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Biomedical subjects

M J Harvey

Publications and source records attributed to M J Harvey.

At least 19 recordsLinked to original sources

Measurement of plasma oestradiol after an injection of a gonadotrophin as a test for neutered bitches.

Twenty-eight bitches with unknown reproductive histories were injected intravenously with either human chorionic gonadotrophin (hCG) or equine chorionic gonadotrophin (eCG) (pregnant mare's serum gonadotrophin) and their oestradiol responses were measured at the time of the injection and 90 minutes later. They were at various stages of the oestrous cycle as determined by histology and a progesterone assay for luteal function. Twenty-six of them were considered to be entire because they showed either an increase in plasma oestradiol over preinjection values or steady high values. The ovaries were removed from 25 of these animals and the other probably had a remnant of ovary because it came into oestrus some weeks later. In two remaining bitches no oestradiol could be detected either before or after the injection of gonadotrophin and they were predicted to have been neutered, which was confirmed at laparotomy. In the entire bitches, the highest plasma oestradiol concentration was measured during metoestrus and the lowest during anoestrus.

Animals↗

A study of the aetiology of pseudopregnancy in the bitch and the effect of cabergoline therapy.

Thirty-two permanently pseudopregnant bitches were treated with the anti-prolactin drug cabergoline. They had all been ovariohysterectomised up to five months after their last season, in some cases over two years previously, when most were reported as showing no signs of the condition. The clinical signs were mainly behavioural, the majority being aggressive, and a small number were lactating. The efficiency of the cabergoline therapy was classified by the owners as 'excellent' or 'good' in 50 per cent of the cases, and fair in 36 per cent. The rate of success was markedly better than in similar cases treated with reproductive steroids. In all but one of the bitches, the plasma prolactin concentrations were basal.

Aggression↗

Effect and mechanisms of the anti-prolactin drug cabergoline on pseudopregnancy in the bitch.

A potent anti-prolactin drug, cabergoline, administered orally for five days, was clinically successful in treating three different clinical manifestations of pseudopregnancy in referred bitches. The clinical conditions treated were categorised as standard pseudopregnant bitches (n = 8), those previously unsuccessfully treated with hormones (n = 10) and those which had behavioural pseudopregnancy following ovariohysterectomy (n = 8). The number of bitches whose owners reported a 'good' response was seven out of eight, six out of 10 and six out of eight, respectively. There were very few side effects in that only one bitch vomited following treatment. The clinical response did not necessarily appear to be related to an alteration in circulating prolactin concentrations, suggesting that the drug may have a direct effect on the tissues as well as in most cases reducing the plasma prolactin concentrations.

Animals↗

Effects of castration on luteinizing hormone secretion and response to gonadotrophin-releasing hormone in sheep infected with Trypanosoma congolense.

The effects of trypanosomiasis on the endocrine function of the hypothalamo-pituitary-gonadal axis were investigated before and after castration of Scottish Blackface rams infected with Trypanosoma congolense and uninfected controls. Blood samples were collected at 15-min intervals for 6 h before and at 10, 20, 40, 60, 80, 100 and 120 min after injection of synthetic gonadotrophin-releasing hormone (GnRH, 20 micrograms iv) 2 days before infection and 26 and 54 days after infection, with castration being performed 28 days after infection. Mean luteinizing hormone (LH) pulse amplitude was higher (3.3 +/- 0.2 vs 2.6 +/- 0.3 ng/ml) and mean plasma testosterone concentration was lower (4.1 +/- 0.6 vs 7.6 +/- 1.2 nmol/l) in infected vs control rams 26 days after infection (p < 0.05). Mean plasma LH concentration and pulse amplitude increased in both groups after castration but both were significantly lower in infected compared to control rams (6.6 +/- 1.5 and 13.0 +/- 2.2 ng/ml, p < 0.01; 7.7 +/- 0.9 and 11.6 +/- 0.9 ng/ml, p < 0.001), respectively. However, LH responses to exogenous GnRH were similar in infected and control rams at each stage of the experiment, suggesting that the smaller increase in plasma LH after castration in infected rams was not caused by reduced responsiveness of the pituitary to GnRH but by alterations in GnRH secretion by the hypothalamus or its transport to the adenohypophysis. These results also demonstrate that impairment of testosterone secretion within 4 weeks of T. congolense infection in sheep may be due to testicular rather than pituitary effects.

Animals↗

Vaginal cysts causing tenesmus in a bitch.

An eight-year-old female border collie was referred with a two-month history of faecal tenesmus. Ultrasonography and radiology identified fluid-filled masses in the cranial vagina. The fluid was drained from the vaginal cysts via an episiotomy and the clinical signs resolved. Histological examination confirmed that the cysts were of urogenital origin. This is believed to be the first report of vaginal cysts causing faecal tenesmus in the dog.

Animals↗

Termination of early pregnancy in sheep with dinoprost or cloprostenol: comparison of two commercial preparations.

The response of the ovine corpus luteum of pregnancy to the luteolytic effect of prostaglandin F2 alpha (dinoprost) and its analogue, cloprostenol, was tested in both superovulated and untreated ewes by monitoring plasma progesterone concentrations at the time of 'material recognition' and beyond (days 13 to 30). On days 13, 16 and 28, the majority of the superovulated ewes were refractory to 10 mg of dinoprost. The luteolytic efficacy of 250 micrograms of cloprostenol was compared with 10 mg of dinoprost on day 20 of pregnancy in superovulated and untreated animals and the two prostaglandins were also compared on days 26 and 30 in animals previously unresponsive to dinoprost. Generally, cloprostenol was more effective than dinoprost because there was less refractoriness on day 20 and no refractoriness on days 26 and 30 to this prostaglandin. No difference in the sensitivity to this drug was found between the superovulated and untreated groups on days 20 and 26.

Abortion, Induced↗

Problems associated with ultrasonography of the canine ovary around the time of ovulation.

Real-time B-mode ultrasound imaging was carried out, using a scanner of moderate quality, on 40 fresh bitch cadavers to identify the presence of ovaries and significant ovarian structures. The results indicated that accurate identification of the ovaries depended on the presence of significant follicles or corpora lutea (CL). The findings were verified at post-mortem examination. The study was continued by scanning 35 live bitches using three different scanning units of increasingly improved quality to show that the process of ovulation could be assessed with reasonable accuracy with improved quality of equipment, although the exact fate of the follicle could not be imaged. The results were judged against assays for blood circulating progesterone. A final group of seven live bitches were scanned with a high-grade scanner using an annular phased-array transducer to attempt to image the process of ovulation. The non-echogenic follicle disappeared and was replaced by the CL that was hypoechoic with respect to surrounding tissue, thus allowing accurate assessment of the time of ovulation. This was confirmed by progesterone assay.

Animals↗

Acute phase proteins in canine pregnancy (Canis familiaris).

An acute phase response has been identified during mid-gestation in bitches by determination of the serum C-reactive protein (CRP) concentration. In four pregnant bitches, a large increase in CRP during mid-gestation was followed by a second increase after parturition. In three pregnant bitches, a similar increase was observed during mid-gestation but the second (post parturition) increase was not detected. In two pregnant bitches only a small rise was observed in mid-gestation. No increase in CRP was observed in the serum of two bitches that were not mated following oestrus or in the serum of two bitches that were mated but did not become pregnant. One bitch was diagnosed as pregnant by palpation but did not produce a litter and did not have a mid-gestation increase in CRP. However, this animal did show an acute phase response shortly after oestrus.

Animals↗

Molecular biological methods for monitoring oocyte maturation and in vitro fertilization in bitches.

Oocytes were collected from ovaries of bitches, at various stages of the oestrous cycle, after routine sterilization. Cumulus-enclosed oocytes were cultured for 0-72 h in a modified M-199 medium containing 10% oestrous bitch serum and 20 micrograms oestradiol ml-1. For oocytes surrounded by two or more layers of cumulus cells, an increase in the expression of mRNA transcripts for zona pellucida glycoprotein 3 (ZP3) was seen and reached peak levels after 48 h culture in vitro. Histological assessment showed that 39% of these oocytes had extruded their first polar body after 24 h culture in vitro. When these in vitro matured oocytes were transferred to oviduct cell monolayers and inseminated with fresh dog spermatozoa in Medium-199 supplemented with 10% fetal calf serum and 50 mg gentamicin sulfate ml-1, penetration of the zona pellucida started 1 h after insemination for oocytes that had been cultured for 48 and 72 h. At 12 h after insemination both male and female pronuclei were seen in 37.5% and 20% of the oocytes incubated for 48 and 72 h, respectively. No further development was seen.

Animals↗

Observations on the treatment and diagnosis of open pyometra in the bitch (Canis familiaris).

Eight bitches presenting with vaginal discharges were diagnosed as having open pyometra, as assessed by ultrasonographic, radiographic, haematological and clinical investigation. Plasma progesterone was assessed before treatment with prostaglandin F2 alpha (Dinoprost) and three of the bitches had low concentrations. Each bitch was given multiple injections of PGF2 alpha and monitored during and after treatment. All bitches had basal progesterone concentrations after treatment and the uterine diameters were markedly reduced by that time. One bitch has subsequently produced a litter of seven pups. Five of six bitches that were subjected to ovariohysterectomy 1-2 months later had normal uteri, although one had caseated areas in the uterine wall.

Animals↗

Comparison of endocrine changes and ultrasound as means of identifying ovulation in the bitch.

Twenty bitches were monitored through pro-oestrus and oestrus using both circulating plasma hormone levels and ultrasonic examination of the ovaries. Using luteinising hormone (LH) as being the generally accepted optimum indicator of the day of ovulation, comparisons were made of the accuracy of progesterone and ultrasound to identify ovulation. Progesterone agreed with LH in 12 of 20 bitches and was within one day in seven of the other eight. Ultrasound was less accurate in that only four of the 16 estimates agreed, with a further six being within one day. However, if only the bitches which were examined by ultrasound with the latest equipment were included, while only three of 11 coincided, six of the remaining eight were within one day of the LH estimated ovulation. It is concluded that, at present, of the rapid assessments, the measurement of plasma progesterone is a better estimator of ovulation than ultrasound.

Animals↗

Rapid isolation of human CD34 hematopoietic stem cells--purging of human tumor cells.

Human CD34+ hematopoietic stem cells were purified using a new technology in which monoclonal antibodies are covalently immobilized on polystyrene surfaces. The CD34+ cell isolation scheme involved three sequential processes: (1) purification of bone marrow mononuclear cells; (2) enrichment of CD34+ cells using covalently immobilized soybean agglutinin; and (3) positive selection of CD34+ cells using polystyrene surfaces coated with the anti-CD34 monoclonal antibody ICH3. CD34+ cells purified by this process have both low-to-medium forward light scatter and low 90 degrees light-scatter properties. Moreover, the purified CD34+ cells are greater than 85% viable, express appropriate characteristic surface antigens, and are 10-50-fold enriched in short- and long-term hematopoietic activity. CD34+ cells collected in this manner from bone marrow samples contaminated with radiolabeled breast carcinoma, neuroblastoma, acute myelogenous leukemia, or small cell lung carcinoma cells were 99.9% depleted of the tumor cells. The CD34+ cell selection devices are sterile and are easily scaled-up to process clinical scale bone marrow samples.

Antibodies, Monoclonal↗

Ovulation, fertilization and early embryonic development in the bitch (Canis familiaris).

Using circulating plasma hormone estimations, ovulation was monitored in bitches. The results obtained indicate that the timing of ovulation bears little relationship to alterations in sexual behaviour. The bitches were killed and reproductive tracts were removed at various intervals after ovulation and ova or embryos were recovered. The embryo stages were assessed visually and some were investigated histologically. Embryonic development, to early blastocyst stage, took place within the oviducts during the first 12 days after ovulation and there was a marked increase in size between the early and late blastocyst. A culture system using cells from the uterine tube supported the development of one 1-cell embryo to the morula stage.

Animals↗

The use of a bovine plasma progesterone ELISA kit to measure progesterone in equine, ovine and canine plasmas.

A commerical kit designed to measure the concentration of progesterone in bovine plasma using an enzyme-linked immunosorbent assay (ELISA) has been assessed for measuring progesterone in the plasma of horses, sheep and dogs. Without validation, an immunoassay developed for progesterone in one species should not be used to measure progesterone in the plasma of other species. The kit was assessed by using the criteria of parallelism to a standard curve, the recovery of added progesterone, the correlation with an established radioimmunoassay and the detection of physiological change for each of the species tested. The ELISA kit proved to be acceptable for the analysis of progesterone in the plasma of each species, and in particular for the detection of the low concentrations found during the follicular phase and of the subsequent rise during the luteal phase of the oestrous cycle.

Animals↗