Nuclear migration, nucleokinesis and lissencephaly

During the past 20 years, biologists have become used to finding that proteins first identified in simple, genetically manipulable eukaryotic organisms are conserved in higher eukaryotes. This article draws attention to the similarity between NUDF protein, which is required for nuclear migration in the filamentous fungus Aspergillus nidulans, and a mammalian homologue, LIS1, whose malfunction causes lissencephaly, a neuronal migration disease. The authors suggest that there might be an underlying similarity of mechanism between nuclear migration in the fungus and neuronal migration in the brain.     

The effects of anemia on heme synthesis parameters during lead exposure

The effects of anemia during lead exposures were studied using an infant baboon animal model. When the hemoglobin concentration was reduced to less than 70% of normal, a marked blood lead increase was observed and the free erythrocyte porphyrin value, aminolevulinic acid dehydratase activity and reticulocyte counts increased. Special emphasis should be placed on nutritional effects in lead exposures.     

Human gamma-interferon expression in the mammary gland of transgenic mice

Transgenic mice carrying a hybrid gene consisting of ovine beta-lactoglobulin gene sequences and human gamma-interferon (hIFN-g) cDNA were produced. hIFN-g expression in the mammary gland of two lactating transgenic founder females was found. The concentration of active hIFN-g in the milk was estimated as being ca. 1800 IU/ml. The hIFN-g ability to express in the mammary gland was found in the progeny of transgenic founder male.     

Volume of reaction by the Archibald ultracentrifuge method (lobster hemocyanin)

Samples of lobster hemocyanin (Homarus americanus) under conditions of reversible reaction between whole (25 S) and half (17 S) molecules have been subjected to accurately known nitrogen pressures in analytical ultracentrifuge cells. A modified pressurization chamber of the type developed by Schumaker and colleagues has been constructed for this purpose. The molecular weight was then determined at the top (liquid-gas) meniscus, by means of the Archibald method. The logarithmic dependence upon pressure of the derived equilibrium constant then gave directly the volume of reaction. Experiments were performed in veronal-citrate buffers at pH 8, where the molar volume of formation of whole (dodecameric) molecules from half molecules appears to be negative, and at pH 8.46 in veronal-citrate buffer in the presence of 0.003 molar free calcium ion, where the molar volume of formation was estimated to be + 390 cm3/mole. In glycine-sodium hydroxide buffer at pH 9.6 containing 0.0047 molar free calcium, the molar volume of formation of whole molecules was estimated to be +120 +/- 70 cm3, corresponding to an estimated difference in partial specific volume between whole molecules and half molecules of only 1.3 (10)-4cm3/gram. The correctness of the sign of this value in glycine buffer has been verified by pressure-jump light-scattering experiments.