Developing Integrated Approaches for Testing and Assessment (IATAs) in order to support nanomaterial safety.

Due to the unique characteristics of nanomaterials (NM) there has been an increase in their use in nanomedicines and innovative medical devices (MD). Although large numbers of NMs have now been developed, comprehensive safety investigations are still lacking. Current gaps in understanding the potential mechanisms of NM-induced toxicity can make it challenging to determine the safety testing necessary to support inclusion of NMs in MD applications. This article provides guidance for implementation of pre-clinical tailored safety assessment strategies with the aim to increase the translation of NMs from bench development to clinical use. Integrated Approaches to Testing and Assessment (IATAs) are a key tool in developing these strategies. IATAs follow an iterative approach to answer a defined question in a specific regulatory context to guide the gathering of relevant information for safety assessment, including existing experimental data, integrated with in silico model predictions where available and appropriate, and/or experimental procedures and protocols for generating new data to fill gaps. This allows NM developers to work toward current guidelines and regulations, while taking NM specific considerations into account. Here, an example IATA for NMs with potential for direct blood contact was developed for the assessment of haemocompatibility. This example IATA brings together the current guidelines for NM safety assessment within a framework that can be used to guide information and data gathering for the safety assessment of intravenously injected NMs. Additionally, the decision framework underpinning this IATA has the potential to be adapted to other testing needs and regulatory contexts.

Estudo multicêntrico de grupos paralelos, randomizado, cego para o investigador, para avaliar a eficácia, segurança e tolerabilidade do racecadotril versus Saccharomyces boulardii no tratamento da diarréia aguda em adultos / A multicentric, randomised, investigator-blind, parallel group study to assess the eficacy, safety and tolerability of Racecadotril versus Saccharomyces boulardii no tratamento da diarréia aguda em adultos

No presente estudo randomizado, paralelo, cego para o investigador, comparamos a eficácia do inibidor da encefalinase racecadotril ao Saccharomyces boulardii em 336 pacientes adultos ambulatoriais avaliáveis com diarréia aguda. Foram incluídos 175 pacientes avaliáveis no grupo com racecadotril e 161 pacientes avaliáveis foram incluidos no grupo com Saccharomyces boulardii. A duraçäo mädia da diarréia foi significativamente mais curta após o tratamento com racecadotril em comparaçäo com Saccharomyces boulardii. O tempo de recuperaçäo também foi mais curto com racecadotril em comparaçäo com S. boulardii, independente da gravidade da diarréia. Em casos brandos foi observada uma diferença de 24 horas entrte o tempo de recuperaçäo para racecadotril e S. boulardii e em casos graves a diferença entre os grupos foi de 17 horas. Além disso, a probabilidade de cura com racecadotril após dois dias de tratamento foi duas vezes maior e significante em comparaçäo ao Saccharomyces boulardii. Após três dias de tratamento, mais de dois terços dos pacientes em uso de racecadotril apresentaram recuperaçäo completa ao passo que quase metade dos pacientes com Saccharomyces boulardii näo haviam se recuperado. Em casos mais graves, a probabilidade de cura no dia 2 do tratamento com racecadotril foi três a quatro vezes maior em comparaçäo ao S. boulardii. Tanto racecadotril quanto Saccharomyces boulardii apresentaram um bom perfil de segurança.(au)

The recovery of populations of dogwhelks suffering from imposex in the Firth of Forth 1987-1997/98.

The impact of tributyltin (TBT) contamination on dogwhelk (Nucella lapillus) populations was assessed at 33 sites in the Firth of Forth, UK, during spring 1997 and summer 1998. The sex ratio of the animals; the ratio of juveniles to adults; the degree of imposex, as determined by the relative penis size index (RPSI); and the total tin concentration in a sample of dogwhelk tissue were used as measurements of TBT impact on dogwhelk populations. These data were compared with data from a similar survey carried out at the same sites in the Firth of Forth in 1987 (Bailey, S.K., Davies, I.M., 1988. Tributyltin contamination in the Firth of Forth (1975-1987). Science of the Total Environment 76, 185-192.) before restrictions were introduced on the use of TBT. The results demonstrate a general recovery in dogwhelk populations from the impact of TBT at the majority of the sites studied, although at six of the sites, the RPSI value remains high enough to suggest breeding problems in the population. It is suggested that large vessels are responsible for localised cases of imposex within the Firth of Forth.

Overexpressed full-length human BCL2 extends the survival of baculovirus-infected Sf9 insect cells.

Full-length and truncated human BCL2 lacking the entire C-terminal hydrophobic domain have been overexpressed in Spodoptera frugiperda insect cells with the baculovirus expression system. Immunoblot analysis with BCL2-specific antibodies revealed that both full-length and truncated BCL2 are expressed as multiple immunoreactive species, suggesting posttranslational modifications. The expression of the full-length but not the truncated BCL2 extended the survival of baculovirus-infected cells by preventing virus-induced DNA cleavage. This result is consistent with the reported protective effect of BCL2 against apoptosis in mammalian lymphocytes and suggests a conserved function in evolution. Subcellular fractionation and indirect immunofluorescence studies in intact cells demonstrated that the recombinant full-length and truncated BCL2 proteins were expressed predominantly as nuclear membrane-associated proteins. These results imply that BCL2 must utilize hydrophobic domains other than the deleted domain for its association with the subcellular membranes. Metabolic labeling of insect cells expressing the full-length and the truncated form of BCL2 with 32P(i) demonstrated that BCL2 is a phosphoprotein.

Involvement of BCL-2 in glucocorticoid-induced apoptosis of human pre-B-leukemias.

To determine the role of BCL-2 in the glucocorticoid-induced apoptosis of lymphocytes, we analyzed the effect of glucocorticoid on two human pre-B-cell lines which express different levels of BCL-2. Glucocorticoid treatment of the 380 cell line which expresses high levels of BCL-2 resulted in inhibition of cellular proliferation without induction of apoptosis. On the other hand, glucocorticoid treatment of the 697 cell line which expresses lower levels of the BCL-2 resulted in both inhibition of cellular proliferation and apoptosis with characteristic internucleosomal DNA cleavage. The glucocorticoid-induced inhibition of cellular proliferation in both cell lines was also associated with repression of the c-myc mRNA expression. Taken together, our data suggest that BCL-2 blocks the glucocorticoid-induced apoptosis of the 380 pre-B-lymphocytes by extending their survival when the level of c-myc expression is repressed. Also by repressing the expression of c-myc, glucocorticoid causes apoptosis of the 697 pre-B-lymphocytes in the absence of high level of BCL-2 expression.