150 resultados para LOW-DOSE METHOTREXATE


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Background Airborne particles entering the respiratory tract may interact with the apical plasma membrane (APM) of epithelial cells and enter them. Differences in the entering mechanisms of fine (between 0.1 μm and 2.5 μm) and ultrafine ( ≤ 0.1 μm) particles may be associated with different effects on the APM. Therefore, we studied particle-induced changes in APM surface area in relation to applied and intracellular particle size, surface and number. Methods Human pulmonary epithelial cells (A549 cell line) were incubated with various concentrations of different sized fluorescent polystyrene spheres without surface charge (∅ fine – 1.062 μm, ultrafine – 0.041 μm) by submersed exposure for 24 h. APM surface area of A549 cells was estimated by design-based stereology and transmission electron microscopy. Intracellular particles were visualized and quantified by confocal laser scanning microscopy. Results Particle exposure induced an increase in APM surface area compared to negative control (p < 0.01) at the same surface area concentration of fine and ultrafine particles a finding not observed at low particle concentrations. Ultrafine particle entering was less pronounced than fine particle entering into epithelial cells, however, at the same particle surface area dose, the number of intracellular ultrafine particles was higher than that of fine particles. The number of intracellular particles showed a stronger increase for fine than for ultrafine particles at rising particle concentrations. Conclusion This study demonstrates a particle-induced enlargement of the APM surface area of a pulmonary epithelial cell line, depending on particle surface area dose. Particle uptake by epithelial cells does not seem to be responsible for this effect. We propose that direct interactions between particle surface area and cell membrane cause the enlargement of the APM.

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Glucocorticoids are often applied in neonatology and perinatology to fight the problems of respiratory distress and chronic lung disease. There are, however, many controversies regarding the adverse side effects and long-term clinical benefits of this therapeutic approach. In rats, glucocorticoids are known to seriously impair the formation of alveoli when applied during the first two postnatal weeks even at very low dosage. The current study investigates short-term and long-term glucocorticoid effects on the rat lung by means of morphologic and morphometric observations at light and electron microscopic levels. Application of a high-dosage protocol for only few days resulted in a marked acceleration of lung development with a precocious microvascular maturation resulting in single capillary network septa in the first 4 postnatal days. By postnatal d 10, the lung morphologic phenotype showed a step back in the maturational state, with an increased number of septa with double capillary layer, followed by an exceptional second round of the alveolarization process. As a result of this process, there was an almost complete recovery in the parenchymal lung structure by postnatal d 36, and by d 60, there were virtually no qualitative or quantitative differences between experimental and control rats. These findings indicate that both dosage and duration of glucocorticoid therapy in the early postnatal period are very critical with respect to lung development and maturation and that a careful therapeutic strategy can minimize late sequelae of treatment.

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Background: Synchronization programs have become standard in the dairy industry. In Switzerland, these programs are used but newly. The objective of this study was A) to estimate the pregnancy rate after a Select-Synch protocol in- cluding a low dosage of progesterone in CIDR (1.38 g). As a second step B) this pregnancy rate should be compared to cows from another Swiss study that used a Select-Synch protocol with the 1.9 g insert (Rudolph et al., 2011). Methods: A) 196 cows were included in the study. Cows received a CIDR 1.38 g and 2.5 ml of buserelin i.m. on d 0. On d 7, the CIDR insert was removed and 5 ml of dinoprost was administered i.m. On d 0 a milk sample for progesterone analysis was taken. Pregnancy was determined at or more than 35 days after artificial insemination. B) The 1.38 g group and the 1.9 g group were compared as to cow and farm factors, number of preceding AI’s, gynecological and uterine pretreat- ment and treatment itself. A forward selection procedure was used (test result considered significant if p-value  0.05). Results: A) The pregnancy rate, using the Select-Synch protocol with the CIDR 1.38 g was 44.4%. B) The CIDR 1.9 g Select-Synch group revealed a pregnancy rate of 50.4% (Rudolph et al., 2011). Significant differences between the groups were not found. Conclusion: The 1.38 g CIDR-Select-Synch protocol may be recommended for multiparous dairy cows. The pregnancy rate compared to the 1.9 g CIDR-Select-Synch protocol was 8% lower, but this difference was not significant.

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OBJECTIVES The aim of this phantom study was to minimize the radiation dose by finding the best combination of low tube current and low voltage that would result in accurate volume measurements when compared to standard CT imaging without significantly decreasing the sensitivity of detecting lung nodules both with and without the assistance of CAD. METHODS An anthropomorphic chest phantom containing artificial solid and ground glass nodules (GGNs, 5-12 mm) was examined with a 64-row multi-detector CT scanner with three tube currents of 100, 50 and 25 mAs in combination with three tube voltages of 120, 100 and 80 kVp. This resulted in eight different protocols that were then compared to standard CT sensitivity (100 mAs/120 kVp). For each protocol, at least 127 different nodules were scanned in 21-25 phantoms. The nodules were analyzed in two separate sessions by three independent, blinded radiologists and computer-aided detection (CAD) software. RESULTS The mean sensitivity of the radiologists for identifying solid lung nodules on a standard CT was 89.7% ± 4.9%. The sensitivity was not significantly impaired when the tube and current voltage were lowered at the same time, except at the lowest exposure level of 25 mAs/80 kVp [80.6% ± 4.3% (p = 0.031)]. Compared to the standard CT, the sensitivity for detecting GGNs was significantly lower at all dose levels when the voltage was 80 kVp; this result was independent of the tube current. The CAD significantly increased the radiologists' sensitivity for detecting solid nodules at all dose levels (5-11%). No significant volume measurement errors (VMEs) were documented for the radiologists or the CAD software at any dose level. CONCLUSIONS Our results suggest a CT protocol with 25 mAs and 100 kVp is optimal for detecting solid and ground glass nodules in lung cancer screening. The use of CAD software is highly recommended at all dose levels.

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OBJECTIVES It is still debated if pre-existing minority drug-resistant HIV-1 variants (MVs) affect the virological outcomes of first-line NNRTI-containing ART. METHODS This Europe-wide case-control study included ART-naive subjects infected with drug-susceptible HIV-1 as revealed by population sequencing, who achieved virological suppression on first-line ART including one NNRTI. Cases experienced virological failure and controls were subjects from the same cohort whose viraemia remained suppressed at a matched time since initiation of ART. Blinded, centralized 454 pyrosequencing with parallel bioinformatic analysis in two laboratories was used to identify MVs in the 1%-25% frequency range. ORs of virological failure according to MV detection were estimated by logistic regression. RESULTS Two hundred and sixty samples (76 cases and 184 controls), mostly subtype B (73.5%), were used for the analysis. Identical MVs were detected in the two laboratories. 31.6% of cases and 16.8% of controls harboured pre-existing MVs. Detection of at least one MV versus no MVs was associated with an increased risk of virological failure (OR = 2.75, 95% CI = 1.35-5.60, P = 0.005); similar associations were observed for at least one MV versus no NRTI MVs (OR = 2.27, 95% CI = 0.76-6.77, P = 0.140) and at least one MV versus no NNRTI MVs (OR = 2.41, 95% CI = 1.12-5.18, P = 0.024). A dose-effect relationship between virological failure and mutational load was found. CONCLUSIONS Pre-existing MVs more than double the risk of virological failure to first-line NNRTI-based ART.

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BACKGROUND To determine the 5-year outcome after high-dose-rate brachytherapy (HDR-BT) as a monotherapy. METHODS Between 10/2003 and 06/2006, 36 patients with low (28) and intermediate (8) risk prostate cancer were treated by HDR-BT monotherapy. All patients received one implant and 4 fractions of 9.5 Gy within 48 hours for a total prescribed dose (PD) of 38 Gy. Five patients received concomitant androgen deprivation therapy (ADT). Toxicity was scored according to the common terminology criteria for adverse events from the National Cancer Institute (CTCAE) version 3.0. Biochemical recurrence was defined according to the Phoenix criteria and analyzed using the Kaplan Meier method. Predictors for late grade 3 GU toxicity were analyzed using univariate and multivariate Cox regression analyses. RESULTS The median follow-up was 6.9 years (range, 1.5-8.0 years). Late grade 2 and 3 genitourinary (GU) toxicity was observed in 10 (28%) and 7 (19%) patients, respectively. The actuarial proportion of patients with late grade 3 GU toxicity at 5 years was 17.7%. Late grade 2 and 3 gastrointestinal (GI) toxicities were not observed. The crude erectile function preservation rate in patients without ADT was 75%. The 5 year biochemical recurrence-free survival (bRFS) rate was 97%. Late grade 3 GU toxicity was associated with the urethral volume (p = 0.001) and the urethral V120 (urethral volume receiving ≥120% of the PD; p = 0.0005) after multivariate Cox regression. CONCLUSIONS After HDR-BT monotherapy late grade 3 GU was observed relatively frequently and was associated with the urethral V120. GI toxicity was negligible, the erectile function preservation rate and the bRFS rate was excellent.

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BACKGROUND The optimal management of high-risk prostate cancer remains uncertain. In this study we assessed the safety and efficacy of a novel multimodal treatment paradigm for high-risk prostate cancer. METHODS This was a prospective phase II trial including 35 patients with newly diagnosed high-risk localized or locally advanced prostate cancer treated with high-dose intensity-modulated radiation therapy preceded or not by radical prostatectomy, concurrent intensified-dose docetaxel-based chemotherapy and long-term androgen deprivation therapy. Primary endpoint was acute and late toxicity evaluated with the Common Terminology Criteria for Adverse Events version 3.0. Secondary endpoint was biochemical and clinical recurrence-free survival explored with the Kaplan-Meier method. RESULTS Acute gastro-intestinal and genito-urinary toxicity was grade 2 in 23% and 20% of patients, and grade 3 in 9% and 3% of patients, respectively. Acute blood/bone marrow toxicity was grade 2 in 20% of patients. No acute grade ≥ 4 toxicity was observed. Late gastro-intestinal and genito-urinary toxicity was grade 2 in 9% of patients each. No late grade ≥ 3 toxicity was observed. Median follow-up was 63 months (interquartile range 31-79). Actuarial 5-year biochemical and clinical recurrence-free survival rate was 55% (95% confidence interval, 35-75%) and 70% (95% confidence interval, 52-88%), respectively. CONCLUSIONS In our phase II trial testing a novel multimodal treatment paradigm for high-risk prostate cancer, toxicity was acceptably low and mid-term oncological outcome was good. This treatment paradigm, thus, may warrant further evaluation in phase III randomized trials.

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Interactions between stressors contribute to the recently reported increase in losses of honey bee colonies. Here we demonstrated that a synergistic effect on mortality by the low toxic, commonly used neonicotinoid thiacloprid and the nearly ubiquitous gut parasite Nosemaceranae is dependent on the pesticide dose. Furthermore, thiacloprid had a negative influence on N.ceranae reproduction. Our results highlight that interactions among honey bee health stressors can be dynamic and should be studied across a broader range of combinations.

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OBJECTIVES In this phantom CT study, we investigated whether images reconstructed using filtered back projection (FBP) and iterative reconstruction (IR) with reduced tube voltage and current have equivalent quality. We evaluated the effects of different acquisition and reconstruction parameter settings on image quality and radiation doses. Additionally, patient CT studies were evaluated to confirm our phantom results. METHODS Helical and axial 256 multi-slice computed tomography scans of the phantom (Catphan(®)) were performed with varying tube voltages (80-140kV) and currents (30-200mAs). 198 phantom data sets were reconstructed applying FBP and IR with increasing iterations, and soft and sharp kernels. Further, 25 chest and abdomen CT scans, performed with high and low exposure per patient, were reconstructed with IR and FBP. Two independent observers evaluated image quality and radiation doses of both phantom and patient scans. RESULTS In phantom scans, noise reduction was significantly improved using IR with increasing iterations, independent from tissue, scan-mode, tube-voltage, current, and kernel. IR did not affect high-contrast resolution. Low-contrast resolution was also not negatively affected, but improved in scans with doses <5mGy, although object detectability generally decreased with the lowering of exposure. At comparable image quality levels, CTDIvol was reduced by 26-50% using IR. In patients, applying IR vs. FBP resulted in good to excellent image quality, while tube voltage and current settings could be significantly decreased. CONCLUSIONS Our phantom experiments demonstrate that image quality levels of FBP reconstructions can also be achieved at lower tube voltages and tube currents when applying IR. Our findings could be confirmed in patients revealing the potential of IR to significantly reduce CT radiation doses.

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BACKGROUND: In clinical practise the high dose ACTH stimulation test (HDT) is frequently used in the assessment of adrenal insufficiency (AI). However, there is uncertainty regarding optimal time-points and number of blood samplings. The present study compared the utility of a single cortisol value taken either 30 or 60 minutes after ACTH stimulation with the traditional interpretation of the HDT. METHODS: Retrospective analysis of 73 HDT performed at a single tertiary endocrine centre. Serum cortisol was measured at baseline, 30 and 60 minutes after intravenous administration of 250 µg synthetic ACTH1-24. Adrenal insufficiency (AI) was defined as a stimulated cortisol level <550 nmol/l. RESULTS: There were twenty patients (27.4%) who showed an insufficient rise in serum cortisol using traditional HDT criteria and were diagnosed to suffer from AI. There were ten individuals who showed insufficient cortisol values after 30 minutes, rising to sufficient levels at 60 minutes. All patients revealing an insufficient cortisol response result after 60 minutes also had an insufficient result after 30 minutes. The cortisol value taken after 30 minutes did not add incremental diagnostic value in any of the cases under investigation compared with the 60 minutes' sample. CONCLUSIONS: Based on the findings of the present analysis the utility of a cortisol measurement 30 minutes after high dose ACTH injection was low and did not add incremental diagnostic value to a single measurement after 60 minutes.

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BACKGROUND Inability to predict the therapeutic effect of a drug in individual pain patients prolongs the process of drug and dose finding until satisfactory pharmacotherapy can be achieved. Many chronic pain conditions are associated with hypersensitivity of the nervous system or impaired endogenous pain modulation. Pharmacotherapy often aims at influencing these disturbed nociceptive processes. Its effect might therefore depend on the extent to which they are altered. Quantitative sensory testing (QST) can evaluate various aspects of pain processing and might therefore be able to predict the analgesic efficacy of a given drug. In the present study three drugs commonly used in the pharmacological management of chronic low back pain are investigated. The primary objective is to examine the ability of QST to predict pain reduction. As a secondary objective, the analgesic effects of these drugs and their effect on QST are evaluated. METHODS/DESIGN In this randomized, double blinded, placebo controlled cross-over study, patients with chronic low back pain are randomly assigned to imipramine, oxycodone or clobazam versus active placebo. QST is assessed at baseline, 1 and 2 h after drug administration. Pain intensity, side effects and patients' global impression of change are assessed in intervals of 30 min up to two hours after drug intake. Baseline QST is used as explanatory variable to predict drug effect. The change in QST over time is analyzed to describe the pharmacodynamic effects of each drug on experimental pain modalities. Genetic polymorphisms are analyzed as co-variables. DISCUSSION Pharmacotherapy is a mainstay in chronic pain treatment. Antidepressants, anticonvulsants and opioids are frequently prescribed in a "trial and error" fashion, without knowledge however, which drug suits best which patient. The present study addresses the important need to translate recent advances in pain research to clinical practice. Assessing the predictive value of central hypersensitivity and endogenous pain modulation could allow for the implementation of a mechanism-based treatment strategy in individual patients. TRIAL REGISTRATION Clinicaltrials.gov, NCT01179828.

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PURPOSE Standard dose of external beam radiotherapy seems to be insufficient for satisfactory control of loco-regionally advanced cervical cancer. Aim of our study is to evaluate the outcome as well as early and chronic toxicities in patients with loco-regionally advanced cervical cancer, treated with dose escalated intensity modulated radiotherapy (IMRT) combined with cisplatin chemotherapy. MATERIAL AND METHODS Thirty-nine patients with cervical carcinoma FIGO stage IB2 - IVA were treated with curative intent between 2006 and 2010. The dose of 50.4 Gy was prescribed to the elective pelvic nodal volume. Primary tumors < 4 cm in diameter (n = 6; 15.4 %) received an external beam radiotherapy (EBRT) boost of 5.4 Gy, primary tumors > 4 cm in diameter (n = 33; 84.6 %) received an EBRT boost of 9 Gy. Patients with positive lymph nodes detected with (18)FDG-PET/CT (n = 22; 56.4 %) received a boost to a total dose of 59.4 - 64.8 Gy. The para-aortic region was included in the radiation volume in 8 (20.5 %) patients and in 5 (12.8 %) patients the para-aortic macroscopic lymph nodes received an EBRT boost. IMRT was followed with a 3D planned high dose rate intrauterine brachytherapy given to 36 (92.3 %) patients with a total dose ranging between 15-18 Gy in three fractions (single fraction: 4-6.5 Gy). Patients without contraindications (n = 31/79.5 %) received concomitantly a cisplatin-based chemotherapy (40 mg/kg) weekly. Toxicities were graded according to the common terminology criteria for adverse events (CTCAE v 4.0). RESULTS Mean overall survival for the entire cohort was 61.1 months (±3.5 months). Mean disease free survival was 47.2 months (±4.9 months) and loco-regional disease free survival was 55.2 months (±4.4 months). 65 % of patients developed radiotherapy associated acute toxicities grade 1, ca. 30 % developed toxicities grade 2 and just two (5.2 %) patients developed grade 3 toxicities, one acute diarrhea and one acute cystitis. 16 % of patients had chronic toxicities grade 1, 9 % grade 2 and one patient (2.6 %) toxicities grade 3 in the form of vaginal dryness. CONCLUSION Dose escalated IMRT appears to have a satisfactory outcome with regards to mean overall survival, disease free and loco-regional disease free survival, whereas the treatment-related toxicities remain reasonably low.

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PURPOSE Patients with biochemical failure (BF) after radical prostatectomy may benefit from dose-intensified salvage radiation therapy (SRT) of the prostate bed. We performed a randomized phase III trial assessing dose intensification. PATIENTS AND METHODS Patients with BF but without evidence of macroscopic disease were randomly assigned to either 64 or 70 Gy. Three-dimensional conformal radiation therapy or intensity-modulated radiation therapy/rotational techniques were used. The primary end point was freedom from BF. Secondary end points were acute toxicity according to the National Cancer Institute Common Terminology Criteria for Adverse Events (version 4.0) and quality of life (QoL) according to the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaires C30 and PR25. RESULTS Three hundred fifty patients were enrolled between February 2011 and April 2014. Three patients withdrew informed consent, and three patients were not eligible, resulting in 344 patients age 48 to 75 years in the safety population. Thirty patients (8.7%) had grade 2 and two patients (0.6%) had grade 3 genitourinary (GU) baseline symptoms. Acute grade 2 and 3 GU toxicity was observed in 22 patients (13.0%) and one patient (0.6%), respectively, with 64 Gy and in 29 patients (16.6%) and three patients (1.7%), respectively, with 70 Gy (P = .2). Baseline grade 2 GI toxicity was observed in one patient (0.6%). Acute grade 2 and 3 GI toxicity was observed in 27 patients (16.0%) and one patient (0.6%), respectively, with 64 Gy, and in 27 patients (15.4%) and four patients (2.3%), respectively, with 70 Gy (P = .8). Changes in early QoL were minor. Patients receiving 70 Gy reported a more pronounced and clinically relevant worsening in urinary symptoms (mean difference in change score between arms, 3.6; P = .02). CONCLUSION Dose-intensified SRT was associated with low rates of acute grade 2 and 3 GU and GI toxicity. The impact of dose-intensified SRT on QoL was minor, except for a significantly greater worsening in urinary symptoms.

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BACKGROUND Air enema under fluoroscopy is a well-accepted procedure for the treatment of childhood intussusception. However, the reported radiation doses of pneumatic reduction with conventional fluoroscopy units have been high in decades past. OBJECTIVE To compare current radiation doses at our institution to past doses reported by others for fluoroscopic-guided pneumatic reduction of ileo-colic intussusception in children. MATERIALS AND METHODS Since 2007 radiologists and residents in our department who perform reduction of intussusceptions have received a radiation risk training. We retrospectively analyzed the data of 45 children (5 months-8 years) who underwent a total of 48 pneumatic reductions of ileo-colic intussusception between 2008 and 2012. We analyzed data for screening time and dose area product (DAP) and compared these data to those reported up to and including the year 2000. RESULTS Our mean screening time measured by the DAP-meter was 53.8 s (range 1-320 s, median 33.0 s). The mean DAP was 11.4 cGy ∙ cm(2) (range 1-145 cGy ∙ cm(2), median 5.45 cGy ∙ cm(2)). There was one bowel perforation, in a 1-year-old boy requiring surgical revision. Only three studies in the literature presented radiation exposure results on children who received pneumatic or hydrostatic reduction of intussusception under fluoroscopy. Screening times and dose area products in those studies, which were published in the 1990 s and in the year 2000, were substantially higher than those in our sample. CONCLUSION Low-frequency pulsed fluoroscopy and other dose-saving keys as well as the radiation risk training might have helped to improve the quality of the procedure in terms of radiation exposure.

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Pregnant BALB/c mice have been widely used as an in vivo model to study Neospora caninum infection biology and to provide proof-of-concept for assessments of drugs and vaccines against neosporosis. The fact that this model has been used with different isolates of variable virulence, varying infection routes and differing methods to prepare the parasites for infection, has rendered the comparison of results from different laboratories impossible. In most studies, mice were infected with similar number of parasites (2 × 10(6)) as employed in ruminant models (10(7) for cows and 10(6) for sheep), which seems inappropriate considering the enormous differences in the weight of these species. Thus, for achieving meaningful results in vaccination and drug efficacy experiments, a refinement and standardization of this experimental model is necessary. Thus, 2 × 10(6), 10(5), 10(4), 10(3) and 10(2) tachyzoites of the highly virulent and well-characterised Nc-Spain7 isolate were subcutaneously inoculated into mice at day 7 of pregnancy, and clinical outcome, vertical transmission, parasite burden and antibody responses were compared. Dams from all infected groups presented nervous signs and the percentage of surviving pups at day 30 postpartum was surprisingly low (24%) in mice infected with only 10(2) tachyzoites. Importantly, infection with 10(5) tachyzoites resulted in antibody levels, cerebral parasite burden in dams and 100% mortality rate in pups, which was identical to infection with 2 × 10(6) tachyzoites. Considering these results, it is reasonable to lower the challenge dose to 10(5) tachyzoites in further experiments when assessing drugs or vaccine candidates.