Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 66
Filtrar
1.
J Acoust Soc Am ; 155(1): 781-789, 2024 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-38289152

RESUMO

Danionella cerebrum has recently been proposed as a promising model to investigate the structure and function of the adult vertebrate brain, including the development of vocal-auditory neural pathways. This genetically tractable and transparent cypriniform is highly vocal, but limited information is available on its acoustic behavior and underlying biological function. Our main goal was to characterize the acoustic repertoire and diel variation in sound production of D. cerebrum, as well as to investigate the relationship between vocal behavior and reproduction. Sound recordings demonstrated high vocal activity, with sounds varying from short sequences of pulses known as "bursts" (comprising up to 15 pulses) to notably longer sounds, termed "long bursts", which extended up to 349 pulses with over 2.7 s. Vocal activity peaked at midday and it was very low at night with only a few bursts. While the number of pulses was higher during the daytime, the interpulse interval was longer at night. In addition, calling time was positively associated with the number of viable eggs, suggesting that acoustic communication is important for reproduction. These preliminary findings reveal the potential of using D. cerebrum to investigate vocal plasticity and the implications for sexual selection and reproduction in a novel vertebrate model for neuroscience.


Assuntos
Encéfalo , Som , Animais , Peixes , Vias Auditivas , Vocalização Animal
2.
J Exp Biol ; 226(22)2023 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-37767687

RESUMO

The three otolithic endorgans of the inner ear are known to be involved in sound detection in different teleost fishes, yet their relative roles for auditory-vestibular functions within the same species remain uncertain. In zebrafish (Danio rerio), the saccule and utricle are thought to play key functions in encoding auditory and vestibular information, respectively, but the biological function of the lagena is not clear. We hypothesized that the zebrafish saccule serves as a primary auditory endorgan, making it more vulnerable to noise exposure, and that the lagena might have an auditory function given its connectivity to the saccule and the dominant vestibular function of the utricle. We compared the impact of acoustic trauma (continuous white noise at 168 dB for 24 h) between the sensory epithelia of the three otolithic endorgans. Noise treatment caused hair cell loss in both the saccule and lagena but not in the utricle. This effect was identified immediately after acoustic treatment and did not increase 24 h post-trauma. Furthermore, hair cell loss was accompanied by a reduction in presynaptic activity measured based on ribeye b presence, but mainly in the saccule, supporting its main contribution for noise-induced hearing loss. Our findings support the hypothesis that the saccule plays a major role in sound detection and that the lagena is also acoustically affected, extending the species hearing dynamic range.


Assuntos
Células Ciliadas Auditivas , Peixe-Zebra , Animais , Ruído/efeitos adversos , Sáculo e Utrículo , Membrana dos Otólitos , Acústica
3.
J Exp Biol ; 225(7)2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35258623

RESUMO

Anthropogenic noise can be hazardous for the auditory system and wellbeing of animals, including humans. However, very limited information is known on how this global environmental pollutant affects auditory function and inner ear sensory receptors in early ontogeny. The zebrafish (Danio rerio) is a valuable model in hearing research, including investigations of developmental processes of the vertebrate inner ear. We tested the effects of chronic exposure to white noise in larval zebrafish on inner ear saccular sensitivity and morphology at 3 and 5 days post-fertilization (dpf), as well as on auditory-evoked swimming responses using the prepulse inhibition (PPI) paradigm at 5 dpf. Noise-exposed larvae showed a significant increase in microphonic potential thresholds at low frequencies, 100 and 200 Hz, while the PPI revealed a hypersensitization effect and a similar threshold shift at 200 Hz. Auditory sensitivity changes were accompanied by a decrease in saccular hair cell number and epithelium area. In aggregate, the results reveal noise-induced effects on inner ear structure-function in a larval fish paralleled by a decrease in auditory-evoked sensorimotor responses. More broadly, this study highlights the importance of investigating the impact of environmental noise on early development of sensory and behavioural responsiveness to acoustic stimuli.


Assuntos
Orelha Interna , Perda Auditiva Provocada por Ruído , Animais , Limiar Auditivo/fisiologia , Células Ciliadas Auditivas/fisiologia , Larva/fisiologia , Peixe-Zebra/fisiologia
4.
Parasitology ; 148(1): 42-52, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33070783

RESUMO

Although parasites represent a major component of biodiversity, they remain poorly assessed, especially in remote regions. In this study, we screened 461 reptiles from Socotra, the largest and most biologically diverse archipelago in Arabia. Using 18S rRNA primers, we detected various apicomplexan parasites, namely haemogregarines, sarcocystids and eimeriids. Haemogregarines were the most common and genetically diverse, followed by sarcocystids (genus Sarcocystis) and eimeriids (genera Isospora and Lankesterella). All were related to parasites of other reptiles, including species from Arabia, Northern Africa and Asia. Like their 29 endemic reptile hosts, almost all Socotran parasites presented high genetic divergence and ecological differences from those found elsewhere, and probably represent undescribed endemic species. Among hosts, skinks were the most parasitized, which contrasted with similar studies from other areas, probably due to their more generalist diet and habitat use. As expected due to its high species richness, geckos harboured the highest parasite diversity in the archipelago. Parasite diversity also seemed to be correlated to island size, as the largest island harboured most haplotypes. This study emphasizes the importance of screening parasites in wild hosts from remote regions and of considering host ecology to understand disease transmission across taxa.


Assuntos
Coccidiose/transmissão , Eucoccidiida , Répteis/parasitologia , Animais , Animais Selvagens/parasitologia , Biodiversidade , Coccidiose/veterinária , DNA de Protozoário , Eimeriidae/genética , Eimeriidae/isolamento & purificação , Eucoccidiida/genética , Eucoccidiida/isolamento & purificação , Variação Genética , Especificidade de Hospedeiro , Ilhas do Oceano Índico/epidemiologia , Isospora/genética , Isospora/isolamento & purificação , Lagartos/parasitologia , Filogenia , Prevalência , RNA Ribossômico 18S/genética , Sarcocystis/genética , Sarcocystis/isolamento & purificação
5.
Mol Phylogenet Evol ; 133: 166-175, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30641271

RESUMO

The Socotra Archipelago in the Arabian Sea is considered one of the most geo-politically isolated landforms on earth and a center of endemism. The archipelago is located at the western edge of the Indian Ocean and comprises four islands: Socotra, Darsa, Samha, and Abd al Kuri. Here we provide an integrative study on Haemodracon geckos, the sole genus of geckos strictly endemic to the archipelago. The sympatric distribution of Haemodracon riebeckii and H. trachyrhinus on Socotra Island provides a unique opportunity to explore evolutionary relationships and speciation patterns, examining the interplay between possible sympatric and allopatric scenarios. We used molecular data for phylogenetic inference, species delimitation analyses, and to infer the diversification timeframe. Multivariate statistics were used to analyze morphological data. Ecological comparisons were explored for macro-niches using species distribution models and observations were used for micro-habitat use. Haemodracon species exhibit great levels of intraspecific genetic diversity. Our calibration estimates revealed that Haemodracon diverged from its closest relative, the mainland genus Asaccus, in the Eocene, before the detachment of the archipelago. The two Haemodracon species diversified in situ on Socotra Island during the Middle Miocene, after the archipelago's isolation, into the two reciprocally monophyletic recognized species. Their divergence is associated mostly with remarkable body size differences and micro-habitat segregation, with low levels of climatic and body shape divergences within their sympatric distributions. These results display how ecological, sympatric speciation, and allopatric speciation followed by secondary contact, may both have varying roles at different evolutionary phases.


Assuntos
Ecossistema , Ilhas , Lagartos/genética , Animais , Especiação Genética , Variação Genética , Oceano Índico , Lagartos/classificação , Filogenia , Filogeografia
6.
J Craniofac Surg ; 30(7): e653-e655, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31490443

RESUMO

The management of victims of gunshot fractures is a challenge for surgeons, mainly due to the complexity of the injury itself and degree of bone comminution. The titanium functionally dynamic bridging plate has often been used in reconstructive surgery after mandibular fractures. The classic indication for bridge plate use is comminuted fractures with or without associated substance losses. The aim of this article is report the case of gunshot victim and to discuss the bridge plate technique utilized for treatment. A 21 years-old, melanoderma, male patient was victim of a firearm-related assault, with comminutive fracture of the mandibular body. The protocol for the bridging plate technique was performed. The patient is in postoperative follow-up of eight months, not present aesthetic or functional complaints, stable occlusion, satisfactory mouth opening and no clinical signs of infection.


Assuntos
Fraturas Cominutivas/cirurgia , Mandíbula/cirurgia , Fraturas Mandibulares/cirurgia , Ferimentos por Arma de Fogo/cirurgia , Humanos , Masculino , Procedimentos de Cirurgia Plástica , Resultado do Tratamento , Adulto Jovem
7.
Int J Mol Sci ; 20(11)2019 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-31174340

RESUMO

Over the previous decades, numerous studies focused on how oceanic islands have contributed to determine the phylogenetic relationships and times of origin and diversification of different endemic lineages. The Macaronesian Islands (i.e., Azores, Madeira, Selvagens, Canaries, and Cabo Verde), harbour biotas with exceptionally high levels of endemism. Within the region, the vascular plants and reptiles constitute two of the most important radiations. In this study we compare relevant published phylogenetic data and diversification rates retrieved within Cabo Verde endemic lineages and discuss the importance of choosing appropriate phylogeny-based methods to investigate diversification dynamics on islands. From this selective literature-based review, we summarize the software packages used in Macaronesian studies and discuss their adequacy considering the published data to obtain well-supported phylogenies in the target groups. We further debate the importance of Next Generation Sequencing (NGS), to investigate the evolutionary processes of diversification in the Macaronesian Islands. Analysis of genomic data provides phylogenetic resolution for rapidly evolving species radiations, suggesting a great potential to improve the phylogenetic signal and divergence time estimates in insular lineages. The most important Macaronesian reptile radiations provide good case-studies to compare classical phylogenetic methods with new tools, such as phylogenomics, revealing a high value for research on this hotspot area.


Assuntos
Biodiversidade , Genômica/métodos , Filogenia , Répteis/classificação , Animais , Cabo Verde , Especiação Genética , Genômica/normas , Metanálise como Assunto , Répteis/genética
8.
J Exp Biol ; 221(Pt 22)2018 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-30171096

RESUMO

Acoustic communication is an important part of social behaviour of fish species that live or breed in shallow noisy waters. Previous studies have shown that some fish species exploit a quiet window in the background noise for communication. However, it remains to be examined whether hearing abilities and sound production of fish are adapted to marine habitats presenting high hydrodynamism. Here, we investigated whether the communication system of the painted (Pomatoschistus pictus) and the marbled (Pomatoschistus marmoratus) gobies is adapted to enhance sound transmission and reception in Atlantic shallow water environments. We recorded and measured the sound pressure levels of social vocalisations of both species, as well as snapshots of ambient noise of habitats characterised by different hydrodynamics. Hearing thresholds (in terms of both sound pressure and particle acceleration) and responses to conspecific signals were determined using the auditory evoked potential recording technique. We found that the peak frequency range (100-300 Hz) of acoustic signals matched the best hearing sensitivity in both species and appeared well adapted for short-range communication in Atlantic habitats. Sandy/rocky exposed beaches presented a quiet window, observable even during the breaking of moderate waves, coincident with the main sound frequencies and best hearing sensitivities of both species. Our data demonstrate that the hearing abilities of these gobies are well suited to detect conspecific sounds within typical interacting distances (a few body lengths) in Atlantic shallow waters. These findings lend support to the acoustic adaptive hypothesis, under the sensory drive framework, proposing that signals and perception systems coevolve to be effective within local environment constraints.


Assuntos
Limiar Auditivo/fisiologia , Perciformes/fisiologia , Vocalização Animal/fisiologia , Animais , Hidrodinâmica , Masculino
9.
J Hered ; 108(3): 270-279, 2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-27940474

RESUMO

The biogeographic dynamics affecting the Indian subcontinent, East and Southeast Asia during the Plio-Pleistocene has generated complex biodiversity patterns. We assessed the molecular biogeography of the small Indian civet (Viverricula indica) through mitogenome and cytochrome b + control region sequencing of 89 historical and modern samples to (1) establish a time-calibrated phylogeography across the species' native range and (2) test introduction scenarios to western Indian Ocean islands. Bayesian phylogenetic analyses identified 3 geographic lineages (East Asia, sister-group to Southeast Asia and the Indian subcontinent + northern Indochina) diverging 3.2-2.3 million years ago (Mya), with no clear signature of past demographic expansion. Within Southeast Asia, Balinese populations separated from the rest 2.6-1.3 Mya. Western Indian Ocean populations were assigned to the Indian subcontinent + northern Indochina lineage and had the lowest mitochondrial diversity. Approximate Bayesian computation did not distinguish between single versus multiple introduction scenarios. The early diversification of the small Indian civet was likely shaped by humid periods in the Late Pliocene-Early Pleistocene that created evergreen rainforest barriers, generating areas of intra-specific endemism in the Indian subcontinent, East, and Southeast Asia. Later, Pleistocene dispersals through drier conditions in South and Southeast Asia were likely, giving rise to the species' current natural distribution. Our molecular data supported the delineation of only 4 subspecies in V. indica, including an endemic Balinese lineage. Our study also highlighted the influence of prefirst millennium AD introductions to western Indian Ocean islands, with Indian and/or Arab traders probably introducing the species for its civet oil.


Assuntos
Filogenia , Filogeografia , Viverridae/classificação , Viverridae/genética , Animais , Citocromos b/genética , DNA Mitocondrial , Evolução Molecular , Frequência do Gene , Variação Genética , Genoma Mitocondrial , Haplótipos , Ilhas do Oceano Índico
10.
Naturwissenschaften ; 103(11-12): 97, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27889831

RESUMO

Distributions of sedentary ectotherms are dependent on temperature and humidity due to their low homeostatic and dispersal abilities. Lizards are strongly conditioned by temperature, but hydric environment may be also important, at least in arid environments. Biotic interactions may also play a role in range patterns, but they are of minor importance in islands where native species monopolize well-delimited niche spaces. On the arid island of São Vicente (Cabo Verde), two endemic lizards display different spatial patterns. While the gecko Tarentola substituta is widely distributed across the island, the skink Chioninia stangeri is restricted to the NE, which is cooler, more humid, and vegetated. We hypothesized that this is due to differences in the fundamental niche, specifically in ecophysiology. We predict that C. stangeri should select for lower temperatures and lose more water by evaporation than T. substituta. We submitted adults of each species to standard experiments to assess preferred body temperatures (Tp) and evaporative water loss (EWL) rates, and examined the variation between species and through time using repeated-measures AN(C)OVAs. Results only partially supported our expectations. Contrary to the prediction, skinks attained higher Tp than geckos but in the long term showed a trend for higher EWL as predicted. Thus, while ecophysiology certainly contributes to functional interpretation of species distributions, it needs to be combined with other evidence such as habitat use and evolutionary history. These findings will be useful to perform mechanistic models to better understand the impact of climate change and habitat disturbance on these endemic species.


Assuntos
Distribuição Animal/fisiologia , Ecossistema , Lagartos/fisiologia , Animais , Ilhas , Especificidade da Espécie , Temperatura , Água
11.
Adv Exp Med Biol ; 877: 291-318, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26515320

RESUMO

Fish represent the largest group of vertebrates and display the greatest diversity of auditory structures. However, studies addressing how the form and function of the auditory system change during development to enhance perception of the acoustic environment are rather sparse in this taxon compared to other vertebrate groups. An ontogenetic perspective of the auditory system in fishes provides a readily testable framework for understanding structure-function relationships. Additionally, studying ancestral models such as fish can convey valuable comparable information across vertebrates, as early developmental events are often evolutionary conserved. This chapter reviews the literature on the morphological development of the fish auditory system, with particular focus on the inner ear structures that evolve from an otic placode during early embryonic development and then continue to undergo differentiation and maturation in the postembryonic phase. Moreover, the chapter provides a systematic overview of how auditory sensitivity develops during ontogeny. Although most studies indicate a developmental improvement in auditory sensitivity, there is considerably species-specific variation. Lastly, the paucity of information and literature concerning the development of auditory capabilities for social communication in fishes is also discussed. Further investigation on the development of structure and function of the fish auditory system is recommended in order to obtain a deeper understanding of how ontogenetic morphological changes in the auditory pathway relate to modifications in acoustic reception, auditory processing, and the capacity to communicate acoustically.


Assuntos
Vias Auditivas/fisiologia , Orelha Interna/fisiologia , Peixes/fisiologia , Audição/fisiologia , Acústica , Animais , Vias Auditivas/embriologia , Vias Auditivas/crescimento & desenvolvimento , Percepção Auditiva/fisiologia , Limiar Auditivo/fisiologia , Evolução Biológica , Orelha Interna/embriologia , Orelha Interna/crescimento & desenvolvimento , Peixes/embriologia , Peixes/crescimento & desenvolvimento , Especificidade da Espécie
12.
J Exp Biol ; 218(Pt 18): 2864-72, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26400979

RESUMO

Vocal differentiation is widely documented in birds and mammals but has been poorly investigated in other vertebrates, including fish, which represent the oldest extant vertebrate group. Neural circuitry controlling vocal behaviour is thought to have evolved from conserved brain areas that originated in fish, making this taxon key to understanding the evolution and development of the vertebrate vocal-auditory systems. This study examines ontogenetic changes in the vocal repertoire and whether vocal differentiation parallels auditory development in the Lusitanian toadfish Halobatrachus didactylus (Batrachoididae). This species exhibits a complex acoustic repertoire and is vocally active during early development. Vocalisations were recorded during social interactions for four size groups (fry: <2 cm; small juveniles: 2-4 cm; large juveniles: 5-7 cm; adults >25 cm, standard length). Auditory sensitivity of juveniles and adults was determined based on evoked potentials recorded from the inner ear saccule in response to pure tones of 75-945 Hz. We show an ontogenetic increment in the vocal repertoire from simple broadband-pulsed 'grunts' that later differentiate into four distinct vocalisations, including low-frequency amplitude-modulated 'boatwhistles'. Whereas fry emitted mostly single grunts, large juveniles exhibited vocalisations similar to the adult vocal repertoire. Saccular sensitivity revealed a three-fold enhancement at most frequencies tested from small to large juveniles; however, large juveniles were similar in sensitivity to adults. We provide the first clear evidence of ontogenetic vocal differentiation in fish, as previously described for higher vertebrates. Our results suggest a parallel development between the vocal motor pathway and the peripheral auditory system for acoustic social communication in fish.


Assuntos
Limiar Auditivo/fisiologia , Batracoidiformes/crescimento & desenvolvimento , Batracoidiformes/fisiologia , Sáculo e Utrículo/fisiologia , Vocalização Animal/fisiologia , Animais , Potenciais Evocados , Feminino , Masculino
13.
Genes (Basel) ; 15(4)2024 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-38674438

RESUMO

The green monkey Chlorocebus sabaeus, L. 1766, native to West Africa, was introduced to the Cabo Verde Archipelago in the 16th century. Historical sources suggest that, due to the importance of Cabo Verde as a commercial entrepôt in the Atlantic slave trade, establishing the precise place of origin of this introduced species is challenging. Non-invasive fecal samples were collected from feral and captive green monkey individuals in Cabo Verde. Two mitochondrial fragments, HVRI and cyt b, were used to confirm the taxonomic identification of the species and to tentatively determine the geographic origin of introduction to the archipelago from the African continent. By comparing the new sequences of this study to previously published ones, it was shown that Cabo Verde individuals have unique haplotypes in the HVRI, while also showing affinities to several populations from north-western coastal Africa in the cyt b, suggesting probable multiple sources of introduction and an undetermined most probable origin. The latter is consistent with historical information, but may also have resulted from solely using mtDNA as a genetic marker and the dispersal characteristics of the species. The limitations of the methodology are discussed and future directions of research are suggested.


Assuntos
DNA Mitocondrial , Animais , DNA Mitocondrial/genética , Chlorocebus aethiops/genética , Cabo Verde , Filogenia , Citocromos b/genética , Haplótipos , Espécies Introduzidas , Filogeografia , Fezes/química
14.
J Dent (Shiraz) ; 25(1): 59-67, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38544779

RESUMO

Statement of the Problem: Periodontitis is an inflammatory disease that causes bone loss. Some patients do not respond well to the classic treatment and need therapies that minimize bone loss, the main sequel of the disease. Chenopodium ambrosioides L. has stood out due to its anti-inflammatory and anti-oxidative activities. However, no study has yet investigated its effect on periodontitis. Purpose: This study aimed to evaluate the bone protective effect of Chenopodium ambrosioides L. (CAL) extract on ligature-induced periodontitis model in rats. Materials and Method: For this, a pre-clinical assay was performed, using male Wistar rats divided into 3 groups: Naive (N) (n=6), not submitted to any procedure; Saline (SAL) (n=6), submitted to ligature-induced periodontitis and receiving 2 ml/kg of 0.9% saline solution; and CAL extract, which was subdivided into 3 subgroups (n=6/subgroup) receiving the CAL at 3 (CAL3), 10 (CAL10) or 30 mg/kg (CAL30). All agents were given, by oral gavage, 30 min before periodontitis induction and daily until euthanasia (11th day). By then, maxillae were removed for macroscopic, histological, and histometric analyses. Kidneys, liver, and stomach were collected to evaluate the safety of CAL extract. High-performance liquid chromatography (HPLC) assay was used to investigate the flavonoid content in the extract. Results: Chenopodium ambrosioides L. extract at 30mg/kg showed a reduction by 58% in bone loss marked by an increase (+35%) in the number of osteoblasts and a reduction (-51%) on the number of osteoclasts (p< 0.05). No significant alteration in the liver, kidney, or stomach was seen. Rutin was the main flavonoid found. Conclusion: In summary, it was observed that Chenopodium ambrosioides L. extract has shown important anti-inflammatory and bone anabolic and anti-resorptive properties without causing toxicity in the main organs. Rutin, as the main flavonoid of the extract, seems to be responsible for the beneficial effect of this agent.

15.
Sci Rep ; 14(1): 8215, 2024 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-38589479

RESUMO

To investigate de effect of PAb gel on the bone tissue of rats submitted to Bisphosphonate-related osteonecrosis of the jaws (BRONJ). Initially, 54 animals were submitted to BRONJ model by Zoledronic Acid (ZA) (0.1 mg/kg 3x/wk for 9 wk, ip), followed by the 1st upper left molar extraction at the 8th wk. After tooth removal, the animals were divided into 3 groups, ZA that received placebo gel or PAb gel that received 1% PAb gel, inside the dental alveolus. The control Group (CONTROL) received 0.1 mg/kg of 0.9% saline and then placebo gel. Three weeks after tooth extraction, the animals were euthanized, and maxillae were colleted for macroscopic, radiographic, histological and Raman spectomery assays. Additionally, GSK3b, beta-catenin, and Runx2 mRNA expressions were determined. Blood samples were collected for the analysis of Bone-specific alkaline phosphatase (BALP) levels. PAb gel improved mucosal healing, increased the number of viable osteocytes, while it reduced the number of empty lacunae, as well as the amount of bone sequestration. Furthermore, PAb gel positively influenced the number and functionality of osteoblasts by stimulating Wnt signaling, thereby inducing bone remodeling. Additionally, PAb gel contributed to improved bone quality, as evidenced by an increase in bone mineral content, a decrease in bone solubility, and an enhancement in the quality of collagen, particularly type I collagen. PAb gel mitigated bone necrosis by stimulating of bone remodeling through Wnt signaling and concurrently improved bone quality. PAb gel emerges as a promising pharmacological tool for aiding in BRONJ therapy or potentially preventing the development of BRONJ.


Assuntos
Agaricus , Osteonecrose da Arcada Osseodentária Associada a Difosfonatos , Conservadores da Densidade Óssea , Animais , Ratos , Osteonecrose da Arcada Osseodentária Associada a Difosfonatos/tratamento farmacológico , Osteonecrose da Arcada Osseodentária Associada a Difosfonatos/etiologia , Osteonecrose da Arcada Osseodentária Associada a Difosfonatos/patologia , Difosfonatos , Maxila/patologia , Extração Dentária , Via de Sinalização Wnt , Ácido Zoledrônico
16.
Genes (Basel) ; 14(2)2023 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-36833307

RESUMO

Invasive species disrupt relations between endemics and their ecosystem and are an increasing biodiversity conservation problem. The Hemidactylus genus comprises the most successful invasive reptile species, including the worldwide-distributed Hemidactylus mabouia. In this study, we used 12S and ND2 sequences to taxonomically identify and tentatively determine the diversity and origin of these invaders in Cabo Verde while also clarifying this for several Western Indian Ocean (WIO) populations. By comparing our sequences to recently published ones, we showed, for the first time, that Cabo Verde individuals belong to the H. mabouia sensu stricto lineage and that both of its sublineages (a and b) occur there. Both haplotypes are also in Madeira, which indicates a connection between these archipelagos, possibly related to the past Portuguese trading routes. Across the WIO, results clarified the identity of many island and coastal populations, showing that this likely invasive H. mabouia lineage is widespread in the region, including northern Madagascar, with important conservation implications. Colonisation origins were difficult to access due to the wide geographical spread of these haplotypes; thus, several possible scenarios were outlined. The introduction of this species throughout western and eastern Africa may threaten endemic taxa and needs to be closely monitored.


Assuntos
Ecossistema , Lagartos , Humanos , Animais , Navios , Biodiversidade , Cabo Verde , Espécies Introduzidas
17.
Biology (Basel) ; 12(9)2023 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-37759565

RESUMO

Noise pollution is creating a wide range of health problems related to physiological stress and anxiety that impact the social life of vertebrates, including humans. Ageing is known to be associated with changes in susceptibility to acoustic stimuli; however, the interaction between noise effects and senescence is not well understood. We tested the effects of 24 h continuous white noise (150 dB re 1 Pa) on both young adults and old zebrafish in terms of anxiety (novel tank diving test), social interactions (with mirror/conspecific attraction), and shoaling behaviour. Both noise and ageing induced higher anxiety responses in a novel environment. Since the old zebrafish showed longer bottom dwelling, acoustic treatment induced the opposite pattern with an initial increase in vertical exploration in the aged individuals. Both noise- and age-related anxiety responses were lowered when individuals were tested within a group. Regarding social interactions, both noise and ageing seemed to cause an increase in their proximity to a mirror. Although the results were not statistically significant, noise exposure seemed to further enhance conspecific attraction. Moreover, the interindividual distance within a shoal decreased with noise treatment in the aged individuals. This study is a first attempt to investigate the effects of both noise and ageing on zebrafish behaviour, suggesting the age-dependent physiological coping mechanisms associated with environmental stress.

18.
Minerva Gastroenterol (Torino) ; 69(3): 374-381, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35343663

RESUMO

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is a rising global health issue. The influence of muscle in its pathophysiology has recently gained attention. Our aim was to investigate the association of low muscle mass, strength, and performance with the presence and severity of NAFLD. METHODS: Patients with metabolic syndrome followed in an outpatient clinic, were consecutively included, between April 1st and December 31st, 2019. Abdominal ultrasound for the diagnosis of NAFLD, NAFLD fibrosis score (NFS) and Fibrosis-4 Index (FIB-4) for determination of significant fibrosis, dual-energy X-ray absorptiometry for calculation of skeletal muscle index (SMI = appendicular skeletal mass / weight x100) and sarcopenic index (SI = appendicular skeletal mass / Body Mass Index), and the Short Physical Performance Battery for muscle strength and performance assessment were performed. Sarcopenia was defined as low muscle strength and low SMI or SI. RESULTS: A total of 157 patients were included, of which 68.8% had NAFLD, 66.2% low SMI, 50.3% low SI, 16.6% low performance and 11.5% low strength. In patients with NAFLD, prevalence of significant fibrosis by NFS was 15.7%. Low SMI was associated with presence of NAFLD when adjusted for age, sex, type 2 diabetes mellitus, hypertension, and dyslipidemia, but not for body mass index and waist circumference. Low SMI, low SI, and sarcopenia were associated with significant fibrosis in univariate analysis; the small number of events precluded a multivariable analysis. CONCLUSIONS: Low SMI was associated with NAFLD independently of demographics and comorbidities but not of other parameters of body composition. This contrasts with most studies published on this matter.


Assuntos
Diabetes Mellitus Tipo 2 , Hepatopatia Gordurosa não Alcoólica , Sarcopenia , Humanos , Hepatopatia Gordurosa não Alcoólica/complicações , Hepatopatia Gordurosa não Alcoólica/diagnóstico , Hepatopatia Gordurosa não Alcoólica/epidemiologia , Sarcopenia/diagnóstico por imagem , Sarcopenia/etiologia , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/patologia , Músculo Esquelético/patologia , Fibrose
19.
Ecol Evol ; 13(4): e10009, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37091572

RESUMO

Angiosperms present an astonishing diversity of genome sizes that can vary intra- or interspecifically. The remarkable new cytogenomic data shed some light on our understanding of evolution, but few studies were performed with insular and mainland populations to test possible correlations with dispersal, speciation, and adaptations to insular environments. Here, patterns of cytogenomic diversity were assessed among geographic samples (ca. 114) of Crithmum maritimum (Apiaceae), collected across the Azores and Madeira archipelagos, as well as in adjacent continental areas of Portugal. Using flow cytometry, the results indicated a significant intraspecific genome size variation, spanning from reduced sizes in the insular populations to larger ones in the mainland populations. Moreover, there was a tendency for an increase in genome size along the mainland populations, associated with lower temperatures, higher precipitation, and lower precipitation seasonality. However, this gradient might be the result of historic phylogeographical events associated with previous dispersal and extinction of local populations. Overall, our findings provided evidence that smaller genome sizes might play a critical role in the colonization of islands, corroborating other studies that argue that organisms with smaller genomes use fewer resources, having a selective advantage under insular environments. Although further studies are needed to improve our understanding of the mechanisms underlying genome size evolution on islands, conservation strategies must be promoted to protect the rich cytogenomic diversity found among C. maritimum populations, which occur in coastal areas that are particularly threatened by human activity, pollution, invasive species, and climate changes.

20.
Neurochem Res ; 37(4): 749-58, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22160748

RESUMO

Rut-bpy is a novel nitrosyl-ruthenium complex releasing NO into the vascular system. We evaluated the effect of Rut-bpy (100 mg/kg) on a rat model of brain stroke. Forty rats were assigned to four groups (Saline solution [SS], Rut-bpy, SS+ischemia-reperfusion [SS+I/R] and Rut-bpy+ischemia-reperfusion [Rut-bpy+I/R]) with their mean arterial pressure (MAP) continuously monitored. The groups were submitted (SS+I/R and Rut-bpy+I/R) or not (SS and Rut-bpy) to incomplete global brain ischemia by occlusion of the common bilateral carotid arteries during 30 min followed by reperfusion for further 60 min. Thirty minutes before ischemia, rats were treated pairwise by intraperitoneal injection of saline solution or Rut-bpy. At the end of experiments, brain was removed for triphenyltetrazolium chloride staining in order to quantify the total ischemic area. In a subset of rats, hippocampus was obtained for histopathology scoring, nitrate and nitrite measurements, immunostaining and western blotting of the nuclear factor- κB (NF-κB). Rut-bpy pre-treatment decreased MAP variations during the transition from brain ischemia to reperfusion and decreased the fractional injury area. Rut-bpy pre-treatment reduced NF-κB hippocampal immunostaining and protein expression with improved histopathology scoring as compared to the untreated operated control. In conclusion, Rut-bpy improved the total brain infarction area and hippocampal neuronal viability in part by inhibiting NF-κB signaling and helped to stabilize the blood pressure during the transition from ischemia to reperfusion.


Assuntos
Anestesia , Isquemia Encefálica/prevenção & controle , Precondicionamento Isquêmico/métodos , Doadores de Óxido Nítrico/administração & dosagem , Traumatismo por Reperfusão/prevenção & controle , Compostos de Rutênio/administração & dosagem , Anestesia/métodos , Animais , Encéfalo/irrigação sanguínea , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Isquemia Encefálica/metabolismo , Isquemia Encefálica/fisiopatologia , Masculino , Fármacos Neuroprotetores/administração & dosagem , Ratos , Ratos Wistar , Espécies Reativas de Nitrogênio/metabolismo , Traumatismo por Reperfusão/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA