Hydrostatic pressure induces apoptosis of chondrocytes cultured in alginate beads.

The purpose of this study was to investigate the influence of hydrostatic pressure (HP) on apoptosis and expression of heat-shock protein 70 (HSP70) in chondrocytes cultured in alginate beads. Chondrocytes were isolated from the articular cartilage of rabbit joints and seeded in alginate beads. The beads in Group A were cultured for less than 24 h after being embedded with the chondrocytes, while those in Group B were cultured for 2 weeks. Both groups were exposed to HP of 10 or 50 MPa for 12 or 24 h. The beads in Groups A and B that were not exposed to HP were regarded as controls. Apoptotic cells induced by exposure to HP were quantified using the TUNEL method. Immunohistochemical analysis for HSP70 and in situ TUNEL analysis were also performed. Apoptotic chondrocytes were not observed in the control cells under atmospheric pressure, whereas apoptosis was observed in the beads in Group A, and the number of apoptotic cells increased as the duration and magnitude of HP increased. On the other hand, we observed no significant population of apoptotic cells in the beads in Group B. Chondrocytes expressing HSP70 were not TUNEL positive in the histological analysis. Excessively strong HP could evoke apoptosis when the extracellular matrix did not accumulate around the chondrocytes. HSP70 expression was related to occurrence of apoptosis that resulted from HP. These findings suggest a mechanism for the pathogenesis of cartilage degeneration in osteoarthritis.     

Differences in ABO antibody levels among blood donors: a comparison between past and present Japanese, Laotian, and Thai populations

Passively transfused blood group antibodies cause clinical problems. High titers of anti-A and anti-B seem to be one reason for hemolytic transfusion reactions and for ABO HDN. In Japan, anti-A and anti-B titers notably decreased in the 15 years between 1986 and 2001. At present, titers of more than 100,as measured using the saline method, are rare. Differences in the level of anti-A and anti-B among ethnic populations have been reported; these differences were found to be the result of environmental factors rather than hereditary factors. In the present study, the anti-A and anti-B titers of random donors in three Asian populations are compared. In Thailand, the IgM anti-A and anti-B titers are low and are similar to the Japanese titers reported in 2001, but the IgG anti-A and anti-B titers are high and are similar to the Japanese titers reported in 1986. In the Lao People's Democratic Republic, both the IgM and the IgG anti-A and anti-B titers are high and are similar to those reported in Japan in 1986. In addition, anti-A and anti-B titers of different sex donors and of various age groups were also compared. High titers were found in 8.8 percent of the female donors in the younger than 30 age group and in 36.7 percent of the female donors in the older than 50 age group.     

Primary telangiectatic osteosarcoma of the cervical spine

Telangiectatic osteosarcoma (TOS) is one of the 8 subtypes of osteosarcoma that infrequently affects the spine. The radiopathological features of TOS overlap with those of more benign entities, most commonly the aneurysmal bone cyst), and therefore is a significant diagnostic challenge. It is a rare but well-described entity in the thoracolumbar and sacral spine, and to the authors' knowledge has not been previously reported in the cervical spine. The authors report the case of a 15-year-old boy who presented with a 6-month history of neck pain and torticollis. He underwent preoperative glue embolization followed by a staged subtotal C-5 spondylectomy and posterior fusion for a C-5 vertebral body lytic expansile lesion. Histopathological examination showed the lesion to be TOS. The surgery was followed by adjuvant radiation and chemotherapy with a favorable outcome at the 1-year follow-up. This report reiterates that TOS is an important differential diagnosis for aneurysmal bone cyst and giant-cell tumor of the spine, as its biological behavior and clinical outcome differ from those of these more benign lesions, which it mimics.     

Biomarkers of oxidative stress and risk of developing colorectal cancer: a cohort-nested case-control study in the European Prospective Investigation Into Cancer and Nutrition

Oxidative stress has been shown to play an important role in carcinogenesis, but prospective evidence for an association between biomarkers of oxidative stress and colorectal cancer (CRC) risk is limited. The authors investigated the association between prediagnostic serum levels of oxidative stress indicators (i.e., reactive oxygen metabolites (ROM) and ferric reducing ability of plasma (FRAP)) and CRC risk. This was examined in a nested case-control study (1,064 CRC cases, 1,064 matched controls) in the European Prospective Investigation Into Cancer and Nutrition cohort (1992-2003). Incidence rate ratios and 95% confidence intervals were calculated using conditional logistic regression analyses. ROM were associated with overall CRC risk (highest tertile vs. lowest: adjusted incidence rate ratio (IRR(adj)) = 1.91, 95% confidence interval (CI): 1.47, 2.48), proximal (IRR(adj) = 1.89, 95% CI: 1.06, 3.36) and distal (IRR(adj) = 2.31, 95% CI: 1.37, 3.89) colon cancer, and rectal cancer (IRR(adj) = 1.69, 95% CI: 1.05, 2.72). When results were stratified by tertile of follow-up time, the association remained significant only in participants with less than 2.63 years of follow-up (IRR(adj) = 2.28, 95% CI: 1.78, 2.94; P-heterogeneity < 0.01). FRAP was not associated with CRC risk. In conclusion, prediagnostic serum ROM levels were associated with increased risk of CRC. However, this association was seen only in subjects with relatively short follow-up, suggesting that the association results from production of reactive oxygen species by preclinical tumors.     

The effect of apoptosis signal-regulating kinase 1 gene transfer on rat collagen induced arthritis

OBJECTIVE: To examine the apoptosis-inducing effect of apoptosis signal-regulating kinase 1 (ASK1) gene transfer into synovial cells in vitro and in vivo. METHODS: An adenovirus vector was constructed so that a constitutively active form of ASK1 gene (ASK1DeltaN) was expressed in the presence of the Cre recombinase. The ASK1DeltaN and Cre adenovirus vectors were cotransduced into cultured synoviocytes derived from patients with rheumatoid arthritis (RA), and apoptosis was evaluated by TUNEL and Hoechst staining. Collagen induced arthritis (CIA) was induced in 8-week-old male DA rats, and 10 days later the 2 adenovirus vectors were coadministered into the ankle joints of the animals. As indicators of severity of arthritis, swelling of the ankle and articular index (AI) scores were evaluated, while histopathological observation of articular tissue was also performed. RESULTS: In the cultured human RA synoviocytes, overexpression of the ASK1DeltaN significantly reduced cell viability and induced apoptosis. In the CIA rats transduced with the ASK1DeltaN gene, arthritis was significantly promoted in terms of the swelling of the ankle joints and elevation of the AI scores. Histopathological observation also revealed that the constitutively active ASK1 induced massive infiltration of inflammatory cells into the synovial membrane as well as proliferation of synovial fibroblasts. Degeneration of the synovial membrane was not evident. CONCLUSION: Adenoviral transduction of ASK1DeltaN induced apoptosis in RA synoviocytes in vitro, but not in CIA synovium in vivo.     

Gene delivery to human chondrocytes by an adeno associated virus vector

OBJECTIVE: To investigate the efficiency of gene transduction to human chondrocytes using an adeno associated virus (AAV) vector. METHODS: We transduced green fluorescent protein (GFP) gene using AAV vector to primary human chondrocytes as well as human cartilage organ cultures, in which chondrocytes are surrounded by extracellular matrix. Expression of GFP gene was analyzed at various time points after transduction by fluorescence microscopy and immunohistochemistry. RESULTS: In primary chondrocytes, the percentages of GFP positive cells were 15.9% or 16.0% on Day 1 and 95.0% or 93.7% on Day 7 after gene transduction. In cartilage organ cultures, gene delivery was observed in cells located not only in the superficial layer but also in the deep layer within the cartilage tissue. Up to 45.3+/-7.4% or 46.0+/-3.9% of chondrocytes expressed GFP for at least 28 days. CONCLUSION: AAV vector could be useful for direct gene delivery to chondrocytes in situ.     

Abrogation of the Allelic Exclusion in a T Cell Receptor β Chain Gene Transgenic Mouse Strain

The expression of endogenous T cell receptor (TcR) β chains in a TcR β chain gene transgenic mouse (TGM) strain was examined. Unlike many other TGM strains reported, a considerable proportion of T cells from the thymus and spleen as well as organ cultured fetal thymus from our TGM express endogenous TCR β chains on their surface. Compatible with this was the elucidation of VDJ rearrangement of endogenous β chain genes by PCR. Three color flowcytometric analysis of thymus cell subpopulations revealed that the expression levels of both endogenous and transgenic TcR β genes are regulated in a maturational stage specific manner. Splenic T cells contained a several fold higher percentage of endogenous TcR β positive cells than thymus cells, suggesting a role of TcR on T cell peripherization. Vβ6 positive cells were deleted in the TGM carrying minor lymphocyte stimulating (Mls)-l^a antigen, indicating that the endogenous TcR β is functional in terms of transmiting a signal for clonal deletion.