Corticodependent and recurrent inflammatory pseudo tumor. Analysis of cases and review.

Inflammatory pseudo tumor (IP) is an infrequent process with benign evolution in most cases whose etiology and pathogenesis are unknown. It usually affects young men and children, in whom the macroscopic lesion can mimic a malignant process, which is ruled out after biopsy. Therefore, the diagnosis of certainty is histological and treatment consists of corticosteroids, leaving resection for cases in which biopsy is not possible or in which it produces local complications. We present a case of an inflammatory pseudo tumor with special corticodependence that began as a long-term periodic fever and splenic focal lesion that required splenectomy for its diagnosis and that, after decreasing the corticosteroid regimen, presented recurrences at the cerebellar and systemic level requiring the association of various immunosuppressants and rituximab to achieve remission. As a result of this case, we have performed an analysis of all the pseudo tumors diagnosed in adults in the hospitals of the province of Malaga, and it has been compared with that described in the bibliography.

Apoptotic contraction drives target cell release by cytotoxic T cells.

Cytotoxic T lymphocytes (CTLs) fight intracellular pathogens and cancer by identifying and destroying infected or transformed target cells1. To kill, CTLs form a specialized cytotoxic immune synapse (IS) with a target of interest and then release toxic perforin and granzymes into the interface to elicit programmed cell death2-5. The IS then dissolves, enabling CTLs to search for additional prey and professional phagocytes to clear the corpse6. While the mechanisms governing IS assembly have been studied extensively, far less is known about target cell release. Here, we applied time-lapse imaging to explore the basis for IS dissolution and found that it occurred concomitantly with the cytoskeletal contraction of apoptotic targets. Genetic and pharmacological perturbation of this contraction response indicated that it was both necessary and sufficient for CTL dissociation. We also found that mechanical amplification of apoptotic contractility promoted faster CTL detachment and serial killing. Collectively, these results establish a biophysical basis for IS dissolution and highlight the importance of mechanosensory feedback in the regulation of cell-cell interactions.

A linear SARS-CoV-2 DNA vaccine candidate reduces virus shedding in ferrets.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), has caused more than 760 million cases and over 6.8 million deaths as of March 2023. Vaccination has been the main strategy used to contain the spread of the virus and to prevent hospitalizations and deaths. Currently, two mRNA-based vaccines and one adenovirus-vectored vaccine have been approved and are available for use in the U.S. population. The versatility, low cost, and rapid production of DNA vaccines provide important advantages over other platforms. Additionally, DNA vaccines efficiently induce both B- and T-cell responses by expressing the antigen within transfected host cells, and the antigen, after being processed into peptides, can associate with MHC class I or II of antigen-presenting cells (APCs) to stimulate different T cell responses. However, the efficiency of DNA vaccination needs to be improved for use in humans. Importantly, in vivo DNA delivery combined with electroporation (EP) has been used successfully in the field of veterinary oncology, resulting in high rates of response after electrochemotherapy. Here, we evaluate the safety, immunogenicity, and protective efficacy of a novel linear SARS-CoV-2 DNA vaccine candidate delivered by intramuscular injection followed by electroporation (Vet-ePorator™) in ferrets. The linear SARS-CoV-2 DNA vaccine candidate did not cause unexpected side effects. Additionally, the vaccine elicited neutralizing antibodies and T cell responses on day 42 post-immunization using a low dose of the linear DNA construct in a prime-boost regimen. Most importantly, vaccination significantly reduced shedding of infectious SARS-CoV-2 through oral and nasal secretions in a ferret model.

A linear DNA encoding the SARS-CoV-2 receptor binding domain elicits potent immune response and neutralizing antibodies in domestic cats.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiologic agent of the COVID-19 pandemic, has been shown to infect a wide range of animal species, especially mammals, and besides human-to-human transmission, human-to-animal transmission has also been observed in some wild animals and pets, especially in cats. It has been demonstrated that cats are permissive to COVID-19 and are susceptible to airborne infections. Given the high transmissibility potential of SARS-CoV-2 to different host species and the close contact between humans and animals, it is crucial to find mechanisms to prevent the transmission chain and reduce the risk of spillover to susceptible species. Here, we show results from a clinical trial conducted in domestic cats to assess safety and immunogenicity of a linear DNA (linDNA) vaccine encoding the receptor-binding domain (RBD) from SARS-CoV-2 (Lin-COVID-eVax). Lin-COVID-eVax proved to be safe, with no significant adverse events, and was able to elicit both RBD-specific antibodies and T cells. Also, the linDNA vaccine induced neutralizing antibody titers against ancestral SARS-CoV-2 virus and its variants. These findings demonstrate the safety and immunogenicity of a genetic vaccine against COVID-19 administered to cats and strongly support the development of vaccines for preventing viral spread in susceptible species, especially those in close contact with humans.

Mechanically active integrins target lytic secretion at the immune synapse to facilitate cellular cytotoxicity.

Cytotoxic lymphocytes fight pathogens and cancer by forming immune synapses with infected or transformed target cells and then secreting cytotoxic perforin and granzyme into the synaptic space, with potent and specific killing achieved by this focused delivery. The mechanisms that establish the precise location of secretory events, however, remain poorly understood. Here we use single cell biophysical measurements, micropatterning, and functional assays to demonstrate that localized mechanotransduction helps define the position of secretory events within the synapse. Ligand-bound integrins, predominantly the αLß2 isoform LFA-1, function as spatial cues to attract lytic granules containing perforin and granzyme and induce their fusion with the plasma membrane for content release. LFA-1 is subjected to pulling forces within secretory domains, and disruption of these forces via depletion of the adaptor molecule talin abrogates cytotoxicity. We thus conclude that lymphocytes employ an integrin-dependent mechanical checkpoint to enhance their cytotoxic power and fidelity.

Cytotoxic lymphocytes target characteristic biophysical vulnerabilities in cancer.

Immune cells identify and destroy tumors by recognizing cellular traits indicative of oncogenic transformation. In this study, we found that myocardin-related transcription factors (MRTFs), which promote migration and metastatic invasion, also sensitize cancer cells to the immune system. Melanoma and breast cancer cells with high MRTF expression were selectively eliminated by cytotoxic lymphocytes in mouse models of metastasis. This immunosurveillance phenotype was further enhanced by treatment with immune checkpoint blockade (ICB) antibodies. We also observed that high MRTF signaling in human melanoma is associated with ICB efficacy in patients. Using biophysical and functional assays, we showed that MRTF overexpression rigidified the filamentous actin cytoskeleton and that this mechanical change rendered mouse and human cancer cells more vulnerable to cytotoxic T lymphocytes and natural killer cells. Collectively, these results suggest that immunosurveillance has a mechanical dimension, which we call mechanosurveillance, that is particularly relevant for the targeting of metastatic disease.

[V grade renal trauma in patient with union pyeloureteral stenosis not known.] / Traumatismo renal grado v en paciente con estenosis de la unión pieloureteral no conocida.

Paciente de 40 años de edad, sin alergias medicamentosas conocidas y sin antecedentesde interés, que es traído a Urgencias por dispositivo de cuidados críticos por politraumatismo tras accidente de moto...

Paciente de 40 años de edad, sin alergias medicamentosas conocidas y sin antecedentesde interés, que es traído a Urgencias por dispositivo de cuidados críticos por politraumatismo tras accidente de moto...

Transverse Myelitis in Systemic Lupus Erythematosus: Clinical Features and Prognostic Factors in a Large Cohort of Latin American Patients.

BACKGROUND: Acute transverse myelitis (ATM) is an infrequent but severe complication of systemic lupus erythematosus (SLE). The purpose of study was to describe clinical features and prognostic factors of patients with SLE-related ATM. METHODS: In this medical records review study, data were collected from 60 patients from 16 centers seen between 1996 and 2017 who met diagnostic criteria for SLE and myelitis as defined by the American College of Rheumatology/Systemic International Collaborating Clinics and the Working Group of the Transverse Myelitis Consortium, respectively. Objective neurological impairment was measured with American Spinal Injury Association Impairment Scale (AIS) and European Database for Multiple Sclerosis Grade Scale (EGS). RESULTS: Among patients included, 95% (n = 57) were female, and the average age was 31.6 ± 9.6 years. Myelitis developed after diagnosis of SLE in 60% (n = 36). Symmetrical paraparesis with hypoesthesia, flaccidity, sphincter dysfunction, AIS = A/B, and EGS ≥ 8 was the most common presentation. Intravenous methylprednisolone was used in 95% (n = 57), and 78.3% (n = 47) received intravenous cyclophosphamide. Sensory/motor recovery at 6 months was observed in 75% (42 of 56), but only in 16.1% (9 of 56) was complete. Hypoglycorrhachia and EGS ≥ 7 in the nadir were associated with an unfavorable neurological outcome at 6 months (p < 0.05). A relapse rate during follow-up was observed in 30.4% (17 of 56). Hypoglycorrhachia and hypocomplementemia seem to be protective factors for relapse. Intravenous cyclophosphamide was associated with time delay to relapse. CONCLUSIONS: Systemic lupus erythematosus-related ATM may occur at any time of SLE course, leading to significant disability despite treatment. Relapses are infrequent and intravenous cyclophosphamide seems to delay it. Hypoglycorrhachia, hypocomplementemia, and EGS at nadir are the most important prognostic factors.

Growth Performance After Agouti-Signaling Protein 1 (Asip1) Overexpression in Transgenic Zebrafish.

The melanocortin system is a key structure in the regulation of energy balance. Overexpression of inverse agonists, agouti-signaling protein (ASIP), and agouti-related protein (AGRP) results in increased food intake, linear growth, and body weight. ASIP regulates dorsal-ventral pigment polarity through melanocortin 1 receptor (MC1R) and overexpression induces obesity in mice by binding to central MC4R. Asip1 overexpression in transgenic zebrafish (asip1-Tg) enhances growth, yet experiments show fish overexpressing Asip1 do not develop obesity even under severe feeding regimes. Asip1-Tg fish do not need to eat more to grow larger and faster; thus, increased food efficiency can be observed. In addition, asip1-Tg fish reared at high density are able to grow far more than wild-type (WT) fish reared at low density, although asip1-Tg fish seem to be more sensitive to crowding stress than WT fish, thus making the melanocortin system a target for sustainable aquaculture, especially as the U.S. Food and Drug Association has recently approved transgenic fish trading.

Brain transcriptome profile after CRISPR-induced ghrelin mutations in zebrafish.

Ghrelin (GRL) is a gut-brain hormone with a role in a wide variety of physiological functions in mammals and fish, which points out the ghrelinergic system as a key element for the appropriate biological functioning of the organism. However, many aspects of the multifunctional nature of GRL remain to be better explored, especially in fish. In this study, we used the CRISPR/Cas9 genome editing technique to generate F0 zebrafish in which the expression of grl is compromised. Then, we employed high-throughput mRNA sequencing (RNA-seq) to explore changes in the brain transcriptome landscape associated with the silencing of grl. The CRISPR/Cas9 technique successfully edited the genome of F0 zebrafish resulting in individuals with considerably lower levels of GRL mRNAs and protein and ghrelin O-acyl transferase (goat) mRNAs in the brain, intestine, and liver compared to wild-type (WT) zebrafish. Analysis of brain transcriptome revealed a total of 1360 differentially expressed genes (DEGs) between the grl knockdown (KD) and WT zebrafish, with 664 up- and 696 downregulated DEGs in the KD group. Functional enrichment analysis revealed that DEGs are highly enriched for terms related to morphogenesis, metabolism (especially of lipids), entrainment of circadian clocks, oxygen transport, apoptosis, and response to stimulus. The present study offers valuable information on the central genes and pathways implicated in functions of GRL, and points out the possible involvement of this peptide in some novel functions in fish, such as apoptosis and oxygen transport.

Prevalencia de diabetes mellitus y sus complicaciones en adultos mayores en un centro de referencia / Prevalence of diabetes mellitus and its complications in older adults in a reference center

Una de las enfermedades crónicas no transmisibles más prevalentes del adulto mayor es la Diabetes Mellitus tipo 2 (DM2). En este grupo poblacional la DM2 se asocia a pérdida de funcionalidad, reducción de masa muscular, aumento de comorbilidades y muerte prematura, afectando significativamente la calidad de vida. Objetivo Establecer la prevalencia de DM2 y sus complicaciones crónicas en el adulto mayor. Pacientes y métodos Estudio descriptivo, transversal. Se estudiaron a 27469 pacientes adultos mayores con DM2 que acudieron a la consulta externa del Hospital General Enrique Garcés. Se investigó edad, género, etnia, zona de vivienda, nivel de instrucción, comorbilidades, tiempo de la enfermedad, medidas antropométricas, exámenes de laboratorio, complicaciones crónicas y tratamiento. Los datos fueron analizados en el programa Estadístico para las Ciencias Sociales (SPSS) v24. Se realizó un análisis descriptivo y estadística inferencial. Resultados El 71.13% (19538) fueron mujeres, 66.5% (18267) tenía educación primaria, 68% (18679) era diabéticos más de 10 años; 85% (23349) tenían hipertensión arterial (HTA). Las complicaciones encontradas fueron neuropatía, micro albuminuria patológica, retinopatía y pie diabético, 11.86% (3258) pacientes tuvieron una hemoglobina glicosilada (HbA1C) dentro de parámetros normales. Conclusiones La prevalencia de DM2 entre adultos mayores de 75 años fue del 14%, y la presencia de complicaciones crónicas estuvo relacionada al mayor tiempo de evolución de la enfermedad junto a valores de HbA1C más altos.

One of the most prevalent chronic noncommunicable diseases of the older adult is type 2 Diabetes Mellitus (DM2). In this population group DM2 is associated with loss of functionality, reduced muscle mass, increased comorbidities and premature death, significantly affecting quality of life. Objective To establish the prevalence of DM2 and its chronic complications in the elderly. Patients and methods Descriptive, cross-sectional study. 27469 older adult patients with 2DM who attended the outpatient clinic of the Enrique Garcés General Hospital were studied. Age, gender, ethnicity, area of residence, level of education, comorbidities, time of illness, anthropometric measurements, laboratory tests, chronic complications, and treatment were investigated. The data was analyzed in the Statistical Program for Social Sciences (SPSS) v24. A descriptive and inferential statistical analysis was performed. Results The 71.13% (19538) were women, 66.5% (18267) had a primary education, 68% (18679) were diabetics over 10 years; 85% (23349) had high blood pressure (HT). The complications found were neuropathy, pathological micro albuminuria, retinopathy and diabetic foot, 11.86% (3258) patients had a glycated hemoglobin (HbA1C) within normal parameters. Conclusions The prevalence of DM2 among adults over 75 years of age was 14%, and the presence of chronic complications was related to the longer evolution time of the disease along with higher HbA1C values.

El Perfil Epidemiológico Y Clínico De La Esclerosis Múltiple En El Ecuador / The Clinical And Epidemiological Profile Of Multiple Sclerosis In Ecuador

Resumen En el Ecuador ha habido un importante incremento en el número de publicaciones sobre Esclerosis Múltiple (EM) en los últimos años. Este interés por conocer el comportamiento clínico y epidemiológico de la enfermedad nos ha permitido establecer semejanzas y diferencias con otras cohortes de pacientes con EM que provienen de regiones en donde la prevalencia de la enfermedad es alta. El Ecuador sigue siendo un país de baja prevalencia, los estudios han demostrado que la misma fluctúa entre 3 a 5 casos por 100.000 habitantes. El comportamiento epidemiológico es muy similar a la de cohortes europeas por ejemplo el sexo femenino es el principalmente afectado. Sin embargo, el comportamiento clínico difiere en lo que respecta a deterioro cognitivo, fatiga siendo éstos menos frecuentes. Aún se desconoce el impacto de la vitamina D en nuestros pacientes debido a que, solo un estudio ha sido llevado a cabo. Al parecer, existe una alta prevalencia de deficiencia e insuficiencia de vitamina D en los pacientes ecuatorianos pero no se traduce en un incremento de prevalencia o discapacidad como ocurre en poblaciones europeas. A pesar de que tenemos una mejor comprensión de la enfermedad en el país, más estudios son necesarios y es imperativo incluir a todos los pacientes ecuatorianos con esclerosis múltiple con el fin de mejorar nuestro conocimiento sobre el comportamiento de esta patología en nuestra región.

Abstract In recent years, the number of publications on Multiple Sclerosis (MS) from Ecuador has seen a significant increase. As a result, the research on the clinical and epidemiological behaviour of the disease has allowed us to make comparisons with other cohorts of patients with MS that come from regions where the prevalence of the disease is high. Nevertheless, Ecuador is still a country in which the prevalence of MS is low with a prevalence that fluctuates between 3 to 5 cases per 100,000 inhabitants. The epidemiological behaviour of MS is very similar to that of european cohorts, for example female patients are the most affected. However, the clinical behaviour of multiple sclerosis differs in terms of cognitive impairment and fatigue being less frequent. The impact of vitamin D on patients with MS is still unknown as only one study has been carried out. This study show that there is a high prevalence of vitamin D deficiency and insufficiency in ecuadorian patients, but this does not translate into an increase in prevalence or disability as it does in european populations. Although we have a better understanding of the disease in the country, more studies are necessary, and it is imperative that all ecuadorian patients with MS be included in future studies in order to improve our knowledge about the behaviour of this disease in our region.

Actin clearance promotes polarized dynein accumulation at the immunological synapse.

Immunological synapse (IS) formation between a T cell and an antigen-presenting cell is accompanied by the reorientation of the T cell centrosome toward the interface. This polarization response is thought to enhance the specificity of T cell effector function by enabling the directional secretion of cytokines and cytotoxic factors toward the antigen-presenting cell. Centrosome reorientation is controlled by polarized signaling through diacylglycerol (DAG) and protein kinase C (PKC). This drives the recruitment of the motor protein dynein to the IS, where it pulls on microtubules to reorient the centrosome. Here, we used T cell receptor photoactivation and imaging methodology to investigate the mechanisms controlling dynein accumulation at the synapse. Our results revealed a remarkable spatiotemporal correlation between dynein recruitment to the synaptic membrane and the depletion of cortical filamentous actin (F-actin) from the same region, suggesting that the two events were causally related. Consistent with this hypothesis, we found that pharmacological disruption of F-actin dynamics in T cells impaired both dynein accumulation and centrosome reorientation. DAG and PKC signaling were necessary for synaptic F-actin clearance and dynein accumulation, while calcium signaling and microtubules were dispensable for both responses. Taken together, these data provide mechanistic insight into the polarization of cytoskeletal regulators and highlight the close coordination between microtubule and F-actin architecture at the IS.

Sensing Glucose in the Central Melanocortin Circuits of Rainbow Trout: A Morphological Study.

In mammals, glucosensing markers reside in brain areas known to play an important role in the control of food intake. The best characterized glucosensing mechanism is that dependent on glucokinase (GK) whose activation by increased levels of glucose leads in specific hypothalamic neurons to decreased or increased activity, ultimately leading to decreased food intake. In fish, evidence obtained in recent years suggested the presence of GK-like immunoreactive cells in different brain areas related to food intake control. However, it has not been established yet whether or not those neuronal populations having glucosensing capacity are the same that express the neuropeptides involved in the metabolic control of food intake. Therefore, we assessed through dual fluorescent in situ hybridization the possible expression of GK in the melanocortinergic neurons expressing proopiomelanocortin (POMC) or agouti-related protein (AGRP). POMC and AGRP expression localized exclusively in the rostral hypothalamus, in the ventral pole of the lateral tuberal nucleus, the homolog of the mammalian arcuate nucleus. Hypothalamic GK expression confined to the ependymal cells coating the ventral pole of the third ventricle but some expression level occurred in the AGRP neurons. GK expression seems to be absent in the hypothalamic POMC neurons. These results suggest that AGRP neurons might sense glucose directly through a mechanism involving GK. In contrast, POMC neurons would not directly respond to glucose through GK and would require presynaptic inputs to sense glucose. Ependymal cells could play a critical role relying glucose metabolic information to the central circuitry regulating food intake in fish, especially in POMC neurons.

Neoplasia de Células Dendríticas Plasmocitoides blásticas: reporte del primer caso en Ecuador / Blastic Plasmacytoid Dendritic Cell Neoplasm : First Case Report in Ecuador

La Neoplasia de Células Dendríticas Plasmocitoides blásticas (Blastic Plasmacytoid dendritic cell neoplasm ­ BPDCN) es una neoplasia hematológica rara, agresiva, de difícil diagnóstico y con alta mortalidad. Se describe el primer caso en el Ecuador de un paciente joven sin antecedentes patológicos relevantes, ingresado al servicio de Medicina Interna del Hospital Enrique Garcés por presentar máculas cutáneas, artralgias y mialgias, que se complica con derrame pleural tipo exudativo y mala mecánica respiratoria. Exámenes de extensión revelaron: Leucemia mieloide aguda de tipo M2, motivo por el cual fue referido a centro oncológico de referencia para completar estudio y manejo. Estudios citogenéticos y fenotípicos corroboraron el diagnóstico de BPDCN, se instauró tratamiento con protocolo Hyper-CVAD, sin embargo, el paciente presentó compromiso respiratorio, renal y hematológico que progresó a choque refractario y óbito. La naturaleza agresiva de esta rara leucemia es una limitante en el tiempo para instaurar un tratamiento dirigido, determinando en la mayoría de los casos una alta mortalidad

La Neoplasia de Células Dendríticas Plasmocitoides blásticas (Blastic Plasmacytoid dendritic cell neoplasm ­ BPDCN) es una neoplasia hematológica rara, agresiva, de difícil diagnóstico y con alta mortalidad. Se describe el primer caso en el Ecuador de un paciente joven sin antecedentes patológicos relevantes, ingresado al servicio de Medicina Interna del Hospital Enrique Garcés por presentar máculas cutáneas, artralgias y mialgias, que se complica con derrame pleural tipo exudativo y mala mecánica respiratoria. Exámenes de extensión revelaron: Leucemia mieloide aguda de tipo M2, motivo por el cual fue referido a centro oncológico de referencia para completar estudio y manejo. Estudios citogenéticos y fenotípicos corroboraron el diagnóstico de BPDCN, se instauró tratamiento con protocolo Hyper-CVAD, sin embargo, el paciente presentó compromiso respiratorio, renal y hematológico que progresó a choque refractario y óbito. La naturaleza agresiva de esta rara leucemia es una limitante en el tiempo para instaurar un tratamiento dirigido, determinando en la mayoría de los casos una alta mortalidad

Factores pronósticos de la Esclerosis Múltiple / Prognostic factors in Multiple Sclerosis

Resumen La Esclerosis Múltiple es una enfermedad inflamatoria y degenerativa del Sistema Nervioso Central que afecta a la población adulta joven. La prevalencia de esta entidad es heterogénea en el mundo y baja en el Ecuador. El diagnóstico se basa en los criterios de McDonald 2017. Una vez que el diagnóstico se ha establecido, es necesario determinar si los pacientes tienen factores de mal pronóstico los cuales van a generar un impacto en el tipo de tratamiento a elegir. Al momento, se han estudiado factores pronósticos epidemiológicos, clínicos, biomoleculares y de imagen los cuales nos permiten predecir si la enfermedad tiene un comportamiento agresivo o por el contrario un curso benigno. El número de lesiones en las imágenes de resonancia magnética cerebral, la presencia de lesiones en tronco encefálico y médula espinal son los factores que han demostrado tener un impacto en la progresión de discapacidad. La presencia de bandas oligoclonales en el líquido cefalorraquídeo tiene un rol fundamental en la conversión de un síndrome clínico aislado en esclerosis múltiple clínicamente establecida. Los niveles bajos de vitamina D ha demostrado estar asociado con mal pronóstico pero su aplicabilidad en países como el Ecuador es aún tema de investigación.

Abstract Multiple sclerosis is an inflammatory and degenerative disease of the central nervous system which affects young adults. The prevalence of multiple sclerosis in the world is heterogeneous and is low in Ecuador. The diagnosis is based on the McDonald 2017 criteria. Once the diagnosis has been made, it is necessary that any negative factors which will impact the type of treatment used be identified. At this time, factors such as epidemiological, clinical, biomolecular, and magnetic resonance images, which will allow us to identify if the case is aggressive or benign, are studied. The number of lesions shown in a brain MRI, the presence of lesions in the brain stem and spinal cord are factors which have been demonstrated to have an impact on the progression of disability. The presence of oligoclonal bands in the cerebrospinal fluid has a fundamental role in the conversion of an isolated clinical syndrome to multiple sclerosis. Low levels of vitamin D have been associated with a negative prognosis, however how important vitamin D is in the prognosis of MS in countries such as Ecuador is still an area to be studied.

Spatial and Temporal Control of T Cell Activation Using a Photoactivatable Agonist.

T lymphocytes engage in rapid, polarized signaling, occurring within minutes following TCR activation. This induces formation of the immunological synapse, a stereotyped cell-cell junction that regulates T cell activation and directionally targets effector responses. To study these processes effectively, an imaging approach that is tailored to capturing fast, polarized responses is necessary. This protocol describes such a system, which is based on a photoactivatable peptide-major histocompatibility complex (pMHC) that is non-stimulatory until it is exposed to ultraviolet light. Targeted decaging of this reagent during videomicroscopy experiments enables precise spatiotemporal control of TCR activation and high-resolution monitoring of subsequent cellular responses by total internal reflection (TIRF) imaging. This approach is also compatible with genetic and pharmacological perturbation strategies. This allows for the assembly of well-defined molecular pathways that link TCR signaling to the formation of the polarized cytoskeletal structures that underlie the immunological synapse.

Coexistence of systemic lupus erythematosus and multiple sclerosis. A case report and literature review.

Multiple sclerosis (MS) and systemic lupus erythematous (SLE) are autoimmune diseases, the coexistence of which is uncommon in patients. Owing to the rarity of this condition, the distinction between MS and SLE is a diagnostic challenge for neurologists. We present a case report in which MS and SLE were present in the same patient. There are few case reports in the world on the association between MS and SLE. The following case report is the first of its kind in which both MS and SLE are present in a patient from a country with low prevalence of MS such as Ecuador.