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Necrotic Foci (necrotic + focus)
Selected AbstractsHematopoietic mobilization in mice increases the presence of bone marrow,derived hepatocytes via in vivo cell fusion,HEPATOLOGY, Issue 1 2006Oscar Quintana-Bustamante The mechanisms for in vivo production of bone marrow,derived hepatocytes (BMDHs) remain largely unclear. We investigated whether granulocyte colony,stimulating factor (G-CSF),mediated mobilization of hematopoietic cells increases the phenomenon. Recurrent liver injury in mice expressing green fluorescent protein (EGFP) in all hematopoietic-derived cells was produced by 3 months of carbon tetrachloride (CCL4) injections. Histologically, there were necrotic foci with histiocyte-rich infiltrates, but little oval cell proliferation. Subsequently, some animals were mobilized with G-CSF for 1, 2, or 3 weeks. Animals were sacrificed 1 month after growth factor treatment. BMDH percentages were lower than previously reported, though G-CSF mobilization significantly augmented BMDH production in injured livers. BMDHs originating from in vivo fusion were evaluated by transplanting female EGFP+ cells into male mice. Binucleated, EGFP+ hepatocytes with one Y chromosome, indicating fusion, were identified. In conclusion, (1) mobilization of hematopoietic cells increases BMDH production and (2) as with the FAH-null model, the first model demonstrating hematopoietic/hepatocyte fusion, recurring CCl4 -induced injury has macrophage-rich infiltrates, a blunted oval cell response, and a predominantly in vivo fusion process for circulating cell engraftment into the liver. These findings open the possibility of using hematopoietic growth factors to treat nonhematopoietic degenerative diseases. (HEPATOLOGY 2006;43:108,116.) [source] Methotrexate-related leukoencephalopathy without radiation therapy: Distribution of brain lesions and pathological heterogeneity on two autopsy casesNEUROPATHOLOGY, Issue 2 2009Jun Matsubayashi This report concerns two rare autopsy cases of methotrexate (MTX)-related leukoencephalopathy without radiation therapy. In the first case, there were widespread necrotic foci with prominent spheroids, that is, disseminated necrotizing leukoencephalopathy (DNL), mainly in the cerebral white matter. In contrast, in the second case, there were widespread demyelinated foci without significant axonal changes, which we would like to name disseminated demyelinating leukoencephalopathy (DDL), mainly in the cerebral white matter. We emphasize that the pathology of pure MTX-related leukoencephalopathy is not uniform, and may show at least two kinds of histologic change. Furthermore, both cases did not develop significant vascular changes, which are usually induced by radiation therapy. The distribution of the lesions in two cases was examined by large specimens, including hemisphere specimens. The distribution of the lesions in the brain of our cases was also different. In the first case, the DNL lesions were predominantly distributed in the frontal and temporal lobes. In the second case, the DDL lesions were prominently localized in the occipital lobe. To our knowledge, this is the first report describing not only the pathological findings of MTX-related leukoencephalopathy without irradiation but also the precise distributions of the lesions. [source] Autopsy case of neuro-Behçet's disease with multifocal neutrophilic perivascular inflammationNEUROPATHOLOGY, Issue 6 2006Yoshifumi Arai We report here an autopsy case of neuro-Behçet's disease. The patient was a 28-year-old man, who developed a slight fever, right uveitis, and right sensory neural hearing loss at the age of 25. These symptoms relapsed repeatedly despite treatment. Eventually he was admitted to hospital because of progressing neurological deficits such as pyramidal symptoms, somatic sensorial and autonomic disorders, and bulbar palsy. The patient's condition deteriorated and he died of heart failure. Total clinical course was about three years. In postmortem examination, various-sized necrotic foci, often accompanied by gliosis and foamy macrophage infiltration, were scattered in the diencephalic region and brain stem. Meningitis was observed on the ventral side of the brain stem as well as inferior cerebral surface. Non-bacterial or non-fungal acute perivascular inflammatory foci were also present in the brain stem and cerebellar parenchyma. These histopathological findings suggest that a destructive multifocal neutrophilic inflammation might have caused the neurological deficits. Perivascular inflammation might be important to understanding the pathogenesis of neuro-Behçet's disease. [source] Malignant peripheral nerve sheath tumor arising in benign ancient schwannoma: A case report with an immunohistochemical studyPATHOLOGY INTERNATIONAL, Issue 2 2000Yoshiki Mikami A rare example of malignant transformation in an ancient schwannoma arisng in the right side of the neck of a 51-year-old man without any clinical manifestations suggesting neurofibromatosis is described. The tumor, approximately 4 cm at its largest dimension, was well circumscribed and had a direct connection with the sympathetic nerve. Microscopically, the central portion of the tumor showed features of ancient schwannoma characterized by extensive hyalinization with cystic degeneration, scattered spindle cells with hyperchromatic and tapered nuclei, and some symplastic changes. However, predominantly in the outer portion, a proliferation of spindle-shaped cells with enlarged nuclei was present. The nuclei of these cells showed irregular contours, coarse granular chromatin texture, and conspicuous nucleoli. Mitotic figures and small necrotic foci with scattered apoptotic bodies were also seen. Immunohistochemically, S-100 protein was almost negative in areas consisting of overtly atypical cells where the mitotic index evaluated with MIB-1 antibody was 30.5%. In contrast, S-100-positive bland spindle cells were scattered in an extensively hyalinized area with a labeling index less than 3%. P53 protein was strongly positive in atypical spindle cells. Although it is a very uncommon event, definite nuclear atypia, frequent mitotic figures, and the existence of small necrotic foci should be recognized as indicating a diagnosis of malignant degeneration of benign schwannoma. Immunohistochemistry would be useful as an ancillary technique in such a setting. [source] RESEARCH ARTICLE: Myelin Abnormalities without Oligodendrocyte Loss in Periventricular LeukomalaciaBRAIN PATHOLOGY, Issue 2 2008Saraid S. Billiards Abstract The cellular basis of myelin deficits detected by neuroimaging in long-term survivors of periventricular leukomalacia (PVL) is poorly understood. We tested the hypothesis that oligodendrocyte lineage (OL) cell density is reduced in PVL, thereby contributing to subsequent myelin deficits. Using computer-based methods, we determined OL cell density in sections from 18 PVL and 18 age-adjusted control cases, immunostained with the OL-lineage marker Olig2. Myelination was assessed with myelin basic protein (MBP) immunostaining. We found no significant difference between PVL and control cases in Olig2 cell density in the periventricular or intragyral white matter. We did find, however, a significant increase in Olig2 cell density at the necrotic foci, compared with distant areas. Although no significant difference was found in the degree of MBP immunostaining, we observed qualitative abnormalities of MBP immunostaining in both the diffuse and necrotic components of PVL. Abnormal MBP immunostaining in PVL despite preserved Olig2 cell density may be secondary to arrested OL maturation, damage to OL processes, and/or impaired axonal-OL signaling. OL migration toward the "core" of injury may occur to replenish OL cell number. This study provides new insight into the cellular basis of the myelin deficits observed in survivors of PVL. [source] Some new aspects of the pathology, pathogenesis, and aetiology of disseminated lung lesions in slaughter pigsAPMIS, Issue 5 2003CAMILLA H. LILJEGREN From 40 pigs rejected for human consumption at slaughter due to an apparent presence of pyemic lung lesions (defined as disseminated processes containing pus and/or necrotic material), the lungs, spleen, liver, and kidneys were subjected to an extended macroscopic examination. Several lung lesions were sampled from each animal for histological and bacteriological examination. Samples from the kidneys and spleens were also subjected to bacteriological examination. At gross level, four groups of lung lesions were identified: 1) disseminated foci with contents of pus and/or necrotic material (n=26); 2) disseminated or multifocally located ecchymoses with a central area of fibroplasia (n=9); 3) non-pneumonic lesions, i.e., disseminated areas of atelectasis (n=1) or haemorrhagic areas developing due to the process of slaughter (n=1); and 4) suppurative lesions without a disseminated distribution pattern (n=3). Histologically, the disseminated suppurative/necrotic foci were identified as: A) abscesses (n=10); B) necrotic lesions (n=6); and C) ectatic or ectatic-like bronchioles with contents of pus and necrotic material (n=10). The macroscopic observation of disseminated centres of fibroplasia with peripheral ecchymoses (n=9) was confirmed histopathologically. The livers of five pigs contained multiple areas of chronic interstitial fibrosis related to migration of Ascaris suum larvae ("milk spotted liver"). Such hepatic lesions were significantly (p<0.01) related to the simultaneous occurrence of disseminated pulmonary ecchymoses with a central area of fibroplasia. Generally, all lung lesions of each individual animal contained identical monocultures of bacteria following this pattern: Staphylococcus aureus (abscesses); Actinomyces hyovaginalis (necroses); S. aureus, A. hyovaginalis, and Arcanobacterium pyogenes (ectatic and ectatic-like bronchioles). Areas with fibrosis were sterile or contained bacteria considered to be a result of contamination. Apart from one kidney, from which S. aureus was cultured, all other organs were sterile. It is concluded that difficulties exist in differentiating pulmonary pyemic lesions from non-pyemic lesions at the gross level. Thus, it was not possible to distinguish between abscesses/necroses and ectatic bronchioles, the pathogenesis of the latter being uncertain. However, the chronic non-pyemic lesions related to the migration of A. suum larvae should be identified by the absence of pus/necrosis. S. aureus was predominantly isolated from abscesses, whereas, and most surprisingly, A. hyovaginalis was the dominant bacterium isolated from the pulmonary necroses. [source] | ||||||||||