scholarly journals Follicle Structure Influences the Availability of Oxygen to the Oocyte in Antral Follicles

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
A. R. Clark ◽  
Y. M. Stokes
Keyword(s):  
Mathematical Model ◽  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Oxygen Transport ◽  
Follicular Fluid ◽  
Antral Follicle ◽  
Antral Follicles ◽  
Cumulus Oocyte Complex ◽  
The Mean ◽  
Size And Structure

The ability of an oocyte to successfully mature is highly dependent on intrafollicular conditions, including the size and structure of the follicle. Here we present a mathematical model of oxygen transport in the antral follicle. We relate mean oxygen concentration in follicular fluid of bovine follicles to the concentration in the immediate vicinity of the cumulus-oocyte complex (COC). The model predicts that the oxygen levels within the antral follicle are dependent on the size and structure of the follicle and that the mean level of dissolved oxygen in follicular fluid does not necessarily correspond to that reaching the COC.

Prediction of dissolved oxygen concentration along sanitary sewers

1996 ◽  
Vol 34 (5-6) ◽  
pp. 525-532 ◽  
Author(s):  
J. Saldanha Matos ◽  
E. Ribeiro de Sousa
Keyword(s):  
Mathematical Model ◽  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Oxygen Transfer ◽  
Oxygen Balance ◽  
Dissolved Oxygen Concentration ◽  
Empirical Expression ◽  
Slime Layer ◽  
Sanitary Sewers ◽  
The Mathematical Model

The oxygen balance in wastewater collection systems is important in respect to the degree of biological oxidation that occurs within the stream and in respect to the control of septicity and its effects. In this paper, a simple mathematical model is presented, in order to predict dissolved oxygen concentration profiles along sanitary sewers. The mathematical model was developed based on an analytical solution of the simple differential equation of dissolved oxygen balance in sewers, and includes an empirical expression for prediction of dissolved oxygen transfer to the slime layer on the pipe walls. Because the factors controlling dissolved oxygen balance in sewers are so complex, it would be unrealistic to expect, that with this rather simple model, dissolved oxygen concentrations can be accurately predicted. Nevertheless, it is reasonable to suppose that the predictions may be adequate for some design and operation purposes.

scholarly journals Mathematical modelling of oxygen concentration in bovine and murine cumulus–oocyte complexes

Reproduction ◽  
2006 ◽  
Vol 131 (6) ◽  
pp. 999-1006 ◽  
Author(s):  
A R Clark ◽  
Y M Stokes ◽  
M Lane ◽  
J G Thompson
Keyword(s):  
Mathematical Model ◽  
Oxygen Consumption ◽  
Oxygen Concentration ◽  
Consumption Rate ◽  
Cumulus Cells ◽  
Common Boundary ◽  
Nonlinear Variation ◽  
Cumulus Oocyte Complex ◽  
Atp Generation ◽  
Metabolic Data

Immature oocytes benefit from nutrient modification of the follicular environment by the surrounding cumulus mass. However, the oxygen concentration that the oocyte may be exposed to could be lower than the antral follicular concentration due to the metabolism of surrounding cumulus cells. Using metabolic data previously determined, we have developed a mathematical model of O2diffusion across the bovine and murine cumulus–oocyte complex. From this we have determined that across a physiological range of external pO2, less than 0.25% and 0.5% O2is removed by cumulus cells within the bovine and murine cumulus–oocyte complex respectively. Our model differs from others as it: incorporates a term that allows for nonlinear variation of the oxygen consumption rate with oxygen concentration; considers two regions (oocyte and cumulus) sharing a common boundary, both of which consume oxygen at different non linear rates. Cumulus cells therefore remove little O2, thus sparing this essential gas for the oocyte, which is dependent on ATP generation via oxidative phosphorylation.

Numerical Simulation of Plug Discharge with Dissolved Oxygen Convection and Diffusion

2012 ◽  
Vol 433-440 ◽  
pp. 1920-1925
Author(s):  
Ze Gao Yin ◽  
Le Wang ◽  
Jin Xiong Zhang ◽  
Xian Wei Cao
Keyword(s):  
Mathematical Model ◽  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Dissipation Rate ◽  
Concentration Distribution ◽  
Coupled Model ◽  
Computational Results ◽  
Dissolved Oxygen Concentration ◽  
Velocity Pressure ◽  
And Diffusion

In Fluent, the 3-D RNG k- ξ mathematical model is employed to compute the plug discharge, and dissolved oxygen convection and diffusion model is established to simulate the concentration distribution of dissolved oxygen with user defined scalar method. Velocity, pressure, turbulence kinetic energy, turbulence dissipation rate and dissolved oxygen concentration are computed. Then, velocity, pressure and dissolved oxygen concentration are compared with the data of physical model, and they agree with each other approximately, showing it is valid and reliable to compute the plug discharge and dissolved oxygen concentration with the coupled model. Furthermore, the characteristics of hydraulic factors including dissolved oxygen concentration are analyzed and generalized based on the computational results.

scholarly journals Profiling of superoxide dismutase isoenzymes in compartments of the developing bovine antral follicles

Reproduction ◽  
2010 ◽  
Vol 139 (5) ◽  
pp. 871-881 ◽  
Author(s):  
Catherine M H Combelles ◽  
Emily A Holick ◽  
Louis J Paolella ◽  
David C Walker ◽  
Qiaqia Wu
Keyword(s):  
Superoxide Dismutase ◽  
Granulosa Cells ◽  
Follicular Fluid ◽  
Follicular Development ◽  
Cumulus Cells ◽  
Antral Follicle ◽  
Supporting Evidence ◽  
Sod Activity ◽  
Antral Follicles ◽  
Sod Isoforms

The antral follicle constitutes a complex and regulated ovarian microenvironment that influences oocyte quality. Oxidative stress is a cellular state that may play a role during folliculogenesis and oogenesis, although direct supporting evidence is currently lacking. We thus evaluated the expression of the three isoforms (SOD1, SOD2, and SOD3) of the enzymatic antioxidant superoxide dismutase in all the cellular (granulosa cells, cumulus cells, and oocytes) and extracellular (follicular fluid) compartments of the follicle. Comparisons were made in bovine ovaries across progressive stages of antral follicular development. Follicular fluid possessed increased amounts of SOD1, SOD2, and SOD3 in small antral follicles when compared with large antral follicles; concomitantly, total SOD activity was highest in follicular fluids from smaller diameter follicles. SOD1, SOD2, and SOD3 proteins were expressed in granulosa cells without any fluctuations in follicle sizes. All three SOD isoforms were present, but were distributed differently in oocytes from small, medium, or large antral follicles. Cumulus cells expressed high levels of SOD3, some SOD2, but no detectable SOD1. Our studies provide a temporal and spatial expression profile of the three SOD isoforms in the different compartments of the developing bovine antral follicles. These results lay the ground for future investigations into the potential regulation and roles of antioxidants during folliculogenesis and oogenesis.

130 Increased antral follicle population at 60 days of gestation in Holstein cows with low antral follicle count

2020 ◽  
Vol 32 (2) ◽  
pp. 192
Author(s):  
R. G. Droher ◽  
F. Morotti ◽  
A. Guidugli Lindquist ◽  
A. Fonseca Zangirolamo ◽  
M. Marcondes Seneda
Keyword(s):  
Mixed Model ◽  
Linear Mixed Model ◽  
Antral Follicle ◽  
Generalized Linear Mixed Model ◽  
Antral Follicle Count ◽  
Antral Follicles ◽  
Intermediate Group ◽  
The Mean ◽  
Main Factors ◽  
High Repeatability

The antral follicle count (AFC) has been pointed out as one of the main factors that influence the efficiency of reproductive biotechniques. Thus, AFC is considered a fertility marker, which has high repeatability in the same animal. The objective of this study was to evaluate AFC in cows at AI (nonpregnant) and at two moments of gestation (30 and 60 days). For this, 35 pregnant cows, aged 23 to 99 months, confined in a freestall system, kept in the same environmental conditions (24°46'28”S, 49°56'42”W) and under the same feeding conditions, were selected for this study. The same technician performed the AI of the females, after detection of natural or induced oestrus, with 25mg of Dinoprost (Lutalyse) intramuscularly (IM). We established AFC (antral follicles ≥3mm diameter) using a convex intravaginal transducer at the time of AI and at 30 and 60 days of pregnancy. Females were distributed in groups of low (≤18 follicles, n=11), intermediate (≥24 and ≤28 follicles, n=11), or high AFC (≥30 follicles, n=13). Data were analysed using a generalized linear mixed model (Minitab version 18.1), with significance declared at P ≤ 0.05. In the low AFC group, there was an increase in the mean number of antral follicles in relation to gestation, presenting 14.82±1.36 at the time of AI and 23.45±2.31 and 35.18±3.17 at 30 and 60 days of pregnancy, respectively (P<0.0001). Similarly, the intermediate group presented an increase in mean AFC, from 24.64±0.76 at the time of AI and 29.27±3.32 at 30 days to 43.36±5.91 at 60 days of gestation (P=0.001). There was no difference in the high AFC group at different moments, as these presented 41.92±3.50 at the time of AI, 38.31±3.96 at 30 days, and 50.92±5.49 at 60 days of pregnancy. Although mean AFCs differed (P<0.0001) between the low, intermediate, and high AFC groups at time of AI and at 30 days of gestation, there were no differences in AFC between the three groups at 60 days of gestation (P=0.329). In conclusion, low AFC females presented an increase in the number of antral follicles at gestation moments 30 and 60 days from AI. This finding reinforces the strategy of using this category more efficiently for ovum pickup at the beginning of gestation.

Dissolved Oxygen Convection and Diffusion Numerical Simulation of Water and Air Mixture Flow in Circular Pipe

2011 ◽  
Vol 383-390 ◽  
pp. 6651-6656
Author(s):  
Ze Gao Yin ◽  
Xian Wei Cao ◽  
Dong Sheng Cheng ◽  
Le Wang
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Pipe Flow ◽  
Concentration Distribution ◽  
Dissolved Oxygen Concentration ◽  
Mixture Flow ◽  
Velocity Pressure ◽  
And Diffusion

In Fluent, the 3-D RNG k–ε mathematical model is employed to compute water and air mixture pipe flow. The dissolved oxygen convectionaεnd diffusion model is established to simulate the concentration distribution of dissolved oxygen with user defined scalar method. Velocity, pressure and dissolved oxygen concentration are computed. Then, dissolved oxygen concentration and pressure are compared with the data of physical model, and they agree with each other approximately, showing it is valid and reliable to compute the mixture pipe flow and dissolved oxygen concentration with the model .Furthermore, under a specific condition, velocity, pressure and dissolved oxygen concentration of water and air mixture pipe flow are computed and their characteristics are analyzed.

Epidermal growth factor in small antral ovarian follicles of pregnant women

1990 ◽  
Vol 127 (2) ◽  
pp. 363-367 ◽  
Author(s):  
L. G. Westergaard ◽  
C. Yding Andersen ◽  
A. G. Byskov
Keyword(s):  
Cell Proliferation ◽  
Growth Factor ◽  
Caesarean Section ◽  
Epidermal Growth Factor ◽  
Follicular Fluid ◽  
Follicle Growth ◽  
Antral Follicles ◽  
Follicular Size ◽  
Epidermal Growth ◽  
The Mean

ABSTRACT Levels of epidermal growth factor (EGF) and steroids were measured by radioimmunoassay in follicular fluid (FF) aspirated from 114 small antral follicles with diameters from 1 to 6 mm and in serum from 19 women undergoing Caesarean section at term. Concentrations of EGF in FF were inversely and significantly correlated to follicular size, being 4·7±0·4 (mean ± s.e.m.) nmol/l in follicles of 1–2 mm in diameter and declining to 2·2±0·2 and 1 ·4±0·2 nmol/l in follicles of 3–4 mm and 5–6 mm in diameter respectively. The mean ± s.e.m. concentration of EGF in serum (0·7±0·03 nmol/l) was significantly lower than that in FF. Levels of EGF, progesterone and oestradiol in FF were not significantly correlated to one another. In contrast to EGF, levels of progesterone and oestradiol in FF did not vary significantly with follicular diameter in these small follicles. On the basis of these results we suggest that EGF is synthesized in small human antral follicles, and that EGF stimulates granulosa cell proliferation and follicle growth up to 6 mm in diameter. Furthermore, the high intrafollicular levels of EGF may protect the small follicles against untimely effects of high levels of FSH, for instance during the mid-cycle surge of gonadotrophins. It is concluded that EGF plays an important role as an autocrine and/or paracrine regulator of development of small antral follicles in women. Journal of Endocrinology (1990) 127, 363–367

250 ANTI-MÜLLERIAN HORMONE: IMPLICATIONS FOR FOLLICULAR RESERVE, FOLLICULAR FUNCTION, AND FERTILITY IN THE MARE

2016 ◽  
Vol 28 (2) ◽  
pp. 257 ◽  
Author(s):  
B. A. Ball ◽  
A. Claes ◽  
T. E. Curry ◽  
M. H. T. Troedsson ◽  
E. L. Squires ◽  
...  
Keyword(s):  
Follicular Fluid ◽  
Age Groups ◽  
Antral Follicle ◽  
Antral Follicle Count ◽  
Middle Aged ◽  
University Of Kentucky ◽  
Antral Follicles ◽  
Follicular Reserve ◽  
The University ◽  
The Relationship

Anti-Müllerian hormone (AMH) is a granulosa-cell derived glycoprotein which plays an important regulatory role during folliculogenesis. Antral follicle count (AFC) and AMH have been used in several species to assess ovarian reserve, but relatively little is known about these parameters in mares. The objectives of this study were to determine (i) plasma AMH concentrations and AFC in mares of different ages, as well as their repeatability within and across oestrous cycles; (ii) the relationship between plasma AMH concentrations and AFC with regard to age and follicle size; and (iii) endocrine and molecular changes in growing and preovulatory follicles in relation to AFC and peripheral AMH concentrations. In Exp. 1, young (3–8 years), middle-aged (9–18 years), and old (>18 years) mares were examined by transrectal ultrasonography over 2 to 3 oestrous cycles and changes in the number and size of all detectable antral follicles were recorded. Concentrations of AMH were determined by ELISA. In Exp. 2, molecular and endocrine differences in growing and dominant equine follicles were examined in relationship to variation in AFC, peripheral AMH concentrations and mare age. Follicular fluid oestradiol and AMH concentrations were determined by immunoassay, and expression of AMH, AMHR2, ESR1, ESR2, FSHR, IGF1, INHA, INHBA, and CYP19A1 was determined by quantitative RT-PCR. Antral follicle counts were significantly lower in old mares than in young and middle-aged mares, and AMH concentrations were significantly lower in old mares than in middle-aged mares. A positive relationship was detected between AFC and AMH, and this relationship varied by mare age with a strong correlation in older mares (ρ = 0.86; P < 0.0001), a moderate correlation in middle-aged mares (ρ = 0.60; P = 0.01), and no correlation (ρ = 0.40, P < 0.4) in young mares. Circulating AMH concentrations were significantly related to the number of antral follicles between 6 and 20 mm in diameter, and the repeatability of AFC and AMH concentrations was high within and between oestrous cycles. Within growing follicles, expression of AMH, AMHR2, ESR2, and INHA in granulosa cells was significantly associated with AFC and plasma AMH concentrations, whereas expression of ESR1 and FSHR were significantly correlated with AMH concentrations alone. In follicular fluid, AMH concentrations declined and oestradiol concentrations increased in dominant compared to growing follicles. Our findings indicate that the relationship between AMH and AFC varies across age groups, and that variations in AFC and plasma AMH concentrations are associated with molecular differences in the equine follicle, which, in turn, may have an impact on follicular function. Funded by the Albert G. Clay Endowment at the University of Kentucky.

scholarly journals Antral follicles population in heifers and cows of Nelore and Girolando breeds

2015 ◽  
Vol 36 (6) ◽  
pp. 3741
Author(s):  
Jair Sábio de Oliveira Junior ◽  
Christopher Junior Tavares Cardoso ◽  
Wilian Aparecido Leite da Silva ◽  
Henrique Kischel ◽  
Mirela Brochado Souza ◽  
...  
Keyword(s):  
Age Groups ◽  
Antral Follicle ◽  
Estradiol Benzoate ◽  
Antral Follicles ◽  
Follicular Wave ◽  
The Mean ◽  
The Right ◽  
Intravaginal Device ◽  
Nelore Cattle ◽  
Single Ovary

The aim of this study was to evaluate ovarian antral follicle populations (OAFP) of Nelore and Girolando breed heifers (12–18 months old) and cows (24–60 months old). Animals were assigned to four groups: (1) Nelore cows (n = 18), (2) Girolando cows (n = 20), (3) Nelore heifers (n = 7), and (4) Girolando heifers (n = 7). Cows were treated to synchronize follicular wave emergence by implantation of an intravaginal device containing 1.9 g of progesterone, as well as intramuscular administration of 2 mg of estradiol benzoate and 25 mg of dinoprost. This synchronization treatment was administered at a random day of the estrous cycle of each cow, designated D0. Intravaginal devices were removed on D7, and on D11, OAFP counts were performed by transvaginal ovarian ultrasound. For each cow, all follicles ?3 mm in diameter were counted in both ovaries and counts were performed three times at 35-day intervals. Counts were also obtained from heifers, but these animals were not treated for synchronization of follicular wave emergence. Analysis of variance (ANOVA) with Tukey’s test and Pearson’s correlation test were used to compare mean OAFPs between counts as well as mean OAFPs between breed and age groups. No differences were observed in mean OAFPs between Nelore and Girolando cows (30.9 vs. 26.7, respectively; P > 0.05) or heifers (16.2 vs. 18.1, respectively; P > 0.05). However, within each breed, there were differences in mean OAFPs between heifers and cows (for Nelore cattle: 16.2 and 30.9, respectively; for Girolando cattle: 18.1 and 26.7, respectively; both P < 0.05). In conclusion, OAFPs were similar between Nelore and Girolando breeds and were influenced by age. Furthermore, we observed a high correlation for individual animals between the mean numbers of follicles counted in both ovaries and total number of follicles counted in either the right or left ovary, indicating that the evaluation of a single ovary is sufficient to estimate the OAFP of an individual.

scholarly journals Deslorelin Slow-Release Implants Delay Ovulation and Increase Plasma AMH Concentration and Small Antral Follicles in Haflinger Mares

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1600
Author(s):  
Martim Kaps ◽  
Carolina T. C. Okada ◽  
Camille M. Gautier ◽  
Jörg Aurich ◽  
Christine Aurich
Keyword(s):  
Slow Release ◽  
Antral Follicle ◽  
Domestic Animals ◽  
Antral Follicle Count ◽  
Estrous Cycles ◽  
Antral Follicles ◽  
Promising Tool ◽  
Reproductive Techniques ◽  
Treatment Interaction ◽  
The Mean

There is an increasing interest in the manipulation of ovarian follicular populations in large domestic animals because this could prove beneficial for assisted reproductive techniques such as ovum pick-up (OPU). The aim of the present study was to evaluate the effects of deslorelin slow-release implants (SRI) on the interovulatory interval, antral follicle count (AFC), number of follicles of different size ranges and plasma anti-Muellerian hormone (AMH) concentration in mares. To synchronize their estrous cycles, Haflinger mares (n = 12) were treated twice with a PGF2α analogue. One day after the second injection (day 0), mares received a 9.4 mg deslorelin SRI (group DES, n = 6) or 1.25 mg deslorelin in a short-acting formulation (CON; n = 6), respectively. Regular transrectal ultrasonography of the genital tract was performed and blood samples were collected for the analysis of progesterone, AMH and gonadotrophins. The interval from implant insertion to the first spontaneous ovulation was 23.8 ± 10.5 days in group DES compared to 17.0 ± 3.9 days in group CON (p < 0.05). For the concentrations of LH, FSH and AMH, interactions between time and treatment were detected (p < 0.05). The AFC and the mean number of follicles with 5 to 10, 10 to 15 and 15 to 20 mm in diameter changed over time (p < 0.05). A time x treatment interaction was demonstrated for follicles of 10 to 15 mm in diameter (p < 0.05). The changes in this follicular subpopulation were reflected by increased plasma AMH concentration in group DES. In conclusion, 9.4 mg deslorelin implants show minor effects with regard to estrus suppression in mares, whereas the changes in the subpopulation of small ovarian follicles could be a promising tool for preparation of mares for OPU.

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