Assessment of psoriatic plaque in vivo with correlation mapping optical coherence tomography.

BACKGROUND/PURPOSE: Vascular abnormalities play an acute role in the pathogenesis of psoriasis. In order to characterize vascular involvement in psoriasis and its regular clinical assessment in vivo, non-invasive high speed imaging with high resolution and high sensitivity is needed. METHODS: The correlation mapping optical coherence tomography (cmOCT) technique was used for in vivo microcirculation imaging of human forearm under normal and psoriatic conditions. The cmOCT technique developed by our group uses dense scanning OCT image acquisition and post-processing software based on correlation statistics. The frequency domain OCT system was used for imaging which acquires a 3D volume of 1024 × 1024 A-scans, each of 512 pixels deep in approximately 70 s. The cmOCT technique processes the resulting OCT volume within 116 s using a 7 × 7 kernel. RESULTS: 3D structural and functional (microcirculation) maps of the healthy tissue and the psoriatic plaque were obtained using the cmOCT technique. The presented results indicate that cmOCT allows not only the identification of the microvessels, but also produces more detailed microvascular networks showing how the blood vessels relate to each other in healthy tissue and within the plaque. The microcirculation pattern within the plaque is totally different from the healthy tissue. The distinct changes are also observed in vessel density, tortuosity, and orientation. CONCLUSION: The cmOCT provides high sensitivity and imaging speed for in vivo microcirculation imaging within the human skin under normal and diseased conditions.

Monitoring and dispersion modelling of emissions from the fluidised bed combustion of poultry litter.

Gaseous emissions from the fluidised bed combustion of chicken litter were monitored and recorded. Emission data was used to create a dispersion model for a proposed site on a poultry farm in Limerick, Ireland. Variables within the combustion unit not only influenced combustion but also emission levels of pollutants such as SO2 and NOx. CO emissions decreased with use of the correct ratio between fluidising and secondary air, the staging of secondary air and the degree of turbulence with which the secondary air is introduced. Dispersion modelling of actual combustion at a proposed poultry unit predicted that ground level concentrations for the set of emissions data would be below the limits and guidelines set by air quality standards. This was true for both and line source. Line source concentration levels were less than those for point source.

Emissions modeling of fluidised bed co-combustion of poultry litter and peat.

Gaseous emissions from the fluidised bed co-combustion of 50% w/w chicken litter and peat were monitored and recorded. Emission data were used to create a dispersion model for a proposed site on a poultry farm in Ireland. Variables within the combustion unit influenced both combustion and emission levels of pollutants such as SO(2) and NO(x), CO. Concentrations of atmospheric pollutants decreased with use of the correct ratio between fluidising and secondary air. Dispersion modelling of combustion at a proposed poultry unit predicted that ground level concentrations for the set of emissions data would be below the limits and guidelines set by air quality standards.

Advances in poultry litter disposal technology--a review.

The land disposal of waste from the poultry industry and subsequent environmental implications has stimulated interest into cleaner and more useful disposal options. The review presented here details advances in the three main alternative disposal routes for poultry litter, specifically in the last decade. Results of experimental investigations into the optimisation of composting, anaerobic digestion and direct combustion are summarised. These technologies open up increased opportunities to market the energy and nutrients in poultry litter to agricultural and non-agricultural uses. Common problems experienced by the current technologies are the existence and fate of nitrogen as ammonia, pH and temperature levels, moisture content and the economics of alternative disposal methods. Further advancement of these technologies is currently receiving increased interest, both academically and commercially. However, significant financial incentives are required to attract the agricultural industry.

Principles and practice of the laser-Doppler perfusion technique.

This paper reviews the development and use of laser-Doppler perfusion monitors and imagers over the past two decades. The enormous interest in microvascular blood perfusion coupled with the 'ease of use' of the technique has led to 1500+ publications citing its use. However, useful results can only be achieved with an understanding of the basic principles of the instrumentation and its application in the various clinical disciplines. The basic theoretical background is explored and definitions of blood perfusion and laser-Doppler perfusion are established. The calibration method is then described together with potential routes to standardisation. A guide to the limitations in application of the technique gives the user a clear indication of what can be achieved in new studies as well as possible inadequacy in some published investigations.

Fluorescence In Situ Hybridization: Trisomy 12 Follow-up In Hairy Cell Leukemia.

Peripheral white blood cells from five patients with hairy cell leukemia (HCL) were studied applying fluorescence in situ hybridization (FISH) using heparinized peripheral blood, biotin-labeled chromosome 12-specific α satellite DNA probe and biotin fluorescein-labeled avidin to detect hybridization. This methodology is ideal to investigate the incidence of numerical chromosomal abnormalities of both interphase and metaphase cells. Blood samples from 28 normal subjects were included as control samples. Trisomy 12 was considered to be present when ≥4% of cells had three hybridization spots. Trisomy 12 was detected in three of the five patients at different stages of their evolution. Trisomy 12 was also evident in two patients upon relapse of the HCL. When treatment with interferon alfa (IFN) and steroids was started, clinical and analytical remission were achieved and trisomy 12 disappeared. In one patient trisomy 12 persisted regardless of treatment with IFN and a good clinical evolution. Our results show that trisomy 12 was detected in HCL with FISH at a higher frequency than that previously reported by cytogenetic analysis in either peripheral blood or in cultivated cell lines. These results indicate that the presence of trisomy 12 may be a useful marker for the presence of HCL cells, to check the percentage of trisomic cells and that trisomy 12 is also a useful marker to indicate the activity of the disease.

Physician-induced demand: an empirical analysis of the consumer information gap.

The hypothesis of physician-induced demand is examined empirically in a model where variation in consumer information affects health-care utilization. A theoretical framework is posited under which demand-inducing physicians will provide more services, ceteris paribus, to their medically uninformed patients. Using data from the CHAS-NORC National Survey of Access to Medical uninformed patients. Using data from the CHAS-NORC National Survey of Access to Medical Care 1975-1976, physician office visit demand equations are estimated. The key finding is that medical professionals and their families are as likely, if not more likely, to visit physicians as other people, controlling for sociodemographic factors, price factors, access to care factors and perceived health status.