[Study on efficacy specificity of electroacupuncture at "Zusanli "(ST36) and "Baihui" (GV20) in cerebral ischemia and inflammatory pain rats].

OBJECTIVE: To explore the efficacy difference between electroacupuncture (EA) at "Zusanli" (ST36) and "Baihui" (GV20) for inflammatory pain and cerebral ischemia-reperfusion injury (CIRI) in rats. METHODS: In 1st part of this study, 90 male SD rats were randomly divided into sham-operation, model (induced by occlusion of the middle cerebral artery and reperfusion), GV20 EA, ST36 EA，and sham EA groups (n=16 in each group). In the 2nd part of the study, 40 male SD rats were randomized into saline injection (control), inflammatory pain model (subcutaneous injection of complete Freund's adjuvant ［CFA］ into the right paw), ST36 EA, GV20 EA, and sham EA groups (n=8 in each group). In these two parts, EA (2 Hz/15 Hz, 1 mA) was applied to ST36 or GV20. The mechanical withdrawal threshold (MWT) and thermal withdrawal latency （TWL） were detected 2.5 h after administration of CFA by using Von Frey and plantar tester, respectively. The neurological deficit scores (NDS) were assessed by using Longa's method and the infarct size of the brain assessed after staining with 2% triphenyltetrazolium chloride (TTC). The expression of c-fos protein in the dorsal horns (DHs) of the spinal cord was detected by immunohistochemistry. RESULTS: (1) Twenty-four hours following CIRI, the NDS and infarct volume were significantly increased in the model group compared with the sham-operation group (P<0.01), and obviously decreased in the GV20 EA and ST36 EA groups relevant to the CIRI model group (P<0.05, P<0.01). There were no significant differences between the two EA groups in the NDS and infarct volume levels (P>0.05). (2) After administration of CFA, both the MPT and TPT were notably decreased in the inflammatory pain model group in contrast to the saline-injection group (P<0.01), but were considerably increased in both ST36 EA and GV20 EA groups (P<0.05), rather than in the sham EA group (P>0.05). The number of c-fos positive cells was significantly increased in the medial half of I-II and III-IV lamina of DHs in the L4-L6 segments of spinal cord in the inflammatory pain model group relevant to the saline-injection group (P<0.01,P<0.05), and was remarkably decreased in the lamina I-II (not in the deeper lamina) in both ST36 EA and GV20 EA groups (P<0.01), rather than in the sham EA group (P>0.05). No significant differences were found in the number of c-fos positive cells between the ST36 EA and GV20 EA groups (P>0.05). CONCLUSION: Our data do not support the specificity of functions at least between GV20 EA and ST36 EA in both CIRI and inflammatory pain model rats. This is the first study reporting the effect of EA at GV20 for relieving CFA-induced inflammatory pain.

Hydrothermal Aging Properties of Three Typical Bamboo Engineering Composites.

The objective of this study was to investigate the hygroscopic characteristics of three typical bamboo engineering composites (Bamboo scrimber (BS), bamboo bundle/wood laminated veneer lumber (BLVL), and bamboo laminated timber (BLT)) as well as predict their performance changes and service life in hot humid environments. The composites were subjected to three treatment conditions (23 °C, 63 °C, and 100 °C) for this experiment. The hygroscopic thickness swelling model and Fick's second law were used to quantify the characterization and prediction of the water absorption, thickness swelling rate, and water absorption rate of BS, BLVL, and BLT. The results indicated that the order of the hygroscopic thickness swelling coefficient KSR and the diffusion coefficient D was BLT > BLVL > BS (at 23 °C and 63 °C). The optimal dimensional stability was displayed by BS, followed by BLVL and BLT. In addition to the hygroscopic properties, elastic modulus degradation was investigated. It was observed that the elastic modulus (MOR) degradation had a linear relationship with the aging temperature. After 152 h of the hydrothermal aging test (63 °C), the MOE of BS, BLVL, and BLT degraded by 44.33%, 53.89%, and 25.83%, respectively.

An experimental rabbit model of symptomatic cerebral vasospasm with in vivo neuroimaging assessment and ex vivo histological validation.

Cerebral vasospasm (CVS) is a severe complication that occurs following aneurysmal subarachnoid hemorrhage (SAH). Magnetic resonance angiography (MRA) has been used to evaluate brain injury following SAH in humans. The present study was designed to assess a rabbit model of symptomatic CVS (SCVS) and the utility of MRA in evaluating SCVS in rabbits. Japanese white rabbits (n=24) were randomly divided into 2 equal groups: A sham group and a SAH group. Neurological scores were evaluated for 7 days following SAH. Basilar artery (BA) diameters were measured using MRA preoperatively and 7 days postoperatively. Rabbits were sacrificed 7 days following SAH and the BA diameter of each rabbit was determined using histological evaluation. Compared with the Sham group, neurological function was significantly reduced in the SAH group at all time points (P<0.05). Furthermore, the BA diameter was significantly smaller in the SAH group on day 7 compared with the baseline measurement (P<0.05). No significant difference was observed between histological and MRA findings in either group at day 7. Histological changes in the hippocampus consistent with ischemia were observed in the SAH group. Hippocampal ischemia was also identified in the SAH group via MRA and there was no difference in detection rates following the use of MRA and histochemistry. MRA appears to be an effective method for assessing vasospasms of the BA and ischemic changes to the hippocampus in a rabbit model of SCVS. Furthermore, the animal model used in the present study may be beneficial for the future study of SCVS.