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1.
Mol Pharmacol ; 105(3): 194-201, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38253398

RESUMO

Intracellular Ca2+ leak from cardiac ryanodine receptor (RyR2) is an established mechanism of sudden cardiac death (SCD), whereby dysregulated Ca2+ handling causes ventricular arrhythmias. We previously discovered the RyR2-selective inhibitor ent-(+)-verticilide (ent-1), a 24-membered cyclooligomeric depsipeptide that is the enantiomeric form of a natural product (nat-(-)-verticilide). Here, we examined its 18-membered ring-size oligomer (ent-verticilide B1; "ent-B1") in RyR2 single channel and [3H]ryanodine binding assays, and in Casq2 -/- cardiomyocytes and mice, a gene-targeted model of SCD. ent-B1 inhibited RyR2 single channels and RyR2-mediated spontaneous Ca2+ release in Casq2 -/- cardiomyocytes with sub-micromolar potency. ent-B1 was a partial RyR2 inhibitor, with maximal inhibitory efficacy of less than 50%. ent-B1 was stable in plasma, with a peak plasma concentration of 1460 ng/ml at 10 minutes and half-life of 45 minutes after intraperitoneal administration of 3 mg/kg in mice. In vivo, ent-B1 significantly reduced catecholamine-induced ventricular arrhythmias in Casq2 -/- mice in a dose-dependent manner. Hence, we have identified a novel chemical entity - ent-B1 - that preserves the mechanism of action of a hit compound and shows therapeutic efficacy. These findings strengthen RyR2 as an antiarrhythmic drug target and highlight the potential of investigating the mirror-image isomers of natural products to discover new therapeutics. SIGNIFICANCE STATEMENT: The cardiac ryanodine receptor (RyR2) is an untapped target in the stagnant field of antiarrhythmic drug development. We have confirmed RyR2 as an antiarrhythmic target in a mouse model of sudden cardiac death and shown the therapeutic efficacy of a second enantiomeric natural product.


Assuntos
Produtos Biológicos , Depsipeptídeos , Camundongos , Animais , Antiarrítmicos/farmacologia , Antiarrítmicos/uso terapêutico , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Arritmias Cardíacas/tratamento farmacológico , Arritmias Cardíacas/metabolismo , Depsipeptídeos/metabolismo , Depsipeptídeos/uso terapêutico , Morte Súbita Cardíaca/etiologia , Miócitos Cardíacos/metabolismo , Cálcio/metabolismo
2.
J Pharmacol Exp Ther ; 385(3): 205-213, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36894328

RESUMO

The unnatural verticilide enantiomer (ent-verticilide) is a selective and potent inhibitor of cardiac ryanodine receptor (RyR2) calcium release channels and exhibits antiarrhythmic activity in a murine model of catecholaminergic polymorphic ventricular tachycardia (CPVT). To determine verticilide's pharmacokinetic and pharmacodynamic properties in vivo, we developed a bioassay to measure nat- and ent-verticilide in murine plasma and correlated plasma concentrations with antiarrhythmic efficacy in a mouse model of CPVT. nat-Verticilide rapidly degraded in plasma in vitro, showing >95% degradation within 5 minutes, whereas ent-verticilide showed <1% degradation over 6 hours. Plasma was collected from mice following intraperitoneal administration of ent-verticilide at two doses (3 mg/kg, 30 mg/kg). Peak C max and area under the plasma-concentration time curve (AUC) scaled proportionally to dose, and the half-life was 6.9 hours for the 3-mg/kg dose and 6.4 hours for the 30-mg/kg dose. Antiarrhythmic efficacy was examined using a catecholamine challenge protocol at time points ranging from 5 to 1440 minutes after intraperitoneal dosing. ent-Verticilide inhibited ventricular arrhythmias as early as 7 minutes after administration in a concentration-dependent manner, with an estimated potency (IC50) of 266 ng/ml (312 nM) and an estimated maximum inhibitory effect of 93.5%. Unlike the US Food and Drug Administration-approved pan-RyR blocker dantrolene, the RyR2-selective blocker ent-verticilide (30 mg/kg) did not reduce skeletal muscle strength in vivo. We conclude that ent-verticilide has favorable pharmacokinetic properties and reduces ventricular arrhythmias with an estimated potency in the nanomolar range, warranting further drug development. SIGNIFICANCE STATEMENT: ent-Verticilide has therapeutic potential to treat cardiac arrhythmias, but little is known about its pharmacological profile in vivo. The primary purpose of this study is to determine the systemic exposure and pharmacokinetics of ent-verticilide in mice and estimate its efficacy and potency in vivo. The current work suggests ent-verticilide has favorable pharmacokinetic properties and reduces ventricular arrhythmias with an estimated potency in the nanomolar range, warranting further drug development.


Assuntos
Canal de Liberação de Cálcio do Receptor de Rianodina , Taquicardia Ventricular , Camundongos , Animais , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Antiarrítmicos/farmacologia , Antiarrítmicos/uso terapêutico , Arritmias Cardíacas/tratamento farmacológico , Taquicardia Ventricular/tratamento farmacológico , Taquicardia Ventricular/metabolismo , Miócitos Cardíacos/metabolismo
3.
J Nat Prod ; 82(7): 1831-1838, 2019 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-31313922

RESUMO

Salinaphthoquinones A-E (1-5) were isolated from a marine Salininispora arenicola strain, recovered from sediments of the St. Peter and St. Paul Archipelago, Brazil. The structures of the compounds were elucidated using a combination of spectroscopic (NMR, IR, HRESIMS) data, including single-crystal X-ray diffraction analysis. A plausible biosynthetic pathway for 1-5 is proposed. Compounds 1 to 4 displayed moderate activity against Staphylococcus aureus and Enterococcus faecalis with MIC values of 125 to 16 µg/mL.


Assuntos
Antibacterianos/farmacologia , Sedimentos Geológicos/química , Micromonosporaceae/química , Naftoquinonas/farmacologia , Água do Mar/química , Antibacterianos/química , Brasil , Sedimentos Geológicos/microbiologia , Estrutura Molecular , Naftoquinonas/química , Água do Mar/microbiologia
4.
J Thromb Thrombolysis ; 38(3): 372-9, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24510678

RESUMO

In platelets, thrombin receptor signaling depends upon the release of adenosine diphosphate and subsequent activation at purinergic subtype Y (P2Y) receptors. The purpose of this study is to evaluate the influence of specific P2Y12 polymorphisms on platelet reactivity in healthy subjects mediated by thrombin receptor activating peptide (TRAP). We recruited a total of 29 healthy volunteers who had been previously genotyped for two polymorphisms of the P2Y12 receptor: the H2 haplotype (rs2046934) and 34C>T (rs6785930). Flow cytometry and the VerifyNow assay were used to assess platelet activation and aggregation stimulated by TRAP in the presence and absence of specific receptor antagonists for the P2Y1, P2Y12, and thromboxane A2 receptors. We identified a significant recessive effect of the P2Y12-receptor H2 haplotype on TRAP-induced flow cytometry. Specifically, H2/H2 carriers (n = 5) demonstrated a significant reduction in both glycoprotein IIb/IIIa receptor activation (p < 0.001) and CD62P expression (p = 0.035). While the VerifyNow assay did not reveal any effect of haplotype on TRAP-mediated platelet aggregation (p = 0.72), the H2/H2 subjects demonstrated greater platelet inhibition in the presence of cangrelor, a specific receptor antagonist for the P2Y12 receptor (p = 0.023). No consistent effects of the separate 34C>T genotype (rs6785930) were demonstrated under the conditions evaluated. The findings of this study suggest a potential association between P2Y12-receptor H2/H2 carriers and reduced platelet function mediated by TRAP in healthy volunteers.


Assuntos
Haplótipos , Fragmentos de Peptídeos/farmacologia , Agregação Plaquetária , Polimorfismo Genético , Receptores Purinérgicos P2Y12 , Monofosfato de Adenosina/análogos & derivados , Monofosfato de Adenosina/farmacologia , Adulto , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/genética , Humanos , Masculino , Selectina-P/biossíntese , Agregação Plaquetária/efeitos dos fármacos , Agregação Plaquetária/genética , Antagonistas do Receptor Purinérgico P2Y/farmacologia , Receptores Purinérgicos P2Y12/genética , Receptores Purinérgicos P2Y12/metabolismo
5.
Nano Lett ; 13(9): 4517-21, 2013 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-23952071

RESUMO

Topological insulators such as Bi2Se3 and Bi2Te3 have extremely promising transport properties, due to their unique electronic behavior: they are insulators in the bulk and conducting at the surface. Recently, the coexistence of two types of surface conducting channels has been observed for Bi2Se3, one being Dirac electrons from the topological state and the other electrons from a conventional two-dimensional gas. As an explanation for this effect, a possible structural modification of the surface of these materials has been hypothesized. Using scanning tunneling microscopy we have directly observed the coexistence of a conducting bilayer and the bare surface of bulk-terminated Bi2Te3. X-ray crystal truncation rod scattering was used to directly show the stabilization of this epitaxial bilayer which is primarily composed of bismuth. Using this information, we have performed density functional theory calculations to determine the electronic properties of the possible surface terminations. They can be used to understand recent angular resolved photoemission data which have revealed this dual surface electronic behavior.

6.
Malays Orthop J ; 18(1): 133-139, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38638657

RESUMO

Introduction: This study aimed to find the association between the Knee Movement or KM method versus the traditional lateral knee radiograph positioning procedure and the incidence of true lateral knee radiographs achieved. Materials and methods: A cross-sectional study of patients with knee problems that underwent lateral knee radiograph using the knee movement method (KM method), starting from March 2022 until August 2022. Fifty knee radiograph results using the KM method (KM group) were compared to retrospective data from fifty knee radiograph from the patients before March 2022 using the traditional method of lateral knee radiograph as the control (TM group). The data were analysed using the Chi-Square test to see if the KM method is associated with more true lateral knee radiograph results achieved compared to the traditional procedure. Results: Fifty patients in the KM method group had 80% (n=40) true lateral knee radiographs and 20% (n=10) untrue lateral knee radiographs, while in the Traditional Procedure group from the retrospective data of 50 patients had 44% (n=22) true lateral knee radiographs and 56% (n=28) untrue lateral knee radiographs (P<0.05). There is no significant association between the type of procedure applied with the types of error (P=0.432). Nevertheless, it helps us as it gives a gross picture that most of the errors are under-rotation of the knee, either from the KM method Group 90% (n=9) or the Traditional procedure Group 79% (n=22). Conclusion: The KM method was associated with achievement of a more true and accurate lateral knee radiograph. Additional studies with a larger sample should be done to evaluate the reliability of this method.

7.
bioRxiv ; 2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37461611

RESUMO

Ca 2+ leak from cardiac ryanodine receptor (RyR2) is an established mechanism of sudden cardiac death (SCD), whereby dysregulated Ca 2+ handling causes ventricular arrhythmias. We previously discovered the RyR2-selective inhibitor ent- (+)-verticilide ( ent -1), a 24-membered cyclooligomeric depsipeptide that is the enantiomeric form of a natural product ( nat -(-)-verticilide). Here, we examined its 18-membered ring-size oligomer ( ent -verticilide B1; " ent -B1") in single RyR2 channel assays, [ 3 H]ryanodine binding assays, and in Casq2 -/- cardiomyocytes and mice, a gene-targeted model of SCD. ent -B1 inhibited RyR2 single-channels and [ 3 H]ryanodine binding with low micromolar potency, and RyR2-mediated spontaneous Ca 2+ release in Casq2-/- cardiomyocytes with sub-micromolar potency. ent -B1 was a partial RyR2 inhibitor, with maximal inhibitory efficacy of less than 50%. ent -B1 was stable in plasma, with a peak plasma concentration of 1460 ng/ml at 10 min and half-life of 45 min after intraperitoneal administration of 3 mg/kg in mice. Both 3 mg/kg and 30 mg/kg ent -B1 significantly reduced catecholamine-induced ventricular arrhythmia in Casq2-/- mice. Hence, we have identified a novel chemical entity - ent -B1 - that preserves the mechanism of action of a hit compound and shows therapeutic efficacy. These findings strengthen RyR2 as an antiarrhythmic drug target and highlight the potential of investigating the mirror-image isomers of natural products to discover new therapeutics. Significance statement: The cardiac ryanodine receptor (RyR2) is an untapped target in the stagnant field of antiarrhythmic drug development. We have confirmed RyR2 as an antiarrhythmic target in a mouse model of sudden cardiac death and shown the therapeutic efficacy of a second enantiomeric natural product.

8.
Caries Res ; 46(3): 177-84, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22508493

RESUMO

Dental caries remains the most common chronic childhood disease. Despite strong evidence of genetic components, there have been few studies of candidate genes and caries. In this analysis we tried to assess genetic and environmental factors contributing to childhood caries in the Iowa Fluoride Study. Environmental factors (age, sex, race, tooth-brushing frequencies and water fluoride level) and three dental caries scores (d(2)fs-total, d(2)fs-pit/fissure, and d(2)fs-smooth surface) were assessed in 575 unrelated children (mean age 5.2 years). Regression analyses were applied to assess environmental correlates. The Family-Based Association Test was used to test genetic associations for 23 single nucleotide polymorphism (SNP) markers in 7 caries candidate genes on 333 Caucasian parent-child trios. We evaluated the associations between caries status and the level of both single and multiple SNPs (haplotype) respectively. Permutation procedure was performed for correction of inflated type I errors due to multiple testing. Age, tooth-brushing frequency and water fluoride level were significantly correlated to at least one carious score. Caries on pit and fissure surfaces was substantially higher than on smooth surfaces (61 vs. 39%). SNPs in three genes (DSPP, KLK4 and AQP5) showed consistent associations with protection against caries. Of note, KLK4 and AQP5 were also highlighted by subsequent haplotype analysis. Our results support the concept that genes can modify the susceptibility of caries in children. Replication analysis in independent cohorts is highly needed in order to verify the validity of our findings.


Assuntos
Aquaporina 5/genética , Suscetibilidade à Cárie Dentária/genética , Cárie Dentária/genética , Proteínas da Matriz Extracelular/genética , Calicreínas/genética , Fosfoproteínas/genética , Sialoglicoproteínas/genética , Dente Decíduo/patologia , Fatores Etários , Criança , Pré-Escolar , Índice CPO , Cárie Dentária/etiologia , Etnicidade , Feminino , Fluoretos/análise , Interação Gene-Ambiente , Estudos de Associação Genética , Humanos , Iowa , Masculino , Polimorfismo de Nucleotídeo Único , Análise de Regressão , Fatores Sexuais , Inquéritos e Questionários , Escovação Dentária/estatística & dados numéricos , Abastecimento de Água
9.
Caries Res ; 46(1): 38-46, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22286298

RESUMO

Carious lesions are distributed nonuniformly across tooth surfaces of the complete dentition, suggesting that the effects of risk factors may be surface-specific. Whether genes differentially affect caries risk across tooth surfaces is unknown. We investigated the role of genetics on two classes of tooth surfaces, pit and fissure surfaces (PFS) and smooth surfaces (SMS), in more than 2,600 subjects from 740 families. Participants were examined for surface-level evidence of dental caries, and caries scores for permanent and/or primary teeth were generated separately for PFS and SMS. Heritability estimates (h(2), i.e. the proportion of trait variation due to genes) of PFS and SMS caries scores were obtained using likelihood methods. The genetic correlations between PFS and SMS caries scores were calculated to assess the degree to which traits covary due to common genetic effects. Overall, the heritability of caries scores was similar for PFS (h(2) = 19-53%; p < 0.001) and SMS (h(2) = 17-42%; p < 0.001). Heritability of caries scores for both PFS and SMS in the primary dentition was greater than in the permanent dentition and total dentition. With one exception, the genetic correlation between PFS and SMS caries scores was not significantly different from 100%, indicating that (mostly) common genes are involved in the risk of caries for both surface types. Genetic correlation for the primary dentition dfs (decay + filled surfaces) was significantly less than 100% (p < 0.001), indicating that genetic factors may exert differential effects on caries risk in PFS versus SMS in the primary dentition.


Assuntos
Cárie Dentária/genética , Esmalte Dentário/patologia , Fissuras Dentárias/genética , Predisposição Genética para Doença/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Região dos Apalaches/epidemiologia , Criança , Pré-Escolar , Estudos de Coortes , Índice CPO , Cárie Dentária/epidemiologia , Cárie Dentária/patologia , Suscetibilidade à Cárie Dentária/genética , Fissuras Dentárias/epidemiologia , Restauração Dentária Permanente/estatística & dados numéricos , Feminino , Variação Genética/genética , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Modelos Genéticos , Fenótipo , Vigilância da População , Característica Quantitativa Herdável , Perda de Dente/epidemiologia , Dente Decíduo/patologia , Adulto Jovem
10.
J Allergy Clin Immunol Pract ; 10(5): 1238-1246, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34915226

RESUMO

BACKGROUND: There is limited knowledge regarding whether intravenous magnesium (IV-Mg) improves outcomes in children with acute asthma exacerbations. OBJECTIVE: To examine whether IV-Mg improves outcomes in children with moderate and severe exacerbations. METHODS: We performed a secondary analysis using data from a prospective observational cohort of children aged 5 to 17 years with moderate and severe exacerbations. Standardized treatment included systemic corticosteroid and inhaled albuterol, with consideration of IV-Mg (75 mg/kg) for patients with insufficient response after 20 minutes. Propensity score (PS) models were used to examine associations of IV-Mg treatment with change in the validated Acute Asthma Intensity Research Score, hospitalization rate, and time to spacing of inhaled albuterol of 4 hours or more among hospitalized participants. RESULTS: Among 301 children, median (interquartile range) age was 8.1 (6.4-10.2) years, 170 were Black (57%), 201 were male (67%), and 84 received IV-Mg (28%). In a PS covariate-adjusted multivariable linear regression model, IV-Mg treatment was associated with a 2-hour increase in the Acute Asthma Intensity Research Score (ß-coefficient = 0.98; 95% confidence interval [CI], 0.20-1.77), indicating increased exacerbation severity. Three additional PS-based models yielded similar results. Participants receiving IV-Mg had 5.8-fold (95% CI, 2.8-11.9) and 6.8-fold (95% CI, 3.6-12.9) greater odds of hospitalization in PS-based multivariable regression models. Among hospitalized participants, there was no difference in time to albuterol of every 4 hours or more in a PS covariate-adjusted Cox proportional hazards model (hazard ratio = 1.2; 95% CI, 0.8-1.8). CONCLUSIONS: Among children with moderate and severe exacerbations, IV-Mg is associated with increased exacerbation severity, increased risk for hospitalization, and no acceleration in exacerbation resolution among hospitalized participants.


Assuntos
Antiasmáticos , Asma , Doença Aguda , Albuterol/uso terapêutico , Antiasmáticos/uso terapêutico , Asma/induzido quimicamente , Asma/tratamento farmacológico , Criança , Quimioterapia Combinada , Feminino , Hospitalização , Humanos , Magnésio/uso terapêutico , Masculino
11.
Circ Arrhythm Electrophysiol ; 15(10): e010713, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36166682

RESUMO

BACKGROUND: Experimental data suggest ryanodine receptor-mediated intracellular calcium leak is a mechanism for atrial fibrillation (AF), but evidence in humans is still needed. Propafenone is composed of two enantiomers that are equally potent sodium-channel blockers; however, (R)-propafenone is an ryanodine receptor inhibitor whereas (S)-propafenone is not. This study tested the hypothesis that ryanodine receptor inhibition with (R)-propafenone prevents induction of AF compared to (S)-propafenone or placebo in patients referred for AF ablation. METHODS: Participants were randomized 4:4:1 to a one-time intravenous dose of (R)-propafenone, (S)-propafenone, or placebo. The study drug was given at the start of the procedure and an AF induction protocol using rapid atrial pacing was performed before ablation. The primary endpoint was 30 s of AF or atrial flutter. RESULTS: A total of 193 participants were enrolled and 165 (85%) completed the study protocol (median age: 63 years, 58% male, 95% paroxysmal AF). Sustained AF and/or atrial flutter was induced in 60 participants (84.5%) receiving (R)-propafenone, 60 (80.0%) receiving (S)-propafenone group, and 12 (63.2%) receiving placebo. Atrial flutter occurred significantly more often in the (R)-propafenone (N=23, 32.4%) and (S)-propafenone (N=26, 34.7%) groups compared to placebo (N=1, 5.3%, P=0.029). There was no significant difference between (R)-propafenone and (S)-propafenone for the primary outcome of AF and/or atrial flutter induction in univariable (P=0.522) or multivariable analysis (P=0.199, adjusted for age and serum drug level). CONCLUSIONS: There is no difference in AF inducibility between (R)-propafenone and (S)-propafenone at clinically relevant concentrations. These results are confounded by a high rate of inducible atrial flutter due to sodium-channel blockade. REGISTRATION: https://clinicaltrials.gov; Unique Identifier: NCT02710669.


Assuntos
Fibrilação Atrial , Flutter Atrial , Humanos , Masculino , Pessoa de Meia-Idade , Feminino , Propafenona/efeitos adversos , Canal de Liberação de Cálcio do Receptor de Rianodina , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/prevenção & controle , Fibrilação Atrial/tratamento farmacológico , Flutter Atrial/diagnóstico , Flutter Atrial/prevenção & controle , Cálcio/metabolismo , Sódio , Antiarrítmicos/uso terapêutico
12.
J Med Chem ; 65(4): 2880-2904, 2022 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-34347470

RESUMO

Starting from the MLPCN probe compound ML300, a structure-based optimization campaign was initiated against the recent severe acute respiratory syndrome coronavirus (SARS-CoV-2) main protease (3CLpro). X-ray structures of SARS-CoV-1 and SARS-CoV-2 3CLpro enzymes in complex with multiple ML300-based inhibitors, including the original probe ML300, were obtained and proved instrumental in guiding chemistry toward probe compound 41 (CCF0058981). The disclosed inhibitors utilize a noncovalent mode of action and complex in a noncanonical binding mode not observed by peptidic 3CLpro inhibitors. In vitro DMPK profiling highlights key areas where further optimization in the series is required to obtain useful in vivo probes. Antiviral activity was established using a SARS-CoV-2-infected Vero E6 cell viability assay and a plaque formation assay. Compound 41 demonstrates nanomolar activity in these respective assays, comparable in potency to remdesivir. These findings have implications for antiviral development to combat current and future SARS-like zoonotic coronavirus outbreaks.


Assuntos
Antivirais/farmacologia , Proteases 3C de Coronavírus/antagonistas & inibidores , Inibidores de Cisteína Proteinase/farmacologia , Peptidomiméticos/farmacologia , SARS-CoV-2/efeitos dos fármacos , Animais , Antivirais/síntese química , Antivirais/química , COVID-19/metabolismo , Chlorocebus aethiops , Proteases 3C de Coronavírus/isolamento & purificação , Proteases 3C de Coronavírus/metabolismo , Cristalografia por Raios X , Inibidores de Cisteína Proteinase/síntese química , Inibidores de Cisteína Proteinase/química , Relação Dose-Resposta a Droga , Glutamina/química , Glutamina/farmacologia , Humanos , Cetonas/química , Cetonas/farmacologia , Testes de Sensibilidade Microbiana , Modelos Moleculares , Estrutura Molecular , Peptidomiméticos/química , SARS-CoV-2/enzimologia , Células Vero , Replicação Viral/efeitos dos fármacos , Tratamento Farmacológico da COVID-19
13.
Parasitol Res ; 108(3): 679-85, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20967461

RESUMO

Intraspecific variability among Cystoisospora belli isolates and its clinical implications in human cystoisosporosis have not been established. In this study, the restriction fragment length polymorphisms in a 1.8-kb amplicon of the small subunit ribosomal DNA (SSU rDNA) of the parasite was investigated in 20 C. belli-positive stool samples obtained from 15 HIV-infected patients. Diarrheic syndrome was observed in all patients with cystoisosporosis and the number of diarrheic episodes per patient during hospitalization ranged from 1 to 26 (mean of 9.64 ± 9.30), with a mean duration of 2 to 12 days (mean of 5.90 ± 3 days). Three restriction profiles (RF) were generated with MboII digestion, which were named RFI, RFII, and RFIII. Two isolates obtained from a patient with extraintestinal cystoisosporosis showed distinct restriction profiles with MboII. This study demonstrates that patients can be infected with different C. belli genotypes, and this information may be useful for identifying new C. belli genotypes infecting humans.


Assuntos
Coccidiose/complicações , Coccidiose/parasitologia , DNA Ribossômico/genética , Infecções por HIV/complicações , Polimorfismo de Fragmento de Restrição , Sarcocystidae/genética , Sarcocystidae/isolamento & purificação , Adulto , DNA de Protozoário/genética , Fezes/parasitologia , Feminino , Genes de RNAr , Marcadores Genéticos , Humanos , Masculino , Reação em Cadeia da Polimerase , RNA Ribossômico 18S/genética , Adulto Jovem
14.
J Clin Pharmacol ; 61(3): 360-367, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32960980

RESUMO

Acute asthma exacerbations are primarily due to airway inflammation and remain one of the most frequent reasons for childhood hospitalizations. Although systemic corticosteroids remain the mainstay of therapy because of their anti-inflammatory properties, not all inflammatory pathways are responsive to systemic corticosteroids, necessitating hospital admission for further management. Cysteinyl leukotrienes (LTs) are proinflammatory mediators that play an important role in systemic corticosteroids non-responsiveness. Montelukast is a potent LT-receptor antagonist, and an intravenous preparation caused rapid, sustained improvement of acute asthma exacerbations in adults. We hypothesized that a 30-mg dose of oral montelukast achieves peak plasma concentrations (Cmax ), comparable to the intravenous preparation (1700 ng/mL) and would be well tolerated in 15 children aged 5 to 12 years with acute asthma exacerbations. After administration of montelukast chewable tablets, blood samples were collected at 0, 15, 30, 45, 60, 120, 180, and 240 minutes. Plasma was separated and frozen at -80°C until analysis for montelukast concentration using liquid chromatography- tandem mass spectrometry. Median time to Cmax (tmax ) was 3.0 hours. Six participants (40%) achieved Cmax of 1700 ng/mL or higher. However, there was high interindividual variability in peak plasma concentration (median Cmax of 1378 ng/mL; range, 16-4895 ng/mL). No participant had side effects or adverse events. Plasma concentrations from this pilot study support the design of a weight-based dose-finding study aimed at selecting an optimal dose for future clinical trials to assess the efficacy of high-dose oral montelukast in children with moderate to severe asthma exacerbations.


Assuntos
Acetatos/administração & dosagem , Antiasmáticos/administração & dosagem , Asma/tratamento farmacológico , Ciclopropanos/administração & dosagem , Antagonistas de Leucotrienos/administração & dosagem , Quinolinas/administração & dosagem , Sulfetos/administração & dosagem , Acetatos/efeitos adversos , Acetatos/farmacocinética , Administração Oral , Antiasmáticos/efeitos adversos , Antiasmáticos/farmacocinética , Asma/fisiopatologia , Peso Corporal , Criança , Pré-Escolar , Cromatografia Líquida , Ciclopropanos/efeitos adversos , Ciclopropanos/farmacocinética , Relação Dose-Resposta a Droga , Feminino , Humanos , Antagonistas de Leucotrienos/efeitos adversos , Antagonistas de Leucotrienos/farmacocinética , Masculino , Gravidade do Paciente , Projetos Piloto , Estudos Prospectivos , Quinolinas/efeitos adversos , Quinolinas/farmacocinética , Sulfetos/efeitos adversos , Sulfetos/farmacocinética , Comprimidos , Espectrometria de Massas em Tandem , Fatores de Tempo
15.
Trials ; 22(1): 576, 2021 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-34454591

RESUMO

BACKGROUND: Although catheter ablation is an effective therapy for atrial fibrillation (AF), the most common cardiac arrhythmia encountered in clinical practice, AF ablation generates inflammation and oxidative stress in the early postoperative period predisposing to recurrence of AF. Isolevuglandins (IsoLGs) are reactive lipid mediators of oxidative stress injury that rapidly react with endogenous biomolecules to compromise their function. 2-Hydroxybenzylamine (2-HOBA), a potent small molecule scavenger of IsoLGs, sequesters the reactive species as inert adducts. This mechanism, coupled with reported safety in humans, supports the investigation of 2-HOBA as a novel therapeutic to reduce AF caused by oxidative stress, such as that which occurs after catheter ablation. Accordingly, we seek to test the hypothesis that treatment with 2-HOBA will decrease early recurrence of AF and other atrial arrhythmias following AF ablation by decreasing IsoLG adducts with native biomolecules. METHODS: The proposed trial will randomly assign 162 participants undergoing cryo- or radiofrequency catheter ablation for AF to 2-HOBA (N = 81) or placebo (N = 81). Individuals will begin the study drug 3 days prior to ablation and continue for 28 days. Participants will be given a wearable smartwatch capable of detecting and recording atrial arrhythmias. They will be instructed to record ECGs daily with additional ECGs if they experience symptoms of AF or when alerted by the smartwatch AF detection alarm. The primary clinical endpoint will be an episode of AF, atrial tachycardia, or atrial flutter lasting 30 s or more within 28 days post-AF ablation. Secondary measures will be the change in IsoLG adduct levels from blood samples collected immediately pre-ablation and post-ablation and reduction in AF burden as calculated from the smartwatch. DISCUSSION: The proposed trial will test the hypothesis that 2-HOBA reduces post-ablation atrial arrhythmias through sequestration of reactive IsoLG species. The results of this study may improve the understanding of the role of IsoLGs and oxidative stress in AF pathogenesis and provide evidence to advance 2-HOBA and related compounds as a new therapeutic strategy to treat AF. TRIAL REGISTRATION: ClinicalTrials.gov NCT04433091 . Registered on June 3, 2020.


Assuntos
Fibrilação Atrial , Ablação por Cateter , Preparações Farmacêuticas , Dispositivos Eletrônicos Vestíveis , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/prevenção & controle , Fibrilação Atrial/cirurgia , Benzilaminas , Ablação por Cateter/efeitos adversos , Humanos , Recidiva Local de Neoplasia , Ensaios Clínicos Controlados Aleatórios como Assunto
16.
BMC Pharmacol Toxicol ; 21(1): 3, 2020 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-31907026

RESUMO

BACKGROUND: 2-Hydroxybenzylamine (2-HOBA) is a selective dicarbonyl electrophile scavenger being developed as a nutritional supplement to help protect against the development of conditions associated with dicarbonyl electrophile formation, such as the cognitive decline observed with Mild Cognitive Impairment or Alzheimer's disease. METHODS: This study evaluated the safety, tolerability, and pharmacokinetics of repeated oral doses of 2-HOBA acetate (500 or 750 mg) administered to healthy volunteers every eight hours for two weeks. The effects of 2-HOBA on cyclooxygenase function and cerebrospinal fluid penetrance of 2-HOBA were also investigated. RESULTS: Repeated oral administration of 2-HOBA was found to be safe and well-tolerated up to 750 mg TID for 15 days. 2-HOBA was absorbed within 2 h of administration, had a half-life of 2.10-3.27 h, and an accumulation ratio of 1.38-1.52. 2-HOBA did not interfere with cyclooxygenase function and was found to be present in cerebrospinal fluid 90 min after dosing. CONCLUSIONS: Repeated oral administration of 2-HOBA was found to be safe and well-tolerated. These results support continued development of 2-HOBA as a nutritional supplement. TRIAL REGISTRATION: Studies are registered at ClinicalTrials.gov (NCT03555682 Registered 13 June 2018, NCT03554096 Registered 12 June 18).


Assuntos
Benzilaminas/farmacocinética , Suplementos Nutricionais , Administração Oral , Adulto , Benzilaminas/efeitos adversos , Benzilaminas/sangue , Benzilaminas/líquido cefalorraquidiano , Método Duplo-Cego , Feminino , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
17.
Fitoterapia ; 138: 104357, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31521701

RESUMO

Three new 3-hydroxy-N-methyl-2-oxindole (1 and 2) and 4-hydroxy-pyran-2-one (3) derivatives, along with the known 3-hydroxy-N-methyl-2-oxindole (4) and 6-methoxy-N-methylisatin (5) were isolated from a marine Salinispora arenicola strain from sediments of the St. Peter and St. Paul Archipelago, Brazil. The structures of the new compounds were elucidated by a combination of spectroscopic (1D and 2D NMR and HR-ESIMS) data, including single-crystal X-ray diffraction analysis for 2 and 3. Compounds 1 to 5 were assayed for their antimicrobial properties, but only 4 and 5 were active against Enterococcus faecalis with MIC value of 15.6 µg/mL.


Assuntos
Antibacterianos/farmacologia , Sedimentos Geológicos/microbiologia , Micromonosporaceae/química , Oxindóis/farmacologia , Antibacterianos/isolamento & purificação , Brasil , Enterococcus faecalis/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Oxindóis/isolamento & purificação , Água do Mar/microbiologia
18.
Thromb Res ; 121(4): 527-34, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-17631948

RESUMO

BACKGROUND: Cangrelor is a direct, parenteral, and reversible inhibitor of the platelet P2Y12 receptor currently undergoing Phase III testing. As many individuals treated acutely with cangrelor will often be treated long-term with a thienopyridine, it is important to determine the effects of concurrent cangrelor and clopidogrel administration. METHODS AND RESULTS: Ten healthy volunteers received a 600 mg oral loading dose of clopidogrel and then underwent serial platelet function monitoring for 6 h. Two weeks later these same individuals received a 600 mg clopidogrel loading dose simultaneously with a cangrelor IV bolus (30 microg/kg) and a 2-hour infusion (4 microg/kg/min). A separate group of ten volunteers received a 600 mg clopidogrel loading dose after administration of a cangrelor bolus and a 1-hour infusion. The effects on ADP-induced platelet activation and aggregation were evaluated by flow cytometry, whole-blood electrical impedance, and light-transmittance aggregometry. Cangrelor and clopidogrel alone achieved the expected levels of platelet inhibition. However, the sustained platelet inhibition anticipated for clopidogrel treatment did not occur when cangrelor was initiated simultaneously. No such effect was found when clopidogrel was started upon completion of the cangrelor infusion. CONCLUSION: To achieve sustained platelet P2Y12 inhibition in patients treated with cangrelor, clopidogrel administration should be started when the cangrelor infusion is terminated.


Assuntos
Monofosfato de Adenosina/análogos & derivados , Inibidores da Agregação Plaquetária/farmacologia , Antagonistas do Receptor Purinérgico P2 , Ticlopidina/análogos & derivados , Difosfato de Adenosina/farmacologia , Monofosfato de Adenosina/farmacologia , Adolescente , Adulto , Clopidogrel , Inibidores de Ciclo-Oxigenase/farmacologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Selectina-P/sangue , Agregação Plaquetária/efeitos dos fármacos , Receptores Purinérgicos P2Y12 , Ticlopidina/farmacologia
19.
Int J Infect Dis ; 73: 93-101, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29879524

RESUMO

OBJECTIVE: To determine the course of serological tests in subjects with chronic Trypanosoma cruzi infection treated with anti-trypanosomal drugs. METHODS: A systematic review and meta-analysis was conducted using individual participant data. Survival analysis and the Cox proportional hazards regression model with random effects to adjust for covariates were applied. The protocol was registered in the PROSPERO database (http://www.crd.york.ac.uk/PROSPERO; CRD42012002162). RESULTS: A total of 27 studies (1296 subjects) conducted in eight countries were included. The risk of bias was low for all domains in 17 studies (63.0%). Nine hundred and thirteen subjects were assessed (149 seroreversion events, 83.7% censored data) for enzyme-linked immunosorbent assay (ELISA), 670 subjects (134 events, 80.0% censored) for indirect immunofluorescence assay (IIF), and 548 subjects (99 events, 82.0% censored) for indirect hemagglutination assay (IHA). A higher probability of seroreversion was observed within a shorter time span in subjects aged 1-19 years compared to adults. The chance of seroreversion also varied according to the country where the infection might have been acquired. For instance, the pooled adjusted hazard ratio between children/adolescents and adults for the IIF test was 1.54 (95% confidence interval 0.64-3.71) for certain countries of South America (Argentina, Bolivia, Chile, and Paraguay) and 9.37 (95% confidence interval 3.44-25.50) for Brazil. CONCLUSIONS: The disappearance of anti-T. cruzi antibodies was demonstrated along the course of follow-up. An interaction between age at treatment and country setting was found.


Assuntos
Anticorpos Antiprotozoários/sangue , Doença de Chagas/diagnóstico , Adolescente , Adulto , Criança , Pré-Escolar , Doença Crônica , Ensaio de Imunoadsorção Enzimática , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Testes de Hemaglutinação , Humanos , Lactente , Masculino , Testes Sorológicos , Adulto Jovem
20.
Surgery ; 140(4): 541-7; discussion 547-52, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17011901

RESUMO

BACKGROUND: Lifestyle modification and appropriate medical therapy improve long-term outcomes following coronary artery bypass grafting (CABG). Our institutional experience suggested that evidence-based recommendations were not being followed postdischarge after CABG. We undertook this study to document our rate of compliance with evidence-based guidelines and to correct deficiencies in our discharge practices. METHODS: Seven evidence-based interventions were studied after CABG: (1) institution of beta-blocker therapy, (2) angiotensin-converting enzyme (ACE) inhibitor therapy, (3) aspirin, (4) lipid-lowering therapy, (5) smoking cessation intervention, (6) heart-healthy diet therapy, and (7) physical activity recommendations. The rate of compliance with guidelines in 50 control patients was measured at discharge. A multidisciplinary team including cardiac surgeons, nurses, dieticians, physical therapists, and clinical pharmacists evaluated the guideline compliance in the control group and developed interventions to assure guideline compliance at the time of discharge. A subsequent study group of 50 patients was then assessed prospectively to measure the guideline compliance after institution of intervention programs. The multidisciplinary team agreed on predefined acceptable compliance limits as follows: (1) >80% of patients receive ACE inhibitors at discharge, (2) 100% of patients receive beta-blockers, aspirin, and lipid-lowering agents at discharge, and (3) 100% of patients receive lifestyle modification counseling at discharge. Compliance with guidelines was defined as documentation in the medical record of provision of medications and lifestyle counseling at the time of discharge. RESULTS: In the control group, the rate of guideline compliance was surprisingly low. Rates of compliance with guidelines increased significantly after the multidisciplinary interventions were undertaken. CONCLUSIONS: We conclude that compliance with guidelines known to improve long-term outcome is suboptimal after CABG. A multidisciplinary intervention program can improve compliance with currently accepted guidelines and quality indicators in patients following CABG.


Assuntos
Ponte de Artéria Coronária/psicologia , Doença da Artéria Coronariana/psicologia , Doença da Artéria Coronariana/cirurgia , Cooperação do Paciente , Educação de Pacientes como Assunto , Antagonistas Adrenérgicos beta/uso terapêutico , Idoso , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Doença da Artéria Coronariana/tratamento farmacológico , Medicina Baseada em Evidências , Feminino , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Alta do Paciente , Complicações Pós-Operatórias/prevenção & controle , Complicações Pós-Operatórias/psicologia , Guias de Prática Clínica como Assunto
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