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Biomedical subjects

D Chenoweth

Publications and source records attributed to D Chenoweth.

72 records · Page 4Linked to original sources
PubMed1985

Blood-membrane interaction: C3a, an indicator of biocompatibility.

An interest in hemodialysis-related patient symptomatology dating back to the beginnings of maintenance hemodialysis (HD) therapy prompted our investigations to determine the etiology of such discomfort. Since the discovery by Craddock et al (1) of the activation of the alternative complement pathway by hemodialyzer membrane, our efforts toward defining the relationship of symptoms to complement activation have been done in collaboration with the Minnesota group. Results of an earlier blinded study, (2) and continuing investigations of HD membranes provide data which support the contention that complement activation, although not necessarily etiologic in the symptoms related to dialysis, serves as an indicator of membrane compatibility. These newer data reveal C3a rises in vivo and in vitro by a Japanese processed cuprammonium membrane for dialysis to be similar to cuprophane. In vivo C3a elevation using Travenol CA-110 hemodialyzers of cellulose acetate are significantly lower and are similar to earlier results obtained by cellulose acetate of CD manufacture.

Cellulose↗
PubMed1981

Neutrophil dysfunction in sepsis. II. Evidence for the role of complement activation products in cellular deactivation.

Abnormalities in chemotactic and bactericidal activity have been identified in patients suffering from burn injury, trauma, and infection. Such abnormalities may lead to bacteremia or nosocomial infection. The mechanism for these abnormalities is unclear. We studied the role of chemotactic deactivation by complement component C5a in 47 patients with intra-abdominal infection and with disordered neutrophil function. Plasma C5a levels in such patients were elevated (102.1 +/- 8.3 versus 52.6 +/- 3.4 ng/ml for control subjects, P less than 0.01). There was a linear relationship between C5a and chemotaxis (r = 0.56, P less than 0.01). Examination of patients' neutrophils showed changes consistent with nonspecific deactivation. There were parallel losses of chemotaxis to N-formyl methionyl-leucyl-phenylalanine (FMLP) and activated serum (C5a) (r = 0.74, P less than 0.001), chemotaxis and intracellular beta-glucuronidase (r = 0.82, P less than 0.001), and C5a and FMLP chemotaxis and (r = 0.56, P less than 0.01). Receptor assays revealed specific loss of C5a binding but intact FMLP binding. Exposure of normal neutrophils to plasma from patients with depressed chemotaxis caused similar loss of C5a receptors and loss of FMLP and activated serum-induced chemotaxis at high plasma concentrations and selective loss of activated serum response at lower concentrations. These data support the concept that a major factor leading to neutrophil dysfunction during intra-abdominal infection is nonspecific chemotactic deactivation of neutrophils after in vivo exposure to high levels of chemoattractants such as C5a.

Adolescent↗
PubMed1969

Intramolecular localization of the acceptor cross-linking sites in fibrin.

Using 1-(14)C-glycine ethyl ester to titrate and label the acceptor cross-linking sites in fibrin, it was possible to localize and characterize the reactivity of these sites. In terms of sulfitolyzed chain fragments, both alpha and gamma chains were shown to act as amine-acceptors, the site in gamma being more reactive. Identification and isolation of the acceptor loci were also achieved after cyanogen bromide fragmentation. It is interesting that the "N-terminal disulfide knot" portion of fibrin does not seem to contain acceptor functions.

Animals↗
PubMedDate not supplied

Incorporating a behavioral model in health education.

Understanding the concept of behavior formation is vital in facilitating health education effectively in any setting. Traditionally, the health education process was predicated on the cognitive domain. Consequently, other behavioral influences such as attitudes and intentions were not respectively addressed. Several multidimensional behavior models have been used by health educators to favorably influence human behavior. One specific model, based on one's knowledge (beliefs), attitudes, and intentions is particularly suited for educational settings. This model can be used to assess the validity of individual beliefs, nature of attitude, specificity of intentions and associated personal health behaviors. This assessment can serve as a major motivating factor to encourage persons to identify the quality of their current lifestyle and assume personal responsibility for their welfare.

Attitude to Health↗