DODAB vesicles containing lysophosphatidylcholines: The relevance of acyl chain saturation on the membrane structure and thermal properties.

The saturated LPC18:0 and unsaturated LPC18:1 lysophosphatidylcholines have important roles in inflammation and immunity and are interesting targets for immunotherapy. The synthetic cationic lipid DODAB has been successfully employed in delivery systems, and would be a suitable carrier for those lysophosphatidylcholines. Here, assemblies of DODAB and LPC18:0 or LPC18:1 were characterized by Differential Scanning Calorimetry (DSC) and Electron Paramagnetic Resonance (EPR) spectroscopy. LPC18:0 increased the DODAB gel-fluid transition enthalpy and rigidified both phases. In contrast, LPC18:1 caused a decrease in the DODAB gel-fluid transition temperature and cooperativity, associated with two populations with distinct rigidities in the gel phase. In the fluid phase, LPC18:1 increased the surface order but, differently from LPC18:0, did not affect viscosity at the membrane core. The impact of the different acyl chains of LPC18:0 and 18:1 on structure and thermotropic behavior should be considered when developing applications using mixed DODAB membranes.

Thermotropic Behavior and Structural Organization of C24:1 Sulfatide Dispersions and Its Mixtures with Cationic Bilayers.

C24:1 sulfatide (SF) is an endogenous activator of type II NKT cells. The thermotropic behavior and structure of SF dispersions and its mixtures (4.8-16.6 mol %) with cationic dioctadecyldimethylammonium bromide (DODAB) bilayers were investigated by differential scanning calorimetry and electron paramagnetic resonance spectroscopy. The non-interdigitated lamellar structures formed by pure SF display broad thermal events around 27.5 °C when heated and cooled. These events disappear upon mixing with DODAB, showing complete lipid miscibility. SF decreases the DODAB gel-phase packing, with a consequent decrease in phase-transition temperatures and cooperativity upon heating. In contrast, SF increases the rigidity of the DODAB fluid phase, resulting in a smaller decrease in transition temperatures upon cooling. The hysteresis between heating and cooling decreased as the SF molar fraction increased. These effects on DODAB are similar to the ones described for other glycolipids, such as αGalCer and ßGlcCer. This might be due to the orientation of the rigid and planar amide bond that connects their sphingoid bases and acyl chains, which result in a V-shaped conformation of the glycolipid molecules. The current results may be important to plan and develop new immunotherapeutic tools based on SF.

Assessment of the strength and electrical activity of the pelvic floor muscles of male-to-female transgender patients submitted to gender-affirming surgery: A case series.

AIMS: To assess the strength and electrical activity of the pelvic floor muscles (PFMs) of male-to-female transgender individuals submitted to gender-affirming surgery (GAS). METHODS: A case series study was conducted from October 2016 to August 2018. Transgender women, who were scheduled for GAS, participated in the study. The volunteers were submitted to a clinical evaluation of the PFM followed by digital palpation (PERFECT method) and electromyography in the preoperative, 15, and 30 days after GAS. They responded to the International Consultation on Incontinence Questionnaire-Urinary Incontinence (UI)-Short Form to evaluate the effect of UI on quality of life and to questions related to the urinary, anorectal, and sexual symptoms. Fifteen days after the GAS, patients were instructed to perform perineal exercises at home, twice a day. RESULTS: The study sample consisted of 15 transgender women with an average age of 30.6 (SD = 6.7) years. There was a decline in median strength and sustained muscle contraction duration (PERFECT), in the electrical muscle activity (RMSmean and RMSmax) between pre-GAS and 15 days after GAS (p < 0.05). However, there was an increase in these parameters between 15 and 30 days after GAS (p < 0.05). Moreover, six patients exhibited pre-GAS UI, which continued after surgery, with a worsening of urgency symptoms and improvement in nocturia and postmicturition leakage. CONCLUSION: Strength, sustained muscle contraction duration, and PFM electrical activity may decline 15 days after GAS, returning to pre-GAS values in the first month after surgery.

A Gadolinium Metal-Organic Framework Film as a Converter Layer for Neutron Detection.

Metal-organic frameworks (MOFs) are known for their versatility in terms of their crystalline structure, porosity, resistance to temperature, radiation damage, and luminescence among others. Gadolinium (Gd) is one of the elements with the highest reported cross-section for low energy neutron capture, producing internal conversion electrons and γ rays as a result of the neutron absorption. The development of Gd-BTC films (BTC=1,3,5-benzenetricarboxylate) is shown that were deposited on Si and Al substrates by airbrushing, and characterized by profilometry, Raman, EDX and X-ray diffraction. Radiation damage, thermal decomposition and neutron absorption of these films were studied as well. Gd-BTC films were attached to CMOS devices (Complementary Metal-Oxide-Semiconductor), which are sensible to the internal conversion electrons, in order to build a neutron detector. The devices Gd-BTC/CMOS could selectively detect neutrons in the presence of γ rays with a thermal neutron detection efficiency of 3.3±0.1 %, a signal to noise ratio of 6 : 1, and were suitable to obtain images.

Supramolecular organization of α-galactosylceramide in pure dispersions and in cationic DODAB bilayers.

α-galactosylceramide (α-GalCer; KRN7000) strongly stimulates NKT cells. The structures of α-GalCer assemblies and of cationic DODAB bilayers containing α-GalCer were investigated by differential scanning calorimetry (DSC) and electron spin resonance (ESR) spectroscopy. Assemblies of α-GalCer have a very tightly packed gel phase, causing spin labels to cluster and display spin exchange interactions. An endothermic phase transition is observed by DSC, leading to a fluid phase. This phase transition peak disappears upon mixing with DODAB, showing that up to 9 mol% α-GalCer is miscible with the cationic lipid. ESR spectra show that α-GalCer decreases DODAB gel phase packing, resulting in a decrease of gel-fluid transition temperature and cooperativity in DSC thermograms of mixed bilayers. In contrast, α-GalCer increases the rigidity of the fluid phase. These effects are probably due to the conformation of the rigid amide bond that connects the phytosphingosine base of α-GalCer to its long and saturated acyl chain. Possibly, α-GalCer adopts a V-shaped conformation because of the perpendicular orientation of the amide bond towards the axes of the hydrocarbon chains. Apparently, the effect of the amide bond configuration is a key structural feature for the interaction between ceramide-based glycolipids and DODAB molecules, since we have previously reported a similar decrease of gel phase packing and increase in fluid phase rigidity for DODAB bilayers containing C24:1ß-glucosylceramide. Since the structure of delivery systems is critical to the biological activity of α-GalCer, this work certainly contributes to the planning and development of novel immunotherapeutic tools.

Structural characterization of cationic DODAB bilayers containing C24:1 ß-glucosylceramide.

The effect of 5 mol%, 9 mol%, and 16 mol% of C24:1 ß-glucosylceramide (ßGlcCer) on the structure of cationic DODAB bilayers was investigated by means of differential scanning calorimetry (DSC), electron spin resonance (ESR) spectroscopy and fluorescence microscopy. ßGlcCer is completely miscible with DODAB at all fractions tested, since no domains were observed in fluorescence microscopy or ESR spectra. The latter showed that ßGlcCer destabilized the gel phase of DODAB bilayers by decreasing the gel phase packing. As a consequence, ßGlcCer induced a decrease in the phase transition temperature and cooperativity of DODAB bilayers, as seen in DSC thermograms. ESR spectra also showed that ßGlcCer induced an increase in DODAB fluid phase order and/or rigidity. Despite their different structures, a similar effect of loosening the gel phase packing and turning the fluid phase more rigid/organized has also been observed when low molar fractions of cholesterol were incorporated in DODAB bilayers. The structural characterization of mixed membranes made of cationic lipids and glucosylceramides may be important for developing novel immunotherapeutic tools such as vaccine adjuvants.

Case Report: An Acute Chikungunya Infection and a Recent Secondary Dengue Infection in a Peripartum Case in Ecuador.

Dengue virus (DENV) and chikungunya virus (CHIKV) are transmitted by the same mosquito vectors and now co-circulate in many parts of the world; however, coinfections and serial infections are not often diagnosed or reported. A 38-week pregnant woman was admitted to the hospital with a diagnosis of suspected DENV and CHIKV in southern coastal Ecuador. The pregnancy was complicated by mild polyhydramnios and fetal tachycardia, and a healthy newborn was born. The patient was positive for a recent secondary DENV infection (Immunoglobulin M and Immunoglobulin G positive) and an acute CHIKV infection (real-time reverse transcriptase polymerase chain reaction positive) (Asian genotype). The newborn was not tested for either virus. This case resulted in a benign clinical course with a favorable pregnancy outcome.

Structural insights on biologically relevant cationic membranes by ESR spectroscopy.

Cationic bilayers have been used as models to study membrane fusion, templates for polymerization and deposition of materials, carriers of nucleic acids and hydrophobic drugs, microbicidal agents and vaccine adjuvants. The versatility of these membranes depends on their structure. Electron spin resonance (ESR) spectroscopy is a powerful technique that employs hydrophobic spin labels to probe membrane structure and packing. The focus of this review is the extensive structural characterization of cationic membranes prepared with dioctadecyldimethylammonium bromide or diC14-amidine to illustrate how ESR spectroscopy can provide important structural information on bilayer thermotropic behavior, gel and fluid phases, phase coexistence, presence of bilayer interdigitation, membrane fusion and interactions with other biologically relevant molecules.

Bacterial spores as particulate carriers for gene gun delivery of plasmid DNA.

Bacillus subtilis spores represent a suitable platform for the adsorption of proteins, enzymes and viral particles at physiological conditions. In the present work, we demonstrate that purified spores can also adsorb DNA on their surface after treatment with cationic molecules. In addition, we demonstrate that DNA-coated B. subtilis spores can be used as particulate carriers and act as an alternative to gold microparticles for the biolistic (gene gun) administration of plasmid DNA in mice. Gene gun delivery of spores pre-treated with DODAB (dioctadecyldimethylammonium bromide) allowed efficient plasmid DNA absorption and induced protein expression levels similar to those obtained with gold microparticles. More importantly, we demonstrated that a DNA vaccine adsorbed on spores can be loaded into biolistic cartridges and efficiently delivered into mice, which induced specific cellular and antibody responses. Altogether, these data indicate that B. subtilis spores represent a simple and low cost alternative for the in vivo delivery of DNA vaccines by the gene gun technology.

Genetic characterization of native and invasive Plagioscion squamosissimus (Perciformes, Sciaenidae) populations in Brazilian hydrographic basins.

The genetic diversity of invasive and native populations of Plagioscion squamosissimus (Heckel, 1840) from the Paraná, Parnaiba and Araguaia-Tocantins river basins was assessed by using Random Amplified Polymorphic DNA (RAPD) markers. Genetic data confirmed the hypothesis of low genetic variability within and among P. squamosissimus populations introduced in the upper Paraná River basin, and indicated that they likely originated from a common ancestor. Moreover, the data demonstrated that, in agreement with available historical records, the P. squamosissimus populations established in the Paraná River basin were derived from a population native to the Parnaíba River basin. The genetic data presented here are of potential future application for the management of the invasive P. squamosissimus populations and for the preservation of the genetic legacy of native fish.

The effect of an oligonucleotide on the structure of cationic DODAB vesicles.

The effect of a small single-stranded oligonucleotide (ODN) on the structure of cationic DODAB vesicles was investigated by means of differential scanning calorimetry (DSC), small angle X-ray scattering (SAXS) and electron spin resonance (ESR) spectroscopy. ODN adsorption induced coalescence of vesicles and formation of multilamellar structures with close contact between lamellae. It also increased the phase transition temperature by 10 °C but decreased transition cooperativity. The ODN rigidified and stabilized the gel phase. In the fluid phase, a simultaneous decrease of ordering close to the bilayer surface and increase in bilayer core rigidity was observed in the presence of the ODN. These effects may be due not only to electrostatic shielding of DODAB head groups but also to superficial dehydration of the bilayers. The data suggest that oligonucleotides may induce the formation of a multilamellar poorly hydrated coagel-like phase below phase transition. These effects should be taken into account when planning ODN delivery employing cationic bilayer carriers.

Síndrome de Evans Fisher asociado con esclerodermia / Fisher Evans syndrome associated with scleroderma

El síndrome de Evans Fisher, descrito por primera vez en 1951, es un desorden autoinmune caracterizado por la presencia simultánea o secuencial de anemia hemolítica, trombocitopenia inmune y, en ocasiones, neutropenia inmune; con una prueba de antiglobulina directa positiva. Puede ser de causa primaria o secundaria a otras condiciones, como el lupus eritematoso sistémico, los síndromes linfoproliferativos o inmunodeficiencias primarias. Es muy rara su asociación con la esclerodermia. Con el término esclerodermia, que en sentido literal significa piel dura, se designa un grupo de enfermedades y síndromes que tienen como característica común la induración y el engrosamiento cutáneos. Se caracteriza por la presencia de un depósito excesivo de los componentes del tejido conjuntivo, expresado en forma de fibrosis hística, y por alteraciones estructurales del lecho vascular. Con un cuadro clínico muy amplio, afecta fundamentalmente la piel y ciertos órganos internos, como tubo digestivo, pulmón, corazón y riñón. Se presenta una paciente femenina de 75 años de edad, piel negra, con antecedentes de hipertensión arterial, diabetes mellitus tipo 2, cardiopatía isquémica y esclerodermia, esta última diagnosticada seis meses antes de su ingreso. Acudió por decaimiento marcado, palidez cutáneo-mucosa intensa y petequias generalizadas. En los estudios realizados se detectó anemia y trombocitopenia severas, reticulocitosis, prueba de antiglobulina directa positiva e hipercelularidad medular con hiperplasia severa de los sistemas megacariopoyético y eritropoyético. Se diagnosticó un síndrome de Evans Fisher y se trató con esteroides e inmunomoduladores; se logró la mejoría clínica y la remisión hematológica(AU)

The Evans syndrome, first described in 1951, is an autoimmune disorder characterized by the simultaneous or sequential development of hemolytic anemia and immune thrombocytopenia or immune neutropenia. It may be of primary origin or secondary to other diseases or conditions such as systemic lupus erythematosus, lymphoproliferative disorders or primary immunodeficiencies. Its association with scleroderma is considered very rare. The word scleroderma, which literally means hard skin, designates a group of diseases and syndromes of common feature in induration and thickening the skin. It is characterized by the presence of excessive deposition of connective tissue components, expressed as histic fibrosis, and structural alterations of the vascular bed. With a broad clinical view, it primarily affects the skin and certain internal organs such as gastrointestinal tract, lung, heart and kidney. We present a 75 year-old female, black skin, with a history of hypertension, type 2 diabetes, ischemic heart disease and scleroderma, the latter diagnosed six months before admission. The patient referred marked weakness, pale skin and generalized petechiae. The complete blood count detected severe anemia, thrombocytopenia and reticulocytosis. Other studies showed positive direct Coombs test and severe hypercellularity. Evans Fisher syndrome was diagnosed and treated with steroids and immunomodulators; clinical improvement and hematologic remission was achieved(AU)

Síndrome de Evans Fisher asociado con esclerodermia / Fisher Evans syndrome associated with scleroderma

El síndrome de Evans Fisher, descrito por primera vez en 1951, es un desorden autoinmune caracterizado por la presencia simultánea o secuencial de anemia hemolítica, trombocitopenia inmune y, en ocasiones, neutropenia inmune; con una prueba de antiglobulina directa positiva. Puede ser de causa primaria o secundaria a otras condiciones, como el lupus eritematoso sistémico, los síndromes linfoproliferativos o inmunodeficiencias primarias. Es muy rara su asociación con la esclerodermia. Con el término esclerodermia, que en sentido literal significa piel dura, se designa un grupo de enfermedades y síndromes que tienen como característica común la induración y el engrosamiento cutáneos. Se caracteriza por la presencia de un depósito excesivo de los componentes del tejido conjuntivo, expresado en forma de fibrosis hística, y por alteraciones estructurales del lecho vascular. Con un cuadro clínico muy amplio, afecta fundamentalmente la piel y ciertos órganos internos, como tubo digestivo, pulmón, corazón y riñón. Se presenta una paciente femenina de 75 años de edad, piel negra, con antecedentes de hipertensión arterial, diabetes mellitus tipo 2, cardiopatía isquémica y esclerodermia, esta última diagnosticada seis meses antes de su ingreso. Acudió por decaimiento marcado, palidez cutáneo-mucosa intensa y petequias generalizadas. En los estudios realizados se detectó anemia y trombocitopenia severas, reticulocitosis, prueba de antiglobulina directa positiva e hipercelularidad medular con hiperplasia severa de los sistemas megacariopoyético y eritropoyético. Se diagnosticó un síndrome de Evans Fisher y se trató con esteroides e inmunomoduladores; se logró la mejoría clínica y la remisión hematológica

The Evans syndrome, first described in 1951, is an autoimmune disorder characterized by the simultaneous or sequential development of hemolytic anemia and immune thrombocytopenia or immune neutropenia. It may be of primary origin or secondary to other diseases or conditions such as systemic lupus erythematosus, lymphoproliferative disorders or primary immunodeficiencies. Its association with scleroderma is considered very rare. The word scleroderma, which literally means hard skin, designates a group of diseases and syndromes of common feature in induration and thickening the skin. It is characterized by the presence of excessive deposition of connective tissue components, expressed as histic fibrosis, and structural alterations of the vascular bed. With a broad clinical view, it primarily affects the skin and certain internal organs such as gastrointestinal tract, lung, heart and kidney. We present a 75 year-old female, black skin, with a history of hypertension, type 2 diabetes, ischemic heart disease and scleroderma, the latter diagnosed six months before admission. The patient referred marked weakness, pale skin and generalized petechiae. The complete blood count detected severe anemia, thrombocytopenia and reticulocytosis. Other studies showed positive direct Coombs test and severe hypercellularity. Evans Fisher syndrome was diagnosed and treated with steroids and immunomodulators; clinical improvement and hematologic remission was achieved

Oligonucleotide adsorption affects phase transition but not interdigitation of diC14-amidine bilayers.

In this work, we investigate the effect of a small single-stranded oligonucleotide (ODN) on the colloid stability and structure of cationic diC14-amidine liposomes. Dynamic light scattering (DLS) shows that small, stable, anionic assemblies are formed in presence of excess ODN negative charge. This charge overcompensation condition was further characterized. A less cooperative bilayer phase transition is observed by differential scanning calorimetry (DSC). Electron spin resonance (ESR) spectra of probes at different bilayer depths show that ODN electrostatic adsorption increases the rigidity of both interdigitated gel and lamellar fluid phases. The increase in gel phase rigidity could be explained by the transformation of an adjacent to an interpenetrated interdigitation. Interdigitated fusogenic bilayers may find interesting applications in delivery of therapeutic oligonucleotides.

Genetic divergence among invasive and native populations of Plagioscion squamosissimus (Perciformes, Sciaenidae) in Neotropical regions.

The genetic divergence among invasive and native populations of Plagioscion squamosissimus from four Neotropical hydrographic basins was assessed using the hypervariable domain of the mitochondrial DNA (mtDNA) control region. Plagioscion squamosissimus is native to the neighbouring hydrographic basins of the Parnaíba and Amazon Rivers, and the latter includes the Araguaia-Tocantins drainage, but it is invasive in other basins due to introductions. The mtDNA nucleotide polymorphism supported the hypothesis that the Amazon and Parnaíba populations constitute the same species and are separated into two independent evolutionary lineages. Absence of nucleotide polymorphism was observed within and among P. squamosissimus populations invasive to the uppper and middle Paraná River basins. Nucleotide divergence was null or low comparing the Paraná invasive populations with the populations native to the Parnaíba River basin, whereas it was significantly high compared to Tocantins populations. These results ascertain that P. squamosissimus populations invasive to the upper Paraná River basin and to the middle Paraná River basin downstream of the Itaipu dam are derived from the Parnaíba River basin. The genetic data presented are potentially useful to assist further studies on P. squamosissimus taxonomic and geographic distribution, development of ecological guidelines for managing populations invasive to the upper Paraná River basin and for preservation of native fish diversity.

Mitochondrial D-loop nucleotide diversity in Astyanax (Osteichthyes, Characidae) from the upper Paraná and upper Paraguay River basins.

The morphological discrimination between the species Astyanax altiparanae and A. asuncionensis of the upper Paraná River and Paraguay River basins, respectively, has always been difficult. Two D-loop haplogroups of A. altiparanae are known, one with the presence (AltoPR) or the absence (AltoPR-D) of a 32-bp block similar to that in A. asuncionensis. We examined these samples to characterize A. altiparanae and verify whether A. asuncionensis occurred in the upper Paraná River prior to the submergence of the Sete Quedas Falls when Itaipu reservoir was impounded. D-loop sequences were analyzed in A. altiparanae of the upper Paraná and Iguaçu Rivers and those of A. asuncionensis of the upper Paraguay River. The haplogroup AltoPR was found at all sites of the upper Paraná and Iguaçu Rivers, whereas AltoPR-D occurred in the Itaipu reservoir, floodplain and in the Tietê and Grande Rivers. Two haplogroups of A. asuncionensis were identified and both did not have the 32-bp block. However, AltoPR and AltoPR-D differed from one another in 5.1% of their bases and between 8.9 and 12.5% with regard to the haplogroups of the upper Paraguay basin. Further, AltoPR-D occurred in the Grande River upstream the Marimbondo Falls and other older reservoirs than Itaipu. The results reject the hypothesis of the establishment of A. asuncionensis and suggest that the haplogroup AltoPR-D existed in the upper Paraná River before the impounding of the Itaipu reservoir. Moreover, morphological similarity and high genetic variation within the altiparanae/asuncionensis group suggest the existence of a cryptic species complex.

Stable assemblies of cationic bilayer fragments and CpG oligonucleotide with enhanced immunoadjuvant activity in vivo.

The cationic lipid dioctadecyldimethylammonium bromide (DODAB) and the CpG oligonucleotide (CpG) have been separately used as potent immunoadjuvants driving Th1 responses. Here DODAB bilayer fragments (BF) and CpG (5'-TTGACGTTCG-3') assemblies have their physical properties and immunoadjuvant activity determined using ovalbumin (OVA) as a model antigen. At 0.1 mg/mL OVA, the dependence of DODAB BF/OVA size and zeta-potential on time and [DODAB] establishes 0.1 mM DODAB as suitable for obtaining stable and cationic DODAB BF/OVA assemblies. At 0.1 mM DODAB, 0.1 mg/mL OVA and 0.006 mM CpG, the zeta-potential is zero. At [CpG]>0.006 mM, good colloidal stability for the anionic assemblies is due to charge overcompensation. At 0.020 mM CpG, these DODAB BF/OVA/CpG assemblies are highly effective in vivo generating responses similar to those elicited by the stable and cationic DODAB BF/OVA. The anti-OVA DTH reaction and the secretion of IFN-gamma and IL-12 are 6, 42 and 9 times larger for the DODAB BF/OVA/CpG-immunized mice than the same responses by OVA-immunized mice, respectively. This work shows for the first time that charge of small assemblies is not important to determine the immune response.

Impacto financiero de la emigración de médicos y enfermeras del área Andina: un ejercicio de consolidación de documentos país / Financial impact of emigration of doctors and nurses from the Andean area: an exercise to consolidate country documents

El presente documento consolida los resultados del estimado del costo económico de la emigración de médicos y enfermeras en los últimos años en los países del área andina. Dicho consolidado supuso, inicialmente, la identificación de una metodología que validada para el caso del Perú luego fue aplicada en el conjunto de países señalados. Este texto al igual que los documentos específicos a cada país, aborda el problema específico de la migración internacional de los Recursos Humanos de la Salud (RHUS) en el marco más amplio del actual fenómeno mundial de la globalización de la mano de obra. Las cifras actuales de movilización internacional de la mano de obra evidencian que existe una profunda necesidad de los países más desarrollados por incorporar mano de obra. Ello es así como consecuencia de los cambios en la pirámide demográfica de los países desarrollados donde la cúspide es tan igual o importante que el resto de grupos etarios, requiriendo fuerza laboral joven para atender a una población cada vez de mayor edad ya sea a través de la provisión de los servicios de salud como también a través del aporte previsional a los sistemas de seguridad social públicos. De esta manera, los sistemas de reclutamiento de RHUS aparecen como un mecanismo internacional importante para la captación de los servicios de salud que requieren los países desarrollados, aunque no necesariamente ellos cubren a la totalidad de los migrantes profesionales de la salud. (AU)