Sistema glinfático: aspectos anatómicos, fisiológicos e implicaciones clínicas / Glymphatic system: Anatomo-physiological principles and their clinical implications

Introducción: El sistema glinfático comprende el conjunto de rutas perivasculares tanto arteriales como venosas que se encuentran en estrecha asociación con células astrogliales y que permiten la interacción entre el líquido cefalorraquídeo (LCR) y el líquido intersticial cerebral (LIC), para llevar a cabo procesos como la depuración de los metabolitos de desecho celular, o la distribución de nutrientes, así como contribuir al metabolismo cerebral local, la transmisión de volumen y la señalización paracrina cerebral. Contenidos: Este artículo busca profundizar en los conceptos anatómicos y fisiológicos, hasta el momento descritos, sobre este sistema macroscópico de transporte. Se realiza una búsqueda bibliográfica de revisiones y estudios experimentales sobre la anatomía, la fisiología y las implicaciones fisiopatológicas del sistema glinfático. Conclusiones: La identificación anatómica y funcional del sistema glinfático ha ampliado el conocimiento sobre la regulación del metabolismo cerebral en cuanto a distribución de nutrientes y cascadas de señalización celular. Al establecer una interacción entre el espacio subaracnoideo subyacente y el espacio intersticial cerebral, el sistema glinfático surge como uno de los mecanismos protagonistas de la homeostasis cerebral. La disfunción de esta vía hace parte de los mecanismos fisiopatológicos de múltiples trastornos neurológicos, ya sea por la acumulación de macromoléculas, como ocurre en la enfermedad de Alzheimer, o por la reducción del drenaje de sustancias químicas y citocinas proinflamatorias en patologías como la migraña o el trauma craneoencefálico.

Introduction: The glympathic system comprises the set of perivascular routes, arterials or venous, that are found in close relationship with astroglial cells and allow interaction between the cerebrospinal fluid (CSF) and the interstitial brain fluid (ISF), to carry processes like cell-wasting metabolites depuration, nutrients distribution, as well as make a contribution in the local brain metabolism, volumen transmition and brain paracrine signaling. Contents: This article seeks to deepen in the anatomical and physiological concepts, so far described, about this macroscopic transport system. A bibliographic search of reviews and experimental studies on the anatomy, physiology and pathophysiological implications of the glymphatic system is carried out. Conclusions: Anatomical and functional identification of glympathic system has broaden the knowledge about regulation of brain metabolism on the nutrients distribution and cell signaling cascades. When setting an interaction between the subarachnoid space and the brain interstitial space, the glymphatic system arise as one of the leading mechanisms of brain homeostasis. Disfunction of this pathway makes part of the patophysiological mechanisms of multiple neurological disease, either be by collection of macromolecules as in Alzheimer's disease, or by the reduction of inflammatory cytokines and chemical substances drainage as in migraine or traumatic brain injury (TBI).

Meningitis por Listeria: serie de casos en un hospital de tercer nivel y utilidad de las nuevas técnicas de diagnóstico microbiológico / Listeria meningitis: case series in a tertiary level hospital and the usefulness of new microbiological diagnostic techniques

Introducción: La meningitis por Listeria monocytogenes (MLM) es una entidad grave con complicaciones a corto plazo. La reacción de polimerasa en cadena (RPC) puede ayudar a mejorar su diagnóstico y pronóstico. Objetivos: Conocer las características de los pacientes diagnosticados de meningitis por L. monocytogenes en los últimos años, a través de diferentes métodos microbiológicos. Pacientes y Métodos: Serie de casos de pacientes adultos ingresados con MLM en el Hospital Clínico San Carlos, Madrid, España, durante doce años (2009-2021). Se describieron variables epidemiológicas, clínicas, microbiológicas, radiológicas y terapéuticas. Resultados: Se registraron doce pacientes con MLM (edad media 67,5 años, 75% varones). En ocho se obtuvo un cultivo positivo a L. monocytogenes. La RPC en líquido cefalorraquídeo (LCR) fue positiva en los dos casos en los que se realizó la prueba. El tratamiento dirigido en todos los casos fue ampicilina durante 21 días. Se registraron complicaciones en un cuarto de los casos. Del total de pacientes uno falleció. Conclusiones: La MLM es una enfermedad poco frecuente y de difícil diagnóstico. En nuestra serie de casos los dos pacientes diagnosticados por RPC tuvieron resultado de cultivo de LCR negativo, y presentaron buena evolución. La determinación de RPC podría permitir diagnosticar un mayor número de casos y con mayor precocidad.

Background: Listeria monocytogenes meningitis (LMM) is a serious entity with short-term complications. Polymerase chain reaction (PCR) can help to improve its diagnosis and prognosis. Aim: To know the characteristics of patients diagnosed with meningitis by L. monocytogenes in recent years, through different microbiological methods. Methods: Case series of adult patients admitted with LMM at the Hospital Clínico San Carlos of Madrid, Spain, during twelve years (2009-2021). Epidemiological, clinical, microbiological, radiological and therapeutic variables were described. Results: Twelve patients with LMM were recorded (mean age 67.5 years, 75% male). Eight had a positive culture for L. monocytogenes. cerebrospinal fluid (CSF) PCR was positive in the two cases in which the test was performed. Treatment in all cases was ampicillin for 21 days. Complications were recorded in a quarter of the cases. One patient died. Conclusions: LMM is a rare and difficult to diagnose disease. In our series of cases, the two patients diagnosed by PCR had negative CSF culture results, and presented good evolution. PCR determination could allow a greater number of cases to be diagnosed earlier.

Use of cerebrospinal fluid CXCL13 concentration for diagnosis and monitoring of neurosyphilis: a three-case report

Introduction: Previous retrospective studies have demonstrated that the concentration of chemokine ligand CXCL13 in cerebrospinal fluid (CSF-CXCL13) is a promising biomarker in the diagnosis of neurosyphilis and, additionally, in the monitoring of therapeutic efficacy. Objective: To describe three cases of patients with neurosyphilis (NS) treated at Hospital Universitário Gaffrée e Guinle, in Rio de Janeiro, Brazil, with suspected active syphilis with neurological symptoms. Case report: Three patients from Rio de Janeiro, Brazil, were investigated for symptomatic NS. The concentration of CSF-CXCL13 was prospectively performed by enzyme-linked immunosorbent assay (ELISA) in all participants at baseline and in follow-up visits at 3 months after therapy. CSF-CXCL13 concentrations were significantly higher in all three patients with established NS. The CSF-CXCL13 concentrations decreased after 3 months of therapy compared to baseline in all cases reported. The added high concentration of CSF-CXCL13 plus CSF-TPHA reactivity above 1:40 titer agreed with the diagnosis of NS in 100% of the cases. Conclusion: In this case series, we present three cases of NS diagnosed using CXCL13 in CSF as a complementary test. These case series suggest that the clinical use of CSF-CXCL13 is useful as a supplementary biomarker for NS and for monitoring the effectiveness of NS therapy, especially in patients with nonreactive CSF-VDRL, excluding other neurologic diseases

Síndrome de hipotensión endocraneana espontánea: reporte de un caso clínico / Spontaneous intracranial hypotension syndrome: clinic case report

La hipotensión intracraneal espontánea (SIH) es una patología con una incidencia anual aproximada de 5 por cada 100.000 personas al año, caracterizada clásicamente por cefalea ortostática comúnmente secundaria a una fuga espontánea de líquido cefalorraquídeo (LCR), pudiendo existir a su vez una amplia gama de síntomas asociados. El diagnóstico se centra en la clínica y en hallazgos típicos en la resonancia nuclear magnética (RM), sin embargo, según diversos estudios, puede corresponder a una patología subdiagnosticada por la dificultad que ha existido en definir criterios diagnósticos universales y un manejo terapéutico estandarizado, el cual varía inicialmente entre manejo médico conservador y/o parches de sangre epidural (PHE). Reportamos el caso de una paciente femenina de 51 años quien fue atendida en el Hospital Herminda Martin de Chillán donde se realizó el diagnóstico y tratamiento sintomático con PHE.

Spontaneous intracranial hypotension (SIH) is a pathology with an annual incidence of approximately 5 per 100,000 people per year, classically characterized by orthostatic headache commonly secondary to a spontaneous cerebrospinal fluid (CSF) leak, and there may also be a wide range of of associated symptoms. The diagnosis is centered on the clinic and on typical findings in magnetic resonance imaging (MRI), however, according to various studies, it may correspond to an underdiagnosed pathology due to the difficulty that has existed in defining universal diagnostic criteria and standardized therapeutic management. which initially varies between conservative medical management and/or epidural blood patches (PHE). We report the case of a 51-year-old female patient who was treated at the Herminda Martin de Chillán Hospital where the diagnosis and symptomatic treatment with PHE were made.

Comparative analysis between cytomorphology and flow cytometry methods in central nervous system infiltration assessment in oncohematological patients

ABSTRACT Introduction Oncohematological patients require the evaluation for possible infiltration of the central nervous system (CNS) by neoplastic cells at diagnosis and/or during the monitoring of the chemotherapeutic treatment. Morphological analysis using conventional microscopy is considered the method of choice to evaluate the cerebrospinal fluid (CSF) samples, despite technical limitations. Objective This study aimed to compare the performance of the cytomorphology and flow cytometric immunophenotyping (FC) in the detection of CNS infiltration. Method We evaluated 520 CSF samples collected from 287 oncohematological patients for whom the detection of neoplastic cells was simultaneously requested by cytomorphology and FC. Results Laboratory analyses revealed 435/520 (83.7%) conclusive results by the two methods evaluated, among which 385 (88.5%) were concordant. Discordance between the methods was observed in 50/435 (11.5%) samples, 45 (90%) being positive by FC. Furthermore, the FC defined the results in 69/72 (95.8%) inconclusive samples by cytomorphology. The positivity of FC was particularly higher among hypocellular samples. Among 431 samples with a cell count of < 5/μL, the FC identified neoplastic cells in 75 (17.4%), while the cytomorphology reported positive results in 26 (6%). Among the samples that presented adequate cell recovery for evaluation by both methods (506/520), the comparative analysis between FC and cytomorphology revealed a Kappa coefficient of 0.45 (CI: 0.37-0.52), interpreted as a moderate agreement. Conclusion The data showed that the CSF analysis by FC helps in the definition of CNS infiltration by neoplastic cells, particularly in the cases with dubious morphological analysis or in the evaluation of samples with low cellularity.

Genetic Architecture and Functional Implications of the CSF-Contacting Nucleus / 神经科学通报·英文版

We previously identified a unique nucleus, the cerebrospinal fluid (CSF)-contacting nucleus. This study aims to understand its gene architecture and preliminarily suggest its functions. The results showed that there were about 19,666 genes in this nucleus, of which 913 were distinct from the dorsal raphe nucleus (non-CSF contacting). The top 40 highly-expressed genes are mainly related to energy metabolism, protein synthesis, transport, secretion, and hydrolysis. The main neurotransmitter is 5-HT. The receptors of 5-HT and GABA are abundant. The channels for Cl-, Na+, K+, and Ca2+ are routinely expressed. The signaling molecules associated with the CaMK, JAK, and MAPK pathways were identified accurately. In particular, the channels of transient receptor potential associated with nociceptors and the solute carrier superfamily members associated with cell membrane transport were significantly expressed. The relationship between the main genes of the nucleus and life activities is preliminarily verified.

A glass micropipette vacuum technique of cerebrospinal fluid sampling in C57BL/6 mice / 生理学报

The purpose of this study was to establish a suitable method for extracting cerebrospinal fluid (CSF) from C57BL/6 mice. A patch clamp electrode puller was used to draw a glass micropipette, and a brain stereotaxic device was used to fix the mouse's head at an angle of 135° from the body. Under a stereoscopic microscope, the skin and muscle tissue on the back of the mouse's head were separated, and the dura mater at the cerebellomedullary cistern was exposed. The glass micropipette (with an angle of 20° to 30° from the dura mater) was used to puncture at a point 1 mm inboard of Y-shaped dorsal vertebral artery for CSF sampling. After the first extraction, the glass micropipette was connected with a 1 mL sterile syringe to form a negative pressure device for the second extraction. The results showed that the successful rate of CSF extraction was 83.33% (30/36). Average CSF extraction amount was (7.16 ± 0.43) μL per mouse. In addition, C57BL/6 mice were given intranasally ferric ammonium citrate (FAC) to establish a model of brain iron accumulation, and the CSF extraction technique established in the present study was used for sampling. The results showed that iron content in the CSF from the normal saline control group was not detected, while the iron content in the CSF from FAC-treated group was (76.24 ± 38.53) μmol/L, and the difference was significant. These results suggest that glass micropipette vacuum technique of CSF sampling established in the present study has the advantages of simplicity, high success rate, large extraction volume, and low bleeding rate, and is suitable for the research on C57BL/6 mouse neurological disease models.

A review of the clinical significance of lumbar puncture in the diagnostic approach of Aneurysmal Subarachnoid Hemorrhage (SAH): A case report of CT-Negative and Lumbar Puncture–Positive SAH

@#Headaches are a common presentation in the emergency department (ED). Even though not all are potentially serious, some such as subarachnoid hemorrhage (SAH) can be more dangerous than others. SAH is a medical emergency with an almost 50% mortality rate. It is crucial not to miss the diagnosis of SAH, as a missed or delayed diagnosis can be severely detrimental. It classically presents as thunderclap headache, a severe, sudden-onset headache. There are various approaches in diagnosing or excluding SAH, which is classically done by performing a computed tomography (CT) scan followed by a lumbar puncture (LP). But with the improved sensitivity of more modern diagnostic tools, more physicians are in support of changing this classical teaching. The aim of this case report is to review the advantages and disadvantages of LP in diagnosing SAH, along with other diagnostic tools commonly used.

Perfil etiológico de las meningitis adquiridas en la comunidad en pacientes adultos en el Complejo Asistencial Sótero del Río, Santiago 2011-2017 / Community acquired meningitis in Santiago, Chile, 2011-2017

INTRODUCCIÓN: En Chile existe poca información sobre los microorganismos causantes de meningitis adquirida en la comunidad (MAC), la que es relevante a la hora de escoger el esquema antimicrobiano empírico. OBJETIVO: Describir la microbiología de MAC en pacientes mayores de 15 años atendidos en un hospital público de Santiago (Chile). METODOLOGÍA: Revisión de cultivos de líquido cefalorraquídeo positivos durante 2011-2017. Se recolectó la información clínica de los pacientes incluidos. Se excluyeron cultivos considerados como contaminación y las meningitis post-quirúrgicas. RESULTADOS: Se identificaron 20 episodios de meningitis bacteriana aguda (MBA) y seis episodios de meningitis criptocócica (MC) entre 2.720 cultivos. Los microorganismos causantes de MBA fueron: Streptococcus pneumoniae (50%), Listeria monocytogenes (25%) y otros cinco agentes (25%). Todos los pacientes con infección por L. monocytogenes presentaban alguna comorbilidad significativa. Cuatro de cinco casos de MC presentaban infección por VIH. CONCLUSIÓN: Streptococcus pneumoniae fue el microorganismo más frecuente de las MAC en esta serie, seguido por L. monocytogenes. Las recomendaciones actuales de esquemas empíricos de MAC consideran adecuadamente la cobertura de S. pneumoniae en todos los pacientes y de L. monocytogenes solo ante factores de riesgo. Además, es relevante considerar MC en casos en pacientes inmunocomprometidos.

BACKGROUND: In Chile, there is scarce information on the frequency of the causative microorganisms of community-acquired meningitis (CAM), which is relevant for the choice of empiric treatment. AIM: To describe the microbiology of CAM in patients over 15 years treated at a public hospital in Santiago (Chile). METHODS: Retrospective review of positive cerebrospinal fluid cultures during 2011-2017. Clinical information of the included patients was collected. Cultures considered as contamination and cases of post-surgical meningitis were excluded. RESULTS: We identified 20 episodes of bacterial meningitis (BM) and six episodes of cryptococcal meningitis (CM) in 2720 cultures. The microorganisms identified in BM cases were Streptococcus pneumoniae (50%), Listeria monocytogenes (25%) and five other agents (25%). All patients with L. monocytogenes infection had at least one well-known risk factor for this infection. Four of the five cases of CM had HIV infection. CONCLUSION: Streptococcus pneumoniae was the most frequent causative microorganism of CAM in this series, followed by L. monocytogenes. Current recommendations for empiric CAM regimens adequately consider coverage for S. pneumoniae in all patients and for L. monocytogenes only in those with risk factors. Furthermore, it is relevant to consider CM in cases involving immunocompromised patients.

Utilidad del recuento de unidades formadoras de colonia de Cryptococcus sp. en líquido cefalorraquídeo de pacientes con criptococosis meníngea asociada al sida / Cryptococcus' colony forming unit count usefulness

Antecedentes: El recuento de unidades formadoras de colonia (UFC) de Cryptococcus en el líquido cefalorraquídeo (LCR) sería un marcador fiable para el pronóstico del paciente y una herramienta simple y económica. Objetivo: Evaluar la utilidad del recuento de UFC de Cryptococcus spp. y compararlo con las variaciones de antígeno capsular de Cryptococcus (AgCr) en LCR.Materiales y métodos: Se realizó la revisión de historias clínicas de pacientes con meningoencefalitis por Cryptococcus asociada con el sida en nuestro centro, entre febrero de 2016 y julio de 2020. Se evaluaron los valores de UFC y AgCr en LCR durante la evolución de la micosis. Resultados y discusión: Se analizaron datos de 94 episodios clínicos de 85 pacientes, con un total de 297 observaciones de muestras de LCR. Se evidenció el valor del recuento de UFC por ser un marcador de viabilidad y de carga fúngica. El recuento de UFC bajo no necesariamente coexistió con un nivel bajo de AgCr. Con respecto a la evolución en el tiempo, la mayoría de los pacientes fueron diagnosticados con una alta carga fúngica y su descenso ocurrió más rápido que el del AgCr, por lo que reflejaría la mejora del paciente, permitiendo tomar conductas al respecto.Palabras clave: Criptococosis, carga fúngica, ufc/mL.

Background. The Cryptococcus' colony-forming unit (CFU) count in cerebrospinal fluid (CSF) would be a reliable marker for patient prognosis and a simple and inexpensive tool. Objectives: To evaluate the usefulness of the CFU count of Cryptococcus spp. And to compare it with the variations of Cryptococcus' capsular antigen (CrAg) in CSF.Materials and methods. Clinical records of patients with aids-related meningoencephalitis caused by Cryptococcusassisted in our center between February 2016 and July 2020 were reviewed. CFU count and CrAg values in CSF were evaluated during the evolution of the mycosis.Results and Discussion. Data from 94 clinical episodes of 85 patients with a total of 297 observations of CSF samples were analyzed.The importance of using the CFU count was evidenced as it is a viability and fungal load marker.Low CFU count did not necessarily coexist with low CrAg.Regarding the evolution over time, most of the patients were diagnosed with a high fungal load and its decrease occurred faster than that the one of AgCr. This would reflect the improvement of the patient, allowing behaviors to be taken in this regard

An anatomical training model for cerebrospinal liquid collection and myelography in embalmed dog cadavers / Modelo anatômico para treinamento de colheita de líquido cerebroespinhal e mielografia em cadáveres de cães quimicamente preparados

In research and academic activities, guidelines are essential and imperative especially on the use of animals. Alternative methods that do not bring academic or scientific harm should also be sought. This study aimed to develop a training model for the collection of cerebrospinal fluid (CSF) and myelography in the cervical and lumbar regions in cadavers of embalmed dogs, using an alcoholic solution and curing salts for fixation and conservation. The dogs were divided into 4 grups of 8 animal each and stored between 2ºC and 6ºC, for 30, 60, 90, or 120 days. Durotomy was performed to implant two urethral catheters (one in the cranial direction and another in the caudal direction to the spinal cord access site), in the subduraracnoid space. This space was fixed via manual infusion of saline solution with a 20-mL syringe to simulate the presence of the CSF and the positive pressure, while the puncture was made. Four cadavers of each group were randomly selected for the CSF puncture from the atlantooccipital joint and in the lumbar region between L5 and L6, respectively, and four were used for CSF puncture training, in which radiographic contrast (myelography) was injected in the same locations. This model was cost-effective, did not utilize toxic products, and can preserve cadavers for up to 120 days. In this novel anatomical model, a maximum of 15 students can be trained on CSF puncture, allowing cervical and lumbar myelography and at least 30 perforations per cadaver.

É essencial e imperioso ter critério quanto ao uso de animais em pesquisa e atividades de ensino e, consequentemente, buscar métodos alternativos que não causem prejuízo acadêmico ou científico. Para que não ocorra deterioração dos tecidos, a fixação e conservação de peças anatômicas e cadáveres devem ser realizadas. Objetivou-se, com este estudo, desenvolver um modelo anatômico para treinamento de colheita de líquido cerebroespinhal (LCE) e mielografia, nas regiões cervical e lombar. Os cães foram divididos em quatro grupos contendo oito animais cada e armazenados entre 2ºC e 6ºC, por 30, 60, 90 ou 120 dias. Foi realizada durotomia para implantação de duas sondas uretrais, no espaço subaracnóide. A infusão manual de solução fisiológica com seringa de 20 mL foi utilizada para simular a presença do LCE e a pressão positiva, enquanto era feita a punção. Quatro cadáveres de cada grupo foram selecionados para a punção de LCE na articulação atlantooccipital e na região lombar entre L5 e L6, e quatro foram utilizados para o treinamento da punção de LCE e injeção de contraste radiográfico (mielografia). A técnica anatômica empregada possibilitou o desenvolvimento de um modelo visando ao ensino e pesquisa da radiologia em cadáveres de cães quimicamente preparados, a custo baixo e sem utilização de produtos tóxicos, mantidos sob refrigeração por 120 dias. Com isso, um máximo de 15 alunos podem ser treinados em punção do LCR, permitindo mielografia cervical e lombar com 30 perfurações por cadáver.

Meningite bacteriana: uma revisão / Bacterial meningitis: a review

A meningite bacteriana é uma inflamação das leptomeninges que envolvem o Sistema Nervoso Central. Essa patologia, que possui diversos agentes etiológicos, apresenta-se na forma de síndrome, com quadro clínico grave. Entre as principais bactérias que causam a meningite, estão a Neisseria meningitis e Streptococcus pneumoniae. A transmissão ocorre através das vias aéreas por meio de gotículas, sendo a corrente sanguínea a principal rota para as bactérias chegarem à barreira hematoencefálica e, a partir dessa, até as meninges. Atualmente existem vários métodos de diagnóstico precisos, onde a cultura de líquido cefalorraquidiano (LCR) é o método padrão ouro. Ademais, a melhora na qualidade do tratamento com beta-lactâmicos e a maior possibilidade de prevenção, devido à elevação do número e da eficácia de vacinas, vem contribuindo para redução dos casos da doença e de sua gravidade. Porém, apesar desses avanços, ainda há um elevado número de mortalidades e sequelas causadas por essa síndrome.

Bacterial meningitis is an inflammation of the leptomeninges that surround the Central Nervous System. This pathology, which has several etiological agents, is presented as a syndrome with a severe clinical scenario. The main bacteria causing meningitis include Neisseria meningitis and Streptococcus pneumoniae. It can be transmitted by droplets through the airways, with the bacteria using the bloodstream as the main route to reach the blood-brain barrier, and from there to the meninges. There are currently several accurate diagnostic methods, with CSF culture being the gold standard. In addition, the improvement in the quality of beta-lactam treatment and the greater possibility of prevention due to the increased number and effectiveness of vaccines have contributed to reducing the number of cases and severity of the disease. Nevertheless, despite these advances, this syndrome still presents a high number of mortalities and sequelae.

Validación de un método analítico para cuantificación de ferritina en líquido cefalorraquídeo / Validation of an analytical method for the quantification of ferritin in cerebrospinal fluid

Resumen La ferritina es una proteína de gran tamaño que se encuentra fisiológicamente en el líquido cefalorraquídeo (LCR) en concentraciones de 2-10 ng/mL. Su elevación puede utilizarse como biomarcador en distintas condiciones patológicas. El procedimiento de validación tradicional para la medición en LCR no puede ser utilizado debido a la ausencia de controles y calibradores comerciales para esta matriz. El objetivo de este trabajo fue llevar a cabo una validación analítica de ferritina en LCR. Se realizaron ensayos de estimación de precisión y veracidad mediante el protocolo EP15-A3, linealidad por el protocolo EP6-A (ambos de la guía de la CLSI), recuperación, estabilidad, contaminación por arrastre, interferencia por hemólisis y bilirrubina y límite de detección (LoD). La ferritina en LCR en el autoanalizador DxI 800 de Beckman Coulter tuvo una performance intra e interensayo <3,7%, el ensayo denota linealidad en el intervalo de 2,1-547 ng/mL; se estableció estabilidad por un período de 5 días y la recuperación resultó ser aceptable. No se evidenció efecto de contaminación por arrastre ni interferencia por hemólisis hasta un rango entre 300-500 mg/dL de hemoglobina, ni interferencia por bilirrubina hasta una concentración de 16,0 mg/dL de bilirrubina total. El LoD fue de 0,4 ng/mL. Por medio de los ensayos realizados se logró validar la ferritina en LCR a partir de la utilización de pools de muestras, lo que pudo garantizar la confiabilidad y exactitud del método analítico.

Abstract Ferritin is a large protein physiologically present in the cerebrospinal fluid (CSF) in concentrations of 2-10 ng/mL. Its elevation can be used as a biomarker in several pathological conditions. The traditional validation procedure for measurement in CSF cannot be used due to the absence of commercial controls and calibrators for this matrix. The objective of the present study was to perform CSF ferritin analytical validation. Assays such as precision and accuracy estimation through the EP15-A3 protocol, linearity according to the EP6-A protocol (both from the CLSI guidelines), recovery, stability, carry-over, hemolysis and bilirubin interference and limit of detection (LoD) were conducted. Serum samples with different concentrations of ferritin were added to aliquots of a normal CSF pool. CSF ferritin in the Beckman Coulter DxI 800 had a <3.7% intra and inter-assay performance, the assay shows linearity in the 2.1 -547 ng/mL interval, stability was established for a 5-day period and the recovery was acceptable. There was neither carry-over effect or hemolysis interference up to a range of 300-500 mg/dL of hemoglobin, nor interference by bilirubin up to 16.0 mg/dL of total bilirubin. The LoD was 0.4 ng/mL. By means of the performed assays, CSF ferritin was validated by using sample pools, thereby ensuring the reliability and accuracy of the analytical method.

Resumo A ferritina é uma grande proteína fisiologicamente encontrada no líquido cefalorraquidiano (LCR) em concentrações de 2 a 10 ng/mL. Sua elevação pode ser usada como biomarcador em diferentes condições patológicas. O procedimento de validação tradicional para medição no LCR não pode ser usado devido à ausência de controles e calibradores comerciais para esta matriz. O objetivo deste estudo foi realizar uma validação analítica da ferritina no LCR. Foram realizados estudos de precisão e veracidade utilizando o protocolo EP15-A3, linearidade pelo protocolo EP6-A (ambos das diretrizes do CLSI), recuperação, estabilidade, contaminação transportada, interferência de hemólise e bilirrubina e limite de detecção (LoD). A ferritina no LCR no DxI 800 da Beckman Coulter teve um desempenho intra e inter-ensaio <3,7%, o ensaio denota linearidade na faixa de 2,1-547 ng/mL, a estabilidade foi estabelecida em um período de 5 dias e a recuperação foi considerado aceitável. Nenhum efeito de transporte ou interferência por hemólise foi evidenciado até um intervalo entre 300-500 mg/dL de hemoglobina, nem interferência pela bilirrubina até uma concentração de 16,0 mg/dL de bilirrubina total. O LoD foi de 0,4 ng/mL. Através dos testes realizados, a ferritina no LCR foi validada, com base no uso de pool de amostras, o que poderia garantir a confiabilidade e a acurácia do método analítico.

Aplicación de un método in house para el estudio de la esclerosis múltiple / Application of an in-house method for the study of multiple sclerosis

Resumen El método de referencia para el estudio bioquímico de la esclerosis múltiple (EM) es el isoelectroenfoque (IEE) y la evaluación de las cadenas livianas libres (CLL) podría brindar una información adicional de relevancia. Por lo tanto, se propone evaluar la presencia de las CLL y la aplicabilidad de los estados de polimerización en el estudio de la EM. Se puso a punto un método compuesto por una separación electroforética en gel de poliacrilamida al 12,5% con posterior electrotransferencia (PAGE-WB) y se realizó la evaluación de 121 pacientes con sospecha de EM en simultáneo al IEE. Los patrones de PAGE-WB relacionados con la EM fueron el aumento de la concentración de monómeros Kappa o dímeros Lambda en líquido cefalorraquídeo (LCR) en comparación con el suero. Este método tuvo una muy alta significación de asociación con el IEE (p<0,0001) con sensibilidad del 95%, especificidad del 90%, VPP 83% y VPN 97%. La síntesis intratecal de CLL quedó evidenciada por el aumento de intensidad del monómero Kappa y/o el dímero Lambda observado en LCR. La técnica de PAGE-WB para CLL demostró ser un método alternativo para detectar la síntesis intratecal en pacientes con sospecha de EM.

Abstract The reference method for the biochemical study of multiple sclerosis (MS) is isoelectric focusing (IEF) and the evaluation of free light chains (FLC) could provide additional information of relevance. Therefore, it is proposed here to evaluate the presence of FLC and the applicability of the polymerisation states in the study of MS. A method consisting of a 12.5% polyacrylamide gel electrophoretic separation with a subsequent electrotransfer (PAGE-WB) was developed and the evaluation of 121 patients with suspected MS was carried out simultaneously with the IEF. MS-related PAGE-WB patterns were the increase in the concentration of Kappa monomers or Lambda dimers in CSF compared to serum. This method had a very high significance of association with the IEF (p<0.0001) with 95% sensitivity, 90% specificity, 83% PPV and 97% NPV. Intrathecal synthesis of FLC was evidenced by the increased intensity of the Kappa monomers and/or Lambda dimers observed in CSF. The PAGE-WB technique for FLC proved to be an alternative method to detect intrathecal synthesis in patients with suspected MS.

Resumo O método de referência para o estudo bioquímico da esclerose múltipla (EM) é a focalização isoelétrica (IEE) e a avaliação de cadeias leves livres (CLL) poderiam fornecer informações adicionais de relevância. Assim, propõe-se avaliar a presença das CLL e a aplicabilidade dos estados de polimerização no estudo de EM. Foi desenvolvido um método que consiste na separação eletroforética em gel de poliacrilamida a 12,5% com posterior eletrotranferência (PAGE-WB) e a avaliação de 121 pacientes com suspeita de EM foi realizada paralelamente à IEE. Os padrões de PAGE-WB relacionados com a EM foram o aumento na concentração de monômeros Kappa ou dímeros Lambda em líquido cefalorraquidiano (LCR) em comparação com o soro. Este método teve uma associação de significância muito alta com o IEE (p<0,0001) com sensibilidade de 95%, especificidade de 90%, VPP 83% e VPN 97%. A síntese intratecal de CLL foi evidenciada pelo aumento de intensidade do monômero Kappa e/ou dímero Lambda observado em LCR. A técnica PAGE-WB para CLL mostrou-se um método alternativo para detectar a síntese intratecal em pacientes com suspeita de EM.

An uncommon case of brucellosis with ocular presentation / Um caso incomum de brucelose com apresentação ocular

ABSTRACT We report an unusual case of brucellosis presented with headache, diminished vision, papillitis and multiple peripapillary hemorrhages accompanied by subretinal fluid extending up to macula. Diagnosis of brucellosis was made based on positive polymerase chain reaction of cerebrospinal fluid sample for Brucella species DNA, accompanied by a raised titer of anti-brucella antibodies. Patient showed remarkable improvement on triple drug therapy in form of doxycycline, rifampicin and ceftriaxone.

RESUMO Relatamos um caso incomum de brucelose apresentada com cefaleia, visão diminuída, papilite e múltiplas hemorragias peripapilares acompanhadas por fluido sub-retinal, estendendo-se até a mácula. O diagnóstico de brucelose foi feito com base na reação em cadeia da polimerase positiva de amostra de líquido cefalorraquidiano para DNA de espécies de Brucella, acompanhada por um título elevado de anticorpos antibrucela. O paciente apresentou melhora notável com a terapia tripla com drogas na forma de doxiciclina, rifampicina e ceftriaxona.

Meningitis tuberculosa: un desafío diagnóstico en pediatría / Tuberculous meningitis: diagnostic challenge in pediatrics

Resumen La meningitis por Mycobacterium tuberculosis es infrecuente en pediatría y su diagnóstico definitivo representa un desafío clínico. Presentamos el caso de un lactante de dos años, que presentó un cuadro de meningitis crónica. Se logró el diagnóstico tras la sospecha imagenológica y la confirmación tras la búsqueda seriada del complejo M. tuberculosis por RPC en LCR y en biopsia de tejido cerebral. A pesar de sus complicaciones, el paciente respondió favorablemente al tratamiento antituberculoso. En Chile, la tuberculosis es infrecuente en niños y los síntomas son generalmente inespecíficos. Los hallazgos en RM cerebral asociados a alteraciones del LCR permiten sospechar el compromiso meníngeo precozmente. Se recomienda iniciar el tratamiento antituberculoso empírico ante la sospecha, ya que mejora el pronóstico. A pesar de los avances diagnósticos y terapéuticos, la meningitis tuberculosa sigue teniendo una alta tasa de complicaciones y un pronóstico ominoso.

Abstract Mycobacterium tuberculosis meningitis is rare in the pediatric population and its definitive diagnosis represents a clinical challenge. We present the case of a 2-year-old infant with chronic meningitis. Diagnosis was accomplished by suggestive radiological findings and serial search for M. tuberculosis complex by real-time polymerase chain reaction (qPCR) in cerebrospinal fluid (CSF) and in brain tissue. Despite the complications, the patient evolved favorably with the tuberculosis treatment. In Chile, tuberculosis is a rare disease in children and symptoms are generally nonspecific. Brain MRI findings associated with CSF alterations allow early suspicion of MTBC. Start of empirical antituberculosis treatment upon suspicion is recommended given it is associated with better prognosis. Despite diagnostic and therapeutic advances, MTBC continues to have a high complication rate and an ominous prognosis.

Identification of the myodural bridge in a venomous snake, the gloydius shedaoensis: what is the functional significance? / Identificación del puente miodural en una serpiente venenosa, gloydius shedaoensis: ¿cuál es el significado funcional?

SUMMARY: Myodural bridges (MDB) are anatomical connections between the suboccipital muscles and the cervical dura mater which pass through both the atlanto-occipital and the atlanto-axial interspaces in mammals. In our previous studies, we found that the MDB exists in seven terrestrial mammal species, two marine mammal species, two reptilian species, and one bird species. A recent study suggested that given the "ubiquity" of myodural bridges in terrestrial vertebrates, the MDB may also exist in snakes. Specifically, we focused on the Gloydius shedaoensis, a species of Agkistrodon (pit viper snake) that is only found on Shedao Island, which is in the southeastern sea of Dalian City in China. Six head and neck cadaveric specimens of Gloydius shedaoensis were examined. Three specimens were used for anatomical dissection and the remaining three cadaveric specimens were utilized for histological analysis. The present study confirmed the existence of the MDB in the Gloydius shedaoensis. The snake's spinalis muscles originated from the posterior edge of the supraoccipital bones and the dorsal facet of the exocciput, and then extended on both sides of the spinous processes of the spine, merging with the semispinalis muscles. On the ventral aspect of this muscular complex, it gave off fibers of the MDB. These MDB fibers twisted around the posterior margin of the exocciput and then passed through the atlanto-occipital interspace, finally terminating on the dura mater. We observed that the MDB also existed in all of the snakes' intervertebral joints. These same histological findings were also observed in the Gloydius brevicaudus, which was used as a control specimen for the Gloydius shedaoensis. In snakes the spinal canal is longer than that observed in most other animals. Considering the unique locomotive style of snakes, our findings contribute to support the hypothesis that the MDB could modulate cerebrospinal fluid (CSF) pulsations.

RESUMEN: Los puentes miodurales (MDB) son conexiones anatómicas entre los músculos suboccipitales y la duramadre cervical que pasan a través de los espacios intermedios atlanto-occipital y atlanto-axial en los mamíferos. En nuestros estudios anteriores, encontramos que el MDB existe en siete especies de mamíferos terrestres, dos especies de mamíferos marinos, dos especies de reptiles y una especie de ave. Un estudio reciente sugirió que dada la "ubicuidad" de los puentes miodurales en los vertebrados terrestres, el MDB también puede existir en las serpientes. Específicamente, nos enfocamos en Gloydius shedaoensis, una especie de Agkistrodon (serpiente víbora) que solo se encuentra en la isla Shedao, en el mar sureste de la ciudad de Dalian en China. Se examinaron seis especímenes cadavéricos de cabeza y cuello de Gloydius shedaoensis. Se utilizaron tres especímenes para la disección anatómica y los tres especímenes cadavéricos restantes se utilizaron para el análisis histológico. El presente estudio confirmó la existencia del MDB en Gloydius shedaoensis. Los músculos espinosos de la serpiente se originaron en el margen posterior de los huesos supraoccipital y la cara dorsal del exoccipucio, y luego se extendieron a ambos lados de los procesos espinosas de la columna vertebral, fusionándose con los músculos semiespinosos. En la cara ventral de este complejo muscular se desprendían fibras del MDB. Estas fibras MDB se ubican alrededor del margen posterior del exoccipucio y luego atraviesan el interespacio atlanto-occipital, terminando finalmente en la duramadre. Observamos que el MDB también existía en todas las articulaciones intervertebrales de las serpientes. Estos mismos hallazgos histológicos también se observaron en Gloydius brevicaudus, que se utilizó como muestra de control para Gloydius shedaoensis. En las serpientes, el canal espinal es más largo que el observado en la mayoría de los otros animales. Teniendo en cuenta el estilo único locomotor de las serpientes, nuestros hallazgos contribuyen a respaldar la hipótesis de que el MDB podría modular las pulsaciones del líquido cerebroespinal.

Étiologies des méningites et méningoencéphalites dans les services de réanimation polyvalente à Libreville de 2020 à 2021 / Etiologies of meningitis and meningoencephalitis in intensive care units of Libreville from 2020 to 2021

Introduction. Les méningites/méningo-encéphalites sont des urgences médicales d'étiologies variées. La technique de diagnostic Multiplex Polymerase Chain Reaction (PCR) permet de détecter la présence de bactéries et de virus dans le liquide céphalorachidien (LCR) avec une spécificité et une sensibilité ≥ 90%. L'objectif de cette étude était d'identifier en utilisant cette technique, les principaux germes responsables des méningites et méningo-encéphalites en réanimation à Libreville. Patients et méthodes. Nous avons mené une étude transversale allant d'octobre 2020 à septembre 2021. Les critères d'inclusion étaient : être admis en réanimation au CHUL et à l'HIAOBO pour suspicion de méningite ou méningo-encéphalite, obtenir l'accord des familles pour l'analyse du liquide céphalorachidien (LCR) par multiplex PCR. Les variables étudiées étaient : la fréquence, les données sociodémographiques, les aspects cliniques et paracliniques. Résultats. Soixante et onze patients ont répondu aux critères d'inclusion. L'âge moyen était de 21,1 ± 10,4 ans et le sex ratio de 1,2. Les motifs d'admission étaient l'altération de l'état de conscience (77%) et l'état de mal épileptique (21%). Plasmodium falciparum a été retrouvé seul chez 38 patients (53,5%) et associé à Listeria monocytogenes chez 4 patients (1,4%). Les méningo-encéphalites à Herpès simplex virus ont été observées chez 4 patients (1,4%) dont l'âge variait entre 40 ans et moins de 50 ans. Un patient (1,4%) présentait une coinfection à S. épidermidis, flavivirus et alphavirus. Des méningo-encéphalites sans germes ont été observées chez 5 patients (%). Conclusion. Le principal germe responsable de méningoencéphalite en réanimation à Libreville est P. falciparum. Des virus tels que le flavivirus et l'alphavirus non détectés par les méthodes usuelles ont aussi été mis en évidence grâce au multiplex PCR.

Introduction. Meningitis/meningoencephalitis are medical emergencies of various etiologies. The Multiplex Polymerase Chain Reaction (PCR) technique allows the detection of the presence of bacteria and viruses in the cerebrospinal fluid (CSF) with a specificity and sensibility of above 90%. The aim of this study was to identify the most common germs responsible for meningitis and meningoencephalitis in the intensive care units of Libreville using this technique,. Patients and methods. We conducted a transversal study from October 2020 to September 2021. Inclusion criteria were: being admitted to intensive care unit of CHUL and HIAOBO for suspicion of meningitis or meningoencephalitis and having the parent's approval for multiplex PCR analysis of CSF. Variables studied included frequency, sociodemographic data, clinical and paraclinical aspects. Results. Seventy one patients were included. Mean age was 21.1 ± 10.4 years and the sex ratio was 1.2. Reasons for admission were altered consciousness (77%) and epilepsy (21%). Plasmodium (P) faciparum was detected alone in 38 cases (53.5%) and associated to Listeria monocytogenes in 4 patients (5.6%). Herpex simplex viral meningoencephalitis was observed in 4 patients (5.6%) aged between 40 and less than 50 years. One patient (1.4%) had co-infection with S. epidermidis, flavivirus and alphavirus. Meningoencephalitis with no germs was found in 5 patients (7%). Conclusion. The main etiology of meningoencephalitis in intensive care units of Libreville is P. falciparum. Viruses not detected by usual methods like flavivirus and alphavirus were detected by multiplex PCR.

Cerebrospinal Fluid β2-Microglobulin for Prognostic Evaluation of Patients with Central Nervous System Infiltration in Acute Lymphoblastic Leukemia / 中国实验血液学杂志

OBJECTIVE@#To investigate the prognostic value of serum and cerebrospinal fluid β2-microglobulin (β2-MG) in acute lymphoblastic leukemia (ALL) with central nervous system invasion after chemotherapy.@*METHODS@#40 patients with leukemia who had been confirmed to have central nervous system infiltration were selected for treatment at the Second Affiliated Hospital of Chongqing Medical University from January 2015 to May 2017, and the serum levels of β2-MG and CSF-β2MG were dynamically monitored and performed statistical analysis.@*RESULTS@#After chemotherapy, the changes in serum β2-MG were not statistically significant (P>0.05); the absolute level of CSF-β2MG and the percentage of relative baseline changes were statistically different in different clinical outcome groups(P<0.05), and the decreasing CSF-β2MG levels suggest a better prognosis, with cut-off values of 1.505 and -25%, respectively.@*CONCLUSION@#The best cut-off point may be a predictor of complete remission; the reduction of the absolute and relative levels of CSF-β2MG can suggest a good prognosis for patients.

Síndrome de Ramsay-Hunt: a propósito de dos casos en que se identificó el genoma del virus de la varicela-zóster en líquido cefalorraquídeo / Ramsay-Hunt syndrome: Report of two cases with identification of the varicella zoster virus genome in cerebrospinal fluid

Resumen | Como los otros herpesvirus alfa, el virus de la varicela-zóster (VZV) permanece en estado de latencia en los ganglios neurales después de la infección primaria (varicela). La reactivación de una infección latente por VZV en los ganglios de la raíz dorsal, produce el herpes zóster. La erupción que este provoca se caracteriza por lesiones cutáneas metaméricas que se acompañan de dolor neurítico y comprometen con mayor frecuencia a ancianos y sujetos inmunocomprometidos, en especial, aquellos infectados con el virus de la inmunodeficiencia humana (HIV). Las complicaciones que se observan en esta población de pacientes incluyen neumonía, hepatitis y compromiso del sistema nervioso central (meningitis y encefalitis). Varios síndromes clínicos se asocian con el herpes zóster de localización craneal, incluida la parálisis facial periférica y el síndrome de Ramsay-Hunt, el cual constituye la segunda causa de parálisis facial periférica y tiene una gran variedad de presentaciones clínicas. La parálisis facial se presenta en 60 a 90 % de los casos de síndrome de Ramsay-Hunt, puede preceder o aparecer después de las lesiones cutáneas y tiene peor pronóstico que la parálisis de Bell. Se describen aquí dos casos de herpes zóster del ganglio geniculado, con parálisis facial periférica que coincidió con la aparición de las lesiones cutáneas vesiculosas en el conducto auditivo externo y el pabellón auricular (síndrome de Ramsay-Hunt multimetamérico). En ambos casos, se identificó el genoma del VZV mediante PCR en el líquido cefalorraquídeo (LCR).

Abstract | Like other alpha-herpesviruses, the varicella-zoster virus (VZV) remains latent in the neural ganglia following the primary varicella infection. The reactivation of the VZV in the dorsal root ganglia results in herpes zoster. Herpes zoster eruption is characterized by localized cutaneous lesions and neuralgic pain mostly in older and immunocompromised persons, especially those living with the human immunodeficiency virus (HIV). The most commonly reported complications include VZV pneumonia, meningitis, encephalitis, and hepatitis. Several neurologic syndromes have been described associated with herpes zoster localized in cranial areas including peripheral nerve palsies and the Ramsay-Hunt syndrome, which has a varied clinical presentation and is the second most common cause of peripheral facial paralysis. Facial paralysis in this syndrome occurs in 60 to 90% of cases and it may precede or appear after the cutaneous lesions with a worse prognosis than idiopathic Bell paralysis. Here we present two cases of herpes zoster from the geniculate ganglia with peripheral facial paralysis that appeared simultaneously with vesicular herpetic otic lesions (multimetameric Ramsay-Hunt syndrome). In the two cases, amplifiable varicella-zoster viral DNA was found in the cerebrospinal fluid by RT-PCR Multiplex.