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Biomedical subjects

J Ayres

Publications and source records attributed to J Ayres.

At least 55 records · Page 3Linked to original sources
PubMed1981

Statistical methods for studying homozygous typing cells of unknown specificity.

A situation can arise in D typing in which the HLA (A,B,C,D, or DR) specificities of the responders are known and the specificities of the HTC's are unknown. The most powerful and direct method of detecting association between the unknown stimulator (HTC) and any given HLA specificity is by comparing the observed double normalized values (DNV's) of individuals known to be positive for the specificity with the DNV's of negative individuals. This can be done by comparing the two groups with a Kolmogorov-Smirnov test (K-S test), an established statistical procedure for evaluating correlation between continuous variables, such as the DNV, and discrete variables (such as presence of D type). The application of the K-S test will generate as a "cutoff" value of point that maximizes the average of the frequencies of correct assignments in D positives and D negatives. We also propose an alternative method of computing the "r" value. We have analyzed 49 HTC's from the 8th International Workshop and present the association observed with the D and DR specificities.

Alleles↗
PubMed1981

An improved method for sacro-iliac joint imaging: a study of normal subjects, patients with sacro-iliitis and patients with low back pain.

A new method is described for quantitative measurement of the uptake of 99mTc--methylene diphosphonate (MDP) by the sacro-iliac joints. The method uses 'regions of interest' providing advantages over the previously described 'slice' method; the two methods are compared in normal subjects, patients with known sacro-iliitis and patients with low back pain. Sacro-iliac activity, as calculated by the sacro-iliac index (SII) in normal patients, was shown to decrease with age in females but not in males. The SII was compared with radiographs of the sacro-iliac joints in the patients with known sacro-iliac joint disease and in those with low back pain. The method is useful for the exclusion of sacro-iliitis as a specific cause of back pain.

Adolescent↗
PubMed1981

Effect of inhaled alpha-blocker on airflow obstruction in asthma.

A controlled study of the effect on airflow obstruction of 30 mg of the alpha-blocker thymoxamine given by inhalation is reported in 10 patients with chronic stable asthma. No significant change in peak expiratory flow rate was seen with either thymoxamine or placebo in any patient. Alpha-adrenergic receptors are therefore unlikely to contribute significantly to resting bronchomotor tone in chronic stable asthma.

Adult↗
PubMed1981

Patient consent.

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Emergency Medical Services↗
PubMed1981

Good Samaritan laws.

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Emergency Medical Services↗
PubMed1979

Antipyretic effect of acetaminophen suppositories in rats.

An animal model used yeast-fevered rats to measure the relative antipyretic effects of different commercially available acetaminophen-containing suppositories. A laboratory-prepared acetaminophen-containing suppository and placebo suppositories also were investigated. Release from the suppositories was measured in vitro. All acetaminophen products containing 600 mg of drug elicited significant decreases in the rectal temperature of fever-induced rats.

Acetaminophen↗
PubMed1979

Saliva, urine and plasma analysis of dyphylline via HPLC.

Improved assay methods for determination of dyphylline levels in plasma, saliva, and urine utilizing high pressure liquid chromatography have been developed. Detection of levels as low as 25 ng/ml from 0.5 ml plasma and 50 ng/ml from 0.5 ml saliva were possible. Both procedures utilized the same extraction process. A separate extraction process was used for dyphylline analysis in urine due to the presence of interferring substances occurring with previous methods. The method was applied to samples of one subjects plasma, saliva and urine after administration of dyphylline.

Chromatography, High Pressure Liquid↗
PubMed1976

HLA-B specificities and w4, w6 specificities are on the same polypeptide.

The human alloantigenic specificities w4 and w6, which are products of a diallelic system genetically associated with the HLA-B locus, have been solubilized by papain digestion of membranes from the lymphoblastoid cell line, RPMI 4265. The w4 and w6 specificities copurified with the HLA-B locus products, HLA-B7 and HLA-B12. Sequential immunoprecipitation experiments were performed using alloantisera to HLA-B7, HLA-B12, w4 and w6, and a purified HLA-B7, B12, w4, w6 antigen pool labeled with 125I-Bolton-Hunter reagent. These experiments demonstrated directly that HLA-B7 and w6, which are genetically associated with each other, are different antigenic determinants on the same molecule, while HLA-B12 and w4, also genetically associated, are distinct antigenic determinants on a second molecule. Arguments are presented which suggest that the HLA-B determinants and w4, w6 determinants are in fact on the same polypeptide, and the genetic implications of the findings are discussed.

Alleles↗