Bedbugs evolved before their bat hosts and did not co-speciate with ancient humans

All 100+ bedbug species (Cimicidae) are obligate blood-sucking parasites [1, 2]. In general, blood sucking (hematophagy) is thought to have evolved in generalist feeders adventitiously taking blood meals [3, 4], but those cimicid taxa currently considered ancestral are putative host specialists [1, 5]. Bats are believed to be the ancestral hosts of cimicids [1], but a cimicid fossil [6] predates the oldest known bat fossil [7] by >30 million years (Ma). The bedbugs that parasitize humans [1, 8] are host generalists, so their evolution from specialist ancestors is incompatible with the "resource efficiency" hypothesis and only partially consistent with the "oscillation" hypothesis [9-16]. Because quantifying host shift frequencies of hematophagous specialists and generalists may help to predict host associations when vertebrate ranges expand by climate change [17], livestock, and pet trade in general and because of the previously proposed role of human pre-history in parasite speciation [18-20], we constructed a fossil-dated, molecular phylogeny of the Cimicidae. This phylogeny places ancestral Cimicidae to 115 mya as hematophagous specialists with lineages that later frequently populated bat and bird lineages. We also found that the clades, including the two major current urban pests, Cimex lectularius and C. hemipterus, separated 47 mya, rejecting the notion that the evolutionary trajectories of Homo caused their divergence [18-21]

Limitations of Tc99m-MIBI-SPECT Imaging Scans in Persistent Primary Hyperparathyroidism

In primary hyperparathyroidism (PHPT) the predictive value of technetium 99m sestamibi single emission computed tomography (Tc99m-MIBI-SPECT) for localizing pathological parathyroid glands before a first parathyroidectomy (PTx) is 83-100%. Data are scarce in patients undergoing reoperative parathyroidectomy for persistent hyperparathyroidism. The aim of the present study was to determine the value of Tc99m-MIBI-SPECT in localizing residual hyperactive parathyroid tissue in patients with persistent primary hyperparathyroidism (PHPT) after initial excision of one or more pathological glands. We retrospectively evaluated the localizing accuracy of Tc99m-MIBI-SPECT scans in 19 consecutive patients with persistent PHPT who had a scan before reoperative parathyroidectomy. We used as controls 23 patients with sporadic PHPT who had a scan before initial surgery. In patients with persistent PHPT, Tc99m-MIBI-SPECT accurately localized a pathological parathyroid gland in 33% of cases before reoperative parathyroidectomy, compared to 61% before first PTx for sporadic PHPT. The Tc99m-MIBI-SPECT scan accurately localized intra-thyroidal glands in 2 of 7 cases and a mediastinal gland in 1 of 3 cases either before initial or reoperative parathyroidectomy. Our data suggest that the accuracy of Tc99m-MIBI-SPECT in localizing residual hyperactive glands is significantly lower before reoperative parathyroidectomy for persistent PHPT than before initial surgery for sporadic PHPT. These findings should be taken in consideration in the preoperative workup of patients with persistent primary hyperparathyroidis

Prevalencia de esofagitis eosinofílica: estudio multicéntrico en población pediátrica evaluada en 36 centros de gastroenterología de América Latina

Introducción y objetivo: La esofagitis eosinofílica es una enfermedad crónica, mediada inmunológicamente, descrita en series y publicaciones alrededor del mundo. En los últimos 20 años diversos estudios han intentado evaluar la incidencia y prevalencia de la enfermedad. El objetivo del presente trabajo es estimar la prevalencia de esofagitis eosinofílica en un grupo de niños atendidos en 36 centros de gastroenterología pediátrica de 10 países latinoamericanos. Materiales y métodos: A través de un protocolo multicéntrico, observacional y transversal se estimó la prevalencia de período de esofagitis eosinofílica entre los niños atendidos en consulta externa y sometidos a endoscopia superior diagnóstica por cualquier motivo en 36 centros de 10 países latinoamericanos durante un período de 3 meses. Resultados: Entre abril y junio de 2016 108 casos de esofagitis eosinofílica fueron evaluados. Asimismo, un promedio de 29,253 consultas ambulatorias y 4,152 endoscopias superiores de carácter diagnóstico fueron realizadas en los 36 centros participantes. La tasa de prevalencia de esofagitis eosinofílica en la población estudiada (n = 29,253) fue de 3,69 casos × 1,000 (IC 95%: 3.04 a 4.44) y entre los niños sometidos a endoscopia superior de rutina (n = 4,152) fue de 26 x 1,000 (IC 95%: 22.6 a 29.4). Conclusión: La tasa general de prevalencia de período de esofagitis eosinofílica en un grupo de niños evaluados en 36 centros latinoamericanos de gastroenterología pediátrica resultó de 3,69 × 1,000, y entre aquellos sometidos a endoscopia fue de 26 × 1,000. La prevalencia mostró una importante variabilidad entre los países y centros participantes. Este es el primer estudio de prevalencia de esofagitis eosinofílica pediátrica en Latinoamérica. Abstract: Introduction and objective: Eosinophilic esophagitis is a chronic, immune-mediated disease described in case series and publications worldwide. Over the past twenty years, the authors of different studies have attempted to evaluate its incidence and prevalence. The objetive of the present study was to estimate the prevalence of eosinophilic esophagitis in a group of children seen at 36 pediatric gastroenterology centers in ten Latin American countries. Materials and methods: A multicenter, observational, and cross-sectional study was conducted that estimated the period prevalence of eosinophilic esophagitis in children seen at outpatient consultation and that underwent diagnostic upper gastrointestinal endoscopy for any indication at 36 centers in 10 Latin American countries, within a 3-month time frame. Results: Between April and June 2016, 108 cases of eosinophilic esophagitis were evaluated. Likewise, an average of 29,253 outpatient consultations and 4,152 diagnostic upper gastrointestinal endoscopies were carried out at the 36 participating centers. The period prevalence of eosinophilic esophagitis in the population studied (n = 29,253) was 3.69 cases × 1,000 (95% CI: 3.04 to 4.44), and among the children that underwent routine upper gastrointestinal endoscopy (n = 4,152), it was 26 x 1,000 (95% CI: 22.6 to 29.4). Conclusions: The general period prevalence of eosinophilic esophagitis in a group of children evaluated at 36 Latin American pediatric gastroenterology centers was 3.69 × 1,000, and in the children that underwent endoscopy, it was 26 × 1,000. There was important prevalence variability between the participating countries and centers. The present analysis is the first study conducted on the prevalence of pediatric eosinophilic esophagitis in Latin America. Palabras clave: Esofagitis, Eosinofílica, Niños, Prevalencia, Latinoamérica, Keywords: Esophagitis, Eosinophilic, Children, Prevalence, Latin Americ

Root-emitted volatile organic compounds: can they mediate belowground plant-plant interactions?

peer reviewedBackground Aboveground, plants release volatile organic compounds (VOCs) that act as chemical signals between neighbouring plants. It is now well documented that VOCs emitted by the roots in the plant rhizosphere also play important ecological roles in the soil ecosystem, notably in plant defence because they are involved in interactions between plants, phytophagous pests and organisms of the third trophic level. The roles played by root-emitted VOCs in between- and within-plant signalling, however, are still poorly documented in the scientific literature. Scope Given that (1) plants release volatile cues mediating plant-plant interactions aboveground, (2) roots can detect the chemical signals originating from their neighbours, and (3) roots release VOCs involved in biotic interactions belowground, the aim of this paper is to discuss the roles of VOCs in between- and within-plant signalling belowground. We also highlight the technical challenges associated with the analysis of root-emitted VOCs and the design of experiments targeting volatile-mediated root-root interactions. Conclusions We conclude that root-root interactions mediated by volatile cues deserve more research attention and that both the analytical tools and methods developed to study the ecological roles played by VOCs in interplant signalling aboveground can be adapted to focus on the roles played by root-emitted VOCs in between- and within-plant signalling