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Biomedical subjects

H Kadowaki

Publications and source records attributed to H Kadowaki.

At least 127 records · Page 7Linked to original sources
PubMed1980

Proline oxidase inhibition by free fatty acids of rat pancreas.

Proline oxidase activity was not measurable in pancreas homogenate but was measurable in pancreas slices. Moreover, added pancreas homogenate inhibited proline oxidase activity in rat liver mitochondria and several other tissues. The partially purified inhibitor from pancreas also inhibited the activity of glutamate, glucose 6-phosphate, NADH and succinate dehydrogenases. The inhibition was reversed by the addition of bovine serum albumin. Further studies to identify the inhibitor indicated that it consisted of free fatty acids that were enzymatically released after homogenization of pancreas. The free fatty acids released appeared to be derived primarily from triglycerides.

Animals↗
PubMed1978

An assay for arginase in chicken kidney.

1. The enzyme arginase in chicken kidney is associated with mitochondria and the mitochondrial membranes must be disrupted to obtain maximum activity. 2. When the membranes were disrupted by sonication, approximately 30% higher 2. When the membranes were disrupted by sonication, approximately 30% higher arginase activity was observed than with the nonsonicated samples. 3. The optimum pH for assay of chick kidney arginase was 9.7-9.8. Prior heat treatment with Mn2+ decreased arginase activity. 4. Highest enzyme activity was obtained by using sonicated preparations and measuring initial reaction velocity during the first 1-2 min of incubation.

Animals↗
PubMed1978

Assay of leucine aminotransferase in rat tissues and tumors.

A survey of leucine aminotransferase activities in an extensive variety of rat tissues further defined the unique distribution of this enzyme. Its reaction was measured in cell-free extracts under optimal conditions, and its product assayed both colorimetrically and with 14CO2 formed from it by decarboxylation with H2O2. The two methods agreed, though the second was more precise and dependable. In all the tissues and cell fractions examined, except adult liver, the activities with valine and isoleucine were parallel and similar to that with leucine. In adult liver there was low activity only with leucine, which is referable to a known isozyme (type II). Although the fraction of enzyme activity present in mitochondria has often been neglected, these studies showed that this portion in all tissues is about equal, more or less, to that of the more familiar soluble forms. There was good agreement between the relative concentrations of this enzyme in the commonly measured rat tissue preparations as determined here and in the more recently published studies. The unique occurrence of high levels of this enzyme in heart, kidney, brain and muscle, in that order, was confirmed. The unusual distribution of this enzyme was emphasized by the recognition that equally high or even higher levels also occurred in pancreas, lactating mammary gland and salivary gland. The relative amounts were less in normal, undifferentiated and in neoplastic tissues.

Amino Acids, Branched-Chain↗
PubMed1977

[Isocount scanning in the diagnosis of the brain abscess (author's transl)].

The purpose of this study is to investigate salient diagnostic features of the brain abscess in RI brain scanning. In 27 patients with brain abscess, 37 scannings were performed in the various stages of their clinical courses. The results were positive in all cases. Among 27 cases, ten cases were investigated by means of the ISOCOUNT SCANNING SYSTEM, the technical detail of which was reported previously. It was proved that the isocount scanning method combined with the multilevel analysis was more sensitive diagnostic aid than the conventional RI scintigraphy. Using the newly developed method, it was not difficult to diagnose the brain abscess in its early stage, even in the stage of presuppurative cerebritis. Doughnut sign was seemed to be more frequently visualized by this method. Surgical indication of the brain abscess was discussed from nucleomedical view point, and it was emphasized that so-called doughnut sign in brain scanning would indicate the appropriate stage of the brain abscess to be operated on.

Adolescent↗
PubMed1977

[Isocount scanning in brain tumors-a quantitative investigation of the tracer activity (author's transl)].

In the previous reports, the theoretical background [corrected] and technical details of the Isocount scanning were described. Based on clinical experiences of various brain diseases, the newly developed scanning method was confirmed to be more useful than the conventional scintiscanning. Besides the new scanning method, a new display system was also developed for the sake of more precise analysis of the Isocount scanned data. This display method is called MULTILEVEL ANALYSIS or MULTILEVEL SLICING. In the present investigation, this method was applied to fortysix cases of brain tumors, including forty cases of supratentorial tumors and six cases of infratentorial tumors, positive rates being 95% and 67% respectively. Furthermore, as a measure of the quantitative investigation of the radioactive tracer uptake of the target area, the maximum uptake rate of the target area (RTmax.=Tmax./NTmean), and the deviation index (DI=DT/DNT) were introduced; Tmax., NTmean, DT and DNT are respectively defined as a maximum uptake of the target area, a mean uptake of the non-target area, a deviation rate of the target area and a deviation rate of the non-target area. They can be obtained from analysing the television figures of MULTILEVEL ANALYSIS. By this method, thirty-four cases of supratentorial tumors were studied. In cases of glioma (12 scans), meningioma (9 scans), and metastatic tumor (7 scans), the mean values of RTmax. were 1.26, 1.37, and 1.24 and the mean values of DI were 0.81, 0.68 and 0.60 respectively. In gliomas, the RTmax. and the DI were correlated with the degree of malignancy of the tumors. This quantitative analysis could be considered to be useful to foresee the nature of the brain tumor from the scintiscanning findings.

Adolescent↗
PubMed1977

[A case with bilateral internal carotid and left vertebral artery occlusion (author's transl)].

Since Moniz reported the obstruction of the extracranial internal carotid artery in 1937, there have been many reports of extracranial arterial occlusion. The authors experienced a case of 40-year-old woman who had minor neurological deficit such as attack of black out, disturbance of the bilateral visual acuity, concentric narrowing of the bilateral field and disturbance of the bilateral auditory acuity, in spite of complete obstruction of both internal carotid arteries and the left vertebral artery, and possible obstruction of the right vertebral artery. The angiograms showed well developed collateral circulation. The cause of the obstruction was considered to be angitis following otitis media and meningitis in her childhood. The symptoms were alleviated by drugtherapy.

Adult↗
PubMed1976

Intracellular localization of arginase in chick kidney.

Although chickens are uricotelic and do not have significant urea-ornithine cycle in any tissue, the kidneys contain a high concentration of arginase which apparently functions to regulate degradation of dietary arginine. A series of investigations has been made to determine the intracellular localization of this arginase in chicken kidney. Tissue fractionation using sucrose density gradients and differential centrifugation showed as association of arginase activity with certain marker enzymes and with fractions identified as mitochondria by electron microscopy. This is consistent with the localization of the arginase in the mitochondrial matrix of chicken kidney cells. Such a finding has significance in understanding the regulation of arginine degradation in chickens.

Animals↗
PubMed1976

[A trial of surgical management of brain edema in cerebral infarction--a review with our own experiences in 31 cases (author's transl)].

We have analyzed the clinical course of 31 cases with cerebral infarction for 4 years. Of the 31 patients, 6 cases (19%) showed the brain edema on the cerebral angiograms as manifested by the shift of the midline arteries. The patients were divided into two groups, normotensive (15 cases) and hypertensive cerebral infarction (16 cases). The clinical and angiographic findings in the normotensive groups have been differed significantly from those of the hypertensive groups. The findings of brain edema on the angiograms were prominent in the hypertensive groups, and the clinical course was generally good and fair in the normotensive groups. We have reviewed the literatures about brain edema associated with cerebral infarction and have discussed on the mechanisms. From the study of our cases, it was concluded that systemic hypertension could be a facilitatory factor in the occurrence of brain edema in cerebral infarction. Furthermore, the management of massive cerebral infarction should be reduction of increased intracranial pressure and prevention of cerebral herniation. So, it will be necessary to perform a surgical treatment such as internal decompression; removal of the infarcted, necrotized area and excision of herniated tissue, and external decompression; removal of boneflap.

Acute Disease↗
PubMed1975

[Diagnostic value of isocount scanning in cerebrovascular diseases (author's transl)].

In the previous report the theoretical background and technical details of the isocount scanning were described. Based on clinical experiences of various brain diseases, the newly developed scanning method was confirmed to be more useful than the conventional scintiscanning. Besides the new scanning method, a new display system was also developed for the sake of more precise analysis of the isocount scanned data. This display method is called multilevel analysis or multilevel slicing of the scanned data. In the present investigation, this method was applied to thirty-two cases of cerebrovascular diseases, including seven cases of cerebral arterio-venous malformation, four cases of hypertensive intracerebral hemorrhage and twenty-one cases of cerebral infarction, positive rates being 86%, 100% and 90% respectively. In case of arterio-venous malformation, minimum size detected by the isocount method was 2 cm in diameter. To twenty one cases of the cerebral infarction, total thirty two scanning examinations were performed, including postictal follow up studies. It is often said that it is two or three weeks after the ictus when the infarcted cerebral lesion is most clearly detectable by the scintigraphic procedures, presumably due to focal neovascularizations which may occur in the lesion most prominently at this postictal stage. Contradicted to the current concept, our experiences show that abnormal dot accumulations are recognized in the scintigrams even at the earlier stage, thus among five cases of cerebral infarction scanned within a week after the ictus positive figures were obtained in four cases, two of which were examined within two days after the ictus. Focal breakdown of blood brain barrier at the acute stage is considered to be responsible for the early positivity in cerebral infarctions. In eight cases among twenty one cerebral infarctions angiographies failed to demonstrate the vessel occluded. The isocount scanning method, however, succeeded in getting positive results in seven of the eight cases. It will be emphasized that the isocount scanning is a preferable diagnostic procedure in the cerebrovascular diseases, especially when the angiography is hesitated to be performed because of the patient severely affected.

Adolescent↗
PubMed1975

[Isocount scanning of the brain (author's transl)].

It is well known that the gamma ray emitted by a radionuclide is a Poisson process, so its statistic nature should be taken in consideration when the scintiscanning is performed. But very few attempts have been done from this point of view. After examining in detail the imaging pulse charactristics, the authors introduced a mean for evaluating the fidelity of the collected data, and based on this criterion, pointed out some problems in the conventional scanning method and finally described a statistical way of improving the scintigram. In the present investigation, as a measure of the stochastic fidelity of the scanned data the relative deviation eplision(n) = sigma(n)/E(n) is introduced; sigma is the standard deviation and E(n) is the expectation value of the counting rate. In the conventional scanning in which the detector moves with a costant speed, the relative deviation varies from area to area according to the concentration of the radioisotope in the brain. In the so-called cold area of the brain scintigram, the relative deviation fluctuates remarkably because of a rather low density of radioisotope in this area.

Adult↗