Lipidomic scanning of self-lipids identifies headless antigens for natural killer T cells.

To broadly measure the spectrum of cellular self-antigens for natural killer T cells (NKT), we developed a sensitive lipidomics system to analyze lipids trapped between CD1d and NKT T cell receptors (TCRs). We captured diverse antigen complexes formed in cells from natural endogenous lipids, with or without inducing endoplasmic reticulum (ER) stress. After separating protein complexes with no, low, or high CD1d-TCR interaction, we eluted lipids to establish the spectrum of self-lipids that facilitate this interaction. Although this unbiased approach identified fifteen molecules, they clustered into only two related groups: previously known phospholipid antigens and unexpected neutral lipid antigens. Mass spectrometry studies identified the neutral lipids as ceramides, deoxyceramides, and diacylglycerols, which can be considered headless lipids because they lack polar headgroups that usually form the TCR epitope. The crystal structure of the TCR-ceramide-CD1d complex showed how the missing headgroup allowed the TCR to predominantly contact CD1d, supporting a model of CD1d autoreactivity. Ceramide and related headless antigens mediated physiological TCR binding affinity, weak NKT cell responses, and tetramer binding to polyclonal human and mouse NKT cells. Ceramide and sphingomyelin are oppositely regulated components of the "sphingomyelin cycle" that are altered during apoptosis, transformation, and ER stress. Thus, the unique molecular link of ceramide to NKT cell response, along with the recent identification of sphingomyelin blockers of NKT cell activation, provide two mutually reinforcing links for NKT cell response to sterile cellular stress conditions.

mRNA lipid nanoparticles expressing cell-surface cleavage independent HIV Env trimers elicit autologous tier-2 neutralizing antibodies.

The HIV-1 envelope glycoprotein (Env) is the sole neutralizing determinant on the surface of the virus. The Env gp120 and gp41 subunits mediate receptor binding and membrane fusion and are generated from the gp160 precursor by cellular furins. This cleavage event is required for viral entry. One approach to generate HIV-1 neutralizing antibodies following immunization is to express membrane-bound Env anchored on the cell-surface by genetic means using the natural HIV gp41 transmembrane (TM) spanning domain. To simplify the process of Env trimer membrane expression we sought to remove the need for Env precursor cleavage while maintaining native-like conformation following genetic expression. To accomplish these objectives, we selected our previously developed 'native flexibly linked' (NFL) stabilized soluble trimers that are both near-native in conformation and cleavage-independent. We genetically fused the NFL construct to the HIV TM domain by using a short linker or by restoring the native membrane external proximal region, absent in soluble trimers, to express the full HIV Env ectodomain on the plasma membrane. Both forms of cell-surface NFL trimers, without and with the MPER, displayed favorable antigenic profiles by flow cytometry when expressed from plasmid DNA or mRNA. These results were consistent with the presence of well-ordered cell surface native-like trimeric Env, a necessary requirement to generate neutralizing antibodies by vaccination. Inoculation of rabbits with mRNA lipid nanoparticles (LNP) expressing membrane-bound stabilized HIV Env NFL trimers generated tier 2 neutralizing antibody serum titers in immunized animals. Multiple inoculations of mRNA LNPs generated similar neutralizing antibody titers compared to immunizations of matched NFL soluble proteins in adjuvant. Given the recent success of mRNA vaccines to prevent severe COVID, these are important developments for genetic expression of native-like HIV Env trimers in animals and potentially in humans.

Lipid matrix-specific pretreatment method for enhancing the extractability and allergenicity maintenance of bovine milk allergens in ELISA detection.

The presence of various components in the food matrix makes allergen detection difficult and inaccurate, and pretreatment is an innovative breakthrough point. Food matrices were categorised based on their composition. Subsequently, a pretreatment method was established using a combination of ultrasound-assisted n-hexane degreasing and weakly alkaline extraction systems to enhance the detection accuracy of bovine milk allergens. Results showed that more allergens were obtained with less structural destruction, as demonstrated using immunological quantification and spectral analysis. Concurrently, allergenicity preservation was confirmed through liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis, a KU812 cell degranulation model, and western blotting. The method exhibited good accuracy (bias, 8.47%), repeatability (RSDr, 1.52%), and stability (RSDR, 5.65%). In foods with high lipid content, such as chocolate, the allergen content was 2.29-fold higher than that of commercial kits. Laser confocal scanning microscopy (LCSM) and scanning electron microscopy (SEM) analyses revealed a significant decrease in fat content after post-pretreatment using our method. In addition, colloidal stability surpassed that achieved using commercial kits, as indicated through the PSA and zeta potential results. The results demonstrated the superiority of the extractability and allergenicity maintenance of lipid matrix-specific pretreatment methods for improving the accuracy of ELISA based allergen detection in real food.

mRNA-LNP prime boost evolves precursors toward VRC01-like broadly neutralizing antibodies in preclinical humanized mouse models.

Germline-targeting (GT) protein immunogens to induce VRC01-class broadly neutralizing antibodies (bnAbs) to the CD4-binding site of the HIV envelope (Env) have shown promise in clinical trials. Here, we preclinically validated a lipid nanoparticle-encapsulated nucleoside mRNA (mRNA-LNP) encoding eOD-GT8 60mer as a soluble self-assembling nanoparticle in mouse models. In a model with three humanized B cell lineages bearing distinct VRC01-precursor B cell receptors (BCRs) with similar affinities for eOD-GT8, all lineages could be simultaneously primed and undergo diversification and affinity maturation without exclusionary competition. Boosts drove precursor B cell participation in germinal centers; the accumulation of somatic hypermutations, including in key VRC01-class positions; and affinity maturation to boost and native-like antigens in two of the three precursor lineages. We have preclinically validated a prime-boost regimen of soluble self-assembling nanoparticles encoded by mRNA-LNP, demonstrating that multiple lineages can be primed, boosted, and diversified along the bnAb pathway.

Cellular and Molecular Effects of Microgravity on the Immune System: A Focus on Bioactive Lipids.

Microgravity is one of the main stressors that astronauts are exposed to during space missions. This condition has been linked to many disorders, including those that feature dysfunctional immune homeostasis and inflammatory damage. Over the past 30 years, a significant body of work has been gathered connecting weightlessness-either authentic or simulated-to an inefficient reaction to pathogens, dysfunctional production of cytokines and impaired survival of immune cells. These processes are also orchestrated by a plethora of bioactive lipids, produced by virtually all cells involved in immune events, which control the induction, magnitude, outcome, compartmentalization and trafficking of immunocytes during the response to injury. Despite their crucial importance in inflammation and its modulation, however, data concerning the role of bioactive lipids in microgravity-induced immune dysfunctions are surprisingly scarce, both in quantity and in variety, and the vast majority of it focuses on two lipid classes, namely eicosanoids and endocannabinoids. The present review aims to outline the accumulated knowledge addressing the effects elicited by microgravity-both simulated and authentic-on the metabolism and signaling of these two prominent lipid groups in the context of immune and inflammatory homeostasis.

SMART-lipid nanoparticles enabled mRNA vaccine elicits cross-reactive humoral responses against the omicron sub-variants.

The continual emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants has necessitated the development of broad cross-reactive vaccines. Recent findings suggest that enhanced antigen presentation could lead to cross-reactive humoral responses against the emerging variants. Toward enhancing the antigen presentation to dendritic cells (DCs), we developed a novel shikimoylated mannose receptor targeting lipid nanoparticle (SMART-LNP) system that could effectively deliver mRNAs into DCs. To improve the translation of mRNA, we developed spike domain-based trimeric S1 (TS1) mRNA with optimized codon sequence, base modification, and engineered 5' and 3' UTRs. In a mouse model, SMART-LNP-TS1 vaccine could elicit robust broad cross-reactive IgGs against Omicron sub-variants, and induced interferon-γ-producing T cells against SARS-CoV-2 virus compared with non-targeted LNP-TS1 vaccine. Further, T cells analysis revealed that SMART-LNP-TS1 vaccine induced long-lived memory T cell subsets, T helper 1 (Th1)-dominant and cytotoxic T cells immune responses against the SARS-CoV-2 virus. Importantly, SMART-LNP-TS1 vaccine produced strong Th1-predominant humoral and cellular immune responses. Overall, SMART-LNPs can be explored for precise antigenic mRNA delivery and robust immune responses. This platform technology can be explored further as a next-generation delivery system for mRNA-based immune therapies.

Antibody response in silver catfish (Rhamdia quelen) immunized with a model antigen associated with different adjuvants

Adjuvants are essential to boost the immune response to inoculated antigen and play a central role in vaccine development. In this study, we investigated the efficacy of several adjuvants in the production of anti-bovine serum albumin (BSA) antibodies in silver catfish. Two hundred and seventy juvenile silver catfish (60–80 g) of both sexes were intraperitoneally vaccinated with BSA (200 µg/fish) alone or mixed to the following adjuvants: Freund’s complete adjuvant (FCA), Freund’s incomplete adjuvant (FIA), aluminum hydroxide (AlOH), Montanide, four types of cytosine-phosphate-guanine (CpG) oligodeoxynucleotides (ODNs) and three concentrations of β-glucan, and the immune enhancing property was evaluated by measuring anti-BSA antibodies in blood samples at biweekly intervals. Our results demonstrated that CpGs ODNs and β-glucan were as effective as classical adjuvants (FCA, FIA, AlOH and Montanide) in promoting anti-BSA antibodies and that the kinetics of antibody production induced by all adjuvants used in our study had a similar trend to that observed in other fish species, with a peak at 28 days post-vaccination. These results may be useful for the selection of adjuvants for vaccine formulation intended for silver catfish and for the development of vaccine and vaccination strategies to other fish species.

Seroconversión frente a primovacunación reforzada contra hepatitis B en niños con cáncer / Seroconversion in response to a reinforced primary hepatitis B vaccination in children with cancer

Introducción: La respuesta inmune a los antígenos de las vacunas está disminuida en los niños con cáncer. El objetivo de este estudio fue evaluar la seroconversión frente a vacuna ADN recombinante contra hepatitis B al momento del inicio de la quimioterapia y/o remisión en niños con cáncer. Pacientes y método: Estudio prospectivo, bicéntrico, controlado, no aleatorizado de niños con diagnóstico reciente de cáncer pareados con niños sanos. Los casos fueron vacunados a tiempo 0, 1 y 6 meses, a dosis de 20 y 40 μg si eran < ó > 10 años, respectivamente, con vacuna ADN recombinante contra hepatitis B, en el momento del diagnóstico en el caso de los tumores sólidos y luego de la remisión en el caso de los tumores hematológicos. El grupo control recibió el mismo esquema, con dosis de 10 o 20 μg respectivamente. Se midieron anticuerpos séricos anti-HBs a los 2, 8 y 12 meses posvacunación. Seroconversión se definió como títulos anti-HBs > 10 mUI/ml al octavo mes. Resultados: Un total de 78 niños con cáncer y 25 controles fueron evaluados con títulos anti-HBs al octavo mes. La tasa de seroconversión fue de 26,9%, en niños con cáncer, sin diferencia por edad, género ni tipo de tumor (p = 0,13; 0,29; y 0,44, respectivamente), y de 100% en el grupo control (p < 0,0001, comparado con los niños con cáncer). En el seguimiento a los 12 meses solo el 31,9% de los niños con cáncer presentaba títulos anti-HBs > 10 mUI/ml. Conclusiones: La vacunación contra hepatitis B con vacuna ADN recombinante, con esquema reforzado de 3 dosis, en el momento del inicio de la quimioterapia y/o remisión provee una respuesta inmune insuficiente en la mayoría de los niños con cáncer. En esta población debieran evaluarse vacunas de tercera generación, con adyuvantes más inmunogénicos, esquemas reforzados a los 0, 1, 2 y 6 meses, medición de títulos de anticuerpos al octavo y duodécimo mes, eventual uso de refuerzos y reevaluación de inmunogenicidad si correspondiese.

Introduction: Immune response against vaccine antigens may be impaired in children with cancer. The aim of this study was to evaluate the seroconversion response against hepatitis B vaccination (HBV) at the time of chemotherapy onset and/or remission in children with cancer. Patients and method: Prospective, two-centre, controlled, non-randomised study conducted on children recently diagnosed with cancer, paired with healthy subjects. Cases received HBV at time 0, 1 and 6 months with DNA recombinant HBV at a dose of 20 and 40 μg if < or > than 10 years of age, respectively, at the time of diagnosis for solids tumours and after the remission in case of haematological tumours. Controls received the same schedule, but at of 10 and 20 μg doses, respectively. HBs antibodies were measured in serum samples obtained at 2, 8 and 12 months post-vaccination. Protective titres were defined as > 10 mIU/ml at 8th month of follow up. Results: A total of 78 children with cancer and 25 healthy controls were analysed at month 8th of follow up. Seroconversion rates in the cancer group reached 26.9%, with no differences by age, gender or type of tumour (P = .13, .29, and .44, respectively). Control group seroconversion was 100% at the 8th month, with P < .0001 compared with the cancer group. At month 12 of follow up, just 31.9% of children with cancer achieved anti-HBs antibodies > 10 mIU/ml. Conclusions: Vaccination against hepatitis B with three doses of DNA recombinant vaccine at an increased concentration, administrated at the time of onset of chemotherapy and/or remission provided an insufficient immune response in a majority of children with cancer. More immunogenic vaccines should be evaluated in this special population, such as a third generation, with more immunogenic adjuvants, enhanced schedules at 0, 1, 2, 6 month, evaluation of antibody titres at month 8 and 12 h to evaluate the need for further booster doses.

Assessment of nursing care using indicators generated by software / Avaliação da assistência de enfermagem utilizando indicadores gerados por um software / Evaluación de la asistencia de enfermería utilizando indicadores generados por un software

OBJECTIVE: to analyze the efficacy of the Nursing Process in an Intensive Care Unit using indicators generated by software. METHOD: cross-sectional study using data collected for four months. RNs and students daily registered patients, took history (at admission), performed physical assessments, and established nursing diagnoses, nursing plans/prescriptions, and assessed care delivered to 17 patients using software. Indicators concerning the incidence and prevalence of nursing diagnoses, rate of effectiveness, risk diagnoses, and rate of effective prevention of complications were computed. RESULTS: the Risk for imbalanced body temperature was the most frequent diagnosis (23.53%), while the least frequent was Risk for constipation (0%). The Risk for Impaired skin integrity was prevalent in 100% of the patients, while Risk for acute confusion was the least prevalent (11.76%). Risk for constipation and Risk for impaired skin integrity obtained a rate of risk diagnostic effectiveness of 100%. The rate of effective prevention of acute confusion and falls was 100%. CONCLUSION: the efficacy of the Nursing Process using indicators was analyzed because these indicators reveal how nurses have identified patients' risks and conditions, and planned care in a systematized manner. .

OBJETIVO: analisar a eficácia do Processo de Enfermagem em uma Unidade de Terapia Intensiva, utilizando indicadores gerados por um software. MÉTODO: estudo transversal, cujos dados foram coletados durante quatro meses. Enfermeiros e acadêmicos realizaram, diariamente, cadastro e anamnese (na admissão), exame físico, diagnósticos de enfermagem, planejamento/prescrição de enfermagem e avaliação da assistência de 17 pacientes, utilizando um software. Calculou-se os indicadores incidência e prevalência de diagnósticos de enfermagem, taxa de efetividade diagnóstica de risco e taxa de efetividade na prevenção de complicações. RESULTADOS: o Risco de desequilíbrio na temperatura corporal foi o diagnóstico mais incidente (23,53%) e o menos incidente foi o Risco de constipação (0%). O Risco de integridade da pele prejudicada foi prevalente em 100% dos pacientes, enquanto o Risco de confusão aguda foi o menos prevalente (11,76%). Risco de constipação e Risco de integridade da pele prejudicada obtiveram taxa de efetividade diagnóstica de risco de 100%. A taxa de efetividade na prevenção de confusão aguda e de queda foi de 100%. CONCLUSÃO: analisou-se a eficácia do Processo de Enfermagem utilizando indicadores, pois retratam como o enfermeiro tem identificado os problemas e riscos do paciente, e planejado a assistência de forma sistematizada. .

OBJETIVO: analizar la eficacia del Proceso de Enfermería en una Unidad de Terapia Intensiva, utilizando indicadores generados por un software. MÉTODO: estudio transversal, cuyos datos fueron recolectados durante cuatro meses. Enfermeros y académicos realizaron, diariamente, registro y anamnesis (en la admisión), examen físico, diagnósticos de enfermería, planificación/prescripción de enfermería y evaluación de la asistencia en 17 pacientes, utilizando un software. Se calculó los indicadores incidencia y prevalencia de diagnósticos de enfermería, la tasa de efectividad diagnóstica de riesgo y la tasa de efectividad en la prevención de complicaciones. RESULTADOS: el Riesgo de desequilibrio en la temperatura corporal fue el diagnóstico más prevalente (23,53%) y el menos prevalente fue el Riesgo de constipación (0%). El Riesgo de integridad de la piel perjudicada fue prevalente en 100% de los pacientes, en cuanto el Riesgo de confusión aguda fue el menos prevalente (11,76%). El Riesgo de constipación y el Riesgo de integridad de la piel perjudicada obtuvieron una tasa de efectividad diagnóstica de riesgo de 100%. La tasa de efectividad en la prevención de confusión aguda y de caída fue de 100%. CONCLUSIÓN: se analizó la eficacia del Proceso de Enfermería utilizando indicadores, ya que retratan cómo el enfermero ha identificado los problemas y riesgos del paciente, y planificado la asistencia de forma sistematizada. .

Deciphering the contribution of lipid droplets in leprosy: multifunctional organelles with roles in Mycobacterium leprae pathogenesis

Leprosy is an infectious disease caused by Mycobacterium leprae that affects the skin and nerves, presenting a singular clinical picture. Across the leprosy spectrum, lepromatous leprosy (LL) exhibits a classical hallmark: the presence of a collection of M. leprae-infected foamy macrophages/Schwann cells characterised by their high lipid content. The significance of this foamy aspect in mycobacterial infections has garnered renewed attention in leprosy due to the recent observation that the foamy aspect represents cells enriched in lipid droplets (LD) (also known as lipid bodies). Here, we discuss the contemporary view of LD as highly regulated organelles with key functions in M. leprae persistence in the LL end of the spectrum. The modern methods of studying this ancient disease have contributed to recent findings that describe M. leprae-triggered LD biogenesis and recruitment as effective mycobacterial intracellular strategies for acquiring lipids, sheltering and/or dampening the immune response and favouring bacterial survival, likely representing a fundamental aspect of M. leprae pathogenesis. The multifaceted functions attributed to the LD in leprosy may contribute to the development of new strategies for adjunctive anti-leprosy therapies.

Effect of lipoarabinomannan from Mycobacterium avium subsp avium in Freund’s incomplete adjuvant on the immune response of cattle

The aim of the present study was to determine whether lipoarabinomannan (LAM), in combination with Freund’s incomplete adjuvant (FIA), was able to improve cell-mediated and antibody-mediated immune responses against ovalbumin (OVA) in cattle. Twenty-three calves were assigned to four treatment groups, which were subcutaneously immunized with either OVA plus FIA, OVA plus FIA and LAM from Mycobacterium avium subsp avium, FIA plus LAM, or FIA alone. Lymphoproliferation, IFN-γ production and cell subpopulations on peripheral blood mononuclear cells before and 15 days after treatment were evaluated. Delayed hypersensitivity was evaluated on day 57. Specific humoral immune response was measured by ELISA. Inoculation with LAM induced higher levels of lymphoproliferation and IFN-γ production in response to ConA and OVA (P < 0.05). Specific antibody titers were similar in both OVA-immunized groups. Interestingly, our results showed that the use of LAM in vaccine preparations improved specific cell immune response evaluated by lymphoproliferation and IFN-γ production by at least 50 and 25 percent, respectively, in cattle without interfering with tuberculosis and paratuberculosis diagnosis.

Análise da relação de qualidade da dieta com nível de atividade física e destes com perfil lipídico e estado inflamatório em indivíduos de risco cardiometabólico / Analysis of the relationship between diet quality and physical activity level and these with lipid profile and inflammatory status in individuals at high cardiometabolic risk

Introdução: Baixo nível de atividade física (AF) associado ao alto consumo energético contribuíram para transição nutricional no Brasil. Estilo de vida saudável reverte em benefícios cardiometabólicos. Considerando que estado inflamatório subclínico media os danos ao sistema cardiovascular, é possível que hábitos de vida saudáveis melhorem os fatores de risco, via atenuação da inflamação. Instrumentos padronizados para medir qualidade da dieta e AF estão disponíveis, mas não estudos locais avaliando a relação destes fatores entre si com base nestes instrumentos, ou examinando suas associações com estado inflamatório e perfil lipídico. Objetivos: Este estudo avaliou a associação entre a versão brasileira do Healthy Eating Index (B-HEI) e nível de AF e destes com marcadores inflamatórios, índice de resistência à insulina e variáveis lipídicas em indivíduos com alto risco cardiometabólico. Métodos: Nesta análise transversal foram incluídos 204 participantes (64,7 por cento mulheres; média de idade de 54,1 anos) de Estudo de Prevenção de Diabetes do CSEscola da FSP-USP, com pré-diabetes ou de síndrome metabólica sem diabetes. Foram realizados questionários e coletas de sangue. Foram utilizados três recordatórios alimentares de 24h para obtenção do B-HEI. O nível de AF foi medido pela versão longa do IPAQ, sendo determinada a AF no lazer, na locomoção, AF total e tempo de TV. Coeficiente de Spearman foi empregado para testar correlações. Para avaliar a relação entre o B-HEI e AF e dos tercis destas variáveis com marcadores inflamatórios e HOMA-IR foi usada ANOVA. Para avaliar associações independentes do B-HEI, tendo como variáveis dependentes parâmetros lipídicos, inflamatórios ou HOMA-IR, usou-se regressão linear múltipla e, para associações independentes da AF como as mesmas variáveis, usou-se regressão logística, sendo obtidos odds ratios (OR) e p de tendência. Resultados: Nos tercis do B-HEI, o nível de AF não diferiu; à medida que melhorava a qualidade da dieta houve tendência à redução do tempo de TV (21,4±11,6; 20,5±11,5; 16,8±10,4 h/sem; p=0,09). Na regressão linear, a circunferência abdominal associou-se inversamente aos escores de B-HEI, mantendo-se marginalmente significante após ajuste para idade e sexo. No mesmo modelo, proteína C reativa associou-se negativamente ao índice (p=0.02). Concentrações de adiponectina apresentaram significância marginal na análise sem ajustes (p=0.06).

Obtención y caracterización parcial de un extracto lipídico de la membrana externa de Mycobacterium smegmatis / Obtainment and partial characterization of a lipidic fragment of the outer membrane of Mycobacterium smegmatis

En la actualidad, los antígenos lipídicos de las micobacterias constituyen blancos atractivos para el desarrollo de nuevas formulaciones vacunales contra la tuberculosis. En nuestro trabajo se realizó la caracterización parcial de un extracto lipídico de pared celular de Mycobacterium smegmatis mediante cromatografía de capa delgada y Dot blot frente a gammaglobulina humana. Se identificó, fundamentalmente, la presencia de fosfolípidos y ßcidos micólicos en el extracto lipídico y se observó un elevado reconocimiento de los mismos por la gammaglobulina humana, lo cual indica la importancia de continuar los estudios de inmunoprotección empleando antígenos lipídicos de micobacterias(AU)

Currently, lipid antigens of mycobacteria are attractive targets for the development of new tuberculosis vaccinal formulations. A lipid extract of Mycobacterium smegmatis cell wall was characterized using a Thin Layer Chromatography and Dot blot with human gammaglobulin. Mainly we identified the presence of phospholipids and micolic acids in the lipid extract showing a high recognition by human gammaglobulin. These results indicate the relevance of continuing immunoprotection studies with mycobacterial lipid antigens(AU)

La infección de hepatocitos de rata en cultivo con adenovirus recombinantes causa un drástico descenso en la secreción de lipoproteínas de muy baja densidad / Recombinant adenoviral infection of rat hepatocyte cultures dramatically decreases very low-density lipoprotein secretion

Introducción. Tras su administración sistémica, los adenovirus recombinantes se concentran en el hígado, lo que les validaría para la transferencia génica a este órgano, pero existen efectos colaterales. En este trabajo se ha analizado el impacto de la infección sobre la cantidad y composición de las lipoproteínas de muy baja densidad (VLDL) secretadas en hepatocitos de rata en cultivo. Métodos. Se generaron 2 vectores adenovirales, con ADNc en dirección sentido o antisentido, ambos con capacidad infectiva pero no de propagación. Se infectaron cultivos de hepatocitos de rata con una dosis no citotóxica y se analizaron las VLDL secretadas durante los 3 períodos de 24 h posteriores a la infección y el contenido en lípidos del citosol. Resultados. La infección causó un moderado descenso en la secreción de apo B48 y de éster de colesterol durante las primeras 24 h, pero posteriormente se redujo drásticamente la secreción de partículas con apo B48 y apo B100 y su contenido en lípidos. Además, modificó sus proporciones, aumentando el porcentaje de colesterol libre a costa del esterificado, que llegó a ser indetectable. La menor secreción de VLDL no conllevó una acumulación de lípido intracelular e, incluso, descendió la masa citosólica de éster de colesterol. Conclusión. La infección con adenovirus reduce la secreción hepatocitaria de VLDL y su porcentaje de colesterol esterificado y, a diferencia de otros virus, estas acciones no parecen ir acompañadas de esteatosis hepatocelular (AU)

Introduction. After systemic administration, recombinant adenoviruses are rapidly concentrated in the liver, making them good candidates for gene transfer to this organ. However, there are collateral effects. In this study, we analyzed the effect of adenoviral infection on the number and composition of very low-density lipoproteins (VLDL) secreted by cultured rat hepatocytes. Methods. Two recombinant adenoviruses were developed, each containing cDNA in sense or antisense orientation, and with infective but not propagating ability. Cultured rat hepatocytes were infected with a subcytotoxic adenoviral dose. Secretion of VLDL particles during 3 consecutive 24 h-periods after infection and cytosolic lipid content were characterized. Results. During the first 24 h period, apo B48 and cholesteryl ester secretion moderately decreased. However, in longer incubations, infection dramatically reduced both apo B48 and apo B100 secretion, as well as VLDL lipid content. Lipid proportion was also modified: free cholesterol increased while cholesteryl ester decreased to undetectable levels. Decreased VLDL secretion was not associated with intracellular lipid accumulation; indeed, cholesteryl ester mass was even lower than in noninfected cells. Conclusion. Adenovirus infection causes hepatocytes to secrete less VLDL and to reduce their cholesteryl ester percentage. In contrast with the effects of other viruses, these effects are not accompanied by hepatocellular steatosis (AU)

Retinoides: realidad y reto para la dermatología / Retinoids: reality and challenge for the dermatology

Los Retinoides conforman una clase de compuestos de gran interés farmacéutico por ser potentes inductores de la diferenciación e inhibidores de la proliferación en células normales y neoplásicas; reducen la inflamación y potencian el sistema inmunitario. Así mismo, han demostrado ser eficaces por vía tópica en desórdenes de la queratínización y en el tratamiento y prevención de enfermedades cutáneas malignas, acné, psoriasis y fotoenvejecimiento. Se revisan los nuevos mecanismos moleculares que controlan la expresión genética, así como sus acciones inmunomoduladora e inductora de la apoptosis, que se relacionan estrechamente con sus efectos terapéuticos. Se trata, por tanto, de un trabajo de revisión sobre un tema de plena actualidad e interés como es el grupo de los Retinoides, sus propiedades, mecanismos de acción y, muy especialmente, sus aplicaciones terapéuticas, orientadas con preferencia, al ámbito dermatológico; se reflejan también, otros aspectos relacionados con el ácido retinoico y sus derivados (AU)

Evidencias experimentales sobre la naturaleza glicolipídica de los antigenos reconocidos por los anticuerpos antiislotes pancreaticos / Experimental evidence on the glycolipidic nature of antigens identified by pancreatic islet cell antibodies

Se extrajeron glicolípidos de páncreas humano adulto y fetal, con una mezcla de cloroformo, metanol y agua. Se obtuvieron por partición de Folch, y se lograron 4 extractos de páncreas adulto y 1 fetal. Las 5 fases superiores de cada uno presentaron la habilidad de bloquear la reacción del ICA frente a secciones congeladas de páncreas humano, con efecto bloqueador dosis-dependiente. El TLC-ELISA de las fracciones glicolípidicas ácidas de páncreas adulto y fetal con sueros ICA+ aportaron reacciones específicas con 2 glicolípidos: 1 de ellos migraba con el frente del solvente (SGI) y otro (SG2) mostró una movilidad en TLC entre los gangliósidos GM2 y GM1 estándares. Ninguno presentó características de gangliósidos. Los sueros ICA+ reaccionaron TLC-ELISA con diferentes glicolípidos sulfatados. Se estudió la prevalencia del efecto bloqueador de la fase superior de un sexto extracto glicolipídico de páncreas humano (EGP) en 39 sueros ICA+, de 19 pacientes diabéticos insulinodependientes (DID)...