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Biomedical subjects

W D Smith

Publications and source records attributed to W D Smith.

At least 127 records · Page 7Linked to original sources
PubMed1982

Attempts to immunise sheep against Ostertagia circumcincta with irradiated larvae.

Mature sheep immunised with two doses of 10,000 irradiated Ostertagia circumcincta larvae were only slightly resistant to challenge with a single dose of 10,000 larvae. This slight resistance was abolished if the 'vaccine' worm population was removed one week before challenge. In contrast, seven of eight sheep immunised with irradiated Haemonchus contortus larvae were highly resistant to homologous challenge. Evidence of some cross protection against challenge with O circumcinta was observed in five of six sheep immunised with irradiated H contortus in that egg counts were lower and more worms were retarded as fourth stage larvae.

Animals↗
PubMed1982

Laser light-scattering study of the effect of washing on sperm motility.

The effect of washing on human sperm motility was measured by means of dynamic laser light-scattering spectroscopy. Semen samples from 24 fertile donors were diluted with Biggers, Whitten and Whittingham (BWW) medium and subsequently centrifuged at one of the following forces: 235 x g, 325 x g, 400 x g, 470 x g, 500 x g, 600 x g, and 800 x g. The duration of centrifugation was 8 minutes for the first wash, 6 minutes for the second wash, and 3 minutes for the third wash. Sperm motility was evaluated in terms of the root mean square swimming speed of the spermatozoa and the mean migration rate of washed spermatozoa in estrous bovine cervical mucus (BCM). It was found that sperm motility and viability were improved when semen samples were washed at 235 x g, even after three washes. However, washing at forces of 600 x g or more reduced sperm motility and also their ability to penetrate cervical mucus in vitro. Repeated washing at forces between 300 x g and 500 x g had little deleterious effect on sperm motility.

Cell Separation↗
PubMed1981

Sperm penetration assay: useful test in evaluation of male fertility.

The recently developed sperm penetration assay (SPA) tests the functional capacity of sperm. It is based upon the ability of in vitro capacitated human spermatozoa to penetrate zona-free hamster eggs in vitro. The SPA was superior to seminal fluid analysis in predicting both fertility and infertility; in the prediction of infertility, the difference was highly significant. Data further indicated that fertility in the male may not remain constant with the passage of time. The SPA would appear to have wide application both clinically and experimentally.

Animals↗
PubMed1980

Retirement of anaesthetists. Attitudes in Yorkshire.

The tenure of posts by consultant anaesthetists is compared with that by consultants in other specialties. Populations studied were not strictly comparable: however, due mainly to early retirement for reasons unknown, only 70--80% of anaesthetists who might have been expected to retire at 65 years of age actually did so. Provisional plans for a study of occupational health are described. Results of a questionnaire on attitudes to retirement are reported. Comments elicited refer to: financial and family considerations; a belief in longevity associated with early retirement; effects of ageing upon health, ability and response to 'stress'; lack of self-pacing and of job adjustment for age and health; professional and administrative 'stresses'; recruitment, manpower and workload; health hazards; and a wish to pursue other interests. Forty per cent of responders anticipated retiring before the age of 61 years. Possible relevance of early appointment as consultant is mentioned.

Adult↗
PubMed1980

Low humidity occupational dermatoses.

Two separate instances of dermatoses associated with low humidity in the working environment are reported. In such cases alternative explanations for the dermatoses are often considered and mistakenly adopted.

Adult↗
PubMed1980

The distribution of immunoglobulin in the respiratory tract of sheep.

IgM was the main immunoglobulin seen by immunofluorescence and immunoperoxidase techniques in the nasal and bronchial glands of lambs before suckling. After suckling IgG was found in tissues at all levels of the respiratory tract. Some IgA also was found after suckling but there was little evidence of transport into secretion. In adult sheep IgA -and IgG-containing cells were found in nearly equal numbers in the nasal mucosa but IgA cells exceeded by 2.5:1 in the bronchial mucosa and by 2:1 in the lung. IgA cells usually outnumbered IgM cells by more than 3:1 in all tissues. The numbers of all three classes of immunoglobulin-containing cells increased in sheep with chronic respiratory disease and, although the IgA;IgG ration was reduced, IgA remained the major locally secreted immunoglobulin. Cytoplasmic staining of epithelial cells for IgA and IgM was seen most frequently in proliferating areas which suggested that immature cells were engaged actively in immunoglobulin transport.

Animals↗
PubMed1980

Haemonchus contortus: attempts to immunise lambs with irradiated larvae.

Two doses of irradiated Haemonchus contortus larvae stimulated firm resistance to challenge in adult worm-free sheep but not in two-month-old lambs. Parenteral administration of larval antigens in adjuvant together with the two doses of irradiated larvae did not reduce the susceptibility of the lambs. However four doses of the attenuated larvae stimulated three of six lambs to resist the challenge. Similar concentrations of serum IgG and mucosal IgA and IgG antibodies were detected in the sheep which had been vaccinated with irradiated larvae only, regardless of their immune status. The lambs which had been injected with worm antigens had much higher levels of circulating and mucosal IgG antibodies, but mucosal IgA concentrations were similar to those in the other immunised groups. Histological examination of the abomasal mucosa did not reveal any differences between resistant and susceptible vaccinates.

Animals↗
PubMed1978

A history of nitrous oxide and oxygen anaesthesia. IVC: Henry Hill Hickman in his time.

Previous verdicts on Hickman set the scene. The genealogy of Hickman and his wife is explored, disclosing the identities of "Poor Mrs Dudley of Shut End" and "Thomas Dudley of Kingswinford". Some previous evidence is explained by the bankruptcy of Hickman's father-in-law. The dubious means whereby Hickman qualified prematurely are examined.

Anesthesia, Inhalation↗