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Biomedical subjects

M Kawaguchi

Publications and source records attributed to M Kawaguchi.

At least 163 records · Page 9Linked to original sources
PubMed1997

Rete mirabile in humans--case report.

Carotid rete mirabile is a physiological vascular network between the external carotid and internal carotid systems present in some vertebrate species, but rarely observed in humans. We describe a 17-year-old girl with rete mirabile who presented with subarachnoid hemorrhage. Angiography disclosed the bilateral internal carotid arteries (ICAs) ended at the cavernous portion, and abnormal arterial networks visualized via the ICAs and the external carotid arteries in the paracavernous region. The distal ICAs were visualized via the abnormal arterial networks. After 18 years of follow-up she is leading a normal life without neurological problems. Rete mirabile in humans may present with hemorrhage or ischemic symptoms, but the prognosis appears to be good.

Adolescent↗
PubMed1997

[Effects of amrinone on oxygen demand-supply relationship after cardiopulmonary bypass in patient undergoing coronary bypass surgery].

We evaluated the effects of amrinone on oxygen demand-supply relationship after cardiopulmonary bypass (CPB) in patient undergoing coronary bypass surgery comparing with the patients not receiving amrinone. In amrinone treated patients bolus dose of amrinone 1.5 mg.kg-1 was administrated into the reservoir of CPB and followed by continuous infusion at a rate of 5 micrograms.kg-1.min-1. Hemodynamics and blood gas (arterial and mixed venous) measurements were carried out immediately after CPB, 1 hour after CPB and after the chest closure. After the chest closure, cardiac index and oxygen supply in amrinone treated group were significantly higher and systemic vascular resistance was significantly lower than in non-treated group. Left ventricular stroke work index, rate pressure product and oxygen consumption showed no significant difference between the two groups. These data indicate that the amrinone treated patients preserved better oxygen demand-supply relationship after CPB compared with the non-treated patients undergoing coronary bypass surgery.

Amrinone↗
PubMed1997

[Regional cerebral hypoperfusion reduces the effect of rectal midazolam in children with Moyamoya disease].

To investigate the effect of regional cerebral blood flow on the effect of midazolam, we evaluated 99mTc-hexamethylpropylene-amine-oxime-single photon emission computed tomography (SPECT) in 37 cases of childhood moyamoya disease. They were divided into two groups according to the findings of SPECT; one group showed hypoperfusion in the bifrontal regions (n = 20), and the other did not (n = 17). Both groups received 1 mg.kg-1 of midazolam transrectally 30 min before the anesthesia induction and level of sedation was measured with six point scales. Significantly lower level of sedation score was recognized in the group that showed hypoperfusion in bifrontal regions (P < 0.05). Our finding may suggest that regional cerebral hypoperfusion may modify the sedative effect of midazolam in children with moyamoya disease.

Administration, Rectal↗
PubMed1997

[Anesthetic management of patients undergoing irrigation and drainage of chronic subdural hematoma--retrospective analysis of analgesia and sedation under locoregional anesthesia].

We retrospectively investigated the relationship between intraoperative hemodynamic variability and variables including patient background, anesthetic profile, and operative profile in 108 patients undergoing irrigation and drainage of chronic subdural hematoma under locoregional anesthesia. Patients were divided into two groups according to the degree of changes in mean arterial blood pressure (MAP) and heart rate (HR) during operation. Group A (n = 66) had MAP and HR changes < 20%, and Group B (n = 42) had MAP or HR changes > or = 20% of preoperative baseline values. Age was significantly higher in group B than Group A (mean +/- SD; 70 +/- 12 vs. 62 +/- 14 years, P < 0.01). In respect to additional anesthetic agents used (none; no additional anesthetic agents, enough; pentazocine > or = 0.3 mg.kg-1 and droperidol > or = 0.05 mg.kg-1, pentazocine > or = 0.5 mg.kg-1 or droperidol > or = 0.15 mg.kg-1, little; less than "enough"), ratio of "little" administered in Group B was significantly higher than that in Group A (64.3% vs. 37.9%, P < 0.05). These findings suggest that intraoperative hemodynamic variability under locoregional anesthesia in patients with chronic subdural hematoma is associated with age and insufficient use of hypnotic and/or analgesic agents.

Adjuvants, Anesthesia↗
PubMed1996

Development of CD8 alpha alpha+ intestinal intraepithelial T cells in beta 2-microglobulin- and/or TAP1-deficient mice.

The development of CD8+ intestinal intraepithelial T lymphocytes (IEL) was analyzed in mice that are deficient in the expression of MHC class I molecules, owing to either a mutated beta 2-microglobulin (beta 2m) gene or a mutated transporter associated with Ag processing 1 (TAP1) gene, and in mice doubly homozygous for beta 2m and TAPI mutations. In all mutant mice, the population size of major CD8 alpha alpha+ and CD8 alpha beta+ alpha beta-IEL subsets was reduced drastically, and this resulted in a conspicuous decrease in the total number of alpha beta-IEL. Concomitantly, a compensatory two- to threefold increase in the number of gamma delta-IEL consisting mostly of CD8 alpha alpha+ subset was noted. In radiation bone marrow chimeras, this wild-type/mutant phenotype was determined by the genotype of radioresistant host cells, but was not determined by the genotype of reconstituting bone marrow-derived cells. In beta 2m X TCR-delta double mutant mice, however, the CD8 alpha alpha+ but not CD8 alpha beta+ alpha beta-IEL subset expanded dramatically. Thus, in the absence of gamma delta-IEL, alpha beta-IEL in beta 2m-deficient mice outnumbered those in wild-type littermates. These results indicate that the generation of CD8 alpha alpha+ lymphocyte population of alpha beta- and gamma delta-IEL is not dependent, but that of CD8 alpha beta+ lymphocyte population of alpha beta-IEL is dependent on beta 2m- and/or TAP1-dependent MHC class I molecules, expressed by the controlling cells present in the anatomical site, where the development of IEL takes place.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1996

Effects of fructose ingestion on sorbitol and fructose 3-phosphate contents of erythrocytes from healthy men.

To investigate the effect of fructose ingestion on sorbitol and fructose 3-phosphate (F3P) in erythrocytes, we administered 50 g fructose with and without treatment with an aldose reductase inhibitor, epalrestat, to seven healthy, normal-glucose-tolerant, male volunteers aged 20-43 years. The same subjects were given 50 g glucose on another day. The sorbitol and F3P contents in their erythrocytes increased significantly, reaching peak levels at 60 min and 180 min, respectively, following fructose in gestion. On the other hand, glucose ingestion did not cause any statistically significant change in sorbitol content in their erythrocytes, although it significantly elevated their F3P content. Treatment with epalrestat had no significant effect on incremental changes in erythrocyte sorbitol and F3P content following fructose ingestion. This suggests that oral fructose may be converted directly to sorbitol and F3P in erythrocytes instead of being converted via glucose. Thus, the dietary intake of fructose may affect the concentrations of sorbitol and F3P in erythrocytes in normal men.

Adult↗
PubMed1996

Bacteria closely resembling Helicobacter pylori detected immunohistologically and genetically in resected gallbladder mucosa.

A microorganism with close immunohistological and genetic resemblance to Helicobacter pylori was found in the resected gallbladder mucosa of a 41-year-old woman. The woman was admitted to hospital complaining of fever and right hypochondrial pain. Cholecystectomy was carried out under the diagnosis of gallstones and cholecystitis. A microorganism resembling H. pylori (stained with H&E, Giemsa, and Wartin-Starry) was detected incidentally on pathological examination. The microorganism was also positive for immunohistochemical staining. An amplification reaction was seen on genetic examination by the polymerase chain reaction (PCR) method (urease beta-genes). Our findings suggest that H. pylori may be present in tissues other than gastric mucosa.

Adult↗
PubMed1996

Comparison of clinical outcomes of coronary artery bypass grafting and percutaneous transluminal coronary angioplasty in renal dialysis patients.

BACKGROUND: The leading cause of death in chronic renal dialysis patients is cardiovascular disease. As the number of dialysis patients increases, we are encountering more patients with severe ischemic heart disease requiring coronary intervention. METHODS: A retrospective analysis was performed of the short- and long-term clinical results in 23 coronary artery bypass grafting patients and 20 coronary angioplasty patients undergoing chronic renal dialysis. RESULTS: Among coronary bypass grafting patients, there were no hospital deaths. The graft patency rate was 100% for arterial grafts. There were four late deaths and four cardiac events. In coronary angioplasty patients, the lesion success rate was 76%. There were no hospital deaths and three major complications. The restenosis rate was 70%. There were two late deaths and 14 cardiac events. The 5-year cardiac event-free rate was 70% in coronary bypass grafting patients, significantly better than 18% in coronary angioplasty patients (p < 0.001). CONCLUSIONS: Coronary artery bypass grafting in chronic renal dialysis patients can be accomplished with a better short- and long-term outcome than coronary angioplasty, through an intensive perioperative dialysis program and extensive use of arterial grafts.

Angioplasty, Balloon, Coronary↗
PubMed1996

Effect of light-exposure duration on the amount of leachable monomers from light-activated reline material.

Leaching of monomers from light-activated direct intraoral reline material (Lebaron LC) was determined by means of high-pressure liquid chromatography analysis. This study evaluated the effects of exposure duration and thickness to determine appropriate curing conditions that reduce the levels of unreacted monomeric components. Prolonged duration of exposure (30 minutes) reduced the amount of leached monomer. However, the results of this study indicated that the amount of leached monomeric components increased with an increasing reline material thickness. The results suggest that the light-activated reline material should be cured for sufficient prolonged exposure duration.

Chromatography, High Pressure Liquid↗
PubMed1996

Splint therapy for trigger thumb and finger in children.

Forty-three trigger thumbs and fingers in 33 children (15 boys and 18 girls, average age 2 years and 4 months) were treated using a polyethylene splint. Affected digits included 40 thumbs, one index finger, and two middle fingers. The IP joint was stabilized in maximum extension via a strap on the dorsal side. The splint was applied only at night and during day-time naps. Twenty-four digits recovered completely in an average of 10 months, seven digits improved, and two digits required surgery. Eight patients (10 digits) dropped out of treatment. Splint therapy is effective in treating trigger thumbs and fingers in children.

Child, Preschool↗
PubMed1996

Intraoperative electrophysiologic monitoring of ocular motor nerves under conditions of partial neuromuscular blockade during skull base surgery.

The feasibility and usefulness of intraoperative electromyographic monitoring of the oculomotor nerve (CN III), trochlear nerve (CN IV), and abducens nerve (CN IV) were evaluated under conditions of partial neuromuscular blockade in 21 patients undergoing skill base surgery. Intracranial electrical stimulation of each nerve was performed, and compound muscle action potentials (CMAPs) were reconded from the inferior or superior rectus muscle, the superior oblique muscle, and the lateral rectus muscle for monitoring of CN III, IV, and VI, respectively. Partial neuromuscular blockade was achieved by controlled infusion of vecuronium titrated to eliminate about 90% of the twitch response of the abductor pollicis brevis to electrical stimulation of the median nerve. A total of 30 cranial nerves were stimulated intraoperatively. Of these, 29 were successfully monitored (19 CN III, 6 CN IV, 4 CN VI). A relationship was found between intraoperative findings of cranial nerve monitoring, such as disappearance of response and increase in latency and stimulus threshold during manipulation of a lesion, and the presence of postoperative nerve deficits. We conclude that intraoperative electromyographic monitoring of ocular motor nerves is feasible during partial neuromuscular blockade, and that partial neuromuscular blockade does not affect the relationship between findings of intraoperative monitoring and postoperative nerve function.

Journal Article↗
PubMed1996

The excessive production of indole-3-acetic acid and its significance in studies of the biosynthesis of this regulator of plant growth and development.

Because of the importance of indole-3-acetic acid (IAA) in the growth and development of plants, extensive studies of the biosynthesis of IAA have been performed during the four decades since the discovery of IAA as a plant hormone. The pathway for the biosynthesis of IAA in plants remains, however, to be unelucidated, even though studies within the past decade have revealed unexpected aspects of such biosynthesis. By contrast, two pathways to IAA have been characterized in bacteria at the molecular level: the indole-3-acetamide (IAM) pathway (L-tryptophan-->IAM-->IAA); the indole-3-pyruvic acid pathway (L-tryptophan-->indole-3-pyruvic acid-->indole-3-acetaldehyde-->IAA) (Fig. 1). In both pathways, the details of the biosynthesis of IAA were clarified using IAA-overproducing bacteria. After a description of recent advances of the studies of the biosynthesis of IAA in plants, this review focuses on the excessive production of IAA in several organisms and its significance in the studies of the biosynthesis of IAA.

Forecasting↗
PubMed1996

Intraoperative myogenic motor evoked potentials induced by direct electrical stimulation of the exposed motor cortex under isoflurane and sevoflurane.

We monitored myogenic motor evoked potentials (MEPS) during intracranial surgery in 21 patients anesthetized with nitrous oxide in oxygen, fentanyl, and 0.75-1.5 minimum alveolar anesthetic concentration (MAC) isoflurane (n = 11) or sevoflurane (n = 10). The exposed motor cortex was stimulated with a single or train-of-five rectangular pulses at a high frequency (500 Hz), while the compound muscle action potentials (CMAPS) were recorded from the abductor pollicis brevis muscle. Neuromuscular block was monitored by recording the CMAPs from the abductor pollicis brevis muscle in response to electrical stimulation of the median nerve at the wrist (M-response). Stimulation of the motor cortex with a single pulse elicited MEPs in none of the patients, while stimulation with a train-of-five rectangular pulses at high frequency elicited MEPs in all patients. The relationship between MEP amplitude and the level of neuromuscular block induced by vecuronium infusion was evaluated in seven patients. For comparison of the individual measurements, the MEP amplitude at a M-response amplitude of 100% was calculated by means of the individual regression curve as 100% of MEP amplitude. There was a linear correlation between percent MEP amplitude and percent M-response amplitude (r = 0.81; P < 0.01). Intraoperative monitoring of MEP could be performed at a M-response amplitude above 90 % of the baseline value in 10 patients and at a M-response amplitude of 20%-50% of the baseline value in 11 patients. During monitoring of the 21 patients, MEPs did not change in 18 patients and disappeared in two patients. In the remaining patient, MEP amplitudes were attenuated to approximately 10% of the baseline value and recovered after cessation of surgical manipulation. In the two patients in whom MEPs disappeared, motor paresis developed postoperatively. We conclude that 1) intraoperative myogenic MEP monitoring is feasible during isoflurane or sevoflurane anesthesia if stimulation is performed with a short train of rectangular pulses, and 2) that electromyographic monitoring of neuromuscular block is useful to assess intraoperative MEP changes under partial neuromuscular block.

Action Potentials↗
PubMed1996

Pseudoankylosis of the mandible after supratentorial craniotomy.

After temporal craniotomy, pseudoankylosis of the mandible can cause difficult airway management during subsequent anesthesia. However, postcraniotomy changes in maximal mouth opening and the incidence of limited mouth opening have not been characterized. Ninety-two adult patients who underwent elective craniotomy were divided into three groups: Group A (n = 28) included patients who underwent parietal, occipital, or frontal craniotomy without incision of the temporalis muscles; Group B (n = 25) included patients who underwent temporal craniotomy; and Group C (n = 39) included patients who underwent frontotemporal craniotomy. Maximal mouth opening (interincisor gap) and the frequency of limited mouth opening (maximum mouth opening < or = 2.5 cm) were evaluated before operation and 3 days, 1 wk, 2 wk, 1 mo, and 3 mo after operation. The three groups did not differ with respect to age, sex, body weight, height, operative time, anesthetic time, or maximum mouth opening before operation. The postoperative reduction in maximal mouth opening was significantly greater in Group C than in Group B. In Group C, the incidence of limited mouth opening was 33.3% and 20.5% 2 wk and 1 mo after operation, respectively; however, limited mouth opening resolved within 3 mo in most patients. Supratentorial craniotomies separated by short intervals can increase the risk of limiting the mandibular opening, which may result in a difficult intubation. Careful preoperative assessment of the airway is mandatory if patients have previously undergone temporal or frontotemporal craniotomy.

Adult↗
PubMed1996

Effect of isoflurane on motor-evoked potentials induced by direct electrical stimulation of the exposed motor cortex with single, double, and triple stimuli in rats.

BACKGROUND: The clinical application of intraoperative motor-evoked potentials (MEPs) has been hampered by their sensitivity to anesthetics. Recently, to overcome anesthetic-induced depression of myogenic MEPs, multiple stimulus setups with a paired or a train of pulses for stimulation of the motor cortex were reported. However, the effects of anesthetics on MEPs induced by these stimulation techniques are unknown. METHODS: Bipolar electrical stimulation of the left motor cortex was carried out in 15 rats anesthetized with thiopental while the compound muscle action potentials were recorded from the contralateral hind limb. After recording of the MEP in response to the single-shock stimulation of the motor cortex, paired pulses (double pulses) or a train of three pulses (triple pulses) with an interstimulus interval of each pulse at 0.3, 0.5, 1.0, 1.5, and 2.0 ms were applied. After control MEP recording, isoflurane was administered at a concentration of 0.25 minimum alveolar anesthetic concentration (MAC), 0.5 MAC, 0.75 MAC, and 1.0 MAC, and the effects of isoflurane on the MEPs induced by single, double, and triple pulses were evaluated. RESULTS: In all animals, distinct baseline MEPs were recorded. During the administration of 0.25 MAC and 0.5 MAC isoflurane, MEPs induced by stimulation with a single pulse could be recorded in 87% and 33% of animals, respectively, and MEP amplitude was significantly reduced in a dose-dependent manner. During the administration of 0.75 MAC isoflurane, MEPs after single-pulse stimulation could not be recorded in any animals. By stimulating with paired or triple pulses, the success rate of MEP recording and MEP amplitude significantly increased compared with those after single pulse before and during the administration of isoflurane. Both the success rate of MEP recording and MEP amplitude after double- and triple-pulse stimulation decreased significantly in a dose-dependent manner during the administration of isoflurane. CONCLUSIONS: Application of double or triple stimulation of the motor cortex increases the success rate of MEP recording and its amplitude during isoflurane anesthesia in rats. However, these responses are suppressed by isoflurane in a dose-dependent manner.

Action Potentials↗
PubMed1996

Brain SPECT of Creutzfeldt-Jakob disease.

SPECT imaging with I-123 IMP or Tc-99m HMPAO was performed in two patients with Creutzfeldt-Jakob disease to evaluate abnormalities in brain perfusion. In the first patient, there was decreased perfusion of the left frontal, parietal, and temporal lobes. CT and MRI were negative. In the second patient, there was patchy perfusion and slightly decreased perfusion of the right hemisphere. MRI revealed slight brain atrophy and bilateral high intensity areas in the basal ganglia on T2 weighted images. Subsequent SPECT imaging revealed severely decreased perfusion of the entire brain. Subsequent MRI demonstrated severe brain atrophy.

Aged↗
PubMed1996

Impaired compensatory adaption to B-cell mass reduction in young spontaneously hypertensive rats (SHR).

The aim of this study was to examine the effect of insulin resistance on B-cell function and replication. To this end insulin-resistant spontaneously hypertensive rats (SHR) and age-matched normotensive Wistar-Kyoto rats (WKY) as a control were subjected to 90% pancreatectomy (Px) or sham operation at the age of 4 weeks. Islet function and regeneration were examined 4 weeks after surgery. Plasma glucose levels were higher in SHR than in WKY 4 weeks after Px (488 +/- 30 vs. 395 +/- 31 mg/dl; p < 0.01). In sham-operated animals, plasma glucose responses to intravenous injections of glucose (0.5 g/kg body weight) were much higher in WKY than in SHR, while plasma insulin responses were greater in SHR than in WKY. There was no insulin response to glucose in either strain of Px rats. In sham-operated rats, the insulin content of the remnant equivalent pancreas (4.6 +/- 0.8 vs. 3.0 +/- 0.3 micrograms; p < 0.05) and whole pancreas (62.2 +/- 2.8 vs. 53.3 +/- 2.1 micrograms; p < 0.05) were greater in SHR than in WKY. However, the insulin content was lower in SHR than in WKY (1.9 +/- 0.3 vs. 2.5 +/- 0.7 micrograms; p < 0.05) 4 weeks after Px. Fibrotic degeneration of pancreatic islets was greater in Px-SHR than in Px-WKY. These data suggest that the B cells of SHR are more vulnerable to reduction of islet mass than those of WKY. A diminished capacity for islet cell regeneration in SHR may be linked to insulin resistance presented in this animal model of hypertension.

Adaptation, Physiological↗