Publications by authors named "Heap P"

Background: Early mobilization in intensive care units (ICU) provides respiratory, neurological and cardiovascular benefits in hospitalized patients. However, the orthostatic effects of changing from a supine to a sitting position may interfere with cerebral hemodynamics of patients with aneurysmal subarachnoid hemorrhage (aSAH).

Aim: To describe the changes in mean cerebral blood flow velocity (MCBFV) in supine and sitting position, in adult patients with aSAH, with asymptomatic vasospasm (AVS) or without vasospasm (VS) at a neurosurgical ICU.

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In a post-mortem study, we compared subjects with metal implants with and without visible wear with an age-matched control group to determine the extent and effects of dissemination of wear debris. In subjects with stainless-steel and cobalt-chrome prostheses metal was found in local and distant lymph nodes, bone marrow, liver and spleen. The levels were highest in subjects with loose, worn joint prostheses and the main source of the debris was the matt coating.

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Objectives: To investigate the hypothesis that synovial fluid (SF) from patients with osteoarthritis (OA) may contain calcium phosphate crystals that are either too small, or too few in number to be identified by conventional light microscopy techniques.

Methods: Twelve SF from 11 patients with established knee OA, five SF from patients with rheumatoid arthritis (RA), and two control samples of SF from patients with pseudogout were subjected to an enzyme/hypochlorite extraction procedure. The patients with OA and RA had no radiographic evidence of chondrocalcinosis, or SF crystals on polarised light microscopy.

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This report describes a method for isolating single rabbit atrioventricular (AV) node myocytes which retain their normal morphology when exposed to millimolar levels of calcium. Previous attempts to isolate cells from the AV node have produced myocytes that "round up" (i.e.

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The production of particulate wear debris is a recognised complication of joint arthroplasty, but interest has concentrated on local tissue reactions and a possible association with implant loosening. The fate of wear products in the body remains unknown, although some of the metals used in the construction of orthopaedic implants are known to have toxic and oncogenic properties. We report histological and electron-microscopic evidence from two cases which shows that metallic debris can be identified in the lymphoreticular tissues of the body distant from the hip some years after joint replacement.

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The sites and concentrations of Der p I within the house dust mite were determined. Highest concentrations were found in the epithelium of the posterior end of the mite stomach, implying that this is the site of Der p I synthesis and secretion.

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Air samples taken from the clean air over Bristol were examined using scanning, transmission and X-ray probe micro-analysis. A diversity of material was identified demonstrating the importance of man-made pollutants which have the potential to produce lung damage in addition to pollen moulds.

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A rat model of immediate pulmonary hypersensitivity was used to investigate the permeability changes in the tracheal epithelium produced by aerosol challenge with antigen. The rats were sensitised by the intraperitoneal injection of antigen (dinitrophenyl (DNP19) ovalbumin). Sensitised and control animals were then challenged for 60 minutes with an aerosol of the same antigen, which also contained the electron dense pore marker lanthanum.

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The capacity of human chorionic gonadotrophin (hCG) to raise plasma progestagen levels during the first 8 days of gestation in gilts was examined. The effective half-times of hCG in gilts treated with 500 and 5000 i.u.

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Inbred rats were sensitized by intraperitoneal injection of DNP19 ovalbumin (DNP-OA) or saline. The rats were subsequently challenged by exposure to an aerosol of DNP-OA or bovine gamma globulins (BGG) for 10 min. Tracheal tissue was processed immediately after challenge in fixative containing 1% lanthanum.

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Inbred rats were sensitized by the intraperitoneal injection of 10 micrograms DNP19-ovalbumin (DNP-OA). These rats were compared both in their responses to 10 min of aerosol challenge with DNP-OA or bovine gamma globulins (BGG) and with other rats similarly 'sensitized' with saline and subsequently challenged with DNP-OA. Lanthanum (1%) in the fixative permitted the identification by transmission electron microscopy of electron-dense lanthanum in the tracheal epithelium.

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Environmental and management conditions of 15 herds with a high-prevalence (greater than 70%) of enzootic pneumonia of pigs at slaughter were compared with 16 herds with a low-prevalence (less than 30%) to determine factors commonly predisposing pigs to enzootic pneumonia in South Australia. Comparisons were made of herds having greater than 100 sows (fully intensive units) and also small herds having 20 to 70 sows (sideline units). Half the herds were visited in summer and half in winter to detect seasonal factors.

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Growing pigs were naturally infected with a field strain of Mycoplasma hyopneumoniae to assess the effect of enzootic pneumonia on production. Both the initial ("breakdown") and endemic stages of infection were evaluated. The pigs were reared under environmental and management conditions commonly found on commercial piggeries in South Australia.

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Electron-dense particles, approximately 4 nm (40 A) in diameter were present. Evidence is offered that these particles represent iron probably in the form of amorphous hydrous ferric hydroxide. From X-ray probe analytical data, it is suggested that this iron component is accommodated through the process of adsorption rather than by direct substitution of calcium and phosphorus.

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It has been confirmed that glycosaminoglycan is associated with collagen and other constituents of the anulus fibrosus. In cells, it appears to be present on the rough endoplasmic reticulum and is removed by hyaluronidase digestion and thus may consist of chondroitin sulphate. In pericellular material it appears as fibrils and granules, is unaffected by hyaluronidase and may consist of keratan sulphate or dermatan sulphate.

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The nucleus pulposus of cat intervertebral disc was examined after staining glycosaminoglycans with Alcian Blue and the results correlated with TEM X-ray probe microanalysis. In unstained sections a difference in copper levels between tissues and resin was detected. In tissue stained with Alcian blue before embedding, the copper levels were slightly increased and the morphological appearance of the intercellular material was amorphous.

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1. The role of adenosine 3':5'-phosphate (cyclic AMP) and guanosine 3':5'-phosphate (cyclic GMP) as second messengers for the enzyme secretory response evoked by the autonomic neurotransmitters, noradrenaline and acetylcholine, is examined in this in vitro study on the guinea-pig submandibular gland. 2.

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