RESUMO
An atom economic method demonstrates the involvement of noncovalent interaction via hydrogen or halogen bonding interaction in triggering paired electrolysis for the group transfer reactions. Specifically, this method demonstrated the bromination of several aromatic and heteroaromatic compounds through the activation of the C(sp3)-Br bond of organic-bromo derivatives on demand. This electrochemical protocol is mild, and mostly no additional electrolyte is needed, which makes the workup process straightforward. Unlike the existing regioselective monobromination methods, this work utilizes a relatively small amount (1.2 equiv) of bromine surrogates that releases bromine on demand under the electrochemical condition and after completion of the reaction generates acetophenone as a useful byproduct. Green metrics indicate this protocol has a very good atom efficiency with an E-factor of 26.86 kg of waste/1 kg of product. In addition to the scale-up process, this strategy could be extended to the transfer of chlorine and thioaryl units. An extensive mechanistic study is accomplished to validate the hypothesis of noncovalent interaction using computational, spectroscopic, and cyclic voltammetry studies. Finally, the applicability of this newly developed nonbonding interaction to trigger paired electrolysis was extended to the chemoselective debromination of several dihalo organic compounds.
RESUMO
Thioesters play a crucial role in biological systems and serve as important building blocks for organic synthesis. Herein, Eosin Y and TBHP mediated photochemical cross dehydrogenative coupling (PCDC) between feedstock aldehydes and thiols has been described at room temperature to synthesize thioesters. This thioesterification protocol proceeds smoothly to give the desired products in good to excellent yields by the suitable PCDC of both alkyl/aryl- aldehydes with a variety of alkyl/aryl-thiols and generates water and tBuOH as green byproducts. This method is also found to be scalable with good efficiency. Mechanistic investigations reveal that under this photochemical condition, the formation of acyl radical can be achieved from aldehyde. This acyl radical was further intercepted with an intermediate disulfide, generated in situ via the dehydrogenation of thiol to give the desired thioester. Moreover, disulfides, which are relatively easier to handle, also provided good to excellent yields in the optimized reaction condition. This protocol was further extended toward the more challenging direct transformation of alcohols to thioesters.
RESUMO
The development of versatile and mild methodologies for C-N bond construction has always been a hot topic of interest in synthetic organic chemistry. In recent years, electrochemistry has emerged as a promising green and sustainable environmentally benign approach to carry out these transformations under mild conditions utilizing electrons as oxidizing/reducing agents. The current state-of-the-art in combining electrocatalysis with transition metal catalysis has gained significant attention. This hybrid synthetic methodology has increasingly become a common tool and offers many potential advantages compared to direct electrolysis. This review comprehensively highlights recent developments in the merging of transition metal catalysis in electro-organic synthesis for the facile construction of C-N bonds. In this review major emphasis is given to mechanistic investigations and their synthetic applications of this hybrid catalysis.
RESUMO
OBJECTIVE: To describe disease course, histopathology, and outcomes for infants with atypical presentations of alveolar capillary dysplasia with misalignment of the pulmonary veins (ACDMPV) who underwent bilateral lung transplantation. STUDY DESIGN: We reviewed clinical history, diagnostic studies, explant histology, genetic sequence results, and post-transplant course for 6 infants with atypical ACDMPV who underwent bilateral lung transplantation at St. Louis Children's Hospital. We compared their histology with infants with classic ACDMPV and compared their outcomes with infants transplanted for other indications. RESULTS: In contrast with neonates with classic ACDPMV who present with severe hypoxemia and refractory pulmonary hypertension within hours of birth, none of the infants with atypical ACDMPV presented with progressive neonatal respiratory failure. Three infants had mild neonatal respiratory distress and received nasal cannula oxygen. Three other infants had no respiratory symptoms at birth and presented with hypoxemia and pulmonary hypertension at 2-3 months of age. Bilateral lung transplantation was performed at 4-20 months of age. Unlike in classic ACDMPV, histopathologic findings were not distributed uniformly and were not diffuse. Three subjects had apparent nonmosaic genetic defects involving FOXF1. Two infants had extrapulmonary anomalies (posterior urethral valves, inguinal hernia). Three transplanted children are alive at 5-16 years of age, similar to outcomes for infants transplanted for other indications. Lung explants from infants with atypical ACDMPV demonstrated diagnostic but nonuniform histopathologic findings. CONCLUSIONS: The 1- and 5-year survival rates for infants with atypical ACDMPV are similar to infants transplanted for other indications. Given the clinical and histopathologic spectra, ACDMPV should be considered in infants with hypoxemia and pulmonary hypertension, even beyond the newborn period.
Assuntos
Transplante de Pulmão/métodos , Síndrome da Persistência do Padrão de Circulação Fetal/diagnóstico , Alvéolos Pulmonares/anormalidades , Feminino , Fatores de Transcrição Forkhead/genética , Humanos , Lactente , Recém-Nascido , Pulmão/patologia , Masculino , Mutação , Síndrome da Persistência do Padrão de Circulação Fetal/complicações , Síndrome da Persistência do Padrão de Circulação Fetal/cirurgia , Alvéolos Pulmonares/cirurgia , Veias Pulmonares/anormalidades , Taxa de SobrevidaRESUMO
An unanticipated and tremendous amount of the noncoding sequence of the human genome is transcribed. Long noncoding RNAs (lncRNAs) constitute a significant fraction of non-protein-coding transcripts; however, their functions remain enigmatic. We demonstrate that deletions of a small noncoding differentially methylated region at 16q24.1, including lncRNA genes, cause a lethal lung developmental disorder, alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV), with parent-of-origin effects. We identify overlapping deletions 250 kb upstream of FOXF1 in nine patients with ACD/MPV that arose de novo specifically on the maternally inherited chromosome and delete lung-specific lncRNA genes. These deletions define a distant cis-regulatory region that harbors, besides lncRNA genes, also a differentially methylated CpG island, binds GLI2 depending on the methylation status of this CpG island, and physically interacts with and up-regulates the FOXF1 promoter. We suggest that lung-transcribed 16q24.1 lncRNAs may contribute to long-range regulation of FOXF1 by GLI2 and other transcription factors. Perturbation of lncRNA-mediated chromatin interactions may, in general, be responsible for position effect phenomena and potentially cause many disorders of human development.
Assuntos
Variações do Número de Cópias de DNA , Metilação de DNA , Síndrome da Persistência do Padrão de Circulação Fetal/genética , RNA Longo não Codificante/genética , Cromatina/metabolismo , Cromossomos Humanos Par 16/genética , Ilhas de CpG , Elementos Facilitadores Genéticos , Evolução Fatal , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Regulação da Expressão Gênica , Impressão Genômica , Células HEK293 , Humanos , Recém-Nascido , Fatores de Transcrição Kruppel-Like/metabolismo , Proteínas Nucleares/metabolismo , Síndrome da Persistência do Padrão de Circulação Fetal/diagnóstico , Regiões Promotoras Genéticas , RNA Longo não Codificante/metabolismo , Deleção de Sequência , Transcrição Gênica , Proteína Gli2 com Dedos de ZincoRESUMO
Position effects due to disruption of distant cis-regulatory regions have been reported for over 40 human gene loci; however, the underlying mechanisms of long-range gene regulation remain largely unknown. We report on two patients with alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV) caused by overlapping genomic deletions that included a distant FOXF1 transcriptional enhancer mapping 0.3 Mb upstream to FOXF1 on 16q24.1. In one patient with atypical late-onset ACDMPV, a â¼1.5 Mb deletion removed the proximal 43% of this enhancer, leaving the lung-specific long non-coding RNA (lncRNA) gene LINC01081 intact. In the second patient with severe neonatal-onset ACDMPV, an overlapping â¼194 kb deletion disrupted LINC01081. Both deletions arose de novo on maternal copy of the chromosome 16, supporting the notion that FOXF1 is paternally imprinted in the human lungs. RNAi-mediated knock-down of LINC01081 in normal fetal lung fibroblasts showed that this lncRNA positively regulates FOXF1 transcript level, further indicating that decrease in LINC01081 expression can contribute to development of ACDMPV.
Assuntos
Elementos Facilitadores Genéticos , Fatores de Transcrição Forkhead/genética , Síndrome da Persistência do Padrão de Circulação Fetal/genética , RNA Longo não Codificante/genética , Adulto , Biópsia , Hibridização Genômica Comparativa , Análise Mutacional de DNA , Feminino , Expressão Gênica , Humanos , Recém-Nascido , Pulmão/diagnóstico por imagem , Pulmão/patologia , Masculino , Interferência de RNA , RNA Mensageiro/genética , Radiografia , Deleção de SequênciaRESUMO
Herein, we have developed a new class of organic photocatalysts that can mimic transition metals for several oxidative and reductive organic cross-coupling transformations. Due to its wide potential window in both the oxidation and reduction ranges, cinnoline exhibits dual catalytic activity under visible light illumination, acting as both a photoreductant and photooxidant.
RESUMO
Alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV) is a rare and lethal developmental disorder of the lung defined by a constellation of characteristic histopathological features. Nonpulmonary anomalies involving organs of gastrointestinal, cardiovascular, and genitourinary systems have been identified in approximately 80% of patients with ACD/MPV. We have collected DNA and pathological samples from more than 90 infants with ACD/MPV and their family members. Since the publication of our initial report of four point mutations and 10 deletions, we have identified an additional 38 novel nonsynonymous mutations of FOXF1 (nine nonsense, seven frameshift, one inframe deletion, 20 missense, and one no stop). This report represents an up to date list of all known FOXF1 mutations to the best of our knowledge. Majority of the cases are sporadic. We report four familial cases of which three show maternal inheritance, consistent with paternal imprinting of the gene. Twenty five mutations (60%) are located within the putative DNA-binding domain, indicating its plausible role in FOXF1 function. Five mutations map to the second exon. We identified two additional genic and eight genomic deletions upstream to FOXF1. These results corroborate and extend our previous observations and further establish involvement of FOXF1 in ACD/MPV and lung organogenesis.
Assuntos
Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Mutação , Síndrome da Persistência do Padrão de Circulação Fetal/genética , Síndrome da Persistência do Padrão de Circulação Fetal/metabolismo , Domínios e Motivos de Interação entre Proteínas/genética , Sequência de Aminoácidos , Mapeamento Cromossômico , Bases de Dados Genéticas , Feminino , Fatores de Transcrição Forkhead/química , Dosagem de Genes , Ordem dos Genes , Humanos , Lactente , Recém-Nascido , Masculino , Dados de Sequência Molecular , Fases de Leitura Aberta , Síndrome da Persistência do Padrão de Circulação Fetal/mortalidade , Síndrome da Persistência do Padrão de Circulação Fetal/patologia , Alinhamento de SequênciaRESUMO
By revealing the robust photooxidant properties of phenalenyl-based organic Lewis acid, we have introduced this moiety as an effective organophotocatalyst for the oxidative azolation of unactivated and feedstock arenes. In addition to its tolerance for various functional groups and scalability, this photocatalyst was shown to be promising for the defluorinative azolation of fluoroarenes.
RESUMO
Alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV) is a rare, neonatally lethal developmental disorder of the lung with defining histologic abnormalities typically associated with multiple congenital anomalies (MCA). Using array CGH analysis, we have identified six overlapping microdeletions encompassing the FOX transcription factor gene cluster in chromosome 16q24.1q24.2 in patients with ACD/MPV and MCA. Subsequently, we have identified four different heterozygous mutations (frameshift, nonsense, and no-stop) in the candidate FOXF1 gene in unrelated patients with sporadic ACD/MPV and MCA. Custom-designed, high-resolution microarray analysis of additional ACD/MPV samples revealed one microdeletion harboring FOXF1 and two distinct microdeletions upstream of FOXF1, implicating a position effect. DNA sequence analysis revealed that in six of nine deletions, both breakpoints occurred in the portions of Alu elements showing eight to 43 base pairs of perfect microhomology, suggesting replication error Microhomology-Mediated Break-Induced Replication (MMBIR)/Fork Stalling and Template Switching (FoSTeS) as a mechanism of their formation. In contrast to the association of point mutations in FOXF1 with bowel malrotation, microdeletions of FOXF1 were associated with hypoplastic left heart syndrome and gastrointestinal atresias, probably due to haploinsufficiency for the neighboring FOXC2 and FOXL1 genes. These differences reveal the phenotypic consequences of gene alterations in cis.
Assuntos
Displasia Broncopulmonar/genética , Cromossomos Humanos Par 16/genética , Fatores de Transcrição Forkhead/genética , Deleção de Genes , Inativação Gênica , Mutação/genética , Alvéolos Pulmonares/patologia , Anormalidades Múltiplas/genética , Capilares/anormalidades , Pré-Escolar , Mapeamento Cromossômico , Doxorrubicina/análogos & derivados , Feminino , Humanos , Hibridização in Situ Fluorescente , Lactente , Recém-Nascido , Masculino , Alvéolos Pulmonares/irrigação sanguínea , Veias Pulmonares/anormalidadesRESUMO
Here we report Eosin Y as a bimodular catalyst for Minisci-type acylation reactions. The formation of organic exciplexes between photoexcited Eosin Y and N-heteroarenes was found to be a stabilizing factor for photoacid catalysis under optimized conditions. Spectroscopic investigations such as steady state fluorescence quenching and dynamic lifetime quenching experiments were employed to better understand the role of Eosin Y as both a photoredox catalyst and a photoacid. Feedstock aldehydes were employed as acyl radical precursors for engaging in C-C bond formation reactions with a variety of nitrogen containing heterocycles.
RESUMO
The development of stoichiometric oxidant-free regioselective annulation protocol is a challenging aspect in organic synthesis. Herein, we disclose electricity as a greener oxidant for the C-H/N-H annulation to construct cinnolines using rhodium(III) catalyst under mild conditions. A detailed mechanistic investigation revealed the possibility of both Rh(III/I) and Rh(III/IV) catalytic cycles for the formation of annulated product. Exclusive regioselectivity, diverse substrate scope, and commercially available cheap graphite electrodes are key features of this protocol.
RESUMO
Growth hormone is one of few pharmacologic agents known to augment milk production in humans. We hypothesized that recombinant human GH (rhGH) increases the expression of cell proliferation and milk protein synthesis genes. Sequential milk and blood samples collected over four days were obtained from five normal lactating women. Following 24 h of baseline milk and blood sampling, rhGH (0.1 mg/kg/day) was administered subcutaneously once daily for 3 days. Gene expression changes were determined by microarray studies utilizing milk fat globule RNA isolated from each milk sample. Following rhGH administration, DNA synthesis and cell cycle genes were induced, while no significant changes were observed in the expression of milk synthesis genes. Expression of glycolysis and citric acid cycle genes were increased by day 4 compared with day 1, while lipid synthesis genes displayed a circadian-like pattern. Cell cycle gene upregulation occurred after a lag of â¼2 days, likely explaining the failure to increase milk production after only 3 days of rhGH treatment. We conclude that rhGH induces expression of cellular proliferation and metabolism genes but does not induce milk protein gene expression, as potential mechanisms for increasing milk production and could account for the known effect of rhGH to increase milk production following 7-10 days.
Assuntos
Glicolipídeos/análise , Glicoproteínas/análise , Hormônio do Crescimento Humano/administração & dosagem , Lactação/efeitos dos fármacos , Lactação/genética , Proteínas do Leite/efeitos dos fármacos , Proteínas do Leite/genética , Adulto , Proteínas de Ciclo Celular/sangue , Proteínas de Ciclo Celular/efeitos dos fármacos , Proteínas de Ciclo Celular/metabolismo , Proliferação de Células/efeitos dos fármacos , Feminino , Expressão Gênica/efeitos dos fármacos , Humanos , Fator de Crescimento Insulin-Like I/efeitos dos fármacos , Fator de Crescimento Insulin-Like I/metabolismo , Gotículas Lipídicas , Análise em Microsséries/métodos , Proteínas Recombinantes/administração & dosagemRESUMO
Embracing sustainable green methodologies and techniques in chemical transformations has always been in the limelight to the synthetic community. Electrosynthesis has emerged as a powerful, sustainable synthetic tool for molecular synthesis exploiting inexpensive electricity in place of sacrificial chemical oxidizing/reducing reagents. Herein, recent advances in the incorporation of transition metal-free redox mediators in electrosynthesis for the construction of C-N bonds are outlined. Furthermore, conjugation of this strategy with flow catalysis allows easy scale up of the synthesis of molecular assembly. This comprehensive Review provides an overview of metal-free mediated electro-construction of C-N bonds, focusing on the reaction mechanisms involved and its synthetic applications.
RESUMO
The molecular physiology underlying human milk production is largely unknown because of limitations in obtaining tissue samples. Determining gene expression in normal lactating women would be a potential step toward understanding why some women struggle with or fail at breastfeeding their infants. Recently, we demonstrated the utility of RNA obtained from breast milk fat globule (MFG) to detect mammary epithelial cell (MEC)-specific gene expression. We used MFG RNA to determine the gene expression profile of human MEC during lactation. Microarray studies were performed using Human Ref-8 BeadChip arrays (Illumina). MFG RNA was collected every 3 h for 24 h from five healthy, exclusively breastfeeding women. We determined that 14,070 transcripts were expressed and represented the MFG transcriptome. According to GeneSpring GX 9, 156 ontology terms were enriched (corrected P < 0.05), which include cellular (n = 3,379 genes) and metabolic (n = 2,656) processes as the most significantly enriched biological process terms. The top networks and pathways were associated primarily with cellular activities most likely involved with milk synthesis. Multiple sampling over 24 h enabled us to demonstrate core circadian clock gene expression and the periodicity of 1,029 genes (7%) enriched for molecular functions involved in cell development, growth, proliferation, and cell morphology. In addition, we found that the MFG transcriptome was comparable to the metabolic gene expression profile described for the lactating mouse mammary gland. This paper is the first to describe the MFG transcriptome in sequential human samples over a 24 h period, providing valuable insights into gene expression in the human MEC.
Assuntos
Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Glicolipídeos/genética , Glicoproteínas/genética , Lactação/genética , Glândulas Mamárias Humanas/metabolismo , Adolescente , Adulto , Animais , Aleitamento Materno , Análise por Conglomerados , Feminino , Redes Reguladoras de Genes , Humanos , Gotículas Lipídicas , Camundongos , Prolactina/sangue , Software , Fatores de TempoRESUMO
Experiments were conducted to identify blast-resistant fragrant genotypes for the development of a durable blast-resistant rice variety during years 2012-2013. The results indicate that out of 140 test materials including 114 fragrant germplasms, 25 differential varieties (DVs) harbouring 23 blast-resistant genes, only 16 fragrant rice germplasms showed comparatively better performance against a virulent isolate of blast disease. The reaction pattern of single-spore isolate of Magnaporthe oryzae to differential varieties showed that Pish, Pi9, Pita-2 and Pita are the effective blast-resistant genes against the tested blast isolates in Bangladesh. The DNA markers profiles of selected 16 rice germplasms indicated that genotype Chinigura contained Pish, Pi9 and Pita genes; on the other hand, both BRRI dhan50 and Bawaibhog contained Pish and Pita genes in their genetic background. Genotypes Jirakatari, BR5, and Gopalbhog possessed Pish gene, while Uknimodhu, Deshikatari, Radhunipagol, Kalijira (3), Chinikanai each contained the Pita gene only. There are some materials that did not contain any target gene(s) in their genetic background, but proved resistant in pathogenicity tests. This information provided valuable genetic information for breeders to develop durable blast-resistant fragrant or aromatic rice varieties in Bangladesh.
Assuntos
Resistência à Doença/genética , Resistência à Doença/fisiologia , Micoses/microbiologia , Oryza/genética , Oryza/fisiologia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , DNA de Plantas/genética , Genes de Plantas/genética , Marcadores Genéticos , Magnaporthe/fisiologia , Fenótipo , Especificidade da EspécieRESUMO
A critical investigation was conducted to find out the effect of neck blast disease on yield-contributing characters, and seed quality traits of aromatic rice in Bangladesh. Both healthy and neck-blast-infected panicles of three aromatic rice cultivars (high-yielding and local) were collected and investigated at Plant Pathology Division, Bangladesh Rice Research Institute (BRRI), Gazipur, Bangladesh. All of the tested varieties were highly susceptible to neck blast disease under natural conditions, though no leaf blast symptoms appear on leaves. Neck blast disease increased grain sterility percentages, reduced grain size, yield and quality traits of seeds. The degrees of yield and seed quality reduction depended on disease severity and variety's genetic make-up. Unfilled grains were the main source of seed-borne pathogen, especially for blast in the seed lot. Transmission of blast pathogen from neck (panicle base) to seed was very poor. These findings are important, especially concerning the seed certification programme in which seed lots are certified on the basis of field inspection. Finally, controlled experiments are needed to draw more critical conclusions.
Assuntos
Qualidade dos Alimentos , Oryza/crescimento & desenvolvimento , Oryza/microbiologia , Doenças das Plantas/microbiologia , Pyricularia grisea , Bangladesh , Folhas de Planta , Plântula/microbiologia , Sementes/anatomia & histologia , Sementes/microbiologiaRESUMO
Alveolar Capillary Dysplasia with Misalignment of Pulmonary Veins (ACDMPV) is a developmental disorder of the lungs, primarily affecting their vasculature. FOXF1 haploinsufficiency due to heterozygous genomic deletions and point mutations have been reported in most patients with ACDMPV. The majority of mice with heterozygous loss-of-function of Foxf1 exhibit neonatal lethality with evidence of pulmonary hemorrhage in some of them. By comparing transcriptomes of human ACDMPV lungs with control lungs using expression arrays, we found that several genes and pathways involved in lung development, angiogenesis, and in pulmonary hypertension development, were deregulated. Similar transcriptional changes were found in lungs of the postnatal day 0.5 Foxf1+/- mice when compared to their wildtype littermate controls; 14 genes, COL15A1, COL18A1, COL6A2, ESM1, FSCN1, GRINA, IGFBP3, IL1B, MALL, NOS3, RASL11B, MATN2, PRKCDBP, and SIRPA, were found common to both ACDMPV and Foxf1 heterozygous lungs. Our results advance knowledge toward understanding of the molecular mechanism of ACDMPV, lung development, and its vasculature pathology. These data may also be useful for understanding etiologies of other lung disorders, e.g. pulmonary hypertension, bronchopulmonary dysplasia, or cancer.
Assuntos
Fatores de Transcrição Forkhead/genética , Genes Letais , Pulmão/metabolismo , Síndrome da Persistência do Padrão de Circulação Fetal/genética , Alvéolos Pulmonares/anormalidades , Veias Pulmonares/metabolismo , Transcriptoma , Animais , Animais Recém-Nascidos , Feminino , Fatores de Transcrição Forkhead/deficiência , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Heterozigoto , Humanos , Recém-Nascido , Pulmão/anormalidades , Pulmão/irrigação sanguínea , Masculino , Redes e Vias Metabólicas , Camundongos , Camundongos Knockout , Síndrome da Persistência do Padrão de Circulação Fetal/metabolismo , Alvéolos Pulmonares/irrigação sanguínea , Alvéolos Pulmonares/metabolismo , Veias Pulmonares/anormalidadesRESUMO
Orbital metastasis from solid tumours is an uncommon entity and lung, breast and nasopharyngeal cancers are the common sites causing such a metastasis. Proptosis as the only presenting feature without any symptom suggesting lung as the primary site is very rare. Here is a report of a patient who presented with proptosis as the only complaint and subsequent investigations proved it to be due to small cell lung cancer metastasis and without metastatic spread to any other site.