AIM: To study the effect of cilazapril on pulmonary vascular endothelial dysfunction in hypoxic rats. METHODS: The structure and function of endothelium in hypoxic rats were studied by biochemical analysis, radioimmunoassay, transmission electron microscope and correlated with hemodynamic. RESULTS: 1) The change and damage of ultrastructure in endothelial cell (EC) were obsevered in hypoxic rats. 2) The contents of plasma nitric oxide (NO) and superoxide dismutase (SOD) activity in blood as well as endothelial nitric oxide synthase (eNOS) activity in the lung tissue were significantly lower in the hypoxic rat than those in contral animals. The concentrations of plasma endothelin-1(ET-1) and angiotensin converting enzyme(ACE) as well as malondialdehyde(MDA) were significantly higher in the hypoxic rat than these in contral animals. The relaxing and contracting factors had a significant positive/negative correlation with mean pulmonary artery pressure (mPAP). 3) Cilazapril significantly decreased the level of ET-1 and ACE and significantly increased the level of NO and activity of eNOS and SOD. At the same time, cilazapril extenuated hypoxia-induced injuries of EC. CONCLUSION: The results indicate that damaging structure and dysfunction of EC existes in hypoxic rats. The cilazapril effectively preventes and treates the chronic hypoxic PH by relieving the injury and improving secretion in EC.

BACKGROUND: There are some studies proposing cell membrane may be one of target cell regions for electromagnetic biological effects. However, reports responsible for cellular membrane permeability and cellular biological effects after electromagnetic irradiation are few. OBJECTIVE: This study was designed to investigate the correlations of low-power millimeter wave irradiation to cellular membrane permeability and apoptosis of HL60.DESIGN: Controlled experiment.SETTING: Thus study was performed at the Medical Experimental Central Laboratory, Guangzhou General Hospital,Guangzhou Military Area Command of Chinese PLA between November 2006 and April 2007. MATERIALS: The human leukemic cell lines HL60 were kindly provided by Medical Experimental Center of Guangzhou Military Area Command of Chinese PLA and HD-413.2HPSG 100 millimeter wave irradiation generator was developed by Xi'an Hengda Microwave Technology Development Company, China. METHODS: HL60 cells were irradiated by millimeter wave at frequency of 41.32 GHz and mean power density of 2 mW/cm2, and divided into five groups according to the irradiation time (0, 15, 30, 45, 60 minutes groups).MAIN OUTCOME MEASURES: Lanthanum tracing was used to observe intracellular and extracellular lanthanum particles distribution and evaluate the change of cellular membrane permeability; ultrastructure and morphological characteristics of HL60 cells were observed through an transmission electron microscope; Quantitative analysis of apoptotic cells was performed by in situ marking method. RESULTS: In the 45 and 60 minutes groups, a small amount of lanthanum particles in the cytoplasm, swollen mitochondria, expanded rough endoplasmic reticulum, and obvious apoptosis were detected by ultrastructure observation. TUNEL staining showed, compared with the 0 minute control group, the apoptosis rate showed a trend of elevation in all the irradiation groups, particularly in the 45 and 60 minutes groups. CONCLUSION: Low-power millimeter wave irradiation on HL60 cells can lead to an increase in cellular membrane permeability of HL60, which may be one of the primary causes for promoting apoptosis and producing other biological effects.

Objective To explore the roles of humoral immunity in severe acute respiratory syndrome (SARS). Methods The pathological changes in the SARS autopsy case and a case of lung puncture were observed by light microscopy and electron microscopy. The autoantibody and immune complexes in the sample tissues were detected by immunohistochemical staining and histochemical staining. Results There were severely diffusive damages in the lungs. The endothelial cells in blood were injured. Fibrinoid necroses of blood vessels were observed in several organs and injury of immune organs and massive autoantibody and immune complexes were found in pathologically changed tissues. Electron dense deposits were observed in the basement membrane of blood vessels and mesangial matrix of glomerulus by electron microscopy. Conclusion The SARS viruses not only cause direct damages to the tissues but also lead to immune complex mediated hypersensitivity which in turn gives rise to a large number of tissue lesions. This indicates that the humoral immunity plays an important role in the process of organ damages.

Objective To investigate the relationship between the expression of ING4 and clinical primary breast cancer.Methods Tissue and peripheral blood samples of primary breast cancer patients were collected and the expression levels of ING4 and NF-κB in tissue samples were detected with immunohistochemistry.The expression of ING4 in the peripheral blood was detected with ELISA.Results The positive rates of expression of ING4 and NF-κB in breast cancer tissues were 100.00 ％ (30/30),which were significantly higher than that in the adjacent tissues 12.50 ％ (3/24) and 93.75 ％ (45/48) compared to 6.67 ％ (1/15) respectively.Compared with the preoperative,the ING4 level in peripheral blood from the postoperative breast cancer patients was significantly reduced (P =0.044).Conclusions The expression of ING4 does not decrease in the primary breast cancer patients.The increasing is perhaps due to the body's stress response against tumor development in early stage by secreting more ING4 protein.

Objective To observe the parameters and effect of endocardial pacing by steel wire electrode cardiac puncture on heart with normal beat in living animal, and evaluate its safety.Methods After anaesthesia and thoracotomy in 6 living dogs with normal heart beat, the pericardia were excised. Steel wire electrodes with annular or hook tips were used respectively at right ventricular 4 corresponding spots to perform cardiac puncture endocardiac pacing (each dog experienced 8 times of puncture); the time from puncture to effective pacing, pacing parameter and puncture complication (time and quantity of bleeding) of each electrode at each spot were recorded. Finally, the two types of electrode completed 24 times of manipulation respectively; the data collected of the two types were compared. Results The cardiac pacing successful rates in the two groups were 100%; the time taken from the beginning of heart puncture to effective pacing in annular tip group was less than that in hook tip group, but the time difference between the two groups showed no statistical significance (s: 18.4±2.3 vs. 19.6±4.1,P > 0.05). The parameters of pacing in the annular tip group, such as operation time (s: 18.4±2.3 vs. 19.6±4.1), the threshold value of pacing (V: 2.1±0.2 vs. 2.2±0.8), the amplitude of R wave sensed (mV: 11.3±3.2 vs. 12.6±4.1) and the impedance of electrode (Ω: 674.2±89.7 vs. 668.5±101.3) were not significantly different compared with those in the hook tip group (allP > 0.05). Either after puncture or after the electrodes were taken out, the time of bleeding [after puncture (minutes): 4.4±2.3 vs. 4.5±3.1, after the electrodes taken out (minutes): 4.1±2.2 vs. 4.8±2.5] and the volume of bleeding [after puncture (mL): 2.8±2.4 vs. 3.2±3.5, after the electrodes taken out (mL): 3.3±1.7 vs. 3.5±2.6] were not significantly different between the two groups (allP > 0.05).Conclusions In living dogs with normal heart beat, the manipulation and function of endocardiac pacing by cardiac puncture with either steel wire annular or hook tip electrode are well and effective, and the performance is simple and safe without any serious myocardial injury and complication. Thus, it is helpful to quickly establish efficient endocardiac pacing in emergency cases.

Aim To investigate the effect of magnetic nanoparticleencapsulated epirubicin(MNPE) on inducing apoptosis of human liverHep-6 tumor cell line in vitro and provide new method for local ablation ofliver in order to improve survival period of patients and quality oflife. Methods Inductive apoptosis of nano-magnetic pharmoparticle toHep-6 tumor cell of primonary hepatic cell caner was investigated by DNAelectrophoresis, electron nicroscopy , and flow cytometry analysis. Theseitems were divided into three groups, control, drug-control, and grouptreated with magnetic nauoparticle encapsulated epirubicin. The changes ofhuman liver Hep-6 apoptosis induced by magnetic nanoparticle encapsu-lated epirubicin were observed on different time-point and with differentnanoparticle encapsulated epirubicin and control group of biaoroubixingwere divided into high-dosage and low-dosage group. And the ultimateconcentration of 10 mg/L and 100 mg/L were given respectively on hu-group was iucreased from 25% to 54% after 24 hours. The apoptosis ratein the experimental group, biaoroubixing group and control group was78%, 53% and 2% respectively after 36 hours. There was significantdifference( t = 3.05. P ＜ 0.05) between the results of each group. Theapoptosis rate and quantity of medicine presented positive relativity withtime ( r = 0.96, P ＜ 0.05 ) .Conclusion Magnetic nanopartiele encap-sulated epirubicin presents the advantages of slow degradation, release ofmagnetic nanoparticle system and better target and can induce apoptosis ofliver tumor Hep cell.

OBJECTIVETo study the role of neuronal nitric oxide synthase (nNOS) in aged rats' hippocampal delayed neuronal death (DND) following brain ischemia.

METHODSModels of incomplete brain ischemia were induced by clipping common carotid artery. A total of 46 aged SD rats were divided into 8 groups: normal control group (Group A, n=5), sham-operation group (Group B, n=5), reperfusion 1, 6, 12, 24, 48, and 96 hours groups after brain ischemia for 30 minutes (Group C, D, E, F, G, and H, n=6/group). The expression of nNOS was examined by immunohistochemistry and neuronal ultrastructural changes were observed by the transmission electron microscopy (TEM) at different time points after reperfusion.

RESULTSImmunohistochemistry showed that nNOS expression in the hippocampal neurons was high in Group E, low expression in Group D, moderate expression in Group F and G. There was nearly no expression of nNOS in Group A, B, C, and H. Ultrastructure of hippocampal neurons was damaged more severely in reperfusion over 24 hours groups.

CONCLUSIONSNitric oxide (NO) may be one of the important factors in inducing DND after ischemia/reperfusion.

Animals ; Apoptosis ; Brain Ischemia ; enzymology ; Female ; Hippocampus ; enzymology ; pathology ; Immunohistochemistry ; Male ; Microscopy, Electron ; Neurons ; enzymology ; Nitric Oxide Synthase ; metabolism ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; enzymology

OBJECTIVE: To investigate if hyperbaric oxygen ( HBO) may induce structural changes of neurons in hippocampus from infantile rats and if the changes are reversible. METHODS: All 27 healthy SD infantile rats were exposed to HBO (0.25 MPa) or hyperbaric air (HBA) for 1 to 3 courses (10 days as 1 course). The hippocampus was taken at the end of each course to observe its morphology b y light microscope and electron microscope. RESULTS: HBO exposure induced capillary dilation, nuclear membr ane winding or blurring and some mitochondria swelling with its crista blurring i n neurons. The changes occurred after 1 course exposure and became significant w ith time. Most of the changes recovered 20 days after stopping exposure. No chan ge was found after HBA exposure. CONCLUSIONS: Long-term HBO exposure can cause capillary dilati on and ultrastructural injury of neurons in hippocampus from infantile rats. The damage is not serious, but reversible.

OBJECTIVETo investigate the dynamic changes of type I collagen, and the activity of metalloproteinases-1 (MMP-1) and tissue inhibitor of metalloproteinases-1 (TIMP-1) after angioplasty.

METHODSThe restenotic model of iliac arteries of domestic microswine was established with hypercholesterol feed plus two angioplasties. Angioplastied vessels were harvested at the end of 1, 2, 3 and 6 months after the second angioplasty. Immunohistochemistry, transmission electronic microscopy and image quantitative analysis techniques were employed to study neointimal proliferation, the phenotype of vascular smooth muscle cells (VSMC) and the expression of type I collagen, MMP-1 and TIMP-1.

RESULTSThe peak of vascular neointimal proliferation was at 3 months after angioplasty. The expression of type I collagen gradually increased from 1 to 6 months after angioplasty. For MMP-1, expression was lower in the early stage after angioplasty but increase to normal levels of control vessels at 6 months after angioplasty. Expression of TIMP-1 rapidly increased in the early phase after angioplasty, reached peak at 3 months and maintained the high level till 6 months after angioplasty. Meanwhile, the VSMC was predominantly the synthetic phenotype at the early stage and was transformed to the contractive phenotype at the late stage after angioplasty. The ratio of TIMP-1 and MMP-1 was positively related to the area of the neointima and the expression of type I collagen respectively (P < 0.01).

CONCLUSIONType I collagen increased gradually after angioplasty, which might be determined by the ratio of TIMP-1/MMP-1 and also related to the phenotype of VSMC.

Angioplasty ; Animals ; Arterial Occlusive Diseases ; metabolism ; surgery ; Collagen Type I ; metabolism ; Iliac Artery ; surgery ; Matrix Metalloproteinase 1 ; metabolism ; Muscle, Smooth, Vascular ; cytology ; metabolism ; Swine, Miniature ; Tissue Inhibitor of Metalloproteinase-1 ; metabolism

Objective To investigate the protective effect of dexamethasone on hearing loss induced by canalwall-down mastoidectomy.Methods A total of 76 patients (76 ears) were randomized to dexamethasone group and non dexamethasone group with 38 patients in each group.For dexamethasone group,gelfoam soaked with dexamethasone (5 mg/ml) was topically applied to the round window niche at the end of the surgery,and dexamethasone was administrated intravenously at the dosage of 5 mg/50 kg immediately after the surgery.While for non-dexamethasone group,dexamctbasone was not used.The pure-tone audiograms were performed before mastoidectomy and 90 days after the surgery.Absolute bearing change was defined as the difference in hearing thresholds in decibels before and after the surgery.Results The changes of bone conduction thresholds in dexamethasone group were 8.3± 3.9 dB at 6 kHz,11.3±5.2 dB at 8 kHz,and 10.1±7.2 dB for HPTA (4-6-8 kHz high tone average).As in non-dexamethasone group,the changes of bone conduction thresholds were 13.7±4.6 dB at 6 kHz,25.1±5.4 dB at 8 kHz,19.3±9.7 dB for HPTA.There were significant differences in the changes of bone conduction thresholds between dexamethasone and non dexamethasone groups at frequencies of 6 kHz (P=0.039),8 kHz (P=0.007) and HPTA (P=0.009).Conclusion The results demonstrated that application of dexamethasone significantly reduced sensorineural high frequencies (6 kHz and 8 kHz) hearing loss after canal-wall down mastoidectomy,thus the use of dexamethasone is recommended.