Biomedical subjects

H Furuya

Publications and source records attributed to H Furuya.

At least 127 records · Page 7Linked to original sources

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↗

PubMed1997

[A case of incomplete Kearns-Sayre syndrome with a stroke like episode].

A 32-year-old woman developed chronic progressive hearing impairment, trunkal ataxia, bilateral ptosis and external ophthalmoplegia. She also showed slowly progressive mild to moderate proximal dominant muscle weakness and atrophy. ECG showed incomplete right bundle branch block. An aerobic exercise test showed abnormal blood lactate elevation and muscle biopsy revealed ragged-red fibers in addition to the myopathic change. Analysis of mitochondrial DNA extracted from biopsied muscle and fibroblast samples revealed a 1,758bp deletion from the cytochrome b to ND6 coding regions. Common mutations in tRNALeu(UUR) coding region to the mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) were not present. She was diagnosed as having incomplete Kearns-Sayre syndrome (KSS). Since the age of 35, she developed complex partial seizure attacks with secondary generalization frequently and at the age of 42, she had a severe generalized seizure with delayed consciousness loss followed by left hemiplegia. MRI showed wide T2-high signal lesions in the right temporo-parieto-occipital area. The proton MR-spectroscopy showed prominent increase of lactate beyond the lesions detected by MRI, indicating diffuse aerobic metabolic dysfunction in the central nervous system. We reviewed two other KSS cases with a stroke like episode, who also had epilepsy and large deletion but no tRNALeu(UUR) mutation, in mitochondrial DNA. Patients with KSS who have seizure may develop the stroke-like episode as seen in MELAS patients.

Adult↗

PubMed1996

Src kinase plays an essential role in integrin-mediated tyrosine phosphorylation of Crk-associated substrate p130Cas.

A novel signaling molecule p130Cas has been shown to undergo tyrosine phosphorylation in response to integrin-mediated cell adhesion. In this study, we have attempted to identify kinases that mediate Cas phosphorylation in integrin signaling by examining various mutant cell lines that do not express either p125FAK, c-Scr, c-Fyn or c-Abl. We found that deficiency of c-Src but not of other kinases completely abrogated integrin-mediated Cas phosphorylation. Importantly, paxillin phosphorylation was not compromised in each mutant cell line examined. These results suggest that c-Src primarily mediates adhesion-dependent Cas phosphorylation. As for paxillin phosphorylation, there may exist substantial redundancy amongst multiple kinases. Finally, adhesion-induced Cas phosphorylation resulted in its association with c-Crk adapter protein via the Crk-SH2 domain. Thus, Cas plays a role in the transmission of integrin-initiated signals through tyrosine phosphorylation and subsequent binding to c-Crk.

3T3 Cells↗

PubMed1996

Chronic intestinal pseudoobstruction associated with autoantibodies against proliferating cell nuclear antigen.

Autoantibodies against proliferating cell nuclear antigen (PCNA) have been detected almost exclusively in sera from patients with systemic lupus erythematosus (SLE). Because of the extremely low prevalence of anti-PCNA, however, it has been difficult to establish its disease specificity and clinical associations. We present 2 cases in which patients with anti-PCNA developed severe gastrointestinal dysfunction that led to chronic intestinal pseudoobstruction. Neither patient had manifestations suggestive of SLE. Although sclerodermatous skin changes were minimal or absent in these patients, physical and radiographic findings indicated that systemic sclerosis was a likely cause of the gastrointestinal dysfunction. The similarity of the clinical features in these patients implies that the unusual detection of this unique autoantibody may not be a coincidence.

Autoantibodies↗

PubMed1996

Additional mechanisms of nafamostat mesilate-associated hyperkalaemia.

OBJECTIVE: Nafamostat mesilate, a potent protease inhibitor, is widely used for the treatment of pancreatitis, disseminated intravascular coagulation and as an anticoagulant in haemodialysis. However, hyperkalaemia associated with nafamostat mesilate has been reported. It is thought to be due to decreased urinary potassium excretion, of the drug suppression of aldosterone secretion, and a direct inhibitory action on the apical Na+ conductance in collecting ducts. We have seen two cases of nafamostat mesilate associated-hyperkalaemia, which indicated that extrarenal potassium imbalance might play a role in inducing hyperkalaemia. METHODS: To examine the effect of nafamostat mesilate on potassium transport in erythrocytes in vitro, 86RbCl uptake was measured in red blood cells from eight healthy volunteers. RESULTS: Nafamostat mesilate and a metabolite, 6-amidino-2-naphthol, at concentrations of 10(-4) and 10(-3) M, respectively, significantly, suppressed potassium influx whilst another metabolite, p-guanidino-benzoic acid, had no effect. The inhibitory action of nafamostat mesilate was not affected by various inhibitors. CONCLUSION: Nafamostat mesilate and its metabolite, 6-amidino-2-naphthol, suppressed potassium influx in erythrocytes by inhibition of a Na-K ATPase dependent pathway, which was not inhibited by amiloride, barium, nor by frusemide (furosemide).

Adult↗

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

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

Nitric oxide involvement in hypoxic dilation of pial arteries in the cat.

BACKGROUND: The reactivity of cerebral arteries to different stimuli varies according to vessel size. Whether nitric oxide mediates hypoxic vasodilation is controversial. The authors considered this question by measuring the diameter of pial arteries and arterioles with or without exposure to the nitric oxide synthase inhibitor, N omega-nitro-L-arginine methyl ester (L-NAME). METHODS: The cranial window technique, combined with microscopic video recording, was used in an experiment involving 20 cats anesthetized with fentanyl and midazolam. The diameters of pial arteries and arterioles were measured under the following conditions: (1) normoxia (PaO2 > 100 mmHg); (2) hypoxia (PaO2 < 45 mmHg); (3) normoxia with L-NAME infusion; and (4) hypoxia with L-NAME infusion. Changes in vessel diameter were analyzed with respect to artery size. RESULTS: Under hypoxic conditions, arteries and arterioles smaller than 200 microns were dilated significantly (P < 0.05). In arterioles smaller than 200 microns, L-NAME attenuated this hypoxic vasodilation (P < 0.05). In contrast, under normoxic conditions, L-NAME caused significant vasoconstriction in arteries larger than 100 microns but not in arteries smaller than 100 microns. CONCLUSIONS: Arteries and arterioles smaller than 200 microns are dilated by hypoxia, and nitric oxide contributes to this process. Nitric oxide synthesis may also be related to the regulation of resting vascular tone in arteries larger than 100 microns.

Animals↗

PubMed1996

Preoperative predictors of reduction in arterial blood pressure following dural opening during surgical evacuation of acute subdural hematoma.

To determine preoperative predictors of blood pressure reduction following dural opening during surgical evacuation of hematoma, we retrospectively assessed preoperative variables including clinical profile, hemodynamic parameters, neurological findings, and computed tomography (CT) scan results in 56 patients with traumatic acute subdural hematoma (ASDH). Patients were divided into two groups according to the degree of changes in mean arterial pressure (MAP) in response to dural opening. Group A (n = 18) had a MAP reduction > 20%, and group B (n = 38) had a MAP change within +/- 20% of baseline values (5 min before opening the dura). Significant relationships were found between MAP reductions > 20% and Glasgow coma scale (GCS) scores, abnormalities of the mesencephalic cistern on CT scan, pupillary abnormalities, and degree of midline shift. Low GCS score, absence of the mesencephalic cistern on CT scan, and bilaterally dilated pupils were particularly strong predictors of this amount of blood pressure reduction. The clinical outcomes of patients with MAP reduction > 20% following dural opening during surgery were significantly poorer than those of patients without this amount of blood pressure reduction. Our findings suggest that blood pressure reduction following opening of the dura in patients undergoing surgical evacuation of hematoma for traumatic ASDH may be predicted by careful preoperative assessment of neurological and CT scan findings.

Acute Disease↗

PubMed1996

Increased serum human granulocyte colony-stimulating factor (G-CSF) levels following intravenous infusion of high-dose methylprednisolone.

Serum granulocyte colony-stimulating factor (G-CSF) level were measured for 24 h in 6 patients with hematological disorders and two patients with Graves' disease associated with malignant exophthalmos after iv infusion of high-dose methylprednisolone (HDMP) (20 mg/kg BW) for 2 h starting at 0900 h. Saline solution (500 ml) was infused iv for 2 h as a control on two days before starting the HDMP therapy. Serum G-CSF levels increased with the mean peak values at 4 h after the HDMP therapy (mean +/- SD: 488.1 +/- 125.8 pg/ml vs. saline control 74.4 +/- 21.9 pg/ml, P < 0.01). Circulating absolute neutrophil counts (ANC) also increased with the mean peak values at 24 h after the HDMP (6,057 +/- 1,460 / microliters vs. saline control 2,007 +/- 390 / microliters, P < 0.025). These findings indicate that glucocorticoid has a stimulating effect on G-CSF release and that the increased G-CSF release could be involved, at least partly, in neutrophilia induced by glucocorticoid.

Adult↗

PubMed1996

A mRNA for membrane form of guanylyl cyclase is expressed exclusively in the testis of the sea urchin Hemicentrotus pulcherrimus.

A cDNA clone encoding the membrane form of guanylyl cyclase was isolated from a Hemicentrotus pulcherrimus testis cDNA library and its nucleotide sequence was determined. The cDNA was 4123 bp long and an open reading frame predicted a protein of 1125 amino acids including an apparent signal peptide of 21 residues; a single transmembrane domain of 25 amino acids which divides the mature protein into an amino-terminal, extracellular domain of 485 amino acids and a carboxyl-terminal, intracellular domain of 594 amino acids. Three potential N-linked glycosylation sites were present in the extracellular domain. Northern blot analysis of poly(A)+RNA from testes, ovaries, eggs and embryos at various developmental stages showed that the cDNA encoding guanylyl cyclase hybridized to a mRNA of 4.4 kb from the testes. We developed a large scale purification method of the phosphorylated (131 kDa) and dephosphorylated (128 kDa) forms of the membrane-bound guanylyl cyclase from H. pulcherrimus spermatozoa. The purified 131 kDa and 128 kDa forms of the guanylyl cyclase contained 26.0 +/- 1.3 and 4.3 +/- 0.7 moles of phosphate per mol protein (mean +/- S.D.; n = 6), respectively. The amino-terminal amino acids of both the 131 kDa and 128 kDa forms of the guanylyl cyclase could not be detected, suggesting that they were blocked.

Amino Acid Sequence↗

PubMed1996

Clinically safe dosage of felypressin for patients with essential hypertension.

Hemodynamic changes were evaluated in patients with essential hypertension when felypressin of various concentrations was administered. The parameters studied were systolic pressure, diastolic pressure, heart rate, left ventricular systolic phase, and endocardial viability ratio. Results showed that blood pressure tended to increase, and the value of 1/pre-ejection period2 (PEP2) tended to decrease, upon administration of 3 ml of 2% propitocaine containing 0.06 international units/ml (IU/ml) of felypressin. Significant increase of blood pressure and decrease in 1/PEP2 was noted upon administration of 3 ml of anesthetic solution containing 0.13 IU/ml of felypressin. No ischemic change of the myocardium was detected even with the highest felypressin concentration (3 ml of 2% propitocaine containing 0.25 IU/ml of felypressin). These results suggest that the clinically safe dosage of felypressin for patients with essential hypertension is approximately 0.18 IU. This amount is equivalent to 6 ml of 3% propitocaine with 0.03 IU/ml of felypressin, which is a commercially available local anesthetic for dental use. It seems that the decrease in 1/PEP2 that occurred during blood pressure increase was due to the increase in afterload caused by contraction of the arterioles. Although in the present study no ischemic change was noted, special care should be taken to prevent myocardial ischemia in patients with severe hypertension.

Analysis of Variance↗

PubMed1996

[The effect of work-related stress with change of working conditions for workers with alcohol drinking habit and liver disorder].

To evaluate the relationship between working conditions and workers' health, particularly the effect of work-related stress with change of working conditions for those with alcohol drinking habit and liver disorder, we analyzed physiological examination data and a questionnaire survey including the Japanese version of Karasek's Job Content Questionnaires (JCQ) on work-related stress, working hours, sleeping hours, alcohol consumption and cigarette smoking among male workers of a car manufacturing plant, who engaged in car sales work temporarily and then returned to manufacturing work. In the physiological examination data, the values of body mass index (BMI), GOT, GPT, gamma-GTP, TG and T-CHO rose and the prevalence of obesity and liver disorder increased during the term of car sales work. Comparing the term of car sales work with the term of car manufacturing work, the number of habitual drinkers and heavy smokers increased during the former and decreased during the latter. Increased alcohol consumption and cigarette smoking were also noted during the term of car sales work. Logistic regression analysis showed that the odds ratio of decreasing 'decision latitude (DL)' as work-related stress was statistically significant for increased alcohol consumption. The increased alcohol consumption probably contributing to the prevalence of liver disorder was assumed to be associated with work-related stress due to change of work conditions. Workers who showed liver disorder strongly complained of work-related stress, and it was assumed that the work-related stress was related to liver disorder. Longitudinal observations which take into account work-related stress, alcohol drinking habit and liver disorder must be well planned and personal traits of work-related stress always be taken into consideration.

Adult↗

PubMed1996

[Apoptosis and cell growth fraction in normal, dysplastic and neoplastic squamous epithelium of uterine cervix].

The populations of cells in apoptosis as well as proliferating cycle were examined in normal cervical epithelium, dysplastic change, carcinoma in situ and invasive carcinoma. The percentage of apoptotic cells (% Apo) decreased with the neoplastic change and was significantly lower in carcinoma in situ group than in the dysplasia group. Conversely, the percentage of cells in proliferating cycle (% GF) increased with the neoplastic change and was significantly higher in the dysplasia group than in the normal group. In the dysplasia group, the % Apo was lower in cases with HPV 16 infection or with bcl-2 expression, and the % GF was higher in cases with p53 expression. In conclusions, the decrease in apoptosis may reflect the atypical change in cervical epithelial cells during their neoplastic change, and the proliferative activity in neoplastic lesion was found when the cervical epithelium with dysplastic change was transformed to the carcinoma in situ. Furthermore, these events were related to the p53 accumulation and bcl-2 expression following the HPV 16 infection.

Apoptosis↗

PubMed1996

[Effects of prostacyclin (PGI2) on pial vessel diameter and carbon-dioxide reactivity in cats].

We studied the effects of prostacyclin (PGI2) on the pial vessel diameter (D) and CO2 reactivity in cats. Nineteen cats, weighing 1.6-4.0 kg, were divided into two groups; PGI2 administration group (n = 10) and the control group (n = 9). The animals were anesthetized with midazolam, fentanyl, pancuronium and nitrous oxide/oxygen and ventilated mechanically. The pial vessels diameter (D) was classified into 4 groups (D < 50 microns, 50 < or = D < 100 microns, 100 < or = D < 200 microns, D > 200 microns). The vascular dynamics was examined through the closed cranial window with intravital epifluorescence microscopy on which a video camera was mounted. The measurements were carried out under the steady state of hypo-, normo-, and hypercarbia, respectively and the CO2 reactivity (delta %D/delta CO) was calculated. Under the induced hypotension with PGI2 (30% reduction in mean arterial pressure), pial vessels were significantly dilated, but there was no change in CO2 reactivity in terms of vessels diameter. The vessels with diameters of less than 50 microns were more dilated compared with those with larger diameters. We concluded that pial arterioles were dilated with PGI2 but it had no effects on CO2 reactivity.

Animals↗

PubMed1996

[A case of orbital myositis with blepharoptosis demonstrating the swelling of superior levator palpebrae muscle on magnetic resonance images].

A 51-year-old woman developed diplopia and left blepharoptosis with an insidious onset. On orbital MRI, the extraocular and a left superior levator palpebrae muscles were swollen and enhanced by gadolinium, suggesting orbital myositis. The left blepharoptosis was improved two weeks and the swelling of superior levator palpebrae muscle one month after prednisolone administration. This is the first report that the lesion of superior levator palpebrae muscle was demonstrated by MRI in orbital myositis.

Administration, Oral↗