Resilience of the Aurivillius structure upon La and Cr doping in a Bi5Ti3FeO15 multiferroic.

Combining the experimental techniques of high-resolution X-ray diffraction, magnetometry, specific heat measurement, and X-ray photoelectron, Raman and dielectric spectroscopy techniques, we have studied the influence of La and Cr doping on the crystal structure and magnetism of the room temperature Aurivillius multiferroic Bi5Ti3FeO15 by investigating the physical properties of (Bi4La)Ti3FeO15 and Bi5Ti3 (Fe0.5Cr0.5)O15. The parent (Bi5Ti3FeO15) and the doped ((Bi4La)Ti3FeO15 and Bi5Ti3(Fe0.5Cr0.5)O15) compounds crystallize in the A21am space group, which is confirmed through our analysis of high-resolution synchrotron X-ray diffraction data obtained on phase-pure polycrystalline powders. We determined the oxidation states of the metal atoms in the studied compounds as Fe3+, Ti4+, Cr3+, and La3+ through the analysis of X-ray photoelectron spectroscopy data. The magnetic susceptibilities of the three compounds are marked by the absence of a long-range ordered ground state, but dominated by superparamagnetic clusters with dominant antiferromagnetic interactions. This signature of short-range magnetism is also seen in specific heat as a low temperature enhancement which is suppressed upon the application of external magnetic fields up to 8 T. Our dielectric spectroscopy experiments showed that the three studied compounds display similar features in the dielectric constant measured as a function of frequency. However, upon doping La at the Bi site, the width of the ferroelectric hysteresis loop increases for (Bi4La)Ti3FeO15 compared to that of the parent compound Bi5Ti3FeO15, and with Cr doping, Bi5Ti3(Fe0.5Cr0.5)O15 becomes a leaky dielectric. The resilience of the Aurivillius crystal structure towards doping of La at the Bi site and Cr at the Fe site is clearly seen in the bulk properties of magnetic susceptibility, specific heat and the average crystal structure. The relevance of changes in the local structure is evident from our Raman spectroscopy and X-ray pair distribution function studies.

Catalytic nanomedicine: a brief review of bionanocatalysts.

Catalytic nanomedicine is a research area and source of disruptive technology that studies the application of bionanocatalysts (organically functionalized mesoporous nanostructured materials with catalytic properties) in diverse areas such as disinfection, tissue regeneration in chronic wounds and oncology. This paper reviews the emergence of catalytic nanomedicine in 2006, its basic principles, main achievements and future perspectives, as well as giving a summary of the knowledge gaps that need to be addressed to exploit the full potential of this novel discipline. This review intends to foster knowledge dissemination regarding catalytic nanomedicine, and to encourage further research to elucidate the mechanisms and possible applications of these nanomaterials.

Assessing Nordihydroguaiaretic Acid Therapeutic Effect for Glioblastoma Multiforme.

In this study, we demonstrate that Raman microscopy combined with computational analysis is a useful approach to discriminating accurately between brain tumor bio-specimens and to identifying structural changes in glioblastoma (GBM) bio-signatures after nordihydroguaiaretic acid (NDGA) administration. NDGA phenolic lignan was selected as a potential therapeutic agent because of its reported beneficial effects in alleviating and inhibiting the formation of multi-organ malignant tumors. The current analysis of NDGA's impact on GBM human cells demonstrates a reduction in the quantity of altered protein content and of reactive oxygen species (ROS)-damaged phenylalanine; results that correlate with the ROS scavenger and anti-oxidant properties of NDGA. A novel outcome presented here is the use of phenylalanine as a biomarker for differentiating between samples and assessing drug efficacy. Treatment with a low NDGA dose shows a decline in abnormal lipid-protein metabolism, which is inferred by the formation of lipid droplets and a decrease in altered protein content. A very high dose results in cell structural and membrane damage that favors transformed protein overexpression. The information gained through this work is of substantial value for understanding NDGA's beneficial as well as detrimental bio-effects as a potential therapeutic drug for brain cancer.

Lupus eritematoso sistémico asociado al consumo crónico de cocaína / Systemic lupus erythematosus associated with chronic cocaine use

El lupus eritematoso sistémico (LES) es una enfermedad autoinmune, de etiología desconocida,que se manifiesta como una enfermedad sistémica pleomórfica, afectando,principalmente, a las mujeres. El mecanismo autoinmune del LES se ha visto asociado aldesarrollo del fenómeno de la célula LE. Este fenómeno consiste en la fagocitosis, por partede los neutrófiflos, de los núcleos liberados por las células opsonizadas por el anticuerpoanti-DNP y el complemento C3b. A partir de diferentes estudios, se ha visto relación multifactorialetiológica en la inducción de enfermedades autoinmunes, en la que se encuentrauna relación infrecuente con el consumo crónico de cocaína. Esto se explica a través deprocesos biológicos en los que se inhibe la fagocitosis de los restos celulares generados pordichas enfermedades. A continuación se presenta el caso de un paciente con antecedentede consumo de derivados de la benzoilecgonina, quien ingresa por manifestaciones constitucionales,pulmonares, renales, cutáneas y musculoesqueléticas, en quien los paraclínicosy la biopsia renal confirman el diagnóstico de LES con nefritis lúpica clase iv. Así mismo, sedestaca la relevancia de sospecha y diagnóstico temprano de dicha enfermedad y la correlacióncon el consumo de cocaína para dar tratamiento oportuno y evitar el progreso y suscomplicaciones...

Genetic abnormalities and patterns of antigenic expression in multiple myeloma.

Myelomatous plasma cells show a high heterogeneity both in their immunophenotypic characteristics as well as in their cytogenetic features. Thus far, no extensive studies have been carried out to explore whether such antigenic diversity is associated with specific genetic characteristics. We have investigated the relationship between the immunophenotypic profile at plasma cell and both their DNA ploidy status (evaluated by flow cytometry) and specific genetic features (ascertained by fluorescence in situ hybridization) in a large series of 915 patients with newly diagnosed multiple myeloma. The non-hyperdiploid multiple myeloma group (n = 454, 52%) was associated with a significantly higher frequency of positivity for CD28 and CD20 as well as a higher incidence of CD56(-) and CD117(-) cases (P < 0.001). Remarkably, 13q deletion and immunoglobulin heavy chain (IGH) gene rearrangements, which were significantly more common in non-hyperdiploid multiple myeloma, showed a strong association with CD117(-) cases. IGH translocation to 11q13 was associated with reactivity for CD20 (P < 0.001), down-regulation of CD56 (P < 0.001), and lack of expression of CD117 (P = 0.001). By contrast, IGH translocations to other chromosome partners were almost exclusively found among CD20(-) and CD117(-) cases (P < 0.001). These results suggest that genetic categories in multiple myeloma exhibit particular immunophenotypic profiles which in turn are strongly associated with the DNA ploidy status.

Chromosomal abnormalities are related to location and grade of osteoarthritis.

OBJECTIVE: To investigate the frequency of numerical aberrations of chromosomes 7, X and Y in patients with osteoarthritis (OA) by performing fluorescent in situ hybridization (FISH) studies on articular cartilage, and to correlate the chromosomal changes with the degree and location of articular involvement. PATIENTS: Thirty-four women and 10 men with OA were included in the study. As a control group, 6 women and 5 men operated for orthopedic disorders other than OA were analyzed. METHODS: FISH studies were performed on hip or knee cartilage, using two-color centromere-specific probes for chromosomes 7 & X for women and 7 & Y for men. RESULTS: FISH analysis revealed that 46% of OA patients had numerical abnormalities of chromosomes 7, X or Y. An extra chromosome 7 (trisomy 7) was present in 35% of patients with chromosomal aberrations. All males with OA lost the Y chromosome while 15% of the women had loss of one chromosome X (monosomy X). Trisomy 7 was associated with hip OA (p=0.019) and advanced OA according to the Kellgren and Lawrence classification (p=0.05). None of the 11 controls showed abnormalities in the chromosomes analyzed. CONCLUSIONS: FISH analysis showed the presence of numerical chromosomal abnormalities in the articular cartilage of patients with OA.

The value of fluorescence in situ hybridization for the detection of 11q in multiple myeloma.

BACKGROUND AND OBJECTIVES: A large number of chromosomal abnormalities have been detected in multiple myeloma (MM). The most frequent are chromosome 13q deletions and translocations affecting the immunoglobulin heavy chain gene (IGH). Recent studies using comparative genomic hybridization (CGH) have shown that gains of 11q represent one of the most frequent genomic changes in MM. However CGH is not generally used in routine clinical laboratories. DESIGN AND METHODS: In the present study, efficiency of fluorescent in situ analysis (FIS)H analysis in the detection of 11q abnormalities in MM patients was investigated. Cytogenetic and FISH studies with three different specific probes for the regions containing the genes BCL1 (11q13), ATM (11q22) and MLL (11q23) were simultaneously performed in 52 patients: 9 cases with 11q abnormalities detected by conventional cytogenetics and 43 cases without 11q abnormalities. FISH analysis identified 11q aberrations that were undetected by cytogenetics in 16 out the 43 cases (37%). RESULTS: Gains on 11q were present in 13 cases (30%) while rearrangements on 11q were observed in the remaining 3 cases. No losses were found. All 11q gains involved the three regions analyzed (BCL1, ATM and MLL genes) while only rearrangements of BCL1 were observed. In all control cases the 11q alterations were confirmed by FISH. A good overall correlation between CGH and FISH was observed. Nevertheless gains on BCL1, ATM and MLL genes were observed in 3 cases displaying a normal CGH. INTERPRETATION AND CONCLUSIONS: In summary, chromosomal abnormalities on 11q are frequent in MM. FISH studies demonstrate a high sensitivity at detecting this abnormality and should be used in the routine evaluation of MM.

Prognostic and biologic significance of chromosomal imbalances assessed by comparative genomic hybridization in multiple myeloma.

Cytogenetic abnormalities, evaluated either by karyotype or by fluorescence in situ hybridization (FISH), are considered the most important prognostic factor in multiple myeloma (MM). However, there is no information about the prognostic impact of genomic changes detected by comparative genomic hybridization (CGH). We have analyzed the frequency and prognostic impact of genetic changes as detected by CGH and evaluated the relationship between these chromosomal imbalances and IGH translocation, analyzed by FISH, in 74 patients with newly diagnosed MM. Genomic changes were identified in 51 (69%) of the 74 MM patients. The most recurrent abnormalities among the cases with genomic changes were gains on chromosome regions 1q (45%), 5q (24%), 9q (24%), 11q (22%), 15q (22%), 3q (16%), and 7q (14%), while losses mainly involved chromosomes 13 (39%), 16q (18%), 6q (10%), and 8p (10%). Remarkably, the 6 patients with gains on 11q had IGH translocations. Multivariate analysis selected chromosomal losses, 11q gains, age, and type of treatment (conventional chemotherapy vs autologous transplantation) as independent parameters for predicting survival. Genomic losses retained the prognostic value irrespective of treatment approach. According to these results, losses of chromosomal material evaluated by CGH represent a powerful prognostic factor in MM patients.