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1.
Front Pediatr ; 12: 1388921, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38725987

RESUMO

Objectives: To develop a predictive model for patent ductus arteriosus (PDA) in preterm infants at seven days postpartum. The model employs ultrasound measurements of the ductus arteriosus (DA) intimal thickness (IT) obtained within 24 h after birth. Methods: One hundred and five preterm infants with gestational ages ranging from 27.0 to 36.7 weeks admitted within 24 h following birth were prospectively enrolled. Echocardiographic assessments were performed to measure DA IT within 24 h after birth, and DA status was evaluated through echocardiography on the seventh day postpartum. Potential predictors were considered, including traditional clinical risk factors, M-mode ultrasound parameters, lumen diameter of the DA (LD), and DA flow metrics. A final prediction model was formulated through bidirectional stepwise regression analysis and subsequently subjected to internal validation. The model's discriminative ability, calibration, and clinical applicability were also assessed. Results: The final predictive model included birth weight, application of mechanical ventilation, left ventricular end-diastolic diameter (LVEDd), LD, and the logarithm of IT (logIT). The receiver operating characteristic (ROC) curve for the model, predicated on logIT, exhibited excellent discriminative power with an area under the curve (AUC) of 0.985 (95% CI: 0.966-1.000), sensitivity of 1.000, and specificity of 0.909. Moreover, the model demonstrated robust calibration and goodness-of-fit (χ2 value = 0.560, p > 0.05), as well as strong reproducibility (accuracy: 0.935, Kappa: 0.773), as evidenced by 10-fold cross-validation. A decision curve analysis confirmed the model's broad clinical utility. Conclusions: Our study successfully establishes a predictive model for PDA in preterm infants at seven days postpartum, leveraging the measurement of DA IT. This model enables identifying, within the first 24 h of life, infants who are likely to benefit from timely DA closure, thereby informing treatment decisions.

2.
Chempluschem ; : e202400158, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38733075

RESUMO

Photocatalytic technology can efficiently convert solar energy to chemical energy and this process is considered as one of the green and sustainable technology for practical implementation. In recent years, metal-organic frameworks (MOFs) have attracted widespread attention due to their unique advantages and have been widely applied in the field of photocatalysis. Among them, noble metals have contributed significant advances to the field as effective catalysts in photocatalytic reactions. Importantly, noble metals can also form a synergistic catalytic effect with MOFs to further improve the efficiency of photocatalytic reactions. However, how to precisely control the synergistic effect between MOFs and noble metals to improve the photocatalytic performance of materials still needs to be further studied. In this review, the synergistic effects of MOFs and noble metal catalysts in photocatalytic reactions are firstly summarized in terms of noble metal nanoparticles, noble metal monoatoms, noble metal compounds, and noble metal complexes, and focus on the mechanisms and advantages of these synergistic effects, so as to provide useful guidance for the further research and application of MOFs and contribute to the development of the field of photocatalysis.

3.
Research (Wash D C) ; 7: 0335, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38766644

RESUMO

Cuproptosis-based cancer nanomedicine has received widespread attention recently. However, cuproptosis nanomedicine against pancreatic ductal adenocarcinoma (PDAC) is severely limited by cancer stem cells (CSCs), which reside in the hypoxic stroma and adopt glycolysis metabolism accordingly to resist cuproptosis-induced mitochondria damage. Here, we leverage hyperbaric oxygen (HBO) to regulate CSC metabolism by overcoming tumor hypoxia and to augment CSC elimination efficacy of polydopamine and hydroxyethyl starch stabilized copper-diethyldithiocarbamate nanoparticles (CuET@PH NPs). Mechanistically, while HBO and CuET@PH NPs inhibit glycolysis and oxidative phosphorylation, respectively, the combination of HBO and CuET@PH NPs potently suppresses energy metabolism of CSCs, thereby achieving robust tumor inhibition of PDAC and elongating mice survival importantly. This study reveals novel insights into the effects of cuproptosis nanomedicine on PDAC CSC metabolism and suggests that the combination of HBO with cuproptosis nanomedicine holds significant clinical translation potential for PDAC patients.

4.
Sci Rep ; 14(1): 11588, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38773207

RESUMO

Current assessment methods for diabetic foot ulcers (DFUs) lack objectivity and consistency, posing a significant risk to diabetes patients, including the potential for amputations, highlighting the urgent need for improved diagnostic tools and care standards in the field. To address this issue, the objective of this study was to develop and evaluate the Smart Diabetic Foot Ulcer Scoring System, ScoreDFUNet, which incorporates artificial intelligence (AI) and image analysis techniques, aiming to enhance the precision and consistency of diabetic foot ulcer assessment. ScoreDFUNet demonstrates precise categorization of DFU images into "ulcer," "infection," "normal," and "gangrene" areas, achieving a noteworthy accuracy rate of 95.34% on the test set, with elevated levels of precision, recall, and F1 scores. Comparative evaluations with dermatologists affirm that our algorithm consistently surpasses the performance of junior and mid-level dermatologists, closely matching the assessments of senior dermatologists, and rigorous analyses including Bland-Altman plots and significance testing validate the robustness and reliability of our algorithm. This innovative AI system presents a valuable tool for healthcare professionals and can significantly improve the care standards in the field of diabetic foot ulcer assessment.


Assuntos
Algoritmos , Inteligência Artificial , Pé Diabético , Pé Diabético/diagnóstico , Pé Diabético/patologia , Humanos , Reprodutibilidade dos Testes , Processamento de Imagem Assistida por Computador/métodos , Índice de Gravidade de Doença
5.
J Chem Inf Model ; 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38709146

RESUMO

Developing new pharmaceuticals is a costly and time-consuming endeavor fraught with significant safety risks. A critical aspect of drug research and disease therapy is discerning the existence of interactions between drugs and proteins. The evolution of deep learning (DL) in computer science has been remarkably aided in this regard in recent years. Yet, two challenges remain: (i) balancing the extraction of profound, local cohesive characteristics while warding off gradient disappearance and (ii) globally representing and understanding the interactions between the drug and target local attributes, which is vital for delivering molecular level insights indispensable to drug development. In response to these challenges, we propose a DL network structure, MolLoG, primarily comprising two modules: local feature encoders (LFE) and global interactive learning (GIL). Within the LFE module, graph convolution networks and leap blocks capture the local features of drug and protein molecules, respectively. The GIL module enables the efficient amalgamation of feature information, facilitating the global learning of feature structural semantics and procuring multihead attention weights for abstract features stemming from two modalities, providing biologically pertinent explanations for black-box results. Finally, predictive outcomes are achieved by decoding the unified representation via a multilayer perceptron. Our experimental analysis reveals that MolLoG outperforms several cutting-edge baselines across four data sets, delivering superior overall performance and providing satisfactory results when elucidating various facets of drug-target interaction predictions.

6.
J Chemother ; : 1-8, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38591989

RESUMO

The objective of this study was to evaluate the efficacy of various dosing regimens of omadacycline against main drug-resistant pathogens in the treatment of acute bacterial skin and skin structure infections (ABSSSI) and community-acquired bacterial pneumonia (CABP). Monte Carlo simulations were conducted using pharmacokinetic parameters and pharmacodynamic data to calculate cumulative fractions of response (CFRs) in terms of drug area under the concentration curve/minimum inhibition concentration targets.CFR ≥ 90% was considered optimal for a dosage regimen. CFR of any approved oral/intravenous regimen with loading-dose was ≥ 90% against methicillin-resistant Staphylococcus aureus (MRSA) for ABSSSI and penicillin-resistant Streptococcus pneumonia, tetracycline-resistant Streptococcus pneumonia, MRSA and ß-lactamase positive Haemophilus influenzae for CABP. In conclusion, approved oral/intravenous loading and maintenance doses of omadacycline showed enough efficacy in the treatment of ABSSI and CABP caused by the main drug-resistant pathogens.

7.
Ying Yong Sheng Tai Xue Bao ; 35(3): 648-658, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38646752

RESUMO

Carbon wet deposition and river carbon output in river basins are important components of global carbon cycle. The assessment of both properties is of great significance for regional carbon budget. However, research on these topics in high-latitude permafrost regions in China is still lacking. We conducted dynamic monitoring of carbon wet deposition and carbon output in the river from May 28th to October 30th, 2022, in Laoyeling watershed, a typical forested watershed in the Da Xing'an Mountains permafrost region. We analyzed the variations of carbon component concentrations and fluxes in precipitation and river water, and estimated the contribution of carbon wet deposition to carbon output in the watershed. The results showed that wet deposition fluxes of dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), and total dissolved carbon (TDC) in the Laoyeling watershed were 1354.86, 684.59, and 2039.45 kg·km-2, respectively. The fluxes of DOC, DIC, TDC, particulate organic carbon (POC), particulate inorganic carbon (PIC), and total carbon (TC) in the river were 601.75, 1977.30, 2579.05, 125.13, 21.99, and 2726.17 kg·km-2, respectively. The contribution of TDC wet deposition to the river TDC output was 9941.89 kg, accounting for 17.6% of total output. The DIC concentration in the river showed significant seasonal differences, with increased runoff resulting from precipitation leading to a decrease in DIC concentration in the river and showing a clear dilution effect, while the concentrations of DOC, POC, and PIC increased, mainly due to erosion effect. In conclusion, carbon wet deposition flux in the Laoyeling watershed was mainly determined by precipitation, and its contribution to river carbon output was relatively small compared to other factor. Runoff was the dominant factor affecting river carbon output. The results would provide important insights into carbon cycling and carbon budget balance in permafrost regions under climate change.


Assuntos
Carbono , Monitoramento Ambiental , Florestas , Pergelissolo , Rios , China , Rios/química , Carbono/análise , Ciclo do Carbono , Chuva/química , Ecossistema
8.
J Hazard Mater ; 470: 134204, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38579586

RESUMO

Selenium (Se) plays a critical role in diverse biological processes and is widely used across manufacturing industries. However, the contamination of Se oxyanions also poses a major public health concern. Microbial transformation is a promising approach to detoxify Se oxyanions and produce elemental selenium nanoparticles (SeNPs) with versatile industrial potential. Yeast-like fungi are an important group of environmental microorganisms, but their mechanisms for Se oxyanions reduction remain unknown. In this study, we found that Aureobasidium melanogenum I15 can reduce 1.0 mM selenite by over 90% within 48 h and efficiently form intracellular or extracellular spherical SeNPs. Metabolomic and proteomic analyses disclosed that A. melanogenum I15 evolves a complicated selenite reduction mechanism involving multiple metabolic pathways, including the glutathione/glutathione reductase pathway, the thioredoxin/thioredoxin reductase pathway, the siderophore-mediated pathway, and multiple oxidoreductase-mediated pathways. This study provides the first report on the mechanism of selenite reduction and SeNPs biogenesis in yeast-like fungi and paves an alternative avenue for the bioremediation of selenite contamination and the production of functional organic selenium compounds.


Assuntos
Ascomicetos , Ácido Selenioso , Selênio , Ácido Selenioso/metabolismo , Selênio/metabolismo , Ascomicetos/metabolismo , Oxirredução , Nanopartículas/química , Nanopartículas/metabolismo , Nanopartículas Metálicas/química , Biodegradação Ambiental , Proteínas Fúngicas/metabolismo , Proteômica
9.
Cell Death Discov ; 10(1): 190, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38653740

RESUMO

Pancreatic cancer is one of the most fatal cancers in the world. A growing number of studies have begun to demonstrate that mitochondria play a key role in tumorigenesis. Our previous study reveals that NDUFS2 (NADH: ubiquinone oxidoreductase core subunit S2), a core subunit of the mitochondrial respiratory chain complex I, is upregulated in Pancreatic adenocarcinoma (PAAD). However, its role in the development of PAAD remains unknown. Here, we showed that NDUFS2 played a critical role in the survival, proliferation and migration of pancreatic cancer cells by inhibiting mitochondrial cell death. Additionally, protein mass spectrometry indicated that the NDUFS2 was interacted with a deubiquitinase, OTUB1. Overexpression of OTUB1 increased NDUFS2 expression at the protein level, while knockdown of OTUB1 restored the effects in vitro. Accordingly, overexpression and knockdown of OTUB1 phenocopied those of NDUFS2 in pancreatic cancer cells, respectively. Mechanically, NDUFS2 was deubiquitinated by OTUB1 via K48-linked polyubiquitin chains, resulted in an elevated protein stability of NDUFS2. Moreover, the growth of OTUB1-overexpressed pancreatic cancer xenograft tumor was promoted in vivo, while the OTUB1-silenced pancreatic cancer xenograft tumor was inhibited in vivo. In conclusion, we revealed that OTUB1 increased the stability of NDUFS2 in PAAD by deubiquitylation and this axis plays a pivotal role in pancreatic cancer tumorigenesis and development.

10.
Angew Chem Int Ed Engl ; : e202405255, 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38682659

RESUMO

Precise regulation of the active site structure is an important means to enhance the activity and selectivity of catalysts in CO2 electroreduction. Here, we creatively introduce anionic groups, which can not only stabilize metal sites with strong coordination ability but also have rich interactions with protons at active sites to modify the electronic structure and proton transfer process of catalysts. This strategy helps to convert CO2 into fuel chemicals at low overpotentials. As a typical example, a composite catalyst, CuO/Cu-NSO4/CN, with highly dispersed Cu(II)-SO4 sites has been reported, in which CO2 electroreduction to formate occurs at a low overpotential with a high Faradaic efficiency (-0.5 V vs. RHE, FEHCOO-=87.4%). Pure HCOOH is produced with an energy conversion efficiency of 44.3% at a cell voltage of 2.8 V. Theoretical modeling demonstrates that sulfate promotes CO2 transformation into a carboxyl intermediate followed by HCOOH generation, whose mechanism is significantly different from that of the traditional process via a formate intermediate for HCOOH production.

11.
BMC Nurs ; 23(1): 227, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38566058

RESUMO

BACKGROUND: Some studies suggest that female patients have more concerns about receiving intimate care from male than female nurses. Thus, providing intimate care to female patients is a challenging experience for male nurses. The purpose of this study was to explore Chinese male nurses' experiences and process of providing intimate clinical care to female patients. METHODS: A constructivist grounded theory approach was used to develop a theoretical understanding of male nurses' experiences. This study included participants from 3 hospitals in different locations in China. Twenty-five male nurses were recruited using purposive and theoretical sampling. Semi-structured interviews were conducted. Data analysis was completed using initial coding, focused coding, theoretical coding and memo writing to produce core concepts and categories, and theory development. RESULTS: Chinese male nurses' experiences of providing intimate care to female patients can be constructed as a three-stage process: (1) anticipation of the level of embarrassment, (2) deciding on the process: do it or not do it and (3) protecting both parties and dealing with embarrassment. Additionally, seven themes and associated categories were identified to represent the important factors in the process of male nurses providing intimate care to female patients in China. CONCLUSIONS: Chinese traditional culture may affect the embarrassment in Chinese male nurses providing intimate care to female patients. The embarrassing situation can be divided into three different stages, and male nurses have different main concerns in each stage. Hospital nursing administrators should consider the experiences and needs of male nurses in providing intimate care and provide them with psychological support, education and training.

12.
J Food Sci ; 89(4): 2277-2291, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38488738

RESUMO

Calcium peptide chelates are developed as efficient supplements for preventing calcium deficiency. Spent hen meat (SHM) contains a high percentage of proteins but is generally wasted due to the disadvantages such as hard texture. We chose the underutilized SHM to produce peptides to bind calcium by proteolysis and aimed to investigate chelation between calcium and peptides in hydrolysate for a sustainable purpose. The optimized proteolysis conditions calculated from the result of response surface methodology for two-step hydrolysis were 0.30% (wenzyme/wmeat) for papain with a hydrolysis time of 3.5 h and 0.18% (wenzyme/wmeat) for flavourzyme with a hydrolysis time of 2.8 h. The enzymatic hydrolysate (EH) showed a binding capacity of 63.8 ± 1.8 mg calcium/g protein. Ethanol separation for EH improved the capacity up to a higher value of 68.6 ± 0.6 mg calcium/g protein with a high association constant of 420 M-1 (25°C) indicating high stability. The separated fraction with a higher amount of Glu, Asp, Lys, and Arg had higher calcium-binding capacity, which was related to the number of ─COOH and ─NH2 groups in peptide side chains according to the result from amino acid analysis and Fourier transform infrared spectroscopy. Two-step enzymatic hydrolysis and ethanol separation were an efficient combination to produce peptide mixtures derived from SHM with high calcium-binding capacity. The high percentage of hydrophilic amino acids in the separated fraction was concluded to increase calcium-binding capacity. This work provides foundations for increasing spent hen utilization and developing calcium peptide chelates based on underutilized meat.


Assuntos
Cálcio , Galinhas , Animais , Feminino , Cálcio/metabolismo , Galinhas/metabolismo , Hidrolisados de Proteína/química , Peptídeos/química , Hidrólise , Papaína/química , Aminoácidos , Cálcio da Dieta/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Carne , Etanol
13.
J Hazard Mater ; 469: 134096, 2024 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-38522195

RESUMO

Arsenic (As)-contaminated soil poses great health risk to human mostly through inadvertent oral exposure. We investigated CaAl-layered double hydroxide (CaAl-LDH), a promising immobilising agent, for the remediation of As-contaminated Chinese soils. The effects on specific soil properties and As fractionation were analyzed, and changes in the health risk of soil As were accurately assessed by means of advanced in vivo mice model and in vitro PBET-SHIME model. Results showed that the application of CaAl-LDH significantly increased soil pH and concentration of Fe and Al oxides, and effectively converted active As fractions into the most stable residual fraction, guaranteeing long-term remediation stability. Based on in vivo test, As relative bioavailability was significantly reduced by 37.75%. Based on in vitro test, As bioaccessibility in small intestinal and colon phases was significantly reduced by 25.65% and 28.57%, respectively. Furthermore, As metabolism (reduction and methylation) by the gut microbiota inhabiting colon was clearly observed. After immobilisation with CaAl-LDH, the concentration of bioaccessible As(Ⅴ) in the colon fluid was significantly reduced by 61.91%, and organic As (least toxic MMA(V) and DMA(V)) became the main species, which further reduced the health risk of soil As. In summary, CaAl-LDH proved to be a feasible option for immobilisation remediation of As-contaminated soils, and considerable progress was made in relevant health risk assessment.


Assuntos
Arsênio , Poluentes do Solo , Animais , Humanos , Camundongos , Arsênio/química , Disponibilidade Biológica , Poluentes do Solo/análise , Solo/química , Medição de Risco
14.
Nano Lett ; 24(13): 3866-3873, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38442405

RESUMO

The low wear resistance of macroscale graphene coatings does not match the ultrahigh mechanical strength and chemical inertness of the graphene layer itself; however, the wear mechanism responsible for this issue at low mechanical stress is still unclear. Here, we demonstrate that the susceptibility of the graphene monolayer to wear at its atomic step edges is governed by the mechanochemistry of frictional interfaces. The mechanochemical reactions activated by chemically active SiO2 microspheres result in atomic attrition rather than mechanical damage such as surface fracture and folding by chemically inert diamond tools. Correspondingly, the threshold contact stress for graphene edge wear decreases more than 30 times to the MPa level, and mechanochemical wear can be described well with the mechanically assisted Arrhenius-type kinetic model, i.e., exponential dependence of the removal rate on the contact stress. These findings provide a strategy for improving the antiwear of graphene-based materials by reducing the mechanochemical interactions at tribological interfaces.

15.
Food Funct ; 15(7): 3479-3495, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38456359

RESUMO

Objective: The optimal probiotic supplementation in pregnant women has not been thoroughly evaluated. By employing a network meta-analysis (NMA) approach, we compared the effectiveness of different probiotic supplementation strategies for pregnant women. Methods: A comprehensive search across multiple databases was performed to identify studies comparing the efficacy of probiotic supplements with each other or the control (placebo) among pregnant women. Results: This NMA, including 32 studies, systematically evaluated 6 probiotic supplement strategies: Lactobacillus, Lacticaseibacillus rhamnosus and Bifidobacterium (LRB), Lactobacillus acidophilus and Bifidobacterium (LABB), Lactobacillus acidophilus, Lacticaseibacillus casei, and Bifidobacterium bifidum (LLB), multi-combination of four probiotics (MP1), and multi-combination of six or more probiotics (MP2). Among these strategies, LLB, MP1, and MP2 all contain LABB. The NMA findings showed that MP1 was the most effective in reducing fasting blood sugar (FBS) (surface under the cumulative ranking curve [SUCRA]: 80.5%). In addition, MP2 was the most efficacious in lowering the homeostasis model assessment of insulin resistance (HOMA-IR) (SUCRA: 89.1%). LABB was ranked as the most effective in decreasing low-density lipoprotein cholesterol (LDLC) (SUCRA: 95.5%), total cholesterol (TC) (SUCRA: 95.5%), and high-sensitivity C-reactive protein (hs-CRP) (SUCRA: 94.8%). Moreover, LLB was ranked as the most effective in raising total antioxidant capacity (TAC) (SUCRA: 98.5%). Conclusion: Multi-combination of probiotic strains, especially those strategies containing LABB, may be more effective than a single probiotic strain in glycolipid metabolism, inflammation, and oxidative stress of pregnant women.


Assuntos
Gestantes , Probióticos , Humanos , Feminino , Gravidez , Glicemia/metabolismo , Lactobacillus acidophilus/metabolismo , Estresse Oxidativo , Inflamação , LDL-Colesterol/metabolismo
16.
Med Res Rev ; 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38515232

RESUMO

Atropisomerism, an expression of axial chirality caused by limited bond rotation, is a prominent aspect within the field of medicinal chemistry. It has been shown that atropisomers of a wide range of compounds, including established FDA-approved drugs and experimental molecules, display markedly different biological activities. The time-dependent reversal of chirality in atropisomers poses complexity and obstacles in the process of drug discovery and development. Nonetheless, recent progress in understanding atropisomerism and enhanced characterization methods have greatly assisted medicinal chemists in the effective development of atropisomeric drug molecules. This article provides a comprehensive review of their special design thoughts, synthetic routes, and biological activities, serving as a reference for the synthesis and biological evaluation of bioactive atropisomers in the future.

17.
Ann Bot ; 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38507570

RESUMO

BACKGROUNDS AND AIMS: The hypothesis that plants evolve features that protect accessible pollen from consumption by flower visitors remains poorly understood. METHODS: To explore potential chemical defenses against pollen consumption, we examined the pollinator assemblage, foraging behaviour, visitation frequency and pollen transfer efficiency in Rhododendron molle, a highly toxic shrub containing Rhodojaponin III. Nutrient (protein and lipid) and toxic components in pollen and other tissues were measured. KEY RESULTS: Overall in the five populations, floral visits by butterflies and bumblebees were relatively more frequent than visits by honeybees. All foraged for nectar but not pollen. Butterflies did not differ from bumblebees in the amount of pollen removed per visit, but deposited more pollen per visit. Pollination experiments indicated that R. molle was self-compatible, but both fruit and seed production were pollen limited. Our analysis indicated that the pollen was not protein-poor and had a higher concentration of the toxic compound Rhodojaponin III than petals and leaves, which compound was undetectable in nectar. CONCLUSION: Pollen toxicity in Rhododendron flowers may discourage pollen robbers (bees) from taking the freely accessible pollen grains, while the toxin-free nectar rewards effective pollinators, promoting pollen transfer. This preliminary study supports the hypothesis that chemical defense in pollen would be likely to evolve in species without physical protection from pollinivores.

18.
Org Lett ; 26(10): 2103-2107, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38443201

RESUMO

A chemical synthesis of a unique nanosaccharide fragment from Helicobacter pylori lipopolysaccharide was achieved via a convergent glycosylation method. Challenges involved in the synthesis include the highly stereoselective construction of ß-3-deoxy-d-manno-oct-2-ulosonic acid (Kdo) and two 1,2-cis-glycosidic linkages, as well as the formation of a branched 2,7-disubstituted heptose subunit. Hydrogen-bond mediated aglycone delivery strategy and benzoyl-directing remote participation effect were employed, respectively, for the efficient generation of the desired ß-Kdo glycoside and 1,2-cis-α-l-fucoside/d-glucoside. Moreover, the key branched framework was successfully established through a [(7 + 1) + 1] assembly approach involving the stepwise glycosylation of the heptasaccharide alcohol with two monosaccharide donors. The synthesized 1 containing a propylamine linker at the reducing end can be covalently bound to a carrier protein for further immunological studies.


Assuntos
Glicosídeos , Lipopolissacarídeos , Lipopolissacarídeos/química , Glicosídeos/química
19.
Nat Commun ; 15(1): 2609, 2024 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-38521788

RESUMO

Insulin receptor (IR) controls growth and metabolism. Insulin-like growth factor 2 (IGF2) has different binding properties on two IR isoforms, mimicking insulin's function. However, the molecular mechanism underlying IGF2-induced IR activation remains unclear. Here, we present cryo-EM structures of full-length human long isoform IR (IR-B) in both the inactive and IGF2-bound active states, and short isoform IR (IR-A) in the IGF2-bound active state. Under saturated IGF2 concentrations, both the IR-A and IR-B adopt predominantly asymmetric conformations with two or three IGF2s bound at site-1 and site-2, which differs from that insulin saturated IR forms an exclusively T-shaped symmetric conformation. IGF2 exhibits a relatively weak binding to IR site-2 compared to insulin, making it less potent in promoting full IR activation. Cell-based experiments validated the functional importance of IGF2 binding to two distinct binding sites in optimal IR signaling and trafficking. In the inactive state, the C-terminus of α-CT of IR-B contacts FnIII-2 domain of the same protomer, hindering its threading into the C-loop of IGF2, thus reducing the association rate of IGF2 with IR-B. Collectively, our studies demonstrate the activation mechanism of IR by IGF2 and reveal the molecular basis underlying the different affinity of IGF2 to IR-A and IR-B.


Assuntos
Fator de Crescimento Insulin-Like II , Receptor de Insulina , Humanos , Insulina/metabolismo , Fator de Crescimento Insulin-Like II/metabolismo , Isoformas de Proteínas/metabolismo , Receptor de Insulina/metabolismo
20.
Eur J Pediatr ; 183(4): 1871-1880, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38300364

RESUMO

Immunoglobulin A vasculitis(IgAV) is the most common form of systemic vasculitis affecting children. To date, cardiac involvement in pediatric IgAV has not been fully investigated and its prevalence may be underestimated. This study aims to reveal the clinical and laboratory characteristics of cardiac involvement in pediatric IgAV and further determine its risk factors. A total of 1451 children with IgAV were recruited between January 2016 and December 2022. According to the severity of cardiac involvement, the patients were divided into the myocarditis/suspected myocarditis group, cardiac abnormalities group, and non-cardiac involvement group. Demographic, clinical, and laboratory characteristics were retrospectively extracted from the individual data collected in the medical records. Among the 1451 pediatric IgAV patients, 179 (12.3%) were identified with cardiac involvement, including 154 (10.6%) with cardiac abnormalities and 25 (1.7%) with myocarditis/suspected myocarditis. Cardiac involvement in pediatric IgAV mainly manifested as elevated cardiac biomarker levels (n = 162), electrocardiogram abnormalities (n = 46), and echocardiogram/chest X-ray abnormalities (n = 15); however, cardiac-related symptoms were only observed in 15.1% of patients with cardiac involvement. Multivariate analysis demonstrated that interval from disease onset to diagnosis > 7 days (OR, 2.157; 95% CI, 1.523-3.057; p < 0.001), IgAV with multi-organ involvement (OR, 1.806; 95% CI, 1.242-2.627; p = 0.002), and elevated D-dimer levels (OR, 1.939; 95% CI, 1.259-2.985; p < 0.001) were independent risk factors for cardiac involvement in pediatric IgAV. The length of hospital stay was significantly longer in the myocarditis/suspected myocarditis group compared with the other two groups (p < 0.05).     Conclusion: This study suggests that cardiac involvements in pediatric IgAV is non-negligible, and cardiac involvement is associated with interval from disease onset to diagnosis > 7 days, IgAV with multi-organ involvement, and elevated D-dimer levels. Severe cardiac involvement may affect the prognosis of pediatric IgAV. What is Known: • Immunoglobulin A vasculitis (IgAV) is the most common form of systemic vasculitis affecting children and adolescents, which exhibits diverse clinical manifestations. Cases of severe IgAV complicated by cardiac involvement have been anecdotally reported. What is New: • The present study suggests that cardiac involvements in pediatric IgAV is non-negligible, and cardiac involvement is associated with interval from disease onset to diagnosis > 7 days, IgAV with multi-organ involvement, and elevated D-dimer levels. Severe cardiac involvement may affect the prognosis of pediatric IgAV.


Assuntos
Vasculite por IgA , Miocardite , Vasculite Sistêmica , Adolescente , Humanos , Criança , Estudos Retrospectivos , Miocardite/diagnóstico , Miocardite/etiologia , Imunoglobulina A , Vasculite por IgA/complicações , Vasculite Sistêmica/complicações , Fatores de Risco
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