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1.
J Vasc Interv Radiol ; 21(7): 1066-70, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20537913

ABSTRACT

PURPOSE: To evaluate the efficacy of beta-irradiation therapy with rhenium 188 ((188)Re) mercaptoacetyltriglycine (MAG3)-filled balloon dilation to prevent neointimal hyperplasia after stent placement in a canine iliac artery model. MATERIALS AND METHODS: A total of 15 stents were implanted into the iliac arteries of eight dogs (one or two stents in each dog). Rhenium 188 MAG3-filled balloon dilation was performed immediately after placement of 10 bare stents-20 Gy in group II (n = 5) and 40 Gy in group III (n = 5)-and conventional balloon dilation was performed immediately after placement of the remaining five bare stents (group I). A follow-up angiogram was obtained 8 weeks after the procedure, and percentage of luminal stenosis was calculated for the proximal and distal ends of each stent. Neointimal thickening (expressed as the neointimal area divided by the sum of neointimal area and media area) was assessed for microscopic examination. RESULTS: All eight dogs survived until they were euthanized 8 weeks after the procedures. The mean luminal stenosis measurements at 8-week follow-up angiography in groups I, II, and III were 26.63%, -0.44%, and 10.53%, respectively. The mean neointimal thickening measurements in groups I, II, and III were 0.77, 0.21, and 0.34, respectively. The mean percentage of luminal stenosis and neointimal thickening differed significantly among the three groups (P < .05). CONCLUSIONS: beta-Irradiation with (188)Re-MAG3-filled balloon dilation has the potential to reduce neointimal hyperplasia secondary to stent placement in a canine iliac artery model. A dose of 20 Gy may be preferable versus a dose of 40 Gy to reduce neointimal hyperplasia.


Subject(s)
Graft Occlusion, Vascular/etiology , Graft Occlusion, Vascular/radiotherapy , Iliac Artery/radiation effects , Iliac Artery/surgery , Isotopes/therapeutic use , Rhenium/therapeutic use , Stents/adverse effects , Animals , Blood Vessel Prosthesis/adverse effects , Catheterization/methods , Disease Models, Animal , Dogs , Humans , Radiopharmaceuticals/therapeutic use , Treatment Outcome
2.
Neuroradiology ; 52(10): 883-91, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20091405

ABSTRACT

INTRODUCTION: The aim of this paper was to evaluate the angioarchitectural factors that can induce concurrent cavernous malformation (CM) in the territory of developmental venous anomaly (DVA). METHODS: From January 2006 to December 2007, 21 patients with 23 CMs in the territory of DVA were retrospectively analyzed (M; F = 12; 9, mean age = 53.3). Gadovist®-enhanced three-dimensional spoiled gradient-echo images on a 3 T magnetic resonance (MR) scanner were used. We investigated the presence of angioarchitectural factors: factor 1, the angulated course of curved medullary or draining vein in the distal portion of CM; factor 2, narrowing of distal draining vein; factor 3, severe medullary venous tortuosity. These were also analyzed for control group of 23 subjects (M; F = 11; 12, mean age = 46). RESULTS: Factor 1 was demonstrated in 22 cases (97%) and the CM occurred in a position of 90° or less of an abrupt angulated medullary or draining vein in 15 cases (65%) of the study group. Factor 2 was found in 13 cases (57%) with the diameter reduction of 50% or more in five cases. The mean ratio of diameter reduction was 0.53. Factor 3 was found in 17 cases (74%). Analyzing the independent factors, the p values for factors 1 and 3 were <.05, i.e., statistically significant. If combination of more than two factors was present, the p values for all the combinations were <0.05, i.e., statistically significant. CONCLUSION: Anatomical angioarchitectural factors might be the key factors in causing concurrent sporadic CM within the territory of DVA by causing disturbance of blood flow.


Subject(s)
Brain Neoplasms/complications , Brain Neoplasms/pathology , Cerebral Veins/abnormalities , Cerebral Veins/pathology , Hemangioma, Cavernous, Central Nervous System/pathology , Magnetic Resonance Imaging/methods , Adult , Aged , Female , Humans , Male , Middle Aged , Reproducibility of Results , Sensitivity and Specificity
3.
Eur Radiol ; 18(11): 2530-4, 2008 Nov.
Article in English | MEDLINE | ID: mdl-18523778

ABSTRACT

The purpose of this study was to evaluate the usefulness of a multifunctional gastrointestinal coil catheter for stent placement in 98 patients with colorectal strictures. The catheter was used in 98 consecutive patients for stent placement in the rectum (n = 24), recto-sigmoid (n = 13), sigmoid (n = 38), descending (n = 6), transverse (n = 11), splenic flexure (n = 3), hepatic flexure (n = 2), and ascending (n = 1) colon. The catheter was made of a stainless steel coil (1.3 mm in inner diameter), a 0.4-mm nitinol wire, a polyolefin tube, and a hemostasis valve. Usefulness of the catheter was evaluated depending on whether the catheter could pass a stricture over a guide wire and whether measurement of the stricture length was possible. The passage of the catheter over a guide wire beyond the stricture was technically successful and well tolerated in 93 (94.9%) of 98 patients. In the failed five patients, it was not possible to negotiate the guide wire due to presence of nearly complete small bowel obstruction. The average length of stricture was 6.15 cm (range, 3 cm to 20 cm) in patients with the colorectal stricture. There were no procedure-related complications. In conclusion, the multifunctional coil catheter seems to be useful in colorectal stent placement.


Subject(s)
Catheters, Indwelling , Intestinal Obstruction/diagnostic imaging , Intestinal Obstruction/surgery , Prosthesis Implantation/instrumentation , Stents , Adolescent , Adult , Aged , Aged, 80 and over , Colon/diagnostic imaging , Equipment Design , Equipment Failure Analysis , Female , Humans , Male , Middle Aged , Radiography , Rectum/diagnostic imaging , Retrospective Studies , Young Adult
4.
Mol Cell Biochem ; 314(1-2): 143-9, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18443742

ABSTRACT

Effects of the antibiotic novobiocin on the self-splicing of primary transcripts of the phage T4 thymidylate synthase gene (td) have been investigated. Novobiocin at 10 mM concentration inhibited the splicing by about 5% but at 40 mM concentration the splicing rate was inhibited by about 50%. The novobiocin inhibition of the self-splicing reaction was not reversed even at a high concentration (200 microM) of guanosine. However, increasing the Mg(2+) ion concentrations up to 20 mM almost fully restored the splicing activity to the normal splicing level. The double reciprocal plot analysis demonstrated that novobiocin acts as a mixed noncompetitive inhibitor for the td intron RNA with a K (i) of 90 mM. The splicing inhibition by novobiocin was strongly dependent on Mg(2+) ion concentration, indicating electrostatic interactions with the td intron RNA. It is likely that the antibiotic novobiocin may interfere with the catalytic actions of Mg(2+) ion in the splicing reaction of the td intron RNA.


Subject(s)
Bacteriophage T4/genetics , Novobiocin/pharmacology , RNA Splicing/drug effects , RNA, Catalytic/drug effects , Thymidylate Synthase/genetics , Down-Regulation/drug effects , Introns , Kinetics , Magnesium/pharmacology , Models, Biological , RNA, Catalytic/metabolism , RNA, Viral/genetics , RNA, Viral/metabolism , Time Factors
5.
Mol Cell Biochem ; 280(1-2): 17-23, 2005 Dec.
Article in English | MEDLINE | ID: mdl-16311901

ABSTRACT

The coenzyme pyridoxal phosphate and its analogs were tested for inhibition of the self-splicing of primary transcripts of the phage T4 thymidylate synthase gene (td). Of all compounds examined, the pyridoxal phosphate was the most potent inhibitor and the order of inhibitory efficiency for compounds tested was as follows: pyridoxal phosphate > pyridoxal > pyridoxine > pyridoxamine > pyridoxic acid. Increasing Mg2+ concentration up to 14 mM overcame the suppression of self-splicing by pyridoxal phosphate up to 95% of the level of normal splicing, implying its interference with effective catalysis of Mg2+. The kinetic analysis demonstrated that pyridoxal phosphate acts as a mixed type noncompetitive inhibitor for the td intron RNA with a K(i) of 11.8 mM. The specificity of the splicing inhibition by pyridoxal phosphate is predominantly due to increases in K(m) and decreases in V(max) values.


Subject(s)
Introns/genetics , Pyridoxal Phosphate/pharmacology , RNA Splicing/drug effects , Bacteriophage T4/enzymology , Kinetics , Magnesium/pharmacology , Pyridoxal Phosphate/chemistry , Thymidylate Synthase/antagonists & inhibitors , Thymidylate Synthase/genetics
6.
Mol Cells ; 19(2): 198-204, 2005 Apr 30.
Article in English | MEDLINE | ID: mdl-15879702

ABSTRACT

Both erythropoietin (EPO) and the short-form thrombopoietin (TPO) were expressed at low levels whereas the long-form TPO was expressed at high levels in transgenic animals. To elucidate the role of carboxy-terminal half of the long-form TPO which is absent in the short-form, we generated recombinant TPO or EPO expression vectors which contain or lack the carboxy-terminal half of TPO and examined their expression in the HC11 and 293 cells. The long-form TPO was expressed higher than the short-form regardless of the cell types, transfection modes, and promoters. When 3'-half of the long-form TPO cDNA was placed downstream of the EPO cDNA to act as a 3'-untranslated region, expression of EPO was moderately increased at the RNA level, however, no remarkable increase was observed at the protein level. These results suggest that the low expression of EPO, as like as the short-form TPO, is due to absence of the 3'-half in the full-length TPO that confers stability both at the RNA and protein levels.


Subject(s)
DNA, Complementary/metabolism , Erythropoietin/genetics , Mammary Glands, Animal/metabolism , RNA/metabolism , Thrombopoietin/genetics , 3' Untranslated Regions/genetics , 3' Untranslated Regions/metabolism , Animals , Caseins/genetics , Cells, Cultured , Cytomegalovirus/genetics , Enzyme-Linked Immunosorbent Assay , Erythropoietin/metabolism , Humans , Kidney/metabolism , Mammary Glands, Animal/cytology , Mice , Promoter Regions, Genetic/genetics , RNA Stability/physiology , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Reverse Transcriptase Polymerase Chain Reaction
7.
J Comput Assist Tomogr ; 28(3): 414-21, 2004.
Article in English | MEDLINE | ID: mdl-15100550

ABSTRACT

OBJECTIVE: To investigate the hemodynamic mechanism of pseudoaneurysm in the anterior communicating artery (AcoA) area in magnetic resonance (MR) angiography. METHODS: For the clinical study, a total of 62 patients who undertook digital subtraction angiography (DSA) because of the rupture of an aneurysm originating from a location other than the AcoA area were examined with MR angiography. The relation between signal defect at the AcoA in MR angiography and anatomic variation of the anterior cerebral artery (ACA) was evaluated. For the experimental study, MR angiography and DSA were performed on elastic silicon vascular phantoms with 2 different bifurcation angles (70 degrees and 140 degrees). Hemodynamic factors producing signal defects were evaluated, and the results were compared by computational fluid dynamics (CFD). RESULTS: In a clinical study, 21 of 62 patients had a hypogenetic A1 segment on either side of the ACA. Their MR angiography showed signal defects in the axilla area of the bifurcated AcoA complex in 14 patients, 7 of which could make the residual normal vessel seem to be an aneurysm. All the cases with an intact AcoA complex showed no signal defect. In an experimental study, MR angiography of vascular phantoms with broad-angle bifurcation (140 degrees) showed signal defects at the axilla areas of bifurcation, and these were shown as turbulent flow in DSA and CFD. Phantoms with narrow-angle bifurcation (70 degrees) did not show a significant signal defect, however. CONCLUSIONS: A hypoplastic A1 segment accompanying a broad bifurcation angle of the contralateral A1 segment may cause a pseudoaneurysm in MR angiography because of signal defect in the AcoA area.


Subject(s)
Aneurysm, False/diagnostic imaging , Cerebral Angiography/methods , Imaging, Three-Dimensional , Intracranial Aneurysm/diagnostic imaging , Magnetic Resonance Angiography/methods , Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Phantoms, Imaging
8.
Mol Cell Biochem ; 252(1-2): 285-93, 2003 Oct.
Article in English | MEDLINE | ID: mdl-14577604

ABSTRACT

The coenzyme NADP+ (nicotinamide adenine dinucleotide phosphate) and its analogs were tested for inhibition of the self-splicing of primary transcripts of the phage T4 thymidylate synthase gene (td). Of all compounds examined, the 3'-NADP was the most potent inhibitor and the order of inhibitory efficiency for compounds tested was as follows: 3'-NADP+ > NADP+ > NADP(+)-dialdehyde > NADPH > 1,N6-etheno-NADP+. Increasing guanosine concentration up to 40 microM overcame the suppression of self-splicing by NADP+ up to 76% of the level of normal splicing but didn't recover the full splicing activity. Similarly, Mg2+ also served to restore the splicing activity by about 90% at 25 mM concentration above which the splicing started to decline. The kinetic analysis showed that NADP+ acts as a mixed type non-competitive inhibitor for the td intron RNA with a Ki of 4.1 mM. The specificity of the splicing inhibition by NADP+ is predominantly due to increases in Km and decreases in kcat values. The results indicate that the inhibition by NADP+ was guanosine and Mg2+ dependent.


Subject(s)
NADP/pharmacology , RNA Splicing/drug effects , RNA, Catalytic/metabolism , Kinetics , Magnesium/pharmacology , RNA, Catalytic/genetics
9.
Phytochemistry ; 63(2): 209-15, 2003 May.
Article in English | MEDLINE | ID: mdl-12711143

ABSTRACT

The effects of individual soybean isoflavones, genistein (4',5,7-trihydroxyisoflavone) and daidzein (4',7-dihydroxyisoflavone), on tumor necrosis factor-alpha (TNF-alpha)-induced apoptosis and the production of local factors in osteoblastic cells has been investigated. Soybean isoflavones increased DNA synthesis and the number of viable cells. When cells were treated with TNF-alpha, the number of viable cells dose-dependently decreased. The decrease in cell number caused by TNF-alpha treatment was due to apoptosis, which was confirmed by TUNEL and cell death ELISA analyses. Soybean isoflavones inhibited apoptosis of osteoblastic cells subjected to TNF-alpha treatment. MC3T3-E1 osteoblastic cells secrete interleukin-6 (IL-6), interleukin-1beta (IL-1beta), nitric oxide (NO) and prostaglandin E(2) (PGE(2)) constitutively, but at low levels. Soybean isoflavones had no effect on the constitutive production of these local factors. When cells were treated with TNF-alpha (10(-10)M), the production of IL-6 and PGE(2), but not that of IL-1beta and NO, significantly increased. Treatment with soybean isoflavones (10(-5)M), in the presence of TNF-alpha (10(-10)M), for 48 h inhibited production of IL-6 and PGE(2), suggesting the antiresorptive action of soy phytoestrogen may be mediated by decreases in these local factors. The findings of this study thus suggest that soybean isoflavones may promote the function of osteoblastic cells and play an important role in bone remodeling.


Subject(s)
Apoptosis/drug effects , Dinoprostone/biosynthesis , Genistein/pharmacology , Glycine max/chemistry , Interleukin-6/biosynthesis , Isoflavones/pharmacology , Osteoblasts/drug effects , Osteoblasts/metabolism , Tumor Necrosis Factor-alpha/antagonists & inhibitors , 3T3 Cells , Animals , Cell Division/drug effects , Dinoprostone/antagonists & inhibitors , Enzyme-Linked Immunosorbent Assay , Estradiol/pharmacology , Fluorescent Antibody Technique/methods , Immunoassay , In Situ Nick-End Labeling/methods , Interleukin-1/biosynthesis , Interleukin-6/antagonists & inhibitors , Mice , Nitric Oxide/biosynthesis , Osteoblasts/cytology , Tumor Necrosis Factor-alpha/pharmacology
10.
Int J Biochem Cell Biol ; 35(2): 157-67, 2003 Feb.
Article in English | MEDLINE | ID: mdl-12479866

ABSTRACT

Effects of the coenzyme thiamine pyrophosphate and its analogs on the inhibition of self-splicing of primary transcripts of the phage T4 thymidylate synthase gene (td) were investigated. Of all compounds tested, the coenzyme thiamine pyrophosphate was the most potent inhibitor and the order of inhibitory efficiency for compounds tested was as follows: thiamine pyrophosphate>thiamine monophosphate>thiamine>thiochrome. Increasing guanosine concentration overcame the suppression of self-splicing by thiamine pyrophosphate close to the level of normal splicing. Kinetic analysis demonstrated that thiamine pyrophosphate acts as a competitive inhibitor for the td intron RNA with a Ki of 2.2mM. The splicing specificity inhibition by thiamine pyrophosphate is predominantly due to changes in Km.


Subject(s)
Introns , RNA Splicing/drug effects , Thiamine Pyrophosphate/pharmacology , Thiamine/analogs & derivatives , Bacteriophage T4/genetics , Dose-Response Relationship, Drug , Guanosine/metabolism , Guanosine/pharmacology , Kinetics , Magnesium/metabolism , Magnesium/pharmacology , RNA, Catalytic/drug effects , Thiamine/metabolism , Thiamine/pharmacology , Thiamine Monophosphate/metabolism , Thiamine Monophosphate/pharmacology , Thiamine Pyrophosphate/analogs & derivatives , Thiamine Pyrophosphate/metabolism , Thymidylate Synthase/genetics
11.
Mol Cells ; 14(2): 238-44, 2002 Oct 31.
Article in English | MEDLINE | ID: mdl-12442896

ABSTRACT

We investigated the effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the expression of synaptic proteins in dissociated E18 rat cortical cells. TCDD (0-50 nM) was added to plating media, and cell viability and expression of synaptic proteins were assayed on 4 and 7 days in vitro (DIV), respectively. TCDD had no apparent effect on early neurite outgrowth 12 h after plating. However, on 4 DIV, cell viability was reduced significantly, and neurons often revealed vacuoles in 20 or 50 nM culture and had limited secondary or higher order dendritic processes in 20 or 50 nM culture. Immunoblot analyses of cell homogenates indicated upregulation of NMDA receptor subunits (NR1, NR2A, and NR2B), but downregulation of synaptic organizing proteins (PSD-95, densin-180, and septin6 homologue) and a synapse-enriched enzyme (alphaCaMKII). Changes in the expression of synaptic proteins may be a underlying mechanism for altered synaptic transmission and neuropathy by TCDD.


Subject(s)
Cerebral Cortex/metabolism , Environmental Pollutants/pharmacology , Polychlorinated Dibenzodioxins/pharmacology , Synapses/metabolism , Animals , Cell Line , Environmental Pollutants/toxicity , In Vitro Techniques , Polychlorinated Dibenzodioxins/toxicity , Rats , Receptors, N-Methyl-D-Aspartate/biosynthesis , Receptors, N-Methyl-D-Aspartate/genetics , Synapses/drug effects
13.
Exp Mol Med ; 34(2): 107-13, 2002 May 31.
Article in English | MEDLINE | ID: mdl-12085985

ABSTRACT

Transformation with viral oncogene extends the lifespan of normal cells beyond replicative senescence called M1, but most of them eventually succumb to second crisis called M2 when telomeres become critically short. To acquire an infinite growth capacity, these cells have to overcome M2 crisis, which is known to follow telomerase activation. We have investigated if telomerase expression is required for virus-transformed pre-M2 cells to avert M2 crisis. Human retinal pigment epithelial (RPE) cells were transformed with simian virus 40 large T antigen and a VR3 clone in pre-M2 stage was obtained. Then, VR3 cells were transfected with a telomerase-containing vector and two cell lines that expressed telomerase temporarily or continuously were cloned and designated as ST1 and ST2, respectively. Normal RPE cells went into senescence after 36 population doublings. Although the lifespan was extended in the VR3 clone about 20 times more, it eventually underwent second crisis. The telomere length of VR3 decreased compared to that of normal RPE cells and the decrease continued during subculture. However, the ST1 and ST2 clones that expressed both T antigen and telomerase could avert this crisis. The initial telomere length of ST1 and ST2 was longer than that of normal cells. The ST1 underwent growth arrest again as telomerase expression faded out and elongated telomere was shortened, but the ST2 that maintained telomerase activity and telomere length proliferated continuously. In conclusion, telomerase activation is definitely required to overcome M2 crisis and acquire an infinite lifespan in human somatic epithelial cells and this mechanism is independent from M1 crisis escape in cell immortalization.


Subject(s)
Cell Transformation, Neoplastic , Mitosis , Pigment Epithelium of Eye/enzymology , Telomerase/physiology , Antigens, Viral, Tumor , Cell Death/physiology , Cell Line , Cell Transformation, Viral , Humans , Pigment Epithelium of Eye/cytology , Pigment Epithelium of Eye/pathology , Simian virus 40 , Telomerase/genetics , Telomere
14.
Int J Biochem Cell Biol ; 34(9): 1125-33, 2002 Sep.
Article in English | MEDLINE | ID: mdl-12009307

ABSTRACT

The stabilities of liver and pectoral muscle enzymes in 6-aminonicotinamide (6-AN) treated quail against heat treatment in the presence and absence of added ATP were investigated. Only ATP level in the brain and pectoral muscle of 6-AN treated group was significantly reduced compared to the control group whereas ADP and AMP levels were not affected. In the thermal stability (55 degrees C) of liver enzymes, the activity of acetylcholinesterase (AChE) was not affected whereas the activities of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and lactate dehydrogenase (LDH) were significantly lowered (P<0.01). The addition of 1mM ATP to liver enzyme extracts of 6-AN group afforded 4- and 1.7-fold more protection for GAPDH and LDH, respectively (P<0.01). In liver, LDH appeared to be more protected by ATP than GAPDH. In muscle, however, GAPDH and AChE activity were significantly affected but not LDH. The addition of 1mM ATP to muscle enzyme extracts of 6-AN group afforded 1.7-fold more protection for GAPDH (P<0.01) but rather inactivated AChE. A marked reduction in ATP levels in muscle did not affect specifically muscle enzyme activities only since liver enzyme activities were also affected to the same degree as muscle.


Subject(s)
6-Aminonicotinamide/pharmacology , Adenosine Triphosphate/metabolism , Liver/drug effects , Liver/enzymology , Muscle, Skeletal/drug effects , Muscle, Skeletal/enzymology , 6-Aminonicotinamide/administration & dosage , Acetylcholinesterase/metabolism , Adenosine Diphosphate/metabolism , Adenosine Monophosphate/metabolism , Animals , Brain/drug effects , Brain/metabolism , Coturnix , Enzyme Stability , Female , Glyceraldehyde-3-Phosphate Dehydrogenases/metabolism , Heart/drug effects , Hot Temperature , L-Lactate Dehydrogenase/metabolism , Myocardium/enzymology , Organ Size , Teratogens/pharmacology
15.
Int J Biochem Cell Biol ; 34(2): 204-10, 2002 Feb.
Article in English | MEDLINE | ID: mdl-11809423

ABSTRACT

The purification of a soluble acetylcholinesterase from Japanese quail brain using affinity chromatography on concanavalin A-Sepharose and edrophonium-Sepharose is described. The affinity matrix was synthesized by coupling an inhibitor edrophonium to epoxy-activated Sepharose. Acetylcholinesterase was purified 10,416-fold with a specific activity of 2500 U/mg protein. Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate and mercaptoethanol gave only one band with a molecular weight of 62.5 kDa. The molecular weight of the purified acetylcholinesterase was estimated to be 245.5 kDa by gel chromatography on Sephacryl S-200 under nondenaturing conditions. Based on the molecular weight obtained by both SDS-PAGE and gel filtration the purified acetylcholinesterase was assumed to be a tetrameric form.


Subject(s)
Acetylcholinesterase/isolation & purification , Brain/enzymology , Chromatography, Affinity/methods , Coturnix/metabolism , Acetylcholinesterase/chemistry , Acetylcholinesterase/metabolism , Animals , Chromatography, Gel , Electrophoresis, Polyacrylamide Gel , Molecular Weight
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