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Biomedical subjects

D Taylor

Publications and source records attributed to D Taylor.

At least 469 records · Page 26Linked to original sources

A monoclonal antibody to rhesus erythrocyte band 3 inhibits invasion by malaria (Plasmodium knowlesi) merozoites.

Receptors on erythrocytes and malaria parasites mediate specific attachment and junction formation between these cells that lead to invasion of the erythrocytes. We identified monoclonal antibody A9 and its subclone A9D3 that bound to rhesus erythrocytes and blocked invasion of the erythrocytes by Plasmodium knowlesi merozoites. The monoclonal antibodies did not block attachment, the initial step in invasion, although swelling and crenation of the erythrocyte, which normally occur after attachment, were rarely observed in the presence of antibody. The monoclonal antibody immunoprecipitated rhesus erythrocyte band 3. It bound to erythrocytes of another Old World monkey, the kra monkey, but not to erythrocytes of New World monkeys, chimpanzees, or man. Since the antibody did not bind to human erythrocytes, we could test for nonspecific toxicity to the parasite by studying the effect of the ascites and purified antibody on invasion of human erythrocytes. The antibody caused a minimal reduction in invasion of human erythrocytes, a reduction no greater than that seen with an unrelated monoclonal antibody. Further evidence that the inhibition was specific came from study of Fab fragments of A9D3. Column-purified Fab fragments reduced invasion of rhesus erythrocytes without affecting invasion of human erythrocytes. Fab fragments preabsorbed with rhesus erythrocytes did not inhibit invasion. From the above data, we conclude that band 3 is involved in a stage in the invasion process after initial recognition.

Absorption↗

Some observations on hallucination: clinical application of some developments of Melanie Klein's work.

The analysis of a psychotic patient is used to illustrate the importance of certain developments of Melanie Klein's work. The case presentation focuses upon the formal qualities of the patient's communications, many of which were amalgamations of profoundly incompatible elements, particularly a subtle destructiveness which parasitized seemingly impartial reports about her state of mind. These communications embodied important object relationships. The patient used her communications to conjure up psychic disintegration. As a result of her involvement in 'chuntering' her preoccupations would become increasingly violent, cruel and sexualized. The patient's equivocal communications generate confusion. This is central to the patient's experience of self-destruction as persecution. A number of ideas are advanced concerning the origins of the patient's hallucinations. These include her relish at the introduction of sensory distortions. Questions are raised about the nature of certain types of hallucination, the origins and intractability of concrete thinking, about verbalization and about the typology of psychotic patients.

Communication↗

Nuclear magnetic resonance studies of forearm muscle in Duchenne dystrophy.

The forearms of six patients with Duchenne dystrophy were examined by the painless and non-invasive technique of high-resolution nuclear magnetic resonance spectroscopy. The phosphorus spectrum was abnormal in that the ratios of phosphocreatine to adenosine triphosphate and to inorganic phosphate were reduced. Absolute quantification under the conditions of this experiment was not possible but it was probable that in dystrophy the concentration of phosphocreatine in muscle was appreciably reduced. A signal in the phosphodiester region of the spectrum was recorded consistently in patients with dystrophy but not in controls. The intracellular pH of the muscle in the dystrophic patients was abnormally alkaline. The clinical application of nuclear magnetic resonance spectroscopy remains to be proved, but it appears to be a promising non-invasive technique for investigating biochemical abnormalities of muscle disease.

Adenosine Triphosphate↗

Preliminary observations on the metabolic responses to exercise in humans, using 31-phosphorus nuclear magnetic resonance.

The new non-invasive method of 31P nuclear magnetic resonance (NMR) has been applied for the first time to human muscle. The metabolic response to exercise--a fall in intracellular pH, a fall in phosphocreatine content, and an increase in inorganic phosphate (Pi) content--occurs without any change in ATP content of the exercised muscle. Abnormal spectra occur in two myopathies examined to date: in McArdle's syndrome, pH rises during exercise, in contrast to the normal fall; and, in an unusual mitochondrial myopathy, Pi content is high, relative to phosphocreatine content, and in keeping with an excessive oxygen consumption in this patient. Intracellular pH reflected, in addition, the systemic pH of the subject; the anticipated abnormalities in muscle pH have been observed in association with lactic acidosis, renal failure and hyperventilation.

Acidosis, Respiratory↗

Myocardial imaging with dipyridamole: comparison of the sensitivity and specificity of 201Tl versus MUGA.

Myocardial imaging was performed at rest and after dipyridamole infusion using 201Tl and 99Tcm - gated blood pool studies (MUGA). Of 38 patients studied, 21 had coronary artery disease (CAD) and 17 were normal. With 201Tl imaging, 19 of 21 patients with CAD (sensitivity 88%) showed perfusion defects during dipyridamole. Of 17 normals 6 (specificity 65%) showed clear perfusion defects during dipyridamole. With MUGA, 2 of 15 patients with CAD (sensitivity 13%) developed abnormal wall motion during dipyridamole; both patients developed ST depression greater than 1 mm. Of 10 normals none developed abnormal wall motion. Twenty six of 38 patients developed angina during dipyridamole, which was reversed by aminophylline in 24 of 26. We suggest that dipyridamole infusion is effective for 201Tl-perfusion imaging, and easily performed, but is not suitable for MUGA studies where ischaemia is the required endpoint.

Aminophylline↗

Studies on uterine tract infections and the IUCD with special reference to actinomycetes.

Since the advent of the plastic IUCD, an increasing number of patients with clinical pelvic actinomycosis have been reported in the literature and in a very much larger number of women, actinomycetes have been identified in cervical smears, either by Papanicolaou stain or specific immunofluorescence. After a 3-year study, we have concluded that actinomycetes can readily be cultured when the growth of more rapidly growing anaerobes is inhibited by metronidazole and anaerobic culture is continued for up to 14 days. We consider that actinomycetes form part of a polymicrobial anaerobic infestation developing in the presence of a foreign body. The organisms are found almost exclusively in women who have used all-plastic IUCDs for a long term and, from a continuing study, it is apparent that most disappear rapidly when the plastic device is removed or replaced by a copper device. Significant symptomatic evidence of infection is found in a small proportion of patients who are actinomycete-positive.

Actinomycetales↗