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1.
Zootaxa ; 5301(4): 461-468, 2023 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-37518550

RESUMO

A new species of parasitic isopod in the genus Ione Latreille, 1818, infesting the branchial chamber of the intertidal burrowing shrimp Neotrypaea tabogensis (Sakai, 2005) is described on the basis of material collected on the Pacific coast of Costa Rica. Diagnostic features of the new species include: (1) body shape of female asymmetrical with slight left distortion, pereon segments distinct; (2) head of female not fused with first pereomere, posterior margin nearly straight; (3) antenna of female composed of five articles; (4) posterior lamella of barbula of female with two tapered lobes on each side; (5) body of male elongated, clearly segmented dorsally; (6) head of male completely separated from the first pereomere; and (7) maxillipeds absent in male. This is the seventh valid species in the genus Ione and the first record of this genus from the tropical eastern Pacific. A key for identification of species of Ione is also provided.


Assuntos
Decápodes , Isópodes , Parasitos , Animais , Masculino , Feminino , Distribuição Animal , Estruturas Animais
2.
Front Immunol ; 12: 746492, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34737747

RESUMO

B-cell acute lymphoblastic leukemia (B-ALL) results from the expansion of malignant lymphoid precursors within the bone marrow (BM), where hematopoietic niches and microenvironmental signals provide leukemia-initiating cells (LICs) the conditions to survive, proliferate, initiate disease, and relapse. Normal and malignant lymphopoiesis are highly dependent on the BM microenvironment, particularly on CXCL12-abundant Reticular (CAR) cells, which provide a niche for maintenance of primitive cells. During B-ALL, leukemic cells hijack BM niches, creating a proinflammatory milieu incompetent to support normal hematopoiesis but favoring leukemic proliferation. Although the lack of a phenotypic stem cell hierarchy is apparent in B-ALL, LICs are a rare and quiescent population potentially responsible for chemoresistance and relapse. Here, we developed novel patient-derived leukemia spheroids (PDLS), an ex vivo avatar model, from mesenchymal stromal cells (MSCs) and primary B-ALL cells, to mimic specialized niche structures and cell-to-cell intercommunication promoting normal and malignant hematopoiesis in pediatric B-ALL. 3D MSC spheroids can recapitulate CAR niche-like hypoxic structures that produce high levels of CXCL10 and CXCL11. We found that PDLS were preferentially enriched with leukemia cells displaying functional properties of LICs, such as quiescence, low reactive oxygen species, drug resistance, high engraftment in immunodeficient mice, and long-term leukemogenesis. Moreover, the combination of PDLS and patient-derived xenografts confirmed a microenvironment-driven hierarchy in their leukemic potential. Importantly, transcriptional profiles of MSC derived from primary patient samples revealed two unique signatures (1), a CXCL12low inflammatory and leukemia expansion (ILE)-like niche, that likely supports leukemic burden, and (2) a CXCL11hi immune-suppressive and leukemia-initiating cell (SLIC)-like niche, where LICs are likely sustained. Interestingly, the CXCL11+ hypoxic zones were recapitulated within the PDLS that are capable of supporting LIC functions. Taken together, we have implemented a novel PDLS system that enriches and supports leukemia cells with stem cell features driven by CXCL11+ MSCs within hypoxic microenvironments capable of recapitulating key features, such as tumor reemergence after exposure to chemotherapy and tumor initiation. This system represents a unique opportunity for designing ex vivo personalized avatars for B-ALL patients to evaluate their own LIC pathobiology and drug sensitivity in the context of the tumor microenvironment.


Assuntos
Células-Tronco Neoplásicas/patologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Esferoides Celulares , Nicho de Células-Tronco , Células Tumorais Cultivadas , Animais , Medula Óssea/patologia , Feminino , Xenoenxertos , Humanos , Células-Tronco Mesenquimais/patologia , Camundongos , Microambiente Tumoral
3.
J Phys Chem B ; 125(32): 9268-9285, 2021 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-34357778

RESUMO

Diverse models of intramolecular charge transfer (ICT) have been proposed for interpreting the origin of the charge-transfer (CT) state in donor-acceptor (D-A) dyes. However, a large variety of fused-heterocyclic dyes containing a pseudo-aromatic ring in the rigid structure have shown to be incompatible with them. To approximate a solution within the ICT concept, we reported a novel ICT model called partially aromatized intramolecular charge transfer (PAICT). PAICT involves the generation of a CT state from an ICT that occurred within a pre-excited D-A fused-heterocyclic structure possessing a pseudo-aromatic or unstable aromatic ring as the acceptor moiety. The model was proposed from the multiple-emissive mesomeric D-A N1-aryl-2-(trifluoromethyl)benzo[b][1,8]naphthyridin-4(1H)-one, whose excited mesomeric states, which are defined by the aromatic and pseudo-aromatic forms of the pyrindin-4(1H)-one ring, led to a common partial aromatized CT state upon excitation via PAICT. The latter was supported through theoretical calculations on the excited mesomeric states, one-dimensional (1D) and two-dimensional (2D) excitation-emission measurements in different solvents, and the detection of three excited states by lifetime measurements upon 370 nm excitation. The existence of mesomerism was supposed from: (i) two overlapping bands at 370-390 (or 400-420 nm) in UV-vis spectra, (ii) the direct interaction between the pyridinic nitrogen of one molecule and the carbonylic oxygen of the other found in the solid state and, (iii) the detection of three excited states by lifetime measurements. The PAICT opens new perspectives for interpreting the charge-transfer phenomenon in fused-heterocyclic dyes, in particular, those containing a pseudo-aromatic or unstable aromatic ring as an acceptor moiety.


Assuntos
Corantes/química , Solventes
4.
FEBS Open Bio ; 10(11): 2305-2315, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32902187

RESUMO

Galectin-9 levels have been reported to be altered in several cancer types, but the mechanism that regulates the expression of Galectin-9 has not been clarified. Galectin-9 is encoded by the LGALS9 gene, which gives rise to eight mRNA variants. The aims of this study were: (a) to identify the mRNA variants of LGALS9, (b) to characterize CpG methylation and H3K9 and H3K14 histone acetylation at the promoter of the LGALS9 gene, and (c) to characterize the relationship between these modifications and LGALS9 expression level in cervical cancer cells. All mRNA variants were detected in HaCaT (nontumoural keratinocytes) and SiHa cells, and seven were observed in HeLa cells. The promoter region of LGALS9 contains eight CpG dinucleotides. No hypermethylation pattern related to low LGALS9 expression was identified in tumour cells. Chromatin immunoprecipitation analysis demonstrated higher acetylation of H3K9ac and H3K14ac in HaCaT cells, which was related to higher mRNA levels. The presence of the mRNA variants suggests that alternative splicing may regulate the expression of galectin-9 isoforms. The results of this study suggest that histone acetylation, but not promoter CpG methylation, may be involved in the transcriptional regulation of the LGALS9 gene.


Assuntos
Galectinas/genética , Histonas/metabolismo , Regiões Promotoras Genéticas , Neoplasias do Colo do Útero/genética , Acetilação , Ilhas de CpG/genética , Metilação de DNA/genética , Feminino , Galectinas/metabolismo , Regulação Neoplásica da Expressão Gênica , Células HaCaT , Células HeLa , Humanos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
6.
Artigo em Espanhol | LILACS | ID: biblio-844746

RESUMO

Introducción Pese al aparente rol de la saliva como protector de la caries radicular, pocos estudios han estudiado la asociación con el flujo salival. Objetivo El propósito de este estudio fue determinar si un menor flujo salival se relaciona con un aumento en la prevalencia y actividad de la caries radicular en personas mayores autovalentes. Materiales y métodos Se aplicó una encuesta sociodemográfica y se solicitó una muestra de flujo salival no estimulado y estimulado a 332 personas mayores autovalentes. Mediante un examen clínico se obtuvo la presencia y actividad de la caries radicular utilizando los criterios ICDAS y los de Ekstrand, respectivamente. Se calculó el root caries index (RCI) y el porcentaje de caries radiculares activas (% CRA). Los datos fueron analizados con el test t de Student, Anova y Kruskal Wallis, con un nivel de significación de 0,05. Resultados El flujo salival fue menor en mujeres y disminuyó con el aumento de la cantidad de fármacos y enfermedades sistémicas (p < 0,05). Ni el RCI ni el % CRA mostraron diferencias significativas en relación con el flujo salival no estimulado, pese a que ambos fueron levemente mayores en sujetos con un flujo salival estimulado normal (p < 0,05). Conclusión El flujo salival no parece asociarse numéricamente con una mayor presencia o actividad de caries radicular en adultos mayores autovalentes.


Introduction Although the role of saliva in the protection against root caries has been widely controversial, few studies have examined the association with salivary flow. Objective To determine if a decreased salivary flow is related to increased prevalence and activity of root caries in the elderly living in the community. Materials and methods A cross-sectional study was conducted on 332 elderly participants. Subjects were interviewed, completed a sociodemographic questionnaire, were orally examined, and donated a sample from unstimulated and stimulated salivary flow. Clinical examinations were carried out to assess prevalence and activity of root caries using ICDAS criteria. The Root Caries Index (RCI) and percentage of Active Root Caries (ARC) were calculated. Data were analysed using the Student t test, ANOVA and Kruskal Wallis, with a significance level of .05. Results Salivary flow was significantly lower in women and in subjects with high drug consumption and systemic diseases (P < .05). Although neither RCI nor the percentage of ARC differed in relation to unstimulated salivary flow, they were slightly higher in people with normal stimulated salivary flow (P < .05). Conclusion Salivary flow does not appear to be numerically associated with the prevalence or the activity of root caries in independent older adults.


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Envelhecimento , Cárie Radicular/epidemiologia , Saliva/metabolismo , Chile , Estudos Transversais , Cárie Dentária/diagnóstico , Índice CPO , Inquéritos e Questionários
7.
Artigo em Inglês | MEDLINE | ID: mdl-25186797

RESUMO

The queen conch Strombus gigas is an endangered marine gastropod of significant economic importance across the Greater Caribbean region. This work reports for the first time the complete mitochondrial genome of S. gigas, obtained by FLX 454 pyrosequencing. The mtDNA genome encodes for 13 proteins, 22 tRNAs and 2 ribosomal RNAs. In addition, the coding sequences and gene synteny were similar to other previously reported mitogenomes of gastropods.


Assuntos
DNA Mitocondrial/química , Gastrópodes/genética , Genoma Mitocondrial , Animais , Composição de Bases , Espécies em Perigo de Extinção , Dados de Sequência Molecular , Análise de Sequência de DNA
8.
Rev Biol Trop ; 61(2): 683-700, 2013 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-23885583

RESUMO

In the continental Colombian Caribbean the conch resource exploitation and the status of snails populations has been poorly studied, which are reflected in the lack of fisheries management. This study assesses composition, population density and distribution of the gastropods species that make conch resource in La Guajira region. Underwater visual censuses for snails were performed between September-November 2009 in 145100x4m (400m2) transects, spanning a total area of 56920m2 between Riohacha and Cabo de la Vela. The study was complemented with the evaluation of composition, abundance and size of gastropods conch found in the discarded-by-fishermen shell mounds in 13 beaches. In October 2010 another 40 transects were evaluated (16 000 m2) from the Southern of Riohacha to the Camarones village (La Guajira). We found a total of 9911 snails belonging to 12 species, the most abundant being Strombus pugilis with 8 912 individuals and an average density of 1 538.4 +/- 3 662.6 ind./ha, followed by Vasum muricatum with 374 individuals and an average density of 51.8 +/- 91.2 ind./ha. Calculating the importance value index (IVI) for both living organisms as the empty shells on beaches, shows that Turbinella angulata is the most used species by artisanal fishermen in the region. Cassis madagascariensis and Cassis tuberosa are also important snail resources in the region (as suggested by the number of empty shells found in beaches), but its densities were low. Strombus gigas, with only three living organisms found in the area, presented the lowest abundance ever found in the Colombian Caribbean (0.52 +/- 3.6 ind./ha), showing that queen conch population in La Guajira cannot support commercial exploitation. The abundance of discarded S. gigas shells on beaches suggests resource exploitation in the recent past. Results remarks the urgency of implementing management plans for snail fisheries in the region.


Assuntos
Ecossistema , Pesqueiros , Gastrópodes/classificação , Animais , Colômbia , Comércio , Gastrópodes/anatomia & histologia , Humanos , Densidade Demográfica
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