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1.
Arch Sex Behav ; 50(4): 1225-1238, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34031779

RESUMO

We present the results of an investigation into the biographies, letters, and archives of approximately 50 well-known figures in Western intellectual and artistic history in the post-Enlightenment era. In this article, in the interest of space, we have limited our remarks to the biographies and partners of Virginia Woolf, Frida Kahlo, Max Weber, Edna St. Vincent Millay, William Moulton Marston, Erwin Schrodinger, and Victor Hugo. While some of these non-monogamous relationships are well known, some of the evidence of their existence has been ignored, misrecognized, or intentionally obscured. The results of this survey demonstrate that contemporary patterns of non-monogamies are deeply rooted in historical precedence. Our hope is that by outlining some of the themes in our historical findings we can help modern researchers better interpret their own quantitative and qualitative research. Additionally, we look particularly closely at relationships between metamours. A great deal of previous psychological and sexological research has focused on competitive behavior in sex and relationships, particularly competition between rivals. However, relatively little attention has been given to collaborative (or symbiotic) behavior. Our research has located a wealth of examples of metamours supporting one another in material, social, and psychological ways throughout their lives. Furthermore, we suggest that while our existing societal and social-scientific norms primarily focus on competitive sexual behaviors, much can be learnt from historically documented practices of consensual non-monogamy. These practices-however flawed-point to potentially emancipatory ways of living, loving and building relationships, families, and communities-as some contemporary research has demonstrated. Moreover, a future world might benefit from a turn to far more collaborative relationships-and such behavior is well within the realm of possibility.


Assuntos
Comportamento Sexual , Parceiros Sexuais , Humanos , Pesquisa Qualitativa , Normas Sociais , Inquéritos e Questionários
2.
Bioorg Med Chem ; 28(1): 115194, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31786008

RESUMO

Inhibition of BACE1 has become an important strategy in the quest for disease modifying agents to slow the progression of Alzheimer's disease. We previously reported the fragment-based discovery of LY2811376, the first BACE1 inhibitor reported to demonstrate robust reduction of human CSF Aß in a Phase I clinical trial. We also reported on the discovery of LY2886721, a potent BACE1 inhibitor that reached phase 2 clinical trials. Herein we describe the preparation and structure activity relationships (SAR) of a series of BACE1 inhibitors utilizing trans-cyclopropyl moieties as conformational constraints. The design, details of the stereochemically complex organic synthesis, and biological activity of these BACE1 inhibitors is described.


Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Ciclopropanos/farmacologia , Inibidores de Proteases/farmacologia , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Cristalografia por Raios X , Ciclopropanos/síntese química , Ciclopropanos/química , Relação Dose-Resposta a Droga , Humanos , Ligantes , Modelos Moleculares , Conformação Molecular , Inibidores de Proteases/síntese química , Inibidores de Proteases/química , Relação Estrutura-Atividade
3.
J Neurosci ; 35(3): 1199-210, 2015 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-25609634

RESUMO

BACE1 is a key protease controlling the formation of amyloid ß, a peptide hypothesized to play a significant role in the pathogenesis of Alzheimer's disease (AD). Therefore, the development of potent and selective inhibitors of BACE1 has been a focus of many drug discovery efforts in academia and industry. Herein, we report the nonclinical and early clinical development of LY2886721, a BACE1 active site inhibitor that reached phase 2 clinical trials in AD. LY2886721 has high selectivity against key off-target proteases, which efficiently translates in vitro activity into robust in vivo amyloid ß lowering in nonclinical animal models. Similar potent and persistent amyloid ß lowering was observed in plasma and lumbar CSF when single and multiple doses of LY2886721 were administered to healthy human subjects. Collectively, these data add support for BACE1 inhibition as an effective means of amyloid lowering and as an attractive target for potential disease modification therapy in AD.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Peptídeos beta-Amiloides/metabolismo , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Compostos Heterocíclicos com 2 Anéis/farmacologia , Ácidos Picolínicos/farmacologia , Inibidores de Proteases/farmacologia , Peptídeos beta-Amiloides/sangue , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Animais , Modelos Animais de Doenças , Cães , Compostos Heterocíclicos com 2 Anéis/farmacocinética , Compostos Heterocíclicos com 2 Anéis/uso terapêutico , Humanos , Camundongos , Ácidos Picolínicos/farmacocinética , Ácidos Picolínicos/uso terapêutico , Inibidores de Proteases/farmacocinética , Inibidores de Proteases/uso terapêutico
4.
Bioorg Med Chem ; 23(13): 3260-8, 2015 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-26001341

RESUMO

The BACE1 enzyme is a key target for Alzheimer's disease. During our BACE1 research efforts, fragment screening revealed that bicyclic thiazine 3 had low millimolar activity against BACE1. Analysis of the co-crystal structure of 3 suggested that potency could be increased through extension toward the S3 pocket and through conformational constraint of the thiazine core. Pursuit of S3-binding groups produced low micromolar inhibitor 6, which informed the S3-design for constrained analogs 7 and 8, themselves prepared via independent, multi-step synthetic routes. Biological characterization of BACE inhibitors 6-8 is described.


Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Compostos Bicíclicos com Pontes/síntese química , Inibidores de Proteases/síntese química , Tiazinas/síntese química , Secretases da Proteína Precursora do Amiloide/química , Secretases da Proteína Precursora do Amiloide/isolamento & purificação , Animais , Ácido Aspártico Endopeptidases/química , Ácido Aspártico Endopeptidases/isolamento & purificação , Química Encefálica , Compostos Bicíclicos com Pontes/química , Cristalografia por Raios X , Desenho de Fármacos , Humanos , Camundongos , Conformação Molecular , Simulação de Acoplamento Molecular , Inibidores de Proteases/química , Estereoisomerismo , Tiazinas/química
5.
Phys Chem Chem Phys ; 17(24): 15788-96, 2015 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-26017587

RESUMO

A new sensitizer motif for dye sensitized solar cells (DSSC) has been developed. A heteroaromatic moiety containing a pyrazine ring links two porphyrin chromophores to the metal oxide surface via two carboxylic acid attachment groups. A test DSSC sensitized with the new molecule was 3.5 times more efficient than a similar cell sensitized by a single porphyrin model compound. The open circuit photovoltage was increased by a modest factor of 1.3, but the photocurrent increased by a factor of 2.7. Most of the increase is attributed to a reduced rate of charge recombination of the charge separated state formed by photoinduced electron transfer from the excited sensitizer to the TiO2, although some of the difference is due to increased light absorption resulting from more dye on the photoanode. Increased light absorption due to the pyrazine-containing group may also play a role. The design illustrated here could also be used to link complementary sensitizers or antenna moieties in order to increase spectral coverage.

6.
HCA Healthc J Med ; 5(1): 39-43, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38560396

RESUMO

Introduction: Primary mucinous carcinoma of the thyroid is an exceedingly rare malignancy that is histologically similar to mucinous carcinoma of other sites. Accurate diagnosis is a challenging yet crucial component of clinical management for both patients and our understanding of this rare disease. Case Presentation: We report the case of a 69-year-old male patient with primary mucinous carcinoma of the thyroid. Microscopic examination of a biopsy specimen showed fibrous tissue, which was extensively and irregularly infiltrated by a cytologically malignant epithelial neoplasm showing glandular differentiation with mucin production. Immunohistochemistry demonstrated that tumor cells were positive for TTF1, thyroglobulin, CK7, and PAX8. Co-expression of TTF1 and PAX8 is most commonly seen in thyroid tumors. These findings support our diagnosis of mucinous carcinoma of thyroid origin, which is rare and highly aggressive. Conclusion: In this report, we present the only documented case of primary mucinous carcinoma of the thyroid reported in the United States in the last decade. The diagnosis of primary mucinous carcinoma of the thyroid can be challenging. Therefore, we discuss and detail the clinicopathologic tumor profile and provide more current, detailed histological criteria to assist in the diagnosis of this rare disease.

7.
Cureus ; 15(3): e36542, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37090400

RESUMO

Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic disorder, with variable clinical features, most commonly including café-au-lait macules and neurofibromas. The incidence of NF1 is approximately one in 3,000 individuals. Diffuse neurofibroma is the rarest subtype of neurofibromas. We present a case of a 39-year-old Micronesian male presenting with a substantially large and heavy overgrowth on his back, found to be consistent with diffuse neurofibroma on histopathologic examination. The patient also met the diagnostic criteria for NF1 based on clinical examination. Imaging showed the dermal and subcutaneous thickening without deep extension into the underlying fascial layer or muscles. A patient-centered, multidisciplinary approach was taken in the workup and management of this case. Our patient expressed disinterest in surgical interventions.

8.
Environ Toxicol Chem ; 42(11): 2478-2489, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37727898

RESUMO

Sea levels across the planet are rising, particularly along the eastern coast of the United States. Climate-induced sea level rise can result in the inundation and intrusion of seawater into freshwater drainages. This would alter salinity regimes and lead to the salinization of coastal freshwater ecosystems. Increased salinity levels in freshwater can negatively affect freshwater-dependent species, including native mussels belonging to the order Unionida, which are highly sensitive to changes in water quality. Sea salt is largely made up of sodium and chloride ions, forming sodium chloride, a known toxicant to freshwater mussels. However, sea salt is a mixture that also contains other major ions, including potassium, sulfate, calcium, strontium, and magnesium, among others. Freshwater mussels exposed to sea salt would be exposed to each of the sea salt ions at the same time, resulting in a mixture toxicity effect. The mixture toxicity of these ions on early life stages of freshwater mussels is largely unknown because most research to date has evaluated individual salt ions in relative isolation. Therefore, we conducted acute toxicity tests on early life stages (glochidia and juvenile) of three freshwater mussel species that inhabit Atlantic Slope drainages (nonsalinity-adapted Atlanticoncha ochracea, salinity-adapted A. ochracea, Sagittunio nasutus, and Utterbackiana implicata). Glochidia and juveniles of each species were exposed to a control and six concentrations of Instant Ocean® Sea Salt (IOSS), a synthetic sea salt that closely resembles the ionic composition of natural sea salt. Exposure concentrations were 1 part(s) per thousand (ppt), 2 ppt, 8.5 ppt, 12.5 ppt, 17 ppt, and 34 ppt. We calculated the median effect concentration (EC50) for each of the eight acute toxicity tests and found that glochidia were more sensitive than juveniles to IOSS. At hour 24 EC50s for the glochidia ranged from 0.38 to 3.6 ppt, with the most sensitive freshwater mussel being the nonsalinity-adapted A. ochracea, exhibiting an EC50 of 0.38 ppt (95% confidence interval [CI] 0.33-0.44). Juvenile freshwater mussels exhibited EC50s at hour 96 ranging from 5.0 to 10.4 ppt, with the least sensitive freshwater mussel being the nonsalinity-adapted A. ochracea, exhibiting an EC50 of 10.4 ppt (95% CI 9.1-12.0). Our results show that acute exposure to sea salt adversely affects freshwater mussel viability, particularly glochidia. This information can be used to enhance freshwater mussel conservation strategies in regions that are or will be impacted by climate-induced sea level rise and associated freshwater salinization. Environ Toxicol Chem 2023;42:2478-2489. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.


Assuntos
Bivalves , Unionidae , Poluentes Químicos da Água , Animais , Ecossistema , Elevação do Nível do Mar , Água Doce/química , Cloreto de Sódio/toxicidade , Cloretos , Alimentos Marinhos , Poluentes Químicos da Água/análise
9.
J Neurosci ; 31(46): 16507-16, 2011 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-22090477

RESUMO

According to the amyloid cascade hypothesis, cerebral deposition of amyloid-ß peptide (Aß) is critical for Alzheimer's disease (AD) pathogenesis. Aß generation is initiated when ß-secretase (BACE1) cleaves the amyloid precursor protein. For more than a decade, BACE1 has been a prime target for designing drugs to prevent or treat AD. However, development of such agents has turned out to be extremely challenging, with major hurdles in cell penetration, oral bioavailability/metabolic clearance, and brain access. Using a fragment-based chemistry strategy, we have generated LY2811376 [(S)-4-(2,4-difluoro-5-pyrimidin-5-yl-phenyl)-4-methyl-5,6-dihydro-4H-[1,3]thiazin-2-ylamine], the first orally available non-peptidic BACE1 inhibitor that produces profound Aß-lowering effects in animals. The biomarker changes obtained in preclinical animal models translate into man at doses of LY2811376 that were safe and well tolerated in healthy volunteers. Prominent and long-lasting Aß reductions in lumbar CSF were measured after oral dosing of 30 or 90 mg of LY2811376. This represents the first translation of BACE1-driven biomarker changes in CNS from preclinical animal models to man. Because of toxicology findings identified in longer-term preclinical studies, this compound is no longer progressing in clinical development. However, BACE1 remains a viable target because the adverse effects reported here were recapitulated in LY2811376-treated BACE1 KO mice and thus are unrelated to BACE1 inhibition. The magnitude and duration of central Aß reduction obtainable with BACE1 inhibition positions this protease as a tractable small-molecule target through which to test the amyloid hypothesis in man.


Assuntos
Doença de Alzheimer/líquido cefalorraquidiano , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Peptídeos beta-Amiloides/metabolismo , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Neurônios/efeitos dos fármacos , Adulto , Doença de Alzheimer/tratamento farmacológico , Secretases da Proteína Precursora do Amiloide/análise , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Precursor de Proteína beta-Amiloide/líquido cefalorraquidiano , Precursor de Proteína beta-Amiloide/genética , Análise de Variância , Animais , Ácido Aspártico Endopeptidases/análise , Células Cultivadas , Córtex Cerebral/citologia , Cristalografia/métodos , Modelos Animais de Doenças , Cães , Relação Dose-Resposta a Droga , Embrião de Mamíferos , Inibidores Enzimáticos/sangue , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Pessoa de Meia-Idade , Modelos Químicos , Mutação/genética , Fragmentos de Peptídeos/líquido cefalorraquidiano , Pirimidinas/farmacologia , Pirimidinas/uso terapêutico , Ratos , Ratos Sprague-Dawley , Tiazinas/farmacologia , Tiazinas/uso terapêutico , Fatores de Tempo , Adulto Jovem
10.
Plant Physiol ; 156(3): 1257-68, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21531898

RESUMO

Discovery of rare mutations in populations requires methods, such as TILLING (for Targeting Induced Local Lesions in Genomes), for processing and analyzing many individuals in parallel. Previous TILLING protocols employed enzymatic or physical discrimination of heteroduplexed from homoduplexed target DNA. Using mutant populations of rice (Oryza sativa) and wheat (Triticum durum), we developed a method based on Illumina sequencing of target genes amplified from multidimensionally pooled templates representing 768 individuals per experiment. Parallel processing of sequencing libraries was aided by unique tracer sequences and barcodes allowing flexibility in the number and pooling arrangement of targeted genes, species, and pooling scheme. Sequencing reads were processed and aligned to the reference to identify possible single-nucleotide changes, which were then evaluated for frequency, sequencing quality, intersection pattern in pools, and statistical relevance to produce a Bayesian score with an associated confidence threshold. Discovery was robust both in rice and wheat using either bidimensional or tridimensional pooling schemes. The method compared favorably with other molecular and computational approaches, providing high sensitivity and specificity.


Assuntos
Genoma de Planta/genética , Mutagênese/genética , Mutação/genética , Oryza/genética , Análise de Sequência de DNA/métodos , Triticum/genética , Genes de Plantas/genética , Genética Populacional , Projetos Piloto , Probabilidade , Moldes Genéticos
11.
Langmuir ; 28(22): 8348-58, 2012 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-22554348

RESUMO

A study of the interaction of four endoglucanases with amorphous cellulose films by neutron reflectometry (NR) and quartz crystal microbalance with dissipation monitoring (QCM-D) is reported. The endoglucanases include a mesophilic fungal endoglucanase (Cel45A from H. insolens), a processive endoglucanase from a marine bacterium (Cel5H from S. degradans ), and two from thermophilic bacteria (Cel9A from A. acidocaldarius and Cel5A from T. maritima ). The use of amorphous cellulose is motivated by the promise of ionic liquid pretreatment as a second generation technology that disrupts the native crystalline structure of cellulose. The endoglucanases displayed highly diverse behavior. Cel45A and Cel5H, which possess carbohydrate-binding modules (CBMs), penetrated and digested within the bulk of the films to a far greater extent than Cel9A and Cel5A, which lack CBMs. While both Cel45A and Cel5H were active within the bulk of the films, striking differences were observed. With Cel45A, substantial film expansion and interfacial broadening were observed, whereas for Cel5H the film thickness decreased with little interfacial broadening. These results are consistent with Cel45A digesting within the interior of cellulose chains as a classic endoglucanase, and Cel5H digesting predominantly at chain ends consistent with its designation as a processive endoglucanase.


Assuntos
Proteínas de Bactérias/química , Celulase/química , Celulose/química , Proteínas Fúngicas/química , Proteínas de Bactérias/metabolismo , Celulase/metabolismo , Celulose/metabolismo , Proteínas Fúngicas/metabolismo , Líquidos Iônicos/química , Difração de Nêutrons , Técnicas de Microbalança de Cristal de Quartzo , Propriedades de Superfície
12.
IDCases ; 29: e01589, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35942258

RESUMO

Mucormycosis is a rare opportunistic fungal infection with a high degree of morbidity and mortality. It classically presents with rapidly progressing, necrotic rhinocerebral mucocutaneous lesions in the setting of an immunocompromised host, especially with concomitant uncontrolled diabetes. We report the case of a 67-year-old man with well-controlled non-insulin dependent diabetes and brief steroid exposure who presented in sepsis with a tender posterior shoulder skin lesion. The initial lesion enlarged and progressed over several days, developing central areas of ecchymosis and bullae, with several other large lesions appearing at various distant sites. He also experienced an array of systemic symptoms, including fever, malaise, weakness, and acute encephalopathy. A diagnosis of mucor was made by histopathological examination of the initial skin lesion. Despite initiation of amphotericin B and aggressive surgical debridement including transfer to specialist tertiary burn center, the patient passed away less than a week after definitive diagnosis. This is a unique case of disseminated mucormycosis given his lack of chronic immunosuppression or uncontrolled diabetes, and with no risk factors for inoculation except for pacemaker placement 2 months prior to admission. The case highlights the importance of considering mucormycosis in the early differential diagnosis of rapidly progressing skin lesions, as rapid detection and treatment is critical to mitigate the deadly effects of this fast-moving fatal fungus. Moreover, the case serves as a testament to the unpredictable progression of disseminated disease, while also demonstrating an unusual potential mode of introduction and a rare but fatal consequence of prescribing corticosteroids in an infected host.

13.
Clin Case Rep ; 10(2): e05411, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35154727

RESUMO

Hydralazine-induced ANCA-associated vasculitis is a rare clinical entity, with complications including rapidly progressive glomerulonephritis, pulmonary hemorrhage, and pulmonary-renal syndrome. We present this case to highlight the clinical features that support this challenging diagnosis and to emphasize the importance of prompt recognition and aggressive intervention given its significant morbidity and mortality.

14.
Cureus ; 14(5): e25508, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35663682

RESUMO

Voriconazole therapy can be associated with hair loss, vision changes, and skin phototoxicity, but rarely is it associated with the development of skin cancer. We present a case of an immunocompetent 42-year-old Caucasian male with a past medical history significant for chronic pulmonary aspergillosis (CPA) and prior cutaneous squamous cell carcinoma (cSCC) of the left hand who arrived at our clinic for evaluation of an enlarging, non-tender left preauricular mass over the past six months. He had diffuse actinic changes and appeared older relative to his age. He had a fair complexion but was compliant with sun protection measures and minimized unnecessary ultraviolet (UV) light exposure. His left-sided facial mass was excised, and the final pathology was consistent with cSCC. His only home medication was oral voriconazole 200 mg once daily for six years for pulmonary aspergillosis. He was negative for human immunodeficiency virus (HIV) and had no history of prior transplant operations. This case highlights the importance of recognizing voriconazole as an independent risk factor in the development of cSCC, especially in patients on chronic therapy for aspergillosis.

15.
J Alzheimers Dis Rep ; 6(1): 1-15, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35243208

RESUMO

BACKGROUND: The development of beta-site amyloid-beta precursor protein cleaving enzyme (BACE) 1 inhibitors for the treatment of Alzheimer's disease requires optimization of inhibitor potency, selectivity, and brain penetration. Moreover, there is a need for low-dose compounds since liver toxicity was found with some BACE inhibitors. OBJECTIVE: To determine whether the high in vitro potency and robust pharmacodynamic effect of the BACE inhibitor LY3202626 observed in nonclinical species translated to humans. METHODS: The effect of LY3202626 versus vehicle on amyloid-ß (Aß) levels was evaluated in a series of in vitro assays, as well as in in vivo and multi-part clinical pharmacology studies. Aß levels were measured using analytical biochemistry assays in brain, plasma, and cerebrospinal fluid (CSF) of mice, dogs and humans. Nonclinical data were analyzed using an ANOVA followed by Tukey's post hoc test and clinical data used summary statistics. RESULTS: LY3202626 exhibited significant human BACE1 inhibition, with an IC50 of 0.615±0.101 nM in a fluorescence resonance energy transfer assay and an EC50 of 0.275±0.176 nM for lowering Aß1-40 and 0.228±0.244 nM for Aß1-42 in PDAPP neuronal cultures. In dogs, CSF Aß1hboxx concentrations were significantly reduced by ∼80% at 9 hours following a 1.5 mg/kg dose. In humans, CSF Aß1-42 was reduced by 73.1±7.96 % following administration of 6 mg QD. LY3202626 was found to freely cross the blood-brain barrier in dogs and humans. CONCLUSION: LY3202626 is a potent BACE1 inhibitor with high blood-brain barrier permeability. The favorable safety and pharmacokinetic/pharmacodynamic profile of LY3202626 supports further clinical development.

16.
PLoS Biol ; 6(12): 2707-20, 2008 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-19071961

RESUMO

The molecular mechanisms underlying lethality of F1 hybrids between diverged parents are one target of speciation research. Crosses between diploid and tetraploid individuals of the same genotype can result in F1 lethality, and this dosage-sensitive incompatibility plays a role in polyploid speciation. We have identified variation in F1 lethality in interploidy crosses of Arabidopsis thaliana and determined the genetic architecture of the maternally expressed variation via QTL mapping. A single large-effect QTL, DR. STRANGELOVE 1 (DSL1), was identified as well as two QTL with epistatic relationships to DSL1. DSL1 affects the rate of postzygotic lethality via expression in the maternal sporophyte. Fine mapping placed DSL1 in an interval encoding the maternal effect transcription factor TTG2. Maternal parents carrying loss-of-function mutations in TTG2 suppressed the F1 lethality caused by paternal excess interploidy crosses. The frequency of cellularization in the endosperm was similarly affected by both natural variation and ttg2 loss-of-function mutants. The simple genetic basis of the natural variation and effects of single-gene mutations suggests that F1 lethality in polyploids could evolve rapidly. Furthermore, the role of the sporophytically active TTG2 gene in interploidy crosses indicates that the developmental programming of the mother regulates the viability of interploidy hybrid offspring.


Assuntos
Proteínas de Arabidopsis/fisiologia , Arabidopsis/genética , Fatores de Transcrição/fisiologia , Proteínas de Arabidopsis/genética , Cruzamentos Genéticos , Diploide , Genes de Plantas/fisiologia , Hibridização Genética/genética , Microscopia Confocal , Poliploidia , Locos de Características Quantitativas , Sementes/fisiologia , Fatores de Transcrição/genética
17.
J Ind Microbiol Biotechnol ; 38(8): 1117-25, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21327449

RESUMO

Saccharophagus degradans 2-40 is a marine gamma proteobacterium that can produce polyhydroxyalkanoates from lignocellulosic biomass using a complex cellulolytic system. This bacterium has been annotated to express three surface-associated ß-glucosidases (Bgl3C, Ced3A, and Ced3B), two cytoplasmic ß-glucosidases (Bgl1A and Bgl1B), and unusual for an aerobic bacterium, two cytoplasmic cellobiose/cellodextrin phosphorylases (Cep94A and Cep94B). Expression of the genes for each of the above enzymes was induced when cells were transferred into a medium containing Avicel as the major carbon source except for Bgl1B. Both hydrolytic and phosphorolytic degradation of cellobiose by crude cell lysates obtained from cellulose-grown cells were demonstrated and all of these activities were cell-associated. With the exception of Cep94B, each purified enzyme exhibited their annotated activity upon cloning and expression in E. coli. The five ß-glucosidases hydrolyzed a variety of glucose derivatives containing ß-1, (2, 4, or 6) linkages but did not act on any α-linked glucose derivatives. All but one ß-glucosidases exhibited transglycosylation activity consistent with the formation of an enzyme-substrate intermediate. The biochemistry and expression of these cellobiases indicate that external hydrolysis by surface-associated ß-glucosidases coupled with internal hydrolysis and phosphorolysis are all involved in the metabolism of cellobiose by this bacterium.


Assuntos
Alteromonadaceae/metabolismo , Celobiose/metabolismo , Alteromonadaceae/genética , Bactérias Aeróbias/metabolismo , Celulose/metabolismo , Celulose 1,4-beta-Celobiosidase/metabolismo , Escherichia coli/genética , Glucosiltransferases/genética , Glucosiltransferases/metabolismo , Hidrólise , Fosforilação , beta-Glucosidase/genética , beta-Glucosidase/metabolismo
18.
PLoS One ; 16(5): e0251284, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34019549

RESUMO

A healthy democracy requires trust that people can be impartial in important truth-seeking institutions including journalism, justice, and science. Recently some U.S. elites have adopted alarmingly extreme rhetoric against truth-seekers, denouncing mainstream journalism as fake news, criminal investigations as partisan witch-hunts, climate science as a hoax, and career civil servants as a deep state conspiracy. In response, some news organizations have taken the unusual step of publishing op/eds defending these institutions. Two experiments tested effects of such op/eds. In study 1, participants spent twelve days using a purpose-built news portal containing real, timely news with random assignment to the availability of real, timely op/eds defending impartiality of truth-seekers. These op/eds increased trust in truth-seeking institutions and increased the belief that people can serve as impartial professionals. Study 2 replicated this with a laboratory experiment assigning video op/ed exposure instead of text op/ed availability while adding several outcomes.


Assuntos
Justiça Social/psicologia , Adulto , Enganação , Feminino , Humanos , Masculino , Política , Confiança , Estados Unidos
19.
J Med Chem ; 64(12): 8076-8100, 2021 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-34081466

RESUMO

The beta-site APP cleaving enzyme 1, known as BACE1, has been a widely pursued Alzheimer's disease drug target owing to its critical role in the production of amyloid-beta. We have previously reported the clinical development of LY2811376 and LY2886721. LY2811376 advanced to Phase I before development was terminated due to nonclinical retinal toxicity. LY2886721 advanced to Phase II, but development was halted due to abnormally elevated liver enzymes. Herein, we report the discovery and clinical development of LY3202626, a highly potent, CNS-penetrant, and low-dose BACE inhibitor, which successfully addressed these key development challenges.


Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Compostos Heterocíclicos com 2 Anéis/farmacologia , Inibidores de Proteases/farmacologia , Pirazinas/farmacologia , Pirróis/farmacologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Ácido Aspártico Endopeptidases/metabolismo , Barreira Hematoencefálica/fisiologia , Encéfalo/metabolismo , Cristalografia por Raios X , Cães , Estabilidade de Medicamentos , Compostos Heterocíclicos com 2 Anéis/síntese química , Compostos Heterocíclicos com 2 Anéis/farmacocinética , Humanos , Células Madin Darby de Rim Canino , Masculino , Camundongos , Microssomos Hepáticos/metabolismo , Estrutura Molecular , Inibidores de Proteases/síntese química , Inibidores de Proteases/metabolismo , Inibidores de Proteases/farmacocinética , Ligação Proteica , Pirazinas/síntese química , Pirazinas/farmacocinética , Pirróis/síntese química , Pirróis/farmacocinética , Ratos , Relação Estrutura-Atividade
20.
J Med Chem ; 64(7): 3697-3706, 2021 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-33591753

RESUMO

Protein arginine methyltransferase 6 (PRMT6) catalyzes monomethylation and asymmetric dimethylation of arginine residues in various proteins, plays important roles in biological processes, and is associated with multiple cancers. To date, a highly selective PRMT6 inhibitor has not been reported. Here we report the discovery and characterization of a first-in-class, highly selective allosteric inhibitor of PRMT6, (R)-2 (SGC6870). (R)-2 is a potent PRMT6 inhibitor (IC50 = 77 ± 6 nM) with outstanding selectivity for PRMT6 over a broad panel of other methyltransferases and nonepigenetic targets. Notably, the crystal structure of the PRMT6-(R)-2 complex and kinetic studies revealed (R)-2 binds a unique, induced allosteric pocket. Additionally, (R)-2 engages PRMT6 and potently inhibits its methyltransferase activity in cells. Moreover, (R)-2's enantiomer, (S)-2 (SGC6870N), is inactive against PRMT6 and can be utilized as a negative control. Collectively, (R)-2 is a well-characterized PRMT6 chemical probe and a valuable tool for further investigating PRMT6 functions in health and disease.


Assuntos
Benzodiazepinonas/farmacologia , Inibidores Enzimáticos/farmacologia , Proteínas Nucleares/antagonistas & inibidores , Proteína-Arginina N-Metiltransferases/antagonistas & inibidores , Regulação Alostérica , Sítio Alostérico , Benzodiazepinonas/síntese química , Benzodiazepinonas/metabolismo , Cristalografia por Raios X , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/metabolismo , Células HEK293 , Humanos , Proteínas Nucleares/metabolismo , Ligação Proteica , Proteína-Arginina N-Metiltransferases/metabolismo , Estereoisomerismo
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