Biomedical subjects

E Yamada

Publications and source records attributed to E Yamada.

At least 73 records · Page 4Linked to original sources

PubMed1997

Severe cutaneous and venous damage after DIC therapy.

A 79-year-old woman with skin ulcers caused by disseminated intravascular coagulation (DIC) therapy is reported. The patient had been treated by injection of drugs, including gabexate mesilate, into the right great saphenous vein. The maximum concentration of gabexate mesilate was calculated as 0.893%. Although the drugs did not extravasate, purpura initially appeared around the affected vein, followed by brown pigmentation with infiltration and ulcers with widely necrotic tissue from the middle portion of her thigh to the malleolus along her right great saphenous vein. As the ulcer showed no tendency to heal for more than 3 months, surgical debridement and skin grafts were performed.

Aged↗

PubMed1996

Enzymatic characterization of purified NS3 serine proteinase of hepatitis C virus expressed in Escherichia coli.

Non-structural protein 3 (NS3) of the hepatitis C virus (HCV) has been shown to be a serine proteinase which cleaves the HCV polyprotein thus activating its replicative machinery. To characterize enzymatic activities of NS3 serine proteinase, the proteinase region was expressed in Escherichia coli and purified. The purified proteinase specifically cleaved a purified fusion protein sandwiching the NS5A/5B cleavage sequence. In addition to serine proteinase inhibitors, some chelators also inhibited the cleavage activity. Metal ions were not required for its activity, suggesting that the proteinase may be a novel serine proteinase having a unique binding site for chelators.

ATP-Binding Cassette Transporters↗

PubMed1996

A new HLA-DQB10306 allele sharing motifs from DQB103032 and DQB1*04 sequences.

We have discovered a new HLA-DQB1 allele in a Japanese family, MAT. In the family the new allele segregates in three generations and demonstrates the positive association with DRB1*0901. We observed a novel RFLP pattern in the course of examining the modified PCR-RFLP method for HLA-DQB1 genotyping. The PCR-SSOP analysis also showed a new hybridized pattern. Sequence analysis of the allele indicates that it was generated by a gene conversion-like event between the HLADQB1*03032 and one of DQB1*04 contemporary alleles. This new allelic product did not react with all of allosera and monoclonal antibodies against DQ1, DQ2, DQ3, DQ4 and DQ7. The HLA molecule encoded by the allele is not defined by serology. This new allele was officially recognized and named DQB1*0306 by the WHO Nomenclature Committee in November 1995.

Alleles↗

PubMed1996

Interleukin-6 (IL-6) inhibits thyroid function in the presence of soluble IL-6 receptor in cultured human thyroid follicles.

Interleukin-6 (IL-6), a pleiotropic cytokine, is postulated to be involved in the pathogenesis of sick euthyroid syndrome, although the direct in vitro effects of IL-6 on human thyroid function are controversial. Because IL-6 signal can be transduced when the complex of IL-6 and soluble IL-6 receptor (sIL-6R) binds to gp 130, an IL-6 signal transducer, we studied the effects of IL-6 and sIL-6R on thyroid function, using human thyroid follicles obtained from patients with Graves' disease. IL-6 alone had no inhibitory effect on TSH-induced thyroid function (125I incorporation and organic 125I release), even at supraphysiological concentrations. However, in the presence of physiological concentrations of sIL-6R (100 ng/ml), IL-6 inhibited thyroid function dose dependently and completely, accompanied with the decreased ratio of 125I-T3/125I-T4 not only in the thyroid follicles but also in the culture medium. Thyroid follicles did not secrete sIL-6R but produced IL-6 constitutively. Consistent with these findings, sIL-6R inhibited thyroid function slightly at high concentrations. Furthermore, RT-PCR analyses revealed that human thyroid follicles expressed the messenger RNAs for IL-6 and gp130 but scarcely messenger RNA for IL-6R. These in vitro findings suggest that IL-6 alone hardly affects thyroid function in thyroid follicles in which IL-6R gene is scarcely expressed. However, because sIL-6R is present abundantly in serum, IL-6 in vivo would be capable of inhibiting the synthesis and release of T4 and, to a greater extent, T3 from the thyroid gland. These in vitro findings are at least partly related to the development of sick euthyroid syndrome.

Analysis of Variance↗

PubMed1996

A new technique of extracapsular restoration with a tie made of ethylene tetrafluoroethylene (ETFE) for rupture of the cranial cruciate ligament in dogs.

A new extracapsular technique for repair of canine cranial cruciate ligament rupture using an ethylene tetrafluoroethylene (ETFE) tie was presented. Eighteen dogs (body weight: 6.0-46 kg) with this problem were used for this study. The advantages of this method were 1) the operation was easily performed. 2) Joint could be stabilized by proper fixation with microadjustment during operation. 3) This method presented less surgical invasion than the intracapsular one, since wide incision was not conducted over peripheral tissue of the stifle joint.

Animals↗

PubMed1996

A new method to selectively injure the optic nerve using argon-laser photocoagulation.

To create a model by noninvasive means for the study of Wallerian and transneuronal degeneration of the central nervous system, we devised a two-step argon laser photocoagulation (ALP) procedure with which we could selectively injure the optic nerve in rats. Changes in the optic nerve distal to the site of injury were studied histologically to evaluate this method; we succeeded in selectively and completely injuring the optic nerve. We found this ALP technique to be superior to either the panretinal or one-step photocoagulation method. Changes within astrocytes of the intracerebral optic tract and the lateral geniculate body in animals were also studied immunohistochemically following ALP and compared with those which follow enucleation. Reactive astrocytes with enhanced immunoreactivity for glial fibrillary acidic protein (GFAP) increased in number in the intracerebral optic tract and in the lateral geniculate body on the contralateral side of the optic injury in both groups of animals. The increased GFAP immunoreactivity was sustained for 6 weeks following injury; the proliferative tendency of the glial cells, shown by the bromodeoxyuridine method, peaked 3 days after injury and then decreased gradually. These glial responses in the optic tract and lateral geniculate body of animals subjected to ALP are similar to those of animals following enucleation. Our results indicate that this new technique for selectively and noninvasively injuring the optic nerve with ALP is applicable to the study of Wallerian and transneuronal degeneration.

Animals↗

PubMed1996

Parallel pathways in the retina of Old and New World primates.

Old-world simians are all trichromats, but in most new-world primates there is a polymorphism; males are dichromats but most females are trichromats. In the old world simian, luminance and red-green chromatic channels defined by psychophysical experiments have as a basis parasol ganglion cells of the magnocellular (MC) pathway and midget ganglion cells of the parvocellular (PC) pathway respectively. Small bistratified ganglion cells provide a basis for a blue-yellow chromatic channel, which should probably be considered a separate entity. In both dichromatic and trichromatic new-world animals, the MC pathway and the small bistratified, blue-yellow system seem anatomically and physiologically similar to those in their old-world relatives. The midget ganglion cells of the parvocellular pathway in trichromats are anatomically and physiologically similar to the old-world pattern. In dichromatic animals, they are anatomically similar and physiologically resemble those of trichromatic animals, except for the lack of chromatic opponency. We conclude that these three systems may from a basic pattern for the visual pathway of primates. However, the results from dichromats indicate that the evolution of trichromacy may be found to be more complex than presently supposed.

Animals↗

PubMed1995

cDNA cloning of mouse ferredoxin reductase from kidney.

A cDNA encoding ferredoxin reductase has been isolated from a mouse kidney cDNA library using human ferredoxin reductase cDNA as a probe. Mouse ferredoxin reductase coded for 494 amino acid residues. The mouse mature enzyme which comprises 460 amino acid residues shared 87.8-89.1% amino acid identities with the bovine and human enzyme. Northern blot analysis showed that ferredoxin reductase mRNA was expressed in the adrenal, testis and ovary and to a lesser extent in the liver and kidney. However, this mRNA in the adrenal cell line, Y-1 cell, was not induced by adenosine 3',5'-cyclic monophosphate (cAMP) in contrast with ferredoxin mRNA.

Amino Acid Sequence↗

PubMed1995

Molecular cloning of 25-hydroxyvitamin D-3 24-hydroxylase (Cyp-24) from mouse kidney: its inducibility by vitamin D-3.

A cDNA encoding a 25-hydroxyvitamin D-3 24-hydroxylase, Cyp-24, has been isolated from mouse kidney cDNA library by hybridization screening. Mouse Cyp-24, coding for 514 amino acid residues, shared 82.1 and 94.7% amino acid identity with human and rat CYP24s, respectively. Among mouse organs examined, Cyp-24 mRNA could be detected in the kidney. When mice were treated with vitamin D-3, Cyp-24 mRNA was induced in the kidney.

Amino Acid Sequence↗

PubMed1995

Mouse cytochrome P-450 linked ferredoxin: its cDNA cloning and inducibility by dibutyryladenosine 3',5'-cyclic monophosphate and forskolin.

Two full-length cDNAs (F1-1 and F41-1) complementary to mouse kidney mRNA coding for cytochrome P-450 (P450) linked ferredoxin were isolated and completely sequenced. The coding sequences between F1-1 and F41-1 were identical. However, the 3' untranslated regions of F1-1 and F41-1 were 228 and 27 bases long due to the presence of alternative polyadenylation sites, respectively. The deduced amino acid sequence of mouse cytochrome P-450 linked ferredoxin showed 92.5, 75.0, 71.2 and 71.0% identities with those of rat, human, pig and bovine cytochrome P-450 linked ferredoxin, respectively. The cytochrome P-450 linked ferredoxin mRNA was detected in adrenal, kidney and ovary among the organs examined. The treatment of Y-1 cells with dibutyryladenosine 3',5'-cyclic monophosphate or forskolin induced the transcript of cytochrome P-450 linked ferredoxin mRNA.

Amino Acid Sequence↗

PubMed1995

Effective production of the hepatitis C virus core antigen having high purity in Escherichia coli.

The amino-terminal half of putative nucleocapsid (core) protein (amino acids 1-115) of hepatitis C virus (HCV) was directly overproduced in Escherichia coli under the control of the tac promoter. Overproduction of core antigen was achieved by inserting several target genes and by optimizing the culture conditions, whereas a large amount of directly expressed and purified core antigen has not yet been reported. Although the level of expression was comparable to that of the conventional E. coli fused expression system, our recombinant proteins contain only HCV amino acid sequence. Using recombinant E. coli, overproduced large-scale culture system was achieved in jar-fermenter. A highly purified sample of the expressed protein was obtained by ion-exchange and gel permeation column chromatography in the presence of 8 M urea. From a 3.5 l culture, approximately 440 mg of recombinant core protein was obtained after a two-step purification procedure. An enzyme-linked immunosorbent assay developed using the highly purified antigen satisfactorily diagnosed hepatitis C.

Base Sequence↗

PubMed1995

Usefulness of a prototype intravascular ultrasound imaging in evaluation of aortic dissection and comparison with angiographic study, transesophageal echocardiography, computed tomography, and magnetic resonance imaging.

The aim of this study was to evaluate the accuracy of information obtained with a prototype intravascular ultrasound (IVUS) system in chronic aortic dissection by comparing results with angiography, transesophageal echocardiography (TEE), computed tomography, or magnetic resonance imaging. We assigned 15 patients to IVUS imaging after they underwent angiography. The detection rate of the intimal flap was 100% in all segments of the aorta, and the detection rate of the intimal tear was 0%, 50%, 50%, and 77.8% in the ascending, arch, descending, and abdominal aorta, respectively. IVUS demonstrated 100% of the celiac and renal arteries, and 80% of the superior mesenteric arteries as well as their relation to dissection. It clarified the origin of 12 of 60 main abdominal branches (20%) which were not clear on the angiogram. It also determined the distal extent of the dissection in all cases. With regard to the size of the vessel, there was a good correlation between IVUS and computed tomographic values (r = 0.98, p < 0.01). No complications occurred in any patient. IVUS accurately demonstrated thrombus or spontaneous echo contrast in the false lumen that was confirmed with computed tomography or TEE, or both. It was especially useful in evaluating the abdominal aorta with regard to determining the size of the vessel, the extent of dissection, the relation of the branches to the false lumen, and the detection of intimal tears--important information for follow-up of patients and for planning surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

Increased immunoreactivities for the basic fibroblast growth factor and its receptor in astrocytes at the site of cerebral lesions and oedematous change in SHR.

1. To obtain information about changes of basic fibroblast growth factor (bFGF) in the brain in chronic hypertension, we immunohistochemically studied the distribution and level of bFGF and its receptor in the brain of stroke-prone spontaneously hypertensive rats (SHRSP). 2. In the control normotensive rats, immunoreactivity for bFGF was demonstrated in nerve cells, while there was almost no reactivity in astrocytes. 3. In SHRSP, there was a marked immunoreactivity in the densely accumulated reactive cells, particularly astrocytes, in and around cerebral cortical lesions. Slightly increased reaction for bFGF was found in the nerve cells around lesions. Astrocytes in the subcortical white matter on both ipsi- and contralateral sides of the cortical lesion also showed immunoreactivity for bFGF. The location of increased bFGF expression in SHRSP corresponded very well with the site of extravasated plasma fluid demonstrated by anti-fibrinogen antibody. Electron microscopically, bFGF was shown in astrocytes along the rough endoplasmic reticulum suggesting the growth factor to be produced in the cells and not to be taken up from the surroundings. Expression of FGF-receptor was also demonstrated in reactive astrocytes in the oedematous cortical portion around lesion and in the oedematous subcortical white matter. 4. These findings indicate the possibility that oedema and the simultaneously generated free radicals or some extravasated plasma components express bFGF in astrocytes and probably in nerve cells as well as FGF-receptor in astrocytes, and that the thus expressed bFGF and its receptor play some role in the sequence of developmental events of hypertensive cerebral lesions.

Animals↗

PubMed1995

Effect of intestinal resection and arginine-free diet on rat physiology.

The small intestine has been presumed to release citrulline as a precursor for the endogenous arginine synthesis. We studied the effect of intestinal resection and arginine-free diet on rat physiology. We maintained rats with massively resected small intestine (R rats) and those with transected intestines (T rats) on either control or an arginine-free diet. After 4 wk, R rats fed deficient diet [R(-)] lost weight by a mean of 46 g, whereas R rats fed control diet [R(+)] and T rats fed control [T(+)] and deficient diet [T(-)] gained 30-96 g. Average nitrogen balance was 150, 60, 110, and -33 mg/day for T(+), T(-), R(+), and R(-), respectively. The concentrations of arginine in skeletal muscle were 654, 163, 230, and 84 nmol/g, respectively, and those in plasma were 133, 50, 103, and 54 microM, respectively. The concentrations of citrulline in R rats were halved compared with T rats irrespective of diet. We conclude that arginine is synthesized in a small intestine-dependent manner in the rat.

Amino Acids↗

PubMed1995

Immunological and biochemical characterization of biglycan-like haemopoietic factor.

Immunological and biochemical characteristics of a 100,000 MW biglycan-like haemopoietic factor, purified from thymic myoid cells 871207B, were studied to distinguish them from macrophage colony-stimulating factor (M-CSF), which they resemble in activity and biochemical properties. Rabbit antibody raised against a synthetic peptide fragment (J-1) designed from amino acid sequences specific to the 100,000 MW factor responded to 871207B cells, the conditioned medium of 871207B, and capillary-like structures in the thymus, but not to M-CSF producer L-929 cells or the conditioned medium of L-929 cells. In contrast, M-CSF epitope was detected in L-929 cells and the conditioned medium cells but not in 871207B cells or the conditioned medium, even after enzymatic digestion of glycosaminoglycan chains. Treatment of the 100,000 MW factor with chondroitinase ABC and AC produced a 50,000 MW component. Digestion of this product with N-glycanase resulted in a 40,000 MW protein component. These results suggest that the 100,000 MW factor is a proteoglycan consisting of a core protein with an apparent molecular mass of 40,000 MW, a 50,000 MW chondroitin sulphate chain and 10,000 MW N-linked oligosaccharide chains. A small amount of a 40,000 MW monocytic cell growth activity was also found in the 871207B cell-conditioned medium. An enzymatically obtained 40,000 MW factor, the conditioned medium 40,000 MW factor, and the 100,000 MW factor were specifically eluated from an anti-J-1 IgG-immobilized affinity column with monocytic cell growth activity, suggesting that the biological activity resides in the 40,000 MW core protein. The 100,000 MW factor induced the proliferation and differentiation of monocytic lineage cells from a variety of sources, such as bone marrow cells, peritoneal exudated cells and brain microglia cells.

Amino Acid Sequence↗

PubMed1995

Intimate association of H(+)-ATPase vesicles with mitochondria in the intercalated cell of the renal collecting duct.

It is known that the intercalated cell of the renal collecting duct contains, in addition to abundant mitochondria, characteristic spherical or flat vesicles whose cytoplasmic surfaces were decorated with H(+)-ATPase studs. The intimate association of H(+)-ATPase vesicles with mitochondria was often observed. Here, the limiting membrane of the vesicle and the outer mitochondrial membrane were directly connected to each other by H(+)-ATPase studs. Namely, two membranes were bridged by these studs. This feature was especially evident in the case of flat vesicles. These findings indicated the close interplay between these two cell organellae.

Animals↗

PubMed1994

Arginine becomes an essential amino acid after massive resection of rat small intestine.

We compared effects of feeding arginine- and/or proline- deficient diets (-Arg, -Pro, and -Arg, Pro) with those of a complete diet (Complete) in rats whose small intestine had been massively resected. After 4 weeks, the rats fed -Arg and -Arg, Pro lost weight (a mean of 28 and 32 g, respectively), whereas those fed Complete and -Pro gained 80 and 58 g, respectively. The average nitrogen balance was about 117,100, -20 and -14 mg/day for Complete, -Pro, -Arg, and -Arg, Pro diets, respectively. The concentration of arginine in skeletal muscle was about 310, 330, 91, and 65 nmol/g for Complete, -Pro, -Arg, and -Arg, Pro, respectively; while plasma arginine concentration averaged 95, 107, 56, and 46 microM, respectively. The weight loss, the negative nitrogen balance, and the markedly reduced arginine concentration in the muscle observed in rats fed -Arg and -Arg, Pro clearly indicate that arginine becomes a strictly essential amino acid in the rats with massive resection of the small intestine. However, sufficient proline can be synthesized from arginine in tissues such as the liver and kidney in the absence of the small intestine. Plasma glutamine, citrulline in the muscle and plasma, urinary excretion of orotic acid and nitrate (to assess nitric oxide formation from arginine) were also measured, and the changes in these metabolites are discussed.

Amino Acids↗

PubMed1994

Deficiency of endogenous arginine synthesis provokes hypertension by exhausting substrate arginine for nitric oxide synthesis.

Effect of deficiency in endogenous arginine synthesis was studied in connection with NO synthesis and blood pressure. Rats with massive resection of small intestine were fed an arginine-free diet (AF rats) for 24 days. Control rats were pair-fed an isonitrogenous and isocaloric arginine-replete diet. AF rats lost weight by a mean of 28 g whereas control rats kept original weight. Urinary excretion of nitrate and cGMP was reduced in AF rats by about 40% after the feeding. Blood pressure became elevated by 20-25 mmHg in AF rats after the feeding. The concentrations of arginine in muscle and plasma of AF rats were reduced to 17 and 39%, respectively, of control rats. AF rats may be a novel animal model for the in vivo study of NO.

Amino Acids↗