RESUMO
Ectopic cerebellar tissue has only been described in isolated case reports, with only two reported cases in adult patients. We report the case of a 63-year-old woman with progressive, medically refractory headaches. A scan showed an intraosseous lesion of the midline occipital bone. Surgical resection of the soft tissue lesion was undertaken. Her headaches ceased postoperatively. Histopathological analysis revealed cerebellar cortical tissue with a surrounding meningothelial cell layer, characteristic of cerebellar ectopia. This is the second reported case of an intraosseous location of this lesion, and only the third case described in an adult patient. Our findings illustrate a rare cause of headaches and support the therapeutic roles of surgical treatment for this extremely rare condition.
RESUMO
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
RESUMO
OBJECTIVE: The far-lateral and extreme-lateral infrajugular transcondylar-transtubercular exposure (ELITE) and extreme-lateral transcondylar transodontoid (ELTO) approaches provide access to lesions of the foramen magnum, inferolateral to mid-clivus, and ventral pons and medulla. A subset of pathologies in this region require manipulation of the vertebral artery (VA)-dural interface. Although a cuff of dura is commonly left on the VA to avoid vessel injury during these approaches, there are varying descriptions of the degree of VA-dural separation that is safely achievable. In this paper the authors provide a detailed histological analysis of the VA-dural junction to guide microsurgical technique for posterolateral skull base approaches. METHODS: An ELITE approach was performed on 6 preserved adult cadaveric specimens. The VA-dural entry site was resected, processed for histological analysis, and qualitatively assessed by a neuropathologist. RESULTS: Histological analysis demonstrated a clear delineation between the intima and media of the VA in all specimens. No clear plane was identified between the connective tissue of the dura and the connective tissue of the VA adventitia. CONCLUSIONS: The VA forms a contiguous plane with the connective tissue of the dura at its dural entry site. When performing posterolateral skull base approaches requiring manipulation of the VA-dural interface, maintenance of a dural cuff on the VA is critical to minimize the risk of vascular injury.
RESUMO
The clinical management and therapy of many solid tumor malignancies depends on detection of medically actionable or diagnostically relevant genetic variation. However, a principal challenge for genetic assays from tumors is the fragmented and chemically damaged state of DNA in formalin-fixed, paraffin-embedded (FFPE) samples. From highly fragmented DNA and RNA there is no current technology for generating long-range DNA sequence data as is required to detect genomic structural variation or long-range genotype phasing. We have developed a high-throughput chromosome conformation capture approach for FFPE samples that we call Fix-C, which is similar in concept to Hi-C. Fix-C enables structural variation detection from archival FFPE samples. This method was applied to 15 clinical adenocarcinoma- and sarcoma-positive control specimens spanning a broad range of tumor purities. In this panel, Fix-C analysis achieves a 90% concordance rate with fluorescence in situ hybridization assays, the current clinical gold standard. In addition, novel structural variation undetected by other methods could be identified, and long-range chromatin configuration information recovered from these FFPE samples harboring highly degraded DNA. This powerful approach will enable detailed resolution of global genome rearrangement events during cancer progression from FFPE material and will inform the development of targeted molecular diagnostic assays for patient care.
Assuntos
Neoplasias/genética , Inclusão em Parafina/métodos , Fixação de Tecidos/métodos , DNA de Neoplasias/genética , Rearranjo Gênico/genética , HumanosRESUMO
PurposeThe 2015 American College of Medical Genetics and Genomics-Association for Molecular Pathology (ACMG-AMP) guidelines were a major step toward establishing a common framework for variant classification. In practice, however, several aspects of the guidelines lack specificity, are subject to varied interpretations, or fail to capture relevant aspects of clinical molecular genetics. A simple implementation of the guidelines in their current form is insufficient for consistent and comprehensive variant classification.MethodsWe undertook an iterative process of refining the ACMG-AMP guidelines. We used the guidelines to classify more than 40,000 clinically observed variants, assessed the outcome, and refined the classification criteria to capture exceptions and edge cases. During this process, the criteria evolved through eight major and minor revisions.ResultsOur implementation: (i) separated ambiguous ACMG-AMP criteria into a set of discrete but related rules with refined weights; (ii) grouped certain criteria to protect against the overcounting of conceptually related evidence; and (iii) replaced the "clinical criteria" style of the guidelines with additive, semiquantitative criteria.ConclusionSherloc builds on the strong framework of 33 rules established by the ACMG-AMP guidelines and introduces 108 detailed refinements, which support a more consistent and transparent approach to variant classification.
Assuntos
Testes Genéticos/normas , Variação Genética/genética , Genoma Humano , Genômica/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Análise de Sequência de DNA/normas , SoftwareRESUMO
Array comparative genomic hybridization (aCGH) is now commonly used to identify copy number changes in individuals with developmental delay, intellectual disabilities, autism spectrum disorders, and/or multiple congenital anomalies. We report on an infant with multiple congenital anomalies and a novel 2.6 Mb interstitial deletion within 9q21.32q21.33 detected by aCGH. Her clinical presentation included dysmorphic craniofacial features, cleft palate, atrial septal defect, bicornuate uterus, bilateral hip dislocation, hypotonia, and recurrent pneumonia. Parental aCGH studies were negative for copy loss in this region. To our knowledge, no similar deletions have been reported in available databases or published literature. This deletion encompasses 12 genes, and prediction algorithms as well as experimental data suggest that a subset is likely to be haploinsufficient. Included are a neurotrophin receptor (NKG2D), a gene implicated in cilia function (KIF27), an adaptor protein important for ubiquitin-dependent protein quality control (UBQLN1), a gene important for transcription and signaling (HNRNPK), and a gene involved in maintaining genomic stability (RMI1). Identifying additional patients with similar copy losses and further study of these genes will contribute to a better understanding of the pathophysiology of multiple congenital anomalies.
Assuntos
Anormalidades Múltiplas/diagnóstico , Anormalidades Múltiplas/genética , Deleção Cromossômica , Cromossomos Humanos Par 9 , Hibridização Genômica Comparativa , Fácies , Evolução Fatal , Feminino , Deleção de Genes , Humanos , Lactente , FenótipoRESUMO
Using a Drosophila model of Alzheimer's disease (AD), we systematically evaluated 67 candidate genes based on AD-associated genomic loci (P < 10(-4)) from published human genome-wide association studies (GWAS). Genetic manipulation of 87 homologous fly genes was tested for modulation of neurotoxicity caused by human Tau, which forms neurofibrillary tangle pathology in AD. RNA interference (RNAi) targeting 9 genes enhanced Tau neurotoxicity, and in most cases reciprocal activation of gene expression suppressed Tau toxicity. Our screen implicates cindr, the fly ortholog of the human CD2AP AD susceptibility gene, as a modulator of Tau-mediated disease mechanisms. Importantly, we also identify the fly orthologs of FERMT2 and CELF1 as Tau modifiers, and these loci have been independently validated as AD susceptibility loci in the latest GWAS meta-analysis. Both CD2AP and FERMT2 have been previously implicated with roles in cell adhesion, and our screen additionally identifies a fly homolog of the human integrin adhesion receptors, ITGAM and ITGA9, as a modifier of Tau neurotoxicity. Our results highlight cell adhesion pathways as important in Tau toxicity and AD susceptibility and demonstrate the power of model organism genetic screens for the functional follow-up of human GWAS.
Assuntos
Doença de Alzheimer/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Proteínas tau/genética , Animais , Animais Geneticamente Modificados , Antígeno CD11b/genética , Modelos Animais de Doenças , Proteínas de Drosophila/metabolismo , Técnicas de Silenciamento de Genes , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Integrinas/genética , Interferência de RNARESUMO
Gliosarcoma, a biphasic tumor with both mesenchymal and glial elements, is typically considered a variant of astrocytoma (glioblastoma), WHO Grade IV. A 57-year-old man presented with altered mental status and was found to have a large right frontal mass. Biopsy and subsequent subtotal resection revealed a WHO Grade II oligodendroglioma with classic histological features, expression of IDH1 R132H mutant protein, and chromosome 1p19q co-deletion. Fifteen months later, the patient developed recurrent tumor composed of intersecting fascicles of spindled cells with necrosis and a high mitotic index. The recurrent tumor stained for both mesenchymal and glial elements, consistent with the diagnosis of gliosarcoma, and showed retained IDH1 R132H expression. By FISH analysis, the gliosarcoma showed no evidence of 1p19q co-deletion. We performed SNP arrays and detailed SNP analysis of both the oligodendroglioma and the gliosarcoma. This demonstrated loss of heterozygosity (LOH) of chromosomes 1 and 19 in the gliosarcoma with retention of the same full-length chromosomes 1 and 19 found intact in the oligodendroglioma. Not surprisingly, the gliosarcoma harbored multiple additional alterations, consistent with clonal evolution. There have been only rare reports of sarcomatous transformation of oligodendroglioma ("oligosarcoma") and most were published prior to the development of modern genetic modalities. Here we present a case with detailed genetic evidence that suggests that mesenchymal metaplasia sarcomatous transformation is possible in classic oligodendrogliomas with 1p19q codeletions.
Assuntos
Neoplasias Encefálicas/patologia , Gliossarcoma/patologia , Segunda Neoplasia Primária/patologia , Oligodendroglioma/patologia , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Gliossarcoma/genética , Gliossarcoma/metabolismo , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente , Masculino , Pessoa de Meia-Idade , Segunda Neoplasia Primária/genética , Segunda Neoplasia Primária/metabolismo , Oligodendroglioma/genética , Oligodendroglioma/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Polimorfismo de Nucleotídeo ÚnicoRESUMO
The distinction of multifocal versus multicentric gliomas can conceivably have important therapeutic implications. We present a 27-year-old man with two radiologically distinct non-enhancing infiltrative masses in the anterior frontal lobe and the posterior temporoparietal region. No intervening disease was evident on MRI modalities; the lesions were stable over a period of many months. He underwent two separate resections a few months apart. Given the question of whether his tumors represented two de novo primary multicentric tumors or one multifocal tumor, single nucleotide polymorphism (SNP) array karyotyping and in situ hybridization studies were performed on both tumors. The two tumor profiles looked remarkably similar, histologically and genetically: both were anaplastic astrocytomas with a common 33Mb gain/ amplification of 8q23.3-q24.3, including MYC amplification, suggesting a monoclonal origin. The temporoparietal neoplasm showed several additional genetic alterations. This case illustrates that even with today's advanced neuroimaging modalities, extensive radiologically invisible tumor may be present between seemingly separate sites of glioma involvement. Thus modern global genomic studies of such tumors may help distinguish whether multiple tumors represent one extensive neoplasm with microscopically invasive disease or multiple genetically distinct tumors.
Assuntos
Astrocitoma/genética , Astrocitoma/patologia , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Cromossomos Humanos Par 8/genética , Amplificação de Genes , Genes myc/genética , Adulto , Regulação Neoplásica da Expressão Gênica , Humanos , Hibridização in Situ Fluorescente , Cariotipagem , Masculino , Polimorfismo de Nucleotídeo ÚnicoRESUMO
Oncocytoma, chromophobe renal cell carcinoma (chRCC), and the eosinophilic variant of clear cell RCC (ccRCC) are morphologically similar tumors with significantly different clinical courses. These renal tumor subtypes show characteristic structural genetic changes; however, the mRNA expression patterns of oncocytoma and chRCC are strikingly similar. MicroRNAs (miRNA) are small RNA molecules that regulate the expression of many genes and have been shown to be useful for tumor classification and identification. The miRNA expression was analyzed from formalin-fixed paraffin-embedded tissue in 5 cases each of oncocytoma, ccRCC, papillary RCC, chRCC, and 4 normal kidney tissues using microarrays. Affymetrix single-nucleotide polymorphism arrays were used to detect chromosomal imbalances in each of the tumors. Eighteen miRNAs were significantly different among the 4 tumor types. The microRNA miR-21, a known oncogenic miRNA, was found to be upregulated in papillary and clear cell carcinomas. Four miRNAs could differentiate oncocytomas from chRCCs and the 3 could differentiate papillary RCC from ccRCC, including miR-126, a known vasculogenic miRNA. Of the 18 differentially expressed miRNAs, only 2 correlated with copy number changes in the chromosomal region harboring these genes. One tumor, originally diagnosed as an oncocytoma by morphology, showed a virtual karyotype and miRNA expression pattern consistent with chromophobe carcinoma. Further investigation of the tumor showed vascular invasion. Our study suggests that miRNA expression can be used to differentiate the common subtypes of renal epithelial neoplasms but further validation is necessary. In addition, the lack of correlation between miRNA expression and virtual karyotype suggests a non-copy-number-related mechanism for miRNA gene expression regulation in renal neoplasia.
Assuntos
Neoplasias Renais/patologia , MicroRNAs/biossíntese , Análise em Microsséries/métodos , Neoplasias Epiteliais e Glandulares/patologia , Humanos , Cariotipagem/métodos , Neoplasias Renais/classificação , Neoplasias Renais/genética , MicroRNAs/genética , Neoplasias Epiteliais e Glandulares/classificação , Neoplasias Epiteliais e Glandulares/genéticaRESUMO
Gliosarcoma is a variant of glioblastoma and is characterized by distinct glial and sarcomatous components. Typically, there is no macroscopic boundary between the components and special stains are often required to distinguish the glial and sarcomatous elements. Some studies suggest similar genetic alterations in both components pointing to a common origin. We present an extreme case of gliosarcoma arising as a discrete fibrous nodule adjacent to a typical glioblastoma. A 65 year-old woman presented with progressive weakness, seizures and right-sided hemiparesis. CT scan demonstrated an irregular enhancing left frontal lobe mass and an adjacent discrete nodule with different imaging characteristics. The unique nature of this macroscopically biphasic neoplasm allowed us to compare the molecular characteristics of glial and sarcomatous elements which were strikingly similar except for small losses and gains in Chr 3. Studies are under way to determine the significance of chromosome 3 alterations in gliosarcomas.
Assuntos
Neoplasias Encefálicas/patologia , Lobo Frontal/patologia , Glioblastoma/patologia , Gliossarcoma/etiologia , Gliossarcoma/patologia , Idoso , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Neoplasias Encefálicas/complicações , Neoplasias Encefálicas/metabolismo , Feminino , Lobo Frontal/metabolismo , Glioblastoma/complicações , Glioblastoma/metabolismo , Gliossarcoma/metabolismo , Humanos , Técnicas Imunoenzimáticas , PrognósticoRESUMO
BACKGROUND: Binding of a ligand to the epidermal growth factor receptor (EGFR) stimulates various intracellular signaling pathways resulting in cell cycle progression, proliferation, angiogenesis and apoptosis inhibition. KRAS is involved in signaling pathways including RAF/MAPK and PI3K and mutations in this gene result in constitutive activation of these pathways, independent of EGFR activation. Seven mutations in codons 12 and 13 of KRAS comprise around 95% of the observed human mutations, rendering monoclonal antibodies against EGFR (e.g. cetuximab and panitumumab) useless in treatment of colorectal cancer. METHODS: KRAS mutation testing by two different methodologies was compared; Sanger sequencing and AutoGenomics INFINITI® assay, on DNA extracted from colorectal cancers. RESULTS: Out of 29 colorectal tumor samples tested, 28 were concordant between the two methodologies for the KRAS mutations that were detected in both assays with the INFINITI® assay detecting a mutation in one sample that was indeterminate by Sanger sequencing and a third methodology; single nucleotide primer extension. CONCLUSIONS: This study indicates the utility of the AutoGenomics INFINITI® methodology in a clinical laboratory setting where technical expertise or access to equipment for DNA sequencing does not exist.
Assuntos
Neoplasias Colorretais/genética , Genes ras , Mutação , Receptores ErbB/genética , Humanos , Sistema de Sinalização das MAP Quinases , Reação em Cadeia da PolimeraseRESUMO
Myxoid liposarcoma is a subtype of liposarcoma with a predilection for the deep soft tissues of the extremities that accounts approximately for 10% of all adult soft tissue sarcomas. We report a case of a metastatic myxoid liposarcoma to the parotid gland, with fine-needle aspiration cytology correlation and molecular characterization. The lesion was diagnosed in a 53-year-old Hispanic male who presented with a left posterior thigh mass. A core needle biopsy established the diagnosis of myxoid liposarcoma. The patient underwent limb-sparing, wide local excision of the malignancy and later presented with an initial metastatic lesion to the parotid gland. The diagnosis of metastatic myxoid liposarcoma was rendered by fine-needle aspiration cytology with cell block preparation, and molecular confirmation. Although myxoid/round cell liposarcomas are classically described as having minimal pleomorphism on cytologic material, we encountered significant pleomorphism in our case. Therefore, a diagnosis of myxoid/round cell liposarcoma should still be a diagnostic consideration even if markedly pleomorphic cells are seen in fine-needle aspiration biopsies.
Assuntos
Lipossarcoma Mixoide/patologia , Glândula Parótida/patologia , Neoplasias das Glândulas Salivares/genética , Neoplasias das Glândulas Salivares/secundário , Sequência de Bases , Biópsia por Agulha Fina , Análise Mutacional de DNA , Humanos , Lipossarcoma Mixoide/diagnóstico , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Reprodutibilidade dos Testes , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Neoplasias das Glândulas Salivares/diagnóstico , Neoplasias das Glândulas Salivares/patologiaRESUMO
Myxoid/round cell liposarcoma is characterized by the recurrent translocations t(12;16)(q13;p11) and, less commonly, t(12;22)(q13;q12), which fuse FUS or EWSR1, respectively, to DDIT3 on chromosome 12. Although a number of different variant breakpoints have been described, greater than 90% of all cases have one of the three different FUS-DDIT3 fusions, which may have clinical significance. To identify the individual breakpoints, a sequence-specific assay such as reverse transcription-PCR (RT-PCR) is needed. In this study, we optimized primer design to develop an RT-PCR assay for the detection of the most common translocations in formalin-fixed paraffin-embedded tissue specimens. We compared our assay with primers previously published for testing formalin-fixed paraffin-embedded specimens and achieved the most consistent results with our primers. We obtained RNA from 32 MLS cases, of which 27 carried one of the three common FUS-DDIT3 chimeric transcript types. Four of the negative cases were from very small biopsies with very low RNA concentration. One case was consistently negative by RT-PCR, but showed a FUS rearrangement by fluorescent in situ hybridization, suggesting that it may harbor one of the rarer FUS-DDIT3 chimeric types. In addition to the common fusions, our assay also identified a novel FUS-DDIT3 fusion between exon 9 of FUS and exon 3 of DDIT3 in one of the cases.
Assuntos
Pontos de Quebra do Cromossomo , Primers do DNA , Lipossarcoma Mixoide/genética , Proteínas de Fusão Oncogênica/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Humanos , Hibridização in Situ Fluorescente , Translocação GenéticaRESUMO
Sarcomas are rare malignancies of mesenchymal lineage with more than 100 specific types and many benign potential mimics. In situ and precursor lesions are generally not described and thus much of molecular pathology in this field concentrates on molecular diagnosis, prognosis and determination of therapeutic targets. This chapter discusses the applications of molecular methodologies that provide insight into pathogenesis of sarcoma, and of molecular methods which are currently applied to, or will likely soon influence, the clinical management of this complex array of tumors.
Assuntos
Sarcoma/genética , Animais , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Mutação , Fusão Oncogênica , Sarcoma/classificação , Sarcoma/diagnóstico , Translocação GenéticaRESUMO
The mast cell has been associated with fibrosis in many different tissues, organs, and different disease processes including hematopoietic malignancies. Mast cells are often increased in the bone marrow of patients with primary bone marrow disorders, and patients with systemic mastocytosis often have a second concomitant neoplastic disease of the bone marrow. The goals of the current study were to determine the role the mast cell has in the pathogenesis of myeloproliferative neoplasms (MPN) and to correlate the mast cell burden with the degree of reticulin fibrosis. We used computer-assisted image analysis of bone marrow core biopsies stained for mast cell tryptase from patients with myeloproliferative neoplasms [31 cases: 12 chronic myelogenous leukemia (CML), 6 primary myelofibrosis (PMF), 4 essential thrombocythemia (ET), 4 polycythemia vera (PV), and 5 chronic myeloproliferative disorder, unclassifiable (CMPD-U)]. Although the number of cases of some subtypes of MPN was small, the results suggested that PMF and ET each had significantly more mast cells than both CML and control cases (P<0.01 and 0.05, respectively, Mann-Whitney test). CMPD-U and PV showed no significant differences from the control cases, but the CML cases had significantly fewer mast cells than our control cases (P=0.02, Mann-Whitney test). In addition, the quantity of mast cells seen in the bone marrows of MPN patients correlated with reticulin fibrosis (P=0.04, Mann-Whitney test). Our studies highlight the different mast cell quantities in different myeloproliferative neoplasms and suggest a direct role for the mast cell in intramedullary fibrosis. Further studies are warranted to confirm our observation and to study the mechanisms by which mast cells contribute to fibrosis in the MPN setting.
Assuntos
Mastócitos/patologia , Transtornos Mieloproliferativos/imunologia , Transtornos Mieloproliferativos/patologia , Reticulina/metabolismo , Fibrose , Humanos , Interpretação de Imagem Assistida por Computador , Imuno-HistoquímicaRESUMO
The supraoptic (SON) and the paraventricular (PVN) hypothalamic nuclei constitute major neuronal substrates underlying nitric oxide (NO) effects on autonomic and neuroendocrine control. Within these nuclei, constitutively produced NO restrains the firing activity of magnocellular neurosecretory and preautonomic neurons, actions thought to be mediated by a cGMP-dependent enhancement of GABAergic inhibitory transmission. In the present study, we expanded on this knowledge by performing a detailed anatomical characterization of constitutive NO-receptive, cGMP-producing neurons within the PVN. To this end, we combined tract-tracing techniques and immunohistochemistry to visualize cGMP immunoreactivity within functionally, neurochemically, and topographically discrete PVN neuronal populations in Wistar rats. Basal cGMP immunoreactivity was readily observed in the PVN, both in neuronal and vascular profiles. The incidence of cGMP immunoreactivity was significantly higher in magnocellular (69%) compared with preautonomic ( approximately 10%) neuronal populations (P < 0.01). No differences were observed between oxytocin (OT) and vasopressin (VP) magnocellular neurons. In preautonomic neurons, the incidence of cGMP was independent of their subnuclei distribution, innervated target (i.e., intermediolateral cell column, nucleus tractus solitarii, or rostral ventrolateral medulla) or their neurochemical phenotype (i.e., OT or VP). Finally, high levels of cGMP immunoreactivity were observed in GABAergic somata and terminals within the PVN of eGFP-GAD67 transgenic mice. Altogether, these data support a highly heterogeneous distribution of basal cGMP levels within the PVN and further support the notion that constitutive NO actions in the PVN involve intricate cell-cell interactions, as well as heterogeneous signaling modalities.
Assuntos
GMP Cíclico/metabolismo , Neurônios/metabolismo , Núcleo Hipotalâmico Paraventricular/metabolismo , Animais , Vias Autônomas/citologia , Vias Autônomas/metabolismo , Glutamato Descarboxilase/genética , Glutamato Descarboxilase/metabolismo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Masculino , Camundongos , Camundongos Transgênicos , Microscopia Confocal , Neurônios/citologia , Sistemas Neurossecretores/citologia , Sistemas Neurossecretores/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo I/metabolismo , Ocitocina/metabolismo , Núcleo Hipotalâmico Paraventricular/citologia , Ratos , Ratos Wistar , Vasopressinas/metabolismo , Ácido gama-Aminobutírico/metabolismoRESUMO
Functional evidence suggests that nitric oxide (NO) signalling in the rostral ventrolateral medulla (RVLM) is cGMP-dependent and that this pathway is impaired in hypertension. We examined cGMP expression as a marker of active NO signalling in the C1 region of the RVLM, comparing adult (>18 weeks) Wistar-Kyoto (WKY, n = 4) and spontaneously hypertensive rats (SHR, n = 4). Double label immunohistochemistry for cGMP-immunoreactivity (IR) and C1 neurons [as identified by phenylethanolamine N-methyltransferase (PNMT-IR) or tyrosine hydroxylase TH-IR)], or neuronal NO synthase (nNOS) neurones, failed to reveal cGMP-IR neurons in the RVLM of either strain, despite consistent detection of cGMP-IR in the nucleus ambiguus (NA). This was unchanged in the presence of isobutylmethylxanthine (IBMX; 0.5 mM, WKY, n = 4, SHR n = 2) and in young animals (WKY, 10-weeks, n = 3). Incubation of RVLM-slices (WKY, 10-weeks, n = 9) in DETA-NO (100 mum; 10 min) or NMDA (10 muM; 2 min) did not uncover cGMP-IR. In all studies, cGMP was prominent within the vasculature. Soluble guanylate cyclase (sGC)-IR was found throughout neurones of the RVLM, but did not co-localise with PNMT, TH or nNOS-IR neurons (WKY, 10-weeks, n = 6). Results indicate that within the RVLM, cGMP is not detectable using immunohistochemistry in the basal state and cannot be elicited by phosphodiesterase inhibition, NMDA receptor stimulation or NO donor application.
Assuntos
GMP Cíclico/metabolismo , Guanilato Ciclase/metabolismo , Bulbo/metabolismo , Animais , Tronco Encefálico/metabolismo , Imuno-Histoquímica , Masculino , Bulbo/citologia , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKYRESUMO
CONTEXT: Myelodysplastic syndromes (MDSs) are characterized by ineffective hematopoiesis, excessive apoptosis, and the aberrant expression of a number of cytokines. The genes encoding these cytokines are significantly polymorphic. It is unknown whether these cytokine polymorphisms are associated with, and may therefore be playing a role in the pathogenesis of, MDS. OBJECTIVE: To determine if certain polymorphisms in the tumor necrosis factor alpha (TNF-alpha) and transforming growth factor beta (TGF-beta) cytokines are overrepresented in a cohort of patients with MDSs. DESIGN: DNA was isolated from the peripheral blood or bone marrow aspirate of 21 patients with MDS. The genotypes for 4 different polymorphisms, 2 in TNFalpha and 2 in TGFbeta1, were determined using single-specific-primer polymerase chain reaction. The allele and genotype frequencies were compared with similar populations in the National Cancer Institute SNP500 database. RESULTS: In our MDS population, the -308A/A genotype of the TNFalpha gene and the TGFbeta1 allele +29T and genotype +29T/T, each associated with higher levels of expression, were overrepresented in our MDS population. CONCLUSIONS: Polymorphisms associated with increased expression in the cytokines TNFalpha and TGFbeta1 are overrepresented in the MDS population suggesting that increased TNF-alpha and TGF-beta1 activity may contribute to the susceptibility and/or pathogenesis of MDS. Further studies with larger sample sizes are warranted to confirm our observation.