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Biomedical subjects

K Shimamoto

Publications and source records attributed to K Shimamoto.

At least 379 records · Page 21Linked to original sources
PubMed1984

Measurement of the rat urinary plasminogen activator (esterase A) by direct radioimmunoassay in urine and tissue.

Rat urinary esterase A, a plasminogen activator with kininogenase activity, was recently purified and characterized (J. Chao (1983) J. Biol. Chem. 258, 4434-4439). A sensitive radioimmunoassay for esterase A has been developed. This assay uses a rabbit antiserum in a final dilution of 1:160 000 and the purified enzyme was labelled with 125I using a lactoperoxidase method. It detects 80 pg of immunoreactive material per tube. This antiserum has some cross-reactivity with rat urinary kallikrein (approximately 5%) but a previously characterized tissue kallikrein antiserum has negligible cross-reactivity with the urinary esterase A in the assays. Therefore, kallikrein levels are measured simultaneously in all samples to obtain accurate levels of immunoreactive esterase A. Dilutions of urine or tissue homogenates showed complete parallelism with esterase A standard curves. No cross-reactivity with dog, human or monkey urine was seen. The recovery of esterase A from rat urine was 99.7 +/- 3.5%. Intra- and between-assay errors were 6.5 and 11.2%, respectively. Immunoreactive esterase A was measured and compared with kallikrein levels in rat urine, kidney, pancreas, submandibular gland, descending colon and ileum. The urinary esterase A excretion rate was reduced significantly in rats on a high sodium, compared with a low sodium diet, but not significantly increased above control by the latter. Nonetheless, a significant correlation between urinary kallikrein and esterase A excretion rate was present. This radioimmunoassay can now be used to measure esterase A levels in urine and tissue as questions have arisen about its regulation and functional significance.

Animals↗
PubMed1984

Electrocardiographic abnormalities in cerebrovascular accidents.

In order to assess the relationship of electrocardiographic (ECG) changes in acute cerebrovascular accidents (CVA) to the locations of the cerebral lesions, ECG records and brain computerized tomographic (CT) scans which were taken within 48 hours of CVA onset were examined in 39 patients without heart disease and/or treatment with cardiovascular drugs. The ECG was normal in 25% (3/12) of basal ganglial CVA, 22% (2/9) of frontal CVA and 36% (4/11) of temporo-parietal CVA. Nonspecific ST-T changes occurred in basal ganglial CVA (25%), frontal CVA (22%), temporo-parietal CVA (18%) and in the other categories of CVA locations. Corrected QT interval (QTc) elongation was observed not only in frontal (22%), but also in basal ganglial CVA (25%), temporo-parietal CVA (36%) and cerebellar CVA (50%). There were no ECG changes specific to a particular CVA location. These findings suggest that widely distributed neurons and pathways within the central nervous system may influence ECG.

Adult↗
PubMed1984

An ectopic, ACTH producing, oncocytic carcinoid tumor of the thymus: report of a case.

A 39-year-old man with an ACTH producing oncocytic carcinoid of the thymus is reported here. His symptoms were pigmentation, facial and pretibial edema, and high blood pressure. Endocrinological examination revealed the ectopic ACTH syndrome and, especially, high content in the intrathoracic venous blood. On histological examination, the tumor was found to be composed of uniform eosinophilic cells, with no argentaffin granules being demonstrated. Ultrastructural findings revealed a large number of mitochondria and numerous distinct electron-dense neurosecretory granules in the cytoplasm. Abnormally high levels of ACTH, beta-endorphin and gamma-MSH were also found in this tumor tissue. By total extirpation of the tumor, clinical symptoms and laboratory data were entirely normalized.

ACTH Syndrome, Ectopic↗
PubMed1984

Study on the renal kallikrein-kinin system in normal and low renin subgroups of essential hypertension.

In order to investigate the role of the renal kallikrein-kinin (K-K) system in normal (NRH) and low renin (LRH) subgroups of essential hypertension (EHT), daily excretions of urinary kallikrein (KAL) quantity and activity, kinin (KIN), total and pre-KAL, and kininase I and II were measured in 21 normotensives (NT), 29 patients with NRH and 16 patients with LRH. The daily excretions of both KAL quantity and activity, total and pre-KAL, and KIN were significantly lower in NRH and LRH than in NT. That of kininase I was significantly higher in NRH and LRH than in NT, but that of kininase II was not. In comparing NRH and LRH, the urinary excretions of KAL activity and KIN were lower in LRH than in NRH, and that of kininase I was higher in LRH than in NRH. The KAL/total KAL ratio did not show any significant difference among NT, NRH and LRH. These findings suggest that the suppression of the renal K-K system in EHT seems to be due to both the decrease of KAL through the pre-KAL synthesis in the kidney and an increase of kininase I activity, but not to the inhibition of conversion from pre-KAL to active KAL and the more obvious suppression of this system in LRH than in NRH may be partly explained by KAL inhibitors and/or increased kininase I activity.

Adult↗
PubMed1984

[Early stomach carcinoma--current development in Japan].

At first an analysis is presented of 656 patients with early carcinoma of the stomach, which had been diagnosed during the last 10 years. Most frequently found were depressed or excavated lesions (type IIc, III). 53% of all lesions were located in the mucosa only, in 8.3% lymph nodes were infiltrated, - mostly in such cases, where the primary tumor was located in the antrum, where submucosal layers where involved, or where poor differentiated adenocarcinoma or signet-ring cell carcinoma were present. Diagnostic criteria of minute early gastric carcinoma are discussed. In a second part diagnostic importance of endoscopic sonography is described, especially its importance in regard to estimating depth of infiltration of the tumor. New possibilities of using laser to destroy very small tumors and to treat in a palliative manner malignant stenosis are discussed as well.

Adenocarcinoma↗
PubMed1984

Immunoreactive tissue kallikrein in human serum.

Human urinary kallikrein and an antiserum to it raised in the rabbit were used to detect and quantitate immunoreactive tissue kallikrein in human serum. Both 125I-labeled kallikrein and the unlabeled purified enzyme appear complexed to higher molecular weight entities in serum, but specific binding between radiolabeled enzyme and antiserum was unaffected by the presence of serum or plasma. Parallelism to standard displacement curves was always seen with radioimmunoassay of normal sera as well as with human mixed saliva or pancreatic extracts. Assay sensitivity is 160 pg/ml of serum, or 16 pg per tube. Purified plasma kallikrein or prekallikrein in concentrations up to 10 micrograms/ml showed no displacement. Acetone-kaolin activation of plasma produced the expected 30-fold increase in Tos-Arg-OMe esterase activity but no change in immunoreactive tissue kallikrein levels. Serum concentrations were 3.8 +/- 0.7 (mean +/- SE) ng/ml in 21 normal volunteers, and were similar in patients with Fletcher trait or Hageman factor deficiency. Significantly increased serum concentrations were seen with long-term low dietary sodium intake or acute forms of pancreatitis. Although the relation of this immunoreactive material to any active tissue kallikrein within the circulation remains to be determined, our studies provide a new parameter for the assessment of a system repeatedly suggested to have some role in regulation of vascular resistance.

Adult↗
PubMed1983

Expression of zein in long term endosperm cultures of maize.

Continuous cultures, established 10 days after pollination from endosperms of inbred A636 Zea mays (L.) were extracted 21 months later with aqueous ethanol. The solubilized proteins were analyzed by poly-acrylamide-sodium dodecyl sulfate gel electrophoresis. Two protein bands co-migrated with zein, the major storage protein of maize. Immunoblotting of the gel followed by incubation of the immobilized proteins with anti-zein IgG provided evidence that the polypeptides were in fact zein. Electron microscopic studies showed that the cultures contained cells with protein bodies as found in developing endosperms. The protein bodies could be isolated from the cultures and were shown to contain zein. We conclude that the long term cultures described here synthesize zein and deposit it in the form of protein bodies of the type found in developing endosperms. Thus, certain endosperm characteristics and the production of tissue-specific proteins are retained in prolonged culture.

Journal Article↗
PubMed1983

The role of the renal kallikrein-kinin system in sodium metabolism in normal and low renin essential hypertension.

In order to investigate the pathophysiological role of the renal kallikrein-kinin system in renin subgroups of essential hypertension, the quantity and activity of urinary kallikrein, urinary kinin excretion, and correlations of kallikrein and kinin excretions with renal sodium handling in the renal tubules were studied in 17 normal subjects, 23 patients with normal renin and 12 patients with low renin essential hypertension. Urine samples were collected by the 2-hour clearance method in the early morning. The quantity and activity of urinary kallikrein, and the urinary excretion of kinin were significantly lower in both low and normal renin patients than in normal subjects. Comparing the normal renin and the low renin group, no significant difference was found in the quantity of urinary kallikrein, while the activity of urinary kallikrein and urinary kinin excretion were significantly lower in low renin patients than in normal renin ones. Fractional excretions of sodium (FENa) and inorganic phosphorus (FEP), which reflect renal tubular and proximal tubular sodium reabsorption, respectively, were significantly lower in the low renin patients than in the normal renin ones. A significantly positive correlation was observed between the urinary kallikrein activity or urinary kinin excretion and FENa or FEP in both normal subjects and normal renin patients, but not in low renin patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1983

Plasma antidiuretic hormone levels in patients with normal and low renin essential hypertension, and secondary hypertension.

In order to investigate the antidiuretic hormone (ADH) in essential hypertension and secondary hypertension, plasma ADH levels were measured in normal subjects, in patients with normal and low essential hypertension, and in other patients with various forms of secondary hypertension. Plasma ADH levels were significantly lower in low renin essential hypertension and higher in malignant hypertension than in normal subjects. The plasma ADH levels tended to be lower in renal hypertension and primary aldosteronism, and higher in renovascular hypertension, but these differences were not statistically significant. From these results, it appeared that ADH might play a role in malignant hypertension, but not in the other hypertensive diseases.

Adolescent↗
PubMed1983

A case of 17 alpha-hydroxylase deficiency with special reference to the renal kallikrein-kinin system.

In a 26-year-old male with 17 alpha-hydroxylase deficiency, endocrinological examinations were performed not only after, but also before the onset of clinical signs and symptoms. In addition, the pathophysiological role of the renal kallikrein-kinin system was investigated in this patient. In spite of the fact that this disease is congenital, in the mechanism of its onset, this patient had a period of endocrinological normality before onset; that is, 9 months before onset, both ACTH and cortisol were within the normal range, although the former would be significantly higher and the latter significantly lower than normal values after the onset. In this case, both urinary kallikrein and kininase excretions abnormally increased and then returned to normal after dexamethasone treatment.

Adrenal Cortex Hormones↗
PubMed1983

Generalized epilepsy in a patient with hypokalemic periodic paralysis and cardiac arrhythmia.

A 17-year-old female who had Hypokalemic periodic paralysis with arrhythmia developed syncopal attacks. Although syncope in this rare disorder has been attributed to ventricular tachycardia or ventricular fibrillation, the clinical manifestation, electroencephalogram, serum electrolytes and blood sugar at the attack, and the results of lumbar puncture indicated that idiopathic generalized epilepsy was the cause of the syncopal attacks in the present case. To our knowledge, this is the first case report of the association of epilepsy with periodic paralysis and arrhythmia in the literature.

Adolescent↗
PubMed1983

The excretion of human urinary kallikrein quantity and activity in normal and low renin subgroups of essential hypertension.

In both low and normal renin essential hypertensive groups, urinary excretion of kallikrein quantity by direct radioimmunoassay and activity by kininogenase assay were significantly lower than those in normal subjects. In comparing between normal and low renin groups, no difference was found in kallikrein quantity, while kallikrein activity tended to be lower in the low renin group than in the normal renin group. A significant positive correlation was observed between kallikrein quantity and activity in the normal subjects, the normal renin group and the low renin group. However, the slope of the regression line in the low renin group was significantly more moderate than that in the normal renin group, and tended to be more moderate than that in normal subjects. The addition of kallikrein inhibitors (aprotinin and gabexate mesilate) resulted in a significant suppression of enzymatic activity but not of enzyme quantity. These findings suggest that suppression of the renal kallikrein system in both groups of essential hypertension was confirmed by the decreased excretion of kallikrein both as enzyme quantity and activity, and that in the mechanism of the suppression of urinary kallikrein activity in the low renin group, the renal kallikrein inhibitors may play some role.

Adult↗
PubMed1982

Human plasma inactive renin: purification and activation by proteases.

A new affinity chromatographic procedure was devised to purify inactive renin by using a selective hydrophobic interaction of inactive renin to octyl-Sepharose. Additional extensive purification was accomplished by immunoaffinity chromatography on antihuman renin immunoglobulin G-Sepharose. A trace amount of active renin was removed by chromatography on pepstatin-Sepharose. Human plasma inactive renin purified by this method was free from protease inhibitors and permitted the investigation of protease-mediated activation without the acid treatment which was used previously to remove inhibitors. Human plasma kallikrein, human plasmin, cathepsin B1, and arginine esteropeptidases associated with mouse epidermis growth factor and nerve growth factor were effective activators. Human urinary kallikrein, hog pancreatic kallikrein, and rat urinary esterase A were inefficient activators of low potency. Thrombin, factor Xa, factor XIIa, and urokinase did not activate inactive renin. The in vitro activation of 56,000-dalton inactive renin by these proteases was not accompanied by a recognizable reduction in molecular weight. Activation required plasma albumin, presumably as a protecting substance. These results suggest that human inactive renin can be activated by a minimum change in its molecular size.

Cathepsin B↗