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2.
Ann Neurol ; 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31970803

RESUMO

OBJECTIVE: Recessive null variants of the slow skeletal muscle troponin T1 (TNNT1) gene are a rare cause of nemaline myopathy that is fatal in infancy due to respiratory insufficiency. Muscle biopsy shows rods and fiber type disproportion. We report on 4 French Canadians with a novel form of recessive congenital TNNT1 core-rod myopathy. METHODS: Patients underwent full clinical characterization, lower limb magnetic resonance imaging (MRI), muscle biopsy, and genetic testing. A zebrafish loss-of-function model using morpholinos was created to assess the pathogenicity of the identified variant. Wild-type or mutated human TNNT1 mRNAs were coinjected with morpholinos to assess their abilities to rescue the morphant phenotype. RESULTS: Three adults and 1 child shared a novel missense homozygous variant in the TNNT1 gene (NM_003283.6: c.287T > C; p.Leu96Pro). They developed from childhood very slowly progressive limb-girdle weakness with rigid spine and disabling contractures. They suffered from restrictive lung disease requiring noninvasive mechanical ventilation in 3 patients, as well as recurrent episodes of rhabdomyolysis triggered by infections, which were relieved by dantrolene in 1 patient. Older patients remained ambulatory into their 60s. MRI of the leg muscles showed fibrofatty infiltration predominating in the posterior thigh and the deep posterior leg compartments. Muscle biopsies showed multiminicores and lobulated fibers, rods in half the patients, and no fiber type disproportion. Wild-type TNNT1 mRNA rescued the zebrafish morphants, but mutant transcripts failed to do so. INTERPRETATION: This study expands the phenotypic spectrum of TNNT1 myopathy and provides functional evidence for the pathogenicity of the newly identified missense mutation. ANN NEUROL 2020.

3.
Arthritis Res Ther ; 22(1): 5, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31915059

RESUMO

OBJECTIVE: To describe successful therapeutic strategies in statin-induced anti-HMGCR myopathy. METHODS: Retrospective data from a cohort of 55 patients with statin-induced anti-HMGCR myopathy, sequentially stratified by the presence of proximal weakness, early remission, and corticosteroid and IVIG use at treatment induction, were analyzed for optimal successful induction and maintenance of remission strategies. RESULTS: A total of 14 patients achieved remission with a corticosteroid-free induction strategy (25%). In 41 patients treated with corticosteroids, only 4 patients (10%) failed an initial triple steroid/IVIG/steroid-sparing immunosuppressant (SSI) induction strategy. Delay in treatment initiation was independently associated with lower odds of successful maintenance with immunosuppressant monotherapy (OR 0.92, 95% CI 0.85 to 0.97, P = 0.015). While 22 patients (40%) presented with normal strength, only 9 had normal strength at initiation of treatment. CONCLUSION: While corticosteroid-free treatment of anti-HMGCR myopathy is now a safe option in selected cases, initial triple steroid/IVIG/SSI was very efficacious in induction. Delays in treatment initiation and, as a corollary, delays in achieving remission decrease the odds of achieving successful maintenance with an SSI alone. Avoiding such delays, most notably in patients with normal strength, may reset the natural history of anti-HMGCR myopathy from a refractory entity to a treatable disease.

4.
J Parkinsons Dis ; 10(1): 301-313, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31868683

RESUMO

BACKGROUND: Genetic, biologic and clinical data suggest that Parkinson's disease (PD) is an umbrella for multiple disorders with clinical and pathological overlap, yet with different underlying mechanisms. To better understand these and to move towards neuroprotective treatment, we have established the Quebec Parkinson Network (QPN), an open-access patient registry, and data and bio-samples repository. OBJECTIVE: To present the QPN and to perform preliminary analysis of the QPN data. METHODS: A total of 1,070 consecutively recruited PD patients were included in the analysis. Demographic and clinical data were analyzed, including comparisons between males and females, PD patients with and without RBD, and stratified analyses comparing early and late-onset PD and different age groups. RESULTS: QPN patients exhibit a male:female ratio of 1.8:1, an average age-at-onset of 58.6 years, an age-at-diagnosis of 60.4 years, and average disease duration of 8.9 years. REM-sleep behavior disorder (RBD) was more common among men, and RBD was associated with other motor and non-motor symptoms including dyskinesia, fluctuations, postural hypotension and hallucinations. Older patients had significantly higher rates of constipation and cognitive impairment, and longer disease duration was associated with higher rates of dyskinesia, fluctuations, freezing of gait, falls, hallucinations and cognitive impairment. Since QPN's creation, over 60 studies and 30 publications have included patients and data from the QPN. CONCLUSIONS: The QPN cohort displays typical PD demographics and clinical features. These data are open-access upon application (http://rpq-qpn.ca/en/), and will soon include genetic, imaging and bio-samples. We encourage clinicians and researchers to perform studies using these resources.

5.
J Neuropathol Exp Neurol ; 78(12): 1130-1146, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31665376

RESUMO

Astrocytes are increasingly recognized as active contributors to the disease process in multiple sclerosis (MS), rather than being merely reactive. We investigated the expression of a selected microRNA (miRNA) panel that could contribute both to the injury and to the recovery phases of the disease. Individual astrocytes were laser microdissected from brain sections. We then compared the miRNAs' expressions in MS and control brain samples at different lesional stages in white versus grey matter regions. In active MS lesions, we found upregulation of ischemia-related miRNAs in white but not grey matter, often with reversion to the normal state in inactive lesions. In contrast to our previous findings on MS macrophages, expression of 2 classical inflammatory-related miRNAs, miRNA-155 and miRNA-146a, was reduced in astrocytes from active and chronic active MS lesions in white and grey matter, suggesting a lesser direct pathogenetic role for these miRNAs in astrocytes. miRNAs within the categories regulating aquaporin4 (-100, -145, -320) and glutamate transport/apoptosis/neuroprotection (-124a, -181a, and -29a) showed some contrasting responses. The regional and lesion-stage differences of expression of these miRNAs indicate the remarkable ability of astrocytes to show a wide range of selective responses in the face of differing insults and phases of resolution.

6.
Sci Rep ; 9(1): 14569, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31602000

RESUMO

Despite advances in therapy, glioblastoma remains an incurable disease with a dismal prognosis. Recent studies have implicated cancer stem cells within glioblastoma (glioma stem cells, GSCs) as mediators of therapeutic resistance and tumor progression. In this study, we investigated the role of the transforming growth factor-ß (TGF-ß) superfamily, which has been found to play an integral role in the maintenance of stem cell homeostasis within multiple stem cell systems, as a mediator of stem-like cells in glioblastoma. We find that BMP and TGF-ß signaling define divergent molecular and functional identities in glioblastoma, and mark relatively quiescent and proliferative GSCs, respectively. Treatment of GSCs with BMP inhibits cell proliferation, but does not abrogate their stem-ness, as measured by self-renewal and tumorigencity. Further, BMP pathway activation confers relative resistance to radiation and temozolomide chemotherapy. Our findings define a quiescent cancer stem cell population in glioblastoma that may be a cellular reservoir for tumor recurrence following cytotoxic therapy.

8.
Front Neurol ; 10: 163, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30873111

RESUMO

Rheumatoid meningitis is a rare complication of rheumatoid arthritis (RA). It is associated with substantial morbidity and mortality. The condition may present in a variety of ways and is therefore diagnostically challenging. Uncertainty still exists regarding the optimal treatment strategy. Herein, we describe the case of a 74-year-old man with a history of well-controlled seropositive RA on low-dose prednisone, hydroxychloroquine, and methotrexate. The patient presented with a several-month history of multiple prolonged episodes of expressive aphasia, right hemiparesis, and encephalopathy. Although no epileptiform activity was recorded on repeated electroencephalography, the symptoms fully resolved following treatment with antiepileptic drugs. He subsequently developed acute asymmetrical parkinsonism of the right hemibody. Magnetic resonance imaging revealed subtle enhancement of the leptomeninges over the left frontoparietal convexity. Cerebrospinal fluid analysis revealed a mild lymphocytic pleocytosis and elevated proteins. Histopathologic analysis of a meningeal biopsy revealed nodular rheumatoid meningitis. The patient was treated with corticosteroids and cyclophosphamide, following which he incompletely recovered. This is the first description of rheumatoid meningitis manifesting with acute parkinsonism and protracted non-convulsive seizures. A summary of cases reported since 2005, including data on pathology, therapy and outcomes, along with a discussion on the efficacy of different treatment strategies are provided.

9.
J Clin Pathol ; 72(3): 213-220, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30467243

RESUMO

Pathology is a specialty that bridges basic medical science and clinical practice. In the era of personalised medicine, this specialty is facing unprecedented challenges. Some of these challenges are institution-specific, while many are shared worldwide at different magnitude. This review shares our team efforts in the past 5 years, 2012-2017, to revitalise a century-old academic pathology department in three aspects: administration, clinical service and academic development. The lessons learnt and insights gained from our experience may provide guidance to leaders in pathology or in other related specialties.


Assuntos
Centros Médicos Acadêmicos/organização & administração , Patologia/organização & administração , Humanos
10.
J Clin Invest ; 129(1): 223-229, 2019 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-30358567

RESUMO

Replicative immortality is a hallmark of cancer cells governed by telomere maintenance. Approximately 90% of human cancers maintain their telomeres by activating telomerase, driven by the transcriptional upregulation of telomerase reverse transcriptase (TERT). Although TERT promoter mutations (TPMs) are a major cancer-associated genetic mechanism of TERT upregulation, many cancers exhibit TERT upregulation without TPMs. In this study, we describe the TERT hypermethylated oncological region (THOR), a 433-bp genomic region encompassing 52 CpG sites located immediately upstream of the TERT core promoter, as a cancer-associated epigenetic mechanism of TERT upregulation. Unmethylated THOR repressed TERT promoter activity regardless of TPM status, and hypermethylation of THOR counteracted this repressive function. THOR methylation analysis in 1,352 human tumors revealed frequent (>45%) cancer-associated DNA hypermethylation in 9 of 11 (82%) tumor types screened. Additionally, THOR hypermethylation, either independently or along with TPMs, accounted for how approximately 90% of human cancers can aberrantly activate telomerase. Thus, we propose that THOR hypermethylation is a prevalent telomerase-activating mechanism in cancer that can act independently of or in conjunction with TPMs, further supporting the utility of THOR hypermethylation as a prognostic biomarker.


Assuntos
Metilação de DNA , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Proteínas de Neoplasias/biossíntese , Regiões Promotoras Genéticas , Telomerase/biossíntese , Linhagem Celular Tumoral , Ilhas de CpG , DNA de Neoplasias/genética , DNA de Neoplasias/metabolismo , Humanos , Proteínas de Neoplasias/genética , Telomerase/genética
11.
BMC Infect Dis ; 18(1): 210, 2018 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-29739366

RESUMO

BACKGROUND: Angiocentric lymph proliferative disorder (ALPD) is a granulomatous lymphoproliferative condition associated with various primary and secondary immunodeficiency states. ALPD is so rare that its prevalence has not been established. Typically affecting middle-aged adults, this condition is often found in the context of Epstein Bar Virus infection and consists of angiocentric and angioinvasive pulmonary infiltrates. Herein, we present a biopsy-proven case of a patient manifesting with a viral meningoencephalomyelitis-like picture with brain, spinal cord, renal and splenic lesions. The diagnosis was confirmed to be ALPD in the context of newly diagnosed HIV infection. CASE PRESENTATION: A 35 year-old homosexual man presented with a 5-week history of headaches followed by a 3-week history of horizontal diplopia, limb weakness and right 6th cranial nerve palsy. Lumbar puncture revealed a lymphocytic pleocytosis, high protein and low glucose. Magnetic Resonance Imaging showed scattered lesions throughout the brain and spinal cord and Computed Tomography of the abdomen and pelvis revealed hypodensities involving the kidneys and spleen. HIV testing was positive, with a viral load of 11,096 copies/mL and CD4 count of 324 cells/µL. Serum Epstein Bar virus PCR was positive with 12,434 copies/ml. Right frontal brain biopsy revealed gray matter containing angiogentric cerebritis with organizing infarction but Epstein Bar Virus-in situ preparations were negative and no viral inclusions were identified. A diagnosis of ALPD (also known as lymphomatoid granulomatosis) was made. The patient was initiated on antiretroviral therapy and treated with intravenous rituximab every 3 weeks for 4 cycles and made progressive improvements. By the time of discharge his strength had improved and he was ambulating again although with a walker. Within 2 months, his HIV viral load was suppressed. Magnetic Resonance Imaging of the brain 6 months later revealed interval improvement. At his most recent follow-up, 34 months later, his neurological symptoms had almost completed resolved. CONCLUSION: Albeit rare, ALPD should be considered in the differential diagnosis of central nervous system lesions in persons with HIV once common etiologies have been eliminated. Furthermore, ALPD involving the central nervous system may occur in in the absence of documented EBV infection in the central nervous system.


Assuntos
Encéfalo/patologia , Infecções por HIV/tratamento farmacológico , Granulomatose Linfomatoide/etiologia , Medula Espinal/patologia , Adulto , Antineoplásicos Imunológicos/uso terapêutico , Encéfalo/diagnóstico por imagem , Homossexualidade Masculina , Humanos , Linfócitos/patologia , Granulomatose Linfomatoide/diagnóstico por imagem , Granulomatose Linfomatoide/tratamento farmacológico , Imagem por Ressonância Magnética , Masculino , Rituximab/uso terapêutico , Medula Espinal/diagnóstico por imagem , Tomografia Computadorizada por Raios X
12.
Ann Neurol ; 83(6): 1089-1095, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29518281

RESUMO

VPS13 protein family members VPS13A through VPS13C have been associated with various recessive movement disorders. We describe the first disease association of rare recessive VPS13D variants including frameshift, missense, and partial duplication mutations with a novel complex, hyperkinetic neurological disorder. The clinical features include developmental delay, a childhood onset movement disorder (chorea, dystonia, or tremor), and progressive spastic ataxia or paraparesis. Characteristic brain magnetic resonance imaging shows basal ganglia or diffuse white matter T2 hyperintensities as seen in Leigh syndrome and choreoacanthocytosis. Muscle biopsy in 1 case showed mitochondrial aggregates and lipidosis, suggesting mitochondrial dysfunction. These findings underline the importance of the VPS13 complex in neurological diseases and a possible role in mitochondrial function. Ann Neurol 2018;83:1089-1095.


Assuntos
Deficiência Intelectual/genética , Transtornos dos Movimentos/genética , Espasticidade Muscular/genética , Mutação/genética , Atrofia Óptica/genética , Proteínas/genética , Ataxias Espinocerebelares/genética , Gânglios da Base/patologia , Encéfalo/patologia , Criança , Humanos , Doença de Leigh/patologia , Imagem por Ressonância Magnética/métodos , Espasticidade Muscular/patologia , Linhagem
14.
Acta Neuropathol Commun ; 5(1): 78, 2017 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-29084603

RESUMO

Pediatric high-grade gliomas (pHGGs) are aggressive neoplasms representing approximately 20% of brain tumors in children. Current therapies offer limited disease control, and patients have a poor prognosis. Empiric use of targeted therapy, especially at progression, is increasingly practiced despite a paucity of data regarding temporal and therapy-driven genomic evolution in pHGGs. To study the genetic landscape of pHGGs at recurrence, we performed whole exome and methylation analyses on matched primary and recurrent pHGGs from 16 patients. Tumor mutational profiles identified three distinct subgroups. Group 1 (n = 7) harbored known hotspot mutations in Histone 3 (H3) (K27M or G34V) or IDH1 (H3/IDH1 mutants) and co-occurring TP53 or ACVR1 mutations in tumor pairs across the disease course. Group 2 (n = 7), H3/IDH1 wildtype tumor pairs, harbored novel mutations in chromatin modifiers (ZMYND11, EP300 n = 2), all associated with TP53 alterations, or had BRAF V600E mutations (n = 2) conserved across tumor pairs. Group 3 included 2 tumors with NF1 germline mutations. Pairs from primary and relapsed pHGG samples clustered within the same DNA methylation subgroup. ATRX mutations were clonal and retained in H3G34V and H3/IDH1 wildtype tumors, while different genetic alterations in this gene were observed at diagnosis and recurrence in IDH1 mutant tumors. Mutations in putative drug targets (EGFR, ERBB2, PDGFRA, PI3K) were not always shared between primary and recurrence samples, indicating evolution during progression. Our findings indicate that specific key driver mutations in pHGGs are conserved at recurrence and are prime targets for therapeutic development and clinical trials (e.g. H3 post-translational modifications, IDH1, BRAF V600E). Other actionable mutations are acquired or lost, indicating that re-biopsy at recurrence will provide better guidance for effective targeted therapy of pHGGs.


Assuntos
Neoplasias Encefálicas/genética , Glioma/genética , Recidiva Local de Neoplasia/genética , Adolescente , Adulto , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Criança , Pré-Escolar , Metilação de DNA , Epigênese Genética , Feminino , Regulação Neoplásica da Expressão Gênica , Glioma/metabolismo , Glioma/patologia , Humanos , Masculino , Mutação , Gradação de Tumores , Recidiva Local de Neoplasia/metabolismo , Recidiva Local de Neoplasia/patologia , Estudos Retrospectivos , Adulto Jovem
15.
Can J Neurol Sci ; 44(3): 288-294, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28488951

RESUMO

BACKGROUND: Radiotherapy with procarbazine, lomustine, and vincristine improves overall survival (OS) in patients with 1p19q co-deleted anaplastic oligodendroglioma/anaplastic oligoastrocytoma. METHODS: This retrospective analysis investigated outcomes in patients with 1p19q co-deleted/partially deleted oligodendroglioma, oligoastrocytoma, anaplastic oligodendroglioma, or anaplastic oligoastrocytoma. OS and progression-free survival (PFS) were analyzed using the Kaplan-Meier method and prognostic factors using the Cox proportional hazard model. RESULTS: A total of 106 patients (between December 1997 and December 2013) were included. Median age was 40 years (19-66), 58 were male (55%), Eastern Cooperative Oncology Group performance status was 0 in 80 patients (75%). 1p19q status was co-deleted in 66 (62%), incompletely co-deleted in 27 (25%), and 1p or 19q loss alone in four (4%) and nine (8%) patients, respectively. Isocitrate dehydrogenase-1 R132H mutation was found in 67 of 85 patients with sufficient material. Upfront treatment was given in 72 (68%) patients and temozolomide alone in 52 (49%). Median time to radiotherapy in 47 patients (44%) was 34.7 months and 41.2 months in 9 patients with co-deleted/incompletely co-deleted anaplastic oligodendroglioma/anaplastic oligoastrocytoma who received upfront temozolomide alone. Median OS was not reached and 5-year OS was 91% for all groups (median follow-up, 5.1 years). On multivariable analysis for all patients, receipt of therapy upfront versus none (p=0.04), PS 1 versus 0 (p<0.001) and 1p19q co-deletion/incomplete deletion versus 1p or 19q loss alone (p=0.005) were prognostic for PFS. Isocitrate dehydrogenase-1 status was not prognostic for PFS. CONCLUSIONS: With similar survival patterns in low-grade/anaplastic gliomas, molecular characteristics may be more important than histological grade. Longer follow-up and results of prospective trials are needed for definitive guidance on treatment of these patients.


Assuntos
Neoplasias Encefálicas/genética , Deleção Cromossômica , Cromossomos Humanos Par 19/genética , Cromossomos Humanos Par 1/genética , Glioma/genética , Adulto , Idoso , Astrocitoma/genética , Astrocitoma/mortalidade , Astrocitoma/terapia , Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/terapia , Feminino , Seguimentos , Glioma/mortalidade , Glioma/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Oligodendroglioma/genética , Oligodendroglioma/mortalidade , Oligodendroglioma/terapia , Estudos Retrospectivos , Taxa de Sobrevida/tendências , Resultado do Tratamento
16.
Clin Neuropathol ; 36(5): 240-245, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28502321

RESUMO

Congenital cytomegalovirus (CMV) infection in the 2nd and 3rd trimester results in catastrophic CNS abnormalities. This susceptibility is thought to result from the high proportion of neural stem cells in the developing brain. In immunocompromised adults, CNS infection by CMV preferentially affects ependymal surfaces, from where it expands to involve the parenchyma. Experimental models of murine CMV infection demonstrate viral tropism for the dentate gyrus (DG) and subventricular zone, the areas in which adult neurogenesis occurs. We present two cases of CMV infection of the DG of immunocompromised allogeneic stem cell transplant recipients. Both cases showed CMV-positive neurons in the DG granular cell layer, as well as contiguous layers. The majority of infected cells contained Nissl substance and expressed nestin, glial fibrillary acidic protein (GFAP), neuron-specific enolase (NSE), and neurofilament. These cases demonstrate that CMV infects the DG in humans. Co-expression of nestin and GFAP, indicative of early neurogenesis, is consistent with experimental models showing neural stem cells as the target of CMV, providing further histological evidence of neurogenesis in the human dentate. Finally, the cases suggest that CMV infection produces abnormal migration of newly formed neurons as evidenced by the finding of virally infected neurons in the molecular layer of the dentate.
.


Assuntos
Infecções por Citomegalovirus/virologia , Giro Denteado/virologia , Células-Tronco Neurais/virologia , Adulto , Citomegalovirus , Infecções por Citomegalovirus/imunologia , Humanos , Hospedeiro Imunocomprometido , Masculino , Pessoa de Meia-Idade , Transplante de Células-Tronco
17.
Nat Genet ; 49(2): 180-185, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28067913

RESUMO

Human papillomavirus (HPV)-negative head and neck squamous cell carcinomas (HNSCCs) are deadly and common cancers. Recent genomic studies implicate multiple genetic pathways, including cell signaling, cell cycle and immune evasion, in their development. Here we analyze public data sets and uncover a previously unappreciated role of epigenome deregulation in the genesis of 13% of HPV-negative HNSCCs. Specifically, we identify novel recurrent mutations encoding p.Lys36Met (K36M) alterations in multiple H3 histone genes. histones. We further validate the presence of these alterations in multiple independent HNSCC data sets and show that, along with previously described NSD1 mutations, they correspond to a specific DNA methylation cluster. The K36M substitution and NSD1 defects converge on altering methylation of histone H3 at K36 (H3K36), subsequently blocking cellular differentiation and promoting oncogenesis. Our data further indicate limited redundancy for NSD family members in HPV-negative HNSCCs and suggest a potential role for impaired H3K36 methylation in their development. Further investigation of drugs targeting chromatin regulators is warranted in HPV-negative HNSCCs driven by aberrant H3K36 methylation.


Assuntos
Carcinoma de Células Escamosas/genética , Metilação de DNA/genética , Neoplasias de Cabeça e Pescoço/genética , Histonas/genética , Carcinogênese/genética , Diferenciação Celular/genética , Epigênese Genética/genética , Histona Metiltransferases , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Mutação/genética , Proteínas Nucleares/genética , Papillomaviridae/patogenicidade , Infecções por Papillomavirus/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço
18.
Endocr Pathol ; 28(4): 308-314, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28084610

RESUMO

We report two different cases of IgG4-related hypophysitis. In the first case, a pituitary lesion was accompanied by lymphocytic meningitis possibly mimicking tuberculous meningitis. The second case was unassociated with involvement of other organs. No histologic differences were noted between the two cases indicating that the morphologic features of the hypophysial lesion do not depend on the presence of other lesions. The pathogenesis of IgG4 hypophysitis is not known, and further study is necessary to explore the cause, progression, and influencing factors of this disease.


Assuntos
Hipofisite Autoimune , Adulto , Hipofisite Autoimune/patologia , Hipofisite Autoimune/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
19.
Brain ; 140(1): 37-48, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27816943

RESUMO

Congenital myopathies define a heterogeneous group of neuromuscular diseases with neonatal or childhood hypotonia and muscle weakness. The genetic cause is still unknown in many patients, precluding genetic counselling and better understanding of the physiopathology. To identify novel genetic causes of congenital myopathies, exome sequencing was performed in three consanguineous families. We identified two homozygous frameshift mutations and a homozygous nonsense mutation in the mitogen-activated protein triple kinase ZAK. In total, six affected patients carry these mutations. Reverse transcription polymerase chain reaction and transcriptome analyses suggested nonsense mRNA decay as a main impact of mutations. The patients demonstrated a generalized slowly progressive muscle weakness accompanied by decreased vital capacities. A combination of proximal contractures with distal joint hyperlaxity is a distinct feature in one family. The low endurance and compound muscle action potential amplitude were strongly ameliorated on treatment with anticholinesterase inhibitor in another patient. Common histopathological features encompassed fibre size variation, predominance of type 1 fibre and centralized nuclei. A peculiar subsarcolemmal accumulation of mitochondria pointing towards the centre of the fibre was a novel histological hallmark in one family. These findings will improve the molecular diagnosis of congenital myopathies and implicate the mitogen-activated protein kinase (MAPK) signalling as a novel pathway altered in these rare myopathies.


Assuntos
Fibras Musculares de Contração Rápida/patologia , Fibras Musculares de Contração Lenta/patologia , Miopatias Congênitas Estruturais , Proteínas Quinases/genética , Adulto , Consanguinidade , Exoma , Feminino , Humanos , Masculino , Mutação , Miopatias Congênitas Estruturais/genética , Miopatias Congênitas Estruturais/patologia , Miopatias Congênitas Estruturais/fisiopatologia , Linhagem
20.
Nat Commun ; 7: 11185, 2016 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-27048880

RESUMO

Diffuse Intrinsic Pontine Gliomas (DIPGs) are deadly paediatric brain tumours where needle biopsies help guide diagnosis and targeted therapies. To address spatial heterogeneity, here we analyse 134 specimens from various neuroanatomical structures of whole autopsy brains from nine DIPG patients. Evolutionary reconstruction indicates histone 3 (H3) K27M--including H3.2K27M--mutations potentially arise first and are invariably associated with specific, high-fidelity obligate partners throughout the tumour and its spread, from diagnosis to end-stage disease, suggesting mutual need for tumorigenesis. These H3K27M ubiquitously-associated mutations involve alterations in TP53 cell-cycle (TP53/PPM1D) or specific growth factor pathways (ACVR1/PIK3R1). Later oncogenic alterations arise in sub-clones and often affect the PI3K pathway. Our findings are consistent with early tumour spread outside the brainstem including the cerebrum. The spatial and temporal homogeneity of main driver mutations in DIPG implies they will be captured by limited biopsies and emphasizes the need to develop therapies specifically targeting obligate oncohistone partnerships.


Assuntos
Neoplasias do Tronco Encefálico/genética , Carcinogênese/genética , Regulação Neoplásica da Expressão Gênica , Glioma/genética , Histonas/genética , Mutação , Receptores de Ativinas Tipo I/genética , Receptores de Ativinas Tipo I/metabolismo , Autopsia , Mapeamento Encefálico , Tronco Encefálico/metabolismo , Tronco Encefálico/patologia , Neoplasias do Tronco Encefálico/metabolismo , Neoplasias do Tronco Encefálico/patologia , Carcinogênese/metabolismo , Carcinogênese/patologia , Cérebro/metabolismo , Cérebro/patologia , Criança , Evolução Clonal , Glioma/metabolismo , Glioma/patologia , Histonas/metabolismo , Humanos , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Fosfoproteínas Fosfatases/genética , Fosfoproteínas Fosfatases/metabolismo , Proteína Fosfatase 2C , Transdução de Sinais , Técnicas Estereotáxicas , Fatores de Tempo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
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