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Biomedical subjects

P J Scott

Publications and source records attributed to P J Scott.

At least 19 recordsLinked to original sources
PubMed2002

Outcome after radial forearm, gastro-omental, and jejunal free flaps in oral and oropharyngeal reconstruction.

We undertook a retrospective study of the outcome of radial forearm, gastro-omental, and jejunal free tissue transfer for oral and oropharyngeal reconstruction in 30 patients (10 in each group). No significant differences were found between the type of free flap and the clinical outcome. More long-term difficulties were experienced with swallowing than with speech. The selection of free flap did not correlate with speech function (P=0.44), swallowing (P=0.68), or management of saliva (P=0.59). No significant difference was found between the patients' outcome and the site of resection of the tumour. There were more complications after gastro-omental flaps and this may influence the choice of reconstruction.

Adult↗
PubMed1998

Does the "Thunderbirds syndrome" still exist.

Rationing of resources within both the private and public health care systems is a fact of life. The Thunderbirds TV series encapsulated an idealistic philosophy that life should be saved independent of the pecuniary cost. Doctors, in particular, are trapped between their role as advocates for the patient within the "Thunderbirds" philosophy and as citizens with a responsibility to use resources wisely. This dichotomy is challenged by point of care rationing, which can conflict with clinical responsibilities, undermines the patient-doctor relationship and is often undertaken in a clandestine manner. This form of controlling health costs is difficult to justify from an ethical perspective, particularly when other forms of health care rationing and expenditure are frequently modulated by political expediency and inadequate economic modelling. Indeed, focusing on improving quality and disease prevention, rather than reducing marginal costs can often control the long-term growth in health expenditure. Doctors have a responsibility to ensure that rationing decisions are made but these should be made as part of a transparent, evidence-based and democratic process away from the point of care. While the resources to implement the "Thunderbirds Syndrome" have never been available, the philosophy must remain at the heart of patient-doctor relationship.

Cost Control↗
PubMed1997

Consensus viewpoint on the treatment of postmenopausal osteoporosis. The Ad Hoc Group on Osteoporosis.

Treatment for postmenopausal osteoporosis should be offered to those with a history of fractures following minimal trauma or with a bone density significantly below the range seen in young normal adults. Underlying diseases contributing to the reduced bone density should be sought and treated appropriately. Lifestyle issues such as smoking, alcohol intake and exercise should be addressed. A calcium intake of at least 1.5 g/day should be achieved. Hormone replacement therapy is the first line pharmacological intervention. The bisphosphonates provide a satisfactory alternative for those unable or unwilling to take hormone replacement therapy.

Bone Density↗
PubMed1996

Effects of catecholamines on isolated human colonic smooth muscle.

1. The effects of catecholamines and some adrenoceptor agonists and antagonists on isolated preparations of human colonic smooth muscle obtained from surgical resections were examined. 2. Strips of circular smooth muscle displayed rhythmic myogenic spontaneous contractions which were inhibited by catecholamines with an order of potency of isoprenaline (1.0) > noradrenaline (0.32) > adrenaline (0.2). Phentolamine (0.7 microM) significantly shifted the noradrenaline concentration-response curve (CRC) to the right but had no significant effect on isoprenaline or adrenaline. Propranolol (1 microM) significantly shifted the isoprenaline to the right but had no significant effect on noradrenaline or adrenaline. 3. Salbutamol (30 microM) had no inhibitory effect on the spontaneous activity and ICI 118,551 (1 microM) had no effect on inhibitory responses to isoprenaline. Betaxolol (1 microM) significantly shifted the CRC to isoprenaline to the right. BRL 37344 had no effect on spontaneous activity. 4. Responsiveness of circular strips to catecholamines was not affected by age of the patient and no consistent differences between males and females were shown. 5. Strips of taenia coli exhibited little or no spontaneous phasic activity. Noradrenaline and isoprenaline relaxed KCl-induced tone. The effects of noradrenaline and isoprenaline were antagonized by propranolol but not by phentolamine. BRL 37344 had no effect on KCl-induced tone. 6. In conclusion, catecholamines relaxed spontaneous activity of human colon circular smooth muscle through an action on both alpha- and beta-adrenoceptors. The alpha-adrenoceptors were of the alpha 1-subtype. The beta-adrenoceptor-mediated relaxation appeared to be primarily beta 1. In taenia coli, catecholamines relaxed KCl-induced tone via beta-adrenoceptors only.

Adrenergic alpha-Agonists↗
PubMed1995

No evidence for a general change in contractile responsiveness of the mesenteric artery with aging.

Rings of human mesenteric artery (1-3 mm diameter) suspended in Krebs solution were contracted (maximal contraction relative to KCl 80 mM = 100%) by the thromboxane mimetic U46619 (190 +/- 10%), noradrenaline (162 +/- 9%), angiotensin II (107 +/- 11%), and 5-hydroxytryptamine (5-HT) (96 +/- 10%). Reducing extracellular Ca2+ strongly inhibited the maximal contraction to angiotensin II and 5-HT and moderately inhibited the maximal contraction to noradrenaline, but had less effect on the maximal contraction to U46619 (contraction in Ca2+ 1.3 microM was reduced to 24 +/- 5, 20 +/- 3, 38 +/- 4 and 52 +/- 4% respectively of the contraction in 2.5 mM Ca2+). Reducing extracellular Ca2+ lowered sensitivity to 5HT, angiotensin II, and U46619, but did not alter sensitivity to noradrenaline. The EC50 and maximal contraction for each of the 4 agonists did not change with patient age at 2.5 mM Ca2+ or in reduced extracellular Ca2+. It is concluded that aging does not affect the responsiveness of mesenteric arterial smooth muscle to physiological vasoconstrictors.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1995

Adhesion receptor phenotypes of murine lung CD4+ T cells during the pulmonary immune response to sheep erythrocytes.

Understanding the molecular mechanisms of pulmonary lymphocyte recruitment is a crucial step toward selective control of immune lung diseases and infections in immunocompromised hosts. To dissect these mechanisms, we are studying the response induced in primed C57BL/6 mice by intratracheal challenge with the T cell-dependent antigen, sheep red blood cells (SRBC). This study used four-parameter flow cytometry to examine expression by CD4+ murine T cells in peripheral blood and lungs of receptors known to be differentially expressed on primed human lymphocytes (CD2, CD11a, CD44, CD45RB, CD49d, and L-selectin). Compared with peripheral blood, more lung CD4+ T cells recovered by bronchoalveolar lavage (BAL) showed a primed phenotype. Judged by low expression of CD45RB or L-selectin, 76 to 90% of BAL CD4+ T cells were primed at all times. Adhesion receptor phenotype of CD4+ T cells in BAL and lung interstitium agreed closely, although BAL contained a greater percentage of primed cells. The percentage of CD4+ T cells with high expression of CD44+ and CD49d increased late in the response. However, when considering only upregulated adhesion receptors which might mediate recruitment, 22 to 52% of CD4+ T cells in BAL did not have increased adhesion receptor expression. Longer duration between priming and challenge did not increase adhesion receptor upregulation. High adhesion receptor expression was least evident during the periods of maximal lymphocyte influx, suggesting that factors other than increased surface density of organ-nonspecific adhesion receptors contribute to lymphocyte recruitment during pulmonary immune responses.

Animals↗
PubMed1994

Helicobacter pylori and chronic antral gastritis in elderly patients.

Fifty-five elderly patients with chronic antral gastritis (CAG) were studied to assess the relationship between Helicobacter pylori (H. pylori) status and CAG subtypes as specified in the Sydney System for Gastritis Classification. Twenty-eight patients (51%) were H. pylori positive and 27 (49%) H. pylori negative. H. pylori-positive patients had a significantly greater association with features of severe active CAG (chronic inflammation and polymorph activity) than H. pylori-negative patients. No association was apparent between H. pylori and more advanced stages of CAG (atrophy and intestinal metaplasia) thought to carry pre-malignant potential. The recognized association between dyspeptic symptoms in elderly people and an H. pylori-positive gastritis was confirmed. Use of NSAIDs correlated with a predominantly H. pylori-negative gastritis which was relatively asymptomatic.

Aged↗
PubMed1994

Experimental murine pulmonary cryptococcosis. Differences in pulmonary inflammation and lymphocyte recruitment induced by two encapsulated strains of Cryptococcus neoformans.

BACKGROUND: Cryptococcus neoformans, the most common cause of lethal mycosis in AIDS, usually causes only subclinical pneumonitis in normal hosts. However, cryptococcosis can induce various pulmonary inflammatory reactions, and pulmonary cellular immunity is postulated to prevent dissemination. We hypothesized that cryptococcal strains possess different capacities to induce recruitment to the lungs of inflammatory cells, especially lymphocytes, which are necessary for cryptococcal clearance. EXPERIMENTAL DESIGN: We examined the pulmonary response of CBA/J mice to intratracheal inoculation with C. neoformans of either of two strains: 52D (ATCC 24067), which rarely kills immunocompetent mice; and 145A (ATCC 62070), which is uniformly fatal. From 2-42 days after inoculation, lungs were either examined grossly and microscopically or were enzymatically digested and inflammatory cells counted and analyzed by flow cytometry. At 42 days, organism burden in lung and brain was quantified by colony-forming unit assay. RESULTS: Pulmonary inflammation differed greatly between the two strains. Strain 52D induced dense perivascular and alveolar inflammation; infection progressed to day 21 and then waned. In contrast, strain 145A induced delayed, meager lymphocytic infiltration and slight alveolitis; organisms grew progressively. Recovery of inflammatory cells increased by day 13 with strain 52D, but not until day 31 with strain 145A. Although all lymphocyte subsets were greater in 52D infection, the disparity was greatest for CD4+ T cells. Nevertheless, lymphocytes from paratracheal nodes of infected mice proliferated in vitro to heat-killed cryptococci, indicating immune recognition of both strains. At day 42, strain 52D lightly infected lungs but not brain, whereas strain 145A heavily infected lungs and brain. CONCLUSIONS; Cryptococcal strains differ in their capacity to induce pulmonary cellular inflammation, especially CD4+ T cell recruitment. Our results suggest that strain-specific difference in the organism's ability to induce (or evade) pulmonary inflammation contributes to the outcome of infection.

Animals↗
PubMed1993

Vasodilator action of cromakalim on human mesenteric artery.

Human mesenteric artery rings (1-3 mm diameter obtained from bowel resections), precontracted with KCl 80 mM, were relaxed by cromakalim (IC50 = 0.39 +/- 0.04 microM, maximum inhibition 69 +/- 2%). Cromakalim was more effective at inhibiting KCl 40 mM than KCl 80 mM. Cromakalim also inhibited contraction produced by noradrenaline, and was a more potent inhibitor of the second phase of the noradrenaline contraction than of the first phase.

Aged↗
PubMed1993

Imaging of pulmonary vascular disease by intravascular ultrasound.

To assess the ability of intravascular ultrasound (IVUS) to image changes in the pulmonary arterial wall associated with pulmonary hypertension (PHT), 10 subjects requiring diagnostic right and left heart catheterization were studied. In addition to measurements of pulmonary artery pressure and pulmonary vascular resistance and pulmonary angiography, when indicated, all underwent simultaneous IVUS imaging in the pulmonary arterial system using a 20 MHz ultrasound transducer mounted on a 2 mm diameter catheter. Four patients had normal pulmonary artery pressures and 6 had varying degrees of PHT. Satisfactory ultrasound images were obtained in 9 out of the 10 patients. In those with normal pulmonary artery pressures ultrasound showed a thin vessel wall with no distinction between separate layers. In patients with systemic PHT, a three-layered vessel wall was apparent and areas compatible with intimal proliferation were seen. In a patient with pulmonary embolic disease areas consistent with mural thrombus were detected at sites of luminal narrowing on the pulmonary angiogram. IVUS is capable of imaging some of the morphological changes in the wall of the pulmonary artery known to occur in longstanding PHT and may therefore become a useful adjunct to haemodynamic measurements and pulmonary angiography for the in vivo assessment of pulmonary vascular disease.

Adolescent↗
PubMed1993

Bovine internal mammary artery as a conduit for coronary revascularization: long-term results.

Graft patency after coronary artery bypass grafting depends largely on the choice of conduit. Because an increasing number of patients have insufficient or poor-quality autologous material, there is a need for a suitable synthetic graft that is readily available and easy to handle and that has good long-term patency. Early results suggest that the bovine internal mammary artery graft may meet these criteria. We have used a total of 26 such grafts in 18 patients. Postoperative angiography has been performed in 19 grafts in 14 patients, 3 to 23 months after operation; of these grafts, 3 are currently patent (15.8%, compared with 85.7% and 75.0% patency for native internal mammary artery and saphenous vein grafts in the same patients). We report the results of clotting studies and an analysis of lipid status. These patients do not, however, appear to represent any atypical group, either in terms of coagulopathy, native coronary artery size, or the type of vessel disease. Nevertheless, our poor results contrast markedly with the early enthusiasm reported from other centers.

Aged↗
PubMed1993

Apical hypertrophic cardiomyopathy presenting as acute subendocardial myocardial infarction.

Two patients with apical hypertrophic cardiomyopathy presented with angina at rest and giant inverted T waves in precordial leads on the electrocardiogram. At cardiac catheterisation one patient had mild coronary artery disease, the other had normal coronary arteries. In both, there was a systolic pressure gradient between the apex and main left ventricular cavity exceeding 100 mmHg. The presence of rest angina with the electrocardiographic findings lead to a mistaken, initial diagnosis of acute subendocardial myocardial infarction.

Angina Pectoris↗
PubMed1992

Reconstitution of defective respiratory burst activity with partially purified human neutrophil cytochrome B in two genetic forms of chronic granulomatous disease: possible role of Rap1A.

Neutrophil plasma membranes from patients with the X-linked and autosomal recessive forms of chronic granulomatous disease (CGD) that lack cytochrome b are incapable of generating superoxide anion (O2-) in vivo and in vitro. The O2- generating activity of these defective membranes was reconstituted with the addition of partially purified human neutrophil cytochrome b in a detergent-based, cell-free activation system. Depending on the detergent system used, 50% to 100% of the activity of control membranes was recovered, and this activity was directly dependent on the cytochrome b concentration. However, when cytochrome b was purified to 99% homogeneity, the reconstitutive capacity of the cytochrome was lost, possibly because of subtle denaturation of the cytochrome or the removal of an additional required cofactor. Examination of the latter possibility with respect to a protein known to coassociate with the cytochrome, ie, Rap1A, indicated that this ras-like protein was present in the partially purified cytochrome preparation used to reconstitute activity in CGD membranes, but was missing in the highly purified preparation. However, the finding that Rap1A was present in normal amounts in the neutrophil membranes from all four major types of CGD (including those missing cytochrome b) suggested that the conditions required of the reconstitution assay did not favor the reassociation of the membrane-derived Rap1A with exogenously added cytochrome b or that another unidentified membrane component was lost during the final purification step. The normal expression of Rap1A in CGD cell membranes also indicates that this protein is not responsible for the absence of O2- production in the X-linked and autosomal recessive cytochrome b-negative forms of CGD. Finally, these results show that the expression of Rap1A in the plasma membrane is not dependent on the coordinate expression of cytochrome b, despite the close association shown for these two proteins in the normal cell membrane.

Cytochrome b Group↗