Search

Bevacizumab, a monoclonal antibody against vascular endothelial growth factor, may be associated with arterial embolisms. We herein report a case of acute myocardial infarction caused by coronary embolism during combination chemotherapy with mFOLFOX-6 and bevacizumab in a patient with metastatic colon cancer. Thromboembolism occurred only in the distal right posterolateral branch without stenotic lesions or plaque rupture in the proximal branch of the right coronary artery. Sole thromboaspiration was successfully performed; the final angiogram demonstrated no stenosis in the right coronary artery. Bevacizumab may be associated with acute coronary syndrome in patients with coronary risk factors, despite no significant coronary narrowing.

Bioprosthetic aortic valves have limited durability. We herein report sudden progression of structural valve deterioration (SVD) and a successful case of emergency transcatheter aortic valve (TAV) implantation for acute decompensated heart failure (ADHF) caused by SVD. A 79-year-old man who had undergone a Bentall operation 11 years prior was diagnosed with ADHF due to suddenly progressive SVD. Emergency TAV implantation in the surgical bioprosthetic valve was selected based on the surgical risk. Ours and previous case reports suggest that SVD can progress suddenly, even after months of stability, and that emergency TAV implantation is effective.

Acute type A aortic dissection is a potentially fatal disease, and emergency surgery should be considered when it is diagnosed. We herein report two cases of retrograde type A aortic dissection with intramural hematoma, followed by re-dissection, rupture, and cardiac tamponade. The diagnoses in these cases had to be made carefully, as the false lumen of the ascending aorta was sometimes unclear on contrast-enhanced computed tomography.

Spontaneous coronary artery dissection (SCAD) is rare, but it frequently presents as acute myocardial infarction. It is frequently fatal and most cases are diagnosed at autopsy. We herein present the case of a 65-year-old woman with ST-elevation and myocardial infarction due to SCAD. Optical coherence tomography (OCT) helped us to confirm the diagnosis. The information on the intravascular morphology provided by OCT imaging is much more detailed in comparison to that provided by coronary angiography (CAG) and intravascular ultrasound (IVUS).

A case of delayed occurrence of C3 vertebra anterior subluxation diagnosed 10 days after surgery for epidural hematoma is herein described. A 56-year-old man underwent surgery for right epidural hematoma. No spinal fracture was identified on the cervical–spinal computed tomography (CT) on arrival. The patient developed neck pain after the craniotomy, and cervical magnetic resonance imaging 5 days postoperatively revealed a disruption of the C3–C4 posterior ligament complex. The patient was conservatively treated with immobilization. Cervical CT 10 days postoperatively revealed C3 vertebra anterior subluxation. Posterior fixation surgery was performed 21 days after admission, and the postoperative course was uneventful. This case suggests that awareness of delayed occurrence of cervical dislocation after traumatic intracranial hemorrhage should be increased among neurosurgeons.

A series of lithium selenocarboxylates 2 were synthesized in good yields by the direct reaction of acyl chlorides with lithium selenide. The salts 2 were soluble in ether and tetrahydrofuran and readily reacted with alkyl iodides to give the corresponding Se-alkyl esters in quantitative yields.

The reaction of lithium alkyneselenolates generated from lithium alkynides and selenium powder with a variety of thiols afforded selenothioic acid S-alkyl esters in moderate to high yields. The product yields were highly dependent on the substituents of the starting acetylenes. The formation of unstable S-aryl ester was confirmed by the enolization followed by alkylation.

Acylselenenyl halides 2(X = Cl, Br) have been generated from RC(O)SeAsPh21 and N-halogenosuccinimide, and the chlorides 2(X = Cl) have been treated with enol silyl ethers to give Se-β-oxoalkyl Selenoesters 5 in good yields.

Rubidium and cesium selenocarboxylates (2 and 3) were found to be synthesized in good to high yields from the reaction of O-trimethylsilyl selenocarboxylates with rubidium and cesium fluorides. The spectroscopic properties of 2 and 3 are also given.

Aromatic diselenoic acid Se-methyl esters 1 react with amines at 0°C in tetrahydrofuran (THF) to yield selenoamides in moderate to good yields. The reaction course is highly dependent on the steric requirements of both starting materials. In the reactions of the ester 1a with 2-methylpiperidine and of the ester 1b with piperidine, the starting materials disappear within 1 hour with the liberation of black selenium, but the corresponding selenoamides are not produced. These results may be ascribed to the steric congestion caused by the formation of the selenoamide group from the tetrahedral intermediate 15. X-ray crystal structure analyses of the selenoamides 3 and 9 have been performed. The bond length of C(Se)N is shorter than a carbon nitrogen single bond. On the other hand, the CSe bond is longer than that of the ordinary carbon-selenium double bond. These results are indicative of the efficient delocalization of the electrons of nitrogen to the carbon–selenium double bond. The double bond character between the carbon attached to selenium and the nitrogen is also supported by the nitrogen atom showing sp2 character. When a methyl group is introduced at the meta position of the aromatic ring, the deviation of the aromatic ring from the plane involving the carbon–selenium double bond and nitrogen atom becomes substantially large, perhaps due to the steric bulkiness of the selenium atom.

Sodium 2 and potassium selenocarbamates 3 were found to be synthesized in moderate to good yields by the reaction of carbamoyl chlorides with sodium and potassium selenides. The salts 2 and 3 reacted with alkyl halides and organo-germanium, -tin, and -lead chlorides to give the corresponding esters 7–9 in good yields.

A series of rubidium and cesium tellurocarboxylates (2 and 3) were synthesized from the reaction of O-trimethylsilyl tellurocarboxylates (1) with rubidium and cesium fluorides in moderate isolated yields and characterized by 1H, 13C, and 125Te NMR spectroscopy and X-ray diffraction. The carbon–oxygen distance [1.235(6) A] of the tellurocarboxyl group of crystalline cesium 2-methoxybenzenecarbotelluroate (3f) showed a typical value of the carbon–oxygen double bond. The crystal packing of 3f shows the possibility of an interaction between the cesium cation and the aromatic ring carbon. The thio- and selenocarboxyl groups of the corresponding sulfur and selenium isologues (4 and 5) also indicate a double bond [1.231(4) and 1.226(5) A] between the carbon and oxygen, respectively. The salts (2 and 3) readily react with iodomethane to afford the corresponding Te-methyl tellurocarboxylates in good yields. The reaction between 3 and tetramethylammonium chloride was found to give a novel quaternary ammonium salt (...

Allylations of selenothioic acid S-alkyl esters with allylic bromides in the presence of Et3N in THF took place selectively at the α-position of selenocarbonyl group to give allylated products with high regio- and stereo-selectivity.

The reaction of lithium alkyneselenolates generated from terminal acetylenes with thiols gave rise to lithium eneselenolates with high stereoselectivity. The trapping with alkyl halides afforded ketene selenothioacetals, whereas the trapping with allylic bromides yielded γ,δ-unsaturated selenothioesters via seleno-Claisen rearrangement.

Thiocarboxylic acids, such as selenocarboxylic acids, exist predominantly in the thioxo form (RCSOH, thion acid) in polar solvents such as tetrahydrofuran (THF) at temperatures below −50 °C. Tellurocarboxylic acids (5) were observed for the first time by acidolysis of the corresponding cesium tellurocarboxylates with hydrogen chloride. The telluroic acids (6) exist predominantly in the telluroxo form (RCTeOH, telluron acid) in THF at temperatures below −70 °C. Telluron acids were reddish to blue violet for the aliphatics (R = alkyl) and dark green for the aromatics (R = aryl) and reacted with aryl isocyanates at −70 °C to give crystalline acyl carbamoyl tellurides in good yields.

α,α-Disubstituted selenoamides are synthesized from terminal acetylenes, selenium, amines and allylic bromides in good to high yields; their reduction with LiAlH4 affords alkenylamines quantitatively.

Reductive cyclization of γ,δ-unsaturated selenothioic acid S-esters with NaBH4 or LiAlH4 proceeds viaδ,Iµ-unsaturated selenols to afford tetrahydroselenophenes in good to high yields.

Novel water-soluble diaryl tellurides, alkyl aryl tellurides, and dialkyl tellurides carrying sulfopropyl groups were prepared and found to possess potent peroxide decomposing and chain-breaking antioxidative capacity. The dilithium, disodium, dipotassium, and bis-tetramethylammonium salts of bis(4-hydroxyphenyl) telluride (4) were treated with 2.3 equiv of 1,3-propanesultone in aqueous tert-butyl alcohol to give the corresponding salts 5 of bis-O-sulfopropylated diaryl telluride. A variety of diaryl ditellurides were reduced with sodium borohydride in ethanol. Upon addition of propanesultone to the resulting sodium arenetellurolates, the corresponding 3-aryltellurenylpropanesulfonic acid sodium salts 8 were precipitated. Diphenyl diselenide and dibutyl ditelluride reacted similarly to afford the sodium salts of 3-benzeneselenenylpropanesulfonic acid (9) and 4-telluraoctanesulfonic acid (10), respectively. The glutathione peroxidase-like activity of the water-soluble compounds was assessed at pH = 7.4 by ...

A new derivative of 4,5,9,10-tetrahydro-1,4-ethanobenz[b]quinolizine (2) has been designed as a prodrug for its quinolizinium cation (1) that is a potent antagonist of the TCP-binding site of NMDA receptors at the open state. The 11C-labeled 2 showed high accumulation of radioactivity in the brain in an in vivo biodistribution study. The speculation of 2 as a prodrug of 1 has been proven by the fact that 1 was observed in a high ratio to 2 in an analysis by RP-HPLC of the brain homogenates.

Selenocarboxylic acids [RC(=O)SeH] were found to readily react with aryl, acyl, and arenesulfonyl isocyanates to give the corresponding acyl carbamoyl selenides 3 [RC(=O)SeC(=O)NHR′, R′ = aryl, C6H5CO, and 4-MeC6H4SO2] in good yields. Their tautomers [RC(=O)SeC(=NR′)OH] were also detected by 1H, 13C, and 77Se NMR spectroscopies. The structure of 3 [R = 2,6-(MeO)2C6H3, R′ = 4-MeC6H4] was characterized by X-ray crystallography, which showed that this molecule is stabilized by an intramolecular hydrogen bond between the carbonyl oxygen and the NH hydrogen to form a planar six-membered ring and by nonbonded interaction of the ortho methoxy oxygen with the carbonyl oxygen or the selenium atoms. 4-Methoxybenzoyl and 4-methoxythiobenzoyl N-(4-methylphenyl)carbamoyl sulfides (4 and 5) were shown by X-ray crystallography to similarly have a planar intramolecular six-membered ring formed by a hydrogen bond between the carbonyl oxygen or thiocarbonyl sulfur and NH hydrogen atoms. The tautomers [RC(=E)SC(=NR′)OH; E = O or S] of 4 and 5 also were detected spectroscopically. The reactions of 3h (R = 4-MeOC6H4, R′ = Ph) with sodium methoxide and p-toluidine gave sodium selenocarboxylate and the corresponding amides and urea as main products, respectively. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:250–258, 2001

The reaction of selenothioic acid S -alkyl esters with electron deficient alkynes was carried out under reflux in toluene to give cyclic selenides in good yields. On the contrary, the similar reaction in MeOH or CH 2 Cl 2 with Et 3 N afforded acyclic divinyl selenides in good to high yields.

The reaction of bis(acyl) tellurides with primary or secondary amines or potassium ethanolate yielded the corresponding tellurocarboxylic acid salts, which are readily oxidized with iodine or benzenesulfonyl chloride to afford novel bis(acyl) ditellurides.