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1.
Biochim Biophys Acta Bioenerg ; 1865(3): 149046, 2024 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-38642871

RESUMO

The respiratory chain alternative enzymes (AEs) NDX and AOX from the tunicate Ciona intestinalis (Ascidiacea) have been xenotopically expressed and characterized in human cells in culture and in the model organisms Drosophila melanogaster and mouse, with the purpose of developing bypass therapies to combat mitochondrial diseases in human patients with defective complexes I and III/IV, respectively. The fact that the genes coding for NDX and AOX have been lost from genomes of evolutionarily successful animal groups, such as vertebrates and insects, led us to investigate if the composition of the respiratory chain of Ciona and other tunicates differs significantly from that of humans and Drosophila, to accommodate the natural presence of AEs. We have failed to identify in tunicate genomes fifteen orthologous genes that code for subunits of the respiratory chain complexes; all of these putatively missing subunits are peripheral to complexes I, III and IV in mammals, and many are important for complex-complex interaction in supercomplexes (SCs), such as NDUFA11, UQCR11 and COX7A. Modeling of all respiratory chain subunit polypeptides of Ciona indicates significant structural divergence that is consistent with the lack of these fifteen clear orthologous subunits. We also provide evidence using Ciona AOX expressed in Drosophila that this AE cannot access the coenzyme Q pool reduced by complex I, but it is readily available to oxidize coenzyme Q molecules reduced by glycerophosphate oxidase, a mitochondrial inner membrane-bound dehydrogenase that is not involved in SCs. Altogether, our results suggest that Ciona AEs might have evolved in a mitochondrial inner membrane environment much different from that of mammals and insects, possibly without SCs; this correlates with the preferential functional interaction between these AEs and non-SC dehydrogenases in heterologous mammalian and insect systems. We discuss the implications of these findings for the applicability of Ciona AEs in human bypass therapies and for our understanding of the evolution of animal respiratory chain.


Assuntos
Ciona intestinalis , Proteínas Mitocondriais , Fosforilação Oxidativa , Animais , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Ciona intestinalis/genética , Ciona intestinalis/enzimologia , Humanos , Oxirredutases/genética , Oxirredutases/metabolismo , Subunidades Proteicas/metabolismo , Subunidades Proteicas/genética , Drosophila melanogaster/genética , Drosophila melanogaster/enzimologia , Urocordados/genética , Urocordados/enzimologia , Transporte de Elétrons , Complexo I de Transporte de Elétrons/metabolismo , Complexo I de Transporte de Elétrons/genética , Filogenia , Proteínas de Plantas
2.
Phys Chem Chem Phys ; 26(17): 13172-13181, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38630106

RESUMO

Transition metal nanoclusters can exhibit unique and tunable properties which result not only from their chemical composition but also from their atomic packing and quantized electronic structures. Here, we introduce a promising family of bimetallic TM@Ti12, TM@Zr12, and TM@Hf12 nanoclusters with icosahedral geometry, where TM represents an atom from groups 3 to 12. Density functional theory calculations show that their stability can be explained with familiar concepts of metal cluster electronic and atomic shell structures. The magnetic properties of these quasispherical clusters are entirely consistent with superatom electronic shells and Hund's rules, and can be tuned by the choice of the TM dopant. The computed cluster atomization energies were analyzed in terms of the elements' cohesive energy, Ecoh, and contributions from geometric distortion, Edis, surface energy, Es, and ionic bonding, Ei. Some clusters have anomalous stability relative to Ecoh + Edis + Es + Ei. We attribute this to superatomic character associated with a favorable atomic and electronic shell structure. This raises the possibility of designing stable superatoms and materials with tailored electronic and magnetic properties.

3.
Genet Mol Biol ; 47(1): e20230202, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38446983

RESUMO

Drosophila melanogaster is undoubtedly one of the most useful model organisms in biology. Initially used in solidifying the principles of heredity, and establishing the basic concepts of population genetics and of the synthetic theory of evolution, it can currently offer scientists much more: the possibility of investigating a plethora of cellular and biological mechanisms, from development and function of the immune system to animal neurogenesis, tumorigenesis and beyond. Extensive resources are available for the community of Drosophila researchers worldwide, including an ever-growing number of mutant, transgenic and genomically-edited lines currently carried by stock centers in North America, Europe and Asia. Here, we provide evidence for the importance of stock centers in sustaining the substantial increase in the output of Drosophila research worldwide in recent decades. We also discuss the challenges that Brazilian Drosophila scientists face to keep their research projects internationally competitive, and argue that difficulties in importing fly lines from international stock centers have significantly stalled the progression of all Drosophila research areas in the country. Establishing a local stock center might be the first step towards building a strong local Drosophila community that will likely contribute to all areas of life sciences research.

4.
Dalton Trans ; 53(2): 746-752, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38086661

RESUMO

The presented simulation protocol provides a solid foundation for exploring two-dimensional materials. Taking the TiBr2 2H monolayer as an example, this material displays promising TMDC-like optical and excitonic properties, making it an excellent candidate for optoelectronic and valleytronic applications. The direct band gap semiconductor (1.19 eV) is both structurally and thermodynamically stable, with spin-orbit coupling effects revealing a broken mirror symmetry in the K and K' valleys of the band structure, as confirmed by opposite values of the Berry curvature. A direct and bright exciton ground state was found, with an exciton binding energy of 0.56 eV. The study also revealed an optical helicity selection rule, suggesting selectivity in the valley excitation by specific circular light polarizations.

5.
Burns ; 49(8): 1900-1906, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37821281

RESUMO

OBJECTIVES: To evaluate the loss of lean mass in patients with burns using ultrasonography of the quadriceps muscle of the thigh. METHODS: A prospective longitudinal study was conducted using ultrasound of the quadriceps muscle of the thigh to assess the change in thickness in millimeters on days 1, 3 and 7 after study enrollment in 45 patients with burns who were admitted to a burn center (BTC) of a university hospital between April 2020 and September 2021. Patients burns on the thighs, which made it difficult to undertake examinations, were excluded. Depending on where they were admitted, patients were divided into ward and intensive care unit (ICU) patients. ICU patients were considered to have more severe injuries. The general data collected included age, sex, weight, height, area of body surface burn, burn degree and etiology, and airway injury. The data collected for all patients during hospitalization at the BTC were as follows: existence of chronic illness, requirement for mechanical ventilation, Simplified Acute Physiology Score 3 (SAPS 3) and Sequential Organ Failure Assessment (SOFA) on the first day of hospitalization in an intensive care bed in the burn treatment unit (BTU), health-related infection, feeding route, length of hospital stay, and time spent in the BTU. RESULTS: Loss of muscle thickness was observed in all patients between days 1 and 7. The median thickness for all patients on day 1 was 24.50 mm (ITQ 21.22-30.85) and on day 7 it was 18.80 (ITQ 16.07-23.62), with P = 0.0001. The variation in thigh quadricep muscle thickness between day 1 and day 3, a median of - 2.80 mm (ITQ - 3.52-2.02) was obtained for patients on the ward and - 2.50 mm (ITQ - 3.92 to - 1.47) for ICU patients. Between day 3 and day 7, the variation was - 2.55 mm (ITQ - 4.55 to - 1.25) for ward patients and - 2.10 mm (ITQ - 3.12 to - 1.15) for ICU patients. The median thickness variation assessed between day 1 and day 7 was - 4.95 mm (ITQ - 8.25 to - 3.70) for patients on the ward and - 4.40 mm (ITQ - 7, 35 to - 2.90) for ICU patients. A correlation was observed between the variation in muscle thickness in the interval between day 1 to day 3 and age (P = 0.035). CONCLUSIONS: Muscle loss occurred early and rapidly within the first seven days of hospitalization, reflecting the impact of burn injury on nutritional risk. An association was observed between muscle thickness loss and age, but no association was observed with the extent of burn, length of hospital stay, occurrence of health-related infections or mortality. These findings suggest the importance of monitoring muscle loss in these patients in planning nutritional therapy, early mobilization, and prevention of complications.


Assuntos
Queimaduras , Humanos , Estudos Prospectivos , Estudos Longitudinais , Queimaduras/diagnóstico por imagem , Hospitais Universitários , Ultrassonografia , Estudos Retrospectivos , Unidades de Terapia Intensiva
6.
Skinmed ; 21(4): 257-262, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37771016

RESUMO

The use of enzyme hyaluronidase to treat the complications of different brands of hyaluronic acid (HA) dermal fillers is increasing in the same proportion as the number of nonsurgical cosmetic procedures. Guidelines for diagnosing and treating complications remain controversial and are primarily based on anecdotal reports and small case series. We proposed approaching HA-related complications based on our clinical research and observations of treating more than 200 patients and providing a practical guide for the thoughtful use of hyaluronidase according to adverse events. Standardization of hyaluronidase dose and concentration is beneficial for better outcomes and future comparative analyses of the results of this treatment worldwide. The use of hyaluronidase is increasing for the reversal of the clinical manifestations of complications caused by HA fillers, although a consensus is lacking. We propose using different doses and concentrations of hyaluronidase to focus on selected anatomic areas considering properties of the product and pathogenesis of each complication.

7.
An Acad Bras Cienc ; 95(2): e20201688, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37341266

RESUMO

Industrial egg residue (IER) possesses substantial concentrations of calcium and crude protein. The objective of this study was to measure the digestibility and performance of broilers when IER was added to the feed. Four treatments were tested, which caused increasing replacement of calcitic limestone by IER (0, 35, 70 and 100%) during a 42-day production cycle. First, total bird excreta were collected from broilers with and without IER, and we determined dry matter digestibility, apparent metabolizable energy (AME), calcium, and nitrogen retention. The IER presented 7.5% of crude protein, 31% of calcium, 209 kcal/kg of AME and the digestibility coefficients for dry matter, crude protein, and calcium were calculated at 83.95%, 86.20%, and 67%, respectively. After the digestibility test, the effects of IER on performance, carcass and meat yield were evaluated. No significant differences between the treatments were found in terms of performance (weight gain, feed conversion, consumption, and mortality), and no differences were found in terms of carcass or meat yield. A linear decrease in the percentage of abdominal fat was observed with increasing inclusion of IER in feed. These findings suggest that IER can totally replace limestone (calcium carbonate) in broiler diets.


Assuntos
Cálcio , Galinhas , Animais , Carbonato de Cálcio , Carne , Aumento de Peso
8.
J Vector Ecol ; 48(1): 12-18, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37255355

RESUMO

Vector control has been an essential strategy in Brazil to manage vector-borne diseases, and the use of insecticides plays an important role in this effort. Pyriproxyfen (PPF) has become a common insect growth regulator used to control juvenile stages of mosquitoes by disturbing their growth and development. This study assesses the susceptibility and resistance status of Brazilian Ae. aegypti populations that previously showed low resistance levels to PPF. Eggs of Ae. aegypti were collected from six cities located in the northeast states of Ceará (Quixadá, Icó, and Juazeiro do Norte), and Bahia (Itabuna, Brumado, and Serrinha). We used the Ae. aegypti Rockefeller strain as an experimental control and a strain known to be susceptible to insecticides. Inhibition of emergence rates by 50% of Ae. aegypti populations varied from 0.0098-0.046 µg/L. Mosquitoes from Icó, Serrinha, and Brumado showed low resistance levels [resistance ratio (RR50) = 2.33, 4.52, and 4.83, respectively], whereas moderate levels of resistance were detected in populations from Juazeiro do Norte (RR50=5.83) and Itabuna (RR50=7.88). Aedes aegypti collected from the Quixadá population showed a high resistance level to pyriproxyfen (RR50=11). The evolution of resistance in Brazilian Ae. aegypti populations to PPF can compromise vector control efforts. Continuous monitoring of insecticide resistance in Ae. aegypti is essential for making timely management decisions for effective vector control and management.


Assuntos
Aedes , Inseticidas , Piretrinas , Animais , Inseticidas/farmacologia , Resistência a Inseticidas , Brasil/epidemiologia , Hormônios Juvenis/farmacologia , Mosquitos Vetores , Piretrinas/farmacologia
9.
Skinmed ; 21(1): 27-33, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36987823

RESUMO

The number of patients developing sterile abscesses because of hyaluronic acid (HA) filler procedures has increased for unknown reasons. We described this adverse reaction after filling with Juvederm Volux®, the latest innovative product in the Vycross range of technology. We presented five patients with recalcitrant sterile abscesses after filling with Juvederm Volux® who did not respond to the traditional therapy but whose lesions were resolved with the "Munhoz-Cavallieri lavage protocol" developed and recently published by the present authors. (SKINmed. 2023;21:27-33).


Assuntos
Técnicas Cosméticas , Humanos , Abscesso/tratamento farmacológico , Ácido Hialurônico/efeitos adversos
10.
Biosci Rep ; 42(11)2022 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-36254835

RESUMO

All 37 mitochondrial DNA (mtDNA)-encoded genes involved with oxidative phosphorylation and intramitochondrial protein synthesis, and several nuclear-encoded genes involved with mtDNA replication, transcription, repair and recombination are conserved between the fruit fly Drosophila melanogaster and mammals. This, in addition to its easy genetic tractability, has made Drosophila a useful model for our understanding of animal mtDNA maintenance and human mtDNA diseases. However, there are key differences between the Drosophila and mammalian systems that feature the diversity of mtDNA maintenance processes inside animal cells. Here, we review what is known about mtDNA maintenance in Drosophila, highlighting areas for which more research is warranted and providing a perspective preliminary in silico and in vivo analyses of the tissue specificity of mtDNA maintenance processes in this model organism. Our results suggest new roles (or the lack thereof) for well-known maintenance proteins, such as the helicase Twinkle and the accessory subunit of DNA polymerase γ, and for other Drosophila gene products that may even aid in shedding light on mtDNA maintenance in other animals. We hope to provide the reader some interesting paths that can be taken to help our community show how Drosophila may impact future mtDNA maintenance research.


Assuntos
DNA Mitocondrial , Proteínas de Drosophila , Animais , Humanos , DNA Mitocondrial/genética , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Mitocôndrias/genética , Mitocôndrias/metabolismo , DNA Polimerase gama/genética , DNA Polimerase gama/metabolismo , Proteínas de Drosophila/metabolismo , Replicação do DNA/genética , Proteínas Mitocondriais/genética , Mamíferos/metabolismo
11.
Viruses ; 14(7)2022 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-35891468

RESUMO

Arbovirus infections are increasingly important causes of disease, whose spectrum of neurological manifestations are not fully known. This study sought to retrospectively assess the incidence of arboviruses in cerebrospinal fluid samples of patients with neurological symptoms to inform diagnosis of central and peripheral nervous system disorders. A total of 255 cerebrospinal fluid (CSF) samples collected from January 2016 to December 2017 were tested for dengue virus (DENV 1-4), Zika virus (ZIKV), and Chikungunya virus (CHIKV) in addition to other neurotropic arboviruses of interest, using genetic and serologic assays. Of the 255 CSF samples analyzed, 3.53% (09/255) were positive for arboviruses presenting mainly as meningitis, encephalitis, and cerebrovascular events, of which ZIKV was detected in 2.74% (7/255), DENV in 0.78% (2/255), in addition to an identified ILHV infection that was described previously. All the cases were detected in adults aged 18 to 74 years old. Our findings highlight the scientific and clinical importance of neurological syndromes associated with arboviruses and demonstrate the relevance of specific laboratory methods to achieve accurate diagnoses as well as highlight the true dimension of these diseases to ultimately improve public health planning and medical case management.


Assuntos
Infecções por Arbovirus , Arbovírus , Febre de Chikungunya , Dengue , Doenças do Sistema Nervoso , Infecção por Zika virus , Zika virus , Adolescente , Adulto , Idoso , Infecções por Arbovirus/epidemiologia , Arbovírus/genética , Brasil/epidemiologia , Humanos , Pessoa de Meia-Idade , Doenças do Sistema Nervoso/complicações , Doenças do Sistema Nervoso/epidemiologia , Estudos Retrospectivos , Adulto Jovem , Zika virus/genética
12.
J Cosmet Dermatol ; 21(11): 5562-5568, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35638403

RESUMO

BACKGROUND: In recent years, fillers procedures with hyaluronic acid (HA) have grown significantly. Despite HA relative safety, the number of cases of complications after injections has grown, and in many of which, we are not aware of or have little control over. AIMS: In this article, the authors describe a new adverse reaction after filling with HA injection, the sterile abscess. PATIENTS/METHODS: We present eight patients with similar clinical, laboratory, and ultrasound characteristics for sterile abscess and report a new therapeutic modality for it. RESULTS: All cases were treated with "Munhoz-Cavallieri Lavage Protocol" procedure with complete resolution. CONCLUSIONS: "Munhoz-Cavallieri Lavage Protocol" serves as a guideline in diagnosis and management of sterile abscess.


Assuntos
Técnicas Cosméticas , Preenchedores Dérmicos , Humanos , Ácido Hialurônico/efeitos adversos , Abscesso/diagnóstico por imagem , Abscesso/etiologia , Injeções , Preenchedores Dérmicos/efeitos adversos , Técnicas Cosméticas/efeitos adversos
13.
Brain Behav Immun ; 97: 260-274, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34390806

RESUMO

Zika virus (ZIKV) has the ability to cross placental and brain barriers, causing congenital malformations in neonates and neurological disorders in adults. However, the pathogenic mechanisms of ZIKV-induced neurological complications in adults and congenital malformations are still not fully understood. Gas6 is a soluble TAM receptor ligand able to promote flavivirus internalization and downregulation of immune responses. Here we demonstrate that there is a correlation between ZIKV neurological complications with higher Gas6 levels and the downregulation of genes associated with anti-viral response, as type I IFN due to Socs1 upregulation. Also, Gas6 gamma-carboxylation is essential for ZIKV invasion and replication in monocytes, the main source of this protein, which was inhibited by warfarin. Conversely, Gas6 facilitates ZIKV replication in adult immunocompetent mice and enabled susceptibility to transplacental infection. Our data indicate that ZIKV promotes the upregulation of its ligand Gas6, which contributes to viral infectivity and drives the development of severe adverse outcomes during ZIKV infection.


Assuntos
Doenças do Sistema Nervoso , Infecção por Zika virus , Zika virus , Animais , Feminino , Humanos , Camundongos , Placenta , Gravidez , Replicação Viral , Infecção por Zika virus/complicações
14.
J Environ Public Health ; 2021: 8230789, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34341668

RESUMO

Yellow Fever Virus (YFV) reemergence in Brazil was followed by human suffering and the loss of biodiversity of neotropical simians on the Atlantic coast. The underlying mechanisms were investigated with special focus on distinct landscape fragmentation thresholds in the affected municipalities. An ecological study in epidemiology is employed to assess the statistical relationship between events of YFV and forest fragmentation in municipal landscapes. Negative binomial regression model showed that highly fragmented forest cover was associated with an 85% increase of events of YFV in humans and simians (RR = 1.85, CI 95% = 1.24-2.75, p=0.003) adjusted by vaccine coverage, population size, and municipality area. Intermediate levels of forest cover combined with higher levels of forest edge densities contribute to the YFV dispersion and the exponential growth of YF cases. Strategies for forest conservation are necessary for the control and prevention of YF and other zoonotic diseases that can spillover from the fragmented forest remains to populated cities of the Brazilian Atlantic coast.


Assuntos
Febre Amarela , Animais , Brasil/epidemiologia , Humanos , Febre Amarela/epidemiologia , Vírus da Febre Amarela , Zoonoses
15.
J Physiol ; 599(11): 2969-2986, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33823064

RESUMO

KEY POINTS: The costs associated with immune and thermal responses may exceed the benefits to the host during severe inflammation. In this case, regulated hypothermia instead of fever can occur in rodents as a beneficial strategy to conserve energy for vital functions with consequent tissue protection and hypoxia prevention. We tested the hypothesis that this phenomenon is not exclusive to mammals, but extends to the other endothermic group, birds. A decrease in metabolic rate without any failure in mitochondrial respiration, nor oxygen delivery, is the main evidence supporting the regulated nature of endotoxin-induced hypothermia in chicks. Thermolytic mechanisms such as tachypnea and cutaneous vasodilatation can also be recruited to facilitate body temperature decrease under lipopolysaccharide treatment, especially in the cold. Our findings bring a new perspective for evolutionary medicine studies on energy trade-off in host defence because regulated hypothermia may be a phenomenon spread among vertebrates facing a severe immune challenge. ABSTRACT: A switch from fever to regulated hypothermia can occur in mammals under circumstances of reduced physiological fitness (e.g. sepsis) to direct energy to defend vital systems. Birds in which the cost to resist a pathogen is additive to the highest metabolic rate and body temperature (Tb ) among vertebrates may also benefit from regulated hypothermia during systemic inflammation. Here, we show that the decrease in Tb observed during an immune challenge in birds is a regulated hypothermia, and not a result of metabolic failure. We investigated O2 consumption (thermogenesis index), ventilation (respiratory heat loss), skin temperature (sensible heat loss) and muscle mitochondrial respiration (thermogenic tissue) during Tb fall in chicken chicks challenged with endotoxin [lipopolysaccharide (LPS)]. Chicks injected with LPS were also tested regarding the capacity to raise O2 consumption to meet an increased demand driven by 2,4-dinitrophenol. LPS decreased Tb and the metabolic rate of chicks without affecting muscle uncoupled, coupled and non-coupled mitochondrial respiration. LPS-challenged chicks were indeed capable of increasing metabolic rate in response to 2,4-dinitrophenol, indicating no O2 delivery limitation. Additionally, chicks did not attempt to prevent Tb from falling during hypothermia but, instead, activated cutaneous and respiratory thermolytic mechanisms, providing an additional cooling force. These data provide the first evidence of the regulated nature of the hypothermic response to endotoxin in birds. Therefore, it changes the current understanding of bird's thermoregulation during severe inflammation, indicating that regulated hypothermia is either a convergent trait for endotherms or a conserved response among vertebrates, which adds a new perspective for evolutionary medicine research.


Assuntos
Hipotermia , Animais , Temperatura Corporal , Regulação da Temperatura Corporal , Galinhas , Endotoxinas/toxicidade
16.
Methods Mol Biol ; 2281: 1-21, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33847949

RESUMO

Maintenance of genomes is fundamental for all living organisms. The diverse processes related to genome maintenance entail the management of various intermediate structures, which may be deleterious if unresolved. The most frequent intermediate structures that result from the melting of the DNA duplex are single-stranded (ss) DNA stretches. These are thermodynamically less stable and can spontaneously fold into secondary structures, which may obstruct a variety of genome processes. In addition, ssDNA is more prone to breaking, which may lead to the formation of deletions or DNA degradation. Single-stranded DNA-binding proteins (SSBs) bind and stabilize ssDNA, preventing the abovementioned deleterious consequences and recruiting the appropriate machinery to resolve that intermediate molecule. They are present in all forms of life and are essential for their viability, with very few exceptions. Here we present an introductory chapter to a volume of the Methods in Molecular Biology dedicated to SSBs, in which we provide a general description of SSBs from various taxa.


Assuntos
DNA de Cadeia Simples/química , DNA de Cadeia Simples/metabolismo , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Reparo do DNA , Replicação do DNA , Proteínas de Ligação a DNA/genética , Genes Essenciais , Modelos Moleculares , Conformação Molecular
17.
Methods Mol Biol ; 2281: 313-322, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33847968

RESUMO

Defects in mitochondrial DNA (mtDNA) maintenance may lead to disturbances in mitochondrial homeostasis and energy production in eukaryotic cells, causing diseases. During mtDNA replication, the mitochondrial single-stranded DNA-binding protein (mtSSB) stabilizes and protects the exposed single-stranded mtDNA from nucleolysis; perhaps more importantly, it appears to coordinate the actions of both the replicative mtDNA helicase Twinkle and DNA polymerase gamma at the replication fork. Here, we describe a helicase stimulation protocol to test in vitro the functional interaction between mtSSB and variant forms of Twinkle. We show for the first time that the C-terminal tail of Twinkle is important for such an interaction, and that it negatively regulates helicase unwinding activity in a salt-dependent manner.


Assuntos
DNA Helicases/química , DNA Helicases/metabolismo , DNA de Cadeia Simples/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas Mitocondriais/química , Proteínas Mitocondriais/metabolismo , Mutação , Sítios de Ligação , DNA Helicases/genética , Replicação do DNA , DNA Mitocondrial/química , DNA Mitocondrial/metabolismo , DNA de Cadeia Simples/química , Proteínas de Ligação a DNA/química , Humanos , Proteínas Mitocondriais/genética , Modelos Moleculares , Ligação Proteica , Conformação Proteica
18.
J Back Musculoskelet Rehabil ; 34(3): 363-370, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33459693

RESUMO

BACKGROUND: Pressure pain threshold (PPT) is decreased in several musculoskeletal disorders, giving indirect evidence regarding pain status. Despite the fact that PPT has been already proven to be reliable in patients with acute conditions, there is great variability of methods and results observed within studies, and only a few evidences confirming its reliability in chronic conditions. OBJECTIVE: The objective of this study was to determine the test-retest reliability of PPT in the neck and low back regions to discriminate individuals with neck or low back pain from healthy individuals. Additionally, one secondary aim was to establish the minimum detectable change (MDC) and the standard error of measurement for future clinical studies and interventions. METHODS: In this reliability study, 74 individuals (15 individuals from the neck pain and 17 from the neck control group; 21 individuals from the low back pain and 21 from the low back control group). PPT was measured in the neck region (suboccipital, trapezius and supraspinal muscles) and in the lower back region (paraspinal muscles in the levels of L1, L3 and L5). Intrarater reliability was assessed using intraclass correlation coeficient and Bland-Altman. RESULTS: Excellent intra-rater reliability was observed for both (ICC of 0.874 for the neck pain versus ICC of 0.895 in neck control group; ICC of 0.932 for the low back pain group versus ICC of 0.839 for the control group). A small bias was observed for all groups (-0.08 for the neck pain group versus 0.10 in the control group; and 0.32 in low back pain group versus 0.44 in the control group). Minimum detectable change of 0.63 kgf of neck pain and 1.21 kgf of low back pain was calculated. It was found difference in PPT between pain and control groups (p< 0.05). CONCLUSION: It may be suggested that the protocol with PPT is reliable and able to discriminate individuals with and without neck and low back pain with a minor measurement error. Therefore, this method may be used to detect possible progress after interventions in patients with neck or low back pain.


Assuntos
Dor Lombar/diagnóstico , Cervicalgia/diagnóstico , Limiar da Dor/fisiologia , Adolescente , Adulto , Feminino , Humanos , Dor Lombar/fisiopatologia , Masculino , Cervicalgia/fisiopatologia , Medição da Dor/métodos , Reprodutibilidade dos Testes , Adulto Jovem
19.
Curr Microbiol ; 78(2): 756-764, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33462632

RESUMO

In both Brazilian and European regulations, the impact assessment of sewage discharges into coastal waters is based on microbiological analyses of fecal indicators such as Escherichia coli, frequently used in prevision hydrodynamic models. However, the decay rates of E. coli vary depending on environmental conditions, and analysis may lead to inaccurate conclusions. This study aimed to analyze the decay of culturable and viable (but not culturable) E. coli in outdoor conditions, by creating microcosms inoculated with pre-treated sewage. The microcosms were filled with 9.88 L of filtered water (0.22 µm membrane), 3.5% salt, 0.1-0.2% BHI, and 1% bacterial suspension obtained by reverse filtration. PMA-qPCR of E. coli uidA gene and Colilert measurements were applied to evaluate population counts after 2 h, 4 h, and 26 h. After nine hours of exposure to solar radiation, the viable cells decreased to 2.76% (interpolated value) of the initial population, and the cultivable fraction of the viable population accounted for 0.50%. In the dark period, the bacteria grew again, and viable cells reached 8.54%, while cultivable cells grew to 48.14% of initial population. This behavior is possibly due to the use of nutrients recycled from dead cells. Likewise, populations of E. coli in sewage outfalls remain viable in the sediments, where resuspension can renew blooming.


Assuntos
Escherichia coli , Esgotos , Brasil , Escherichia coli/genética , Fezes , Reação em Cadeia da Polimerase em Tempo Real , Microbiologia da Água
20.
Nat Prod Res ; 35(18): 3083-3088, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31680555

RESUMO

Triplaris gardneriana is used by traditional medicine. The objective of this work was the leaves chemical study with isolate, identify and quantify the chemical constituent, validate the analytical method and evaluate the antibacterial activity. The ethyl acetate and chloroform fractions were subjected to column chromatography for isolation of the compounds quercetin and lupeol, respectively. For the identification, quantification of quercetin in the samples and validation of method were performed using HPLC-DAD. The antibacterial activity was evaluated by the microdilution method. The isolated phytochemicals are being reported for the first time in the species. The ethyl acetate fraction showed a higher content of quercetin with 9.967 ± 1.01 mg.g-1. The method was validated. The samples showed good antibacterial activity. In this study, quercetin was isolated and quantified in the species being a great alternative as a producer of this secondary metabolite, which can be safely applied in the quality control analysis.


Assuntos
Antibacterianos/farmacologia , Polygonaceae/química , Quercetina , Antibacterianos/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Extratos Vegetais , Folhas de Planta/química , Quercetina/isolamento & purificação , Quercetina/farmacologia
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