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Biomedical subjects

K Kaku

Publications and source records attributed to K Kaku.

At least 73 records · Page 4Linked to original sources
PubMed1994

Identification of the site of mutation within the M2 region of the GABA receptor of the cyclodiene-resistant German cockroach.

The DNA and amino acid sequences of the membrane-spanning region of the GABA receptors of the German cockroach have been identified along with information on the nature and the specific site of mutation in the cyclodiene-resistant strains. In this resistant strain, the mutation has occurred at the most conserved, lower M2 cylinder region involving a G to T conversion, resulting in an amino acid change of alanine (GCC) residue to serine (TCC). The site, furthermore, coincides with the most conserved region of all GABA receptor subunits and the expected Cl- transporting segment constituting the innermost surface of the channel opening. The deduced sequence of the German cockroach GABA receptor differs from that of Drosophila mainly in the connecting region between M3 and M4.

Animals↗
PubMed1994

[A successful delivery three years after the onset of multiple fungal liver abscess in a patient with acute lymphoblastic leukemia].

A 25-year-old woman was diagnosed as having the multiple fungal liver abscess which developed just after the re-induction chemotherapy, 13 months after the onset of acute lymphoblastic leukemia. Although chemotherapy for leukemia was suspended, her leukemia did not relapse. The multiple fungal liver abscess was successfully treated with anti-fungal drugs for the following 12 months. Three years after the onset of the fungal abscess, she married, became pregnant and vaginally delivered a healthy female infant at full term. In this way, it was demonstrated that a normal pregnancy and delivery could be expected even in patients who had received intensive chemotherapy and had recovered from the fungal abscess.

Adult↗
PubMed1994

[Defects of candidate genes in Japanese NIDDM--glucose transporter gene(GLUT1 gene, GLUT4 gene)].

To assess the contribution of GLUT1 and GLUT4 genes to NIDDM susceptibility in Japanese population, we performed population studies using RFLP markers. We found the strong association between XbaI polymorphism at GLUT1 gene and NIDDM, but no association between KpnI polymorphism at GLUT4 gene and NIDDM. Based on these results, molecular scanning of GLUT1 gene was performed using SSCP and direct sequencing in Japanese population, to substantiate the gene defect predisposing to NDDM. Although silent mutations were found, the meaningful mutations within the coding regions were not demonstrated. Thus the positive association observed in population study may be spurious or due to the abnormalities in non-coding regions such as promoter or other regulatory elements at GLUT1 gene.

Asian People↗
PubMed1994

[Human glucagon-like peptide-1 receptor gene in NIDDM].

Glucagon-like peptide-1 (GLP-1) stimulate glucose dependent insulin secretion from beta-cells. Human cDNA and the gene of the receptor for the GLP-1 was isolated. Two polymorphic simple tandem repeats were found in the gene. Using these markers, role of GLP-1 receptor mutations in the pathogenesis of NIDDM was studied. No association was found between the marker alleles and NIDDM in African American or in Japanese. Linkage was rejected between the GLP-1 receptor gene and NIDDM in Caucasian late-onset NIDDM families and in French MODY families. Mutations in the GLP-1 receptor gene do not appear to be major genetic determinants of NIDDM. Further studies are required to exclude the minor role of the gene in a fraction of NIDDM patients.

Asian People↗
PubMed1993

The inhibitory effect of tolbutamide on phosphoenolpyruvate carboxykinase activity in rat hepatoma H4IIE cells.

Effects of tolbutamide on the activity of hepatic phosphoenolpyruvate carboxykinase (PEPCK), a rate limiting enzyme in gluconeogenesis, was examined using rat hepatoma (H4IIE) cells. Tolbutamide inhibited PEPCK activity induced by cAMP in a time- and dose-dependent manner. Tolbutamide effect was rapidly exerted and insulin-independent. The inhibitory effect of 5 mM tolbutamide corresponded with that of 10(-7) M insulin. These results suggest the possibility that tolbutamide plays a significant role on amelioration of the deranged glucose metabolism in the liver through repression of gluconeogenesis, primarily due to the inhibition of PEPCK activity.

Animals↗
PubMed1993

Effect of granulocyte-macrophage colony-stimulating factor on chemotherapy-induced granulocytopenia in patients with malignancies.

To investigate the effect of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) on cytotoxic chemotherapy-induced granulocytopenia, we performed an open nonrandomized clinical trial in 46 patients with malignancies receiving cytotoxic chemotherapy regimen. Twenty-six patients who received two cycles of the identical chemotherapy regimen and had granulocytopenia less than 1 x 10(9) cells/l after the first cycle of chemotherapy were eligible for this study. They received 60, 125 or 250 micrograms/m2/day of rhGM-CSF randomly. The nadirs of peripheral granulocytes demonstrated significantly much higher levels in all dosages studied than those of control cycles. The duration of granulocytopenia was shortened with rhGM-CSF support. Such granulocyte recovery appeared in parallel with increasing dosages of GM-CSF, thus, infections with febrile episodes were reduced. Toxicity of rhGM-CSF was generally well tolerated.

Adult↗
PubMed1993

Phase II study of recombinant human granulocyte-macrophage colony-stimulating factor in myelodysplastic syndrome and aplastic anemia.

As phase II study, we treated 18 patients with myelodysplastic syndrome (MDS) and 37 patients with aplastic anemia (AA) with recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) for 14-28 days. Administration of rhGM-CSF resulted in a dose-dependent increase in circulating granulocyte counts, which was statistically significant in patients with AA. There were no consistent changes in monocyte and lymphocyte counts. Although no increase in both thrombocyte and erythrocyte counts was detected in the majority of the patients, a response of both lineages to rhGM-CSF, in addition to granulocyte lineage, was observed in 3 patients. Drug-associated adverse events developed in 28 patients (51%). The most frequent adverse event was fever. In general, the treatment with rhGM-CSF was well tolerated. The results suggest that rhGM-CSF is effective for patients with MDS and AA.

Adolescent↗
PubMed1993

Polymorphic microsatellite repeat markers at the glucokinase gene locus are positively associated with NIDDM in Japanese.

To assess the possible role of glucokinase defects contributing to a genetic susceptibility to NIDDM in Japanese, allelic frequencies of two microsatellite repeat polymorphisms, one in the 3'-flanking region (GCK1) and the other in the 5'-flanking region (GCK2) of the human glucokinase gene, were analyzed in subjects with NIDDM and in nondiabetic control subjects. After typing 107 diabetic and 74 nondiabetic subjects, we found four GCK1 alleles (Z, Z2, Z4, Z6) and six GCK2 alleles (0, -4, -2, 2, 4, 8). The frequency distribution of GCK1 alleles was different between the two groups (P = 0.005), although not significant after correction for multiple comparisons. The Z4 allele was found more frequently in diabetic than in nondiabetic subjects (23 vs. 10%, P = 0.002). This was still significant after correction for multiple comparisons (P < 0.05). The frequency distribution of GCK2 alleles was not different between the two groups. However, the -2 allele was more common in diabetic than in nondiabetic subjects (P = 0.044), although not significant after adjusting for multiple comparisons. Clinical characteristics were compared between the diabetic subjects with Z4 and/or -2 allele and those without either of these two alleles. No differences were found in the age of diagnosis, positive family history, mode of therapy, current HbA1c, or daily urinary C-peptide immunoreactivity excretion between the two groups. We demonstrated a significant association between GCK1 and GCK2 alleles and NIDDM. The results indicate that the polymorphic alleles GCK1 and GCK2 could be genetic markers in NIDDM in Japanese, suggesting a relationship between glucokinase defects and the susceptibility to NIDDM in this population.

Adult↗
PubMed1993

Recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) after chemotherapy in patients with non-Hodgkin's lymphoma; a placebo-controlled double blind phase III trial.

To assess the clinical and hematopoietic effects of rhGM-CSF, a placebo-controlled double blind multicenter phase III study was undertaken in patients with non-Hodgkin's lymphoma receiving cytotoxic chemotherapy. Sixty-two patients who had granulocytopenia (< 1 x 10(3)/microliters) after the first cycle of chemotherapy with cyclophosphamide, adriamycin, vincristine, and prednisolone were enrolled. After the second cycle of chemotherapy with the same regimen, patients randomly received either rhGM-CSF (125 micrograms/m2/day) or placebo for 14 days (rhGM-CSF; 31 patients and placebo; 31 patients). Administration of rhGM-CSF induced a significant increase in granulocytes mainly with neutrophils, eosinophils and monocytes, but elevation of lymphocytes, platelets, and reticulocytes was not induced. Median days of granulocytes less than 1 x 10(3)/microliters in patients receiving rhGM-CSF were significantly shorter than in patients receiving placebo (p = 0.001). Adverse reactions encountered with rhGM-CSF, and observed in 58% of the patients were never life-threatening and always rapidly reversible. They included fever, nausea and vomiting, diarrhea, skin eruption, and malaise. These results suggest that rhGM-CSF can be safely administered to prevent neutropenia after chemotherapy in patients with non-Hodgkin's lymphoma.

Adolescent↗
PubMed1993

[Chemotherapy with imipenem/cilastatin for severe infections accompanied by malignant hematological disorders].

The clinical and bacteriological efficacy of imipenem/cilastatin (IPM/CS) was evaluated in 30 cases of serious infections associated with hematological malignancies. 1. Among 28 evaluable cases, excellent efficacy was obtained in 6 cases and good effectiveness in 10 cases, resulting in a high clinical efficacy rate (57.1%). The clinical effectiveness of IPM/CS was not dependent on neutrophil count in peripheral blood. A 53.8% efficacy rate was observed in 26 cases which had received pretreatment with other antibiotics. 2. Antibacterial activities of IPM/CS have so far been evaluated against organisms isolated in 20 of 28 cases: 2 strains of coagulase-negative Staphylococcus, 2 strains of methicillin-resistant Staphylococcus aureus, 2 strains of Enterococcus faecalis, 9 strains of Enterobacter cloacae, and 8 other strains. 3. Among 3 evaluable cases treated with IPM/CS alone, response was good in 1 case. Among 25 patients receiving IPM/CS in combination with an aminoglycoside or a penicillin, the efficacy rate was 60%. 4. Five patients had IPM/CS-related adverse events; nausea and vomiting in 2 cases, seizures in 1 case, small increases in GOT and GPT in 2 cases, and the appearance of casts in urine sediment in 1 case. These patients, however, tolerated the complete course of therapy with IPM/CS except the 2 cases with nausea and vomiting. These results indicate that chemotherapy with IPM/CS is effective for the treatment of severe infectious diseases accompanied by hematological disorders.

Adolescent↗
PubMed1992

Stimulation of phosphoinositol turnover and protein kinase C activation by granulocyte-macrophage colony-stimulating factor in HL-60 cells.

Phosphoinositol turnover, diacylglycerol generation, protein kinase C (PK-C) activity, and intracellular cyclic nucleotides were studied in an established human leukemia cell line, HL-60, in response to one of the hematopoietic cytokines, granulocyte-macrophage colony-stimulating factor (GM-CSF). Continuous exposure of HL-60 cells to GM-CSF induced the cell differentiation that was evaluated by the nitroblue tetrazolium (NBT) reducing activity. GM-CSF also exhibited a proliferative effect on HL-60 cells. GM-CSF at 1 nmol/L, an optimal concentration for cell growth and cell differentiation, induced significant changes in the intracellular inositoltriphosphate (IP3). Diacylglycerol generation was also stimulated by GM-CSF treatment. GM-CSF increased the membrane PK-C activity by 10-fold of the control, whereas no measurable change in cyclic nucleotides was observed. These data indicated that phosphoinositol turnover and the activation of PK-C were included in the GM-CSF signal transducing pathway in HL-60 cell. Phosphoinositol response leading to PK-C activation may act as a trigger signal of cell differentiation by GM-CSF.

Cell Differentiation↗
PubMed1992

Expression of high affinity binding sites for erythropoietin on L8057 cells, a mouse megakaryoblastic cell line, associated with cell differentiation.

In this study, specific binding sites were examined for erythropoietin (EPO) on the mouse leukemic cell line, L8057. This cell line is megakaryoblastic in origin as evidenced by an enlargement of cell size, multinuclearity, intense activity of acetylcholinesterase, more expression of glycoprotein IIb and IIIa antigen, and higher ploidy distribution after the treatment with 12-o-tetradecanoylphorbor-13-acetate (TPA). The original undifferentiated cells possessed a single class of low affinity binding sites for recombinant human (rh) EPO with a Kd of 3.5 nM. Following the treatment with TPA, high affinity binding sites (Kd; 440 pM) were expressed in addition to the low affinity sites. EPO stimulated the incorporation of 3H-leucine into TPA-treated L8057 cells, and the maximal effect of EPO was observed at the same order as the Kd value of high affinity sites. The present data demonstrates that the expression of high affinity binding sites for EPO is associated with the differentiation of L8057 cells which have megakaryocytic characteristics. Furthermore, protein synthesis stimulated by EPO may be mediated through the high affinity sites.

Acetylcholinesterase↗
PubMed1992

Effects of tolbutamide on fructose-2,6-bisphosphate formation and ketogenesis in hepatocytes from diabetic rats.

To assess the extrapancreatic action of sulfonylurea directly in the diabetic, effects of tolbutamide on hepatocyte fructose-2,6-bisphosphate (F-2,6-P2) formation and ketone production were investigated using isolated hepatocytes from streptozotocin (STZ)-induced diabetic rats. The basal level of hepatocyte F-2,6-P2 was significantly higher in diabetic rats within 2 weeks after STZ (40 mg/kg body weight) injection compared with that in the nondiabetic control group. Ultimately, a marked decrease in the F-2,6-P2 level was observed at 4 weeks after STZ administration (10% of the control). Although the addition of tolbutamide further increased the hepatocyte F-2,6-P2 level during the first week after STZ injection, no significant effect was observed after the second week and on from the initial STZ. Treatment of diabetes with insulin restored the stimulatory effect of tolbutamide on the hepatocyte F-2,6-P2 formation. Tolbutamide, independently of insulin treatment, lowered the ketone production of hepatocytes from diabetic rats. The present results indicate that insulin is necessary, in advance, for sulfonylurea to stimulate the liver F-2,6-P2 formation, while tolbutamide inhibition of hepatocyte ketone production is independent of insulin. These results provide further support for the role of sulfonylurea in regulating hepatic energy metabolism in the diabetic.

3-Hydroxybutyric Acid↗
PubMed1992

Neuropeptide Y inhibits beta-adrenergic agonist- and vasoactive intestinal peptide-induced cyclic AMP accumulation in rat pinealocytes through pertussis toxin-sensitive G protein.

The effects of neuropeptide Y (NPY) on pineal gland cyclic AMP (cAMP) accumulation were investigated using dispersed pinealocytes from rats. NPY inhibited the intracellular cAMP accumulation stimulated by isoproterenol and norepinephrine in a dose-dependent manner during a 10-min incubation of pinealocytes. NPY (1 x 10(-7) M) also inhibited vasoactive intestinal peptide (VIP)- and cholera toxin-induced cAMP accumulation. The inhibitory effect of NPY on isoproterenol-induced cAMP accumulation was completely abolished by a 5-h pretreatment of pinealocytes with 1 microgram/ml of pertussis toxin (PT). These results suggest that NPY participates in modulation of cAMP production in the rat pineal gland through PT-sensitive G protein. Yohimbine, an alpha 2-adrenergic antagonist, blocked NPY inhibition of isoproterenol-stimulated cAMP accumulation. On the other hand, the alpha 2-adrenergic agonist clonidine by itself did not affect cAMP accumulation stimulated by isoproterenol but significantly potentiated NPY action. The present study demonstrates that NPY inhibits beta-adrenergic or VIPergic stimulation of the pineal gland cAMP accumulation. The inhibitory effect of NPY is mediated through PT-sensitive G protein. Our results also suggest that NPY exerts its action to affect alpha 2-adrenoceptor function.

Adrenergic beta-Agonists↗
PubMed1992

Myelofibrosis and systemic lupus erythematosus: reversal of fibrosis with high-dose corticosteroid therapy.

A case of myelofibrosis in association with systemic lupus erythematosus (SLE) is reported. Acute thrombocytopenia and a bleeding tendency developed in a 24-year-old woman with SLE. Bone marrow aspiration was unsuccessful due to myelofibrosis. Pulse therapy with methylprednisolone reversed both thrombocytopenia and myelofibrosis. A review of the literature revealed that the coexistence of SLE and myelofibrosis is a rare occurrence. Only 7 cases, to our knowledge, have ever been reported in detail. The present case is the 3rd in which myelofibrosis was reversed by corticosteroids.

Adult↗
PubMed1992

Phase I/II study of recombinant human granulocyte-macrophage colony-stimulating factor in patients with advanced malignancy. The Multicenter Study Group.

The toxicity and hematologic effects of Escherichia coli-derived recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) were studied in 58 treatment cycles in Japanese patients with advanced malignancy as a phase I/II clinical trial. rhGM-CSF in doses from 30 to 250 micrograms/m2/day was administered by 24-hour continuous intravenous infusion, 8-hour intravenous, or a daily subcutaneous injection for 14 days. The most common adverse drug events (ADE) were fever, nausea/vomiting, diarrhea, skin eruption, and phlebitis. The frequency of moderate and severe ADE was 2.9, 14.7, 35.3 and 47.1% at 30, 60, 125, 250 micrograms/m2/day, respectively. In terms of administration routes, the frequency of ADE was 69% with 24-hour continuous intravenous infusion, 39.1% with 8-hour intravenous infusion and 16.7% with subcutaneous injection. Regarding the hematologic effects of rhGM-CSF, leukopenia improved in a dose-dependent manner. The appropriate dose level to be used in the phase II study was estimated to be in the range between 60 and 250 micrograms/m2/day.

Adult↗