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Urinary tract infections are one of the most common types of bacterial infections in childhood. Normally, empiric antibiotic therapy is given based on local antimicrobial susceptibility. We performed a retrospective study to evaluate bacterial resistance and clinical responses to antibiotics in childhood febrile urinary tract infections (fUTIs) in the Bratislava region of Slovakia. A total of 182 children with a fUTI were enrolled in our retrospective study. 84,07% of these fUTIs were caused by pathogenic Escherichia coli (E. coli). According to microbial antibiotic susceptibility tests, the most effective antibiotic agents were third-generation cephalosporins (susceptibility was observed in 92,16% (n=141) of the cases), followed by aminopenicillins with betalactamase inhibitor (susceptibility was observed in 84,97% (n=130) of the cases) and trimethoprim-sulfamethoxazole (susceptibility was observed in 79,74% (n=122) of the cases). In contrast, E. coli was susceptible to second-generation cephalosporins in just 3,92% (n=6). Patients treated with third-generation cephalosporins achieved a clinical response to therapy almost in all of the cases (95,7% (n=66)), whereas second-generation cephalosporins were associated with a clinical response to therapy in only 55,9% (n=33) of the cases. Third-generation cephalosporins and aminopenicillins with a betalactamase inhibitor appear to be the most suitable initial antibiotic therapies in pediatric patients with fUTIs. Following current guidelines alongside the regular assessment of regional microbial antibiotic susceptibilities should provide the best treatment management for children with fUTIs.
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Herein, we report the identification and optimization of a series of potent inhibitors of EGFR Exon20 insertions with significant selectivity over wild-type EGFR. A strategically designed HTS campaign, multiple iterations of structure-based drug design (SBDD), and tactical linker replacement led to a potent and wild-type selective series of molecules and ultimately the discovery of 36. Compound 36 is a potent and selective inhibitor of EGFR Exon20 insertions and has demonstrated encouraging efficacy in NSCLC EGFR CRISPR-engineered H2073 xenografts that carry an SVD Exon20 insertion and reduced efficacy in a H2073 wild-type EGFR xenograft model compared to CLN-081 (5), indicating that 36 may have lower EGFR wild-type associated toxicity.
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Receptores ErbB , Éxons , Inibidores de Proteínas Quinases , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/genética , Receptores ErbB/metabolismo , Humanos , Animais , Relação Estrutura-Atividade , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/uso terapêutico , Linhagem Celular Tumoral , Camundongos , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Antineoplásicos/uso terapêutico , Descoberta de Drogas , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/genética , Mutagênese Insercional , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Ensaios Antitumorais Modelo de Xenoenxerto , MutaçãoRESUMO
BACKGROUND: Genetic nephrotic syndrome is caused by pathogenic variants in genes encoding proteins necessary for the stability and functionality of the glomerular filtration barrier. To date, more than 70 genes associated with steroid-resistant nephrotic syndrome have been identified. We review the clinical and molecular aspects of genetic nephrotic syndrome with a particular focus on genes associated with slit membrane and podocyte cytoskeleton defects. Sanger sequencing and next-generation sequencing are widely used in the identification of novel gene variants and help us gain a better understanding of the disease. Despite these findings, therapy is mainly supportive and focused on the reduction of proteinuria and management of chronic kidney disease with an unfavorable outcome for a significant proportion of cases. Positive therapeutic effects of immunosuppressive drugs have been reported in some patients; however, their long-time administration cannot be generally recommended. CONCLUSION: Personalized treatment based on understanding the distinct disease pathogenesis is needed. With this, it will be possible to avoid harmful immunosuppressive therapy and improve outcomes and quality of life for pediatric patients suffering from genetic nephrotic syndrome.
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Nefropatias , Síndrome Nefrótica , Podócitos , Humanos , Criança , Podócitos/metabolismo , Síndrome Nefrótica/etiologia , Qualidade de Vida , Glomérulos Renais/patologia , Nefropatias/patologia , Citoesqueleto/metabolismo , Citoesqueleto/patologiaRESUMO
The receptor tyrosine kinase, MERTK, plays an essential role in homeostasis of the retina via efferocytosis of shed outer nuclear segments of photoreceptors. The Royal College of Surgeons rat model of retinal degeneration has been linked to loss-of-function of MERTK, and together with the MERTK knock-out mouse, phenocopy retinitis pigmentosa in humans with MERTK mutations. Given recent efforts and interest in MERTK as a potential immuno-oncology target, development of a strategy to assess ocular safety at an early pre-clinical stage is critical. We have applied a state-of-the-art, multi-modal imaging platform to assess the in vivo effects of pharmacological inhibition of MERTK in mice. This involved the application of mass spectrometry imaging (MSI) to characterize the ocular spatial distribution of our highly selective MERTK inhibitor; AZ14145845, together with histopathology and transmission electron microscopy to characterize pathological and ultra-structural change in response to MERTK inhibition. In addition, we assessed the utility of a human retinal in vitro cell model to identify perturbation of phagocytosis post MERTK inhibition. We identified high localized total compound concentrations in the retinal pigment epithelium (RPE) and retinal lesions following 28 days of treatment with AZ14145845. These lesions were present in 4 of 8 treated animals, and were characterized by a thinning of the outer nuclear layer, loss of photoreceptors (PR) and accumulation of photoreceptor outer segments at the interface of the RPE and PRs. Furthermore, the lesions were very similar to that shown in the RCS rat and MERTK knock-out mouse, suggesting a MERTK-induced mechanism of PR cell death. This was further supported by the observation of reduced phagocytosis in the human retinal cell model following treatment with AZ14145845. Our study provides a viable, translational strategy to investigate the pre-clinical toxicity of MERTK inhibitors but is equally transferrable to novel chemotypes.
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Fagocitose/efeitos dos fármacos , Células Fotorreceptoras de Vertebrados/efeitos dos fármacos , c-Mer Tirosina Quinase/antagonistas & inibidores , Animais , Linhagem Celular , Feminino , Humanos , Masculino , Espectrometria de Massas , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Imagem Multimodal , Células Fotorreceptoras de Vertebrados/patologia , Ratos , Ratos Long-Evans , Ratos Wistar , Degeneração Retiniana/induzido quimicamente , Epitélio Pigmentado da Retina/metabolismo , Distribuição Tecidual , c-Mer Tirosina Quinase/genéticaRESUMO
Aberrant activity of the histone methyltransferase polycomb repressive complex 2 (PRC2) has been linked to several cancers, with small-molecule inhibitors of the catalytic subunit of the PRC2 enhancer of zeste homologue 2 (EZH2) being recently approved for the treatment of epithelioid sarcoma (ES) and follicular lymphoma (FL). Compounds binding to the EED subunit of PRC2 have recently emerged as allosteric inhibitors of PRC2 methyltransferase activity. In contrast to orthosteric inhibitors that target EZH2, small molecules that bind to EED retain their efficacy in EZH2 inhibitor-resistant cell lines. In this paper we disclose the discovery of potent and orally bioavailable EED ligands with good solubilities. The solubility of the EED ligands was optimized through a variety of design tactics, with the resulting compounds exhibiting in vivo efficacy in EZH2-driven tumors.
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Inibidores Enzimáticos/farmacologia , Complexo Repressor Polycomb 2/antagonistas & inibidores , Regulação Alostérica , Animais , Domínio Catalítico , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Proteína Potenciadora do Homólogo 2 de Zeste/química , Proteína Potenciadora do Homólogo 2 de Zeste/efeitos dos fármacos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacocinética , Compostos Heterocíclicos/química , Humanos , Ligantes , Complexo Repressor Polycomb 2/química , Ratos , Relação Estrutura-AtividadeRESUMO
The epidermal growth factor receptor (EGFR) harboring activating mutations is a clinically validated target in non-small-cell lung cancer, and a number of inhibitors of the EGFR tyrosine kinase domain, including osimertinib, have been approved for clinical use. Resistance to these therapies has emerged due to a variety of molecular events including the C797S mutation which renders third-generation C797-targeting covalent EGFR inhibitors considerably less potent against the target due to the loss of the key covalent-bond-forming residue. We describe the medicinal chemistry optimization of a biochemically potent but modestly cell-active, reversible EGFR inhibitor starting point with sub-optimal physicochemical properties. These studies culminated in the identification of compound 12 that showed improved cell potency, oral exposure, and in vivo activity in clinically relevant EGFR-mutant-driven disease models, including an Exon19 deletion/T790M/C797S triple-mutant mouse xenograft model.
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Antineoplásicos/uso terapêutico , Receptores ErbB/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Compostos Organofosforados/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Pirimidinas/uso terapêutico , Animais , Antineoplásicos/síntese química , Antineoplásicos/metabolismo , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Receptores ErbB/genética , Receptores ErbB/metabolismo , Feminino , Humanos , Camundongos Nus , Camundongos SCID , Mutação , Compostos Organofosforados/síntese química , Compostos Organofosforados/metabolismo , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/metabolismo , Pirimidinas/síntese química , Pirimidinas/metabolismo , Ratos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Free Energy Perturbation (FEP) calculations can provide high-confidence predictions of the interaction strength between a ligand and its protein target. We sought to explore a series of triazolopyrimidines which bind to the EED subunit of the PRC2 complex as potential anticancer therapeutics, using FEP calculations to inform compound design. Combining FEP predictions with a late-stage functionalisation (LSF) inspired synthetic approach allowed us to rapidly evaluate structural modifications in a previously unexplored region of the EED binding site. This approach generated a series of novel triazolopyrimidine EED ligands with improved physicochemical properties and which inhibit PRC2 methyltransferase activity in a cancer-relevant G401 cell line.
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Desenho de Fármacos , Inibidores Enzimáticos/farmacologia , Complexo Repressor Polycomb 2/antagonistas & inibidores , Purinas/farmacologia , Termodinâmica , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Humanos , Ligantes , Microssomos Hepáticos/química , Microssomos Hepáticos/metabolismo , Estrutura Molecular , Complexo Repressor Polycomb 2/metabolismo , Purinas/síntese química , Purinas/química , Teoria Quântica , Relação Estrutura-AtividadeRESUMO
INTRODUCTION: The OSCE is a sociomaterial assemblage-a meshing together of human and material components producing multiple effects. Materials matter because they shape candidate performance, with potentially calamitous career consequences if materials influence performance unjustly. Although the OSCE literature refers to materials, few papers study the sociomateriality of OSCEs. Therefore, we explored OSCE stakeholders' talk about sociomaterial assemblages to better understand their importance for candidate performance. METHODS: We conducted 15 focus groups with OSCE candidates (n = 42), examiners (n = 20) and simulated patients (n = 17) after an Australian postgraduate nursing OSCE. Sociomateriality informed our team-based framework analysis of data. RESULTS: Participants identified a multiplicity of OSCE materials (objects, technologies and spaces) thought to matter for candidate performance. Candidates' unfamiliarity with materials and missing or malfunctioning materials were reported to yield numerous negative impacts (eg cognitive overload, negative affect, time-wasting), thereby adversely affecting candidate performance. Both examiners and candidates made micro-adjustments to sociomaterial assemblages during the OSCE in order to make it work (eg candidates saying what they would do rather than doing it). Sometimes, such tinkering extended so far that sociomaterial assemblages were ruptured (eg examiners ignoring rubrics to help pass candidates), potentially influencing OSCE standardisation. DISCUSSION: Our novel empirical study extends previous conceptual work by illustrating wide-ranging sociomaterial assemblages influencing OSCE candidate performance. Further research is now needed employing sociomaterial approaches to further elucidate sociomaterial entanglements in diverse OSCEs. We encourage OSCE stakeholders to become more attuned to the productive nature of materials within all stages of OSCE design and implementation.
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Competência Clínica , Avaliação Educacional , Austrália , Humanos , Padrões de ReferênciaRESUMO
PURPOSE: Osimertinib is a potent and selective EGFR tyrosine kinase inhibitor (EGFR-TKI) of both sensitizing and T790M resistance mutations. To treat metastatic brain disease, blood-brain barrier (BBB) permeability is considered desirable for increasing clinical efficacy. EXPERIMENTAL DESIGN: We examined the level of brain penetration for 16 irreversible and reversible EGFR-TKIs using multiple in vitro and in vivo BBB preclinical models. RESULTS: In vitro osimertinib was the weakest substrate for human BBB efflux transporters (efflux ratio 3.2). In vivo rat free brain to free plasma ratios (Kpuu) show osimertinib has the most BBB penetrance (0.21), compared with the other TKIs (Kpuu ≤ 0.12). PET imaging in Cynomolgus macaques demonstrated osimertinib was the only TKI among those tested to achieve significant brain penetrance (C max %ID 1.5, brain/blood Kp 2.6). Desorption electrospray ionization mass spectroscopy images of brains from mouse PC9 macrometastases models showed osimertinib readily distributes across both healthy brain and tumor tissue. Comparison of osimertinib with the poorly BBB penetrant afatinib in a mouse PC9 model of subclinical brain metastases showed only osimertinib has a significant effect on rate of brain tumor growth. CONCLUSIONS: These preclinical studies indicate that osimertinib can achieve significant exposure in the brain compared with the other EGFR-TKIs tested and supports the ongoing clinical evaluation of osimertinib for the treatment of EGFR-mutant brain metastasis. This work also demonstrates the link between low in vitro transporter efflux ratios and increased brain penetrance in vivo supporting the use of in vitro transporter assays as an early screen in drug discovery.
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Acrilamidas/farmacocinética , Compostos de Anilina/farmacocinética , Barreira Hematoencefálica/metabolismo , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacocinética , Acrilamidas/administração & dosagem , Compostos de Anilina/administração & dosagem , Animais , Neoplasias Encefálicas/secundário , Cães , Receptores ErbB/antagonistas & inibidores , Humanos , Neoplasias Pulmonares/patologia , Macaca fascicularis , Células Madin Darby de Rim Canino , Masculino , Camundongos , Permeabilidade , Inibidores de Proteínas Quinases/administração & dosagem , Ratos , Distribuição Tecidual , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
B-cell lymphoma 6 (BCL6) inhibition is a promising mechanism for treating hematological cancers but high quality chemical probes are necessary to evaluate its therapeutic potential. Here we report potent BCL6 inhibitors that demonstrate cellular target engagement and exhibit exquisite selectivity for BCL6 based on mass spectrometry analyses following chemical proteomic pull down. Importantly, a proteolysis-targeting chimera (PROTAC) was also developed and shown to significantly degrade BCL6 in a number of diffuse large B-cell lymphoma (DLBCL) cell lines, but neither BCL6 inhibition nor degradation selectively induced marked phenotypic response. To investigate, we monitored PROTAC directed BCL6 degradation in DLBCL OCI-Ly1 cells by immunofluorescence and discovered a residual BCL6 population. Analysis of subcellular fractions also showed incomplete BCL6 degradation in all fractions despite having measurable PROTAC concentrations, together providing a rationale for the weak antiproliferative response seen with both BCL6 inhibitor and degrader. In summary, we have developed potent and selective BCL6 inhibitors and a BCL6 PROTAC that effectively degraded BCL6, but both modalities failed to induce a significant phenotypic response in DLBCL despite achieving cellular concentrations.
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Antineoplásicos/farmacologia , Proteínas Proto-Oncogênicas c-bcl-6/antagonistas & inibidores , Quinolonas/farmacologia , Talidomida/análogos & derivados , Talidomida/farmacologia , Proteínas Adaptadoras de Transdução de Sinal , Antineoplásicos/síntese química , Antineoplásicos/metabolismo , Linhagem Celular Tumoral , Células HEK293 , Humanos , Ligantes , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Peptídeo Hidrolases/metabolismo , Ligação Proteica , Proteólise , Proteínas Proto-Oncogênicas c-bcl-6/química , Proteínas Proto-Oncogênicas c-bcl-6/metabolismo , Quinolonas/síntese química , Quinolonas/metabolismo , Talidomida/síntese química , Talidomida/metabolismo , Ubiquitina-Proteína Ligases/metabolismoRESUMO
Silver nanostructures were fabricated by femtosecond laser-induced reduction of silver ions and the impact of solution chemistry on the fabricated structures was evaluated. By investigating the exact photochemistry of the nanofabrication solutions, which contained varying amounts of diamine silver ions, trisodium citrate, and n-lauroylsarcosine sodium, and optimizing the laser processing parameters, we fabricated two-dimensional silver pads with surface roughness values of 7 nm and stable 2.5-dimensional shell structures with heights up to 10 µm and aspect ratios of 20 in a ready manner. Moreover, thermal annealing of these structures afforded materials where the average resistivity value was only a factor of 4 greater than that of bulk silver. In this way, the work presented here provides for a methodology that can be used for laser direct fabrication of metal nanostructures for applications in plasmonics and micro- and nano-electronics.
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Inhibition of the protein-protein interaction between B-cell lymphoma 6 (BCL6) and corepressors has been implicated as a therapeutic target in diffuse large B-cell lymphoma (DLBCL) cancers and profiling of potent and selective BCL6 inhibitors are critical to test this hypothesis. We identified a pyrazolo[1,5-a]pyrimidine series of BCL6 binders from a fragment screen in parallel with a virtual screen. Using structure-based drug design, binding affinity was increased 100000-fold. This involved displacing crystallographic water, forming new ligand-protein interactions and a macrocyclization to favor the bioactive conformation of the ligands. Optimization for slow off-rate constant kinetics was conducted as well as improving selectivity against an off-target kinase, CK2. Potency in a cellular BCL6 assay was further optimized to afford highly selective probe molecules. Only weak antiproliferative effects were observed across a number of DLBCL lines and a multiple myeloma cell line without a clear relationship to BCL6 potency. As a result, we conclude that the BCL6 hypothesis in DLBCL cancer remains unproven.
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Mapas de Interação de Proteínas/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-6/metabolismo , Pirazóis/química , Pirazóis/farmacologia , Piridinas/química , Piridinas/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Desenho de Fármacos , Humanos , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Simulação de Acoplamento Molecular , Proteínas Proto-Oncogênicas c-bcl-6/antagonistas & inibidoresRESUMO
GPR120 agonists have therapeutic potential for the treatment of diabetes, but few selective agonists have been reported. We identified an indazole-6-phenylcyclopropylcarboxylic acid series of GPR120 agonists and conducted SAR studies to optimize GPR120 potency. Furthermore, we identified a (S,S)-cyclopropylcarboxylic acid structural motif which gave selectivity against GPR40. Good oral exposure was obtained with some compounds displaying unexpected high CNS penetration. Increased MDCK efflux was utilized to identify compounds such as 33 with lower CNS penetration, and activity in oral glucose tolerance studies was demonstrated. Differential activity was observed in GPR120 null and wild-type mice indicating that this effect operates through a mechanism involving GPR120 agonism.
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Ácidos Carboxílicos/química , Ácidos Carboxílicos/farmacologia , Indazóis/química , Indazóis/farmacologia , Receptores Acoplados a Proteínas G/agonistas , Animais , Glicemia/análise , Ácidos Carboxílicos/farmacocinética , Humanos , Indazóis/farmacocinética , Camundongos , Camundongos Endogâmicos C57BL , Modelos MolecularesRESUMO
Mature TGF-ß proteins are used in vivo to promote bone growth, combat obesity, reverse fibrosis and pulmonary arterial hypertension, and as potential rejuvenation factors. However, the serum half-life of this family of growth factors is short (â¼5 min), limiting their therapeutic potential. Because TGF-ß proteins are normally secreted from cells with their prodomains attached, we considered whether these molecules could extend the in vivo half-life and activity of their respective growth factors. Using activin A as a model ligand, we initially modified the cleavage site between the pro- and mature domains to ensure complete processing of the activin A precursor. Co-immunoprecipitation studies confirmed mature activin A is secreted from cells in a non-covalent complex with its prodomain, however, the affinity of this interaction is not sufficient to suppress activin A in vitro biological activity. The plasma clearance profiles of purified pro- and mature activin A were determined over a 4 h period in adult male rats. Both activin forms demonstrated a two-phase decay, with the half-life of pro-activin A (t1/2 fast = 12.5 min, slow = 31.0 min) being greater than that of mature activin A (t1/2 fast = 5.5 min, slow = 20.3 min). Both pro- and mature activin A induced significant increases in serum follicle stimulating hormone levels after 4 h, but no differences were observed in the relative in vivo bioactivities of the two activin isoforms. Increased serum half-life of activin A in the presence of its prodomain identifies a new means to increase the therapeutic effectiveness of TGF-ß proteins.
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Subunidades beta de Inibinas/química , Subunidades beta de Inibinas/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Animais , Hormônio Foliculoestimulante/sangue , Meia-Vida , Subunidades beta de Inibinas/farmacologia , Masculino , Modelos Moleculares , Isoformas de Proteínas/química , Isoformas de Proteínas/metabolismo , Isoformas de Proteínas/farmacologia , Estrutura Terciária de Proteína , RatosRESUMO
Ghrelin plays a major physiological role in the control of food intake, and inverse agonists of the ghrelin receptor (GHS-R1a) are widely considered to offer utility as antiobesity agents by lowering the set-point for hunger between meals. We identified an acylurea series of ghrelin modulators from high throughput screening and optimized binding affinity through structure-activity relationship studies. Furthermore, we identified specific substructural changes, which switched partial agonist activity to inverse agonist activity, and optimized physicochemical and DMPK properties to afford the non-CNS penetrant inverse agonist 22 (AZ-GHS-22) and the CNS penetrant inverse agonist 38 (AZ-GHS-38). Free feeding efficacy experiments showed that CNS exposure was necessary to obtain reduced food intake in mice, and it was demonstrated using GHS-R1a null and wild-type mice that this effect operates through a mechanism involving GHS-R1a.
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Agonismo Inverso de Drogas , Receptores de Grelina/agonistas , Receptores de Grelina/antagonistas & inibidores , Ureia/análogos & derivados , Ureia/farmacologia , Relação Dose-Resposta a Droga , Humanos , Modelos Moleculares , Estrutura Molecular , Receptores de Grelina/metabolismo , Relação Estrutura-Atividade , Ureia/químicaRESUMO
Enterovirus 71 (EV 71) is a causative agent of mild Hand Foot and Mouth Disease but is capable of causing severe complications in the CNS in young children. Reverse genetics technology is currently widely used to study the pathogenesis of the virus. The aim of this work was to determine and evaluate the factors which can contribute to infectivity of EV 71 RNA transcripts in vitro. Two strategies, overlapping RT-PCR and long distance RT-PCR, were employed to obtain the full-length genome cDNA clones of the virus. The length of the poly(A) tail and the presence of non-viral 3'-terminal sequences were studied in regard to their effects on infectivity of the in vitro RNA transcripts of EV 71 in cell culture. The data revealed that only cDNA clones obtained after long distance RT-PCR were infectious. No differences were observed in virus titres after transfection with in vitro RNA harbouring a poly(A) tail of 18 or 30 adenines in length, irrespective of the non-viral sequences at the 3'-terminus.
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DNA Complementar/genética , Enterovirus Humano A/genética , Doença de Mão, Pé e Boca/virologia , Genética Reversa/métodos , Animais , Chlorocebus aethiops , Enterovirus Humano A/fisiologia , Genoma Viral , RNA Mensageiro , Transfecção , Células VeroRESUMO
A computational method for predicting the likelihood of aromatic amines being active in the Ames test for mutagenicity was trialed on a set of aminopyrazoles. A virtual array of compounds was generated from the available sets of hydrazines and α-cyanoaldehydes (or ketones) and quantum mechanical calculations used to compute a probability of being active in the Ames test. The compounds selected for synthesis and testing were not based on the predictions and so spanned the range of predicted probabilities. The subsequently generated results of the Ames test were in good correspondence with the predictions and confirm this approach as a useful means of predicting likely mutagenic risk.
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Pirazóis/toxicidade , Teoria Quântica , Salmonella typhimurium/efeitos dos fármacos , Estrutura Molecular , Testes de Mutagenicidade , Pirazóis/química , Relação Estrutura-AtividadeRESUMO
There are some indications that seizure activity promotes the development of stroke-like episodes, or vice versa, in patients with mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (MELAS) syndrome or other syndromic mitochondrial disorders. A 41-year-old Caucasian female with MELAS syndrome, presenting with short stature, microcytic anaemia, increased blood-sedimentation rate, myopathy, hyper-gammaglobulinaemia, an iron-metabolism defect, migraine-like headaches, and stroke-like episodes, developed complex partial and generalised seizures at age 32 years. Valproic acid was ineffective but after switching to lamotrigine and lorazepam, she became seizure-free for five years and stroke-like episodes did not recur. Cerebral MRI initially showed enhanced gyral thickening and a non-enhanced T2-hyperintensity over the left parieto-temporo-occipital white matter and cortex and enhanced caudate heads. After two years without seizures, the non-enhanced hyperintense parieto-temporo-occipital lesion had disappeared, being attributed to consequent seizure control. The caudate heads, however, remained hyperintense throughout the observational period. This case indicates that adequate seizure control in a patient with MELAS syndrome may prevent the recurrence of stroke-like episodes and may result in the disappearance of stroke-like lesions on MRI.