Objective Cerebral artery vasospasm is a major cause of death and disability in patients experiencing subarachnoid hemorrhage (SAH). Vasospasm typically has been evaluated using angiography to examine narrowing of large diameter (>1 mm) cerebral arteries. Currently, little is known regarding the impact of SAH on small diameter (100～200 μm) cerebral arteries, which play an important role in the autoregulation of cerebral blood flow. The goal of the current study was to examine the influence of SAH on the pressure-diameter relationship of these small diameter blood vessels. Methods Small diameter cerebral arteries were obtained from a rabbit SAH model. Isolated artery segments were canulated and placed in a myograph chamber superfused with warmed, oxygenated, physiological saline solution. Diameter measurements were then recorded to step-wise increases in intravascular pressure. Results Cerebral arteries from SAH animals exhibited a significant increase in pressure-induced constrictions (myogenic tone) at intravascular pressures between 40 mmHg and 120 mmHg. At intravascular pressures above 120 mmHg, myogenic tone began to decrease and was abolished at pressures above 180 mmHg. Conclusion These data suggest that in the days following SAH, myogenic tone is enhanced in small diameter cerebral arteries subjected to physiological levels of intravascular pressure. However, supra-physiological intravascular pressures causes vasodilation, suggesting small diameter cerebral arteries may act as therapeutic targets of hypervolemia, hemodilution, and hypertension "Triple H therapy" used in the treatment of cerebral artery vasospasm.

Objective　To explore the risk factors and indications for perioperative tracheostomy in patients with myasthenia gravis. Methods　A total of 174 patients with myasthenia gravis undergoing thymectomy were reviewed retrospectively between April 1980 and August 1999. Perioperative tracheostomy was performed on 44(25.3%) cases. Myasthenic or cholinergic crisis happened in 38 cases (21.8%). The relationship of the crisis incidence and Osserman classification, state of illness, present of thymoma, preoperative pulmoary function and the dose of anticholinergic agents given preoperatively were analyzed. At the same time the indications of perioperative tracheostomy were discussed. Results　The highest incidence of myasthenic or cholinergic crisis and perioperative tracheostomy were found in cases with long history of the disease, high dose of anticholinergic agents administration, Osserman classification over stageⅡb, with infiltrated thymoma, and preoperative pulmoary function impairment. Conclusion Perioperative tracheostomy and artificial ventilation are most important approaches when myasthenic or cholinergic crisis after thymectomy appeared. But the indications for postoperative prophylactic tracheostomy and artificial ventilation must be strictly selected.

Objective　To investigate whether matrix metalloproteinase-9 (MMP-9) was synthesized in pregnant cervix during parturition and its source and distribution. Methods　Cervical species (n=10, each weighing about 0.3 g) were taken from pregnant women immediately after delivery. Other cervical species (n=7) were served as negative control from those non-pregnant women but undergoing uterotomy due to other benign diseases. Immunohistochemical method (ABC) was carried out to detect the expression of MMP-9, with a monoclonal antibody against MMP-9. Results　Positive staining of MMP-9 was found in the cytoplasm of polymorphonuclear leukocytes (PMN) that had infiltrated into cervix or located in blood vessels of cervix. Scattered light positive staining were found in some interstitial cells of the cervix. No other cells including fibrocytes and lymphocytes were positive to MMP-9. No positive staining was found in control tissues. Conclusion　There are strong expressions of MMP-9 in pregnant cervix in term labor, derived mainly from infiltrated PMN. MMP-9 may be an important regulator in the process of cervical ripening.

Objective　To prepare monoclonal antibody (McAb) pool against Bacteroides fragilis and Clostridium perfringens and evaluated its effect in rapid diagnosis in surgical infection. Methods　After the preparation of monoclonal antibodies against B. fragilis and C. perfringens, 191 specimens collected from infectious patients was detected with indirect immunofluorescent antibody (IFA) and enzyme labeled antibody (ELA). The results were compared with routine cultural method (CM). Results　Among the 191 specimens, 53 (27.7%), 55 (28.8%) and 25 (13.1%)strains of B. fragilis were detected with IFA, ELA and CM respectively, and for C.perfringens, 12(6.3%), 11(5.8%), and 6(3.1%) strains were found. The detectable rate of anaerobic bacteria by IFA and ELA was higher than by CM, but no difference was found between these 2. Conclusion　The self-made McAb pool against B.fagilis and C.perfringens might be a rapid, specific, sensitive and simple McAb pool for detecting B.fragilis in surgical infection and C.perfringens in wartime.

Objective　To investigate the relationship between allergic reaction and fungus sensitinogen in patients with chronic colitis. Methods　Skin test with 3 groups of fungus allergen (6 types), eosinophil detection in serum and intestinal secretion and serum specific IgE (SIgE) test were tested in 246 patients with chronic colitis. The other 61 patients with chronic diarrhea were served as control. Results　Fungus positive was found in 110 patients (43.09%) in dermal fungus allergen test, but only 8.20% in control (P<0.01). In patients with chronic colitis, the positive rates of eosinophil in intestinal secretion and specific IgE induced by fungus allergen were 29.35% and 41.60% respectively. Conclusion　It is indicated that some patients with chronic colitis have correlation with allergic reaction of digestive system induced by food with fungus allergen.

Objective　To study the effects of measures for preventing early postburn damage in improving survival rate of burn patients during the third stage. Methods　12 568 burn cases admitted to our institute were chronically divided into three groups (1958-1980;1981-1990;1991-2000). Total burn surface area (TBSA), survival rate, incidence of burn shock, systemic infection and organ damage as well as the main treatments adopted in the recent decade were retrospectively analyzed. Results　Incidence of burn shock, systemic infection and organ damage were significantly lower, and the total survival rate and the survival rate in patients with different TBSA were markedly higher in the third group as compared with those in the first and the second group. Incidence of organ damage in patients treated with delayed fast fluid infusion, early escharectomy en masse, early enteral feeding, early prevention of inhalation injury and gut bacterial translocation were also significantly lower than in the control. Conclusion Measures taken in the third group for preventing early postburn damage play an important role in improving the survival rate of burn patients.

Objective　To investigate the protective effect of calcium antagonist Verapamil (VP) on kidney preservation in HCA solution. Methods　After kidneys were isolated from rabbits, they were perfused and stored in HCA solution or in HCA solution with VP pre-supplement at 4℃ for 24 h respectively. The contents of mitochondrial calcium in renal cells and ATP in renal tissues were measured in every group. Results　The contents of mitochondrial calcium was remarkably higher and ATP significantly lower in the kidneys in HCA solution at 4℃ for 24 h than those just after resection. But these could be inhibited in those storing in the HCA solution with VP pre-supplement. Conclusion　Calcium antagonist VP can protect kidney function during HCA solution preservation by inhibiting calcium intaking into mitochondrium.

Objective　To observe the effects of epithelial growth factor (EGF) and basic fibroblast growth factor (bFGF) on wound healing of the penetration keratoplasty (PKP) with autograft in rabbits. Methods　After the establishment of penetrating keratic autograft model on 24 rabbits, they were equally divided into EGF-, bFGF-, EGF+bFGF-treated and control groups. The wound healing of all the animals were observed with healing intensity, liquid scintillation counter, AgNORs staining, VG staining and transmission electron microscopy. Results　①EGF, bFGF, and EGF+bFGF increased the limiting pressure of the wounds and the 3H-TdR incorporation. ②The fibroblast cells and its secreting proliferative collagen in both the bFGF group and EGF+bFGF group were more well-arranged. Conclusion　①EGF, bFGF, EGF+bFGF can obviously elevate the intensity of wound healing after PKP and enhance the synthesis of DNA. ②The effect of this agent combination is just as the same as bFGF applied alone 14 d after the operation. ③bFGF can improve the quality of wound healing after PKP.

Objective　To explore the effect of photon on blood biologic components in blood photochemical treatment. Methods　After the blood sample was adjusted to an appropriate density, it was treated with 0.1 nmol/ml 8-MOP (8-methoxypsoralen), 0.1 nmol/ml TFO (triple helix-forming oligonuletide) and UVA (ultraviolet A radiation) at the intensity of 1 800 μW/cm2 for 3～20 min. The changes of biologic activities of major components in blood were measured with automatic blood gas analyzer, platelet aggregation analyzer, blood coagulation analyzer, micropipette aspiration system and assay of poly-lysine adsorption. Results　The oxygen content in blood was increased gradually. The resilience of erythrocyte was enhanced ，but its adhesiveness was decreased. The parameters related to blood coagulation had some changes but all remained within the normal ranges. Conclusion　Under the definite condition of blood virus being inactivated effectively, the nonspecific effect of photosensitive response may improve blood oxygen content, enhance the transfiguring ability of erythrocyte and decrease the blood viscosity, but having no obvious change on blood coagulation.

Objective　To study the similarities and differences on in vitro replication and expression of hepatitis C virus (HCV) between human fetal hepatocytes (HFH) and 7721 cell line. Methods　Human fetal hepatocytes and a hepatoma cell line 7721 were incubated with a serum from hepatitis C patient. After incubation, the presence of HCV RNA, the expression of HCV NS3 antigens in cells and/or supernatant were examined by RT-PCR, in situ hybridization and immunohistochemistry, respectively. Results　It was found that: ①The intracellular HCV RNA was first detected on d 2～3 post-incubation and then could be intermittently detected in cells and/or supernatant subsequently (HCV RNA could be detected in 7721 cells during a period of at least 66 days. In HFH, HCV RNA could be detected up to 25 days after incubation); ②HCV-NS3 antigen could be expressed in infected cells; ③Minus-strand RNA of HCV was mainly located within cytoplasm by in situ hybridization. Conclusion　The results suggest that both the fetal hpatocytes and the hepatoma cell line 7721 are susceptible to HCV, and especially 7721 cell line can stably support HCV replication in vitro and may be used as the target cell for long-term cultures of HCV.