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C Beeson

Publications and source records attributed to C Beeson.

23 records · Page 2Linked to original sources
PubMed1995

Kinetics of the reactions between the invariant chain (85-99) peptide and proteins of the murine class II MHC.

The region comprising residues 83-107 of the extracytoplasmic domain of the class II MHC-associated invariant chain protein is essential for its functional interaction with MHC proteins. A nested set of peptides that encompass this region, designated the class II invariant chain-derived peptides (CLIP), bind to many MHC proteins and inhibit the binding of antigenic peptides. The kinetics of the reactions between CLIP and five different murine class II MHC proteins have been determined. Specificity of CLIP binding was confirmed by competition with antigenic peptides. Large differences in the reaction rates were observed. For example, half-times of dissociation ranged from 4.4 min to 17.5 h, a > 200-fold difference. These results demonstrate that CLIP bind to MHC heterodimers at a site that involves the polymorphic residues. These data support the hypothesis that the CLIP binding site is within the peptide binding groove. It is further suggested that these differences in kinetic stabilities of CLIP-MHC protein complexes might affect the diversity of endogenous peptides bound to class II MHC proteins.

Amino Acid Sequence↗
PubMed1995

Evaluation of CK and CK-MB in alcohol abuse subjects with recent heavy consumption.

We analyzed CK and CK-MB levels over 24 h in 15 male subjects admitted for alcohol detoxification following recent heavy ingestion. None had clinical or electrocardiographic evidence of myocardial ischemia or infarction. The mean 0-hour serum alcohol level +/- SD was 342 +/- 101 mg/dl. CK levels were measured by Kodak Ektachem and Abbott IMx assays, and CK-MB levels were determined by these assays and the Hybritech isoenzyme test. In 36% of the patients elevated 0-hour CK levels by the IMx and Ektachem assays were observed. The CK levels measured every 8 h decreased so that by 24 h CK was elevated in 1 patient by the Ektachem assay and in 2 by the IMx assay. Only 1 patient (7%) had an elevated 0-hour CK-MB value by two of the three assays, and it is unclear whether the source was cardiac or extracardiac. We conclude that: (1) elevated CK levels are common in heavy alcohol use patients without evidence of myocardial ischemia; (2) CK values over the first 24 h are decremental, not rising and falling as is typical of myocardial infarction and (3) current isoenzyme immunoassays eliminate a cardiac cause for elevated CK in most of these patients. These findings may assist in the evaluation of alcoholic patients with chest pain.

Adult↗
PubMed1994

Kinetic intermediates in the reactions between peptides and proteins of major histocompatibility complex class II.

The kinetics of the reactions between fluorescently labeled sperm whale myoglobin-(110-121) peptide and the murine major histocompatibility complex class II protein I-Ed have been analyzed. The presence in solution of both short- and long-lived protein-peptide complexes is demonstrated by the biphasic dissociation of the myoglobin peptide from I-Ed. The formation of the long-lived terminal complex is preceded by a characteristic induction phase. It is shown that the initially formed complex of the myoglobin peptide and I-Ed is a kinetic intermediate that undergoes a unimolecular reaction to form the terminal complex. Reactions between peptides and the class II proteins thus involve an intermediate structurally distinct from the terminal complex. The terminal complex presumably has a structure that is biologically active and similar to the published class II protein-peptide crystal structure.

Amino Acid Sequence↗
PubMed1988

Maternal corneal thickness during pregnancy.

We measured central corneal thickness in 89 pregnant women. It was increased 16 micron (P = .01) compared to the control eyes of 18 nongravid and 17 postpartum women. There was no significant difference (P = .79) in corneal thickness between the nongravid and postpartum groups. When comparing subjects by week of gestation, there was no trend over time in corneal thickness (analysis by linear regression). Intraocular pressure was lowered during pregnancy, but it did not correlate with corneal thickness for either the pregnant or nonpregnant group.

Adult↗