Source-Sink Dynamics in a Two-Patch SI Epidemic Model with Life Stages and No Recovery from Infection.

This study presents a comprehensive analysis of a two-patch, two-life stage SI model without recovery from infection, focusing on the dynamics of disease spread and host population viability in natural populations. The model, inspired by real-world ecological crises like the decline of amphibian populations due to chytridiomycosis and sea star populations due to Sea Star Wasting Disease, aims to understand the conditions under which a sink host population can present ecological rescue from a healthier, source population. Mathematical and numerical analyses reveal the critical roles of the basic reproductive numbers of the source and sink populations, the maturation rate, and the dispersal rate of juveniles in determining population outcomes. The study identifies basic reproduction numbers R 0 for each of the patches, and conditions for the basic reproduction numbers to produce a receiving patch under which its population. These findings provide insights into managing natural populations affected by disease, with implications for conservation strategies, such as the importance of maintaining reproductively viable refuge populations and considering the effects of dispersal and maturation rates on population recovery. The research underscores the complexity of host-pathogen dynamics in spatially structured environments and highlights the need for multi-faceted approaches to biodiversity conservation in the face of emerging diseases.

Patch Test Results with the Latin American Baseline Series in a Colombian Population. 2016-2021.

Background: Contact dermatitis (CD) is one of the most prevalent skin diseases. It is commonly divided into irritant contact dermatitis (ICD) and allergic contact dermatitis (ACD). Patch testing is a procedure used to support the diagnosis of ACD. This test should be interpreted along with the clinical history and morphology of the skin lesions to determine clinical relevance. Objective: To describe the sensitization patterns of patients undergoing patch testing with the Latin American baseline series. Methods: A single-center retrospective study was performed. For the study, patients older than 18 years with a clinical diagnosis of contact dermatitis, who underwent patch testing using the Latin American baseline series were considered. These tests took place at the Alma Mater Hospital of Antioquia between January 1, 2016, and December 31, 2021. Results: A total of 648 patients were included. Patch tests were positive in 63% of cases, with a mean age of 51.5 years. Around 36.6% had atopy-related diseases. The main occupation was housework (30.7%). The hands were the most affected area in the body (31%). The main allergens were nickel sulfate (34%), sodium tetrachloropalladate (24.2%), and thimerosal (8.0%). Fifteen allergens had a percentage below 1%. Hydrocortisone and budesonide did not yield positive results. Conclusion: Nickel sulfate was the most frequent allergen, and women were the most affected. The information gathered could be useful for adjusting the allergens that should be included in the regional baseline series, taking into account the frequency found.

Patch test in Brazilian children with a clinical diagnosis of atopic dermatitis: a cross-sectional study using an extended patch test battery.

INTRODUCTION: Atopic dermatitis (AD) is a chronic and relapsing inflammatory skin disease mainly affecting children. Similarly, Allergic contact dermatitis (ACD) is an inflammatory skin disease, but unlike AD it results from direct exposure to an external agent. Theoretically, the impaired skin barrier facilitates the penetration of potential allergens. Therefore, AD patients are at risk for an associated ACD, exacerbating their skin condition. Because eczema is similar, performing a patch test (PT) for the differential diagnosis is essential. METHODS: In this cross-sectional transversal study, we performed a PT with 30 sensitizers in 26 children with AD, selected according to established criteria for suspected ACD, and treated at an AD center of a pediatric university hospital in Rio de Janeiro. Clinical presentation, patient profile, main sensitizers, and frequency of ACD caused by therapeutic skincare products were evaluated. RESULTS: In all, 23 (88.5%) patients reacted to at least one allergen, 21 (80.7%) had a relevant positive patch test, and 15 (57.7%) were polysensitized. The main positive sensitizers were nickel (38.5%), blue disperse (30.8%), fragrance mix (30.8%), and neomycin (23.1%). Nineteen (73%) patients reacted to substances present in therapeutic or skincare products. CONCLUSION: Our data underscore the importance of performing a PT in AD children whose eczema has atypical distribution. The expressive percentage of positive tests, especially of allergens in skincare products, indicates the constant need to review the proposed treatments. Therefore, we recommend a specific and expanded PT battery for pediatric AD patients, including a negative control, to increase sensitivity for diagnosing ACD.

Spatial distribution of Triatoma dimidiata peridomestic colonies modulated by distance between susceptible microhabitat patches.

Triatoma dimidiata is a vector of the hemoparasite Trypanosoma cruzi, the causal agent of Chagas disease. It settles reproductive colonies in the peridomicile of the premises. The peridomicile is comprised of a random set of artificial and natural features that overlap and assemble a network of microenvironmental suitable sites (patches) that interact with each other and favor the structure and proliferation of T. dimidiata colonies. The heterogeneity of patch characteristics hinders the understanding and identification of sites susceptible to colonization. In this study, a classification system using a random forest algorithm was used to identify peridomiciles susceptible to colonization to describe the spatial distribution of these sites and their relationship with the colonies of T. dimidiata in ten localities of Yucatan. From 1,000 peridomiciles reviewed, the classification showed that 13.9 % (139) of the patches were highly susceptible (HSP), and 86.1 % (861) were less susceptible (LSP). All localities had at least one HSP. The occupancy by patch type showed that the percentage of total occupancy and by colonies was higher in the HSP, while the occupancy by adult T. dimidiata without evidence of nymphs or exuviae (propagules) was higher in the LSP. A generalized additive model (GAM) revealed that the percentage of occupied patches increases as the abundance of individuals in the localities increases however, the percentage of occupied patches in LSP is lower than occupied in HSP. Distance analyses revealed that colonies and propagules were located significantly closer (approximately 200 m) to a colony in a HSP than any colony in a LSP. The distribution of T. dimidiata in the localities was defined by the distribution of patch type; as the occupancy in these patches increased, a network of peridomestic populations was configured, which may be promoted by a greater abundance of insects inside the localities. These results reveal that the spatial distribution of T. dimidiata individuals and colonies in the peridomicile at the locality scale corresponds to a metapopulation pattern within the localities through a system of patches mediated by distance and level of the vectors' occupancy.

Diagnostic accuracy of patch testing based in clinical response to contact allergen restrictions in allergic contact dermatitis.

Summary: Background. Patch testing (PT) is used to identify substances that cause allergic contact dermatitis (ACD). However, the clinical effects of allergen restrictions following PT have not been thoroughly investigated. This study aims to assess the diagnostic accuracy of PT in patients suspected of having ACD. Methods. Prospective study. PT were performed in patients with clinical diagnosis of ACD. Patients with a positive PT (case group) had a strict restriction of the suspected substance for one month. In patients with negative patch testing (control group), allergen restriction was based in clinical history. Clinical reduction (CR) of at least 50% in disease activity (CR50%) after one month of allergen restriction was considered clinically relevant. Total control was defined as clinical reduction of at least 90% (CR90%). Results. From 400 patients, 66.2% had a positive PT. The sensitivity of PT to identify CR50% was 84%, specificity 47%, PPV 53%, and NPV 81%. Only 10.5% of patients achieved CR90%. Conclusions. The PT had moderate diagnostic accuracy. It could be useful as a screening, but a positive result should be confirmed with controlled allergen restriction. The low number of patients who achieved a 90% CR invites to reconsider the allergens included in PT and the mechanistic processes of the disease.

Evolution of postcanine complexity in Gomphodontia (Therapsida: Cynodontia).

Gomphodonts form a Triassic radiation of small to medium-bodied (<0.5-2.5 m in length) quadrupedal cynodonts characterized by labiolingually expanded gomphodont postcanines. They were the dominant cynodont group in Middle and Late Triassic ecosystems from the Southern Hemisphere and the first predominantly herbivorous cynodonts to evolve. Gomphodonts were also the first therapsids to develop hypsodonty and a dentition with complex occlusal patterns, and their highly diagnostic upper and lower postcanines show many different morphologies. Here, we explored dental complexity in gomphodont cynodonts through time using geographic information system analysis and orientation patch count applied on 3D crown surfaces of upper and lower gomphodont postcanines belonging to 32 gomphodont taxa. This study reveals that the peak in postcanine complexity was reached early in the evolution of gomphodonts with the emergence in the Early Triassic of omnivorous or insectivorous forms with postcanines made of well-separated cusps and cingular cuspules. Traversodontids evolved simpler postcanines via coalescence of cusps into crests and the development of large occlusal basins, and the Middle Triassic radiation of traversodontids led to a sharp decrease in mean postcanine complexity. Simplification of the postcanines in traversodontids is interpreted as being related to a gradual increase in the consumption of plant material. Interestingly, the trend of insectivory/omnivory high postcanine complexity and herbivory low dental complexity in gomphodonts is opposite to the trend of dental complexity reported in some extant mammals, with omnivorous having low dental complexity and herbivorous higher. Postcanine complexity remained relatively stable throughout the evolution of traversodontids and only slightly diminished in the Late Triassic due to the presence of minute forms with particularly simple postcanines in the Rhaetian. The major phylogenetic diversity and taxonomic richness of Gomphodontia are represented in two periods of time: at the end of the Anisian, an age in which the postcanine complexity is simplifying, and at the early Carnian when the postcanine complexity in traversodontids, the only Gomphodontia represented, is stable.

Assessment of risk factors for leakage after repair of perforated peptic ulcer with omental patch. Retrospective study / Evaluación de factores de riesgo de fuga después de la reparación de una úlcera péptica perforada con parche de epiplón. Estudio retrospectivo

Introduction. Perforated peptic ulcer remains one of the critical abdominal conditions that requires early surgical intervention. Leakage after omental patch repair represents one of the devastating complications that increase morbidity and mortality. Our study aimed to assess risk factors and early predictors for incidence of leakage. Methods. Retrospective analysis of data of the patients who underwent omental patch repair for perforated peptic ulcer in the period between January 2019 and January 2022 in Mansoura University Hospital, Egypt. Pre, intra and postoperative variables were collected and statistically analyzed. Incriminated risk factors for leakage incidence were analyzed using univariate and multivariate analysis. Results. This study included 123 patients who met inclusion criteria. Leakage was detected in seven (5.7%) patients. Although associated comorbidities (p=0.01), postoperative intensive care unit admission (p=0.03), and postoperative hypotension (p=0.02) were significant risk factors in univariate analysis, septic shock (p=0.001), delayed intervention (p=0.04), preoperative hypoalbuminemia (p=0.017), and perforation size >5mm (p= 0.04) were found as independent risk factors for leakage upon multivariate analysis. Conclusion. Delayed presentation in septic shock, preoperative hypoalbuminemia, prolonged perforation, operation interval, and large perforation size > 5mm were detected as independent risk factors for leakage. Postoperative tachypnea and tachycardia with increased levels of C-reactive protein and total leucocytic count are alarming signs for incidence of leakage

Introducción. La úlcera péptica perforada es una de las afecciones abdominales críticas que requiere una intervención quirúrgica temprana. La fuga después de la reparación con parche de epiplón representa una de las complicaciones más devastadoras, que aumentan la morbilidad y la mortalidad. Nuestro estudio tuvo como objetivo evaluar los factores de riesgo y los predictores tempranos de fugas. Métodos. Análisis retrospectivo de los datos de los pacientes sometidos a reparación con parche de epiplón por úlcera péptica perforada, en el período comprendido entre enero de 2019 y enero de 2022, en el Hospital Universitario de Mansoura, Egipto. Se recogieron y analizaron estadísticamente variables pre, intra y postoperatorias. Los factores de riesgo asociados a la incidencia de fugas se analizaron mediante análisis univariado y multivariado. Resultados. Este estudio incluyó 123 pacientes que cumplieron con los criterios de inclusión. Se detectó fuga en siete (5,7 %) pacientes. Aunque las comorbilidades asociadas (p=0,01), el ingreso postoperatorio a la unidad de cuidados intensivos (p=0,03) y la hipotensión postoperatoria (p=0,02) fueron factores de riesgo en el análisis univariado, el shock séptico (p=0,001), el retraso en la intervención (p=0,04), la hipoalbuminemia preoperatoria (p=0,017) y el tamaño de la perforación mayor de 5 mm (p=0,04) se encontraron como factores de riesgo de fuga independientes en el análisis multivariado. Conclusión. Se detectaron como factores de riesgo independientes de fuga la presentación tardía en shock séptico, la hipoalbuminemia preoperatoria, la perforación prolongada, el intervalo operatorio y el tamaño de la perforación mayor de 5 mm. La taquipnea posoperatoria y la taquicardia con niveles elevados de proteína C reactiva y recuento leucocitario total son signos de alarma sobre la presencia de fuga.

Perfil de sensibilização de pacientes submetidos ao teste de contato no Instituto Lauro de Souza Lima no período de 2017 a 2023 / Sensitization profile of patients undergoing patch testing at the Lauro de Souza Lima Institute from 2017 to 2023

Introdução: O teste de contato (patch teste) é o padrão ouro para diagnóstico de dermatites alérgicas de contato (DACs), possibilitando a identificação do agente desencadeante. Mudanças nos hábitos de vida e exposição a novos agentes sensibilizantes presentes em medicamentos, cosméticos e outros produtos podem induzir mudanças no perfil de sensibilização da população. Objetivo: Realizar um levantamento do perfil dos pacientes que efetuaram o teste de contato no Instituto Lauro de Souza Lima (ILSL) no período entre 2017 e 2023, bem como a frequência de sensibilização aos elementos testados, para identificar alterações devido à pandemia de COVID-19. Material e Métodos: Foi realizado um estudo retrospectivo no ILSL, analisando os registros dos testes realizados de julho de 2017 a junho de 2023. Parâmetros como sexo, idade, atividade profissional, localização das lesões e sensibilização aos elementos testados da bateria padrão (n=30) e de cosméticos (n=10) foram avaliados. As reações foram classificadas de acordo com as recomendações do International Contact Dermatitis Research Group e os dados foram analisados usando o teste do qui-quadrado. Resultados: O estudo incluiu 738 indivíduos, sendo 67,9% do sexo feminino, com idade média de 45,4 anos. As regiões mais afetadas foram mãos (62,45%), pés (45,99%) e braços (26,58%). 75,80% apresentaram reação positiva a pelo menos uma das 40 substâncias testadas. O sulfato de níquel foi o elemento mais prevalente (35,91%), seguido por cloreto de cobalto (24,12%) e timerosol (15,04%). Na análise da bateria de cosméticos, verificamos maior prevalência de sensibilização ao amerchol L-101 (11,24%), bronopol (3,79%) e tonsilamida (3,11%). A sensibilização ao amerchol L-101 mostrou-se crescente a partir de 2020 com maior incidência em 2021 e permaneceu elevada até o final do período avaliado. Conclusão: O perfil de sensibilização a substâncias da bateria padrão no ILSL permaneceu semelhante ao observado em estudo anterior. Entretanto, houve um aumento na sensibilização ao amerchol L-101 no período da pandemia de COVID-19 o que pode estar associado a mudança de hábitos de higiene como aumento da frequência de lavagem de mãos e uso de produtos antissépticos

ABSTRACT: Patch testing is considered the gold standard for the diagnosing allergic contact dermatitis (ACD) and allows the identification of triggering allergens. Changes in lifestyle as well as exposure to new sensitizers present in medications, cosmetics, and other products, may induce changes in the sensitization profile of the population. Objective: To investigate the sensitization profile of patients who underwent patchtesting at the Lauro de Souza Lima Institute (ILSL) between 2017 and 2023, and the frequency of sensitization to the elements tested, to identify changes due to the COVID-19 pandemic. Materials and Methods: A retrospective study was conducted at the ILSL, analyzing medical records of tests performed from July 2017 to June 2023. Parameters such as sex, age, occupation, location of the lesion, and sensitization to the elements of the standard battery (n=30) and the cosmetic battery (n=10) were evaluated. Reactions were classified according to the recommendations of the International Contact Dermatitis Research Group, and the data were analyzed using the chi-squared test. Results: The study included 738 subjects, 67.9% female, mean age 45.4 years. The most commonly affected areas were the hands (62,4%), feet (46.0%), and arms (26.6%). 75.8% had a positive reaction to at least one of the 40 substances tested. Nickel sulfate was the most prevalent element (35.9%), followed by cobalt chloride (24.1%) and thimerosal (15.0%). Regarding the cosmetic battery, we found a higher prevalence of sensitization to amerchol L-101 (11.2%), bronopol (3.8%), and tonsilamide (3.1%). There was an increasing trend for sensitization to amerchol L-101 from 2020 onwards, reaching a peaking in 2021 and remaining at an elevated level until the end of the evaluated period. Conclusion: The sensitization profile to the standard series at ILSL remained similar to that observed in a previous study. However, there was an increase in sensitization to amerchol L-101 during the pandemic period, possibly related to changes in hygiene habits such as increased hand washing and the use of antiseptic products

Hipotensión intracraneal espontánea. Una puesta al día

Introducción: La hipotensión intracraneal espontánea es un síndrome causado por la disminución del volumen de líquido cefalorraquídeo consecuencia de su fuga al espacio extradural. Aunque la ICHD-3 proporciona un alto nivel de especificidad diagnóstica, esta enfermedad puede manifestarse de forma atípica. Hasta en un 30% no es posible establecer el punto de escape, pero con el refinamiento de los exámenes de imágenes este porcentaje se ha reducido a un 15%-20%. Actualmente, su manejo no se encuentra estandarizado y las recomendaciones se basan en evidencia de limitada calidad metodológica, además de la variabilidad de protocolos entre distintos centros. Desarrollo En esta revisión actualizamos los procedimientos diagnósticos y terapéuticos. Por un lado, analizamos el rol de la resonancia nuclear magnética de encéfalo y médula espinal completa como primer paso diagnóstico y, por otro lado, señalamos los exámenes destinados a determinar la fuga de líquido cefalorraquídeo. Tal es el caso de la mielo-resonancia, la mielo-tomografía computarizada, tanto estándar, dinámica y por sustracción digital, además de la cisternografía con 111-Indium-DPTA. Sin embargo, determinar cuál de estos exámenes es el óptimo es objeto de debate. Lo mismo ocurre con el tratamiento: reposo; parche sanguíneo epidural a ciegas, parche guiado por fluoroscopia o tomografía computarizada, parche de fibrina; o cirugía. Conclusiones Se requiere de una mayor investigación, especialmente con trabajos multicéntricos controlados, para una mejor comprensión de la fisiopatología, el diagnóstico por imágenes, los enfoques terapéuticos y evaluación objetiva de los resultados clínicos. Solo así se establecerán pautas diagnósticas y de tratamiento validadas.

Introducction: Spontaneous intracranial hypotension is a syndrome caused by decreased CSF volume secondary to its leakage into the extradural space Although ICHD-3 provides a high level of diagnostic specificity, manifestations may be atypical, making diagnosis challenging. The site of leakage may be undetermined in point Up to 30% of cases, although with recent refinement of imaging, this percentage has been reduced to 15-20%. Currently, management is not standardized and recommendations are based on inconclusive evidence, with variability of protocols between centres. Development. In this review, we update diagnostic and therapeutic procedures. We analyse the role of whole brain and spinal cord MRI as a first investigation and review tests aimed at determining cerebrospinal fluid leakage, such as MRI myelography, conventional CT myelography, dynamic CT myelography, and digital subtraction CT myelography, as well as 111-Indium-DPTA cisternography. Determining optimal use of these investigations remains a matter of debate. The same is true for treatment: rest, blind epidural blood patch, fluoroscopy or CT-guided epidural blood patch, fibrin patch and surgery are discussed. Conclusión: Further research, especially multicentre controlled studies, is required to improve understanding of pathophysiology, diagnostic imaging, therapeutic approaches and to objectively assess clinical outcomes. Only then will diagnostic and treatment guidelines be evidence-based.

Microvascular decompression using autologous muscle graft for trigeminal neuralgia: a case series and meta-analysis.

PURPOSE: We aimed to describe a case series of patients diagnosed with trigeminal neuralgia (TN) who were submitted to microvascular decompression (MVD) using autologous muscle graft (AMG) and perform a systematic review and meta-analysis. METHODS: Forty-four adult patients who underwent MVD using AMG between 2012 and 2022 were studied retrospectively. Demographic, clinical, and surgical factors were assessed. We systematically reviewed PubMed, Embase, and Cochrane Library from inception to May 2023. We used random-effects model for all outcomes. Heterogeneity was assessed with I2. We used R software 4.3.1 for all statistical analyses. RESULTS: Among patients in the case series, the mean age was 52 ± 12.9 years, and the proportion of females was 65.9%. Forty-one patients (93.2%) presented complete pain relief after a mean follow-up of 7.7 years. The pooled analysis of immediate pain relief was 91.3% (95% CI 82-96%; I2=78%). The good pain relief during follow-up was 88.2% (95% CI 78-94%; I2=80%) at follow-up. The recurrence rates at 6, 12, 36 months, and during follow-up were 6.2%, 10.5%, 10.3%, and 11%, respectively. CONCLUSION: In this case series and meta-analysis of over 440 patients, our findings suggest that the practice of MVD using AMG may be an efficient option in the short term as surgical treatment for TN. Further trials should compare AMG with other materials and its effectiveness in a long-term follow-up.

Ouabain's Influence on TRPV4 Channels of Epithelial Cells: An Exploration of TRPV4 Activity, Expression, and Signaling Pathways.

Ouabain, a substance originally obtained from plants, is now classified as a hormone because it is produced endogenously in certain animals, including humans. However, its precise effects on the body remain largely unknown. Previous studies have shown that ouabain can influence the phenotype of epithelial cells by affecting the expression of cell-cell molecular components and voltage-gated potassium channels. In this study, we conducted whole-cell clamp assays to determine whether ouabain affects the activity and/or expression of TRPV4 channels. Our findings indicate that ouabain has a statistically significant effect on the density of TRPV4 currents (dITRPV4), with an EC50 of 1.89 nM. Regarding treatment duration, dITRPV4 reaches its peak at around 1 h, followed by a subsequent decline and then a resurgence after 6 h, suggesting a short-term modulatory effect related to on TRPV4 channel activity and a long-term effect related to the promotion of synthesis of new TRPV4 channel units. The enhancement of dITRPV4 induced by ouabain was significantly lower in cells seeded at low density than in cells in a confluent monolayer, indicating that the action of ouabain depends on intercellular contacts. Furthermore, the fact that U73122 and neomycin suppress the effect caused by ouabain in the short term suggests that the short-term induced enhancement of dITRPV4 is due to the depletion of PIP2 stores. In contrast, the fact that the long-term effect is inhibited by PP2, wortmannin, PD, FR18, and IKK16 suggests that cSrc, PI3K, Erk1/2, and NF-kB are among the components included in the signaling pathways.

INNOVATIVE TECHNIQUES AND NEW INSIGHTS: Studying cardiac ionic currents and action potentials in physiologically relevant conditions.

Cardiac arrhythmias are associated with various forms of heart diseases. Ventricular arrhythmias present a significant risk for sudden cardiac death. Atrial fibrillations predispose to blood clots leading to stroke and heart attack. Scientists have been developing patch-clamp technology to study ion channels and action potentials (APs) underlying cardiac excitation and arrhythmias. Beyond the traditional patch-clamp techniques, innovative new techniques were developed for studying complex arrhythmia mechanisms. Here we review the recent development of methods including AP-Clamp, Dynamic Clamp, AP-Clamp Sequential Dissection, and Patch-Clamp-in-Gel. These methods provide powerful tools for researchers to decipher how the dynamic systems in excitation-Ca2+ signaling-contraction feedforward and feedback to control cardiac function and how their dysregulations lead to heart diseases.

Las arritmias cardiacas están asociadas a diferentes tipos de enfermedad cardiaca. Las arritmias ventriculares constituyen un alto riesgo de muerte súbita. La fibrilación auricular predispone a coágulos sanguíneos que pueden producir accidentes cerebrovasculares e infarto miocárdico. Los científicos han desarrollado la técnica de patch-clamp para estudiar los canales iónicos y los potenciales de acción (PAs), que constituyen la base de la excitación y las arritmias cardiacas. Además de las clásicas técnicas de patch-clamp, se desarrollaron técnicas innovativas para estudiar los mecanismos complejos de las arritmias. En este trabajo, describimos diferentes métodos recientemente desarrollados tales como AP-clamp ("clampeo" del PA), Dynamic Clamp ("clampeo" dinámico), AP-Clamp Sequential Dissection, (disección secuencial del "clampeo" del AP), y Patch-Clamp-in-Gel (Patch clamp en gel). Estos métodos constituyen herramientas poderosas para descifrar cómo los sistemas dinámicos que constituyen la excitación-las señales de Ca2+ y la contracción, se retroalimentan para controlar la función cardiaca y cómo sus alteraciones llevan a la enfermedad cardiaca.

Estado actual de la cefalea postpunción meníngea en un hospital colombiano / Status of post-dural puncture headache in a Colombian hospital

Introducción: La cefalea postpunción meníngea (CPPM) posterior a la anestesia raquídea es una de las complicaciones más frecuentes asociadas a factores intrínsecos del paciente y de la técnica anestésica. Objetivo: Describir la frecuencia y los factores asociados con el desarrollo de la cefalea postpunción meníngea. Materiales y métodos: Serie retrospectiva de pacientes que ingresaron a un hospital de segundo nivel y se les confirmó el diagnóstico de cefalea secundaria a la anestesia raquídea. Resultados: Serie de 49 casos, 88 % de sexo femenino y 12 % de sexo masculino, con una edad media de 27,7 años. Los procedimientos quirúrgicos con desenlace de CPPM fueron: cirugías de ginecología y obstetricia (63 %), cirugías de urgencias de otras especialidades (28 %) y cirugías electivas (8 %). La técnica anestésica se realizó con agujas biseladas tipo Quincke calibre 25 gauge (G) en 14%, calibre 26 G 33 % y 27 G 53 %. El 51 % se realizó en posición de sedestación y el 49 % en decúbito lateral izquierdo. El 10% de los casos se manejó con parche hemático, en tanto que el antecedente de migraña se presentó en el 8 %. Discusión: En la actualidad, el uso de agujas con diseño de punta cónica es el estándar de oro, ya que permite obtener resultados confiables y disminuye complicaciones como la CPPM. Conclusión: La CPPM luego de una anestesia espinal se relacionó con factores como la edad (joven), el sexo (femenino) y el uso de agujas biseladas. Los otros factores de riesgo identificados fueron poco concluyentes, aunque no se pueden descartar, debido a la naturaleza de este estudio.

Introduction: Post dural puncture headache (PDPH) following spinal anesthesia is one of the most frequent complications associated with intrinsic patient and anesthetic technique factors. Objective: To describe the frequency and associated factors related to the development of PDPH. Materials and methods: Retrospective series of patients admitted to a second level hospital with a confirmed diagnosis of headache secondary to spinal anesthesia. Results: Series of 49 cases, 88 % female and 12 % male, mean age 27.7 years. The surgical procedures resulting in CPPM were gynecology and obstetrics surgeries 63 %, emergency surgeries of other specialties 28 % and elective surgeries 8 %. The anesthetic technique was performed with beveled needles Quincke type 25 gauge (G) in 14 %, 26 G gauge 33% and 27 G 53 %. In the seated position 51 % and in the left lateral decubitus position 49% were performed. A blood patch was used in 10 % of the cases and a history of migraine was present in 8 %. Discussion: The use of needles with conical tip design is currently the gold standard, they give reliable results and reduce complications such as PDPH. Conclusion: PDPH after spinal anesthesia was related to factors such as age (young), sex (female) and the use of traumatic needles. The other risk factors identified were inconclusive, although they cannot be ruled out due to the nature of this study.

The bacterial tubulin homolog FtsZ generates electrical oscillations.

FtsZ, a major cytoskeletal protein in all bacteria and archaea, forms a ring that directs cytokinesis. Bacterial FtsZ is considered the ancestral homolog of the eukaryotic microtubule (MT)-forming tubulins, sharing GTPase activity and the ability to assemble into protofilaments, rings, and sheets, but not MTs. Previous studies from our laboratory demonstrated that structures of isolated brain MTs spontaneously generate electrical oscillations and bursts of electrical activity similar to action potentials. No information about whether the prokaryotic tubulins may share similar properties is available. Here, we obtained by ammonium sulfate precipitation an enriched protein fraction of the endogenous FtsZ from wild-type Escherichia coli ATCC 25922 without any transfection or overexpression of the protein. As revealed by electron microscopy, FtsZ was detected by dot blot analysis and immunofluorescence that assembled into filaments and sheets in a polymerization buffer. We used the patch-clamp technique to explore the electrical properties of sheets of FtsZ and bacterial cells. Electrical recordings at various holding potentials ranging from ±200 mV showed a complex oscillatory behavior, with several peak frequencies between 12 and 110 Hz in the power spectra and a linear mean current response. To confirm the oscillatory electrical behavior of FtsZ we also conducted experiments with commercial recombinant FtsZ, with similar results. We also detected, by local field potentials, similar electrical oscillations in K+-depolarized pellets of E. coli cultures. FtsZ oscillations had a wider range of frequency peaks than MT sheets from eukaryotic origin. The findings indicate that the bacterial cytoskeleton generates electrical oscillators that may play a relevant role in cell division and unknown signaling mechanisms in bacterial populations.

The diverse family of Cys-loop receptors in Caenorhabditis elegans: insights from electrophysiological studies.

Cys-loop receptors integrate a large family of pentameric ligand-gated ion channels that mediate fast ionotropic responses in vertebrates and invertebrates. Their vital role in converting neurotransmitter recognition into an electrical impulse makes these receptors essential for a great variety of physiological processes. In vertebrates, the Cys-loop receptor family includes the cation-selective channels, nicotinic acetylcholine and 5-hydroxytryptamine type 3 receptors, and the anion-selective channels, GABAA and glycine receptors, whereas in invertebrates, the repertoire is significantly larger. The free-living nematode Caenorhabditis elegans has the largest known Cys-loop receptor family as well as unique receptors that are absent in vertebrates and constitute attractive targets for anthelmintic drugs. Given the large number and variety of Cys-loop receptor subunits and the multiple possible ways of subunit assembly, C. elegans offers a large diversity of receptors although only a limited number of them have been characterized to date. C. elegans has emerged as a powerful model for the study of the nervous system and human diseases as well as a model for antiparasitic drug discovery. This nematode has also shown promise in the pharmaceutical industry search for new therapeutic compounds. C. elegans is therefore a powerful model organism to explore the biology and pharmacology of Cys-loop receptors and their potential as targets for novel therapeutic interventions. In this review, we provide a comprehensive overview of what is known about the function of C. elegans Cys-loop receptors from an electrophysiological perspective.

Analogue signaling of somatodendritic synaptic activity to axon enhances GABA release in young cerebellar molecular layer interneurons.

Axons are equipped with the digital signaling capacity by which they generate and faithfully propagate action potentials (APs), and also with the analogue signaling capacity by which subthreshold activity in dendrites and soma is transmitted down the axon. Despite intense work, the extent and physiological role for subthreshold synaptic activity reaching the presynaptic boutons has remained elusive because of the technical limitation to record from them. To address this issue, we made simultaneous patch-clamp recordings from the presynaptic varicosities of cerebellar GABAergic interneurons together with their parent soma or postsynaptic target cells in young rat slices and/or primary cultures. Our tour-de-force direct functional dissection indicates that the somatodendritic spontaneous excitatory synaptic potentials are transmitted down the axon for significant distances, depolarizing presynaptic boutons. These analogously transmitted excitatory synaptic potentials augment presynaptic Ca++ influx upon arrival of an immediately following AP through a mechanism that involves a voltage-dependent priming of the Ca++ channels, leading to an increase in GABA release, without any modification in the presynaptic AP waveform or residual Ca++. Our work highlights the role of the axon in synaptic integration.

[A drink with an unexpected ending... Adverse reaction by tonic water: A case report]. / Una copa con final inesperado... Reacción adversa por agua tónica: reporte de un caso.

BACKGROUND: Quinine is an alkaloid with antipyretic and anti-infective properties, and also an ingredient in tonic waters. Adverse reactions have been reported with this product, such as photosensitivity, vasculitis, and contact dermatitis. CASE REPORT: A 31-year-old male patient who, after 3-4 hours of consuming "Schweppes®" gin with tonic water, manifested ulcers on the lips and oral cavity, and a fixed erythematous lesion on the second phalanx of the hand, 24 hours later. Skin tests with aeroallergens and food were negative, and 48-hour patch tests were positive (quinine [++] and "Schweppes®" [++]). Based on the test findings, the diagnosis of an adverse reaction to quinine, contained in the tonic water, will be established. CONCLUSIONS: Quinine can be found in other types of foods or medications, so it is important to establish an accurate diagnosis and offer adequate recommendations to the patient with the consumption of this product.

ANTECEDENTES: La quinina es un alcaloide con propiedades antipiréticas, antiinfecciosas y, además, un ingrediente del agua tónica. Se han descrito reacciones adversas con este producto, como fotosensibilidad, vasculitis y dermatitis de contacto. REPORTE DE CASO: Paciente masculino de 31 años, que luego de 3-4 horas de consumir ginebra con agua tónica "Schweppes®" manifestó úlceras en los labios y la cavidad bucal, y una lesión eritematosa fija en la segunda falange de la mano, 24 horas después. Las pruebas cutáneas con aeroalérgenos y alimentos resultaron negativas, y las pruebas epicutáneas de 48 horas positivas (quinina [++] y "Schweppes®" [++]). Con base en los hallazgos de las pruebas, se estableció el diagnóstico de reacción adversa por quinina, contenida en el agua tónica. CONCLUSIÓN: La quinina puede encontrarse en diferentes alimentos o medicamentos, por lo que es importante establecer el diagnóstico preciso y ofrecer recomendaciones adecuadas por el consumo de este producto.

Ruptura prematura de membranas ovulares / Premature rupture of ovular membranes

La ruptura prematura de las membranas ovulares se define como la pérdida de la integridad del amnios y corion antes del inicio del trabajo de parto, afecta el 3 % de los embarazos, causa un tercio de los partos pretérminos, los cuales ocupan el 10,49 % de los nacimientos y es el origen de altos índices de morbimortalidad perinatal. En la actualidad, el manejo de esta patología se orienta principalmente en evitar los factores de riesgo, hacer un diagnóstico adecuado, determinar la edad gestacional en que ocurre, realizar el monitoreo exhaustivo del bienestar materno-fetal y en decidir el momento idóneo de finalización de la gestación para minimizar sus complicaciones. Debido a la compleja y lábil estructura histológica de las membranas ovulares, se ha dejado a un lado el tratamiento directo de la entidad el cual sería sellar o reparar el defecto en sí. En los últimos años, numerosos estudios y protocolos clínicos de prestigiosos centros asistenciales han servido como guía para el manejo de esta entidad, pero en muy pocos se observa una terapia destinada a la reparación de dichas membranas o en sellar tal defecto. Las evidencias científicas demuestran que la regeneración y reparación de las membranas es lenta y compleja y los tratamientos propuestos para reparar o sellar su defecto no han gozado de la aceptación científica para su aprobación, sin embargo, el uso del parche hemático transvaginal endocervical autólogo luce como una alternativa terapéutica prometedora(AU)

The premature rupture of the ovular membranes is defined as the loss of the integrity of the amnion and chorion before the on set of labor, affects 3% of pregnancies, causes athird of preterm births which occupy 10,49% of births and is the origin of high rates of perinatal morbidity and mortality. At present, the management of this pathology is mainly oriented towards avoiding risk factors, making an adequate diagnosis, determining the gestational age in which it occurs, carrying out exhaustive monitoring of maternal-fetal well-being and deciding the ideal moment to end the treatment. Pregnancy to minimizeits complications. Due to the complex and labile histological structure of the ovular membranes, the direct treatment of the entity has been set a side, which would be to seal or repairthe defect it self. In recent years, numerous studies and clinicalprotocols from prestigious health care centers have served as aguide for the management of this entity, but very few have observed a therapy aimed at repairing said membranes or sealing such a defect. Scientific evidence shows that the regeneration and repair of the membranes is slow and complex and the treatment sproposed to repair or seal their defect have not enjoyed scientific acceptance for their approval, how ever, the use of the autologous endocervical transvaginal blood patch looks like a promising therapeutic alternative(AU)

Patch tests and hand eczema: retrospective study in 173 patients and literature review

Abstract Background Hand eczema (HE) is a highly prevalent, recurrent, and multifactorial disease. It encompasses a group of eczematous diseases that affect the hands, etiologically classified into irritant contact dermatitis (ICD), allergic contact dermatitis (ACD) and atopic dermatitis (AD). Few epidemiological studies in Latin America have investigated the characteristics of patients with this condition and the origin of the disease. Objectives To analyze the profile of patients diagnosed with HE submitted to patch tests aiming to determine its etiology. Methods A retrospective descriptive study was carried out on epidemiological data and patch tests of patients with HE treated at a tertiary hospital in the city of São Paulo from January 2013 to December 2020. Results A total of 173 patients were studied, whose final diagnosis was 61.8% of ICD, 23.1% of ACD and 5.2% of AD, with diagnostic overlap in 42.8% of the cases. The main positive and relevant patch tests were: Kathon CG (42%), nickel sulfate (33%), and thiuram mix (18%). Study limitations The number of treated cases and socioeconomic profile was limited to a vulnerable population group. Conclusion HE is a diagnosis in which overlapping etiologies are frequent, with the main sensitizers identified in ACD being Kathon CG, nickel sulfate and thiuram mix.

Use of 5% lidocaine patch in the management of post-traumatic localized neuropathic pain. Case reports / O uso do emplastro de lidocaína a 5% no manejo de dor neuropática localizada pós-traumática. Relato de casos

ABSTRACT BACKGROUND AND OBJECTIVES: Neuropathic pain is defined as a pain caused by a lesion or condition that affects the somatosensory nervous system. Taking its prevalence into account, in particular post-traumatic localized neuropathic pain, and to discuss ways to manage patients with this condition, considering efficacy and tolerability of proposed treatments, this report presents three clinical cases of patients with post-traumatic localized neuropathic pain treated with 5% lidocaine transdermal patch in both monotherapy and polytherapy. CASE REPORTS: This study reports the cases of three female patients aged between 29 and 81 years with complaints of pain due to trauma, who were managed with 5% lidocaine transdermal patch in prolonged treatment, with a significant improvement in pain. CONCLUSION: According to scientific evidence, the use of 5% lidocaine transdermal patch in post-traumatic localized neuropathic pain as shown efficacy with favorable safety and tolerance. Moreover, it was possible to demonstrate that a 5% lidocaine transdermal patch in a polytherapy format has contributed to improved outcomes with no effect in treatment tolerability.

RESUMO JUSTIFICATIVA E OBJETIVOS: A dor neuropática é definida como uma dor provocada por uma lesão ou doença que afeta o sistema nervoso somatossensitivo. Considerando a sua prevalência, em particular dor neuropática localizada pós-traumática, com o intuito de discutir formas de manejar os pacientes portadores dessa condição e avaliando tanto a eficácia quanto a tolerabilidade aos tratamentos propostos, este artigo apresenta três casos clínicos de pacientes portadores dessa condição, tratados com emplastro de lidocaína a 5%, tanto em monoterapia quanto no contexto da terapia multimodal. RELATOS DOS CASOS: Este estudo relata três casos de pacientes do sexo feminino com idades entre 29 e 81 anos e queixas de dor decorrente de trauma, que foram manejadas com emplastro de lidocaína a 5% em tratamento prolongado, com uma significativa melhora do nível de dor. CONCLUSÃO: Em concordância com as evidências da literatura científica, o uso do emplastro de lidocaína a 5% nos casos de dor neuropática localizada pós-traumática relatados mostrou-se eficaz no manejo dessa condição e apresentou perfil de segurança e tolerabilidade favorável. Além disso, foi possível observar também que o emplastro de lidocaína a 5%, quando adicionado em abordagem multimodal, contribuiu para uma melhora no quadro sem prejuízo da tolerabilidade do tratamento.