Objective To understand willingness of current medical undergraduates to work at community health-care service(CHS)institutions after their graduation to provides information for professional training for them.Methods Totally,2714 medical undergraduate students were recruited from three medical schools in east,middle and west China by multi-level sampling methods for questionnaire survey on their basic information and willingness to be employed at CHS institutions.results of the survey were described by relative numeric and tested by chi-square test for smtistical inference.Results About 60.6%of medical undergraduate students were willing to work at CHS organizations permanently or temporarily.Their willingness to work there differed with their native living areas and grades they were studying significantly(P＜0.01).Reason for those they would work at CHS organizations after graduation included work less stress and easier,and that for those reluctant to work there included low-income and lack of social respect for general practitioners.Conclusions Nowadays,few medical undergraduate students would like to work at CHS organizations after their graduation,which was influenced mainly by traditional ideas and concepts of employment,personal career devdopment,economic income,and so on.It is suggested that ideas of community work be strengthened for medical undergraduate students and their employment concepts be changed in the future.

Objective To observe the effect of Ti-6AL-4V particles on morphological and func- tional changes of osteoclast in vitro.Methods Mature osteoclasts separated from New Zealand Rabbits were cultured on glass slices and cortical bone slices.The experimental group was stimulated by Ti-6AL- 4V particles at concentration of 0.1 mg/ml.The cells were stained with TRAP at different culture time to observe the morphological variety.The bone resorption pits on bone slices were stained by toluidine blue and the resorption areas analyzed by computer image analysis software.Results Osteoclasts phagocy- tosed the particles,with irregular shapes,deeper TRAP stain and earlier apoptosis.Stimulation by Ti- 6AL-4V particles brought about larger area of bone absorption lacuna.Conclusion Osteoclasts have the ability to phagocytose Ti-6AL-4V particles,which leads to morphological and functional changes and enhances bone resorption.

Objective To localize the sinoatrial node (SAN) of the newborn rabbits in vivo and cut it for purifying cultivation and study the morophologic characters of primary cultured pacemaker cells of SAN under light microscope and transmissional electron microscope. Methods Hearts of the newborn rabbits were embedded in paraffin for HE-staining and observed the location, form of SAN under optical microscope; SAN cells isolated from neonatal rabbits cultured and purified with the method of differential attachment and BrdU-treatment.Results SAN localized in the anterior wall of the superior vena cava and the posterior-lateral atrial wall.There was about 0.32 mm between its lowest point and sulcus terminalis. Three distinctly different types of cells were observed among the cultured cells of SAN: spindle, araneiform and polygon. The spindle cells covered the greatest proportion of the cultured cells of SAN (59.6%?7.3%). The frequency of spontaneous contraction of spindle cells was the highest among the constrcting cells (145 ?9)time/min. The results of ultrastructure observation showed that myofibrils and other organelles in spindle cells were poorly organized and significantly decreased in number compared with araneiform cells. There was no significant difference between araneiform cells isolated from SAN and from atrial muscle.Conclusion Among the cultured cells from neonatal rabbits SAN, the spindle cells are the pacemaker cells of SAN.

Ectopic ACTH syndrome caused by adrenal pheochromocytoma is very rare.A case was herewith reported and the domestic and foreign literatures were reviewed.The correct diagnosis of the syndrome depends on clinical,biochemical,hormonal,radiographic,pathological investigations,as well as tumor immunohistochemistry for final comprehensive judgments.

OBJECTIVETo assess the reliability and validity of the Aging Males' Symptoms (AMS) scale in the male population of Shanghai.

METHODSWe enrolled 973 males aged 40 years and over in a community of Shanghai, China. Using the AMS scale, we calculated the split-half reliability coefficient and Cronbach's alpha coefficient, assessed the validity through confirmatory factor analysis and correlation analysis, and obtained the domain scores of different people by analysis of variance and independent sample test.

RESULTSThe split-half reliability was > 0.78 (P < 0.01) and Cronbach's alpha coefficients of all the dimensions > 0.82 (P < 0.01). Confirmatory factor analysis showed 3 domains in the AMS scale, Pearson correlation coefficients of all the items to their domains were > 0.49 (P < 0.01), and the total testosterone level was not correlated with AMS scores, with Pearson correlation coefficient of -0.04 (P > 0.05). Statistically significant differences were found in AMS scores among different age groups as well as among those with different chronic disease histories, but not in the psychological domain among different age groups.

CONCLUSIONThe reliability and validity of the AMS scale are acceptable in assessing aging males'symptoms among the male population of Shanghai, but further studies are needed to determine whether it could be used as a tool for screening late-onset hypogonadism (LOH) in males.

Adult ; Aged ; Aging ; China ; epidemiology ; Humans ; Hypogonadism ; epidemiology ; psychology ; Male ; Middle Aged ; Psychometrics ; Reproducibility of Results ; Surveys and Questionnaires

BACKGROUNDWhile attempting to restore bone stock, impaction bone grafting employed during revision joint surgery may result in slow and limited allograft incorporation into host bone. A new approach including gene-modified bone marrow stromal cells (BMSCs) in combination with impaction bone grafting may effectively restore bone stock and improve allograft incorporation. This study aimed to investigate the effect of impaction on gene-modified BMSCs seeded on granular bone allografts in vitro and in vivo.

METHODSDeep-frozen, granular, cancellous bone allografts from canines were prepared to serve as cell delivery scaffolds and were seeded with green fluorescent protein (GFP) genetically-modified BMSCs to construct cell-allograft composites. The composites were impacted in a simulative, in vitro impaction model and cultured for further analysis under standard conditions. Four Beagle dogs, treated with bilateral, uncemented proximal tibial joint hemiarthroplasty with a prosthesis, were implanted with autologous GFP gene-modified cell-allograft composites to repair the bone cavity around each prosthesis.

RESULTSA significant reduction in cell viability was observed after impaction by fluorescence microscopy in vitro. However, there remained a proportion of GFP-positive cells that were viable and functionally active, as evidenced by the secretion of GFP protein in vitro and in vivo.

CONCLUSIONSGene-modified BMSCs seeded on granular allografts were able to withstand the impaction forces and to maintain their normal functions in vitro and in vivo, in spite of a partial loss in cell viability.

Animals ; Bone Marrow Cells ; cytology ; Bone Transplantation ; methods ; Cell Survival ; physiology ; Cells, Cultured ; Dogs ; Male ; Microscopy, Fluorescence ; Stem Cells ; cytology ; Stromal Cells ; cytology ; Transplantation, Homologous

OBJECTIVETo compare the effect between mini-traumatic bone-grafting and non-bone-grafting in percutaneous K-wire fixation for treating the calcaneal fractures.

METHODSFrom 2002 to 2006, 112 patients with the type II (Paley type) fractures of calcaneus were studied. There were 56 cases in bone-grafting group involving 36 males and 20 famales,aged from 21 to 65, averaged (42.0 +/- 2.3) years; 11 cases were in type II a and 45 were in type II b; the course was from 3 to 14 days, averaged (6.0 +/- 1.2) days. And there were 56 cases in non-bone-grafting group involving 38 males and 18 famales,aged from 22 to 67, averaged (43.0 +/- 2.5)years; 13 cases were in type II a and 43 were in type II b; the course was from 2 to 15 days, averaged (5.0-2.1) days. All the cases were treated by closed reduction and percutaneous K-wire fixation, and bone-grafting group(56 cases) were treated by mini-traumatic bone-grafting, but the other group (56 cases) were not. The collapsing rate and fineness rate were compared.

RESULTSAll the cases were followed up from 5 to 52 months. There were no collapsing cases in the bone-grafting group after operation, but 3 cases occurrenced re-collapsing in the non-bone-grafting group. According to the Zhang Tie-liang's evaluation criterion, in the bone-grafting group,the results were excellent in 43 cases, good in 12, fair in 1, the fineness rate was 98.2%. In the non-bone-grafting group,the results were excellent in 37 cases, good in 16, fair in 2, poor in 1, the fineness rate was 94.7%.

CONCLUSIONTreatment of the type II fracture of calcaneus with closed reduction, percutaneous K-wire fixation and mini-traumatic bone-grafting can prevent the posterior talar articular surface of caltaneus from collapsing again after operation, enhance the union of fracture, elevate the curative effect, thus it should be taken with the standard therapeutic regimen.

Adult ; Aged ; Bone Transplantation ; methods ; Bone Wires ; Calcaneus ; injuries ; surgery ; Female ; Follow-Up Studies ; Fracture Fixation, Internal ; Fractures, Bone ; surgery ; Humans ; Male ; Middle Aged ; Transplantation, Autologous ; Treatment Outcome ; Young Adult

OBJECTIVETo investigate the features of circulating plasmacytoid dendritic cells (pDCs) in patients with chronic hepatitis B for a better understanding of the immunopathogenesis of HBV infection.

METHODSFresh blood samples were collected from 20 patients with chronic hepatitis B (CHB) and from 15 healthy individuals who served as controls. pDCs were isolated from peripheral blood mononuclear cells (PBMCs) using immunomagnetic assay and detected by flow cytometry. Fresh PBMCs and isolated pDCs were stimulated in vitro using CpG ODN2216. The supernatants were measured for IFNa production using ELISA.

RESULTSThe peripheral pDCs frequency in CHB patients (0.192%+/-0.110%) was markedly lower than that in the healthy controls (0.287%+/-0.142%). After being pulsed with CpG ODN2216, the isolated pDCs produced lower levels of IFNa and expressed lower levels of CD80 and CD40 in the CHB patients when compared to those of the healthy controls. The level of IFNa was (972.6+/-705.5) pg/ml in the patients and (3 142.9+/-1 292.2) pg/ml in the controls. Moreover, the pDCs frequency was reversely correlated with serum ALT levels in these HBV infected patients.

CONCLUSIONThe reduced number and impaired function of circulating pDCs in patients with CHB may be related to their disease progression.

Adult ; Case-Control Studies ; Cells, Cultured ; Dendritic Cells ; cytology ; metabolism ; Female ; Flow Cytometry ; Hepatitis B, Chronic ; blood ; immunology ; Humans ; Interferon-alpha ; biosynthesis ; Male ; Middle Aged ; Oligodeoxyribonucleotides ; pharmacology

OBJECTIVETo compare the ability of three different reconstruction procedures in restoring the posterior displacement of tibia and the posterior stability of the knee joint from 0 degree to 120 degrees flexion.

METHODSThree posterior cruciate ligaments (PCL) reconstruction procedures were performed, namely two-band two-tunnel reconstruction, one-band anterior tunnel reconstruction and one-band posterior tunnel reconstruction. The posterior displacement of the tibia in relation to the femur was measured when a 200N posterior force was applied.

RESULTSWithin the flexion range of 0 degree to 30 degrees, the displacement in the one-band posterior tunnel reconstruction showed little difference from that of an intact knee (P>0.05). But when the flexion exceeded 30 degrees, especially when it exceeded 60 degrees, the displacement in one-band posterior tunnel reconstruction was much greater than that of an intact knee (P<0.01). In two-band two-tunnel reconstruction and one-band anterior tunnel reconstruction, the displacement was approximately the same as that of an intact knee ranging from 0 degree to 120 degrees (P>0.05), while a slight over-restriction might be found at some angles.

CONCLUSIONSTwo-band reconstruction could effectively restrict the posterior displacement of the tibia and restore anterior, posterior stability of the knee joint within its full range of flexion. One-band anterior tunnel reconstruction also could maintain the posterior stability of the knee, while the result of one-band posterior tunnel reconstruction is the most unsatisfactory.

Adult ; Biomechanical Phenomena ; Cadaver ; Humans ; Joint Instability ; surgery ; Knee Joint ; physiopathology ; Male ; Middle Aged ; Orthopedic Procedures ; Posterior Cruciate Ligament ; surgery ; Postoperative Period ; Range of Motion, Articular

OBJECTIVETo study the effect of ultra high molecular weight polyethylene (UHMWPE) particles on macrophages and evaluate the expression of NFAT2, a key transcriptional factor for osteoclast differentiation.

METHODSFrom November 2004 to February 2005, macrophages were co-cultured with UHMWPE particles. When observed at different times, the proliferation activity of macrophages was analyzed by MTT and the expression of calcineurin (CaN) and NFAT2 by immunohistochemical and RT-PCR method respectively.

RESULTSThe macrophages phagocytosed UHMWPE particles in an early time, the expression of CaN and NFAT2 was increased, while the proliferation activity was not enhanced.

CONCLUSIONSUHMWPE particles can stimulate macrophages to phagocytose significantly, and enhance the expression of the transcriptional factor NFAT2.

Animals ; In Vitro Techniques ; Joint Prosthesis ; Macrophages ; drug effects ; physiology ; Mice ; NFATC Transcription Factors ; biosynthesis ; genetics ; Phagocytosis ; drug effects ; Polyethylenes ; pharmacology ; RNA, Messenger ; genetics