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A new column loaded with modified silica gel-chitosan is proposed as a preconcentration system for adsorption of trace cadmium (II) and copper (II). The optimization steps were performed under dynamic conditions, involving pH, sample flow rate, eluent selection, concentration, volume, and flow rate. Trace Cd(II) and Cu(II) were quantitatively adsorbed by the modified silica gel-chitosan. The metal ions adsorbed on the separation column were eluted with 0.1 M HNO3 and determined by flame atomic absorption spectrometry. Under the optimum conditions, this method allowed the determination of cadmium and copper with limits of detection (LOD) of 20 ng L−1 and 38 ng L−1, respectively. The relative standard deviation values (RSDs) for 1.0 mg L−1 of cadmium and 1.0 mg L−1 of copper were 2.62% and 2.85%, respectively.

To explore associated proteins involved in age-related changes of the testis and better understand the roles of these proteins in the human testis.We used two-dimensional polyacrylamide gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization time-of-flight mass spec trometry analysis to identify differentially expressed proteins between the aged and the normal control groups. The L-lactate dehydrogenase C chain (LDHC) protein, a previous testis-specific protein, was found to be downregulated in the aged testis and was further tested with western blot and immunohistochemical analysis to verify the result of the LDHC protein in 2-DE.Twelve differentially expressed proteins were identified. Among those proteins, 3 were upregulated and 9 were downregulated in the aged group. The results of western blot and immunohistochemical analysis confirmed the expression of LDHC downregulation in the aged testis. Some proteins identified had little well-known function in the human testis, as follows: AKR7A3, FDXR, PGAM1, SEPT2 and HMGCS2.Our results imply that the aged testis can be a good model to find associated proteins involved in age-related changes of the testis. It can be useful to understand the roles of those proteins in the testis.

To establish a stable and reliable model of Sertoli-cell-only syndrome in mice.We randomly divided 60 NIH mice into two groups of equal number to receive intraperitoneal injection of busulfan (30 mg/kg) and 30 or 60 minutes of testis cooling. At 2, 4 and 8 weeks after treatment, we recorded the survival rate of the mice, weight of the testis and Johnsen scores, and conducted quantitative analysis on the degrees of spermatogenetic failure.There were no significant differences in the baseline body weight and survival rate between the intervention and control groups (P0.05). At 4 and 8 weeks, the testis weight and Johnsen score were significantly lower in the intervention group than in the control ([0.04 +/- 0.01] g and [0.05 +/- 0.01] g vs [0.09 +/- 0.03] g and [0.11 +/- 0.02] g, P0.05; 3.86 +/- 0.50 and 2.70 +/- 0.67 vs 9.60 +/- 0.25 and 9.76 +/- 0.43, P0.01). At 2, 4 and 8 weeks, the testis weights were (0.07 +/- 0.02) g, (0.06 +/- 0.01) g and (0.09 +/- 0.01) g, respectively, in the 30-min cooling group and (0.05 +/- 0.01) g, (0.04 +/- 0.02) g and (0.04 +/- 0.02) g in the 60-min cooling group, significantly lower than in the control side at the same time points ([0.11 +/- 0.01] g, [0.11 +/- 0.01] g and [0.12 +/- 0.00] g) (P0.05), and the Johnsen scores were 4.70 +/- 0.67, 2.70 +/- 0.84 and 6.10 +/- 1.14 in the 30-min and 1.67 +/- 0.58, 1.20 +/- 0.45 and 1.00 +/- 0.00 in the 60-min cooling group, remarkably lower than in the control side (9.60 +/- 3.23, 9.60 +/- 0.55 and 9.70 +/- 0.45) (P0.01). Histopathological examination of the cooled testes revealed considerable atrophy of seminal tubules, necrosis of seminiferous epithelia and peritubular fibrosis.Administration of busulfan has no obvious influence on the survival of mice, and is a reliable method for constructing a mouse model of Sertoli-cell-only syndrome.