High chromosomal mobility of rDNA clusters in holocentric chromosomes of Triatominae, vectors of Chagas disease (Hemiptera-Reduviidae).

The subfamily Triatominae (Hemiptera-Reduviidae) includes more than 150 blood-sucking species, potential vectors of the protozoan Trypanosoma cruzi, causative agent of Chagas disease. A distinctive cytogenetic characteristic of this group is the presence of extremely stable chromosome numbers. Unexpectedly, the analyses of the chromosomal location of ribosomal gene clusters and other repetitive sequences place Triatominae as a significantly diverse hemipteran subfamily. Here, we advance the understanding of Triatominae chromosomal evolution through the analysis of the 45S rDNA cluster chromosomal location in 92 Triatominae species. We found the 45S rDNA clusters in one to four loci per haploid genome with different chromosomal patterns: On one or two autosomes, on one, two or three sex chromosomes, on the X chromosome plus one to three autosomes. The movement of 45S rDNA clusters is discussed in an evolutionary context. Our results illustrate that rDNA mobility has been relatively common in the past and in recent evolutionary history of the group. The high frequency of rDNA patterns involving autosomes and sex chromosomes among closely related species could affect genetic recombination and the viability of hybrid populations, which suggests that the mobility of rDNA clusters could be a driver of species diversification.

IFN-γ mRNA expression is lower in Holstein cows infected with bovine leukemia virus with high proviral load and persistent lymphocytosis.

Bovine leukemia virus (BLV) is a retrovirus that affects primarily milky cows. Animals serologically positive to BLV show a Th1 cytokine profile with a predominance of interferon gamma (IFN-γ). IFN-γ has antiviral activity through mechanisms such as resistance to infection, inhibition of viral replication and apoptosis. The objective of this work was to determine the transcription levels of IFN-γ and its relationship with proviral load and persistent lymphocytosis in a population of Holstein cows of the province of Antioquia, Colombia. IFN-γ transcription levels were evaluated by qPCR in 140 Holstein cows. A one-way analysis of variance and a Student's t test were used to evaluate the differences between the means. The amount of IFN-γ mRNA found in BLV-positive cows was lower than in BLV-negative cows. Moreover, in the group of infected cows a lower level of IFN-γ mRNA expression was found in BLV and persistent lymphocytosis cows (BLV+PL) compared with BLV and aleukemia cows (BLV+AL). The level of IFN-γ mRNA expression was lower in cows with high proviral load (HPL) compared to cows with low proviral load (LPL). BLV infection is related to abnormal expression of IFN-γ mRNA, although IFN-γ has antiviral activity, its expression is affected by high proviral load. Keywords: cytokine; immune system; leukemia; bovine leukemia virus.

El componente racial influencia la resistencia a la infección con el virus de la leucosis bovina / The racial component influences resistance to infection with the bovine leukemia virus

RESUMEN El virus de la leucosis bovina (VLB) es un retrovirus que afecta principalmente el ganado lechero, reduciendo la producción de leche entre el 2,5 y 5%. La raza criolla colombiana Blanco Orejinegro (BON) es una raza rustica, bien adaptada, que ha mostrado resistencia in vitro a las infecciones ocasionadas por los virus de la fiebre aftosa y la estomatitis vesicular, así como las originadas por la bacteria Brucella abortus. El objetivo del presente estudio fue determinar si la raza BON y su cruce con Holstein son resistentes a la infección por el VLB. Se tomaron 124 muestras de sangre (59 Holstein, 40 BON y 25 BON x HOL) del mismo hato, se extrajo el DNA y se realizó una PCR-anidada correspondiente a una región del gen env de VLB. Se obtuvo un fragmento de 444 pb en los animales positivos. La prevalencia molecular del hato fue 33% para VLB. Se encontró diferencia significativa para infección por VLB entre los tres grupos raciales (p < 0,05). El porcentaje de infección fue del 55,9% para la raza Holstien, 5% para las vacas BON y 24% para el cruce BON x HOL; este último presentó una reducción en el porcentaje de infección del 32% respecto a la raza Holstein, lo cual puede ser atribuido a la presencia de genes de resistencia en la raza BON. Se comprobó que el nivel de infección es menor en vacas lecheras del cruce BON x HOL que en la raza lechera Holstein.

ABSTRACT The bovine leukemia virus (BLV) is a retrovirus that primarily affects dairy cattle, reducing milk production between 2.5 and 5%. The Colombian Blanco Orejinegro (BON) is a well-adapted, rustic, creole breed resistant to in vitro infections of Foot-and-mouth disease virus and vesicular stomatitis virus, as well as to Brucella abortus. This study aimed to determine if the crossing of BON and Holstein breeds is resistant to infection by BLV. Blood samples of 124 individuals (59 Holstein, 40 BON, and 25 BON x HOL) of the same herd were taken. The DNA was extracted, and a nested PCR was performed related to a region of the env gene of BLV. A fragment of 444 bp was obtained for positives animals. The molecular in-herd prevalence was 33% for BLV. A significant difference for BLV infection was found among the groups (p<0.05). The infection rate for the Holstein group was 55.9%, for BON cattle 5%, and for BON x HOL cattle 24%. The latter showed a reduction in the infection rate of 32% to the Holstein breed, which can be attributed to the presence of resistance genes in the BON breed. It was found that the level of infection is lower in BON x HOL cattle in contrast with Holstein dairy cows.

UNA APROXIMACIÓN ECONÓMICA A LOS DERECHOS COLECTIVOS Y SUS MEDIOS DE PROVISIÓN: EL CASO DE LOS DERECHOS AL "MEDIO AMBIENTE SANO" Y AL "MANEJO Y APROVECHAMIENTO RACIONAL DE LOS RECURSOS NATURALES" / AN ECONOMIC APPROACH TO COLLECTIVE RIGHTS AND THEIR MEANS OF PROVISION: THE CASE OF RIGHTS TO "HEALTHY ENVIRONMENT" AND TO "RATIONAL MANAGEMENT AND USE OF NATURAL RESOURCES"

El presente trabajo tiene dos objetivos: (i) Demostrar que la característica de los derechos colectivos relacionada con no exclusión de los beneficios derivados de los "medios" de provisión y de los "objetos" sobre los que aquellos recaen, es una idea consistente con la característica que, desde la perspectiva microeconómica, define simultáneamente a los denominados como recursos no excluyentes. (ii) Demostrar que al analizarse los derechos colectivos desde la perspectiva mencionada, ello supone retos inadvertidos por la doctrina jurídica tradicional, y relacionados con la adecuada provisión de los derechos, ello, por los problemas adjudicados comúnmente a la lógica (olsoniana) de la acción colectiva. El trabajo se refiere estrictamente a los derechos relativos al medio ambiente y el uso de recursos naturales.

This article has two main objectives: (i) To demonstrate that the collective rights characteristics related to inclusiveness of the benefits derived from the "means" of provision and the "objects" on which those fall, is a consistent idea with the characteristic that from the microeconomic perspective, defines simultaneously the so-called not exclusive resources; (ii) To demonstrate that when collective rights are analyzed from the perspective mentioned above, this suppose challenges unnoticed by the traditional legal doctrine and related with the adequate provision of collective rights, which happens because of the problems commonly allotted to the logics (Olsonian) of collective action. This work refers strictly to collective rights related to the environment and the use of natural resources".

New complexes containing the internal alternative NADH dehydrogenase (Ndi1) in mitochondria of Saccharomyces cerevisiae.

Mitochondria of Saccharomyces cerevisiae lack the respiratory complex I, but contain three rotenone-insensitive NADH dehydrogenases distributed on both the external (Nde1 and Nde2) and internal (Ndi1) surfaces of the inner mitochondrial membrane. These enzymes catalyse the transfer of electrons from NADH to ubiquinone without the translocation of protons across the membrane. Due to the high resolution of the Blue Native PAGE (BN-PAGE) technique combined with digitonin solubilization, several bands with NADH dehydrogenase activity were observed on the gel. The use of specific S. cerevisiae single and double mutants of the external alternative elements (ΔNDE1, ΔNDE2, ΔNDE1/ΔNDE2) showed that the high and low molecular weight complexes contained the Ndi1. Some of the Ndi1 associations took place with complexes III and IV, suggesting the formation of respirasome-like structures. Complex II interacted with other proteins to form a high molecular weight supercomplex with a molecular mass around 600 kDa. We also found that the majority of the Ndi1 was in a dimeric form, which is in agreement with the recently reported three-dimensional structure of the protein.

Modification and functional inhibition of regulator of G-protein signaling 4 (RGS4) by 4-hydroxy-2-nonenal.

Oxidative stress has been implicated as a component of various pathologies including ischemia/reperfusion injury (IRI) and neurodegenerative diseases such as Parkinson's disease (PD) and schizophrenia. Similarly, regulator of G-protein signaling 4 (RGS4) has been implicated as an important player in each of these pathologies. RGS4, like other RGS proteins, is responsible for temporally regulating G-protein coupled receptor signaling by increasing the intrinsic GTPase activity of Gα subunit of the heterotrimeric signaling complex. In this study we evaluated whether modification by 4-hydroxy-2-nonenal (4HNE), a common lipid peroxidation product, inhibits RGS4. Using immunoprecipitation, we first determined RGS4 modification was occurring in cells at concentrations of 4HNE within reported physiological conditions. Following this determination, we evaluated modification of RGS4 by 4HNE by both Western blot and mass spectrometry (MS). Once it was established that covalent modification occurred only on cysteine containing constructs, tryptic digest followed by mass spectrometry analysis revealed modification occurs at cysteine residues 71, 148, and 183. In order to determine the effect 4HNE had on RGS4 activity, a steady-state colorimetric assay was used to analyze the GAP activity of Δ51-RGS4 as well as the cysteine null mutant. From the data, we determined that RGS4 activity can be modulated by 4HNE through modification at cysteine residues similar to previously reported small molecule inhibition of RGS4.

A high throughput screen for RGS proteins using steady state monitoring of free phosphate formation.

G-protein coupled receptors are a diverse group that are the target of over 50% of marketed drugs. Activation of these receptors results in the exchange of bound GDP for GTP in the Gα subunit of the heterotrimeric G-protein. The Gα subunit dissociates from the ß/γ subunits and both proceed to affect downstream signaling targets. The signal terminates by the hydrolysis of GTP to GDP and is temporally regulated by Regulators of G-protein Signaling (RGS) proteins that act as GTPase Activating Proteins (GAPs). This makes RGS proteins potentially desirable targets for "tuning" the effects of current therapies as well as developing novel pharmacotherapies. Current methods for evaluating RGS activity depend on laborious and/or expensive techniques. In this study we developed a simple and inexpensive assay for the steady state analysis of RGS protein GAP activity, using RGS4, RGS8 and RGS17 as models. Additionally, we report the use of RGS4 as a model for high throughput assay development. After initial setup, this assay can be conducted in a highly parallel fashion with a read time of less than 8 minutes for a 1536-well plate. The assay exhibited a robust Z-factor of 0.6 in a 1536-well plate. We conducted a pilot screen for inhibitors using a small, 2320 compound library. From this screen, 13 compounds were identified as compounds for further analysis. The successful development of this assay for high-throughput screening provides a low cost, high speed, simple method for assessing RGS protein activity.

Focused electron beam induced etching of titanium with XeF2.

Titanium is a relevant technological material due to its extraordinary mechanical and biocompatible properties, its nanopatterning being an increasingly important requirement in many applications. We report the successful nanopatterning of titanium by means of focused electron beam induced etching using XeF(2) as a precursor gas. Etch rates up to 1.25 × 10(-3) µm(3) s(-1) and minimum pattern sizes of 80 nm were obtained. Different etching parameters such as beam current, beam energy, dwell time and pixel spacing are systematically investigated, the etching process being optimized by decreasing both the beam current and the beam energy. The etching mechanism is investigated by transmission electron microscopy. Potential applications in nanotechnology are discussed.

Endodoncia preventiva: Protección pulpar mediante la técnica de eliminación de la caries en etapas (stepwise excavation) / Preventive endodontics: pulp protection using stepwise caries removal procedure

El tratamiento de la caries dentinaria profunda en dientes permanentes se ha venido realizando, generalmente, mediante la remoción completa y en una sola sesión de la dentina cariada, incluyendo la dentina blanda desmineralizada, sin tener en cuenta el potencial regenerador de la pulpa dental. Una complicación frecuentemente ligada a esta actitud es la exposición pulpar intraoperatoria que, en muchos casos, termina en tratamiento de conductos. Varios estudios han demostrado que la eliminación de la caries dentinaria profunda por etapas, en dos visitas con varios meses de diferencia, protege a la pulpa, disminuyendo la frecuencia de exposiciones pulpares, a la vez que permite la formación de dentina terciaria, con la consiguiente disminución del porcentaje de casos que requieren tratamiento endodóncico. En este artículo se analiza el estado del conocimiento y la evidencia científica sobre este tema (AU)

The treatment of deep dentine carious lesions in permanent teeth has included, generally, complete removal of affected dentin in a single session, including soft demineralized dentin, regardless of the regenerative potential of dental pulp. One complication often linked to this attitude is the pulp exposure, in many case sending in root canal treatment. Several studies have shown that the elimination of deep dentine caries instages, in two visits to several months apart, protects the pulp, reducing the frequency of pulp exposures, while allowing the development of tertiary dentin, with the consequent decrease in the percentage of cases requiring endodontic treatment. This article discusses the state of knowledge and scientific evidence on this topic (AU)

Asociación entre la diabetes mellitus y las infecciones crónicas orales de origen endodóncico / Association between diabetes mellitus and chronic oral infectious processes of endodontic origin

La evidencia científica disponible en la actualidad aporta abundantes datos a favor de la existencia de una relación entre la diabetes mellitus (DM) y dos infecciones crónicas orales de muy alta prevalencia, la enfermedad periodontal (EP) y la periodontitis apical crónica. Ambas infecciones crónicas orales comparten dos características importantes: 1) una microbiota anaerobia Gram negativa común y 2) en ambas aumentan los niveles locales de mediadores inflamatorios, pudiendo repercutir sobre los niveles sistémicos. La interrelación DM – infecciones crónicas orales se produciría a través del eje inflamación-estrés oxidativo. La DM se asocia a formas agresivas de enfermedad periodontal y a una mayor prevalencia de lesiones periapicales, a un mayor tamaño de las lesiones, a una mayor probabilidad de infecciones periapicales asintomáticas y a un peor pronóstico para los dientes tratados endodóncicamente. Por otra parte, la periodontitis apical crónica podría contribuir al descontrol metabólico del paciente diabético (AU)

The literature provides evidence on the relationship between diabetes mellitus (DM) and two chronic oral infections of high prevalence: periodontal disease (PD) and chronic apical periodontitis. Both infectious processes of the oral cavity share two characteristics: 1) a common gram-negative anaerobic microbiota and 2) increased local levels of cytokines and inflammatory mediators, which may affect the systemic levels. The interaction between DM and chronic oral infections is based in the inflammation-oxidative stress axis. DM is associated to aggressive forms of PD, higher prevalence and greater sizes of periapical lesions, and to worse prognosis for endodontically treated teeth. The results of some studies suggest that apical periodontitis could contribute to metabolic dyscontrol on diabetic patients (AU)

Medicina endodóncica: implicaciones sistémicas de la patología y terapéutica endodóncicas / Endodontic medicine: systemic implications of the endodontic pathology and treatment

Diferentes trabajos han encontrado asociación entre la enfermedad periodontal (EP) y el estado de salud general. Las infecciones crónicas de origen endodóncico comparten características importantes con la EP: 1)ambas son infecciones crónicas de la cavidad oral, 2)una y otra comparten una microbiota anaerobia Gram negativa común, y 3) en ambas aumentan los niveles locales de mediadores inflamatorios, pudiendo repercutir sobre los niveles sistémicos. Es pues, plausible suponer que la periodontitis apical crónica y el tratamiento endodóncico se asocien a las mismas alteraciones sistémicas a las que se asocia la EP; de hecho, se han publicado varios trabajos que los relacionan con la diabetes mellitus, el hábito tabáquico y la cardiopatía isquémica. La “medicina endodoncia” se perfila como uno de los retos de la Endodoncia en el siglo XXI. En este artículo se revisa el estado actual del conocimiento respecto a las implicaciones sistémicas de la patología y terapéutica endodóncicas (AU)

Diverse studies have found association between systemic health and periodontal disease (PD). On the other hand chronic endodontic infections have striking similarities with PD: 1) both are chronic infections affecting the oral cavity, 2)both pathologies share a common anaerobic gran-negative microbiota, and 2) both infections increase local levels of cytokines and inflammatory mediators, which may affect the systemic levels. By analogy, it is reasonable to suppose that chronic apical periodontitis and endodontic therapy could be associated with the same systemic disorders which associates to PD. Moreover, recently several reports have investigated the possible association between chronic apical periodontitis and endodontic treatment and diabetes mellitus, smoking status and coronary heart diseases. “Endodontic medicine” is emerging as one of the challenges that face Endodontics in the 21st century. This article reviews the current state of knowledge regarding systemic implications of endodontics pathology and treatment (AU)

Allosteric inhibition of the regulator of G protein signaling-Galpha protein-protein interaction by CCG-4986.

Regulator of G protein signaling (RGS) proteins act to temporally modulate the activity of G protein subunits after G protein-coupled receptor activation. RGS proteins exert their effect by directly binding to the activated Galpha subunit of the G protein, catalyzing the accelerated hydrolysis of GTP and returning the G protein to its inactive, heterotrimeric form. In previous studies, we have sought to inhibit this GTPase-accelerating protein activity of the RGS protein by using small molecules. In this study, we investigated the mechanism of CCG-4986 [methyl-N-[(4-chlorophenyl)sulfonyl]-4-nitro-benzenesulfinimidoate], a previously reported small-molecule RGS inhibitor. Here, we find that CCG-4986 inhibits RGS4 function through the covalent modification of two spatially distinct cysteine residues on RGS4. We confirm that modification of Cys132, located near the RGS/Galpha interaction surface, modestly inhibits Galpha binding and GTPase acceleration. In addition, we report that modification of Cys148, a residue located on the opposite face of RGS4, can disrupt RGS/Galpha interaction through an allosteric mechanism that almost completely inhibits the Galpha-RGS protein-protein interaction. These findings demonstrate three important points: 1) the modification of the Cys148 allosteric site results in significant changes to the RGS interaction surface with Galpha; 2) this identifies a "hot spot" on RGS4 for binding of small molecules and triggering an allosteric change that may be significantly more effective than targeting the actual protein-protein interaction surface; and 3) because of the modification of a positional equivalent of Cys148 in RGS8 by CCG-4986, lack of inhibition indicates that RGS proteins exhibit fundamental differences in their responses to small-molecule ligands.

Morphometric analysis of Triatoma dimidiata populations (Reduviidae:Triatominae) from Mexico and Northern Guatemala.

Triatoma dimidiata is one of the major vectors of Chagas disease in Latin America. Its range includes Mexico, all countries of Central America, Colombia, and Ecuador. In light of recent genetic analysis suggesting that the possible origin of this species is the Yucatan peninsula, we have analyzed populations from the state of Yucatan, San Luis Potosi, and Veracruz in Mexico, and a population from the southern region of the Yucatan peninsula located in Northern Guatemala, the region of El Peten. Classical morphometry including principal component, discriminant, sexual dimorphism, and wing asymmetry was analyzed. San Luis Potosi and Veracruz populations were indistinguishable while clearly separate from Yucatan and Peten populations. Despite important genetic differences, Yucatan and Peten populations were highly similar. Yucatan specimens were the smallest in size, while females were larger than males in all populations. Only head characters were necessary to distinguish population level differences, although wing fluctuating asymmetry was present in all populations. These results are discussed in light of recent findings suggesting genetic polymorphism in most populations of Triatoma dimidiata south of Chiapas to Ecuador.

Morphometric analysis of Triatoma dimidiata populations (Reduviidae: Triatominae) from Mexico and Northern Guatemala

Triatoma dimidiata is one of the major vectors of Chagas disease in Latin America. Its range includes Mexico, all countries of Central America, Colombia, and Ecuador. In light of recent genetic analysis suggesting that the possible origin of this species is the Yucatan peninsula, we have analyzed populations from the state of Yucatan, San Luis Potosi, and Veracruz in Mexico, and a population from the southern region of the Yucatan peninsula located in Northern Guatemala, the region of El Peten. Classical morphometry including principal component, discriminant, sexual dimorphism, and wing asymmetry was analyzed. San Luis Potosi and Veracruz populations were indistinguishable while clearly separate from Yucatan and Peten populations. Despite important genetic differences, Yucatan and Peten populations were highly similar. Yucatan specimens were the smallest in size, while females were larger than males in all populations. Only head characters were necessary to distinguish population level differences, although wing fluctuating asymmetry was present in all populations. These results are discussed in light of recent findings suggesting genetic polymorphism in most populations of Triatoma dimidiata south of Chiapas to Ecuador.

[Cholesterol granuloma of the choroid simulating a macular tumor]. / Granuloma de colesterol coroideo simulando un tumor macular.

CASE REPORT: We present a 76-year-old woman with a cholesterol granuloma of the choroid simulating a choroidal melanoma. DISCUSSION: Cholesterol granuloma in the choroid is a quite rare tumor with a characteristic histology of foreign body reactions surrounding cholesterol crystals.

Sodium and potassium transport in the halophilic yeast Debaryomyces hansenii.

Debaryomyces hansenii, a halophile yeast found in shallow sea waters and salty food products grows optimally in 0.6 M of either NaCl or KCl, accumulating high concentrations of Na(+) or K(+). After growth in NaCl or KCl, a rapid efflux of either accumulated cation was observed if the cells were incubated in the presence of KCl or NaCl, respectively, accompanied by a slower accumulation of the cation present in the incubation medium. However, a similar, rapid efflux was observed if cells were incubated in buffer, in the absence of external cations. This yeast shows a cation uptake activity of both (86)Rb(+) and (22)Na(+) with saturation kinetics, and much higher affinity for (86)Rb(+) than for (22)Na(+). The pH dependence of the kinetics constants was similar for both cations, and although K(m) values were higher at pH 8.0, there was also an increase in the V(max) values. The accumulation of (22)Na(+) was found to be increased in cells grown in the presence of 0.6 M NaCl. (86)Rb(+) was also accumulated more in these cells, but to a slightly greater extent. The inhibition kinetics of the uptake of (22)Na(+) by K(+), and that of (86)Rb(+) by Na(+) was found to be non-competitive. It can be concluded that Na(+) in D. hansenii is not excluded but instead, its metabolic systems must be resistant to high salt concentrations.

A molecular phylogeographic study based on DNA sequences from individual metacercariae of Paragonimus mexicanus from Guatemala and Ecuador.

A molecular phylogeographic study of Paragonimus mexicanus collected from Guatemala and Ecuador was performed. Genomic DNA was extracted from individual metacercariae, and two gene regions (partial mitochondrial cytochrome c oxidase subunit 1 (CO1) and the second internal transcribed spacer of the nuclear ribosomal gene repeat (ITS2)) were amplified by the polymerase chain reaction (PCR). Sequences segregated in a phylogenetic tree according to their geographic origins. ITS2 sequences from Ecuador and Guatemala differed at only one site. Pairwise distances among CO1 sequences within a country were always lower than between countries. Nevertheless, genetic distances between countries were less than between geographical forms of P. westermani that have been suggested to be distinct species. This result suggests that populations from Guatemala and Ecuador are genetically differentiated perhaps at the level of subspecies.