Protective Effects of Quercetin on Livers from Mice Exposed to Long-Term Cigarette Smoke.

Cigarette smoke is highly toxic, and it can promote increased production of reactive species and inflammatory response and leads to liver diseases. Quercetin is a flavonoid that displays antioxidant and anti-inflammatory activities in liver diseases. This study aimed at evaluating the protective effects of quercetin on livers from mice exposed to long-term cigarette smoke exposure. Male C57BL/6 mice were divided into five groups: control (CG), vehicle (VG), quercetin (QG), cigarette smoke (CSG), quercetin, and cigarette smoke (QCSG). CSG and QCSG were exposed to cigarette smoke for sixty consecutive days; at the end of the exposures, all animals were euthanized. Mice that received quercetin daily and were exposed to cigarette smoke showed a reduced influx of inflammatory cells, oxidative stress, inflammatory reaction, and histopathological changes in the liver, compared to CSG. These results suggest that quercetin may be an effective adjuvant for treating damage to the liver due to cigarette smoke exposure.

Contribution of GO System Glycosylases to Mutation Prevention in Caulobacter crescentus.

8-oxo-7,8-dihydroguanine, commonly referred to as 8-oxoG, is considered one of the most predominant oxidative lesions formed in DNA. Due to its ability to pair with adenines in its syn configuration, this lesion has a strong mutagenic potential in both eukaryotes and prokaryotes. Escherichia coli cells are endowed with the GO system, which protects them from the mutagenic properties of this lesion when formed both in cellular DNA and the nucleotide pool. MutY and MutM (Fpg) DNA glycosylases are crucial components of the GO system. A strong mutator phenotype of the Escherichia coli mutM mutY double mutant underscores the importance of 8-oxoG repair for genomic stability. Here, we report that in Caulobacter crescentus, a widely studied alpha-proteobacterium with a GC-rich genome, the combined lack of MutM and MutY glycosylases produces a more modest mutator phenotype when compared to E. coli. Genetic analysis indicates that other glycosylases and other repair pathways do not act synergistically with the GO system for spontaneous mutation prevention. We also show that there is not a statistically significant difference in the spontaneous levels 8-oxodGuo in E. coli and C. crescentus, suggesting that other yet to be identified differences in repair or replication probably account for the differential importance of the GO system between these two species. Environ. Mol. Mutagen. 61:246-255, 2020. © 2019 Wiley Periodicals, Inc.

Association of EGLN1 gene with high aerobic capacity of Peruvian Quechua at high altitude.

Highland native Andeans have resided at altitude for millennia. They display high aerobic capacity (VO2max) at altitude, which may be a reflection of genetic adaptation to hypoxia. Previous genomewide (GW) scans for natural selection have nominated Egl-9 homolog 1 gene (EGLN1) as a candidate gene. The encoded protein, EGLN1/PHD2, is an O2 sensor that controls levels of the Hypoxia Inducible Factor-α (HIF-α), which regulates the cellular response to hypoxia. From GW association and analysis of covariance performed on a total sample of 429 Peruvian Quechua and 94 US lowland referents, we identified 5 EGLN1 SNPs associated with higher VO2max (L⋅min-1 and mL⋅min-1⋅kg-1) in hypoxia (rs1769793, rs2064766, rs2437150, rs2491403, rs479200). For 4 of these SNPs, Quechua had the highest frequency of the advantageous (high VO2max) allele compared with 25 diverse lowland comparison populations from the 1000 Genomes Project. Genotype effects were substantial, with high versus low VO2max genotype categories differing by ∼11% (e.g., for rs1769793 SNP genotype TT = 34.2 mL⋅min-1⋅kg-1 vs. CC = 30.5 mL⋅min-1⋅kg-1). To guard against spurious association, we controlled for population stratification. Findings were replicated for EGLN1 SNP rs1769793 in an independent Andean sample collected in 2002. These findings contextualize previous reports of natural selection at EGLN1 in Andeans, and support the hypothesis that natural selection has increased the frequency of an EGLN1 causal variant that enhances O2 delivery or use during exercise at altitude in Peruvian Quechua.

Is subretinal surgery feasible for a non-responsive juxtafoveal type 2 choroidal neovascular membrane?

PURPOSE: To describe the long-term outcome of a patient with multifocal choroiditis, who underwent surgical removal of a type 2 choroidal neovascular membrane employing 23 G pars plana vitrectomy. OBSERVATIONS: A 50-year-old man was treated with 3 monthly intravitreal bevacizumab injections, but despite treatment, visual acuity continued to worsen from 20/40 to 20/100, and bleeding was not receding. A minimal invasive pars plana vitrectomy was performed for surgical removal of the neovascular complex without any complicating incident. Subsequent visual acuity was 20/25 for more than eleven years. CONCLUSIONS AND IMPORTANCE: Surgical removal of choroidal neovascular membranes employing minimal invasive surgery in addition to anti-VEGF therapy, and OCT evaluation can be a viable approach for selected cases of juxtafoveal type 2 CNV.

Effects of previous carbohydrate supplementation on muscular fatigue: double-blind, randomized, placebo-controlled crossover study

Aims: The aim of this study was to examine the effects of previous carbohydrate supplementation on high-volume resistance exercise performance Methods: Twenty males physically independent adults aged ≥18 years participated in a double-blind randomized placebo-controlled crossover study. Sixty minutes before the experimental protocol, each participant ingested 0,6 g.kg of body mass-1 of carbohydrate supplementation or placebo. Maximum voluntary isometric contraction tests were performed before and after the dynamic fatigue induction protocol consisting of 10 sets of 8 repetitions of right leg knee extensors at 120º s-1. Results: Lower decrement of the isometric peak torque (p<0,001) and of the rate of torque development (p<0,001) was observed in carbohydrate supplementation after the dynamic protocol. Both concentric and eccentric peak torque differed significantly (p<0,001) between carbohydrate supplementation and placebo treatments from the second set, although the slope of the force-repetitions curve was not different between them. Additionally, the carbohydrate supplementation resulted in a lower session rating of perceived exertion (p<0,05). Conclusions: Previous carbohydrate supplementation attenuates muscle fatigue and internal load exercise in a high-volume isokinetic leg protocol.(AU)

Multivariate linear regression analysis to evaluate multiple-set performance in active and inactive individuals

Abstract Aim: To determine how EMG, anthropometric, and psychological factors, and physical activity levels affect isokinetic peak torque performance (IPT) of multiple set exercise sessions. Methods: 20 participants (27±7 years old), classified as active (A=10) and inactive (I=10), performed 10x10:40secs of maximal unilateral knee flexions and extensions at 120o.s-1. The IPT, EMG, glucose, LDH, and lactate concentrations and perceptions of pain, effort, recovery. Results: Active volunteers showed higher muscularity (52±5 vs 47±4 cm; p<0.05), PTI (262±4 vs 185±4 Nm; p<0.05), relative lower drop in performance (14±2 vs 27±3% ; p<0.05), major MDF (83±1 vs 76±1 Hz; p<0.05), lower log -Fins5 (-12.9±0.3 vs -12.7 ± 0.3 Hz; p<0.05), smaller subjective perception of effort (14.8±0.3 vs 17.0±0.3) and higher subjective perception of recovery (14.2±0.2 vs 12.3±0.3). There was a significant interaction between relative fatigue and the number of sets (F=6.18; p<0.001). Stepwise multiple regressions revealed that subjective perception of recovery best explained the fatigue level generated in the active volunteers [fatigue level= 85.084-5255(SPR)] while for body mass was the best determinant for the inactive group [fatigue level = -21.560 +1.828(BMI)]. Conclusion: Data from the present analysis suggest that physically active individuals show higher torque development and a smaller fatigability index when compared to inactive individuals. Among the fatigue models studied, it is possible that alterations in biochemical components, psychophysiological and EMG are not sensitive to the direct influence of the fatigue dynamics protocol, both in active or inactive individuals.

Applying Positive End-Expiratory Pressure During Mechanical Ventilation Causes Pulmonary Redox Imbalance and Inflammation in Rats.

BACKGROUND: Mechanical ventilation (MV) may induce or aggravate lung injury through the production of cytokines, inflammatory infiltration of neutrophils, and changes in the permeability of the alveolar-capillary barrier. The use of positive end-expiratory pressure (PEEP) helps improve gas exchanges avoiding alveolar collapse at the end of expiration. The present study aimed to analyze inflammatory response and redox imbalance in lungs of rats submitted to MV with and without PEEP. METHODS: Eighteen Wistar rats were divided into three groups: control (CG), PEEP group (PG), and zero PEEP (ZEEP) group (ZG). PG and ZG were submitted to MV for 60 min with or without PEEP, respectively. Subsequently, the animals were euthanized, and blood, bronchoalveolar lavage fluid, and lungs were collected for analyses. RESULTS: The number of neutrophils was higher in PG compared with CG. Leucocyte and neutrophil influx in bronchoalveolar lavage fluid was higher in PG compared with CG. PG showed an increase in alveolar area compared with the other groups. There were increases in the levels of chemokines, CCL3 and CCL5, in PG compared with CG. There were increases in oxidation of lipids and proteins in PG compared with other groups. There were increases in the activity of superoxide dismutase and catalase in PG compared with CG and ZG. However, there was a decrease in the ratio of glutathione to glutathione disulfide in PG compared with other groups. CONCLUSIONS: MV with PEEP caused redox imbalance and inflammation in lungs of healthy rats.

Increased mutability to fosfomycin resistance in Proteus mirabilis clinical isolates.

In the present study, we screened a collection of 77 Proteus mirabilis clinical isolates for the presence of mutators, using the frequency of both rifampicin and fosfomycin resistance mutants as markers of spontaneous mutagenesis. We found that none of the strains in our collection are mutators for the rifampicin resistance (RifR) marker. Nevertheless, a significant fraction of the isolates (17%) show high frequencies of fosfomycin resistant mutants (FosR). We show that this increased mutability to FosR correlates with a low level of resistance to Fosfomycin (MICs 8-64µg/ml). These strains also show high frequencies of single step mutants with clinically relevant FosR resistance levels (MIC ≥256µg/ml). Our findings point out to the risk of fosfomycin resistance emergence in P. mirabilis.

Evaluating Fidelity to a Modified NIATx Process Improvement Strategy for Improving HIV Services in Correctional Facilities.

In a study aimed at improving the quality of HIV services for inmates, an organizational process improvement strategy using change teams was tested in 14 correctional facilities in 8 US states and Puerto Rico. Data to examine fidelity to the process improvement strategy consisted of quantitative ratings of the structural and process components of the strategy and qualitative notes that explicate challenges in maintaining fidelity to the strategy. Fidelity challenges included (1) lack of communication and leadership within change teams, (2) instability in team membership, and (3) issues with data utilization in decision-making to implement improvements to services delivery.

Effect of SOS-induced levels of imuABC on spontaneous and damage-induced mutagenesis in Caulobacter crescentus.

imuABC (imuAB dnaE2) genes are responsible for SOS-mutagenesis in Caulobacter crescentus and other bacterial species devoid of umuDC. In this work, we have constructed operator-constitutive mutants of the imuABC operon. We used this genetic tool to investigate the effect of SOS-induced levels of these genes upon both spontaneous and damage-induced mutagenesis. We showed that constitutive expression of imuABC does not increase spontaneous or damage-induced mutagenesis, nor increases cellular resistance to DNA-damaging agents. Nevertheless, the presence of the operator-constitutive mutation rescues mutagenesis in a recA background, indicating that imuABC are the only genes required at SOS-induced levels for translesion synthesis (TLS) in C. crescentus. Furthermore, these data also show that TLS mediated by ImuABC does not require RecA, unlike umuDC-dependent mutagenesis in E. coli.

Molecular characterization of Caulobacter crescentus mutator strains.

Mutator strains were identified by screening random Tn5 insertion clones of Caulobacter crescentus. We identified clones with robust increases in mutation rates with Tn5 insertions in the mutY, mutS, mutL and uvrD genes, known to act in mutation-preventing pathways in Escherichia coli. Analysis of mutations in the rpoB gene revealed that in both the parental strain and mismatch repair-deficient mutants, A:T→G:C transitions predominate by a large margin over C:G→T:A. We have also investigated the role of the error-prone polymerase encoded by imuC (dnaE2) in spontaneous mutagenesis, and found that a imuC mutant strain shows mutation rates and sequences comparable to the parental strain. Our study characterizes for the first time mutator strains in a member of the alphaproteobacteria group. In spite of the limitations of using a single marker, possible reasons for the observed mutational bias are discussed in the light of the repertoire of DNA repair genes in this bacterium.

Disease Severity Prediction by Spirometry in Adults with Visceral Leishmaniasis from Minas Gerais, Brazil.

Visceral leishmaniasis (VL) is associated with interstitial pneumonitis according to histology and radiology reports. However, studies to address the functional impact on respiratory function in patients are lacking. We assessed pulmonary function using noninvasive spirometry in a cross-sectional study of hospitalized adult VL patients from Minas Gerais, Brazil, without unrelated lung conditions or acute infections. Lung conditions were graded as normal, restrictive, obstructive, or mixed patterns, according to Brazilian consensus standards for spirometry. To control for regional patterns of lung function, we compared spirometry of patients with regional paired controls. Spirometry detected abnormal lung function in most VL patients (70%, 14/20), usually showing a restrictive pattern, in contrast to regional controls and the standards for normal tests. Alterations in spirometry measurements correlated with hypoalbuminemia, the only laboratory value indicative of severity of parasitic disease. Abnormalities did not correlate with unrelated factors such as smoking or occupation. Clinical data including pulmonary symptoms and duration of therapy were also unrelated to abnormal spirometry findings. We conclude that the severity of VL is correlated with a restrictive pattern of lung function according to spirometry, suggesting that there may be interstitial lung involvement in VL. Further studies should address whether spirometry could serve as an index of disease severity in the management of VL.

Hyperoxia promotes polarization of the immune response in ovalbumin-induced airway inflammation, leading to a TH17 cell phenotype.

Previous studies have demonstrated that hyperoxia-induced stress and oxidative damage to the lungs of mice lead to an increase in IL-6, TNF-α, and TGF-ß expression. Together, IL-6 and TGF-ß have been known to direct T cell differentiation toward the TH17 phenotype. In the current study, we tested the hypothesis that hyperoxia promotes the polarization of T cells to the TH17 cell phenotype in response to ovalbumin-induced acute airway inflammation. Airway inflammation was induced in female BALB/c mice by intraperitoneal sensitization and intranasal introduction of ovalbumin, followed by challenge methacholine. After the methacholine challenge, animals were exposed to hyperoxic conditions in an inhalation chamber for 24 h. The controls were subjected to normoxia or aluminum hydroxide dissolved in phosphate buffered saline. After 24 h of hyperoxia, the number of macrophages and lymphocytes decreased in animals with ovalbumin-induced airway inflammation, whereas the number of neutrophils increased after ovalbumin-induced airway inflammation. The results showed that expression of Nrf2, iNOS, T-bet and IL-17 increased after 24 of hyperoxia in both alveolar macrophages and in lung epithelial cells, compared with both animals that remained in room air, and animals with ovalbumin-induced airway inflammation. Hyperoxia alone without the induction of airway inflammation lead to increased levels of TNF-α and CCL5, whereas hyperoxia after inflammation lead to decreased CCL2 levels. Histological evidence of extravasation of inflammatory cells into the perivascular and peribronchial regions of the lungs was observed after pulmonary inflammation and hyperoxia. Hyperoxia promotes polarization of the immune response toward the TH17 phenotype, resulting in tissue damage associated with oxidative stress, and the migration of neutrophils to the lung and airways. Elucidating the effect of hyperoxia on ovalbumin-induced acute airway inflammation is relevant to preventing or treating asthmatic patients that require oxygen supplementation to reverse the hypoxemia.

Functional characterization of two SOS-regulated genes involved in mitomycin C resistance in Caulobacter crescentus.

The SOS response is a universal bacterial regulon involved in the cellular response to DNA damage and other forms of stress. In Caulobacter crescentus, previous work has identified a plethora of genes that are part of the SOS regulon, but the biological roles of several of them remain to be determined. In this study, we report that two genes, hereafter named mmcA and mmcB, are involved in the defense against DNA damage caused by mitomycin C (MMC), but not against lesions induced by other common DNA damaging agents, such as UVC light, methyl methanesulfonate (MMS) and hydrogen peroxide. mmcA is a conserved gene that encodes a member of the glyoxalases/dioxygenases protein family, and acts independently of known DNA repair pathways. On the other hand, epistasis analysis showed that mmcB acts in the same pathway as imuC (dnaE2), and is required specifically for MMC-induced mutagenesis, but not for that induced by UV light, suggesting a role for MmcB in translesion synthesis-dependent repair of MMC damage. We show that the lack of MMC-induced mutability in the mmcB strain is not caused by lack of proper SOS induction of the imuABC operon, involved in translesion synthesis (TLS) in C. crescentus. Based on this data and on structural analysis of a close homolog, we propose that MmcB is an endonuclease which creates substrates for ImuABC-mediated TLS patches.

Challenges and Approaches to Quantitative Therapy Response Assessment in Glioblastoma Multiforme Using the Novel Apoptosis Positron Emission Tomography Tracer F-18 ML-10.

Evaluation of cancer-therapy efficacy at early time points is necessary for realizing the goal of delivering maximally effective treatment. Molecular imaging with carefully selected tracers and methodologies can provide the means for realizing this ability. Many therapies are aimed at inducing apoptosis in malignant tissue; thus, the ability to quantify apoptosis in vivo may be a fruitful approach. Apoptosis rate changes occur on a fast time scale, potentially allowing correspondingly rapid decisions regarding therapy value. However, quantification of tissue status based on apoptosis imaging is complicated by this time scale and by the spatial heterogeneity of the process. Using the positron emission tomography (PET) tracer 2-(5-fluoro-pentyl)-2-methyl-malonic acid (F-18 ML-10), we present methods of voxelwise analysis yielding quantitative measures of apoptosis changes, parametric apoptosis change images, and graphical representation of apoptotic features. A method of deformable registration to account for anatomic changes between scan time points is also demonstrated. Overall apoptotic rates deduced from imaging depend on tumor density and the specific rate of apoptosis, a situation resulting in an ambiguity in the source of observed image-based changes. The ambiguity may be resolved through multimodality imaging. An example of intracellular sodium magnetic resonance imaging coupled with F-18 ML-10 PET is provided.

Assessment of early therapy response with 18F-FLT PET in glioblastoma multiforme.

Early therapy response assessment in glioblastoma multiforme remains a challenge. Evaluation by MRI relies on changes in tumor contrast enhancement or size, which are usually not visible at early therapy response assessment times. In addition, MRI may not be reliable for early therapy response assessment if only molecular changes have occurred. PET with F-FLT, a tracer associated with cellular proliferation, has been proposed as a potential method of early therapy response assessment and is an area of active research. We present a case where early response assessment with F-FLT PET was associated with a favorable 1-year follow-up outcome.

Representing second opinion requests from primary care within the Brazilian tele-health program: international classification of primary care, second edition.

Standardization of second opinion question-answer pairs with a classification system can be used to facilitate data sharing and reuse. The Brazilian telehealth program faces the problem of representing biomedical knowledge from the primary care second opinion demands generated by rural health care teams. The objective is to determine if one of the medical classification systems has a superior ability to standardize Portuguese-language second opinion question-answer pairs. Data from 2,638 second opinions from 2010 were randomly reduced to a 264 question-answer pair data set. The semantic meaning of the question-answer pairs was manually assigned to an International Classification of Primary Care, Second edition (ICPC2) code. Eight question-answer pairs did not contain sufficient medical semantic meaning to allow for mapping to an ICPC2 code; 53 question-answer pairs did contain sufficient medical semantic meaning for mapping, however an appropriate ICPC2 code did not exist; and 203 question-answer pairs did contain sufficient medical semantic meaning for mapping to an ICPC2 code. A review of the literature indicates that there is no baseline to compare the 77% success rate against.

Alterações da histoarquitetura pulmonar de camundongos neonatos expostos à hiperóxia / Alterations in the pulmonary histoarchitecture of neonatal mice exposed to hyperoxia

OBJETIVOS: Analisar os efeitos da exposição à hiperóxia (100% de oxigênio) sobre a histoarquitetura pulmonar de camundongos neonatos. MÉTODOS: Camundongos neonatos da linhagem Balb/c foram expostos à hiperóxia (GH) (100% de oxigênio) (n = 10) em uma câmara (15 x 20 x 30 cm) por 24 horas, com fluxo de 2 L/min. O grupo controle (GC) (n = 10) foi exposto a normóxia em um mesmo tipo de câmara e pelo mesmo tempo. Após a exposição, os animais foram sacrificados por decapitação, os pulmões foram removidos para análise histológica e processados de acordo com a rotina do laboratório. Cortes de 3 µm de espessura foram corados com hematoxilina e eosina (H&E). A análise morfométrica foi realizada com o objetivo de analisar macrófagos presentes na luz alveolar, densidade de superfície (Sv) de trocas gasosas, densidade de volume (Vv) de parênquima pulmonar e áreas de atelectasias. RESULTADOS: Foi verificada diminuição do número de macrófagos alveolares (MØ) no GH (GH = 0,08±0,01 MØ/mm²; GC = 0,18±0,03 MØ/mm²; p = 0,0475), Sv de troca gasosa no GH (GH = 8,08 ± 0,12 mm² /mm³; GC = 8,65 ± 0,20 mm² /mm³; p = 0,0233), Vv de parênquima pulmonar no GH (GH = 54,7/33,5/83,5 %/mm²; GC = 75/56,7/107,9 %/mm²; p < 0.0001) quando comparado com o GC. Entretanto, houve aumento de áreas de atelectasias no GH (GH = 17,5/11,3/38,4 atelectasia/mm²; GC = 14/6,1/24,4 atelectasia/mm²; p = 0,0166) quando comparado com o GC. CONCLUSÃO: Nossos resultados indicam que a hiperóxia promoveu alterações na histoarquitetura pulmonar, aumentando áreas de atelectasia e hemorragia alveolar difusa.

OBJECTIVES: To analyze the effects of exposure to hyperoxia (100% oxygen) on the lung histoarchitecture of neonatal mice. METHODS: Neonatal Balb/c mice were exposed to hyperoxia (HG) (100% oxygen) (n = 10) in a chamber (15 x 20 x 30 cm) for 24 horas ours with a flow of 2 L/min. The control group (CG) (n = 10) was exposed to normoxia in the same type of chamber and for the same time. After exposure, the animals were euthanized by decapitation; the lungs were removed and processed for histological examination according to the laboratory routine. Three-mm thick sections were stained with hematoxylin and eosin (H&E). The morphometric analysis was performed with in order to analyze the macrophages present in the alveolar lumen, surface density (Sv) of gas exchange, volume density (Vv) of lung parenchyma, and areas of atelectasis. RESULTS: A decrease in the number of alveolar macrophages (MØ) was observed in the HG (HG = 0.08±0.01 MØ/mm², CG = 0.18±0.03 MØ/mm², p = 0.0475), Sv of gas exchange in HG (HG = 8.08±0.12 mm² /mm³, CG = 8.65±0.20 mm² /mm³, p = 0.0233), Vv of lung parenchyma in HG (HG = 54.7/33.5/83.5%/ mm²; CG = 75/56.7/107.9%/mm², p < 0.0001) when compared with the CG. However, there was an increase in areas of atelectasis in HG (HG = 17.5/11.3/38.4 atelectasis/mm², CG = 14/6.1/24.4 atelectasis/mm², p = 0.0166) when compared with the CG. CONCLUSION: The present results indicate that hyperoxia caused alterations in lung histoarchitecture, increasing areas of atelectasis and diffuse alveolar hemorrhage.