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Biomedical subjects

H Kume

Publications and source records attributed to H Kume.

At least 37 records · Page 2Linked to original sources

Possible involvement of Rho kinase in Ca2+ sensitization and mobilization by MCh in tracheal smooth muscle.

We examined the effects of Rho kinase on contraction and intracellular Ca2+ concentration ([Ca2+](i)) in guinea pig trachealis by measuring isometric force and the fura 2 signal [340- to 380-nm fluorescence ratio (F340/F380)]. A Rho kinase inhibitor, Y-27632 (1-1,000 microM), inhibited methacholine (MCh)-induced contraction, with a reduction in F340/F380 in a concentration-dependent manner. The values of EC(50) for contraction and F340/F380 induced by 1 microM MCh with Y-27632 were 27.3 +/- 5.1 and 524.1 +/- 31.0 microM, respectively. With 0.1 microM MCh, the values for these parameters were decreased to 1.0 +/- 0.1 and 98.2 +/- 6.2 microM, respectively. Tension-F340/F380 curves for MCh indicated that Y-27632 caused an ~50% inhibition of MCh-induced contraction, without a reduction in F340/F380. These effects of Y-27632 were not inhibited by a protein kinase C inhibitor, GF-109203X. Our results indicate that inhibition of Rho kinase attenuates both Ca2+ sensitization and [Ca2+](i).

Amides↗

Role of lysophosphatidylcholine in the desensitization of beta-adrenergic receptors by Ca(2+) sensitization in tracheal smooth muscle.

Lysophosphatidylcholine (Lyso-PC) is generally considered to promote tissue inflammation. To determine the involvement of exogenous Lyso-PC in the beta-adrenergic desensitization by phospholipase A2, we examined the inhibitory effects of isoproterenol (ISO) on tension and intracellular Ca(2+) concentration by methacholine (MCh) after continuous exposure to Lyso-PC in guinea-pig tracheal smooth muscle, using isometric tension recordings and fura-2 signal (F340/F380 ratio). Pre- exposure to 10 microM Lyso-PC markedly reduced subsequent inhibition by 0.3 microM ISO against 1 microM MCh-induced contraction in a time-dependent manner. In contrast, values of percent F340/F380 ratio for MCh with ISO were not affected after exposure to Lyso-PC. In the presence of Y-27632, a selective rho-kinase inhibitor, a reduction in subsequent relaxation by ISO after exposure to Lyso-PC was inhibited in a concentration-dependent manner. Preincubation with cholera toxin also inhibited reduced responsiveness to ISO by Lyso-PC. Pre-exposure to Lyso-PC did not attenuate subsequent relaxation by agents that bypass beta-adrenergic receptors. These results indicate that continuous exposure to Lyso-PC may cause homologous desensitization of beta-adrenergic receptors via an augmentation in sensitivity to Ca(2+) by rho, a small G protein, in airway smooth muscle, and that activation of the stimulatory G protein of adenylyl cyclase, G(s), may prevent this phenomenon.

Adenylate Cyclase Toxin↗

Effect of prolonged low-dose methylprednisolone therapy in acute exacerbation of idiopathic pulmonary fibrosis.

We report on a 74-year-old man with an acute exacerbation of idiopathic pulmonary fibrosis (IPF) who was successfully treated with prolonged low-dose methylprednisolone, initiated at a loading dose of 2 mg/kg, followed by 2 mg/kg per day for 14 days. The dose was then tapered. The exacerbation observed on the chest radiograph and high-resolution computed tomography was found to have abated after the treatment. This successful case suggests the feasibility of this methylprednisolone treatment protocol for patients with IPF accompanied by accelerated deterioration. Furthermore, this case suggests possible similarities between acute exacerbation of IPF and late acute respiratory distress syndrome, as the same treatment protocol was previously proved to be beneficial for patients with late acute respiratory distress syndrome.

Acute Disease↗

[Aortitis syndrome associated with ulcerative colitis, preceded by pulmonary infarction involvement].

A 21-year-old woman with a 6-year history of ulcerative colitis admitted to our hospital with chest pain, cough and fever of unknown origin in August 1998. On admission, laboratory data showed positive inflammatory signs. A chest radiograph and chest computed tomogram (CT) revealed nodular shadows in the right upper lung field. Fifty days after admission, hypertension developed and a bruit was audible in the neck and the upper abdomen. Digital subtraction angiography showed stenosis in carotid, renal and right upper pulmonary arteries. On the basis of these results, a diagnosis of aortitis syndrome was made. Moreover, these findings indicated pulmonary infarction in the right upper lobe due to aortitis syndrome. Aortitis syndrome preceded by pulmonary infarction involvement is very rare. Autoimmune disorders may have been involved in this case because of the association with ulcerative colitis.

Adult↗

Intradermal application of nociceptin increases vascular permeability in rats: the possible involvement of histamine release from mast cells.

Intradermal application of nociceptin was used to investigate its in vivo effect on the inflammatory response in rats. Intradermal nociceptin (5 pmol/site-5 nmol/site) increased vascular permeability in a dose-dependent manner. The increased vascular permeability by nociceptin (5 nmol/site) was dose-dependently inhibited by the histamine H1 receptor antagonist pyrilamine (50 pmol/site-5 nmol/site). In rat peritoneal mast-cell preparation, nociceptin (10(-8)-10(-4) M) dose-dependently stimulated histamine release. The effect of nociceptin (10(-5) M) occurred rapidly (within 30 s) and was inhibited by pertussis toxin, Ca2+, but was not sensitive to naloxone, a classical opioid receptor antagonist. These characteristics are in agreement with features of the opioid-receptor-like 1 (ORL1) receptor, a non-classical opioid receptor linked to a pertussis toxin-sensitive G protein. Taken together, these data suggest that nociceptin, likely acting via the ORL1 receptor at the site of inflammation, might be critical for the enhancement of the inflammatory response by stimulating histamine release from mast cells.

Administration, Cutaneous↗

Imipramine inhibits Cl(-) secretion by desensitization of beta-adrenergic receptors in calu-3 human airway cells.

Recent investigations have found that tetracyclic antidepressants like imipramine (IMP) have high-affinity sites not only in brain but also in mammalian lung. In the present study, we examined the effects of IMP on the Cl(-) secretion produced by isoproterenol (ISP), a beta-adrenergic receptor (beta-AR) agonist, in Calu-3 human airway cells. ISP applied in the basolateral solution generated a sustained short-circuit current that was abolished by diphenylamine-2-carboxylate, a Cl(-) channel blocker. IMP (0.01-1 mM) applied in the apical or basolateral solution for 30 min significantly inhibited the ISP-induced responses in a concentration-dependent manner, and the inhibitory effects of this drug were remarkable when applied from the apical rather than the basolateral side. ISP-induced responses were mimicked by forskolin- and 8-bromo-cyclic AMP-induced ones, but which were insensitive to IMP. These results indicate that IMP desensitizes the beta-AR on the basolateral membrane from the cytosolic side in Calu-3 cells.

Adrenergic Uptake Inhibitors↗

CFTR-Mediated anion conductance regulates Na(+)-K(+)-pump activity in Calu-3 human airway cells.

We studied the role of CFTR in the Na(+)-K(+)-pump activity of Calu-3 human airway cells. To estimate the Na(+)-K(+)-pump activity on the basolateral membrane, the ouabain-sensitive component of the short-circuit current (Isc) was measured after permeabilization of the apical membrane with nystatin, a Na(+) ionophore. The Na(+)-K(+)-pump activity was diminished by a selective CFTR blocker (glybenclamide) or nonspecific Cl(-) channel inhibitors (NPPB and DPC) but not by outwardly rectifying Cl(-) channel blockers (DNDS, DIDS). Augmentation of anion conductance by 8-bromo-cyclic AMP (8Br-cAMP, 1 mM) potentiated the Na(+)-K(+)-pump activity that was reduced by blocking CFTR or by the replacement of Cl(-) with gluconate, a less membrane-permeant anion. The Na(+)-K(+)-pump activity was unaffected by the replacement of Cl(-) with NO(-)(3) that has equal permeability through the CFTR. These results suggest that the anion movement through the CFTR may contribute to the Na(+)-K(+)-pump activity in Calu-3 cells by regulating the rate of Na(+) entry.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗

Benzo[a]pyrene carcinogenicity is lost in mice lacking the aryl hydrocarbon receptor.

The contribution of the aryl hydrocarbon receptor (AhR) in induction of a battery of xenobiotic-metabolizing enzymes has been studied extensively. However, no direct proof has been obtained that it plays a role in modulating carcinogenesis. To address the question of whether AhR is required for tumor induction, we have investigated the response of AhR-deficient mice to benzo[a]pyrene (B[a]P), a widely distributed environmental carcinogen. B[a]P treatment induced expression of the cytochrome P450 gene Cyp1a1 in the skin and liver of AhR-positive mice bearing +/+ and +/- genotypes and did not induce expression of the cytochrome P450 gene Cyp1a1 in AhR-null mice in either skin or liver. In contrast, Cyp1a2 gene expression was positive in liver irrespective of the presence or absence of the AhR gene, or B[a]P treatment, although its inducibility was lost in the AhR(-/-) mouse. All AhR-positive male mice of both +/+ and +/- genotypes that received subcutaneous injection of B[a]P (2 mg) on the first and the eighth days had developed subcutaneous tumors at the site of injection at the end of the 18-week experiment. In contrast, no tumors were apparent in any of the AhR-deficient mice. Likewise, topical application of B[a]P (200 microg) at weekly intervals to the skin of female mice for 25 weeks produced skin tumors only in the AhR-positive mice. Thus the carcinogenic action of B[a]P may be determined primarily by AhR, a transcriptional regulator of the gene for CYP1A1. The results of the present study provide direct evidence that AhR is involved in carcinogenesis.

Animals↗

Synthesis, subcellular localization and VP16 interaction of the herpes simplex virus type 2 UL46 gene product.

We developed a rabbit polyclonal antiserum reactive against a recombinant 6x His-UL46 fusion protein expressed in Escherichia coli, and using this antiserum identified the UL46 gene product of herpes simplex virus type 2 (HSV-2) to be phosphoproteins with apparent molecular masses of 82-, 84-, and 86-kDa in infected Vero cells. The UL46 protein was produced in the late phase of infection in a manner highly dependent on viral DNA synthesis, and was mainly distributed at the edge of the nucleus in the cytoplasm. Although its kinetics of production and its progress of distribution were different from those of the major tegument protein VP16 (the UL48 gene product or alpha-trans-inducing factor (alphaTIF)), most of the UL46 protein colocalized with VP16 in the late phase of infection, and copurified with it in column chromatography. Moreover, our data showed that the HSV-2 UL46 protein, when coexpressed with VP16, enhanced alpha4 promotor-regulated gene expression in a transient luciferase reporter assay, while the expression of the UL46 protein alone suppressed it.

Animals↗

Case report. A case of chromoblastomycosis effectively treated with terbinafine. Characteristics of chromoblastomycosis in the Kitasato region, Japan.

A 38-year-old male with history of trauma in the left gluteal region 20 years ago presented with a dark red skin eruption at the traumatized area. It gradually grew to form an erythematous plaque with a well-defined border. Clinical findings and mycological cultures resulted in the diagnosis of chromoblastomycosis due to Fonsecaea pedrosoi. After initial administration of 5-fluorocytosine and local heat an almost complete cure was achieved with terbinafine combined with local heat therapy. A review is given on the chromoblastomycosis cases observed in the Kitasato region in Japan.

Adult↗

Bifonazole (Mycospor cream) in the treatment of moccasin-type tinea pedis. Comparison between combination therapy of bifonazole cream + 10% urea ointment (Urepearl) and occlusive dressing therapy with the same agents.

Moccasin-type tinea pedis(MTTP) is a hardly curable superficial dermatomycosis primarily characterized by hyperkeratosis of the sole. In this study, we compared the usefulness of combination therapy of bifonazole (Mycospor cream) + 10% urea ointment (Urepearl) (overlapping application group = group I) with occlusive dressing therapy with the same agents (group II) in the treatment of MTTP, and obtained the following results. (1) The clinical improvement rate (percentage of "marked improvement" and "moderate improvement") was 60.4% in group I and 83.3% in group II. (2) The mycological eradication rate was 48.7% in group I and 82.1% in group II after 4 weeks of treatment and 90.9 and 96.9%, after 12 weeks of treatment, respectively. (3) The clinical utility rate (percentage of "very beneficial" and "beneficial") was 83.3% in group I and 93.8% in group II. These results indicate the superiority of both combination therapy of bifonazole + 10% urea ointment (overlapping application group) and occlusive dressing therapy with the same agents in terms of efficacy and safety for the treatment of MTTP, and suggest that they can be recommended for treatment of patients for whom it is difficult to use oral antimycotic agents or for patients who fail to respond to oral medications alone.

Administration, Topical↗

Genetic identification of bilateral primary or metastatic nonpapillary renal cell carcinoma.

OBJECTIVE: To clarify the clonality of bilateral tumours by genetic analysis of bilateral renal cell carcinomas (RCCs) using the VHL gene, which is inactivated in approximately 60% of RCCs and which plays a causal role in the development of most cases of nonpapillary RCC. PATIENTS AND METHODS: The study included 20 patients; seven had von Hippel-Lindau disease, three had papillary RCC and 10 had nonpapillary RCC. Paraffin-embedded blocks of tumour tissue were obtained from two of the three patients with papillary RCC and from nine of 10 with nonpapillary disease; all three exons of VHL were examined by direct sequencing. RESULTS: As reported previously, no VHL mutations were found in papillary tumours. However, in five of the nine nonpapillary cases, VHL mutations were identified in tumours on one or both sides. Three of the tumours had the same mutation on both sides, confirming a common origin. In the remaining two patients, the mutation status differed between the sides, confirming a bilateral primary origin. The former cases were characterized by a relatively large tumour on one side and multiple tumours on the other. CONCLUSIONS: In nonpapillary RCC multiplicity may suggest a metastatic origin. Such genetic information will be useful in treating and following patients with bilateral renal tumours.

Aged↗

Serum itraconazole and hydroxyitraconazole concentrations and interaction with digoxin in a case of chronic hypertrophic pachymenigitis caused by Aspergillus flavus.

A patient treated with itraconazole (ITCZ) under the diagnosis of Aspergillus flavus-induced chronic hypertrophic pachymeningitis is presented. The reason for the successful cure of this patient was investigated by the pharmacokinetic analysis of serum levels of ITCZ. Concurrently administered digoxin was also investigated for its drug-drug interaction. The patient (a 75-year-old male) developed ophthalmopathy, and was diagnosed as having A. flavus hypertrophic pachymeningitis by pachymeninx biopsy. After admission, he was treated with FLCZ, AMPH, 5-FC and MCZ. The infection tended to subside with the AMPH administration. Since renal insufficiency was induced by AMPH and the other antifungal drugs were ineffective, daily administration of 200 mg of ITCZ was initiated, and the inflammatory signs and symptoms gradually subsided. The symptoms did not recur during the 36 months of itraconazole treatment after discharge, and it was concluded that ITCZ was effective for A. flavus hypertrophic pachymeningitis. Pharmacokinetic parameters of ITCZ and OH-ITCZ as follows: ITCZ: Cmax 93.2 ng/ml, T1/2 beta 11 hours, AUC0-24 999 ng.h/ml, OH-ITCZ: Cmax 159.4 ng/ml, T1/2 beta 16. 2 hours, AUC0-24 of 1391 ng.h/ml. Both ITCZ and OH-ITCZ reached steady states seven days after administration began. The ITCZ and OH-ITCZ levels in serum collected 36 months after the initiation of administration were 452.9 ng/ml and 1233.6 ng/ml, respectively. Cmax and AUC0-24 of ITCZ and OH-ITCZ on the second day were markedly lower than those in healthy adults reported by Oguchi et al., and hypoalbuminemia observed at administration on that day was considered the most probable cause. It was assumed that the most plausible reason for a successful cure even at a low dose of ITCZ was the increase of distribution to tissue by the increase of the unbound form. Digoxin was concurrently given to this patient at 0. 125 mg/day, but the blood digoxin level was not elevated. Consideration of the blood level of albumin is believed to be important for evaluating the blood concentration of ITCZ.

Aged↗