Biomedical subjects

A J Phillips

Publications and source records attributed to A J Phillips.

At least 55 records · Page 3Linked to original sources

PubMed1987

A comparative investigation of glycinebetaine and dimethylsulphoxide as liposome cryoprotectants.

The release of streptomycin from lecithin liposomes following a freeze-thaw cycle was used to measure the cryoprotective activities of glycinebetaine and dimethylsulphoxide (DMSO). At concentrations between 4 and 8% w/v in the external solution, glycinebetaine was superior to DMSO at freezing rates faster than 50 degrees C min-1. At lower rates their activities were similar, and drug loss ranged between 10 and 20% depending upon freezing rate and cryoprotectant concentration. The pattern of streptomycin loss when the concentrations of cryoprotectants inside and outside the liposome were varied indicated that glycinebetaine, in contrast to DMSO, does not diffuse across the liposome membrane. The activity of glycinebetaine was not impaired by the presence in the membrane of cholesterol or charged lipids.

Betaine↗

PubMed1986

Acute salpingitis subsequent to tubal ligation.

Acute salpingitis subsequent to tubal ligation is an uncommon event. Multiple studies have given credence to the assumption that salpingitis after tubal ligation does not occur. Four cases of salpingitis after tubal ligation are reported during the period of January 1980 to May 1985. This relates to an incidence of one in approximately 450 cases of acute salpingitis. A case of acute stump salpingitis with sequela from tubal rupture is reported and represents (to the authors' knowledge) the third reported case in the literature. Salpingitis can occur in the proximal stumps of tubes that have been ligated.

Acute Disease↗

PubMed1986

Factors influencing cryoprotective activity and drug leakage from liposomes after freezing.

The effects of freezing and thawing conditions and cryoprotective additives on release of streptomycin from lecithin liposomes following freeze-thaw cycles have been investigated. Drug retention was maximized by slow cooling (approx. 1 degree C min-1). At temperatures between 0 degree and -20 degrees C, the extent of drug loss was time-dependent indicating incomplete freezing; below -45 degrees C this effect was abolished and the system was stable. Osmotic gradients across the liposome membrane during freezing were found to have little effect on drug loss. Marked cryoprotective activity was shown by dimethylsulphoxide, glycerol, alanine and glycinebetaine at concentrations of 3% w/v or less. At this concentration sucrose and mannitol had little activity.

Cryoprotective Agents↗

PubMed1986

An evaluation of five serological tests for the detection of antibody to bovine herpesvirus 1 in vaccinated and experimentally infected cattle.

More than 300 bovine sera from a previously reported vaccination and challenge trial were tested for antibodies to bovine herpesvirus 1 (BHV1) by five serological assays: enzyme-linked immunosorbent assay (ELISA) for IgM and IgG, passive haemagglutination (PHA), and two methods of virus neutralisation (VN). In a statistical comparison of ELISA (IgG), PHA and VN results, the assays showed highly significant correlations (P less than 0.01). The sensitivities of ELISA and 24-hour neutralisation tests were similar, in contrast to passive haemagglutination and one hour neutralisation which failed to detect BHV1 antibodies in some low titre sera.

Animals↗

PubMed1982

The effect of oils on the lymphatic absorption of DDT.

Plasma concentrations of DDT were measured in conscious rats following oral administration in arachis oil, Miglyol 812 (fractionated coconut oil), liquid paraffin or as a fine suspension in water. The total absorption of DDT, calculated as the area under the plasma concentration time curve, was significantly greater for the arachis oil formulation compared to the other vehicles. In anaesthetized rats it was shown that DDT absorption was almost totally via the lymphatic system, and that lymph levels of DDT were highest following administration in arachis oil. Measurement of lymph flow showed that this enhanced absorption of DDT in the presence of arachis oil was not due to an increased flow as both arachis oil and liquid paraffin stimulated lymph production to the same extent.

Absorption↗

PubMed1974