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Biomedical subjects

F Hughes

Publications and source records attributed to F Hughes.

28 records · Page 2Linked to original sources
PubMed1977

Primary carcinoma of the trachea.

Two cases of primary carcinoma of the trachea are described. Both patients were female and had smoked cigarettes for many years. One of the tumours was a squamous cell carcinoma and the other an oat cell carcinoma, the commonest and the rarest forms of tracheal cancer respectively. The diagnosis in the case of oat cell carcinoma was confirmed by electron-microscopic demonstration of neurosecretory granules, a unique observation at this site. Oat cell carcinoma of the trachea does not appear to have been recorded previously in a female.

Carcinoma, Small Cell↗
PubMed1976

Spin-labeled stearates as probes for microenvironment of murine thymocyte adenylate cyclase-cyclic adenosine 3':5'-monophosphate system.

The interaction of various spin-labeled compounds with the murine thymocyte adenylate cyclase-cyclic AMP system was investigated. Electron paramagnetic resonance spectra from spin-labeled compounds were used to calculate the order parameter, S, and indicated that the thymocyte plasma membrane is a relatively rigid structure. Increasing concentrations of spin-labeled stearates, but not their corresponding methyl esters, resulted in increased membrane fluidity, partial lysis, and concomitant complete inhibition of cholera toxin-mediated increases in cyclic AMP content. Upon subsequent isolation of plasma membranes from these cells, cholera toxin-stimulated adenylate cyclase activity was also completely inhibited. Direct addition of spin-labeled stearates, but not spin-labeled methyl stearates, to thymocyte homogenates caused a dramatic reduction of basal, cholera toxin-, isoproterenol-, NaF-, and prostaglandin E1-stimulated adenylate cyclase activity. Inhibition was complete within the first minute of addition to homogenates and required approximately 0.2 mM spin-labeled stearate I(12,3) for half-maximal inhibition. This inhibition occurred in the presence or absence of an ATP-regenerating system and was not readily reversible. Furthermore, since the membrane cyclic phosphodiesterase activity was not altered by spin-labeled stearates, their inhibition was attributed to a direct action of stearate spin labels on adenylate cyclase. Neither stearate, methyl stearate, spin-labeled methyl stearates nor 2,2,6,6,-tetramethylpiperidine-1-oxyl (Tempo) altered cell viability or enzyme activities at the concentrations studied. Spin-labeled stearates seemed to intercalate into different areas of the plasma membrane than their corresponding methyl esters. Furthermore, the action of spin-labeled stearates appeared to be on the exterior of the plasma membrane rather than the interior. These results illustrate the presence of multilipid domains and the importance of selected lipids and lipid-protein interactions in the adenylate cyclase-cyclic AMP system. Thymocyte adenylate cyclase is described in terms of a current model for membrane proteins.

Adenylyl Cyclases↗
PubMed1976

The synchronization of oestrus and subsequent fertility in ewes following treatment with a synthetic prostaglandin analogue (ONO 453).

ONO 453, a synthetic analogue of prostaglandin F2alpha (PGF2alpha) is a potent luteolytic agent in cycling ewes when given as a single intramuscular injection. The drug was effective in doses of 2 mg when administered after day 3 of the oestrous cycle. It is well tolerated by ewes, producing no apparent signs of toxicity at 5 mg and only a mild transient increase in the respiratory rate at 10 mg. To synchronise oestrus two dosing regimens were examined; a single i.m. dose of 2 mg administered without reference to the day of the oestrous cycle, and 2 injections of 2 mg administered 7 days apart. With the first method 86.6 per cent of the ewes were in oestrus within 24-50 hours of treatment, with the second, 82 per cent were in oestrus within 30-54 hours. To test the fertility of the oestrus following ONO 453-induced luteolysis, both groups of ewes were run with fertile rams and 86 per cent and 70.8 per cent of those induced by the single or double injection respectively, conceived and lambed.

Animals↗
PubMed1975

Paramagnetic spin label interactions with the envelope of a group A arbovirus. Lipid organization.

Electron paramagnetic resonance observations were made on nitroxide spin- labeled molecules which were bound to the TC-83 vaccine strain of Venezuelan equine-encephalomyelitis virus. Paramagnetic resonance parameters derived from the observations and their dependence on sample temperature were similar but not identical to those which have been reported for these labels dissolved in lipid bilayer membranes of mammalian and bacterial origin. The data has a mechanical rigidity substantially greater than that of bilayers in cellular membranes. A model is presented which assumes the location of the lipid bilayer outside the nucleoprotein capsid and inside a spherical layer of envelope proteins. The model is in accord with Harrison's X-ray diffraction results for Sindbis virus. The model is discussed in terms of its implications with respects to the role played by lipid in viral maturation and infectivity.

Animals↗
PubMed1975

Polyarteritis Nodosa "mimicking" eosinophilic gastroenteritis.

This case of a 71-year-old man with persistent eosinophilia (33-54%), intermittent abdominal pain, and transient pulmonary infiltrates illustrates how polyarteritis nodosa may mimic eosinophilic gastroenteritis. The radiographic manifestations and clinical findings of both are similar.

Aged↗
PubMed1970

Cooperative aspects of small ion, small molecule interactions with nucleic aicds. Potassium-polyriboadenylic acid, polyribouridylic acid.

Ionic conductivity measurements vs. temperature were made on KCl solutions of K-polyriboadenylic acid + K-polyribouridylic acid (K-poly-A + K-poly-U) in regions of temperature and composition where the helix-coil transition occurred. It was possible to relate the measurements to a differential helix-to-coil binding of K(+) to nucleotide. The results were, within experimental error, the same as those obtained from a limited number of differential KCl activity coefficient measurements and from a theoretical interpretation of polymer free-boundary electrophoretic mobilities. It was concluded that the alkali ion-phosphate interaction in polynucleotides must be regarded as cooperative in nature and several criteria for recognition of such phenomena were given. A brief outline for a proposed statistical mechanical model for binding was presented.

Adenine Nucleotides↗