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1.  Involvement of an Alkane Hydroxylase System of Gordonia sp. Strain SoCg in Degradation of Solid n-Alkanes▿  
Enzymes involved in oxidation of long-chain n-alkanes are still not well known, especially those in Gram-positive bacteria. This work describes the alkane degradation system of the n-alkane degrader actinobacterium Gordonia sp. strain SoCg, which is able to grow on n-alkanes from dodecane (C12) to hexatriacontane (C36) as the sole C source. SoCg harbors in its chromosome a single alk locus carrying six open reading frames (ORFs), which shows 78 to 79% identity with the alkane hydroxylase (AH)-encoding systems of other alkane-degrading actinobacteria. Quantitative reverse transcription-PCR showed that the genes encoding AlkB (alkane 1-monooxygenase), RubA3 (rubredoxin), RubA4 (rubredoxin), and RubB (rubredoxin reductase) were induced by both n-hexadecane and n-triacontane, which were chosen as representative long-chain liquid and solid n-alkane molecules, respectively. Biotransformation of n-hexadecane into the corresponding 1-hexadecanol was detected by solid-phase microextraction coupled with gas chromatography-mass spectrometry (SPME/GC-MS) analysis. The Gordonia SoCg alkB was heterologously expressed in Escherichia coli BL21 and in Streptomyces coelicolor M145, and both hosts acquired the ability to transform n-hexadecane into 1-hexadecanol, but the corresponding long-chain alcohol was never detected on n-triacontane. However, the recombinant S. coelicolor M145-AH, expressing the Gordonia alkB gene, was able to grow on n-triacontane as the sole C source. A SoCg alkB disruption mutant that is completely unable to grow on n-triacontane was obtained, demonstrating the role of an AlkB-type AH system in degradation of solid n-alkanes.
doi:10.1128/AEM.02180-10
PMCID: PMC3067205  PMID: 21183636
2.  Primary Coronary Embolism as an Unusual Manifestation of Nonbacterial Thrombotic Endocarditis in a Patient with Gastric Cancer 
Nonbacterial thrombotic endocarditis (NBTE) is a rare clinical condition characterized by the presence of sterile vegetations on valvular leaflets Gross and Friedberg (1936). The most frequent cause of NBTE is antiphospholipid syndrome Hughson and et al. (1993); malignancy, through an intrinsic condition of hypercoagulability, is the second most common cause Thomas (2001). Systemic thromboembolic complications are frequently associated with this condition, but coronary embolism is not common. We report the case of a patient with NBTE secondary to gastric adenocarcinoma with clinical symptoms of coronary and systemic emboli.
doi:10.4061/2010/319732
PMCID: PMC2896834  PMID: 20614001
3.  Diffuse Supravalvular Aortic Stenosis: Surgical Repair in Adulthood 
We present the case of a 54-year-old woman in which a diffuse congenital supravalvular aortic stenosis (SVAS) was associated with a severe aortic valve incompetence and heavy calcification of the aortic annulus. Repair consisted in resection of the ascending aorta, patch augmentation of the hypoplastic aortic root and annulus, placement of a 20 mm Dacron tubular graft (Vascutek, Renfrewshire, UK) and aortic valve replacement with a mechanical prosthesis (Sorin, Turin, Italy). Follow-up echocardiography demonstrated normal prosthetic valve function and a postoperative three-dimensional computed tomographic scan showed a normal shape of the reconstructed ascending aorta.
doi:10.4061/2009/976190
PMCID: PMC2796460  PMID: 20049320

Results 1-3 (3)