Ribonucleotide reductase inhibition improves the symptoms of a Caenorhabditis elegans model of Alzheimer's disease.

Alzheimer's disease is the main cause of aging-associated dementia, for which there is no effective treatment. In this work, we reanalyze the information of a previous genome wide association study, using a new pipeline design to identify novel potential drugs. With this approach, ribonucleoside-diphosphate reductase gene (RRM2B) emerged as a candidate target and its inhibitor, 2', 2'-difluoro 2'deoxycytidine (gemcitabine), as a potential pharmaceutical drug against Alzheimer's disease. We functionally verified the effect of inhibiting the RRM2B homolog, rnr-2, in an Alzheimer's model of Caenorhabditis elegans, which accumulates human Aß1-42 peptide to an irreversible paralysis. RNA interference against rnr-2 and also treatment with 200 ng/ml of gemcitabine, showed an improvement of the phenotype. Gemcitabine treatment increased the intracellular ATP level 3.03 times, which may point to its mechanism of action. Gemcitabine has been extensively used in humans for cancer treatment but at higher concentrations. The 200 ng/ml concentration did not exert a significant effect over cell cycle, or affected cell viability when assayed in the microglia N13 cell line. Thus, the inhibitory drug of the RRM2B activity could be of potential use to treat Alzheimer's disease and particularly gemcitabine might be considered as a promising candidate to be repurposed for its treatment.

Analysing the Relationship Between Immigrant Status and the Severity of Offending Behaviour in Terms of Individual and Contextual Factors.

Background: Social inclusion is a context for both risk and protective factors of migrant youth delinquency. This study aims to shed light on the issue by comparing delinquency amongst native, first-generation, and second-generation immigrant youths in Portugal, a country located in the south of Europe, an area where research in this field is still scarce. Methods: The research is based on the International Self-Reported Delinquency (ISRD-3) dataset, which includes information on over 4,000 adolescents, who self-reported on their socio-demographic status, leisure activities, school and neighbourhood environment, family bonds, and self-control. Results: Nested Logistic Regression analyses showed that a young first-generation immigrant is twice as likely to commit a crime, with or without violence, as a young native born in Portugal. However, no differences were found regarding the prevalence of delinquency amongst second-generation immigrants and natives, which is likely due to the integration and cultural assimilation of the immigrant over time. Regarding the analysed risk factors, it was found that both structural and individual factors, identified by the theories of control, stress, as well as situational action theory, have a direct effect on the commission of juvenile crimes (both non-violent and violent). Moreover, this effect is significant in adolescents living in Portugal in general, both immigrants and natives. The most influential variable for both types of delinquent behaviour, with and without violence, is peer delinquency, followed by low morality and self-control. Conclusion: These findings have relevant policy implications and are useful for evidence-based interventions aimed at promoting migrant adolescent well-being and targeting host countries' performance.

Marco de trabajo para la práctica de la terapia ocupacional. Evolución histórica / Occupational therapy practice framework. Historical evolution

La AOTA ha publicado la Cuarta Edición del Marco de Trabajo para la Práctica de la terapia ocupacional: Dominio y Proceso. En este artículo vamos a hacer un recorrido por su historia desde el primer Marco de Trabajo publicado en el año 2002 pasando por cada una de sus revisiones realizadas cada 5 años hasta llegar a este cuarto Marco de Trabajo publicado el pasado año 2020. El objetivo es poder conocer tanto sus inicios como la evolución del mismo para lo que nos remontaremos a sus antecedentes: la Terminología Uniforme. (AU)

The objective is to be able to know both its beginnings and its evolution for which we will go back to its antecedents: the Uniform Terminology. The AOTA has published the Fourth Edition of the Framework for the Practice of Occupational Therapy: Domain and Process. In this article we are going to go through its history from the first Framework published in 2002, focusing on each review carried out every 5 years, ending with this fourth Framework published in 2020. The objective is to know both its beginnings and its evolution, and we go back to its antecedents: the Uniform Terminology. (AU)

Evolución técnica del marco de trabajo para la práctica de la terapia ocupacional: dominio y proceso / Occupational therapy practice framework: domain and process. Technical evolution

En el año 2020 se publica el nuevo Marco de Trabajo para la Práctica de la Terapia Ocupacional: Dominio y Proceso, 4ª edición,tras revisar las bases y procesos de la terapia ocupacional. En este documento queremos sintetizar y hacer más comprensiblestodos los cambios y avances técnicos que se han ido mostrando ennuestra profesión a lo largo de los diferentes documentos realizados por la Asociación Americana de Terapia Ocupacional. (AU)

In 2020 the new Occupational Therapy Practice Framework: Domain and Process, 4th edition was published after reviewing the bases and processes of occupational therapy. In this document we want to synthesize and make more understandable all the changes and technical advances that have been shown in our profession throughout the different documents produced by the American Occupational Therapy Association (AU)

¿Qué relación existe entre el marco de la AOTA y la CIF? / What is the relation between AOTA framework and ICF?

La revisión de los diferentes Marcos de Trabajo para la Práctica de la Terapia Ocupacional: dominio y proceso (OTPF) de la Asociación Americana de Terapia Ocupacional (AOTA) nos proporciona, ya desde su primera edición, continuas referencias a la Clasificación Internacional del Funcionamiento, Discapacidad y Salud (CIF).A través de este artículo pretendemos analizar la relación que existe entre el Marco de Trabajo para la Práctica de la Terapia Ocupacional de la AOTA y la Clasificación Internacional del Funcionamiento, Discapacidad y salud (CIF) y responder a una serie de cuestiones relativas a esta relación, llevando a cabo una revisión de artículos que versen sobre estos temas en las principales bases de datos de ciencias de la salud. (AU)

The review ofthe different Frameworks for the Practice of Occupational Therapy: domain and process (OTPF) of the American Occupational Therapy Association (AOTA) provides us, since its first edition, continuous references to the International Classification of Functioning, Disability and Health (ICF). In this article we intend to analyze the relation that exists between the AOTA Framework for the Practice of Occupational Therapy and the International Classification of Functioning, Disability and Health (ICF) and answersome questions related to this relationship. The articles dealing with these topics in the main health science databases are reviewe. (AU)

Prohibitin depletion extends lifespan of a TORC2/SGK-1 mutant through autophagy and the mitochondrial UPR.

Mitochondrial prohibitins (PHB) are highly conserved proteins with a peculiar effect on lifespan. While PHB depletion shortens lifespan of wild-type animals, it enhances longevity of a plethora of metabolically compromised mutants, including target of rapamycin complex 2 (TORC2) mutants sgk-1 and rict-1. Here, we show that sgk-1 mutants have impaired mitochondrial homeostasis, lipogenesis and yolk formation, plausibly due to alterations in membrane lipid and sterol homeostasis. Remarkably, all these features are suppressed by PHB depletion. Our analysis shows the requirement of SRBP1/SBP-1 for the lifespan extension of sgk-1 mutants and the further extension conferred by PHB depletion. Moreover, although the mitochondrial unfolded protein response (UPRmt ) and autophagy are induced in sgk-1 mutants and upon PHB depletion, they are dispensable for lifespan. However, the enhanced longevity caused by PHB depletion in sgk-1 mutants requires both, the UPRmt and autophagy, but not mitophagy. We hypothesize that UPRmt induction upon PHB depletion extends lifespan of sgk-1 mutants through autophagy and probably modulation of lipid metabolism.

Steroid hormones sulfatase inactivation extends lifespan and ameliorates age-related diseases.

Aging and fertility are two interconnected processes. From invertebrates to mammals, absence of the germline increases longevity. Here we show that loss of function of sul-2, the Caenorhabditis elegans steroid sulfatase (STS), raises the pool of sulfated steroid hormones, increases longevity and ameliorates protein aggregation diseases. This increased longevity requires factors involved in germline-mediated longevity (daf-16, daf-12, kri-1, tcer-1 and daf-36 genes) although sul-2 mutations do not affect fertility. Interestingly, sul-2 is only expressed in sensory neurons, suggesting a regulation of sulfated hormones state by environmental cues. Treatment with the specific STS inhibitor STX64, as well as with testosterone-derived sulfated hormones reproduces the longevity phenotype of sul-2 mutants. Remarkably, those treatments ameliorate protein aggregation diseases in C. elegans, and STX64 also Alzheimer's disease in a mammalian model. These results open the possibility of reallocating steroid sulfatase inhibitors or derivates for the treatment of aging and aging related diseases.

Dual RNAseq analyses at soma and germline levels reveal evolutionary innovations in the elephantiasis-agent Brugia malayi, and adaptation of its Wolbachia endosymbionts.

Brugia malayi is a human filarial nematode responsible for elephantiasis, a debilitating condition that is part of a broader spectrum of diseases called filariasis, including lymphatic filariasis and river blindness. Almost all filarial nematode species infecting humans live in mutualism with Wolbachia endosymbionts, present in somatic hypodermal tissues but also in the female germline which ensures their vertical transmission to the nematode progeny. These α-proteobacteria potentially provision their host with essential metabolites and protect the parasite against the vertebrate immune response. In the absence of Wolbachia wBm, B. malayi females become sterile, and the filarial nematode lifespan is greatly reduced. In order to better comprehend this symbiosis, we investigated the adaptation of wBm to the host nematode soma and germline, and we characterized these cellular environments to highlight their specificities. Dual RNAseq experiments were performed at the tissue-specific and ovarian developmental stage levels, reaching the resolution of the germline mitotic proliferation and meiotic differentiation stages. We found that most wBm genes, including putative effectors, are not differentially regulated between infected tissues. However, two wBm genes involved in stress responses are upregulated in the hypodermal chords compared to the germline, indicating that this somatic tissue represents a harsh environment to which wBm have adapted. A comparison of the B. malayi and C. elegans germline transcriptomes reveals a poor conservation of genes involved in the production of oocytes, with the filarial germline proliferative zone relying on a majority of genes absent from C. elegans. The first orthology map of the B. malayi genome presented here, together with tissue-specific expression enrichment analyses, indicate that the early steps of oogenesis are a developmental process involving genes specific to filarial nematodes, that likely result from evolutionary innovations supporting the filarial parasitic lifestyle.

A Founder Effect Led Early SARS-CoV-2 Transmission in Spain.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) whole-genome analysis has identified five large clades worldwide which emerged in 2019 (19A and 19B) and in 2020 (20A, 20B, and 20C). This study aimed to analyze the diffusion of SARS-CoV-2 in Spain using maximum-likelihood phylogenetic and Bayesian phylodynamic analyses. The most recent common ancestor (MRCA) of the SARS-CoV-2 pandemic was estimated to have emerged in Wuhan, China, around 24 November 2019. Phylogenetic analyses of the first 12,511 SARS-CoV-2 whole-genome sequences obtained worldwide, including 290 from 11 different regions of Spain, revealed 62 independent introductions of the virus in the country. Most sequences from Spain were distributed in clades characterized by a D614G substitution in the S gene (20A, 20B, and 20C) and an L84S substitution in ORF8 (19B) with 163 and 118 sequences, respectively, with the remaining sequences branching in 19A. A total of 110 (38%) sequences from Spain grouped in four different monophyletic clusters of clade 20A (20A-Sp1 and 20A-Sp2) and 19B clade (19B-Sp1 and 19B-Sp2) along with sequences from 29 countries worldwide. The MRCAs of clusters 19A-Sp1, 20A-Sp1, 19A-Sp2, and 20A-Sp2 were estimated to have occurred in Spain around 21 and 29 January and 6 and 17 February 2020, respectively. The prevalence of clade 19B in Spain (40%) was by far higher than in any other European country during the first weeks of the epidemic, probably as a result of a founder effect. However, this variant was replaced by G614-bearing viruses in April. In vitro assays showed an enhanced infectivity of pseudotyped virions displaying the G614 substitution compared with those having D614, suggesting a fitness advantage of D614G.IMPORTANCE Multiple SARS-CoV-2 introductions have been detected in Spain, and at least four resulted in the emergence of locally transmitted clusters that originated not later than mid-February, with further dissemination to many other countries around the world, and a few weeks before the explosion of COVID-19 cases detected in Spain during the first week of March. The majority of the earliest variants detected in Spain branched in the clade 19B (D614 viruses), which was the most prevalent clade during the first weeks of March, pointing to a founder effect. However, from mid-March to June 2020, G614-bearing viruses (clades 20A, 20B, and 20C) overcame D614 variants in Spain, probably as a consequence of an evolutionary advantage of this substitution in the spike protein. A higher infectivity of G614-bearing viruses than D614 variants was detected, suggesting that this substitution in SARS-CoV-2 spike protein could be behind the variant shift observed in Spain.

COVID-19 Vaccine Race: Analysis of Age-Dependent Immune Responses against SARS-CoV-2 Indicates that more than Just One Strategy May Be Needed.

In December 2019, a novel respiratory coronavirus named SARS-CoV-2 appeared in China, causing the disease termed COVID-19 that has caused millions of infections worldwide. In this article, we have analyzed existing evidence on the immune response against SARS coronaviruses in order to understand the possible outcome of a vaccine for COVID-19. From our analysis, it becomes clear that there is a big difference in the immune response against SARS in children, young adults and the elderly, both at the innate and adaptive levels. Taking this information into account, we have studied the strategies that are being used for the development of COVID-19 vaccines. We discussed the perspectives for obtention and worldwide distribution of reliable vaccines using this perspective. The conclusion is that different vaccines may be protective for different age segments within the population, depending on the strategy used for their design. Therefore, it will become necessary for several vaccines to reach the finish line, not only to ensure availability, but also to guarantee an adequate immune response at the individual level.

Cell-free biogenesis of bacterial division proto-rings that can constrict liposomes.

A major challenge towards the realization of an autonomous synthetic cell resides in the encoding of a division machinery in a genetic programme. In the bacterial cell cycle, the assembly of cytoskeletal proteins into a ring defines the division site. At the onset of the formation of the Escherichia coli divisome, a proto-ring consisting of FtsZ and its membrane-recruiting proteins takes place. Here, we show that FtsA-FtsZ ring-like structures driven by cell-free gene expression can be reconstituted on planar membranes and inside liposome compartments. Such cytoskeletal structures are found to constrict the liposome, generating elongated membrane necks and budding vesicles. Additional expression of the FtsZ cross-linker protein ZapA yields more rigid FtsZ bundles that attach to the membrane but fail to produce budding spots or necks in liposomes. These results demonstrate that gene-directed protein synthesis and assembly of membrane-constricting FtsZ-rings can be combined in a liposome-based artificial cell.

Antagonismo NMDA en el tratamiento de la cefalea en racimos / NMDA antagonism in the treatment of cluster headache

El tratamiento estándar de la cefalea en racimos consiste en un tratamiento abortivo con oxígeno, triptanes, alcaloides ergóticos y/o anestésico local nasal tópico durante los episodios agudos y un tratamiento preventivo, como infiltraciones con esteroides, antagonistas de los canales del calcio y litio. Aunque la fisiopatología exacta de la cefalea en racimos no se conoce bien, se han demostrado niveles reducidos de metabolitos de quinurenina, los cuales gozan de propiedades anti-NMDA (N-metil-D-aspartato). La ketamina y el magnesio, que tienen una potente actividad antagonista NMDA, se han usado en múltiples síndromes de dolor refractario. Describimos un caso de cefalea en racimos que no respondió al tratamiento estándar y se trató de forma efectiva con infusión intravenosa de magnesio y ketamina

Standard treatment for cluster headache consists of abortive treatment with oxygen, triptans, ergot alkaloids and/or topical nasal local anesthetic during acute episodes and preventive treatment such as steroid injections, calcium channel blockers and lithium. Although the exact pathophysiology of cluster headache is not well understood, reduced serum levels of kynurenine metabolites with anti-NMDA (N-methyl-D-aspartate) properties have been demonstrated. Ketamine and magnesium, which both have potent anti-NMDA receptor activity, have been used in multiple refractory pain syndromes. We describe a case of cluster headache that was non-responsive to standard therapy and treated effectively with intravenous infusion of magnesium and ketamine

Cross Cultural Analysis of Direct Employee Participation: Dealing With Gender and Cultural Values.

The goal of this study is analyze the influence of perceived supervisor support (PSS) by employees at a micro level and the role of the cultural values of "power distance" and "masculinity" at a macro level on direct employee participation in decision-making (PDM). Furthermore, the influence of the gender of managers and employees is taken into account. The analysis is based upon the Sixth European Working Conditions Survey carried out by Eurofound in 2016. The results of a Hierarchical linear model indicate that all predictors significantly influenced PDM; PSS positively and cultural values negatively. When the gender of managers and employees is considered, the findings suggest that PSS has a larger impact on PDM when male managers address female employees. Regarding the moderating effect of PSS on cultural values, it is shown that masculinity and power distance lose importance when employees have the support of their supervisors.

Síndrome de dolor miofascial como causa de dolor agudo postoperatorio en la cirugía de cadera / Myofascial pain syndrome as a cause of postoperative acute pain in hip surgery

El síndrome de dolor miofascial (SDM) es un cuadro de dolor regional de origen muscular. Normalmente se presenta como una causa de dolor crónico, siendo una patología no poco frecuente en las consultas de la Unidad de Dolor. El presente trabajo hace referencia al caso de un paciente intervenido de artroplastia de cadera que desarrolló un SDM en el postoperatorio inmediato, generando así una situación de dolor agudo postoperatorio. En este caso clínico se hace referencia a la gran importancia que tiene un correcto diagnóstico diferencial de cara al tratamiento de un síndrome doloroso. Como es sabido, los pacientes sometidos a cirugía de reemplazo articular experimentan un dolor postoperatorio intenso y sostenido si no se lleva a cabo una adecuada analgesia perioperatoria. El mal control del dolor impediría la recuperación precoz y el alta hospitalaria del paciente. En el caso que nos ocupa, el control del dolor perioperatorio fue llevado a cabo de forma satisfactoria, y no fue hasta el tercer día postintervención cuando apareció un dolor inguinal irradiado a muslo y rodilla que se acompañaba de espasmos musculares a la movilización, coincidiendo este hecho con el inicio de la rehabilitación del miembro. Hasta llegar al diagnóstico final, se descartó en primer lugar las causas atribuibles a la propia prótesis (luxación, fricción, mal posición...). Posteriormente se descartó una posible lesión nerviosa que pudiera haber tenido lugar durante el acto quirúrgico y, finalmente, tras la valoración por la Unidad del Dolor se sospechó un posible síndrome miofascial con afectación del músculo psoas derecho y se trató como tal. Para el tratamiento del cuadro se realizó una infiltración muscular con 40 mg de triamcinilona y 5 ml de levobupivacaína al 0,25 %. La localización se realizó mediante fluoroscopia y contraste hidrosoluble. Tras el procedimiento se obtuvo una clara mejoría sintomatológica, pudiendo comenzar el paciente nuevamente la rehabilitación del miembro. A los cuatro días de la infiltración con anestésico local y corticoides, el paciente volvió a presentar dolor de características similares al previo, por lo que se decidió realizar infiltraciones del músculo psoas derecho con 100 UI de toxina botulínica, además de repetir la dosis de anestésico local y corticoides ya realizada previamente, con el objetivo de controlar el dolor en el periodo ventana que se requiere hasta que la toxina botulínica surte efecto, obteniéndose resultados satisfactorios. Como ya hemos dicho, el dolor atribuido al síndrome miofascial suele presentarse como un dolor crónico, aunque en el caso que nos ocupa debutó en el postoperatorio inmediato, presentándose de forma aguda. En la literatura revisada solamente hay descrito un caso de SM en el postoperatorio de artroplastia de cadera, siendo más frecuente la aparición de este síndrome en la artroplastia de rodilla. No existe una causa clara que explique el motivo desencadenante del síndrome. En artroplastia de rodilla se habla de la isquemia intraoperatoria como posible factor desencadenante del PG, aunque esto no está demostrado

Myofascial pain syndrome (MPS) is a regional pain of muscular origin, usually presents as a cause of chronic pain, being a pathology not uncommon in the consultations of the Pain Unit. The present work refers to the case of a patient undergoing hip arthroplasty who developed an MDS in the immediate postoperative period, thus generating a situation of acute postoperative pain. In this clinical case reference is made to the great importance of a correct differential diagnosis for the treatment of a painful syndrome. As is known, patients undergoing joint replacement surgery experience intense and sustained postoperative pain if adequate perioperative analgesia is not carried out. Poor pain control would prevent early recovery and discharge from the patient. In the case in question, the control of perioperative pain was carried out satisfactorily, and it was not until the third day postintervention when an inguinal pain irradiated to the thigh and knee appeared that it was accompanied by muscular spasms to the mobilization. Coinciding this fact with the beginning of the rehabilitation of the member. Until the final diagnosis was reached, first the causes attributable to the prosthesis itself (dislocation, friction, malposition...) were discarded, later a possible nerve injury that could have occurred during the surgical act was ruled out and finally, after the evaluation for the Pain Unit, a possible myofascial syndrome with involvement of the right psoas muscle was suspected and treated as such. For the treatment of the condition, a muscle infiltration was performed with 40 mg of Triamcinilone and 5 ml of 0.25% levobupivacaine. The location was made by fluoroscopy and water-soluble contrast. After the procedure, a clear symptomatic improvement was obtained, and the patient could begin the rehabilitation of the limb again. After 4 days of infiltration with local anesthetic and corticosteroids, the patient presented pain similar to the previous one, so it was decided to perform infiltrations of the right psoas muscle with 100 IU of botulinum toxin, in addition to repeating the dose of local anesthetic and corticosteroids already done previously, with the aim of controlling the pain in the window period that is required until the botulinum toxin takes effect, obtaining satisfactory results. As we have already said, the pain attributed to the myofascial syndrome usually presents as a chronic pain, although in the present case it debuted in the immediate postoperative period, presenting itself acutely. In the literature reviewed, only one case of MS has been described in the postoperative period of hip arthroplasty, the occurrence of this syndrome being more frequent in knee arthroplasty. There is no clear cause to explain the reason for the syndrome. In knee arthroplasty, intraoperative ischemia is discussed as a possible triggering factor for PG, although this is not proven

Interfacial Activity of Phasin PhaF from Pseudomonas putida KT2440 at Hydrophobic-Hydrophilic Biointerfaces.

Phasins, the major proteins coating polyhydroxyalkanoate (PHA) granules, have been proposed as suitable biosurfactants for multiple applications because of their amphiphilic nature. In this work, we analyzed the interfacial activity of the amphiphilic α-helical phasin PhaF from Pseudomonas putida KT2440 at different hydrophobic-hydrophilic interfacial environments. The binding of PhaF to surfaces containing PHA or phospholipids, postulated as structural components of PHA granules, was confirmed in vitro using supported lipid bilayers and confocal microscopy, with polyhydroxyoctanoate- co-hexanoate P(HO- co-HHx) and Escherichia coli lipid extract as model systems. The surfactant-like capabilities of PhaF were determined by measuring changes in surface pressure in Langmuir devices. PhaF spontaneously adsorbed at the air-water interface, reducing the surface tension from 72 mN/m (water surface tension at 25 °C) to 50 mN/m. The differences in the adsorption of the protein in the presence of different phospholipid films showed a marked preference for phosphatidylglycerol species, such as 1-palmitoyl-2-oleoyl- sn-glycero-3-phosphoglycerol. The PHA-binding domain of PhaF (BioF) conserved a similar surface activity to PhaF, suggesting that it is responsible for the surfactant properties of the whole protein. These new findings not only increase our knowledge about the role of phasins in the PHA machinery but also open new outlooks for the application of these proteins as biosurfactants.

Escherichia coli ZipA Organizes FtsZ Polymers into Dynamic Ring-Like Protofilament Structures.

ZipA is an essential cell division protein in Escherichia coli Together with FtsA, ZipA tethers dynamic polymers of FtsZ to the cytoplasmic membrane, and these polymers are required to guide synthesis of the cell division septum. This dynamic behavior of FtsZ has been reconstituted on planar lipid surfaces in vitro, visible as GTP-dependent chiral vortices several hundred nanometers in diameter, when anchored by FtsA or when fused to an artificial membrane binding domain. However, these dynamics largely vanish when ZipA is used to tether FtsZ polymers to lipids at high surface densities. This, along with some in vitro studies in solution, has led to the prevailing notion that ZipA reduces FtsZ dynamics by enhancing bundling of FtsZ filaments. Here, we show that this is not the case. When lower, more physiological levels of the soluble, cytoplasmic domain of ZipA (sZipA) were attached to lipids, FtsZ assembled into highly dynamic vortices similar to those assembled with FtsA or other membrane anchors. Notably, at either high or low surface densities, ZipA did not stimulate lateral interactions between FtsZ protofilaments. We also used E. coli mutants that are either deficient or proficient in FtsZ bundling to provide evidence that ZipA does not directly promote bundling of FtsZ filaments in vivo Together, our results suggest that ZipA does not dampen FtsZ dynamics as previously thought, and instead may act as a passive membrane attachment for FtsZ filaments as they treadmill.IMPORTANCE Bacterial cells use a membrane-attached ring of proteins to mark and guide formation of a division septum at midcell that forms a wall separating the two daughter cells and allows cells to divide. The key protein in this ring is FtsZ, a homolog of tubulin that forms dynamic polymers. Here, we use electron microscopy and confocal fluorescence imaging to show that one of the proteins required to attach FtsZ polymers to the membrane during E. coli cell division, ZipA, can promote dynamic swirls of FtsZ on a lipid surface in vitro Importantly, these swirls are observed only when ZipA is present at low, physiologically relevant surface densities. Although ZipA has been thought to enhance bundling of FtsZ polymers, we find little evidence for bundling in vitro In addition, we present several lines of in vivo evidence indicating that ZipA does not act to directly bundle FtsZ polymers.

Wolbachia Control Stem Cell Behavior and Stimulate Germline Proliferation in Filarial Nematodes.

Although symbiotic interactions are ubiquitous in the living world, examples of developmental symbioses are still scarce. We show here the crucial role of Wolbachia in the oogenesis of filarial nematodes, a class of parasites of biomedical and veterinary relevance. We applied newly developed techniques to demonstrate the earliest requirements of Wolbachia in the parasite germline preceding the production of faulty embryos in Wolbachia-depleted nematodes. We show that Wolbachia stimulate germline proliferation in a cell-autonomous manner, and not through nucleotide supplementation as previously hypothesized. We also found Wolbachia to maintain the quiescence of a pool of germline stem cells to ensure a constant delivery of about 1,400 eggs per day for many years. The loss of quiescence upon Wolbachia depletion as well as the disorganization of the distal germline suggest that Wolbachia are required to execute the proper germline stem cell developmental program in order to produce viable eggs and embryos.

Effect of polymorphisms in transporter genes on dosing, efficacy and toxicity of maintenance therapy in children with acute lymphoblastic leukemia.

The aim of the present work was to assess whether polymorphisms in genes coding for drug transport proteins may influence dosing, efficacy and toxicity of maintenance therapy with methotrexate (MTX) and 6-mercaptopurine (6MP) in childhood acute lymphoblastic leukemia (ALL). A total of 41 children with ALL were screened for 10 SNPs in the SLC19A1, ABCB1, ABCC2, ABCC4 and ABCG2 transporter genes by means of direct sequencing. Carriers of the ABCC4 934CC and ABCB1 1236TT genotypes received a lower percentage of the protocol-recommended starting dose of MTX (62.1 vs. 81.3% for 934CA carriers, p=0.001) and 6MP (73.1 vs. 87.7% for 1236CC/CT carriers; p=0.026), respectively. The C1236T SNP also increased the efficiency of myelosuppression. Median (and interquartile) number of blood tests with leukocytes levels <3109/L for the CC; CT and TT genotypes were 22 (13), 30.5 (11.75) and 33 (17.25), respectively (p=0.001). In addition, this SNP also correlated with the number of hematological adverse events (p=0.004 for the difference between same genotypes). The event more profoundly affected was neutropenia (p=0.004). In the same manner, the ABCC4 934CC genotype was also associated to more frequent hematological toxicity (p=0.041 vs. CT carriers) and raised LDH levels (p=0.004 vs. CT carriers); although only the latter association remained significant after correction by multiple testing. Overall, our findings indicate that variability in the ABCB1 and ABCC4 genes may confer higher sensitivity to maintenance chemotherapy of ALL, and therefore its determination may be helpful in individualizing this treatment.

Dihydrofolate Reductase Genetic Polymorphisms Affect Methotrexate Dose Requirements in Pediatric Patients With Acute Lymphoblastic Leukemia on Maintenance Therapy.

We have aimed to determine the effect of polymorphisms in regulatory regions of the DHFR gene in relation to methotrexate (MTX) dose adjustments and drug-induced toxicity in children on maintenance therapy for acute lymphoblastic leukemia (ALL). In total, 41 children diagnosed with ALL were screened for 3 tag-single nucleotide polymorphisms in the DHFR promoter (C-1610G, C-680G/T, A-317G) and an intronic 19-bp insertion/deletion. Genotypes were analyzed in relation to dose requirements and toxicity. The percentage of MTX dose administered (with respect to protocol-recommended values) was affected by DHFR polymorphisms. Carriers of the -680AA genotype displayed a median percentage of 44.08 (interquartile range=34.69), compared with 77.98 (interquartile range=33.90) for CC and CA carriers (P=0.01). The number of counts within white blood cell therapeutic range (2.0 to 3.0×10/L) was higher for -680AA carriers than for CC/CA carriers (P=0.003). With regard to toxicity, carriers of the -680AA genotype displayed more treatment interruptions than CC/CG carriers (P=0.03), as well as more episodes of severe neutropenia (P=0.04) and higher number of blood counts with elevated levels (>400 mg/dL) of lactate dehidrogenase (P=0.04). Overall, our findings suggest that the identification of DHFR polymorphisms in the promoter region of the gene may be helpful in tailoring MTX doses for ALL pediatric patients on maintenance therapy.