Evaluation of light sources and light guides for use in transurethral surgery

An evaluation of the quality of light sources and guides was carried out in response to a demand that sufficient light intensity should always be available for transurethral procedures when bleeding occurs. A light monitor was developed for the rapid assessment of the source intensity and light guide transmission. A simple test protocol was also developed for routine assessment of the sources and guides and for evaluation of new sources and guides before purchase. The sources and guides were classified in order of merit and coded to permit the selection of those of the highest quality; this guarantees a satisfactory level of illumination during surgery.     

Noninvasive detection of ventricular wall motion by electromagnetic coupling

Radiofrequency coils are used as sensors in various applications such as nuclear magnetic resonance (NMR) imaging and displacement cardiograms (DCGs). In most cases the impedance and the resonant frequency of the coil are monitored to provide the required information. The paper describes the changes in reflected impedance and in resonant frequency of a coil when it is placed near a medium with properties ranging from a lossy dielectric to a pure conductor. The theory of interaction between the coil and the medium is investigated and a model based on the use of vector potentials is developed. One prediction of the theory is that placing the coil over body equivalent saline (lossy dielectric) at 15 MHz results in an increase in the inductance of the coil and a resultant decrease in resonant frequency. This prediction was supported experimentally.     

Absence of an association between HLA-DRB1*04 and rheumatoid arthritis in newly diagnosed cases from the community.

OBJECTIVES--To determine HLA-DR4 and DR1 allele frequencies in a series of patients with newly diagnosed early inflammatory arthritis. METHODS--HLA-DR1 and DR4 frequencies were determined by oligonucleotide typing of 208 patients classified as having either rheumatoid arthritis (RA) or undifferentiated inflammatory polyarthritis. RESULTS--The frequency of occurrence of DR4 in these patients with RA did not differ significantly from that in controls in the United Kingdom (42 v 37%). HLA-DR1 was increased in the group with inflammatory polyarthritis (25 v 18%). CONCLUSIONS--The frequency of DR4 is not increased in newly diagnosed community based patients with RA. This supports the hypothesis that DR4 is less important as a marker for susceptibility to RA than it is for disease persistence or severity.     

HLA/Bf haplotypes in a Newfoundland family

HLA/Bf haplotypes were examined in a large three-generation Newfoundland family with a high incidence of Graves' disease. In that family Graves' disease was inherited in association with the haplotype HLA Aw24, Bw39 in some instances and with HLA B8-containing haplotypes in other instances. As all seven members of the family who suffered from Graves' disease were homozygous for the Bf S allele, the study for Bf was uninformative. However, the examination of other HLA/Bf haplotypes disclosed some interesting associations. One-hundred-and-five out of 168 HLA-A, -B, -Bf haplotypes were Bf S. Although numerically deviant, no unusual HLA B/Bf associations were observed. Bf F entered the family only once. A new finding is the association between HLA B27 and Bf S1; the haplotype entered the family once and was passed on to eight family members over three generations. Bf S1 was previously reported in association with HLA B12 or W21. None of these family members had ankylosing spondylitis. The Bf allele F1 entered the family three times, always in association with HLA B18.     

Comparison of Real-Time, Quantitative PCR with Molecular Beacons to Nested PCR and Culture Methods for Detection of Mycobacterium avium subsp. paratuberculosis in Bovine Fecal Samples

An automated PCR with fluorescent probes (molecular beacons) detected Mycobacterium avium subsp. paratuberculosis in bovine feces. When the PCR was compared with culture in testing 41 fecal samples, kappa scores of 0.94 to 0.96, a sensitivity of 93 to 96%, and a specificity of 92% were obtained. Results were quantitated by using a standard curve derived from a plasmid containing IS900. A minimum quantity of 1.7 x 10(-4) pg of DNA, correlating to 1 to 8 CFU, was detected.     

An on-line ultraviolet radiation monitoring system for control of photosensitivity test dose

A system has been developed to monitor and integrate on-line a small fraction of the monochromatic ultraviolet radiation directed at the skin from a phototest source, thus correcting for fluctuations in the irradiance. On completion of the required test dose, the exposure is terminated automatically. Radiation is reflected from a silica plate, housed in a skin applicator, onto a photodiode connected to an integrator. The variation of the reflectivity of the silica plate with wavelength and with incident angle was calculated. The reflectivity of the applicator with and without the silica plate in situ was studied experimentally. Measurements were made of the spatial distribution of irradiance from and across the face of the applicator. To calibrate the photodiode current, the absolute irradiance at the face of the applicator had to be measured with a wide angle detector. No significant deviation from a linear variation was observed between changes in the skin irradiance and changes in the photodiode current.     

Canine unilateral lung transplantation: effect of ciclosporin A on the frequency of donor-lytic lymphocytes

Limiting dilution analysis showed that the frequency of precursor donor-lytic cytolytic lymphocytes increased dramatically within the leucocyte population recovered by broncho-alveolar lavage in dogs after unilateral lung transplantation. The increases for animals experiencing acute pulmonary rejection (11.5-24.8 times pre-operative level) and for those receiving long-term ciclosporin A therapy (5.4-17.6 times pre-operative level) were similar. Therefore, it appears that ciclosporin A does not prevent the sequestration of precursor donor-lytic cytotoxic cells within lung allograft tissue.