886 resultados para Crack pattern
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BACKGROUND: Diabetes mellitus (DM) and renal insufficiency (RI) were shown to be associated with an obstructive lesion pattern favouring distal lower limb arterial segments in patients with peripheral arterial disease (PAD). We hypothesized that presence of DM is associated with pronounced involvement of the tibioperoneal arteries, whereas RI predominantly affects the pedal arch. PATIENTS AND METHODS: A consecutive series of PAD patients (mean age 75 +/- 10 years, 40 women) with RI alone (n = 15), RI and DM (n = 25), DM alone (n = 25) and without RI or DM (n = 25) underwent diagnostic angiography. We analyzed the obstructive burden of different segments of the infrageniculate arterial tree using the Bollinger score as well as accessibility of pedal arteries for bypass surgery. RESULTS: In patients with DM and in patients with RI the mean total obstructive burden was higher in pedal as compared to tibioperoneal arteries (9.79 +/- 4.60 vs. 6.99 +/- 3.45, p = 0.03;10.50 +/- 5.53 vs. 6.88 +/- 4.12, p = 0.05, respectively). However, rates of patency of at least one pedal artery were significantly lower in patients with RI and RI/DM as compared to controls (47% and 48% vs. 80%, respectively; p = 0.007), whereas patency was comparable between patients with diabetes alone and controls (72% vs. 80%, ns). Rates of viability of pedal arteries as an attachment site for distal bypass was 80%, 68%, 47% and 44% in controls, patients with DM alone, RI alone and RI/DM, respectively (p = 0.0042). CONCLUSIONS: In contrast to previous anecdotal observations, both DM and RI are associated with a high atherosclerotic burden of the pedal arch in the present angiographic series. The presence of RI, however, is associated with a lower patency of the pedal arch as compared to the presence of DM alone, and more than fifty percent patients are unsuitable for distal bypass grafting.
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BACKGROUND: Transient apical ballooning syndrome (TABS) or Takotsubo cardiomyopathy mimics acute ST-elevation myocardial infarction, but is considered to have a good prognosis with only moderate elevation of myocardial enzymes and full recovery of left ventricular function. Although it is increasingly reported, its exact incidence, clinical presentation, and prognosis in non-Asian populations remain largely unknown. OBJECTIVE: To describe the clinical characteristics and long-term follow-up of patients who presented with TABS at our institution over a 3 year-period. METHODS: Patients were retrospectively retrieved from our local database. Patient charts were carefully reviewed and the diagnosis of TABS was based on the Mayo Clinic diagnostic criteria. Moreover, psychosocial stress or gastrointestinal disease was recorded. RESULTS: During the study period, 13,715 coronary angiographies were performed at our institution, including 2459 patients presenting with an acute coronary syndrome (ACS). Forty-one TABS were diagnosed, which represents an incidence of 1.7% of ACS-patients and 0.3% of all coronary angiographies performed, respectively. Mean age was 65 years, with 85% women. Clinical presentations included chest pain, dyspnoea, and cardiogenic shock. A preceding psychological or physical condition perceived as "stress" was reported in 61%. At a mean follow-up of 675+/-288 days, none of the patients died of cardiac causes, but two patients had a recurrence of symptoms. CONCLUSIONS: This is the largest cohort of TABS patients reported out of Europe so far. The good overall prognosis and low likelihood of recurrence were confirmed.
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BACKGROUND: Morphological changes in preterm infants with bronchopulmonary dysplasia (BPD) have functional consequences on lung volume, ventilation inhomogeneity and respiratory mechanics. Although some studies have shown lower lung volumes and increased ventilation inhomogeneity in BPD infants, conflicting results exist possibly due to differences in sedation and measurement techniques. METHODOLOGY/PRINCIPAL FINDINGS: We studied 127 infants with BPD, 58 preterm infants without BPD and 239 healthy term-born infants, at a matched post-conceptional age of 44 weeks during quiet natural sleep according to ATS/ERS standards. Lung function parameters measured were functional residual capacity (FRC) and ventilation inhomogeneity by multiple breath washout as well as tidal breathing parameters. Preterm infants with BPD had only marginally lower FRC (21.4 mL/kg) than preterm infants without BPD (23.4 mL/kg) and term-born infants (22.6 mL/kg), though there was no trend with disease severity. They also showed higher respiratory rates and lower ratios of time to peak expiratory flow and expiratory time (t(PTEF)/t(E)) than healthy preterm and term controls. These changes were related to disease severity. No differences were found for ventilation inhomogeneity. CONCLUSIONS: Our results suggest that preterm infants with BPD have a high capacity to maintain functional lung volume during natural sleep. The alterations in breathing pattern with disease severity may reflect presence of adaptive mechanisms to cope with the disease process.
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Three closely related human sec14p-like proteins (hTAP1, 2, and 3, or SEC14L2, 3, and 4, respectively) have been described. These proteins may participate in intracellular lipid transport (phospholipids, squalene, tocopherol analogues and derivatives) or influence regulatory lipid-dependent events. Here, we show that the three recombinant hTAP proteins associate with the Golgi apparatus and mitochondria, and enhance the in vitro transport of radioactively labeled alpha-tocopherol to mitochondria in the same order of magnitude as the human alpha-tocopherol transfer protein (alpha-TTP). hTAP1 and hTAP2 are expressed in several cell lines, whereas the expression level of hTAP3 is low. Expression of hTAP1 is induced in human umbilical cord blood-derived mast cells upon differentiation by interleukin 4. In tissues, the three hTAPs are detectable ubiquitously at low level; pronounced and localized expression is found for hTAP2 and hTAP3 in the perinuclear region in cerebellum, lung, liver and adrenal gland. hTAP3 is well expressed in the epithelial duct cells of several glands, in ovary in endothelial cells of small arteries as well as in granulosa and thecal cells, and in testis in Leydig cells. Thus, the three hTAPs may mediate lipid uptake, secretion, presentation, and sub-cellular localization in a tissue-specific manner, possibly using organelle- and enzyme-specific docking sites.
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Fuel-lean combustion and exhaust gas recirculation (EGR) in spark ignition engines improve engine efficiency and reduce emission. However, flame initiation becomes more difficult in lean and dilute fuel-air mixture with traditional spark discharge. This research proposal will first provide an intensive review on topics related to spark ignition including properties of electrical discharge, flame kernel behavior and spark ignition modeling and simulation. Focus will be laid on electrical discharge pattern effect as it is showing prospect in extending ignition limits in SI engines. An experimental setup has been built with an optically accessible constant volume combustion vessel. Multiple imaging techniques as well as spectroscopy will be applied. By varying spark discharge patterns, preliminary test results are available on consequent flame kernel development. In addition to experimental investigation of spark plasma and flame kernel development, spark ignition modeling with detailed description of plasma channel is also proposed for this study.
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The B-box motif is the defining feature of the TRIM family of proteins, characterized by a RING finger-B-box-coiled coil tripartite fold. We have elucidated the crystal structure of B-box 2 (B2) from MuRF1, a TRIM protein that supports a wide variety of protein interactions in the sarcomere and regulates the trophic state of striated muscle tissue. MuRF1 B2 coordinates two zinc ions through a cross-brace alpha/beta-topology typical of members of the RING finger superfamily. However, it self-associates into dimers with high affinity. The dimerization pattern is mediated by the helical component of this fold and is unique among RING-like folds. This B2 reveals a long shallow groove that encircles the C-terminal metal binding site ZnII and appears as the defining protein-protein interaction feature of this domain. A cluster of conserved hydrophobic residues in this groove and, in particular, a highly conserved aromatic residue (Y133 in MuRF1 B2) is likely to be central to this role. We expect these findings to aid the future exploration of the cellular function and therapeutic potential of MuRF1.
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Liver fibrosis is characterized by high expression of the key profibrogenic cytokine transforming growth factor (TGF)-beta and the natural tissue inhibitor of metalloproteinases (TIMP)-1, leading to substantial accumulation of extracellular matrix. Liver fibrosis originates from various chronic liver diseases, such as chronic viral hepatitis that, to date, cannot be treated sufficiently. Thus, novel therapeutics, for example, those derived from Oriental medicine, have gained growing attention. In Korea, extracts prepared from Lindera obtusiloba are used for centuries for treatment of inflammation, improvement of blood circulation and prevention of liver damage, but experimental evidence of their efficacy is lacking. We studied direct antifibrotic effects in activated hepatic stellate cells (HSCs), the main target cell in the fibrotic liver. L. obtusiloba extract (135 mug/ml) reduced the de novo DNA synthesis of activated rat and human HSCs by about 90%, which was not accompanied by cytotoxicity of HSC, primary hepatocytes and HepG2 cells, pointing to induction of cellular quiescence. As determined by quantitative polymerase chain reaction, simultaneous treatment of HSCs with TGF-beta and L. obtusiloba extract resulted in reduction of TIMP-1 expression to baseline level, disruption of the autocrine loop of TGF-beta autoinduction and increased expression of fibrolytic matrix metalloproteinase (MMP)-3. In addition, L. obtusiloba reduced gelatinolytic activity of HSC by interfering with profibrogenic MMP-2 activity. Since L. obtusiloba extract prevented intracellular oxidative stress experimentally induced by tert-butylhydroperoxide, we concluded that the direct antifibrotic effect of L. obtusiloba extract might be mediated by antioxidant activity. Thus, L. obtusiloba, traditionally used in Oriental medicine, may complement treatment of chronic liver disease.
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Cognitive-motivational theories of phobias propose that patients' behavior is characterized by a hypervigilance-avoidance pattern. This implies that phobics initially direct their attention towards fear-relevant stimuli, followed by avoidance that is thought to prevent objective evaluation and habituation. However, previous experiments with highly anxious individuals confirmed initial hypervigilance and yet failed to show subsequent avoidance. In the present study, we administered a visual task in spider phobics and controls, requiring participants to search for spiders. Analyzing eye movements during visual exploration allowed the examination of spatial as well as temporal aspects of phobic behavior. Confirming the hypervigilance-avoidance hypothesis as a whole, our results showed that, relative to controls, phobics detected spiders faster, fixated closer to spiders during the initial search phase and fixated further from spiders subsequently.
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Patients with chronic pain disorders often show somatosensory disturbances that are considered to be functional. This paper aims at a more precise clinical description and at a documentation of functional neuroimaging correlates of this phenomenon. We examined 30 consecutive patients with unilaterally accentuated chronic pain not explained by persistent peripheral tissue damage and ipsilateral somatosensory disturbances including upper and lower extremities and trunk. The patients were assessed clinically and with conventional brain CT or MRI scan. In the last 11 patients functional neuroimaging was carried out (18-fluordeoxyglucose positron emission tomography=FDG-PET). Depressive symptoms were assessed with the Hamilton depression scale (HAMD-17) and pain intensity was rated with a visual analogue scale for pain (VAS). All patients suffered from mild to moderate depressive symptoms. All patients had experienced a prolonged antecedent phase of severe emotional distress; most of them remembered a "trigger episode of somatic pain" on the affected side. Somatosensory deficits were a replicable hyposensitivity to touch and heat perception of nondermatomal distribution. Conventional imaging procedures (brain CT or MRI scans) showed no structural changes. However, in 11 patients functional imaging with FDG-PET showed a significant hypometabolic pattern of changes in cortical and subcortical areas, mainly in the post-central gyrus, posterior insula, putamen, and anterior cingulate cortex. In summary, pain-related nondermatomal somatosensory deficits (NDSDs) are a phenomenon involving biological as well as psychosocial factors with replicable neuroperceptive clinical findings and a complex neurodysfunctional pattern in the FDG-PET.
Activity pattern dependent LTP in neocortex and hippocampus of GluA1 (GluR-A) subunit deficient mice
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OBJECTIVE: Glycodelin (PP14) is produced by the epithelium of the endometrium and its determination in the serum is used for functional evaluation of this tissue. Given the complex regulation and the combined contraceptive and immunosuppressive roles of glycodelin, the current lack of normal values for its serum concentration in the physiological menstrual cycle, derived from a large sample number, is a problem. We have therefore established reference values from over 600 sera. DESIGN: Retrospective study using banked serum samples. SETTING: University hospital. METHODS: Measurement of blood samples daily or every second day during one full cycle. MAIN OUTCOME MEASURES: Serum concentrations of glycodelin and normal values for every such one- or two-day interval were calculated. Late luteal phase glycodelin levels were compared with ovarian hormones. Follicular phase levels were compared with stimulated cycles from patients undergoing in vitro fertilization. RESULTS: Glycodelin concentrations were low around ovulation. Highest levels were observed at the end of the luteal phase; the glycodelin serum peak was reached 6-8 days after the one for progesterone. Late luteal glycodelin levels correlated negatively with the body mass index and positively with the progesterone level earlier in the secretory (mid-luteal) phase in the same woman. No associations with other ovarian hormones were observed. Follicular phase glycodelin levels were higher in the spontaneous than in the in vitro fertilization cycles. CONCLUSIONS: Normal values taken at two- or one-day intervals demonstrate the very late appearance of high serum glycodelin levels during the physiological menstrual cycle and their correlation with progesterone occurring earlier in the cycle.