α硫辛酸通过激活AMP活化的蛋白激酶防止肥胖大鼠内皮功能障碍

血管内皮细胞脂质蓄积在肥胖者动脉粥样硬化的发病机理中起重要作用。我们以前的研究发现,α硫辛酸能激活AMP活化的蛋白激酶,减少肥胖大鼠骨骼肌细胞中脂质蓄积。为了观察α硫辛酸是否通过激活内皮细胞AMP活化的蛋白激酶来改善内皮功能障碍。我们用肥胖大鼠和对照大鼠做实验,观察给予α硫辛酸前后这两组大鼠的内皮依赖性血管舒张功能和内皮细胞凋亡情况。结果发现,肥胖大鼠的内皮依赖性血管舒张功能受损程度和主动脉内皮细胞凋亡数都较对照组高;甘油三酯和脂过氧化物水平也较对照组高,而一氧化氮复合物较对照组低。给予α硫辛酸后,肥胖大…     

Laparoscopic treatment of recurrent small bowel obstruction secondary to ileal endometriosis

Endometriosis is a relatively common condition characterized by implantation and proliferation of endometrial glands outside the uterus affecting 8% to 15% of women. Intestinal involvement is common, reported in 12% to 37% of individuals with the disease. The sites most often affected are the sigmoid colon and rectum (85%), while small bowel involvement is seen less frequently (7%) and usually confined to the distal ileum. The cecum (3.6%) and appendix (3%) are the sites least affected.     

Mechano-active scaffold design of small-diameter artificial graft made of electrospun segmented polyurethane fabrics

To fabricate a "mechano-active" tubular scaffold of nonwoven mesh-type small-diameter artificial graft made of the synthetic durable elastomer, segmented polyurethane, the fabrication technique of electrospinning on a mandrel under a high rotation speed and transverse movement was used. Emphasis was placed on how the rotation speed of the mandrel and the fusion or welding states of fibers at contact points affect the compliance (ease of intraluminal pressure-dependent circumferential inflation) and Young's modulus determined by uniaxial stretching in the longitudinal and circumferential directions. The results showed that a high rotation speed is attributed to exhibit isotropic mechanical properties in the entire range of applied strain but reduces the compliance, and a high fusion state, which is produced using a mixed solvent with a high content of high-boiling-point solvent, reduces the compliance but is expected to exhibit high durability in a continuously loaded pulsatile stress field in an arterial circulatory system.     

Collagen-induced arthritis in C57BL/6 (H-2b) mice: new insights into an important disease model of rheumatoid arthritis

Collagen-induced arthritis (CIA) is a widely used model of rheumatoid arthritis (RA) and has been important for understanding autoimmunity. CIA is purportedly restricted to mice bearing the MHC class II H-2q or H-2r haplotypes. In this study, we re-examined established concepts regarding susceptibility to CIA. We found mice derived from the C57BU6 (B6) (H-2b) background can develop CIA with high incidence (60-70%), and sustained severity by using an immunization procedure modified for optimum response in DBA/1 (D1) (H-2q) mice. Clinically and histologically the B6 disease resembles that of D1 mice and is dependent on immunization with type II collagen, as well as on B and CD4+ T cells. In contrast, 129/Sv mice, which share H-2b, are resistant to CIA. We conclude that susceptibility to CIA may reflect immunization conditions and/or important contributions from non-MHC genes, revealed by different immunization protocols. A practical outcome is that CIA can be directly applied to gene knockout mice generated from B6 embryonic stem cells without need for backcross onto the D1 background. This model may lead to improved understanding of autoimmunity in CIA and RA and may provide a platform for analysis of the contribution of non-MHC genes to CIA.     

Blood oxygen transport and pro-oxidant-antioxidant state during liver reperfusion

Indices of blood oxygen transport (hemoglobin-oxygen affinity, pCO2, pH, pO2, etc.) and prooxidant-antioxidant state (Schiff bases, conjugated dienes, catalase, retinal, alpha-tocopherol) were measured in rabbit blood and the liver during postischemic reperfusion. Hepatic ischemia was induced for 30 min by ligation of a hepatica propria, and reperfusion lasted for 120 min. Hepatic ischemia worsened blood oxygen transport. Restoration of arterial blood flow did not result in improvement of oxygen delivery. Moreover, marked metabolic acidosis was observed throughout 2 hr of reperfusion. Ischemia induced a shift of oxyhemoglobin dissociation curve to the right. This shift persisted after restoration of hepatic arterial blood flow facilitating increased oxygen transport to tissues. Changes in blood oxygen transport during hepatic ischemia/reperfusion were accompanied with high activity of free radical processes. During reperfusion, the largest increase in content of lipid peroxidation products and the greatest fall of some antioxidant levels except catalase were observed indicating impairment of liver prooxidant-antioxidant balance. The results showed that activation of lipid peroxidation and a decrease in some antioxidant levels during hepatic reperfusion were associated with lowering of hemoglobin-oxygen affinity and suggest participation of the latter in impairment of prooxidant-antioxidant balance.     

Enhanced responsiveness of human extravisual areas to photic stimulation in patients with severely reduced vision

Lesions in the primary visual cortex induce severe loss of visual perception. Depending on the size of the lesion, the visual field might be affected by small scotomas, hemianopia, or complete loss of vision (cortical blindness). In many cases, the whole visual field of the patient is affected by the lesion, but diffuse light-dark discrimination remains (residual rudimentary vision, RRV). In other cases, a sparing of a few degrees can be found (severely reduced vision, SRV).In a follow-up study, we mapped visually induced cerebral activation of three subjects with SRV using functional magnetic resonance imaging. We were especially interested in the visual areas that would be activated if subjects could perceive the stimulus consciously although information flow from V1 to higher visual areas was strongly reduced or virtually absent. Because subjects were only able to discriminate strong light from darkness, we used goggles flashing intense red light at a frequency of 3 Hz for full visual field stimulation. Besides reduced activation in V1, we found activation in the parietal cortex, the frontal eye fields (FEF), and the supplementary eye fields (SEF). In all patients, FEF activation was pronounced in the right hemisphere. These patterns were never seen in healthy volunteers. In a patient who recovered completely, we observed that extrastriate activation disappeared in parallel with the visual field restitution. This result suggests that damage to the primary visual cortex changes the responsiveness of parietal and extravisual frontal areas in patients with SRV. This unexpected result might be explained by increased stimulus-related activation of attention-related networks.     

Implantation of bone marrow mononuclear cells using injectable fibrin matrix enhances neovascularization in infarcted myocardium

Neovascularization may improve cardiac function and prevent further scar tissue formation in infarcted myocardium. A number of studies have demonstrated that bone marrow-derived cells have the potential to induce neovascularization in ischemic tissues. In this study, we hypothesized that implantation of bone marrow mononuclear cells (BMMNCs) using injectable fibrin matrix further enhances neovascularization in infarcted myocardium compared to BMMNC implantation without matrix. To test this hypothesis, infarction was induced in rat myocardium by cryoinjury. Three weeks later, rat BMMNCs were mixed with fibrin matrix and injected into the infarcted myocardium. Injection of either BMMNCs or medium alone into infarcted myocardium served as controls. Eight weeks after the treatments, histological analyses indicated that implantation of BMMNCs using fibrin matrix resulted in more extensive tissue regeneration in the infarcted myocardium compared to BMMNC implantation without matrix. Examination with fluorescence microscopy revealed that cells labeled with a fluorescent dye prior to implantation survived in the infarcted myocardium at 8 weeks of implantation. Importantly, implantation of BMMNCs using fibrin matrix resulted in much more extensive neovascularization in infarcted myocardium than BMMNC implantation without matrix. The microvessel density in infarcted myocardium was significantly higher (p < 0.05) when BMMNCs were implanted using fibrin matrix (350 +/- 22 microvessels/mm2) compared to BMMNC implantation without matrix (262 +/- 13 microvessels/mm2) and medium injection (76 +/- 9 microvessels/mm2). In addition, average internal diameter of microvessels was significantly larger (p < 0.05) in BMMNC implantation with fibrin matrix group (14.6 +/- 1.2 microm) than BMMNC implantation without matrix group (10.2 +/- 0.7 microm) and medium injection group (7.3 +/- 0.5 microm). These results suggest that fibrin matrix could serve as a cell implantation matrix that enhances neovascularization efficacy for myocardial infarction treatment.     

Galactosylated chitosan as a synthetic extracellular matrix for hepatocytes attachment

Galactose moiety as the hepatocyte anchorage was covalently coupled with chitosan for the development of synthetic extracellular matrix. Hepatocytes adhesion to galactosylated chitosan (GC)-coated polystyrene (PS) dish became as high as 94.7% after 2 h incubation whereas the hepatocytes adhesion to chitosan-coated PS dish was 69.1%, indication of galactose-specific recognition between GC molecules and asialoglycoprotein receptors of hepatocytes. The DNA synthesis of the hepatocytes adhered to GC-coated dish was increased in the presence of epidermal growth factor (EGF) at low concentration of GC (0.05 microg/ml) whereas the DNA synthesis of the hepatocytes adhered to GC-coated dish was decreased in the presence of EGF at high concentration of GC (5 microg/ml). The spreading shapes of the hepatocytes adhered to the surface in the presence of EGF at low concentration of GC (0.05 microg/ml) were enhanced than in the absence of EGF. The hepatocytes adhered to the surface at high concentration of GC (5 microg/ml) showed round shapes and exhibited many spheroid formation after 24 h in the presence of EGF.