Safety and efficacy of ivacaftor in infants aged 1 to less than 4 months with cystic fibrosis.

BACKGROUND: Ivacaftor (IVA) has been shown to be safe and efficacious in children aged ≥4 months with cystic fibrosis (CF) and CFTR gating variants. We evaluated safety, pharmacokinetics (PK), and efficacy of IVA in a small cohort of infants aged 1 to <4 months with CF. METHODS: In this phase 3, open-label study, infants 1 to <4 months with CF and an IVA-responsive CFTR variant received an initial low dose of IVA based on age and weight. Because IVA is a sensitive CYP3A substrate and CYP3A maturation is uncertain in infants, doses were adjusted at day 15 to better match median adult exposures based on individual PK measurements taken on day 4. Primary endpoints were safety and PK measurements. RESULTS: Seven infants (residual function CFTR variants [n=5]; minimal function CFTR variants [n=2]) received ≥1 dose of IVA. Six infants had doses adjusted at day 15 and one infant did not require dose adjustment; subsequent PK analyses showed mean trough concentrations for IVA and metabolites were within range of prior clinical experience. Four infants (57.1%) had adverse events (AEs); no serious AEs were noted. One infant discontinued study drug due to a non-serious AE of elevated alanine aminotransferase >8x the upper limit of normal. Mean sweat chloride concentration decreased (-40.3 mmol/L [SD: 29.2]) through week 24. Improvements in biomarkers of pancreatic function and intestinal inflammation, as well as growth parameters, were observed. CONCLUSIONS: In this small, open-label study, IVA dosing in infants achieved exposures previously shown to be safe and efficacious. Because PK was predictable, a dosing regimen based on age and weight is proposed. IVA was generally safe and well tolerated, and led to improvements in CFTR function, markers of pancreatic function and intestinal inflammation, and growth parameters, supporting use in infants as young as 1 month of age.

Pathways of depressive symptoms to self-harm and suicide warning signs during COVID-19 pandemic: The role of anxiety and related distress, dysfunction and somatization.

BACKGROUND: Early in the COVID-19 pandemic, concern about widespread waves of depression and suicide emerged worldwide. Clarity on the relationship between mental health symptoms and warning signs of current self-harm or suicide thoughts and behaviors (ShSTB) in Mexican adults could be useful for designing effective public health policies and preventive strategies during health emergencies. OBJECTIVE: The present study uses a path model to explore the relationship between depressive symptoms, anxiety, and related distress, dysfunction, and somatization with ShSTB warning signs in Mexican adults during the COVID-19 pandemic. The study also describes the relative risks of these mental health variables for men and women, and for those who were seeking psychological care versus those who were not. METHOD: The study was conducted with 18,449 Mexicans (M = 33 years, SD = 11.00, range = 18-59), including 12,188 women (66.10 %) and 2706 (14.67 %) who were seeking psychological care. A web-based application included two multidimensional screening scales to evaluate depression, anxiety and somatic symptoms and related distress/dysfunction, as well as past and current ShSTB. Based on the participants' sex, the entire sample was randomly divided into two sub-samples to compare and replicate the Confirmatory Factor Analysis (CFA) results, getting evidence of the multidimensionality of the scales. With the two sub-samples, we also tested the nested models from a structural equation model (SEM) to suggest a relationship between mental health and self-harm/suicide variables. FINDINGS: Our findings suggest that 31 % of participants were at risk for depression, 42.30 % for anxiety, 38.30 % for Marked Distress, Dysfunction and Somatization (MDDS), 33.30 % for at least one ShSTB, and 4.20 % for Previous Self Harm Thoughts and Behaviors (PShTB) during the COVID-19 pandemic. A greater percentage of women and participants seeking psychological care showed high levels of mental health symptoms, PShTB, MDDS, and ShSTB. The path model suggested a direct influence of PShTB and MDDS on ShSTB. Depression symptoms lead to ShSTB in three possible ways: through PShTB, PShTB affecting MDDS, and generalized anxiety affecting MDDS. DISCUSSION AND OUTLOOK: The pandemic was accompanied by a high prevalence of depression-anxiety, marked distress, dysfunction and somatization and self-harm/suicide thoughts and behaviors. The findings of this study suggest evidence over the well-known association between depression and anxiety, and between depression, previous self-harm thoughts and behaviors, and self-harm/suicide. The evidence suggests to distinguish when participants were suffering from MDDS and anxious depression from those only suffering from depression. The methodological conditions of the study suggest a comprehensive model of ShSTB prevention. Findings also suggest the need to care for Mexicans with depressive symptoms and PShTB as well as those suffering from anxious depression with MDDS to prevent suicide, by implementing effective public health policies and preventive strategies to reduce the mental health gap during health emergencies. LIMITATIONS: This research was a cross-sectional study, suggesting that future analyses should focus on the evaluation of its consistency with confirmed diagnoses of mental health disorders, self-harm/suicide risks, and the effect of remote psychological help to address these problems.

A retrospective study of Cerebrolysin in patients with moderate to severe traumatic brain injury: Cognitive and functional outcomes.

In this retrospective study, we aimed to evaluate the effects of the neurotrophic compound Cerebrolysin on executive, cognitive, and functional performance in patients with traumatic brain injury (TBI) with a highly severe disability level. A total of 44 patients were included in the study, with 33 patients in the control group and 11 patients in the interventional group who received intravenous infusions of 30 mL Cerebrolysin. Both groups received standard rehabilitation therapy following the rehabilitation protocol for patients with TBI at Hospital Clínico Mutual de Seguridad. Functional and cognitive scales were evaluated at baseline, at four months, and at the endpoint of the intervention therapy at seven months (on average). The results revealed a significant improvement in the Cerebrolysin-treated group compared to the control group. Specifically, patients who received Cerebrolysin showed a moderate residual disability and a significant reduction in the need for care. Concerning the promising results and considering the limitations of the retrospective study design, we suggest that randomized controlled studies be initiated to corroborate the positive findings for Cerebrolysin in patients with moderate to severe brain trauma.

Nuevo paradigma en la cirugía del mioma: reparación uterina / New paradigm in fibroid surgery: Uterine repair

Los miomas uterinos son una patología frecuente que afecta fundamentalmente a mujeres en su tercera y cuarta década de su vida. La mayoría son asintomáticos. Sin embargo, algunos pueden tener una importante repercusión clínica o en la fertilidad de la paciente. Recientemente se han producido cambios relevantes en el diagnóstico y manejo de esta entidad. En este manuscrito se pretende resumir dichos cambios abordados en el 1er Congreso Nacional de la Sociedad Española para el estudio de las Miomas y Endometriosis.(AU)

Uterine fibroids are a frequent pathology that mainly affects women in their third and fourth decade of life. Most are asymptomatic. However, some may have a significant clinical impact or on the fertility of the patient. Recently there have been relevant changes in the diagnosis and management of this entity. This paper aims to summarize these changes discussed at the 1 st National Congress of the Spanish Society for the Study of Fibroids and Endometriosis.(AU)

Interpersonal and Intimate Violence in Mexican Youth: Drug Use, Depression, Anxiety, and Stress during the COVID-19 Pandemic.

The COVID-19 pandemic may have increased interpersonal and intimate violence, harmful use of alcohol and other drugs (AODs), and mental health problems. This study uses a valid path model to describe relationships between these conditions of young Mexicans during the second year of the pandemic. A sample of 7420 Mexicans ages 18 to 24-two-thirds of whom are women-completed the Life Events Checklist, the Alcohol, Smoking, and Substance Involvement Screening Test, the Major Depressive Episode Checklist, the Generalized Anxiety Scale, and the Post-traumatic Stress Disorder (PTSD) Checklist. Young Mexicans reported higher rates of victimization and perpetration of interpersonal and intimate violence and mental health symptomatology than those noted pre- and in the first year of the pandemic. The harmful use of AOD rates were similar to those reported by adolescents before. The findings suggest asymmetric victimization and perpetration of intimate violence by gender (with women at a higher risk). More men than women have engaged in the harmful use of AODs (except for sedatives, which more women abuse). More women than men were at risk of all mental health conditions. The path model indicates that being a victim of intimate violence predicts the harmful use of tobacco, alcohol, cocaine, and sedatives, depression, anxiety, and specific PTSD symptoms (such as re-experimentation and avoidance symptoms). Being a victim of interpersonal violence resulted in severe PTSD symptoms (including avoidance, negative alterations in cognition-mood, and hyperarousal signs). The harmful use of sedatives predicted depressive symptoms. Men's victimizing intimate violence model contrasted with that of women, which included being the victim of interpersonal violence and severe PTSD symptoms. The high school youth model had three paths: victimizing intimate violence, victimizing interpersonal abuse, and sedative use, which predicted depression. Our findings could serve as the basis for future studies exploring the mechanisms that predict violence to develop cost-effective preventive programs and public policies and to address mental health conditions during community emergencies.

Online Training for Primary Care Staff: Skills development on the Mental Health Gap Action Programme (mhGAP) Intervention Guide / Entrenamiento en línea para personal de atención primaria: Desarrollo de habilidades sobre la Guía de Intervención para Superar las Brechas en Salud Mental (mhGAP)

Abstract Developing effective learning strategies to strengthen mental health professionals' capacities and deliver evidence-based interventions in their communities is urgent. We developed and evaluated an online training program for the Intervention Guide for Mental, Neurological and Substance Use Disorders in Non-specialized Health Settings. Nine hundred and seventy-five health professionals in Mexico were enrolled in the training program, during the period of social distancing brought about by the COVID-19 pandemic. Participants completed a pre-post online evaluation strategy including Knowledge screening, assessment of Learning Activities, and performance in Programmed-Simulated cases to evaluate knowledge and skills for the assessment, management, and follow-up of Mental, Neurological and Substance Use Disorders. We found that participants improved their knowledge and skills from training on the mhGAP online course. Notably we observed these positive results regardless of sex, profession, institution, or social vulnerability rating of participants, suggesting that this is a relevant training program for primary care staff. These results contribute to the Mental Health Gap Action Programme and advance the use of online teaching and evaluation technologies in this field.

Resumen El desarrollo de estrategias efectivas de aprendizaje para fortalecer las competencias de los profesionales de la salud mental y brindar intervenciones basadas en evidencia en sus comunidades es necesario. El objetivo del presente trabajo fue desarrollar y evaluar un programa de entrenamiento en línea para la Guía de Intervención en Trastornos Mentales, Neurológicos y por Uso de Sustancias en nivel de atención de salud no especializada. Participaron 975 profesionales de la salud mexicanos durante el período de distanciamiento social provocado por la pandemia de COVID-19. Los participantes completaron una evaluación previa y posterior que incluyó un cuestionario de conocimientos, actividades de aprendizaje y la ejecución en casos simulados programados para evaluar el conocimiento y las habilidades para la evaluación, el manejo y el seguimiento de los trastornos mentales, neurológicos y por uso de sustancias. Los resultados indicaron que los participantes mejoraron sus conocimientos y habilidades en función de su participación en el curso en línea, independientemente del sexo, la profesión, la institución o la vulnerabilidad social de los participantes, sugiriendo que se trata de un programa de formación relevante para el personal de atención primaria. Los resultados contribuyen al Programa de Acción para la Brecha de Salud Mental y promueven el uso de tecnologías de evaluación y enseñanza en línea en este campo.

Application of machine learning to predict reduction in total PANSS score and enrich enrollment in schizophrenia clinical trials.

Clinical trial efficiency, defined as facilitating patient enrollment, and reducing the time to reach safety and efficacy decision points, is a critical driving factor for making improvements in therapeutic development. The present work evaluated a machine learning (ML) approach to improve phase II or proof-of-concept trials designed to address unmet medical needs in treating schizophrenia. Diagnostic data from the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) trial were used to develop a binary classification ML model predicting individual patient response as either "improvement," defined as greater than 20% reduction in total Positive and Negative Syndrome Scale (PANSS) score, or "no improvement," defined as an inadequate treatment response (<20% reduction in total PANSS). A random forest algorithm performed best relative to other tree-based approaches in model ability to classify patients after 6 months of treatment. Although model ability to identify true positives, a measure of model sensitivity, was poor (<0.2), its specificity, true negative rate, was high (0.948). A second model, adapted from the first, was subsequently applied as a proof-of-concept for the ML approach to supplement trial enrollment by identifying patients not expected to improve based on their baseline diagnostic scores. In three virtual trials applying this screening approach, the percentage of patients predicted to improve ranged from 46% to 48%, consistently approximately double the CATIE response rate of 22%. These results show the promising application of ML to improve clinical trial efficiency and, as such, ML models merit further consideration and development.

Generation of Distinct Patterns of Rheumatoid Arthritis Autoantigens by Peptidylarginine Deiminase Types 2 and 4 During Perforin-Induced Cell Damage.

OBJECTIVE: To address the independent roles of peptidylarginine deiminase type 2 (PAD2) and PAD4 in generating rheumatoid arthritis (RA) autoantigens by using a system that mimics intracellular citrullination in the RA joint. METHODS: PAD2- or PAD4-expressing 293T cells and mock-transfected cells were used as targets in cytotoxic assays using lymphokine-activated killer cells, cytotoxic YT cell granule contents, or purified human perforin. Protein citrullination and autoantigen production were determined by immunoblotting using the anti-modified citrulline-Senshu method and RA sera (n = 30), respectively. RESULTS: RA sera recognized at least 3 categories of autoantigens in PAD-expressing target cells killed by the cytotoxic lymphocyte granule-induced death pathway. These included: 1) autoantigens targeted in their native form, 2) citrullinated antigens, and 3) antigens cleaved by cytotoxic proteases (e.g., granzymes). Interestingly, although target cells expressing PAD2 or PAD4 showed prominent hypercitrullination of a broad range of proteins during cytotoxic granule-induced cell damage, autoantibodies in RA sera targeted only a very limited number of antigens in hypercitrullinated cells. Furthermore, RA sera showed distinct reactivities to autoantigens generated by PAD2 or PAD4. CONCLUSION: The cytotoxic granule-induced death pathway has the capacity to modify antigens by inducing hypercitrullination and antigen cleavage in target cells. Interestingly, among a large number of citrullinated proteins generated by PAD2 and PAD4 in cells, only a few are likely involved in the production of autoantibodies in RA.

Prediction of Nephropathy in Type 2 Diabetes: An Analysis of the ACCORD Trial Applying Machine Learning Techniques.

Applying data mining and machine learning (ML) techniques to clinical data might identify predictive biomarkers for diabetic nephropathy (DN), a common complication of type 2 diabetes mellitus (T2DM). A retrospective analysis of the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial was intended to identify such factors using ML. The longitudinal data were stratified by time after patient enrollment to differentiate early and late predictors. Our results showed that Random Forest and Simple Logistic Regression methods exhibited the best performance among the evaluated algorithms. Baseline values for glomerular filtration rate (GFR), urinary creatinine, urinary albumin, potassium, cholesterol, low-density lipoprotein, and urinary albumin to creatinine ratio were identified as DN predictors. Early predictors were the baseline values of GFR, systolic blood pressure, as well as fasting plasma glucose (FPG) and potassium at month 4. Changes per year in GFR, FPG, and triglycerides were recognized as predictors of late development. In conclusion, ML-based methods successfully identified predictive factors for DN among patients with T2DM.

Early Systemic Alterations in Severe Spinal Cord Injury: An Experimental Study on the Impact of Injury Level on Renal Function.

STUDY DESIGN: An experimental model of spinal cord injury (SCI) intended to characterize changes in renal function. OBJECTIVE: The aim of this study was to evaluate the possible influence of SCI level on renal function during spinal shock. SUMMARY OF BACKGROUND DATA: SCI triggers multiple systemic and metabolic alterations. Among them, renal dysfunction stands out. Although several variables have been related to its extent, the impact of the cord injury level on renal function has not been clearly stated, particularly during the spinal shock. METHODS: Anesthetized adult Sprague-Dawley rats were subjected to severe spinal cord contusion at low (T8) and high (T1) thoracic levels using the weight-drop method. Glomerular filtration rate (GFR) and tubular secretion (TS) were estimated 24 hours after injury, using a validated method based on the determination of plasma concentrations of iopamidol and p-aminohippuric acid by high-performance liquid chromatography. RESULTS: GFR, fell to 33% (95% CI [24%, 43%]) and 10% (8%, 13%) of the sham-injured controls, whereas TS, decreased to 59% (95% CI [47%, 71%]), and 25% (18%, 32%) of the sham-injured controls, in T8 and T1 injury levels, respectively. Comparisons between cords injured and control rats, as well as between low and high-injured levels, were statistically significant (P < 0.01). CONCLUSION: Renal dysfunction occurs early after severe SCI. The damage is greater in high compared to low injuries. These findings could have important implications in the acute management of patients with high thoracic and cervical injuries, especially in pharmacotherapy using drugs eliminated by the kidney. LEVEL OF EVIDENCE: N/A.

Impact of a brief intervention programs in clinical practice: Barriers and adaptations.

INTRODUCTION: The present study analyzes the main barriers and adaptations to brief interventions that focus on addictive behavior treatments carried out in clinical settings by 756 health professionals during their adoption process in 350 Primary Attention Units in Mexico. METHOD: A descriptive cross-sectional study was conducted and consisted in the application of an instrument that explored diverse aspects, such as knowledge about evidence based brief intervention (BI) programs, barriers during the execution, and adaptations of the BI. RESULTS: the main barriers were related to the implementation of sessions and the user's characteristics such as educational level. As a consequence, the main adaptations were related to the increase in the number of sessions, modifying their length and changing the sequence as well as the proposed material in the manuals. CONCLUSIONS: We discuss the possibility of systematizing the adaptations made by health professionals in order to evaluate their effectiveness.

INTRODUCCIÓN: Este estudio analiza las barreras y adaptaciones realizadas en la práctica por 756 profesionales de la salud a Intervenciones breves para conductas adictivas durante el proceso de transferencia y adopción en 350 Unidades de Atención Primaria de México. MÉTODO: Estudio descriptivo transeccional en el cual se aplicó un instrumento que exploró los conocimientos sobre las IB basadas en evidencia, barreras en la implementación y adaptaciones realizadas a las IB. RESULTADOS: las principales barreras son las relacionadas con la impartición de las sesiones y características de los usuarios como el nivel de escolaridad y por tanto, las principales adaptaciones tienen que ver con mayor número de sesiones, cambios en la duración y en el orden de las mismas así como en los materiales que se proponen en los manuales. CONCLUSIÓN: Se analiza la posibilidad de sistematizar las adaptaciones realizadas por los profesionales de la salud para evaluar su eficacia.

The Gpn3 Q279* cancer-associated mutant inhibits Gpn1 nuclear export and is deficient in RNA polymerase II nuclear targeting.

Gpn3 is required for RNA polymerase II (RNAPII) nuclear targeting. Here, we investigated the effect of a cancer-associated Q279* nonsense mutation in Gpn3 cellular function. Employing RNAi, we replaced endogenous Gpn3 by wt or Q279* RNAi-resistant Gpn3R in epithelial model cells. RNAPII nuclear accumulation and transcriptional activity were markedly decreased in cells expressing only Gpn3R Q279*. Wild-type Gpn3R localized to the cytoplasm but a fraction of Gpn3R Q279* entered the cell nucleus and inhibited Gpn1-EYFP nuclear export. This property and the transcriptional deficit in Gpn3R Q279*-expressing cells required a PDZ-binding motif generated by the Q279* mutation. We conclude that an acquired PDZ-binding motif in Gpn3 Q279* caused Gpn3 nuclear entry, and inhibited Gpn1 nuclear export and Gpn3-mediated RNAPII nuclear targeting.

Human Gpn1 purified from bacteria binds guanine nucleotides and hydrolyzes GTP as a protein dimer stabilized by its C-terminal tail.

The essential GTPase Gpn1 mediates RNA polymerase II nuclear targeting and controls microtubule dynamics in yeast and human cells by molecular mechanisms still under investigation. Here, we purified human HisGpn1 expressed as a recombinant protein in bacteria E. coli BL-21 (DE3). Affinity purified HisGpn1 eluted from a size exclusion column as a protein dimer, a state conserved after removing the hexa-histidine tail and confirmed by separating HisGpn1 in native gels, and in dynamic light scattering experiments. Human HisGpn1 purity was higher than 95%, molecularly monodisperse and could be concentrated to more than 10 mg/mL without aggregating. Circular dichroism spectra showed that human HisGpn1 was properly folded and displayed a secondary structure rich in alpha helices. HisGpn1 effectively bound GDP and the non-hydrolyzable GTP analogue GMPPCP, and hydrolyzed GTP. We next tested the importance of the C-terminal tail, present in eukaryotic Gpn1 but not in the ancestral archaeal Gpn protein, on HisGpn1 dimer formation. C-terminal deleted human HisGpn1 (HisGpn1ΔC) was also purified as a protein dimer, indicating that the N-terminal GTPase domain contains the interaction surface needed for dimer formation. In contrast to HisGpn1, however, HisGpn1ΔC dimer spontaneously dissociated into monomers. In conclusion, we have developed a method to purify properly folded and functionally active human HisGpn1 from bacteria, and showed that the C-terminal tail, universally conserved in all eukaryotic Gpn1 orthologues, stabilizes the GTPase domain-mediated Gpn1 protein dimer. The availability of recombinant human Gpn1 will open new research avenues to unveil the molecular and pharmacological properties of this essential GTPase.

Effect of substance use on condom use in the Theory of Planned Behavior: Analysis of differential item functioning / Efecto del consumo de sustancias en la Teoría de la Conducta Planeada en Uso de Condón: Análisis del funcionamiento diferencial de los ítems

Abstract Introduction. Substance use is one of the factors associated with lower condom use in young adults, which increases the likelihood of HIV infection. The Theory of Planned Behavior (TPB) is one of the most useful models for explaining this phenomenon since it considers the aim of engaging in a behavior based on attitudes, subjective norms and self-efficacy. Objective. To develop a questionnaire and to evaluate the Differential Item Functioning (DIF) caused by substance use in TPB indicators, using the Multiple Indicators Multiple Causes Analysis (MIMIC). Method. The study was conducted in two phases with Mexico City college students age 18 to 25. Results. Adequate goodness of fit was obtained in all three models of the TPB: attitudes χ2S-B(2) = 3.902, p < .001; CFIs = .999; TLIs = .996; RMSEAs = .037, 90% CI ≤ .001-.095; subjective norms χ2S-B(7) = 9.103, p < .245; CFIs = .999; TLIs = .998; RMSEAs = .022, 90% CI ≤ .001-.056; and self-efficacy χ2S-B(25) = 65.115, p < .001; CFIs = .982; TLIs = .974; RMSEAs = .050, 90% CI = .036-.066; in one item in attitudes and two items in subjective norms a DIF effect was observed, while no item proved significant regarding self-efficacy. Discussion and conclusion. There is little evidence in the detection of DIF due to substance use in TPB indicators in condom use, and this is the first study to conduct this type of analysis. Items presenting DIF open the door to future research due to the importance of assessing how the indicator behaves with a population displaying a particular trait.

Resumen Introducción. El consumo de sustancias es uno de los factores asociados a un menor uso de condón en jóvenes adultos, lo cual aumenta la probabilidad de contagio de VIH. La Teoría de la Conducta Planeada (TCP) es uno de los modelos más útiles para explicar este fenómeno ya que considera la intención de llevar a cabo una conducta basándose en actitudes, normas subjetivas y autoeficacia. Objetivo. Desarrollar un cuestionario y evaluar el Funcionamiento Diferencial de los Ítems (DIF) ocasionado por el consumo de sustancias en los indicadores de la TCP, utilizando el análisis Múltiples Ítems Múltiples Causas (MIMIC). Método. El estudio se llevó a cabo en dos etapas con estudiantes universitarios de 18 a 25 años de la Ciudad de México. Resultados. Se obtuvo una adecuada bondad de ajuste en los tres modelos de la TCP: actitudes χ2S-B(2) = 3.902, p < .001; CFIs = .999; TLIs = .996; RMSEAs = .037, 90% IC ≤ .001-.095; normas subjetivas χ2S-B(7) = 9.103; p < .245; CFIs = .999; TLIs = .998; RMSEAs = .022, 90% IC ≤ .001-.056; y autoeficacia χ2S-B(25) = 65.115; p < .001; CFIs = .982; TLIs = .974; RMSEAs = .050, 90% IC = .036-.066; un ítem en actitudes y 2 ítems en normas subjetivas se observó un efecto DIF, y en autoeficacia ningún ítem salió significativo. Discusión y conclusión. Existe poca evidencia en la detección de DIF por uso de sustancias en los indicadores de la TCP en uso de condón, siendo éste el primer estudio que lleva a cabo este tipo de análisis. Los ítems que presenten DIF abren la puerta a futuras investigaciones, debido a la importancia de evaluar cómo se comporta el indicador con una población que tenga un rasgo en particular.

A novel, simple and inexpensive procedure for the simultaneous determination of iopamidol and p-aminohippuric acid for renal function assessment from plasma samples in awake rats.

The purpose of the current study was to design, validate and implement a novel analytical method for the simultaneous plasma measurement of iopamidol and p-aminohippuric acid (PAH) to estimate renal function in awake rats. A reverse-phase high performance liquid chromatographic (RP-HPLC) method for the simultaneous measurement of iopamidol (for glomerular filtration rate estimation, GFR) and PAH (for tubular secretion determination, TS) was designed and validated using a C-18 column, 0.1M acetic acid-10% acetonitrile (90:10, v/v) as mobile phase, at a flow rate of 0.3 ml/min, and UV detection at 270 nm. Iopamidol (244.8 mg/kg) was administered intravenously followed immediately by sodium PAH (100 mg/kg) to healthy female Sprague-Dawley rats. Plasma samples obtained at 2.5, 5, 10, 15, 20, 30, 45, 60, 90, and 120 min after drug administration were deproteinized with 2.5% trichloroacetic acid containing p-aminobenzoic acid as internal standard, and separated by the validated RP-HPLC method described above. The iopamidol and PAH chromatographic data were analyzed using a non-compartmental model. The results demonstrated that the RP-HPLC method was linear in ranges between 15-120 µg/ml and 2.5-120 µg/ml for iopamidol and PAH, respectively. Precision and accuracy were within 15% for both drugs. Recovery of iopamidol and PAH was 92% and 100%, respectively. Plasma iopamidol and PAH clearances in awake rats, estimates for GFR and TS, respectively, were 1.49±0.20 ml/min and 3.73±0.38 ml/min. In conclusion, the method here described is a simple and reliable procedure, for the simultaneous and time-saving determination of GFR and TS from plasma samples in the conscious rat.

Immune-mediated pore-forming pathways induce cellular hypercitrullination and generate citrullinated autoantigens in rheumatoid arthritis.

Autoantibodies to citrullinated protein antigens are specific markers of rheumatoid arthritis (RA). Although protein citrullination can be activated by numerous stimuli in cells, it remains unclear which of these produce the prominent citrullinated autoantigens targeted in RA. In these studies, we show that RA synovial fluid cells have an unusual pattern of citrullination with marked citrullination of proteins across the broad range of molecular weights, which we term cellular hypercitrullination. Although histone citrullination is a common event during neutrophil activation and death induced by different pathways including apoptosis, NETosis, and necroptosis/autophagy, hypercitrullination is not induced by these stimuli. However, marked hypercitrullination is induced by two immune-mediated membranolytic pathways, mediated by perforin and the membrane attack complex (MAC), which are active in the RA joint and of importance in RA pathogenesis. We further demonstrate that perforin and MAC activity on neutrophils generate the profile of citrullinated autoantigens characteristic of RA. These data suggest that activation of peptidylarginine deiminases during complement and perforin activity may be at the core of citrullinated autoantigen production in RA. These pathways may be amenable to monitoring and therapeutic modulation.