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With a new immunoenzymometric assay we measured human glycogen phosphorylase isoenzyme BB (GPBB) in 116 healthy individuals, 14 patients with stable angina, 107 nontraumatic chest pain patients on admission to the emergency department [45 acute myocardial infarction (AMI), 49 unstable angina, 13 other diseases], and in serial samples from 41 AMI patients. GPBB was compared with creatine kinase (CK), CKMB mass, myoglobin, and cardiac troponin T. Receiver-operating characteristic plots demonstrated the significantly greater (P < or = 0.012) discriminatory power of GPBB to detect acute ischemic coronary syndromes compared with all other tested markers. GPBB was the most sensitive marker for detection of AMI during the first 4 h after onset of chest pain, and only GPBB was increased above the upper reference limit (7 micrograms/L) on admission in patients who had unstable angina at rest and reversible ST-T alterations. This and the high early sensitivity of GPBB are most likely explained by its function as a key enzyme of glycogenolysis.

OBJECTIVE--To determine whether transient ST-T alterations in patients with unstable angina are associated with an increase in plasma glycogen phosphorylase BB concentrations on admission to hospital. DESIGN--Prospective screening of patients with unstable angina for markers of myocardial cell damage. SETTING--Accident and emergency department of university hospital. PATIENTS--48 consecutive patients admitted for angina pectoris (18 with transient ST-T alterations). None of the patients had acute myocardial infarction according to standard criteria. MAIN OUTCOME MEASURES--Creatine kinase and creatine kinase MB activities, creatine kinase MB mass concentration, and myoglobin, cardiac troponin T, and glycogen phosphorylase BB concentrations on admission. RESULTS--All variables except for creatine kinase and creatine kinase MB activities were significantly higher on admission in patients with unstable angina and transient ST-T alterations than in patients without. However, glycogen phosphorylase BB concentration was the only marker that was significantly (p = 0.0001) increased above its discriminator value in most patients (16). In the 18 patients with transient ST-T alterations creatine kinase MB mass concentration and troponin T and myoglobin concentrations were significantly (p = 0.0001) less commonly increased on admission (in five, three, and two patients, respectively). CONCLUSIONS--The early release of glycogen phosphorylase BB may help to identify high risk patients with unstable angina even on admission to an emergency department. Glycogen phosphorylase BB concentrations could help to guide decisions about patient management.

A recently published method for purification of a new inhibitor of growth of mammary cells in vitro from bovine mammary gland has been modified to yield several hundred micrograms of inhibitor per kg of glandular tissue. The inhibitory effect exerted by this preparation to Ehrlich ascites mammary carcinoma cells fulfilled all biological criteria of specificity established earlier for preparations obtained by other means, the most important being that the inhibitory effect is abolished by the epidermal growth factor and insulin. The preparation is shown to consist mainly of a protein of 13 kDa which appears to be not glycosylated. An antiserum raised in mice against the inhibitor is demonstrated to be specific for the 13 kDa bovine mammary gland protein. Neutralization of the inhibitory activity by the specific antiserum strongly supports the view that the 13 kDa protein is indeed the carrier of inhibitory activity. First data on tissue distribution obtained with an enzyme-linked immunosorbent assay revealed a high concentration of the anti-inhibitor-antiserum-reactive antigen in bovine lactating but not in non-lactating mammary gland tissue and in milk fat globule membranes. Some reactivity was also found in bovine lung. These data are interpreted with respect to a possible physiological significance of the growth inhibitor.

Leberextrakt hat in Gegenwart von L-Glutamat eine hemmende Wirkung auf die anaerobe Glykolyse der Ehrlich-Mäuseascites-Carcinomzelle. Die hemmende Wirkung des Leberextraktes wird auf die Wirkung von Glutamat-Pyruvat-Transaminase zurückgeführt. Das bei der Glykolyse intermediär entstehende Pyruvat wird durch die Transaminierungs-Reaktion abgefangen und somit der Dehydrierung von DPNH entzogen. Die sinkende Konzentration an DPN ⨁ hat eine Hemmung der Triosephosphatdehydrierung zur Folge. Die Glykolysehemmung durch GPT ist aufhebbar durch Sauerstoff sowie durch Zugabe von Pyruvat, von DPN ⨁, von α-Ketoglutarat und von L-Alanin.

Es wird ein Verfahren zur Darstellung hoch gereinigter Glutamat-Pyruvat-Transaminase beschrieben. Die anaerobe Glykolyse in Ehrlich-Mäuseascites-Carcinomzellen wird durch hoch gereinigte GPT ebenso gehemmt wie durch Leberextrakt, wenn die gleiche Konzentration an GPT-Einheiten eingesetzt wird.

Nucleolar ‘80-S’ and ‘40-S’ preribosomes (containining 45-S and 21-S pre-rRNA, respectively), as well as cytoplasmic ribosomes, were isolated from Friend erythroleukemia cells. The presence of structural ribosomal proteins in the isolated particles was studied by using antisera against individual rat liver small ribosomal subunit proteins. The analysis is based on the established crossreactivity between rat and mouse ribosomes [F. Noll and H. Bielka (1970) Mol. Gen. Genet. 106, 106–113]. The identification of the proteins was achieved by two independent immunological techniques: the passive haemagglutination test and the enzyme immunoassay of electrophoretically fractionated proteins, blotted on nitrocellulose. All 17 proteins tested are present in cytoplasmic ribosomes. A large number of proteins (S3a, S6, S7, S8, S11, S13, S14, S18, S20, S23/24 and S25) are present in the ‘80-S’ pre-ribosome. Only two proteins (S3 and S21) are added during the formation of the ‘40-S’ preribosome in the nucleolus. Four proteins (S2, S19, S26 and S29) are added at later, possibly extranucleolar, stages of ribosome formation. The results obtained provide evidence for the sequential addition of proteins during the formation of the small ribosomal subunit in Friend erythroleukemia cells.