RESUMO
Prions or prion-like aggregates such as those composed of PrP, α-synuclein, and tau are key features of proteinopathies such as prion, Parkinson's and Alzheimer's diseases, respectively. Their presence on solid surfaces may be biohazardous under some circumstances. PrP prions bound to solids are detectable by ultrasensitive real-time quaking-induced conversion (RT-QuIC) assays if the solids can be immersed in assay wells or the prions transferred to pads. Here we show that prion-like seeds can remain detectable on steel wires for at least a year, or even after enzymatic cleaning and sterilization. We also show that contamination of larger objects with pathological seeds of α-synuclein, tau, and PrP can be detected by simply assaying a sampling medium that has been transiently applied to the surface. Human α-synuclein seeds in dementia with Lewy bodies brain tissue were detected by α-synuclein RT-QuIC after drying of tissue dilutions with concentrations as low as 10-6 onto stainless steel. Tau RT-QuIC detected tau seeding activity on steel exposed to Alzheimer's disease brain tissue diluted as much as a billion fold. Prion RT-QuIC assays detected seeding activity on plates exposed to brain dilutions as extreme as 10-5-10-8 from prion-affected humans, sheep, cattle and cervids. Sampling medium collected from surgical instruments used in necropsies of sporadic Creutzfeldt-Jakob disease-infected transgenic mice was positive down to 10-6 dilution. Sensitivity for prion detection was not sacrificed by omitting the recombinant PrP substrate from the sampling medium during its application to a surface and subsequent storage as long as the substrate was added prior to performing the assay reaction. Our findings demonstrate practical prototypic surface RT-QuIC protocols for the highly sensitive detection of pathologic seeds of α-synuclein, tau, and PrP on solid objects.
Assuntos
Proteínas Priônicas , alfa-Sinucleína , Proteínas tau , Proteínas tau/metabolismo , alfa-Sinucleína/metabolismo , alfa-Sinucleína/análise , Humanos , Proteínas Priônicas/metabolismo , Animais , Camundongos , Encéfalo/metabolismo , Encéfalo/patologia , Príons/metabolismo , Doença por Corpos de Lewy/metabolismoRESUMO
Regulatory and effector cell responses to Plasmodium vivax, the most common human malaria parasite outside Africa, remain understudied in naturally infected populations. Here, we describe peripheral CD4+ T- and B-cell populations during and shortly after an uncomplicated P. vivax infection in 38 continuously exposed adult Amazonians. Consistent with previous observations, we found an increased frequency in CD4+ CD45RA- CD25+ FoxP3+ T regulatory cells that express the inhibitory molecule CTLA-4 during the acute infection, with a sustained expansion of CD21- CD27- atypical memory cells within the CD19+ B-cell compartment. Both Th1- and Th2-type subsets of CXCR5+ ICOShi PD-1+ circulating T follicular helper (cTfh) cells, which are thought to contribute to antibody production, were induced during P. vivax infection, with a positive correlation between overall cTfh cell frequency and IgG antibody titers to the P. vivax blood-stage antigen MSP119 . We identified significant changes in cell populations that had not been described in human malaria, such as an increased frequency of CTLA-4+ T follicular regulatory cells that antagonize Tfh cells, and a decreased frequency of circulating CD24hi CD27+ B regulatory cells in response to acute infection. In conclusion, we disclose a complex immunoregulatory network that is critical to understand how naturally acquired immunity develops in P. vivax malaria.
Assuntos
Malária Vivax , Plasmodium vivax , Adulto , Humanos , Plasmodium vivax/fisiologia , Antígeno CTLA-4 , Linfócitos T Auxiliares-Indutores , Linfócitos T CD4-PositivosRESUMO
A group of Gram-negative plant-associated diazotrophic bacteria belonging to the genus Nitrospirillum was investigated, including both previously characterized and newly isolated strains from diverse regions and biomes, predominantly in Brazil. Phylogenetic analysis of 16S rRNA and recA genes revealed the formation of a distinct clade consisting of thirteen strains, separate from the formally recognized species N. amazonense (the closest species) and N. iridis. Comprehensive taxonomic analyses using the whole genomes of four strains (BR 11140T = AM 18T = Y-2T = DSM 2788T = ATCC 35120T, BR 11142T = AM 14T = Y-1T = DSM 2787T = ATCC 35119T, BR 11145 = CBAmC, and BR 12005) supported the division of these strains into two species: N. amazonense (BR 11142 T and BR 12005) and a newly proposed species (BR 11140 T and BR 11145), distinct from N. iridis. The phylogenomic analysis further confirmed the presence of the new Nitrospirillum species. Additionally, MALDI-TOF MS analysis of whole-cell mass spectra provided further evidence for the differentiation of the proposed Nitrospirillum species, separate from N. amazonense. Analysis of chemotaxonomy markers (i.e., genes involved in fatty acid synthesis, metabolism and elongation, phospholipid synthesis, and quinone synthesis) revealed that the new species highlights high similarity and evolutionary convergence with other Nitrospirillum species. This new species exhibited nitrogen fixation ability in vitro, it has similar NifHDK protein phylogeny position with the closest species, lacked denitrification capability, but possessed the nosZ gene, enabling N2O reduction, distinguishing it from the closest species. Despite being isolated from diverse geographic regions, soil types, and ecological niches, no significant phenotypic or physiological differences were observed between the proposed new species and N. amazonense. Based on these findings, a new species, Nitrospirillum viridazoti sp. nov., was classified, with the strain BR 11140T (DSM 2788T, ATCC 35120T) designated as the type strain.
Assuntos
Nitrogênio , Poaceae , Filogenia , RNA Ribossômico 16S/genética , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
Trimethylguanosine synthase 1 (TGS1) is a highly conserved enzyme that converts the 5'-monomethylguanosine cap of small nuclear RNAs (snRNAs) to a trimethylguanosine cap. Here, we show that loss of TGS1 in Caenorhabditis elegans, Drosophila melanogaster and Danio rerio results in neurological phenotypes similar to those caused by survival motor neuron (SMN) deficiency. Importantly, expression of human TGS1 ameliorates the SMN-dependent neurological phenotypes in both flies and worms, revealing that TGS1 can partly counteract the effects of SMN deficiency. TGS1 loss in HeLa cells leads to the accumulation of immature U2 and U4atac snRNAs with long 3' tails that are often uridylated. snRNAs with defective 3' terminations also accumulate in Drosophila Tgs1 mutants. Consistent with defective snRNA maturation, TGS1 and SMN mutant cells also exhibit partially overlapping transcriptome alterations that include aberrantly spliced and readthrough transcripts. Together, these results identify a neuroprotective function for TGS1 and reinforce the view that defective snRNA maturation affects neuronal viability and function.
Assuntos
Metiltransferases , Neurônios Motores , RNA Nuclear Pequeno , Animais , Humanos , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Drosophila/genética , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Células HeLa , Neurônios Motores/metabolismo , Neurônios Motores/patologia , Fenótipo , RNA Nuclear Pequeno/metabolismo , Metiltransferases/metabolismoRESUMO
Doxorubicin is an effective drug for cancer treatment; however, cardiotoxicity limits its use. Cardiotoxicity pathophysiology is multifactorial. GLP-1 analogues have been shown to reduce oxidative stress and inflammation. In this study, we evaluated the effect of pretreatment with liraglutide on doxorubicin-induced acute cardiotoxicity. A total of 60 male Wistar rats were allocated into four groups: Control (C), Doxorubicin (D), Liraglutide (L), and Doxorubicin + Liraglutide (DL). L and DL received subcutaneous injection of liraglutide 0.6 mg/kg daily, while C and D received saline for 2 weeks. Afterwards, D and DL received a single intraperitoneal injection of doxorubicin 20 mg/kg; C and L received an injection of saline. Forty-eight hours after doxorubicin administration, the rats were subjected to echocardiogram, isolated heart functional study, and euthanasia. Liraglutide-treated rats ingested significantly less food and gained less body weight than animals that did not receive the drug. Rats lost weight after doxorubicin injection. At echocardiogram and isolated heart study, doxorubicin-treated rats had systolic and diastolic function impairment. Myocardial catalase activity was statistically higher in doxorubicin-treated rats. Myocardial protein expression of tumor necrosis factor alpha (TNF-α), phosphorylated nuclear factor-κB (p-NFκB), troponin T, and B-cell lymphoma 2 (Bcl-2) was significantly lower, and the total NFκB/p-NFκB ratio and TLR-4 higher in doxorubicin-treated rats. Myocardial expression of OPA-1, MFN-2, DRP-1, and topoisomerase 2ß did not differ between groups (p > 0.05). In conclusion, doxorubicin-induced cardiotoxicity is accompanied by decreased Bcl-2 and phosphorylated NFκB and increased catalase activity and TLR-4 expression. Liraglutide failed to improve acute doxorubicin-induced cardiotoxicity in rats.
Assuntos
Cardiotoxicidade , Doxorrubicina , Liraglutida , Ratos Wistar , Animais , Liraglutida/farmacologia , Liraglutida/uso terapêutico , Doxorrubicina/efeitos adversos , Cardiotoxicidade/etiologia , Cardiotoxicidade/metabolismo , Masculino , Ratos , Estresse Oxidativo/efeitos dos fármacos , Miocárdio/metabolismo , Miocárdio/patologia , NF-kappa B/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Coração/efeitos dos fármacosRESUMO
Twenty-five years ago, the underlying genetic cause for one of the most common and devastating inherited diseases in humans, spinal muscular atrophy (SMA), was identified. Homozygous deletions or, rarely, subtle mutations of SMN1 cause SMA, and the copy number of the nearly identical copy gene SMN2 inversely correlates with disease severity. SMA has become a paradigm and a prime example of a monogenic neurological disorder that can be efficiently ameliorated or nearly cured by novel therapeutic strategies, such as antisense oligonucleotide or gene replacement therapy. These therapies enable infants to survive who might otherwise have died before the age of two and allow individuals who have never been able to sit or walk to do both. The major milestones on the road to these therapies were to understand the genetic cause and splice regulation of SMN genes, the disease's phenotype-genotype variability, the function of the protein and the main affected cellular pathways and tissues, the disease's pathophysiology through research on animal models, the windows of opportunity for efficient treatment, and how and when to treat patients most effectively.This review aims to bridge our knowledge from phenotype to genotype to therapy, not only highlighting the significant advances so far but also speculating about the future of SMA screening and treatment.
Assuntos
Atrofia Muscular Espinal/genética , Atrofia Muscular Espinal/terapia , Oligonucleotídeos Antissenso/administração & dosagem , Animais , Genótipo , Humanos , Atrofia Muscular Espinal/patologia , FenótipoRESUMO
Distal hereditary motor neuropathies (HMNs) and axonal Charcot-Marie-Tooth neuropathy (CMT2) are clinically and genetically heterogeneous diseases characterized primarily by motor neuron degeneration and distal weakness. The genetic cause for about half of the individuals affected by HMN/CMT2 remains unknown. Here, we report the identification of pathogenic variants in GBF1 (Golgi brefeldin A-resistant guanine nucleotide exchange factor 1) in four unrelated families with individuals affected by sporadic or dominant HMN/CMT2. Genomic sequencing analyses in seven affected individuals uncovered four distinct heterozygous GBF1 variants, two of which occurred de novo. Other known HMN/CMT2-implicated genes were excluded. Affected individuals show HMN/CMT2 with slowly progressive distal muscle weakness and musculoskeletal deformities. Electrophysiological studies confirmed axonal damage with chronic neurogenic changes. Three individuals had additional distal sensory loss. GBF1 encodes a guanine-nucleotide exchange factor that facilitates the activation of members of the ARF (ADP-ribosylation factor) family of small GTPases. GBF1 is mainly involved in the formation of coatomer protein complex (COPI) vesicles, maintenance and function of the Golgi apparatus, and mitochondria migration and positioning. We demonstrate that GBF1 is present in mouse spinal cord and muscle tissues and is particularly abundant in neuropathologically relevant sites, such as the motor neuron and the growth cone. Consistent with the described role of GBF1 in Golgi function and maintenance, we observed marked increase in Golgi fragmentation in primary fibroblasts derived from all affected individuals in this study. Our results not only reinforce the existing link between Golgi fragmentation and neurodegeneration but also demonstrate that pathogenic variants in GBF1 are associated with HMN/CMT2.
Assuntos
Axônios/metabolismo , Doença de Charcot-Marie-Tooth/genética , Fatores de Troca do Nucleotídeo Guanina/genética , Debilidade Muscular/genética , Atrofia Muscular Espinal/genética , Anormalidades Musculoesqueléticas/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Sequência de Aminoácidos , Animais , Axônios/patologia , Vesículas Revestidas pelo Complexo de Proteína do Envoltório/metabolismo , Vesículas Revestidas pelo Complexo de Proteína do Envoltório/patologia , Doença de Charcot-Marie-Tooth/diagnóstico , Doença de Charcot-Marie-Tooth/metabolismo , Doença de Charcot-Marie-Tooth/patologia , Feminino , Fibroblastos/metabolismo , Fibroblastos/patologia , Expressão Gênica , Complexo de Golgi/metabolismo , Complexo de Golgi/patologia , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Heterozigoto , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Neurônios Motores/metabolismo , Neurônios Motores/patologia , Debilidade Muscular/diagnóstico , Debilidade Muscular/metabolismo , Debilidade Muscular/patologia , Atrofia Muscular Espinal/diagnóstico , Atrofia Muscular Espinal/metabolismo , Atrofia Muscular Espinal/patologia , Anormalidades Musculoesqueléticas/diagnóstico , Anormalidades Musculoesqueléticas/metabolismo , Anormalidades Musculoesqueléticas/patologia , Mutação , Linhagem , Cultura Primária de Células , Medula Espinal/anormalidades , Medula Espinal/metabolismoRESUMO
OBJECTIVE: Rehabilitation top-down techniques based on brain stimulation present variable outcomes in unilateral spatial neglect (USN) after stroke. This study aimed to examine the effects of physical therapy after anodal and cathodal transcranial direct current stimulation (A-tDCS and C-tDCS, respectively) to improve visuospatial and functional impairments in individuals with USN after stroke. METHODS: This double-blinded, pilot randomized clinical trial enrolled patients with USN after ischemic stroke. Randomization was stratified according to the Behavior Inattention Test-Conventional (BIT-C) and Catherine Bergego Scale (CBS). Outpatient physical therapy was conducted for 7.5 weeks after 20 minutes of tDCS. The primary outcome was the USN degree evaluated by the BIT-C. Secondary outcomes were the difference in CBS score, stroke severity (National Institutes of Health Stroke Scale [NIHSS]), disability (modified Rankin Scale), autonomy (Barthel Index, Functional Independence Measure), and quality of life (EuroQol Group 5-Dimension Self-Report Questionnaire). Outcomes were analyzed using an analysis of covariance model corrected by age, baseline NIHSS, and baseline BIT-C. Pairwise post hoc comparisons were performed using Bonferroni correction. RESULTS: In the primary outcomes, A-tDCS led to greater improvement in BIT-C after intervention (mean difference [MD] = 18.4, 95% confidence interval [CI] = 3.9-32.8, p = 0.008) compared to sham. However, no significant differences were observed between A-tDCS and C-tDCS (MD = 13.9, 95% CI = -0.3 to 28.1, p = 0.057), or C-tDCS and sham (MD = 4.5, 95% CI = -9.7 to 18.8, p = 0.99). There were no significant differences between groups in terms of secondary outcomes. INTERPRETATION: A-tDCS associated with physical therapy can decrease the severity of USN after stroke. However, these preliminary findings must be confirmed by collecting additional evidence in a larger phase 3 trial. ANN NEUROL 2022;92:400-410.
Assuntos
Transtornos da Percepção , Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral , Estimulação Transcraniana por Corrente Contínua , Encéfalo , Humanos , Transtornos da Percepção/etiologia , Transtornos da Percepção/terapia , Qualidade de Vida , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/terapia , Estimulação Transcraniana por Corrente Contínua/métodos , Resultado do TratamentoRESUMO
OBJECTIVE: Some studies have pointed to gabapentinoids as promising medications in postoperative pain control. The objective of the present study was to evaluate the efficacy of pregabalin in reducing postoperative pain in tonsillectomy and lateral pharyngoplasties. STUDY DESIGN: Double-blind randomized controlled trial. SETTING: Tertiary care center. METHODS: A double-blind randomized controlled trial was conducted with patients undergoing tonsillectomies and lateral pharyngoplasties between Aug 29, 2017, and Oct 31, 2020. Data of interest such as opioid consumption, pain scores, and adverse outcomes such as dizziness, nausea, headache, and sedation within 7 days following surgeries were analyzed. RESULTS: No statistically significant difference was observed in pain scores and opioid consumption between the groups studied in the pilot project. The use of pregabalin was associated with lower incidence of dizziness compared to controls. CONCLUSION: Gabapentinoids, especially pregabalin, are drugs whose potential for controlling pain after pharyngeal surgery, such as tonsillectomy and sleep apnea surgery, still needs to be more fully evaluated. After the conclusion of the present study, we hope to answer this question about the role of pregabalin in oropharyngeal surgeries.
Assuntos
Analgésicos , Tonsilectomia , Humanos , Pregabalina/uso terapêutico , Projetos Piloto , Analgésicos/uso terapêutico , Tonsilectomia/efeitos adversos , Analgésicos Opioides/uso terapêutico , Tontura/induzido quimicamente , Tontura/tratamento farmacológico , Dor Pós-Operatória/tratamento farmacológico , Dor Pós-Operatória/etiologiaRESUMO
Strain Az39T of Azospirillum is a diazotrophic plant growth-promoting bacterium isolated in 1982 from the roots of wheat plants growing in Marcos Juárez, Córdoba, Argentina. It produces indole-3-acetic acid in the presence of l-tryptophan as a precursor, grows at 20-38 °C (optimal 38 °C), and the cells are curved or spiral-shaped, with diameters ranging from 0.5-0.9 to 1.8-2.2 µm. They contain C16â:â0, C18â:â0 and C18â:â1 ω7c/ω6c as the main fatty acids. Phylogenetic analysis of its 16S rRNA gene sequence confirmed that this strain belongs to the genus Azospirillum, showing a close relationship with Azospirillum baldaniorum Sp245T, Azospirillum brasilense Sp7T and Azospirillum formosense CC-Nfb-7T. Housekeeping gene analysis revealed that Az39T, together with five strains of the genus (Az19, REC3, BR 11975, MTCC4035 and MTCC4036), form a cluster apart from A. baldaniorum Sp245T, A. brasilense Sp7T and A. formosense CC-Nfb-7T. Average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) between Az39T and the aforementioned type strains revealed values below 96â%, the circumscription limit for the species delineation (ANI: 95.3, 94.1 and 94.0â%; dDDH: 62.9, 56.3 and 55.6â%). Furthermore, a phylogeny evaluation of the core proteome, including 809 common shared proteins, showed an independent grouping of Az39T, Az19, REC3, BR 11975, MTCC4035 and MTCC4036. The G+C content in the genomic DNA of these six strains varied from 68.3 to 68.5â%. Based on the combined phylogenetic, genomic and phenotypic characterization presented here, we consider that strain Az39T, along with strains Az19, REC3, BR 11975, MTCC4035 and MTCC4036, are members of a new Azospirillum species, for which the name Azospirillum argentinense sp. nov. is proposed. The type strain is Az39T (=LBPCV39T=BR 148428T=CCCT 22.01T).
Assuntos
Azospirillum brasilense , Azospirillum brasilense/genética , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Fosfolipídeos/análise , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona/análiseRESUMO
BACKGROUND: Over a third of the world's population is at risk of Plasmodium vivax-induced malaria. The unique aspect of the parasite's biology and interactions with the human host make it harder to control and eliminate the disease. Glucose-6-phosphate dehydrogenase (G6PD) deficiency and Duffy-negative blood groups are two red blood cell (RBC) variations that can confer protection against malaria. METHODS: Molecular genotyping of G6PD and Duffy variants was performed in 225 unrelated patients (97 with uncomplicated and 128 with severe vivax malaria) recruited at a Reference Centre for Infectious Diseases in Manaus. G6PD and Duffy variants characterizations were performed using Real Time PCR (qPCR) and PCR-RFLP, respectively. RESULTS: The Duffy blood group system showed a phenotypic distribution Fy(a + b-) of 70 (31.1%), Fy(a + b +) 96 (42.7%), Fy(a-b +) 56 (24.9%) and Fy(a-b-) 1 (0.44%.) The genotype FY*A/FY*B was predominant in both uncomplicated (45.3%) and severe malaria (39.2%). Only one Duffy phenotype Fy(a-b) was found and this involved uncomplicated vivax malaria. The G6PD c.202G > A variant was found in 11 (4.88%) females and 18 (8.0%) males, while c.376A > G was found in 20 females (8.88%) and 23 (10.22%) male patients. When combined GATA mutated and c.202G > A and c.376A > G mutated, was observed at a lower frequency in uncomplicated (3.7%) in comparison to severe malaria (37.9%). The phenotype Fy(a-b +) (p = 0.022) with FY*B/FY*B (p = 0.015) genotype correlated with higher parasitaemia. CONCLUSIONS: A high prevalence of G6PD c202G > A and c.376A > G and Duffy variants is observed in Manaus, an endemic area for vivax malaria. In addition, this study reports for the first time the Duffy null phenotype Fy(a-b-) in the population of the Amazonas state. Moreover, it is understood that the relationship between G6PD and Duffy variants can modify clinical symptoms in malaria caused by P. vivax and this deserves to be further investigated and explored among this population.
Assuntos
Deficiência de Glucosefosfato Desidrogenase , Malária Vivax , Brasil/epidemiologia , Sistema do Grupo Sanguíneo Duffy/genética , Feminino , Genótipo , Deficiência de Glucosefosfato Desidrogenase/genética , Humanos , Malária Vivax/epidemiologia , Masculino , Plasmodium vivax/genéticaRESUMO
Melanoma is the most aggressive type of skin cancer, and thus it is important to develop new drugs for its treatment. The present study aimed to examine the antitumor effects of solamargine a major alkaloid heteroside present in Solanum lycocarpum fruit. In addition solamargine was incorporated into nanoparticles (NP) of yttrium vanadate functionalized with 3-chloropropyltrimethoxysilane (YVO4:Eu3+:CPTES:SM) to determine antitumor activity. The anti-melanoma assessment was performed using a syngeneic mouse melanoma model B16F10 cell line. In addition, systemic toxicity, nephrotoxic, and genotoxic parameters were assessed. Solamargine, at doses of 5 or 10 mg/kg/day administered subcutaneously to male C57BL/6 mice for 5 days, decreased tumor size and frequency of mitoses in tumor tissue, indicative of a decrease in cell proliferation. Treatments with YVO4:Eu3+:CPTES:SM significantly reduced the number of mitoses in tumor tissue, associated with no change in tumor size. There were no apparent signs of systemic toxicity, nephrotoxicity, and genotoxicity initiated by treatments either with solamargine alone or plant alkaloid incorporated into NP. The animals treated with YVO4:Eu3+:CPTES:SM exhibited significant increase in spleen weight accompanied by no apparent histological changes in all tissues examined. In addition, animals treated with solamargine (10 mg/kg/day) and YVO4:Eu3+:CPTES:SM demonstrated significant reduction in hepatic DNA damage which was induced by tumor growth. Therefore, data suggest that solamargine may be considered a promising candidate in cancer therapy with no apparent toxic effects.
Assuntos
Antineoplásicos/farmacologia , Melanoma Experimental/tratamento farmacológico , Alcaloides de Solanáceas/farmacologia , Animais , Antineoplásicos/toxicidade , Linhagem Celular Tumoral , Dano ao DNA , Fígado/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mitose/efeitos dos fármacos , Nanopartículas/administração & dosagem , Silanos/química , Alcaloides de Solanáceas/toxicidade , Ítrio/químicaRESUMO
BACKGROUND: Sickle cell anemia (SCA) is the leading cause of childhood stroke. We aimed to evaluate whether altered cerebral flow velocities, as measured by transcranial Doppler (TCD), are associated with vaso-occlusive complications in addition to stroke in pediatric SCA patients. METHODS: We evaluated 37 children aged between 2 and 16 years with SCA who underwent screening for TCD between January 2012 and October 2018. Genotypic profiles and demographic data were collected, TCD examinations were performed during follow-up, and the presence of sickling crises was compared. Survival analyses were performed using simple frailty models, in which each predictor variable was analyzed separately in relation to the occurrence of a sickling crisis. RESULTS: The variables related to sickle cell crises in the univariate analysis were peak systolic velocity (PSV) in the middle cerebral artery (MCA), hazard ratio (HR) 1.01 (1.00-1.02) p = 0.04; end-diastolic velocity (EDV) in the MCA, HR 1.02 (1.01-1.04) p = 0.01; time average mean maximum velocity (TAMMV) in the basilar artery (BA), HR 1.02 (1.00-1.04) p = 0.04; hemoglobin, HR 0.49 (0.38-0.65) p < 0.001; hematocrit, HR 0.78 (0.71-0.85) p < 0.001; leukocyte counts, HR 1.1 (1.05-1.15) p < 0.001; platelets counts, HR 0.997 (0.994-0.999) p = 0.02; and reticulocyte numbers, HR 1.14 (1.06-1.23) p < 0.001. CONCLUSIONS: Our results indicate PSV and EDV in the MCA and TAMMV in the BA as markers of risk for the occurrence of sickling crises in SCA.
Assuntos
Anemia Falciforme , Acidente Vascular Cerebral , Adolescente , Anemia Falciforme/complicações , Anemia Falciforme/diagnóstico por imagem , Velocidade do Fluxo Sanguíneo , Circulação Cerebrovascular , Criança , Pré-Escolar , Estudos de Coortes , Humanos , América Latina , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/etiologiaRESUMO
Recent work with prion diseases and synucleinopathies indicates that accurate diagnostic methods for protein-folding diseases can be based on the ultrasensitive, amplified measurement of pathological aggregates in biospecimens. A better understanding of the physicochemical factors that control the seeded polymerization of such aggregates, and their amplification in vitro, should allow improvements in existing assay platforms, as well as the development of new assays for other proteopathic aggregates. Here, we systematically investigated the effects of the ionic environment on the polymerization of tau, α-synuclein, and the prion protein (PrP) induced by aggregates in biospecimens. We screened salts of the Hofmeister series, a relative ordering of strongly and weakly hydrated salts that tend to precipitate or solubilize proteins. We found that sensitivities of tau-based assays for Alzheimer's seeds and PrP-based assays for prions were best in weakly hydrated anions. In contrast, we saw an inverse trend with different tau-based assays, improving detection sensitivity for progressive supranuclear palsy seeds by ≈106 Hofmeister analysis also improved detection of sporadic Creutzfeldt-Jakob disease prions in human nasal brushings and chronic wasting disease prions in deer-ear homogenates. Our results demonstrate strong and divergent influences of ionic environments on the amplification and detection of proteopathic seeds as biomarkers for protein-folding diseases.
Assuntos
Doença de Alzheimer/metabolismo , Síndrome de Creutzfeldt-Jakob/metabolismo , Doenças Priônicas/metabolismo , Proteínas Priônicas/química , alfa-Sinucleína/química , Proteínas tau/química , Doença de Alzheimer/diagnóstico , Ânions/química , Biomarcadores/química , Biomarcadores/metabolismo , Síndrome de Creutzfeldt-Jakob/diagnóstico , Técnicas e Procedimentos Diagnósticos , Humanos , Cinética , Polimerização , Doenças Priônicas/diagnóstico , Proteínas Priônicas/metabolismo , Agregados Proteicos , alfa-Sinucleína/metabolismo , Proteínas tau/metabolismoRESUMO
Hyaluronic acid (HA) is a Glycosaminoglycan made of disaccharide units containing N-acetyl-D-glucosamine and glucuronic acid. Its molecular mass can reach 10 MDa and its physiological properties depend on its polymeric property, polyelectrolyte feature and viscous nature. HA is a ubiquitous compound found in almost all biological tissues and fluids. So far, HA grades are produced by biotechnology processes, while in the human organism it is a major component of the extracellular matrix (ECM) in brain tissue, synovial fluid, vitreous humor, cartilage and skin. Indeed, HA is capable of forming hydrogels, polymer crosslinked networks that are very hygroscopic. Based on these considerations, we propose an overview of HA-based scaffolds developed for brain cancer treatment, central and peripheral nervous systems, discuss their relevance and identify the most successful developed systems.
Assuntos
Acetilglucosamina , Ácido Hialurônico , Humanos , Polieletrólitos , Hidrogéis , Glicosaminoglicanos , Ácido Glucurônico , Dissacarídeos , Sistema Nervoso , Alicerces Teciduais , Engenharia TecidualRESUMO
OBJECTIVES: We aimed to evaluate the predictive performance of the PRISMA-7 frailty criteria regarding the composite outcome of disability or death in patients with an acute ischemic stroke, and to compare it with the Frailty Index and the National Institutes of Health Stroke Scale (NIHSS). MATERIALS AND METHODS: This prospective cohort study involved all patients aged ≥ 40 years admitted with an acute ischemic stroke between March 2019 and January 2020. We performed survival analyses, calculated risk ratios, sensitivity, specificity, and predictive values for the combined outcome of disability or death according to the presence of frailty as determined by the PRISMA-7 and the Frailty Index, and stroke severity based on the NIHSS. RESULTS: In 174 patients with acute ischemic stroke, being frail in the week before the stroke according to the PRISMA-7 was associated with a Risk Ratio of 4·50 (95%CI 1·77-11·43, P <0·001) and a Positive Predictive Value of 89% (95%CI 77-99%) for being disabled or dead 90 days after the stroke, and a Hazard Ratio of 3·33 (95%CI 1·48-7·51, P = 0·004) for the survival outcome. The predictive performance of the PRISMA-7 was not significantly different from the Frailty Index or the NIHSS. CONCLUSIONS: We provide evidence that the PRISMA-7 frailty criteria may be a useful prognostication tool in acute ischemic stroke.
Assuntos
Isquemia Encefálica , Fragilidade , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Fragilidade/diagnóstico , Isquemia Encefálica/diagnóstico , Isquemia Encefálica/terapia , Estudos Prospectivos , Prognóstico , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/terapiaRESUMO
Zidovudine (AZT) has been widely used alone or in combination with other antiretroviral drugs for the treatment of human immunodeficiency virus. Its erratic oral bioavailability necessitates frequent administration of high doses, resulting in severe side effects. In this study, the design of mucoadhesive solid dispersions (SDs) based on chitosan (CS) and hypromellose phthalate (HP) was rationalized as a potential approach to modulate AZT physicochemical and pharmaceutical properties. SDs were prepared at different drug:polymer ratios, using an eco-friendly technique, which avoids the use of organic solvents. Particles with diameter from 56 to 73 µm and negative zeta potentials (-27 to -32 mV) were successfully prepared, achieving high drug content. Infrared spectroscopy revealed interactions between polymers but no interactions between the polymers and AZT. Calorimetry and X-ray diffraction analyses showed that AZT was amorphized into the SDs. The mucoadhesive properties of SDs were evidenced, and the control of AZT release rates from the matrix was achieved, mainly in acid media. The simple, low-cost, and scalable technology proposed for production of SDs as a carrier platform for AZT is an innovative approach, and it proved to be a feasible strategy for modulation the physico-chemical, mucoadhesive, and release properties of the drug.
Assuntos
Quitosana , Quitosana/química , Portadores de Fármacos/química , Humanos , Derivados da Hipromelose , Metilcelulose/análogos & derivados , Polímeros/química , Solubilidade , Zidovudina/químicaRESUMO
Conventional dendritic cells (cDCs) are specialized in antigen presentation. In the mouse spleen, cDCs are classified in cDC1s and cDC2s, and express DEC205 and DCIR2 endocytic receptors, respectively. Monoclonal antibodies (mAbs) αDEC205 (αDEC) and αDCIR2 have been fused to different antigens to deliver them to cDC1s or cDC2s. We immunized mice with αDEC and αDCIR2 fused to an antigen using Poly(I:C) as adjuvant. The initial immune response was analyzed from days 3 to 6 after the immunization. We also studied the influence of a booster dose. Our results showed that antigen targeting to cDC1s promoted a pro-inflammatory TH 1 cell response. Antigen targeting to cDC2s induced TFH cells, GCs, and plasma cell differentiation. After boost, antigen targeting to cDC1s improved the TH 1 cell response and induced TH 1-like TFH cells that led to an increase in specific antibody titers and IgG class switch. Additionally, a population of regulatory T cells was also observed. Antigen targeting to cDC2s did not improve the specific antibody response after boost. Our results add new information on the immune response induced after the administration of a booster dose with αDEC and αDCIR2 fusion mAbs. These results may be useful for vaccine design using recombinant mAbs.
Assuntos
Células Dendríticas/imunologia , Receptores de Superfície Celular/imunologia , Células T Auxiliares Foliculares/imunologia , Linfócitos T Reguladores/imunologia , Células Th1/imunologia , Animais , Anticorpos Monoclonais/imunologia , Formação de Anticorpos/imunologia , Apresentação de Antígeno/imunologia , Feminino , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Poli I-C/imunologiaRESUMO
Phytochemicals have been suggested as an effective strategy for cancer prevention. Within this context, triterpene betulinic acid (BA) exhibits several biological properties but its chemopreventive effect has not been fully demonstrated. The present study investigated the antigenotoxic potential of BA against doxorubicin (DXR)-induced genotoxicity using the mouse peripheral blood micronucleus assay, as well as its anticarcinogenic activity against 1,2dimethylhydrazine (DMH)-induced colorectal lesions in rats. Micronuclei (MN) assay and aberrant crypt foci assay were used to assess the antigenotoxic and the anticarcinogenic potential, respectively. The molecular mechanisms underlying the anticarcinogenic activity of BA were evaluated by assessing anti-inflammatory (COX-2) and antiproliferative (PCNA) pathways. The results demonstrated that BA at the dose of 0.5 mg/kg bodyweight exerted antigenotoxic effects against DXR, with a reduction of 70.2% in the frequencies of chromosomal damage. Animals treated with BA showed a 64% reduction in the number of preneoplastic lesions when compared to those treated with the carcinogen alone. The levels of COX-2 and PCNA expression in the colon were significantly lower in animals treated with BA and DMH compared to those treated with the carcinogen alone. The chemopreventive effect of BA is related, at least in part, to its antiproliferative and anti-inflammatory activity, indicating a promising potential of this triterpene in anticancer therapies, especially for colorectal cancer.
Assuntos
Anticarcinógenos/farmacologia , Antimutagênicos/farmacologia , Inibidores de Ciclo-Oxigenase 2/farmacologia , Ciclo-Oxigenase 2/efeitos dos fármacos , Triterpenos Pentacíclicos/farmacologia , Antígeno Nuclear de Célula em Proliferação/efeitos dos fármacos , Animais , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/induzido quimicamente , Neoplasias Colorretais/prevenção & controle , Ciclo-Oxigenase 2/metabolismo , Doxorrubicina/toxicidade , Inflamação/prevenção & controle , Masculino , Camundongos , Lesões Pré-Cancerosas/induzido quimicamente , Lesões Pré-Cancerosas/prevenção & controle , Transdução de Sinais/efeitos dos fármacos , Ácido BetulínicoRESUMO
PURPOSE: To assess the outcomes of vitrectomy with or without cataract surgery for the treatment of idiopathic ERM in phakic eyes and evaluate predictors of functional and anatomical outcomes. METHODS: Retrospective cohort of consecutive phakic ERM eyes distributed in three groups: a) combined (phacovitrectomy) group, b) PPV-only group, and c) consecutive group (PPV followed by cataract surgery). Main outcomes were final visual acuity (VA) and cystoid macular edema (CME) occurrence. Potential predictors of VA or CME included clinical variables and SD-OCT parameters. RESULTS: A total of 108 eyes were included in this study. There were no differences in the final VA between consecutive and combined groups (0.22 vs 0.10 logMAR, p = 0.851). Twelve eyes from the combined group (23%) and one eye from the PPV-only group presented CME (p = 0.001). There were no differences between postoperative CME occurrence in combined versus consecutive group (12 vs 7, p = 0.38). The presence of cotton-ball sign predicted the development of CME [OR 2.86 (95%CI 1.01-8.18), p = 0.049] while separated ERM-ILM complex was found to be protective [OR 0.25 (95%CI 0.08-0.77), p = 0.015]. CONCLUSIONS: Functional and anatomical results of PPV with ERM and ILM peeling combined with cataract surgery was equivalent to the consecutive procedure, with both strategies being effective. Separated ERM-ILM complex has prognostic value in these patients, as its presence at baseline was found to be protective for postoperative CME.