m6A landscape is more pervasive when Trypanosoma brucei exits the cell cycle.

N6-methyladenosine (m6A) is a mRNA modification with important roles in gene expression. In African trypanosomes, this post-transcriptional modification is detected in hundreds of transcripts and it affects the stability of the variant surface glycoprotein (VSG) transcript in the proliferating blood stream form. However, how the m6A landscape varies across the life cycle remains poorly defined. Using full-length, non-fragmented RNA, we immunoprecipitated and sequenced m6A-modified transcripts across three life cycle stages of Trypanosoma brucei - slender (proliferative), stumpy (quiescent), and procyclic forms (proliferative). We found that 1037 transcripts are methylated in at least one of these three life cycle stages. While 21% of methylated transcripts are common in the three stages of the life cycle, globally each stage has a distinct methylome. Interestingly, 47% of methylated transcripts are detected in the quiescent stumpy form only, suggesting a critical role for m6A when parasites exit the cell cycle and prepare for transmission by the Tsetse fly. In this stage, we found that a significant proportion of methylated transcripts encodes for proteins involved in RNA metabolism, which is consistent with their reduced transcription and translation. Moreover, we found that not all major surface proteins are regulated by m6A, as procyclins are not methylated, and that, within the VSG repertoire, not all VSG transcripts are demethylated upon parasite differentiation to procyclic form. This study reveals that the m6A regulatory landscape is specific to each life cycle stage, becoming more pervasive as T. brucei exits the cell cycle.

The lymphatic system favours survival of a unique T. brucei population.

Trypanosoma brucei colonise and multiply in the blood vasculature, as well as in various organs of the host's body. Lymph nodes have been previously shown to harbour large numbers of parasites, and the lymphatic system has been proposed as a key site that allows T. brucei distribution through, and colonization of the mammalian body. However, visualization of host-pathogen interactions in the lymphatic system has never captured dynamic events with high spatial and temporal resolution throughout infection. In our work, we used a mixture of tools including intravital microscopy and ex vivo imaging to study T. brucei distribution in 20 sets of lymph nodes. We demonstrate that lymph node colonization by T. brucei is different across lymph node sets, with the most heavily colonised being the draining lymph nodes of main tissue reservoirs: the gonadal white adipose tissue and pancreas. Moreover, we show that the lymphatic vasculature is a pivotal site for parasite dispersal, and altering this colonization by blocking LYVE-1 is detrimental for parasite survival. Additionally, parasites within the lymphatic vasculature have unique morphological and behavioural characteristics, different to those found in the blood, demonstrating that across both types of vasculature, these environments are physically separated. Finally, we demonstrate that the lymph nodes and the lymphatic vasculature undergo significant alterations during T. brucei infection, resulting in oedema throughout the host's body.

Adipocyte lipolysis protects mice against Trypanosoma brucei infection.

Trypanosoma brucei causes African trypanosomiasis, colonizing adipose tissue and inducing weight loss. Here we investigated the molecular mechanisms responsible for adipose mass loss and its impact on disease pathology. We found that lipolysis is activated early in infection. Mice lacking B and T lymphocytes fail to upregulate adipocyte lipolysis, resulting in higher fat mass retention. Genetic ablation of the rate-limiting adipose triglyceride lipase specifically from adipocytes (AdipoqCre/+-Atglfl/fl) prevented the stimulation of adipocyte lipolysis during infection, reducing fat mass loss. Surprisingly, these mice succumbed earlier and presented a higher parasite burden in the gonadal adipose tissue, indicating that host lipolysis limits parasite growth. Consistently, free fatty acids comparable with those of adipose interstitial fluid induced loss of parasite viability. Adipocyte lipolysis emerges as a mechanism controlling local parasite burden and affecting the loss of fat mass in African trypanosomiasis.

Principais manifestações clínicas oftalmológicas prevalentes em pacientes acometidos por fraturas orbitárias: revisão integrativa de literatura / The main ophthalmological clinical manifestations prevalent in patients affected by orbital fractures: an integrative literature review

RESUMO Um em cada quatro pacientes acometidos por trauma maxilofacial terão concomitantemente fraturas da órbita e lesão ocular. Por isso, uma avaliação oftalmológica minuciosa é recomendada para todos os pacientes que sofrem um trauma de face. Alguns exames oftalmológicos logo após o trauma podem ser decisivos para a preservação da acuidade visual. Sujeitos com achados de exame físico de acuidade visual deficitárias, defeito pupilar aferente e imagens radiográficas com alta profundidade da fratura da órbita estão em maior risco de perda de visão e justificam preocupação específica para avaliação de lesão ocular. O objetivo deste estudo foi reunir as manifestações clínicas oftalmológicas prevalentes em pacientes acometidos por fraturas orbitárias, com o intuito de adquirir melhor perspectiva e entendimento acerca das consequências que a patologia traz ao indivíduo, no que tange à oftalmologia e aos tratamentos mais adequados. Trata-se de estudo de revisão integrativa, utilizando as bases de dados Pubmed®/Medline®, SciELO, Biblioteca Virtual em Saúde e Lilacs, com um vocabulário controlado segundo a estratégia de busca em cada uma das bases de dados bibliográficas, por meio dos termos "ophthalmologic complications", "prevalence", "orbital fracture", em estudos publicados de 2013 a 2023. A qualidade dos artigos foi avaliada usando o Study Quality Assessment Tool from the Department of Health and Human Services. Foram encontradas 46 referências, sendo 20 no Pubmed®/Medline®, 17 na SciELO, 9 na Biblioteca Virtual em Saúde e nenhuma na Lilacs. Após excluir referências duplicadas, foram selecionadas 44 referências para avaliação de elegibilidade. Após leitura dos títulos e resumos (n=44), 36 estudos foram excluídos pelas seguintes razões: artigos que não respondiam a nossa pergunta científica (n=11) e publicação superior a 10 anos (n=25). Identificaram-se, nos oito artigos selecionados, o objetivo do estudo, a população estudada o nível de evidência. Os oito estudos tiveram como objetivo analisar traumas orbitais com alterações funcionais significativas oculares e visuais pelo prejuízo ao tecido ósseo, nervoso, vascular e até parenquimatoso cerebral na região do assoalho e paredes de cavidades orbital. Dentre as manifestações clínicas oftalmológicas mais importantes, listam-se manifestação de enoftalmia, diplopia, hifema traumático, hemorragia retiniana, amaurose, quemose, neuropatia óptica traumática e hematoma retrobulbar. Considerando os oito estudos analisados, verificou-se a presença unânime de manifestações clínicas oftalmológicas na totalidade dos pacientes acometidos, sendo predominantes a baixa acuidade visual e o hifema. No que tange aos achados de menor prevalência, ao equipará-los às manifestações clínicas oftalmológicas mais encontradas, verifica-se que possuem como fator principal o estado transitório, concluindo-se que, mesmo com toda a gravidade do quadro de fratura orbitária, sua tendência é não deixar sequelas permanentes em grande partes dos casos, ainda que não seja nítida a relação estabelecida pela ausência de sequelas permanentes, especulando-se que essa ausência se deve à identificação do quadro e à intervenção adequada em tempo hábil.

ABSTRACT One in four patients affected by maxillofacial trauma will have concomitant orbital fractures and ocular injuries; therefore, an ophthalmological evaluation is recommended for all patients who have been affected by facial trauma. Some ophthalmological exams soon after the trauma can be decisive for the preservation of visual acuity. Patients with physical examination findings of poor visual acuity, afferent pupillary defect, radiographic images with high depth of orbital fracture, are at greater risk of vision loss and specific concern for evaluation of ocular injury. The objective of this study was to gather the prevalent ophthalmologic clinical manifestations in patients affected by orbital fractures, to achieve a better perspective and understanding about the consequences that the pathology brings to the individual regarding ophthalmology and the most appropriate treatments. This is an integrative review study, using the Pubmed®/Medline®, SciELO, Virtual Health Library and Lilacs databases, with a controlled vocabulary according to the search strategy in each of the bibliographic databases, using the terms "ophthalmologic complications", "prevalence", "orbital fracture", in studies published from 2013 to 2023. The quality of the articles was assessed using the Study Quality Assessment Tool from the Department of Health and Human Services. A total of 46 references were found, 20 in Pubmed®/Medline®, 17 in SciELO, 9 in the Virtual Health Library and none in Lilacs. After excluding duplicate references, 44 references were selected for eligibility assessment. After reading the titles and abstracts (n=44), 36 studies were excluded for the following reasons: articles that did not answer our scientific question (n=11) and publication over 10 years (n=25). In the eight selected articles, the objective of the study, the population studied, and the level of evidence were identified. The eight studies aimed to analyze orbital trauma with significant ocular and visual functional changes due to damage to bone, nerve, vascular, and even brain parenchymal tissue in the region of the floor and walls of orbital cavities. Among the most important ophthalmologic clinical manifestations, there are enophthalmos, diplopia, traumatic hyphema, retinal hemorrhage, amaurosis, chemosis, traumatic optic neuropathy and retrobulbar hematoma. Considering the eight studies analyzed, there was a unanimous presence of ophthalmological clinical manifestations in all affected patients, with low visual acuity and hyphema being predominant. Regarding the findings of lower prevalence, when equating them to the most common ophthalmologic clinical manifestations, they have as main factor the transient state, which can be concluded that, even with all the severity of the orbital fracture, its tendency is not to leave permanent sequelae in most cases, although the relationship established by the absence of permanent sequelae is not clear, speculating that this absence is due to the identification of the condition and the appropriate intervention in a timely manner.

SARS-CoV-2 variant Delta rapidly displaced variant Alpha in the United States and led to higher viral loads.

We report on the sequencing of 74,348 SARS-CoV-2 positive samples collected across the United States and show that the Delta variant, first detected in the United States in March 2021, made up the majority of SARS-CoV-2 infections by July 1, 2021 and accounted for >99.9% of the infections by September 2021. Not only did Delta displace variant Alpha, which was the dominant variant at the time, it also displaced the Gamma, Iota, and Mu variants. Through an analysis of quantification cycle (Cq) values, we demonstrate that Delta infections tend to have a 1.7× higher viral load compared to Alpha infections (a decrease of 0.8 Cq) on average. Our results are consistent with the hypothesis that the increased transmissibility of the Delta variant could be due to the ability of the Delta variant to establish a higher viral load earlier in the infection as compared to the Alpha variant.

Thermochemical Liquefaction as a Cleaner and Efficient Route for Valuing Pinewood Residues from Forest Fires.

Biomass thermochemical liquefaction is a chemical process with multifunctional bio-oil as its main product. Under this process, the complex structure of lignocellulosic components can be hydrolysed into smaller molecules at atmospheric pressure. This work demonstrates that the liquefaction of burned pinewood from forest fires delivers similar conversion rates into bio-oil as non-burned wood does. The bio-oils from four burned biomass fractions (heartwood, sapwood, branches, and bark) showed lower moisture content and higher HHV (ranging between 32.96 and 35.85 MJ/kg) than the initial biomasses. The increased HHV resulted from the loss of oxygen, whereas the carbon and hydrogen mass fractions increased. The highest conversion of bark and heartwood was achieved after 60 min of liquefaction. Sapwood, pinewood, and branches reached a slightly higher conversion, with yields about 8% greater, but with longer liquefaction time resulting in higher energy consumption. Additionally, the van Krevelen diagram indicated that the produced bio-oils were closer and chemically more compatible (in terms of hydrogen and oxygen content) to the hydrocarbon fuels than the initial biomass counterparts. In addition, bio-oil from burned pinewood was shown to be a viable alternative biofuel for heavy industrial applications. Overall, biomass from forest fires can be used for the liquefaction process without compromising its efficiency and performance. By doing so, it recovers part of the lost value caused by wildfires, mitigating their negative effects.

Trypanosoma brucei triggers a broad immune response in the adipose tissue.

Adipose tissue is one of the major reservoirs of Trypanosoma brucei parasites, the causative agent of sleeping sickness, a fatal disease in humans. In mice, the gonadal adipose tissue (AT) typically harbors 2-5 million parasites, while most solid organs show 10 to 100-fold fewer parasites. In this study, we tested whether the AT environment responds immunologically to the presence of the parasite. Transcriptome analysis of T. brucei infected adipose tissue revealed that most upregulated host genes are involved in inflammation and immune cell functions. Histochemistry and flow cytometry confirmed an increasingly higher number of infiltrated macrophages, neutrophils and CD4+ and CD8+ T lymphocytes upon infection. A large proportion of these lymphocytes effectively produce the type 1 effector cytokines, IFN-γ and TNF-α. Additionally, the adipose tissue showed accumulation of antigen-specific IgM and IgG antibodies as infection progressed. Mice lacking T and/or B cells (Rag2-/-, Jht-/-), or the signature cytokine (Ifng-/-) displayed a higher parasite load both in circulation and in the AT, demonstrating the key role of the adaptive immune system in both compartments. Interestingly, infections of C3-/- mice showed that while complement system is dispensable to control parasite load in the blood, it is necessary in the AT and other solid tissues. We conclude that T. brucei infection triggers a broad and robust immune response in the AT, which requires the complement system to locally reduce parasite burden.

Environmental conditions dictate differential evolution of vancomycin resistance in Staphylococcus aureus.

While microbiological resistance to vancomycin in Staphylococcus aureus is rare, clinical vancomycin treatment failures are common, and methicillin-resistant S. aureus (MRSA) strains isolated from patients after prolonged vancomycin treatment failure remain susceptible. Adaptive laboratory evolution was utilized to uncover mutational mechanisms associated with MRSA vancomycin resistance in a physiological medium as well as a bacteriological medium used in clinical susceptibility testing. Sequencing of resistant clones revealed shared and media-specific mutational outcomes, with an overlap in cell wall regulons (walKRyycHI, vraSRT). Evolved strains displayed similar properties to resistant clinical isolates in their genetic and phenotypic traits. Importantly, resistant phenotypes that developed in physiological media did not translate into resistance in bacteriological media. Further, a bacteriological media-specific mechanism for vancomycin resistance associated with a mutated mprF was confirmed. This study bridges the gap between the understanding of clinical and microbiological vancomycin resistance in S. aureus and expands the number of allelic variants (18 ± 4 mutations for the top 5 mutated genes) that result in vancomycin resistance phenotypes.

Innovative Approaches to Assess Intermediate Cardiovascular Risk Subjects: A Review From Clinical to Metabolomics Strategies.

Current risk stratification strategies for coronary artery disease (CAD) have low predictive value in asymptomatic subjects classified as intermediate cardiovascular risk. This is relevant because not all coronary events occur in individuals with traditional multiple risk factors. Most importantly, the first manifestation of the disease may be either sudden cardiac death or acute coronary syndrome, after rupture and thrombosis of an unstable non-obstructive atherosclerotic plaque, which was previously silent. The inaccurate stratification using the current models may ultimately subject the individual to excessive or insufficient preventive therapies. A breakthrough in the comprehension of the molecular mechanisms governing the atherosclerosis pathology has driven many researches toward the necessity for a better risk stratification. In this Review, we discuss how metabolomics screening integrated with traditional risk assessments becomes a powerful approach to improve non-invasive CAD subclinical diagnostics. In addition, this Review highlights the findings of metabolomics studies performed by two relevant analytical platforms in current use-mass spectrometry (MS) hyphenated to separation techniques and nuclear magnetic resonance spectroscopy (NMR) -and evaluates critically the challenges for further clinical implementation of metabolomics data. We also discuss the modern understanding of the pathophysiology of atherosclerosis and the limitations of traditional analytical methods. Our aim is to show how discriminant metabolites originated from metabolomics approaches may become promising candidate molecules to aid intermediate risk patient stratification for cardiovascular events and how these tools could successfully meet the demands to translate cardiovascular metabolic biomarkers into clinical settings.

Polyreactive Antibodies Bridge Immunity Particles to Pathogen.

Humans are protected from most African trypanosomes via high-density lipoproteins, known as trypanosome lytic factor (TLF). In humans, IgM antibodies are found associated with TLF. The recent work by Verdi et al. studied the origin of these antibodies and their binding partners, suggesting a new model for TLF uptake.

Revealing 29 sets of independently modulated genes in Staphylococcus aureus, their regulators, and role in key physiological response.

The ability of Staphylococcus aureus to infect many different tissue sites is enabled, in part, by its transcriptional regulatory network (TRN) that coordinates its gene expression to respond to different environments. We elucidated the organization and activity of this TRN by applying independent component analysis to a compendium of 108 RNA-sequencing expression profiles from two S. aureus clinical strains (TCH1516 and LAC). ICA decomposed the S. aureus transcriptome into 29 independently modulated sets of genes (i-modulons) that revealed: 1) High confidence associations between 21 i-modulons and known regulators; 2) an association between an i-modulon and σS, whose regulatory role was previously undefined; 3) the regulatory organization of 65 virulence factors in the form of three i-modulons associated with AgrR, SaeR, and Vim-3; 4) the roles of three key transcription factors (CodY, Fur, and CcpA) in coordinating the metabolic and regulatory networks; and 5) a low-dimensional representation, involving the function of few transcription factors of changes in gene expression between two laboratory media (RPMI, cation adjust Mueller Hinton broth) and two physiological media (blood and serum). This representation of the TRN covers 842 genes representing 76% of the variance in gene expression that provides a quantitative reconstruction of transcriptional modules in S. aureus, and a platform enabling its full elucidation.

Mycobacterium tuberculosis associated with severe tuberculosis evades cytosolic surveillance systems and modulates IL-1ß production.

Genetic diversity of Mycobacterium tuberculosis affects immune responses and clinical outcomes of tuberculosis (TB). However, how bacterial diversity orchestrates immune responses to direct distinct TB severities is unknown. Here we study 681 patients with pulmonary TB and show that M. tuberculosis isolates from cases with mild disease consistently induce robust cytokine responses in macrophages across multiple donors. By contrast, bacteria from patients with severe TB do not do so. Secretion of IL-1ß is a good surrogate of the differences observed, and thus to classify strains as probable drivers of different TB severities. Furthermore, we demonstrate that M. tuberculosis isolates that induce low levels of IL-1ß production can evade macrophage cytosolic surveillance systems, including cGAS and the inflammasome. Isolates exhibiting this evasion strategy carry candidate mutations, generating sigA recognition boxes or affecting components of the ESX-1 secretion system. Therefore, we provide evidence that M. tuberculosis strains manipulate host-pathogen interactions to drive variable TB severities.

Genetic Determinants Enabling Medium-Dependent Adaptation to Nafcillin in Methicillin-Resistant Staphylococcus aureus.

Antimicrobial susceptibility testing standards driving clinical decision-making have centered around the use of cation-adjusted Mueller-Hinton broth (CA-MHB) as the medium with the notion of supporting bacterial growth, without consideration of recapitulating the in vivo environment. However, it is increasingly recognized that various medium conditions have tremendous influence on antimicrobial activity, which in turn may have major implications on the ability of in vitro susceptibility assays to predict antibiotic activity in vivo. To elucidate differential growth optimization and antibiotic resistance mechanisms, adaptive laboratory evolution was performed in the presence or absence of the antibiotic nafcillin with methicillin-resistant Staphylococcus aureus (MRSA) TCH1516 in either (i) CA-MHB, a traditional bacteriological nutritionally rich medium, or (ii) Roswell Park Memorial Institute (RPMI), a medium more reflective of the in vivo host environment. Medium adaptation analysis showed an increase in growth rate in RPMI, but not CA-MHB, with mutations in apt, adenine phosphoribosyltransferase, and the manganese transporter subunit, mntA, occurring reproducibly in parallel replicate evolutions. The medium-adapted strains showed no virulence attenuation. Continuous exposure of medium-adapted strains to increasing concentrations of nafcillin led to medium-specific evolutionary strategies. Key reproducibly occurring mutations were specific for nafcillin adaptation in each medium type and did not confer resistance in the other medium environment. Only the vraRST operon, a regulator of membrane- and cell wall-related genes, showed mutations in both CA-MHB- and RPMI-evolved strains. Collectively, these results demonstrate the medium-specific genetic adaptive responses of MRSA and establish adaptive laboratory evolution as a platform to study clinically relevant resistance mechanisms.IMPORTANCE The ability of pathogens such as Staphylococcus aureus to evolve resistance to antibiotics used in the treatment of infections has been an important concern in the last decades. Resistant acquisition usually translates into treatment failure and puts patients at risk of unfavorable outcomes. Furthermore, the laboratory testing of antibiotic resistance does not account for the different environment the bacteria experiences within the human body, leading to results that do not translate into the clinic. In this study, we forced methicillin-resistant S. aureus to develop nafcillin resistance in two different environments, a laboratory environment and a physiologically more relevant environment. This allowed us to identify genetic changes that led to nafcillin resistance under both conditions. We concluded that not only does the environment dictate the evolutionary strategy of S. aureus to nafcillin but also that the evolutionary strategy is specific to that given environment.

GNSS/LiDAR-Based Navigation of an Aerial Robot in Sparse Forests.

Autonomous navigation of unmanned vehicles in forests is a challenging task. In such environments, due to the canopies of the trees, information from Global Navigation Satellite Systems (GNSS) can be degraded or even unavailable. Also, because of the large number of obstacles, a previous detailed map of the environment is not practical. In this paper, we solve the complete navigation problem of an aerial robot in a sparse forest, where there is enough space for the flight and the GNSS signals can be sporadically detected. For localization, we propose a state estimator that merges information from GNSS, Attitude and Heading Reference Systems (AHRS), and odometry based on Light Detection and Ranging (LiDAR) sensors. In our LiDAR-based odometry solution, the trunks of the trees are used in a feature-based scan matching algorithm to estimate the relative movement of the vehicle. Our method employs a robust adaptive fusion algorithm based on the unscented Kalman filter. For motion control, we adopt a strategy that integrates a vector field, used to impose the main direction of the movement for the robot, with an optimal probabilistic planner, which is responsible for obstacle avoidance. Experiments with a quadrotor equipped with a planar LiDAR in an actual forest environment is used to illustrate the effectiveness of our approach.

Strain-Specific Metabolic Requirements Revealed by a Defined Minimal Medium for Systems Analyses of Staphylococcus aureus.

Staphylococcus aureus is a Gram-positive pathogenic bacterium that colonizes an estimated one-third of the human population and can cause a wide spectrum of disease, ranging from superficial skin infections to life-threatening sepsis. The adaptive mechanisms that contribute to the success of this pathogen remain obscure partially due to a lack of knowledge of its metabolic requirements. Systems biology approaches can be extremely useful in predicting and interpreting metabolic phenotypes; however, such approaches rely on a chemically defined minimal medium as a basis to investigate the requirements of the cell. In this study, a chemically defined minimal medium formulation, termed synthetic minimal medium (SMM), was investigated and validated to support growth of three S. aureus strains: LAC and TCH1516 (USA300 lineage), as well as D592 (USA100 lineage). The formulated SMM was used in an adaptive laboratory evolution experiment to probe the various mutational trajectories of all three strains leading to optimized growth capabilities. The evolved strains were phenotypically characterized for their growth rate and antimicrobial susceptibility. Strains were also resequenced to examine the genetic basis for observed changes in phenotype and to design follow-up metabolite supplementation assays. Our results reveal evolutionary trajectories that arose from strain-specific metabolic requirements. SMM and the evolved strains can also serve as important tools to study antibiotic resistance phenotypes of S. aureusIMPORTANCE As researchers try to understand and combat the development of antibiotic resistance in pathogens, there is a growing need to thoroughly understand the physiology and metabolism of the microbes. Staphylococcus aureus is a threatening pathogen with increased antibiotic resistance and well-studied virulence mechanisms. However, the adaptive mechanisms used by this pathogen to survive environmental stresses remain unclear, mostly due to the lack of information about its metabolic requirements. Defining the minimal metabolic requirements for S. aureus growth is a first step toward unraveling the mechanisms by which it adapts to metabolic stresses. Here, we present the development of a chemically defined minimal medium supporting growth of three S. aureus strains, and we reveal key genetic mutations contributing to improved growth in minimal medium.

Systems Biology and Pangenome of Salmonella O-Antigens.

O-antigens are glycopolymers in lipopolysaccharides expressed on the cell surface of Gram-negative bacteria. Variability in the O-antigen structure constitutes the basis for the establishment of the serotyping schema. We pursued a two-pronged approach to define the basis for O-antigen structural diversity. First, we developed a bottom-up systems biology approach to O-antigen metabolism by building a reconstruction of Salmonella O-antigen biosynthesis and used it to (i) update 410 existing Salmonella strain-specific metabolic models, (ii) predict a strain's serogroup and its O-antigen glycan synthesis capability (yielding 98% agreement with experimental data), and (iii) extend our workflow to more than 1,400 Gram-negative strains. Second, we used a top-down pangenome analysis to elucidate the genetic basis for intraserogroup O-antigen structural variations. We assembled a database of O-antigen gene islands from over 11,000 sequenced Salmonella strains, revealing (i) that gene duplication, pseudogene formation, gene deletion, and bacteriophage insertion elements occur ubiquitously across serogroups; (ii) novel serotypes in the group O:4 B2 variant, as well as an additional genotype variant for group O:4, and (iii) two novel O-antigen gene islands in understudied subspecies. We thus comprehensively defined the genetic basis for O-antigen diversity.IMPORTANCE Lipopolysaccharides are a major component of the outer membrane in Gram-negative bacteria. They are composed of a conserved lipid structure that is embedded in the outer leaflet of the outer membrane and a polysaccharide known as the O-antigen. O-antigens are highly variable in structure across strains of a species and are crucial to a bacterium's interactions with its environment. They constitute the first line of defense against both the immune system and bacteriophage infections and have been shown to mediate antimicrobial resistance. The significance of our research is in identifying the metabolic and genetic differences within and across O-antigen groups in Salmonella strains. Our effort constitutes a first step toward characterizing the O-antigen metabolic network across Gram-negative organisms and a comprehensive overview of genetic variations in Salmonella.

Photopiperazines A-D, Photosensitive Interconverting Diketopiperazines with Significant and Selective Activity against U87 Glioblastoma Cells, from a Rare, Marine-Derived Actinomycete of the Family Streptomycetaceae.

Photopiperazines A-D (1-4), unsaturated diketopiperazine derivatives, were isolated from the culture broth of a rare, marine-derived actinomycete bacterium, strain AJS-327. This strain shows very poor 16S rRNA sequence similarity to other members of the actinomycete family Streptomycetaceae, indicating it is likely a new lineage within this group. The structures of the photopiperazines were defined by analysis of HR-ESI-TOF-MS spectra in conjunction with the interpretation of 1D and 2D NMR data. The photopiperazines are sensitive to light, causing interconversion among the four olefin geometrical isomers, which made purification of each isomer challenging. The photopiperazines are highly cytotoxic metabolites that show selective toxicity toward U87 glioblastoma and SKOV3 ovarian cancer cell lines.

Open anterograde anatomic radical retropubic prostatectomy technique: description of the first fiftyfive procedures.

INTRODUCTION: Robotic-assisted radical prostatectomy is the leading surgical technique and was discussed in Pasadena Consensus Panel (1). The goal of this study is to present the results of the first fifty-five patients submitted to Anterograde Anatomic Radical Retropubic Prostatectomy technique (R2PA2), without adding complexity or cost. MATERIALS AND METHODS: Fifty-five eligible men with localized prostate cancer underwent R2PA2 from January, 2016 to December, 2017. The technique was previously described (2): the main surgical steps were anterograde dissection, ligation of the dorsal vascular complex without dividing, preservation of the bladder neck, nerve sparing, preservation of Denonvilliers' fascia and confection of the running suture anastomosis. All patients were operated on by second-year residents. RESULTS: All procedures were completed as planned, but one converted to retrograde prostatectomy (mean duration, 163.40 minutes; hospital stay, 4 days with 4.20 days of drainage; indwelling vesical catheterization of 9.80 days). Positive surgical margin was found in six T2 staging patient (10.90%) and five T3 (9.10%). Biochemical PSA recurrence occurred in three patients (5.50%). Twenty-four (43.60%) were continent immediately after indwelling catheter removal, seventeen (30.90%) did not wear a pad at one postoperative month while eighteen (30%) used only one safety pad. Five minor complications occurred. CONCLUSION: We were able to perform R2PA2 allowing men who do not have access to this new technology to be operated on with the same technique used in robotic surgery. This method was reproducible by low-volume prostate cancer surgeons; help inexperienced surgeons to develop skills valuable to future training with robotic techniques. ACKNOWLEDGEMENTS This work was supported by the FAPERJ - Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro. Secretaria de Estado de Ciência, Tecnologia e Inovação do Governo do Estado do Rio de Janeiro, Brazil, and Pedro Ernesto University Hospital of the State University of Rio de Janeiro, Brazil. Available at: http://www.intbrazjurol.com.br/video-section/20180421_Carrerette_et_al.