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Biomedical subjects

M Uchida

Publications and source records attributed to M Uchida.

At least 379 records · Page 21Linked to original sources
PubMed1988

[Effect of hypertension on asymmetrical septal hypertrophy: an echocardiographic study].

The effect of hypertension on asymmetrical septal hypertrophy was studied by echocardiography to differentiate idiopathic asymmetrical septal hypertrophy (ASH) from ASH with hypertension. One hundred eight patients with ASH proven by echocardiography were categorized in two groups; 53 patients with hypertension (greater than 160 systolic, greater than 95 diastolic) (hypertensive group: HT) and 55 patients with normal blood pressure (normotensive group: NT). Septal hypertrophy was classified as mid-portion (M-type), diffuse (D-type), and basal (B-type) hypertrophy by the long-axis view, and also diffuse (I-type), anterolateral (II-type), anteroseptal (III-type), and anterior septal (IV-type) by the short-axis view, respectively. Endomyocardial biopsy and left ventriculography were performed in 50 patients (18 hypertensives and 32 normotensives). In the hypertensive group, 45%, 30%, and 25% of cases had diffuse, basal and mid-portion hypertrophy, respectively. There was no case in the basal hypertrophy whose biopsy findings were compatible with hypertrophic cardiomyopathy. In the normotensive group, 78% and 22% of patients had midportion and diffuse hypertrophy, respectively, but none of them had the basal hypertrophy. Type IV was seen in only six patients in the normotensive group.

Adult↗
PubMed1988

[Mechanism of action of antineoplastic agents in the DNA synthesis of tumor cells].

The overall process of DNA biosynthesis can be divided into two major steps, one consisting essentially of nucleotide synthesis from low-molecular-weight metabolites and the other of polymerization of the nucleotides to form the duplicated DNA. Some antineoplastic agents are structural analogues of bases or nucleosides of intermediate metabolites, and are converted to their ribotides by enzymes catalyzing nucleotide metabolism. With some of these agents, the resulting ribotides then act as inhibitors of nucleotide synthesis. With others the resulting ribotides are subjected to stepwise enzymatic reactions and are then incorporated into DNA during its synthesis, thus rendering it inactive. Some antineoplastic agents, on the other hand, affect the DNA chain apparently through intercalation in double-stranded DNA, binding to DNA or nuclear protein, or interstrand linkage, or else through activation of endonuclease or inhibition of topoisomerase. The former effects result in inhibition of DNA double-strand dissociation, while the latter result in double-stranded DNA scission and apurinic acid formation. Antineoplastic agents thus vary widely, with respect to both the processes of their activation and inactivation and their effects on DNA synthesis. Their mechanisms of action and effects also tend to differ among various types of tumor cells and host organs. Investigation of the action mechanisms of these agents and determination of their appropriate utilization will be required in order to achieve better results in cancer chemotherapy.

Antineoplastic Agents↗
PubMed1987

Severe cardiovascular changes associated with pancuronium after cardiopulmonary resuscitation and after brain injury.

Severe hypertension, tachycardia or ECG changes have been reported following i.v. administration of pancuronium to patients with pheochromocytoma or bronchial asthma. These cardiovascular changes were explained by an interaction between autonomic effects of pancuronium and elevated serum catecholamines or aminophylline. We noted similar cardiovascular changes associated with i.v. administration of pancuronium in two patients after successful cardiopulmonary resuscitation and in two with midbrain hemorrhage and epidural hematoma. In these patients, pancuronium produced no abnormal cardiovascular changes when given during elective surgery or before the occurrence of midbrain hemorrhage. Thus, ischemic brain damage may play a role in producing the severe cardiovascular changes associated with pancuronium.

Aged↗
PubMed1987

Periungual fibroma.

Two cases of periungual fibroma of the hand are described. Lesions caused by periungual fibroma place pressure on the nail matrix, which results in marked nail deformities. In both cases, the nail deformities were improved by excision of the fibroma.

Adult↗
PubMed1987

Significance of phosphorylation/dephosphorylation of 46K protein(s) in regulation of superoxide anion production in intact guinea pig polymorphonuclear leukocytes.

Superoxide anion (O2-) production stimulated by concanavalin A (Con A) in guinea pig polymorphonuclear leukocytes (PMNL) was suppressed by addition of methyl-alpha-mannoside, a Con A inhibitor, and resumed upon readdition of Con A. The reversible change in the O2- production was assumed to reflect the change in NADPH oxidase activity measured for the 30,000 X g particulate fraction. The stimulation by Con A of the phosphorylation of 46K protein(s), as observed previously with several membrane-perturbing agents in parallel with an activation of NADPH oxidase in intact guinea pig PMNL (Okamura, N., et al. (1984) Arch. Biochem. Biophys. 228, 270-277), was also suppressed by methyl-alpha-mannoside and resumed upon readdition of Con A. Similar parallelism between the phosphorylation and NADPH oxidase activity was also observed in the case of stimulation by N-formyl-methionyl-leucyl-phenylalanine (FMLP) and phorbol 12-myristate 13-acetate (PMA), though both processes were reversible after the stimulation by FMLP but not reversible after that by PMA. Thus, such a parallelism observed in both intact PMNL and 30,000 X g particulate fraction indicates possible involvement of the protein phosphorylation in the regulation of the production of active oxygen metabolites in PMNL.

Animals↗
PubMed1987

Development and application of confined blasting for bladder and kidney stones.

Microexplosion lithotripsy (MEL) was clinically developed for the destruction of urinary stones in our clinic in 1981. In MEL two kinds of blasting are available: external charge blasting and confined blasting. The detonation power of the latter is 3 times larger than that of the former. Up to July, 1986, microexplosion cystolithotripsy has been successfully performed on 100 cases. In the early stages only external charge blasting was used. It was, however, not easy to crush a big bladder stone over 5 cm in diameter. For that reason, confined blasting was newly developed and in 50 cases microexplosion cystolithotripsy using confined blasting was completed successfully. As the next step, percutaneous nephrolithotripsy using confined blasting has been successfully performed on 12 cases including 3 of staghorn calculi.

Aged↗
PubMed1987

Immunoelectron microscopic localization of dopamine beta-hydroxylase and chromogranin A in adrenomedullary chromaffin cells.

Dopamine beta-hydroxylase (DBH) was purified from bovine adrenal medullae. Rabbit IgG raised against DBH inhibited its activity by 80%. In an immunoblot analysis, the IgG specifically recognized two subunits of DBH the 72 and 75 KD components. Chromogranin A (CGA) also was purified from bovine adrenal medullae, and rabbit IgG against CGA recognized this chromogranin A in the immunoblot analysis. The intracellular distribution of DBH and CGA in bovine chromaffin cells was determined quantitatively by immunoelectron microscopy using post-embedding protein A-gold technique. DBH and CGA were localized exclusively on chromaffin granules. The binding of gold particles to these granules was saturable. The maximum number of gold particles bound to the granules roughly corresponded to the number of DBH or CGA molecules in the granules estimated biochemically. DBH was observed evenly in the periphery and in the dense matrix of the chromaffin granules.

Adrenal Medulla↗
PubMed1987

[Effects of ifenprodil tartrate on erythrocyte deformability and cerebral blood flow].

Effects of ifenprodil tartrate on whole blood filtrability ex vivo in rats was investigated by a standard technique for measuring whole blood filtration time passed through a filter (5 micron). Ifenprodil tartrate was observed to reduce the filtration time dose-responsively. This effect was especially evident at 20 mg/kg (P less than 0.05). On the other hand, no effect on the hematocrit value, plasma concentration of fibrinogen, erythrocyte count or mean cellular volume of erythrocytes was observed. These results indicated the increasing effects ex vivo of ifenprodil tartrate on erythrocyte deformability. The ex vivo effects on erythrocyte deformability was manifested without changing the ATP contents, ATP/ADP ratio or adenylate energy charge in erythrocytes; and a phenothiazine-like amelioration in the shape of crenated erythrocytes was observed. These results suggested that the effect of ifenprodil tartrate on erythrocyte deformability ex vivo might be due to direct action on the erythrocyte membrane. At 0.3 mg/kg, i.v., ifenprodil tartrate significantly (P less than 0.05) increased the blood flow in the hypothalamus of conscious rats. Thus, it was indicated that ifenprodil tartrate, which increases the erythrocyte deformability and the cerebral blood flow, is useful for the therapeutic treatment of cerebrovascular accidents.

Adenine Nucleotides↗