Biomedical subjects

T Yano

Publications and source records attributed to T Yano.

At least 361 records · Page 20Linked to original sources

PubMed1996

Purification and characterization of beta-D-glucosidase (beta-D-fucosidase) from Bifidobacterium breve clb acclimated to cellobiose.

The beta-D-glucosidase (EC. 3.2.1.21) activity of Bifidobacterium breve 203 was increased by acclimation with cellobiose, and the enzyme was purified to homogeneity from cell-free extracts of an acclimatized strain of B. breve clb, by ammonium sulfate fractionation and column chromatographies of anion-exchange, gel filtration, Gigapaite, and hydrophobic interaction. This enzyme had not only beta-D-glucosidase activity but also beta-D-fucosidase activity, which is specific to Bifidobacteria in intestinal flora. The molecular weight of the purified enzyme was estimated to be 47,000-48,000 and the enzyme was assumed to be a monomeric protein. The optimum pH and temperature of the enzyme were around 5.5 and 45 degrees C, respectively. The enzyme was stable up to 40 degrees C and between pH 5 and 8. The isoelectric point of the enzyme was 4.3 and the Km values for p-nitrophenyl-beta-D-glucoside and p-nitrophenyl-beta-D-fucoside were 1.3 mM and 0.7 mM, respectively. This enzyme had also transferase activity for the beta-D-fucosyl group but not for the beta-D-glucosyl group. The N-terminal amino acid sequence of this enzyme was similar to those of beta-D-glucosidase from other bacteria, actinomycetes, and plants.

Adult↗

PubMed1996

Cloning and nucleotide sequence of the beta-D-glucosidase gene from Bifidobacterium breve clb, and expression of beta-D-glucosidase activity in Escherichia coli.

Genomic DNA encoding a beta-D-glucosidase (EC 3.2.1.21), which has beta-D-fucosidase activity, was cloned from Bifidobacterium breve clb. We sequenced a 1.9-kbp cloned DNA fragment that contained a single open reading frame encoding 460 amino acids with a calculated molecular mass of 51,513 Da. A putative ribosome binding site was found 5 bp upstream of the initiation codon. The amino acid sequence of this beta-D-glucosidase from Bifidobacterium breve clb had 46% identity with that of beta-glucosidase from Microbispore bispore. The enzyme of Bifidobacterium breve clb was expressed in Escherichia coli. A cell-free extract prepared from the recombinant strain showed 80 to 90-fold more beta-D-glucosidase activity than that from Bifidobacterium breve clb. The recombinant enzyme was purified to homogeneity from cell-free extracts of the recombinant strain using 4 column chromatographies. The recovery of enzyme from the recombinant strain was about 138-fold-higher than that of Bifidobacterium breve clb. The enzymatic properties were similar to those of Bifidobacterium breve clb. For application of this recombinant enzyme, we attempted to synthesize a disaccharide that seemed to be specifically assimilated by Bifidobacteria using the condensation activity of the enzyme.

Amino Acid Sequence↗

PubMed1996

Effect of surgery on gonadal function of premenopausal women with pituitary adenomas other than prolactinomas.

The effects of surgery on pituitary-gonadal function were investigated in women with pituitary adenomas other than prolactinomas. The subjects were 46 women of premenopausal age with a pituitary adenoma. Twenty tumors were GH producing, 19 were nonfunctioning, and 7 were adrenocorticotropin producing adenomas. The surgery was performed mainly via the transsphenoidal route, with the aim of eradicating the tumor and preserving pituitary function. The menstrual cycle was preserved postoperatively in 9 out of 10 (90%) patients with regular preoperative menstruation. Menstrual disturbance was seen in 36 (78.3%) cases preoperatively. The causative factors for menstrual disturbance were gonadotropin impairment and hyperprolactinemia in GH producing and nonfunctioning adenoma. Excessive hormonal secretion itself is a major causative factor for menstrual disturbance in GH and ACTH producing adenoma. Regular menstruation was restored following surgery in 20 out of 36 (55.6%) patients with menstrual problems. The predicting factors for postoperative recovery of menstruation are: size of adenoma less than 40 mm, period of amenorrhea less than 5 years, and preoperatively preserved gonadotropin secretion. In addition, preoperative hyperprolactinemia was also a predicting factor in women with nonfunctioning adenoma. Thus, even in patients with pituitary adenomas other than prolactinoma, the restoration of menstruation is highly achievable when surgery is performed with attention to preserving pituitary function.

Adenoma↗

PubMed1996

Effects of surgery on testosterone secretion in male patients with pituitary adenomas.

The purpose of this study was to assess the effect of surgery on gonadal function in 42 male patients with pituitary adenomas Gonadal functions were evaluated by measuring total serum testosterone concentrations pre- and postoperatively. The subjects of the study were 20 patients with GH secreting adenoma, 7 patients with prolactinoma and 15 patients with nonfunctioning (NF) adenoma. Their ages ranged from 18 to 60 years (mean +/- SEM, 41 +/- 1.9). The serum testosterone concentration was low at less than 300 ng/dl preoperatively in 14 of 20 patients (70%) with GH producing adenoma, 6 of 7 patients (86%) with prolactinoma, and 7 of 15 patients (47%) with NF adenoma. Postoperatively, the total serum testosterone concentration was normalized in 9 of 14 patients (64%) with GH producing adenoma, one of 6 patients (17%) with prolactinoma, and 5 of 7 patients (71%) with NF adenoma. The normalization of serum GH and prolactin concentrations is indispensable for the restoration of gonadal function. It is very important to preserve the normal preoperative gonadotropin secretion by means of gentle surgery.

Adenoma↗

PubMed1996

[The influence of pregnancy and delivery on the climacteric symptoms].

This study was undertaken to investigate the influence of past pregnancy and delivery on the perimenopausal status in 144 women (48-52 years of age). Individual interviews to ascertain the personal profile, medical history, events at pregnancy, delivery and puerperium, and the kind and severity of climacteric symptoms were held. The subjects were divided into two groups by means of a simplified menopausal index (SMI): group A had climacteric symptoms (SMI > 50) and those in group B had mild symptoms (SMI < or = 50). The analysis of the principal components, and the correlation among the variables revealed that three factors--the impression and events at past pregnancies and deliveries, reproductive functions, and the psycho-character properties--had a significant influence on the status at the perimenopause, but the social-environmental factors appeared to have no significant influence on the severity of climacteric symptoms.

Climacteric↗

PubMed1996

Low-dose melphalan for treatment of high-risk myelodysplastic syndromes.

Twenty-one consecutive patients with high-risk myelodysplastic syndromes (MDS) including six with refractory anemia with excess blasts (RAEB) and 15 with RAEB in transformation (RAEBt) were treated with daily oral low-dose melphalan (2 mg/day). Seven patients achieved complete remission (CR), one patient partial response, and four minor response while the remaining eight did not respond. The median age of the patients was 65 (range 56-83 years). The mean total amount of melphalan given was 140+/-19 mg in patients who achieved CR. The median duration of CR was 14.5 months. Serious toxicity was not encountered in any of the cases. Neither marrow suppression nor pancytopenia was observed during the administration of melphalan in patients who achieved CR. The clinical features of CR patients included normal karyotype and hypocellular marrow in biopsied specimen from the lilac bone. These observations suggest that melphalan may exert some differentiation effects on leukemic cells in addition to cytotoxic effects. Our study indicates that daily administration of low-dose melphalan is worth trying in the treatment of elderly patients with high-risk MDS.

Aged↗

PubMed1996

[Pneumonia and mortality in patients requiring prolonged mechanical ventilation].

We examined patients who required prolonged (>60 days) mechanical ventilation. A total of 31 patients were studied, 23 with pulmonary disease, 4 with neurologic disease and 4 with other conditions. Many of these patients were elderly. The survival rates one year and two years after the start of mechanical ventilation were 40% and 33%, respectively. Respiratory tract infection was the most common and most serious complication, and ventilator-associated pneumonia was the main cause of death. It is difficult but quite important to prevent these complications, especially ventilator-associated pneumonia.

Adult↗

PubMed1996

Mutation of the ras genes is a rare genetic event in the histologic transformation of follicular lymphoma.

The role of ras gene mutations in the progression of follicular lymphoma has been ascertained by SSCP-PCR and sequencing. A total of 40 transformed lymphomas were studied, 16 of which had a matched preceding low-grade biopsy. Only one transformed lymphoma was found to have a missense mutation at codon 12 of N-ras, resulting in an amino acid change of glycine to serine. We conclude that mutation within the ras gene family is a rare event in the transformation of follicular lymphoma.

Base Sequence↗

PubMed1996

Detection of HHV-8/KSHV DNA sequences in AIDS-associated extranodal lymphoid malignancies.

Herpesvirus-like DNA sequences have been identified in a high proportion of both AIDS-associated and classical Kaposi's sarcoma, and in a small percentage of AIDS-associated malignant lymphomas. To determine the extent of involvement of this new agent designated HHV-8 (human herpesvirus type 8) or KSHV (Kaposi's sarcoma-associated herpesvirus) in human malignant lymphomas, we analyzed 24 AIDS-associated lymphoid malignancies and 100 non-AIDS-associated lymphomas by PCR and Southern blot analysis. Three of 24 lymphoid malignancies from patients with AIDS demonstrated HHV-8 sequences by Southern blot and PCR analyses. The fourth was positive by PCR only. None of the non-AIDS-associated lymphomas contained HHV-8 sequences. All three Southern blot positive samples were derived from extranodal regions, two from pleural effusions, and one from a soft tissue mass in the thigh. This latter patient initially presented with a pleural effusion. The fourth PCR positive but Southern blot negative tumor was from a gingival lymphoma in a patient with a history of Kaposi's sarcoma. All tumors positive for HHV-8 were also positive for EBV. These results confirm a recent report that this novel herpesvirus may play a role in AIDS-associated lymphomas especially in those with body cavity presentation.

Acquired Immunodeficiency Syndrome↗

PubMed1996

Susceptibility-weighted MR for evaluation of vasodilatory capacity with acetazolamide challenge.

PURPOSE: To investigate cerebral vasodilatory capacity by acetazolamide challenge in healthy subjects and in patients with chronic occlusive cerebrovascular disease by using susceptibility-weighted gradient-echo MR imaging. METHODS: Eight patients with chronic occlusive cerebrovascular disease and four healthy volunteers were studied with susceptibility-weighted MR imaging before and after intravenous administration of 1000 mg of acetazolamide. Signal intensities were measured as a function of time in several regions of interest defined on anatomic images. In all patients with chronic occlusive cerebrovascular disease, acetazolamide challenge and resting regional cerebral blood flow were also evaluated with single-photon emission CT (SPECT). RESULTS: In healthy volunteers, signal intensities began to increase 3 to 4 minutes after acetazolamide administration, with a continuous increase during the subsequent 10 minutes. The effect lasted for approximately 45 minutes after administration. In patients with chronic occlusive cerebrovascular disease, signal changes on susceptibility-weighted MR images of occluded areas with normal vasodilatory capacity on SPECT images did not differ from signal changes of nonocclusive areas. In those patients with changes that reflected diminished vasodilatory capacity, the MR images showed a lower percentage of signal changes after acetazolamide administration than those in normally perfused areas. CONCLUSION: Susceptibility-weighted MR imaging offers an alternative method for estimating vasodilatory capacity.

Acetazolamide↗

PubMed1996

[A case of coronary artery embolism after double valve replacement].

A 69-year-old woman with combined valvular heart disease (mitral regurgitation and aortic regurgitation), ascending aortic aneurysm, and atrial fibrillation underwent double valve replacement (DVR) and, ascending aortic wall plication. The postoperative thrombo-test level was around 20%. The ST elevation on ECG (II, III, aVFm, V4 approximately V6) with chest pain were recognized on the 13 th postoperative day. She was diagnosed as having acute myocardial infarction, and percutaneous transluminal coronary recanalization was performed immediately. The coronary angiogram showed occlusion at the left anterior descending branch (#8). This lesion could be recanalized by 6,000 U plasminogen pro activator (pro-UK) administration. The cineangiogram on the 35th postoperative day, revealed complete recanalization of this occlusion. Several cases of acute myocardial infarction associated with valvular heart diseases has been reported previously in Japan. However, there has been no report, except for this case, demonstrating occlusion in the coronary artery after prosthetic replacement and successful PTCR. So, this case is the first report on that point.

Aged↗

PubMed1996

[Clinical evaluation of fiberoptic bronchoscopy for the diagnosis of solitary pulmonary nodules 2 cm or less in diameter of chest roentgenogram].

The value of fiberoptic bronchoscopy in the diagnosis of solitary pulmonary nodules was studied. The subjects were 59 patients with chest-roentgenographic evidence of a solitary pulmonary nodule 2 cm or less in diameter. Definitive diagnoses were made in 34 patients (57.6%). Primary lung care was diagnosed 21 of 32 patients (65.6%), pulmonary tuberculosis in 7 of 12 (58.3%), metastatic lung cancer in 3 of 5 (60%), old lesions in 3 of 5 (60%), and pulmonary filariasis in 0 of 1 (0%). The diagnostic sensitivity of transbronchial biopsy was superior to that of curettage, and combining the two techniques further improved the diagnostic yield. Bronchial lavage was not effective for diagnosis of lung cancer, but was effective for diagnosis of pulmonary tuberculosis. Diagnostic yield was less for nodules in upper lobes than for those in other lobes, and most malignant tumors that were not diagnosed from the results of fiberoptic bronchoscopy were in upper lobes. We conclude that combining various fiberoptic bronchoscopic procedures can improve the diagnostic yield in patients with small pulmonary nodules. CT-guided needle biopsy and video-assisted thoracoscopic biopsy are two such procedures. Early diagnosis of small pulmonary nodules requires a skilled bronchoscopist who can choose the most appropriate method for biopsy.

Bronchoscopy↗

PubMed1996

[The quantitative regional cerebral blood flow measurement with autoradiography method using 123I-IMP SPECT: evaluation of arterialized venous blood sampling as a substitute for arterial blood sampling].

The purpose of this study is validation of calibrating a standard input function in autoradiography (ARG) method by one point venous blood sampling as a substitute for that by one point arterial blood sampling. Ten and 20 minutes after intravenous constant infusion of 123I-IMP, arterialized venous blood sampling from a dorsal vein were performed on 15 patients having ischemic cerebrovascular disease. And arterial blood sampling from radial artery was performed 10 min after 123I-IMP infusion. The mean difference rates of integrated input function between calibrated standard input function by arterial blood sampling at 10 min and that by venous blood sampling were 4.1 +/- 3% and 9.3 +/- 5.4% at 10 and 20 min after 123I-IMP infusion, respectively. The ratio of venous blood radioactivity to arterial blood radioactivity at 10 min after 123I-IMP infusion was 0.96 +/- 0.02. There was an excellent correlation between ARG method CBF values obtained by arterial blood sampling at 10 min and those obtained by arterialized venous blood sampling at 10 min. In conclusion, a substitution by arterialized venous blood sampling from dorsal hand vein for artery can be possible. The optimized time for arterialized venous blood sampling was 10 min after 123I-IMP infusion.

Aged↗

PubMed1996

[Pulmonary metastatic carcinoma of the rectum growing extensively in the bronchial lumen--a case report].

A 75-year-old man secondly developed a solitary pulmonary metastatic carcinoma of the rectum, who had undergone an operation for the first pulmonary metastatic disease in the left upper division segment before three years. The second tumor was about 2.0 cm in diameter, and located in the central area of the left lower lobe. At the time of operation, the tumor was found at the roots of both the B8 and the B9 bronchi, and thus removed by the basal segmentectomy. The resected specimen showed an endobronchial growth of metastatic adenocarcinoma in both the B8 and the B9 bronchi. Especially in the lumen of the B9 bronchus, the tumor dendritically extended from the central portion to the peripheral portion. The growing pattern of the tumor was very unique, and gave us attention to the extension of resection for metastatic lung carcinoma.

Aged↗

PubMed1996

[Effect of FUT-187, oral serine protease inhibitor, on inflammation in the gastric remnant].

Excessive enterogastric reflux following partial gastrectomy is believed to be responsible for the cause of inflammation in the gastric remnant. We examined the effect of FUT-187, a synthetic serine protease inhibitor, on symptoms and endoscopic findings in 33 patients who were diagnosed endoscopically as postgastrectomy gastritis. Patients took 50 mg FUT-187 orally after each meal and at bedtime for 8 weeks. Before treatment, 30 patients (91%) suffered from several symptoms including regurgitation and/or bitter taste in the mouth (49%), epigastric pain (42%) and nausea (36%). From endoscopic observation, erythema was detected in 32 patients, edema in 23 patients and erosion and/or ulcer in 9 patients. After treatment the global improvement rating for subjective symptoms was 76.7% (23/30) and the improvement of endoscopic findings was 63.6% (21/33). Diarrhea was observed in one patient but could be easily controlled by discontinuation of the drug. Our results suggest that FUT-187 can be a useful drug for the treatment of postgastrectomy gastritis with its efficacy and safety.

Administration, Oral↗

PubMed1995

Domains with transcriptional regulatory activity within the ALL1 and AF4 proteins involved in acute leukemia.

The ALLI gene, located at chromosome band 11q23, is involved in acute leukemia through a series of chromosome translocations and fusion to a variety of genes, most frequently to A4 and AF9. The fused genes encode chimeric proteins proteins. Because the Drosophila homologue of ALL1, trithorax, is a positive regulator of homeotic genes and acts at the level of transcription, it is conceivable that alterations in ALL1 transcriptional activity may underlie its action in malignant transformation. To begin studying this, we examined the All1, AF4, AF9, and AF17 proteins for the presence of potential transcriptional regulatory domains. This was done by fusing regions of the proteins to the yeast GAL4 DNA binding domain and assaying their effect on transcription of a reporter gene. A domain of 55 residues positioned at amino acids 2829-2883 of ALL1 was identified as a very strong activator. Further analysis of this domain by in vitro mutagenesis pointed to a core of hydrophobic and acidic residues as critical for the activity. An ALL1 domain that repressed transcription of the reporter gene coincided with the sequence homologous to a segment of DNA methyltransferase. An AF4 polypeptide containing residues 480-560 showed strong activation potential. The C-terminal segment of AF9 spanning amino acids 478-568 transactivated transcription of the reporter gene in HeLa but not in NIH 3T3 cells. These results suggest that ALL1, AF4, and probably AF9 interact with the transcriptional machinery of the cell.

Acute Disease↗

PubMed1995

Regulation of the expression of cathepsin B in Sarcophaga peregrina (flesh fly) at the translational level during metamorphosis.

Previously, we reported that cathepsin B of pupal hemocytes participates in dissociation of the fat body of Sarcophaga larvae at metamorphosis. In this study, we demonstrated that the amount of cathepsin B in hemocytes was controlled at the translational level, i.e. larval hemocytes stored a significant amount of untranslated cathepsin B mRNA. When the larvae pupated, translation of the mRNA commenced, resulting in accumulation of cathepsin B. Our results indicate that the 3'-untranslated region (3'-UTR) of this mRNA is necessary for the repression of its translation in a rabbit reticulocyte lysate. We detected the 3'-UTR binding protein in the lysate of larval hemocytes, but not in the pupal hemocytes. The role of this protein in the translation of cathepsin B mRNA is discussed.

Animals↗

PubMed1995

Expression and characterization of the 66-kilodalton (NQO3) iron-sulfur subunit of the proton-translocating NADH-quinone oxidoreductase of Paracoccus denitrificans.

The proton-translocating NADH-quinone oxidoreductase (NDH-1) of Paracoccus denitrificans is composed of at least 14 dissimilar subunits which are designated NQO1-14 and contains one noncovalently bound FMN and at least five EPR-visible iron-sulfur clusters (N1a, N1b, N2, N3, and N4) as prosthetic groups. Comparison of the deduced primary structures of the subunits with consensus sequences for the cofactor binding sites has predicted that NQO1, NQO2, NQO3, NQO9, and probably NQO6 subunits are cofactor binding subunits. Previously, we have reported that the NQO2 (25 kDa) subunit was overexpressed as a water-soluble protein in Escherichia coli and was found to ligate a single [2Fe-2S] cluster with rhombic symmetry (gx,y,z = 1.92, 1.95, and 2.00) (Yano, T., Sled', V.D., Ohnishi, T., and Yagi, T. (1994) Biochemistry 33, 494-499). In the present study, the NQO3 (66 kDa) subunit, which is equivalent to the 75-kDa subunit of bovine heart Complex I, was overexpressed in E. coli. The expressed NQO3 subunit was found predominantly in the cytoplasmic phase and was purified by ammonium sulfate fractionation and anion-exchange chromatography. The chemical analyses and UV-visible and EPR spectroscopic studies showed that the expressed NQO3 subunit contains at least two distinct iron-sulfur clusters: a [2Fe-2S] cluster with axial EPR signals (g perpendicular, parallel = 1.934 and 2.026, and L perpendicular parallel = 1.8 and 3.0 millitesla) and a [4Fe-4S] cluster with rhombic symmetry (gx,y,z = 1.892, 1.928, and 2.063, and Lx,y,z = 2.40, 1.55, and 1.75 millitesla). The midpoint redox potentials of [2Fe-2S] and [4Fe-4S] clusters at pH 8.6 are -472 and -391 mV, respectively. The tetranuclear cluster in the isolated NQO3 subunit is sensitive toward oxidants and converts into [3Fe-4S] form. The assignment of these iron-sulfur clusters to those identified in the P. denitrificans NDH-1 enzyme complex and the possible functional role of the NQO3 subunit is discussed.

Base Sequence↗