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Biomedical subjects

P Haley

Publications and source records attributed to P Haley.

9 recordsLinked to original sources
PubMed1999

CT imaging of intrathoracic lymph nodes in dogs with bronchoscopically administered iodinated nanoparticles.

RATIONALE AND OBJECTIVES: The purpose of the study was to determine if airway instillation of iodinated nanoparticles results in contrast material enhancement of tracheobronchial lymph nodes in dogs. MATERIALS AND METHODS: Eight dogs underwent intrabronchial instillation of iodinated nanoparticles; six dogs received 900 mg each, and two dogs received 450 mg each. Spiral computed tomography (CT) was then performed 2-34 days later. RESULTS: CT scans obtained 2 days after instillation showed the presence of contrast material within the lung parenchyma but no nodal enhancement. Scans obtained 6-34 days after instillation showed enhancement of the right, left, and middle tracheobronchial lymph nodes (analogous to the mediastinal nodes in humans). Mean nodal attenuation on CT images was 117 HU +/- 43, and the mean nodal volume was 129 mm3 +/- 113. Histologic specimens of the nodes showed macrophage hyperplasia. CONCLUSION: Iodinated nanoparticles instilled into small airways are transported to the tracheobronchial lymph nodes, where they result in contrast enhancement.

Administration, Topical↗
PubMed1998

Critical pathway for the emergency department management of acute asthma: effect on resource utilization.

STUDY OBJECTIVE: To determine the effect of a critical pathway on resource utilization in asthmatic patients. METHODS: The study combined a prospective analysis of 149 patients with asthma treated by a pathway protocol with a retrospective analysis of 97 patients with asthma treated by conventional means. The setting was a community hospital. RESULTS: Among patients treated by protocol, oxygen use declined by 19% (P = .001), handheld nebulizer treatments by 33% (P = .001), saline locks by 15% (P = .011), and intravenous steroid administration by 13% (P = .034). There was an increase in the use of metered-dose inhalers with spacer by 64% (P = .001) and oral steroids by 18% (P = .027). CONCLUSION: A critical pathway, based primarily on national guidelines, can be an effective means of treating asthma patients in terms of resource utilization.

Acute Disease↗
PubMed1991

Experimental murine hypersensitivity pneumonitis.

To establish a model of experimental hypersensitivity pneumonitis (EHP) in mice and to examine the influence of genetic background on the pulmonary inflammatory response to Micropolyspora faeni, we determined the responses of C57BL/6, SJL/J, and C3H/HeJ mice to intratracheal (i.t.) injections of M. faeni. Recipient animals received lymph node cells (LNC), peritoneal exudate cells (PEC), and spleen cells (SC) from sensitized mice cultured in vitro with M. faeni. Controls included serum containing anti-M. faeni antibody; uncultured SC from M. faeni-sensitized donors, and M. faeni-cultured SC from ovalbumin (OA)-sensitized donors. Recipients were challenged i.t. with M. faeni or normal saline 48 hr after the cell or serum transfer. We developed a model of EHP in mice. Increasing amounts of i.t. M. faeni were associated with increasing extent of pulmonary inflammation with no difference between the mouse strains. There was substantial increase of the extent of pulmonary abnormalities in the animals receiving cultured SC. The number of transferred cells and the M. faeni concentration correlated with the extent of pulmonary histologic abnormalities. Cultured PEC and LNC could transfer EHP in C3H/HeJ mice only. Serum containing anti-M. faeni antibody, cultured SC from OA-sensitized donors, and noncultured SC from sensitized donors could not transfer EHP. We conclude that it is possible to adoptively transfer EHP.

Actinomycetales↗
PubMed1990

Surface-dependent reactions of the vitamin K-dependent enzyme complexes.

During the past 20 years contributions from many laboratories have led to the development of isolation procedures, delineation of primary structures, and more recently, to the expression of recombinant proteins associated with the coagulation cascade. In general, studies of coagulation proteins under defined conditions have demonstrated the prescience of Davie and Ratnoff and MacFarlane in their proposals of the coagulation cascade. The more recent discovery of thrombomodulin by Esmon et al has led to the identification and characterization of components of the vitamin K-dependent anticoagulant pathway. In this review we have attempted to analyze and compare the functional properties of each of the vitamin K-dependent enzyme complexes associated with the procoagulant and anticoagulant phases of blood clotting. Although dissimilarities exist, the vitamin K-dependent complexes have analogous requirements and appear to function with a common general mode of organization. Membrane-bound cofactors serve as anchoring sites for the appropriate membrane-binding enzymes. This process localizes the complex on the membrane surface and increases the catalytic efficiency for substrate utilization. Complex formation provides extraordinary improvements in the catalytic efficiency for the complexes as compared with their soluble enzyme components. Membrane-bound complexes provide a mechanism that can be regulated at a site by membrane presentation, zymogen activation, and cofactor activation or presentation. The kinetic constants obtained for the various coagulation reactions determined in vitro provide some insights into how these pathways may function in vivo. The catalytic efficiency (kcat/Km) for factor X activation by factor VIIIa/factor IXa is far in excess of the catalytic efficiency of activation of factor X by tissue factor/factor VIIa (Table 3). This may provide a rational interpretation for the observation that patients with hemophilia A and B bleed even though they appear to have an alternative pathway to factor X activation. In addition, tissue factor is not ordinarily presented by the vascular tissue that has direct access to blood. However, it appears that extravascular constitutive tissue factor is available once the blood vessel becomes disrupted. The efforts to identify the initiating reactions of the blood coagulation process have not been unambiguously successful. We conclude that factor VII is most likely a zymogen, just as are the other proenzymes of the blood clotting process. In addition, it is difficult to rationalize the importance of the intrinsic pathway of coagulation involving factor XII, prekallikrein, and high molecular weight kininogen since the congenital absence of any one of these factors does not result in abnormal bleeding.(ABSTRACT TRUNCATED AT 400 WORDS)

Blood Coagulation↗
PubMed1989

Prospective study of routine scrotal ultrasonography in urological practice.

The value of routine scrotal ultrasonography has been evaluated in a prospective study of 109 men with scrotal symptoms or signs. Ultrasonography had a sensitivity of 100% and specificity of 99% for testicular tumour. Clinically useful information was provided in 53% of patients and 8% might have avoided surgery if the ultrasound report had been heeded. Ultrasonography did not provide any additional information in patients with scrotal pain and an entirely normal scrotum clinically, and in those with epididymal cysts in whom the testis was palpably normal. If these 2 groups had been excluded from routine scrotal ultrasonography there would have been a 25% reduction in the number of examinations without any reduction in diagnostic yield.

Adolescent↗