RESUMO
A pathologic hallmark of Huntington disease (HD) is the presence of intraneuronal aggregates of polyglutamine-containing huntingtin protein fragments. Monoclonal antibody 1C2 is a commercial antibody to normal human TATA-binding protein that detects long stretches of glutamine residues. Using 1C2 as a surrogate marker formutant huntingtin protein, we immunostained 19 HD cases, 10 normal controls, and 10 cases of frontotemporal degeneration with ubiquitinated inclusions as diseased controls. In the HD cases, there was consistent 1C2 immunoreactivity in the neocortex, striatum, hippocampus, lateral geniculate body, basis pontis, medullary reticular formation, and cerebellar dentate nucleus. The normal and diseased controls demonstrated 1C2 immunoreactivity only in the substantia nigra, locus coeruleus, and pituitary gland. Staining of 5 HD cases and 5 normal controls revealed a less consistent and less diagnostically useful morphologic immunoreactivity profile. These results indicate that widespread 1C2 immunoreactivity is present in diverse central nervous system areas in HD, and that in the appropriate setting, 1C2 staining can be a useful tool in the postmortem diagnosis of HD when neuromelanin-containing neuronal populations are avoided.
Assuntos
Anticorpos Monoclonais , Encéfalo/metabolismo , Encéfalo/patologia , Doença de Huntington/metabolismo , Doença de Huntington/patologia , Peptídeos/imunologia , Adulto , Idoso , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Involvement of the olfactory bulb by Lewy-type alpha-synucleinopathy (LTS) is known to occur at an early stage of Parkinson's disease (PD) and Lewy body disorders and is therefore of potential usefulness diagnostically. An accurate estimate of the specificity and sensitivity of this change has not previously been available. We performed immunohistochemical alpha-synuclein staining of the olfactory bulb in 328 deceased individuals. All cases had received an initial neuropathological examination that included alpha-synuclein immunohistochemical staining on sections from brainstem, limbic and neocortical regions, but excluded olfactory bulb. These cases had been classified based on their clinical characteristics and brain regional distribution and density of LTS, as PD, dementia with Lewy bodies (DLB), Alzheimer's disease with LTS (ADLS), Alzheimer's disease without LTS (ADNLS), incidental Lewy body disease (ILBD) and elderly control subjects. The numbers of cases found to be positive and negative, respectively, for olfactory bulb LTS were: PD 55/3; DLB 34/1; ADLS 37/5; ADNLS 19/84; ILBD 14/7; elderly control subjects 5/64. The sensitivities and specificities were, respectively: 95 and 91% for PD versus elderly control; 97 and 91% for DLB versus elderly control; 88 and 91% for ADLS versus elderly control; 88 and 81% for ADLS versus ADNLS; 67 and 91% for ILBD versus elderly control. Olfactory bulb synucleinopathy density scores correlated significantly with synucleinopathy scores in all other brain regions (Spearman R values between 0.46 and 0.78) as well as with scores on the Mini-Mental State Examination and Part 3 of the Unified Parkinson's Disease Rating Scale (Spearman R -0.27, 0.35, respectively). It is concluded that olfactory bulb LTS accurately predicts the presence of LTS in other brain regions. It is suggested that olfactory bulb biopsy be considered to confirm the diagnosis in PD subjects being assessed for surgical therapy.
Assuntos
Doença por Corpos de Lewy/diagnóstico , Bulbo Olfatório/química , Bulbo Olfatório/patologia , Doença de Parkinson/diagnóstico , alfa-Sinucleína/análise , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Encéfalo/patologia , Química Encefálica , Feminino , Humanos , Imuno-Histoquímica , Doença por Corpos de Lewy/metabolismo , Doença por Corpos de Lewy/patologia , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia , Sensibilidade e EspecificidadeRESUMO
TAR DNA-binding protein 43 (TDP-43) is a major component of the inclusions in frontotemporal lobar degeneration with ubiquitinated inclusions (FTLD-U). We studied TDP-43 pathology in the hippocampus and frontal cortex of autopsy brains from patients with FTLD-U (n = 68), dementia lacking distinctive histopathology (n = 4), other neurodegenerative diseases (n = 23), and controls (n = 12) using a sensitive immunohistochemistry protocol. Marked enhancement of staining of TDP-43-positive dystrophic neurites (DNs) was obtained, and we observed 2 previously unrecognized pathologic patterns (i.e. frequent long DNs in the CA1 region and frequent dot-like DNs in the neocortical layer 2) in 39% and 15% of the FTLD-U cases, respectively. Frequent long DNs, but not dot-like DNs, were significantly associated with progranulin mutations. Based on this evaluation, 4 FTLD-U cases showed no TDP-43 pathology and were reclassified as "FTLD-U, non-TDP-43 proteinopathy," and 3 cases of dementia lacking distinctive histopathology were reclassified as FTLD-U. Of the cases with other neurodegenerative diseases, 43% showed TDP-43 pathology in the hippocampus, but only 4% showed TDP-43 pathology in the frontal cortex. No TDP-43 pathology was seen in controls. These results indicate that the sensitivity of the TDP-43 immunohistochemistry method affects both the extent and type of abnormalities detected. Moreover, assessment of abnormalities in both the hippocampus and frontal cortex may be diagnostically important in FTLD-U.
Assuntos
Proteínas de Ligação a DNA/metabolismo , Demência/metabolismo , Demência/patologia , Neuritos/metabolismo , Neuritos/patologia , Ubiquitina , Idoso , Autopsia , Feminino , Lobo Frontal/metabolismo , Lobo Frontal/patologia , Hipocampo/metabolismo , Hipocampo/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Placa Amiloide/patologia , Proteínas tau/metabolismoRESUMO
The use of alpha-synuclein immunohistochemistry has altered our concepts of the cellular pathology, anatomical distribution and prevalence of Lewy body disorders. However, the diversity of methodology between laboratories has led to some inconsistencies in the literature. Adoption of uniformly sensitive methods may resolve some of these differences. Eight different immunohistochemical methods for demonstrating alpha-synuclein pathology, developed in eight separate expert laboratories, were evaluated for their sensitivity for neuronal elements affected by human Lewy body disorders. Identical test sets of formalin-fixed, paraffin-embedded sections from subjects diagnosed neuropathologically with or without Lewy body disorders were stained with the eight methods and graded by three observers for specific and nonspecific staining. The methods did not differ significantly in terms of Lewy body counts, but varied considerably in their ability to reveal neuropil elements such as fibers and dots. One method was clearly superior for revealing these neuropil elements and the critical factor contributing to its high sensitivity was considered to be its use of proteinase K as an epitope retrieval method. Some methods, however, achieved relatively high sensitivities with optimized formic acid protocols combined with a hydrolytic step. One method was developed that allows high sensitivity with commercially available reagents.
Assuntos
Imuno-Histoquímica/métodos , Doença por Corpos de Lewy/metabolismo , alfa-Sinucleína/metabolismo , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Formaldeído , Humanos , Doença por Corpos de Lewy/patologia , Inclusão em Parafina , Patologia Clínica/normas , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Coloração e Rotulagem/métodos , Fixação de TecidosRESUMO
A recently discovered group of novel polymerases are characterized by significantly reduced fidelity of DNA synthesis in vitro. This feature is consistent with the relaxed fidelity required for the replicative bypass of various types of base damage that frequently block high fidelity replicative polymerases. The present studies demonstrate that the specialized DNA polymerase kappa (polkappa) is uniquely and preferentially expressed in the adrenal cortex and testis of the mouse, as well as in a variety of other tissues. The adrenal cortex is the sole site of detectable expression of the Polkappa gene in mouse embryos. This adrenal expression pattern is consistent with a requirement for polkappa for the replicative bypass of DNA base damage generated during steroid biosynthesis. The expression pattern of polkappa in the testis is specific for particular stages of spermatogenesis and is distinct from the expression pattern of several other low fidelity DNA polymerases that are also expressed during spermatogenesis. The mouse (but not the human) Polkappa gene is primarily regulated by the p53 gene and is upregulated in response to exposure to various DNA-damaging agents in a p53-dependent manner.
Assuntos
DNA Polimerase Dirigida por DNA/genética , Regulação da Expressão Gênica/fisiologia , Córtex Suprarrenal/metabolismo , Animais , Dano ao DNA/fisiologia , DNA Polimerase Dirigida por DNA/biossíntese , Humanos , Técnicas In Vitro , Masculino , Camundongos , Camundongos Transgênicos , Mutação , Especificidade de Órgãos , Testículo/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismoRESUMO
The clinical and biologic relevance of the t(14;18) and features of germinal center (GC) differentiation in diffuse large B-cell lymphoma (DLBCL) remain controversial. The authors examined the association of t(14;18) with GC-associated markers and clinical features in 44 de novo DLBCLs (22 nodal and 22 primary extranodal). CD10, bcl-2, and bcl-6 were expressed in 50%, 62%, and 54% of cases respectively. There were no significant differences in expression of these markers between nodal and extranodal cases. Coexpression of CD10 and bcl-6 was seen in 12 of 41 cases, and was more frequent in nodal than extranodal DLBCL (9 of 21 vs. 3 of 20; P = 0.05). A CD10+/bcl-6+ phenotype was not significantly associated with bcl-2 expression, stage, complete remission rate, or survival. The t(14;18) was found in 7 of 44 (16%) cases (6 nodal, 1 extranodal; P = 0.09). It was associated with a CD10+/bcl-6+ phenotype (5 of 7 vs. 7 of 27; P = 0.015) and a trend toward more frequent bcl-6 expression (6 of 7 vs. 15 of 34; P = 0.09), but no association with bcl-2 expression, CD10, clinical stage, complete remission, or survival. Among nodal or high-stage (III-IV) DLBCL, cases with the t(14;18) showed a trend toward decreased survival (P = 0.12).
Assuntos
Linfócitos B , Linfoma Difuso de Grandes Células B/genética , Translocação Genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Linfócitos B/imunologia , Linfócitos B/metabolismo , Criança , Pré-Escolar , Cromossomos Humanos Par 14 , Cromossomos Humanos Par 18 , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Feminino , Citometria de Fluxo , Humanos , Hibridização in Situ Fluorescente , Linfoma Difuso de Grandes Células B/imunologia , Linfoma Difuso de Grandes Células B/metabolismo , Linfoma Difuso de Grandes Células B/fisiopatologia , Masculino , Pessoa de Meia-Idade , Neprilisina/imunologia , Proteínas Proto-Oncogênicas c-bcl-6RESUMO
Immunohistochemical staining for beta-amyloid precursor protein (betaAPP) has been validated as a marker for axonal injury in adults surviving > or = 2 hours after white matter damage. The significance of betaAPP staining in pediatric brains and spinal cords is not as well established. We evaluated the white matter immunoreactivity for betaAPP from a variety of pediatric medicolegal autopsies: natural disease (non-Sudden Infant Death Syndrome [SIDS]), SIDS, motor vehicle accidents, drowning, near-drowning, overlay, carbon monoxide toxicity, miscellaneous trauma, and mechanical asphyxia. The cases of carbon monoxide toxicity, motor vehicle accidents (death at scene), drowning (with resuscitation), and a natural (non-SIDS) death had no significant white matter staining. The traumatic deaths with a significant survival interval, a variety of natural deaths, the near-drowning case, and surprisingly, all SIDS had detectable betaAPP white matter immunostaining. These results demonstrate that features other than traumatic axonal injury, such as metabolic insults and hypoxic-ischemic injury secondary to vascular compromise, must contribute to betaAPP immunostaining. In addition, we describe a variety of betaAPP-immunoreactive structures not previously reported in the pediatric population. This study illustrates that betaAPP immunostaining enhances detection of a variety of white matter changes, and provides a basis for interpretation of these results.
Assuntos
Precursor de Proteína beta-Amiloide/análise , Encéfalo/patologia , Medula Espinal/patologia , Coloração e Rotulagem , Precursor de Proteína beta-Amiloide/biossíntese , Autopsia , Encéfalo/metabolismo , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Estudos Prospectivos , Medula Espinal/química , Medula Espinal/metabolismo , Coloração e Rotulagem/métodosRESUMO
The formation of amyloid-containing senile plaques and tau-rich neurofibrillary tangles are central events in Alzheimer disease (AD) pathogenesis. Significantly, ABalphaC, a major protein phosphatase 2A (PP2A) holoenzyme, specifically binds to and dephosphorylates tau. Deregulation of PP2A results in tau hyperphosphorylation in vivo. Here, we compared the expression levels and distribution of PP2A subunits in various brain regions from autopsy cases of AD and aged controls with or without histological evidence of age-related neurofibrillary degeneration. Immunoblotting analyses revealed that there was a significant reduction in the total amounts of ABalphaC in AD frontal and temporal cortices that matched the decrease in PP2A activity measured in the same brain homogenates. Immunohistochemical studies showed that neuronal ABalphaC expression levels were significantly and selectively decreased in AD-affected regions and in tangle-bearing neurons, but not in AD cerebellum and in non-AD dementias. Reduced neuronal ABalphaC immunoreactivity closely correlated with tangle load, but not plaque burden, suggesting that ABalphaC dysfunction contributes to AD tau pathology. Glial cells within senile plaques were also positive for ABalphaC. Increased glial PP2A immunoreactivity was observed in both AD and non-AD cases and may play a role in the brain's response to general inflammatory processes and amyloidogenesis.
Assuntos
Doença de Alzheimer/enzimologia , Doença de Alzheimer/patologia , Encéfalo/enzimologia , Fosfoproteínas Fosfatases/biossíntese , Adulto , Idoso , Idoso de 80 Anos ou mais , Western Blotting , Encéfalo/patologia , Demência/enzimologia , Demência/patologia , Feminino , Humanos , Imuno-Histoquímica , Isoenzimas/biossíntese , Masculino , Pessoa de Meia-Idade , Emaranhados Neurofibrilares/enzimologia , Neuroglia/enzimologia , Neuroglia/patologia , Neurônios/enzimologia , Neurônios/patologia , Placa Amiloide/patologia , Proteína Fosfatase 2RESUMO
ABalphaC, a major protein phosphatase 2A (PP2A) heterotrimeric enzyme, binds to and regulates the microtubule cytoskeleton and tau. We have shown that ABalphaC protein expression levels are selectively reduced in Alzheimer disease (AD). Notably, the carboxyl methylation of PP2A catalytic subunit (PP2A(C)) is critically required for ABalphaC holoenzyme assembly, and catalyzed by a specific methyltransferase (PPMT). Here, we provide the first analysis of human PPMT and methylated PP2A(C) in brain regions from AD, non-AD demented, and aged control autopsy cases. Immunoblotting analyses revealed that PPMT protein expression and PP2A(C) methylation levels were quantitatively decreased in AD-affected brain regions. Immunohistochemical studies showed that PPMT was abundant in neurons throughout the cortex in normal control and non-AD demented cases. However, in AD, there was a regional loss of PPMT immunoreactivity that closely paralleled the severity of tau pathology, but not amyloid plaque burden. We propose that the deregulation of PPMT and PP2A methylation/demethylation cycles contributes to AD pathogenesis, by inducing changes in PP2A heteromultimeric composition and substrate specificity. In turn, PP2A dysfunction compromises the mechanisms that control tau, neuronal plasticity, and survival.
Assuntos
Doença de Alzheimer/etiologia , Dióxido de Carbono/metabolismo , Metiltransferases/metabolismo , Fosfoproteínas Fosfatases/metabolismo , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/enzimologia , Encéfalo/enzimologia , Cadáver , Estudos de Casos e Controles , Demência/enzimologia , Demência/metabolismo , Demência/patologia , Regulação para Baixo , Humanos , Metilação , Pessoa de Meia-Idade , Fosforilação , Proteína Fosfatase 2 , Distribuição Tecidual , Proteínas tau/metabolismoRESUMO
Immunohistochemical staining for beta-amyloid precursor protein (betaAPP) is a well-established marker of traumatic axonal injury in adults. Recent studies have used similar techniques to evaluate nonaccidental central nervous system injury (NAI) in infants and young children. In this prospective study, we report the results of betaAPP immunohistochemistry on the brain and spinal cord in 28 pediatric cases of NAI. BetaAPP-immunoreactive axons were present in 27/28 cases. Vascular axonal injury (VAI) due to brain swelling and secondary vascular compromise was the most common pattern of betaAPP immunoreactivity and was detected in 22 of 28 cases. Traumatic axonal injury was detected in 19/28 cases, although only eight of these cases showed brainstem staining, thus fulfilling the criteria for the diagnosis of diffuse traumatic axonal injury (dTAI). TAI and VAI were both present in 16/28 cases. Isolated TAI and VAI occurred in three and five cases, respectively. All children with isolated VAI were <18 months of age. An additional finding highlighted by betaAPP immunostaining was a penumbra of axonal injury adjacent to focal lesions, such as lacerations. We conclude that betaAPP immunohistochemistry aids in documenting trauma in nonaccidental central nervous system injury in infants and young children and that VAI is a common finding.
Assuntos
Precursor de Proteína beta-Amiloide/análise , Lesões Encefálicas/metabolismo , Encéfalo/metabolismo , Traumatismos da Medula Espinal/metabolismo , Medula Espinal/metabolismo , Fatores Etários , Precursor de Proteína beta-Amiloide/imunologia , Autopsia , Axônios/metabolismo , Lesões Encefálicas/complicações , Lesões Encefálicas/patologia , Criança , Pré-Escolar , Lesão Axonal Difusa/metabolismo , Humanos , Imuno-Histoquímica , Lactente , Estudos Prospectivos , Medula Espinal/patologia , Traumatismos da Medula Espinal/complicaçõesRESUMO
BACKGROUND AND PURPOSE: Our previous model of spinal cord injury (SCI) included six dogs undergoing 30-minute compression with a balloon in the subarachnoid space. We determined whether various balloon sizes and compression times creates a gradation of injuries. METHODS: In 17 dogs (including our original six), angioplasty balloons 2, 4, or 7 mm in diameter (2 cm long) were inflated at T6 for 30, 120, or 240 minutes. T1- and T2-weighted, gadolinium-enhanced, and short-tau inversion recovery (STIR) MR images were obtained at 1.5 T. Spinal canal occlusion (SCO) was measured as balloon area-spinal cord area. Hematoxylin-eosin and beta amyloid precursor protein staining were performed to demonstrate hemorrhage and axonal injury, respectively. Injuries were scored as mild, moderate, or severe. Trends were assessed with one-way analysis of variance. RESULTS: SCO was 12.5-20% for 2-mm balloons, 28-56% for 4 mm, and 62-82% for 7 mm. No abnormalities were seen with SCO <30%. T1- and T2-weighted images had the poorest diagnostic performance; STIR images were best for predicting hemorrhage and axonal injury. Hemorrhage was demonstrated more frequently than was axonal injury. SCO (P < .0001) and hemorrhage (P = .002) significantly increased with balloon size. Longer inflation times tended to increase injuries for a given size, but differences were not significant. CONCLUSION: Compression injuries depended on the level of SCO. The compression times tested had less effect than the degree of compression. The value of 1.5-T MR imaging varied with the sequence and improved with contrast enhancement. STIR images showed SCIs not otherwise detected.
Assuntos
Angioplastia com Balão/efeitos adversos , Modelos Animais de Doenças , Imageamento por Ressonância Magnética , Compressão da Medula Espinal/diagnóstico , Compressão da Medula Espinal/etiologia , Angioplastia com Balão/instrumentação , Animais , Meios de Contraste , Cães , Desenho de Equipamento , Masculino , Índice de Gravidade de Doença , Compressão da Medula Espinal/metabolismo , Compressão da Medula Espinal/patologia , Coloração e RotulagemRESUMO
BACKGROUND AND PURPOSE: Previous animal models for spinal cord injury required laminectomy and exposure of the spinal cord to create direct trauma, compromising imaging by both surgical artifact and the nature of the production of the injury. Our purpose was to study a model that uses percutaneous intraspinal navigation with an angioplasty balloon, providing a controlled degree of spinal cord compression and allowing improved MR imaging of spinal cord injury. METHODS: Nine mongrel dogs were studied. MR images were obtained of six dogs after technique development in three dogs. Angioplasty balloons measuring 7 or 4 mm in diameter and 2 cm in length were placed in the midthoracic subarachnoid space. Imaging was performed by using a 1.5-T MR imaging unit before and after balloon inflation. The balloon was inflated within 5 seconds and deflated after 30 minutes. T1- and T2-weighted and contrast-enhanced images were acquired. Spinal cords were submitted for pathologic examination. RESULTS: All four animals with 7-mm balloons experienced hemorrhage, and three had axonal injury revealed by histopathologic examination. One of two animals with 4-mm balloons experienced no injury, and one had axonal injury without hemorrhage. Regional parenchymal enhancement was seen in two of the animals with 7-mm balloons. CONCLUSION: This percutaneous spinal cord injury model results in a graduating degree of injury. It differs from previous techniques by avoiding surgical exposure and the associated artifacts, yet it offers histopathologic findings similar to those of human spinal cord injury. The canine spinal cord is amenable to MR imaging with clinical imaging units. Further evaluations with various durations of compression and various balloon sizes are warranted.
Assuntos
Angioplastia com Balão/instrumentação , Modelos Animais de Doenças , Imageamento por Ressonância Magnética , Procedimentos Cirúrgicos Minimamente Invasivos/instrumentação , Compressão da Medula Espinal/diagnóstico , Traumatismos da Medula Espinal/diagnóstico , Animais , Cães , Feminino , Hemorragia/diagnóstico , Hemorragia/patologia , Aumento da Imagem , Masculino , Compressão da Medula Espinal/patologia , Traumatismos da Medula Espinal/patologiaRESUMO
CONTEXT: Although the loss of B-lineage-specific gene expression is a distinctive feature of plasmablastic lymphoma, the underlying mechanism remains poorly understood. A candidate for this mechanism is Notch1 signaling, which interferes with the activity of B-cell-specific transcription factors E2A and early B-cell factor and positively regulates the mammalian target of rapamycin (mTOR) pathway. OBJECTIVE: To explore the mechanism of loss of B-cell phenotype by correlating expression of B-cell markers with that of Notch1 and downstream targets of the mTOR pathway in plasmablastic lymphoma. DESIGN: A combination of flow cytometric and immunohistochemical immunophenotyping techniques was used on 9 cases of plasmablastic lymphoma to correlate loss of B-cell markers with expression of Notch1 and downstream activation of the mTOR pathway. These results are compared with 5 cases of primary effusion lymphoma and 21 cases of plasma cell myeloma. RESULTS: Plasmablastic lymphoma cases exhibit nearly complete loss of B-cell-associated markers and uniform expression of Notch1, with a predominantly nuclear staining pattern. There is a concurrent activation of the mTOR pathway, indicated by expression of mTOR targets eukaryotic initiation factor 4E-binding protein 1 and phosphorylated ribosomal protein S6 in most cases. Similar results are seen in cases of primary effusion lymphoma and plasma cell myeloma. CONCLUSIONS: These findings suggest that activation of Notch1 may be involved in suppression of B-cell-specific gene expression and global loss of the B-cell phenotype in plasmablastic lymphoma, similar to primary effusion lymphoma and plasma cell myeloma. Thus, there might be a role for the Notch1 and mTOR pathways in the pathogenesis and therapy of plasmablastic lymphoma.
Assuntos
Biomarcadores Tumorais/metabolismo , Linfocinas/genética , Linfoma Imunoblástico de Células Grandes/metabolismo , Plasmócitos/patologia , Receptor Notch1/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Adulto , Fármacos Anti-HIV/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Terapia Antirretroviral de Alta Atividade/métodos , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Proteínas de Ciclo Celular , Feminino , Citometria de Fluxo , Soropositividade para HIV , Humanos , Imuno-Histoquímica , Imunofenotipagem , Linfoma Imunoblástico de Células Grandes/tratamento farmacológico , Linfoma Imunoblástico de Células Grandes/patologia , Linfoma de Efusão Primária/metabolismo , Linfoma de Efusão Primária/patologia , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/metabolismo , Mieloma Múltiplo/patologia , Fosfoproteínas/metabolismo , Serina-Treonina Quinases TOR/metabolismoRESUMO
Malignant rhabdoid tumors are high-grade neoplasms of the central nervous system (CNS), kidneys and soft tissue that usually occur in children. The histologic diagnosis of malignant rhabdoid tumor depends on identification of characteristic rhabdoid cells-large cells with eccentrically located nuclei and abundant, eosinophilic cytoplasm-and immunohistochemistry with antibodies to vimentin, keratin and epithelial membrane antigen. In most malignant rhabdoid tumors, the SMARCB1/INI1 gene, located in chromosome band 22q11.2, is inactivated by deletions and/or mutations, so genetic diagnosis is often possible. However, tissue may not be available for genetic analysis or studies not confirmatory. We assessed SMARCB1/INI1 expression in 17 rhabdoid tumors and 57 other tumors of the CNS, kidney or soft tissue using immunohistochemistry. In total, 12 brain, three renal and two soft tissue rhabdoid tumors were examined along with four glioblastomas, four pilocytic astrocytomas, four oligodendrogliomas, two ependymomas, two choroid plexus papillomas, five pituitary adenomas, four germinomas, four renal carcinomas with Xp11.2 translocations, two clear cell sarcomas, two Wilms' tumors, one renal medullary carcinoma, two desmoplastic small round cell tumors, two alveolar rhabdomyosarcomas, two embryonal rhabdomyosarcomas, one low-grade chondrosarcoma, two extraskeletal myxoid chondrosarcomas, one mesenchymal chondrosarcoma, four malignant peripheral nerve sheath tumors, five metastatic carcinomas and four epithelioid sarcomas, two primary and two metastatic. The neoplastic cells of all rhabdoid tumors, the four epithelioid sarcomas and the renal medullary carcinoma did not express SMARCB1/INI1 by immunohistochemistry; neoplastic cells of all other tumors expressed SMARCB1/INI1. Immunohistochemistry to assess expression of SMARCB1/INI1 may be useful in the diagnosis of rhabdoid tumors of the CNS, kidneys and soft tissue.
Assuntos
Neoplasias do Sistema Nervoso Central/patologia , Proteínas de Ligação a DNA/biossíntese , Neoplasias Renais/patologia , Tumor Rabdoide/patologia , Neoplasias de Tecidos Moles/patologia , Fatores de Transcrição/biossíntese , Adolescente , Adulto , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Neoplasias do Sistema Nervoso Central/metabolismo , Criança , Pré-Escolar , Proteínas Cromossômicas não Histona , Diagnóstico Diferencial , Feminino , Humanos , Imuno-Histoquímica , Lactente , Recém-Nascido , Neoplasias Renais/metabolismo , Masculino , Pessoa de Meia-Idade , Tumor Rabdoide/metabolismo , Proteína SMARCB1 , Neoplasias de Tecidos Moles/metabolismoRESUMO
OBJECTIVES: In some patients with gastroesophageal reflux disease (GERD), the reflux-damaged esophageal squamous epithelium heals through the process of intestinal metaplasia (resulting in Barrett's esophagus) rather than through the regeneration of more squamous cells. We hypothesized that squamous epithelium in Barrett's esophagus might have abnormalities in activation of the extracellular-regulated kinases 1 and 2 (ERK1/2) signaling pathway that may facilitate esophageal repair through metaplasia in response to acid-induced injury. METHODS: Endoscopic biopsies were taken from distal esophageal squamous mucosa in patients who had GERD with and without Barrett's esophagus and in controls, before and after esophageal perfusion with 0.1 N HCl acid. Basal ERK1/2 phosphorylation, acid-induced ERK1/2 activity and phosphorylation, and localization of phosphorylated ERK1/2 were determined using immunoblotting, Western blotting, and immunohistochemistry. RESULTS: Compared to patients with Barrett's esophagus, patients with GERD exhibited significantly lower baseline levels of phosphorylated ERK1/2 expression (35 +/- 4%vs 90 +/- 21% control, p= 0.01) Acid exposure significantly increased ERK1/2 activity (346.6 +/- 51.90 to 446.8 +/- 62.44 RIU, p= 0.02) and phosphorylation (3.55 +/- 1.26 to 4.49 +/- 1.25 [ratio phospho/total ERK], p= 0.01) in the squamous mucosa of GERD patients, but not in those with Barrett's esophagus or in controls. CONCLUSIONS: Between patients with Barrett's esophagus and patients with uncomplicated GERD, there are significant differences in baseline levels and in acid-induced activation of ERK1/2 in esophageal squamous epithelium. To our knowledge, this is the first description of a molecular, phenotypic feature that distinguishes the esophageal squamous mucosa of GERD patients with and without Barrett's esophagus.
Assuntos
Esôfago de Barrett/enzimologia , Refluxo Gastroesofágico/enzimologia , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Adulto , Idoso , Esôfago de Barrett/complicações , Biópsia , Western Blotting , Ativação Enzimática , Feminino , Humanos , Immunoblotting , Imuno-Histoquímica , Masculino , Metaplasia , Pessoa de Meia-Idade , Mucosa/enzimologia , Fosforilação , Transdução de Sinais/fisiologia , Distribuição TecidualRESUMO
OBJECTIVE: The pathologic markers of nonaccidental injury (NAI) of the central nervous system (CNS) of infants and young children include subdural, subarachnoid, and retinal hemorrhages. Immunohistochemical staining for beta-amyloid precursor protein (betaAPP) has been used to investigate traumatic axonal injury of the brain, brain stem, and spinal cord injuries, and has potential as an additional indicator of traumatic head injury. A single study has reported that betaAPP immunostaining of the optic nerve in CNS NAI reveals axonal damage. The purpose of our study was to explore further the utility of betaAPP immunostaining of optic nerves for the detection of traumatic axonal injury. METHODS: We used hematoxylin-eosin and betaAPP immunostaining to evaluate the eyes and optic nerves in 18 cases of CNS nonaccidental blunt force head injury, 4 cases of homicidal blunt force abdominal injury (BFAI), 1 homicidal suffocation, 1 case of sudden infant death syndrome, 1 near-drowning, 1 overlay (clinical history: "found under sleeping mother in bed"), 1 motor vehicle accident, and 6 natural deaths in children < or =5 years of age. RESULTS: Evaluation of the cases of CNS NAI revealed 17 of 18 (94%) with subdural hemorrhage; 15 of 18 (83%), subarachnoid hemorrhage; 17 of 18 (94%), retinal hemorrhage; 16 of 18 (88%), perioptic nerve hemorrhage; and 6 of 18 (33%), optic nerve betaAPP immunoreactive axonal swellings. The only nontraumatic case that demonstrated betaAPP immunoreactive axonal swellings was the near-drowning. No cases of BFAI, suffocation, overlay, or natural deaths revealed any retinal or perioptic nerve hemorrhage or significant optic nerve betaAPP immunoreactivity. Global hypoxic-ischemic injury was present in 21 cases, of which 19 had evidence of brain swelling, and 7 demonstrated betaAPP immunoreactive axonal swellings. CONCLUSIONS: These findings confirm the presence of optic nerve axonal injury in some cases of fatal pediatric CNS NAI.
Assuntos
Precursor de Proteína beta-Amiloide , Traumatismos do Nervo Óptico/diagnóstico , Ferimentos não Penetrantes/diagnóstico , Axônios/química , Axônios/patologia , Biomarcadores/análise , Pré-Escolar , Humanos , Imuno-Histoquímica , LactenteRESUMO
Alpha (alpha)-synuclein is a presynaptic protein, abnormal expression of which has been associated with neurodegenerative and neoplastic diseases. It is abundant in the developing vertebrate central nervous system (CNS), but less is known about its developmental expression in the human CNS. Immunohistochemical expression of alpha-synuclein was studied in 39 fetal, perinatal, pediatric, and adolescent brains. Perikaryal expression of alpha-synuclein is observed as early as 11-wk gestation in the cortical plate. Several discrete neuronal groups in the hippocampus, basal ganglia, and brain stem express perikaryal alpha-synuclein by 20-wk gestation, persisting through the first few years of life. In the cerebellum, alpha-synuclein is present by 21-wk gestation and persists into adult life as a coarse granular neuropil reaction product in the internal granular layer, and as a diffuse neuropil "blush" in the molecular layer. The germinal matrix, glia, endothelial cells, external granular layer, Pukinje cells, and dentate neurons are consistently negative for alpha-synuclein. We conclude that alpha-synuclein is expressed very early in human gestation, and that its distribution and temporal sequence of expression varies in discrete neuronal groups. Perikaryal alpha-synuclein starts disappearing from the neuronal cytosol in early childhood, and only the neuropil retains immunoreactivity into adulthood. The reappearance of alpha-synuclein in the adult neuronal cytosol in certain disease processes may represent reemergence of cues from an earlier developmental stage as part of a stress response.
Assuntos
Encéfalo/embriologia , Encéfalo/crescimento & desenvolvimento , Proteínas do Tecido Nervoso/biossíntese , Adolescente , Adulto , Criança , Pré-Escolar , Feto , Humanos , Imuno-Histoquímica , Lactente , Recém-Nascido , Sinucleínas , alfa-SinucleínaRESUMO
Somatic hypermutation (SH) in B cells undergoing T cell-dependent immune responses generates high-affinity antibodies that provide protective immunity. Most current models of SH postulate the introduction of a nick into the DNA and subsequent replication-independent, error-prone short-patch synthesis by one or more DNA polymerases. The Pol kappa (DinB1) gene encodes a specialized mammalian DNA polymerase called DNA polymerase kappa (pol kappa), a member of the recently discovered Y family of DNA polymerases. The mouse PolK gene is expressed at high levels in the seminiferous tubules of the testis and in the adrenal cortex, and at lower levels in most other cells of the body including B lymphocytes. In vitro studies showed that pol kappa can act as an error-prone polymerase, although they failed to ascribe a clear function to this enzyme. The ability of pol kappa to generate mutations when extending primers on undamaged DNA templates identifies this enzyme as a potential candidate for the introduction of nucleotide changes in the immunoglobulin (Ig) genes during the process of SH. Here we show that pol kappa-deficient mice are viable, fertile and able to mount a normal immune response to the antigen (4-hydroxy-3-nitrophenyl)acetyl-chicken gamma-globulin (NP-GC). They also mutate their Ig genes normally. However, pol kappa-deficient embryonic fibroblasts are abnormally sensitive to killing following exposure to ultraviolet (UV) radiation, suggesting a role of pol kappa in translesion DNA synthesis.