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H Kume

Publications and source records attributed to H Kume.

At least 109 records · Page 6Linked to original sources
PubMed1994

A partial connectin cDNA encoding a novel type of RSP motifs isolated from chicken embryonic skeletal muscle.

A partial cDNA encoding 811 amino acids of connectin (titin), a giant elastic protein of muscle (3,000 kDa), was cloned from a chicken embryonic skeletal muscle cDNA library using antibodies to muscle connectin. The encoded product was the C terminal segment of connectin. The predicted sequences consisted of 5 type II motifs (immunoglobulin C2 type) separated by 5 interdomain insertions. One interdomain insertion had significant homology (RSP) to KSP repeats found in human cardiac C-terminal connectin and another had a high sequence homology to porin (67.7%; 31 amino acids).

Amino Acid Sequence↗
PubMed1994

Role of calcium-activated potassium channels in the relaxation of tracheal smooth muscles by forskolin.

1. The role of calcium-activated potassium (KCa) channels in bronchodilation produced by a direct adenylyl cyclase activator, forskolin, was investigated. The involvement of intracellular cyclic AMP (cAMP) in the process was also examined. 2. The isometric tension records from guinea-pig tracheal smooth muscles indicated that application of charybdotoxin (ChTX), a selective inhibitor of large conductance KCa channels, led to a suppression of the relaxant effect of forskolin in the precontracted tissue by carbachol (CCh). However, the inhibitory action by ChTX had a much greater effect on the relaxation caused by isoproterenol than by forskolin. 3. In contrast to the effect of ChTX, glybenclamide, a cromakalim-sensitive K+ channel inhibitor and apamin, a small conductance KCa channel blocker, had no effects on the bronchodilation produced by forskolin. 4. The effects of forskolin and nifedipine on tone produced by high K+ was compared. Concentration-inhibition curves in guinea-pig trachealis precontracted by 20 mmol/L K+ solution were similar for forskolin and nifedipine. Conversely, relaxation by forskolin was significantly diminished when tissues were contracted with 40 mmol/L K+ solution, whereas nifedipine relaxations were unaffected. 5. A single channel record from a cell-attached patch in a porcine tracheal myocyte demonstrated that forskolin stimulates reversibly KCa channels without affecting the unitary amplitude. 6. The results are consistent with forskolin-induced relaxation occurring at least in part through the opening of ChTX-sensitive KCa channels, by means of a cAMP-dependent channel modulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Beta-adrenergic agonists regulate KCa channels in airway smooth muscle by cAMP-dependent and -independent mechanisms.

Stimulation of calcium-activated potassium (KCa) channels in airway smooth muscle cells by phosphorylation-dependent and membrane-delimited, G protein actions has been reported (Kume, H. A. Takai, H. Tokuno, and T. Tomita. 1989. Nature [Lond.]. 341:152-154; Kume, H., M. P. Graziano, and M. I. Kotlikoff. 1992. Proc. Natl. Acad. Sci. USA. 89:11051-11055). We show that beta-adrenergic receptor/channel coupling is not affected by inhibition of endogenous ATP, and that activation of KCa channels is stimulated by both alpha S and cAMP-dependent protein kinase (PKA). PKA stimulated channel activity in a dose-dependent fashion with an EC50 of 0.12 U/ml and maximum stimulation of 7.38 +/- 2.04-fold. Application of alpha S to patches near maximally stimulated by PKA significantly increased channel activity to 15.1 +/- 3.65-fold above baseline, providing further evidence for dual regulatory mechanisms and suggesting that the stimulatory actions are independent. Analysis of channel open-time kinetics indicated that isoproterenol and alpha S stimulation of channel activity primarily increased the proportion of longer duration events, whereas PKA stimulation had little effect on the proportion of short and long duration events, but resulted in a significant increase in the duration of the long open-state. cAMP formation during equivalent relaxation of precontracted muscle strips by isoproterenol and forskolin resulted in significantly less cAMP formation by isoproterenol than by forskolin, suggesting that the degree of activation of PKA is not the only determinant of tissue relaxation. We conclude that beta-adrenergic stimulation of KCa channel activity and relaxation of tone in airway smooth muscle occurs, in part, by means independent of cyclic AMP formation.

Adenylyl Imidodiphosphate↗
PubMed1994

[Detection of Candida albicans by PCR].

Detection of Candida albicans by the polymerase chain reaction (PCR) was conducted. Oligonucleotide primers to amplify a 180 bp fragment on the beta-tubulin gene of C. albicans were synthesized. PCR was conducted using standard strains (14 species and 32 strains) and strains isolated from clinical samples (8 species and 12 strains) in Kitasato University Hospital. The PCR specifically amplified DNA from C. albicans of all standard strains and neither any other Candida, other fungal, bacterial nor human DNA. In three samples of clinically isolated C. albicans strains, the positive bands were also detected. This PCR procedure is more specific and rapid than the conventional culture method and is applicable to clinical diagnosis of the C. albicans infections.

Candida albicans↗
PubMed1993

A novel domain sequence of connectin localized at the I band of skeletal muscle sarcomeres: homology to neurofilament subunits.

A cDNA of 4.0 kb was cloned from a chicken embryo skeletal muscle cDNA library, using an antibody to muscle elastic protein connectin (titin), the molecular mass of which is estimated to be 3,000 kDa. Immunoelectron microscopy revealed that the antiserum raised against the product of the cDNA expressed in E. coli bound to the epitopes of the connectin filament near the N2 line of chicken breast muscle sarcomeres. The predicted amino acid sequence contains eight immunoglobulin C2 motifs and regions highly homologous with the high and medium molecular weight subunits of neurofilament. In addition, there are regions homologous with desmoplakin, calsequestrin, and calpastatin.

Amino Acid Sequence↗
PubMed1993

[A case of pulmonary aspergillosis by immunodiagnosis during remission induction therapy of acute myelocytic leukemia].

The frequency of a visceral mycosis grows definitely higher with an immunocompromised host. Invasive fungal infection can be controlled by means of development of early diagnosis and antifungal therapy. In these types of cases, it is difficult to establish an antemortem diagnosis of invasive pulmonary aspergillosis and most of them were diagnosed postmortem. A patient was diagnosed as aspergillosis from the clinical and serological features. This patient underwent successful therapy during remission induction therapy of acute myelocytic leukemia (AML). A 26-year-old male was admitted to our hospital because of leukocytosis with a diagnosis of AML made by reviewing peripheral blood smears and bone marrow aspirate. After remission induction therapy, he was still febrile in spite of treatment with a broad spectrum antibiotics and empiric therapy of fluconazole. Unfortunately shadowing appeared on the chest radiograph and aspergillus antigen was detected from the serum and the sputum. Consequently, the patient who suffered from invasive pulmonary aspergillosis was diagnosed and treated with intravenous amphotericin B and flucytosine. The radiological shadow improved but AML relapsed, therefore, remission induction therapy of AML was started again but he died of sepsis caused MRSA. In the postmortem histopathological examination the lung tissues, the hyphae could not be confirmed while, in immunohistochemical examinations of the lesion at the left S8, aspergillus antigens were detected around the small necrotic lesions and in the polymorphologic giant cells. We emphasize that invasive pulmonary aspergillosis is very difficult to diagnose whereas active examinations and clinical early diagnosis may lead to more effective therapy and the prognosis.

Adult↗
PubMed1992

Stimulatory and inhibitory regulation of calcium-activated potassium channels by guanine nucleotide-binding proteins.

The regulation of membrane ion channels by guanine nucleotide-binding proteins (G proteins) has been described in numerous tissues. This regulation has been shown to involve the membrane-delimited stimulatory action of G proteins on ion channels. We now show that single calcium-activated potassium channels (KCa channels) in airway smooth muscle cells are both stimulated and inhibited by G proteins in membrane patches. We demonstrate that the beta-adrenergic agonist isoproterenol stimulates channel activity via the alpha subunit of the stimulatory G protein of adenylyl cyclase, Gs, and that channel opening is inhibited by the action of the muscarinic agonist methacholine, acting via a pertussis toxin-sensitive G protein. Isoproterenol stimulated and methacholine inhibited channel activity in the same outside-out patches when GTP was present at the cytosolic surface of the patch. In inside-out patches, addition of GTP and guanosine 5'-[gamma-thio]triphosphate (GTP[gamma S]) augmented channel activity when isoproterenol was included in the patch pipette, and inhibited channel activity when methacholine was included in the pipette. Consistent with these results, in the presence of GTP[gamma S], the alpha subunit of Gs (alpha s.GTP[gamma S] complex) opened KCa channels in a dose-dependent manner, whereas in the presence of guanosine 5'-[beta-thio]diphosphate, alpha s had no effect. By contrast, application of activated alpha i or alpha o proteins did not inhibit channel activity in inside-out patches, indicating that channel inhibition is more complex than a simple alpha subunit/channel interaction, similar to the complex inhibitory regulation of adenylyl cyclase. These results suggest that hormonal regulation of KCa channels shares substantial features with the regulation of adenylyl cyclase and demonstrate that a single ion channel may serve as the regulatory target for the membrane-delimited action of stimulatory and inhibitory G proteins. Moreover, they demonstrate a potentially important functional pathway by which beta-adrenergic and other Gs-linked receptors stimulate relaxation of smooth muscle, independent of cAMP-dependent protein phosphorylation.

Adenylate Cyclase Toxin↗
PubMed1992

Muscarinic regulation of membrane ion channels in airway smooth muscle cells.

We have demonstrated that stimulation of airway smooth muscle by muscarinic agonists results in a coordinated modulation of two membrane ion channel proteins. Both channels are modulated in a similar way, although their effects on open-channel probability are opposite. The voltage-dependence of channel activity is shifted to more positive potentials in the case of KCa, and to more negative potentials in the case of the voltage-dependent calcium channels. Similarly, KCa channel dwell-time kinetics are shifted to short open lifetimes, whereas the long open state is favored for the large-amplitude voltage-dependent calcium channel. Although little is known about the molecular coupling of calcium channels, muscarinic inhibition of KCa channels is mediated through a pertussis toxin-sensitive guanine nucleotide binding protein.

Animals↗
PubMed1992

[A case of Trichosporon beigelii peritonitis in CAPD].

Continuous ambulatory peritoneal dialysis (CAPD) was introduced to Japan ten years ago and was established as the treatment for end-stage renal disease along with HD. Although the incidence of peritonitis in CAPD has decreased by educating the patients and parents and the improvement of various devises of CAPD, peritonitis is still one of the major complications of CAPD. Fungus is a rare pathogen for peritonitis in CAPD, but it must be considered as a causative agent in cases of intractable peritonitis. This report describes the first case of Trichosporon beigelii (T. beigelii) peritonitis in CAPD in Japan. A nine year old boy with chronic renal failure due to bilateral vesicoureteral reflux was given CAPD treatment four years prior to admission. This patient had been admitted to our hospital frequently because of recurrent bacterial peritonitis. The peritonitis in CAPD was usually treated by changing the peritoneal fluid and antibiotic treatment. In this case T. beigelii was proved to be a pathogen of peritonitis by culture of CAPD fluid and also serum antibody titers. T. beigelii infection was successfully eradicated from the peritoneal cavity by administration of MCZ and by the removal of peritoneal catheter. The patient was switched from CAPD to HD. In the case of intractable peritonitis in CAPD, rare fungal pathogens such as T. beigelii must be considered as a causative agent.

Child↗
PubMed1992

[Recent advances in ovarian cancer chemotherapy].

The standard approach for epithelial ovarian cancer has been maximum cytoreductive surgery followed by combination therapy. Several prospective control studies individually failed to demonstrate improved survival advantage for the Adriamycin containing combination compare with cisplatin plus cyclophosphamide. The two drug combination of carboplatin plus cyclophosphamide will be thought to become the treatment of choice, because it is equally effective as and less toxic than a regimen of cisplatin plus cyclophosphamide. Clinical trials are also in progress with more dose-intense regimens based on considerable retrospective evidence that survival is correlated with the dose intensity of platinum compounds. Currently, high dose carboplatin plus Gm-CSF, two-drug combination of carboplatin and cisplatin and super high dose carboplatin combined with autologous bone marrow transplantation are undergoing clinical trials. Taxol and taxotere, most important cancer drugs after emergence of cisplatin compound, has been shown to have clinical activity in drug resistant ovarian cancer patients. Majority of patients even with advanced germ cell tumors of the ovary is now cured because of the development of effective platinum-based combination chemotherapy of PVB or BEP.

Antineoplastic Agents, Phytogenic↗
PubMed1991

Muscarinic inhibition of single KCa channels in smooth muscle cells by a pertussis-sensitive G protein.

Application of a muscarinic agonist to the extracellular surface of membrane patches from airway smooth muscle cells resulted in an inhibition of calcium-activated potassium (KCa) channels in outside-out patches. Methacholine (50 microM) inhibited channel activity at physiological cytosolic calcium concentrations and resulted in a marked shift in channel open-time kinetics. In inside-out patches, KCa channels were inhibited upon addition of GTP (100 microM) when methacholine was present in the patch pipette. Muscarinic inhibition was blocked when guanosine 5'-O-(2-thiodiphosphate) was used to compete with endogenous GTP in outside-out or inside-out experiments. Pretreatment of dissociated cells with pertussis toxin (0.1 micrograms/ml) blocked muscarinic inhibition of the channel in a time-dependent fashion. These results demonstrate, at the single-channel level, a coupling between muscarinic receptor stimulation and inhibition of KCa in smooth muscle and demonstrate the guanine nucleotide dependence of this coupling.

Animals↗
PubMed1991

[Significance of serum ferritin level in testicular tumors].

The clinical value of serum ferritin level in patients with testicular cancer was studied. Seven cases of seminoma and nine cases of non-seminoma from 1983 to 1989 were evaluated. The serum levels of ferritin, human chorionic gonadotropin (beta-HCG), alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA) and lactate dehydrogenase (LDH) were estimated before and after treatment. Abnormally high values of serum ferritin before treatment were noted in 4/7 (57%) in seminoma, 3/9 (33%) in non-seminoma and 7/16 (44%) in total. The total rate showing abnormally high values of serum ferritin was lower than that of beta-HCG and LDH. Meanwhile it was the same as that of AFP and higher than that of CEA. Changes in the serum ferritin level did not always correspond with the clinical course. In 3 out of 6 tumor free patients, higher levels of serum ferritin before treatment became normal after treatment. In one patient with a high level of serum ferritin before treatment, the level of serum ferritin remained higher and retroperitoneal lymph node metastasis developed after treatment. In 9 cases with normal serum ferritin level, 7 showed the normal range of ferritin level throughout the treatment course. These findings suggests that in some patients with testicular cancer, the serum ferritin level might serve as a tumor marker indicating the efficacy of the treatment and the tumor recurrence.

Adult↗
PubMed1991

[Analysis of ferritin immunostaining in testicular tumors].

Localization of ferritin in testicular tumors was studied by the immunohistochemical method and the usefulness of ferritin was evaluated compared with the clinical course. Seven cases of seminoma and 9 cases of non-seminoma were used for the study. Formalin-fixed, paraffin-embedded tissue sections were stained by the avidin-biotin complex method. Commercial rabbit anti-human ferritin polyclonal antibody in 1/100 dilution was allowed to react at room temperature for one hour. In normal testicular tissues, the epithelium in germinal cells was not stained for ferritin. In seminomas, some tumor nests were stained for ferritin. Interstitial cells, especially histiocytes, were also stained for ferritin. In stained tumor cells, cytoplasm was stained uniformly. Necrotic cells were not stained. The same findings were obtained in non-seminomas. In metastatic lesions and tumor thrombi in the vessels, some tumor cells were stained as intensely as in the origin. A case was calculated positive if more than 5% of the tumor cells in the specimen were stained. The positive rate in ferritin immunostaining was significantly higher than that of human chorionic gonadotropin (beta-HCG), alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA) immunostaining with the same materials. The specimens from cases with abnormally high serum ferritin level, were stained more intensely than those from cases with normal serum ferritin level. The result suggests that ferritin might be a useful tumor marker in some of testicular tumors.

Adolescent↗
PubMed1990

Pulmonary aspergillosis due to Aspergillus terreus combined with staphylococcal pneumonia and hepatic candidiasis.

A female patient with systemic lupus erythematosus (SLE) developed pulmonary aspergillosis with staphylococcal pneumonia and hepatic candidiasis. Aspergillus terreus, which is a rare causative organism of pulmonary aspergillosis, was identified from a pulmonary lesion by culture. The aleurioconidium production, a characteristic of the genus Aspergillus sect. terrei, was demonstrated on short and irregular hyphal features in tissue sections. This report is the first of a combined case of pulmonary aspergillosis due to A. terreus with infections caused by other microorganisms.

Adult↗
PubMed1990

Effects of intracellular pH on calcium-activated potassium channels in rabbit tracheal smooth muscle.

1. The effects of intracellular pH (pHi) on calcium-activated potassium channels (Ca2(+)-activated K+ channels) were studied in membrane patches of smooth muscle freshly dispersed from the rabbit trachea. Single-channel currents were recorded with an 'inside-out' patch clamp technique, mainly at 0 mV, with the external (electrode) medium containing 130 mM-K+ and the internal (bath) medium 6 mM-K+. 2. With an internal Ca2+ concentration ([Ca2+]i) of 1 microM, the fraction of time during which the channel was in an open state (the open probability, Po) was more than 0.8 at pHi 7.4. The channel activity nearly disappeared at pHi 7.0. The [Ca2+]i-Po relationship was shifted to higher [Ca2+]i by acidosis, the shift being approximately an 8-fold increase for a fall in pHi of 0.5 units. 3. The membrane potential and current intensity (V-I) relationship of single channels between +30 and -50 mV was shifted in a hyperpolarizing direction by intracellular acidosis. The shift was roughly 10 mV for 1 pH unit at 1 microM [Ca2+]i. At pHi 7.4 [Ca2+]i 1 microM, the V-Po relationship was shifted in a depolarizing direction by acidification. When [Ca2+]i was increased to 10 microM, V-Po relationship became less sensitive to V as well as pHi changes. 4. When Po was high, the probability density function of open and closed time distributions could be fitted by two exponentials. When Po was decreased to less than 0.3, either by reducing [Ca2+]i or by lowering pHi, another component having long closed times appeared. At similar Po values, the time constant of open time distribution was smaller with lower pHi. 5. It is concluded that the main effect of an increase in intracellular hydrogen ions is to decrease the open probability of the Ca2(+)-activated K+ channel, by reducing the sensitivity to Ca2+ and also shortening the open state.

Action Potentials↗
PubMed1990

[A case of condyloma accuminatum around the anus in a married man].

A 34-year-old man was admitted to our hospital with warts around the anus persisting for the past four months as the chief complaint. There was no history of anal intercourse. All laboratory examinations of syphilis, hepatitis, chlamydia trachomatis, acquired immunodeficiency syndrome and other sexually transmitted diseases (STD) were negative. After application of amantadine, the warts disappeared completely in about two weeks. With diversification of sexual encounters, such a case of anal warts as a type of STD may increase in the domain of urology as well.

Adult↗
PubMed1989

Regulation of Ca2+-dependent K+-channel activity in tracheal myocytes by phosphorylation.

Isoprenaline is a beta-adrenergic agonist of clinical importance as a remedy for asthma. In airway smooth muscle its relaxant action is accompanied by hyperpolarization of the membrane and elevation of the level of intracellular cyclic AMP. Hyperpolarization and relaxation are also induced by drugs such as forskolin, theophylline and dibutyryl cAMP, indicating that cAMP-dependent phosphorylation is involved in producing the electrical response. Cyclic AMP-dependent protein kinase (protein kinase A) has been reported to activate Ca2+-dependent K+ channels in cultured aortic smooth muscle cells and snail neurons. The membrane of tracheal smooth-muscle cells is characterized by a dense distribution of Ca2+-dependent K+-channels. We have now examined the effect of isoprenaline and protein kinase A on Ca2+-dependent K+-channels in isolated smooth muscle cells of rabbit trachea, using the patch-clamp technique. Our results show that the open-state probability of Ca2+-dependent K+-channel of tracheal myocytes is reversibly increased by either extracellular application of isoprenaline or intracellar application of protein kinase A. We also show that this effect is significantly enhanced and prolonged in the presence of a potent protein phosphatase inhibitor, okadaic acid.

Animals↗