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1.
Mol Ther ; 32(6): 1721-1738, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38566414

RESUMO

Recombinant adeno-associated viruses (AAVs) allow rapid and efficient gene delivery to the nervous system, are widely used in neuroscience research, and are the basis of FDA-approved neuron-targeting gene therapies. Here we find that an innate immune response to the AAV genome reduces dendritic length and complexity and disrupts synaptic transmission in mouse somatosensory cortex. Dendritic loss is apparent 3 weeks after injection of experimentally relevant viral titers, is not restricted to a particular capsid serotype, transgene, promoter, or production facility, and cannot be explained by responses to surgery or transgene expression. AAV-associated dendritic loss is accompanied by a decrease in the frequency and amplitude of miniature excitatory postsynaptic currents and an increase in the proportion of GluA2-lacking, calcium-permeable AMPA receptors. The AAV genome is rich in unmethylated CpG DNA, which is recognized by the innate immunoreceptor Toll-like receptor 9 (TLR9), and acutely blocking TLR9 preserves dendritic complexity and AMPA receptor subunit composition in AAV-injected mice. These results reveal unexpected impacts of an immune response to the AAV genome on neuronal structure and function and identify approaches to improve the safety and efficacy of AAV-mediated gene delivery in the nervous system.


Assuntos
Dendritos , Dependovirus , Vetores Genéticos , Imunidade Inata , Transmissão Sináptica , Receptor Toll-Like 9 , Animais , Dependovirus/genética , Camundongos , Dendritos/metabolismo , Receptor Toll-Like 9/metabolismo , Receptor Toll-Like 9/genética , Vetores Genéticos/genética , Vetores Genéticos/administração & dosagem , Receptores de AMPA/genética , Receptores de AMPA/metabolismo , Córtex Somatossensorial/metabolismo , Córtex Somatossensorial/imunologia , Genoma Viral
2.
Clin Endocrinol (Oxf) ; 95(1): 125-133, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33728673

RESUMO

DESIGN: A retrospective review of the adverse events (AEs) in 78 patients during the glucagon stimulation test (GST) for the assessment of growth hormone deficiency (GHD) before and after protocol amendments which aimed to reduce AEs in a group of patients with a high prevalence of pituitary hormone deficiencies. PATIENTS: Based on our observations of frequent AEs during the standard GST protocol in an initial 25 patients (cohort 1), a modified protocol was introduced to include the routine administration of 20 mg of hydrocortisone pre-GST in a subsequent 53 patients (cohort 2). Post hoc analysis of the effect of glucocorticoid dosing pre-GST on AEs was examined in those receiving <20 mg hydrocortisone (group A, n = 19) vs ≥20 mg hydrocortisone (group B, n = 59). MEASUREMENTS: AEs including hypotension, hypoglycaemia and nausea/vomiting. RESULTS: Of the 78 patients undergoing the GST, 79% had ≥2 hormone deficiencies. Rates of AEs were 41% vs 30% for hypotension, 60% vs 28% for hypoglycaemia (p < .05) and 20% vs 13% for nausea/vomiting in cohort 1 compared with cohort 2, respectively. Post hoc analysis revealed lower rates of AEs in those receiving ≥20 mg hydrocortisone (group B) compared to those receiving <20 mg due to a reduction in hypoglycaemic events (82% vs 26%, p < .001) and hypotension (50% vs 27%, p = .05). Similar numbers of patients in group A and group B met criteria for GHD. CONCLUSIONS: In patients with a high prevalence of pituitary deficiencies, a modified GST protocol of additional stress dose glucocorticoid attenuated the frequency of AEs without appearing to compromise the performance of the GST.


Assuntos
Nanismo Hipofisário , Hormônio do Crescimento Humano , Adulto , Glucagon , Hormônio do Crescimento , Humanos , Prevalência , Estudos Retrospectivos
3.
BMC Cancer ; 20(1): 1130, 2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33225916

RESUMO

BACKGROUND: The translational interest in the intratumoral heterogeneity of hepatocellular carcinoma (HCC) has been increasing. The dismal prognosis of this pathology is linked to the features of the HCC harbouring cancer stem cells (CSC), represented by EpCAM-expression. However, the extent of the impact of intratumoral distribution of CSC-features, both on the recurrence after curative resection and on clinical outcome, remains unknown. To address this, we investigated the spatial heterogeneity of CSC-features with the aim of identifying the unique HCC patient subgroups amenable to adjuvant treatment. METHODS: We designed a tissue microarray (TMA) from patients who had received liver resection between 2011 and 2017. Tumor specimens were sampled at multiple locations (n = 3-8). EpCAM-positivity was assessed for intensity and proportion by applying a score dividing three groups: (i) negative (E-/-); (ii) heterogeneous (E-/+); and (iii) homogeneous (E+/+). The groups were further analysed with regard to time-to-recurrence (TTR) and recurrence-free-survival (RFS). RESULTS: We included 314 tumor spots from 69 patients (76.8% male, median age 66, liver cirrhosis/fibrosis 75.8%). The risk factors were alcohol abuse (26.2%), NASH (13.1%), HBV (15.5%), HCV (17.9%) and others (27.4%), representative of a typical Western cohort. E+/+ patients experienced significantly shorter TTR and RFS compared to E+/- and E-/- patients (TTR 5 vs. 19 months, p = 0.022; RFS 5 vs. 14 vs. 21 months, p = 0.016). Only homogeneous EpCAM-positivity correlated with higher AFP levels (> 400 ng/ml, p = 0.031). CONCLUSIONS: Spatial heterogeneity of EpCAM-expression was markedly present in the cohort. Of note, only homogeneous EpCAM-expression correlated significantly with early recurrence, whereas heterogeneous EpCAM-expression was associated with clinical endpoints comparable to EpCAM-negativity. We identified a unique HCC subtype associated with a high risk of tumor recurrence.


Assuntos
Carcinoma Hepatocelular/genética , Molécula de Adesão da Célula Epitelial/metabolismo , Neoplasias Hepáticas/genética , Células-Tronco Neoplásicas/metabolismo , Carcinoma Hepatocelular/patologia , Feminino , Heterogeneidade Genética , Humanos , Neoplasias Hepáticas/patologia , Masculino , Prognóstico , Fatores de Risco
4.
Intern Med J ; 48(12): 1435-1446, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30302919

RESUMO

The metabolic abnormalities affecting bone in the setting of chronic kidney disease (CKD) are complex with overlapping and interacting aetiologies and have challenging diagnostic and management strategies. Disturbances in calcium, phosphate, fibroblast growth factor 23, parathyroid hormone concentrations and vitamin D deficiency are commonly encountered and contribute to the clinical syndromes of bone disorders in CKD, including hyperparathyroidism, osteomalacia, osteoporosis and adynamic bone disease. Mineral and bone abnormalities may also persist or arise de novo post-renal transplantation. The Kidney Disease Improving Global Outcomes organisation describes these mineral metabolism derangements and skeletal abnormalities as 'CKD Mineral and Bone Disorder'. Patients with this disorder have an increased risk of fracture, cardiovascular events and overall increased mortality. In light of the recently updated 2017 guidelines from the Kidney Disease Improving Global Outcomes, we present a clinical case-based discussion to highlight the complexities of investigating and managing the bone health of patients with CKD with a focus on these updates.


Assuntos
Distúrbio Mineral e Ósseo na Doença Renal Crônica , Fraturas Ósseas , Distúrbio Mineral e Ósseo na Doença Renal Crônica/complicações , Distúrbio Mineral e Ósseo na Doença Renal Crônica/metabolismo , Distúrbio Mineral e Ósseo na Doença Renal Crônica/fisiopatologia , Distúrbio Mineral e Ósseo na Doença Renal Crônica/cirurgia , Distúrbio Mineral e Ósseo na Doença Renal Crônica/terapia , Gerenciamento Clínico , Fraturas Ósseas/etiologia , Fraturas Ósseas/prevenção & controle , Humanos
6.
Eur Radiol ; 27(12): 5337-5343, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28634626

RESUMO

OBJECTIVES: To compare hepatic 2D shear wave elastography (2D SWE) in children between free-breathing and breath-hold conditions, in terms of measurement agreement and time expenditure. METHODS: A cohort of 57 children (12.7±4.3 years) who underwent standardized 2D SWE between May and October 2015 were retrospectively evaluated. Liver elastograms were obtained under free-breathing and breath-hold conditions and time expenditure was measured. Median stiffness, interquartile range (IQR), and IQR/median ratio were calculated based on 12, six, and three elastograms. Results were compared using Pearson correlation coefficient, intraclass correlation coefficient (ICC), Bland-Altman analysis, and Student's t. RESULTS: Median liver stiffness under free-breathing and breath-hold conditions correlated strongly (7.22±4.5kPa vs. 7.21±4.11kPa; r=0.97, P<0.001). Time to acquire 12 elastograms with free-breathing was lower than that with breath-holding (79.3±32.5sec vs. 143.7±51.8sec, P<0.001). Results for median liver stiffness based of 12, six, and three elastograms demonstrated very high agreement for free-breathing (ICC 0.993) and for breath-hold conditions (ICC 0.994). CONCLUSIONS: Hepatic 2D SWE performed with free-breathing yields results similar to the breath-hold condition. With a substantially lower time requirement, which can be further reduced by lowering the number of elastograms, the free-breathing technique may be suitable for infants and less cooperative children not capable of breath-holding. KEY POINTS: • Hepatic 2D SWE performed with free-breathing yields results similar to breath-hold condition. • Benefit of the free-breathing approach is the substantially lower time requirement. • Lowering the number of elastograms can further reduce time expenditure. • Free-breathing 2D SWE is suitable in children with suspected liver disease.


Assuntos
Técnicas de Imagem por Elasticidade/métodos , Hepatopatias/diagnóstico , Fígado/diagnóstico por imagem , Respiração , Ultrassonografia Doppler/métodos , Adolescente , Biópsia , Suspensão da Respiração , Criança , Feminino , Humanos , Hepatopatias/fisiopatologia , Masculino , Reprodutibilidade dos Testes , Estudos Retrospectivos
7.
Magn Reson Med ; 74(5): 1257-65, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25359183

RESUMO

PURPOSE: Accurate triggering of the cardiac cycle is mandatory for optimal image acquisition and thus diagnostic quality in cardiac magnetic resonance imaging. The purpose of this work was to evaluate Doppler ultrasound as an alternative trigger method in cardiac MRI. METHODS: Steady-state free precession (SSFP) 2D cine CMR was performed in 11 healthy subjects at 1.5T. Doppler ultrasound (DUS), electrocardiogram (ECG) and pulse oximetry (POX) were used for cardiac triggering. DUS peak detection was verified in comparison to ECG. Quantitative analysis of image quality of each gating method was determined by calculating endocardial border sharpness (EBS) and left ventricular (LV) function parameters and compared with ECG. RESULTS: Mean difference between DUS and ECG in detected RR intervals was 0.04 ± 63 ms (r = 0.96). Trigger jitter was not different between ECG and DUS (P = 0.15) but significant different between ECG and POX (P = 0.01). EBS was similar between each method (3.1 ± 0.2 / 2.6 ± 0.2 / 2.9 ± 0.2 pixel). Mean differences in stroke volume were not significantly different with -1 ± 7 mL (ECG/DUS, P = 0.9) and 2 ± 10 mL (ECG/POX, P = 0.8). CONCLUSION: Cine cardiac MRI using DUS was successfully demonstrated. DUS triggering is an alternative method for cardiac MRI and may be applied in a clinical setting.


Assuntos
Eletrocardiografia/métodos , Processamento de Imagem Assistida por Computador/métodos , Oximetria/métodos , Ultrassonografia Doppler/métodos , Adulto , Algoritmos , Técnicas de Imagem Cardíaca , Feminino , Humanos , Masculino , Projetos Piloto , Processamento de Sinais Assistido por Computador
8.
Mol Imaging ; 132014.
Artigo em Inglês | MEDLINE | ID: mdl-25342533

RESUMO

The aim of this study was to investigate the feasibility of noninvasive monitoring of plaque burden in apolipoprotein E-deficient (ApoE-/-) mice by Gadospin F (GDF)-enhanced magnetic resonance imaging (MRI). Gadolinium uptake in plaques was controlled using transmission electron microscopy (TEM) and x-ray fluorescence (XRF) microscopy. To monitor the progression of atherosclerosis, ApoE-/- (n  =  5) and wild-type (n  =  2) mice were fed a Western diet and imaged at 5, 10, 15, and 20 weeks. Contrast-enhanced MRI was performed at 7 T Clinscan (Bruker, Ettlingen, Germany) before and 2 hours after intravenous injection of GDF (100 µmol/kg) to determine the blood clearance. Plaque size and contrast to noise ratio (CNR) were calculated for each time point using region of interest measurements to evaluate plaque progression. Following MRI, aortas were excised and GDF uptake was cross-validated by TEM and XRF microscopy. The best signal enhancement in aortic plaque was achieved 2 hours after application of GDF. No signal differences between pre- and postcontrast MRI were detectable in wild-type mice. We observed a gradual and considerable increase in plaque CNR and size for the different disease stages. TEM and XRF microscopy confirmed the localization of GDF within the plaque. GDF-enhanced MRI allows noninvasive and reliable estimation of plaque burden and monitoring of atherosclerotic progression in vivo.


Assuntos
Apolipoproteínas E/deficiência , Aterosclerose/patologia , Meios de Contraste/administração & dosagem , Complexos de Coordenação/administração & dosagem , Gadolínio/administração & dosagem , Animais , Aterosclerose/diagnóstico por imagem , Aterosclerose/genética , Imageamento por Ressonância Magnética , Camundongos , Camundongos Endogâmicos C57BL , Microscopia Eletrônica de Transmissão , Microscopia de Fluorescência , Radiografia
9.
BMC Endocr Disord ; 14: 91, 2014 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-25425285

RESUMO

BACKGROUND: Glucocorticoid replacement is essential in patients with primary and secondary adrenal insufficiency, but many patients remain on higher than recommended dose regimens. There is no uniformly accepted method to monitor the dose in individual patients. We have compared cortisol concentrations in plasma, saliva and urine achieved following "physiological" and "stress" doses of hydrocortisone as potential methods for monitoring glucocorticoid replacement. METHODS: Cortisol profiles were measured in plasma, saliva and urine following "physiological" (20 mg oral) or "stress" (50 mg intravenous) doses of hydrocortisone in dexamethasone-suppressed healthy subjects (8 in each group), compared to endogenous cortisol levels (12 subjects). Total plasma cortisol was measured half-hourly, and salivary cortisol and urinary cortisol:creatinine ratio were measured hourly from time 0 (between 0830 and 0900) to 5 h. Endogenous plasma corticosteroid-binding globulin (CBG) levels were measured at time 0 and 5 h, and hourly from time 0 to 5 h following administration of oral or intravenous hydrocortisone. Plasma free cortisol was calculated using Coolens' equation. RESULTS: Plasma, salivary and urine cortisol at 2 h after oral hydrocortisone gave a good indication of peak cortisol concentrations, which were uniformly supraphysiological. Intravenous hydrocortisone administration achieved very high 30 minute cortisol concentrations. Total plasma cortisol correlated significantly with both saliva and urine cortisol after oral and intravenous hydrocortisone (P <0.0001, correlation coefficient between 0.61 and 0.94). There was no difference in CBG levels across the sampling period. CONCLUSIONS: An oral dose of hydrocortisone 20 mg is supraphysiological for routine maintenance, while stress doses above 50 mg 6-hourly would rarely be necessary in managing acute illness. Salivary cortisol and urinary cortisol:creatinine ratio may provide useful alternatives to plasma cortisol measurements to monitor replacement doses in hypoadrenal patients.


Assuntos
Glucocorticoides/administração & dosagem , Hidrocortisona/administração & dosagem , Hidrocortisona/metabolismo , Saliva/metabolismo , Estresse Fisiológico , Administração Oral , Insuficiência Adrenal/tratamento farmacológico , Adulto , Creatinina/urina , Dexametasona/administração & dosagem , Esquema de Medicação , Feminino , Glucocorticoides/metabolismo , Glucocorticoides/farmacocinética , Voluntários Saudáveis , Terapia de Reposição Hormonal/métodos , Humanos , Hidrocortisona/sangue , Hidrocortisona/farmacocinética , Hidrocortisona/urina , Injeções Intravenosas , Masculino , Fatores de Tempo , Transcortina/metabolismo
10.
Nucleic Acids Res ; 40(12): 5448-64, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22367846

RESUMO

Mismatch repair (MMR) corrects replication errors such as mismatched bases and loops in DNA. The evolutionarily conserved dimeric MMR protein MutS recognizes mismatches by stacking a phenylalanine of one subunit against one base of the mismatched pair. In all crystal structures of G:T mismatch-bound MutS, phenylalanine is stacked against thymine. To explore whether these structures reflect directional mismatch recognition by MutS, we monitored the orientation of Escherichia coli MutS binding to mismatches by FRET and anisotropy with steady state, pre-steady state and single-molecule multiparameter fluorescence measurements in a solution. The results confirm that specifically bound MutS bends DNA at the mismatch. We found additional MutS-mismatch complexes with distinct conformations that may have functional relevance in MMR. The analysis of individual binding events reveal significant bias in MutS orientation on asymmetric mismatches (G:T versus T:G, A:C versus C:A), but not on symmetric mismatches (G:G). When MutS is blocked from binding a mismatch in the preferred orientation by positioning asymmetric mismatches near the ends of linear DNA substrates, its ability to authorize subsequent steps of MMR, such as MutH endonuclease activation, is almost abolished. These findings shed light on prerequisites for MutS interactions with other MMR proteins for repairing the appropriate DNA strand.


Assuntos
Pareamento Incorreto de Bases , Reparo de Erro de Pareamento de DNA , DNA/química , Proteínas de Escherichia coli/metabolismo , Proteína MutS de Ligação de DNA com Erro de Pareamento/metabolismo , DNA/metabolismo , Proteínas de Escherichia coli/química , Polarização de Fluorescência , Transferência Ressonante de Energia de Fluorescência , Corantes Fluorescentes , Modelos Moleculares , Proteína MutS de Ligação de DNA com Erro de Pareamento/química , Nucleotídeos/química , Ligação Proteica , Espectrometria de Fluorescência
11.
Rofo ; 196(4): 354-362, 2024 Apr.
Artigo em Inglês, Alemão | MEDLINE | ID: mdl-37944934

RESUMO

BACKGROUND: Imaging biomarkers are quantitative parameters from imaging modalities, which are collected noninvasively, allow conclusions about physiological and pathophysiological processes, and may consist of single (monoparametric) or multiple parameters (bi- or multiparametric). METHOD: This review aims to present the state of the art for the quantification of multimodal and multiparametric imaging biomarkers. Here, the use of biomarkers using artificial intelligence will be addressed and the clinical application of imaging biomarkers in breast and prostate cancers will be explained. For the preparation of the review article, an extensive literature search was performed based on Pubmed, Web of Science and Google Scholar. The results were evaluated and discussed for consistency and generality. RESULTS AND CONCLUSION: Different imaging biomarkers (multiparametric) are quantified based on the use of complementary imaging modalities (multimodal) from radiology, nuclear medicine, or hybrid imaging. From these techniques, parameters are determined at the morphological (e. g., size), functional (e. g., vascularization or diffusion), metabolic (e. g., glucose metabolism), or molecular (e. g., expression of prostate specific membrane antigen, PSMA) level. The integration and weighting of imaging biomarkers are increasingly being performed with artificial intelligence, using machine learning algorithms. In this way, the clinical application of imaging biomarkers is increasing, as illustrated by the diagnosis of breast and prostate cancers. KEY POINTS: · Imaging biomarkers are quantitative parameters to detect physiological and pathophysiological processes.. · Imaging biomarkers from multimodality and multiparametric imaging are integrated using artificial intelligence algorithms.. · Quantitative imaging parameters are a fundamental component of diagnostics for all tumor entities, such as for mammary and prostate carcinomas.. CITATION FORMAT: · Bäuerle T, Dietzel M, Pinker K et al. Identification of impactful imaging biomarker: Clinical applications for breast and prostate carcinoma. Fortschr Röntgenstr 2024; 196: 354 - 362.


Assuntos
Carcinoma , Medicina Nuclear , Neoplasias da Próstata , Humanos , Masculino , Inteligência Artificial , Biomarcadores , Imageamento por Ressonância Magnética/métodos , Próstata/diagnóstico por imagem , Próstata/patologia , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Feminino
12.
Eur Radiol ; 23(10): 2652-7, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23660774

RESUMO

OBJECTIVE: To evaluate the association between aortic arch calcifications (AAC) on chest radiography and coronary artery calcium (CAC) score determined by CT. METHODS: A total of 128 patients (75 men; 69.3 ± 14.7 years) who underwent chest radiography and CAC scoring at CT were included in this retrospective analysis. The extent of AAC on chest radiography was evaluated independently by two blinded observers using a semi-quantitative four-point scale (0-3). Intra- and interobserver agreement was assessed by weighted ĸ statistics. Amount of AAC determined on radiography was correlated with CAC and ROC analyses performed to characterise the diagnostic performance of AAC grading. RESULTS: Excellent intraobserver (ĸ = 0.82) and good interobserver (ĸ = 0.75) agreement of AAC grading was noted. Moderate agreement (ĸ = 0.46, 95 % CI 0.36-0.56) with a linear trend (P < 0.0001) between AAC grades and CAC scores was found. Cut-off between AAC grades 0-2 and 3 had a sensitivity of 38.6 %, specificity of 96.4 %, PPV of 85.0 %, NPV of 75.0 % and accuracy of 76.6 % for the correct identification of CAC scores greater than 400. CONCLUSION: Semi-quantitative AAC grading on chest radiography is reliable and positively associated with CAC scoring. We propose to report the extent of AAC in comprehensive radiological reports as "not present", "moderate" or "severe", as severe AAC strongly suggests coronary artery calcification. KEY POINTS: • Semi-quantitative aortic arch calcification (AAC) grading on plain chest radiography appears reliable. • AAC grading is positively associated with CT coronary artery calcium scoring. • AAC grading has a high specificity for ruling out CAC scores greater than 400. • We propose the reporting of the extent of AAC grade in chest X-ray (CXR) reports.


Assuntos
Doenças da Aorta/diagnóstico por imagem , Doenças da Aorta/epidemiologia , Calcinose/diagnóstico por imagem , Calcinose/epidemiologia , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/epidemiologia , Idoso , Aorta Torácica/diagnóstico por imagem , Comorbidade , Angiografia Coronária/estatística & dados numéricos , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Prevalência , Radiografia Torácica/estatística & dados numéricos , Reprodutibilidade dos Testes , Fatores de Risco , Sensibilidade e Especificidade
13.
Commun Biol ; 6(1): 605, 2023 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-37277453

RESUMO

The cerebellum regulates nonmotor behavior, but the routes of influence are not well characterized. Here we report a necessary role for the posterior cerebellum in guiding a reversal learning task through a network of diencephalic and neocortical structures, and in flexibility of free behavior. After chemogenetic inhibition of lobule VI vermis or hemispheric crus I Purkinje cells, mice could learn a water Y-maze but were impaired in ability to reverse their initial choice. To map targets of perturbation, we imaged c-Fos activation in cleared whole brains using light-sheet microscopy. Reversal learning activated diencephalic and associative neocortical regions. Distinctive subsets of structures were altered by perturbation of lobule VI (including thalamus and habenula) and crus I (including hypothalamus and prelimbic/orbital cortex), and both perturbations influenced anterior cingulate and infralimbic cortex. To identify functional networks, we used correlated variation in c-Fos activation within each group. Lobule VI inactivation weakened within-thalamus correlations, while crus I inactivation divided neocortical activity into sensorimotor and associative subnetworks. In both groups, high-throughput automated analysis of whole-body movement revealed deficiencies in across-day behavioral habituation to an open-field environment. Taken together, these experiments reveal brainwide systems for cerebellar influence that affect multiple flexible responses.


Assuntos
Encéfalo , Cerebelo , Camundongos , Animais , Cerebelo/fisiologia , Córtex Cerebelar , Células de Purkinje , Aprendizagem
14.
J Vis Exp ; (179)2022 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-35129170

RESUMO

Climbing fiber inputs to Purkinje cells provide instructive signals critical for cerebellum-dependent associative learning. Studying these signals in head-fixed mice facilitates the use of imaging, electrophysiological, and optogenetic methods. Here, a low-cost behavioral platform (~$1000) was developed that allows tracking of associative learning in head-fixed mice that locomote freely on a running wheel. The platform incorporates two common associative learning paradigms: eyeblink conditioning and delayed tactile startle conditioning. Behavior is tracked using a camera and the wheel movement by a detector. We describe the components and setup and provide a detailed protocol for training and data analysis. This platform allows the incorporation of optogenetic stimulation and fluorescence imaging. The design allows a single host computer to control multiple platforms for training multiple animals simultaneously.


Assuntos
Cerebelo , Células de Purkinje , Animais , Piscadela , Condicionamento Clássico , Camundongos , Optogenética , Células de Purkinje/fisiologia
15.
STAR Protoc ; 3(2): 101289, 2022 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-35496792

RESUMO

Transsynaptic viral tracing requires tissue sectioning, manual cell counting, and anatomical assignment, all of which are time intensive. We describe a protocol for BrainPipe, a scalable software for automated anatomical alignment and object counting in light-sheet microscopy volumes. BrainPipe can be generalized to new counting tasks by using a new atlas and training a neural network for object detection. Combining viral tracing, iDISCO+ tissue clearing, and BrainPipe facilitates mapping of cerebellar connectivity to the rest of the murine brain. For complete details on the use and execution of this protocol, please refer to Pisano et al. (2021).


Assuntos
Encéfalo , Cerebelo , Animais , Encéfalo/diagnóstico por imagem , Camundongos , Microscopia de Fluorescência/métodos , Software
16.
Sci Rep ; 11(1): 4848, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33649416

RESUMO

This methodical work describes the measurement and calculation of pulmonary blood volume in mice based on two imaging techniques namely by using magnetic particle imaging (MPI) and cardiac magnetic resonance imaging (MRI). Besides its feasibility aspects that may influence quantitative analysis are studied. Eight FVB mice underwent cardiac MRI to determine stroke volumes and anatomic MRI as morphological reference for functional MPI data. Arrival time analyses of boli of 1 µl of 1 M superparamagnetic tracer were performed by MPI. Pulmonary transit time of the bolus was determined by measurements in the right and left ventricles. Pulmonary blood volume was calculated out of stroke volume, pulmonary transit time and RR-interval length including a maximal error analysis. Cardiac stroke volume was 31.7 µl ± 2.3 µl with an ejection fraction of 71% ± 6%. A sharp contrast bolus profile was observed by MPI allowing subdividing the first pass into three distinct phases: tracer arrival in the right ventricle, pulmonary vasculature, and left ventricle. The bolus full width at half maximum was 578 ms ± 144 ms in the right ventricle and 1042 ms ± 150 ms in the left ventricle. Analysis of pulmonary transit time revealed 745 ms ± 81 ms. Mean RR-interval length was 133 ms ± 12 ms. Pulmonary blood volume resulted in 177 µl ± 27 µl with a mean maximal error limit of 27 µl. Non-invasive assessment of the pulmonary blood volume in mice was feasible. This technique can be of specific value for evaluation of pulmonary hemodynamics in mouse models of cardiac dysfunction or pulmonary disease. Pulmonary blood volume can complement cardiac functional parameters as a further hemodynamic parameter.


Assuntos
Volume Sanguíneo , Ventrículos do Coração/diagnóstico por imagem , Pulmão , Imageamento por Ressonância Magnética , Volume Sistólico , Função Ventricular Esquerda , Animais , Pulmão/irrigação sanguínea , Pulmão/diagnóstico por imagem , Camundongos
17.
Commun Biol ; 4(1): 1326, 2021 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-34824365

RESUMO

Patients with Alzheimer's disease (AD) often have osteoporosis or osteopenia. However, their direct link and relationship remain largely unclear. Previous studies have detected osteoporotic deficits in young adult Tg2576 and TgAPPsweOCN mice, which express APPswe (Swedish mutant) ubiquitously and selectively in osteoblast (OB)-lineage cells. This raises the question, whether osteoblastic APPswe contributes to AD development. Here, we provide evidence that TgAPPsweOCN mice also exhibit AD-relevant brain pathologies and behavior phenotypes. Some brain pathologies include age-dependent and regional-selective increases in glial activation and pro-inflammatory cytokines, which are accompanied by behavioral phenotypes such as anxiety, depression, and altered learning and memory. Further cellular studies suggest that APPswe, but not APPwt or APPlon (London mutant), in OB-lineage cells induces endoplasmic reticulum-stress driven senescence, driving systemic and cortex inflammation as well as behavioral changes in 6-month-old TgAPPsweOCN mice. These results therefore reveal an unrecognized function of osteoblastic APPswe to brain axis in AD development.


Assuntos
Doença de Alzheimer/fisiopatologia , Precursor de Proteína beta-Amiloide/genética , Encéfalo/fisiopatologia , Senescência Celular/genética , Fenótipo , Doença de Alzheimer/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Ansiedade/genética , Citocinas/fisiologia , Depressão/genética , Humanos , Aprendizagem , Masculino , Memória , Camundongos , Camundongos Transgênicos , Mutação , Neuroglia/fisiologia , Osteoblastos
18.
Clin Endocrinol (Oxf) ; 73(1): 78-84, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20039897

RESUMO

OBJECTIVE: Optimal diagnostic criteria for the 4-mg intravenous dexamethasone suppression test (IVDST) in patients with Cushing's syndrome (CS), compared with normal subjects, have not been established. We evaluated the performance of the 4-mg IVDST for differentiating CS from normal subjects and to define the responses in CS of various aetiologies. DESIGN, SUBJECTS, MEASUREMENTS: Thirty-two control subjects [normal and overweight/obese participants with or without type 2 diabetes) were prospectively studied, and data from 66 patients with Cushing's disease (CD), three with ectopic ACTH syndrome (EAS), 14 with adrenal Cushing's (AC)] and 15 with low probability of CS (LPC) from three tertiary hospitals were retrospectively evaluated. Dexamethasone was infused at 1 mg/h for 4 h. Plasma cortisol and ACTH were measured at -60 min (baseline), -5 min, +3 h, +4 h, +5 h and at +23 and +23.5 h on Day 2. RESULTS: Control subjects (including those with type 2 diabetes) exhibited a marked suppression of cortisol which was maintained until Day 2. Two of 15 patients with LPC had Day 2 cortisol results that overlapped with CS. Patients with CD demonstrated partial suppression, with rebound hypercortisolism on Day 2. Patients with AC and EAS did not suppress cortisol levels. Day 2 cortisol level of >130 nmol/l (or >20% of the baseline) diagnosed CS with 100% sensitivity and 96% specificity. CONCLUSION: While the IVDST allowed complete discrimination between control subjects and CS, 13% of LPC overlapped with CS. Given the small number of EAS, no conclusion can be drawn regarding the utility of this test in the differential diagnosis of CS.


Assuntos
Síndrome de Cushing/diagnóstico , Dexametasona , Síndrome de ACTH Ectópico/diagnóstico , Hormônio Adrenocorticotrópico/sangue , Adulto , Idoso , Síndrome de Cushing/sangue , Feminino , Humanos , Hidrocortisona/sangue , Masculino , Pessoa de Meia-Idade
19.
Res Gerontol Nurs ; : 1-7, 2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-32101320

RESUMO

Oral hygiene is difficult to achieve for frail older adults. Aging, chronic diseases, polypharmacy, mouth-washes, and crushed drugs can contribute to uncontrolled proliferation and microbial deposits in the mouth. Looking for avoidable risk factors, in vitro microbial survival or proliferation in thickened drinks and oral nutritional supplements (ONS) was investigated. The safest thickened drinks were ready-to-use products containing preservatives. Escherichia coli, Staphylococcus aureus, and Candida albicans proliferated in dairy ONS at room temperature. C. albicans also proliferated in juices. Oral anerobic bacteria were recovered from part eaten ONS. Thickened drinks and ONS could contribute to microbial proliferation, especially with patients who have swallowing alterations or cognitive troubles, who may keep these solutions longer than necessary in their mouth. These products can also constitute microbial reservoirs in the environment of frail older adults. It is important for health care workers and family members to respect hand hygiene and refrigeration procedures. [Research in Gerontological Nursing, xx(x), xx-xx.].

20.
Phys Med Biol ; 63(6): 064001, 2018 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-29465412

RESUMO

Magnetic particle imaging (MPI) is a new imaging technology. It is a potential candidate to be used for angiographic purposes, to study perfusion and cell migration. The aim of this work was to measure velocities of the flowing blood in the inferior vena cava of mice, using MPI, and to evaluate it in comparison with magnetic resonance imaging (MRI). A phantom mimicking the flow within the inferior vena cava with velocities of up to 21 cm s-1 was used for the evaluation of the applied analysis techniques. Time-density and distance-density analyses for bolus tracking were performed to calculate flow velocities. These findings were compared with the calibrated velocities set by a flow pump, and it can be concluded that velocities of up to 21 cm s-1 can be measured by MPI. A time-density analysis using an arrival time estimation algorithm showed the best agreement with the preset velocities. In vivo measurements were performed in healthy FVB mice (n = 10). MRI experiments were performed using phase contrast (PC) for velocity mapping. For MPI measurements, a standardized injection of a superparamagnetic iron oxide tracer was applied. In vivo MPI data were evaluated by a time-density analysis and compared to PC MRI. A Bland-Altman analysis revealed good agreement between the in vivo velocities acquired by MRI of 4.0 ± 1.5 cm s-1 and those measured by MPI of 4.8 ± 1.1 cm s-1. Magnetic particle imaging is a new tool with which to measure and quantify flow velocities. It is fast, radiation-free, and produces 3D images. It therefore offers the potential for vascular imaging.


Assuntos
Hemodinâmica , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética/métodos , Imagem Molecular/métodos , Imagens de Fantasmas , Animais , Velocidade do Fluxo Sanguíneo , Camundongos
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