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Biomedical subjects

F Komada

Publications and source records attributed to F Komada.

52 records · Page 3Linked to original sources
PubMed1991

Improvement in wound healing by epidermal growth factor (EGF) ointment. II. Effect of protease inhibitor, nafamostat, on stabilization and efficacy of EGF in burn.

The healing effect of human epidermal growth factor (hEGF) on second degree burn was studied in rats. No improvement in wound healing was found on topical application of EGF alone to burn sites, but an ointment containing EGF and nafamostat mesilate (NM), a protease inhibitor, accelerated the healing rate of burns. The dry weight of the granulation tissue on the wound site in the group treated with EGF plus NM ointment did not change, although that in other groups decreased. After treatment with EGF ointment containing NM, the content of uronic acid, as an index of acid mucopolysaccharide, at 3 d after burn rapidly increased and had recovered to nearly normal levels at 7 d after burn. However, the uronic acid content in the other groups (control, EGF alone, and NM alone) showed a higher value at 7 d than at 3 d. When compared with the control values significant increases in hydroxyproline, as an index of collagen, in the wound site were observed at 7 d after treatment with EGF ointment containing NM. The degradation of [125I]EGF in burned tissue homogenate decreased significantly in a concentration-dependent manner in the presence of NM. Body weights did not change after treatment with EGF plus NM ointment, although the body weights of other treatment groups decreased after burn, suggesting that EGF ointment containing the protease inhibitor, NM, alleviated the effects of burn shock. These findings indicate that the stabilization of EGF at the wound site is an important factor for the expression of its healing effects.

Animals↗
PubMed1990

A role for calmodulin in the growth of human hematopoietic progenitor cells.

A possible role for calmodulin in the colony growth of human hematopoietic progenitor cells was investigated using pharmacologic approaches. We obtained evidence for a dose-dependent inhibition of colony formation of myeloid progenitor cells (CFU-C) stimulated by interleukin-3 (IL-3), granulocyte-macrophage colony-stimulating factor (GM-CSF), or granulocyte CSF (G-CSF) by three calmodulin antagonists, N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide hydrochloride (W-7), N-(4-aminobutyl)-5-chloro-2-naphthalenesulfonamide hydrochloride (W-13), and trifluoperazine. Chlorine-deficient analogs of W-7 and W-13, with a lower affinity for calmodulin, did not inhibit the growth of CFU-C colonies. W-7, W-13, and trifluoperazine inhibited the colony formation of immature erythroid progenitor cells (BFU-E) stimulated by IL-3 plus erythropoietin (Ep) or GM-CSF plus Ep, in a dose-dependent manner, while they did not affect the colony formation of mature erythroid progenitor cells (CFU-E) induced by Ep. W-7, W-13, and trifluoperazine also led to a dose-dependent inhibition of GM-CSF-induced colony formation of KG-1 cells. Calmodulin-dependent kinase activity derived from the KG-1 cells was inhibited by these three calmodulin antagonists in a dose-dependent manner. These data suggest that calmodulin may play an important regulatory role via a common process in the growth of hematopoietic progenitor cells stimulated by IL-3, GM-CSF, and G-CSF. Mechanisms related to the growth signal of Ep apparently are not associated with calmodulin-mediated systems.

Bone Marrow Cells↗
PubMed1990

Decreased expression of type II protein kinase C in HL-60 variant cells resistant to induction of cell differentiation by phorbol diester.

To evaluate the molecular basis for susceptibility of the cell differentiation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA), we examined biochemical activities and expression of subspecies of protein kinase C from HL-60 cells that are susceptible to differentiation induced by TPA and HL-60R cells, HL-60 variant cells that are resistant to such induction. Analysis of the subcellular distribution of protein kinase C revealed that the activity of this kinase in the cytosol from HL-60R cells was 30% of that from parental HL-60 cells but that the enzyme activities in the membrane showed similar values in these cells. Treatment of HL-60 cells with 100 nM TPA for 30 min resulted in a 75% decrease in protein kinase C activity in the cytosol and a 300% increase in this activity in the membrane. A minor subcellular redistribution of the enzyme activity was found in HL-60R cells after TPA treatment. Based on analysis of protein kinase C isozymes by hydroxyapatite column chromatography, the relative activities of types I, II, and III in the cytosol of HL-60 cells were 11, 80, and 9%, whereas those in HL-60R cells were 27, 36, and 37%, respectively. Type II isozyme was a major protein kinase C in the cytosol of HL-60 cells, but type II was less in the HL-60R cells. Among the three isozymes, type II enzyme was most sensitive to TPA with histone H1 as the substrate, although all three isozymes were activated Ca2+-dependently in the presence of phosphatidylserine. We suggest that the acquired resistance of HL-60R cells toward induction of cell differentiation by TPA may be associated with a decrease in the expression of the type II isozyme of protein kinase C.

Blotting, Western↗
PubMed1990

Improvement in wound healing by epidermal growth factor (EGF) ointment. I. Effect of nafamostat, gabexate, or gelatin on stabilization and efficacy of EGF.

The healing effect of human epidermal growth factor (hEGF) on open wounds was studied in rats. No improvement in wound healing was found by topical application of EGF alone to open wound sites. We found an ointment containing EGF and a protease inhibitor, nafamostat mesilate or gabexate mesilate, or gelatin accelerated the healing rate of open wounds. Significant increases in the dry weight of the wound site granulation tissue, uronic acid (as an index of acid mucopolysaccharide) and hydroxyproline (as an index of collagen) were observed by treatment with EGF ointment containing nafamostat compared with the controls. The effects of the protease inhibitor on wound healing were dose dependent. Nafamostat was more efficient than gabexate or gelatin on wound healing. The degradation of 125I-EGF in wound tissue homogenate was significantly decreased in the presence of a protease inhibitor, such as nafamostat or gabexate, or gelatin. These findings indicate that the stabilization of EGF at the wound site is an important factor in permitting the expression of its healing effects and suggest that the ointment containing EGF and a stabilizing agent would be a suitable dosage form for acceleration of wound repair.

Animals↗
PubMed1990

[Aplastic anemia which terminated in hypoplastic leukemia 10 years after diagnosis].

A 57-year-old woman was admitted to our hospital because of further examination of anemia in November, 1978. She was diagnosed as having aplastic anemia, which was not associated with any atypical findings. Treatment with oxymetholone had been effective. However, she developed pancytopenia in January, 1988. A bone marrow aspiration revealed a hypocellular marrow with 75.6% blasts. Following two courses with low dose cytosine arabinoside and vitamin D3, the leukemia improved although she needs red cell transfusions at intervals of one to two months because of persistent pancytopenia. We present a patient with aplastic anemia who developed a hypoplastic leukemia at the tenth year of the disease.

Anemia, Aplastic↗
PubMed1990

[A case of complete remission from acute unclassified leukemia achieved by using a prodrug of ara C, stearyl-ara-CMP (YNK01)].

YNK01 (a daily oral dose of 450 mg) was administered for 22 days to a 58-year-old-female with Ph1-positive acute unclassified leukemia. Leukemia cells were negative for peroxidase and esterase, but were positive for CD19, CD13, CD34, CD9, HAL-DR, CD25, and TdT. Complete remission was obtained and continued for at least a month. The main side effects noted were diarrhea and melena. The administration of YNK01 resulted in plasma ara C levels that ranged between 15.4 to 23.0 ng/ml, which appear to be nearly equivalent to dose achieved during continuous IV infusion of a low dose (20 mg/m2/day) of ara C.

Acute Disease↗
PubMed1989

Alteration of intracellular actin levels induced by phorboldiester in human HL-60 leukemia cells susceptible or resistant to differentiation, and the effects of protein kinase inhibitors.

During monocyte-macrophage differentiation of HL-60 cells by 12-O-tetradecanoyl phorbol 13-acetate, the intracellular globular(G)-actin and polymerized(F)-actin increased 3-fold and 1.7-fold, respectively. Time course studies showed that these changes of actin levels were nearly coincident with the development of macrophage characteristics, including adhesiveness, positive reactivity against OKM-1 antibody and elevated lysozyme activity. When exposed to 5 nM TPA, these different properties of differentiation were detectable as early as 12 h after TPA treatment and reached a maximum by 24 h. Phosphorylation of 17 K and 27 K proteins, induced by TPA, occurred early (within 30 min) during TPA-induced differentiation. On the other hand, HL-60R cells, which are resistant to TPA in terms of the development of adhesiveness and differentiation, showed no change in both G- and F-actin levels, after the TPA treatment. TPA did not induce phosphorylation of these proteins in the HL-60R cells. In the presence of the protein kinase inhibitors, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H-7, 20 microM) and staurosporine (10 nM), the increase in actin levels induced by TPA was inhibited as well as other later evidence of differentiation. These results suggest that the phosphorylation of specific proteins is closely associated with the process of differentiation of HL-60 cells into macrophages.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1989

Enhanced bioavailability of subcutaneously injected insulin coadministered with collagen in rats and humans.

The present study was undertaken to develop an agent that stabilizes insulin injected subcutaneously. 125I-Porcine insulin with 0.2 U/kg unlabeled porcine insulin was subcutaneously injected with or without collagen in the rat under the depilated skin of the back. At various times, the radioactivity in subcutaneous tissue was assayed for insulin and its metabolites by gel filtration. The degradation and absorption rate constants of insulin at the subcutaneous injection site were estimated according to a one-compartment model. The degradation rate constant of insulin in the presence of collagen at the injection site was less than half of the control rate. The inhibition was confirmed by increases in the immunoreactive insulin plasma levels and the hypoglycemic effect in rats and healthy volunteers. We postulate that collagen prevents insulin from being degraded by inhibiting proteolytic enzymes, mainly collagenase-like peptidase, in subcutaneous tissue.

Animals↗
PubMed1989

The signal transduction systems and intracellular Ca2+ dynamics in arachidonate-induced platelet activation.

Types II and III protein kinase C were expressed in human platelets and showed slightly different modes of activation and kinetic properties. Type III isozyme was more sensitive than type II for the activation of each isozyme with arachidonate (AA) although both isozymes were activated by diacylglycerol and phosphatidylserine in a similar manner. When human platelets were stimulated by AA, two types of platelet activation, a low level of AA (0.1-2.5 micrograms/ml)- and a high level of AA (10-50 micrograms/ml)-induced activations, were observed. These activations were associated with the phosphorylation of 40K and 20K proteins. Although a low level of AA (0.45-10.0 micrograms/ml) induced the formation of [32P] phosphatidate in intact platelets prelabeled with [32P] Pi, AA at high concentrations (20-50 micrograms/ml) did not stimulate phospholipase C. The incubation of fura 2 loaded platelets with a low level of AA evoked a rapid and transient elevation in [Ca2+] i. In contrast, a high level of AA induced an irreversible increase in [Ca2+] i but this [Ca2+] i elevation alone was not associated with platelet activation. These results suggest that the signal transduction system by a high level of AA on human platelets is different from that seen with a low level of AA. A high level of AA induces platelet activation, without phospholipase C stimulation, and therefore, the ability of AA to directly activate protein kinase C (pre-dominantly type III isozyme) may contribute toward the activation of platelets by a high level of AA.

Arachidonic Acid↗
PubMed1988

Clinical response to busramustine (KM-2210) in chronic lymphocytic leukemia: a pilot evaluation of estrogen receptor in relation to its therapeutic effect.

Busramustine (KM-2210), the benzoate of a 17 beta-estradiol-chlorambucil conjugate, was administered to 11 patients with chronic lymphocytic leukemia (CLL) which included eight cases of B-cell CLL and three cases of T-cell CLL. Four patients had received prior chemotherapy. Busramustine was given orally at an initial daily dose of 50-100 mg continuously, and the dose was modified according to hematological improvement. Two cases of B-cell CLL achieved clinical complete responses, six cases including two of T-cell CLL and four of B-cell CLL achieved partial responses and one case of B-cell CLL achieved improvement. The partial and complete response rate was 72.7%. Four patients showed estrogen receptor activity of CLL cells ranging from 3.5 to 57.5 fmol/mg cytosol protein, but there seemed to be no correlation between the estrogen receptor activity of the CLL cells and the therapeutic effects of busramustine. Toxic effects included diarrhea (2/11) and estrogen-related symptoms including breast pain (4/11), genital bleeding (2/5), gynecomastia (2/6) and loss of libido (2/6). The findings of this preliminary study suggest that busramustine is effective in the treatment of CLL, irrespective of the presence of the estrogen receptor.

Adult↗
PubMed1985

Fate of porcine and human insulin at the subcutaneous injection site. I. Degradation and absorption of insulins in the rat.

The plasma insulin and serum glucose levels were compared after the subcutaneous and intravenous administration of porcine and human insulin in rats. While no difference was observed in plasma insulin or serum glucose levels with either insulin after intravenous administration, the plasma insulin levels and hypoglycemic effects of human insulin were greater than those of porcine insulin after subcutaneous administration. At various time intervals, radioactivity in subcutaneous tissue was assayed for insulin and/or its metabolites by gel filtration. Using these data, the absorption and degradation rate constants of these substances were estimated according to a one-compartment model. The degradation rate constants of human insulin was approximately half of that for porcine insulin.

Anesthesia↗
PubMed1985

Fate of porcine and human insulin at the subcutaneous injection site. II. In vitro degradation of insulins in the subcutaneous tissue of the rat.

We compared the in vitro degradation of porcine and human insulin in the subcutaneous tissue of rat. The insulin degrading activity was largely confined to the 160000 X g supernatant fraction of subcutaneous tissue. The degradation of human insulin was approximately half that of porcine insulin in the supernatant fraction. The degradation of porcine insulin in subcutaneous tissue was inhibited by bacitracin, leupeptin, phosphoramidon, and Z-Gly-Pro-Leu-Gly, though the human insulin degradation was not. The degradation of both insulins was accelerated by glutathione. While the proteolytic enzyme activities of cathepsin-B and collagenase-like peptidase were detectable in subcutaneous tissue, chymotrypsin, elastase, kallikrein, alpha-thrombin, and trypsin activities were almost negligible. These in vitro studies suggest that human insulin is comparatively stable against proteolytic enzymes, probably collagenase-like peptidase or cathepsin-B, in the subcutaneous tissue, which support the in vivo evidence.

Animals↗
PubMed1983

Pharmaceutical approach to subcutaneous dosage forms of insulin.

The present studies were undertaken to describe the dynamic nature of the degradation and absorption of insulin in the subcutaneous injection site and to develop agents which would stabilize this dosage form. [125I]Insulin with 0.2-U/kg of unlabeled insulin in 10 microliters of aqueous solution was injected subcutaneously in rats under the depilated skin of the back. At various times, radioactive skin tissue was extracted and assayed for insulin and/or its metabolites by gel filtration. Using these data, absorption and degradation rate constants of these substances were estimated according to a one-compartment model. Absorption rate constants of insulin and its metabolite of low molecular weight (monoiodotyrosine) were 0.021 min-1 and 0.107 min-1, respectively, while the degradation rate constant for insulin to monoiodotyrosine was 0.013 min-1. Thus, the bioavailability of insulin injected subcutaneously was lower than expected, suggesting the necessity of stabilizing methods. The protection of insulin from degradation at the site of injection was examined by the addition of various peptides. It was found that benzyloxycarbonyl-Gly-Pro-Leu-Gly was a good stabilizing agent, and remarkably inhibited insulin degradation. This inhibition was confirmed by the increase of immunoreactive insulin level and the decrease of the blood glucose level. We postulated that this peptide protects the injected insulin from degradation by inhibiting the peptidase present in subcutaneous tissue.

Animals↗
PubMedDate not supplied

Effect of atropine on gastrointestinal motility and the bioavailability of cyclosporine A in rats.

The effect of atropine on gastrointestinal motility and the bioavailability of cyclosporine A (CyA) was studied in rats. Atropine dose-dependently inhibited gastrointestinal motility, and the ID20 and ID50 doses of atropine were chosen to study the bioavailability of CyA. After oral administration of CyA, the bioavailability was about 27%, and with increasing doses of atropine the area under the concentration-time curve and the peak blood concentration of CyA decreased. Atropine had no significant effect on the time of peak blood concentration (Tmax) and the mean residence time. These data suggested that there was prehepatic metabolism of CyA; thus a luminal perfusion study was performed. When CyA was perfused through rat stomachs by a recirculation method, the content of CyA in the perfusate rapidly decreased. However, the tissue content of CyA was not very high. These results indicate that changes in gastrointestinal transit as well as gastrointestinal metabolism of CyA may be important causes of the wide variability of its absorption in humans.

Administration, Oral↗