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Biomedical subjects

K Uchida

Publications and source records attributed to K Uchida.

At least 1,531 records · Page 85Linked to original sources
PubMed1978

Purification and characterization of a myosin-cleaving protease from rat heart myofibrils.

A proteolytic enzyme, which causes the limited degradation of cardiac myosin, was purified from rat heart myofibrils. The purified enzyme (a myosin-cleaving protease) was apparently homogeneous by polyacrylamide gel electrophoresis in the presence and absence of sodium dodecyl sulfate. Autolysis of the purified enzyme was observed at neutral pH without high concentration of CaCl2. The molecular weight was estimated to be 26 000-27 000. The enzyme was active against casein, N-acetyl-L-tyrosine ethyl ester and N-glutaryl-L-phenylalanine-4-nitroanilide (Glu-Phe-NAn), but less active with N-benzoyl-DL-arginine-4-nitroanilide. Optimum pH values for the enzyme were 9.0 for casein and 8.4 for Glu-Phe-NAn. Caseinolytic activity of the enzyme was completely inhibited with phenylmethylsulfonyl fluoride and diisopropylphosphofluoride and partially inhibited with L-1-tosyl-L-phenylalanine chloromethyl ketone (Tos-PheCH2Cl) and soybean trypsin inhibitor. Tos-LysCH2Cl had no effect. Sulfhydryl reagents, metal-chelating agents and metal ions except for Zn2+ had little or no effect on the activity. Degradation of cardiac myosin with the enzyme produced two fragments having molecular weights of 130 000 and 94 000, accompanied by the disappearance of myosin heavy chain and light chain 2. Myosin degradation with the enzyme was more restrictive than with chymotrypsin.

Animals↗
PubMed1978

[Plasma renin activity response to isometric handgrip exercise in normotensive and hypertensive patients (author's transl)].

1) Plasma renin activity (PRA) response to isometric exercise was studied before and after the intravenous administration of 0.2 mg/kg of propranolol in 8 normotensive and 10 normal renin hypertensive patients. 2) Handgrip exercise at the 30% level of maximal voluntary contraction (MVC) for four minutes induced a significant increase in PRA in either normotensive or normal renin hypertensive patients, while the increase in PRA in normal renin hypertensive patients was significantly higher than that in normotensive patients. 3) Pretreatment with the administration of propranolol inhibited an increase in PRA after handgrip exercise in either normotensive or normal renin hypertensive patients. 4) The results suggest that isometric handgrip exercise can induce an augmentation in renin release mainly by stimulation of the sympathetic nervous system in either normotensive or normal renin hypertensive patients. The possible mechanism of the exaggerated response in PRA to handgrip exercise in normal renin hypertensive patients has been discussed.

Adolescent↗
PubMed1978

Ultrastructural localization of calcium around the membrane of the surface connected system in the human platelet.

The localization of calcium in the membrane system of human platelets was determined by ultrahistochemical methods equipped with an electron probe x-ray microanalyzer. After potassium oxalate-glutaraldehyde treatment large amounts of electron opaque precipitates were observed around the membrane of the surface connected system. Electron probe x-ray microanalysis clearly defined that the precipitates were composed of calcium oxalate. The localization of calcium on the membrane of the surface connected system was also confirmed even after treatment of the platelets with potassium antimonate-OsO4. These results support a model which depicts the surface connected membrane system taking part in the store and the transport of calcium.

Blood Platelets↗
PubMed1978

Colon perforation after kidney transplantation.

Between 1962 and 1977 approximately 2% of Denver kidney transplant patients developed colon perforation. The single commonest cause was diverticulitis of the left colon (6/13 cases). In spite of drastic reduction or discontinuation of immunosuppression, only 5/13 patients survived for more than 90 days after operation. Analysis of this experience suggests that the high mortality rate associated with this complication can be reduced by early operation which removes the perforation from the peritoneal cavity (either exteriorization or resection) without primary intestinal reanastomosis. We believe that candidates for kidney transplantation with a history of previously symptomatic diverticulosis coli should have elective colon resection prior to transplantation. Any kidney transplant patient with lower abdominal signs should be investigated and treated aggressively.

Adolescent↗
PubMed1978

Opsoclonus inducing retinal detachment with a macular hole.

A 34-year-old man was admitted to the eye department because of conjugate abnormal eye movements and visual field defect of the right eye. Cerebellitis with opsoclonus and retinal detachment with a macular hole were diagnosed. Corticosteroids, diazepam and antibiotics were given. When the opsoclonus was improved, an operation for the retinal detachment was performed as usual, and the retina was reattached. We consider that the opsoclonus greatly contributed to the occurrence and development of the retinal detachment.

Adult↗
PubMed1978

[Relationship between some biochemical measurements and histopathological changes in age-related kidney lesions of rats (author's transl)].

Histopathological observations were made on the spontaneous age-related kidney lesion in relation to some biochemical measurements for renal function using male SD rats from 82 to 560 days of age. Although all the rats examined were appearently healthy and had no gross lesions in the kidneys, several renal changes were detected histopathologically in the kidneys. The lesions occurred initially in renal tubules and then in glomerulus and in interstitial tissues successively increasing in severity with age. There was a correlation between the degree of the histopatholigical changes and the excreted amount of protein and sodium in the urine. The urinary protein was first detected at 34 days of age increasing with age. For rats of over 395 days of age, the urinary protein was greatly variable in amount among individuals. The negative correlation between urinary protein levels and those of serum albumin and urinary potassium was significant.

Aging↗
PubMed1978

Intracranial saccular aneurysms--surgical results of 1,000 consecutive cases.

The results of our surgical treatment of 1,000 patients with intracranial saccular aneurysm were analyzed with special consideration for age, site of aneurysm, preoperative condition and operative timing. The results on discharge were as follows: 543 cases, excellent; 186, good; 117, fair; 93, poor; and 61, dead. About three-fourths of the cases except for 23 cases of vertebrobasilar aneurysm showed either excellent or good result. The mortality rate became worse with aging. The results fairly correlated with the preoperative grades by Hunt and Hess (1968), but the cases of Grade Ia were unexpectedly worse. The timing of operation influenced the mortality rate; especially, the cases operated within 3 to 7 days following the last subarachnoid hemorrhage bore poor results. Follow-up studies revealed that excellent and good cases increased and poor cases decreased. The mortality rate for each year decreased annually to 2% in 1975. This improvement may be attributed to the advancement in the operative management with supplementary procedures and in the treatment for cerebral angiospasms and general condition.

Adult↗