RESUMEN
Synaptic plasticity plays a crucial role in memory formation by regulating the communication between neurons. Although actin polymerization has been linked to synaptic plasticity and dendritic spine stability, the causal link between actin polymerization and memory encoding has not been identified yet. It is not clear whether actin polymerization and structural changes in dendritic spines are a driver or a consequence of learning and memory. Using an extrinsically disordered form of the protein kinase LIMK1, which rapidly and precisely acts on ADF/cofilin, a direct modifier of actin, we induced long-term enlargement of dendritic spines and enhancement of synaptic transmission in the hippocampus on command. The activation of extrinsically disordered LIMK1 in vivo improved memory encoding and slowed cognitive decline in aged mice exhibiting reduced cofilin phosphorylation. The engineered memory by an extrinsically disordered LIMK1 supports a direct causal link between actin-mediated synaptic transmission and memory.
Asunto(s)
Actinas , Hipocampo , Ratones , Animales , Actinas/metabolismo , Hipocampo/metabolismo , Factores Despolimerizantes de la Actina/metabolismo , Fosforilación/fisiología , Plasticidad Neuronal/fisiologíaRESUMEN
Background: Our aim was to describe the clinical outcome and safety of the sequential treatment with off-label dalbavancin in patients with spondylodiscitis that is caused by methicillin-resistant Staphylococcus aureus (MRSA). Methods: We retrospectively included all patients >18 years of age with spondylodiscitis that is caused by MRSA that was treated with dalbavancin from January 2018−January 2021, recording the instances of clinical cure/failure, adverse events, and the need to be re-hospitalized after the initiation of dalbavancin. In 2/15 patients, we performed therapeutic drug monitoring (TDM) for dalbavancin. Results: We included 15 patients, 53.3% of them were females, with a median age of 67.9 years (57.4−78.5); 100% patients reported back pain, while a fever was present only in 2/15 cases. The spondylodiscitis was localized in 86.6% cases at the lumbar level. A median of a 2-week in-hospital intravenous vancomycin was followed by dalbavancin with a median duration of 12 weeks (12−16). All patients reported a clinical cure, except for a woman who is still on a suppressive treatment. No patient needed to be re-hospitalized, access to emergency department, or experienced adverse events. The TDM for dalbavancin showed that more than 90% of the determinations were above the pharmacodynamic target against staphylococci. Conclusions: The results from our unique, even if it was small, cohort demonstrated that dalbavancin can be a safe/effective option as a sequential treatment in patients with serious infections requiring prolonged antibiotic therapy, such as spondylodiscitis.
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Rapid eye movement (REM) sleep is associated with the consolidation of emotional memories. Yet, the underlying neocortical circuits and synaptic mechanisms remain unclear. We found that REM sleep is associated with a somatodendritic decoupling in pyramidal neurons of the prefrontal cortex. This decoupling reflects a shift of inhibitory balance between parvalbumin neuron-mediated somatic inhibition and vasoactive intestinal peptide-mediated dendritic disinhibition, mostly driven by neurons from the central medial thalamus. REM-specific optogenetic suppression of dendritic activity led to a loss of danger-versus-safety discrimination during associative learning and a lack of synaptic plasticity, whereas optogenetic release of somatic inhibition resulted in enhanced discrimination and synaptic potentiation. Somatodendritic decoupling during REM sleep promotes opposite synaptic plasticity mechanisms that optimize emotional responses to future behavioral stressors.
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Dendritas , Plasticidad Neuronal , Corteza Prefrontal , Sueño REM , Animales , Dendritas/fisiología , Ratones , Plasticidad Neuronal/fisiología , Parvalbúminas/metabolismo , Corteza Prefrontal/citología , Corteza Prefrontal/fisiología , Células Piramidales/fisiología , Sueño REM/fisiología , Tálamo/citología , Tálamo/fisiologíaRESUMEN
BACKGROUND AND AIM: Lung ultrasound (LUS) is a convenient imaging modality in the setting of coronavirus disease-19 (COVID-19) because it is easily available, can be performed bedside and repeated over time. We herein examined LUS patterns in relation to disease severity and disease stage among patients with COVID-19 pneumonia. METHODS: We performed a retrospective case series analysis of patients with confirmed SARS-CoV-2 infection who were admitted to the hospital because of pneumonia. We recorded history, clinical parameters and medications. LUS was performed and scored in a standardized fashion by experienced operators, with evaluation of up to 12 lung fields, reporting especially on B-lines and consolidations. RESULTS: We included 96 patients, 58.3% men, with a mean age of 65.9 years. Patients with a high-risk quick COVID-19 severity index (qCSI) were older and had worse outcomes, especially for the need for high-flow oxygen. B-lines and consolidations were located mainly in the lower posterior lung fields. LUS patterns for B-lines and consolidations were significantly worse in all lung fields among patients with high versus low qCSI. B-lines and consolidations were worse in the intermediate disease stage, from day 7 to 13 after onset of symptoms. While consolidations correlated more with inflammatory biomarkers, B-lines correlated more with end-organ damage, including extrapulmonary involvement. CONCLUSIONS: LUS patterns provide a comprehensive evaluation of patients with COVID-19 pneumonia that correlated with severity and dynamically reflect disease stage. LUS patterns may reflect different pathophysiological processes related to inflammation or tissue damage; consolidations may represent a more specific sign of localized disease, whereas B-lines seem to be also dependent upon generalized illness due to SARS-CoV-2 infection.
RESUMEN
Imaging neuronal activity with high and homogeneous spatial resolution across the field-of-view (FOV) and limited invasiveness in deep brain regions is fundamental for the progress of neuroscience, yet is a major technical challenge. We achieved this goal by correcting optical aberrations in gradient index lens-based ultrathin (≤500 µm) microendoscopes using aspheric microlenses generated through 3D-microprinting. Corrected microendoscopes had extended FOV (eFOV) with homogeneous spatial resolution for two-photon fluorescence imaging and required no modification of the optical set-up. Synthetic calcium imaging data showed that, compared to uncorrected endoscopes, eFOV-microendoscopes led to improved signal-to-noise ratio and more precise evaluation of correlated neuronal activity. We experimentally validated these predictions in awake head-fixed mice. Moreover, using eFOV-microendoscopes we demonstrated cell-specific encoding of behavioral state-dependent information in distributed functional subnetworks in a primary somatosensory thalamic nucleus. eFOV-microendoscopes are, therefore, small-cross-section ready-to-use tools for deep two-photon functional imaging with unprecedentedly high and homogeneous spatial resolution.
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Microscopía de Fluorescencia por Excitación Multifotónica/métodos , Tálamo/diagnóstico por imagen , Animales , Conducta Animal , Endoscopios , Femenino , Masculino , Ratones , Ratones Endogámicos C57BL , Microscopía de Fluorescencia por Excitación Multifotónica/instrumentación , Neuronas/fisiología , Tálamo/fisiologíaRESUMEN
Pemphigus vulgaris is an autoimmune bullous disease that involves the skin and mucous membranes. Current therapies aim to decrease antibody production by means of the use of systemic corticosteroids, immunosuppressive agents and, recently, rituximab, an anti-CD20 monoclonal antibody. However, the chronic immune suppression could entail complications, like infections and secondary malignancies. We describe a case of a patient with pemphigus who developed a sepsis due to Citrobacter freundii infection.
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Citrobacter freundii , Infecciones por Enterobacteriaceae/diagnóstico , Huésped Inmunocomprometido , Factores Inmunológicos/efectos adversos , Pénfigo/tratamiento farmacológico , Rituximab/efectos adversos , Anciano , Antibacterianos/uso terapéutico , Diagnóstico Diferencial , Infecciones por Enterobacteriaceae/sangre , Infecciones por Enterobacteriaceae/tratamiento farmacológico , Humanos , MasculinoAsunto(s)
Ciclofosfamida/administración & dosificación , Inmunomodulación , Tuberculosis/tratamiento farmacológico , Vasculitis del Sistema Nervioso Central/tratamiento farmacológico , Femenino , Humanos , Persona de Mediana Edad , Tomografía Computarizada por Rayos X , Tuberculosis/complicaciones , Vasculitis del Sistema Nervioso Central/diagnóstico por imagen , Vasculitis del Sistema Nervioso Central/microbiologíaAsunto(s)
Enfermedad de Whipple/complicaciones , Enfermedad de Whipple/diagnóstico , Anticuerpos/líquido cefalorraquídeo , Cardiolipinas/inmunología , Enfermedades Gastrointestinales/complicaciones , Humanos , Masculino , Persona de Mediana Edad , Enfermedades del Sistema Nervioso/etiología , Enfermedades del Sistema Nervioso/microbiología , Disco Óptico/diagnóstico por imagen , Enfermedad de Whipple/líquido cefalorraquídeo , Enfermedad de Whipple/virologíaRESUMEN
Details of two patients with alcohol-related and mixed aetiology cirrhosis who developed acute-on-chronic liver failure/hepatic decompensation with no obvious precipitants are reported. Cytomegalovirus (CMV) infection or reactivation was diagnosed in both, and required treatment with ganciclovir in one. Both returned to baseline hepatic function and remain well. Physicians should be alert to the possibility that CMV might cause or contribute to hepatic decompensation in patients with cirrhosis, even if they are not severely immunocompromised, and especially if they are alcohol misusers.
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BACKGROUND: HCV RNA viral load is an important predictor of sustained virological response and, recently, a significant correlation with liver fibrosis was described. We investigated on possible influence of clinical and viro-immunological variables on HCV viral load in HIV-HCV co-infected patients over a study time of three years (2009-2012). METHODS: We retrospectively enrolled 98 adult patients with a diagnosis of chronic HIV infection in 2009, a diagnosis of chronic HCV infection with a detectable plasma HCV RNA in 2009 and 2012, HCV therapy-naïve or with failed and stopped antiviral treatment before June 2008. The following variables were recorded: age, gender, HCV genotype, IL28B rs12979860 CC genotype, HCV treatment status, advanced liver fibrosis diagnosis, antiretroviral therapy, CD4+ cell count, HCV viral load, HIV RNA (plasma HIV-1 RNA levels were measured from blood samples every three months at least). The correlation was established using linear regression analysis, analysis of variance and Fisher's exact test. Comparisons between groups were performed using Fisher's exact test, the independent samples t-test and the t-test for paired data, as appropriate, for continuous variables. A mixed mode (ME) maximum likelihood linear regression model was constructed to evaluate the dependence of HCV viral load. RESULTS: HCV RNA levels did not change significantly from 2009 to 2012 (from 3924650 ± 5320177 IU/ml to 3085128 ± 3372347 IU/ml, p = 0.13); the CD4+ count increased significantly (from a mean of 576 to a mean of 654, p = 0.003). Using linear regression, a positive correlation was observed for HCV load and genotype 1 (p = 0.002), nonresponder status (p = 0.04) and with interleukin 28B CC allele (p = 0.05). Other studied covariates failed to reach a significant correlation. CONCLUSIONS: The HCV RNA load, a known pretreatment predictor of response to antiviral therapy, was independent of the two main parameters of HIV disease, plasma HIV RNA and CD4 cell count, over an observation time of 3 years in patients with recovered or spontaneously maintained immunocompetence.
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BACKGROUND: A study including 166 subjects was performed to investigate the frequency and persistence over a 6-month interval of concurrent oral and anal Human Papillomavirus (HPV) infections in Human Immunodeficiency Virus (HIV)-infected men who have sex with men (MSM). METHODS: Patients with no previously documented HPV-related anogenital lesion/disease were recruited to participate in a longitudinal study. Polymerase chain reaction (PCR) was performed to detect HPV from oral and anal swabs and to detect Human Herpes Virus 8 (HHV-8) DNA in saliva on 2 separate specimen series, one collected at baseline and the other collected 6 months later. A multivariate logistic analysis was performed using anal HPV infection as the dependent variable versus a set of covariates: age, HIV plasma viral load, CD4+ count, hepatitis B virus (HBV) serology, hepatitis C virus (HCV) serology, syphilis serology and HHV-8 viral shedding. A stepwise elimination of covariates with a p-value > 0.1 was performed. RESULTS: The overall prevalence of HPV did not vary significantly between the baseline and the follow-up, either in the oral (20.1 and 21.3%, respectively) or the anal specimens (88.6 and 86.3%). The prevalence of high-risk (HR) genotypes among the HPV-positive specimens was similar in the oral and anal infections (mean values 24.3% and 20.9%). Among 68 patients with either a HR, low-risk (LR) or undetermined genotype at baseline, 75% had persistent HPV and the persistence rates were 71.4% in HR infections and 76.7% in LR infections. There was a lack of genotype concordance between oral and anal HPV samples. The prevalence of HR HPV in anus appeared to be higher in the younger patients, peaking (> 25%) in the 43-50 years age group. A decrease of the high level of anal prevalence of all genotypes of HPV in the patients > 50 years was evident. HHV-8 oral shedding was positively related to HPV anal infection (p = 0.0046). A significant correlation was found between the persistence of HHV-8 shedding and HIV viral load by logistic bivariate analysis (Odds Ratio of HHV-8 persistence for 1-log increase of HIV viral load = 1.725 ± 0.397, p = 0.018). CONCLUSIONS: A high prevalence of HPV infection was found in our cohort of HIV-infected MSM, with a negative correlation between anal HPV infection and CD4 cell count.