RESUMO
Peripheral nerve injuries (PNIs) represent a significant clinical challenge, particularly in elderly populations where axonal remyelination and regeneration are impaired. Developing therapies to enhance these processes is crucial for improving PNI repair outcomes. Glutamate carboxypeptidase II (GCPII) is a neuropeptidase that plays a pivotal role in modulating glutamate signaling through its enzymatic cleavage of the abundant neuropeptide N-acetyl aspartyl glutamate (NAAG) to liberate glutamate. Within the PNS, GCPII is expressed in Schwann cells and activated macrophages, and its expression is amplified with aging. In this study, we explored the therapeutic potential of inhibiting GCPII activity following PNI. We report significant GCPII protein and activity upregulation following PNI, which was normalized by the potent and selective GCPII inhibitor 2-(phosphonomethyl)-pentanedioic acid (2-PMPA). In vitro, 2-PMPA robustly enhanced myelination in dorsal root ganglion (DRG) explants. In vivo, using a sciatic nerve crush injury model in aged mice, 2-PMPA accelerated remyelination, as evidenced by increased myelin sheath thickness and higher numbers of remyelinated axons. These findings suggest that GCPII inhibition may be a promising therapeutic strategy to enhance remyelination and potentially improve functional recovery after PNI, which is especially relevant in elderly PNI patients where this process is compromised.
Assuntos
Glutamato Carboxipeptidase II , Traumatismos dos Nervos Periféricos , Remielinização , Animais , Camundongos , Traumatismos dos Nervos Periféricos/tratamento farmacológico , Traumatismos dos Nervos Periféricos/metabolismo , Remielinização/efeitos dos fármacos , Glutamato Carboxipeptidase II/antagonistas & inibidores , Glutamato Carboxipeptidase II/metabolismo , Bainha de Mielina/metabolismo , Bainha de Mielina/efeitos dos fármacos , Envelhecimento/efeitos dos fármacos , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/metabolismo , Camundongos Endogâmicos C57BL , Regeneração Nervosa/efeitos dos fármacos , Nervo Isquiático/lesões , Nervo Isquiático/efeitos dos fármacos , Masculino , Axônios/efeitos dos fármacos , Axônios/metabolismoRESUMO
INTRODUCTION: Robotic-assisted surgery (RAS) offers potential advantages over traditional surgical approaches. This study aimed to assess outcomes from a district general hospital (DGH) robotic colorectal programme against published data. MATERIALS AND METHODS: The robotic programme was established following simulator, dry/wet lab training, and proctoring. We performed a case series analysing technical, patient, and oncological outcomes extracted from a prospective database of colorectal RAS cases (2015-2022). A registered systematic review (PROSPERO CRD42022300773; PubMed, Web of Science, EMBASE) of single-centre colorectal series from established robotic centres (n>200 cases) was completed and compared to local data using descriptive summary statistics. Risk of bias assessment was performed using an adapted version of the Cochrane ROBINS-I tool. RESULTS: Two hundred thirty-two RAS cases were performed including 122 anterior resections, 56 APERs, 19 rectopexies, and 15 Hartmann's procedures. The median duration was 325 (IQR 265-400) min. Blood loss was < 100 ml in 97% of cases with 2 (0.9%) cases converted to open. Complications (Clavien-Dindo 3-5) occurred in 19 (8%) patients, with 3 (1.3%) deaths in < 30 days. Length of stay was 7 (IQR 5-11) days. In 169 rectal cancer cases, there were 9 (5.3%) cases with a positive circumferential or distal margin and lymph node yield of 17 (IQR 13-24). A systematic review of 1648 abstracts identified 13 studies from established robotic centres, totaling 4930 cases, with technical, patient, and oncological outcomes comparable to our own case series. CONCLUSIONS: Outcomes from our robotic colorectal programme at a UK DGH are comparable with the largest published case series from world-renowned centres. Training and proctoring together with rolling audit must accompany the expansion of robotic surgery to safeguard outcomes.
Assuntos
Laparoscopia , Neoplasias Retais , Procedimentos Cirúrgicos Robóticos , Humanos , Procedimentos Cirúrgicos Robóticos/métodos , Hospitais Gerais , Medicina Estatal , Resultado do Tratamento , Neoplasias Retais/cirurgiaRESUMO
Following peripheral nerve injury, multiple cell types, including axons, Schwann cells, and macrophages, coordinate to promote nerve regeneration. However, this capacity for repair is limited, particularly in older populations, and current treatments are insufficient. A critical component of the regeneration response is the network of cell-to-cell signaling in the injured nerve microenvironment. Sheddases are expressed in the peripheral nerve and play a role in the regulation if this cell-to-cell signaling through cleavage of transmembrane proteins, enabling the regulation of multiple pathways through cis- and trans-cellular regulatory mechanisms. Enhanced axonal regeneration has been observed in mice with deletion of the sheddase beta-secretase (BACE1), a transmembrane aspartyl protease that has been studied in the context of Alzheimer's disease. BACE1 knockout (KO) mice display enhanced macrophage recruitment and activity following nerve injury, although it is unclear whether this plays a role in driving the enhanced axonal regeneration. Further, it is unknown by what mechanism(s) BACE1 increases macrophage recruitment and activity. BACE1 has many substrates, several of which are known to have immunomodulatory activity. This review will discuss current knowledge of the role of BACE1 and other sheddases in peripheral nerve regeneration and outline known immunomodulatory BACE1 substrates and what potential roles they could play in peripheral nerve regeneration. Currently, the literature suggests that BACE1 and substrates that are expressed by neurons and Schwann cells are likely to be more important for this process than those expressed by macrophages. More broadly, BACE1 may play a role as an effector of immunomodulation beyond the peripheral nerve.
Assuntos
Secretases da Proteína Precursora do Amiloide/genética , Ácido Aspártico Endopeptidases/genética , Macrófagos/patologia , Regeneração Nervosa/genética , Traumatismos dos Nervos Periféricos/genética , Traumatismos dos Nervos Periféricos/patologia , Animais , Humanos , Nervos Periféricos/patologiaRESUMO
Heterophile antibody assays have been used to aid the diagnosis of infectious mononucleosis caused by the Epstein-Barr virus. Seven commercially available assays currently widely utilized in clinical laboratories were compared in this study. Variable performance characteristics and assay times are observed, and these pieces of data may assist clinical laboratories in assay selection and result interpretation.
Assuntos
Anticorpos Heterófilos/sangue , Anticorpos Antivirais/sangue , Técnicas de Laboratório Clínico/normas , Infecções por Vírus Epstein-Barr/diagnóstico , Mononucleose Infecciosa/diagnóstico , Mononucleose Infecciosa/imunologia , Kit de Reagentes para Diagnóstico/normas , Adolescente , Anticorpos Heterófilos/imunologia , Criança , Técnicas de Laboratório Clínico/métodos , Infecções por Vírus Epstein-Barr/sangue , Humanos , Imunoglobulina M/sangue , Mononucleose Infecciosa/sangue , Adulto JovemRESUMO
Cyber situational awareness has been proven to be of value in forming a comprehensive understanding of threats and vulnerabilities within organisations, as the degree of exposure is governed by the prevailing levels of cyber-hygiene and established processes. A more accurate assessment of the security provision informs on the most vulnerable environments that necessitate more diligent management. The rapid proliferation in the automation of cyber-attacks is reducing the gap between information and operational technologies and the need to review the current levels of robustness against new sophisticated cyber-attacks, trends, technologies and mitigation countermeasures has become pressing. A deeper characterisation is also the basis with which to predict future vulnerabilities in turn guiding the most appropriate deployment technologies. Thus, refreshing established practices and the scope of the training to support the decision making of users and operators. The foundation of the training provision is the use of Cyber-Ranges (CRs) and Test-Beds (TBs), platforms/tools that help inculcate a deeper understanding of the evolution of an attack and the methodology to deploy the most impactful countermeasures to arrest breaches. In this paper, an evaluation of documented CR and TB platforms is evaluated. CRs and TBs are segmented by type, technology, threat scenarios, applications and the scope of attainable training. To enrich the analysis of documented CR and TB research and cap the study, a taxonomy is developed to provide a broader comprehension of the future of CRs and TBs. The taxonomy elaborates on the CRs/TBs dimensions, as well as, highlighting a diminishing differentiation between application areas.
RESUMO
Oligodendroglia support axon survival and function through mechanisms independent of myelination, and their dysfunction leads to axon degeneration in several diseases. The cause of this degeneration has not been determined, but lack of energy metabolites such as glucose or lactate has been proposed. Lactate is transported exclusively by monocarboxylate transporters, and changes to these transporters alter lactate production and use. Here we show that the most abundant lactate transporter in the central nervous system, monocarboxylate transporter 1 (MCT1, also known as SLC16A1), is highly enriched within oligodendroglia and that disruption of this transporter produces axon damage and neuron loss in animal and cell culture models. In addition, this same transporter is reduced in patients with, and in mouse models of, amyotrophic lateral sclerosis, suggesting a role for oligodendroglial MCT1 in pathogenesis. The role of oligodendroglia in axon function and neuron survival has been elusive; this study defines a new fundamental mechanism by which oligodendroglia support neurons and axons.
Assuntos
Esclerose Lateral Amiotrófica/metabolismo , Esclerose Lateral Amiotrófica/patologia , Axônios/metabolismo , Transportadores de Ácidos Monocarboxílicos/metabolismo , Neurônios Motores/patologia , Degeneração Neural/metabolismo , Oligodendroglia/metabolismo , Simportadores/metabolismo , Esclerose Lateral Amiotrófica/genética , Animais , Axônios/patologia , Linhagem Celular , Sobrevivência Celular , Modelos Animais de Doenças , Regulação para Baixo , Heterozigoto , Humanos , Ácido Láctico/metabolismo , Camundongos , Camundongos Transgênicos , Transportadores de Ácidos Monocarboxílicos/deficiência , Transportadores de Ácidos Monocarboxílicos/genética , Neurônios Motores/metabolismo , Bainha de Mielina/metabolismo , Transporte Proteico , RNA Interferente Pequeno , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Superóxido Dismutase-1 , Simportadores/deficiência , Simportadores/genéticaRESUMO
Axons of the peripheral nervous system possess the capacity to regenerate following injury. Previously, we showed that genetically knocking out Beta-Site APP-Cleaving Enzyme 1 (BACE1) leads to increased nerve regeneration. Two cellular components, macrophages and neurons, contribute to enhanced nerve regeneration in BACE1 knockout mice. Here, we utilized a transgenic mouse model that overexpresses BACE1 in its neurons to investigate whether neuronal BACE1 has an inverse effect on regeneration following nerve injury. We performed a sciatic nerve crush in BACE1 transgenic mice and control wild-type littermates, and evaluated the extent of both morphological and physiological improvements over time. At the earliest time point of 3days, we observed a significant decrease in the length of axonal sprouts growing out from the crush site in BACE1 transgenic mice. At later times (10 and 15days post-crush), there were significant reductions in the number of myelinated axons in the sciatic nerve and the percentage of re-innervated neuromuscular junctions in the gastrocnemius muscle. Transgenic mice had a functional electrophysiological delay in the recovery up to 8weeks post-crush compared to controls. These results indicate that BACE1 activity levels have an inverse effect on peripheral nerve repair after injury. The results obtained in this study provide evidence that neuronal BACE1 activity levels impact peripheral nerve regeneration. This data has clinical relevance by highlighting a novel drug target to enhance peripheral nerve repair, an area which currently does not have any approved therapeutics.
Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Axônios/enzimologia , Regeneração Nervosa/fisiologia , Recuperação de Função Fisiológica/fisiologia , Nervo Isquiático/enzimologia , Nervo Isquiático/lesões , Secretases da Proteína Precursora do Amiloide/genética , Animais , Ácido Aspártico Endopeptidases/genética , Axônios/patologia , Modelos Animais de Doenças , Feminino , Humanos , Macrófagos/enzimologia , Macrófagos/patologia , Masculino , Camundongos Transgênicos , Músculo Esquelético/enzimologia , Músculo Esquelético/inervação , Músculo Esquelético/patologia , Fibras Nervosas Mielinizadas/enzimologia , Fibras Nervosas Mielinizadas/patologia , Junção Neuromuscular/enzimologia , Junção Neuromuscular/patologia , Distribuição Aleatória , Nervo Isquiático/patologiaRESUMO
AIM: Assessment of liver fibrosis in chronic hepatitis C (CHC) patients is necessary before antiviral treatment. This study aimed to evaluate the effectiveness of eight non-invasive models (aspartate aminotransferase [AST]/alanine transaminase ratio [AAR], AST/platelet ratio index [APRI], fibrosis-cirrhosis index [FCI], fibrosis index [FI], fibrosis-4 [FIB-4] score, fibrosis quotient [FibroQ], King, and von Willebrand factor antigen (vWF-Ag)/thrombocyte ratio [VITRO] scores) for predicting fibrosis compared with liver biopsy and to create a new score for predicting different fibrosis stages with increased accuracy. METHODS: We prospectively studied 127 treatment-naive CHC patients who underwent liver biopsy. The AAR, APRI, FCI, FI, FIB-4, FibroQ, King and VITRO scores were calculated and correlated with fibrosis stages. A new score (VAP) was derived from vWF-Ag, AST, and platelets: [VAP = (AST (U/L) × vWF-Ag)/platelets (109 /L)]. RESULTS: Apart from AAR, readily available scores were correlated with liver fibrosis stages. VITRO (r = 0.62) and APRI (r = 0.46) showed the closest correlation. Our new (VAP) score significantly correlated with fibrosis stages (r = 0.702, P < 0.001). Compared to other scores, VAP had the highest area under the receiver operating characteristic curve, with 0.854, 0.921, 0.849, and 0.861 for mild (F1), significant (≥F2), advanced (≥F3) fibrosis, and cirrhosis (F4) respectively. At a cut-off value >1, VAP had 75.2% sensitivity and 100% positive predictive value for predicting mild fibrosis. At a cut-off value >2.3 for predicting cirrhosis, VAP had 73% sensitivity and 81.7% positive predictive value. CONCLUSIONS: The VAP score is a novel model that had higher diagnostic performance to predict different fibrosis stages and subclinical cirrhosis among CHC patients compared to the other studied scores and hence may offer a useful strategy to stratify patients who would benefit from direct-acting antivirals.
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BACKGROUND: The Middle East respiratory syndrome (MERS) coronavirus causes isolated cases and outbreaks of severe respiratory disease. Essential features of the natural history of disease are poorly understood. METHODS: We studied 37 adult patients infected with MERS coronavirus for viral load in the lower and upper respiratory tracts (LRT and URT, respectively), blood, stool, and urine. Antibodies and serum neutralizing activities were determined over the course of disease. RESULTS: One hundred ninety-nine LRT samples collected during the 3 weeks following diagnosis yielded virus RNA in 93% of tests. Average (maximum) viral loads were 5 × 10(6) (6 × 10(10)) copies/mL. Viral loads (positive detection frequencies) in 84 URT samples were 1.9 × 10(4) copies/mL (47.6%). Thirty-three percent of all 108 serum samples tested yielded viral RNA. Only 14.6% of stool and 2.4% of urine samples yielded viral RNA. All seroconversions occurred during the first 2 weeks after diagnosis, which corresponds to the second and third week after symptom onset. Immunoglobulin M detection provided no advantage in sensitivity over immunoglobulin G (IgG) detection. All surviving patients, but only slightly more than half of all fatal cases, produced IgG and neutralizing antibodies. The levels of IgG and neutralizing antibodies were weakly and inversely correlated with LRT viral loads. Presence of antibodies did not lead to the elimination of virus from LRT. CONCLUSIONS: The timing and intensity of respiratory viral shedding in patients with MERS closely matches that of those with severe acute respiratory syndrome. Blood viral RNA does not seem to be infectious. Extrapulmonary loci of virus replication seem possible. Neutralizing antibodies do not suffice to clear the infection.
Assuntos
Formação de Anticorpos , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Eliminação de Partículas Virais , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Sangue/virologia , Fezes/virologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Coronavírus da Síndrome Respiratória do Oriente Médio/isolamento & purificação , Sistema Respiratório/virologia , Urina/virologia , Adulto JovemRESUMO
Hematogenous macrophages remove myelin debris from injured peripheral nerves to provide a micro-environment conducive to axonal regeneration. Previously, we observed that injured peripheral nerves from Beta-site APP Cleaving Enzyme 1 (BACE1) knockout (KO) mice displayed earlier influx of and enhanced phagocytosis by macrophages when compared to wild-type (WT) mice. These observations suggest that BACE1 might regulate macrophage influx into distal stumps of injured nerves. To determine through which pathway BACE1 influences macrophage influx, we used a mouse inflammation antibody array to assay the expression of inflammation-related proteins in injured nerves of BACE1 KO and WT mice. The most significant change was in expression of tumor necrosis factor receptor 1 (TNFR1) in the distal stump of injured BACE1 KO nerves. Western blotting of protein extracts confirmed increased expression of TNFR1 and its downstream transcriptional factor NFκB in the BACE1 KO distal stumps. Additionally, treatment of WT mice with a BACE1 inhibitor resulted in increased TNFR1 expression and signaling in the distal stump of injured nerves. Exogenous TNFα increased nuclear translocation of p65 NFκB in BACE1 KO tissue and cultured fibroblasts compared with control WT. BACE1 regulates TNFR1 expression at the level of gene expression and not through proteolytic processing. The accelerated macrophage influx in injured nerves of BACE1 KO mice correlates with increased expression and signaling via TNFR1, indicating a link between BACE1 activity and TNFR1 expression/signaling that might contribute to repair of the injured nervous system.
Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Bainha de Mielina/metabolismo , Traumatismos dos Nervos Periféricos/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Transdução de Sinais/fisiologia , Animais , Macrófagos/metabolismo , Camundongos Knockout , Regeneração Nervosa/fisiologia , Nervos Periféricos/metabolismo , Fagocitose/fisiologiaRESUMO
BACKGROUND: Peripheral neuropathy is a common and dose-limiting side effect of many cancer chemotherapies. The taxane agents, including paclitaxel (Taxol(®)), are effective chemotherapeutic drugs but cause degeneration of predominantly large myelinated afferent sensory fibers of the peripheral nervous system in humans and animal models. Dorsal root ganglia (DRG) neurons are sensory neurons that have unipolar axons each with two branches: peripheral and central. While taxane agents induce degeneration of peripheral axons, whether they also cause degeneration of central nervous system axons is not clear. Using a mouse model of paclitaxel-induced neuropathy, we investigated the effects of paclitaxel on the central branches of sensory axons. RESULTS: We observed that in the spinal cords of paclitaxel-intoxicated mice, degenerated axons were present in the dorsal columns, where the central branches of DRG axons ascend rostrally. In the peripheral nerves, degenerated myelinated fibers were present in significantly greater numbers in distal segments than in proximal segments indicating that this model exhibits the distal-to-proximal degeneration pattern generally observed in human peripheral nerve disorders. CONCLUSIONS: We conclude that paclitaxel causes degeneration of both the peripheral and central branches of DRG axons, a finding that has implications for the site and mode of action of chemotherapy agents on the nervous system.
Assuntos
Antineoplásicos/toxicidade , Axônios/efeitos dos fármacos , Gânglios Espinais/efeitos dos fármacos , Degeneração Neural/induzido quimicamente , Paclitaxel/toxicidade , Animais , Axônios/patologia , Modelos Animais de Doenças , Feminino , Gânglios Espinais/patologia , Masculino , Camundongos Endogâmicos C57BL , Microscopia Eletrônica , Degeneração Neural/patologia , Doenças do Sistema Nervoso Periférico/induzido quimicamente , Doenças do Sistema Nervoso Periférico/patologia , Nervo Isquiático/efeitos dos fármacos , Nervo Isquiático/patologia , Medula Espinal/efeitos dos fármacos , Medula Espinal/patologiaRESUMO
The newly emerged Middle East respiratory syndrome coronavirus (MERS-CoV) has infected at least 1,082 people, including 439 fatalities. So far, no empirical virus isolation study has been done to elucidate infectious virus secretion or serotype variability. Here, we used 51 respiratory samples from 32 patients with confirmed MERS-CoV infection for virus isolation in Vero B4 and Caco-2 cells. We found Caco-2 cells to significantly enhance isolation success over routinely used Vero cells. Isolation success correlated with viral RNA concentration and time after diagnosis as well as with the amount of IgA antibodies secreted in respiratory samples used for isolation. Results from plaque reduction neutralization assays using a representative range of serum samples and virus isolates suggested that all circulating human MERS-CoV strains represent one single serotype. The choice of prototype strain is not likely to influence the success of candidate MERS-CoV vaccines. However, vaccine formulations should be evaluated for their potential to induce IgA.
Assuntos
Infecções por Coronavirus/virologia , Coronavírus da Síndrome Respiratória do Oriente Médio/classificação , Sorogrupo , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Células CACO-2 , Chlorocebus aethiops , Infecções por Coronavirus/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Coronavírus da Síndrome Respiratória do Oriente Médio/isolamento & purificação , Arábia Saudita/epidemiologia , Células Vero , Cultura de Vírus , Adulto JovemRESUMO
Describe cultural beliefs related to diabetes in Minnesota Somali children with type 1 diabetes (T1D), and compare their diabetes control to that of non-Somali children with diabetes. A cross-sectional study involving Somali children ≤ 19 years with T1D at the University of Minnesota Masonic Children's Hospital and Children's Hospitals and Clinics of Minnesota. A survey was administered to parents of all participants and to children aged ≥ 12 years. Data were collected by history and from the medical record. Twenty-five Somali children participated, with 24 parent-child pairs (2 siblings). Mean participant age was 12.2 ± 5.2 (36% female). Seventy-one percent of parents indicated the child was "the same as before" other than having to do diabetes cares. Families were coping well, and the child was not treated differently than siblings. Performance of routine cares was described as the hardest part about having diabetes, but this was not related to traditional culture or religion. One notable exception was difficulty performing carbohydrate counting on Somali foods. Respondents were appreciative of the education provided by the diabetes team. Less than 10% used herbal supplements in addition to insulin. Mean HbA1c in Somali children was higher than the overall pediatric clinic average, 9.5 ± 1.6 % versus 8.8 ± 1.6 (p = 0.01). The difference was largely due to adolescent patients. The majority of Somali families cope well with diabetes and have a positive attitude towards the diabetes education. Glycemic control in adolescents is worse than in non-Somali peers. There is a need for culture-specific dietary instruction materials.
Assuntos
Cultura , Diabetes Mellitus Tipo 1/etnologia , Diabetes Mellitus Tipo 1/psicologia , Família/etnologia , Família/psicologia , Adaptação Psicológica , Adolescente , Criança , Cidades , Estudos Transversais , Diabetes Mellitus Tipo 1/terapia , Gerenciamento Clínico , Feminino , Hemoglobinas Glicadas , Humanos , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico , Masculino , Minnesota/epidemiologia , Somália/etnologiaRESUMO
Axonal damage is a common feature of traumatic injury and neurodegenerative disease. The capacity for axons to regenerate and to recover functionality after injury is a phenomenon that is seen readily in the peripheral nervous system, especially in rodent models, but human axonal regeneration is limited and does not lead to full functional recovery. Here we describe a system where dynamics of human axonal outgrowth and regeneration can be evaluated via live imaging of human-induced pluripotent stem cell (hiPSC)-derived neurons cultured in microfluidic systems, in which cell bodies are isolated from their axons. This system could aid in studying axonal outgrowth dynamics and could be useful for testing potential drugs that encourage regeneration and repair of the nervous system.
Assuntos
Axônios , Células-Tronco Pluripotentes Induzidas , Neurônios Motores , Regeneração Nervosa , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Axônios/fisiologia , Neurônios Motores/fisiologia , Neurônios Motores/citologia , Regeneração Nervosa/fisiologia , Microfluídica/métodos , Microfluídica/instrumentação , Diferenciação Celular , Células Cultivadas , Dispositivos Lab-On-A-Chip , Técnicas Analíticas Microfluídicas/instrumentação , Técnicas Analíticas Microfluídicas/métodos , Técnicas de Cultura de Células/métodosRESUMO
Anti-ganglioside antibodies (anti-Gg Abs) have been linked to delayed/poor clinical recovery in both axonal and demyelinating forms of Guillain-Barrè Syndrome (GBS). In many instances, the incomplete recovery is attributed to the peripheral nervous system's failure to regenerate. The cross-linking of cell surface gangliosides by anti-Gg Abs triggers inhibition of nerve repair in both in vitro and in vivo axon regeneration paradigms. This mechanism involves the activation of the small GTPase RhoA, which negatively modulates the growth cone cytoskeleton. At present, the identity/es of the receptor/s responsible for transducing the signal that ultimately leads to RhoA activation remains poorly understood. The aim of this work was to identify the transducer molecule responsible for the inhibitory effect of anti-Gg Abs on nerve repair. Putative candidate molecules were identified through proteomic mass spectrometry of ganglioside affinity-captured proteins from rat cerebellar granule neurons (Prendergast et al., 2014). These candidates were evaluated using an in vitro model of neurite outgrowth with primary cultured dorsal root ganglion neurons (DRGn) and an in vivo model of axon regeneration. Using an shRNA-strategy to silence putative candidates on DRGn, we identified tumor necrosis factor receptor 1A protein (TNFR1A) as a transducer molecule for the inhibitory effect on neurite outgrowth from rat/mouse DRGn cultures of a well characterized mAb targeting the related gangliosides GD1a and GT1b. Interestingly, lack of TNFr1A expression on DRGn abolished the inhibitory effect on neurite outgrowth caused by anti-GD1a but not anti-GT1b specific mAbs, suggesting specificity of GD1a/transducer signaling. Similar results were obtained using primary DRGn cultures from TNFR1a-null mice, which did not activate RhoA after exposure to anti-GD1a mAbs. Generation of single point mutants at the stalk region of TNFR1A identified a critical amino acid for transducing GD1a signaling, suggesting a direct interaction. Finally, passive immunization with an anti-GD1a/GT1b mAb in an in vivo model of axon regeneration exhibited reduced inhibitory activity in TNFR1a-null mice compared to wild type mice. In conclusion, these findings identify TNFR1A as a novel transducer receptor for the inhibitory effect exerted by anti-GD1a Abs on nerve repair, representing a significant step forward toward understanding the factors contributing to poor clinical recovery in GBS associated with anti-Gg Abs.
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Axônios , Gangliosídeos , Imunoglobulina G , Regeneração Nervosa , Receptores Tipo I de Fatores de Necrose Tumoral , Proteína rhoA de Ligação ao GTP , Animais , Camundongos , Ratos , Axônios/metabolismo , Axônios/imunologia , Células Cultivadas , Gangliosídeos/metabolismo , Gangliosídeos/imunologia , Síndrome de Guillain-Barré/imunologia , Síndrome de Guillain-Barré/metabolismo , Síndrome de Guillain-Barré/patologia , Imunoglobulina G/imunologia , Imunoglobulina G/metabolismo , Imunoglobulina G/farmacologia , Camundongos Knockout , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral/imunologia , Proteína rhoA de Ligação ao GTP/metabolismo , Proteína rhoA de Ligação ao GTP/imunologia , Transdução de SinaisRESUMO
OBJECTIVE: To evaluate the longitudinal correlations between sulfatide/lysosulfatide levels and central and peripheral nervous system function in children with metachromatic leukodystrophy (MLD) and to explore the impact of intravenous recombinant human arylsulfatase A (rhASA) treatment on myelin turnover. METHODS: A Phase 1/2 study of intravenous rhASA investigated cerebrospinal fluid (CSF) and sural nerve sulfatide levels, 88-item Gross Motor Function Measure (GMFM-88) total score, sensory and motor nerve conduction, brain N-acetylaspartate (NAA) levels, and sural nerve histology in 13 children with MLD. Myelinated and unmyelinated nerves from an untreated MLD mouse model were also analyzed. RESULTS: CSF sulfatide levels correlated with neither Z-scores for GMFM-88 nor brain NAA levels; however, CSF sulfatide levels correlated negatively with Z-scores of nerve conduction parameters, number of large (≥7 µm) myelinated fibers, and myelin/fiber diameter slope, and positively with nerve g-ratios and cortical latencies of somatosensory-evoked potentials. Quantity of endoneural litter positively correlated with sural nerve sulfatide/lysosulfatide levels. CSF sulfatide levels decreased with continuous high-dose treatment; this change correlated with improved nerve conduction. At 26 weeks after treatment, nerve g-ratio decreased by 2%, and inclusion bodies per Schwann cell unit increased by 55%. In mice, abnormal sulfatide storage was observed in non-myelinating Schwann cells in Remak bundles of sciatic nerves but not in unmyelinated urethral nerves. INTERPRETATION: Lower sulfatide levels in the CSF and peripheral nerves correlate with better peripheral nerve function in children with MLD; intravenous rhASA treatment may reduce CSF sulfatide levels and enhance sulfatide/lysosulfatide processing and remyelination in peripheral nerves.
Assuntos
Leucodistrofia Metacromática , Psicosina/análogos & derivados , Criança , Humanos , Camundongos , Animais , Leucodistrofia Metacromática/tratamento farmacológico , Sulfoglicoesfingolipídeos/farmacologia , Cerebrosídeo Sulfatase , Nervo Isquiático/patologiaRESUMO
Nephrogenic adenoma (NA) is a rare, benign lesion of the urinary tract that is induced by chronic irritation or injury to the urinary tract. Ureteral nephrogenic adenoma arising from both ureters is an exceptionally rare condition. We report an unusual case of a 73-year-old male who presented with a several-month history of recurrent UTI-like symptoms. Subsequent imaging showed bilateral hydronephrosis and ureteral wall thickening. A retrograde ureteroscopy revealed several papillary masses filling the lumens of both ureters. Ureteroscopic biopsies revealed NA in both ureters.
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Adenomatoid tumours are rare benign neoplasm involving the para testicular region, mostly the tail of the epididymis. They are typically small, firm and asymptomatic masses in the scrotal region and often discovered incidentally during physical examination or imaging studies. It is very challenging to differentiate them clinically and radiologically from malignant intratesticular solid tumours, which may lead to unnecessary orchidectomies. This case report presents the clinical management of a 57-year-old male patient with adenomatoid tumour of the epididymis, highlighting the diagnostic workup, surgical approach and postoperative outcomes. In addition, a comprehensive literature review was conducted to discuss the morphological and immunohistochemical features to improve understanding of these rare lesions and assist in accurate diagnosis and appropriate management.
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Klippel-Trenaunay-Weber (KTW) syndrome, a rare vascular disorder, often presents with cutaneous capillary malformations and soft tissue hypertrophy. However, urinary tract involvement in the form of vesical haemangiomas is a seldom-encountered clinical condition. We present a case of a 37-year-old male with KTW syndrome who exhibited recurrent gross haematuria, prompting clinical evaluation. Initial diagnostic assessments revealed erythematous changes in the bladder, consistent with haemangiomas. Despite an initial biopsy and diathermy, the patient's symptoms recurred, leading to a subsequent management strategy involving laser fulguration. This case underscores the significance of recognizing cutaneous haemangiomas as potential indicators of urinary tract involvement in KTW syndrome and highlights the challenges in managing vesical haemangiomas, where a multidisciplinary approach is essential for optimal care.
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Primary carcinoma in situ (CIS) solely affecting the ureter without concurrent involvement of the kidney or bladder is an exceptionally rare condition. This case report presents the clinical management of a 67-year-old male patient with primary ureteral CIS, highlighting the diagnostic workup, surgical approach, and postoperative outcomes. The diagnosis was established through the use of CT and ureteroscopy, leading to the decision for radical laparoscopic nephroureterectomy. Additionally, a comprehensive literature review was conducted to discuss the diagnostic challenges and management options for primary ureteral CIS.