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Biomedical subjects

T Miwa

Publications and source records attributed to T Miwa.

At least 163 records · Page 9Linked to original sources
PubMed1994

Olfactory disturbance induced by deafferentation of serotonergic fibers in the olfactory bulb.

The serotonergic neurons of the brain stem project widely throughout the central nervous system, and the olfactory bulb is one of the major forebrain targets of the ascending serotonin pathway. According to physiological studies, neurons of the olfactory bulb were found to reduce their spontaneous discharge rates by electrophoretically applied serotonin. However, roles of the bulbar serotonin in the sense of smell remain unanswered. In the present study, using 5,7-dihydroxytryptamine, a specific neurotoxin for serotonin, we found that the conditioned rats who learned to avoid a repellent by olfaction lost ability of discrimination by deafferentation of the bulbar serotonergic fibers. Such olfactory dysfunction did not occur in the early stage (three days after injection of the toxin) when the serotonergic fibers disappeared in the bulb, but developed a few weeks later. Interestingly, histological examination revealed marked shrinkage of the bulbar glomerulus which is a major termination site of the bulbopetal serotonergic fibers, and also a synaptic site of olfactory receptor cells and bulbar output neurons. The results indicate that depletion of the serotonergic fibers in the olfactory bulb causes glomerular atrophy and olfactory disturbance in the rat.

5,7-Dihydroxytryptamine↗
PubMed1994

Isolation and characterization of a novel gene encoding nuclear protein at a locus (D11S636) tightly linked to multiple endocrine neoplasia type 1 (MEN1).

To identify a gene responsible for multiple endocrine neoplasia type 1 (MEN1), we attempted to isolate potentially transcribable fragments from cosmid clones derived from a region on chromosome 11q13 where genetic linkage studies and analyses of loss of heterozygosity in MEN1-associated tumors have localized the MEN1 gene. By an exon-amplification method, we recovered three exon-like sequences from one of these clones, cCI11-367, and using these sequences as probes we were able to isolate new clones from cerebrum, cerebellum, and fetal-liver cDNA libraries. Sequence analysis of these cDNA clones revealed that the transcribed gene, designated ZFM1, encodes a novel 623-amino-acid protein containing domains with interesting structural properties including a nuclear transport domain, a metal binding motif, and glutamine- and proline-rich regions. Analysis by the reverse-transcriptase polymerase chain reaction (RT-PCR) indicated that this gene is expressed in various tissues including endocrine organs such as thyroid gland, pancreas, adrenal gland, and ovary. These data suggest that ZFM1 might be a candidate for mutations that cause MEN1.

Amino Acid Sequence↗
PubMed1994

Asthenopia and the dark focus of accommodation.

To study asthenopia, we compared the dark focus of accommodation of 54 symptomatic and 56 asymptomatic control subjects. The two groups were matched for age and cycloplegic refractive error. Symptomatic subjects were defined as those who complained of asthenopia daily even though their refractive error had been corrected. Subjects with other eye diseases that could produce asthenopia such as strabismus or aniseikonia were excluded. Using a Nidek Autorefractometer AR1600, we first measured non-cycloplegic refractive error (Non-Cyclo R) in a bright room, then the dark refractive state (Dark R) in complete darkness using the instrument with the optical target light extinguished and, finally, determined the cycloplegic refractive error (Cyclo R) after instilling cyclopentolate hydrochloride. The difference between Dark R and Cyclo R was defined as DFcus (Cyclo R) and that between Dark R and Non-Cyclo R as DFcus (Non-Cyclo R). We found both DFcus (Cyclo R) and DFcus (Non-Cyclo R) to be smaller in the symptomatic than in the asymptomatic subjects, indicating that asthenopia is associated with a low rather than a high level of tonic accommodation.

Accommodation, Ocular↗
PubMed1994

Dark focus of accommodation and vergence posture.

We evaluated the dark focus of accommodation and vergence posture in 20 boys and girls, 10 with and 10 without accommodative esotropia, before and after they wore glasses for at least 1 month. Refractive error was measured by Nidek Autorefractometer AR1600. We used two definitions of the dark focus, DFcus (Non-Cyclo R) and DFcus (Cyclo R). DFcus (Non-Cyclo R) = Dark R - Non-Cyclo R. DFcus (Cyclo R) = Dark R - Cyclo R. (Dark R: refractive state in the dark; Non-Cyclo R: non-cycloplegic refractive error; Cyclo R: cycloplegic refractive error.) Vergence posture was measured by prism cover test during distance fixation while uncorrected. DFcus (Cyclo R) was significantly greater in esotropic subjects than in non-esotropic subjects, although DFcus (Non-Cyclo R) did not differ significantly. A significant hyperopic shift in Dark R was observed after wearing glasses. DFcus (Cyclo R) was significantly decreased after wearing glasses, suggesting that wearing glasses is an important variable of the dark focus. Unlike the dark focus, the vergence posture did not change in either group after wearing glasses. The dissociation of the dark focus from vergence posture seems to be inconsistent with previous findings. It is postulated that change in dark vergence after wearing glasses is responsible for the results.

Accommodation, Ocular↗
PubMed1994

Histologic type and gastric acid secretion in gastric cancer.

We investigated gastric acid secretion in 638 gastric cancer patients with respect to the association between aging and histologic types. In intestinal type tumors in which invasion is restricted to the mucosa, and in diffuse type tumors where the tumor invaded the serosa there was a significantly negative correlation between acid secretion and age. However, no relationship was found between gastric acid output and age in signet ring cell carcinoma. On the other hand, a significantly negative correlation between acid secretion and age was shown in male patients with well differentiated type and in females with signet ring cell carcinoma. In conclusion, low acid secretion related to aging may play an important role in developing cancer cells in intestinal type tumors especially in the male elderly, and in diffuse type tumors in the female elderly, respectively.

Adult↗
PubMed1994

Lymphoid interstitial pneumonia as a pulmonary lesion of idiopathic plasmacytic lymphadenopathy with hyperimmunoglobulinemia.

A case of idiopathic plasmacytic lymphadenopathy with hyperimmunoglobulinemia is reported. A 71-year-old man was admitted to the hospital because of the abnormal shadow on chest roentgenogram. Chest X-ray taken on admission showed remarkable diffuse infiltration and pleural thickening. Laboratory examinations revealed an elevated total protein level of 10.1 g/dl, and a gammaglobulin level of 7.0 g/dl including 6,790 mg/dl IgG. Mediastinal lymphadenopathy was observed on a chest CT. The patient underwent open lung biopsy. Heavy infiltration of lymphocytes and plasma cells were seen in the moderately fibrotic pulmonary interstitium. LIP was diagnosed. Lymph node biopsy was also performed. Follicular hyperplasia with prominent germinal centers and plasma cell proliferation in the interfollicular area were seen. Treatment with prednisolone resulted in an improvement in the chest X-ray findings, as well as a diminished polyclonal hypergammaglobulin level.

Aged↗
PubMed1994

Effect of aibellin, a peptide antibiotic, on propionate production in the rumen of goats.

Aibellin was administered in feed to goats (16 to 18 kg of BW) for 12 d. At 80 mg/d, the molar percentage of propionate in rumen fluid increased significantly in 8 d, and the effect lasted for as long as 10 d after administration ceased. Total VFA concentration, protozoa numbers, and NDF digestibility were not depressed significantly at this dosage but were reduced at 100 mg/d with little further increase in the molar percentage of propionate. Therefore, the optimal dosage of aibellin was 80 mg/d under our experimental conditions. In contrast, monensin (30 mg/d) and gramicidin D (60 mg/d) decreased total VFA concentration and protozoa numbers when supplemented to obtain molar percentages of propionate comparable to 80 mg/d of aibellin. From these results, aibellin may be easier and safer to use than monensin and gramicidin D to modify rumen fermentation.

Animals↗
PubMed1994

Characteristics of vacuolating toxin produced by Helicobacter pylori.

OBJECTIVE: We sought a good indicator cell line to use in detecting the vacuolating toxin produced by Helicobacter pylori and in examining the characteristics of the toxin. DESIGN AND METHODS: Using five cell lines [baby hamster kidney (BHK-21), human amnion (FL), human uterine cancer (HeLa), rabbit kidney (RK-13) and African green monkey kidney (Vero)], cytotoxicity assays were performed with 33 H. pylori strains. To analyse the proteins produced by toxigenic and non-toxigenic strains, immunoblotting was done with the sera of patients with gastroduodenal diseases. RESULTS: When RK-13, FL, Vero, BHK-21 and HeLa cells were used for the assay, 73, 61, 27, 27 and 21% of strains, respectively, were toxigenic. The vacuolating toxin is sensitive to heat at 70 degrees C. By immunoblot analysis, under non-denaturing conditions, immune sera recognized proteins with molecular weights of 600,000 and 500,000 in the toxigenic but not in the non-toxigenic strains. CONCLUSION: H. pylori produces vacuolating toxin, which is a heat-sensitive protein at 70 degrees C and is easily detectable by cytotoxicity assay using the RK-13 cell line. Toxigenic H. pylori strains produce various proteins, including this toxin, which are recognized by sera from patients with gastroduodenal diseases.

Animals↗
PubMed1994

[Application of the warm heart surgery to the open heart surgery in children].

Application of the warm heart surgery to the children's open heart surgery has been reluctant, because keeping the operative field dry thought to be difficult. In this report, the clinical result of 22 cases of children's open heart surgery using warm heart surgery (Warm Group) was compared with that of other 25 cases using conventional cold cardioplegia (Cold Group). In warm group, rectal temperature was kept at 34 degrees C, continuous coronary perfusion rate was 3 ml/kg/min, and potassium ion concentration for inducing the initial cardiac arrest was 20 mEq/l, and the maintaining dose was 12-17 mEq/l. There were two deaths in Cold group. In warm group, keeping the operative field dry was not difficult by using the specially devised small sucker (2 mm diameter) and, if necessary, temporarily stopping the coronary perfusion (maximum for 7 min). Aorta cross cramping time/total extracorporeal circulation time, CK-MB at 1-POD and maximum dose of dopamine and dobutamine proved the better myocardial protection in warm group (p < 0.01). From this study, it was concluded that warm heart surgery can be applied for children with no difficulty, and showed superior myocardial protection.

Body Temperature↗
PubMed1994

[Right ventricular function after aorto-coronary bypass surgery: with relation to the site of right coronary artery occlusion].

Postoperative right ventricular function was evaluated serially by thermodilution techniques (REF-1, Edwards Laboratories) in patients who underwent aorto-coronary bypass surgery with uneventful postoperative recovery. The patients were divided into three groups depending on the location of critical stenosis of the right coronary artery. The stenosis was proximal to the right ventricular branch in group I (n = 13), distal to the right ventricular branch but proximal to the acute marginal branch in group II (n = 13) and distal to the acute marginal branch in group III (n = 11). Control (n = 20) consisted of the patients with no significant stenosis of the right coronary artery. Cardiac index, intracardiac pressures and amount of cathecolamin used during postoperative course showed no significant differences among the groups including control. With the use of cathecolamine after surgery, right ventricular ejection fraction (RVEF) rose and right ventricular volumes (RVEDV and RVESV) decreased in all the groups except for group I. These values in group I were unchanged. Thus, there were significant differences in RVEF, RVEDV and RVESV between group I and control. These results mean that right ventricular dysfunction may remain even long after occlusion of the proximal right coronary artery.

Aged↗
PubMed1994

[Inhibitory mechanism of experimental stress ulcer in spontaneously hypertensive rats (SHR) from the view point of mucosal blood flow].

Stress ulcer formation is reportedly much less frequent in SHR than in normotensive control rats (Wistar Kyoto Rat: WKY). The purpose of this study was to investigate the mechanism of maintenance of gastric mucosal blood flow (GMBF) during imposed stress in SHR. In stressed-only SHR, GMBF did not significantly change during water immersion and restraint conditions and ulcer index (UI) was significantly lower than that of WKY. Stress conditions led to a fall in blood pressure and a gradual fall in heart rate in WKY and SHR. It was assumed that the changes in blood pressure and heart rate during stress were due to vagal hyperfunction. The catecholamine level in the fundic gland of the gastric tissue was higher in the non-stressed SHR than in the non-stressed WKY. The administration of 6-hydroxydopamine to SHR produced a significant reduction in GMBF during stress conditions and UI was significantly higher in this group than in the stressed-only SHR. In SHR treated with nifedipine, UI was lower than that of the control group and GMBF showed no significant change compared with the stressed-only SHR. However, the administration of verapamil produced a significant reduction in GMBF during stress conditions and increased UI. The norepinephrine and dopamine levels of the groups treated with verapamil were significantly lower than those in the groups treated with nifedipine. These results suggest that local regulation of gastric mucosa mediated by sympathetic hyperfunction in SHR is more important for the maintenance of GMBF during stress conditions than changes in peripheral artery resistance.

Animals↗
PubMed1994

[Evaluation of polymerase chain reaction for diagnosis of Helicobacter pylori infection].

To evaluate diagnostic tests of Helicobacter pylori (H. pylori), we compared polymerase chain reaction (PCR) for the specific detection of H. pylori, culture and positivity of serum antibody against the bacteria in 59 patients with gastroduodenal disease. PCR assay was designed to amplify 203bp of DNA fragments. PCR detected 10pg of H. pylori DNA, or 40 CFU of the bacteria. PCR was positive in 82.1% of histological gastritis with neutrophil infiltration. Culture and serum antibody to H. pylori were positive in 65.0%, and 94.1% of those patients. Detection rate by PCR was significantly higher than that by the culture methods in patients with chronic gastritis. These results demonstrate that PCR is a sensitive diagnostic test for H. pylori infection.

Adult↗