Ultrasound biomicroscopy: a non-invasive approach for in vivo evaluation of oocytes and small antral follicles in mammals

2014 ◽  
Vol 26 (1) ◽  
pp. 48 ◽  
Author(s):  
L. F. M. Pfeifer ◽  
G. P. Adams ◽  
R. A. Pierson ◽  
J. Singh
Keyword(s):  
Ovarian Function ◽  
Ultrasound Biomicroscopy ◽  
Biomedical Sciences ◽  
Depth Of Penetration ◽  
In Vivo Evaluation ◽  
Invasive Approach ◽  
Antral Follicles ◽  
Advantages And Disadvantages ◽  
And Control

The use of ultrasonography has changed our understanding of the ovarian function in live animals. However, most of the studies that have used ultrasonography to image the ovary have provided data only of structures >1 mm in diameter. The recent availability of high-resolution ultrasound technology with high-frequency transducers (25–70 MHz), offers the potential to examine the developmental dynamics of small antral follicles and the cumulus–oocyte complex (COC) in vivo. In this review we provide data from a series of studies performed by Veterinary Biomedical Sciences Laboratory describing the advantages and disadvantages, as well as image characteristics, of ultrasound biomicroscopy (UBM) to study ovarian biology in mammals. Data and images of small ovarian structures in rabbits, cattle, mice and humans are shown. The UBM technique allowed visualisation of small antral follicles ranging in size from 300 to 700 μm in all species examined, as well as COC within follicles in rabbits, cattle and humans. Furthermore, UBM permitted clear distinction of the follicular wall from the surrounding ovarian stroma in cattle and humans. At present, the limited depth of penetration of UBM restricts the use of this technique to an experimental setting. In that regard, further studies using UBM will probably result in a greater understanding of the pattern and control of early antral folliculogenesis and oogenesis.

220 ULTRASOUND BIOMICROSCOPY: A NONINVASIVE APPROACH FOR STUDYING THE DEVELOPMENT OF SMALL FOLLICLES IN THE BOVINE OVARY

2010 ◽  
Vol 22 (1) ◽  
pp. 268
Author(s):  
L. M. Pfeifer ◽  
G. P. Adams ◽  
R. A. Pierson ◽  
L. G. Siqueira ◽  
J. Singh
Keyword(s):  
Follicular Development ◽  
Ultrasound Biomicroscopy ◽  
Growth Patterns ◽  
Signal Attenuation ◽  
Depth Of Penetration ◽  
Transvaginal Approach ◽  
Antral Follicles ◽  
Canada Data

Ultrasonography has revolutionized our understanding of the dynamics of antral follicles >3 mm; however, very little is known about the growth patterns of small antral follicles (0.2-2 mm). Ultrasound biomicroscopy (UBM) permits in vivo imaging of tissues with spatial resolution of 50 μm or more, although the depth of penetration is limited to about 2.5 cm. Our objectives were to (1) evaluate the feasibility of UBM for imaging cow v. heifer ovaries in vivo for study of small antral follicles; (2) compare transvaginal v. transrectal imaging approaches; and (3) compare the echotextures in images acquired by UBM and conventional ultrasonography of the wall and antrum (follicular fluid) from follicles >3 mm. Mature cows (n = 5) and prepubertal heifers (11-13 months; n = 5) were examined once irrespective of ovarian status using conventional ultrasonography (Aloka 900, Tokyo, Japan) with a 7.5-MHz transducer via a transrectal approach, and with a 5-MHz transducer via a transvaginal approach. A second series of examinations was performed using an ultrasound biomicroscope (Visualsonics Vevo 660, Toronto, Ontario, Canada) equipped with either a 40-MHz probe (transvaginal) or a 30-MHz probe (transrectal). All examinations were recorded digitally in real time. Spot-analyses of images of the antrum and line-analyses of images of the wall of follicles >3 mm were performed using a custom-developed software program (Synergyne 2 version 2.8, Saskatoon, Saskatchewan, Canada). Data were analyzed by 2-sample t-test or two-way ANOVA. Using the transvaginal approach, more follicles were detected by UBM than by conventional ultrasonography in heifers (40.4 ± 17.4 v. 14.6 ± 5.6; P = 0.01) but not in cows (38.3 ± 16.4 v. 21.7 ± 6.2; P = 0.20). Using the transrectal approach, however, more follicles were detected by conventional ultrasonography than by UBM in both heifers (17.6 ± 4.9 v. 8.6 ± 5.6; P = 0.02) and cows (20.3 ± 7 v. 5.3 ± 6.1; P = 0.04). More small follicles (<3 mm) were detected using the transvaginal approach with UBM than by using conventional ultrasonography in both heifers (32.4 ± 4.24 v. 7.2 ± 1.4; P < 0.0001) and cows (35.0 ± 13.8 v. 10.7 ± 7.5; P = 0.0013). The number of medium (3-5 mm) and large (> 5 mm) follicles detected using the transvaginal approach was similar between UBM and conventional ultrasonography in both heifers and cows (P > 0.90). For transrectal UBM imaging, both distance between the scanhead and the ovary and signal attenuation due to intervening tissues resulted in poor image quality. Lower signal attenuation caused by thinner vaginal walls in heifers than in cows resulted in better quality of UBM imaging in the transvaginal approach. Mean pixel values and heterogeneity of images of the follicle antrum were higher in UBM images than in conventional ultrasonography images. In conclusion, UBM using a transvaginal approach may be used for the in vivo assessment of small ovarian follicles in cattle. However, sequential monitoring of follicular development still needs to be tested and some limitations of the technique, such as the approach, need to be considered. This study was supported by NSERC and CIHR, Canada. Luiz Pfeifer was supported by CAPES foundation, Brazil.

In-vivo evaluation of lipid lowering ability of Chloris paraguaiensis extracts

2020 ◽  
Vol 7 (2) ◽  
pp. 21-24
Author(s):  
Pavani C H
Keyword(s):  
Medicinal Plants ◽  
Chemical Constituents ◽  
The Body ◽  
Lipid Lowering ◽  
Medical Systems ◽  
In Vivo Evaluation ◽  
Standard Drug ◽  
Anti Oxidant ◽  
And Control

Hyperlipidemia is the immediate results of the excessive fat intake in food. This results in the elevated levels of cholesterol and triglycerides in the blood. This leads to heart conditions like CAD, hypertension, congestive heart failure as risk factors which can be lethal. There are many drugs to treat and control the lipids levels in the body. These drugs are either designed to prevent LDL accumulation and VLDL synthesis. Some drugs also lower the elevated levels of saturated lipids in the body. But many drugs are known to cause side effects and adverse effects; therefore, alternatives to the drugs are the subjects for current investigations. Herbs and medicinal plants are used as treatment sources for many years. They have been used in the Indian medical systems like Ayurveda, Siddha etc. As the application of herbs in the treatment is growing, there is an urgent need for the establishment of Pharmacological reasoning and standardization of the activity of the medicinal plants. Chloris paraguaiensis Steud. is Poyaceae member that is called locally as Uppugaddi. Traditionally it is used to treat Rheumatism, Diabetes, fever and diarrhoea. The chemical constituents are known to have anti-oxidant properties and most of the anti-oxidants have anti-hyperlipidemic activity too. Since the plant has abundant flavonoid and phenol content, the current research focusses on the investigation of the anti-hyperlipidemic activity of the plant Chloris extracts. Extracts of Chloris at 200mg/kg showed a comparably similar anti hyperlipidemia activity to that of the standard drug. The extracts showed a dose based increase in the activity at 100 and 200mg/kg body weight.

132 A NEW APPROACH TO ASSESS OVARIAN STRUCTURES IN LIVE RABBITS: SURGICAL TRANSLOCATION AND ULTRASOUND BIOMICROSCOPY

2012 ◽  
Vol 24 (1) ◽  
pp. 178
Author(s):  
M. P. Cervantes ◽  
J. M. Palomino ◽  
B. Toosi ◽  
K. Linn ◽  
G. P. Adams
Keyword(s):  
Ovulation Induction ◽  
Ovarian Function ◽  
Subcutaneous Fat ◽  
Ultrasound Biomicroscopy ◽  
The Body ◽  
Skin Thickness ◽  
Sound Waves ◽  
New Approach ◽  
Factors Associated

For the purpose of determining factors associated with ovulation induction in rabbits, there is a need to examine the ovaries in a serial fashion. To this end, a study was designed to develop an approach that would permit serial evaluation of ovarian structures in vivo using ultrasound biomicroscopy (UBM) while preserving ovarian function in rabbits. The use of UBM has enabled characterisation of ovarian dynamics in live mice and has recently been validated for assessing structures in excised rabbit ovaries (Cervantes et al. 2011 Reprod. Fertil. Dev. 23, 183–184). However, acoustic impedance of the body wall prevented acquisition of high-quality ovarian images in vivo by transabdominal UBM in rabbits. Female New Zealand White rabbits (5 months old; n = 12) underwent surgical ovarian translocation. Each ovary was exteriorized through a lateral flank incision on the respective sides, without compromising vascular supply. The mesovarium at each pole of the ovary was transfixed to the muscle layers of the abdominal wall to keep the ovary in a subcutaneous position. Finally, the subcutaneous and skin layers were closed. No postoperative complications were observed. The surgical site was allowed to heal for 2 weeks and the skin sutures were removed before UBM was attempted. The rabbits were wrapped in a towel for restraint without sedation. Acoustic gel was applied to the shaved skin over the translocated ovary and ovarian structures were imaged transcutaneously by UBM using a 25-MHz transducer on 3 consecutive days. Both ovaries were clearly distinguished in all 12 rabbits during each examination. Antral follicles ranging from 0.6 to 3.1 mm were detected and the number of follicles ≥0.6 mm per pair of ovaries ranged from 7 to 18. Data were analysed by one-way ANOVA. The number and diameter of follicles ≥0.6 mm per rabbit did not differ among the 3 examinations (mean ± s.e.m.; 11.0 ± 0.82, 11.8 ± 0.85 and 12.3 ± 0.75 follicles and 1.3 ± 0.07, 1.3 ± 0.07 and 1.4 ± 0.07 mm, respectively). However, follicles ≥2 mm in diameter were detected in 3 out of 12 rabbits on the first and second days and in 5 out of 12 rabbits on the third day. One or more corpora lutea were detected in the same 2 rabbits (2/12) during each of the 3 examination days. Two months after surgery, ovarian structures were clearly discernible by UBM in 11 of 24 translocated ovaries. Image deterioration was attributed to the attenuation of sound waves associated with increased skin thickness and growth of subcutaneous fat and connective tissue around the ovary, assessed at necropsy. In summary, translocated ovaries continued to function in their new location and transcutaneous UBM permitted serial visualisation of ovarian structures in live rabbits. Therefore, this new approach provides a nonterminal alternative for repetitive examination of rabbit ovaries and is particularly appropriate for experiments involving factors associated with ovulation induction in rabbits. This research was supported by the Natural Sciences and Engineering Research Council of Canada.

In Vivo Evaluation of Nano-HA/PDLLA Composite

2005 ◽  
Vol 284-286 ◽  
pp. 881-884 ◽  
Author(s):  
Yu Mei Xiao ◽  
Hong Song Fan ◽  
Yao Wu ◽  
Jin Rui Xu ◽  
Y. Tan ◽  
...  
Keyword(s):  
Histological Analysis ◽  
Sem Analysis ◽  
Albino Rats ◽  
Degradation Behavior ◽  
Porous Network ◽  
In Vivo Evaluation ◽  
Good Biocompatibility ◽  
Wistar Albino Rats ◽  
And Control

The purpose of this study was to evaluate the behavior of nano-hydroxyapatite/ poly(D,L)lactide (n-HA/PDLLA) composite in vivo. The composite rods containing about 40wt% n-HA and control HA rods with a diameter of 2mm and a length of 6mm were implanted into the femora of 16 New Zealand rabbits. Composite wafers with a diameter of 5mm and a thickness of 1mm were implanted into the dorsal subcutis of 18 Wistar Albino rats. After definite intervals, the histological analysis was completed by light microscopy and the degradation behavior was observed by scanning electron microscopy. The histological analysis showed no obvious difference between n-HA /PDLLA composite and pure HA that had good biocompatibility and osteoconductivity. SEM analysis of the surface and cross section of the samples showed that the degradation of the composite started from surface, then into the inner gradually and formed multiple pores at surface. The pore size and porosity gradually increased along with time and a porous network may be formed.

435. Follicle differentiation and luteinisation in the mouse is associated with hypoxia inducible factor activity

2008 ◽  
Vol 20 (9) ◽  
pp. 115
Author(s):  
K. Tam ◽  
D. Russell ◽  
K. Kind ◽  
J. Thompson
Keyword(s):  
Granulosa Cells ◽  
Target Genes ◽  
Ovarian Function ◽  
Egfp Expression ◽  
Corpora Lutea ◽  
Limited Information ◽  
Antral Follicles ◽  
Follicle Differentiation

Hypoxia inducible factors (HIF) are transcription factors that mediate the response to hypoxic stress. Under hypoxic conditions, HIF is stabilised, translocates to the nucleus, and binds to the Hypoxia Response Elements (HRE) upstream of numerous target genes involved in angiogenesis and glycolysis, including Vegf, Glut-1 and Ldha. Little is known about the role of HIFs in regulating ovarian function. In rat granulosa cells, FSH stimulates HIF 1α via the PI3K/Akt pathway, demonstrating a role for HIFs during follicular development. In contrast, there is limited information regarding the role of HIFs during corpus luteum formation. In this study we investigated whether HIFs play a role in follicle differentiation and luteinisation. Prepubertal C57Bl6 females were stimulated with eCG (5 IU) followed 46 h later by hCG (5 IU). Mice were sacrificed at 0, 4, 8, 12, 16 and 24 h post hCG and granulosa cells were collected for Western analysis of HIF-1a protein. To investigate HIF activation in the ovary, a transgenic reporter mouse line was developed by lenti-viral incorporation of an HRE (4)-SV40-eGFP construct. Ovaries were collected from mice plugged day 1, 4 and 8 for CL analysis in vivo.A time- dependent increase of HIF 1α protein levels in granulosa cells, maximal around time of ovulation, was observed. Ovaries from cycling HRE-eGFP transgenic mice exhibited no eGFP in primordial, primary or preantral follicles. Upon antrum formation, eGFP was evident in occasional sections in antral follicles but HIF signalling was restricted within the theca. In contrast, corpora lutea on pregnancy day 1, 4 and 8 readily expressed eGFP and eGFP expression increases as luteinisation progresses.These results demonstrate that in vivo HIFs may play a role in folliculogenesis, but this is restricted to theca cells of antral follicles before hCG stimulation. Following hCG, maximal HIF activity is associated with the time of ovulation. In addition, HIF activity is maintained during luteinisation.

scholarly journals Tubular electrospun scaffolds tested in vivo for tissue engineering

2019 ◽  
Vol 7 (2) ◽  
pp. 635
Author(s):  
Alan Isaac Valderrama-Treviño ◽  
Karen Uriarte-Ruiz ◽  
Juan José Granados Romero ◽  
Andrés Eliú Castell Rodriguez ◽  
Alfredo Maciel-Cerda ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Small Diameter ◽  
Cellular Adhesion ◽  
In Vivo Evaluation ◽  
Structural Support ◽  
Electrospun Scaffolds ◽  
Advantages And Disadvantages ◽  
The Creation

Tissue engineering has been widely used for its great variety of functions. It has been seen as a solution to satisfy the need for vascular substitutes like small diameter vessels, veins, and nerves. One of the most used methods is electrospinning, due to the fact that it allows the use of various polymers, sizes, mandrels and it can adjust the conditions to create personalized scaffolds. For the creation of scaffolds is fundamental to understand the advantages and disadvantages of each polymer, of this, will depend the biodegradability, biocompatibility, porosity, cellular adhesion, and cell proliferation as it is essential to mimic the extracellular matrix and provide structural support for the cells. The aim of this review was to investigate which materials are being used for the creation of tubular scaffolds by electrospinning. Here we selected only in vivo evaluation to demonstrate remodeling of the grafts into native-like tissues, in vitro evaluations had been excluded from this review. We analyze the conditions like speed, distance and voltage and the modifications like growth factors and combinations of natural and synthetic polymers that allow the authors to have a functional scaffold that will suit its purpose.

Epidermal growth factor acts directly on the sheep ovary in vivo to inhibit oestradiol-17β and inhibin secretion and enhance progesterone secretion

1993 ◽  
Vol 137 (2) ◽  
pp. 253-264 ◽  
Author(s):  
J. F. Murray ◽  
J. A. Downing ◽  
G. Evans ◽  
J. K. Findlay ◽  
R. J. Scaramuzzi
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Granulosa Cells ◽  
Ovarian Function ◽  
Jugular Vein ◽  
Follicular Phase ◽  
Antral Follicles ◽  
Progesterone Secretion ◽  
Epidermal Growth

ABSTRACT Epidermal growth factor (EGF) is a potential intra-ovarian modulator of gonadotroph action on differentiated follicular cells. Specific binding sites have been identified in the ovary and functional differentiation in cultured granulosa cells can be modulated by treatment with EGF. The aim of this study was to determine if EGF was capable of altering ovarian function in vivo during the follicular phase of the sheep oestrous cycle. Fourteen cross-bred ewes with ovarian autotransplants were treated with progestagen pessaries for 12 days. Three ewes were infused with murine EGF (mEGF) via the jugular vein (75 μg/kg bodyweight per 12 h) during the 12 h preceding progestagen pessary withdrawal, and received an injection of a prostaglandin analogue at 0 h to induce luteolysis. Over the same time-period, two doses of EGF were administered to other groups of ewes by infusion into the ovarian artery (low: 6 μg/12 h, n = 3 and high: 60 μg/12 h, n = 3). The remaining five ewes were not infused with EGF (controls). Jugular and ovarian venous blood samples were taken at 10-min intervals at two stages during the follicular phase (21–27 h and 38–42 h after pessary withdrawal) and every 2 h from 44 to 76 or 86 h. mEGF, LH, FSH, inhibin, androstenedione, oestradiol-17β and progesterone concentrations in plasma were determined using radioimmunoassays. The secretion rates of androstenedione, oestradiol, progesterone and inhibin by the ovary were calculated. EGF acted directly on the ovary in a dose-dependent manner. Oestradiol secretion was inhibited following treatment with EGF but androstenedione secretion was unaffected. EGF appears therefore to act within the granulosa cells to inhibit aromatization. Inhibin secretion was also suppressed by treatment with EGF, though it was not possible to determine if this was caused by a direct or indirect action of EGF on granulosa cells. The rate of progesterone secretion increased in ewes receiving systemic (i.e. via the jugular vein) and high-dose intra-arterial infusions of EGF, even though a preovulatory LH surge was not observed in these animals during the entire experimental period. Concomitant increases in both LH and FSH secretion were associated with these effects of EGF on ovarian function. In conclusion, EGF appears to act directly on the granulosa cells of the follicle to inhibit aromatization and also to inhibit inhibin production. The low levels of oestradiol and inhibin in the presence of high levels of gonadotrophin indicate that atresia may have been induced in medium to large antral follicles. The increase in progesterone secretion following high doses of EGF may be derived from a luteinized follicle. FSH-stimulated functions cease when a follicle luteinizes and progesterone secretion commences. EGF treatment inhibited both oestradiol and inhibin secretion whilst enhancing progesterone which suggests that EGF may also be involved in the induction of functional luteinization. EGF or an EGF-like substance may therefore be an important factor in the induction of functional luteinization, with atresia occurring in antral follicles which are exposed to EGF too early in their development. Journal of Endocrinology (1993) 137, 253–264

Sign in / Sign up

Export Citation Format

Share Document