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Biomedical subjects

Y Chiba

Publications and source records attributed to Y Chiba.

At least 163 records · Page 9Linked to original sources
PubMed1995

[Clinical study of the reliability of monitoring ESP during descending thoracic aortic surgery].

We studied the reliability of monitoring ESP to detect paraplegia due to spinal cord ischemia during thoracic aortic cross-clamping. In eleven patients with descending thoracic aortic aneurysm, we observed the relationship between the ESP change and postoperative paraplegia. Two patients with loss of ESP had normal postoperative neurological function but one of seven patients with low ESP amplitudes (47% of the control value) showed postoperative paraplegia with anterior spinal artery syndrome. Monitoring ESP dose not appear to be reliable to detect paraplegia during cross-clamping of the descending thoracic aorta.

Aged↗
PubMed1995

[Surgical treatment of aortic rupture by blunt chest trauma].

During a ten-year period, seven patients with traumatic rupture of the thoracic aorta were operated upon. Four patients of them were operated within one week. Chest X-rays and chest computed tomography could not always reveal the exact diagnosis of aortic rupture. Intravenous digital subtraction angiography was useful to confirm the diagnosis. The repair of the rupture was accomplished with the adjunct of left heart bypass using Bio-pump, which was useful to reduce the bloodloss with a limited systemic heparinization. Another three patients were diagnosed to have chronic post-traumatic aneurysm of the thoracic aorta and underwent aortic replacement with prosthetic graft. One of seven patients died at seventh postoperative day because of cerebral contusion, the associated lesion of an automobile accident. It is stated that the aortic rupture is immediately fatal in approximately 80% of individuals, and most of remaining 20% die within 2 weeks unless the lesion is repaired. Therefore immediate operative intervention is recommended when the aortic rupture is strongly suspected. Chronic post-traumatic aneurysms should be resected because it has become apparent that the majority of patients with this lesion will develop complication, such as sudden rupture.

Adolescent↗
PubMed1995

[A case report of chronic sternal osteomyelitis after thoracic aortic aneurysmectomy].

A 76-year-old man, who was complicated with chronic sternal osteomyelitis after thoracic aortic aneurysmectomy was reported. He was treated with local wound care and antibiotics for about 3 months, but cutaneous fistula with persistent discharge required sternal bone debridement and omental pedicle grafting. After this treatment the patient was uneventful. 67Ga scintigram and 67Ga-SPECT may be more useful in the diagnosis of this serious complication.

Aged↗
PubMed1995

Strain and route differences in airway responsiveness to acetylcholine in mice.

The airway responsiveness to acetylcholine (ACh) was examined in C57BL/6 and DBA/2 mice, which are reported as hyporeactive and hyperreactive strains to ACh, respectively. The airway responsiveness of inhaled ACh was compared with that of i.v. injected ACh. No significant difference in baseline respiratory resistance (Rrs) was observed between strains. The Rrs increment induced by 30 mumoles/kg (i.v.) of ACh was significantly greater in DBA/2 than in C57BL/6 strain. However, the Rrs increments induced by inhalation of ACh were same levels between the two strains. These findings indicate that not only strain but also route differences participate in airway responsiveness to ACh in mice.

Acetylcholine↗
PubMed1994

Purification and properties of bovine liver holocarboxylase synthetase.

Holocarboxylase synthetase was purified 18,000-fold from bovine liver cytosol by a sequence of ammonium sulfate fractionation, alumina C gamma fractionation, DEAE-Sepharose CL-6B, EAH-Sepharose 4B, Sephacryl S-200 HR, Bio-Gel HTP, and Phenyl-Superose HR 5/5 chromatographies. Holocarboxylase synthetase activity was assayed using apopropionyl-CoA carboxylase from a patient with holocarboxylase synthetase deficiency as a substrate. Apopropionyl-CoA carboxylase was easily prepared from cultured lymphoblasts from this patient. Enzyme activity coincided with a 64,000-Da protein band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Additionally, the molecular mass of the native enzyme was estimated to be 60,000 Da by gel filtration on Sephacryl S-200 HR. These results suggest that purified holocarboxylase synthetase from bovine liver cytosol is a monomeric enzyme. Its Km value for biotin was estimated to be 13 nM.

Animals↗
PubMed1994

The significance of glutathione peroxidase on myocardial protection in the rat hearts: the key of clarify the cause of vulnerability to reperfusion injury in infantile cardiac operations.

Selenium (Se) is an integral component of glutathione poeroxidase (GSHPx), and the serum selenium concentration is age-depend. We speculated that myocardial GSHPx had relation to reperfusion injury in open heart operations, especially in infants in whom GSHPx activity is low. This study correlated GSHPx activity with the serum and myocardial selenium concentrations in Wistar rats, which were divided into three groups, infants, Se-deficient rats, and control rats. Serum GSHPx activity in infant and Se-deficient rats (22.7 +/- 3.5 U/g protein, 24.6 +/- 22.2 U/g protein) was lower than that in controls (179 +/- 12.0 U/g protein). The serum selenium concentration in infant and Se-deficient rats (3.81 +/- 0.81 micrograms/g protein, 2.06 +/- 1.69 micrograms/g protein) was also lower than that in controls (7.32 +/- 2.96 micrograms/g protein). The myocardial GSHPx activity was significantly lower in infants and Se-deficient rats (4.76 +/- 1.05 x 10(-1) U/mg protein, 3.38 +/- 0.32 x 10(-1) U/mg protein) than that in controls (8.03 +/- 0.57 x 10(-1) U/mg protein). However, the myocardial selenium concentration in infants (1.42 +/- 0.24 x 10(-1) micrograms/mg protein) was significantly higher than that in the other groups (0.31 +/- 0.06 x 10(-1) micrograms/mg protein, 0.28 +/- 0.04 x 10(-1) micrograms/mg protein). Next, in Se-deficient and control rats, isolated hearts were perfused for aerobically with Krebs-Henseleit solution in the Langendorff mode for 15 minutes, followed by 60 minutes of global ischemia at 4 degrees C and then reperfused for 30 minutes in a working mode. The hemodynamic parameters were measured.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Multicystic aneurysmal dilatation of bilateral coronary artery fistula.

Bilateral coronary artery fistula constitutes an uncommon subgroup of coronary artery fistulas that may have a distinct embryologic origin. Coronary artery fistulas usually show a tortuous arrangement upon coronary angiography, but aneurysmal dilatation is rare. We report here an extremely rare case of coronary artery fistula originating from both coronary arteries, which showed multicystic aneurysmal dilatation.

Aged↗
PubMed1994

Water-soluble carbodiimide for the fluorescent measurement of the carboxyl group produced by enzyme reactions.

Fluorescent measurement of the carboxyl group was achieved using water-soluble carbodiimide, EDC (1-ethyl-3-(3- dimethylaminopropyl)carbodiimide). Detection of the active intermediate from the glucuronic acid-EDC reaction mixture using the OPA (o-phthalaldehyde) reagent described in a previous paper was greatly improved to about 4 ng/tube (17 pmol) glucuronic acid owing to a modification of the OPA cocktail. Moreover, fluorescent EDAN (N-1-ethylenediamino-naphthalene) labeling of the carboxyl group was also enabled by EDC catalysis. Quenching of the excess fluorescence of EDAN by OPA increased the sensitivity of EDC-EDAN to a level above the EDC-OPA method. In addition to the assay of enzymes concerning the uronic acid metabolism such as pectinase and pectinesterase, lipase and protease actions could be measured by the EDC-OPA and EDC-EDAN quenching methods, respectively. Thus, these two fluorescent means of detecting carboxyl groups seemed to have extensive application not only to acidic sugars but also to various carboxylic compounds regardless of their solubility.

Carboxylic Acids↗
PubMed1994

Importance of anti-siphon devices in the treatment of pediatric hydrocephalus.

The effects of an anti-siphon device (ASD) on shunt flow and intracranial pressure (ICP) in 16 children with hypertensive hydrocephalus were examined using quantitative radionuclide shuntography (99mTc) with the children in supine and sitting positions. The average age of these patients was 9.5 years. Results were compared with those recorded in 36 patients with adult normal-pressure hydrocephalus (NPH). The closing pressure levels of shunt valve used were low in 8 cases, medium in 7 and high in 1. Half the children (8) had shunt systems with, and the other 8 without, ASD. In the children who had the shunt system without ASD, sitting shunt flow was significantly greater than supine shunt flow, which indicated overdrainage. Conversely, in children who had the shunt system with ASD, supine shunt flow was greater than sitting shunt flow. Because ASD prevented overdrainage, ICP was higher with the shunt system with ASD than with the shunt system without ASD. Without ASD, sitting shunt flow of children was lower than that of adult patients with NPH because of the lower hydrostatic pressure, which correlated with their height. Conversely, in the presence of a shunt system with ASD, sitting shunt flow of children was greater than that of adults, because of the higher ICP and lower hydrostatic pressure. The effect of ASD was smaller in children than in adults, because positive pressure over the ASD was greater (hypertension vs normal pressure) and negative pressure under the ASD was less (short vs tall) in children than in adults. Thus, in children the ASD was effective in preventing overdrainage.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Influence of pH of preservation solution on lung viability.

Recently, various solutions for organ preservation have been introduced. Despite much debate regarding the composition of preservation solutions, the ideal pH of a preservation solution has not been determined. We investigated the effects of the pH of a lung preservation solution on viability using an isolated, ventilated lung perfusion model. Initially, we performed flush perfusion with solutions of five different pH groups (6.60, 7.00, 7.40, 7.80 and 8.20, measured at 10 degrees C). Lungs perfused with pH 6.60 solution had a significantly higher pulmonary vascular resistance than those perfused with pH 7.40, 7.80 and 8.20 solutions. Blood was washed out completely and uniformly with solutions of pH 7.40 and 7.80. After preservation the arterial oxygen tension was significantly greater in pH 7.40 and 7.80 groups than in pH 6.60, 7.00, or 8.20 groups. Moreover, pulmonary artery pressure, airway pressure, and wet/dry weight ratios in the pH 7.40 and 7.80 groups were lower than in the others. We conclude that for both pulmonary flush and storage preservation, solutions of pH 7.40 to pH 7.80 are optimal for lung preservation.

Animals↗
PubMed1994

Antigen-induced airway hyperresponsiveness is associated with airway tissue NEP hypoactivity in rats.

In the present study, the role of sensory neuropeptides in the airway hyperresponsiveness (AHR) was investigated. First, the effect of the depletion of sensory neuropeptides by systemic capsaicin treatment on the AHR to acetylcholine (ACh) induced by repeated antigenic challenge to sensitized rats was studied. We secondly investigated whether the neutral endopeptidase (NEP) activity was altered at the antigen-induced AHR. Male Wistar rats were sensitized and repeatedly challenged with DNP-Ascaris antigen. Twenty-four hours after the last antigenic challenge, a marked AHR to inhaled ACh (0.001-0.03%) was observed. This AHR was significantly attenuated by systemic capsaicin pretreatment prior to sensitization. On the other hand, in normal rats, the airway responsiveness to inhaled ACh was significantly increased by pretreatment with NEP inhibitor, phosphoramidon (3 mg/kg, i.v.), but the NEP inhibitor-induced effect was no more observed in the antigen-induced AHR rats. Furthermore, it was found that the airway NEP activity was significantly decreased at the antigen-induced AHR. These findings suggest that NEP hypoactivity and resultant increased sensory neuropeptides have an important role in the pathogenesis of antigen-induced AHR in rats.

Acetylcholine↗
PubMed1994

Isolation and characterization of mutations in the human holocarboxylase synthetase cDNA.

Holocarboxylase synthetase (HCS) plays an essential role in biotin utilization in eukaryotic cells and its deficiency causes biotin-responsive multiple carboxylase deficiency in humans. We have cloned the human HCS cDNA and show that antiserum against the recombinant protein immunoprecipitates human HCS. A one base deletion resulting in a premature termination and a missense mutation (Leu to Pro) were found in cells from siblings with HCS deficiency. Human HCS shows homology to BirA, which acts as both a biotin-[acetyl-CoA-carboxylase] ligase and a biotin repressor in E. coli, suggesting a functional relationship between the two proteins. The human HCS gene maps to chromosome 21q22.1.

Amino Acid Sequence↗
PubMed1994

Variability in circadian activity patterns within the Culex pipiens complex (Diptera: Culicidae).

Circadian activity was compared among four strains of Culex pipiens molestus Forskal from Iran, Egypt, two localities (Ebira and Yanagawa) in Nagasaki, Japan, and one strain of Cx. p. pallens Coquillett from Japan. Under a 16:8 (L:D) h photoperiod, all the strains showed peaks of activity at lights on and off, with additional activity during both light and dark periods; Egyptian females and both sexes of Cx. p. pallens were inactive during the photophase. Under 0:24 (L:D) h, the length of the free-running activity period was significantly shorter in the "Iran" (21 h) than in the other three Cx. p. molestus strains (range, 21-23 h) and Cx. p. pallens (approximately 24 h). Under 24:0 (L:D) h, the activity rhythm was obscured. The length of the period was shorter in 24:0 (L:D) h than in 0:24 (L:D) h, violating Aschoff's circadian rule. Furthermore, the circadian peak did not always occur every day under 24:0 (L:D) h but rather exhibited "day-skipping."

Animals↗
PubMed1994

Synthesis and evaluation of novel thiazolidine derivatives as thromboxane A2 receptor antagonists.

A series of 3-benzoyl or 3-phenylsulfonyl-2-substituted thiazolidine derivatives were synthesized, and evaluated for their thromboxane A2 (TXA2) receptor-antagonizing effect on (15S)-15-hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5(Z),13(E)-dienoic acid (U-46619)-induced aggregation of rabbit platelet-rich plasma (PRP). A simple 2-aryl-thiazolidine derivative, 3-benzoyl-2-(4-hydroxy-3-methoxyphenyl)thiazolidine (5a), showed mild TXA2 receptor antagonist activity. Modification of 5a led to 2-chloro-4-[3-(4-chlorophenylsulfonyl)thiazolidin-2-ylmet hyl]phenoxyacetic acid (29d), which showed 10 times more potent TXA2 receptor antagonist activity than 5a.

Animals↗