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Biomedical subjects

M Itoh

Publications and source records attributed to M Itoh.

At least 523 records · Page 29Linked to original sources
PubMed1996

Brain 6-[18F]fluorodopa metabolism in early and late onset of Parkinson's disease studied by positron emission tomography.

We measured 6-[18F]fluorodopa (FDOPA) uptake in the caudate nucleus and the putamen of 20 patients with early and late onset of Parkinson's disease (EOPD and LOPD) and 20 normal control subjects using positron emission tomography. The mean influx rate constant values (Ki) were significantly reduced in the caudate nucleus and the putamen of the patients with EOPD and LOPD compared with age-matched control groups (p < 0.01), respectively. There were significant negative correlations between Ki values in the caudate nucleus (r = -0.67, p = 0.0024) and the putamen (r = -0.67, p = 0.0014), and duration of disease in the LOPD group compared with the EOPD group. Similar negative relationships between Ki values and clinical stages by Hoehn and Yahr and degrees of main clinical symptoms (bradykinesia, tremor and rigidity) were more markedly seen in the LOPD group than in the EOPD group. The present results suggest that the function of presynaptic dopaminergic terminals correlates well with clinical disease severity and degrees of main symptoms in the LOPD group, but not in the EOPD group. We speculate that compensatory up-regulatory function in the postsynaptic dopaminergic receptors may modify disease severity and the degrees of main clinical symptoms of EOPD.

Adult↗
PubMed1996

Morphological study of the brainstem in Fukuyama type congenital muscular dystrophy.

We have observed sudden clinical death due to Fukuyama-type congenital muscular dystrophy (FCMD). In FCMD, brain abnormalities, such as polymicrogyria, leptomeningeal neuroglial heterotopia and abnormal course of the corticospinal tracts, are well known. We investigated the brainstem of 10 FCMD and 7 control cases. Among the control cases, 5 with Duchenne type muscular dystrophy died of heart failure and 2 died accidental death. In the brainstem, the catecholaminergic neurons characterized by reaction with antiserum to tyrosin hydroxylase showed notable reduction in the reticular formation, vagal nuclei, and nucleus tractus solitarius. Delays or aberrations of neural control may contribute to the pathogenesis of sudden infant death syndrome, and medullary gliosis occurs in the reticular formation of sudden infant death syndrome. The pathogenesis of neurons in the brainstem in FCMD may be similar to that in sudden infant death syndrome. These findings suggest neuronal dysfunction in the brainstem and may be related to respiratory, circulatory, or sleep-wake regulation disorders.

Adolescent↗
PubMed1996

Complement plays an essential role in shock following intestinal ischaemia in rats.

Intestinal ischaemia lasting more than 30 min in rats causes fatal systemic shock. Systemic shock was suppressed by preadministration of cobra venom factor (CVF), which reduced the serum complement to less than 5% of the normal level, indicating that complement is involved in the syndrome. After complement activation, anaphylatoxins such as C3a and C5a are generated, and their activity is restricted by carboxypeptidases which remove C-terminal arginine from such bioactive peptides. As expected, preadministration of a carboxypeptidase inhibitor enhanced the systemic shock induced by the intestinal ischaemia. However, when the complement level was suppressed by CVF treatment, no fatal systemic shock was induced by the intestinal ischaemia even with preadministration of the carboxypeptidase inhibitor. These results indicate that complement plays a crucial role in systemic shock induced by intestinal ischaemia, and that anaphylatoxins generated by the complement activation should be involved in induction of the shock syndrome.

3-Mercaptopropionic Acid↗
PubMed1996

Decreased secretion of gonadotropins in a patient with Graves' disease.

A 56-year-old female with Graves' disease who presented with decreased secretion of gonadotropins is described. She was admitted to hospital because of her being in a state of confusion. One month before admission she had been diagnosed as having Graves' disease and was treated with methimazole since then. Plasma LH and FSH levels were undetectable, and their responses to LH-RH were extremely decreased in spite of undetectable levels of plasma estradiol and estriol. One year after treatment, both basal and stimulated values of LH and FSH reverted to normal as did those of TSH. Reversible suppression of gonadotropins as described herein has never been reported in cases of Graves' disease.

Antithyroid Agents↗
PubMed1996

Short stature due to growth hormone deficiency associated with Cushing's disease and ulcerative colitis.

We report a rare case of Cushing's disease associated with ulcerative colitis in a patient primarily treated with growth hormone due to short stature. At the age of fifteen years, the patient had a short stature due to GHD and was treated with the extracted GH for a short period. At the age of twenty-one years, his body weight gradually increased and, based on the results of several tests, he was diagnosed with Cushing's disease and GHD was observed in our patient. The excess secretion attenuation of pituitary hormones with reduced secretion periods as well as the relation between ulcerative colitis and elevated plasma cortisol concentrations is briefly discussed in this paper.

Adult↗
PubMed1996

Interspecies diversity of the occludin sequence: cDNA cloning of human, mouse, dog, and rat-kangaroo homologues.

Occludin has been identified from chick liver as a novel integral membrane protein localizing at tight junctions (Furuse, M., T. Hirase, M. Itoh, A. Nagafuchi, S. Yonemura, Sa. Tsukita, and Sh. Tsukita. 1993. J. Cell Biol. 123:1777-1788). To analyze and modulate the functions of tight junctions, it would be advantageous to know the mammalian homologues of occludin and their genes. Here we describe the nucleotide sequences of full length cDNAs encoding occludin of rat-kangaroo (potoroo), human, mouse, and dog. Rat-kangaroo occludin cDNA was prepared from RNA isolated from PtK2 cell culture, using a mAb against chicken occludin, whereas the others were amplified by polymerase chain reaction based on the sequence found around the human neuronal apoptosis inhibitory protein gene. The amino acid sequences of the three mammalian (human, murine, and canine) occludins were very closely related to each other (approximately 90% identity), whereas they diverged considerably from those of chicken and rat-kangaroo (approximately 50% identity). Implications of these data and novel experimental options in cell biological research are discussed.

Amino Acid Sequence↗
PubMed1996

Normal D-JH rearranged products of the IgH gene in SCID mouse bone marrow.

SCID mice are profoundly immunodeficient, resulting from an inability to carry out the V(D)J recombination reaction during both B cell and T cell development. Recently, however, it was revealed that normal rearrangement frequently did occur in the TCR delta and gamma chain loci in the SCID thymus. To evaluate whether the normal rearrangement occurring in SCID is a T-cell-specific phenomenon, we directly cloned using PCR the DQ52-JH2 and DFL16.1-JH2 rearranged segments of the IgH gene from SCID bone marrow. The subsequent analysis revealed that normal V(D)J recombination occurred in a significant number of the analyzed clones. By quantitative Southern hybridization it was shown that the quantity of normal DQ52-JH2 joints existing in the SCID bone marrow is approximately 4-7% that in normal bone marrow. D-JH rearrangement in SCID mice and normal mice differs in the frequency of nucleotide insertion (N insertion). Although most of the normal mouse clones exhibited N insertion in the D-JH rearrangement, in SCID mouse clones N insertion was identified in only a few D-JH rearrangements. Furthermore, in several normal rearranged clones, the recombination occurred at the short homologous sequence. These observations suggest that the V(D)J recombination of IgH normally occurs at the early stage of SCID B cell development, just as TCR gene rearrangement occurs during SCID T cell development. Furthermore, the features of rearranged products isolated from SCID bone marrow cells were remarkably similar to those from leaky SCID mice.

Animals↗
PubMed1996

Stage-specific expression of mouse BST-1/BP-3 on the early B and T cell progenitors prior to gene rearrangement of antigen receptor.

Human bone marrow stromal cell antigen 1 (BST-1) was identified as a glycosylphosphatidyl-inositol-anchored ectoenzyme expressed on bone marrow stromal or synovial cell lines and having the ability to facilitate pre-B cell line growth. The analysis of the expression of mouse BST-1/BP-3 on the surface of lymphoid cells in the bone marrow and thymus revealed that it was very transiently expressed on both B and T cell progenitors undergoing gene rearrangement of the antigen receptor. Among CD45R+ CD43+ B cell progenitors in the bone marrow, BST-1 expression appeared on the CD24 (heat stable antigen)+, CD19+ or CD117 (c-kit)+ population. In the thymus, BST-1 was expressed on CD4-CD8-CD3- [triple negative (TN)] CD90 (Thy-1)+ cells. In TN thymocytes, the majority of CD25+ cells and CD44(10)/- cells expressed BST-1. In fetuses, BST-1+ cells appeared in the thymus and liver at day 14 and 16 of gestation respectively. The expression level of BST-1 by fetal thymus was maximal and > 60% of thymocytes were positive for BST-1 at day 15 or 16 and the proportion then gradually decreased during development. Among day 15 fetal thymocytes, BST-1 was negative on the CD44+ CD25- fraction, very slightly positive on the CD44+ CD25+ fraction, and strongly positive on the CD44(10)/- CD25+ and CD44-CD25- fractions. These results showed that murine BST-1 is a useful marker for lymphoid progenitor cells initiating gene rearrangement of their antigen receptors.

ADP-ribosyl Cyclase↗
PubMed1996

A new family of serine protease inhibitors (Bombyx family) as established from the unique topological relation between the positions of disulphide bridges and reactive site.

The positions of the reactive site and the disulfide bridges in fungal protease inhibitor F (FPI-F) from silkworm (Bombyx mori), which has a unique amino acid sequence and inhibitory specificity, were investigated. At pH 3.0, subtilisin BPN', which is one of target proteases of this inhibitor, specifically cleaved the peptide bond of the inhibitor at Thr(29)-Val(30). The cleaved bond was regenerated by subtilisin BPN' at pH 8.0. These results indicate that the Thr(29)-Val(30) bond of the inhibitor is the reactive site. The locations of disulfide bridges were determined to be Cys(3)-Cys(35), Cys(14)-Cys(27), Cys(18)-Cys(55), and Cys(37)-Cys(49). Based on the positions of the reactive site and the disulfide bridges, FPI-F is considered to be a member of a new family of serine protease inhibitors. We propose the designation Bombyx family for the new inhibitor family of which FPI-F is a member.

Amino Acid Sequence↗
PubMed1996

Purification and refolding of recombinant human proMMP-7 (pro-matrilysin) expressed in Escherichia coli and its characterization.

Human matrix metalloproteinase-7 (MMP-7 = matrilysin) was overproduced in Escherichia coli as a recombinant zymogen (31 kDa), the C-terminus of which bears artificial hexa-histidines. Most of the enzyme was isolated from the insoluble fraction of the cell lysate and purified by a single step using Ni-NTA resin after solubilization of the precipitates with 8 M urea solution. The resin-bound recombinant protein was refolded into a form that is activatable by p-amino-phenylmercuric acetate in an autocatalytic manner. The activated enzyme cleaved a synthetic peptide substrate at the reported site for MMP-7. Digestion of carboxymethylated transferrin (a natural substrate of MMP-7) by the recombinant proteinase generated fragments with the same peptide map as in the case of native purified MMP-7. The autocatalytic activation and enzyme reaction were entirely dependent on the presence of calcium and zinc ions. The enzyme activity to cleave carboxymethylated transferrin was inhibited by tissue inhibitors of metalloproteinases-1 and -2, MMP-specific inhibitors. The activity of the recombinant MMP-7 was also inhibited by a synthetic peptide derived from a part of the cysteine switch that maintains the zymogen in an inactive state. Thus, we report here a simple means of preparing a large quantity of recombinant proMMP-7 that can be used to study the activation mechanism and to screen synthetic inhibitors.

Amino Acid Sequence↗
PubMed1996

Expression of Bombyx family fungal protease inhibitor F from Bombyx mori by baculovirus vector.

Fungal protease inhibitor F (FPI-F) from silkworm hemolymph is a novel serine protease inhibitor of the Bombyx family. The cDNA of FPI-F was introduced into a baculovirus vector and a recombinant virus was isolated and plaque-purified. The protease inhibitory activities increased in the culture medium of insect cells and in the hemolymph of silkworms infected with the recombinant virus. Judged from the behavior on ion-exchange and reversed-phase chromatographies, amino acid compositions, amino-terminal sequences, and CD spectra, the recombinant FPI-F was identical with native FPI-F. Infection with the recombinant virus caused inhibition of larval development of the silkworm. However, the degree of the effect was different in two strains, Shinryukaku and Taiheichoan, indicating that the selection of the strain of silkworm is important in using the baculovirus expression system.

Amino Acid Sequence↗
PubMed1996

Noninvasive quantification of rCBF using positron emission tomography.

This study proposes a new method for the pixel-by-pixel quantification of regional CBF (rCBF) with positron emission tomography and H(15)(2)O by using a reference tissue region. No arterial blood is required. Simulation studies revealed that the calculation of rCBF was fairly stable provided that the frame time was relatively short compared with total scan time. In practice, calculated CBF images correlated significantly with those obtained with the dynamic/integral method. Because the method accurately detects changes in CBF, it is particularly suitable for brain activation studies.

Adult↗
PubMed1996

Salivacin 140, a novel bacteriocin from Lactobacillus salivarius subsp. salicinius T140 active against pathogenic bacteria.

Fifteen of 353 environmental isolates of lactic acid bacteria consistently showed activity against Listeria monocytogenes, Streptococcus mutans, Actinomyces viscosus, and/or Propionibacterium acnes. Strain T140, isolated from the surface of Japanese pampas grass leaves and identified as Lactobacillus salivarius subsp. salicinius, also had activity against several Lactobacillus species, Staphylococcus aureus and Yersinia enterocolitica. Since the antagonistic factor(s) produced by T140 was sensitive to a proteolytic enzyme, it was concluded that a bacteriocin (named salivacin 140) was involved in the inhibition activity. Strain T140 required a high initial pH (7.5-8.5) in agar plates for bacteriocin production.

Bacteria↗
PubMed1996

The Sendai paramyxovirus accessory C proteins inhibit viral genome amplification in a promoter-specific fashion.

Many paramyxoviruses express small basic C proteins, from an alternate, overlapping open reading frame of the P gene mRNA, which were previously found to inhibit mRNA synthesis. During recent experiments in which infectious Sendai virus (SeV) was recovered from cDNA via the initial expression of the viral N, P, and L genes from plasmids, the abrogation of C protein expression from the plasmid P gene was found to be necessary for virus recovery. We have investigated the effect of C coexpression on the amplification of an internally deleted defective interfering (DI) genome directly in the transfected cell, for which, in contrast to virus recovery experiments, genome amplification is independent of mRNA synthesis carried out by the SeV polymerase. We find that C protein coexpression also strongly inhibits the amplification of this DI genome but has little or no effect on that of a copy-back DI genome (DI-H4). We have also characterized the C protein from a mutant SeV and found that (i) it had lost most of its inhibitory activity on internally deleted DI genome amplification and (ii) its coexpression no longer prevented the recovery of SeV from DNA. However, consistent with the insensitivity of copy-back DI genomes to C protein inhibition, C coexpression did not prevent the recovery of copy-back nondefective viruses from DNA. The inhibitory effects of C coexpression thus appear to be promoter specific.

Gene Amplification↗
PubMed1996

Difference of serum levels of type IV collagen 7S between early or overt nephropathy and nondiabetic renal disease in diabetic patients with micro- or macroalbuminuria.

We determined serum levels of type IV collagen 7S (IV 7S) in 73 (23 with normoalbuminuria, 21 with microalbuminuria, 17 with macroalbuminuria, and 12 primarily affected by nondiabetic renal disease (NDRD)) and 24 (10 with only macroangiopathy and 14 with retinopathy and macroangiopathy) diabetic patients to see whether IV 7S can be a useful index for differentiating early or overt diabetic nephropathy from NDRD in micro- or macroalbuminuric diabetics. IV 7S was significantly elevated in diabetic patients with micro-or macroalbuminuria compared to those with normoalbuminuria and healthy controls (p < 0.001). On the contrary, all 12 diabetic patients with micro- or macroalbuminuria due to NDRD showed normal or low IV 7S level. IV 7S was significantly higher in diabetic patients with both retinopathy and macroangiopathy than in those with only macroangiopathy (p < 0.001). We conclude that IV 7S levels may be a useful index to differentiate diabetic early or overt nephropathy from NDRD, especially nephrosclerosis, in micro- or macroalbuminuric diabetics.

Aged↗
PubMed1996

Congenital afibrinogenemia with successful delivery.

We experienced a case of congenital afibrinogenemia and successfully performed cesarean section with administration of fibrinogen. The patient was administered fibrinogen every week to sustain a fibrinogen level above 60 mg/ dl according to our previously reported first case. Pregnancy course was uneventful, and fetal growth was normal, but unfortunately placental abruption occurred after the spontaneous onset of labor at 37 weeks gestation. The fibrinogen level before labor was 96 mg/dl, but decreased to 33 mg/dl when placental abruption was diagnosed. During and after the operation, it was increased to 147 and 199 mg/dl, respectively, through infusion of 10 g of fibrinogen, and massive bleeding was stopped. Two grams of fibrinogen were infused daily after cesarean section, and postpartum hemorrhage was normal. It is obvious that fibrinogen is an extremely important factor in maintaining pregnancy, and we conclude that fibrinogen level must be at least 60 mg/dl during pregnancy, 120 mg/dl during surgery and 150 mg/dl during labor, if possible as high as 200 mg/dl under the continuous infusion of fibrinogen to prevent placental abruption.

Adult↗
PubMed1996

Estimation of the optimal cut off point in a new immunological faecal occult blood test in a corporate colorectal cancer screening programme.

OBJECTIVE: To estimate the optimal cut off point in a new immunological method (OC-Hemodia) for faecal occult blood testing (FOBT). SETTING: A corporate colorectal cancer screening programme in Japan. METHOD - The screening programme targeted colorectal cancer and adenomatous polyps > or = 10 mm, and was conducted on 27 860 participants (age > or = 40 ) during 1991-92. The follow up consisted of diagnostic management by total colonoscopy on positive screened subjects exceeding the manufacturer recommended cut off level of 50 ng/ml faecal haemoglobin, and the identification of false negative cases by health insurance claims. The optimal cut off point was estimated by the positive predictive value, receiver operating characteristic (ROC) curve, and a cost effectiveness analysis. In this study evaluation was carried out only for cancer as the target disease. RESULTS: - At the current cut off level of 50 ng/ml the sensitivity and specificity were 86.5% and 94.9%. When the optimal cut off point was estimated the highest positive predictive value was obtained at 250-350 ng/ml. The ROC curve showed that the sum of sensitivity and specificity is maximised at 50 ng/ml, but evaluation of the ratio, change in sensitivity/change in false positive rate, pointed to higher optimal cut off points, showing marked changes occurring at about 200 ng/ml. The average cost per case was lowest at 250-300 ng/ml. Overall, the optimal cut off point was estimated to be about 200 ng/ml, at which the sensitivity and specificity of the test would be 77.5% and 98.9%, respectively. CONCLUSION: The optimal cut off point of the new immunological method of FOBT was estimated to be about 200 ng/ml, a value which, more than the current cut off value, favours specificity over sensitivity.

Adenoma↗