AIM: To observe the changes in platelet-activating factor(PAF) receptor binding characteristics and explore the action of PAF on formation of thrombotic core and penumbra following local cerebral ischemia.METHODS: Neuron's membrane protein was abstracted, and the local cerebral ischemia model were induced by photochemistry in tree shrews. The PAF binding sites on central neuron membrane were studied by -PAF binding assay.RESULTS: There were two different affinities of PAF receptors on tree shrew's brain cell membrane, with kD 1=( 3.61 ? 0.72 ) nmol/L and kD 2=(17 04?2 41) nmol/L, corresponding respectively to maximum number of binding sites: Bmax1=(1 457 94?168 01) pmol/g protein and Bmax2=(5 017 40?742 16) pmol/g protein. The binding sites decreased in ischemic core, penumbra and contralateral regions at 4,24 and 72 h after ischemia ( P

Objective　In order to predict or exclude early ectopic pregnancy.Methods　Endomertrium of 49 early intrauterine and 52 ectopic pregnancy were observed by transvaginal ultrasonography. Trophoblastic artery flow were investigated surrounding the intrauterine embryo or within the endometrium.Results　An endometrial three-line pattern resembled late proliferative endometrium of the normal menstrual cycle were seen in 42 ectopic pregnancy(80.8%). An endometrial three-line pattern were not seen in 49 early intrauterine pregnancy. Thirty-nine early intrauterine pregnancy had trophoblastic artery flow surrounding the intrauterine embryo or within the endometrium. None of ectopic pregnancy had trophoblastic artery flow within the endometrium.Conclusion　Observation of endometrial three-line pattern and trophoblastic artery flow by transvaginal ultrasonography were useful for diagnosing eraly ectopic pregnancy.

BACKGROUND: Cervical orthosis is one of the non-surgical therapeutic methods for the remedy of cervical deformities. The introduction of cervical orthosis into the clinical remedy of cervical deformities resulted by burn can maximally restore the cervical function of the patients.OBJECTIVE: To analyse the clinical applicative mode and the effects of moulded cervical orthosis (MCO) on cervical burn.DESIGN: A before-and-after verification study by employing pateitns as subjects.SETTING: Prosthetics and orthotic department in a provincial artificial limb center.PARTICIPANTS: Totally 19 cases including 13 males and 6 females after skin-transplantation due to serious burn in head, neck and chest admitted by the outpatient department of prosthetics center between January and September 2003.METHODS: Nineteen patients with cervical burn wore MCO. Return visits were made afterwards for the evaluation of the treatment effects of MCO.MAIN OUTCOME MEASURES: Resutls of therapeutic effectiveness evaluation.RESULTS: All nineteen patients with cervical deformities due to burn reached the effects of correcting cervical flexion and restoring cervical functions through wearing orthosis. The cervical functions restored entirely in seven cases, almost restored in eight cases and improved in four cases.CONCLUSION: MCO can be clinically used on cervical deformities resulted by burn and provide good effects on remedy and rehabilitation.

Objective To observe the role of the posterior e lements of the spine in the spinal cord injuries and to provide the basic evidence for proper evaluation of the se verity of spinal cord injuries and th e possibilities of functional recove ry.Methods Experimental study:The experiment al model of spinal burst fracture was established in the thoraco-lumbar column section which subjected high velocity vertical loadi ng in static pattern.The pressure changes in the vertebral canal and the severity of posterior elements of the spin e were observed,and then their relationship was studied.Clinical Study:The data were obtained from 127consecutive cases of thoraco-lumbar burst fracture associated with paraplegia.The relationship between t he severity of spinal cord injury,functional recovery and the posterior elements injuries was studied retrosp ec-tively.Results The experimental study showed that g reat pressure changes appeared in th e vertebral spec-imens without posterior elements in juries.On the contrary,the peak value of pressure was low in cases with posterior elements injuries.Clini cal results:Of 38cases(69.09%)with spinal cord injuries in 55patie nts without posterior elements injurie s,functional recovery was found in 24cases(63.16%).In another group,of 52cases(72.22%)with spinal cord injuries in 72patie nts with posterior elements injurie s,functional recovery was found in 20cases(38.46%).The statistic difference between t he two groups indicated that the severity of spinal cord injuries in t he patients without posterior eleme nts injuries was more severe than that with posterior elements injuries.Conclusion The spinal posterior elements play a n important role in spinal cord injuries.The severity of posterior elements injuries can be used as a sca le in the evaluation of the severity o f spinal cord injuries,functional re covery and improvement of Denis classification.[

In this experiment, primary mixed culture cells of lung and liver derived from new born mouse was made use of target cells, 0.1 ?Ci 3~H-TdR per milliliter medium was added in the culture in order to induce malignant transformation of the cells in the culture. Results of the experiment was that the cells effected by 3~H-TdR had a unlimited growing and formed sarcoma after being inoculated into new born mice immunosuppressed with ATS. It suggested that they had became malignant transformation cells. Results of analysis of chromosome aberrations of the transformed cells, the long arm chromosome was observed in 5% of cells, the metacentric chromosome in 7% of cells, the acentric fregment in 8% of cells. It shows that DNA damage of the cells induced by 3~H-TdR causes their chromosome aberrations and, futhermore, development of malignant cells. The fact that unstable aberrations was Still in sight in the malignant transformation cells suggested that there have been a bit of 3~HTdR left in these cells which kept damaging DNA of the cells.

According to ZFY gene sequence on Y-chromosome, which supposedly codes for the testis determining factor (TDF), a pair of primers F3.2 and F4.2 were designed to specifically amplify 650 bp DNA fragment. The amplified product was electrophoresized on 1.5% agarose gel stained with EB, and then directly visualized under UV. This protocol resulted in constantly producing 650 bp band of the specific product by amplification of 500 pg male genomic DNA and had the same result when mixed with 100 fold amount of female genomic DNA. When this method was used to detect Y-ZFY of chorionic villi and amniotic fluid in 20 samples respectively, its accuracy for determining fetal sex reached 100 percent.

Objective To evaluate the value of spiral CT and 3D reconstruction in diagnosis and treatment of tibial plateau fractures.Methods 25 cases with tibial plateau fractures were examined with plain radiograhs,spiral CT and 3D reconstruction during July,1998 to December,2000.The tibial plateau fractures were classified according to Schatzker′s classification on the X-rays and 3D reconstruction images.On the superior view the tibial plateau fractures were divided into anterior lateral,posterior lateral,anterior medial and posterior medial fractures.Results 3D reconstruction images of 25 plateau fractures were the same as what arthroendoscopy were.25 fractures(including 23 arthroscopic management fractures)were operated under 3D reconstruction guide.No one case was infected.The treatment was valid.Conclusion Spiral CT and 3D reconstruction can offer more accurate classification and complement to new spatial classification of fractures.Also can provide better planning and management for the tibial plateau fractures.

Objective To observe the somatic embryogenesis in in-vitro cultured Dendrobium candidum wall.Ex Lindl.(DCWL),and to supply evidence for its rapid propagation and germplasm preservation.Methods Protocorm-like bodies and callus of DCWL subcultured for 30 days was used as the explants,N6 was used as the basic culture with phytohormone added,and fungal extracts as the elicitor.Protocorm-like bodies and callus of DCWL were used for induction culture.Results Somatic embryogenesis in in-vitro cultured DCWL derived from the epithelial cells or inner cells of callus of DCWL.Conclusion A large amount of buds can be obtained by the induction and culture of protocorm-like bodies and callus of DCWL.

This paper analyzed the status of the medical students'volunteer services in China and abroad , dis-cussed the feasibility and necessity of medical students'volunteer service .The influence factors , elvaluation and ef-fectiveness of the medical students'volunteer services were sumed up , and its development tendency was also dis-cussed .The following suggestions were put forward , namely improving the volunteer service participation , making the voluntary service a routine work , aiming to giving references for medical schools and volunteer organizations car-rying out the medical students'volunteer services .

Objective To explore the effect of Acorus gramimeus and its major components ?-asarone on N-methyl-D-asperate recepter 1 (NMDAR1) mRNA levels of hippocamp neurons in epileptic animal models induced by pentylenetetrazol (PTZ). Methods PTZ 60 mg/kg was injected to the abdominal cavity of three weeks Wistar rats to prepare epileptic animal models. The animal models were randomly divided into three groups: epilepsy control, A. gramimeus and ?-asarone as well as the normal control. Each group was administered through intraperitoneal injection. Both of two control groups were injected physiologic saline 1.0 mL/d, and the rest groups were injected A. gramimeus 2 350 mg/(kg?d) or ?-asarone 29 mg/(kg?d) for 7 d, respectively. All rats were treated by PTZ 60 mg/kg through intraperitoneal injection next day. After their behaviors were observed for 24 h, animals were sacrificed. The expressions of NMDAR1 mRNA in hippocamp CA1 and CA3 of all rats were detected by in situ hybridization and semiquantitative RT-PCR. Results The results of in situ hybridization showed that positive staining granules were located in the cyptoplasm of hippocamp neurons. The number of positive cells and average absorbance of A. gramimeus group or ?-asarone group was markedly less than that of epilepsy control (P