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Biomedical subjects

K Saitoh

Publications and source records attributed to K Saitoh.

At least 145 records · Page 8Linked to original sources
PubMed1996

The burst firing in the layer III and V pyramidal neurons of the cat sensorimotor cortex in vitro.

We identified the burst and single-spiking cells, and the repetitive bursting cells in layers III and V of the cat sensorimotor cortex with intracellular recording and staining techniques. Both types of the bursting cells were found in 22.7% of the recorded layer V neurons and in 23.1% of the recorded neurons in layer III. The bursting cells were characterized by the prominent afterdepolarization (ADP) which was usually reaching the threshold depolarization. Intracellular staining revealed that the morphology of the bursting cells was not so different from that of the regular-spiking cells in the cat.

Adenosine Diphosphate↗
PubMed1996

Failed spinal anaesthesia: cause identified by MRI.

PURPOSE: To determine the cause of failed spinal anaesthesia, magnetic resonance images of the lumbar spine were examined. CLINICAL FUTURES: A 28-yr-old woman, scheduled for closure of a rectal fistula under spinal anaesthesia, hyperbaric tetracaine 12.5 mg injected into the subarachnoid space at L3-4 repeatedly resulted in restricted sacral spread. Magnetic resonance imaging showed that the cylindrical dimension of the lumbar spinal canal was wider than in normal subjects, suggesting a larger volume of CSF within the dural sac below the termination of the cord. The summit of the lumbar convexity was located at L3, which was more cephalad than the L3-4 puncture site. CONCLUSION: The uncommon anatomical characteristics of the lumbar spinal canal identified by magnetic resonance imaging were considered to be the reason for the restricted sacral spread observed repeatedly in this patient.

Adult↗
PubMed1996

Sevoflurane anaesthesia for a patient with adult polyglucosan body disease.

PURPOSE: Adult polyglucosan body disease (APBD) is a rare neurological disorder of unknown cause characterized by four manifestations: upper motor neuron signs, peripheral neuropathy with motor and sensory loss, urinary incontinence, and dementia. The purpose of this report is to present a patient with APBD anaesthetized successfully with sevoflurane and nitrous oxide. CLINICAL FEATURE: A 51-yr-old man with APBD was scheduled for haemorrhoidectomy. Paraesthesia, dysaesthesia, distal muscular atrophy and fasciculation were recognized in the extremities. Dementia, bulbar paralysis and respiratory insufficiency were basent. Anaesthesia was induced with inhalation of sevoflurane and nitrous oxide, and the trachea was intubated without the use of muscle relaxants. Maintenance of anaesthesia was performed with sevoflurane (inspired concentration: 1.5-2.5%) and nitrous oxide (50%). Emergence from anaesthesia and the postoperative course were uneventful, and no exacerbation of neurological signs and symptoms was recognized. No postoperative analgesia was required. CONCLUSION: General anaesthesia and tracheal intubation with sevoflurane and nitrous oxide provided safe anaesthesia for a patient with APBD.

Anesthesia↗
PubMed1996

Expression of metastasis suppressor gene product, nm23 protein, is not inversely correlated with the tumour progression in human malignant melanomas.

An inverse correlation between the nm23 RNA level and tumour progression of melanocytes has been reported. To elucidate whether the expression of nm23 gene product in malignant melanoma is also inversely correlated with metastatic potential, conventional prognostic parameters or the tumour suppressor protein p53, immunohisto-chemical studies using a monoclonal antibody against nm23-H1 protein were performed on 138 benign and malignant melanocytic tumours. The expression of nm23 protein was compared with that of p53 protein and conventional clinicopathological prognostic factors. The nm23 protein level in benign melanocytes and metastatic melanoma cells was also studied by Western blot analysis. No significant difference regarding the protein was observed between naevi and melanomas, either at histological or protein levels. The expression correlated with local recurrence within 1 year after surgery, level of invasion and tumour thickness, but no parallels were observed between the nm23 and p53 proteins, suggesting that gene is regulated by independent mechanisms, although located on the same chromosome. There was no inverse correlation between the nm23 protein and melanoma metastasis which suggested that the nm23 protein does not appear to be lost during melanoma metastasis.

Adult↗
PubMed1996

Convulsions associated with epidural analgesia during sevoflurane anaesthesia.

A three-year-old girl who underwent an operation for adrenal neuroblastoma was anaesthetized with sevoflurane and epidural analgesia. In the immediate recovery period she had convulsions. The convulsions were successfully treated with thiopentone and sevoflurane, there were no neurological sequelae. The convulsions were considered to be a manifestation of mepivacaine toxicity because of a high plasma mepivacaine concentration. Complications of paediatric regional analgesia and manifestations of mepivacaine toxicity under sevoflurane anaesthesia are discussed.

Analgesia, Epidural↗
PubMed1996

Anatomical configuration of the spinal column in the supine position. III. Comparison of adolescent and adult volunteers.

To clarify the anatomical configuration of the spinal column in the adolescent in the supine position, we have studied 10 adolescent (13-17 yr) and 10 adult (26-38 yr) volunteers using magnetic resonance imaging. T1-weighted sagittal midline magnetic resonance images of the spinal column were obtained with subjects in the supine position. The maximum angles of decline of the lumbar spinal canal did not differ between the adolescent (mean 13.6 (SD 3.3) degrees) and adult (12.4 (3.8) degrees) groups. The maximum angles of incline of the upper thoracic spinal canal were smaller in the adolescent group (15.9 (4.7) degrees) than in the adult group (26.4 (5.8) degrees). The median highest point of the lumbar spinal canal was located at L4 (range L3-4 to L4-5) in both groups. The lowest points of the thoracic spinal canal in the adolescent and adult groups were located at T8-9 (T7 to T9) and T8 (T6-7 to T9), respectively. This study showed that thoracic kyphotic curvature in adolescents was reduced significantly in the supine position compared with that in adults. This minimized thoracic kyphosis may explain, in part, the enhanced cephalad spread of subarachnoid hyperbaric anaesthetic solutions in adolescents.

Adolescent↗
PubMed1996

Soft tissue anatomy within the vertebral canal in pregnant women.

To clarify pregnancy-induced changes in soft tissue anatomy within the vertebral canal, we have studied magnetic resonance (MR) images of the lumbar spine in three women. In each subject, T2-weighted axial MR images were obtained both before pregnancy and at 32 weeks' gestation, and the paired images were compared. The extradural venous plexus was engorged significantly in supine parturients. In addition, the engorged extradural venous plexus displaced the dura away from the wall of the vertebral canal in a posterior direction, which resulted in a decrease in the volume of the cerebrospinal fluid in the dural sac. These findings confirmed the long-held concept that the engorged extradural venous plexus in supine parturients decreases the effective capacity of the extradural and subarachnoid spaces.

Adult↗
PubMed1996

Inflammatory changes after extradural anaesthesia may affect the spread of local anaesthetic within the extradural space.

We have assessed cephalad spread of analgesia in 491 patients undergoing extradural anaesthesia at the L2-3 or L3-4 interspace. Patients were classified into one of three groups based on the number of previous lumbar extradural anaesthesia procedures: none (group I, n = 339), one (group II, n = 82), and two or more (group III, n = 70). Cephalad spread of analgesia was greater in group I than in groups II and III, regardless of the puncture site. In addition, we examined the extradural space using a flexible extraduroscope in 32 patients who were excluded from the analysis of spread. Extraduroscopy showed the extradural space to be patent in patients with no history of prior lumbar extradural anesthesia, but it was not clearly identified in patients who had received extradural anaesthesia one or more times because of aseptic inflammatory changes, including proliferation of connective tissue, adhesions between the dura mater and the ligamentum flavum, granulation and changes in the ligamentum flavum. Extradural anaesthesia may cause aseptic inflammatory changes in the extradural space which may reduce the spread of analgesia.

Adult↗
PubMed1996

Acid-base state of cerebrospinal fluid during pregnancy and its effect on spread of spinal anaesthesia.

To assess the possible relationship between changes in acid-base state of cerebrospinal fluid (CSF) and enhanced spread of spinal anaesthesia during pregnancy, we have measured CSF pH, carbon dioxide tension (PCO2) and HCO3- values in 73 women undergoing spinal anaesthesia with hyperbaric amethocaine 8 mg. Patients were allocated to one of four groups according to gestational period: non-pregnant group (n = 13), first trimester group (8-13 weeks, n = 19), second trimester group (14-26 weeks, n = 11) and third trimester group (27-39 weeks, n = 30). The pH of the CSF was greater in the second and third trimester groups than in the non-pregnant group. CSF PCO2 decreased by 0.53-0.8 kPa throughout pregnancy. CSF HCO3- was decreased throughout pregnancy. Overall, no clinically significant correlation was found between maximum cephalad spread of analgesia and CSF pH, PCO2 or HCO3-. We conclude that pregnancy-induced changes in acid-base state of CSF have little effect on the spread of spinal anaesthesia, although there is a clinically different spread of spinal anaesthesia between non-pregnant and pregnant states.

Acid-Base Equilibrium↗
PubMed1996

Sevoflurane is equivalent to isoflurane for attenuating bupivacaine-induced arrhythmias and seizures in rats.

The effects of sevoflurane on bupivacaine toxicity have not been defined. The purpose of this study was to investigate the effects of sevoflurane and isoflurane on bupivacaine-induced arrhythmias and seizures in rats. Thirty-seven Sprague-Dawley rats received bupivacaine intravenously at a constant rate of 2 mg.kg-1.min-1 until both arrhythmias and seizures occurred while electrocardiogram (ECG) and electroencephalogram (EEG) recordings were made. The cumulative doses of bupivacaine inducing arrhythmias and seizures were determined in the presence of 1 minimum alveolar anesthetic concentration (MAC) of sevoflurane (sevoflurane group, n = 14) or isoflurane (isoflurane group, n = 10) and in the absence of anesthetic (control group, n = 13). The cumulative doses of bupivacaine inducing arrhythmias and seizures were larger in the sevoflurane and isoflurane groups than in the control group and were similar in the sevoflurane and isoflurane groups. These results indicate that sevoflurane and isoflurane attenuate bupivacaine-induced arrhythmias and seizures in rats.

Anesthetics, Inhalation↗
PubMed1996

Effects of thoracic vs. lumbar epidural anaesthesia on systemic haemodynamics and coronary circulation in sevoflurane anaesthetized dogs.

BACKGROUND: Although many investigators reported changes in coronary circulation during thoracic epidural anaesthesia (TEA), no previous studies have attempted to compare it with lumbar epidural anaesthesia (LEA) concerning coronary circulation. Our aim was to compare effects of TEA on systemic haemodynamics and coronary circulation with those of LEA in anaesthetized dogs. METHODS: In dogs receiving 1.5% sevoflurane, 2% lidocaine (0.1 ml kg-1) was injected into the epidural space via an epidural catheter inserted at either the T7-T8 (TEA group, n = 8) or L5-L6 (LEA group, n = 8) interspace, and the same dose was repeated again 30 min later. RESULTS: Heart rate and maximum left ventricular dP/dt decreased in the TEA group but were unchanged in the LEA group. Decreases in mean arterial pressure were found for both groups, and they were more substantial in the TEA than in the LEA group. Decreases in left ventricular minute work index were found for both groups, and they tended to be more substantial in the TEA than in the LEA group. Coronary perfusion pressure and blood flow decreased in both groups. Calculated coronary vascular resistance increased in the TEA group but was unchanged in the LEA group. CONCLUSION: The most significant difference between TEA and LEA concerning coronary circulation was characterized by an increase in coronary vascular resistance in the TEA group, which was not present in the LEA group. The increase in coronary vascular resistance caused by TEA may be explained by a coronary vasoconstriction caused by a lower myocardial oxygen demand.

Anesthesia, Epidural↗
PubMed1996

Electron microscopic study of chronic eosinophilic pneumonia.

Two cases of chronic eosinophilic pneumonia were examined electron microscopically to study the role of eosinophil granulocytes. Eosinophils, together with macrophages and lymphocytes, were observed to have infiltrated prominently in the lung tissues of the two cases. Degeneration and necrosis of pneumocytes were observed, and denuded basement membranes and destroyed alveolar structures were occasionally found. In the alveolar septa, swelling of the endothelial cells of the blood capillaries, edema of the stroma and fibrin deposition were observed. Eosinophils, released eosinophil granules and macrophages phagocytosing eosinophil granules were found frequently near the degenerated and necrotic alveolar tissues. These findings suggest that the tissue injuries were induced by the cytotoxic effects of the eosinophil granules.

Adult↗
PubMed1996

[Establishment of reference intervals and physiological parameters for 13 serum proteins in healthy Japanese adults].

Using a nephelometry with a new calibrator in which values were assigned from EU/CRM470, a new international reference preparation, we have established for the first time the reference intervals of 13 different serum proteins in Japanese adults. Based on the NCCLS guideline C28-P, a new statistical and concrete procedure was revised and used for this study. It is clearly shown here that standardisation of serum proteins can be possible under the qualified assay system, making it possible to share the reference intervals among laboratories under well-controlled quality assurance. New aspects of serum protein variations were discovered in relation to physiologic changes and life styles.

Adult↗
PubMed1996

[Diffuse panbronchiolitis with P-ANCA-positive arteritis and necrotizing glomerulitis].

A 53-year-old man was admitted to our hospital with a skin eruption, a high fever, and diplopia in April of 1992. He had been given a diagnosis of diffuse panbronchiolitis in 1981. After administration of erythromycin began in 1987, symptoms and chest roentgenographic findings gradually improved. Arteritis of peribronchial muscular arteries with medial destruction was seen in lung biopsy specimens, and periglomerular granulomatous inflammation and necrotizing glomerulitis were seen in renal biopsy specimens. P-ANCA was found, but a test for cytoplasmic ANCA (which is the most specific antigen of Wegener's granulomatosis) was negative. Chronic pulmonary infection due to diffuse panbronchiolitis might have formed ANCA, which may have caused the vasculitis in this patient.

Antibodies, Antineutrophil Cytoplasmic↗