Search PubMed⌕ Search

Biomedical subjects

C R Jones

Publications and source records attributed to C R Jones.

At least 127 records · Page 7Linked to original sources
PubMed1985

Myocardial surgical revascularization after streptokinase treatment for acute myocardial infarction.

Eighty-six patients admitted with evolving myocardial infarction within 6 hours of symptom onset were treated with streptokinase. Thirty-nine received intracoronary streptokinase, and 47 received intravenous streptokinase. There were no streptokinase-related complications. Twenty-three patients treated with intracoronary streptokinase and 28 patients receiving intravenous streptokinase underwent coronary artery bypass grafting. On admission, 16 patients receiving intracoronary streptokinase had electrocardiographic evidence of anterolateral evolving myocardial infarction and seven had evidence of inferior evolving myocardial infarction. Time from first symptom to intracoronary streptokinase was 4.4 +/- 1.6 hours. In seven patients, intracoronary streptokinase failed to open the obstructed coronary. All developed severe left ventricular hypokinesia in the area supplied by that coronary artery. In spite of recanalization, nine of 14 patients developed severe hypokinesia in the supplied area, and one an apical aneurysm. Four patients developed mild to moderate hypokinesia, and one had no left ventricular damage. On admission, 14 patients receiving intravenous streptokinase had electrocardiographic evidence of anterolateral evolving myocardial infarction and four had evidence of inferior evolving myocardial infarction. Time from first symptom to intravenous streptokinase was 3.2 +/- 1.5 hours. In seven patients, intravenous streptokinase failed to open the coronary, and all developed severe hypokinesia of the supplied area, with formation of apical left ventricular aneurysm in three. In 21 patients, intravenous streptokinase opened the artery. Eighteen angiographies performed 9.6 +/- 7.9 days after therapy showed a normal left ventricle in eight patients, moderate hypokinesia in seven, and severe hypokinesia in three. Time from first symptom to therapy was shorter in the patients receiving intravenous therapy (p less than 0.01). Coronary artery bypass grafting and four resections after left ventricular aneurysm were performed without operative death. Two patients receiving intracoronary therapy died in the hospital, and one died 2 months later from arrhythmias. Freedom from angina and rehabilitation (New York Heart Association Class I) were achieved in 69.5% of patients receiving intracoronary streptokinase and in 75% of patients receiving intravenous streptokinase. Thus streptokinase-induced thrombolysis salvages myocardium, and the intravenous route seems as effective as the intracoronary. Advantages of the former are earlier administration that might increase myocardial salvage, no invasive procedure, and lesser cost.

Adult↗
PubMed1984

The alpha adrenoceptor antagonist properties of idazoxan in normal subjects.

The imidazoline derivative idazoxan, which has been shown to be a potent, selective alpha 2-adrenoceptor antagonist, was injected intravenously to eight men with normotension. There was a transient small increase in blood pressure and a decrease in heart rate within 20 min of injection, with a slight increase in plasma norepinephrine levels. These effects are consistent with antagonism of prejunctional alpha 2-adrenoceptors. In response to infusions of the relatively selective alpha 2-adrenoceptor agonist alpha-methylnorepinephrine, the pressor dose-response curve shifted to the right with idazoxan. These data provide evidence for receptors with alpha 2-adrenoceptor characteristics on resistance vessels in man. In vitro platelet aggregation studies provide further evidence of selective alpha 2-adrenoceptor antagonism by idazoxan, with greater potency and affinity than alpha-yohimbine. These observations are consistent with both pre- and postjunctional peripheral alpha 2-adrenoceptors in man and provide further support that idazoxan is a selective alpha 2-adrenoceptor antagonist.

Adrenergic alpha-Antagonists↗
PubMed1984

Specific inhibition of aldosterone responses to endogenous and exogenous angiotensin II by somatostatin.

Aldosterone and renin responses to head-up tilt (60 degrees for 1 h) and angiotensin II infusions (2,5 and 10 ng/kg/min) 1 h later were compared in six normal subjects during infusions of somatostatin (3 micrograms/kg/min) or saline. The infusions were performed on separate days two weeks apart. The increase in aldosterone due to exogenous angiotensin II and orthostasis were significantly attenuated by somatostatin. Neither the increase in plasma renin activity (PRA) nor the angiotensin II mediated suppression of PRA were affected by somatostatin. These findings are consistent with the recent observation that somatostatin suppresses aldosterone release in response to angiotensin II in rat adrenal cells in culture and they indicate a possible role for somatostatin in the regulation of aldosterone secretion.

Aldosterone↗
PubMed1984

Urological problems following treatment of carcinoma of the cervix.

One thousand one hundred and sixty-one cases of carcinoma of the cervix presenting over a 20-year period to 1982 were considered: 326 (28%) of these women developed urological problems, of whom 82 (7%) had major complications. Fistula formation occurred in 46 cases (4%), and was associated with active malignant disease in 33. Significant progressive ureteric obstruction occurred in 15 patients, 11 of whom had active malignancy. Overall, 35 (43%) of 82 patients with major urological problems had no evidence of active disease. Urinary diversion by ileal conduit proved to be a relatively simple and effective way of dealing with the serious problems, especially for patients with fistula formation and progressive ureteric obstruction, 67% and 73% of whom, respectively, underwent this procedure. More complex reconstructive surgery proved successful in a small number of selected patients, in whom there was no evidence of active tumour. Attempts to compromise with less definitive or over-ambitious procedures resulted in further complications and prolonged hospitalisation.

Female↗
PubMed1984

Multifocal eosinophilic granuloma: a clinical pathologic conference.

Eosinophilic granuloma has traditionally been designated as the least severe component of the inter-related triad of diseases, Histiocytosis X (Lichtenstein 1953, 1964). In 1969, Lieberman and his group questioned the use of this time-honored term and proposed instead that eosinophilic granuloma be regarded as a separate and distinct entity which could present either as a singular (unifocal) lesion or as a multifocal process. The term, "multifocal eosinophilic granuloma" was, thus, suggested as a replacement for the designation formerly known as Hand-Schuller-Christian Disease. The remaining component of Histiocytosis X termed Letterer-Siwe Disease was felt to be a totally separate disorder unrelated to eosinophilic granuloma and best classified as a relatively aggressive reticuloendothelial malignancy. In this presentation, we wish to report a case of multifocal eosinophilic granuloma which has run a very interesting course over a total of almost 10 years from the time of initial symptoms to the present. The more recent classification of Lieberman will be employed throughout this presentation. We will also propose the hypothesis that in this case, multifocal eosinophilic granuloma may represent a sequela of acquired immune deficiency perhaps initiated by T-cell viral infection. The possibility that, in a susceptible host, development of eosinophilic granuloma may be triggered by contact with environmental agents will also be discussed.

Adult↗
PubMed1983

Semen analysis in testicular cancer and Hodgkin's disease: pre- and post-treatment findings and implications for cryopreservation.

Over a 7-year period, seminal analysis has been performed on 208 patients with testicular tumours, after orchiectomy, but before any other treatment. Only 22% of 54 patients with seminomas, and 29% of 154 patients with teratomas or mixed tumours, had sperm counts exceeding 10 million per ml. Very low sperm counts were observed in some patients who had previously fathered children. Post-treatment sperm counts were done in 117 patients, 80 of whom had received multiple drug chemotherapy: 42 of these men had pre- and post-treatment sperm counts. Overall, 24% of men receiving chemotherapy recovered sperm counts greater than 10 million per ml up to 3 years after therapy. Surprisingly, such recovery was seen in 35% of 23 men with initially poor sperm counts, but in only 26% of 19 with good initial counts. Only 27% of 49 patients with Hodgkin's disease had initial sperm counts of more than 10 million per ml; after chemotherapy only 1 of 29 patients recovered to this level. Only one quarter of these young men had semen which was adequate for cryopreservation. Artificial insemination with semen preserved in liquid nitrogen has been performed in 15 couples: 2 normal babies have been produced and a third pregnancy is progressing normally.

Dysgerminoma↗
PubMed1983

Peripheral pre and postjunctional alpha 2-adrenoceptors in man: studies with RX781094, a selective alpha 2 antagonist.

The imidazoline derivative RX781094 has been shown in animal studies to be a potent selective alpha 2-adrenoceptor antagonist. The alpha 2 antagonist activity of RX781094 was confirmed in this study by in vitro human platelet aggregation studies in which RX781094 was five times more potent than alpha-yohimbine. Within the first 20 min after intravenous administration of RX781094 to eight normotensive men there was a short-lived increase in blood pressure (mean maximum change 9/7 mmHg) and decrease in heart rate (mean maximum change 15 beats/min) associated with slight increases in plasma noradrenaline concentration and renin activity. These findings are consistent with an effect at prejunctional alpha 2-adrenoceptors. The pressor dose-response analysis for three agonists of varying selectivities for alpha 1 and alpha 2-adrenoceptors showed only modest changes with phenylephrine and noradrenaline with dose ratios less than 2, in contrast to the marked antagonism by RX781094 of the pressor response to the alpha 2 agonist, alphamethylnoradrenaline, dose ratio greater than 20. These results provide evidence that adrenoceptors of the alpha 2 subtype are located postjunctionally on resistance vessels in man and that RX781094 is a selective antagonist at human alpha 2-adrenoceptors.

Adrenergic alpha-Antagonists↗
PubMed1981

A system for the continuous collection of 14CO2 from patas monkeys: the metabolism of [14C]cloguanamile.

1. An apparatus is described that allows CO2 expired by monkeys to be trapped and measured and urine and faeces to be separated and collected. 2. When [14C]cloguanamile was administered to rats and to patas monkeys, a marked species difference was seen in the proportion of 14CO2 expired. 3. Suppression of the gut flora by neomycin revealed that this difference was due to enterofloral metabolism.

Animals↗
PubMed1980

Langerhans cell (eosinophilic) granulomatosis.

Eosinophilic granuloma (Langerhans cell granulomatosis) is the only basically nondermatological disorder consistently associated with the Langerhans cell. Its clinical manifestations are protean. There is much circumstantial evidence to suggest that this disease is fundamentally immunologic. This is consistent with current concepts about the Langerhans cell.

Eosinophilic Granuloma↗
PubMed1979

Simplification and spin-spin analysis of the side chain proton magnetic resonance spectrum of the decapeptide gramicidin S using difference scalar decoupling and biosynthesis of specifically deuterated analogs.

Biosynthesis of specifically deuterated molecules and difference scalar decoupling permitted an analysis of all C alpha-C beta spin systems of gramicidin S. Proof is presented that proton magnetic resonance spectra obtained by difference scalar decoupling yield not only spectral assignments and simplification but also accurate chemicals shifts and scalar coupling constants. The variations in (3J alpha beta) and in proton chemical shifts at temperatures over the range of -54 degrees -+66 degrees C are consistent with the internal rotation around the C alpha-C beta bonds of Val1, Orn2, Leu3, and Phe4 residues discovered using carbon 13 spectroscopy. The value (3J alpha beta) = 1.5 Hz for the proline residue is consistent with there being only one C alpha-C beta conformer. This is supported by the small temperature dependence of (3J alpha beta). However, it cannot be rigorously excluded that oscillation between a major and a minor C alpha-C beta conformation occurs for proline.

Amino Acids↗
PubMed1979

Multiple solution conformations and internal rotations of the decapeptide gramicidin S.

The conformations of every C alpha H-C beta H2 moiety of the peptide gramicidin S are reported. Internal rotation occurs, but distinct preferences for one side chain rotamer, greater than 80%, are found for the D-phenylalanine and ornithine residues. Leucine and valine exhibit more extensive averaging while proline is shown to be at least 90% in the Ramachandran B conformation. The data are consistent with the coexistence of many tertiary conformations of gramicidin S; the statistical weights of the twelve major tertiary conformations consistent with the rotamer populations are reported. The relative statistical weights of the tertiary conformers depend upon temperature and solvent. A comparison of the conclusions from this publication and conformations derived by energy minimization procedures is made. Partial agreement was found, but the calculations have not yet predicted the wealth of coexisting tertiary conformations nor accounted for the subtle effects of solvent. It is proposed that a more complete picture of the conformational dynamics of gramicidin S and other peptides will result from calculations which use as a basis the extensive data reported here.

Amino Acids↗
PubMed1979

Determination of plasma concentrations of dapsone, monoacetyl dapsone and pyrimethamine in human subjects dosed with maloprim.

A high-performance liquid chromatographic method was developed to enable dapsone, monoacetyl dapsone and pyrimethamine to be measured simultaneously in plasma samples from volunteers in England and Malaysia who had been dosed with Maloprim. Mean half-lives of 25 and 80 h were calculated for dapsone and pyrimethamine, respectively, but there was wide individual variation. All subjects were found to be classifiable as "slow acetylators".

Adult↗