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Biomedical subjects

T Kubo

Publications and source records attributed to T Kubo.

At least 415 records · Page 23Linked to original sources
PubMed1997

Adenovirus vector-mediated gene transduction to chondrocytes: in vitro evaluation of therapeutic efficacy of transforming growth factor-beta 1 and heat shock protein 70 gene transduction.

OBJECTIVE: To investigate the effects of adenovirus vector-mediated gene transduction of E. coli beta-galactosidase (LacZ), transforming growth factor-beta 1 (TGF-beta 1), and heat shock protein 70 (HSP 70) on human chondrocyte-like cell line (HCS-2/8). METHODS: We examined expression of transduced genes and their expression periods by 5 bromo-4-chloroindolyl-beta-D-galactoside (X-gal) staining. Northern blotting, ELISA, and Western blotting. To assess the influence of TGF-beta 1 and HSP70 gene transduction, the expression of mRNA of type II collagen, proteoglycan core protein, matrix metalloproteinase 3 (MMP3) and tissue inhibitor of matrix metalloproteinase 1 were examined by Northern blotting. RESULTS: Staining with X-gal indicated that the genes were transduced into a majority of the cells. Expression of the transduced genes in the cells was continued for at least 21 days. Transduction of TGF-beta 1 gene enhanced mRNA expression of type II collagen and proteoglycan core protein, but suppressed MMP3 mRNA expression in the cells. Expression of HSP70 was also high. Enhanced expression of HSP70 elevated mRNA expression of proteoglycan core protein. CONCLUSION: These results indicate adenovirus vector is useful in chondrocyte gene therapy, and it could be an efficient mediator of TGF-beta 1 and HSP70 gene transduction.

Adenoviridae↗
PubMed1997

[Non-invasive determination of the quantity of pleural effusion and evaluation of the beneficial effect of pleuracentesis in patients with acute exacerbation of chronic congestive heart failure].

A non-invasive method to determine the quantity of pleural effusion and to evaluate the beneficial effect of pleuracentesis in patients with acute exacerbation of chronic congestive heart failure was evaluated. Twenty-three patients with pleural effusion due to acute exacerbation of chronic congestive heart failure were studied. The angle (x) formed by the diaphragm and lung (right side) or pericardium (left side) was measured by ultrasonography in the sitting position using the subscapular approach. Pleuracentesis was then performed in 15 patients, and the quantity of aspirated pleural effusion (y) was measured and compared with the angle x. There was significant relationship between y and x: y = 0.125 x 10(0.017x) (r = 0.77, p < 0.01). The 18 patients with more than 500 ml of estimated one-sided pleural effusion were divided into two groups; the nonpleuracentesis group (n = 8) and the pleuracentesis group (n = 10). The intravenous furosemide dose per increased body weight, and the term of oxygen supply and time to disappearance of edema were compared between the two groups. Intravenous furosemide dose was lower (p < 0.05) and the term of oxygen supply was shorter in the pleuracentesis group than in the nonpleuracentesis group (p < 0.05), whereas time to disappearance of edema was not significantly different. This non-invasive method can estimate the quantity of pleural effusion, and pleuracentesis had beneficial effect on patients with pleural effusion of greater than 500 ml (the angle x > 35 degrees ) in patients with acute exacerbation of chronic congestive heart failure.

Aged↗
PubMed1997

[Home enteral nutrition of patients with terminal cancer].

Generally hospitalization is regarded as a prerequisite for patients with cancer who require terminal care. Recently, special attention has been directed to home care for these patients from the standpoints of patients quality of life (QOL) and health economics. In the case of home care for patients with terminal cancer, effective pain control, careful nutrition administration, psychological care for the patient and his/her family members and emergency care are indispensable. Due to the number and extent of these requirements, home care for terminal patients is not yet common. We have been promoting the adoption of home enteral nutrition as a method to meet the nutritional needs of patients with terminal cancer. In this report, we discuss home enteral nutrition focusing on its indication and methodology, as well as related problems and nutrition administration in the future.

Adult↗
PubMed1997

Power spectral analysis of autonomic nervous activity in spontaneously hypertensive rats.

We studied power spectral analysis of heart rate variability (HRV) in control spontaneously hypertensive rats (SHR) and tourmaline hydroxyl negative ion-treated SHR groups. The power spectrum of HRV in SHR groups was composed of two frequency components; low frequency (LF, 0.005 approximately 1.0 Hz) and high frequency (HF, 1.0 approximately 2.0 Hz) components. The low frequency power (LFP) of HRV spectrum, which indicates sympathetic nervous activity, in negative air ion-treated SHR group was significantly (p < 0.01) smaller than in control SHR group. And also we obtained that the high frequency power (HFP) showing parasympathetic nervous activity in negative air ion-treated SHR group was significantly (p < 0.01) higher than in control SHR group. It could be concluded that hydroxyl negative air ions generated by tourmaline ionizer system decreased the elevated blood pressure, and control the sympathetic nervous activity and the parasympathetic nervous activity in SHR having the elevated blood pressure.

Air Ionization↗
PubMed1996

Inactivation of p16/CDKN2 and p15/MTS2 genes in different histological types and clinical stages of primary ovarian tumors.

To define the involvement of p16/CDKN2 and p15/MTS2 inactivation in ovarian tumorigenesis and the association of these inactivation events with histological types and clinical stages of ovarian tumors, we analyzed homozygous deletion and somatic mutation of p16/CDKN2 and p15/MTS2 genes, as well as hypermethylation of the 5'-CpG island of the p16/CDKN2 gene, in 49 primary ovarian tumors and 6 ovarian carcinoma cell lines. We found homozygous deletions of p16/CDKN2 and p15/MTS2 in 6 (12%) and 5 (10%) primary tumors, respectively. Somatic mutation of p16/CDKN2 was found in only 1 primary tumor, but mutation of p15/MTS2 was not detected in any sample. None of the 28 primary tumors or 6 cell lines was hypermethylated at the 5'-CpG island of p16/CDKN2. The incidence of inactivation of p16/CDKN2 in primary tumors was significantly higher in the advanced stages (7 of 29) than in the early stages (0 of 14). Seven of 9 alterations in p16/CDKN2 and p15/MTS2 were observed in serous (3 of 12), endometrioid (3 of 9) and clear-cell (1 of 4) carcinomas. However, only normal sequences of these genes were detected in mucinous carcinomas. Loss of heterozygosity (LOH) at the IFNA locus was detected in 1 of 19 (5%) tumors, but no change at the D9S171 locus was observed in 17 tumors. These results suggest that: (i) homozygous deletion is the main mechanism of inactivation of p16/CDKN2 and p15/MTS2 in ovarian tumorigenesis; (ii) inactivation of p16/CDKN2 and p15/MTS2 may be the histological type-specific events involved in ovarian tumorigenesis; and (iii) inactivation of p16/CDKN2 is potentially involved in the progression of ovarian tumors in advanced stages.

Carcinoma↗
PubMed1996

Signaling pathways and survival effects of BDNF and NT-3 on cultured cerebellar granule cells.

We investigated the signaling pathways exerted by brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) in relation to their survival-promoting effects on dissociated cultures of cerebellar granule cells prepared from postnatal 9-day-old rats. Granule neuron survival in culture was supported by BDNF, but not significantly by either nerve growth factor (NGF) or NT-3. BDNF and NT-3 resulted in not only the respective autophosphorylation of the Trk receptors, TrkB or TrkC, but also tyrosine phosphorylation of SHC, a protein involved in controlling p21ras activity, and phosphatidylinositol-3' (PI-3') kinase. NGF does not result in TrkA phosphorylation. In parallel, c-fos was induced within 30 min, in response to BDNF and NT-3. NT-3 induced the phosphorylation of these proteins to a lesser extent than BDNF. BDNF also induced the tyrosine phosphorylation of phospholipase C gamma (PLC gamma), but the NT-3-induced one was not detected. We postulate that no survival promotion by NT-3 is due to lesser level of trkC expression and of the NT-3-induced signaling in the cultured cerebellar granule neurons. Wortmannin, a specific inhibitor of PI-3' inhibited the BDNF effect on neuronal survival. PI-3' kinase-dependent pathways might be involved in the promotion of cerebellar granule cell survival by BDNF.

Adaptor Proteins, Signal Transducing↗
PubMed1996

Expression of cyclin A decreases during neuronal apoptosis in cultured rat cerebellar granule neurons.

Cultured cerebellar granule neurons died in an apoptotic manner when the K+ concentration in culture medium was lowered to the normal level (5 mM) after maturation of cells with a high concentration of K+ (26 mM). The changes in expression of 14 cell cycle-related genes in this CNS apoptosis model were analyzed by quantitative RT-PCR. Most of the genes analyzed were stable during apoptosis. The expression of cyclin A mRNA, however, transiently decreased 1 h after the induction of apoptosis, and recovered within 3 h to above the basal level. In this system, the level of cyclin D1, which has been reported to be up-regulated in apoptosis of NGF-deprived cultured sympathetic neurons, did not change. These results suggest that the molecular mechanisms in these two apoptosis models are different. To determine cyclin A protein level, we used an immunostaining method. The number of cyclin A-positive neurons decreased during apoptosis. Moreover, the numbers of MAP2- and cdk2-positive neurons also decreased in a similar manner. Taken together, these results suggest that there is a relationship between apoptosis and cell cycle, and that morphological changes during apoptosis result from cytoskeletal structure degradation.

Age Factors↗
PubMed1996

Oxygen-induced apoptosis in PC12 cells with special reference to the role of Bcl-2.

We previously reported that PC12h cells are killed by a high oxygen atmosphere. In this study, we further characterized this oxygen-induced cell death and found apoptotic features, as follows. Firstly, chromatin condensation was observed in cells cultured in a 50% O2 atmosphere. Secondly, cycloheximide and cordycepin, protein and RNA synthesis inhibitors, respectively, prevented the oxygen-induced cell death in PC12h cells, suggesting that it is mediated by an intracellular death program. Thirdly, NGF, CPT-cAMP and depolarization by high potassium medium also effectively inhibited this apoptotic cell death in PC12h cells. The effect of high K+ is thought to be mediated by the influx of Ca2+ into cells through voltage-dependent Ca2+ channels, because nifedipine, an L-type Ca2+ channel blocker, inhibited the effect of high K+. In addition, since the oxygen-induced apoptosis was blocked by the antioxidant vitamin E, this oxygen toxicity is suggested to be mediated by reactive oxygen species. To further characterize this oxygen-induced apoptosis at the molecular level, we used PC12 cells overexpressing the proto-oncogene bcl-2. Although a large number of PC12 cells transfected with the control vector died in a 50% O2 atmosphere within 6 days, bcl-2-transfected PC12 cells survived and proliferated. These findings suggested that our system using PC12 cells will be a useful model with which to analyze the molecular mechanisms of apoptosis induced by oxidative stress in neuronal cells.

Animals↗
PubMed1996

Prenatal monitoring in a family at high risk for ornithine transcarbamylase (OTC) deficiency: a new mutation of an A-to-C transversion in position +4 of intron 1 of the OTC gene that is likely to abolish enzyme activity.

DNA analysis of a male propositus with ornithine transcarbamylase (OTC) deficiency documented an A-to-C substitution in position +4 of intron 1. No other abnormalities were observed in the OTC gene, or at 563 bp upstream of the 5' site, which included a promoter region, or at 383 bp downstream of the termination codon, which included a polyadenylation signal sequence. This mutation produces an RsaI site in the sequence, which was used for prenatal monitoring in the fourth and fifth pregnancies. DNA from amniotic cells in the former case were positive for RsaI digestion and the SRY gene (sex determinant region Y), indicating hemizygosity for the mutant allele. OTC activity was not measurable, and mRNA of the OTC gene was not detected by Northern blotting in the affected fetal liver. RT-PCR (reverse transcription-PCR) demonstrated only the wild-type allele. Thus, the mutation interferes with RNA processing, and an extremely low amount of normally spliced mRNA for the OTC gene seems to have caused the disease in our patient. The fetus of the fifth pregnancy was a normal male, as confirmed postnatally.

Amino Acid Metabolism, Inborn Errors↗
PubMed1996

Purification, characterization, and cDNA cloning of a galactose-specific C-type lectin from Drosophila melanogaster.

We purified a lectin from a pupal extract of Drosophila melanogaster. This lectin agglutinated trypsinized and glutaraldehyde-fixed bovine red blood cells in the presence of calcium or magnesium. The hapten sugar of this lectin was galactose. The molecular mass of the intact lectin was determined to be 41 kDa, and it comprised 14- and 17-kDa subunits. The 17-kDa subunit was shown to be a glycosylated form of the 14-kDa subunit. Analysis of the cDNA for this lectin revealed that the 14-kDa subunit consists of 163 amino acid residues and contains all residues conserved in various C-type lectins. It was suggested that the Drosophila lectin and Sarcophaga lectin share some properties and function similarly in defense and development, but probably they are not structural homologues.

Amino Acid Sequence↗
PubMed1996

A duplicated sequence in sugarbeet mitochondrial transcripts is differentially edited: analysis of orfB and its derivative orf324 mRNAs.

RNA editing of the duplicated sequences was investigated in the transcripts of orfB and orf324 genes from sugarbeet mitochondria. The orf324 shares the first 59 bp of the reading frame and 321 bp upstream sequence with orfB. Two cytidine-to-uridine editing sites were found in orfB, but the corresponding cytidine residues remained unchanged in the transcripts of orf324. In the vicinity of the non-edited cytidine residues within the shared sequence element of orf324 were identified three point mutations that may abolish orf324 editing. Our results also suggest that selection of editing sites depends on primary sequence.

Amino Acid Sequence↗
PubMed1996

Purification and cDNA cloning of the alcohol dehydrogenase of the flesh fly Sarcophaga peregrina. A structural relationship between alcohol dehydrogenase and a 25-kDa protein.

We purified to homogeneity two proteins with molecular masses of 25 kDa from the fat body of the Sarcophaga larva. One was alcohol dehydrogenase (ADH) and the other was a 25-kDa protein of which the genomic DNA had been cloned. We isolated the cDNA for ADH and determined its amino acid sequence. Amino acid sequence identity between ADH and the 25-kDa protein was 40%, indicating that they are structurally related proteins. The amount of ADH in Sarcophaga was almost constant through the larval stage to the adult stage, but the 25-kDa protein was detected only within a restricted period between the final larval instar and the early pupal stage.

Alcohol Dehydrogenase↗
PubMed1996

Expression of heat-shock-proteins in the differentiation process of chondrocytes.

To know the role of HSP70 in chondrocytes, HSP70 expressions under heat stress or in a non-stress condition were examined by using electrophoresis, immunohistochemistry, and in situ hybridization. As a result, HSP70 was observed in proliferating chondrocytes in the micro-mass cultures without heat stress. In this culture, chondrocytes maintained the terminal differentiation potency. On the other hand, HSP70 did not appear in the chondrocytes in the logarithmic growth phase of the monolayer culture. In growth plates in vivo, HSP70 expressions in the chondrocytes located in the resting and hypertrophic zones were observed with immunohistochemistry. Appearance of HSP70 mRNA was also confirmed by in situ hybridization in the proliferating zone of growth plate. HSP70 can be expressed not only in chondrocytes under heat stress but also in the cells without stress, and the expression would be related to the terminal differentiation of chondrocytes. HSP70 is surmised to promote hypertrophy and calcification by stopping protein synthesis in chondrocytes which possess terminal differentiation potency.

Animals↗
PubMed1996

Spermatocyte-specific expression of the gene for mouse testis-specific transcription elongation factor S-II.

Previously, we characterized a rat cDNA for testis-specific transcription elongation factor S-II (SII-T1) (Q. Xu et al., J. Biol. Chem. 269, 3100-3103 (1994)). Here, we isolated a 335-bp fragment of the cDNA for mouse SII-T1, and used it to examine the expression of the SII-T1 gene in the testis by in situ hybridization. The results indicated that the SII-T1 gene is expressed exclusively in spermatocytes, showing no appreciable expression in spermatogonia, spermatids, or Leydig cells. RT-PCR experiments using testis RNA from W/Wv mutant mice also suggested that SII-T1 is a specific transcription elongation factor essential for spermatogenesis.

Amino Acid Sequence↗
PubMed1996

Molecular cloning of cDNA and analysis of expression of the gene for alpha-glucosidase from the hypopharyngeal gland of the honeybee Apis mellifera L.

Previously, we identified and purified an alpha-glucosidase with a molecular mass of 70 kDa from a homogenate of the hypopharyngeal gland of the older worker bee (forager bee) Apis mellifera L. (T. Kubo et al, J. Biochem., 1996, 119, 291-295). Here, we isolated and sequenced a cDNA for the alpha-glucosidase. The cDNA encoded a protein consisting of 650 amino acids, which had high sequence identity with fruit fly and mosquito possible maltase gene products. RT-PCR showed that the gene was expressed specifically in the hypopharyngeal gland of the forager bee.

Amino Acid Sequence↗
PubMed1996

Central nicotinic receptor blockade inhibits emotionally conditioned pressor responses in rats.

A conditioned stimulus previously paired with electric footshock produced an increase in blood pressure in conscious, freely moving rats. The conditioned pressor response was reproducible. Intracerebroventricular injection of the nicotinic receptor antagonists hexamethonium (1-10 micrograms) or pentolinium (10 micrograms) but not the muscarinic receptor antagonist methylatropine (3 micrograms) produced an inhibition of the conditioned pressor response, whereas intraarterial injection of hexamethonium (10 micrograms) did not affect the response. Intraventricular injection of the cholinesterase inhibitor physostigmine (3-10 micrograms) produced an enhancement of the conditioned pressor response. These results are consistent with the possibility that central nicotinic receptors play a role in the expression of the emotionally conditioned pressor response in rats.

Animals↗
PubMed1996

GABAergic inhibitory response of locus coeruleus neurons to caloric vestibular stimulation in rats.

We examined the effects of caloric vestibular stimulation on the neuronal activity of the locus coeruleus (LC) in urethane-anesthetized rats. The middle ear cavity was irrigated with hot (44 degrees C) or cold (30 degrees C) water through a polyethylene tube. Most neurons (hot water: 76%, 55/72; cold water: 90%, 19/21) exhibited suppression of neuronal discharge in response to caloric stimulation. The suppression of LC neuronal discharge following caloric stimulation occurred with a long latency (approximately 80 s), and lasted a long period of time (approximately 3 min). Neither caloric stimulation of the auricle, nor irrigation of the middle ear with water at 37 degrees C, nor caloric stimulation of the middle ear after labyrinthectomy inhibited LC neuronal discharge. The caloric stimulation-induced LC neuronal inhibition was significantly attenuated by the intravenous injection of picrotoxin and by the iontophoretic application of bicuculline methiodide. These findings indicate that the predominant effect of caloric vestibular stimulation on LC neuronal discharge is inhibitory, and that the caloric stimulation-induced LC neuronal inhibition is mediated by GABAA receptors located on the membrane of LC neurons. It is suggested that the suppressed activity of noradrenergic LC neurons is involved in the vestibulo-autonomic reflex.

Action Potentials↗