Screening for human mitochondrial DNA polymorphisms with denaturing gradient gel electrophoresis

A method involving denaturing gradient gel electrophoresis (DGGE) was developed to detect mitochondrial DNA (mtDNA) polymorphisms in human peripheral T-lymphocytes. DGGE analysis of 100- to 200-bp sequences of low melting temperature domains within the origin/membrane attachment site, NADH dehydrogenase subunit I, cytochrome c oxidase subunit I and two overlapping regions of the tRNA glycine/NADH dehydrogenase subunit III sequences was performed to identify sequence variants at these sites in a human B-cell line TK6 and T-cells from four individuals. A T → C transition at position 16519 in the origin/membrane attachment site in the TK6 cell line and the T-cells from one individual was found. A sequence variant resulting in a G → A transition at position 9966 in the tRNA glycine/NADH dehydrogenase III was identified in another individual. This method should be useful for the rapid screening of polymorphisms in a large number of samples. Received: 19 October 1995 / Revised: 26 March 1996     

Imaging of left main trauma during diagnostic cardiac catheterization with intravascular ultrasound

In this case report the occurrence of a catheter-induced coronary artery dissection is described. In our patient, angiography showed a mushroom-shaped exudate above the left main coronary artery. Intravascular ultrasound revealed a circular dissection with a huge false lumen connected to the true lumen by a small intimal tear. A brief review of the literature on catheter-induced coronary dissection is included. We believe that this case report provides a good illustration of the need for careful reviewing of indications for angiography. Although procedural risks are low, angiography remains an invasive diagnostic test with the potential to cause severe complications.     

Activation of morphogenesis and proliferation by low specificity chemical effectors

Activation of highly specific biochemical processes by simple chemical agents is demonstrated for morphogenesis (anlage and development of female gametophyte in cereal) and mitosis (in cell cultures and animal and plant tissues). The effects of these agents are tissue-specific. Structure--activity relationship is analyzed in this group of compounds. Thus, the phenomenon reveals the exact pathways of the influence of allelopathic and anthropogenic chemical agents on evolution of plant biocenoses.     

Biochemical and functional analysis of the YME1 gene product, an ATP and zinc-dependent mitochondrial protease from S. cerevisiae.

Inactivation of YME1 in yeast causes several distinct phenotypes: an increased rate of DNA escape from mitochondria, temperature-sensitive growth on nonfermentable carbon sources, extremely slow growth when mitochondrial DNA is completely absent from the cell, and altered morphology of the mitochondrial compartment. The protein encoded by YME1, Yme1p, contains two highly conserved sequence elements, one implicated in the binding and hydrolysis of ATP, and the second characteristic of active site residues found in neutral, zinc-dependent proteases. Both the putative ATPase and zinc-dependent protease elements are necessary for the function of Yme1p as genes having mutations in critical residues of either of these motifs are unable to suppress any of the phenotypes exhibited by yme1 deletion strains. Yme1p co-fractionates with proteins associated with the mitochondrial inner membrane, is tightly associated with this membrane, and is oriented with the bulk of the protein facing the matrix. Unassembled subunit II of cytochrome oxidase is stabilized in yme1 yeast strains. The data support a model in which Yme1p is an ATP and zinc-dependent protease associated with the matrix side of the inner mitochondrial membrane. Subunit II of cytochrome oxidase, when not assembled into a higher order complex, is a likely substrate of Yme1p.     

Initial results and long-term clinical follow-up of an amorphous hydrogenated silicon-carbide-coated stent in daily practice

The hemocompatibility and biocompatibility of a stent are determined by the physical and electrochemical properties of the stent surface. The aim of this study was to determine the feasibility, safety and efficacy of implantation of a stent coated with silicon carbide. Baseline characteristics were collected prospectively. The occurrence of cardiac adverse events and the angina score were assessed at clinical follow-up. A total of 193 Tensum stents were implanted in 174 patients. In hospital, one patient experienced stent thrombosis and in 6% of the patients a creatinine kinase elevation to 240 U/l or more occurred. Long-term follow-up was performed in 172 patients, with a mean follow-up of 454 +/- 181 days. Ninety-seven per cent were still alive, 15% had undergone target-vessel revascularization, and 2% had angiographic restenosis and were treated with medication only. Seventy-one per cent of the patients were free of anginal complaints, and 20% had anginal complaints in Canadian Cardiac Society class I or II. The Tensum coronary stent showed to be a safe and efficacious device in this study, with a high primary success rate and favorable long-term clinical followup.     

Maintenance of mitochondrial morphology is linked to maintenance of the mitochondrial genome in Saccharomyces cerevisiae

In the yeast Saccharomyces cerevisiae, certain mutant alleles of YME4, YME6, and MDM10 cause an increased rate of mitochondrial DNA migration to the nucleus, carbon-source-dependent alterations in mitochondrial morphology, and increased rates of mitochondrial DNA loss. While single mutants grow on media requiring mitochondrial respiration, any pairwise combination of these mutations causes a respiratory-deficient phenotype. This double-mutant phenotype allowed cloning of YME6, which is identical to MMM1 and encodes an outer mitochondrial membrane protein essential for maintaining normal mitochondrial morphology. Yeast strains bearing null mutations of MMM1 have altered mitochondrial morphology and a slow growth rate on all carbon sources and quantitatively lack mitochondrial DNA. Extragenic suppressors of MMM1 deletion mutants partially restore mitochondrial morphology to the wild-type state and have a corresponding increase in growth rate and mitochondrial DNA stability. A dominant suppressor also suppresses the phenotypes caused by a point mutation in MMM1, as well as by specific mutations in YME4 and MDM10.     

Phylogeny and expression of carbonic anhydrase-related proteins

Background  

Carbonic anhydrases (CAs) are found in many organisms, in which they contribute to several important biological processes. The vertebrate α-CA family consists of 16 subfamilies, three of which (VIII, X and XI) consist of acatalytic proteins. These are named carbonic anhydrase related proteins (CARPs), and their inactivity is due to absence of one or more Zn-binding histidine residues. In this study, we analyzed and evaluated the distribution of genes encoding CARPs in different organisms using bioinformatic methods, and studied their expression in mouse tissues using immunohistochemistry and real-time quantitative PCR.