Search PubMed⌕ Search

Biomedical subjects

W Sewell

Publications and source records attributed to W Sewell.

10 recordsLinked to original sources
PubMed1998

Chronic cough resembles asthma with IL-5 and granulocyte-macrophage colony-stimulating factor gene expression in bronchoalveolar cells.

BACKGROUND: Chronic cough is a multifactorial condition, which, like asthma, can be associated with eosinophilic airway inflammation. In asthma, airway eosinophilia is believed to be mediated by cytokines such as interleukin-5 and granulocyte-macrophage colony stimulating factor (GM-CSF). The role of these cytokines in chronic cough is unclear. OBJECTIVE: The aim of this study was to examine gene expression for IL-5 and GM-CSF in chronic cough and compare the results with those found in asthma. METHODS: We studied adults with asthma (n = 12), chronic cough responsive to inhaled corticosteroid (ICS-responsive cough) (n = 9), and chronic cough not responsive to inhaled corticosteroid (non-ICS-responsive cough) (n = 4). Bronchoalveolar lavage (BAL) was performed, and cytokine gene expression was assessed by using a semiquantitative reverse transcriptase polymerase chain reaction. RESULTS: IL-5 mRNA was expressed by BAL cells from nine of 12 asthmatic subjects and six of nine subjects with ICS-responsive chronic cough. IL-5 mRNA was not detected in subjects with non-ICS-responsive chronic cough (zero of four subjects, p < 0.05). GM-CSF mRNA was expressed in BAL cells from seven of 12 asthmatic subjects and six of nine subjects with ICS-responsive cough. GM-CSF mRNA was not detected in non-ICS responsive cough subjects (zero of four subjects, p < 0.05). GM-CSF gene expression was related to the degree of methacholine airway responsiveness in asthmatic subjects (r = -0.59). CONCLUSION: We conclude that chronic cough, like asthma, is associated with airway inflammation and gene expression for IL-5 and GM-CSF. Ongoing expression of these cytokines is likely to be related to the persistence of airway inflammation and chronic cough.

Administration, Inhalation↗
PubMed1993

Expression of the Fc receptor for IgG (Fc gamma RII/CDw32) by human circulating T and B lymphocytes.

Tissue-specific isoforms of the human FcR for IgG Fc gamma RII (CDw32) have previously been described by using mAb. These mAb were shown to exhibit different patterns of reactivity with lymphocytes. Among human PBL, Fc gamma RII has been detected on B cells but not T cells when assessed by flow cytometry and microscopy with the use of mAb KB61 and 41H16. Although KB61 and 41H16 were found to react with B cells, the mAb IV.3, CIKM5, and 2E1 did not react with any PBL subset. In this study, we show that KB61 and 41H16 react strongly with the majority (93-96%) of B cells (CD20+), and weakly with a proportion (18-42%) of T cells (CD3+), including 10 to 14% of CD4+ and 27 to 69% of CD8+ cells. In addition, mRNA for Fc gamma RII was detected in purified CD3+CD8high+ lymphocytes by polymerase chain reaction. KB61 and 41H16 also reacted with a majority of CD3-CD16/CD56+ cells, and CD3-CD20- cells. These findings indicate that a subset of T cells and non-T/non-B cells express Fc gamma RII, and are of interest in the light of previous studies which postulate that human Fc gamma R+ cells and Fc gamma RII+ murine T cells suppress the B cell immune response.

Animals↗
PubMed1993

Value of technetium 99m sestamibi iodine 123 imaging in reoperative parathyroid surgery.

BACKGROUND: The purpose of this study was to assess the contribution of technetium 99m sestamibi iodine 123 (T/S) imaging to preoperative and intraoperative management of patients with persistent hyperparathyroidism. METHODS: During a period of 10 months, all patients being prepared for reoperative parathyroid surgery (n = 10), two patients deemed significant operative risks (one patient with severe chronic obstructive pulmonary disease and one patient with severe cervical spine ankylosing spondylitis), and two patients who had undergone prior thyroid operation were studied with T/S imaging. Six patients undergoing reoperative surgery had undergone one, three had undergone two, and one had undergone three prior procedures. RESULTS: T/S imaging correctly localized 14 of 16 parathyroid tumors. By comparison, only 1 of 6 thallium technetium and 3 of 12 computed tomography (CT) scans (in seven patients) were positive. T/S imaging guided the reoperative surgical approach accurately in 12 of 14 patients, including one case of an undescended left lower gland at the level of the mandible and identification of a third gland on the left in another case. Sternal split was required to remove three lesions localized by T/S imaging, two beneath the aortic arch and one nestled in the aortopulmonary window in a patient who had undergone two prior procedures including a sternal split. In these three cases T/S imaging was particularly useful, because CT scans, thallium technetium scans, magnetic resonance imaging, and arteriography were not diagnostic. The outcome after operation was favorable in all 14 cases, with correction of hypercalcemia and no permanent laryngeal nerve injuries or hypocalcemia. CONCLUSIONS: We concluded that T/S imaging is more accurate than thallium technetium and CT scans in evaluation of patients with persistent hyperparathyroidism.

Adult↗
PubMed1987

Antigen-specific T cell unresponsiveness in cloned helper T cells mediated via the CD2 or CD3/Ti receptor pathways.

We have investigated the role of the CD2 protein in the negative regulation of immune function and report that similar to antigen and anti-CD3, the monoclonal anti-CD2 antibodies (T112 and T113) can induce specific unresponsiveness. Antigen and anti-CD2 tolerogenic signals both down-regulated the phenotypic expression of CD3-Ti. In contrast CD2 surface expression was up-regulated after exposure to peptide and down-regulated after anti-T112 and T113 preincubation. However, in both instances interleukin 2 receptor surface levels were increased. These phenotypic changes could only be partly explained by variations in the levels of the transcripts encoding the CD3-Ti and CD2 molecules.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1986

Observations of end-user online searching behavior over eleven years.

End-user searching of National Library of Medicine (NLM) online data bases during eleven years has been investigated through transaction logs, questionnaires, and follow-up interviews. From 1976 through 1984, pathologists and pharmacists performed 8,313 searches. Highlights of our studies are compared with a review of other end-user research. Volume of searching is directly related to the convenient placement of the terminal in the work place. Slightly fewer than half of all potential searchers actually search for themselves. Practices of pharmacists and pathologists do not differ in important ways. Nonmediated searchers feel they need answers more promptly than do those who obtain mediated searches. End-users perform very simple searches, mostly using only the AND operator. Problems with techniques are fewer and more easily solved than those with the vocabulary and content of the system. The major problems, with the most powerful capabilities of MEDLINE--subheadings and explosions--sometimes cause substantial loss of references, but in relatively few searches. One-on-one teaching is most popular, with trial-and-error the most frequent procedure used in actual learning.

Data Collection↗
PubMed1984

Magnetic resonance imaging in the diagnosis of breast disease: use of transverse relaxation times.

The ability of magnetic resonance imaging (MR) to demonstrate breast carcinoma depends upon significantly different relaxation times in benign and malignant tissues. The authors conducted an in vitro study of transverse relaxation times (T2) of 393 breast tissue samples in order to establish a range of values for normal tissue, benign lesions, and carcinoma. All T2 values were multiexponential. Benign lesions were readily distinguished from both invasive and noninvasive carcinoma in samples containing fat or a mixture of fat and fibrous tissue; however, in purely fibrous samples there was some overlap of T2 values in benign and malignant tissues. Although the data acquisition and analysis requirements involved in this in vitro study exceed the capabilities of present whole-body MR imagers, the added understanding gained through efforts of this type may aid both interpretation of current images and future developments.

Adenofibroma↗
PubMed1976

Nonmediated use of MEDLINE and TOXLINE by pathologists and pharmacists.

Pathologists and pharmacists have used terminals in their departmental areas successfully to perform searches on MEDLINE and TOXLINE, during the period from fall 1974 through August 1975; MEDLINE has been used more than TOXLINE. In the Department of Pathology at the University of Maryland Health Sciences Center, the annual rate of combined mediated and nonmediated use of MEDLINE increased from 142 search sessions to 432, over half of the identified use being by three individuals. About half of the total potential users from each group tried MEDLINE or TOXLINE at least once. Nine pathologists and seven pharmacists used MEDLINE five or more times. Five of the individuals in each group were "intensive" users, who concentrated more than half of their sessions within two months. Vocabulary experience and systems problems are touched on. Most individuals learned to use the systems from one another or in individual sessions with the authors, although a twenty-five page "minimanual" has also been used by a limited group.

Information Systems↗