The native turkey (Meleagris gallopavo): male morphophysiology

Objective: To describe the morphophysiology and reproductive characteristics of the male turkey. Methodology: An analysis based on the practical experiences from over 10 years with the native Mexican turkey was developed and complemented with literature reports. Results: In Mexico the production management is customs based on traditions and beliefs. In their reproductive morphophysiology, the epididymis absence stands out, as well as a rapid testicular growth during the breeding season, which is controlled by the photoperiod. Limitations of the study: Native turkey farming is practiced in backyard, in marginalized and low-resource areas that have no strategies (nutritional and reproductive) to improve their production. Conclusions: The anatomical, morphological, physiological and reproductive characteristics of the native Mexican turkey were documented. The knowledge on these characteristics will allow to develop feeding and reproductive strategies to improve the productive and reproductive performance of the native turkey and preserve their genetic resources.

Role of the GH-IGF1 axis on the hypothalamus-pituitary-testicular axis function: lessons from Laron syndrome

BACKGROUND. Animal studies suggest that insulin-like growth factor 1 (IGF1) may influence the function of the hypothalamus-pituitary-testicular axis, especially in childhood, but the evidence in humans is scanty. Laron syndrome, a human model of IGF1 deficiency, may help to solve this issue. PURPOSE. This systematic review aims to analyze puberty onset and progression, testicular volume, gonadotropin, and total testosterone serum levels, sperm parameters and fertility, and penile length in patients with Laron syndrome. METHODS. Specific key-words were used. All data on male patients with Laron syndrome were included. RESULTS. Seventeen articles matched the inclusion criteria and entered in the analysis, for a total of 125 male patients. Puberty was absent in 8.9% and delayed in 35.6% of untreated patients of pubertal age. After onset, the duration of the pubertal process was prolonged in 76.9% of untreated patients. The growth spurt was absent in 52.6% and delayed in 31.6% of untreated patients. The testicular volume was small in the two patients who did not receive any treatment. Treatment with IGF1 increased gonadotropin and testosterone serum levels in 5 out of 5 patients of pubertal age. No effect was found in 4 out of 4 patients younger than 5 years. No study reported data on sperm parameters and fertility. Micropenis occurred in 67.2% of patients. CONCLUSION AND FUTURE PERSPECTIVES. Delayed puberty is common in patients with Laron syndrome. The growth hormone-IGF1 axis may influence the time of puberty onset. Serum levels of IGF1 should be investigated in children with delayed puberty, scarce progression of testicular growth, and/or micropenis.IGF1 levels might be measured in children with delayed puberty, poor testicular growth, and/or micropenis.

Testicular Growth and Pubertal Onset in GH-Deficient Children Treated With Growth Hormone: A Retrospective Study

The prevalence of idiopathic oligozoospermia has been esteemed as high as 75%. An Italian survey has reported bilateral testicular hypotrophy in 14% of final-year high school students. The search for determinants of testicular growth in childhood is important for the primary prevention of spermatogenic failure. Therefore, this retrospective study aimed to evaluate the testicular growth and pubertal onset in deficient children treated recombinant human growth hormone (rhGH). To accomplish this, the clinical charts of 93 patients with GH deficiency (GHD) were carefully reviewed. Their mean age at the time of diagnosis was 11.2 ± 2.4 years. rhGH was administered for 44.0 ± 22.4 months, and the onset of puberty was recorded after a mean of 25.8 ± 22.4 months from the first rhGH administration. As expected, serum insulin-like growth factor 1 (IGF1) levels increased significantly after treatment. Before rhGH therapy, the Tanner stage was I in 59 out of 70 boys (84.3%), II in 8/70 (11.4%), III in 3/70 (4.3%). No one was on stage IV or V. The mean Tanner stage was 1.19 ± 0.51. At the last visit, the Tanner stage was I in 8/72 boys (11.1%), II in 6/72 (8.3%), III in 6/72 (8.3%), IV in 16/72 (22.2%), and V in 36/72 (50.0%). After a mean of 44.0 ± 22.4 months of rhGH treatment, the mean Tanner stage was 4.05 ± 1.30. Patients treated with rhGH showed a significant testicular volume (TV) growth over time, whereas no growth was observed in age-matched but not yet treated patients, even when the age was compatible with a spontaneous start of puberty. The multivariate regression analysis showed that the duration of treatment and the mean rhGH dose significantly predicted the percentage of TV increase. In contrast, age, serum FSH, and IGF1 levels, and final rhGH dose did not impact TV growth over time. In conclusion, these findings suggest that GH may play a role in testicular growth and pubertal onset, despite the descriptive nature of this study. Further properly designed studies are needed to confirm these findings. This knowledge may be useful to implement the diagnostic-therapeutic algorithm in case of a lack of testicular growth in childhood.

Varicoceles

A varicocele is an abnormal venous dilatation and/or tortuosity of the pampiniform plexus in the scrotum. The exact pathophysiology of varicoceles is not very well understood, including whether there is any effect on male infertility. They can, however, be uncomfortable or painful and may result in testicular growth arrest during and prior to puberty. Varicocoeles can cause significant anxiety in patients about infertility, testicular cancer, or appearance. This article will not only discuss how to diagnose, when to investigate, and how to treat varicoceles, but also when to leave them alone.