. Methods: 3770 cases were selected from the Health Examination Center of the Third Hospital of Hebei Medical University between October to December 2020. MAFLD diagnosis was based on the Asia-Pacific region MAFLD clinical diagnosis and treatment guidelines. The degree of hepatic steatosis was divided into mild, moderate and severe according to ultrasound imaging. UAP, clinical characteristic indexes, serum biochemical indexes, characteristics of hepatic steatosis and related factors were compared and analyzed in MAFLD patients and healthy controls. Logistic regression method was used to analyze the independent risk factors affecting the progression of hepatic steatosis in MAFLD to establish the diagnostic model. The clinical efficacy of UAP and the new model in diagnosing MAFLD was evaluated by the receiver operating characteristic curve (ROC). One-way ANOVA was used to compare means among multiple groups. Mann-Whitney U test was used to compare non-normally distributed measurement data between the two groups, and rank-sum test was used to compare multiple groups. χ² test was used to compare count data between groups. Results: Among the 3 770 cases, 650 were MAFLD, with a prevalence rate of 17.24%, and the highest prevalence was 37.23% in the age group of 60-69. The prevalence rate was significantly higher in male than female (30.34% vs. 9.17%). Age-sex analysis showed that the prevalence rate in males aged 30-69 years was 38.26%, and that in females aged over 60 years was 31.94%. UAP was significantly higher in patients with MAFLD than healthy controls (278.55 dB/m vs. 220.90 dB/m, Z=-12.592, P＜0.001), and an increasing trend with increased degree of hepatic steatosis (mild:257.20 dB/m, moderate:286.20 dB/m, and severe: 315.00 dB/m) were observed. The cut-off values of UAP for the diagnosis of mild, moderate and severe hepatic steatosis were 243≤UAP＜258 dB/m, 258≤UAP＜293 dB/m, ≥293 dB/m in MAFLD. The sensitivity and specificity were 67.20%, 93.60%, 95.90%, and 82.10%, 72.00%, and 84.80%, respectively. UAP, alanine aminotransferase and fasting blood glucose were independent risk factors for the progression of hepatic steatosis in MAFLD. The combined MAFLD classification model (UAG model) was established. The AUC of mild, moderate and severe hepatic steatosis in MAFLD were 0.906, 0.907, and 0.946, respectively, and the sensitivity and specificity were 76.50%, 82.10%, 98.00%, and 90.80%, 83.30% and 76.10%, respectively. Conclusion: MAFLD is a common disease in the general population, with a higher incidence in male and elderly female over 30 years of age. UAP can be used as a new noninvasive diagnostic technique to evaluate hepatic steatosis in MAFLD. The UAG model has a good diagnostic efficacy on MAFLD and its relevant disorders, and thus can be used as a guide for evaluating clinical diagnosis and prognosis.

[Study on plasma Golgi protein 73 and related models in the diagnosis of nonalcoholic fatty liver disease]

Objective: To investigate the relationship between plasma Golgi protein 73 (GP73) levels and the occurrence and development of non-alcoholic fatty liver disease (NAFLD), and to establish a diagnostic model based on this combination with lipid metabolism indicators to clarify its diagnostic efficacy and clinical application value for NAFLD. Methods: 225 cases with NAFLD [diagnosed by ultrasound, transient elastography (FibroScan502) and liver biopsy (some patients)] and 108 healthy controls were selected from the Department of Hepatology and Physical Examination Center of Integrated Traditional Chinese and Western Medicine, The Third Hospital of Hebei Medical University. Clinical data, routine peripheral blood and serum biochemical test results were collected. The plasma GP73 level was detected by enzyme-linked immunosorbent assay. SPSS 21.0 statistical software was used for statistical analysis. Binary logistic regression model was used to calculate the NAFLD diagnostic model. Receiver operating characteristic curve was used to evaluate the NAFLD constructed model diagnostic efficacy. Results: NAFLD incidence was significantly reduced in younger age group, mostly in young and middle-aged male. However, the NAFLD incidence was increased with increasing age in female. The analysis of age ratio composition showed that the average age for NAFLD onset was 20 ~ 50 years old, and the incidence rate was as high as 47% in among 30 ~ 39 years old, but the incidence rate was significantly decreased in over 60 years old (4.00%). GP73 was an independent risk factor for the occurrence and development of NAFLD. The diagnostic models of GBT, GB and GT were established by GP73 (G) combined with body mass index (BMI, B) and serum triglyceride (TG, T), and the results showed that the areas under the curves of GBT, GB and GT models were 0.969, 0.937 and 0.909, respectively. The sensitivity and the specificity were 84.90%, 77.80% and 84.00%, and 95.40%, 95.40% and 82.40%, respectively, P < 0.05. The GBT model had efficacy of best diagnostic performance. Conclusion: NAFLD is more common in young and middle-aged male, but with advanced age, the incidence of female patients gradually increases. Plasma GP73 levels are related to the occurrence and development of NAFLD. The GBT model can be used as a new model for non-invasive diagnosis and one of the indicators for clinical evaluation of diagnostic efficacy of NAFLD.

[Clinical study of yiqi huoxue recipe in the treatment of liver fibrosis of chronic viral hepatitis]

Objective: To clarify the clinical efficacy of Yiqi Huoxue recipe in the treatment of liver fibrosis of chronic viral hepatitis. Methods: An open, positive-drug, parallel-controlled study method was applied. A total of 207 cases of liver fibrosis with chronic hepatitis B and C diagnosed with liver biopsy and transient elastography were selected. According to the principle of syndrome differentiation in traditional Chinese medicine, self-made Yiqi Huoxue recipe (n = 127) and Fuzheng Huayu capsule (n = 80) were used for the treatment course of 24-48 weeks. Change score of TCM symptom, liver biochemistry, liver stiffness measurement (LSM), and noninvasive liver fibrosis index [aspartate transaminase to platelet ratio index (APRI), and fibrosis-4 score (FIB-4)] were compared between the two groups to evaluate the therapeutic effect of Yiqi Huoxue recipe on liver fibrosis. Results: Yiqi Huoxue recipe group and Fuzheng Huayu capsule group baseline LSM, APRI and FIB-4 was compared, and there was no statistically significant difference between them (P > 0.05). Yiqi Huoxue recipe and Fuzheng Huayu capsule received patients had improved symptom scores to a certain extent. Hepatic facies, discomfort over liver area, and soreness and weakness of waist and knees (P < 0.05) was significantly improved in Yiqi Huoxue recipe than Fuzheng Huayu capsule. Liver biochemical indicators (ALT, AST, GGT, ALP) had gradually relapsed with the extension of treatment duration and the normalization rate between the two groups after 24 to 48 weeks had reached 100% vs. 100%, 100% vs. 93.8%, 96.8% vs. 92.3% and 87.5% vs. 81.8%. After 12 weeks of treatment, APRI values ​​of both groups had significantly reduced, and after 48 weeks of treatment, LSM values of both groups had significantly improved. Moreover, Yiqi Huoxue recipe FIB-4 score was significantly improved after 48 weeks of treatment, and the difference was statistically significant compared to Fuzheng Huayu capsule group (P < 0.05). After treatment, LSM, APRI, and FIB-4 total effectiveness in the two groups were 80.0% vs. 63.6%, P = 0.046; 68.4% vs. 52.0%, P = 0.052; 68.4% vs. 62.0%, P = 0.437, respectively. LSM total effectiveness was significantly higher in Yiqi Huoxue recipe treated group than Fuzheng Huayu capsule group. Conclusion: Traditional Chinese medicine Yiqi Huoxue decoction can be used as an optimal treatment for liver fibrosis of chronic viral hepatitis.

Protective Properties of FOXO1 Inhibition in a Murine Model of Non-alcoholic Fatty Liver Disease Are Associated With Attenuation of ER Stress and Necroptosis

Aim

The pathogenesis of non-alcoholic fatty liver disease is currently unclear, however, lipid accumulation leading to endoplasmic reticulum stress appears to be pivotal in the process. At present, FOXO1 is known to be involved in NAFLD progression. The relationship between necroptosis and non-alcoholic steatohepatitis has been of great research interest more recently. However, whether FOXO1 regulates ER stress and necroptosis in mice fed with a high fat diet is not clear. Therefore, in this study we analyzed the relationship between non-alcoholic steatohepatitis, ER stress, and necroptosis.

Main Methods

Male C57BL/6J mice were fed with an HFD for 14 weeks to induce non-alcoholic steatohepatitis. ER stress and activation of necroptosis in AML12 cells were evaluated after inhibition of FOXO1 in AML12 cells. In addition, mice were fed with AS1842856 for 14 weeks. Liver function and lipid accumulation were measured, and further, ER stress and necroptosis were evaluated by Western Blot and Transmission Electron Microscopy.

Key Findings

Mice fed with a high fat diet showed high levels of FOXO1, accompanying activation of endoplasmic reticulum stress and necroptosis. Further, sustained PA stimulation caused ER stress and necroptosis in AML12 cells. At the same time, protein levels of FOXO1 increased significantly. Inhibition of FOXO1 with AS1842856 alleviated ER stress and necroptosis. Additionally, treatment of mice with a FOXO1 inhibitor ameliorated liver function after they were fed with a high fat diet, displaying better liver condition and lighter necroptosis.

Significance

Inhibition of FOXO1 attenuates ER stress and necroptosis in a mouse model of non-alcoholic steatohepatitis.

Liver governs adipose remodelling via extracellular vesicles in response to lipid overload

Lipid overload results in lipid redistribution among metabolic organs such as liver, adipose, and muscle; therefore, the interplay between liver and other organs is important to maintain lipid homeostasis. Here, we show that liver responds to lipid overload first and sends hepatocyte-derived extracellular vesicles (EVs) targeting adipocytes to regulate adipogenesis and lipogenesis. Geranylgeranyl diphosphate synthase (Ggpps) expression in liver is enhanced by lipid overload and regulates EV secretion through Rab27A geranylgeranylation. Consistently, liver-specific Ggpps deficient mice have reduced fat adipose deposition. The levels of several EV-derived miRNAs in the plasma of non-alcoholic fatty liver disease (NAFLD) patients are positively correlated with body mass index (BMI), and these miRNAs enhance adipocyte lipid accumulation. Thus, we highlight an inter-organ mechanism whereby the liver senses different metabolic states and sends corresponding signals to remodel adipose tissue to adapt to metabolic changes in response to lipid overload.

[Application of heme oxygenase 1 in the diagnosis of non-alcoholic fatty liver disease]

Objective: To explore the clinical value of plasma heme oxygenase 1(HO-1) in the development of non-alcoholic fatty liver disease(NAFLD). Methods: Patients with NAFLD were selected from the Physical examination center and the Department of Traditional and Western Medical Hepatology of Third Hospital of Hebei Medical University. A combination of ultrasound and liver elastography was used to screen NAFLD patients and healthy persons. General clinical characteristics, peripheral blood cell count and liver biochemical test results were collected synchronously, plasma samples were retained, and plasma HO-1 level was detected by enzyme-linked immunosorbent assay. SPSS21.0 statistical software was used for statistical analysis, multivariate logistic regression analyses was used to analyse the independent risk factors affecting the incidence and progression of NAFLD. The diagnostic efficacy of indicators related to development of NAFLD was assessed by the receiver operating characteristic curve(ROC). Results: A total of 328 patients with NAFLD and 113 healthy controls were included. According to the liver biochemical results, the NAFLD group was divided into 148 patients with normal liver enzymes and 180 patients with abnormal liver enzymes. The level of HO-1 in the three groups was 9.09 ± 2.19, 14.38 ± 2.63, 17.00 ± 3.30 ng/ml, and was increased respectively of healthy controls, patients with normal liver enzymes and patients with abnormal liver enzymes. Analyzing plasma HO-1 levels of components associated with metabolic disorders suggests that components without metabolic syndrome(9.83 ± 3.21) < components with 1 metabolic syndrome(13.59 ± 3.72) < components with 2 or more metabolic syndrome(16.09 ± 3.41), P < 0.001. The results of HO-1 level stratification analysis showed that WBC, ALT, AST, GGT, TG increased as HO-1 level increased, and the pairwise difference was statistically significant (P < 0.001). The WBC count of NAFLD is significantly higher than healthy group(6.79 ± 1.62 vs 5.68 ± 1.36, P < 0.001). The univariate and multivariate regression analyses of all the subjects showed that HO-1, TG and BMI were prognostic factors for the occurrence of NAFLD and HO-1, TC, GLU were prognostic factors for the progression of NAFLD, P < 0.05. The ROC analysis showed that HO-1 was reliable markers for predicting the occurrence and progression of NALFD, the sensitivity and specificity were respectively 85.10%, 92.90% and 38.33%, 95.27%. Conclusion: Plasma HO-1 can predict the occurrence and progression of NAFLD and is expected to be a novel molecular diagnostic marker for NAFLD and NASH.

[An interpretation of the AASLD practice guideline on the diagnosis and management of nonalcoholic fatty liver disease in 2017]

The American Association for the Study of Liver Diseases (AASLD) updated and published the Practice Guidance for the Diagnosis and Management of Nonalcoholic Fatty Liver Disease (NAFLD) in July 2017, which provides recommendations for the accurate diagnosis, treatment, and effective prevention of NAFLD. Related metabolic diseases should be considered during the initial evaluation of patients suspected of NAFLD. Noninvasive diagnostic techniques including transient elastography, magnetic resonance elastography, and serum biochemical models should be used to evaluate the development and progression of liver fibrosis in patients with NAFLD. Clinical liver pathology report should clearly differentiate between nonalcoholic fatty liver (NAFL), NAFL with inflammation, and nonalcoholic steatohepatitis (NASH) and identify the presence or absence of liver fibrosis and its degree. Early medication for NAFLD can only be used in patients with pathologically confirmed NASH and liver fibrosis, and it is not recommended to use pioglitazone and vitamin E as the first-line drugs for patients with NASH which has not been proven by biopsy or non-diabetic NASH patients. Foregut bariatric surgery can be considered for obese patients with NAFLD/NASH who meet related indications. It is emphasized that the risk factors for cardiovascular disease should be eliminated for NAFLD patients. Statins can be used for the treatment of dyslipidemia in patients with NAFLD/NASH, but they cannot be used in patients with decompensated liver cirrhosis. Routine screening or hepatocellular carcinoma surveillance is not recommended for NASH patients without liver cirrhosis. Cardiovascular disease should be taken seriously during liver transplantation evaluation. There is still no adequate clinical evidence for the treatment of NAFLD in children and adolescents, and intensive lifestyle intervention is recommended as the first-line therapy for such patients.

Current but not past hepatitis B virus infection is associated with a decreased risk of nonalcoholic fatty liver disease in the Chinese population: A case-control study with propensity score analysis

The relation between hepatitis B virus (HBV) infection and fatty liver has been addressed by several observational studies, but their results remain controversial. To date, no study has precisely investigated the association of current and past HBV infection with the risk of nonalcoholic fatty liver disease (NAFLD) in the Chinese population. Therefore, we conducted a hospital-based case-control study in southwestern China to clarify this issue. A total of 631 newly ultrasound-diagnosed NAFLD cases and 2357 controls were selected from 123 243 consecutive patients admitted to a tertiary-care hospital between January 2015 and December 2016. Multivariate logistic regression was employed to calculate adjusted odds ratios (ORs) and 95% confidence intervals (CIs). A propensity score was developed for adjustment and matching. Subgroup analysis was conducted to identify potential effect modifiers. Current and past HBV infection had an overall prevalence of 9.7% and 55.2%, respectively. In the fully adjusted model, current HBV infection was associated with a decreased risk of NAFLD (OR 0.64; 95% CI 0.42-0.95). A similar inverse association was observed in both propensity-score-adjusted (OR 0.58; 95% CI 0.40-0.86) and propensity-score-matched analyses (OR 0.61; 95% CI 0.40-0.92).The inverse association was stronger in patients with hypertension than in those without (P_interaction  = .018).No significant association between past HBV infection and NAFLD risk was found. In conclusion, current but not past HBV infection is associated with a decreased risk of NAFLD in the Chinese population. The corresponding biological mechanisms remain to be elucidated.

MicroRNA-122 Inhibits Lipid Droplet Formation and Hepatic Triglyceride Accumulation via Yin Yang 1

BACKGROUND/AIMS

An increase in intracellular lipid droplet formation and hepatic triglyceride (TG) content usually results in nonalcoholic fatty liver disease. However, the mechanisms underlying the regulation of hepatic TG homeostasis remain unclear.

METHODS

Oil red O staining and TG measurement were performed to determine the lipid content. miRNA expression was evaluated by quantitative PCR. A luciferase assay was performed to validate the regulation of Yin Yang 1 (YY1) by microRNA (miR)-122. The effects of miR-122 expression on YY1 and its mechanisms involving the farnesoid X receptor and small heterodimer partner (FXR-SHP) pathway were evaluated by quantitative PCR and Western blot analyses.

RESULTS

miR-122 was downregulated in free fatty acid (FFA)-induced steatotic hepatocytes, and streptozotocin and high-fat diet (STZ-HFD) induced nonalcoholic steatohepatitis (NASH) in mice. Transfection of hepatocytes with miR-122 mimics before FFA induction inhibited lipid droplet formation and TG accumulation in vitro. These results were verified by overexpressing miR-122 in the livers of STZ-HFD-induced NASH mice. The 3'-untranslated region (3'UTR) of YY1 mRNA is predicted to contain an evolutionarily conserved miR-122 binding site. In silico searches, a luciferase reporter assay and quantitative PCR analysis confirmed that miR-122 directly bound to the YY1 3'UTR to negatively regulate YY1 mRNA in HepG2 and Huh7 cells. The (FXR-SHP) signaling axis, which is downstream of YY1, may play a key role in the mechanism of miR-122-regulated lipid homeostasis. YY1-FXR-SHP signaling, which is negatively regulated by FFA, was enhanced by miR-122 overexpression. This finding was also confirmed by overexpression of miR-122 in the livers of NASH mice.

CONCLUSIONS

The present results indicate that miR-122 plays an important role in lipid (particularly TG) accumulation in the liver by reducing YY1 mRNA stability to upregulate FXR-SHP signaling.

Interleukin-10 Contributes to Therapeutic Effect of Mesenchymal Stem Cells for Acute Liver Failure via Signal Transducer and Activator of Transcription 3 Signaling Pathway

Background:

Mesenchymal stem cells (MSCs) transplantation has been proven to have therapeutic potential for acute liver failure (ALF). However, the mechanism remains controversial. Recently, modulation of inflammation by MSCs has been regarded as a crucial mechanism. The aim of the present study was to explore the soluble cytokines secreted by MSCs and their therapeutic effects in ALF.

Methods:

MSCs isolated from Sprague-Dawley rats were identified by fluorescence-activated cell sorting analysis. Conditioned medium derived from MSCs (MSCs-CM) was collected and analyzed by a cytokine microarray. MSCs and MSCs-CM were transplanted into rats with D-galactosamine-induced ALF. Liver function, survival rate, histology, and inflammatory factors were determined. Exogenous recombinant rat interleukin (IL)-10, anti-rat IL-10 antibody, and AG490 (signal transducer and activator of transcription 3 [STAT3] signaling pathway inhibitor) were administered to explore the therapeutic mechanism of MSCs-CM. Statistical analysis was performed with SPSS version 19.0, and all data were analyzed by the independent-sample t-test.

Results:

There are statistical differences of the survival curve between ALF+MSCs group and ALF+Dulbecco's modified Eagle's medium (DMEM) group, as well as ALF+MSCs-CM group and ALF+DMEM group (all P < 0.05). Serum alanine aminotransferase (ALT) level in the ALF+MSCs and ALF+MSCs-CM groups was lower than that in the ALF+DMEM group (865.53±52.80 vs. 1709.75±372.12 U/L and 964.72±414.59 vs. 1709.75±372.12 U/L, respectively, all P < 0.05); meanwhile, serum aspartate aminotransferase (AST) level in the ALF+MSCs and ALF+MSCs-CM groups was lower than that in the ALF+DMEM group (2440.83±511.94 vs. 4234.35±807.30 U/L and 2739.83±587.33 vs. 4234.35±807.30 U/L, respectively, all P < 0.05). Furthermore, MSCs or MSCs-CM treatment significantly reduced serum interferon-γ (IFN-γ), IL-1β, IL-6 levels and increased serum IL-10 level compared with DMEM (all P < 0.05). Proteome profile analysis of MSCs-CM indicated the presence of anti-inflammatory factors and IL-10 was the most distinct. Blocking of IL-10 confirmed the therapeutic significance of this cytokine. Phosphorylated STAT3 was upregulated after IL-10 infusion and inhibition of STAT3 by AG490 reversed the therapeutic effect of IL-10.

Conclusions:

The factors released by MSCs, especially IL-10, have the potential for therapeutic recovery of ALF, and the STAT3 signaling pathway may mediate the anti-inflammatory effect of IL-10.

[Role of neutrophils in treatment of rats with D-galactosamine-induced acute liver failure with bone marrow mesenchymal stem cells]

Objective: To investigate the therapeutic effect of bone marrow mesenchymal stromal cell (BMSC) transplantation on D-galactosamine-induced acute liver failure in Sprague-Dawley (SD) rats, as well as the mechanism of neutrophils in this process. Methods: A total of 39 male SD rats were divided into control group (8 rats, intraperitoneal injection of isotonic saline), model group (10 rats, intraperitoneal injection of D-galactosamine), solvent group (9 rats, tail vein injection of isotonic saline at 2 hours after intraperitoneal injection of D-galactosamine), and treatment group (12 rats, tail vein injection of MSCs at 2 hours after intraperitoneal injection of D-galactosamine). The rats were sacrificed at 24 hours after the model of D-galactosamine-induced acute liver failure was established, and the blood and liver tissue were harvested. The serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and total bilirubin (TBil) were measured, and blood analysis was performed to measure the number and percentage of neutrophils in peripheral blood. Immunofluorescence assay was used to measure the expression of the neutrophil marker Ly6g in the liver, the myeloperoxidase (MPO) kit was used to measure the activity of MPO in liver, and RT-PCR was used to measure the mRNA expression of inflammatory cytokines and chemokines in the liver, i.e., tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), interferon-γ(IFN-γ), interleukin-10 (IL-10), CXC chemokine ligand 1 (CXCL1), and CXC chemokine ligand 2 (CXCL2). Another 64 male SD rats were randomly divided into groups, and the survival rates of rats in each group were observed for 7 days. The independent samples t-test was used for comparison between any two groups (Levene homogeneity test of variance, and the corrected t-test was used for a P value of < 0.05), and the log-rank test was used for comparison of survival rates between any two groups. Results: At 24 hours after acute liver failure was induced by D-galactosamine in the SD rats, there were significant increases in the liver function parameters (ALT: 2884.1±541.0 U/L vs 45.4±11.0 U/L,P< 0.001; AST: 3634.9±755.9 U/L vs 143.9±23.7 U/L,P< 0.001; TBil: 44.4±8.4μmmol/L vs 0.9±0.2μmmol/L,P< 0.001) and the number and percentage of peripheral blood neutrophils [number: (4.7±1.1)×109 vs (1.4±0.4)×109,P< 0.001; percentage: 44.9%±8.0% vs 18.3%±4.4%,P< 0.001]. A large number of neutrophils aggregated in the liver tissue, and there were significant increases in the MPO activity (4.72±1.09 U/g vs 1.13±0.24 U/g,P< 0.001), inflammatory cytokines, and chemokines. Compared with the model group, the treatment group showed significant improvements in liver function (ALT: 1 823.9±389.2 U/L vs 2 884.1±541.0 U/L,P< 0.001; AST: 2173.0±567.3 U/L vs 3634.9±755.9 U/L,P< 0.001; TBil: 30.9±6.5μmmol/L vs 44.4±8.4μmmol/L,P< 0.001) and survival rate (50% vs 12.5%,P= 0.023). Meanwhile, the treatment group also showed significant reductions in the number and percentage of peripheral blood neutrophils [number: (3.5±1.0)×109 vs (4.7±1.1)×109,P= 0.012; percentage: 35.9%±8.9% vs 44.9%±8.0%,P= 0.021], number of neutrophils in the liver, and MPO activity (3.52±1.03 U/g vs 4.72±1.09 U/g,P= 0.040), as well as significantly inhibited expression of inflammatory cytokines and chemokines (TNF-α: 2.458±0.762 vs 3.778±1.046, P = 0.005; IL-1β: 2.498±0.547 vs 4.065 ± 0.953,P= 0.002; IFN-γ: 3.977±1.039 vs 5.418±1.255, P = 0.025; IL-10: 6.056±1.542 vs 3.368±0.952,P= 0.001; CXCL1: 7.988±1.911 vs 10.366±1.239,P= 0.010; CXCL2: 3.441±1.005 vs 4.847±1.113,P= 0.019). Conclusion: BMSC transplantation has a therapeutic effect on D-galactosamine-induced acute liver failure in rats, and this process is accompanied by reduced aggregation and activity of neutrophils in peripheral blood and liver. Inflammatory cytokines and chemokines may be involved in the mechanism of regulation of these two aspects.

No transmission of porcine endogenous retrovirus in an acute liver failure model treated by a novel hybrid bioartificial liver containing porcine hepatocytes

BACKGROUND

A novel hybrid bioartificial liver (HBAL) was constructed using an anionic resin adsorption column and a multi-layer flat-plate bioreactor containing porcine hepatocytes co-cultured with bone marrow mesenchymal stem cells (MSCs). This study aimed to evaluate the microbiological safety of the HBAL by detecting the transmission of porcine endogenous retroviruses (PERVs) into canines with acute liver failure (ALF) undergoing HBAL.

METHODS

Eight dogs with ALF received a 6-hour HBAL treatment on the first day after the modeling by D-galactosamine administration. The plasma in the HBAL and the whole blood in the dogs were collected for PERV detection at regular intervals until one year later when the dogs were sacrificed to retrieve the tissues of several organs for immunohistochemistry and Western blotting for the investigation of PERV capsid protein gag p30 in the tissue. Furthermore, HEK293 cells were incubated to determine the in vitro infectivity.

RESULTS

PERV RNA and reverse transcriptase activity were observed in the plasma of circuit 3, suggesting that PERV particles released in circuit 3. No positive PERV RNA and reverse transcriptase activity were detected in other plasma. No HEK293 cells were infected by the plasma in vitro. In addition, all PERV-related analyses in peripheral blood mononuclear cells and tissues were negative.

CONCLUSION

No transmission of PERVs into ALF canines suggested a reliable microbiological safety of HBAL based on porcine hepatocytes.

Development of human bone marrow derived cells lines stably expressing Tet regulated hepatocyte growth factor or fibroblast growth factor 4 gene

AIM: To develop human bone marrow derived cells lines stably expressing Tet regulated hepatocyte growth factor (HGF) or fibroblast growth factor 4 (FGF4) gene.

METHODS: HGF and FGF4 genes were synthesized and then cloned into a lentiviral vector to result in plenti6.3/TO-HGF and plenti6.3/TO-FGF4, respectively. Lenti3.3/TR was transfected into UE7T-13 cells to develop a UE7T-13-TR cell line possessing Tet-on gene swift. Then, plenti6.3/TO-HGF and plenti6.3/TO-FGF4 were used to transfect UE7T-13-TR cell to result in UE7T-13-TR-HGF cell line that could stably express Tet regulated HGF and UE7T-13-TR-FGF4 cell line that could stably express Tet regulated FGF4. The expression of target genes was detected by Q-PCR, and the levels and secretion of proteins were detected by Western blot and ELISA.

RESULTS: We successfully developed UE7T-13-TR-HGF and UE7T-13-TR-FGF4 cell lines. Q-PCR analysis verified that the expression of the HGF gene in UE7T-13-TR-HGF in the presence of Tet was 78-fold higher than that in the absence of Tet, and the fold change for FGF4 was more than 20 thousand folds. Western blot and ELISA analyses verified that HGF and FGF4 proteins could be synthesized and secreted outside the cell membrane.

CONCLUSION: We have successfully developed UE7T-13-TR-HGF and UE7T-13-TR-FGF4 cell lines through lentiviral transfection, which lays a foundation for further study.

Targeted migration of mesenchymal stem cells modified with CXCR4 to acute failing liver improves liver regeneration

AIM: To improve the colonization rate of transplanted mesenchymal stem cells (MSCs) in the liver and effect of MSC transplantation for acute liver failure (ALF).

METHODS: MSC was modified with the chemokine CXC receptor 4 (CXCR4) gene (CXCR4-MSC) or not (Null-MSC) through lentiviral transduction. The characteristics of CXCR4-MSCs and Null-MSCs were determined by real-time quantitative polymerase chain reaction, Western blotting and flow cytometry. CXCR4-MSCs and Null-MSCs were infused intravenously 24 h after administration of CCl₄ in nude mice. The distribution of the MSCs, survival rates, liver function, hepatocyte regeneration and growth factors of the recipient mice were analyzed.

RESULTS: In vitro, CXCR4-MSCs showed better migration capability toward stromal cell-derived factor-1α and a protective effect against thioacetamide in hepatocytes. In vivo imaging showed that CXCR4-MSCs migrated to the liver in larger numbers than Null-MSCs 1 and 5 d after ALF. Higher colonization led to a longer lifetime and better liver function. Either CXCR4-MSCs or Null-MSCs exhibited a paracrine effect through secreting hepatocyte growth factor and vascular endothelial growth factor. Immunohistochemical analysis of Ki-67 showed increased cell proliferation in the damaged liver of CXCR4-MSC-treated animals.

CONCLUSION: Genetically modified MSCs expressing CXCR4 showed greater colonization and conferred better functional recovery in damaged liver.

Spontaneous emission modulation of colloidal quantum dots via efficient coupling with hybrid plasmonic photonic crystal

The spontaneous emission of colloidal CdSe/ZnS quantum dots (CQDs) modified by the hybrid plasmonic-photonic crystal is reported in this paper. By using a spin coater, the spatial overlap between CQDs and the surface resonance modes in this quasi-2D crystal slab is achieved. In this case, the coupling efficiency of them is enhanced greatly and most excited CQDs radiate through the surface modes. Consequently, despite the low refractive index contrast of our hybrid structure, the directionality of spontaneous emission, increased radiative probability and narrowed full width at half maximum of emission peak are all clearly observed by our home-made microscopic angle-resolved spectroscopy and time-resolved photoluminescence system. Our results manifest that the quasi-2D hybrid plasmonic-photonic crystal is an ideal candidate to tailor the radiative properties of CdSe/ZnS CQDs, which might be significant for the applications of light emitting devices.

Genetically modified mesenchymal stem cells overexpressing CXCR4 show increased colonization ability and confer better liver regeneration in mice

AIM: To explore whether mesenchymal stem cells (MSCs) overexpressing CXCR4 show increased colonization ability and confer better liver regeneration in mice.

METHODS: MSCs were modified with CXCR4 gene (CXCR4-MSCs) or not (Null-MSCs) through lentiviral transduction. The characteristics of CXCR4-MSCs and Null-MSCs were determined by RT-PCR and flow cytometry. CXCR4-MSCs and Null-MSCs were infused intravenously 24 h after administration of CCl4 in nude mice. The concentration of SDF-1α in the damaged liver was detected by ELISA. Transwell migration assays were carried out to evaluate the migration ability of MSCs toward SDF-1α. The distribution of the stem cells, their survival rates, liver function, histopathology and hepatocyte regeneration were analyzed.

RESULTS: Transfected MSCs overexpressed CXCR4 at both gene and protein levels. In vitro, CXCR4-MSCs showed better migration capability toward SDF-1α. In vivo imaging showed that CXCR4-MSCs migrated to the liver in greater numbers than Null-MSCs 5 d after intravenous infusion in mice with acute liver failure (ALF). Higher colonization led to a longer lifetime and better liver function. Immunohistochemistry analysis of Ki-67 showed increased cell proliferation in the damaged liver of CXCR4-MSC-treated animals.

CONCLUSION: Genetically modified MSCs expressing CXCR4 show greater colonization ability and confer better functional recovery of the damaged liver.

Intravenous administration of endothelial progenitor cells transfected with the TRAIL gene inhibits the growth of tumors derived from H22 cells in nude mice

AIM: To investigate the influence of intravenous administration of endothelial progenitor cells (EPCs) transfected with the TRAIL gene on the growth of tumors derived from subcutaneously inoculated H22 cells in nude mice to provide a theoretical basis for the treatment of liver cancer.

METHODS: The TRAIL gene was amplified by PCR, cloned into the pcDNA3.1 vector, and transfected into EPCs. The expression of TRAIL protein was detected by Western blot. Mice were inoculated subcutaneously with H22 cells to induce tumor formation. Tumor-bearing mice were randomly divided into three groups and injected via the tail vein with EPCs transfected with the recombinant adenoviral vector carrying the TRAIL gene, the empty vector, and normal saline, respectively.

RESULTS: Restriction enzyme digestion and DNA sequencing analyses indicate that the recombinant plasmid was constructed successfully. TRAIL expression was detected in EPCs transfected with the recombinant adenoviral vector by Western blot. The rate of reduced tumor growth was 47.77% in mice administered with EPCs carrying the TRAIL gene. Tumor volume and weight in the experimental group (0.791 cm3 ± 0.119 cm3, 0.29 g ± 0.04 g) were significantly lower than those in the two control groups (all P < 0.05).

CONCLUSION: The recombinant plasmid carrying the TRAIL gene has been successfully constructed. Intravenous administration of endothelial progenitor cells transfected with the TRAIL gene inhibits the growth of tumors derived from H22 cells in nude mice.

Endothelial precursor cells promote angiogenesis in hepatocellular carcinoma

AIM: To investigate the role of bone marrow-derived endothelial progenitor cells (EPCs) in the angiogenesis of hepatocellular carcinoma (HCC).

METHODS: The bone marrow of HCC mice was reconstructed by transplanting green fluorescent protein (GFP) + bone marrow cells. The concentration of circulating EPCs was determined by colony-forming assays and fluorescence-activated cell sorting. Serum and tissue levels of vascular endothelial growth factor (VEGF) and colony-stimulating factor (CSF) were quantified by enzyme-linked immunosorbent assay. The distribution of EPCs in tumor and tumor-free tissues was detected by immunohistochemistry and real-time polymerase chain reaction. The incorporation of EPCs into hepatic vessels was examined by immunofluorescence and immunohistochemistry. The proportion of EPCs in vessels was then calculated.

RESULTS: The HCC model was successful established. The flow cytometry analysis showed the mean percentage of CD133CD34 and CD133VEGFR2 double positive cells in HCC mice was 0.45% ± 0.16% and 0.20% ± 0.09% respectively. These values are much higher than in the sham-operation group (0.11% ± 0.13%, 0.05% ± 0.11%, n = 9) at 14 d after modeling. At 21 d, the mean percentage of circulating CD133CD34 and CD133VEGFR2 cells is 0.23% ± 0.19%, 0.25% ± 0.15% in HCC model vs 0.05% ± 0.04%, 0.12% ± 0.11% in control. Compared to the transient increase observed in controls, the higher level of circulating EPCs were induced by HCC. In addition, the level of serum VEGF and CSF increased gradually in HCC, reaching its peak 14 d after modeling, then slowly decreased. Consecutive sections stained for the CD133 and CD34 antigens showed that the CD133+ and CD34+ VEGFR2 cells were mostly recruited to HCC tissue and concentrated in tumor microvessels. Under fluorescence microscopy, the bone-marrow (BM)-derived cells labeled with GFP were concentrated in the same area. The relative levels of CD133 and CD34 gene expression were elevated in tumors, around 5.0 and 3.8 times that of the tumor free area. In frozen liver sections from HCC mice, cells co-expressing CD133 and VEGFR2 were identified by immunohistochemical staining using anti-CD133 and VEGFR2 antibodies. In tumor tissue, the double-positive cells were incorporated into vessel walls. In immunofluorescent staining. These CD31 and GFP double positive cells are direct evidence that tumor vascular endothelial cells (VECs) come partly from BM-derived EPCs. The proportion of GFP CD31 double positive VECs (out of all VECs) on day 21 was around 35.3% ± 21.2%. This is much higher than the value recorded on day 7 group (17.1% ± 8.9%). The expression of intercellular adhesion molecule 1, vascular adhesion molecule 1, and VEGF was higher in tumor areas than in tumor-free tissues.

CONCLUSION: Mobilized EPCs were found to participate in tumor vasculogenesis of HCC. Inhibiting EPC mobilization or recruitment to tumor tissue may be an efficient strategy for treating HCC.

Evaluation of a novel hybrid bioartificial liver based on a multi-layer flat-plate bioreactor

AIM: To evaluate the efficacy and safety of a hybrid bioartificial liver (HBAL) system in the treatment of acute liver failure.

METHODS: Canine models with acute liver failure were introduced with intravenous administration of D-galactosamine. The animals were divided into: the HBAL treatment group (n = 8), in which the canines received a 3-h treatment of HBAL; the bioartificial liver (BAL) treatment group (n = 8), in which the canines received a 3-h treatment of BAL; the non-bioartificial liver (NBAL) treatment group (n = 8), in which the canines received a 3-h treatment of NBAL; the control group (n = 8), in which the canines received no additional treatment. Biochemical parameters and survival time were determined. Levels of xenoantibodies, RNA of porcine endogenous retrovirus (PERV) and reverse transcriptase (RT) activity in the plasma were detected.

RESULTS: Biochemical parameters were significantly decreased in all treatment groups. The TBIL level in the HBAL group was lower than that in other groups (2.19 ± 0.55 μmol/L vs 24.2 ± 6.45 μmol/L, 12.47 ± 3.62 μmol/L, 3.77 ± 1.83 μmol/L, P < 0.05). The prothrombin time (PT) in the BAL and HBAL groups was significantly shorter than the NBAL and control groups (18.47 ± 4.41 s, 15.5 ± 1.56 s vs 28.67 ± 5.71 s, 21.71 ± 3.4 s, P < 0.05), and the PT in the HBAL group was shortest of all the groups. The albumin in the BAL and HBAL groups significantly increased and a significantly higher level was observed in the HBAL group compared with the BAL group (27.7 ± 1.7 g/L vs 25.24 ± 1.93 g/L). In the HBAL group, the ammonia levels significantly decreased from 54.37 ± 6.86 to 37.75 ± 6.09 after treatment (P < 0.05); there were significant difference in ammonia levels between other the groups (P < 0.05). The levels of antibodies were similar before and after treatment. The PERV RNA and the RT activity in the canine plasma were all negative.

CONCLUSION: The HBAL showed great efficiency and safety in the treatment of acute liver failure.

Protective effects of ACLF sera on metabolic functions and proliferation of hepatocytes co-cultured with bone marrow MSCs in vitro

AIM: To investigate whether the function of hepatocytes co-cultured with bone marrow mesenchymal stem cells (MSCs) could be maintained in serum from acute-on-chronic liver failure (ACLF) patients.

METHODS: Hepatocyte supportive functions and cytotoxicity of sera from 18 patients with viral hepatitis B-induced ACLF and 18 healthy volunteers were evaluated for porcine hepatocytes co-cultured with MSCs and hepatocyte mono-layered culture, respectively. Chemokine profile was also examined for the normal serum and liver failure serum.

RESULTS: Hepatocyte growth factor (HGF) and Tumor necrosis factor; tumor necrosis factor (TNF)-α were remarkably elevated in response to ACLF while epidermal growth factor (EGF) and VEGF levels were significantly decreased. Liver failure serum samples induced a higher detachment rate, lower viability and decreased liver support functions in the homo-hepatocyte culture. Hepatocytes co-cultured with MSCs could tolerate the cytotoxicity of the serum from ACLF patients and had similar liver support functions compared with the hepatocytes cultured with healthy human serum in vitro. In addition, co-cultured hepatocytes maintained a proliferative capability despite of the insult from liver failure serum.

CONCLUSION: ACLF serum does not impair the cell morphology, viability, proliferation and overall metabolic capacities of hepatocyte co-cultured with MSCs in vitro.

Taxonomic identification of a novel strain of Streptomyces cavourensis subsp. washingtonensis, ACMA006, exhibiting antitumor and antibacteria activity

Taxonomically diverse and genetically specialized, marine microorganisms have great potential in generating bioactive substances. A previous study isolated a novel actinomycete strain designated ACMA006 and revealed that the fermentation broth of ACMA006 (FBA6) significantly inhibited the growth of a series of tumor cell lines. The present study examined various characteristics of the ACMA006 strain, including its morphological, physiological, and biochemical nature, and the 16S rDNA gene sequence of ACMA006 and biological activity of FBA6. The ACMA006 strain grew at an optimal temperature of 28°C on nearly all media tested, except for Czapek's agar, producing an exuberant substrate and aerial hyphae. Phylogenetic analysis showed that the 16S rDNA gene sequence of ACMA006 was closely related to that of Streptomyces cavourensis subsp. washingtonensis, with a sequence similarity of nearly 100%. However, ACMA006 differed somewhat from Streptomyces cavourensis subsp. washingtonensis in terms of its morphological, physiological, and biochemical characteristics. According to a bioactivity assay, FBA6 strongly inhibited the growth of hepatocellular carcinoma cell line HepG2, while it was weakly cytotoxic to human normal hepatocytes LO2 according to an MTT assay. In addition, the growth of bacterial strains Bacillus subtilis and Staphylococcus aureus but not Escherichia coli, B. aerogenes, Pseudomonas fluorescence, and B. proteus was significantly suppressed by FBA6 as indicated by the filter paper disc method. Results of this study indicated that the strain ACMA006 represents a new strain of the Streptomyces cavourensis subsp. washingtonensis and that the active metabolites of this strain are candidates for utilization as anticancer or antibacterial agents.

Do common in silico tools predict the clinical consequences of amino-acid substitutions in the CFTR gene?

Computational methods are used to predict the molecular consequences of amino-acid substitutions on the basis of evolutionary conservation or protein structure, but their utility in clinical diagnosis or prediction of disease outcome has not been well validated. We evaluated three popular computer programs, namely, PANTHER, SIFT and PolyPhen, by comparing the predicted clinical outcomes for a group of known CFTR missense mutations against the diagnosis of cystic fibrosis (CF) and clinical manifestations in cohorts of subjects with CF-disease and CFTR-related disorders carrying these mutations. Owing to poor specificity, none of tools reliably distinguished between individual mutations that confer CF disease from mutations found in subjects with a CFTR-related disorder or no disease. Prediction scores for CFTR mutations derived from PANTHER showed a significant overall statistical correlation with the spectrum of disease severity associated with mutations in the CFTR gene. In contrast, PolyPhen- and SIFT-derived scores only showed significant differences between CF-causing and non-CF variants. Current computational methods are not recommended for establishing or excluding a CF diagnosis, notably as a newborn screening strategy or in patients with equivocal test results.

Establishment and application of SPA-co-operated ELISA for detection of anti-HCV-IgM

A staphylococcus aureus protein A co-operated ELISA (SPA-ELISA) for the detection of anti-HCV-IgM has been established using HCV antigenic polypeptide, SPA-bearing germs and horseradish peroxidase labelled anti-human IgM. The specificity of SPA-ELISA has been confirmed by some substitution tests, blocking tests and destroying test with 2-mercaptoethanol. The results showed that the rate of anti-HCV-IgG in a group of patients with acute hepatitis and there were significant difference in anti-HCV-IgM was higher than that of anti-HCV-IgM detected rates between patients with acute hepatitis and those with chronic hepatitis (32.26%, P < 0.01). On the other hand, the positive rates of anti-HCV-IgM were 53.66% and 63.41% in transfusion associated hepatitis, 38.10% and 42.86% in sporadic hepatitis, 6.11% and 16.33% in people who have had active social activities, 40.00% and 10.00% in a group of blood donors respectively. Furthermore, taking into account the characteristics of HCV polypeptide used, its easiness of manipulation, and elimination of the interference of anti-HCV-IgG in sera, the new SPA-ELISA is believed to be of practical value in clinical and epidemiological studies of hepatitis C.

Synthesis of the segment (11-23) located in the first tandem repeat of plasma kallikrein: comparative binding studies of this and another segment (328-343) to high-molecular-mass kininogen

The synthesis of porcine plasma kallikrein (pPK) segment (11-23), of sequence Phe-Phe-Arg-Gly-Gly-Asp-Val-Ser-Ala-Met-Tyr-Thr-Pro, present in the first tandem repeat sequence of the regulatory chain of PK, has been accomplished following the peptide fragments (5 + 4 + 4) condensation strategy in solution, as well as by fluorenylmethoxycarbonyl solid-phase chemistry. This and another synthetic PK segment of residues (328-343) present in the fourth tandem repeat sequence [Cys(ACM)-Ser-Leu-Arg-Leu-Ser-Thr-Asp-Gly-Ser-Pro-Thr-Arg-Ile-Thr-Tyr] and synthesized by a solid-phase method, were fully characterized by 1H nuclear magnetic resonance, fast atom bombardment mass spectrometry, amino acid composition and reversed-phase high-performance liquid chromatography. Proteolysis of these peptides by either rat PK (rPK) or trypsin resulted in cleavages between Arg decreases Gly for pPK (11-23) and between Arg decreases Leu and Arg decreases Ile for rPK (328-343). Kinetic studies revealed that for peptide pPK (11-23), the catalytic efficiency (kcat/Km) of rPK is congruent to 9-fold higher than that of trypsin, but for the other peptide, rPK (328-343), kcat/Km of trypsin is congruent to 49-fold higher than that of rPK. The facile cleavage of pPK (11-23) by rPK confirms the Arg13 decreases Gly14 position as the site of autolytic degradation of PK and also explains its special preference for Phe-Phe-Arg sequence.

Affinity purification of proteinases by a combination of immobilized peptidyl aldehyde and semicarbazone

D-Phe-Phe-argininal semicarbazone and Tyr-Gly-Gly-Phe-Leu-Arg-argininal semicarbazone were prepared using the solution phase synthesis method and characterized by mass spectrometry and nuclear magnetic resonance spectroscopy. The tripeptide and heptapeptide semicarbazones were individually immobilized on affi-Gel 15 resulting in two affinity columns called S3 and S7, respectively. A third affinity column was obtained by hydrolysing the semicarbazone moiety in column S3 to aldehyde (column A3). Serine proteinases such as trypsin or rat plasma kallikrein almost quantitatively bind to either S3 or A3 affinity columns. Under optimized conditions, more than 97% of trypsin bound to both columns S3 and A3. At a lower ionic strength and higher pH, 80-85% of rat plasma kallikrein bound to the same columns. Elution of both enzymes was achieved using mild conditions at near neutral pH and in the presence of a small amount of denaturant. Both proteinases were identified and characterized by high-performance liquid chromatography, sodium dodecylsulphate polyacrylamide gel electrophoresis and by their substrate specificity and inhibition profiles. A single purification (six-to seven-fold) step using either column S3 or A3 allowed the preparation of pure trypsin from commercial sources. Starting from rat plasma partially purified by a phenyl boronate column, fractionation on the S3 column allowed approximately an 87-fold purification of rat plasma kallikrein. However, serial purification of rat plasma kallikrein on column S7 followed by column A3 resulted in a purification factor of about 455.