83 resultados para solid deuterium


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We developed a method of sample preparation using epoxy compound, which was validated in two steps. First, we studied the homogeneity within samples by scanning tubes filled with radioactive epoxy. We found within-sample homogeneity better than 2%. Then, we studied the homogeneity between samples during a 4.5 h dispensing time. The homogeneity between samples was found to be better than 2%. This study demonstrates that we have a validated method, which assures the traceability of epoxy samples.

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Timing effects of radioimmunotherapy (RIT) combined with external-beam radiotherapy (RT) were assessed in human colon carcinoma xenografts. Initially, dose effects of fractionated RT and RIT were evaluated separately. Then, 30 Gy RT (10 fractions over 12 days) were combined with three weekly i.v. injections of 200 microCi of 131I-labeled anti-carcinoembryonic antigen monoclonal antibodies in four different treatment schedules. RIT was given either prior to, concurrently, immediately after, or 2 weeks after RT administration. The longest regrowth delay (RD) of 105 days was observed in mice treated by concurrent administration of RT and RIT, whereas the RDs of RT and RIT alone were 34 and 20 days, respectively. The three sequential combination treatments produced significantly shorter RDs ranging from 62 to 70 days. The tumor response represented by the minimal volume (MV) also showed that concurrent administration of RT and RIT gave the best result, with a mean MV of 4.5% as compared to MVs from 26 to 53% for the three sequential treatments. The results were confirmed in a second experiment, in which a RT of 40 Gy was combined with an identical RIT as above (three injections of 200 microCi of 131I-labeled monoclonal antibodies). At comparable toxicity levels, the maximum tolerated RT or RIT alone gave shorter RDs and less tumor shrinkage compared to simultaneous RT+ RIT. These results may be useful for designing clinical protocols of combined RIT and RT.

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Cytomegalovirus (CMV) remains one of the most common infections after solid organ transplantation, resulting in significant morbidity, graft loss, and occasional mortality. Management of CMV varies considerably among transplant centers. A panel of experts on CMV and solid organ transplant was convened by The Infectious Diseases Section of The Transplantation Society to develop evidence and expert opinion-based consensus guidelines on CMV management including diagnostics, immunology, prevention, treatment, drug resistance, and pediatric issues.

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It has been recently shown (Seddiki, N., B. Santner-Nanan, J. Martinson, J. Zaunders, S. Sasson, A. Landay, M. Solomon, W. Selby, S.I. Alexander, R. Nanan, et al. 2006. J. Exp. Med. 203:1693-1700.) that the expression of interleukin (IL) 7 receptor (R) alpha discriminates between two distinct CD4 T cell populations, both characterized by the expression of CD25, i.e. CD4 regulatory T (T reg) cells and activated CD4 T cells. T reg cells express low levels of IL-7Ralpha, whereas activated CD4 T cells are characterized by the expression of IL-7Ralpha(high). We have investigated the distribution of these two CD4 T cell populations in 36 subjects after liver and kidney transplantation and in 45 healthy subjects. According to a previous study (Demirkiran, A., A. Kok, J. Kwekkeboom, H.J. Metselaar, H.W. Tilanus, and L.J. van der Laan. 2005. Transplant. Proc. 37:1194-1196.), we observed that the T reg CD25(+)CD45RO(+)IL-7Ralpha(low) cell population was reduced in transplant recipients (P < 0.00001). Interestingly, the CD4(+)CD25(+)CD45RO(+)IL-7Ralpha(high) cell population was significantly increased in stable transplant recipients compared with healthy subjects (P < 0.00001), and the expansion of this cell population was even greater in patients with documented humoral chronic rejection compared with stable transplant recipients (P < 0.0001). The expanded CD4(+)CD25(+)CD45RO(+)IL-7Ralpha(high) cell population contained allospecific CD4 T cells and secreted effector cytokines such as tumor necrosis factor alpha and interferon gamma, thus potentially contributing to the mechanisms of chronic rejection. More importantly, CD4(+)IL-7Ralpha(+)and CD25(+)IL-7Ralpha(+) cells were part of the T cell population infiltrating the allograft of patients with a documented diagnosis of chronic humoral rejection. These results indicate that the CD4(+)CD25(+)IL-7Ralpha(+) cell population may represent a valuable, sensitive, and specific marker to monitor allospecific CD4 T cell responses both in blood and in tissues after organ transplantation.

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Introduction Swallowing difficulties, or dysphagia, can occur in anyage group, although it is most common among elderly people. It canaffect patients' ability to take solid oral dosage forms, thus compromisingmedication adherence. Although literature is poor, availabledata show that prevalence in the general population ranges from 25 to60%. Prevalence in community pharmacies needs to be explored.Materials & Methods Community pharmacies were recruited from arandom selection in three Swiss states: Basel-Stadt (BS), Basel-Landschaft (BL) and Lausanne (LA). Patients' ability to swallowsolid oral medications was enquired with a semi-structured interview;the interviewer spent 4 h in each included pharmacy. Each consecutivepatient (18 years and older) entering the pharmacy with aprescription for at least 3 different solid oral forms was enrolled.Study was approved by the Lausanne ethics committee.Results Sixty pharmacies took part in the study (20 in BS, 10 in BL,30 in LA) between March and May 2010. Patient inclusion rate was77.8% (410/527). Prevalence of swallowing disorders was 22.4% (92/410). Patients with swallowing disorders were older (mean age: 67.5± 16 years vs. 63.0 ± 14 years, range 19-96; p = 0.03) and moreoften women (69.6% vs. 59.1%; Chi2 = 3.3, p = 0.04) than patientswithout swallowing disorders. They had on average 4.6 ± 2.7 drugswith a mean number of 5.5 ± 3.3 tablets or capsules to take daily,which didn't differ from the number of drugs taken by patientswithout swallowing difficulties (4.9 ± 2.5 drugs and 5.9 ± 3.5 tablets;n.s.). The difficulty was mainly related to the big size (63%) orthe quality of pill coating (rough, sticky, 14%). Twenty-one patients(37.5%) stated that their swallowing disorders resulted in nonadherence, rated as rarely (12 patients), sometimes (6 patients), veryoften (1 patient) or always (2 patients). According to patients, nopharmacist and only 2 physicians enquired about patients' swallowingissue.Discussion & Conclusion Swallowing difficulties are frequent amongpatients in community pharmacies in Switzerland with an estimatedprevalence of 22%. The problem resulted in non adherence or partialadherence in at least 35% of these patients. However, pharmacists andphysicians did not routinely inquire about the disorder. Guidelinesshould be developed for promoting systematic approaches of patientsin community pharmacies.

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Antifreeze proteins (AFPs) inhibit ice growth at sub-zero temperatures. The prototypical type-III AFPs have been extensively studied, notably by X-ray crystallography, solid-state and solution NMR, and mutagenesis, leading to the identification of a compound ice-binding surface (IBS) composed of two adjacent ice-binding sections, each which binds to particular lattice planes of ice crystals, poisoning their growth. This surface, including many hydrophobic and some hydrophilic residues, has been extensively used to model the interaction of AFP with ice. Experimentally observed water molecules facing the IBS have been used in an attempt to validate these models. However, these trials have been hindered by the limited capability of X-ray crystallography to reliably identify all water molecules of the hydration layer. Due to the strong diffraction signal from both the oxygen and deuterium atoms, neutron diffraction provides a more effective way to determine the water molecule positions (as D(2) O). Here we report the successful structure determination at 293 K of fully perdeuterated type-III AFP by joint X-ray and neutron diffraction providing a very detailed description of the protein and its solvent structure. X-ray data were collected to a resolution of 1.05 Å, and neutron Laue data to a resolution of 1.85 Å with a "radically small" crystal volume of 0.13 mm(3). The identification of a tetrahedral water cluster in nuclear scattering density maps has allowed the reconstruction of the IBS-bound ice crystal primary prismatic face. Analysis of the interactions between the IBS and the bound ice crystal primary prismatic face indicates the role of the hydrophobic residues, which are found to bind inside the holes of the ice surface, thus explaining the specificity of AFPs for ice versus water.

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Infectious diseases (ID) are a major cause of morbidity and mortality after SOT. Since May 2008, the STCS has registered 95% of all SOT recipients in Switzerland. The extensive data set includes pre- and post-transplant variables that are prospectively collected at transplantation, 6 months post-transplant, and yearly thereafter. All ID events are recorded using internationally validated defi nitions. We obtained data from 1101 patients (79 heart, 685 kidney, 29 kidney-pancreas, 212 liver, and 96 lung transplants). So far the median observation times were 0.8 (IQR 0.3-1.4; heart); 1.1 (0.6-1.8, kidney); 1.1 (0.6-1.9, kidney-pancreas); 1.0 (0.5-1.7, liver); and 0.9 years (0.5-1.5, lung). The highest rates of proven or probable ID events were seen in lung (76%), followed by liver (64%), heart (62%), kidney-pancreas (62%), kidney (58%). During the observation period, ID was the cause of death in 19 patients (1.7%). Rates of infections per person-years according to pathogen and type of transplantation are shown in Figure 1. The data indicate that virus infections are only second after bacteria whereas fungi occur at relatively low rates. This prospective and standardized long-term collection of all ID events will allow a comprehensive assessment of the burden of ID across all SOT types in Switzerland. Regular analysis will identify new trends, serve as a quality control and help design anti-infectious interventions aiming at increasing safety and improving overall transplantation outcome.

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PURPOSE: Although the central role of the immune system for tumor prognosis is generally accepted, a single robust marker is not yet available. EXPERIMENTAL DESIGN: On the basis of receiver operating characteristic analyses, robust markers were identified from a 60-gene B cell-derived metagene and analyzed in gene expression profiles of 1,810 breast cancer; 1,056 non-small cell lung carcinoma (NSCLC); 513 colorectal; and 426 ovarian cancer patients. Protein and RNA levels were examined in paraffin-embedded tissue of 330 breast cancer patients. The cell types were identified with immunohistochemical costaining and confocal fluorescence microscopy. RESULTS: We identified immunoglobulin κ C (IGKC) which as a single marker is similarly predictive and prognostic as the entire B-cell metagene. IGKC was consistently associated with metastasis-free survival across different molecular subtypes in node-negative breast cancer (n = 965) and predicted response to anthracycline-based neoadjuvant chemotherapy (n = 845; P < 0.001). In addition, IGKC gene expression was prognostic in NSCLC and colorectal cancer. No association was observed in ovarian cancer. IGKC protein expression was significantly associated with survival in paraffin-embedded tissues of 330 breast cancer patients. Tumor-infiltrating plasma cells were identified as the source of IGKC expression. CONCLUSION: Our findings provide IGKC as a novel diagnostic marker for risk stratification in human cancer and support concepts to exploit the humoral immune response for anticancer therapy. It could be validated in several independent cohorts and carried out similarly well in RNA from fresh frozen as well as from paraffin tissue and on protein level by immunostaining.

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Since new technologies based on solid phase assays (SPA) have been routinely incorporated in the transplant immunology laboratory, the presence of pretransplantation donor-specific antibodies (DSA) against human leukocyte antigen (HLA) molecules has generally been considered as a risk factor for acute rejection (AR) and, in particular, for acute humoral rejection (AHR). We retrospectively studied 113 kidney transplant recipients who had negative prospective T-cell and B-cell complement-dependent cytotoxicity (CDC) crossmatches at the time of transplant. Pretransplantation sera were screened for the presence of circulating anti-HLA antibody and DSA by using highly sensitive and HLA-specific Luminex assay, and the results were correlated with AR and AHR posttransplantation. We found that approximately half of our patient population (55/113, 48.7%) had circulating anti-HLA antibody pretransplantation. Of 113 patients, 11 (9.7%) had HLA-DSA. Of 11 rejection episodes post-transplant, only two patients had pretransplantation DSA, of whom one had a severe AHR (C4d positive). One-year allograft survival was similar between the pretransplantation DSA-positive and -negative groups. Number, class, and intensity of pretransplantation DSA, as well as presensitizing events, could not predict AR. We conclude that, based on the presence of pretransplantation DSA, post-transplantation acute rejections episodes could not have been predicted. The only AHR episode occurred in a recipient with pretransplantation DSA. More work should be performed to better delineate the precise clinical significance of detecting low titers of DSA before transplantation.

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Since the early 1980s high dose chemotherapy with autologous hematopoietic stem cell support was adopted by many oncologists as a potentially curative option for solid tumors, supported by a strong rationale from laboratory studies and apparently convincing results of early phase II studies. As a result, the number and size of randomized trials comparing this approach with conventional chemotherapy initiated (and often abandoned before completion) to prove or disprove its value was largely insufficient. In fact, with the possible exception of breast carcinoma, the benefit of a greater escalation of dose of chemotherapy with stem cell support in solid tumors is still unsettled and many oncologists believe that this approach should cease. In this article, we critically review and comment on the data from studies of high dose chemotherapy so far reported in adult patients with small cell lung cancer, ovarian cancer, germ cell tumors and sarcomas.

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Over the past few years, the therapeutic potential of Treg has been highlighted in the field of autoimmune diseases and after allogeneic transplantation. The first hurdle for the therapeutic use of Treg is their insufficient numbers in non-manipulated individuals, in particular when facing strong immune activation and expanding effector cells, such as in response to an allograft. Here we review current approaches being explored for Treg expansion in the perspective of clinical therapeutic protocols. We describe different Treg subsets that could be suitable for clinical application, as well as discuss factors such as the required dose of Treg, their antigen-specificity and in vivo stability, that have to be considered for optimal Treg-based immunotherapy in transplantation. Since Treg may not be sufficient as stand-alone therapy for solid organ transplantation in humans, we draw attention to possible hurdles and combination therapy with immunomodulatory drugs that could possibly improve the in vivo efficacy of Treg.

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Goal: To validate oral vatgancictovir (VGC) in the prophylaxis of CMV infection in Lung (Lu) and Liver (L) recipients and in the treatment of CMV infection/disease in solid organ transplant recipients, using pharmacokinetic and pharmacodynamic studies in comparison with i/v gancicLovir (GCV). Methods: patients undergoing organ transpLantation donor or recipient CMV-seropositive receiving VGC prophylaxis for a period of 3 months (D+/R- Lung recipients, 6 months) were enroLLed. Heart (H), Lu, and L recipients received 900mg VGC q.d., adjusted to kidney (K) function. No K recipients received more than 450mg of VGC q.d. GCV trough (Ctrough) and peak (Cpeak = 3 hours after drug administration) LeveLs, and CMV DNA were measured at 7, 30, and 60 days post-transpLant (prophyLactic study). Patients who developed CMV infection/disease after stopping prophylaxis were treated with VGC (1800mg per day adjusted to K function and GCV blood LeveLs). GCV trough and peak LeveLs, and CMV DNA were measured weekly for the first 3 weeks and biweekly thereafter, until therapy cessation (therapeutic study). PLasma concentration of GCV is measured by HPLC. Results: In the first 8 prophyLaxed patients (6 K, and 1 L and 1 H transplant recipient) of 450mg VGC q.d., the average GCV concentration was 0.5±0.3 mg/t at trough, and 3.9±l.0mg/t 3 hours after administration. Inter-patient variability was substantiaL, especiaLLy for Ctrough (63% of total variance), which correlated with the patient's estimated gtomerutar filtration rate (r square = 42%). No CMV DNA was detected during VGC prophy- Laxis. Two patients (1 H and 1 L) were treated for Late CMV disease. Average GCV Cpeak were 8.9±2.3 mg/L and 4.6±0.5 rag/L, and GCV Ctrough were 2.0±0.9 mg/t and 1.6±0.2 mg/t respectively in each patient during induction phase. VGC treatment afforded a decrease in CMV DNA from 5.2 and 4.4 Log copies/10E6 cettutes at week 0, to 3.9 and 3.0 at week 1, and 3.3 and 2.1 at week 3, respectively.

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Cancer immunotherapy has great promise, but is limited by diverse mechanisms used by tumors to prevent sustained antitumor immune responses. Tumors disrupt antigen presentation, T/NK-cell activation, and T/NK-cell homing through soluble and cell-surface mediators, the vasculature, and immunosuppressive cells such as myeloid-derived suppressor cells and regulatory T cells. However, many molecular mechanisms preventing the efficacy of antitumor immunity have been identified and can be disrupted by combination immunotherapy. Here, we examine immunosuppressive mechanisms exploited by tumors and provide insights into the therapies under development to overcome them, focusing on lymphocyte traffic.