加入变性酒精配制GOD在临床应用的实验观察

本文介绍用变性酒精,做防腐剂配制的葡萄糖氧化酶催化剂,以氧电极检测体液中葡萄糖含量的一种方法。同时介绍配制的酶试剂在室温(25℃—28℃)存放一周其活性仍为100％。本文报告的葡萄糖氧化酶,其催化活性的pH为5.1、被测的体液葡萄糖浓度在50—400mg/dl时,其CV为2.42—1.16％。加入葡萄糖量在50—120mg/dl范围内的回收率为97.5—101％;与G—HK法相比相关系数r=0.998;P>0.05、达到美国同类试剂水平,具有明显的经济效益。

酒精与人

酒精除了饮用和作燃料外,还有许多重要的用途。它是香料、油漆和擦亮剂的重要溶剂。工业酒精又名变性酒精,大多数是在乙醇里加入甲醇,十分有毒。近年来。

如何在自然科学教学中导入新课

在新教材改革中,自然科学成为一门包括物理、化学、生物等课程一体化的综合性学科,其在教学中逻辑性较强。在进入新课时,如有一个好的开场白,亦即做好新旧课的启承转合,往往会起到画龙点睛的作用。它不仅可以立即抓住学生的注意力,引起学生的求知欲望,还可以增强师生间的教学互动,完美地总结上节课,快速地引出新课,以收事半功倍之效。下面结合自己的教学实际,就如何导入新课谈点粗浅体会。

Soluble forms of extracellular cytokeratin 18 may differentiate simple steatosis from nonalcoholic steatohepatitis

AIM: To investigate whether serum levels of two soluble forms of extracellular cytokeratin 18 (M30-antigen and M65-antigen) may differentiate nonalcoholic steatohepatitis (NASH) from simple steatosis in patients with nonalcoholic fatty liver disease (NAFLD). METHODS: A total of 83 patients with suspected NAFLD and 49 healthy volunteers were investigated. Patients with suspected NAFLD were classified according to their liver histology into four groups: definitive NASH (n = 45), borderline NASH (n = 24), simple fatty liver (n = 9), and normal tissue (n = 5). Serum levels of caspase-3 generated cytokeratin-18 fragments (M30-antigen) and total cytokeratin-18 (M65-antigen) were determined by ELISA. RESULTS: Levels of M30-antigen and M65-antigen were significantly higher in patients with definitive NASH compared to the other groups. An abnormal value (> 121.60 IU/L) of M30-antigen yielded a 60.0% sensitivity and a 97.4% specificity for the diagnosis of NASH. Sensitivity and specificity of an abnormal M65-antigen level (> 243.82 IU/L) for the diagnosis of NASH were 68.9% and 81.6%, respectively. Among patients with NAFLD, M30-antigen and M65-antigen levels distinguished between advanced fibrosis and early-stage fibrosis with a sensitivity of 64.7% and 70.6%, and a specificity of 77.3% and 71.2%, respectively. CONCLUSION: Serum levels of M30-antigen and M65-antigen may be of clinical usefulness to identify patients with NASH. Further studies are mandatory to better assess the role of these apoptonecrotic biomarkers in NAFLD pathophysiology.

Relationship between adipose tissue dysfunction, vitamin D deficiency and the pathogenesis of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease(NAFLD)is the most common chronic liver disease worldwide.Its pathogenesis is complex and not yet fully understood.Over the years many studies have proposed various pathophysiological hypotheses,among which the currently most widely accepted is the"multiple parallel hits"theory.According to this model,lipid accumulation in the hepatocytes and insulin resistance increase the vulnerability of the liver to many factors that act in a coordinated and cooperative manner to promote hepatic injury,inflammation and fibrosis.Among these factors,adipose tissue dysfunction and subsequent chronic low grade inflammation play a crucial role.Recent studies have shown that vitamin D exerts an immune-regulating action on adipose tissue,and the growing wealth of epidemiological data is demonstrating that hypovitaminosis D is associated with both obesity and NAFLD.Furthermore,given the strong association between these conditions,current findings suggest that vitamin D may be involved in the relationship between adipose tissue dysfunction and NAFLD.The purpose of this review is to provide an overview of recent advances in the pathogenesis of NAFLD in relation to adipose tissue dysfunction,and in the pathophysiology linking vitamin D deficiency with NAFLD and adiposity,together with an overview of the evidence available on the clinical utility of vitamin D supplementation in cases of NAFLD.

Prevalence of HFE mutations and relation to serum (?)ron status in patients with chronic hepatitis C and patients with nonalcoholic fatty liver disease in Taiwan

AIM: To assess the prevalence of the two mutations, C282Y and H63D of HFE gene, in healthy subjects, patients with chronic hepatitis C (CHC), and patients with nonalcoholic fatty liver disease (NAFLD) in Taiwan and to explore the contribution of the HFE mutation on serum iron stores in CHC and NAFLD groups.METHODS: We examined C282Y and H63D mutations of HFE gene in 125 healthy subjects, 29 patients with CHC,and 33 patients with NAFLD. The serum iron markers,including ferritin, iron, and total iron binding capacity (TIBC),were assessed in all patients.RESULTS: All of the healthy subjects and patients were free from C282Y mutation. The prevalence of H63D heterozygosity was 4/125 (3.20%) in healthy subjects, 2/29(6.90%) in CHC group, and 1/33 (3.03%) in NAFLD group.The healthy subjects showed no significant difference in the prevalence of H63D mutation as compared with the CHC or NAFLD group. Increased serum iron store was found in 34.48% of CHC patients and 36.36% of NAFLD patients.In three patients of H63D heterozygosity, only one CHC patient had increased serum iron store. There was no significant difference in the prevalence of HFE mutations between patients with increased serum iron store and those without in CHC or NAFLD group.CONCLUSION: The HFE mutations may not contribute to iron accumulation in the CHC or NAFLD group even when serum iron overload is observed in more than one-third of these patients in Taiwan.

Changes in human hepatic metabolism in steatosis and cirrhosis

AIMTo understand the underlying metabolic changes in human liver disease we have applied nuclear magnetic resonance (NMR) metabolomics analysis to human liver tissue.METHODSWe have carried out pilot study using 1H-NMR to derive metabolomic signatures from human liver from patients with steatosis, nonalcoholic steatohepatitis (NASH) or alcohol-related liver damage (ARLD) to identify species that can predict outcome and discriminate between alcohol and metabolic-induced liver injuries.RESULTSChanges in branched chain amino acid homeostasis, tricarboxylic acid cycle and purine biosynthesis intermediates along with betaine were associated with the development of cirrhosis in both ARLD and nonalcoholic fatty liver disease. Species such as propylene glycol and as yet unidentified moieties that allowed discrimination between NASH and ARLD samples were also detected using our approach.CONCLUSIONOur high throughput, non-destructive technique for multiple analyte quantification in human liver specimens has potential for identification of biomarkers with prognostic and diagnostic significance.

Cost-effectiveness of enhanced liver fibrosis test to assess liver fibrosis in chronic hepatitis C virus and alcoholic liver disease patients

AIM To assess liver fibrosis(LF) in hepatitis C virus(HCV) and alcoholic liver disease(ALD), estimate health outcomes and costs of new noninvasive testing strategies METHODS A Markov model was developed to simulate LF progression in HCV and ALD for a cohort of 40-yearold men with abnormal levels of transaminases. Three different testing alternatives were studied: a single liver biopsy; annual Enhanced liver fibrosis(ELF?) followed by liver stiffness measurement(LSM) imaging as a confirmation test if the ELF test is positive; and annual ELF test without LSM. The analysis was performed from the perspective of a university hospital in Spain.Clinical data were obtained from published literature. Costs were sourced from administrative databases of the hospital. Deterministic and probabilistic sensitivity analyses were performed.RESULTS In HCV patients, annual sequential ELF test/LSM and annual ELF test alone prevented respectively 12.9 and 13.3 liver fibrosis-related deaths per 100 persons tested, compared to biopsy. The incremental costeffectiveness ratios(ICERs) were respectively €13400 and €11500 per quality-adjusted life year(QALY). In ALD, fibrosis-related deaths decreased by 11.7 and 22.1 per 100 persons tested respectively with sequential ELF test/LSM and annual ELF test alone. ICERs were €280 and €190 per QALY, respectively.CONCLUSION The use of the ELF test with or without a confirmation LSM are cost-effective options compared to a single liver biopsy for testing liver fibrosis in HCV and ALD patients in Spain.

Genetic and epigenetic variants influencing the development of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease （NAFLD） is common worldwide. The importance of genetic and epigen- eric changes in etiology and pathogenesis of NAFLD has been increasingly recognized. However, the ex- act mechanism is largely unknown. A large number of single nucleotide polymorphisms （SNPs） related to NAFLD has been documented by candidate gene studies （CGSs）. Among these genes, peroxisome pro- liferatoractivated receptor-γ, adiponectin, leptin and tumor necrosis factor-α were frequently reported. Since the introduction of genome-wide association studies （GWASs）, there have been significant advances in our understanding of genomic variations of NAFLD. Patatin- like phospholipase domain containing family member A3 （PNPLA3, SNP rs738409, encoding I148M）, also termed adiponutrin, has caught most attention. The evidence that PNPLA3 is associated with increased hepatic fat levels and hepatic inflammation has been validated by a series of studies. Epigenetic modification refers to phenotypic changes caused by an adaptive mechanism unrelated to alteration of primary DNA se- quences. Epigenetic regulation mainly includes microR- NAs （miRs）, DNA methylation, histone modifications and ubiquitination, among which miRs are studied most extensively, miRs are small natural single stranded RNA molecules regulating mRNA degradation or translation inhibition, subsequently altering protein expression of target genes. The miR-122, a highly abundant miR ac- counting for nearly 70% of all miRs in the liver, is sig- nificantly under-expressed in NAFLD subjects. Inhibition of miR-122 with an antisense oligonucleotide results in decreased mRNA expression of lipogenJc genes and improvement of liver steatosis. The investigation into epigenetic involvement in NAFLD pathogenesis is just at the beginning and needs to be refined. This review summarizes the roles of genetics and epigenetics in the development of NAFLD. The progress made in this field may provide novel diagnostic biomarkers and therapeu- tic targets for NAFLD management.

Multistep hepatocarcinogenesis from a dysplastic nodule to well-differentiated hepatocellular carcinoma in a patient with alcohol-related liver cirrhosis

We describe a rare case of the transformation of a dysplastic nodule into well-differentiated hepato- cellular carcinoma (HCC) in a 56-year-old man with alcoholrelated liver cirrhosis. Ultrasound (US) disclosed a 10 mm hypoechoic nodule and contrast enhanced US revealed a hypovascular nodule, both in segment seven. US-guided biopsy revealed a high-grade dysplastic nodule characterized by enhanced cellularity with a high N/C ratio, increased cytoplasmic eosinophilia, and slight cell atypia. One year later, the US pattern of the nodule changed from hypoechoic to hyperechoic without any change in size or hypovascularity. US-guided biopsy revealed well-differentiated HCC of the same features as shown in the first biopsy, but with additional pseudoglandular formation and moderate cell atypia. Moreover, immunohistochemical staining of cyclase- associated protein 2, a new molecular marker of well- differentiated HCC, turned positive. This is the first case of multistep hepatocarcinogenesis from a dysplastic nodule to well-differentiated HCC within one year in alcohol-related liver cirrhosis.

Blood F_2-isoprostanes are significantly associated with abnormalities of lipid status in rats with steatosis

AIM: To investigate oxidative stress and lipid peroxi-dation in hepatic steatosis and the underlying implica-tions in pathological mechanisms of non-alcoholic fatty liver disease (NAFLD). METHODS: F_2-isoprostanes (iPF2α-) in blood and liver samples from steatotic (n = 9) and control (n = 7) rats were measured as in vivo marker of lipid peroxida-tion by a mass spectrometric approach. The lipid pro-fi le and endogenous antioxidant status (SOD and CAT) in the rats were also analyzed. RESULTS: Signifi cantly higher levels of iPF2α-(mean 3.47 vs 2.40 pmol/mg tissue, P = 0.004) and lower activities of SOD (mean 1.26 U vs 1.40 U, P < 0.001) and CAT (mean 1026.36 U/mg vs 1149.68 U/mg pro-tein, without signifi cance) were observed in the livers of steatotic rats. Plasma total iPF2α-was signifi cantly correlated with the abnormalities of blood lipids as well as alanine aminotransferase (ALT) levels in the rats with simple steatosis, whereas no similar tendencies were observed in the control rats. CONCLUSION: Enhancement of hepatic oxidative imbalance occurring at the steatotic stage of NAFLD suggests a possibility that manifestation of the local ⅢⅢⅢoxidative damage precedes that of systemic oxidative imbalance. Predominant metabolic features of the in-creased lipid peroxidation further suggest a close asso-ciation of the oxidative imbalance and the dyslipidemia with functional deterioration of the steatotic liver. The fi ndings need to be further evaluated, especially in hu-man studies.

Fibrosis in nonalcoholic fatty liver disease: Noninvasive assessment using computed tomography volumetry

AIM To evaluate the diagnostic performance of computed tomography(CT) volumetry for discriminating the fibrosis stage in patients with nonalcoholic fatty liver disease(NAFLD).METHODS A total of 38 NAFLD patients were enrolled. On the basis of CT imaging, the volumes of total, left lateral segment(LLS), left medial segment, caudate lobe, and right lobe(RL) of the liver were calculated with a dedicated liver application. The relationship between the volume percentage of each area and fibrosis stage was analyzed using Spearman's rank correlation coefficient. A receiver operating characteristic(ROC) curve analysis was performed to determine the accuracy of CT volumetry for discriminating fibrosis stage.RESULTS The volume percentages of the caudate lobe and the LLS significantly increased with the fibrosis stage(r = 0.815, P < 0.001; and r = 0.465, P = 0.003, respectively). Contrarily, the volume percentage of the RL significantly decreased with fibrosis stage(r =-0.563, P < 0.001). The volume percentage of the caudate lobe had the best diagnostic accuracy for staging fibrosis, and the area under the ROC curve values for discriminating fibrosis stage were as follows: ≥ F1, 0.896; ≥ F2, 0.929; ≥ F3, 0.955; and ≥ F4, 0.923. The best cut-off for advanced fibrosis(F3-F4) was 4.789%, 85.7% sensitivity and 94.1% specificity.CONCLUSION The volume percentage of the caudate lobe calculated by CT volumetry is a useful diagnostic parameter for staging fibrosis in NAFLD patients.

Carotid lesions in outpatients with nonalcoholic fatty liver disease

AIM:To ascertain whether carotid lesions are more prevalent in outpatients with incidental findings of nonalcoholic fatty liver disease (NAFLD) at abdominal ultrasound (US).METHODS: One hundred and fifty-four consecutive outpatients (age range 24-90 years, both sexes) referred by general practitioners for abdominal US, and drinking less than 20 g alcohol/day, underwent carotid US for an assessment of carotid intima-media thickness (c-IMT) and carotid plaque prevalence. Hepatic steatosis, visceral fat thickness and subcutaneous fat thickness were also assessed at ultrasonography.RESULTS: Higher c-IMT values were found in the presence of NAFLD (90 patients), even after adjustment for indices of general and abdominal obesity and for the principal cardiovascular risk factors (0.84±0.10 mm vs 0.71±0.10 mm, P<0.001). The prevalence of carotid plaques was 57.8% in the patients with NAFLD vs 37.5% in the patients without this condition (P=0.02). The adjusted relative risk of having carotid plaques for patients with NAFLD was 1.85 (95% CI:1.33-2.57, P<0.001).CONCLUSION: An incidental finding of hepatic steatosis may suggest the presence of silent carotid atherosclerotic lesions.

Sitagliptin in patients with non-alcoholic steatohepatitis: A randomized, placebo-controlled trial

AIMTo evaluate the effect of sitagliptin vs placebo on histologic and non-histologic parameters of non-alcoholic steatohepatitis (NASH).METHODSTwelve patients with biopsy-proven NASH were randomized to sitagliptin (100 mg daily) (n = 6) or placebo (n = 6) for 24 wk. The primary outcome was improvement in liver fibrosis after 24 wk. Secondary outcomes included evaluation of changes in NAFLD activity score (NAS), individual components of NAS (hepatocyte ballooning, lobular inflammation, and steatosis), glycemic control and insulin resistance [including measurements of glycated hemoglobin (HbA1C) and adipocytokines], lipid profile including free fatty acids, adipose distribution measured using magnetic resonance imaging (MRI), and thrombosis markers (platelet aggregation and plasminogen activator inhibitor 1 levels). We also sought to determine the correlation between changes in hepatic fat fraction (%) [as measured using the Iterative Decomposition of water and fat with Echo Asymmetry and Least-squares estimation (IDEAL) MRI technique] and changes in hepatic steatosis on liver biopsy.RESULTSSitagliptin was not significantly better than placebo at reducing liver fibrosis score as measured on liver biopsy (mean difference between sitagliptin and placebo arms, 0.40, P = 0.82). There were no significant improvements evident with the use of sitagliptin vs placebo for the secondary histologic outcomes of NAS total score as well as for the individual components of NAS. Compared to baseline, those patients who received sitagliptin demonstrated improved HbA1C (6.7% &#x000b1; 0.4% vs 7.9% &#x000b1; 1.0%, P = 0.02), and trended towards improved adiponectin levels (4.7 &#x000b1; 3.5 &#x003bc;g/mL vs 3.9 &#x000b1; 2.7 &#x003bc;g/mL, P = 0.06) and triglyceride levels (1.26 &#x000b1; 0.43 mmol/L vs 2.80 &#x000b1; 1.64 mmol/L, P = 0.08). However, when compared with placebo, sitagliptin did not cause a statistically significant improvement in HbA1C (mean difference, -0.7%, P = 0.19) nor triglyceride levels (mean difference -1.10 mmol/L, P = 0.19) but did trend towards improved adiponectin levels only (mean difference, 0.60 &#x003bc;g/mL, P = 0.095). No significant changes in anthropometrics, liver enzymes, other adipocytokines, lipid profile, thrombosis parameters, or adipose distribution were demonstrated. The MRI IDEAL procedure correlated well with steatosis scores obtained on liver biopsy in both groups at baseline and post-treatment, and the Spearman correlation coefficients ranged from r = 0.819 (baseline) to r = 0.878 (post-treatment), P = 0.002.CONCLUSIONSitagliptin does not improve fibrosis score or NAS after 24 wk of therapy. The MRI IDEAL technique may be useful for non-invasive measurement of hepatic steatosis.

博物馆藏品的保管与修复(九)

二、鉄代替銅及青銅而來的是鉄。鉄在自然中分佈的極为廣泛,因为它是地殼主要組成部分之一。如果說人对於鉄的注意是比銅晚些,这正是由於天生的純鉄幾乎不能遇到,而鉄鑛又不像閃光的硫銅黄鉄鑛或者綠色炭銅孔雀石那样有令人注意的特點。此外,鉄的製造本身也比銅的製造困难得許多。