In clinical practice,we have adopted the methods such as intensifying the knowledge of preclinical medicine,learning to collect case history,training medical check-up,understanding the significance of auxiliary examination and encouraging the students to form the clinical thinking ability,and thus achieved satisfactory effect and obtained the positive opinion of students.

Objective To screen single nucleotide polymorphism(SNP)of DNA methyltransferase 1 gene in patients with systemic lupus erythematosus(SLE).and to investigate the significance of abnormal expression of DNA methyltransferase in the pathogenesis of SLE.Methods Peripheral blood mononuclear cells(PBMCs)were obtained from 11 patients with SLE and 12 normal human controls.DNA was extracted from the PBMCs.and PCR was performed to amplify some exons(1 to 7)and corresponding introns followed by direct sequencing.Results There was a 21397T/C SNP in the intron 7 between exon 7 and exon 8 of DNA methyltransferase 1 gene in patients with SLE.The frequency of CC homozygote increased in patients with SLE compared with that in normal controls(5/11 vs 1/12,X~2=4.10,P＜0.05).Conclusions There is a 21397T/C SNP in DNA methyltransferase 1 gene in patients with SLE.which may be a component of genetic background underlying the abnormal expression Of DNA methyltransferase 1.

Purpose: To investigate the efficacy ofmassotherapy plus warming acupuncture for treatment of patellar malacia. Methods: Seventy-two patients with patellar malacia were randomly divided into observation and control groups, treated by massotherapy plus warming acupuncture and simple medication, respectively. Results: The effective rate was 83.3% in the observation group and 56.7% in the control group. There was a significant difference in curative effect between the two groups (P＜0.01). Conclusion: The curative effect of massotherapy plus warming acupuncture on patellar malacia is superior to that of simple medication.

Post-stroke infection mainly includes stroke-associated pneumonia and urinary tract infection.It is one of the major causes of increasing disability and mortality in patients with stroke.Its occurrence and development is associated with the basal state,stroke location,infarct volume,severity,dysphasia,aphasia and other factors of the whole body system in patients with stroke.In recent years,stroke-induced immunosuppression is receiving increasing attention.

Objective To investigate the effect of adenosine on pulmonary injury after extracorporeal circulation. Methods Twelve mongrel dogs were randomly divided into two groups, the test group and control group. The model of extracorporeal circulation was established. In the test group and control group, adenosine(50μg/kg*min) and normal saline were infused before extracorporeal circulation respectively. Hemodynamics, right cardiac function and arterial blood gas were assessed. Lung water and malondialdehyde content were assessed. Histological evaluation was also made. Results　There were no differences between the two groups with respect to heart rate, mean systemic artery pressure, left atrial pressure, and central venous pressure. In the test group, pulmonary vascular resistance was lower and right cardiac function improved remarkably; arterial oxygen pressure (PaO2) was also higher, less lung water was observed and the malondialdehyde content in the pulmonary tissue was lower (P＜0.05,P＜0.01). Histological evaluation of the test group revealed normal pulmonary architecture without abundant intra-alveolar neutrophils. Conclusion Adenosine can attenuate ischemia-reperfusion lung injury and right cardiac insufficiency caused by extracorporeal circulation. At a proper dose, there was no significant effect on systemic hemodynamics.

Objective To explore the possibility of bone marrow mesenchymal stem cells (MSCs) differentiating into active melanocytes in vitro.Methods Bone marrow stromal cells were harvested from femoral marrow of 6-week-old black male C57BL/6 mice,and subjected to a primary culture.After 6-passage subculture,an induction medium containing hydrocortisone,recombinant human insulin,transferrin and fibroblast growth factor was used to induce the differentiation of MSCs into melanocytes.Inverted light microscopy was applied to observe the process of cell differentiation,transmission electron microscopy to observe melanosome formation and maturation,and immunocytochemistry to determine the expression of melanocyte-associated epitopes,and flow cytometry to analyze cell cycles and yield of differentiated melanocytes.Results The total number of MSCs was close to 109 after 6 passages of subculture,and immunofluorescent studies showed an expression rate of 94.3％ for CD44 and 82.3％ for CD105 in these MSCs.After 180-day cultivation in the induction medium,the MSCs showed a morphological similarity to melanocytes with an increase in dendrites,formation of melanosome-like structures,and cell growth cycle was shortened to 3-4 days.Brown/black cell sediments were visualized by naked eyes.Electron microscopy revealed that intracellular melanosomes were mainly in Ⅳ phase.Immunofluorescence studies of the differentiated melanocytes showed a positive staining for tyrosinase related protein-1 (TRP-1),TRP-2,and microphthalmia-associated transcription factor (MITF).Flow cytometric analysis showed that most of the melanocytes differentiated from the MSCs were in G1 and S phases,and TRP-1-positive melanocytes amounted to 80％ of gate cells.Conclusions Bone marrow MSCs can be largely differentiated into melanocytes with a close similarity to normal melanocytes in morphology,ultrastructure and specific epitopes and a certain degree of proliferative activity.

BACKGROUND:Few reports are found about the effect of ovariectomized rats' bone histomorphometry parameters using non-destructive dynamic loading system.OBJECTIVE:To observe the effect of different loads situations on the bone histomorphometry parameters in ovariectomized rats.DESIGN,TIME AND SETTING:A controlled observation on the bone histomorphometry was performed in the Biomedical Engineering Laboratory of Jilin University from April 2007 to August 2007.MATERIALS:A total of 35 9-month-old Sprague-Dawley female rats were randomly divided into five groups,including sham operation group,ovariectomized (OVX) control group,OVX loading 1 N group,OVX loading 2 N group,OVX loading 4 N group.There were 7 rats in each group.METHODS:Rats in OVX control group and castration load group were processed into bilateral OVX on the back. The sham operation group only underwent the excision of fat tissues on back,and then sutured. After castration for 1 week,rats were loaded with non-destructive dynamic loading system in the two sides of the tibia,15 minutes a day. The mechanical loads would continue for 4 weeks and the loads were 1N,2N and 4N.MAIN OUTCOME MEASURES:Changes of proximal tibia bone histomorphometry parameters.RESULTS:The area,number and thickness of trabecular bone in OVX loading group were all higher than OVX control group (P＜0.05,P＜0.01).The trabecular bone area and thickness in OVX 4 N and OVX 2 N groups were significantly higher than OVX control group (P ＜ 0.001).There was a downward trend of trabecular separation in OVX 4 N group compared with OVX control group (P ＜ 0.05). With the increasing loads,there was an increasing trend of the area,number and thickness of trabecular bone,which were close to sham-operated group. The trabecular separation was declined. Single fluorescent labeled surface and double fluorescent labeled surfaces in sham operated group were all lower than that in OVX control group. With the increase in loads,the single fluorescent labeled surface,double fluorescent labeled surface,interlabeled width and mineral apposition rate had been shown to increase. The OVX 2 N and OVX 4 N groups exhibited a remarkably higher level of mineral apposition rate than OVX control group (P ＜ 0.05).CONCLUSION:With the increase in load at the range of 1-4 N,all parameters of bone histomorphometry improve in the OVX rats,the bone microstrcture is greatly ameliorated,bone mass loss is reduced and the process of osteoporosis is delayed.

Objective To observe the operation methods and curative effect of sacroiliac joint screw fixation by using traditional imaging monitoring technique in combination with sacral slope position imaging monitoring technique. Methods After bone traction and enema cleansing, 37 patients with pelvic fractures were fixed with sacroiliac joint screws, which was monitored under C-armed X ray machine at slope position, inlet and outlet views. There were 23 males and 14 females, at average age of 30. 8 years (18-63 years). Results All the patients were followed up for 4-23 months (average 9. 8 months) , which showed basic anatomical restoration in 28 patients, coronal section dislocation for 2 mm in seven and dislocation for 5 mm in two. All fractures were healed, with no nerve or blood vessel complications found. According to Majeed scoring, the excellence rate was up to 94. 5%. Conclusions Combined use of traditional imaging monitoring and sacral slope position imaging monitoring can help improve the safety of percutaneous iliosacral screw fixation, simplify operation process and shorten operation time.

BACKGROUND: Guided tissues regeneration (GTR) has been successfully used in the treatment of periodontal diseases by using biocompatible membrane to prevent tooth epithelial cell growing towards root and to facilitate the formation of a certain gap which is favorable for periodontal membrane cells to occupy the surface of the root, thereby to rebuild the peridental structure. OBJECTIVE: To verify whether GTR can promote the repair of periodontal bone defect and the formation of new bones and whether combined use of GTR membrane, artificial bone, and growth factors can acquire much more new periodontal tissue. DESIGN, TIME AND SETTING: An animal observation experiment was performed at the laboratory of Medical College of Dalian University between February and July 2006. MATERIALS: Basic fibroblast growth factor (bFGF) freeze-dry powder (50 mg/ampoule) was thoroughly dissolved with ddH2O to prepare 5 g/L bFGF solution, bFGF solution was dropped onto collagen membranes with a size of 10 mm ×10 mm (5 mg bFGFs per piece of collagen membrane). METHODS: Cementum and the alvelor bone 6 mm below the cement-enamel junction were removed to induce periodontal defect in 16 rabbits with big ears. Artificial bone with bFGF and GTR membrane were used to fold around the defect on the right side, followed by reduction and suture, serving as experimental side. The left side underwent identical experimental procedure, with the exception of application of artificial bone with bFGF and GTR membrane, serving as control side. MAIN OUTCOME MEASURES: Carrier material absorption, inflammation of inner connective tissues, and status of junctional epithelium were examined through the use of microscope. RESULTS: The control side exhibited no concrescence, while the expedmental side displayed concrescence of the cementum to various extents. CONCLUSION: Application of GTR membrane, artificial bone, and bFGF can promote the concrescence of damaging bone.