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T Kubota

Publications and source records attributed to T Kubota.

At least 127 records · Page 7Linked to original sources
PubMed2001

Lewis and Secretor gene effects on Lewis antigen and postnatal development of Lewis blood type.

Lewis (Le) and Secretor (Se) gene effects on postnatal change in Lewis antigens are described based on the quantitative analysis of Lewis antigens in blood. Genuine Lewis blood types were determined by Le and Se genotyping in DNA samples obtained from umbilical cord blood and infant blood. Lewis(a) (Le(a)) and Lewis(b) (Le(b)) antigen levels were measured by a time-resolved fluoroimmunoassay. We found that Lewis phenotypes in infants over 9 months of age agreed with the genuine types. In cord blood, the dosage effect of the Se gene on antigen levels was observed, but the Le gene effect was not observed. Both Se and Le gene effects were observed in newborn babies' blood 3-6 days after birth.

Aging↗
PubMed2001

Expression of Bcl-2 family reduces apoptotic hepatocytes after excessive hepatectomy.

Excessive hepatectomy often causes fatal hepatic failure, but the mechanism is unknown. We used a novel protocol of partial 90 and 95% hepatectomy (PHx) to investigate this mechanism in 2 groups of rats. The 90% PHx rats survived, but the 95% PHx animals died of hepatic failure. In the latter, cytokine (interleukin-6, tumor necrosis factor-alpha) levels and the apoptotic hepatocyte count increased, and there were few mitotic cells. By contrast, in the 90% PHx rats, the mitotic cell count increased, and more anti-apoptotic Bcl-xL protein was expressed. These results demonstrate that expression of Bcl-xL protein as an anti-apoptotic factor or regeneration factor contributes to survival after 90% PHx. Using an adenovirus vector, the human bcl-2 gene (hbcl-2) was therefore transfected to DA rat livers where it was efficiently expressed, and then 95% PHx was performed. Liver damage was decreased and the apoptotic cell count decreased too, but the rats died. We concluded that transfection of the hbcl-2 gene partly prevents cytotoxicity (apoptosis), but cannot ensure survival. Thus, some other factor is required (e.g., a regeneration stimulator) to maintain life in these models.

Animals↗
PubMed2001

Dynamic DNA methylation change in the CpG island region of p15 during human myeloid development.

We examined the kenetics of p15 methylation and expression during myeloid development. We treated human cord blood CD34+ cells with either GM-CSF alone or in combination with stem cell factor and followed methylation at this locus using bisulfite genomic sequencing. CD34+ cells were found to be either fully methylated or completely unmethylated at 27 CpG dinucleotide sites in exon 1 and at 18 CpG sites in the promoter region of the p15 gene. A time-course study showed that the percentage of the allelic methylation of p15 CpG island increased to approximately 50% to 60% until 7 days after cytokine stimulation, then decreased to less than 10% after 21 days. The methylation was also observed in bone marrow CD34+ cells exposed to GM-CSF. p15 expression varied inversely with methylation. Expression was negligible or at low levels until 14 days, after which it increased substantially. The frequency of myeloid colony-forming cells in the progeny decreased and myeloid-specific markers increased in the later stages. Based on our observations on cells grown with GM-CSF and 5-aza-2'-deoxycytidine, DNA methylation of the p15 promoter region CpG island appears to be associated with proliferation rather than differentiation of normal human myeloid progenitors.

Alleles↗
PubMed2001

Identification of heme oxygenase in human endometrium.

The aim of the present study was to investigate the presence of heme oxygenase (HO)-1 and HO-2 in human endometrium at various stages of the menstrual cycle using RT-PCR, Western blotting, and immunohistochemistry. RT-PCR detected mRNA for HO-1 and HO-2 in human endometrium at all stages of the menstrual cycle. Western blotting also revealed the expression of the two distinct HO proteins throughout the menstrual cycle. HO-1 was constitutively expressed, whereas HO-2 expression was apparently greater in the secretory phase than in the menstrual and proliferative phases. Immunohistochemistry showed that distribution of the two HO isoforms had distinct topographic patterns: HO-1 was observed in endometrial epithelial cells and macrophages, whereas HO-2 was found in endothelial cells and smooth muscle cells of blood vessels in the endometrium. The detection of mRNA and protein for HO-1 and HO-2 in normal human endometrium suggests that the carbon monoxide/HO system may play a role in the local control of endometrial function.

Antigens, CD↗
PubMed2001

Biosynthetic study of amphidinolide B.

The biosynthetic origins of amphidinoide B (1) were investigated on the basis of 13C-NMR data of 13C-enriched samples obtained by feeding experiments with [1-(13)C], [2-(13)C], and [1,2-(13)C2] sodium acetates in cultures of a dinoflagellate Amphidinium sp. These incorporation patterns suggested that 1 was generated from three successive polyketide chains, an isolated C1 unit from C-2 of acetates, six branched C1 units from C-2 of acetates, and an "m-m" and an "m-m-m" unit derived only from C-2 of acetates. The labeling patterns of amphidinolide B (1) were different from those of amphidinolide H (2), a 26-membered macrolide closely related to 1.

Acetates↗
PubMed2001

A serodiagnostic ELISA using recombinant antigen of swine transmissible gastroenteritis virus nucleoprotein.

A serodiagnostic ELISA utilizing the recombinant nucleoprotein (rN protein) of transmissible gastroenteritis virus (TGEV) was developed, and evaluated by examining a panel of 141 virus neutralization (VN) positive and 101 negative sera. The rN protein-based ELISA (rnELISA) appeared to be highly sensitive and specific (98.6% and 98.0%, respectively) when it was compared to the VN test. The result was similar to that of an ELISA based on purified viral antigens with showing good correlation (R=0.829). No cross-reaction was detected with antisera against porcine epidemic diarrhea virus, hog cholera virus, type A rotavirus, pseudorabies virus and swine vesicular disease virus in this ELISA. The rnELISA can be an alternative for the diagnosis of TGE with a great advantage in antigen preparation.

Animals↗
PubMed2001

Hyperintensity of posterior pituitary on MR T1WI in a boy with central diabetes insipidus caused by missense mutation of neurophysin II gene.

We present a 10-year old boy with central diabetes insipidus (CDI) showing hyperintensity in a normal-sized posterior pituitary on magnetic resonance (MR) T1-weighted image (T1WI). He complained of nocturnal enuresis and polyuria. Daily urine volume increased to 4 to 5 L, and AVP plasma level was very low. Polymerase chain reaction (PCR)-amplified exons of the arginine vasopressin (AVP)-neurophysin (NP) II gene were sequenced. Nucleotide-1884 guanine in Exon 2 was substituted with thymine, which induced a substitution of glycine for valine at amino acid position 65 in the NP II moiety. However, MR imaging showed hyperintensity in the posterior pituitary on T1WI. These results suggest that the MR findings of the posterior pituitary in CDI may vary.

Child↗
PubMed2001

Effects of nitric oxide on steroidogenesis in porcine granulosa cells during different stages of follicular development.

BACKGROUND: We have previously demonstrated that nitric oxide (NO) inhibits steroidogenesis via a cGMP-independent process, by inhibiting P450 aromatase activity in porcine granulosa cells (PGCs) derived from medium-sized (3--5 mm) ovarian follicles (M-PGC). OBJECTIVE: To determine whether the NO/NO synthase (NOS) system exerts any significant effects on steroidogenesis in PGCs derived from small follicles (<3 mm) (S-PGC) in comparison with those derived from medium follicles. DESIGN AND METHODS: PGCs, namely S-PGC and M-PGC, were incubated with the NO donor, NOC18, and a competitive blocker of NOS, N(3)-monomethyl-l-arginine (LNMMA), either alone or in the presence of FSH (200 ng/ml) or hCG (5 IU/ml). RESULTS: NOC18 significantly (P<0.01--0.001) suppressed basal (unstimulated) and gonadotropin-stimulated estradiol (E2) release from both S-PGC and M-PGC in a 2-h culture. NOC18 significantly (P<0.01--0.001) decreased basal and gonadotropin-stimulated progesterone release from S-PGC, but not from M-PGC. In addition, NOC18 significantly (P<0.05--0.001) inhibited aromatase activity in S-PGC. LNMMA had a significantly (P<0.01--0.001) stimulatory effect on the basal release of E2 and progesterone from M-PGC; however, it had no significant effect on basal steroidogenesis in S-PGC in a 24-h culture. In the presence of gonadotropin, LNMMA significantly (P<0.01--0.001) stimulated the release of E2 and progesterone from both S- and M-PGC, and this stimulatory effect was weaker in S-PGC than in M-PGC. These results demonstrate that NO inhibits E2 secretion by directly inhibiting the aromatase activity in S-PGC, as in M-PGC. It has been shown that the NO system suppresses the differentiation of S-PGC; however, the extent of suppression decreased with the progression of follicular growth. In addition, the activity of NOS in S-PGC was weaker than that in M-PGC. CONCLUSION: We strongly suggest that the NO/NOS system in PGC regulates steroidogenesis differently during different phase of follicular development.

Animals↗
PubMed2001

Hypocarbia in preterm infants with periventricular leukomalacia: the relation between hypocarbia and mechanical ventilation.

OBJECTIVE: The aim of this study was to elucidate the relationship between mechanical ventilation and hypocarbia in infants with periventricular leukomalacia (PVL). STUDY DESIGN: Matched pair analysis was conducted for 26 infants with PVL and 26 with normal development, who were born between 27 and 32 weeks' gestational age and required mechanical ventilation. The time-averaged carbon dioxide (CO(2)) index, PaCO(2), and pH were calculated every 24 hours for samples obtained from indwelling arterial catheters within the first 72 hours of life. The time-averaged respiratory rate of the ventilator (RR), peak inspiratory pressure (PIP), mean airway pressure (MAP), and ventilator index (VI) were also determined. The time-averaged total respiratory rate (TRR) was determined by observing the movement of the chest wall. The patients' characteristics, antenatal and neonatal variables, and electroencephalographic findings were also compared. RESULTS: The time-averaged CO(2) index was larger, the time-averaged CO(2) lower and the time-averaged pH higher in infants with PVL than in those with normal development on the third day of life. There was no significant difference in the time-averaged RR, PIP, MAP, or VI on any day. TRR was larger in the PVL group than in the control group on each day, but there was no significant difference. No significant difference was observed in the clinical characteristics or neonatal variables. Electroencephalographic abnormalities within 48 hours of life were more frequent in infants with PVL than in those with normal development. CONCLUSION: Hypocarbia was associated with PVL because the time-averaged CO(2) index was larger and the time-averaged PaCO(2) lower in infants with PVL than in those with normal development. However, the ventilator settings were similar among the infants with and without PVL.

Blood Gas Analysis↗
PubMed2001

Human uterine myometrial smooth muscle cell proliferation and vascular endothelial growth-factor production in response to platelet-derived growth factor.

It has been recognized that tissue-specific growth factors and angiogenic factors play important roles in the growth of tumors and in the tissue-repair system. In uterine myometrial smooth muscle cells, it has also been reported that the platelet-derived growth factor (PDGF) binds to PDGF receptors and stimulates proliferation. In this paper, we examine whether or not PDGF is able to stimulate production of vascular endothelial growth factor (VEGF) in cultured human myometrial smooth muscle cells. PDGF treatment enhanced immunoreactive VEGF production as well as cell proliferation. Production of VEGF121 and VEGF165 in the cells was detected by reverse transcription-polymerase chain reaction analysis, but the PDGF treatment did not change the ratio of VEGF165 to VEGF121. The effect of PDGF on cell proliferation leveled off at 10 ng/ml, whereas its effect on VEGF production continued to increase linearly at concentrations above 10 ng/ml. Upon treatment of the cells with antibody against VEGF, the cell proliferation increased linearly even at PDGF concentrations above 10 ng/ml. The enhanced [3H]thymidine incorporation by PDGF was abolished by either mitogen-activated protein kinase kinase (MAPKK) inhibitor or protein kinase C (PKC) inhibitor. In contrast, VEGF production was abolished by MAPKK inhibitor, but not by PKC inhibitor. These results indicate that PDGF stimulates both cell proliferation and VEGF production in partly different signal pathways, and thus PDGF might play a role in the physiology and pathology of the myometrium.

Adult↗
PubMed2001

Ca(2+)-dependent inhibition of inwardly rectifying K(+) channel in opossum kidney cells.

The effect of intracellular Ca(2+) on the activity of the inwardly rectifying ATP-regulated K(+) channel with an inward conductance of about 90 pS was examined by using the patch-clamp technique in opossum kidney proximal tubule (OKP) cells. The activity of the inwardly rectifying K(+) channel rapidly declined with an application of ionomycin (1 microM) in the presence of 10(-6) M Ca(2+) in cell-attached patches. The application of 10 microM phorbor-12-myristate-acetate (PMA) with 10(-6) M Ca(2+) reduced the K(+) channel activity. Although the channel activity was not influenced by an increase of bath Ca(2+) from 10(-7.5) to 10(-6) M, the activity was inhibited by protein kinase C (PKC, 1 U/ml) with 10(-6) M Ca(2+) in inside-out patches. The inhibitory effect of Ca(2+) with ionomycin on the channel activity was diminished by the pretreatment with a specific PKC inhibitor, GF 109203X (5 microM), in cell-attached patches. By contrast, the application of Ca(2+)/calmodulin kinase II (CaMK II, 300 pM) dramatically increased this channel activity in inside-out patches. In cell-attached patches, the addition of both GF 109203X and cyclospolin A (5 microM), a potent inhibitor of protein phosphatase 2B (calcineurin), instead stimulated the K(+) channel activity with ionomycin and 10(-6) M Ca(2+). The addition of protein phosphatase 2B (calcineurin) (2 U/ml) to the bath with calmodulin (1 microM) and Ni(2+) (10 microM) to stimulate calcineurin inhibited the channel activity in inside-out patches. Furthermore, the inhibitory effect of PKC or calcineurin on this channel activity was abolished by a removal of Ca(2+) from bath solution. These results suggest that Ca(2+)-dependent inhibitory effect on the inwardly rectifying K(+) channel in OKP cells was mainly mediated by Ca(2+)-PKC-mediated phosphorylation, and that the Ca(2+)-calmodulin-dependent phosphorylation process may be counterbalanced by the Ca(2+)-calmodulin-dependent dephosphorylation process.

Adenosine Triphosphate↗
PubMed2001

[A case of sarcoidosis characterized by a nasopharyngeal tumor and neurological lesions].

A 20-year-old man was admitted to a hospital complaining a slight fever lasting for 3 months associated with a dull headache and weight loss. A tumor was found in the nasopharynx of which biopsy specimen revealed granulomas with Langhans' giant cells. He was given antituberculous agents without symptomatic improvement, and transferred to our hospital. Serum levels of soluble IL-2 receptor and lysozyme were increased, and a significant uptake was observed by Ga scintigraphy at the nasopharynx and bilateral hilar lymphnodes. Furthermore, spinal fluid contained increased number of mononuclear cells, and T2-weighted MRI scans showed an enhanced lesion at the pituitary stalk. The specimen of both TBLB and repeated biopsy of the nasopharyngeal tumor showed granulomas without caseous necrosis. Taken together with these findings, a diagnosis of sarcoidosis with CNS involvement was finally made, and he made a favorable progress by treatment with prednisolone. This is an unique case which emphasizes importance of differential diagnosis of nasopharyngeal tumors with neurological manifestations in the clinicalsetting of rheumatology.

Adult↗
PubMed2001

Using contrast-enhanced sonography to assess the effectiveness of transcatheter arterial embolization for hepatocellular carcinoma.

OBJECTIVE: We evaluated the usefulness of contrast-enhanced wideband harmonic gray-scale sonography in assessing the therapeutic effects of transcatheter arterial embolization for patients with hepatocellular carcinoma and compared the findings of this imaging modality with those of helical CT. SUBJECTS AND METHODS: Twenty-nine patients with 39 hepatocellular carcinoma lesions were examined. We scanned lesions before and after therapy using contrast-enhanced wideband harmonic gray-scale sonography after injection of a galactose-palmitic acid contrast agent. All patients held their breath for 20--50 sec after injection while the vascularity of the tumor was observed. We then monitored tumor enhancement between 60 and 180 sec after injection with patients breath-holding for a few seconds. Lesions were considered to exhibit viable tumor residue if hypervascular enhancement was observed in the tumor. We compared this enhancement with helical CT findings. RESULTS: After therapy, 36 of the 39 lesions showed viable tumor residue on contrast-enhanced wideband harmonic gray-scale sonography, with no artifacts from iodized oil. Helical CT revealed a high-attenuation area in 12 of the 36 lesions, whereas 24 of the 36 lesions could not be evaluated for tumor residue as a result of artifacts from iodized oil accumulation in the tumor. The remaining three lesions showed complete deposition of iodized oil and complete necrosis on contrast-enhanced wideband harmonic gray-scale sonography. CONCLUSION: Contrast-enhanced wideband harmonic gray-scale sonography is useful in evaluating the therapeutic effects of transcatheter arterial embolization for hepatocellular carcinoma.

Aged↗
PubMed2001

Development of endoscopic surgery for the minimally invasive treatment of digestive and other diseases.

Minimally invasive surgery has rapidly changed the performance of surgical practice in a wide range of surgical specialities in the last decade of the 20th century. The marked progress in endoscopic surgery has been conducted especially in general and digestive surgery. The Department of Surgery, School of Medicine, Keio University has contributed to the development and establishment of endoscopic surgery in every subspeciality of general and digestive surgery. Our achievements include the development of original methods for laparoscopic wedge gastrectomy and endoscopic thyroidectomy, establishment of surgical techniques in endoscopic surgery for esophageal, gastric, colorectal and hepatobiliary diseases, and the introduction of robotics and tele-communicative technologies to endoscopic surgery.

Digestive System Surgical Procedures↗
PubMed2001

[5-fluorouracil and dihydropyrimidine dehydrogenase].

Dihydropyrimidine dehydrogenase (DPD) is the initial and rate-limiting enzyme in the (fluoro) pyrimidine catabolic pathway, and has an important role in 5-fluorouracil (5-FU) pharmacology. Some studies have demonstrated that the fluoropyrimidine catabolite may be related to the toxicity of 5-FU, and tumoral DPD prescribes the response to 5-FU-based therapy. By controlling DPD activity, a new class of fluorinated pyrimidines have been developed to minimize the variability of 5-FU pharmacodynamics, to decrease 5-FU toxicity, and improve its efficacy. Recently, these drugs, referred to as DIFs (DPD inhibitory fluoropyrimidines), have brought us to a new era of oral 5-FU therapy. The importance of DIF in 5-FU-based therapy is reviewed herein.

Antimetabolites, Antineoplastic↗