Biomedical subjects
Publications and source records attributed to K Fujii.
Two cases of extremely rare aneurysms of peripheral portions of the AICA are reported with a review of the pertinent literature. According to reported surgical findings, nearly all of the aneurysms originated from arterial loops near the internal acoustic meatus. These aneurysms can therefore, cause the cerebellopontine angle syndrome, with or without subarachnoid hemorrhage.
Assay methods which allow measurements of the level of individual P-450's in a homogenate of steroidogenic tissues have been developed. The assay is based simply on the determination of the specific products of steroid monooxygenase reactions under conditions in which sufficient amounts of the purified electron-donating components as well as lipids and detergents are supplemented so that the membrane-associated P-450 is able to exhibit its maximum activity. Under these conditions, an at least 10-fold increase in the NADPH-dependent monooxygenase activity of P-450 occurred as compared to that measured in the unenriched system. In addition, the present assay used ascorbate as an O2- -scavenger which effectively prevented possible inhibition caused by initiation of O2- -formation. Under the present assay conditions, nearly quantitative recovery of activities was accomplished of each purified P-450 that had been added to the homogenates as an internal standard. Furthermore, the high sensitivity of this assay allows the measurement of P-450 in small specimens (at least 100 mg of tissues), and could be used for measurements in autopsied cases or the glands of small animals.
An experiment was performed on Wistar rats to examine the possible carcinogenic effects of charred fish meat. Each group (of 30 male rats each) was fed one of the following diets: the standard diet mixed with 50% charred fish meat (Group 1), the standard diet mixed with 25% charred fish meat (Group 2), the standard diet alone (Group 3), or the 1-methyl-3-nitro-1-nitrosoguanidine (MNNG) treatment in drinking water (Group 4); this last group served as positive control. The animals were observed for two years. No significant incidences of tumors were recorded. However, there were statistically significant incidences of nonspecific pathological lesions of the glandular stomach, such as erosion, regeneration, and hyperplastic epithelium. Also, an atypical epithelium of the stomach was found incidentally in two animals (Groups 1 and 2); this might suggest a premalignant condition.
3-Amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) or 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), which is a potent mutagen from pyrolysates of tryptophan, was given subcutaneously to neonatal ICR mice, and all animals were observed for 1 year. Tumors of the livers and lymphoreticular tissue were induced. In the mice given Trp-P-1, the incidences of these tumors were as follows: liver tumors in 45% of the males; malignant lymphoma in 13% of the males and in 24% of the females. In the mice given Trp-P-2, the incidences of liver tumors in the males were dose-dependent (12.5 mg/kg, 12%; 25 mg/kg, 18%), while those of malignant lymphoma varied within a range from 5 to 19%. Statistical analysis revealed that the incidences of the liver tumor in the mice given Trp-P-1 or Trp-P-2 and those of lymphoma in the mice given Trp-P-1 were significantly higher than those of the controls. In the control mice, the incidences of tumors were as follows: malignant lymphoma in 5% of the females; lung tumor in 14% of both sexes.
We studied the regional differences both of reactivity to various stimulants and of neurogenic responses elicited by transmural stimulation in the longitudinal and circular muscles of the truncal portal vein, mesenteric vein, splenic vein and gastric vein of the dog portal tree. Strong spontaneous activity appeared in the longitudinal muscle of the truncal portal vein (96% of preparations tested). Weak spontaneous activity sometimes appeared in the circular muscle of the truncal portal vein (41%) and rarely in the longitudinal muscle of the mesenteric vein (12%). It did not appear in other segments. The splenic vein and the gastric vein showed similar patterns in the relationship between resting tension and response to noradrenaline; that is, the responsiveness of either longitudinal or circular muscle of these two veins increased and then decreased almost parallel as resting tension increased and reached a maximum under the same resting tension. The longitudinal muscle of both the truncal portal vein and the mesenteric vein was more responsive to noradrenaline, acetylcholine, histamine and KCl than the circular muscle; for example 2.02 and 1.44 times more responsive to noradrenaline, respectively. On the other hand, the longitudinal muscle of the splenic vein and the gastric vein responded less well than the circular muscle; for example 0.36 and 0.16 times as responsive to noradrenaline, respectively. Acetylcholine and histamine caused marked contractions which were comparable to those elicited by noradrenaline in the longitudinal muscle of the truncal portal vein. Acetylcholine also elicited similar contractions in the longitudinal muscle of the mesenteric vein but the responses induced in preparations of other segments were small. 6 The longitudinal muscle of the truncal portal vein responded well even to low-frequency stimulation of 2 Hz, while the circular muscles of the truncal portal and splenic veins gave marked responses only to high-frequency stimulation of 10 or 20 Hz or more. These contractile responses were attenuated by phentolamine (10-6 M) or atropine (10-6 M). The longitudinal muscle of the splenic vein showed no significant response to stimuli of any frequency. 7 It seems that the portal tree receives not only adrenergic but also cholinergic innervation. In addition, the longitudinal muscle of the truncal portal vein may receive non-adrenergic, noncholinergic innervation as well. 8 The longitudinal muscle of the portal vein may be crucial to venous return in assisting movement of the blood it contains. If this is the case in man, then the regional differences in the portal tree demonstrated in this study may explain why varicose changes during portal hypertension occur preferentially in the oesophagogastric region and rarely in other regions, as blood stasis may occur more readily in the regions of the gastric and splenic veins where the longitudinal muscle is not very active.
Platelet count, aggregability and volume in the postoperative course of 20 patients were examined. Platelet count was decreased on the 1st postoperative d, and increased on the 7th and 14th d compared with the preoperative value. The maximal aggregation rate of platelets induced by ADP was decreased on the 3rd postoperative d, and then recovered to the preoperative level. In contrast, platelet volume was only slightly increased on the 3rd postoperative d. In this study, there was no correlation between platelet aggregability and platelet volume in PRP. We have proposed one parameter, 'platelet concentration ratio' (platelet concentration in PRP/platelet concentration in whole blood). In the postoperative course, this concentration ratio changed depending on platelet volume, and possibly on other conditions of blood such as hematocrit, viscosity and specific gravity. The concentration ratio influenced the subpopulations of platelets in PRP. Platelet aggregation tests may be performed using PRP in which platelet subpopulations differ from those in whole blood, especially in the postoperative state.
Cerebrospinal fluid (CSF) lactate and pyruvate concentrations were determined in 16 patients with hepatic encephalopathy before and/or after treatment. CSF lactate was significantly increased to 1.92 +/- 0.11 mmol/l in hepatic encephalopathy before the treatment in comparison to 1.40 +/- 0.05 mmol/l in control subjects. In 9 of 11 patients with moderate or stage 2 encephalopathy, CSF lactate levels were below 2 mmol/l. In contrast, in 4 of 5 patients with stage 3-4 encephalopathy, CSF lactate levels were higher than 2 mmol/l. CSF lactate was decreased with the recovery of neurological symptoms by the treatment. These findings indicate that CSF lactate levels reflect the severity of metabolic impairment of the brain. Hypocapnia was frequently observed in these encephalopathic patients, and arterial PCO2 correlated inversely with CSF lactate and linearly with CSF HCO3-, suggesting that CSF lactic acidosis contributes to hyperventilation in hepatic encephalopathy. It is concluded from present results that metabolic disorder of neuronal cells might be one of the important factors for the development of hepatic encephalopathy.
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Irradiation prior to radical surgical removal has been performed 51 times in 48 cases of brain tumor over the last 7 years. Through this procedure, all cases have attained good results in both clinical and CT evaluations. In the course of radiotherapy, various doses of corticosteroids and/or ventricular drainage were applied to prevent dangerous brain swelling and hydrocephalus. Total radiation doses were 40-50 Gy in primary cases and 30-40 Gy in recurrent cases. Through this preoperative radiotherapy, tumors showed reduction of their feeding vessels (78.9%) on angiography and/or became necrotized with cyst formation. This facilitated case of surgery and permitted radical resection of these tumors (41%). Especially, in cases of germ cell tumors of mixed type and medulloblastomas, this procedure permitted radical resection in 75% and 100% of cases, respectively. Among glioblastomas and grade 3 astrocytomas, 21.7% were radically resected and the patients involved showed a good relative survival rate. This method may actually facilitate radical cure of malignant brain tumors soon.
Streptozotocin-induced diabetic female rats and age-matched control rats were fed a regular chow with or without the addition of 1% cholesterol in the diet. The release of 6-keto-PGF1 alpha, a prostacyclin metabolite, from the mesenteric vascular bed was significantly increased in diabetic rats. The production of PGI2 in diabetic rats was significantly reduced whereas that in the control was not affected by cholesterol feeding. The examination of the fatty acid composition of phospholipids from the mesenteric vascular bed indicated that proportions of stearic (18:0), linoleic (18:2n-6) and dihomo-gamma-linolenic (20:3n-6) acids were higher whereas those of oleic (18:1n-9) was lower in diabetic rats than those in the controls. Cholesterol feeding had no significant effect on the levels of arachidonic acid (20:4n-6) in the controls but it significantly decreased those in diabetic rats. It is suggested that cholesterol feeding lowers the release of PGI2 from the mesenteric vascular bed possibly because of a reduced level of arachidonic acid, the major precursor for prostaglandin synthesis. This could be due to an impairment of delta-5 desaturase.
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In the noninvasive evaluation of aortic regurgitation by Doppler echocardiography, flow mapping of the aortic regurgitant jet using the long-axis approach is of limited value in cases of combined mitral stenotic lesions. This is because the transmitral flow yields flow disturbances in the left ventricle, making it difficult to identify the extent of the aortic regurgitant jet. To overcome these limitations, the severity of aortic regurgitation was evaluated using the cross-sectional area of the aortic regurgitant jet at the level of the aortic valve as visualized by color flow imaging technique. The study population consisted of 16 patients with aortic regurgitation (10 with pure aortic regurgitation, five with superimposed mitral stenosis, and one with mitral valve replacement). Three normal subjects served as controls. The cross-section of the aortic regurgitant jet was visualized as a mosaic of yellow and blue in all patients with aortic regurgitation, but not in any of the controls. Planimetric measurements of the cross-sectional area of the regurgitant jet (J) and the aortic annulus area (Ao) were performed, and the Doppler parameter, J/Ao, was calculated. As a reference, the aortic regurgitant fraction (RF) was calculated from Doppler measurements of systolic aortic and pulmonary flows (AF and PF); RF (%) = (AF - RF)/AF x 100. The Doppler parameter, J/Ao, correlated well with the Doppler measurement of RF (r = 0.82, p less than 0.005), irrespective of the presence of associated mitral lesions. Thus, the cross-sectional area of the aortic regurgitant jet determined by color flow imaging technique would be a useful estimate of the severity of aortic regurgitation, even in the presence of associated mitral stenotic changes.
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