Search PubMed⌕ Search

Biomedical subjects

Y Hara

Publications and source records attributed to Y Hara.

At least 757 records · Page 42Linked to original sources
PubMed1982

Lymphoid tumors of the orbit and ocular adnexa: a clinicopathologic study of 42 cases.

Clinicopathologic features of lymphoid tumors of the orbit and ocular adnexa were documented in 42 cases treated at the Kyushu University Hospital during the period from 1965 through 1980. There were 30 cases with malignant lymphoma and 12 cases with reactive lymphoid lesions. According to the new histological classification proposed by the Japanese Lymphoma Study Group for non-Hodgkin's malignant lymphoma, the malignant lymphoma group included 22 cases of small cell type, 3 cases of medium-sized cell type and 5 cases of large cell type. The small cell type tumors were further divided into two groups, those with and without monoclonal intracytoplasmic immunoglobulin (IgM or IgA). The former was usually located in the subconjunctival tissue and its local recurrence after extirpation was rare. A few cases showed intranuclear inclusions (Dutcher bodies). By electron microscopy, the cells were found to exhibit plasmocytoid differentiation: laminated rough endoplasmic reticulum was well developed and condensed heterochromatin was seen at the margin of the round nuclei. The latter group of small cell tumors was situated mainly in the anterior portion of the orbit and occasionally recurred after surgical removal and steroid therapy. These tumor cells showed no plasmocytoid differentiation, when studied by electron microscopy. The medium-size and large cell types presented clinicopathologic features similar to nodal lymphoma. In the reactive lymphoid lesions, polyclonal intracytoplasmic immunoglobulins were identified in the proliferating lymphoid cells.

Adult↗
PubMed1982

[Evaluation of the optimum method of administration of a new antineoplastic agent, HCFU, based on the serum 5-FU concentration following oral administration].

The serum concentration of HCFU and its metabolites was clinically studied to obtain the most useful information for optimal methods of oral administration of a new anticancer agent. In this paper, the serum level of the only 5-FU among metabolites of HCFU was discussed. High-performance liquid chromatography was used as monitoring the agent. The serum level of 5-FU usually reached a maximum one hour after oral administration of 200mg HCFU and remained more than 0.2 to 0.3 microgram/ml for at least two hours. When administered 200mg HCFU every 6 hours (800mg/day), the serum level of 5-FU could be maintained more than 0.1 micrograms/ml for 24 hours. When administered 200mg three times after each meal (600mg/day), its level could be maintained more than 0.1 microgram/ml only for daytime, but not at night. Consequently, we suggest that the most favorable therapeutic oral administration of HCFU might be 200 mg every 6 hours (800mg/day) to maintain the serum level of 5-FU over 0.1 microgram/ml for 24 hours.

Administration, Oral↗
PubMed1981

Ligand-dependent reactivity of (Na+ + K+)-ATPase with showdomycin.

Showdomycin inhibited pig brain (Na+ + K+)-ATPase with pseudo first-order kinetics. The rate of inhibition by showdomycin was examined in the presence of 16 combinations of four ligands, i.e., Na+, K+, Mg2+ and ATP, and was found to depend on the ligands added. Combinations of ligands were divided into five groups in terms of the magnitude of the rate constant; in the order of decreasing rate constants these were: (1) Na+ + Mg2+ + ATP, (2) Mg2+, Mg2+ + K+, K+ and none, (3) Na+ + Mg2+, Na+, K+ + Na+ and Na+ + K+ + Mg2+, (4) Mg2+ + K+ + ATP, K+ + ATP and Mg2+ + ATP, (5) K+ + Na + + ATP, Na+ + ATP, Na+ + K+ + Mg2+ + ATP and ATP. The highest rate was obtained in the presence of Na+, Mg2+ and ATP. The apparent concentrations of Na+, Mg2+ and ATP for half-maximum stimulation of inhibition (KS0.5) were 3 mM, 0.13 mM and 4 MicroM, respectively. The rate was unchanged upon further increase in Na+ concentration from 140 to 1000 mM. The rates of inhibition could be explained on the basis of the enzyme forms present, including E1, E2, ES, E1-P and E2-P, i. e., E2 has higher reactivity with showdomycin than E1, while E2-P has almost the same reactivity as E1-P. We conclude that the reaction of (Na+ + K+)- ATPase proceeds via at least four kinds of enzyme form (E1, E2, E1 . nucleotide and EP), which all have different conformations.

Adenosine Triphosphate↗
PubMed1981

Properties of ipsilateral retinogeniculate afferents in albino and hooded rats.

By recording single unit activities from the dorsal lateral geniculate nucleus in albino and hooded rats, physiological properties of the ipsilateral retinogeniculate afferents were compared with those of the contralateral ones. The results show that the ipsilateral retinogeniculate pathway was characterized by intermediate conduction velocities, relatively high incidence of the tonic response and the visual field representation of central 30 degrees from the vertical midline on both sides.

Afferent Pathways↗
PubMed1981

Sodium ion discharge from pig kidney Na+, K+-ATPase Na+-dependency of the E1P-E2P equilibrium in the absence of KCl.

The two phosphoenzymes (E1P and E2P) of Na+,K+-ATPase were measured as ADP-sensitive and K+-sensitive fractions. The sum of these fractions was nearly 1 in the range of 50 to 1,200 mM NaCl. The effects of Na+ on the levels of E1P and E2P, on the rate constant of E2P leads to E1P transition (k2), on the rate constant of E2P dephosphorylation (k3), on the rate constant of E1P leads to E2P transition (k1) and on the apparent equilibrium constant between E1P and E2P (Kapp) were examined. k1 was found to decrease with increasing Na+ concentration, whereas k2 increased. Kapp was found to be directly proportional to the third power of Na+ concentration. k3 increased with increasing Na+ concentration and saturated at about 1 M NaCl. These results are consistent with a simple model in which ATP hydrolysis occurs through effectively only two phosphoenzyme intermediates in the absence of K+ and three sodium ions are discharged cooperatively from the enzyme during the E1P leads to E2P conversion.

Adenosine Diphosphate↗
PubMed1981

[Incidence and prognostic implication of repetitive ventricular premature contractions detected by Holter monitoring (author's transl)].

Incidence and prognostic significance of repetitive ventricular premature contractions in various cardiac diseases were evaluated retrospectively with 593 consecutive patients referred for the 24-hour continuous electrocardiographic monitoring (Holter monitoring). Primary cardiac diagnoses for 308 patients with structural heart diseases included previous myocardial infarction (MI) in 151 patients, angina pectoris in 34, congestive cardiomyopathy (COCM) in 21, valvular heart disease in 29, hypertensive heart disease (HHD) in 18, conduction disturbance in 28, and other cardiovascular abnormalities in 17 patients. Other 285 patients (48%) had no known structural heart disease. Repetitive ventricular premature contractions (VPCs) was defined as the occurrence of self-terminating two (couplet), three (triplet) or more consecutive VPCs without associated hemodynamic sequelae. Holter monitoring was done with simultaneous two-channel recordings. Repetitive VPCs were seen in 96 patients; 17% of patients with MI, 52% of COCM and 7% of no structural hart disease. Among 308 patients with structural heart disease, 91 had congestive heart failure and 42% of these had repetitive VPCs, whereas only 17% of patients without congestive heart failure had repetitive VPCs. Coronary arteriographic and ventriculographic findings were reviewed in 91 patients with previous MI. Neither the degree of coronary artery involvements nor left ventricular ejection fraction had influence on the occurrence of repetitive VPCs. Four hundreds and sixty-nine patients under the age of 69 years were followed from 6 to 36 months (mean 19 months). Thirteen patients including 5 cases with MI (4% of the cases with MI), 4 with COCM (21% of COCM) and 4 with other structural heart disease (4% of other disease) died suddenly in the follow-up period. In the patients followed, 72 had repetitive VPCs and 9 of them died suddenly. These 9 patients consisted of 4 patients with MI (25% of the cases with MI having repetitive VPCs), 4 with COCM (40% of COCM) and 1 with other structural heart disease (3% of other disease). Thus, patients with MI or COCM had higher incidence of repetitive VPCs and they are at a high risk for sudden cardiac death.

Aged↗