Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 58
Filter
1.
Oral Dis ; 23(8): 1127-1133, 2017 Nov.
Article in English | MEDLINE | ID: mdl-28650084

ABSTRACT

OBJECTIVE: This study aimed to identify and quantify polyomaviruses (BKPyV and JCPyV) in the saliva, mouthwash, blood and urine of liver pretransplant patients. MATERIALS AND METHODS: A case-control study was performed using a convenience sample of 21 end-stage liver disease patients (EG = experimental group) and 20 normoreactive controls (CG = control group). In total, 162 samples were collected. Detection and quantification of polyomaviruses were performed using real-time PCR method. RESULTS: In the EG, 21 samples (25%) were positive for BKPyV and 10 (11.90%) for JCPyV, while in the CG, 27 samples (34.61%) were positive for BKPyV and six (7.69%) for JCPyV. With regard to the number of samples positive for BKPyV and JCPyV, there was no statistically significant difference between EG and CG (p = .52 and p = .25). In the EG, we observed a panorama similar to that of the CG regarding the presence of polyomaviruses in mouthwash, blood and urine. The greatest difference between the samples was that regarding the identification of BKPyV in saliva. CONCLUSION: Cirrhotic patients on the liver transplant waiting list did not show higher prevalence of BKPyV and JCPyV compared to normoreactive controls.


Subject(s)
BK Virus/isolation & purification , JC Virus/isolation & purification , Polyomavirus Infections/virology , Saliva/virology , Tumor Virus Infections/virology , Adult , Blood/virology , Case-Control Studies , End Stage Liver Disease/surgery , Female , Humans , Liver Transplantation , Male , Middle Aged , Preoperative Period , Urine/virology , Viral Load
2.
Acta Radiol ; 44(2): 185-92, 2003 Mar.
Article in English | MEDLINE | ID: mdl-12694106

ABSTRACT

PURPOSE: To evaluate step-table 3D contrast-enhanced (CE) MRA with bolus chasing for the detection and grading of stenoses in patients with peripheral vascular disease (PVD) of the lower extremities. MATERIAL AND METHODS: Fifty patients were studied by step-table bolus-chasing 3D-CE-MRA and i.a. DSA within 24 h. After determination of the individual circulation time, CE-MRA was performed during power injection of 40 ml of Gd-DTPA. To cover the whole range between the renal arteries and the feet with three slab locations, the scanner table was manually advanced twice for 350 mm. Total imaging time was 1 min 23 s. The degree of stenosis and image quality of the images were evaluated by 2 observers. In addition, a treatment plan was established based on the 3D-CE-MRA and DSA investigations. RESULTS: In 44 of 50 patients (88%), the visualization of the arterial tree from the renal arteries to the foot was possible. Forty-six of 50 patients (92%) had good or very good image quality. In the calf, 3D-CE-MRA was superior to DSA in 6 patients. For the detection of stenosis >50%, sensitivity was 99.5%, specificity 98.8%, positive predictive value 95.6% and the negative predictive value 99.8%. Cohen's kappa for 3D-CE-MRA vs. DSA was 0.926; for interobserver agreement it was 0.96. CONCLUSION: Bolus-chasing 3D-CE-MRA with manual table movement is a simple, robust and easy to perform technique which provides high quality angiograms of the lower extremity arterial system and is comparable to, i.a., DSA for the diagnosis of PVD.


Subject(s)
Contrast Media , Leg/blood supply , Leg/diagnostic imaging , Magnetic Resonance Angiography/methods , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Radiography
3.
Plant Cell ; 12(11): 2283-94, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11090225

ABSTRACT

Segregation analysis between Lysopersicon esculentum (cultivated tomato) and L. hirsutum (wild form) in conjunction with positional verification by using near-isogenic lines demonstrated that biosynthesis of two structurally different classes of sesquiterpenes in these species is controlled by loci on two different chromosomes. A locus on chromosome 6, Sesquiterpene synthase1 (Sst1), was identified for which the L. esculentum allele is associated with the biosynthesis of beta-caryophyllene and alpha-humulene. At this same locus, the L. hirsutum allele is associated with biosynthesis of germacrene B, germacrene D, and an unidentified sesquiterpene. Genomic mapping, cDNA isolation, and heterologous expression of putative sesquiterpene synthases from both L. esculentum and L. hirsutum revealed that Sst1 is composed of two gene clusters 24 centimorgans apart, Sst1-A and Sst1-B, and that only the genes in the Sst1-A cluster are responsible for accumulation of chromosome 6-associated sesquiterpenes. At a second locus, Sst2, on chromosome 8, the L. hirsutum allele specified accumulation of alpha-santalene, alpha-bergamotene, and beta-bergamotene. Surprisingly, the L. esculentum allele for Sst2 is not associated with the expression of any sesquiterpenes, which suggests that cultivated tomato may have a nonfunctional allele. Sesquiterpene synthase cDNA clones on chromosome 6 do not cross-hybridize on genomic DNA gel blots with putative sesquiterpene synthases on chromosome 8, an indication that the genes in Sst1 and Sst2 are highly diverged, each being responsible for the biosynthesis of structurally different sets of sesquiterpenes.


Subject(s)
Sesquiterpenes/metabolism , Solanum lycopersicum/metabolism , Amino Acid Sequence , Base Sequence , Chromatography, Gas , DNA Primers , Escherichia coli/enzymology , Escherichia coli/genetics , Isoenzymes/chemistry , Isoenzymes/genetics , Isoenzymes/metabolism , Solanum lycopersicum/enzymology , Solanum lycopersicum/genetics , Magnetic Resonance Spectroscopy , Molecular Sequence Data , Pyrophosphatases/chemistry , Pyrophosphatases/genetics , Pyrophosphatases/metabolism , Sequence Homology, Amino Acid , Species Specificity
5.
Proc Natl Acad Sci U S A ; 97(12): 6902-7, 2000 Jun 06.
Article in English | MEDLINE | ID: mdl-10829071

ABSTRACT

1-O-beta-acyl acetals serve as activated donors in group transfer reactions involved in plant natural product biosynthesis and hormone metabolism. However, the acyltransferases that mediate transacylation from 1-O-beta-acyl acetals have not been identified. We report the identification of a cDNA encoding a 1-O-beta-acylglucose-dependent acyltransferase functioning in glucose polyester biosynthesis by Lycopersicon pennellii. The acyltransferase cDNA encodes a serine carboxypeptidase-like protein, with a conserved Ser-His-Asp catalytic triad. Expression of the acyltransferase cDNA in Saccharomyces cerevisiae conferred the ability to disproportionate 1-O-beta-acylglucose to diacylglucose. The disproportionation reaction is regiospecific, catalyzing the conversion of two equivalents of 1-O-beta-acylglucose to 1, 2-di-O-acylglucose and glucose. Diisopropyl fluorophosphate, a transition-state analog inhibitor of serine carboxypeptidases, inhibited acyltransferase activity and covalently labeled the purified acyltransferase, suggesting the involvement of an active serine in the mechanism of the transacylation. The acyltransferase exhibits no carboxypeptidase activity; conversely, the serine carboxypeptidases we have tested show no ability to transacylate using 1-O-acyl-beta-glucoses. This acyltransferase may represent one member of a broader class of enzymes recruited from proteases that have adapted a common catalytic mechanism of catabolism and modified it to accommodate a wide range of group transfer reactions used in biosynthetic reactions of secondary metabolism. The abundance of serine carboxypeptidase-like proteins in plants suggests that this motif has been used widely for metabolic functions.


Subject(s)
Acyltransferases/physiology , Carboxypeptidases/physiology , Glucose/metabolism , Acyltransferases/genetics , Amino Acid Sequence , Carboxypeptidases/antagonists & inhibitors , Cathepsin A , Cloning, Molecular , Isoflurophate/pharmacology , Molecular Sequence Data , Molecular Weight , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae Proteins
6.
Invest Radiol ; 35(2): 97-104, 2000 Feb.
Article in English | MEDLINE | ID: mdl-10674453

ABSTRACT

RATIONALE AND OBJECTIVES: To evaluate neointimal hyperplasia, plaque distribution, and morphologic features of peripheral arterial stent-grafts with intravascular ultrasound (IVUS). METHODS: Twenty-three patients with stenoses or occlusions of the pelvic or femoral arteries were treated with 31 stent-grafts. Angiography and IVUS of the stented artery were performed 13.9 +/- 9.7 months after stent implantation. Maximum in-stent restenosis was measured by IVUS. Plaque composition and lesion topography were also assessed. RESULTS: The maximum in-stent restenosis was 53.2 +/- 26.5% for the femoral and 14.2 +/- 10.1 for pelvic arterial stent-grafts. Predilection sites of maximum neointimal tissue accumulation were the edges of the femoral stent-grafts. Only small amounts of neointimal hyperplasia were found in the stent-graft edges. No predilection site for maximum in-stent restenosis was found for the pelvic arterial stent-grafts. CONCLUSIONS: Predilection sites of maximum in-stent restenosis were the edges of femoral stent-grafts in contrast to pelvic stent-grafts. Femoral stent-grafts showed significantly higher graded stenoses with IVUS than iliac stent-grafts. The authors' findings at IVUS did not change the treatment plan in these patients treated with stent-grafts.


Subject(s)
Arterial Occlusive Diseases/diagnostic imaging , Arterial Occlusive Diseases/surgery , Blood Vessel Prosthesis , Graft Occlusion, Vascular/diagnostic imaging , Stents , Ultrasonography, Interventional , Female , Humans , Male , Middle Aged , Recurrence
7.
Plant Physiol ; 122(1): 275-82, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10631271

ABSTRACT

Short- and medium-chain-length fatty acids (FAs) are important constituents of a wide array of natural products. Branched and straight short-chain-length FAs originate from branched chain amino acid metabolism, and serve as primers for elongation in FA synthase-like reactions. However, a recent model proposes that the one-carbon extension reactions that utilize 2-oxo-3-methylbutyric acid in leucine biosynthesis also catalyze a repetitive one-carbon elongation of short-chain primers to medium-chain-length FAs. The existence of such a mechanism would require a novel form of regulation to control carbon flux between amino acid and FA biosynthesis. A critical re-analysis of the data used to support this pathway fails to support the hypothesis for FA elongation by one-carbon extension cycles of alpha-ketoacids. Therefore, we tested the hypothesis experimentally using criteria that distinguish between one- and two-carbon elongation mechanisms: (a) isotopomer patterns in terminal carbon atom pairs of branched and straight FAs resulting from differential labeling with [(13)C]acetate; (b)(13)C]threonine labeling patterns in odd- and even chain length FAs; and (c) differential sensitivity of elongation reactions to inhibition by cerulenin. All three criteria indicated that biosynthesis of medium-chain length FAs is mediated primarily by FA synthase-like reactions.


Subject(s)
Fatty Acids/biosynthesis , Carbon Isotopes , Cerulenin/chemistry , Cerulenin/pharmacology , Fatty Acids/chemistry , Fatty Acids/metabolism , Gas Chromatography-Mass Spectrometry , Solanaceae/metabolism
8.
Rofo ; 172(12): 985-91, 2000 Dec.
Article in German | MEDLINE | ID: mdl-11199442

ABSTRACT

PURPOSE: The value of DSA for the measurement of aortic and peripheral arterial aneurysm dimensions before endovascular treatment is limited by projection effects. It was evaluated if additional gadolinium-enhanced three-dimensional MR angiography (3D-CEMRA) could compensate for the disadvantages of DSA. MATERIALS AND METHODS: 21 patients with 35 aneurysms in the abdominal aorta (14), iliac (9) and femoropopliteal vessels (12) were assessed with DSA (7 with calibrated catheter, 14 with yardstick) and 3D-CEMRA (TR/TE 7.8/2.1 ms, flip-angle 40 degrees, Matrix 512 x 224, FOV 500 mm, eff. slice 1.8 mm). We measured and compared aneurysm dimensions on both modalities. 3D-CEMRA was regarded as the reference method to evaluate the dimension of DSA-projection effects. RESULTS: Diameter and length of aneurysms were underestimated on DSA with the yardstick as reference. The deviation ranged from 15% (+/- 5%) in the aorta to 21% (+/- 10%) in the iliac vessels. Only with calibrated catheters as reference (7/21 DSA), were the distances on DSA correlated well with MRA. In 2/35 aneurysms 3D-CEMRA detected thrombosis with difference between length of inner lumen dilatation on DSA and whole aneurysm length. 2/5 accessory renal arteries found on DSA were not detected on 3D-CEMRA. CONCLUSIONS: 3D-CEMRA is a valuable adjunct to DSA for pre-interventional diagnostics of aortic and peripheral arterial aneurysms. It provides exact evaluation of aneurysm dimensions and information about partial thrombosis.


Subject(s)
Aneurysm/diagnosis , Aortic Aneurysm, Abdominal/diagnosis , Iliac Aneurysm/diagnosis , Magnetic Resonance Angiography/methods , Peripheral Vascular Diseases/diagnosis , Aneurysm/diagnostic imaging , Aneurysm/therapy , Angiography , Aortic Aneurysm, Abdominal/diagnostic imaging , Aortic Aneurysm, Abdominal/therapy , Calibration , Contrast Media , Femoral Artery , Humans , Iliac Aneurysm/diagnostic imaging , Iliac Aneurysm/therapy , Peripheral Vascular Diseases/diagnostic imaging , Peripheral Vascular Diseases/therapy , Popliteal Artery , Renal Artery , Reproducibility of Results , Sensitivity and Specificity
9.
Rofo ; 171(2): 143-8, 1999 Aug.
Article in German | MEDLINE | ID: mdl-10506889

ABSTRACT

PURPOSE: To investigate frequency of acetabular labral lesions in elderly hip joints, and to determine sensitivity and specificity of MR arthrography (MRa) for the detection of these abnormalities. MATERIALS AND METHODS: Twenty cadaveric hip joints were examined by MRa. For MRa, 15 ml of a solution of iodinated contrast solution (Solutrast 300) and Gd-DTPA (100:1) were injected under fluoroscopic guidance. MR imaging was performed on a 1.5 T MR scanner (Vision, Siemens; FOV 16 cm, matrix 256 x 256, fat-suppressed 3D-FLASH). Multiplanar image reconstructions were done perpendicular to the acetabulum in the oblique-coronal, oblique-axial, and radial planes. The labral specimens were examined macroscopically. RESULTS: In 12/20 hips (60%), a labral lesion was found on pathologic examination. In 7 specimens, the labrum was partially or completely detached in the weight-bearing superior region. One flap-like variant of the labrum was seen; in 4 hip joints, the labrum was degenerated (one cystic degeneration). Pathologic findings were confirmed by MRa in 8/12 specimens (sensitivity 67%). All degenerated labra were correctly diagnosed on MRa. Three small labral detachments and the flap-like variant were misinterpreted as being normal. There were no false positive findings (specificity 100%). The accuracy was 80%. Labral lesions were seen in 6/8 and in 6/12 of hips with and without osteoarthritis, respectively. CONCLUSION: MRa is well suited to delineate the acetabular labrum and to diagnose labral abnormalities. Detection of small labral detachments and anatomic variants is difficult and requires some experience. Labral lesions are correlated to osteoarthritis of the hip, but may be frequently seen in the elderly without underlying osteoarthritis.


Subject(s)
Acetabulum/pathology , Hip Joint/pathology , Magnetic Resonance Imaging , Acetabulum/diagnostic imaging , Aged , Aged, 80 and over , Cadaver , Contrast Media , Female , Gadolinium DTPA , Hip Joint/diagnostic imaging , Humans , Iopamidol , Magnetic Resonance Imaging/methods , Male , Middle Aged , Radiography , Sensitivity and Specificity
10.
Plant Physiol ; 121(2): 453-60, 1999 Oct.
Article in English | MEDLINE | ID: mdl-10517836

ABSTRACT

Glandular trichomes of the wild tomato species Lycopersicon pennellii secrete 2,3,4-O-tri-acyl-glucose (-Glc), which contributes to insect resistance. A Glc acyltransferase catalyzes the formation of diacyl-Glc by disproportionating two equivalents of 1-O-acyl-beta-Glc, a high-energy molecule formed by a UDP-Glc dependent reaction. The acyltransferase was purified 4,900-fold from L. pennellii leaves by polyethylene glycol fractionation, diethylaminoethyl chromatography, concanavalin A affinity chromatography, and chromatofocusing. The acyltransferase possesses an isoelectric point of 4.8, a relative molecular mass around 110 kD, and is composed of 34- and 24-kD polypeptides as a heterotetramer. The 34- and 24-kD proteins were partially sequenced. The purified enzyme catalyzes both the disproportionation of 1-O-acyl-beta-Glcs to generate 1,2-di-O-acyl-beta-Glc and anomeric acyl exchange between 1-O-acyl-beta-Glc and Glc.


Subject(s)
Acetates/metabolism , Acyltransferases/metabolism , Glucose/analogs & derivatives , Solanum lycopersicum/enzymology , Acyltransferases/chemistry , Acyltransferases/isolation & purification , Amino Acid Sequence , Chromatography, Affinity , Chromatography, Ion Exchange , Electrophoresis, Polyacrylamide Gel , Indicators and Reagents , Kinetics , Molecular Sequence Data , Peptide Fragments/chemistry , Peptide Fragments/isolation & purification
11.
Radiology ; 212(2): 371-7, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10429692

ABSTRACT

PURPOSE: To evaluate the efficacy of contrast material-enhanced magnetic resonance (MR) angiography for the diagnosis of peripheral arterial occlusion and follow-up after stent placement. MATERIALS AND METHODS: Sixty-seven patients (21 women, 46 men; mean age, 64.6 years) were examined. Digital subtraction angiography and contrast-enhanced MR angiography were performed in 28 patients for preinterventional evaluation of iliofemoral arterial occlusion and in 39 patients for follow-up after stent placement in the iliac or femoral arteries, which had been performed several months before. RESULTS: All 24 occlusions were correctly diagnosed with contrast-enhanced MR angiography. Of the 59 stenoses, 36 were greater than 50% and 23 were 50% or less. Sensitivity and specificity for the detection of stenoses greater than 50% were 100% and 83%, respectively. Patency of the different stents was determined correctly with contrast-enhanced MR angiography. Some stents caused signal intensity dropout, which made MR evaluation of stents difficult. Generally, these signal intensity artifacts were most severe in stainless steel stents and mild in some nitinol stents. CONCLUSION: Contrast-enhanced MR angiography is comparable to digital subtraction angiography for the detection of stenosis greater than 50% and occlusion in the iliofemoral arteries. Stent patency can be determined, but contrast-enhanced MR angiography is not suitable for stent evaluation owing to signal intensity dropout; however, it provides information about the vascular anatomic areas proximal and distal to the stent.


Subject(s)
Arterial Occlusive Diseases/diagnosis , Arterial Occlusive Diseases/therapy , Femoral Artery , Iliac Artery , Magnetic Resonance Angiography , Stents , Angiography, Digital Subtraction , Arterial Occlusive Diseases/diagnostic imaging , Contrast Media , Female , Gadolinium DTPA , Humans , Injections, Intravenous , Male , Middle Aged , Prospective Studies , Sensitivity and Specificity , Vascular Patency
12.
Scand J Work Environ Health ; 25(1): 67-74, 1999 Feb.
Article in English | MEDLINE | ID: mdl-10204673

ABSTRACT

OBJECTIVES: Several cross-sectional studies have described a decrease in the expiratory flow rates of divers. The objective of this study was to determine whether the combined application of high-resolution computed tomography (HRCT) and lung function testing supports the reported development of small airway obstruction in divers. METHODS: Thirty-two navy divers, 27 commercial divers, and 48 referents matched for age and smoking history underwent pulmonary function testing and HRCT of the lungs supplemented by a limited number of expiratory scans. The commercial divers were older and dived longer than the navy divers. Multivariate regression analysis was used to assess the relevant correlations of age, height, pack-years of cigarette smoking, and indices of diving exposure with lung function parameters. RESULTS: The inspiratory vital capacity and forced vital capacity (FVC) were greater, while the FEV% [(100 x FEV10)FVC] and maximum expiratory flow (MEF) at 25% (MEF25) of the FVC were lower for the navy divers than for the referents. The lung volumes and expiratory airflow pattern did not differ between the commercial divers and the corresponding referents. The forced expiratory volume in 1 second (FEV10), FEV%, MEF75, and MEF25 correlated negatively with the years of diving experience. This association was independent of age, height, and pack-years of cigarette smoking. For the majority of the divers and referents the expiratory HRCT revealed minor lobular air trapping without any difference between the groups. The HRCT did not show relevant morphologic abnormalities of small or large airways. CONCLUSIONS: The data confirm that diving may affect pulmonary function. However, there is no radiologic evidence for the development of small airway disease in these 2 subgroups of divers.


Subject(s)
Diving/adverse effects , Lung/physiopathology , Respiratory Function Tests , Respiratory Mechanics/physiology , Tomography, X-Ray Computed , Adult , Germany/epidemiology , Humans , Lung Diseases, Obstructive/epidemiology , Lung Diseases, Obstructive/physiopathology , Middle Aged , Multivariate Analysis , Occupational Diseases/epidemiology , Occupational Diseases/physiopathology , Regression Analysis
13.
J Comput Assist Tomogr ; 23(1): 7-12, 1999.
Article in English | MEDLINE | ID: mdl-10050798

ABSTRACT

PURPOSE: The goal of this work was to test the ability of a combination of 2D phase-contrast MR angiography (2D-PC-MRA) and triggered 2D time-of-flight MRA (2D-TOF-MRA) in comparison to intraarterial digital subtraction angiography (DSA) to correctly diagnose the location and shape of occlusive lesions in the iliac and femoral arteries and to determine whether 2D-TOF-MRA is helpful to clarify questionable lesions demonstrated by 2D-PC-MRA. METHODS: In 50 patients with claudication, 2D-PC-MRA was performed in three consecutive coronal positions from the aortic bifurcation to below the trifurcation. Axial 2D-TOF-MRA was performed additionally at the site of detected lesions of >50% and lesions in doubt to obtain more precise information about the stenosis. Lesions were classified as follows: low grade occlusion, <50%; high grade occlusion, >50%. MRA was performed within 24 h of a DSA examination. RESULTS: In all patients, the arterial tree from the aortic bifurcation to the trifurcation could be visualized. One hundred twelve lesions were detected by MRA. Sensitivity was 96% and specificity was 92%. Sixty-two lesions were classified as high grade occlusion and reevaluated. In this category, sensitivity was 100% and specificity was 96%. CONCLUSION: The combination of 2D-PC-MRA with triggered 2D-TOF-MRA detects stenotic lesions in the lower extremity arterial system with high sensitivity and specificity.


Subject(s)
Arterial Occlusive Diseases/diagnosis , Leg/blood supply , Magnetic Resonance Angiography , Adult , Aged , Aged, 80 and over , Angiography, Digital Subtraction , Arterial Occlusive Diseases/diagnostic imaging , Female , Femoral Artery/diagnostic imaging , Femoral Artery/pathology , Humans , Iliac Artery/diagnostic imaging , Iliac Artery/pathology , Intermittent Claudication/diagnosis , Intermittent Claudication/diagnostic imaging , Magnetic Resonance Angiography/methods , Male , Middle Aged , Sensitivity and Specificity
14.
Neurol Res ; 20(8): 705-8, 1998 Dec.
Article in English | MEDLINE | ID: mdl-9864734

ABSTRACT

The utility of magnetic resonance angiography is sometimes limited in the diagnostic workup of cerebral aneurysms with low flow and/or partial thrombosis when weighed against digital subtraction angiography. We present the case of a rare superior cerebellar artery giant, partially thrombosed aneurysm in which additional i.v. contrast-enhanced MRA sequences were comparable to digital subtraction angiography. It demonstrated not only the exact spatial resolution and correct anatomical relation but also the hemodynamics which were confirmed by intraoperative Doppler ultrasound. This report supports the feasibility and utility of i.v. contrast-enhanced MRA for posterior fossa giant cerebral aneurysm management.


Subject(s)
Cerebral Angiography/methods , Cranial Fossa, Posterior , Intracranial Aneurysm/diagnosis , Magnetic Resonance Angiography/methods , Cerebellum/blood supply , Cerebrovascular Circulation , Humans , Male , Middle Aged , Pons/blood supply
15.
AJR Am J Roentgenol ; 171(6): 1627-30, 1998 Dec.
Article in English | MEDLINE | ID: mdl-9843301

ABSTRACT

OBJECTIVE: The purpose of this study was to use intravascular sonography to evaluate neointima formation, plaque location, and the performance of self-expanding nitinol (Memotherm) stents in iliac arteries. SUBJECTS AND METHODS: Seventeen patients (mean age, 64+/-9.4 years) with stenoses or occlusions of the common (n = 12) or external (n = 5) iliac artery were treated with 21 Memotherm stents (mean diameter +/- SD, 8.9+/-1.3 mm; mean length, 53+/-20.9 mm). Four patients had two stents each. Intravascular sonography was performed 13+/-6 months after stent implantation. Maximum thickness of neointima and maximum cross-sectional plaque area were measured. Qualitative analysis of plaque composition and lesion topography were also assessed. RESULTS: Intravascular sonography revealed 22.1%+/-17.3% maximum percentage of restenosis, and maximum plaque area was found to be 11.2+/-10 mm2. Only hypoechogenic in-stent lesions (soft plaques) were found. Seven (33%) incomplete stent expansions and two (10%) incomplete appositions of the stent to the vessel wall were revealed by intravascular sonography. CONCLUSION: Iliac artery Memotherm stents generally showed moderate in-stent restenosis with uniform neointima distribution. Incomplete stent expansion was detected in one third of all implanted stents.


Subject(s)
Alloys , Arterial Occlusive Diseases/therapy , Iliac Artery , Stents , Ultrasonography, Interventional , Arterial Occlusive Diseases/diagnostic imaging , Arterial Occlusive Diseases/pathology , Female , Humans , Iliac Artery/diagnostic imaging , Iliac Artery/pathology , Male , Middle Aged , Observer Variation , Recurrence , Tunica Intima/diagnostic imaging , Tunica Intima/pathology
16.
J Biol Chem ; 273(42): 27064-9, 1998 Oct 16.
Article in English | MEDLINE | ID: mdl-9765221

ABSTRACT

Polyphenol oxidases (PPOs) are nuclear-encoded chloroplast proteins that are targeted to the thylakoid lumen by a bipartite presequence. The N-terminal part of this sequence is removed by a stromal processing peptidase (SPP), and the resulting intermediate is translocated across the thylakoid and processed to the mature protein. A 4800-fold-purified SPP processed a PPO precursor (pPPO) at a site identical to that occurring in organelle. The in vitro product of SPP action on pPPO was further processed and translocated by thylakoids. This SPP processed other precursors but was inactive toward those of light-harvesting chlorophyll binding proteins. The enzyme appeared to be a metalloendopeptidase, like previously reported SPPs. However, it differed in substrate specificity, apparent size, and, most significantly, cleavage site of pPPO. Whereas the processing sites of lumen proteins determined so far were relatively distant from the hydrophobic core of the thylakoid targeting domain, pPPO was cleaved immediately before this domain. Cleavage removed the twin arginine motif characteristic of thylakoid targeting domains of lumen proteins, which are translocated by the DeltapH-dependent pathway. The possible significance of these observations to PPO translocation mechanism is discussed. It is suggested that several SPPs may exist in chloroplasts with preferences for different subsets of precursors.


Subject(s)
Catechol Oxidase/metabolism , Chloroplasts/enzymology , Metalloendopeptidases/isolation & purification , Plant Proteins , Protein Processing, Post-Translational , Amino Acid Sequence , Biological Transport , Cell Compartmentation , Solanum lycopersicum , Metalloendopeptidases/genetics , Metalloendopeptidases/metabolism , Molecular Sequence Data , Pisum sativum , Protein Precursors/metabolism , Sequence Analysis , Substrate Specificity
18.
Rofo ; 168(6): 604-9, 1998 Jun.
Article in German | MEDLINE | ID: mdl-9687953

ABSTRACT

PURPOSE: To evaluate effectiveness, success and patency rates after endovascular treatment with mid-size Palmaz stents in high-grade stenoses or short-distance occlusions of femoral arteries. MATERIALS AND METHODS: 27 patients with 10 occlusions (average length 3.2 +/- 1.4 cm) and 17 severe stenoses of the superficial femoral artery were treated with 33 mid-size Palmaz stents. The follow-up included Doppler ultrasound at one, three, 6 and 12 months and an angiography at 6 months. Mean follow-up was 6.5 months. RESULTS: Technical success was 100%. The ankle-brachial index improved from 0.57 +/- 0.28 pretreatment to 0.87 +/- 0.13 within 24 hours. Acute stent thrombosis occurred in two patients (< 3 weeks). Angiography at 6 months revealed restenosis rates of 7.4% (> 50%, n = 2). Life-table analysis according to Kaplan-Meier revealed 6-month primary and secondary patency rates of 84% and 91%. CONCLUSION: With regard to our limited data, the implantation of mid-size Palmaz stents in femoral arteries seems promising in treatment of short-distance occlusions and stenoses of the femoral artery.


Subject(s)
Angioplasty, Balloon , Arterial Occlusive Diseases/surgery , Femoral Artery , Leg/blood supply , Popliteal Artery , Stents , Aged , Aged, 80 and over , Angiography, Digital Subtraction , Arterial Occlusive Diseases/diagnostic imaging , Data Interpretation, Statistical , Female , Follow-Up Studies , Humans , Male , Middle Aged , Recurrence , Time Factors
19.
Rofo ; 169(1): 22-6, 1998 Jul.
Article in German | MEDLINE | ID: mdl-9711278

ABSTRACT

PURPOSE: To determine the usefulness of contrast-enhanced MR angiography for the diagnosis of Leriche's syndrome. MATERIAL AND METHODS: Leriche's syndrome was seen in 7 patients via DSA. In addition, contrast-enhanced MR angiography was performed (TR 7.8 ms/TE 2.1 ms, flip angle 30 degrees, slab thickness 116 mm, slice thickness 1.82 mm, 64 partitions, FOV 500 x 438 mm, matrix 224 x 512). RESULTS: Diagnosis of Leriche's syndrome was possible by contrast-enhanced MR angiography in each case. Visualisation of the femoral arteries was not possible in two patients by intraarterial DSA, in three other patients there was an insufficient contrast in the femoral arteries with DSA. Contrast-enhanced MR angiography revealed good visualisation of the femoral arteries in these patients. In addition, contrast-enhanced MR angiography allowed complete visualisation of the patent lower limb arteries. In intraarterial DSA visualisation of the lower limb arteries was achieved reached in only one patient, but was incomplete. CONCLUSION: Contrast-enhanced MR angiography yielded the correct diagnosis of Leriche's syndrome in all 7 patients. Contrast-enhanced MR angiography was superior to DSA in the assessment of the distal run-off vessels in five of seven patients.


Subject(s)
Contrast Media , Gadolinium DTPA , Leriche Syndrome/diagnosis , Magnetic Resonance Angiography/methods , Adult , Aged , Angiography, Digital Subtraction , Evaluation Studies as Topic , Female , Humans , Male , Middle Aged
20.
Rofo ; 168(4): 330-6, 1998 Apr.
Article in German | MEDLINE | ID: mdl-9589094

ABSTRACT

PURPOSE: A comparison of ultra rapid T2-weighted HASTE and HASTE-STIR sequences during suspended respiration for the detection of focal lesions of the liver. MATERIAL AND METHODS: Twenty-one patients (59 +/- 12 years) with a total of 33 focal lesions (7 < or = 1 cm, 19 < or = 3 cm; 17 cystic liquid and 16 solid lesions) were examined with a 1.5 T MR apparatus. Sequences: T2 weighted HASTE (TEeff = 64 ms, 90 ms), HASTE-STIR (TEeff = 64 ms, 81 ms) TSE (TE = 132 ms) and T1-weighted FLASH 2D. RESULTS: The T2-weighted TSE and both HASTE sequences showed all the lesions. Two out of the 33 lesions were not demonstrated by the other sequences. Best image quality without movement artefacts and the best resolution of the lesions in the T2-weighted sequences, with the most favourable contrast/noise ratio (36.6 +/- 33.1) and signal/noise ratio (20.8 +/- 10.5) resulted from the HASTE 90, followed by the HASTE 64 sequence (27.5 +/- 24.2; 24.6 +/- 9.1). Both these techniques were superior to the TSE sequence (23.9 +/- 29.4; 13.9 +/- 7.4), which resulted in movement artifacts. With the HASTE-STIR sequences it was possible to show 31 and 32 of the 33 lesions respectively, with very good resolution but poor signal/noise ratio. CONCLUSION: HASTE sequences have the potential of improving the diagnosis of focal liver lesions.


Subject(s)
Cysts/diagnosis , Liver Diseases/diagnosis , Liver Neoplasms/diagnosis , Liver/pathology , Magnetic Resonance Imaging/methods , Adenoma/diagnosis , Adult , Aged , Artifacts , Cysts/diagnostic imaging , Cysts/pathology , Female , Hemangioma/diagnosis , Hematoma/diagnosis , Humans , Hyperplasia , Liver/diagnostic imaging , Liver Diseases/diagnostic imaging , Liver Diseases/pathology , Liver Neoplasms/diagnostic imaging , Liver Neoplasms/pathology , Liver Neoplasms/secondary , Male , Middle Aged , Tomography, X-Ray Computed
SELECTION OF CITATIONS
SEARCH DETAIL
...