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Biomedical subjects

C L Walker

Publications and source records attributed to C L Walker.

At least 55 records · Page 3Linked to original sources
PubMed1995

Colocalization of the rat homolog of the von Hippel Lindau (Vhl) gene and the plasma membrane Ca++ transporting ATPase isoform 2 (Atp2b2) gene to rat chromosome bands 4q41.3-->42.1.

Using fluorescence in situ hybridization, we localized the rat homolog of the von Hippel-Lindau gene (Vhl) to rat chromosome band 4q41.3-->q42.1. We also mapped the gene encoding the plasma membrane Ca(++)-transporting ATPase isoform 2(Atp2b2) to the same chromosome subregion. These two genes together with Raf1 appear to be members of a large syntenic gene cluster that maps to human chromosome bands 3p25-->p26, mouse chromosome bands 6 C3-->E, and rat chromosome bands 4q41-->q42. Cytogenetic analysis of NRK 52E cells derived from immortalized normal rat kidney epithelial cells revealed an inverted duplication of the region containing this gene cluster.

Animals↗
PubMed1994

Characterization of cell lines derived from formaldehyde-induced nasal tumors in rats.

Cell lines derived from formaldehyde-induced nasal tumors in Fischer 344 rats were established. All of the lines were found to be epithelial and aneuploid and to express keratin, transforming growth factor-alpha, and epidermal growth factor receptor transcripts. Two of four lines were tumorigenic upon injection into nude mice, and these lines also contained point mutations in the p53 suppressor gene. The data indicate that these lines possess characteristics that make them a valuable tool for the study of chemically induced respiratory tract carcinogenesis.

Animals↗
PubMed1993

A cross-sectional analysis of hospital profitability.

This study used logit regression to discriminate between profitable and non-profitable hospitals. The specified model worked best for voluntary hospitals, and the classification results were consistently higher for profitable hospitals than for non-profitable hospitals. Only one financial variable, the operating margin, was consistently significant in each regression equation. The results challenged the "general consensus" that operating efficiency is uniform across control categories. Teaching status was found to have a significant and positive effect, but only for voluntary hospitals. Lastly, the results indicate that uncompensated care is a major concern for voluntary hospitals. These findings raise the question of whether reimbursement rates under PPS should incorporate local factors. They also indicate that hospital management style does not and will not model business operations. As such, hospital managers may be unable to dramatically change a hospital's level of profitability.

Efficiency, Organizational↗
PubMed1993

Hospital control and decision making: a financial perspective.

A study was conducted to test the hypothesis that there are no significant differences in financial decision making among hospitals in different control categories. Significant differences were found in financial decision making in for-profit hospitals, voluntary hospitals with religious affiliations, and secular voluntary hospitals. Managers of for-profit hospitals base their financial decisions more on the need to achieve operating efficiency and profitability than do managers of voluntary hospitals. Managers of voluntary hospitals with religious affiliations and secular voluntary hospitals give about the same emphasis to efficiency. Surprisingly, however, managers of voluntary hospitals with religious affiliations emphasize profitability and financial leverage more than managers of secular voluntary hospitals do.

Decision Making, Organizational↗
PubMed1993

Sibling bereavement and grief responses.

A child's death can have a profound and lasting effect on surviving siblings. Early researchers and clinicians have suggested that siblings were at risk for serious psychopathology. However, in later studies, researchers found that although the grief process was emotionally difficult, siblings may have grown and matured as a result of living through the loss. The purpose of this report was to review and summarize the literature on sibling bereavement and grief as well as to present nursing implications.

Adaptation, Psychological↗
PubMed1992

Arthroscopic fixation of osteochondritis dissecans. Outpatient treatment for condylar defects.

According to a 1990 study, 88% of the patients assessed their postoperative result as excellent or good after two years of follow up. One disadvantage to this repair is the need for a second arthroscopy for compression screw removal; however, this allows the surgeon an opportunity to assess healing. Surgeons are continuing to advance arthroscopic surgery by using supplemental bone grafts, with or without compression screw fixation. Arthroscopic compression screw fixation of osteochondritis dissecans is a progressive alternative for patients who may otherwise have been candidates for an open-knee arthrotomy.

Ambulatory Surgical Procedures↗
PubMed1992

Hereditary renal cell carcinoma in the Eker rat: a rodent familial cancer syndrome.

A rodent model of hereditary cancer in which a single gene mutation predisposes rats to bilateral multicentric renal cell carcinoma (RCC) is described. This rat hereditary cancer syndrome shares certain similarities with von Hippel-Lindau disease (VHLD). In addition to the early development of renal epithelial tumors with morphologic similarity to human RCC, rats which bear the RCC gene are predisposed to the development of secondary primary cancers later in life. Splenic vascular proliferative lesions, including hemangiosarcoma, were seen in 23% of 14-month-old rats of both sexes that had renal tumors. At fourteen months of age, 62% of female rats with renal cell tumors had sarcomas of the lower reproductive tract of probable smooth muscle origin. Non-carrier siblings of affected animals did not have renal, reproductive, or splenic neoplasia. The finding of a specific constellation of familial neoplasms, including multicentric bilateral renal cell carcinoma, in this autosomal dominant disorder of rats suggests that this syndrome is analogous to human VHLD. In addition to its usefulness for studies of the biochemical and molecular mechanisms of renal carcinogenesis, this animal model will provide a unique tool to investigate how cancer susceptibility genes interact with environmental risk factors such as chemical carcinogens.

Animals↗
PubMed1991

The Barr body is a looped X chromosome formed by telomere association.

We examined Barr bodies formed by isodicentric human X chromosomes in cultured human cells and in mouse-human hybrids using confocal microscopy and DNA probes for centromere and subtelomere regions. At interphase, the two ends of these chromosomes are only a micron apart, indicating that these inactive X chromosomes are in a nonlinear configuration. Additional studies of normal X chromosomes reveal the same telomere association for the inactive X but not for the active X chromosome. This nonlinear configuration is maintained during mitosis and in a murine environment.

Animals↗
PubMed1991

Hypogammaglobulinemia associated with cytomegalovirus pneumonia.

Transient but profound hypogammaglobulinemia occurred during cytomegalovirus (CMV) pneumonia in a patient who developed striking declines in number of T lymphocytes. A 66-year-old, female, human immunodeficiency virus-negative patient requiring long-term hemodialysis had normal serum immunoglobulin concentrations before the onset of CMV pneumonia (IgG, 1070-1470 mg/dl; IgA, 94-102 mg/dl; IgM, 30-48 mg/dl). During the pneumonia episode, serum immunoglobulin concentrations were profoundly reduced (IgG, 440 mg/dl; IgA, 40 mg/dl; IgM, 25 mg/dl). Total lymphocytes declined from 3048/mm3 to 212/mm3 with reductions in CD4+CD45- lymphocytes (inducers of B cells) to 9% (nl, 24%-32%) and CD4+CD45+ lymphocytes (inducers of suppressor T cells) to 4% (nl, 14%-22%). CD8 lymphocytes were reduced to 5% (nl, 19%-31%). As the pneumonia resolved, serum immunoglobulin concentrations returned to normal. This is one of the few reported instances of CMV infection apparently causing hypogammaglobulinemia.

Agammaglobulinemia↗
PubMed1990

Problems of instrument selection.

There are many problems in selecting appropriate instruments to use in research with children. Four problem areas have been outlined: instrument sensitivity, data source (adult report or observation v child self-report), adaptability to different ages and developmental levels, and the context or setting.

Child↗
PubMed1990

Erythema multiforme and Stevens-Johnson syndrome. Descriptive and therapeutic controversy.

Diagnosis and particularly the management of erythema multiforme and Stevens-Johnson syndrome are controversial in medical textbooks and thus in individual cases. In these diseases, fatalities may result from various causes, including secondary infection or visceral organ damage to lung, liver, or kidneys. We present a series of 13 cases managed by one group of physicians which demonstrates the controversy in certain cases, and we review the controversy in the medical literature. Corticosteroid therapy used in this series was considered beneficial in every case by the managing physician and lifesaving in some cases. There were no fatalities in this series. Although the summation may be considered as our opinion only, the frequently suggested "controlled trial of corticosteroid therapy" can probably never be done for ethical reasons, and series such as this will have to establish the standard of therapy.

Erythema Multiforme↗
PubMed1989

T cell function and expression are dramatically altered in T cell receptor V gamma 1.1J gamma 4C gamma 4 transgenic mice.

We have characterized transgenic mice carrying a functional T cell receptor (TCR) C gamma 4 (V gamma 1.1J gamma 4C gamma 4) gene. Results indicate that active transcription of the C gamma 4 transgene can influence expression of the endogenous C gamma 4, C gamma 1 (V gamma 3-, V gamma 4-, V gamma 2-, or V gamma 5J gamma 1C gamma 1) and C gamma 2 (V gamma 1.2J gamma 2C gamma 2) genes, while the ultimate expression of other TCR delta, alpha, and beta chain genes, as well as the adult T cell response, are relatively unaltered. Cells expressing transgenic C gamma 4 and endogenous delta TCR transcripts can migrate to the skin as dendritic epithelial cells (DEC) even though C gamma 4 cells are rarely, if at all, found in the skin. Transgenic and control mice were compared at 2 weeks, 6-7 weeks, and older. At 2 weeks, the thymus of transgenic mice, particularly the medulla, was much larger than control. Moreover, peripheral lymphoid tissues of younger mice were markedly (as much as 100-fold) more immunoreactive (both Con A response and alloreactivity). These differences, although persistent, became smaller in older mice. The data suggest that transgene expression has a major effect on T cell development and reactivity.

Animals↗