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Biomedical subjects

T Kamada

Publications and source records attributed to T Kamada.

At least 775 records · Page 43Linked to original sources
PubMed1983

Gastric mucosal blood distribution and its changes in the healing process of gastric ulcer.

Changes in gastric mucosal blood volume in the healing process of ulcers were investigated by organ reflectance spectrophotometry performed during endoscopy. Spectra were taken from 24 regions in the stomach in 42 patients with gastric ulcers located at the angle of the stomach. Fifty-one patients with no gastric lesions were used as normal controls. In patients with active gastric ulcers, mucosal blood volume decreased significantly in most regions in the stomach. During the healing process, mucosal blood volume returned to the same levels as those of the controls. On the other hand, mucosal blood volume around the gastric ulcer increased significantly as compared with that of surrounding mucosal at the healing stage. The rise in mucosal blood volume of the ulcer margin at the healing stage (H2 stage) was 33% in cases where gastric ulcers healed within 3 mo, and 2% in cases where the gastric ulcer failed to heal after 3 mo of therapy. It was concluded that the mucosal blood volume changes during the healing process of gastric ulcer and that an increased blood supply to the ulcer margin at the healing stage has a strong effect on the healing periods of ulcer. The reduction of mucosal blood volume at the active stage of the ulcer may also be implicated in the pathogenesis of gastric ulcers.

Adult↗
PubMed1982

Responses of cerebellar neurons of the CF-FM bat, Pteronotus parnellii to acoustic stimuli.

Single units (125) which faithfully discharged action potentials to acoustic stimuli (35 ms in duration with 0.5 ms rise and decay times) were recorded in the cerebellar vermis and hemispheres of the CF-FM bat, Pteronotus parnellii. These units had response latencies between 1.5 and 27 ms and minimum thresholds between 2 and 83.5 dB SPL. Best frequencies (BFs) of these units ranged from 30.32 to 79.28 kHz, but more than half (64 units, 51.2%) were between 59.73 and 63.32 kHz. While most tuning curves of these units were either broad or irregular, those curves with BFs tuned at around 61 kHz which is the frequency of the predominant CF component of the bat's echolocation signals were extremely narrow with Q10-dB values as high as 153. Those units (29) with BFs tuned near the 61 kHz also showed off-responses. These data indicate that auditory specialization for processing of species-specific orientation signals also exists in the cerebellum of this bat.

Animals↗
PubMed1982

[Testosterone-estradiol binding globulin and sex steroids during pregnancy and at delivery].

Testosterone-estradiol binding globulin (TeBG), testosterone, estradiol-17 beta, index-T (testosterone not bound to TeBG) and index-E2 were determined during pregnancy, at parturition, in the umbilical artery and vein, and during postpartum periods. TeBG showed a rapid increase during the early pregnancy and then it reached a certain level at the mid pregnancy. At parturition, it decreased to about half of the late pregnancy. In the umbilical artery and vein the level was extremely low. Testosterone gradually increased from the early to the late pregnancy. However, index-T reached its lowest level during the 5th month of pregnancy. In the umbilical artery and vein testosterone exhibited a slightly lower level in comparison with the maternal blood but in contrast to this index-T exhibited five times higher level in the umbilical artery and vein than in the maternal blood. Estradiol-17 beta exhibited a linear increase from the early to the late pregnancy but index-E2 showed a sudden increase during the late pregnancy. The levels in the maternal blood at the parturition and in the umbilical artery and vein were compared: The estradiol-17 beta levels were maternal blood greater than umbilical vein greater than umbilical artery and the index-E2 levels were maternal blood .=. umbilical vein greater than umbilical artery.

Estradiol↗
PubMed1982

Gastric mucosal hemodynamics after thermal or head injury. A clinical application of reflectance spectrophotometry.

In order to elucidate the role of mucosal blood flow in stress ulceration in critically ill patients with thermal or head injury, we applied reflectance spectrophotometry to the human gastric mucosa. During gastrofiberscopy, the spectra of the corpus and antral gastric mucosa were taken using a flexible coaxial optic bundle and a computer-equipped spectrophotometer. The subjects were 27 patients with thermal or head injury, and they were compared with 8 young healthy volunteers and 9 age-matched patients who had GI symptoms but showed no gastric lesion endoscopically. In 8 patients whose gastric mucosal blood volume at the time of admission decreased to about 27% of the level of young healthy volunteers or 36% of that of age-matched controls, the acute gastric mucosal lesions appeared in the corpus mucosa mostly within a few days after the measurement of mucosal blood volume. In contrast, in cases with thermal or head injury and without acute gastric mucosal lesions, the mucosal blood volume did not decrease significantly as compared with that of the young healthy volunteers and age-matched controls. In conclusion, analysis of mucosal has revealed that ischemia in the gastric mucosa is the main cause of the acute gastric mucosal lesions in patients with thermal or head injury. Further, this study represented noninvasive methodology for the measurement of the gastric mucosal blood volume in patients with gastric diseases.

Adult↗
PubMed1981

Hemoperfusion, rate of oxygen consumption and redox levels of mitochondrial cytochrome c (+c1) in liver in situ of anesthetized rat measured by reflectance spectrophotometry.

Utilizing reflectance spectrophotometry, hemoperfusion, rate of oxygen consumption and redox level of mitochondrial cytochrome c (+c1) in livers in situ of anesthetized rats were measured. The transition to the anoxic state was induced by raising the pressure on the liver surface to more than the hepatic blood pressure by pressing with the tip of the optical guide of the reflectance spectrophotometer. During this transition, the average oxygen saturation of hemoglobin in the liver in situ decreased linearly with time until it became 10--20% of the total. This was followed by reduction of mitochondrial cytochrome c (+c1), which reached completion in 10--20 s. The measured O2 consumption rate remained constant until the percentage of oxyhemoglobin in situ decreased to a critical level. There was then a decrease in the rate of O2 consumption which was accompanied by a progressive reduction of cytochrome c (+c1). It was shown that amounts of hemoglobin and mitochondrial respiratory chain cytochromes in the liver in situ could be measured non-invasively and could provide important signals for vital cellular functions. The changes in hemoperfusion and rate of O2 consumption of the liver in situ following ethanol ingestion were also shown in rats, and are briefly discussed with respect to possible application of this method to study the pathophysiology of tissues.

Animals↗
PubMed1981

Heterogeneous intrahepatic distribution of blood flow in humans.

Color-functional imaging of intrahepatic blood flow was developed using the 133Xe clearance method and a gamma camera with a computer system. During the 2 min after intrasplenic injection of 133Xe in saline solution, 24 sequential gamma images were obtained. After setting the hepatic region, 133Xe clearance curves were extracted from the serial images every 6 X 6 mm element and regional blood flow for each element was calculated. The calculated regional hepatic blood flow values were displayed as a color images in eight color steps. Eleven patients with and without liver diseases were studied. In all the patients studied, heterogeneous intrahepatic distribution of blood flow was clearly demonstrated by the functional image of regional hepatic blood flow. Although a consistent pattern of intrahepatic distribution of blood flow was not obtained, greater-flow regions were frequently observed in the right lobe. Repeat studies in two patients demonstrated that the intrahepatic distribution of blood flow varied. The 10-15 s scintiphotosplenoportograms also showed the existence of restricted or preferential intrahepatic distribution of splenic flow. These results strongly suggest that intrahepatic distribution of blood flow in the human liver is heterogeneous and variable.

Hepatitis↗
PubMed1981

Glucose tolerance and respiratory activities of human liver biopsies: their interdependence.

To determine a possible relation of hepatic oxidative activity to glucose metabolism, the rates of oxygen consumption of liver slices from patients with chronic liver diseases were polarographically measured. The livers from patients with chronic (persistent and aggressive) hepatitis and with normal glucose tolerance showed almost the same respiratory activity as those from patients with normal livers and normal glucose tolerance, whereas the livers from patients with chronic hepatitis and with diabetic glucose tolerance (ie, diabetes mellitus secondary to chronic hepatitis) showed only a half the normal level. The decreased rate of respiration was also observed in liver slices from cirrhotics with glucose intolerance. The decrease in respiration was found in patients with normal or hyperinsulinemia as well as hypoinsulinemia responding to oral glucose load. No liver tests so far examined, except the oral glucose tolerance test, correlated with hepatic respiratory activity. It is concluded that in patients with chronic liver diseases the defect of liver respiration has a close relation to the glucose metabolism and is not necessarily associated with histological change of the liver.

Adult↗
PubMed1981

Lipid peroxidation in alcoholic liver disease in humans.

The lipoperoxide level in liver as well as serum in alcoholic patients was measured by using the thiobarbituric acid method. Heavy drinkers with deposition of fat in liver had a significantly (p less than 0.001) higher level of hepatic lipoperoxide examined in about 7 days after abstinence than did nonalcoholic individuals with histologically normal liver. Of these heavy drinkers, cases with a remarkably high level of liver lipoperoxide showed a high incidence of hepatic cell necrosis. The hepatic lipoperoxide level was correlated with the serum lipoperoxide level in these heavy drinkers (r = 0.750, p less than 0.001). In chronic alcoholics, high levels of serum lipoperoxide were usually observed on admission, and a significant positive correlation was found between the serum lipoperoxide level and serum GOT activity (r = 0.541, p less than 0.01). After a 2-wk abstinence, the levels of serum lipoperoxide decreased, which was associated with improvement of liver function tests. These results suggest a possible involvement of lipid peroxidation in alcohol-induced liver damage in humans.

Adult↗
PubMed1981

Erythrocyte membrane microviscosity in diabetes.

Decreased erythrocyte membrane fluidity was revealed by analyses with fluorescence depolarization using 1,6-diphenyl-1,3,5-hexatriene (DPH) and with electron paramagnetic resonance using spin-labelled stearates (EPR). The decreased membrane fluidity measured by DPH appeared to be related to the increase in membrane or plasam free cholesterol to phospholipid (C/PL) mol ratios. The decreased membrane fluidity observed by EPR appeared to be located, at least in part, in a deeper portion of membrane lipid core and the change may not be derived principally from the effect of cholesterol. Increases of membrane sphingomyelin (+ lysophosphatidylcholine) and decreases of phosphatidylethanolamine were found in erythrocytes of diabetic patients. The contributing factors to the decreased erythrocyte membrane fluidity in diabetic patients were suggested to be not only an increase in membrane C/PL mol ratios but also multifactorial changes involving membrane phospholipid fractions and other complex factors. It is considered that the determinant factors of membrane fluidity are so complex that the decreased membrane fluidity observed with diabetic erythrocytes cannot be closely correlated with any single constituent measured. The decreased membrane fluidity observed in this study appears to be related to poor metabolic control and is often associated with diabetic microangiopathy.

Blood Viscosity↗