Biorefining of wheat straw:accounting for the distribution of mineral elements in pretreated biomass by an extended pretreatment–severity equation

BACKGROUND: Mineral elements present in lignocellulosic biomass feedstocks may accumulate in biorefinery process streams and cause technological problems, or alternatively can be reaped for value addition. A better understanding of the distribution of minerals in biomass in response to pretreatment factors is therefore important in relation to development of new biorefinery processes. The objective of the present study was to examine the levels of mineral elements in pretreated wheat straw in response to systematic variations in the hydrothermal pretreatment parameters (pH, temperature, and treatment time), and to assess whether it is possible to model mineral levels in the pretreated fiber fraction. RESULTS: Principal component analysis of the wheat straw biomass constituents, including mineral elements, showed that the recovered levels of wheat straw constituents after different hydrothermal pretreatments could be divided into two groups: 1) Phosphorus, magnesium, potassium, manganese, zinc, and calcium correlated with xylose and arabinose (that is, hemicellulose), and levels of these constituents present in the fiber fraction after pretreatment varied depending on the pretreatment-severity; and 2) Silicon, iron, copper, aluminum correlated with lignin and cellulose levels, but the levels of these constituents showed no severity-dependent trends. For the first group, an expanded pretreatment-severity equation, containing a specific factor for each constituent, accounting for variability due to pretreatment pH, was developed. Using this equation, the mineral levels could be predicted with R(2) > 0.75; for some with R(2) up to 0.96. CONCLUSION: Pretreatment conditions, especially pH, significantly influenced the levels of phosphorus, magnesium, potassium, manganese, zinc, and calcium in the resulting fiber fractions. A new expanded pretreatment-severity equation is proposed to model and predict mineral composition in pretreated wheat straw biomass

Transplantation of ex vivo expanded cord blood cells using the copper chelator tetraethylenepentamine: a phase I/II clinical trial

The copper chelator tetraethylenepentamine (TEPA; StemEx) was shown to attenuate the differentiation of ex vivo cultured hematopoietic cells resulting in preferential expansion of early progenitors. A phase I/II trial was performed to test the feasibility and safety of transplantation of CD133+ cord blood (CB) hematopoietic progenitors cultured in media containing stem cell factor, FLT-3 ligand, interleukin-6, thrombopoietin and TEPA. Ten patients with advanced hematological malignancies were transplanted with a CB unit originally frozen in two fractions. The smaller fraction was cultured ex vivo for 21 days and transplanted 24 h after infusion of the larger unmanipulated fraction. All but two units contained <2×10 7 total nucleated cells (TNCs) per kilogram pre-expansion. All donor–recipient pairs were mismatched for one or two HLA loci. Nine patients were beyond first remission; median age and weight were 21 years and 68.5 kg. The average TNCs fold expansion was 219 (range, 2–620). Mean increase of CD34+ cell count was 6 (over the CD34+ cell content in the entire unit). Despite the low TNCs per kilogram infused (median = 1.8×10 7 /kg), nine patients engrafted. Median time to neutrophil and platelet engraftment was 30 (range, 16–46) and 48 (range, 35–105) days. There were no cases of grades 3–4 acute graft-versus-host disease (GVHD) and 100-day survival was 90%. This strategy is feasible

Candados y contrapesos : la protección de los programas, políticas y derechos sociales en México y América Latina

Candados y contrapesos es una obra novedosa por las distintas perspectivas analíticas que abordan destacados especialistas, investigadores y académicos sobre un tema que ha sido el centro del debate en las políticas públicas y se ha convertido en una creciente preocupación en la opinión pública: el uso político de los recursos públicos, en particular los dirigidos al desarrollo social. Si bien existen prácticas, normas y políticas que tienden a proteger este uso en los países latinoamericanos, lo cierto es que aún no existe una conceptualización rigurosa y exhaustiva sobre este hecho, de ahí que el propósito central de este libro sea ofrecer un marco conceptual y analítico del fenómeno del uso político–clientilista de las políticas, los programas y los gastos sociales en —y fuera de— los contextos electorales. Además, esta obra es un valioso repertorio de propuestas, recomendaciones concretas de política pública y experiencias internacionales, dirigida a funcionarios públicos, directores de organizaciones sociales, especialistas e investigadores

Transplantation of Cord Blood Expanded Ex Vivo with Copper Chelator

Abstract Cord blood (CB) is used to restore hematopoiesis in transplant patients lacking marrow donors. CB is associated with higher rates of delayed/failed engraftment. Peled et al developed an expansion technology using the copper chelator tetraethylenepentamine (TEPA), which enhanced the expansion of primitive CB populations when combined with early acting cytokines. A phase I clinical trial employing this technology was initiated. 10 patients with high-risk, heavily pre-treated hematologic malignancies (AML-2, ALL-5, HD-2, and NHL-1) have been enrolled with CB units that were cryopreserved in 2 fractions [20:80% (n=2), 40:60% (n=5) or 50:50% (n=3)]. 21days prior to infusion, AC133+ cells were isolated from the smaller (if unequal) or 50% CB fractions using the CliniMACS device and cultured for 21 days in media containing 10% FBS and SCF, FLT-3, IL6, TPO plus the copper chelator TEPA (Gamida). Patients then received myeloablative therapy with ATG and either fludara and busulfan (AML), or fludara, melphalan, thiotepa (ALL, HD, NHL) with infusion of the unmanipulated CB fraction on day 0, and the expanded fraction on day +1. GVHD prophylaxis was methotrex 5 mg/m2 days 2, 4,7, and tacrolimus for 6 months. The median age was 21 (range 7–51) and weight 69 (range 31–156) kg. The CB units were matched at 4/6 (n=8) or 5/6 (n=2) HLA antigens. The pre-thaw total nucleated cell (TNC) dose of the CB units was a median of 2.5x107/kg with post-thaw TNC of 2.4 x107/kg. Following AC133-selection, the manipulated CB fractions were a median of 73 (range 38–95)% AC133+ with a median of 0.650 (range 0.16–2.7) x106 TNCs, which were placed in culture. After 21 days of culture the expanded fraction had 69 (range 2–1638) x106 TNCs representing a 207 (range 2–616) fold TNC expansion. Patients received a total (expanded plus unmanipulated) median of 1.8 (range 1.1–6.1) x107 TNC/kg and 1.6x105 (range 0.4–49.9) CD34+ cells/kg. Two patients have CB cultures in progress. Of the 8 patients transplanted, 1 had autologous recovery with relapse of AML on day 30 and death. Of the remaining patients, 7 were evaluable for neutrophil engraftment and 4 of them for platelet engraftment (2 too early for platelet evaluation and 1 early death). The median time to engraftment was 27 days for neutrophils (range 16–46) and 48 days for platelets (range 27–96). Preliminary analysis suggest a correlation between a shorter time to neutrophil engraftment and total TNC/kg infused (p=0.02), and a trend for CD34+ cells/kg infused (p=0.09). Three patients have developed grade ≤2 acute skin GVHD and one had chronic extensive GVHD of the skin and GI tract; all resolved with steroids. One patient (without GVHD) died of a systemic viral infection on day 56, despite adequate neutrophil recovery (not platelets). All of the remaining patients are all alive and free of malignancy at a median follow-up of 4 (range 1–16) months. Conclusion: There was no toxicity associated with infusion of the TEPA-expanded CB cells. Additional data is necessary to determine the efficacy of this approach. Future directions include the expansion of the entire CB unit and removal of methotrex from the GVHD regimen to improve time to neutrophil engraftment, as well as comprehensive assessment of immune reconstitution