Histological and ultrastructural analysis of cryopreserved sheep preantral follicles

The aim of this study was to verify the histological and ultrastructural characteristics of sheep preantral follicles after exposure of ovarian tissue to cryopreservation in glycerol (GLY), ethylene glycol (EG), propanediol (PROH) or dimethyl sulfoxide (DMSO) in order to determine the optimum method to store sheep ovarian tissue for later experimental or clinical use. Each ovarian pair from five mixed-breed ewes was divided into 17 fragments. One (control) fragment was immediately fixed for routine histological and ultrastructural studies and the remaining (test) fragments were randomly distributed in cryotubes, equilibrated at 20 °C/20 min in 1.8 mL of minimal essential medium (MEM) containing 1.5 or 3 M GLY, EG, PROH or DMSO and then either fixed for morphological studies to determine their possible toxic effect or frozen/thawed and then fixed to test the effect of cryopreservation on preantral follicles. Histological analysis showed that, compared to control fragments, all cryoprotectants at both concentrations significantly reduced the percentage of normal preantral follicles in ovarian fragments prior to or after cryopreservation. PROH 3.0 M appeared to exert a more toxic effect (P < 0.05) than the other cryoprotectants in noncryopreserved tissues. After freezing/thawing, the highest (P < 0.05) percentages of lightmicroscopical normal preantral follicles were observed in ovarian fragments cryopreserved in EG (1.5 and 3 M) or DMSO (1.5 M). However, transmission electronic microscopical (TEM) examination showed that only the DMSO-cryopreserved preantral follicles had normal ultrastructure. The data suggest that sheep preantral follicles should be cryopreserved with 1.5 M DMSO for later clinical or experimental application

The Balanced Scorecard - як основа прийняття управлінських рішень

Frozen-thawed ovarian cortical fragments (1 mm(3)) were autotransplanted to the uterus of completely ovariectomized goats. The grafts developed preovulatory follicles, accompanied by estrous behavior and a rise in plasma E(2) levels, demonstrating successful cryopreservation and transplantation

Osmotic tolerance and freezability of isolated caprine early-staged follicles

Isolated caprine early-staged follicles were submitted to osmotic tolerance tests in the presence of sucrose, ethylene glycol (EG), or NaCl solutions and were exposed to and cryopreserved (by slow or rapid cooling) in MEM alone or MEM supplemented with sucrose, EG (1.0 or 4.0 M), or both. When follicles were exposed to 1.5 M NaCl, only 2% of the follicles were viable, whereas 87% of the follicles were viable after exposure to 4.0 M EG. Regarding exposure time, the highest percentage of viable follicles was obtained when follicles were exposed for 10 min to 1.0 M EG + 0.5 M sucrose; exposure for 60 s to 4.0 M EG + 0.5 M sucrose also maintained high percentage viability in follicles. Slow cooling in the presence of 1.0 M EG + 0.5 M sucrose (75%) or rapid cooling in the presence of 4.0 M EG + 0.5 M sucrose (71%) resulted in a significantly higher proportion of viable follicles than all other treatments (P < 0.05). A 24-h culture of frozen-thawed follicles was used to assess survival; only slow-frozen follicles showed viability rates similar to control follicles (64% vs. 69% respectively; P > 0.05). Interestingly, the percentage of viable rapid-cooled follicles (59%) was similar to that obtained after in vitro culture of conventional slow-cooled follicles but was significantly lower than that in controls. Thus, in addition to determining improved procedures for the exposure of follicles to EG and sucrose before and after freezing of caprine early-staged follicles, we report the development of rapid- and slow-cooling protocols

Long-term Exposure to Traffic-related Air Pollution and Type 2 Diabetes Prevalence in a Cross-sectional Screening-study in the Netherlands

<p>Abstract</p> <p>Background</p> <p>Air pollution may promote type 2 diabetes by increasing adipose inflammation and insulin resistance. This study examined the relation between long-term exposure to traffic-related air pollution and type 2 diabetes prevalence among 50- to 75-year-old subjects living in Westfriesland, the Netherlands.</p> <p>Methods</p> <p>Participants were recruited in a cross-sectional diabetes screening-study conducted between 1998 and 2000. Exposure to traffic-related air pollution was characterized at the participants' home-address. Indicators of exposure were land use regression modeled nitrogen dioxide (NO₂) concentration, distance to the nearest main road, traffic flow at the nearest main road and traffic in a 250 m circular buffer. Crude and age-, gender- and neighborhood income adjusted associations were examined by logistic regression.</p> <p>Results</p> <p>8,018 participants were included, of whom 619 (8%) subjects had type 2 diabetes. Smoothed plots of exposure versus type 2 diabetes supported some association with traffic in a 250 m buffer (the highest three quartiles compared to the lowest also showed increased prevalence, though non-significant and not increasing with increasing quartile), but not with the other exposure metrics. Modeled NO₂-concentration, distance to the nearest main road and traffic flow at the nearest main road were not associated with diabetes. Exposure-response relations seemed somewhat more pronounced for women than for men (non-significant).</p> <p>Conclusions</p> <p>We did not find consistent associations between type 2 diabetes prevalence and exposure to traffic-related air pollution, though there were some indications for a relation with traffic in a 250 m buffer.</p

Comprehensive Rare Variant Analysis via Whole-Genome Sequencing to Determine the Molecular Pathology of Inherited Retinal Disease

Inherited retinal disease is a common cause of visual impairment and represents a highly heterogeneous group of conditions. Here, we present findings from a cohort of 722 individuals with inherited retinal disease, who have had whole-genome sequencing (n = 605), whole-exome sequencing (n = 72), or both (n = 45) performed, as part of the NIHR-BioResource Rare Diseases research study. We identified pathogenic variants (single-nucleotide variants, indels, or structural variants) for 404/722 (56%) individuals. Whole-genome sequencing gives unprecedented power to detect three categories of pathogenic variants in particular: structural variants, variants in GC-rich regions, which have significantly improved coverage compared to whole-exome sequencing, and variants in non-coding regulatory regions. In addition to previously reported pathogenic regulatory variants, we have identified a previously unreported pathogenic intronic variant in $\textit{CHM}$ in two males with choroideremia. We have also identified 19 genes not previously known to be associated with inherited retinal disease, which harbor biallelic predicted protein-truncating variants in unsolved cases. Whole-genome sequencing is an increasingly important comprehensive method with which to investigate the genetic causes of inherited retinal disease.This work was supported by The National Institute for Health Research England (NIHR) for the NIHR BioResource – Rare Diseases project (grant number RG65966). The Moorfields Eye Hospital cohort of patients and clinical and imaging data were ascertained and collected with the support of grants from the National Institute for Health Research Biomedical Research Centre at Moorfields Eye Hospital, National Health Service Foundation Trust, and UCL Institute of Ophthalmology, Moorfields Eye Hospital Special Trustees, Moorfields Eye Charity, the Foundation Fighting Blindness (USA), and Retinitis Pigmentosa Fighting Blindness. M.M. is a recipient of an FFB Career Development Award. E.M. is supported by UCLH/UCL NIHR Biomedical Research Centre. F.L.R. and D.G. are supported by Cambridge NIHR Biomedical Research Centre

A formação de professores em perspectivas internacionais: estudo comparado entre modelos europeus e brasileiro

During early embryonic development, pig and chicken embryos share striking morphological similarities. In the present study, the timing and location of expression of mRNA for goosecoid (gsc), a gene classically expressed in the nodal region of developing embryos, was examined and compared in preprimitive streak and gastrulating pig and chicken embryos. The expression of gsc appeared first in the hypoblast and second in the hypoblast of pig and chicken embryos. Because gsc expression in these tissues was not symmetrical, gsc appears to be a useful marker for the onset of embryonic polarity. During gastrulation in both species, gsc expression became confined to cells in and around the node, in the epiblast and mesoderm layers. The only significant species-related difference in the distribution of gsc expression at these stages of development was the presence of gsc expression in the gut endoderm of chicken but not pig embryos. Certainly, our results suggest that the molecular mechanisms that control anterior–posterior development in different classes of vertebrates are remarkably similar. In addition, we were able to demonstrate that the pattern of gsc expression appears to provide a more sensitive and accurate means of determining the developmental stage of early porcine embryos than the more commonly used trophoblast or embryoblast size. Using gsc expression and accompanying embryo morphometric changes, we were able to develop a four-point scale that may offer a more accurate means of quantifying early embryo development in pigs

Biosynthesis and differential processing of two pools of APP in a physiologically inducible neuroendocrine cell.

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