The peroxisome protein translocation machinery is developmentally regulated in the fungus Podospora anserina.

IMPORTANCE: Sexual reproduction allows eukaryotic organisms to produce genetically diverse progeny. This process relies on meiosis, a reductional division that enables ploidy maintenance and genetic recombination. Meiotic differentiation also involves the renewal of cell functioning to promote offspring rejuvenation. Research in the model fungus Podospora anserina has shown that this process involves a complex regulation of the function and dynamics of different organelles, including peroxisomes. These organelles are critical for meiosis induction and play further significant roles in meiotic development. Here we show that PEX13-a key constituent of the protein conduit through which the proteins defining peroxisome function reach into the organelle-is subject to a developmental regulation that almost certainly involves its selective ubiquitination-dependent removal and that modulates its abundance throughout meiotic development and at different sexual differentiation processes. Our results show that meiotic development involves a complex developmental regulation of the peroxisome protein translocation system.

Point-of-Care Ultrasound for the Diagnosis of Frequent Cardiovascular Diseases: A Review.

Point-of-care ultrasound (POCUS) has emerged as an indispensable diagnostic tool in cardiology, particularly within the emergency department. This narrative synthesis provides a comprehensive exploration of POCUS applications in cardiovascular diseases, elucidating its multifaceted roles and addressing challenges. The review delves into the technical attributes of POCUS, emphasizing its non-invasive nature, radiation-free qualities, and suitability for non-radiologists. It navigates through educational strategies, stressing the importance of structured programs for the seamless integration of POCUS into clinical practice. Highlighting its efficacy, the synthesis discusses POCUS applications in various scenarios such as dyspnea, chest pain, cardiac arrest, aortic dissection, pericardial effusion, and pulmonary embolism. Beyond acute care, the review explores the role of POCUS in outpatient and inpatient settings, focusing on chronic and acute heart failure, valvular heart diseases, and more. Acknowledging operator-dependent challenges and the need for continuous education, the review underscores the transformative potential of POCUS across diverse healthcare settings. This narrative synthesis accentuates POCUS as a valuable and versatile diagnostic tool in cardiology, offering efficiency, safety, and cost-effectiveness. Despite challenges, POCUS stands out as a transformative addition to clinical practices, poised to enhance patient outcomes and reshape the landscape of cardiovascular diagnostics.

Spatiotemporal Dynamic Regulation of Organelles During Meiotic Development, Insights From Fungi.

Eukaryotic cell development involves precise regulation of organelle activity and dynamics, which adapt the cell architecture and metabolism to the changing developmental requirements. Research in various fungal model organisms has disclosed that meiotic development involves precise spatiotemporal regulation of the formation and dynamics of distinct intracellular membrane compartments, including peroxisomes, mitochondria and distinct domains of the endoplasmic reticulum, comprising its peripheral domains and the nuclear envelope. This developmental regulation implicates changes in the constitution and dynamics of these organelles, which modulate their structure, abundance and distribution. Furthermore, selective degradation systems allow timely organelle removal at defined meiotic stages, and regulated interactions between membrane compartments support meiotic-regulated organelle dynamics. This dynamic organelle remodeling is implicated in conducting organelle segregation during meiotic differentiation, and defines quality control regulatory systems safeguarding the inheritance of functional membrane compartments, promoting meiotic cell rejuvenation. Moreover, organelle remodeling is important for proper activity of the cytoskeletal system conducting meiotic nucleus segregation, as well as for meiotic differentiation. The orchestrated regulation of organelle dynamics has a determinant contribution in the formation of the renewed genetically-diverse offspring of meiosis.

Barriers and Enablers for Integrating Public Health Cobenefits in Urban Climate Policy.

Urban climate policy offers a significant opportunity to promote improved public health. The evidence around climate and health cobenefits is growing but has yet to translate into widespread integrated policies. This article presents two systematic reviews: first, looking at quantified cobenefits of urban climate policies, where transportation, land use, and buildings emerge as the most studied sectors; and second, looking at review papers exploring the barriers and enablers for integrating these health cobenefits into urban policies. The latter reveals wide agreement concerning the need to improve the evidence base for cobenefits and consensus about the need for greater political will and leadership on this issue. Systems thinking may offer a way forward to help embrace complexity and integrate health cobenefits into decision making. Knowledge coproduction to bring stakeholders together and advance policy-relevant research for urban health will also be required. Action is needed to bring these two important policy agendas together.

Spindle Dynamics during Meiotic Development of the Fungus Podospora anserina Requires the Endoplasmic Reticulum-Shaping Protein RTN1.

The endoplasmic reticulum (ER) is an elaborate organelle composed of distinct structural and functional domains. ER structure and dynamics involve membrane-shaping proteins of the reticulon and Yop1/DP1 families, which promote membrane curvature and regulate ER shaping and remodeling. Here, we analyzed the function of the reticulon (RTN1) and Yop1 proteins (YOP1 and YOP2) of the model fungus Podospora anserina and their contribution to sexual development. We found that RTN1 and YOP2 localize to the peripheral ER and are enriched in the dynamic apical ER domains of the polarized growing hyphal region. We discovered that the formation of these domains is diminished in the absence of RTN1 or YOP2 and abolished in the absence of YOP1 and that hyphal growth is moderately reduced when YOP1 is deleted in combination with RTN1 and/or YOP2. In addition, we found that RTN1 associates with the Spitzenkörper. Moreover, RTN1 localization is regulated during meiotic development, where it accumulates at the apex of growing asci (meiocytes) during their differentiation and at their middle region during the subsequent meiotic progression. Furthermore, we discovered that loss of RTN1 affects ascospore (meiotic spore) formation, in a process that does not involve YOP1 or YOP2. Finally, we show that the defects in ascospore formation of rtn1 mutants are associated with defective nuclear segregation and spindle dynamics throughout meiotic development. Our results show that sexual development in P. anserina involves a developmental remodeling of the ER that implicates the reticulon RTN1, which is required for meiotic nucleus segregation. IMPORTANCE Meiosis consists of a reductional cell division, which allows ploidy maintenance during sexual reproduction and which provides the potential for genetic recombination, producing genetic variation. Meiosis constitutes a process of foremost importance for eukaryotic evolution. Proper partitioning of nuclei during this process relies on accurate functioning and positioning of the spindle, the microtubule cytoskeletal apparatus that conducts chromosome segregation. In this research, we show that in the model fungus Podospora anserina this process requires a protein involved in structuring the endoplasmic reticulum (ER)-the reticulon RTN1. The ER is a complex organelle composed of distinct structural domains, including different peripheral domains and the nuclear envelope. Our findings suggest that spindle dynamics during meiosis relies on remodeling of the ER membrane, which involves the activity of RTN1. Our research discloses that the proteins implicated in shaping the ER are main contributors to the regulation of nuclear dynamics during the sexual cycle.

Mucocele apendicular simulando apendicitis aguda complicada / Appendicular mucocele simulating complicated acute appendicitis / Mucocele apendicular simulando apendicite aguda complicada

RESUMEN Introducción: el término «mucocele¼, una denominación no específica y descriptiva referida a una acumulación mucosa anormal dentro de la luz del apéndice, independientemente de la causa subyacente, es una afección clínica rara que con poca frecuencia se considera en el diagnóstico diferencial de las lesiones localizadas en el cuadrante inferior derecho del abdomen. Objetivo: presentar un paciente con diagnóstico preoperatorio de apendicitis aguda complicada que fue intervenido quirúrgicamente de urgencia y se le diagnosticó finalmente un mucocele apendicular. Presentación del caso: paciente masculino de 52 años que fue admitido en la Unidad de Cuidados Intensivos y Emergentes por presentar dolor en la región lumbar derecha que se irradió a fosa iliaca derecha. Se acompañó de náuseas, vómitos abundantes, fiebre de 38,5-390 C, sed, oliguria, astenia y anorexia. Discusión: a la exploración física presentó mucosas pálidas y ligeramente secas, pulso débil y taquicárdico, hipotensión arterial, abdomen ligeramente distendido, doloroso a la palpación profunda en fosa ilíaca derecha. Los estudios imagenológicos sugirieron una colección apendicular. Con la sospecha clínica de apendicitis aguda complicada y ante la duda diagnóstica se decidió realizar laparotomía exploradora de urgencia. Durante el transoperatorio se identificó un mucocele apendicular. La histología confirmó un mucocele apendicular sin evidencia de origen neoplásico. El paciente evolucionó satisfactoriamente y se le dio de alta al cuarto dia posoperatorio. Conclusiones: el mucocele apendicular es una afección clínica-quirúrgica que, a pesar de ser conocida, su incidencia es muy baja; siendo el diagnóstico preoperatorio difícil por la variedad en su presentación clínica.

ABSTRACT Introduction: the term «mucocele¼, a nonspecific and descriptive name referring to an abnormal mucous accumulation within the lumen of the appendix, regardless of the underlying cause, is a rare clinical condition that is infrequently considered in the differential diagnosis of the lesions located in the lower right quadrant of the abdomen. Objective: to present a patient with a preoperative diagnosis of complicated acute appendicitis who underwent emergency surgery and was finally diagnosed with an appendicular mucocele. Clinical case: 52-year-old male patient who was admitted to the Emergency and Intensive Care Unit for presenting pain in the right lumbar region that radiated to the right iliac fossa. He was accompanied by nausea, profuse vomiting, fever of 38.5-390 C, thirst, oliguria, asthenia, and anorexia. Discussion: on physical examination, she presented pale and slightly dry mucous membranes, weak and tachycardic pulse, arterial hypotension, slightly distended abdomen, painful on deep palpation in the right iliac fossa. Imaging studies suggested an appendicular collection. With the clinical suspicion of complicated acute appendicitis and the diagnostic doubt, it was decided to perform emergency exploratory laparotomy. During the intraoperative period, anappendicular mucocele was identified. Histology confirmed an appendicular mucocele with no evidence of neoplastic origin. The patient evolved satisfactorily and was discharged on the fourth postoperative day. Conclusions: the appendicular mucoceleis a clinical-surgical condition that, despite being known, its incidence is very low; being the preoperative diagnosis difficult due to the variety in its clinical presentation.

RESUMO Introdução: o termo "mucocele", nome inespecífico e descritivo que se refere a um acúmulo anormal de muco dentro da luz do apêndice, independente da causa subjacente, é uma condição clínica rara, raramente considerada no diagnóstico diferencial das lesões localizado no quadrante inferior direito do abdômen. Objetivo: apresentar um paciente com diagnóstico pré-operatório de apendicite aguda complicada, submetido a cirurgia de urgência e com diagnóstico de mucocele apendicular. Caso clínico: Paciente do sexo masculino, 52 anos, que deu entrada no Pronto Socorro e na Unidade de Terapia Intensiva por apresentar dor em região lombar direita com irradiação para fossa ilíaca direita. Foi acompanhada de náuseas, vômitos profusos, febre 38,5-390 C, sede, oligúria, astenia e anorexia. Discussão: ao exame físico apresentava mucosas pálidas e levemente ressecadas, pulso fraco e taquicárdico, hipotensão arterial, abdome levemente distendido, doloroso à palpação profunda em fossa ilíaca direita. Estudos de imagem sugeriram uma coleção apendicular. Com a suspeita clínica de apendicite aguda complicada e a dúvida diagnóstica, optou-se pela realização de laparotomia exploradora de emergência. No intraoperatório, foi identificada mucocele apendicular. A histologia confirmou uma mucocele apendicular sem evidência de origem neoplásica. A paciente evoluiu satisfatoriamente e recebeu alta hospitalar no quarto dia de pós-operatório. Conclusões: amucocele apendicular é uma condição clínico-cirúrgica que, apesar de conhecida, é muito baixa; sendo o diagnóstico pré-operatório difícil pela variedade de sua apresentação clínica.

Mucocele apendicular simulando apendicitis aguda complicada / Appendicular mucocele simulating complicated acute appendicitis

Introducción: el término mucocele, una denominación no específica y descriptiva referida a una acumulación mucosa anormal dentro de la luz del apéndice, independientemente de la causa subyacente, es una afección clínica rara que con poca frecuencia se considera en el diagnóstico diferencial de las lesiones localizadas en el cuadrante inferior derecho del abdomen. Objetivo: presentar un paciente con diagnóstico preoperatorio de apendicitis aguda complicada que fue intervenido quirúrgicamente de urgencia y se le diagnosticó finalmente un mucocele apendicular. Presentación del caso: paciente masculino de 52 años que fue admitido en la Unidad de Cuidados Intensivos y Emergentes por presentar dolor en la región lumbar derecha que se irradió a fosa iliaca derecha. Se acompañó de náuseas, vómitos abundantes, fiebre de 38,5-39 0C, sed, oliguria, astenia y anorexia. Discusión: ala exploración física presentó mucosas pálidas y ligeramente secas, pulso débil y taquicárdico, hipotensión arterial, abdomen ligeramente distendido, doloroso a la palpación profunda en fosa ilíaca derecha. Los estudios imagenológicos sugirieron una colección apendicular. Con la sospecha clínica de apendicitis aguda complicada y ante la duda diagnóstica se decidió realizar laparotomía exploradora de urgencia. Durante el transoperatorio se identificó un mucocele apendicular. La histología confirmó un mucocele apendicular sin evidencia de origen neoplásico. El paciente evolucionó satisfactoriamente y se le dio de alta al cuarto dia posoperatorio. Conclusiones: el mucocele apendicular es una afección clínica-quirúrgica que, a pesar de ser conocida, su incidencia es muy baja; siendo el diagnóstico preoperatorio difícil por la variedad en su presentaciónclínica(AU)

Introduction: the term mucocele, a nonspecific and descriptive name referring to an abnormal mucous accumulation within the lumen of the appendix, regardless of the underlying cause, is a rare clinical condition that is infrequently considered in the differential diagnosis of the lesions located in the lower right quadrant of the abdomen. Objective: to present a patient with a preoperative diagnosis of complicated acute appendicitis who underwent emergency surgery and was finally diagnosed with an appendicular mucocele. Clinical case: 52-year-old male patient who was admitted to the Emergency and Intensive Care Unit for presenting pain in the right lumbar region that radiated to the right iliac fossa. He was accompanied by nausea, profuse vomiting, fever of 38.5-39 0C, thirst, oliguria, asthenia, and anorexia. Discussion: on physical examination, she presented pale and slightly dry mucous membranes, weak and tachycardic pulse, arterial hypotension, slightly distended abdomen, painful on deep palpation in the right iliac fossa. Imaging studies suggested an appendicular collection. With the clinical suspicion of complicated acute appendicitis and the diagnostic doubt, it was decided to perform emergency exploratory laparotomy. During the intraoperative period, an appendicular mucocele was identified. Histology confirmed an appendicular mucocele with no evidence of neoplastic origin. The patient evolved satisfactorily and was dischanged on the fourth postoperative day. Conclusions: the appendicular mucocele is a clinical-surgical condition that, despite being known, its incidence is very low; being the preoperative diagnosis difficult due to the variety in its clinical presentation(EU)

The taxonomy of the model filamentous fungus Podospora anserina.

The filamentous fungus Podospora anserina has been used as a model organism for more than 100 years and has proved to be an invaluable resource in numerous areas of research. Throughout this period, P. anserina has been embroiled in a number of taxonomic controversies regarding the proper name under which it should be called. The most recent taxonomic treatment proposed to change the name of this important species to Triangularia anserina. The results of past name changes of this species indicate that the broader research community is unlikely to accept this change, which will lead to nomenclatural instability and confusion in literature. Here, we review the phylogeny of the species closely related to P. anserina and provide evidence that currently available marker information is insufficient to resolve the relationships amongst many of the lineages. We argue that it is not only premature to propose a new name for P. anserina based on current data, but also that every effort should be made to retain P. anserina as the current name to ensure stability and to minimise confusion in scientific literature. Therefore, we synonymise Triangularia with Podospora and suggest that either the type species of Podospora be moved to P. anserina from P. fimiseda or that all species within the Podosporaceae be placed in the genus Podospora.

Dynamic Regulation of Peroxisomes and Mitochondria during Fungal Development.

Peroxisomes and mitochondria are organelles that perform major functions in the cell and whose activity is very closely associated. In fungi, the function of these organelles is critical for many developmental processes. Recent studies have disclosed that, additionally, fungal development comprises a dynamic regulation of the activity of these organelles, which involves a developmental regulation of organelle assembly, as well as a dynamic modulation of the abundance, distribution, and morphology of these organelles. Furthermore, for many of these processes, the dynamics of peroxisomes and mitochondria are governed by common factors. Notably, intense research has revealed that the process that drives the division of mitochondria and peroxisomes contributes to several developmental processes-including the formation of asexual spores, the differentiation of infective structures by pathogenic fungi, and sexual development-and that these processes rely on selective removal of these organelles via autophagy. Furthermore, evidence has been obtained suggesting a coordinated regulation of organelle assembly and dynamics during development and supporting the existence of regulatory systems controlling fungal development in response to mitochondrial activity. Gathered information underscores an important role for mitochondrial and peroxisome dynamics in fungal development and suggests that this process involves the concerted activity of these organelles.

Distinct Contributions of the Peroxisome-Mitochondria Fission Machinery During Sexual Development of the Fungus Podospora anserina.

Mitochondria and peroxisomes are organelles whose activity is intimately associated and that play fundamental roles in development. In the model fungus Podospora anserina, peroxisomes and mitochondria are required for different stages of sexual development, and evidence indicates that their activity in this process is interrelated. Additionally, sexual development involves precise regulation of peroxisome assembly and dynamics. Peroxisomes and mitochondria share the proteins mediating their division. The dynamin-related protein Dnm1 (Drp1) along with its membrane receptors, like Fis1, drives this process. Here we demonstrate that peroxisome and mitochondrial fission in P. anserina depends on FIS1 and DNM1. We show that FIS1 and DNM1 elimination affects the dynamics of both organelles throughout sexual development in a developmental stage-dependent manner. Moreover, we discovered that the segregation of peroxisomes, but not mitochondria, is affected upon elimination of FIS1 or DNM1 during the division of somatic hyphae and at two central stages of sexual development-the differentiation of meiocytes (asci) and of meiotic-derived spores (ascospores). Furthermore, we found that FIS1 and DNM1 elimination results in delayed karyogamy and defective ascospore differentiation. Our findings reveal that sexual development relies on complex remodeling of peroxisomes and mitochondria, which is driven by their common fission machinery.

An endoplasmic reticulum domain is associated with the polarized growing cells of Podospora anserina hyphae.

The endoplasmic reticulum (ER) is composed of distinct structural domains that perform diverse essential functions, including the synthesis of membrane lipids and proteins of the cell endomembrane system. The polarized growth of fungal hyphal cells depends on a polarized secretory system, which delivers vesicles to the hyphal apex for localized cell expansion, and that involves a polarized distribution of the secretory compartments, including the ER. Here we show that, additionally, the ER of the ascomycete Podospora anserina possesses a peripheral ER domain consisting of highly dynamic pleomorphic ER sub-compartments, which are specifically associated with the polarized growing apical hyphal cells.

Atomic-Scale Investigation on the Evolution of Tio2-Anatase Prepared by a Sonochemical Route and Treated with NaOH.

To date, the formation mechanisms of TiO2, as well as its heterostructures, have not been clarified. Moreover, detailed research on the transition from a tetragonal anatase phase to the monoclinic phase of the TiO2(B) phase and their interface structure has been quite limited until now. In the present study, we report on the sonochemical synthesis of TiO2-anatase with a crystallite size of 5.2 ± 1.5 nm under different NaOH concentrations via the hydrothermal method. The use of alkaline solution and the effect of the temperature and reaction time on the formation and structural properties of TiO2-anatase nanopowders were studied. The effects of NaOH concentration on the formation and transformation of titanate structures are subject to thermal effects that stem from the redistribution of energy in the system. These mechanisms could be attributed to three phenomena: (1) the self-assembly of nanofibers and nanosheets, (2) the Ostwald ripening process, and (3) the self-development of hollow TiO2 mesostructures.

Intercalated Intermetallic Compounds AlTi3 and Fe2Ti in Microrods and Microtubes Obtained by Invariant Reaction of Mechanically Milled System Al43Ti36Fe21.

This paper reports the production of intermetallic microrods and microtubes from the decomposition of an intermetallic compound in an AlTiFe system. The intermetallic compound was obtained by mechanosynthesis of elemental powders of Al, Ti and Fe over 300 h at 400 rpm, sintering from compacted powder particles at 300 MPa per minute and at 900 °C for 3600 s in an argon atmosphere. The milled and sintered samples were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). The intermetallic AlTi3 and Fe3Al phases were obtained during the milling process. After sintering, a decomposition of these intermetallic phases was found-Al3Ti0.75Fe0.25, Al3Ti, FeTi, AlTi3, Ti9Al23, Fe2Ti, Al86Fe14 and Al0.4Fe0.6. As a result of the decomposition, we observed the formation of hexagonal rods with intercalated phases of AlTi3 and Fe2Ti.

Neurospora crassa NADPH Oxidase NOX-1 Is Localized in the Vacuolar System and the Plasma Membrane.

The NADPH oxidases (NOX) catalyze the production of superoxide by transferring electrons from NADPH to O2, in a regulated manner. In Neurospora crassa NOX-1 is required for normal growth of hyphae, development of aerial mycelium and asexual spores, and it is essential for sexual differentiation and cell-cell fusion. Determining the subcellular localization of NOX-1 is a critical step in understanding the mechanisms by which this enzyme can regulate all these different processes. Using fully functional versions of NOX-1 tagged with mCherry, we show that in growing hyphae NOX-1 shows only a minor association with the endoplasmic reticulum (ER) markers Ca2+-ATPase NCA-1 and an ER lumen-targeted GFP. Likewise, NOX-1 shows minor co-localization with early endosomes labeled with YPT-52, a GTPase of the Rab5 family. In contrast, NOX-1 shows extensive co-localization with two independent markers of the entire vacuolar system; the vacuolar ATPase subunit VMA-1 and the fluorescent molecule carboxy-DFFDA. In addition, part of NOX-1 was detected at the plasma membrane. The NOX-1 regulatory subunit NOR-1 displays a very different pattern of localization, showing a fine granular distribution along the entire hypha and some accumulation at the hyphal tip. In older hyphal regions, germinating conidia, and conidiophores it forms larger and discrete puncta some of which appear localized at the plasma membrane and septa. Notably, co-localization of NOX-1 and NOR-1 was mainly observed under conidial cell-cell fusion conditions in discrete vesicular structures. NOX functions in fungi have been evaluated mainly in mutants that completely lacked this protein, also eliminating interactions between hyphal growth regulatory proteins NOR-1, the GTPase RAC-1 and the scaffold protein BEM-1. To dissect NOX-1 roles as scaffold and as ROS-producing enzyme, we analyzed the function of NOX-1::mCherry proteins carrying proline 382 by histidine (P382H) or cysteine 524 by arginine (C524R) substitutions, predicted to only affect NADPH-binding. Without notably affecting NOX-1 localization or protein levels, each of these substitutions resulted in lack of function phenotypes, indicating that NOX-1 multiple functions are all dependent on its oxidase activity. Our results open new interpretations to possible NOX functions, as components of the fungal vacuolar system and the plasma membrane, as well as to new vacuolar functions.

Meiotic development initiation in the fungus Podospora anserina requires the peroxisome receptor export machinery.

Peroxisomes are versatile organelles essential for diverse developmental processes. One such process is the meiotic development of Podospora anserina. In this fungus, absence of the docking peroxin PEX13, the RING-finger complex peroxins, or the PTS2 co-receptor PEX20 blocks sexual development before meiocyte formation. However, this defect is not seen in the absence of the receptors PEX5 and PEX7, or of the docking peroxins PEX14 and PEX14/17. Here we describe the function of the remaining uncharacterized P. anserina peroxins predictably involved in peroxisome matrix protein import. We show that PEX8, as well as the peroxins potentially mediating receptor monoubiquitination (PEX4 and PEX22) and membrane dislocation (PEX1, PEX6 and PEX26) are indeed implicated in peroxisome matrix protein import in this fungus. However, we observed that elimination of PEX4 and PEX22 affects to different extent the import of distinct PEX5 cargoes, suggesting differential ubiquitination-complex requirements for the import of distinct proteins. In addition, we found that elimination of PEX1, PEX6 or PEX26 results in loss of peroxisomes, suggesting that these peroxins restrain peroxisome removal in specific physiological conditions. Finally, we demonstrate that all analyzed peroxins are required for meiocyte formation, and that PEX20 function in this process depends on its potential monoubiquitination target cysteine. Our results suggest that meiotic induction relies on a peroxisome import pathway, which is not dependent on PEX5 or PEX7 but that is driven by an additional cycling receptor. These findings uncover a collection of peroxins implicated in modulating peroxisome activity to facilitate a critical developmental cell fate decision.

Selección de un ciclotrón para la producción de radionúclidos de uso en medicina nuclear. Experiencia Cubana / Selection of cyclotron for the production of radionuclides for nuclear medicine. Cuban experience

En el trabajo se ofrecen argumentos para la selección de un ciclotrón de 18 MeV en protones, en su variante Twin. Estará dedicado solo a reacciones nucleares con dichas partículas a los efectos de asegurar el suministro en Cuba de radionúclidos para la tomografía de emisión positrónica (PET) (fundamentalmente ), así como en perspectiva Iodo- para tomografía de emisión de fotón simple (SPECT). Se dan datos que indican la posibilidad de suministrar -FDG al menos a cinco centros PET. Ello posibilitará el acceso de Cuba a una de las más avanzadas tecnología de imagen, el PET/TAC, con el consiguiente beneficio para la atención a pacientes afectados de cáncer y enfermedades cardiovasculares y neurológicas

The work provides arguments for the selection of 18 MeV cyclotron in protons, in its Twin variant. It will be used only for nuclear reactions with these particles in order to ensure the supply of radionuclides in Cuba, for the positron emission tomography ( mainly) as well as for single photon emission computed tomography (, for example), in the future. Data indicating the possibility of supplying -FDG to at least five PET centers are given. This shall allow Cuba to access the one of the most advanced imaging technology, with the consequent benefit for patients suffering from cancer, cardiovascular and neurological diseases

[The aging of Mexican population]. / El envejecimiento de la población mexicana.

No abstract.

En México, la cuestión relacionada con el envejecimiento de nuestra población debe ser considerada un tema prioritario, debido a que se ha presentado un aumento de tal magnitud, que a inicios del siglo XXI las personas que tenían una edad mayor de 65 años no sobrepasaban los cinco millones de habitantes, mientras que la Encuesta Intercensal 2015 reportó que en el 2015 había 12.4 millones de personas mayores de 65 años.1 Asimismo, según estimaciones del Instituto Nacional de Estadística y Geografía (INEGI), se prevé que para el año 2030, la población mayor de 60 años será de más de 20 millones de individuos y para el 2050 se estima que esta población de adultos mayores constituirá el 27.7% de la población mexicana.2 Esta situación está relacionada con los avances médicos y científicos, gracias a los cuales se ha alcanzado en 2015 una esperanza de vida que, según el INEGI y la Secretaría de Salud, en hombres fue de 72.3 años y en mujeres de 77.4, y se tiene proyectado que para el 2020 en hombres sea de 73.3 y en mujeres de 78.3.3 Por lo tanto, se debe considerar como prioritaria la prevención de las causas de mortalidad más frecuentemente asociadas con este tipo de población, como la diabetes mellitus (17.1%), infartos de corazón (16.9%), enfermedades pulmonares obstructivas crónicas (5.7%), hipertensión arterial (4.7%), neumonía (3.3%) y otras causas (41.1%).1,3.

Peroxisome dynamics during development of the fungus Podospora anserina.

Peroxisomes are versatile and dynamic organelles that are required for the development of diverse eukaryotic organisms. We demonstrated previously that in the fungus Podospora anserina different peroxisomal functions are required at distinct stages of sexual development, including the initiation and progression of meiocyte (ascus) development and the differentiation and germination of sexual spores (ascospores). Peroxisome assembly during these processes relies on the differential activity of the protein machinery that drives the import of proteins into the organelle, indicating a complex developmental regulation of peroxisome formation and activity. Here we demonstrate that peroxisome dynamics is also highly regulated during development. We show that peroxisomes in P. anserina are highly dynamic and respond to metabolic and environmental cues by undergoing changes in size, morphology and number. In addition, peroxisomes of vegetative and sexual cell types are structurally different. During sexual development peroxisome number increases at two stages: at early ascus differentiation and during ascospore formation. These processes are accompanied by changes in peroxisome structure and distribution, which include a cell-polarized concentration of peroxisomes at the beginning of ascus development, as well as a morphological transition from predominantly spherical to elongated shapes at the end of the first meiotic division. Further, the mostly tubular peroxisomes present from second meiotic division to early ascospore formation again become rounded during ascospore differentiation. Ultimately the number of peroxisomes dramatically decreases upon ascospore maturation. Our results reveal a precise regulation of peroxisome dynamics during sexual development and suggest that peroxisome constitution and function during development is defined by the coordinated regulation of the proteins that control peroxisome assembly and dynamics.

Peroxisomes and sexual development in fungi.

Peroxisomes are versatile and dynamic organelles that are essential for the development of most eukaryotic organisms. In fungi, many developmental processes, such as sexual development, require the activity of peroxisomes. Sexual reproduction in fungi involves the formation of meiotic-derived sexual spores, often takes place inside multicellular fruiting bodies and requires precise coordination between the differentiation of multiple cell types and the progression of karyogamy and meiosis. Different peroxisomal functions contribute to the orchestration of this complex developmental process. Peroxisomes are required to sustain the formation of fruiting bodies and the maturation and germination of sexual spores. They facilitate the mobilization of reserve compounds via fatty acid ß-oxidation and the glyoxylate cycle, allowing the generation of energy and biosynthetic precursors. Additionally, peroxisomes are implicated in the progression of meiotic development. During meiotic development in Podospora anserina, there is a precise modulation of peroxisome assembly and dynamics. This modulation includes changes in peroxisome size, number and localization, and involves a differential activity of the protein-machinery that drives the import of proteins into peroxisomes. Furthermore, karyogamy, entry into meiosis and sorting of meiotic-derived nuclei into sexual spores all require the activity of peroxisomes. These processes rely on different peroxisomal functions and likely depend on different pathways for peroxisome assembly. Indeed, emerging studies support the existence of distinct import channels for peroxisomal proteins that contribute to different developmental stages.

A network of HMG-box transcription factors regulates sexual cycle in the fungus Podospora anserina.

High-mobility group (HMG) B proteins are eukaryotic DNA-binding proteins characterized by the HMG-box functional motif. These transcription factors play a pivotal role in global genomic functions and in the control of genes involved in specific developmental or metabolic pathways. The filamentous ascomycete Podospora anserina contains 12 HMG-box genes. Of these, four have been previously characterized; three are mating-type genes that control fertilization and development of the fruit-body, whereas the last one encodes a factor involved in mitochondrial DNA stability. Systematic deletion analysis of the eight remaining uncharacterized HMG-box genes indicated that none were essential for viability, but that seven were involved in the sexual cycle. Two HMG-box genes display striking features. PaHMG5, an ortholog of SpSte11 from Schizosaccharomyces pombe, is a pivotal activator of mating-type genes in P. anserina, whereas PaHMG9 is a repressor of several phenomena specific to the stationary phase, most notably hyphal anastomoses. Transcriptional analyses of HMG-box genes in HMG-box deletion strains indicated that PaHMG5 is at the hub of a network of several HMG-box factors that regulate mating-type genes and mating-type target genes. Genetic analyses revealed that this network also controls fertility genes that are not regulated by mating-type transcription factors. This study points to the critical role of HMG-box members in sexual reproduction in fungi, as 11 out of 12 members were involved in the sexual cycle in P. anserina. PaHMG5 and SpSte11 are conserved transcriptional regulators of mating-type genes, although P. anserina and S. pombe diverged 550 million years ago. Two HMG-box genes, SOX9 and its upstream regulator SRY, also play an important role in sex determination in mammals. The P. anserina and S. pombe mating-type genes and their upstream regulatory factor form a module of HMG-box genes analogous to the SRY/SOX9 module, revealing a commonality of sex regulation in animals and fungi.