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INSOMNIA: DEFINITIONS, EPIDEMIOLOGY AND CHANGES WITH AGE. Chronic insomnia is a disorder defined as a subjective complaint relating to the quality and/or quantity of sleep associated with daytime impact, and which must be present 3 nights per week for a period of at least 3 months. This is a common sleep problem in the general population and represents a significant proportion of reasons for consultation in the general practice. It requires early identification at all ages of life to allow the establishment of adequate care, which will have the benefit of both improving the quality of life of these patients in the short term and preventing the consequences of chronic insomnia.
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Distúrbios do Início e da Manutenção do Sono , Humanos , Distúrbios do Início e da Manutenção do Sono/epidemiologia , Distúrbios do Início e da Manutenção do Sono/terapia , Qualidade de VidaRESUMO
SCOPE: Carrot (Daucus carota) allergy is caused by the major carrot allergen Dau c 1, which is a mixture of several isoallergens and variants with sequence identities of >67% or >90%, respectively. However, little is known about the qualitative and quantitative composition of natural Dau c 1. METHODS AND RESULTS: Mass spectrometry of isolated natural Dau c 1 reveals the existence of several yet unknown Dau c 1-like proteins. The study expresses four Dau c 1-like proteins in Escherichia coli. Two of the purified proteins, designated Dau c 1.0501 and 1.0601, exhibit sequence identities to Dau c 1.0101 and 1.0401 between 54% and 87%. They possess allergenic potential and are accepted as new isoallergens. One protein, designated as Dau c 1-like is >50% identical with the new isoallergens but exhibits no allergenicity. Sequence and structural comparisons of this protein with the known Dau c 1 isoallergens offer relevant clues about putative structural IgE epitopes. CONCLUSION: Identification of new isoallergens and the identification of IgE epitopes may contribute to a more refined component resolved diagnosis and may lay ground for further epitope mapping and personalized targeted treatment approaches of carrot allergy in preclinical and clinical studies.
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Daucus carota , Hipersensibilidade , Humanos , Alérgenos/química , Daucus carota/química , Proteínas de Plantas/química , Antígenos de Plantas/química , Epitopos/metabolismo , Imunoglobulina E/metabolismoRESUMO
Among the various methods of targeted drug delivery, magnetic nanoparticles been considered for a long time due to local drug delivery, reduction of side effects, and controlled drug release. In this work, fluorescence resonance energy transfer (FRET) system MnFe2O4@SiO2@ graphene quantum dots /DAU with 28.02 emu g-1 magnetism was prepared as pH-sensitive nanoplatform to enhance the anti-cancer effect of daunorubicin (DAU) drug (in the obtained FRET system, DAU act as acceptor molecule and graphene quantum dots act as donor molecule). The efficiency of the drug loaded on the nanoplatform in vitro is 78 %. DAU drug release from nanoplatform at pHs of 7.4 and 5.5 during 48 h is 21 % and 60 %, respectively. Release sensitive to pH facilitates the application of prepared nanoplatform for DAU delivery. The results of MTT-assay and annexin V-FITC/PI show that MnFe2O4@SiO2@ graphene quantum dots /DAU induces cell apoptosis by inhibiting the growth of more than 95 % of MCF-7 cells. Also, according to the results, it was found that MnFe2O4@SiO2@ graphene quantum dots /DAU can inhibit 66.65 % cell cycle in the sub-G1 phase. Therefore, due to the anti-cancer activity of MnFe2O4@SiO2@ graphene quantum dots /DAU, this biological nanoscale can be considered a candidate for drug delivery.
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Grafite , Neoplasias , Pontos Quânticos , Humanos , Grafite/química , Pontos Quânticos/química , Transferência Ressonante de Energia de Fluorescência/métodos , Dióxido de Silício/química , Preparações Farmacêuticas , Daunorrubicina/química , Fenômenos MagnéticosRESUMO
Immunohematology laboratories are regularly facing transfusion issues due to serological weaknesses. Altered (partial) RH antigens account for most of them. In some situations, RHCE variant alleles are involved. Herein we present our three-step molecular exploration, with allele frequencies, that has efficiently untangled RH2 phenotype weaknesses and discrepancies in our 2017-2021 cohort. In the last 5 years, the PACA Corse EFS molecular platform received 265 samples from healthy blood donors or patients with C and C/e typing difficulties. The first-intention technique (DNA array and real time PCR for RHCE*CeRN research) detected RHCE variant alleles in 143 cases (54%). The RHCE alleles classically found in African populations were the most frequent, with RHCE*CeRN allele in 40 cases (15%) and (C)ces haplotype type 1 and 2 in 26 cases (10%). A "CE" effect haplotype was suspected in 56 cases, due to the uncommon DCE haplotype that may explain the low C expression. When there were no RHCE*Ce or RHCE*CE alleles, we then searched for RHD polymorphisms by DNA array. We detected the RHD*DAU5 and RHD*DIVa in 18 and 7 cases respectively, suggesting that C ambiguity is related to the presence of these alleles which has never been described with DAU5. If no variant RHCE and RHD alleles were detected, we finally sequenced the 10 exons of both RHCE and RHD genes according to the clinical context and found seven new RHCE alleles. Thus, this molecular strategy would improve the knowledge of RHCE variants' expression and, thus, optimize the transfusion management.
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Sistema do Grupo Sanguíneo Rh-Hr , Alelos , Éxons , Frequência do Gene , Haplótipos , Humanos , Sistema do Grupo Sanguíneo Rh-Hr/genéticaRESUMO
Oxalyl chloride is one of the most versatile reagents used in organic synthesis. Oxalyl chloride was employed in the convenient one-pot, two-step synthesis of the fungus-derived naturally occurring lipoids: N,N'-dipalmitoleyl urea (C16:1) and N,N'-dioleyl urea (C18:1). The two symmetrical diacyl urea-based natural products were previously identified as fungus-specific pathogen-associated molecules (PAMs), which act as inflammatory mediators during fungal infection. The highly lipophilic natural lipoids were efficiently synthesized from commercially available reagents in yields ranging from good to very good.
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Produtos Biológicos , Ureia , Técnicas de Química Sintética , FungosRESUMO
SCOPE: Around 25% of food allergic persons in Central Europe suffer from carrot allergy caused by the major carrot allergen Dau c 1. Three different isoallergens, Dau c 1.01, Dau c 1.02 and Dau c 1.03 are identified. However, information about the qualitative and quantitative composition of natural (n)Dau c 1 is scarce. METHODS AND RESULTS: The new carrot allergen Dau c 1.0401 is identified on the mRNA and protein level by RT-PCR and mass spectrometry. It displays only around 60% sequence identity to the other known Dau c 1 isoallergens. NMR and CD-spectra are typical for a well-folded protein containing both α-helices and ß-strands. It showed a poor refolding capacity after incubation at 95 °C. IgE-binding is impaired in immunoblots, whereas in inhibition assays IgE binding to soluble Dau c 1.0401 is detected and it clearly provoked a response in mediator release assays. CONCLUSION: Dau c 1.0401 is a new isoallergen which contributes to the allergenicity of carrots. The absence of immunoreactivity in immobilized assays indicates that IgE binding is impaired when the protein is blotted on a solid phase. Altogether, the results point out that its allergenicity can be reduced upon carrot processing.
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Alérgenos/química , Alérgenos/imunologia , Alérgenos/metabolismo , Antígenos de Plantas/imunologia , Daucus carota/imunologia , Hipersensibilidade Alimentar/imunologia , Proteínas de Plantas/imunologia , Alérgenos/genética , Antígenos de Plantas/química , Antígenos de Plantas/genética , Antígenos de Plantas/metabolismo , Clonagem Molecular , Humanos , Soros Imunes , Imunoglobulina E/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/genéticaRESUMO
SCOPE: The major carrot allergen Dau c 1 belongs to the group of pathogenesis related class 10 (PR-10) proteins and is homologous to the birch pollen allergen Bet v 1. In contrast to most other PR-10 allergens, Dau c 1 can elicit Bet v 1 independent sensitization. Although Dau c 1 is considered heat labile, allergic reactions against cooked carrots are possible. METHODS AND RESULTS: The pH and temperature stability as well as the allergenic potential before and after treatment of purified natural (n) Dau c 1 and different recombinant (r) isoallergens is investigated: rDau c 1.0104, rDau c 1.0105, rDau c 1.0201, rDau c 1.0301. All proteins except rDau c 1.0201 are able to refold at physiological pH. pH conditions around the pI (4.4-5.5) or the presence of the carrot matrix reduce the refolding capacity. Below the pI, most isoallergens are heat resistant and still able to cause mediator release, indicating allergenicity. Moreover, cooked carrot extract is still able to provoke mediator release due to remaining soluble Dau c 1. CONCLUSION: Patients allergic to carrots should avoid processed carrot containing foodstuff because heating or pH treatment do not completely abolish the allergenicity of Dau c 1.
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Antígenos de Plantas/química , Daucus carota/química , Manipulação de Alimentos/métodos , Hipersensibilidade Alimentar/etiologia , Proteínas de Plantas/química , Antígenos de Plantas/genética , Antígenos de Plantas/imunologia , Dicroísmo Circular , Daucus carota/imunologia , Humanos , Concentração de Íons de Hidrogênio , Espectroscopia de Ressonância Magnética , Proteínas de Plantas/genética , Proteínas de Plantas/imunologia , Redobramento de Proteína , Estabilidade Proteica , TemperaturaRESUMO
BACKGROUND: ß-Glucosidases have attracted considerable attention due to their important roles in various biotechnological processes such as cellulose degradation to make energy and hydrolysis of isoflavone. Microbulbifer thermotolerans (M. thermotolerans) is isolated from deep-sea sediment and has not been researched much yet. As a potential candidate for a variety of biotechnological industries, ß-glucosidases from the novel bacterial species should be researched extensively. METHODS: ß-Glucosidase, MtBgl85, from M. thermotolerans DAU221 was purified by His-tag affinity chromatography and confirmed by SDS-PAGE and zymogram. Its biochemical and physiological properties, such as effects of temperature, pH, metal ions, and organic solvents, substrate specificity, and isoflavone hydrolysis, were investigated. RESULTS: M. thermotolerans DAU221 showed ß-glucosidase activity in a marine broth plate containing 0.1% esculin and 0.25% ammonium iron (III) citrate. The ß-glucosidase gene, mtbgl85, was isolated from the whole genome sequence of M. thermotolerans DAU221. The ß-glucosidase gene was 2,319 bp and encoded 772 amino acids. The deduced amino acid sequence had a 43% identity with OaBGL84 from Olleya aquimaris and 35% and 32% identity with to CfBgl3A and CfBgl3C from Cellulomonas fimi among bacterial glycosyl hydrolase family 3, respectively. The optimal temperature of MtBgl85 was 50 °C and the optimum pH was 7.0. MtBgl85 activity was strongly reduced in the presence of Hg2+ and Cu2+ ions. As a result of measuring the activity at various concentrations of NaCl, it was confirmed that the activity was maintained up to the concentration of 1 M, but gradually decreased with increasing concentration. MtBgl85 showed higher enzyme stability at non-polar solvents (high Log Pow ) than polar solvents (low Log Pow ). The hydrolyzed products of isoflavone glycosides and arbutin were analyzed by HPLC.
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BACKGROUND: The ability to use organic solvents in enzyme reactions offers a number of industrially useful advantages. However, most enzymes are almost completely inactive in the presence of organic solvents. Thus, organic solvent-tolerant enzymes have potential applications in industrial processes. RESULTS: A chitinase gene from Microbulbifer thermotolerans DAU221 (mtch509) was cloned and expressed in Escherichia coli BL21 (DE3). The molecular weight of the expressed MtCh509 protein was approximately 60 kDa, and it was purified by His-tag affinity chromatography. Enzymatic assays showed that the optimum temperature for MtCh509 chitinase activity was 55 °C, and the enzyme was stable for 2 h at up to 50 °C. The optimum pH for MtCh509 activity was in the sub-acidic range, at pH 4.6 and 5.0. The activity of MtCh509 was maintained in presence of 1 M salt, gradually decreasing at higher concentrations, with residual activity (20%) detected after incubation in 5 M salt. Some organic solvents (benzene, DMSO, hexane, isoamyl alcohol, isopropyl alcohol, and toluene; 10-20%, v/v) increased the reactivity of MtCh509 relative to the aqueous system. When using NAG3, as a substrate, MtCh509 produced NAG2 as the major product, as well as NAG4, demonstrating that MtCh509 has transglycosylation activity. The K m and V max values for MtCh509 using colloidal chitin as a substrate were 9.275 mg/mL and 20.4 U/mg, respectively. Thus, MtCh509 could be used in extreme industrial conditions. CONCLUSION: The results of the hydrolysate analysis and the observed increase in enzyme activity in the presence of organic solvents show that MtCh509 has industrially attractive advantages. This is the first report on an organic solvent-tolerant and transglycosylating chitinase from Microbulbifer species.
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The free and covalently bound microcystins (MCs) in 3 fish and 2 bivalves from the Dau Tieng Reservoir in Vietnam were investigated for the first time in the present study. The results showed that all species were contaminated with MCs. Our findings indicate that eating the muscle of fish from the Dau Tieng Reservoir is safe but that eating the bivalves is not safe during toxic cyanobacterial bloom episodes. Environ Toxicol Chem 2017;36:2953-2957. © 2017 SETAC.
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Bivalves/química , Peixes/metabolismo , Microcistinas/química , Animais , Bivalves/metabolismo , Cromatografia Líquida de Alta Pressão , Cianobactérias/metabolismo , Análise de Alimentos , Humanos , Microcistinas/análise , Microcistinas/metabolismo , Medição de Risco , VietnãRESUMO
Cellulophaga lytica DAU203 (KACC 19187), isolated from the marine sediment in Korea, has a strong ability to degrade agar. The genome of C. lytica DAU203 contains a single chromosome that is 3,952,957bp in length, with 32.02% G+C contents. The genomic information predicted that the DAU203 has the potential to be utilized in various enzymatic industries.
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Proteínas de Bactérias/genética , Flavobacteriaceae/enzimologia , Flavobacteriaceae/genética , Genoma Bacteriano , Sedimentos Geológicos/microbiologia , Glicosídeo Hidrolases/genética , Proteínas de Bactérias/metabolismo , Glicosídeo Hidrolases/metabolismo , Sequenciamento Completo do GenomaRESUMO
BACKGROUND: Antigens DIIIa, DAR and DAU are common in people of African descent and are involved in anti-D alloimmunization. Sickle cell disease (SCD) patients frequently need blood therapy and are vulnerable to alloimmunization. METHODS: The study included SCD patients from the Brazilian state of Bahia, which has the highest incidence of the disease in Brazil; 241 SCD patients and 220 healthy individuals were studied. Alleles were characterized by PCR-RFLP and PCR-SSP techniques. RESULTS: The DAU allele was found in 22.3% (43/193) of the SCD patients. Two (1%) patients had the DIIIa/D wild-type genotype, one (0.5%) had the DIIIa/D- genotype, 11 (5.7%) had the DAR/D wild-type genotype and three (1.6%) had the DAR/D- genotype. Two patients were positive for the 667T>G mutation and the 1136C>T mutation, one (0.5%) had the genotype DIIIa/DAU, and one (0.5%) had the genotype DAR/DAU. CONCLUSION: There was statistical significance when the allele frequencies were evaluated among SCD, sickle cell anemia (HbSS) patients and healthy individuals. The frequencies of the DIIIa, DAR and DAU alleles among SCD patients differ from those of healthy individuals from the same population, and a high frequency of the DAU variant was associated with anti-D alloimmunization in these patients.
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BACKGROUND: In contrast to other Bet v 1-related food allergens, the major carrot allergen, Dau c 1, has been suggested to induce food allergy independently from Bet v 1. As T cells are crucial in the sensitization process, we sought to characterize the T-cell response to Dau c 1 and its cross-reactivity with Bet v 1. METHODS: Dau c 1-specific T-cell lines (TCL) and clones (TCC) established from PBMC of birch pollen-allergic patients with carrot allergy were analyzed for reactivity to Bet v 1, epitope specificity, allergen-induced cytokine secretion, and expression of integrins α4ß7 and α4ß1, critical for gut and lung homing, respectively. mRNA expression of GATA3 and Tbet was analyzed in sorted CD3+ CD4+ CFSElow cells proliferating upon stimulation of PBMC with Dau c 1 or Bet v 1. Dau c 1 was incubated with endolysosomal proteases, and the resulting fragments were identified by mass spectrometry. RESULTS: Among 14 distinct T-cell-activating regions, Dau c 1139-153 was recognized by 55% of the patients. Only 6 of 15 (40%) Dau c 1-specific TCL and 9 of 21 (43%) TCC reacted with Bet v 1. Bet v 1-nonreactive TCC were mainly Th1-like and showed a higher expression of the integrin ß7 and a significantly lower expression of the integrin ß1 than Bet v 1-positive TCC. A Th1-like response was also detected in Dau c 1-reactive CD3+ CD4+ CFSElow cells. Full-length Dau c 1 was still detectable after 48 h of endolysosomal degradation. Proteolytic fragments of Dau c 1 matched its T-cell-activating regions. CONCLUSION: Dau c 1 displays several characteristics of sensitizing allergens, namely a major T-cell-activating region, low susceptibility to endolysosomal degradation, and induction of a Bet v 1-independent T-cell response. These cellular insights confirm that the major carrot allergen has a special status among Bet v 1-related food allergens.
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Alérgenos/imunologia , Antígenos de Plantas/imunologia , Daucus carota/imunologia , Hipersensibilidade Alimentar/imunologia , Proteínas de Plantas/imunologia , Linfócitos T/imunologia , Especificidade de Anticorpos/imunologia , Reações Cruzadas/imunologia , Endossomos/metabolismo , Epitopos de Linfócito T/imunologia , Hipersensibilidade Alimentar/genética , Hipersensibilidade Alimentar/metabolismo , Humanos , Imunoglobulina E/imunologia , Lisossomos/metabolismo , Especificidade do Receptor de Antígeno de Linfócitos T/imunologia , Linfócitos T/metabolismoRESUMO
Microbulbifer thermotolerans DAU221 was preliminary isolated from the marine sediment samples in the Republic of Korea. Here, we present the complete genome sequence of M. thermotolerans DAU221, which consisted of 3,938,396 base pairs with a GC content of 56.57%. This genomic information should help us find the industrially useful enzymes.
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Proteínas e Peptídeos de Choque Frio/genética , Gammaproteobacteria/enzimologia , Gammaproteobacteria/genética , Genoma Bacteriano/genética , Sedimentos Geológicos/microbiologia , Temperatura Baixa , Gammaproteobacteria/fisiologia , Análise de Sequência de DNARESUMO
A novel esterase, MtEst45, was isolated from a fosmid genomic library of Microbulbifer thermotolerans DAU221. The encoding gene is predicted to have a mass of 45,564 Da and encodes 495 amino acids, excluding a 21 amino acid signal peptide. MtEst45 showed a low amino acid identity (approximately 23-24%) compared with other lipolytic enzymes belonging to Family III, a closely related bacterial lipolytic enzyme family. MtEst45 also showed a conserved GXSXG motif, G131IS133YG135, which was reported as active site of known lipolytic enzymes, and the putative catalytic triad composed of D237 and H265. Because these mutants of MtEst45, which was S133A, D237N, and H265L, had no activity, these catalytic triad is deemed essential for the enzyme catalysis. MtEst45 was overexpressed in Escherichia coli BL21 (DE3) and purified via His-tag affinity chromatography. The optimal pH and temperature of MtEst45 were estimated to be 8.17 and 46.27°C by response surface methodology, respectively. Additionally, MtEst45 was also active between 1 and 15°C. The optimal hydrolysis substrate for MtEst45 among p-nitrophenyl esters (C2-C18) was p-nitrophenyl butyrate, and the K m and V max values were 0.0998 mM and 550 µmol/min/mg of protein, respectively. MtEst45 was strongly inhibited by Hg(2+), Zn(2+), and Cu(2+) ions; by phenylmethanesulfonyl fluoride; and by ß-mercaptoethanol. Ca(2+) did not affect the enzyme's activity. These biochemical properties, sequence identity, and phylogenetic analysis suggest that MtEst45 represents a novel and valuable bacterial lipolytic enzyme family and is useful for biotechnological applications.
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Pancreatic neuroendocrine tumors (PNETs) are rare, indolent tumors that may occur sporadically or develop in association with well-recognized hereditary syndromes, particularly multiple endocrine neoplasia type 1 (MEN-1). We previously demonstrated that the hedgehog (HH) signaling pathway was aberrantly up-regulated in a mouse model that phenocopies the human MEN-1 syndrome, Men1l/l;RipCre, and that inhibition of this pathway suppresses MEN-1 tumor cell proliferation. We hypothesized that the HH signaling pathway is similarly upregulated in human PNETs. We performed immunohistochemical (IHC) staining for PTCH1 in human fresh and archival PNET specimens to examine whether human sporadic and MEN-1-associated PNETs revealed similar abnormalities as in our mouse model and correlated the results with clinical and demographic factors of the study cohort. PTCH1 staining was positive in 12 of 22 PNET patients (55%). Four of 5 MEN-1 patients stained for PTCH1 (p = 0.32 as compared with sporadic disease patients). Nine of 16 patients with metastatic disease stained for PTCH1 as compared with zero of 3 with localized disease only (p = 0.21). No demographic or clinical features appeared to be predictive of PTCH 1 positivity and PTCH 1 positivity per se was not predictive of clinical outcome. PTCH1, a marker of HH pathway up regulation, is detectable in both primary and metastatic tumors in more than 50% of PNET patients. Although no clinical or demographic factors predict PTCH1 positivity and PTCH1 positivity does not predict clinical outcome, the frequency of expression alone indicates that perturbation of this pathway with agents such as Vismodegib, an inhibitor of Smoothened (SMO), should be examined in future clinical trials.
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Neoplasia Endócrina Múltipla/metabolismo , Tumores Neuroendócrinos/metabolismo , Neoplasias Pancreáticas/metabolismo , Receptores de Superfície Celular/metabolismo , Adulto , Estudos de Coortes , Terapia Combinada , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Neoplasia Endócrina Múltipla/diagnóstico , Neoplasia Endócrina Múltipla/terapia , Gradação de Tumores , Metástase Neoplásica , Tumores Neuroendócrinos/diagnóstico , Tumores Neuroendócrinos/terapia , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/terapia , Receptores Patched , Receptor Patched-1 , Resultado do Tratamento , Carga TumoralRESUMO
Nematode dauer formation represents an essential survival and dispersal strategy and is one of a few ecologically relevant traits that can be studied in laboratory approaches. Under harsh environmental conditions, the nematode model organisms Caenorhabditis elegans and Pristionchus pacificus arrest their development and induce the formation of stress-resistant dauer larvae in response to dauer pheromones, representing a key example of phenotypic plasticity. Previous studies have indicated that in P. pacificus, many wild isolates show cross-preference of dauer pheromones and compete for access to a limited food source. When investigating the genetic mechanisms underlying this intraspecific competition, we recently discovered that the orphan gene dauerless (dau-1) controls dauer formation by copy number variation. Our results show that dau-1 acts in parallel to or downstream of steroid hormone signaling but upstream of the nuclear hormone receptor daf-12, suggesting that DAU-1 represents a novel inhibitor of DAF-12. Phylogenetic analysis reveals that the observed copy number variation is part of a complex series of gene duplication events that occurred over short evolutionary time scales. Here, we comment on the incorporation of novel or fast-evolving genes into conserved genetic networks as a common principle for the evolution of phenotypic plasticity and intraspecific competition. We discuss the possibility that orphan genes might often function in the regulation and execution of ecologically relevant traits. Given that only few ecological processes can be studied in model organisms, the function of such genes might often go unnoticed, explaining the large number of uncharacterized genes in model system genomes.
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In the realm of drug delivery, carbon nanotubes (CNTs) have gained tremendous attention as promising nanocarriers, owing to their distinct characteristics, such as high surface area, enhanced cellular uptake and the possibility to be easily conjugated with many therapeutics, including both small molecules and biologics, displaying superior efficacy, enhanced specificity and diminished side effects. While most CNT-based drug delivery system (DDS) had been engineered to combat cancers, there are also emerging reports that employ CNTs as either the main carrier or adjunct material for the delivery of various non-anticancer drugs. In this review, the delivery of small molecule drugs is expounded, with special attention paid to the current progress of in vitro and in vivo research involving CNT-based DDSs, before finally concluding with some consideration on inevitable complications that hamper successful disease intervention with CNTs.
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Sistemas de Liberação de Medicamentos , Desenho de Fármacos , Nanotubos de Carbono/química , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Antineoplásicos/farmacologia , Portadores de Fármacos/química , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/patologiaRESUMO
Despite incomplete understanding to its mechanism of action, dexrazoxane (DEX) is still the only clearly effective cardioprotectant against chronic anthracycline (ANT) cardiotoxicity. However, its clinical use is currently restricted to patients exceeding significant ANT cumulative dose (300mg/m(2)), although each ANT cycle may induce certain potentially irreversible myocardial damage. Therefore, the aim of this study was to compare early and delayed DEX intervention against chronic ANT cardiotoxicity and study the molecular events involved. The cardiotoxicity was induced in rabbits with daunorubicin (DAU; 3mg/kg/week for 10 weeks); DEX (60mg/kg) was administered either before the 1st or 7th DAU dose (i.e. after ≈300mg/m(2) cumulative dose). While both DEX administration schedules prevented DAU-induced premature deaths and severe congestive heart failure, only the early intervention completely prevented the left ventricular dysfunction, myocardial morphological changes and mitochondrial damage. Further molecular analyses did not support the assumption that DEX cardioprotection is based and directly proportional to protection from DAU-induced oxidative damage and/or deletions in mtDNA. Nevertheless, DAU induced significant up-regulation of heme oxygenase 1 pathway while heme synthesis was inversely regulated and both changes were schedule-of-administration preventable by DEX. Early and delayed DEX interventions also differed in ability to prevent DAU-induced down-regulation of expression of mitochondrial proteins encoded by both nuclear and mitochondrial genome. Hence, the present functional, morphological as well as the molecular data highlights the enormous cardioprotective effects of DEX and provides novel insights into the molecular events involved. Furthermore, the data suggests that currently recommended delayed intervention may not be able to take advantage of the full cardioprotective potential of the drug.