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Biomedical subjects

J S David

Publications and source records attributed to J S David.

At least 37 records · Page 2Linked to original sources
PubMed1985

Immunohistological studies of the local immune system in the reproductive tract of the mare.

The immunoperoxidase technique was adapted for the identification of free immunoglobulin and immunoglobulin producing cells in equine tissues. Staining specific for free IgG, IgA and IgM was detected at all levels of the reproductive tract, and secretory component staining was present in the uterine epithelium but not in the oviduct, cervix or vagina. Immunoglobulin producing cells were present at all levels of the tract, with IgG and IgA cells at equivalent concentrations, but with fewer IgM cells. There was no cyclical trend in free immunoglobulin staining, or plasma cell numbers. IgG and IgM plasma cell numbers declined from uterus to vagina, as did epithelial staining, and the ratio of IgG:IgA cells declined from oviduct to vagina.

Animals↗
PubMed1985

Specific antibody in the equine genital tract following systemic and local immunization.

An enzyme-linked immunosorbent assay (ELISA) was adapted for the horse to investigate the production of antibody in response to subcutaneous, intrauterine or intravaginal immunization with dinitro-phenylated human serum albumin. An IgM response was not detected, but antibodies of the IgGab, IgGc, IgGT and IgA isotypes were measured in serum, uterine and vaginal secretions. Local immunization produced antibody titres in serum and secretions, with evidence of significant local production.

Animals↗
PubMed1984

Effects of catechol estrogen methyl ethers on lipid metabolism in prepubertal rats.

Thirty-five day old ovariectomised rats were given daily subcutaneous injections (0.05-5.0 micrograms/100 gm body weight) of estradiol (E2) 2-methoxyestradiol (2-ME2) or 4-methoxyestradiol (4-ME2) for six days. At the end of the last injection, the animals were sacrificed and serum lipoproteins were analysed. It was observed that cholesterol decreased significantly in normal fed animals who received E2 and 4-ME2, while no effect was seen in cholesterol fed animals. In the E2 treated group there was a decrease in esterified and free cholesterol, while in the 4-ME2 group only esterified cholesterol decreased. High density lipoproteins were significantly elevated in the E2 treated group. However, there was an increase in very low density lipoproteins and a decrease in low density lipoproteins in 2-ME2 and 4-ME2 treated groups. These results suggest that catechol estrogens may play an important role in the lipoprotein metabolism and atherosclerotic diseases, and the mechanism of action may differ from that of estradiol.

2-Methoxyestradiol↗
PubMed1984

Quantitation of the immunoglobulins in reproductive tract secretions of the mare.

IgG, IgA, IgM and albumin concentrations were measured in serum, follicular fluid and oviductal, uterine and intestinal secretions of the horse. Follicular protein concentrations were found to be dependent on serum concentration and molecular size. Of the immunoglobulins only IgG was detectable in oviductal secretions, but IgG:albumin ratios did not differ significantly from those in serum. IgG, IgA and IgM were measured in uterine secretions, with IgG predominant. Serum transudation into uterine secretions was minimal. In intestinal secretions, IgA levels were slightly higher than IgG, with albumin and IgM at low levels. In five mares with histories of chronic metritis, IgG, IgA and albumin concentrations were significantly elevated in uterine secretions.

Albumins↗
PubMed1979

Impotence in the bull: (2) occlusion of the longitudinal canals of the corpus cavernosum penis.

Lack of penile erection was diagnosed in nine bulls (Poll Hereford three; Aberdeen Angus two; Friesian two; horned Hereford; Sussex). Five had previously served successfully but four had proved impotent when first put to use. In each bull, the dorsal longitudinal canal of the corpus cavernosum penis (ccp) was occluded by fibrous tissue and this was considered to be the immediate cause of impotence. The ventral canals were also occluded in four bulls. In every case, the lesions were so extensive that treatment would not have been likely to succeed. In two bulls the dorsal canal and the tunica albuginea were ruptured proximal to the sigmoid flexure. Radiography of the cavernous spaces and veins during life, and anatomical injections of post mortem specimens, showed that in four bulls the ccp was drained by the dorsal venous system at or distal to the sigmoid flexure. The aetiology and the diagnosis are discussed and the possible physiological implications of occlusions of the canals are considered in terms of the functional anatomy of the ccp.

Animals↗
PubMed1979

Impotence in the bull: (1) Abnormal venous drainage of the corpus cavernosum penis.

Six young bulls (two Friesian, two Charolais, one polled Devon and one North Devon) that had never served successfully, showed good libido but lacked penile erection. In five of these bulls, the short flaccid organ was not protruded during attempted service. Radiography of the cavernous bodies and veins of the penis in the living animal demonstrated major venous drainage of the corpus cavernosum penis (ccp) by the dorsal venous system in all cases. This was not seen in normal bulls. Radiography and anatomical preparations of post mortem specimens showed that the ccp was drained by the dorsal venous system throughout the length of the organ. Proximally, the cavernous spaces of the ccp anastomosed with those of the corpus spongiosum penis (csp) and were drained by numerous small veins. Distally, a system of larger veins, not seen in normal bulls, drained into left and right sides of the dorsal venous system. No microscopical abnormalities of spermatozoa or of testes were found, but there was a marked lack of spermatozoa in the caudae epididymides. The evidence suggests that abnormal venous drainage of the ccp may have been the immediate cause of impotence in these bulls.

Animals↗
PubMed1978

Contagious equine metritis: the present situation reviewed and a revised code of practice for its control.

This report contains details of the code of practice for the control of contagious equine metritis (CEM) during the 1979 breeding season. It was prepared under the guidance of a scientific committee established by the Horserace Betting Levy Board under the chairmanship of Sir David Evans, FRS. The code is similar to the one introduced for the 1978 breeding season but takes into account the experience gained during the past 12 months. Following discussions with colleagues in Ireland it has been agreed that a similar code of practice will be introduced in the United Kingdom and Ireland so as to facilitate a uniform policy for the control of CEM. A summary of this report will be circulated to thoroughbred mare and stallion owners.

Animals↗
PubMed1978

A case of spermatic arteriovenous anastomosis in the horse.

A large anastomosis of the spermatic artery and vein is described. This was found while surgically removing an abdominal testis. Before surgery the animal wanted to rear after exercise and could not stand on 3 legs for any length of time while being shod. This unusual behaviour disappeared after removal of the mass. The performance and conformation of the horse has also greatly improved.

Animals↗
PubMed1978

Lecithin:cholesterol acyltransferase in partial ileal bypass rats.

In cholesterol-fed rats 6 weeks after partial ileal bypass, there was a significant (56%) decrease in serum cholesterol. Also, the concentration of very low density lipoprotein (VLDL) cholesterol was dramatically reduced after operation. However, after the operation, the percentage of high density lipoprotein (HDL) cholesterol was very high, i.e., 45% of the total lipoprotein cholesterol, whereas it was only 25% before operation. The initial rate of lecithin:cholesterol acyltransferase (LCAT), when assayed according to Stokke & Norum, showed an increase from 29 +/- 2 mumole/ml/h for non-operated cholesterol-fed controls to 121 +/- 7 mumole/ml/h after operation (p less than 0.01). After intestinal bypass the extrahepatic triglyceride lipase activity in serum was reduced by 60%, and there was no significant difference in hepatic triglyceride lipase. These observations indicate that in partial ileal bypass, the low serum cholesterol is due to the high HDL cholesterol and the high LCAT activity.

Animals↗
PubMed1977

Histochemistry of cystic ovaries found during an abattoir survey.

Histochemical methods have been used to measure delta5-3beta-hydroxy-steroid dehydrogenase (3beta-HSD) activity in order to establish sites and degree of steroid hormone synthesis in cystic ovaries, corpora lutea and uteri. When granulosa cell layers were present they showed enzymic activity indicating their ability to produce steroids. When both were absent no activity could be seen. Corpora lutea either from ovaries associated with an ovarian cyst or from normally cyclic cows showed varying degrees of activity. When the corpuluteum was immature, activity was low, when mature it was very high and when regressing the activity was declining. No activity was seen in uteri.

3-Hydroxysteroid Dehydrogenases↗
PubMed1977

Histological examination of ovaries and uteri from cows with cystic ovaries.

Sections were cut from 486 cysts taken from 260 pairs of cystic ovaries which had been collected during an abattoir survey. The linine of the cysts was examined for the presence of granulosa, basement membrane, theca and luteinisation. Sections of the uteri were examined and the nature of the surface epithelium, the thickness of the endometrium and the activity of the uterine glands were recorded. In those cysts associated with a corpus luteum both granulosa and luteinisation were seen less often than in other cysts. Of the 486 cysts examined 111 (22-84 per cent) had luteinisation, the others had none. Luteinisation was most often encountered when granulosa was absent. The thickness of theca was greater in cysts than in normal follicles and was thickest in thick walled cysts associated with a corpus luteum. The majority of uteri (81-9 per cent) were normal and only in 4-78 per cent was "swiss chese" dilation of the glands seen. Thirteen cases of mucometra were seen and these are discussed in detail.

Animals↗
PubMed1977

Anatomical features of cystic ovaries in cattle found during an abattoir survey.

During an abattoir survey, 8071 bovine genitalia were examined. Cysts of 2-5 cm or larger were found on one or both ovaries in 307, an incidence of 38 per cent. The cysts were arbitrarily classified anatomically into eight groups according to the number present and their texture, whether thin or thick walled, and to the presence or absence of a corpus luteum. The weight and dimensions of the cysts were recorded and any abnormalities of the genital tracts were noted. Ninety-six specimens (30-67 per cent) were associated with a corpus luteum and 217 (69-33 per cent) had no corpus luteum. One hundred and sixty eight tracts (53-67 per cent) had single cysts and in 145 (46-33 per cent) they were multiple. The incidence of multiple ovulations was higher in the cystic ovaries which had corpora lutea than in the non-cystic population. The incidence of ovaro-bursal adhesions in the cystic population was three times higher than in that found in the genitalia which had no cysts and it is possible that this resulted from trauma during rectal palpation.

Animals↗
PubMed1977

The incidence of ovarian activity, pregnancy and bovine genital abnormalities shown by an abattoir survey.

All female genital tracts removed during the slaughtering process in a West Country abattoir were collected on two days a week from February 1974 to May 1974 inclusive and thereafter collections were made on one day each week from June 1974 until September 1975 inclusive. A total of 8071 tracts was examined; 1885 (23-36 per cent) of these were pregnant. The stage of pregnancy and the number and location of the fetuses is recorded. Cyclic activity in the non-pregnant tracts was assessed by the presence of a current corpus luteum on one or both ovaries and the number and location of these are reported. Any macroscopic abnormalities of ovaries, Fallopian tubes and uteri were recorded, 804 (9-96 per cent) of the tracts were affected. The most commonly encountered abnormality was cystic ovaries and 307 (3-80 per cent) of the genitalia showed this condition.

Abattoirs↗