Objective:To establish an arsenic free fully automatic online digestion iodine analyzer detection method for urinary iodine (hereinafter referred to as the method).Methods:Based on the principle of iodine catalyzed antimony cerium redox reaction, a fully automatic online digestion iodine analyzer was used to determine the iodine content in urine. The effectiveness of the method in terms of detection limit, precision, accuracy (determination of urinary iodine primary standard reference materials GBW09108z and GBW09110f and spiked recovery experiment), and interference experiments was validated. The method was compared with the arsenic cerium catalytic spectrophotometry method recommended by the National Reference Laboratory for Iodine Deficiency Disorders.Results:The linear range of the method was 0 - 300 μg/L, with a correlation coefficient │ r│> 0.999 5. The qualitative and quantitative detection limits were 7.41 and 18.01 μg/L, respectively. The relative standard deviation ( RSD) of urine samples with different iodine concentrations ranged from 1.0% to 1.7%. The results of the determination of iodine concentrations in urine using standard substances GBW09108z and GBW09110f were within the given standard range, with RSD < 2.5%. The range of spiked recovery rates for urine samples with different iodine concentrations was 101.3% to 104.8%, with an overall average spiked recovery rate of 103.0%. The average concentration of the baseline iodine standard solution was determined to be 116.21 μg/L, and the relative error of the concentration determination with the addition of interfering substances was less than 5.0%. The comparison results showed that there was no statistically significant difference in the measurement results between the two methods ( t = - 0.06, P = 0.952). Conclusions:The method adopts automated detection, which is simple to operate, labor-saving, and does not require the use of arsenic trioxide. It has high precision and accuracy, and is suitable for detection of large quantities of samples.

Objective:To establish an arsenic free fully automatic online digestion iodine analyzer detection method for urinary iodine (hereinafter referred to as the method).Methods:Based on the principle of iodine catalyzed antimony cerium redox reaction, a fully automatic online digestion iodine analyzer was used to determine the iodine content in urine. The effectiveness of the method in terms of detection limit, precision, accuracy (determination of urinary iodine primary standard reference materials GBW09108z and GBW09110f and spiked recovery experiment), and interference experiments was validated. The method was compared with the arsenic cerium catalytic spectrophotometry method recommended by the National Reference Laboratory for Iodine Deficiency Disorders.Results:The linear range of the method was 0 - 300 μg/L, with a correlation coefficient │ r│> 0.999 5. The qualitative and quantitative detection limits were 7.41 and 18.01 μg/L, respectively. The relative standard deviation ( RSD) of urine samples with different iodine concentrations ranged from 1.0% to 1.7%. The results of the determination of iodine concentrations in urine using standard substances GBW09108z and GBW09110f were within the given standard range, with RSD < 2.5%. The range of spiked recovery rates for urine samples with different iodine concentrations was 101.3% to 104.8%, with an overall average spiked recovery rate of 103.0%. The average concentration of the baseline iodine standard solution was determined to be 116.21 μg/L, and the relative error of the concentration determination with the addition of interfering substances was less than 5.0%. The comparison results showed that there was no statistically significant difference in the measurement results between the two methods ( t = - 0.06, P = 0.952). Conclusions:The method adopts automated detection, which is simple to operate, labor-saving, and does not require the use of arsenic trioxide. It has high precision and accuracy, and is suitable for detection of large quantities of samples.

Objective:To study the application of antimony cerium catalytic spectrophotometry using a fully automatic biochemical analyzer (hereinafter referred to as this method) in the determination of water iodine.Methods:Based on the principle of antimony cerium reoxidation reduction reaction catalyzed by iodine, the iodine content in water was determined in the range of 0 - 100 μg/L iodine mass concentration. The detection limit, precision and accuracy (determination of standard substances GBW09113j and GBW09114j for iodine composition analysis in water and the experiment of standard recovery) of this method were verified. This method was compared with the arsenic and cerium catalytic spectrophotometry recommended by the National Reference Laboratory for Iodine Deficiency Disorders.Results:Within the range of 0 - 100 μg/L iodine mass concentration, the qualitative and quantitative detection limits of this method were 0.81 and 2.70 μg/L, respectively (sampling quantity was 35 μl). In the precision experiment, the relative standard deviation of water samples with different iodine mass concentrations ranged from 1.2% to 4.0%. The determination results of the standard substances GBW09113j and GBW09114j for iodine composition analysis in water were both within the given standard value range. The standard recovery rates of water samples with low, medium and high iodine mass concentrations ranged from 101.0% to 106.0%, and the total average standard recovery rate was 103.2%. The results of the method comparison experiment showed that there was no statistically significant difference in the results of water iodine determination between the two methods ( t = - 0.78, P = 0.779). Conclusion:This method has a low detection limit, high precision and good accuracy, making it suitable for the detection of large quantities of samples in the monitoring of iodine deficiency disorders.

Objective:To establish a hydride generation atomic fluorescence method using ammonium persulfate as the digestion reagent for determination of arsenic in urine (hereinafter referred to as this method).Methods:The collected urine samples with ammonium persulfate were heated and digested on the tubular electric heating automatic control constant temperature digester (60 holes), with 5% hydrochloric acid solution as reaction medium and current carrier and 1.5% potassium borohydride solution as reducing agent. Arsenic content was determined with a four-channel atomic fluorescence spectrometer. The arsenic standard solution of 0 - 10 μg/L was prepared to determine the standard curve of this method, and the method was evaluated from the detection limit, linear range, correlation coefficient, precision, standard addition recovery experiment, and urine arsenic quality control sample detection. The standard method "Determination of Arsenic in Urine by Hydride Generation Atomic Fluorescence Spectrometry" (WS/T 474-2015, referred to as the standard method) was used for comparison experiments.Results:When the sampling volume was 1 ml, the detection limit of this method (digest with 1 ml 1.5 mol/L ammonium persulfate) was 0.03 μg/L. In the range of arsenic content from 0 - 10 μg/L, the linear relationship between arsenic content and fluorescence intensity was good, and the correlation coefficients ( r) were all 0.999 9. The relative standard deviations( RSD) of the three replicates of urine samples with different concentrations were 1.00%, 0.89% and 0.49%, respectively. Urine arsenic quality control samples were tested, and the test results were all within the range of public values; the overall average recovery was 102.29%, and the recovery range was 92.10% - 108.15%. Compared with the standard method in the determination results of 20 urine samples, the difference was not statistically significant ( t = - 0.40, P > 0.05). Conclusions:The hydride generation atomic fluorescence spectrometry using ammonium persulfate as digestion reagent for the determination of arsenic in urine has the advantages of low detection limit, good precision, high accuracy, small amount of sampling and digestion reagent, simple operation, and less harmful gas generation in sample pretreatment. It is suitable for rapid determination of arsenic in urine in large quantities.

OBJECTIVETo investigate the development of xenografted primitive human germ cells by using fetal testicular tissues as donor tissues and an immunodeficient mouse as the recipient.

METHODSTesticular tissue fragments of a 26-week fetus were grafted under the back skin of a castrated immunodeficient mouse. Grafts were taken out after 135 days and processed for morphological and histological analyses.

RESULTSThe mass of grafts grew from about 1 mm in diameter and 5 mg in wet weight to about 3 mm and more than 20 mg 135 days after grafting. Histological observations showed a significant expansion of seminiferous tubules after grafting (80 +/- 25 microm in diameter) in comparison with seminiferous cords at the time of grafting (60 +/- 15 microm in diameter). The seminiferous cords developed into seminiferous tubules with the epithelial border and lumen. After 135 days of grafting, most of the dispersedly distributed primitive Sertoli cells and germ cells migrated to the basal part of seminiferous epithelium, located on the basement membrane and few of germ cells differentiated into spermatogonia.

CONCLUSIONHuman fetal testicular tissues could survive and continuously develop after being xenograft into castrated immunodeficient mice.

Animals ; Fetal Tissue Transplantation ; Humans ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Spermatids ; growth & development ; Testis ; cytology ; transplantation ; Transplantation, Heterologous

The Sertoli cell-rich or Sertoli-germ cell aggregates of 15-21 day immature rat testis were cultured in serum-free Ham F-12 medium for observation of the reorganization of the seminiferous tubules in vitro. The results showed that after first week of culture, the cell aggregates were spreaded on the bottom of culture dish as a monolayer consisted of Sertoli cells as well as spermatogenic cells. While after second week these monolayer cell cultures rearranged and transformed into cellular cords which connected each other to form a cellular rete. During this time, there were many small cells with long cytoplasmic processes appeared in the cultures. They looked like immature spermatozoon-like cells which were released from the cellular cords and floated in the medium, however no movement was detected. After third week, the cellular cords developed into a solid or tubule-like structures consisted of Sertoli cells and spermatogenie cells in different stages of spermatogenesis.These cultures have been studied by phase-microscopy in vitro, light and electron microscopy on semithin and ultrathin sections. These studies revealed that the Sertoli cells and Sertoli-germ cell aggregates of immature rat testis, in vitro, not only developed into monolayer cell culture as mentioned, but were also able to be further reconstructed, or reorganized, in some extent, to solid and tubule-like structures. The possible significance and mechanism were discussed.

The postnatal development of the ectoplasmic specialization (ES) of Sertoli cells was investigated in the rats from 1st to 8th week after birth and the adult by electron microscopy. At the end of the 1st week. ES is in the beginning of its formation. Some high electron dense materials accumulate in the submembranous regions and short cisternae of endoplasmic reticulum align in these zones. At the end of the 2nd week the short cisternae are fused each other and straight microfilaments bundles appear and are sandwiched between the flattened cisternae and cell membrane. The density of microfilaments is increased in the 3th week and numerous tight junctions appear between adjacent Sertoli cells. The ES is gradually completed in its structure until the 5th week and fully extend and circumscribed around the base of Sertoli cells. Thereafter, there is no more morphological changes. We conclude that the first 5 weeks after birth is the important period for the development of ES of Sertoli cell as well as the blood-testis barrier in rats.

To investigate the function of microtubules (MTs) in Sertoli cell, colchicine, a microtubule disrupting agents, was injected into the dorsum of the male SD rat. The seminiferous tubules and Sertoli cell of the rat were examined by light and electron microsopy. 5-6 hours after the colchicine injection the following results were revealed (1) The Sertoli cell of the rat testis showed prominent morphological changes. The processes of the cell retracted, the MTs disappeared in the cytoplasm and the distribution of mitochondria and smooth endoplasmic reticulum became irregular. (2) Many widened intercellulor spaces occured in the seminiferous epithelium; and accordingly the arrangement of the germ cells became deranged and the elongated spermatids moved form their original deep position to the surface of the epithelium. (3) There was no evident changes in the basal region of the seminiferous epithilium. These results confirmed that MTs in Sertoli cell are essential to the maintenance of the normal shape and cellular organelle arrangement in the cell as well as the architecture of seminiferous epithelium. They may also play an important role in the movement of the elongated spermatids.

The secretion and localization of epididymal specific proteins ESP-1, ESP-2 were systematically studied by the PAGE-western blot and ABC immunocytochemical technique in the epididymis of the rabbit. The results indicated that ESP-1 and ESP-2 represented the rabbit epididymal specific proteins of 42 kd and 20 kd, respectively. They were immunoeytochemically negative in the testis, heart, liver, spleen, lung, kidney and skeletal muscle of the rabbit as well as testis and epididymis of the rat. However, in the rabbit epididymis, except the initial segment ESP-1 and ESP-2 were started to be positive from caput segment. The ESP-1 was displyed in the supranuclear area of the principle cells, while the ESP-2 was distributed evenly in the whole cytoplasm of it. Subsequently, the most heavy positive reaction was demonstrated in the corpus epididymis and the proximal segment of cauda. In contrast of the caput, the stereocilia of principle cells and lumen sperms of the cauda epididymis were positive also. However, in the distal segment of cauda the positive reaction in cytoplasm of principle cells was gradually decreased and became disappeared completely soon, while the stereocilia of it still remained heavy positive even in that of vas deferens. The epithelium of prostate gland and seminal vesicle were negative. These results indicated that both ESP-1 and ESP-2 were secretory proteins produced mainly in the principle cells of the corpus epididymis. After releasing into the lumen, they took part of epididymal fluid and might bind on the sperm to regulate sperm maturation. The possible physiological significance of ESP-1 and ESP-2 was discussed.

Testicular macrophages and Leydig cells were isolated from rat testis withtrypsin and collagenase treatment respectively.Peritoneal macrophages were obtainedfrom same species by peritoneal cavity lavage.When the testicular macrophages wereco-cultured with Leydig cells,the testosterone secretion was increased and themagnitude of the increased testosterone secretion was directly related to the numberof macrophages added to the cultures(control:6.3?1.5 pmol/10~6 cells,co-culture:9.1?0.9 pmol/10~6 cells,mean?SE,p