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Biomedical subjects

S Miyoshi

Publications and source records attributed to S Miyoshi.

At least 235 records · Page 13Linked to original sources

Morphometric study of the microvasculature of the main excretory duct subepithelia of the rat parotid, submandibular and sublingual salivary glands.

This study investigated the relationship between the fine structure of the main excretory duct (MED) epithelia and the subepithelial capillaries of the major salivary glands (parotid, submandibular, and sublingual) in the rat. The MED subepithelial capillaries vary in type (fenestrated and continuous), number of fenestrae present in the available fenestrated endothelium (the attenuated area of endothelium), and number of capillaries per unit length of epithelium. In the parotid gland, continuous capillaries predominate, and the capillary density per 200 microns of epithelium (1.73 in region I and 1.03 in region II) is lower than in the other two glands, as is the number of fenestrae per 10 microns of available endothelium (1.97 in region I and 1.25 in region II). The submandibular gland has mainly fenestrated capillaries. The capillary density per 200 microns of epithelium (4.46 in region I and 5.51 in region II) is higher than in the other two glands, as is the number of fenestrae per 10 microns of available endothelium (4.82 in region I and 7.90 in region II). Similarly, in the sublingual gland, fenestrated capillaries are dominant. The density of capillaries per 200 microns of epithelium (4.15 in region I and 4.31 in region II) is intermediate between the parotid and submandibular glands, as is the number of fenestrae per 10 microns of available endothelium (2.98 in region I and 3.83 in region II).

Animals↗

Direct revascularization of bronchial arteries for lung transplantation: an anatomical study.

Direct revascularization of the bronchial arteries for both single-lung and double-lung transplantation would improve airway healing and reduce airway complications after transplantation. We studied the anatomical pattern of bronchial arteries in 30 autopsy cases. In 28 of 30 cases (93.3%), at least one left bronchial artery arose directly from the anterior wall of the descending thoracic aorta. In 25 of the 30 cases (83.3%), at least one right bronchial artery was related to the first right intercostal artery. Injection studies showed that this right intercostobronchial artery supplies the proximal left main bronchus and carina as well as the right bronchus. We developed a technique for extracting the lungs along with the right intercostobronchial artery and a patch of aorta at its origin and applied it to 19 of the dissections. In 17 of the 19 cases studied (89.4%), the right intercostobronchial artery pedicle obtained had a length varying from 6.5 to 8.5 cm, sufficient for attachment of its origin to the ascending aorta of the recipient after double-lung transplantation. The right intercostobronchial artery pedicle provides the possibility for direct bronchial revascularization in right single-lung, double-lung, and lung-heart transplantation. A similar technique, utilizing the left bronchial artery, can be used to revascularize a left lung transplant.

Aorta, Thoracic↗

Acute symptoms due to a huge duplication cyst ruptured into the esophagus.

A 36-year-old housewife complained of a tight feeling in the pharynx with increasing dysphagia, dyspnea, and mild fever. Chest roentgenogram was interpreted as a cystic mass in the middle mediastinum. Computed tomography showed a cystic mass compressing the carina and the esophagus. Ten days after onset, symptoms were suddenly relieved followed by a tarry stool. The chest mass shadow decreased. Esophagofiberscopy showed two fistulas communicating with a cyst that had two chambers. Thoracotomy performed 40 days after onset showed a true duplication of the esophagus with rupture into the esophagus. This is a rare case in which it was possible to observe the sequence of events of a ruptured intramural duplication cyst by means of chest roentgenography, computed tomography, esophagofiberscopy, and cystogram.

Adult↗

Importance of albumen content in whole-body protein synthesis of the chicken embryo during incubation.

The importance of egg albumen content in whole-body protein synthesis was investigated in developing chicken embryos by using lines genetically selected for high and low albumen contents and by removing albumen from eggs before incubation. 2. Whole-body protein synthesis was estimated by injecting L-[15N]-phenylalanine intravenously on day 12 of incubation. 3. Embryos from high albumen eggs had higher whole-body protein synthesis rates than those from low albumen eggs. 4. Whole-body protein synthesis was reduced by the removal of albumen from eggs before incubation. 5. It was concluded that albumen content per se was of crucial importance in regulating whole-body protein synthesis in chicken embryos during incubation.

Animals↗

The superiority of an extracellular fluid solution over Euro-Collins' solution for pulmonary preservation.

Limited donor supply is the major factor restricting the application of lung transplantation. A uniformly reliable method of lung preservation would improve donor organ availability. At present, Euro-Collins' solution, an intracellular fluid-type solution, is most widely used in organ preservation. However, we have previously shown that initial pulmonary flush with an extracellular-type solution (low-potassium dextran solution [LPD]) provided better pulmonary preservation than Euro-C. In the present study, we used an in vitro-ventilated, blood-perfused rabbit lung model to examine whether the mechanism for this improvement was related to the effect of LPD during pulmonary flush or its effect during storage. Rabbit lungs were harvested and stored after pulmonary flush with different solutions (group 1: 400 ml of LPD; group 2: 400 ml of Euro-C; group 4: 300 ml of Euro-C followed by 100 ml of LPD; n = 5 in each group). The lungs were then preserved at 10 degrees C for 18 hr and reperfused with fresh venous blood. After 10 min of reperfusion, lungs in group 1 showed the highest PO2 (group 1: 124.4 +/- 7.7 mmHg; group 2: 46.2 +/- 9.4 mmHg P less than 0.01). Lungs in both group 3 and group 4 showed better lung function and lower wet/dry weight ratio than those in group 2. We conclude that LPD provides better lung preservation by its effects both on pulmonary flush and on storage.

Animals↗

Cytolytic action of Vibrio vulnificus haemolysin on mast cells from rat peritoneal cavity.

The mode of action of Vibrio vulnificus haemolysin (VVH) on mast cells from the peritoneal cavity of the rat was examined. VVH induced histamine release, and damage to the mast cells, in a dose-dependent fashion. When 1 microgram of VVH was added to c. 10(5) mast cells at 37 degrees C, histamine release was observed after a lag period of 5-10 s, and was complete within 5 min. The action was temperature-dependent, and was not induced at 4 degrees C. Disodium cromoglycate, a membrane stabiliser for mast cells, inhibited the histamine release significantly, but the effect was not dose-dependent. Moreover, leakage of lactate dehydrogenase from VVH-treated mast cells was observed. These results suggest that VVH acts on the cell membrane of mast cells and is cytolytic.

Animals↗

Purification and characterization of a protease produced by Vibrio mimicus.

A protease produced by Vibrio mimicus was purified to apparent homogeneity by ammonium sulfate fractionation and successive column chromatography on Sephacryl S-100 and Mono Q Monobeads. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis (PAGE) of the final preparation of the enzyme revealed the homogeneity of the purified enzyme. Conventional PAGE showed that the purified protease migrated as a single band with protease activity. The molecular weight of the protease was estimated to be about 31,000 on the basis of its mobility on sodium dodecyl sulfate-PAGE. The purified protease had both proteolytic and hemagglutination (HA) activities. The proteolytic and HA activities were inhibited by metalloprotease inhibitors and heat treatment. V. mimicus protease therefore appeared as a heat-labile, bifunctional molecule capable of mediating proteolysis and HA. The immunodiffusion analysis showed that the proteases produced by Vibrio cholerae and V. mimicus are immunologically cross-reactive.

Amino Acids↗

Fluctuating hearing loss in lipoma of the cerebellopontine angle.

Two cases of lipoma of the cerebellopontine angle are presented. Both of them showed fluctuating hearing loss, and one case exhibited Menière-like symptoms. In one of the cases, continued clinical surveillance is considered in view of a high chance of postoperative morbidity.

Adult↗

Cardiopulmonary exercise testing after single and double lung transplantation.

The cardiopulmonary response to exercise was investigated in six single and six double lung transplant recipients using a three-minute incremental work rate protocol on a cycle ergometer. Maximum VO2 averaged 44.2 +/- 9.2 percent and 48.5 +/- 5.0 percent of predicted maximal VO2 in the single and double lung transplant groups, respectively. No evidence of ventilatory limitation to exercise was found in either group. Circulatory factors that may have limited exercise capacity included anemia and submaximal heart rates. There was a strong correlation between VO2/kg at venous blood lactate level of 2.2 mEq/L and vital capacity/body surface area in the single, but not in the double, lung recipients. Maximum VO2 in these lung transplant recipients was comparable to previously published values in heart-lung transplant recipients. The factors that limit maximum exercise capacity after lung transplantation deserve further study.

Adult↗

Donor selection for single and double lung transplantation. Chest size matching and other factors influencing posttransplantation vital capacity.

In six single lung transplant (SLT) and six double lung transplant (DLT) recipients, the relationships of the recipient's posttransplantation vital capacity (posttx VCR) to the recipient's predicted normal vital capacity (pred VCR) and the donor's predicted normal vital capacity (pred VCD) were investigated. After left SLT the left posttx VCR was correlated with the left predicted VCD (r = 0.83; p less than 0.05); however, no correlation was found between these after DLT. In contrast, there was a tendency toward correlation between the posttx VCR and the predicted VCR after DLT (r = 0.75; p less than 0.1), but no such trend was apparent after SLT. These results suggest that posttx VCR depends primarily on predicted VCD after SLT and on pred VCR after DLT. Therefore, in donor-recipient size matching for lung transplantation a donor with a pred VCD greater than the pred VCR should be chosen for a left SLT recipient, whereas a donor with a pred VCD near the pred VCR would be suitable for a DLT recipient.

Adult↗

Ecology of mesophilic Aeromonas spp. in aquatic environments of a temperate region and relationship with some biotic and abiotic environmental parameters.

The Ecology of mesophilic Aeromonas species has been investigated since January 1988 to examine their occurrence and distribution in aquatic environments of Okayama Prefecture. Water and plankton samples were quantitatively as well as qualitatively analyzed throughout the seasons from five selected stations including fresh, brackish, and saline environments. Analysis of variance and correlation coefficients among the biotic and abiotic parameters were sought. The organisms were found in all the environs with high densities through all the seasons. Plankton samples yielded higher counts of Aeromonas than the water samples in all the environs. Water temperature seemed to play a significant role on their growth during the winter months, however, no significant seasonal variation nor any correlation with fecal pollution were observed in most of the environments. A reciprocal relationship was seen with salt concentration in the saline environment. Among the currently recognized mesophilic species; A. caviae, A. hydrophila, A. sobria, and A. media were isolated with the predominance of anaerobic biovar. The present study reveals that Aeromonas are widely distributed in fresh, brackish and saline environments of this region. The study also reveals that Aeromonas are autochthonous members in aquatic ecosystems and are indigenous to these environs. Aeromonas species isolated from our environments were found to exhibit drug resistance potential which differed from that of isolates from diverse geographical locales. The high incidence of clinically significant Aeromonas species in this aquatic region could be of public health significance for the inhabitants of this region, as well as a challenge to their dependence on aquatic resources.

Aeromonas↗

[Anesthetic management of patients with cardiomyopathies].

Anesthetic management of patients with cardiomyopathy was studied. In the past 8 years, we experienced 24 surgical procedures for 16 patients complicated with cardiomyopathy of whom 6 cases with hypertrophic type (HCM) and 10 cases with dilated type (DCM). In HCM there was no correlation between the incidence of intraoperative complication and preoperative evaluation by New York Heart Association. In HCM cases who revealed atrial fibrillation, conduction disturbance on ECG and hypokinesis on echocardiogram resulted in high incidence of cardiac complication during anesthesia. Induction of anesthesia is extremely risky if the anesthesiologist is not aware of the presence of cardiomyopathies. In DCM, preoperative episode of heart failure, arrhythmias and conduction disturbance on ECG were considered as anesthetic risk factors. Both in HCM and DCM, there were no statistical significance in complication between general anesthesia and epidural anesthesia. The authors recommend epidural technique as a method of choice for HCM patient.

Adult↗

[Clinical experience with ceftibuten in complicated urinary tract infections].

Twenty-four patients with complicated urinary tract infections (UTI) were received ceftibuten (CETB) 400 mg b.i.d. orally for 5 days, and the following results were obtained. One of the recipients was excluded for negative bacteriuria before treatment. According to the criteria for evaluation of clinical efficacy of antimicrobial agents on UTI, 23 patients were assessed: 9 of them were judged to show excellent responses, 6 to have moderate responses and 8 poor responses. The overall efficacy was 65%. Four patients with indwelling catheter failed to show positive clinical response, but 15 out of 19 patients without indwelling catheter responded positively. As to bacteriological responses, organisms included Gram-positive cocci were eradicated in 28, replaced in 9 and persisted in 6 strains. Of 24 Gram-negative rods except 1 strain of Pseudomonas sp., 23 (96%) were eradicated. Safety evaluation was made in all 24 patients received CETB. No adverse reactions were observed in any cases. As to laboratory test results, slight, transient elevations of GOT, GPT and Al-P of serum were noted in 1 patient. Their values, however, returned to normal levels in 4 weeks.

Adult↗

Activation of hageman factor and prekallikrein and generation of kinin by various microbial proteinases.

Activation of the Hageman factor-kallikrein-kinin system by serratial 56-kDa proteinase was previously demonstrated (Matsumoto, K., Yamamoto, T., Kamata, T., and Maeda, H. (1984) J. Biochem. (Tokyo) 96, 739-749; Kamata, R., Yamamoto, T., Matsumoto, K., and Maeda, H. (1985) Infect. Immun. 48, 747-753). To investigate whether the activation of the system is specific for 56-kDa proteinase or is found similarly with other microbial proteinases, 11 proteinases of microbial origins were studied; the 56-kDa proteinase was the control. For in vitro studies, activation of guinea pig Hageman factor and prekallikrein was examined in purified systems as well as in plasma as a zymogen source. Specific antibodies and inhibitors confirmed the activation steps of the cascade. In the in vivo study the enhancement of vascular permeability in guinea pig skin and its sensitivity to inhibitors of activated Hageman factor, plasma kallikrein, or a kininase were examined. The results from the in vivo experiments were consistent with those in vitro. Taking all the data together, we classified the 11 microbial proteinases into three groups as follows: 1) Serratia marcescens 56-, 60-, and 73-kDa proteinases, Pseudomonas aeruginosa alkaline proteinase and elastase, and Aspergillus melleus proteinase (this group activated Hageman factor but not prekallikrein); 2) Vibrio vulnificus proteinase, subtilisin from Bacillus subtilis, and thermolysin from Bacillus stearothermophilus (this group activated both Hageman factor and prekallikrein); 3) Streptomyces caespitosus proteinase and V8 proteinase from Staphylococcus aureus (this group activated neither Hageman factor nor prekallikrein, but generated kinin from high molecular weight kininogen directly).

Animals↗

Antipyrine clearance per unit liver volume in cirrhotics with and without hepatocellular carcinoma indicating a correlation with histological change of the liver.

The antipyrine metabolizing capacity was studied in 12 patients with cirrhosis of the liver and 12 with cirrhosis and hepatocellular carcinoma (HCC). Antipyrine clearance (Cl) and liver volume (LV) were measured and the antipyrine clearance per unit liver volume (Cl/LV) was calculated. The patients with HCC showed a significantly lower Cl value than those without HCC but there was no significant difference in Cl/LV between the two groups. This suggested that the lower Cl values in the HCC patients resulted from a decrease in residual liver mass. Cl/LV showed positive correlation with % parenchymal cell mass as an indicator of residual parenchymal cell mass per unit volume of liver. This result showed a correlation of Cl/LV with histological change of the liver in cirrhotics.

Adult↗