Electron microscopic radioautographic study on nucleic acid synthesis in amitotic hepatocytes of the aging mouse

Twenty groups of aging mice, each consisting of three individuals from fetal day 19 to postnatal month 24, were injected with either ³H-thymidine or ³H-uridine. The mice were killed 1h and the livers processed for light and electron microscopic radioautography. On radioautograms obtained from each animal, amitotic nuclear divisions and resulting binucleate hepatocytes were detected and compared to mononucleate hepatocytes. From the results, it was demonstrated that only a few hepatocytes showing amitotic nuclear division were found labeled with the two precursors demonstrating DNA and RNA synthesis. However, there were very few silver grains showing incorporation of labeled precursors in respective amitotic cells. It was clarified that the amitotic cells did not synthesize such macromolecules as mononucleate hepatocytes did. On the other hand, the binucleate cells were found more often than the amitotic cells. DNA synthesis of binucleate hepatocyte nuclei was observed at the perinatal stage but disappeared at the adult stage. RNA syntheses in karyoplasm and cytoplasm in both mononucleate and binucleate cells significantly increased from the perinatal stage, reaching the maxima at the adult stage, then significantly decreased to the senescent stage. Grain counts revealed that RNA was synthesized significantly more in binucleate cells than in mononucleate cells at the respective aging stages.     

Phenotype Analysis and Quantification of Proliferating Cells in the Cortical Gray Matter of the Adult Rat

In intact adult mammalian brains, there are two neurogenic regions: the subependymal zone and the subgranular layer of the hippocampus. Even outside these regions, small numbers of proliferating precursors do exist. Many studies suggest that the majority of these are oligodendrocyte precursors that express NG2, a chondroitin sulfate proteoglycan, and most of the residual proliferating cells seem to be endothelial cells. However, it is still unclear whether NG2-immunonegative proliferating precursors are present, because previous studies have neglected their possible existence. In this study, we systematically analyzed the phenotypes of the proliferating cells in the intact adult rat cortical gray matter. We improved our techniques and carefully characterized the proliferating cells, because there were several problems with identifying and quantifying the proliferating cells: the detection of NG2-expressing cells was dependent on the fixation condition; there were residual proliferating leukocytes in the blood vessels; and two anti-NG2 antibodies gave rise to different staining patterns. Moreover, we used two methods, BrdU and Ki67 immunostaining, to quantify the proliferating cells. Our results strongly suggest that in the intact adult cerebral cortical gray matter, there were only two types of proliferating cells: the majority were NG2-expressing cells, including pericytes, and the rest were endothelial cells.     

New serological assay for detection of putative Helicobacter pylori virulence factors

We evaluated a new immunoblot assay (Helicoblot 2.1) for Helicobacter pylori infection and CagA and VacA status by using serum samples from 222 patients. The test accurately detected H. pylori infection and VacA status, but improvements in the interpretation criteria are required before it can be recommended for determination of CagA status.     

Neural fibrolipoma of the superficial peroneal nerve in the ankle: a case report with immunohistochemical analysis

This report presents a case of neural fibrolipoma arising from the superficial peroneal nerve in the ankle. A 28-year-old woman was referred with a soft tissue mass in the anterior aspect of the right ankle, which had been gradually enlarging for the past 10 years. Magnetic resonance imaging showed a mass lesion, measuring approximately 8 x 3 x 2 cm, with high to partially low signal intensity on both T1- and T2-weighted images. A band of low signal intensity within the lesion, which is indicative of coexistence with the tumor and the superficial peroneal nerve, could be detected on both T1- and T2-weighted images. The patient underwent an excisional biopsy. The specimen microscopically consisted of nerve bundles and fibro-fatty proliferation with abundant collagen fibers. Immunoreactivity for CD34 antigen antibody was detected in fibrous spindle cells. This is the first report to present an immunohistochemical profile of neural fibrolipoma. Neural fibrolipoma should be considered as a differential diagnosis when a lipomatous lesion is encountered in the foot or ankle as well as in the upper extremities.     

Preferential expression of T(h)2-type chemokine and its receptor in atopic dermatitis

Lesional skin of patients with atopic dermatitis (AD) is histologically characterized by hypertrophy of the skin, and the infiltration of a large number of eosinophils and T cells into the dermis. Recent studies have indicated that Th2 cells play a crucial role in the pathogenesis of AD skin. Chemokines and their receptors are implicated in the development of symptoms of various skin diseases such as AD and psoriasis vulgaris (psoriasis). We have examined the in situ expression of a typical Th2-type chemokine, thymus- and activation-regulated chemokine (TARC), and its receptor (CCR4) using immunohistochemical techniques. TARC was found to be highly expressed in the basal epidermis of the lesional skin of AD patients and only slightly in the non-lesional skin. On the other hand, no positive cells were seen in the lesional skin of psoriasis. Consistently, CCR4+ cells were present predominantly in the lesional skin of AD patients, but not in the non-lesional skin. In contrast, in the lesional skin of psoriasis patients, cells positive for CCR5, which is expressed on Th1 cells, were abundantly present. Interestingly, psoralen plus ultraviolet A therapy reduced the number of CCR4+ cells in the AD skin lesions. These results suggest that Th2-type cytokines such as TARC are involved in the pathogenesis of skin lesions in AD patients through the preferential recruitment of Th2 cells.     

Scrape and fine-needle aspiration cytology of extraskeletal osteosarcoma

Extraskeletal osteosarcoma is a rare malignant soft tissue tumor whose cytologic findings are infrequently reported. We describe scrape and fine-needle aspiration biopsy (FNAB) cytology findings of an extraskeletal osteosarcoma in the right shoulder of a 24-yr-old man. Initial computed tomography revealed multiple ossification foci within the lesion. After excision of the primary tumor, the tumor recurred 13 months later. Scrape smears of both the primary tumor and FNAB smears of the recurrent tumor revealed moderate cellularity, cell clusters, and individual cells, closely associated with dense, homogeneous, acellular matrix material. The cells had elongated, oval, or partially bizarre-shaped nuclei with a coarse chromatin pattern and prominent nucleoli. The scrape smears contained large fragments of matrix material consistent with osteoid.     

Expression of tumor necrosis factor ligand superfamily costimulatory molecules CD27L, CD30L, OX40L and 4-1BBL in the heart of patients with acute myocarditis and dilated cardiomyopathy.

BACKGROUND: T-cell-mediated myocardial damage is known to be involved in acute myocarditis and dilated cardiomyopathy. Recently, we found that tumor necrosis factor (TNF) ligand superfamily costimulatory molecules, especially 4-1BBL, played an important role in the myocardial damage of murine acute viral myocarditis. METHODS AND RESULTS: To investigate the roles for CD27L, CD30L, OX40L and 4-1BBL, which belong to TNF ligand superfamily, in the development of acute myocarditis and dilated cardiomyopathy, we analyzed the expression of these antigens in the myocardial tissues of patients with acute myocarditis and dilated cardiomyopathy. We also examined expression of the receptors for these molecules, CD27, CD30, OX40 and 4-1BB, which belong to TNF receptor superfamily, on the infiltrating cells. Strong expression of CD27L, CD30L and 4-1BBL and weak to moderate expression of OX40L was found in the cardiac myocytes of patients with acute myocarditis. Moderate expression of CD27L, CD30L and 4-1BBL and weak expression of OX40L was found on the cardiac myocytes of patients with dilated cardiomyopathy. Most of the infiltrating cells expressed CD27, CD30 and 4-1BB and a part of the infiltrating cells expressed OX40. CONCLUSIONS: Our findings suggest that expression of TNF ligand superfamily costimulatory molecules on cardiac myocytes may play a role in the cell-mediated myocardial damage in patients with acute myocarditis and dilated cardiomyopathy as in murine viral myocarditis.     

Uninephrectomy induces progressive glomerulosclerosis and apoptosis in anti-Thy1 glomerulonephritis

Administration of the anti-Thy1 antibody in rats induces reversible glomerulonephritis resembling human mesangiolytic and mesangioproliferative diseases. The purpose of the present study was to design a model of irreversible glomerulosclerosis, using the anti-Thy1 antibody injection after uninephrectomy, and examine it, focusing on apoptosis in the process of progressive sclerotic changes. Wistar rats were divided into three groups: one-kidney groups (group I and III) and a two-kidney group (group II). All groups were injected with the anti-Thy1 antibody (OX-7) at day 0, and group I and III were uninephrectomized at day -6. Only group III rats were given a half dose of OX-7 as compared with group I and II. Rats were killed for histological examinations at days 7, 14 and 30. In group I, progressive glomerular lesions, such as glomerular adhesion to Bowman's capsule, crescent formation, and collapse of capillary tufts were observed at days 14 and 30. No significant differences were observed in the pathological findings between group I and III. There was a significantly higher number of glomerular terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling-positive cells in group I as compared to group II at days 7 and 14. Moreover, the glomerular expression of transforming growth factor-beta, heparan sulfate proteoglycan and chondroitin sulfate proteoglycan significantly increased in group I as compared to group II at days 7 and 14. Progressive glomerulosclerosis can be induced in the rat by a single injection of the anti-Thy1 antibody after unilateral nephrectomy. It is suggested that apoptosis and extracellular matrix accumulation play an important role in the development of glomerulosclerosis.