L-364,718 potentiates electroacupuncture analgesia through cck-a receptor of pain-related neurons in the nucleus parafascicularis.

Electroacupuncture (EA) has been successfully used to alleviate pain produced by various noxious stimulus. Cholecystokinin-8 (CCK-8) is a neuropeptide involved in the mediation of pain. We have previously shown that CCK-8 could antagonize the analgesic effects of EA on pain-excited neurons (PENs) and pain-inhibited neurons (PINs) in the nucleus parafascicularis (nPf). However, its mechanism of action is not clear. In the present study, we applied behavioral and neuroelectrophysiological methods to determine whether the mechanisms of CCK-8 antagonism to EA analgesia are mediated through the CCK-A receptors of PENs and PINs in the nPf of rats. We found that focusing radiant heat on the tail of rats caused a simultaneous increase in the evoked discharge of PENs or a decrease in the evoked discharge of PINs in the nPf and the tail-flick reflex. This showed that radiant heat could induce pain. EA stimulation at the bilateral ST 36 acupoints in rats for 15 min resulted in an inhibition of the electrical activity of PEN, potentiation of the electrical activity of PIN, and prolongation in tail-flick latency (TFL), i.e. EA stimulation produced an analgesic effect. The analgesic effect of EA was antagonized when CCK-8 was injected into the intracerebral ventricle of rats. The antagonistic effect of CCK-8 on EA analgesia was reversed by an injection of CCK-A receptor antagonist L-364,718 (100 ng/µl) into the nPf of rats. Our results suggest that the pain-related neurons in the nPf have an important role in mediating EA analgesia. L-364,718 potentiates EA analgesia through the CCK-A receptor of PENs and PINs in the nPf.

Visible luminescence mechanism of ZnO nanoparticles synthesized by sol-gel method.

We presented our investigations on the absorption and emission properties of the nanocrystalline ZnO particles of different particle sizes (2 nm-5 nm) by sol-gel method. In the room temperature PL spectra, three emission bands, ultraviolet (UV), blue and green were observed. With increasing the particle sizes, both the UV and the visible emission bands shifted to lower energies progressively. From the size-dependency, there was a linear relationship between the energetic maxima of the UV and the green emission bands with a slope of about 0.26, which indicated that the green luminescence of ZnO was produced by the transitions of electrons from deep level to the valence band (or shallow acceptor level). A linear dependence was also found between the energetic maxima of the UV and the blue emissions with a slope of 0.15, the origin this blue emission band is not clear at present. While in van Dijken et al.'s paper, however, they identified only two emission bands in the emission spectra, an UV and a broad visible emission band, and the linear fit between the energetic maxima of these two bands in particles of different sizes has a slope of 0.6, so they proposed that the visible emission in ZnO was originated from the recombination of a shallowly trapped electron with a deeply trapped hole. We attributed this divergence to the fact that the broad visible band is actually composed of two separate emission bands originated from two different recombination processes, and should not had been treated as one emission band.

Probing the visible luminescence mechanism in ZnO nanoparticles by band edge modulation.

The visible luminescence mechanism of ZnO is an important but controversial problem. In this paper, we report the structural and optical properties of Mg-doped ZnO nanoparticles (approximately 3-4 nm) synthesized via the sol-gel method. X-ray diffraction (XRD) analysis and absorption spectra observations revealed that Mg ions replace Zn ions in the lattice. In the room temperature photoluminescence (PL) spectra, three emission bands, ultraviolet (UV), blue, and green, were observed. With increasing concentration of Mg, the near band edge (NBE) emission band progressively shifted to the higher energy side. The green emission in the visible emission band, however, presented an inconspicuous shift. The reason is probably that the bottom of the conduction band in ZnO is determined by the Zn 4s state, and the top of the valence band is determined by the O 2p state. Mg ions in ZnO substitute for zinc ions and enter a slightly distorted tetrahedral site, which causes the bottom of the ZnO conduction band to be shifted to higher energy and leaves the top of the valence band unchanged. This combined with the fact that the deep level position is insensitive to the shift of the band edge led us to conclude that the green emission originates from electronic transition between the deep defect level and the top of the valence band (or very shallow acceptor level).

Ten-year experience with living related donated splenic transplantation for the treatment of hemophilia A.

AIM: Six cases of hemophilia A treated with living related donated splenic transplantation (LRDST) were performed over 10 years. METHODS: We reviewed the six consecutive cases of LRDST from 1992 to 2002. Three patients received whole spleen allografts and the other three, partial spleen allografts. All allografts were transplanted to the extraperitoneal space in the right iliac fossa by an end-to-end anastomosis between the splenic artery and the internal iliac artery and an end-to-side anastomosis between the splenic vein and the external (or common) iliac vein. After the operation, a combined regimen with cyclosporine, azathioprine, anti-lymphocyte globulin, OKT3, was administered to suppress the immune reaction. RESULTS: The functional period of the allografts varied between 30 days to 4 years. Patient factor-VIII (F-VIII) levels rose from less than 5% before operation to 15% to 56% postoperatively. One patient died from central nervous system complications. Another lost his graft because exogenous F-VIII was not supplemented in timely fashion at the onset of rejection. And the third could no longer afford the expensive immunosuppressive drugs at 2 years after the operation and eventually lost the spleen. The remaining three patients presently have regained self-support, among whom one has survived for 4 years. CONCLUSION: Though the sample pool is relatively small, our clinical observations tend to confirm LRDST as a feasible, effective treatment for hemophilia A.

Clinical application of serial operations with preserving spleen.

AIM: To evaluate the clinical application of serial operations with preservation of spleen. METHODS: Serial operations with preserving spleen were performed on 211 cases in our hospital from 1980 to 2000. The patient's age ranged from 13 to 56 years, averaging 38 years. Diseases included splenic injury in 171 cases, portal hypertension in 9 cases, splenic cyst in 10 cases, and the lesion of pancreatic body and tail in 21 cases. RESULTS: All the cases were cured, and 129 patients were followed up from 3 months to 3 years with the leukocyte phagocytosis test, detection of immunoglubin, CT,(99m)Tc scanning and ultrasonography. The results were satisfactory. CONCLUSION: The operations with preserving spleen were safe, feasible, and worth of clinical application.