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Biomedical subjects

M Hatano

Publications and source records attributed to M Hatano.

At least 271 records · Page 15Linked to original sources

Effects of dibutyryladenosine 3',5'-monophosphate on steroid biosynthesis in humans.

The effects of dibutyryladenosine 3', 5'-monophosphate (DBcAMP), a nucleotide analogue, on blood pressure, serum electrolytes and plasma corticoid concentrations were investigated in 10 normotensive healthy subjects who received a constant diet containing 5-8 g sodium chloride in hospital. The systolic blood pressure did not change after infusion of 0.25 or 0.33 mg/kg/min of DBcAMP for 20 min. On the other hand, the diastolic blood pressure was significantly decreased after the infusion of DBcAMP. The levels of serum sodium and potassium were significantly decreased after the infusion of DBcAMP. After infusion of 0.25 mg/kg/min of DBcAMP for 20 min, the changes in plasma levels of 6 corticoids [progesterone, deoxycorticosterone (DOC), 18-hydroxy-deoxycorticosterone (18-OH-DOC), corticosterone, cortisol and dehydroepiandrosterone sulfate (DHEA-S] revealed no significant changes. After infusion of 0.33 mg/kg/min of DBcAMP for 20 min, the plasma levels of cortisol, corticosterone and 18-OH-DOC were significantly increased and the changes in plasma levels of aldosterone showed a tendency to increase but this was not significant. The plasma levels of DOC and DHEA-S were not appreciably changed, while the plasma levels of progesterone were significantly decreased after the infusion of 0.33 mg/kg/min of DBcAMP. It is speculated therefore that DBcAMP may act to enhance the activity of the sodium-potassium pump and to promote steroid biosynthesis dose-dependently in humans.

Adrenal Glands↗

Heterogeneity of Epstein-Barr virus derived from a nasopharyngeal carcinoma that has transforming and lytic properties.

The biological activities of Epstein-Barr virus (EBV) from a human epithelial hybrid cell line derived from a nasopharyngeal carcinoma (NPC-KT) were studied. Low concentrations of virus from the NPC-KT cell line stimulated DNA synthesis of human cord blood lymphocytes (CBL) and induced CBL to form EBV nuclear antigen-positive continuous cell lines. The CBL exposed to higher doses of virus showed stimulated DNA synthesis 2 days after infection, followed by cell lysis. Virus from the NPC-KT cell line induced EBV-specific antigens in nonproducer Raji cells and reduced the colony-forming ability of the super-infected cells. The ratio of transforming activity to early antigen-inducing ability was not constant during cell passage. The data obtained suggest that NPC-KT clone 1 cells are producing virus with cytotoxic and transforming properties.

Antigens, Viral↗

[Long-term vasodilator therapy of chronic refractory heart failure in patients with dilated cardiomyopathy].

The effect of long-term vasodilator therapy (hydralazine, ecarazine or budralazine + isosorbide dinitrate) were evaluated for 20 patients with chronic congestive heart failure due to dilated cardiomyopathy (DCM) resistant to conventional therapy. There were 16 men and four women whose ages ranged from 30 to 74 years (mean 52 years). Fifteen patients were in NYHA class III, and five in class IV. All patients continued their previous therapeutic regimens during this study. Hemodynamic measurements were performed with a triple lumen flow-directed balloon-tipped catheter for 15 patients to evaluate the effects of vasodilator therapy. In the other five patients, heart rate, blood pressure, chest radiography for heart size (CTR) and M-mode echocardiography were monitored. The hemodynamic responses to the combined vasodilator therapy for 15 patients showed significant decreases in afterload and preload concomitant with an increase in cardiac output. The noninvasive evaluations of combined vasodilator therapy in five patients resulted in significant improvement in heart size and ejection fraction. In all 20 patients, symptoms were significantly improved. Side effects and drug toxicity were uncommon during vasodilator therapy. It is concluded that combined vasodilator treatment is the most ajunctive therapy for the management of severe refractory heart failure due to DCM. In addition, long-term nonparenteral vasodilators can be administered even in an outpatient clinic without hemodynamic monitoring.

Adult↗

[SAM sound studied by pulsed Doppler echocardiography].

The occurrence of a systolic sound in hypertrophic obstructive cardiomyopathy (HOCM) has been well known for more than 20 years. This was phonoechocardiographically regarded as the sound coincident with the abrupt halt of the systolic anterior movement (SAM) of the mitral valve echo, and it has been termed the SAM sound. A 58-year-old man with HOCM was admitted with right hemiplegia. He was found to have a SAM sound which waxed and waned in intensity, and at times moved earlier into systole. He was studied by cardiac catheterization, M-mode and two-dimensional Doppler echocardiography (pulsed, continuous wave and color flow Doppler methods). Asymmetric septal hypertrophy (interventricular septal thickness = 25 mm, left ventricular posterior wall thickness = 14 mm), as well as SAM and midsystolic aortic valve closure were demonstrated. The presence and intensity of the sound was not related to rhythm (normal sinus rhythm vs atrial flutter), heart rate, respiration, position, or inhalation of amyl nitrite. Two-dimensional Doppler echocardiography revealed the following: 1. In the left ventricular outflow tract just below the aortic valve, a systolic turbulent flow was always present. 2. In the left ventricular chamber near the apex, a systolic laminar flow was interrupted in those cycles where the SAM sound was present. Otherwise, in cycles lacking the SAM sound, laminar flow in this locality continued throughout systole (even shorter duration than normal). 3. In the left ventricular inflow tract, diastolic flow was unaffected by the presence of the sound. 4. No mitral regurgitation was observed using color flow Doppler echocardiography. In summary, a SAM sound appeared to be associated with sudden deceleration of blood flow from the apex to the mid left ventricle.

Cardiomyopathy, Hypertrophic↗

Monoclonal antibody which has the neutralizing activities for human IL-2.

Six monoclonal antibodies against recombinant human interleukin-2 (IL-2) were successfully prepared by fusing NS-1 with spleen cells of BALB/c mice immunized with human recombinant IL-2. The specificities of these monoclonal antibodies were confirmed. By enzyme linked immunosorbent assay (ELISA) method, the antibody concentrations of each ascitic fluid obtained from BALB/c-nu/nu transplanted with the established hybridoma clones were varied for 10(3) to 10(5) depending on the clone. By SDS-PAGE analysis with immunoprecipitates formed between monoclonal antibodies and recombinant human IL-2, all monoclonal antibodies reacted unequivocally with recombinant human IL-2. Two monoclonal antibodies (designated as KNT-1 and KNT-2) out of six established clones reacted with natural human IL-2 molecule obtained from cultured human peripheral blood lymphocytes (PBL) stimulated with PHA-P and TPA. KNT-1 and KNT-2 monoclonal antibodies have inhibitory effects on the proliferative response of natural killer (NK-7) cell (one of the IL-2 dependent cultured cell lines) elicited by recombinant, natural human, or natural rat IL-2. Monoclonal antibody, KNT-1, inhibited activities of both recombinant or natural human IL-2, but did not neutralize activities of IL-2, derived either from murine EL-4 or from rat spleen cells. Another monoclonal antibody, KNT-2, had neutralizing activity for either recombinant or natural human IL-2 and eliminated the activity of rat-derived IL-2, but did not interfere with the activity of murine IL-2. The remaining four monoclonal antibodies (designated as KNT-3, -4, -5 and -6) did not affect the proliferative response of NK-7 cells elicited by natural human, rat and murine IL-2. These observations indicate that functional portion(s) of IL-2 molecules from different species have somewhat different structures.

Animals↗

Effect of dimethyl sulfoxide on interaction of human cytomegalovirus with host cell: conversion of a nonproductive state of cell to a productive state for virus replication.

The effect of dimethyl sulfoxide (DMSO) on the interaction of human cytomegalovirus (HCMV) with host cell was studied. Confluent state of a human rhabdomyosarcoma cell line (A204) showed a much lower susceptibility to HCMV infection when compared to that in subconfluent actively growing cell cultures. Treatment of confluent cultures with DMSO, however, converted many nonproductive cells in these cultures to a productive state for virus replication. Infectious center assay revealed that approximately 100-fold more cells in the compound-treated cultures are able to produce infectious virus. The amount of infectious virus produced in DMSO-treated confluent cultures was enhanced by approximately 10,000-fold over production in untreated cultures and recovered to the level of that produced in subconfluent cultures productive state for virus replication. This cell physiology-dependent inhibition of HCMV replication and enhancement of virus growth by DMSO did not occur with herpes simplex virus type 2. Immunofluorescence staining, gel electrophoresis, and DNA analyses indicate that block of HCMV replication in confluent cultures probably occurs at the level of early transcription or translation of the viral genome. In contrast, in DMSO-treated confluent cultures appreciable amounts of HCMV DNA polymerase (an early virus function), viral DNA, and late antigens were synthesized. Pretreatment of confluent cultures with DMSO enabled the cells to support HCMV replication. In addition, the most effective enhancement by DMSO was found in cultures that had been treated with the compound up to 5 hr after infection. These results suggest that the enhancing effect by DMSO is primarily expressed through some host cellular function(s) and the early stages in virus growth cycle are most likely under control by DMSO action.

Antigens, Viral↗