The effects of aspirin on gastric mucosal integrity, surface hydrophobicity, and prostaglandin metabolism in cyclooxygenase knockout mice

BACKGROUND & AIMS: Insight into the role of the different cyclooxygenase isoforms in prostaglandin biosynthesis, surface hydrophobicity, and gastric mucosal barrier integrity can be gained by comparing the effects of luminal damaging agents in wild-type and cyclooxygenase knockout mice. METHODS: Fasted wild-type, cyclooxygenase-1, and cyclooxygenase-2 knockout mice were intragastrically administered saline, 0.6N HCl, or aspirin (aspirin 20 mmol/L) in combination with 0.6N HCl and killed 1 hour later, at which time the gastric lesion score was assessed and biopsy samples were taken for surface, biochemical, and morphological analyses. RESULTS: The gastric mucosa of cyclooxygenase-1 knockout mice was more severely injured by both HCl alone and aspirin/HCl than that of wild-type and cyclooxygenase-2 knockout mice. HCl alone and aspirin/HCl also induced a more profound decrease in surface hydrophobicity in cyclooxygenase-1 knockout mice than in wild-type mice, whereas this surface property was unaffected in cyclooxygenase-2 knockout mice. The gastric injury induced by aspirin/HCl in cyclooxygenase-1 knockout mice could be prevented if the animals were treated with phosphatidylcholine-associated aspirin. Aspirin/HCl, in comparison to saline or HCl alone, induced a 4-6-fold increase in gastric mucosal prostaglandin E(2) concentration in the cyclooxygenase-1 knockout mice, whereas it decreased prostaglandin E(2) levels in wild-type and cyclooxygenase-2 knockout mice. This paradoxical aspirin-induced increase in gastric prostaglandin E(2) in cyclooxygenase-1 knockout mice seemed to correspond to an increase in cyclooxygenase-2 messenger RNA and protein expression. The gastric lesion score seemed to be significantly associated with alterations in surface hydrophobicity but not with mucosal prostaglandin E(2) concentration. CONCLUSIONS: Our evidence on cyclooxygenase knockout mice suggests that aspirin predominantly causes gastric injury by a non-prostaglandin mechanism, perhaps by attenuating surface hydrophobicity, a possibility supported by the low gastric toxicity of phosphatidylcholine/aspirin. However, prostaglandins generated by cyclooxygenase-1 may play an important permissive role in maintaining gastric mucosal barrier integrity. Aspirin seems to paradoxically increase the gastric mucosal prostaglandin E(2) concentration in cyclooxygenase-1 knockout mice, possibly by the induction of cyclooxygenase-2.     

Protocol driven palliative care consultation: Outcomes of the ENABLE CHF-PC pilot study

Background

Little has been reported about protocol-driven outpatient palliative care consultation (OPCC) for advanced heart failure (HF).

Protective effect of bone marrow mesenchymal stem cells on PC12 cells apoptosis mediated by TAG1

Objective: This study aims to explore the protection effect of bone marrow mesenchymal stem cells (BMSCs) on PC12 cells apoptosis mediated by transient axonal glycoprotein 1 (TAG1). Methods: PC12 cells were divided into control group, Aβ_25-35 group and BMSCs + Aβ_25-35 group. The effects of BMSCs on PC12 cells treated by Aβ_25-35 were detected using MTT, Hoechst 33258 and Annexin V-FITC/PI staining methods. The expression levels of TAG1, β-amyloid precursor protein (APP), AICD and p53 were determined by RT-PCR and Western blotting methods. The expression levels of Bax and Bcl-2 were determined by Western blotting method. The activity of Caspase 3 was detected by spectrophotometric method. Results: MTT results showed that cell activity decreased after the treatment of 20 μM Aβ_25-35 for 48 h (P<0.01) while it increased in BMSCs + Aβ_25-35 group (P<0.01). Hoechst 33258 and Annexin V-FITC/PI staining results showed that Aβ_25-35 could induce the apoptosis of PC12 cells while the apoptosis of PC12 cells was inhibited in BMSCs + Aβ_25-35 group. RT-PCR and Western blotting methods showed that 20 μM Aβ_25-35 could increase the expression levels of TAG1, APP, AICD and p53 (P<0.01) while they decreased in BMSCs + Aβ_25-35 group (P<0.01). 20 μM Aβ_25-35 could increase the expression levels of Bax and decrease the expression levels of Bcl-2 (P<0.01), while the expression levels of Bax decreased and the expression levels of Bcl-2 increase in BMSCs + Aβ_25-35 group (P<0.01). 20 μM Aβ_25-35 could enhance Caspase 3 activity while it decreased in BMSCs + Aβ_25-35 group (P<0.01). Conclusions BMSCs with Aβ_25-35 could inhibit the apoptosis of PC12 cells, which maybe related with TAG1/APP/AICD signal pathway.     

miRNA-9过表达对Aβ损伤的PC12细胞的保护作用

目的:探讨micro RNA-9(mi R-9)过表达对β-淀粉样蛋白(Aβ)损伤的PC12细胞及B淋巴细胞瘤-2(Bcl-2)、Bcl-2相关x蛋白(Bax)表达的影响。方法:PC12细胞分为mi R-9过表达组(E组)、空转染对照组(NC组)、不转染的损伤细胞模型组(NT组),采用CCK-8法检测细胞增殖;采用Annexin-V-PE检测细胞凋亡;采用RT-q PCR检测Bcl-2、Bax m RNA的表达,Western-Blot检测Bcl-2、Bax蛋白表达。结果:与NC组及NT组比较,E组的PC12细胞转染48 h后增殖增加,凋亡率降低,Bcl-2表达增加,Bax表达下降(P0.05)。结论:mi R-9过表达可保护Aβ损伤的PC12细胞。     

Different metabolic profiles of K1 serotype and non-serotype K1 and K2 Klebsiella pneumoniae isolates in oral infection mice model

K1 or K2 serotype Klebsiella pneumoniae isolate caused clinical pyogenic liver abscess (KLA) infection is prevalent in many areas. It has been identified that K1 or K2 serotype K. pneumoniae isolates caused KLA infection in mice by oral inoculation. In our study, K1 serotype K. pneumoniae isolate Kp1002 with hypermucoviscosity (HV)-positive phenotype caused KLA infection in C57BL/6 mice by oral inoculation. Simultaneously, non-serotype K1 and K2 isolate Kp1014 with HV-negative phenotype failed to cause KLA infection in the same manner. It seems that gastrointestinal tract translocation is the pathway by which K1 or K2 serotype K. pneumoniae caused KLA infection. Liquid chromatography-tandem mass spectrometry was used to further analyze metabolic profile changes in mice with KLA infection. Data showed that after Kp1002 or Kp1014 oral inoculation, serum Phosphatidylcholine (PC) and Lysophosphatidylcholine (LPC) levels significantly changed in mice. Some PC and LPC molecules showed changes both in the Kp1002 KLA group and the Kp1014 no-KLA group compared with the control group. The level of 18:1/18:2-PC significantly changed in the Kp1002 KLA group compared with the control group, but showed no change between the Kp1014 no-KLA group and the control group. The level of 18:1/18:2-PC might have been particularly affected by KLA infection caused by K1 serotype K. pneumoniae Kp1002. It may be a potential biomarker for KLA infection.     

去甲乌药碱对过氧化氢引起的PC12细胞损伤的保护作用研究

目的 探讨去甲乌药碱对过氧化氢(H₂O₂)引起的PC12细胞损伤的保护作用。方法 将PC12细胞分为对照组、H₂O₂组(100 μM H₂O₂)、去甲乌药碱组(50 μM去甲乌药碱+100 μM H₂O₂),CCK8法检测细胞活力,TUNEL染色检测细胞凋亡情况,流式检测ROS水平,氧化应激标志物MDA、SOD分别采用TBA法和WST法检测,蛋白免疫印迹检测凋亡相关蛋白Caspase3、Bax和Bcl-2的表达情况。结果 与H₂O₂组比较,去甲乌药碱组细胞活力显著提高,ROS、MDA含量显著降低,SOD活性显著升高,Caspase3、Bax表达量减少,Bcl-2表达量增加。结论 去甲乌药碱能通过抗氧化及抗凋亡抑制H₂O₂引起的PC12细胞损伤。     

隐丹参酮上调GRP78抑制谷氨酸诱导的PC12细胞凋亡

目的：探讨隐丹参酮(Cryptotanshinone, CTS)对谷氨酸(glutamate, Glu)诱导的神经元凋亡的影响及潜在的作用机制。方法：取生长状态良好的PC12细胞,用1 μmol/L Glu处理,Western Blot检测细胞中凋亡相关蛋白Bax、Bcl2的表达水平;以CTS(5 μmol/L或10 μmol/L)预处理PC12细胞12 h后,再用Glu刺激12 h,采用TUNEL染色分析CTS对Glu诱导PC12细胞凋亡的影响;Western Blot检测CTS预处理前后Glu刺激的PC12细胞中糖蛋白调节78(78 ku glucose-regulated protein, GRP78)的蛋白表达水平,并通过sh-RNA干扰细胞内GRP78表达,观察细胞活力的变化。结果：Glu可诱导PC12细胞凋亡,抑制胞内GRP78的表达;经CTS预处理后Glu诱导的神经元凋亡现象得到缓解,GRP78表达增加;干扰PC12细胞内GRP78表达后,可逆转CTS的抗凋亡作用。结论：CTS可通过上调GRP78的表达从而保护PC12细胞抵抗Glu诱导的细胞凋亡。     

Tamoxifen induces resistance to activated protein C

Introduction

The estrogen antagonist tamoxifen (TAM) increases the thrombotic risk similar to estrogen containing oral contraceptives (OC). In OC users this risk is attributed to alterations of hemostasis resulting in acquired resistance to activated protein C (APC). TAM-induced APC resistance has not been reported yet.

Materials and Methods

Blood samples were collected prospectively from women with breast cancer before (n = 25) and monthly after start of adjuvant TAM treatment (n = 75). APC resistance was evaluated on basis of the effect of APC on the endogenous thrombin generation potential. To detect increased in vivo APC generation APC plasma levels were measured using a highly sensitive oligonucleotide-based enzyme capture assay. Routine hemostasis parameters were measured additionally.

Results

APC sensitivity decreased by 41% (p = 0.001) compared to baseline after one month of TAM application and remained significantly decreased during the study period. Free protein S increased (p = 0.008) while other analyzed procoagulant factors, inhibitors, and activation markers of coagulation decreased or did not change significantly. In five patients the APC concentration increased to non-physiological levels but an overall significant increase of APC was not observed.

Conclusions

This is the first study showing acquired APC resistance under TAM therapy. Acquired APC resistance might explain the increased thrombotic risk during TAM treatment. Observed changes of hemostasis parameters suggest different determinants of TAM-induced APC resistance than in OC-induced APC resistance. The presence of acquired APC resistance in TAM patients warrants further evaluation if these patients may benefit from antithrombotic prophylaxis in the presence of additional thrombotic risk factors.     

Evaluation and performance characteristics of the Q Hemostasis Analyzer, an automated coagulation analyzer

The Q Hemostasis Analyzer (Grifols, Barcelona, Spain) is a fully-automated random-access multiparameter analyzer, designed to perform coagulation, chromogenic and immunologic assays. It is equipped with a cap-piercing system. The instrument was evaluated in a hemostasis laboratory of a University Hospital with respect to its technical features in the determination of coagulation i.e. prothrombin time (PT), activated partial thromboplastin time (aPTT), thrombin time, fibrinogen and single coagulation factors V (FV) and VIII (FVIII), chromogenic [antithrombin (AT) and protein C activity] and immunologic assays [von Willebrand factor antigen (vWF:Ag) concentration], using reagents from the analyzer manufacturer. Total precision (evaluated as the coefficient of variation) was below 6% for most parameters both in normal and in pathological ranges, except for FV, FVIII, AT and vWF:Ag both in the normal and pathological samples. No carryover was detected in alternating aPTT measurement in a pool of normal plasma samples and in the same pool spiked with unfractionated heparin (> 1.5 IU/mL). The effective throughput was 154 PT, 66 PT/aPTT, 42 PT/aPTT/fibrinogen, and 38 PT/aPTT/AT per hour, leading to 154 to 114 tests performed per hour, depending of the tested panel. Test results obtained on the Q Hemostasis Analyzer were well correlated with those obtained on the ACL TOP analyzer (Instrumentation Laboratory), with r between 0.862 and 0.989. In conclusion, routine coagulation testing can be performed on the Q Hemostasis Analyzer with satisfactory precision and the same apply to more specialized and specific tests.     

Increased thrombin generation in splanchnic vein thrombosis is related to the presence of liver cirrhosis and not to the thrombotic event

Introduction

In recent years there have been increasing evidence associating liver disease with hypercoagulability, rather than bleeding. The aim of the study was to evaluate the haemostatic potential in patients with liver disease.

Patients and methods

We measured thrombin generation in the presence and absence of thrombomodulin in patients with portal vein thrombosis (PVT, n = 47), Budd-Chiari syndrome (BCS, n = 15) and cirrhosis (n = 24) and compared the results to those obtained from healthy controls (n = 21). Fifteen patients with PVT and 10 patients with BCS were treated with warfarin and were compared to an equal number of patients with atrial fibrillation matched for prothrombin time-international normalized ratio. We assessed resistance to thrombomodulin by using ratios [marker measured in the presence/absence of thrombomodulin].

Results

There were no differences in thrombin generation between patients on warfarin treatment and their controls. Cirrhotic patients generated more thrombin in the presence of thrombomodulin and exhibited thrombomodulin resistance compared to controls [p = 0.006 for endogenous thrombin potential (ETP) and p < 0.001 for peak thrombin and both ratios ETP and peak] and patients with non-cirrhotic PVT (p = 0.001, p = 0.006, p < 0.001, p < 0.001 for ETP, peak, ratio ETP, ratio peak, respectively). The patients with cirrhotic PVT exhibited higher ETP (p = 0.044) and peak (p = 0.02) in the presence of thrombomodulin than controls, as well as thrombomodulin resistance (ETP and peak ratios: p = 0.001).

Conclusions

Hypercoagulability and thrombomodulin resistance in patients with cirrhosis were independent of the presence of splanchnic vein thrombosis. The hypercoagulability in patients with cirrhotic PVT could have implications for considering longer or more intensive treatment with anticoagulants in this group.