Detection of oncogenes in chronic pancreatitis

BACKGROUND: The pathogenesis of chronic pancreatitis (CP) remains poorly understood. Recently, molecular biology has identified the genetic background for many patients with hereditary CP. In addition, a number of studies have focused on the detection of proto-oncogenes and tumour suppressor gene mutations in the pathogenesis of CP. So far, the use of these mutations (with the exception of mutations causing hereditary CP), as diagnostic and prognostic markers is still controversial. DISCUSSION: It is well known that the risk of pancreatic cancer in patients with CP, especially the hereditary form, is high. At present, there is insufficient evidence to show a clear relationship between the development of pancreatic cancer and certain mutations. New biotechnological methods, such as DNA array expression analysis, expand our knowledge of the molecular pathogenesis of this disease and may help to develop specific diagnostic, prognostic and therapeutic tools. However, until long-term studies examine the safety and efficacy of certain genetic markers, long-term follow-up of patients with CP who harbour mutations is needed.     

Desensitization pattern of cardiac β-adrenoceptor subtypes by prolonged in vivo infusion of pindolol and celiprolol in rats

Summary The regulatory effects of pindolol and celiprolol on cardiac -adrenoceptor density were studied in vivo in order to assess the subtype selectivity of their partial agonistic activity (PAA). The substances were continuously administered to rats for 1 week by means of implanted osmotic minipumps. The density of -adrenoceptor subtypes were estimated from ICYP saturation binding experiments performed on cardiac ventricular plasma membranes in the presence of a highly selective antagonist (CGP 20172 A or ICI 118,551). Both antagonists were employed at concentrations as high as to block one subtype only without affecting the complementary subtype. For control purposes, rats were also treated with isoprenaline (0.4 mg/kg/h) and propranolol (0.15 mg/kg/h), or vehicle. Pindolol (0.036 mg/kg/h) and celiprolol (0.36 mg/kg/h) reduced the density of ventricular ₂-adrenoceptors by 46% and 23%, respectively, which — in the case of pindolol — was significant when compared to the non-treated controls. Both compounds, however, produced a small, but distinct increase in the number of ₁-adrenoceptors by approximately 26%. This finding is in contrast to the propranolol-induced upregulation of both ₁- and ₂-adrenoceptors by approximately 80%. Since supramaximal doses of each drug were administered, a significant smaller increase of ₁-adrenoceptors by pindolol and celiprolol —as compared to the increase produced by propranolol — can be interpreted as evidence for a PAA of pindolol and celiprolol on ₁-adrenoceptors as well. Isoprenaline as a full agonist caused a marked loss of of both -adrenoceptor subtypes. Although it exhibits equal affinity at both subtypes the decrease amounted to 80% of the ₂- but only to 54% of the ₁-adrenoceptors density. This indicates that the down-regulation of cardiac -adrenoceptors in general seems to be more pronounced at the ₂-than at the ₁-adrenoceptors population. We conclude that the subtype desensitization pattern of agents with intrinsic activity precludes the determination of subtype-selectivity, since ₁- and ₂-adrenoceptors appear to differ in their sensitivity presumably as a result of subtype specific baseline desensitization produced by endogenous catecholamines.     

3D matrix‐embedding inhibits cycloheximide‐mediated sensitization to TNF‐alpha‐induced apoptosis of human endothelial cells

The programmed form of cell death (apoptosis) is essential for normal development of multicellular organisms. Dysregulation of apoptosis has been linked with embryonal death and is involved in the pathophysiology of various diseases. Others and we previously demonstrated endothelial biology being intertwined with biochemical and structural composition of the subendothelial basement membrane. We now demonstrate that a three‐dimensional growing environment significantly shields endothelial cells from cytokine‐induced apoptosis. Detailed analysis reveals differences in intracellular signaling pathways in naive endothelial cells and cytokine‐stimulated endothelial cells when cells are grown within a three‐dimensional collagen‐based matrix compared to cells grown on two‐dimensional tissue culture plates. Main findings are significantly reduced p53 expression and level of p38‐phosphorylation in three‐dimensional grown endothelial cells. Despite similar concentrations of focal adhesion kinase, three‐dimensional matrix‐embedded endothelial cells express significantly less tyrosine‐phosphorylated focal adhesion kinase. Pretreatment with antibodies against integrin α_vβ₃ partially reversed the protective effect of three‐dimensional matrix‐embedding on endothelial apoptosis. Our findings provide detailed insights into the mechanisms of endothelial apoptosis with respect to the spatial matrix environment. These results enhance our understanding of endothelial biology and may otherwise help in the design of tissue‐engineered materials. Furthermore, findings on focal adhesion kinase phosphorylation might enhance our understanding of clinical studies with tyrosine kinase inhibitors.     

Generation and characterization of highly purified canine Schwann cells from spinal nerve dorsal roots as potential new candidates for transplantation strategies

Schwann cells are promising candidates for transplantation strategies in the central nervous system by promoting axonal regeneration. The dog represents a translational model for human spinal cord injury (SCI) for studies with new repair strategies after intervertebral disk herniation (IVDH). To overcome the necessity for an additional surgical procedure, for the first time a protocol for the isolation and purification of canine Schwann cells from spinal nerve biopsies during standard hemilaminectomy in IVDH‐affected paraplegic dogs for potential transplantation has been developed. Purity was assessed by flow cytometry. The results were compared with biopsies from dogs without SCI. Within 26 ± 4 days, 90.2 ± 8.8% p75 neurotrophin receptor (p75^NTR)‐positive cells were achieved in IVDH dogs. The total cell count in acute/subacute and chronic IVDH (acute/subacute: 6.82 ± 6.36 × 10⁶; chronic: 2.29 ± 2.00 × 10⁶) differed significantly (p = 0.0120) at the potential time point of transplantation. No differences in culture period and purity were detected between dogs with and without IVDH. Despite the small sample size and the altered environment, the isolation of Schwann cells was successful. Negative influences on isolation and purification due to potential pathological changes at the biopsy site of IVDH‐diseased dogs were ruled out by comparison of Schwann cell pellets from diseased and control dogs. Finally, the functionality of Schwann cells from dogs with IVDH was outlined in co‐culture experiments with canine dorsal root ganglion neurons. In conclusion, nerve root biopsies provide a sufficient number of highly purified and functional Schwann cells within a useful time period for novel therapeutic strategies in dogs with SCI.     

Effect of age on the sensitivity of the rat thyroid gland to ionizing radiation

Exposure to ionizing radiation during childhood is a well-known risk factor for thyroid cancer. Our study evaluated the effect of age on the radiosensitivity of rat thyroid glands. Four-week-old (4W), 7 -week-old (7W), and 8-month-old (8M) male Wistar rats were exposed to 8 Gy of whole-body X-ray irradiation. Thyroids were removed 3–72 h after irradiation, and non-irradiated thyroids served as controls. Ki67-positivity and p53 binding protein 1 (53BP1) focus formation (a DNA damage response) were evaluated via immunohistochemistry. Amounts of proteins involved in DNA damage response (p53, p53 phosphorylated at serine 15, p21), apoptosis (cleaved caspase-3), and autophagy (LC3, p62) were determined via western blotting. mRNA levels of 84 key autophagy-related genes were quantified using polymerase chain reaction arrays. Ki67-positive cells in 4W (with high proliferative activity) and 7W thyroids significantly decreased in number post-irradiation. The number of 53BP1 foci and amount of p53 phosphorylated at serine 15 increased 3 h after irradiation, regardless of age. No increase in apoptosis or in the levels of p53, p21 or cleaved caspase-3 was detected for any ages. Levels of LC3-II and p62 increased in irradiated 4W but not 8M thyroids, whereas expression of several autophagy-related genes was higher in 4W than 8M irradiated thyroids. Irradiation increased the expression of genes encoding pro-apoptotic proteins in both 4W and 8M thyroids. In summary, no apoptosis or p53 accumulation was noted, despite the expression of some pro-apoptotic genes in immature and adult thyroids. Irradiation induced autophagy in immature, but not in adult, rat thyroids.     

p16、p53、Ki-67和血清SCC-Ag在宫颈鳞癌中的表达及意义

目的 探讨p16、p53、Ki-67和血清鳞状细胞癌抗原(squamous cell carcinoma antigen, SCC-Ag)在宫颈鳞癌患者中的表达及意义。方法 采用免疫组织化学法检测31例宫颈鳞癌与31例宫颈炎组织中p16、p53、Ki-67的表达,同时采用化学发光微粒子免疫法检测治疗前的血清SCC-Ag水平。结果(1) 宫颈炎和宫颈鳞癌中p16、p53、Ki-67、SCC-Ag的阳性率分别为0%、0%、12.9%、0%和96.8%、48.4%、100%、71%,两组比较有显著差异(P<0.05)。(2) p53高表达与淋巴结或脉管转移有关,Ki-67表达随组织学分级升高而升高,血清SCC-Ag水平随临床分期升高而升高(P<0.05)。(3) 经Spearman等级相关分析,p16染色强度与血清SCC-Ag水平呈正相关(r=0.467,P<0.05),在临床Ⅰ期宫颈鳞癌中,两者间正相关更显著(r=0.59,P<0.05)。结论 P53、Ki-67、血清SCC-Ag与宫颈鳞癌发展的恶性程度相关,其在表达上的差异与肿瘤生物学行为有一定关系,宫颈鳞癌在发生发展过程中,尤其是早期阶段,p16与血清SCC-Ag可能有协同作用。     

降逆护膜汤对DCA诱导食管黏膜上皮细胞凋亡中p38MARK信号通路的影响

目的 观察降逆护膜汤体外对脱氧胆酸(DCA)诱导人正常食管黏膜上皮细胞HEEC凋亡中p38MAPK相关基因表达的影响,探讨降逆护膜汤治疗胃食管反流病的机制.方法 通过体外培养人正常食管上皮细胞,经DCA诱导出现凋亡现象,采用MTT法观察不同浓度的降逆护膜汤对细胞凋亡的影响.运用westem blot检测细胞凋亡与p38MAPK的关系.结果 MTT显示与正常对照组相比,DCA使细胞生存率明显降低(P＜0.01),而降逆护膜汤提高生存率,与DCA组比较有统计学意义(P＜0.05).蛋白检测结果显示,降逆护膜汤能显著抑制细胞凋亡模型中p38MAPK的磷酸化水平,提高bcl-2/bax表达量来发挥抗凋亡作用.结论 降逆护膜汤可通过抑制p38MAPK的磷酸化水平来发挥其抗凋亡作用.     

Safety,Pharmacokinetics, and Pharmacodynamics of ME-401, an Oral,Potent, and Selective Inhibitor of Phosphatidylinositol 3-Kinase P110δ, Following Single Ascending Dose Administration to Healthy Volunteers

Purpose

ME-401 is a novel selective inhibitor of phosphatidylinositol 3 kinase p110δ, an enzyme often found overexpressed and overactive in B-cell malignancies. The current study was performed to assess the safety, tolerability, pharmacokinetics, and pharmacodynamics of single ascending oral doses of ME-401 in healthy volunteers.

Ki-67 p53蛋白在乳腺癌病理组织中的表达及临床意义

目的：检测Ki-67、p53蛋白在乳腺癌病理组织中的表达情况,探讨其临床诊断意义。方法采用免疫组化法检测65例乳腺癌病理组织及12例乳腺良性病变中Ki-67、p53蛋白的表达情况。结果 Ki-67、p53蛋白在乳腺癌病理组织中的阳性表达率分别为90.77%,53.85%,在乳腺良性病变中阳性表达率分别为0%,0%,两者差异有统计学意义（P<0.01）;Ki-67、p53蛋白的阳性表达率与临床分期、有无淋巴结转移均密切相关（P<0.01）。结论联合检测Ki-67、p53蛋白的表达,对乳腺癌与良性病变的鉴别及预后判断具有重要的参考价值。     

miRNA-126-3p 与先天性心脏病肺动脉高压发病机制相关性的临床研究

目的：探讨 miRNA-126-3p 与肺动脉高压（以下简称肺高压）发病机制的相关性。方法选取25例先天性心脏病患者,其中,肺高压患者11例,对照组14例,采用 qRT-PCR 法检测其肺组织 miRNA-126-3p 的表达,并采用 starBase 进行靶基因预测,并从 mRNA 水平和蛋白水平进行验证。结果肺高压患者与对照组在年龄、性别、生化指标检查等方面比较差异无统计学意义（P＞0．05）;肺高压患者 miRNA-126-3p 表达水平与对照组比较差异有统计学意义（P＜0．01）;生物信息学预测发现 miRNA-126-3p 的生物学功能主要与结合蛋白、信号转导、细胞分化、调控细胞形态、调控 MAPK 和胰岛素受体信号通路等有关,其靶基因主要有 VEGFA 、SPRED1、PIK3R2等;肺高压组的 VEGFA 表达在 mRNA 水平和蛋白水平与对照组比较差异有统计学意义（P＜0．01）;miRNA-126-3p 与 VEGFA 呈现正相关（P＜0．01）。结论 miRNA-126-3p 可能通过调控 VEGFA 参与先天性心脏病相关性肺动脉高压发病。