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Progressive increases in the incidence of male reproductive disorders inclusive of hypospadias, cryptorchidism, poor semen quality, and testicular germ cell cancer (TGCC) have been observed in recent times. The central hypothesis of this study asserted that these disorders may all collectively signify testicular dysgenesis syndrome (TDS). This review aimed to provide evidence verifying the reality of TDS based on four key aspects: environmental endocrine-disrupting chemicals (EDCs), genetic factors, intrauterine growth disorders and lifestyle factors. Although TDS might result from genetic polymorphisms or aberration, recent evidence has highlighted links indicating the conditions associations to both environmental and lifestyle factors due to the rapid temporal changes in the clinical symptoms observed over recent decades. Based on our review of genetic and environmental factors, a key observation of our study suggested that there is an urgent need to prioritize research in reproductive physiology and pathophysiology, particularly in highly industrialized countries facing decreasing populations. At present, current research has yet to elucidate the mechanisms of TDS, in addition to the lack of genuine consideration of a variety of potentially key factors and TDS mechanisms. In conclusion, our study revealed that environmental exposures owing to modern lifestyles are primary factors involved in the associated trends of the syndrome, which are capable of affecting the adult endocrine system via direct means or through epigenetic mechanisms., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Aims: In order to evaluate the role of metallothionein (MT)-III in cadmium (Cd)-induced testicular toxicity, we examined the sensitivity of MT-III null mice to severe testicular injury caused by Cd., Main Methods: Male MT-III null mice, MT-I/II null mice and wild-type mice were given a subcutaneous injection of CdCl(2) (15μmol/kg). The testis was collected from each mouse at 6, 12 and 24h after Cd administration., Key Findings: Testicular hemorrhages by evaluating morphology, hemoglobin content and histological parameters in the 3 types of mice were elevated by Cd injection in a time-dependent manner. The degree of hemorrhage in Cd-injected MT-I/II null mice was similar to that in the wild-type mice. In contrast, hemorrhage in the MT-III null mice was attenuated compared with that in wild-type mice and MT-I/II null mice. Cd levels, MT-I and MT-II mRNA levels and Cd-binding molecules in the testis were similar between MT-III null mice and wild-type mice. In microarray analysis, high expression of purine-nucleoside phosphorylase 2 (Pnp2), retinal degeneration 3 (Rd3), and cadherin-like 24 (Cdh24) was revealed in the testis of MT-III null mice under normal or Cd-treated conditions., Significance: MT-III null mice were found to show attenuation of Cd-induced severe testicular toxicity. These results suggest the lack of MT-III contributes to protection of testis from Cd. In addition, regulation of Pnp2, Rd3, and Cdh24 mRNA levels may involve the sensitivity of MT-III null mice to Cd., (Copyright © 2010 Elsevier Inc. All rights reserved.)

We have reported that xeroderma pigmentosum group A (Xpa) gene-knockout mice [Xpa (-/-) mice] are deficient in nucleotide excision repair (NER) and highly sensitive to UV-induced skin carcinogenesis. Although xeroderma pigmentosum group A patients show growth retardation, immature sexual development, and neurological abnormalities as well as a high incidence of UV-induced skin tumors, Xpa (-/-) mice were physiologically and behaviorally normal. In the present study, we kept Xpa (-/-) mice for 2 years under specific pathogen-free (SPF) conditions and found that the testis diminished in an age-dependent manner, and degenerating seminiferous tubules and no spermatozoa were detected in the 24-month-old Xpa (-/-) mice. In addition, a higher incidence of spontaneous tumorigenesis was observed in the 24-month-old Xpa (-/-) mice compared to Xpa (+/+) controls. Xpa (-/-) mice provide a useful model for investigating the aging and internal tumor formation in XPA patients.

X-linked mental retardation (XLMR) is a heterogeneous disorder with both syndromic and non-syndromic forms. Here we describe the clinical and molecular characterisation of a family with a syndromic form of XLMR with hypogonadism and short stature. We investigated a family in which four male members in two generations presented with hypergonadotrophic hypogonadism associated with development of small and abnormal testes. In two of the males, late-onset testicular ascent was noted. In addition, all affected males had short stature (<0.4th centile) and mild learning difficulties and three out of the four had microcephaly. Karyotypes were normal and endocrine investigations confirmed primary testicular failure. The phenotype segregated as an X-linked trait. Haplotype and genetic two-point linkage analysis with 22 microsatellites excluded the whole X chromosome except for a region on Xq25-Xq27 encompassing 13.7Mb with a maximum LOD score of 1.1 for marker DXS8038 at theta=0.05. One family previously described as having XLMR with hypogonadism and short stature maps to the same X chromosome region implicated in our family. However, the more severe mental retardation, muscle wasting and tremor described in this other family would suggest that our family is affected by a novel XLMR syndrome.

A family with adult spinal and bulbar muscular atrophy with X-linked recessive inheritance (Kennedy's disease) is described. Affected members presented at age 20 with muscle cramps followed insidiously by gynaecomastia, partial loss of secondary sexual traits, loss of libido and inability to maintain an erection. Three had also testicular atrophy and severe oligospermia was found in two patients. Testicular biopsy in one case showed germinal failure with almost normal Leydig cells. Hormonal tests were suggestive of a primary testicular failure. Etiologic possibilities are considered.

A simple method was developed for assay of androgen binding protein (ABP) in the reproductive tract of male rats. Dextran-coated charcoal was employed to separate bound and free steroid. The number of binding sites quantified by this technique was the same as those determined by other procedures. The ABP levels in testis and epididymis of Hre rats was much lower than those from normal littermates. This abnormality was correlated with defective spermatogenesis in these animals.