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W Martin

Publications and source records attributed to W Martin.

349 records · Page 20Linked to original sources
PubMedDate not supplied

The potential impact of patient self-referral on mortality in acute myocardial infarction.

Audit is now an important component of the provision of acute cardiology services. In particular, the desire to administer thrombolytic treatment early in acute myocardial infarction has led to a reappraisal of admission procedures. Using records collected prospectively onto a computerized coronary care database for 36 months to December 1991, median delay before arrival at the emergency department and delay between admission and thrombolytic treatment was calculated. Of 1993 consecutive admissions to the coronary care unit, 816 patients had an initial diagnosis of myocardial infarction (later confirmed in 89.6 per cent), and 608 (74.5 per cent) of these received thrombolytic treatment. Overall median delay before arrival at hospital was 147 min. Randomization during the ISIS-3 trial significantly prolonged delays after arrival at hospital (64 vs. 50 min; p < 0.007). General practitioner referral delayed arrival at the emergency department (175 vs. 100 min self-referred; p < 0.0001) and was associated with similar hospital delay (54 vs. 55 min self-referred). Older patients ( > 65 years) presented later in the self-referred group (120 vs. 99 min for age < 65 years; p < 0.04), but there was no difference in the GP-referred group. Previous ischaemic heart disease did not predict type of referral. If delays before thrombolytic treatment are to be reduced significantly patients should be encouraged to seek early medical assistance by telephoning for an ambulance. Delays for patients arriving at the hospital following referral by a GP should be reduced by facilities for direct admission to the cardiologist.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMedDate not supplied

Development of the AT&T Health Audit for measuring organizational health.

Like any behavioral intervention, health promotion programs require a thorough initial assessment of an array of individual and organizational problems, needs, interests, and resources. Accurate risk assessment should include both contextual and personal characteristics as well as the interaction between the two. This article describes the AT&T Health Audit, a survey that addresses worksite health issues and collects data on the prevalence of lifestyle risk factors, as well as the attitudes, knowledge, and skills related to health. A copy of the Health Audit is provided and its applications are discussed.

Health Promotion↗
PubMedDate not supplied

Induction of nitric oxide synthase by endotoxin in rat isolated aorta but not in rat aortic smooth muscle cells grown in culture from explant.

Incubation of endothelium-denuded rings of rat aorta at 37 degrees C for 18 hours in Krebs solution led to a profound depression of the contractile actions of phenylephrine (1 nM-10 mu M). A major component of this depression of vasoconstriction was due to the relaxant actions of nitric oxide since it was reversed following inhibition of the synthesis of nitric oxide with N(G)-nitro-L-arginine methyl ester or its actions with haemoglobin (30 microM) or methylene blue (10 mu M). The depression was also reversed upon treatment with LY83583 (0.1-1 microM which generates superoxide anions, intracellularly and extracellularly, but was unaffected by hypoxanthine (100 microM)/ xanthine oxidase (16 mu/ml) which generates superoxide anion only extracellularly. The ability of polymixin B (30 microM) to inhibit the development of the depression of vasoconstriction suggests that it results from the expression of an inducible form of nitric oxide synthase, stimulated by bacterial lipopolysaccharide, contaminating the Krebs solution. In contrast to aortic rings, we found that lipopolysaccharide (10-10,000 ng/ml) alone from S. typhosa was unable to stimulate the expression of the inducible form of nitric oxide synthase in rat aortic smooth muscle cells grown in culture from explant, as assessed either by measuring the accumulation of nitrite into the culture medium during a 24 hour incubation period or by measuring the smooth muscle cyclic GMP content. Interferon-gamma (1-100 IU/ml) and interleukin-1 alpha (1-10 IU/ml) alone were, however, able to stimulate the accumulation of nitrite in a concentration-dependent manner. These inductions of nitrite accumulation were abolished following treatment with N(G)-nitro-(L)-arginine methyl ester (1 mM) and dexamethasone (1 microM). Further investigations are required to determine whether the ability of bacterial lipopolysaccharide to induce the inducible form of nitric oxide synthase in rat aortic rings, but not in rat aortic smooth muscle cells in culture, results from the presence of an endotoxin-sensitive, cytokine-secreting cell type in the vessel wall which is absent in culture, or from differences in smooth muscle phenotype in situ and in culture.

Adrenergic alpha-Agonists↗
PubMedDate not supplied

Involvement of tyrosine kinase and protein kinase C in the induction of nitric oxide synthase by lipopolysaccharide and interferon-gamma in J774 macrophages.

The combination of lipopolysaccharide (LPS; 100 ng/ml) and interferon-gamma (IFN-gamma; 10 IU/ml) synergistically stimulated induction of nitric oxide synthase activity in J774 macrophages, measured by nitrite accumulation during an overnight incubation. Neither the phorbol ester, phorbol 12-myristate 13-acetate (PMA; 10(-9) - 3 x 10(-6) M) nor the calcium ionophore, A23187 (10(-7) - 10(-4) M), alone or in combination, stimulated accumulation of nitrite. They were also unable to substitute for IFN-gamma in priming J774 macrophages to stimulation with LPS. Phorbol 12-myristate 13-acetate (10(-9) - 3 x 10(-6) M) produced a concentration-dependent inhibition of nitrite accumulation when added prior to stimulation with LPS and IFN-gamma, but enhanced nitrite accumulation when added 12 hours following stimulation with LPS and IFN-gamma. Of the protein kinase C inhibitors tested, staurosporine (10(-9) - 3 x 10(-6) M) and Ro 31-8220 (3 x 10(-9) - 10(-5) M) produced a powerful, concentration-dependent inhibition of nitrite accumulation when added prior to stimulation with LPS and IFN-gamma, but had only slight inhibitory effects when added 12 hours after stimulation with LPS and IFN-gamma. Chelerythrine chloride ( 10(-8) - 3 x 10(-5) M) produced only a slight inhibition of nitrite accumulation when added prior to stimulation with LPS and IFN-gamma, but slightly enhanced nitrite accumulation when added 12 hours following stimulation with LPS and IFN-gamma. The tyrosine kinase inhibitors, genistein (10(-7) - 10(-4) M) and herbimycin A (5.2 x 10(-9) - 1.74 x 10(-6) M), produced a powerful concentration-dependent inhibition of nitrite accumulation when added prior to stimulation with LPS and IFN-gamma. In contrast, herbimycin A had only a slight inhibitory effect when added 12 hours following stimulation with LPS and IFN-gamma, and genistein had no effect. When used in combination prior to stimulation with LPS and IFN-gamma, herbimycin A (1.7 x 10(-7) M) and staurosporine (3 x 10(-8) M) produced additive inhibitory effects on nitrite accumulation, but herbimycin A, together with Ro 31-8220 (3 x 10(-6) M) or chelerythrine chloride (10(-5) M), produced no further effects. These results provide strong evidence for the involvement of tyrosine kinases in the induction of nitric oxide synthase by LPS and IFN-gamma in J774 macrophages. They also suggest a role for protein kinase C, but elucidation of the precise mechanisms by which this pathway interacts with tyrosine kinase to regulate the expression of nitric oxide synthase requires further investigation.

Animals↗
PubMedDate not supplied

Shear bond strength of immediately repaired light-cured composite resin restorations.

The goal of this study was to examine the extent to which the state of the surface of newly placed restorations made of one of two commercial formulations of composite resin (Pertac-Hybrid and Z-100) affects the interfacial bond strength when such restorations are immediately repaired with the same resin. Three groups of specimens for each material were prepared: one group in which there was an air-inhibited film on the surface of the initial layer of the restoration, another in which that film was prevented from being formed, and a third in which that surface was abraded prior to placement of the repair layer. All specimens were stored for 6 weeks in water at 23 degrees C before being loaded to fracture in shear at a rate of 5 mm/min. The shear bond strength results were treated using the three-parameter Weibull equation and a clearly defined index of performance (I), which is a measure of both the magnitude and variability of the shear bond strength. It was found that, for two states of the surface of the initial layer, I for Pertac-Hybrid specimens is about the same as that for Z-100 specimens. For specimens made of either material, there was a demonstrable difference in I between specimens with or without an air-inhibited film on the initial layer, while abrading the surface of that layer severely degraded I.

Air↗