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Biomedical subjects

M Kubota

Publications and source records attributed to M Kubota.

At least 271 records · Page 15Linked to original sources
PubMed1996

Effect of phenylethanolamine N-methyltransferase inhibitor, CGS19281A, on the alpha-2-adrenoceptor function in the hypothalamus of rats in comparison with SKF29661, SKF64139 and yohimbine.

CGS19281A, a phenylethanolamine N-methyltransferase (PNMT) inhibitor, is reported not to inhibit alpha-2-adrenoceptor activity, in vitro. Effects of CGS19281A on the hypothalamic alpha-2-adrenoceptor function were studied in vivo in male Wistar rats. Agents used as controls were SKF29661, which is a selective peripheral PNMT inhibitor, SKF64139, a PNMT inhibitor that inhibits equally both alpha-2-adrenoceptor activity and PNMT, and yohimbine, an alpha-2-adrenoceptor inhibitor that does not inhibit PNMT. Following the administration of PNMT inhibitors, hypothalamic 3-methoxy 4-hydroxy phenylglycol (MHPG) was measured during micro brain dialysis to observe its fluctuations. Effects of PNMT inhibitors on growth hormone (GH) secretion caused by clonidine were examined in order to assess the effects of PNMT inhibitors on postsynaptic alpha-2-adrenoceptors in the hypothalamus. Neither saline nor the peripherally active PNMT inhibitor SKF29661 (50 mg/kg) increased hypothalamic MHPG. Both SKF64139 (50 mg/kg) and yohimbine (5 mg/kg) increased MHPG significantly when compared with SKF29661. There was no significant increase in MHPG after the administration of CGS19281A (20 mg/kg). Blood GH increased 30 min after clonidine was administered. While CGS19281A (20 mg/kg), SKF64139 (50 mg/kg) and yohimbine (5 mg/kg) inhibited GH secretion, the peripherally active PNMT inhibitor SKF29661 (50 mg/kg) did not. These results suggest that CGS19281A has an in vivo inhibitory effect on the clonidine induced GH secretion. This may be due to inhibition of adrenaline synthesis by this agent.

Animals↗
PubMed1996

Purification and characterization of thermostable maltooligosyl trehalose synthase from the thermoacidophilic archaebacterium Sulfolobus acidocaldarius.

A thermostable maltooligosyl trehalose synthase was purified from a cell-free extract of the thermoacidophilic archaebacterium Sulfolobus acidocaldarius ATCC 33909 to an electrophoretically homogeneous state by successive column chromatography on Sepabeads FP-DA13, Butyl-Toyopearl 650M, DEAE-Toyopearl 650S, Ultrogel AcA44, and Mono Q. The enzyme had a molecular mass of 74,000 by SDS-polyacrylamide gel electrophoresis and a pI of 5.9 by gel isoelectrofocusing. The N-terminal amino acid of the enzyme was methionine. The enzyme showed the highest activity from pH 5.0 to 5.5 and at 75 degrees C, and was stable from pH 4.5 to 9.5 and up to 85 degrees C. The enzyme activity was inhibited by Hg2+ and Cu2+. The Kms of the enzyme for maltotetraose, maltopentaose, maltohexaose, maltoheptaose, and short chain amylose (DP 18) were 41.5 mM, 7.1 mM, 5.7 mM, 1.4 mM, and 0.6 mM, respectively.

Amino Acid Sequence↗
PubMed1996

Purification and characterization of thermostable maltooligosyl trehalose trehalohydrolase from the thermoacidophilic archaebacterium Sulfolobus acidocaldarius.

A thermostable maltooligosyl trehalose trehalohydrolase from the thermoacidophilic archaebacterium Sulfolobus acidocaldarius ATCC 33909 was purified from a cell-free extract to an electrophoretically pure state by successive column chromatographies on Sepabeads FP-DA13, Butyl-Toyopearl 650M, DEAE-Toyopearl 650S, Toyopearl HW-55S and Ultrogel AcA44. The enzyme had a molecular mass of 59,000 by SDS-polyacrylamide gel electrophoresis and a pI of 6.1 by gel isoelectrofocusing. The N-terminal amino acid of the enzyme was methionine. The enzyme showed the highest activity from pH 5.5 to 6.0 and at 75 degrees C, and was stable from pH 5.5 to 9.5 and up to 85 degrees C. The activity was inhibited by Hg2+, Cu2+, Fe2+, Pb2+, and Zn2+. The Km values of the enzyme for maltosyl trehalose, maltotriosyl trehalose, maltotetraosyl trehalose, and maltopentaosyl trehalose were 16.7 mM, 2.7 mM, 3.7 mM, and 4.9 mM, respectively.

Chemical Phenomena↗
PubMed1996

Cloning and sequencing of trehalose biosynthesis genes from Rhizobium sp. M-11.

The two genes encoding maltooligosyl trehalose synthase and maltooligosyl trehalose trehalohydrolase, which are related to biosynthesis of alpha, alpha-trehalose, were cloned from Rhizobium sp. M-11. Sequence analysis showed that the synthase gene composed of 2316 bp was connected with the hydrolase gene of 1788 bp by an overlap of one nucleotide. The deduced amino acid sequences of both enzymes have several regions common to amylolytic enzymes belonging to an "alpha-amylase family".

Amino Acid Sequence↗
PubMed1996

Slow-reacting and complement-requiring neutralizing antibody in swine infected with porcine reproductive and respiratory syndrome (PRRS) virus.

Various conditions were evaluated and modified to enhance the sensitivity of the neutralization (NT) test for detecting antibody in swine infected with porcine reproductive and respiratory syndrome (PRRS) virus. Higher NT antibody titers were consistently obtained by the addition of 10% (v/v) complement, fresh guinea pig serum, to the virus diluent and by the incubation of serum-virus mixture at 4 degrees C for 24 hr. The appearance and persistence of antibodies detected by the modified NT test showed a similar pattern to those of antibodies detected by the indirect fluorescent antibody (IFA) assay, although the antibody titers obtained by the former method were consistently lower than those obtained by the latter method. Slow-reacting complement-requiring NT antibody was detected in sera from pig 2 weeks after infection with PRRS virus. The slow-reacting complement-requiring NT antibody in the early serum samples was sensitive to 2-mercaptoethanol (2-ME), whereas the slow-reacting complement-requiring NT antibody in the late serum samples was resistant to 2-ME. The initial phase may represent the IgM response and the later phase a change to IgG. A NT test was developed in which serum-virus mixtures were incubated at 4 degrees C for 24 hr with complement; this gave an improved sensitivity over the previous incubation at 37 degrees C for 60 min.

Animals↗
PubMed1996

Effect of resinous temporary material on tensile bond strength of resin luting cement to tooth substrate.

We investigated the effect of resinous temporary material on the tensile bond strength of resin luting cement to enamel and to dentin. Four hundred bovine incisor teeth were randomly divided into groups. Four resinous temporary materials and four resin luting cements were used. On enamel, none of the resinous temporary materials decreased the tensile bond strength of the cements. On dentin, all the resinous temporary materials decreased the tensile bond strength of the cements except one containing 4-META/MMA-TBB.

Animals↗
PubMed1996

[Measurement of adenosine deaminase activity in bronchoalveolar lavage fluids as a tool for diagnosing miliary tuberculosis].

Measurement of the activity of adenosine deaminase (ADA) in pleural effusions has been reported to be useful in the diagnosis of tuberculous pleuritis. To determine whether ADA activity can also be used to diagnose miliary tuberculosis, it was measured in bronchoalveolar lavage fluid from 64 subjects: 6 patients with miliary tuberculosis, 21 patients with sarcoidosis, 15 patients with idiopathic interstitial pneumonia, 15 patients with other diseases, and 7 healthy controls. Mean ADA activity was 5.02+/-3.75 IU/L (mean+/-SD) in patients with miliary tuberculosis; 1.06+/-0.99 IU/L in patients with sarcoidosis; 0.21+/-0.43 in patients with idiopathic interstitial pneumonia; and 0.30+/-0.51 IU/L in healthy controls. The level in patients with miliary tuberculosis differed significantly from the others (p<01.01). All 6 patients with miliary tuberculosis, 3 patients with sarcoidosis, 1 patient with Wegener's granulomatosis, and 1 patient with lymphangitic carcinomatosis had levels of ADA activity in bronchoalveolar lavage fluid that exceeded 2.0 IU/L. With a cut-off value of 2.0 IU/L the sensitivity of this test to miliary tuberculosis is higher than that of other diagnostic aids. Measurement of ADA activity in bronchoalveolar lavage fluid may be of great value in the early diagnosis of miliary tuberculosis.

Adenosine Deaminase↗
PubMed1996

[A case of spontaneous rhinorrhea detected by SPAMM-tagging method].

This is the first report of rhinorrhea detected by special modulation of the magnetization (SPAMM)-tagging method. A 54-year-old male was admitted to our hospital for treatment of right rhinorrhea which had continued for 2 months and a half. The CSF leakage was induced by specific head position and the volume was more than 50 ml a day. Metrizamide CT cisternography revealed the contrast medium in the lateral extension of the right sphenoid sinus. MRI demonstrated liquorrhea with abnormal intensity of the sinus. 3D-CT revealed bony defects at the temporal base. Operation revealed herniated brain through the same bony defect of the temporal base into the extended sphenoid sinus. Post-operative diagnosis was Morley's rhinorrhea. The leakage point was closed and patched with the femoral fascia. Preoperative SPAMM-tagging image with cine MRI was useful to identify the responsible leakage point as a disorder of lattice tags. This method is a kind of flowmetry with MRI and is very effective because it can detect non-invasively slight CSF motion into the sinuses. It can also detect the direction and rough flow volume of rhinorrhea, so may also predict the risk of meningitis. The disadvantages were also discussed.

Cerebrospinal Fluid Rhinorrhea↗
PubMed1996

[Electrophysiological examinations in Bell's palsy using electroneuronography and strength-duration curve].

In 30 patients with Bell's palsy electroneuronography (ENoG) and strength-duration curve (S-D curve) were used to evaluate the recovery from the palsy at the orbicularis oris and the oculi muscles. At the orbicularis oris muscle, the final outcome was poor in the patients in whom minimum ENoG < 10%, and all the patients with 30% <or= minENoG showed good recovery. In the patients with 10 <or= minENoG < 30, when S-D curve was without scale out, all the patients showed complete recovery. The recovery in the orbicularis oculi muscle of the patients with minENoG < 10% was all poor, but two patients with 30% <or= minENoG, remained in the impaired situation, and one patient with 10 <or= minENoG < 30, without scale out in S-D curve showed poor recovery. These findings suggests that electrophysiological examinations using ENoG and S-D curve in the patients with Bell's palsy can provide valuable information at the orbicularis oris muscle, but at the orbicularis oculi muscle, these are less reliable.

Adolescent↗
PubMed1996

[Serum levels of remnant-like particles-cholesterol (RLP-C) in patients on hemodialysis].

Serum remnant-like particles-cholesterol (RLP-C), an atherosclerosis risk factor that strongly reflects disorders of chyromicron and VLDL metabolism and contains high levels of TG, was measured in patients on hemodialysis and CAPD. The purpose of this study was to determine the serum levels of RLP-C in 30 outpatients on hemodialysis (18 males, 12 females) and 84 patients on CAPD (53 males, 31 females). The serum RLP-C level was 8.1 +/- 13 mg/dl in CAPD patients and 2.7 +/- 0.2 mg/dl in hemodialysis patients (p < 0.001). Patients who used dialysate containing over 150 g of glucose per day, showed higher levels of serum RLP-C than CAPD patients whose glucose consumption was under 150 g (10.4 +/- 2.4 mg/dl vs. 5.5 +/- 0.6 mg/dl, p < 0.01). There was no statistical relationship between age, sex, dialysis duration and serum RLP-C in CAPD and hemodialysis patients. Serum level of RLP-C was positively correlated with serum triglyceride, total cholesterol, apolipoprotein B and VLDL, and was negatively correlated with apoA-I/apoB in the dialysis patients. It appears that RLP-C, which is one of the risk factors of atherosclerosis, might reflect a disorder of triglyceride metabolism in patients on dialysis, especially on CAPD.

Adult↗
PubMed1996

Study on ultrasonically guided fine-needle aspiration cytology for breast disorders with high-resolution transducer.

The author participated in the development annular array transducer. The author used this new device in 147 patients (aged 43.4 years ranging from 21 to 81 years) and ultrasonically detected 193 breast lesions including 126 nonpalpable ones (65.3%). After that, the author performed 234 punctures for aspiration cytology using the same device and 22 gauge needle. The needle tip was intralesionally identified in 174 of the 234 punctures (74.4%) and 146 of the 193 lesions (75.6%). The sensitivity, specificity and accuracy of cytological diagnosis were 72.7% (8/11), 91.2% (31/34) and 86.7% (39/45), respectively. No cell could be aspirated in 61 of the 146 lesions (41.8%). These results were comparable to those obtained from the conventional devices. Annular array transducer will increase the frequency of ultrasonic detection of small breast lesions. Fine needle aspiration cytology under ultrasonic guide with this new device will efficiently and speedily rule out malignant lesions and facilitate management of benign lesions at the outpatient department. This study suggests that ultrasonically malignant lesions should immediately be examined histologically without undergoing cytological examination. It should be noted that some cystic lesions are concentrated and accompanied by positive internal echoes. These cystic lesions show a change in size on the ultrasonic image after aspiration and contain paste- or gruel-like material.

Adult↗
PubMed1995

A 13-Mer peptide of a brain injury-derived protein supports neuronal survival and rescues neurons from injury caused by glutamate.

Neuronal survival is mediated by several kinds of proteins. Among these, neurotrophic factors play important roles in the nervous system by supporting neuronal activity and survival. It has been suggested recently that certain factors promote neuronal survival in the case of brain injury. To examine this possibility, we purified a novel neurotrophic factor from Gelfoam that was implanted at the site of injury caused in neonatal rats. During amino acid sequence analysis, we found that a fragmental peptide of this neurotrophic protein consisting of 13 amino acids showed neurotrophic activity. This 13-mer peptide promoted survival of septal cholinergic and mesencephalic dopaminergic neurons in culture and rescued hippocampal neurons from injury caused by glutamate in culture. This peptide rescued neurons from cell death caused by glutamate, even when added 4.5 h after glutamate exposure.

Amino Acid Sequence↗
PubMed1995

Expression of CD38 gene, but not of mitochondrial glycerol-3-phosphate dehydrogenase gene, is impaired in pancreatic islets of GK rats.

Goto-Kakizaki (GK) rat, a rodent model of spontaneously occurring non-insulin dependent diabetes mellitus (NIDDM), exhibits impaired glucose-stimulated insulin secretion. To explore the background of the beta-cell dysfunction in NIDDM, we investigated whether and how the expression pattern of factors that would potentially be involved in the glucose-stimulated insulin secretion machinery is changed in GK rats. Using quantitative reverse transcription-PCR (RT-PCR) method, we found that the gene expression of CD38, a type 2 membrane protein which has ADP-ribosyl cyclase activity, is reduced by approximately 50% in islets of GK rats. Despite previous studies showing reduction in the FAD-linked mitochondrial glycerol-3-phosphate dehydrogenase (mGPDH) activity in GK rats, the mGPDH mRNA amounts were equal to those in the control Wistar rats, suggesting a difference that arose post-transcriptionally. These observations support the idea that multiple defects of the glucose-responsive insulin secreting machinery are involved in the development of diabetes in GK rats.

ADP-ribosyl Cyclase↗
PubMed1995

Selection and partial characterization of calcium ionophore (A23187) resistant cells.

We have selected calcium ionophore (A23187)-resistant cells (AR-7) in a human promyelocytic leukemia cell line, HL-60. AR-7 showed approximately 8.5-fold resistance to A23187 compared with the wild type cells after continuous exposure for 3 days. AR-7 had cross resistance to ionomycin (4.6-fold) and thapsigargin (340-fold) which can also increase intracellular Ca++. Similar magnitude of resistance to apoptosis, as defined by characteristic morphology and internucleosomal DNA fragmentation, induced by these agents was observed after 4 hr of incubation. However, both the elevation of intracellular Ca++ following stimulation with various concentrations of A23187 and the sensitivity to anti-cancer agents including etoposide, 1-beta-D arabinofuranosylcytosine, and hydroxyurea were comparable between the two cell types. This cell line is considered to be useful for exploring the mechanism(s) of cell death, especially apoptosis, induced by calcium ionophore.

Antineoplastic Agents↗
PubMed1995

Association of high molecular weight DNA fragmentation with apoptotic or non-apoptotic cell death induced by calcium ionophore.

Calcium ionophore (A23187)-induced high molecular weight (HMW) and internucleosomal DNA fragmentation were investigated in human leukemia cell lines. An apoptosis-sensitive cell line, HL-60, showed HMW, internucleosomal DNA fragmentation and morphological changes of apoptosis by A23187. MOLT-4, which is resistant to apoptosis, exhibited only HMW DNA fragmentation and died of necrosis under the same conditions. Autodigestion experiments suggested the endonucleolytic activity to cause HMW fragmentation in the cytoplasm of both cell lines. The activity was more dependent on Mg2+ than Ca2+ in HL-60, whereas it was Ca(2+)-dependent in MOLT-4. These results suggest that HMW DNA fragmentation is not specific to apoptosis.

Apoptosis↗