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Biomedical subjects

T Misawa

Publications and source records attributed to T Misawa.

At least 91 records · Page 5Linked to original sources
PubMed1990

Vasoactive intestinal polypeptide response to ethanol in dogs.

Only one report has described the ethanol-induced release of vasoactive intestinal polypeptide (VIP), and its mechanism of action is unknown. We studied changes in mesenteric immunoreactive VIP (IR-VIP) concentrations following the intrajejunal administration of 100 ml of normal saline, 5% and 10% ethanol, and hypertonic saline which was isoosmolar to 10% ethanol (1,670 mOsm/liter) in dogs. Administration of 5% and 10% ethanol resulted in significant and dose-dependent increases in mesenteric IR-VIP. Mesenteric IR-VIP changes and incremental integrated responses to 10% ethanol and to hypertonic saline were the same. We concluded that ethanol-induced VIP release in dogs is mainly due to ethanol's hyperosmolarity.

Animals↗
PubMed1990

Effects of combined use of roxatidine and pirenzepine on gastric secretion in humans.

We examined the effects of the combined use of H2-receptor antagonist (roxatidine) and muscarinic receptor antagonist (pirenzepine) by oral administration on gastric juice and acid secretion in humans. The volume, pH level, and acidity of gastric juice were determined in the sample collected at 9:00 AM 10 hr after either the oral administration of 150 mg of roxatidine or the combined administration of 150 mg of roxatidine and 50 mg of pirenzepine. Significant decrease in volume and acidity and increase in pH were observed in both roxatidine group and combined group compared with control placebo group, but significant difference were not observed in gastric pH and acidity between roxatidine group and combined group. The volume of gastric juice was decreased significantly by the combined administration in comparison with the sole administration of roxatidine. Consequently, the combined oral administration of the two agents was considered to be more effective than the sole administration of roxatidine for clinical cases which require stronger suppression of gastric secretion at the night.

Adult↗
PubMed1990

[Quantitative evaluation of right ventricular overload in cor pulmonale using 201T1 myocardial SPECT].

In patients with right ventricular overload, the free wall of the right ventricle is often visualized by 201T1 myocardial scintigraphy. To determine quantitatively the discriminant and characteristics of cor pulmonale, 201T1 myocardial perfusion single photon emission computed tomography (SPECT) was performed in 16 patients with chronic obstructive pulmonary disease (COPD) and seven with restrictive pulmonary disease (RPD). We selected one section of the short-axis image of SPECT in which the right ventricle was most clearly visualized, and defined the T1-score as the ratio of the sum of counts in the region of interest (ROI) at the anterior, mid and posterior regions of the right ventricular free wall to the sum of counts in the ROI at the posterior, lateral, anterior walls of the left ventricle, and the anterior and posterior regions of the interventricular septum. Correlation of the T1-score with mean pulmonary arterial pressure (mPAP), systolic pulmonary arterial pressure (sPAP), and total pulmonary vascular resistance (TPR), as obtained by right cardiac catheterization, arterial oxygen tension (PaO2), and arterial carbon dioxide tension (PaCO2) were evaluated. The results were as follows: 1. In the patients with COPD, the T1-score correlated positively with mPAP (r = 0.71, p less than 0.005), TPR ( r = 0.69, p less than 0.005), and PaCO2 (r = 0.63, p less than 0.01), and it correlated inversely with PaO2 (r = -0.58, p less than 0.05). However, there was no significant correlation between the T1-score and mPAP, TPR, PaCO2, and PaO2 in the patients with RPD.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

[Noncontact and noninvasive microwave biological measurements].

Without contact probes, the signals of small human body surface movements were obtained with microwave Doppler sensors using a two-phase interferometric method. The signals were then compared with mechanocardiographic records routinely obtained by contact transducers. Furthermore, this system was applied to patients wearing clothes. The study subjects consisted of 20 cardiac patients and 10 normal controls. 1. The microwave signals obtained in the cervical and precordial regions were similar to those of the mechanocardiographic recordings, such as the carotid pulse and jugular venous pulse tracings and the apexcardiogram. There was a significant correlation between left ventricular ejection time (LVET) obtained by microwave Doppler sensors and that by the carotid pulse tracing (r = 0.95). 2. The signals of the microwave Doppler sensor were obtained from the patients wearing clothes. The heart beat components were distinguished from respiratory motion and patients' movements using band-pass filters. These results suggest that this method is capable of evaluating cardiac function noninvasively and thus has a distinct advantage in the field of non-contact measurements.

Heart Function Tests↗
PubMed1990

Endoscopic ultrasonographic detection of carcinomatous invasion and of lymph nodes in the thoracic esophagus.

The use of endoscopic ultrasonography (EUS) for diagnosing the depth of carcinomatous invasion into the esophageal wall and in detecting mediastinal lymph nodes in patients with esophageal carcinoma was assessed. EUS was performed before surgery in 33 patients who underwent subtotal esophagectomy with lymph node dissection in our department of surgery between January 1987 and February 1989. The findings of EUS prospectively correlated with intraoperative macroscopic findings and histopathologic findings of the resected specimens. An accurate diagnosis of the depth of invasion into the esophageal wall was made in 30 of the 33 patients (90.1%). Visualization rates of mediastinal lymph nodes were 92.9%, 53.1%, and 1.0% when the nodes were greater than 10 mm in maximum diameter, 5 to 9 mm, and less than 5 mm, respectively. Although EUS had no diagnostic value for patients in whom the ultrasonic probe could not be inserted beyond the tumor, it is an excellent method for evaluating the depth of invasion and detecting lymph nodes greater than 10 mm in diameter. Detection is not feasible when the lymph node is less than 5 mm in diameter. EUS provides the surgeon with one more tool for the preoperative determination of curability.

Adult↗
PubMed1990

[Mitral valve prolapse syndrome as an etiologic factor of anxiety disorder].

To assess whether a certain somatic disease is involved in the etiology of anxiety disorder, we examined the relationship between anxiety disorder and mitral valve prolapse syndrome (MVP). Patients with anxiety disorder were diagnosed according to the criteria of the American Psychiatric Association (Quick Reference to the Diagnostic Criteria from DSM-III). Two-dimensional echocardiography was carried out on 36 normal controls (15 males and 21 females) and 39 patients with anxiety disorder (19 males and 20 females); including 21 patients with panic disorder, 12 with generalized anxiety disorder, and 6 with atypical anxiety disorder. The echocardiograms were evaluated by a cardiologist unaware of clinical background about these patients. The presence of MVP was diagnosed according to the criteria by Yoshikawa, et al. or Nagata, et al. Findings of MVP were seen in 18 (46.1%) of the patients and 5 (13.9%) of the controls indicating a significantly higher incidence (chi 2 = 7.711, p less than 0.01) in the patients. In the patient subgroups, 14 patients with panic disorder (66.6%) and 4 with generalized anxiety disorder (33.3%) had MVP, showing a significantly higher incidence in the former (chi 2 = 14.335, p less than 0.01) than in the normal controls, but no statistical significance in the latter. No MVP was found in the patients with atypical anxiety disorder. These results suggest that some somatic diseases such as MVP may play a role in the etiology of anxiety disorder, especially panic disorder.

Adult↗
PubMed1990

[Three dimensional model constructed from Tl-201 myocardial SPECT in combination with bull's-eye mapping].

Three dimensional images (3D Model) and Bull's-eye maps of Tl-201 stress and redistribution scintigrams were reconstructed from average distances and relative accumulations per unit area. 3D Models viewed from different angles were studied in cine mode, in conjunction with the Bull's-eye map. The accumulations of Tl-201 were classified into five different ranks. ROC curves for 3D Model were computed. The coronary artery stenoses estimated by 3D Model were found to have statistical correlations with the results of coronary angiography, in one and two coronary vessel disease, but not in three. Concerning the areas and the locations of abnormal Tl-201 distributions, 3D Model images offer more comprehensible informations than the conventional Bull's-eye method, especially around the left ventricular outlet.

Adult↗
PubMed1989

Somatostatin receptors and the effect of somatostatin on histamine-stimulated adenylate cyclase activity in isolated gastric glands of guinea pigs.

To investigate the mechanism of the suppressive action of somatostatin on gastric acid secretion, we determined the somatostatin binding and adenylate cyclase activity on crude membrane fractions of isolated gastric glands of guinea pigs. The binding studies using 125I-Tyr11 somatostatin showed the presence of somatostatin receptors with a single high affinity on crude membrane fractions. The dissociation constant (KD) for somatostatin was 1.05 +/- 0.13 nM, and the number of binding sites (Bmax) was 6.98 +/- 1.27 fmol/mg protein (mean +/- SE, n = 6). The adenylate cyclase activity was increased by histamine, which was completely inhibited by 10(-3) M cimetidine. Somatostatin non-competitively suppressed the histamine-stimulated adenylate cyclase activity in the presence of guanosine 5'-triphosphate (GTP). These results suggest that somatostatin inhibits histamine-stimulated acid secretion through the inhibition of the adenylate cyclase system, via somatostatin receptor and guanine nucleotide binding protein, which is activated by GTP binding.

Adenylyl Cyclases↗
PubMed1989

Cloning and nucleotide sequence of the gene (trh) encoding the hemolysin related to the thermostable direct hemolysin of Vibrio parahaemolyticus.

Vibrio parahaemolyticus isolates derived from an outbreak of gastroenteritis in the Republic of Maldives did not have the genetic potential to produce the thermostable direct hemolysin, but one such isolate produced a hemolysin immunologically related to the thermostable direct hemolysin (T. Honda, Y. Ni, and T. Miwatani, Infect. Immun. 56:61-965, 1988). The Maldives isolates hybridized with the DNA probe for the gene encoding the thermostable direct hemolysin (the tdh gene) under reduced stringencies. A DNA fragment containing the probe-reactive nucleotide sequence was isolated from a selected strain and cloned into pBR322 in Escherichia coli. A clone producing the thermostable direct hemolysin-related hemolysin was obtained by screening with hemolysis assays and by an immunological assay. Nucleotide sequence analysis of the cloned DNA fragment revealed that the gene encoding the thermostable direct hemolysin-related hemolysin (the trh gene), like the tdh gene, encoded the hemolysin subunit composed of 189 amino acid residues. The trh gene had significant nucleotide sequence homology with the tdh gene (68.4% with the tdh1 gene copy and 68.6% with the tdh2 gene copy). The amino acid sequences of the hemolysin subunits deduced from the nucleotide sequences of the trh gene and tdh gene were homologous (61.9% homology with the tdh1-encoded subunit and 63.0% homology with the tdh2-encoded subunit) and contained the two cysteine residues to form an intrachain bond at the same positions, and their possible conformations appeared to be similar as determined by hydrophobicity-hydrophilicity analysis and a secondary structure prediction. The trh and tdh genes may have had a common ancestor and may have evolved by single-base changes so that they maintained the fundamental architecture of the molecules.

Amino Acid Sequence↗
PubMed1989

Impaired left ventricular diastolic filling in patients with familial amyloid polyneuropathy: a pulsed Doppler echocardiographic study.

To assess left ventricular diastolic filling in patients with amyloid heart disease 12 patients with familial amyloid polyneuropathy and 15 normal subjects were studied by pulsed Doppler echocardiography. None of the patients had clinical evidence of overt heart disease or restrictive cardiomyopathy and only two of them showed ventricular wall thickening. The peak flow velocity of rapid diastolic filling and the acceleration rate of early diastolic inflow were significantly lower in patients with familial amyloid polyneuropathy than in controls. The pressure half time was significantly longer in patients than in controls. In addition, the peak flow velocity during atrial contraction and the ratio of atrial peak flow velocity to rapid diastolic peak flow velocity were significantly greater in patients than in controls. Although there were no significant correlations between measurements of diastolic filling and clinical findings in patients with familial amyloid polyneuropathy, the ratio of atrial peak flow velocity to rapid diastolic peak flow velocity was significantly related to left ventricular posterior wall thickness. These findings suggest that in patients with cardiac amyloidosis without restrictive cardiomyopathy, abnormal left ventricular diastolic filling, manifested by a reduction in the rate and volume of rapid diastolic filling with enhanced atrial contraction, can be seen even in the early stage of the disease.

Adult↗
PubMed1989

Left ventricular systolic and diastolic time intervals in familial amyloid polyneuropathy.

To determine left ventricular (LV) systolic and diastolic properties in patients with familial amyloid polyneuropathy (FAP), we analyzed simultaneous recordings of the electrocardiogram, phonocardiogram, carotid arterial pulse, and apex cardiogram in 14 patients and 21 normal subjects. LV systolic and diastolic time intervals were measured. Correlations between the intervals and neurologic disabilities, duration of illness, and age were examined. We found that in patients with FAP, 1) LV relaxation was impaired, especially in early diastole, whereas systolic function was generally preserved, 2) abnormal LV relaxation could be seen before the development of both clinically identifiable heart disease and the abnormalities in systolic function, 3) indexes of LV systolic function and relaxation decreased in parallel with the progress of the disease, duration of illness, and age, and 4) electromechanical delay was markedly increased.

Adult↗
PubMed1989

[The effects of prenatal trimethyltin exposure on development and learning in the rat].

Developmental effects of single prenatal trimethyltin exposure were examined in THA rats. Pregnant rats were injected on gestational day 12 with single dose of trimethyltin chloride (TMT) ip at either 0, 5, or 7 mg/kg. Significant differences between treated and control offspring rats could not be observed in terms of body weight, pinna detachment, incisor eruption, eye opening, surface righting, cliff avoidance, pivoting, negative geotaxis and auditory startle. Spontaneous motor activity and open field behavior in the rats were also not affected by TMT. In Sidman avoidance test, however, the avoidance rate of the treated offspring rats was lower when compared to that of the controls. These results suggest that prenatal TMT administration disrupts learning acquisition.

Animals↗
PubMed1989

Effects of postnatal low-levels of exposure to styrene on behavior and development in rats.

Three groups of rats were exposed by inhalation to either clean air (control group) or styrene monomer at 25 and 50 ppm (styrene-exposed groups) for 7 h/day, 6 day/week, from 1 to 48 days of age. Compared to control group, Styrene-exposed groups showed significant delay in the following developmental indices: body weight gain, appearance of pinna detachment and incisor eruption. With respect to open-field activity, the styrene groups indicated longer latency to enter the field, less number of squares crossed and fewer rearings than those of controls. In the avoidance behavior aspect, the styrene groups attained less achievement level in avoidance rates than that of the control group. Dose-related trends were found between the two exposed groups in body weight increment, exploratory and avoidance behavior. Sex differences were seen on these factors also. These results suggest that at postnatal exposure of low-levels to styrene affects behavior and development in rats.

Animals↗