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1.
J Diabetes Complications ; 38(12): 108882, 2024 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-39437698

RESUMO

INTRODUCTION: Diabetic Ketoacidosis (DKA) is commonly treated with intravenous (IV) regular insulin. However, patients with less severe DKA may benefit from a subcutaneous (SC) scheme. METHODS: We systematically searched PubMed, Cochrane, and Embase for randomized controlled trials (RCTs) comparing SC rapid-acting insulin analogue (RAIAs) with IV regular insulin. Risk ratios (RR) were used to compare treatment effects for binary outcomes and mean differences (MD) for continuous data with the corresponding 95 % confidence intervals (CI). P values <0.05 were considered statistically significant. We used the R version 4.3.2 for statistical analyses. RESULTS: Our meta-analysis included eight RCTs encompassing 415 patients. No statistically significant differences were found between RAIAs and IV regular insulin in the treatment of mild to moderate DKA in the pediatric and adult population in the primary outcome of time until DKA resolution (MD 0.00 h; 95 % CI -1.27 to 1.28; P = 1.00). Both treatments showed comparable results in the secondary outcomes total insulin usage (P = 0.65), time until hyperglycemia resolution (P = 0.22), length of hospital stay (P = 0.11), the incidence of hypoglycemia (P = 0.15) and DKA recurrence (P = Not estimable). There were no reports of death, cerebral edema, or venous thrombosis in the studies. CONCLUSION: In this meta-analysis of eight RCTs we found that SC RAIAs and regular IV insulin are comparable in resolving mild to moderate DKA in children and adults. PROSPERO registration: CRD42023485032.

2.
Res Sq ; 2024 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-39399671

RESUMO

The precise mode of action of ganaplacide (KAF156), a phase III antimalarial candidate, remains elusive. Here we employ omics-based methods with the closely related chemical analog, GNF179, to search for potential Plasmodium targets. Ranking potential targets derived from chemical genetics and proteomic affinity chromatography methodologies identifies SEY1, or Synthetic Enhancement of YOP1, which is predicted to encode an essential dynamin-like GTPase implicated in homotypic fusion of endoplasmic reticulum (ER) membranes. We demonstrate that GNF179 decreases Plasmodium SEY1 melting temperature. We further show that GNF179 binds to recombinant Plasmodium SEY1 and subsequently inhibits its GTPase activity, which is required for maintaining ER architecture. Using ultrastructure expansion microscopy, we find GNF179 treatment changes parasite ER and Golgi morphology. We also confirm that SEY1 is an essential gene in P. falciparum. These data suggest that SEY1 may contribute to the mechanism of action of imidazolopiperazines and is a new and attractive druggable target.

3.
Proc Natl Acad Sci U S A ; 121(45): e2407112121, 2024 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-39471225

RESUMO

Coral reefs are among the most sensitive ecosystems affected by ocean warming and acidification, and are predicted to collapse over the next few decades. Reefs are predicted to shift from net accreting calcifier-dominated systems with exceptionally high biodiversity to net eroding algal-dominated systems with dramatically reduced biodiversity. Here, we present a two-year experimental study examining the responses of entire mesocosm coral reef communities to warming (+2 °C), acidification (-0.2 pH units), and combined future ocean (+2 °C, -0.2 pH) treatments. Contrary to modeled projections, we show that under future ocean conditions, these communities shift structure and composition yet persist as novel calcifying ecosystems with high biodiversity. Our results suggest that if climate change is limited to Paris Climate Agreement targets, coral reefs could persist in an altered state rather than collapse.


Assuntos
Recifes de Corais , Aquecimento Global , Acidificação dos Oceanos , Oceanos e Mares , Água do Mar/química , Biodiversidade , Previsões , Animais
4.
Artigo em Inglês | MEDLINE | ID: mdl-39476219

RESUMO

This case report refers to a 1-year-old Guinea pig showing signs of anorexia and antipain posture. On abdominal radiography, five rounded mineral opaque structures were evident in the mid-caudal abdomen. On ultrasound, a right seminal vesicle with a reduction in diameter was observed, containing less echogenic material than the contralateral one, with five oval structures with a hyperechogenic contour and a central hypoechogenic area, forming acoustic shadowing. The left seminal vesicle presented with the usual characteristics. After bilateral vesiculectomy, the patient recovered well, with no further symptoms. The histopathological result was a suppurative/abscessive inflammatory process with an accumulation of proteinaceous material.

5.
Top Companion Anim Med ; 62: 100905, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39117069

RESUMO

The aim of this study was to develop a novel surgical technique for stifle arthrodesis in dogs using a semicircular saw for tibial and femoral ostectomies through a medial approach. Ten pelvic limbs from five canine cadavers underwent stifle arthrodesis. Prior to the surgical procedure, the limbs were radiographed to rule out musculoskeletal abnormalities. Additionally, the radiographs were used for surgical planning. For the tibial ostectomy, the center of the intercondylar eminences, the cranial limit of the tibial plateau, and the caudal cortex of the tibia were used as landmarks. In the femur, the groove of the insertion of the long digital extensor tendon and the caudal portion of the femoral cortex served as references. The most significant iatrogenic injury during the surgical procedures was the complete rupture of the long digital extensor tendon during the tibial cut in one of the stifles. Dome ostectomies facilitated interfragmentary contact, allowing for adjustment of the angulation between the fragments without the need for additional ostectomies or osteotomies. The medial approach provided a clear view of intra-articular structures without causing extensive damage to surrounding tissues. After the procedures, the limbs were radiographed to calculate angular measurements, and the final angulation (mean) of the knee joints was 134.7 ± 11°.


Assuntos
Artrodese , Cadáver , Joelho de Quadrúpedes , Animais , Cães/cirurgia , Artrodese/veterinária , Artrodese/métodos , Joelho de Quadrúpedes/cirurgia , Joelho de Quadrúpedes/diagnóstico por imagem , Tíbia/cirurgia , Osteotomia/veterinária , Osteotomia/métodos , Fêmur/cirurgia
6.
J Diabetes Complications ; 38(10): 108834, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39178623

RESUMO

BACKGROUND: The efficacy of GLP1 receptor agonists (GLP1-RAs) in treating polycystic ovarian syndrome (PCOS) remains unclear. While GLP1-RAs are known to promote weight loss in patients with diabetes and living with obesity, their impact on weight reduction and hormonal regulation in women with PCOS is understudied. Therefore, we aimed to assess the efficacy of GLP1-RAs in PCOS women living with obesity through a meta-analysis, comparing their effects to placebo. HYPOTHESIS: The use of GLP1-RAs in PCOS women living with obesity can reduce body mass index and waist circumference as well as improve hyperinsulinism, and hyperandrogenism as well as normalize total testosterone, total cholesterol and HOMA-IR markers in PCOS women living with obesity. METHODS: We systematically searched the PubMed, Cochrane Central, Scopus and Embase databases to identify randomized controlled trials (RCT) comparing GLP1-RAs versus placebo among women diagnosed with PCOS based on the Rotterdam Criteria. Our primary outcomes of interest included body mass index (BMI), triglycerides, waist circumference, total testosterone, total cholesterol, and HOMA-IR. We performed data extraction and quality assessment for studies that met the inclusion criteria. We pooled mean difference (MD) and 95 % confidence intervals (CI) with a random-effect model for continuous endpoints. RESULTS: We included 176 participants from four RCTs. Semaglutide and Liraglutide were used in 23 (13 %) and 103 (58 %) participants, respectively. GLP1-RAs use was associated with a significant reduction in waist circumference (MD: -5.16 cm; 95 % CI: -6.11 to -4.21; p ˂ 0.00001), body mass index (BMI) (MD: -2.42; 95 % CI: -3.10 to -1.74; p ˂ 0.00001), serum triglycerides (MD: -0.20; 95 % CI: -0.30 to -0.11; p ˂ 0.00001) and total testosterone levels (MD: -1.33; 95 % CI: -2.55 to -0.12; p = 0.03) when compared to placebo. There was no significant difference in total cholesterol (MD: -0.04; 95 % CI: -0.10 to 0.01; p = 0.15) and HOMA-IR (MD: -0.30; 95 % CI: -0.92 to 0.32; p = 0.35) levels. Adverse events information was available for 112 patients, where 49 had light side effects such as nausea and abdominal pain. CONCLUSION: The use of GLP1-RAs demonstrates efficacy in reducing BMI, triglycerides, waist circumference and total testosterone. There was no significant difference in total cholesterol and HOMA-IR levels. These results signify its viability as a favourable treatment option for managing PCOS symptoms in women living with obesity.


Assuntos
Obesidade , Síndrome do Ovário Policístico , Ensaios Clínicos Controlados Aleatórios como Assunto , Redução de Peso , Humanos , Síndrome do Ovário Policístico/complicações , Síndrome do Ovário Policístico/tratamento farmacológico , Síndrome do Ovário Policístico/sangue , Feminino , Redução de Peso/efeitos dos fármacos , Obesidade/complicações , Obesidade/tratamento farmacológico , Obesidade/sangue , Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas , Liraglutida/uso terapêutico , Resultado do Tratamento , Testosterona/sangue , Índice de Massa Corporal , Hipoglicemiantes/uso terapêutico , Adulto , Circunferência da Cintura/efeitos dos fármacos , Resistência à Insulina
7.
Eur J Med Chem ; 277: 116782, 2024 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-39208744

RESUMO

Dynamics of epigenetic modifications such as acetylation and deacetylation of histone proteins have been shown to be crucial for the life cycle development and survival of Plasmodium falciparum, the deadliest malaria parasite. In this study, we present a novel series of peptoid-based histone deacetylase (HDAC) inhibitors incorporating nitrogen-containing bicyclic heteroaryl residues as a new generation of antiplasmodial peptoid-based HDAC inhibitors. We synthesized the HDAC inhibitors by an efficient multicomponent protocol based on the Ugi four-component reaction. The subsequent screening of 16 compounds from our mini-library identified 6i as the most promising candidate, demonstrating potent activity against asexual blood-stage parasites (IC50Pf3D7 = 30 nM; IC50PfDd2 = 98 nM), low submicromolar activity against liver-stage parasites (IC50PbEEF = 0.25 µM), excellent microsomal stability (t1/2 > 60 min), and low cytotoxicity to HEK293 cells (IC50 = 136 µM).


Assuntos
Antimaláricos , Inibidores de Histona Desacetilases , Peptoides , Plasmodium falciparum , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/enzimologia , Inibidores de Histona Desacetilases/farmacologia , Inibidores de Histona Desacetilases/química , Inibidores de Histona Desacetilases/síntese química , Humanos , Antimaláricos/farmacologia , Antimaláricos/química , Antimaláricos/síntese química , Peptoides/farmacologia , Peptoides/química , Peptoides/síntese química , Relação Estrutura-Atividade , Células HEK293 , Testes de Sensibilidade Parasitária , Estrutura Molecular , Relação Dose-Resposta a Droga , Histona Desacetilases/metabolismo
9.
J Gen Intern Med ; 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38997531

RESUMO

INTRODUCTION: Although a well-established component of bone metabolism, the efficacy and safety of vitamin D supplementation for the prevention of fractures in elderly healthy individuals is still unclear. PURPOSE: To perform a meta-analysis comparing vitamin D supplementation with placebo and its contributions on fracture incidence. METHODS: This meta-analysis was registered in the International Prospective Register of Systematic Reviews (PROSPERO), under protocol CRD42023484979. We systematically searched PubMed, Embase, and Cochrane Central databases from inception to November 2023 for randomized controlled trials (RCTs) comparing vitamin D supplementation versus placebo in individuals with 60 years of age or more and without bone related medical conditions such as cancer and osteoporosis. RESULTS: Seven RCTs with 71,899 patients were included, of whom 36,822 (51.2%) were women. There was no significant difference in total fracture incidence (RR 1.03; 95% CI 0.93-1.14; p = 0.56; I2 = 58%) between groups or subgroups. However, women had an increased risk for hip fractures (164 vs. 121 events; RR 1.34; 95% CI 1.06-1.70; p = 0.01; I2 = 0%). There was no significant difference in non-vertebral fractures, osteoporotic fractures development, or falls (RR 1.02; 95% CI 0.94-1.12; p = 0.6; I2 = 47%; RR 0.97; 95% CI 0.87-1.08; p = 0.63; I2 = 0%; RR 1.01; 95% CI 0.97-1.04; p = 0.66; I2 = 55%, respectively). CONCLUSION: Vitamin D supplementation does not reduce the total fracture development rate in the elderly healthy population, and it may increase the incidence of hip fractures among elderly healthy women. This finding suggests refraining from prescribing high intermittent doses of vitamin D, without calcium, to individuals aged 60 or older with unknown vitamin D serum concentration or osteoporosis status and inadequate calcium intake.

10.
ChemMedChem ; 19(20): e202400293, 2024 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-38924252

RESUMO

This study introduces further insights from the hit-to-lead optimization process involving a series of benzimidazole derivatives acting as inhibitors of the cruzain enzyme, which targets Trypanosoma cruzi, the causative parasite of Chagas disease. Here, we present the design, synthesis and biological evaluation of 30 new compounds as a third generation of benzimidazole analogues with trypanocidal activity, aiming to enhance our understanding of their pharmacokinetic profiles and establish a structure-metabolism relationships within the series. The design of these new analogues was guided by the analysis of previous pharmacokinetic results, considering identified metabolic sites and biotransformation studies. This optimization resulted in the discovery of two compounds (42 e and 49 b) exhibiting enhanced metabolic stability, anti-Trypanosoma cruzi activity compared to benznidazole (the reference drug for Chagas disease), as well as being non-cruzain inhibitors, and demonstrating a satisfactory in vitro pharmacokinetic profile. These findings unveil a new subclass of aminobenzimidazole and rigid compounds, which offer potential for further exploration in the quest for discovering novel classes of antichagasic compounds.


Assuntos
Benzimidazóis , Doença de Chagas , Tripanossomicidas , Trypanosoma cruzi , Trypanosoma cruzi/efeitos dos fármacos , Benzimidazóis/química , Benzimidazóis/farmacologia , Benzimidazóis/síntese química , Relação Estrutura-Atividade , Tripanossomicidas/farmacologia , Tripanossomicidas/química , Tripanossomicidas/síntese química , Doença de Chagas/tratamento farmacológico , Estrutura Molecular , Testes de Sensibilidade Parasitária , Humanos , Animais , Relação Dose-Resposta a Droga
11.
Can Geriatr J ; 27(2): 133-140, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38827426

RESUMO

Background: Resistance training with instability (REI) emerged as a promising training modality for older adults aiming to counteract age-related changes. Objectives: We compared the effects of 12 weeks of REI and traditional resistance exercise (RE) on muscle strength in older adults with cognitive impairment. We further explored if total training volume (TTV) significantly differs among training groups. Methods: This is a secondary analysis of the REI study. Participants were randomly assigned to REI (n=22) or RE (n=23). RE protocol involved moderate-intensity, free-weight, and machines-based resistance exercises (3 sets, 10-15 repetitions). REI received a similar training protocol, in which exercises were simultaneously performed with instability/unstable devices (e.g., squat exercise under a foam pad or Bosu® ball). Maximal isometric strength and isokinetic parameters were assessed at baseline and after completion of a 12-week intervention through a hydraulic handgrip and isokinetic dynamometer, respectively. TTV (sets × repetitions × load) was computed based on external training load over the 12 weeks. Results: No differences were observed between groups (p=.35) after the intervention. Over 12 weeks, REI and RE improved isometric handgrip strength (p<.001) and isokinetic performance (p=.04). We also did not find differences in the TTV between training groups (p=.28). Conclusion: We demonstrated that both REI and RE training induced similar gains in muscle strength. Combining unstable surfaces/instability devices did not hamper TTV, which may have clinical applications in the context of exercise for older adults.

12.
J Intensive Care Med ; : 8850666241255671, 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38751353

RESUMO

Introduction: Glycemia is an important factor among critically ill patients in the intensive care unit (ICU). There is conflicting evidence on the preferred strategy of blood glucose control among patients with diabetes in the ICU. We aimed to conduct a meta-analysis comparing tight with liberal blood glucose in critically ill patients with diabetes in the ICU. Methods: We systematically searched PubMed, Embase, and Cochrane Central for randomized controlled trials (RCTs) comparing tight versus liberal blood glucose control in critically ill patients with diabetes from inception to December 2023. We pooled odds-ratios (OR) and 95% confidence intervals (CI) with a random-effects model for binary endpoints. We used the Review Manager 5.17 and R version 4.3.2 for statistical analyses. Risk of bias assessment was performed with the Cochrane tool for randomized trials (RoB2). Results: Eight RCTs with 4474 patients were included. There was no statistically significant difference in all-cause mortality (OR 1.11; 95% CI 0.95-1.28; P = .18; I² = 0%) between a tight and liberal blood glucose control. RoB2 identified all studies at low risk of bias and funnel plot suggested no evidence of publication bias. Conclusion: In patients with diabetes in the ICU, there was no statistically significant difference in all-cause mortality between a tight and liberal blood glucose control. PROSPERO registration: CRD42023485032.

13.
Expert Opin Drug Discov ; 19(6): 741-753, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38715393

RESUMO

INTRODUCTION: Benznidazole, the drug of choice for treating Chagas Disease (CD), has significant limitations, such as poor cure efficacy, mainly in the chronic phase of CD, association with side effects, and parasite resistance. Understanding parasite resistance to benznidazole is crucial for developing new drugs to treat CD. AREAS COVERED: Here, the authors review the current understanding of the molecular basis of benznidazole resistance. Furthermore, they discuss the state-of-the-art methods and critical outcomes employed to evaluate the efficacy of potential drugs against T. cruzi, aiming to select better compounds likely to succeed in the clinic. Finally, the authors describe the different strategies employed to overcome resistance to benznidazole and find effective new treatments for CD. EXPERT OPINION: Resistance to benznidazole is a complex phenomenon that occurs naturally among T. cruzi strains. The combination of compounds that inhibit different metabolic pathways of the parasite is an important strategy for developing a new chemotherapeutic protocol.


Assuntos
Doença de Chagas , Descoberta de Drogas , Resistência a Medicamentos , Nitroimidazóis , Tripanossomicidas , Trypanosoma cruzi , Trypanosoma cruzi/efeitos dos fármacos , Nitroimidazóis/farmacologia , Doença de Chagas/tratamento farmacológico , Doença de Chagas/parasitologia , Tripanossomicidas/farmacologia , Humanos , Animais , Descoberta de Drogas/métodos , Desenvolvimento de Medicamentos
14.
Water Sci Technol ; 89(8): 2105-2117, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38678412

RESUMO

Photodynamic processes have found widespread application in therapies. These processes involve photosensitizers (PSs) that, when excited by specific light wavelengths and in the presence of molecular oxygen, generate reactive oxygen species (ROS), that target cells leading to inactivation. Photodynamic action has gained notable attention in environmental applications, particularly against pathogens and antibiotic-resistant bacteria (ARB) that pose a significant challenge to public health. However, environmental matrices frequently encompass additional contaminants and interferents, including microplastics (MPs), which are pollutants of current concern. Their presence in water and effluents has been extensively documented, highlighting their impact on conventional treatment methods, but this information remains scarce in the context of photodynamic inactivation (PDI) setups. Here, we described the effects of polyvinyl chloride (PVC) microparticles in PDI targeting Staphylococcus aureus and its methicillin-resistant strain (MRSA), using curcumin as a PS under blue light. The presence of PVC microparticles does not hinder ROS formation; however, depending on its concentration, it can impact bacterial inactivation. Our results underscore that PDI remains a potent method for reducing bacterial concentrations in water and wastewater containing ARB, even in highly contaminated scenarios with MPs.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Microplásticos , Cloreto de Polivinila , Staphylococcus aureus , Cloreto de Polivinila/química , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos da radiação , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/efeitos da radiação , Espécies Reativas de Oxigênio/metabolismo , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/química
15.
Braz J Microbiol ; 55(2): 1339-1348, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38438832

RESUMO

Bacterial meningitis is still a significant public health concern, with high morbidity and mortality rates. Despite this, it is still a rare event that requires the bacterial invasion of the meninges. However, some predisposing factors can trigger recurrent episodes of meningitis. This study is aimed at determining the clinical characteristics and the molecular epidemiology of episodes of recurrent community-acquired meningitis with and without predisposing factors. For this purpose, we performed a retrospective study of our laboratory database during the period of 2010 to 2020. Additionally, using molecular tools developed in our previous works, the epidemiology of the pathogens causing these episodes was analyzed using cerebrospinal fluid samples, especially in the absence of isolated strains. We observed a total of 1,779 meningitis cases and 230 were caused by Streptococcus pneumoniae. Of those, 16 were recurrent meningitis episodes (16/1,779; 0.9%) from seven patients. Pneumococcus was the main agent responsible in these recurrent episodes and only two episodes were caused by Haemophilus influenzae. The mean age of these patients was 20 years old and three had predisposing factors which could have led to contracting meningitis. The samples presented different pneumococcal serotypes. Most of them were non-vaccine-covered serotypes and antibiotic susceptible strains. Therefore, it was demonstrated how the practical employment of molecular tools, developed for research, when applied in the routine of diagnosis, can provide important information for epidemiological surveillance. Furthermore, it was shown how pneumococcus was the leading cause of recurrent community-acquired meningitis without predisposing factors, suggesting that pneumococcal vaccination may be necessary, even in those groups of individuals considered to be less susceptible.


Assuntos
Infecções Comunitárias Adquiridas , Meningite Pneumocócica , Recidiva , Streptococcus pneumoniae , Humanos , Infecções Comunitárias Adquiridas/microbiologia , Infecções Comunitárias Adquiridas/epidemiologia , Meningite Pneumocócica/epidemiologia , Meningite Pneumocócica/microbiologia , Adulto , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/isolamento & purificação , Streptococcus pneumoniae/classificação , Estudos Retrospectivos , Feminino , Masculino , Adulto Jovem , Pessoa de Meia-Idade , Adolescente , Fatores de Risco , Sorogrupo , Antibacterianos , Haemophilus influenzae/genética , Haemophilus influenzae/isolamento & purificação , Haemophilus influenzae/classificação
16.
J Med Chem ; 67(5): 3467-3503, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38372781

RESUMO

Controlling malaria requires new drugs against Plasmodium falciparum. The P. falciparum cGMP-dependent protein kinase (PfPKG) is a validated target whose inhibitors could block multiple steps of the parasite's life cycle. We defined the structure-activity relationship (SAR) of a pyrrole series for PfPKG inhibition. Key pharmacophores were modified to enable full exploration of chemical diversity and to gain knowledge about an ideal core scaffold. In vitro potency against recombinant PfPKG and human PKG were used to determine compound selectivity for the parasite enzyme. P. berghei sporozoites and P. falciparum asexual blood stages were used to assay multistage antiparasitic activity. Cellular specificity of compounds was evaluated using transgenic parasites expressing PfPKG carrying a substituted "gatekeeper" residue. The structure of PfPKG bound to an inhibitor was solved, and modeling using this structure together with computational tools was utilized to understand SAR and establish a rational strategy for subsequent lead optimization.


Assuntos
Antimaláricos , Malária Falciparum , Animais , Humanos , Antimaláricos/farmacologia , Malária Falciparum/tratamento farmacológico , Plasmodium falciparum , Animais Geneticamente Modificados , Relação Estrutura-Atividade
17.
Nat Commun ; 15(1): 937, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38297033

RESUMO

Malaria poses an enormous threat to human health. With ever increasing resistance to currently deployed drugs, breakthrough compounds with novel mechanisms of action are urgently needed. Here, we explore pyrimidine-based sulfonamides as a new low molecular weight inhibitor class with drug-like physical parameters and a synthetically accessible scaffold. We show that the exemplar, OSM-S-106, has potent activity against parasite cultures, low mammalian cell toxicity and low propensity for resistance development. In vitro evolution of resistance using a slow ramp-up approach pointed to the Plasmodium falciparum cytoplasmic asparaginyl-tRNA synthetase (PfAsnRS) as the target, consistent with our finding that OSM-S-106 inhibits protein translation and activates the amino acid starvation response. Targeted mass spectrometry confirms that OSM-S-106 is a pro-inhibitor and that inhibition of PfAsnRS occurs via enzyme-mediated production of an Asn-OSM-S-106 adduct. Human AsnRS is much less susceptible to this reaction hijacking mechanism. X-ray crystallographic studies of human AsnRS in complex with inhibitor adducts and docking of pro-inhibitors into a model of Asn-tRNA-bound PfAsnRS provide insights into the structure-activity relationship and the selectivity mechanism.


Assuntos
Antimaláricos , Aspartato-tRNA Ligase , Animais , Humanos , Plasmodium falciparum/genética , Asparagina/metabolismo , Aspartato-tRNA Ligase/genética , Aminoacil-RNA de Transferência/metabolismo , Antimaláricos/farmacologia , Mamíferos/genética
18.
J Med Chem ; 67(2): 1460-1480, 2024 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-38214254

RESUMO

While progress has been made in the effort to eradicate malaria, the disease remains a significant threat to global health. Acquired resistance to frontline treatments is emerging in Africa, urging a need for the development of novel antimalarial agents. Repurposing human kinase inhibitors provides a potential expedited route given the availability of a diverse array of kinase-targeting drugs that are approved or in clinical trials. Phenotypic screening of a library of type II human kinase inhibitors identified compound 1 as a lead antimalarial, which was initially developed to target human ephrin type A receptor 2 (EphA2). Here, we report a structure-activity relationship study and lead optimization of compound 1, which led to compound 33, with improved antimalarial activity and selectivity.


Assuntos
Antimaláricos , Malária , Receptor EphA2 , Humanos , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Malária/tratamento farmacológico , Relação Estrutura-Atividade , África , Plasmodium falciparum
19.
Future Med Chem ; 16(3): 253-269, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38193294

RESUMO

Background: Chagas disease is caused by the parasite Trypanosoma cruzi, and the lack of effective and safe treatments makes identifying new classes of compounds with anti-T. cruzi activity of paramount importance. Methods: Hit-to-lead exploration of a metabolically stable N-imidazoylpiperazine was performed. Results: Compound 2, a piperazine derivative active against T. cruzi, was selected to perform the hit-to-lead exploration, which involved the design, synthesis and biological evaluation of 39 new derivatives. Conclusion: Compounds 6e and 10a were identified as optimized compounds with low micromolar in vitro activity, low cytotoxicity and suitable preliminary absorption, distribution, metabolism and excretion and physicochemical properties. Both compounds reduced parasitemia in mouse models of Chagas disease, providing a promising opportunity for further exploration of new antichagasic compounds.


Assuntos
Doença de Chagas , Tripanossomicidas , Trypanosoma cruzi , Animais , Camundongos , Tripanossomicidas/farmacologia , Tripanossomicidas/química , Doença de Chagas/tratamento farmacológico , Doença de Chagas/parasitologia , Relação Estrutura-Atividade , Parasitemia/tratamento farmacológico
20.
BMC Sports Sci Med Rehabil ; 16(1): 5, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38167062

RESUMO

BACKGROUND: Breast cancer (BC) is one of the most incident types of cancer among women in the world. Although chemotherapy is an effective way to treat several types of cancer, it may also cause serious complications, including cardiotoxicity. This study aimed to identify the impact of chemotherapy on functional capacity, muscle strength and autonomic function. METHODS: Ten breast cancer patients in therapeutic follow-up (TG) and ten women without comorbidities (CG) participated in the study (46±8.87 years old). Both groups were evaluated at two time points, before and 20 weeks after the start of chemotherapy. Functional capacity and muscle strength were assessed by 6-minute walk test (6MWT) and handgrip test, respectively. Autonomic function was assessed by heart rate variability analysis. RESULTS: TG presented greater reductions in the handgrip test for the non-dominant hand (TG ↓15.2%; CG: ↑1.1%, p<0.05) compared to GC. However, no significant differences were found regarding VO2max (p>0.05) and 6MWT total distance (p>0.05). Regarding the heart rate variability variables before and after follow-up period, rMSSD (CG= 39.15±37.66; TG= 14.89±8.28, p= 0.01) and SDNN (CG= 55.77±40.03; TG= 26.30±10.37, p= 0.02) showed effect in the group and time interaction, whereas the LF/HF ratio presented significant difference only in the time analysis (CG= 2.24±2.30; TG= 2.84±1.82, p= 0.04). CONCLUSION: Chemotherapy used in the treatment of breast cancer patients resulted in decreased muscle strength and autonomic imbalance. The data suggests that chemotherapy may carry the risk of developing cardiovascular disease. TRIAL REGISTRATION: Registration not required.

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