Interference of GSM mobile phones with communication between Cardiac Rhythm Management devices and programmers: A combined in vivo and in vitro study.

To investigate interference, and how to avoid it, by high-frequency electromagnetic fields (EMFs) of Global System for Mobile Communications (GSM) mobile phone with communication between cardiac rhythm management devices (CRMs) and programmers, a combined in vivo and in vitro testing was conducted. During in vivo testing, GSM mobile phones interfered with CRM-programmer communication in 33 of 65 subjects tested (50.8%). Losing ventricle sensing was representative in this study. In terms of clinical symptoms, only 4 subjects (0.6%) felt dizzy during testing. CRM-programmer communication recovered upon termination of mobile phone communication. During in vitro testing, electromagnetic interference by high-frequency (700-950 MHz) EMFs reproducibly occurred in duplicate testing in 18 of 20 CRMs (90%). During each interference, the pacing pulse signal on the programmer would suddenly disappear while the synchronous signal was normal on the amplifier-oscilloscope. Simulation analysis showed that interference by radiofrequency emitting devices with CRM-programmer communication may be attributed to factors including materials, excitation source distance, and implant depth. Results suggested that patients implanted with CRMs should not be restricted from using GSM mobile phones; however, CRMs should be kept away from high-frequency EMFs of GSM mobile phone during programming.

Effect of combined treatment with rosuvastatin and protein kinase Cß2 inhibitor on angiogenesis following myocardial infarction in diabetic rats.

The aim of the present study was to investigate the effects of combined treatment with rosuvastatin and LY333531, a selective protein kinase C (PKC)ß2 inhibitor, on angiogenesis under hyperglycemic conditions. Human umbilical vein endothelial cells (HUVECs) cultured in medium containing a normal or high concentration of glucose (33.3 mmol/l) were treated with rosuvastatin (0.1 µmol/l) alone or in combination with LY333531 (10 nmol/l). HUVEC migration and tube formation were assessed. Furthermore, rats with streptozotocin-induced diabetes were randomly divided into groups and treated with either rosuvastatin alone (5 mg/kg/day) or in combination with LY333531 (10 mg/kg/day) for 4 weeks following the induction of myocardial infarction (MI). Echocardiographic patterns, the extent of myocardial fibrosis, capillary density in myocardial tissue, the phosphorylation of Akt and endothelial nitric oxide synthase (eNOS), as well as the expression levels of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor 1-α (HIF­1α) were assessed. The results from the in vitro experiment revealed that the tube-forming and migration ability of the HUVECs exposed to high-glucose medium was significantly improved in the group treated with the combination of rosuvastatin and LY333531. In vivo, the combination of rosuvastatin and LY333531 significantly improved left ventricular function, reduced the extent of myocardial fibrosis and increased myocardial capillary density compared to treatment with rosuvastatin alone. In addition, the expression levels of VEGF, and Akt and eNOS phosphorylation were significantly higher in the group exposed to the combination treatment than in the group treated with rosuvastatin alone. The results of the present study indicate that, compared to treatment with rosuvastatin alone, combined treatment with rosuvastatin and LY333531 promotes a greater level of angiogenesis in diabetic rats with MI. This effect is likely mediated through the upregulation of the VEGF­dependent Akt/eNOS signaling pathway.

Expression of vascular endothelial growth factor and its fetal liver kinase-1 receptor in spinal cord and dorsal root ganglia after neurotomy of sciatic nerve in rats.

OBJECTIVE: To investigate the expression and pattern of vascular endothelial growth factor (VEGF) and its fetal liver kinase-1 (Flk-1) receptor in spinal cord and dorsal root ganglia after neurotomy of sciatic nerve in rats. METHODS: Forty-five adult male Wistar rats were divided randomly into a control group (n=5) and an experimental group (n=40). The bilateral sciatic nerves of the rats in the experimental group underwent neurotomy and the L4-L6 spinal cord and the corresponding dorsal root ganglia were harvested respectively at 8 hours, and 1, 3, 5, 7, 10, 14 and 21 days (8 subgroups with 5 rats each) after operation. The rats in the control group only underwent an exposure of sciatic nerve without neurotomy. Immunohistochemistry and image analysis were used to study the expression of VEGF and its Flk-1 receptor. RESULTS: Both VEGF and Flk-1 receptor expressed in the normal rat spinal cord and dorsal root ganglia. In response to neurotomy, their expression reached a higher level and persisted for a short time then declined to the normal level rapidly. Besides, positive staining of Flk-1 was observed in both glial cells and nerve fibers, which located in the white matter of the spinal cord. CONCLUSIONS: VEGF can promote the regeneration of peripheral nerves from the angle of central neurons, which establishes the experimental and theoretical foundation for VEGF treating peripheral nerve injuries.

[Combined immunosuppression of FK506 and RS-61443 in rat limb allotransplantation].

OBJECTIVE: To study the immunosuppressive effect of combined therapy with FK506 and RS-61443 in rat limb allotransplantation. METHODS: A total of 101 male SD rats were randomly divided into seven groups and used as recipients, and 101 Wistar rats were used as donors. All SD rats were performed limb allotransplantation without using immunosuppressants in control group. In experimental groups (Groups 1-6), the recipients were immunosuppressed with various dosages of FK506, RS-61443 or FK506 + RS61443, after transplantation for 5 weeks. To evaluate the results, we observed circulation of the transplanted limb, the mean rejection time, the histologic grading of skin rejection of limb grafts and the survival time of limb grafts. RESULTS: The control group showed rejection signs (edema and erythema of the skin) after a mean time of 3.36 +/- 1.15 days, and the mean survival time of the allografts was only 7.00 +/- 0.78 days. In the groups only using FK506 or RS-61443, the survival time were prolonged to varying degrees, but rejection occurred even in the period of using drug. As dosage increased, the rejection could not be prevented and the damage to liver and kidney could be induced. In the group using FK506 in combination with RS-61443, only skin and muscle of limb allografts showed slight rejection sign, function of liver and kidney was not obviously affected, the mean survival time of limb allografts was prolonged to 58.76 +/- 6.81 days. CONCLUSIONS: A combination of FK506 and RS-61443 is a more potent immunosuppressive agent than FK506 oro RS-61443 in preventing the rejection of limb allografts, and it can obviously prolong the survival time of limb allografts.