Eight specimens of the knee were used to determine quadriceps force (FQ) required to stabilize the knee under load in a flexed stance.It was found that there was a positive relationship between quadriceps force and the weight and flexion of the knee .At flexion of 15? FQ was about the same as the weight; at 45?,about 3-4 times the weight.FQ increased by 10-40% after patele ctomy, while anterior displacement of the tibial tubercle by 1.5cm led to 11%-19% decrease because of its pro- longed lever arm. It widened the angle formed by the qudriceps tendon and the patellar tendon by an average of 10.7 degrees.The contact areas of the patellofemoral joint at flexion of 0-135 ? were determined by contact prints.Following anterior displacement of the tibial turbercle, contact areas were upwardly shifted and enlarged.Our results show that this procedure can decrease the patellofemoral contact stress by lengthening the lever arm of FQ, widening the angle formed by the guad-riceps tendon and patellar tendon and enlarging contact areas of the patellofemoral joint. We recommend it as a possible satisfactory treatment for the patellofemoral joint disorders

Objective This is a feasibility study of rabbit meniscus regeneration evaluated with the use of autologous bone marrow derived mesenchymal stem cells(MSCs) and collagen glycosaminoglycan(GAG). Methods Autologous MSCs were prepared from the rabbit proximal tibial bone marrow and stimulated in vitro to start fibrocartilage differentiation lineage by bFGF and TGF ? 1. Then, collagen GAG templates enriched with these MSCs were implanted in vivo to the menisci excised rabbit knees as the substitute for the excised meniscus. After 3, 6, 12, 24 weeks postoperatively, the implants were evaluated by the gross, histological and ultrastructural observations. Results The MSCs enriched collagen GAG implants underwent inflammation, degradation, MSCs division and remodeling stages in vivo, and consequently formed a meniscus like fibrocartilage tissue. Special staining and electronic microscope observation proved that the regenerated fibrocartilage were chondrocyte like fibrochondrocytes; in contrast, the results of the control group showed that both collagen GAG implants without MSCs and no substitute had limited regenerating tissue, further evaluations by histological and electronic microscope showed no evidence of fibrochondrocytes, and hence these regenerated tissue were fibrous rather than fibrocartilaginous. Conclusion The inducing of rabbit meniscus regeneration by the autologous bone marrow derived MSCs and porous collagen GAG template is proved to be feasible in this study. However, further studies to improve the biomaterial design, to evaluate the biomechanical properties of the regenerated tissue and to ensure clinical safety etc are needed prior to its clinical application.

Objective To study surgical therapy of the serious medial collateral ligament ruptures of the knee. Methods 12 patients with acute medial collateral ligament ruptures were treated operatively.Their degrees of injury were all Ⅲdegree that superficial and deep collateral ligaments were completely ruptured.Some of them were accompanied with the injury of medial joint capsule ligament or anterior cruciate ligament or posterior cruciate ligament.The torn medial collateral ligaments were anatomically corrected by their ends with direct suture or staple internal fixation.They were followed 6 to 18 months. Results 12 patients were graded with the Lysholm score .The postoperative score (mean, 76; range, 59 to 90) was higher compared with the preoperative score (mean, 35; range, 20 to 54), P

The laboratory accreditation plan is an effective way to realize the standardization of medical laboratories.The test method validation is required by ISO 15189 guideline and CAP checklists.However,after CBC analyzers and coagulation analyzers are repaired,no solution for the validation is put forward.

Objective: To synthesize the collagen-GAG template and to evaluate its feasibility to be used as the MSCs vehicle for meniscal tissue engineering. Methods: The collagen-GAG template was synthesized from rat tail type Ⅰ collagen and GAG using Yannas method. Then the post-stimulated MSCs by bFGF and TGF-β1 were added in. The MSCs-enriched collagen sponges were cultured in vitro， two weeks later the histological and ultrastructure detection was performed. Results: The histological and ultrastructure of the collagen-GAG template remained intact after 2 weeks' culture, and the MSCs in it remained viable. Conclusion: The collagen-GAG template synthesized in this experiment is suitable for the meniscal tissue engineering reconstruction as the vehicle for MSCs seed cells.

Risk management is derived from industry.In recent years,risk management is introduced by many medical laboratories their process management abroad.However,the concept of risk management is still very new for laboratories in China.Therefore,the establishment of the project for risk detection,classification,correction,prevention and supervision could help medical laboratories improve their service quality.

Objective To introduce and evaluate the surgical reconstrutive technique for acetabular wear after artificial femoral head replacement. Methods Sixty patients with 60 painful hips after artificial femoral head replacements undergone revision hip arthroplasty were analysed.The most essential problem causing hip pain was mechanical wear in acetabulum(71％ ).The acetabular wear could be divided into 0－Ⅲ degrees,which could be reconstructed with regular acetabular preparation, impact of morselized bone graft and structural bone graft. The mean follow up period was 4.1 years (ranged from 12 months to 11 years). Results Based on Merle D'Aubigne evalvation system,50 patients (83％ ) had excellent results, 8 patients good or fair,1 case needed re- revision for septic hip, the other 2 hips had radiolucent lines around acetabular cup, but no clinical loosening. Conclusion The classification of acetabular wear allowed determinant of a certain option about soft tissue release,greater trochanter osteotomy or reconstruction of acetabulum during revision surgery. Impaction of morselized bone graft in reconstruction of acetabulum represented an attractive revision option. It also suggests that total hip arthroplasty or bipolar prosthesis may be superior to femoral head replacement for patients with femoral neck fracture.

Objective To investigate the infection status of human parvovirus B19(HPV B19) in voluntary blood donors of Fos‐han City .Methods The HPV B19 IgG and IgM antibodies of voluntary blood donors were detectd by using ELISA .Real‐time PCR assay was applied to detect HPV B19 DNA on HPV B19 IgG and/or IgM antibody positive specimens .Results There were 92 HPV B19 IgG positive cases in 368 specimens ,positive rate was 25 .00% ;and the HPV B19 IgM positive cases were 2 ,positive rate was 0 .54% .4 positive cases were detected in 94 antibody positive specimens ,positive rate was 4 .26% .Conclusion HPV B19 in‐fection of blood donation person in Foshan is high ,new infections and chronic infection rate are low .HPV B19 viral loads are low in people with chronic infection .

Objective To study the impacts of variation of folate metabolic component including folic acid (FA), riboflavin (RF) and MTHFR C677T polymorphism on chromosome 8 and 17 segregation. Method RPMI1640 medium was modified with different combinations of low (LF) and high (HF) concentrations of folic acid (20, 200 nmol/L) and low (LR) and high (HR) concentrations of riboflavin (1 and 500 nmol/L). The lymphocytes with different MTFHR C677T genotype were cultured in the mentioned media for 9d. Cytokinesis was blocked by cytochalasin B and the slide was prepared as usual. The frequencies of aneuploidy of chromosomes 8 and 17 were determined by dual-color fluorescence in situ hybridization (FISH). Results The frequencies of both chromosome aneuploidy were significantly higher in low FA (LFLR+LFHR) than that in higher FA (HFLR+HFHR) (P

Abstract: Objective To compare the screening effects of RDT, microscopy and PCR for malaria among residents in low malaria areas and elimination areas, and to investigate the presence of malaria in residents of border Villages in Cangyuan Va County and asymptomatic infections in surrounding areas, providing a basis for preventing re-introduction of malaria after elimination. Methods From August 2020 to March 2021, the fingertip blood of the investigated subjects was collected from three survey sites in the border area between China and Myanmar, namely Banlao Township in Cangyuan Va Autonomous County of Lincang City, Banwai District, Mengmao County, the Second Special Zone of Shan State, Myanmar, Yongmo and Dayan Township, Nandeng Special Zone, the Second Special Zone of Shan State, Myanmar. The malaria parasite antigen detection test kit, malaria parasite microscopic examination, fluorescent quantitative PCR and nested PCR were used to detect the asymptomatic infection of malaria parasites. Results A total of 1 040 blood samples were collected, including 606 from China and 434 from Myanmar, with 506 males and 534 females. Among them, , there were 51 individuals aged 0 to <5 years, 283 aged 5 to < years, 187 aged 15 to < years, 232 aged 30 to <45 years, 205 aged 45 to < years, and 82 aged ≥60 years. All 1 040 people tested negative for plasmodium antigen detection kit. One case of Plasmodium vivax detected by plasmodium microscopic etiology, with a detection rate of 0.10%. One case of P. vivax was also detected by fluorescent quantitative PCR and nested PCR, with a detection rate of 0.10%. Among them, one case of P. vivax was detected in Banwai District, Mengmao County, the Second Special Zone of Shan State, Myanmar, with a detection rate of 0.35%. The detection rates of malaria parasites in Banlao Township in Cangyuan Va Autonomous County of Lincang City, Yunnan Province and Yongmo Township and Dayan Township, Nandeng Special District, the Second Special Zone of Shan State, Myanmar were both 0. The difference in the detection rate of malaria parasites among the three survey sites was not statistically significant (χ2 =2.682, P>0.05). The asymptomatic P. vivax infection was detected in a 6-year-old girl from Banwai District, Mengmao County, the Second Special Zone of Shan State, Myanmar. Conclusions RDT is not suitable for malaria screening in low malaria area and elimination area. Microscopic examination and PCR can be used for malaria screening, but PCR operation is complex and costly. In surrounding areas outside of China, malaria is still prevalent, while there is no source of malaria infection in border villages of Cangyuan Va County. However, there is a risk of importation, and timely and effective measures should be taken to prevent reintroduction and transmission.