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Biomedical subjects

P Wilson

Publications and source records attributed to P Wilson.

At least 271 records · Page 15Linked to original sources
PubMed1989

Comparison of an immunocytochemical assay for progesterone receptor with a biochemical method of measurement and immunocytochemical examination of the relationship between progesterone and estrogen receptors.

Using a rat monoclonal antibody raised against human progesterone receptor (PR) we have developed an immunocytochemical technique to detect PR in human normal and malignant breast tissue and have compared the distribution of this with that obtained by the conventional dextran-coated charcoal steroid-binding assay. Immunoreactive PR was detected exclusively in the nuclei of epithelial cells in 29/51 (56.9%) of breast cancers studied. There was an excellent correlation between the immunocytochemical and dextran-coated charcoal techniques, with concordance in 43/51 (84.3%) cases [regression coefficient (Spearman) = 0.78; P less than 0.001]. The relationship between PR and estrogen receptor (ER) was also examined immunocytochemically using a monoclonal antiserum to ER. Twenty-eight out of 51 (54.9%) tumors were positive for both receptors and 13/51 (25.5%) negative for both. ER-positive, PR-negative tumors were found in 9/51 (17.6%) cases whereas only one case (2%) was PR-positive, ER-negative.

Antibodies, Monoclonal↗
PubMed1989

A point mutation G----A in exon 12 of the porphobilinogen deaminase gene results in exon skipping and is responsible for acute intermittent porphyria.

We have determined the mutation in a patient with acute intermittent porphyria. The mRNA coding for porphobilinogen deaminase was reverse transcribed then the cDNA was enzymatically amplified in vitro. Upon sequencing of a polymerase chain reaction product of abnormal size we found that this fragment lacked exon 12 of the gene. We analysed a genomic fragment containing exon 12 and determined that the patient was heterozygous for a point mutation G A at the last position of exon 12. We propose that this base change is responsible for an abnormal processing of the mutant allele such that exon 12 is missing in the mature mRNA. The resulting aberrant mRNA encodes a truncated protein which is inactive but stable and can be detected using antibodies directed against the normal enzyme.

Acute Disease↗
PubMed1989

Rheumatism and the menopause.

Rheumatic problems at or around the menopause include arthralgia and general rheumatic pains, aggravation or first appearance of rheumatoid or osteoarthritis, backache and carpal tunnel syndrome caused by fluid retention. This article looks at such menopausal conditions and describes how to diagnose and manage them.

Aged↗
PubMed1989

An enzymatic assay for picomole levels of phosphatidate.

An assay for phosphatidate that is sensitive, specific, and highly reproducible is described. Phosphatidate is transacylated with methylamine and the glycerol 3-phosphate produced is measured enzymatically. The assay is linear from 50 to 1500 pmol of phosphatidate and can be used to quantitate phosphatidate in small amounts of biological materials.

Animals↗
PubMed1989

Identification of potential allergens in white oak (Quercus alba) pollen by immunoblotting.

Aqueous extracts of white oak pollen were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and transferred onto nitrocellulose membranes. The nitrocellulose membranes were blocked with phosphate-buffered saline 15% nonfat dry milk, incubated with dilutions of sera from atopic or control subjects, and probed with a radiolabeled or peroxidase-labeled antihuman IgE. The IgE binding bands were detected by autoradiography or enzymatic reaction; 45 to 50 protein bands were observed in silver-stained gels. IgE from 30 of the 38 sera tested from oak-sensitive subjects bound to 23 bands with molecular weights (MWs) between 106 to 108 kd (band 1) and 13.2 to 15.2 kd (band 23). No band was recognized by sera of every patient. Band 5 (MW 74.0 to 77.9 kd) and band 21 (MW 16.2 to 17.7 kd) were recognized by 71% of the patients' sera. Multiple bands were recognized by 30% to 50% of the sera tested. All patients who were skin test positive to oak by prick testing had positive immunoblots. Of 12 patients positive by intradermal skin testing, only four patients had positive immunoblots. The average number of allergens recognized by a single patient was 6.6. The maximum number of allergens to which any individual reacted was 18; the minimum number was one. Extracts separated under nonreducing conditions resulted in aggregates that did not enter the polyacrylamide gel. Of the protein that did enter the gel, the higher MW species elicited banding patterns similar to patterns observed under reducing conditions, whereas lower MW IgE binding bands were lost. These data suggest that the extractable proteins of white oak pollen contain multiple proteins that are potentially allergenic.

Blotting, Western↗
PubMed1989

Allergic reactivity to Parthenium hysterophorus pollen: an ELISA study of 582 sera from the United States Gulf Coast.

Parthenium hysterophorus (PH) is a ubiquitous weed found in the U.S. Gulf Coast. In this study, 582 sera, contributed by 22 physicians from 18 Gulf Coast cities, were examined by ELISA for IgE directed against determinants in an aqueous extract of PH pollen, and these were compared to an extract of western ragweed (Ambrosia psilostachya [AP]). Overall, 65.6% of the sera tested were positive for one or both of the pollen extracts examined. Thirty-five percent of the sera were sensitive to PH and 57.6% were sensitive to AP. Thirty percent of the sera were positive to AP only, 8.0% were positive to PH only, and 27.9% of the sera were positive to both extracts. ELISA-inhibition analysis demonstrated that PH and AP extracts contained unique allergenic epitopes. Clinical correlation of in vitro reactivity with skin testing and patients' symptoms confirmed that PH sensitivity by ELISA was related in many cases to fall seasonal symptoms. These data demonstrate by in vitro analysis the presence of IgE directed against an extract of PH pollen in a significant number of patients with fall seasonal pollinosis in the U.S. Gulf Coast. Thus, allergic reactivity to PH may be a significant contributor to fall allergic disease in the U.S. Gulf Coast.

Allergens↗
PubMed1989

Identifying the site of microtubule polymerization during regrowth of UV-sheared kinetochore fibres using antibodies against acetylated alpha-tubulin.

Areas of reduced birefringence (ARBs) produced on chromosomal fibres of crane-fly spermatocyte spindles by ultraviolet microbeam irradiation move poleward. The ARB is due to the depolymerization of the microtubules in that area, and its poleward motion is due in part to the lengthening of that part of the kinetochore fibre which is left attached to the kinetochore after shearing the microtubules. We tested whether the lengthening of this fibre is due to the polymerization of microtubules at the growing edge of the ARB by staining growing fibres in irradiated spindles with antibodies to tubulin and to acetylated tubulin. We have previously argued that newly-polymerized kinetochore microtubules are not acetylated, whereas older kinetochore microtubules are (Wilson & Forer, 1989). Therefore we expected to see an absence of staining with antibodies to acetylated tubulin at the edge of the ARB if microtubules were polymerizing there. There is no absence of staining, however, which suggests that growth of the sheared microtubules does not occur at the ARB edge. Other possibilities are discussed.

Acetylation↗
PubMed1989

Inhibition of growth of nonbasal planes in ice by fish antifreezes.

Peptide and glycopeptide antifreezes from a variety of cold-water fishes cause ice single crystals grown from the melt to assume unusual and strikingly similar habits. The antifreezes inhibit growth on the prism faces but allow limited growth on the basal plane. As new layers are deposited on the basal plane, pyramidal surfaces develop on the outside of the crystal, and large hexagonal pits form within the basal plane. The pits are rotated 30 degrees with respect to the normal orientation of hexagonal ice crystals. Growth inhibition on the prism, pyramidal, and pit faces indicates that these faces contain sites of adsorption of the antifreeze molecules. Several properties of the antifreeze pits are consistent with (but do not prove) an origin of the pits at dislocations. The similarity of crystal habit imposed on ice by antifreezes with wide differences in composition and structure indicates a common mechanism.

Adsorption↗
PubMed1989

An analysis of air-stepping in normal infant vervet monkeys.

Limb movements during air-stepping were analyzed in three neonatal vervet monkeys over a three-week period. The movements had similar temporal organization both across animals and across time. For example, the duration of both the hind and the forelimb cycle equaled about 500 ms, with hind limb return strokes lasting much longer than the hind limb power strokes. Furthermore, there were clear indications of both intra- and interlimb coordination. Specifically, all the joints of a limb tended to flex and extend simultaneously, and contralateral and ipsilateral limb pairs had an average phase relationship of approximately 50% of cycle duration. Despite a qualitative similarity between limb movements during air-stepping in the neonates and overground locomotion in older animals, there were notable differences both in temporal relationships and joint displacement patterns. Finally, there appeared to be important similarities between air-stepping in these monkeys and stepping in newborn humans. Most notably, both tended to disappear after a limited period. The implications of these similarities, as well as the overall results, are discussed in relation to the understanding of the development of locomotor behavior in human and nonhuman primates, using approaches based both upon the hard-wired and dynamic models.

Journal Article↗
PubMed1989

Assessment of nutritional status in noninstitutionalized elderly.

Aging may modify both the availability of and needs for certain nutrients. Our study was done to assess the contribution of age alone to micronutrient levels in older volunteers (aged 60 or more). One hundred two healthy elderly white subjects, 63 women and 39 men, carefully screened by history or chart review, were studied in the fasting state. All were noninstitutionalized without serious chronic or acute illness; their diets were nutritionally adequate, containing more than two thirds of the recommended dietary allowance (RDA) for all nutrients, and no subject was taking more than twice the RDA of fat-soluble vitamins. These subjects had higher levels of plasma and red blood cell carnitine, and vitamins A, E, and C. They had lower levels of albumin, transferrin, and zinc than younger laboratory reference subjects. Retinol-binding protein, serum and red blood cell folate, and copper levels were not different. With increasing age, levels of transferrin and vitamins C and E fell; all other measured micronutrient levels were similar. Albumin, vitamin C, and copper values were higher among elderly women, and plasma and red blood cell carnitine values and zinc levels were higher in elderly men. There was great variability in the micronutrient levels despite similar nutrient intakes.

Age Factors↗
PubMed1989

The behaviour of microtubules in chromosomal spindle fibres irradiated singly or doubly with ultraviolet light.

Areas of reduced birefringence (ARBs) produced by ultraviolet microbeam irradiation are areas of depolymerized microtubules. ARBs probably move poleward either by microtubule subunit addition at the kinetochore and loss at the pole, or by microtubule subunit addition at one edge of the ARB and loss from the other edge. In this paper we have used two approaches to try to distinguish between these two models. First, we determined whether the edges of the ARB move at the same rate; if ARB motion is due solely to addition at the kinetochore and loss at the pole, with the ARB edges unable to exchange subunits, then the two edges of each ARB should move at the same rate. On the other hand, if the exchange is at the ARB edges, then, from data from microtubules in vitro, the poleward edge should move much faster than the kinetochoreward edge. We found that the two edges of the ARB move at the same rate about half the time, but half the time they do not. Second, we studied the behaviour of two ARBs on a single fibre. If ARB motion is due solely to subunit addition at the kinetochore and loss at the pole, then the two ARBs must move poleward together. We found that after two ARBs are formed on a single fibre the region between the ARBs is unstable and rapidly depolymerizes. These results do not fit either model and suggest that influences of kinetochores and poles or other factors need to be considered that are not duplicated in experiments on microtubules in vitro.

Animals↗