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1.
Eur J Med Chem ; 269: 116308, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38503166

RESUMO

Plasmodium multi-resistance, including against artemisinin, seriously threatens malaria treatment and control. Hence, new drugs are urgently needed, ideally targeting different parasitic stages, which are not yet targeted by current drugs. The SUB1 protease is involved in both hepatic and blood stages due to its essential role in the egress of parasites from host cells, and, as potential new target, it would meet the above criteria. We report here the synthesis as well as the biological and structural evaluation of substrate-based α-ketoamide SUB1 pseudopeptidic inhibitors encompassing positions P4-P2'. By individually substituting each position of the reference compound 1 (MAM-117, Ac-Ile-Thr-Ala-AlaCO-Asp-Glu (Oall)-NH2), we better characterized the structural determinants for SUB1 binding. We first identified compound 8 with IC50 values of 50 and 570 nM against Pv- and PfSUB1, respectively (about 3.5-fold higher potency compared to 1). Compound 8 inhibited P. falciparum merozoite egress in culture by 37% at 100 µM. By increasing the overall hydrophobicity of the compounds, we could improve the PfSUB1 inhibition level and antiparasitic activity, as shown with compound 40 (IC50 values of 12 and 10 nM against Pv- and PfSUB1, respectively, IC50 value of 23 µM on P. falciparum merozoite egress). We also found that 8 was highly selective towards SUB1 over three mammalian serine peptidases, supporting the promising value of this compound. Finally, several crystal 3D-structures of SUB1-inhibitor complexes, including with 8, were solved at high resolution to decipher the binding mode of these compounds.


Assuntos
Antimaláricos , Malária Falciparum , Malária , Parasitos , Animais , Subtilisina/metabolismo , Sequência de Aminoácidos , Plasmodium falciparum/metabolismo , Peptídeos , Malária Falciparum/parasitologia , Serina Proteases/metabolismo , Relação Estrutura-Atividade , Antimaláricos/farmacologia , Antimaláricos/química , Proteínas de Protozoários , Mamíferos/metabolismo
2.
mBio ; 15(3): e0019824, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38386597

RESUMO

Malaria symptoms are associated with the asexual multiplication of Plasmodium falciparum within human red blood cells (RBCs) and fever peaks coincide with the egress of daughter merozoites following the rupture of the parasitophorous vacuole (PV) and the RBC membranes. Over the last two decades, it has emerged that the release of competent merozoites is tightly regulated by a complex cascade of events, including the unusual multi-step activation mechanism of the pivotal subtilisin-like protease 1 (Sub1) that takes place in three different cellular compartments and remains poorly understood. Following an initial auto-maturation in the endoplasmic reticulum (ER) between its pro- and catalytic domains, the Sub1 prodomain (PD) undergoes further cleavages by the parasite aspartic protease plasmepsin X (PmX) within acidic secretory organelles that ultimately lead to full Sub1 activation upon discharge into the PV. Here, we report the crystal structure of full-length P. falciparum Sub1 (PfS1FL) and demonstrate, through structural, biochemical, and biophysical studies, that the atypical Plasmodium-specific Sub1 PD directly promotes the assembly of inactive enzyme homodimers at acidic pH, whereas Sub1 is primarily monomeric at neutral pH. Our results shed new light into the finely tuned Sub1 spatiotemporal activation during secretion, explaining how PmX processing and full activation of Sub1 can occur in different cellular compartments, and uncover a robust mechanism of pH-dependent subtilisin autoinhibition that plays a key role in P. falciparum merozoites egress from infected host cells.IMPORTANCEMalaria fever spikes are due to the rupture of infected erythrocytes, allowing the egress of Plasmodium sp. merozoites and further parasite propagation. This fleeting tightly regulated event involves a cascade of enzymes, culminating with the complex activation of the subtilisin-like protease 1, Sub1. Differently than other subtilisins, Sub1 activation strictly depends upon the processing by a parasite aspartic protease within acidic merozoite secretory organelles. However, Sub1 biological activity is required in the pH neutral parasitophorous vacuole, to prime effectors involved in the rupture of the vacuole and erythrocytic membranes. Here, we show that the unusual, parasite-specific Sub1 prodomain is directly responsible for its acidic-dependent dimerization and autoinhibition, required for protein secretion, before its full activation at neutral pH in a monomeric form. pH-dependent Sub1 dimerization defines a novel, essential regulatory element involved in the finely tuned spatiotemporal activation of the egress of competent Plasmodium merozoites.


Assuntos
Malária Falciparum , Plasmodium , Animais , Humanos , Subtilisina/metabolismo , Merozoítos/fisiologia , Dimerização , Proteínas de Protozoários/metabolismo , Malária Falciparum/parasitologia , Plasmodium falciparum/metabolismo , Eritrócitos/parasitologia , Concentração de Íons de Hidrogênio
3.
Microbiol Resour Announc ; 13(3): e0092823, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38385707

RESUMO

We present the complete genome sequence of Bradyrhizobium sp. 62B, a strain isolated from the root nodules of peanut plants that grow in central Argentina. The genome consists of 8.15 Mbp, distributed into a chromosome of 7.29 Mbp and a plasmid of 0.86 Mbp.

4.
Microbiol Resour Announc ; 12(10): e0058123, 2023 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-37772816

RESUMO

Here, we report the complete genome sequence of Mesorhizobium mediterraneum R31, a rhizobial strain recommended and used as a commercial inoculant for chickpea in Argentina. The genome consists of 7.25 Mb, distributed into four circular replicons: a chromosome of 6.72 Mbp and three plasmids of 0.29, 0.17, and 0.07 Mbp.

5.
Nat Microbiol ; 8(10): 1896-1910, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37679597

RESUMO

The order Corynebacteriales includes major industrial and pathogenic Actinobacteria such as Corynebacterium glutamicum or Mycobacterium tuberculosis. These bacteria have multi-layered cell walls composed of the mycolyl-arabinogalactan-peptidoglycan complex and a polar growth mode, thus requiring tight coordination between the septal divisome, organized around the tubulin-like protein FtsZ, and the polar elongasome, assembled around the coiled-coil protein Wag31. Here, using C. glutamicum, we report the discovery of two divisome members: a gephyrin-like repurposed molybdotransferase (Glp) and its membrane receptor (GlpR). Our results show how cell cycle progression requires interplay between Glp/GlpR, FtsZ and Wag31, showcasing a crucial crosstalk between the divisome and elongasome machineries that might be targeted for anti-mycobacterial drug discovery. Further, our work reveals that Corynebacteriales have evolved a protein scaffold to control cell division and morphogenesis, similar to the gephyrin/GlyR system that mediates synaptic signalling in higher eukaryotes through network organization of membrane receptors and the microtubule cytoskeleton.


Assuntos
Eucariotos , Mycobacterium tuberculosis , Eucariotos/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Divisão Celular , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/metabolismo
6.
Acta Crystallogr D Struct Biol ; 79(Pt 8): 721-734, 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37428845

RESUMO

The constant selection and propagation of multi-resistant Plasmodium sp. parasites require the identification of new antimalarial candidates involved in as-yet untargeted metabolic pathways. Subtilisin-like protease 1 (SUB1) belongs to a new generation of drug targets because it plays a crucial role during egress of the parasite from infected host cells at different stages of its life cycle. SUB1 is characterized by an unusual pro-region that tightly interacts with its cognate catalytic domain, thus precluding 3D structural analysis of enzyme-inhibitor complexes. In the present study, to overcome this limitation, stringent ionic conditions and controlled proteolysis of recombinant full-length P. vivax SUB1 were used to obtain crystals of an active and stable catalytic domain (PvS1Cat) without a pro-region. High-resolution 3D structures of PvS1Cat, alone and in complex with an α-ketoamide substrate-derived inhibitor (MAM-117), showed that, as expected, the catalytic serine of SUB1 formed a covalent bond with the α-keto group of the inhibitor. A network of hydrogen bonds and hydrophobic interactions stabilized the complex, including at the P1' and P2' positions of the inhibitor, although P' residues are usually less important in defining the substrate specificity of subtilisins. Moreover, when associated with a substrate-derived peptidomimetic inhibitor, the catalytic groove of SUB1 underwent significant structural changes, particularly in its S4 pocket. These findings pave the way for future strategies for the design of optimized SUB1-specific inhibitors that may define a novel class of antimalarial candidates.


Assuntos
Antimaláricos , Subtilisina , Plasmodium vivax , Antimaláricos/farmacologia , Antimaláricos/química , Inibidores Enzimáticos/farmacologia , Proteínas de Protozoários/química
7.
Microbiol Resour Announc ; 12(5): e0002123, 2023 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-37039639

RESUMO

We report the complete genome sequence of Burkholderia ambifaria strain Q53, an environmental rhizobacterium isolated from the rhizosphere of peanut plants. The genome consists of 7.4 Mbp distributed into three circular chromosomes and was determined using a hybrid long- and short-read assembly approach.

8.
Int J Mol Sci ; 24(8)2023 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-37108650

RESUMO

Wound healing (WH) is a complex multistep process in which a failure could lead to a chronic wound (CW). CW is a major health problem and includes leg venous ulcers, diabetic foot ulcers, and pressure ulcers. CW is difficult to treat and affects vulnerable and pluripathological patients. On the other hand, excessive scarring leads to keloids and hypertrophic scars causing disfiguration and sometimes itchiness and pain. Treatment of WH includes the cleaning and careful handling of injured tissue, early treatment and prevention of infection, and promotion of healing. Treatment of underlying conditions and the use of special dressings promote healing. The patient at risk and risk areas should avoid injury as much as possible. This review aims to summarize the role of physical therapies as complementary treatments in WH and scarring. The article proposes a translational view, opening the opportunity to develop these therapies in an optimal way in clinical management, as many of them are emerging. The role of laser, photobiomodulation, photodynamic therapy, electrical stimulation, ultrasound therapy, and others are highlighted in a practical and comprehensive approach.


Assuntos
Cicatriz Hipertrófica , Queloide , Úlcera por Pressão , Humanos , Cicatrização/fisiologia , Cicatriz Hipertrófica/patologia , Queloide/patologia , Modalidades de Fisioterapia/efeitos adversos
9.
Genes (Basel) ; 14(4)2023 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-37107693

RESUMO

The species delimitation of the marine bivalve species complex Aequiyoldia eightsii in South America and Antarctica is complicated by mitochondrial heteroplasmy and amplification bias in molecular barcoding. In this study, we compare different data sources (mitochondrial cytochrome c oxidase subunit I (COI) sequences; nuclear and mitochondrial SNPs). Whilst all the data suggest that populations on either side of the Drake Passage belong to different species, the picture is less clear within Antarctic populations, which harbor three distinct mitochondrial lineages (p-dist ≈ 6%) that coexist in populations and in a subset of individuals with heteroplasmy. Standard barcoding procedures lead to amplification bias favoring either haplotype unpredictably and thus overestimate the species richness with high confidence. However, nuclear SNPs show no differentiation akin to the trans-Drake comparison, suggesting that the Antarctic populations represent a single species. Their distinct haplotypes likely evolved during periods of temporary allopatry, whereas recombination eroded similar differentiation patterns in the nuclear genome after secondary contact. Our study highlights the importance of using multiple data sources and careful quality control measures to avoid bias and increase the accuracy of molecular species delimitation. We recommend an active search for mitochondrial heteroplasmy and haplotype-specific primers for amplification in DNA-barcoding studies.


Assuntos
Bivalves , DNA Mitocondrial , Humanos , Animais , DNA Mitocondrial/genética , Regiões Antárticas , Heteroplasmia , Bivalves/genética , Reação em Cadeia da Polimerase
10.
Front Physiol ; 14: 1083240, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36895632

RESUMO

When an organism makes a long-distance transition to a new habitat, the associated environmental change is often marked and requires physiological plasticity of larvae, juveniles, or other migrant stages. Exposing shallow-water marine bivalves (Aequiyoldia cf. eightsii) from southern South America (SSA) and the West Antarctic Peninsula (WAP) to changes in temperature and oxygen availability, we investigated changes in gene expression in a simulated colonization experiment of the shores of a new continent after crossing of the Drake Passage, and in a warming scenario in the WAP. Bivalves from SSA were cooled from 7°C (in situ) to 4°C and 2°C (future warmed WAP conditions), WAP bivalves were warmed from 1.5°C (current summer in situ) to 4°C (warmed WAP), gene expression patterns in response to thermal stress by itself and in combination with hypoxia were measured after 10 days. Our results confirm that molecular plasticity may play a vital role for local adaptation. Hypoxia had a greater effect on the transcriptome than temperature alone. The effect was further amplified when hypoxia and temperature acted as combined stressors. The WAP bivalves showed a remarkable ability to cope with short-term exposure to hypoxia by switching to a metabolic rate depression strategy and activating the alternative oxidation pathway, whilst the SSA population showed no comparable response. In SSA, the high prevalence of apoptosis-related differentially expressed genes especially under combined higher temperatures and hypoxia indicated that the SSA Aequiyoldia are operating near their physiological limits already. While the effect of temperature per se may not represent the single most effective barrier to Antarctic colonization by South American bivalves, the current distribution patterns as well as their resilience to future conditions can be better understood by looking at the synergistic effects of temperature in conjunction with short-term exposure to hypoxia.

11.
J Leukoc Biol ; 113(6): 588-603, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-36987875

RESUMO

Tuberculosis remains one of the leading public health problems in the world. The mechanisms that lead to the activation of the immune response against Mycobacterium tuberculosis have been extensively studied, with a focus on the role of cytokines as the main signals for immune cell communication. However, less is known about the role of other signals, such as extracellular vesicles, in the communication between immune cells, particularly during the activation of the adaptive immune response. In this study, we determined that extracellular vesicles released by human neutrophils infected with M. tuberculosis contained several host proteins that are ectosome markers. In addition, we demonstrated that extracellular vesicles released by human neutrophils infected with M. tuberculosis released after only 30 min of infection carried mycobacterial antigens and pathogen-associated molecular patterns, and we identified 15 mycobacterial proteins that were consistently found in high concentrations in extracellular vesicles released by human neutrophils infected with M. tuberculosis; these proteins contain epitopes for CD4 T-cell activation. We found that extracellular vesicles released by human neutrophils infected with M. tuberculosis increased the expression of the costimulatory molecule CD80 and of the coinhibitory molecule PD-L1 on immature monocyte-derived dendritic cells. We also found that immature and mature dendritic cells treated with extracellular vesicles released by human neutrophils infected with M. tuberculosis were able to induce IFN-γ production by autologous M. tuberculosis antigen-specific CD4 T cells, indicating that these extracellular vesicles acted as antigen carriers and transferred mycobacterial proteins to the antigen-presenting cells. Our results provide evidence that extracellular vesicles released by human neutrophils infected with M. tuberculosis participate in the activation of the adaptive immune response against M. tuberculosis.


Assuntos
Vesículas Extracelulares , Mycobacterium tuberculosis , Tuberculose , Humanos , Células Th1 , Neutrófilos , Monócitos , Células Dendríticas
12.
Proc Natl Acad Sci U S A ; 119(50): e2214599119, 2022 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-36469781

RESUMO

The bacterial cell wall is a multi-layered mesh, whose major component is peptidoglycan (PG), a sugar polymer cross-linked by short peptide stems. During cell division, a careful balance of PG synthesis and degradation, precisely coordinated both in time and space, is necessary to prevent uncontrolled destruction of the cell wall. In Corynebacteriales, the D,L endopeptidase RipA has emerged as a major PG hydrolase for cell separation, and RipA defaults have major implications for virulence of the human pathogens Mycobacterium tuberculosis and Corynebacterium diphtheriae. However, the precise mechanisms by which RipA mediates cell separation remain elusive. Here we report phylogenetic, biochemical, and structural analysis of the Corynebacterium glutamicum homologue of RipA, Cg1735. The crystal structures of full-length Cg1735 in two different crystal forms revealed the C-terminal NlpC/P60 catalytic domain obtruded by its N-terminal conserved coiled-coil domain, which locks the enzyme in an autoinhibited state. We show that this autoinhibition is relieved by the extracellular core domain of the transmembrane septal protein Cg1604. The crystal structure of Cg1604 revealed a (ß/α) protein with an overall topology similar to that of receiver domains from response regulator proteins. The atomic model of the Cg1735-Cg1604 complex, based on bioinformatical and mutational analysis, indicates that a conserved, distal-membrane helical insertion in Cg1604 is responsible for Cg1735 activation. The reported data provide important insights into how intracellular cell division signal(s), yet to be identified, control PG hydrolysis during RipA-mediated cell separation in Corynebacteriales.


Assuntos
Actinomycetales , Proteínas de Bactérias , Actinomycetales/citologia , Proteínas de Bactérias/metabolismo , Parede Celular/metabolismo , N-Acetil-Muramil-L-Alanina Amidase/genética , Peptidoglicano/metabolismo , Filogenia
13.
Microbiol Resour Announc ; 11(11): e0077922, 2022 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-36287006

RESUMO

We report the complete genome sequence of Mesorhizobium ciceri strain R30, a rhizobium strain recommended and used as a commercial inoculant for chickpea in Argentina. The genome consists of almost 7 Mb, distributed into two circular replicons: a chromosome of 6.49 Mb and a plasmid of 0.46 Mb.

14.
mBio ; 13(5): e0013422, 2022 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-36154281

RESUMO

Type VIIb secretion systems (T7SSb) were recently proposed to mediate different aspects of Firmicutes physiology, including bacterial pathogenicity and competition. However, their architecture and mechanism of action remain largely obscure. Here, we present a detailed analysis of the T7SSb-mediated bacterial competition in Bacillus subtilis, using the effector YxiD as a model for the LXG secreted toxins. By systematically investigating protein-protein interactions, we reveal that the membrane subunit YukC contacts all T7SSb components, including the WXG100 substrate YukE and the LXG effector YxiD. YukC's crystal structure shows unique features, suggesting an intrinsic flexibility that is required for T7SSb antibacterial activity. Overall, our results shed light on the role and molecular organization of the T7SSb and demonstrate the potential of B. subtilis as a model system for extensive structure-function studies of these secretion machineries. IMPORTANCE Type VII secretion systems mediate protein extrusion from Gram-positive bacteria and are classified as T7SSa and T7SSb in Actinobacteria and in Firmicutes, respectively. Despite the genetic divergence of T7SSa and T7SSb, the high degree of structural similarity of their WXG100 substrates suggests similar secretion mechanisms. Recent advances revealed the structures of several T7SSa cytoplasmic membrane complexes, but the molecular mechanism of secretion and the T7SSb architecture remain obscure. Here, we provide hints on the organization of T7SSb in B. subtilis and a high-resolution structure of its central pseudokinase subunit, opening new perspectives for the understanding of the T7SSb secretion mechanism by using B. subtilis as an amenable bacterial model.


Assuntos
Sistemas de Secreção Tipo VII , Sistemas de Secreção Tipo VII/metabolismo , Bacillus subtilis/genética , Bacillus subtilis/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Antibacterianos/metabolismo
15.
Microbiol Resour Announc ; 11(8): e0050522, 2022 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-35852335

RESUMO

We present the complete genome sequence of Bradyrhizobium sp. strain C-145, one of the most widely used nitrogen-fixing rhizobacteria for inoculating peanut crops in Argentina. The genome consists of 9.53 Mbp in a single circular chromosome and was determined using a hybrid long- and short-read assembly approach.

16.
Pract Lab Med ; 31: e00297, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35880117

RESUMO

Background and aims: GEM Premier ChemSTAT is a new point-of-care system providing rapid creatinine, BUN and tCO2 measurements together with electrolytes, metabolites, hematocrit, pH and pCO2 from a single whole blood specimen in acute care settings such as emergency departments and intensive care units. Accurate measurements of whole blood creatinine can aid in the diagnosis and treatment of renal diseases. Materials and methods: Heparinized whole blood samples from different clinical locations were evaluated on the GEM Premier ChemSTAT and results compared to plasma from the same samples on the Beckman AU5800 or whole blood on the GEM Premier 4000. Precision studies were conducted with whole blood and quality control material. Results: ChemSTAT correlated well with plasma samples on the AU5800 (regression slopes (S): 0.957-1.159, correlation coefficients (r)≥0.952) and with whole blood specimens on the GEM Premier 4000 (S: 0.9646-1.124, r ≥ 0.974). The repeatability was 0.1%-3.1% and QC precision were within lab and manufacturers' specifications. Conclusion: ChemSTAT demonstrated strong correlation to the comparative methods and excellent precision. Combining with its continuous quality management, ChemSTAT is suitable for acute care settings to provide rapid, reliable results, which could minimize time-to-treatment and improve patient outcome.

17.
Biochim Biophys Acta Proteins Proteom ; 1870(2): 140745, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-34906734

RESUMO

Bacteriophage endolysins are crucial for progeny release at the end of the lytic cycle. Mycobacteriophage's genomes carry a lysin A essential gene, whose product cleaves the peptidoglycan (PG) layer and a lysin B, coding for an esterase, that cleaves the linkage between the mycolic acids and the arabinogalactan-PG complex. Lysin A mycobacteriophage proteins are highly modular and in gp29 (LysA) of phage TM4 three distinctive domains were identified. By bioinformatics analysis the central module was previously found to be similar to an amidase-2 domain family with an N-acetylmuramoyl -L-alanine amidase activity. We demonstrated experimentally that purified LysA is able to lyse a suspension of Micrococcus lysodeikticus and can promote cell lysis when expressed in E. coli and Mycobacterium smegmatis. After incubation of LysA with MDP (Muramyl dipeptide, N-acetyl-muramyl-L-alanyl-D-isoglutamine) we detected the presence of N-acetylmuramic acid (NAcMur) and L-Ala- D- isoGlutamine (L-Ala-D-isoGln) corroborating the proposed muramidase activity of this enzyme. This protein was stabilized at acidic pH in the presence of Zn consistent with the increase of the enzymatic activity under these conditions. By homology modeling, we predicted that the Zn ion is coordinated by His 226, His 335, and Asp 347 and we also identified the amino acid Glu 290 as the catalytic residue. LysA activity was completely abolished in derived mutants on these key residues, suggesting that the PG hydrolysis solely relies on the central domain of the protein.


Assuntos
Endopeptidases/metabolismo , Micobacteriófagos/metabolismo , N-Acetil-Muramil-L-Alanina Amidase/metabolismo , Peptidoglicano/metabolismo , Proteínas Virais/metabolismo , Biologia Computacional/métodos , Endopeptidases/química , Escherichia coli/metabolismo , Galactanos , Hidrólise , Espectrometria de Massas/métodos , Micrococcus/metabolismo , Ácidos Murâmicos/metabolismo , Mycobacterium smegmatis/metabolismo , Proteínas Virais/química
18.
Sci Rep ; 11(1): 24036, 2021 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-34912011

RESUMO

Throughout the Pleistocene, early humans and carnivores frequented caves and large rock-shelters, usually generating bone accumulations. The well-preserved late Early Pleistocene sedimentary sequence at Cueva Negra del Estrecho del Río Quípar (CNERQ) has provided substantial evidence concerning the behavioural and adaptive skills of early humans in Western Europe, such as butchery practices, lithic technology or tending fire, whilst also bearing witness to the bone-altering activities of carnivores. Recent fieldwork has allowed the re-examination of the spatial and taphonomical nature of the macrofaunal assemblage from the upper layers of Complex 2. These layers are somewhat different from most of the underlying sequence, in showing quite a high representation of cranial and post-cranial bones of large mammals, including several Megaloceros carthaginiensis antlers. The presence of Crocuta sp. at Cueva Negra represents one of the earliest instances of this genus in Western Eurasia. Identification of several juvenile Crocuta sp. remains alongside coprolites and bones with carnivore damage, indicates sporadical hyaenid denning activity. Furthermore, the presence of bones with percussion and cut-marks near to several hammerstones suggests a clear albeit limited anthropogenic input. We interpret the available taphonomical and spatial evidence from these layers as reflecting a multi-patterned palimpsest, likely representing the non-simultaneous and short-lived co-existence of hyaenas, humans, and other small carnivores in the Cueva Negra palaeolandscape during the final phase of sedimentation preserved at the site.

19.
Gerokomos (Madr., Ed. impr.) ; 32(2): 122-130, jun. 2021. tab, ilus
Artigo em Espanhol | IBECS | ID: ibc-218620

RESUMO

Introducción: La atención a las lesiones cutáneas relacionadas con la dependencia, las úlceras de extremidad inferior y otro tipo de heridas superficiales representa un importante reto para los profesionales de la salud. Estos tipos de lesiones, cuando son superficiales, requieren de un abordaje específico por el elevado riesgo de que se conviertan en heridas más profundas, que pueden afectar a la salud y a la calidad de vida de quienes las padecen, y pueden requerir de tratamientos más complejos y costosos. Los ácidos grasos hiperoxigenados (AGHO) están considerados hoy en día como una de las medidas más importantes para la prevención de este tipo de lesiones. La familia Mepentol® (Mepentol, Mepentol Leche y Mepentol AGHO) son los únicos AGHO clasificados como productos sanitarios con Marca CE clase IIb y, por ello, pueden utilizarse también en el tratamiento de lesiones superficiales. La coexistencia de piel íntegra, pero agredida, y lesiones superficiales es una situación muy habitual en la práctica clínica. Pacientes, material y métodos: Se presentan los resultados de una serie de casos clínicos en los que se ha utilizado Mepentol® y Mepentol® Leche para el tratamiento de lesiones crónicas superficiales. Se incluyeron pacientes con heridas crónicas superficiales de diferente etiología que no fuesen alérgicos a ninguno de los componentes de dichos productos y que dieron su consentimiento a participar en la evaluación. Las lesiones fueron incluidas en la evaluación hasta conseguir su cicatrización o resolución. Resultados: La serie de casos clínicos comprende 54 pacientes con 73 lesiones crónicas superficiales: 45 úlceras de la extremidad inferior, 10 lesiones cutáneas relacionadas con la dependencia, 5 lesiones cutáneas relacionadas con la insuficiencia venosa y 13 lesiones de otra tipología. La antigüedad mediana de las lesiones era de 39 días (AU)


Introduction: The care of dependency-related skin injuries, lower limb ulcers and other types of superficial wounds, represents a major challenge for healthcare professionals. These types of injuries, when superficial, require a specific approach because of the high risk of developing into deeper wounds, which can affect the health and quality of life of sufferers, and may require more complex and costly treatments. Hyperoxygenated fatty acids (HOFA) are nowadays considered as one of the most important measures for the prevention of these types of injuries. The Mepentol® range of products (Mepentol®, Mepentol® Leche and Mepentol AGHO) are the only HOFA CE certifies medical devices IIb and can therefore also be used in the treatment of superficial lesions. The coexistence of integrated, but damaged skin, and superficial lesions is a very common situation in clinical practice. Patients, material and methods: The results of a clinical case series in which Mepentol® and Mepentol® Leche have been used for the treatment of superficial chronic wounds are presented. Patients with superficial chronic wounds of different etiology who were not allergic to any of the components of these products and who consented to participate in the evaluation were included. Lesions were included in the evaluation until healing or resolution was achieved. Results: The case series comprised 54 patients with 73 superficial chronic lesions: 45 lower extremity ulcers, 10 skin lesions related to dependence, 5 skin lesions related to venous insufficiency and 13 lesions of other types. The median age of the lesions was 39 days. 45 lesions (61.6%) were treated with Mepentol® and 28 (38.4%) with Mepentol® Leche. The 73 lesions included in the study healed in a median of 23 days. There were no complications or episodes of local infection (AU)


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Ácidos Graxos/uso terapêutico , Ferimentos e Lesões/tratamento farmacológico , Resultado do Tratamento , Doença Crônica
20.
Nat Commun ; 11(1): 1641, 2020 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-32242019

RESUMO

The mechanisms of Z-ring assembly and regulation in bacteria are poorly understood, particularly in non-model organisms. Actinobacteria, a large bacterial phylum that includes the pathogen Mycobacterium tuberculosis, lack the canonical FtsZ-membrane anchors and Z-ring regulators described for E. coli. Here we investigate the physiological function of Corynebacterium glutamicum SepF, the only cell division-associated protein from Actinobacteria known to interact with the conserved C-terminal tail of FtsZ. We show an essential interdependence of FtsZ and SepF for formation of a functional Z-ring in C. glutamicum. The crystal structure of the SepF-FtsZ complex reveals a hydrophobic FtsZ-binding pocket, which defines the SepF homodimer as the functional unit, and suggests a reversible oligomerization interface. FtsZ filaments and lipid membranes have opposing effects on SepF polymerization, indicating that SepF has multiple roles at the cell division site, involving FtsZ bundling, Z-ring tethering and membrane reshaping activities that are needed for proper Z-ring assembly and function.


Assuntos
Proteínas de Bactérias/metabolismo , Corynebacterium glutamicum/citologia , Corynebacterium glutamicum/metabolismo , Proteínas do Citoesqueleto/metabolismo , Sequência de Aminoácidos , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Divisão Celular , Corynebacterium glutamicum/química , Corynebacterium glutamicum/genética , Proteínas do Citoesqueleto/química , Proteínas do Citoesqueleto/genética , Dimerização , Regulação Bacteriana da Expressão Gênica , Ligação Proteica , Alinhamento de Sequência
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