Localization of urinary procoagulant in the human kidney.

By the indirect immunofluorescent and immunoenzymatic techniques with monospecific antiserum against urinary procoagulant (a tissue factor which accelerates blood coagulation), we found the urinary procoagulant in the kidney distributed to the loop of Henle and distal convoluted tubules. In these areas urinary procoagulant was found in association with the luminal and intercellular borders as well as in the cytoplasm of epithelial cells. Both the descending and ascending limbs of Henle were equally stained. The cytoplasmic staining was patchy in distribution among cells of distal tubules and was predominantly localized in the supranuclear areas. Glomeruli, the proximal tubular cells, the vascular wall, and the interstitium were not stained. There was, however, fluorescent staining along the epithelial layers of the Bowman's capsule, which was observed only in the frozen sections. Casts in the distal tubules were also positively stained. These findings suggest that urinary procoagulant is synthesized in the epithelial cells of these particular parts of nephron and is secreted into urine, although its physiologic roles and pathologic significance are not entirely known.     

Hypoxia induces procoagulant activity in cultured human venous endothelium

Although it normally presents a nonthrombogenic surface, endothelium is capable of procoagulant activity and suppression of native anticoagulant properties. We theorized that hypoxia could shift normal endothelium into a procoagulant state and tested this hypothesis in cultured human umbilical venous endothelial cells. Human umbilical venous endothelial cells were obtained from fresh umbilical cords. Passage two cells were placed in control (PO2 greater than 120 mm Hg) or hypoxic (PO2 less than 60 mm Hg) media and incubated in control or hypoxic environments for 24 hours. In additional experiments, cells were reoxygenated for 4 or 48 hours after the initial hypoxic period. Cells were then assayed for procoagulant activity expressed as thromboplastin unit equivalents per 100,000 cells based on a thromboplastin standard curve. Results are expressed as percent increase in thromboplastin unit equivalents/100,000 cells +/- standard error versus control. Statistical significance was assessed by paired t test with p less than 0.05 considered significant. More than 95% of cells in all experimental and control preparations were viable after completion of the protocols. No morphologic variation was noted among the control and hypoxic groups. For cells rendered hypoxic without reoxygenation, the mean increase in procoagulant activity for the group (n = 4) versus control was 77% +/- 13% (p = 0.01). In the hypoxia and 4-hour reoxygenation group (n = 4), the mean increase in procoagulant activity was 141% +/- 43% (p less than 0.05). In cells reoxygenated for 48 hours after hypoxia (n = 8), the mean increase in procoagulant activity was 198% +/- 34% (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Hemodynamic characterization of porcine hemorrhagic pancreatitis ascites fluid

The hemodynamic reactions of hemorrhagic pancreatitis ascites fluid (HAF) were observed after intravascular injection in the pig. The HAF vascular reactions were compared to the reactions of known vasoactive agents in hopes of identifying the vasoactive agent(s) in HAF. Pancreatitis was induced in five pigs with pancreatic ductal injection of a bile/trypsin mixture. HAF from these pigs was injected into the portal vein of five anesthetized pigs which were monitored for changes in femoral artery pressure (FAP), cardiac output (CO), and portal pressure (PoVP). Trypsin was also tested in the same way in five additional pigs. HAF elevated PoVP, then lowered VAP, depressed CO, and exhibited tachyphylaxis. Trypsin did not cause tachyphylaxis. The effects observed after infusion of HAF are similar to the reported effects observed after injecting histamine, an agent previously implicated in hemorrhagic pancreatitis.     

Monocyte procoagulant activity and plasminogen activator. Role in human renal allograft rejection

Currently the mechanism of renal allograft rejection is not well understood. This study was designed to determine whether induction of monocyte procoagulant activity (MCPA) is important in the pathogenesis of renal allograft rejection. The MPCA assay was performed utilizing a one stage clotting assay both in normal and in factor-VII-deficient plasma. There was no increase in spontaneous MPCA in 20 patients with endstage renal failure and in 10 patients following abdominal or orthopedic operation, as compared with 20 normal controls. MPCA was assessed daily in 18 patients who had received renal allografts. Rejection episodes (RE) were predicted on the basis of persistent elevation in MPCA as compared with pretransplant levels. Rejection was diagnosed clinically and treated on the basis of standard criteria. Treated RE were compared with those predicted by elevated MPCA, and 3 patients were assessed as having no RE by MPCA and by standard criteria. In 8 RE, MPCA correlated temporally with RE (same day) when compared with standard criteria. In 12 RE, MPCA was predictive of rejection preceding standard criteria by at least 24 hr. There were 7 false-positive predictions on the basis of MPCA; however, there was only 1 false negative. MPCA was shown to be a prothrombinase by its dependence only on prothrombin and fibrinogen for full activity. MPCA may be important in the pathogenesis of allograft rejection, and additionally it may be a useful adjunct in the clinical management of this disease.     

Urinary procoagulant and fibrinolytic activity in human glomerulonephritis. Relationship with renal function

Fibrin deposition in kidney is a common event in some forms of human and experimental glomerulonephritis, and is thought to result from local activation of blood coagulation and/or impaired removal by the fibrinolytic system. We studied the urinary procoagulant and fibrinolytic activities in 46 patients with renal disease (26 with IgA nephritis, 13 with other forms of glomerulonephritis and 7 with non-inflammatory kidney disease) and in 15 matched healthy subjects, as possible indicators of the coagulation-fibrinolysis balance in kidney. Procoagulant activity was slightly but not significantly increased in patients with serum creatinine levels higher than 1.5 mg/dl (group II) as compared with patients with normal creatinine (group I) and controls. It was identified as tissue factor by biological criteria (dependence on factor VII). Fibrinolysis studies showed that both plasminogen activator activity and urokinase antigen were significantly lower in group II than in group I patients and controls (P less than 0.0005). Reduced fibrinolytic activity in patients' urine was due to decreased excretion of urokinase since no inhibitor was detected by both fibrin autography and functional assay. No differences were found between patients and controls in plasma fibrinolytic activity, plasminogen activator inhibitor, and procoagulant activity of blood monocytes. The urinary changes in severe renal disease may reflect an unbalance of the coagulation-fibrinolysis equilibrium in kidney and might be of pathogenetic and clinical relevance.     

人骨保护素在CHO细胞内初步稳定表达

目的构建人OPG的稳定表达载体,并在DHFR-型CHO细胞内稳定表达。方法用RT-PCR的方法获得人全长OPG的编码基因,并将其克隆入载体pcDNA3.1-DHFR/CT-GFP,鉴定无误后,转染DHFR-型CHO细胞,经MTX筛选获得阳性表达OPG的细胞株。结果成功构建人OPG的稳定表达载体,并获得阳性表达OPG的细胞株。结论全长人OPG基因可以在CHO细胞内成功稳定表达,这为OPG的功能研究及临床应用奠定物质基础。     

The characterization of the tidemark in human articular cartilage

The tidemark has been characterized in fourteen human diarthrodial joints using histochemical and biochemical techniques. It stained selectively for lipid as well as for the enzymes alkaline phosphatase and ATPase. Preliminary biochemical data has shown a high concentration of calcium phospholipid phosphate complexes.     

Protein leak from normal vasculature due to human malignant ascites

Malignant ascites is an accumulation of protein rich fluid (a filtrate of whole blood) in the peritoneal cavity of patients with abdominal malignancies. The normal peritoneal microvasculature of the cremaster muscle of rats, with the nerve and blood supply intact, was visualized before and after exposure of the tissue to human malignant ascites fluid and to human plasma. In vivo fluorescent microscopy was used to quantitate leakage of fluorescent-tagged albumin. Exposure of the abluminal side of the vasculature to malignant ascitic fluid and plasma causes significant protein leakage from the small veins to the interstitial space. This suggests that the continued production of malignant ascites may be caused by a positive feedback system, which is related to factors present in a normal plasma filtrate. These factors can induce leakage of protein by an effect on the abluminal side of the normal peritoneal microvasculature.     

3Y-TZP全瓷材料体外细胞毒性试验(MTT法)

目的：初步评价牙科全瓷材料3Y-TZP生物相容性。方法：根据ISO标准采用体外细胞毒实验（MTT法）测试不同浓度和浸提时间的材料浸提液L-929小鼠结缔组织成纤维细胞的影响从而对全瓷材料3Y-TZP的生物相容性进行初筛。结果：各浓度组0D值均与阴性对照无显著性差异（P〉0．05），与阳性组差异显著（P〈0．01），材料毒性级别0级。结论：两种材料体外细胞毒实验阴性，初步认为材料具有较好的生物相容性。     

Hernia repair in the presence of ascites

Background

The model for end-stage liver disease (MELD) has been validated as a prediction tool for postoperative mortality, but its role in predicting morbidity has not been well studied. We sought to determine the role of MELD, among other factors, in predicting morbidity and mortality in patients with nonmalignant ascites undergoing hernia repair.

Methods

All patients undergoing hernia repair in the American College of Surgeons National Surgical Quality Improvement database (2009–11) were identified. Those with nonmalignant ascites were compared with patients without ascites. A subset analysis of patients with nonmalignant ascites was performed to evaluate the association between MELD and morbidity and mortality with adjustment for potential confounders. The association of significant factors with the rate of morbidity was displayed using a best-fit polynomial regression.

Results

Of 138,366 hernia repairs, 778 (0.56%) were performed on patients with nonmalignant ascites. Thirty-day morbidity (4% versus 19%) and mortality (0.2% versus 5.3%) were significantly more frequent in patients with ascites (P < 0.001). In univariate analysis of the 636 patients with a calculable MELD, MELD was associated with both morbidity and mortality (P < 0.001 each). In multivariate analysis, MELD remained significantly associated with morbidity (odds ratio [OR] = 1.11). Ventral hernia repair (OR = 2.9), dependent functional status (OR = 2.3), alcohol use (OR = 2.3), emergent operation (OR = 2.0) white blood count (OR = 1.1), and age (OR = 1.02) were also significantly associated with morbidity (P < 0.05).

Conclusions

Before hernia repair, the MELD score can be used to risk-stratify patients with nonmalignant ascites not only for mortality but also morbidity. Morbidity rates increase rapidly with MELD above 15, but other factors should additionally be accounted for when counseling patients on their perioperative risk.     

纳米结构PCL—b—PLLA材料特性及其与犬软骨细胞的生物相容性研究

目的探讨具有纳米结构的聚己内酯／左旋聚乳酸共聚物（PCL—b—PLIJA）作为半月板组织工程支架的可行性，及其与犬软骨细胞的体外生物相容性。方法开环聚合制备PCL-b-PLLA，液-液相分离技术制备纳米结构PCL—b—PLLA支架，固-液相分离技术制备PCL—b—PLLA支架，扫描电镜（SEM）观察材料结构；测定纳米结构支架体外降解率及力学强度。分离培养犬软骨细胞，取第3代软骨细胞接种于纳米结构PCL—b—PLIA（实验组）、PCL—b—PLLA（对照组）支架材料上进行三维培养6d，SEM观察软骨细胞的形态、粘附、生长状况；细胞支架复合培养3、6、12d后，Hoechst33258荧光法检测复合物中细胞DNA含量、BCA法测定蛋白质含量。结果实验组支架材料相对分子量150kD，压缩强度为72．6KPa，孔隙率为93％。SEM示实验组支架表面为多孔状，孔壁为纤维网状连接。其降解率起初始较慢，8周后降解速率明显加快。软骨细胞在实验组支架上粘附、增殖优于对照组。随时间延长细胞在支架材料上DNA和蛋白质含量逐渐增加，实验组DNA和蛋白质含量均明显高于对照组（P〈0．01，P〈0．05）。结论具有纳米结构的PCL-b—PILA支架具有良好的生物力学性能及可降解性，可显著促进细胞粘附、增殖及合成代谢，有望成为一种较为理想的半月板组织工程支架材料。