Abscisic Acid: A Potential Secreted Effector Synthesized by Phytophagous Insects for Host-Plant Manipulation.

Abscisic acid (ABA) is an isoprenoid-derived plant signaling molecule involved in a wide variety of plant processes, including facets of growth and development as well as responses to abiotic and biotic stress. ABA had previously been reported in a wide variety of animals, including insects and humans. We used high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-(ESI)-MS/MS) to examine concentrations of ABA in 17 species of phytophagous insects, including gall- and non-gall-inducing species from all insect orders with species known to induce plant galls: Thysanoptera, Hemiptera, Lepidoptera, Coleoptera, Diptera, and Hymenoptera. We found ABA in insect species in all six orders, in both gall-inducing and non-gall-inducing species, with no tendency for gall-inducing insects to have higher concentrations. The concentrations of ABA in insects often markedly exceeded those typically found in plants, suggesting it is highly improbable that insects obtain all their ABA from their host plant via consumption and sequestration. As a follow-up, we used immunohistochemistry to determine that ABA localizes to the salivary glands in the larvae of the gall-inducing Eurosta solidaginis (Diptera: Tephritidae). The high concentrations of ABA, combined with its localization to salivary glands, suggest that insects are synthesizing and secreting ABA to manipulate their host plants. The pervasiveness of ABA among both gall- and non-gall-inducing insects and our current knowledge of the role of ABA in plant processes suggest that insects are using ABA to manipulate source-sink mechanisms of nutrient allocation or to suppress host-plant defenses. ABA joins the triumvirate of phytohormones, along with cytokinins (CKs) and indole-3-acetic acid (IAA), that are abundant, widespread, and localized to glandular organs in insects and used to manipulate host plants.

Determination of a guidance value for the communication of individual-level biomonitoring data for urinary arsenic.

BACKGROUND: Available guidance values to interpret individual-level biomonitoring data (ILBD) for the sum of urinary inorganic-related arsenic species (SUIAS) are generally based on population statistical descriptors and not on a predetermined exposure level that should not be exceeded. The objective of this study was thus to propose a range of SUIAS concentrations, reflecting an exposure corresponding to WHO's provisional guideline value (PGV) for arsenic in drinking water (10 µg/L), within which an exposure-based biomonitoring guidance value can be identified. METHOD A comprehensive literature review was carried out in order to identify studies that were relevant to the determination of a guidance value. Drinking water arsenic exposure and urinary biomonitoring concentrations obtained from selected studies were used to conduct a structural equation modeling meta-analysis, from which regression coefficients were obtained to derive an interpretative guidance range. RESULTS Individuals exposed to the arsenic background level comparable to North American and European countries and to a water source contaminated at the WHO's PGV, would have, on average, urinary SUIAS between 9 and 20 µg/L, with the most probable value being 15 µg/L. To address the associated uncertainty, the final guidance value selection within this range may be based on a targeted sensitivity and specificity towards detecting overexposed individuals. Indeed, spans of sensitivity of 60-82%, and of specificity of 58-85%, were estimated for the proposed range based on drinking water exposure raw data from the literature. CONCLUSION The range of guidance values obtained appears suitable for interpreting and communicating ILBD in any population biomonitoring studies in which background exposure is comparable to the North American and European context. Before selecting a single value within the proposed range, it will be important for Public Health officials to assess the possible consequences of this selection on the management and communication of the biomonitoring results.

Stomata-mediated interactions between plants, herbivores, and the environment.

Stomata play a central role in plant responses to abiotic and biotic stresses. Existing knowledge regarding the roles of stomata in plant stress is centered on abiotic stresses and plant-pathogen interactions, but how stomata influence plant-herbivore interactions remains largely unclear. Here, we summarize the functions of stomata in plant-insect interactions and highlight recent discoveries of how herbivores manipulate plant stomata. Because stomata are linked to interrelated physiological processes in plants, herbivory-induced changes in stomatal dynamics might have cellular, organismic, and/or even community-level impacts. We summarize our current understanding of how stomata mediate plant responses to herbivory and environmental stimuli, propose how herbivores may influence these responses, and identify key knowledge gaps in plant-herbivore interactions.

The Localization of Phytohormones within the Gall-inducing Insect Eurosta solidaginis (Diptera: Tephritidae).

The phytohormone production hypothesis suggests that organisms, including insects, induce galls by producing and secreting plant growth hormones. Auxins and cytokinins are classes of phytohormones that induce cell growth and cell division, which could contribute to the plant tissue proliferation which constitutes the covering gall. Bacteria, symbiotic with insects, may also play a part in gall induction by insects through the synthesis of phytohormones or other effectors. Past studies have shown that concentrations of cytokinins and auxins in gall-inducing insects are higher than in their host plants. However, these analyses have involved whole-body extractions. Using immunolocalization of cytokinin and auxin, in the gall inducing stage of Eurosta solidaginis, we found both phytohormones to localize almost exclusively to the salivary glands. Co-localization of phytohormone label with a nucleic acid stain in the salivary glands revealed the absence of Wolbachia sp., the bacterial symbiont of E. solidaginis, which suggests that phytohormone production is symbiont independent. Our findings are consistent with the hypothesis that phytohormones are synthesized in and secreted from the salivary glands of E. solidaginis into host-plant tissues for the purpose of manipulating the host plant.

Multichromosomal structure and foreign tracts in the Ombrophytum subterraneum (Balanophoraceae) mitochondrial genome.

Horizontal gene transfer (HGT) is frequent in parasitic plant mitochondria as a result of vascular connections established in host-parasite relationships. Recent studies of the holoparasitic plant Lophophytum mirabile (Balanophoraceae) revealed the unprecedented acquisition of a large amount of mitochondrial sequences from its legume host. We focused on a close relative, the generalist holoparasite Ombrophytum subterraneum, to examine the incidence of HGT events in the mitochondrial genome (mtDNA). The mtDNA of O. subterraneum assembles into 54 circular chromosomes, only 34 of which contain the 51 full-length coding regions. Numerous foreign tracts (totaling almost 100 kb, ~ 14% of the mtDNA), including 12 intact genes, were acquired by HGT from the Asteraceae hosts. Nine chromosomes concentrate most of those regions and eight are almost entirely foreign. Native homologs of each foreign gene coexist in the mtDNA and are potentially functional. A large proportion of shorter regions were related to the Fabaceae (a total of ~ 110 kb, 15.4%), some of which were shared with L. mirabile. We also found evidence of foreign sequences donated by angiosperm lineages not reported as hosts (Apocynaceae, Euphorbiaceae, Lamiaceae, and Malvales). We propose an evolutionary hypothesis that involves ancient transfers from legume hosts in the common ancestor of Ombrophytum and Lophophytum followed by more recent transfer events in L. mirabile. Besides, the O. subterraneum mtDNA was also subjected to additional HGT events from diverse angiosperm lineages, including large and recent transfers from the Asteraceae, and also from Lamiaceae.

Duplicación intestinal en la primera porción del duodeno en neonato / Intestinal Duplication in the First Portion of the Neonatal Duodenum

RESUMEN Se denomina duplicación intestinal a un grupo de malformaciones congénitas de la vía digestiva, de estructuras diverticulares, quísticas o tubulares, que presentan paredes de músculo liso como las del intestino y un revestimiento mucoso de tipo gastrointestinal. Se localiza en cualquier segmento del tubo digestivo, desde la boca hasta el ano. La zona más afectada es el íleon y constituye la causa más frecuente de masa abdominal en el periodo neonatal. El diagnóstico puede ser prenatal a través, de ecografía o resonancia. En el periodo posnatal es la clínica la que establece los indicios para realizar exámenes complementarios, que pueden ir desde ecografía hasta estudios con Tecnecio 99. En la porción duodenal esta enfermedad representa el 5 por ciento de todas las duplicaciones intestinales. La descripción de casos en la primera porción es excepcional, por lo que la consideramos para tener en cuenta como diagnóstico diferencial en las enfermedades tumorales neonatales de origen abdominal(AU)

ABSTRACT Intestinal duplication defines a group of congenital malformations of the digestive tract, of diverticular, cystic or tubular structures, which have smooth muscle walls such as those of the intestine and a gastrointestinal-type mucous lining. It is located in any segment of the digestive tract, from the mouth to the anus. The most affected area is the ileum, while the condition constitutes the most frequent cause of abdominal mass in the neonatal period. The diagnosis can be prenatal through either ultrasound or resonance. In the postnatal period, the clinical indications establish, based on the signs, whether complementary tests are required, which can range from ultrasound to studies with technetium-99. In the duodenal portion, this disease represents 5 percent of all intestinal duplications. The description of cases in the first portion is exceptional, which is the reason why we consider it as a differential diagnosis in neonatal tumor diseases of abdominal origin(AU)

Tumores Benignos de Ovario en la edad Pediátrica y Adolescencia / Benign Ovarian Tumors in Pediatric and Adolescence

Introducción: Los tumores ováricos son raros en la edad pediátrica y representan del 1 al 5% de los tumores infantiles. El objetivo del presente trabajo es conocer cuáles son los tumores de ovario más frecuentes en nuestro medio en niñas y adolescentes en un centro oncológico de la ciudad de Guayaquil-Ecuador. Métodos: El presente estudio es descriptivo y retrospectivo, en la que se realiza una revisión de registros de niñas y adolescentes con diagnóstico de tumores de ovario, en el Instituto Oncológico Nacional "Dr. Juan Tanca Marengo" en el período de enero 2015 a mayo del 2017. Las variables registradas fueron edad, diagnóstico ecográfico, diagnostico histopatológico, ovario afecto, características clínicas, salpingectomía, marcadores tumorales. Se utiliza estadística descriptiva. Resultados: Ingresaron al estudio 32 pacientes de 12.7 años promedio. El ovario más afectado fue el derecho con una relación 2.2: 1 y en 9 % fue bilateral. La histología reportada de los quistes serosos fueron el 21 % quiste folicular y 18.5 % por quiste lúteo. Los quistes simples representaron el 15.25 %, el cistoadenoma y el teratoma maduro con un 9 %, el quiste dermoide y le endometrioma con un 3 %. El dolor fue el síntoma más llamativo estado como síntoma único en 65.5 %. El 18.75 % terminó en anexectomía con ooforectomía por extensión del quiste, el 81.25 % solo requirió quistectomía. Conclusión: La histología reportada en esta serie de tumores benignos de ovario, los quistes serosos foliculares fueron los más prevalentes, seguidos de los quistes lúteos. El dolor pélvico fue el síntoma más llamativo. La mayoría de los casos requirieron quistectomía y el 19 % requirió adicionalmente ooforectomía.

Introduction: Ovarian tumors are rare in pediatric age and represent 1 to 5% of childhood tumors. The objective of this work is to know which are the most frequent ovarian tumors in our environment in girls and adolescents in an oncological center of the city of Guayaquil-Ecuador. Methods: The present study is descriptive and retrospective, in which a review of records of girls and adolescents diagnosed with ovarian tumors is performed, at the National Oncology Institute "Dr. Juan Tanca Marengo" in the period from January 2015 to May 2017. The variables recorded were age, ultrasound diagnosis, histopathological diagnosis, affected ovary, clinical characteristics, salpingectomy, tumor markers. Descriptive statistics are used. Results: 32 patients with an average age of 12.7 entered the study. The most affected ovary was the right one with a 2.2: 1 ratio and in 9% it was bilateral. The reported histology of serous cysts were 21% follicular cyst and 18.5% by luteal cyst. Simple cysts accounted for 15.25%, cystadenoma and mature teratoma with 9%, dermoid cyst and endometrioma with 3%. Pain was the most striking condition as a single symptom in 65.5%. 18.75% ended up in anexectomy with oophorectomy due to cyst extension, 81.25% only required a cystectomy. Conclusion: The histology reported in this series of benign ovarian tumors, follicular serous cysts were the most prevalent, followed by luteal cysts. Pelvic pain was the most striking symptom. The majority of cases required a cystectomy and 19% additionally required oophorectomy.