Synthesis of new trypanocidal agents from the hybridisation of metronidazole and eugenol analogues.

Nitroimidazole compounds are well-known bioactive substances, and the structural activity relationship has been reported whereby the position of the nitro group within the imidazole ring has a large influence on the activity. This study focuses on synthesising new trypanocidal agents from the hybridisation of metronidazole with different natural phenols (eugenol, dihydroeugenol and guaiacol). Two different coupling methodologies have been explored in order to analyse the influence of the connector on bioactivity: i) classic direct esterification (AD compounds) and ii) "click" chemistry using a triazole connector (AC compounds). The in vitro trypanocidal tests show good results for both AC and AD hybrid compounds against both epimastigote and trypomastigote forms of T. cruzi. In silico studies showed positive data for most of the synthesised compounds and, in general present low toxicological risks. The AC compounds present lower ClogP (lipophilicity) values than those found for the AD series and higher TPSA (topological polar surface area) values, suggesting lower lipophilicity may be related to the presence of the triazole connector. The AD series compounds have higher Drug Score values than the AC series derivatives, suggesting better general properties for a pharmacological action.

Synthesis and antimicrobial activity of molecular hybrids based on eugenol and chloramphenicol pharmacophores.

In the constant search for new pharmacological compounds, molecular hybridisation is a well-known technique whereby two or more known pharmacophoric subunits are combined to create a new "hybrid" compound. This hybrid is expected to maintain the characteristics of the original compounds whilst demonstrating improvements to their pharmacological action. Accordingly, we report here a series of molecular hybrid compounds based upon eugenol and chloramphenicol pharmacophores. The hybrid compounds were screened for their in vitro antimicrobial potential against Gram-negative and Gram-positive bacteria and also rapidly growing mycobacteria (RGM). The results highlight that the antimicrobial profiles of the hybrid compounds improve in a very clear fashion when moving through the series. The most prominent results were found when comparing the activity of the hybrid compounds against some of the multidrug-resistant clinical isolates of Pseudomonas aeruginosa, methicillin-resistant clinical isolates of Staphylococcus aureus (MRSA) and clinical isolates of rapidly growing mycobacteria.

Multiple introgression events during the diversification history of the edible Mexican grasshopper genus Sphenarium (Orthoptera: Pyrgomorphidae).

Speciation with gene flow often leads to ambiguous phylogenetic reconstructions, reticulate patterns of relatedness and conflicting nuclear versus mitochondrial (mt) lineages. Here we employed a fragment of the COI mtDNA gene and nuclear genome-wide data (3RAD) to assess the diversification history of Sphenarium, an orthopteran genus of great economic importance in Mexico that is presumed to have experienced hybridisation events in some of its species. We carried out separate phylogenetic analyses to evaluate the existence of mito-nuclear discordance in the species relationships, and also assessed the genomic diversity and population genomic structure and investigated the existence of interspecific introgression and species limits of the taxa involved based on the nuclear dataset. The species delineation analyses discriminated all the currently recognised species, but also supported the existence of four undescribed species. The mt and nuclear topologies had four discordant species relationships that can be explained by mt introgression, where the mt haplotypes of S. purpurascens appear to have replaced those of S. purpurascens A and B, S. variabile and S. zapotecum. Moreover, our analyses supported the existence of nuclear introgression events between four species pairs that are distributed in the Sierra Madre del Sur province in southeast Mexico, with three of them occurring in the Tehuantepec Isthmus region. Our study highlights the relevance of genomic data to address the relative importance of allopatric isolation versus gene flow in speciation.

Vitellogenin genes are transcribed in Culex quinquefasciatus ovary

BACKGROUND Culex quinquefasciatus, a cosmopolitan, domestic, and highly anthropophilic mosquito, is a vector of pathogenic arboviruses such as West Nile virus and Rift Valley virus, as well as lymphatic filariasis. The current knowledge on its reproductive physiology regarding vitellogenin expression in different tissues is still limited. OBJECTIVES In this study, we analysed the transcriptional profiles of vitellogenin genes in the fat body and ovaries of C. quinquefasciatus females during the first gonotrophic cycle. METHODS C. quinquefasciatus ovaries and/or fat bodies were dissected in different times during the first gonotrophic cycle and total RNA was extracted and used for reverse transcription polymerase chain reaction, quantitative real time-PCR, and in situ hybridisation. FINDINGS We confirmed the classical descriptions of the vitellogenic process in mosquitoes by verifying that vitellogenin genes are transcribed in the fat bodies of C. quinquefasciatus females. Using RNA in situ hybridisation approach, we showed that vitellogenin genes are also transcribed in developing ovaries, specifically by the follicle cells. MAIN CONCLUSIONS This is the first time that vitellogenin transcripts are observed in mosquito ovaries. Studies to determine if Vg transcripts are translated into proteins and their contribution to the reproductive success of the mosquito need to be further investigated.

Synthesis and Structure-Activity Relationship Studies of Novel Aryl Sulfonamides and Their Activity against Human Breast Cancer Cell Lines.

A series of structural analogs of aryl sulfonamide hybrid compounds were synthesised and their cytotoxic activity was evaluated against three human breast cancer cell lines (MCF-7, MDA-MB-231 and Hs 578T). The compounds were designed through electronic, hydrophobic and steric modifications using the chemical structure of N-{4-[(2-hydroxy-3-methoxy-5-propylphenyl)sulfamoyl]phenyl}acetamide (referred to as compound 7) as a starting point to then assess a structure-activity relationship (SAR) study. From the data generated, we observed that compounds 9, 10 and 11 (which have modifications in the substituents of the aryl sulfonamide), efficiently reduced the cell viability of MCF-7 and MDA-MB-231 cell cultures. Based on initial data, we selected compounds 10 and 11 for further investigations into their antiproliferative and/or cytotoxic profile against MDA-MB-231 cells, and we noted that compound 10 was the most promising compound in the series. Compound 10 promoted morphological changes and altered the dynamics of cell cycle progression in MDA-MB-231 cells, inducing arrest in G1/S transition. Taken together, these results show that the dihydroeugenol-aryl-sulfonamide hybrid compound 10 (which has an electron withdrawing nitro group) displays promising antiproliferative activity against MDA-MB-231 cell lines.

The relationship between tumour infiltrating lymphocytes, Epstein-Barr virus and Helicobacter pylori infection in gastric cancer.

Objective: Epstein-Barr virus (EBV) and Helicobacter pylori (HP) infections have been extensively recognised as gastric cancer (GC) triggers, and recent publications suggest they could behave as predictive markers for immune-modulating therapies. Tumour-infiltrating lymphocytes (TILs) have also been identified as a predictive biomarker for immunotherapy in different malignancies. This study aimed to investigate the association between EBV and HP infection with TIL levels in GC. Methods: TIL evaluation in haematoxylin-eosin was performed by a pathologist and density of CD3, CD8 and CD163 positive (immunohistochemistry staining) immune cells was calculated with the use of digital pathology software. EBV infection was detected by in situ hybridisation (ISH) and by quantitative polymerase chain reaction (qPCR). Methylation status of EBV-related genes was detected by PCR and a methylome analysis was performed by the Illumina Infinium MethylationEPIC BeadChip. HP status was detected by qPCR. Results: We included 98 resected GC Peruvian cases in our evaluation. Median TIL percentage was 30. The proportion of EBV+ detected by ISH was 24.1%, of EBV+ detected by qPCR was 41.8%, while 70% showed methylation of EBV-related genes, and 58.21% of cases were HP+. Younger age (p = 0.024), early stages (p = 0.001), HP+ (p = 0.036) and low CD8 density (p = 0.046) were associated with longer overall survival (OS). High TIL level was associated with intestinal subtype (p < 0.001), with grade 2 (p < 0.001), with EBV qPCR+ (p = 0.001), and with methylation of EBV-related genes (p = 0.007). Cases with high TIL level and cases that are EBV positive share eight genes with similarly methylated status in the metabolomic analysis. High CD8 density was associated with EBV PCR+ (p = 0.012) and HP- (0.005). Conclusion: Lower CD8 density and HP+ predict longer OS. High TIL level is associated with EBV+ and methylation of EBV-related genes, while lower CD8 density is associated with HP+ GC.

A Comparison of Peripheral Blood Smears, Autologous Cell Cultures, and Reverse Line Blot Hybridisation in Screening for Anaplasma/Ehrlichia in Roaming Dogs and Symptomatic Dogs in Trinidad.

This study compared two methods to detect cases of canine ehrlichiosis in a field setting. One method was a polymerase chain reaction for the 16S rRNA gene followed by reverse line blot hybridisation with genera and species-specific probes for Anaplasma/Ehrlichia. The second method was an autologous cell culture of peripheral leucocytes isolated from heparinised blood and maintained in a homologous canine serum in Dulbecco's Modified Eagle medium without antibiotics. The cultures were examined under light microscopy for inclusion bodies after 48 h. Leucocytes were successfully propagated for 20 of the 34 samples submitted for autologous cell culture. Inclusion bodies were observed after cell culture in leucocytes of eight dogs. Two dogs were positive to the Anaplasma/Ehrlichia genera probe and six dogs were positive to the E. canis probe after reverse line blot hybridisation. There was acceptable agreement between reverse line blot hybridisation and cell culture results. Both reverse line blot hybridisation and autologous cell cultures can be used to detect E. canis in subclinical and clinical cases of disease. A definitive diagnosis of E. canis is best achieved by a combination of clinical signs, positive autologous cell culture, and reverse line blot hybridisation results.

Understanding professional stratification and hybridisation in the medical profession: exploratory evidence from Brazilian federal university hospitals / Comprendiendo la estratificación e hibridación profesional en la profesión médica: evidencia exploratoria de los hospitales universitarios federales de Brasil / Compreendendo a estratificação profissional e hibridização na profissão médica: evidências exploratórias de hospitais universitários federais brasileiros

Abstract This paper explores drivers, implications, and trends of professional stratification and hybridisation in the medical profession employed in Brazilian substituir por: federal university hospitals (HUFs). Drawing on exploratory findings, we examine some repercussions of the migration of university hospitals to EBSERH, a public company established by the federal government to manage and organise HUFs integrated into the Unified Health System (SUS). Our research shows that transferring hospital administration to EBSERH has led to further internal stratification of the medical workforce. The shift from the logic of medical-academic professionalism to the new logic of business-like healthcare, with the adoption of distinct job contracts and more managerial logics of work and control, may well be changing subjective and formal links established between professionals, universities, and hospitals. We identify and discuss trends towards hybridisation and dehybridisation. These findings are relevant because this shift can have profound implications for the academic nature of HUFs and for the future of professionalism within these health and teaching organisations.

Resumen Este artículo explora impulsores, implicaciones y tendencias de la estratificación y la hibridación profesional en la profesión médica empleada en los hospitales universitarios federales brasileños (HUFs). A partir de hallazgos exploratorios, examinamos algunas de las repercusiones de la migración de los hospitales universitarios a la EBSERH, una empresa pública creada por el gobierno federal para administrar y organizar los HUFs integrados en el Sistema Único de Salud (SUS). Nuestra investigación muestra que la transferencia de la administración hospitalaria a la EBSERH ha llevado a una mayor estratificación interna de la fuerza laboral médica. El cambio de la lógica del profesionalismo médico-académico a una lógica empresarial en salud, con la adopción de diferentes regímenes de empleo y modos de trabajo y control más gerenciales, puede estar alterando los vínculos subjetivos y formales que se establecen entre los profesionales, las universidades y los hospitales involucrados. Se identifican y discuten tendencias hacia la hibridación y deshibridación. Estos hallazgos son relevantes porque tales cambios pueden tener profundas implicaciones para la naturaleza académica de los HUFs, así como para el futuro del profesionalismo dentro de estas organizaciones de salud y educación.

Resumo: Este artigo explora motivadores, implicações e tendências de estratificação e hibridização profissional na profissão médica atuante em hospitais universitários federais brasileiros (HUFs). Com base em achados exploratórios, examinamos algumas das repercussões da migração dos hospitais universitários para a EBSERH, uma empresa pública criada pelo governo federal para gerenciar e organizar os HUFs vinculados ao Sistema Único de Saúde (SUS). A pesquisa mostra que a transferência da administração hospitalar para a EBSERH tem acarretado maior estratificação interna da força de trabalho médica. A mudança da lógica de profissionalismo médico-acadêmico para uma nova lógica empresarial de saúde, com a adoção de distintos regimes empregatícios e formas de trabalho e controle mais gerenciais, podem estar alterando vínculos subjetivos e formais estabelecidos entre os profissionais, as universidades e os hospitais envolvidos. Tendências em direção à hibridização e desibridização foram identificadas e discutidas. Esses achados são relevantes tendo em vista que tais movimentos podem representar implicações profundas para a natureza acadêmica dos HUFs e para o futuro do profissionalismo nessas organizações de saúde e ensino.

The origin of the parrotfish species Scarus compressus in the Tropical Eastern Pacific: region-wide hybridization between ancient species pairs.

BACKGROUND: In the Tropical Eastern Pacific (TEP), four species of parrotfishes with complex phylogeographic histories co-occur in sympatry on rocky reefs from Baja California to Ecuador: Scarus compressus, S. ghobban, S. perrico, and S. rubroviolaceus. The most divergent, S. perrico, separated from a Central Indo-Pacific ancestor in the late Miocene (6.6 Ma). We tested the hypothesis that S. compressus was the result of ongoing hybridization among the other three species by sequencing four nuclear markers and a mitochondrial locus in samples spanning 2/3 of the latitudinal extent of the TEP. RESULTS: A Structure model indicated that K = 3 fit the nuclear data and that S. compressus individuals had admixed genomes. Our data could correctly detect and assign pure adults and F1 hybrids with > 0.90 probability, and correct assignment of F2s was also high in some cases. NewHybrids models revealed that 89.8% (n = 59) of the S. compressus samples were F1 hybrids between either S. perrico × S. ghobban or S. perrico × S. rubroviolaceus. Similarly, the most recently diverged S. ghobban and S. rubroviolaceus were hybridizing in small numbers, with half of the admixed individuals assigned to F1 hybrids and the remainder likely > F1 hybrids. We observed strong mito-nuclear discordance in all hybrid pairs. Migrate models favored gene flow between S. perrico and S. ghobban, but not other species pairs. CONCLUSIONS: Mating between divergent species is giving rise to a region-wide, multispecies hybrid complex, characterized by a high frequency of parental and F1 genotypes but a low frequency of > F1 hybrids. Trimodal structure, and evidence for fertility of both male and female F1 hybrids, suggest that fitness declines sharply in later generation hybrids. In contrast, the hybrid population of the two more recently diverged species had similar frequencies of F1 and > F1 hybrids, suggesting accelerating post-mating incompatibility with time. Mitochondrial genotypes in hybrids suggest that indiscriminate mating by male S. perrico is driving pre-zygotic breakdown, which may reflect isolation of this endemic species for millions of years resulting in weak selection for conspecific mate recognition. Despite overlapping habitat use and high rates of hybridization, species boundaries are maintained by a combination of pre- and post-mating processes in this complex.

Hybrids of Solanum corymbiflorumand S. diploconos(Solanaceae) –a hope for new commercial varieties of edible fruits / Híbridos de Solanum Corymbiflorum e S. diploconos (Solanaceae) –uma alternativa paranovas cultivares comerciais defrutas comestíveis

Solanum diploconos(Mart.) Bohs („guava tamarillo”) and Solanum corymbiflorum(Sendtn.) Bohs („hardy tamarillo”) are wild relatives to subtropical, orchard, small tree –Solanum betaceumCav. (called simply „tamarillo”). Both these species create edible fruits, but they have not been cultivated widely so far as fruit trees. However, each one of these species has valuable features. Solanum corymbiflorumis quite hardy to frost, deciduous and early blooming both in fenological year time as well as in its lifespan but has untasty fruits. Solanum diploconoshas quite good tasting fruits and it is pest and disease resistant. This work has been an attempt to connect their best features in hybrids to create new, potentially commercial cultivars to grow as fruit plants. Three types of hybrids were created: F1 hybrid type –Solanum corymbiflorum× Solanum diploconos, BC1 backrossing type -(Solanum corymbiflorum× Solanum diploconos) × Solanum corymbiflorum and the second BC1 backcrossing type –(Solanum corymbiflorum× Solanum diploconos) × Solanum diploconos. Out of the numerous variable individuals within each type, we selected three very valuable from an agronomic point of view cultivars (Solanum'Lynn', 'Pinczow Springs' and 'Iwona'). The work with crossing and selecting the next cultivars will be continued.

Solanum diploconos(Mart.) Bohs (”guava tamarillo”) e Solanum corymbiflorum(Sendtn.) Bohs (”hardy tamarillo”) são espécies silvestres de forma arbustiva –Solanum betaceumCav. (chamado simplesmente “tamarillo”). Ambas as espécies geram frutos comestíveis, mas não têm sido cultivadas como árvores frutíferas. Entretanto, cada uma destas espécies tem características valiosas. Solanum corymbiflorumé bastante resistente à geada, perde suas folhas periodicamente e possui floração precoce, tanto no ano fenológico como em sua vida útil, mas tem frutos pouco saborosos. No entanto, Solanum diploconostem frutos bastante saborosos e é resistente a pragas e doenças. Este estudo foiuma tentativa de captar as melhores características existentes em híbridos para criar novas cultivares, potencialmente comerciais, e que possam desenvolver como planta frutífera. Três tipos de híbridos foram criados: tipo híbrido F1 –(Solanum corymbiflorum× Solanum diploconos), tipo BC1 retrocruzamento -(Solanum corymbiflorum× Solanum diploconos) × Solanum corymbiflorume o segundo tipo BC1 retrocruzamento -(Solanum corymbiflorum× Solanum diploconos) × Solanum diploconos. Dos numerosos indivíduos variáveis dentro de cada tipo, foram selecionados três cultivares muito valiosas do ponto de vista agronômico (Solanum'Lynn', 'Pinczow Springs' e 'Iwona'). O trabalho de cruzamento e seleção das próximas cultivares terá continuidade e aprimoramento.

Hybrids of Solanum corymbiflorumand S. diploconos(Solanaceae) –a hope for new commercial varieties of edible fruits / Híbridos de Solanum Corymbiflorum e S. diploconos (Solanaceae) –uma alternativa paranovas cultivares comerciais defrutas comestíveis

Solanum diploconos(Mart.) Bohs („guava tamarillo”) and Solanum corymbiflorum(Sendtn.) Bohs („hardy tamarillo”) are wild relatives to subtropical, orchard, small tree –Solanum betaceumCav. (called simply „tamarillo”). Both these species create edible fruits, but they have not been cultivated widely so far as fruit trees. However, each one of these species has valuable features. Solanum corymbiflorumis quite hardy to frost, deciduous and early blooming both in fenological year time as well as in its lifespan but has untasty fruits. Solanum diploconoshas quite good tasting fruits and it is pest and disease resistant. This work has been an attempt to connect their best features in hybrids to create new, potentially commercial cultivars to grow as fruit plants. Three types of hybrids were created: F1 hybrid type –Solanum corymbiflorum× Solanum diploconos, BC1 backrossing type -(Solanum corymbiflorum× Solanum diploconos) × Solanum corymbiflorum and the second BC1 backcrossing type –(Solanum corymbiflorum× Solanum diploconos) × Solanum diploconos. Out of the numerous variable individuals within each type, we selected three very valuable from an agronomic point of view cultivars (Solanum'Lynn', 'Pinczow Springs' and 'Iwona'). The work with crossing and selecting the next cultivars will be continued.(AU)

Solanum diploconos(Mart.) Bohs (”guava tamarillo”) e Solanum corymbiflorum(Sendtn.) Bohs (”hardy tamarillo”) são espécies silvestres de forma arbustiva –Solanum betaceumCav. (chamado simplesmente “tamarillo”). Ambas as espécies geram frutos comestíveis, mas não têm sido cultivadas como árvores frutíferas. Entretanto, cada uma destas espécies tem características valiosas. Solanum corymbiflorumé bastante resistente à geada, perde suas folhas periodicamente e possui floração precoce, tanto no ano fenológico como em sua vida útil, mas tem frutos pouco saborosos. No entanto, Solanum diploconostem frutos bastante saborosos e é resistente a pragas e doenças. Este estudo foiuma tentativa de captar as melhores características existentes em híbridos para criar novas cultivares, potencialmente comerciais, e que possam desenvolver como planta frutífera. Três tipos de híbridos foram criados: tipo híbrido F1 –(Solanum corymbiflorum× Solanum diploconos), tipo BC1 retrocruzamento -(Solanum corymbiflorum× Solanum diploconos) × Solanum corymbiflorume o segundo tipo BC1 retrocruzamento -(Solanum corymbiflorum× Solanum diploconos) × Solanum diploconos. Dos numerosos indivíduos variáveis dentro de cada tipo, foram selecionados três cultivares muito valiosas do ponto de vista agronômico (Solanum'Lynn', 'Pinczow Springs' e 'Iwona'). O trabalho de cruzamento e seleção das próximas cultivares terá continuidade e aprimoramento.(AU)

VGLUT-VGAT expression delineates functionally specialised populations of vasopressin-containing neurones including a glutamatergic perforant path-projecting cell group to the hippocampus in rat and mouse brain.

The origin and functional significance of vasopressin (AVP)-containing fibres in limbic regions has been an ongoing subject of investigation for several years. We have previously identified AVP-magnocellular neurones of rat hypothalamus that provide glutamatergic projections to the hippocampus, amygdala, lateral habenula and locus coeruleus. However, we also reported AVP-immunopositive fibres in those regions that are thin and make Gray type II synapses, which are unlikely to be of magnocellular origin. Therefore, in the present study, we characterised AVP mRNA co-expression with expression of mRNAs marking glutamatergic (vesicular glutamate transporter [VGLUT]) and GABAergic (vesicular GABA transporter [VGAT]) neuronal traits in rat and mouse brain, using high-resolution in situ hybridisation methods, including a radio-ribonucleotide and RNAscope 2.5 HD duplex assay, with Slc17a7, Slc17a6, Slc32a1 and Avp probes corresponding to mRNAs of VGLUT1, VGLUT2, VGAT and AVP, respectively. We located 18 cell groups expressing Avp and identified their molecular signatures for VGLUT and VGAT mRNA expression. Avp cell groups of hypothalamus and midbrain are mainly VGLUT mRNA-expressing, whereas those in regions derived from cerebral nuclei are mainly VGAT mRNA-expressing, suggesting a functional segregation of glutamate/GABA co-transmission with AVP. A newly identified Slc17a7 and Slc17a6 (but not Slc32a1) expressing vasopressinergic cell group was found in layer II-III neurones of the central entorhinal cortex, which projects to the hippocampus. These data support the notion of a complex role for AVP with respect to modulating multiple central circuits controlling behaviour in specific ways depending on co-transmission with glutamate or GABA, potentially giving rise to a functional classification of AVPergic neurones in the central nervous system.

A multiple comparative study of putative endosymbionts in three coexisting apple snail species.

We here compare morphological and molecular characters of some putative endosymbiotic elements of the digestive gland of three ampullariid species (Pomacea canaliculata, Pomacea scalaris and Asolene platae) which coexist in Lake Regatas (Palermo, Buenos Aires). The putative endosymbionts were reported in these species and were identified as C and K corpuscles. The three species show tubuloacinar glands, each adenomere was constituted mainly by two distinct cell types (columnar and pyramidal). C and K corpuscles together occupied from one-fourth to one-fifth of the tissue area in the three host species, where C corpuscles were round and greenish-brown, were delimited by a distinct wall, stained positively with Alcian Blue and were associated with columnar cells. K corpuscles were oval, dark-brown multilamellar bodies and were associated with pyramidal cells. Under TEM, C corpuscles occurred within vacuoles of columnar cells and contained many electron-dense clumps and irregular membrane stacks and vesicles spread in an electron-lucent matrix. Sometimes a membrane appeared detached from the inner surface of the wall, suggesting the existence of a plasma membrane. In turn, K corpuscles were contained within vacuoles of pyramidal cells and were made of concentric lamellae, which were in turn made of an electron-dense fibrogranular material. No membranes were seen in them. Interspecifically, C corpuscles vary significantly in width and inner contents. K corpuscles were also variable in length and width. However, both C and K corpuscles in the three studied species hybridised with generalised cyanobacterial/chloroplast probes for 16S rRNA. Also, both corpuscle types (isolated from gland homogenates) were sensitive to lysozyme digestion, which indicates that bacterial peptidoglycans are an integral part of their covers. The reported data confirm and extend previous studies on P. canaliculata in which the endosymbiotic nature of C and K corpuscles were first proposed. We further propose that the endosymbiotic corpuscles are related to the Cyanobacteria/chloroplasts clade. Based on the known distribution of these corpuscles in the major clades of Ampullariidae, we hypothesise they may be universally distributed in this family, and that may constitute an interesting model for studying the co-evolution of endosymbionts and their gastropod hosts.

Evaluation of the expression of the oncogen C-ERBB-2/HER2 in advanced gastric cancer cases from Costa Rica.

JUSTIFICATION: The prevalence of gastric cancer (GC) with increased expression of the HER2 oncoprotein shows important variations worldwide. Incidence and mortality rates of GC in Costa Rica are among the highest in Latin America and the world; however, the prevalence of HER2-positive cases in this country is unknown. Evaluation of this parameter is important to decide the therapeutic approach for GC patients. The aim of this study was to provide an estimation of the prevalence of GC patients overexpressing the HER2 oncogene in Costa Rica. METHODS: The investigation was carried out in two phases. The first one consisted of a retrospective review of 331 clinical records of patients diagnosed with advanced or metastatic GC from January 2010 to January 2012 in four hospitals in Costa Rica. In the second phase, immunohistochemistry (IHC) and fluorescent in situ hybridisation (FISH) analyses were performed in formalin-fixed and paraffin-embedded (FFPE) surgical samples from 50 patients diagnosed with GC between 2012 and 2015. RESULTS: Of the 331 clinical files reviewed, the assessment of HER2 status was carried out in 62 patients (18.7%), of which only five (8%) were HER2-positive. In the 50 surgical specimens in which IHC and FISH analyses were performed, two of them (4%) presented overexpression and amplification of the HER2 oncogene. CONCLUSION: This study suggests that the prevalence of GC cases overexpressing the HER2 oncogene in Costa Rica is less than 8%. This is the first attempt ever undertaken to estimate the prevalence of HER2-positivity in GC in Costa Rica.

Mycobacterium tuberculosis promotes genomic instability in macrophages

BACKGROUND Mycobacterium tuberculosis is an intracellular pathogen, which may either block cellular defensive mechanisms and survive inside the host cell or induce cell death. Several studies are still exploring the mechanisms involved in these processes. OBJECTIVES To evaluate the genomic instability of M. tuberculosis-infected macrophages and compare it with that of uninfected macrophages. METHODS We analysed the possible variations in the genomic instability of Mycobacterium-infected macrophages using the DNA breakage detection fluorescence in situ hybridisation (DBD-FISH) technique with a whole human genome DNA probe. FINDINGS Quantitative image analyses showed a significant increase in DNA damage in infected macrophages as compared with uninfected cells. DNA breaks were localised in nuclear membrane blebs, as confirmed with DNA fragmentation assay. Furthermore, a significant increase in micronuclei and nuclear abnormalities were observed in infected macrophages versus uninfected cells. MAIN CONCLUSIONS Genomic instability occurs during mycobacterial infection and these data may be seminal for future research on host cell DNA damage in M. tuberculosis infection.

Aquatic long-distance dispersal and vicariance shape the evolution of an ostracod species complex (Crustacea) in four major Brazilian floodplains.

Cladogenesis is often driven by the interplay of dispersal and vicariance. The importance of long-distance dispersal in biogeography and speciation is increasingly recognised, but still ill-understood. Here, we study faunal interconnectivity between four large Brazilian floodplains, namely the Amazon, Araguaia, Pantanal (on Paraguay River) and Upper Paraná River floodplains, investigating a species complex of the non-marine ostracod genus Strandesia. We use DNA sequence data from the mitochondrial COI and the nuclear Elongation Factor 1 alpha genes to construct molecular phylogenies and minimum spanning networks, to identify genetic species, analyse biogeographic histories and provide preliminary age estimates of this species complex. The Strandesia species complex includes five morphological and eleven genetic species, which doubles the known diversity in this lineage. The evolutionary history of this species complex appears to comprise sequences of dispersal and vicariance events. Faunal and genetic patterns of connectivity between floodplains in some genetic species are mirrored in modern hydrological connections. This could explain why we find evidence for (aquatic) long-distance dispersal between floodplains, thousands of kilometres apart. Our phylogenetic reconstructions seem to mostly indicate recent dispersal and vicariance events, but the evolution of the present Strandesia species complex could span up to 25 Myr, which by far exceeds the age of the floodplains and the rivers in their current forms.

Partial 18S rRNA sequences of apicomplexan parasite 'X' (APX), associated with flat oysters Ostrea chilensis in New Zealand.

Apicomplexa is a large phylum of parasitic protists renowned for significant negative health impacts on humans and livestock worldwide. Despite the prevalence and negative impacts of apicomplexans across many animal groups, relatively little attention has been given to apicomplexan parasites of invertebrates, especially marine invertebrates. Previous work has reported an apicomplexan parasite 'X' (APX), a parasite that has been histologically and ultrastructurally identified from the commercially important flat oyster Ostrea chilensis in New Zealand. This apicomplexan may exacerbate host vulnerability to the infectious disease bonamiosis. In this study, we report 18S rRNA sequences amplified from APX-infected O. chilensis tissues. Phylogenetic analyses clearly established that the 18S sequences were of apicomplexan origin; however, their detailed relationship to known apicomplexan groups is less resolved. Two specific probes, designed from the putative APX 18S rRNA sequence, co-localised with APX cells in in situ hybridisations, further supporting our hypothesis that the 18S sequences were from APX. These sequences will facilitate the future development of inexpensive and sensitive molecular diagnostic tests for APX, thereby assisting research focussed on the biology and ecology of this organism and its role in morbidity and mortality of O. chilensis.

Females drive asymmetrical introgression from rare to common species in Darwin's tree finches.

The consequences of hybridization for biodiversity depend on the specific ecological and evolutionary context in which it occurs. Understanding patterns of gene flow among hybridizing species is crucial for determining the evolutionary trajectories of species assemblages. The recently discovered hybridization between two species of Darwin's tree finches (Camarhynchus parvulus and C. pauper) on Floreana Island, Galápagos, presents an exciting opportunity to investigate the mechanisms causing hybridization and its potential evolutionary consequences under conditions of recent habitat disturbance and the introduction of invasive pathogens. In this study, we combine morphological and genetic analysis with pairing observations to explore the extent, direction and drivers of hybridization and to test whether hybridization patterns are a result of asymmetrical pairing preference driven by females of the rarer species (C. pauper). We found asymmetrical introgression from the critically endangered, larger-bodied C. pauper to the common, smaller-bodied C. parvulus, which was associated with a lack of selection against heterospecific males by C. pauper females. Examination of pairing data showed that C. parvulus females paired assortatively, whereas C. pauper females showed no such pattern. This study shows how sex-specific drivers can determine the direction of gene flow in hybridizing species. Furthermore, our results suggest the existence of a hybrid swarm comprised of C. parvulus and hybrid birds. We discuss the influence of interspecific abundance differences and susceptibility to the invasive parasite Philornis downsi on the observed hybridization and recommend that the conservation of this iconic species group should be managed jointly rather than species-specific.

Collinearity between potato (Solanum tuberosum L.) and wild relatives assessed by comparative cytogenetic mapping.

A major bottleneck to introgressive hybridization is the lack of genome collinearity between the donor (alien) genome and the recipient crop genome. Structural differences between the homeologs may create unbalanced segregation of chromosomes or cause linkage drag. To assess large-scale collinearity between potato and two of its wild relatives (Solanum commersonii and Solanum chacoense), we used BAC-FISH mapping of sequences with known positions on the RH potato map. BAC probes could successfully be hybridized to the S. commersonii and S. chachoense pachytene chromosomes, confirming their correspondence with linkage groups in RH potato. Our study shows that the order of BAC signals is conserved. Distances between BAC signals were quantified and compared; some differences found suggest either small-scale rearrangements or reduction/amplification of repeats. We conclude that S. commersonii and S. chacoense are collinear with cultivated Solanum tuberosum on the whole chromosome scale, making these amenable species for efficient introgressive hybridization breeding.

Use of fluorescent oligonucleotide probes for differentiation between Paracoccidioides brasiliensis and Paracoccidioides lutzii in yeast and mycelial phase

BACKGROUND Fluorescence in situ hybridisation (FISH) associated with Tyramide Signal Amplification (TSA) using oligonucleotides labeled with non-radioactive fluorophores is a promising technique for detection and differentiation of fungal species in environmental or clinical samples, being suitable for microorganisms which are difficult or even impossible to culture. OBJECTIVE In this study, we aimed to standardise an in situ hybridisation technique for the differentiation between the pathogenic species Paracoccidioides brasiliensis and Paracoccidioides lutzii, by using species-specific DNA probes targeting the internal transcribed spacer-1 (ITS-1) of the rRNA gene. METHODS Yeast and mycelial phase of each Paracoccidioides species, were tested by two different detection/differentiation techniques: TSA-FISH for P. brasiliensis with HRP (Horseradish Peroxidase) linked to the probe 5’ end; and FISH for P. lutzii with the fluorophore TEXAS RED-X® also linked to the probe 5’ end. After testing different protocols, the optimised procedure for both techniques was accomplished without cross-positivity with other pathogenic fungi. FINDINGS The in silico and in vitro tests show no reaction with controls, like Candida and Cryptococcus (in silico) and Histoplasma capsulatum and Aspergillus spp. (in vitro). For both phases (mycelial and yeast) the in situ hybridisation showed dots of hybridisation, with no cross-reaction between them, with a lower signal for Texas Red probe than HRP-TSA probe. The dots of hybridisation was confirmed with genetic material marked with 4’,6-diamidino-2-phenylindole (DAPI), visualised in a different filter (WU) on fluorescent microscopic. MAIN CONCLUSION Our results indicated that TSA-FISH and/or FISH are suitable for in situ detection and differentiation of Paracoccidioides species. This approach has the potential for future application in clinical samples for the improvement of paracoccidioidomycosis patients prognosis.