scholarly journals Recent Progress in Cryopreservation of Bovine Oocytes

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
In-Sul Hwang ◽  
Shinichi Hochi

Principle of oocyte cryoinjury is first overviewed and then research history of cryopreservation using bovine oocytes is summarized for the last two decades with a few special references to recent progresses. Various types of cryodevices have been developed to accelerate the cooling rate and applied to the oocytes from large domestic species enriched with cytoplasmic lipid droplets. Two recent approaches include the qualitative improvement of IVM oocytes prior to the vitrification and the short-term recovery culture of vitrified-warmed oocytes prior to the subsequent IVF. Supplementation of L-carnitine to IVM medium of bovine oocytes has been reported to reduce the amount of cytoplasmic lipid droplets and improve the cryotolerance of the oocytes, but it is still controversial whether the positive effect of L-carnitine is reproducible. Incidence of multiple aster formation, a possible cause for low developmental potential of vitrified-warmed bovine oocytes, was inhibited by a short-term culture of the postwarm oocytes in the presence of Rho-associated coiled-coil kinase (ROCK) inhibitor. Use of an antioxidantα-tocopherol, instead of the ROCK inhibitor, also supported the revivability of the postwarm bovine oocytes. Further improvements of the vitrification procedure, combined with pre- and postvitrification chemical treatment, would overcome the high sensitivity of bovine oocytes to cryopreservation.

Zygote ◽  
2015 ◽  
Vol 24 (1) ◽  
pp. 115-120 ◽  
Author(s):  
H. Hara ◽  
M. Tagiri ◽  
M. Hirabayashi ◽  
S. Hochi

SummaryWe have recently reported that multiple aster formation after in vitro fertilization (IVF) was one of the factors that negatively affected the developmental competence of vitrified-warmed bovine matured oocytes, and that short-term culture of the post-warm oocytes with an inhibitor of Rho-associated coiled-coil kinase (ROCK) suppressed the multiple aster formation and improved the blastocyst yield. The present study was conducted to investigate whether increased multiple aster formation following IVF was involved in impaired developmental competence of stored ovary-derived bovine oocytes. Oocytes retrieved from 1-day stored ovaries had lower developmental potential to day 8 blastocysts when compared with those from fresh ovaries (37 versus 63%). Immunostaining of α-tubulin 10 h post-IVF revealed that a higher incidence of multiple aster formation occurred in oocytes retrieved from stored ovaries than from fresh ovaries (31 versus 15%). Treatment of post-in vitro maturated (post-IVM) oocytes with ROCK inhibitor for 2 h significantly suppressed the incidence of multiple aster formation (10 versus 32% in the control group). However, the suppression effect of ROCK inhibitor on multiple aster formation in IVM/IVF oocytes did not improve blastocyst yield from stored ovary-derived oocytes (41 versus 37% in the control group). These results suggested that the higher incidence of multiple aster formation by bovine ovary storage was not responsible for the decreased developmental competence of IVF oocytes.


Author(s):  
D.N. Collins ◽  
J.N. Turner ◽  
K.O. Brosch ◽  
R.F. Seegal

Polychlorinated biphenyls (PCBs) are a ubiquitous class of environmental pollutants with toxic and hepatocellular effects, including accumulation of fat, proliferated smooth endoplasmic recticulum (SER), and concentric membrane arrays (CMAs) (1-3). The CMAs appear to be a membrane storage and degeneration organelle composed of a large number of concentric membrane layers usually surrounding one or more lipid droplets often with internalized membrane fragments (3). The present study documents liver alteration after a short term single dose exposure to PCBs with high chlorine content, and correlates them with reported animal weights and central nervous system (CNS) measures. In the brain PCB congeners were concentrated in particular regions (4) while catecholamine concentrations were decreased (4-6). Urinary levels of homovanillic acid a dopamine metabolite were evaluated (7).Wistar rats were gavaged with corn oil (6 controls), or with a 1:1 mixture of Aroclor 1254 and 1260 in corn oil at 500 or 1000 mg total PCB/kg (6 at each level).


1996 ◽  
Vol 45 (1) ◽  
pp. 180 ◽  
Author(s):  
H. Nagashima ◽  
M. Kuwayama ◽  
C.G. Grupen ◽  
R.J. Ashman ◽  
M.B. Nottle

2016 ◽  
Vol 62 (2) ◽  
pp. 360-366 ◽  
Author(s):  
Emily I Schindler ◽  
Jeffrey J Szymanski ◽  
Karl G Hock ◽  
Edward M Geltman ◽  
Mitchell G Scott

Abstract BACKGROUND Galectin-3 (Gal-3) has been suggested as a prognostic biomarker in heart failure (HF) patients that may better reflect disease progression than traditional markers, including B-type natriuretic peptide (BNP) and cardiac troponins. To fully establish the utility of any biomarker in HF, its biologic variability must be characterized. METHODS To assess biologic variability, 59 patients were prospectively recruited, including 23 male and 16 female patients with stable HF and 10 male and 10 female healthy individuals. Gal-3, BNP, and high-sensitivity cardiac troponin I (hs-cTnI) were assayed at 5 time points within a 3-week period to assess short-term biologic variability. Long-term (3-month) biologic variability was assessed with samples collected at enrollment and after 4, 8, and 12 weeks. RESULTS Among healthy individuals, mean short-term biologic variability, expressed as intraindividual CV (CVI), was 4.5% for Gal-3, 29.0% for BNP, and 14.5% for hs-cTnI; long-term biologic variability was 5.5% for Gal-3, 34.7% for BNP, and 14.7% for hs-cTnI. In stable HF patients, mean short-term biologic variability was 7.1% for Gal-3, 22.5% for BNP, and 8.5% for hs-cTnI, and mean long-term biologic variability was 7.7% for Gal-3, 27.6% for BNP, and 9.6% for hs-cTnI. CONCLUSIONS The finding that Gal-3 has minimal intraindividual biological variability adds to its potential as a useful biomarker in HF patients.


2018 ◽  
Vol 315 (4) ◽  
pp. R656-R667 ◽  
Author(s):  
Wen Yu Wong ◽  
Maricela Pier ◽  
Kirsten H. Limesand

Xerostomia and hyposalivation are debilitating side effects for patients treated with ionizing radiation for head and neck cancer. Despite technological advances, collateral damage to the salivary glands remains a significant problem for patients and severely diminishes their quality of life. During the wound healing process, restoration of junctional contacts is necessary to maintain polarity, structural integrity, and orientation cues for secretion. However, little is known about whether these structural molecules are impacted following radiation damage and more importantly, during tissue restoration. We evaluated changes in adherens junctions and cytoskeletal regulators in an injury model where mice were irradiated with 5 Gy and a restoration model where mice injected postradiation with insulin-like growth factor 1 (IGF1) are capable of restoring salivary function. Using coimmunoprecipitation, there is a decrease in epithelial (E)-cadherin bound to β-catenin following damage that is restored to untreated levels with IGF1. Via its adaptor proteins, β-catenin links the cadherins to the cytoskeleton and part of this regulation is mediated through Rho-associated coiled-coil containing kinase (ROCK) signaling. In our radiation model, filamentous (F)-actin organization is fragmented, and there is an induction of ROCK activity. However, a ROCK inhibitor, Y-27632, prevents E-cadherin/β-catenin dissociation following radiation treatment. These findings illustrate that radiation induces a ROCK-dependent disruption of the cadherin-catenin complex and alters F-actin organization at stages of damage when hyposalivation is observed. Understanding the regulation of these components will be critical in the discovery of therapeutics that have the potential to restore function in polarized epithelium.


2018 ◽  
Vol 17 (2) ◽  
pp. 783-810
Author(s):  
Angélica Pott de Medeiros ◽  
Giulia Xisto de Oliveira ◽  
Reisoli Bender Filho

Resumo: O cenário de instabilidade política, a recessão econômica e as mudanças nas regras de concessão de crédito pautaram o objetivo de examinar o relacionamento do crédito consignado, por segmento de concessão, com variáveis macroeconômicas, caso do consumo, da produção industrial e do produto agregado, na última década (2007-2017). Os resultados foram obtidos por meio da estimação do vetor de correção de erros, funções de impulso-resposta e decomposição da variância, possibilitando a análise das relações de curto e de longo prazo entre as séries temporais e indicaram que as diferentes modalidades do crédito consignado implicam efeitos distintos sobre as variáveis econômicas em curto prazo. O segmento de aposentados e pensionistas impacta positivamente ambas as variáveis analisadas, com destaque para os bens de consumo das famílias. Já a concessão ao setor privado, embora represente a menor parcela do crédito consignado concedido, mostrou elevada sensibilidade a alterações na oferta dessa modalidade de crédito, enquanto que o crédito ao setor público, de maior participação, apresentou efeitos reduzidos e de curta duração.Palavras-chave: Crédito consignado. Segmentos. Economia brasileira. Payroll loans: segments and economic effects Abstract: The environment of political instability, economic recession and changes in the rules of granting credit were guiders to aim to examine the payroll loans relationship, by concession segment, with macroeconomic variables, case of consumption, industrial production and aggregate product, in the last decade (2007-2017). The results obtained by error correction vector estimation, and functions of impulse-response and variance decomposition, making it possible to analyze the short- and long-term relationships between the time series and indicated that the different modalities of payroll loans imply different effects on economic short-term variables. With retirees and pensioners segment positively impact on both analyzed variables, highlighting the household consumption goods. The concession to the private sector, although it represents the smallest portion of payroll loans granted, it showed high sensitivity to the changes of this modality. About credit to the public sector, which has the biggest portion, it showed reduced and short-term effects.Keywords: Payroll loans. Segments. Brazilian economy.


2020 ◽  
Author(s):  
José Tuñón ◽  
Álvaro Aceña ◽  
Ana Pello ◽  
Sergio Ramos-Cillán ◽  
Juan Martínez-Milla ◽  
...  

Abstract Background N-terminal pro-brain natriuretic peptide (NT-proBNP) plasma levels are increased in patients with cancer. In this paper we test whether NT-proBNP may identify patients who are going to receive a future cancer diagnosis (CD) in the short term. Methods We studied 962 patients with stable coronary artery disease and free of cancer and heart failure at baseline. NT-proBNP, galectin-3, monocyte chemoattractant protein-1, high-sensitivity C-reactive protein, high-sensitivity cardiac troponin I (hsTnI), and calcidiol (vitamin D) plasma levels were assessed. The primary outcome was new CD. Results After 5.40 (2.81-6.94) years of follow-up, 59 patients received a CD. NT-proBNP [HR 1.036 CI (1.015-1.056) per increase in 100 pg/ml; p=0.001], previous atrial fibrillation [HR 3.140 CI (1.196-8.243); p=0.020], and absence of previous heart failure [HR 0.067 CI (0.006-0.802); p=0.033] were independent predictors of a receiving a CD in first three years of follow-up. None of the variables analyzed predicted a CD beyond this time. A previous history of heart failure was present in 3.3% of patients receiving a CD in the first three years of follow-up, in 0.0% of those receiving this diagnosis beyond three years, and in 12.3% of patients not developing cancer (p=0.036). Conclusions In patients with coronary artery disease, NT-proBNP is an independent predictor of CD in the first three years of follow-up but not later, suggesting that it could be detecting subclinical undiagnosed cancers. The existence of previous heart failure does not account for these differences. New studies in large populations are needed to confirm these findings.


2017 ◽  
Vol 29 (9) ◽  
pp. 1821 ◽  
Author(s):  
Shuang Liang ◽  
Jing Guo ◽  
Jeong-Woo Choi ◽  
Nam-Hyung Kim ◽  
Xiang-Shun Cui

After reaching the metaphase II (MII) stage, unfertilised oocytes undergo a time-dependent process of quality deterioration referred to as oocyte aging. The associated morphological and cellular changes lead to decreased oocyte developmental potential. This study investigated the effect of exogenous melatonin supplementation on in vitro aged bovine oocytes and explored its underlying mechanisms. The levels of cytoplasmic reactive oxygen species and DNA damage response in bovine oocytes increased during in vitro aging. Meanwhile, maturation promoting factor activity significantly decreased and the proportion of morphologically abnormal oocytes significantly increased. Melatonin supplementation significantly decreased quality deterioration in aged bovine MII oocytes (P < 0.05). Additionally, it decreased the frequency of aberrant spindle organisation and cortical granule release during oocyte aging (P < 0.05). In the melatonin-supplemented group, mitochondrial membrane potential and ATP production were significantly increased compared with control. Furthermore, melatonin treatment significantly increased the speed of development of bovine oocytes to the blastocyst stage after in vitro fertilisation and significantly decreased the apoptotic rate in the blastocysts (P < 0.05). The expression of Bax and Casp3 in the blastocysts was significantly reduced after treatment with melatonin, whereas expression of Bcl2 significantly increased (P < 0.05). In conclusion, these findings suggest that supplementation of aged bovine oocytes with exogenous melatonin improves oocyte quality, thereby enhancing the developmental capacity of early embryos.


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