178 resultados para FETAL ABNORMALITIES


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Acquired genomic aberrations have been shown to significantly impact survival in several hematologic malignancies. We analyzed the prognostic value of the most frequent chromosomal changes in a large series of patients with newly diagnosed symptomatic myeloma prospectively enrolled in homogeneous therapeutic trials. All the 1064 patients enrolled in the IFM99 trials conducted by the Intergroupe Francophone du Myélome benefited from an interphase fluorescence in situ hybridization analysis performed on purified bone marrow plasma cells. They were systematically screened for the following genomic aberrations: del(13), t(11;14), t(4;14), hyperdiploidy, MYC translocations, and del(17p). Chromosomal changes were observed in 90% of the patients. The del(13), t(11;14), t(4;14), hyperdiploidy, MYC translocations, and del(17p) were present in 48%, 21%, 14%, 39%, 13%, and 11% of the patients, respectively. After a median follow-up of 41 months, univariate statistical analyses revealed that del(13), t(4;14), nonhyperdiploidy, and del(17p) negatively impacted both the event-free survival and the overall survival, whereas t(11;14) and MYC translocations did not influence the prognosis. Multivariate analyses on 513 patients annotated for all the parameters showed that only t(4;14) and del(17p) retained prognostic value for both the event-free and overall survivals. When compared with the currently used International Staging System, this prognostic model compares favorably. In myeloma, the genomic aberrations t(4;14) and del(17p), together with beta2-microglobulin level, are important independent predictors of survival. These findings have implications for the design of risk-adapted treatment strategies.

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The aim of this study was to culture human fetal bone cells (dedicated cell banks of fetal bone derived from 14 week gestation femurs) within both hyaluronic acid gel and collagen foam, to compare the biocompatibility of both matrices as potential delivery systems for bone engineering and particularly for oral application. Fetal bone cell banks were prepared from one organ donation and cells were cultured for up to 4 weeks within hyaluronic acid (Mesolis(®)) and collagen foams (TissueFleece(®)). Cell survival and differentiation were assessed by cell proliferation assays and histology of frozen sections stained with Giemsa, von Kossa and ALP at 1, 2 and 4 weeks of culture. Within both materials, fetal bone cells could proliferate in three-dimensional structure at ∼70% capacity compared to monolayer culture. In addition, these cells were positive for ALP and von Kossa staining, indicating cellular differentiation and matrix production. Collagen foam provides a better structure for fetal bone cell delivery if cavity filling is necessary and hydrogels would permit an injectable technique for difficult to treat areas. In all, there was high biocompatibility, cellular differentiation and matrix deposition seen in both matrices by fetal bone cells, allowing for easy cell delivery for bone stimulation in vivo. Copyright © 2011 John Wiley & Sons, Ltd.

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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.

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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.

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BACKGROUND AND OBJECTIVES: The thalamus exerts a pivotal role in pain processing and cortical excitability control, and migraine is characterized by repeated pain attacks and abnormal cortical habituation to excitatory stimuli. This work aimed at studying the microstructure of the thalamus in migraine patients using an innovative multiparametric approach at high-field magnetic resonance imaging (MRI). DESIGN: We examined 37 migraineurs (22 without aura, MWoA, and 15 with aura, MWA) as well as 20 healthy controls (HC) in a 3-T MRI equipped with a 32-channel coil. We acquired whole-brain T1 relaxation maps and computed magnetization transfer ratio (MTR), generalized fractional anisotropy, and T2* maps to probe microstructural and connectivity integrity and to assess iron deposition. We also correlated the obtained parametric values with the average monthly frequency of migraine attacks and disease duration. RESULTS: T1 relaxation time was significantly shorter in the thalamus of MWA patients compared with MWoA (P < 0.001) and HC (P ≤ 0.01); in addition, MTR was higher and T2* relaxation time was shorter in MWA than in MWoA patients (P < 0.05, respectively). These data reveal broad microstructural alterations in the thalamus of MWA patients compared with MWoA and HC, suggesting increased iron deposition and myelin content/cellularity. However, MWA and MWoA patients did not show any differences in the thalamic nucleus involved in pain processing in migraine. CONCLUSIONS: There are broad microstructural alterations in the thalamus of MWA patients that may underlie abnormal cortical excitability control leading to cortical spreading depression and visual aura.

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Numerous drug exposures do occur unintentionally at the beginning of pregnancy. On the other hand, pursuing drug treatment may be necessary in women who wish to be pregnant. In these situations risk evaluation has to be done in a precise and differentiated manner, taking into account at the same time the risk for the fetus and maternal health. Teratovigilance services are able to give a thorough information enabling to avoid unwarranted drug arrests or pregnancy terminations. In return, physician's catamnesis about the outcome of the pregnancy exposed to one or several therapeutic agents will increase the bulk of knowledge health professionals and pregnant women have at their disposal.

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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.

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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.

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Anorectal anomalies occurring with other anomalies or as part of syndromes were analyzed to determine how their epidemiological characteristics differed from those of isolated anal anomalies. Almost 15% of cases were chromosomal, monogenic or teratogenic syndromes, whereas the rest were of unknown cause including sequences (9.3%), VACTERL associations (15.4%) and multiple congenital anomalies (MCA) (60.2%). Almost half of babies with MCA had one or two VACTERL anomalies with distribution frequencies that did not differ significantly from those in babies with the full VACTERL association. There were considerable differences in the frequency of the VACTERL association among babies with different types of anorectal anomaly. Babies with anal anomalies occurring with sequences, VACTERL or MCA showed the same sex differences as babies with isolated anal anomalies, namely male predominance in anal atresia without fistula or cloaca, no sex difference in anal atresia with fistula, and female predominance in ectopic anus and congenital anal fistula. These anomalies, however, were associated with significantly lower mean gestational lengths and birth weights, and higher frequencies of fetal death and pregnancy termination than babies with isolated anal anomalies. Twins were more frequent in sequences, VACTERL and MCA than in isolated anomalies, monogenic syndromes or chromosome anomalies. Five cases were conjoined twins, representing 15% of all cases of twin pregnancies with an anal anomaly. Indeterminate sex was more frequent in babies with anal atresias without fistula than in those with fistula. Anal anomalies are defects of blastogenesis attributable to disorders in expression of pattern determining genes. The differential sex involvement in different types of anal anomaly may be manifestations of expression of the HY/SRY genes during blastogenesis or of X-linkage.

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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.

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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.