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Biomedical subjects

E D Watson

Publications and source records attributed to E D Watson.

At least 109 records · Page 6Linked to original sources
PubMed1988

Opsonins in uterine washings influencing in vitro activity of equine neutrophils.

Uterine washings were found to promote neutrophil mediated killing of Streptococcus zooepidemicus. Depletion of complement and/or specific antibody from the washings significantly reduced bactericidal activity. Phagocytosis of yeast by uterine washings was complement dependent. Inhibition of the classical pathway significantly reduced opsonic activity indicating that, in addition to direct activation via the alternate pathway, antibody may also be involved in yeast phagocytosis.

Animals↗
PubMed1988

Changes in the concentrations of steroids and prostaglandin F in preovulatory follicles of the mare after administration of hCG.

Fluid was aspirated from the preovulatory follicle of Group 1 mares (N = 6) when follicles reached 32-34 mm in diameter. Group 2 mares each received an i.v. injection of hCG when the preovulatory follicle reached 35 mm. Aspiration of follicular fluid was performed 28-32 h after treatment. Follicular fluid was aspirated from Group 3 mares 28-32 h after the preovulatory follicle reached 35 mm in diameter. Concentrations of progesterone were significantly higher in follicular fluid from Group 2 mares than in that from mares in Groups 1 and 3. Testosterone was significantly higher in follicular fluid from Groups 2 and 3 than in Group 1 mares. There were no significant differences among groups in concentrations of oestradiol and prostaglandin F (PGF) in follicular fluid.

Animals↗
PubMed1988

Effect of exogenous ovarian steroids on the uterine luminal prostaglandins in ovariectomised mares with experimental endometritis.

Prostaglandins (PGs) F and E2 were measured in lavage fluid from the uterus of ovariectomised mares after experimental induction of uterine inflammation. Treatment with progesterone alone, or progesterone followed by oestradiol, significantly increased the concentrations of these PGs in the lavage compared with mares treated with oestradiol or control mares. Ovarian steroids, therefore, influenced uterine PG synthesis in response to an inflammatory stimulus. To determine whether the uterine lavage procedure might contribute to the concentrations of prostaglandins in the lavage, the procedure was also performed on six intact mares. With the exception of washings obtained at luteolysis, uterine concentrations of PGF (measured as the plasma metabolite 15-keto-13,14-dihydro PGF2 alpha) had returned to prewashing levels within 30 minutes of the start of uterine lavage. Lavage was therefore unlikely to have influenced the concentrations of prostaglandins in the lavage fluid.

Animals↗
PubMed1987

Effect of factors associated with insemination on calving rate in dairy cows.

The results of 7569 inseminations performed on 6007 cows in 94 dairy herds were used to investigate the relative importance of time of insemination, bull and inseminator on calving rates in dairy cows. Although the time of insemination in relation to the first observation of oestrus was shown to have some effect, the effect was minimal during the first 24 hours. The maximum difference in expected calving rates between cows served with semen from groups of bulls with a history of either low or high fertility was 20 per cent, and the maximum difference in expected calving rate between cows inseminated by groups of inseminators who had consistently achieved either low or high fertility was 13 per cent.

Animals↗
PubMed1987

Cellular and humoral defence mechanisms in mares susceptible and resistant to persistent endometritis.

Both random and directional migration of blood neutrophils from 9 mares susceptible to persistent endometritis were significantly less (p less than 0.05) than neutrophils from 8 resistant mares. Serum from susceptible mares had significantly more (p less than 0.01) chemotactic activity than serum from resistant mares. Although phagocytosis of yeast blastospores by blood neutrophils from 4 resistant and 3 susceptible mares was similar, uterine neutrophils from susceptible mares were significantly worse (p less than 0.01) at phagocytosis than uterine neutrophils from resistant mares. Uterine washings from 17 susceptible mares were significantly better at opsonising yeast blastospores than washings from 14 resistant mares; however, washings from both groups had a similar ability to promote killing of S. zooepidemicus by neutrophils. When an immunologically non-specific endometritis was induced, washings from 3 susceptible mares were significantly worse at promoting bactericidal activity by 144 h than washings from 4 resistant mares (p less than 0.01). Haemolytic complement activity was significantly greater (p less than 0.001) in washings from 17 susceptible mares than from 14 resistant mares. Induction of acute endometritis resulted in high levels of haemolytic complement activity in 2 of 3 susceptible mares at 24 and 144 h, but only in small increases in 4 resistant mares. Thus, some abnormalities in neutrophil function were detected and a possible defect in promotion of neutrophil bactericidal activity by uterine secretions from susceptible mares but there was no evidence for any deficiency in haemolytic complement activity.

Animals↗
PubMed1987

Perinatal factors and the development of chronic lung disease in preterm infants: a case control study.

A case control study of neonates was performed to determine those factors contributing to the development of chronic lung disease (CLD). During the 5 years 1981-84 there were 487 neonatal survivors at gestations of 25-32 weeks; 391 of these developed respiratory failure (oxygen therapy required for more than 6 h). Fifty-six of the latter developed CLD (oxygen therapy required for more than 28 days and a coarse reticular pattern on chest X-ray). These neonates were predominantly of the shortest gestational ages, regardless of the initial chest X-ray diagnosis. Forty-three of these infants with CLD were matched for gestation and initial chest X-ray appearance (respiratory distress syndrome, n = 20; normal, n = 15; non-specific, n = 8) with 42 control infants. The mean duration of oxygen therapy (P less than 0.001), maximum FiO2 (P less than 0.001), incidence (P less than 0.01) and duration of intermittent positive pressure respiration (IPPR; P less than 0.05) and peak IPPR (P less than 0.05) were significantly greater in the CLD group. Mean birthweight (P less than 0.001), arterial cord pH (P less than 0.05) and base excess (P less than 0.05) were significantly lower in the CLD group. Factors that were not statistically significant in the development of CLD included antenatal fetal heart rate abnormality, hypertensive disease of pregnancy, acute intrauterine infection (chorioamnionitis or umbilical vasculitis), administration of antenatal steroids, sex, patent ductus arteriosus and pneumothorax. The association between CLD and ventilator/oxygen therapy is confirmed. Contrary to other reports, male sex, clinical patent ductus arteriosus and pneumothorax were not associated with CLD.

Birth Weight↗
PubMed1987

Effect of povidone-iodine on in vitro locomotion of equine neutrophils.

Incubation of equine neutrophils with povidone-iodine solutions of greater than or equal to 0.2 per cent resulted in total inhibition of migration under agarose. This was caused by the cytotoxic effects of the solutions as shown by pyknosis and cell lysis. Lower concentrations of povidone-iodine, however, did not adversely affect neutrophil viability or locomotion.

Animals↗
PubMed1987

Concentrations of uterine luminal prostaglandins in mares with acute and persistent endometritis.

Intrauterine infusion of 1 per cent oyster glycogen solution was used to induce acute endometritis in four genitally normal mares. Numbers of viable neutrophils recovered in uterine washings had increased by 1 h after infusion and remained elevated for at least 72 h. There was a significant correlation between numbers of viable neutrophils and total protein concentrations and between prostaglandin (PG)F and PGE2 concentrations in washings. There was also a significant relationship between concentrations of 15-keto-13, 14-dihydro PGF2 alpha in plasma and PGF in washings. Intrauterine concentrations of PGF were influenced by cycle stage and in turn the induced acute endometritis interfered with normal ovarian function. Mares with persistent endometritis had significantly higher concentrations of PGF and total protein and percentage of neutrophils and mononuclear cells in washings than normal mares. White blood cells from mares were capable of producing PGF and PGE2 in vitro.

Acute Disease↗
PubMed1987

Effect of ovarian hormones on promotion of bactericidal activity by uterine secretions of ovariectomized mares.

The bactericidal and phagocytic activities of blood neutrophils suspended in uterine washings and the mobilization of neutrophils into the uterine lumen were studied in ovariectomized mares receiving oestradiol benzoate (N = 4), progesterone (N = 4) or oily vehicle (N = 4). Uterine lavage was performed sequentially up to 144 h after induction of endometritis by intrauterine infusion of glycogen (1%). There was no significant difference between the 3 groups in speed of mobilization of neutrophils into the uterus in the first 6 h after infusion but there were significantly more uterine luminal neutrophils in progesterone-treated than in oestradiol-treated mares by 24 h after infusion (P less than 0.01). Uterine washings collected from progesterone-treated mares at 0, 24 and 144 h were significantly worse at promoting bactericidal activity by neutrophils than washings from oestradiol-treated and control mares (P less than 0.001). In oestrogen-treated and control mares bactericidal activity had increased by 144 h but in progesterone-treated mares bactericidal activity remained low. Neither treatment nor time affected the ability of washings to opsonize yeast blastospores. Elevated concentrations of progesterone in plasma were therefore associated with decreased bactericidal activity of neutrophils suspended in uterine washings but the generation of C3b in washings did not appear to be affected by hormone treatment.

Animals↗
PubMed1987

Influence of administration of ovarian steroids on the function of neutrophils isolated from the blood and uterus of ovariectomized mares.

The function of blood and uterine luminal neutrophils from ovariectomized mares treated with ovarian steroids was investigated 18 h after intrauterine infusion of 1 X 10(9) Streptococcus zooepidemicus. Random migration of blood neutrophils under agarose was reduced by treatment with progesterone compared with that of neutrophils from oestradiol-treated and control mares. In-vitro addition of progesterone to blood neutrophils from acyclic ponies also reduced migration. Uterine neutrophils did not migrate under agarose which was probably an effect of bacterial phagocytosis. Hormone treatment had little effect on phagocytosis of yeast blastospores by blood neutrophils. Phagocytosis by uterine neutrophils from oestradiol-treated and control mares was significantly better than that by blood neutrophils. In progesterone-treated mares, however, phagocytosis by uterine neutrophils was significantly lower than that in the other two treatment groups and was similar to that measured in blood neutrophils. The results indicate a marked effect of progesterone in reducing both migration of blood neutrophils and phagocytosis by uterine neutrophils.

Animals↗
PubMed1987

Effect of oestradiol-17 beta on perineal and neck skin glands in heifer calves.

Ten 16-week-old Friesian x Hereford heifer calves were split into experimental and control groups. Experimental animals were given an implant of oestradiol-17 beta in the ear whilst controls were given blank implants. They were killed 14 days later. After implantation the experimental group had consistently greater (P less than 0.01) plasma concentrations of oestradiol-17 beta than the control group. After death, sebaceous gland volume in the perineal region was greater (P less than 0.01) in the experimental than in the control group, whereas sebaceous gland volume in the neck was smaller (P less than 0.01). Sweat gland volume in the perineal region was greater (P less than 0.01) in the experimental than in the control group. There was no difference between groups in the volume of sweat glands in the neck.

Animals↗
PubMed1987

Influence of arachidonic acid metabolites in vitro and in uterine washings on migration of equine neutrophils under agarose.

The influence of arachidonic acid metabolites on migration of equine neutrophils under agarose was investigated. Leukotriene B4 (LTB4) was chemotactic at concentrations between 0.1 and 1000 ng ml-1 and prostaglandin E2 (PGE2) at 1 and 10 ng ml-1 but not at higher or lower concentrations. Prostaglandin F2 alpha (PGF2 alpha) was not chemotactic for equine neutrophils at any concentration. Random migration was significantly inhibited (P less than 0.05) by suspension of neutrophils in LTB4 (0.1 to 1000 ng ml-1) and PGF2 alpha (0.1 ng ml-1) but not at high concentrations. There was a significant positive correlation between random migration of neutrophils suspended in uterine washings from persistently endometritic mares and concentrations of endogenous PGF (P less than 0.002) and PGE2 (P less than 0.05) in washings. Thus certain metabolites of arachidonic acid affect migration of equine neutrophils and may play a significant role in recruitment of neutrophils to sites of inflammation in the horse.

Animals↗
PubMed1984

Clinical and endocrinological investigation of possible ovulatory failure in a dairy cow.

Ovulatory failure was diagnosed in a cow by repeated rectal palpation. The follicle continued to increase in size accompanied by a thickening of the wall and retention of fluid in the central cavity. Plasma hormone profiles showed normal preovulatory oestradiol and luteinising hormone peaks. Four days later progesterone concentrations rose and were maintained for 14 days before falling to baseline concentrations as in a normal luteal phase. Twenty-two days after the luteinising hormone peak, the animal returned to oestrus.

Animals↗
PubMed1982

Monitoring pre-service reproductive status in dairy cows.

Combinations of oestrus detection, ovarian palpation and milk progesterone assays were used to monitor pre-service reproductive status of cows in two dairy herds over two successive years. Non-cyclical cows were identified as having no luteal tissue in their ovaries on two occasions 10 days apart. Absence of luteal tissue was determined by the presence of basal mild progesterone initially followed either by a repeat of this result or by failure to palpate a corpus luteum per rectum. In the period 32 to 56 days post partum the number of non-cyclical cows on farm A years 1 and 2 was eight out of 31 (25 . 5 per cent), and 10 out of 62 (16 . 1 per cent) and on farm B years 1 and 2 was 10 out of 68 (14 . 7 per cent) and 11 out of 85 (12 . 9 per cent) respectively. The farm A herd was high yielding, (average lactation 6380 litres), whereas the farm B herd was of average yield (4717 litres). In both herds 60 day milk yield was not related to cyclical status of pre-service cows. There was however a trend toward a greater proportion of young cows being non-cyclical. With the exception of a prolonged calving to conception interval for farm A in year 1, whether a pre-service cow was cyclical or not had no effect on when the cow was first served or on when the animal conceived. The routine incorporation of pre-service monitoring to herd fertility control programmers may however be of value in recognising the incidence of non-cyclical cows and giving an early indication of oestrus detection efficiency.

Animals↗
PubMed1982

Direct radioimmunoassay of estradiol-17 beta in defatted bovine milk.

A radioimmunoassay was developed for rapid determination of estradiol-17 beta concentrations in unextracted defatted bovine milk. The assay was dependent on the use of a highly specific anti-estradiol-17 beta antiserum. Application of a formula to correct for the interference associated with individual milk samples and use of appropriate assay blanks facilitated interpolation on a buffer standard curve. The assay offered a high degree of sensitivity (0.6pg/ml milk) and a precision (within-assay coefficient of variation: 0.196; between-assay CV:0.191) comparable with contemporary extraction methods.

Animals↗