ORIGINAL ARTICLE: Inulin‐coated butyrate increases ileal MCT1 expression and affects mucosal morphology in the porcine ileum by reduced apoptosis

Carbohydrates, which were not digested in the jejunum, will be fermented by micro‐organisms to short chain fatty acids. These are transported by the monocarboxylate transporter 1 (MCT1) through the gut wall and serve as fuels for colonic cells. To deliver butyrate to the distal part of the intestine, inulin with a low precaecal digestibility was chosen as a coating material. Approximately 150 g of inulin‐coated butyrate (containing 81 g butyrate) per day was fed to pigs (mean weight: 97 kg) over a period of 6 days after an adaptation period of 6 days with linear increasing amounts of butyrate. The following observations compared to controls were observed: (1) coating was digested microbially in the ileum; (2) MCT1‐mRNA showed a higher expression in the ileum; (3) apoptosis was reduced in the ileum but mitosis was not changed; and (4) length of villi increased by approximately 25% in the ileum. Feeding inulin‐coated butyrate resulted in an increased ileal surface. Delivery of butyrate to the colon requires a more resistant inulin‐coating.     

Cellular localization of Visudyne® as a function of time after local injection in an in vivo model of squamous cell carcinoma: an investigation into tumor cell death

Objective To evaluate the effects of time on cellular localization of Visudyne^® after local injection. Animals Twenty athymic nude mice. Procedures A squamous cell carcinoma (SCC) cell line (A‐431) was injected into right and left dorsolumbar subcutaneous tissue of each mouse, representing treatment (T) and control (C) tumors. In experiment 1 (Exp 1; n = 10) and 2 (Exp 2; n = 10), the T tumors received a local injection of Visudyne^® (0.1 mg/cm³), and C tumors received an equal dose of 5% dextrose in water (D5W). Mice were randomly subdivided into two groups (A and B; n = 5 per group). Mice in Exp 1A and B were sacrificed 1 and 30 min after local injection, respectively. Experiment 1A and B tumors were evaluated by fluorescence microscopy to determine drug localization. Experiment 2A and B tumors were exposed to LED illumination 1 and 30 min after injection, respectively, and evaluated by transmission electron microscopy (TEM) to determine ultrastructural tumor cell damage. Results Fluorescence was detected within the cytoplasm of T tumors in both Exp 1A and B. Significance was detected in fluorescence intensity between T1 min vs. T30 min (P = 0.03) and between T1 min and C1 min tumors (P = 0.01), respectively. Tumors in Exp 2A and B demonstrated evidence of apoptotic cell death. Conclusions Fluorescence microscopy demonstrated higher Visudyne^® concentration within SCC cytoplasm of 1 min compared with 30‐min tumors. Transmission electron microscopy results revealed that tumors treated by photodynamic therapy (PDT) within 30 min of local injection undergo cellular apoptosis.     

Bisphenol A disrupts granulosa cell function

Because of its widespread use and potential adverse biological effects, bisphenol A (BPA) represents one of the most studied endocrine-disrupting compounds. Within the reproductive system, ovarian granulosa cells have been documented as a target of BPA action, but no consensus has been reached about functional modifications induced by BPA. On these bases, we studied the potential disrupting effects of BPA on the main granulosa cell functional activities, also taking into account a potential interference with the ovarian angiogenic process. Ovarian granulosa cells were isolated from porcine follicles and cultured in the presence or absence of BPA at different concentrations for 48 h. Cell proliferation was studied by measuring adenosine triphosphate content. Progesterone (P4) and estradiol 17β (E2) production was determined by radioimmunoassay. Vascular endothelial growth factor (VEGF) output was quantified by an enzyme-linked immunosorbent assay. Redox status was monitored by measuring superoxide anion and hydrogen peroxide, and by determining the activities of the scavenging enzymes superoxide dismutase, catalase, and peroxidase by colorimetric methods. Granulosa cell proliferation as well as redox status resulted unaffected by BPA. Concentrations of E2 were stimulated by the lower BPA concentration, whereas they were inhibited by the larger doses tested. P4 output was decreased by all BPA concentrations. To the contrary, VEGF production was stimulated. Data indicate that BPA can interfere with reproductive activity by affecting granulosa cell steroidogenesis in vitro; furthermore, BPA can exert a promoting effect on the ovarian angiogenic process by increasing VEGF output in pigs. A disruption of this finely tuned process seems particularly relevant because of the risk of uncontrolled neovascularization.     

细胞色素C在生物医学方面的研究进展

综合论述了细胞色素C的研究简史和结构性质,探讨了细胞色素C与细胞线粒体呼吸链、生物进化细胞凋亡的关系,并对细胞色素C的应用前景作了展望。     

绒山羊肥大细胞类胰蛋白酶的免疫组化及图像分析研究

[目的]探讨绒山羊肥大细胞中是否存在类胰蛋白酶及不同固定液对其常规染色和免疫组化染色结果的影响。[方法]采用兔抗羊肥大细胞类胰蛋白酶多克隆抗体间接免疫过氧化物酶技术检测由Carnoy液和中性福尔马林液(NBF)固定的绒山羊空肠、瓣胃和肺等组织肥大细胞中是否存在类胰蛋白酶。同时采用Image-ProPlus图像分析软件和人工计数法对结果进行分析,比较经常规染色和免疫组化染色后不同固定液固定组织中肥大细胞的形态及数量,进而判断Carnoy液和中性福尔马林液(NBF)对该检测技术的影响。[结果]兔抗羊多克隆抗体与绒山羊肥大细胞中的类胰蛋白酶具有良好的交叉反应,证实绒山羊肥大细胞胞浆颗粒中存在类胰蛋白酶。同时,与Carnoy液相比较,NBF液固定组织能较好地反映肥大细胞在组织中的数量和形态变化。[结论]绒山羊肥大细胞中存在类胰蛋白酶,且与Carnoy液相比较,NBF液是一种更为适合绒山羊肥大细胞常规染色和免疫组化染色的固定剂。     

胰岛素、催乳素和孕酮对奶牛乳腺上皮细胞泌乳功能的影响

具有泌乳功能的乳腺上皮细胞系可作为乳腺发育学、乳腺病理学、泌乳生物工程学研究的细胞模型,本研究测定了激素对奶牛乳腺上皮细胞系泌乳功能的影响,为阐述泌乳机制提供工作基础。应用HPLC方法对体外培养奶牛乳腺上皮细胞的酪蛋白和乳糖的分泌情况和细胞培养液中的酪蛋白、乳糖含量进行测定,以确定胰岛素、催乳素和孕酮处理后的奶牛乳腺上皮细胞的泌乳功能。试验结果表明：奶牛乳腺上皮细胞具有酪蛋白和乳糖的分泌能力,在72h内,随着细胞培养时间延长,胰岛素处理组细胞中的酪蛋白和乳糖的升高趋势不明显,孕酮处理组升高趋势较明显,催乳素处理组升高趋势很明显;胰岛素处理组、催乳素处理组和孕酮处理组细胞培养液中酪蛋白升高趋势均很明显,乳糖含量均很高,三组激素比较而言,胰岛素处理组乳糖含量最高。此外,三组激素对乳腺上皮细胞活力影响均很大,在72h之内,总体变化为：催乳素处理组和孕酮处理组细胞活力均升高,胰岛素处理组细胞活力下降。     

寄生虫细胞因子免疫的研究进展（一）

寄生虫在入侵机体时必须具备逃避机体免疫,破坏宿主免疫屏障才能感染,这种入侵过程必然和宿主机体的免疫系统发生联系,不但使宿主的先天免疫细胞功能缺失,而且获得性免疫也受到抑制。寄生虫感染均不同程度地伴随免疫损伤,宿主在感染寄生虫后产生的免疫应答中,细胞因子作为免疫过程中的介质起到关键作用,主要是调节机体细胞免疫抗虫,保护机体不被感染,其中巨噬细胞是主要功能的承担者。本文将阐述细胞因子在寄生虫感染过程中所发挥的免疫作用,为解决寄生虫感染的防控问题奠定基础,同时为寄生虫的研究提供新的思路。     

细胞凋亡的常用调控基因研究近况

细胞凋亡主要受基因的控制，现已发现许多基因对细胞凋亡均有直接或间接的调控作用。通常将这些基因分为两大类，即细胞生存基因和细胞死亡基因。一般认为与细胞生存有关的基因包括C－myc,C-abl,Ras,V-src,Bcl-2,EIB,LMW5-HL,C-kit和Bcl-x等；与细胞死亡有关的基因包含P^35,P^53,RB,DCC,WT-1,CpGv,Bcr-abl,V-erb-A,tats20,DAD1,ADO/Fas,TGF-β，TRP－2，RP－8，TRPM－2，SGP－2，TIA，Bax,ICE,C-rel,irrecrst等。本文对目前使用较多研究较深入的几种凋亡调控基因，即C－myc基因，Bcl-2基因，P^53基因，ICE基因，Fas基因及FasL和Cdc2基因的来源，作用和相互间关系的研究近况，予以综述，做一简介。     

Muscle reorganisation through local injection of stem cells in the diaphragm of mdx mice

Background

The diaphragm is the major respiratory muscle affected by Duchenne muscular dystrophy (DMD) and is responsible for causing 80% of deaths. The use of mechanical forces that act on the body or intermittent pressure on the airways improves the quality of life of patients but does not prevent the progression of respiratory failure. Thus, diseases that require tissue repair, such as DMD, represent a group of pathologies that have great potential for cell therapy. The application of stem cells directly into the diaphragm instead of systemic application can reduce cell migration to other affected areas and increase the chances of muscle reorganisation. The mdx mouse is a suitable animal model for this research because its diaphragmatic phenotype is similar to human DMD. Therefore, the aim of this study was to assess the potential cell implantation in the diaphragm muscle after the xenotransplantation of stem cells.

Methods

A total of 9 mice, including 3 control BALB/Cmice, 3 5-month-old mdx mice without stem cell injections and 3 mdx mice injected with stem cells, were used. The animals injected with stem cells underwent laparoscopy so that stem cells from GFP-labelled rabbit olfactory epithelium could be locally injected into the diaphragm muscle. After 8 days, all animals were euthanised, and the diaphragm muscle was dissected and subjected to histological and immunohistochemical analyses.

Results

Both the fresh diaphragm tissue and immunohistochemical analyses showed immunopositive GFP labelling of some of the cells and immunonegativity of myoblast bundles. In the histological analysis, we observed a reduction in the inflammatory infiltrate as well as the presence of a few peripheral nuclei and myoblast bundles.

Conclusion

We were able to implant stem cells into the diaphragm via local injection, which promoted moderate muscle reorganisation. The presence of myoblast bundles cannot be attributed to stem cell incorporation because there was no immunopositive labelling in this structure. It is believed that the formation of the bundles may have been stimulated by cellular signalling mechanisms that have not yet been elucidated.