Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.122
Filtrar
1.
J Comp Pathol ; 212: 32-41, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38971022

RESUMO

White-tailed antsangies (Brachytarsomys albicauda) are Madagascan rodents uncommonly kept in captivity. Hymenolepis nana is a cestode with an unusual life cycle, incorporating direct, indirect and autoinfective stages. This case series represents the first reported outbreak of H. nana cestodiasis in white-tailed antsangies, summarizing macroscopic and histological findings in four cases. On post-mortem examination (PME), numerous cysticerci were detected consistently throughout the intestinal serosa, liver, mesenteric lymphatic vasculature and mesenteric lymph nodes. Pancreatic cysticerci were observed in one case. Adult tapeworms, larvae and eggs were found only in the small intestine, and faecal egg shedding was a feature. Histopathological examination identified adult, larval and encysted cestodes within the respective gross lesions, with pulmonary, pancreatic and splenic involvement detected in a single case. The cestodes sampled on PME were identified by polymerase chain reaction and DNA sequencing, with H. nana confirmed in all cases. Visceral larva migrans was consistent throughout all specimens, in contrast with the natural infections of standard rodent hosts, and may be considered a likely pathological feature of H. nana infection in white-tailed antsangies.

2.
Int J Surg Case Rep ; 121: 109970, 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38981295

RESUMO

INTRODUCTION AND IMPORTANCE: Diabetic foot ulcers are a prevalent and challenging issue among diabetes patients, frequently leading to notable health concerns and reduced quality of life. Effectively addressing diabetic foot ulcers necessitates a comprehensive treatment strategy. CASE PRESENTATION: The 69-year-old patient with Type 2 diabetes, complicated by illiteracy and poor glycemic control, developed a foot wound that escalated to cellulitis and abscess due to diabetes and peripheral vascular disease. After angioplasty and midfoot amputation, treatment focused on wound healing with antibiotics, local anesthesia, larval therapy, vacuum-assisted closure (VAC), platelet-rich plasma (PRP) injections, and specialized dressings. A multidisciplinary team approach facilitated successful wound healing and functional improvement, highlighting the importance of comprehensive care and innovative treatments in complex diabetic foot ulcers. DISCUSSION: Diabetic foot ulcers, a frequent complication of diabetes, present notable hurdles in treatment and care. Comprehensive strategies are typically essential for managing these ulcers efficiently and averting additional issues. Recently, there has been increasing attention towards employing various dressing techniques, maggot therapy, and vacuum therapy as integral components of a holistic diabetic foot ulcer treatment approach. CONCLUSION: Employing a comprehensive method involving various dressing techniques, maggot therapy, and vacuum therapy for diabetic foot ulcers can significantly boost wound healing, curb infections, and lower the chances of additional complications.

3.
Dokl Biochem Biophys ; 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38955916

RESUMO

We performed a detailed ultrastructural reconstruction of the "passive" miracidium of Derogenes varicus Muller, 1784 , a species from Hemiurata group. The miracidium is highly miniaturized and simplified in comparison with the "active" miracidia. For the first time we elucidate the nature of the spines on the surface of hemiuroid larva: they are derivatives of the epithelial plates. The anterior end of the larva is equipped with three epithelial plates that bear both spines and cilia. The major part of the miracidial surface is formed by tegument. The nervous and excretory systems of the D. varicus miracidium are extremely reduced. Single undifferentiated cell comprises the germinal material of the miracidium. We discuss the trends of evolution of hemiuroid miracidia that are associated with transition to passive strategy of infection.

5.
Biochem Biophys Res Commun ; 727: 150290, 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38941792

RESUMO

To understand neural basis of animal behavior, it is necessary to monitor neural activity and behavior in freely moving animal before building relationship between them. Here we use light sheet fluorescence microscope (LSFM) combined with microfluidic chip to simultaneously capture neural activity and body movement in small freely behaving Drosophila larva. We develop a transfer learning based method to simultaneously track the continuously changing body posture and activity of neurons that move together using a sub-region tracking network with a precise landmark estimation network for the inference of target landmark trajectory. Based on the tracking of each labelled neuron, the activity of the neuron indicated by fluorescent intensity is calculated. For each video, annotation of only 20 frames in a video is sufficient to yield human-level accuracy for all other frames. The validity of this method is further confirmed by reproducing the activity pattern of PMSIs (period-positive median segmental interneurons) and larval movement as previously reported. Using this method, we disclosed the correlation between larval movement and left-right asymmetry in activity of a group of unidentified neurons labelled by R52H01-Gal4 and further confirmed the roles of these neurons in bilateral balance of body contraction during larval crawling by genetic inhibition of these neurons. Our method provides a new tool for accurate extraction of neural activities and movement of freely behaving small-size transparent animals.

6.
Korean J Gastroenterol ; 83(6): 247-252, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38918038

RESUMO

Toxocariasis, a zoonotic infection transmitted by Toxocara canis (from dogs) and Toxocara cati (from cats) larvae, poses rare but severe risks to humans. We present a case of hepatic visceral larva migrans (VLM) caused by Toxocara canis in a 21-year-old male with a history of close contact with a pet dog. Initial symptoms and imaging findings mimicked a pyogenic liver abscess. The initial laboratory investigations revealed neutrophilia and elevated levels of IgE. Despite broad-spectrum antibiotics, persistent fever prompted further investigation. Subsequent serological testing for Toxocara antibodies and histopathological analysis of liver tissue demonstrating eosinophil infiltrates and Charcot-Leyden crystals led to a confirmed diagnosis of a liver abscess caused by Toxocara canis. Serological testing for Toxocara antibodies and histopathological analysis of liver tissue confirmed a Toxocara canis-induced liver abscess. Albendazole treatment yielded significant clinical improvement. This case highlights the necessity of considering toxocariasis in liver abscess differentials, particularly in high-seroprevalence regions like Vietnam. Relying solely on serological tests may be insufficient, emphasizing the need for corroborative evidence, including invasive procedures like liver biopsy, for accurate hepatic toxocariasis diagnosis.


Assuntos
Albendazol , Larva Migrans Visceral , Tomografia Computadorizada por Raios X , Toxocara canis , Humanos , Toxocara canis/isolamento & purificação , Larva Migrans Visceral/diagnóstico , Larva Migrans Visceral/tratamento farmacológico , Masculino , Animais , Adulto Jovem , Albendazol/uso terapêutico , Cães , Fígado/parasitologia , Fígado/patologia , Anticorpos Anti-Helmínticos/sangue , Ultrassonografia , Abscesso Hepático/diagnóstico , Abscesso Hepático/parasitologia , Abscesso Hepático/tratamento farmacológico , Toxocaríase/diagnóstico , Toxocaríase/tratamento farmacológico , Imunoglobulina E/sangue , Anti-Helmínticos/uso terapêutico
7.
Parasites Hosts Dis ; 62(2): 243-250, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38835265

RESUMO

We investigated organ specific Toxocara canis larval migration in mice infected with T. canis larvae. We observed the worm burden and systemic immune responses. Three groups of BALB/c mice (n=5 each) were orally administered 1,000 T. canis 2nd stage larvae to induce larva migrans. Mice were sacrificed at 1, 3, and 5 weeks post-infection. Liver, lung, brain, and eye tissues were collected. Tissue from 2 mice per group was digested for larval count, while the remaining 3 mice underwent histological analysis. Blood hematology and serology were evaluated and compared to that in a control uninfected group (n=5) to assess the immune response. Cytokine levels in bronchoalveolar lavage (BAL) fluid were also analyzed. We found that, 1 week post-infection, the mean parasite load in the liver (72±7.1), brain (31±4.2), lungs (20±5.7), and eyes (2±0) peaked and stayed constant until the 3 weeks. By 5-week post-infection, the worm burden in the liver and lungs significantly decreased to 10±4.2 and 9±5.7, respectively, while they remained relatively stable in the brain and eyes (18±4.2 and 1±0, respectively). Interestingly, ocular larvae resided in all retinal layers, without notable inflammation in outer retina. Mice infected with T. canis exhibited elevated levels of neutrophils, monocytes, eosinophils, and immunoglobulin E. At 5 weeks post-infection, interleukin (IL)-5 and IL-13 levels were elevated in BAL fluid. Whereas IL-4, IL-10, IL-17, and interferon-γ levels in BAL fluid were similar to that in controls. Our findings demonstrate that a small portion of T. canis larvae migrate to the eyes and brain within the first week of infection. Minimal tissue inflammation was observed, probably due to increase of anti-inflammatory cytokines. This study contributes to our understanding of the histological and immunological responses to T. canis infection in mice, which may have implications to further understand human toxocariasis.


Assuntos
Encéfalo , Citocinas , Larva , Fígado , Pulmão , Camundongos Endogâmicos BALB C , Toxocara canis , Toxocaríase , Animais , Toxocara canis/imunologia , Toxocaríase/imunologia , Toxocaríase/patologia , Toxocaríase/parasitologia , Larva/imunologia , Camundongos , Citocinas/metabolismo , Pulmão/parasitologia , Pulmão/imunologia , Pulmão/patologia , Fígado/parasitologia , Fígado/patologia , Fígado/imunologia , Encéfalo/parasitologia , Encéfalo/imunologia , Encéfalo/patologia , Líquido da Lavagem Broncoalveolar/imunologia , Líquido da Lavagem Broncoalveolar/parasitologia , Feminino , Carga Parasitária , Olho/parasitologia , Olho/imunologia , Olho/patologia , Modelos Animais de Doenças
8.
Behav Brain Res ; 471: 115074, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38825023

RESUMO

The tail plays important roles in locomotion control in many animals. But in animals with multiple body segments, the roles of the hind body segments and corresponding innervating neurons in locomotion control are not clear. Here, using the Drosophila larva as the model animal, we investigated the roles of the posterior terminal segments in various modes of locomotion and found that they participate in all of them. In forward crawling, paralysis of the larval tail by blocking the Abdb-Gal4 labeled neurons in the posterior segments of VNC led to a slower locomotion speed but did not prevent the initiation of forward peristalsis. In backward crawling, larvae with the Abdb-Gal4 neurons inhibited were unable to generate effective displacement although waves of backward peristalsis could be initiated and persist. In head swing where the movement of the tail is not obvious, disabling the larval tail by blocking Abdb-Gal4 neurons led to increased bending amplitude upon touching the head. In the case of larval lateral rolling, larval tail paralysis by inhibition of Abdb-Gal4 neurons did not prevent the accomplishment of rolling, but resulted in slower rolling speed. Our work reveals that the contribution of Drosophila larval posterior VNC segments and corresponding body segments in the tail to locomotion is comprehensive but could be compensated at least partially by other body segments. We suggest that the decentralization in locomotion control with respect to animal body parts helps to maintain the robustness of locomotion in multi-segment animals.

9.
Parasit Vectors ; 17(1): 256, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38867315

RESUMO

BACKGROUND: Human toxocariasis is a neglected parasitic disease characterised by the syndromes visceral, cerebral, and ocular larva migrans. This disease is caused by the migrating larvae of Toxocara roundworms from dogs and cats, affecting 1.4 billion people globally. Via extracellular vesicles (EVs), microRNAs have been demonstrated to play roles in host-parasite interactions and proposed as circulating biomarkers for the diagnosis and follow-up of parasitic diseases. METHODS: Small RNA-seq was conducted to identify miRNAs in the infective larvae of T. canis and plasma EV-containing preparations of infected BALB/c mice. Differential expression analysis and target prediction were performed to indicate miRNAs involved in host-parasite interactions and miRNAs associated with visceral and/or cerebral larva migrans in the infected mice. Quantitative real-time polymerase chain reaction (PCR) was used to amplify circulating miRNAs from the infected mice. RESULTS: This study reports host and parasite miRNAs in the plasma of BALB/c mice with visceral and cerebral larva migrans and demonstrates the alterations of these miRNAs during the migration of larvae from the livers through the lungs and to the brains of infected mice. After filtering unspecific changes in an irrelevant control, T. canis-derived miRNAs and T. canis infection-induced differential miRNAs are predicted to modulate genes consistently involved in mitogen-activated protein kinase (MAPK) signalling and pathways regulating axon guidance and pluripotency of stem in the infected mice with visceral and cerebral larva migrans. For these plasma circulating miRNAs predicted to be involved in host-parasite crosstalk, two murine miRNAs (miR-26b-5p and miR-122-5p) are experimentally verified to be responsive to larva migrans and represent circulating biomarker candidates for visceral and cerebral toxocariasis in BALB/c mice. CONCLUSIONS: Our findings provide novel insights into the crosstalk of T. canis and the mammalian host via plasma circulating miRNAs, and prime agents and indicators for visceral and cerebral larva migrans. A deep understanding of these aspects will underpin the diagnosis and control of toxocariasis in humans and animals.


Assuntos
MicroRNA Circulante , Camundongos Endogâmicos BALB C , Toxocara canis , Toxocaríase , Animais , Toxocara canis/genética , Toxocara canis/fisiologia , Camundongos , Toxocaríase/parasitologia , Toxocaríase/sangue , MicroRNA Circulante/sangue , MicroRNA Circulante/genética , Interações Hospedeiro-Parasita , Larva Migrans Visceral/parasitologia , Larva Migrans Visceral/sangue , Feminino , Larva Migrans/parasitologia , Larva Migrans/sangue , Larva/genética , Cães , MicroRNAs/sangue , MicroRNAs/genética , Biomarcadores/sangue , Encéfalo/parasitologia
10.
Bio Protoc ; 14(11): e4996, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38873019

RESUMO

Many studies on mosquito biology rely on laboratory-reared colonies, emphasizing the need for standardized protocols to investigate critical aspects such as disease biology, mosquito behavior, and vector control methods. While much knowledge is derived from anthropophilic species from genera like Anopheles, Aedes, and Culex, there is a growing interest in studying mosquitoes that feed on non-human hosts. This interest stems from the desire to gain a deeper understanding of the evolution of diverse host range use and host specificity. However, there is currently a limited number of comprehensive protocols for studying such species. Considering this gap, we present a protocol for rearing Uranotaenia lowii, a mosquito species specialized in feeding on anuran amphibians by eavesdropping on host-emitted sound cues. Additionally, we provide instructions for successfully shipping live specimens to promote research on this species and similar ones. This protocol helps fill the current gap in comprehensive guidelines for rearing and maintaining colonies of anuran host-biting mosquitoes. It serves as a valuable resource for researchers seeking to establish colonies of mosquito species from the Uranotaeniini tribe. Ultimately, this protocol may facilitate research on the evolutionary ecology of Culicidae, as this family has recently been proposed to have originated from a frog-feeding ancestor. Key features • Rearing and maintenance of colonies of non-human host-biting mosquitoes that feed on frogs using host-emitted acoustic cues. • Provides shipping guidelines aimed to enhance the establishment of colonies by new research groups and specimen exchanges between labs.

11.
Indian J Med Microbiol ; 50: 100645, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38857756

RESUMO

We report an unusual case of strongyloidiasis in a 62-year-old male, presenting with fever, and acute diarrhea. The patients had concomitant bilateral renal parenchymal disease and carrier for Hepatitis B. Numerous motile larvae were observed in wet mount of the freshly passed stool. The patient responded well to oral ivermectin. Prompt and accurate diagnosis of strongyloidiasis can prevent the consequences associated with hyperinfective syndrome.

12.
Artigo em Inglês | MEDLINE | ID: mdl-38769629

RESUMO

AIM: Many fish species can harbour a wide range of pathogenic agents in their tissues. Of many pathogens, the parasitic nematode of genus Contracaecum, which resides in the tissues of fish species, can results in fish-borne infections in humans. This study was planned to assess consumers' awareness of fish-borne zoonoses in the fishing sites of Lake Chamo, Arba Minch, Ethiopia. The study was also aimed at demonstrating the zoonotic nematode, Contracaecum parasites in the Oreochromis niloticus and Lates niloticus fishes collected from Lake Chamo, Arba Minch, Ethiopia. METHODS AND RESULTS: Assessment of awareness about fish-borne zoonoses was conducted in randomly selected participants (n = 162) using face-to-face interviews via a structured and semi-structured questionnaire. Besides, 70 fishes (O. niloticus = 35 and L. niloticus = 35) were examined for the presence of larva of Contracaecum and other anisakid genera through standard dissection, pepsin-hydrochloric acid digestion and microscopic observation. Consumers have inadequate awareness about fish-borne zoonoses based on the answers they provided to the questions. The majority of respondents (82%) consume raw fish in the area. Of these, a significantly higher proportion were male (p < 0.001), completed their elementary or high school (p = 0.004), Orthodox Christian (p = 0.044), fishermen (p < 0.001) and participants without previous information about fish-borne zoonoses (p < 0.001). Overall, of examined fishes (n = 70), n = 15 (21.4%, 95% CI, 12.8-33.2) were infected with Contracaecum larva. A significant (p = 0.028) higher infection prevalence was noted in L. niloticus (34.3%, 95% CI, 19.7-52.3) compared to O. niloticus (8.6%, 95% CI, 2.2-24.2). A unit gram addition in the total weight of fish would significantly raise the risk of Contracaecum infection by 1% (p < 0.001). CONCLUSIONS: The presence of Contracaecum, a zoonotic nematode in the fishes, which are often preferred by consumers for raw dishes, designates a high risk of possible fish-borne infections in the area. Thus, providing education and training for fishermen, visitors of the area, and local people who visit the area for fish consumption, it is inevitably important to minimize the risk. Furthermore, health workers should suspect fish-borne infections, such as anisakidosis in patients who have a history of raw fish consumption in Arba Minch, Ethiopia.

13.
Insect Mol Biol ; 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38783592

RESUMO

Akirin is a nuclear protein that controls development in vertebrates and invertebrates. The function of Akirin has not been assessed in any Coleopteran insects. We found that high levels of akirin transcripts in Henosepilachna vigintioctopunctata, a serious Coleopteran potato defoliator (hereafter Hvakirin), were present at prepupal, pupal and adult stages, especially in larval foregut and fat body. RNA interference (RNAi) targeting Hvakirin impaired larval development. The Hvakirin RNAi larvae arrested development at the final larval instar stage. They remained as stunted larvae, gradually blackened and finally died. Moreover, the remodelling of gut and fat body was inhibited in the Hvakirin depleted larvae. Two layers of cuticles, old and newly formed, were noted in the dsegfp-injected animals. In contrast, only a layer of cuticle was found in the dsakirin-injected beetles, indicating the arrest of larval development. Furthermore, the expression of three transforming growth factor-ß cascade genes (Hvsmox, Hvmyo and Hvbabo), a 20-hydroxyecdysone (20E) receptor gene (HvEcR) and six 20E response genes (HvHR3, HvHR4, HvE75, HvBrC, HvE93 and Hvftz-f1) was significantly repressed, consistent with decreased 20E signalling. Conversely, the transcription of a juvenile hormone (JH) biosynthesis gene (Hvjhamt), a JH receptor gene (HvMet) and two JH response genes (HvKr-h1 and HvHairy) was greatly enhanced. Our findings suggest a critical role of Akirin in larval development in H. vigintioctopunctata.

15.
Parasite Epidemiol Control ; 25: e00351, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38708129

RESUMO

Human toxocariasis (HT) is a widespread zoonotic infection globally, notably prevalent in tropical areas. Enhancing our understanding of toxocariasis can lead to increased attention towards the socioeconomic impact and control of this neglected zoonosis. We conducted a comprehensive review of all available articles and official documents on toxocariasis in Iran to identify research gaps and critical needs for its control. This review highlights that despite numerous studies exploring various aspects of toxocariasis in definitive and paratenic hosts, as well as humans and environmental contamination, significant data deficiencies and gaps persist across different regions in the country. These gaps involve investigating the worm burden and reinfection rates in definitive hosts, developing more sensitive methods to detect and differentiate of Toxocara species, and understanding the behavior of definitive host animals. Additionally, identifying potential paratenic hosts for HT and exploring the organ-specific affinity and survival duration of Toxocara larvae within these hosts are essential areas for exploration. It's also imperative to comprehend the sylvatic and domestic cycles of the parasite in paratenic hosts. Furthermore, assessing egg density in the environment, exploring potential new sources such as water, and identifying regions with optimal climatic conditions for the survival and development of Toxocara eggs are crucial for the formulation of effective prevention and control strategies. Identifying at-risk groups, developing early diagnosis techniques, employing imaging methods, and identifying long-term complications in humans are also crucial. Community health organizations should prioritize health education for the public and professionals. Furthermore, accurately estimating definitive host populations, monitoring and preventing their movements in public places, implementing regular deworming practices for pets and stray hosts, and recognizing the infection's significance as a health priority are critical. This comprehensive understanding advocates for a holistic "one health" approach to control of HT.

16.
Trop Med Infect Dis ; 9(5)2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38787039

RESUMO

While conducting research in a protected ecological reserve within Ecuador's subtropical rainforest, a 49-year-old biologist, residing in an Andean city, contracted hookworm-related cutaneous larva migrans (Hr-CLM) in the vesiculobullous clinical form. Since there were no domestic dogs or cats in the reserve, it is likely that wild animals carrying Ancylostoma sp. larvae infected the patient. She was effectively treated with two doses of oral ivermectin, administered 31 days after getting the infection. This case was diagnosed in a temperate city; therefore, a comprehensive travel history and clinical assessments are crucial for an accurate diagnosis and timely treatment.

17.
Chemosphere ; 358: 142105, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38657690

RESUMO

Di(2-ethylhexyl) terephthalate (DEHTP) is an alternative plasticizer widely used in numerous consumer products, replacing di(2-ethylhexyl) phthalate (DEHP). Hence, DEHTP has been frequently detected in the environment and humans. As a structural isomer and functional analog of DEHP, DEHTP is a suspected endocrine disruptor. Here, we evaluated thyroid-disrupting effects of DEHTP using embryo-larval and adult male zebrafish. We also investigated its sex hormone disruption potential in the adult zebrafish. After 5- and 7-days of exposure to DEHTP, significant increases in whole-body thyroid hormonal levels were observed in the larval fish. Down-regulation of several thyroid-regulating genes, including trh, tshß, nis, and dio2, was observed, but only after 5-day exposure. Following a 21-day exposure, the adult male zebrafish exhibited a significant decrease in total triiodothyronine and an increase in thyroid-stimulating hormones. Potential changes in the deiodination of thyroid hormones, supported by the up-regulation of two deiodinases, dio1 and dio3a, along with the down-regulation of dio2, could explain the thyroid hormone changes in the adult zebrafish. Moreover, significant trends of decrease in estradiol and 11-ketotestosterone, along with increase of testosterone (T), were observed in the adult zebrafish. Up-regulation of several steroidogenic genes may explain elevated T, while exact mechanisms of action warrant further investigation. Our results demonstrate that DEHTP can cause disruptions of thyroid and sex hormones at different life stages in zebrafish.


Assuntos
Disruptores Endócrinos , Glândula Tireoide , Hormônios Tireóideos , Peixe-Zebra , Animais , Masculino , Disruptores Endócrinos/toxicidade , Glândula Tireoide/efeitos dos fármacos , Glândula Tireoide/metabolismo , Hormônios Tireóideos/metabolismo , Hormônios Esteroides Gonadais/metabolismo , Plastificantes/toxicidade , Larva/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Ácidos Ftálicos/toxicidade , Tri-Iodotironina , Dietilexilftalato/toxicidade , Dietilexilftalato/análogos & derivados
18.
Front Neurosci ; 18: 1375208, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38586190

RESUMO

Introduction: Neurodevelopment in larval stages of non-model organisms, with a focus on the serotonin- and FMRFamide-immunoreactive components, has been in the focus of research in the recent past. However, some taxonomic groups remain understudied. Nemertea (ribbon worms) represent such an understudied clade with only few reports on nervous system development mostly from phylogenetically or developmentally derived species. It would be insightful to explore neurodevelopment in additional species to be able to document the diversity and deduce common patterns to trace the evolution of nervous system development. Methods: Fluorescent immunohistochemical labeling with polyclonal primary antibodies against serotonin and FMRF-amide and a monoclonal antibody against synapsin performed on series of fixed larval stages of two nemertean species Cephalothrix rufifrons (Archinemertea, Palaeonemertea) and Emplectonema gracile (Monostilifera, Hoplonemertea) were analyzed with confocal laser scanning microscopy. Results: This contribution gives detailed accounts on the development of the serotonin- and FMRFamide-immunoreactive subsets of the nervous system in two nemertean species from the first appearance of the respective signals. Additionally, data on synapsin-like immunoreactivity illustrates the general structure of neuropil components. Events common to both investigated species are the appearance of serotonin-like immunoreactive signals before the appearance of FMRF-like immunoreactive signals and the strict progression of the development of the lateral nerve cords from the anteriorly located, ring-shaped brain toward the posterior pole of the larva. Notable differences are (1) the proboscis nervous system that is developing much earlier in investigated larval stages of E. gracile and (2) distinct early, but apparently transient, serotonergic neurons on the frontal and caudal pole of the larva in E. gracile that seem to be absent in C. rufifrons. Discussion: According to the results from this investigation and in line with previously published accounts on nervous system development, the hypothetical last common ancestor of Nemertea had a ring-shaped brain arranged around the proboscis opening, from which a pair of ventro-lateral nerve cords develops in anterior to posterior progression. Early frontal and caudal serotonergic neurons that later degenerate or cease to express serotonin are an ancestral character of Nemertea that they share with several other spiralian clades.

19.
J Comp Physiol B ; 2024 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-38584182

RESUMO

The fish gill is a multifunctional organ that is important in multiple physiological processes such as gas transfer, ionoregulation, and chemoreception. This characteristic organ of fishes has received much attention, yet an often-overlooked point is that larval fishes in most cases do not have a fully developed gill, and thus larval gills do not function identically as adult gills. In addition, large changes associated with gas exchange and ionoregulation happen in gills during the larval phase, leading to the oxygen and ionoregulatory hypotheses examining the environmental constraint that resulted in the evolution of gills. This review thus focuses exclusively on the larval fish gill of teleosts, summarizing the development of teleost larval fish gills and its function in gas transfer, ionoregulation, and chemoreception, and comparing and contrasting it to adult gills where applicable, while providing some insight into the oxygen vs ionoregulatory hypotheses debate.

20.
Oxf Med Case Reports ; 2024(4): omae025, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38680772

RESUMO

BACKGROUND: Cutaneous Larva Migrans (CLM) is one of the most common zoonotic dermatoses in subtropical and tropical regions and some European countries. It is caused by different types of hookworm, such as Ancylostoma braziliense, Ancylostoma caninum, and Uncinaria stenocephala. It is usually easy to diagnose, but the atypical presentation may occasionally mimic other dermatoses. CASE REPORT: A 32-year-old man presented with an extensive eczematous rash that developed during a recent vacation in Thailand. He didn't respond to antihistamines and systemic steroids. Finally, he was diagnosed with an atypical presentation of CLM and treated successfully with anthelminthic therapy. CONCLUSION: The report of an atypical presentation of CLM is crucial to increase awareness among healthcare workers, helping in early diagnosis and reducing potential psychological distress that patients may face.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...