Common Cold ; drug therapy ; epidemiology ; virology ; Humans ; Rhinovirus ; genetics ; isolation & purification

In recent years, the virtual surgery training system with force feedback has provided a new way for young doctors to improve their surgical skills in a safe, efficient and flexible training method. Precise drilling force and realistic hand feeling of manipulation are the cruxes in the virtual surgery training, and the accurate simulation of bone drilling depends on the accurate establishment of drilling force prediction model. The establishment of force prediction model with finite element analysis is the key part in the development of virtual training system. In this paper, the current research status of finite element analysis of bone drilling presented in four aspects: bone model reconstruction, material model, mesh model and prediction of drilling force, especially the construction of bone tissue material model is discussed in detail and several important models are analyzed. This paper presented a relatively complete overview of the approaches commonly used in this research field to promote the establishment of more accurate force prediction models of bone drilling.

BACKGROUND: Studies have shown that adipose derived mesenchymal stem cells are involved in the skin repair after scald, but the hydrogel made of the excreta by adipose derived mesenchymal stem cells is rarely reported in the treatment of skin scald. OBJECTIVE: To analyze the therapeutic effect of human adipose derived mesenchymal stem cell conditioned medium hydrogel in a mouse model of skin scald. METHODS: Adipose derived mesenchymal stem cells were obtained from adipose tissues by enzyme digestion combined with adherent culture method. Morphological and flow cytometry were used to identify phenotype and induce differentiation. Secondly, the stable proliferative phase cells were harvested to obtain the conditioned medium, and chitosan, mannitol, beta-glycerol phosphate sodium and hyaluronic acid were added to prepare the thermosensitive hydrogel. Then the 95 ℃ aluminum block was used to rapidly establish a model of degree III skin scald on the left (experimental group) and right (control group) sides of the back of 24 C57BL/6 mice. In the experimental group, adipose derived stem cell conditioned medium hydrogel was applied twice a day on the right side of the mouse back, and in the control group, fresh medium hydrogel was applied twice a day on the left side of the mouse back. The treatment period lasted for 7 days. Healing time and healing process were observed to calculate the healing rate. Histopathological changes were observed by hematoxylin-eosin staining at paraffin sections at 4, 14, 28 days after skin scald. RESULTS AND CONCLUSION: (1) The human adipose derived mesenchymal stem cells had fibroblast-like morphology and proliferated vigorously, and the average doubling time was 55 hours. These cells could be induced to differentiate into osteoblasts, chondrocytes and adipocytes. High expression of CD29, CD44, CD90 and CD105 were observed on these cells with low expression of CD31 and CD34, which met the standard of mesenchymal stem cells. (2) Thethermosensitive hydrogel prepared by the conditioned medium was cool and transparent viscous liquid at 4-20 ℃, and was changed into semi-solid gel at( 37 ℃ after 15 minutes. (3) The normal structure) subcutaneous fat and muscle tissue (of 95 ℃ aluminum block scalded mice wer) standards of degree III burns. The wound area was roughly 3 cm2. (4) In the repair process, shorter wound healing time, less scar and better dermis structure were observed in the experimental group compared with the control group. (5) Inflammatory infiltration, thickness of granulation tissue, epidermal thickness, fibroblasts and vascular density were significantly improved in the experimental group as compared with the control group (P < 0.05). To conclude, human adipose derived mesenchymal stem cells conditioned medium hydrogel can promote the wound healing and promote the quality of regenerated skin after skin scald.

Objective To explore the relationship between DNA repair gene XRCC1 and XPD polymorphisms and individual susceptibility to prostate cancer. Methods PCR-restriction fragment length polymorphism assay was used to analyze the XRCC1 (C26304T and G28152A) and XPD A35931C polymorphisms in 358 prostate cancer patients and 312 healthy controls. Unconditional logistic regression analysis was performed to calculate odd ratio (OR) and 95% confidence interval (CD for estimating the correlation between different genotypes and prostate cancer risks. Results Forty-seven(13.1%) cases present XRCC1 28152AA genotype in prostate cancer group, while 24 cases in the control group (7. 1%), individuals with this genotype had a significantly increased risk for prostate cancer (OR 1. 924, 95%CI=1.126 - 3. 288, P=0. 017). There was no significant difference between two groups at XRCC1 C26304T and XPD A35931C sites. Combined analysis of the three sites polymorphisms showed that individuals with XRCC1 28152 AA and XPD 35931AC+CC genotype had a higher risk of prostate cancer than those with three wild genotypes (OR = 3. 087,95%CI 1. 081 - 8.813;OR = 3. 376,95%CI 1.067-10.683;OR 3. 216,95%CI=1. 439-7.188,P = 0. 004). Analysis stratified by age of onset, PSA, Gleason score and T stage revealed that XRCC1 28152AA and XPD 35931 AC+CC high-risk genotype was especially associated with early age at onset of prostate cancer (P<0. 05). Conclusions The XRCC1 and XPD genotypes may be contributed to the risk of developing prostate cancer, particularly for younger patients.

OBJECTIVEThe present study is concerning qualitative and quantitative detection of Poria cocos quality based on FT-near infrared (FT-NIR) spectroscopy combined with chemometrics.

METHODThe Poria cocos polysaccharides contents were determined by UV. Transmission mode was used in the collection of NIR spectral samples. The pretreatment method was first derivation and vector normalization. Then principal component analysis (PCA) was used to build classification model and partial least square (PLS) to build the calibration model.

RESULTThe results showed that conventional criteria such as the R, root mean square error of calibration (RMSEC), and the root mean square error of prediction (RMSEP) are 0.944 0, 0.072 1 and 0.076 2, respectively. The misclassified sample is 0 using the qualitative model built by PCA.

CONCLUSIONThe prediction models based on NIR have a better performance with high precision, good stability and adaptability and can be used to predict the polysaccharose content of Poria cocos rapidly, which can provide a fast approach to discriminate the different parts of Poria cocos.

Objective To investigate the forensic characteristics of death cases of EV71 through retrospective analysis of 9 death forensic cases of Enterovirus 71 (EV71) . Methods Nine cases of EV71 death cases were collected,and the population characteristics, histopathological change,toxicology,pathology and causes of death of these cases were discussed. Results All 9 patients had fever, cough, emesis, and were treated as influenza or hand-foot and mouth disease (HFMD) in local hospitals, the condition was still deteriorating and finally died. The 9 autopsy cases were diagnosed as brain stem encephalitis and death in forensic diagnose. Conclusion The HFMD disease caused by EV71 infection progresses rapidly often leads to medical disputes, the patient's family and hospital's opinions on the causes of death in patients are often different,identifying the cause of death is conducive to resolve the disputes.

BACKGROUND:At present, there are several limb-preserving methods,such as xenogenic bone joint replacement, artificial metal prothesis replacement and inactivation and replantation of tumor bone segment, etc.Each method has its advantages and disadvantages. In addition, mismatch of xenogenic and autogeneic joints and articular cartilage necrosis in the late stage, which affects joint function, are two important problems for large frozen bone-joint allograft at ultra-low temperature in repair of bone defect following bone tumor resections in extremities.OBJECTIVE:To evaluate a method to obtain outline information on the cartilage surface through spiral CT scanning data, so as to lay foundation for study on individualized artifical semi-knee joint based on rapid prototyping (RP) technique.DESIGN: Open experiment.SETTING: First Department of Trauma, Urumqi General Hospital of Lanzhou Military Area Command of Chinese PLA.MATERIALS: This experiment was carried out at Institute of Orthopaedics, Xijing Hospital, Fourth Military Medical University of Chinese PLA, and Institute of Advanced Manufacturing, Xi'an Jiaotong University from September 2001 to May 2003. CT scanning subject was a 25-year-old healthy male volunteer.METHODS:Distal femur was performed 1 mm in thickness scanning with Picker 6 000 spiral CT. Three-dimensional volume reconstruction was conducted at the Voxel Q Image workstation on Picker 6000 CT, then, two-dimensional tomography image of reconstruction data were downloaded with spacing of 0.1 mm. Data format converter software was self-developed. The downloaded image was treated through smoothing, de-noise and so on.Vector data of two-dimensional borderline outline of tomography image was calculated and input into Surfacer 9.0 software (American Imageware company) for vectorial three-dimensional reconstruction. According to recognition of articular cartilage outline and request of prothesis design, the threedimensional images of interested articular cartilage surface outline were extracted and used in the computer-aided design for individualized artificial semi-knee joint.MAIN OUTCOME MEASURES:Vector converting of CT image and vector image of three-dimensional reconstruction of femoral condyle.RESULTS:Vector converting of CT image dafa had been come true using self-developed medical image vector converter software. Three-dimensional solid model of individualized femoral condyle was constructed with Surfacer9.0 three-dimensional processing software and edited according to design request. Three-dimensional model of articular cartilage requested by artifical semi-knee joint prothesis was extracted for computer-aided design. The constructed articular surface outline could be treated further to complete computer-aided design of artificial semi-knee joint prothesis; The file format was .stl, which could be recognized by RP software and used in engineering.CONCLUSION:Vector reconstruction of articular cartilage outline is performed based on spiral CT data that can obtain precise three-dimensional solid model of articular cartilage outline. The three-dimensional model can be edited, which lays foundation for computer-aided design and RP manufacturing of artificial semi-knee joint prothesis compounded with large segment xenogenic bone; It is easy and practicable in vector converting of medical image information with this method, and it also has good application prospect in biomanufacturing field in orthopaedic and oral maxillofacial surgery.

BACKGROUND:Tumor recurrence results from the incomplete removal of cancer stem cel s with self-renewal characteristics, and then how to label and eliminate cancer stem cel s becomes the key to cancer treatment. OBJECTIVE:To observe the morphology,distribution and number of CD44+/C-myc+METHODS:Pathological tissues from 150 patients with colorectal cancer were taken to prepare tissue microarray, in order to observe and count CD44 cel s in colorectal cancer, and to explore the relationship between the expression and postoperative metastasis.+/C-myc+cel s by using immunohistochemical double staining. Patients were fol owed up through mobile phones , letters , and so on, and the relationship between the expression of CD44+/C-myc+cel s and postoperative metastasis were statistical y recorded.RESULTS AND CONCLUSION:There was no CD44+/C-myc+cel s in normal tissue and little in adenoma. A smal number of CD44+/C-myc+cel s distributed as dots or focal lesions in adenocarcinoma. The number of CD44+/C-myc+cel s was related to the degree of adenocarcinoma differentiation, depth of invasion, and lymph node metastasis (P<0.05). The univariate analysis showed that the overal survival rate and progression-free survival rate were associated with the number of CD44+/C-myc+cel s, lymph node metastasis and Ducks staging in adenocarcinoma (P<0.05). The multivariate analysis showed that the overal survival rate was related to CD44+/C-myc+cel amount and the progression-free survival rate was related to CD44+/C-myc+cel amount and the Ducks staging. Therefore, CD44+/C-myc+cel s are probably cancer stem cel s, and Ducks staging and CD44+/C-myc+cel amount are important prognostic factors for colorectal cancer.

Objective To control residual DNA by optimizing methodology during the production of rabies vaccine using Vero cells as a vector .Methods The antigen recovery rate was assessed by linked immunosorbent assay-sandwich technique while the residual DNA was detected by DNA probe hybridization method .Antigen recovery and removal of DNA were the main indexes for evaluateing ultrafiltration , the vital part of rabies vaccine production .Three key factors in ultrafiltration were assessed: selection of membrane packages , ultrafiltration pressure and the concentration ratio .Then protamine was used to pretreat ultrafiltrates .Based on the two indicators mentioned above , the effect of protamine pretreat-ment on the ultrafiltrate was evaluated .Results and Conclusion The optimum condition of ultrafiltration was obtained on the basis of the general antigen recovery rate , DNA removal rate and actual production .The primary parameters of ultrafil-tration were as follows:7.5 ×105 ultrafiltration membrane packages, 20 times concentrated, 15 psi ultrafiltration pressure. After pretreatment with protamine , ultrafiltration has proved to be a molecular sieve in intercepting DNA ,while protamine can tangle the fragmented DNA and form a larger molecular segment , which is believed to be more conducive to ultrafiltra-tion interception .

Objective To evaluate the effectiveness of suberselective uterine arterial embolization for uterine fibroids.Methods Uterine arterial embolization with golyvimylalcohol(PVA) particles or Iodized oil and Gelfoam or Pingyangmycin lipiodol and Gelfoam was performed in 182 patients with uterine fibroids.Results Bilateral and unilateral superselective uterine arterial embolization were performed in 173 cases and 9 cases respectively. 6～28 months (mean 11 months) after the procedure, complete disappearance of tumor(16 cases), an average shinkage of 67% in tumor volume(152 cases) and a mean 42% reduction of uterine volume were obtained in 168 followed-up cases. The clinical symptoms were relieved significantly.The main side effets were hypogastic pain(135/182).Conclusion Superselection uterine arterial embolization is an effective and microinvasive method in treating uterine fibroids.