Optimizing lyophilization primary Drying: A vaccine case study with experimental and modeling techniques.

In this study, we present the lyophilization process development efforts for a vaccine formulation aimed at optimizing the primary drying time (hence, the total cycle length) through comprehensive evaluation of its thermal characteristics, temperature profile, and critical quality attributes (CQAs). Differential scanning calorimetry (DSC) and freeze-drying microscopy (FDM) were used to experimentally determine the product-critical temperatures, viz., the glass transition temperature (Tg') and the collapse temperature (Tc). Initial lyophilization studies indicated that the conventional approach of targeting product temperature (Tp) below the Tc (determined from FDM) resulted in long and sub-optimal drying times. Interestingly, aggressive drying conditions where the product temperature reached the total collapse temperature did not result in macroscopic collapse but, instead, reduced the drying time by ∼ 45 % while maintaining product quality requirements. This observation suggests the need for a more reliable measurement of the macroscopic collapse temperature for product in vials. The temperature profiles from different lyophilization runs showed a drop in product temperature following the primary drying ramp, of which the magnitude was correlated to the degree of macroscopic collapse. The batch-average product resistance, Rp, determined using the manometric temperature measurement (MTM), decreased with increasing dried layer thickness for aggressive primary drying conditions. A quantitative analysis of the product temperature and resistance profiles combined with qualitative assessment of cake appearance attributes was used to determine a more representative macro-collapse temperature, Tcm, for this vaccine product. A primary drying design space was generated using first principles modeling of heat and mass transfer to enable selection of optimum process parameters and reduce the number of exploratory lyophilization runs. Overall, the study highlights the importance of accurate determination of macroscopic collapse in vials, pursuing aggressive drying based on individual product characteristics, and leveraging experimental and modeling techniques for process optimization.

Thrice weekly azacitidine does not improve hematological responses in lower-risk myelodysplastic syndromes: a study of the Hoosier Oncology Group.

Prolonged administration of methyl transferase inhibitors may increase response rates in myelodysplastic syndromes (MDS). Fourteen MDS patients with anemia and less than 10% marrow blasts received azacitidine 50 mg/m(2) thrice weekly for 2 weeks every 4 weeks; 7 also received weekly erythropoietin. The response rate of 43% did not improve the rates reported with other azacitidine administration schedules, so the study was closed. A decreased apoptosis of primitive erythroid progenitors and increased expression of BclX(L) was observed with treatment in responding patients compared to non-responders. Azacitidine may modulate BclX(L) and improve erythropoiesis through reduction of apoptosis in primitive erythroid progenitor population in MDS.

Cadherin-11 controls otolith assembly: evidence for extracellular cadherin activity.

Cadherin-11/Cdh11 is expressed through early development and strongly during inner ear development (otic placode and vesicle). Here we show that antisense knockdown of Cdh11 during early zebrafish development interferes with otolith formation. Immunofluorescence labeling showed that Cdh11 expression was concentrated on and within the otolith. Cdh11 was faintly detected at the lateral surface (sites of cell-cell contact) of otic epithelial cells and in the cytoplasm. Strongly labeled Cdh11 containing puncta were detected within the otolymph (the fluid within the otic vesicle) and associated with the otolith surface. BODIPY-ceramine-labeled vesicular structures detected in the otolymph were larger and more numerous in Cdh11 knockdown embryos. We present evidence supporting a working model that vesicular structures containing Cdh11 (perhaps containing biomineralization components) are exported from the otic epithelium into the otolymph, adhere to one another and to the surface of the growing otolith, facilitating otolith growth.

Variáveis preditoras de evasão em dois cursos a distância

A análise da literatura sobre educação a distância evidenciou altas taxas de evasão em cursos realizados nesta modalidade, escassez de estudos investigando este fenômeno, bem como a necessidade de modelos que investiguem variáveis preditoras de evasão. O presente trabalho é composto por três estudos. O primeiro estudo objetiva construir e validar a Escala de Comportamentos e Atitudes do Aluno em Relação a Cursos a Distância. O objetivo do segundo estudo é revalidar a Escala de Valor Instrumental do Treinamento, no âmbito da Educação a Distância. O terceiro estudo objetiva analisar o relacionamento entre características da clientela (idade, gênero, participação anterior em curso a distância, pagamento do curso pelo aluno e valor instrumental do treinamento), características do curso (semipresencial ou totalmente a distância) e comportamentos e atitudes do aluno em relação a cursos a distância com a variável critério evasão. A coleta de dados foi realizada totalmente via web. Os instrumentos, hospedados em página específica, foram aplicados em diferentes turmas dos cursos de Mediação e Arbitragem e Formação de Consultores, de acordo com banco de dados fornecido pela empresa pesquisada, no período de fevereiro a abril de 2006. Em um primeiro momento, foram enviados 1.494 e-mails aos alunos, sendo 615 evadidos e 879 concluintes. Foram recebidos respondidos 517 questionários de Comportamentos e Atitudes do Aluno em Relação a Cursos a Distância (taxa de retorno de 34,6 por cento) e 483 questionários de Valor Instrumental do Treinamento (taxa de retorno de 32,3 por cento). No Estudo 1 e 2, as respostas válidas aos questionários foram submetidas a análises exploratórias, extração dos fatores principais (PAF e tratamento listwise para casos omissos) e análises de confiabilidade (Alpha de Cronbach). No Estudo 2 foram realizadas análises não paramétricas e análises de regressão logística, visto o caráter dicotômico da variável critério. Como resultado do Estudo 1 foi validada estatisticamente a escala de Comportamentos e Atitudes do Aluno em Relação a Cursos a Distância, com estrutura bifatorial. O Fator 1 (a = 0,80), denominado Fatores Intrínsecos e Extrínsecos Positivos Relacionados a Cursos a Distância, é composto por treze itens com cargas fatoriais variando entre 0,72 e 0,39. Esse fator refere-se a comportamentos e atitudes do treinando, bem como condições relacionadas ao contexto...(AU)

Shp-2 heterozygous hematopoietic stem cells have deficient repopulating ability due to diminished self-renewal.

OBJECTIVE: Improved understanding of hematopoietic stem cell (HSC) differentiation, proliferation, and self-renewal is sought to develop improved stem cell-based therapies as well as to define novel therapies for stem cell-based diseases such as leukemia. Shp-2 is a widely expressed nonreceptor protein tyrosine phosphatase that participates early in hematopoietic development. The following study was performed to examine the role of Shp-2 in HSC function. METHODS: Bone marrow low-density mononuclear cells were isolated from WT and Shp-2(+/-) littermate controls and utilized in competitive repopulation studies, homing analysis, cell-cycle analysis, and serial transplantation studies. RESULTS: Haploinsufficiency of Shp-2 causes a threefold reduction in HSC repopulating units following transplantation into lethally irradiated recipients. Homing of Shp-2(+/-) and WT cells to the bone marrow and spleen compartments was equal. Cell-cycle analysis studies revealed that the Shp-2(+/-) lin(-)Sca-1(+)c-kit(+) cells are less quiescent than WT cells, providing a potential etiology for the observed reduced engraftment of the Shp-2(+/-) cells. Consistently, in serial transplantation studies, we observed a significant reduction of Shp-2(+/-) self-renewal compared to that of WT cells. CONCLUSION: These data demonstrate that Shp-2 is required for the physiologic homeostasis of the HSC compartment and potentially provide insight into how oncogenic Shp-2 may contribute to the pathogenesis of myeloproliferative disorders and leukemias.