PubMed Health⌕ Search

Biomedical subjects

A S Todd

Publications and source records attributed to A S Todd.

18 recordsLinked to original sources
PubMed1992

The use of spent renal dialysis membranes for the isolation of large numbers of human neutrophils for biochemical studies. Application to purification of the myeloid IgA receptor (Fc alpha R).

Human neutrophils (PMN) can be eluted from spent Cuprophan renal dialysis membranes in large numbers (10(9)-10(10) per dialyser cartridge) and in relatively high purity by washing the membranes with 0.35 M NaCl. This offers the possibility of isolating relatively large amounts (10(-4)-10(-3) g) of minor PMN proteins such as those expressed on the cell surface. Here the technique is applied to the purification of the neutrophil IgA receptor (Fc alpha R). Affinity chromatography on IgA-Sepharose of NP-40 extracts of 125I-labelled PMN isolated from fresh venous blood routinely gave a receptor preparation showing one diffuse band, Mr 50-70 kDa, upon analysis by SDS-PAGE and autoradiography. When the same method was used with larger numbers of unlabelled PMN from fresh venous blood or renal dialysis membranes a preparation was obtained which gave multiple bands upon analysis by SDS-PAGE silver stained gels due to contamination of the receptor with cytoplasmic proteins which bound non-specifically to the IgA-Sepharose. Most of these contaminants could be removed by chromatography of the IgA-Sepharose eluates on wheat germ agglutinin-Sepharose.

Antigens, CD↗
PubMed1990

Trisomy 21 in transient myeloproliferative disorder.

Transient leukemia in phenotypically normal children is rare. A newborn child in whom fever and tachypnea developed at age 2 days had a white blood cell count of 20.1 x 10(9)/L and many abnormal blast cells. Chromosome analysis of spontaneously dividing cells from the blood showed these to have trisomy 21, and 80% of cells in the marrow were also trisomic. No trisomic cells were present in skin fibroblast cultures. At age 6 months, at which time the blood film appeared normal, trisomic cells were no longer present.

Cells, Cultured↗
PubMed1990

Ear drops and grommets.

The relative ease with which different ear drops pass through grommets of different designs has been investigated using a laboratory model. The viscosities of the various ear drop preparations tested have also been determined. There is a considerable variation in the volume of ear drops required to penetrate ventilation tubes. Their ease of passage is determined by the size of the tube and is probably also related to the ease with which a preparation wets the surface of the grommet. There is no relationship between ease of penetration and viscosity. The penetration of ear drops through grommets during episodes of aural discharge was studied in vivo. Penetration into the middle ear was observed only when the drops were introduced using the displacement technique. It was more readily achieved when the grommet lumen was free of discharge.

Administration, Topical↗
PubMed1988

Use of dark ground microscopy in haematology.

The novel combination of vital staining, quick drying of thin films, and dark ground microscopy furnishes new information about organelles, granules, and precipitates in blood cells. The preparations are permanent and give optical signals of high contrast which depend on refraction or dichroism of the object. Mitochondria are readily shown and can be counted and sized. Pilot observations suggest that mitochondria in red cells may give information about cell maturity and splenic function; that the size of lymphocyte mitochondria may reflect the state of activation of those cells; and that the sensitivity of unstable haemoglobin detection may be greatly enhanced. The method is unsuitable for the study of granulocyte mitochondria.

Animals↗
PubMed1983

Factor VIII-related antigen and procoagulant activity in manic-depressive patients.

Factor VIII-related antigen (VIIIR:AG) and procoagulant activity (VIII:C) were measured at weekly intervals in 11 manic-depressive patients during their hospital stay. There were significant correlations between VIII:C (P less than 0.02), VIIIR:AG (P less than 0.05) and the number of hospital admissions over a 10-year period. The patients' VIIIR:AG showed a wider range of results as compared to a control group (P less than 0.01). The age of onset of the disease (but not the age of the patient) was related to VIIIR:AG (P less than 0.02).

Adult↗
PubMedDate not supplied

Combined intravenous and oral pentoxifylline in the treatment of peripheral vascular disease. A clinical trial.

Sixteen patients with severe occlusive vascular disease of the lower extremities were randomised to receive a five day course of combined intravenous and oral Pentoxifylline followed by three months oral treatment only, or identical treatment with a matching placebo. Nine patients received active Pentoxifylline, and 7 placebo, Follow-up by regular clinical examination and haemoreological assessment revealed a marked improvement in claudication distance and an increase in red cell deformability in those receiving Pentoxifylline, there being no change in those receiving placebo. Although both of the above parameters were improved by the treatment, there did not appear to be a direct correlation between red cell deformability and claudication distance in individual patients. A combination of intravenous and oral Pentoxifylline therapy results in an increase in both claudication distance and red cell deformability, but the former may not te a direct consequence of the latter.

Administration, Oral↗