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1.
J Invertebr Pathol ; 203: 108070, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38311231

RESUMEN

Consistent efficacy is required for entomopathogenic nematodes to gain wider adoption as biocontrol agents. Recently, we demonstrated that when exposed to nematode pheromone blends, entomopathogenic nematodes showed increased dispersal, infectivity, and efficacy under laboratory and greenhouse conditions. Prior to this study, the impact of entomopathogenic nematode-pheromone combinations on field efficacy had yet to be studied. Steinernema feltiae is a commercially available entomopathogenic nematode that has been shown to increase mortality in insect pests such as the pecan weevil Curculio caryae. In this study, the pecan weevil was used as a model system to evaluate changes in S. feltiae efficacy when treated with a partially purified ascaroside pheromone blend. Following exposure to the pheromone blend, the efficacy of S. feltiae significantly increased as measured with decreased C. caryae survival despite unfavorable environmental conditions. The results of this study highlight a potential new avenue for using entomopathogenic nematodes in field conditions. With increased efficacy, using entomopathogenic nematodes will reduce reliance on conventional management methods in pecan production, translating into more environmentally acceptable practices.


Asunto(s)
Carya , Rabdítidos , Gorgojos , Animales , Feromonas/farmacología , Control Biológico de Vectores/métodos
2.
J Nematol ; 56(1): 20240002, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38495935

RESUMEN

Maintenance of an aggregated population structure implies within-species communication. In mixed-species environments, species-specific aggregations may reduce interspecific competition and promote coexistence. We studied whether movement and aggregation behavior of three entomopathogenic nematode species changed when isolated, as compared to mixed-species arenas. Movement and aggregation of Steinernema carpocapsae, S. feltiae and S. glaseri were assessed in sand. Each species demonstrated significant aggregation when alone. Mixed-species trials involved adding two species of nematodes, either combined in the center of the arena or at separate corners. While individual species became less aggregated than in single-species conditions when co-applied in the same location, they became more aggregated when applied in separate corners. This increased aggregation in separate-corner trials occurred even though the nematodes moved just as far when mixed together as they did when alone. These findings suggest that maintenance of multiple species within the same habitat is driven, at least in part, by species-specific signals that promote conspecific aggregation, and when the species are mixed (as occurs in some commercial formulations involving multiple EPN species), these signaling mechanisms are muddled.

3.
J Nematol ; 532021.
Artículo en Inglés | MEDLINE | ID: mdl-34957409

RESUMEN

We used a phylogenetic framework to examine the relationship between entomopathogenic nematode (EPN) vertical dispersal and infectivity when EPNs are exposed to a mixture of compounds found in late-stage EPN-infected insect cadavers. EPNs from five phylogenetically close and distant species (Heterorhabditis bacteriophora, H. georgiana, H. megidis, H. indica and Steinernema feltiae) were exposed to cadaver macerate produced by their own species' infection and by H. bacteriophora infected hosts. We found that only three of the five species (H. bacteriophora, H. indica and S. feltiae) responded to exposure to their own macerate by increasing rates of dispersal. When we exposed all five species to a H. bacteriophora infected host macerate, we found that only H. bacteriophora responded by increasing dispersal, and that the most distantly related species (S. feltiae) essentially halted dispersal. These findings suggest that (1) responses to cadaver macerate vary, and (2) there may be a relationship between inherent dispersal rates and sensitivity to macerate exposure, as the most rapidly dispersing species (H. megidis) showed no response to macerate exposure.

4.
Surg Radiol Anat ; 42(2): 171-177, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31446447

RESUMEN

PURPOSE: Several skull-base foramina including foramen meningo-orbitale, craniopharyngeal canals, canaliculus innominatus, foramen vesalius, palatovaginal canals, and canalis basalis medianus are visible on cone-beam computed tomographs. A good understanding of the anatomical variants of these foramina is important to accurately diagnose fractures, understand the paths that infections may take, and identify associated anomalies. We used cone-beam computed tomography to measure the incidences of skull-base foramen variants in a normal population. METHODS: A total of 350 subjects (200 females, 150 males, 6-30 years of age) were included. The prevalences of foramen meningo-orbitale, craniopharyngeal canals, canaliculus innominatus, foramina vesalius, palatovaginal canals, and canalis basalis medianus were evaluated by age and gender. RESULTS: Subject age ranged from 6 to 30 years (mean age ± SD = 15.1 ± 4.08). Foramen meningo-orbitale, craniopharyngeal canals, canaliculus innominatus, foramen vesalius, palatovaginal canal, and canalis basalis medianus were observed in 51 (14.6%), 19 (5.4%), 60 (17.1%), 145 (41.1%), 34 (9.7%), and 15 (4.3%) patients, respectively. CONCLUSIONS: Skull-base foramina are important clinically and radiologically. Imaging of such variants via cone-beam computed tomography is valuable for both physicians and patients. Few studies of skull-base foramina have used cone-beam computed tomography. Additional research is required for a fuller understanding of this phenomenon.


Asunto(s)
Variación Anatómica , Tomografía Computarizada de Haz Cónico/estadística & datos numéricos , Base del Cráneo/anomalías , Adolescente , Adulto , Niño , Femenino , Humanos , Incidencia , Masculino , Estudios Retrospectivos , Base del Cráneo/diagnóstico por imagen , Adulto Joven
5.
J Invertebr Pathol ; 164: 38-42, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31034842

RESUMEN

Inconsistency in entomopathogenic nematode (EPN) efficacy is still one of the biggest challenges for the wider adoption of EPNs as biocontrol agents. Previous studies demonstrated that extracts from EPN-infected hosts enhance dispersal and efficacy, two key factors in success of EPNs. Some active components in the insect host cadavers responsible for dispersal, ascarosides, have been identified as nematode pheromones. We hypothesized that pheromone extracts increase dispersal of EPN infective juveniles (IJs) leading to increased efficacy. First, we determined whether pheromone extracts improved IJ movement/dispersal in soil columns baited with Tenebrio molitor larvae. We found that pheromone extracts induced higher numbers of Steinernema carpocapsae and Steinernema feltiae IJs to move towards T. molitor larvae in the bottom of the column compared to IJs treated with infected cadaver macerate and water, positive and negative controls, respectively. Furthermore, the number of S. carpocapsae IJs that invaded T. molitor larvae was higher for the pheromone extract treatment than the controls. S. feltiae IJs that were pretreated with pheromone extracts and macerate (positive control) infected T. molitor at the same rate but invasion was superior to IJs that were treated with water. Consistent with the soil column tests, both S. carpocapsae and S. feltiae IJs treated with pheromone extracts performed better in killing larvae of two economically important insect larvae, pecan weevil, Curculio caryae, and black soldier fly, Hermetia illucens, in greenhouse tests compared to IJs treated with water. We demonstrated pheromone-mediated behavioral manipulation of a biological control agent to enhance pest control potential. Conceivably, nematodes can be exposed to efficacy-enhancing pheromones prior to field application.


Asunto(s)
Feromonas , Infecciones por Rhabditida/parasitología , Rabdítidos , Animales , Bioensayo , Agentes de Control Biológico , Dípteros/parasitología , Larva/parasitología , Mariposas Nocturnas/parasitología , Control Biológico de Vectores , Rabdítidos/patogenicidad , Suelo/parasitología , Gorgojos/parasitología
6.
J Invertebr Pathol ; 159: 141-144, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30336144

RESUMEN

Vertical dispersal and infectivity of the infective juveniles (IJs) of three entomopathogenic nematodes (EPNs), Steinernema carpocapsae, S. feltiae, and Heterorhabditis bacteriophora, were tested in the presence or absence of cadaver macerate of nematode-infected Galleria mellonella. Infected host macerate applied on the top of column surface induced higher numbers of IJs to move to the bottom of the column for all three species, indicating a dispersal-enhancing effect of host cadaver on IJs. Among the three EPNs, H. bacteriophora was the most responsive to host macerate, followed by S. feltiae, and S. carpocapsae was the least. Also, more IJs of H. bacteriophora invaded Tenebrio molitor hosts at the bottom of soil columns in the presence of host macerate compared with the treatment without cadaver macerate. These findings suggest enhanced dispersal and/or infectivity of all three EPNs may be leveraged toward superior biocontrol efficacy.


Asunto(s)
Interacciones Huésped-Parásitos/fisiología , Mariposas Nocturnas/parasitología , Nematodos/parasitología , Control Biológico de Vectores/métodos , Animales , Microbiología del Suelo
7.
J Invertebr Pathol ; 151: 137-143, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-29158014

RESUMEN

To exploit resources, animals implement various foraging behaviors to increase their fitness. Entomopathogenic nematodes are obligate parasites of insects in nature. In previous studies, entomopathogenic nematodes were reported to exhibit group movement behavior in the presence and absence of insect hosts. However, it was not determined if group movement is continuous or temporal. For example, nematode movement behavior upon emergence from the host might start out in an independent fashion prior to aggregation, or group movement may be exhibited continuously. In the present study, we explored the propensity for innate group movement behavior of two insect parasitic nematodes in two families and genera: Heterorhabditis indica and Steinernema carpocapsae. We hypothesized the nematode populations would initially move independently from their origin and then come together for group movement. Movement patterns were investigated in sand when nematodes were applied in aqueous suspension (via filter paper) to a specific locus or when the nematodes emerged naturally from infected insect hosts. To compare nematode movement behavior over time and space, nematode dispersal was monitored at three distances (2.5, 4.5 and 8.0 cm) from the center (origin) and at two different time periods, 2 days and 3 days after nematode addition. We discovered that nematode dispersal continuously exhibited an aggregative pattern (independent movement was not observed). Results from both nematode species as well as the host-cadaver and filter paper (aqueous nematode suspension) application methods indicated a continuous aggregative pattern. The discovery of continuous aggregative movement patterns in steinernematid and heterorhabditid nematodes elucidates further the complexity of their foraging behavior and may serve as basis for exploring foraging behavior in other host-parasite systems.


Asunto(s)
Conducta Animal/fisiología , Movimiento/fisiología , Rabdítidos/fisiología , Animales
8.
Proc Natl Acad Sci U S A ; 112(36): 11407-12, 2015 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-26305953

RESUMEN

Plant damage promotes the interaction of lipoxygenases (LOXs) with fatty acids yielding 9-hydroperoxides, 13-hydroperoxides, and complex arrays of oxylipins. The action of 13-LOX on linolenic acid enables production of 12-oxo-phytodienoic acid (12-OPDA) and its downstream products, termed "jasmonates." As signals, jasmonates have related yet distinct roles in the regulation of plant resistance against insect and pathogen attack. A similar pathway involving 9-LOX activity on linolenic and linoleic acid leads to the 12-OPDA positional isomer, 10-oxo-11-phytodienoic acid (10-OPDA) and 10-oxo-11-phytoenoic acid (10-OPEA), respectively; however, physiological roles for 9-LOX cyclopentenones have remained unclear. In developing maize (Zea mays) leaves, southern leaf blight (Cochliobolus heterostrophus) infection results in dying necrotic tissue and the localized accumulation of 10-OPEA, 10-OPDA, and a series of related 14- and 12-carbon metabolites, collectively termed "death acids." 10-OPEA accumulation becomes wound inducible within fungal-infected tissues and at physiologically relevant concentrations acts as a phytoalexin by suppressing the growth of fungi and herbivores including Aspergillus flavus, Fusarium verticillioides, and Helicoverpa zea. Unlike previously established maize phytoalexins, 10-OPEA and 10-OPDA display significant phytotoxicity. Both 12-OPDA and 10-OPEA promote the transcription of defense genes encoding glutathione S transferases, cytochrome P450s, and pathogenesis-related proteins. In contrast, 10-OPEA only weakly promotes the accumulation of multiple protease inhibitor transcripts. Consistent with a role in dying tissue, 10-OPEA application promotes cysteine protease activation and cell death, which is inhibited by overexpression of the cysteine protease inhibitor maize cystatin-9. Unlike jasmonates, functions for 10-OPEA and associated death acids are consistent with specialized roles in local defense reactions.


Asunto(s)
Ciclopentanos/metabolismo , Lipooxigenasa/metabolismo , Proteínas de Plantas/metabolismo , Sesquiterpenos/metabolismo , Zea mays/metabolismo , Ascomicetos/fisiología , Ciclopentanos/química , Ciclopentanos/farmacología , Cistatinas/genética , Cistatinas/metabolismo , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Interacciones Huésped-Patógeno , Immunoblotting , Lipooxigenasa/genética , Espectroscopía de Resonancia Magnética , Estructura Molecular , Análisis de Secuencia por Matrices de Oligonucleótidos , Oxilipinas/química , Oxilipinas/metabolismo , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Hojas de la Planta/genética , Hojas de la Planta/metabolismo , Hojas de la Planta/microbiología , Proteínas de Plantas/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Sesquiterpenos/química , Sesquiterpenos/farmacología , Zea mays/genética , Zea mays/microbiología , Fitoalexinas
9.
Int Ophthalmol ; 38(5): 1915-1922, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28780617

RESUMEN

PURPOSE: To investigate the effect of Helicobacter pylori (H. pylori) infection on choroidal thickness (CT) and retinal nerve fiber layer thickness (RNFLT). METHODS: The study included 25 patients with H. pylori infection and 25 healthy individuals as the control group. Helicobacter pylori patients were classified as the pre-treatment (Group 1; n: 25) and the post-treatment (Group 2; n: 25). RNFLT and CT were measured before and after treatment of H. pylori infection, using enhanced depth imaging (EDI) spectral-domain optical coherence tomography (Spectralis, Heidelberg Engineering, Heidelberg, Germany). The axial length and intraocular pressure were also measured. RESULTS: The mean subfoveal CT was 320.96 ± 29.15 µm in Group 1 and 287.48 ± 49.17 in the control group (p = 0.007), while the mean subfoveal CT did not show any difference between Group 2 and the control group (p > 0.05). No statistically significant difference was determined between the H. pylori patients and the control group in respect of RNFLT values (p > 0.05). CONCLUSIONS: CT increases during H. pylori infection and returns to the normal range within 6 weeks of treatment. RNFLT does not show any change during H. pylori infection. The data related to the subfoveal CT may be useful in understanding the pathogenesis of central serous chorioretinopathy developing in H. pylori patients.


Asunto(s)
Coroides/patología , Infecciones por Helicobacter/diagnóstico , Helicobacter pylori/aislamiento & purificación , Fibras Nerviosas/patología , Células Ganglionares de la Retina/patología , Tomografía de Coherencia Óptica/métodos , Adulto , Coriorretinopatía Serosa Central/etiología , Coriorretinopatía Serosa Central/patología , Femenino , Mucosa Gástrica/microbiología , Infecciones por Helicobacter/complicaciones , Infecciones por Helicobacter/microbiología , Humanos , Masculino , Persona de Mediana Edad , Disco Óptico/patología , Estudios Prospectivos , Adulto Joven
10.
Proc Natl Acad Sci U S A ; 109(51): 20949-54, 2012 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-23213209

RESUMEN

Nematodes use an extensive chemical language based on glycosides of the dideoxysugar ascarylose for developmental regulation (dauer formation), male sex attraction, aggregation, and dispersal. However, no examples of a female- or hermaphrodite-specific sex attractant have been identified to date. In this study, we investigated the pheromone system of the gonochoristic sour paste nematode Panagrellus redivivus, which produces sex-specific attractants of the opposite sex. Activity-guided fractionation of the P. redivivus exometabolome revealed that males are strongly attracted to ascr#1 (also known as daumone), an ascaroside previously identified from Caenorhabditis elegans hermaphrodites. Female P. redivivus are repelled by high concentrations of ascr#1 but are specifically attracted to a previously unknown ascaroside that we named dhas#18, a dihydroxy derivative of the known ascr#18 and an ascaroside that features extensive functionalization of the lipid-derived side chain. Targeted profiling of the P. redivivus exometabolome revealed several additional ascarosides that did not induce strong chemotaxis. We show that P. redivivus females, but not males, produce the male-attracting ascr#1, whereas males, but not females, produce the female-attracting dhas#18. These results show that ascaroside biosynthesis in P. redivivus is highly sex-specific. Furthermore, the extensive side chain functionalization in dhas#18, which is reminiscent of polyketide-derived natural products, indicates unanticipated biosynthetic capabilities in nematodes.


Asunto(s)
Nematodos/metabolismo , Atractivos Sexuales/metabolismo , Animales , Quimiotaxis/efectos de los fármacos , Femenino , Espectroscopía de Resonancia Magnética/métodos , Masculino , Metabolómica , Modelos Biológicos , Modelos Químicos , Oxígeno/química , Peroxisomas/metabolismo , Feromonas/metabolismo , Conducta Sexual Animal/efectos de los fármacos , Conducta Sexual Animal/fisiología , Transducción de Señal
11.
J Nat Prod ; 77(2): 402-5, 2014 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-24467367

RESUMEN

Methyl farnesoate, [methyl (2E,6E)-3,7,11-trimethyldodeca-2,6,10-trienoate (1)] has not been thought be present in the hemolymph of insects, although it is the immediate biosynthetic precursor of the circulating insect hormone juvenile hormone III (methyl (2E,6E)-10,11-epoxy-3,7,11-trimethyl-2,6-dodecadienoate) (2). Compound 1 was identified from the hemolymph obtained from five orders of insects. Identification of 1 from the American bird grasshopper was facilitated using both electron impact and chemical-ionization GC-MS, GC-FTIR, and 2D NMR techniques. The identifications from other insects were made using GC-MS, and the amounts of all were quantified using LIM-CI-GC-MS. The ratios of 1 and 2 varied in these insects during different developmental stages. The present results underscore the need for further studies on methyl farnesoate (1) as a circulating hormone in insects.


Asunto(s)
Ácidos Grasos Insaturados/aislamiento & purificación , Saltamontes/química , Hemolinfa/química , Sesquiterpenos/aislamiento & purificación , Animales , Ácidos Grasos Insaturados/química , Ácidos Grasos Insaturados/metabolismo , Cromatografía de Gases y Espectrometría de Masas , Saltamontes/metabolismo , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Sesquiterpenos/química , Sesquiterpenos/metabolismo
12.
Nature ; 454(7208): 1115-8, 2008 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-18650807

RESUMEN

In many organisms, population-density sensing and sexual attraction rely on small-molecule-based signalling systems. In the nematode Caenorhabditis elegans, population density is monitored through specific glycosides of the dideoxysugar ascarylose (the 'ascarosides') that promote entry into an alternative larval stage, the non-feeding and highly persistent dauer stage. In addition, adult C. elegans males are attracted to hermaphrodites by a previously unidentified small-molecule signal. Here we show, by means of combinatorial activity-guided fractionation of the C. elegans metabolome, that the mating signal consists of a synergistic blend of three dauer-inducing ascarosides, which we call ascr#2, ascr#3 and ascr#4. This blend of ascarosides acts as a potent male attractant at very low concentrations, whereas at the higher concentrations required for dauer formation the compounds no longer attract males and instead deter hermaphrodites. The ascarosides ascr#2 and ascr#3 carry different, but overlapping, information, as ascr#3 is more potent as a male attractant than ascr#2, whereas ascr#2 is slightly more potent than ascr#3 in promoting dauer formation. We demonstrate that ascr#2, ascr#3 and ascr#4 are strongly synergistic, and that two types of neuron, the amphid single-ciliated sensory neuron type K (ASK) and the male-specific cephalic companion neuron (CEM), are required for male attraction by ascr#3. On the basis of these results, male attraction and dauer formation in C. elegans appear as alternative behavioural responses to a common set of signalling molecules. The ascaroside signalling system thus connects reproductive and developmental pathways and represents a unique example of structure- and concentration-dependent differential activity of signalling molecules.


Asunto(s)
Caenorhabditis elegans/efectos de los fármacos , Caenorhabditis elegans/fisiología , Atractivos Sexuales/metabolismo , Atractivos Sexuales/farmacología , Conducta Sexual Animal/efectos de los fármacos , Animales , Caenorhabditis elegans/crecimiento & desarrollo , Caenorhabditis elegans/metabolismo , Trastornos del Desarrollo Sexual , Escherichia coli/fisiología , Glucolípidos/química , Glucolípidos/aislamiento & purificación , Glucolípidos/metabolismo , Glucolípidos/farmacología , Hexosas/química , Hexosas/aislamiento & purificación , Hexosas/metabolismo , Hexosas/farmacología , Masculino , Neuronas/metabolismo , Densidad de Población , Atractivos Sexuales/química , Atractivos Sexuales/aislamiento & purificación , Conducta Sexual Animal/fisiología
13.
Proc Natl Acad Sci U S A ; 108(13): 5455-60, 2011 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-21402917

RESUMEN

Phytoalexins constitute a broad category of pathogen- and insect-inducible biochemicals that locally protect plant tissues. Because of their agronomic significance, maize and rice have been extensively investigated for their terpenoid-based defenses, which include insect-inducible monoterpene and sesquiterpene volatiles. Rice also produces a complex array of pathogen-inducible diterpenoid phytoalexins. Despite the demonstration of fungal-induced ent-kaur-15-ene production in maize over 30 y ago, the identity of functionally analogous maize diterpenoid phytoalexins has remained elusive. In response to stem attack by the European corn borer (Ostrinia nubilalis) and fungi, we observed the induced accumulation of six ent-kaurane-related diterpenoids, collectively termed kauralexins. Isolation and identification of the predominant Rhizopus microsporus-induced metabolites revealed ent-kaur-19-al-17-oic acid and the unique analog ent-kaur-15-en-19-al-17-oic acid, assigned as kauralexins A3 and B3, respectively. Encoding an ent-copalyl diphosphate synthase, fungal-induced An2 transcript accumulation precedes highly localized kauralexin production, which can eventually exceed 100 µg · g(-1) fresh weight. Pharmacological applications of jasmonic acid and ethylene also synergize the induced accumulation of kauralexins. Occurring at elevated levels in the scutella of all inbred lines examined, kauralexins appear ubiquitous in maize. At concentrations as low as 10 µg · mL(-1), kauralexin B3 significantly inhibited the growth of the opportunistic necrotroph R. microsporus and the causal agent of anthracnose stalk rot, Colletotrichum graminicola. Kauralexins also exhibited significant O. nubilalis antifeedant activity. Our work establishes the presence of diterpenoid defenses in maize and enables a more detailed analysis of their biosynthetic pathways, regulation, and crop defense function.


Asunto(s)
Diterpenos/metabolismo , Sesquiterpenos/metabolismo , Zea mays/química , Zea mays/fisiología , Animales , Antifúngicos/química , Antifúngicos/metabolismo , Colletotrichum/patogenicidad , Diterpenos/química , Insectos/patogenicidad , Insecticidas/química , Insecticidas/metabolismo , Estructura Molecular , Mucormicosis/microbiología , Enfermedades de las Plantas/microbiología , Reguladores del Crecimiento de las Plantas/metabolismo , Rhizopus/patogenicidad , Sesquiterpenos/química , Zea mays/microbiología , Zea mays/parasitología , Fitoalexinas
14.
Microsc Res Tech ; 86(7): 791-802, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37158110

RESUMEN

PURPOSE: The aim of this study is to evaluate the effect of different irrigation activation techniques on the dentin tubules penetration of two different sealers by confocal laser scanning microscope (CLSM). METHODS: A hundred premolar teeth were used in this study. The root canals were shaped and irrigated with 5% NaOCl and 17% EDTA using the following final irrigation activation techniques in each group; Group1: Conventional Syringe Irrigation (CSI), Group2: Passive Ultrasonic Irrigation (PUI), Group3: Apical Negative Pressure (EndoVac), Group4: Er:YAG laser and Group5: Er,Cr:YSGG laser. Then the teeth were separated two subgroups according to sealers (AH-Plus and Totalfill-BC). Horizontal sections were obtained at 2, 5, 8 mm distance of apex. Images were obtained with CLSM and the penetration areas of sealers were calculated with four different dentin tubule penetration assessment techniques. The data were statistically analyzed with Kruskal Wallis and Mann Whitney U tests. RESULTS: No significant difference was observed between the sealers (p > .05). EndoVac, Er:YAG and Er,Cr:YSGG laser activation groups were observed to have a significantly higher mean penetration depth, penetration percentage and penetration area than the Control group. There was a significant difference between all regions in all penetration parameters (p < .05). CONCLUSIONS: While the use of resin or bioceramic-based root canal sealers did not affect dentin tubule penetration, the use of activation techniques positively affect the dentin tubule penetration. The average tubule penetration and penetration area assessment techniques are suitable methods for the investigation of dentinal tubule penetration. RESEARCH HIGHLIGHTS: It can be stated that the use of resin or bioceramic based root canal sealers does not affect dentin tubule penetration and the use of irrigation activation techniques during removal of the smear layer positively affects dentinal tubule penetration. In addition, it has been determined that the average tubule penetration and penetration area assessment techniques are suitable methods for the investigation of dentinal tubule penetration.


Asunto(s)
Materiales de Obturación del Conducto Radicular , Capa de Barro Dentinario , Humanos , Cavidad Pulpar , Dentina , Diente Premolar , Microscopía Confocal , Irrigantes del Conducto Radicular/farmacología , Materiales de Obturación del Conducto Radicular/farmacología , Preparación del Conducto Radicular
15.
Curr Med Imaging ; 19(11): 1295-1301, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37278052

RESUMEN

OBJECTIVES: The position of the inferior alveolar canal (IAC) and its course in the mandible is crucial to prevent complications in oral surgical procedures. Therefore, the present study aims to predict the course of IAC using landmarks specific to the mandible and to correlate with cone-beam computed tomography images. METHODS: On the included panoramic radiographs (n=529), the closest point of the IAC to the inferior border of the mandible (Q) was determined, and the distances of this point to the mental (Mef) and mandibular foramen (Maf) were measured in millimeters. To determine the buccolingual course of the IAC on CBCT images (n=529), the distances from the center of the canal to the buccal and lingual cortices and between the cortices were measured at the level of the root apices of the first and second premolars and molars. Also, the positions of the Mef to adjacent premolars and molars were classified. RESULTS: The most common position of mental foramen was Type-3 (37.1%). On the coronal plane, it was also observed that as the Q point approaches the Mef, the IAC is located in the mandible's center at the second premolar level (p=0.008) and moves away from the midline at the level of the first molar (p=0.007). CONCLUSION: Based on the results, a correlation was observed between the horizontal course of the IAC and its proximity to the inferior border of the mandible. Therefore, the curvature of the IAC and its proximity to the mental foramen should be considered in oral surgeries.


Asunto(s)
Canal Mandibular , Diente Molar , Humanos , Mandíbula/diagnóstico por imagen , Radiografía Panorámica/métodos , Tomografía Computarizada de Haz Cónico/métodos
16.
Plant Physiol ; 156(4): 2082-97, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21690302

RESUMEN

Nonvolatile terpenoid phytoalexins occur throughout the plant kingdom, but until recently were not known constituents of chemical defense in maize (Zea mays). We describe a novel family of ubiquitous maize sesquiterpenoid phytoalexins, termed zealexins, which were discovered through characterization of Fusarium graminearum-induced responses. Zealexins accumulate to levels greater than 800 µg g⁻¹ fresh weight in F. graminearum-infected tissue. Their production is also elicited by a wide variety of fungi, Ostrinia nubilalis herbivory, and the synergistic action of jasmonic acid and ethylene. Zealexins exhibit antifungal activity against numerous phytopathogenic fungi at physiologically relevant concentrations. Structural elucidation of four members of this complex family revealed that all are acidic sesquiterpenoids containing a hydrocarbon skeleton that resembles ß-macrocarpene. Induced zealexin accumulation is preceded by increased expression of the genes encoding TERPENE SYNTHASE6 (TPS6) and TPS11, which catalyze ß-macrocarpene production. Furthermore, zealexin accumulation displays direct positive relationships with the transcript levels of both genes. Microarray analysis of F. graminearum-infected tissue revealed that Tps6/Tps11 were among the most highly up-regulated genes, as was An2, an ent-copalyl diphosphate synthase associated with production of kauralexins. Transcript profiling suggests that zealexins cooccur with a number of antimicrobial proteins, including chitinases and pathogenesis-related proteins. In addition to zealexins, kauralexins and the benzoxazinoid 2-hydroxy-4,7-dimethoxy-1,4-benzoxazin-3-one-glucose (HDMBOA-glucose) were produced in fungal-infected tissue. HDMBOA-glucose accumulation occurred in both wild-type and benzoxazine-deficient1 (bx1) mutant lines, indicating that Bx1 gene activity is not required for HDMBOA biosynthesis. Together these results indicate an important cooperative role of terpenoid phytoalexins in maize biochemical defense.


Asunto(s)
Ácidos/metabolismo , Hongos/fisiología , Sesquiterpenos/metabolismo , Zea mays/metabolismo , Zea mays/microbiología , Animales , Ciclopentanos/metabolismo , Etilenos/metabolismo , Conducta Alimentaria/efectos de los fármacos , Hongos/efectos de los fármacos , Hongos/crecimiento & desarrollo , Cromatografía de Gases y Espectrometría de Masas , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Genes de Plantas/genética , Insectos/efectos de los fármacos , Oxilipinas/metabolismo , Enfermedades de las Plantas/microbiología , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Sesquiterpenos/química , Sesquiterpenos/farmacología , Regulación hacia Arriba/efectos de los fármacos , Regulación hacia Arriba/genética , Zea mays/genética , Zea mays/inmunología , Fitoalexinas
17.
J Chem Ecol ; 38(4): 408-17, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22434385

RESUMEN

An unsaturated hydroxy-ester pheromone was isolated from the headspace and feces of male Diaprepes abbreviatus, identified, and synthesized. The pheromone, methyl (E)-3-(2-hydroxyethyl)-4-methyl-2-pentenoate, was discovered by gas chromatography-coupled electroantennogram detection (GC-EAD), and identified by gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance spectroscopy (NMR). The synthesis yielded an 86:14 mixture of methyl (E)-3-(2-hydroxyethyl)-4-methyl-2-pentenoate (active) and methyl (Z)-3-(2-hydroxyethyl)-4-methyl-2-pentenoate (inactive), along with a lactone breakdown product. The activity of the synthetic E-isomer was confirmed by GC-EAD, GC-MS, NMR, and bioassays. No antennal response was observed to the Z-isomer or the lactone. In a two-choice olfactometer bioassay, female D. abbreviatus moved upwind towards the synthetic pheromone or natural pheromone more often compared with clean air. Males showed no clear preference for the synthetic pheromone. This pheromone, alone or in combination with plant volatiles, may play a role in the location of males by female D. abbreviatus.


Asunto(s)
Atractivos Sexuales/análisis , Atractivos Sexuales/síntesis química , Gorgojos/metabolismo , Animales , Heces/química , Femenino , Masculino , Atractivos Sexuales/biosíntesis , Atractivos Sexuales/farmacología , Conducta Sexual Animal/efectos de los fármacos
18.
Biomed Res Int ; 2022: 7035367, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35075428

RESUMEN

The purpose of the paper was the assessment of the success of an artificial intelligence (AI) algorithm formed on a deep-convolutional neural network (D-CNN) model for the segmentation of apical lesions on dental panoramic radiographs. A total of 470 anonymized panoramic radiographs were used to progress the D-CNN AI model based on the U-Net algorithm (CranioCatch, Eskisehir, Turkey) for the segmentation of apical lesions. The radiographs were obtained from the Radiology Archive of the Department of Oral and Maxillofacial Radiology of the Faculty of Dentistry of Eskisehir Osmangazi University. A U-Net implemented with PyTorch model (version 1.4.0) was used for the segmentation of apical lesions. In the test data set, the AI model segmented 63 periapical lesions on 47 panoramic radiographs. The sensitivity, precision, and F1-score for segmentation of periapical lesions at 70% IoU values were 0.92, 0.84, and 0.88, respectively. AI systems have the potential to overcome clinical problems. AI may facilitate the assessment of periapical pathology based on panoramic radiographs.


Asunto(s)
Inteligencia Artificial , Diente , Algoritmos , Humanos , Redes Neurales de la Computación , Radiografía Panorámica
19.
J Ultrason ; 20(83): e307-e310, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33500799

RESUMEN

Aim of the study: Ultrasonographic examination of intraosseous jaw pathologies may reveal interesting incidental, mobile hyperechoic particles ("snowflakes") in anechoic areas. Purpose of this study is to explain and discuss this snowing-like ultrasonographic feature of intraosseous jaw pathologies. Material and methods: This study included 113 patients admitted to our clinic for examination: 43 (38.05%) males and 70 (61.9%) females with a mean age of 34.9 ± 17.2 years (range: 6-72 years). A total of 120 intraosseous lesions were evaluated prior to surgery using ultrasonography; these included non-neoplastic, odontogenic, and non-odontogenic lesions. Results: In total, 5 (4.1%) of the 120 lesions exhibited snowing-like feature on ultrasonography, including 2 (1.6% of total) of 3 incisive canal cysts, 2 (1.6% of total) of 7 dentigerous cysts, and 1 (0.8% of total) of 19 odontogenic keratocysts. Conclusions: Snowflakes evident on ultrasonography of intraosseous jaw lesions may be specific to certain pathologies. Future studies correlating radiologic and pathologic features of intraosseous jaw lesions should focus on ultrasonographic snowing-like appearance in different types of lesions and explore why they occur.

20.
Dentomaxillofac Radiol ; 50(6): 20200172, 2021 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-33661699

RESUMEN

OBJECTIVE: This study evaluated the use of a deep-learning approach for automated detection and numbering of deciduous teeth in children as depicted on panoramic radiographs. METHODS AND MATERIALS: An artificial intelligence (AI) algorithm (CranioCatch, Eskisehir-Turkey) using Faster R-CNN Inception v2 (COCO) models were developed to automatically detect and number deciduous teeth as seen on pediatric panoramic radiographs. The algorithm was trained and tested on a total of 421 panoramic images. System performance was assessed using a confusion matrix. RESULTS: The AI system was successful in detecting and numbering the deciduous teeth of children as depicted on panoramic radiographs. The sensitivity and precision rates were high. The estimated sensitivity, precision, and F1 score were 0.9804, 0.9571, and 0.9686, respectively. CONCLUSION: Deep-learning-based AI models are a promising tool for the automated charting of panoramic dental radiographs from children. In addition to serving as a time-saving measure and an aid to clinicians, AI plays a valuable role in forensic identification.


Asunto(s)
Inteligencia Artificial , Diente , Algoritmos , Niño , Humanos , Radiografía Panorámica , Diente Primario , Turquía
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