Biomedical subjects

T Yano

Publications and source records attributed to T Yano.

At least 343 records · Page 19Linked to original sources

PubMed1996

Expression and characterization of the flavoprotein subcomplex composed of 50-kDa (NQO1) and 25-kDa (NQO2) subunits of the proton-translocating NADH-quinone oxidoreductase of Paracoccus denitrificans.

This study reports the expression of the flavoprotein (FP) subcomplex of the proton-translocating NADH-quinone oxidoreductase (NDH-1) from Paracoccus denitrificans, which is composed of the NQO1 (50 kDa) and the NQO2 (25 kDa) subunits. The two subunits are co-expressed in Escherichia coli using a double expression plasmid system. The expressed subunits form a water-soluble heterodimer complex with 1:1 stoichiometry. The expressed complex contained one [2Fe 2S] cluster but almost no FMN or [4Fe 4S] cluster. The two latter prosthetic groups could be partially reconstituted with FMN, Na2S, and (NH4)2Fe(SO4)2 in vitro under anaerobic conditions. The reconstituted FP subcomplex showed EPR signals from two distinct species of iron-sulfur cluster. One resonance transition originates from a [2Fe-2S] cluster with g values of gx,y,z = 1.92, 1.95, and 2.00 and slow spin relaxation, which was tentatively assigned to the cluster N1a. These EPR properties are very similar to those reported for the NQO2 subunit expressed alone (Yano, T., Sled', V. D., Ohnishi, T., and Yagi, T. (1994) Biochemistry 33, 494-499). The other originates from a [4Fe 4S] cluster with g values of gx,y, z = 1.87, 1.94, and 2.04 and fast relaxing behavior, which are reminiscent of the cluster N3 in the membrane bound enzyme complex. After reconstitution with FMN, the FP subcomplex catalyzed electron transfer from NADH and from deamino-NADH to a variety of electron acceptors. The enzymatic properties of the FP subcomplex, reconstituted with FMN and iron-sulfur, correspond to those of the isolated P. denitrificans NADH-dehydrogenase complex.

Amino Acids↗

PubMed1996

An epitope on Ki antigen recognized by autoantibodies from lupus patients shows homology with the SV40 large T antigen nuclear localization signal.

OBJECTIVE: Epitopes on Ki antigen were analyzed using synthetic peptides, including KILT, a 16-mer peptide with an amino acid sequence homologous to the SV40 large T antigen nuclear localization signal (SV40 T NLS). METHODS: In addition to KILT, 4 synthetic peptides, all potential epitopes on Ki antigen according to computer analysis, were prepared and tested for reactivity with 49 anti-Ki-positive lupus sera by enzyme-linked immunosorbent assay. RESULTS: Eighteen sera reacted with KILT, but not with other peptides. The reaction of anit-Ki sera with KILT was specifically inhibited by recombinant Ki antigen. Eight of 49 anti-Ki sera reacted with a 7-mer synthetic peptide of SV40 T NLS, and the reaction was specifically inhibited by KILT. CONCLUSION: The 16-mer Ki peptide containing the sequence homologous to the SV40 T NLS is one of the antigenic epitopes recognized by anti-Ki antibodies in lupus sera.

Amino Acid Sequence↗

PubMed1996

Tracheal lipoma obstructing the right main bronchus: report of a case.

Most tracheal tumors are malignant, and benign neoplasms are extremely rare. We herein report the case of a 60-year-old woman with a tracheal lipoma obstructing the right main bronchus in whom a preoperative diagnosis was not able to be established. Thus, a thoracotomy was performed followed by complete resection of the tumor including two rings of the tracheal wall. Pathologic examination confirmed that the tumor was a lipoma covered with tracheal epithelium, extending between the cartilage into the outer layer of the trachea.

Bronchial Diseases↗

PubMed1996

Late development of hydrothorax induced by a central venous catheter: report of a case.

We report herein the case of a 47-year-old woman who suffered a hydrothorax induced by a central venous catheter (CVC) which had been placed to facilitate total parenteral nutrition following a left sleeve pneumonectomy for lung cancer. The CVC was inserted into the superior vena cava (SVC) through the left subclavian vein after the operation; however, the tip inadvertently turned upward and came in contact with the lateral wall of the SVC. The patient suddenly developed dyspnea due to a right-sided hydrothorax 47 days after the insertion of the catheter. Indocyamine green administered through the catheter was thereafter found in the pleural fluid. The continuous mechanical force of the catheter tip against the SVC wall was thus considered to be the cause of this life-threatening delayed hydrothorax.

Catheterization, Central Venous↗

PubMed1996

Type IV collagenase activity and cavernous sinus invasion in human pituitary adenomas.

Pituitary adenomas are regarded generally as benign tumours, but some of them can invade the cavernous sinus. On the other hand, matrix metalloproteinase-9 (MMP-9), which is a type IV collagenase, recently has been found to be expressed in matastases and to be related to the invasiveness of various malignant tumours including brain tumours. In order to investigate some characteristic features of pituitary adenomas which invade the cavernous sinus, we examined immunohistological studies for MMP-9 in seven pituitary adenomas for type IV collagen in a dura mater and assayed for type IV collagenase activity in seven adenomas using type IV collagen labelled with fluorescein isothiocyaniate (FITC). We found immunopositive adenoma cells for MMP-9 in all invasive adenoma and immunopositive spindle like cells for type IV collagen in the dura mater. All three invasive adenomas had high levels of type IV collagenase activity (0.57-0.72 U/ml), but the four adenomas which did not invade the cavernous sinus had low levels of type IV collagenase activity (0.0-0.10 U/ml). These results suggest that the level of type IV collagenase activity in a pituitary adenoma may be related to its ability to invade the cavernous sinus.

Adenoma↗

PubMed1996

Characterization of a lactate oxidase from a strain of gram negative bacterium from soil.

A lactate oxidase was purified about 36-fold from a newly screened strain KY6 of gram negative bacterium from soil to yield a homogeneous protein. The native enzyme had a molecular mass of 204 kDa measured by Sephadex G-200 and that of subunit on the SDS-PAGE was found to be 45 kDa. The enzyme was optimally active at pH 7.7 and showed stability at pH range of 5.7 to 9.5 for 24 h at 4 degrees C. The optimum temperature was 70 degrees C and the enzyme activity was stable for 10 min up to 45 degrees C. The half-life of the enzyme activity was about 10 min at 55 degrees C. The best substrate of the enzyme was D-lactate and Km value for D-lactate was 0.14 mM. The Km value for DL-lactate was 0.20 mM. Substrate inhibition of the enzyme was observed at higher concentrations than 20 mM of DL-lactate and 10 mM of D-lactate.

Gram-Negative Bacteria↗

PubMed1996

Skip metastasis to the mediastinal lymph nodes in non-small cell lung cancer.

BACKGROUND: Whether any difference exists in clinical characteristics between resected non-small cell lung cancer with either skip or ordinary mediastinal lymph node metastases (N2 disease) needs to be clarified. METHODS: There were 110 patients with stage IIIA N2 disease. Thirty-three patients demonstrating no metastasis at the hilar nodes [skip (+) group] were compared with the other 77 patients [skip (-) group]. To investigate the extent of nodal involvement, we classified the mediastinal lymph nodes into three regions (superior, inferior, or aortic). RESULTS: There were no significant differences regarding histologic type, T status, or the site of the primary tumors between the skip (+) and the skip (-) N2 groups. In the skip (+) group, mediastinal node metastasis was found in only one region (level 1) in 30 patients (90.9%) and in two regions (level 2) in 3 (9.1%), whereas 28 patients (36.4%) from the skip (-) group revealed mediastinal metastasis at two or three regions (level 2 or 3). The overall survival rate at 5 years after operation was 35% in the skip (+) group and 12.7% in the skip (-) group (p = 0.054). This favorable clinical outcome in the skip (+) group could be explained partially by the higher proportion of patients with level 1 metastases. Furthermore, regarding patients with level 1 disease, the skip (+) group tended to have a better prognosis than the skip (-) group (p = 0.096). CONCLUSIONS: These results suggest that patients with skip mediastinal lymph node metastases represent a unique subgroup of N2 disease.

Carcinoma, Non-Small-Cell Lung↗

PubMed1996

Release of fructose and hexose phosphates from perivascular cells induced by low density lipoprotein and acceleration of protein glycation in vitro.

We investigated whether low density lipoprotein (LDL) under oxidative stress might induce the release of fructose, glucose-6-phosphate and fructose-6-phosphate from perivascular cells, and also whether these substances might accelerate the formation of advanced glycation end products (AGE) from proteins in vitro. When vascular smooth muscle cells were incubated with LDL in Ham's F10 at 37 degrees C for 48 h. release of all these substances was increased dose-dependently by oxidized LDL. Fructose release was increased in a dose-dependent manner by glucose. Indomethacin (20 microM) significantly (P < 0.01) suppressed the release of fructose (25.4 +/- 15.7% of control) and hexose phosphates (29.4 +/- 4.0) with the inhibition of release of lactate dehydrogenase (35.5 +/- 4.9) as well as probucol, whereas an aldose reductase inhibitor, epalrestat, significantly (P < 0.001) inhibited only the fructose release (0.9 +/- 0.8). Release of fructose and hexose phosphates from vascular endothelial cells was also induced by oxidized LDL. AGE immunoreactivities and AGE-related fluorescence formed from proteins and glucose were significantly increased (P < 0.001) in the presence of small amounts of the cellular glucose metabolites (6.6%) with glucose (93.4%). These data suggest that release of potent AGE initiators, fructose and hexose phosphates, from perivascular cells induced by oxidized LDL may be an important phenomenon for vascular complications.

Aldehyde Reductase↗

PubMed1996

The clinical significance of serum soluble interleukin-2 receptors in lung cancer.

It has been recently reported that the soluble interleukin-2 receptor (IL-2R) levels in the sera of cancer patients were higher than those of normal controls. The present study was conducted in order to clarify the clinical significance of serum soluble IL-2R in patients with lung cancer. Using commercially available EIA kits, we measured the serum levels of soluble IL-2R in 102 lung cancer patients and 18 normal controls. The serum level of IL-2R was higher than 100 pM (mean +3 S.D. in the normal controls) in 14 of 58 patients with adenocarcinoma and in 13 of 32 patients with squamous cell carcinoma. In both adenocarcinoma and squamous cell carcinoma, the mean level of soluble IL-2R was higher in advanced stages (Stages IIIA, IIIB and IV) than in early stages (Stages I and II). In contrast, no patients with small cell carcinoma exhibited a serum level of soluble IL-2R higher than 100 pM, whereas almost all of those patients were in advanced-stage diseases. These results first demonstrated that the serum level of soluble IL-2R increased in association with both the disease stage and the histological type in lung cancer.

Adult↗

PubMed1996

Alpha-fetoprotein-producing adenocarcinoma of the lung.

We herein present a case of metachronous primary lung cancers, the first of which was adenosquamous cell carcinoma and the second of which was poorly differentiated adenocarcinoma. At the time the second lung cancer was detected 5 years after being operated on for the first cancer, a high level of serum alpha-fetoprotein (AFP) was noticed, but no elevation of other tumor markers was observed. In addition, no liver metastases, chronic liver diseases or other systemic abnormalities were seen either. The serum AFP level was 696 ng/ml, and the profile of lectin affinity showed a tumor-derived pattern. Two weeks after the operation, the serum AFP level decreased to a normal level. An immunohistochemical analysis confirmed that the exact origin of AFP was the tumor tissue. A specimen taken from the first lung cancer was not stained by the same procedures, which thus indicated this case to be a double primary lung cancer.

Adenocarcinoma↗

PubMed1996

Terminal components of carp complement constituting a membrane attack complex.

The membrane attack complex (MAC) of carp complement was extracted with deoxycholate from rabbit erythrocytes lysed by carp serum and purified by a two-step chromatographic procedure. On two-dimensional SDS-PAGE of carp MAC, eight bands were detected. The band of M(r) 91,000 was identified as carp C9 by western blotting using anti-carp C9, and two bands of M(r) 62,000 and one band of M(r) 22,000 were confirmed as those of carp C8 alpha, C8 beta and C8 gamma, respectively, by their N-terminal amino acid sequences. The bands of M(r) 102,000 and 73,000, which generated from a 180,000 band under reducing conditions, were those corresponding to human C5b alpha and C5b beta, respectively. The remaining bands of M(r) 115,000 and 106,000 were identified as those corresponding to human C6 and C7, as determined by their molecular size, single-chain structures and similarities in N-terminal amino acid sequences to their mammalian counterparts. Densitometric scan of the gels showed the molar ratio of C5b, C6, C7, C8 and C9 in carp MAC to be 1:1:1:1:4. Based on these results, it appears that, as with mammals, the cytolytic pathway of bony fish complement is composed of five terminal components from C5 to C9.

Amino Acid Sequence↗

PubMed1996

Purification and characterization of the eighth and ninth components of carp complement.

Complement components corresponding to mammalian C8 and C9 were isolated from carp (Cyprinus carpio) serum. Carp C8 (M(r) 146,000) proved to be a gamma-globulin composed of three polypeptide chains (alpha-chain, M(r) 62,000; beta-chain, M(r) 62,000; gamma-chain, M(r) 22,000). The alpha-chain was disulfide-linked to the gamma-chain and the beta-chain was non-covalently associated with the alpha-gamma chain, in fair agreement with mammalian C8. However, the N-terminal amino acid sequences of the three subunits showed no homology with those of human C8. Carp C9 was an alpha-globulin composed of a single polypeptide (M(r) 91,000) and the N-terminus was blocked. Carp serum depleted of C8 did not hemolyse either carp antibody-sensitized sheep erythrocytes or non-sensitized rabbit erythrocytes, while C9-depleted carp serum did not hemolyse the former, but did hemolyse the latter target cells, as in the case of C9-depleted human serum.

Animals↗

PubMed1996

Interleukin-2 receptors in pulmonary adenocarcinoma tissue.

We previously reported that the serum soluble interleukin-2 receptor (sIL-2R) level increased with the advance of disease stage in non-small cell lung cancer. The present study was thus conducted to investigate the origin of serum sIL-2R in patients with pulmonary adenocarcinoma. Fresh tumor cell suspensions were prepared from surgically resected specimens of pulmonary adenocarcinoma. They were adjusted to a cell density of 5 x 10(5)/ml and then cultured for 24 h at 37 degrees C. The culture supernatants were collected and assayed to determine the sIL-2R levels using an enzyme immunoassay. The resultant cells were thereafter cytocentrifuged onto glass slides and immunochemically stained with anti-human IL-2R alpha (CD25) monoclonal antibody. In three of six cases examined, a substantial level of sIL-2R was identified in the culture supernatants. In four cases, including those three cases with the presence of sIL-2R in the culture supernatants, various proportions of tumor cells were positively stained with the anti-IL-2R alpha antibody. Further examinations revealed that tumor cells expressed IL-2R alpha (CD25) in seven of 16 cases with pulmonary adenocarcinoma. These results thus suggested that the tumor cells did express IL-2R alpha and release sIL-2R in some cases with pulmonary adenocarcinoma.

Adenocarcinoma↗

PubMed1996

Urinary microalbumin as a marker for intermittent claudication.

OBJECTIVE: The urinary microalbumin concentration was analysed in patients with intermittent claudication in order to investigate its usefulness as a marker for intermittent claudication. MATERIALS AND METHODS: Urinary samples were collected prior to and following exercise in 15 patients with claudication. The patients walked on a treadmill as far as possible until they were stopped by pain. Urinary microalbumin concentration was measured by a latex agglutination system, and the result was considered abnormal when the concentration exceeded 10 mg/g creatinine. The ankle brachial pressure index (ABI) at rest and the time taken for the ankle pressure to return to the resting level following exercise (ABI recovery time) also were measured. RESULTS: In seven (47%) of the patients, the urinary microalbumin concentration was elevated to more than 10 mg/g creatinine following exercise, while in eight (53%) it remained normal. The ABI recovery time was significantly longer in the patients in whom the microalbumin concentration was elevated, compared to that in patients without an elevated concentration. The urinary microalbumin concentration following exercise was reduced significantly when the walking distance was decreased 50% or 15%. Following vascular bypass surgery, the elevation in urinary microalbumin concentration was reduced. CONCLUSIONS: The use of urinary microalbumin as a diagnostic marker for intermittent claudication is limited. However, in cases where the concentration is elevated, it can be used to follow the course of the disease.

Albuminuria↗

PubMed1996

Keratinocyte growth factor reduces lung damage due to acid instillation in rats.

Acid aspiration is a serious complication of anesthesia and other forms of unconsciousness that can result in the adult respiratory distress syndrome (ARDS), which continues to have a very high mortality despite our current therapeutic interventions. This type of injury damages the alveolar epithelium, principally alveolar type I cells, and requires proliferation of alveolar type II cells to restore gas exchange units. Since keratinocyte growth factor (KGF) has been shown to be a potent mitogen for alveolar type II cells, we evaluated whether intrabronchial administration of KGF would minimize lung injury due to the unilateral instillation of 0.1 N hydrochloric acid (HCl). Rats were pretreated or post-treated by intrabronchial instillation of KGF (5 mg/kg) into the left lung before HCl instillation. All rats receiving KGF at 48 or 72 h before HCl instillation survived for the 7-day observation period, whereas the mortality rate for those receiving HCl alone or saline followed by HCl was 31% and 33%, respectively. Pretreatment with KGF at 72 h but not at 24 or 48 h considerably ameliorated morphologic damage produced by HCl. Inflammatory cells in bronchoalveolar lavage were markedly decreased 3 and 7 days after HCl instillation by the 72-h KGF pretreatment. Pretreatment with KGF at 72 h also attenuated the reduction of total lung capacity, decreased the alpha 1(I) procollagen mRNA levels, and diminished hydroxyproline accumulation due to HCl instillation. Saline pretreatment at 72 h had no significant effect on the HCl injury and subsequent physiologic abnormalities. Our attempts to improve outcome with post-treatment instillation of KGF were unsuccessful. We conclude that KGF pretreatment reduces lung injury due to acid instillation and can prevent subsequent pulmonary fibrosis.

Administration, Inhalation↗

PubMed1996

Fas/APO-1/CD95 system as a mediator of granulosa cell apoptosis in ovarian follicle atresia.

Current studies have shown that atresia of ovarian follicles is induced through apoptosis in granulosa cells. Several articles have been devoted to study of the molecular mechanisms responsible for APO-1/CD95 (Fas) is a cell surface protein that can mediate apoptosis in lymphoid cells, and Fas ligand was recently identified in a cytotoxic T cell line. To clarify the involvement of the Fas-Fas ligand system in granulosa cell apoptosis, we investigated the expression of Fas and Fas ligand at an individual cell level. For this purpose, we raised specific polyclonal antibodies against Fas and Fas ligand. Western blotting confirmed that our anti-Fas antibodies (anti-P2 and anti-P4) detect a specific band with a mol wt of 45 kDa in the lysate of ovaries from immature PMSG-treated rats or adult cyclic rats. In immature PMSG-treated rats, immunohistochemical analysis with these antibodies revealed specific staining of granulosa cells in secondary and tertiary follicles at an early stage of atresia, but not in healthy follicles. Fas messenger RNA was also found in granulosa cells of early atretic follicles using in situ hybridization. On the other hand, the anti-Fas ligand antibody (anti-P5) detected a specific 31-kDa band on a Western blot of the oocytes lysate, and the staining with the serum was localized to oocytes in most of developing follicles. Colocalization of Fas and Fas ligand in certain follicles intimately correlated with granulosa cell apoptosis, which was revealed by terminal deoxynucleotidyl transferase-mediated deoxy-UTP-biotin nick end labeling staining of DNA strand breaks. Finally, we found that interferon-gamma increased Fas expression on granulosa cells in vitro. Coculturing interferon-gamma-pretreated granulosa cells with zona-free oocytes induced granulosa cell apoptosis, which was confirmed by Hoechst 33342 dye staining and terminal deoxynucleotidyl transferase-mediated deoxy-UTP-biotin nick end labeling, and the killing effect of oocytes was abolished by the addition of anti-P2, which was expected to interrupt the interaction between Fas and Fas ligand. These results demonstrate that activation between Fas and Fas ligand. These results demonstrate that activation of the Fas-Fas ligand system is capable of initiating apoptosis in the ovary, as are a number of other stimuli, outside the immune system.

Animals↗

PubMed1996

[Effects of lacidipine, a new dihydropyridipine derivative, on various cerebral ischemia models].

We examined the cerebral protective effects of lacidipine (L) using three different types of cerebral ischemia models, and the effects were compared with those of nicardipine (N). (1) In the transient forebrain ischemia model of the rat, oral administration of L (0.3 and 1 mg/kg) before ischemia significantly decreased the number of acidophilic neurons in CA1 regions of the hippocampus 7 days after ischemia. N (3 mg/kg, p.o.) before ischemia also produced a significant reduction in the number of acidophilic neurons, and it's effectiveness was almost the same as that of L (1 mg/kg). (2) In the focal cerebral ischemia model of the rat, oral administration of L (1 and 3 mg/kg) before of after left middle cerebral artery occlusion (MCAO) significantly reduced infarct size at 24 hr after MCAO. Such an ameliorative effect was also observed when N was administered orally. However, the effect of N at 30 mg/kg was less than that of L at 1 mg/kg. (3) In the delayed cerebral vasospasm model of the dog after subarachnoid hemorrhage (SAH), intravertebral artery injection of L (10 micrograms/kg) or N (10 micrograms/kg) dilated the contracted basilar artery 3 days after SAH to the level before SAH. Finally, while both L and N increased cerebral blood flow (CBF) in a dose-dependent manner in conscious normal rat, the increment of CBF induced by L at a given level of reduced-blood pressure was greater than that induced by N. These results indicate that lacidipine may be a potential therapeutic agent that exerts a protective effect against brain damage after cerebral ischemia.

Animals↗

PubMed1996

Acid lipase inhibitor in chicken plasma identified as apolipoprotein A-I.

We have reported a inhibitor of acid lipases in liver lysosomes and erythrocytes from chickens [M. Fujii et al., Int. J. Biochem., 22, 895-898 (1990)]. In this paper, the properties of the inhibitor were described in comparison with those of apo A-I of chicken. The purified inhibitor migrated with the same mobility on SDS-PAGE as apo A-I, and had a molecular weight of 27,000. The peptide map from the lipase inhibitor was similar to that of apo A-I. Antibodies to the acid lipase inhibitor also reacted with apo A-I. Apo A-I inhibited the acid lipase activities of liver lysosomes and erythrocytes from chickens as strongly as the lipase inhibitor. The N-terminal amino acid sequence of lipase inhibitor was identical to that of apo A-I as far as residue 20. The amino acid sequence of peptides obtained from the inhibitor by cleavage with CNBr corresponded to internal sequence of apo A-I, and so the CNBr-peptides were derived by cleavage after the methionine residues in apo A-I. The findings showed that the inhibitor of the acid lipases in liver lysosomes and erythrocytes from chickens was identical to apo A-I.

Amino Acid Sequence↗