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Biomedical subjects

T Higuchi

Publications and source records attributed to T Higuchi.

At least 343 records · Page 19Linked to original sources

Hypocomplementemia and hematological abnormalities in immunoblastic lymphadenopathy and immunoblastic lymphadenopathy-like T cell lymphoma.

Serum complement levels and hematological data were evaluated in five patients with immunoblastic lymphadenopathy (IBL) and four with IBL-like T cell lymphoma (IBL-T). Anemia with Hb values below 10.0 g/dl was seen in four patients. A direct Coombs test was positive in five patients and the bone marrow of two of these showed features of pure red cell aplasia. Seven patients were thrombocytopenic with platelet counts below 100 x 10(9)/l. Six of the seven patients had splenomegaly. Platelet-associated IgG was elevated in all three thrombocytopenic patients examined. Whole complement activity (CH50) was reduced in eight patients (89%) at presentation and subsequently normalized in five who were treated either with prednisolone (two patients with IBL) or with multidrug combination chemotherapy (three with IBL-T). One patient achieved complete remission and four partial remission. Remission was accompanied by normalization of hematological abnormalities and elevation of complement activity to the normal range in all cases. These results suggested that complement-mediated mechanisms are responsible, at least in part, for some of the hematological abnormalities observed in IBL and IBL-T and that hypocomplementemia is a common abnormality with significance as a laboratory marker for the disease activity.

Aged↗

Requirement for transglutaminase in progesterone-induced decidualization of human endometrial stromal cells.

Differentiation of endometrial stromal cells (decidualization) is essential for embryo implantation and maintenance of pregnancy. By sequential complementary DNA subtractive hybridization, one of the messenger RNAs (mRNA) induced by progesterone in human endometrial stromal cells decidualized in vitro was identified as that of a tissue transglutaminase type II (TGase). TGase mRNA was induced within 6 h after the addition of progesterone to the culture, and the effect was dose dependent. Both the TGase inhibitor monodansylcadaverine and oligodeoxynucleotide complementary to the TGase mRNA inhibited the decidualization, as assessed by PRL production and morphological transformation. Expression of TGase mRNA in human decidua and endometria exposed to high levels of progesterone in vivo was demonstrated by Northern blotting and in situ hybridization. These data suggest that TGase is necessary for the decidualization of human endometrial stromal cells and that clarification of the mechanism of action of TGase will facilitate further insight into the diagnosis and treatment of infertility.

Base Sequence↗

Thiopalmitic acid-mediated Fe(III)-nitrilotriacetate reduction and lipid peroxidation.

The mechanism of the antioxidant action of thiopalmitic acid (SH-Pal) was examined in an in vitro system measuring ferric (Fe(III)-nitrilotriacetate (NTA)- and Fe(III)-NTA/ascorbic acid (AsA)-induced lipid peroxidation of rat liver phospholipid liposomes and microsomes. The extent of lipid peroxidation was determined by measuring thiobarbituric acid reactive substances (TBARS). SH-Pal and glutathione (GSH) scarcely stimulated the Fe(III)-NTA-induced lipid peroxidation in contrast with the mode of action, being similar to those produced by reducing-agent antioxidants such as cysteine and AsA. SH-Pal reduced iron similar to the action produced by AsA and cysteine, but not that of GSH under the same conditions. Also, the reduction of iron by SH-Pal did not exhibit a pH dependency. Similarly, microsomal lipid peroxidation and oxygen consumption induced by Fe(III)-NTA/AsA were inhibited by the addition of SH-Pal in a time and dose dependent fashion, but GSH and cysteine exhibited a lower protective action. Time course studies on TBARS formation and oxygen consumption indicated the ability of SH-Pal to inhibit initiation and propagation reactions. Moreover, the microsomal lipid peroxidation induced by Cumene hydroperoxide (CumOOH) was progressively suppressed by the addition of increasing amounts of SH-Pal. These findings suggest that the antioxidant action of SH-Pal is partly due to complete reduction of iron at a faster rate and inhibition of oxygen consumption during the progress of the peroxidation. Further, SH-Pal has a protective action against free radical damage by hydroperoxy radical.

Animals↗

Effects of methyl 9(or 10)-hydroxy-10(or 9)-mercaptostearate and hexadecanethioic S-acid on cupric ion- or 2,2-azo-bis(2-amidinopropane) dihydrochloride (AAPH)-induced oxidation of low density lipoprotein.

The preventive effects of two antioxidants, methyl 9(or 10)-hydroxy-10 (or 9)-mercaptostearate (SH-S) and hexadecanethioic S-acid (thiopalmitic acid, SH-Pal) against the oxidative modification of low density lipoproteins (LDL) induced by cupric ion or a water soluble initiator of peroxyl radicals, 2,2-azobis(2-amidinopropane) dihydrochloride (AAPH), were studied by measuring thiobarbituric acid-reactive substances (TBARS). SH-S acted as an effective antioxidant in the oxidative modification of LDL induced by either cupric ion or AAPH. Interestingly, SH-S completely inhibited the formation of fluorescence products and decreased both the fluorescence and alpha-tocopherol content in LDL induced by cupric ion, and reduced 1,1-diphenyl 2-picrylhydrazyl (DPPH) used as a stable free radical model. The antioxidative effect was effectively prevented by the addition of increasing amounts of N-ethylmalemide (NEM) to the system. SH-Pal also inhibited the cupric ion-induced LDL oxidation, but showed little inhibitory effect on the AAPH-induced LDL oxidation. Moreover, SH-Pal was reduced to palmitic acid during the AAPH-induced LDL oxidation. These findings indicate that SH-S protects against oxidative damage of LDL in vitro, and that it acts as a free radical in peroxidation. In addition, this study shows that SH-Pal doesn't act as an efficient antioxidant in AAPH-induced lipid peroxidation.

Amidines↗

Acid lipase inhibitor in chicken plasma identified as apolipoprotein A-I.

We have reported a inhibitor of acid lipases in liver lysosomes and erythrocytes from chickens [M. Fujii et al., Int. J. Biochem., 22, 895-898 (1990)]. In this paper, the properties of the inhibitor were described in comparison with those of apo A-I of chicken. The purified inhibitor migrated with the same mobility on SDS-PAGE as apo A-I, and had a molecular weight of 27,000. The peptide map from the lipase inhibitor was similar to that of apo A-I. Antibodies to the acid lipase inhibitor also reacted with apo A-I. Apo A-I inhibited the acid lipase activities of liver lysosomes and erythrocytes from chickens as strongly as the lipase inhibitor. The N-terminal amino acid sequence of lipase inhibitor was identical to that of apo A-I as far as residue 20. The amino acid sequence of peptides obtained from the inhibitor by cleavage with CNBr corresponded to internal sequence of apo A-I, and so the CNBr-peptides were derived by cleavage after the methionine residues in apo A-I. The findings showed that the inhibitor of the acid lipases in liver lysosomes and erythrocytes from chickens was identical to apo A-I.

Amino Acid Sequence↗

Characterization of non-pigmented Staphylococcus chromogenes.

A large number of non-pigmented Staphylococcus chromogenes were isolated from the skin of piglets with exudative epidermitis and healthy pigs. Their characteristics were homologous with S. chromogenes type strain, except for pigment production. Strains of non-pigmented S. chromogenes exhibited high levels of DNA homology with S. chromogenes type strain. The colony morphology and pigmentation of non-pigmented S. chromogenes was very similar to S. hyicus type strain, but their characteristics differ in hyaluronidase production, heat stable DNase, Tween 80 hydrolysis and bacitracin resistance. Further, DNA homology drew a distinction between non-pigmented S. chromogenes and S. hyicus type strain.

Animals↗

Changes in oxytocin receptor mRNA in the rat uterus measured by competitive reverse transcription-polymerase chain reaction.

Large changes in the responsiveness of target organs to oxytocin are thought to originate from alteration of the number of oxytocin receptors (OTR). To elucidate the molecular mechanisms regulating the synthesis of the OTR, we developed a competitive reverse transcription-PCR protocol to measure OTR mRNA. We synthesized cRNA comprising a small stuffer introduced into the target mRNA. Using this cRNA as an internal standard, we made a quantitative estimation of OTR mRNA. Application of this method to the rat uterus revealed that the mean levels of OTR mRNA remained unchanged until 1030-1100 h on day 21 of pregnancy, increased significantly after 2200-2230 h on the same day and declined rapidly after parturition. A similar rapid increase in uterine OTR mRNA content was observed in rats given prostaglandin on day 18, inducing premature delivery on day 19 of pregnancy. All parturient rats had higher OTR mRNA levels regardless of whether parturition was spontaneous or prostaglandin induced. However, in a few rats, OTR mRNA remained as low as that observed during mid pregnancy even on day 22 of gestation, the expected day of parturition in about 70% of the rats in our colony. A similar increase in uterine OTR mRNA content to that observed at parturition was induced by oestrogen treatment for 3 days in ovariectomized virgin rats, but concomitant injection of progesterone did not influence the effect of oestrogen. The present results revealed that the large increase of uterine OTR at the peripartum period is accompanied by an increase in OTR mRNA content that may be brought about, at least in part, by increased oestrogen secretion following luteolysis.

Animals↗

Development of plant growth apparatus using blue and red LED as artificial light source.

It is known that chlorophyll has the second distinct absorption peak in the vicinity of 450nm (blue light region) other than the first peak in the vicinity of 660nm (red light region) in its light absorption spectrum The blue light is also indispensable to the morphologically healthy growth plant. On the other hand, the red light contributes to the plant photosynthesis. Noticing this facts, we have developed various kind of plant growth apparatus using many pieces of blue light LED and red light LED with emission wavelength 450nm and 660nm as artificial light source. In this paper, we introduce our LED plant growth apparatus and systems named such as LED PACK, BIOLED, UNIPACK, and COMPACK with respect to their structure, function, electrical design, and characteristics.

Ecological Systems, Closed↗

Spinal epidural abscess associated with epidural anesthesia: gadolinium-enhanced magnetic resonance imaging and its usefulness in diagnosis and treatment.

A case of spinal epidural abscess following epidural anesthesia is described. Gadolinium-enhanced magnetic resonance images were essential in diagnosis of the abscess without frank pus formation, in defining the extension of the infection, and in assessing the therapeutic effect. The patient was successfully treated non-operatively before neurological symptoms developed and full recovery was achieved.

Abscess↗

Prognostic implications in myelodysplastic syndromes: A review of 62 cases.

We retrospectively reviewed 62 MDS patients (15 RA, 3 RARS, 10 CMML, 20 RAEB, 14 RAEBT) to clarify the current problems in their management. Median survival of RA and RARS patients was 67.9 months and significantly longer than that of CMML, RAEB, or RAEB-T patients with median survivals of 16.1, 16.8, and 9.5 months, respectively. Karyotypic abnormalities were observed in 58% of the patients examined. Forty-two patients died, 16 (38%) of leukemic transformation and 21(50%) of bone marrow failure. While most of the RAEB-T patients of all ages and all the RAEB patients diagnosed below 60 years of age died of transformation, 70% of the older RAEB patients died of infection. Prognosis after transformation was poor and 12 patients died within two months. These results indicate that management after transformation and treatment against infection in RAEB patients with advanced age are crucial to improve the prognosis in MDS.

Adult↗

[Ectopic bone induction in recombinant human bone morphogenetic protein-2 (rhBMP-2) combined with biphasic calcium phosphate (BCP)].

The purpose of this study was to investigate the efficacy of BCP granules combined with rhBMP-2 for ectopic bone formation in rats. BCP granules were used as a carrier for rhBMP-2. The rhBMP-2 was adsorbed to BCP granules under the reduction of pressure. Twenty Wistar rats were used for this experiment and were divided into 4 groups according to the concentration (0,2,10,50 micrograms/700 microliters) of rhBMP-2 implanted in each rat. The BMP and BCP complex was implanted under the dorsal skin of the rats. Three weeks after the implantation, the rats were sacrificed. The experimental sites were immediately dissected and histological sections were prepared. In the 50 micrograms group, new bone formation was observed in all rats, while bone tissue was not found in the 2 micrograms and 0 microgram groups. These results indicated that BCP combined with rhBMP-2 could effectively induce ectopic bone formation. It was suggested that BCP granules alone could be applicable as a carrier for rhBMP-2 in order to induce new bone formation.

Animals↗

Grade II astrocytoma visualized by technetium-99m-ECD SPECT.

We present a case of primary brain tumor demonstrating increased uptake of 99mTc-ECD. Astrocytoma (Grade II) showed significantly increased cerebral blood perfusion on dynamic images and homogeneously increased uptake on static images with 99mTc-ECD brain SPECT. There seems to be some difference in perfusion and mechanism of tumor uptake among the cerebral blood flow imaging agents (99mTc-ECD, 99mTc-HMPAO and [123I]-IMP) and 201TI-chloride.

Adult↗

Comparative studies of human recombinant 74- and 54-kDa L-histidine decarboxylases.

We have expressed and characterized human recombinant 74-kDa (rHDC74) and 54-kDa (rHDC54) L-histidine decarboxylases (HDCs) in Sf9 cells. By immunoblot analysis, rHDC74 and rHDC54 were shown to be localized predominantly in the particulate and soluble fractions, respectively. rHDC74 exhibited histamine-synthesizing activity equivalent to that of rHDC54. The existence of 74- and 54-kDa HDCs was also confirmed in the particulate and supernatant fractions of the cell lysate, respectively, from the human basophilic leukemia cell line KU-812-F. The ratio of HDC activity to immunoreactivity was similar for the two forms of the enzyme. The specific activity of purified rHDC54 (1.12 mumol/mg/min) was comparable to those of HDCs from other mammalian tissues or cells. The purified rHDC54 was eluted as a monomer form from a Superdex-200 column; the molecular mass of the enzyme was approximately 54 kDa on SDS-polyacrylamide gel electrophoresis without 2-mercaptoethanol. The HDC activity of rHDC54 significantly decreased on dialysis against buffer without pyridoxal 5'-phosphate; addition of pyridoxal 5'-phosphate to the dialysate readily increased in the enzyme activity to the original activity. Taken together, these results suggest that human HDC functions as both 74- and 54-kDa forms having equivalent HDC activity, which are localized in the particulate and soluble fractions, respectively, and that the latter form exhibits its activity as a monomer form.

Animals↗