Twenty clinical symptoms and four radiological signs of different joints in patients with Kashin-Beck disease (KBD) were studied in 2560 subjects from endemic and non-endemic areas of the Shaanxi Province in China. It is suggested to classify the symptoms into five groups representing different manifestations of the disease. The association of some of the symptoms appears to provide significant criteria for use in the diagnosis of KBD.

Objective To analyze the genetic polymorphism of 5 STR loci (D12S304, D12S313, D12S1583, D12S1640 and D12S1708) on chromosome 12 in Chinese Han population. Methods EDTA-anticoagulated blood specimens were collected from unrelated individuals of Chinese Han population in Shaanxi province. DNA samples were extracted with the Wizard Genomic DNA purification Kit and were amplified by polymerase chain reaction (PCR) technique. The PCR products were analyzed by ABI 3100 Genetic Analyzer. Results All 5 loci were in Hardy-Weinberg equilibrium. Allele and genotype frequencies, heterozygosity, power of discrimination, polymorphism information content, probability of paternity exclusion and matching probability of each locus were calculated in Excel 2002. Conclusion They are complexloci with lots of evenly distributed alleles and high heterozygosity in Chinese Han population. Thus they are informative polymorphicloci and valuable DNA marker which represents a superior alternative to many established STRs.

Objective. Kashin-Beck disease (KBD) is a chronic, endemic osteochondropathy principally occurring in children. We investigated apoptotic chondrocyte death and the expression of Bcl-2, Bax, Fas, and inducible nitric oxide synthase (iNOS) in articular cartilage from patients with KBD in order to determine the pathogenesis of chondronecrosis in KBD. Methods. Samples of articular cartilage were divided into 2 groups: control children (15 samples from 15 cases), and children with KBD (15 samples from 15 cases). KBD patients were diagnosed according to "Pathological Criteria to Diagnose KBD in China." Chondrocyte apoptosis was detected by TUNEL staining, and Bcl-2, Bax, Fas, and iNOS-positive articular chondrocytes were stained by immunohistochemistry. Articular cartilage was classified in 3 zones, and positive findings were counted by light microscopy for cytoplasmic staining by polyclonal antibodies of Bcl-2, Bax, Fas, and iNOS and apoptotic chondrocytes by TUNEL. Results. The percentage of positive apoptotic chondrocytes stained by TUNEL in the middle zone of articular cartilage from the KBD patient group (33.60% +/- 2.71%) was higher than that of controls (1.33% +/- 0.41%; p < 0.01). The percentages of chondrocytes staining for Bcl-2, Bax, Fas, and iNOS in KBD patients were significantly higher than in controls (p<0.01); the remarkable difference in Bcl-2, Bax, Fas, and iNOS expression among the upper, middle, and deep cartilage zones was also seen in KBD articular cartilage (p<0.01); and staining for Bcl-2, Bax, Fas, and iNOS in KBD patients was prominent in the upper zone (41.93% +/-12.26%, 45.60% +/-15.78%, 53.60% +/- 16.49%, 45.47% +/- 14.02%, respectively) and the middle zone (14.93% +/- 3.50%, 13.87% +/- 4.32%, 23.27% +/- 4.83%, 21.67% +/-6.82%) of articular cartilage. Conclusion. The apoptotic chondrocytes and Bcl-2, Bax, Fas, and iNOS-positive chondrocytes were significantly more numerous in patients with KBD than in controls.

To investigate the effect of excessive fluoride ingestion (EFI) on the differential expression of collagen phenotypes and chondrocyte differentiation in cartilage, 60 Sprague-Dawley rats, 4-6 weeks old, were divided into three groups and exposed to O (control), 50, and 100 ppm fluoride (from NaF) in drinking water for 3 to 5 months. Correlating with the increased F in the serum and bone in the two groups exposed to EFI, chondrocytes in the proliferative and hypertrophic zones of growth plate cartilage (GPC) and rib cartilage (RC) were retained and formed a mixture tissue of cartilage peninsulas or islands with ossified islands in the deep zone of GPC and RC. Staining reactions for types II and X collagen were increased in the over-thickened region of GPC and were decreased in RC. Type X collagen staining reactions were also increased in the upper and middle zones in articular cartilage (AC) of tibia in the higher fluoride (EFI-II) group. Abnormal collagen expression in rats of the EFI groups resulted from abnormal differentiation of chondrocytes in proliferative and hypertrophic zones in GPC and RC and from degenerative changes in AC of rats in the EFI groups. Four types of abnormal chondrocyte differentiation in hyaline cartilage of rats with skeletal fluorosis (SF) suggested two pathogenic mechanisms for early stage of SF: osteomalacia-like changes in GPC and RC coupled with delayed mineralization and degenerative changes in AC.