High level of novelty under the hood of convergent evolution.

Little is known about the extent to which species use homologous regulatory architectures to achieve phenotypic convergence. By characterizing chromatin accessibility and gene expression in developing wing tissues, we compared the regulatory architecture of convergence between a pair of mimetic butterfly species. Although a handful of color pattern genes are known to be involved in their convergence, our data suggest that different mutational paths underlie the integration of these genes into wing pattern development. This is supported by a large fraction of accessible chromatin being exclusive to each species, including the de novo lineage-specific evolution of a modular optix enhancer. These findings may be explained by a high level of developmental drift and evolutionary contingency that occurs during the independent evolution of mimicry.

Priority pesticides in Chile: Predicting their environmental distribution, bioaccumulation, and transport potential.

Agriculture is one of the main economic activities in Chile and is associated with extensive use of pesticides, which can represent a risk to the environment and to human health. Currently, there are over 400 pesticides approved for commerce in Chile, including chemicals banned in other countries (e.g., flocoumafen and chlorfenapyr). An empirical analysis of their potential environmental effects is difficult due to this large number, thus opening the doors for the use of computational tools for prioritization efforts based on their persistence, bioaccumulation, and transport potential in the environment. The main objectives of this study were to estimate the properties and environmental distribution of pesticides approved for commerce in Chile and to generate a priority list for further evaluation in local environments. We used the Estimation Program Interface Suite interface to estimate the distribution coefficients, half-lives, and bioaccumulation potential of all pesticides registered in the Chilean Agriculture and Livestock Services. Additionally, the Pov & LRTP Screening Tool was used to estimate their overall persistence and long-range transport potential in the environment. The results were used to develop a P-B-lon range transport (LRT) score, which considered persistence, bioaccumulation, and long-range transport potential. All pesticides were compared to a group of polychlorinated biphenyls (PCBs), used as reference compounds, to generate a list of priority pesticides with persistent organic pollutants characteristics. The results showed that most pesticides were distributed between the organic phase and water, where they also showed the longest half-lives and bioaccumulation potential. A group of 21 pesticides showed relatively high P-B-LRT scores, compared to PCBs, and were classified as priority compounds. The list was further refined based on the volume of sales for each pesticide.  Integr Environ Assess Manag 2023;19:676-683. © 2022 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Disruption of the odorant coreceptor Orco impairs foraging and host finding behaviors in the New World screwworm fly.

The evolution of obligate ectoparasitism in blowflies (Diptera: Calliphoridae) has intrigued scientists for over a century, and surprisingly, the genetics underlying this lifestyle remain largely unknown. Blowflies use odors to locate food and oviposition sites; therefore, olfaction might have played a central role in niche specialization within the group. In insects, the coreceptor Orco is a required partner for all odorant receptors (ORs), a major gene family involved in olfactory-evoked behaviors. Hence, we characterized the Orco gene in the New World screwworm, Cochliomyia hominivorax, a blowfly that is an obligate ectoparasite of warm-blooded animals. In contrast, most of the closely related blowflies are scavengers that lay their eggs on dead animals. We show that the screwworm Orco orthologue (ChomOrco) is highly conserved within Diptera, showing signals of strong purifying selection. Expression of ChomOrco is broadly detectable in chemosensory appendages, and is related to morphological, developmental, and behavioral aspects of the screwworm biology. We used CRISPR/Cas9 to disrupt ChomOrco and evaluate the consequences of losing the OR function on screwworm behavior. In two-choice assays, Orco mutants displayed an impaired response to floral-like and animal host-associated odors, suggesting that OR-mediated olfaction is involved in foraging and host-seeking behaviors in C. hominivorax. These results broaden our understanding of the chemoreception basis of niche occupancy by blowflies.

An early female lethal system of the New World screwworm, Cochliomyia hominivorax, for biotechnology-enhanced SIT.

BACKGROUND: The New World Screwworm fly (NWS), Cochliomyia hominivorax, is an ectoparasite of warm-blooded animals and a major pest of livestock in parts of South America and the Caribbean where it remains endemic. In North and Central America it was eradicated using the Sterile Insect Technique (SIT). A control program is managed cooperatively between the governments of the United States and Panama to prevent the northward spread of NWS from infested countries in South America. This is accomplished by maintaining a permanent barrier through the release of millions of sterile male and female flies in the border between Panama and Colombia. Our research team demonstrated the utility of biotechnology-enhanced approaches for SIT by developing a male-only strain of the NWS. The strain carried a single component tetracycline repressible female lethal system where females died at late larval/pupal stages. The control program can be further improved by removing females during embryonic development as larval diet costs are significant. RESULTS: The strains developed carry a two-component system consisting of the Lucilia sericata bottleneck gene promoter driving expression of the tTA gene and a tTA-regulated Lshid proapoptotic effector gene. Insertion of the sex-specifically spliced intron from the C. hominivorax transformer gene within the Lshid gene ensures that only females die when insects are reared in the absence of tetracycline. In several double homozygous two-component strains and in one "All-in-one" strain that had both components in a single construct, female lethality occurred at the embryonic and/or first instar larval stages when raised on diet without tetracycline. Laboratory evaluation for phenotypes that are relevant for mass rearing in a production facility revealed that most strains had fitness characteristics similar to the wild type J06 strain that is currently reared for release in the permanent barrier. Testing of an "All in one" strain under mass rearing conditions showed that the strain maintained the fitness characteristics observed in small-scale rearing. CONCLUSIONS: The early female lethal strains described here could be selected by the NWS Control Program for testing at large scale in the production facility to enhance the efficiency of the NWS eradication program.

Caracterización del acto suicida en el servicio médico legal de Concepción, Chile entre 2011-2015 / Characterization of the suicide act according to the autopsy reports released by the legal medical service of Concepción, Chile 2011-2015

INTRODUCCIÓN: El suicidio se define como el acto donde la propia persona se quita la vida intencionalmente. Actualmente es una problemática mundial y en aumento. El objetivo es caracterizar el acto suicida según los reportes de autopsias realizados por el Servicio Médico Legal (SML) Concepción, durante el periodo 2011-2015. MATERIAL Y MÉTODOS: Se realizó un estudio retrospectivo, descriptivo y trasversal de los informes de autopsia con causa suicidio realizadas por el SML Concepción, periodo 2011-2015 utilizándose las variables: genero, edad, procedencia, lugar de ocurrencia, estado civil, ocupación, patologías asociadas, causa de muerte, alcoholemia, examen toxicológico, llegada al centro asistencial, intentos previos y carta de aviso. Los datos se analizaron y tabularon mediante Microsoft Excel. El trabajo fue aprobado por comité de ética. RESULTADOS: Del total de autopsias 511 fueron suicidios, 83,3% eran hombres, edad promedio 44,8 años, 49,9% casados, 83,6% correspondían a la provincia de Concepción, 75% ocurrió en su domicilio, 88,8% causado por asfixia por ahorcamiento, 57,3% poseían alcoholemia negativa y 67,7% examen toxicológico negativo y solo un 5,1% llego a un centro asistencial. DISCUSIÓN: Las variables más prevalentes de nuestro estudio fueron edad de 20-29 años, género masculino, estado civil soltero y ocupación en empleo técnico. El método y lugar más frecuentes fueron el ahorcamiento y el domicilio respectivamente. Se observa una prevalencia mayor de intoxicación alcohólica que en cifras internacionales. La sustancia más prevalente en los análisis toxicológicos fue la cocaína. Se necesita ampliar la investigación en nuestro medio analizando factores de riesgo y diseñando nuevas estrategias de prevención

INTRODUCTION: Suicide can be defined as the act where the person finish their life intentionally. It is currently an increasing worldwide problematic. The objective is to characterize the suicide act according to the autopsies reports performed by the Legal Medical Service (SML) Concepción, during the period 2011-2015 MATERIAL AND METHOD: We released a retrospective, descriptive and transversal study with the autopsies reports performed by the SML Concepción described as suicide, between 2011­2015. We used variables such as: gender, age, procedence, place of ocurrence, marital state, occupation, comorbidities, death cause, blood alcohol concentration, toxicological results, arrival at a care center, previus attempts and warning letter. Data was analized and tabulated using Microsoft Excel. The study was previusly approved by an ethic committee. RESULTS: From the total autopsies released, 12.6% were suicides (511), from which 83.3% were men, 49.9% were married, 83.6% were from Concepcion, 75% of the suicides occurred at home, 88.8% were asphyxiation by hanging, 57.3% had a negative result of alcohol in blood and 67.7% had a negative toxicological test, 5.1% arrived at a care center. DISCUSSION: The most prevalent variables of our study were age 20-29, male gender, single marital status and occupation in technical employment. The most frequent method and place were hanging and domicile respectively. We observed a higher prevalence of alcohol intoxication than international studies. The most prevalent substance in the toxicological analyzes was cocaine. It is necessary to expand the research in our environment by analyzing risk factors and designing new prevention strategies.

Guías colombianas para el manejo del acné: una revisión basada en la evidencia por el Grupo Colombiano de Estudio en Acné

El acné es una enfermedad inflamatoria crónica que afecta, principalmente, adolescentes y adultos jóvenes. Se calcula que antes de los 21 años entre el 80 y el 90% de esta población ha estado expuesta a la enfermedad. Sin embargo, el acné puede persistir después de los 21 años y se sabe que 12% de las mujeres mayores de 25 años aún sufren de acné facial. El arsenal terapéutico para el acné consta de medicamentos tópicos y sistémicos que han demostrado su eficacia en la reducción de las lesiones. El mecanismo de acción de estos medicamentos está orientado, al menos, a uno de los cuatro factores fisiopatológicos reconocidos como responsables de la formación de las lesiones del acné, a saber: trastornos de la queratinización, hipersecreción sebácea, proliferación de Propionibacterium acnes o actividad inflamatoria in situ. La elección del tratamiento apropiado depende de varios factores, como la forma clínica de la enfermedad (de retención o inflamatoria), la gravedad de la misma y la respuesta del paciente a tratamientos previos. Asimismo, y entendiendo al acné como una enfermedad de carácter crónico, el tratamiento debe incluir una fase inicial con el objetivo de lograr una mayor reducción de la extensión y gravedad de las lesiones, y una fase de mantenimiento orientada a la prevención de las recaídas o exacerbaciones. Además, el resultado del tratamiento depende del cumplimiento del mismo y para lograrlo, es fundamental una adecuada relación médico-paciente. Este documento presenta el resultado de una revisión actualizada de la literatura, que incluye guías nacionales e internacionales para el manejo del acné y formula recomendaciones terapéuticas basadas en el mejor nivel de “evidencia” que se encontró. Su implementación permitirá la unificación de criterios con el objetivo de ofrecer un mejor manejo a los pacientes con la enfermedad, evitando así sus secuelas físicas y emocionales. Por otro lado, las guías presentan un marco científico y conceptual con la suficiente validez para su inclusión en los protocolos del plan obligatorio de salud.

Dermatilomanía y síndrome de Prader-Willi / Skin picking and Prader-Willi syndrome

Reportamos el caso de una mujer de 18 años con síndrome de Prader-Willi, con retardo mental, problemas de comportamiento –tales como hiperfagia y pellizcos en piel–, obesidad, hipogonadismo, estatura corta, manos pequeñas y ojos en “forma de almendra”; presentaba antecedentes de hipotonía en la edad neonatal. El síndrome de Prader-Willi es un trastorno congénito, raro, no hereditario, que afecta a 1 de cada 10.000 a 25.000 recién nacidos. Es causado por alteraciones en los genes paternos localizados en la región codificadora del cromosoma 15(q11.2-q13). Se caracteriza por hipotonía, retardo en el desarrollo, alteraciones en el comportamiento, obesidad, hiperfagia, facies característica, hipogonadismo, corta estatura y manifestaciones cutáneas.

Uso de anticuerpos monoclonales anti-CD20 (rituximab) en paciente con pénfigo vulgar grave / Use of monoclonal anti-CD20 (rituximab) in a patient with severe pemphigus vulgaris

El pénfigo vulgar es una enfermedad vesículo-ampollosa de carácter autoinmunitario que compromete la piel y las membranas mucosas, y presenta un curso crónico. La inmunopatogénesis se basa en la presencia de autoanticuerpos (IgG) producidos por linfocitos B y dirigidos contra la superficie de los queratinocitos, que generan pérdida de la adherencia intercelular y la formación de ampollas subepidérmicas. La morbimortalidad es variable, y es muy importante el manejo que se instaure. Se han utilizado múltiples tratamientos inmunosupresores, principalmente corticosteroides sistémicos y múltiples inmunorreguladores, sin embargo, en algunos casos resistentes o ante la presencia de efectos secundarios, la terapia inmunosupresora convencional es insuficiente para controlar la enfermedad y disminuir la morbimortalidad. Se presenta una revisión sobre el uso de anticuerpos monoclonales anti-CD20 de los linfocitos B (rituximab), para el manejo del pénfigo vulgar resistente y con mala respuesta a múltiples tratamientos convencionales a altas dosis y por periodos prolongados.

Hemangiomatosis neonatal benigna / Benign neonatal hemangiomatosis

La hemangiomatosis neonatal benigna es una rara enfermedad caracterizada por múltiples hemangiomas que se presentan exclusivamente en la piel, en contraste con la hemangiomatosis neonatal difusa que cursa con hemangiomas cutáneos y viscerales y es de mal pronóstico. Se describe a una lactante con hemangiomatosis neonatal benigna sin lesiones viscerales.

Microinjection of an antibody against the cysteine-protease involved in male chromatin remodeling blocks the development of sea urchin embryos at the initial cell cycle.

We reported recently that the inhibition of cysteine-proteases with E-64-d disturbs DNA replication and prevents mitosis of the early sea urchin embryo. Since E-64-d is a rather general inhibitor of thiol-proteases, to specifically target the cysteine-protease previously identified in our laboratory as the enzyme involved in male chromatin remodeling after fertilization, we injected antibodies against the N-terminal sequence of this protease that were able to inhibit the activity of this enzyme in vitro. We found that injection of these antibodies disrupts the initial zygotic cell cycle. As shown in this report in injected zygotes a severe inhibition of DNA replication was observed, the mitotic spindle was not correctly bipolarized the embryonic development was aborted at the initial cleavage division. Consequently, the injection of these antibodies mimics perfectly the effects previously described for E-64-d, indicating that the effects of this inhibitor rely mainly on the inhibition of the cysteine-protease involved in male chromatin remodeling after fertilization. These results further support the crucial role of this protease in early embryonic development.

Cysteine-protease involved in male chromatin remodeling after fertilization co-localizes with alpha-tubulin at mitosis.

We postulated an essential role for a cysteine-protease in sea urchins sperm histones degradation which follows fertilization. We now report the purification of this enzyme, the determination of its N-terminal amino acid sequence and the localization of the protein with antibodies generated against this amino-terminal peptide. The immunofluorescence data confirmed the presence of this enzyme in the nucleus of unfertilized eggs. After fertilization labeling is observed both in female and male pronuclei suggesting a rapid recruitment of the enzyme to the male pronuclei. Interestingly, we have found that this cysteine-protease persists in the nucleus of the zygotes during S phase of the cell cycle and co-localizes with alpha-tubulin that organizes the mitotic spindle during the initial embryonic cell division.

Remodeling of sperm chromatin after fertilization involves nucleosomes formed by sperm histones H2A and H2B and two CS histone variants.

The composition of nucleosomes at an intermediate stage of male pronucleus formation was determined in sea urchins. Nucleosomes were isolated from zygotes harvested 10 min post-insemination, whole nucleoprotein particles were obtained from nucleus by nuclease digestion, and nucleosomes were subsequently purified by a sucrose gradient fractionation. The nucleosomes derived from male pronucleus were separated from those derived from female pronucleus by immunoadsorption to antibodies against sperm specific histones (anti-SpH) covalently bound to Sepharose 4B (anti-SpH-Sepharose). The immunoadsorbed nucleosomes were eluted, and the histones were analyzed by Western blots. Sperm histones (SpH) or alternatively, the histones from unfertilized eggs (CS histone variants), were identified with antibodies directed against each set of histones. It was found that these nucleosomes are organized by a core formed by sperm histones H2A and H2B combined with two major CS histone variants. Such a hybrid histone core interacts with DNA fragments of approximately 100 bp. It was also found that these atypical nucleosome cores are subsequently organized in a chromatin fiber that exhibits periodic nuclease hypersensitive sites determined by DNA fragments of 500 bp of DNA. It was found that these nucleoprotein particles were organized primarily by the hybrid nucleosomes described above. We postulate that this unique chromatin organization defines an intermediate stage of male chromatin remodeling after fertilization.