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Biomedical subjects

H Kikuchi

Publications and source records attributed to H Kikuchi.

At least 829 records · Page 46Linked to original sources
PubMed1984

[Minimal-flow xenon and semiclosed circuit anesthesia for computed tomographic measurement of local cerebral blood flow (LCBF)].

For the purpose of decreasing the volume of expensive xenon, anesthesia with minimal-flow xenon and semiclosed circuit were induced for computed tomographic LCBF measurement. Eighteen patients with ischemic cerebral disease were studied. Anesthesia was induced with minimum dose of thiopental, diazepam and fentanyl. Muscle relaxation was obtained by means of pancuronium bromide. Patients were intubated and ventilated mechanically with flows of 6 l/min. O2 for 20 to 30 minutes to eliminate nitrogen from the system. O2 concentrations in semiclosed circuit were monitored throughout the procedures using galvanic battery. Endtidal CO2 tension was also measured for maintaining normocarbia. Blood gas analyses were carried out before xenon inhalation, during xenon inhalation and immediately before stopping inhalation of xenon-oxygen mixture. Xenon inhalation programs were subdivided into three groups, each of them consisted of 6 patients. The formula for calculating fresh gas flow for low flow semiclosed circuit was introduced according to Shimoji's which was based on the original formula of Foldes. O2 concentration in circuit was predicted to be 25%. Mean xenon uptake for initial 20 minutes was predicted to be 125 ml/min. or 360 ml/min. (Formula: see text) (CRO2: O2% in semiclosed circuit. FO2: fresh O2 flow ml/min. FXe: fresh xenon flow ml/min. VO2: oxygen consumption ml/min. VXe: mean xenon uptake ml/min.) The first group started xenon inhalation during pure xenon inflow into semiclosed circuit for two minutes and followed by about 68% xenon in O2 inhalation for 23 minutes. FXe and VXe were fixed at 700 ml/min and 360 ml/min respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

[Study for lateralization of hemispheric cerebral blood flow by argon method with catheterization into the bilateral internal jugular bulbs].

Only 24 patients with chronic ischemic cerebrovascular lesions, which had been lateralized to either hemisphere of the cerebrum, were analyzed by argon desaturation method measuring bilateral hemispheric blood flows. Their ages varied from 10 to 72 years with a mean of 49 years. Fifteen patients (62.5%) had localized ischemic lesions in the left cerebral hemispheres and remaining 9 patients (37.5%) had in the right hemispheres. The clinical symptom of each patient was lateralized due to localized ischemic focus. Bilateral transfemoral catheterization of the internal jugular bulbs was successfully performed. Each hemispheric blood flow was calculated by argon desaturation method using mass spectrometry based on Fick's principle. Half of the patients, 12 cases revealed lateralization over 20% significant differences of its values. 8 patients (66.7%) were reduced significantly in the left hemispheres and 4 patients were contralaterally. Finally 9 patients revealed that CBF values at the affected side was significantly reduced with no anatomical differences among sinus systems. It is probably that CBF value at the affected side reflects its ischemic lesion more than that at the non-affected side. Several authors reported no predominant lateralization between bilateral sinus draining systems. Based on possibility of "laminar flow" in the confluence, CBF value at the affected side is more important. So further investigations are needed for the future.

Adolescent↗
PubMed1984

[Study on the vertebro-basilar system in "moyamoya" disease].

Posterior circulation in 82 children of "moyamoya" disease are studied. Two aspects of "moyamoya" disease, (ie; occlusive lesion of cerebral vessels and the development of abnormal vascular network as collateral channel,) are also detected in the vertebrobasilar system. Among 82 cases, 49 cases showed the occlusion of posterior cerebral artery at their quadrigeminal segment. Twenty-three showed the more proximal occlusive lesions. Vertebral artery occlusion were found in 3 cases. As the occlusive lesion progresses, abnormal vascular network at the posterior portion of skull base developed. This network consists mainly of thalamogeniculate artery, posterior choroidal artery, and also of other thalamoperforators. Visual field defect as an ischemic symptom of occipital lobe was detected in 9 cases (11%). Superficial temporal artery-middle cerebral artery anastomosis and encephalo-myo-synangiosis (temporal muscle graft), which were not considered to be so effective to the ischemia of the posterior circulation, were shown to exert indirect redistribution effect upon the vertebrobasilar system. However, this effect is such an indirect one that these surgical treatments cannot prevent the occurrence of ischemic stroke in the vertebrobasilar system. For this purpose, omentum transplantation to the occipital lobe may be needed as a method of direct revascularization.

Adolescent↗
PubMed1983

Hypertriacylglycerolemia and adipose tissue lipoprotein lipase activity in the Nagase analbuminemic rat.

In Nagase analbuminemic rats, serum triacylglycerol levels were significantly elevated. This abnormality was accompanied by decreased adipose tissue fat stores, and both were more marked in female than in male rats. Parametrial adipose tissue lipoprotein lipase activity was determined in normally fed female rats. When expressed per mg protein, the activity in analbuminemic rats was only 35% of that in control rats. The activity in analbuminemic rats, however, could be increased as in control rats by refeeding starved animals with a fat-free and carbohydrate-rich diet, and the peak values recorded were the same with the two groups. Treatment of animals with streptozotocin lowered adipose tissue lipoprotein lipase activity in both groups to similar levels. These results suggest that hypertriacylglycerolemia associated with analbuminemia may be caused, at least in part, by altered hormonal control of adipose tissue lipoprotein lipase activity.

Adipose Tissue↗
PubMed1983

The effects of drowning media on the lung water content. An experimental study on rats.

Three kinds of drowning media, i.e., fresh water, isotonic saline, and hypertonic saline were used. After a rat was placed in a desiccator, measuring 17 cm in height and 14 cm in diameter, the vessel was filled with fluid. The average survival time of about 2.5 min did not differ significantly among the three groups. The hypertonic saline group showed the highest values in both the water content of the lung and the lung/body weight ratio; however, this group did not differ significantly from the isotonic saline group in either of the parameters. The difference between the isotonic saline group and the fresh water group was significant. There was a significant positive correlation between the two parameters. However, the lung/body weight ratio was more sensitive to the nature of the drowning media. The frequency, with which froth appeared at the nostrils of the animals that were recovered from the fluid differed significantly among the three groups. The froth appeared almost exclusively in the rats drowned in saline solution. The appearance rate seemed to depend on the salinity of the fluid. There was no significant difference in lactate concentrations among the three groups. The electrolyte (Na and Cl) concentrations in the blood of the right side of the heart reflected the composition of the drowning media.

Animals↗
PubMed1983

An acute fatal occupational cadmium poisoning by inhalation.

A 43-year-old male smelter was admitted to a hospital on account of severe dyspnea about 2 days after exposure to brownish-yellow smoke produced by melting of "copper" scrap. On admission pronounced hypoxemia was revealed, and an oxygen-enriched gas was administered after intubation. Although inspired oxygen concentration was gradually increased, hypoxemia progressed and he died on day 11 in hospital. The principal autopsy finding was chiefly confined to the lungs. Both lungs were heavy (the left weighing 1,470 g; the right 1,710 g) and firm to the touch. Histologically, no normal alveoli were found throughout the entire lung. Some alveolar spaces were occupied by pneumocytes, others by organized exudate with fibrosis. Interstitial fibrosis was present. Patchy areas of inflammatory cell infiltrations as well as intra-alveolar hemorrhages were observed. On the basis of the above findings a diagnosis of diffuse alveolar damage was made. Based on the available evidence (presence of cadmium in the "copper" scrap, feature of the smoke, clinical signs with latent time, and high cadmium concentration of the lung), the diffuse alveolar damage was considered to have been caused by inhaled cadmium. The pulmonary change of the present case was more advanced in pathologic stage in comparison with those reported in the literature.

Adult↗
PubMed1983

Maltotriose and maltotetraose excreted in urine following intravenous administration of maltose to human volunteers.

To determine the extent of maltose excreted into the urine, sugar substances present in the urine following intravenous infusion of maltose were analyzed. Maltose, glucose, maltotriose and maltotetraose in the urine were detected by gas chromatography and identified by mass spectrometric analysis. The total amounts of sugar substances excreted after 10 per cent maltose solution given at three different infusion rates were calculated. The excreted amounts of maltotriose and maltotetraose increased in a dose and time dependent manner. As these compounds were not detected in the plasma either during or after the administration of maltose, the kidney probably plays a role in the biosynthesis of maltotriose and maltotetraose. Studies on the organ homogenates of the rabbit showed that the enzyme activity for the biosynthesis of maltotriose from maltose was mainly in the kidney. The glucose excreted into the urine probably originates from maltose catalyzed to glucose, mainly by the action of kidney maltase. As the rate of excretion of sugar substances increased in a dose dependent manner, adequate infusion rates of maltose should be less than 0.5 g/kg/hour.

Adult↗
PubMed1983

Spinal cord arteriovenous malformations associated with spinal aneurysms.

Two patients with spinal cord arteriovenous malformations (AVMs) had coexisting spinal aneurysms on their main feeding arteries. The angiographic disappearance of these coexisting aneurysms after artificial embolization of the spinal cord AVMs suggests that hemodynamic stress is the important factor in the development of spinal aneurysms. The incidence of hemorrhage increases when spinal cord AVM is associated with spinal aneurysm.

Adolescent↗
PubMed1983

Thyroid abnormalities in diabetes mellitus.

We studied the incidence of goiters and that of thyroid antibodies in 278 patients with diabetes mellitus, in whom six subjects with primary hypothyroidism were excluded, and measured their serum TSH concentrations. The incidence of goiters was 31.8%, and was higher in females than in males. The incidence of goiters in diabetics under the age of 40 was higher than that in subjects more than 40 years old, and the incidence of microsome antibodies and thyroglobulin antibodies were found to be 18.5% and 1.8%, respectively, in these two groups. The percentage of microsome antibodies was lower in diabetics between the ages of 40 and 60 than in diabetics under the age of 40 or over the age of 60. The incidence of goiters and microsome antibodies was not related to the treatment of diabetes mellitus. There was a significantly positive correlation between serum TSH concentration and age in diabetics with serum TSH levels less than 5 microU/ml. As a result, although the incidence of goiters in diabetics was found to decrease with age, the incidence of thyroid antibodies and serum TSH levels were found to increase. These findings suggest that it might be possible to observe atrophic autoimmune thyroiditis, sometimes resulting in subclinical hypothyroidism, in aged diabetics.

Adult↗
PubMed1983

Improved dietary treatment with low protein and phosphorus restriction in uremic rats.

The independent effect of low-protein or low-phosphorus diets in chronic renal failure were studied. The following four isocaloric diets, which contained various amounts of protein (24%, 6%) and phosphorus (0.5%, 0.12%) were fed to chronically uremic rats: high protein and no phosphorus restriction (HPrNP), high protein and phosphorus restriction (HPrRP), low protein and no phosphorus restriction (LPrNP), and low protein and phosphorus restriction (LPrRP). Adult male rats were made chronically uremic by electrocoagulation of one kidney and contralateral nephrectomy. Two grades of renal damage were produced, one of which was mild and the other severe. The mean number of days of survival in the severely uremic animals was 7.5 +/- (SEM) 2.5 with the HPrNP diet, 17.6 +/- 2.4 with the HPrRP diet, 20.3 +/- 2.3 with the LPrNP diet, and over 41.8 +/- 2.5 with the LPrRP diet during a 50-day period of observation. The BUN, serum creatinine (SCr), calcium (SCa), phosphorus (SP), urea and creatinine clearances (Curea, CCr), and plasma PTH levels before and 3 weeks after the diets were compared in the surviving rats with mild and severe uremia. There were marked reductions in the BUN and SP concentrations with the low-protein diets, whereas the SCa increased with all diets. Curea remained practically unchanged with the low-protein diets, whereas CCr decreased with all diets. Plasma PTH levels varied with each diet, but those rats with elevated PTH levels before dietary therapy experienced a fall in plasma PTH after the low-phosphorus diets were administered, with or without protein restriction.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗