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Biomedical subjects

J Suzuki

Publications and source records attributed to J Suzuki.

At least 379 records · Page 21Linked to original sources
PubMed1993

Relationship between distribution of hypertrophy and electrocardiographic changes in hypertrophic cardiomyopathy.

To assess the relationship between the distribution of hypertrophy and electrocardiographic changes in patients with hypertrophic cardiomyopathy, magnetic resonance imaging and ECG findings were correlated in 25 patients with apical hypertrophy (group I), 15 patients with both apical and basal hypertrophy (group II), and 11 patients with hypertrophy localized to the basal left ventricle (group III). The number of precordial leads with negative T waves (-0.5 mV or more) was greater in group I than in groups II and III (I = 3.0 +/- 1.5, II = 1.7 +/- 1.5, III = 0.3 +/- 0.6; p < 0.01). Giant negative T waves (-1.0 mV or more) in precordial leads were found in 13 patients (52%) in group I and five patients (33%) in group II but were not found in group III. In contrast, tall positive T waves (> or = 1.0 mV) in precordial leads were found in two patients (13%) in group II and five (45%) in group III but were not found in group I. These results suggest that the distribution of hypertrophy in patients with hypertrophic cardiomyopathy produces a particular T wave polarity in precordial leads.

Adult↗
PubMed1993

Cloning and characterization of a nitrite reductase gene from Alcaligenes faecalis and its expression in Escherichia coli.

The gene (nir) encoding the copper-containing nitrite reductase (NIR) of a denitrifying bacterium, Alcaligenes faecalis S-6, was cloned by a synthetic oligonucleotide-probing method. The nucleotide sequence of the cloned DNA fragment revealed the primary structure of the NIR precursor containing the N-terminal signal sequence for secretion. A nucleotide sequence, possibly recognized by a transcriptional regulator resembling FNR was found upstream of the structural gene. When the cloned gene was expressed in Escherichia coli under the control of the lac promoter at 37 degrees C, NIR was produced as large inclusion bodies and little activity was detected. When cultivation was at 20 degrees C, most of the NIR was detected in the soluble fraction and a significant portion of the protein was translocated into the periplasmic space, accompanied by removal of its signal sequence.

Alcaligenes↗
PubMed1993

[Studies on hemolytic streptococcal infection: 1). Outbreak of group C hemolytic streptococcal infection in Formosan squirrels].

Between mid-October to mid-November 1992, of 500 freely-ranging Formosan and striped squirrels kept at Garden Y in the suburbs of Kanagawa Prefecture, 414 (82.8%) suddenly died one after another by bleeding from the nasal and oral cavities after developing a mild facial swelling. Isolation of microbes including viruses were carried out from the Formosan squirrels that had suddenly died. Various organs from these animals were histologically examined. 1. In bacteriological tests, beta-hemolytic streptococcal strains were isolated in a pure culture from 5 (83.3%) of 6 Formosan squirrels that had died suddenly. By serological analysis, 14 isolated strains were serotyped as group C according to the classification of Lancefield. From their biochemical characteristics, these were identified as Streptococcus equi subsp. zooepidemicus. A drug sensitivity test revealed that ABPC, PCG, SBPC, CMX and CPZ are highly sensitive against the isolates. 2. In the virological test, the viral isolation was applied for three blind passages by primary cultured kidney cells of Formosan squirrels, but no evidence of CPE was obtained. 3. At autopsy, a pathological change was detected mainly in the lungs. Histopathological examinations revealed severe hypertrophic changes of the alveolar wall in the entire pulmonary lobe. Severe congestion, hemorrhagic pneumonia, neutrophils and macrophages infiltration were observed in the hypertrophic alveolar wall. In the other cases, thrombi were observed in the branches of the pulmonary artery. Other organs demonstrated no remarkable histopathological changes. 4. Streptococcal strains were not isolated from the pharynx in all of the employees working at this garden.

Animals↗
PubMed1993

Rat angiotensin II (type 1A) receptor mRNA regulation and subtype expression in myocardial growth and hypertrophy.

Two subtypes of angiotensin II (Ang II) receptors (AT1 and AT2) are distinguished by using the respective specific antagonists. In the present study, we report the regulation of cardiac AT1 type A (AT1A) receptor mRNA levels and the expression pattern of AT1 and AT2 receptors in the growth of the heart and the development and regression of cardiac hypertrophy. The ventricular AT1A mRNA level and the density of Ang II receptors at the neonatal period were significantly increased (3.5-fold and 2.5-fold, respectively) and then downregulated with maturation. The cardiac hypertrophy established in spontaneously hypertensive rats or two-kidney one-clip renovascular hypertensive rats resulted in substantial increases in ventricular AT1A mRNA levels (threefold) and Ang II receptor densities (twofold) as compared with those in respective control rats, whereas the receptor affinity was similar. The proportion of AT1 and AT2 subtypes in the specific Ang II binding in ventricular membranes prepared from normal adult rats was nearly equal. This proportion did not change significantly in the development of myocardial hypertrophy. The regression of cardiac hypertrophy by the normalization of elevated blood pressure completely reversed the increased levels of AT1A mRNA and the receptor density to the control level. Thus, AT1 and AT2 receptors are present in rat ventricular myocardium, and their expression is developmentally regulated and upregulated in response to hypertrophic change. Ang II action exerted through the increased number of Ang II receptors may contribute to the growth of the heart and thus to the maintenance of established hypertrophy as one of the hormones involved in hypertrophy development.

Angiotensin II↗
PubMed1993

Shaker-related potassium channel, Kv1.4, mRNA regulation in cultured rat heart myocytes and differential expression of Kv1.4 and Kv1.5 genes in myocardial development and hypertrophy.

The multiple K+ channels are crucial for repolarization and configuration of the action potential in the neuronal and cardiac cells. In this study, we report the regulatory mechanisms of rapidly inactivating Shaker Kv1.4 channel transcript in the rat heart. Quantitative PCR analysis showed that stimulation with high concentration of KCl, BAY-K 8644, or 12-O-tetradecanoyl phorbol-13-acetate resulted in an immediate and substantial increase (two- to threefold) of Kv1.4 mRNA levels in spontaneously beating myocytes prepared from neonatal rat ventricles. The Kv1.4 mRNA in the ventricle remains at a steady state level after birth and gradually declines with maturation. These results suggest that the Kv1.4 mRNA level is not static and undergoes dynamic modulation by multiple factors that activate intracellular signals. In addition, the expression patterns of Kv1.4 as well as the delayed rectifier Shaker K+ channel Kv1.5 mRNAs were examined in hypertrophied ventricles in which a plateau phase of action potential is remarkably prolonged. The Kv1.5 mRNA level was dramatically repressed while the Kv1.4 mRNA level was remarkably increased. This differential regulation was completely reversed by the normalization of hypertrophy, suggesting that the pathological alterations of K+ channel gene regulation may be involved in the occurrence of ventricular arrhythmias in hypertrophic hearts.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1993

A secondary amyloidosis associated with systemic lupus erythematosus.

Secondary amyloidosis associated with systemic lupus erythematosus has rarely been reported. A 57-year-old female had been diagnosed as having possible systemic lupus erythematosus, although her clinical course was not typical. About one year after the diagnosis, treatment was begun with prednisolone because of progressive renal dysfunction, thrombocytopenia and low serum levels of complements. Recurrent diarrhea and gastrointestinal bleeding soon developed, then amyloidosis was revealed in the stomach and duodenum. Postmortem examination confirmed systemic amyloidosis. We discuss the significance of this rare association of systemic lupus erythematosus and secondary amyloidosis.

Amyloidosis↗
PubMed1993

Auditory and vestibular pathology in brainstem death revealed by auditory brainstem response.

Auditory brainstem response (ABR) before and after the cessation of brainstem activity and postmortem histological findings in the temporal bone and auditory and vestibular pathways of two cases of brainstem death are reported. A brainstem death state of at least 48 h in Case 1 and of at least 24 h for the left side and several hours for the right side in Case 2 was demonstrated by neurological examination, flat EEG, and persistent absence of ABR. Postmortem examination was performed 3 h after death in Case 1, and 1 h after death in Case 2. Pathological studies of the entire length of the auditory and vestibular pathway revealed total autolysis of the organ of Corti and vestibular endorgans and swollen cochlear and vestibular ganglia in Case 1, and, in Case 2, on the right side, preservation of the organ of Corti and vestibular endorgans and mildly swollen cochlear and vestibular ganglia, but on the left side, destruction of the organ of Corti and vestibular endorgan and markedly swollen cochlear and vestibular ganglia. We believe that distinct pathological changes in auditory and vestibular endorgans, and other changes of the cochlear and vestibular ganglia as observed in these two cases, may develop if the duration of absent ABR is prolonged.

Adult↗
PubMed1993

Vestibular pathology of totally deaf ears.

The temporal bone vestibular pathologies of 23 totally deaf ears (16 patients) were studied. Abnormal findings in the saccule were seen more often than in the other vestibular sensory organs. Abnormal findings in the vestibular ganglion cells were found in 7 ears. There were fewer ears with main damage in the hair cells than with main damage in the nerves.

Adolescent↗
PubMed1993

[Gadolinium-DTPA magnetic resonance imaging in the diagnosis of left atrial myxoma in the elderly].

A 85-year-old woman consulted our hospital with general fatigue, palpitation and chest discomfort changing with different postures. Her electrocardiogram showed sinus tachycardia, atrial premature beats and left atrial overload. 53% cardiothoracic ratio, slightly protruding third arch of the cardiac silhouette and dilated pulmonary artery were seen on the chest X-ray. Two dimensional echocardiography revealed a mass in the left atrium although the quality of echocardiography was suboptimal due to her thoracic deformity. There was no uptake of T1-201 or Ga-67 by the mass. The four-chamber view of Tc-99m ECG-gated SPECT radionuclide angiocardiography showed a filling defect in the left atrium. The T1 weighted magnetic resonance imaging revealed a left atrial mass with relatively low signal intensity. After intravenous injection of Gadolinium-DTPA the signal intensity of the mass increased significantly and the contrast of the mass was improved. The size of the mass was 4 x 4 x 3 cm with a stalk connecting to the interatrial septum. These findings were compatible with left atrial myxoma. Gadolinium-DTPA magnetic resonance imaging is useful in diagnosing left atrial myxoma because it provides information on the size, anatomical location, relationship with other cardiovascular structures and even the characteristics of the mass.

Aged↗
PubMed1993

[Effects of cyclophosphamide on spontaneous testicular and pancreatic lesions in WBN/Kob rats].

This study was undertaken to investigate the effects of cyclophosphamide (CP) on spontaneous pancreatitis and testicular atrophy of WBN/Kob rats. CP was given daily in drinking water to groups of 20 male 6-week-old WBN/Kob rats at doses of 0 (control), 1.25 or 2.5 mg/kg for 20 weeks. The final body weight in the 2.5 mg/kg CP group was significantly lower than that in the control group. There were no significant differences in blood glucose levels and weights of the pancreas and testis between groups. On histopathological examinations, pancreatitis and testicular atrophy were noted in each group. However, the incidence of pancreatitis characterized by inflammatory cell infiltration and fibrosis in the 2.5 mg/kg CP group was significantly decreased as compared to the control group. In contrast, testicular atrophy was more severe in the 2.5 mg/kg CP group than in the control group. Thus the results demonstrated that CP has inhibitory effects on the development of pancreatitis and enhancing effects on the development of testicular atrophy in WBN/Kob rats.

Administration, Oral↗
PubMed1993

[Effect of endogenous opioids on gastric functions in man].

Recent studies have demonstrated the presence of opioid peptides in the stomach, neurons of the vagus and the intrinsic nervous system. To evaluate the role of endogenous opioids on gastric mucosal blood flow, serum hormonal response, and gastric secretion, naloxone, a pure opioid antagonist, was infused or sprayed into healthy men, Furthermore, the effect of pentagastrin-induced gastric acid secretion on plasma beta-endorphin concentrations was investigated. Gastric mucosal blood flow was periodically determined by inhaled hydrogen gas clearance. The antrum and the corpus of the stomach could be investigated separately. Intravenous naloxone (40 micrograms/kg/hr) over 30 min caused a significant decline in the antral mucosal blood flow from 55.4 +/- 3.4 (mean +/- SE) ml/min/100 g before infusion to 47.2 +/- 3.0 ml/min/100 g 15 min after the start of injection (P < 0.05), and to 44.8 +/- 3.0 ml/min/100 g after 30 min (P < 0.05) (n = 12). Corresponding corpus mucosal blood flow did not change after infusion of naloxone (n = 8). No change occurred in the antral mucosal blood flow in response to naloxone spraying (0.6 mg) (n = 8). Intravenous administration of naloxone (40 micrograms/kg/hr) had no effect on serum gastrin and secretin concentrations or on the gastric acid secretion stimulated by pentagastrin (n = 8). The status of stimulated gastric acid secretion did not correlate with the release of plasma beta-endorphin. Since naloxone probably mirrors the action of endogenous opioids, these results indicate in humans that (1) endogenous opioids may be involved in the physiological regulation and augmentation of mucosal blood flow for the antrum, (2) the inhibitory effect of naloxone on gastric mucosal blood flow in the antrum does not seem to be mediated via opioid receptors of the mucosa, (3) endogenous opioids have no effect on basal acid secretion and acid secretion stimulated by pentagastrin, and (4) there is no interplay between acid secretion and plasma beta-endorphin.

Endorphins↗
PubMed1993

Determination of pyrimidine nucleoside diphosphates by use of combined reactions of pyruvate kinase and lactate dehydrogenase.

ADP is known to be easily determined spectrophotometrically after it is utilized to produce the corresponding amount of NAD by combined reactions of pyruvate kinase and lactate dehydrogenase. We studied whether CDP and UDP can be also determined in a similar manner if they were incubated for a longer period with an increased amount of pyruvate kinase. It was shown that CDP and UDP could be utilized to produce the corresponding amount of NADH oxidized after an incubation of at least 25 min and that 0 to 300 nmols of these nucleotides were able to be determined spectrophotometrically.

Animals↗
PubMed1993

Connectin content in rabbit cardiac and skeletal muscle.

1. The contents of connectin in rabbit cardiac and skeletal muscle were estimated by densitometry of the bands in SDS gel electrophoresis. 2. The weight ratio of connectin to myosin was 1:9.5 in cardiac muscle and 1:4.2 in skeletal muscle. 3. Assuming that the molecular weights of myosin and skeletal muscle connectin were 5.25 x 10(5) and 4.2 x 10(6) respectively, and a myosin filament consists of 300 myosin molecules, it was calculated that there were approx. 4 connectin molecules per half of myosin filament in rabbit skeletal muscle. 4. In cardiac muscle, the molecular weight of connectin was assumed to be 3.6 x 10(6) and it was estimated that there were about 2 connectin filaments per half of myosin filament.

Animals↗