Search results for "Pathology and Forensic Medicine"

Mitochondrial and chromosomal DNA alterations in human chromophobe renal cell carcinomas

1992

Renal cell tumours are characterized by the loss of chromosome 3p and trisomy of 5q segments (common, non-papillary renal cell carcinoma), or by trisomy of chromosomes 7 and 17 and loss of the Y chromosome (papillary renal cell carcinoma), or by random karyotype changes and mitochondrial DNA alterations (renal oncocytoma). We have studied by means of RFLP analysis the genomic and mitochondrial DNA in 11 chromophobe renal cell carcinomas, which have a unique morphology among kidney cancers. We found a loss of the constitutional heterozygosity at chromosomal regions 3p, 5q, 17p, and 17q, a combination of allelic losses that has not been found in other types of renal cell tumours. Three of the…

Assessment of proliferative activity in breast cancer: MIB-1 immunohistochemistry versus mitotic figure count.

1999

Abstract The proliferative activity is one of the most important single prognostic parameters in breast cancer diagnosis and the time-honored measure of proliferative activity, the mitotic figure count, is an integral component of most combined prognostic scores. The detection of the cell cycle-specific antigens Ki-67, and the development of anti-Ki-67 antibodies, including the paraffin-reactive antibody MIB-1, have established immunohistochemical detection of cell cycle-specific antigens as a measure of proliferative activity in breast cancer diagnosis. The current study was performed to correlate mitotic figure counts with the proliferative activity as assessed by MIB-1 immunohistochemist…

Identification of a Novel BRCA1 Alteration in Recurrent Melanocytoma Resulting in Increased Proliferation

2020

Abstract Primary meningeal melanocytomas are rare tumors of the central nervous system. Although they are considered benign neoplasms, some reports describe recurrent rates up to 45%. Little is known about their genetic and epigenetic landscape because of their infrequency. Even less has been described about markers with prognostic value. Here we describe a patient who developed a primary meningeal melanocytoma, suffered 3 recurrences in a period of 6 years and died of the tumor. The genetic and epigenetic changes explored confirmed GNAQ mutation as an initiating event. We found an epigenetic alteration of GSTP1, a feature that has recently been described in meningiomas, from the beginning …

Mitotic figure counts are significantly overestimated in resection specimens of invasive breast carcinomas.

2013

Several authors have demonstrated an increased number of mitotic figures in breast cancer resection specimen when compared with biopsy material. This has been ascribed to a sampling artifact where biopsies are (i) either too small to allow formal mitotic figure counting or (ii) not necessarily taken form the proliferating tumor periphery. Herein, we propose a different explanation for this phenomenon. Biopsy and resection material of 52 invasive ductal carcinomas was studied. We counted mitotic figures in 10 representative high power fields and quantified MIB-1 immunohistochemistry by visual estimation, counting and image analysis. We found that mitotic figures were elevated by more than th…

Myopathology of non-infectious inflammatory myopathies - the current status.

2007

Besides the classical inflammatory myopathies (IM), dermatomyositis (DM), polymyositis, and inclusion body myositis, the much larger spectrum of IM includes focal and nodular myositis, granulomatous myositis, macrophagic myofasciitis, graft vs. host myositis, eosinophilic myositis, and other immune-associated conditions, some of them only recently described. In addition, paraneoplastic, statin-induced and critical illness myopathies have been considered immune-associated IM. Infectious, i.e., bacterial, viral, and parasitic IM are much less frequent in the northern hemisphere. In IM, muscle biopsy is an essential diagnostic procedure to initiate therapy. The myopathological spectrum encompa…

Metastasizing anaplastic ependymoma in an adult. Chromosomal imbalances, metabolic and gene expression profiles

2009

Absence of p53 gene mutations in hepatocarcinomas from a Mediterranean area of Spain

1999

The incidence of p53 gene abnormalities in human hepatocellular carcinoma (HCC) varies in different geographical areas, being higher in regions where hepatitis virus infection and dietary exposure to aflatoxin B1 are the most common aetiological agents. These mutations are less frequently encountered in Europe, although some studies have reported p53 protein overexpression in up to 45% of cases analysed. We have analysed 129 tumour samples of primary malignant hepatic neoplasms recovered from paraffin blocks processed in two pathology laboratories in a Mediterranean area of Spain (Valencia and Gerona). Among 14 cases in which p53 immunohistochemistry expression proved positive, 5 stained in…

Dystrophin and metalloproteinase 9 in myocardial ischemia: A post-mortem immunohistochemical study

2021

The presented study evaluated the expression of dystrophin and MMP-9 in cases of sudden cardiac death (SCD) due to coronary atherosclerotic disease (CAD) in order to analyze the characteristics and the chronology of their expression, providing evidence on the possible role in post-mortem diagnosis of myocardial ischemia. The expression of these proteins was also compared to C5b-9 complex and fibronectin expression to evaluate any differences. Two groups of CAD-related SCD, respectively group 1 with gross and/or histological evidence and group 2 with no specific histological signs of myocardial ischemia, were used. A third group formed by cases of acute mechanical asphyxiation was used as a …

The disruption of myofibre structures in skeletal muscle after forced lengthening contractions

1998

Specific antibodies against structural proteins (actin, desmin, dystrophin, fibronectin) of muscle fibres were used to study the effect of forced lengthening contractions on muscle microarchitecture. Tibialis anterior (TA) muscle of male Wistar rats were subjected to 240 forced lengthening contractions. At consecutive time points (0, and 6 h, 2, 4, and 7 days) after stimulation, the TA muscle was excised for biochemical and histological assays. β-Glucuronidase activity, a quantitative indicator of muscle damage, showed increased values 2–7 days after the lengthening, peaking on day 4 (11.7-fold increase). A typical course of histopathological changes (myofibre swelling, necrosis and regener…

Abnormal accumulation of autophagic vesicles correlates with axonal and synaptic pathology in young Alzheimer's mice hippocampus

2012

Dystrophic neurites associated with amyloid plaques precede neuronal death and manifest early in Alzheimer's disease (AD). In this work we have characterized the plaque-associated neuritic pathology in the hippocampus of young (4- to 6-month-old) PS1(M146L)/APP(751SL) mice model, as the initial degenerative process underlying functional disturbance prior to neuronal loss. Neuritic plaques accounted for almost all fibrillar deposits and an axonal origin of the dystrophies was demonstrated. The early induction of autophagy pathology was evidenced by increased protein levels of the autophagosome marker LC3 that was localized in the axonal dystrophies, and by electron microscopic identification…