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1.
Med Oral Patol Oral Cir Bucal ; 29(1): e111-e118, 2024 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-38150608

RESUMEN

BACKGROUND: Incisional biopsy is indicated for intraoral tumors, but it is a contraindicated surgical procedure for major salivary glands. To avoid complications and facilitate diagnosis, fine needle aspiration biopsy (FNAB) is a type of biopsy widely used for preoperative diagnosis in these glands. MATERIAL AND METHODS: The aim of this study was to analyze the agreement between the diagnosis by FNAB (major glands), incisional biopsy (minor glands) and histopathological analysis of the surgical specimen in salivary gland tumors from a database (medical records) of patients treated in a cancer treatment reference center in the Northeast region of Brazil. RESULTS: The sample consisted of 110 cases, being 86 of them malignant tumors in major salivary glands (parotid gland=73; submandibular gland=13) and 24 cases in minor salivary glands (palate). The female gender was the most affected (57.3%), especially in patients over 60 years (42.7%). In the TNM classification, 41.8% of the cases were in T2 at the time of diagnosis, with most of the regional lymph nodes in N0 (85.5%) and 87.3% of the cases in M0. FNAB was able to identify malignant neoplasms in 68.6% of the cases (n=59), while incisional biopsy in palatal tumors obtained agreement of 75% of the cases (n=18). The analysis revealed that tumors classified as T3-T4 (p=0.012) showed greater agreement between pre- and post-surgical diagnosis. CONCLUSIONS: The results obtained in this study indicate that FNAB has similar accuracy to incisional biopsy in providing satisfactory preoperative diagnoses of malignant tumors in salivary glands.


Asunto(s)
Neoplasias de las Glándulas Salivales , Humanos , Femenino , Biopsia con Aguja Fina/métodos , Sensibilidad y Especificidad , Estudios Retrospectivos , Neoplasias de las Glándulas Salivales/patología , Glándulas Salivales
2.
BMC Biotechnol ; 23(1): 52, 2023 12 08.
Artículo en Inglés | MEDLINE | ID: mdl-38066557

RESUMEN

BACKGROUND: In this study, we designed a novel genetic circuit sensitive to Cd2+, Zn2+ and Pb2+ by mimicking the CadA/CadR operon system mediated heavy metal homeostasis mechanism of Pseudomonas aeruginosa. The regular DNA motifs on natural operon were reconfigured and coupled with the enhanced Green Fluorescent Protein (eGFP) reporter to develop a novel basic NOT type logic gate CadA/CadR-eGFP to respond metal ions mentioned above. A Genetically Engineered Microbial (GEM)-based biosensor (E.coli-BL21:pJET1.2-CadA/CadR-eGFP) was developed by cloning the chemically synthesised CadA/CadR-eGFP gene circuit into pJET1.2-plasmid and transforming into Escherichia coli (E. coli)-BL21 bacterial cells. RESULTS: The GEM-based biosensor cells indicated the reporter gene expression in the presence of Cd2+, Zn2+ and Pb2+ either singly or in combination. Further, the same biosensor cells calibrated for fluorescent intensity against heavy metal concentration generated linear graphs for Cd2+, Zn2+ and Pb2+ with the R2 values of 0.9809, 0.9761 and 0.9758, respectively as compared to non-specific metals, Fe3+ (0.0373), AsO43- (0.3825) and Ni2+ (0.8498) making our biosensor suitable for the detection of low concentration of the former metal ions in the range of 1-6 ppb. Furthermore, the GEM based biosensor cells were growing naturally within the concentration range of heavy metals, at 37 °C and optimum pH = 7.0 in the medium, resembling the characteristics of wildtype E.coli. CONCLUSION: Finally, the novel GEM based biosensor cells developed in this study can be applied for detection of targeted heavy metals in low concentration ranges (1-6 ppb) at normal bacterial physiological conditions.


Asunto(s)
Técnicas Biosensibles , Metales Pesados , Cadmio/metabolismo , Plomo/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Calibración , Metales Pesados/metabolismo , Zinc , Iones/metabolismo
3.
Med Oral Patol Oral Cir Bucal ; 28(2): e126-e130, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36641747

RESUMEN

BACKGROUND: This study aimed to evaluate the clinicopathological features of mucocutaneous diseases with manifestation in the head and neck region. MATERIAL AND METHODS: A retrospective analysis of a dermatology reference center database was carried out. Over 24 years. Clinicopathological data were collected from medical records and the data was analyzed by descriptive statistics. RESULTS: A total of 11.538 medical records were analyzed, being 152 cases of mucocutaneous diseases with manifestations in the head and neck region. Cutaneous lupus erythematosus was the most prevalent diagnosis (66.4%). Face (44.1%), females (79.6%), and patients with 45 years mean age were the most common features. In the oral cavity, the most affected region was the buccal mucosa (37.5%). CONCLUSIONS: Mucocutaneous diseases with head and neck manifestation were rare in the sample analyzed (1.3%), with cutaneous lupus erythematosus and lichen planus being the most common lesions in this region.


Asunto(s)
Dermatología , Liquen Plano , Lupus Eritematoso Cutáneo , Femenino , Humanos , Estudios Retrospectivos , Liquen Plano/diagnóstico , Lupus Eritematoso Cutáneo/patología , Mucosa Bucal/patología
4.
J Nematol ; 52: 1-3, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32270655

RESUMEN

The peach tree (Prunus persica) is the third most cultivated temperate fruit species in Brazil. In August 2017, peach seedling plants showing symptoms of stunting and multiple galls in the roots were detected in the municipality of Pelotas, state of Rio Grande do Sul, Brazil. Samples of peach roots were collected and they were subsequently processed to obtain eggs and second-stage juveniles (J2), to determine the number of nematodes per gram of roots and to proceed with morphological studies. Additionally, individual females were extracted from the peach roots and submitted to Meloidogyne species identification by electrophoresis using α-esterase (Est) and malate dehydrogenase (Mdh) phenotypes and perineal pattern. The nematode population density in the samples was 283 eggs + J2s per gram of fresh roots. The polymorphism analysis revealed the A3N1 phenotype, typical to Meloidogyne morocciensis. Perineal patterns of females showed oval squared shapes, with moderately high to high dorsal arches, streaks widely separated, generally continuous, sometimes broken; the phasmids were separate by 29.3 µm (25.43-31.94 µm), similar to M. arenaria and M. incognita, as observed by Hammah and Hirschmann (1990). The second-stage juveniles had the following morphometric characters: L = 389.3 ± 3.8 (377.5-425.1) µm, stylet = 13.9 ± 0.2 (12.7-14.9) µm, DGO = 3.6 ± 0.1 (3.3-4.2) µm, tail length 47.5 ± 0.6 (45.3-48.9) µm, hyaline tail terminus = 14.1 ± 0.3 (12.5-17.0) µm, a = 25.6 ± 0.4 (23.8-28.8) µm and c = 8.6 ± 0.1 (8.0-9.3). The known SCAR marker obtained for M. arenaria is the same as that amplified for M. morocciensis. Under greenhouse conditions, peach plants seedlings inoculated with 1,000 eggs (Pi) with M. morocciensis were evaluated 28 days after inoculation compared to non-inoculated plants. The inoculated peach plants showed a mean of 338 galls per root system, and a nematode reproduction factor of 10.3. Besides this plants exhibited a reduction in fresh weight of shoots and roots compared to the non-inoculated plants. These results confirm M. morocciensis pathogenicity on P. persica.The peach tree (Prunus persica) is the third most cultivated temperate fruit species in Brazil. In August 2017, peach seedling plants showing symptoms of stunting and multiple galls in the roots were detected in the municipality of Pelotas, state of Rio Grande do Sul, Brazil. Samples of peach roots were collected and they were subsequently processed to obtain eggs and second-stage juveniles (J2), to determine the number of nematodes per gram of roots and to proceed with morphological studies. Additionally, individual females were extracted from the peach roots and submitted to Meloidogyne species identification by electrophoresis using α-esterase (Est) and malate dehydrogenase (Mdh) phenotypes and perineal pattern. The nematode population density in the samples was 283 eggs + J2s per gram of fresh roots. The polymorphism analysis revealed the A3N1 phenotype, typical to Meloidogyne morocciensis. Perineal patterns of females showed oval squared shapes, with moderately high to high dorsal arches, streaks widely separated, generally continuous, sometimes broken; the phasmids were separate by 29.3 µm (25.43-31.94 µm), similar to M. arenaria and M. incognita, as observed by Hammah and Hirschmann (1990). The second-stage juveniles had the following morphometric characters: L = 389.3 ± 3.8 (377.5-425.1) µm, stylet = 13.9 ± 0.2 (12.7-14.9) µm, DGO = 3.6 ± 0.1 (3.3-4.2) µm, tail length 47.5 ± 0.6 (45.3-48.9) µm, hyaline tail terminus = 14.1 ± 0.3 (12.5-17.0) µm, a = 25.6 ± 0.4 (23.8-28.8) µm and c = 8.6 ± 0.1 (8.0-9.3). The known SCAR marker obtained for M. arenaria is the same as that amplified for M. morocciensis. Under greenhouse conditions, peach plants seedlings inoculated with 1,000 eggs (Pi) with M. morocciensis were evaluated 28 days after inoculation compared to non-inoculated plants. The inoculated peach plants showed a mean of 338 galls per root system, and a nematode reproduction factor of 10.3. Besides this plants exhibited a reduction in fresh weight of shoots and roots compared to the non-inoculated plants. These results confirm M. morocciensis pathogenicity on P. persica.

6.
Curr Protein Pept Sci ; 19(9): 900-908, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-28745221

RESUMEN

Rheumatic fever (RF) and rheumatic heart disease (RHD) follow untreated S. pyogenes throat infections in children who present susceptible genes that favor the development of autoimmune reactions. In this review, we focus on the genes that confer susceptibility and on the autoimmune reactions that occur due to molecular mimicry between human-tissue proteins and streptococcal M protein. Polyarthritis is the initial manifestation, which can evolve to carditis and severe valve damage; these culminate in rheumatic heart disease (RHD) or Sydenham's chorea, which affects the central nervous system. A perspective on vaccine development to prevent the disease is also discussed.


Asunto(s)
Cardiopatía Reumática/metabolismo , Cardiopatía Reumática/prevención & control , Vacunas/uso terapéutico , Autoinmunidad , Corea/etiología , Corea/inmunología , Corea/metabolismo , Corea/prevención & control , Citocinas/metabolismo , Antígenos de Histocompatibilidad Clase II/genética , Humanos , Imitación Molecular , Fiebre Reumática/etiología , Fiebre Reumática/inmunología , Fiebre Reumática/metabolismo , Fiebre Reumática/prevención & control , Cardiopatía Reumática/etiología , Cardiopatía Reumática/inmunología , Streptococcus pyogenes
7.
Behav Brain Res ; 331: 188-192, 2017 07 28.
Artículo en Inglés | MEDLINE | ID: mdl-28341609

RESUMEN

The potential of behavioral stress to affect epigenetic mechanisms of non-encephalic tissues is still underestimated. In the present study we evaluated the effects of chronic behavioral stress on the DNA methylation profile of rat lung cells. Furthermore, we evaluated the potential of physical exercise to modulate the changes evoked by behavioral stress in lung cells. Male Wistar rats were divided into four experimental groups: (1) animals submitted to chronic restraint stress (CRS) (ST group) during the period of the 67th-80th postnatal day (PND); (2) animals submitted to physical exercise (EX group) during the 53rd-79th PND; (3) animals submitted to swimming during the 53rd-79th PND and to CRS during the 67th-80th PND (EX-ST group); and (4) animals not submitted to stress or swimming protocols (CTL). Global DNA methylation was quantified using an ELISA-based approach and gene expression was evaluated by real time PCR. A decreased global DNA methylation profile was observed in the ST group, however physical exercise demonstrated protection of lung cells from this stress-related hypomethylation. Increased expression of the Dnmt1 gene was evidenced in the ST group, whereas physical exercise was shown to protect lung cells from this stress-related effect in the EX-ST group. Comparative analysis of the ST and EX groups revealed opposite effects on the expression of Dnmt3a and Dnmt3b; however, a stress-related increase in expression of Dnmt3a and Dnmt3b was not seen in the EX-ST group. Our data showed that behavioral stress induced significant changes in the DNA methylation profile of rat lung cells and that this could be modulated by physical exercise.


Asunto(s)
Conducta Animal/fisiología , Metilación de ADN , Restricción Física , Animales , Epigénesis Genética/genética , Masculino , Condicionamiento Físico Animal , Ratas Wistar , Restricción Física/métodos , Natación/fisiología
8.
Environ Entomol ; 45(4): 930-7, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27298391

RESUMEN

The spatial variation in the outcome of the interaction between secondary dispersers and seeds is superimposed upon the variation produced by primary dispersers. Investigating the factors that drive the outcome of the interactions with secondary seed dispersers thus represents an essential refinement to our understanding of the complete seed dispersal process. We studied the interactions between two ponerine ants (Pachycondyla striata Smith, 1858 and Odontomachus chelifer (Latreille, 1802)) with fruits experimentally set on the ground, and estimated the effects of ants on seedling establishment in three areas distributed along a 2-km stretch of a Brazilian Atlantic rainforest that differ in soil properties and vegetation physiognomies. We tested the hypothesis that interactions are more frequent, resulting in greater seedling establishment at the site with harsher abiotic and biotic conditions. Both ant species removed fruits frequently and have a positive effect on seedling establishment in all study areas, but fruit removal did not differ among areas, while seedling establishment was more pronounced at the site with stressful abiotic conditions. The two ant species differed in important aspects of their seed dispersal services, including the propensity to interact with seeds. As a result, both the species of ant and abiotic conditions interact at the scale of 2 km to determine the fate of seeds interacting with ants, thus creating a mosaic of outcomes with variable benefits to plants.


Asunto(s)
Hormigas/fisiología , Bosques , Dispersión de Semillas , Suelo/química , Animales , Brasil , Análisis Espacial
9.
Arq. bras. med. vet. zootec ; 68(1): 155-163, jan.-fev. 2016. tab
Artículo en Portugués | LILACS | ID: lil-771884

RESUMEN

Objetivou-se conhecer os teores de cobre, zinco, ferro e molibdênio em soro e fígado de pequenos ruminantes criados nos municípios de Casa Nova e Juazeiro, estado da Bahia, e verificar se há carência primária ou secundária de cobre. Foi avaliado um total de 160 amostras de ovinos e caprinos de ambos os sexos, coletados nos períodos seco e chuvoso. O valor de cobre sérico para caprinos foi de 13,8±0,3±mol/L e para ovinos foi de 12,2±0,4±mol/L, enquanto os teores hepáticos médios foram de 220ppm para caprinos e 238ppm para ovinos. O valor de zinco sérico para caprinos foi de 28,3±1,0±mol/L e para ovinos foi de 28,7±0,8±mol/L, enquanto os teores hepáticos médios foram de 99ppm para caprinos e 92ppm para ovinos. O valor de ferro sérico para caprinos foi de 61±3±mol/L e para ovinos foi de 64±2±mol/L, enquanto os teores hepáticos foram de 172ppm para caprinos e 221ppm para ovinos. Os valores médios de cobre não indicam ocorrência de carência deste elemento nos pequenos ruminantes criados nos municípios estudados. Os teores de zinco encontravam-se dentro dos intervalos de normalidade, não sendo verificada a necessidade de suplementação extra deste mineral. Os teores de ferro sérico apresentavam-se bem elevados, contudo sem que houvesse interferência suficiente no metabolismo do cobre de forma a resultar em uma deficiência cúprica.


The aim of this research was to know the copper, zinc, iron and molybdenum content in serum and liver of small ruminants raised in the cities of Casa Nova and Juazeiro, state of Bahia, and verify the occurrence of primary or secondary copper deficiency. A total of 160 samples of sheep and goats of both sexes collected in the dry and rainy season were evaluated. The values for serum copper in goats was 13.8±0.3±mol/L and in sheep it was 12.2±0.4 ±mol/L, while the mean liver concentration was 220 ppm for goats and 238 ppm for sheep. The serum zinc value for goats was 28.3±1.0±mol/L and for sheep it was 28.7±0.8±mol/L, while the mean liver concentration was 99 ppm for goats and 92 ppm for sheep. Serum iron value for goats was 61±3±mol/L and for sheep it was 64±2±mol/L, while liver levels were 172 ppm for goats and 221 ppm for sheep. Copper mean values do not indicate the occurrence of copper deficiency in small ruminants raised in the cities studied. Zinc levels were within the normal values and do not require extra supplementation of this mineral. The serum iron levels were elevated, however it did not interfere in copper metabolism in order to result in a cupric deficiency.


Asunto(s)
Animales , Hígado , Minerales , Rumiantes , Suero , Análisis del Suelo , Mataderos , Cobre , Hierro , Molibdeno
10.
Genet Mol Res ; 14(2): 7113-21, 2015 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-26125921

RESUMEN

Leishmania spp are the causative agents of a spectrum of diseases termed leishmaniasis that affect mammals, including humans and dogs. Although reactive nitrogen species are employed in the control of parasitism by the immune system, it is known that Leishmania can withstand this oxidative stress. As the mechanism by which these species are resistant to nitric oxide (NO) is poorly understood, the main objective of this study was to evaluate the expression of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) in Leishmania amazonensis and Leishmania chagasi promastigotes showing natural resistance to NO. GAPDH transcript levels were quantified by real-time polymerase chain reaction amplification, and GAPDH activity (assessed by levels of NADH oxidation) was measured by spectrophotometry. The level of nitration in total protein was assessed by immunoblotting. The results demonstrated an increase in GAPDH expression in resistant isolates of both species compared to susceptible isolates. The increase in GAPDH expression led to an increase in the activity of GAPDH in L. amazonensis human isolates resistant to NO. The pattern of protein nitration did not differ between sensitive and resistant isolates. Our results suggest that changes in expression of GAPDH may be responsible, at least in part, to natural resistance to NO found in human and canine Leishmania spp.


Asunto(s)
Expresión Génica/efectos de los fármacos , Gliceraldehído 3-Fosfato Deshidrogenasa (NADP+)/genética , Leishmania infantum/genética , Leishmania/genética , Estadios del Ciclo de Vida/efectos de los fármacos , Óxido Nítrico/farmacología , Proteínas Protozoarias/genética , Medios de Cultivo , Resistencia a Medicamentos , Gliceraldehído 3-Fosfato Deshidrogenasa (NADP+)/metabolismo , Leishmania/efectos de los fármacos , Leishmania/enzimología , Leishmania/crecimiento & desarrollo , Leishmania infantum/efectos de los fármacos , Leishmania infantum/enzimología , Leishmania infantum/crecimiento & desarrollo , NAD/metabolismo , Óxido Nítrico/metabolismo , Oxidación-Reducción , Proteínas Protozoarias/metabolismo , Nitrito de Sodio/química , Nitrito de Sodio/farmacología
11.
Plant Biol (Stuttg) ; 16(5): 956-66, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24641568

RESUMEN

The mistletoe Psittacanthus robustus was studied as a model to link flower phenology and nectar secretion strategy to pollinator behaviour and the reproductive consequences for the plant. The bright-coloured flowers presented diurnal anthesis, opened asynchronously throughout the rainy season and produced copious dilute nectar as the main reward for pollinators. Most nectar was secreted just after flower opening, with little sugar replenishment after experimental removals. During the second day of anthesis in bagged flowers, the flowers quickly reabsorbed the offered nectar. Low values of nectar standing crop recorded in open flowers can be linked with high visitation rates by bird pollinators. Eight hummingbirds and two passerines were observed as potential pollinators. The most frequent flower visitors were the hummingbirds Eupetomena macroura and Colibri serrirostris, which actively defended flowering mistletoes. The spatial separation between anthers, stigma and nectar chamber promotes pollen deposition on flapping wings of hovering hummingbirds that usually probe many flowers per visit. Seed set did not differ between hand-, self- and cross-pollinated flowers, but these treatments set significantly more seeds than flowers naturally exposed to flower visitors. We suggest that the limitation observed in the reproductive success of this plant is not related to pollinator scarcity, but probably to the extreme frequency of visitation by territorial hummingbirds. We conclude that the costs and benefits of plant reproduction depend on the interaction strength between flowers and pollinators, and the assessment of nectar secretion dynamics, pollinator behaviour and plant breeding system allows clarification of the complexity of such associations.


Asunto(s)
Aves/fisiología , Loranthaceae/fisiología , Néctar de las Plantas/metabolismo , Polinización , Animales , Conducta Animal , Flores/fisiología , Reproducción , Territorialidad
12.
Neotrop Entomol ; 40(6): 706-7, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-23939279

RESUMEN

Anastrepha serpentina (Wiedemann) is recorded for the first time in citrus (Rutaceae) in Brazil. Specimens were obtained from sweet orange (Citrus sinensis) sampled in the municipalities of Belém and Capitão Poço, and from mandarin orange (Citrus reticulata) from Tomé-Açu, state of Pará, Brazil.


Asunto(s)
Citrus/parasitología , Tephritidae/fisiología , Distribución Animal , Animales , Brasil
13.
Methods ; 49(4): 316-21, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19409999

RESUMEN

Streptococcus pyogenes causes severe invasive infections: the post-streptococcal sequelae of acute rheumatic fever (RF) and rheumatic heart disease (RHD), acute glomerulonephritis, and uncomplicated pharyngitis and pyoderma. Efforts to produce a vaccine against S. pyogenes began several decades ago, and different models have been proposed. Here, we describe the methodology used in the development of a new vaccine model, consisting of both T and B protective epitopes constructed as synthetic peptides and recombinant proteins. Two adjuvants were tested in an experimental inbred mouse model: a classical Freund's adjuvant and a new adjuvant (AFCo1) that induces mucosal immune responses and is obtained by calcium precipitation of a proteoliposome derived from the outer membrane of Neisseria meningitides B. The StreptInCor vaccine epitope co-administrated with AFCo1 adjuvant induced mucosal (IgA) and systemic (IgG) antibodies as preferential Th1-mediated immune responses. No autoimmune reactions were observed, suggesting that the vaccine epitope is safe.


Asunto(s)
Diseño de Fármacos , Vacunas Estreptocócicas/inmunología , Streptococcus pyogenes/inmunología , Secuencia de Aminoácidos , Animales , Femenino , Inmunidad Mucosa/efectos de los fármacos , Ratones , Ratones Endogámicos BALB C , Datos de Secuencia Molecular , Vacunas Estreptocócicas/administración & dosificación , Vacunas Estreptocócicas/síntesis química , Streptococcus pyogenes/efectos de los fármacos
14.
Braz J Biol ; 68(2): 403-7, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18660971

RESUMEN

Leptodactylus labyrinthicus tadpoles reach a large size in the nest through consumption of trophic eggs. We previously suggested that the trophic eggs are laid just after amplexus has finished, but our new data do not support this hypothesis. We also present further details on the natural history of the species with regard to breeding activity, spawning site, retreats and the ability of tadpoles in preying upon fully-growth heterospecific tadpoles. We also show that the tadpoles are mainly nocturnal and take diurnal refuges. We collected the data in Brazil in three localities within the Cerrado Biome. We examined burrows used by L. labyrinthicus males, verified if females still contained mature eggs just after released from amplexus, and tested the ability of tadpoles in preying fully-growth heterospecific tadpoles. Field observations and experiments were conducted on tadpole activity time, hiding behaviour and level of susceptibility to predation by the bird leaf-scrapers in four sheltering situations. Reproduction could start before the first rains; this may be advantageous by allowing the tadpoles to exploit eggs of other frogs. We found one floating nest built in a temporary pool. The nest of the species is normally circumscribed in an excavated basin beside the water body. Adult males were found during the day with their head-out of the entrance of underwater burrows, which were perforations through dense root mats beside calling/spawning sites. Probably, these burrows in permanently water-filled soil are actively excavated by males. Females released all their eggs during the amplexus, so trophic eggs are not produced by the currently-accepted mechanism. Fully-grown heterospecific tadpoles were not preyed upon by L. labyrinthicus tadpoles, which can prey only slow-moving newly hatched ones. Field tadpoles took shelter under mud/dead leaves during daylight and became exposed on the bottom at night. Free-ranging leaf-scrapers removed dead leaves from a pool with their beaks and preyed upon tadpoles. In the experiments, the tadpoles sheltered under gravel/leaves during daylight, but they were exposed at night. Leaf-scrapers ate all exposed tadpoles, but no tadpole of the gravel/leaves trays was consumed. Hence the nocturnal habits and use of diurnal refuges may protect the tadpoles from visual predators, such as the leaf-scrapers.


Asunto(s)
Anuros/fisiología , Aves/fisiología , Oviposición/fisiología , Conducta Predatoria/fisiología , Animales , Anuros/anatomía & histología , Anuros/crecimiento & desarrollo , Brasil , Femenino , Larva/crecimiento & desarrollo , Larva/fisiología , Masculino , Comportamiento de Nidificación/fisiología , Reproducción/fisiología , Estaciones del Año
15.
Braz. j. biol ; 68(2): 403-407, May 2008. graf
Artículo en Inglés | LILACS | ID: lil-486768

RESUMEN

Leptodactylus labyrinthicus tadpoles reach a large size in the nest through consumption of trophic eggs. We previously suggested that the trophic eggs are laid just after amplexus has finished, but our new data do not support this hypothesis. We also present further details on the natural history of the species with regard to breeding activity, spawning site, retreats and the ability of tadpoles in preying upon fully-growth heterospecific tadpoles. We also show that the tadpoles are mainly nocturnal and take diurnal refuges. We collected the data in Brazil in three localities within the Cerrado Biome. We examined burrows used by L. labyrinthicus males, verified if females still contained mature eggs just after released from amplexus, and tested the ability of tadpoles in preying fully-growth heterospecific tadpoles. Field observations and experiments were conducted on tadpole activity time, hiding behaviour and level of susceptibility to predation by the bird leaf-scrapers in four sheltering situations. Reproduction could start before the first rains; this may be advantageous by allowing the tadpoles to exploit eggs of other frogs. We found one floating nest built in a temporary pool. The nest of the species is normally circumscribed in an excavated basin beside the water body. Adult males were found during the day with their head-out of the entrance of underwater burrows, which were perforations through dense root mats beside calling/spawning sites. Probably, these burrows in permanently water-filled soil are actively excavated by males. Females released all their eggs during the amplexus, so trophic eggs are not produced by the currently-accepted mechanism. Fully-grown heterospecific tadpoles were not preyed upon by L. labyrinthicus tadpoles, which can prey only slow-moving newly hatched ones. Field tadpoles took shelter under mud/dead leaves during daylight and became exposed on the bottom at night. Free-ranging leaf-scrapers removed...


Girinos de L. labyrinthicus crescem parcialmente no ninho consumindo ovos tróficos. Sugerimos anteriormente que os ovos tróficos seriam postos logo após o amplexo, porém nossos novos dados não corroboram esta hipótese. Apresentamos também mais detalhes da história natural da espécie relacionados à estação reprodutiva, local de desova, abrigos e capacidade dos girinos em predar girinos heteroespecíficos plenamente desenvolvidos. Demonstramos ainda que os girinos são noturnos e se utilizam de refúgios diurnos. Coletamos os dados no Brasil em três locais no Bioma Cerrado. Determinamos o formato e dimensões de buracos utilizados por machos, verificamos se fêmeas liberadas do amplexo ainda portavam óvulos maduros e testamos a capacidade dos girinos em predar girinos heteroespecíficos plenamente desenvolvidos. Realizamos observações naturalísticas e experimentais com girinos para descrever o horário de atividade, comportamento de refúgio e grau de suscetibilidade à predação pela ave sabiá-poca em diferentes tipos de substratos. Desovas podiam ocorrer antes das primeiras chuvas, possibilitando aos girinos explorar ovos de outros anuros no meio da estação chuvosa. Encontramos um ninho construído na superfície da água de uma poça temporária. Os ninhos da espécie geralmente são circunscritos em bacias escavadas às margens do corpo d'água. Machos adultos foram encontrados durante o dia em buracos subaquáticos, os quais eram perfurações adjacentes aos sítios de vocalização/desova. Provavelmente, esses buracos em solos encharcados são ativamente escavados pelos machos. As fêmeas liberam todos os óvulos durante o amplexo, portanto, os ovos tróficos não são produzidos pelo mecanismo aceito presentemente. Os girinos oferecidos nos testes não foram consumidos pelos girinos de L. labyrinthicus, os quais conseguem predar apenas recém-eclodidos. No campo, os girinos se refugiavam entre o lodo ou folhas mortas durante o dia, porém ficavam expostos sobre...


Asunto(s)
Animales , Femenino , Masculino , Anuros/fisiología , Aves/fisiología , Oviposición/fisiología , Conducta Predatoria/fisiología , Anuros/anatomía & histología , Anuros/crecimiento & desarrollo , Brasil , Larva/crecimiento & desarrollo , Larva/fisiología , Comportamiento de Nidificación/fisiología , Reproducción/fisiología , Estaciones del Año
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