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K Asahi

Publications and source records attributed to K Asahi.

At least 37 records · Page 2Linked to original sources
PubMed1999

A sensitive and specific ELISA for plasma pentosidine.

BACKGROUND: Advanced glycation end products are formed by non-enzymatic glycation and oxidation reaction. Pentosidine is a well-known and characterized structure among them, and has been implicated in the pathogenesis of complications associated with chronic renal failure and long-term dialysis, such as dialysis-related amyloidosis and atherosclerosis. METHODS: We established a highly sensitive and specific competitive enzyme-linked immunosorbent assay (ELISA) for plasma pentosidine and applied it to large numbers of plasma samples including haemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) patients. We compared their plasma pentosidine levels determined by the competitive ELISA with those determined by high-performance liquid chromatographic (HPLC) assay currently used. RESULTS: The plasma pentosidine levels determined by the ELISA were correlated well with those determined by sophisticated instrumental HPLC assay, both in non-diabetic and diabetic dialysis patients. Both analyses yielded comparable results, with over 8-fold higher plasma pentosidine levels in HD and CAPD patients, irrespective of the presence or absence of diabetes, as compared to normal subjects and non-uraemic diabetic patients. CONCLUSIONS: The competitive ELISA will provide a rapid and convenient determination of plasma pentosidine content and thus be useful to assess the carbonyl stress in uraemic patients.

Adult↗
PubMed1999

Effects of tissue type plasminogen activator in embolic versus mechanical models of focal cerebral ischemia in rats.

Tissue type plasminogen activator (tPA) can be effective therapy for embolic stroke by restoring cerebral perfusion. However, a recent experimental study showed that tPA increased infarct size in a mouse model of transient focal ischemia, suggesting a possible adverse effect of tPA on ischemic tissue per se. In this report, the effects of tPA in two rat models of cerebral ischemia were compared. In experiment 1, rats were subjected to focal ischemia via injection of autologous clots into the middle cerebral artery territory. Two hours after clot injection, rats were treated with 10 mg/kg tPA or normal saline. Perfusion-sensitive computed tomography scanning showed that tPA restored cerebral perfusion in this thromboembolic model. Treatment with tPA significantly reduced ischemic lesion volumes measured at 24 hours by >60%. In experiment 2, three groups of rats were subjected to focal ischemia via a mechanical approach in which a silicon-coated filament was used intraluminally to occlude the origin of the middle cerebral artery. In two groups, the filament was withdrawn after 2 hours to allow for reperfusion, and then rats were randomly treated with 10 mg/kg tPA or normal saline. In the third group, rats were not treated and the filament was not withdrawn so that permanent focal ischemia was present. In this experiment, tPA did not significantly alter lesion volumes after 2 hours of transient focal ischemia. In contrast, permanent ischemia significantly increased lesion volumes by 55% compared with transient ischemia. These results indicate that in these rat models of focal cerebral ischemia, tPA did not have detectable negative effects. Other potentially negative effects of tPA may be dependent on choice of animal species and model systems.

Animals↗
PubMed1998

Generation of protein carbonyls by glycoxidation and lipoxidation reactions with autoxidation products of ascorbic acid and polyunsaturated fatty acids.

Accumulation of carbonyl derivatives of proteins (protein carbonyl) is taken as a biomarker of oxidative protein damage in aging and in various diseases. We detected protein carbonyls in situ in human diabetic arteriosclerotic tissues and characterized the formation of protein carbonyls. Protein carbonyls were identified in the thickened intima of arterial walls and co-localized with protein adducts formed by carbonyl amine chemistry between protein and carbonyl compounds derived from autoxidation of carbohydrates, lipids, and ascorbate, i.e. advanced glycation end products or glycoxidation products, such as carboxymethyllysine (CML) and pentosidine, and lipoxidation products, such as malondialdehyde (MDA) and 4-hydroxy-nonenal (HNE). In vitro incubation of proteins with ascorbic acid accelerated the production of protein carbonyls as well as CML and pentosidine, and incubation with arachidonate accelerated the production of protein carbonyls as well as CML, MDA, and HNE. By contrast, incubation of proteins with glucose resulted in the production of CML and pentosidine, but not protein carbonyls. Schiff base inhibitors, (+/-)-2-isopropylidenehydrazono-4-oxo-thiazolidin-5-ylace tanilide and aminoguanidine, inhibited the production of protein carbonyls after incubation with ascorbate and arachidonate. The present study suggests that ascorbate and polyunsaturated fatty acids, but not glucose, represent potential sources of protein carbonyls, and that both the glycoxidation and lipoxidation reactions contribute to protein carbonyl formation in aging and various diseases.

Arachidonic Acid↗
PubMed1998

Increased cutaneous immunoreactive stem cell factor expression and serum stem cell factor level in systemic scleroderma.

Skin hyperpigmentation and itching are characteristic findings in systemic sclerosis (SSC) patients. Stem cell factor (SCF, c-kit ligand) is a multifunctional cytokine which can promote melanocyte and mast cell development. We investigated the SCF expression histopathologically in normal and SSC skin, and compared the expression with the serum SCF levels measured with a specific enzyme-linked immunosorbent assay. The epidermal and dermal immunoreactive SCF expression was markedly higher in the forearm skin of edematous phase SSC patients than in that of normal subjects. Tissue SCF expression declined from the sclerotic phase to the atrophic phase, where it was close to the normal level. In contrast, the elevated serum SCF level seen in the edematous phase samples was further increased in the sclerotic phase samples. The serum SCF level decreased in the atrophic phase, but it still remained at a level higher than that of the normal controls. Itching and increase of dermal mast cell number are characteristic of edematous phase SSC, and are in bears a parallel to the presently observed dermal SCF expression profile. Pigmentation is significant in sclerotic phase SSC and lasts to the atrophic phase, which may correspond to the serum SCF level observed here. These results indicate a contribution of the fibroblast membrane integral SCF in dermal mast cell development, and of the soluble serum SCF to melanocyte activation in SSC.

Adult↗
PubMed1997

Differanisole A, a novel antitumor antibiotic, enhances growth inhibition and differentiation of human myeloid leukemia cells induced by 9-cis retinoic acid.

Differanisole A, 3,5-dichloro-2-hydroxy-4-methoxy-6-n-propylbenzoic acid, inhibited growth of human myeloid leukemia cells. The compound induced G1 arrest and granulocytic differentiation of HL-60 cells, although the differentiation-inducing effect was modest. Differanisole A and 9-cis retinoic acid (9cisRA) synergistically inhibited the growth and induced functional and morphologic differentiation of HL-60 and NB4 cells, whereas the combined treatment with differanisole A and all-trans retinoic acid or 1alpha,25-dihydroxyvitamin D3 was less effective. Similar results were obtained in primary culture of leukemia cells from a patient with acute promyelocytic leukemia. The synergistic effect on growth inhibition and induction of differentiation required simultaneous treatment with differanisole A and 9cisRA. Differanisole A and an RXR-specific ligand (Ro47-5944) cooperatively inhibited the cell growth, while the combined effect of differanisole A and an RAR-specific ligand Am80 was just additive. Differanisole A in combination with 9cisRA may have implications for therapy of acute promyelocytic leukemia patients.

Alitretinoin↗
PubMed1997

Cotylenin A, a plant-growth regulator, induces the differentiation in murine and human myeloid leukemia cells.

Protein factors playing a significant part in differentiation and development have been recently elucidated. However, low molecular factors which also seem to be essential remain still unknown, although only retinoic acid has become such a candidate. Cotylenins had been isolated as the plant-growth regulators, and have been found to affect a number of physiological processes of higher plants. Here we report that at the concentrations above 12.5 microg/ml (20 microM) cotylenin A induced the functional and morphological differentiation in murine (M1) and human myeloid leukemia (HL-60) cells. Although cotylenin A has some similarity to PMA both in carbotricyclic diterpene structure and in biological activity (i.e. differentiation-induction of HL-60 cells into macrophages), the activation of PKC and the elevation of Ca2+-levels by cotylenin A were not observed. Quite recently it has been reported that fusicoccin (closely related to cotylenin A)-targets are 14-3-3 proteins, which are at the crosspoint of a huge array of signalling and regulatory pathways. These results suggest that cotylenin A might become a useful tool for the elucidation of molecular mechanisms of differentiation and development.

Animals↗
PubMed1995

DIF-1, morphogen of Dictyostelium discoideum, induces the erythroid differentiation in murine and human leukemia cells.

The structure of morphogen of Dictyostelium discoideum, DIF-1, which was elucidated by Morris et al. proved to be closely similar to that of differanisole A which had been isolated by us from the metabolites of a simple eucaryote, Chaetomium, as the differentiation-inducer of murine and human undifferentiated tumor cells. This fact seemed to suggest the molecular structure playing an important part in differentiation and development beyond species. We have already examined whether differanisole A induces the differentiation in Dictyostelium discoideum, and it was morphologically and biochemically confirmed. In this study, we examined whether DIF-1 induces the differentiation in murine and human leukemia cells. Above the concentration of 2 micrograms/ml (6.5 microM), DIF-1 induced the differentiation in murine erythroleukemia B8 cells and in human leukemia K562 cells into the hemoglobin-synthesizing erythrocyte-like cells.

Animals↗
PubMed1995

Pathogenic role of asialo human chorionic gonadotropin in gestational thyrotoxicosis.

We reported that gestational thyrotoxicosis is induced by thyroid-stimulating activity (TSA) of circulating hCG. However, the serum immunological hCG concentration did not correlate to TSA. To elucidate this, we examined the relation of carbohydrate moieties of hCG to bioactivity in 79 early pregnant women, divided into 4 groups: no emesis, mild emesis, hyperemesis, and gestational thyrotoxicosis with hyperemesis. Serum free T4 (FT4) and free T3 (FT3) levels were significantly higher and TSH was lower in the hyperemesis (FT4, 23.42 +/- 5.02 pmol/L; FT3, 6.26 +/- 1.80 pmol/L; TSH, 0.30 +/- 0.44 mU/L) and in gestational thyrotoxicosis (FT4, 48.65 +/- 14.80 pmol/L; FT3, 14.71 +/- 3.47 pmol/L; TSH, < 0.04 mU/L) groups than in the no emesis group (FT4, 16.99 +/- 2.48 pmol/L; FT3, 5.51 +/- 0.75 pmol/L; TSH, 1.37 +/- 1.23 mU/L; P < 0.0005). TSA was also significantly higher in the hyperemesis (566 +/- 187%) and gestational thyrotoxicosis (832 +/- 168%) groups than in the no emesis group (321 +/- 135%). We found no significant difference among serum hCG concentrations measured by immunoassay in the four groups. To characterize the carbohydrate chains, serum hCG was fractionated by Concanavalin-A and ricin lectin affinity chromatography. The fraction firmly bound to Con-canavalin-A, which contains hCG with high mannose and hybrid-type carbohydrate chains, was significantly higher in the hyperemesis group (91.07 +/- 2.06%; n = 15) than in the no emesis group (89.61 +/- 2.38%; n = 24; P < 0.04). The fraction firmly bound to ricin column, which contains hCG with asialo-carbohydrate chains, was significantly increased in the gestational thyrotoxicosis group (3.44 +/- 1.70%; n = 5) compared with that in the no emesis group (1.77 +/- 0.49%; n = 24; P < 0.03). Serum FT4 positively correlated to the hCG fraction firmly bound to ricin column (r = 0.61; P < 0.001). We conclude that thyrotoxicosis with hyperemesis may be caused by circulating asialo-hCG with higher thyrotropic bioactivity.

Adult↗
PubMed1995

Significance of thyroid stimulating antibody and long term follow up in patients with euthyroid Graves' disease.

We examined 13 patients with euthyroid Graves' disease suspected ophthalmologically, by comparing them with 20 patients with untreated Graves' disease and by following them up for 5 to 10 years. They had Graves' ophthalmopathy (NOSPECS class II-IV) without other ocular diseases, normal levels of serum thyroid hormones, and no previous history of Graves' disease. Proptosis in euthyroid Graves' disease was not significantly different from that in untreated Graves' disease. In 3 patients with euthyroid Graves' disease, TSH was suppressed. There was either no TSH response to TRH or it was low in 7 of 12 patients examined. The result of a T3-suppression test was abnormal in 8 of 11 patients examined. Titers of serum TGHA, MCHA, TSH-binding inhibitory immunoglobulin (TBII), and thyroid stimulating antibody (TSAb) were significantly lower in patients with euthyroid Graves' disease compared than in patients with untreated Graves' disease. TSAb, however, was positive in 12 of 13 (92%) patients. In spite of positive TSAb, 9 of 13 patients with euthyroid Graves' disease had normal radioactive iodine uptake (RAIU). During the observation period, various abnormalities in thyroid function developed: persistent hyperthyroidism in 5 patients (38%), transient thyrotoxicosis in 2 (15%) and transient hypothyroidism in 1 (8%). We conclude that euthyroid Graves' disease is a subtype of Graves' disease that minimally develops thyrotoxicosis in spite of the existence of TSAb due to some mechanism inhibiting thyroid growth or stimulation, and that the measurement of TSAb provides a useful marker for the diagnosis of this disease.

Adult↗
PubMed1994

Direct evidence for erythropoietin-induced release of endothelin from peripheral vascular tissue.

The effect of recombinant human erythropoietin (r-HuEPO, 0.1 to 2.0 U/ml) on endothelin-1 (ET-1) release was examined in isolated hind legs perfused with Krebs-Ringer solution from normal rats. r-HuEPO increased immunoreactive (ir-) ET-1 release in a dose-dependent fashion; the maximal percent increment in ir-ET-1 release evoked by r-HuEPO (2.0 U/ml) was about +210% over the basal rate of release. However, r-HuEPO showed no effect on release of angiotensin II, thromboxane B2 or vasodilatory prostaglandin I2 from the vasculature. These results not only provide direct evidence that r-HuEPO has the potential to specifically stimulate release of ET-1 from peripheral vascular beds, but, hence, suggest a contributory role of ET-1 in r-HuEPO-induced hypertension in anemic human subjects undergoing r-HuEPO therapy.

6-Ketoprostaglandin F1 alpha↗
PubMed1994

Identification of causative chemicals of allergic contact dermatitis using a combination of patch testing in patients and chemical analysis. Application to cases from rubber gloves.

5 cases of allergic contact dermatitis from rubber gloves were investigated by our recommended procedures using a combination of patch testing in patients and chemical analysis of causative rubber products by gas chromatography (GC) and high-performance liquid chromatography (HPLC). We previously confirmed that zinc ethylphenyldithiocarbamate (ZEPC), a dithiocarbamae-type accelerator (DTC), was causative in a case of allergic contact dermatitis from rubber work gloves. Subsequently, we have clarified that DTCs such as zinc dimethyldithiocarbamate (ZDMC), zinc diethyldithiocarbamate (ZDEC) and zinc dibutyldithiocarbamate (ZDBC) and amines such as dimethylamine (DMA), diethylamine (DEA) and piperidine (PIP) were also causative in cases from surgical rubber gloves. Thus, our investigative studies revealed that, although thiurams have been taken much more notice of as allergenic compounds than their corresponding DTCs and amines, not only DTCs such as ZDMC, ZDEC, ZDBC and ZEPC, but also amines such as DMA, DEA and PIP were noteworthy causative candidates of allergic contact dermatitis from rubber gloves.

Adult↗
PubMed1993

Differanisole A, an inducer of the differentiation of Friend leukemic cells, induces stalk cell differentiation in Dictyostelium discoideum.

Differanisole A isolated from the conditioned medium of a soil microorganism, Chaetomium strain RB-001, is an inducer of the differentiation of the Friend leukemic cells (mouse leukemia cells). The chemical structure of this substance is very similar to that of stalk cell differentiation-inducing factor (DIF) isolated from the cellular slime mould, Dictyostelium discoideum. We examined the effects of differanisole A on Dictyostelium HM44 cells, a mutant strain which is defective in DIF production, and found this substance to be an inducer of stalk cell differentiation in D. discoideum.

Animals↗
PubMed1993

Crucial role of serum human chorionic gonadotropin for the aggravation of thyrotoxicosis in early pregnancy in Graves' disease.

Thyrotoxicosis in Graves' disease is often aggravated in early pregnancy and is closely associated with postpartum recurrence of stimulative thyrotoxicosis. To examine whether thyroid-stimulating TSH receptor antibody (TSAb) or human chorionic gonadotropin (hCG), which also has thyroid-stimulating activity (TSA), was responsible for this early aggravation, the respective TSA due to TSAb or hCG was evaluated by a highly sensitive cAMP accumulation assay using FRTL-5 cells. TSA was detectable in all of 11 women in normal early pregnancy, correlated positively with serum hCG concentration, and was abolished completely by the pretreatment of serum sample with the solid-phase hCG antibody coupled with Sepharose 4B. The model serum samples of Graves' disease with pregnancy were made by the mixture of normal pregnant and Graves' sera, and their TSA were reduced by the pretreatment with the solid-phase hCG antibody, just corresponding with the reduction in hCG-induced TSA. TSA of early pregnant sera in 20 patients with Graves' disease decreased significantly but were still positive even after the pretreatment with the hCG antibody. Serial changes in TSAb and hCG-induced TSA were measured in 5 of these 20 pregnant patients. hCG-induced TSA increased associated with the increase in free thyroxine, while TSAb did not show striking change in early pregnancy. These data indicate that (1) respective TSA due to TSAb or hCG can be measured distinctively by using the solid-phase hCG antibody and (2) hCG plays a crucial role in the aggravation of Graves' thyrotoxicosis in early pregnancy.

Autoantibodies↗
PubMed1993

Endogenous event-related potentials in obsessive character.

Fifteen healthy subjects with obsessive character (OC) and 15 control subjects were tested for endogenous event-related potentials using the auditory odd ball paradigm. A difference was found in the peak amplitude of the P200 component in response to both stimuli; the subjects with OC had smaller amplitudes than the controls, and the mean amplitude for the 120 to 200 ms latency range was smaller (negative shift) for the OC subjects. In the OC subjects, NA appears to be markedly induced to both rare and frequent stimuli; moreover, the OC subjects may show excessive reactions to selective attention as well as to the process of pattern recognition.

Acoustic Stimulation↗
PubMed1993

Contact sensitivity and cross-reactivity of budesonide.

5 cases of allergic contact dermatitis due to budesonide are described. We studied the antigen determinant structures in these cases by applying patch tests with several substances related to budesonide. 2 cases showed cross-reactions to both amcinonide and prednisolone acetate. The antigen determinant structure is also discussed.

Adult↗
PubMed1993

[A long-term hemodialysis patient complicated with systemic calciphylaxis].

A 46-year-old male patient underwent long-term hemodialysis treatment had suffered from calciphylaxis (defined by Selye), such symptoms as advanced systemic vascular calcification, rapid progression of gangrene on both fingers and toes, disturbance of consciousness, and sclerosis and obstruction of the superficial vein after venipuncture during 11.5 years of dialysis. Furthermore, he had a long history (30 years) of heavy smoking. He died as a result of sepsis due to pneumonia after 12.5 years of dialysis. He had received dialysis treatment using a small amount of dialysate (50 liters on a recirculating system) for 8.5 years and had been dialysed 2 and 2 or 3 times a week for 10 years. As a result of this insufficient dialysis treatment, his characteristic laboratory data showed hypocalcemia, hyperphosphatemia, elevated calcium-phosphorus product, advanced metabolic acidosis, hyperalkaliphosphatemia and elevated serum parathyroid hormone. Autopsy revealed the following: 1) enlargement parathyroid gland enlarged in two (4.0 g and 2.0 g, respectively) showing adenomatous hyperplasia presenting cord-like arrangement of chief cells and water-clear cells, 2) systemic medial calcification in radial, ulnar, renal, mesenteric and brain arteries, and 3) Berline-blue positive iron deposit in calcified arteries in mesenteric and parathyroid tissue. From these results, we concluded that factors (challengers) related to the appearance of calciphylaxis might be as follows: 1) advanced secondary hyperparathyroidism, 2) long-term uremic state, 3) administration of VD2 and VD3, 4) iron salt injection, and 5) a long history of heavy smoking. We speculated that these challengers might act synergistically to cause calciphylaxis.

Calciphylaxis↗