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T Kudo

Publications and source records attributed to T Kudo.

At least 19 recordsLinked to original sources
PubMed1992

Cumulative white matter changes in the gerbil brain under chronic cerebral hypoperfusion.

An animal model of chronic brain hypoperfusion has been developed by applying coiled clips to the bilateral carotid artery of Mongolian gerbils. The brain tissue damage was neuropathologically studied after 1, 4, 8, and 12 weeks of hypoperfusion. The hippocampus, basal ganglia, and cerebral cortex of the chronically hypoperfused gerbil showed lesions with various severity which are probably due to ischemic episodes. In the cerebral white matter, however, two types of lesions were observed; one similar to those in the gray matter, and the other observed only in the white matter after more than an 8-week duration of brain hypoperfusion. The lesion specific to the white matter showed rarefaction and gliosis without locally associated ischemic changes. This type of the white matter lesion was never found in the gerbil brain before 8 weeks and, significantly, increased in number and size by 12 weeks post operation. The accumulation of the white matter lesions is characteristic in the gerbil with chronic hypoperfusion. The observed white matter-specific lesion resembles the histological changes in aged brain with cerebrovascular diseases.

Animals↗
PubMed1992

Correlation between detection of anti-viral antibody and histopathological disease activity in an epidemic of hepatitis C.

There was an epidemic of non-A non-B hepatitis in a small area of a town in the central part of Japan, which began with an outbreak of several patients in 1981 and then spread extensively with the result that about one third of the inhabitants showed abnormality in serum liver function tests at the health check performed in 1985. We determined histological diagnoses on that occasion for 167 individuals of the abnormal population and recently assayed antibodies against hepatitis C virus (HCV) for most of their sera left available. Histologically, chronic active hepatitis (CAH) was the major pattern, accounting for 59.3% (99 cases) of the total. Others were chronic persistent hepatitis (CPH) (13.2%), chronic lobular hepatitis (CLH) (16.2%), liver cirrhosis (LC) (6.6%) and fatty liver (4.8%). In the serological studies, the newly developed system to detect antibodies against the viral core protein p 22 was found to be much more sensitive than the conventional system to detect anti C 100-3 antibodies. By using these two methods in combination, we found that 82% were antibody-positive, indicating strong implication of HCV in this epidemic. This was further supported by direct detection of the viral genome in patients' sera by polymerase chain reaction following reverse transcription. We further found a strong correlation between the histological inflammatory activity and the antibody prevalence, since nearly all (97.6%) of the CAH cases were antibody-positive by at least either of the antibody assays, while only about 50% were positive in the less active cases such as CPH and CLH.

Base Sequence↗
PubMed1992

A marked molecular heterogeneity of growth hormone (GH) detected in the plasma but not pituitary of a patient with acromegaly: comparison with other acromegalics and an implication for discrepant plasma levels of GH and insulin-like growth factor.

We experienced a 41-year-old acromegalic male (Case 1) in whom the basal plasma GH was extremely high (320-450 ng/mL) but plasma IGF-I was only slightly elevated (2.0-2.8 U/mL). His nutritional condition and associated diabetes mellitus did not appear to be responsible for the relatively low IGF-I level, and a GH-autoantibody in the plasma was absent. We thus performed gel filtration analyses of his plasma and somatotroph adenoma to determine elution patterns of immunoreactive (IR) and receptor active (RA) GH. For comparison, the same studies were carried out on plasmas and somatotroph adenomas obtained from three other acromegalics (Cases 2-4) whose basal plasma GH and IGF-I levels were 22-45 ng/mL and 3.5-6.0 U/mL, respectively. IR GH in Case 1's plasma distributed over an extremely wide range keeping similar titers rather than showing three discernible components (big-big, big, and little GH) as did plasmas and adenomas from Cases 2-4. And, most of the IR GH in Case 1's plasma was eluted in such fractions that contained low levels of RA GH, indicating a minor proportion of biologically active GH. However, interestingly, the chromatographic profile and total GH content of Case 1's adenoma were similar to those of Cases 2-4's adenomas. These results may, at least in part, explain the discrepancy between the plasma GH and IGF-I levels of Case 1. The unexpectedly different GH elution patterns between the plasma and adenoma from this patient, may suggest a contribution of certain plasma factor(s) to the unusual chromatographic profile of plasma GH.

Acromegaly↗
PubMed1992

Isolation and characterization of a Vicia graminea and Vicia unijuga lectins-binding (Vgu) glycoprotein with Thomsen-Friedenreich (T) activity from human liver metastases of pancreas carcinoma.

1. Perchloric acid-soluble fraction from liver metastases of pancreas carcinoma of a patient with blood group B, was subjected to a systematic affinity chromatography using Vicia unijuga lectin (VUA) and Arachis hypogaea anti-T lectin (PNA) as immobilized ligands and separated into three fractions, B-active glycoprotein fraction, serologically inactive glycoprotein fraction and glycoprotein (VP) fraction exhibiting reactivities for Vicia graminea lectin (VGA), VUA and PNA. 2. VGA- and VUA-binding (Vgu) glycoprotein with Thomsen-Friedenreich (T) activity which was isolated, in a high state of purity, from VP fraction by HPLC using Asahipak GS-710 column, was demonstrated to be a mannose-rich glycoprotein with mol. wt of 1492 kDa and contained 40.40% carbohydrate.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1992

Polyphosphoinositide metabolism in hypertrophic rat heart.

The accumulations of inositol-1,4,5-trisphosphate (IP3) and inositol-1,3,4,5-tetrakisphosphate (IP4) after hormonal stimulation may have a physiological role, possibly by alteration of Ca2+ levels in cardiac tissue. But the accumulation of inositol polyphosphate in a pathophysiological condition has not been studied. We investigated phosphatidylinositol-4,5-bisphosphate (PIP2) metabolism in hypertrophic cardiac myocytes, and clarified that the accumulations of IP3, IP4 and diacylglyceride after stimulation with norepinephrine were significantly enhanced in isolated myocytes from spontaneously hypertensive rat heart. Phospholipase C activity increased with age in SHRSP heart cells. These data suggest that PI turnover pathways, which can be mediated by both phosphatidylinositol-4,5-bisphosphate and diacylglyceride, may play an important role in development of hypertrophy in the hearts of rats with spontaneous hypertension.

Animals↗
PubMed1992

Platelet activating factor in culture media as an indicator of human embryonic development after in-vitro fertilization.

Although human chorionic gonadotrophin can detect trophoblast after implantation of the conceptus, there is a need to detect the conceptus before implantation. We have investigated whether human embryo-derived platelet activating factor is formed during embryonic development after in-vitro fertilization. A total of 99 ova from 12 patients were cultured and the 54 media were analysed. Platelet activating factor was also measured by radioimmunoassay after extraction. Fertilization increased the amount of platelet activating factor 4-fold over non-fertilized ova to a level of 4 ng/ml. This increase was also dependent on the degree of embryonic development with a maximum level of platelet activating factor of 7 ng/ml at the 2-cell stage. The follicular inducing agent used to treat the patient also had an effect on platelet activating factor; buserelin treatment gave embryos with a higher level than did clomiphene citrate treatment. These results indicate that platelet activating factor may have a role in embryonic development before implantation and may serve as a useful marker for fertilization and the developmental stage of the embryo.

Adult↗
PubMed1992

Analysis of the flagellin (hag) gene of alkalophilic Bacillus sp. C-125.

Motility of the alkalophilic Bacillus sp. C-125, a flagellate bacterium, was demonstrated to be Na(+)- and pH-dependent. Flagellin protein from this strain was purified to homogeneity and the N-terminal sequence determined. Using the hag gene of Bacillus subtilis as a probe, the hag gene of Bacillus sp. C-125 was identified and cloned into Escherichia coli. Sequencing of this hag gene revealed that it encodes a protein of 272 amino acids (M(r) 29,995). The predicted N terminal sequence of this protein was identical to that determined by N-terminal sequencing of the flagellin protein from strain C-125. The alkalophilic Bacillus sp. C-125 flagellin shares homology with other known flagellins in both the N- and C-terminal regions. The middle portion, however, shows considerable differences, even from that of flagellin from the related species, B. subtilis.

Amino Acid Sequence↗
PubMed1992

Molecular cloning and characterization of an alkalophilic Bacillus sp. C125 gene homologous to Bacillus subtilis sec Y.

A 1.8 kb HindIII DNA fragment containing the secY gene of alkalophilic Bacillus sp. C125 has been cloned into plasmid pUC119 using the B. subtilis secY gene as a probe. The complete nucleotide sequence of the cloned DNA indicated that it contained one complete ORF and parts of two other ORFs. The similarity of these ORFs to the sequences of the B. subtilis proteins indicated that they were the genes for ribosomal protein L15-SecY-adenylate kinase, in that order. The gene product of the alkalophilic Bacillus sp. C125 secY homologue was composed of 431 amino acids and its M(r) value has been calculated to be 47,100. The distribution of hydrophobic amino acids in the gene product suggested that the protein was a membrane integrated protein with ten transmembrane segments. The total amino acid sequence of alkalophilic Bacillus sp. C125 secY homologue showed 69.7% homology with that of B. subtilis secY. Regions of remarkably high homology (78% identity) were present in transmembrane regions, and cytoplasmic domains (73% identity) with less homologous regions present in extracellular domains (43% identity).

Amino Acid Sequence↗
PubMed1992

Intrinsic and drug-induced seizures of adult and developing gerbils.

Seizures elicited by posture change and intraperitoneal administration of convulsants were studied ontogenetically in the Mongolian gerbil (Meriones unguiculatus). In posture change, the first signs of seizure appeared after age 6 weeks with maximal frequency at 8-9 weeks. Adults developed complex, but stereotyped, seizures. Facial twitch was followed by the generalized convulsion, further progressing to trembling of the limbs and then kicking of the hindlimb (full seizure) after 55 days of age. Pentylenetetrazole induced a seizure similar to the full event in gerbils as young as 37 days of age. The seizure pattern elicited by strychnine or glutamate was different from that of pentylenetetrazole.

Animals↗
PubMed1992

Phylogeny of regulatory regions of vertebrate tyrosinase genes.

Highly homologous DNA elements were found to be shared by the upstream regions of the mouse tyrosinase and tyrosinase related protein (TRP-1) genes. Several nuclear proteins were shown to bind to both of these upstream regions. Shared homologous DNA elements were also found in the 5' flanking sequences of Japanese quail and snapping turtle tyrosinase genes. Shared homologous nucleotide sequences were found to be scattered like an archipelago in the 5' upstream regions of mouse and human tyrosinase genes. Comparisons between Japanese quail and snapping turtle tyrosinase genes gave similar results. On the contrary, mammalian (mouse and human) and nonmammalian (quail and snapping turtle) tyrosinase genes did not show significant homology in their 5' upstream regions. In contrast, coding sequences in the first exons of vertebrate tyrosinase genes and their deduced amino acid sequences were found to be highly conserved except for their putative leader sequence-coding regions.

Amino Acid Sequence↗
PubMed1992

Hereditary adrenocortical unresponsiveness to adrenocorticotropin with a postreceptor defect.

We report two cases in one pedigree with hereditary adrenocortical unresponsiveness to ACTH (HACUA) where it is suggested that the pathogenic defect occurs after cAMP generation. Although the patients showed increased plasma ACTH, decreased plasma cortisol and dehydroepiandrosterone, and no steroidogenic response to exogenous ACTH, they responded normally to both furosemide administration and to a low sodium diet by showing increases in plasma aldosterone. The peripheral blood mononuclear leukocytes (MNLs) from these patients possessed ACTH receptors similar to adrenocortical ones, which was in contrast to a previously reported case with a deficiency of ACTH receptors in the MNLs. Furthermore, ACTH receptors in the patients' MNLs were functionally coupled to adenylate cyclase. Dibutyryl cAMP infusion did not, however, increase plasma cortisol nor aldosterone in these patients in a sharp contrast to its remarkable increase in a normal control subject. These results suggest that these patients represent a new subtype of HACUA with a failure of intracellular reception of the cAMP message in adrenocortical cells. We propose to classify our patients with a postreceptor defect as HACUA type II using an analogy to pseudohypoparathyroidism type II.

Adenylyl Cyclases↗
PubMed1992

The studies of cell damaging and cell growth factors which induce cardiomyopathy.

We demonstrated that phosphatidylinositide-specific phospholipase C (PLC) activity was greater in cardiomyopathic hamster hearts (BIO 14.6 and BIO 53.58) then in hamster controls (F1b). Inositol trisphosphate (IP3) production was markedly greater in both of the cardiomyopathic hamsters, BIO 14.6 and BIO 53.58. We have also determined the sarcoplasmic reticulum (SR) function of heart. Calcium uptake into SR markedly increased in BIO 14.6. On the other hand, it significantly decreased in BIO 53.58 compared with F1b. It is well known that IP3 stimulates calcium release from SR. In BIO 14.6, calcium release from SR stimulated by IP3 increased, but its effect decreased in BIO 53.58 compared with F1b. These results suggest that PI response may produce high intracellular calcium levels in both BIO 14.6 and BIO 53.58 myocytes. In addition, in the BIO 53.58 hamster the sarcoplasmic reticulum deteriorate in function. It was concluded from these results that a prolonged high intracellular calcium level may lead to the death of BIO 53.58 myocytes. The expression of angiotensinogen mRNA was observed in the hamster heart. There was no differences in its expression level between F1b, BIO 14.6 and BIO 53.58. There was no effect of ages on its expression in these hamster hearts. We have also determined the distribution of angiotensinogen in these hamsters. At 4 weeks of age, the immunohistochemical study revealed that angiotensinogen was widely distributed in subendocardium in these hamsters. There was no difference in its distribution between F1b, BIO 14.6 and BIO 53.58. But at 20 weeks old of age its immunoreactivity decreased in BIO 53.58.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensinogen↗
PubMed1992

Phosphatidylinositol and inositolphosphatide metabolism in hypertrophied rat heart.

The accumulation of both Inositol-(1,4,5)-trisphosphate (IP3) and Inositol-(1,3,4,5)-tetrakisphosphate (IP4) after hormonal stimulation has a physiological role, possibly in altering Ca2+ levels in cardiac tissue. However, the accumulation of inositol polyphosphate under pathophysiological conditions has not been studied. In our experiments the metabolism of phatidylinositol and IP3 in cardiac myocytes as investigated. It was shown that basal levels of cytosolic phosphatidylinositol specific phospholipase C (PI-PLC), phosphatidylinositol-(4,5)-bisphosphate specific phospholipase C (PIP2-PLC) activities markedly increased in stroke-prone spontaneously hypertensive rats (SHRSP) with age compared with age matched Wistar Kyoto rats (WKY). IP3 kinase and IP3 phosphatase activities also increased in SHRSP hearts with age. Their activities increased in WKY, but to a lesser extent than in SHRSPs. These data suggest that a PI turnover pathway such as the phosphatidylinositol 4,5-bisphosphate-IP3-Ca2+ pathway or the diacylglyceride-protein kinase C pathway may have an important role in the development of hypertrophy in SHRSP heart.

Animals↗
PubMed1992

New strategies to establish human monoclonal antibodies.

In order to establish human monoclonal antibodies to any sort of antigens efficiently, we have made following two approaches. Our first approach is to improve cell fusion frequency. By improving our previous method for production of human hybridomas, we obtained higher frequency (1/700 vs. 1/5500) compared with our previous method by adding irradiated myeloma cells to culture of fusion cells and modifying the selective medium. Our second approach is to use a SCID-hu mouse for immunization. Since the injection of human PBL can result in the stable long-term reconstitution of a human immune system in SCID mouse, we tried to immune SCID-hu mouse with KLH. In the serum of immunized SCID-hu mouse, we obtained human IgG antibodies to KLH. Additionally, we succeeded in establishing human B lymphoblastoid cell lines which produced antibodies specific to KLH. These methods will open new prospects for the detection and therapy of cancer.

Absorption↗
PubMed1992

Effect of methylene blue on the vesicourethral function in the rats.

The bladder and urethral activities during the rhythmic bladder contractions were evaluated before and after the intraarterial administration of methylene blue, which prevents the activation of soluble guanylate cyclase. The methylene blue produced an increase in the bladder activity and a decrease in the urethral smooth muscle relaxant response induced with bladder contraction. The L-arginine/nitric oxide pathway seems to modulate the vesicourethral function.

Anesthesia↗
PubMed1992

Effect of taurine concentration on platelet aggregation in gestosis patients with edema, proteinuria and hypertension.

To elucidate the relationship between the high concentration of taurine in platelets and platelet aggregation in patients with EPH gestosis (gestosis with edema, proteinuria and hypertension), platelet aggregation and the platelet release response (release of ATP and beta-thromboglobulin) were studied in the washed platelet suspension (PS) obtained from normal pregnant or non-pregnant women and EPH gestosis patients. Platelet aggregation and platelet release response were significantly lower in EPH gestosis patients than in normal pregnant and non-pregnant women. Platelet aggregation, platelet release response induced by ADP and collagen and the aggregation induced by A23187 were inhibited in taurine-loaded PS from non-pregnant women. These results suggest that the decrease of platelet aggregation in EPH gestosis patients was caused by high concentrations of taurine in platelets, which may inhibit the intracellular Ca2+ movement and platelet release response. Therefore, taurine appears to have a protective effect against the hyper-coagulative state in EPH gestosis.

Adenosine Diphosphate↗