Objective To observe the effects of lysophosphatidic acid(LPA) on arrhythmia in acute myocardial infarction(AMI) rats.Methods AMI models were prepared by ligating the left coronary branch of rats.60 Wistar rats were divided into 5 groups:sham-operated(SO),AMI,AMI+LPA,AMI+pertussis toxin(PTX) and(AMI+)PTX+LPA.ECG were recorded,HR and VPBs were observed as important indexes.Results Incidence of tachycardia and VPBs of unit time in AMI group were increased compared with sham-operated group(P

Objective To investigate the therapeutic effect of a new surgical procudure for intractable pnumothorax.Methods Subaxillary mini-incision and folding ligation of bullae of lung were conducted without suture if possible.Parietal pleura was rubbed with a dry gauze roll and irrigated with hydrogen peroxide solution.The corresponding pulmonary segments were suspended on the parietal pleura to keep the lung tissues in inflation state and to avoid over compression of the lungs.Pleural cavity was irrigated with 5-10 ml lidocaine for 3 days after the surgery.Results The operation was successfully conducted in 21 cases(including 1 case of bilateral surgery).The average operation time was 45 min(range:30-60 min);and the average blood loss was 70 ml(range:50-100 ml).No complications occurred.The follow-up time was 6-72 months,25 months in average,and no recurrence of pneumothorax occurred.Conclusions This therapeutic method combining subaxillary mini-incision,suspension of pulmonary lobe,folding ligation and general adhesion is effective,minimally invasive,safe and inexpensive for treating intractable pnumothorax.

Objective To analyse the detective rate and significance in diagnosis of cerebral and meningeal metastases by MR.Methods 115 cases with cerebral and meningeal metastasis were proved by operation and pathology.There were male 86 and females 29 ranged in age from 17-77 years old,plain MR scan and enhanced MR scan were performed in all cases.Results In this group included 46 cerebral metastases(40.0%),33 meningeal metastasis(28.7%),36 both cerebral and meningeal metastases(31.3%). Different degree of enhancement was showed on enhanced MRI in all cases, "mouse tail signs"or"target signs" were appeared in which cerebral metastasis with the adjoining meninges involved.Conclusion MRI is a good method for diagnosing cerebral and meningeal metastasis.Enhanced MRI has an important value.

Objective To analyse the MRI appearances of giant cell tumors of the bone and the relationship with their pathologic bases.Methods Histologic examinations were conducted in 21 cases,and their correlations with the MRI appearances were further evaluated.Results There were 3 cases of the Ⅰ grade,3 cases of the Ⅰ～Ⅱ grade,13 cases of the Ⅱ grade,2 cases of the Ⅲ grade of the giant cell tumors.Most tumors were composed of solid content that presented sligthly low to intermediate signal intensity on T 1WI,sligthly high to high signal intensity on T 2WI.The minority of the tumors were composed of the half of the solid and cystic contents expectively.Specific tumors was mainly composed of cystic content or combined with fluid-fluid level on T 2WI.Soft tissue masses were found in 8 cases.Conclusion The location and their extension into the soft tissue of the tumors can be clearly demonstrated on MR imaging,but there is no relationship between the grades of the tumors and their MRI appearances.

Objective To evaluate the clinical value of rotational digital subtraction angiography(DSA).Methods The rotational DSA was performed 48 cases in 30 patients with PHILIPS V5000 digital imaging system.Among them,cerebral(n=8),carotid(n=2),limbs(n=7),hepatic(n=2),pulmonary(n=1),iliac(n=2),aortic(n=1),renal(n=2)and uterine(n=5)arteries were included.Results The origins,running,distributions,numbers and contours of diseased segments of arteries and pseudoaneurysm were clearly displayed in 28 of 30 patients with the technique of RDSA.Conclusion The RDSA is very useful in the preoperative diagnosis and selection of treatment for the diseased arteries.

Objective To evaluate the influence of lumbar disc herniation type on the curative effect of percutaneous lumbar discectomy (PLD). Methods 158 patients were classified into two groups including contained and discontained herniation according to clinical symptoms and diagnostic images. They were treated by meanes of the same technique in nonvascular intervention. Their curative effects were compared with each other in this study. Results The curative and total effective rates were 81.1% and 98.5% respectively in contained group, 7.7% and 38.5% in discontained group without serious complications. The duration of follow up ranged from 3 months to 73 months. Conclusions PLD is a effective procedure for lumbar disc herniation, which is relatively simple and safe with rapid recovery and without serious complications. It should be confirmed in simple contained herniation only.

Objective To investigate the effects of hyperbaric oxygen (HBO) on the expression of caveolin2 and matrix-metalloproteinase-9 (MMP-9) in brain tissues and the blood brain barrier (BBB) after cerebral ischemia and reperfusion (I/R) in rats. Methods Three hundred and seventy male Wistar rats were randomly assigned into sham,ischemia-reperfusion,HBO,and I/R + HBO groups. After creating cerebral I/R models,oxygen at 0.25 MPa was administered 5 times,and 2％ Evans blue (EB) was injected into the tail veins 1 h before the rats were sacrificed.The permeability of the BBB,the expression of caveolin-2 and MMP-9,and EB content were determined by Western blotting,immunohistochemistry,and spectrophotometery,respectively. Results In the I/R group,the EB content increased steadily to a peak at 4 hours.EB content in the IR + HBO group was significantly lower than in the I/R group.Caveolin-2 and MMP-9 were significantly augmented by I/R injury at the 24th,48th and 72nd hours.Compared to the I/R group,HBO intervention decreased their expression levels. Conclusion HBO intervention can reverse the increase of caveolin-2 and MMP-9 caused by I/R injury,which suggests a mechanism for protective effects of HBO on the permeability of the BBB in I/R injury.

BACKGROUND: Gene therapy is a popular topic in domestic and overseas studies on biological therapy for brain tumor.OBJECTIVE: By using a newly constructed eukaryotic expression vector of pCR3-TK, the effect of the HSV-TK/ACV system on the proliferative activity of human glioma cells was investigated.DESIGN: Experimental study based on cells.SETTING: Department of neurosurgery and department of oncology in a university hospital.MATERIALS: The study was conducted at the National Key Laboratory of Veterinary Biotechnology of Harbin Veterinary Research Institute from January to April in 2004. The eukaryotic expression vector of pCR3-TK was constructed by the author. The TJ905 strain was a gift from professor Pu Pei-yu, who worked in the Neurology Institute of Tianjin city. The nontransfected cells and the cells transfected with pCR3-Uni vector were set as controls.METHODS: By using Lipofectamine(a cationic liposome), the pCR3-Uni vector and the recombinant pCR3-TK plasmid(inserted with HSV-TK gene)were transfected into the human glioma cell strain-TJ905. Then the positive clones were picked out and were given ACV(50 mg/L) . Totally 72 hours later, the cover slips were collected and silver staining for nucleolus organizer regions(AgNORs) was performed.MAIN OUTCOME MEASURES: After the ACV treatment and AgNORs staining, the numbers of silver-stained granules in TJ905 cells with or without transfections were counted respectively.RESULTS: In those cells transfected with HSV-TK gene, after ACV treatment, a significant decreasing in proliferative activity could be observed, and the average numbers of the silver-stained granules in cells transfected with pCR3-Uni or pCR3-TK were 14.33 and 6.67 respectively( P ＜ 0.01).CONCLUSION: As an easy-to-operate method, AgNOR counting is helpful for the studies on the proliferative activity of cells and the investigations into the potential anti-tumor mechanism of the HSV-TK/ACV system.

OBJECTIVE To investigate DNA hypermethylation of human 8-hydroxyguanine glycosy-lase(hOGG1 )gene and and the level of oxidative stress and DNA oxidative damage relations with arse-nic poisoning.METHODS In ende mic coal-pollution-borne arsenism area,Xinren county,Guizhou Province,according to the diagnostic criteria of ende mic arsenism(WS /T21 1 -2001 ),207 people with ende mic arsenism were selected and divided into four groups(The arsenic exposure group:46 cases, mild arsenism group:46 cases,moderate arsenism group:60 cases and severe arsenism group:55 cases).64 residents were selected as controls in a village about 12 km away fro m the ende mic arsenism area.With the informed consent principle,peripheral blood of all respondents was collected in order to analyze DNA methylation.Methylation-specific poly merase chain reaction were respectively performed to analyze hOGG1 Hypermethylation in arsenism respondents.Che mical methods were performed on the activity of super oxide dis mutase (SOD)and glutathione peroxidase (GSH-Px),while the contents of malondialdehyde (MDA)in the blood of patients were measured,and the contents of 8-hydroxy-2′-deox-yguanine(8-OHdG)urine of patients were measured and analysed.On the basis of methylation status are divided into hOGG1 gene methylation group (34 cases)and hOGG1 gene no methylation group (237cases).Analysis was performd on hOGG1 gene DNA methylation and the relationship between oxi-dative stress and arsenic poisoning.RESULTS The positive rates of hypermethylation of hOGG1 were associated with the degree of arsenic poisonin (co mpared with control group,χ2 =23.916,P <0.05, Co mpared with the Ende mic area normal group,χ2 =12.039,P <0.05 ).Co mparing with negative group,SOD〔(85 ±25)kU·L -1 〕,GSH-Px〔(70 ±26)kU·L -1 〕activity and 8-OHdG 〔(22.5 ±6.8)μg·L -1 〕contents were lower〔(1 18 ±41 )kU·L -1 ,(171 ±56)kU·L -1 ,(28.4 ±6.5)μg·L -1 ,P <0.05)〕in positive group.There was no significant difference between the MDA content(P>0.05).CONCLUSION Coal arsenic exposure can cause hOGG1 gene high methylation and oxidation and anti-oxidation system imbalance,causing DNA oxidative damage,it is one of the reasons to pro mote the develop ment of arsenic poisoning occurred.

Objective To investigate the effects of hyperbaric oxygen(HBO)on the expression of MMP-9 and MMP-2 mRNA in the brain tissues after cerebral ischemia and reperfusion,and the permeability of blood brain barrier(BBB).Methods Using cerebral ischemia-reperfusion models with conscious mice,0.25 MPa(atmosphaera absolutus,ATA)HBO was applied 5 times during the reperfusion period,and 2%Evan's blue(EB)was injected into the tail vein 1 hour before the animals were sacrificed.The expression of MMP-9 and MMP-2 mRNA and EB content were determined by RT-PCR and spectrophotometry.Results The expression of MMP-9 and MMP-2 mRNA aswell as EB content significantly increased in the ischemia-reperfusion group as compared with a sham surgery group.The expression of MMP-9 and MMP-2 mRNA,and EB levels in the HBO group were similar to those in the sham surgery group.The expression of MMP-9 and MMP-2 mRNA and EB levels in the group given HBO plus reperfusion group were significantly decreased as compared with those in the group receiving reperfusion alone. Conclusion HBO can significandy reduce the expression of MMP-9 and MMP-2 mRNA and the permeability of the BBB.