Hypersegmentation of inflammatory cells in Langerhans cell granulomatosis

Langerhans cell granulomatosis (LCG) is characterized by a mixture of Langerhans cells and eosinophils in varying proportions. The characteristic morphology of Langerhans cells have already been described in many articles, but little attention has been paid to inflammatory cells. We examined six cases of Langerhans cell granulomatosis, which had originally been diagnosed as eosinophilic granuloma. Inflammatory cells present in LCG showed hypersegmentation. Twenty percent to 70% of eosinophils had three or more segmented nuclei, and 10-25% of neutrophils had five or more segmented nuclei. Such findings have never been described, and we believe hypersegmentation to be a feature of LCG. Furthermore, we emphasize that eosinophils in LCG mimic neutrophils in ethanol-fixed preparations, and thus may be a pitfall in making a diagnosis in cytology and intraoperative consultation.     

Epstein-Barr virus-associated post-transplant primary smooth muscle tumor of the liver: Report of an autopsy case

Epstein-Barr (EB) virus-associated primary smooth muscle tumors have been reported in immunosuppressed young patients with acquired immunodeficiency syndrome (AIDS) and young people who have undergone liver transplantation. An autopsy case of EB virus-associated smooth muscle cell tumor in a 21 year old female who received immunosuppres-sive therapy following renal transplantation Is repotted. Multiple tumor nodules were present in the liver, but no primary lesion was found in any other organ. Histologically, the nodules were composed of spindle cells, positive for α-smooth muscle action, which were arranged in fascicles and closely associated with vascular channels, thereby suggesting a vascular smooth muscle cell origin. EB virus infection of the tumor cells was clearly demonstrated by in situ hybridization with an EB virus-encoded RNA 1 (EBER-1) probe. The present case illustrates that EB virus infection may play some role in the development of smooth muscle tumors not only in immunocompromised young patients with liver allo-grafts, but also in those with renal allografts.     

Serotonin 2A receptor gene polymorphism and personality traits: no evidence for significant association

A number of studies have observed associations between the serotonin 2A (5-HT2A) receptor and mental disorders. Here, we investigated correlations between polymorphisms (-1438G/A and 102T/C) of the 5-HT2A gene and personality traits in healthy Japanese volunteers (n = 239). The personality traits were evaluated using the Revised NEO Personality Inventory (NEO PI-R). The -1438G/A and 102T/C were in complete linkage disequilibrium. There was a tendency for associations between the genotype and the scores for Agreeableness, Conscientiousness and Neuroticism of the NEO PI-R (P = 0.028, 0.039 and 0.062, respectively; analysis of variance, uncorrected for multiple testing). Subjects with the A/A of -1438G/A (or T/T of 102T/C) appeared to be lower in Neuroticism and higher in Conscientiousness than the rest of the subjects. However, the results were statistically non-significant after Bonferroni's correction for multiple testing of the five scales of the NEO PI-R. Thus, the present study provided no evidence for statistically significant associations between the 5-HT2A polymorphisms and the personality traits.     

Systemic administration of rIL-12 induces complete tumor regression and protective immunity: response is correlated with a striking reversal of suppressed IFN-{gamma} production by anti-tumor T cells

Unfractionated spleen cells taken from tumor-bearing mice 2weeks after tumor implantation contained tumor-primed T cellswhich produced cytokines including IL-2 and IFN- when culturedin vitro. With progressive tumor growth this initial lymphokine-producingcapacity decreased. Here, we investigated the ability of IL-12to (I) restore suppressed IFN- production, (II) cause tumorregression and (II) induce anti-tumor protective immunity. Additionof rIL-12 to spleen cell cultures from 4- to 10-week-old tumor-bearingmice resulted in a striking enhancement in the production ofIFN- compared with cultures of these cells in the absence ofrIL-12 or of normal spleen cells in the presence of rIL-12.Five I.p. injections of rIL-12 into mice bearing s.c. tumorsinduced complete tumor regression. This was found when rIL-12was given at early (1–2 weeks), intermediate (4–5weeks) or even late (7 weeks) stages of tumor growth. Furthermore,IL-12-treated mice which rejected the primary tumor exhibitedcomplete resistance to a rechallenge with the same tumor butdid not reject a second syngenetic tumor. Immunohistochemicalanalyses following IL-12 treatment revealed that CD4⁺ and CD8⁺T cells infiltrate the tumor. More importantly, IFN- mRNA expressionwas observed in fresh tumor masses from tumor-bearing mice receivingIL-12 treatment The importance of IFN- was further demonstratedby the observation that the systemic administration of anti-IFN-mAb prior to IL-12 treatment completely abrogated the anti-tumoreffect of IL-12. Thus, these results indicate that administrationof modest levels of rIL-12 to tumor-bearing mice results intumor regression through mechanisms involving reversal of suppressedIFN- production by anti-tumor T cells and the establishmentof a tumor-specific protective immune response.     

The assessment of cell proliferation during 9,10-dimethyl-1,2-benzanthracene-induced hamster tongue carcinogenesis by means of histone H3 mRNA in situ hybridization

The aim of this study was to investigate cell kinetics and ultrastructural changes during carcinogenesis using a hamster 9,10-dimethyl-1,2-benzanthracene (DMBA)-induced tongue cancer model. Five squamous cell carcinomas, five dysplastic epithelia, seven hyperplastic epithelia, and four normal epithelia were obtained from 21 hamster tongues by applying 1.0% acetone solution of DMBA on the left lingual mucosa after scratching with a root canal broach. Ultrastructural examination revealed that the number of microvilli increased, whereas that of desmosomes decreased during carcinogenesis. Cell proliferation was analyzed by means of 5-bromodeoxyuridine (BrdU) immunohistochemistry and in situ hybridization (ISH) for histone H3 mRNA. The BrdU and histone H3 mRNA labeling indices (LIs) were lowest for normal epithelium, higher for hyperplastic and dysplastic epithelia, and highest for squamous cell carcinoma. Cytoplasmic histone H3 mRNA and nuclear BrdU were localized in virtually identical areas of serial sections. The correlation coefficient for the relationship between these two LIs was 0.97 (P 0.001). These results suggest that the assessment of cell proliferation using H3 mRNA ISH will be a useful technique for investigating biological behavior during carcinogenesis.     

A HISTOPATHOLOGICAL STUDY OF DIFFUSE HYPERPLASIA OF GASTRIC ARGYROPHIL CELLS

The present study includes a histopathological and immunohistochemical study of 4 cases of diffuse hyperplasia of gastric argyrophil cells. The mode of proliferation of these cells and the production of hormone by these cells have been documented. The distribution of microacinar nests composed of argyrophil cells was thought to be related to chronic gastritis in which there are atrophy of mucosa and intestinal metaplasia. In the case in which these nests were found only in the corpus ventriculi, there was intestinal metaplasia throughout the stomach. On the other hand, in the case in which these nests appeared only in the pyloric area, atrophy of the mucosa with mild intestinal metaplasia was observed only in the pyloric area. The microacinar nests composed of argyrophil cells were distributed in the deep mucosa at the basal portion of the glands in the area with intestinal metaplasia. Serial sections revealed a sprout composed of argyrophil cells budding from the gland with intestinal metaplastic changes. The sprout buds out from the growth zone of glands with Intestinal metaplasia and then becomes isolated and gives rise to reactive hyperplasia. The peptide hormone contained in these cells differs according to the mucosal environments. Cells containing gastrin were observed in the pyloric area, but not in the corpus ventriculi where there was marked intestinal metaplasia. The cells in this area were assumed to contain other hormones.     

Culturing of skin fibroblasts in a thin PLGA-collagen hybrid mesh

A thin biodegradable hybrid mesh of synthetic poly(DL-lactic-co-glycolic acid) (PLGA) and naturally derived collagen was used for three-dimensional culture of human skin fibroblasts. The hybrid mesh was constructed by forming web-like collagen microsponges in the openings of a PLGA knitted mesh. The behaviors of the fibroblasts on the hybrid mesh and PLGA knitted mesh were compared. The efficiency of cell seeding was much higher and the cells grew more quickly in the hybrid mesh than in the PLGA mesh. The fibroblasts in the PLGA mesh grew from the peripheral PLGA fibers toward the centers of the openings, while those in the hybrid mesh also grew from the collagen microsponges in the openings of the mesh resulting in a more homogenous growth. The proliferated cells and secreted extracellular matrices were more uniformly distributed in the hybrid mesh than in the PLGA mesh. Histological staining of in vitro cultured fibroblast/mesh implants indicated that the fibroblasts were distributed throughout the hybrid mesh and formed a uniform layer of dermal tissue having almost the same thickness as that of the hybrid mesh. However, the tissue formed in the PLGA mesh was thick adjacent to the PLGA fibers and thin in the center of the openings. Fibroblasts cultured in the hybrid mesh were implanted in the back of nude mouse. Dermal tissues were formed after 2 weeks and became epithelialized after 4 weeks. The results indicate that the web-like collagen microsponges formed in the openings of the PLGA knitted mesh increased the efficiency of cell seeding, improved cell distribution, and therefore facilitated rapid formation of dermal tissue having a uniform thickness. PLGA-collagen hybrid mesh may be useful for skin tissue engineering.     

Frequent cellular senescence in small bile ducts in primary biliary cirrhosis: a possible role in bile duct loss

The pathogenesis of progressive bile duct loss in primary biliary cirrhosis remains unclear. In this study, the involvement of cellular senescence of biliary epithelial cells was examined in liver tissue samples from patients with primary biliary cirrhosis (n = 33), and compared with control diseased and normal livers (n = 83). In addition, cellular senescence was induced by oxidative stress in cultured mouse biliary epithelial cells. Biliary epithelial cells in small bile ducts in primary biliary cirrhosis, especially those in patients presenting with chronic non-suppurative cholangitis, frequently expressed senescence-associated beta-galactosidase, and senescence-associated p16(INK4) and p21(WAF1/CIP). In contrast, senescence-associated markers were rarely expressed in small bile ducts in control livers. The infiltration of myeloperoxidase-positive inflammatory cells into biliary epithelial cell layers was closely associated with the cellular senescence of biliary epithelial cells in early-stage PBC. Cellular senescence of cultured mouse biliary epithelial cells was induced by treatment with H2O2 via the p38MAPK-dependent pathway and nitric oxide-augmented H2O2-induced cellular senescence. Oxidative stress- and nitric oxide-mediated cellular senescence may be involved in bile duct lesions, which are followed by progressive bile duct loss in primary biliary cirrhosis.     

Identification of neural genes using Xenopus DNA microarrays.

To isolate novel genes regulating neural induction, we used a DNA microarray approach. As neural induction is thought to occur by means of the inhibition of bone morphogenetic protein (BMP) signaling, BMP signaling was inhibited in ectodermal cells by overexpression of a dominant-negative receptor. RNAs were isolated from control animal cap explants and from dominant-negative BMP receptor expressing animal caps and subjected to a microarray experiment using newly generated high-density Xenopus DNA microarray chips representing over 17,000 unigenes. We have identified 77 genes that are induced in animal caps after inhibition of BMP signaling, and all of these genes were subjected to whole-mount in situ hybridization analysis. Thirty-two genes showed specific expression in neural tissues. Of the 32, 14 genes have never been linked to neural induction. Two genes that are highly induced by BMP inhibition are inhibitors of Wnt signaling, suggesting that a key step in neural induction is to produce Wnt antagonists to promote anterior neural plate development. Our current analysis also proves that a microarray approach is useful in identifying novel candidate factors involved in neural induction and patterning.