Search PubMed⌕ Search

Biomedical subjects

N Ueda

Publications and source records attributed to N Ueda.

At least 235 records · Page 13Linked to original sources
PubMed1994

[A new neuromuscular transmission monitor (TOF Guard): the rationale behind the method and its clinical usefulness].

TOF Guard is one of the latest developments in the field of neuromuscular monitoring equipment. This system uses a miniature acceleration transducer (a piezo-electric ceramic wafer is used), simply fastened to the thumb with tape. The rationale behind the method is Newton's second law, stating that the acceleration is directly proportional to the force. In this study, authors assessed the accuracy of this system in clinical use, comparing with the force transducer method (Myograph 2000). The result showed that there was a very close positive correlation between the values of T1, TOF ratio and posttetanic count simultaneously measured by both methods. The coefficient of correlation was 0.96, and its significance level was P < 0.001. From the clinical view point, it is concluded that TOF Guard is very useful because of its accuracy and because the equipment is easy to handle, compact and of low price as a neuromuscular monitoring system for routine anesthesia.

Adult↗
PubMed1993

Activin A induces apoptotic cell death.

Activins, members of a family of the transforming growth factor beta (TGF beta), are involved in the regulation of multiple biological events. We found a novel effect of activin A on hybridoma and myeloma cell lines. Activin A exhibited a cytotoxic effect on interleukin-6 (IL-6)-dependent B9 cells and induced a significant increase in the proportion of fragmented DNA. B9 cells exposed to activin A released high amounts of lactate dehydrogenase (LDH) and exhibited the typical ladder pattern of DNA fragmentation of apoptotic cells. IL-6 did not prevent apoptosis of B9 cells induced by activin A. The cytotoxicity of activin A to B9 cells was suppressed by follistatin. On the other hand, TGF beta showed no cytotoxic effect on B9 cells. These findings indicate that apoptosis induced by activin A could be one of the mechanisms to prevent uncontrolled cell growth.

Activins↗
PubMed1993

Arachidonate 12-lipoxygenase of platelet-type in human epidermal cells.

A homogenate of epidermal cells isolated from human skin converted arachidonic acid to 12S-hydroxy-5, 8,10,14-eicosatetraenoic acid and 15-hydroxy-5, 8,11,13-eicosatetraenoic acid as the main lipoxygenase products. The production of these hydroxy acids was not stimulated by the addition of 1 mM NADPH required for cytochrome P-450 reaction, but inhibited by 65-75% with 40 microM nordihydroguaiaretic acid, a nonspecific lipoxygenase inhibitor. In addition to these lipoxygenase products, the epidermal cell homogenate converted arachidonic acid to prostaglandin E2 together with minor amounts of prostaglandins D2 and F2a and 12-hydroxy-5,8,10-heptadecatrienoic acid. Thromboxane B2 was not detected. This finding rules out the possible contamination of platelet 12-lipoxygenase in the epidermal cells. After subcellular fractionation of the epidermal cell homogenate, the 12-lipoxygenase activity was found in the 164,000 x g supernatant, the 164,000 x g pellet, and the 10,000 x g pellet. The cytosolic enzyme and the enzymes solubilized from the two pellets produced 12S-hydroperoxy-5,8,10,14-eicosatetraenoic acid as the primary product in contrast to cytochrome P-450 which produces primarily hydroxy acids. The 12-lipoxygenase in the 164,000 x g supernatant and the solubilized enzymes from the 164,000 x g pellet and 10,000 x g pellet were precipitable by antibodies raised against human platelet 12-lipoxygenase, but not by antibodies against porcine leukocyte 12-lipoxygenase. The immunoprecipitated 12-lipoxygenase from each fraction was almost inactive with linoleic acid as substrate, characteristic of 12-lipoxygenase of platelet-type. Furthermore, 12-lipoxygenase mRNA in the epidermal cells could be reverse-transcribed and amplified by polymerase chain reaction with the primers specific for human platelet 12-lipoxygenase cDNA, but not with those for porcine leukocyte 12-lipoxygenase cDNA. Thus, the 12-lipoxygenase of human epidermal cells is similar to human platelet 12-lipoxygenase in terms of immunogenicity, catalytic property, and primary structure, and distinct from leukocyte 12-lipoxygenase.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1993

Increase in bleomycin-detectable iron in ischaemia/reperfusion injury to rat kidneys.

Iron has been shown to be important in ischaemic, immune and toxic forms of tissue injury in various organs. Although it is generally accepted that iron participates in the generation of powerful oxidant species (e.g. hydroxyl radicals) there has not been any direct evidence that iron capable of catalysing free-radical reactions is increased in tissues in these models of injury. In the present study we demonstrate that ischaemia/reperfusion injury to the kidney results in no significant change in total, nonhaem or ferritin iron levels, but there is a marked and specific increase in bleomycin-detectable iron (capable of catalysing free-radical reactions) in the kidney. The increase in bleomycin-detectable iron is observed only after reperfusion but not during the ischaemic period. In a separate study we demonstrate that despite a drastic reduction in the iron content in the kidney, as a result of feeding an iron-deficient diet, there is a similar and a marked increase in the bleomycin-detectable iron in kidneys accompanied by a lack of protection against ischaemia/reperfusion injury.

Acute Kidney Injury↗
PubMed1993

Immunocytochemical localization of prostaglandin endoperoxide synthase in the bovine intestine.

The localization of prostaglandin (PG) endoperoxide synthase in bovine intestine was examined immunocytochemically with polyclonal antibody raised against PG endoperoxide synthase purified from bovine seminal glands. The most intense positive staining reaction for the enzyme was present in mast cells. Mast cells were found to be widely distributed in the intestinal wall, and were particularly numerous in the lamina propria. Most of the mast cells in the lamina propria of the intestinal villi were elongated and oriented with their long axis parallel to the plane of the absorptive epithelium. In whole mount preparations of jejunal villi, mast cells were seen to form a two-dimensional network in the lamina propria. In addition to mast cells, smooth muscle cells of the inner circular muscle layer and muscularis mucosae, nerve cells and fibers, endothelial cells of arterioles, and serosal epithelial cells also showed faint to moderate staining for the enzyme. These results suggested that mast cells are the major source of PGs in the bovine intestinal wall. The characteristic arrangement of mast cells in the intestinal villi may be related to their functions in this portion of the bovine intestine.

Animals↗
PubMed1993

Bronchial atresia: report of a case and review of the literature.

We report herein an unusual presentation of bronchial atresia in a 28-year-old woman, in whom hyperlucency of the ventral segment, distal to a right extrahilar mass found on a routine chest X-ray, was not recognized. Atresia of the medial branch of the ventral segmental bronchus (B3b) with mucoid impaction in the dilated bronchus was finally disclosed by a right upper lobectomy. The patient had been asymptomatic, and physical examination demonstrated no abnormal findings such as decreased breathing sounds over the affected lung. Localized hyperlucency and a mass are the characteristic radiographic features of bronchial atresia. In the present case, however, hyperlucency distal to the mass, which was retrospectively evident on a computed tomogram of the chest, was not recognized. The preoperative diagnosis was also made difficult by the fact that the atresia was located on a subsequential branch (B3b) of the ventral segmental bronchus of the right upper lobe. Since computed tomography and magnetic resonance imaging are able to make an accurate diagnosis of bronchial atresia possible, surgery is often not indicated for asymptomatic patients. Moreover, although surgical intervention is required for patients with complications such as encroachment of normal pulmonary tissue or infection, resection should be as limited as possible to preserve normal lung tissue.

Adult↗
PubMed1993

Evidence suggesting that iron and calcium are interrelated in oxidant-induced DNA damage.

The effect of iron chelators and agents that buffer cytosolic-free calcium ([Ca2+]i) on hydrogen peroxide-induced DNA strand breaks in LLC-PK1 cells has not been previously examined. In addition, the interrelationship between iron and calcium in the pathogenesis of DNA damage has not been studied in any model of tissue injury. Exposure of LLC-PK1 cells to 1 mM hydrogen peroxide resulted in marked DNA damage, as measured by the alkaline unwinding assay (residual intact double stranded DNA at 10 min, control: 88 +/- 1%; hydrogen peroxide-treated cells: 17 +/- 3%, N = 8). The iron chelators, 1,10-phenanthroline and deferoxamine, and agents which buffer [Ca2+]i, BAPTA and quin-2, provided highly significant protection against hydrogen peroxide-induced DNA strand breaks. We then examined the effect of iron chelators on hydrogen peroxide-induced rise in [Ca2+]i in LLC-PK1 cells. Both 1,10-phenanthroline and deferoxamine prevented the marked and sustained rise in [Ca2+]i induced by exposure of LLC-PK1 cells to 1 mM hydrogen peroxide ([Ca2+]i at 15 min, control 100 +/- 3 nM; hydrogen peroxide 195 +/- 14 nM; 1,10-phenanthroline + hydrogen peroxide 100 +/- 4 nM; deferoxamine + hydrogen peroxide 106 +/- 4 nM; N = 4). We excluded the possibility that the iron chelators were directly chelating calcium by performing experiments using a cell free system. We also confirmed that BAPTA and quin-2, in concentrations used in our study, chelate calcium but not iron or copper.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcium↗
PubMed1993

Gentamicin-induced mobilization of iron from renal cortical mitochondria.

Iron, presumably by participating in generation of hydroxyl radical or other oxidant species or initiation of lipid peroxidation, has been shown to play an important role in several models of tissue injury, including acute renal failure induced by the antibiotic gentamicin. However, the sources of iron remain unknown. Rat renal mitochondria incubated at 37 degrees C with gentamicin resulted in a time- (15-60 min) and a dose-dependent (0.01-5 mM) iron release as measured by formation of iron-bathophenanthroline sulfonate complex FeII-(BPS)3 [at 60 min, control: 1.2 +/- 0.1 nmol/mg protein, n = 7; gentamicin (5 mM): 5.1 +/- 0.4 nmol/mg protein, n = 7]. No formation of FeII(BPS)3 complex was detected in the absence of mitochondria or when incubations were carried out at 0 degrees C. Similar results were obtained when 2,2'-dipyridyl, another iron chelator, was used for measurement of iron release. On the basis on our previous study that gentamicin enhances generation of hydrogen peroxide by renal cortical mitochondria, we examined whether effect of gentamicin on iron release is mediated by hydrogen peroxide. Catalase (which decomposes hydrogen peroxide), but not heat-inactivated catalase, as well as pyruvate, a potent scavenger of hydrogen peroxide, prevented gentamicin-induced iron mobilization. Superoxide dismutase, a scavenger of superoxide anion, or hydroxyl radical scavengers (dimethylthiourea or sodium benzoate) had no effect. Taken together, the data with scavengers indicate that gentamicin-induced iron mobilization from mitochondria is mediated by hydrogen peroxide.

2,2'-Dipyridyl↗
PubMed1993

A solitary renal mass as the only manifest lesion of a B-cell lymphoma.

A patient with a solitary renal mass as the only manifest lesion of B-cell lymphoma was reported. The surgical specimen revealed that the lesion was histologically limited to the renal parenchyma. Liver dysfunction prevented him from receiving systemic chemotherapy. Mediastinal and mesenteric lymph node involvements developed 6 months later. Fortunately, the patient survived without recurrence for 18 months after the surgical removal of these tumors and intensive chemotherapy. Systemic chemotherapy is recommended on patients with renal lymphoma even if the tumor seems to be limited to the organ.

Humans↗
PubMed1993

Glomerulosclerosis induced by in vivo transfection of transforming growth factor-beta or platelet-derived growth factor gene into the rat kidney.

Glomerulosclerosis, a final common lesion of various glomerular diseases, is characterized by mesangial cell proliferation and extracellular matrix (ECM) expansion. TGF-beta and PDGF are known to play a critical role in the regulation of ECM metabolism and mesenchymal cell proliferation, respectively. However, there is little evidence to demonstrate the direct role of each of these growth factors in the pathogenesis of glomerulosclerosis. Using an in vivo transfection technique, we could realize the selective overexpression of single growth factor in the kidney. The introduction of either TGF-beta or PDGF-B gene alone into the kidney induced glomerulosclerosis, although the patterns of action of these growth factors were different; TGF-beta affected ECM accumulation rather than cell proliferation and PDGF affected the latter rather than the former.

Animals↗
PubMed1993

Arachidonate 12-lipoxygenase is localized in neurons, glial cells, and endothelial cells of the canine brain.

12-Lipoxygenase oxygenates the 12 position of arachidonic acid, producing its 12S-hydroperoxy derivative. We have been interested in the distribution of 12-lipoxygenase in the central nervous system. Previously, by the use of a monoclonal anti-12-lipoxygenase antibody, we proved that one of the arachidonate 12-lipoxygenases existed in canine brain. The present study was therefore designed to elucidate the exact immunohistochemical localization of arachidonate 12-lipoxygenase in canine brain, using a polyclonal anti-12-lipoxygenase antibody. Canine brains were irrigated thoroughly with ice-cold heparinized saline and phosphate-buffered saline to remove blood cells, and then were fixed in 4% periodate-lysine-paraformaldehyde at 4 degrees C for 3 hr. Immunostaining by the indirect method with the peroxidase-labeled antibody was performed for light microscopic observation. The immunohistochemical study demonstrated that many neurons and glial cells in the cerebrum, basal ganglia, and hippocampus were positively stained. Biochemical results as described previously and those of immunohistochemistry indicate that 12-lipoxygenase is definitely localized in various brain parenchymal cells.

Animals↗
PubMed1993

Mitral prosthetic dehiscence with laminar regurgitant flow signals assessed by transesophageal echocardiography.

A patient with a Björk-Shiley mitral prosthesis developed progressive heart failure without heart murmur and hemolysis. The prosthetic dehiscence was not diagnosed using transthoracic echocardiography, but transesophageal echocardiography. The regurgitant signals revealed laminar flow pattern with large regurgitant orifice. In patients with mitral prosthetic dehiscence with laminar flow pattern, transesophageal echocardiography can provide reliable diagnostic information.

Adult↗
PubMed1993

In vivo profile of myocardial energy metabolism of pressure-overloaded rat.

Cardiac energy metabolism of pressure-overloaded rat hearts was examined under in vivo and in vitro conditions. Two, 4 and 6 weeks after constriction of the abdominal artery, the hemodynamic and metabolic profiles of hearts in vivo and of perfused hearts were determined. Significant increases in left ventricular weight/body weight (30 to 45% increase relative to the sham group), systolic and diastolic blood pressure (22 to 33% increase) and pressure-rate product (31 to 33% increase) were observed 2, 4 and 6 weeks after the operation, and a slight but significant decrease in heart rate was observed at 2 weeks after the operation. Tissue hydroxyproline content increased (17 to 93%) with time after pressure-overload. These findings are indicators of pressure-overloaded cardiac hypertrophy. The total high-energy phosphates of the in vivo rat myocardium under artificial respiration were lower than those of sham-operated rat myocardium 2 (23%) and 4 weeks (21%), but not 6 weeks after aortic constriction. The maximal oxygen consumption rates of mitochondria, when determined in the skinned cardiac fibers, also decreased 2 (47%) and 4 weeks (36%), but reversed 6 weeks after pressure-overload. However, the myocardial ATP, a utilizing form of high-energy phosphate, of pressure-overloaded rat myocardium remained normal at all times after cardiac hypertrophy. This suggests that alterations in hemodynamic variables of in vivo pressure-overloaded rats may not be attributable to a reduction in the myocardial energy production. In the perfused hearts isolated from pressure-overloaded rats, tissue ATP levels were similar to those of sham-operated rats, although the tissue creatine phosphate tended to be reduced in the pressure-overloaded animals at all stages of cardiac hypertrophy examined. Only a marginal decrease in the tissue high-energy phosphate (13%) was observed 4 weeks after the operation relative to that of sham-operated rats. In contrast, the developed tension of the perfused pressure-overloaded rat hearts was consistently lower (27 to 36%) than that of the sham-operated rat hearts. The results suggest that the high-energy phosphate levels of pressure-overloaded rat myocardium in vitro are unlikely to account for the observed decline in cardiac contractile function. The reduction of myocardial high-energy phosphates of pressure overloaded rats may be due to an adaptative change rather than a causal events.

Adenosine Triphosphate↗
PubMed1993

Long-term results of combination chemotherapy with or without irradiation in small cell lung cancer: a 5- to 11-year follow-up.

Between April 1981 and December 1987, 148 patients with newly diagnosed small cell lung cancer (SCLC) were treated using combination chemotherapy with or without thoracic irradiation and prophylactic cranial irradiation (PCI) in a series of cooperative therapeutic trials. With a minimum follow-up of 4.7 years, 13 (9%) patients survived and were free of SCLC. These included 11 (15%) of 76 patients with limited disease and two (3%) of 72 patients with extensive disease. Three died without any evidence of SCLC (one each from second leukemia, non-small cell lung cancer, and unrelated disease). The remaining 10 (7%) patients are currently alive and free of SCLC beyond 4.7 years. Since late relapse beyond 5 years is a very rare event, these patients may have been cured. However, late toxicity of PCI must be kept in mind. Three among the 10 patients have suffered from neuropsychologic symptoms of varying degrees in severity. Although the long-term survival rate is a benchmark in the treatment of SCLC, modifications of therapy that may potentially avoid such toxicities should be considered hereafter.

Aged↗
PubMed1993

Neuromuscular and hemodynamic effects of mivacurium and succinylcholine in adult patients during nitrous oxide-propofol-fentanyl anesthesia.

The neuromuscular and hem+odynamic effects of mivacurium 0.15 mg/kg and succinylcholine 1 mg/kg were compared in 26 adult patients (ASA I and II) during nitrous oxide-oxygen-propofol-fentanyl anesthesia. Neuromuscular block was monitored by recording the compound electromyogram of the hypothenar muscle resulting from supramaximal train-of-four stimuli applied to the ulnar nerve. Time to onset of over 95% block and duration to 25% recovery of control twitch after injection of mivacurium were significantly longer than for succinylcholine (201 +/- 37.6 vs 54 +/- 5.2 sec and 13.0 +/- 2.2 vs 8.4 +/- 2.1 min; mean +/- SD). Onset of mivacurium with priming technique was shortened (125 +/- 20.7 sec), but was also slower than that of succinylcholine. Although the recovery index during spontaneous recovery was significantly longer for mivacurium than for succinylcholine (6.9 +/- 1.3 vs 5.1 +/- 0.9 min), antagonism with neostigmine at 25% recovery of twitch height sufficiently facilitated the recovery index of mivacurium (4.5 +/- 1.0 min) to a level similar to that of succinylcholine with no statistical difference. The hemodynamic effects of mivacurium were few as compared to those of succinylcholine. In conclusion, mivacurium is considered to have additional advantages for short procedures when succinylcholine is undesirable.

Adult↗
PubMed1993

Determining the optimal time for endotracheal intubation during onset of neuromuscular blockade.

The disappearance of the response to single twitch stimulation (STS), double burst stimulation (DBS) and zero post-tetanic count (PTC) were evaluated to determine which best indicated the optimal time of endotracheal intubation during onset of neuromuscular blockade induced by vecuronium (0.08 mg kg-1) in 199 patients under thiopentone and halothane anaesthesia. Evaluations were performed by mechanomyographic and manual methods using a Myograph and a peripheral nerve stimulator. The study consisted of six parts. In part 1 (n = 30) and part 2 (n = 30), the response to STS (0.1 Hz) were evaluated mechanically and manually, respectively. In part 3 (n = 64), post-tetanic count (PTC) changes were evaluated mechanically. In part 4 (n = 30) and part 5 (n = 30), response to DBS were evaluated mechanically and manually, respectively. Intubation was performed immediately after obtaining zero PTC, or absence of response to STS (0.1 Hz) and DBS, and the intubation score was determined. In the control group of patients, intubation was performed under the same anaesthetic conditions as in parts 1-5 but without the administration of any muscle relaxant. The time from administration of any muscle relaxant. The time from administration of vecuronium until disappearance of response was 2.16 +/- 0.56, 2.49 +/- 0.68, 2.04 +/- 0.29, 2.20 +/- 0.53, and 2.97 +/- 0.61 min in parts 1-5, respectively. Excellent intubation conditions were not established in any of the control patients, and in 50.0, 70.0, 55.0, 70.0 and 90.0% of the patients in parts 1-5, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗