The Fertilizing Capacity of Golden Hamster Epididymal Spermatozoa in Relation to Age, Number, Motility and Morphology

Experiments with spermatozoa of prepubertal hamsters aged 35-48 days were performed in order to determine if the appearance of spermatozoa with fertilizing capacity in the cauda epididymis during puberty is related to changes in their morphology, motility and number. Epididymal spermatozoa of prepubertal animals were evaluated for number, motility and morphology and were injected into one uterine horn of a female, following induction of ovulation. A comparable number of sperm from mature animals (which served as control) was injected into the contralateral horn. Prior to 40 days fertilizing capacity was nil. It increased thereafter and reached control levels of 74% at 48 day age. Concomitantly there was an increase in the number of sperm per cauda epididymidis from less than 1 million to 55 million. Following removal of spermatozoa from the cauda the motility increased from 24% motile cells at the age of 39 days to 66% at the age of 48 days when most cells exhibited progressive motility. The percentage of cells having normal morphology increased from 18% at the age of 39 days to 50% at the age of 48 days. Developmental processes resulting in improvement of cell motility, morphology and number are correlated with attainment of fertilizing capacity. These processes seem to be gradual and occur between time of completion of spermatogenesis and time when capacity for fertilization is achieved.     

基因重组生长激素治疗青春期前特发性矮小疗效观察

目的探讨基因重组人生长激素（rhGH）对青春期前特发性矮小（ISS）的疗效。方法观察27例青春期前特发性矮小患儿,平均年龄（8.9±2.0）岁,身高（118.0±10.6）cm。治疗组13例,男10例,女3例,均接受基因重组人生长激素治疗,剂量（0.12±0.01）IU/kg,睡前皮下注射,疗程6个月至1年;对照组14例,男6例,女8例。结果治疗组患儿生长速率（GV）由治疗前（4.28±0.86）cm/a提高到（9.38±1.77）cm/a,P〈0.01;年龄身高标准差积分（HtSDSCA）由-2.28±0.48增至-1.72±0.62（P〈0.01）;骨龄身高标准差积分（HtS-DSBA）由-0.24±1.02增至0.27±0.99（P〈0.05）;与对照组比较,GV、HtSDS（CA）和HtSDS（BA）差异均有统计学意义（P均〈0.05）;两组△BA/△CA比较差异无统计学意义（P均〉0.05）。结论GH治疗能改善ISS儿童的GV及HtSDS（CA）、HtSDS（BA）,而骨龄（BA）加速不明显,疗效肯定。     

Germinal epithelium changes in sexually immature rabbits treated with intratesticular testosterone implants: Samenepithel-Veränderungen bei unreifen Kaninchen nach Behandlung mit intrascrotalen Testosteron-Implantaten

The effect of testosterone (T) on germinal epithelium development and maturation was studied in prepubertal male rabbits. For this purpose, implants of free T (50 mg) or placebo (PL) were placed intratesticularly in 55-60-day-old animals. Each group was divided into sub-groups additionally treated with 0.9% NaCl, FSH/LH (3.0 IU) or cyproterone acetate (CA, 2.5 mg) over a 45-day period. Initial and final evaluations included measurements of testicular volume, testicular biopsy score count (TBSC) and plasma T, FSH and LH concentrations. At the end of the experiment, increment values (final-initial evaluation) of the parameters examined showed the following differences: (1) mean TBSC in T-implanted, irrespective of additional treatment, was higher than that of PL-implanted rabbits (P less than 0.01); (2) mean plasma T, FSH and LH values were significantly different in T- and PL-implanted rabbits, with higher T (P less than 0.05) but lower FSH and LH increments (P less than 0.01 for both) in the former group; (3) marked differences amongst types of additional treatment, irrespective of the implant used, were found for TBSC, T, FSH and LH (P less than 0.01 for all); animals treated with CA had markedly lower increments than other treatment groups. From these findings, it may be concluded, that in the prepubertal rabbit T plays an important role in development and maturation of the testis, but this effect probably requires the synergistic action of endogenous gonadotrophins.     

Effect of cold storage and cryopreservation of immature non-human primate testicular tissue on spermatogonial stem cell potential in xenografts

BACKGROUND: Successful cryopreservation of gonadal tissue is an important factor in guaranteeing the fertility preservation via germ cell or testicular tissue transplantation. The aim of this study was to evaluate the effects of cooling and cryopreservation on spermatogonial stem cell survival and function of immature non-human primate testicular tissue xenografted to nude mice. METHODS: Group 1 (control group) received subcutaneous grafts of fresh immature rhesus monkey testes. The treatment groups received grafts after 24 h cooling in ice-cold medium (Group 2), after 24 h of cryopreservation without cryoprotectant (Group 3), with ethylene glycol (Group 4: 1.4 M) or with dimethylsulphoxide (DMSO) (group 5: 1.4 M; group 6: 0.7 M), using cooling rates of 0.5 degrees C/min. The graft number, weight and histology were examined 3-5 months later. RESULTS: After xenografting, grafts from fresh and cooled tissue showed good survival and spermatogenic induction to spermatocytes. Cryopreservation in 1.4 M DMSO also allowed grafts to initiate spermatogenesis. In contrast, 0.7 M DMSO and ethylene glycol showed inferior protection. CONCLUSIONS: Our observations suggest that cryopreservation of immature primate testis is a feasible approach to maintain spermatogonial stem cells and may serve as a promising tool for fertility preservation of prepubertal boys. The possibility to delay the transplantation of cooled samples suggests an option for clinical centralization of testicular tissue cryopreservation.     

Developmental and functional evidence of nuclear immaturity in prepubertal oocytes

BACKGROUND: The nuclear compartment has been proposed as responsible for the developmental arrest of prepubertal mouse oocytes while the studies on prepubertal sheep and cow oocyte model suggested the cytoplasm immaturity accounts for this failure. METHODS: The apparent disagreement on the causes of developmental defects between these two species prompted us to study: (i) follicular and oocyte growth allometry in lambs, (ii) oocyte compartment (nucleus versus cytoplasm) responsible for developmental failure by nucleus exchange between lamb and adult sheep oocytes, (iii) nucleolar features of prepubertal oocytes by ultrastructural observation and (iv) in vivo developmental survey of prepubertally derived embryos. RESULTS: The oocyte growth inside the follicle is asynchronous during prepuberty. The nuclear transfer revealed that the lamb nucleus was responsible for developmental failure. Immature fibrillogranular structure of the nucleolus has been revealed in small lamb oocytes and also in a few adult-size lamb oocytes. Studies in vivo revealed a high occurrence of developmental arrest of prepubertal derived fetuses, which we have attributed to the low genome-wide methylation detected in prepubertal oocytes. CONCLUSIONS: Our studies have indicated incomplete nuclear maturation of prepubertal gamete. The implication of this finding suggests caution when the strategy of rescue of prepubertal oocytes for assisted fertilization is considered such as in the case of therapeutic treatment which precludes the maintenance of fertility of sexually immature patients.     

Relation between serum Insulin-like growth factor-I and insulin-like growth factor-binding protein-3 levels, clinical status and growth parameters in prepubertal cystic fibrosis patients

BACKGROUND: This study aims to determine the relation between anabolic hormones, Insulin-like growth factor-I (IGF-I) and IGF-binding protein-3 (IGFBP-3), growth parameters, and clinical status in prepubertal cystic fibrosis (CF) patients. This prospective study comprises age/sex-matched control subjects and was set in a tertiary care teaching hospital. METHODS: Serum concentrations of IGF-I and IGFBP-3 were measured in 37 CF and 23 healthy subjects, whose mean ages were 5.02 +/- 3.06 and 5.27 +/- 2.82, respectively. The results were analyzed in relation to body mass index standard deviation scores (BMISD), height standard deviation scores (HSD), growth velocity standard deviation scores (GVSD), and clinical status assessed by Shwachman scores and pulmonary function parameters. RESULTS: Serum IGFBP-3 of CF patients showed significantly lower concentrations than healthy subjects (2457 vs. 3249 ng/mL) (P < 0.05), whereas IGF-I levels did not (123.35 vs. 149.8 ng/mL). There was significant positive correlation between IGF-I and IGFBP-3 with HSD (r = 0.62; r = 0.79) and BMISD (r = 0.39; r = 0.50). The pulmonary function tests in 14 CF subjects were not statistically worse than in nine healthy cases. The mean HSD (-0.67, SD 1.06) and BMISD (-0.28, SD 0.71) of CF patients were not significantly lower than those of healthy subjects (-0.02, SD 0.86 and 0.03, SD 0.49), respectively. CONCLUSION: Decreased serum IGF-I and IGFBP-3 levels may reflect growth retardation in CF. IGFBP-3 seems like a more sensitive parameter than IGF-I for growth monitoring in this study. Growth parameters of Turkish prepubertal CF patients are not markedly below national standards. Different genetic backgrounds of relevant populations certainly play an important role for the variable clinical course.     

青春期前己烯雌酚暴露对SD大鼠睾丸发育及功能的影响

目的:研究青春期前己烯雌酚(DES)暴露对SD大鼠睾丸发育及功能的影响。方法:21日龄雄性SD大鼠90只,随机分为DES0.01、0.1、1.0、10.0μg/(kg.d)4个实验组和1个对照组(分别为Da、Db、Dc、Dd和C组,每组n=18)。于青春期前,即出生后第22d(postnatalday22,PND22)～35d(PND35),实验组每日皮下注射相应剂量的DES,共14d,对照组仅注射溶媒(玉米油)。观察各组大鼠睾丸下降时间。于青春期晚期(PND50)、性成熟后(PND64)和成年期(PND130)分3批(每批n=6)处死各组大鼠取材,测定睾丸重量,观察比较睾丸组织形态学变化,分析PND130大鼠附睾尾精子质量。结果:C、Da、Db、Dc和Dd组睾丸下降时间分别为PND26.17±1.94、26.83±1.47、28.68±1.03、33.50±1.87和41.50±2.74,其中Db、Dc和Dd组较C组明显延迟(P<0.05或P<0.01)。PND50时,C、Da、Db、Dc和Dd组单侧睾丸重量分别为(1.38±0.10)、(1.38±0.12)、(1.30±0.14)、(0.86±0.18)g和(0.73±0.27)g,其中Dc和Dd组较C组显著减轻(P<0.01);与C组比较,Db组仅有少数生精小管生精上皮中的细胞数目稍减少,Dc和Dd组生精小管发育较差、生精上皮中细胞数目减少、精子发生阻滞、间质细胞发育幼稚,其程度随DES暴露剂量增加而加重。PND64时,C、Da、Db、Dc和Dd组单侧睾丸重量分别为(1.60±0.06)、(1.62±0.11)、(1.58±0.08)、(1.47±0.10)g和(0.99±0.37)g,其中Dc和Dd组较C组显著减轻(P<0.05或P<0.01);Dc和Dd组睾丸组织形态学改变与PND50时类似,但总体较PND50有所改善。PND130时,各实验组与对照组比较,单侧睾丸重量差异无统计学意义(P>0.05),睾丸组织形态学改变难以鉴别出明显差异;C、Da、Db、Dc和Dd组大鼠附睾尾精子密度分别为(73.00±16.90)、(68.00±19.67)、(68.67±12.15)、(35.17±15.64)×106/ml和(19.13±5.17)×106/ml,其中Dc和Dd组精子密度较C组明显降低(P<0.01);与C组比较,Dd组精子活动率下降(P<0.01),Db、Dc和Dd组a级精子比例降低(P<0.05或P<0.01),Dd组b级精子比例降低(P<0.01)。结论:青春期前小剂量DES[0.01μg/(kg.d)×14d]暴露对SD大鼠睾丸发育及功能无明显影响,较大剂量DES[1.0～10.0μg/(kg.d)×14d]暴露对大鼠睾丸发育及功能有明显的近期(PND50和PND64)和较远期(PND130)毒性作用,该毒性作用随DES的暴露剂量增加而加重,随鼠龄增长而逐渐减退,其机制可能与间质细胞和支持细胞的发育及功能受损相关。