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1.
Syst Biol ; 2024 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-38733598

RESUMEN

Asymmetrical rates of cladogenesis and extinction abound in the Tree of Life, resulting in numerous minute clades that are dwarfed by larger sister groups. Such taxa are commonly regarded as phylogenetic relicts or "living fossils" when they exhibit an ancient first appearance in the fossil record and prolonged external morphological stasis, particularly in comparison to their more diversified sister groups. Due to their special status, various phylogenetic relicts tend to be well-studied and prioritized for conservation. A notable exception to this trend is found within Amblypygi ("whip spiders"), a visually striking order of functionally hexapodous arachnids that are notable for their antenniform first walking leg pair (the eponymous "whips"). Paleoamblypygi, the putative sister group to the remaining Amblypygi, is known from Late Carboniferous and Eocene deposits, but is survived by a single living species, Paracharon caecus Hansen, 1921, that was last collected in 1899. Due to the absence of genomic sequence-grade tissue for this vital taxon, there is no global molecular phylogeny for Amblypygi to date, nor a fossil-calibrated estimation of divergences within the group. Here, we report a previously unknown species of Paleoamblypygi from a cave site in Colombia. Capitalizing upon this discovery, we generated the first molecular phylogeny of Amblypygi, integrating ultraconserved element sequencing with legacy Sanger datasets and including described extant genera. To quantify the impact of sampling Paleoamblypygi on divergence time estimation, we performed in silico experiments with pruning of Paracharon. We demonstrate that the omission of relicts has a significant impact on the accuracy of node dating approaches that outweighs the impact of excluding ingroup fossils, which bears upon the ancestral range reconstruction for the group. Our results underscore the imperative for biodiversity discovery efforts in elucidating the phylogenetic relationships of "dark taxa", and especially phylogenetic relicts in tropical and subtropical habitats. The lack of reciprocal monophyly for Charontidae and Charinidae leads us to subsume them into one family, Charontidae, new synonymy.

2.
Artículo en Inglés | MEDLINE | ID: mdl-38494056

RESUMEN

BACKGROUND & AIMS: Abdominal pain is a major symptom of diseases that are associated with microbial dysbiosis, including irritable bowel syndrome and inflammatory bowel disease. Germ-free mice are more prone to abdominal pain than conventionally housed mice, and reconstitution of the microbiota in germ-free mice reduces abdominal pain sensitivity. However, the mechanisms underlying microbial modulation of pain remain elusive. We hypothesized that disruption of the intestinal microbiota modulates the excitability of peripheral nociceptive neurons. METHODS: In vivo and in vitro assays of visceral sensation were performed on mice treated with the nonabsorbable antibiotic vancomycin (50 µg/mL in drinking water) for 7 days and water-treated control mice. Bacterial dysbiosis was verified by 16s rRNA analysis of stool microbial composition. RESULTS: Treatment of mice with vancomycin led to an increased sensitivity to colonic distension in vivo and in vitro and hyperexcitability of dorsal root ganglion (DRG) neurons in vitro, compared with controls. Interestingly, hyperexcitability of DRG neurons was not restricted to those that innervated the gut, suggesting a widespread effect of gut dysbiosis on peripheral pain circuits. Consistent with this, mice treated with vancomycin were more sensitive than control mice to thermal stimuli applied to hind paws. Incubation of DRG neurons from naive mice in serum from vancomycin-treated mice increased DRG neuron excitability, suggesting that microbial dysbiosis alters circulating mediators that influence nociception. The cysteine protease inhibitor E64 (30 nmol/L) and the protease-activated receptor 2 (PAR-2) antagonist GB-83 (10 µmol/L) each blocked the increase in DRG neuron excitability in response to serum from vancomycin-treated mice, as did the knockout of PAR-2 in NaV1.8-expressing neurons. Stool supernatant, but not colonic supernatant, from mice treated with vancomycin increased DRG neuron excitability via cysteine protease activation of PAR-2. CONCLUSIONS: Together, these data suggest that gut microbial dysbiosis alters pain sensitivity and identify cysteine proteases as a potential mediator of this effect.

3.
Am J Physiol Gastrointest Liver Physiol ; 326(2): G176-G186, 2024 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-38084411

RESUMEN

Abdominal pain is a cardinal symptom of inflammatory bowel disease (IBD). Transient receptor potential (TRP) channels contribute to abdominal pain in preclinical models of IBD, and TRP melastatin 3 (TRPM3) has recently been implicated in inflammatory bladder and joint pain in rodents. We hypothesized that TRPM3 is involved in colonic sensation and is sensitized during colitis. We used immunohistochemistry, ratiometric Ca2+ imaging, and colonic afferent nerve recordings in mice to evaluate TRPM3 protein expression in colon-projecting dorsal root ganglion (DRG) neurons, as well as functional activity in DRG neurons and colonic afferent nerves. Colitis was induced using dextran sulfate sodium (DSS) in drinking water. TRPM3 protein expression was observed in 76% of colon-projecting DRG neurons and was often colocalized with calcitonin gene-related peptide. The magnitudes of intracellular Ca2+ transients in DRG neurons in response to the TRPM3 agonists CIM-0216 and pregnenolone sulfate sodium were significantly greater in neurons from mice with colitis compared with controls. In addition, the percentage of DRG neurons from mice with colitis that responded to CIM-0216 was significantly increased. CIM-0216 also increased the firing rate of colonic afferent nerves from control and mice with colitis. The TRPM3 inhibitor isosakuranetin inhibited the mechanosensitive response to distension of wide dynamic range afferent nerve units from mice with colitis but had no effect in control mice. Thus, TRPM3 contributes to colonic sensory transduction and may be a potential target for treating pain in IBD.NEW & NOTEWORTHY This is the first study to characterize TRPM3 protein expression and function in colon-projecting DRG neurons. A TRPM3 agonist excited DRG neurons and colonic afferent nerves from healthy mice. TRPM3 agonist responses in DRG neurons were elevated during colitis. Inhibiting TRPM3 reduced the firing of wide dynamic range afferent nerves from mice with colitis but had no effect in control mice.


Asunto(s)
Colitis , Enfermedades Inflamatorias del Intestino , Canales Catiónicos TRPM , Ratones , Animales , Colitis/metabolismo , Enfermedades Inflamatorias del Intestino/metabolismo , Neuronas/metabolismo , Ganglios Espinales , Colon/inervación , Dolor Abdominal , Canales Catiónicos TRPM/genética , Canales Catiónicos TRPM/metabolismo
4.
PLOS Glob Public Health ; 3(11): e0002307, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37992017

RESUMEN

INTRODUCTION: The population of Africa set to reach 2 billion by 2050. There is therefore great demand for housing across the continent. Research on modified novel designs for housing is a priority to ensure that these homes are not sites of infection for diseases transmission such as malaria. One trial to assess the protection afforded by novel design houses is underway in Mtwara Region, southeastern Tanzania. After constructing 110 of such homes across 60 villages, project staff encountered a certain reticence of the target population to occupy the homes and were faced with accusations of having nefarious intentions. This article explores these accusations, their impacts on home occupancy and lessons for future housing studies. METHODS: This qualitative study drew on in-depth interviews and focus group discussions with ten occupants of the intervention homes, six community leaders and a further 24 community members. Interviews were recorded, transcribed verbatim and translated to English for qualitative content analysis. RESULTS: In communities around the Star Homes, during construction and handover, project staff were widely associated with 'Freemasons', a term used to practices, secrecy, and other conspiracy theories in rural Tanzania. These connections were attributed to other community members and explained in terms of knowledge deficit or envy, with others hoping to be allocated the home. The stories were embedded in assumptions of reciprocity and suspicions about study motives, linked to limited experience of research. The relationship between the accusations of freemasonry and reticence to occupy the houses was not straightforward, with project staff or relatives playing a role in decisions. The stakes were high, because the recipients of Star Homes were the poorest families in targeted communities. CONCLUSION: The results indicate the need for long-term and proactive community engagement, which focuses on building relationships and providing information through recognizable voices and formats. Given the stakes at play in housing interventions, research teams should be prepared for the social upheaval the provision of free new housing can cause.

5.
Cladistics ; 39(6): 479-532, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37787157

RESUMEN

In the last decade and a half, advances in genetic sequencing technologies have revolutionized systematics, transforming the field from studying morphological characters or a few genetic markers, to genomic datasets in the phylogenomic era. A plethora of molecular phylogenetic studies on many taxonomic groups have come about, converging on, or refuting prevailing morphology or legacy-marker-based hypotheses about evolutionary affinities. Spider systematics has been no exception to this transformation and the inter-relationships of several groups have now been studied using genomic data. About 51 500 extant spider species have been described, all with a conservative body plan, but innumerable morphological and behavioural peculiarities. Inferring the spider tree of life using morphological data has been a challenging task. Molecular data have corroborated many hypotheses of higher-level relationships, but also resulted in new groups that refute previous hypotheses. In this review, we discuss recent advances in the reconstruction of the spider tree of life and highlight areas where additional effort is needed with potential solutions. We base this review on the most comprehensive spider phylogeny to date, representing 131 of the 132 spider families. To achieve this sampling, we combined six Sanger-based markers with newly generated and publicly available genome-scale datasets. We find that some inferred relationships between major lineages of spiders (such as Austrochiloidea, Palpimanoidea and Synspermiata) are robust across different classes of data. However, several new hypotheses have emerged with different classes of molecular data. We identify and discuss the robust and controversial hypotheses and compile this blueprint to design future studies targeting systematic revisions of these problematic groups. We offer an evolutionary framework to explore comparative questions such as evolution of venoms, silk, webs, morphological traits and reproductive strategies.


Asunto(s)
Arañas , Humanos , Animales , Arañas/genética , Filogenia , Genómica , Análisis de Secuencia de ADN , Genoma
6.
Syst Biol ; 72(6): 1233-1246, 2023 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-37527553

RESUMEN

Burmese amber is a significant source of fossils that documents the mid-Cretaceous biota. This deposit was formed around 99 Ma on the Burma Terrane, which broke away from Gondwana and later collided with Asia, although the timing is disputed. Palpimanoidea is a dispersal-limited group that was a dominant element of the Mesozoic spider fauna, and has an extensive fossil record, particularly from Burmese amber. Using morphological and molecular data, evolutionary relationships of living and fossil Palpimanoidea are examined. Divergence dating with fossils as terminal tips shows timing of diversification is contemporaneous with continental breakup.Ancestral range estimations show widespread ancestral ranges that divide into lineages that inherit different Pangean fragments, consistent with vicariance. Our results suggest that the Burmese amber fauna has ties to Gondwana due to a historical connection in the Early Cretaceous, and that the Burma Terrane facilitated biotic exchange by transporting lineages from Gondwana into the Holarctic in the Cretaceous.


Asunto(s)
Ámbar , Arañas , Animales , Filogenia , Mianmar , Evolución Biológica , Fósiles , Arañas/genética
7.
Phys Chem Chem Phys ; 25(32): 21416-21427, 2023 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-37534596

RESUMEN

Heterogenisation of homogeneous catalysts onto solid supports represents a potential strategy to make the homogeneous catalytic function recyclable and reuseable. Yet, it is usually the case that immobilised catalysts have much lower catalytic activity than their homogeneous counterpart. In addition, the presence of a solid interface introduces a higher degree of complexity by modulating solid/fluid interactions, which can often influence adsorption properties of solvents and reactive species and, ultimately, catalytic activity. In this work, the influence of support and solvent in the H-transfer reduction of propionaldehyde over Al(OiPr)3-SiO2, Al(OiPr)3-TiO2 and Al(OiPr)3-Al2O3 heterogenised catalysts has been studied. Reaction studies are coupled with both NMR relaxation measurements as well as molecular dynamics (MD) simulations in order to unravel surface and solvation effects during the reaction. The results show that, whilst the choice of the support does not influence significantly catalytic activity, reactions carried out in solvents with high affinity for the catalyst surface, or able to hinder access to active sites due to solvation effects, have a lower activity. MD calculations provide key insights into bulk solvation effects involved in such reactions, which are thought to play an important role in determining the catalytic behaviour. The activity of the heterogenised catalysts was found to be comparable with that of the homogeneous Al(OiPr)3 catalysts for all supports used, showing that for the type of reaction studied immobilisation of the homogeneous catalyst onto solid supports is a viable, robust and effective strategy.

8.
Mol Phylogenet Evol ; 186: 107855, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37311493

RESUMEN

The miniature orb weaving spiders (symphytognathoids) are a group of small spiders (<2 mm), including the smallest adult spider Patu digua (0.37 mm in body length), that have been classified into five families. The species of one of its constituent lineages, the family Anapidae, build a remarkable diversity of webs (ranging from orbs to sheet webs and irregular tangles) and even include a webless kleptoparasitic species. Anapids are also exceptional because of the extraordinary diversity of their respiratory systems. The phylogenetic relationships of symphytognathoid families have been recalcitrant with different classes of data, such as, monophyletic with morphology and its concatenation with Sanger-based six markers, paraphyletic (including a paraphyletic Anapidae) with solely Sanger-based six markers, and polyphyletic with transcriptomes. In this study, we capitalized on a large taxonomic sampling of symphytognathoids, focusing on Anapidae, and using de novo sequenced ultraconserved elements (UCEs) combined with UCEs recovered from available transcriptomes and genomes. We evaluated the conflicting relationships using a variety of support metrics and topology tests. We found support for the phylogenetic hypothesis proposed using morphology to obtain the "symphytognathoids'' clade, Anterior Tracheal System (ANTS) Clade and monophyly of the family Anapidae. Anapidae can be divided into three major lineages, the Vichitra Clade (including Teutoniella, Holarchaea, Sofanapis and Acrobleps), the subfamily Micropholcommatinae and the Orb-weaving anapids (Owa) Clade. Biogeographic analyses reconstructed a hypothesis of multiple long-distance transoceanic dispersal events, potentially influenced by the Antarctic Circumpolar Current and West Wind Drift. In symphytognathoids, the ancestral anterior tracheal system transformed to book lungs four times and reduced book lungs five times. The posterior tracheal system was lost six times. The orb web structure was lost four times independently and transformed into sheet web once.


Asunto(s)
Arañas , Animales , Filogenia , Genoma , Transcriptoma , Sistema Respiratorio
9.
Trans R Soc Trop Med Hyg ; 117(10): 678-681, 2023 10 03.
Artículo en Inglés | MEDLINE | ID: mdl-37350735

RESUMEN

Millions of affordable healthy homes are needed for the rapidly expanding population of sub-Saharan Africa. This enormous challenge is an opportunity to address pervasive health issues linked to housing, where diseases that most impact children-malaria, diarrhoea and respiratory tract infections-are often acquired. A pilot project in northern Tanzania demonstrated the potential of novel house designs to reduce infectious disease transmission in homes. To conduct a randomized controlled trial of one novel-design house, the research team moved to the southeast of the country. This article describes the challenges experienced during the construction and initial evaluation of the novel house.


Asunto(s)
Malaria , Infecciones del Sistema Respiratorio , Niño , Humanos , Tanzanía/epidemiología , Vivienda , Proyectos Piloto , Malaria/epidemiología , Malaria/prevención & control
10.
Contemp Fam Ther ; : 1-11, 2023 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-37361259

RESUMEN

Racial trauma has long been an issue in American society. Recent incidents of racial violence, including the attack and murder of George Floyd and the rise of anti-Asian hate have garnered significant media attention. People often use social media to express their emotions and perspectives on national events, and it has become a popular forum for posting and commenting on content related to timely social issues. In effort to understand individual perspectives, and experiences of racial trauma discussed on social media, we analyzed content labeled with the hashtag "racial trauma" on TikTok during significant racial incidents from March 2020 to May 2022. Results of content analysis showed six themes, (1) encountering racism, (2) traumatic experiences, (3) consequences of experiencing racial trauma, (4) expressing difficult feelings, (5) questioning and challenging oppression, denial, and privilege, and (6) a call to action: raising awareness. Findings inform clinicians' understanding of how their clients experience racial trauma. Clinical implications for incorporating a nuanced understanding of racial trauma in mental health treatment are discussed.

11.
J Neonatal Nurs ; 2023 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-36811089

RESUMEN

We are reporting our engagement with the 'Learning from Excellence' initiative in the neonatal intensive care unit during the covid era, with enhanced professional and personal stresses in the workforce. It highlights the positive experiences around technical management of sick neonates and human factors, like team working, leadership and communication.

12.
Int Clin Psychopharmacol ; 38(1): 45-56, 2023 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-35916575

RESUMEN

A systematic review was undertaken to identify randomized controlled trials (RCTs) comparing the efficacy and safety of lurasidone, brexpiprazole and cariprazine (selected because of a shared safety profile) with each other or placebo in adult patients with schizophrenia. Key outcomes included: Positive and Negative Syndrome Scales (PANSS), Clinical Global Impression-Severity (CGI-S) scores and cardiovascular and metabolic parameters. A feasibility assessment evaluated the trials' suitability for inclusion in a Bayesian network meta-analysis (NMA). Random effects models were used. In total, 1138 records were identified and 19 RCTs contributed to the NMA. Lurasidone doses of 160 mg performed best in terms of change in PANSS and CGI-S scores at 6 weeks, with stronger evidence when compared with brexpiprazole than cariprazine. The safety outcomes were variable; for all treatments, the 95% credible intervals usually contained 'no difference'. Active treatments were associated with lower odds of discontinuation due to any cause, and higher odds of experiencing any adverse event. Lurasidone was comparable to brexpiprazole and cariprazine for efficacy and safety outcomes assessed at 6 weeks, with the 160 mg dose being superior for the change in PANSS and CGI-S outcomes. The lurasidone results were relatively consistent across doses compared with brexpiprazole and cariprazine.


Asunto(s)
Clorhidrato de Lurasidona , Humanos , Clorhidrato de Lurasidona/efectos adversos , Metaanálisis en Red
13.
Research (Wash D C) ; 2022: 9865108, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36061818

RESUMEN

A new chiral aggregate-based tool for asymmetric synthesis has been developed by taking advantage of chiral aggregates of GAP (Group-Assisted Purification) reagents, N-phosphonyl imines. This tool was proven to be successful in the asymmetric GAP synthesis of functionalized 2,3-dihydrobenzofurans by reacting salicyl N-phosphonyl imines with dialkyl bromomalonates in various cosolvent systems. The chiral induction can be controlled by differentiating between two asymmetric directions simply by changing the ratios of cosolvents which are commonly adopted in AIE (aggregation-induced emission) systems. The formation of chiral aggregates was witnessed by a new analytical tool-aggregation-induced polarization (AIP). The present synthetic method will be broadly extended for general organic synthesis, particularly, for asymmetric synthesis and asymmetric catalysis in the future.

14.
Sci Rep ; 12(1): 3896, 2022 03 10.
Artículo en Inglés | MEDLINE | ID: mdl-35273227

RESUMEN

The arachnid order Schizomida is a relatively understudied group of soil-dwelling predators found on all continents except Antarctica. While efforts to understand their biology are growing, there is still much to know about them. A curious aspect of their morphology is the male flagellum, a sexually dimorphic, tail-like structure which differs in shape across the order and functions in their courtship rituals. The flagellar shape is important for taxonomic classification, yet few efforts have been made to examine shape diversity across the group. Using elliptical Fourier analysis, a type of geometric morphometrics based on shape outline, we quantified shape differences across a combined nearly 550 outlines in the dorsal and lateral views, categorizing them based on genus, family, biogeographic realm, and habitat, with special emphasis on Caribbean and Cuban fauna. We tested for allometric relationships, differences in disparity based on locations and sizes in morphospace among these categories, and for clusters of shapes in morphospace. We found multiple differences in all categories despite apparent overlaps in morphospace, evolutionary allometry, and evidence for discrete clusters in some flagellum shapes. This study can serve as a foundation for further study on the evolution, diversification, and taxonomic utility of the male flagellum.


Asunto(s)
Ecosistema , Suelo , Evolución Biológica , Flagelos , Análisis de Fourier , Humanos , Masculino , Filogenia
15.
Int J Dermatol ; 61(6): 746-754, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34423443

RESUMEN

Atopic dermatitis (AD) is a chronic heterogeneous condition characterized by erythematous, pruritic, and inflamed skin. Janus kinase (JAK) inhibitors are a new class of drugs that target proteins in the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway. These drugs can be administered orally or topically to inhibit signaling of the JAK-STAT pathway and minimize the production of proinflammatory cytokines. The efficacy and safety of JAK inhibitors have been investigated in phase 2 and 3 clinical trials for AD. The safety of new medications, which are immunosuppressive by nature, is of utmost concern for the prescriber and patient alike. Herein we summarize the safety results of clinical trials using oral abrocitinib, upadacitinib, and baricitinib, as well as topical ruxolitinib and delgocitinib for the treatment of AD. The most prevalent (2-5% occurrence rate) treatment-emergent adverse events from oral JAK inhibitor use in AD were nausea, upper respiratory tract infection, headache, herpes zoster, herpes simplex, acne, increased blood creatine phosphokinase levels, and decreased platelet counts. Topical JAK inhibitors were not associated with systemic effects. All studies reported that JAK inhibitors were well tolerated in patients with AD in comparison with the control group. While the use of JAK inhibitors in patients suffering from AD is very promising, trials reported to date are of short duration (maximum 16 weeks), and more information on the long-term safety of these novel agents is required.


Asunto(s)
Dermatitis Atópica , Inhibidores de las Cinasas Janus , Dermatitis Atópica/tratamiento farmacológico , Humanos , Inhibidores de las Cinasas Janus/efectos adversos , Quinasas Janus , Factores de Transcripción STAT , Transducción de Señal
16.
Nanoscale ; 14(2): 320-324, 2022 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-34932055

RESUMEN

Printed electronics based on liquid-exfoliated nanosheet networks are limited by inter-nanosheet junctions and thick films which hinder field-effect gating. Here, few-layer molybdenum disulfide nanosheets are assembled by Langmuir deposition into thin films, and size selection is shown to lead to a thousandfold conductivity enhancement with potential applicability to all nanosheet networks.

17.
Zookeys ; 1071: 49-61, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34887693

RESUMEN

The first fossil Archaeidae in Cambay amber from India, of Eocene age, is documented. The inclusion is a spider exuvium and is placed as Myrmecarchaea based on the presence of elongated legs, a slightly elongated pedicel with lateral spurs, and a diastema between coxae III and IV that is similar to M.antecessor from Oise amber. The previous occurrences of the genus are from Baltic and Oise amber, both of Eocene age. Because most spiders, including Archaeidae, only molt as juveniles, the exuvium does not have adult features nor have distinct species-specific features, and a new taxon is not erected. This new record further extends the distribution of the family and genus to India 50-52 million years ago. Myrmecarchaea in Indian Cambay amber provides additional evidence that India in the Early Eocene had affinities with the Palearctic mainland rather than showing Gondwanan insularity.

18.
Integr Org Biol ; 3(1): obab027, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34661063

RESUMEN

To capture prey otherwise unattainable by muscle function alone, some animal lineages have evolved movements that are driven by stored elastic energy, producing movements of remarkable speed and force. One such example that has evolved multiple times is a trap-jaw mechanism, in which the mouthparts of an animal are loaded with energy as they open to a wide gape and then, when triggered to close, produce a terrific force. Within the spiders (Araneae), this type of attack has thus far solely been documented in the palpimanoid family Mecysmaucheniidae but a similar morphology has also been observed in the distantly related araneoid subfamily Pararchaeinae, leading to speculation of a trap-jaw attack in that lineage as well. Here, using high-speed videography, we test whether cheliceral strike power output suggests elastic-driven movements in the pararchaeine Pararchaea alba. The strike speed attained places P. alba as a moderately fast striker exceeding the slowest mecysmaucheniids, but failing to the reach the most extreme high-speed strikers that have elastic-driven mechanisms. Using microcomputed tomography, we compare the morphology of P. alba chelicerae in the resting and open positions, and their related musculature, and based on results propose a mechanism for cheliceral strike function that includes a torque reversal latching mechanism. Similar to the distantly related trap-jaw mecysmaucheniid spiders, the unusual prosoma morphology in P. alba seemingly allows for highly maneuverable chelicerae with a much wider gape than typical spiders, suggesting that increasingly maneuverable joints coupled with a latching mechanism may serve as a precursor to elastic-driven movements.

19.
Pharmaceutics ; 13(8)2021 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-34452257

RESUMEN

Members of the Bacillus genus, particularly the "Bacillus subtilis group", are known to produce amphipathic lipopeptides with biosurfactant activity. This includes the surfactins, fengycins and iturins that have been associated with antibacterial, antifungal, and anti-viral properties. We have screened a large collection of Bacillus, isolated from human, animal, estuarine water and soil samples and found that the most potent lipopeptide producers are members of the species Bacillus velezensis. B. velezensis lipopeptides exhibited anti-bacterial activity which was localised on the surface of both vegetative cells and spores. Interestingly, lipopeptide micelles (6-10 nm diameter) were detectable in strains exhibiting the highest levels of activity. Micelles were stable (heat and gastric stable) and shown to entrap other antimicrobials produced by the host bacterium (exampled here was the dipeptide antibiotic chlorotetaine). Commercially acquired lipopeptides did not exhibit similar levels of inhibitory activity and we suspect that micelle formation may relate to the particular isomeric forms produced by individual bacteria. Using naturally produced micelle formulations we demonstrated that they could entrap antimicrobial compounds (e.g., clindamycin, vancomycin and resveratrol). Micellar incorporation of antibiotics increased activity. Bacillus is a prolific producer of antimicrobials, and this phenomenon could be exploited naturally to augment antimicrobial activity. From an applied perspective, the ability to readily produce Bacillus micelles and formulate with drugs enables a possible strategy for enhanced drug delivery.

20.
Sci Rep ; 11(1): 16299, 2021 08 11.
Artículo en Inglés | MEDLINE | ID: mdl-34381067

RESUMEN

Correct orchestration of nervous system development is a profound challenge that involves coordination of complex molecular and cellular processes. Mechanistic target of rapamycin (mTOR) signaling is a key regulator of nervous system development and synaptic function. The mTOR kinase is a hub for sensing inputs including growth factor signaling, nutrients and energy levels. Activation of mTOR signaling causes diseases with severe neurological manifestations, such as tuberous sclerosis complex and focal cortical dysplasia. However, the molecular mechanisms by which mTOR signaling regulates nervous system development and function are poorly understood. Unkempt is a conserved zinc finger/RING domain protein that regulates neurogenesis downstream of mTOR signaling in Drosophila. Unkempt also directly interacts with the mTOR complex I component Raptor. Here we describe the generation and characterisation of mice with a conditional knockout of Unkempt (UnkcKO) in the nervous system. Loss of Unkempt reduces Raptor protein levels in the embryonic nervous system but does not affect downstream mTORC1 targets. We also show that nervous system development occurs normally in UnkcKO mice. However, we find that Unkempt is expressed in the adult cerebellum and hippocampus and behavioural analyses show that UnkcKO mice have improved memory formation and cognitive flexibility to re-learn. Further understanding of the role of Unkempt in the nervous system will provide novel mechanistic insight into the role of mTOR signaling in learning and memory.


Asunto(s)
Cognición/fisiología , Proteínas de Unión al ADN/metabolismo , Malformaciones del Desarrollo Cortical/metabolismo , Dedos de Zinc/fisiología , Animales , Cerebelo/metabolismo , Drosophila/metabolismo , Células HeLa , Hipocampo/metabolismo , Humanos , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Neurogénesis/fisiología , Transducción de Señal/fisiología
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