Search PubMed⌕ Search

Biomedical subjects

S Miyoshi

Publications and source records attributed to S Miyoshi.

At least 217 records · Page 12Linked to original sources
PubMed1992

Oxygen transport during incremental exercise load as a predictor of operative risk in lung cancer patients.

To evaluate functional parameters related to the morbidity and mortality after thoracotomy, exercise loading was applied in 31 lung cancer patients under right heart catheterization. The routine pulmonary function and predicted postoperative pulmonary function (ppo) parameters were also evaluated. Patients were grouped according to postoperative complications: no complications (group 1, n = 17), nonfatal complications (group 2, n = 10), and fatal complications (group 3, n = 4). In all the patients %VCppo was above 40 percent and in patients undergoing pneumonectomy, pulmonary artery mean pressure during the unilateral pulmonary artery occlusion test was below 25 mm Hg. FEV1 percent and MVV/BSA were statistically significant between groups 1 and 2 but were not between groups 1 and 3 or groups 2 and 3. The %FEV1 ppo was statistically significant between groups 1 and 2 and groups 1 and 3 but was not between groups 2 and 3. Thus, the routine pulmonary function and predicted postoperative lung function tests, although they are mandatory for screening patients who are at risk, did not definitely discriminate between patients experiencing nonfatal and fatal complications after thoracotomy. VO2/BSALa20, CILa20, O2D/BSALa20, and TPVRILa20 were statistically significant between groups 1 and 3 and groups 2 and 3: in all the group 3 patients, as well as three patients of group 1 and one of group 2, VO2/BSALa20 was below 350 ml/min/m2. On the other hand, O2D/BSALa20 was below 500 ml/min/m2 in all the group 3 patients, while it was above 560 ml/min/m2 in all patients in groups 1 and 2. O2D/BSALa20 was the only parameter that definitely discriminated between experiencing nonfatal and fatal complications. We conclude that in addition to the generally accepted functional guidelines, VO2/BSALa20 should be above 400 ml/min/m2 and O2D/BSALa20 should be above 500 ml/min/m2 in patients who will undergo thoracotomy.

Adult↗
PubMed1992

Comparison of the University of Wisconsin preservation solution and other crystalloid perfusates in a 30-hour rabbit lung preservation model.

The University of Wisconsin solution, which contains a high potassium concentration (120 mmol/L), was evaluated for rabbit lung preservation by comparing it with a modified University of Wisconsin solution with low potassium (4 mmol/L), a low-potassium dextran solution (4 mmol/L), and simple surface cooling. In the first three groups rabbit lungs were flushed in situ with the solution (n = 5 in each group); then the lung-heart block was harvested and stored at 10 degrees C for 30 hours. In the surface cooling group the lungs were harvested without flushing and then simply immersed in saline and stored. For assessment, the stored lung was ventilated with room air and perfused with fresh venous blood at a rate of 40 ml/min for 10 minutes. Assessment of lung function included gas analysis of effluent blood, mean pulmonary artery perfusion pressure, and peak airway pressure. Among these parameters, oxygen tension was most sensitive. Oxygen tension at 10 minutes' perfusion in the modified University of Wisconsin (95 +/- 6 mm Hg) and low-potassium dextran (99 +/- 4 mm Hg) groups was significantly higher than that in the surface cooling (61 +/- 7 mm Hg) and University of Wisconsin (51 +/- 7 mm Hg) groups. There was no difference between the modified University of Wisconsin and low-potassium dextran groups or between the surface cooling and University of Wisconsin groups. We conclude that the low-potassium University of Wisconsin solution is superior to the high-potassium University of Wisconsin solution and that the lactobionate and raffinose included in the University of Wisconsin solution as impermeants do not improve lung preservation in this model.

Adenosine↗
PubMed1992

[A clinical investigation on renal pelvic and ureteral tumors].

Sixty-six patients with renal pelvic and ureteral tumors were treated in our hospital between June 1974 and June 1991. These cases consisted of 27 renal pelvic tumors, 31 ureteral tumors and 8 renal pelvic and ureteral tumors. Their ages ranged from 43 to 86 years old (average: 65). There were 46 males and 20 females. The surgical method involved total nephroureterectomy with a cuff for 44 patients, nephroureterectomy for 3, nephrectomy for 9, total nephroureterectomy with total cystectomy for 5 and partial ureterectomy for 2. Histologically, there were 60 transitional cell carcinomas (TCC), 2 squamous cell carcinomas (SCC) and 4 TCC with SCC. As for the pathological stage, 13 were pTa, 16 pT1, 12 pT2, 11 pT3, 13 pT4 and 1 pTX. Subsequent bladder tumors were found in 13 patients (19.7%). The overall survival rate at 1, 3 and 5 years were 80%, 68% and 52%, respectively according to the Kaplan-Meier's method. In this series, the pathological staging was the most important prognostic factor.

Adult↗
PubMed1992

Ecology and distribution of toxigenic Vibrio cholerae in aquatic environments of a temperate region.

The occurrence of a human pathogen, Vibrio cholerae, in aquatic environments and the distribution of toxigenic strains were studied for 2 years. The pathogen was isolated from freshwater, brackish and marine environments. V. cholerae non-01 was frequently recovered but the 01 serogroup was not detected. Of the 57 environmental strains tested, eight (12%) were found to be potentially toxigenic. A number of atypical V. cholerae 01 strains were found which showed higher virulence potentials than the serogroup non-01 strains. A significant correlation of the incidence of the pathogen was noted with water temperature in freshwater environments. In marine environments, a reciprocal correlation of the V. cholerae count and salinity was observed. The present study describes the ecology of V. cholerae in aquatic environments of a temperate region and notes that the occurrence of potentially virulent strains could be of public health significance.

Cholera Toxin↗
PubMed1992

[Clinical study on incidental renal cell carcinoma].

Of 93 patients with renal cell carcinoma treated at our hospital between January 1974 and December 1990, thirty-two cases with incidentally detected cancer were evaluated clinically and pathologically. The average age of the patients was 61 years old ranging from 39 to 84 years. There were 25 men and 7 women with a sex ratio of 3.6:1. Fourteen tumors had developed in the right kidney and 17 in the left kidney. One patient had bilateral tumors synchronously and was treated by radical nephrectomy with contralateral enucleation of the tumor. The proportion of incidental renal carcinoma has been increasing steadily; 87.5% of the cases was found by either abdominal ultrasonography or CT scan. Nineteen patients (59.4%) had a tumor smaller than 5 cm in diameter. There were 29 cases with G1 or G2 renal cancer and twenty with pT2. The five-year survival rate in the incidental cases was 52.2% with significantly better survival than in cases when metastasis was initially suspected, but there was no significant difference in survival between the incidentally found cases and the cases of symptomatic renal cancer.

Adult↗
PubMed1991

Cytoskeleton in microridges of the oral mucosal epithelium in the carp, Cyprinus carpio.

Microridges produce a characteristic fingerprint-like pattern on the surface of fish oral mucosa. The cytoskeleton in these microridges was examined by immunofluorescence microscopy and transmission electron microscopy after detergent extraction and decoration with myosin subfragment 1. The effect of cytochalasin B on microridges was probed with scanning electron microscopy. Immunofluorescence microscopy revealed that actin filaments were present throughout the periphery of the epithelial cells and were especially localized beneath the free surface of the epithelium. In thin sections treated with Triton X-100, the majority of filaments in the microridges and their bases were found to be actin filaments and a plexus of keratin filaments that underlay the network of actin filaments. A part of the plexus of keratin filaments entered the microridges. After extraction with Triton X-100 and decoration with myosin subfragment 1, decorated actin filaments were found in the microridge cores, connected to the keratin filaments. The keratin filaments aggregated in the pattern of microridges and a few of them protruded into the microridges. Treatment with cytochalasin B caused microridges to disappear or to become thinner and lower or to change short or microvillus-like microridges. When most microridges disappeared, the surface of the superficial cells was prominently swollen, but the cell boundaries were fastened, and the microridges in the periphery were preserved. On the basis of these observations, the possible roles of actin and keratin filaments in the maintenance and the formation of microridges are discussed.

Actins↗
PubMed1991

Filtration coefficient in isolated preserved and reperfused canine lung.

The filtration coefficient (Kf) in Starling's equation for fluid exchange was estimated in isolated reperfused canine lobes to evaluate the effect of ischemia-reperfusion injury on alveolar-capillary permeability quantitatively and to determine the inhibitory effects of a high dose of methylprednisolone (MPS) or dimethylthiourea (DMTU), a potent hydroxyl radical scavenger, on this injury. We reperfused isolated canine left lower lobes (LLLs) with blood at a constant flow after 3 hr of warm (38 degrees C) or cold (4 degrees C) ischemia and measured Kf after 1 hr of reperfusion. The mean value of Kf (+/- 1 SD) in the cold ischemic lobes (COLD, n = 7), 0.13 +/- 0.04 g.min-1.cmH2O-1.100 g-1, was not different from that in the control nonischemic lobes (CONT, n = 6), 0.10 +/- 0.04 g.min-1.cmH2O-1.100 g-1. In contrast, the mean value of the Kf in the warm ischemic lobes (WARM, n = 7), 0.38 +/- 0.17 g.min-1.cmH2O-1.100 g-1, was significantly (P less than 0.001) higher than in CONT.MPS (30 mg/Kg) or DMTU (0.75 g/kg) administered before isolation of LLL and before reperfusion reduced the increase in Kf in warm ischemic lobes to 0.19 +/- 0.09 and 0.19 +/- 0.05 g.min-1.cmH2O-1.100 g-1, respectively (P less than 0.005 WARM vs MPS, and P less than 0.01 WARM vs DMTU). MPS and DMTU also attenuated the impairment of gas exchange. We conclude that (1) reperfusion after 3 hr of warm ischemia increases Kf but after cold ischemia does not, and (2) MPS and DMTU prevent the increase in Kf.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Direct amygdaloid projections to the superior salivatory nucleus: a light and electron microscopic study in the cat.

Amygdaloid projections to the superior salivatory nucleus (SSN) were investigated in the cat by using the anterograde and retrograde tracing techniques of horseradish peroxidase (HRP). After HRP injections were made into the lingual nerve, retrogradely labeled SSN neurons were located in the lateral tegmental field medial to the spinal trigeminal nucleus from the middle level of the superior olivary nucleus to the caudal level of the facial nucleus. These labeled neurons, triangular, oval or polygonal in shape, were small to medium-sized (12-29 microns) and formed loosely packed clusters. In further HRP studies, HRP injections were made into the amygdala and in the reticular formation containing the SSN neurons. The results suggested that the SSN receives direct afferents from the central nucleus of the amygdala with ipsilateral predominance. Final proof of such direct connections from amygdala to the SSN can be obtained only by electron microscopic study. Therefore, HRP injections were made into the lingual nerve and in the amygdala in the same animal and electron microscopic observations were carried out on the SSN. It appeared that anterogradely labeled amygdalo-tegmental fibers formed axosomatic and axodendritic synaptic contacts with retrogradely labeled SSN neurons.

Afferent Pathways↗
PubMed1991

Alpha-macroglobulin-like plasma inactivator for Vibrio vulnificus metalloprotease.

The metalloprotease produced by Vibrio vulnificus (VVP) is known to be quickly inactivated by plasma proteins which belong to the class of alpha-macroglobulins in vitro at a molar ratio of 1:1. But the in vivo potential of the inactivators has not been studied. Macroalbumin (MA), a member of alpha-macroglobulins in guinea pig plasma, was found to inactivate VVP by means of physical entrapment in vitro. In vivo actions of VVP, permeability-enhancing and hemorrhagic actions, were greatly augmented by simultaneous injection of the antibody against MA, which had no effect on in vitro proteolytic action toward azocasein. The interstitial-tissue space in the normal guinea pig skin contains a negligible amount of MA. However, sufficient MA was present in the extravascular fluid collected after the intradermal injection of VVP. Besides, in the extravascular fluid, VVP formed a complex with MA and no inactivator other than MA was found. These results indicate that plasma MA leaked from the vascular system owing to the permeability-enhancing and hemorrhagic actions of VVP, resulting in inactivation of VVP in situ.

Animals↗
PubMed1991

Purification and characterization of a lecithin-dependent haemolysin from Escherichia coli transformed by a Vibrio parahaemolyticus gene.

Lecithin-dependent haemolysin (LDH) of Vibrio parahaemolyticus was purified from Escherichia coli C600 transformed with a plasmid (pHL591) ligated with a 1.5 kb DNA fragment of V. parahaemolyticus. The final preparation comprised two LDH proteins with different molecular masses which were immunologically cross-reactive and had the same enzymic activity. The LDH was a phospholipase hydrolysing both fatty acid esters of phospholipid, i.e. it hydrolysed phosphatidylcholine (PC) to lysophosphatidylcholine (LPC) and then LPC to glycerophosphorylcholine (GPC). From this point of view, LDH should be classified as a phospholipase B. Phospholipase B, however, does not usually show haemolytic activity, because the intermediate (LPC), which is the actual haemolytic agent, is immediately hydrolysed to the final product (GPC). On the other hand, LPC formed by LDH action was comparatively stable, because the rates of the two reactions catalysed by LDH, PC to LPC and LPC to GPC, are almost the same. This is the reason that LDH shows haemolytic activity. Therefore, LDH of V. parahaemolyticus is an atypical phospholipase to be designated as phospholipase A2/lysophospholipase.

Amino Acid Sequence↗
PubMed1991

Vascular permeability enhancement by Vibrio mimicus protease and the mechanisms of action.

Vibrio mimicus, a causative agent of gastroenteritis, has also been reported to attribute to extraintestinal infections. Recently we have purified a metalloprotease produced by the pathogen: however, the role of the protease in V. mimicus infection has not been documented. The V. mimicus protease (VMP) was found to enhance vascular permeability and form edema when injected into the dorsal skin of guinea pig and rat. The permeability enhancement by VMP was observed in a dose-dependent manner in both guinea pig and rat skin. In guinea pig, an inhibitor of the angiotensin-converting enzyme was found to augment the permeability enhancement reaction. The permeability enhancement was significantly blocked by soybean trypsin inhibitor (SBTI), an inhibitor of plasma kallikrein reaction. In vitro conversion of plasma prekallikrein to kallikrein by VMP was also noted. In rat skin, the permeability enhancement reaction was not blocked by antihistamine or SBTI. However, the reaction was partially blocked when a mixture of antihistamine and SBTI was administered with VMP. It is apparent from the study that in guinea pig skin, VMP enhances vascular permeability through activation of plasma kallikrein-kinin system which generates bradykinin, whereas in addition to the activation of plasma kallikrein-kinin cascade in the case of rat, stimulation of histamine release from mast cells and other unknown mechanism seem to be also a cause of the permeability enhancement reaction. These results suggest that VMP may play a role in extraintestinal infections with edema caused by the pathogen.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1991

Structures and activity of angiotensin-converting enzyme inhibitors in an alpha-zein hydrolysate.

Peptides that inhibit angiotensin-converting enzyme (ACE) were isolated from alpha-zein hydrolysate prepared with thermolysin. Their chemical structures were identified by Edman degradation and fast-atom bombardment mass spectrometry. Most of them were found to be tripeptides such as Leu-Arg-Pro, Leu-Ser-Pro, and Leu-Gln-Pro, having IC50 values of 0.27, 1.7, and 1.9 microM, respectively. These peptides were synthesized by a solid phase procedure and had similar ACE inhibitory activities as the isolated inhibitors. The hypotensive activity of Leu-Arg-Pro on spontaneously hypertensive rats was also investigated, with the result that the the blood pressure decreased by 15 mmHg after a 30 mg/kg intravenous injection.

Amino Acid Sequence↗
PubMed1991

Role of Vibrio mimicus protease in enterotoxigenicity.

Recently, we have purified and characterised a metalloprotease produced by Vibrio mimicus. The role of V. mimicus protease (VMP) in fluid accumulation (FA) in rabbit ileal loops (RIL) was investigated. Although live cells or crude VMP prepared from cell-free culture supernatant showed activity in RIL, the purified VMP failed to induce FA in the RIL. When VMP in crude preparation was inactivated by preparing the fraction in the presence of EGTA (Ethyleneglycol-bis [beta-aminoethylether]-N, N, N1, N1,-tetraacetic acid), a chelating agent for Ca2+ (EGTA-crude), or treatment with phosphoramidon (a metalloprotease inhibitor), the preparation became negative in RIL assay. Again, the EGTA-crude induced FA in RIL when retreated with 2mM CaCl2 after elimination of EGTA. The results show evidences of attribution of VMP in RIL activity. These observations, therefore, suggest that the protease produced by V. mimicus may play a potential role in enterotoxigenicity.

Animals↗
PubMed1991

Influence of intraalveolar oxygen concentration on lung preservation in a rabbit model.

We previously reported the use of an inexpensive screening model for lung preservation involving ventilation and perfusion of excised rabbit lungs after their preservation. We now have extended this model by perfusing the preserved lung in cross circulation with an anesthetized rabbit to permit stable reperfusion of the preserved lungs for 60 minutes. With this model we compared the results of lung preservation with the lungs inflated with nitrogen, room air, or 100% oxygen during 24 hours of hypothermic storage. Four groups of animals were studied: group 1, excision and immediate evaluation; group 2, inflation with room air and storage for 24 hours at 10 degrees C; group 3, same as group 2, with 100% oxygen for inflation during storage; group 4, same as group 2, with 100% nitrogen for inflation during storage. Assessment of the ex vivo perfused lung consisted of (1) blood gas analysis of inflow and outflow blood at 10-minute intervals; (2) continuous pulmonary artery and airway pressure monitoring; (3) measurement of pulmonary venous oxygen tension after 1 hour of reperfusion, with inflow oxygen tension adjusted to 15 mm Hg; (4) wet/dry weight ratio. We conclude that the paracorporeal circuit does not, in itself, cause lung injury over a 1-hour period; lungs preserved with nitrogen inflation rapidly became edematous and failed to function on reperfusion. Preservation with 100% oxygen inflation appears superior to inflation with room air.

Animals↗
PubMed1991

[Effects of diaphragm plication for phrenic nerve paralysis on respiratory mechanics and diaphragm function].

The purpose of this study is to examine the effects of unilateral diaphragm plication for phrenic nerve paralysis on the respiratory mechanics and diaphragm function. Study 1: We performed thoracotomy (BASELINE), left phrenicotomy (INJURY) and left diaphragm plication (PLICATION) in ten dogs. After chest was closed in each condition, measured were the tidal volume (TV), respiratory rate (f), esophageal and gastric pressure swing (delta Pes, delta Pga), dynamic compliance (Cdyn) the ratio of gastric to esophageal pressure swing (delta Pga/delta Pes) and the work of breathing per liter (WOB/L) under stable spontaneous breathing. Study 2: In eight other left-phrenicotomized dogs, Pdi and fractional shortening of the costal diaphragm during contralateral electrophrenic stimulation were measured before and after plication. After plication TV, delta Pga/delta Pes, Cdyn, Pdi and fractional shortening during stimulation increased significantly, whereas Pes and WOB/L decreased significantly compared with INJURY condition. In conclusion unilateral diaphragm plication after paralysis improves the intact hemidiaphragm contractility and diaphragmatic contribution to breathing.

Animals↗