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C L Walker

Publications and source records attributed to C L Walker.

At least 73 records · Page 4Linked to original sources
PubMed1989

Diphenylmethane diisocyanate hypersensitivity pneumonitis: a serologic evaluation.

We describe the clinical and immunologic evaluation of a steel plant maintenance supervisor who had clinical symptoms consistent with hypersensitivity pneumonitis. No antigen was obvious but after a thorough occupational history and review of the industrial hygiene data, the most likely antigen appeared to be diphenylmethane diisocyanate. Precipitating antibodies were not detected in the worker's serum; however, significant antibody levels of IgG specific for diphenylmethane diisocyanate-human serum albumin were detected by other immunoassays. This case highlights the importance of a thorough occupational history and an aggressive laboratory immunologic evaluation in identifying the offending agent in a worker with hypersensitivity pneumonitis. Hypersensitivity pneumonitis due to an inhaled reactive chemical may be present without precipitins demonstrated in vitro due to the nature of the haptenized chemical protein conjugate or the concentration of IgG antibody.

Alveolitis, Extrinsic Allergic↗
PubMed1989

Baker's asthma: report of an unusual case.

Using immunologic techniques recently available, we report the evaluation of baker's asthma due to wheat flour and demonstrate the usefulness of these techniques in occupational asthma. The diagnosis of baker's asthma was very important in this case, as even a trial of avoidance of work exposure was not possible because of the social and economic factors involved. A commercial wheat extract was obtained and the wheat flour actually used at the work site was extracted. Prick skin testing with each of these extracts resulted in positive wheal and flare responses. Enzyme linked immunosorbent assay and inhibition assays were performed to assess the worker's antibody response to wheat flour and wheat extracts. Significant specific IgE and IgG levels to the wheat flour and wheat extracts were detected in the worker's serum. Because of unique psychosocial and educational factors, this worker was unable to change occupations. Even with respiratory protection, she continued to be symptomatic. She is currently controlled on bronchodilators and inhaled steroids.

Antibody Specificity↗
PubMed1987

T cell receptor variable gene usage in a specific cytotoxic T cell response. Primary structure of the antigen-MHC receptor of four hapten-specific cytotoxic T cell clones.

The primary structure of the alpha and beta chains of the T cell antigen receptor in four cytotoxic T cell clones specific for N-iodoacetyl-sulfonic-naphthyl-ethylene-diamine (AED)-haptenated target cells displaying a particular class I MHC molecule has been determined. Two of the T cell clones, 8/10-2 and 5/10-20K, recognize AED-modified targets in association with H-2Kb, while the other two clones 5/10-20D and C9 react with AED-modified cells in the context of H-2Db. Comparison of the nucleotide sequences of both the alpha and beta chain cDNAs and their deduced protein sequences indicates that a specific variable gene segment was not used to recognize the hapten and/or class I gene products. Furthermore, there does not appear to be any conserved amino acid residues used in the AED-specific response other than the framework amino acids. However, when the two clones 8/10-2 and 5/10-20D were compared, a striking similarity was seen in the J segments. These two clones that recognize AED in the context of different MHC epitopes used identical J alpha (J alpha 810) and J beta (J beta 2.6) gene segments. C9, specific for AED-Db, shared identical V beta (V beta 6) and J beta gene segments (J beta 1.1) as those of a cytotoxic T cell that recognizes allogeneic targets expressing Db. These data indicate that a simple rule governing the usage of the variable regions of either the alpha or beta T cell receptor (TcR) genes in the recognition of antigen and MHC gene products cannot be formulated. However, subtle similarities can be detected in some situations between the primary structures of the TcR and the targets they recognize.

Base Sequence↗
PubMed1987

In vitro analysis of multistage carcinogenesis.

Several key events in the multistep process of neoplastic transformation of rat tracheal epithelium (RTE) are described. Whether tracheal epithelium is exposed in vivo to carcinogenic agents or whether primary tracheal epithelial cells are exposed in vitro to carcinogens, initiated stem cells can be detected soon after the exposure by their ability to grow under selective conditions in culture. These initiated stem cells differ fundamentally from normal stem cells in their response to factors normally constraining proliferation and self-renewal. Thus, disruption of inhibitory control mechanisms of stem cell replication appears to be the first event in RTE cell transformation. While the probability of self-renewal (PSR) is clearly increased in initiated stem cells, most of the descendants derived from such stem cells differentiate and become terminal and do not express transformed characteristics. Progression from the first to the second stage of RTE cell transformation, the stage of the immortal growth variant (IGV), is characterized by loss of responsiveness to the growth-restraining effects of retinoic acid. In the third stage of neoplastic transformation, the stage during which neoplastic growth variants (NGV) appear, a growth factor receptor gene is inappropriately expressed in some of the transformants. Thus, it appears that loss of growth-restraining mechanisms may be an early event, and activation of a growth stimulatory mechanism a late event, in neoplastic transformation of RTE cells.

Animals↗
PubMed1987

Are hospital managers served by current models for predicting financial distress?

During the last decade there have been major competitive changes in the health care industry. This more dynamic environment has forced hospitals to emphasize efficiency in their operations. One consequence is an increased concern with financial condition and, subsequently, with the ability to predict financial distress. This paper synthesizes several important studies on firm failure in the field of finance and compares them with recent studies of hospital survival. The inescapable conclusion is that most models predicting hospital financial distress are restricted, flawed, or both. As result, one must question whether such applications effectively serve hospital managers or public policy makers.

Data Collection↗
PubMed1986

T cell-specific gamma genes in C57BL/10 mice. Sequence and expression of new constant and variable region genes.

The T cell-specific gamma genes in C57BL/10 (B10) mice have been analyzed. Based on the cDNA sequences of these genes from antigen-specific MHC-restricted cytotoxic T cells, we found that the repertoire of these genes is not as limited as previously postulated (8). T cells from the B10 mice express an identical copy of V gamma J gamma C gamma (V gamma 10.8A-JC gamma 10.5) transcript previously found in T cells of BALB/c mice. In addition, a potentially functional mRNA using V gamma 10.8B and newly identified J gamma and C gamma gene segments were found. The new J gamma C gamma (JC gamma 10.8) is located 5' to the inverted V gamma 10.8B in the germline DNA of both B10 and BALB/c mice. This new C gamma is only 77 and 66% homologous to the C gamma 10.5 at the nucleotide and deduced protein sequences, respectively, thus making it a potential isotype of the C gamma genes reported previously. The V gamma 5.7, J gamma 2.3 gene segments and pseudogene C gamma 7.5 found in the germline DNA of BALB/c mice are absent in B10 mice. The loss of this gamma chain pseudogene in the B10 mouse strain, and the retention of all potentially functional V gamma, J gamma, and C gamma genes with highly conserved coding sequences supports the importance of these genes.

Amino Acid Sequence↗
PubMed1984

The national diet.

Explore the source record for details and available documents.

Coronary Disease↗
PubMed1983

A short dietary questionnaire for use in an epidemiological survey: comparison with weighed dietary records.

Nutrient data from a short dietary questionnaire designed for self-administration in epidemiological studies of ischaemic heart disease were compared with those from 7-day weighed dietary records obtained 2 to 6 weeks later in a sample of 119 men from the general population. For the major nutrients correlation coefficients of between 0.27 (total carbohydrate) and 0.75 (alcohol) were obtained all of which were statistically significant. In the case of alcohol over 90 per cent of the weekly intake was consumed outside the home in standard measures. In the case of other nutrients improvement in the precision of the questionnaire estimates may be obtained by direct estimates of portion sizes.

Alcohol Drinking↗
PubMed1982

Determinants of high density lipoprotein and total cholesterol in women.

An epidemiological study was carried out among a random sample of women aged 18 to 69 years to examine possible determinants of plasma high density lipoprotein and total cholesterol (HDL-C and T-C). In a multiple regression analysis consumption of alcohol, fatty fish, and parental longevity showed positive associations with HDL-C, which were statistically significant. Smoking habit, sucrose consumption, and a family history of ischaemic heart disease showed significantly negative associations. In contrast, T-C was associated significantly only with age and Quetelet's index of body mass. Five variables having significant associations with HDL-C explained only 8% of the total variance; in the case of T-C 17% of the variance was explained by age and body mass.

Adolescent↗
PubMedDate not supplied

APON's first 25 years: a lighter look from the past presidents.

This report uses an oral history methodology to look back at 25 years of the Association of Pediatric Oncology Nurses (APON) from the perspective of the past presidents. The different roles and responsibilities of the president and how they have evolved over the years are identified. Amusing, behind-the-scenes anecdotes from different presidential terms are revealed.

Humans↗