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Biomedical subjects

J Harada

Publications and source records attributed to J Harada.

At least 73 records · Page 4Linked to original sources
PubMed1991

Efficacy of nine heat and moisture exchangers for intraoperative airway heat conservation.

The performance of heat and moisture exchangers (HMEs) were clinically evaluated for the effectiveness of intraoperative heat conservation. Ten groups of patients were studied, nine groups with commercially available HMEs (Gibeck Humidvent 1, Terumo Brethaid, Portex Thermovent 600, NMI Pneumoist 2, Pall HME15-22, Gambro Engström Edith 1000, Gambro Engström Edith 1500, Gambro Engström Edith Flex and Siemens Servo Humidifier 153) and a control group with no HMEs. Deep temperature of the forehead (107 patients) and heat and humidity at the airway (55 patients) were measured. The temperature decrease in one hour, the total body heat loss, the temperature and absolute humidity of inspired gas and the heat loss from the airway were much better for all groups with HMEs than for the group with no HMEs, and the nine HMEs had different efficiency. There were significant correlations between the index values of body temperature and the index values of heat and humidity at the airway. In conclusion, HMEs were useful devices for preventing heat loss from the airway and maintaining body temperature.

Adult↗
PubMed1991

Modified thermal diffusion flow probe for the continuous monitoring of cortical blood flow.

A small thermal diffusion flow probe has been developed to monitor the dynamic changes in cerebral blood flow in small animals. Constantan wire was used as a heat source to make a miniature probe. The pair of thermocouples used to detect the heat gradient between two gold plates was elongated to avoid heat conduction between them, and this improvement allowed us to make quantitative measurements. After several basic experiments, local cerebral blood flow was measured simultaneously, using both the modified thermal probe and the hydrogen clearance method in four rabbits. A close relationship was obtained between the local cerebral blood flow values measured by hydrogen clearance (F, ml/100g/min) and the reciprocal of the thermocouple voltage (1/V;1/mV). The regression line was F = 29111(1/V - 1/226), (r = 0.92, P less than 0.001). We suggest that the modified thermal probe is a reliable and quantitative means of measuring flow. In addition, another probe modified for clinical use was evaluated. Continuous monitoring of local cerebral blood flow in postoperative patients was performed, and some illustrative cases are described.

Aged↗
PubMed1991

Differences in critical cerebral blood flow with age in swine.

Normal cerebral blood flow (CBF), critical CBF at a flat reading of the electroencephalogram (EEG), and reversibility of the flat EEG after reperfusion were investigated in a total of 59 pigs, including seven newborns (1 to 3 days of age), 38 juveniles (1 month old), and 14 adults (7 months old). The CBF was determined by the hydrogen clearance method; the EEG was recorded continuously and a power spectrum analysis was performed. Cerebral ischemia was produced by occlusion of both common carotid arteries and induction of hypotension (approximately 50 mm Hg). The flat EEG reversibility was investigated for 3 hours after reperfusion. As parameters of brain development, the neuronal density and the time at which the S-100 protein appeared in the brain were examined. Normal CBF was highest in neonatal pigs and decreased with age. The critical CBF at a flat EEG was lowest in newborn pigs and was elevated with development of the brain. Tolerance against cerebral ischemia was greatest in newborn pigs.

Aging↗
PubMed1991

[Comparison of the M1-blocker with the H2-blocker regarding their effects on gastric pH and viscosity under general anesthesia].

In a prospective, controlled, randomized trial measuring the gastric juice pH and viscosity, 30 patients under general anesthesia received M1-blocker; pirenzepine or H2-blocker; ranitidine. The gastric juice pH value was significantly higher (P less than 0.05) both in the pirenzepine and the ranitidine group than in the control group. While in the pirenzepine group the viscosity of gastric juice was unchanged, in the ranitidine group it was reduced. The results suggest that pirenzepine offers more effective prophylaxis against stress ulcer than ranitidine.

Adult↗
PubMed1990

[Usefulness of ioversol (MP-328) in angiocardiography--a multicenter comparative study with iopamidol].

A randomized, controlled study was conducted to compare the radiographic efficacy, safety and usefulness of ioversol and iopamidol in 146 patients undergoing angiocardiography at six institutions. The hemodynamic and electrocardiographic effects were clinically insignificant and comparable for both agents. Ioversol demonstrated lower incidence of adverse reactions and less heat sensation in left coronary arteriography than those with iopamidol. Overall radiographic efficacy with ioversol was slightly better than with iopamidol, according to the evaluation by both investigators and committee members. Ioversol appears to be very useful for angiocardiography. This comparative study demonstrated the value of safety and efficacy evaluation criteria suggested by the preceding clinical trial with ioversol.

Adult↗
PubMed1990

[Preliminary study and clinical evaluation method of ioversol in angiocardiography--establishment of safety evaluation parameters and reliability of radiographic quality evaluation].

A multi-center clinical study of a new nonionic iodinated contrast medium (ioversol) was performed in 26 patients undergoing left ventriculography (LVG) and coronary angiography (CAG) at four centers. The aims of this study were to try to establish a clinical evaluation method on contrast media in angiocardiography and to determine radiographic efficacy and safety of ioversol. The reliability of the method evaluating the radiographic quality of the contrast medium was also examined with statistical analysis. Excellent radiographic efficacy was observed with ioversol and morphological diagnosis was possible in all cases. The electrocardiograms (ST-segment deflection, T-wave amplitude, QT interval, corrected QT interval, arrhythmia and heart rate) and the hemodynamic parameters (left ventricular systolic and end diastolic pressures, left ventricular dp/dt max, aortic systolic and diastolic pressures) indicated no clinically significant changes. This study suggested that the monitoring of the ECGs and hemodynamic parameters for up to three minutes after injection of the contrast medium is sufficient for the evaluation in LVG and CAG, and that the monitoring in CAG during the first injection into each left and right coronary artery is also sufficient for the purpose. Heat sensation during injection was mild. A patient had a symptom of nausea after ioversol administration, but it was mild and transient and resolved spontaneously. There were no abnormal clinical laboratory data related to ioversol. The reliability of the radiographic quality evaluated by the individual clinical investigators was considered to be high and adaptable. However, the evaluation in the blinded cinefilms by the committee members involving all investigators would be more preferable for the higher objectivity. The study results suggest that ioversol is considered to be the efficacious and safe contrast medium for the cardiovascular angiography.

Adolescent↗
PubMed1990

Evidence for receptor-mediated inhibition of intrinsic activity of GTP-binding protein, Gi1 and Gi2, but not G0 in reconstitution experiments.

The receptor-mediated inhibition of intrinsic activities of GTP-binding proteins (G-proteins) was studied. Pertussis toxin (IAP)-substrate G-protein, Gi1, Gi2 or G0, was prelabeled with [alpha-32P]GDP and reconstituted with synaptic membranes of the guinea pig cerebellum in the presence of 0.02% of Chaps. Intrinsic activities of G-proteins were evaluated by the release of [alpha-32P]GDP in exchange for added GppNHp or GDP in reconstituted preparations. U-50,488H (1 nM-10 microM), a specific kappa-subtype of opioid receptor agonist, inhibited the [alpha-32P]GDP release in exchange for added 1 microM GppNHp in Gi1-reconstituted preparations in a concentration-dependent manner. On the other hand, the kappa-opioid agonist at 10 microM increases the Km values of GppNHp, but not GDP in exchange for [alpha-32P]GDP release in preparations reconstituted with Gi1 or Gi2, but not with G0. These findings indicate that kappa-opioid receptor is coupled to inhibition of intrinsic activities of Gi1 and Gi2, but not G0, in guinea pig cerebellar membranes. In addition, it was revealed that the mode of action is mediated by a decrease in affinity of GTP (or its analog) for G proteins, but not by a change in affinity of GDP.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1990

[Application of digital filtering and phase spectral analysis to middle latency response and 40Hz event related potential in central nerve system disorders].

40Hz event related potential, or 40Hz-ERP, described by Galambos in 1981 has been considered as the useful potential in predicting hearing threshold across the audiometric frequencies. Although 40Hz-ERP was reported by Galambos as the summation of middle latency responses (MLR), its origin has not been clarified. Moreover reports of the clinical use of 40Hz-ERP in patients with the neurological disorders were rare. Therefore, we recorded ABR, MLR and 40Hz-ERP in 35 patients with central nerve system disorders, or CNS disorders, and analysed the relation between central lesions and modality of MLR- or 40Hz-ERP from the view point of phase spectral analysis comparing with the digital filtered waveform analysis. For the phase spectral analysis, synchrony measure method described by Fridman in 1984 was applied to MLR and 40Hz-ERP. Following results were obtained. 1) By the digital filtered waveform analysis, the latencies of Po, Na, Pa and the amplitudes of Po, Na, Pa, Nb were recorded clearly in normal cases. In cases with the central lesions, many of them were revealed reduction of the amplitude of Po, but other parameters were not useful for the detection of CNS disorders because of their wide normal ranges. 2) The parameters of the phase spectral analysis were obtained from 17 records of the normal subjects. The SM (30 + 40 + 50Hz), which is the average of CSM 30Hz, CSM 40Hz and CSM 50Hz, was applied to MLR, and the SM (40 + 80 + 120Hz) was applied to 40Hz-ERP.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Three cases with electrocardiographic changes suggesting myocardial infarction].

We had three cases that showed electrocardiographic changes suggesting myocardial infarction during or soon after operation. All cases were elderly for open abdominal operation complicated with carcinoma or infection. They were different from typical myocardial infarction in progress of electrocardiographic changes, increase of myocardial enzyme, autopsy and so on. Kuramoto et al. reported in some cases myocardial infarction could not be recognized at autopsy in spite of electrocardiographic changes suggesting myocardial infarction during gastric operation of the elderly, and they advocated an idea of "reversible myocardial infarction". These three cases were also thought to be consistent with this disorder.

Aged↗
PubMed1989

Complex congenital cardiovascular anomalies evaluated by continuous-rotation computed tomography in children.

The slip ring and nutate/rotate configuration of the new, fourth-generation, computed tomography (CT) (TCT-900S, Toshiba Medical Company) makes it possible to scan consecutively 25 slices every 75 s. This scanner also rapidly provides hemodynamic and multiplanar reconstruction images. Studies were performed on 13 children with various forms of complex congenital cardiovascular anomalies. The findings correlated very well with those by angiocardiography and echocardiography. But the cardiac valves were difficult to scan, and combined use with echocardiography was considered to be indispensable. The rapid multiplanar reconstruction imaging is very effective in depicting coarctation of the aortic isthmus, ductus arteriosus, and hypoplasia of the great arteries in newborns and infants who have small target regions. Cine-displays of such images can clearly show ventricular and atrial septal defects. This new CT system proved effective in diagnosing complex congenital cardiovascular anomalies even in young infants.

Child↗
PubMed1989

Operative correction of a kinked duplicate origin of the vertebral artery in a patient with dizziness. Case report.

A 70-year-old woman was admitted to our hospital with complaints of severe dizziness and occipital headache. A right vertebral angiogram demonstrated a kinked, duplicated origin of the vertebral artery. Medical treatment was not effective, and an operative correction was attempted to improve the vertebral artery circulatory flow. The duplicate origin of the vertebral artery was confirmed at the time of surgery. Eight cases of duplicate origin of the vertebral artery in the literature are reviewed.

Aged↗
PubMed1989

[Operative correction of kinking and coiling at the origin of vertebral artery and stellate ganglionectomy in patients with severe vertigo and dizziness].

Bilateral vertebral angiograms were taken in 125 cases with severe vertigo and dizziness during the period between April 1983 and March 1986. Various kinds of morphological abnormalities were found. Most impressive findings were kinking and coiling at the first portion of the vertebral artery, which was corrected by operation in 54 cases out of 100 cases. This method is accompanied with stellate ganglionectomy and completed by rolling the subclavian artery forwards and downwards with ligation. The follow-up results were evaluated one to four years after operation. Symptoms were cured in 50 cases out of 54. The postoperative course was satisfactory. It was emphasized in this paper that our operation was very useful for patients with severe and recurrent vertigo.

Adult↗
PubMed1988

Aortic dissection without intimal rupture: diagnosis with MR imaging and CT.

Fourteen patients with aortic dissection without intimal rupture were examined by means of magnetic resonance (MR) imaging, computed tomography (CT), or both. MR imaging showed a marginal high-intensity area along the aortic wall, while CT showed a nonopacified crescentic area along the aortic wall. These areas decreased in size within a short period and normalized after 1 year. Two autopsies demonstrated intramural hemorrhage without intimal tears. The dissected lumen seen in these cases is believed to represent intramural hemorrhage due to rupture of the vasa vasorum without intimal tear; this entity is believed to represent aortic dissection.

Adult↗