Search PubMed⌕ Search

Biomedical subjects

N Itoh

Publications and source records attributed to N Itoh.

At least 307 records · Page 17Linked to original sources

[A non-invasive portable blood-glucose monitoring system: sampling of suction effusion fluid].

We developed a new portable transcutaneous blood glucose monitoring system using non-invasive collection of suction effusion fluid (SEF) from human skin. A ion sensitive field effect transistor (ISFET) sensor was employed to measure glucose concentration in a very small quantity of the SEF. The system was composed of a couple of portions. One structure was a suction cell, and the other was a main frame. The suction cell included the ISFET glucose sensor, a dilution mechanism, and a sucking interface to human skin. The main frame contained a dilution solution reservoir, a liquid waste reservoir, a fluid pump, a vacuum pump, a micro processor, batteries, and a user interface. The system is self-contained for portable usage during up to 6 hrs monitoring. This system may be the first blood glucose monitoring equipment which does not use blood sampling.

Animals↗

Aromatase activity in an estrogen-producing adrenocortical carcinoma in a young man.

We report on a 19-year-old man with adrenocortical adenoma producing an excessive amount of estrogen. Determination of aromatase activity of the carcinoma tissue revealed its marked enhancement compared with that of 3 normal adrenal glands and the adipose tissue. The enhanced activity of aromatase was mainly responsible for the overproduction of estrogen in the adrenocortical carcinoma of our case.

Adrenal Cortex Neoplasms↗

Induction of differentiation of embryonal carcinoma F9 cells by iron chelators.

The effects of several chelators, including hinokitiol, on embryonal carcinoma F9 cell differentiation were assessed by assaying the production of plasminogen activator (PA) as a differentiation marker protein. Hinokitiol and tropolone which were potent differentiation inducers lost their activity following preincubation with Fe2+ and Fe3+ ions. Other metal ions had no or little effect on the hinokitiol-induced differentiation. Of several chelators examined, dithizone induced differentiation as effectively as did hinokitiol and tropolone. Dithizone-induced differentiation was also inhibited by preincubation with Fe3+ ions. It was concluded that some potent iron chelators could trigger the teratocarcinoma F9 cells to differentiate through the chelation with intracellular iron ions.

Animals↗

Isolation of OprM-deficient mutants of Pseudomonas aeruginosa by transposon insertion mutagenesis: evidence of involvement in multiple antibiotic resistance.

Overproduction of the Pseudomonas aeruginosa outer membrane protein OprM was observed in the nalidixix acid (NalB-type) multidrug-resistant strains. To clarify the involvement of OprM in the resistance, transposon mutants were isolated from strain PAO4141 and its OprM-overexpressed mutant KG2113 and were screened for OprM production by immunoblot assays using murine polyclonal antiserum resulting from immunization with purified OprM. Two OprM-deficient mutants from PAO4141 and one from KG2113 were identified. Determination of the susceptibilities of these mutants to antimicrobial agents demonstrated that OprM was involved not only in the acquired resistance, but also in the intrinsic resistance of P. aeruginosa to quinolones, cephems, penicillins, tetracycline, and chloramphenicol.

Bacterial Outer Membrane Proteins↗

Evidence for the location of OprM in the Pseudomonas aeruginosa outer membrane.

OprM with a M(r) of 49 K is associated with the multidrug resistance of Pseudomonas aeruginosa. Detergent fractionation of bacterial cells has demonstrated that OprM is located in the outer membrane from which it sediments with the other major outer membrane proteins. In this study we have determined the location of OprM as the P. aeruginosa outer membrane. Western immunoblots of cell fractions, obtained by sucrose density gradient centrifugation of whole cell lysates, were probed with an OprM-specific murine polyclonal antiserum.

Antibodies, Bacterial↗

Purification and characterization of a novel metal-containing nonheme bromoperoxidase from Pseudomonas putida.

A novel bromoperoxidase was purified to homogeneity from the bacterium Pseudomonas putida IF-3 strain, which produces the antibiotic pyrrolnitrin. The enzyme had a molecular mass of 68,000 and was composed of two identical subunits (33,000). It was specific for I- and Br- and inactive toward Cl- and F- in the monochlorodimedone assay system. The optimum pH of the enzyme was around 4.2 and it rapidly lost its activity below 3.5, but it was stable over of range pH of 4 to 11. The purified enzyme was activated several fold by incubation with only cobalt ions, and did not contain an organic prosthetic group such as heme, flavin and cobalamin. Analyses of prosthetic metal compounds in the enzyme using plasma atomic emission spectroscopy (ICP-AES) combined with mass-spectroscopy (MS) and trace metal determination by high performance liquid chromatography (HPLC)-spectrometry, revealed that the enzyme contained 0.35 +/- 0.1 mol of cobalt ions, 1.0 +/- 0.2 mol of nickel ions, 0.8 +/- 0.2 mol of zinc ions and 2.0 +/- 0.2 mol of ferric iron per mol of enzyme, assuming the molecular weight of 68,000. There was no trace of vanadium in the enzyme, unlike in some nonheme haloperoxidases. Thus the bromoperoxidase of P. putida is a novel nonheme metal-containing bromoperoxidase.

Amino Acid Sequence↗

Immunohistochemical study for basic fibroblast growth factor and fibroblast growth factor receptor I in pituitary adenomas.

Immunohistochemistry and RT-PCR of basic fibroblast growth factor (bFGF) and one of its receptors (FGFR-I) were performed in pituitary adenomas. Sixty percent of pituitary adenomas showed strong or moderate immunoreactivity to bFGF. The immunoreactivity for FGFR-I in tumor tissues showed positive correlation to that for bFGF (X2 = 6.176, P = 0.0456). Basic FGF-positive cells consisted of pituitary adenoma cells as well as folliculostellate cells and, their distribution was heterogeneous. Expressions of bFGF and FGFR-I were not related to cell proliferation of pituitary adenomas or hormones produced, suggesting that bFGF plays some role other than progression of pituitary adenomas.

Adenoma↗

Differential expression patterns of mRNAs for members of the fibroblast growth factor receptor family, FGFR-1-FGFR-4, in rat brain.

We have examined the region-specific expression of mRNAs for four members of rat FGF receptor family, FGFR-1, FGFR-2 FGFR-3, and FGFR-4, in rat brain by in situ hybridization. The FGFR-1, FGFR-2, and FGFR-3 mRNAs were expressed widely but differentially in the brain. However, the FGFR-4 mRNA was not expressed in the brain. The FGFR-1 mRNA was strongly expressed in several regions including the hippocampus, cerebellum, and pedunculopotine tegmental nucleus. The FGFR-2 mRNA expression was high in the choroid plexus, and moderate in the fiber-rich regions (the corpus callosum, external capsule, and internal capsule) and the olfactory bulb. The FGFR-3 mRNA was expressed diffusely in the brain. We have also examined the cellular localization of these mRNAs in the brain. Although the FGFR-1 mRNA was expressed preferentially in neurons, the FGFR-2 and FGFR-3 mRNAs were expressed preferentially in glial cells. The present findings that the FGFR-1, FGFR-2, and FGFR-3 mRNAs were expressed widely but with region- and cell-specificity in the brain indicate that these receptors have different roles in the brain.

Amino Acid Sequence↗

Gene organization and 5'-flanking region sequence of conglutinin: a C-type mammalian lectin containing a collagen-like domain.

Bovine conglutinin is a Ca(2+)-dependent serum lectin specific for N-acetylglucosamine. In the present study, we report the exon-intron organization and the sequence of 5'-regulatory region of the conglutinin gene. The coding region of conglutinin mRNA, which encoded the signal peptide and the sequence of the mature protein of 351 amino acids, consisted of seven exons. Exon III encoded the signal peptide, a cysteine-rich NH2-terminal region and six repeats of a Gly-X-Y triplet with one irregular triplet. The remaining long collagen-like domain (49 Gly-X-Y repeats with one irregular triplet) was encoded by four separate exons (Exon IV-VII). Exon VIII encoded the neck region and Exon IX encoded the carbohydrate-recognition domain. The overall exon-intron organization of conglutinin was very similar to that of mannan (mannose)-binding proteins. However, the presence of 108 bp exons in the gene encoding the collagen-like domain was a characteristic of conglutinin. In the promoter region of the gene, several putative consensus sequences that may be involved in the expression of conglutinin were identified.

Amino Acid Sequence↗

n-hexane-induced synthesis of hepatic metallothionein is mediated by IL-6 in mouse.

The mechanism of metallothionein (MT) synthesis in the liver by n-hexane (HX) was examined. The increased synthesis of MT in the liver by HX was inhibited by dexamethasone pretreatment. Serum IL-6 was increased soon after HX injection, reaching a maximum at 8-16 hr, and then decreased, but neither IL-1 nor TNF was increased. The hepatic MT concentration reached a maximum later than did the serum IL-6 concentration, at 2 days after administration. When the MT synthesis induced by HX was inhibited by dexamethasone pretreatment, the concentration of IL-6 in the serum was suppressed to a very low level. Furthermore, the increase in concentration of hepatic MT and plasma fibrinogen was significantly decreased by the anti-mouse IL-6 monoclonal antibody. The concentration of hepatic MT was higher when the concentration of HX in the olive oil of the solution for injection was higher, even when the amount of HX administered was the same. It is suggested that the cytokine(s) is produced by the macrophage and fibroblast through injury and inflammation at the site of administration. These findings suggest that MT synthesis resulting from HX is induced indirectly through cytokine(s) production, especially IL-6.

Animals↗

Successful pregnancy in a patient with endometrial carcinoma treated with medroxyprogesterone acetate.

A 32-year infertile Japanese woman suffered from endometrial cancer, which was treated with repeated endometrial curettage and medroxyprogesterone acetate for 6 months. The patient then became pregnant and was delivered of a live-born male infant at 37 weeks gestation by cesarean section for placenta previa. At cesarean section there were no abnormal findings in the uterine cavity or other pelvic organs.

Adenocarcinoma↗

Occurrence of IDDM during interferon therapy for chronic viral hepatitis.

We report a case of IDDM which occurred during interferon therapy for chronic hepatitis. A 31-year-old man intermittently received 2.5 x 10(8) units of alpha-IFN and 1 x 10(8) units of beta-IFN for treatment of chronic viral hepatitis type B. Four years after the beginning of IFN therapy, he acutely developed moderate hyperglycemia and severe ketonuria with positive islet cell antibody, and then 28 units/day of insulin injection was started. After the start of insulin therapy, there was a remission period for about 3 years but insulin-dependency recurred thereafter. The clinical course of this case indicates that IFN therapy precedes IDDM. During and after IFN therapy we should consider the possibility of occurrence of IDDM as well as other autoimmune diseases and observe the clinical course carefully.

Adult↗