Transrectal Doppler sonography of uterine blood flow

Transrectal Doppler ultrasound was used for the noninvasive investigation of uterine blood flow in cows. Both the left and right Aa. uterinae were scanned to obtain blood flow velocity waveforms over 2 consecutive estrous cycles. Blood flow was reflected by the resistance index (RI) and the time-averaged maximum velocity (TAMV). Intra-observer reproducibility of Doppler measurements was evaluated. The intra-class correlation coefficient (Intra-CC) was 0.97 for the RI and 0.95 for TAMV. While RI values did not differ between the left and right A. uterina (P > 0.05), differences in TAMV occurred between both vessels in 2 cows. These differences were not related to the ovary bearing the dominant follicle or to the corpus luteum (P < 0.001). As in all cows, changes of RI and TAMV values between the left and right artery during the estrous cycle were correlated (correlation coefficient r > 0.72; P < 0.0001); the mean values of both sides were used for subsequent analyses. Variance component estimates for the effect of cow on RI and TAMV were 8 and 13% and for the influence of day of estrous cycle they were 70 and 47%, respectively (P <0.0001). Between estrous cycles no significant differences could be measured within cows (P > 0.05). The highest RI and lowest TAMV values occurred on Day 0 (= day of ovulation) and Day 1, while the lowest RI and highest TAMV values were measured between Days -3 and -1 of the estrous cycle, respectively. There was a positive correlation between TAMV and estrogen concentrations and a negative correlation between RI and plasma estrogen levels. Plasma progesterone levels and TAMV were negatively correlated, but no correlation could be measured (P > 0.05) between RI values and plasma progesterone concentrations. While there were no differences in plasma concentrations of estrogens and progesterone between estrous cycles within cows, the levels of these hormones differed between cows. The results show that transrectal Doppler sonography is a useful, noninvasive method for examining uterine blood flows in cows. If there is an influence of uterine perfusion on fertility in cows its role needs further investigation.     

Uterine blood flow during the first 3 weeks of pregnancy in dairy cows

Transrectal color Doppler sonography was used to compare changes in uterine blood flow between cyclic and early pregnant lactating dairy cows. Examinations were carried out in 53 multiparous lactating cows on days 3, 6, 9, 11, 13, 15, 18 and 21 (day 0=estrus). Fourteen cows were examined during the estrous cycle and thirty-nine cows after insemination with frozen/thawed sperm. Uterine blood flow was reflected by the time-averaged maximum velocity (TAMV) and the pulsatility index (PI) in the uterine artery ipsilateral to the corpus luteum. Twenty-one cows that were not pregnant on day 25 were excluded from the study. There was high inter-individual variability in PI- (CV: 22-62%) and TAMV-values (CV: 22-42%) at all examinations. In cyclic cows, TAMV values increased between days 13 and 18 and PI values decreased between days 15 and 21 (P<0.05). In pregnant cows (n=18), TAMV values increased from days 9 to 11 and then decreased to minimal values by day 18 (P<0.05). The PI values decreased between days 3 and 11 and then increased to maximum levels on day 18 (P<0.05). On day 21, both variables reached (P<0.05) values that did not differ (P>0.05) from those on day 11. The changes in TAMV were correlated with estrogen and progesterone concentrations (r=0.69 and -0.70, respectively; P<0.05) in cycling cows, but not in pregnant cows (P>0.05). The PI values did not correlate with steroid hormone levels (P>0.05). Differences in uterine blood flow between cycling and early pregnant cows were observed only on day 18 (P<0.05). The results show that in pregnant cows changes in uterine blood supply can be detected already in the second week after insemination; these changes do not occur in the second week of the cycle.     

A preliminary retrospective study about the relationship between ductus venosus Doppler indices, nuchal translucency (NT) and biochemical markers in the first and second trimester screening tests

In our study, we tried to assess the relation between ductus venosus Doppler indices [pulsatility index (PI), resistance index (RI) and S/D] and first-trimester screening markers (MoM of serum pregnancy-associated plasma protein A, pappalysin 1 (PAPP-A), MoM of serum free β-human chorionic gonadotrophin (β-hCG), and nuchal translucency (NT) and second trimester screening markers (MoM of serum α-fetoprotein, MoM of serum total β-hCG and MoM of serum estriol). We analyzed the data of 121 singleton pregnancies. Roche cobas e 601ECLIA (electrochemiluminescence immunoassay) was used to measure MoM of serum PAPP-A and Roche cobas e 602 ECLIA (electrochemiluminescence immunoassay) was used to measure MoM of serum free β-hCG in the first trimester. Beckman Coulter Access 2 Immunoassay was used to measure MoM of serum α-fetoprotein, MoM of serum total β-hCG and MoM of serum estriol in the second trimester. The first author performed all ultrasound screenings and ductus venosus Doppler studies. What we found new in our study is presented as following; MoM of serum α-fetoprotein had a negative correlation with RI of ductus venosus Doppler, MoM of serum estriol had a negative correlation with RI of ductus venosus Doppler and MoM of serum estriol had a negative correlation with S/D of ductus venosus doppler. The results of our study suggest that ductus venosus Doppler can be used to increase the effectiveness of the second trimester screening test.     

Transrectal Doppler sonography of uterine blood flow during early pregnancy in mares

Transrectal color Doppler sonography was used for the noninvasive investigation of uterine blood flow in five mares. Both the left and right uterine arteries were scanned to obtain blood flow velocity waveforms during two consecutive estrous cycles and two early pregnancies in each mare. Blood flow was expressed as the time-averaged maximum velocity (TAMV) and the resistance index (RI). In all pregnancies the embryonic vesicle could be detected for the first time on Day 11 (day of ovulation: Day 0). No differences in mean TAMV and RI values of both uterine arteries were observed in comparison to the corresponding days of the estrous cycle until Day 11 of pregnancy (P>0.05). From Day 11 onwards, mean TAMV values were higher and mean RI values lower in pregnant mares than in cyclic mares (P<0.05). During the estrous cycle TAMV and RI values did not differ between the right and left uterine arteries (P>0.05). From Days 15 to 29 of pregnancy, TAMV values were consistently higher and RI values lower in the uterine artery ipsilateral to the conceptus and they had a more distinct rise and decline, respectively, compared to the contralateral uterine artery (P<0.05). The variance component estimates for the effect of mare on TAMV and RI values during pregnancy were 60 and 53%, respectively, and for the effect of day of pregnancy, they were 29 and 34%, respectively (P<0.0001). Within mares there were no significant differences between the two pregnancies with regard to blood flow (P>0.05). The results show that uterine blood supply increases in mares during the second week of pregnancy compared to cyclic mares. Furthermore there are individual variations in blood flow between mares.     

Uterine and ovarian blood flow during the estrous cycle in mares

Uterine and ovarian blood flow was investigated in four mares during two consecutive estrous cycles using transrectal color Doppler sonography. The uterine and ovarian arteries of both sides were scanned to obtain waves of blood flow velocity. The pulsatility index (PI) reflected blood flow. There were significant time trends in PI values of all uterine and ovarian blood vessels during the estrous cycle (P < 0.05). PI values did not differ between the uterine arteries ipsi- and contralateral to the corpus luteum or the ovulatory follicle. PI values of the uterine arteries showed a wave shaped profile throughout the estrous cycle. The highest PI values occurred on Days 0 and 1 (Day 0 = ovulation) and around Day 11, and the lowest PI values were measured around Days 5 and -2 of the estrous cycle. During diestrus (Days 0-15) PI values of the ovarian artery ipsilateral to the corpus luteum were significantly lower than PI values of the contralateral ovarian artery (P < 0.0001). No differences (P > 0.05) in resistance to ovarian blood flow occurred between sides during estrus (Days -6 to -1). In this cycle stage PI values decreased in both ovarian vessels (P < 0.05). During diestrus, high PI values of the ovarian artery ipsilateral to the corpus luteum were measured between Days 0 and 2, followed by a decline until Day 6 (P < 0.05). From this time on, the resistance to blood flow increased continuously until Day 15 (P < 0.05). The cyclic blood flow pattern in the contralateral ovarian artery was similar to that in the uterine arteries (r = 0.68; P < 0.0001). No correlations occurred between the diameter of the corpus luteum and the PI values of the ipsilateral ovarian artery (P > 0.05) during diestrus. During estrus, there was a negative relationship between growth of the diameter of the ovulatory follicle and changes in PI values of the dominant ovarian artery (r = -0.41; P < 0.05). PI values of the uterine arteries and of the ovarian artery ipsilateral to the ovulatory follicle were negatively related to estrogen (E) levels in plasma during estrus (uterine arteries: r = -0.21; P < 0.05; dominant ovarian artery: r = -0.35; P < 0.05). In diestrus, PI values of the dominant ovarian artery were negatively related to plasma progesterone levels (r = -0.38; P < 0.0001), but not the PI values of the uterine arteries (P > 0.05). The findings of this study show that there are characteristic changes in blood supply of the uterus and the ovaries throughout the equine estrous cycle. There are negative correlations between resistance to blood flow in the uterine and ovarian arteries and the plasma estrogen levels during estrus. In diestrus, there is a negative relationship between the resistance to ovarian blood flow and the progesterone levels.     

Doppler sonography of the uterine arteries during a superovulatory regime in cattle. Uterine blood flow in superovulated cattle

Transrectal color Doppler sonography was used to investigate the effects of a gonadotropin treatment to induce superovulation on uterine blood flow and its relationship with steroid hormone levels, ovarian response and embryo yield in dairy cows. The estrous cycle of 42 cows was synchronized by using PGF(2alpha) during diestrus and GnRH 48 h later (Day 0). Cows were examined on the day of eCG (2750 IU)-administration (Day 10), 3 days after eCG (Day 13) and 7 days after artificial insemination (Day 22), including the determination of total estrogens (E) and progesterone (P(4)) in peripheral plasma. Eight days after insemination (Day 23) the uterus was flushed and the number of total ova and embryos as well as transferable embryos was determined. The ovarian response was defined by the number of follicles>5.0mm in diameter on Day 13 and the number of corpora lutea on Day 22. Uterine blood flow was reflected by the blood flow volume (BFV) and the pulsatility index (PI) in the uterine arteries. Both variables showed distinct changes throughout the superovulatory cycle: BFV increased by 94% and PI decreased by 30% between Days 10 and 22 (P<0.0001). On Day 13, BFV but not PI correlated with follicle numbers (r=0.35; P<0.05); no correlation was found with E and P(4) (P>0.05). On Day 22, BFV correlated positively and PI correlated negatively with the number of corpora lutea (r=0.45 and r=-0.37; P<0.05) and P(4) (r=0.39 and r=-0.30; P<0.05). The number of transferable embryos was solely related to BFV measured on Day 13 (r=0.32; P<0.05). Our results show for the first time that in cows a superovulatory treatment is associated with a marked increase in BFV and a marked decrease in PI in the uterine arteries, concurrent with the development of multiple follicles and corpora lutea. However, transrectal color Doppler sonography of the uterine arteries does not facilitate the prediction of embryo yields following superovulatory treatment.     

Transrectal Doppler sonography for evaluation of uterine blood flow throughout pregnancy in 13 cows

Once weekly from 30 to 270 days of gestation in 13 cows, Doppler ultrasound scanning (triplex Doppler system) was done to assess blood-flow parameters of both median uterine arteries. Resistance, velocity and volume indices were measured. Resistance index values were negatively correlated to all other blood-flow parameters (P<0.05), but there were positive correlations between velocity and volume indices (P<0.05). Resistance indices were lower, and velocity and volume indices were significantly higher in the median uterine artery ipsilateral versus contralateral to the fetus. Resistance indices decreased continuously during the first 36 weeks of pregnancy. Velocity values rose three-fold, whereas the area increased 20-fold and the volume increased 17-fold by the end of gestation (P<0.05). Birth weight of calves was positively correlated with blood-flow volume (r=0.34) but negatively correlated with the resistance index (r=-0.45). There were no significant differences between male versus female calves (at any stage of gestation) in the resistance, time-average maximum velocity, and volume indices (P>0.05). In conclusion, arterial blood flow was monitored with transrectal Doppler sonography in both median uterine arteries weekly throughout pregnancy in cattle; this could be very valuable for monitoring pregnancies at high risk for abnormalities of the placenta, fetus or both, e.g. cloned calves.     

Transrectal Doppler sonography of uterine blood flow in cows during pregnancy

Transrectal Doppler ultrasound was used for the noninvasive investigation of uterine blood flow in three cows during pregnancy. The uterine arteries ipsi and contralateral to the conceptus were scanned monthly. Blood flow was reflected by the following parameters: resistance index (RI), time-averaged maximum velocity (TAMV), diameter of the vessel (D) and the volume of blood flow (VOL). RI values were negatively correlated to all other blood flow parameters (P < 0.01). Positive correlations occurred between TAMV, D and VOL (P < 0.0001). While blood flow parameters did not differ between cows (P > 0.05), the month of gestation showed a positive effect on RI and negative effects on TAMV, D and VOL (P < 0.0001). The RI was lower and TAMV, D and VOL higher in the uterine artery ipsilateral to the conceptus (P < 0.05). RI values decreased continuously during the first 8 months of gestation and remained from then until birth at a relatively constant level. While TAMV increased especially in two-thirds of pregnancy, a relatively uniform rise of D was noticed. VOL increased exponentially with stage of gestation. The results show that transrectal Doppler sonography is a suitable, noninvasive method for the examination of uterine blood flow during pregnancy in cows. Using this technique it might be possible in the future to determine the role of uterine blood flow in cows at the risk of abortion.     

The effect of exogenous estradiol benzoate and altrenogest on uterine and ovarian blood flow during the estrous cycle in mares

In recent years, a positive relationship between genital perfusion and fertility has been established; in species other than horses, uterine and ovarian perfusion was improved by exogenous estrogen but impaired by exogenous progestin. The goal of the present study was to investigate the effect of exogenous estrogen and progestin on uterine and ovarian blood flow in cycling mares. Five Trotter mares were examined daily during three estrous cycles. Mares were given no treatment, altrenogest (0.044 mg/kg BW) orally from Day 0 (ovulation) to Day 14 and estradiol benzoate (5mg i.m.) on Days 0, 5, and 10, in three cycles, respectively. There was no difference ( P > 0.05 ) in the length of untreated versus estrogen-treated cycles ( 22.8 +/-1.3 days and 23.2 +/= 1.5 days, respectively), but cycle length was increased (P < 0.05) in progestin-treated cycles (26.0 +/- 1.2). To facilitate comparisons among cycles with different lengths, data from Days 0 to 15 (diestrus) and from Days -6 to -1 (estrus) were analyzed. Transrectal Doppler sonography was used to evaluate blood flow in both uterine arteries and in the ovarian artery ipsilateral to the preovulatory follicle during estrus and ipsilateral to the corpus luteum during diestrus. Blood flow was assessed semiquantitatively using the pulsatility index (PI); high PI values indicated high resistance and a low perfusion and vice versa. An immediate effect of treatments occurred only after the administration of estradiol benzoate on Day 0; uterine PI values decreased (P < 0.05) between Days 0 and 1 and estrogen-treated mares but increased (P < 0.05) at the corresponding time in untreated cycles. Mean PI values for the uterine and ovarian arteries during both diestrus and estrus were higher (P < 0.05) in estrogen-treated versus untreated mares. Furthermore, mean uterine PI values during diestrus and estrus were higher (P< 0.05) in altrenogest-treated versus untreated mares. Neither estrogen nor altrenogest treatments had a significant immediate effect on ovarian PI values. Compared to untreated cycles, mean ovarian PI values were elevated (P < 0.05) only in the estrus following altrenogest administration. In conclusion, exogenous estrogen and progestin both decreased genital perfusion in cycling mares.     

Blood flow in ductus venosus in early uncomplicated pregnancy

The ductus venosus is the very important part of fetal venous circulation. It plays a central role in return of venous blood from the placenta. This unique shunt carries well-oxygenated blood from the umbilical vein through the inferior atrial inlet on its way across the foramen ovale. Using Doppler ultrasound, it is possible to assess the blood flow in fetal vessels including ductus venosus. It is observed, in animal and human studies, that the typical waveform for blood flow in ductus venosus in early pregnancy can be different depending on numerous conditions e.g. fetal karyotype. This study is performed to assess the physiologic parameters of blood flow in ductus venosus in uncomplicated early pregnancy. Material and Methods: 404 women were examined between 11+0 and 13+6 weeks (+ days) of gestation by ultrasound. Fetal crown-rump length (CRL) was measured to assess the gestational age. The assessment of risk of fetal abnormalities was based on nuchal translucency (NT) measurement. The ductus venosus blood flow with color and spectral Doppler was obtained in all patients. The following features were assessed: pulsatility index (PI), and direction of flow (positive/negative) during atrial contraction (wave A). All cases were followed up to 22 weeks of gestation when the control scan was performed. Results and conclusions: 30 cases were excluded from the uncomplicated group due to: high risk of fetal abnormalities, fetal loss, confirmed fetal abnormalities and utero-placental pathology. 374 women were considered as uncomplicated pregnancy. In both uncomplicated and complicated groups the mean values for pulsatility index (PI) were established. The mean PI value in uncomplicated pregnancies was: 0.91 (SD +/- 0.32). No significant differences between groups were noticed. In 370 cases of uncomplicated pregnancy the A wave direction was positive but in 1.1% of cases the reverse flow in atrial contraction was observed.     

Effect of intrauterine administration of oestradiol on postpartum uterine bacterial infection in cattle

After parturition fewer first dominant follicles are selected in the ovary ipsilateral to the previously gravid uterine horn in cattle. However, the presence of a large oestradiol-secreting follicle in the ipsilateral ovary is a predictor of fertility, possibly due to a localised effect of oestradiol which increases the rate of elimination of the ubiquitous uterine bacterial contamination that occurs after calving. The present study tested the hypothesis that oestradiol reduces uterine bacterial contamination when administered into the uterine lumen around the expected time for selection of the first postpartum dominant follicle. Animals were infused with saline (n=15) or 10mg oestradiol benzoate (n=15) into the previously gravid uterine horn on Days 7 and 10 postpartum. Peripheral coccygeal blood samples were collected daily and oestradiol concentrations measured by radioimmunoassay (RIA). Uterine lumen swabs were collected 7, 14 and 21 days postpartum for aerobic and anaerobic culture, bacteria were identified and growth scored semi-quantitatively. Plasma oestradiol concentrations were higher for treated animals between Days 7 and 14 (1.4+/-0.1 versus 2.0+/-0.2 pg/ml, P<0.05). Control animals had a similar bacterial growth score on Days 7 and 14, with a lower value on Day 21 (5.7+/-1.0 and 6.1+/-0.7 versus 0.3+/-0.1, P<0.05). However, treated animals had a surprising higher bacterial load on Day 14, than on Days 7 or 21 (7.1+/-0.9 versus 4.0+/-0.6 or 3.6+/-0.6, P<0.05). The increased score was attributable to more pathogens associated with endometritis on Day 14 than Day 7 (5.1+/-1.0 versus 2.5+/-0.5, P<0.05), in particular Prevotella melaninogenicus (1.5+/-0.5 versus 0.7+/-0.2, P<0.05) and Fusobacterium necrophorum (1.5+/-0.4 versus 0.3+/-0.2, P<0.05). In conclusion, administration of oestradiol into the uterine lumen surprisingly increased uterine pathogenic anaerobic bacterial contamination. Thus, it is unlikely that increased fertility associated with a first dominant follicle in the ipsilateral ovary is a consequence of the elimination of bacterial contamination by ovarian oestradiol.     

Velocity profiles in the human ductus venosus: a numerical fluid structure interaction study

The veins distributing oxygenated blood from the placenta to the fetal body have been given much attention in clinical Doppler velocimetry studies, in particular the ductus venosus. The ductus venosus is embedded in the left liver lobe and connects the intra-abdominal portion of the umbilical vein (IUV) directly to the inferior vena cava, such that oxygenated blood can bypass the liver and flow directly to the fetal heart. In the current work, we have developed a mathematical model to assist the clinical assessment of volumetric flow rate at the inlet of the ductus venosus. With a robust estimate of the velocity profile shape coefficient (VC), the volumetric flow rate may be estimated as the product of the time-averaged cross-sectional area, the time-averaged cross-sectional maximum velocity and the VC. The time average quantities may be obtained from Doppler ultrasound measurements, whereas the VC may be estimated from numerical simulations. The mathematical model employs a 3D fluid structure interaction model of the bifurcation formed by the IUV, the ductus venosus and the left portal vein. Furthermore, the amniotic portion of the umbilical vein, the right liver lobe and the inferior vena cava were incorporated as lumped model boundary conditions for the fluid structure interaction model. A hyperelastic material is used to model the structural response of the vessel walls, based on recently available experimental data for the human IUV and ductus venous. A parametric study was constructed to investigate the VC at the ductus venosus inlet, based on a reference case for a human fetus at 36 weeks of gestation. The VC was found to be \(0.687\,\pm \,0.023\) (Mean \(\pm \) SD of parametric case study), which confirms previous studies in the literature on the VC at the ductus venosus inlet. Additionally, CFD simulations with rigid walls were performed on a subsection of the parametric case study, and only minor changes in the predicted VCs were observed compared to the FSI cases. In conclusion, the presented mathematical model is a promising tool for the assessment of ductus venosus Doppler velocimetry.     

Relationships between ovarian blood flow and ovarian response to eCG-treatment of dairy cows

The goal of the present study was to investigate ovarian blood flow and ovarian response in cows undergoing a gonadotropin treatment to induce a superovulatory response, using transrectal colour Doppler sonography. Forty-two cows including 19 cross-bred, 14 German Holstein and 9 German Black Pied cows were examined sonographically before hormonal stimulation on Day 10 of the oestrous cycle, three days after administration of eCG (Day 13) and seven days after artificial insemination (Day 7(p.i.)). After each Doppler examination, blood was collected for determination of total oestrogens (E) and progesterone (P4) in peripheral plasma. The blood flow volume (BFV) and pulsatility index (PI), which is a measure for blood flow resistance, were determined in the ovarian artery, and B-mode sonography was used to count dominant follicles and corpora lutea. Important criteria to assess the ovarian response following the hormonal treatment were the number of follicles >5mm in diameter on Day 13 and the number of corpora lutea on Day 7(p.i.) per cow. The number of follicles ranged from 2 to 61 (mean+/-S.E.M.: 17.5+/-1.7) and corpora lutea from 0 to 50 (mean+/-S.E.M.: 17.0+/-1.6). The BFV increased from 28.4 to 45.0 ml/min between Days 10 and 13 and reached a maximum of 108.5 ml/min on Day 7(p.i.) The PI decreased from 6.25 on Day 10 to 4.70 on Day 13 and to 2.10 on Day 7(p.i.) The BFV and PI on Day 13 did not correlate with the number of follicles (P>0.05). However, on Day 7(p.i.) the number of corpora lutea correlated positively with the BFV (r=0.64; P<0.0001), and an inverse relationship was found for the PI (r=-0.51; P=0.0005). There were no correlations (P>0.05) between the BFV and PI on Day 10 and the number of follicles on Day 13 or the number of corpora lutea on Day 7(p.i.) Results of the present study show that in cows, a hormonal treatment to induce a superovulatory response yielded a marked increase in BFV and a marked decrease in PI in the ovarian artery. However, there was no correlation between BFV and PI in the ovarian arteries before hormonal stimulation and the number of follicles and corpora lutea that developed after stimulation. Thus BFV and PI measured in the ovarian arteries have limited diagnostic value to predict the outcome of a gonadotropin treatment.     

Transrectal Doppler sonography of uterine and umbilical blood flow during pregnancy in mares

Transrectal color Doppler sonography was used to investigate uterine and umbilical blood flow during pregnancy (duration, 46-48 weeks) in four mares. The resistance index (RI) and blood flow volume (VOL) of the uterine arteries ipsilateral and contralateral to the conceptus, and the presence of an early diastolic notch in the Doppler wave, were evaluated every 4 week throughout pregnancy. Fetal blood flow was calculated semiquantitatively every 2 week (from 20 to 40 weeks), using the RI of the umbilical arteries. During the entire period of investigation, there were no significant individual variations in uterine RI and VOL nor differences between the two uterine arteries. Mean RI decreased by more than half during pregnancy from 0.89 +/- 0.01 to 0.39 +/- 0.03, and mean VOL increased almost 400-fold from 69 +/- 37 to 27,467 +/- 8851 ml/min. There were relationships (P<0.0001) between week of pregnancy (x) and RI as well as VOL. These were described by the equations RI=0.938-0.150 ln(x) and VOL (ml/min)=7.621x(2.157). Log transformed total estrogen (TE) were related to RI (r=-0.879; P<0.05) as well as to VOL (r=0.888; P<0.05). The notch in the Doppler wave of the uterine artery disappeared between 18 and 26 weeks. There was a correlation (P<0.0001) between week of gestation (x) and RI values of the umbilical arteries; this was described by the equation RI=1.763-0.071x+0.001x2. Further studies are needed to determine whether transrectal color Doppler sonography could be used to identify mares at risk of abortion.     

The effect of exogenous estradiol on litter size in a typical swine herd

Fifty-six female pigs (12 gilts, 26 primiparous and 18 multiparous sows) were bred and assigned to receive either corn oil (vehicle; n=28) or estradiol-17beta (2 mg/day; i.m.; n=28) on Days 12 and 13 (Day 0 = first day of estrus) to determine if exogenous estradiol could improve litter size in swine. Though litter size of the females farrowing was not increased with estradiol treatment (vehicle versus estradiol, 9.7 +/- 0.8 versus 10.1 +/- 1.8 live pigs born, respectively), more females in this group remained pregnant (vehicle versus estradiol, 6 versus 1 recycled, respectively; P<0.05). Litter size, expressed as the number of pigs born per-female-bred, was therefore increased with exogenous estradiol (vehicle versus estradiol, 7.6 +/- 0.8 versus 9.8 +/- 0.7 live pigs born, respectively; P<0.05). Some of these estradiol- treated females produced smaller (P<0.05) litters and this may be of concern in herds experiencing low fertilization/conception rates. Overall 60 more pigs were born alive to females in the estradiol-treated group than to the control group females. This experiment demonstrated that supplemental estradiol treatment on Days 12 and 13 assisted in maintenance of pregnancy and thereby increased litter size on a per-female-bred basis.     

Effect of pentoxifylline treatment on testicular perfusion and semen quality in Miniature horse stallions

The objective was to investigate the effects of pentoxifylline (PTX) on testicular perfusion and sperm production in stallions. In a preliminary study, six mature Miniature horse stallions were given 0, 8.5, or 17.0 mg/kg of PTX orally, twice daily, for 3 d. Total Arterial Blood Flow Rate (TABFR) was higher (P < 0.05) in all treated versus control stallions during and after treatment. Two months later (during the fall and winter), the same stallions received either 0 or 17 mg/kg of PTX orally, twice daily for 60 d. Resistance and pulsatility indices (RI and PI, respectively) decreased in PTX-treated stallions between Treatment 1 and Post-treatment periods. Arterial diameter, as well as Total Arterial Blood Flow (TABF), decreased in controls between Baseline and Treatment 1 (P < 0.05). A similar decrease in arterial diameter was delayed in Group TREATED, but reached significance during Post-treatment (P < 0.05), whereas TABF did not change in this group. Furthermore, TABFR had a transient tendency to increase during Treatment 1 (P < 0.1), whereas it steadily decreased in controls and reached significance in the Post-treatment period (P < 0.05). Both RI and PI were negatively correlated with end diastolic velocity (EDV) in both groups (P < 0.0001). There were positive correlations between RI and peak systolic velocity (PSV) in treated stallions during Treatment 1 (RI: r = 0.53, P = 0.021; PI: r = 0.59, P = 0.007). Also, there were negative correlations between Time Averaged Maximum Velocity (TAMAX) and Doppler indexes in treated stallions during Treatment 2 period (RI: r = −0.49, P = 0.006; PI: r = −0.47, P = 0.008), and during Post-treatment periods (RI: r = −0.40, P = 0.049; PI: r = −042, P = 0.039). Transient hydrocele occurred in all treated stallions (a potential complication of high-dose PTX). Semen end points were not significantly affected by PTX treatment. In conclusion, PTX delayed the seasonal decrease of testicular perfusion in stallions. Sperm quality and quantity were not significantly affected; perhaps they would have been enhanced by prolonged treatment.     

A comparative biomonitoring study of populations residing in regions with low and high risk of lung cancer using the chromosome aberration and the micronucleus tests

Chromosome aberration (CA) and micronucleus (MN) tests were performed in peripheral blood lymphocytes from people residing in two districts of Chiang Mai, Thailand, a high-risk area, Saraphi (n=107), where the lung cancer incidence is three-fold higher than in a low-risk area, Chom Thong (n=118). The percentage of cells with CAs was significantly lower in the Saraphi population than in the Chom Thong population (0.47+/-0.91 versus 1.04+/-1.18, P=0.0001) as was the percentage of CAs (0.49+/-0.91 versus 1.08+/-1.21, P<0.0001) and the mitotic indices (1.25+/-0.44 versus 1.33+/-0.33, P=0.025). The frequency of MN in binucleated (BN) cells, however, was significantly higher in the Saraphi population (12.01+/-3.57 versus 9.99+/-3.11, P<0.0001) as was the percentage of BN cells with MN (1.14+/-0.31 versus 0.93+/-0.23, P<0.0001). There was no difference in the nuclear division indices (1.49+/-0.07 versus 1.47+/-0.11, P=0.1759) between the two populations. With regard to the effect of confounding factors, it was found that cigarette smoking influenced both CA and MN frequencies, and that the chewing of fermented tea leaves or betel nuts affected CA and sex affected MN frequencies. An increasing of CA and MN frequencies were seen in smokers and chewers over non-smokers and non-chewers, with CA frequencies being higher in Chom Thong smokers and chewers and MN frequency being higher in Saraphi smokers. However, pesticide exposure and alcohol consumption had no impact on CA and MN frequencies. Due to the conflicting results obtained in the two tests, we cannot make a clear statement regarding the potential effects of the environmental exposures in the two study populations.     

Corpus luteum development and function and relationship to pregnancy during the breeding season in the Mediterranean buffalo

The aim of this study was to ascertain corpus luteum (CL) development and function in buffaloes synchronized and mated by artificial insemination (AI) during the breeding season. Italian Mediterranean buffalo cows (n = 43) at 86.5 ± 2.7 days postpartum were synchronized by the Ovsynch-TAI Program and inseminated using frozen thawed semen at 20 and 44 h after the second injection of GnRH. The CL dimensions (diameter and area) and blood flow were examined on Days 5, 10, 15, 20, and 25 after AI by realtime B-mode/colour-Doppler ultrasonography. The resistive index (RI), pulsatility index (PI) and time average medium velocity (TAMV) were recorded at each time, together with CL dimensions. Blood samples were taken on the days of ultrasonography for progesterone (P4) assay by RIA. Data were grouped into pregnant or non-pregnant and retrospectively analyzed by repeated measure ANOVA and correlation analyses. Dimensions of the CL on Days 10, 20, and 25 after AI were greater (P < 0.01) in buffaloes pregnant on Day 45 (n = 18) compared with non-pregnant buffaloes (n = 25). The former buffaloes also showed a greater (P < 0.01) rate of CL growth between Days 5 and 10 after AI. Blood flow to the CL on Day 10 after AI showed a higher TAMV (P < 0.01) and lower RI (P < 0.05) in pregnant buffaloes compared with non-pregnant buffaloes. Negative correlations were observed on Day 10 after AI between CL diameter and RI (r = −0.61; P < 0.01) and PI (r = −0.60; P < 0.01); P4 concentrations and RI (r = −0.46; P < 0.02); and RI and pregnancy (r = 0.45; P < 0.02). Positive correlations were observed between pregnancy and CL size (r = 0.54; P < 0.01), ΔCL diameter between Days 5 and 10 (r = 0.52; P < 0.01), ΔCL area between Days 5 and 10 (r = 0.48; P < 0.015), and ΔP4 between Days 5 and 10 (r = 0.50; P < 0.01). Based on these findings it is concluded that the period between Day 5 and 10 is very important for CL growth and crucial in evaluating pregnancy. Accordingly, the assessment of CL parameters during the period from Day 5 to Day 10 after AI might be used to predict the likelihood of an ongoing pregnancy.     

Cyclic changes in endometrial echotexture of cows using a computer-assisted program for the analysis of first- and second-order grey level statistics of B-Mode ultrasound images

The aim of this study was to test the suitability of a computer-assisted echotexture analysis program for analysing first- and second-order grey level statistics of grey levels of B-Mode ultrasound images to examine morphologic changes in the endometrium during oestrous cycle in cows. Four Simmental cows were examined for two consecutive oestrous cycles. Echotexture of the endometrium was assessed by mean grey level (MGL) and homogeneity (HOM) of digitised B-Mode images of the uterine body and both uterine horns. As there were no differences (P>0.05) in MGL and HOM, respectively, between the images of the uterine body and the uterine horns, the mean values of all endometrial images were used for subsequent analyses of MGL and HOM. The factor 'day of oestrous cycle' showed a highly significant (P<0.0001) effect and the factor 'cow' showed a significant (P<0.05) effect on MGL and HOM. No differences (P>0.05) in both echotexture parameters were measured between oestrous cycles within cows. MGL was negatively related to HOM (r=-0.66; P<0.0001). Low MGL and high HOM occurred on Day 0 (=ovulation) and between Days -3 and -1. While MGL was consistently (P>0.05) low between Days -3 and -1, significant changes of HOM with maximum levels on Day -2 (P<0.05) were observed during this time. MGL was consistently (P>0.05) high between Days 4 and 13 while HOM was consistently (P>0.05) low between Days 2 and 13. From Day -3 to Day -1 (r=0.48; P<0.05) plasma oestrogen levels were correlated with HOM, but not with MGL (P<0.05). The results of this study show that changes in endometrial morphology of cows can be measured using a computer-assisted texture analysis program.     

Assessment of feline fetal viability by conceptus echobiometry and triplex Doppler ultrasonography of uterine and umbilical arteries

The aims of the present study were to: (1) evaluate blood flow in the uterine (UA) and umbilical arteries (Uma) in the pregnant queen, by measuring the resistive index (RI) and pulsatility index (PI); (2) to note the presence or absence of the early diastolic notch and diastolic flow in the UA and Uma flow waveforms, respectively; and (3) perform conceptus echobiometry for fetal growth assessment during pregnancy. Eight healthy pregnant domestic Brazilian Shorthair queens were examined from Days 10 to 50 after mating (mating=Day 0). Triplex Doppler and B-mode ultrasonography were used to assess blood flow and conceptus echobiometry. All pregnancies ended with a normal parturition and birth of live kittens. Prior to parturition, all conceptus dimensions increased significantly, whereas RI and PI peaked between Days 33 and 43 followed by a decrease (P<0.05). The PI least on Day 50. The RI and PI of Uma decreased (P<0.05) during two periods in the fetal development, i.e. from Days 22 to 40 (0.79 ± 0.01 and 1.64 ± 0.04), and from Days 41 to 50 (0.75 ± 0.01 and 1.39 ± 0.05), representing the increased Uma perfusion. Both the complete disappearance of the early diastolic notch in the UA, and the appearance of diastolic flow in the Uma occurred on Day 42 ± 1. It was concluded fetal echobiometry, UA and Uma perfusion, were important end points to assess fetal viability in queens. Furthermore, the current reference values provided a baseline for monitoring normal and abnormal pregnancies in queens.