Monitoring recovery from iron deficiency using total hemoglobin mass.

INTRODUCTION: Using hemoglobin concentration ([Hb]) to diagnose borderline iron deficiency and monitor the progress of its treatment is difficult because of the confounding effects of plasma volume. Because hemoglobin mass (Hbmass) is not affected by plasma volume, it may be a more sensitive parameter. The aim of this study was to monitor Hbmass, iron storage, and maximal oxygen consumption (V˙O2max) during and after oral iron therapy in subjects with severe and moderate iron deficiency. METHODS: Three groups of female recreational athletes were monitored for at least 22 wk, as follows: 1) severe iron deficiency group (SID) (n = 8; ferritin, ≤12 ng·mL), 2) moderate iron deficiency group (MID) (n = 14; ferritin, ≤25 ng·mL), and 3) control group (n = 8; ferritin, >25 ng·mL). Hbmass and iron status were determined before, during, and up to 12 wk after at least 10 wk of oral iron supplementation. In total, five V˙O2max tests were performed before, during, and after the supplementation period. RESULTS: Hbmass increased markedly in the SID group (15.6% ± 11.0%, P < 0.001) and slightly in the MID group (2.2% ± 3.7%, P < 0.05) by the end of the supplementation period and remained at this level for the following 12 wk. [Hb] and Hbmass were similarly affected, but Hbmass was more closely related to mean corpuscular volume and mean corpuscular hemoglobin than [Hb]. The SID group incorporated 534 ± 127 mg of iron into ferritin and hemoglobin, whereas the MID group incorporated 282 ± 68 mg of iron. V˙O2max increased only in the SID group by 0.20 ± 0.18 L·min (P < 0.05) and was closely related to Hbmass (P < 0.01). CONCLUSIONS: Hbmass is a sensitive tool for monitoring recovery from iron deficiency anemia and assessing the effectiveness of iron supplementation in individuals with severe or moderate iron deficiency.

Phenotypic characterization of human chondrocyte cell line C-20/A4: a comparison between monolayer and alginate suspension culture.

DNA microarray analysis was used to investigate the molecular phenotype of one of the first human chondrocyte cell lines, C-20/A4, derived from juvenile costal chondrocytes by immortalization with origin-defective simian virus 40 large T antigen. Clontech Human Cancer Arrays 1.2 and quantitative PCR were used to examine gene expression profiles of C-20/A4 cells cultured in the presence of serum in monolayer and alginate beads. In monolayer cultures, genes involved in cell proliferation were strongly upregulated compared to those expressed by human adult articular chondrocytes in primary culture. Of the cell cycle-regulated genes, only two, the CDK regulatory subunit and histone H4, were downregulated after culture in alginate beads, consistent with the ability of these cells to proliferate in suspension culture. In contrast, the expression of several genes that are involved in pericellular matrix formation, including MMP-14, COL6A1, fibronectin, biglycan and decorin, was upregulated when the C-20/A4 cells were transferred to suspension culture in alginate. Also, nexin-1, vimentin, and IGFBP-3, which are known to be expressed by primary chondrocytes, were differentially expressed in our study. Consistent with the proliferative phenotype of this cell line, few genes involved in matrix synthesis and turnover were highly expressed in the presence of serum. These results indicate that immortalized chondrocyte cell lines, rather than substituting for primary chondrocytes, may serve as models for extending findings on chondrocyte function not achievable by the use of primary chondrocytes.

EFFECT OF LOW SELENIUM ON CHONDROCYTE DIFFERENTIATION AND DIFFERENTIAL EXPRESSION OF COLLAGEN TYPES Ⅰ , Ⅱ AND X IN ARTICULAR CARTILAGE FROM MINI-PIGS / 药物分析学报

Objective According to the distribution of low selenium areas, low nutrition state of the residents and the affecting cartilage growth and articular cartilage of Kashin-Beck Disease(KBD),the chondrocyte differentia- tion and differential expression of collagen types Ⅰ , Ⅱ and Ⅹ in articular cartilage from Chinese mini-pigs treated with low selenium were investigated in order to gain insight into the effects of these conditions on chondrocyte differ- entiation in KBD cartilage. Mothods Eleven male juvenile mini-pigs, aged from 4 weeks to 6 weeks after birth, were divided into 3 groups. The Se content in the diet of the “low Se” group was 0. 035mg/kg diet, and 0. 175 mg/kg diet in the control. For Se-supplemented group 0. 390mg /kg diet was added. The content of Se in blood was assayed at the beginning and at the end of each experiment. Samples of articular cartilage were taken from the right femur condylus, and collagen types Ⅰ , Ⅱ and Ⅹ in articular cartilage were analyzed by immunohistochemistry and in situ hybridization. Results①All cartilage samples from juvenile mini-pigs fed with low selenium diet revealed a re- duction in type Ⅹ collagen mRNA expression in the hypertrophic chondrocytes as shown by in situ hybridization, and reduced type Ⅹ collagen deposition in the lower hypertrophic zone as shown by immunohistochemistry. ②Addition of selenium to the diet restored the type Ⅹ collagen to normal level. ③Type Ⅱ collagen was evenly distributed over the entire articular cartilage in all experimental and control groups. Type Ⅱ collagen mRNA signals were most prominent in the upper articular layer as well as in the hypertrophic zone in all groups. Type Ⅱ collagen expression was restrict- ed to the zone of endochondral ossification in all experimental groups and the control. Conclusion Low selenium has an down-regulatory role on the synthesis and deposition of collagen type Ⅹ in hypertrophic chondrocytes in articular cartilage of mini-pigs. Supplement of the low Se diet with additional Se restored the signals of collagen type Ⅹ to nor- mal levels. These findings indicate that selenium deficiency may disturb chondrocyte differentiation to hypertrophic cells in the growth plate,and worthy to be investigated further.