ContentsThe aim of the present study was to investigate the level of information on the chemical structures and relative abundances of lipids present in cat and dog oocytes by matrixassisted laser desorption mass spectrometry (MALDI-MS). The MALDI-MS approach requires a simple analysis workflow (no lipid extraction) and few samples (two or three oocytes per analysis in this work) providing concomitant profiles of both intact phospholipids such as sphingomyelins (SM) and phosphatidylcholines (PC) as well as triacylglycerols (TAG). The lipids were detected in oocytes by MALDI using dihydroxybenzoic acid (DHB) as the matrix. The most abundant lipid present in the MS profiles of bitch and queen oocytes was a PC containing 34 carbons and one unsaturation [PC (34:1)]. Oocytes of these two species are characterized by differences in PC and TAG profiles detected qualitatively as well as by means of principal component analysis (PCA). Cat oocytes were mainly discriminated by more intense C52 and C54 TAG species and a higher number of unsaturations, indicating predominantly linoleic and oleic fatty acyl residues. Comparison of the lipid profile of bitch and queen oocytes with that of bovine oocytes revealed some similarities and also some species specificity: TAG species present in bovine oocytes were also present in bitches and queens; however, a more pronounced contribution of palmitic, stearic and oleic fatty acid residues was noticed in the lipid profile of bovine oocytes. MALDI-MS provides novel information on chemical lipid composition in canine and feline oocytes, offering a suitable tool to concomitantly monitor, in a nearly direct and simple fashion the composition of phospholipids and TAG. This detailed information is highly needed to the development of improved protocols for in vitro culture and cryopreservation of cat and dog oocytes.
Cryoinjuries severely affect the competence of vitrified oocytes (VOs) to develop into embryos after warming. The use of culture conditions that provide physical and chemical support and resemble the in vivo microenvironment in which oocytes develop, such as 3D scaffolds and coculture systems, might be useful to improve VOs outcomes. In this study, an enriched culture system of 3D barium alginate microcapsules was employed for the in vitro embryo production of domestic cat VOs. Cryotop vitrified-warmed oocytes were in vitro matured for 24 h in the 3D system with or without fresh cumulus-oocyte complexes (COCs) in coculture, whereas a control group of VOs was cultured in traditional 2D microdrops of medium. After in vitro fertilization, presumptive embryos were cultured in 3D or 2D systems according to the maturation conditions. Vitrified oocytes were able to mature and develop into embryos in 3D microcapsules (17.42 ± 11.83%) as well as in 2D microdrops (14.96 ± 8.80%), but the coculture with companion COCs in 3D resulted in similar proportions of VOs embryo development (18.39 ± 16.67%; p = 1.00), although COCs presence allowed for blastocyst formation (0.95 ± 2.52%). In conclusion, embryos until late developmental stages were obtained from cat VOs, and 3D microcapsules were comparable to 2D microdrops, but improvements in post-warming conditions are still needed.
Cryopreservation of ovarian cortex has important implications in the preservation of fertility and biodiversity in animal species. Slow freezing of cat ovarian tissue resulted in the preservation of follicular morphology and in the follicular development after xenografting. Vitrification has been recently applied to ovarian tissues of different species, but no information is available on the effect of this method on feline ovarian cortex. Moreover, meiotic competence of fully grown oocytes isolated from cryopreserved tissue has not been reported. The aim of this study was to evaluate the effect of vitrification of feline ovarian cortex on follicular morphology and oocyte integrity, as well as meiotic competence. A total of 352 fragments (1.5-2 mm(3) ) were obtained from ovarian cortical tissues: 176 were vitrified and 176 were used fresh as control. Histological evaluation of fresh and vitrified fragments showed intact follicles after cryopreservation procedures with no statistically significant destructive effect from primordial to antral follicles. After IVM, oocytes collected from vitrified ovarian fragment showed a higher proportion of gametes arrested at germinal vesicle (GV) stage compared to those isolated from fresh control tissue (33.8% vs 2.9%; p < 0.001). However, oocytes isolated from vitrified tissues were able to resume meiosis, albeit at lower rate than those collected from fresh tissues (39.8% vs 85.9%; p < 0.00001). Vitrification induced changes in the organization of cytoskeletal elements (actin microfilaments and microtubules) of oocytes, but significantly only for actin network (p < 0.001). Finally, chromatin configuration within the GV was not affected by the cryopreservation procedure. Our study demonstrated that vitrification preserves the integrity of ovarian follicles and that oocytes retrieved from cryopreserved tissue maintain the capability of resuming meiosis. To our knowledge, this has not previously been reported in the cat.
A próstata é a única glândula sexual nos cães e, embora seja encontrada em todos os mamíferos, sua importância clínica é maior no homem e nesta espécie animal devido à quantidade de afecções que os acometem. Diversas técnicas cirúrgicas têm sido utilizadas para o tratamento de cistos e abscessos prostáticos em cães, e há alguns anos foi relatado o primeiro uso da técnica de omentalização prostática para o tratamento de cistos e abscessos, com sucesso efetivo, e até o momento, não há informações de seu emprego no Brasil. Sendo assim, este trabalho teve como objetivo avaliar a recuperação e o período pós-operatório de animais submetidos a esta técnica, durante o período de 2002 a 2004. Foram estudados 17 machos, sendo 11 com cistos prostáticos, 4 com abscesso e 2 com cisto paraprostático. Quinze se recuperaram sem complicações, enquanto um apresentou incontinência urinária por dois dias após a cirurgia. Um animal veio a óbito em decorrência de septicemia preexistente. A baixa incidência de complicações e o curto período de hospitalização fazem da omentalização a cirurgia de escolha para o tratamento de abscessos e cistos prostáticos em cães.
Despite being valuable resources for fertility preservation purposes of wild and endangered felids, cat (Felis silvestris catus) vitrified oocytes (VOs) poorly achieve full maturation after warming because their intrinsic competence is severely impaired by unavoidable cryodamages that also involve their surrounding cumulus cells (Luvoni, 2006). Modifications to media composition or supplementation with supporting cells alone have not led to truly satisfactory results, and therefore, since physical factors can positively influence the chemical conditions (Luvoni, Colombo, & Morselli, 2018), three-dimensional (3D) follicle-like structures could enhance meiosis resumption and further embryo development in vitro of poorly competent oocytes.
The physiological parameters that could be reference for trustful diagnosis and prognosis of prostate disorders in dogs were obtained. Thirty six intact male dogs without clinical signs of neither prostatic nor reproductive disorders were allocated according the age in three groups. These animals were submitted to semen manual collection for microbiological exams; transabdominal ultrasonography to evaluate dimensions, ecogenicity, and texture of prostatic parenchyma and aspirative puncture with fine needle for cytological and microbiological analyses. Ultrasonography revealed that the predominant prostatic shape was round with regular surface. Dimensions varied according to age, being small in young animals and large in old ones. There was a positive correlation between prostatic dimensions and body weight. Microbiological exams detected microorganisms on seminal plasma from 11 dogs and prostate tissue aspirated from 10 animals, although they were healthy. Cytology did not reveal any inflammatory, proliferative, or neoplasic alteration in young and middle age dogs, but in three older dogs signs of hyperplasia/hypertrophy was found. It was observed positive correlation between age and cellular area but a negative correlation was observed between nucleus:cytoplasm ratio and craniocaudal dimension.
The aim of this study was to evaluate the suitability of a commercial kit for bovine embryo vitrification for cryopreserving cat oocytes and to evaluate comparatively the effects of its use with slow freezing procedure on cryotolerance in terms of morphology and oocyte resumption of meiosis. Germinal vesicle stage oocytes isolated from cat ovaries were either vitrified (n = 72) using a vitrification kit for bovine embryo or slow frozen (n = 69) by exposing oocyte to ethylene glycol solution before being transferred to a programmable embryo freezer. After thawing and warming, oocytes were cultured for 48 h and then were examined for meiosis resumption using bisbenzimide fluorescent staining (Hoechst 33342). Fresh immature oocytes (n = 92) were used as the control group. The proportion of oocytes recovered in a morphologically normal state after thawing/warming was significantly higher in frozen oocytes (94.5%) than in the vitrified ones (75%, p < 0.01). Morphological integrity after culture was similar in vitrified (73.6%) and slow frozen oocytes (76.8%); however, only 37.5% of the morphologically normal oocytes resumed meiosis after vitrification compared to 60.9% of those submitted to slow freezing procedure (p < 0.01). Fresh oocytes showed higher morphological integrity (91.3%) and meiosis resumption rates (82.6%, p < 0.002) than cryopreserved oocytes, irrespective of the procedure used. These results suggest that immature cat oocytes vitrified with a kit for bovine embryos retain their capacity to resume meiosis after warming and culture, albeit at lower rates than slow frozen oocytes. Vitrification and slow freezing methods show similar proportions of oocytes with normal morphology after culture, which demonstrate that thawed and warmed oocytes that resist to cryodamage have the same chances to maintain their integrity after 48 h of culture.
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