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Biomedical subjects

S E Long

Publications and source records attributed to S E Long.

At least 19 recordsLinked to original sources
PubMed2000

Anatomical, cytogenetic and behavioural studies of freemartin ewes.

The external phenotype and reproductive behaviour of 21 freemartin sheep and two male pseudohermaphrodite sheep were recorded with the aim of identifying any characteristics which might be used to predict a failure to breed. The size and shape of the vulva and clitoris, the length of the vagina, the size of the teats, the presence or absence of inguinal gonads, and the ultrasonographic characteristics of the inguinal gonads were recorded. A subjective assessment of the masculinity of each animal's body form was also made, and its behavioural responses to a virile ram and to an oestrus ewe were recorded. A number of physical and behavioural abnormalities were detected but the only consistent finding in all 23 animals was a short vagina which varied in length from 3.1 to 7.0 cm, compared with 10 to 14 cm in normal animals.

Animals↗
PubMed1999

Abattoir survey of acquired reproductive abnormalities in ewes.

Abnormalities of the reproductive tract of female sheep were studied by examining 9970 reproductive tracts from cull ewes and 23,536 tracts from nulliparous sheep (prime lambs) over a period of 12 months in abattoirs in south-west England. Overall, 3.37 per cent of the tracts were pregnant (8.11 per cent of cull ewes, and 1.36 per cent of nulliparous sheep), with a peak incidence between September and December. A total of 655 ewes (6.57 per cent) and 459 nulliparous sheep (1.95 per cent) had acquired abnormalities of the reproductive tract. Within these totals, abnormalities of the ovaries accounted for 3.51 per cent (for the ewes) and 10.68 per cent (for the nulliparous sheep) of all the abnormalities, and abnormalities of the ovarian bursa and uterine tube accounted for 42.1 per cent (for the ewes) and 5.23 per cent (for the nulliparous sheep). In addition, uterine lesions (hydrometra and metritis) accounted for 9.92 per cent (for the ewes) and 13.51 per cent (for the nulliparous sheep); lesions of the cervix and vagina (total of 1.44 per cent) and Cysticercus tenuicollis cysts associated with the reproductive tract (total of 3.05 per cent) were less common. Among the ewes the most common ovarian lesions were ovulation tags, and follicular cysts were the most common in nulliparous animals. Lesions such as bursitis, parametritis and abscesses of the reproductive tract were much more common in cull ewes than in nulliparous sheep, probably having arisen from peripartum infections. Hydrosalpinx and hydrometra, in which the intraluminal fluid was clear, were present at relatively high incidence in nulliparous animals, but not in cull ewes. The proportion of tracts containing macerated fetal remnants (2.14 per cent of all abnormalities in cull ewes) was lower than expected. It was considered that the functional significance of many of the lesions, such as ovulation tags and C tenuicollis cysts, was likely to be low, although in some cases of the latter calcification of the cyst had occluded the uterine tubes. Other lesions, notably hydrosalpinx, bursitis and metritis were likely to have made the affected animals sterile. The acquired abnormalities were therefore more significant in terms of individual animal infertility than as a major cause of infertility in flocks.

Abattoirs↗
PubMed1999

Male tortoiseshell cats in the United Kingdom.

A questionnaire concerning the coat colour and sex of cats being vaccinated or neutered was sent to 2585 veterinary practices; 393 (15.2 per cent) were returned and information was obtained about 9816 cats. Of 4598 males, 20 were recorded as tortoiseshell (0.43 per cent). The frequency of the orange gene was 19.7 per cent assuming that male tortoiseshell cats had two X chromosomes. The chromosome complement and/or gonadal histology of 14 male tortoiseshell cats is described. Cytogenetic analysis of 11 animals revealed six with a 38,XX/38,XY complement, two with 39,XXY, two with 38,XX, and one with a 38,XY complement.

Animals↗
PubMed1999

Standard G-, Q-, and R-banded ideograms of the domestic sheep (Ovis aries): homology with cattle (Bos taurus). Report of the committee for the standardization of the sheep karyotype.

Revised G-, Q- and R-banded karyotypes and ideograms for sheep chromosomes at the 420-band level of resolution are presented. The positions of landmark bands on the sheep chromosomes are defined by their distance relative to the centromere to facilitate comparison with equivalent cattle chromosomes. Chromosome-specific (reference) molecular markers that have been mapped to sheep chromosomes and their equivalent cattle chromosomes are proposed. Reference markers will facilitate genome comparisons between sheep and cattle and minimise confusion due to chromosome nomenclature. Numbering of the Robertsonian translocation chromosomes remains as previously reported.

Animals↗
PubMed1999

Standard G-, Q-, and R-banded ideograms of the domestic sheep (Ovis aries): homology with cattle (Bos taurus). Report of the committee for the standardization of the sheep karyotype.

Revised G-, Q- and R-banded karyotypes and ideograms for sheep chromosomes at the 420-band level of resolution are presented. The positions of landmark bands on the sheep chromosomes are defined by their distance relative to the centromere to facilitate comparison with equivalent cattle chromosomes. Chromosome-specific (reference) molecular markers that have been mapped to sheep chromosomes and their equivalent cattle chromosomes are proposed. Reference markers will facilitate genome comparisons between sheep and cattle and minimise confusion due to chromosome nomenclature. Numbering of the Robertsonian translocation chromosomes remains as previously reported.

Animals↗
PubMed1996

Ovarian fusion in sheep.

A survey of ovine reproductive tracts was undertaken in 2 abattoirs in the south west of England, in which 23,536 tracts from nulliparous animals and 9970 tracts from cull ewes were examined. The ovaries were fused in 15 nulliparous animals. In 13 of these animals, 2 ovarian structures could be separately identified macroscopically, whilst in the 2 other animals, a single structure was seen. On histological examination of the ovaries in which 2 structures could be separately identified, the capsules were confluent and formed a septum between them. In the 2 cases with complete ovarian fusion, a narrow connective tissue septum separating the 2 ovaries was present. No cases of ovarian fusion were found amongst the cull ewes, but prominent strands of fibrous tissue connecting the ovaries were present in 2 animals. It is probable that fusion of the ovaries occurs as a developmental abnormality; evidence from the 2 cull ewes suggests that the ovaries separate once oestrous cyclicity has commenced.

Animals↗
PubMed1994

Rate of discharge and morphology of sweat glands in the perineal, lumbodorsal and scrotal skin of cattle.

The rates of evaporation of moisture from the skin in the lumbodorsal, perineal and scrotal regions of cattle were measured in thermoneutral and high environmental temperatures. The rates of evaporation from the perineal and scrotal regions of heifers and bulls were significantly (P < 0.001) greater than those from the lumbodorsal areas. The lumbodorsal rate of evaporation increased significantly (P < 0.001) when cows and bulls were transferred from a thermoneutral to a hot environment and the rate of evaporation from the scrotum of bulls showed a similar increase; the rate of evaporation from the perineum of cows increased to a smaller extent (P < 0.05) under the same conditions. The rate of evaporation from the perineum of cows reached a maximum on the day of oestrus but the stage of the oestrous cycle had no effect on the lumbodorsal rate of evaporation.

Animals↗
PubMed1994

Clarification of chromosome nomenclature in the sheep (Ovis aries). Report of the committee for the standardization of the sheep karyotype.

In gene mapping, it is obviously essential that gene assignment errors are minimized. Recently, confusion has arisen in sheep gene mapping, as a result of contradictions in chromosome nomenclature. The purpose of this brief communication, prepared by the International Sheep Karyotype Standardization Committee, is to minimize any further confusion that may arise, while new sheep standard Q, G and R karyotypes and ideograms are being prepared. This paper reviews the history of previous sheep karyotype standards, explains the errors that have been detected and presents a correlation table so that, whichever nomenclature is used, the exact chromosome can be identified.

Animals↗
PubMed1994

Fertilizability and structural properties of boar spermatozoa prepared by Percoll gradient centrifugation.

Two techniques for the preparation of boar spermatozoa for in vitro fertilization were studied: a simple washing procedure and centrifugation on a discontinuous Percoll gradient. Their respective effects on motility of spermatozoa were analysed by computer-assisted sperm analysis. The Percoll density gradient technique selected spermatozoa with significantly (P < 0.0001) enhanced motility and movement characteristics. In vitro matured oocytes inseminated with spermatozoa prepared by Percoll gradient centrifugation had significantly (P < 0.0001) greater cleavage rates than did oocytes inseminated with washed spermatozoa. This increased penetration ability was not due to an increased proportion of acrosome-reacted spermatozoa. Transmission electron microscopy revealed no unique ultrastructural differences between the spermatozoa from either preparation. Spermatozoa prepared by Percoll gradient centrifugation are recommended for insemination and studies of porcine in vitro fertilization.

Animals↗
PubMed1993

Folate sensitive common fragile sites in chromosomes of the domestic pig (Sus scrofa).

Chromosomal fragile sites were studied in blood lymphocytes of the pig after induction with 0, 5, 10 and 20 micrograms of fluorodeoxyuridine (FudR) ml-1 of culture. The percentage of cells showing fragile sites and total breaks and gaps in 100 cells was significantly higher in all treated cultures than the control (P < 0.001). A concentration of 5 to 10 micrograms of FudR ml-1 of medium is recommended as the optimum for mitotic index and fragile site expression in the pig. Localisation of the fragile sites was by GTG banding after destaining of the conventionally stained Giemsa preparations. Common fragile sites in the pig were identified in 24 sites on 10 chromosomes. Some fragile sites corresponded to the breakpoints in known reciprocal translocations.

Animals↗
PubMed1992

Reciprocal translocation (13;20)(q12;q22) in an Icelandic sheep.

Cytogenetic examination of G-banded lymphocyte chromosomes of an Icelandic ram from a line with a history of poor fertility revealed a rcp (13;20) (q12;q22) translocation. Meiotic studies showed a quadrivalent configuration at diakinesis and this was confirmed by C-banding.

Animals↗