RESUMO
BACKGROUND: Norepinephrine (NE) is a cornerstone drug in the management of septic shock, with its dose being used clinically as a marker of disease severity and as mortality predictor. However, variations in NE dose reporting either as salt formulations or base molecule may lead to misinterpretation of mortality risks and hinder the process of care. METHODS: We conducted a retrospective analysis of the MIMIC-IV database to assess the impact of NE dose reporting heterogeneity on mortality prediction in a cohort of septic shock patients. NE doses were converted from the base molecule to equivalent salt doses, and their ability to predict 28-day mortality at common severity dose cut-offs was compared. RESULTS: 4086 eligible patients with septic shock were identified, with a median age of 68 [57-78] years, an admission SOFA score of 7 [6-10], and lactate at diagnosis of 3.2 [2.4-5.1] mmol/L. Median peak NE dose at day 1 was 0.24 [0.12-0.42] µg/kg/min, with a 28-day mortality of 39.3%. The NE dose showed significant heterogeneity in mortality prediction depending on which formulation was reported, with doses reported as bitartrate and tartrate presenting 65 (95% CI 79-43)% and 67 (95% CI 80-47)% lower ORs than base molecule, respectively. This divergence in prediction widened at increasing NE doses. When using a 1 µg/kg/min threshold, predicted mortality was 54 (95% CI 52-56)% and 83 (95% CI 80-87)% for tartrate formulation and base molecule, respectively. CONCLUSIONS: Heterogeneous reporting of NE doses significantly affects mortality prediction in septic shock. Standardizing NE dose reporting as base molecule could enhance risk stratification and improve processes of care. These findings underscore the importance of consistent NE dose reporting practices in critical care settings.
Assuntos
Norepinefrina , Choque Séptico , Humanos , Choque Séptico/tratamento farmacológico , Choque Séptico/mortalidade , Idoso , Feminino , Masculino , Estudos Retrospectivos , Pessoa de Meia-Idade , Norepinefrina/uso terapêutico , Norepinefrina/administração & dosagem , Vasoconstritores/uso terapêutico , Vasoconstritores/administração & dosagem , Estudos de CoortesRESUMO
Membrane cholesterol-rich domains have been shown to be important for regulating a range of membrane protein activities. Low-density lipoprotein receptor (LDLR)-mediated internalization of cholesterol-rich LDL particles is tightly regulated by feedback mechanisms involving intracellular sterol sensors. Since LDLR plays a role in maintaining cellular cholesterol homeostasis, we explore the role that membrane domains may have in regulating LDLR activity. We expressed a fluorescent LDLR-mEGFP construct in HEK293T cells and imaged the unligated receptor or bound to an LDL/DiI fluorescent ligand using total internal reflection fluorescence microscopy. We studied the receptor's spatiotemporal dynamics using fluorescence fluctuation analysis methods. Image cross correlation spectroscopy reveals a lower LDL-to-LDLR binding fraction when membrane cholesterol concentrations are augmented using cholesterol esterase, and a higher binding fraction when the cells are treated with methyl-ß-cyclodextrin) to lower membrane cholesterol. This suggests that LDLR's ability to metabolize LDL particles is negatively correlated to membrane cholesterol concentrations. We then tested if a change in activity is accompanied by a change in membrane localization. Image mean-square displacement analysis reveals that unligated LDLR-mEGFP and ligated LDLR-mEGFP/LDL-DiI constructs are transiently confined on the cell membrane, and the size of their confinement domains increases with augmented cholesterol concentrations. Receptor diffusion within the domains and their domain-escape probabilities decrease upon treatment with methyl-ß-cyclodextrin, consistent with a change in receptor populations to more confined domains, likely clathrin-coated pits. We propose a feedback model to account for regulation of LDLR within the cell membrane: when membrane cholesterol concentrations are high, LDLR is sequestered in cholesterol-rich domains. These LDLR populations are attenuated in their efficacy to bind and internalize LDL. However, when membrane cholesterol levels drop, LDL has a higher binding affinity to its receptor and the LDLR transits to nascent clathrin-coated domains, where it diffuses at a slower rate while awaiting internalization.
Assuntos
Colesterol , Receptores de LDL , Humanos , Colesterol/metabolismo , Clatrina/metabolismo , Fluorescência , Células HEK293 , Lipoproteínas LDL/metabolismo , Receptores de LDL/metabolismoRESUMO
The mechanisms by which angiotensin II type 1 receptor is distributed and the diffusional pattern in the plasma membrane (PM) remain unclear, despite their crucial role in cardiovascular homeostasis. In this work, we obtained quantitative information of angiotensin II type 1 receptor (AT1R) lateral dynamics as well as changes in the diffusion properties after stimulation with ligands in living cells using photoactivated localization microscopy (PALM) combined with image spatial-temporal correlation analysis. To study the organization of the receptor at the nanoscale, expansion microscopy (ExM) combined with PALM was performed. This study revealed that AT1R lateral diffusion increased after binding to angiotensin II (Ang II) and the receptor diffusion was transiently confined in the PM. In addition, ExM revealed that AT1R formed nanoclusters at the PM and the cluster size significantly decreased after Ang II treatment. Taking these results together suggest that Ang II binding and activation cause reorganization and changes in the dynamics of AT1R at the PM.
Assuntos
Angiotensina II , Receptor Tipo 1 de Angiotensina , Receptor Tipo 1 de Angiotensina/metabolismo , Angiotensina II/farmacologia , Angiotensina II/metabolismo , Microscopia , Membrana Celular/metabolismoRESUMO
Capillary refill time (CRT), a costless and widely available tool, has emerged as a promising target to guide septic shock resuscitation. However, it has yet to gain universal acceptance due to its potential inter-observer variability. Standardization of CRT assessment may minimize this problem, but few studies have compared this approach with techniques that directly assess skin blood flow (SBF). Our objective was to determine if an abnormal CRT is associated with impaired SBF and microvascular reactivity in early septic shock patients. Twelve septic shock patients were subjected to multimodal perfusion and hemodynamic monitoring for 24 h. Three time-points (0, 1, and 24 h) were registered for each patient. SBF was measured by laser doppler. We performed a baseline SBF measurement and two microvascular reactivity tests: one with a thermal challenge at 44 °C and other with a vascular occlusion test. Ten healthy volunteers were evaluated to obtain reference values. The patients (median age 70 years) exhibited a 28-day mortality of 50%. Baseline CRT was 3.3 [2.7-7.3] seconds. In pooled data analysis, abnormal CRT presented a significantly lower SBF when compared to normal CRT [44 (13.3-80.3) vs 193.2 (99.4-285) APU, p = 0.0001]. CRT was strongly associated with SBF (R2 0.76, p < 0.0001). An abnormal CRT also was associated with impaired thermal challenge and vascular occlusion tests. Abnormal CRT values observed during early septic shock resuscitation are associated with impaired skin blood flow, and abnormal skin microvascular reactivity. Future studies should confirm these results.
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Choque Séptico , Humanos , Idoso , Microcirculação , Projetos Piloto , Hemodinâmica/fisiologia , Ressuscitação/métodosRESUMO
The translation of mRNAs into proteins serves as a critical regulatory event in gene expression. In the context of cancer, deregulated translation is a hallmark of transformation, promoting the proliferation, survival, and metastatic capabilities of cancer cells. The best-studied factor involved in the translational control of cancer is the eukaryotic translation initiation factor 4E (eIF4E). We and others have shown that eIF4E availability and phosphorylation promote metastasis in mouse models of breast cancer by selectively augmenting the translation of mRNAs involved in invasion and metastasis. However, the impact of translational control in cell types within the tumor microenvironment (TME) is unknown. Here, we demonstrate that regulatory events affecting translation in cells of the TME impact cancer progression. Mice bearing a mutation in the phosphorylation site of eIF4E (S209A) in cells comprising the TME are resistant to the formation of lung metastases in a syngeneic mammary tumor model. This is associated with reduced survival of prometastatic neutrophils due to decreased expression of the antiapoptotic proteins BCL2 and MCL1. Furthermore, we demonstrate that pharmacological inhibition of eIF4E phosphorylation prevents metastatic progression in vivo, supporting the development of phosphorylation inhibitors for clinical use.
Assuntos
Neoplasias da Mama/patologia , Fator de Iniciação 4E em Eucariotos/genética , Fator de Iniciação 4E em Eucariotos/metabolismo , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/secundário , Neutrófilos/metabolismo , Biossíntese de Proteínas , Microambiente Tumoral , Motivos de Aminoácidos , Animais , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Fator de Iniciação 4E em Eucariotos/química , Feminino , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos SCID , Proteína de Sequência 1 de Leucemia de Células Mieloides/genética , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Metástase Neoplásica , Fosforilação , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismoRESUMO
Leucoptera sinuella is a leaf-miner moth present in several regions in the world, which has been recently introduced into Chile. The larvae feed exclusively on the leaves of poplar and willow trees, and the damage caused by the feeding behavior poses a threat to the wood-producing industry. Besides, L. sinuella larvae invade nearby orchards for pupation, causing rejections in Chilean fresh fruit for export. Here we report the identification of the female-produced sex pheromone of L. sinuella as a first step towards the development of pheromone-based methods for pest management of this species. First, we analyzed hexane extracts of the abdominal glands of virgin females by gas chromatography coupled with mass spectrometry and identified the major compound in these extracts to be 3,7-dimethylpentadecane, while minor compounds in the extracts proved to be 3,7-dimethyltetradecane and 7-methylpentadecane. Structure assignments were carried out by comparison of retention times and mass spectra of the natural products with those of authentic reference samples. Second, we conducted field tests, which showed that traps baited with synthetic 3,7-dimethylpentadecane were significantly attractive to males in a dose-dependent response. Our results also showed that a mixture of 3,7-dimethylpentadecane, 3,7-dimethyltetradecane, and 7-methylpentadecane in proportions similar to those found in gland extracts was the most attractive lure.
Assuntos
Lepidópteros/fisiologia , Populus/parasitologia , Salix/parasitologia , Atrativos Sexuais/química , Animais , Feminino , Folhas de Planta/parasitologiaRESUMO
Micro-RNAs (miRNAs) have emerged as novel gene expression regulators. Recent evidence strongly suggests a role for miRNAs in a large variety of cancer-related pathways. Different studies have shown that 18.7 to 37% of all human miRNA genes are clustered. miR-17-92 polycistronic cluster overexpression is associated with human hematolymphoid and solid malignancies including breast cancer (BC). Here, we report the identification of rs770419845, a rare 6 bp deletion located within the polycistronic miR-17-92 cluster, in two first-degree relatives from a Chilean family with familial BC and negative for point mutations in BRCA 1/2 genes. The deletion was identified by Sanger sequencing when 99 BRCA1/2 mutation-negative BC cases with a strong family history were initially screened. In silico analysis predicts that rs770419845 affects the secondary structure and stability of the pre-miR-17-pre-miR-18 region and the entire 17-92 cluster. The deletion was screened in 458 high-risk BRCA1/2-negative Chilean families and 480 controls. rs770419845 was not detected in any control but identified in a single family with two cases of BC and other cancers. Both BC cases, the mother and her daughter, carried the deletion. Based on bioinformatic analyses, the location of the deletion and its low frequency, we presume rs770419845 may be a pathogenic variant. Functional studies are needed to support this hypothesis.
Assuntos
Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , Mutação em Linhagem Germinativa , Heterozigoto , MicroRNAs/genética , Família Multigênica , Deleção de Sequência , Adulto , Idoso , Sequência de Bases , Chile , Família , Feminino , Humanos , Pessoa de Meia-Idade , Conformação de Ácido Nucleico , Linhagem , RNA Longo não Codificante , Análise de Sequência de DNARESUMO
Breast cancer (BC) is the most common malignancy among women worldwide. A major advance in the understanding of the genetic etiology of BC was the discovery of BRCA1 and BRCA2 (BRCA1/2) genes, which are considered high-penetrance BC genes. In non-carriers of BRCA1/2 mutations, disease susceptibility may be explained of a small number of mutations in BRCA1/2 and a much higher proportion of mutations in ethnicity-specific moderate- and/or low-penetrance genes. In Central and South American populations, studied have focused on analyzing the distribution and prevalence of BRCA1/2 mutations and other susceptibility genes that are scarce in Latin America as compared to North America, Europe, Australia, and Israel. Thus, the aim of this review is to present the current state of knowledge regarding pathogenic BRCA variants and other BC susceptibility genes. We conducted a comprehensive review of 47 studies from 12 countries in Central and South America published between 2002 and 2017 reporting the prevalence and/or spectrum of mutations and pathogenic variants in BRCA1/2 and other BC susceptibility genes. The studies on BRCA1/2 mutations screened a total of 5956 individuals, and studies on susceptibility genes analyzed a combined sample size of 11,578 individuals. To date, a total of 190 different BRCA1/2 pathogenic mutations in Central and South American populations have been reported in the literature. Pathogenic mutations or variants that increase BC risk have been reported in the following genes or genomic regions: ATM, BARD1, CHECK2, FGFR2, GSTM1, MAP3K1, MTHFR, PALB2, RAD51, TOX3, TP53, XRCC1, and 2q35.
Assuntos
Neoplasias da Mama/genética , Genes BRCA1 , Genes BRCA2 , Predisposição Genética para Doença/genética , Mutação , Neoplasias Ovarianas/genética , América Central , Feminino , Humanos , América do SulRESUMO
BACKGROUND: MicroRNAs (miRNAs) are a novel class of endogenous, non-coding, single-stranded RNAs capable of regulating gene expression by suppressing translation or degrading mRNAs. Single nucleotide polymorphisms (SNP) can alter miRNA expression, resulting in diverse functional consequences. Previous studies have examined the association of miRNA SNPs with breast cancer (BC) susceptibility. The contribution of miRNA gene variants to BC susceptibility in South American women had been unexplored. Our study evaluated the association of the SNPs rs895819 in pre-miR27a, rs11614913 in pre-miR-196a2, rs6505162 in pre-miR-423, rs4919510 in miR-608, and rs2682818 in pre-mir-618 with familial BC and early-onset non-familial BC in non-carriers of BRCA1/2 mutations from a South American population. RESULTS: We evaluated the association of five SNPs with BC risk in 440 cases and 807 controls. Our data do not support an association of rs11614913:C > T and rs4919510:C > G with BC risk. The rs6505162:C > A was significantly associated with increased risk of familial BC in persons with a strong family history of BC (OR = 1.7 [95 % CI 1.0-2.0] p = 0.05). The rs2682818:C > A genotype C/A is associated with an increased BC risk in non-familial early-onset BC. For the rs895819:A > G polymorphism, the genotype G/G is significantly associated with reduced BC risk in families with a moderate history of BC (OR = 0.3 [95 % CI 0.1-0.8] p = 0.01). CONCLUSIONS: The contribution of variant miRNA genes to BC in South American women had been unexplored. Our findings support the following conclusions: a) rs6505162:C > A in pre-miR-423 increases risk of familial BC in families with a strong history of BC; b) the C/A genotype at rs2682818:C > A (pre-miR-618) increases BC risk in non-familial early-onset BC; and c) the G/G genotype at rs895819:A > G (miR-27a) reduces BC risk in families with a moderate history of BC.
Assuntos
Neoplasias da Mama/genética , Predisposição Genética para Doença/genética , MicroRNAs/genética , Polimorfismo de Nucleotídeo Único , Precursores de RNA/genética , Feminino , Frequência do Gene , Humanos , Pessoa de Meia-Idade , Mutação , América do SulRESUMO
BACKGROUND: Germline mutations in PALB2 have been identified in approximately 1% of familial breast cancer (BC) in several populations. Nevertheless its contribution in the South-American population is unknown. The goal of this study was to determine the prevalence of PALB2 mutations in the Chilean population. METHODS: 100 Chilean BRCA1/2-negatives familial BC cases were included for the PALB2 mutation analysis. We use conformational sensitive gel electrophoresis and direct sequencing. Using a case-control design, we studied the identified variants in 436 BC cases and 809 controls to evaluate their possible association with BC risk. RESULTS: No pathogenic mutations were detected. We identified three variants, the variant c.1861C > A not previously described was found in one of the 436 cases and none of the 809 controls. The bioinformatic analyses indicate that this variant probably is not pathogenic. PALB2 c.1676A > G (rs152451A/G) and c.2993C > T (rs45551636C/T) variants were significantly associated with increased BC risk only in cases with a strong family history of BC (OR = 1.9 [CI 95% 1.3-2.8] p < 0.01 and OR = 3.3 [CI 95% 1.4-7.3] p < 0.01, respectively). The rs152451A/G-rs45551636C/T composite genotype produce increase of the BC risk in cases with a strong family history of BC (OR = 3.6 [CI 95% 1.7-8.0] p = 0.003). The rs152451-G/rs45551636-C and rs152451-G/rs45551636-T haplotypes were associated with an increased BC risk only in cases with a strong family history of BC (OR = 1.6 [CI 95% 1.0-2.5] p = 0.05 and OR = 3.7 [CI 95% 1.8-7.5] p < 0.001, respectively). CONCLUSION: Our results suggest that PALB2 c.1676A > G and c.2993C > T play roles in BC risk in women with a strong family history of BC.
Assuntos
Predisposição Genética para Doença , Variação Genética , Proteínas Nucleares/genética , Proteínas Supressoras de Tumor/genética , Adulto , Idade de Início , Alelos , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/genética , Estudos de Casos e Controles , Chile/epidemiologia , Biologia Computacional , Análise Mutacional de DNA , Proteína do Grupo de Complementação N da Anemia de Fanconi , Feminino , Frequência do Gene , Genótipo , Haplótipos , Humanos , Pessoa de Meia-Idade , Mutação , Vigilância da População , Prevalência , Risco , Adulto JovemRESUMO
Chagas disease is a neglected tropical disease, which affects an estimate of 6-7 million people worldwide. Chagas disease is caused by Trypanosoma cruzi, which is a eukaryotic flagellate unicellular organism. At the primary infection sites, these parasites are phagocytized by macrophages, which produce reactive oxygen species (ROS) in response to the infection with T. cruzi. The ROS produce damage to the host tissues; however, macrophage-produced ROS is also used as a signal for T. cruzi proliferation. At the later stages of infection, mitochondrial ROS is produced by the infected cardiomyocytes that contribute to the oxidative damage, which persists at the chronic stage of the disease. The oxidative damage leads to a functional impairment of the heart. In this review article, we will discuss the mechanisms by which T. cruzi is able to deal with the oxidative stress and how this helps the parasite growth at the acute phase of infection and how the oxidative stress affects the cardiomyopathy at the chronic stage of the Chagas disease. We will describe the mechanisms used by the parasite to deal with ROS and reactive nitrogen species (RNS) through the trypanothione and the mechanisms used to repair the damaged DNA. Also, a description of the events produced by ROS at the acute and chronic stages of the disease is presented. Lastly, we discuss the benefits of ROS for T. cruzi growth and proliferation and the possible mechanisms involved in this phenomenon. Hypothesis is put forward to explain the molecular mechanisms by which ROS triggers parasite growth and proliferation and how ROS is able to produce a long persisting damage on cardiomyocytes even in the absence of the parasite.
Assuntos
Doença de Chagas/metabolismo , Macrófagos/metabolismo , Miócitos Cardíacos/metabolismo , Espécies Reativas de Nitrogênio/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Trypanosoma cruzi/metabolismo , Animais , Doença de Chagas/patologia , Doença Crônica , Humanos , Macrófagos/parasitologia , Macrófagos/patologia , Miócitos Cardíacos/parasitologia , Miócitos Cardíacos/patologia , OxirreduçãoRESUMO
INTRODUCTION: Laparoscopic bariatric surgery (LBS) in liver end-stage organ disease has been proven to improve organ function and patients' symptoms. A series of LBS in patients with cirrhosis have shown good results in weight loss, but increased risk of complications. Current literature is based on clinical series. This paper aims to compare LBS (69% gastric bypass) between patients with cirrhosis and without cirrhosis. METHODS: We conducted a retrospective 1:3 matched case-control study including bariatric patients with cirrhosis and without cirrhosis. Demographics, operative variables, postoperative complications, long-term weight loss, and comorbidity resolution were compared between groups. RESULTS: Sixteen Child A patients were included in the patients with cirrhosis (PC) group and 48 in patients without cirrhosis (control) group. Mean age was 50 years; preoperative BMI was 39 ± 6.8 kg/m2. Laparoscopic gastric bypass and laparoscopic sleeve gastrectomy were performed in 69% and 31%, respectively. Follow-up was 81% at 2 years for both groups. PC group had a higher rate of overall (31% vs. 6%; p < 0.05) and severe (Clavien-Dindo ≥ III; 13% vs. 0%; p = 0.013) complications than that of the control group. Mean %EWL of PC at 2 years of follow-up was 84.9%, without differences compared with that of the control group (83.1%). Comorbidity remission in PC was 14%, 50%, and 85% for hypertension, type 2 diabetes, and dyslipidemia, respectively. Patients without cirrhosis had a higher resolution rate of hypertension (65% vs. 14%, p = 0.03). CONCLUSION: LBS is effective for weight loss and comorbidity resolution in patients with obesity and Child A liver cirrhosis. However, these results are accompanied by significantly increased risk of complications.
Assuntos
Cirurgia Bariátrica , Diabetes Mellitus Tipo 2 , Derivação Gástrica , Laparoscopia , Obesidade Mórbida , Estudos de Casos e Controles , Criança , Diabetes Mellitus Tipo 2/complicações , Gastrectomia , Humanos , Cirrose Hepática/epidemiologia , Pessoa de Meia-Idade , Obesidade Mórbida/cirurgia , Estudos Retrospectivos , Resultado do TratamentoRESUMO
The genetic variations responsible for tumorigenesis are called driver mutations. In breast cancer (BC), two studies have demonstrated that germline mutations in driver genes linked to sporadic tumors may also influence BC risk. The present study evaluates the association between SNPs and SNP-SNP interaction in driver genes TTN (rs10497520), TBX3 (rs2242442), KMT2D (rs11168827), and MAP3K1 (rs702688 and rs702689) with BC risk in BRCA1/2-negative Chilean families. The SNPs were genotyped in 489 BC cases and 1078 controls by TaqMan Assay. Our data do not support an association between rs702688: A>G or rs702689: G>A and BC risk. The rs10497520-T allele was associated with a decreased risk in patients with family history of BC or early-onset BC (OR = 0.6, p < 0.0001 and OR = 0.7, p = 0.05, respectively). rs2242442-G was associated with a protective effect and rs11168827-C was associated with increased BC risk in families with a strong history of BC (OR = 0.6, p = 0.02 and OR = 1.4, p = 0.05, respectively). As rs10497520-T and rs2242442-G seemed to protect against BC risk, we then evaluated their combined effect. Familial BC risk decreased in a dose-dependent manner with the protective allele count, reflecting an additive effect (p-trend < 10-4). To our knowledge, this is the first association study of BC driver gene germline variations in a Chilean population.
RESUMO
Breast cancer (BC) is one of the most frequent tumors affecting women worldwide. microRNAs (miRNAs) single-nucleotide polymorphisms (SNPs) likely contribute to BC susceptibility. We evaluated the association of five SNPs with BC risk in non-carriers of the BRCA1/2-mutation from a South American population. The SNPs were genotyped in 440 Chilean BRCA1/2-negative BC cases and 1048 controls. Our data do not support an association between rs2910164:G>C or rs3746444:A>G and BC risk. The rs12975333:G>T is monomorphic in the Chilean population. The pre-miR-605 rs2043556-C allele was associated with a decreased risk of BC, both in patients with a strong family history of BC and in early-onset non-familial BC (Odds ratio (OR) = 0.5 [95% confidence interval (CI) 0.4â»0.9] p = 0.006 and OR = 0.6 [95% CI 0.5â»0.9] p = 0.02, respectively). The rs4541843-T allele is associated with increased risk of familial BC. This is the first association study on rs4541843 and BC risk. Previously, we showed that the TOX3-rs3803662:C>T was significantly associated with increased risk of familial BC. Given that TOX3 mRNA is a target of miR-182, and that both the TOX3 rs3803662-T and pri-miR-182 rs4541843-T alleles are associated with increased BC risk, we evaluated their combined effect. Risk of familial BC increased in a dose-dependent manner with the number of risk alleles (p-trend = 0.0005), indicating an additive effect.
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Studies have demonstrated the efficacy of pyrazinamide (PZA) against stages of the Leishmania parasite that causes cutaneous leishmaniasis. Although PZA is widely distributed in most body fluids and tissues, the amount of drug reaching the skin is unknown. This study aimed to investigate the pharmacokinetics of PZA in rat dermal tissue by dermal microdialysis. Skin pharmacokinetics was assessed by implanting a linear microdialysis probe in the dermis of ten rats. In addition, blood samples were collected to assess plasma pharmacokinetics. Unbound microdialysate (N = 280) and plasma (N = 120) concentrations following single intravenous doses of 25 mg/kg or 50 mg/kg PZA were quantified by a validated HPLC method. Probe calibration was performed by retrodialysis. Non-compartmental analysis and non-linear mixed-effects modelling were performed using WinNonlin and NONMEM v.7.3. PZA rapidly permeated into the dermis and reached high levels, with mean maximum concentrations (Cmax) of 22.4 ± 7.1 µg/mL and 48.6 ± 17.3 µg/mL for the two doses studied. PZA showed significant distribution to the skin (fAUCdermal/fAUCplasma = 0.82 ± 0.31 and 0.84 ± 0.25 for 25 mg/kg and 50 mg/kg doses, respectively). Active unbound concentrations in dermal tissue reached lower levels than free plasma concentrations, indicating that free PZA levels in plasma were in equilibrium with tissue levels. These results showed equivalent unbound drug tissue concentrations and corresponding unbound plasma levels. This study shows that PZA distributes rapidly into dermal interstitial fluid space in rats and therefore may be a potential agent in the treatment of cutaneous leishmaniasis.
Assuntos
Antiparasitários/sangue , Antiparasitários/farmacocinética , Leishmaniose Cutânea/tratamento farmacológico , Microdiálise/métodos , Pirazinamida/sangue , Pirazinamida/farmacocinética , Pele/química , Animais , Leishmania/efeitos dos fármacos , Leishmaniose Cutânea/parasitologia , Masculino , Ratos , Ratos Wistar , Pele/efeitos dos fármacos , Pele/parasitologiaRESUMO
This work explores the use of magnetic resonance imaging (MRI) for nondestructive determination of wood characteristics and for 3D wood modeling. In this context, one of the applications under development is the automatic recognition and reconstruction of rings from transversal images obtained from MRI scanners. The algorithm analyzes a set of transversal MRI images, detecting and reconstructing growth ring edges. The information generated is then interpolated in order to obtain an accurate 3D picture of the log and its fundamental constituents (individual rings, knots, defects, etc). Results also show that the technique has potential for defect recognition, providing a powerful tool for future developments in wood analysis. The results are encouraging and further research is needed to develop automatic detection not only of rings, but also of different types of defects that are of paramount importance in the sawmill and plywood industries.
Assuntos
Imageamento por Ressonância Magnética , Pinus/crescimento & desenvolvimento , Algoritmos , Agricultura Florestal/métodos , Processamento de Imagem Assistida por ComputadorRESUMO
Recent advances in nanotechnology and nanobiotechnology have contributed to the development of nanomaterials, able to be used as drug carriers, probes, targets or cytostatic drugs by itself. Nanomedicine is now the leading area in nanotechnology where a large number and types of nanoparticles (NPs) has been developed and several are already in the clinical practice. Chemotherapy is one of the most widely used strategies to treat cancer. Most chemotherapeutic agents have poor solubility, low bioavailability, and are formulated with toxic solvents. NPs have been designed to overcome the lack of specificity of chemotherapeutic agents as well to improve circulation time in blood, taking advantages on tumor cells characteristics. In immunology, recent advances regarding the activation of the innate immune system artificially enhanced by NPs functionalized with immune-stimulators open a new window as novel methods in vaccines. Also, viruses and virus-like particles (VLPs) engineered to stimulate immune response against their similar virus or as molecular platforms for the presentation of foreign epitopes have been described. In this review we focused in the use of different types of NPs in oncology and immunology, pinpointing the main novelties regarding their development and use of nanotechnology in a broad array of applications, ranging from tumor diagnostics, immune-modulation up to cancer therapeutics.
Assuntos
Antineoplásicos , Fatores Imunológicos , Nanopartículas , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Dendrímeros/química , Grafite/química , Humanos , Fatores Imunológicos/administração & dosagem , Fatores Imunológicos/química , Fatores Imunológicos/uso terapêutico , Lipossomos , Nanomedicina , Nanopartículas/administração & dosagem , Nanopartículas/química , Nanopartículas/uso terapêutico , Nanotubos de Carbono/química , Neoplasias/tratamento farmacológico , Dióxido de Silício/químicaRESUMO
Breast cancer (BC) is the most common malignancy among women worldwide. A major advance in the understanding of the genetic etiology of BC was the discovery of BRCA1 and BRCA2 (BRCA1/2) genes, which are considered high-penetrance BC genes. In non-carriers of BRCA1/2 mutations, disease susceptibility may be explained of a small number of mutations in BRCA1/2 and a much higher proportion of mutations in ethnicity-specific moderate- and/or low-penetrance genes. In Central and South American populations, studied have focused on analyzing the distribution and prevalence of BRCA1/2 mutations and other susceptibility genes that are scarce in Latin America as compared to North America, Europe, Australia, and Israel. Thus, the aim of this review is to present the current state of knowledge regarding pathogenic BRCA variants and other BC susceptibility genes. We conducted a comprehensive review of 47 studies from 12 countries in Central and South America published between 2002 and 2017 reporting the prevalence and/or spectrum of mutations and pathogenic variants in BRCA1/2 and other BC susceptibility genes. The studies on BRCA1/2 mutations screened a total of 5956 individuals, and studies on susceptibility genes analyzed a combined sample size of 11,578 individuals. To date, a total of 190 different BRCA1/2 pathogenic mutations in Central and South American populations have been reported in the literature. Pathogenic mutations or variants that increase BC risk have been reported in the following genes or genomic regions: ATM, BARD1, CHECK2, FGFR2, GSTM1, MAP3K1, MTHFR, PALB2, RAD51, TOX3, TP53, XRCC1, and 2q35.