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1.
J Pediatr Gastroenterol Nutr ; 78(3): 534-538, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38327256

RESUMO

In 2022, there were global reports of increased numbers of acute hepatitis not explained by hepatitis A-E virus infection in children. This manuscript summarises histopathology results from 20 patients in the United Kingdom who underwent liver transplant or had a liver biopsy as part of aetiological investigations. All available histopathological samples were reviewed centrally as part of the outbreak investigation. A working group comprised of infection specialists, hepatologists and histopathologists met virtually to review the cases, presentation, investigations and histopathology. All 20 liver samples had evidence of inflammation without significant interface activity, and submassive confluent pan-lobular or multilobular hepatocellular necrosis. Overall, the predominant histopathological findings were of acute nonspecific hepatitis with submassive hepatic necrosis and central vein perivenulitis and endothelitis. Histopathological findings were a poor indicator of aetiology.


Assuntos
Hepatite , Hepatopatias , Transplante de Fígado , Humanos , Criança , Fígado/patologia , Hepatite/patologia , Hepatopatias/patologia , Biópsia
2.
Mem Cognit ; 52(4): 926-943, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38622490

RESUMO

Several lines of research have shown that performing movements while learning new information aids later retention of that information, compared to learning by perception alone. For instance, articulated words are more accurately remembered than words that are silently read (the production effect). A candidate mechanism for this movement-enhanced encoding, sensorimotor prediction, assumes that acquired sensorimotor associations enable movements to prime associated percepts and hence improve encoding. Yet it is still unknown how the extent of prior sensorimotor experience influences the benefits of movement on encoding. The current study addressed this question by examining whether the production effect is modified by prior language experience. Does the production effect reduce or persist in a second language (L2) compared to a first language (L1)? Two groups of unbalanced bilinguals, German (L1) - English (L2) bilinguals (Experiment 1) and English (L1) - German (L2) bilinguals (Experiment 2), learned lists of German and English words by reading the words silently or reading the words aloud, and they subsequently performed recognition tests. Both groups showed a pronounced production effect (higher recognition accuracy for spoken compared to silently read words) in the first and second languages. Surprisingly, the production effect was greater in the second languages compared to the first languages, across both bilingual groups. We discuss interpretations based on increased phonological encoding, increased effort or attention, or both, when reading aloud in a second language.


Assuntos
Multilinguismo , Leitura , Humanos , Adulto , Adulto Jovem , Reconhecimento Psicológico/fisiologia , Feminino , Masculino , Psicolinguística
3.
HPB (Oxford) ; 26(3): 344-351, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38071186

RESUMO

BACKGROUND: Diagnostic error can result in pancreatoduodenectomy (PD) being mistakenly performed for benign disease. The aims of this study were to observe the error rate in PD over three decades and identify characteristics of benign disease that can mimic malignancy. METHODS: Patients with a benign histological diagnosis after having PD performed for suspected malignancy between 1988 and 2019 were selected for review. Preoperative clinical features, imaging and pathological samples were reviewed alongside resection specimens to identify features that may have led to misdiagnosis. RESULTS: Over the study period, 1812 patients underwent PD for suspected malignancy and 97 (5.2 %) of these had a final benign diagnosis. The rate of benign cases reduced across the study period. Some 62 patients proceeded to surgery without a preoperative tissue diagnosis; the decision to operate was made upon clinical and radiologic features alone. There were six patients who had a preoperative pathological sample suspicious for malignancy, of which two had autoimmune pancreatitis in the postoperative histology specimen. DISCUSSION: Benign conditions, notably autoimmune and chronic pancreatitis, can mimic malignancy even with the use of EUS-FNA. The results of all available diagnostic modalities should be interpreted by a multidisciplinary team and honest discussions with the patient should follow.


Assuntos
Neoplasias Pancreáticas , Pancreatite Crônica , Humanos , Pancreaticoduodenectomia/efeitos adversos , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/cirurgia , Neoplasias Pancreáticas/patologia , Pancreatite Crônica/cirurgia , Aspiração por Agulha Fina Guiada por Ultrassom Endoscópico , Erros de Diagnóstico
4.
J Pediatr Gastroenterol Nutr ; 77(1): 110-114, 2023 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-36917836

RESUMO

GLI-similar 3 (GLIS3) gene mutation heterozygosity is characterized by neonatal diabetes and hypothyroidism. It has wide phenotypic variability. Liver disease is prevalent, and its complications in some phenotypes are life-limiting. Transplantation and the pathogenesis of GLIS3 liver disease are not well explored in the literature. We report 2 cases of children with GLIS3 mutations with chronic liver disease who required liver transplantation and we present a literature review discussing the pathogenic mechanisms and liver histology. Histology demonstrated predominantly biliary cirrhosis consistent with abnormal bile duct development. Both patients were considered for multi-organ transplantation (liver, pancreas with or without kidney) before receiving a liver transplant alone. Postoperative management can be challenging due to infection, renal disease, and brittle diabetes. GLIS3 mutations need to be added to the list of non-syndromic causes of bile duct paucity in the liver. Liver transplantation should be considered in patients with life-limiting complications related to liver disease.


Assuntos
Hepatopatias , Fatores de Transcrição , Humanos , Fatores de Transcrição/genética , Proteínas de Ligação a DNA/genética , Transativadores/genética , Proteínas Repressoras/genética , Ductos Biliares/cirurgia , Mutação
5.
Psychol Res ; 86(4): 1078-1096, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34185146

RESUMO

Actions we perform every day generate perceivable outcomes with both spatial and temporal features. According to the ideomotor principle, we plan our actions by anticipating the outcomes, but this principle does not directly address how sequential movements are influenced by different outcomes. We examined how sequential action planning is influenced by the anticipation of temporal and spatial features of action outcomes. We further explored the influence of action sequence switching. Participants performed cued sequences of button presses that generated visual effects which were either spatially compatible or incompatible with the sequences, and the spatial effects appeared after a short or long delay. The sequence cues switched or repeated across trials, and the predictability of action sequence switches was varied across groups. The results showed a delay-anticipation effect for sequential action, whereby a shorter anticipated delay between action sequences and their outcomes speeded initiation and execution of the cued action sequences. Delay anticipation was increased by predictable action switching, but it was not strongly modified by the spatial compatibility of the action outcomes. The results extend previous demonstrations of delay anticipation to the context of sequential action. The temporal delay between actions and their outcomes appears to be retrieved for sequential planning and influences both the initiation and the execution of actions.


Assuntos
Movimento , Desempenho Psicomotor , Cognição , Humanos
6.
J Pediatr Gastroenterol Nutr ; 72(6): 788-793, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33908737

RESUMO

ABSTRACT: The clinical impact of donor-specific antibodies (DSA) occurring before or after liver transplantation (LT) against donor-human leucocyte antigen (HLA) on graft outcome is still unclear. We aim to present the current consensus based on recent paediatric LT case series. Compared to kidney transplantation, the liver seems to be less susceptible to antibody-mediated graft damage, which is likely due to protective Kupffer cell activity. The incidence of DSA after liver transplantation is higher in children than in adults. DSA directed against HLA class II molecules, mainly DQ, occur more often. The presence of such anti-class II DSA (DQ/DR), especially of the complement-binding IgG3 subclass, may be associated with endothelial injury, T-cell-mediated rejection (TCMR), inflammation, and fibrosis. Regular DSA-posttransplant monitoring cannot as yet be recommended in routine practice but may be useful in selected cases.


Assuntos
Transplante de Fígado , Adulto , Criança , Rejeição de Enxerto/prevenção & controle , Sobrevivência de Enxerto , Antígenos HLA , Humanos , Isoanticorpos , Doadores de Tecidos
7.
Neuroophthalmology ; 45(2): 109-116, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34108782

RESUMO

Eosinophilic granulomatosis with polyangiitis (eGPA) is a rare vasculitis of small-medium sized vessels that can cause both anterior and posterior ischaemic optic neuropathies. Herein, the authors present a rare case of eGPA presenting initially as an acute unilateral anterior ischaemic optic neuropathy from short posterior ciliary artery vasculitis. The diagnosis presented a challenge as clinical and histopathological evidence suggested allergic rhinosinusitis, and no invasive fungal sinusitis was found. The high serum eosinophilia, asthma, optic neuropathy and paranasal sinus abnormalities fulfilled the criteria for a diagnosis of eGPA. Furthermore serum was positive for myeloperoxidase antibodies. Subsequently the case was successfully treated with oral glucocorticoids and intravenous rituximab.

8.
Int J Psychol ; 55(3): 342-346, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31062352

RESUMO

The informative value of time and temporal structure often remains neglected in cognitive assessments. However, next to information about stimulus identity we can exploit temporal ordering principles, such as regularity, periodicity, or grouping to generate predictions about the timing of future events. Such predictions may improve cognitive performance by optimising adaptation to dynamic stimuli. Here, we investigated the influence of temporal structure on verbal working memory by assessing immediate recall performance for aurally presented digit sequences (forward digit span) as a function of standard (1000 ms stimulus-onset-asynchronies, SOAs), short (700 ms), long (1300 ms) and mixed (700-1300 ms) stimulus timing during the presentation phase. Participant's digit spans were lower for short and mixed SOA presentation relative to standard SOAs. This confirms an impact of temporal structure on the classic "magical number seven," suggesting that working memory performance can in part be regulated through the systematic application of temporal ordering principles.


Assuntos
Cognição/fisiologia , Memória de Curto Prazo/fisiologia , Adulto , Feminino , Humanos , Masculino , Adulto Jovem
9.
J Cogn Neurosci ; 30(11): 1657-1682, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30156505

RESUMO

Humans must learn a variety of sensorimotor skills, yet the relative contributions of sensory and motor information to skill acquisition remain unclear. Here we compare the behavioral and neural contributions of perceptual learning to that of motor learning, and we test whether these contributions depend on the expertise of the learner. Pianists and nonmusicians learned to perform novel melodies on a piano during fMRI scanning in four learning conditions: listening (auditory learning), performing without auditory feedback (motor learning), performing with auditory feedback (auditory-motor learning), or observing visual cues without performing or listening (cue-only learning). Visual cues were present in every learning condition and consisted of musical notation for pianists and spatial cues for nonmusicians. Melodies were performed from memory with no visual cues and with auditory feedback (recall) five times during learning. Pianists showed greater improvements in pitch and rhythm accuracy at recall during auditory learning compared with motor learning. Nonmusicians demonstrated greater rhythm improvements at recall during auditory learning compared with all other learning conditions. Pianists showed greater primary motor response at recall during auditory learning compared with motor learning, and response in this region during auditory learning correlated with pitch accuracy at recall and with auditory-premotor network response during auditory learning. Nonmusicians showed greater inferior parietal response during auditory compared with auditory-motor learning, and response in this region correlated with pitch accuracy at recall. Results suggest an advantage for perceptual learning compared with motor learning that is both general and expertise-dependent. This advantage is hypothesized to depend on feedforward motor control systems that can be used during learning to transform sensory information into motor production.


Assuntos
Percepção Auditiva/fisiologia , Aprendizagem/fisiologia , Destreza Motora/fisiologia , Música , Desempenho Psicomotor/fisiologia , Estimulação Acústica/métodos , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Música/psicologia , Estimulação Luminosa/métodos , Adulto Jovem
10.
Lancet ; 387(10019): 679-690, 2016 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-26608256

RESUMO

BACKGROUND: Glucagon-like peptide-1 (GLP-1) analogues reduce hepatic steatosis, concentrations of liver enzymes, and insulin resistance in murine models of fatty liver disease. These analogues are licensed for type 2 diabetes, but their efficacy in patients with non-alcoholic steatohepatitis is unknown. We assessed the safety and efficacy of the long-acting GLP-1 analogue, liraglutide, in patients with non-alcoholic steatohepatitis. METHODS: This multicentre, double-blinded, randomised, placebo-controlled phase 2 trial was conducted in four UK medical centres to assess subcutaneous injections of liraglutide (1·8 mg daily) compared with placebo for patients who are overweight and show clinical evidence of non-alcoholic steatohepatitis. Patients were randomly assigned (1:1) using a computer-generated, centrally administered procedure, stratified by trial centre and diabetes status. The trial was designed using A'Hern's single-group method, which required eight (38%) of 21 successes in the liraglutide group for the effect of liraglutide to be considered clinically significant. Patients, investigators, clinical trial site staff, and pathologists were masked to treatment assignment throughout the study. The primary outcome measure was resolution of definite non-alcoholic steatohepatitis with no worsening in fibrosis from baseline to end of treatment (48 weeks), as assessed centrally by two independent pathologists. Analysis was done by intention-to-treat analysis, which included all patients who underwent end-of-treatment biopsy. The trial was registered with ClinicalTrials.gov, number NCT01237119. FINDINGS: Between Aug 1, 2010, and May 31, 2013, 26 patients were randomly assigned to receive liraglutide and 26 to placebo. Nine (39%) of 23 patients who received liraglutide and underwent end-of-treatment liver biopsy had resolution of definite non-alcoholic steatohepatitis compared with two (9%) of 22 such patients in the placebo group (relative risk 4·3 [95% CI 1·0-17·7]; p=0·019). Two (9%) of 23 patients in the liraglutide group versus eight (36%) of 22 patients in the placebo group had progression of fibrosis (0·2 [0·1-1·0]; p=0·04). Most adverse events were grade 1 (mild) to grade 2 (moderate) in severity, transient, and similar in the two treatment groups for all organ classes and symptoms, with the exception of gastrointestinal disorders in 21 (81%) of 23 patients in the liraglutide group and 17 (65%) of 22 patients in the placebo group, which included diarrhoea (ten [38%] patients in the liraglutide group vs five [19%] in the placebo group), constipation (seven [27%] vs none), and loss of appetite (eight [31%] vs two [8%]). INTERPRETATION: Liraglutide was safe, well tolerated, and led to histological resolution of non-alcoholic steatohepatitis, warranting extensive, longer-term studies. FUNDING: Wellcome Trust, National Institute of Health Research, and Novo Nordisk.


Assuntos
Incretinas/administração & dosagem , Liraglutida/administração & dosagem , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Adolescente , Adulto , Idoso , Diabetes Mellitus Tipo 2/complicações , Método Duplo-Cego , Feminino , Humanos , Incretinas/efeitos adversos , Injeções Subcutâneas , Liraglutida/efeitos adversos , Masculino , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/complicações , Resultado do Tratamento , Adulto Jovem
11.
Ann Rheum Dis ; 76(7): 1161-1168, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27965259

RESUMO

Labial salivary gland (LSG) biopsy is used in the classification of primary Sjögren's syndrome (PSS) and in patient stratification in clinical trials. It may also function as a biomarker. The acquisition of tissue and histological interpretation is variable and needs to be standardised for use in clinical trials. A modified European League Against Rheumatism consensus guideline development strategy was used. The steering committee of the ad hoc working group identified key outstanding points of variability in LSG acquisition and analysis. A 2-day workshop was held to develop consensus where possible and identify points where further discussion/data was needed. These points were reviewed by a subgroup of experts on PSS histopathology and then circulated via an online survey to 50 stakeholder experts consisting of rheumatologists, histopathologists and oral medicine specialists, to assess level of agreement (0-10 scale) and comments. Criteria for agreement were a mean score ≥6/10 and 75% of respondents scoring ≥6/10. Thirty-nine (78%) experts responded and 16 points met criteria for agreement. These points are focused on tissue requirements, identification of the characteristic focal lymphocytic sialadenitis, calculation of the focus score, identification of germinal centres, assessment of the area of leucocyte infiltration, reporting standards and use of prestudy samples for clinical trials. We provide standardised consensus guidance for the use of labial salivary gland histopathology in the classification of PSS and in clinical trials and identify areas where further research is required to achieve evidence-based consensus.


Assuntos
Centro Germinativo/patologia , Linfócitos/patologia , Glândulas Salivares Menores/patologia , Sialadenite/patologia , Síndrome de Sjogren/patologia , Biópsia , Técnica Delphi , Humanos , Leucócitos/patologia , Lábio , Padrões de Referência
13.
HPB (Oxford) ; 19(8): 727-734, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28522378

RESUMO

BACKGROUND: Evidence associates various biometric and histological variables such as steatosis and absence of fibrosis as risk factors for post-operative pancreatic fistula (POPF) after pancreatoduodenectomy (PD). Following distal pancreatectomy (DP), the association between these factors and POPF is less clear. This study of patients, drawn from the same background population, undergoing PD or DP at a single centre is a comparative study of the risk factors for POPF after these two operations. METHODS: Associations between POPF and patient characteristics, pre-operative blood tests, data from pre-operative computed tomography (CT) imaging, assessment of histological steatosis and fibrosis were explored. RESULTS: 26/107 (24%) and 26/90 (29%) patients developed POPF after PD and DP respectively. Absence of fibrosis was associated with POPF (p < 0.001) after PD and its presence correlated with pancreatic duct width (p < 0.001). Steatosis was not associated with POPF (p = 0.910). Multivariable analysis showed pancreatic duct width (p = 0.016) and fibrosis (p = 0.025) to be independent predictors of POPF after PD. The only variable associated with POPF after DP was underlying pathology (p = 0.005). CONCLUSION: Pancreatic duct width is the most important variable related to POPF after PD and is correlated with fibrosis. Steatosis was not related to POPF. In contrast, after DP POPF appears to be related to the underlying disease.


Assuntos
Pancreatectomia/efeitos adversos , Ductos Pancreáticos/cirurgia , Fístula Pancreática/etiologia , Pancreaticoduodenectomia/efeitos adversos , Adulto , Idoso , Biomarcadores/sangue , Bases de Dados Factuais , Inglaterra , Feminino , Fibrose , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Ductos Pancreáticos/diagnóstico por imagem , Ductos Pancreáticos/patologia , Fístula Pancreática/diagnóstico , Estudos Retrospectivos , Fatores de Risco , Tomografia Computadorizada por Raios X , Resultado do Tratamento
14.
Fam Pract ; 33(5): 523-8, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27418587

RESUMO

BACKGROUND: Type II diabetes continues to be a major health problem in USA, particularly in minority populations. The Diabetes Equity Project (DEP), a clinic-based diabetes self-management and education program led by community health workers (CHWs), was designed to reduce observed disparities in diabetes care and outcomes in medically underserved, predominantly Hispanic communities. OBJECTIVE: The purpose of this study was to evaluate the impact of the DEP on patients' clinical outcomes, diabetes knowledge, self-management skills, and quality of life. METHODS: The DEP was implemented in five community clinics from 2009 to 2013 and 885 patients completed at least two visits with the CHW. Student's paired t-tests were used to compare baseline clinical indicators with indicators obtained from patients' last recorded visit with the CHW and to assess differences in diabetes knowledge, perceived competence in managing diabetes, and quality of life. A mixed-effects model for repeated measures was used to examine the effect of DEP visits on blood glucose (HbA1c), controlling for patient demographics, clinic and enrolment date. RESULTS: DEP patients experienced significant (P < 0.0001) improvements in HbA1c control, blood pressure, diabetes knowledge, perceived competence in managing diabetes, and quality of life. Mean HbA1c for all DEP patients decreased from 8.3% to 7.4%. CONCLUSION: Given the increasing prevalence of diabetes in USA and documented disparities in diabetes care and outcomes for minorities, particularly Hispanic patients, new models of care such as the DEP are needed to expand access to and improve the delivery of diabetes care and help patients achieve improved outcomes.


Assuntos
Agentes Comunitários de Saúde , Atenção à Saúde/normas , Diabetes Mellitus Tipo 2/terapia , Conhecimentos, Atitudes e Prática em Saúde , Adulto , Feminino , Hemoglobinas Glicadas/análise , Hispânico ou Latino/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Qualidade de Vida , Autocuidado/métodos , Texas/epidemiologia , Fatores de Tempo , Resultado do Tratamento , Populações Vulneráveis
16.
Ann Rheum Dis ; 74(9): 1645-50, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26034044

RESUMO

Salivary gland changes, characterised by a focal lymphocytic sialadenitits, play an important role in the diagnosis of primary Sjögren's syndrome (PSS) and were first described over 40 years ago. Recent evidence suggests that minor salivary gland biopsy may also provide information useful for prognostication and stratification, yet difficulties may arise in the histopathological interpretation and scoring, and evidence exists that reporting is variable. With the increasing number of actual and proposed clinical trials in PSS, we review the evidence that might support the role of histopathology as a biomarker for stratification and response to therapy and highlight areas where further validation work is required.


Assuntos
Glândulas Salivares/patologia , Síndrome de Sjogren/patologia , Biópsia , Ensaios Clínicos como Assunto , Humanos , Prognóstico , Síndrome de Sjogren/terapia , Resultado do Tratamento
18.
Clin Cancer Res ; 30(2): 356-367, 2024 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-37870417

RESUMO

PURPOSE: While there are several prognostic classifiers, to date, there are no validated predictive models that inform treatment selection for oropharyngeal squamous cell carcinoma (OPSCC).Our aim was to develop clinical and/or biomarker predictive models for patient outcome and treatment escalation for OPSCC. EXPERIMENTAL DESIGN: We retrospectively collated clinical data and samples from a consecutive cohort of OPSCC cases treated with curative intent at ten secondary care centers in United Kingdom and Poland between 1999 and 2012. We constructed tissue microarrays, which were stained and scored for 10 biomarkers. We then undertook multivariable regression of eight clinical parameters and 10 biomarkers on a development cohort of 600 patients. Models were validated on an independent, retrospectively collected, 385-patient cohort. RESULTS: A total of 985 subjects (median follow-up 5.03 years, range: 4.73-5.21 years) were included. The final biomarker classifier, comprising p16 and survivin immunohistochemistry, high-risk human papillomavirus (HPV) DNA in situ hybridization, and tumor-infiltrating lymphocytes, predicted benefit from combined surgery + adjuvant chemo/radiotherapy over primary chemoradiotherapy in the high-risk group [3-year overall survival (OS) 63.1% vs. 41.1%, respectively, HR = 0.32; 95% confidence interval (CI), 0.16-0.65; P = 0.002], but not in the low-risk group (HR = 0.4; 95% CI, 0.14-1.24; P = 0.114). On further adjustment by propensity scores, the adjusted HR in the high-risk group was 0.34, 95% CI = 0.17-0.67, P = 0.002, and in the low-risk group HR was 0.5, 95% CI = 0.1-2.38, P = 0.384. The concordance index was 0.73. CONCLUSIONS: We have developed a prognostic classifier, which also appears to demonstrate moderate predictive ability. External validation in a prospective setting is now underway to confirm this and prepare for clinical adoption.


Assuntos
Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Neoplasias Orofaríngeas , Infecções por Papillomavirus , Humanos , Carcinoma de Células Escamosas de Cabeça e Pescoço , Prognóstico , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/terapia , Carcinoma de Células Escamosas/genética , Estudos Retrospectivos , Estudos Prospectivos , Neoplasias Orofaríngeas/diagnóstico , Neoplasias Orofaríngeas/terapia , Neoplasias Orofaríngeas/patologia , Biomarcadores
19.
J Cogn Neurosci ; 25(2): 313-28, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23163413

RESUMO

Music performance requires control of two sequential structures: the ordering of pitches and the temporal intervals between successive pitches. Whether pitch and temporal structures are processed as separate or integrated features remains unclear. A repetition suppression paradigm compared neural and behavioral correlates of mapping pitch sequences and temporal sequences to motor movements in music performance. Fourteen pianists listened to and performed novel melodies on an MR-compatible piano keyboard during fMRI scanning. The pitch or temporal patterns in the melodies either changed or repeated (remained the same) across consecutive trials. We expected decreased neural response to the patterns (pitch or temporal) that repeated across trials relative to patterns that changed. Pitch and temporal accuracy were high, and pitch accuracy improved when either pitch or temporal sequences repeated over trials. Repetition of either pitch or temporal sequences was associated with linear BOLD decrease in frontal-parietal brain regions including dorsal and ventral premotor cortex, pre-SMA, and superior parietal cortex. Pitch sequence repetition (in contrast to temporal sequence repetition) was associated with linear BOLD decrease in the intraparietal sulcus (IPS) while pianists listened to melodies they were about to perform. Decreased BOLD response in IPS also predicted increase in pitch accuracy only when pitch sequences repeated. Thus, behavioral performance and neural response in sensorimotor mapping networks were sensitive to both pitch and temporal structure, suggesting that pitch and temporal structure are largely integrated in auditory-motor transformations. IPS may be involved in transforming pitch sequences into spatial coordinates for accurate piano performance.


Assuntos
Córtex Auditivo/fisiologia , Música , Inibição Neural/fisiologia , Percepção da Altura Sonora/fisiologia , Percepção do Tempo/fisiologia , Estimulação Acústica/métodos , Adolescente , Adulto , Mapeamento Encefálico/métodos , Feminino , Lobo Frontal/fisiologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Córtex Motor/fisiologia , Lobo Parietal/fisiologia , Desempenho Psicomotor/fisiologia , Adulto Jovem
20.
Liver Int ; 33(4): 624-32, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23356584

RESUMO

BACKGROUND: Adult non-alcoholic fatty liver disease (NAFLD) involves lobular necroinflammatory activity and fibrosis is typically centrilobular, whereas paediatric NAFLD has predominantly portal fibrosis. The reasons for these differences are unclear. We aimed to determine (a) how centrilobular and portal fibrosis in children relate to histological parameters; and (b) whether atypical fibrosis patterns exist in adults that are unexplained by current fibrogenesis models. METHODS: Histological features of paediatric (n = 38) and adult (n = 56) NAFLD were assessed using conventional scoring systems. Keratin-7 immunostaining was used to assess hepatic progenitor cell numbers and the ductular reaction. Centrilobular and portal components of fibrosis were independently scored and fibrosis patterns were classified according to accepted types. Post-treatment (rosiglitazone/gastric banding) biopsies were also examined in adults. RESULTS: Twenty-six children (68.4%) had portal-predominant fibrosis, although the typical "adult" pattern was seen in 11 (28.9%). Portal fibrosis was associated with a ductular reaction (P = 0.021) and hepatic progenitor cell expansion (P < 0.001), whereas centrilobular fibrosis was associated with lobular inflammation (P = 0.026) and ballooning (P = 0.001). Before intervention, six adults (10.7%) had atypical fibrosis including 3 (5.4%) with a previously unrecognized pattern of very fine, non-zonal sinusoidal fibrosis. Despite improvements in steatosis and inflammation, more patients developed this unusual pattern after intervention with most having had surgery (9 of 10 adults; P < 0.001). CONCLUSION: Differing associations with portal and centrilobular fibrosis in children and atypical fibrosis patterns in adults suggest that multiple fibrogenic pathways exist in NAFLD. This has implications for therapy and understanding pathogenesis.


Assuntos
Fígado Gorduroso/complicações , Cirrose Hepática/etiologia , Fígado/patologia , Adolescente , Adulto , Fatores Etários , Austrália , Ductos Biliares Intra-Hepáticos/química , Ductos Biliares Intra-Hepáticos/patologia , Biomarcadores/análise , Biópsia , Proliferação de Células , Criança , Pré-Escolar , Europa (Continente) , Fígado Gorduroso/metabolismo , Fígado Gorduroso/patologia , Fígado Gorduroso/terapia , Derivação Gástrica , Humanos , Imuno-Histoquímica , Queratina-7/análise , Fígado/química , Fígado/efeitos dos fármacos , Cirrose Hepática/classificação , Cirrose Hepática/metabolismo , Cirrose Hepática/patologia , Cirrose Hepática/terapia , Missouri , Hepatopatia Gordurosa não Alcoólica , Fatores de Risco , Rosiglitazona , Células-Tronco/química , Células-Tronco/patologia , Tiazolidinedionas/uso terapêutico , Resultado do Tratamento
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