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1.
Nature ; 589(7843): 567-571, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33505035

RESUMO

Overfishing is the primary cause of marine defaunation, yet declines in and increasing extinction risks of individual species are difficult to measure, particularly for the largest predators found in the high seas1-3. Here we calculate two well-established indicators to track progress towards Aichi Biodiversity Targets and Sustainable Development Goals4,5: the Living Planet Index (a measure of changes in abundance aggregated from 57 abundance time-series datasets for 18 oceanic shark and ray species) and the Red List Index (a measure of change in extinction risk calculated for all 31 oceanic species of sharks and rays). We find that, since 1970, the global abundance of oceanic sharks and rays has declined by 71% owing to an 18-fold increase in relative fishing pressure. This depletion has increased the global extinction risk to the point at which three-quarters of the species comprising this functionally important assemblage are threatened with extinction. Strict prohibitions and precautionary science-based catch limits are urgently needed to avert population collapse6,7, avoid the disruption of ecological functions and promote species recovery8,9.


Assuntos
Organismos Aquáticos/isolamento & purificação , Biodiversidade , Conservação dos Recursos Naturais , Espécies em Perigo de Extinção/estatística & dados numéricos , Oceanos e Mares , Tubarões , Rajidae , Animais , Conservação dos Recursos Naturais/legislação & jurisprudência , Conservação dos Recursos Naturais/métodos , Extinção Biológica , Feminino , Peixes , Cadeia Alimentar , Objetivos , História do Século XX , História do Século XXI , Dinâmica Populacional/estatística & dados numéricos , Comportamento Predatório , Medição de Risco , Desenvolvimento Sustentável
2.
Annu Rev Microbiol ; 75: 49-69, 2021 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-34038159

RESUMO

The human gut microbiota is a complex community of prokaryotic and eukaryotic microbes and viral particles that is increasingly associated with many aspects of host physiology and health. However, the classical microbiology approach of axenic culture cannot provide a complete picture of the complex interactions between microbes and their hosts in vivo. As such, recently there has been much interest in the culture of gut microbial ecosystems in the laboratory as a strategy to better understand their compositions and functions. In this review, we discuss the model platforms and methods available in the contemporary microbiology laboratory to study human gut microbiomes, as well as current knowledge surrounding the isolation of human gut microbes for the potential construction of defined communities for use in model systems.


Assuntos
Microbioma Gastrointestinal , Microbiota , Humanos
3.
Proc Natl Acad Sci U S A ; 120(5): e2216891120, 2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36689654

RESUMO

Overfishing is the most significant threat facing sharks and rays. Given the growth in consumption of seafood, combined with the compounding effects of habitat loss, climate change, and pollution, there is a need to identify recovery paths, particularly in poorly managed and poorly monitored fisheries. Here, we document conservation through fisheries management success for 11 coastal sharks in US waters by comparing population trends through a Bayesian state-space model before and after the implementation of the 1993 Fisheries Management Plan for Sharks. We took advantage of the spatial and temporal gradients in fishing exposure and fisheries management in the Western Atlantic to analyze the effect on the Red List status of all 26 wide-ranging coastal sharks and rays. We show that extinction risk was greater where fishing pressure was higher, but this was offset by the strength of management engagement (indicated by strength of National and Regional Plan of Action for sharks and rays). The regional Red List Index (which tracks changes in extinction risk through time) declined in all regions until the 1980s but then improved in the North and Central Atlantic such that the average extinction risk is currently half that in the Southwest. Many sharks and rays are wide ranging, and successful fisheries management in one country can be undone by poorly regulated or unregulated fishing elsewhere. Our study underscores that well-enforced, science-based management of carefully monitored fisheries can achieve conservation success, even for slow-growing species.


Assuntos
Tubarões , Animais , Conservação dos Recursos Naturais , Teorema de Bayes , Pesqueiros , Ecossistema
4.
J Cell Sci ; 136(16)2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37505110

RESUMO

Multiciliated cells contain hundreds of cilia whose directional movement powers the mucociliary clearance of the airways, a vital host defense mechanism. Multiciliated cell specification requires canonical Wnt signaling, which then must be turned off. Next, ciliogenesis and polarized ciliary orientation are regulated by noncanonical Wnt/planar cell polarity (Wnt/PCP) signaling. The mechanistic relationship between the Wnt pathways is unknown. We show that DKK3, a secreted canonical Wnt regulator and WNT4, a noncanonical Wnt ligand act together to facilitate a canonical to noncanonical Wnt signaling switch during multiciliated cell formation. In primary human airway epithelial cells, DKK3 and WNT4 CRISPR knockout blocks, whereas ectopic expression promotes, multiciliated cell formation by inhibiting canonical Wnt signaling. Wnt4 and Dkk3 single-knockout mice also display defective ciliated cells. DKK3 and WNT4 are co-secreted from basal stem cells and act directly on multiciliated cells via KREMEN1 and FZD6, respectively. We provide a novel mechanism that links specification to cilium biogenesis and polarization for proper multiciliated cell formation.


Assuntos
Células Epiteliais , Via de Sinalização Wnt , Animais , Humanos , Camundongos , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Cílios/metabolismo , Células Epiteliais/metabolismo , Camundongos Knockout , Proteína Wnt4/metabolismo
5.
J Biol Chem ; 299(12): 105360, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37863263

RESUMO

Protein arginine N-methyltransferases are a family of epigenetic enzymes responsible for monomethylation or dimethylation of arginine residues on histones. Dysregulation of protein arginine N-methyltransferase activity can lead to aberrant gene expression and cancer. Recent studies have shown that PRMT2 expression and histone H3 methylation at arginine 8 are correlated with disease severity in glioblastoma multiforme, hepatocellular carcinoma, and renal cell carcinoma. In this study, we explore a noncatalytic mechanistic role for PRMT2 in histone methylation by investigating interactions between PRMT2, histone peptides and proteins, and other PRMTs using analytical and enzymatic approaches. We quantify interactions between PRMT2, peptide ligands, and PRMT1 in a cofactor- and domain-dependent manner using differential scanning fluorimetry. We found that PRMT2 modulates the substrate specificity of PRMT1. Using calf thymus histones as substrates, we saw that a 10-fold excess of PRMT2 promotes PRMT1 methylation of both histone H4 and histone H2A. We found equimolar or a 10-fold excess of PRMT2 to PRMT1 can improve the catalytic efficiency of PRMT1 towards individual histone substrates H2A, H3, and H4. We further evaluated the effects of PRMT2 towards PRMT1 on unmodified histone octamers and mononucleosomes and found marginal PRMT1 activity improvements in histone octamers but significantly greater methylation of mononucleosomes in the presence of 10-fold excess of PRMT2. This work reveals the ability of PRMT2 to serve a noncatalytic role through its SH3 domain in driving site-specific histone methylation marks.


Assuntos
Histonas , Proteína-Arginina N-Metiltransferases , Arginina/metabolismo , Histonas/metabolismo , Metilação , Proteína-Arginina N-Metiltransferases/metabolismo , Fluorometria , Especificidade por Substrato , Estabilidade Proteica , Ligação Proteica , Domínios Proteicos , Ligantes , Humanos
6.
Chembiochem ; 25(6): e202300773, 2024 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-38266114

RESUMO

Target engagement assays typically detect and quantify the direct physical interaction of a protein of interest and its ligand through stability changes upon ligand binding. Commonly used target engagement methods detect ligand-induced stability by subjecting samples to thermal or proteolytic stress. Here we describe a new variation to these approaches called Isothermal Ligand-induced Resolubilization Assay (ILIRA), which utilizes lyotropic solubility stress to measure ligand binding through changes in target protein solubility. We identified distinct buffer systems and salt concentrations that compromised protein solubility for four diverse proteins: dihydrofolate reductase (DHFR), nucleoside diphosphate-linked moiety X motif 5 (NUDT5), poly [ADP-ribose] polymerase 1 (PARP1), and protein arginine N-methyltransferase 1 (PRMT1). Ligand-induced solubility rescue was demonstrated for these proteins, suggesting that ILIRA can be used as an additional target engagement technique. Differences in ligand-induced protein solubility were assessed by Coomassie blue staining for SDS-PAGE and dot blot, as well as by NanoOrange, Thioflavin T, and Proteostat fluorescence, thus offering flexibility for readout and assay throughput.


Assuntos
Ligação Proteica , Ligantes , Proteólise
7.
Can J Anaesth ; 71(5): 570-578, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38438681

RESUMO

PURPOSE: To determine the 90% effective dose (ED90) of intrathecal hyperbaric bupivacaine for Cesarean delivery under combined spinal-epidural anesthesia (CSE) in parturients with super obesity (body mass index [BMI] ≥ 50 kg·m-2). METHODS: We enrolled parturients with BMI ≥ 50 kg·m-2 with term, singleton vertex pregnancies undergoing elective Cesarean delivery under CSE. An independent statistician generated the 0.75% hyperbaric bupivacaine dosing regimen in increments of 0.75 mg using a biased-coin up-down sequential allocation technique. This was combined with 15 µg fentanyl, 150 µg morphine, and normal saline to a volume of 2.05 mL. The initial and maximum doses were 9.75 mg and 12 mg, respectively. Participants, clinical team, and outcome assessors were blinded to the dose. The primary outcome was block success, defined as T6 block to pinprick within ten minutes and no intraoperative analgesic supplementation within 90 min of spinal injection. We determined the ED90 using logistic regression. RESULTS: We enrolled 45 parturients and included 42 in the analysis. All doses achieved a T6 level within ten minutes, and the primary outcome occurred in 0/1 (0%) of the 9.75-mg doses, 2/3 (67%) of the 10.5-mg doses, 21/27 (78%) of the 11.25-mg doses, and 11/11 (100%) of the 12-mg doses. The ED90 of hyperbaric bupivacaine was 11.56 mg (95% confidence interval, 11.16 to 11.99). Four parturients (9.5%) had sensory level higher than T2, but none was symptomatic or required general anesthesia. CONCLUSION: The estimated ED90 of hyperbaric bupivacaine with fentanyl and morphine in parturients with super obesity undergoing Cesarean delivery under CSE was approximately 11.5 mg. STUDY REGISTRATION: ClinicalTrials.gov (NCT03781388); first submitted 18 December 2018.


RéSUMé: OBJECTIF: Notre objectif était de déterminer la dose efficace à 90 % (DE90) de bupivacaïne hyperbare intrathécale pour l'accouchement par césarienne sous péri-rachianesthésie combinée (PRC) chez les personnes parturientes atteintes de super obésité (indice de masse corporelle [IMC] ≥ 50 kg·m−2). MéTHODE: Nous avons recruté des personnes parturientes ayant un IMC ≥ 50 kg·m−2 présentant des grossesses uniques à terme, en présentation céphalique et bénéficiant d'un accouchement par césarienne programmée sous PRC. Un·e statisticien·ne indépendant·e a généré le schéma posologique de bupivacaïne hyperbare à 0,75 % par incréments de 0,75 mg à l'aide d'une technique d'allocation séquentielle en escalier. La bupivacaïne a été combinée à 15 µg de fentanyl, 150 µg de morphine et à une solution physiologique salée jusqu'à un volume de 2,05 mL. Les doses initiale et maximale étaient respectivement de 9,75 mg et 12 mg. Les participant·es, l'équipe clinique et les personnes évaluant les résultats n'avaient pas connaissance de la dose. Le critère d'évaluation principal était la réussite du bloc, définie comme un bloc à T6 à la piqûre dans les dix minutes et aucune supplémentation analgésique peropératoire dans les 90 minutes suivant l'injection rachidienne. Nous avons déterminé la DE90 à l'aide d'une méthode de régression logistique. RéSULTATS: Nous avons recruté 45 personnes parturientes et en avons inclus 42 dans l'analyse. Toutes les doses ont atteint le niveau T6 en dix minutes, et le critère d'évaluation principal a été obtenu pour 0/1 (0 %) des doses de 9,75 mg, 2/3 (67 %) des doses de 10,5 mg, 21/27 (78 %) des doses de 11,25 mg et 11/11 (100 %) des doses de 12 mg. La DE90 de bupivacaïne hyperbare était de 11,56 mg (intervalle de confiance à 95 %, 11,16 à 11,99). Quatre personnes parturientes (9,5 %) ont affiché un niveau sensoriel supérieur à T2, mais aucune n'était symptomatique ni n'a nécessité d'anesthésie générale. CONCLUSION: La DE90 estimée de bupivacaïne hyperbare avec fentanyl et morphine chez les personnes parturientes hyperobèses bénéficiant d'une césarienne sous PRC était d'environ 11,5 mg. ENREGISTREMENT DE L'éTUDE: ClinicalTrials.gov (NCT03781388); soumis pour la première fois le 18 décembre 2018.


Assuntos
Anestesia Epidural , Anestesia Obstétrica , Raquianestesia , Feminino , Humanos , Gravidez , Anestesia Obstétrica/métodos , Anestésicos Locais , Bupivacaína , Método Duplo-Cego , Fentanila , Morfina , Obesidade
8.
J Cardiothorac Vasc Anesth ; 38(2): 505-516, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37880038

RESUMO

Neuraxial anesthesia (NA) has been contraindicated in patients with aortic stenosis (AS) due to concerns of sympathetic blockade and hemodynamic instability. These considerations are based on precautionary expert recommendations, supported by expected physiologic effects, but in the absence of any published scientific evidence. In light of the increasing elderly population and the prevalence of AS, this systematic review compiles available literature on NA in patients with AS to address the understanding of the anesthetic practice and safety in this population. Using a systematic approach, PubMed, Embase, and Web of Science were searched for studies of patients with AS who exclusively received NA. Primary outcomes included intraoperative and postoperative complications. Of 1,433 citations, 61 met full-text inclusion criteria, including 3,228 patients undergoing noncardiac (n = 3,146, 97.5%), obstetric (n = 69, 2.1%), and cardiac (n = 13, 0.4%) procedures. Significant data heterogeneity (local anesthetic dosing, intraoperative interventions, and measured outcomes) prevented formal metanalysis, but descriptive data are presented. Spinal block (n = 2,856, 88.5%) and epidural anesthesia (n = 397, 12.3%) were administered most frequently. Hypotension requiring vasopressors was the most common intraoperative complication-noncardiac (n = 16, 9.9%), obstetric (n = 6, 13.0%), and cardiac (n = 1, 7.7%)-with resolution in all patients and no reported intraoperative cardiovascular collapse or mortality. The relative risk of different AS severities remains unclear, and optimal medication dosing remains elusive. The authors' data suggested that NA may not be contraindicated in carefully selected patients with AS. The authors' results should inform the design of future prospective studies comparing NA and general anesthesia in patients with AS.


Assuntos
Anestesia Epidural , Raquianestesia , Anestésicos , Estenose da Valva Aórtica , Gravidez , Feminino , Humanos , Idoso , Estudos Prospectivos , Anestesia Epidural/métodos , Complicações Pós-Operatórias/prevenção & controle , Anestesia Geral , Estenose da Valva Aórtica/cirurgia
9.
J Adolesc ; 96(3): 539-550, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37811912

RESUMO

INTRODUCTION: Adolescents report using digital technologies for emotion regulation (digital ER), with the aim of feeling better (i.e., improving emotions and reducing loneliness). In this 7-day diary study, we investigated associations of digital ER, emotions, and loneliness, and tested whether prior emotional problems moderated these associations. METHOD: Participants were 312 Australian adolescents (Mage = 13.91, SD = 1.52; 44% boys). Daily surveys measured digital ER; end-of-day happiness, sadness, worry, anger, and loneliness; and peak sadness, worry, and anger. End-of day emotions were subtracted from peak emotions to calculate emotion recovery for sadness, worry, and anger. Participants were randomly selected from two symptom strata (high/low) defined by depression and social anxiety measures collected before the diary. Data were analyzed using multilevel path modeling. Cross-level interactions tested whether symptom strata moderated associations. RESULTS: Digital ER was associated with more recovery from peak to end-of-day sadness and worry, but also with increased sadness, worry, anger, and loneliness by the next end-of-day. Higher end-of-day loneliness was associated with increased next-day digital ER. Prior emotional symptoms were not a significant moderator of daily digital ER and emotion associations. CONCLUSION: Adolescents who report more digital ER in a day show more recovery from the peak of negative emotion that day, but this recovery dissipates, with digital ER also associated with increased negative emotion and loneliness by the next day for all adolescents, regardless of prior symptom status. Lonelier adolescents use more digital ER by the next day, suggesting they need support to make social connections-online or offline.


Assuntos
Regulação Emocional , Solidão , Masculino , Adolescente , Humanos , Feminino , Tecnologia Digital , Austrália , Emoções , Ira
10.
J Am Chem Soc ; 145(6): 3306-3311, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36728842

RESUMO

Arynes offer immense potential for diversification of benzenoid rings, which occur in pharmaceuticals, agrochemicals, and liquid crystals. However, accessing these high-energy intermediates requires synthetic precursors, which involve either harsh conditions or multistep syntheses. The development of alternative methods to access arynes using simpler substrates and milder conditions is necessary for a more streamlined approach. Here, we describe a two-step formal dehydrogenation of simple arenes to generate arynes at a remote position relative to traditionally reactive groups, e.g., halides. This approach is enabled by regioselective installation and ejection of an "onium" leaving group, and we demonstrate the compatibility of simple arenes (20 examples) and arynophiles (8 examples). Moreover, through direct comparison, we show that our formal dehydrogenation method is both more functional group tolerant and efficient in generating arynes than the current state-of-the-art aryne precursors. Finally, we show that aryne intermediates offer opportunities for regioselective C-H amination that are distinct from other methods.

11.
Am J Physiol Lung Cell Mol Physiol ; 324(6): L771-L782, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-37039381

RESUMO

Multiciliated cell loss is a hallmark of airway epithelial remodeling in chronic inflammatory airway diseases including cystic fibrosis (CF), asthma, and chronic obstructive pulmonary disease. It disrupts mucociliary clearance, which fuels disease progression. Effective clearance requires an optimal proportion of multiciliated and secretory cells. This is controlled by Notch signaling such that between two adjacent cells the one that activates Notch becomes a secretory cell and the one that avoids Notch activation becomes a multiciliated cell. Consequently, blocking Notch by a small molecule inhibitor of the γ-secretase enzyme that cleaves the Notch receptor for signal activation directs differentiation toward the multiciliated lineage. Thus, γ-secretase inhibitor (GSI) treatment may alleviate multiciliated cell loss in lung disease. Here, we demonstrate the therapeutic restoration of multiciliated cells by the GSI LY450139 (semagacestat). LY450139 increased multiciliated cell numbers in a dose-dependent manner in healthy primary human nasal epithelial cells (HNECs) during differentiation and in mature cultures, but not when applied during early epithelialization of progenitors. LY450139 did not impact stem cell proliferation. Basal and apical administration were equally effective. In healthy adult mice, LY450139 increased multiciliated cell numbers without detectible toxicity. LY450139 also increased multiciliated cells and decreased excess mucus secretory cells in CF HNECs and IL-13 remodeled healthy HNECs. LY450139 normalized multiciliated cell numbers in CF HNECs without interfering with the activity of CFTR modulator compounds. In summary, we demonstrate that GSI administration is a promising therapeutic to restore multiciliated cells and potentially improve epithelial function in a wide range of chronic lung diseases.NEW & NOTEWORTHY Our findings show that low-dose, short-term topical or systemic γ-secretase inhibitor treatment may lead to restoration of multiciliated cells without toxicity and potentially improve epithelial function in a wide range of chronic lung diseases.


Assuntos
Asma , Fibrose Cística , Humanos , Camundongos , Animais , Secretases da Proteína Precursora do Amiloide/metabolismo , Epitélio/metabolismo , Células Epiteliais/metabolismo , Transdução de Sinais/fisiologia , Receptores Notch
12.
Nat Mater ; 21(2): 143-159, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34385685

RESUMO

Organotypic models of patient-specific tumours are revolutionizing our understanding of cancer heterogeneity and its implications for personalized medicine. These advancements are, in part, attributed to the ability of organoid models to stably preserve genetic, proteomic, morphological and pharmacotypic features of the parent tumour in vitro, while also offering unprecedented genomic and environmental manipulation. Despite recent innovations in organoid protocols, current techniques for cancer organoid culture are inherently uncontrolled and irreproducible, owing to several non-standardized facets including cancer tissue sources and subsequent processing, medium formulations, and animal-derived three-dimensional matrices. Given the potential for cancer organoids to accurately recapitulate the intra- and intertumoral biological heterogeneity associated with patient-specific cancers, eliminating the undesirable technical variability accompanying cancer organoid culture is necessary to establish reproducible platforms that accelerate translatable insights into patient care. Here we describe the current challenges and recent multidisciplinary advancements and opportunities for standardizing next-generation cancer organoid systems.


Assuntos
Neoplasias , Organoides , Animais , Humanos , Neoplasias/patologia , Neoplasias/terapia , Organoides/patologia , Medicina de Precisão/métodos , Proteômica
13.
Biomacromolecules ; 24(12): 5926-5939, 2023 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-37988588

RESUMO

Hydrogels with encapsulated cells have widespread biomedical applications, both as tissue-mimetic 3D cultures in vitro and as tissue-engineered therapies in vivo. Within these hydrogels, the presentation of cell-instructive extracellular matrix (ECM)-derived ligands and matrix stiffness are critical factors known to influence numerous cell behaviors. While individual ECM biopolymers can be blended together to alter the presentation of cell-instructive ligands, this typically results in hydrogels with a range of mechanical properties. Synthetic systems that allow for the facile incorporation and modulation of multiple ligands without modification of matrix mechanics are highly desirable. In the present work, we leverage protein engineering to design a family of xeno-free hydrogels (i.e., devoid of animal-derived components) consisting of recombinant hyaluronan and recombinant elastin-like proteins (ELPs), cross-linked together with dynamic covalent bonds. The ELP components incorporate cell-instructive peptide ligands derived from ECM proteins, including fibronectin (RGD), laminin (IKVAV and YIGSR), collagen (DGEA), and tenascin-C (PLAEIDGIELTY and VFDNFVL). By carefully designing the protein primary sequence, we form 3D hydrogels with defined and tunable concentrations of cell-instructive ligands that have similar matrix mechanics. Utilizing this system, we demonstrate that neurite outgrowth from encapsulated embryonic dorsal root ganglion (DRG) cultures is significantly modified by cell-instructive ligand content. Thus, this library of protein-engineered hydrogels is a cell-compatible system to systematically study cell responses to matrix-derived ligands.


Assuntos
Elastina , Peptídeos , Animais , Ligantes , Peptídeos/química , Elastina/química , Matriz Extracelular/química , Técnicas de Cultura de Células/métodos , Hidrogéis/química
14.
Br J Clin Pharmacol ; 89(3): 1027-1035, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36164710

RESUMO

AIM: Metformin is used for the management of type 2 diabetes mellitus (T2DM) and is being tested clinically as an anticancer agent. Metformin concentrations safely achievable in human solid tissues including tumours are unknown. This study was designed to determine metformin concentration in tissue compartments as a function of dose to inform rational dosing in preclinical models and interpretation of clinical results." METHODS: Subjects with solid tumours to be treated by resection and either (A) willingness to take metformin for 7-10 days before surgery or (B) taking metformin for T2DM were eligible. Whole blood, plasma, tumour, tumour-adjacent uninvolved tissue and subcutaneous adipose tissue were obtained for liquid chromatography with tandem mass spectrometry to measure metformin concentrations. RESULTS: All subjects had primary lung tumours. Metformin dose was significantly correlated with drug concentrations in all tissues analysed. Intersubject metformin concentrations varied by over two orders of magnitude. Metformin concentrations were significantly higher in tumour tissues and lower in adipose tissues compared to other tissues. Concentrations in blood and plasma were significantly correlated with concentrations in solid tissues. CONCLUSION: Metformin accumulates in cellular compartments. Concentrations observed in plasma, blood, lung and tumour tissues in subjects treated with US Food and Drug Administration-approved doses for T2DM are lower than those typically used in tissue culture studies. However, such tissue concentrations are in line with those found within cultured cells treated with supra-pharmacological doses of metformin. Given the large intersubject variability in metformin concentrations, it is imperative to determine whether there is an association between tissue metformin concentration and anticancer activity in humans.


Assuntos
Diabetes Mellitus Tipo 2 , Neoplasias Pulmonares , Metformina , Humanos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Tecido Adiposo , Neoplasias Pulmonares/tratamento farmacológico , Plasma , Hipoglicemiantes
15.
Gen Comp Endocrinol ; 339: 114295, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-37121405

RESUMO

Emerging fungal pathogens are a direct threat to vertebrate biodiversity. Elucidating the mechanisms by which mycoses impact host fitness is an important step towards effective prediction and management of disease outcomes in populations. The vertebrate acute stress response is an adaptive mechanism that allows individuals to meet challenges to homeostasis and survival in dynamic environments. Disease may cause stress, and coping with fungal infections may require shifts in resource allocation that alter the ability of hosts to mount an acute response to other external stressors. We examined the glucocorticoid and glycemic response to acute capture stress in a population of free-living pygmy rattlesnakes, Sistrurus miliarius, afflicted with an emerging mycosis (ophidiomycosis) across seasons. In all combinations of disease status and season, acute capture stress resulted in a significant glucocorticoid and glycemic response. While disease was not associated with elevated baseline or stress-induced corticosterone (CORT), disease was associated with an increased glucocorticoid stress response (post-stress minus baseline) across seasons. Both baseline and stress-induced glucose were lower in snakes with ophidiomycosis compared to uninfected snakes. The relationship between glucose and pre- and post-stress CORT depended on infection status, and positive correlations were only observed in uninfected snakes. The variables which explained CORT and glucose levels were different. The pattern of CORT was highly seasonal (winter high - summer low) and negatively related to body condition. Glucose, on the other hand, did not vary seasonally or with body condition and was strongly related to sex (male high - female low). Our results highlight the fact that circulating CORT and glucose are sensitive to different intrinsic and extrinsic predictor variables and support the hypothesis that disease alters the acute physiological stress response. Whether the effects of ophidiomycosis on the acute stress response result in sublethal effects on fitness should be investigated in future studies.


Assuntos
Corticosterona , Glucocorticoides , Humanos , Animais , Masculino , Feminino , Serpentes , Estresse Fisiológico
16.
Ann Plast Surg ; 90(5S Suppl 3): S236-S241, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-36752509

RESUMO

BACKGROUND: Historically, breast-conserving surgery may not be pursued when the oncologic deformity is too significant and/or not tolerant of radiotherapy. Reconstruction using recruitment of upper abdominal wall tissue based on the intercostal artery perforating vessels can expand breast conservation therapy indications for cases that would otherwise require mastectomy. This report aims to describe the expanded use of the intercostal artery perforator (ICAP) as well as detail its ease of adoption. METHODS: All patients who underwent ICAP flaps for reconstruction of partial mastectomy defects at a single institution were included. Demographic data, intraoperative data, and postoperative outcomes were recorded. Intercostal artery perforator flap outcomes are compared with standard alloplastic reconstruction after mastectomy. RESULTS: Twenty-seven patients received ICAP flaps compared with 27 unilateral tissue expanders (TE). Six cases included nipple-areolar reconstruction, and 6 included skin resurfacing. The average defect size was 217.7 (30.3-557.9) cm 3 . Plastic-specific operative time was significantly longer in the ICAP cohort ( P < 0.01) with no difference in total operative time ( P > 0.05). Length of stay was significantly longer, and major postoperative complications were significantly more common in TE patients ( P < 0.01, P > 0.05). Seven TE patients required outpatient opiate refills (26%) versus 1 ICAP patient (4%) ( P = 0.02). One ICAP patient required additional surgery. Patients reported satisfaction with aesthetic outcomes. Average follow-up in the ICAP cohort was 7 months. CONCLUSIONS: Lumpectomy reconstruction using ICAP flaps can effectively expand breast conservation therapy indications in resection of breast skin, nipple-areola, or large volume defects. This technique is adoptable and of limited complexity. Enhancing breast-conserving surgery may improve outcomes compared with mastectomy reconstruction. Intercostal artery perforator patients may require fewer opioids, shorter hospital stays, and lower operative burden.


Assuntos
Neoplasias da Mama , Mamoplastia , Retalho Perfurante , Humanos , Feminino , Mastectomia Segmentar/métodos , Retalho Perfurante/irrigação sanguínea , Mastectomia/métodos , Neoplasias da Mama/cirurgia , Mamoplastia/métodos , Artérias
17.
J Craniofac Surg ; 34(7): e682-e684, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37639663

RESUMO

Syndrome of the Trephined (SoT) is a frequently misunderstood and underdiagnosed outcome of decompressive craniectomy, especially in cases of trauma. The pressure gradient between atmospheric pressure and the sub-atmospheric intracranial pressure results in a sinking of the scalp overlying the craniectomy site. This gradually compresses the underlying brain parenchyma. This parenchymal compression can disrupt normal autoregulation and subsequent metabolism, yielding symptoms ranging from headaches, dizziness, altered behavior to changes in sensation, and difficulty with ambulation, coordination, and activities of daily living. We present a case of SoT treated with a 3D-printed custom polycarbonate external cranial orthotic that allowed us to re-establish this pressure gradient by returning the cranium to a closed system. The patient demonstrated subjective improvement in quality of life and his symptoms. This was consistent with the re-expanded brain parenchyma on CT imaging.


Assuntos
Craniectomia Descompressiva , Trepanação , Humanos , Atividades Cotidianas , Qualidade de Vida , Crânio/diagnóstico por imagem , Crânio/cirurgia , Impressão Tridimensional
18.
J Youth Adolesc ; 52(12): 2464-2479, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37733121

RESUMO

Adolescents face many academic pressures that require good coping skills, but coping skills can also depend on social resources, such as parental support and fewer negative interactions. The aim of this study was to determine if parental support and parental negative interactions concurrently and longitudinally relate to adolescents' ways of academic coping, above and beyond the impact of three types of academic stress, students' achievement at school (i.e., grades in school), and age. Survey data were collected from 839 Australian students in grades 5 to 10 (Mage = 12.2, SD = 1.72; 50% girls). Students completed measures of support and negative interactions with parents; academic stress from workload, external pressure (teachers/parents) to achieve, and intrapsychic pressure for high achievement; and ways of academic coping that were grouped into two positive and two negative types. Hypothesized associations were tested concurrently and from one year to the next using path modeling. Beyond the numerous significant influences of academic stress and achievement on coping, and control for age and COVID-19 timing, adolescents with more parental support reported more use of engagement coping (e.g., strategizing) and comfort-seeking, whereas those who reported more negative interactions with parents reported more use of disengagement coping (e.g., concealment) and escape. In the longitudinal model, parental support predicted an increase in engagement and comfort-seeking and a decrease in disengagement coping, whereas negative interaction with parents predicted an increase in disengagement coping. Overall, the findings support the view that coping with academic stressors will continue to depend on parent-adolescent relationships even into the teen years.


Assuntos
COVID-19 , Feminino , Adolescente , Humanos , Criança , Masculino , Estudos Longitudinais , Austrália , Adaptação Psicológica , Pais
19.
Geophys Res Lett ; 49(6): e2021GL097450, 2022 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-35864927

RESUMO

Deciphering paleoclimate on Mars has been a driving goal of Martian science for decades. Most research has addressed this issue by studying Mars' large polar layered deposits (PLDs) as a paleoclimate proxy, but the certainty to which we know the link between climate and orbit is debated. Here, we instead consider the record of other, smaller ice deposits located within craters separated from the PLDs using images from NASA's High Resolution Imaging Science Experiment camera and signal processing techniques. We show that the climate record in Burroughs Crater (72.3°S, 116.6°E) contains robust evidence of orbital forcing, with periodicities that have wavelengths of 15.6 and 6.5 m. The ratio of these dominant wavelengths is 2.4, the same as the ratio between the periods of Mars' obliquity changes and orbital precession. This result suggests orbital control of recent Mars climate, and would imply an average ice accumulation rate of 0.13 mm/yr over 4.5 Myr in this region.

20.
Anesth Analg ; 134(4): 834-842, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35139044

RESUMO

BACKGROUND: Chloroprocaine is a short-acting local anesthetic that has been used for spinal anesthesia in outpatient surgery. There is limited experience with spinal chloroprocaine for prophylactic cervical cerclage placement. We sought to determine the effective dose of intrathecal chloroprocaine for 90% of patients (ED90) undergoing prophylactic cervical cerclage placement. We hypothesized that the ED90 of intrathecal chloroprocaine when combined with 10-ug fentanyl would be between 33 and 54 mg. METHODS: In this prospective 2-center double-blinded study, we enrolled women undergoing prophylactic cervical cerclage placement under combined spinal-epidural anesthesia. A predetermined dose of intrathecal 3% chloroprocaine with fentanyl 10 ug was administered. The initial dose was 45-mg intrathecal chloroprocaine. Subsequent dose adjustments were determined based on the response of the previous subject using an up-down sequential allocation with a biased-coin design. A dose was considered effective if at least a T12 block was achieved, and there was no requirement for epidural activation or intraoperative analgesic supplementation during the procedure. The primary outcome was the ED90 of intrathecal chloroprocaine with fentanyl 10 ug. Secondary outcomes included duration of surgery, anesthetic side effects, time to resolution of motor and sensory block, time to achieve recovery room discharge criteria, and patient satisfaction with anesthetic care. Isotonic regression was used to estimate the ED90. RESULTS: Forty-seven patients were enrolled into the study. Two patients were excluded (1 protocol violation and 1 failed block). In total, 45 patients completed the study. The estimated ED90 (95% confidence interval) for intrathecal chloroprocaine combined with fentanyl 10 ug was 49.5 mg (45.0-50.1 mg). The median (interquartile range [IQR]) duration of surgery was 15 (10-24) minutes. Resolution of the motor (Bromage 0) and sensory block took a median time of 60 (45-90) minutes and 90 (75-105) minutes, respectively. The median time to achieve recovery room discharge criteria was 150 (139-186) minutes. Satisfaction with anesthetic management was high in all patients. There were no reports of postdural puncture headache or transient neurological symptoms postoperatively. CONCLUSIONS: The ED90 of intrathecal chloroprocaine combined with fentanyl 10 ug was 49.5 mg. Intrathecal chloroprocaine was associated with rapid block recovery and high patient satisfaction, which makes it well suited for outpatient obstetric procedures.


Assuntos
Raquianestesia , Cerclagem Cervical , Raquianestesia/efeitos adversos , Raquianestesia/métodos , Anestésicos Locais/efeitos adversos , Bupivacaína , Método Duplo-Cego , Feminino , Fentanila/efeitos adversos , Humanos , Gravidez , Procaína/efeitos adversos , Procaína/análogos & derivados , Estudos Prospectivos
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