Reductive dimerization of benzothiazolium salts.

Three different types of reaction products were obtained from the reduction of 2-substituted 3-methylbenzothiazolium salts using Na : Hg (1 wt%). Depending on the 2-substituents, two types of dimeric compounds were obtained: the 2-cyclohexyl-, 2-phenyl-, and 2-(p-tolyl)-substituted species are reduced to the corresponding 2,2'-bibenzo[d]thiazoles, while their 2-((p-OMe)C6H4)- and 2-((p-NMe2)C6H4)-substituted derivatives afford cis-[1,4]benzothiazino[3,2-b][1,4]benzothiazines. Furthermore, in the presence of molecular O2, new disulfide derivatives were obtained from the bibenzo[d]thiazoles. The products were obtained in a moderate to good yield, and the structures were confirmed using single-crystal X-ray diffraction. The electrochemistry and further reactivity towards different oxidants of the dimeric compounds were studied; the 2,2'-bibenzo[d]thiazoles show oxidation potentials similar to that of ferrocene and are converted back to the corresponding benzothiazolium cations by mild oxidants such as TCNQ. In contrast, the benzothiazino-benzothiazines show no oxidations in the solvent window of THF.

Left ventricular pseudoaneurysm versus aneurysm a diagnosis dilemma.

Free wall rupture of the left ventricle (LV) is a rare but life-threatening complication of acute myocardial infaction. Very rarely such rupture may be contained by the adhering pericardium creating a pseudoaneurysm. This condition warrants for an emergency surgery. Left ventricular aneurysm is the discrete thinning of the ventricular wall (<5 mm) with akinetic or dyskinetic wall motion causing an out-pouching of the ventricle. Given the propensity for pseudoaneurysms to rupture leading to cardiac tamponade, shock, and death, compared with a more benign natural history for true aneurysms, accurate diagnosis of these conditions is important. True aneurysm, usually, calls for an elective surgery. Clinically differentiating the two conditions remains a challenge. We report the case of a patient with LV pseudoaneurysm, initially diagnosed as true aneurysm at our institution. We have attempted to review the existing literature and discussed the characteristic findings of each entity.

Surgical revascularization techniques for diabetic foot.

Diabetes is an important risk factor for atherosclerosis. The diabetic foot is characterized by the presence of arteriopathy and neuropathy. The vascular damage includes non-occlusive microangiopathy and macroangiopathy. Diabetic foot wounds are responsible for 5-10% of the cases of major or minor amputations. In fact, the risk of amputation of the lower limbs is 15-20% higher in diabetic populations than in the general population. The University of Texas classification is the reference classification for diabetic wounds. It distinguishes non-ischemic wounds from ischemic wounds which are associated with a higher rate of amputation. The first principles of treatment are the control of pain of an eventual infection. When ischemia is diagnosed, restoration of pulsatile blood flow by revascularization may be considered for salvaging the limb. The treatment options are angioplasty with or without stenting and surgical bypass or hybrid procedures combining the two. Distal reconstructions with anastomosis to the leg or pedal arteries have satisfactory limb-salvage rates. Subintimal angioplasty is a more recent endovascular technique. It could be suggested for elderly patients who are believed to be unsuitable candidates for a conventional bypass or angioplasty. The current article would focus on the various revascularization procedures.