Given an abstract, generate a keyword (a noun phrase) that best describes the focus or contribution of the paper. Such keywords can be directly from the given abstract or outside it.

Q: Abstract: The T-cell antigen receptor binds antigen in association with a cell surface molecule encoded by the major histocompatibility complex (MHC). MHC restricted recognition of antigen by this receptor leads to the complex pattern of programmed gene expression that characterizes T-cell activation. The eventual understanding of human T-cell function will require the complete elucidation of the structure of the human T-cell antigen receptor. On human T cells, clonally determined, disulphide-linked alpha and beta chains of the receptor are non-covalently and stoichiometrically associated with three additional polypeptides known as the T3 complex. These receptor subunits are glycoproteins of relative molecular mass (Mr) 25,000 (25K) and 20K (gamma and delta) and a non-glycosylated 20K protein (epsilon). Our studies of murine T cells show that the mouse T-cell antigen receptor consists of at least seven distinct polypeptide chains. In addition to clonotypic alpha and beta chains, the murine complex consists of glycoproteins of 26K and 21K and endoglycosaminidase F (endo F)-insensitive polypeptides of 25K, 21K and 16K. The latter, which we have termed zeta (zeta), exists as a homodimer within the complex. The 26K component (gp26) has been shown to be the murine analogue of the human delta chain. Other cross species homologies remain to be established, however none of the described human receptor components appear similar to the murine zeta polypeptide. We report here the use of an antiserum raised against the murine zeta subunit to identify a previously unrecognized component of the human T-cell antigen receptor. This human protein is T-cell specific and biochemically similar to the murine zeta polypeptide.

A: Animal
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Q: Abstract: We evaluated the role of portasystemic shunts in the hyperkinetic circulatory state in rats with portal hypertension. Cardiac output and regional blood flow were measured by the radioactive microsphere technique in rats with portal hypertension caused by portal vein stenosis, in rats with end-to-side portacaval shunts, and in sham-operated rats. Cardiac output was significantly higher in rats with surgical shunts than in those of the two other groups and was significantly lower in sham-operated rats compared with portal hypertensive rats. Portal tributary blood flow and hepatic arterial blood flow expressed in absolute flow as well as in percentage of cardiac output were significantly increased in rats with surgical shunts compared with other groups. These blood flows were also significantly higher in portal hypertensive rats than in sham-operated animals. A significant correlation was found between cardiac output and portal tributary blood flow in rats with portal vein stenosis and in rats with surgical shunts; this correlation was absent in sham-operated rats. This study shows that the hyperkinetic circulatory state in rats with portal hypertension and a normal liver is related to the presence of portasystemic shunts but not to portal hypertension per se.

A: Animal
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Q: Abstract: Glycolic acid is the ethylene glycol (EG) metabolite that accumulates in the highest concentrations in the blood and may be the major contributing factor to the acute toxicity of EG. Serum and urine levels of glycolic acid have been found to correlate directly with clinical symptoms and mortality in poisoning cases, making it a valuable diagnostic tool. A high pressure liquid chromatographic (HPLC) method for quantitation of glycolic acid in serum was used in several cases of EG ingestion presented to the Louisiana Regional Poison Control Center. The data collected in this study support the value of glycolic acid determination for diagnosis and evaluation of patients poisoned by EG.

A:
Alcohol, Ethyl
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