Proton-induced X-ray emission analysis of atherosclerotic plaques of the carotid bifurcation

The trace elements of both calcified atherosclerotic plaques and plaque-free vessel walls of the carotid bifurcation from 31 autopsies were investigated using the proton-induced X-ray emission (PIXE) method. The trace elements studied were phosphorus (P), calcium (Ca), chrome (Cr), iron (Fe), copper (Cu), zinc (Zn), lead (Pb), selenium (Se), bromine (Br), strontium (Sr), and rubidium (Rb). All samples contained Fe and Zn. Mercury (Hg) was not detected in any of the samples studied. All plaque-free samples contained Cu and almost all Br and Ca, none Sr. All calcified atherosclerotic plaques contained Ca and almost all Br and Sr. The relative levels of Ca were higher in the calcified plaques than in the plaque-free vessel walls. The relative value of Ca in calcified and uncalcified samples was greatest in the group who had died because of cardiovascular disorders and smallest in the group who had died from other causes. There was a strong positive correlation between the Ca and Sr of the plaque samples and between the P and Br of the plaque-free samples.     

A new homeobox-leucine zipper gene from Arabidopsis thaliana

We have isolated a homeobox-containing gene from Arabidopsis thaliana using a degenerate oligonucleotide probe corresponding to the most conserved region of the homeodomain. This strategy has been used previously to isolate homeobox-containing genes from Caenorhabditis, and recently from A. thaliana. The Arabidopsis genes have an unusual structure in that they have a leucine zipper motif adjacent to the carboxy terminal region of the homeo domain, a feature not found in homeobox-containing genes isolated from animals. We report the isolation and primary structure of a new member of this Arabidopsis homeobox-leucine zipper gene family. This new member has the homeodomain and leucine-zipper motif similar to the two genes previously identified, but differs from these genes in the part corresponding to the carboxy terminus of the polypeptide, as well as in size and isoelectric point of the protein.     

Influence of medium composition on penicillin V production in a stirred tank reactor.

Penicillin production with a high-producing strain Penicillium chrysogenum was investigated under well-controlled conditions in a stirred tank reactor with complex media containing lard oil and lactose on the one hand, and lactose on the other hand. With lard oil, cell growth and product formation rates were higher, and the production time was shorter by 40 h than without lard oil. On account of the longer production time without lard oil, the amount of beta-lactam compounds was higher (29.93 g l-1), but the mole fraction of the decomposed products (penicilloic acid and penilloic acid) was larger (0.282) than the amount of penicillin V (23.25 g l-1) and the decomposed mole fraction (0.0747) with lard oil. The final product concentrations were about the same (20.86 g l-1 or 35,462 IU ml-1 with lard oil, and 20.43 g l-1 or 34510 IU ml-1 without lard oil). The mole fractions of the by-product (p-OH-penicillin V) were 0.0365 and 0.066. The substitution of lard oil with lactose is possible without a considerable reduction of process performance.     

Oligomerization reactions of ribonucleotides: The reaction of the 5′-phosphorimidazolide of nucleosides on montmorillonite and other minerals

The reaction of ImpA in the presence of Na⁺-montmorillonite 22A or Na⁺-Volclay in aqueous, pH 8 solution gives a 50–60% yield of dimers and trimers (pA)₂ and (pA)₃. The ratio of 3,5-phosphodiester bond formation is twice as great as 2,5-bond formation. The reaction requires the presence of Mg²⁺ and is inhibited by 0.4 M imidazole. N-methylimidazole enhances the rate of the reaction but does not cause major changes in yield or product composition. Higher yields were obtained when Li⁺- or Ca²⁺-montmorillonites were used in place of Na⁺-montmorillonite. Little or no phosphodiester bond formation was observed with Mg²⁺- or Al³⁺-montmorillonite. Montmorillonites other than 22A and Volclay exhibited little or no catalysis. In addition, little or no catalysis was exhibited in ferrugenous smectite, nontronite, allophane, imogolite or sepiolite. Oligomers were also formed by the reaction of ImpG, 2-methylImpG, ImpC and ImpU in the presence of Na⁺-montmorillonite. The pyrimidine nucleotides gave significantly lower yields of oligomers.     

Release of substance P-like immunoreactive material from the stomach of the rainbow trout

Summary The release of substance P-like immunoreactive material (SPLI) from the vascularly perfused stomach of the rainbow trout, Oncorhynchus mykiss, was studied. In most cases, SPLI was detected in the collected vascular perfusate during experimental resting conditions. Distensions of the stomach, accomplished by a water-filled intragastric balloon, produced an initial rapid relaxation of the stomach, followed by a slow further relaxation and a stimulation of contractile activity. The amount of SPLI in the vascular perfusate was significantly elevated during the distension period. Tetrodotoxin had no effect on the response to distension or on the release of SPLI during distension, indicating release from tetrodotoxin-insensitive neurons or endocrine cells. The results suggest that a substance P-like peptide may be involved in the contractile response and/or in the maintenance of muscular tone during gastric distensions in the rainbow trout. Infusion of capsaicin had no effect on the release of SPLI. However, capsaicin caused an increase in vascular flow, an effect that could be repeated on a second infusion of capsaicin, indicating that the action may not be specific to sensory neurons.Abbreviations 5-HT 5-Hydroxytryptamine - RIA radioimmunoassay - SP substance P - SPLI substance P-like immunoreactive material - TTX tetrodotoxin     

Blue native electrophoresis for isolation of membrane protein complexes in enzymatically active form.

A discontinuous electrophoretic system for the isolation of membrane proteins from acrylamide gels has been developed using equipment for sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Coomassie dyes were introduced to induce a charge shift on the proteins and aminocaproic acid served to improve solubilization of membrane proteins. Solubilized mitochondria or extracts of heart muscle tissue, lymphoblasts, yeast, and bacteria were applied to the gels. From cells containing mitochondria, all the multiprotein complexes of the oxidative phosphorylation system were separated within one gel. The complexes were resolved into the individual polypeptides by second-dimension Tricine-SDS-PAGE or extracted without SDS for functional studies. The recovery of all respiratory chain complexes was almost quantitative. The percentage recovery of functional activity depended on the respective protein complex studied and was zero for some complexes, but almost quantitative for others. The system is especially useful for small scale purposes, e.g., separation of radioactively labeled membrane proteins, N-terminal protein sequencing, preparation of proteins for immunization, and diagnostic studies of inborn neuromuscular diseases.     

Molecular cloning of the human histamine H2 receptor.

We utilized the technique of polymerase chain reaction with oligonucleotide primers based upon the nucleotide sequence of the canine H2 histamine receptor gene which we recently isolated to clone its human homologue. Transfection of a construct of this gene in Colo-320 DM cells led to the expression of a receptor that bound to [methyl-3H] tiotidine and was linked to 3',5'cyclic adenosine monophosphate (cAMP) generation in response to histamine. Both cAMP generation and [methyl-3H] tiotidine binding were inhibited with the H2 histamine receptor selective antagonist cimetidine but not diphenhydramine or thioperamide which are, respectively, H1 and H3 histamine receptor antagonists. These data confirm that we have successfully cloned a novel gene encoding the human H2 histamine receptor.     

Genetic and biochemical characterization of a new chymotrypsin isozyme of the house mouse,CTRA-1

Genetic variation of a codominantly inherited pancreas protease, designated CTRA-1, was discovered in the house mouse by isoelectric focusing in polyacrylamide gels. Phenotype CTRA-1A was found in MOLH/Fre and in the majority of common laboratory mouse strains. Phenotype CTRA-1B was found in PWD/Ph. It was characterized by the absence of a corresponding protease band. A third phenotype, CTRA-1C, was observed in IS/Cam and a fourth phenotype, CTRA-1D, was detected in SEG/1. CTRA-1 was found only in the pancreas and may represent the A form of chymotrypsin. The enzyme was shown to be controlled by the presumed structural locus Ctra-1 located on chromosome 8. From two backcross series, including a total of 274 animals, the gene order (Es-1, Es-9)-3.9 +/- 1.7%-Got-2-3.9 +/- 1.7%-(Es-2, Es-7, Es-23)-0.7 +/- 0.5%- Ctra-1-6.3 +/- 2.2%-Prt-2 was established.