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Biomedical subjects

H Terada

Publications and source records attributed to H Terada.

At least 217 records · Page 12Linked to original sources
PubMed1991

[Malignant histiocytosis with complex chromosomal abnormality: successful treatment with CHOP-E chemotherapy].

A 43 year-old man admitted to our hospital because of fever and splenomegaly. Laboratory findings were as follows: Hb 9.5 g/dl, Plts 4.9 X 10(4)/microliter, LDH 2,348 IU/l. Bone marrow findings showed tumor cell 47% with or without phagocytosis. The tumor cells were stained positive lysozyme and alpha 1 antitrypsin. Cytogenetic study was 47, XY, -7, -8, +9, -11, -12, -19, -21, 3q+, 6p+, +6 markers. This case was diagnosed as malignant histiocytosis. Complete remission was achieved with CHOP-E chemotherapy. Remission has been maintained with repeated this therapy. Etoposide deserves a good evaluation in the treatment of malignant histiocytosis. Some cases of malignant histiocytosis with a t(2; 5) (p23; q35) translocation were often reported in Europe and America, while there was no specific chromosomal abnormalities with malignant histiocytosis in Japan.

Adult↗
PubMed1991

[A case of delirium which occurred during otorhinolaryngological treatment under local anesthesia--the importance of close communication between practitioners and local general hospitals].

We experienced a case of delirium which occurred during treatment of chronic sinusitis under local anesthesia in a ENT practitioner, which took an unique course. We were able to treat the patient immediately after occurrence of the complication because we have emergency hot-line between anesthesiologists in our hospital and the practitioners in our area. Fortunately the patient recovered without severe sequelae due to immediate therapy. We consider that in emergency cases, a close communication between practitioners and local general hospitals is important for exact diagnosis and suitable treatments as well as for life-saving procedures.

Anesthesia, Local↗
PubMed1990

The triterpene celastrol as a very potent inhibitor of lipid peroxidation in mitochondria.

The inhibitory effect of the dienone-phenolic triterpene, celastrol, on lipid peroxidation in rat liver mitochondrial membranes induced by ADP and Fe2+ was studied. The anti-peroxidative effect of celastrol was very strong: its 50% inhibitory concentration was 7 microM, and it was about 15 times more effective than alpha-tocopherol. Celastrol scavenged 1.5 molar equivalents of radicals in homogeneous aqueous ethanolic solution, whereas cysteine and alpha-tocopherol scavenged one and two molar equivalents of radicals, respectively. The process of anti-peroxidation of celastrol was biphasic, possibly due to stepwise inhibitions of peroxidation in the outer and inner mitochondrial membranes.

Animals↗
PubMed1990

Effect of the weakly acidic uncoupler 2,4-dinitrophenol and dimethyl sulfoxide on the coordination of Mg2+ with ATP. Possible mechanism of activation of the isolated F1-ATPase by 2,4-dinitrophenol.

The exchange rate constants between Mg2(+)-free and Mg2(+)-bound ATP were determined under various conditions by line shape analysis of the 31P-NMR spectrum based on the exchange reaction, and the thermodynamic parameters of this exchange reaction were determined from the temperature dependence of its rate constants. Analysis of the activation enthalpy change delta H showed that Mg2+ is coordinated with the beta- and gamma-phosphoryl groups of ATP asymmetrically, being in closer proximity to the beta-phosphoryl group. The weakly acidic uncoupler 2,4-dinitrophenol increased this asymmetric coordination of Mg2+, and this effect was enhanced by the further addition of dimethyl sulfoxide. The hydrolysis of ATP in aqueous solution correlated well with the degree of asymmetry of Mg2+ coordination. Thus, this asymmetric coordination specifically weakens the O-P gamma bond at which specific cleavage of ATP catalyzed by most ATPases takes place in the presence of Mg2+. In this paper, the mechanism of activation of isolated ATPase (F1-ATPase) by 2,4-dinitrophenol, and that of ATP synthesis by isolated F1-ATPase in the presence of dimethyl sulfoxide are considered on the basis of these results. The essential role of the OH group of Ser-174 of the beta-subunit of F1-ATPase in ATP hydrolysis is also discussed.

2,4-Dinitrophenol↗
PubMed1990

Effects of the local anesthetic bupivacaine on oxidative phosphorylation in mitochondria. Change from decoupling to uncoupling by formation of a leakage type ion pathway specific for H+ in cooperation with hydrophobic anions.

The effects of the local anesthetic bupivacaine on the oxidative phosphorylation in rat liver mitochondria were examined. Bupivacaine caused a maximum of about 7-fold stimulation of state 4 respiration at about 3 mM, released oligomycin-inhibited state 3 respiration, and activated ATPase to a similar extent to that by the weakly acidic uncoupler SF 6847. These effects were greatly enhanced by the addition of certain hydrophobic anions such as 1-anilino-8-naphthalenesulfonate, tetraphenyl borate, and picrate. In the absence of these anions, bupivacaine did not increase the proton conductance in either energized or nonenergized mitochondrial membranes or in artificial bilayer lipid membranes and did not have any effect on the proton motive force. However, it greatly enhanced the proton conductivity of these membrane systems and collapsed the proton motive force in the presence of hydrophobic anions. The results of noise analysis of artificial lipid bilayer membranes indicated that an ion pair complex of bupivacaine with hydrophobic anions formed a leakage-type ion pathway. Thus it is concluded that bupivacaine acts as a decoupler in the absence of added hydrophobic anions but in cooperation with certain anions as an uncoupler of oxidative phosphorylation due to formation of a H(+)-specific pathway in the membranes.

Adenosine Triphosphatases↗
PubMed1990

Increased attachment and confluence of skin epidermal cells in culture induced by ascorbic acid: detection by permeation of trypan blue across cultured cell layers.

In culture epidermal cells from the skin of newborn rats became attached to Millipore filters coated with type IV collagen much better than to filters coated with type I collagen. Ascorbic acid markedly increased the attachment and viability of epidermal cells seeded on type I collagen, but had no significant effect on cells seeded on type IV collagen. It was also found to enhance the synthesis of type IV collagen by the cells, which, we concluded, enabled the cells to become well attached to type I collagen. This conclusion was supported by studies on the penetration of trypan blue through the cell layers. There was a lag in penetration through cell layers cultured both with and without ascorbic acid on Millipore filters coated with either type I or IV collagen, indicating that the cells were confluent over the whole surface of the filters. The lag was much longer in the cultures with ascorbic acid, indicating greater confluence and tighter attachment of cells due to production of type IV collagen. The penetration was found to be due to destruction of the confluent cell layers by its cytotoxic effect. The time lag before penetration of trypan blue is a good index of the confluence and attachment of cultured cells to collagen layers.

Animals↗
PubMed1990

Dual inhibitory effects of the peptide antibiotics leucinostatins on oxidative phosphorylation in mitochondria.

The effects of the hydrophobic peptide antibiotics leucinostatins A and B, originally isolated by Arai, T., Y. Mikami, K. Fukushima, T. Utsumi, and K. Yazawa. (J. Antibiotics (1973) 26: 157-161), on the functions of rat liver mitochondria were examined. At a concentration of 240 nM, these compounds completely inhibited state 3 respiration and ATPase activity that was stimulated by weakly acidic uncouplers. However, at higher concentrations, they induced uncoupling, probably by their protonophoric action. The uncoupling action was potentiated by known phosphoryl transfer inhibitors such as venturicidin, DCCD and oligomycin. The binding site of leucinostatins at lower concentrations was suggested to be located at, or very close to that of venturicidin. The potencies of the two analogues of leucinostatin were almost the same for all their actions. Their effects were very similar to those of the peptide antibiotics A20668's, which have been used as leucinostatins without any chemical and biological confirmation that they are in fact leucinostatins. Thus, the chemical structures of leucinostatins are thought to be analogues to those of the A20668's.

Adenosine Triphosphatases↗
PubMed1990

Transcellular permeation of nitrophenols through newborn rat skin epidermal cells in monolayer culture.

The permeation of nitrophenols through epidermal cells from newborn rat skin cultured on type IV collagen-coated Millipore filters was studied under various conditions. The order of permeation through the cultured skin cells was found to be p- greater than m- greater than o-nitrophenol at both 10 and 37 degrees C. This order was the same as that of their affinities to isolated skin cells. The permeation of nitrophenols was not inhibited by the inhibitors of energy transduction 2-deoxyglucose and NaN3. These results suggest that the permeation of nitrophenols across a cultured cell layer occurs by simple diffusion. The order of permeation of nitrophenols across newborn abdominal epidermis was exactly the opposite of that of their permeation across a cultured cell layer.

Animals↗
PubMed1990

Arrhythmia after the release of inhibited oxidative phosphorylation.

Automaticities due to delayed afterdepolarizations, elicited upon reoxygenation, are thought to be caused by Ca overload. Since tissue Ca uptake upon reoxygenation has been reported to be closely related to metabolic inhibition during hypoxic perfusion, the relationship between the degree of metabolic inhibition during hypoxia and reoxygenation-induced arrhythmias was investigated in guinea pig papillary muscles. (1) Arrhythmias occurred after 60 min substrate-free hypoxia, but not after 30 min hypoxia. The chance of automaticities was closely related with the increase in resting tension achieved during hypoxic period. The incidence of arrhythmias was, however, lower after 90 or 120 min hypoxia. (2) There were arrhythmias after 20-30 min hypoxia with glycolytic inhibition (20 mM 2-deoxyglucose + 5 mM acetate). On the other hand, 60-min hypoxia in the presence of 5 mM glucose did not elicit arrhythmias on reoxygenation. (3) Stimulation of glycolysis (50 mM glucose) during substrate-free hypoxia prolonged the action potential duration, but did not cause arrhythmias. Washout of cyanide (1 mM) after 60 min perfusion in the presence of oxygen, caused arrhythmias and aftercontractions. These results suggest that the degree of metabolic inhibition during hypoxia is closely related to Ca overload and the resultant arrhythmias upon reoxygenation. The release of inhibited oxidative phosphorylation, rather than the reintroduction of oxygen per se, was thought to be the key mechanism of reoxygenation-induced arrhythmias.

Animals↗
PubMed1990

Uncouplers of oxidative phosphorylation.

Uncouplers of oxidative phosphorylation in mitochondria inhibit the coupling between the electron transport and phosphorylation reactions and thus inhibit ATP synthesis without affecting the respiratory chain and ATP synthase (H(+)-ATPase). Miscellaneous compounds are known to be uncouplers, but weakly acidic uncouplers are representative because they show very potent activities. The most potent uncouplers discovered so far are the hindered phenol SF 6847, and hydrophobic salicylanilide S-13, which are active in vitro at concentrations in the 10 nM range. For induction of uncoupling, an acid dissociable group, bulky hydrophobic moiety and strong electron-withdrawing group are required. Weakly acidic uncouplers are considered to produce uncoupling by their protonophoric action in the H(+)-impermeable mitochondrial membrane. For exerting these effects, the stability of the respective uncoupler anions in the hydrophobic membrane is very important. High stability is achieved by delocalization of the polar ionic charge through uncoupler (chemical)-specific mechanisms. Such an action of weakly acidic uncouplers is characteristic of the highly efficient membrane targeting action of a nonsite-specific type of bioactive compound.

Acids↗
PubMed1990

Regional differences in peripheral circulation between upper and lower extremity in patients with cirrhosis.

In 42 patients with compensated cirrhosis and 31 control subjects, blood flow (BF) and vascular resistance (VR) were measured at the forearm and calf, using a pneumoplethysmograph. In some of the subjects deep-body temperature (DBT) was also measured by the zero heat flow method. In cirrhosis, BF and DBT were significantly higher and VR was significantly lower in the forearm than in the calf. Corresponding differences were not observed in control subjects. When these indices of the forearm were compared between cirrhosis and controls, BF and DBT were significantly higher and VR was significantly lower in cirrhosis than in controls. In cirrhotics in whom the gradient between forearm BF and calf BF was 1 ml.dl-1.min-1 or more (forearm greater than calf), the vascular response of the forearm to cold stimulation was reduced, whereas in the remaining patients and in controls the forearm BF and VR responded significantly. These results suggest that there is a regional difference in peripheral circulation in cirrhotics, partly with participation of impaired sympathetic nervous activity, which may account for the selective distribution observed in the clinical manifestations of vascular spider, palmar erythema, and warm hand, inclined toward the upper extremities or the upper part of the body.

Arm↗
PubMed1990

[Morphological analysis of the megakaryocytes in myelodysplastic syndrome].

Morphological features of megakaryocytes were studied in 31 patients with myelodysplastic syndrome. Mean nuclear size (N), mean cytoplasmic size (C) and mean N/C ratio were 586 +/- 105 mu 2, 1,391 +/- 327 mu 2 and 0.42 +/- 0.04, respectively. Cell sizes were found to be reduced in 12 patients compared to control subjects. Atypical megakaryocytes were frequently found in patients with RAEB and micromegakaryocytes were also often found in patients with CMML. Mean platelet volume was 0.9 +/- 1.6 fl and the giant platelets were seen in one patient with CMML. In the patients with presence of more than 10% of atypical megakaryocytes, template Ivy bleeding time prolonged and epinephrine- and collagen-induced aggregation decreased. We believe that reduction of megakaryocytes' size and appearance of micromegakryocytes would be helpful in diagnosis of MDS.

Blood Platelets↗
PubMed1990

[Philadelphia chromosome positive acute mixed lineage leukemia with bcr (M-BCR-1) rearrangement].

We report two cases of Philadelphia (Ph1) chromosome positive acute mixed lineage leukemia (AMLL) with breakpoint cluster region (bcr) (M-BCR-1) rearrangement. A 31 year-old-man (case 1) and a 42 year-old-woman (case 2) were admitted to our hospital for further evaluation of leucocytosis with atypical blasts. Each case was diagnosed as having bilineal type of AMLL because: (1) blasts in each case consisted of larger myeloid cells positive for myeloperoxidase and small lymphoid cells positive for PAS, and blasts in case 2 were positive for TdT; (2) blasts in case 1 expressed B lymphoid associated antigen; (3) Southern analysis in each case showed clonal rearrangements of both the immunoglobulin heavy chain and the T cell receptor beta gene. These two cases demonstrated the Ph1 chromosome and rearrangement of the bcr (M-BCR-1) gene, but none of splenomegaly, basophilia, and additional chromosome abnormalities were observed. In addition, after achieving remissions, they didn't revert to chronic phase of chronic myelogenous leukemia (CML) and showed normal neutrophil alkaline phosphatase scores, and the Ph1 chromosome disappeared completely in case 1 and coexisted with the normal chromosome in case 2. These findings suggest that diagnosis of both cases should not be CML blast crisis (BC) but Ph1 positive acute leukemia, and Ph1 positive AMLL may be a distinct clinical entity to be distinguished from CML-BC.

Adult↗
PubMed1990

[Hepatic and systemic hemodynamics in compensated cirrhosis--effect of posture change].

The effect of changes in body posture on estimated hepatic blood flow (EHBF) and various hemodynamic parameters was examined in 15 patients with compensated cirrhosis. EHBF and various hemodynamic parameters were first measured with the patients in the supine position, and then again 10 min after tilting to 45 degrees. EHBF was 1089 +/- 315 ml/min at supine and 1065 +/- 328 after tilting; the difference was not significant. However, the patients were then divided into two groups according to the magnitude of the decrease in EHBF after tilting, with those showing a decrease of 10% of more assigned to group B, and those showing a decrease of less than 10% assigned to group A. It was found that ICG (R15) and BSP (R45) were significantly higher in group A. Meanwhile, among hepatic and systemic hemodynamics, wedged hepatic venous pressure, hepatic venous pressure gradient, free hepatic venous pressure, cardiac index, systolic blood pressure, systemic vascular resistance, and stroke volume were found to have changed significantly after tilting. These results suggest that posture change has no effect on EHBF in compensated cirrhotic patients.

Aged↗