Retention Of Fetal Membranes Research Articles

Activity of hyaluronidase in placental tissues from cows with and without retained fetal membranes.

Hyaluronidase, a proteoglycan-degrading enzyme, may have an influence on collagenolysis in bovine placenta and take part in the separation processes of the placenta in cows. There was, however, no evidence concerning the activity of this enzyme in those tissues. The experiment was performed on cows divided into two groups as follows: A, placenta not retained (n = 16); and B, placenta retained (n = 9). The activity of the enzyme was measured using a spectrophotometric method and zymography. The results showed statistically significant higher activity of hyaluronidase in the maternal and fetal parts of the placenta in cows with a retention of fetal membranes. Further experiments require substrate specificity studies and the presence of regulatory factors of this enzyme in bovine placental tissues.

Prevention of retained placenta by injection of collagenase into umbilical arteries of calves delivered by cesarean section: A tolerance study

In the cow, cesarean section delivery is often followed by retention of fetal membranes. Hypothetically, the retention of fetal membranes could be prevented by intraplacental injections of the enzyme collagenase. However, the infusion of this potent proteolytic enzyme into a uterus traumatized by surgery can lead to uterine damage, including perforation. Thus, the objective of this research was to evaluate tolerance of intraplacental treatment of bacterial collagenase. A cesarean section was performed on 10 experimental cows undergoing induced delivery or diagnosed with dystocia. During the surgical procedure, 200,000 units of bacterial collagenase in 1 L of saline were infused via the umbilical arteries. A cesarean section was also performed on control cows (n = 25) affected by dystocia, but these received no collagenase. The collagenase-treated cows showed no clinical or laboratory signs of abnormality over a 3- to 4-wk observation period post treatment. When membrane retention time was set at 36 h post surgery, 20% of the experimental cows and 60% of the control cows had retained the fetal membranes. It was concluded that intraplacental administration of collagenase during cesarean section is safe. However, treatment effectiveness and economic benefits for commercial application need further study.

Activity of 72-kDa and 92-kDa matrix metalloproteinases in placental tissues of cows with and without retained fetal membranes

This study compared the activity of matrix metalloproteinases (MMP-2 and MMP-9) in retained and non-retained bovine placenta. The activities of MMPs and their zymogens were measured in fetal and maternal placental tissues from control cows (group B) and animals affected with retention of fetal membranes (group A) using a zymography technique on 10 per cent SDS polyacrylamide gels. The activity of proMMP-9 detected only in the maternal part of the placenta was lower in group A than in group B. ProMMP-2 activity was higher in group A than in group B in both tissues. The active forms of MMP-2 were observed in the maternal and fetal part of placenta in group B, but only the 68-kDa form was detected in the placental tissues of group A. The differences in enzyme activity between the groups and the lack of 64- and 60-kDa active forms of MMP-2 in the maternal and fetal parts of the retained placenta may have influenced the hydrolysis of collagen and the proper release of fetal membranes.

Surgical and nonsurgical correction of uterine torsion in New World camelids: 20 cases (1990–1996)

Objective To report clinical findings for New World camelids with uterine torsion and to compare results of 3 methods of correction. Design Retrospective case series. Animals 11 llamas and 3 alpacas with 20 uterine torsions. Procedure Information concerning history, clinical signs, management, and postpartum complications was retrieved from medical records. Information concerning subsequent reproductive performance was obtained by telephone interview of owners. Results Uterine torsion was corrected by celiotomy (n = 7), transvaginal manipulation (5), or rolling the dam (8). Direction of 19 of 20 torsions was clockwise when viewed from the rear. Retention of fetal membranes was reported for 5 camelids that underwent celiotomy, but was not reported in camelids after nonsurgical correction. The uterus prolapsed in 1 llama that underwent celiotomy and in another that underwent the rolling technique. Although 2 camelids that underwent celiotomy subsequently failed to conceive, all camelids treated by nonsurgical techniques conceived. Clinical Implications Uterine torsion in camelids may be diagnosed by methods similar to those used in cattle. Surgical and nonsurgical methods can be used to correct torsion, and postpartum complications are rare when torsion is corrected by a nonsurgical method. (J Am Vet Med Assoc 1997;211:600–602)

Norgestomet implants maintain pregnancy in ovariectomized heifers

Fifty-five heifers were synchronized with norgestomet and estradiol valerate and artificially inseminated approximately 48 h after the removal of norgestomet implants. Ten days after Al, 15 of the heifers were ovariectomized and then two 15 mg norgestomet/silicone implants were implanted subcutaneously on the convex surface of the ear. The norgestomet/silicone implants were changed every 55 ±4 d (mean ange) thereafter, and the last set of implants was removed 273 d after Al. At 44 d after Al, 65% (26/40) of the control heifers and 53% (8/1 5) of the ovariectomized heifers with norgestomet implants were pregnant (P > 0.10). Two pregnancies were lost in ovariectomized heifers treated with norgestomet (44 to 96 d after Al) and a third pregnancy failed in a heifer that lost 1 of 2 implants 65 to 96 d after Al. Ninety-six days after Al implants were removed from 2 pregnant ovariectomized heifers with norgestomet implants. These 2 heifers were open at 116 d after Al. All 3 ovariectomized heifers with norgestomet implants pregnant at 273 d after Al calved an average of 41 h after the removal of the last set of norgestomet/silicone implants. Dystocia (P < 0.05), retention of fetal membranes (P < 0.01), and calf mortality (P < 0.01) were higher for the ovariectomized heifers with norgestomet implants than for the control heifers.

Bovine uterine torsion: 164 hospital referral cases

Uterine torsion is more common in the cow than any other domestic species. The etiopathogenesis of the condition remains open to speculation. Available hospital referral records of bovine uterine torsions (n = 164) were collated, and additional comparisons for season, age and breed were made using the VDMP data base of 24 North American veterinary schools. There was no effect of season. Brown Swiss cows were at a significantly higher risk (P = 0.0001), while Hereford, Angus, and Jersey cows were at a lower risk for uterine torsion when compared with Holstein-Friesian cows, the largest breed population (P = 0.01). Most cows (81%) were at term. Clinical signs of torsion included fever (23%), tachycardia (93%), tachypnea (94%), straining (23%), anorexia (18%) and vaginal discharge (13%). In 34% of the cases the torsion was precervical, with no vaginal involvement being noted. The severity of the torsion was predominately 180 to 270 ° (57%) and 271 to 360 ° (22%). Counter-clockwise torsion was present in 63% of the cases. Vaginal delivery was possible after manual correction (20%) or rolling of the cow (18%). Cesarean section was performed immediately in 35% of the cases, after failed detorsion attempts in 7%, and due to failure of the cervix to dilate following successful correction of the torsion in 20%. Calf birth weights exceeded breed means in 89% of the cases, and a significantly greater proportion (63%) of the fetuses were male. Fetal survival rate was 24% (14% of dead fetuses were emphysematous), and the cow survival rate was 78% (10% were euthanized). The fetal membrane retention rate was 57%. It was found that large term fetuses appear to predispose a cow to uterine torsion.

Cryopreservation of ovine embryos: Slow freezing and vitrification

Retention of fetal membranes (RFM) is believed to be associated with conditions of oxidative stress. In this study, 8-hydroxy-2′-deoxyguanosine (8-OH-dG) was used for the determination of spontaneous oxidative DNA lesions in maternal and fetal parts of bovine retained and nonretained placentas. Placental specimens were collected directly after spontaneous delivery or during cesarean section from cows divided into 6 groups: (A) cesarean section before term without RFM, (B) with RFM, (C) cesarean section at term without RFM, (D) with RFM, (E) spontaneous delivery at term without RFM and (F) with RFM. Isolated DNA was hydrolyzed and analyzed by HPLC; native nucleosides were monitored at 254 nm and 8-OH-dG by electrochemical detection. No significant differences in 8-OH-dG levels between retained and nonretained placental tissues were found in all samples from preterm groups (mean concentrations between 13 and 42 μmol/mol deoxyguanosine (dG)). In the term cesarean section group with RFM a significant increase in 8-OH-dG concentration in DNA from maternal (8-fold) and fetal (18-fold) membranes were detected when compared to the respective nonretained tissues. Also, in the term spontaneous delivery groups maternal nonretained placental tissues showed increased levels of 8-OH-dG in comparison to the respective tissues of the retained placenta group. In placental tissues oxidative DNA lesions appear to be controlled by responsive mechanisms which, possibly following exhaustion, give rise to increased 8-OH-dG levels.

Ovine placenta related to binucleated cells in fetal membrane retention

Placentomes were collected from 28 Iraqi Awassi ewes which had retained their fetal membranes after; (a) normal birth ( n = 6); (b) abortion ( n = 6), (c) dystocia ( n = 10), and (d) Caesarean section ( n = 6). Histologic changes in placentomes obtained from ewes with retained fetal membranes (RFM) after normal birth included vascular changes (edema, hyperemia and hemorrhages), hemosiderin pigmentation, necrosis in the maternal villi and presence of moderate to large numbers of binucleate cells (BNC). In placentomes obtained from ewes having RFM after abortion, there were vascular changes in both maternal and fetal connective tissues. Necrosis and massive bacterial colonies were seen in the caruncles and cotyledons. Few numbers of BNC and infiltration of polymorphonuclear and mononuclear cells in the caruncles and cotyledons were observed. The changes in placentomes obtained from ewes having RFM after dystocia (treated by assisted delivery) included the presence of vascular changes, hemosiderin pigmentation, moderate degree of necrosis and few bacterial colonies in the caruncles and cotyledons. Moderate numbers of BNC were observed. On the other hand, in cases of dystocia (treated with a Caesarean section), vascular changes, moderate degrees of necrosis and few numbers of bacterial colonies were observed in caruncles and cotyledons and only few BNC. It was concluded that BNC are involved in the process of placental separation in ewes.

Successful treatment of retained placenta with umbilical cord injections of collagenase in cows

Summary Fetal membranes usually are released from the uterus between 2 and 6 postpartum hours. However, in a substantial percentage of cows (11%), fetal membranes are retained for several days. In part, failure of collagen breakdown seems to be related to retention of fetal membranes. Injections of 200,000 U of bacterial collagenase in 1,000 ml of physiologic saline solution via umbilical arteries (1 or 2) between 24 and 72 hours of retention caused release of retained fetal membranes in 23 of 27 cows (85%) with noninduced retained fetal membranes and in 10 of 14 cows (71%) with experimentally induced retained fetal membranes, within 36 hours after injection. Controls (n = 36) did not release retained fetal membranes within this time. Injections of collagenase via a jugular vein (2.2 × 106 U in 1,000 ml of physiologic saline solution), administered over a 30-minute period, caused release of retained fetal membranes within 36 hours in 3 of 6 cows with experimentally induced retained fetal membranes. Clinical complications did not follow treatments with collagenase. Umbilical injections of bacterial collagenase were highly effective in the treatment of retained fetal membranes in cows. The procedure is simple, safe, affordable, and can be completed in 25 minutes.

Factors Influencing Periparturient Neutrophil Function in Dairy Cows

Many diseases and conditions of economic importance in dairy cattle occur most commonly during the immediate postpartum period. Kehrli et al1 found neutrophil function to be impaired during this period. These authors described periparturient depression of random migration, bacterial ingestion, chemiluminescence, iodination and cell-mediated cytotoxicity. In this study, heifers which had postparturient intramammary infections also suffered the most severe peripartum alteration of neutrophil function. This supports the contention that neutrophil function is an important element in the first-line defense of the body against bacterial infection. Impaired neutrophil function during the periparturient period may contribute to the peculiarly high incidence of bacterial infections during this period.1&#x0D; The incidence of disease in periparturient cows is further influenced by other factors, including parity and the occurrence of retained fetal membranes (RFM). Epidemiological studies have linked advancing parity to an increasing incidence of several disorders. Thus the lactational incidence risk of retained fetal membranes and ovarian cysts increased with advancing parity in a study of over 61,000 lactations in a population of Finnish Ayrshires.2 A separate study found that advancing age of dairy cows was associated with increased incidence of retained fetal membranes and mastitis. Retained fetal membranes, in turn, predispose to a host of other reproductive disorders including metritis, silent heat and undiagnosed infertility2 and mastitis.4,5 Even when controlling for the effects of specific, diagnosed diseases, advancing parity was associated with reduced reproductive efficiency. These authors speculate that this may be related to subclinical reproductive tract lesions. In itself, RFM is relatively innocuous. The retained membranes are unsightly, often fetid, and aesthetically objectionable for many milkers, but the effect of uncomplicated RFM on the cow is minimal. The major significance of RFM is in the mediation of more severe conditions. Thus, cows which have suffered retention of fetal membranes are at significantly increased risk for developing metritis2,3,7, ketosis3, mastitis2,4,5 and even subsequent abortion in the following pregnancy.2 Schukken, Erb and Smith5 studied the relationship between RFM and mastitis in a population of commercial dairy cows. They found that cows which retained the fetal membranes were at a higher risk (relative risk= 1.5) of developing mild mastitis, and at a much higher risk (relative risk = 5.4) of developing severe mastitis with systemic manifestation than were cows not retaining the membranes. A further finding was that longer duration of placental retention was associated with greater likelihood of mastitis. In a follow-up study in a hospital-based population, this group confirmed these results.4 These authors speculate that the relationship between retained placenta and mastitis is mediated by deficient peripartal peripheral neutrophil phagocytic activity.&#x0D; In 1984 Gunnink proposed that deficient neutrophil activity was a factor in the pathogenesis of RFM in cattle.8-10 He showed that circulating leukocytes from cows with RFM showed diminished chemotactic responses to cotyledon suspensions in vitro.8 He further demonstrated that this impaired chemotactic response existed before parturition9 and that it persisted at least 10 days into the post-partum period.10 Heuwieser and Grunert11 have also reported impaired neutrophil migration in cows which retained fetal membranes.&#x0D; We therefore designed experiments to determine whether periparturient neutrophil function was influenced by parity of the cow or by RFM as part of a project aimed at illuminating pathophysiological factors with epidemiological observations.

Cellular changes in the peripartum bovine fetal placenta related to placental separation

Binucleate giant cells (BNC) decline in number and viability peripartum if the placenta is subsequently released normally. This suggests an involvement of BNC destruction in fetal membrane separation in the cow. Dexamethasone induction of parturition may result in fetal membrane retention through a stabilization of the BNC (possibly the BNC plasma membranes). Prostaglandin F2a treatment in vitro induced a loss of BNC when these were obtained from cows which subsequently retained the fetal membranes for a longer than normal interval. Overall, our results indicate an involvement of BNC loss and breakdown in placental separation and a possible involvement of prostaglandins and glucocorticoids in modulating this process.

Effect of fenprostalene on postpartum myometrial activity in dairy cows with normal or delayed placental expulsion

Postpartum myometrial response to fenprostalene (1 mg subcutaneously) was determined using strain gauge transducers (SGTs) in Holstein cows with normal or delayed placental expulsion. In six cows, parturition was induced using dexamethasone (20 mg intramuscularly) and five of these developed fetal membrane retention (FMR). A further six cows were allowed to calve spontaneously and one developed FMR. Shortly after calving, four SGTs were sutured to the greater curvature of the previously gravid uterine horn, dividing it approximately into thirds. Eight cows (four FMR, four FME (fetal membranes expelled)) each received fenprostalene at 12, 36, 60, and 84 h post partum. The remaining animals (2 FMR, 2 FME) each received physiological saline (2 ml subcutaneously) at these same treatment times. Fenprostalene produced no significant changes in myometrial activity on any of days 1–4 post partum. Furthermore, there were no significant cumulative effects due to repeated daily injection of fenprostalene. The presence of FMR was accompanied by an increased frequency of uterine contractions ( P < 0·005), and greater ( P < 0·025) and more rapid ( P < 0·025) tubo-cervical contraction wave propagation—regardless of treatment.

Peripartum changes in the bovine placenta related to fetal membrane retention

To understand fetal membrane retention in dairy cattle, we examined these tissues in the immediate peripartum period before tissue separation. Placentomes were collected at 270–280 d of gestation from pre-partum Holstein cows (n = 5) and at 1, 3, 6, and 12 h postpartum from a) cows releasing fetal membranes in less than 12 h (n = 7), b) cows retaining fetal membranes for more than 12 h (n = 5), and c) cows induced to calve with dexamethasone (releasing membranes in more than 12 h; n = 5). Subjective evaluations of necrosis, distribution, and condition of binucleate giant and of principal cells were made. Necrotic foci and binucleate giant cells were counted for each interval for which tissue was available. Necrosis, existing prepartum, was identical to that observed at 1 h postpartum in all treatment groups (P > 0.05). Necrosis gradually increased in all treatment groups with time (P < 0.05); thus necrosis is unrelated to initiation of calving and is indirectly related to fetal membrane retention. Many binucleate giant cells were observed prepartum. In cows releasing fetal membranes normally, a significant (P < 0.05) decline in these cell numbers had occurred by 1 h postpartum. When fetal membrane retention occurred, no such decrease in binucleate giant cells was observed before 12 h postpartum. Loss of binucleate giant cells appears necessary for, or must occur with, separation of fetal membranes.

Bovine leptospirosis: some clinical features of serovar hardjo infection.

During an investigation of natural in utero infection of cattle by Leptospira interrogans strains, infection (almost entirely caused by serovar hardjo) was diagnosed in 57 per cent of 505 calves (472 aborted fetuses, 20 stillborn calves and 13 perinatal deaths) examined over a six-year period. The prevalence of leptospire-infected fetuses showed a seasonal increase in September, October and December and was significantly higher in fetuses aborted by dairy cows than in fetuses aborted by beef cows. The majority of infected fetuses were aborted from the sixth month of gestation onwards. Cows which aborted infected fetuses had not previously exhibited overt signs of agalactia. There was an association between leptospiral infection and retention of fetal membranes.

Effects of Ovariectomy during Pregnancy and of Prematurely Induced Parturition on Progesterone, Estrogens, and Calving Traits

Seven cows and one heifer were ovariectomized bilaterally on day 218 of gestation. Twelve intact peers served as controls until day 266 when six were treated with 25mg of estradiol-17β to induce birth prematurely. The objective was to compare profiles of ovarian steroids in blood plasma and urine under experimental conditions known to cause dystocia and retention of fetal membranes more than 12h. Ovariectomy caused an immediate decrease in progesterone of blood plasma to less than 1ng/ml in 4 days. Estrogens in plasma and urine were not changed significantly from controls at similar stages of gestation except for two ovariectomized cows that calved at 251 and 257 days of gestation. In the latter cows, urinary excretion of total estrogen increased to greater than controls coincident with decreased progesterone and about 5 days prior to any increase in estrogens of plasma. Among the remaining ovariectomized cows, two aborted on days 222 and 232 and four calved between days 269 and 278. Four of eight ovariectomized cows had dystocia, and all retained the fetal membranes as did the six peers induced to calve prematurely on day 268 of gestation or 42±2h after treatment with dexamethasone and estradiol-17β. Progesterone increased gradually from .8ng/ml on day 222 of gestation to over 1.5ng/ml in ovariectomized cows that did not calve prior to day 251. Because both groups of treated cows calved earlier in gestation, they averaged lower in estrogens prepartum than control cows. Fetal membranes may be retained if the circulating estrogens, principally estradiol-17β and estrone, remain low until at least 4 days prepartum. Additionally, if progesterone in plasma is chronically low for several weeks prepartum as in the ovariectomized cows, dystocia may occur.

Immunologie Methods for the Detection of Humoral and Cellular Immunity

A variety of immunologic techniques have been introduced during the past few years. Many of these techniques are being applied to clinical specimens in an attempt to help the practicing veterinarian make a diagnosis. The introduction of new techniques requires extensive testing with clinically normal and diseased patients. It is essential for the practicing veterinarian to understand that the techniques available for the detection of immunologic disorders in the dog and cat are not routine diagnostic procedures and that adequate information has not been developed for any of the techniques described to assure the clinical significance of either positive or negative results (Table 3). This should not discourage the practitioner from submitting samples, but should encourage him or her to question the significance of those results and to attempt to correlate them with history and clinical signs before arriving at a final diagnosis.

副腎皮質ホルモンにより人工分娩させたウシ長期在胎の一症例

Parturition was induced in a cow on the 307th day of pregnancy, or 67 hours after the 2nd intramuscular injection of 20 mg of dexamethasone. Fetal membrane retention was observed. The calf was alive at the time of delivery. It had an opening in the skull with a soft tissue protrusion. The pituitary gland, cerebellum, and cerebrum were absent. Adrenal hypoplasia was noticed.The reproductive steroids determined by radioimmunoassay showed the same patterns as observed in the normal parturition by other researchers, except that a characteristically low level of serum cortisol was seen in the newborn calf and a low level of serum estrogen in the cow around parturition.

Retention of the fetal membranes in cattle

An investigation of the possible significance of 'stress' as a factor in the retention of bovine fetal membranes has been carried out, together with the investigation as to the possible variation of progesterone levels at parturition, as a cause of retention. No evidence of abnormal progesterone levels has been established, but from the evidence it is concluded that retention may well be yet another example of production disease.