Treatment of advanced atrioventricular block with beta-adrenergic blockade therapy.

A 26-year old woman, who experienced syncope associated with advanced AV block, was referred for further evaluation. Electrophysiological study showed normal SA and AV node physiology. Syncope associated with advanced AV block on the electrocardiogram was induced by head-up tilt test.

Thyroxine enhancement and the role of reactive oxygen species in tadpole tail apoptosis.

Our objective is to clarify the role of reactive oxygen species (ROS) in the atrophying tail of anuran tadpoles (tail apoptosis). Changes in catalase, superoxide dismutase (SOD) and caspase activity, genomic DNA, and nitric oxide (NO) generation were investigated biochemically using Rana japonica tadpole tails undergoing regression during thyroid hormone enhancement. DNA fragmentation and ladder formation with concomitant shortening of tadpole tail were induced by DL-thyroxine (T4) in culture medium.

Evidence for heteromorphic sex chromosomes in males of Rana tagoi and Rana sakuraii in Nishitama district of Tokyo (Anura: Ranidae).

Karyotypes of the Tago brown frog Rana tagoi and stream Tago brown frog Rana sakuraii from a mountain region in the Nishitama district in Tokyo were examined by conventional Giemsa staining, C-banding and late replication (LR)-banding. Chromosome number was 2n = 26 in all cases. The 26 chromosomes consisted of five (1-5) pairs of large chromosomes and eight (6-13) pairs of small chromosomes.

A study on the effects of endogenous nitric oxide on coronary blood flow, myocardial oxygen extraction and cardiac contractility.

The purpose of the present study was to clarify how endogenous nitric oxide (NO) affects cardiac contractility and myocardial oxygen consumption (MVO2) in vivo. alpha-Chloralose-anesthetized dogs (n = 18) were instrumented to perform continuous and simultaneous measurements of coronary blood flow (CBF), anterior interventricular vein oxygen saturation (with the use of a fiberoptic catheter), aortic pressure, left ventricular pressure, and left ventricular volume. CBF, myocardial oxygen extraction (O2-extract), MVO2, the relationship between CBF and O2-extract during direct vasodilation induced by intracoronary papaverine (0.

Pirmenol hydrochloride-induced QT prolongation and T wave inversion on electrocardiogram during treatment for symptomatic atrial fibrillation.

Pirmenol hydrochloride is a new orally effective, long-acting antiarrhythmic agent currently used in patients with supraventricular and ventricular tachyarrhythmias. We report on a 56-year-old female who exhibited drug refractory paroxysmal atrial fibrillation, in which marked prolongation of the QT interval and T wave inversion on electrocardiogram was demonstrated reproducibly shortly after the administration of oral pirmenol therapy. The plasma concentration of pirmenol was at a subtherapeutic level and the lymphocyte stimulation test was positive in this patient.

Fusion variations of pancreatic ducts in patients with anomalous arrangement of pancreaticobiliary ductal system.

Fusion variations of the pancreatic ducts were studied to elucidate the significance of such variations. We classified structural fusion anomalies of the main and accessory pancreatic ducts on endoscopic retrograde cholangio-pancreatography (ERCP) in 37 patients with anomalous arrangement of the pancreaticobiliary ductal system (AAPB). The fusion variations of the pancreatic ducts were classified into five types: common, ansa pancreatica, branch fusion, looped, and separated.

Nitric oxide modulates cardiac contractility and oxygen consumption without changing contractile efficiency.

Nitric oxide (NO) affects myocardial contractility and myocardial oxygen consumption (MVO2) in vitro. In alpha-chloralose-anesthetized dogs instrumented for the measurements of left ventricular (LV) pressure, LV volume using a conductance catheter, coronary blood flow, and coronary venous oxygen saturation (ScvO2) using a fiber-optic catheter, LV end-systolic pressure-volume relationships (ESPVR) and the relationship between MVO2 and LV pressure-volume area (PVA) were analyzed before and after intravenous infusions of the NO synthase inhibitor NG-monomethyl-L-arginine acetate (L-NMMA; 5 mg/kg, 8 dogs) and the NO substrate L-arginine (600 mg/kg, 7 dogs). L-NMMA increased the slope of the ESPVR (Emax) (P < 0.

Inhibitor and temperature effect on catalase in the liver of adult diploid and haploid Rana rugosa.

The authors succeeded in raising a single mature haploid Rana rugosa female to the age of 2 years from an egg artificially fertilized with ultraviolet-irradiated sperm. In order to discover why this particular haploid individual should survive so long, hydrogen peroxide detoxifying catalase in the liver of this individual and age-matched diploids was examined and compared for total activity, temperature stability, and chemical inhibition. Total activity was found to be significantly higher in the haploid frog than in the diploids, suggesting that this particular haploid had a unique system for hydrogen peroxide detoxification which protected the liver against cell death, preventing hepatic failure, and leading to a prolonged survival.

Alpha1-syntrophin has distinct binding sites for actin and calmodulin.

Overlay and co-sedimentation assays using recombinant alpha1-syntrophin proteins revealed that two regions of alpha1-syntrophin, i.e. aa 274-315 and 449-505, contain high-affinity binding sites for F-actin (Kd 0.

Is dobutamine-induced sinus node deceleration a marker of significant stenosis of the right coronary artery?

Study Objectives: Sinus node deceleration during exercise is a highly specific marker for significant stenosis of the right coronary artery. Prior studies of dobutamine-induced sinus node deceleration have contained relatively few patients, and the purpose of this study was to determine if sinus node deceleration is an accurate marker of right coronary artery disease in a much larger study population.

Design: Dobutamine stress echocardiography was performed in a cohort of patients, and submaximal exercise testing and coronary angiography were performed in most of the patients.

Comparison of catalase in diploid and haploid Rana rugosa using heat and chemical inactivation techniques.

The present study examines differences in the hydrogen peroxide (H2O2) detoxifying enzyme, catalase, found in the tails and livers of diploid and haploid Rana rugosa. Investigative techniques include measurement of catalase activity and tests for temperature stability and chemical inhibition. Catalase from the tails of pre-climactic (stage XXIII) haploids was found to be over three times as H2O2 destructive as catalase from similar tails of diploids.

Bidirectional signaling between sarcoglycans and the integrin adhesion system in cultured L6 myocytes.

The rat L6 skeletal muscle cell line was used to study expression of the dystrophin-containing glycoprotein complex and its interaction with the integrin system involved in the cell-matrix adhesion reaction. A complex of dystrophin and its associated proteins was fully expressed in L6 myotubes, from which anti-dystrophin or anti-alpha-sarcoglycan co-precipitated integrin alpha 5 beta 1 and other focal adhesion-associated proteins vinculin, talin, paxillin, and focal adhesion kinase. Immunostaining and confocal microscopy revealed that dystrophin, alpha-sarcoglycan, integrin alpha 5 beta 1, and vinculin exhibited overlapping distribution in the sarcolemma, especially at focal adhesion-like, spotty structures.

The developmental origin of primordial germ cells and the transmission of the donor-derived gametes in mixed-sex germline chimeras to the offspring in the chicken.

A novel system has been developed to determine the origin and development of primordial germ cells (PGCs) in avian embryos directly. Approximately 700 cells were removed from the center of the area pellucida, the outer of the area pellucida, and the area opaca of the stage X blastoderm (Eyal-Giladi and Kochav, 1976; Dev Biol 49:321-337). When the cells were removed from the center of the area pellucida, the mean number of circulating PGCs per 1 microliter of blood was significantly decreased to 13 (P < 0.

Evidence for two successive pericentric inversions in sex lampbrush chromosomes of Rana rugosa (Anura: Ranidae).

The objective of this study was to clarify the course of inversions by which a ZW sex chromosome dimorphism has become established in Rana rugosa. Fortunately, R. rugosa preserves three different forms of sex chromosomes in the several isolated populations.

Acute myocardial infarction in a patient during dobutamine stress echocardiography.

We report the case of a patient who developed an acute anteroseptal and inferior myocardial infarction during dobutamine stress echocardiography. The proposed mechanism for this event is discussed based on results obtained during emergency coronary angioplasty and subsequent clinical findings.

Differentiation of female chicken primordial germ cells into spermatozoa in male gonads.

In avian species, the developmental fate of different-sex germ cells in the gonads is unclear. The present study attempted to confirm whether genetically female germ cells can differentiate into spermatozoa in male gonads using male germline chimeric chickens produced by the transfer of primordial germ cells (PGC), and employing molecular biological methods. As a result of Southern hybridization, specific sequences of the W chromosome (the female specific sex chromosome in birds) were detected in the genomic DNA extracted from one out of four male germline chimeric chickens.

mRNA expression and cDNA sequences of beta- and gamma-sarcoglycans are normal in cardiomyopathic hamster heart.

In BIO14.6 cardiomyopathic hamster heart, the dystrophin-glycoprotein complex is disrupted and sarcoglycans are greatly reduced in abundance. We examined whether the gene expression of beta- and gamma-sarcoglycans is indeed defective in this hamster.

Do reactive oxygen species underlie the mechanism of apoptosis in the tadpole tail?

Although "programmed cell death" has been postulated to underlie the mechanism for the disappearance of the tadpole tail, critical factors that trigger this phenomenon remain to be elucidated. To investigate the mechanism for the disappearance of the tail, changes in morphology, DNA status and the enzymes which metabolize reactive oxygen species were determined in the tail of Rana rugosa tadpoles. Histological examination revealed that apoptotic cell death was apparent in the tail myocytes during metamorphosis.

Dystrophin-glycoprotein complex purified from hamster cardiac muscle. Comparison of the complexes from cardiac and skeletal muscles of hamster and rabbit.

The dystrophin-glycoprotein complex was isolated from hamster ventricular muscle by a method involving homogenization of muscle directly in the presence of 1% digitonin, followed by chromatography on succinylated wheat germ agglutinin agarose, Diethyl aminoethyl (DEAE) cellulose, and/or immunoaffinity agarose. Protein yield of the DEAE cellulose-purified dystrophin-glycoprotein complex was 120 +/- 30 (n = 3) micrograms per 5 g hamster ventricular muscle. The cardiac dystrophin-glycoprotein complex, unlike the skeletal muscle counterpart, could not be solubilized from a microsomal fraction with digitonin or some other detergents.

Effects of the 7 21 Robertsonian translocation on fertilization rates and preimplantation development of bovine oocytes in vitro.

A study was conducted to investigate the effect of the 7/21 Robertsonian translocation on fertilization and subsequent development of bovine oocytes matured in vitro. Semen from Japanese Black bulls, 2 with a normal karyotype (Bulls A and B) and 2 that were heterozygous for the 7/21 translocation (Bulls C and D), was used in this study. In vitro matured bovine oocytes were inseminated with frozen-thawed sperm capacitated with heparin.

Structural differences between XX and ZW sex lampbrush chromosomes in Rana rugosa females (Anura: Ranidae).

In this study we investigated the morphology and pairing behavior of sex lampbrush chromosomes of XX and ZW females of Rana rugosa from five localities in Japan. Whereas lampbrush chromosomes of XX females from Hiroshima and Isehara had subterminally located centromeres and showed remarkable similarity, those of XX females from Hamakita had the centromeres in the middle. Analysis of landmark configurations revealed that chromosome Xq of Hamakita females closely resembled a part of Xq of Hiroshima and Isehara females, whereas Xp of Hamakita females was inverted compared with the other part of Xq of Hiroshima and Isehara females.

Effect of inferior vena cava occlusion on left ventricular end-systolic pressure-volume relations in intact canine hearts--modulation by the autonomic nervous system.

The effect of inferior vena cava occlusion (IVCO) on end-systolic pressure-volume relations (ESPVR) of the left ventricle was studied in intact canine hearts. In 12 anesthetized open-chest dogs, left ventricular (LV) pressure and volume were measured simultaneously using a microtip catheter and a conductance catheter, respectively. ESPVR was constructed from LV pressure-volume loops during IVCO (10 sec) and subsequent IVCO release under 5 conditions: control, after righ or left cardiac sympathetic nerve (CSN) stimulation, bilateral vagotomy (VAT), and both VAT and bilateral CSN resection.

Strong expression of the calreticulin gene in the liver of Rana rugosa tadpoles, but not adult frogs.

In the present paper we report the purification of calreticulin (CLT) from livers of the frog, Rana rugosa, the cloning and sequencing of its cDNA, and the CLT gene expression. CLT with M(r) = 52 kDa, estimated by SDS-PAGE, was purified from frog livers. Using rat CLT cDNA as a probe, a 2.

Expression of a dystrophin-sarcoglycan complex in serum-deprived BC3H1 cells and involvement of alpha-sarcoglycan in substrate attachment.

Dystrophin and alpha- and gamma-sarcoglycans were newly expressed in BC3H1 cells during differentiation induced by serum withdrawal. These proteins formed a tight complex with other dystophin-associated proteins (DAPs), as detected by immunoprecipitation with anti-dystrophin antibody. Integrins beta 1 and beta 3, vinculin, and focal adhesion kinase were also detected in the same immunoprecipitate.

Hepatitis B virus carrier status linked to autoimmune hepatitis.

We describe a hepatitis B virus carrier who satisfied the criteria of autoimmune hepatitis proposed by the International Autoimmune Hepatitis Group. A 43-year-old Japanese female showed human leukocyte antigen typing including DR4 in addition to hypergammaglobulinemia, presence of autoantibodies, and liver histology suggestive of autoimmune hepatitis. Moreover, the predominant presence of hepatitis B core antigen in nuclei rather than in cytoplasm of hepatocytes suggested less of a possibility of liver cell damage related to hepatitis B virus infection.