Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
1.
Acc Chem Res ; 56(24): 3626-3639, 2023 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-38059474

RESUMO

ConspectusMacrocyclic receptors can serve as alternatives to natural recognition systems as recognition tools. They provide effectively preorganized cavities to encapsulate guests via host-guest interactions, thereby affecting the physiochemical properties of the guests. Macrocyclic receptors exhibit chemical and thermal stabilities higher than those of natural receptors and thus are expected to resist degradation inside the body. This reduces the risk of harmful degradation byproducts and ensures optimal levels of effectiveness. Macrocyclic receptors have precise molecular weights and well-defined structures; this ensures their batch-to-batch reproducibility, which is critical for ensuring quality and effectiveness levels. Moreover, macrocyclic receptors exhibit broad modification tunabilities, rendering them adaptable to various guests. Molecular recognition is the basis of numerous biological processes. Macrocyclic receptors may display considerable potential for application in diagnosing and treating diseases, depending on the host-guest recognition of bioactive molecules. However, the binding affinities and selectivities of macrocyclic receptors toward bioactive molecules are generally insufficient, which may lead to problems such as low diagnosis accuracies, off-target leaking, and interference with normal functions. Therefore, addressing the challenge of the strong and specific complexation of bioactive molecules and macrocyclic receptors is imperative.To overcome this challenge, we proposed the innovative strategies of longitudinal cavity extension and coassembled heteromultivalent recognition for application in the recognition of small molecules and biomacromolecules, respectively. The deepened cavity provides a stronger hydrophobic effect and a larger interaction area while maintaining the framework rigidity. By coassembling two macrocyclic amphiphiles into one ensemble, we achieved the desired heteromultivalent recognition. This strategy affords the necessary binding properties while preventing the requirement of tedious steps and site mismatch in covalent synthesis. Using these two strategies, we achieved specific and strong binding of macrocyclic receptors to various bioactive molecules including biomarkers, drugs, and disease-related peptides/proteins. We then applied these macrocyclic receptor-based recognition systems in biosensing and bioimaging, drug delivery, and therapeutics.In this Account, we summarize the strategies we used in the recognition of small molecules and biomacromolecules. Thereafter, we discuss their applications in precision medicine, involving the (1) sensing of biomarkers and imaging of lesion sites, which are critical in the early screening of diseases and accurate diagnoses; (2) precise loading and targeted delivery of drugs, which are crucial in improving their therapeutic efficacies and reducing their side effects; and (3) capture and removal of disease-related biomacromolecules, which are significant for precise intervention in life processes. Finally, we propose recommendations for the further development of macrocyclic receptor-based recognition systems in biomedicine. Macrocyclic receptors exhibit considerable potential for research, and continued investigation may not only expand the applications of supramolecular chemistry but also open novel avenues for the development of precision medicine.


Assuntos
Sistemas de Liberação de Medicamentos , Medicina de Precisão , Reprodutibilidade dos Testes , Sistemas de Liberação de Medicamentos/métodos , Preparações Farmacêuticas , Biomarcadores
2.
Sensors (Basel) ; 24(12)2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38931527

RESUMO

The identification and detection of pesticides is crucial to protecting both the environment and human health. However, it can be challenging to conveniently and rapidly differentiate between different types of pesticides. We developed a supramolecular fluorescent sensor array, in which calixarenes with broad-spectrum encapsulation capacity served as recognition receptors. The sensor array exhibits distinct fluorescence change patterns for seven tested pesticides, encompassing herbicides, insecticides, and fungicides. With a reaction time of just three minutes, the sensor array proves to be a rapid and efficient tool for the discrimination of pesticides. Furthermore, this supramolecular sensing approach can be easily extended to enable real-time and on-site visual detection of varying concentrations of imazalil using a smartphone with a color scanning application. This work not only provides a simple and effective method for pesticide identification and quantification, but also offers a versatile and advantageous platform for the recognition of other analytes in relevant fields.


Assuntos
Calixarenos , Praguicidas , Calixarenos/química , Praguicidas/análise , Técnicas Biossensoriais/métodos , Smartphone , Espectrometria de Fluorescência/métodos
3.
Molecules ; 27(9)2022 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-35566317

RESUMO

Excessive inflammatory reaction aggravates brain injury and hinders the recovery of neural function in nervous system diseases. Microglia, as the major players of neuroinflammation, control the progress of the disease. There is an urgent need for effective non-invasive therapy to treat neuroinflammation mediated by microglia. However, the lack of specificity of anti-inflammatory agents and insufficient drug dose penetrating into the brain lesion area are the main problems. Here, we evaluated a series of calixarenes and found that among them the self-assembling architecture of amphiphilic sulfonatocalix[8]arene (SC8A12C) had the most potent ability to suppress neuroinflammation in vitro and in vivo. Moreover, SC8A12C assemblies were internalized into microglia through macropinocytosis. In addition, after applying the SC8A12C assemblies to the exposed brain tissue, we observed that SC8A12C assemblies penetrated into the brain parenchyma and eliminated the inflammatory factor storm, thereby restoring neurobiological functions in a mouse model of traumatic brain injury.


Assuntos
Lesões Encefálicas Traumáticas , Calixarenos , Animais , Lesões Encefálicas Traumáticas/patologia , Calixarenos/farmacologia , Calixarenos/uso terapêutico , Modelos Animais de Doenças , Inflamação/tratamento farmacológico , Inflamação/patologia , Camundongos , Camundongos Endogâmicos C57BL , Microglia , Doenças Neuroinflamatórias
4.
J Viral Hepat ; 28(3): 577-578, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33382164

RESUMO

We are glad to respond to the concerns of Drs. Levy and Terrault about our articles on the mother-to-child transmission (MTCT) of hepatitis B virus (HBV) in HBeAg-positive mothers. We agree with Drs. Levy and Terrault that antiviral therapy of HBV during pregnancy could effectively decrease the MTCT, and this strategy has been recommended by WHO for pregnant women with a high viral load. However, the long-term influences of the abrupt cessation of antiretroviral drugs in mothers and prenatal exposure to antiviral drugs in newborns are not completely understood and are still under investigation. And not all pregnant mothers would accept this regiment due to the medication availability and individual willingness. It makes sense to study the influential factors on MTCT among mothers with high-risk transmission but not taking antiviral drugs. Despite the relatively large number of subjects included in our cohort (N = 857), post hoc power computation shows that the test efficacy is far from adequate to detect the association between delivery mode or feeding type and HBV MTCT. Therefore, we summarized the relevant studies to reach a relatively reasonable conclusion in HBsAg- and HBeAg-positive pregnant mothers not taking antiviral drugs. We provide an alternative option for HBsAg- and HBeAg-positive pregnant mothers who cannot access or defer to antiviral therapy during pregnancy to reduce the risk of HBV transmission to their offspring.


Assuntos
Preparações Farmacêuticas , Complicações Infecciosas na Gravidez , Cesárea , Criança , Estudos de Coortes , Feminino , Antígenos de Superfície da Hepatite B , Antígenos E da Hepatite B , Vírus da Hepatite B , Humanos , Recém-Nascido , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Mães , Gravidez , Complicações Infecciosas na Gravidez/tratamento farmacológico , Complicações Infecciosas na Gravidez/prevenção & controle , Estudos Prospectivos
5.
Angew Chem Int Ed Engl ; 60(6): 2768-2794, 2021 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-31965674

RESUMO

Calixarenes (CAs), representing the third generation of supramolecular hosts and one of the most widely studied macrocyclic scaffolds, offer (almost) unlimited structure and application possibilities due to their ease of modification, which allows one to establish a large molecular library as a material basis for diverse biomedical applications. Moreover, CAs and their derivatives engage in various noncovalent interactions for the facile recognition of guests including bioactive molecules and are also important building blocks for the fabrication of supramolecular architectures. In view of their molecular recognition and self-assembly properties, CAs are extensively applied in biosensing, bioimaging, and drug/gene delivery. Additionally, some CA derivatives exhibit biological activities and can therefore be used as new therapeutic agents. Herein, we summarize the diverse biomedical applications of CAs including in vitro diagnosis (biosensing), in vivo diagnosis (bioimaging), and therapy.


Assuntos
Técnicas Biossensoriais/métodos , Calixarenos/química , Portadores de Fármacos/química , Imagem Óptica/métodos , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Biomarcadores/análise , Calixarenos/farmacologia , Técnicas de Transferência de Genes , Humanos , Nanopartículas/química
6.
Angew Chem Int Ed Engl ; 60(4): 1875-1882, 2021 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-33051947

RESUMO

Lysine (K) is an important target residue for protein and peptide delivery across membranes. K is the most frequently exposed residue in proteins, leading to high demand for the development of K-compatible transport activators. However, designing activators for K-rich peptides and proteins is more challenging than for arginine-rich species because of the kosmotropic nature of K and its recognition difficulty. In this study, we designed a new amphiphilic sulfonatocalix[5]arene (sCx5-6C) as a K-compatible transport activator. sCx5-6C was tailored with two key elements, recognition of K and the ability to embed into membranes. We measured the membrane transport efficiencies of α-poly-l-lysine, heptalysine, and histones across artificial membranes and of α-poly-l-lysine into live cells, activated by sCx5-6C. The results demonstrate that sCx5-6C acts as an efficient activator for translocating K-rich peptides and proteins, which cannot be achieved by known arginine-compatible activators.


Assuntos
Calixarenos/química , Lisina/metabolismo , Peptídeos/metabolismo , Proteínas/metabolismo , Ácidos Sulfônicos/química , Membrana Celular/metabolismo , Membranas Artificiais , Transporte Proteico
7.
J Viral Hepat ; 27(10): 1032-1043, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32362050

RESUMO

The study aimed to assess whether caesarean section and nonbreastfeeding can prevent mother-to-child transmission (MTCT) in HBsAg- and HBeAg-positive mothers via a cohort study and a meta-analysis. (1) Pregnant women who were positive for HBsAg and HBeAg and did not receive antiviral treatment during pregnancy were recruited from the First Hospital of Jilin University, Maternal and Child Health Care Center of Jiangsu and Henan from August 2009 to June 2015. Infants received active and passive immunity. (2) In addition, a systematic literature search was performed in the PubMed, Embase, Cochrane, China National Knowledge Infrastructure and Wanfang Chinese databases. The retrieval strategy was [("HBV" or "hepatitis b" or "hepatitis b virus") and ("mother-to-infant transmission" or "vertical transmission")]. Studies were screened, and data were extracted. The fixed-effect model was used to analyse the studies. A total of 852 mothers and 857 newborns were enrolled. At the age of 7 months, 41 infants (4.78%) were positive for HBsAg. Multivariate analysis showed that mothers with higher HBV DNA levels (>108  IU/mL; RR = 3.03, 95% CI: 1.41-6.52) were associated with an increased risk of infection. Although there was no statistical significance, caesarean section (RR = 0.61) and nonbreastfeeding (RR = 0.88) showed a tendency to reduce the risk of infection. (2) A total of 5726 studies were identified. Together with our study, 13 were included in the analysis of delivery mode, and 12 were included in the analysis of feeding mode. The risk of infection in the caesarean section group was lower than that in the vaginal delivery group (RR = 0.58, 95% CI: 0.46-0.74). In the analysis of feeding mode, the risk in the nonbreastfeeding group was significantly lower (RR = 0.74, 95% CI: 0.56-0.98). In conclusion, caesarean section and nonbreastfeeding reduced the risk of MTCT in infants of HBsAg- and HBeAg-positive mothers who did not receive antiviral therapy during pregnancy.


Assuntos
Hepatite B , Complicações Infecciosas na Gravidez , Cesárea , Estudos de Coortes , Feminino , Hepatite B/prevenção & controle , Antígenos de Superfície da Hepatite B , Antígenos E da Hepatite B , Vírus da Hepatite B , Humanos , Lactente , Recém-Nascido , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Mães , Gravidez , Complicações Infecciosas na Gravidez/prevenção & controle , Estudos Prospectivos
8.
J Am Chem Soc ; 141(51): 20137-20145, 2019 12 26.
Artigo em Inglês | MEDLINE | ID: mdl-31739668

RESUMO

The membrane transport mechanisms of cell-penetrating peptides (CPPs) are still controversial, and reliable assays to report on their internalization in model membranes are required. Herein, we introduce a label-free, fluorescence-based method to monitor membrane transport of peptides in real time. For this purpose, a macrocyclic host and a fluorescent dye forming a host-dye reporter pair are encapsulated inside phospholipid vesicles. Internalization of peptides, which can bind to the supramolecular host, leads to displacement of the dye from the host, resulting in a fluorescence change that signals the peptide uptake and, thus, provides unambiguous evidence for their transport through the membrane. The method was successfully validated with various established CPPs, including the elusive peptide TP2, in the presence of counterion activators of CPPs, and with a calixarene-based supramolecular membrane transport system. In addition, transport experiments with encapsulated host-dye reporter pairs are not limited to large unilamellar vesicles (LUVs) but can also be used with giant unilamellar vesicles (GUVs) and fluorescence microscopy imaging.


Assuntos
Peptídeos Penetradores de Células/metabolismo , Fluorescência , Corantes Fluorescentes/metabolismo , Compostos Macrocíclicos/metabolismo , Lipossomas Unilamelares/metabolismo , Transporte Biológico , Peptídeos Penetradores de Células/química , Corantes Fluorescentes/química , Compostos Macrocíclicos/química , Microscopia de Fluorescência , Estrutura Molecular , Imagem Óptica , Lipossomas Unilamelares/química
9.
BMC Infect Dis ; 18(1): 274, 2018 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-29898681

RESUMO

BACKGROUND: Infants born to hepatitis B surface antigen (HBsAg) positive mothers are at a higher risk for Hepatitis B virus (HBV) infection. Host genetic background plays an important role in determining the strength of immune response to vaccination. We conducted this study to investigate the association between Tumor necrosis factor (TNF) and Mitogen-activated protein kinase eight (MAPK8) polymorphisms and low response to hepatitis B vaccines. METHODS: A total of 753 infants of HBsAg positive and hepatitis Be antigen (HBeAg) negative mothers from the prevention of mother-to-infant transmission of HBV cohort were included. Five tag single nucleotide polymorphism (SNPs) (rs1799964, rs1800629, rs3093671, rs769177 and rs769178) in TNF and two tag SNPs (rs17780725 and rs3827680) in MAPK8 were genotyped using the MassARRAY platform. RESULTS: A higher percentage of breastfeeding (P = 0.013) and a higher level of Ab titers were observed in high responders (P < 0.001). The MAPK8 rs17780725 AA genotype increased the risk of low response to hepatitis B vaccines (OR = 3.176, 95% CI: 1.137-8.869). Additionally, subjects with the AA genotype may have a lower Ab titer than subjects with GA or GG genotypes (P = 0.051). Compared to infants who were breastfed, infants who were not breastfed had an increased risk of low response to hepatitis B vaccine (OR = 2.901, 95% CI:1.306-6.441). CONCLUSIONS: MAPK8 polymorphisms are associated with immune response to HBV vaccinations in infants of HBsAg(+)/HBeAg(-) mothers.


Assuntos
Antígenos de Superfície da Hepatite B/sangue , Vacinas contra Hepatite B/imunologia , Antígenos E da Hepatite B/sangue , Hepatite B/prevenção & controle , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Proteína Quinase 8 Ativada por Mitógeno/genética , Adulto , Alelos , Feminino , Genótipo , Haplótipos , Hepatite B/imunologia , Humanos , Imunidade Inata , Lactente , Recém-Nascido , Masculino , Mães , Polimorfismo de Nucleotídeo Único , Gravidez , Fator de Necrose Tumoral alfa/genética
11.
Angew Chem Int Ed Engl ; 56(49): 15742-15745, 2017 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-29024239

RESUMO

Phosphorylation and dephosphorylation of peptides by kinases and phosphatases is essential for signal transduction in biological systems, and many diseases involve abnormal activities of these enzymes. Herein, we introduce amphiphilic calixarenes as key components for supramolecular, phosphorylation-responsive membrane transport systems. Dye-efflux experiments with liposomes demonstrated that calixarenes are highly active counterion activators for established cell-penetrating peptides, with EC50 values in the low nanomolar range. We have now found that they can even activate membrane transport of short peptide substrates for kinases involved in signal transduction, whereas the respective phosphorylated products are much less efficiently transported. This allows regulation of membrane transport activity by protein kinase A (PKA) and protein kinase C (PKC), as well as monitoring of their activity in a label-free kinase assay.


Assuntos
Peptídeos/metabolismo , Transporte Biológico , Calixarenos/química , Calixarenos/metabolismo , Peptídeos/química , Fosforilação , Tensoativos/química , Tensoativos/metabolismo
12.
Adv Mater ; 36(28): e2401918, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38662940

RESUMO

The complex pathologies in Alzheimer's disease (AD) severely limit the effectiveness of single-target pharmic interventions, thus necessitating multi-pronged therapeutic strategies. While flexibility is essentially demanded in constructing such multi-target systems, for achieving optimal synergies and also accommodating the inherent heterogeneity within AD. Utilizing the dynamic reversibility of supramolecular strategy for conferring sufficient tunability in component substitution and proportion adjustment, amphiphilic calixarenes are poised to be a privileged molecular tool for facilely achieving function integration. Herein, taking ß-amyloid (Aß) fibrillation and oxidative stress as model combination pattern, a supramolecular multifunctional integration is proposed by co-assembling guanidinium-modified calixarene with ascorbyl palmitate and loading dipotassium phytate within calixarene cavity. Serial pivotal events can be simultaneously addressed by this versatile system, including 1) inhibition of Aß production and aggregation, 2) disintegration of Aß fibrils, 3) acceleration of Aß metabolic clearance, and 4) regulation of oxidative stress, which is verified to significantly ameliorate the cognitive impairment of 5×FAD mice, with reduced Aß plaque content, neuroinflammation, and neuronal apoptosis. Confronted with the extremely intricate clinical realities of AD, the strategy presented here exhibits ample adaptability for necessary alterations on combinations, thereby may immensely expedite the advancement of AD combinational therapy through providing an exceptionally convenient platform.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Calixarenos , Nanopartículas , Estresse Oxidativo , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Animais , Peptídeos beta-Amiloides/metabolismo , Peptídeos beta-Amiloides/antagonistas & inibidores , Peptídeos beta-Amiloides/química , Nanopartículas/química , Camundongos , Calixarenos/química , Estresse Oxidativo/efeitos dos fármacos , Humanos
13.
Adv Sci (Weinh) ; 11(24): e2309517, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38647405

RESUMO

Intravenous thrombolysis with recombinant tissue plasminogen activator (rtPA) is the primary treatment for ischemic stroke. However, rtPA treatment can substantially increase blood-brain barrier (BBB) permeability and susceptibility to hemorrhagic transformation. Herein, the mechanism underlying the side effects of rtPA treatment is investigated and demonstrated that ferroptosis plays an important role. The ferroptosis inhibitor, liproxstatin-1 (Lip) is proposed to alleviate the side effects. A well-designed macrocyclic carrier, glucose-modified azocalix[4]arene (GluAC4A), is prepared to deliver Lip to the ischemic site. GluAC4A bound tightly to Lip and markedly improved its solubility. Glucose, modified at the upper rim of GluAC4A, imparts BBB targeting to the drug delivery system owing to the presence of glucose transporter 1 on the BBB surface. The responsiveness of GluAC4A to hypoxia due to the presence of azo groups enabled the targeted release of Lip at the ischemic site. GluAC4A successfully improved drug accumulation in the brain, and Lip@GluAC4A significantly reduced ferroptosis, BBB leakage, and neurological deficits induced by rtPA in vivo. These findings deepen the understanding of the side effects of rtPA treatment and provide a novel strategy for their effective mitigation, which is of great significance for the treatment and prognosis of patients with ischemic stroke.


Assuntos
Modelos Animais de Doenças , Sistemas de Liberação de Medicamentos , Ferroptose , AVC Isquêmico , Ativador de Plasminogênio Tecidual , Animais , Ferroptose/efeitos dos fármacos , Camundongos , AVC Isquêmico/tratamento farmacológico , Ativador de Plasminogênio Tecidual/farmacologia , Ativador de Plasminogênio Tecidual/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Masculino , Quinoxalinas , Compostos de Espiro
14.
Infect Drug Resist ; 16: 1849-1863, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37020796

RESUMO

Objective: The aim of this study was to analyze the prevalence of vaginal flora and drug resistance in bacterial vaginitis among girls. Methods: A total of 3099 girls (0-10 years old) with vaginitis who visited the Beijing Children's Hospital from January 2020 to December 2021 were included in the present study. The clinical data, results of bacterial culture of vaginal secretions, and drug sensitivity reports of the subjects were collected and analyzed. Results: Of the 3099 girls with vaginitis, 399 girls had a positive bacterial culture of vaginal secretions. Nineteen types of bacteria were cultured from the vaginal secretions of these 399 girls, with a total of 419 strains. The top three infective bacteria were Haemophilus influenzae (127 strains, 30.31%), Staphylococcus aureus (66 strains, 15.75%), and Streptococcus agalactiae (32 strains, 7.64%). Additionally, 20 girls were simultaneously infected with two types of bacteria. Staphylococcus aureus, Group G Streptococcus, Haemophilus parainfluenzae, and Pseudomonas aeruginosa more frequently occurred in mixed infections. The number and bacterial detection rate among school-age girls were higher than those of preschool-age girls. We found seasonal variation in infection rates, and vaginitis among girls was higher in summer. Recurrence of vaginitis in girls was not related to the type of pathogenic bacteria in the infection. Drug sensitivity analyses showed that the resistance rates of clindamycin and erythromycin were generally high, 70-100%. After the coronavirus disease 2019 outbreak, the resistance rates of some antibiotics had decreased to varying degrees. Conclusion: Improving the understanding of vaginal flora and drug resistance in girls with vaginitis will facilitate the selection of highly effective and sensitive antibacterial drugs and reduce the production of drug-resistant strains.

15.
Elife ; 122023 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-36799301

RESUMO

Mitochondrial dysfunction caused by aberrant Complex I assembly and reduced activity of the electron transport chain is pathogenic in many genetic and age-related diseases. Mice missing the Complex I subunit NADH dehydrogenase [ubiquinone] iron-sulfur protein 4 (NDUFS4) are a leading mammalian model of severe mitochondrial disease that exhibit many characteristic symptoms of Leigh Syndrome including oxidative stress, neuroinflammation, brain lesions, and premature death. NDUFS4 knockout mice have decreased expression of nearly every Complex I subunit. As Complex I normally contains at least 8 iron-sulfur clusters and more than 25 iron atoms, we asked whether a deficiency of Complex I may lead to iron perturbations, thereby accelerating disease progression. Consistent with this, iron supplementation accelerates symptoms of brain degeneration in these mice, while iron restriction delays the onset of these symptoms, reduces neuroinflammation, and increases survival. NDUFS4 knockout mice display signs of iron overload in the liver including increased expression of hepcidin and show changes in iron-responsive element-regulated proteins consistent with increased cellular iron that were prevented by iron restriction. These results suggest that perturbed iron homeostasis may contribute to pathology in Leigh Syndrome and possibly other mitochondrial disorders.


Iron is a mineral that contributes to many vital body functions. But as people age, it accumulates in many organs, including the liver and the brain. Excess iron accumulation is linked to age-related diseases like Parkinson's disease. Too much iron may contribute to harmful chemical reactions in the body. Usually, the body has systems in place to mitigate this harm, but these mechanisms may fail as people age. Uncontrolled iron accumulation may damage essential proteins, DNA and fats in the brain. These changes may kill brain cells causing neurodegenerative diseases like Parkinson's disease. Mitochondria, the cell's energy-producing factories, use and collect iron inside cells. As people age, mitochondria fail, which is also linked with age-related diseases. It has been unclear if mitochondrial failure may also contribute to iron accumulation and associated diseases like Parkinson's. Kelly et al. show that mitochondrial dysfunction causes iron accumulation and contributes to neurodegeneration in mice. In the experiments, Kelly et al. used mice with a mutation in a key-iron processing protein in mitochondria. These mice develop neurodegenerative symptoms and die early in life. Feeding the mice a high-iron diet accelerated the animals' symptoms. But providing them with an iron-restricted diet slowed their symptoms and extended their lives. Low-iron diets also slowed iron accumulation in the animal's liver and reduced brain inflammation. The experiments suggest that mitochondrial dysfunction contributes to both iron overload and brain degeneration. The next step for scientists is understanding the processes leading to mitochondrial dysfunction and iron accumulation. Then, scientists can determine if they can develop treatments targeting these processes. This research might lead to new treatments for Parkinson's disease or other age-related conditions caused by iron overload.


Assuntos
Doença de Leigh , Doenças Mitocondriais , Camundongos , Animais , Doença de Leigh/genética , Doença de Leigh/patologia , Ferro/metabolismo , Doenças Neuroinflamatórias , Doenças Mitocondriais/patologia , Mitocôndrias/metabolismo , Complexo I de Transporte de Elétrons/metabolismo , Camundongos Knockout , Mamíferos/metabolismo
16.
J Cardiothorac Surg ; 17(1): 233, 2022 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-36085208

RESUMO

BACKGROUNDS: Hyperlactatemia is a common metabolic disorder after cardiac surgery with cardiopulmonary bypass. Epinephrine use has been identified as a potential cause of increased lactate levels after cardiac surgery. Stress can lead to an increase in catecholamines, mainly epinephrine, in the body. Exogenous epinephrine causes hyperlactatemia, whereas endogenous epinephrine released by stress may have the same effect. Opioids are the most effective anesthetics to suppress the stress response in the body. The authors sought to provide evidence through a retrospective data analysis that helps investigate the relationship between intraoperative opioid dosage and postoperative lactic acidosis after cardiac surgery. METHODS: The clinical data of 215 patients who underwent valvular heart surgery with cardiopulmonary bypass from July 2016 to July 2019 were analyzed retrospectively. Blood lactate levels were measured at 0.1 h, 2 h, 4 h, and 8 h after surgery. Patients with continuous increases in lactate levels and lactate levels exceeding 5 mmol/L at two or more time points were included in the lactic acidosis group, whereas the other patients were included in the control group. First, univariate correlation analysis was used to identify parameters that were significantly different between the two groups, and then multivariate regression analysis was conducted to elucidate the independent risk factors for lactic acidosis. Fifty-one pairs of patients were screened by propensity score matching analysis (PSM). Then, lactic acid levels at four time points in both groups were analyzed by repeated measures ANOVA. RESULTS: he EF (heart ejection fraction) (OR = 0.94, P = 0.003), aortic occlusion time (OR = 10.17, P < 0.001) and relative infusion rate (OR = 2.23, P = 0.01) of sufentanil was an independent risk factor for lactic acidosis after valvular heart surgery. The patients were further divided into two groups with the mean sufentanil infusion rate as the reference point. The data were filtered with PSM (Propensity Score Matching). Lactic acid values in both groups peaked at 4 h after surgery and then declined. The rate of lactic acid decline was significantly faster in the group with a higher sufentanil dosage than in the lower group. The difference was statistically significant (P < 0.05). There was also a significant difference in lactic acid levels at the four time points (0.1 h, 2 h, 4 h and 8 h after surgery) in both groups (P < 0.001). CONCLUSION: The inadequate intraoperative infusion rate of sufentanil is an independent risk factor for lactic acidosis after heart valve surgery. The possibility of lactic acidosis caused by this factor after cardiac surgery should be considered, which is helpful for postoperative patient management.


Assuntos
Acidose Láctica , Procedimentos Cirúrgicos Cardíacos , Hiperlactatemia , Acidose Láctica/induzido quimicamente , Analgésicos Opioides/efeitos adversos , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Epinefrina , Valvas Cardíacas/cirurgia , Humanos , Hiperlactatemia/induzido quimicamente , Ácido Láctico , Masculino , Estudos Retrospectivos , Fatores de Risco , Sufentanil/efeitos adversos
17.
Nat Commun ; 13(1): 4293, 2022 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-35879312

RESUMO

Differential sensing, which discriminates analytes via pattern recognition by sensor arrays, plays an important role in our understanding of many chemical and biological systems. However, it remains challenging to develop new methods to build a sensor unit library without incurring a high workload of synthesis. Herein, we propose a supramolecular approach to construct a sensor unit library by taking full advantage of recognition and assembly. Ten sensor arrays are developed by replacing the building block combinations, adjusting the ratio between system components, and changing the environment. Using proteins as model analytes, we examine the discriminative abilities of these supramolecular sensor arrays. Then the practical applicability for discriminating complex analytes is further demonstrated using honey as an example. This sensor array construction strategy is simple, tunable, and capable of developing many sensor units with as few syntheses as possible.


Assuntos
Proteínas
18.
Zhonghua Xin Xue Guan Bing Za Zhi ; 39(2): 114-7, 2011 Feb.
Artigo em Zh | MEDLINE | ID: mdl-21426743

RESUMO

OBJECTIVE: To investigate the outcome of orthotopic heart transplantation for patient with end-stage hypertrophic cardiomyopathy. METHODS: This retrospective review analyzed the clinical data of nine patients (7 males) undergoing orthotopic heart transplantation for end-stage hypertrophic cardiomyopathy in our center. All patients received induced therapy protocols peri-operative and standard triple maintenance immunosuppressive therapy postoperative. RESULTS: One recipients developed acute renal failure due to renal artery embolism and allograft rejection in the early posttransplantive course, symptoms and signs were improved under continuous renal replacement therapy and steroid-pulse therapy, this patient died of sudden cardiac arrest at 32 months post transplantation. Another recipient developed demyelinating disease in frontal and parietal lobe and finally recovered with medical therapy. Eight patients survived the operation with good quality of life and there was no episode of rejection or infection or chronic graft arteriosclerosis during follow-up time. Three recipients developed left ventricular hypertrophy and there were no signs of grapg-vessel diseases in the survivals. CONCLUSION: Heart transplantation is the best therapeutic option for selected patients with end-stage hypertrophic cardiomyopathy.


Assuntos
Cardiomiopatia Hipertrófica/cirurgia , Transplante de Coração , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
19.
Adv Mater ; 33(40): e2104310, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34418189

RESUMO

Poisoning is a leading cause of admission to medical emergency departments and intensive care units. Supramolecular detoxification, which involves injecting supramolecular receptors that bind with toxins to suppress their biological activity, is an emerging strategy for poisoning treatment; it has few requirements and a broad application scope. However, it is still a formidable challenge to design supramolecular therapeutic materials as an antidote to macromolecular toxins, because the large size, flexible conformation, and presence of multiple and diverse binding sites of biomacromolecules hinder their recognition. Herein, a supramolecular antidote to macromolecular toxins is developed through the coassembly of macrocyclic amphiphiles, relying on heteromultivalent recognition between the coassembled components and toxic macromolecules. The coassembly of amphiphilic cyclodextrin and calixarene strongly and selectively captures melittin, a toxin studied herein; this imparts various therapeutic effects such as inhibiting the interactions of melittin with cell membranes, alleviating melittin cytotoxicity and hemolytic toxicity, reducing the mortality rate of melittin-poisoned mice, and mitigating damage to major organs. The use of the proposed antidote overcomes the limitation of supramolecular detoxification applicability to only small-molecular toxins. The antidote can also detoxify other macromolecular toxins as long as selective and strong binding is achieved because of the coassembling tunability.


Assuntos
Antídotos/química , Substâncias Macromoleculares/química , Meliteno/química , Animais , Antídotos/metabolismo , Antídotos/farmacologia , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Membrana Celular/química , Sobrevivência Celular/efeitos dos fármacos , Ciclodextrinas/química , Células HEK293 , Hemólise/efeitos dos fármacos , Humanos , Fígado/efeitos dos fármacos , Fígado/patologia , Substâncias Macromoleculares/metabolismo , Meliteno/metabolismo , Meliteno/farmacologia , Camundongos , Venenos de Aranha/química , Venenos de Aranha/farmacologia
20.
Chem Commun (Camb) ; 57(94): 12627-12630, 2021 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-34761762

RESUMO

Calixarenes are reportedly excellent activators that can remarkably improve the transport efficiencies of cell penetrating peptides. We employed eight calixarenes to systematically study the influence of structure on activation efficiency, which revealed that the scaffold, head group, and alkyl chain are all significant factors for activation efficiency by affecting affinities with the peptide and membrane.


Assuntos
Calixarenos/farmacologia , Peptídeos/metabolismo , Transporte Biológico/efeitos dos fármacos , Calixarenos/química , Avaliação Pré-Clínica de Medicamentos , Humanos , Estrutura Molecular
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA