Wound-healing gene family expression differences between fetal and foreskin cells used for bioengineered skin substitutes.

For tissue engineering, several cell types and tissues have been proposed as starting material. Allogenic skin products available for therapeutic usage are mostly developed with cell culture and with foreskin tissue of young individuals. Fetal skin cells offer a valuable solution for effective and safe tissue engineering for wounds due to their rapid growth and simple cell culture. By selecting families of genes that have been reported to be implicated in wound repair and particularly for scarless fetal wound healing including transforming growth factor-beta (TGF-beta) superfamily, extracellular matrix, and nerve/angiogenesis growth factors, we have analyzed differences in their expression between fetal skin and foreskin cells, and the same passages. Of the five TGF-beta superfamily genes analyzed by real-time reverse transcription-polymerase chain reaction, three were found to be significantly different with sixfold up-regulated for TGF-beta2, and 3.8-fold for BMP-6 in fetal cells, whereas GDF-10 was 11.8-fold down-regulated. For nerve growth factors, midkine was 36-fold down-regulated in fetal cells, and pleiotrophin was 4.76-fold up-regulated. We propose that fetal cells present technical and therapeutic advantages compared to foreskin cells for effective cell-based therapy for wound management, and overall differences in gene expression could contribute to the degree of efficiency seen in clinical use with these cells.

Covalent cell surface functionalization of human fetal osteoblasts for tissue engineering.

The chemical functionalization of cell-surface proteins of human primary fetal bone cells with hydrophilic bioorthogonal intermediates was investigated. Toward this goal, chemical pathways were developed for click reaction-mediated coupling of alkyne derivatives with cellular azido-expressing proteins. The incorporation via a tetraethylene glycol linker of a dipeptide and a reporter biotin allowed the proof of concept for the introduction of cell-specific peptide ligands and to follow the reaction in living cells. Tuning the conditions of the click reaction resulted in chemical functionalization of living human fetal osteoblasts with excellent cell survival.

Cinética de fósforo com modelos matemáticos em ovinos adultos

O objetivo deste trabalho foi avaliar, por meio de modelos matemáticos, o metabolismo de fósforo (P) em ovinos adultos suplementados com teores crescentes de farinha de ossos calcinados com 0, 1, 2 e 3 g de P por animal por dia. Esses valores representaram diferentes tratamentos, adicionados à dieta basal com 225 g de concentrado e feno ad libitum. Foram utilizados 16 ovinos, Suffolk, com peso vivo de 38,2±4,35 kg e idade média de 18 meses, mantidos em gaiolas individuais. Após 21 dias, 7,4 MBq do radiofósforo (32P) foram injetados em cada ovino, e foram coletados sangue, fezes e urina por oito dias, a fim de determinar o fluxo de P entre três compartimentos: trato gastrintestinal, compartimento central (sangue) e tecidos (moles e ósseo). Houve relação linear positiva entre o P consumido e o P absorvido, excretado nas fezes, urina e retenção. A perda endógena fecal de P foi exponencial com o aumento de P da dieta. A elevação do teor de P da dieta interfere nas trocas do mineral para o trato gastrintestinal e urinário, o que indica que 0,82 g de P por dia são suficientes para mantença dessa categoria animal.

Hipertensión y edema pulmonar de altura. Rol de la disfunción endotelial y de la programación fetal [Pulmonary hypertension and lung edema at high altitude. Role of endothelial dysfunction and fetal programming].

High altitude constitutes an exciting natural laboratory for medical research. While initially, the aim of high-altitude research was to understand the adaptation of the organism to hypoxia and find treatments for altitude-related diseases, over the past decade or so, the scope of this research has broadened considerably. Two important observations led to the foundation for the broadening of the scientific scope of high-altitude research. First, high-altitude pulmonary edema (HAPE) represents a unique model which allows studying fundamental mechanisms of pulmonary hypertension and lung edema in humans. Secondly, the ambient hypoxia associated with high-altitude exposure facilitates the detection of pulmonary and systemic vascular dysfunction at an early stage. Here, we review studies that, by capitalizing on these observations, have led to the description of novel mechanisms underpinning lung edema and pulmonary hypertension and to the first direct demonstration of fetal programming of vascular dysfunction in humans.

Surface modification of biomaterials for conjugation with human fetal osteoblasts.

Surface functionalization of hydroxyapatite (HA) and beta-tricalcium phosphate (TCP) bioceramics with chemical ligands containing a pyrrogallol moiety was developed to improve the adhesion of bone cell precursors to the biomaterials. Fast and biocompatible copper-free click reaction with azido-modified human fetal osteoblasts resulted in improved cell binding to both HA and TCP bioceramics, opening the way for using this methodology in the preparation of cell-engineered bone implants.

Utilização de bactérias ácido-lácticas isoladas do trato intestinal de tilápia-do-nilo como probiótico

O objetivo deste trabalho foi isolar bactérias ácido-lácticas do intestino de tilápias-do-nilo, e avaliar seu potencial probiótico. Foram isoladas cepas de bactérias ácido-lácticas, e foi avaliada a inibição aos patógenos in vitro. As cepas com os melhores resultados foram identificadas e utilizadas no experimento de colonização do trato intestinal de tilápias-do-nilo, via suplementação na dieta, em delineamento inteiramente ao acaso, com três tratamentos e quatro repetições. Foram avaliados: o total de bactérias, as bactérias ácido-lácticas, Vibrio ssp. e Pseudomonas ssp. A cepa com melhor resultado foi utilizada na infecção experimental, em delineamento inteiramente ao acaso, em esquema fatorial 2x3: dieta suplementada com a cepa e dieta-controle; e os peixes não submetidos à injeção, peixes submetidos à injeção de solução salina e à injeção de Enterococcus durans, com três repetições. Foram avaliados os parâmetros hematológicos. As duas cepas identificadas foram: Lactobacillus plantarum e Lactobacillus brevis, que colonizaram o trato intestinal de tilápias, contudo L. plantarum teve menor número total de bactérias e de Pseudomonas ssp. Foi observado maior número total de eritrócitos, trombócitos, leucócitos, linfócitos, neutrófilos e monócitos, em peixes alimentados com L. plantarum e submetidos à injeção de E. durans. O L. plantarum tem efeito probiótico e melhora o sistema imune das tilápias.

Phenotypic and functional analysis of human fetal liver hematopoietic stem cells in culture.

Steady-state hematopoiesis and hematopoietic transplantation rely on the unique potential of stem cells to undergo both self-renewal and multilineage differentiation. Fetal liver (FL) represents a promising alternative source of hematopoietic stem cells (HSCs), but limited by the total cell number obtained in a typical harvest. We reported that human FL nonobese diabetic/severe combined immunodeficient (NOD/SCID) repopulating cells (SRCs) could be expanded under simple stroma-free culture conditions. Here, we sought to further characterize FL HSC/SRCs phenotypically and functionally before and following culture. Unexpanded or cultured FL cell suspensions were separated into various subpopulations. These were tested for long-term culture potential and for in vivo repopulating function following transplantation into NOD/SCID mice. We found that upon culture of human FL cells, a tight association between classical stem cell phenotypes, such as CD34(+) /CD38(-) and/or side population, and NOD/SCID repopulating function was lost, as observed with other sources. Although SRC activity before and following culture consistently correlated with the presence of a CD34(+) cell population, we provide evidence that, contrary to umbilical cord blood and adult sources, stem cells present in both CD34(+) and CD34(-) FL populations can sustain long-term hematopoietic cultures. Furthermore, upon additional culture, CD34-depleted cell suspensions, devoid of SRCs, regenerated a population of CD34(+) cells possessing SRC function. Our studies suggest that compared to neonatal and adult sources, the phenotypical characteristics of putative human FL HSCs may be less strictly defined, and reinforce the accumulated evidence that human FL represents a unique, valuable alternative and highly proliferative source of HSCs for clinical applications.

Fetal testosterone (2D:4D) as predictor of cognitive reflection

The Cognitive Reflection Test (CRT) is a test introduced by S. Frederick (2005) Cognitive reflection and decision making, J Econ Perspect 19(4): 25-42. The task is designed to measure the tendency to override an intuitive response that is incorrect and to engage in further reflection that leads to the correct response. The consistent sex differences in CRT performance may suggest a role for gonadal hormones, particularly testosterone. A now widely studied putative marker for fetal testosterone is the second-to-fourth digit ratio (2D:4D). This paper tests to what extent 2D:4D, as a proxy for prenatal exposure to testosterone, can predict CRT scores in a sample of 623 students. After controlling for sex, we observe that a lower 2D:4D (reflecting a higher exposure to testosterone) is significantly associated with a higher number of correct answers. The result holds for both hands? 2D:4Ds. In addition, the effect appears to be sharper for females than for males. We also control for patience and math proficiency, which are significantly related to performance in the CRT. But the effect of 2D:4D on performance in CRT is not reduced with these controls, implying that these variables are not mediating the relationship between digit ratio and CRT.

Digestibilidade, desempenho e características morfofisiológicas do trato digestório de leitões desmamados sob dietas com mananoligossacarídeo

O objetivo deste trabalho foi avaliar o efeito da adição do prebiótico mananoligossacarídeo (MOS) nas dietas de leitões sobre a digestibilidade dos nutrientes, o desempenho e as características morfofisiológicas do trato digestório. No primeiro experimento, foram utilizados 16 leitões com peso de 24,8±2,79 kg. Utilizou-se o método de coleta total de fezes para determinar a digestibilidade das rações controle e com 0,5% de prebiótico. No segundo experimento, avaliaram-se o desempenho e a incidência de diarreia em 30 leitoas com idade entre 22 e 63 dias e peso inicial de 6,28±1,40 kg. No terceiro experimento, foram avaliados a morfometria intestinal, os pesos relativos do fígado e do pâncreas e o pH dos conteúdos do estômago, intestino delgado e ceco em 15 leitoas com idade entre 22 e 63 dias e peso inicial de 5,74±0,93 kg. No segundo e terceiro experimentos, os tratamentos foram: controle positivo (dieta basal + sulfato de neomicina); controle negativo (dieta basal) e os tratamentos dieta basal acrescida de 0,25, 0,50 ou 0,75% de MOS. Utilizou-se o delineamento em blocos ao acaso. A utilização de diferentes níveis de mananoligassacarídeo nas dietas dos leitões não promove melhorias na digestibilidade dos nutrientes, no desempenho ou nas características morfofisiológicas do trato digestório.

Hyperammonemia: regulation of argininosuccinate synthetase and argininosuccinate lyase genes in aggregating cell cultures of fetal rat brain.

Hyperammonemia in the brain leads to poorly understood alterations of nitric oxide (NO) synthesis. Arginine, the substrate of nitric oxide synthases, might be recycled from the citrulline produced with NO by argininosuccinate synthetase (AS) and argininosuccinate lyase (AL). The regulation of AS and AL genes during hyperammonemia is unknown in the brain. We used brain cell aggregates cultured from dissociated telencephalic cortex of rat embryos to analyze the regulation of AS and AL genes in hyperammonemia. Using RNase protection assay and non-radioactive in situ hybridization on aggregate cryosections, we show that both AS and AL genes are induced in astrocytes but not in neurons of aggregates exposed to 5 mM NH4Cl. Our work suggests that the hyperammonemic brain might increase its recycling of citrulline to arginine.

Is screening for fetal anomalies reliable in HIV-infected pregnant women? A multicentre study.

OBJECTIVE: To assess the impact of HIV infection on the reliability of the first-trimester screening for Down syndrome, using free beta-human chorionic gonadotrophin, pregnancy-associated plasma protein-A and fetal nuchal translucency, and of the second-trimester screening for neural tube defects, using alpha-fetoprotein. PATIENTS AND METHODS: Multicentre study comparing the multiples of the median of markers for Down syndrome and neural tube defect screening among 214 HIV-infected pregnant women and 856 HIV-negative controls undergoing a first-trimester Down syndrome screening test, and 209 HIV-positive women and 836 HIV-negative controls with a risk evaluation for neural tube defect. The influence of treatment, chronic hepatitis and HIV disease characteristics were also evaluated. RESULTS: Multiples of the median medians for pregnancy-associated plasma protein-A and beta-human chorionic gonadotrophin were lower in HIV-positive women than controls (0.88 vs. 1.05 and 0.84 vs. 1.09, respectively; P < 0.005), but these differences had no impact on risk estimation; no differences were observed for the other markers. No association was found between HIV disease characteristics, antiretroviral treatment use at the time of screening or chronic hepatitis and marker levels. CONCLUSION: Screening for Down syndrome during the first trimester and for neural tube defect during the second trimester is accurate for HIV-infected women and should be offered, similar to HIV-negative women.

Proliferative and Osteogenic Differentiation Potentials of Human Fetal Bone Cells

BACKGROUND. Human primary fetal bone cells (hFBC) are being characterized for use in bone tissue regeneration. Unlike human mesenchymal stem cells (hMSC), hFBC are partially differentiated with high expansion and regeneration potential. To date, proliferative and osteoblastic differentiation capacities of fetal bone cells remain poorly examined. The goal of this study was to define an environmental culture conditions for optimal proliferation and production of extracellular bone matrix leading to efficient bone repair. METHODS. Human primary FBC derived from our dedicated, consistent banks of bone cells comprising several fetal donors. For proliferation study, monolayer cultures of both cell types were expanded in DMEM or α- MEM media. Osteoblastic differentiation potentials of both hFBC and hMSC were evaluated through RT-PCR. Regulation of osteogenic differentiation by protein ligands Wnt3a and Wnt5a was studied by ALP enzymatic activity measurement. RESULTS. Evaluation of the proliferation rate demonstrated that hFBC proliferated more rapidly in α-MEM medium. Regarding growth factors that could stimulate cell proliferation rate, we observed that PDGF, FGF2 and Wnt3a had positive effects on proliferation of hFBC. Gene expression analysis demonstrated a higher expression of runx2 in hFBC cultured in basal conditions, which was was similar than that was observed in hMSC in osteoinductive culture conditions. Expression of sox9 was very low in hBFC and hMSC, compared to expression observed in fetal cartilage cells. Looking at osteogenic differentiation capacity, ALP activity was positively regulated byWnt5awhen hFBCwere cultured inα-MEM, but not in DMEM. Conversely, Wnt3a was shown to block the effect of osteogenic inductors on differentiation of both cell types. CONCLUSION. Data presented in this study indicate that the proliferation and differentiation of fetal and mesenchymal stem cells is optimal in α- MEM. Evidence for a pre-differentiated state of hBFC was given by extracellular matrix spontaneous mineralization as well as by higher ALP activity levels observed for these cells in baseline culture conditions, in comparison with hMSC. As we showed that, in vitro, hFBC express a higher capacity to differentiate in osteoblasts, they represent an attractive and promising prospect for fundamental research, and specifically for a new generation of skeletal tissue engineering.

The fetal hypothalamus has the potential to generate cells with a gonadotropin releasing hormone (GnRH) phenotype.

BACKGROUND: Neurospheres (NS) are colonies of neural stem and precursor cells capable of differentiating into the central nervous system (CNS) cell lineages upon appropriate culture conditions: neurons, and glial cells. NS were originally derived from the embryonic and adult mouse striatum subventricular zone. More recently, experimental evidence substantiated the isolation of NS from almost any region of the CNS, including the hypothalamus. METHODOLOGY/FINDINGS: Here we report a protocol that enables to generate large quantities of NS from both fetal and adult rat hypothalami. We found that either FGF-2 or EGF were capable of inducing NS formation from fetal hypothalamic cultures, but that only FGF-2 is effective in the adult cultures. The hypothalamic-derived NS are capable of differentiating into neurons and glial cells and most notably, as demonstrated by immunocytochemical detection with a specific anti-GnRH antibody, the fetal cultures contain cells that exhibit a GnRH phenotype upon differentiation. CONCLUSIONS/SIGNIFICANCE: This in vitro model should be useful to study the molecular mechanisms involved in GnRH neuronal differentiation.