Effects of tumor necrosis factor,endothelin and nitric oxide on hyperdynamic circulation of rats with acute and chronic portal hypertension

AIM:To evaluate the effect of tumor necrosis factor (TNF),endothelin (ET) and nitric oxide (NO) on hyperdynamic circulation (HC) of rats with acute and chronic portal hypertension (PHT).METHODS: Chronic portal hypertension was induced in Wistar rats by injection of carbon tetrachloride. After two weeks of cirrhosis formation, L-NMMA (25mg/kg) was injected into one group of cirrhotic rats via femoral vein and the experiment was begun immediately. Another group of cirrhotic rats was injected with anti-rat TNFα (300mg/kg) via abdominal cavity twice within 48h and the experiment was performed 24h after the second injection. The blood concentrations of TNFα, ET-1 and NO in portal vein and the nitric oxide synthase (NOS) activity in hepatic tissue were determined pre-and post-injection of anti-rat TNFα or LNMMA. Stroke volume (SV), cardiac output (CO), portal pressure (PP), superior mesenteric artery blood flow (SMA flow) and lilac artery blood flow (IAflow) were measured simultaneously. Acute portal hypertension was established in Wistar rats by partial portal-vein ligation (PVL). The parameters mentioned above were determined at 0.5h,24h, 48h, 72h and 120h after PVL. After the formation of stable PHT, the PVL rats were injected with anti-rat TNFα or L-NMMA according to different groups, the parameters mentioned above were also determined.RESULTS:In cirrhotic rats, the blood levels of TNFα, NO in portal vein and the liver NOS activity were significantly increased (P<0.05) while the blood level of ET-1 was not statistically different (P>0.05) from the control animals(477.67±83.81pg/mL vs 48.87±32.79pg/mL, 278.41±20.11μmol/L vs 113.28±14.51μmol/L, 1.81±0.06μ/mg.prot vs 0.87±0.03μ/mg.prot and 14.33±4.42pg/mL vs8.72±0.79pg/mL, respectively). After injection of anti-rat TNFα,the blood level of TNFα was lower than that in controls (15.17±18.79pg/mL vs 48.87±32.79pg/mL). The blood level of NO and the liver NOS activity were significantly decreased, but still higher than those of the controls. The blood level of ET-1 was not significantly changed. PP,SV,CO, SMAflow and IAflow were ameliorated. After injection of L-NMMA, the blood level of NO and the liver NOS activity were recovered to those of the controls. PP and CO were also recovered to those of the controls. SV, SMAflow and IAflow were ameliorated. In PVL rats, the blood levels of TNFα NO in portal vein and the liver NOS activity were gradually increased and reached the highest levels at 48h after PVL. The blood level of ET-1 among different staged animals was not significantly different from the control animals. PP among different staged animals (2.4±0.18kPa at 0.5h, 1.56±0.08kPa at 24h, 1.74±0.1kPa at 48h,2.38±0.05 kPa at 72h, 2.39±0.16 kPa at 120h) was significantly higher than that in controls (0.9±0.16kPa). After injection of anti-rat TNFα in 72h PVL rats, the blood level of TNFα was lower than that in controls (14±14pg/mL vs 48.87±32.79pg/mL). The blood level of NO and the liver NOS activity were significantly decreased, but still higher than those of the controls. The blood level of ET-1 was not significantly changed. PP was decreased from 2.38±0.05kPa to 1.68±0.12kPa, but significantly higher than that in controls. SV, CO, SMAflow and IAflow were ameliorated.After injection of L-NMMA in 72h PVL rats, the blood level of NO and the liver NOS activity were recovered to those of the controls. PP, SV, CO, SMAflow and IAflow were also recovered to those of the controls.CONCLUSION:NO plays a critical role in the development and maintenance of HC in acute PHT and is a key factor for maintenance of HC in chronic PHT. TNFα may not participate in the hemodynamic changes of HC directly, while play an indirect role by inducing the production of NO through activating NOS. No evidence that circulating ET-1 plays a role in both models of portal hypertension has been found.

RELATIONSHIP BETWEEN ENDOTHELIAL DYSFUNCTION AND SERUM HOMOCYSTEINE IN PATIENTS WITH CORONARY LESIONS

Objective To investigate the relationship between vascular endothelial dysfunction and serum homocysteine (HCY) level in patients with coronary lesions. Methods Serum HCY, serum nitric oxide (NO), plasma endothelin-1 (ET-1), and circulation endothelial cell (CEC) were measured in 76 patients who received coronary angiography. Fifty-four patients with a stenosis of 50% or more at least in one coronary atery were as coronary artery disease (CAD) group. Other 22 cases with no recognizable plaque and/or stenosis were as control group. HCY level was detected using an enzyme immunoassay kit. NO concentration was measured using a nitrate reductase kit. Radio-immunoassay was applied to analyse the ET-1 level, and CEC was measured by flow cytometry. Results The levels of HCY, ET-1, and CEC in patients with coronary lesions were significantly increased in comparison with control group (P < 0.01), while NO level in CAD group was significantly lower compared with that in control (P < 0.01). Using a multivariate stepwise regression analysis, HCY level had a positive correlation with ET-1 level (r = 0.420, P < 0.05) and CECs number (r = 0.423, P < 0.05); and had a negative correlation with NO/ET-1 (r = -0.403, P < 0.05). But there was no significant correlation between HCY and NO levels. Conclusions HCY might lead to endothelial cell injury, which would provide a plausible mechanism for the relationship between hyperhomocysteinemia and development of coronary artery disease. HCY can be considered as a predictor for preli-minary or active coronary lesion.

VASCULAR ENDOTHELIAL INJURIES AND CHANGES OF BLOOD COAGULATION AND FIBRINOLYSIS INDEXES IN PATIENTS WITH ACUTE RESPIRATORY DISTRESS SYNDROME

Objective To study endothelial damage by observing changes of circulating endothelial cells (CECs) in blood, coagula-tion and fibrinolysis index in patients with acute respiratory distress syndrome. Methods CECs were separated by isopycnic centrifugation method in 14 patients with acute lung injury (ALI), 7 patients with acute respiratory distress syndrome (ARDS), 10 intensive care unit (ICU) controls, and 15 healthy controls. Plasma prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FG), fibrin degradation products (FDP), and D-dimer were examined simultaneously. Acute physiology and chronic health evaluation (APACHE)Ⅱand lung injury score (LIS) were recorded to evaluate severity of illness and lung injury. Results (1) The number of CECs in ALI (10.4 ±2.3) and ARDS groups (16.1 ±2.7) was higher than that in the healthy (1.9 ±0.5) (P< 0.01). In both ALI and ARDS, the number of CECs correlated with APACHEⅡ(r=0.55, P< 0.05 and r=0.62, P< 0.05, respectively)and LIS (r=0.60, P< 0.05 and r=0.53, P< 0.05, respectively). CEC number was negatively correlated with PaO 2 in ALI and ARDS (r=-0.49, P< 0.05 and r=-0.64, P< 0.05, respectively). (2) The level of FDP and D-dimer were higher in ALI and ARDS patients than that in ICU and healthy control groups (P< 0.05). The level of FG in ARDS group was significantly higher than in the ICU and healthy control groups (P< 0.05). But in ALI group, the level of FG was significantly higher than only healthy control group (P< 0.05). Conclusions Endothelial cell damage occurs in ARDS patients, which may play a major role in the pathophysiology of ARDS. Changes of endothelial cell activation and damage markers, such as CECs, plasma coagulation and fibrinolysis index, to some extent reflect severity of illness and lung injury in ARDS.

Effect of early enteral and parenteral nutrition on visceral ischemic lesion of rat burn model

AIM:To compare the effects of early enteral nutrition and early parenteral nutrition on ameliorating visceral ischemia and relieving free radical damage.METHODS:66 Wistar rats were divided into 3 groups: control group(C),parenteral nutrition group(PN)and enteral nutrition group(EN),PN and EN groups made up of 30%TBSAⅢdegree burn model.We delivered nutrient solution with same calorie and calorie nitrogen ratio via vein or enteral tract respectively.Blood flow of liver,kidney and change of SOD of heart,liver and kidney at 6,12,24,48,72 h after burn were tested.RESULTS:Tissue blood flow and SOD of EN group were higher than those of PN group in many phase(P< 0.05-0.01).CONCLUSION:Early enternal nutrition can relieve the increase of visceral vascular permeability and damage of oxygen free radical.

Transforming Growth Factor-β_2 Gene Cloning and Protein Expression in Human Trabecular Meshwork Cells

Whether cultured human trabecular meshwork cells express transforming growth factor-β 2 (TGF-β 2) messenger RNA (mRNA) and protein was investigated. Total RNA of 10 6 cultured human trabecular meshwork cells was extracted with TRIZOL reagent, reverse transcriptase-polymerase chain reaction (RT-PCR) were used for detection of TGF-β 2 messenger RNA, and the PCR product was verified by sequencing. Immunohistochemical staining was used to detect TGF-β 2 protein. The results showed that a single RT-PCR amplified product was obtained, and the sequence was homologous to the known sequence. TGF-β 2 immunostaining was positive. It was concluded that trabecular meshwork cells could produce TGF-β 2 and contribute to the presence of TGF-β 2 in trabecular meshwork microenvironment as well as aqueous humor. Trabecular meshwork cells were affected by TGF-β 2 not only through paracrine, but also autocrine action. Whether abnormal changes in TGF-β 2 production contribute to the pathogenesis of primary open-angle glaucoma is worth further investigation.

Effects of L-Tetrahydropalmatine on NOSⅢ Gene Expression in Hypoxia and Cultured Porcine Cerebral Arterial Endothelial Cells during Reoxygenation

To investigate the expression of NOSⅢ mRNA and protein in cultured porcine cerebral arterial endothelial cells (CAEC) during hypoxia and reoxygenation and the effects of L-Tetrahydropalmatine (L-THP) on the gene expression of NOSⅢ in CAEC during hypoxia and reoxygenation. The cultured CAEC were divided into 5 groups: control, hypoxia, hypoxia+reoxygenation, hypoxia+L-THP and reoxygenation+L-THP groups. NOSⅢ mRNA expression was detected by reverse transcription-polymerase chain reaction (RT-PCR). Immunocytochemistry was used to detect the level of NOSⅢ protein. The expression of NOSⅢ mRNA and protein were increased when CAEC were exposed to hypoxia for 1 h, and significantly decreased during reoxygenation 2, 6 and 12 h after 1-h of hypoxia. L-THP from 10 -8 mol/L to 10 -3 mol/L could inhibit the up-regulation of NOSⅢ gene expression during hypoxia and down-regulation of NOSⅢ gene expression during reoxygenation.

Antiviral Effects of Interferons and Their Therapeutic Potentials for SARS

Viruses are obligatory intracellular parasites. Most of the cells in animaland human body possess the innate ability to fight viruses. Innate immune function restrictsinfection at the early stage and delay spread of virus. The early stage of infection is the stage ofinteraction between the virus and the host's defence system. Once the latter is breached, the earlynon-specific or innate immune components such as interferon (IFN), natural killer (NK) cells andmacrophages become active. As the infection proceeds, the adaptive (specific) immune responsedevelops, with the appearance of cytotoxic T cells, helper T cells and antiviral antibodies.Antibodies provide a major barrier to virus spread between cells and cells and are particularlyimportant in restriction of virus spread in the blood stream. Virus infection directly activates thetranscription of type Ⅰ IFN (IFN-alfa/beta) genes in infected cells, while the type Ⅱ IFN(IFN-gamma) plays an essential role in the regulation of an adaptive immune response rather thaninnate immune response. Therefore, Type Ⅰ IFN is the first defence for host and neighbouring cellsto resist virus infection.

THE EXPRESSIONS AND SIGNIFICANCES OF p15,p16 AND VASCULAR ENDOTHELIAL GROWTH FACTOR (VEGF) IN GASTRIC CARCINOMA

To investigate the relationships between the expressions of p15,p16 and vascular endothelial growth factor (VEGF) and gastric carcinoma(GC). Methods: Using Immunohistochemical staining to examine the expressions of p15, p16 and VEGF In archival wax-embedded specimens of 80 GC and 20 gastric benign disease (GBD). Results: The positive expression rate (PER) of p15 was significantly lower in GC than in GBD (43.75% VS. 69.23%, P<0.05). No relationship was found between PER of p15 and clinicopathologic factors. PER of p16 was 20% in GC, 55% in GBD (P<0.01). PER of p16 wasn't significantly different in gross types, histological types, with or without distant metastasis and pTNM stages. PER of p16 was 71.43% in invasive mucosa or submucosa group, 17.24% in invasive muscle group and 13.64% in invasive serosa group (P<0.01); 12.96% in GC with lymph nodes metastasis, 34.62% in GC without lymph node metastasis (P<0.05). PER of VEGF in GC was 75.00%, in GBD 7.69% (P<0.001), in ul-cerative type of GC and infiltrating

脂肪酸结合蛋白2基因多态性与2型糖尿病

Objective To investigate the association between the polymorphism of codon-54 of the fatty acid binding protein 2 (FABP2) gene and patients with type 2 diabetes, and how to infect metabolism of lipoprotein. Methods The Ala54Thr variation of FABP2 was detected by PCR and Hae-Ⅱ digestion in 225 Chinese subjects, including 117 cases of type 2 diabetes mellitus and 108 cases of normal controls. All cases were detected for fasting plasma lipoprotein. Results (1)The polymorphism restriction site of codon-54 of FABP2 gene results in the substitution of threonine(Thr) for alanine(Ala). Of the 117 diabetic patients screened, 64 (54.7%) were heterozygous, 32 (27.4%) were homozygous for Ala-54 allele and 21 (17.9%) were homozygous for the Thr-54 allele. (2)The frequence of genotype Ala54/Thr54 and Thr54/Thr54 significiantly increased in the type 2 diabetes as compared with that in healthy subjects (P:0.018).(3)The odds ratio of FABP2 genotype Ala54/Thr54 and Thr54/Thr54 for the patients with type 2 diabetes was 1.97(95% confidence intervals is 1.13-3.44). (4)The frequency of the FABP2 mutant thr54 allele was similar in men and women (33.3% and 32.0%, respectively, P=0.675). (5)The patients with type 2 diabetes who carry Ala54/Thr54 and Thr54/Thr54 genotype had a significantly higher level of fasting plasma triglyceride (P=0.003) and lower level of high density lipoprotein cholesterol (HDL-C) (P=0.001)than those with the wild-type. Conclusions (1)FABP2 gene polymorphism seems to be significantly associated with type 2 diabetes; the codon-54 of mutant genotypic frequencies were in Hardy-Weinberg equilibrium. (2)The FABP2 ala54thr polymorphism appears to have no significant difference in men and women. (3)FABP2 polymorphism may have a certain contribution to the abnormity of lipoprotein metabolism in individuals.

Autologous mesenchymal stem cells transplantation in adriamycin-induced cardiomyopathy

Recent studies have suggested benefits of mesenchymal stem cells ( MSCS) transplantation for the regeneration of cardiac tissue and function improvement of regionally infracted myocardium, but its effects on global heart failure is still little known. This study suggested the capacity of MSCs to transdifferentiate to cardiac cells in a nonischemic cardiomyopathic setting, and the effect of the cells on heart function.