Pr(H3BNMe2BH3)3 and Pr(thd)3 as Volatile Carriers for Actinium-225. Deposition of Actinium-Doped Praseodymium Boride Thin Films for Potential Use in Brachytherapy.

Here we show that the praseodymium N,N-dimethylaminodiboranate complex Pr(H3BNMe2BH3)3 and the 2,2,6,6-tetramethylheptane-3,5-dionate complex Pr(thd)3 can serve as volatile carriers for 225Ac. The actinium coordination complexes Ac(H3BNMe2BH3)3 and Ac(thd)3 are the likely species subliming with the carrier material. A sample of 225Ac-doped Pr(H3BNMe2BH3)3 was used to deposit amorphous 225Ac-doped praseodymium boride films on glass and Si(100) at 300 °C. The α emission spectra of the refractory films are well-resolved, suggesting that they could be used as radioactive implants for brachytherapy and related treatments.

Selective separation of radium and actinium from bulk thorium target material on strong acid cation exchange resin from sulfate media.

This work presents a complete scheme for the selective separation of actinium and radium isotopes from bulk 232Th target material, in a process that may be applied in a separation scheme for the production of 225Ac by proton spallation on thorium. Thorium metal is dissolved in sulfuric acid with small amounts of HF. Actinium and radium are retained on cation exchange resin from the sulfate medium, while neutral and anionic thorium sulfate complexes are rejected. Following rinsing steps to remove residual thorium, actinium and radium are recovered from the cation exchange resin using 5 M HNO3. Further separations of actinium via extraction chromatography with UTEVA and DGA resins yield actinium in >92% yield, while providing additional decontamination from thorium and other spallation byproducts. The radium fraction can be further processed following ingrowth of 225Ac from 225Ra to produce additional 225Ac free from any potential 227Ac impurity.

Causes of death among cancer patients.

Background: The purpose of our study was to characterize the causes of death among cancer patients as a function of objectives: (i) calendar year, (ii) patient age, and (iii) time after diagnosis. Patients and methods: US death certificate data in Surveillance, Epidemiology, and End Results Stat 8.2.1 were used to categorize cancer patient death as being due to index-cancer, nonindex-cancer, and noncancer cause from 1973 to 2012. In addition, data were characterized with standardized mortality ratios (SMRs), which provide the relative risk of death compared with all persons. Results: The greatest relative decrease in index-cancer death (generally from > 60% to < 30%) was among those with cancers of the testis, kidney, bladder, endometrium, breast, cervix, prostate, ovary, anus, colorectum, melanoma, and lymphoma. Index-cancer deaths were stable (typically >40%) among patients with cancers of the liver, pancreas, esophagus, and lung, and brain. Noncancer causes of death were highest in patients with cancers of the colorectum, bladder, kidney, endometrium, breast, prostate, testis; >40% of deaths from heart disease. The highest SMRs were from nonbacterial infections, particularly among <50-year olds (e.g. SMR >1,000 for lymphomas, P < 0.001). The highest SMRs were typically within the first year after cancer diagnosis (SMRs 10-10,000, P < 0.001). Prostate cancer patients had increasing SMRs from Alzheimer's disease, as did testicular patients from suicide. Conclusion: The risk of death from index- and nonindex-cancers varies widely among primary sites. Risk of noncancer deaths now surpasses that of cancer deaths, particularly for young patients in the year after diagnosis.

Is it necessary to perform week three dosimetric analysis in low-dose-rate brachytherapy for prostate cancer when day 0 dosimetry is done? A quality assurance assessment.

PURPOSE: To determine whether computed tomography/magnetic resonance imaging-based day 0 (d0) dosimetry is a meaningful predictor of day 21 (d21) dosimetry in low-dose-rate brachytherapy for localized prostate cancer. METHODS AND MATERIALS: The study population consisted of 277 men with localized (T1-2 N0 M0), low-/intermediate-risk prostate cancer treated with low-dose-rate brachytherapy. Computed tomography/magnetic resonance imaging fusion was used for postimplant dosimetry at d0 and d21. Logistic regression was used to construct receiver operating characteristic curves for achieving each constraint at d21, based on d0 D90 and V100, and Youden's index was used to evaluate cutpoints. Freedom from biochemical failure (FBCF) was estimated with the Kaplan-Meier method. RESULTS: The median d0 D90 increased from 133 to 150 Gy at d21, and median d0 V100 increased from 87% to 91%. For achieving the D90 constraint at d21, the optimal cut-point for d0 D90 was 135 Gy, with 84% of these patients maintaining a d21 D90 > 145 Gy. For achieving the D90 constraint at d21, the optimal cut-point for d0 V100 was 87%, with 83% of these patients maintained a d21 V100 > 90%. There was no improvement in FBCF in patients with a d0 D90 > 135 Gy or D90 > 145 Gy. Similarly, there was no improvement in FBCF in patients with a d0 V100 > 87% or V100 > 90%. CONCLUSIONS: Meeting dosimetric constraints on d0 does not obviate d21 dosimetric analysis. Constraints used for dose prescriptions on d0 are not the ideal predictors of d21 dosimetry.

Colistin is relatively safe in hematological malignancies and hematopoietic stem cell transplantation patients.

PURPOSE: Colistin is increasingly used as the last-resort treatment option against infections caused by multidrug-resistant (MDR) Gram-negative pathogens, but its nephrotoxicity is of concern, especially in severely ill patients. The aim of this study was to analyze the toxicity of colistin therapy in adults and children with hematological malignancies (HM) and hematopoietic stem cell transplantation (HSCT) recipients. METHODS: Data on HSCT recipients and HM patients, treated with intravenous colistin (2.5-5 mg/kg/day in children and 3-6 million international units (IU) in adults, adjusted to renal function) during the period 2008-2011 in our center, were retrospectively collected and analyzed. Nephrotoxicity was defined according to the RIFLE criteria (Risk, Injury, Failure, Loss, and End-stage kidney disease). RESULTS: Twenty-nine children and adults received 38 courses of intravenous colistin (2.5-5 mg/kg/day in children and 3-6 × 10(6) IU in adults, adjusted to renal function) [allogeneic HSCT (22 courses) and HM (16 courses)] for 3-28 days (median 10 days) for empirical therapy for nosocomial clinical sepsis (28) or local infection (6), and bacteremia with MDR Gram-negative rods (4). Nephrotoxicity was observed at the end of 4 (10.5%) courses. In 32 (84%) courses, nephrotoxic medications were concomitantly administered. Two patients had convulsions, probably unrelated to colistin. Seven patients (18%) died while on colistin therapy. No death was attributed to an adverse effect of colistin. CONCLUSIONS: Treatment with intravenous colistin, with dosage adjusted to renal function, was relatively safe for HM/HSCT patients, even with concomitantly administered nephrotoxic medications. Concern about nephrotoxicity should not justify a delay in initiating empirical colistin treatment in situations where infection with MDR Gram-negative rods is likely.

Frequent mutations in SH2D1A (XLP) in males presenting with high-grade mature B-cell neoplasms.

X-linked lymphoproliferative syndrome (XLP) is caused by mutations in SH2D1A, and is associated with overwhelming infectious mononucleosis, aplastic anemia, hypogammaglobulinemia, and B-cell lymphomas. However, the frequency of SH2D1A mutations in males who present with B NHL is unknown. Five cases of XLP were diagnosed among 158 males presenting with B NHL (approximately 3.2%). Four of the patients had two episodes of B NHL and one had a single episode of B NHL followed by aggressive infectious mononucleosis. Prospective screening for XLP in males with B-cell lymphoma at the time of initial diagnosis should be considered.

A phase I/II study of CY and topotecan in patients with high-risk malignancies undergoing autologous hematopoietic cell transplantation: the St Jude long-term follow-up.

Fifty-eight consecutive children with high-risk malignancies were treated with CY, and targeted topotecan followed by autologous hematopoietic cell transplantation (AHCT) in a phase I/II Institutional Review Board-approved study. Twelve participants enrolled in phase I; 5 received dose level 1 of topotecan 3 mg/m(2) per day, with subsequent doses targeted to total systemic exposure of 100±20 ng h/mL and CY 750 mg/m(2) per day. Seven participants received dose level 2. CY dose escalation to 1 g/m(2) per day was considered excessively toxic; one died from irreversible veno-occlusive disease and two experienced reversible hepatotoxicity. These adverse events halted further dose escalation. A total of 46 participants were enrolled in phase II; results are on the 51 participants who received therapy at dose level 1, the maximum tolerated dose. Diagnoses included neuroblastoma (26), sarcoma (9), lymphoma (8), brain tumors (5), Wilms (2) and retinoblastoma (1). Twenty participants (39.3%) were in CR1 at enrollment; median age was 5.1 years. Most common non-hematological grade III-IV toxicity was gastrointestinal (n=37). Neutrophil and platelet engraftment occurred at a median of 15 and 24 days, respectively. Twenty-six (51%) participants remain alive at a median of 6.4 years after AHCT. CY 3.75 g/m(2), and targeted topotecan followed by AHCT are feasible and produce acceptable toxicity in children with high-risk malignancies.

Effects of activating NK cell receptor expression and NK cell reconstitution on the outcomes of unrelated donor hematopoietic cell transplantation for hematologic malignancies.

Inhibitory NK cell receptors are recognized as important determinants of NK cell activity in hematopoietic cell transplantation (HCT). The role of activating receptors and their acquisition after HCT is less certain. Therefore, we comprehensively evaluated both inhibitory and activating receptors in 59 patients receiving unrelated donor HCT. NK cell numbers normalized quickly relative to B and T cells; however, the expression of both inhibitory and activating isoforms of killer immunoglobulin-like receptors (KIRs) was delayed. Most NK cells expressed an immature phenotype during the first 6 months post-HCT; however, we found high expression of activating NKp46 and NKp44 natural cytotoxicity receptors (NCRs), and cytotoxicity was preserved. Early reconstituting NK cells from unmanipulated grafts showed lower cytotoxicity than those from T-cell-depleted grafts. Differences in NK cell reconstitution had significant effects on clinical outcomes. Patients whose NK cells reconstituted earlier had better survival and lower relapse rates. The best survival group was recipients who possessed HLA-C2 but their donor lacked the cognate-activating KIR2DS1. Collectively, our data underscore the clinical relevance of reconstituting NK cells and their activating KIRs and NCRs. In addition to NK cell quantification and genotyping, comprehensive assessment of NK cell functions and phenotypes, including activating receptors, is essential.

Basic research and clinical applications of non-hematopoietic stem cells, 4-5 April 2008, Tubingen, Germany.

From 4 to 5 April 2008, international experts met for the second time in Tubingen, Germany, to present and discuss the latest proceedings in research on non-hematopoietic stem cells (NHSC). This report presents issues of basic research including characterization, isolation, good manufacturing practice (GMP)-like production and imaging as well as clinical applications focusing on the regenerative and immunomodulatory capacities of NHSC.

A novel approach for quantification of KIR expression in healthy donors and pediatric recipients of hematopoietic SCTs.

The killer cell Ig-like receptor (KIR) expression repertoire may offer valuable information for hematopoietic SCT (HSCT). We designed a quantitative KIR RNAtype assay and used it to determine KIR gene expression in healthy donors and patients before HSCT. The specificity of the assay was ensured by specific primers and by electrophoretic distinction of PCR products of unique length. In 87 healthy donors, the KIR repertoire was broadly distributed (32 categories of profiles). There was an overall trend toward inverse correlation of KIR expression level and donor age. Age affected mainly the activating KIR families. Leukemia patients showed lower KIR expression before transplantation than healthy donors. Stem cell mobilization caused a transient increase of KIR expression. We conclude that KIR expression differs quantitatively with age and primary disease and is transiently altered by stem cell recruitment and selection.

How do mesenchymal stromal cells exert their therapeutic benefit?

In recent years mesenchymal stromal cells (MSC) have emerged as a major new form of cell therapy. While the original perception was that MSC were stem/progenitor cells with the potential to contribute to the regeneration of tissue, more recent data suggest that the principal mechanism of MSC activity is through the release of soluble mediators that elicit the observed biologic response. Future studies are needed to identify more completely the spectrum of therapeutic applications and delineate better the associated molecular and cellular mechanisms.

A potential role for Dkk-1 in the pathogenesis of osteosarcoma predicts novel diagnostic and treatment strategies.

Canonical Wnt signalling is an osteoinductive signal that promotes bone repair through acceleration of osteogenic differentiation by progenitors. Dkk-1 is a secreted inhibitor of canonical Wnt signalling and thus inhibits osteogenesis. To examine a potential osteoinhibitory role of Dkk-1 in osteosarcoma (OS), we measured serum Dkk-1 in paediatric patients with OS (median age, 13.4 years) and found it to be significantly elevated. We also found that Dkk-1 was maximally expressed by the OS cells at the tumour periphery and in vitro, Dkk-1 and RANKL are coexpressed by rapidly proliferating OS cells. Both Dkk-1 and conditioned media from OS cells reduce osteogenesis by human mesenchymal cells and by immunodepletion of Dkk-1, or by adding a GSK3beta inhibitor, the effects of Dkk-1 were attenuated. In mice, we found that the expression of Dkk-1 from implanted tumours was similar to the human tumour biopsies in that human Dkk-1 was present in the serum of recipient animals. These data demonstrate that systemic levels of Dkk-1 are elevated in OS. Furthermore, the expression of Dkk-1 by the OS cells at the periphery of the tumour probably contributes to its expansion by inhibiting repair of the surrounding bone. These data demonstrate that Dkk-1 may serve as a prognostic or diagnostic marker for evaluation of OS and furthermore, immunodepletion of Dkk-1 or administration of GSK3beta inhibitors could represent an adjunct therapy for this disease.

Animal serum-free culture conditions for isolation and expansion of multipotent mesenchymal stromal cells from human BM.

BACKGROUND: Multipotent mesenchymal stromal cells (MSC) have become important tools in regenerative and transplantation medicine. Rapidly increasing numbers of patients are receiving in vitro-expanded MSC. Culture conditions typically include FSC because human serum does not fully support growth of human MSC in vitro (MSC(FCS)). Concerns regarding BSE, other infectious complications and host immune reactions have fueled investigation of alternative culture supplements. METHODS: As PDGF has long been identified as a growth factor for MSC, we tested media supplementation with platelet lysate for support of MSC proliferation. RESULTS: We found that primary cultures of BM-derived MSC can be established with animal serum-free media containing fresh frozen plasma and platelets (MSC(FFPP)). Moreover, MSC(FFPP) showed vigorous proliferation that was superior to classical culture conditions containing FCS. MSC(FFPP) morphology was equivalent to MSC(FCS), and MSC(FFPP) expressed CD73, CD90, CD105, CD106, CD146 and HLA-ABC while being negative for CD34, CD45 and surface HLA-DR, as expected. In addition to being phenotypically identical, MSC(FFPP) could efficiently differentiate into adipocytes and osteoblasts. In terms of immune regulatory properties, MSC(FFPP) were indistinguishable from MSC(FCS). Proliferation of PBMC induced by IL-2 in combination with OKT-3 or by PHA was inhibited in the presence of MSC(FFPP). DISCUSSION: Taken together, FCS can be replaced safely by FFPP in cultures of MSC for clinical purposes.

Clarification of the nomenclature for MSC: The International Society for Cellular Therapy position statement.

The plastic-adherent cells isolated from BM and other sources have come to be widely known as mesenchymal stem cells (MSC). However, the recognized biologic properties of the unfractionated population of cells do not seem to meet generally accepted criteria for stem cell activity, rendering the name scientifically inaccurate and potentially misleading to the lay public. Nonetheless, a bona fide MSC most certainly exists. To address this inconsistency between nomenclature and biologic properties, and to clarify the terminology, we suggest that the fibroblast-like plastic-adherent cells, regardless of the tissue from which they are isolated, be termed multipotent mesenchymal stromal cells, while the term mesenchymal stem cells is used only for cells that meet specified stem cell criteria. The widely recognized acronym, MSC, may be used for both cell populations, as is the current practice; thus, investigators must clearly define the more scientifically correct designation in their reports. The International Society for Cellular Therapy (ISCT) encourages the scientific community to adopt this uniform nomenclature in all written and oral communications.

Correction of a mineralization defect by overexpression of a wild-type cDNA for COL1A1 in marrow stromal cells (MSCs) from a patient with osteogenesis imperfecta: a strategy for rescuing mutations that produce dominant-negative protein defects.

Gene therapy for dominant-negative disorders presents a more difficult challenge than gene therapy for recessive disorders, since even partial replacement of a protein for a recessive disorder can reverse symptoms. Osteogenesis imperfecta (OI) has frequently served as a model disorder for dominant-negative defects of structural proteins. The disease is caused by mutations in type I collagen (COL1A1), the major structural component of bone, skin and other connective tissues. The severity of the phenotype is largely dependent on the ratio of normal to mutant type I procollagen synthesized by cells. Recently, attempts have been made to develop strategies for cell and gene therapies using the adult stem cells from bone marrow referred to as mesenchymal stem cells or marrow stromal cells (MSCs). In this study, we used MSCs from a patient with type III OI who was heterozygous for an IVS 41A+4C mutation in COL1A1. A hybrid genomic / cDNA construct of COL1A1 was transfected into the MSCs and the transfectants were expanded over a 200-fold. Transfected MSCs showed increased expression of the wild-type mRNA and protein. In vitro assays demonstrated that the transfected cells more efficiently differentiated into mineralizing cells. The results indicated that it is possible to overexpress COL1A1 cDNA in OI MSCs and thereby to correct partially the dominant-negative protein defect.

A method for the separation of beryllium from spectral interfering elements in inductively coupled plasma-atomic emission spectroscopic analysis.

A quick, simple and effective chromatographic method for the separation of beryllium from a wide range of elements is described. The elements selected comprise elements which can interfere with the determination of beryllium by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and elements which commonly occur in environmental and industrial sample matrices. Beryllium is separated from all possible ICP-AES spectral interfering elements using a single extraction chromatographic (EXC) cartridge containing an acidic chelating organophosphorus extractant, Dipex((R)), sorbed onto an inert polymeric substrate. The separation method has been evaluated using simulated samples generated using several different digestion methods currently employed in beryllium analyses performed in Department of Energy (DOE) facilities. Incorporating a guard cartridge containing either 2-ethyl-1-hexylphosphonic acid mono 2-ethyl-1-hexyl ester or bis(2,4,4-trimethylpentyl)phosphinic acid to selectively remove U(VI) allows the isolation of beryllium from samples containing over 100mg of uranium without changing the load, rinse or strip conditions of the method.