Publications by authors named "Andre L Caldeira-Brant"

Some synthetic polymers can be used at low concentrations to reduce the toxicity of conventional cryoprotectant agents. In this study we investigated whether the addition of synthetic polymers to a conventional cryoprotectant solution would improve the cryopreservation of bovine ovarian tissue. Freshly collected ovaries from ten adult crossbred cows were incised using a scalpel in the frontal section.

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Caffeine is commonly consumed by pregnant women to avoid fatigue or as a habit. However, it is not clearly determined its side effects to the conceptuses. This study evaluated placental morphofunctional alterations after maternal chronic caffeine intake and the effects on fetal growth.

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Background: Cryopreservation of immature testicular tissue (ITT) is currently the only option to preserve fertility of prepubertal patients. Autologous transplantation of ITT may not be safe or appropriate for all patients. Therefore, methods to mature ITT are needed.

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Spermatogonial stem cells (SSCs) in the testis support the lifelong production of sperm. SSCs reside within specialized microenvironments called "niches," which are essential for SSC self-renewal and differentiation. However, our understanding of the molecular and cellular interactions between SSCs and niches remains incomplete.

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Numerous methods have been successfully used to evaluate mammalian spermatogonial biology However, the conventional light microscopy assays present a challenge in precisely identifying spermatogonial phenotypes, which can result in discrepancies between molecular and morphological findings. Such precise association could lead to a more robust interpretation of spermatogonial activity in steady-state spermatogenesis, which may facilitate the translation from basic research to clinical applications. In this chapter, we present two histological processing methods that enable a comprehensive analysis of spermatogonial morphology and function, involving fixation of mammalian testicular tissue in glutaraldehyde and embedding in plastic resin.

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Background: Cellular entry of SARS-CoV-2 has been shown to rely on angiotensin-converting enzyme 2 (ACE2) receptors, whose expression in the testis is among the highest in the body. Additionally, the risk of mortality seems higher among male COVID-19 patients, and though much has been published since the first cases of COVID-19, there remain unanswered questions regarding SARS-CoV-2 impact on testes and potential consequences for reproductive health. We investigated testicular alterations in non-vaccinated deceased COVID-19-patients, the precise location of the virus, its replicative activity, and the immune, vascular, and molecular fluctuations involved in the pathogenesis.

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Intrauterine growth restriction (IUGR) compromises fetal development, leading to low birth weight, and predisposes to gastrointestinal disorders. Pigs that suffered IUGR present poor postnatal development, resulting in great economic losses to the industry. The small intestine may be involved with impaired development, but studies investigating this issue are still limited.

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The present study was designed to evaluate whether tissue preparation by glutaraldehyde and glycol methacrylate (G/GMA) improves the diagnostic assessment of testicular biopsies from azoospermic men when compared to the standard tissue preparation using Bouin's solution and paraffin. We prospectively included a total of 21 testicular biopsies of sexually mature men aged 29-50 years with infertility and azoospermia. One testicular biopsy fragment from each patient was processed by the G/GMA method, whereas another tissue fragment was contemporarily processed by the conventional Bouin/paraffin (B/P) method.

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Background: Invasive micropapillary carcinoma (IMPC) is a rare malignant breast tumor and a variant form of invasive ductal carcinoma that is an aggressive neoplasm of the human breast and canine mammary gland. The importance of the tumor microenvironment in cancer development has gradually been recognized, but little is known about the cell types outlining the cystic space of canine IMPC. This study aimed to characterize the neoplastic cells outlining the cystic space of IMPC.

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Intrauterine growth restriction (IUGR) is a serious condition which impairs the achievement of the fetus' full growth potential and occurs in a natural and severe manner in pigs as a result of placental insufficiency. Reduced skeletal muscle mass in the fetus with IUGR persists into adulthood and may contribute to increased metabolic disease risk. To investigate skeletal muscle postnatal development, histomorphometrical patterns of the semitendinosus muscle, myosin heavy chain (MyHC; embryonic I, IIA, IIB and IIX isoforms) fiber composition and the relative expression of genes related to myogenesis, adipogenesis and growth during three specific periods: postnatal myogenesis (newborn to 100 days old), hypertrophy (100-150 days old), and postnatal development (newborn to 150 days old) were evaluated in female pigs with IUGR and normal birth weight (NW) female littermates.

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This study investigated the pre- and postnatal effects of protein restriction (8% vs 20% crude protein) on different parameters of spermatogenesis in adult rat offspring. Body and testis weights as well as the seminiferous tubular diameter were reduced in those animals that received the protein-restricted diet after weaning, although these parameters recovered when a 20% protein diet was offered subsequently. The numbers of spermatogonia, spermatocytes, spermatids and Leydig cells were reduced in undernourished animals, whilst the Sertoli cell number did not change.

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