987 resultados para phase contrast


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Background: The prevalence of small intestinal bowel bacterial overgrowth (SIBO) in patients with irritable bowel syndrome (IBS) ranges from 43% to 78% as determined by the lactulose hydrogen breath (LHBT) test. Although rifaximine, a non-absorbable antibiotic, has been able to decrease global IBS symptoms as well as bloating in placebo-controlled randomized trials, these results were not repeated in phase IV studies in daily clinical practice. Aim: To assess the prevalence of SIBO in an IBS cohort and to evaluate the treatment response in the IBS cohort affected by SIBO. Methods: Enrolled patients were diagnosed with IBS using the following criteria: fulfillment of the Rome III criteria, absence of alarm symptoms (anemia, weight loss, nocturnal symptoms etc), normal fecal calproectin, normal endoscopic workup including histology. Celiac disease was excluded by serology and/or duodenal biopsy. All patients underwent lactulose hydrogen breath testing (LHBT) for SIBO diagnosis. Patients with SIBO were treated with rifaximine tablets (400mg twice daily for 14 days). Both before and at week 6 after rifaximin treatment, patients completed a questionnaire, where the following criteria were assessed individually using 11-point Likert scales: the bloating, flatulence, abdominal pain, diarrhea, and overall well-being. Results: Hundred-fifty IBS patients were enrolled (76% female, mean age 44 ± 16 years), of whom 106 (71%) were diagnosed with SIBO and consequently treated with rifaximine. Rifaximine treatment significantly reduced the following symptoms as assessed by the symptom questionnaire: bloating (5.5 ± 2.6 before vs. 3.6 ± 2.7 after treatment, p <0.001), flatulence (5 ± 2.7 vs. 4 ± 2.7, p = 0.015), diarrhea (2.9 ± 2.4 vs. 2 ± 2.4, p = 0.005), abdominal pain (4.8 ± 2.7 vs. 3.3 ± 2.5, p <0.001) and resulted in improved overall well-being (3.9 ± 2.4 vs. 2.7 ± 2.3, p <0.001). Thirteen of the 106 treated patients were lost to follow-up (12%). The LHBT was repeated 2-4 weeks after rifaximine treatment in 65/93 (70%) patients. Eradication of SIBO was documented in 85% of all patients (55/65), whereas 15% of patients (10/65) tested positive for SIBO as determined by the LHBT testing. Conclusions: The results of our phase IV trial indicate that a high proportion of IBS patients tested positive for SIBO. IBS symptoms (bloating, flatulence, diarrhea, pain, overall well-being) were significantly diminished following a 2-week treatment with rifaximine. These results support the previous findings of randomized controlled trials that the presence of SIBO is associated with symptom generation in IBS patients and that reduction and/or elimination of SIBO may help to alleviate IBSassociated symptoms.

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RATIONALE AND OBJECTIVES: Dose reduction may compromise patients because of a decrease of image quality. Therefore, the amount of dose savings in new dose-reduction techniques needs to be thoroughly assessed. To avoid repeated studies in one patient, chest computed tomography (CT) scans with different dose levels were performed in corpses comparing model-based iterative reconstruction (MBIR) as a tool to enhance image quality with current standard full-dose imaging. MATERIALS AND METHODS: Twenty-five human cadavers were scanned (CT HD750) after contrast medium injection at different, decreasing dose levels D0-D5 and respectively reconstructed with MBIR. The data at full-dose level, D0, have been additionally reconstructed with standard adaptive statistical iterative reconstruction (ASIR), which represented the full-dose baseline reference (FDBR). Two radiologists independently compared image quality (IQ) in 3-mm multiplanar reformations for soft-tissue evaluation of D0-D5 to FDBR (-2, diagnostically inferior; -1, inferior; 0, equal; +1, superior; and +2, diagnostically superior). For statistical analysis, the intraclass correlation coefficient (ICC) and the Wilcoxon test were used. RESULTS: Mean CT dose index values (mGy) were as follows: D0/FDBR = 10.1 ± 1.7, D1 = 6.2 ± 2.8, D2 = 5.7 ± 2.7, D3 = 3.5 ± 1.9, D4 = 1.8 ± 1.0, and D5 = 0.9 ± 0.5. Mean IQ ratings were as follows: D0 = +1.8 ± 0.2, D1 = +1.5 ± 0.3, D2 = +1.1 ± 0.3, D3 = +0.7 ± 0.5, D4 = +0.1 ± 0.5, and D5 = -1.2 ± 0.5. All values demonstrated a significant difference to baseline (P < .05), except mean IQ for D4 (P = .61). ICC was 0.91. CONCLUSIONS: Compared to ASIR, MBIR allowed for a significant dose reduction of 82% without impairment of IQ. This resulted in a calculated mean effective dose below 1 mSv.

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Extranodal NK/T-cell lymphoma, nasal type, is a rare and highly aggressive disease with a grim prognosis. No therapeutic strategy is currently identified in relapsing patients. We report the results of a French prospective phase II trial of an L-asparaginase-containing regimen in 19 patients with relapsed or refractory disease treated in 13 centers. Eleven patients were in relapse and 8 patients were refractory to their first line of treatment. L-Asparaginase-based treatment yielded objective responses in 14 of the 18 evaluable patients after 3 cycles. Eleven patients entered complete remission (61%), and only 4 of them relapsed. The median overall survival time was 1 year, with a median response duration of 12 months. The main adverse events were hepatitis, cytopenia, and allergy. The absence of antiasparaginase antibodies and the disappearance of Epstein-Barr virus serum DNA were significantly associated with a better outcome. These data confirm the excellent activity of L-asparaginase-containing regimens in extranodal NK/T-cell lymphoma. L-Asparaginase-based treatment should thus be considered for salvage therapy, especially in patients with disseminated disease. First-line L-asparaginase combination therapy for extranodal NK/T-cell lymphoma warrants evaluation in prospective trials. This trial is registered at www.clinicaltrials.gov as #NCT00283985.

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Immunodetection of human IgG anti-Toxocara canis was developed based on ELISA and on the use of polysiloxane/polyvinyl alcohol (POS/PVA) beads. A recombinant antigen was covalently immobilized, via glutaraldehyde, onto this hybrid inorganic-organic composite, which was prepared by the sol-gel technique. Using only 31.2 ng antigen per bead, a peroxidase conjugate dilution of 1:10,000 and a serum dilution of 1:200 were adequate for the establishment of the procedure. This procedure is comparable to that which utilizes the adsorption of the antigen to conventional PVC plates. However, the difference between positive and negative sera mean absorbances was larger for this new glass based assay. In addition to the performance of the POS/PVA bead as a matrix for immunodetection, its easy synthesis and low cost are additional advantages for commercial application.

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Digital holographic microscopy (DHM) is a technique that allows obtaining, from a single recorded hologram, quantitative phase image of living cell with interferometric accuracy. Specifically the optical phase shift induced by the specimen on the transmitted wave front can be regarded as a powerful endogenous contrast agent, depending on both the thickness and the refractive index of the sample. Thanks to a decoupling procedure cell thickness and intracellular refractive index can be measured separately. Consequently, Mean corpuscular volume (MCV) and mean corpuscular hemoglobin concentration (MCHC), two highly relevant clinical parameters, have been measured non-invasively at a single cell level. The DHM nanometric axial and microsecond temporal sensitivities have permitted to measure the red blood cell membrane fluctuations (CMF) on the whole cell surface. ©2009 COPYRIGHT SPIE--The International Society for Optical Engineering.

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Vaginal delivery can cause lesions of the various pelvic structures responsible for the mechanisms of continence. These lesions may perhaps be prevented in the future by measuring pressure generated during childbirth. Tear of the anal sphincter during childbirth is a marker of a global impairment of the urinary, ano-rectal and sexual pelvic functions in the short and medium term. Persistence of a defect of the anal sphincter is frequent in spite of immediate suture. The correlation between these defects and ano-rectal incontinence are not established in our experience. The quality of the contraction of the sphincter complex and pubo-rectal sling seems to play a more important role in ano-rectal continence after a traumatic childbirth.

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Light influences sleep and alertness either indirectly through a well-characterized circadian pathway or directly through yet poorly understood mechanisms. Melanopsin (Opn4) is a retinal photopigment crucial for conveying nonvisual light information to the brain. Through extensive characterization of sleep and the electrocorticogram (ECoG) in melanopsin-deficient (Opn4(-/-)) mice under various light-dark (LD) schedules, we assessed the role of melanopsin in mediating the effects of light on sleep and ECoG activity. In control mice, a light pulse given during the habitual dark period readily induced sleep, whereas a dark pulse given during the habitual light period induced waking with pronounced theta (7-10 Hz) and gamma (40-70 Hz) activity, the ECoG correlates of alertness. In contrast, light failed to induce sleep in Opn4(-/-) mice, and the dark-pulse-induced increase in theta and gamma activity was delayed. A 24-h recording under a LD 1-hratio1-h schedule revealed that the failure to respond to light in Opn4(-/-) mice was restricted to the subjective dark period. Light induced c-Fos immunoreactivity in the suprachiasmatic nuclei (SCN) and in sleep-active ventrolateral preoptic (VLPO) neurons was importantly reduced in Opn4(-/-) mice, implicating both sleep-regulatory structures in the melanopsin-mediated effects of light. In addition to these acute light effects, Opn4(-/-) mice slept 1 h less during the 12-h light period of a LD 12ratio12 schedule owing to a lengthening of waking bouts. Despite this reduction in sleep time, ECoG delta power, a marker of sleep need, was decreased in Opn4(-/-) mice for most of the (subjective) dark period. Delta power reached after a 6-h sleep deprivation was similarly reduced in Opn4(-/-) mice. In mice, melanopsin's contribution to the direct effects of light on sleep is limited to the dark or active period, suggesting that at this circadian phase, melanopsin compensates for circadian variations in the photo sensitivity of other light-encoding pathways such as rod and cones. Our study, furthermore, demonstrates that lack of melanopsin alters sleep homeostasis. These findings call for a reevaluation of the role of light on mammalian physiology and behavior.

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The participation of cell adhesion molecules (CAMs) in the establishment of autoimmune and infectious myocarditis is an important matter of investigation and may have therapeutic implication. Trypanosoma cruzi infection induces a CD8-mediated myocarditis in patients with severe cardiomyopathy and experimental animals. Previously, we have proposed that this predominance of CD8+ T-cells is, at least in part, consequence of the differential expression of CAMs on circulating CD8+ lymphocytes. In the present study we investigated the participation of CAMs in shaping the phenotypic nature of the autoimmune CD4-mediated myosin-induced and the CD8-mediated T. cruzi-elicited myocarditis. We provide evidence that the prevalence of a certain T-cell subset inside the inflamed heart reflects the differential profile of the adhesion molecules VLA-4, LFA-1, and ICAM-1 displayed on a large proportion of this particular T-cell population in peripheral blood during the early phase of inflammation. Further, the expression of VCAM-1, ligand for VLA-4, and ICAM-1, counter-receptor for LFA-1, was up-regulated on vascular endothelium and paralleled the entrance of inflammatory cells into the cardiac tissue. Thus, this up-regulated expression of receptors-counter-receptors that regulate T-cell transmigration through the vascular endothelium may have an important role in the pathogenesis of the early phase of both autoimmune and infectious myocarditis.

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Abstract : GABA, the primary inhibitory neurotransmitter, and its receptors play an important role in modulating neuronal activity in the central nervous system and are implicated in many neurological disorders. In this study, GABAA and GABAB receptor subunit expression was visualized by immunohistochemistry in human auditory areas TC (= primary auditory area), TB, and TA. Both hemispheres from nine neurologically normal subjects and from four patients with subacute or chronic stroke were included. In normal brains, GABAA receptor subunit (α1, α2, & β2/3) labeling produced neuropil staining throughout all cortical layers as well as labeling fibers and neurons in layer VI for all auditory areas. Densitometry profiles displayed differences in GABAA subunit expression between primary and non-primary areas. In contrast to the neuropil labeling of GABAA subunits, GABAB1 and GABAB2 subunit immunoreactivity was revealed on neuronal somata and proximal dendritic shafts of pyramidal and non-pyramidal neurons in layers II-III, more strongly on supra- than in infragranular layers. No differences were observed between auditory areas. In stroke cases, we observed a downregulation of the GABAA receptor α2 subunit in granular and infragranular layers, while the other GABAA and the two GABAB receptor subunits remained unchanged. Our results demonstrate a strong presence of GABAA and GABAB receptors in the human auditory cortex, suggesting a crucial role of GABA in shaping auditory responses in the primary and non-primary auditory areas. The differential laminar and area expression of GABAA subunits that we have found in the auditory areas and which is partially different from that in other cortical areas speaks in favor of a fine turning of GABA-ergic transmission in these different compartments. In contrast, GABAB expression displayed laminar, but not areal differences; its basic pattern was also very similar to that of other cortical areas, suggesting a more uniform role within the cerebral cortex. In subacute and chronic stroke, the selective GABAA α2 subunit downregulation is likely to influence postlesional plasticity and susceptibility to medication. The absence of changes in the GABAB receptors suggests different regulation than in other pathological conditions, such as epilepsy, schizophrenia or bipolar disorder, in which a downregulation has been reported. Résumé : GABA, le principal neurotransmetteur inhibiteur, et ses récepteurs jouent un rôle important en tant que modulateur de l'activité neuronale dans le système nerveux central et sont impliqués dans de nombreux désordres neurologiques. Dans cette étude, l'expression des sous-unités des récepteur GABAA et GABAB a été visualisée par immunohistochimie dans les aires auditives du cortex humains: le TC (= aire auditif primaire), le TB, et le TA. Les deux hémisphères de neuf sujets considérés normaux du point de vue neurologique et de quatre patients ayant subis un accident cérébro-vasculaire et se trouvant dans la phase subaiguë ou chronique étaient inclues. Dans les cerveaux normaux, les immunohistochimies contre les sous-unités α1, α2, & β2/3 du récepteur GABAA ont marqué le neuropil dans toutes les couches corticales ainsi que les fibres et les neurones de la couche VI dans toutes les aires auditives. Le profile densitométrique montre des différences dans l'expression des sous-unités du récepteur GABAA entre les aires primaires et non-primaires. Contrairement au marquage de neuropil par les sous-unités du recepteur GABAA, 1'immunoréactivité des sous-unités GABAB1 et GABAB2 a été révélée sur les corps cellulaires neuronaux et les dendrites proximaux des neurones pyramidaux et non-pyramidaux dans les couches II-III et est plus dense dans les couches supragranulaires que dans les couches infragranulaires. Aucune différence n'a été observée entre les aires auditives. Dans des cas lésionnels, nous avons observé une diminution de la sous-unité α2 du récepteur GABAA dans les couches granulaires et infragranulaires, alors que le marquage des autres sous-unités du récepteur GABAA et des deux sous-unités de récepteur GABAB reste inchangé. Nos résultats démontrent une présence forte des récepteurs GABAA et GABAB dans le cortex auditif humain, suggérant un rôle crucial du neurotransmetteur GABA dans la formation de la réponse auditive dans les aires auditives primaires et non-primaires. L'expression différentielle des sous-unités de GABAA entre les couches corticales et entre les aires auditives et qui est partiellement différente de celle observée dans d'autres aires corticales préconise une modulation fine de la transmission GABA-ergic en ces différents compartiments. En revanche, l'expression de GABAB a montré des différences laminaires, mais non régionales ; son motif d'expression de base est également très semblable à celui d'autres aires corticales, suggérant un rôle plus uniforme dans le cortex cérébral. Dans les phases subaiguë et chronique des accidents cérébro-vasculaires, la diminution sélective de la sous-unité α2 du recepteur GABAA est susceptible d'influencer la plasticité et la susceptibilité postlésionnelle au médicament. L'absence de changement pour les récepteurs GABAB suggère que le récepteur est régulé différemment après un accident cerebro-vasculaire par rapport à d'autres conditions pathologiques, telles que l'épilepsie, la schizophrénie ou le désordre bipolaire, dans lesquels une diminution de ces sous-unités a été rapportée.

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BACKGROUND: Glioblastoma, the most common adult primary malignant brain tumor, confers poor prognosis (median survival of 15 months) notwithstanding aggressive treatment. Combination chemotherapy including carmustine (BCNU) or temozolomide (TMZ) with the MGMT inhibitor O6-benzylguanine (O6BG) has been used, but has been associated with dose-limiting hematopoietic toxicity. OBJECTIVE: To assess safety and efficacy of a retroviral vector encoding the O6BG-resistant MGMTP140K gene for transduction and autologous transplantation of hematopoietic stem cells (HSCs) in MGMT unmethylated, newly diagnosed glioblastoma patients in an attempt to chemoprotect bone marrowduring combination O6BG/TMZ therapy. METHODS: Three patients have been enrolled in the first cohort. Patients underwent standard radiation therapy without TMZ followed by G-CSF mobilization, apheresis, and conditioning with 600 mg/m2 BCNU prior to infusion of gene-modified cells. Posttransplant, patients were treated with 28-day cycles of single doseTMZ (472 mg/m2) with 48-hour intravenous O6BG (120 mg/m2 bolus, then 30 mg/m2/d). RESULTS: The BCNU dose was nonmyeloablative with ANC ,500/mL for ≤3 d and nadir thrombocytopenia of 28,000/mL. Gene marking in pre-infusion colony forming units (CFUs) was 70.6%, 79.0%, and 74.0% in Patients 1, 2, and 3, respectively, by CFU-PCR. Following engraftment, gene marking in white blood cells and sorted granulocytes ranged between 0.37-0.84 and 0.33-0.83 provirus copies, respectively, by real-time PCR. Posttransplant gene marking in CFUs from CD34-selected cells ranged from 28.5% to 47.4%. Patients have received 4, 3, and 2 cycles of O6BG/TMZ, respectively, with evidence for selection of gene-modified cells. One patient has received a single dose-escalated cycle at 590 mg/m2 TMZ. No additional extra-hematopoietic toxicity has been observed thus far and all three patients exhibit stable disease at 7-8 months since diagnosis CONCLUSIONS: We believe that these data demonstrate the feasibility of achieving significant engraftment of MGMTP140K-modified cells with a well-tolerated dose of BCNU. Further follow-up will determine whether this approach will allow for further dose escalation of TMZ and improved survival.

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Digital Holographic Microscopy (DHM), is a new imaging technique allowing to provide quantitative phase images with a high accuracy and stability making possible to explore a large variety of relevant processes, occurring on the p.s to day time scale, in the fields including material research as well as cell biology. As a non invasive and real time imaging technique, DHM is particularly well suited for high throughput screening