Nocardicin A, a new monocyclic beta-lactam antibiotic II. Structure determination of nocardicins A and B

The structures of nocardicins A and B, novel monocyclic beta-lactam antibiotics produced by a strain of Nocardia, have been established as 1 and 2, respectively, on the basis of spectroscopic and chemical evidence. They are the first examples of monocyclic beta-lactam antibiotics possessing relatively high antimicrobial activity, and are stereochemically and biologically related to penicillins and cephalosporins.

Two molecular forms of thymidine kinase in the cytosol of regenerating rat liver

Two forms (Peak A and Peak B) of thymidine kinase [EC 2.7.1.75] from regenerating rat liver cytosol were resolved and partially purified by Deae-cellulose chromatography. Both fractions were identical with respect to their substrate requirement, pH optima, metal requirements, and molecular weight, as judged by their sedimentation in sucrose density gradient centrifugation. Peak B differed from Peak A in heat sensitivity, inhibition by dCTP and Km for thymidine and ATP. Peak B enzyme was the only enzyme found in normal adult liver and Peak A enzyme was the form increasing predominantly in regenerating liver.

Comparison of ontogenetic brain growth in marine and coastal dolphins

In young postnatal individuals, brain growth proceeds at a much faster rate in the high seas dolphin Stenella than in the coastal waters form Pontoporia, and the encephalization is much higher in the former than in the latter. In prenatal Stenella, brain growth is also very rapid. These results agree with indices of brain progression estimated for several families (Platinistidae, Delphinidae, Delphinapteridae, Phocoenidae). The possibility that the difference is related to more demanding conditions of life in marine than in coastal or inland environments is discussed.

Daunorubicin, cytosine arabinoside, 6-mercaptopurine riboside, and prednisolone (DCMP) combination chemotherapy for acute myelogenous leukemia in adults

Thirty-seven adults with acute myelogenous leukemia (AML) were treated with a combination of daunorubicin, cytosine arabinoside, 6-mercaptopurine riboside, and prednisolone (DCMP) for remission induction. Twenty-three of 37 patients (62.2%) achieved complete remission, three, partial remission and 11, failure. Patients with prior therapy responded as well as patients without it. The median survival time of the patients who received DCMP for their initial remission induction therapy was 10.3 months and that of the patients who obtained complete remission was 17 months. Complete remission occurred in 21 out of 28 patients (75%) less than 40 years old but in only two out of nine patients (22.2%) more than 40 years old. The most common toxic effects were severe myelosuppression and liver function abnormalities. DCMP therapy is an effective remission induction chemotherapy for adults with AML.