Society has been increasingly exposed to low-frequency electromagnetic fields (EMF), mainly from electricity distribution networks and electro-electronic devices. Aiming to clarify the extension of possible interactions between EMF and testicular development, this study evaluated the effects of exposure to 60 Hz and 1 mT EMF in the maturation of testicular components. Wistar rats were exposed to EMF three times per day for 30 min, between the 13th day of gestation and the 21st postnatal day. Results showed a decrease in the following parameters: tubular diameter and seminiferous tubules area; seminiferous epithelium height; total volume of seminiferous tubule; tubular lumen; seminiferous epithelium; and Leydig cells. On the other hand, an increase was observed in connective tissue cells and blood vessels volume. Plasma testosterone, Sertoli cells population, tubular length and gonadosomatic index did not change when exposed to EMF. Histomorphometric analysis showed that exposure to EMF can promote a delay in testicular development.

Male sterilization by chemical agents is a nonsurgical contraceptive approach designed to induce azoospermia and, therefore, infertility. Intratesticular injection of zinc gluconate for sterilization of dogs has been described, but its use in cats remains limited. The objective of the present study was to evaluate, by light and transmission electron microscopy, the efficacy of a single intratesticular injection of a zinc gluconate solution (Testoblock) as a sterilant for male cats. Twelve sexually mature mixed breed cats were allocated at random into two groups (control = 6; treated = 6) and given a single injection into each testis of either isotonic saline or zinc gluconate, respectively. Histopathologic and ultrastructural evaluation was assessed at 120 days postinjection. Histopathologic changes were not detected in the testes from the control group. However, histologic evaluation of the treated group revealed atrophic and dilated seminiferous tubules, a decrease in the number of germ cells, and incomplete spermatogenesis. Sertoli cells had various degrees of cytoplasmic vacuolization. Intertubular tissue revealed active fibroblasts, collagen deposition, and inflammatory cells. The diameter of seminiferous tubules, epithelial height and tubular area were reduced (P < 0.05) in the treated group compared with controls. Azoospermia occurred in 8 of the 11 treated cats (73%). Ultrastructural evaluation of Leydig cells revealed loss of nuclear chromatin, increased smooth endoplasmatic reticulum, and mitochondria degeneration. Intratesticular injection of zinc gluconate solution impaired spermatogenesis in cats and has great potential as a permanent sterilant in this species.

The population exposure to electromagnetic fields (EMF) has been growing in recent decades. The generation, distribution and use of electric energy can generate low-frequency electromagnetic fields. The present study investigates the effects of EMF (60 Hz and 1 mT) on spermatogenesis of rats during different periods of maturation. Wistar rats were exposed to EMF from day 13 of gestation to postnatal day 21 or 90 in three daily applications of 30 min. Plasma testosterone concentration was not changed by EMF exposure; however, histopathological and histomorphometrical analyses of the testes showed testicular degeneration in a subset of animals exposed to EMF. The magnitude of the degenerative process varied between those individuals affected, indicating different individual sensitivity to EMF. The main alterations observed through transmission electron microscopy were highly electron-dense mitochondria with loss of their organization and cristae. Exposure to 60 Hz and 1 mT EMF can disturb spermatogenesis and may produce subfertility or infertility.

Objetivo: descrever as principais informações descritas na literatura acerca das informações referentes a infecção pelo coronavírus e aspectos sobre o surgimento da doença, fisiopatologia, imunologia e tratamento.  Revisão bibliográfica: A Covid-19, por meio do vírus SARS-CoV-2, apesar de ser de uma família viral conhecida até mesmo de outra pandemia no passado, possui mecanismos que precisam ser estudados para compreender com detalhes informações acerca da sua etiologia, mecanismos de infecção e tratamentos eficazes no combate da infecção. Análises microscópicas de amostras teciduais além do entendimento da imunologia aplicada à defesa viral podem ser a solução para o desenvolvimento de vacinas que consigam realizar uma proteção eficaz contra o vírus e suas mutações já conhecidas. O tratamento e as vacinas, em sua maioria, ainda se encontram em fase final de testes e sua distribuição para a população a partir da aprovação da eficácia, pode levar um bom tempo, e até lá, muitas pessoas poderão perder a vida. Considerações finais: Estudos voltados a fisiopatologia e principalmente, imunologia da SARS-CoV2 podem facilitar o desenvolvimento de terapêuticas mais eficazes e de vacinas contra a infecção do coronavírus, diminuindo o número de mortos e infectados por todo o mundo e ajudando o reestabelecimento da economia pós normalidade.

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