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1.
Appl Environ Microbiol ; 90(6): e0032824, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38712952

RESUMO

Cells of Vibrio fischeri colonize the light organ of Euprymna scolopes, providing the squid bioluminescence in exchange for nutrients and protection. The bacteria encounter DNA-rich mucus throughout their transition to a symbiotic lifestyle, leading us to hypothesize a role for nuclease activity in the colonization process. In support of this, we detected abundant extracellular nuclease activity in growing cells of V. fischeri. To discover the gene(s) responsible for this activity, we screened a V. fischeri transposon mutant library for nuclease-deficient strains. Interestingly, only one strain, whose transposon insertion mapped to nuclease gene VF_1451, showed a complete loss of nuclease activity in our screens. A database search revealed that VF_1451 is homologous to the nuclease-encoding gene xds in Vibrio cholerae. However, V. fischeri strains lacking xds eventually revealed slight nuclease activity on plates upon prolonged incubation. This led us to hypothesize that a second secreted nuclease, identified through a database search as VF_0437, a homolog of V. cholerae dns, might be responsible for the residual nuclease activity. Here, we show that Xds and/or Dns are involved in essential aspects of V. fischeri biology, including natural transformation, aggregation, and phosphate scavenging. Furthermore, strains lacking either nuclease were outcompeted by the wild type for squid colonization. Understanding the specific role of nuclease activity in the squid colonization process represents an intriguing area of future research.IMPORTANCEFrom soil and water to host-associated secretions such as mucus, environments that bacteria inhabit are awash in DNA. Extracellular DNA (eDNA) is a nutritious resource that microbes dedicate significant energy to exploit. Calcium binds eDNA to promote cell-cell aggregation and horizontal gene transfer. eDNA hydrolysis impacts the construction of and dispersal from biofilms. Strategies in which pathogens use nucleases to avoid phagocytosis or disseminate by degrading host secretions are well-documented; significantly less is known about nucleases in mutualistic associations. This study describes the role of nucleases in the mutualism between Vibrio fischeri and its squid host Euprymna scolopes. We find that nuclease activity is an important determinant of colonization in V. fischeri, broadening our understanding of how microbes establish and maintain beneficial associations.


Assuntos
Aliivibrio fischeri , Proteínas de Bactérias , Decapodiformes , Fosfatos , Simbiose , Aliivibrio fischeri/genética , Aliivibrio fischeri/fisiologia , Aliivibrio fischeri/enzimologia , Decapodiformes/microbiologia , Animais , Fosfatos/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Desoxirribonucleases/metabolismo , Desoxirribonucleases/genética
2.
BMC Infect Dis ; 24(1): 109, 2024 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-38245682

RESUMO

BACKGROUND: Actinomyces turicensis is rarely responsible of clinically relevant infections in human. Infection is often misdiagnosed as malignancy, tuberculosis, or nocardiosis, therefore delaying the correct identification and treatment. Here we report a case of a 55-year-old immunocompetent adult with brain abscess caused by A. turicensis. A systematic review of A. turicensis infections was performed. METHODS: A systematic review of the literature was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The databases MEDLINE, Embase, Web of Science, CINAHL, Clinicaltrials.gov and Canadian Agency for Drugs and Technology in Health (CADTH) were searched for all relevant literature. RESULTS: Search identified 47 eligible records, for a total of 67 patients. A. turicensis infection was most frequently reported in the anogenital area (n = 21), causing acute bacterial skin and skin structure infections (ABSSSI) including Fournier's gangrene (n = 12), pulmonary infections (n = 8), gynecological infections (n = 6), cervicofacial district infections (n = 5), intrabdominal or breast infections (n = 8), urinary tract infections (n = 3), vertebral column infections (n = 2) central nervous system infections (n = 2), endocarditis (n = 1). Infections were mostly presenting as abscesses (n = 36), with or without concomitant bacteremia (n = 7). Fever and local signs of inflammation were present in over 60% of the cases. Treatment usually involved surgical drainage followed by antibiotic therapy (n = 51). Antimicrobial treatments most frequently included amoxicillin (+clavulanate), ampicillin/sulbactam, metronidazole or cephalosporins. Eighty-nine percent of the patients underwent a full recovery. Two fatal cases were reported. CONCLUSIONS: To the best of our knowledge, we hereby present the first case of a brain abscess caused by A. turicensis and P. mirabilis. Brain involvement by A. turicensis is rare and may result from hematogenous spread or by dissemination of a contiguous infection. The infection might be difficult to diagnose and therefore treatment may be delayed. Nevertheless, the pathogen is often readily treatable. Diagnosis of actinomycosis is challenging and requires prompt microbiological identification. Surgical excision and drainage and antibiotic treatment usually allow for full recovery.


Assuntos
Actinomicose , Abscesso Encefálico , Adulto , Humanos , Pessoa de Meia-Idade , Actinomyces , Actinomicose/diagnóstico , Actinomicose/tratamento farmacológico , Antibacterianos/uso terapêutico , Abscesso Encefálico/diagnóstico , Abscesso Encefálico/tratamento farmacológico , Canadá
3.
Microvasc Res ; 148: 104553, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37230166

RESUMO

BACKGROUND: Metabolically healthy obesity (MHO), a phenotype of obesity considered to be of lower cardiovascular risk, is still a controversial concept. This study aimed to investigate the presence of subclinical systemic microvascular dysfunction in individuals with MHO. METHODS: This was a cross-sectional study in which 112 volunteers were allocated into three groups: metabolically healthy normal weight (MHNW), MHO, or metabolically unhealthy obesity (MUO). Obesity was defined as a body mass index (BMI) ≥ 30 kg/m2. MHO was defined as the absence of any component of metabolic syndrome, except waist circumference. Microvascular reactivity was evaluated using cutaneous laser speckle contrast imaging. RESULTS: Mean age was 33.2 ± 7.66 years. The median BMI in the MHNW, MHO and MUO groups was 23.6, 32.8, and 35.8 kg/m2, respectively. Baseline microvascular conductance values were lower in the MUO group (0.25 ± 0.08 APU/mmHg) than in MHO (0.30 ± 0.10 APU/mmHg) and MHNW groups (0.33 ± 0.12 APU/mmHg) (P = 0.0008). There were no significant differences regarding endothelial-dependent (acetylcholine stimulation or postocclusive reactive hyperemia) or endothelial-independent (sodium nitroprusside stimulation) microvascular reactivity among the groups. CONCLUSIONS: Individuals with MUO had lower baseline systemic microvascular flow than those with MHNW or MHO, but endothelium-dependent or endothelium-independent microvascular reactivity were not changed in any of the groups. The relatively young age of the study population, the low frequency of class III obesity, or the strict definition of MHO (absence of any metabolic syndrome criteria) might account for the lack of difference of microvascular reactivity among MHNW, MHO or MUO.


Assuntos
Síndrome Metabólica , Obesidade Metabolicamente Benigna , Humanos , Síndrome Metabólica/diagnóstico , Síndrome Metabólica/epidemiologia , Obesidade Metabolicamente Benigna/diagnóstico , Obesidade Metabolicamente Benigna/epidemiologia , Estudos Transversais , Obesidade , Índice de Massa Corporal , Fenótipo , Fatores de Risco
4.
Chemotherapy ; 2023 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-37963447

RESUMO

Introduction Acute eosinophilic pneumonia (AEP) is a rare respiratory condition caused by eosinophil accumulation in the pulmonary tissue that can be related to drug administration. Daptomycin, an antibiotic active against gram-positive bacteria, is one of the leading causes of AEP among drugs. In order to raise awareness of this rare syndrome, in our work we have described a case of an 82 years-old male with Enterococcus faecalis endocarditis treated with daptomycin, who developed a daptomycin-induced AEP. We have performed a systematic review of the literature for all similar reported cases. Methods The systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. To conduct the analysis, the terms "daptomycin AND eosinoph* AND pneum*", were entered the databases Medline, Cinahl and Embase on April 13th, 2023. We considered relevant all records documenting AEP after daptomycin use. No restrictions in terms of year or language were made. A formal appraisal of observational studies was performed by Newcastle-Ottawa Scale. All results and data were reported by means of tables. Results Our search identified 93 relevant records, published between 2007 and 2023. A total of 120 patients were considered. Patients who experienced AEP were mostly males (n=88, 73.3%) with a mean age of 68.28 years (SD11.54). Daptomycin was most frequently prescribed for osteoarticular infections (n=75, 62.5%) and to treat gram-positive cocci infections. The most frequently isolated pathogen was Methicillin-resistant Staphylococcus aureus (MRSA). Daptomycin was mostly used with off-label indications (n=89, 74%). Symptoms of AEP were usually reported after a mean of 21.75 days of treatment (range 3-84) and typically included fever, dyspnea, dry cough and acute respiratory failure. Reported treatment strategies invariably included daptomycin withdrawal, respiratory support, and corticosteroid treatment. One hundred and sixteen patients fully recovered. A fatal outcome was described in 4 patients. Suggestive symptoms and imaging raised suspicion for AEP, confirmed with bronchoalveolar lavage in 57.5% of the cases. Discussion and Conclusions Daptomycin-induced AEP is a rare but potentially fatal complication, mostly reported after long treatment with daptomycin. Clinicians should be aware of this syndrome, as it could be initially misdiagnosed for an acute infectious respiratory syndrome, resulting in a delay in its diagnosis and treatment. Furthermore, since the risk of developing AEP is increased by longer drug exposure, caution should be used when discussing the use of daptomycin in longer treatment regimens.

5.
Int J Mol Sci ; 24(2)2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36674930

RESUMO

Acute kidney injury (AKI) is a common and devastating pathologic condition, associated with considerable high morbidity and mortality. Although significant breakthroughs have been made in recent years, to this day no effective pharmacological therapies for its treatment exist. AKI is known to be connected with intrarenal and systemic inflammation. The innate immune system plays an important role as the first defense response mechanism to tissue injury. Toll-like receptor 4 (TLR4) is a well-characterized pattern recognition receptor, and increasing evidence has shown that TLR4 mediated inflammatory response, plays a pivotal role in the pathogenesis of acute kidney injury. Pathogen-associated molecular patterns (PAMPS), which are the conserved microbial motifs, are sensed by these receptors. Endogenous molecules generated during tissue injury, and labeled as damage-associated molecular pattern molecules (DAMPs), also activate pattern recognition receptors, thereby offering an understanding of sterile types of inflammation. Excessive, uncontrolled and/or sustained activation of TLR4, may lead to a chronic inflammatory state. In this review we describe the role of TLR4, its endogenous ligands and activation in the inflammatory response to ischemic/reperfusion-induced AKI and sepsis-associated AKI. The potential regeneration signaling patterns of TLR4 in acute kidney injury, are also discussed.


Assuntos
Injúria Renal Aguda , Receptor 4 Toll-Like , Humanos , Injúria Renal Aguda/patologia , Inflamação/patologia , Receptores de Reconhecimento de Padrão/fisiologia , Transdução de Sinais , Rim/patologia
6.
Medicina (Kaunas) ; 59(10)2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37893475

RESUMO

Background and Objectives: Gastric neuroendocrine neoplasms (gNENs) represent rare but increasingly recognized tumors. They are distinguished into three main clinical types (type-1, type-2, and type-3) according to gastrin level and at histological evaluation in well-differentiated G1, G2, or G3 lesions, as well as poorly-differentiated lesions. Small type-1 and type-2 neoplasms with low proliferation indices demonstrated excellent survival without progression during an extended follow-up period, and for these reasons, active endoscopic observation or endoscopic resection are feasible options. On the other hand, surgery is the treatment of choice for more aggressive type-3, G3, or infiltrating neoplasms. The present study aims to comprehensively review and compare the available therapeutic strategies for gNENs. Materials and Methods: A computerized literature search was performed using relevant keywords to identify all of the pertinent articles with particular attention to gNEN endoscopic treatment. Results: In recent years, different endoscopic resective techniques (such as endoscopic mucosal dissection, modified endoscopic mucosal resection, and endoscopic full-thickness resection) have been developed, showing a high rate of complete resection for advanced and more aggressive lesions. Conclusions: Overall, gNENs represent a heterogeneous group of lesions with varying behavior which require personalized management. The non-operative approach for small type-1 gNENs seems to be feasible and should be promoted. A step-up approach with minimally invasive endoscopic therapies might be proposed, particularly for type-1 gNEN. On the other hand, it is important to recognize the negative prognostic factors in order to identify those rare cases requiring more aggressive approaches. A possible therapeutic algorithm for localized gNEN management is provided.


Assuntos
Ressecção Endoscópica de Mucosa , Tumores Neuroendócrinos , Neoplasias Gástricas , Humanos , Estudos Retrospectivos , Neoplasias Gástricas/cirurgia , Neoplasias Gástricas/patologia , Tumores Neuroendócrinos/cirurgia , Endoscopia , Resultado do Tratamento
7.
Appl Environ Microbiol ; 88(22): e0163522, 2022 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-36342139

RESUMO

Cells of Vibrio fischeri colonize the light organ of Euprymna scolopes, providing the squid bioluminescence in exchange for nutrients and protection. The bacteria encounter DNA-rich mucus throughout their transition to a symbiotic lifestyle, leading us to hypothesize a role for nuclease activity in the colonization process. In support of this, we detected abundant extracellular nuclease activity in growing cells of V. fischeri. To discover the gene(s) responsible for this activity, we screened a V. fischeri transposon mutant library for nuclease-deficient strains. Interestingly, only one strain, whose transposon insertion mapped to nuclease gene VF_1451, showed complete loss of nuclease activity in our screens. A database search revealed that VF_1451 is homologous to the nuclease-encoding gene xds in Vibrio cholerae. However, V. fischeri strains lacking xds eventually revealed slight nuclease activity on plates after 72 h. This led us to hypothesize that a second secreted nuclease, identified through a database search as VF_0437, a homolog of V. cholerae dns, might be responsible for the residual nuclease activity. Here, we show that Xds and/or Dns are involved in essential aspects of V. fischeri biology, including natural transformation, aggregation, and phosphate scavenging. Furthermore, strains lacking either nuclease were outcompeted by the wild type for squid colonization. Understanding the specific role of nuclease activity in the squid colonization process represents an intriguing area of future research. IMPORTANCE From soil and water to host-associated secretions such as mucus, environments that bacteria inhabit are awash in DNA. Extracellular DNA (eDNA) is a nutritious resource that microbes dedicate significant energy to exploit. Calcium binds eDNA to promote cell-cell aggregation and horizontal gene transfer. eDNA hydrolysis impacts construction of and dispersal from biofilms. Strategies in which pathogens use nucleases to avoid phagocytosis or disseminate by degrading host secretions are well documented; significantly less is known about nucleases in mutualistic associations. This study describes the role of nucleases in the mutualism between V. fischeri and its squid host, Euprymna scolopes. We find that nuclease activity is an important determinant of colonization in V. fischeri, broadening our understanding of how microbes establish and maintain beneficial associations.


Assuntos
Aliivibrio fischeri , Decapodiformes , Animais , Aliivibrio fischeri/genética , Decapodiformes/microbiologia , Simbiose , Fosfatos , Biofilmes
8.
BMC Cardiovasc Disord ; 22(1): 394, 2022 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-36057570

RESUMO

BACKGROUND: As patient exposure to ionizing radiation raises concern about malignancy risks, this study evaluated the effect of ionizing radiation on patients undergoing myocardial perfusion imaging (MPI) using the comet assay, a method for detection of DNA damage. METHODS: Patients without cancer, acute or autoimmune diseases, recent surgery or trauma, were studied. Gated single-photon myocardial perfusion imaging was performed with Tc-99m sestamibi. Peripheral blood was collected before radiotracer injection at rest and 60-90 min after injection. Single-cell gel electrophoresis (comet assay) was performed with blood lymphocytes to detect strand breaks, which determine a "comet tail" of variable size, visually scored by 3 observers in a fluorescence microscope after staining (0: no damage, no tail; 1: small damage; 2: large damage; 3: full damage). A damage index was calculated as a weighted average of the cell scores. RESULTS: Among the 29 individuals included in the analysis, age was 65.3 ± 9.9 years and 18 (62.1%) were male. The injected radiotracer dose was 880.6 ± 229.4 MBq. Most cells (approximately 70%) remained without DNA fragmentation (class 0) after tracer injection. There were nonsignificant increases of classes 1 and 2 of damage. Class 3 was the least frequent both before and after radiotracer injection, but displayed a significant, 44% increase after injection. CONCLUSION: While lymphocytes mostly remained in class 0, an increase in class 3 DNA damage was detected. This may suggest that, despite a probable lack of biologically relevant DNA damage, there is still a need for tracer dose reductions in MPI.


Assuntos
Imagem de Perfusão do Miocárdio , Tecnécio Tc 99m Sestamibi , Idoso , Dano ao DNA , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Imagem de Perfusão do Miocárdio/métodos , Perfusão , Projetos Piloto , Radiação Ionizante
9.
Microcirculation ; 28(2): e12664, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33064364

RESUMO

OBJECTIVE: This study compares microvascular reactivity (MR) in chronic Chagas disease (CD) patients with healthy individuals, matched for sex and age. In addition, we evaluated the association between MR and left ventricular ejection fraction (LVEF) in patients. METHODS: Acetylcholine iontophoresis was performed on the forearm skin, using laser speckle contrast imaging, to evaluate endothelium-dependent vasodilation. Clinical data were obtained from medical records. RESULTS: Thirty-six patients were compared to 25 healthy individuals (controls). Vasodilation was higher in controls, when compared to patients (p < .0001). There was a significant association between LVEF, stratified into quartiles, and MR (p-value for linear trend = .002). In addition, there was no difference in MR between patients with normal LVEF and the control group. In patients, MR was independent of the presence of arterial hypertension or diabetes. CONCLUSIONS: We have shown for the first time that the reduction of MR is associated with a decrease of LVEF in a cohort of chronic CD patients. The results were not affected by comorbidities, such as hypertension or diabetes. The evaluation of systemic endothelial function may be useful to tailor therapeutic and preventive approaches, targeted at systolic left ventricular failure associated with chronic CD cardiomyopathy.


Assuntos
Doença de Chagas , Hipertensão , Disfunção Ventricular Esquerda , Endotélio Vascular , Humanos , Volume Sistólico , Vasodilatadores , Função Ventricular Esquerda
10.
Microvasc Res ; 134: 104119, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33278457

RESUMO

BACKGROUND: Microvascular dysfunction, serum cytokines and chemokines may play important roles in pathophysiology of coronavirus disease 2019 (COVID-19), especially in severe cases. METHODS: Patients with COVID-19 underwent non-invasive evaluation of systemic endothelium-dependent microvascular reactivity - using laser Doppler perfusion monitoring in the skin of the forearm - coupled to local thermal hyperemia. Maximal microvascular vasodilatation (44 °C thermal plateau phase) was used as endpoint. A multiplex biometric immunoassay was used to assess a panel of 48 serum cytokines and chemokines. Severe COVID-19 (S-COVID) was defined according to WHO criteria, while all other cases of COVID-19 were considered mild to moderate (M-COVID). A group of healthy individuals who tested negative for SARS-CoV-2 served as a control group and was also evaluated with LDPM. RESULTS: Thirty-two patients with COVID-19 (25% S-COVID) and 14 controls were included. Basal microvascular flow was similar between M-COVID and controls (P = 0.69) but was higher in S-COVID than in controls (P = 0.005) and M-COVID patients (P = 0.01). The peak microvascular vasodilator response was markedly decreased in both patient groups (M-COVID, P = 0.001; S-COVID, P < 0.0001) compared to the healthy group. The percent increases in microvascular flow were markedly reduced in both patient groups (M-COVID, P < 0.0001; S-COVID, P < 0.0001) compared to controls. Patients with S-COVID had markedly higher concentrations of dissimilar proinflammatory cytokines and chemokines, compared to patients with M-COVID. CONCLUSIONS: In patients with COVID-19, especially with S-COVID, endothelium-dependent microvascular vasodilator responses are reduced, while serum cytokines and chemokines involved in the regulation of vascular function and inflammation are increased.


Assuntos
COVID-19/fisiopatologia , Quimiocinas/metabolismo , Citocinas/metabolismo , Endotélio Vascular/fisiopatologia , Microcirculação , Adulto , Idoso , Quimiocinas/sangue , Citocinas/sangue , Feminino , Voluntários Saudáveis , Hemodinâmica , Humanos , Imunoensaio , Fluxometria por Laser-Doppler , Masculino , Pessoa de Meia-Idade , Perfusão , Índice de Gravidade de Doença
11.
Microvasc Res ; 131: 104028, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32531352

RESUMO

Amidst the pandemic that has mesmerized the entire world, as it has not spared anyone according to any specific characteristic, some conditions have, in fact, emerged as risk factors for a complicated evolution of COVID-19. Older age, cardiovascular disease including hypertension, diabetes and pulmonary disease, have been associated with more severe presentations and/or adverse prognosis. In this letter to the editor, we propose that the link between cardiovascular and metabolic diseases and the higher incidence and worse prognosis of COVID-19 patients is the (micro) vascular endothelium.


Assuntos
Infecções por Coronavirus/complicações , Infecções por Coronavirus/patologia , Microcirculação , Pneumonia Viral/complicações , Pneumonia Viral/patologia , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Betacoronavirus , COVID-19 , Estado Terminal , Citocinas/metabolismo , Complicações do Diabetes , Endotélio Vascular/patologia , Hemodinâmica , Humanos , Hipertensão/complicações , Incidência , Inflamação , Lasers , Pandemias , Perfusão , Fenótipo , Prognóstico , Fatores de Risco , SARS-CoV-2
12.
Microvasc Res ; 129: 103962, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31786189

RESUMO

OBJECTIVE: This study evaluated the acute effect of a high-carbohydrate snack (HCS) on systemic microvascular function of healthy, young volunteers, using laser speckle contrast imaging (LSCI). METHODS: Cutaneous microvascular blood flow was assessed in the forearm with LSCI coupled to iontophoresis of acetylcholine, using increasing anodal currents, before and after (25 min) the ingestion of a HCS or water (control). Twenty volunteers (10 male) received a single HCS (70 g of carbohydrates) in the fasting state in the morning. RESULTS: The area under the curve (AUC) of acetylcholine-induced microvascular vasodilation increased from 17,847 ±â€¯4539 to 20,315 ±â€¯7168 arbitrary perfusion units/s (P = 0.03) after ingestion of a HCS, but was unchanged after the ingestion of water (P = 0.22). CONCLUSION: A single snack consisting on an acute oral load of carbohydrates induced a significant increase of endothelium-dependent microvascular vasodilation in healthy, young subjects.


Assuntos
Carboidratos da Dieta/administração & dosagem , Endotélio Vascular/fisiologia , Microcirculação , Microvasos/fisiologia , Pele/irrigação sanguínea , Lanches , Vasodilatação , Adolescente , Adulto , Velocidade do Fluxo Sanguíneo , Feminino , Antebraço , Voluntários Saudáveis , Humanos , Masculino , Fluxo Sanguíneo Regional , Fatores de Tempo , Adulto Jovem
13.
Heart Lung Circ ; 29(11): 1596-1602, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32972810

RESUMO

The recently described severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected millions of people, with thousands of fatalities. It has prompted global efforts in research, with focus on the pathophysiology of coronavirus disease-19 (COVID-19), and a rapid surge of publications. COVID-19 has been associated with a myriad of clinical manifestations, including the lungs, heart, kidneys, central nervous system, gastrointestinal system, skin, and blood coagulation abnormalities. The endothelium plays a key role in organ dysfunction associated with severe infection, and current data suggest that it is also involved in SARS-CoV-2-induced sepsis. This critical review aimed to address a possible unifying mechanism underlying the diverse complications of COVID-19: microvascular dysfunction, with emphasis on the renin-angiotensin system. In addition, research perspectives are suggested in order to expand understanding of the pathophysiology of the infection.


Assuntos
Infecções por Coronavirus , Microvasos , Pandemias , Pneumonia Viral , Sistema Renina-Angiotensina/fisiologia , Betacoronavirus/fisiologia , COVID-19 , Infecções por Coronavirus/metabolismo , Infecções por Coronavirus/fisiopatologia , Humanos , Microvasos/metabolismo , Microvasos/fisiopatologia , Microvasos/virologia , Pneumonia Viral/metabolismo , Pneumonia Viral/fisiopatologia , SARS-CoV-2
14.
Cell Physiol Biochem ; 53(4): 713-730, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31599538

RESUMO

BACKGROUND/AIMS: Renal injury related to hypertension is characterized by glomerular and tubulointerstitial damage. The overactivation of the renin-angiotensin system mainly by angiotensin II (AII) seems to be a main contributor to progressive renal fibrosis. Epithelial to mesenchymal transition (EMT) is a mechanism that promotes renal fibrosis. Owing to heat shock protein 70 (Hsp70) cytoprotective properties, the chaperone exhibits an important potential as a therapeutic target. We investigate the role of Hsp70 on Angiotensin II induced epithelial mesenchymal transition within the Losartan effect in proximal tubule cells (PTCs) from a genetic model of hypertension in rats (SHR). METHODS: Primary cell culture of PTCs from SHR and Wistar Kyoto (WKY) rats were stimulated with AII, treated with Losartan (L), (L+AII) or untreated (Cc). The functional Hsp70 role in Losartan effect, after silencing its expression by cell transfection, was determined by Immunofluorescence; Western blotting; Gelatin Zymography assays; Scratch wound assays; flow cytometry; and Live Cell Time-lapse microscopy. RESULTS: (L) and (L+AII) treatments induced highly organized actin filaments and increased cortical actin in SHR PTCs. However, SHR PTCs (Cc) and (AII) treated cells showed disorganized actin. After Hsp72 knockdown in SHR PTCs, (L) was unable to stabilize the actin cytoskeleton. We demonstrated that (L) and (L+AII) increased E-cadherin levels and decreased vinculin, α-SMA, vimentin, pERK, p38 and Smad2-3 activation compared to (AII) and (Cc) SHR PTCs. Moreover, (L) inhibited MMP-2 and MMP-9 secretion, reduced migration and cellular displacement, stabilizing intercellular junctions. Notably, (L) treatment in shHsp72 knockdown SHR PTCs showed results similar to SHR PTCs (Cc). CONCLUSION: Our results demonstrate that Losartan through Hsp70 inhibits the EMT induced by AII in proximal tubule cells derived from SHR.


Assuntos
Angiotensina II/farmacologia , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Proteínas de Choque Térmico HSP70/metabolismo , Losartan/farmacologia , Citoesqueleto de Actina/efeitos dos fármacos , Animais , Caderinas/metabolismo , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Adesões Focais/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Proteínas de Choque Térmico HSP70/antagonistas & inibidores , Proteínas de Choque Térmico HSP70/genética , Túbulos Renais Proximais/citologia , Túbulos Renais Proximais/metabolismo , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Vinculina/metabolismo
16.
Cytokine ; 121: 154732, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31153054

RESUMO

BACKGROUND: The inflammatory response of the host to Shiga toxin and/or lipopolysaccharide (LPS) of Escherichia coli (E. coli) is included in (HUS). The TLR4-LPS complex is internalized and TLR4 induced inflammatory signaling is stopped by targeting the complex for degradation. Rab7b, a small guanosine triphosphatase (GTPase) expressed in monocytes, regulates the later stages of the endocytic pathway. OBJECTIVE: we studied the Rab7b participation on the TLR4 endocytic pathway and its effect on monocyte cytokine production along the acute course of pediatric Shiga toxin-associated HUS. METHODS AND RESULTS: Monocytes were identified according to their positivity in CD14 expression. Surface TLR4 expression in monocytes from 18 HUS patients significantly increased by day 1 to 6, showing the highest increase on day 4 compared to monocytes of 10 healthy children. Significant higher surface TLR4 expression was accompanied by increased proinflammatory intracellular cytokines, tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6). In contrast, after these time points, surface TLR4 expression and intracellular TNF-α levels, returned to near control levels after 10 days. Furthermore, confocal immunofluorescence microscopy proved colocalization of increased intracellular TLR4/Rab7b determined by Pearson's coefficient in monocytes from HUS patients from day 1 on the highest colocalization of both proteins by day 4. Decreased TLR4/Rab7b colocalization was shown 10 days after HUS onset. CONCLUSION: The colocalization of TLR4 and Rab7b allows us to suggest Rab7b participation in the control of the TLR4 endocytic pathway in HUS patient monocytes. A consequential fall in cytokine production throughout the early follow up of HUS is demonstrated.


Assuntos
Endocitose , Síndrome Hemolítico-Urêmica/metabolismo , Síndrome Hemolítico-Urêmica/patologia , Toxina Shiga/metabolismo , Receptor 4 Toll-Like/metabolismo , Proteínas rab de Ligação ao GTP/metabolismo , Doença Aguda , Criança , Pré-Escolar , Citocinas/sangue , Seguimentos , Síndrome Hemolítico-Urêmica/sangue , Humanos , Lactente , Receptores de Lipopolissacarídeos/metabolismo , Monócitos/metabolismo , proteínas de unión al GTP Rab7
17.
BMC Complement Altern Med ; 18(1): 329, 2018 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-30541524

RESUMO

BACKGROUND: Little is studied about complications related to probiotic ingestion. This study proposes to present a synthesis and critical evaluation of the reports and series of cases on the infectious complications related to the ingestion of probiotics, which can raise awareness for the prescribing and use of probiotics for certain groups of patients. METHODS: Systematic review of reports and series of cases researched in the PubMed, SciELO and Scopus databases published until August 2018. The references of the articles were investigated manually for the search of cross references. SPSS version 23.0 was used for descriptive statistics and univariate analysis. RESULTS: We found 60 case reports and 7 case series, making up a total of 93 patients. Fungemia was the most common infectious complications with 35 (37.6%) cases. The genus Saccharomyces was the most frequent with 47 (50.6%) cases, followed by Lactobacillus, Bifidobacterium, Bacillus, Pedioccocus and Escherichia with 26 (27.9%), 12 (12.8%), 5 (5.4%), 2 (2.2%) and 1 (1.1%) case, respectively. Adults over 60 years of age, Clostridium difficile colitis, antibiotic use and Saccharomyces infections were associated with overall mortality. HIV infections, immunosuppressive drugs, solid organ transplantation, deep intravenous lines, enteral or parenteral nutrition were not associated with death. CONCLUSION: The use of probiotics cannot be considered risk-free and should be carefully evaluated for some patient groups. TRIAL REGISTRATION: CRD42016042289.


Assuntos
Infecções por Bactérias Gram-Positivas/etiologia , Micoses/etiologia , Probióticos/efeitos adversos , Administração Oral , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Bifidobacterium , Criança , Pré-Escolar , Feminino , Infecções por Bactérias Gram-Positivas/microbiologia , Humanos , Lactente , Recém-Nascido , Lactobacillus , Masculino , Pessoa de Meia-Idade , Micoses/microbiologia , Probióticos/administração & dosagem , Saccharomyces , Adulto Jovem
18.
Cardiology ; 137(4): 231-236, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28467991

RESUMO

OBJECTIVE: To evaluate endothelial progenitor cells (EPCs) and systemic microvascular function in patients with severe hypercholesterolemia, comparing patients with the definite familial hypercholesterolemia (FH) phenotype (DFH) or probable/possible FH phenotype (PFH). There is a large spectrum of atherosclerotic disease between these two clinical phenotypes of FH, and to acquire further knowledge of the pathophysiology of vascular disease in both is desirable. METHODS: Subjects with severe hypercholesterolemia, defined as low-density lipoprotein cholesterol (LDL-C) >190 mg/dL, were classified as DFH or PFH and underwent measurement of the number of EPCs by flow cytometry and evaluation of cutaneous microvascular reactivity using a laser speckle contrast-imaging system with iontophoresis of acethylcholine (ACh) or sodium nitroprusside. EPCs were defined as CD45- or CD45low, CD34+CD133+CD309+ cells. Categorical variables were compared using Fisher test and continuous variables with Student t test or Mann-Whitney test, and a value of p < 0.05 was considered statistically significant. RESULTS: Patients with DFH had higher LDL-C than those with PFH. There was no difference in the median number of EPCs between patients with DFH or PFH, but there was a significant reduction of endothelial-dependent, ACh-induced vasodilatation in the former. CONCLUSION: Patients with DFH have impaired microvascular endothelial-dependent vasodilatation compared to those with PFH, indicating more severe vascular disease in the former.


Assuntos
LDL-Colesterol/sangue , Células Progenitoras Endoteliais/citologia , Endotélio Vascular/fisiopatologia , Hipercolesterolemia/fisiopatologia , Hiperlipoproteinemia Tipo II/fisiopatologia , Adulto , Idoso , Feminino , Citometria de Fluxo , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Estudos Prospectivos , Vasodilatação
19.
Toxicol Appl Pharmacol ; 313: 57-67, 2016 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-27751938

RESUMO

A series of 31 pentacyclic triterpenoids isolated from the root barks of Celastrus vulcanicola and Maytenus jelskii were tested for cytotoxicity and inhibitory activity against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 macrophages. Compounds 18 (C18) and 25 (C25) exhibited significant inhibition of LPS-induced NO release at 50 and 25µM concentrations, respectively, and decreased mRNAs of pro-inflammatory cytokines. At the molecular level, C18 neither inhibited LPS-mediated phosphorylation of mitogen activated protein kinases (MAPKs) nor nuclear translocation of nuclear factor kappa beta (NFκB). Instead, C18 enhanced and prolonged nuclear translocation of nuclear factor-erythroid 2-related factor 2 (Nrf2) and increased the expression of its target genes including hemeoxigenase 1 (HO1). C25 efficiently inhibited LPS-mediated phosphorylation of JNK, p38 and ERK, without affecting NFκB or Nrf2 signaling pathways. Both compounds reduced LPS-mediated processing of caspase-1 and the cleavage of interleukin 1ß (IL1ß) proform, reflecting their ability to target the inflammasome. C25 also counteracted LPS effects on iNOS expression and pro-inflammatory cytokines mRNA levels in Bv-2 microglial cells. The anti-inflammatory effect of both compounds was also assessed in human macrophages. Our results suggest that triterpenoids C18 and C25 possess anti-inflammatory effects, which may be therapeutically relevant for diseases linked to inflammation.


Assuntos
Anti-Inflamatórios/farmacologia , Lipopolissacarídeos/toxicidade , Macrófagos/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Triterpenos/farmacologia , Animais , Caspase 1/metabolismo , Linhagem Celular , Indução Enzimática , Interleucina-1beta/metabolismo , Macrófagos/metabolismo , Camundongos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Óxido Nítrico Sintase Tipo II/biossíntese , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Fosforilação , RNA Mensageiro/genética
20.
Clin Transplant ; 30(9): 1178-81, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27411082

RESUMO

The notable evolution of heart transplant (HTX) has paralleled the capacity of diagnosing rejection and, consequently, initiating timely treatment. Acute cellular rejection, diagnosed by endomyocardial biopsy, is the most frequent in the first 6 months after HTX. HLA matching is not routinely performed in HTX due to the absence of consensus regarding its usefulness. However, the use of HLA typing might be underscored if it could predict an increased risk of rejection. Therefore, the aim of this study was to evaluate, at a public cardiology center in Brazil, the association between HLA mismatches and the incidence of acute cellular rejection in the first 6 months after HTX. Data were obtained from hospital records and from the National Transplant System. Overall, there was no association between the number of HLA mismatches and the frequency of acute cellular rejection, but there was a tendency toward a higher incidence of rejection with HLA-DR incompatibility.


Assuntos
Países em Desenvolvimento , Rejeição de Enxerto/imunologia , Transplante de Coração/efeitos adversos , Histocompatibilidade/imunologia , Doença Aguda , Biópsia , Brasil/epidemiologia , Feminino , Rejeição de Enxerto/diagnóstico , Rejeição de Enxerto/epidemiologia , Sobrevivência de Enxerto , Teste de Histocompatibilidade , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
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