Biomechanical study on the calcaneal fracture fixed by the self-designed calcaneal anatomical plate and pre-cut gudgeon / 中国骨伤

<p><b>OBJECTIVE</b>To study the biomechanical properties of self-designed calcaneal anatomical plate and pre-cut gudgeon system and its efficacy for calcaneal fracture fixation.</p><p><b>METHODS</b>Sixteen fresh foot specimens were randomly divided into experimental group and the control group. Axial compressive load were applied to all specimens in order to create a calcaneal fracture model, and the maximum load and the maximum arch displacement of experimental group were recorded. In experimental group, self-designed intenal fixation system were utilized, while the AO plate internal fixation system were utilized in the control group. Axial compressive test were applied again to both groups, and the maximum load, the foot arch displacement and calcanus broadens were measured and recorded.</p><p><b>RESULTS</b>Comparison between before and after fixing the calcaneus fracture by self-designed internal fixation system in experimental group, the difference of the maximum load was significant (P<0.01), but there was no significant difference (P>0.05) of the maximum arch displacement. All parameters were significantly different (P<0.01) between the experimental group and the control group.</p><p><b>CONCLUSION</b>The fractured calcaneus will be able to regain normal foot biomechanical function after treated by self-designed internal fixation system, and able to support foot arch to bear great load. The self-designed internal fixation and pre-cut gudgeon system is considered to outperform the conventional AO internal fixation system with its better effectiveness and outcome in treating calcaneus fractures.</p>

Changes in neural cell adhesion molecule mRNA expression and protein level in the CA1 region of the hippocampus during long term potentiation induction and maintenance / 生理学报

It has been demonstrated that neural cell adhesion molecule (NCAM) is critical for the induction and maintenance of long term potentiation (LTP) in the CA1 region of rat hippocampus. In the present study, we investigated the changes in NCAM mRNA expression and NCAM protein level after the induction of LTP in vitro using the techniques of in situ hybridization and Western blot. The results showed that the number of NCAM mRNA positive labelled neurons significantly increased (76.6+/-11.5 neurons) 10 min after tetanus when the slope of fEPSP markedly increased. The level of NCAM protein also increased significantly (7.190+/-0.64 arbitrary unit/50 microg protein) 10 min after tetanus. The number of NCAM mRNA positive labelled neurons no longer changed (73.3+/-14.0) 1 h after tetanus, however, the NCAM protein level (9.031+/-0.71) at 1 h after tetanus was higher than that at 10 min after tetanus. Moreover, the NMDA receptor inhibitor AP-5, which blocked LTP, prevented the increase in NCAM mRNA expression and NCAM protein level. The results demonstrate that NCAM mRNA expression maintains a high level, whereas NCAM protein changes from a low level to a high level during induction and maintenance of LTP.

Effects of acute hypobaric hypoxia on spatial learning, memory and its relationship with orphanin FQ of hippocampus in rats / 中国应用生理学杂志

<p><b>AIM</b>To study the relationship between changes of learning, memory and orphanin FQ (OFQ) in hippocampus of rats in acute hypobaric hypoxia at two different altitude levels of 4 500 m(moderate) and 7 500 m(serious).</p><p><b>METHODS</b>Hypobaric chamber, Morris water maze training method and RT-PCR technique were used in the experiment.</p><p><b>RESULTS</b>(1) Compared with the control, the OFQ mRNA expression of hippocampus increased significantly after exposure to acute serious hypobaric hypoxia (8 h/d for 6 d in succession), but obviously decreased after Morris water maze training (6 times/d for 6 d in succession, the latency of place navigation was shortened). (2) After exposure to acute hypobaric hypoxia, the latency of place navigation was markedly elongated, but the OFQ mRNA of hippocampus was significantly higher than that of learning and memory group.</p><p><b>CONCLUSION</b>The hippocampal OFQ was involved in the mechanism of decrease in spatial learning and memory induced by acute hypobaric hypoxia.</p>

Surgery for multiple myeloma of the bone / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the indication, approach and results of the surgical treatment of multiple myeloma.</p><p><b>METHODS</b>The authors reported 29 surgically-treated patients with solitary or multiple myeloma of the bone between January 1997 and January 2002. There are 17 males and 12 females with average age of 59.5 years (range 38 - 76 years). The primary tumour localizations were: vertebral column in 9, rib in1, humerus in 2, proximal femur in 2, femur shaft in 3, pelvis in 6, sacrum in 6. The 29 patients had undergone the following surgical procedures: vertebral tumours were excited through the anterior or posterior approach, combined with a stabilizing procedure in 7 cases. Tumors on thoracic spine were resected using anterior approach. 4 endoprotheses of replacement were performed, indnding two on proximal femur, one on humerus, and one on pelvis. The pathologic fracture was fixated by internal fixation. Neurological impairment was evaluated according to Frankel system. The study evaluated the complications, neurologic function improvement, life quality, and survival after the surgical treatment.</p><p><b>RESULTS</b>The pain was relieved in all cases and the neurological function was improved after the surgery. Local recurrence were found in three cases during the follow-up time.</p><p><b>CONCLUSION</b>The symptom of the patients can be relieved by the surgery. Our experience suggests that surgical interruption on multiple myeloma in some cases may be rewarding.</p>

Relationship between hippocampal long term potentiation induction and activity of 26S proteasome / 生理学报

The present study examined the changes in 26S proteasome activity and the signal molecule mechanism regulating 26S proteasome activity in long term potentiation (LTP) in rat hippocampal slices. The results are as follows: 26S proteasome activity was 190+/-14.3 cpm/(100 microg.2 h) before tetanus, a significant increase in 26S proteasome activity (273+/-18.3 cpm/(100 microg.2 h) was found 10 min after tetanus, when the slope of fEPSP was markedly increased. Interestingly, 26S proteasome activity returned to baseline level (210+/-12.8 cpm/(100 microg.2 h) 60 min after tetanus. Moreover, the N-methyl-D-aspartate (NMDA) receptor inhibitor AP-5, which blocked LTP, prevented the increase in the 26S proteasome activity. The results suggest that NMDA receptors contribute to the transient increase in 26S proteasome activity during induction of LTP in the hippocampal CA1 region.