Lysozyme is a component of human vascular elastic fibers

Lysozyme has been demonstrated in the elastic fibers of normal human arteries and veins by the peroxidase-antiperoxidase technique. Preliminary trypsinization of paraffin sections is necessary to unmask the immunoreactive lysozyme.     

RNA polymerase II C-terminal repeat influences response to transcriptional enhancer signals

The large subunit of RNA polymerase II contains a highly conserved and essential heptapeptide repeat (Pro-Thr-Ser-Pro-Ser-Tyr-Ser) at its carboxy terminus. Saccharomyces cerevisiae cells are inviable if their RNA polymerase II large subunit genes encode fewer than 10 complete heptapeptide repeats; if they encode 10 to 12 complete repeats cells are temperature-sensitive and cold-sensitive, but 13 or more complete repeats will allow wild-type growth at all temperatures. Cells containing C-terminal domains (CTDs) of 10 to 12 complete repeats are also inositol auxotrophs. The phenotypes associated with these CTD mutations are not a consequence of an instability of the large subunit; rather, they seem to reflect a functional deficiency of the mutant enzyme. We show here that partial deletion mutations in RNA polymerase II CTD affect the ability of the enzyme to respond to signals from upstream activating sequences in a subset of promoters in yeast. The number of heptapeptide repeats required for maximal response to signals from these sequences differs from one upstream activating sequence to another. One of the upstream elements that is sensitive to truncations of the CTD is the 17-base-pair site bound by the GAL4 transactivating factor.     

Improved business planning through an awareness of political cycles

Can business planning be improved if more attention is paid to underlying political cycles? This paper compares practitioner and researcher perspectives on this issue. While practioners stand to gain useful insights from a careful examination of past political cycles, these insights may be disconfirmed by rigorous tests carried out by researchers. In this paper we isolate and examine five hypotheses from the literature on the political-economic cycle.     

The mechanism of tetrodotoxin on the in situ acetylcholinesterase in the vagal heart system ofRana pipiens

Zusammenfassung Am isolierten Vagus-Herzen vonRana pipiens wird die Wirkung der Vagusreizung gemessen: Konzentrationen unter 4×10^–10 g/ml Tetrodotoxin erhöhen die vagale Reizungswirkung, nicht aber die Herzkontraktionen.     

Antifungal properties of taxol and various analogues

The antimitotic agent taxol was tested for toxicity towards fungi from different taxonomic groups and found to be particularly active against oomycete fungi. In germinating zoospore cysts of the oomycetePhytophthora capsici the mechanism of action of taxol was shown to involve inhibition of mitosis, presumably resulting from an effect on microtubules. Various taxol analogues with deleted A-ring C-13 side chain substituents were tested for toxicity towardsP. capsici andAphanomyces cochlioides to provide insight into structural features required for activity. The importance of the side chain was shown by the much lower activity as compared to taxol of analogues lacking all or part of the side chain. The effect of stereochemistry at the C-2 position on fungitoxicity towards oomycetes was similar to that reported previously on mammalian microtubule assembly.     

Optimum ordering policy for preventive age replacement

Most of the spare ordering policies treated up to now have assumed that preventive and corrective replacement costs are equal, which implies in essential that there is no significant need for preventive replacement. This paper presents an ordering policy for preventive age replacement with minimal repair. Introducing the replacement, repair, inventory holding and shortage costs, the expected cost rate is derived. A procedure to determine jointly the ordering time for a spare and the preventive replacement time for the operating unit so as to minimize the expected cost rate is proposed. To explain the ordering policy and the optimization procedure, a numerical example is also included.     

Somatic cell nuclear transfer

Cloning by nuclear transfer from adult somatic cells is a remarkable demonstration of developmental plasticity. When a nucleus is placed in oocyte cytoplasm, the changes in chromatin structure that govern differentiation can be reversed, and the nucleus can be made to control development to term.