Osteoclast (OC) are bone resorbing cells whose development and activity are under the influence of osteoblast (OB). The potential association between those two cell lineages is an area of significant interest. It was not until 1998 that osteoclast differentiation factor (ODF) and osteoprotegerin (OPG) was cloned. The two novel TNF superfamily members have been recently demonstrate to be the key extracellular regulators of osteoclasteogenesis and bone resorption both in vivo and in vitro, and they play important roles in osteoporosis development, diagnosis and treatment.

Articular cartilage repair is one of the most challenging issues which remains to be resolved in clinic work. Discovering of bone marrow stromal cells (BMSC) and its application in tissue engineering provide new methods for the treatment of cartilage defects. High seeding density, appropriate cytokines and three-dimensional culture play important roles in the process of inducing BMSC differentiating into chondrocytes, suitable scaffold is also essential in reconstructing cartilage in vitro by methods of tissue engineering.

We analyzed the minus of present medical education,basing on questionnaires of 1773 medical students,including the students' participation rates in lectures of multiple fields and their demands on future lectures.We gave some pieces of advice to solve the problems as well as some references to boost our lectures.

AIM: To investigate the differentiation of human bone marrow mesenchymal stem cells (MSC) into chondrocytes in vitro and determine factors involving in the differentiation process. METHODS: MSC were separated from iliac bone marrow with lymphocyte separating medium using density centrifugation. Cells were cultured and expanded in medium until reaching required number. MSC was induced to differentiate into chondrocytes by adopting high cell density, supplying growth factor and using micromass culture. Cells were observed by HE staining. Matrix of cartilage was detected by alcian blue and toludine blue and cartilage specific collagen II was detected by immunohistochemistry. RESULTS: The structure of the micromass assumed that of cellular cartilage, alcian blue staining were uniformly positive and toludine blue detected diffuse metachromasia substance, cells uniformly expressed collagen Ⅱ. CONCLUSION: High cell density, growth factor and appropriate culture conditions are critical to induce differentiation of MSC into chondrocytes. [

AIM: To explore the pathophysiological mechanism of postmenopausal osteoporosis, we established an animal model for postmenopausal osteoporosis and investigated the loss of bone mass.METHODS: Thirty-one female SD rats (three months old) were randomly divided into two groups: sixteen ovariectomized (OVX) and fifteen sham-operated group as control. At post-operated day 28, seven rats of either OVX group or sham-operated group were sacrificed. At post-operated day 56, the rest of either were sacrificed. The wet weight of the uteruses were measured and the changes of bone micro-architecture were studied by bone mineral density (BMD) and the data of bone histomorphometry. RESULTS: Compared with the sham group, the mean wet weight and the bone density of proximal tibia 1/3 section of the OVX group was significantly decreased (P

Pathology rotation is an important part in resident standardization training. Impor-tance should be attached to the residents' learning during the standardization training in Pathology De-partment, such as standardizing training and strict departmental rotation examination, developing the residents' thinking ability of the relationship between clinical and pathology with the main line of spe-cialty pathology learning , and improving clinical research capacity through pathology technical methods and principles, and training pathology literacy from pathology requisition filled to interpreta-tion of the pathology report, which will also help to improve the medical service quality of the hospital.

BACKGROUND: Epidural block(EB) is one of the effective and widely used remedies for lumbar disc herniation(LDH) . Animal experiments have been conducted to study the changes in the local tissue structure in the spinal canel after several treatments with EB.OBJECTIVE: To study the effect of EB for LDH on the local tissue structures in the spinal canel.DESIGN: A non-randomized and controlled clinical observation.PARTICIPANTS: Department of Pathology and Laboratory of Electron Microscope of an Affiliated Hospital of a University.SUBJECTS: Forty patients with LDP, who failed to respond to EB treatment and subsequently received discectomy in the Department of Orthopaedics,First Affiliated Hospital of Sun Yat-sen University from May 1992 to December 1997, were enrolled in this study, with 20 patients receiving discectomy but not EB treatment serving as the control group.METHODS: From the 60 cases, totally 120 specimens of yellow ligament and the disc tissues were obtained during discectomy for optical microscopical examination. A portion of the yellow ligament and the lumbar disc tissues were chosen from EB group(12 cases) and non-EB group(10 cases), respectively, for electron microscope examination(involving altogether 44specimens) . The changes in histology and ultrastructnres in the specimens were compared between the two groups.MAIN OUTCOME MEASURES: ① Main results: the reactive proliferation of the tunica adventitia and inflammatory reaction of the intervertebral disc and yellow ligament; ② Secondary results: changes in the ultrastructure of the anulus fibrosus, nucleus pulposus and yellow ligament.RESULTS: No significant difference was found between the two groups either in light microscopy or electron microscopy in the degree of smoothness and the inflammatory reaction of the cavosurface of the yellow ligament and the disc tissues, nor in the cellular ultrastructures and fibrous arrangement.CONCLUSION: There is no direct relationship between lumbar EB and epidural scar adhesion formation. EB does not affect the ultrastructures of the local tissues in the spinal canal, but care must be taken of the sterilization in the surgical procedure, as chronic inflammatory reaction in the yellow ligament and disc tissues can be present in some patients.

OBJECTIVE:To study the inhibitory effects of propolis on growth of transplantation tumor in mice.METHO_ DS:Using different concentrations of propolis to feed the mice for two months,the tumor cells(S 180 )were transplanted into subaxillary tissue of the mice.After8days,the tumor mass was takent off the body of the mice,and weighted,then paraffin sections were observed and the number of karyokinesis of tumor cells was counted under the microscops.RESULTS:The weight of tumor mass were lighter in the propolis group than in the control group(P

Objective To describe MR findings in inflammatory myofibroblastic tumor(IMT)of the soft tissue.Methods MR manifestations of 11 cases of IMT of the soft tissue were retrospectively analyzed,and the MR findings were correlated with surgical and histological results.Results The pathological classification of the tumors was type Ⅰ in 1 case,type Ⅱ in 4 cases.mainly type Ⅱ admixed with type Ⅰ in 3 cases,and mainly type Ⅱ admixed with type Ⅲ in 3 cases.In 4 cases with primary tumor,the tumors were spheroid in shape,with well-defined margin and pseudocapsule.In 2 cases with primary axillary tumor and 5 cases with recurrent tumor,the tumors were irregular in shape,with ill-defined margin and invasion of adjacent structures.The tumors were mainly isointensive in T1-weighted images.Tumors of different pathological classifications had different signal intensities in T2-weighted images:1 case of type Ⅰ tumor was bright:4 cases of type Ⅱ tumor and 3 cases of type Ⅱ tumor admixed with type Ⅰ tumor were slig}ltly bright;3 cases of type Ⅱ tumor admixed with type Ⅲ were isointense or slightly hypointense in signal.All of the 11 eases in the study exhibited"pitaya cross-section sign"in T2-weighted sequence,which referred to discrete punctuate foci of relatively hypointensity in the background of hyperintensity,slightly hypointensity or isointensity.All of the 11 cases exhibited inhomogeneously significant enhancement after gadolinium administration.In the follow-up of the 6 cases of primary tumor,4 cases had recurrence,1 case had no recurrence,and 1 ease was lost in the follow-up process.In the follow-up of the 5 cases of recurrent tumor,4 cases showed recurrence again,and 3 cases were lost in the follow-up process.Conclusions The IMT of the soft tissue has characteristic MR features.The signal intensity of the tumor on T2-weighted sequence could reflect the pathological type of the tumor to some extent."pitaya cross-section sign"could be a pathogenomic sign of the IMT of the soft tissue.

Metformin, as a traditional oral hypoglycemic agent, is commonly used in the clinical treatment for type 2 diabetes. Recently, a large number of epidemiological researches have shown that metformin could reduce the tumor morbidity of type 2 diabetes, moreover, it has also been indicated that metformin could inhibit the growth, proliferation and transformation of cancer cells in metabolic pathways, cell cycle, oxidative stress and cancer/tumor stem cells transformation via AMPK pathway activation. But the antitumor effect of metformin via AMPK activation still exists arguments, and the deifnite mechanism remains to be further investigated and conifrmed by extensive clinical trials.