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Germ cell transplantation in fish is a promising technique for surrogate broodstock parents with broader application in aquaculture and conserving endangered and valuable genetic resources. Herein, we describe the establishment of an intrapapillary xenogeneic transplant of germ cells from sexually mature goldfish (C. auratus) males into common carp (C. carpio) males cytoablated with a thermochemical treatment (two doses of busulfan at 40 mg/kg at 35°C). To analyze the presence and development of donor germ cells in recipient testes, donor germ cells were labeled with PKH26, a fluorescent cell membrane dye, before transplantation. Our results demonstrated that thermochemical treatment caused effective spermatogenesis suppression and pronounced germ cell loss. Moreover, transplanted spermatogonial cells were able to colonize the recipients' testes, resume spermatogenesis, and generate spermatozoa within eight weeks after germ cell transplantation. These findings suggested that recipient testes provided suitable conditions for the survival, colonization, proliferation, and differentiation of donor spermatogonia from a related species. This study indicated that recipients' testes exhibited a high degree of plasticity to accept and support xenogeneic donor germ cells, which were able to form sperm in a short time frame. This approach has significant implications for assisted animal reproduction, biotechnology, conservation, and the production of valuable genetic resources and endangered fish species.
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BRAF genomic alterations are the most common oncogenic drivers in pediatric low-grade glioma (pLGG). Arm 1 (n = 77) of the ongoing phase 2 FIREFLY-1 (PNOC026) trial investigated the efficacy of the oral, selective, central nervous system-penetrant, type II RAF inhibitor tovorafenib (420 mg m-2 once weekly; 600 mg maximum) in patients with BRAF-altered, relapsed/refractory pLGG. Arm 2 (n = 60) is an extension cohort, which provided treatment access for patients with RAF-altered pLGG after arm 1 closure. Based on independent review, according to Response Assessment in Neuro-Oncology High-Grade Glioma (RANO-HGG) criteria, the overall response rate (ORR) of 67% met the arm 1 prespecified primary endpoint; median duration of response (DOR) was 16.6 months; and median time to response (TTR) was 3.0 months (secondary endpoints). Other select arm 1 secondary endpoints included ORR, DOR and TTR as assessed by Response Assessment in Pediatric Neuro-Oncology Low-Grade Glioma (RAPNO) criteria and safety (assessed in all treated patients and the primary endpoint for arm 2, n = 137). The ORR according to RAPNO criteria (including minor responses) was 51%; median DOR was 13.8 months; and median TTR was 5.3 months. The most common treatment-related adverse events (TRAEs) were hair color changes (76%), elevated creatine phosphokinase (56%) and anemia (49%). Grade ≥3 TRAEs occurred in 42% of patients. Nine (7%) patients had TRAEs leading to discontinuation of tovorafenib. These data indicate that tovorafenib could be an effective therapy for BRAF-altered, relapsed/refractory pLGG. ClinicalTrials.gov registration: NCT04775485 .
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Vaga-Lumes , Glioma , Humanos , Criança , Animais , Proteínas Proto-Oncogênicas B-raf/genética , Glioma/tratamento farmacológico , Glioma/genéticaRESUMO
BACKGROUND: Alzheimer's disease is a progressive neurodegenerative process with multifactorial characteristics. This disease follows the natural aging process, affecting mainly people over 65 years. Pharmacotherapeutic treatment currently combats symptoms related to cognitive function. Several targets have begun to attract the interest of the scientific community to develop new drug candidates which have better pharmacokinetic and lower toxicity parameters. OBJECTIVE: The present study aims to design new candidates for acetylcholinesterase/ß-secretase (AChE/BACE1) multitarget inhibitor drugs. METHODS: 17 natural products were selected from the literature with anticholinesterase activity and 1 synthetic molecule with inhibitory activity for BACE1. Subsequently, the molecular docking study was performed, followed by the derivation of the pharmacophoric pattern and prediction of pharmacokinetic and toxicological properties. Finally, the hybrid prototype was designed. RESULTS: All selected molecules showed interactions with their respective target enzymes. Derivation of the pharmacophoric pattern from molecules that interacted with the AChE enzyme resulted in 3 pharmacophoric regions: an aromatic ring, an electron-acceptor region and a hydrophobic region. The molecules showed good pharmacokinetic and toxicological results, showing no warnings of mutagenicity and/or carcinogenicity. After the hybridization process, three hybrid molecules were obtained, which showed inhibitory activity for both targets. CONCLUSION: It is concluded that research in the field of medicinal chemistry is advancing towards the discovery of new drug candidates that bring a better quality of life to patients with AD.
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Acetilcolinesterase , Secretases da Proteína Precursora do Amiloide , Secretases da Proteína Precursora do Amiloide/química , Ácido Aspártico Endopeptidases/química , Humanos , Simulação de Acoplamento Molecular , Qualidade de VidaRESUMO
Although lipomatous tumors are common, intra-articular occurrence is exceedingly rare and sparsely described in the literature. Regarding these rare entities, most are benign, progressively growing tumors and often occur in the knee, yet it is crucial to distinguish the less infrequent lipoma arborescens (LA) from the rarer synovial lipoma, as they differ in presentation and pathogenesis. Magnetic resonance imaging is the exam of choice in their assessment and in differential diagnosis, playing a central role nowadays. Excision and synovectomy, either arthroscopic or by arthrotomy, provide good outcomes with low recurrence rates. By reporting two surgically treated distinct cases of intra-articular lipomatous tumors of the knee, the authors intend to review the literature and discuss their etiology, clinical and imaging aspects as well as treatment approach.
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Small cell lung cancer (SCLC) is a leading cause of cancer death worldwide, with few treatment options. Rovalpituzumab tesirine (Rova-T) is an antibody-drug conjugate that targets delta-like 3 on SCLC cells to deliver a cytotoxic payload directly to tumor cells. In this study, the cardiac safety profile of Rova-T was assessed by evaluating changes in QT interval, electrocardiogram (ECG) waveform, heart rate, and proarrhythmic adverse events (AEs) after treatment with Rova-T in patients with previously treated extensive-stage SCLC. Patients underwent ECG monitoring for 2 weeks after each of 2 i.v. infusions of 0.3 mg/kg Rova-T over 30 minutes, administered 6 weeks apart. Forty-six patients received at least one dose of Rova-T. At the geometric mean Rova-T maximum serum concentration of 7,940 ng/mL, ECG monitoring showed no significant changes in the Fridericia-corrected QT (QTcF) interval; the upper limit of the 2-sided 90% confidence interval did not exceed 10 msec for any time point. There were no clinically significant changes in QRS or PR intervals, ECG waveforms, or heart rate after Rova-T administration. All patients experienced a treatment-emergent AE (TEAE); 78% had a grade ≥ 3 TEAE, 59% had a serious TEAE, and 41% had a cardiac-related TEAE. The TEAEs that might signal proarrhythmia tendencies were uncommon. Confirmed partial responses were observed in 24% of patients. Based on the evaluation of ECG data collected in this study from patients treated with Rova-T at 0.3 mg/kg i.v. administered every 6 weeks, a QTcF effect of clinical concern can be excluded.
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Anticorpos Monoclonais Humanizados/efeitos adversos , Antineoplásicos/efeitos adversos , Benzodiazepinonas/efeitos adversos , Imunoconjugados/efeitos adversos , Síndrome do QT Longo/diagnóstico , Neoplasias Pulmonares/tratamento farmacológico , Carcinoma de Pequenas Células do Pulmão/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais Humanizados/administração & dosagem , Antineoplásicos/administração & dosagem , Benzodiazepinonas/administração & dosagem , Cardiotoxicidade/diagnóstico , Cardiotoxicidade/etiologia , Eletrocardiografia/efeitos dos fármacos , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Imunoconjugados/administração & dosagem , Síndrome do QT Longo/induzido quimicamente , Masculino , Pessoa de Meia-IdadeRESUMO
Euchromatic histone-lysine N-methyltransferase 1 (EHMT1) and EHMT2 are upregulated in various human cancers, and their deregulation is associated with tumor development and progression. In this paper, we investigated the expression level of EHMT1/EHMT2 in acute lymphoblastic leukemia (ALL) and whether the modulation of these enzymes could have any cellular or molecular impact on ALL cells. For this, we used UNC0646 as a priming strategy to target EHMT1/EHMT2 and investigated its effect on proliferation and cell viability of Jurkat cells by MTT assay. Then, considering the IC50 and IC75, cellular death was determined by Annexin V/PI staining using flow cytometry. Finally, we investigated by RT-PCR the molecular bases that could be involved in the observed effects. Interestingly, accessing the International Microarray Innovations in Leukemia (MILE) study group, we detected that both EHMT1 and EHMT2 are overexpressed in ALL. More important, we determined that inhibition of EHMT1/EHMT2 significantly decreased Jurkat cell viability in a dose-dependent manner. Accordingly, we observed that inhibition of EHMT1/EHMT2 promoted Jurkat cell death, which was accompanied by increased expression of P53, TP73, BAX, and MDM4. These results clearly indicate that inhibition of EHMT1/EHMT2 induces pro-apoptotic gene expression in ALL and promotes cell death. More importantly, the modulation of these histone methyltransferases may be a promising epigenetic target for ALL treatment.
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Regulação Leucêmica da Expressão Gênica , Antígenos de Histocompatibilidade/genética , Histona-Lisina N-Metiltransferase/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Proteína Tumoral p73/genética , Proteína Supressora de Tumor p53/genética , Morte Celular , Proliferação de Células , Sobrevivência Celular , Simulação por Computador , Epigênese Genética , Humanos , Células JurkatRESUMO
Accurate measurement of clonal genotypes, mutational processes, and replication states from individual tumor-cell genomes will facilitate improved understanding of tumor evolution. We have developed DLP+, a scalable single-cell whole-genome sequencing platform implemented using commodity instruments, image-based object recognition, and open source computational methods. Using DLP+, we have generated a resource of 51,926 single-cell genomes and matched cell images from diverse cell types including cell lines, xenografts, and diagnostic samples with limited material. From this resource we have defined variation in mitotic mis-segregation rates across tissue types and genotypes. Analysis of matched genomic and image measurements revealed correlations between cellular morphology and genome ploidy states. Aggregation of cells sharing copy number profiles allowed for calculation of single-nucleotide resolution clonal genotypes and inference of clonal phylogenies and avoided the limitations of bulk deconvolution. Finally, joint analysis over the above features defined clone-specific chromosomal aneuploidy in polyclonal populations.
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Replicação do DNA/genética , Genoma Humano , Sequenciamento de Nucleotídeos em Larga Escala , Análise de Célula Única , Aneuploidia , Animais , Ciclo Celular/genética , Linhagem Celular Tumoral , Forma Celular , Sobrevivência Celular , Cromossomos Humanos/genética , Células Clonais , Elementos de DNA Transponíveis/genética , Diploide , Feminino , Genótipo , Humanos , Masculino , Camundongos , Mutação/genética , Filogenia , Polimorfismo de Nucleotídeo Único/genéticaRESUMO
PURPOSE: Idasanutlin, a selective small-molecule MDM2 antagonist in phase 3 testing for refractory/relapsed AML, is a non-genotoxic p53 activator with oral administration. To determine the need to conduct dedicated trial(s) for organ impairment on pharmacokinetic (PK) exposure and/or drug-drug interactions, a single dose of [14C]- and [13C]-labeled idasanutlin was evaluated. METHODS: This study was an open-label, non-randomized, single-center trial of idasanutlin to investigate the excretion balance, pharmacokinetics, metabolism, and absolute bioavailability of a single oral dose of [14C]-labeled idasanutlin and an IV tracer dose of [13C]-labeled idasanutlin in a single cohort of patients with solid tumors. After completing cycle 1 assessments, patients could have participated in an optional treatment extension of idasanutlin. Clinical endpoints were PK, and safety/tolerability. RESULTS: Co-administration of an oral dose of idasanutlin with an IV tracer dose revealed low systemic CL, a moderate Vd, and a moderate (40.1%) absolute bioavailability of idasanutlin. Idasanutlin and its major inactive metabolite, M4, were the major circulating moieties in plasma, and excretion of idasanutlin-associated radioactivity was primarily via the fecal route (91.5% of the dose), with negligible amounts recovered in urine, following oral administration. CONCLUSION: The clinical implications of this study support the conclusion that renal impairment is unlikely to significantly impact exposure to idasanutlin and M4 metabolite, whereas a significant hepatic impairment may potentially alter exposure to the parent drug and/or metabolite(s). The potential for drug-drug interactions is low.
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Antineoplásicos/administração & dosagem , Neoplasias/tratamento farmacológico , Proteínas Proto-Oncogênicas c-mdm2/antagonistas & inibidores , Pirrolidinas/administração & dosagem , para-Aminobenzoatos/administração & dosagem , Administração Oral , Adulto , Idoso , Disponibilidade Biológica , Estudos de Coortes , Interações Medicamentosas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pirrolidinas/farmacocinética , para-Aminobenzoatos/farmacocinéticaRESUMO
BACKGROUND: Helicobacter pylori (HP) is the most widespread chronic human infection worldwide and the most important pathogenic factor of gastric cancer. The calculated prevalence at the Clinical Hospital of the University of Chile from 2002 to 2005 was 44.9%. AIM: To determine the current prevalence of HP in patients undergoing an upper gastrointestinal endoscopy (UGI) and analyze its distribution according to age and endoscopic findings. MATERIAL AND METHODS: We reviewed 3.433 UGI performed during the year 2015, selecting those in which rapid urease test (RUT) was done. A positive RUT or a positive gastric biopsy (GB) were considered as HP infection. RESULTS: RUT was done in 1862 UGI (55%) performed in patients aged 51 ± 17 years, (66% women). In 23% of these endoscopies, the RUT was positive. A GB was obtained 43% of endoscopies and 30% were positive for HP. In 105 patients the RUT was negative and the GB positive (rendering a 19.5% false negative rate). HP was detected by RUT and GB in 29% of endoscopies. The highest prevalence of infection (38.1%) was found between 40 and 49 years. HP infection had odds ratio of 4.24 for nodular gastropathy, 2.63 for gastric ulcer and 2.14 for duodenal ulcer (p < 0.05). CONCLUSIONS: HP prevalence in our center decreased significantly from 44.9% to 28.9% in 11 years. False negative RUT results may bias this finding. The use of proton pump inhibitors and antimicrobials that can interfere with the detection of HP should be registered to properly analyze the results of the RUT.
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Gastroenteropatias/microbiologia , Infecções por Helicobacter/diagnóstico , Helicobacter pylori/isolamento & purificação , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Biópsia , Chile/epidemiologia , Estudos Transversais , Endoscopia Gastrointestinal , Feminino , Gastroenteropatias/diagnóstico , Gastroenteropatias/epidemiologia , Infecções por Helicobacter/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Adulto JovemRESUMO
Background: Helicobacter pylori (HP) is the most widespread chronic human infection worldwide and the most important pathogenic factor of gastric cancer. The calculated prevalence at the Clinical Hospital of the University of Chile from 2002 to 2005 was 44.9%. Aim: To determine the current prevalence of HP in patients undergoing an upper gastrointestinal endoscopy (UGI) and analyze its distribution according to age and endoscopic findings. Material and Methods: We reviewed 3.433 UGI performed during the year 2015, selecting those in which rapid urease test (RUT) was done. A positive RUT or a positive gastric biopsy (GB) were considered as HP infection. Results: RUT was done in 1862 UGI (55%) performed in patients aged 51 ± 17 years, (66% women). In 23% of these endoscopies, the RUT was positive. A GB was obtained 43% of endoscopies and 30% were positive for HP. In 105 patients the RUT was negative and the GB positive (rendering a 19.5% false negative rate). HP was detected by RUT and GB in 29% of endoscopies. The highest prevalence of infection (38.1%) was found between 40 and 49 years. HP infection had odds ratio of 4.24 for nodular gastropathy, 2.63 for gastric ulcer and 2.14 for duodenal ulcer (p < 0.05). Conclusions: HP prevalence in our center decreased significantly from 44.9% to 28.9% in 11 years. False negative RUT results may bias this finding. The use of proton pump inhibitors and antimicrobials that can interfere with the detection of HP should be registered to properly analyze the results of the RUT.
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Humanos , Masculino , Feminino , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Adulto Jovem , Helicobacter pylori/isolamento & purificação , Infecções por Helicobacter/diagnóstico , Gastroenteropatias/microbiologia , Biópsia , Chile/epidemiologia , Prevalência , Estudos Transversais , Estudos Retrospectivos , Endoscopia Gastrointestinal , Infecções por Helicobacter/epidemiologia , Distribuição por Idade , Gastroenteropatias/diagnóstico , Gastroenteropatias/epidemiologiaRESUMO
The role of growth factors (GFs) in controlling the biology of human hematopoietic stem cells (HSCs) remains limited by a lack of information concerning the individual and combined effects of GFs directly on the survival, Mitogenesis, and regenerative activity of highly purified human HSCs. We show that the initial input HSC activity of such a purified starting population of human cord blood cells can be fully maintained over a 21-day period in serum-free medium containing five GFs alone. HSC survival was partially supported by any one of these GFs, but none were essential, and different combinations of GFs variably stimulated HSC proliferation. However, serial transplantability was not detectably compromised by many conditions that reduced human HSC proliferation and/or survival. These results demonstrate the dissociated control of these three human HSC bio-responses, and set the stage for future improvements in strategies to modify and expand human HSCs ex vivo.
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Diferenciação Celular , Proliferação de Células , Sobrevivência Celular , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/metabolismo , Animais , Biomarcadores , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Transplante de Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas/efeitos dos fármacos , Humanos , Técnicas In Vitro , Integrina alfa6/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Camundongos , FenótipoRESUMO
Solitary bone plasmacytomas are part of a wide range of monoclonal neoplasms that share a common progenitor in the B lymphocyte lineage. In their particular case, a single bone lesion is found, most frequently on the axial skeleton, having evidence of no other osteolytic lesions or systemic involvement. Diagnosis can sometimes prove to be difficult as they are rare tumors, occurring in 3 to 5% (up to 10% in some series) of patients with plasma cell neoplasms, with important considerations regarding the differential diagnosis. We report a case of a solitary bone plasmacytoma, found on the ala of the left ilium of a patient during a routine consult due to hip pain.
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INTRODUCTION: Laryngeal tuberculosis (LTB) is the most frequent granulomatous disease of the larynx and represents less than 2% of extrapulmonary TB cases. There are no pathognomonic clinical and endoscopic features of this disease and studies on LTB that can assist in its diagnostic characterization are lacking. OBJECTIVE: To identify factors associated with clinical and topographical features of LTB. METHOD: a retrospective cross-sectional study was conducted from the medical records of 36 patients with confirmed LTB diagnosis. RESULTS: Dysphonia and cough were the main symptoms presented by patients and the true vocal folds the most frequently affected site. The average of the duration of the disease evolution was significantly higher in patients with dysphonia than in patients without this symptom. We observed association between dysphonia and true vocal fold lesions and between odynophagia and lesions in the epiglottis, arytenoids and aryepiglottic folds. Odynophagia was more frequent in individuals with lesions in four or more laryngeal sites. Weight loss equal or above 10% of the body weight was more frequent in patients with odynophagia as first symptom and in patients with ulcerated lesion. Dyspnea on exertion was more frequent in individuals with more extensive laryngeal lesions. The percentage of smokers with lesions in four or more laryngeal sites was greater than that found in non-smokers. Laryngeal tissue fragment bacilloscopy and culture examinations were less positive than sputum ones. CONCLUSIONS: Smoking appears to be associated with the development of more extensive LTB lesions, and LTB with dyspnea on exertion and odynophagia with consequent impairment of nutritional status. We emphasize the need for histopathologic confirmation, once positive sputum bacteriological examinations seem not to necessarily reflect laryngeal involvement.
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Tuberculose Laríngea/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Peso Corporal , Tosse/etiologia , Estudos Transversais , Demografia , Dispneia/etiologia , Feminino , Humanos , Laringoscopia , Laringe/patologia , Masculino , Pessoa de Meia-Idade , Mycobacterium/isolamento & purificação , Radiografia , Estudos Retrospectivos , Fumar , Escarro/microbiologia , Tuberculose Laríngea/diagnóstico por imagem , Tuberculose Laríngea/microbiologia , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/diagnóstico por imagemRESUMO
INTRODUCTION: Laryngeal tuberculosis (LTB) is the most frequent larynx granulomatous disease. In general there is lung involvement, but in an important proportion of cases you can find LTB without pulmonary disease. The lesions observed in LTB, such as ulceration and fibrosis, can interfere in the process of voice production. The involvement of the mucous lining of the vocal folds can change their flexibility and, consequently, change voice quality, and the main symptom is dysphonia present in almost 90% of cases. OBJECTIVE: To describe the anatomical characteristics and voice quality in LTB patients. MATERIAL AND METHOD: A descriptive cross-sectional study was conducted with 24 patients. RESULT: The most frequently affected sites were vocal folds in 87.5% patients, vestibular folds in 66.7%, epiglottis in 41.7%, arytenoid in 50%, aryepiglottic folds in 33.3%, and interarytenoid region in 33.3% patients. We found 95.8% cases of dysphonia. The voice acoustic analysis showed 58.3% cases of Jitter alterations, 83.3% of Shimmer and 70.8% of GNE. CONCLUSION: Voice disorders found in active laryngeal tuberculosis are similar to those reported after clinical healing of the disease, suggesting that sequelae and vocal adjustments may install during the active phase of the disease, negatively impacting the process of vocal quality reestablishment.
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Tuberculose Laríngea/complicações , Distúrbios da Voz/diagnóstico , Distúrbios da Voz/etiologia , Adulto , Idoso , Estudos Transversais , Disfonia , Feminino , Rouquidão , Humanos , Laringoscópios , Masculino , Pessoa de Meia-Idade , Prega Vocal/microbiologia , Prega Vocal/patologia , Prega Vocal/fisiopatologia , Qualidade da VozRESUMO
Ricin, Ricinus communis agglutinin 60 - RCA 60, is a deadly phytotoxic protein which inhibits ribosomes (class II), and there is no known effective antidote in living organisms. Ricin is composed of two polypeptide chains, A and B, linked covalently by a single disulfide bond. The analytical methods for the detection of RCA 60 are commonly laborious, expensive, require skilled labor, and involve sophisticated equipment. Aimed at the development of electroanalytical methods for RCA 60 detection, here we studied the electrochemical oxidation of RCA 60 on a glassy carbon (GC) electrode over a wide pH range, using cyclic voltammetry, differential pulse voltammetry (DPV) and square wave voltammetry (SWV). Two quasi-reversible electrochemical RCA 60 oxidation peaks were identified on the GC electrode by SWV. For values of 2.2 ≤ pH ≤ 10.2, DPV studies revealed that the peak potentials, EP1 and EP2, display a linear dependence with pH and the reaction mechanism involves the transfer of 2Hâº/2eâ» (peak 1) and 1Hâº/1eâ» (peak 2). The first and second RCA 60 oxidation steps may correspond to the oxidation of cysteine and tyrosine-tryptophan residues, respectively. The oxidation product of the second RCA 60 oxidation step appears at 7.0 ≤ pH ≤ 11.8. For pH ≥ 10.2, both processes are pH independent, resulting in a pKa of ca. 10.2. A third RCA 60 oxidation peak only appears at acidic pH. RCA 60 samples extracted from different castor seed cultivars showed similar electrochemical behavior, enabling the implementation of an analytical voltammetric method.
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Carbono/química , Técnicas Eletroquímicas/métodos , Vidro/química , Ricina/análise , Sequência de Aminoácidos , Eletrodos , Dados de Sequência Molecular , Estrutura Secundária de Proteína , Ricina/genéticaRESUMO
The maturation of the hepatitis C virus (HCV) core protein requires proteolytic processing by two host proteases: signal peptidase (SP) and the intramembrane-cleaving protease signal peptide peptidase (SPP). Previous work on HCV genotype 1a (GT1a) and GT2a has identified crucial residues required for efficient signal peptide processing by SPP, which in turn has an effect on the production of infectious virus particles. Here we demonstrate that the JFH1 GT2a core-E1 signal peptide can be adapted to the GT3a sequence without affecting the production of infectious HCV. Through mutagenesis studies, we identified crucial residues required for core-E1 signal peptide processing, including a GT3a sequence-specific histidine (His) at position 187. In addition, the stable knockdown of intracellular SPP levels in HuH-7 cells significantly affects HCV virus titers, further demonstrating the requirement for SPP for the maturation of core and the production of infectious HCV particles. Finally, our nuclear magnetic resonance (NMR) structural analysis of a synthetic HCV JFH1 GT2a core-E1 signal peptide provides an essential structural template for a further understanding of core processing as well as the first model for an SPP substrate within its membrane environment. Our findings give deeper insights into the mechanisms of intramembrane-cleaving proteases and the impact on viral infections.
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Ácido Aspártico Endopeptidases/metabolismo , Hepacivirus/metabolismo , Hepatite C/metabolismo , Sinais Direcionadores de Proteínas , Proteínas do Core Viral/metabolismo , Ácido Aspártico Endopeptidases/química , Ácido Aspártico Endopeptidases/genética , Células HEK293 , Hepacivirus/química , Hepacivirus/genética , Hepatite C/genética , Humanos , Mutagênese , Ressonância Magnética Nuclear Biomolecular , Proteínas do Core Viral/química , Proteínas do Core Viral/genéticaRESUMO
In this article an ultrasound elastography technology is reported which provides quantitative images of tissue elasticity from deep soft tissue. The technique is analogous to Magnetic Resonance Elastography in the use of external mechanical vibrations which can penetrate deep tissue. Multifrequency steady-state mechanical vibrations are applied to the tissue at the skin and tissue displacements are measured by a conventional ultrasound system. Absolute values of tissue elasticity are computed in real-time for each frequency and displayed to the physician. The quantitative elasticity images produced by the technology are validated with magnetic resonance elastography images as the gold standard on standard elasticity phantoms. Preliminary in-vivo data from healthy volunteers are presented which show the potential of the technology for clinical use. The system is currently being used in different clinical studies to image kidney fibrosis, liver fibrosis, and prostate cancer.
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Técnicas de Imagem por Elasticidade/instrumentação , Interpretação de Imagem Assistida por Computador/instrumentação , Imageamento por Ressonância Magnética/instrumentação , Sistemas Computacionais , Desenho de Equipamento , Análise de Falha de Equipamento , Aumento da Imagem/instrumentação , Miniaturização , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
Multilayer Soft Lithography (MSL) is a robust and mature fabrication technique for the rapid prototyping of microfluidic circuits having thousands of integrated valves. Despite the success and wide application of this method, it is fundamentally a planar fabrication technique which imposes serious design constraints on channel routing, feature density, and fluid handling complexity. We present here methods and related instrumentation to remove these limitations by combining the advantages of MSL processing with laser micromachining using a CO(2) laser ablation system. This system is applied to both the dense integration of layer-layer interconnects and the direct writing of microchannels. Real-time image recognition and computer control allow for robust wafer-scale registration of laser ablation features with moulded channel structures. Ablation rates of up to 8 Hz are achieved with positional accuracy of approximately 20 microm independent of mechanical distortions in the elastomer substrate. We demonstrate these capabilities in the design and fabrication of a production scale multi-laminate micromixer that achieves sub-millisecond mixing of two streams at flow rates up to 1 mL min(-1). The marriage of laser micromachining with MSL-based valve integration allows for high-yield fabrication of topologically complex microfluidic circuits having thousands of layer-layer interconnects and integrated valves.