Effect of nutritional route on colonic anastomotic healing in the rat

Although early enteral feeding has been shown to benefit cutaneous healing when compared to parenteral feeding, the effect of the route of nutritional support in gastrointestinal anastomotic healing has not been defined. The aim of the present study was to determine whether the route of nutritional support influences colonic anastomotic healing. Twenty male Sprague-Dawley rats weighing 270 to 290 grams underwent identical surgical manipulation consisting of central venous catheterization, gastrostomy insertion, and distal colonic anastomosis (single-layer, inverted). Identical nutrient infusates composed of 4.25% amino acids, 25% dextrose, and vitamins were administered, with half the animals receiving the infusions via the gastrostomy and the other half via the venous catheter. Animals were killed 5 days after surgery. There were no differences in nutritional parameters between the parenterally and enterally fed groups. Colonic anastomotic bursting pressure was significantly higher in the enterally fed group (180 ±6 vs. 150±11 mm Hg; P<0.01). The measured insoluble collagen and total protein content in anastootic tissue were enhanced in the enterally supported group. The fraction of soluble (newly synthesized) collagen did not differ between the two groups. The data demonstrate that the route of nutrient administration influences colonic anastomotic healing. The preservation of colonic structural collagen in the enteral group may improve the ability of the gut to hold sutures and thus enhance anastomotic healing. Presented at the Thirty-Ninth Annual Meeting of The Society for Surgery of the Alimentary Tract, New Orleans, La., May 17–20, 1998.     

利用CRISPR-Cas9系统敲除小鼠黑色素瘤细胞系MATP基因的初步研究

目的利用CRISPR/Cas9系统,敲除小鼠黑色素瘤细胞系的MATP基因,为MATP基因的功能研究奠定基础。方法利用http://crispr.mit.edu/网站,设计针对MATP的特异性引物,并将引物链接到pCAS9/gRNA1载体。将阳性载体转染小鼠黑色素瘤细胞系B16F10,利用无限稀释的方法获得转染后的单克隆细胞株。提取不同细胞株的基因组,通过测序的方法进一步筛选出发生MATP基因切割的细胞株,并利用Western-blot的方法验证MATP的表达情况。结果成功获得了3株MATP基因敲除的细胞株,Western-blot结果表明,该细胞株不表达MATP蛋白。结论利用pCAS9/gRNA1载体,可以实现B16F10细胞系MATP基因的敲除。     

我省长学制医学教育的回顾与思考

我省七年制医学教育开办了近20年,为社会培养了一批深受欢迎、质量较好和具有较高综合素质的高层次医学人才。建立与我省经济发展水平相适应的以五年制为主体、重点发展八年制的医学教育学制体系,是我省高等医学教育发展的必然趋势。     

Predicting a local recurrence after breast-conserving therapy by gene expression profiling

Introduction

To tailor local treatment in breast cancer patients there is a need for predicting ipsilateral recurrences after breast-conserving therapy. After adequate treatment (excision with free margins and radiotherapy), young age and incompletely excised extensive intraductal component are predictors for local recurrence, but many local recurrences can still not be predicted. Here we have used gene expression profiling by microarray analysis to identify gene expression profiles that can help to predict local recurrence in individual patients.

Methods

By using previously established gene expression profiles with proven value in predicting metastasis-free and overall survival (wound-response signature, 70-gene prognosis profile and hypoxia-induced profile) and training towards an optimal prediction of local recurrences in a training series, we establish a classifier for local recurrence after breast-conserving therapy.

Results

Validation of the different gene lists shows that the wound-response signature is able to separate patients with a high (29%) or low (5%) risk of a local recurrence at 10 years (sensitivity 87.5%, specificity 75%). In multivariable analysis the classifier is an independent predictor for local recurrence.

Conclusion

Our findings indicate that gene expression profiling can identify subgroups of patients at increased risk of developing a local recurrence after breast-conserving therapy.     

Genomic patterns resembling BRCA1- and BRCA2-mutated breast cancers predict benefit of intensified carboplatin-based chemotherapy

Introduction

BRCA-mutated breast cancer cells lack the DNA-repair mechanism homologous recombination that is required for error-free DNA double-strand break (DSB) repair. Homologous recombination deficiency (HRD) may cause hypersensitivity to DNA DSB-inducing agents, such as bifunctional alkylating agents and platinum salts. HRD can be caused by BRCA mutations, and by other mechanisms. To identify HRD, studies have focused on triple-negative (TN) breast cancers as these resemble BRCA1-mutated breast cancer closely and might also share this hypersensitivity. However, ways to identify HRD in non-BRCA-mutated, estrogen receptor (ER)-positive breast cancers have remained elusive. The current study provides evidence that genomic patterns resembling BRCA1- or BRCA2-mutated breast cancers can identify breast cancer patients with TN as well as ER-positive, HER2-negative tumors that are sensitive to intensified, DSB-inducing chemotherapy.

Methods

Array comparative genomic hybridization (aCGH) was used to classify breast cancers. Patients with tumors with similar aCGH patterns as BRCA1- and/or BRCA2-mutated breast cancers were defined as having a BRCA-like^CGH status, others as non-BCRA-like^CGH. Stage-III patients (n = 249) had participated in a randomized controlled trial of adjuvant high-dose (HD) cyclophosphamide-thiotepa-carboplatin (CTC) versus 5-fluorouracil-epirubicin-cyclophosphamide (FE₉₀C) chemotherapy.

Results

Among patients with BRCA-like^CGH tumors (81/249, 32%), a significant benefit of HD-CTC compared to FE₉₀C was observed regarding overall survival (adjusted hazard ratio 0.19, 95% CI: 0.08 to 0.48) that was not seen for patients with non-BRCA-like^CGH tumors (adjusted hazard ratio 0.90, 95% CI: 0.53 to 1.54) (P = 0.004). Half of all BRCA-like^CGH tumors were ER-positive.

Conclusions

Distinct aCGH patterns differentiated between HER2-negative patients with a markedly improved outcome after adjuvant treatment with an intensified DNA-DSB-inducing regimen (BRCA-like^CGH patients) and those without benefit (non-BRCA-like^CGH patients).     

The distribution of erythrocyte phospholipids in hereditary spherocytosis demonstrates a minimal role for erythrocyte spectrin on phospholipid diffusion and asymmetry

In the human erythrocyte membrane phosphatidylcholine and sphingomyelin reside mainly in the outer leaflet, whereas the aminophospholipids, phosphatidylethanolamine and phosphatidylserine, are mainly found in the inner leaflet. Maintenance of phospholipid asymmetry has been assumed to involve interactions between the aminophospholipids and the membrane skeleton, in particular spectrin. To investigate whether spectrin contributes to maintaining the phospholipid transbilayer distribution and kinetics of redistribution, we studied erythrocytes from hereditary spherocytosis patients whose spectrin levels ranged from 34% to 82% of normal. The phospholipid composition and the accessibility of membrane phospholipids to hydrolysis by phospholipases were in the normal range. Spin-labeled phosphatidylserine and phosphatidylethanolamine analogues that had been introduced into the outer leaflet were rapidly transported at 37 degrees C to the inner leaflet, whereas the redistribution of spin-labeled phosphatidylcholine was slower. The kinetics of transbilayer movement of these spin-labeled phospholipid in all samples was in the normal range and was not affected by the level of spectrin. Although these erythrocyte membranes contained as little as 34% of the normal level of spectrin and were characterized by several physical abnormalities, the composition, distribution, and transbilayer kinetics of the phospholipids were found to be normal. We therefore conclude that spectrin plays, at best, only a minor role in maintaining the distribution of erythrocyte membrane phospholipid.     

肝癌患者血清外泌体内miR-665的表达及临床意义

[摘 要] 目的 探讨肝癌患者血清来源的外泌体内miR-665与肝癌临床病理指标及预后的关系。方法 采用试剂盒方法提取患者血清内的外泌体并用透射电镜观察验证。然后利用RT-PCR方法检测30例肝癌患者和10例体检者血清来源的外泌体内miR-665的表达水平,进行对照研究,探讨临床病理指标和预后的关系。结果 血清提取的外泌体呈囊泡状,直径约30～150 nm。肝癌患者血清来源的外泌体miR-665较正常体检者表达水平明显升高,中位表达水平是对照组的8.3倍。外泌体miR-665高表达与患者肿瘤大小（>5 cm） （P=0.0042）、有包膜浸润（P=0.0197）以及临床TNM分期（III～IV期） （P=0.0276）成明显相关,与患者年龄、性别、HBsAg以及AFP水平未见明显相关性（P > 0.05）,外泌体miR-665高表达组患者生存期较低表达组更短（P=0.036）。结论 肝癌患者血清中外泌体miR-665水平升高与肝癌进展相关,测定血清外泌体内miR-665的水平可能有助于肝癌的临床诊断和预后判断。     

心脏瓣膜病合并感染性心内膜炎的外科治疗

目的探讨心脏瓣膜心内膜炎的临床特点、手术时机选择和围术期处理。方法回顾分析26例心脏瓣膜病合并感染性心内膜炎的临床表现、治疗经过和临床预后。结果术前死于恶性心力衰竭1例,术后随访25例,随访时间3个月～6年,无术后死亡,无再发感染。结论心脏瓣膜病合并感染性心内膜炎外科治疗风险大,死亡率高,正确掌握手术指征、术中彻底清除感染灶和围术期正确处理是治疗的关键。