Virchows Archiv. B, Cell pathology including molecular pathology最新文献

Recently, the association of Epstein-Barr virus (EBV) with undifferentiated lymphoepithelioma-like carcinoma and adenocarcinoma of the stomach has been described. In this study of 55 primary gastric lymphomas, most of them belonging to the group of MALT lymphomas, the question of possible EBV involvement has been addressed using in-situ hybridization (ISH) and blot techniques. EBV DNA and/or DNA sequences were found in only two of 24 centroblastic and B-immunoblastic lymphomas and in one anaplastic large cell lymphoma of null cell phenotype. In a further centroblastic lymphoma, a few positive nontumorous (bystander) cells were identified by ISH. By means of ISH, no positive signals could be detected in the preserved overlying mucosa nor in regenerating epithelium adjacent to lymphoma-induced ulcerations.

Transforming growth factor-beta (TGF beta 1) and tumor necrosis factor alpha (TNF alpha) stimulate the transdifferentiation of fat-storing cells (FSC) in the rat liver into highly active and "synthetic" myofibroblast-like cells (MFBIC). This activation has been documented by differential-interference contrast and light microscopy using morphologic criteria (a reduction in the number and size of fat droplets, cell flattening and the development of long cytoplasmic extensions), by the loss of retinyl-palmitate (measured by HPLC) and by the enhanced expression of iso-alpha smooth muscle actin (demonstrated by immunofluorescence microscopy). Furthermore, while cell growth measured by the cell count and DNA content is slightly inhibited by TGF beta 1 (0.81 of the control), the combination of TGF beta 1 with TNF alpha stimulates cell proliferation to 1.44 times of the control. In addition the combination of TGF beta and TNF alpha potentiated the stimulatory effect on fibronectin synthesis (TGF beta alone: 1.4 times control; TNF alpha alone: 2.2 times control; TGF beta plus TNF alpha: 4.7 times control). The total protein synthesis was not altered by TGF beta or TNF alpha. In summary the results obtained identify TGF beta and TNF alpha as mediators stimulating key events in liver fibrogenesis (i.e. FSC proliferation, FSC transdifferentiation into MFBIC, and fibronectin synthesis).

In this study we compared the functions of normal peritoneal macrophages with those from methimazole-induced hypothyroid C57BL/6 mice. Methimazole (MMI) suppressed the expression of the tumor necrosis factor (TNF) gene in peritoneal macrophages (MAM) at both transcriptional and translational levels. The kinetics of TNF synthesis by MAM following in vivo and in vitro lipopolysaccharide (LPS) challenge were different, but both treatments resulted in significant decreases (P < 0.05) in TNF mRNA and protein after 60 min. Similarly, the production of reactive nitrogen and oxygen intermediates by MAM were significantly (P < 0.05) lower compared with control macrophages (CAM). In addition, the serum TNF protein was significantly lower (P < 0.05) in MMI-treated mice following intravenous LPS challenge for 90 min. These data suggested that peritoneal macrophages were inactivated in MMI-induced hypothyroid mice.

The alterations of hepatic peroxisomes and their enzymes during aging were investigated in male rats. Peroxisomes in the livers of young (2 months) and old (39 months) male Wistar rats were analyzed by morphometry and quantitative immunocytochemistry, as well as by immunoblotting of highly purified peroxisomal fractions. Immunoblots showed that catalase and acyl-CoA oxidase were decreased in peroxisomes of old animals but the trifunctional enzyme, thiolase, and urate oxidase were increased. The morphometrical analysis revealed a heterogeneous distribution of peroxisomes in the liver lobule of the old animals, with a significant elevation of peroxisomal volume density in pericentral over periportal hepatocytes, in contrast to the uniform pattern in the young rats. Furthermore, age-related lobular gradients were also observed by quantitative immunocytochemistry in the peroxisomal concentrations of trifunctional enzyme (central > portal) and, inversely, for catalase (portal > central). Whereas acyl-CoA oxidase was diminished across the liver lobule, the enzyme 3-ketoacyl-CoA thiolase was elevated. These observations show that peroxisomes are significantly altered in aged animals and suggest that these alterations may contribute to the disturbance of lipid metabolism in aged animals. Moreover, the diminution in catalase and the elevation of urate oxidase could contribute to the oxidative stress which is considered to be of fundamental importance in the aging process.

Four well differentiated gastric adenocarcinoma cell lines from German patients have been established from primary tumors (St 23132, St 3051) and lymph node metastases (St 2474, St 2957). The tumor cells were isolated by enzymatic or mechanical treatment. All four lines grew as solid tumors in nude mice and formed colonies in soft agar. The doubling time of the cells in culture was 25-32 h. Further characteristics of the lines were a considerable chromosomal aneuploidy, (the chromosomal numbers varying from 30-109 with many numerical and structural abnormalities), a stable keratin expression (Ck 8, 18, 19), the expression and secretion of CEA and CA-19-9 and the overexpression of c-myc. The four stomach cancer cell lines described here are not only a useful addition to the small number of existing lines, but also represent ideal tools for studying tumorigenicity of human stomach cancers in vitro and in vivo.

The correlation between the silver-stained nucleolar organizer region associated proteins (Ag-NORs) and the growth rate suppression (GRS) of ten established breast cancer cell lines which were treated with 4-hydroxy-tamoxifen (OHT) and interferon-gamma (g-IFN), respectively, was investigated by means of automated image analysis. Previous studies have shown a statistically significant relationship between the Ag-NOR quantity and the population doubling time (PDT) of these cell clones. The results of the present study showed a highly significant correlation between the GRS and the Ag-NOR quantity in estrogen receptor (ER) positive tumour cell lines after OHT treatment (P < 0.001) whereas no strict correlation of these parameters could be demonstrated after g-IFN treatment in both ER positive and negative cell lines. Our results suggest a different behaviour of NOR-proteins in breast cancer cell lines if treated either with g-IFN or OHT, probably reflecting the different mechanism of cell suppression mediated by OHT and g-IFN. It is concluded that quantitative assessment of Ag-NORs is not as suitable for the determination of the GRS as it is for the determination of cell duplication rates obtained on untreated tumour cell lines.

A new human epithelioid sarcoma cell line (ES020488) was established from a cutaneous metastasis in 26-year-old man, and was morphologically characterized in vitro and in vivo by comparison with the original tumor. The ES020488 cells showed a male karyotype ranging from 39 to 83 chromosomes, with various abnormalities but no specific pattern. The cells were round, polygonal or spindle-shaped with abundant cytoplasm and round nuclei containing prominent nucleoli; they proliferated in a sheet-like pattern. Tumors transplanted into nude mice revealed essentially the same features as the original tumor. Both in vitro and in vivo, the cells immunohistochemically expressed vimentin, cytokeratin, and EMA, but not desmin and S-100 protein. Ultrastructural study revealed irregular or round nuclei containing abundant euchromatin and prominent nucleoli, many intermediate filaments running irregularly or around the nucleus, and a number of filopodia-like processes. ES020488 cells were thus proven to retain and exhibit the unique morphological characteristics of an epithelioid sarcoma both in vitro and in vivo. These cells are possibly derived from synovioblastic mesenchyme.

Hepatocellular carcinoma (HCC) is one of the most frequent malignancies in humans and in most cases a consequence of chronic infection of the liver by hepatotropic viruses (Hepatitis B Virus (HBV) and possibly Hepatitis C Virus (HCV)). Formation of HCC results from a stepwise process involving different preneoplastic lesions that reflect multiple genetic events, like protooncogene activation, tumor suppressor gene inactivation, and growth factor over- or reexpression. Recent investigations have gained new insights into how these factors are activated and may interact. In addition, improved knowledge of the molecular biology of HBV has led to better understanding of its pleiotropic effects on induction and progression in hepatocarcinogenesis.

In certain mammals, the lung plays an important role in removing blood-borne foreign bodies by means of the numerous macrophages disposed in pulmonary capillaries. The present ultrastructural study demonstrates that in the guinea pig, the lung also plays a significant role in this respect, but that in this species, foreign body elimination takes place by another, hitherto undescribed process. In the guinea pig, the pulmonary capillaries are characterized by numerous neutrophils that adhere to endothelial cells even under normal conditions. At 30 min after intravenous injection of glutaraldehyde-fixed erythrocytes, large numbers of these foreign bodies were found to be ingested by these neutrophils. At 6 h after injection, the erythrocyte-carrying neutrophils had disappeared from the vascular lumen, but endothelial cells had begun vigorously to engulf the fixed erythrocytes by extending membranous processes which completely enwrapped them. Since endothelial cells lack lysosomes, there was no morphologic evidence of erythrocyte digestion within their cytoplasm. It is evident that the erythrocytes then passed through the endothelium, since by 48 h after injection, most of them were incorporated and digested by macrophages proliferating in the alveolar interstitium. The increase in macrophages was confirmed by acid phosphatase histochemistry. These observations indicate that in the guinea pig, the lung plays an important role in clearing blood-borne foreign bodies by the sequential involvement of intracapillary neutrophils, capillary endothelial cells and interstitial macrophages.

Heparins blunt the development of glomerulosclerosis in several disease models in the rat and this protective effect may be related to suppression of glomerular cell proliferation. In this study the direct effect of heparins on another key event in glomerulosclerosis, extracellular matrix (ECM) deposition, was examined. Standard heparin (hep) and non-anticoagulant N-desulfated acetylated heparin (DSA-hep) significantly reduced the fibronectin content in the conditioned media of subconfluent, confluent, and supraconfluent rat glomerular mesangial cells (MCs) in culture, as assessed by a sandwich ELISA technique. Both heparins significantly increased the amount of cell-associated fibronectin in sparse and subconfluent MCs. DSA-hep, but not hep, increased the fibronectin content of ECM formed by confluent and supraconfluent MCs. Using 3H-proline pulse-labeling, Hep and DSA-hep were found to significantly decrease cell-associated collagen in subconfluent but not in confluent MCs. No effects were seen on newly synthesized collagen secreted into the culture medium. Neither hep nor DSA-hep affected total protein synthesis, studied by metabolic labeling with 35S-methionine. High resolution 2-D electrophoresis (molecular weight range, 120 to 10 Kd; isoelectric interval, 5.0 to 7.0) revealed one particular intracellular protein (molecular weight 54 Kd, pI 5.91) which was consistently overexpressed in hep. Both heparins affected an identical set of another 19 different intracellular MC proteins (over-/underexpression or shift to higher molecular weights). In conclusion, the present data demonstrate the profound direct metabolic effects of hep and DSA-hep.(ABSTRACT TRUNCATED AT 250 WORDS)