A clinical trial on the consistency of bilateral testicular tissue histopathology and Johnsen score: single side or bilateral side biopsy?

To evaluate and compare left and right testicular tissue histopathology and Johnsen score, and to investigate the necessity for bilateral testicular biopsy. We recruited180 patients with non-obstructiveazoospermia (NOA) on testicular biopsy who had undergonetesticular sperm aspiration (TESA). Pathological sections of testicular tissue were diagnosed by specially-assigned doctors, who evaluated pathological findings, determined the Johnsen score and confirmed for the presence or absence of sperm. Sperm positive rates for left and right testicular histopathology were 55.0% and 51.7% respectively, and the proportion of Johnsen scores≥8 for left and right testes were 53.3% and 50.0%, respectively. Cohen kappa values revealed that the identification of sperm in bilateral testicular samples was not consistent and was related to random effects; Optimized cut-off value for bilateral testicular volume was 11ml (Johnsen score ≥8), and optimized cut-off values of E2 on left and right testes were 144.5pmol/L and 133.5 pmol/L (Johnsen score≤7). However, age, serum prolactin (PRL), follicle stimulating hormone (FSH), luteinizing hormone (LH) and total testosterone (TT) levels were not accurate predictors for the existence of testicular sperm. There was nostatistical significance between left and right testicular histopathology in terms of sperm positive rates or Johnsen score; the Johnsen score were caused entirely by random effects and a score from one side could not represent the other side. Therefore, we recommend that both testes need to undergo surgery when NOA patients undergo testicular biopsy or sperm retrieval.

Ran-binding protein M is associated with human spermatogenesis and oogenesis.

The aim of the present study was to explore the underlying mechanism and diagnostic potential of Ran­binding protein M (RanBPM) in human spermatogenesis and oogenesis. RanBPM expression in human testis and ovaries was analysed using polymerase chain reaction (PCR) and western blotting, and immunofluorescence was performed on testis and ovary tissue sections during different developmental stages of spermatogenesis and oogenesis using RanBPM antibodies. Interactions with a variety of functional proteins were also investigated. RanBPM mRNA and protein expression levels were determined by PCR and western blotting in the tissue sections. Results revealed that the mRNA expression levels were highest in the testis followed by the ovary. The RanBPM protein was predominantly localized in the nucleus of germ cells, and the expression levels were highest in pachytene spermatocytes and cells surrounding spermatids in testis tissue. In ovary cells, RanBPM was localized in the nucleus and cytoplasm. In conclusion, the results suggested that RanBPM may have multiple roles in the regulation of germ cell proliferation during human spermatogenesis and oogenesis. This research may provide a novel insight into the underlying molecular mechanism of RanBPM and may have implications for the clinical diagnosis and treatment of human infertility.

[Maximum entropy principle and population genetic equilibrium].

A general mathematic model of population genetic equilibrium was constructed based on the maximum entropy principle. We proved that the maximum entropy probability distribution was equivalent to the Hardy-Weinberg equilibrium law. A population reached genetic equilibrium when the genotype entropy of the population reached the maximal possible value. In information theory, the entropy or the information content is used to measure the uncertainty of a system. In population genetics, we can use entropy to measure the uncertainty of the genotype of a population. The agreement of the maximum entropy principle and the hardy-Weinberg equilibrium law indicated that random crossing is an irreversible process, which increases the genotype entropy of the population, while inbreeding and selection decrease the genotype entropy of the population. In animal or plant breeding, we often use selection and/or inbreeding to decrease the entropy of a population, and use intercrossing to increase the entropy of the population. In this point of view, breeding is actually regulating the entropy of population. By applying the basic principle of informatics in population genetics, we revealed the biological significance of the genotype entropy and demonstrated that we can work over population genetic problems with the principles and methods of informatics and cybernetics.