Percutaneous mitral valve repair using the edge-to-edge technique in a high-risk population

Background. Percutaneous mitral valve (MV) repair using the edge-to-edge clip technique might be an alternative for patients with significant mitral regurgitation (MR) and an unacceptably high risk for operative repair or replacement. We report the short-term safety and efficacy of this new technique in a high-risk population. Methods. All consecutive high-risk patients who underwent percutaneous MV repair with the Mitraclip^® between January and August 2009 were included. All complications related to the procedure were reported. Transthoracic echocardiography for MR grading and right ventricular systolic pressure (RVSP) measurement were performed before, and at three and 30 days after the procedure. Differences in NYHA functional class and quality of life (QoL) index were reported. Results. Nine patients were enrolled (78% male, age 75.9±9.0 years, logistic EuroSCORE 33.8±9.0%). One patient developed inguinal bleeding. In one patient partial clip detachment occurred, a second clip was placed successfully. The MR grade before repair was ≥3 in 100%, one month after repair a reduction in MR grade to ≤2 was present in 78% (p=0.001). RVSP decreased from 43.9±12.1 to 31.6±11.7 mmHg (p=0.009), NYHA functional class improved from median 3 (range 3 to 4) to 2 (range 1 to 4) (p=0.04), and QoL index improved from 62.9±16.3 to 49.9±30.7 (p=0.12). Conclusion. In high-risk patients, transcatheter MV repair seems to be safe and a reduction in MR can be achieved in most patients, resulting in a short-term improvement of functional capacity and QoL. (Neth Heart J 2010;18:437-43.)     

Rupture of right coronary sinus of Valsalva aneurysm into right ventricle

A sinus of Valsalva aneurysm is a rare cardiac anomaly that may be congenital or acquired; a coexisting cardiac lesion might be present. If the aneurysm ruptures, it causes acute symptoms of dyspnoea. Echocardiography and cardiac magnetic resonance imaging are useful for diagnosis. The treatment of choice is surgery. We present a case of a patient with acute onset of symptoms due to a ruptured sinus of Valsalva aneurysm. (Neth Heart J 2010;18:209-11)     

Occurrence of antibiotic-resistant bacteria and endotoxin associated with the land application of biosolids

The purpose of this study was to determine the prevalence of antibiotic-resistant bacteria and endotoxin in soil after land application of biosolids. Soil was collected over a 15 month period following land application of biosolids, and antibiotic resistance was ascertained using clinically relevant antibiotic concentrations. Ampicillin, cephalothin, ciprofloxacin, and tetracycline resistance were all monitored separately for any changes throughout the 15 month period. Endotoxin soil concentrations were monitored using commercially available endotoxin analysis reagents. Overall, land application of biosolids did not increase the percentage of antibiotic-resistant culturable bacteria above background soil levels. Likewise, land application of biosolids did not significantly increase the concentration of endotoxin in soil. This study determined and established a baseline understanding of the overall effect that land application of biosolids had on the land-applied field with respect to antibiotic-resistant bacterial and endotoxin soil densities.     

Draft genome sequence of Leucobacter chromiiresistens, an extremely chromium-tolerant strain

Here we present the draft genome of Leucobacter chromiiresistens. This is the first genome sequence of an organism belonging to the genus Leucobacter. L. chromiiresistens was sequenced due to its capability to tolerate up to 300 mM Cr(VI) in the medium, which is so far a unique feature for microorganisms.     

Genome sequence of the facultative anaerobic arsenite-oxidizing and nitrate-reducing bacterium Acidovorax sp. strain NO1

Acidovorax sp. strain NO1, isolated from gold mine soil, was shown to be a facultative anaerobic arsenite-oxidizing and nitrate-reducing bacterium. The reported draft genome predicts the presence of genes involved in arsenic metabolism, nitrate reduction, phosphate transport, and multiple metal resistances and indicates putative horizontal gene transfer events.     

The ChrA homologue from a sulfur-regulated gene cluster in cyanobacterial plasmid pANL confers chromate resistance

The cyanobacterium Synechococcus elongatus strain PCC 7942 possesses pANL, a plasmid rich in genes related to sulfur metabolism. One of these genes, srpC, encodes the SrpC protein, a homologue of the CHR chromate ion transporter superfamily. The srpC gene was cloned and expressed in Escherichia coli and its role in relation to sulfate and chromate was analyzed. srpC was unable to complement the growth of an E. coli cysA sulfate uptake mutant when sulfate was utilized as a sole sulfur source, suggesting that SrpC is not a sulfate transporter. Expression of srpC in E. coli conferred chromate resistance and caused diminished chromate uptake. These results suggest that the S. elongatus SrpC protein functions as a transporter that extrudes chromate ions from the cell’s cytoplasm, and further demonstrate the close relationship between sulfate and chromate metabolism in this organism.     

The Pco proteins are involved in periplasmic copper handling in Escherichia coli

The interactions between the plasmid-borne copper resistance determinant, pco, and the main copper export system in Escherichia coli have been investigated and no direct interaction has been found. The PcoE and PcoC proteins are periplasmic and PcoC binds one Cu ion per protein molecule. PcoA is also periplasmic and can substitute for the chromosomally encoded CueO protein. The pco determinant is proposed to exert its effect through periplasmic handling of excess copper ions and to increase the level of resistance to copper ions above that conferred by copA alone.