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1.
Braz. j. biol ; 84: e252088, 2024. tab
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1345543

RESUMO

Abstract Acacia mangium is a pioneer species with fast growth and frequently used in the recovery of degraded areas. The objectives were to evaluate insects and spiders, their ecological indices and interactions on A. mangium saplings in a tropical degraded area in recovering process. The experimental design was completely randomized with 24 replications, with treatments represented by the first and second years after A. mangium seedling planted. Numbers of leaves/branch, branches/sapling, and ground cover by A. mangium saplings, Hemiptera: Phenacoccus sp. and Pachycoris torridus; Hymenoptera: Tetragonisca angustula and Trigona spinipes, Brachymyrmex sp., Camponotus sp. and Cephalotes sp.; Blattodea: Nasutitermes sp. and Neuroptera: Chrysoperla sp.; abundance, species richness of pollinating insects, tending ants, and the abundance of Sternorrhyncha predators were greatest in the second year after planting. Numbers of Hemiptera: Aethalium reticulatum, Hymenoptera: Camponotus sp., Cephalotes sp., Polybia sp., T. angustula, T. spinipes, tending ants, pollinating insects, Sternorrhyncha predators and species richness of tending ants were highest on A. mangium saplings with greatest numbers of leaves or branches. The increase in the population of arthropods with ground cover by A. mangium saplings age increase indicates the positive impact by this plant on the recovery process of degraded areas.


Resumo Acacia mangium é uma espécie pioneira, de rápido crescimento e utilizada na recuperação de áreas degradadas. Os objetivos foram avaliar insetos e aranhas, seus índices ecológicos e interações com plantas de A. mangium em área tropical degradada em processo de recuperação. O delineamento experimental foi inteiramente casualizado com 24 repetições, com os tratamentos representados pelos primeiro e segundo anos após a plantio de A. mangium. Os números de folhas/galhos, galhos/plantas e cobertura do solo por plantas de A. mangium, de Hemiptera: Phenacoccus sp. e Pachycoris torridus; Hymenoptera: Tetragonisca angustula e Trigona spinipes, Brachymyrmex sp., Camponotus sp. e Cephalotes sp.; Blattodea: Nasutitermes sp. e Neuroptera: Chrysoperla sp.; a abundância, riqueza de espécies de insetos polinizadores, formigas cuidadoras e a abundância de predadores de Sternorrhyncha foram maiores no segundo ano após o plantio. Os números de Hemiptera: Aethalium reticulatum, Hymenoptera: Camponotus sp., Cephalotes sp., Polybia sp., T. angustula, T. spinipes, formigas cuidadoras, insetos polinizadores, predadores de Sternorrhyncha e a riqueza de espécies de formigas cuidadoras foram maiores em plantas de A. mangium com maior altura e número de folhas ou galhos. O aumento populacional de artrópodes e da cobertura do solo com o processo de envelhecimento das plantas de A. mangium indicam impacto positivo dessa planta na recuperação de áreas degradadas.


Assuntos
Animais , Aranhas , Acacia , Insetos , Biomarcadores Ambientais , Recuperação e Remediação Ambiental
3.
Zool Res ; 44(1): 43-52, 2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36266934

RESUMO

Lycosidae females demonstrate meticulous maternal care of offspring by carrying egg sacs and juvenile spiderlings during the reproductive stage. Nuclear receptors (NRs), especially the ecdysone receptor (EcR) and ultraspiracle (USP), have attracted considerable attention in the regulation of arthropod development and reproduction due to their pivotal roles in ecdysteroid signaling cascades. In the present study, 23 NRs, including one EcR and two USPs, were identified in the genome of the predatory wolf spider Pardosa pseudoannulata. RNA interference (RNAi) targeting EcR and USP-1 inhibited spiderling development and resulted in non-viable eggs in the egg sacs. EcR and USP-1 responded to changes in ecdysteroid levels, and interference in ecdysteroid biosynthesis led to similar phenotypes as dsEcR and dsUSP-1 treatments. These findings suggest that EcR/USP-1-mediated ecdysteroid signaling regulates P. pseudoannulata development and reproduction. The P. pseudoannulata females with suppressed ecdysteroid signaling proactively consumed their non-viable egg sacs, resulting in a 7.19 d shorter first reproductive cycle than the controls. Termination of the failed reproductive cycle enabled the spiders to produce a new egg sac more rapidly. This reproductive strategy may partially rescue the reduction in population growth due to non-viable eggs and compensate for the physiological expenditure of wasted maternal care, which would be beneficial for the conservation of P. pseudoannulata populations and their natural control of insect pests.


Assuntos
Ecdisteroides , Aranhas , Feminino , Animais , Aranhas/genética , Reprodução , Transdução de Sinais
4.
Gene ; 850: 146925, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36191823

RESUMO

Spiders (Araneae) are the most abundant terrestrial predators and megadiverse on earth. In recent years, the mitochondrial genome of a great diversity of species has been sequenced, mainly for ecological and commercial purposes. These studies have uncovered the existence of a variety of mitochondrial genome rearrangements. However, there is poor genetic information in several taxonomic families of spiders. We have sequenced the complete genome of Phoneutria depilata (Ctenidae) and, based on this, extract the mitogenomes of other ctenid species from published transcriptomes to perform a comparative study among spider species to determine the relationship between the level of mitochondrial rearrangements and its possible relationship with molecular variability in spiders. Complete mitochondrial genomes of eighteen spiders (including eight Ctenidae species) were obtained by two different methodologies (sequencing and transcriptome extraction). Fifty-eight spider mitochondrial genomes were downloaded from the NCBI database for gene order analysis. After verifying the annotation of each mitochondrial gene, a phylogenetic and a gene order analysis from 76 spider mitochondrial genomes were carried out. Our results show a high rate of annotation error in the published spider mitochondrial genomes, which could lead to errors in phylogenetic inference. Moreover, to provide new mitochondrial genomes in spiders by two different methodologies to obtain them, our analysis identifies six different mitochondrial architectures among all spiders. Translocation or tandem duplication random loss (TDRL) events in tRNA genes were identified to explain the evolution of the spider mitochondrial genome. In addition, our findings provide new insights into spider mitochondrial evolution.


Assuntos
Genoma Mitocondrial , Aranhas , Animais , Aranhas/genética , Filogenia , Genes Mitocondriais , RNA de Transferência/genética
5.
Sci Total Environ ; 855: 158658, 2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36113799

RESUMO

Freshwater systems have undergone drastic alterations during the last century, potentially affecting cross-boundary resource transfers between aquatic and terrestrial ecosystems. One important connection is the export of biomass by emergent aquatic insects containing omega-3 polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acid (EPA), that is scarce in terrestrial systems. Because of taxon-specific differences in PUFA content and functional traits, the contribution of different insect groups should be considered, in addition to total biomass export. In this context, one important trait is the emergence mode. Stoneflies, in contrast to other aquatic insects, crawl to land to emerge instead of flying directly from the water surface, making them accessible to ground-dwelling predators. Because stoneflies are especially susceptible to environmental change, stream degradation might cause a mismatch of available and required nutrients, particularly for ground-dwelling predators. In this study, we estimated emergent biomass and EPA export along two streams with different levels of habitat degradation. The EPA content in aquatic insects did not differ with different degrees of habitat degradation and total biomass export in spring was with 7.9 ± 9.6 mg m-2 day-1 in the degraded and 7.3 ± 8.5 mg m-2 day-1 in the natural system, also unaffected. However, habitat degradation substantially altered the contribution of crawling emergence to the total export in spring, with no biomass export by stoneflies at the most degraded sites. The EPA content in ground-dwelling spiders was correlated with emergent stonefly biomass, making up only 16.0 ± 6.2 % of total fatty acids at sites with no stonefly emergence, but 27.3 ± 3.0 % at sites with highest stonefly emergence. Because immune function in ground-dwelling spiders has been connected to EPA levels, reduced crawling emergence might impact spider fitness. Functional traits, like emergence mode as well as nutritional quality, should be considered when assessing the effects of stream degradation on adjacent terrestrial ecosystems.


Assuntos
Aranhas , Animais , Ecossistema , Insetos , Biomassa , Estações do Ano , Cadeia Alimentar
8.
Sci Rep ; 12(1): 19045, 2022 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-36351940

RESUMO

Spider webs are finely tuned multifunctional structures, widely studied for their prey capture functionalities such as impact strength and stickiness. However, they are also sophisticated sensing tools that enable the spider to precisely determine the location of impact and capture the prey before it escapes. In this paper, we suggest a new mechanism for this detection process, based on potential modal analysis capabilities of the spider, using its legs as distinct distributed point sensors. To do this, we consider a numerical model of the web structure, including asymmetry in the design, prestress, and geometrical nonlinearity effects. We show how vibration signals deriving from impacts can be decomposed into web eigenmode components, through which the spider can efficiently trace the source location. Based on this numerical analysis, we discuss the role of the web structure, asymmetry, and prestress in the imaging mechanism, confirming the role of the latter in tuning the web response to achieve an efficient prey detection instrument. The results can be relevant for efficient distributed impact sensing applications.


Assuntos
Seda , Aranhas , Animais , Seda/química , Vibração , Comportamento Predatório/fisiologia , Aranhas/fisiologia
9.
Int J Mol Sci ; 23(21)2022 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-36361611

RESUMO

Pardosa pseudoannulata (P. pseudoannulata) is an essential natural predatory enemy in rice ecosystems. The fluctuating climate may cause them to experience heat stress, whereas heat shock proteins (HSPs) and antioxidant enzymes help resist heat damage. Herein, we cloned and characterized the full-length genes PpHSP27, PpHSP60, and PpHSC70 from P. pseudoannulata. Changes in gene expression levels and superoxide dismutase (SOD), catalase (CAT), and glutathione transferase (GST) activities in adult male and female P. pseudoannulata were measured at different stress exposure times and temperatures. We found that the abovementioned HSP genes belong to the sHSP, HSP60, and HSP70 families. The expression of the three HSP genes and the activities of SOD, CAT, and GST were significantly upregulated with the increasing stress temperature and time. The knockdown of the three HSP genes via RNA interference significantly decreased the survival rate of male and female P. pseudoannulata during high temperature stress. Thus, PpHSP27, PpHSP60, and PpHSC70 play an important role in the heat tolerance of P. pseudoannulata, and SOD, CAT, and GST enable recovery heat stress-induced oxidative damage. Their changes and regulation during high temperature stress can improve spiders' adaptability in the field and enhance the biological control of environmental pests.


Assuntos
Antioxidantes , Aranhas , Feminino , Masculino , Animais , Antioxidantes/metabolismo , Temperatura , Proteínas de Choque Térmico/genética , Ecossistema , Aranhas/genética , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo
10.
Int J Mol Sci ; 23(21)2022 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-36361863

RESUMO

Australian funnel-web spiders are amongst the most dangerous venomous animals. Their venoms induce potentially deadly symptoms, including hyper- and hypotension, tachycardia, bradycardia and pulmonary oedema. Human envenomation is more frequent with the ground-dwelling species, including the infamous Sydney funnel-web spider (Atrax robustus); although, only two tree-dwelling species induce more severe envenomation. To unravel the mechanisms that lead to this stark difference in clinical outcomes, we investigated the venom transcriptome and proteome of arboreal Hadronyche cerberea and H. formidabilis. Overall, Hadronyche venoms comprised 44 toxin superfamilies, with 12 being exclusive to tree-dwellers. Surprisingly, the major venom components were neprilysins and uncharacterized peptides, in addition to the well-known ω- and δ-hexatoxins and double-knot peptides. The insecticidal effects of Hadronyche venom on sheep blowflies were more potent than Atrax venom, and the venom of both tree- and ground-dwelling species potently modulated human voltage-gated sodium channels, particularly NaV1.2. Only the venom of tree-dwellers exhibited potent modulation of voltage-gated calcium channels. H. formidabilis appeared to be under less diversifying selection pressure compared to the newly adapted tree-dweller, H. cerberea. Thus, this study contributes to unravelling the fascinating molecular and pharmacological basis for the severe envenomation caused by the Australian tree-dwelling funnel-web spiders.


Assuntos
Venenos de Aranha , Aranhas , Animais , Humanos , Venenos de Aranha/toxicidade , Venenos de Aranha/química , Árvores , Austrália , Peptídeos
11.
Curr Biol ; 32(22): R1252-R1259, 2022 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-36413964

RESUMO

Structures created by animals can serve many purposes. Spiders weave intricate webs to trap prey; beavers engineer complex networks of dams to alter waterways; male bower birds construct and decorate elaborate bowers to attract mates. Animal architecture ranges widely in function, but by far the most common use is shelter. Animals can spend a large amount of time in their shelters, and this is often where they both sleep and rear young, two of the most vulnerable states in animal lives. To optimize the safety and suitability of refuges available to them, many animals have become architects and create their own shelters, ranging from simple holes in the ground to the large complex nests of some social insects.


Assuntos
Quirópteros , Aranhas , Animais , Masculino , Aves
12.
Nat Commun ; 13(1): 7082, 2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36400765

RESUMO

Many bacteria in nature exist in multicellular communities termed biofilms, where cells are embedded in an extracellular matrix that provides rigidity to the biofilm and protects cells from chemical and mechanical stresses. In the Gram-positive model bacterium Bacillus subtilis, TasA is the major protein component of the biofilm matrix, where it has been reported to form functional amyloid fibres contributing to biofilm structure and stability. Here, we present electron cryomicroscopy structures of TasA fibres, which show that, rather than forming amyloid fibrils, TasA monomers assemble into fibres through donor-strand exchange, with each subunit donating a ß-strand to complete the fold of the next subunit along the fibre. Combining electron cryotomography, atomic force microscopy, and mutational studies, we show how TasA fibres congregate in three dimensions to form abundant fibre bundles that are essential for B. subtilis biofilm formation. Our study explains the previously observed biochemical properties of TasA and shows how a bacterial extracellular globular protein can assemble from monomers into ß-sheet-rich fibres, and how such fibres assemble into bundles in biofilms.


Assuntos
Bacillus subtilis , Aranhas , Animais , Bacillus subtilis/metabolismo , Biofilmes , Proteínas de Bactérias/metabolismo , Amiloide/metabolismo , Aranhas/metabolismo
13.
Nat Commun ; 13(1): 6967, 2022 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-36414623

RESUMO

The transition from solitary to social life is a major phenotypic innovation, but its genetic underpinnings are largely unknown. To identify genomic changes associated with this transition, we compare the genomes of 22 spider species representing eight recent and independent origins of sociality. Hundreds of genes tend to experience shifts in selection during the repeated transition to social life. These genes are associated with several key functions, such as neurogenesis, behavior, and metabolism, and include genes that previously have been implicated in animal social behavior and human behavioral disorders. In addition, social species have elevated genome-wide rates of molecular evolution associated with relaxed selection caused by reduced effective population size. Altogether, our study provides unprecedented insights into the genomic signatures of social evolution and the specific genetic changes that repeatedly underpin the evolution of sociality. Our study also highlights the heretofore unappreciated potential of transcriptomics using ethanol-preserved specimens for comparative genomics and phylotranscriptomics.


Assuntos
Aranhas , Animais , Humanos , Aranhas/genética , Genômica , Evolução Molecular , Comportamento Social , Densidade Demográfica
14.
Int J Biol Macromol ; 222(Pt B): 2603-2614, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36270397

RESUMO

Superhydrophilic and underwater superoleophobic membranes have recently attracted significant interest as materials for effective oil-water emulsion separation. In this work, a superwetting membrane with a spider web structured gel layer was designed for efficient oil-water separation. Biomaterial, carboxymethyl cellulose (CMC), was used as the raw material, a spider web structured gel layer was constructed on the PVDF membrane surface by heat-treatment and chemical cross-linking. The hydrophilic gel layer imparted excellent superhydrophilic and underwater superoleophobic properties to the membrane, while the special spider web structure improved the membrane mechanical stability. The fabricated membrane exhibited superhydrophilicity and underwater superoleophobicity. Among different CMC concentration-modified membranes, the M-0.5 membrane containing 0.5 wt% CMC exhibited a flux of 612 L·m-2 h-1 during dichloromethane oil-water emulsion separation, which was 4.2-fold higher than that of the pristine PVDF membrane, while the membrane showed efficient oil-water separation capacity. Additionally, the water flux recovery reached as high as 93.3 %, and oil rejection attained 99.1 %. Meanwhile, the spiderweb-structured gel layer on the membrane surface displayed good mechanical stability. In summary, this novel membrane-modification method, inspired by the spider web structure, was simple, cost effective and environmentally friendly, thereby making it promising for future preparation of highly efficient oil-water emulsion separation membranes.


Assuntos
Carboximetilcelulose Sódica , Aranhas , Animais , Emulsões , Biomimética , Água/química
15.
Braz J Biol ; 84: e266319, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36197355

RESUMO

The aims of the present research was to find out the diversity of family Araneidae in district Swat Pakistan and to provide updated checklist of the family Araneidae from Pakistan. Also their occurrence throughout the year was given from District Swat Khyber Pakhtunkhwa, Pakistan. Data was collected from January 2018 to December-2018 from seven different Tehsils of District Swat by using different methods like pitfall trap, ground hand collection, air hand collection and were then preserved in plastic vials and appendorf tubes by using 70% ethanol. Camera mounted on microscope was used for photography. By using literature from World Spider Catalog, 2022, spiders were identified to species level. In a ttal of 1243 specimens of family Araneidae 4 genera and 7 species were identified. Dominant species with great number of specimen collected was Cyrtophora citricolla with 229 (18.4%) samples, followed by Bojaranius mitificus (15.7%), Neoscona Scylla (15.4%), Argiope lobata (14.8), Neoscona theisi (14.6%) and Neoscona polyspinippes (13.8%) respectively. While lowest collection was done of Argiope versicolor with 90 (7.3%) samples. High occurrence of spiders was studied during July 187 samples. Fluctuation in temperature can affect the diversity of spiders observed and recorded in present study with lowest collection done in low temperature. Moreover, the humidity also play a great role in spiders' population and occurrence.


Assuntos
Lista de Checagem , Aranhas , Animais , Etanol , Paquistão/epidemiologia , Plásticos
16.
J Proteome Res ; 21(11): 2783-2797, 2022 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-36260604

RESUMO

Acanthoscurria juruenicola is an Amazonian spider described for the first time almost a century ago. However, little is known about their venom composition. Here, we present a multiomics characterization of A. juruenicola venom by a combination of transcriptomics, proteomics, and peptidomics approaches. Transcriptomics of female venom glands resulted in 93,979 unique assembled mRNA transcript encoding proteins. A total of 92 proteins were identified in the venom by mass spectrometry, including 14 mature cysteine-rich peptides (CRPs). Quantitative analysis showed that CRPs, cysteine-rich secretory proteins, metalloproteases, carbonic anhydrases, and hyaluronidase comprise >90% of the venom proteome. Relative quantification of venom toxins was performed by DIA and DDA, revealing converging profiles of female and male specimens by both methods. Biochemical assays confirmed the presence of active hyaluronidases, phospholipases, and proteases in the venom. Moreover, the venom promoted in vivo paralytic activities in crickets, consistent with the high concentration of CRPs. Overall, we report a comprehensive analysis of the arsenal of toxins of A. juruenicola and highlight their potential biotechnological and pharmacological applications. Mass spectrometry data were deposited to the ProteomeXchange Consortium via the PRIDE repository with the dataset identifier PXD013149 and via the MassIVE repository with the dataset identifier MSV000087777.


Assuntos
Venenos de Aranha , Aranhas , Animais , Masculino , Feminino , Aranhas/genética , Aranhas/metabolismo , Venenos de Aranha/genética , Venenos de Aranha/química , Venenos de Aranha/metabolismo , Cisteína/metabolismo , Proteômica/métodos , Espectrometria de Massas/métodos , Proteoma/genética , Proteoma/metabolismo , Peptídeos/análise
17.
Insect Biochem Mol Biol ; 150: 103859, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36265807

RESUMO

Cuticular protein (CP) plays an essential role in the construction and function of exoskeleton in arthropods. CPR family, CP with Rebers and Riddiford (R&R) Consensus, is the largest CP family in insects, but it lacks systematic research in non-insect arthropods. In this study, we explored CPRs in the wolf spider, Pardosa pseudoannulata, a predator to many insect pests. We totally identified 152 CPRs in P. pseudoannulata genome, which were divided into two subgroups based on R&R Consensus sequences, with 12 CPRs in RR-1 and 140 in RR-2. All RR-2 members presented a novel Consensus with 34 amino acids, G-x(8)-G-x(6)-Y-x-A-x(3)-G-x(7)-N-E-x-G, which was a common characteristic for RR-2 CPRs in chelicerates. Transcriptome data was used to document the expression patterns of CPR genes in different tissues and ecdysis processes. The specific expressions were found for part CPR genes, such as five RR-2 genes that were specifically expressed in male genital bulbs and eleven RR-1 genes that were highly expressed in the integument. Due to the limited number and integument-specific expression of RR-1 genes, we further analyzed their responses to different environmental stresses at the transcriptional level. Except for PapsCPR11, ten RR-1 genes responded to at least one environmental stress, among with the expression of PapsCPR12 was significantly changed by three stresses (dryness, low temperature and imidacloprid treatments). Silencing PapsCPR12 increased the tolerance of P. pseudoannulata to imidacloprid. Overall, the results presented novel Consensus characteristics of CPRs in P. pseudoannulata, which was helpful for the identification and evolution analysis of CPRs in non-insect arthropods.


Assuntos
Artrópodes , Reanimação Cardiopulmonar , Aranhas , Masculino , Animais , Aranhas/genética , Aranhas/metabolismo , Neonicotinoides/metabolismo , Nitrocompostos/metabolismo , Artrópodes/metabolismo , Insetos
18.
Sci Rep ; 12(1): 17769, 2022 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-36273015

RESUMO

Net-casting spiders (Deinopidae) comprise a charismatic family with an enigmatic evolutionary history. There are 67 described species of deinopids, placed among three genera, Deinopis, Menneus, and Asianopis, that are distributed globally throughout the tropics and subtropics. Deinopis and Asianopis, the ogre-faced spiders, are best known for their giant light-capturing posterior median eyes (PME), whereas Menneus does not have enlarged PMEs. Molecular phylogenetic studies have revealed discordance between morphology and molecular data. We employed a character-rich ultra-conserved element (UCE) dataset and a taxon-rich cytochrome-oxidase I (COI) dataset to reconstruct a genus-level phylogeny of Deinopidae, aiming to investigate the group's historical biogeography, and examine PME size evolution. Although the phylogenetic results support the monophyly of Menneus and the single reduction of PME size in deinopids, these data also show that Deinopis is not monophyletic. Consequently, we formally transfer 24 Deinopis species to Asianopis; the transfers comprise all of the African, Australian, South Pacific, and a subset of Central American and Mexican species. Following the divergence of Eastern and Western deinopids in the Cretaceous, Deinopis/Asianopis dispersed from Africa, through Asia and into Australia with its biogeographic history reflecting separation of Western Gondwana as well as long-distance dispersal events.


Assuntos
Aranhas , Animais , Filogenia , Austrália , Citocromos , Oxirredutases , Evolução Molecular , Teorema de Bayes
19.
Acta Gastroenterol Belg ; 85(3): 542, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36198302

RESUMO

Question: We report the case of a 38y old woman who consulted for chronic diffuse abdominal pain related to previous irritable bowel syndrome diagnosis. Physical examination showed nonblanching reddish hyperpigmented reticular peri-umbilical skin patch (figure 1). What's your diagnosis? Answer: The diagnosis of erythema ab igne was made. Additional investigations confirmed repeated use of hot water bottles applied on abdominal wall for 3 weeks overnight for pain relief. Erythema ab igne is a pathognomonic cutaneous presentation of long-lasting exposure to heat sources (1). The pathophysiology of erythema ab igne remains uncertain. It has been suggested that heat exposure damages dermal vascular plexus and subsequent hemosiderin deposition leading to spider's web-like hyperpigmentation. Differential diagnosis of peri -umbilical dermatological manifestations includes digestive-related entities as caput medusae's sign (related to portal hypertension), Cullen's sign or Walzel's sign (related to acute pancreatitis); and non-digestive-related entities such as livedo reticularis (2). Erythema ab igne is well known from the dermatologists, mostly located on the lower limbs due to prolonged close exposition to heaters or on thighs due to laptop batteries (3). Erythema ab igne is usually of benign course, most often self-resolving after heat exposure discontinuation (3). We believe that it is of paramount to take into consideration the patients' pain and to propose an adapted management to avoid self-treatment.


Assuntos
Pancreatite , Aranhas , Doença Aguda , Animais , Eritema/diagnóstico , Eritema/etiologia , Hemossiderina , Humanos , Dor
20.
Commun Biol ; 5(1): 1156, 2022 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-36310293

RESUMO

Female web-building spiders disseminate pheromone from their webs that attracts mate-seeking males and deposit contact pheromone on their webs that induces courtship by males upon arrival. The source of contact and mate attractant pheromone components, and the potential ability of females to adjust their web's attractiveness, have remained elusive. Here, we report three new contact pheromone components produced by female false black widow spiders, Steatoda grossa: N-4-methylvaleroyl-O-butyroyl-L-serine, N-4-methylvaleroyl-O-isobutyroyl-L-serine and N-4-methylvaleroyl-O-hexanoyl-L-serine. The compounds originate from the posterior aggregate silk gland, induce courtship by males, and web pH-dependently hydrolyse at the carboxylic-ester bond, giving rise to three corresponding carboxylic acids that attract males. A carboxyl ester hydrolase (CEH) is present on webs and likely mediates the functional transition of contact sex pheromone components to the carboxylic acid mate attractant pheromone components. As CEH activity is pH-dependent, and female spiders can manipulate their silk's pH, they might also actively adjust their webs' attractiveness.


Assuntos
Atrativos Sexuais , Aranhas , Animais , Masculino , Feminino , Atrativos Sexuais/farmacologia , Serina , Seda/química , Ésteres
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