576
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Suzuki Y, Hinoshita H, Yokoyama K, Yamada A, Ogura Y, Mimura N, Yoshinaga H. [Histopathological assessment of renal biopsy specimens of subjects with urine abnormality]. NIHON JINZO GAKKAI SHI 1995; 37:284-90. [PMID: 7609327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Between April 1985 and April 1992, 25,672 men (age 47 +/- 9 years, mean +/- SD) and 9,791 women (48 +/- 9 years) underwent mass urinalysis in the Center for Adult Complete Physical Examination in our hospital. The results revealed proteinuria in 6.3% of the men and 4.4% of the women and hematuria in 17.4% of the men and 37.8% of the women. Thirty-five subjects with asymptomatic persistent proteinuria and/or hematuria identified as a result of follow-up testing by the nephrologists at our hospital underwent renal biopsy. All of the biopsy specimens obtained were examined by light microscopy, fluorescence microscopy and electron microscopy. Histopathological findings in the biopsy specimens from these 35 subjects were as follows: One case (3%) of chronic pyelonephritis, 11 cases (31%) of IgA nephropathy, 4 cases (11%) of IgA nephropathy (severe type), 5 cases (14%) of membranous nephropathy, 4 cases (11%) of thin basement membrane disease (TMD), 7 cases (28%) of benign nephrosclerosis and 3 cases (9%) of minor glomerular abnormality. Light microscopy, fluorescence microscopy and electron microscopy for histopathological assessment of renal specimens, especially for the diagnosis of TDM, which was not uncommon, were indispensable tools in our study. Moreover, it is essential for proteinuria and hematuria to be tested simultaneously using the same standard method in all the urine specimens collected.
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577
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Mitaka C, Hirata Y, Ichikawa K, Uchida T, Yokoyama K, Nagura T, Tsunoda Y, Amaha K. Effects of nitric oxide synthase inhibitor on hemodynamic change and O2 delivery in septic dogs. THE AMERICAN JOURNAL OF PHYSIOLOGY 1995; 268:H2017-23. [PMID: 7539593 DOI: 10.1152/ajpheart.1995.268.5.h2017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
To elucidate the role of nitric oxide (NO) in septic shock, we measured hemodynamic and pulmonary gas changes in anesthetized dogs after intravenous administration of bacterial lipopolysaccharide (LPS) with or without NO synthase inhibitor, NG-nitro-L-arginine (L-NNA). Infusion of LPS (250 ng.kg-1.min-1) for 2 h decreased mean arterial pressure over 1-4 h. Although L-NNA (10 mg/kg) blocked LPS-induced hypotension, it decreased cardiac index, oxygen delivery index, arterial pH, and arterial PO2 and increased systemic vascular resistance index in the presence or absence of LPS. Administration of NG-nitro-D-arginine (D-NNA, 10 mg/kg) alone caused fewer hemodynamic effects (increased systemic vascular resistance index and decreased cardiac index) than L-NNA alone. Our study provides evidence that L-NNA prevents endotoxin-induced hypotension but decreases cardiac output and oxygen delivery, effects that may, in part, be due to a nonspecific NO synthase-independent event. Thus clinical use of NO synthase inhibitors for the treatment of septic shock should be cautiously considered.
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578
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Yokoyama K, Itoman M, Shindo M, Kai H. Contributing factors influencing type III open tibial fractures. THE JOURNAL OF TRAUMA 1995; 38:788-93. [PMID: 7760410 DOI: 10.1097/00005373-199505000-00019] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Ninety-five patients with severe open tibial fractures (96 fractures) were treated with nonoperative treatment alone (NO group, n = 16), immediate internal fixation (I group, n = 22), delayed internal fixation (D group, n = 34), or external fixation (EF group, n = 24). The D group was divided into a delayed internal fixation group following nonoperative treatment (D1 group, n = 14), and a delayed internal fixation group following external fixation (D2 group, n = 20). Using the classification system of Gustilo, there were 43 type IIIA, 42 type IIIB, and 11 type IIIC open tibial fractures. There were 17 deep infections (type IIIA, n = 3; IIIB, n = 12; IIIC, n = 2). The difference in the deep infection rate (DIR) between the type IIIA and type IIIB fractures was statistically significant (7.0% vs. 28.0%, p < 0.05). The DIRs in groups NO, I, D1, D2, and EF were 12.5, 27.3, 7.1, 35, and 4%, respectively. There was a significant difference in DIR between the D2 group and the EF group. The DIR in the D (D1 + D2) group and group I showed no significant difference. There was no relationship between the DIR and either Injury Severity Score or skin closure time. The authors of this study, therefore, do not feel there is an advantage to immediate internal fixation over delayed procedures for Gustilo type III open fractures of the tibia. However, careful attention must be given to the application of delayed internal fixation, especially intramedullary nailing, after external fixation.
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579
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Komori T, Takato T, Yokoyama K. Integration of dental models in a three-dimensional replica. J Oral Maxillofac Surg 1995; 53:621-4. [PMID: 7722737 DOI: 10.1016/0278-2391(95)90081-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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580
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Noguchi M, Minami M, Earashi M, Taniya T, Miyazaki I, Mizukami Y, Nonomura A, Nishijima H, Takanaka T, Kawashima H, Saito Y, Takashima C, Nakamura S, Michigishi T, Yokoyama K. Pathologic Assessment of Surgical Margins on Frozen and Permanent Sections in Breast Conserving Surgery. Breast Cancer 1995; 2:27-33. [PMID: 11091529 DOI: 10.1007/bf02966893] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The diagnostic value of frozen section was evaluated in the histologic assessment of surgical margins obtained by wide excision of breast tumors. There were 87 patients with unilateral breast cancer, and 5 with bilateral breast cancers. The periphery of the excised breast tissue was peeled like an orange and histologically examined by frozen and permanent section. If either in situ or infiltrating microscopic tumor was found at the margin, it was considered positive. Using frozen sections, the margin was judged histologically positive or suspicious in 30 tumors (31%) and negative in 67(69%) tumors. Positive surgical margins were histologically confirmed by permanent section in 20(67%) of the 30 tumors diagnosed as positive or suspicious on frozen section. Another 10 tumors had negative margins. In 4 tumors, however, while the initial or re-excised margin was negative on frozen section, the margins were positive by permanent section. These surgical margins were positive due exclusively to the presence of ductal carcinoma in situ (DCIS). Evaluation of surgical margins in breast cancer by frozen section, thus exhibited a diagnostic accuracy of 86&prtcnt;, a sensitivity of 83%, and a specificity of 86%. It is concluded that frozen sections are useful in the determination of involvement of surgical margins after the wide excision of breast cancer. It must be pointed out that frozen sections will ofter overestimate involvement of the surgical margins.
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581
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Li HO, Tang X, Kitabayashi I, Gachelin G, Chiu R, Yokoyama K. Induction by adenovirus-5 E1A of the differentiation phenotype of F9 teratocarcinoma cells involves a conserved region (CR1) of E1A. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1266:148-56. [PMID: 7742380 DOI: 10.1016/0167-4889(95)00010-p] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The effects of the E1A protein of adenovirus-5 on the differentiation program of F9 teratocarcinoma cells were examined by the stable introduction of plasmids that expressed wild-type or mutated forms of E1A. Constitutive expression of plasmids for most of the mutant E1As induced loss of expression of the cell-surface antigen SSEA-1 and the enhanced expression of genes specific for the differentiated phenotype of F9 cells, such as genes for laminin B1, tissue-type plasminogen activator (tPA) and type IV collagen, as well as the altered cell morphology that is associated with the differentiated state. However, such changes were not observed in the case of genes for mutant proteins from which a conserved region (CR1) of E1A had been deleted. Furthermore, no significant induction of expression of the c-jun gene or transactivation of the c-jun-CAT reporter gene were observed when the sequence that encodes CR1 of E1A had been deleted. A palindromic sequence element (DRE) of the c-jun promoter was essential for the E1A-mediated up-regulation of the c-jun gene. These results imply that CR1 is required for activation of the c-jun gene and that it is implicated in the growth arrest, expression of parietal endoderm-specific functions and the orderly differentiation of F9 cells.
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582
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Hyder SM, Nawaz Z, Chiappetta C, Yokoyama K, Stancel GM. The protooncogene c-jun contains an unusual estrogen-inducible enhancer within the coding sequence. J Biol Chem 1995; 270:8506-13. [PMID: 7721748 DOI: 10.1074/jbc.270.15.8506] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Estrogens have previously been shown to induce c-jun mRNA levels in target cells during hormone induced proliferation, and this appears to be a primary hormonal response involving transcriptional activation. In this report we have now identified an estrogen dependent enhancer within the coding sequence of c-jun. This element has the sequence GCAGAnnnTGACC which is identical to the consensus estrogen response element GGTCAnnnTGACC in the second half site, but varies considerably in the first half site. Synthetic oligodeoxynucleotides containing this jun sequence bind the estrogen receptor in cell-free studies using a competitive band shift assay with the consensus element. The jun element also confers hormone inducibility to reporter plasmids in yeast and mammalian based transcriptional systems. Structure-function studies illustrate that the TGACC half-site and its immediate flanking dinucleotides, but not the GCAGA half-site, are required for estrogen receptor binding. In contrast, both the GCAGA and TGACC half-sites are obligatory for hormone-inducible transcriptional activation. These results suggest a model in which the estrogen receptor functions as a heterodimer to regulate transcription of the c-jun protooncogene. Coupled with reports of estrogen response elements in c-fos and estrogenic induction of c-fos and c-jun in vivo, these findings also support a role for AP-1 components as early response genes in estrogen-induced proliferation.
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583
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Yokoyama K. [Spinal anesthesia for an emergency surgery in a patient with right sided heart failure]. MASUI. THE JAPANESE JOURNAL OF ANESTHESIOLOGY 1995; 44:566-569. [PMID: 7776524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A 79-year-old female with a pace maker implanted because of complete A-V block associated with right sided heart failure was scheduled for the emergency repair of incarcerated abdominal wall hernia. Spinal anesthesia for the surgery and epidural catheterization for postoperative pain control were performed. Anesthesia and postoperative course were uneventful. The effects of spinal anesthesia on cardiovascular system are the result of preganglionic sympathetic block produced by the local anesthetic agent injected in the subarachnoid space. It is, therefore, desirable to consider the cardiovascular effects of spinal anesthesia (reduction of afterload and preload) on a patient who has right sided heart failure. Post operative pain control by PCA pump is also a basic method for a patient with right sided heart failure.
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584
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Komai S, Toyama H, Takeuchi A, Yokoyama K, Koga S. [Quantitative analysis of individual renal function using 99mTc-DMSA scintigram--comparison with 131I-OIH renogram]. KAKU IGAKU. THE JAPANESE JOURNAL OF NUCLEAR MEDICINE 1995; 32:427-33. [PMID: 7776550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
99mTc-2,3-di-mercapto-succinic acid (DMSA) is able to be used for the quantitative analysis of individual renal function by calculating the uptake ratio. The purpose of this study is to assess the clinical feasibility of DMSA uptake ratio as compared with 131I-ortho-iodo-hippuran (OIH) renogram pattern. Two hundred eleven cases (191 patients, 1 to 87 years old) with renal disorders and 4 normal volunteers (27.8 +/- 2.4 years old) were studied. Just prior to the DMSA study in the same day, OIH renogram was carried out. They were divided into 6 types by OIH renogram patterns. In 24 cases of normal renogram pattern and normal blood data who were defined as the normal group and 4 normal volunteers, DMSA uptake ratio showed negative correlation with increasing age (r = 0.61, p < 0.05). Patients of the severe impaired functioning and the non functioning patterns showed significantly decreased DMSA uptake ratios as compared with the normal pattern. There was also a significant difference in DMSA uptake between impaired functioning patterns. Compensative hemi-hypertrophy kidneys showed significantly higher DMSA uptake ratios than those of atrophic kidneys. The possibility of the quantitative analysis of the functional compensation was presumed. In conclusion, quantitative analysis of individual renal function using DMSA uptake ratio is considered to be useful to evaluate the renal functional reserve.
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585
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Yokoyama K, Hattori T. [Characteristics and development of stump cancers of the stomach]. NIHON SHOKAKIBYO GAKKAI ZASSHI = THE JAPANESE JOURNAL OF GASTRO-ENTEROLOGY 1995; 92:761-8. [PMID: 7739127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
To clarify characteristics and development of stump cancers of the stomach, we studied 10 cases (12 lesions) of them with mucin-histochemical and immunohistochemical techniques and gene analysis using polymerase chain reaction. Sixty-seven % of the cancers were mostly composed of gastric-type cells and 67% also showed abnormal accumulation of p53 protein in their nuclei. There were scattered cells with abnormal accumulation of p53 protein in cystically dilated glands that were often found to be surrounding cancers. Immunohistochemistry of proliferating cell nuclear antigen also demonstrated proliferating activity of these cystic glands. It is suggested that the cystically dilatated gland is precancerous lesion of stump cancers of the stomach. The gene analysis showed less occurrence of K-ras abnormality, and the mutation of APC gene is suggested to be infrequent.
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586
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Shuke N, Tonami N, Takahashi I, Kameyama T, Yokoyama K, Kinuya S, Nakajima K, Aburano T, Michigishi T, Hisada K. Prominent uptake of Tl-201 by duodenal leiomyosarcoma after exercise myocardial perfusion study. Clin Nucl Med 1995; 20:299-301. [PMID: 7788983 DOI: 10.1097/00003072-199504000-00002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Thallium-201 SPECT performed preoperatively for the evaluation of myocardial ischemia in a 72-year-old man with duodenal leiomyosarcoma demonstrated prominent focal uptake in the abdomen. Comparing a transaxial slice of SPECT through the abdominal uptake to the CT scan, the uptake was confirmed to be corresponding to the tumor. The tumor was delineated clearly, in good contrast to the surrounding normal intestine, which showed far less Tl-201 uptake than the tumor. In the delayed SPECT performed 3 hours after injection, although the intestinal activity became perceptible, the tumor still could be differentiated from the surrounding normal intestine. In this case, the exercise might be attributable to the initial low Tl-201 uptake by the normal intestine, which might otherwise have been an obstacle to Tl-201 scintigraphy for abdominal tumor detection. This case suggests the use of exercise for avoiding unfavorable intestinal activity, and the possibility of Tl-201 SPECT for abdominal tumor imaging.
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587
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588
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Takano M, Yokoyama K, Yayama K, Okamoto H. Murine fibroblasts synthesize and secrete kininogen in response to cyclic-AMP, prostaglandin E2 and tumor necrosis factor. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1265:189-95. [PMID: 7696348 DOI: 10.1016/0167-4889(94)00218-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Fibroblasts prepared from the meninges of newborn mice or from mouse embryos, as well as fibroblast L929 cells, secreted an immunoreactive material (ir-kininogen) against rabbit anti-mouse low-molecular-weight kininogen antibody in response to dibutyryl cAMP. Western blots using a bradykinin-directed monoclonal, as well as a polyclonal anti-mouse low-molecular-weight kininogen antibody, showed that ir-kininogen had a molecular weight of 80,000 and that it contained a kinin moiety. N-terminal amino acid sequence of the ir-kininogen was consistent with that of mouse L-kininogen. The ir-kininogen produced by fibroblasts released a kinin by incubating with trypsin and mouse submandibular gland kallikrein, and it was identified as bradykinin by means of high-performance liquid chromatography, indicating that mouse fibroblasts produce and secrete a kininogen. Forskolin, prostaglandin E2 and tumor necrosis factor alpha stimulated the production of ir-kininogen by meningeal fibroblasts, whereas neither dibutyryl cAMP nor these agents influenced kininogen production by mouse hepatocytes in primary cultures. These results demonstrated that fibroblasts are a source of kininogen in the mouse, and that it is regulated by the inflammatory mediators, prostaglandin E2 and tumor necrosis factor. Therefore locally produced kininogen is implicated in pathogenesis of inflammation.
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589
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Yasumoto K, Yokoyama K, Shibata K, Tomita Y, Shibahara S. Microphthalmia-associated transcription factor as a regulator for melanocyte-specific transcription of the human tyrosinase gene. Mol Cell Biol 1995; 15:1833. [PMID: 7862173 PMCID: PMC230408 DOI: 10.1128/mcb.15.3.1833] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
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590
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Kimura Y, Hamamoto K, Suzuki K, Yokoyama K, Hisada K, Kasagi K, Konishi J, Ichiya Y, Masuda K, Kubo A. [Phase II clinical trial of the radioactive strontium (89Sr) chloride agent, SMS. 2P for pain palliation in patients with prostate cancer with bone metastases]. KAKU IGAKU. THE JAPANESE JOURNAL OF NUCLEAR MEDICINE 1995; 32:311-21. [PMID: 7537834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The phase II clinical trial of a strontium (89Sr) chloride agent (SMS. 2P) was performed in 9 patients with painful bone metastases secondary to prostate cancer. After an intravenous administration, 89Sr circulated in the plasma and was rapidly cleared. Urinary excretion varied widely among the patients. No serious acute side effects were observed. A mild transient increase in pain was reported by 4 patients 2-4 days after administration, two of whom complained of mild nausea or vomiting. All symptoms improved and never became a clinical problem. There were some abnormal hematological parameters. In particular, a decrease in the platelet level seemed to be a marrow suppression due to 89Sr irradiation. It is difficult to discriminate between the effects of 89Sr and the progress of the disease using tumor markers. The pain level improved within 2 weeks after administration and the effect continued for at least 8 weeks, which improved the quality of life for these patients.
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591
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Yokoyama K, Hayashi NR, Arai H, Chung SY, Igarashi Y, Kodama T. Genes encoding RubisCO in Pseudomonas hydrogenothermophila are followed by a novel cbbQ gene similar to nirQ of the denitrification gene cluster from Pseudomonas species. Gene 1995; 153:75-9. [PMID: 7883189 DOI: 10.1016/0378-1119(94)00808-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The cbbL and cbbS genes, encoding ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO), were cloned and sequenced from a thermophilic hydrogen-oxidizing bacterium, Pseudomonas hydrogenothermophila strain TH-1. The cbbL gene encoded a 474-amino-acid (aa) protein (53,285 Da); cbbS encoded a 124-aa protein (14,656 Da). An ORF found downstream from the cbbLS genes encoded a 267-aa protein (29,565 Da) which had no similarity to cbbX located downstream from cbbLS from Alcaligenes eutrophus and Xanthobacter flavus. This gene, called cbbQ, was highly similar to the nirQ gene of the denitrification gene cluster from P. aeruginosa and P. stutzeri.
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592
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Sasaki H, Hirabayashi Y, Ishibashi T, Inoue T, Matsuda M, Kai S, Ikuta K, Yokoyama K, Yokota T, Maruyama Y. Effects of erythropoietin, IL-3, IL-6 and LIF on a murine megakaryoblastic cell line: growth enhancement and expression of receptor mRNAs. Leuk Res 1995; 19:95-102. [PMID: 7869746 DOI: 10.1016/0145-2126(94)00121-p] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We examined the effects of recombinant human erythropoietin (rhEPO), recombinant murine interleukin 3 (rmIL-3), recombinant human interleukin 6 (rhIL-6), recombinant human interleukin 11 (rhIL-11), recombinant murine leukemia inhibitory factor (rmLIF) and recombinant murine granulocyte-macrophage colony-stimulating factor (rmGM-CSF) on the growth of murine megakaryocytic cell lines. In serum-free methylcellulose culture supplemented with bovine serum albumin (BSA), the addition of rhEPO (0.1-10 U/ml), rmIL-3 (10-500 U/ml), rhIL-6 (100-10,000 U/ml), rmLIF (100-10,000 U/ml), or rmGM-CSF (10-1000 U/ml) enhanced colony growth in L8057Y5 cells, which had been maintained in protein-free culture, mostly in a dose-dependent fashion; rhIL-11 did not have any stimulatory effect at the tested doses (10-1000 U/ml). In addition, colony growth of L8057 cells, which had been maintained in serum-containing culture, was enhanced, but to a lesser extent, by the addition of these cytokines except rhEPO (the cultures were supplemented with 1% fetal bovine serum. Among the cytokines that showed growth-enhancing effects on L8057 cells, the expression of mRNAs encoding receptors for EPO, IL-6 and IL-3 was examined by northern blot analysis or reverse transcription polymerase chain reaction (RT-PCR). In both cell lines, mRNAs for EPO-R, IL-6R, gp130, IL-3R alpha and beta chains were constitutively expressed. The results suggest that L8057 and L8057Y5 cell lines have characteristics of megakaryoblastic cells in their biological responses to cytokines, as well as in the expression of cytokine receptor mRNAs, and that the growth-enhancing effects of these cytokines on the cell lines may be achieved through specific receptors. Our findings show the value of these cell lines for investigating the mechanisms of growth signal transduction in megakaryopoiesis.
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593
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Miyai A, Yamauchi A, Nakanishi T, Sugita M, Takamitsu Y, Yokoyama K, Itoh T, Andou A, Kamada T, Ueda N. Na+/myo-inositol cotransport is regulated by tonicity in cultured rat mesangial cells. Kidney Int 1995; 47:473-80. [PMID: 7536857 DOI: 10.1038/ki.1995.60] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Mesangial cells are considered to be faced with osmotic stress under physiological (such as extraglomerular mesangial cells) and pathophysiological (for example, diabetes mellitus) conditions. To see if mesangial cells have an osmoregulatory mechanism, like renal medullary cells, we measured the intracellular contents of organic osmolytes in isotonic and hypertonic conditions. Cultured rat mesangial cells are well tolerant of acute increase in osmolality up to 500 mOsm/kg. The myo-inositol content increased in hypertonic cells more than six-fold the value in isotonic cells. The contents of glycerophosphorylcholine and sorbitol also increased but were less than that of myo-inositol. The Na(+)-dependent myo-inositol uptake in hypertonic cells was a 12-fold uptake in isotonic cells, reaching a maximum 24 hours after the switch to a hypertonic medium. The uptake rate increased as medium osmolality increased from 300 to 500 mOsm/kg. Raffinose is the most effective solute to increase the myo-inositol uptake. NaCl, glucose and mannitol also increased the uptake rate (NaCl > glucose > mannitol). The increased uptake by hypertonicity was the result of an increase in Vmax without change in Km and was dependent on RNA and protein synthesis. These results indicate that mesangial cells respond to extracellular hypertonicity by increasing myo-inositol transport activity and accumulating myo-inositol into the cells, suggesting that myo-inositol functions as an organic osmolyte in mesangial cells.
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594
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Tonami N, Nakajima K, Yokoyama K, Shuke N, Taki J, Kinuya S, Michigishi T, Hisada K, Kobayashi K. Variable portal circulation from inferior mesenteric vein assessed by per-rectal radionuclide administration. Nucl Med Commun 1995; 16:92-8. [PMID: 7731624 DOI: 10.1097/00006231-199502000-00006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The intrahepatic distribution of radioactivity after the per-rectal administration of 201T-chloride and/or 99Tcm-pertechnetate was investigated in 177 studies in 149 patients with no liver disease or diffuse liver disease and compared with that of 99Tcm-stannous (99Tcm-Sn) colloid scintigrams. The patients were classified into two groups: distribution of intrahepatic radioactivity of 201Tl and/or 99Tcm-pertechnetate scintigrams similar to (homogeneous) or different from (heterogeneous) that of 99Tcm-Sn-colloid scintigrams. The heterogeneous group was divided into three subgroups: increased radioactivity of the right lobe (right dominant pattern), increased radioactivity of the left lobe (left dominant pattern) and uneven distribution of radioactivity in both lobes (uneven pattern). Of the 80 patients in whom the studies were performed in the supine position at rest, 14 (17.5%) showed a heterogeneous pattern (8 right dominant, 4 left dominant, 2 uneven) and 66 (82.5%) a homogeneous pattern. In the 97 patients allowed free body movement, 6 (6.2%) showed a heterogeneous (1 right dominant, 5 left dominant) and 91 (93.8%) a homogeneous pattern. A significant difference in the incidence of heterogeneous distribution between the resting and free body movement groups was found (P < 0.05). One patient with a left dominant pattern after free body movement with 201Tl showed a right dominant pattern at rest in the 99Tcm-pertechnetate study. It is concluded that a heterogeneous intrahepatic distribution of inferior mesenteric vein blood is sometimes observed and that the distribution of portal vein blood flow seems to be affected by the patient's positioning and free body movement.
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595
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Yokoyama K, McGeady P, Gelb MH. Mammalian protein geranylgeranyltransferase-I: substrate specificity, kinetic mechanism, metal requirements, and affinity labeling. Biochemistry 1995; 34:1344-54. [PMID: 7827082 DOI: 10.1021/bi00004a029] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Protein geranylgeranyltransferase-I (PGGT-I) catalyzes the transfer of the 20-carbon prenyl group from geranylgeranyl pyrophosphate to the cysteine residue near the C-termini of a variety of eukaryotic proteins. Kinetic analysis of homogenous PGGT-I from bovine brain reveals that the reaction follows a sequential pathway in which either prenyl donor or acceptor can bind first to the enzyme and that the reaction operates at steady-state rather than at rapid equilibrium. Substrate inhibition by prenyl acceptor but not by prenyl donor suggests that geranylgeranyl pyrophosphate binding first to free enzyme is the kinetically preferred pathway. This is supported by isotope trapping experiments which show that the ternary complex goes on to products faster than the release of geranylgeranyl pyrophosphate from the complex. The KM for the interaction of geranylgeranyl pyrophosphate with PGGT-I is markedly affected by the structure of the prenyl acceptor bound to the enzyme. A detailed analysis of the substrate specificity of PGGT-I reveals that peptides which contain a C-terminal leucine are preferred (kcat/KM = 1-5 x 10(5) M-1 s-1) to those that end in serine (kcat/KM = 2-4 x 10(3) M-1 s-1) or phenylalanine (kcat/KM = 0.5 x 10(3) M-1 s-1). PGGT-I also catalyzes the farnesylation of peptides that have a C-terminal leucine; kcat for farnesylation and KM for farnesyl pyrophosphate are similar to those for geranylgeranylation, but the KM for the peptide is 30-fold higher. Geranyl pyrophosphate is utilized by PGGT-I but is a poor substrate. Optimal activity of PGGT-I is obtained in the presence of micromolar amounts of Zn2+ and mM amounts of Mg2+. Mn2+ or Cd2+ but not Co2+ can substitute for Zn2+ and for Mg2+. Metals are not required for tight-binding of geranylgeranyl pyrophosphate to PGGT-I, and the measured dissociation equilibrium constant for this binary complex is 16 nM. Photoaffinity analogues of geranylgeranyl pyrophosphate and farnesyl pyrophosphate were prepared and shown to exclusively label the beta-subunit. The implication of the results for the substrate specificity of protein prenylation in cells is briefly discussed.
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596
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Ishibashi T, Yokoyama K, Shindo J, Hamazaki Y, Endo Y, Sato T, Takahashi S, Kawarabayasi Y, Shiomi M, Yamamoto T. Human granulocyte-macrophage colony-stimulating factor lowers the levels of plasma cholesterol with an increase in mRNA for very low density lipoprotein receptor in rabbits. Ann N Y Acad Sci 1995; 748:630-3. [PMID: 7695219 DOI: 10.1111/j.1749-6632.1994.tb17377.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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597
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Mitsubayashi K, Dicks JM, Yokoyama K, Takeuchi T, Tamiya E, Karube I. A flexible biosensor for glucose. ELECTROANAL 1995. [DOI: 10.1002/elan.1140070110] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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598
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Nagata R, Yokoyama K, Clark SA, Karube I. A glucose sensor fabricated by the screen printing technique. Biosens Bioelectron 1995; 10:261-7. [PMID: 7755958 DOI: 10.1016/0956-5663(95)96845-p] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A novel glucose sensor employing ferrocene-modified glucose oxidase is fabricated using the screen printing technique. Glucose oxidase is covalently bound to the electron mediator ferrocenecarboxylic acid in order to obtain higher enzyme activity. The ferrocene-glucose oxidase shows an increased catalytic current because the ferrocene acts as an electron transfer relay between the active centre of the enzyme and the gold electrode. Glucose sensors employing enzymes modified with ferrocene in various ways are successfully fabricated using the screen printing technique. The ink component containing the ferrocene-glucose oxidase is specially developed to be applicable to the printing machine. The printed glucose sensor chip offers a stable calibration profile and stable electrochemical properties.
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599
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Liu L, Jang GF, Farnsworth CC, Yokoyama K, Glomset JA, Gelb MH. Synthetic prenylated peptides: studying prenyl protein-specific endoprotease and other aspects of protein prenylation. Methods Enzymol 1995; 250:189-206. [PMID: 7651150 DOI: 10.1016/0076-6879(95)50072-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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600
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Okuyama M, Kubota I, Miura T, Nagamine S, Yokoyama K. Anomalous origin of the right coronary artery from the left ventricle in an adult. JAPANESE HEART JOURNAL 1995; 36:115-8. [PMID: 7760508 DOI: 10.1536/ihj.36.115] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A 64-year-old woman was referred to cardiac surgery because of aortic stenosis. At surgery, it was confirmed that the right coronary artery arose from the pars membranacea of the left ventricle 5 mm beneath the commissure between the right coronary and noncoronary cusps.
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