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21.
Whole-heart cine MRI using real-time respiratory self-gating. 总被引:1,自引:0,他引:1
Sergio Uribe Vivek Muthurangu Redha Boubertakh Tobias Schaeffter Reza Razavi Derek L G Hill Michael S Hansen 《Magnetic resonance in medicine》2007,57(3):606-613
Two-dimensional (2D) breath-hold cine MRI is used to assess cardiac anatomy and function. However, this technique requires cooperation from the patient, and in some cases the scan planning is complicated. Isotropic nonangulated three-dimensional (3D) cardiac MR can overcome some of these problems because it requires minimal planning and can be reformatted in any plane. However, current methods, even those that use undersampling techniques, involve breath-holding for periods that are too long for many patients. Free-breathing respiratory gating sequences represent a possible solution for realizing 3D cine imaging. A real-time respiratory self-gating technique for whole-heart cine MRI is presented. The technique enables assessment of cardiac anatomy and function with minimum planning or patient cooperation. Nonangulated isotropic 3D data were acquired from five healthy volunteers and then reformatted into 2D clinical views. The respiratory self-gating technique is shown to improve image quality in free-breathing scanning. In addition, ventricular volumetric data obtained using the 3D approach were comparable to those acquired with the conventional multislice 2D approach. 相似文献
22.
Richard Werner Karsten Alfke Tobias Schaeffter Arya Nabavi H Maximilian Mehdorn Olav Jansen 《Magnetic resonance in medicine》2004,52(6):1443-1447
A new method for the selective spin labeling of left- or right-sided supplying arteries of the brain without the need for additional RF coils is demonstrated. A clinical 1.5 T scanner was used. The spatial selectivity of the labeling process is based on the limited coverage of the excitation field of a standard send/receive head coil together with an oblique positioning of the labeling plane. A computer simulation was used to optimize key labeling parameters under the condition of laminar flow. The validity of the computer model results was confirmed by MRI measurements with a flow model. For human studies, a double-inversion continuous arterial spin labeling (CASL) sequence was modified to allow for arbitrary positioning of the labeling plane. The obtained perfusion-weighted images showed a clear delineation of the perfusion territories of the selected arteries in the anterior circulation of the brain and good gray/white matter contrast. 相似文献
23.
L. Simonato J. J. Moulin B. Javelaud G. Ferro P. Wild R. Winkelmann R. Saracci 《American journal of industrial medicine》1994,25(5):625-633
A historical mortality study of a cohort of employees of a gold mining and refining company was carried out in Salsigne, France. A major goal of the study was to investigate the relationship between lung cancer mortality and exposure to arsenic, radon, silica, and other contaminants of the working environment. A twofold excess of lung cancer was found both among miners and smelters, mainly concentrated among workers who had experienced exposure to past levels of arsenic, radon, and silica. The consistency of the results in the mine and the refinery are suggestive of a carcinogenic risk from both soluble and insoluble arsenic, although the potential role of other factors cannot be dismissed. © 1994 Wiley-Liss, Inc. 相似文献
24.
S. Dietze D. Winkelmann R. Garve T. Blens J. Fanghnel P. Proff T. Gedrange S. Maile 《Annals of anatomy》2007,189(3):304-308
Numerous ritual acts involving the skull result in orofacial changes. The present study focuses on ritual acts of Brazilian Zoé Indians. A distinct deformation effect of the ritual act (wearing a lip-plug) on the morphology of the orofacial system is demonstrated and documented using jaw models. The studies show that the lip-plug significantly influences tooth position and jaw growth. While the maxilla displays palatal displacement of the lateral incisors and elevation of the palate, retraction occurs in the mandible depending upon plug size. Additionally, both the plug and the nutritional habits of the Indians induce marked abrasion of all teeth. Moreover, it is shown that the duration of lip-plug wear is an essential determinant of sustained orofacial changes. 相似文献
25.
Wolfgang H Oertel Tobias W?chter Niall P Quinn Gudrun Ulm Dirk Brandst?dter 《Movement disorders》2003,18(4):430-432
According to the consensus statement on the diagnosis of multiple system atrophy (MSA), erectile dysfunction is required for male patients to fulfil the urinary incontinence criterion. However, there is no equivalent item for female patients. We questioned 19 female patients with MSA of the parkinsonian type (MSA-P), 28 female patients with Parkinson's disease (PD), and 27 healthy controls on their genital sensitivity. A total of 47% of the MSA patients but only 4% of the PD patients and 4% of the control group admitted to reduced genital sensitivity, a highly significant difference (P < 0.001). Moreover, the appearance of reduced genital sensitivity in female MSA patients showed a close temporal relation to the onset of the disease. If these preliminary results can be confirmed and further specified in a larger sample, a historical item of reduced genital sensitivity in female patients might become a diagnostic feature for MSA, comparable to erectile dysfunction in male patients. 相似文献
26.
Three-dimensional reconstruction of magnetic resonance images of the temporomandibular joint by I-DEAS. 总被引:1,自引:0,他引:1
Evaluation of the temporomandibular joint has been limited by the inability of current technology to image complex morphology and motion in three dimensions. An engineering design program, I-DEAS, has been used to construct solid models from magnetic resonance images. A dried skull with an acrylic resin temporomandibular disc replica, immersed in water, provided sagittal and coronal MR images. Linear dimensions and disc volumes obtained from the models were compared with the original and found to be consistent, within the limits imposed by the slice thickness. We have applied the method to the living joint in an asymptomatic volunteer, and report our initial experience in demonstrating the spatial relationships and motion of the joint components. 相似文献
27.
Jan Stulik Tobias Rainer Pitzen Jan Chrobok Sabine Ruffing Jörg Drumm Laurentius Sova Ravel Kucera Tomas Vyskocil Wolf Ingo Steudel 《European spine journal》2007,16(10):1689-1694
Anterior cervical plate fixation is an approved surgical technique for cervical spine stabilization in the presence of anterior
cervical instability. Rigid plate design with screws rigidly locked to the plate is widely used and is thought to provide
a better fixation for the treated spinal segment than a dynamic design in which the screws may slide when the graft is settling.
Recent biomechanical studies showed that dynamic anterior plates provide a better graft loading possibly leading to accelerated
spinal fusion with a lower incidence of implant complications. This, however, was investigated in vitro and does not necessarily
mean to be the case in vivo, as well. Thus, the two major aspects of this study were to compare the speed of bone fusion and
the rate of implant complications using either rigid- or dynamic plates. The study design is prospective, randomized, controlled,
and multi-centric, having been approved by respective ethic committees of all participating sites. One hundred and thirty-two
patients were included in this study and randomly assigned to one of the two groups, both undergoing routine level-1- or level-2
anterior cervical discectomy with autograft fusion receiving either a dynamic plate with screws being locked in ap - position
(ABC, Aesculap, Germany), or a rigid plate (CSLP, Synthes, Switzerland). Segmental mobility and implant complications were
compared after 3- and 6 months, respectively. All measurements were performed by an independent radiologist. Mobility results
after 6 months were available for 77 patients (43 ABC/34 CSLP). Mean segmental mobility for the ABC group was 1.7 mm at the
time of discharge, 1.4 mm after 3 months, and 0.8 mm after 6 months. For the CSLP- group the measurements were 1.0, 1.8, and
1.7 mm, respectively. The differences of mean segmental mobility were statistically significant between both groups after
6 months (P = 0.02). Four patients of the CSLP-group demonstrated surgical hardware complications, whereas no implant complications were
observed within the ABC-group (P = 0.0375). Dynamic plate designs provided a faster fusion of the cervical spine compared with rigid plate designs after prior
spinal surgery. Moreover, the rate of implant complications was lower within the group of patients receiving a dynamic plate.
These interim results refer to a follow-up period of 6 months after prior spinal surgery. Further investigations will be performed
2 years postoperatively. 相似文献
28.
Physicians may have the opportunity to prevent suicide. An awareness of suicide risk factors, such as depression, alcoholism, drug abuse, schizophrenia, and chronic pain or disease, may facilitate suicide prevention. Recognition of acute and chronic suicidal vulnerability occurs through direct questioning. Psychiatric consultation is indicated for patients exhibiting clear self-injury risk, as exemplified by expressed suicide intent, an overt plan for death, or a "gesture." Hospitalization is usually recommended for socially isolated patients presenting with overt suicidal ideation, complicated by injurious self-harm, encephalopathy, or substance abuse. Family involvement and a "no-suicide" contract with the patient, coupled with close outpatient follow-up appointments, should suffice for those exhibiting milder or transient thoughts of suicide without manifest intent to die. 相似文献
29.
Functional analysis of the cag pathogenicity island in Helicobacter pylori isolates from patients with gastritis, peptic ulcer, and gastric cancer 总被引:9,自引:0,他引:9
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Backert S Schwarz T Miehlke S Kirsch C Sommer C Kwok T Gerhard M Goebel UB Lehn N Koenig W Meyer TF 《Infection and immunity》2004,72(2):1043-1056
Helicobacter pylori is the causative agent of a variety of gastric diseases, but the clinical relevance of bacterial virulence factors is still controversial. Virulent strains carrying the cag pathogenicity island (cagPAI) are thought to be key players in disease development. Here, we have compared cagPAI-dependent in vitro responses in H. pylori isolates obtained from 75 patients with gastritis, peptic ulcer, and gastric cancer (n = 25 in each group). AGS gastric epithelial cells were infected with each strain and assayed for (i) CagA expression, (ii) translocation and tyrosine phosphorylation of CagA, (iii) c-Src inactivation, (iv) cortactin dephosphorylation, (v) induction of actin cytoskeletal rearrangements associated with cell elongation, (vi) induction of cellular motility, and (vii) secretion of interleukin-8. Interestingly, we found high but similar prevalences of all of these cagPAI-dependent host cell responses (ranging from 56 to 80%) among the various groups of patients. This study revealed CagA proteins with unique features, CagA subspecies of various sizes, and new functional properties for the phenotypic outcomes. We further showed that induction of AGS cell motility and elongation are two independent processes. Our data corroborate epidemiological studies, which indicate a significant association of cagPAI presence and functionality with histopathological findings in gastritis, peptic ulcer, and gastric cancer patients, thus emphasizing the importance of the cagPAI for the pathogenicity of H. pylori. Nevertheless, we found no significant association of the specific H. pylori-induced responses with any particular patient group. This may indicate that the determination of disease development is highly complex and involves multiple bacterial and/or host factors. 相似文献
30.
Molecular basis of the functional podocin-nephrin complex: mutations in the NPHS2 gene disrupt nephrin targeting to lipid raft microdomains 总被引:10,自引:0,他引:10
Huber TB Simons M Hartleben B Sernetz L Schmidts M Gundlach E Saleem MA Walz G Benzing T 《Human molecular genetics》2003,12(24):3397-3405
Hereditary nephrotic syndrome is a heterogeneous disease, characterizedby heavy proteinuria and renal failure. Mutations of NPHS1 orNPHS2, the genes encoding for nephrin and podocin, lead to earlyonset of heavy proteinuria, and rapid progression to end-stagerenal disease, suggesting that both proteins are essential forthe integrity of the glomerular filter. Podocin is a stomatinprotein family member with a predicted hairpin-like structurelocalizing to the insertion site of the slit diaphragm of podocytes,the visceral glomerular epithelial cells of the kidney. Herewe investigate the pathomechanisms of different disease-causingpodocin mutations. We show that wild-type podocin is targetedto the plasma membrane, and forms homo-oligomers involving thecarboxy and amino terminal cytoplasmic domains. The associationof podocin with specialized lipid raft microdomains of the plasmamembrane was a prerequisite for recruitment of nephrin intorafts. In contrast, disease-causing mutations of podocin (R138Qand R138X) failed to recruit nephrin into rafts either becausethese mutants were retained in the endoplasmic reticulum (R138Q),or because they failed to associate with rafts (R138X) despitetheir presence in the plasma membrane. None of the mutants didaugment nephrin signaling, suggesting that lipid raft targetingfacilitates nephrin signaling. Our findings demonstrate thatthe failure of mutant podocin to recruit nephrin into lipidrafts may be essential for the pathogenesis of NPHS2.
* To whom correspondence should be addressed. Tel: +49 7612703559;Fax: +49 7612706362; Email: benzing{at}med1.ukl.uni-freiburg.de
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