Biomedical subjects

R Kobayashi

Publications and source records attributed to R Kobayashi.

At least 217 records · Page 12Linked to original sources

PubMed1996

Measurement of 1268 nm emission for comparison of singlet oxygen (1 delta g) production efficiency of various dyes.

Singlet oxygen generation from laser-excited photosensitive dyes was measured directly using a sensitive near-infrared emission spectrometer to monitor the O2(1 delta g)-->O2(3 sigma -g) transition at 1268 nm. The emission intensity was proportional to both the laser power and the concentration of the dyes. The singlet oxygen producing ability of the dyes was compared with that of eosin YS as a standard in methanol. The relative efficiencies of singlet oxygen generation were determined for rose bengal, erythrosine B, phloxine B and eosin YS as 2.39, 1.73, 1.38, 1.00, respectively, while uranine showed no emission in this spectral region. Using rose bengal, erythrosine B, phloxine B and eosin YS, the efficiency of singlet oxygen generation correlated with the photobleaching reaction rate of azo-dyes by these dyes, suggesting singlet oxygen to be a species responsible for causing the photobleaching of azo-dyes. The halogen substituent effect on the efficiency of singlet oxygen generation from laser-excited photosensitive dyes was also examined systematically.

Azo Compounds↗

PubMed1996

Clara cell protein correlation with hyperlipidemia.

Serum levels of protein 1 (P1), a Clara cell secretory protein, in 746 healthy subjects were measured and their correlations with different types of serum lipids and lipoproteins-that is, triglyceride (TG), total cholesterol (TCh), free cholesterol (FCh), high-density lipoprotein (HDL), low-density lipoprotein (LDL), and apoproteins (apo) A-I, A-II, and B-were examined. P1 serum levels were examined for their correlation with body mass index (BMI), and were compared for 47 obese, 70 normal, and 17 lean males. P1 serum levels in 69 patients with diabetes mellitus and 24 patients with atherosclerotic stenosis of the carotid artery or coronary artery were also compared to those in healthy control subjects. P1 showed a significant positive correlation with TG, TCh, FCh, apo A-I, apo A-II, apo B, and BMI (r = 0.93, 0.26, 0.42, 0.11, 0.35, 0.58, and 0.20, respectively; p < 0.0001 to 0.05), and an inverse correlation with HDL (r = -0.32; p < 0.01). P1 values in obese men (mean +/- SD: 139.2 +/- 98.2 micrograms/L) were significantly higher than those in normal (90.3 +/- 57.1) and lean ones (65.6 +/- 40.8) (p < 0.01). In both diabetic and atherosclerotic patients, P1 serum levels did not significantly differ from those in healthy subjects. From these results, we conclude the following: (1) the serum levels of P1 correlate significantly with those of lipids and lipoproteins; (2) P1 serum levels increase in the case of obesity.

Arteriosclerosis↗

PubMed1996

[Exacerbation of idiopathic interstitial pneumonia after lobectomy for lung cancer].

A 51-year-old man was found to have cancer in the left lung during treatment for idiopathic interstitial pneumonia. He underwent a left upper lobectomy because pulmonary function was judged to be adequate and because the interstitial pneumonia was not severe. After the operation, acute exacerbation of interstitial pneumonia occurred, and respiratory failure developed. Immediate steroid therapy alleviated his condition. Acute exacerbations of idiopathic interstitial pneumonia after pulmonary resection are usually fatal, and cases such as this are very rare.

Disease Progression↗

PubMed1996

[A case of bronchogenic carcinoma associated with pulmonary infarction which showed a tumorous shadow].

The patient was 69-year-old male with bronchogenic carcinoma associated with another abnormal shadow in the same left lower lobe. Its shadow was considered whether obstructive pneumonia or intrapulmonary metastasis before thoracotomy. Pathological examination revealed that this lesion was pulmonary infarction. It may be rare that bronchogenic carcinoma is associated with pulmonary infarction showing tumorous shadow. The staging and operative indication of lung cancer should be carefully determined which associate with abnormal shadow on the same lung field.

Aged↗

PubMed1996

[A case of tracheal stenosis caused by invasion of recurrent lung cancer palliated with dumon stent after Nd-YAG laser and bouginage using of tracheal tube].

The patient was 67 year-old male with tracheal stenosis caused by invasion of recurrent lung cancer after right upper sleeve lobectomy. He visited to our hospital for the purpose of palliation with tracheal stent. But rigid bronchoscope cannot be passed through its lesion because of severe stenosis. So the bouginage was performed. This method was that tracheal tube was inserted into his trachea through the hole of tracheotomy during six days following Nd-YAG laser therapy. After this treatment, rigid bronchoscope was inserted into the trachea and Dumon stent was placed safely and easily. It seems to be an useful palliation for patients with severs invasive tracheal stenosis.

Aged↗

PubMed1996

[Intrathoracic transposition of the muscle flap of the trapezius and rhomboideus in treating empyema].

Intrathoracic transposition of the muscle flaps of the trapezius and rhomboideus was performed simultaneously with an open-drainage thoracotomy in a 66-year-old male with empyema. These muscle flaps obliterated the upper empyema cavity and subsequently made it easier for obliteration the remaining lower empyema cavity. The muscle flaps of the trapezius and rhomboideus are useful in obliteration the upper empyema cavity.

Aged↗

PubMed1996

[Squamous cell carcinoma of the lung associated with palmo-plantar hyperkeratosis].

Palmo-plantar hyperkeratosis (PPH) is a diffuse keratoderma of the palms and soles that has been reported to be associated with internal malignancies such as lung and esophageal carcinomas. When PPH is associated with malignancy the prognosis is poor. The present patient was a 48-year-old man with PPH who suffered from squamous cell carcinoma of the lung. The pathological stage was T4N2M1 and the patient died of recurrent tumor 17 months after surgery. Because the prognosis of lung carcinoma associated with PPH is poor, patients with these conditions should undergo frequent medical examinations, which should include chest radiography and cytologic examination of sputum.

Carcinoma, Squamous Cell↗

PubMed1996

[Use of an expandable metallic stent in patients with superior vena cava syndrome--comparison of angiographic findings and autopsy findings].

To evaluate the usefulness of expandable metallic stens (EMS) in patients with superior vena cava (SVC) syndrome, we compared venographic findings obtained before EMS insertion with findings at autopsy. Stents were inserted into the SVC in 10 patients. An autopsy was done in 7 of the 10 patients. At autopsy, the lumen of the SVC was patent in 4 patients; in those 4 patients venography before EMS insertion showed that the SVC was obstructed by extramural compression. These results suggest that extramural compression without direct invasion of the tumor is the best indication for insertion of an EMS. At autopsy, the lumen of the SVC was obstructed by direct invasion of a tumor in 2 patients; in those 2 patients venography showed wall irregularity and lumen narrowing caused by tumor invasion. However, in those 1 patients SVC syndrome either did not recur or recurred in only a mild form after EMS insertion. The results in these 2 patients suggest that if collateral circulation does not develop, insertion of an EMS is indicated also in patients in whom the SVC is obstructed by direct invasion of a tumor. In the remaining patient, the lumen of the SVC was found at autopsy to be obstructed by a thrombus. SVC syndrome developed in this patient 430 days after EMS insertion. In 1 of the 7 patients, an EMS was inserted into the left innominate vein and also into the SVC. Venography before EMS insertion showed that the vein was obstructed by extramural compression without direct invasion of the tumor, but the EMS was found at autopsy to be completely obstructed by a thrombus. This suggests that insertion of an EMS into the left innominate vein is not indicated this vein is easily obstructed by thrombi because of its anatomical location.

Adult↗

PubMed1996

[Recurrence of a stage I thymoma after resection].

A 61-year-old man had a non-invasive thymoma. The tumor recurred in the aortocaval groove 6 months after thymothymectomy. The second tumor was a non-invasive, lymphocytic thymoma with polygonal cells, and was similar to the first one. The tumor may have been a multicentric thymoma, with malignant cells remaining in thymic tissue behind the brachiocephalic veins. To resect thymomas, extended thymectomy should be done to prevent recurrence from the remaining thymic tissue. CT scans should be obtained for long-term follow up after surgery, to detect any recurrence in its early stage.

Follow-Up Studies↗

PubMed1996

[Postoperative changes of maximum inspiratory and expiratory pressures in 3 pneumonia cases occurring after surgery for empyema].

We examined preoperative and postoperative maximum inspiratory (MIP) and expiratory (MEP) pressures in 3 cases who died of postoperative pneumonia occurring more than one month after open drainage thoracotomy for empyema. All cases showed reduction of MIP and MEP to less than 20 cmH2O one month after surgery, then suffered of pneumonia. On the other hand, the other 3 cases with empyema who underwent open drainage thoracotomy and recovered without complication showed recovery of MIP and MEP one month after surgery. In conclusion, for the cases that underwent thoracic surgery, postoperative MIP and MEP are the index of respiratory condition such as deep diaphragmatic breathing and ability of efficient coughing, and can be an early prediction of late onset pneumonia after thoracic surgery.

Aged↗

PubMed1995

Molecular cloning of CDK7-associated human MAT1, a cyclin-dependent kinase-activating kinase (CAK) assembly factor.

Mammalian CDK7 is a protein kinase identified as the catalytic subunit of cyclin-dependent kinase (CDK)-activating kinase and as an essential component of the transcription factor TFIIH that is involved in transcription initiation and DNA repair. We have identified in human cells a number of CDK7-associated cellular proteins that appear to fall into two classes based on their relative [35S] metabolic labeling intensity. One class of proteins present in CDK7 immunocomplexes as a minor fraction contains components of the TFIIH transcription complex such as p62 and p89ERCC3, whereas the other fraction contains four polypeptides (p35, p37Cyclin H, p75, and p95) that are stoichiometrically associated with CDK7. Whereas the levels of association of p35, p37Cyclin H, and p75 with CDK7 remain unchanged between density-arrested and proliferating Ewing sarcoma EW-1 cells, the association of p95 with CDK7 was significantly decreased as cells reached confluency. Through a large-scale immunopurification of CDK7 complexes and protein microsequencing, we have isolated a cDNA that encodes p35 and have shown that it is the human homologue of Mat1 that is involved in the assembly of CAK. MAT1 contains a highly conserved C3HC4 motif at its NH2 terminus, a characteristic feature shared among RING finger proteins. The human MAT1 gene expresses a single 1.6-kb transcript, the steady-state level of which, like CDK7 and cyclin H, varies significantly in different cell lines and in different terminally differentiated tissues.

Amino Acid Sequence↗

PubMed1995

The multidomain structure of Orc1p reveals similarity to regulators of DNA replication and transcriptional silencing.

The origin recognition complex (ORC) is a six protein assembly that binds S. cerevisiae origins of replication and directs DNA replication throughout the genome and transcriptional silencing at the yeast mating-type loci. Here we report the cloning of the genes encoding the 120 kDa (ORC1), 62 kDa (ORC3), and 56 kDa (ORC4) subunits of ORC and the reconstitution of the complete complex after expression of all six subunits in insect cells. Orc1p is related to Cdc6p and Cdc18p, which regulate DNA replication and mitosis, and to Sir3p, a regulator of transcriptional silencing. The N-terminal region of Orc1p is highly related to Sir3p, and studies of Orc1p/Sir3p chimeric proteins indicate that this domain is dedicated to the transcriptional silencing function of ORC.

Amino Acid Sequence↗

PubMed1995

Cloning, expression, and function of TFC5, the gene encoding the B" component of the Saccharomyces cerevisiae RNA polymerase III transcription factor TFIIIB.

TFC5, the unique and essential gene encoding the B" component of the Saccharomyces cerevisiae RNA polymerase III transcription factor (TF)IIIB has been cloned. It encodes a 594-amino acid protein (67,688 Da). Escherichia coli-produced B" has been used to reconstitute entirely recombinant TFIIIB that is fully functional for TFIIIC-directed, as well as TATA box-dependent, DNA binding and transcription. The DNase I footprints of entirely recombinant TFIIIB, composed of B", the 67-kDa Brf, and TATA box-binding protein, and TFIIIB reconstituted with natural B" are indistinguishable. A truncated form of B" lacking 39 N-terminal and 107 C-terminal amino acids is also functional for transcription.

Amino Acid Sequence↗

PubMed1995

p19Skp1 and p45Skp2 are essential elements of the cyclin A-CDK2 S phase kinase.

In normal human fibroblasts, cyclin A-CDK2 exists in a quaternary complex that contains p21 and PCNA. In many transformed cells, p21 disappears, and a substantial fraction of cyclin A-CDK2 complexes with p9CKS1/CKS2, p19, and p45. To investigate the significance of these rearrangements, we have isolated cDNAs encoding p19 and p45. In vitro reconstitution demonstrated that binding of p19 to cyclin A-CDK2 requires p45. Addition of these proteins to the kinase had no substantial effect on the kinase activity in vitro. Interference with p45 function in vivo by microinjection of antibodies or antisense oligonucleotides prevented entry into S phase in both normal and transformed cells. Cyclin A-CDK2 has previously been identified as a kinase whose activity is essential for S phase. Our results identify p45 as an essential element of this activity. The abundance of p45 is greatly increased in many transformed cells. This could result in changes in cell cycle control that contribute to the process of cellular transformation.

Amino Acid Sequence↗

PubMed1995

The p150 and p60 subunits of chromatin assembly factor I: a molecular link between newly synthesized histones and DNA replication.

Chromatin assembly factor I (CAF-I) from human cell nuclei is a three-subunit protein complex that assembles histone octamers onto replicating DNA in a cell-free system. Sequences of cDNAs encoding the two largest CAF-I subunits reveal that the p150 protein contains large clusters of charged residues, whereas p60 contains WD repeats. p150 and p60 directly interact and are both required for DNA replication-dependent assembly of nucleosomes. Deletion of the p60-binding domain from the p150 protein prevents chromatin assembly. p150 and p60 form complexes with newly synthesized histones H3 and acetylated H4 in human cell extracts, suggesting that such complexes are intermediates between histone synthesis and assembly onto replicating DNA.

Amino Acid Sequence↗

PubMed1995

Purification of Tetrahymena telomerase and cloning of genes encoding the two protein components of the enzyme.

Telomerase is a ribonucleoprotein DNA polymerase that catalyzes the de novo synthesis of telomeric simple sequence repeats. We describe the purification of telomerase and the cloning of cDNAs encoding two protein subunits from the ciliate Tetrahymena. Two proteins of 80 and 95 kDa copurified and coimmunoprecipitated with telomerase activity and the previously identified Tetrahymena telomerase RNA. The p95 subunit specifically cross-linked to a radiolabeled telomeric DNA primer, while the p80 subunit specifically bound to radiolabeled telomerase RNA. At the primary sequence level, the two telomerase proteins share only limited homologies with other polymerases and polymerase accessory factors.

Amino Acid Sequence↗

PubMed1995

Mammalian 60-kDa stress protein (chaperonin homolog). Identification, biochemical properties, and localization.

Mammalian chaperonin homolog (HSP60) was purified from porcine livers cytosol using a tandem ATP-Sepharose column and Mono Q column chromatography. A partial amino acid sequence (96 amino acid residues) of this protein was determined and coincided with those of human HSP60 with 96.9% homology, which was deduced from the nucleotide sequence of the cDNA. The sequence of the NH2 termini of the purified protein (5 amino acid residues) coincided with the signal sequence of HSP60. These facts led to the identification of the 60-kDa liver protein with the chaperonin homolog. Dihydrofolate reductase was able to form a stable complex with the liver chaperonin homolog. The liver chaperonin homolog was detected by at least five spots around pI = 5.6 on two-dimensional gel electrophoresis. Immunoblotting studies using an antibody against chaperonin homolog showed that the chaperonin homolog was localized in the cytosol, mitochondrial, and nuclear fractions of porcine liver. The chaperonin homolog was localized both in the mitochondria and cytoplasm of rat kidneys at the electron microscopic level. The chaperonin homolog in the cytosol, but not in the other subcellular fractions, was cross-reacted with an antibody against the synthetic peptide corresponding to the signal peptide of HSP60 as well as the purified chaperonin homolog on immunoblotting. These results suggested that the functional chaperonin homolog in the cytosol may be transported into the mitochondria and the protein may be processed to mitochondrial HSP60 in the organella.

Amino Acid Sequence↗

PubMed1995

A TBP-TAF complex required for transcription of human snRNA genes by RNA polymerase II and III.

The TATA-box-binding protein TBP exists in the cell complexed with different sets of TBP-associated factors (TAFs). In general, each of these TBP-TAF complexes is dedicated to transcription by a single RNA polymerase. Thus, SL1, TFIID and TFIIIB are required for transcription by polymerases I, II and III, respectively. Here we characterize a fourth TBP-TAF complex called SNAPc. Unlike the other TBP-TAF complexes, SNAPc is implicated in transcription by two types of polymerases; it is required for transcription of both the RNA polymerase II and III small-nuclear RNA genes and binds specifically to the proximal sequence element PSE, a non-TATA-box basal promoter element common to these two types of genes. In addition to TBP, SNAPc is composed of at least three TAFs, SNAP43, SNAP45 and SNAP50. The predicted amino-acid sequence of SNAP43 reveals that it corresponds to a new protein.

Amino Acid Sequence↗