Search PubMed⌕ Search

Biomedical subjects

Y Nonaka

Publications and source records attributed to Y Nonaka.

119 records · Page 7Linked to original sources
PubMedDate not supplied

IR and Raman spectroscopic studies on coulombic interaction between water-soluble porphyrins and nucleic acids.

We have shown previously that the N-methylpyridyl group vibrations of water-soluble porphyrins, M(TMpy-P4), are shifted to lower frequencies (0.5-2.6 cm-1) as a result of coulombic interaction between the N(+)-CH3 group of M(TMpy-P4) and the PO2 group of a nucleic acid. We have now turned over our attention to the effect of this coulombic interaction on the PO2 group vibrations of nucleic acids. Using Fourier transform ir and Raman spectroscopy, we found that the va(PO2) at 1221 cm-1 is shifted 12 approximately 17 cm-1 to higher frequencies, whereas the vs(PO2) at 1087 cm-1 is shifted 18 approximately 26 cm-1 to lower frequencies, when DNA is mixed with M(TMpy-P4). These results indicate that the N(+)-CH3 group of M(TMpy-P4) interacts preferentially with one of the two oxygen atoms of the PO2 group of the DNA duplex.

DNA↗
PubMedDate not supplied

Low-dosage intravenous immunoglobulin in the management of a patient with acquired von Willebrand syndrome associated with monoclonal gammopathy of undetermined significance.

We report herein the case of a 69-year-old Japanese man with acquired von Willebrand syndrome associated with monoclonal gammopathy of undetermined significance who developed IgG1-kappa antibodies against von Willebrand factor (VWF). The patient was urged to undergo tooth extractions because of alveolar pyorrhea, and a low-dosage intravenous immunoglobulin (IV-Ig) therapy (0.3 g of IgG/kg/day for 3 days) was chosen for him. On the 4th day after the infusion, VWF antigen and VWF ristocetin cofactor increased to 40 and 78% of the control, respectively, and dental extractions were performed successfully. On the 7th day, these values reached a maximum, i.e. 95 and 160% of the control, respectively. Then, they quickly decreased to 35 and 75% on the 10th day, and 6 months later, they became 16 and <3% of the control, respectively. Upon analysis of plasma VWF multimers (VWFMs) in this patient, those with large to medium molecular masses more selectively disappeared before the IV-Ig infusion than did those with small molecular masses. On the 4th day, the pattern of VWFMs was completely normalized and appeared to persist until the 10th day. Six months later, a small amount of large to medium-sized VWFMs was still present, but at 7-8 months, the pattern of VWFMs became almost the same as that before infusion. Throughout the patient's clinical course, the activity of plasma VWF-cleaving protease, which specifically cleaves the Tyr842-Met843 bond of the subunit and reduces its multimeric sizes, was quite normal (95-119%). These results provided consistent evidence that the selective absence of VWFMs with large to medium molecular masses in this patient is caused by the heightened clearance of a complex of IgG inhibitor and VWFMs from the circulation, presumably through IgG binding to the Fc receptor of macrophages. Furthermore, these results also indicated that a low-dosage IV-Ig therapy is effective enough for hemostatic management for programmed surgery.

ADAM Proteins↗
PubMedDate not supplied

Metabolism of 11-deoxycortisol by cytochrome P450(11 beta): identification of reaction products by 1H-NMR and LC/MS-APCI method.

A hitherto-unidentified steroid produced in the reaction mixture of 11-deoxycortisol with bovine cytochrome P450(11 beta) reconstitution system was purified by repeated HPLCs, and subjected to 1H-NMR analysis. The result suggested that the new metabolite was 19-oxo-11-deoxycortisol. This was further confirmed by a new analytical technique using LC/MS equipped with atmospheric pressure chemical ion (APCI)-analyzer.

Atmospheric Pressure↗
PubMedDate not supplied

Implication of ZOG protein (zona glomerulosa-specific protein) in zone development of the adrenal cortex.

The three zones of adrenal cortex are thought to arise from a single multipotential stem cell. Immunohistochemical studies of fetal and adult adrenals using an antibody against a previously-cloned ZOG protein, a rat homolog of Pref-1, were conducted to explore its roles in the differentiation of cortical tissues. At the early embryonic stage, ZOG was already expressed in adrenogonadal primordial cells. The ZOG-positive cells gradually formed the adrenal primordium by E14.5. By E17.5 the expression was repressed in the inner part of the aggregate and these cells began to express CYP11B1. The ZOG-positive cells at this stage existed at the periphery of the aggregate but they did not express CYP11B2 yet. Not until E20.5 did the aldosteronogenic cells appear among the ZOG-positive cells at the outermost part of the gland. Based on these and the other findings the zonal development of the adrenal cortex is discussed.

Adrenal Cortex↗
PubMedDate not supplied

Amino acid residues in I- and K-helices of rat CYP11B1 and CYP11B2 are important in expression of 18-hydroxylation activity.

When a peptide of the 316-398th amino acid residues in CYP11B1 was inserted to the corresponding site in CYP11B2, the 18-hydroxylation activity of the chimera decreased to a level similar to that of CYP11B2. Site-directed mutagenesis studies indicated that this alteration in the activity was due to the change of one amino acid, Ser321-->Pro, which is present at the C-terminal side of enzyme's I-helix. Conversely, when the corresponding region of CYP11B2 was changed to that of CYP11B1, the 18-hydroxylation activity increased to the similar level as that of CYP11B1. This elevation of the activity seemed to be due to the exchange of two amino acid residues; one, the 321st residue and the other, the 381st located in the K-helix. The results are discussed in comparison with those obtained by the human isozymes.

Amino Acid Sequence↗
PubMedDate not supplied

Metachronous liver metastasis of colorectal cancer: timing of occurrence and efficacy of adjuvant portal chemotherapy.

We estimated the time of occurrence of metachronous liver metastasis in colorectal cancer patients from tumor diameter and doubling time. Micro-metastasis was present prior to operation in most patients and a few metastatic cases could have been initiated by the surgical procedure. Portal chemotherapy is more effective against liver metastasis than intravenous infusion because a higher drug concentration in the liver can be obtained. This efficacy of portal chemotherapy on survival was also observed in a rat model. Thus perioperative adjuvant treatment should be undertaken for metastasis which already existed before the operation and adjuvant chemotherapy via portal vein is the treatment of choice. The no touch isolation technique is also needed to avoid spreading of tumor cells during surgery.

Animals↗
PubMedDate not supplied

Colorectal cancer after irradiation for cervical cancer--case reports.

Three patients with colorectal cancer after irradiation for cervical cancer are described. One patient had two colorectal cancers. Three of the four cancers in these patients were located in the rectum and one in the sigmoid colon; all were within the irradiation field. Microscopic radiation proctocolitis was observed in all specimens. The interval between irradiation and the diagnosis of colorectal cancer was 20-24 years. It is important to consider patients who have undergone pelvic irradiation as being in a high risk group for the development of colorectal cancer. Close and long-term surveillance may be useful in these patients.

Adenocarcinoma↗
PubMedDate not supplied

Anti-proliferative effect of combined tumour necrosis factor-alpha and interferon-alpha on human pancreatic cancer in vitro and in vivo.

The anti-proliferative effects of tumour necrosis factor-alpha (TNF-alpha) and interferon-alpha (IFN-alpha), alone or in combination, on human pancreatic cancer cells lines (PANC-1, MIA PaCa-2 and BxPC-3) and human pancreatic cancer tumour (Exp-58), were investigated in vitro and in vivo. The anti-proliferative effect was determined using the dye uptake method and the subcutaneous tumour model. Combined TNF-alpha and IFN-alpha demonstrated marked synergistic and/or additive effects in comparison with their effects as single agents. These results suggest that combined cytokine therapy of TNF-alpha and IFN-alpha may make possible some improvement in the treatment of pancreatic carcinoma patients in the future.

Animals↗