AIM To observe the therapeutic effect of colloidal bismuth tartrate in an animal colitis model.METHODS Immune-complex colitis was induced in groups of rabbits by formalin, and two hours later0.85 mL heat-aggregated rabbit IgG was given intravenously through the ear cannula. Animals wereintracolonically treated with colloidal bismuth tartrate (BITNAL), and its effect was compared withsulfasalazine (SASP), indomethacin (IND) and bifidobiogen (BIFG). Animals were killed, the mucosalappearance was scored (0-4), and tissue saved for histological studies, the number of neutrophils present ininflamed colonic tissue was quantitated by the myeloperoxidase (MPO) activity assay, the production oflipoxygenase and cyclo-oxygenase products was monitored and eicosanoid production were assayed byincubation colonic specimens and the media for prostaglandin E2(PGE2), leukotriene (LTB4), thromboxaneB2(TXPe) were examined by radiommunoassay.RESULTS Immune-complex colitis was induced by formalin and IgG, colonic damage persisted for at least1 wk by macrography. Histologically, the inflammatory response included mucosal and submucosalinfiltration by polymorphonuclear leukocytes, macrophages, lymphocytes and fibroblasts, the macroscopic,persent 2 wk after IgG, was correlated with greatly increased PGE2, LTB4 and TXB2 compared with levels incontrols. Treatment with BITNAL (500 mg/kg) resulted in a lowered inflammation index, lowered MPOactivity and inhibited the increased formation of PGF-2, LTB4 and TXB2 by the inflamed colon, and IND(500 mg/kg) markedly inhibited prostanoid formation in both inflamed and control colon but did not reducetissue damage, SASP (500 mg/kg) also inhibited the formation of PGE2, LTB4 and TXB2 but the effectswere less marked. BIFG (400 mg/kg) did not significantly reduce the colonic injury and the media sythesizedby the rabbit colon.CONCLUSION BITAL provides better therapeutic effects in experimental colitis than anti-inflammatorydrug IND or SASP.

AIM To study the effect of sclerotic complex agents (SCA) on the gallbladder wall of hybrid rabbits, andits therapeutic effect in hepatic cysts.METHODS The SCA containing tetracycline and dexamethasone was injected into the gallbladder of rabbitsto compare its action with those of normal saline and absolute ethylalcohol on the gallbladder wall. Thetherapeutic effects of SCA and absolute ethylalcohol on hepatic cysts were observed.RESULTS Abnormal changes were not found in the tissue cells of gallbladder in normal saline group. Butin absolute ethylalcohol group, a large amount of oozing fluid and blood appeared, the absorption processwas slow, and the fibrous tissue proliferated scarcely. In SCA group, there was less oozing fluid, no blood inthe gallbladder, and the absorption was active and the fibrous tissues grow obviously. In clinical practice,SCA possesses much advantage in the treatment of hepatic cysts, by which the cysts closed promptly, theexudation reduced from early stimulation, and no relapse occurred. The cure rates at the third, sixth,twelfth and twenty-fourth month were 65.1%, 96.2%, 98.1%, and 99.1% respectively; while in thecontrol group were 10.8%, 36.0%, 67.6% and 88.3% respectively. The difference was significant(P<0.01, <0.01, <0.01, <0.05). After the observation for 24 months, no relapse occurred in the SCAgroup, but 7 (6.3%) cases relapsed in control group (P<0.05).CONCLUSION The sclerotic agents should be used in sequence, i. e., a high concentration wasadministered to reduce and destroy the epithelium of the cysts, and to promote fiber tissue adhesion and thenthe remaining drug was used to stimulate epithelium to absorb the exudation. This combined regimen wasproved to be an ideal and effective method for treating hepatic cysts clinically.

The use of laser energy to weld biological tissues and produce sutureless anastomosis has its advantages over conventional silk-sutured anastomosis since it was reported in small vessels[1] and fallopian tubes[2], in the late 1970s. Since then, more investigators have welded a larger variety of tissues[3-13] and have expanded its application to welding trials of entertomies of rabbit and rat small intestine[14-17] Sauer et al[18] reported results from Nd: YAG laser in reconstruction of end-to-end welding in rabbit small intestine. Recently, controlled temperature during YAG and argon laser-assisted welding of entertomies of rabbit and rat was implemented to eliminate exponential increases in the rate of denaturation associated with rapidly increasing temperature[19，20]. Yet there was no report of sutureless end-to-end bowel anastomosis using low-power CO2 laser. This is a report of a circumferential end-to-end laser welding bowel anastomosis in rabbit by using 3 different CO2 laser powers to explore the feasibility of CO2 laser welding of a circumferential intestinal tissue and to determine the optimal laser-welding parameter. Then the appropriate CO2 laser power was chosen to weld bowels in rabbit and its long-term healing effect was evaluated.

Objective　To investigate whether the osteocyte apoptosis exists in orbital bones and to discuss its effect on the orbital development.Methods　Seven young Newzealand white rabbits were selected as experimental animals.At two-month-old ,all rabbits were killed and then zygomas were made into paraffin and electron microscope sections after they were decalcified.Apoptosis of osteocytes was observed by light microscope and transmission electron microscopes and detected by TUNEL staining.Results　The classical apoptosis of osteocytes was found under light and transmission electron microscopes.Apoptosis of osteocytes was diffused irregularly in the zygomatic tissue.　Conclusion　Osteocyte can apoptosis and it may participate in the development of the bony orbit.

Objective:TO explore the effectiveness of splenic tissue autotransplantation in restoring host defense. Methods: Rabbits were divided into three groups,Sham Operation(SO), Splenic Autotransplantation(SA)and Total Splenectomy(TS), and dynamic changes in histology and immunology were observed for over 24 weeks. Results: Histologic study shows that the white pulps were poorly developed and central arterioles disappeared in the regenerated splenic tissue. The weight of regenerated spleens recovered six months later in SA was 11% of that in SO, and was significantly reduced comparing with the implanted weight( P ＜0.05). Tere were no significant difference in the number of T lymphocytes and the levels of serum lysozyme among the three groups. A poor antibody response by the rabbits of SA and TS as compared to those of SO was noted after the primary intravenous administration with sheep red blood cells. After the challenge with type 3 pneumococci intravenously, pneumococcal clearance from bloodstream in SA did not differ significantly from that in TS,but was marKedly delayed compared with that in SO(P＜0.01). Conclusion: The results indicate that the low quantity and poor quality of the regenerated spleens may contribute to the inferior immunoprotective ability of 1/3 splenic autotransplantation. Therefore, it implies that the regenerated spleens can not fully compensate the original one in im-munology, especially, host resistance to infection.

高压氧预处理诱导兔脊髓缺血耐受现象产生

INTRODUCTION Paraplegia is a severe complication of desendingthoracic aneurysm (TA) and thora coabdominal anerysm(TAA) repair[1]. This complication is caused by spin al cord ischemia secondary to aortic clamping. Many methods and drugs have been suggeste d to protect against ischemic spinal cord injury[2-4] but the efficacy is still under dispute. Therefore, it is necessary to find some effective methods or dru gs to effectively protect against spinal cord ischemic injury.

咪唑啉/α2受体激动剂对兔窦房结起博细胞的电生理效应

AIM: To compare the effects of moxonidine (Mox), clonidine (Clo), agmatine (Agm), and xylazine (Xyl) on action potentials (AP) of the rabbit sinoatrial node (SAN) pacemaker cells and investigate the contribution of α-adrenoceptors to the cardiac electrophysiologic responses induced by the agonists. METHODS: Intracellular microelectrode technique was used to record AP in the rabbit SAN pacemaker cells. Vasoconstrictive responses to norepinephrine (NE), Mox, Clo, Agm and Xyl were observed in the thoracic aorta and ear vein isolated from rabbits. RESULTS: (1) In the rabbit thoracic aorta, a rank order of potency producing vasoconstrictive responses was NE＞Clo＞Mox;and a rank order of potency in ear vein was Clo＞NE＞Xyl=Mox. Agm did not produce any vascular responses in both preparations, and Xyl did not produce vascular responses in the thoracic aorta. (2) Mox, Clo, Xyl, and Agm concentration-dependently decreased the rate of pacemaker firing (RPF), and prolonged APD50 and APD90 in the rabbit SAN pacemaker cells. The rank order of decreasing RPF or prolonging APD was Clo＞Xyl=Mox. (3) Most effects of Clo were partially inhibited by yohimbine, but those of Xyl and all the effects of Agm on the AP in SAN pacemaker cells were not affected by the treatment with yohimbine. (4) In the presence of propranolol 1 μmol/L, phenylephrine did not cause any effects on AP in the rabbit SAN pacemaker cells. CONCLUSION: Like Mox, Clo changes AP of the rabbit SAN pacemaker cells via α2-adrenoceptors partially, but the effects of Xyl and Agm on the AP are almost not related to α2-adrenoceptors. Moreover, there are no obviously functional α1-adrenoceptors in the rabbit SAN pacemaker cells.