ABSTRACT
OBJECTIVES: Primaquine is essential for the radical cure of Plasmodium vivax malaria and must be metabolized into its bioactive metabolites. Accordingly, polymorphisms in primaquine-metabolizing enzymes can impact the treatment efficacy. This pioneering study explores the influence of monoamine oxidase-A (MAO-A) on primaquine metabolism and its impact on malaria relapses. METHODS: Samples from 205 patients with P. vivax malaria were retrospectively analysed by genotyping polymorphisms in MAO-A and cytochrome P450 2D6 (CYP2D6) genes. We measured the primaquine and carboxyprimaquine blood levels in 100 subjects for whom blood samples were available on the third day of treatment. We also examined the relationship between the enzyme variants and P. vivax malaria relapses in a group of subjects with well-documented relapses. RESULTS: The median carboxyprimaquine level was significantly reduced in individuals carrying low-expression MAO-A alleles plus impaired CYP2D6. In addition, this group experienced significantly more P. vivax relapses. The low-expression MAO-A status was not associated with malaria relapses when CYP2D6 had normal activity. This suggests that the putative carboxyprimaquine contribution is irrelevant when the CYP2D6 pathway is fully active. CONCLUSIONS: We found evidence that the low-expression MAO-A variants can potentiate the negative impact of impaired CYP2D6 activity, resulting in lower levels of carboxyprimaquine metabolite and multiple relapses. The findings support the hypothesis that carboxyprimaquine may be further metabolized through CYP-mediated pathways generating bioactive metabolites that act against the parasite.
Subject(s)
Antimalarials , Cytochrome P-450 CYP2D6 , Malaria, Vivax , Monoamine Oxidase , Primaquine , Adult , Female , Humans , Male , Middle Aged , Antimalarials/therapeutic use , Cytochrome P-450 CYP2D6/genetics , Cytochrome P-450 CYP2D6/metabolism , Genotype , Malaria, Vivax/drug therapy , Malaria, Vivax/genetics , Monoamine Oxidase/genetics , Plasmodium vivax/genetics , Polymorphism, Genetic , Primaquine/therapeutic use , Recurrence , Retrospective StudiesABSTRACT
OBJECTIVE: The objective was to evaluate the psychometric properties of the Mindful Eating Questionnaire (MEQ) in Brazilian subjects with type 2 diabetes mellitus (T2DM) and validate a Brazilian version of the MEQ for adults with T2DM (MEQ-DM). METHODOLOGY: Baseline data from the multicentre Nutritional Strategy for Glycaemic Control in Patients with Type 2 Diabetes Mellitus (NUGLIC) trial were used. Construct validity was assessed using exploratory factor analysis (EFA). The root mean square error of approximation (RMSEA), comparative fit index (CFI) and TuckerâLewis index (TLI) fit indices indicated the adequacy of the model. The reliability of the questionnaire was evaluated considering the different factor loadings. Criterion validity was tested by correlating the MEQ-DM with sociodemographic variables, body mass index (BMI) and physical activity levels. RESULTS: A total of 370 participants were included, who were mostly female (60.8 %) and had a median age of 61 (54-67) years. The EFA results supported the two-factor structure of the 25-item MEQ-DM: disinhibition and awareness. The results of the fit indices (RMSEA = 0.04; CFI = 0.95 and TLI = 0.94) and composite reliability (disinhibition = 0.84 and awareness = 0.81) were consistent. The criterion validity analysis indicated a significant association between MEQ-DM scores and age, sex, civil status, education level, BMI and physical activity (p < 0.05). CONCLUSION: When explored with Brazilian adults with T2DM, the MEQ-DM presented a factorial model with two dimensions: disinhibition and awareness. This model must be confirmed in future studies with Brazilians with T2DM.
Subject(s)
Diabetes Mellitus, Type 2 , Eating , Mindfulness , Aged , Female , Humans , Male , Middle Aged , Brazil , Psychometrics , Reproducibility of Results , South American People , Surveys and Questionnaires , Eating/psychologyABSTRACT
BACKGROUND: Nosocomial pneumonia ranks among the top 5 diseases that lead to additional financial costs due to hospitalization. This study aimed to evaluate the cost of oral care and its clinical effectiveness in preventing pneumonia in a systematic review. METHODS: The search was conducted in the following databases: PubMed, Cochrane Library, Web of Sciences, Scopus, CINAHL, LILACS, complemented by gray literature and manual search, between January/2021 and August/2022. Two independent reviewers extracted data from the selected articles, individually analyzing each study's quality using the BMJ Drummond checklist. The data were tabulated by clinical or economic type. RESULTS: A total of 3,130 articles were identified; the eligibility criteria were verified, and 12 articles were selected for qualitative analysis. Only 2 achieved satisfactory quality assessment for economic analysis studies. There was heterogeneity between clinical and economic data. Eleven of the 12 studies reported a decrease in the incidence of nosocomial pneumonia following the application of oral care practices. Most authors reported a reduction in the estimate of individual costs, followed by a decrease in the need for antibiotic therapy. The costs of oral care were very low compared to other costs. CONCLUSIONS: Despite the low level of evidence in the literature, heterogeneity and poor quality of the selected studies, most studies concluded that oral care seemed to lead to reduced costs in hospital expenses for treating pneumonia.
Subject(s)
Cross Infection , Healthcare-Associated Pneumonia , Pneumonia , Humans , Cross Infection/prevention & control , Healthcare-Associated Pneumonia/prevention & control , Pneumonia/prevention & control , Anti-Bacterial Agents/therapeutic use , Treatment OutcomeABSTRACT
Neutrophil extracellular traps (NETs) evolved as a unique effector mechanism contributing to resistance against infection that can also promote tissue damage in inflammatory conditions. Malaria infection can trigger NET release, but the mechanisms and consequences of NET formation in this context remain poorly characterized. Here we show that patients suffering from severe malaria had increased amounts of circulating DNA and increased neutrophil elastase (NE) levels in plasma. We used cultured erythrocytes and isolated human neutrophils to show that Plasmodium-infected red blood cells release macrophage migration inhibitory factor (MIF), which in turn caused NET formation by neutrophils in a mechanism dependent on the C-X-C chemokine receptor type 4 (CXCR4). NET production was dependent on histone citrullination by peptidyl arginine deiminase-4 (PAD4) and independent of reactive oxygen species (ROS), myeloperoxidase (MPO) or NE. In vitro, NETs functioned to restrain parasite dissemination in a mechanism dependent on MPO and NE activities. Finally, C57/B6 mice infected with P. berghei ANKA, a well-established model of cerebral malaria, presented high amounts of circulating DNA, while treatment with DNAse increased parasitemia and accelerated mortality, indicating a role for NETs in resistance against Plasmodium infection.
Subject(s)
Erythrocytes/immunology , Extracellular Traps/immunology , Macrophage Migration-Inhibitory Factors/metabolism , Malaria/immunology , Neutrophils/immunology , Plasmodium/immunology , Receptors, CXCR4/metabolism , Animals , Erythrocytes/metabolism , Erythrocytes/parasitology , Extracellular Traps/metabolism , Extracellular Traps/parasitology , Humans , Malaria/metabolism , Malaria/parasitology , Malaria/pathology , Mice , Mice, Inbred C57BL , Neutrophils/metabolism , Neutrophils/parasitology , Parasitemia/immunology , Parasitemia/metabolism , Parasitemia/parasitology , Parasitemia/pathologyABSTRACT
Hemolysis causes an increase of intravascular heme, oxidative damage, and inflammation in which macrophages play a critical role. In these cells, heme can act as a prototypical damage-associated molecular pattern, inducing TLR4-dependent cytokine production through the MyD88 pathway, independently of TRIF. Heme promotes reactive oxygen species (ROS) generation independently of TLR4. ROS and TNF production contribute to heme-induced necroptosis and inflammasome activation; however, the role of ROS in proinflammatory signaling and cytokine production remains unknown. In this study, we demonstrate that heme activates at least three signaling pathways that contribute to a robust MAPK phosphorylation and cytokine expression in mouse macrophages. Although heme did not induce a detectable Myddosome formation, the TLR4/MyD88 axis was important for phosphorylation of p38 and secretion of cytokines. ROS generation and spleen tyrosine kinase (Syk) activation induced by heme were critical for most proinflammatory signaling pathways, as the antioxidant N-acetyl-l-cysteine and a Syk inhibitor differentially blocked heme-induced ROS, MAPK phosphorylation, and cytokine production in macrophages. Early generated mitochondrial ROS induced by heme was Syk dependent, selectively promoted the phosphorylation of ERK1/2 without affecting JNK or p38, and contributed to CXCL1 and TNF production. Finally, lethality caused by sterile hemolysis in mice required TLR4, TNFR1, and mitochondrial ROS, supporting the rationale to target these pathways to mitigate tissue damage of hemolytic disorders.
Subject(s)
Heme/metabolism , Hemolysis/immunology , Reactive Oxygen Species/metabolism , Signal Transduction/immunology , Animals , Chemokine CXCL1/metabolism , Disease Models, Animal , Humans , Macrophages/cytology , Macrophages/immunology , Mice , Mice, Knockout , Mitochondria/immunology , Mitochondria/metabolism , Mitogen-Activated Protein Kinase 1/metabolism , Mitogen-Activated Protein Kinase 3/metabolism , Phosphorylation/immunology , Receptors, Tumor Necrosis Factor, Type I/genetics , Receptors, Tumor Necrosis Factor, Type I/metabolism , Syk Kinase/metabolism , Toll-Like Receptor 4/genetics , Toll-Like Receptor 4/metabolism , Tumor Necrosis Factor-alpha/metabolismABSTRACT
Serological tests detect antibodies generated by infection or vaccination, and are indispensable tools along different phases of a pandemic, from early monitoring of pathogen spread up to seroepidemiological studies supporting immunization policies. This work discusses the development of an accurate and affordable COVID-19 antibody test, from production of a recombinant protein antigen up to test validation and economic analysis. We first developed a cost-effective, scalable technology to produce SARS-COV-2 spike protein and then used this antigen to develop an enzyme-linked immunosorbent assay (ELISA). A receiver operator characteristic (ROC) analysis allowed optimizing the cut-off and confirmed the high accuracy of the test: 98.6% specificity and 95% sensitivity for 11+ days after symptoms onset. We further showed that dried blood spots collected by finger pricking on simple test strips could replace conventional plasma/serum samples. A cost estimate was performed and revealed a final retail price in the range of one US dollar, reflecting the low cost of the ELISA test platform and the elimination of the need for venous blood sampling and refrigerated sample handling in clinical laboratories. The presented workflow can be completed in 4 months from first antigen expression to final test validation. It can be applied to other pathogens and in future pandemics, facilitating reliable and affordable seroepidemiological surveillance also in remote areas and in low-income countries.
ABSTRACT
The dynamics underlying severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reinfection remain poorly understood. We identified a small cluster of patients in Brazil who experienced 2 episodes of coronavirus disease (COVID-19) in March and late May 2020. In the first episode, patients manifested an enhanced innate response compared with healthy persons, but neutralizing humoral immunity was not fully achieved. The second episode was associated with different SARS-CoV-2 strains, higher viral loads, and clinical symptoms. Our finding that persons with mild COVID-19 may have controlled SARS-CoV-2 replication without developing detectable humoral immunity suggests that reinfection is more frequent than supposed, but this hypothesis is not well documented.
Subject(s)
COVID-19 , SARS-CoV-2 , Brazil/epidemiology , Humans , Immunity, Humoral , ReinfectionABSTRACT
N-Quaternized ketene N,O-acetals are typically an unstable, transient class of compounds most commonly observed as reactive intermediates. In this report, we describe a general synthetic approach to a variety of bench-stable N-quaternized ketene N,O-acetals via treatment of pyridine or aniline bases with acetylenic ethers and an appropriate Brønsted or Lewis acid (triflic acid, triflimide, or scandium(III) triflate). The resulting pyridinium and anilinium salts can be used as reagents or synthetic intermediates in multiple reaction types. For example, N-(1-ethoxyvinyl)pyridinium or anilinium salts can thermally release highly reactive O-ethyl ketenium ions for use in acid catalyst-free electrophilic aromatic substitutions. N-(1-Ethoxyvinyl)-2-halopyridinium salts can be employed in peptide couplings as a derivative of Mukaiyama reagents or react with amines in nucleophilic aromatic substitutions under mild conditions. These preliminary reactions illustrate the broad potential of these currently understudied compounds in organic synthesis.
Subject(s)
Acetals , Ketones , Chemistry Techniques, Synthetic , Ethylenes , Indicators and ReagentsABSTRACT
BACKGROUND: Activation of hypnozoites of vivax malaria causes multiple clinical relapses, which contribute to the Plasmodium vivax burden and continuing transmission. Artemisinin-based combination therapy (ACT) is effective against blood-stage P. vivax but requires co-administration with primaquine to achieve radical cure. The therapeutic efficacy of primaquine depends on the generation of a therapeutically active metabolite via cytochrome P450 2D6 (CYP2D6). Impaired CYP2D6 metabolism has been associated with primaquine treatment failure. This study investigated the association between impaired CYP2D6 genotypes, drug-exposure to the long-acting ACT component (schizonticidal drugs) and tolerance and efficacy. METHODS: Adult patients with acute vivax malaria were enrolled in a recently completed trial and treated with artesunate-mefloquine, chloroquine or artemether-lumefantrine. All received concomitant primaquine (0.5 mg/kg/day for 7-9 days). The association between efficacy and safety and drug exposure was explored using area-under-the-curve (AUC) and half-life (t1/2) estimates obtained by non-compartmental analysis of the long half-life drugs. Parasite recurrences by day 63 were categorized as related relapses or re-infections/unrelated hypnozoite activation by genotyping three microsatellite loci and two polymorphic loci of merozoite surface antigen-1. The CYP2D6 genotype was identified with Taqman assays by real-time PCR to 9 polymorphisms (8 SNPs and one deletion). Impaired CYP2D6 activity was inferred using the Activity Score System. RESULTS: Most recurrences in the ASMQ (67%), CQ (80%) and AL (85%) groups were considered related relapses. Eight of nine (88.9%) of the patients with impaired CYP2D6 activity relapsed with related parasite compared to 18/25 (72%) with normal activity (RR = 1.23, 0.88; 1.72, p = 0.40). There were no associations between the measured PK parameters and recurrence. Patients with longer chloroquine half-lives had more pruritus (RR = 1.09, 1.03; 1.14, p = 0.001). Higher CQ AUCs were associated with reduced falls in haemoglobin by day 14 (Coef - 0.02, - 0.005; - 0.03, p = 0.01). All regimens were well tolerated. CONCLUSION: Genotyping of P. vivax showed that activation of related (homologous) hypnozoites was the most frequent cause of recurrence. The high proportion of the impaired CYP2D6 activity among patients with recurrent infections suggests that slow primaquine metabolism might influence related relapse rates in Brazil among patients receiving primaquine for radical cure, although confirmatory studies are needed. There was no association between drug exposure of the long-acting ACT component (schizonticidal drugs) and risk of related relapse. ACT was well tolerated. These results provide further re-assurance about the safety and efficacy of ACT when combined with short course primaquine to treat uncomplicated malaria vivax in Brazil. Trial registration RBR-79s56s ( http://www.ensaiosclinicos.gov.br/rg/RBR-79s56s/ ).
Subject(s)
Antimalarials/pharmacology , Artemisinins/pharmacology , Chloroquine/pharmacology , Primaquine/pharmacology , Adult , Aged , Antimalarials/pharmacokinetics , Artemisinins/pharmacokinetics , Brazil , Chloroquine/pharmacokinetics , Drug Combinations , Female , Humans , Male , Middle Aged , Primaquine/pharmacokinetics , Young AdultABSTRACT
BACKGROUND: In Brazil, 70% of the population depends on the public healthcare system. Since early detection is considered crucial, this study aimed to evaluate temporal changes in breast cancer screening coverage provided under the Brazilian National Health Service (SUS) according to the different regions of the country between 2008 and 2017. METHODS: This ecological study analyzed data on breast cancer screening within the SUS for women aged 50-69 years. Coverage was calculated from the ratio between the number of screening tests conducted and the expected number for the target population. Joinpoint regression analysis was used to calculate annual percent changes (APC) in coverage. RESULTS: Around 19 million mammograms were performed in 50-69-year old women within the SUS between 2008 and 2016. The estimated APC indicates that breast cancer screening coverage increased by 14.5% annually in Brazil between 2008 and 2012 (p < 0.01), with figures stabilizing between 2012 and 2017 as shown by an APC of - 0.4% (p = 0.3). In the five geographic regions of the country, the APC initially increased, then stabilized in the north, northeast and southeast and decreased in the south and Midwest. Of the 26 states, coverage increased in seven and remained stable in six. In the other 13, there was an initial increase followed by stabilization in 11, and a reduction in coverage in two. In the Federal District, coverage remained stable throughout the study period. CONCLUSION: Evaluation of the temporal changes in breast cancer screening coverage provided under the Brazilian National Health Service revealed an initial increase, confirming that public policies were effective, although insufficient to ensure organized screening. There appears to be a lack of uniformity between the different regions and states and this situation is highlighted in the final 5-year period, with the APC reflecting stabilization of breast cancer screening coverage.
Subject(s)
Breast Neoplasms/diagnosis , Early Detection of Cancer/trends , Mammography/trends , Mass Screening/trends , National Health Programs/statistics & numerical data , Aged , Brazil/epidemiology , Female , Humans , Middle Aged , Time FactorsABSTRACT
PURPOSE: Mean Glandular Dose (MGD) is the quantity related to the risk of radiation-induced breast cancer. This study aimed to evaluate the MGD in screening mammography for women with breast implants. METHODS: This retrospective study used data of 2680 mammographies of 335 asymptomatic women with mammary implants examined in a digital direct x-ray unit. Each woman had a total of eight images: four in standard views and four with posterior displacement of the implant (ID). Data on kV, mAs, target/filter combination, compressed breast thickness and MGD were obtained from the DICOM header of the stored images. Quantitative variables were presented through descriptive statistics for median (5th-95th percentiles); and the qualitative variables were presented by numbers and percentages. Mean glandular doses of standard views and ID views were compared and statistical analysis was used to assess the influence of implant position, breast glandularity and thickness on mean glandular doses. RESULTS: Median MGD for standard views were 3.30 (2.60-4.00) mGy for CC and 3.31 (2.70-4.20) mGy for MLO. For ID views, median were 1.20 (0.90-2.20) mGy and 1.40 (0.97-3.74) mGy for CC and MLO views, respectively. Median MGD for the whole examination of women with breast implants was 9.60 (7.92-12.07) mGy, ranging from 6.25 to 21.50 mGy. When comparing MGD median for standard and ID views it was found a statistically significant difference (p < 0.05), with higher doses for the standard views due to the greater compressed breast thickness in these views. It was observed that, in the standard views, MGD decreases with increasing breast thickness due to the manual radiographic techniques used to expose the women. It was also observed that implant position does not affect MGD in breast augmentation mammography. CONCLUSION: Mammography of women with mammary implants gives higher radiation doses when compared with those without implants. For more accurate dose assessment in augmented breast mammography, it is necessary that specific conversion factors for the calculation of MGD based on air kerma at entrance of breasts with implants are made available.
Subject(s)
Breast Implants , Mammary Glands, Human/radiation effects , Mammography , Radiation Dosage , Adult , Female , Humans , Middle Aged , Retrospective StudiesABSTRACT
The aim of the present study was to evaluate the effects of LLLT prior to muscle injury with and without post-injury irradiation on the expression of isoforms of myosin heavy chain (MyHC), calcineurin (CaN), and myostatin during the repair process. Wistar rats were divided into five groups: control (n = 7); injury (n = 21); LLLT + injury (n = 21); injury + LLLT (n = 21), and LLLT + injury + LLLT (n = 21). Cryoinjury was performed on the tibialis anterior (TA) muscle. The injured groups were euthanized at 3, 7, and 14 days after injury. LLLT was performed using an infrared laser (780 nm) with the following parameters: 10 J/cm2, 40 mW, 10 s per point, 8 points, and 3.2 J of total energy. At the end of each period, the TA muscle was removed for the analysis of MyHC, CaN, and myostatin gene expression using real-time PCR. The data were tested statistically by Kruskal-Wallis with Dunn's post hoc test (p < 0.05). The results demonstrated that prior irradiation reduced the mRNA expression of all proteins at 3 days. Post irradiation reduced the mRNA expression of MyHC-1, MyHC-2a, MyHC-2b, and CaN at 7 days. Prior irradiation combined with post-injury irradiation reduced the mRNA expression of MyHC-2x and CaN at 14 days and increased the mRNA expression of myostatin in the same period. In conclusion, different protocols of photobiomodulation can modulate the expression of the different isoforms of MyHC, CaN, and myostatin during the repair process. It is noteworthy that the combination of the prior and post-injury irradiation was the protocol that most promoted changes in the final phase of the repair process.
Subject(s)
Low-Level Light Therapy/methods , Muscle Proteins/metabolism , Muscle, Skeletal/injuries , Muscle, Skeletal/metabolism , Regeneration/radiation effects , Wound Healing/radiation effects , Animals , Gene Expression Regulation/radiation effects , Male , Muscle Proteins/genetics , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats, Wistar , Regeneration/genetics , Wound Healing/geneticsABSTRACT
AIMS: The aim of the study is to verify the knowledge and practices of health professionals working in prenatal care (PNC) related with syphilis during pregnancy and to identify the main barriers to the implementation of protocols for the control of this disease. METHODS: A cross-sectional study in Teresina, Brazil, from January to May 2015, was conducted with 366 physicians and nurses working in PNC, corresponding to 70% of eligible professionals. We evaluated 20 knowledge and practice criteria related to the diagnosis and treatment of syphilis during pregnancy with a 95% compliance standard. We performed descriptive analysis of the data and used χ2 statistical test to verify differences according to professional category. RESULTS: Only 2 criteria, "knowledge about mother to child transmission according to gestational age" and "counselling on infection," reached 95% compliance. Knowledge of the epidemiological profile of congenital syphilis and the goal of elimination of congenital syphilis and knowledge about serological tests had scores below 50%, while practices related with posttest counselling, cure control, and treatment of partners reached 60%. We identified organisational barriers related to the late initiation of PNC, to the delayed return of syphilis test results, to the application of benzathine penicillin in primary care units and to the treatment of partners. CONCLUSIONS: Strategies for early initiation of PNC, implementation of rapid tests for syphilis, ensuring treatment of pregnant women with penicillin, adequate partner treatment, and continued education of health professionals on clinical management and counselling in sexually transmitted diseases are necessary to eliminate congenital syphilis.
Subject(s)
Guideline Adherence , Health Knowledge, Attitudes, Practice , Health Personnel , Pregnancy Complications, Infectious/drug therapy , Prenatal Care , Syphilis/drug therapy , Adult , Aged , Brazil , Cross-Sectional Studies , Female , Health Care Surveys , Humans , Infectious Disease Transmission, Vertical/prevention & control , Male , Middle Aged , Pregnancy , Syphilis/diagnosis , Young AdultABSTRACT
OBJECTIVE: The objective of this study was to check which initial dose of vancomycin is needed to achieve the therapeutic target that is currently used in pediatrics. METHODS: The search was conducted in the following data sources: Pubmed (1980-2017), the Cochrane Library, and Embase (1986-2017) and the references of the published studies; searches were performed using the key terms: child, children, pediatrics, infants and adolescents, vancomycin, pharmacokinetics, and pharmacodynamics. The data extracted from the studies were analyzed and grouped using RevMan V 5.2 software. The confidence interval (CI) 95% and the odds ratio (OR) were calculated considering the Mantel-Haenszel random effect. RESULTS: From the 704 studies identified, 40 revealed eligibility for this review and only 20 presented enough data to be included in the statistical analysis. The articles found in this review were published between 1980 and 2017. The vancomycin doses varied between 40 mg/kg/day to 120 mg/kg/day. The statistical tests demonstrated significant clinical heterogeneity of I2 (84%). CONCLUSIONS: The meta-analysis study revealed in the majority of studies that doses lower than 60 mg/kg/day were not enough to achieve desirable vancomycin plasma concentrations "area under the curve in 24 h/minimum inhibitory concentration >400 (AUC0-24/MIC>400) or trough 10-20 mg/L" to control bacterial infections in pediatrics.
Subject(s)
Anti-Bacterial Agents/administration & dosage , Vancomycin/administration & dosage , Anti-Bacterial Agents/blood , Anti-Bacterial Agents/pharmacokinetics , Anti-Bacterial Agents/therapeutic use , Child , Humans , Pediatrics , Vancomycin/blood , Vancomycin/pharmacokinetics , Vancomycin/therapeutic useABSTRACT
The increase of extracellular heme is a hallmark of hemolysis or extensive cell damage. Heme has prooxidant, cytotoxic, and inflammatory effects, playing a central role in the pathogenesis of malaria, sepsis, and sickle cell disease. However, the mechanisms by which heme is sensed by innate immune cells contributing to these diseases are not fully characterized. We found that heme, but not porphyrins without iron, activated LPS-primed macrophages promoting the processing of IL-1ß dependent on nucleotide-binding domain and leucine rich repeat containing family, pyrin domain containing 3 (NLRP3). The activation of NLRP3 by heme required spleen tyrosine kinase, NADPH oxidase-2, mitochondrial reactive oxygen species, and K(+) efflux, whereas it was independent of heme internalization, lysosomal damage, ATP release, the purinergic receptor P2X7, and cell death. Importantly, our results indicated the participation of macrophages, NLRP3 inflammasome components, and IL-1R in the lethality caused by sterile hemolysis. Thus, understanding the molecular pathways affected by heme in innate immune cells might prove useful to identify new therapeutic targets for diseases that have heme release.
Subject(s)
Heme/metabolism , Hemolysis/physiology , Inflammasomes/metabolism , Animals , Carrier Proteins/genetics , Carrier Proteins/metabolism , Caspase 1/deficiency , Caspase 1/genetics , Caspase 1/metabolism , Heme/chemistry , Heme/immunology , Hemolysis/immunology , Humans , Inflammasomes/immunology , Interleukin-1beta/metabolism , Macrophage Activation , Macrophages/immunology , Macrophages/metabolism , Male , Membrane Glycoproteins/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout , Models, Biological , NADPH Oxidase 2 , NADPH Oxidases/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein , Potassium/metabolism , Protoporphyrins/chemistry , Protoporphyrins/metabolism , Reactive Oxygen Species/metabolismABSTRACT
Diseases that cause hemolysis or myonecrosis lead to the leakage of large amounts of heme proteins. Free heme has proinflammatory and cytotoxic effects. Heme induces TLR4-dependent production of tumor necrosis factor (TNF), whereas heme cytotoxicity has been attributed to its ability to intercalate into cell membranes and cause oxidative stress. We show that heme caused early macrophage death characterized by the loss of plasma membrane integrity and morphologic features resembling necrosis. Heme-induced cell death required TNFR1 and TLR4/MyD88-dependent TNF production. Addition of TNF to Tlr4(-/-) or to Myd88(-/-) macrophages restored heme-induced cell death. The use of necrostatin-1, a selective inhibitor of receptor-interacting protein 1 (RIP1, also known as RIPK1), or cells deficient in Rip1 or Rip3 revealed a critical role for RIP proteins in heme-induced cell death. Serum, antioxidants, iron chelation, or inhibition of c-Jun N-terminal kinase (JNK) ameliorated heme-induced oxidative burst and blocked macrophage cell death. Macrophages from heme oxygenase-1 deficient mice (Hmox1(-/-)) had increased oxidative stress and were more sensitive to heme. Taken together, these results revealed that heme induces macrophage necrosis through 2 synergistic mechanisms: TLR4/Myd88-dependent expression of TNF and TLR4-independent generation of ROS.
Subject(s)
Heme/pharmacology , Macrophages/drug effects , Reactive Oxygen Species/metabolism , Tumor Necrosis Factors/metabolism , Animals , Blotting, Western , Cell Survival/drug effects , Cells, Cultured , Dose-Response Relationship, Drug , Heme Oxygenase-1/genetics , Heme Oxygenase-1/metabolism , Imidazoles/pharmacology , Indoles/pharmacology , JNK Mitogen-Activated Protein Kinases/metabolism , Macrophages/cytology , Macrophages/metabolism , Membrane Proteins/genetics , Membrane Proteins/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout , Myeloid Differentiation Factor 88/genetics , Myeloid Differentiation Factor 88/metabolism , NIH 3T3 Cells , Necrosis , Receptor-Interacting Protein Serine-Threonine Kinases/antagonists & inhibitors , Receptor-Interacting Protein Serine-Threonine Kinases/genetics , Receptor-Interacting Protein Serine-Threonine Kinases/metabolism , Receptors, Tumor Necrosis Factor, Type I/genetics , Receptors, Tumor Necrosis Factor, Type I/metabolism , Toll-Like Receptor 4/genetics , Toll-Like Receptor 4/metabolism , Tumor Necrosis Factors/pharmacologyABSTRACT
The hydrothermal pretreatment process stands out as a pivotal step in breaking down the hemicellulosic fraction of lignocellulosic biomasses, such as sugarcane bagasse and eucalyptus sawdust. This pretreatment step is crucial for preparing these materials for subsequent processes, particularly in food applications. This technique aims to disintegrate plant wall components like cellulose, hemicellulose, and lignin, and facilitating access in later phases such as enzymatic hydrolysis, and ultimately making fermentable sugars available. In this study, sugarcane bagasse and eucalyptus sawdust biomass underwent hydrothermal pretreatment at specific conditions, yielding two key components: dry biomass and hemicellulose liquor. The primary focus was to assess the impact of hydrothermal pretreatment followed by enzymatic hydrolysis, using the Celic Ctec III enzyme cocktail, to obtain fermentable sugars. These sugars were then transformed into membranes via strain Gluconacetobacter xylinus bacterial biosynthesis. Notably, the addition of a nitrogen source significantly boosted production to 14.76 g/ in hydrolyzed sugarcane bagasse, underscoring its vital role in bacterial metabolism. Conversely, in hydrolyzed eucalyptus, nitrogen source inclusion unexpectedly decreased yield, highlighting the intricate interactions in fermentation media and the pivotal influence of nitrogen supplementation. Characterization of membranes obtained in synthetic and hydrolyzed media through techniques such as FEG-SEM, FTIR, and TGA, followed by mass balance assessment, gauged their viability on an industrial scale. This comprehensive study aimed not only to understand the effects of pretreatment and enzymatic hydrolysis but to also evaluate the applicability and sustainability of the process on a large scale, providing crucial insights into its feasibility and efficiency in practical food-related scenarios, utilizing nanocellulose bacterial (BNC) as a key component.
Subject(s)
Biomass , Cellulose , Eucalyptus , Lignin , Saccharum , Lignin/chemistry , Lignin/metabolism , Cellulose/chemistry , Cellulose/metabolism , Hydrolysis , Eucalyptus/chemistry , Saccharum/chemistry , Fermentation , Gluconacetobacter xylinus/metabolism , Polysaccharides/chemistry , Polysaccharides/metabolismABSTRACT
Background: PURA syndrome is a rare genetic disorder characterized by neonatal hypotonia, neurodevelopmental delay, facial dysmorphism, epileptic seizures, complex movement disorders, among other features. Although many pathogenic variants have been reported, there is currently no clear genotype-phenotype association identified. Cases: Four patients diagnosed with PURA syndrome, despite carrying different pathogenic variants, presented a similar mixed hyperkinetic movement disorder. The phenomenology presented a complex set of symptoms, including chorea, interspersed with dystonic and uncoordinated movements. All patients presented also hypotonia, nystagmus, feeding difficulties, craniofacial dysmorphisms. Hypersomnolence and breathing problems were common and observed in three patients, while seizures were found in three patients. Conclusions: PURA syndrome may be considered in the differential diagnosis of infants with severe hypotonia, feeding difficulties and severe developmental delay with epileptic seizures, that start to develop a mixed hyperkinetic movement disorder. These complex movements may be an important clue for the diagnosis of this rare disorder.
ABSTRACT
Objectives: This study aimed to evaluate COVID-19 effects on breast cancer screening and clinical stage at diagnosis in patients of 50-69 years of age receiving care within the public healthcare network (SUS) in 2013-2021 in Brazil and its macro-regions. Methods: This ecological study used Poisson regression to analyze trends in screening and staging. A secondary database was formed using SUS sources: outpatient data system of the SUS network and Oncology-Brazil Panel. Results: There was a reduction in screening, with an annual percent change of -5.9 (p < 0.022). The number of notified cases fell by 31.5% in 2020-2021 compared to 2018-2019. There was a 10.7% increase in the proportion of stage III/IV cases (p < 0.001) in 2020-2021 compared to 2013-2019, now surpassing the number of cases of early stage breast cancer. Conclusion: COVID-19 led to a reduction in breast cancer screening and an expressive increase in advanced tumors in users of the public healthcare network. Urgent interventions in public policies are required as the negative effects of the pandemic on the diagnosis/treatment of breast cancer are becoming apparent even earlier than expected.
Subject(s)
Breast Neoplasms , COVID-19 , Humans , Female , Breast Neoplasms/epidemiology , Breast Neoplasms/diagnosis , Brazil/epidemiology , COVID-19/epidemiology , Mammography , Early Detection of CancerABSTRACT
The severe acute respiratory syndrome coronavirus 2, the agent of the ongoing coronavirus disease 2019 (COVID-19) pandemic, has spread worldwide since it was first identified in November 2019 in Wuhan, China. Since then, progress in pathogenesis linked severity of this systemic disease to the hyperactivation of network of cytokine-driven pro-inflammatory cascades. Here, we aimed to identify molecular biomarkers of disease severity by measuring the serum levels of inflammatory mediators in a Brazilian cohort of patients with COVID-19 and healthy controls (HCs). Critically ill patients in the intensive care unit were defined as such by dependence on oxygen supplementation (93% intubated and 7% face mask), and computed tomography profiles showing ground-glass opacity pneumonia associated to and high levels of D-dimer. Our panel of mediators included HMGB1, ATP, tissue factor, PGE2 , LTB4 , and cys-LTs. Follow-up studies showed increased serum levels of every inflammatory mediator in patients with COVID-19 as compared to HCs. Originally acting as a transcription factor, HMGB1 acquires pro-inflammatory functions following secretion by activated leukocytes or necrotic tissues. Serum levels of HMGB1 were positively correlated with cys-LTs, D-dimer, aspartate aminotransferase, and alanine aminotransferase. Notably, the levels of the classical alarmin HMGB1 were higher in deceased patients, allowing their discrimination from patients that had been discharged at the early pulmonary and hyperinflammatory phase of COVID-19. In particular, we verified that HMGB1 levels above 125.4 ng/ml is the cutoff that distinguishes patients that are at higher risk of death. In conclusion, we propose the use of serum levels of HMGB1 as a biomarker of severe prognosis of COVID-19.