Association of E-cadherin, matrix metalloproteinases, and tissue inhibitors of metalloproteinases with the progression and metastasis of hepatocellular carcinoma.

Molecular markers can provide additional information to traditional histomorphological evaluation for the assessment of tumor progression and predicting the likelihood of invasion and metastasis in various types of malignancies. We studied the association of E-cadherin, matrix metalloproteinases (MMPs), and tissue inhibitors of metalloproteinase with the progression and metastasis of hepatocellular carcinoma. Tissue microarray including six normal livers, 14 cirrhotic livers, 39 macroregenerative nodules, 16 dysplastic nodules, 22 grade I hepatocellular carcinomas, 43 grade II hepatocellular carcinomas, seven grade III hepatocellular carcinomas, and 10 metastatic hepatocellular carcinomas were stained immunohistochemically with antibodies against MMPs -1, -2, -3, -7, -9, tissue inhibitors of metalloproteinase-1, -2, -3, and E-cadherin. The intensities of staining were scored manually by two pathologists and verified by the Chromavision Automated Cellular Imaging System. Compared with normal liver, cirrhotic liver had significantly lower E-cadherin and tissue inhibitors of metalloproteinase-1 but higher MMP-1 and -7, which suggest a more favorable environment for tumor invasion and metastasis. Grade I and grade II hepatocellular carcinomas demonstrated high E-cadherin and decreased MMP-3 and -9, which may explain the rarity of extrahepatic metastasis in low-grade hepatocellular carcinomas despite the high circulatory volume of the liver. The histological progression from dysplastic nodule to well-differentiated hepatocellular carcinoma and to less differentiated tumors was associated with a gradual decrease in tissue expression of E-cadherin, tissue inhibitors of metalloproteinase-2 and -3. Metastatic hepatocellular carcinomas showed significantly lower level of tissue inhibitors of metalloproteinase-1, -2, -3 but higher level of MMP-7. These data suggest that tissue expression of E-cadherin, certain MMPs, and tissue inhibitors of metalloproteinases could be useful markers to predict the progression and metastasis of hepatocellular carcinoma.     

Downregulation of tonic GABA currents following epileptogenic stimulation of rat hippocampal cultures

Deficits in GABAergic inhibitory transmission are a hallmark of temporal lobe epilepsy and have been replicated in animal and tissue culture models of epilepsy. GABAergic inhibition comprises phasic and tonic inhibition that is mediated by synaptic and extrasynaptic GABA_A receptors, respectively. We have recently demonstrated that chronic stimulation with cyclothiazide (CTZ) or kainic acid (KA) induces robust epileptiform activity in hippocampal neurons both in vitro and in vivo . Here, we report a downregulation of tonic GABA inhibition after chronic epileptogenic stimulation of rat hippocampal cultures. Chronic pretreatment of hippocampal neurons with CTZ or KA resulted in a marked reduction in GABAergic inhibition, as shown by a significant decrease in whole-cell GABA currents and in the frequency of miniature inhibitory postsynaptic currents (mIPSCs). Interestingly, synaptically localized GABA_A receptors remained relatively stable, as evidenced by the unaltered amplitude of mIPSCs, as well as the unchanged punctate immunoreactivity of γ2 subunit-containing postsynaptic GABA_A receptors. In contrast, tonic GABA currents, assessed either by a GABA_A receptor antagonist bicuculline or a selective extrasynaptic GABA_A receptor agonist THIP, were significantly reduced following epileptogenic stimulation. These results reveal a novel form of neural plasticity, that epileptogenic stimulation can selectively downregulate extrasynaptic GABA_A receptors while leaving synaptic GABA_A receptors unchanged. Thus, in addition to synaptic alteration of GABAergic transmission, regulation of tonic inhibition may also play an important role during epileptogenesis.     

Synthesis and thermal properties of poly(enaminonitriles) containing flexible ether units

Poly(enaminonitriles) containing flexible alkyl ether units were prepared by reacting p-bis(1-chloro-2,2-dicyanovinyl)benzene with various α,ω-bis(4-aminophenoxy)alkanes in N-methyl-2-pyrrolidone (NMP). All the polymers are soluble in polar aprotic solvents such as N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N,N-dimethylacetamide (DMAc) and NMP as well as in common organic solvents such as tetrahydrofuran and acetone. High molecular weight polymers possessing inherent viscosities in the range of 0.82–1.20 dL/g were obtained and tough films were cast from a DMF solution. They showed a large exotherm around 340°C attributable to the chemical changes of the dicyanovinyl group. Thermogravimetric analyses exhibited a good thermal stability with a 10% weight loss around 450°C and 73–88% residual weight at 500°C under nitrogen.     

Kinetics of the polymerization of isoprene with isopropoxyneodymium dichloride/triethylaluminium binary lanthanide catalyst system

The kinetics of the polymerization of isoprene with the heterogeneous rare earth catalyst system isopropoxyneodymium dichloride/triethylaluminium (Nd(OPrⁱ)Cl₂-AlEt₃) was examined in a specially designed dilatometer. The rate of polymerization is expressed as R_p ≈ ?d[M]/dt = k[Nd]^1.40 [M]. The main kinetical parameters such as the concentration of active propagating chain, the efficiency of lanthanide catalyst used (ELCU), the absolute rate constant of propagation as well as the average life time of growing chains, were determined at 30°C, 40°C, 45°C and 50°C.     

七年制医学生消化内科临床见习带教体会

七年制医学生基础知识扎实、自学能力强,但临床分析和解决问题的实际工作能力欠缺,而临床见习是医学生理论联系实际的纽带和桥梁。因此,努力提高临床见习的带教效果,对于医学生理解、巩固所学基础知识,为临床实习奠定良好的实践基础至关重要。现结合我科多年带教七年制学生见习的具体情况,探讨如何提高七年制医学生临床见习的带教效果。1传统消化内科见习带教中的困难和缺陷消化内科理论课学时多、专业性强,学习内容多、概念抽象,使学生理解较困难。过去见习带教中大部分时间以教师讲课为主,学生多处于被动地位,部分学生出现厌烦、兴趣不浓…     

The NAD(P)H:quinone oxidoreductase I C609T polymorphism modifies the risk of Barrett esophagus and esophageal adenocarcinoma.

PURPOSE: The role of genetic susceptibility to esophageal adenocarcinoma and its precursor lesion Barrett esophagus has not been fully elucidated. This study investigated the effect of polymorphisms in the manganese superoxide dismutase (MnSOD) and NAD(P)H:quinone oxidoreductase 1 (NQO1) genes in modulating the risk of developing Barrett esophagus or esophageal adenocarcinoma. METHODS: A total of 584 patients (146 esophagitis, 200 Barrett esophagus, 144 esophageal adenocarcinoma, and 94 controls) were genotyped for the MnSOD C14T and NQO1 C609T polymorphisms using polymerase chain reaction and restriction fragment length polymorphism analysis. RESULTS: The NQO1 TT genotype was less common in Barrett esophagus (2.0%) and esophageal adenocarcinoma (1.4%) patients, compared with both esophagitis patients (7.6%) and controls (5.4%). After adjustment for sex, age, body mass index, reflux symptoms, and smoking status, patients with the homozygous TT genotype had a 4.5-fold decreased risk of developing Barrett esophagus (odds ratio = 0.22, 95% confidence interval = 0.07-0.76, P = 0.01) and a 6.2-fold decreased risk of esophageal adenocarcinoma (odds ratio = 0.16, 95% confidence intervals = 0.03-0.94, P = 0.04) compared with individuals with the TC and CC genotypes. No significant differences between groups were observed for the MnSOD polymorphism (P = 0.289). CONCLUSIONS: Overall, the results of this study suggest that the NQO1 TT genotype may offer protection from reflux complications such as Barrett esophagus and esophageal adenocarcinoma.     

Diagnostic impact of core-needle biopsy on fine-needle aspiration of non-Hodgkin lymphoma

We retrospectively reviewed 74 fine-needle aspiration (FNA) cases of presumptive non-Hodgkin lymphoma (NHL). All the cases had cytology and core-needle biopsy and 53 cases had concurrent flow cytometric analysis. FNA (cytology and flow cytometry) and core-needle biopsy were evaluated independently. FNA was diagnostic of diffuse large B-cell lymphoma (DLBL) in 25% (13/53) of cases and small B-cell NHL in 15% (8/53) of cases, whereas core-needle biopsy was diagnostic of DLBL in 37% (27/74) of cases and small B-cell NHL in 8% (6/74) of cases. Subclassification of small B-cell NHL was reached in 3/6 cases by core-needle biopsy. Insufficient cases were observed in both FNA (47%; 25/53) and core-needle biopsy (28%; 21/74) groups. With the combination of FNA and core-needle biopsy, diagnostic cases of DLBL increased to 43% (32/74) and insufficient samples were reduced to 16% (12/74). There was no clear advantage in the diagnosis and classification of small B-cell NHL by adding core-needle biopsy to FNA (14%; 10/74). We conclude that core-needle biopsy is a useful adjunct to FNA in the diagnosis of DLBL and shall be encouraged. In small B-cell NHL, core-needle biopsy does not add to the diagnostic ability of FNA. Cases insufficient for diagnosis may be seen in both core-needle biopsy and FNA. A combined approach reduces the number of insufficient cases and is recommended in routine FNA practice.     

Sex-Dependent Effects of 7,8-Dihydroxyflavone on Metabolic Health Are Associated with Alterations in the Host Gut Microbiome

7,8-Dihydroxyflavone (DHF) is a naturally occurring flavonoid that has been reported to protect against a variety of pathologies. Chronic administration of DHF prevents high-fat diet (HFD)-induced obesity in female, but not male, mice. However, the mechanisms underlying this sexual dimorphism have not been elucidated. We have discovered that oral DHF supplementation significantly attenuates fat mass, hepatic lipid accumulation, and adipose tissue inflammation in female mice. In contrast, male mice were not protected from adiposity, and had a paradoxical worsening of hepatic lipid accumulation and adipose tissue inflammation upon DHF supplementation. Consistent with these sexually dimorphic effects on body weight and metabolic health, 7,8-DHF induced early and stable remodeling of the female intestinal microbiome. DHF supplementation significantly increased gut microbial diversity, and suppressed potentially detrimental bacteria, particularly Desulfovibrionaceae, which are pro-inflammatory and positively associated with obesity and inflammation. Changes in the female gut microbiome preceded alterations in body weights, and in silico analyses indicated that these early microbial changes were highly predictive of subsequent weight gain in female mice. While some alterations in the intestinal microbiome were also observed in male DHF-supplemented mice, these changes were distinct from those in females and, importantly, were not predictive of subsequent body weight changes in male animals. The temporality of microbial changes preceding alterations in body weight in female mice suggests a role for the gut microbiome in mediating the sexually dimorphic effects of DHF on body weight. Given the significant clinical interest in this flavonoid across a wide range of pathologies, further elucidation of these sexually dimorphic effects will aid the development of effective clinical therapies.     

充血性心力衰竭治疗前后内皮素，肿瘤坏死因子和血管紧张素转化酶含量比较

目的探讨充血性心力衰竭(CHF)患儿不同心功能级数及分组治疗前后血浆ET、TNF和ACE含量的变化及其意义。方法用放免法和比色法分组测定充血性心力衰竭(CHF)80例患儿血中ET、TNF和ACE含量的变化。结果80例CHF患儿中血中ET、TNF和ACE含量分别为(141.33±8.56)ng/L、(168.25±35.14)ng/L和(429.45±61.33)IU,与正常对照组比较均明显升高(P＜0.05);心功能Ⅱ级与心功能Ⅲ级、心功能Ⅳ级TNF、ET含量间比较均有显著性差异(P＜0.05～0.01),相关有显著性意义;不同心功能级数CHF患儿血浆TNF、ET和ACE含量治疗后较治疗前明显降低,均有显著性差异(P＜0.05～0.01),而且心功能越差,血浆TNF、ET水平恢复越慢,洛汀新组心功能改善较常规组明显,两者含量间比较有显著性差异(P＜0.05)。结论血浆ET、TNP和ACE含量的测定有助于判断心力衰竭的程度,洛汀新组的疗效明显优于常规组。     

磁性阿霉素白蛋白纳米粒的研制

目的：制作具有稳定磁性、能够携带化疗药物的白蛋白纳米粒,并对白蛋白纳米粒的磁性,药物含量进行检测。方法：将市售用Fe3O4粉末,经化学方法处理,制成纳米大小的Fe3O4泥糊,将Fe3O4泥糊、纯盐酸阿霉素、人体血清白蛋白按一定比例混合,通过在棉仔油中超声乳化,加热变性、乙醚洗涤等工艺制作出磁性阿霉素白蛋白纳米粒,用乙醇提取法提取磁性纳米粒中的阿霉素,并用荧光光度计测定含量。将纳米粒溶于生理盐水中,在光学显微镜下观察在磁场作用下磁性纳米粒的运动情况,通过检测溶液中的游离药物,观察在不同的加热温度下,磁性纳米粒的稳定性,并用电子显微镜观察纳米粒的内部结构。结果：磁性白蛋白纳米粒阿霉素含量为57．5μg/g,阿霉素包含率为98．3％,磁性白蛋白纳米溶液在光学显微镜下观察,在磁场的作用下,纳米粒迅速向磁铁的方向移动并发生聚集,当磁铁与纳米粒的距离加大时,纳米粒运动速度减慢,并沿磁力线的方向形成串珠状聚集。电子显微镜下观察,Fe3O4颗粒均匀分布在白蛋白纳米粒中,结论：磁性白蛋白纳米粒具有磁性稳定、靶向性强、药物包含率高、释药速率可控制的特点,为靶向药物治疗提供了可靠的载药工具。