Images in cardiovascular medicine. Differential color imaging technique of helical CT angiography in the diagnosis of total anomalous pulmonary venous drainage.
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Biomedical subjects
Publications and source records attributed to Y Kato.
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The effect of extracellular matrix components on lipopolysaccharide-induced vascular endothelial cell injury was studied by using lipopolysaccharide-susceptible bovine aortic endothelial cells. For evaluation of lipopolysaccharide-induced injury, we estimated DNA synthesis and cell detachment of bovine aortic endothelial cells in cultures using extracellular matrix components-coated plastic dishes. Among extracellular matrix components, matrigel almost completely inhibited the reduction in DNA synthesis and the enhancement in cell detachment of bovine aortic endothelial cells in cultures with lipopolysaccharide. The lipopolysaccharide-induced injury was also inhibited by coating with type IV collagen, gelatin, fibronectin, laminin, vitronectin, and heparin sulphate proteoglycan. Extracellular matrix components capable of preventing lipopolysaccharide-induced bovine aortic endothelial cells injury coincidentally inhibited the phosphorylation of p38 mitogen-activated protein kinase in lipopolysaccharide-treated bovine aortic endothelial cells. SB203580, a specific inhibitor of p38 mitogen-activated protein kinase, also prevented the reduction in DNA synthesis and the enhancement in cell detachment of bovine aortic endothelial cells in cultures with lipopolysaccharide. It was therefore suggested that extracellular matrix components might protect bovine aortic endothelial cells from lipopolysaccharide-induced injury through inhibiting the activation of p38 mitogen-activated protein kinase.
Preservation by vitrification of Day 7 and Day 8 bovine blastocysts derived from nuclear transfer with cumulus cells was compared with preservation of in vitro fertilized blastocysts. In Experiment 1, embryos were vitrified in PBS containing 60% ethylene glycol. In Experiment 2, they were vitrified in combination with partial dehydration using a solution of 39% ethylene glycol + 0.7 M sucrose and 8.6% Ficoll. In Experiment 1, survival and hatching rates were 44 and 95% for nuclear transferred embryos, and 78 and 55% for in vitro fertilized embryos, respectively. In Experiment 2, survival and hatching rates were 93 and 95% for nuclear transfer embryos, and 77 and 85% for in vitro fertilized embryos, respectively. It is concluded that Day 7 and Day 8 bovine blastocysts derived from cumulus cells could be cryopreserved without the loss of viability by a simple and efficient method using a combination of partial dehydration and vitrification.
The sensitivity of the inner cell mass (ICM) and trophectoderm (TE) of mouse blastocysts to high temperatures was examined. When blastocysts with a diameter of 100 to 120 microm treated for 15 to 20 min at 45 degrees C were cultured in vitro, the cell number in the ICM did not increase, although that in the TE did increase. After transfer of treated blastocysts to recipients, implantation was not drastically inhibited but no live fetuses were obtained. These results demonstrated that the ICM at the blastocyst stage was more sensitive to high temperature than the TE. ICM clumps or ES cells were injected into blastocysts treated for 20 min at 45 degrees C. After transfer of injected blastocysts to recipients, we obtained mice derived completely from ICM or ES cells as judged by GPI analysis. Since 4 of 7 ES-cell derived mice, but none of the 6 mice derived from the ICM died after birth, an as yet unidentified epigenetic alteration might have occurred during the establishment and/or culture of ES cells.
The present study demonstrates that loss of cell adhesion potently promotes apoptosis in osteoclasts, a process termed "anoikis." When purified mature rabbit osteoclasts were cultured on plastic for 18 h, about 25% of them were spontaneously committed to apoptosis. The death rate increased more than twofold, after osteoclasts were subjected to suspension culture in inverted Terasaki plates. The osteoclast anoikis was significantly prevented by bongkrekic acid, an inhibitor of mitochondrial permeability transition (PT), and z-VAD-FMK, a caspase inhibitor, suggesting involvement of mitochondrial PT and caspase activation in the death process. Colony-stimulating factor-1 (CSF-1), receptor activator of NF-kappaB ligand (RANKL), and calcitonin protected adherent osteoclasts, but not floating osteoclasts from anoikis. These data show that adhesion is a primary requirement for osteoclast survival.
Dystrobrevin is a newly discovered dystrophin-associated protein that is classified as alpha- and beta-dystrobrevin. Previous studies reported that dystrophin, utrophin, syntrophin and beta-dystroglycan were expressed in the cerebellum. In the present study, we examined cellular and subcellular localization of dystrobrevin in the adult rat cerebellum immunohistochemically. Confocal microscopy showed that dystrobrevin was expressed around blood vessels and under the pia mater as dystrophin, utrophin and beta-dystroglycan were. Immunoelectron microscopy demonstrated that dystrobrevin was localized not only in the astrocytic endfeet around blood vessels and under the pia mater, but also in endothelial cells. Considering the fact that dystrobrevin possesses multiple phosphotyrosine kinase residues, these data suggest that dystrobrevin plays a role in blood-brain barrier functions as a component of the dystrophin complex.
A laser self-focused channel formation into overdense plasmas was observed using a soft x-ray laser probe system with a grid image refractometry (GIR) technique. 1.053 &mgr;m laser light with a 100 ps pulse duration was focused onto a preformed plasma at an intensity of 2x10(17) W/cm (2). Cross sections of the channel were obtained which show a 30 &mgr;m diameter in overdense plasmas. The channel width in the overdense region was kept narrow as a result of self-focusing. Conically diverging density ridges were also observed along the channel, indicating a Mach cone created by a shock wave due to the supersonic propagation of the channel front.
BACKGROUND: Large discrepancies have been found between Western and Japanese pathologists in the diagnosis of adenoma/dysplasia versus carcinoma for gastric and colorectal glandular lesions. It is important to determine whether similar differences exist in the diagnosis of esophageal squamous lesions. METHODS: Eleven expert gastrointestinal pathologists from Japan, North America, and Europe individually reviewed a set of microscopic slides containing 21 sections of biopsies and corresponding endoscopic mucosal resection specimens from Japanese patients with superficial esophageal squamous neoplastic lesions. The pathologists indicated the pathologic findings on which they based each diagnosis. RESULTS: Invasion was the most important diagnostic criterion of carcinoma for the Western pathologists whereas nuclear and structural features were more important for the Japanese pathologists. For two sections showing low grade dysplasia according to most Western pathologists, the Japanese pathologists diagnosed suspected carcinoma in one case and definite carcinoma in the other. For nine sections with high grade dysplasia according to the Western pathologists, the Japanese pathologists diagnosed suspected carcinoma in two cases and definite carcinoma in seven cases. For six sections with suspected carcinoma according to most Western pathologists, the Japanese pathologists diagnosed suspected carcinoma in one case and definite carcinoma in five cases. Four sections showed definite carcinoma according to both the Western and Japanese pathologists. Thus, there was agreement among the Western and Japanese pathologists for only 5 of the 21 sections (kappa value, 0.04). However, when high grade dysplasia, noninvasive carcinoma, and suspected carcinoma were grouped together, the agreement was excellent (19 of the 21 sections; kappa value, 0.75). CONCLUSIONS: In Japan, esophageal squamous cell carcinoma is diagnosed mainly based on nuclear criteria, even in cases judged to be noninvasive low grade dysplasia in the West. This difference in diagnostic practice may contribute to the relatively high incidence rate and good prognosis of superficial esophageal carcinoma in Japan. To improve the comparability of research data, the authors recommend that high grade dysplasia, noninvasive carcinoma, and suspected carcinoma be grouped together into one category of "noninvasive high grade neoplasia." [See editorial on pages 969-70, this issue.]
The effects of nine methylsulfonyl (MeSO(2)) metabolites of tetra-, penta- and hexachlorinated biphenyls (tetra-, penta- and hexaCBs; 20 micromol/kg once daily for 4 days) on the hepatic microsomal UDP-glucuronosyltransferase (UDP-GT) were investigated in male Sprague-Dawley rats. Each of the seven 3-MeSO(2)-PCBs, 3-MeSO(2)-2, 2',4',5-tetraCB (3-MeSO(2)-CB49), 3-MeSO(2)-2,3',4',5-tetraCB (3-MeSO(2)-CB70), 3-MeSO(2)-2,2',3',4',5-pentaCB (3-MeSO(2)-CB87), 3-MeSO(2)-2,2',4',5,5'-pentaCB (3-MeSO(2)-CB101), 3-MeSO(2)-2,2',3', 4',5,6-hexaCB (3-MeSO(2)-CB132), 3-MeSO(2)-2,2',3',4',5,5'-hexaCB (3-MeSO(2)-CB141), 3-MeSO(2)-2,2',4',5,5',6-hexaCB (3-MeSO(2)-CB149) and 4-MeSO(2)-2,2',4',5,5'-pentaCB (4-MeSO(2)-CB101) increased the activities of UDP-GT toward chloramphenicol, 4-nitrophenol and 4-methylumbelliferone. 4-MeSO(2)-2,2',4',5,5',6-hexaCB (4-MeSO(2)-CB149) increased the activity of UDP-GT toward chloramphenicol (UGT2B1) but not toward 4-nitrophenol (UGT1A6) and 4-methylumbelliferone (UGT1A6). The activity of UDP-GT toward thyroxine (T(4)) significantly increased after the administration of each of the seven 3-MeSO(2)-PCBs and 4-MeSO(2)-CB101. Significant correlation was found between the activity of UDP-GT toward T(4) and serum total T(4) concentration after the administration of each of the MeSO(2) derivatives except 4-MeSO(2)-CB149. In conclusion, seven 3-MeSO(2)-PCBs and 4-MeSO(2)-CB101 induce both UGT2B1 and UGT1A6, and 4-MeSO(2)-CB149 induces UGT 2B1. The results from the present study indicate that increase in the hepatic T(4) glucuronidation after the administration of the seven 3-MeSO(2)-PCBs and 4-MeSO(2)-CB101 possibly because of the induction of both UGT1A1 and UGT1A6 caused the reduction of serum T(4) levels.
A novel dehydratase that catalyzes the stoichiometric dehydration of Z-phenylacetaldoxime to phenylacetonitrile has been purified 483-fold to homogeneity from a cell-free extract of Bacillus sp. strain OxB-1 isolated from soil. It has a M(r) of about 40 000 and is composed of a single polypeptide chain with a loosely bound protoheme IX. The enzyme is inactive unless FMN is added to the assay, but low activity is also observed when sulfite replaces FMN. The activity in the presence of FMN is enhanced 5-fold under anaerobic conditions compared to the activity measured in air. The enzyme has maximum activity at pH 7.0 and 30 degrees C, and it is stable at up to 45 degrees C at around neutral pH. The aerobically measured activity in the presence of FMN is also enhanced by Fe(2+), Sn(2+), SO(3)(2)(-), and NaN(3). Metal-chelating reagents, carbonyl reagents, electron donors, and ferri- and ferrocyanides strongly inhibit the enzyme with K(i) values in the micromolar range. The enzyme is active with arylalkylaldoximes and to a lesser extent with alkylaldoximes. The enzyme prefers the Z-form of phenylacetaldoxime over its E-isomer. On the basis of its substrate specificity, the enzyme has been tentatively named phenylacetaldoxime dehydratase. The gene coding for the enzyme was cloned into plasmid pUC18, and a 1053 base-pair open reading frame that codes for 351 amino acid residues was identified as the oxd gene. A nitrilase, which participates in aldoxime metabolism in the organism, was found to be coded by the region just upstream from the oxd gene. In addition an open reading frame (orf2), whose gene product is similar to bacterial regulatory (DNA-binding) proteins, was found just upstream from the coding region of the nitrilase. These findings provide genetic evidence for a novel gene cluster that is responsible for aldoxime metabolism in this microorganism.
The frequency of K-ras mutation in biliary duct carcinomas in different locations and the relationship to the form of the junction of the pancreaticobiliary duct (JPBD) are not understood clearly. These points were investigated in the present study. Thirty-seven biliary duct carcinomas in patients without anomalous JPBD were investigated for K-ras mutations. Regarding location, 12 were hilar, 4 in the upper, 11 in the middle, and 10 in the lower portion of the duct. Furthermore, with 14 cases for which the form of the JPBD could be confirmed by endoscopic retrograde cholangiopancreatography or postoperative cholangiopancreatography, division was made into two types: those with a long common channel (>5 mm) in the papilla of Vater (type 1, n = 4), and the other with a shorter or nonapparent common channel (type 2, n = 10). The overall frequency of K-ras mutation was 30%, the incidence gradually increasing from upper to lower regions. K-ras mutations were significantly more frequent in biliary duct carcinomas associated with long common channels (P < 0.05). These results suggest that a long common channel may bear a relation to K-ras mutations in biliary duct carcinogenesis, presumably through its influence on pancreatic juice regurgitation.
Long-scale jetlike x-ray emission was observed in a 100-TW laser-plasma interaction. The jet was well collimated with a divergence of 30-40 mrad and continued from the target surface into underdense regions for a distance over 4 mm in the specular direction of the laser light. A two-dimensional particle-in-cell simulation shows an electron acceleration with the specularly reflected laser light and collimation of the electron stream by a self-generated magnetic field, resulting in the electron jet to the direction of the specularly reflected light.
A novel gene, klotho (kl), which is involved in the development of a syndrome resembling human aging in mice, was recently identified. The kl gene encodes a single-pass membrane protein whose extracellular domain carries homology to beta-glucosidases. There also exists a splice variant of kl mRNA which encodes a putative secreted protein in both human and mouse. In this study, to characterize the physiological roles of Klotho protein, we established three monoclonal antibodies (mAbs) against the recombinant human Klotho protein. The mAbs are named KM2076 (rat IgG(2)a), KM2119 (rat IgG(2)b), and KM2365 (mouse IgG(1)). In Western blots, KM2076 and KM2119 specifically recognized a 130 kDa Klotho protein in the mouse and human kidney membrane fractions. To detect the human Klotho protein, the sandwich-type ELISA system with KM2076 and KM2365 was established. Using the ELISA system, we detected the human Klotho protein as low as 20 ng/ml in the supernatant of Chinese hamster ovary cells (CHO cells), introduced the human klotho gene. KM2076 and KM2119 specifically gave a positive staining by immunohistochemical staining in paraffin or frozen sections of the kidneys from wild-type mice but not in those from kl mice. Strong staining was observed especially in cortical renal tubules of the mouse kidney, where expression of klotho transcripts overlaps. KM2076 also showed a similar reaction pattern in the paraffin sections of rat and human kidneys. The mAbs established in this paper will serve as useful analytical, pathological, and diagnostic tools to disclose the role of Klotho protein in the suppression of a syndrome resembling human aging.
OBJECTIVES: To examine the possible correlation between the amount of antigen and the level of soluble tumor necrosis factor receptor (sTNFR), and to assess its biologic significance in allergic reactions. DESIGN: Randomized control trial. SUBJECTS: Twelve volunteers with Japanese cedar pollinosis and 10 healthy volunteers. INTERVENTIONS: The levels of p55 sTNFR (sTNFR1) and p75 sTNFR (sTNFR2) in samples of serum and nasal epithelial lining fluid (ELF) from 12 subjects with pollinosis and 10 healthy subjects were measured 4 times (preseason, early season, midseason, and postseason) in low (total, 415/cm( 2) per season) and high (total, 19,935/cm(2) per season) pollen-count periods, and the results were compared among the 4 groups. RESULTS: In the low-pollen-count period, increased levels of sTNFR1 and sTNFR2 were observed in ELF samples from the allergic subjects during the midseason. In contrast, in the high-pollen-count period, those levels were already elevated during the preseason and reduced during the midseason. Especially, the levels of sTNFR2 in ELF samples from the allergic subjects during the midseason in the high-pollen-count period were significantly lower than those in the low-pollen-count period. Moreover, a significant negative correlation (sTNFR1, R = -0.82; sTNFR2, R = -0. 73) was found between the levels of sTNFR1 and sTNFR2 in ELF samples and the scores of symptoms in the allergic subjects in the high-pollen-count period, but not in the low-pollen-count period. CONCLUSION: In patients with pollinosis, the amounts of antigen regulate the local levels of sTNFRs, possibly inhibiting nasal allergic inflammation.
To clarify whether the neovasculature of brain tumors preserves blood-brain barrier (BBB) functions, we studied the expression of a tight junction-related protein, Zo-1, using immunohistochemistry. Twenty-six astrocytic tumors were examined using an anti-Zo-1 Mab, and Zo-1 expression was compared with the expression of vasicular endothelial growth factor (VEGF), vascular endothelial growth factor receptor (VEGFR) (fit-1), and antiproliferative cell nuclear antigen (PCNA). A positive reaction for Zo-1 was seen in the endothelial cells in micro-blood vessels in all astrocytic tumors. The reactions for Zo-1 in the endothelial cells forming glomeruloid proliferations in newly formed micro-blood vessels in high-grade tumors were weaker than those in the endothelial cells of normal cerebral capillaries. Although there is a negative correlation between positive immunoreactions for BBB-related proteins and the expression of VEGF of the endothelial cells in micro-blood vessels, the proliferative activity of tumor cells, and histological grades, the present findings suggest that the endothelial cells of the neovasculature of high-grade tumors preserve partial BBB function at the cellular level. Because of the ease of immunohistochemical procedures compared with electron microscopic examination, the immunohistochemical detection of Zo-1 should provide a useful marker for tight junctions.
Production of SPARC/osteonectin/BM-40 was determined in mouse B16 melanoma clones BL6 and F10 (high metastatic) and F1 (low metastatic). SPARC was produced greater amount in BL6 and F10 than in F1 cells, showing a good agreement with their metastatic potentials. Moreover, SPARC production was not influenced by culture pH, even in the acidic conditions (= pH 5.9). Although tumor tissues show often low pH due to excessive amount of acidic metabolites such as lactate, most studies have been done in neutral pH. High SPARC production in the acidic medium, therefore, is thought to be an important potential for tumor invasive behaviour.
We studied the effect of treatment with recombinant human GH in an anemic patient with panhypopituitarism in which hemoglobin (Hb) concentration remained as low as 11.0 g/dl in spite of appropriate replacement with thyroid and adrenocortical hormones. Recombinant human GH was subcutaneously and constantly infused for 12 months using a portable syringe pump at a rate of 0.25 U/kg/week. After the treatment with human GH plasma erythropoietin (EPO) levels increased from 12.2 to 25.1 mIU/ml, with a concomitant increase of Hb concentration to 13.6 g/dl. When the administration of human GH was interrupted, both plasma EPO levels and Hb concentrations decreased. There was a close correlation between plasma GH and EPO levels before and during the human GH administration (y=2.444x+1 3.423, r=0.641, p<0.05). Plasma GH levels were well correlated with Hb concentrations before and during human GH administration (y=0.529x+11.313, r=0.690, p<0.01). Plasma IGF4 levels were also correlated with Hb concentrations (y=0.007x+10.874, r=0.832, p<0.001), but not with plasma EPO levels. These findings suggest that GH treatment may be useful in anemic patients with panhypopituitarism.
Interleukin-2 production may be one of the underlying causes of Wiskott-Aldrich syndrome immunodeficiency and recombinant interleukin-2 administration (or an infusion of T-cells expanded by CD3 stimulation and rIL-2) is able, to some extent, to restore defective T-cell function.