Severity and complications in infants with respiratory syncytial virus infection after the SARS-CoV-2 pandemic.

BACKGROUND: After the SARS-CoV-2 pandemic, there has been an increase in hospitalization for lower respiratory infection secondary to respiratory syncytial virus (RSV), with greater complications. Associated extrapulmonary alterations, biventricular dysfunction, acute kidney injury, among others, have been found. The objective of this study was to analize the evolution and complications in hospitalized children with lower respiratory infection secondary to RSV after COVID-19 pandemic. METHODS: All pediatric patients under 2 years of age admitted to the emergency department with RSV infection were included. Clinical characteristics, need for supplemental oxygen, use of amines, renal angina index, and requirement for renal replacement therapy were analyzed. Lung ultrasound was performed upon admission. Statistical analysis was carried out for the quantitative variables by means of mean and standard deviation, and qualitative variables by frequency and percentage. Differences in the distribution were evaluated with Fisher's exact distribution. RESULTS: 45 patients with RSV infection were identified, 26.7% required invasive mechanical ventilation and 11.1% requiered peritoneal dialysis. Fatality was observed in four cases, three of these younger than 12 months with a LUS score > 7; contrasts with 90.2% of survivors with a score < 7 (p = 0.0004). CONCLUSIONS: An increase in the incidence of bronchiolitis after pandemic was observed, with more than half having moderate to severe symptoms and requiring supplemental oxygen support in all patients upon admission. Acute kidney injury is the most common extrapulmonary manifestation.

INTRODUCCIÓN: Posterior a la pandemia por SARS-CoV-2 se ha observado un incremento en la hospitalización por virus respiratorio sincitial (VRS), con mayores complicaciones. Se han encontrado alteraciones extrapulmonares asociadas, disfunción biventricular y lesión renal aguda, entre otras. El objetivo de este estudio fue analizar la evolución y las complicaciones en niños hospitalizados con enfermedad respiratoria de vías bajas secundaria a infección por VRS tras la pandemia de COVID-19. MÉTODOS: Se incluyeron todos los menores de 2 años que ingresaron al servicio de urgencias con infección por VRS. Se analizaron las características clínicas, la necesidad de oxígeno suplementario, el uso de aminas, el índice de angina renal y el requerimiento de terapia de sustitución renal. Se realizó ecografía pulmonar al ingreso. En el análisis estadístico, para las variables cuantitativas se determinaron la media y la desviación estándar, y para las variables cualitativas la frecuencia y el porcentaje. Se evaluaron las diferencias de la distribución con la prueba exacta de Fisher. RESULTADOS: Hubo 45 pacientes con infección por VRS. El 26.7% requirieron ventilación mecánica invasiva y el 11.1% diálisis peritoneal. La letalidad fue de cuatro casos, tres de ellos menores de 12 meses con puntuación de LUS > 7; esto contrasta con el 90.2% de los sobrevivientes con puntaje < 7 (p = 0.0004). CONCLUSIONES: Se observó un aumento en la incidencia de bronquiolitis tras la pandemia, en más de la mitad de los casos con cuadros de moderados a graves, y todos requirieron oxígeno suplementario al ingreso. La lesión renal aguda fue la manifestación extrapulmonar más frecuente.

Usefulness of lung ultrasound in the evaluation of children with lower respiratory tract infection in the emergency room.

BACKGROUND: Lung ultrasound is a bedside tool that allows the evaluation of pulmonary parenchymal involvement in pediatric patients through the lung ultrasound score (LUS). We aimed to evaluate a group of patients under 3 years of age with lower respiratory tract infections using LUS at the Hospital Infantil del Estado de Sonora. METHODS: We included patients younger than 3 years admitted to the emergency department with lower respiratory tract infections. A lung ultrasound was performed within the first 24 h of admission to the emergency department and evaluated using LUS. We analyzed age, sex, etiology of infection, days of stay, use of mechanical ventilation, Downes scale, failure of mechanical ventilation on admission, and mortality. Descriptive analysis was performed with frequencies and percentages for qualitative variables and medians and interquartile intervals for quantitative variables. Differences in the distribution of LUS variables were evaluated with the Fishers' exact test and Student's t-test. RESULTS: We included a total of 19 patients with lower respiratory tract infections, 73.7% with bronchiolitis. Fifty percent of the cases scored 7 on the LUS, 91.7% were admitted to the pediatric intensive care unit, and 53.8% required invasive mechanical ventilation. CONCLUSIONS: The use of LUS in lower respiratory tract infections can predict the need for PICU admission, the use of invasive ventilatory support, and prolonged hospital stay.

INTRODUCCIÓN: El ultrasonido pulmonar es una herramienta a pie de cama que permite evaluar la afectación del parénquima pulmonar en pacientes pediátricos por medio de la escala de LUS (lung ultrasound score, por sus siglas en inglés). El objetivo del estudio fue evaluar a niños menores de 3 años con infección respiratoria baja mediante la escala de LUS, en el Hospital Infantil del Estado de Sonora. MÉTODOS: Se incluyeron pacientes menores de 3 años que ingresaron al Servicio de Urgencias con infección respiratoria baja. Se realizó ecografía pulmonar en las primeras 24 horas de ingreso a urgencias y se evaluó mediante la escala de LUS. Se analizó, edad, sexo, etiología de la infección, días de estancia, uso de terapia ventilatoria, escala de Downes, fracaso a la terapia ventilatoria de ingreso y mortalidad. Se realizó un análisis descriptivo por medio de frecuencia y porcentaje para las variables cualitativas y para las cuantitativas con mediana e intervalo intercuartil. Las diferencias en la distribución de las variables por la escala de LUS con la prueba exacta de Fisher y la t de Student. RESULTADOS: Se identificaron 19 pacientes con infección pulmonar aguda, de los cuales el 73.7% presentó bronquiolitis. El 50% de los casos obtuvo 7 puntos de la escala de LUS, el 91.7% ingresó a UCIP y el 53.8% requirió ventilación mecánica asistida. CONCLUSIONES: El uso de la escala LUS en infección respiratoria baja puede predecir la necesidad de ingreso a Unidad de Cuidados Intensivos Pediátricos, así como la utilización de soporte ventilatorio invasivo y una estancia hospitalaria prolongada.

Usefulness of lung ultrasound in the evaluation of children with lower respiratory tract infection in the emergency room / Utilidad de ecografía pulmonar en la valoración de niños con infección respiratoria baja en urgencias

Abstract Background: Lung ultrasound is a bedside tool that allows the evaluation of pulmonary parenchymal involvement in pediatric patients through the lung ultrasound score (LUS). We aimed to evaluate a group of patients under 3 years of age with lower respiratory tract infections using LUS at the Hospital Infantil del Estado de Sonora. Methods: We included patients younger than 3 years admitted to the emergency department with lower respiratory tract infections. A lung ultrasound was performed within the first 24 h of admission to the emergency department and evaluated using LUS. We analyzed age, sex, etiology of infection, days of stay, use of mechanical ventilation, Downes scale, failure of mechanical ventilation on admission, and mortality. Descriptive analysis was performed with frequencies and percentages for qualitative variables and medians and interquartile intervals for quantitative variables. Differences in the distribution of LUS variables were evaluated with the Fishers´ exact test and Student´s t-test. Results: We included a total of 19 patients with lower respiratory tract infections, 73.7% with bronchiolitis. Fifty percent of the cases scored 7 on the LUS, 91.7% were admitted to the pediatric intensive care unit, and 53.8% required invasive mechanical ventilation. Conclusions: The use of LUS in lower respiratory tract infections can predict the need for PICU admission, the use of invasive ventilatory support, and prolonged hospital stay.

Resumen Introducción: El ultrasonido pulmonar es una herramienta a pie de cama que permite evaluar la afectación del parénquima pulmonar en pacientes pediátricos por medio de la escala de LUS (lung ultrasound score, por sus siglas en inglés). El objetivo del estudio fue evaluar a niños menores de 3 años con infección respiratoria baja mediante la escala de LUS, en el Hospital Infantil del Estado de Sonora. Métodos: Se incluyeron pacientes menores de 3 años que ingresaron al Servicio de Urgencias con infección respiratoria baja. Se realizó ecografía pulmonar en las primeras 24 horas de ingreso a urgencias y se evaluó mediante la escala de LUS. Se analizó, edad, sexo, etiología de la infección, días de estancia, uso de terapia ventilatoria, escala de Downes, fracaso a la terapia ventilatoria de ingreso y mortalidad. Se realizó un análisis descriptivo por medio de frecuencia y porcentaje para las variables cualitativas y para las cuantitativas con mediana e intervalo intercuartil. Las diferencias en la distribución de las variables por la escala de LUS con la prueba exacta de Fisher y la t de Student. Resultados: Se identificaron 19 pacientes con infección pulmonar aguda, de los cuales el 73.7% presentó bronquiolitis. El 50% de los casos obtuvo 7 puntos de la escala de LUS, el 91.7% ingresó a UCIP y el 53.8% requirió ventilación mecánica asistida. Conclusiones: El uso de la escala LUS en infección respiratoria baja puede predecir la necesidad de ingreso a Unidad de Cuidados Intensivos Pediátricos, así como la utilización de soporte ventilatorio invasivo y una estancia hospitalaria prolongada.

First report of Fusarium oxysporum f. sp. fragariae race 2 causing Fusarium wilt of strawberry (Fragaria × ananassa) in California.

In California, Fusarium wilt of strawberry is widespread and causes significant yield losses. Resistant cultivars with the FW1 gene were protected against Fusarium wilt because all strains of Fusarium oxysporum f. sp. fragariae (Fof) in California were race 1 (i.e., avirulent to FW1-resistant cultivars) (Henry et al. 2017; Pincot, et al. 2018; Henry et al. 2021). In the fall of 2022, severe wilt disease was observed in an organic, summer-planted strawberry field in Oxnard, California. Fusarium wilt symptoms were common and included wilted foliage, deformed and highly chlorotic leaflets, and crown discoloration. The field was planted with Portola, a cultivar with the FW1 gene that is resistant to Fof race 1 (Pincot et al. 2018; Henry et al. 2021). Two samples, each consisting of four plants, were collected from two different locations within the field. Crown extracts from each sample were tested for Fof, Macrophomina phaseolina, Verticillium dahliae, and Phytophthora spp. by recombinase polymerase amplification (RPA) (Steele et al. 2022). Petioles were surface sterilized in 1% sodium hypochlorite for 2 minutes and plated on Komada's medium to select for Fusarium spp. (Henry et al. 2021; Komada, 1975). The RPA results were positive for M. phaseolina in one sample and negative for all four pathogens in the other sample. Salmon-colored, fluffy mycelia grew profusely from petioles of both samples. Colony morphology and non-septate, ellipsoidal microconidia (6.0-13 µm × 2.8-4.0 µm) borne on monophialides resembled F. oxysporum. Single hyphal tip isolation of fourteen cultures (P1-P14) was done to purify single genotypes. None of these pure cultures amplified with Fof-specific qPCR (Burkhardt et al. 2019), confirming the negative result obtained with RPA. Translation elongation factor 1-alpha (EF1α) was amplified using EF1/EF2 primers (O'Donnell et al. 1998) from three isolates. Amplicons were sequenced (GenBank OQ183721) and found through BLAST search to have 100% identity with an isolate of Fusarium oxysporum f. sp. melongenae (GenBank FJ985297). There was at least one nucleotide difference when compared to all known strains of Fof race 1 (Henry et al. 2021). Five isolates (P2, P3, P6, P12, and P13) and an Fof race 1 control isolate (GL1315) were tested for pathogenicity on Fronteras (FW1) and Monterey (fw1; susceptible to race 1). Five plants per isolate × cultivar combination were inoculated by dipping roots in 5 × 106 conidia per mL of 0.1% water agar, or in sterile 0.1% water agar for the negative control, and grown as described by Jenner and Henry (2022). After six weeks, all non-inoculated control plants remained healthy while plants of both cultivars inoculated with the five isolates were severely wilted. Petiole assays yielded colonies identical in appearance to the inoculated isolates. For Fof race 1-inoculated plants, wilt symptoms were observed in Monterey but not in Fronteras. This experiment was repeated with P2, P3, P12, and P13 on another FW1 cultivar, San Andreas, and the same results were observed. To our knowledge, this is the first report of F. oxysporum f. sp. fragariae race 2 in California. Losses to Fusarium wilt are likely to increase until genetic resistance to this strain of Fof race 2 is deployed in commercially viable cultivars.

Sporodochia Formed by Fusarium oxysporum f. sp. fragariae Produce Airborne Conidia and Are Ubiquitous on Diseased Strawberry Plants in California.

Sporodochia are dense masses of fungal hyphae bearing asexual conidia. For Fusarium oxysporum, sporodochia are known to produce airborne conidia and enhance the dissemination of this otherwise soilborne pathogen. Sporodochia are small and transient, and they are documented for only a few formae speciales of F. oxysporum. This study reports airborne conidia and sporodochia produced by F. oxysporum f. sp. fragariae, the cause of Fusarium wilt of strawberry, in the Monterey Bay region of California. Sporodochia were discovered in 21 of 24 Fusarium wilt-diseased fields surveyed for this study and were readily observed on most symptomatic plants in these fields. Only necrotic tissues bore sporodochia, and they were most frequently observed on petioles and peduncles. Sporodochia covered significantly greater lengths of peduncles than petioles, extending from the base of the plant toward the upper part of the canopy. A stolon hosted the longest stretch of sporodochial growth, found covering the stolon's entire 35-cm length and the base of the daughter plant. Macroconidia were produced by all sporodochia samples, and we did not find microconidia on any samples. An initial series of experiments confirmed the potential for conidia produced by sporodochia to disperse with wind over short distances. The prevalence of sporodochia producing airborne spores of F. oxysporum f. sp. fragariae has great importance for disease management and biosecurity. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

In vitro evaluation of new 4-thiazolidinones on invasion and growth of Toxoplasma gondii.

Treatments for toxoplasmosis such as pyrimethamine have shown numerous side effects. It has been reported that the likelihood of relapse associated with pyrimethamine-based therapy in patients with HIV and toxoplasmic encephalitis (TE) can have significant implications, even for patients who often develop new lesions in areas of the brain previously free of infection. This led us to research for new agents against Toxoplasma gondii. Recent findings have shown the potent biological activity of 4-thiazolidinones. We proposed to design and synthesize a new series of 2-hydrazono-4-thiazolidinones derivatives to evaluate the in vitro growth inhibition effect on T. gondii. The growth rates of T. gondii tachyzoites in Human Foreskin Fibroblast (HFF) cell culture were identified by two in vitro methodologies. The first one was by fluorescence in which green fluorescent RH parasites and cherry-red fluorescent ME49 parasites were used. The second one was a colorimetric methodology using ß-Gal parasites of the RH strain constitutively expressing the enzyme beta-galactosidase. The 4-thiazolidinone derivatives 1B, 2B and 3B showed growth inhibition at the same level of Pyrimethamine. These compounds showed IC50 values of 1B (0.468-0.952 µM), 2B (0.204-0.349 µM) and 3B (0.661-1.015 µM) against T. gondii. As a measure of cytotoxicity the compounds showed a TD50 values of: 1B (60 µM), 2B (206 µM) and 3B (125 µM). The in vitro assays and molecular modeling results suggest that these compounds could act as possible inhibitors of the Calcium-Dependent Protein Kinase 1 of T. gondii. Further, our results support the fact that of combining appropriate detection technologies, combinatorial chemistry and computational biology is a good strategy for efficient drug discovery. These compounds merit in vivo analysis for anti-parasitic drug detection.

Importancia del rabdomioma cardiaco en población pediátrica. Experiencia de 39 años. Serie de casos / Importance of heart rabdomioma in pediatric population. A 39 year experience. Case series

Resumen Introducción: Los rabdomiomas son los tumores cardiacos benignos más prevalentes en la etapa fetal y durante la infancia. Objetivo: Nuestro objetivo es dar a conocer nuestra experiencia durante 39 años en pacientes pediátricos con rabdomioma en nuestra institución, así como enfatizar la importancia de su detección, estudio y control por la asociación que tiene con esclerosis tuberosa (ET). Material y métodos: Realizamos un estudio retrospectivo y descriptivo, de enero de 1980 a marzo del 2018. Veinticuatro cumplieron con nuestros criterios, recogimos información respecto a la clínica y estudios de gabinete, así como su evolución y el tratamiento dado. Se les llamó vía telefónica para conocer su evolución y estado actual. Resultados: Encontramos 51 pacientes con diagnóstico de tumor cardiaco, de los cuales 24 eran rabdomiomas. El diagnóstico se hizo prenatal en 8 pacientes, 5 al nacimiento y en 11 durante el primer año de vida. Las manifestaciones clínicas más frecuentes fueron la presencia de soplo, arritmias, cianosis, disnea y diaforesis. En 17 de ellos se hizo diagnóstico de ET. La mitad tuvo seguimiento por neurología, 10 por dermatología, 8 por oftalmología y 4 con genética. La mitad se dejó en vigilancia, a 7 se les dio tratamiento médico y 5 requirieron cirugía. En cuanto a la evolución, 17 pacientes se mantuvieron estables, 5 presentaron regresión espontánea y 2 fallecieron. Conclusiones: El rabdomioma es un tumor benigno poco frecuente, su evolución puede ser maligna y asociado a ET ensombrece el pronóstico.

Abstract Introduction: Rhabdomyomas are the most prevalent benign heart tumors in the fetal stage and during childhood. Objective: Our objective is to make known our experience over 39 years in pediatric patients with rhabdomyoma in our institution, as well as to emphasize the importance of its detection, study and control due to the association it has with tuberous sclerosis (TS). Material and methods: We conducted a retrospective, descriptive and cross-sectional study, from January 1980 to March 2018. Twenty-four met our criteria, we collected information regarding the clinic and cabinet studies, as well as their evolution and the treatment given. They were called by telephone to know their evolution and current status. Results: We found 51 patients with a diagnosis of cardiac tumor, of which 24 were rhabdomyomas. The diagnosis was made prenatal in 8 patients, 5 at birth and in 11 during the first year of life. The most frequent clinical manifestations were the presence of murmur, arrhythmias, cyanosis, dyspnea, and diaphoresis. In 17 of them a diagnosis of TS was made. Half had follow-up by neurology, 10 by dermatology, 8 by ophthalmology and 4 with genetics. Half were left under surveillance, 7 were given medical treatment and 5 required surgery. Regarding the clinical evolution 17 patients remained stable, 5 presented spontaneous regression and 2 died. Conclusions: Rhabdomyoma is a rare benign tumor, its evolution can be malignant and associated with TS, it darkens the prognosis.

[Importance of heart rabdomioma in pediatric population. A 39 year experience. Case series]. / Importancia del rabdomioma cardiaco en población pediátrica. Experiencia de 39 años. Serie de casos.

Introducción: Los rabdomiomas son los tumores cardiacos benignos más prevalentes en la etapa fetal y durante la infancia. Objetivo: Nuestro objetivo es dar a conocer nuestra experiencia durante 39 años en pacientes pediátricos con rabdomioma en nuestra institución, así como enfatizar la importancia de su detección, estudio y control por la asociación que tiene con esclerosis tuberosa (ET). Material y métodos: Realizamos un estudio retrospectivo y descriptivo, de enero de 1980 a marzo del 2018. Veinticuatro cumplieron con nuestros criterios, recogimos información respecto a la clínica y estudios de gabinete, así como su evolución y el tratamiento dado. Se les llamó vía telefónica para conocer su evolución y estado actual. Resultados: Encontramos 51 pacientes con diagnóstico de tumor cardiaco, de los cuales 24 eran rabdomiomas. El diagnóstico se hizo prenatal en 8 pacientes, 5 al nacimiento y en 11 durante el primer año de vida. Las manifestaciones clínicas más frecuentes fueron la presencia de soplo, arritmias, cianosis, disnea y diaforesis. En 17 de ellos se hizo diagnóstico de ET. La mitad tuvo seguimiento por neurología, 10 por dermatología, 8 por oftalmología y 4 con genética. La mitad se dejó en vigilancia, a 7 se les dio tratamiento médico y 5 requirieron cirugía. En cuanto a la evolución, 17 pacientes se mantuvieron estables, 5 presentaron regresión espontánea y 2 fallecieron. Conclusiones: El rabdomioma es un tumor benigno poco frecuente, su evolución puede ser maligna y asociado a ET ensombrece el pronóstico.

New species of the earthworm genus Zapatadrilus (Clitellata, Acanthodrilidae) from northern Mexico.

Three new species of the earthworm genus Zapatadrilus are described from Tamaulipas, Mexico: Zapatadrilus aurelius sp. nov., Zapatadrilus huastecus sp. nov., and Zapatadrilus montezumensis sp. nov. Delimitation of the new species was supported by morphological and molecular (genetic distances) evidence. Diagnostic characters of the three new species include: tubulo-racemose prostates in segments 18 and 20, penial setae absent, typhlosole present and intestine beginning in 17/18. Z. montezumensis sp. nov. is separated by its metandric condition, Z. aurelius sp. nov. by the last hearts in 13 and Z. huastecus sp. nov. by the shape of the spermathecae and patterns of genital markings.

Ultrafast Screening of Synthetic Cannabinoids and Synthetic Cathinones in Urine by RapidFire-Tandem Mass Spectrometry.

Screening for emerging drugs of abuse, specifically synthetic cathinones and synthetic cannabinoids, is difficult for high-throughput laboratories as immunoassay kits are often unavailable. Consequently, most laboratories employ liquid chromatography-tandem mass spectrometry (LC-MS-MS) screening, which can be complex and time consuming as these techniques may require involved sample preparation and lengthy analysis times. The increasing demand for novel psychoactive substance testing necessitates alternative screening methods that are sensitive, fast and versatile. The RapidFire tandem mass spectrometry system (RF-MS-MS) provides a rapid and highly specific screen for these emerging drugs of abuse with minimal sample preparation and an instrumental analysis time of <14 s per sample. Presented here are two RF-MS-MS screening methods used to analyze 28 emerging drugs of abuse, 14 synthetic cannabinoids and 14 synthetic cathinones, in urine with run times of 9 and 12.6 s, respectively. Sample preparation and hydrolysis were performed in a 96-well plate with one multiple reaction monitoring transition used for the identification of each compound. Eighteen thousand urine specimens were screened by liquid-liquid extraction followed by LC-MS-MS analysis, and the results were compared with those obtained using the RF-MS-MS screening method. The analytical data illustrate the advantages of the RF-MS-MS methods.

Analysis of Parent Synthetic Cannabinoids in Blood and Urinary Metabolites by Liquid Chromatography Tandem Mass Spectrometry.

Synthetic cannabinoids emerged on the designer drug market in recent years due to their ability to produce cannabis-like effects without the risk of detection by traditional drug testing techniques such as immunoassay and gas chromatography-mass spectrometry. As government agencies work to schedule existing synthetic cannabinoids, new, unregulated and structurally diverse compounds continue to be developed and sold. Synthetic cannabinoids undergo extensive metabolic conversion. Consequently, both blood and urine specimens may play an important role in the forensic analysis of synthetic cannabinoids. It has been observed that structurally similar synthetic cannabinoids follow common metabolic pathways, which often produce metabolites with similar metabolic transformations. Presented are two validated quantitative methods for extracting and identifying 15 parent synthetic cannabinoids in blood, 17 synthetic cannabinoid metabolites in urine and the qualitative identification of 2 additional parent compounds. The linear range for most synthetic cannabinoid compounds monitored was 0.1-10 ng/mL with the limit of detection between 0.01 and 0.5 ng/mL. Selectivity, specificity, accuracy, precision, recovery and matrix effect were also examined and determined to be acceptable for each compound. The validated methods were used to analyze a compilation of synthetic cannabinoid investigative cases where both blood and urine specimens were submitted. The study suggests a strong correlation between the metabolites detected in urine and the parent compounds found in blood.

Mast cells mediate the immune suppression induced by dermal exposure to JP-8 jet fuel.

Applying jet propulsion-8 (JP-8) jet fuel to the skin of mice induces immune suppression. Applying JP-8 to the skin of mice suppresses T-cell-mediated immune reactions including, contact hypersensitivity (CHS) delayed-type hypersensitivity and T-cell proliferation. Because dermal mast cells play an important immune regulatory role in vivo, we tested the hypothesis that mast cells mediate jet fuel-induced immune suppression. When we applied JP-8 to the skin of mast cell deficient mice CHS was not suppressed. Reconstituting mast cell deficient mice with wild-type bone marrow derived mast cells (mast cell "knock-in mice") restored JP-8-induced immune suppression. When, however, mast cells from prostaglandin E(2) (PGE(2))-deficient mice were used, the ability of JP-8 to suppress CHS was not restored, indicating that mast cell-derived PGE(2) was activating immune suppression. Examining the density of mast cells in the skin and lymph nodes of JP-8-treated mice indicated that jet fuel treatment caused an initial increase in mast cell density in the skin, followed by increased numbers of mast cells in the subcutaneous space and then in draining lymph nodes. Applying JP-8 to the skin increased mast cell expression of CXCR4, and increased the expression of CXCL12 by draining lymph node cells. Because CXCL12 is a chemoattractant for CXCR4+ mast cells, we treated JP-8-treated mice with AMD3100, a CXCR4 antagonist. AMD3100 blocked the mobilization of mast cells to the draining lymph node and inhibited JP-8-induced immune suppression. Our findings demonstrate the importance of mast cells in mediating jet fuel-induced immune suppression.

JP-8 induces immune suppression via a reactive oxygen species NF-kappabeta-dependent mechanism.

Applying jet fuel (JP-8) to the skin of mice induces immune suppression. JP-8-treated keratinocytes secrete prostaglandin E(2), which is essential for activating immune suppressive pathways. The molecular pathway leading to the upregulation of the enzyme that controls prostaglandin synthesis, cyclooxygenase (COX)-2, is unclear. Because JP-8 activates oxidative stress and because reactive oxygen species (ROS) turn on nuclear factor kappa B (NF-kappabeta), which regulates the activity of COX-2, we asked if JP-8-induced ROS and NF-kappabeta contributes to COX-2 upregulation and immune suppression in vivo. JP-8 induced the production of ROS in keratinocytes as measured with the ROS indicator dye, aminophenyl fluorescein. Fluorescence was diminished in JP-8-treated keratinocytes overexpressing catalase or superoxide dismutase (SOD) genes. JP-8-induced COX-2 expression was also reduced to background in the catalase and SOD transfected cells, or in cultures treated with N-acetylcysteine (NAC). When NAC was injected into JP-8-treated mice, dermal COX-2 expression, and JP-8-induced immune suppression was inhibited. Because ROS activates NF-kappabeta, we asked if this transcriptional activator played a role in the enhanced COX-2 expression and JP-8-induced immune suppression. When JP-8-treated mice, or JP-8-treated keratinocytes were treated with a selective NF-kappabeta inhibitor, parthenolide, COX-2 expression, and immune suppression were abrogated. Similarly, when JP-8-treated keratinocytes were treated with small interfering RNA specific for the p65 subunit of NF-kappabeta, COX-2 upregulation was blocked. These data indicate that ROS and NF-kappabeta are activated by JP-8, and these pathways are involved in COX-2 expression and the induction of immune suppression by jet fuel.

Dermal exposure to jet fuel suppresses delayed-type hypersensitivity: a critical role for aromatic hydrocarbons.

Dermal exposure to military (JP-8) and/or commercial (Jet-A) jet fuel suppresses cell-mediated immune reactions. Immune regulatory cytokines and biological modifiers, including platelet activating factor (PAF), prostaglandin E(2), and interleukin-10, have been implicated in the pathway of events leading to immune suppression. It is estimated that approximately 260 different hydrocarbons are found in jet fuel, and the exact identity of the active immunotoxic agent(s) is unknown. The recent availability of synthetic jet fuel (S-8), which is refined from natural gas, and is devoid of aromatic hydrocarbons, made it feasible to design experiments to address this problem. Here we tested the hypothesis that the aromatic hydrocarbons present in jet fuel are responsible for immune suppression. We report that applying S-8 to the skin of mice does not upregulate the expression of epidermal cyclooxygenase-2 (COX-2) nor does it induce immune suppression. Adding back a cocktail of seven of the most prevalent aromatic hydrocarbons found in jet fuel (benzene, toluene, ethylbenzene, xylene, 1,2,4-trimethlybenzene, cyclohexylbenzene, and dimethylnaphthalene) to S-8 upregulated epidermal COX-2 expression and suppressed a delayed-type hypersensitivity (DTH) reaction. Injecting PAF receptor antagonists, or a selective cycloozygenase-2 inhibitor into mice treated with S-8 supplemented with the aromatic cocktail, blocked suppression of DTH, similar to data previously reported using JP-8. These findings identify the aromatic hydrocarbons found in jet fuel as the agents responsible for suppressing DTH, in part by the upregulation of COX-2, and the production of immune regulatory factors and cytokines.

Interleukin-1 beta (IL-1beta) induces tumor necrosis factor alpha (TNF-alpha) expression on mouse myeloid multipotent cell line 32D cl3 and inhibits their proliferation.

Interleukin-1 alpha (IL-1alpha) and beta (IL-1beta) are well known factors that stimulate hematopoiesis, nevertheless there are reports that show that they can also inhibit this activity. While both IL-1alpha and IL-1beta induce the expression of hematopoietic cytokines, such as growth factors and their receptors on myeloid cells, helping thus to regulate hematopoiesis, it is not known if their inhibitory activity is also mediated through the induction of other specific cytokines. In this work we show that recombinant human IL-1beta (rhIL-1beta) inhibits the proliferation of a mouse IL-3-dependent myeloid multipotent cell line (32D cl3), without inducing its differentiation. We show that rhIL-1beta induces in 32D cl3 cells the expression of the tumor necrosis factor alpha (TNF-alpha) gene, a well known growth inhibitor, and that the rhIL-1beta growth inhibition property on 32D cl3 cells is partially due to this secreted TNF-alpha, hinting thus that the inhibition of hematopoiesis by IL-1 is mediated through other induced cytokines.

Sodium caseinate induces expression and secretion of murine multipotent myeloid cell line 32D macrophage colony-stimulating factor.

BACKGROUND: Evidence that sodium caseinate (CasNa) is capable of inhibiting proliferation of hematopoietic precursor cell line 32D and inducing its differentiation into macrophage cells has recently been published. Taking into consideration that hematopoiesis is regulated by growth factors and that macrophage colony-stimulating factor (M-CSF) is a well-known growth factor that induces differentiation of macrophages, in this work we evaluated whether CasNa is capable of inducing expression and secretion of M-CSF in 32D cells. METHODS: We cultured 32D cells in presence and absence of CasNa and compared their proliferation and viability. RNA was extracted from cell lysates to evaluate expression of the gene for M-CSF and its receptor. Cultured conditioned media was used to evaluate presence of M-CSF. RESULTS: Our results showed that CasNa inhibited proliferation of 32D cells and that conditioned media (CM) of these cultures contained M-CSF-like activity. Presence of M-CSF in CM was detected by inhibiting M-CSF activity with anti-M-CSF and presence of this growth factor was confirmed by ELISA assay. We also provided evidence that CasNa induced expression of mRNA for M-CSF in 32D cells as well as increased expression of mRNA for its receptor. CONCLUSIONS: CasNa inhibits proliferation of 32D cells and induces expression of the gene for M-CSF and that of its receptor. It also induces secretion of the bioactive form of M-CSF.

Platelet activating factor receptor binding plays a critical role in jet fuel-induced immune suppression.

Applying military jet fuel (JP-8) or commercial jet fuel (Jet-A) to the skin of mice suppresses the immune response in a dose-dependent manner. The release of biological response modifiers, particularly prostaglandin E2 (PGE2), is a critical step in activating immune suppression. Previous studies have shown that injecting selective cyclooxygenase-2 inhibitors into jet fuel-treated mice blocks immune suppression. Because the inflammatory phospholipid mediator, platelet-activating factor (PAF), up-regulates cyclooxygenase-2 production and PGE2 synthesis by keratinocytes, we tested the hypothesis that PAF-receptor binding plays a role in jet fuel-induced immune suppression. Treating keratinocyte cultures with PAF and/or jet fuel (JP-8 and Jet-A) stimulates PGE2 secretion. Jet fuel-induced PGE2 production was suppressed by treating the keratinocytes with specific PAF-receptor antagonists. Injecting mice with PAF, or treating the skin of the mice with JP-8, or Jet-A, induced immune suppression. Jet fuel-induced immune suppression was blocked when the jet fuel-treated mice were injected with PAF-receptor antagonists before treatment. Jet fuel treatment has been reported to activate oxidative stress and treating the mice with anti-oxidants (Vitamins C, or E or beta-hydroxy toluene), before jet fuel application, interfered with immune suppression. These findings confirm previous studies showing that PAF-receptor binding can modulate immune function. Furthermore, they suggest that PAF-receptor binding may be an early event in the induction of immune suppression by immunotoxic environmental agents that target the skin.

Dermal application of jet fuel suppresses secondary immune reactions.

Applying military jet fuel (JP-8) to the skin of mice activates systemic immune suppression. In all of our previous experiments, JP-8 was applied to immunologically naïve mice. The effect of jet fuels on established immune reactions, such as immunological memory, is unknown. The focus of the experiments presented here was to test the hypothesis that jet fuel exposure [both JP-8 and commercial jet fuel (Jet-A)] suppresses established immune reactions. Mice were immunized with the opportunistic fungal pathogen Candida albicans and, at different times after immunization (10 to 30 days), various doses of undiluted JP-8 or Jet-A were applied to their skin. Both the elicitation of delayed-type hypersensitivity (DTH) (mice challenged 10 days after immunization) and immunological memory (mice challenged 30 days after immunization) were significantly suppressed in a dose-dependent manner. Dermal exposure to either multiple small doses (50 microl over 4 days) or a single large dose (approximately 200-300 microl) of JP-8 and/or Jet-A suppressed DTH to C. albicans. The mechanism by which dermal application of JP-8 and Jet-A suppresses immunological memory involves the release of immune biologic response modifiers. Blocking the production of prostaglandin E(2) by a selective cyclooxygenase-2 inhibitor (SC 236) significantly reversed jet fuel-induced suppression of immunologic memory. These findings indicate, for the first time, that dermal exposure to commercial jet fuel (Jet-A) suppresses the immune response. In addition, the data reported here expand on previous findings by suggesting that jet fuel exposure may depress the protective effect of prior vaccination.

El caseinato de sodio induce la diferenciación de las células hematopoyéticas multipotenciales 32D / Sodium caseinate induces differentiation of the multipotential hemopoietic cell line 32D

Objetivo. Evaluar la participación del caseinato de sodio (CasNa) en la modulación de la hematopoyesis. Material y métodos. Se emplearon células 32D, una línea celular hematopoyética multipotencial, de origen murino y dependiente de interleucina-3. Estas células se cultivaron con 0.5 ng/mL de interleucina-3 y con concentraciones variables de CasNa. En los cultivos se realizaron estudios de proliferación celular (conteo directo e incorporación de timidina 3H) y de diferenciación morfológica (tinción con Giemsa), citoquímica (tinciones específicas para monocito-macrófagos y para granulocitos) y funcional (presencia de receptores Fc y reducción de nitro azul de tetrazolio), además se determinó la viabilidad con azul de tripano y la apoptosis por la reacción Tunel in situ. Resultados. Se demostró que el CasNa produce una reducción en la proliferación, dependiente de la dosis, que ésta no es provocada por una disminución de la viabilidad de las células 32D así como tampoco por un aumento de la muerte celular por apoptosis. Además el CasNa indujo la diferenciación de las células 32D hacia monocito-macrófagos en cultivos de 4 días. Conclusiones. Aparentemente el CasNa ejerce una actividad tipo factor estimulador de colonias de macrófagos. Además, parece ser un potente factor de diferenciación de las células 32D, ya que en sólo 4 días de estímulo genera células de tipo monocito-macrófago, a diferencia de los 7 días requeridos por la combinación de G-CSF y GM-CSF.