Cryptorchidism: seasonal variations in Greece do not support the theory of light

Dysregulation of mitochondrial sirtuin genes is associated with human male infertility

Mitochondrial sirtuins (SIRT3, SIRT4, SIRT5) are post-translational modifiers that regulate energy production, body homeostasis and mitochondrial activities via different substrates in response to environmental stressors. The present study aimed at assessing the expression of SIRT3, SIRT4, and SIRT5 in the semen of infertile men. Expression analysis was performed using q-RT PCR. All mitochondrial sirtuin genes were significantly down-regulated in the semen of infertile men compared to fertile men. Mitochondrial sirtuin genes expression levels were correlated with mitochondrial HSP90 expression. HSP90 expression was positively correlated with SIRT3, SIRT4 and SIRT5 expression in the semen of fertile men, while a negative correlation was observed between HSP90 in the semen of infertile men and mitochondrial sirtuin genes in the semen of fertile men. These data suggest that dysregulation of mitochondrial sirtuin genes causes mitochondrial dysfunction due to stress, which appears to be associated with human male infertility by compromising functional and structural sperm integrity.

Impact of organochlorine pollutants on semen parameters of infertile men in Pakistan

Male infertility is a major problem with important socioeconomic consequences. It is associated with several pathological factors, including but not limited to endocrine disruption as a result of environmental pollution and the alarming decline in sperm count over the decades is indicative of involvement of many environmental and lifestyle changes around the globe. Organochlorine pollutants such as dichlorodiphenyltrichlorethanes (DDTs), polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB) disrupt male reproductive system but the exact effect of environmental exposure on semen parameters in human is still not clear. This study was designed to monitor PCBs, DDTs and HCB in hair, urine and serum samples of infertile and healthy fertile men. Solid-phase microextraction gas chromatography-mass spectrometry (SPME/GC-MS) was used to monitor analytes. All tested compounds were detected, indicating recent use/persistent accumulation. Hair samples revealed no significant association with serum/urine concentrations of the analytes, while serum/urine concentrations were significantly correlated positively. Concentrations were higher in serum compared to other samples. The levels of organochlorine pollutants were higher in infertile men compared to controls with few exceptions. Among PCBs, and DDTs, PCB-153 and pp'-DDT were detected in highest concentrations, respectively. op'-DDT and pp'-DDT levels were significantly higher in infertile men compared to controls. HCB was significantly correlated negatively with sperm motility in all samples. Serum concentrations of all compounds were higher in men with defective semen parameters compared to normospermics. Serum was the best biological sample for assessing health outcomes in relation to exposure levels.

Endocrine Disruptors Acting on Estrogen and Androgen Pathways Cause Reproductive Disorders through Multiple Mechanisms: A Review

Increasing contamination of the environment by toxic compounds such as endocrine disrupting chemicals (EDCs) is one of the major causes of reproductive defects in both sexes. Estrogen/androgen pathways are of utmost importance in gonadal development, determination of secondary sex characteristics and gametogenesis. Most of the EDCs mediate their action through respective receptors and/or downstream signaling. The purpose of this review is to highlight the mechanism by which EDCs can trigger antagonistic or agonistic response, acting through estrogen/androgen receptors causing reproductive defects that lead to infertility. In vitro, in vivo and in silico studies focusing on the impact of EDCs on estrogen/androgen pathways and related proteins published in the last decade were considered for the review. PUBMED and PUBCHEM were used for literature search. EDCs can bind to estrogen receptors (ERα and ERβ) and androgen receptors or activate alternative receptors such as G protein-coupled receptors (GPCR), GPR30, estrogen-related receptor (ERRγ) to activate estrogen signaling via downstream kinases. Bisphenol A, dichlorodiphenyltrichloroethane, dichlorodiphenyldichloroethylene, polychlorinated biphenyls and phthalates are major toxicants that interfere with the normal estrogen/androgen pathways leading to infertility in both sexes through many ways, including DNA damage in spermatozoids, altered methylation pattern, histone modifications and miRNA expression.

Cryptorchidism after the Fukushima Daiichi Nuclear Power Plant accident:causation or coincidence?

Cryptorchidism (undescended testes) is among the most common congenital diseases in male children. Although many factors have been linked to the incidence of cryptorchidism, and testicular androgen plays a key role in its pathogenesis, the cause remains unknown in most cases. Recently, a Japanese group published a speculative paper entitled, "Nationwide increase in cryptorchidism after the Fukushima nuclear accident." Although the authors implicated radionuclides emitted from the Fukushima accident as contributing to an increased incidence of cryptorchidism, they failed to establish biological plausibility for their hypothesis, and glossed over an abundance of evidence and expert opinion to the contrary. We assessed the adequacy of their study in terms of design setting, data analysis, and its conclusion from various perspectives. Numerous factors must be considered, including genetic, environmental, maternal/fetal, and social factors associated with the reporting of cryptorchidism. Other investigators have established that the doses of external and internal radiation exposure in both Fukushima prefecture and the whole of Japan after the accident are too low to affect testicular descent during fetal periods;thus, a putative association can be theoretically and empirically rejected. Alternative explanations exist for the reported estimates of increased cryptorchidism surgeries in the years following Japan's 2011 earthquake, tsunami, and nuclear crisis. Data from independent sources cast doubt on the extent to which cryptorchidism increased, if at all. In any case, evidence that radionuclides from the Fukushima Daiichi Nuclear Power Plant could cause cryptorchidism is lacking.

Nephrotoxicity issues of organophosphates

Organophosphates are a large class of chemicals, initially invented in 1850 and since then they have been applied in numerous aspects of science to serve our purposes. Their mechanism of action in living organisms involves the irreversible inhibition of acetylcholinesterase, therefore they interfere with neuromuscular signal transmission. Due to the systematic and exaggerated use of these chemicals, there is massive exposure to them, hence there is great concern regarding the ramifications to all mammalian organisms. It has been widely accepted that over-exposure to organophosphates, has a deleterious impact on the renal tissue and subsequently on the renal function. Despite the significance of this global issue, limited knowledge exists, regarding the effect of these substances on our health. Therefore, new and extensive research is required to expand our knowledge and ensure proper guidance regarding the use of organophosphates as well the protection against their detrimental consequences. The aim of this review is to negotiate the effect of organophosphate exposure on renal tissue and kidney function.

Molecular and clinical aspects of embryotoxicity induced by acetylcholinesterase inhibitors

Acetylcholinesterase inhibitors are widely used for a variety of medical, agricultural and public health purposes. Consequently, exposure is highly possible during lifetime. However, their systematic use raises concerns for the potential impact on the fetus and newborn since these substances may affect angiogenesis, the neonatal and maternal intensive care, neuroimmune function and response, mammary growth/lactation via cholinergic/non-cholinergic central and peripheral neuroendocrine pathways. New methodologies, neuroscientific technologies and research studies are needed to harness existing knowledge along with the proper management, availability for new acetylcholinesterase inhibitors, with stable pharmacodynamics and clinical outcomes.

Association of pesticide exposure with human congenital abnormalities

Human pesticide exposure can occur both occupationally and environmentally during manufacture and after the application of indoor and outdoor pesticides, as well as through consumption via residues in food and water. There is evidence from experimental studies that numerous pesticides, either in isolation or in combination, act as endocrine disruptors, neurodevelopmental toxicants, immunotoxicants, and carcinogens. We reviewed the international literature on this subject for the years between 1990 and 2017. The studies were considered in this review through MEDLINE and WHO resources. Out of the n = 1817 studies identified, n = 94 were reviewed because they fulfilled criteria of validity and addressed associations of interest. Epidemiological studies have provided limited evidence linking pre- and post-natal exposure to pesticides with cancers in childhood, neurological deficits, fetal death, intrauterine growth restriction, preterm birth, and congenital abnormalities (CAs). In this review, the potential association between pesticide exposure and the appearance of some human CAs (including among others musculoskeletal abnormalities; neural tube defects; urogenital and cardiovascular abnormalities) was investigated. A trend towards a positive association between environmental or occupational exposure to some pesticides and some CAs was detected, but this association remains to be substantiated. Main limitations of the review include inadequate exposure assessment and limited sample size. Adequately powered studies with precise exposure assessments such as biomonitoring, are warranted to clarify with certainty the potential association between pesticide exposure and human CAs.

Risk factors for cryptorchidism

Undescended testis - known as cryptorchidism - is one of the most common congenital abnormalities observed in boys, and is one of the few known risk factors for testicular cancer. The key factors that contribute to the occurrence of cryptorchidism remain elusive. Testicular descent is thought to occur during two hormonally-controlled phases in fetal development - between 8-15 weeks (the first phase of decent) and 25-35 weeks gestation (the second phase of descent); the failure of a testis to descend permanently is probably caused by disruptions to one or both of these phases, but the causes and mechanisms of such disruptions are still unclear. A broad range of putative risk factors have been evaluated in relation to the development of cryptorchidism but their plausibility is still in question. Consistent evidence of an association with cryptorchidism exists for only a few factors, and in those cases in which evidence seems unequivocal the factor is likely to be a surrogate for the true causal exposure. The relative importance of each risk factor could vary considerably between mother-son pairs depending on an array of genetic, maternal, placental and fetal factors - all of which could vary between regions. Thus, the role of causative factors in aetiology of cryptorchidism requires further research.

Seasonal trends in the prevalence of hypospadias: Aetiological implications

The aim of the present study was to examine the seasonality of hypospadias in Greece in an attempt to elucidate the aetiology. All boys born between 1991-1998, who underwent hypospadias repair at 'Aghia Sophia' Children's Hospital, Athens (n=542) were analysed. All Greek live-born males during the same period (population at risk; m=421,175) served as the controls. Seasonality by month of birth was evaluated with specific statistical tools. Meteorological parameters were also analysed. All tests yielded significant results, suggesting a simple harmonic prevalence pattern (highest/lowest: autumn, peak in October/spring, trough in April). Therefore, the first trimester of hypospadiac gestations coincides more frequently with winter. Meteorological parameters varied seasonally (maximal sunlight; air temperature in summer/minimal in winter, maximal rainfall in winter/minimal in summer) and were strongly associated pairwise. Hypospadiac birth prevalence follows a simple harmonic seasonal pattern and is associated with that of cryptorchidism in Greece. The coincidence of the first or third trimester of a potentially genetically influenced gestation with winter could lead to the phenotypic expression of hypospadias or cryptorchidism, respectively. The potential role of a cyclic-varied androgen-production stimulator, such as human chorionic gonadotrophin may be speculated. The seasonality of a common environmental factor acting directly/indirectly may contribute to these patterns, and possibly to the common pathogenesis of these congenital malformations.

Seasonality in sperm parameters in normal men and dyspermic patients on medical intervention

This study attempted to investigate the presence of seasonal variations in sperm parameters and to evaluate the season's impact on the response to treatment in men with idiopathic oligozoospermia (IO). To this end, a retrospective analysis of the records of 294 men, who participated in a controlled study, was performed. This sample included IO men (n = 106) treated with tamoxifen citrate (10 mg b.i.d.) and testosterone undecanoate (40 mg t.i.d.) or placebo (n = 106) and normozoospermic men (n = 82) serving as controls. Outcome measures included sperm parameters, functional sperm fraction (FSF) and incidence of pregnancy. Analysis showed a raised frequency of high FSF values and increased area under the response curve (AURC) for FSF mean during autumn-winter seasons in patients on active treatment compared with those in placebo (P < 0.05-P < 0.04). Moreover, receiver operation characteristics (ROC) curves for a >100% FSF rise significantly discriminated autumn-winter from other seasons (P < 0.001, all), whereas active treatment showed higher than placebo FSF values particularly during autumn and winter (P < 0.001, all). The pregnancy incidence was higher in the autumn in all groups. It is concluded that FSF values showed a better response to active treatment during autumn and winter, indicating that commencement of empirical treatment at this time in IO men may stand a better chance to succeed.

Simple estimators of the intensity of seasonal occurrence

Background

Edwards's method is a widely used approach for fitting a sine curve to a time-series of monthly frequencies. From this fitted curve, estimates of the seasonal intensity of occurrence (i.e., peak-to-low ratio of the fitted curve) can be generated.

Methods

We discuss various approaches to the estimation of seasonal intensity assuming Edwards's periodic model, including maximum likelihood estimation (MLE), least squares, weighted least squares, and a new closed-form estimator based on a second-order moment statistic and non-transformed data. Through an extensive Monte Carlo simulation study, we compare the finite sample performance characteristics of the estimators discussed in this paper. Finally, all estimators and confidence interval procedures discussed are compared in a re-analysis of data on the seasonality of monocytic leukemia.

Results

We find that Edwards's estimator is substantially biased, particularly for small numbers of events and very large or small amounts of seasonality. For the common setting of rare events and moderate seasonality, the new estimator proposed in this paper yields less finite sample bias and better mean squared error than either the MLE or weighted least squares. For large studies and strong seasonality, MLE or weighted least squares appears to be the optimal analytic method among those considered.

Conclusion

Edwards's estimator of the seasonal relative risk can exhibit substantial finite sample bias. The alternative estimators considered in this paper should be preferred.

Circannual rhythm in the incidence of cryptorchidism in Finland

Conflicting data on circannual variation in birth rates of urogenital malformations have been reported previously. To assess risk factors of cryptorchidism we studied the seasonal variation of cryptorchidism in Finland. We performed a prospective cryptorchidism study in Turku, Finland, from 1997 to 2001 to evaluate the incidence of cryptorchidism. Clinical examinations were performed at birth and at 3 months. Of 9511 liveborn boys (1471 preterm boys) 216 (53 preterm boys) were cryptorchid at birth and 106 (19 preterm boys) at 3 months. The incidence of cryptorchidism was significantly higher in spring (February-April) (3.0%) than in summer (May-July) (1.7%) (OR 1.79; 95% CI: 1.23-2.63). This seasonal difference was observed both among preterm and term boys. We conclude that a circannual fluctuation in the incidence of cryptorchidism exists, which indicates an influence by environmental factors. The underlying reason for cyclicity affects similarly both preterm and term boys.

Electronic Data Base Systems Support the Evaluation of Male Infertility Factors, Example Cryptorchidism

BACKGROUND

A new data base system was applied to analyse our patient group with two aims: (a) to analyze the effects of former cryptorchidism on the fertility of OUR infertility patients in comparison with the data of the literature and (b) to evaluate this system in a clinical study.

MATERIALS AND METHODS

Using the electronic data base Winsperm 2000, 1,648 infertility patients, 79 patients with testicular cancer and 201 healthy semen donors were examined.

RESULTS

A history of cryptorchidism, treated at 6.8 +/- 3.3 years of life, was found in 10.1% of our infertility patient group. The routine spermiogram parameters, as well as basal hormone concentration of FSH, LH and testosterone, differed significantly from those of the healthy semen donor group. Comparison between patients with former unilateral and bilateral cryptorchidism differed significantly only in total sperm count. 27.7% of patients with a history of unilateral and 5.4% of patients with a history of bilateral cryptorchidism showed a sperm concentration within the normal range (p < 0.01). Azoospermia was detected in 13.1% of patients with unilateral cryptorchidism and in 29.7% of patients with former bilateral cryptorchidism (p < 0.05). The patients responding to our conception questionnaire realised a total conception rate of 46.1% in the 'non-cryptorchidism group' and of 20.6% in the 'cryptorchidism-group' (p < 0.05), whereas the conception rates did not differ between former unilateral and bilateral cryptorchidism (p > 0.05). Sixteen (20.3%) of the 79 patients with testicular neoplasm were previously treated for cryptorchidism.

CONCLUSION

The results of our patient group underline the significance of former cryptorchidism for infertility and testicular neoplasm. The new data base system facilitates rapid data retrieval and examination.