Effect of solvents on the photophysical properties of substituted imidazonaphthyridine derivatives.

The absorption and fluorescence characteristics of three substituted imidazonaphthyridine derivatives are studied in a series of organic solvents. The variation of Stokes shift with the polarity parameter of the solvent is studied and the excited state dipole moment of these derivatives is higher than the ground state dipole moment. The fluorescence lifetime profile shows single exponential decay in all the solvents. The fluorescence quantum yield, radiative and non-radiative rate constants are also calculated and these parameters show much variation in the change in substitution of these derivatives.

Two-dimensional echocardiographic observation of dehiscence of mitral plication annuloplasty suture.

Echocardiographic findings of dehiscent suture from mitral plication annuloplasty have not been described. We herein describe transthoracic two-dimensional echocardiographic findings of an abnormal linear echo stretching across the mitral annulus in the left atrium in a 69-year-old male. This abnormal linear echo was confirmed to be a dehiscent plication suture at surgery.

Creatine kinase MB elevation in paralytic shellfish poisoning.

An outbreak of paralytic shellfish poisoning occurred in southern Taiwan, affecting 116 persons who had consumed purple clams. Two victims died within four hours. Gonyautoxins were identified as causative toxins. During the outbreak, five patients with paralytic shellfish poisoning were seen in our hospital. All recovered following supportive treatments. Serum creatine kinase concentration was elevated in three of the five patients. The levels of the enzyme did not seem to correlate with the severity of poisoning. The most significant finding was the previously unreported observation of elevation of the creatine kinase MB level. In all four patients who had creatine kinase MB value determined, it was elevated.

Perforated aneurysm of the anterior mitral valve. A Doppler and two-dimensional echocardiographic report.

Antemortem diagnosis of a perforated MV aneurysm by Doppler echocardiography, as well as two-dimensional echocardiography (2-DE), has not been reported. Herein we present such a case.

Echocardiographic findings of mobile atrial hepatocellular carcinoma. Report of five cases.

Hepatoma with cardiac metastasis is difficult to diagnose antemortem. Herein we describe five cases of hepatoma with intracardiac metastasis detected with two-dimensional echocardiography (2DE). The clinical presentations include cardiac murmur, syncope, and chest pain. The 2DE demonstrated a right atrial (RA) mass in each case and the presence of tumor echoes in the inferior vena cava connecting with the RA mass in four. In three cases the cardiac tumor was removed, whereas the other two patients agreed only to liver biopsy, which confirmed the diagnosis. This paper emphasizes the practical utility of 2DE for early detection of intracardiac hepatoma and also describes the clinicopathologic correlation of such a disease entity.

Moving right atrial mass associated with hepatoma. Two cases detected by echocardiography.

Hepatoma with right atrial (RA) metastasis is rare, and to our knowledge, the echocardiographic description of a RA mass associated with hepatoma has never been described. Herein we report two cases of hepatoma, whose two-dimensional echocardiograms demonstrated a RA mass protruding into right ventricle during diastole, mimicking RA myxoma. However, in contrast to RA myxoma, these RA masses could be traced to the inferior venae cavae, which were dilated and filled with tumor echoes. Since prompt diagnosis and removal of these RA masses might prevent sudden cardiac death, we advocate performing echocardiographic examination in patients with hepatoma, who have cardiac symptoms or signs.

Measurements of ionization constants and partition coefficients of quanazole prodrugs.

A series of guanazole prodrugs, which are less water soluble than the parent compound and have relatively higher molecular weights, was recently synthesized, and their antineoplastic activities were measured in vitro. In present work, the ionization constants and partition coefficients of these compounds were measured for the first time. In contrast to guanazole, which is a weak base, guanazole prodrugs have been shown to be weak to moderate acids due to the electronic effects of the acyl group and the heterocyclic ring. Possible tautomeric and resonance structures are presented to account for the pKa values observed. Both the inductive and resonance effects of the substituent are important in determining the values of the ionization constant. The preparation of the prodrugs not only altered the lipophilicity but also drastically changed the acid-base property of the parent compound. The observed true partition coefficient values in most guanazole prodrugs studied were higher than those calculated from the pi-constants. Under highly ionized conditions, the small amount of water in the octanol layer has a significant effect in trapping a substantial amount of the ionized species in the octanol layer and gives rise to a higher log P value than expected. Under nonionized conditions, intramolecular hydrogen bonding plays an important factor in electron delocalization and reduction of hydrogen bonding with water molecules, causing the nonionized species of the guanazole prodrugs to be more lipophilic than expected.