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Background: The ovarian tissue cryopreservation has been achieved a great notoriety in the Reproductive Biology area, due to its potential in preserving female fertility through the protection of exocrine and endocrine functions of the ovary. The association of this technique with in vitro culture and/or transplant in adult or young individuals who has not initiated its reproductive activities represents not only the conservation and perpetuation of the genetic material of economic valuable animals, but also the preservation of female gametes from endangered species, or even from young women who may have ovarian dysfunctions caused by gonadotoxic treatments. Studies with some species (human, mice and ovine) have demonstrated the recovery of the ovarian function and the birth of healthy offspring after transplant of ovarian tissue which has been previously cryopreserved. However, most studies have shown that ovarian cryopreservation process offer risks to different structures (follicle and stroma) as well as to the different cell types (oocyte, granulosa, thecal and stromal cells), which constitute this tissue. Review: Extreme cold, intracellular ice crystallization, osmotic shock and the toxicity of the cryoprotectant agents are factors that are usually associated with the injuries caused by the cryopreservation process. As a direct or indirect consequence, those factors limit the success of the cryopreservation of ovarian tissue, since they affect the survival or alter the tissue functionality or cellular structure, like the ovarian follicles, for example, after the thawing/warming procedure. Among the injuries that may take place as a consequence of those factors, we can mention: cell death by the necrotic or apoptotic pathways; alterations in N normal levels of genic expression; ischemia and changes of communication and interaction between the oocyte and follicular cells. As a result, many authors have studied and developed protocols of cryopreservation that may prevent or minimize the cryoinjuries, since the cryopreservation per si or combined to other techniques (in vitro culture and/or transplant) can compromise the ovarian integrity, leading consequently to a significant loss of follicles. In this regard, the present review seeks to approach the advantages of the cryopreservation of ovarian tissue; indicating the difficulties and challenges that encompass this procedure, with purpose of pointing out solutions to overcome the damages of ovarian tissue cryopreservation, through of convenient cryopreservation protocols that avoid those follicular losses. For this purpose, it is necessary the preservation of the follicular viability as well as the preservation of the tissue integrity and the contact between reproductive (oocytes) or somatic cells, which are essentials to the follicle development, and, consequently, to the embryo production. Conclusion: The use of cryopreserved ovarian tissue is an important strategy to the preservation of female fertility. This tool has being pointed as an alternative way to the cryopreservation of mature oocytes and embryos. However, additional studies are necessary to diminishing the cellular damages inherent to this procedure, especially those related to the comprehension of the obstacles and mechanisms associated to the exposition to extreme cold. [ABSTRACT FROM AUTHOR]

Cystic Fibrosis is an autosomal recessive disease, which manifests early in childhood and despite treatment that has evolved over the years by increasing life expectancy, it is still lethal. Caused by some disorder of exocrine glands and the epithelial lining of the treatment: respiratory, gastrointestinal and reproductive systems. Basically the primary defect is in the regulation of epithelial chloride transport, causing excessive accumulation and may lead to serious and irreversible damage to the tissue where it is present as intestinal obstruction, male infertility, pancreatic dysfunction. In the respiratory tract promotes favorable conditions for frequent infections and/or chronic lung disease, also affects the nutritional status by interfering with the intake and food absorption, causing disproportionate development age of the child or adolescent. Cystic Fibrosis in history, there has been little advance in treatment compared to the time when there were his early records. But despite having no cure, advances that occurred over time allow people with the disease increased survival time. Concluding that the best way to ensure maximum survival and quality of life, where possible, is to discover and initiate early treatment to avoid its more serious complications and irreversible damage to the well being of patients as a whole and family. [ABSTRACT FROM AUTHOR]

The immunity in the mammary gland can be, as in other systems, classified in innate or adaptive immunity. The innate immunity is the predominant defense during the initial periods of infection. The non-specifics answers are present or are quickly activated in the infection's site by numerous stimulations, and these answers are not enhanced by repeated exposure to the same agent. The first obstacle to be faced by the agent is the barrier represented by the teat sphincter and the keratin plug. When the pathogenic agent crosses the teat canal and reaches the teat cistern, starts to act the humoral factors and the phagocytic cells starts do act. Among the humoral mediators there are the lactoperoxidase, complement, cytokines, lactoferrin, lysozyme and NAGase. The non-specific cellular defenses are represented by neutrophils, macrophages and natural killer cells. If these mechanisms have been functioning adequately, the majority of pathogens will be eliminated in a short time, before the specific immune system be activated. The fast elimination of the microorganisms will not allow these alterations in the amount or quality of produced milk. The best understanding of the defense mechanisms of the mammary gland and its alterations during the critical periods of infection, is an useful tool in devising and developing methods to control the mastitis, the major illness of dairy ruminants. This paper overviewed the most important aspects of the innate immunity of bovine mammary gland. [ABSTRACT FROM AUTHOR]