Serum Cytokines in Patients with Legionella Pneumonia: Relative Predominance of Th1-Type Cytokines

Serum samples from 14 patients with Legionella pneumonia were examined for the presence of cytokines. In spite of high levels of serum C-reactive protein in all patients during the acute phase in only four cases (one involving interleukin-1β [IL-1β], three involving IL-6, and none involving tumor necrosis factor alpha) was the concentration of cytokines more than 100 pg/ml. Th2 cytokines IL-4 and IL-10 were detected in only one patient each. In contrast, significant increases of serum gamma interferon (IFN-γ) and IL-12 levels were observed during the acute phase in 6 and 11 cases, respectively. Interestingly, although serum IFN-γ levels diminished thereafter, in seven cases IL-12 levels remained high or increased further during the convalescent phase. In an additional 22 cases clinically suspected to be but not diagnosed as Legionella pneumonia, increases of serum IL-12 levels were observed in 16 cases, whereas the remaining 6 cases showed no detectable IL-12. Our results demonstrate the relative predominance of Th1 cytokine production in Legionella pneumonia. Although the role and significance of prolonged increases in IL-12 levels in Legionella disease are unknown, our results should prompt further investigation of the host immune response in terms of Th1 and Th2 balance in legionellosis.     

Kupffer cell-mediated cytotoxicity against hepatoma cells occurs through production of nitric oxide and adhesion via ICAM-1/CD18

Rat Kupffer cell (KC)-mediated cytotoxicity against both thesyngeneic hepatoma cell line AH70 and hepatocytes was evaluatedby changes in mitochondrial function, and the possible roleof ICAM-1/CD18 in the interaction between the cells was studied.Rhodamine 123 fluorescence, a marker of the mitochondrial membranepotential, decreased in AH70 cells after co-culture with KC,while that in hepatocytes was unchanged by co-culture. Thisdecrease was blocked by anti-ICAM-1, anti-CD18 and the Inhibitionof nitric oxide synthesis. Cytometric studies demonstrated thatICAM-1 expression on AH70 cells increased after addition ofIFN-, IL-1ß, tumor necrosis factor (TNF)- or KC, whilein hepatocytes ICAM-1 was not increased. Anti-ICAM-1 pretreatmentinhibited the increase in ICAM-1 expression and the decreasein rhodamine 123 fluorescence on AH70 cells after co-culturewith KC. CD18 on KC was increased only after co-culture withAH70. TNF- but not IFN- was detected in the supernatant of co-culturebetween KC and AH70 cells, and this production was partiallyinhibited by anti-ICAM-1 and anti-CD18. The activity of Induciblenitric oxide synthase in Kupffer cells and the levels of nitritesand nitrates in the co-culture supernatant increased over time,and this increase was attenuated either by addition of NO synthesisinhibitors, anti-ICAM-1 or anti-CD18. These results indicatethat the rat KC causes mitochondrial dysfunction in cancer cellsvia the production of NO and cell-to-cell adhesion via ICAM-1/CD18has an Important role in this cytotoxic process.     

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.     

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.     

Sarcomatoid carcinoma of the urinary tract

Sarcomatoid carcinoma is a rare variant of malignant tumor arising from the urinary tract. This tumor had been termed carcinosarcoma because of its carcinomatous and sarcomatous components. There is still some confusion in the terminology between true carcinosarcoma and sarcomatoid carcinoma; however, the latter is now regarded as primarily a malignant epithelial tumor with pseudosarcomatous transformation.
Four cases of sarcomatoid carcinoma arising from the urinary tract are reported. The patients were a 77 year old female, and three males aged 62, 69 and 80 years. All but the eldest patient complained of gross hematurla. Surgical removal was performed in the younger three cases, and an autopsy was done in the remaining case. All the tumors were macroscopically polypoid. Histopathologic examination revealed fasciculated spindle-cell tumors with myxold stroma or malignant fibrous histiocytoma-like spindle cell tumors. The epithelial nature was proven in these sarcomatous cells by immunohistochemical andlor electron-microscopic examinations. Only a small amount of squamous cell carcinoma components was also evident in the latter three cases. Although the younger three patients were alive at 44, 23 and 39 months'follow-up, respectively, constant careful monitoring Is recommended.