Biomedical subjects
S W Ricketts
Publications and source records attributed to S W Ricketts.
The placenta as a determinant of fetal well-being in normal and abnormal equine pregnancies.
One hundred twenty-four horse placentas were evaluated according to gross appearance, weight and surface area. Grossly abnormal placentas were photographed, and histological sections were taken from abnormal appearing areas, and from representative areas (pregnant horn, non-pregnant horn, body and cervical pole) in both normal and abnormal placentas. Information about the resulting foals was obtained and correlations examined. Histological sections were reviewed and related to the resulting foals. Four normal fresh placentas were infused with dyes to ascertain the blood supply to various areas. Foal weight was statistically related to both allantochorionic surface area and allantochorionic weight. When normal placental surface area was divided by foal weight and related to gestational age, a statistical (P less than 0.0001 and r = 0.829) relationship emerged. Long cords were seen frequently with fetal demise. Histological abnormalities in the placenta were highly associated with fetal demise or fetal abnormalities, with only 2 normal Thoroughbred foals resulted from the 23 placentas exhibiting abnormal histology. Among the ponies, the same relationship held, with 3 normal ponies delivered from 9 abnormal placentas. Normal placentas were associated with normal offspring in most cases. Perfusion studies indicated that, in the four placentas studied, one umbilical artery supplied the cervical area and the non-pregnant horn, whereas the other supplied the pregnant horn. The body had a mixed supply from both arteries. This study evaluated the feto-placental unit in terms of normal and abnormal measurements and histology related to foal outcome. The presence of abnormal histological appearance of the placenta appeared to be more closely associated with foal abnormality than the percentage of placental area involved in the abnormal process. More information is needed before placental blood supply can be related to abnormal processes.
The irritancy of chlorhexidine gluconate in the genital tract of the mare.
Uterine irrigation was carried out in eight Welsh pony mares using 50 ml of chlorhexidine gluconate solution diluted to give active ingredient concentrations of 0.25 per cent to 2 per cent. Treatment was repeated up to twice in mares showing no adverse effects and irritancy of treatment judged on clinical symptoms and uterine biopsy. Results indicated the inadvisability of using a higher concentration than 0.25 per cent. Three daily applications of a diluted surgical scub solution containing 2 per cent chlorhexidine gluconate to the penis of an arab stallion failed to produce symptoms or irritation. An in vitro minimum inhibitory concentration test performed with the contagious equine metritis organism confirmed its high sensitivity to both chlorhexidine gluconate preparations.
Scanning electron microscope studies of the endometrium of the cyclic mare.
Endometrial biopsies obtained from mares at different stages of the oestrous cycle, during anoestrus and in various abnormal conditions were examined with the scanning electron microscope. Preliminary observations suggest that the patterns of secretory and ciliary activity in the uterine epithelium are similar to those observed by electron microscopical techniques in laboratory and other large domestic animals. The response of the epithelial cells to hormonal variations and infections is compared with that of the endometrium as seen with the light microscope.
Endometrial biopsy findings in mares with contagious equine metritis.
Endometrial biopsy samples before and after treatment were obtained from 10 mares naturally infected and one Pony mare experimentally infected with Contagious Equine Metritis in 1977. The histopathological features were a short-lived polymorphonuclear cell infiltration of the luminal epithelium and stroma followed by a very early and marked mononuclear cell infiltration of the stroma, including many plasma cells. The luminal epithelium responded with cellular proliferation which may have reflected a regenerative response. Following the initial acute response, intercellular basal vacuoles containing amorphous and granular material and degenerate leucocytes, were seen in association with the basement membrane for several weeks following infection and apparent recovery. Specimens taken from 9 mares after treatment suggested a varied response. Endometrial biopsy was useful in demonstrating an endometrial response to infection in individual mares prior to the isolation of the causal organism. Its usefullness as a screening test was limited by the ability of mares to harbour the organism in the lower genital tract whilst showing little or no evidence of acute endometritis.
Ultrastructural studies of the equine uterus and placenta following parturition.
Post-partum placentae and uterine biopsy samples from mares after normal and abnormal foalings are described. After normal delivery there is little damage to fetal or maternal tissues. The villous epitheliochorial palcenta separates cleanly at the maternal-fetal interface and the afterbirth consists almost exclusively of fetal tissue. Uterine involution is well advanced by the 3rd and 4th days post partum and the changes are usually complete by the oestrus 7--10 days after parturition. Placental separation and involution of the uterus appear to proceed normally in malpresented foals and in otherwise viable foals with musculoskeletal defects. In aborted, stillborn or dysmature foals there are obvious signs of damage to both fetal and maternal tissues. It is generally accepted that the growth and development of the fetus is dependent upon a placenta of adequate functional capabilities. The observations suggest that the placenta is similarly dependent upon its association with a normal healthy fetus.
Endometrial biopsy studies of mares with contagious equine metritis 1977.
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Klebsiella aerogenes in mares.
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A case of peritoneal mesothelioma in a thoroughbred mare.
The report describes a case of abdominal neoplasia in a mare diagnosed ante-mortem by the technique of paracentesis abdominis. Histopathological findings suggest that the lesion was a mesothelioma, primarily involving the greater omentum.
The equine practice laboratory.
The authors discuss the value of a practice laboratory to the equine clinician and its priorities. Laboratory examinations of particular value are described in relation to their clinical application. The need to establish normal values according to laboratory and horse population is stressed. Tables of normal parameters related to age groups of horses in the authors' practice are presented.
A case of equine infectious anaemia in Newmarket.
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The technique and clinical appication of endometrial biopsy in the mare.
The author describes a technique for obtaining endometrail biopsy specimens from mares. the noraml cyclincal histology of the endometrium and anarbitarry classification histology of the endometrium and an arbitarary classification of the histopathology seen in endometrial biopsy speciemens. Previous literature on the subject is cited. Results of endometrial biopsies taken by the author from 134 barren mares, with histories of subfertility are descirbed and classified. The use of the technique and the interpretationof its find ings in relation to reproductive performance is discussed.
Endometrial biopsy as a guide to diagnosis of endometrial pathology in the mare.
A safe and simple technique of endometrial biopsy is described which the results suggest is a useful adjunct to the diagnosis of suspected pathological conditions of the uterus. In conjunction with other clinical data and a knowledge of the breeding history, histopathological findings form a basis for prognosis and treatment of the subfertile mare. A system of classification is presented as a basis for continuing work on the correlation of endometrial histopathology with fertility and breeding potential.
Chromosome abnormalities as a cause of infertility in mares.
Chromosomal abnormalities have been detected in seven mares isolated by their poor reproductive performance. All had small or rudimentary gonads and absent or irregular oestrous cycles. Two mares had an XO genotype, one was a 65,XXX female and another a 64,XY sex-reversed female. Two other mares were sex chromosome mosaics of the 63,X/64,XX type. The seventh mare showed a normal female karyotype but a small extra autosomal fragment was found in a few cells.