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Biomedical subjects

P F Watson

Publications and source records attributed to P F Watson.

At least 127 records · Page 7Linked to original sources
PubMed1981

The roles of lipid and protein in the protection of ram spermatozoa at 5 degrees C by egg-yolk lipoprotein.

Both the low-density lipoprotein fraction of egg yolk (LDF) and sonicated lecithin liposomes provided an equal measure of protection for ram spermatozoa during cold shock, but LDF was superior to lecithin during cold storage. The protective activity of LDF during storage at 5 degrees C was not altered by a subfractionation procedure which did not alter the molecular organization. Removal of the protein from the surface of LDF particles gave preparations with altered lipid:protein ratios. Neither the low-lipid fraction nor bovine plasma albumin protected spermatozoa but the high-lipid fraction was as protective as LDF. Survival of spermatozoa decreased as the lipid:protein ratio fell below 1.67 compared with a ratio of 4.76 for LDF. The absolute lipid content was more important than the ratio except at low ratios. Lipid-depleted preparations bound more effectively to the plasma membrane than did LDF whereas the lipid-enhanced preparation showed little binding capability. It is concluded that the phospholipid of LDF provides the protection to the sperm cell membrane. The protein of LDF serves to solubilize the lipid and bind it to the cell membrane. The importance of the role of the protein during cold storage is discussed.

Animals↗
PubMed1979

An objective method for measuring fluorescence of individual sperm cells labelled with 1-anilinonaphthalene-8-sulphonate (ANS) by means of photomicrography and densitometry.

A method is presented for measuring the degree of fluorescence of sperm cells labelled with 1-anilinonaphthalene-8-sulphonate (ANS). Labelled spermatozoa were subjected to incident-light u.v. illumination and the fluorescent image was photographed. Densitometry of the photographic film yielded values for individual sperm heads, and the mean value for ten cells formed the unit of data for parametric statistical analysis. The method is both objective and precise, and was used to distinguish between treatments applied to the spermatozoa. It is believed that the method has a wide application as an inexpensive means of fluorimetry.

Anilino Naphthalenesulfonates↗
PubMed1976

The effects of age and anaesthetic on the blood picture of the cuis, Galea musteloides.

Blood samples from 25 adult and 6 immature cuis were examined. There were slight differences in red cell parameters (RBC, Hb, PCV, MCV, MCH, & MCHC) between cuis and guinea-pigs. The total white cell count of cuis was much lower. The neutrophils of the cuis, as of the guinea-pig, had eosinophilic granules and were therefore termed pseudoeosinophils. Kurloff bodies were not present in mononuclear cells. There were more platelets in cuis blood compared with guinea-pig blood. The choice of anaesthetic did not influence any of the red cell parameters of the cuis, but may have affected the relative numbers of pseudoeosinophils, the platelet count and the percentage of reticulocytes. Immature animals had a lower erythrocyte count, a higher MCH and fewer platelets than adults.

Age Factors↗
PubMed1975

Use of a Giemsa stain to detect changes in acrosomes of frozen ram spermatozoa.

Acrosomal structures of ram spermatozoa were prominently stained when air dried smears of diluted semen were fixed for 15 minutes in buffered formal saline and stained for 90 minutes in a 6 per cent (v/v) buffered solution of Giemsa stain. Progressive disruption of the acrosomes was demonstrated during chilling and deep-freezing of the spermatozoa, and the degree of damage was systematically scored. A rapid and repeatable estimate of the state of the acrosomes in a sample could be made from the mean score of 20 spermatozoa examined per slide.

Acrosome↗
PubMed1975

The influence of some fractions of egg yolk on the survival of ram spermatozoa at 5 degrees C.

Ram spermatozoa were stored at 5 degrees C in diluents containing various fractions of egg yolk prepared by dialysis, ultrafiltration and ion-exchange chromatography. They survived storage best in the presence of components of egg yolk which were non-dialysable and were not filtered through membranes which retained substances of molecular weight greater than 100 000. The substances isolated in peak B of the ion-exchange chromatogram of whole egg yolk described by Seideman et al. (1969) gave greater protection than those from other fractions from this chromatographic system. These data indicate that the low-density lipoprotein fraction of egg yolk is the most likely source of protection to ram spermatozoa against the effects of storage at 5 degrees C.

Analysis of Variance↗
PubMed1975

Effects of egg yolk, glycerol and the freezing rate on the viability and acrosomal structures of frozen ram spermatozoa.

The influence of egg yolk, glycerol and the freezing rate on the survival of ram spermatozoa and on the structure of their acrosomes after freezing was investigated. Egg yolk was shown to be beneficial not only during chilling but also during freezing; of the levels examined, 1-5% gave the greatest protection. Although the presence of glycerol in the diluent improved the survival of spermatozoa, increasing concentrations produced significant deterioration of the acrosomes. With closely controlled linear cooling rates, no overall difference was detected in the survival of spermatozoa frozen at rates between 6 and 24 degrees C per min. However, a significant interaction between freezing rate and the inclusion of glycerol in the diluent showed that glycerol was less important at the highest freezing rate. A sudden cooling phase near to the freezing point following the release of the latent heat of fusion was not detrimental to spermatozoa.

Acrosome↗
PubMed1975

The interaction of egg yolk and ram spermatozoa studied with a fluorescent probe.

The flourescent membrane marker, 1-anilinoaphtalene-8-sulphonate (ANS) was used to investigate the attachment of egg-yolk to the plasma membranes of ram spermatozoa. The degree of fluorescence was assessed using a subjective scoring system. It was found that egg yolk competes with ANS for sites on the plasma membrane. When the diluent contained 10% egg yolk, no ANS could be detected on the membranes. Egg yolk attached to the plasma membrane could be removed by washing twice with a yolk-free diluent. Loss of sperm motility in the presence of ANS was observed but some spermotozoa remained motile after incubation at 37 degrees C for 15 min with 2mM-ANS. Egg yolk protected spermatozoa against this loss of motility. It is suggested that egg yolk protects spermatozoa during chilling and freezing by its attachment to the sperm plasma membrane.

Anilino Naphthalenesulfonates↗