171 research outputs found
From ultraslow to extremely fast dynamics in sodium nitrate
Increasing dynamics in solids featuring nuclei subjected to second-order quadrupolar interactions lead to central-transition spectra that undergo two consecutive line-shaped transitions. Conventional motional narrowing occurs when the molecular exchange rate is on the order of the strength of the dominant interaction. In a second step, the resulting intermediately narrowed spectra change further when the motion becomes faster than the Larmor precession rate, leading to terminally narrowed spectra that can display a residual quadrupolar shift. We derive analytic expressions for this shift and analyze the quadrupolar central-transition spectra in terms of CN symmetrical cone models. Increasing the number of sites to N ≥ 3, the terminally narrowed spectra remain unaltered, while the intermediately narrowed spectra remain unaltered only for N ≥ 5. This finding relates to the different (cubic vs. icosahedral) symmetries that are required to average out the spatial second- and fourth-rank terms in the second-order quadrupolar interaction. Following recent work (Hung et al., Solid State Nucl Magn Reson 84:14–19, 2017), 17O NMR is applied to examine the three-site rotation of the nitrate group in NaNO3. Line shapes are measured and analyzed, and in addition to prior work, satellite-transition and stimulated-echo experiments are carried out. The final-state amplitudes extracted from the latter are reproduced using model calculations. It is shown how two-dimensional exchange spectra relating to N-site cone motions can be decomposed in terms of effective two-site-jump spectra. This latter approach is successfully tested for NaNO3
A Randomized Phase III Trial Investigating 2 Gy TBI Vs. Flu/2 Gy TBI Conditioning for HLA-Matched Related Donor Hematopoietic Cell Transplantation (HCT): Tempo of CD3 and NK Cell Engraftment Determines Relapse and Progression Free Survival in Patients with Hematologic
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Low-dose total body irradiation and fludarabine conditioningfor HLA class I-mismatched donor stem cell transplantation and immunologic recovery in patients with hematologic malignancies: a multicenter trial.
Fludarabine/2 Gy TBI is Superior to 2 Gy TBI as Conditioning for HLA-Matched Related HCT: A Phase III Randomized Trial.
AbstractThe risks and benefits of adding fludarabine to a 2-Gy total body irradiation (TBI) nonmyeloablative regimen are unknown. For this reason, we conducted a prospective randomized trial comparing 2-Gy TBI alone, or in combination with 90 mg/m2 fludarabine (FLU/TBI), before transplantation of peripheral blood stem cells from HLA-matched related donors. Eighty-five patients with hematological malignancies were randomized to be conditioned with TBI alone (n = 44) or FLU/TBI (n = 41). All patients had initial engraftment. Two graft rejections were observed, both in the TBI group. Infection rates, nonrelapse mortality, and graft-versus-host disease (GVHD) were similar between groups. Three-year overall survival was lower in the TBI group (54% versus 65%; hazard ratio [HR], .57; P = .09), with higher incidences of relapse/progression (55% versus 40%; HR, .55; P = .06), relapse-related mortality (37% versus 28%; HR, .53; P = .09), and a lower progression-free survival (36% versus 53%; HR, .56; P = .05). Median donor T cell chimerism levels were significantly lower in the TBI group at days 28 (61% versus 90%; P < .0001) and 84 (68% versus 92%; P < .0001), as was NK cell chimerism on day 28 (75% versus 96%; P = .0005). In conclusion, this randomized trial demonstrates the importance of fludarabine in augmenting the graft-versus-tumor effect by ensuring prompt and durable high-level donor engraftment early after transplantation
Establishing a Target Exposure for Once-Daily Intravenous Busulfan Given with Fludarabine and Thymoglobulin before Allogeneic Transplantation
AbstractA combination of fludarabine (Flu) and daily i.v. busulfan (Bu) is well tolerated and effective in patients undergoing allogeneic hematopoietic stem cell transplantation. Although there is some evidence that Bu exposures exceeding 6000 μM/min may lead to excessive toxicity, there is little information on the effect of exposures below this level on outcomes. We studied Bu exposure, as measured by area under the concentration-time curve (AUC), in 158 patients with various hematologic malignancies in an attempt to identify an optimal range for targeted therapy. The preparative chemotherapy regimen comprised Flu 50 mg/m2 on days -6 to -2 and i.v. Bu 3.2 mg/kg on days -5 to -2 inclusive. Graft-versus-host disease (GVHD) prophylaxis included methotrexate, cyclosporin A, and antithymocyte globulin. Patients with Bu exposures below the median AUC of 4439 μM/min were at increased risk for acute GVHD grade II-IV (hazard ratio [HR], 2.30; 95% confidence interval [CI], 1.19 to 4.49; P = .014). Those in the highest and lowest Bu exposure quartiles (daily AUC <3814 μM/min and >4993 μM/min) had an increased risk of nonrelapse mortality (subdistribution HR, 3.32; 95% CI, 1.46 to 7.54; P = .004), as well as worse disease-free survival (HR, 1.81; 95% CI, 1.09 to 2.99; P = .021) and overall survival (HR, 1.94; 95% CI, 1.12 to 3.37; P = .018). Bu exposures between 4440 and 4993 μM/min were accompanied by the lowest risk of both nonrelapse mortality and acute GVHD
Meningeal dissemination in primary CNS lymphoma: prospective evaluation of 282 patients
BACKGROUND: The impact of meningeal dissemination in primary CNS lymphoma (PCNSL) is debated, and the reported frequency varies. We prospectively evaluated the diagnostic value of PCR in comparison with CSF cytomorphology and MRI for diagnosing meningeal dissemination in PCNSL. METHODS: We evaluated 282 patients from a multicenter therapy study for PCNSL for the presence of meningeal dissemination: 205 with CSF cytomorphology, 171 with PCR of the rearranged immunoglobulin heavy-chain genes in CSF, and 217 with cranial MRI. RESULTS: Meningeal dissemination was found in 33 of 205 patients (16%) by cytomorphology, in 19 of 171 (11%) patients evaluated by PCR, and in 8 of 217 patients (4%) by MRI. Considering either of these methods, the relative frequency of meningeal dissemination was 17.4% (49 of 282 patients). PCR was monoclonal in 6 of 19 (32%) samples with positive cytomorphology, 1 of 13 samples (8%) with suspicious cytology, and in 10 of 105 (10%) cytologically negative samples. In 11 samples with positive and 12 with suspicious cytology, PCR showed only a polyclonal pattern. The probability of meningeal dissemination detection was higher in cases with CSF pleocytosis (>5/microL) with an OR of 2.48 (95% CI 1.15-5.34, p = 0.018). CSF protein had no predictive value for meningeal dissemination detection. CONCLUSIONS: We found a low rate of meningeal dissemination in primary CNS lymphoma in this large prospective study. The rate of discordant PCR and cytomorphologic results was high. Thus, the methods should be regarded as complementary. CSF pleocytosis had predictive value for meningeal dissemination detection
Effect of conditioning regimen intensity on CMV infection in allogeneic hematopoietic cell transplantation.
Nonmyeloablative conditioning is less toxic and results in initial establishment of mixed hematopoietic T cell chimerism for up to half a year with prolonged presence of host T cell immunity. In this study, we examined whether this translates into differences in the risks and/or severity of cytomegalovirus (CMV) infection and disease. We analyzed data from 537 nonmyeloablative (NM-HCT) and contemporaneous 2489 myeloablative hematopoietic cell transplant (M-HCT) recipients. In CMV seropositive recipients, no difference in the overall hazards of CMV infection at any level (adjusted hazard ratio [adj. HR] 0.9, 95% confidence interval [95% CI]: 0.7-1.0, P = .14) was noted; however, NM-HCT was associated with a lower risk of high-grade CMV infection (adj. HR 0.7, 95% CI: 0.5-0.9, P = .02). CMV disease rates were similar between the groups during the first 100 days after HCT, but NM-HCT recipients had an increased risk of late CMV disease (adj. HR 2.0, 95% CI 1.2-3.4). The increased risk of late CMV disease after NM-HCT was pronounced during the earlier years of the study period, but not detectable in more recent years. Contrary to earlier reports, survival following CMV disease was not reduced after NM-HCT when compared to M-HCT recipients. These results suggest that residual host cells after NM-HCT reduce progression to higher CMV viral load in NM-HCT recipients; however, this effect does not appear to protect against serious complications of CMV. Therefore, CMV prevention strategies in NM-HCT recipients should be similar to those used in M-HCT recipients
Effects of Recombinant Human Interleukin 7 on T-Cell Recovery and Thymic Output in HIV-Infected Patients Receiving Antiretroviral Therapy: Results of a Phase I/IIa Randomized, Placebo-Controlled, Multicenter Study
Interleukin 7 induces a well-tolerated, dose-dependent, and sustained increase of CD4 T cells in human immunodeficiency virus-infected individuals treated with antiretroviral therapy, through an expansion of peripheral T cells that do not express activation markers, and increases thymic output in some patients
IFI16 and cGAS cooperate in the activation of STING during DNA sensing in human keratinocytes
Many human cells can sense the presence of exogenous DNA during infection though the cytosolic DNA receptor cyclic GMP-AMP synthase (cGAS), which produces the second messenger cyclic GMP-AMP (cGAMP). Other putative DNA receptors have been described, but whether their functions are redundant, tissue-specific or integrated in the cGAS-cGAMP pathway is unclear. Here we show that interferon-γ inducible protein 16 (IFI16) cooperates with cGAS during DNA sensing in human keratinocytes, as both cGAS and IFI16 are required for the full activation of an innate immune response to exogenous DNA and DNA viruses. IFI16 is also required for the cGAMP-induced activation of STING, and interacts with STING to promote STING phosphorylation and translocation. We propose that the two DNA sensors IFI16 and cGAS cooperate to prevent the spurious activation of the type I interferon response
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