Systematic position of two Pliocene carditids with description of Akardita n. gen. and A. iberica n. sp. (Bivalvia: Carditidae).

Akardita n. gen. is described for a small Pliocene to Recent group of carditids. The type species is Cardita subrevoluta de Stefani, 1888, from the lower Pliocene of Italy. The new genus includes Akardita iberica n. sp., from the lower Pliocene of southern Spain, and Cardita (Venericardia) monodi Nicklès, 1953, an extant species from West Africa. A few additional Neogene species from Europe could turn out to be representatives of the new genus, whose disappearance from European seas seems to be related to an increasing cooling trend during the Neogene-Pleistocene interval. Because of the confused status of carditid taxonomy, about which some observations are reported in the present work, it is not possible to assign the new genus to any of the traditional subfamilies.

Gene expression of transforming growth factor beta receptors I and II in non-small-cell lung tumors.

Transforming growth factor (TGF)beta inhibits normal epithelial cell proliferation. A decreased expression of TGFbeta receptors (TbetaR) has been associated with loss of TGFbeta sensitivity and enhanced tumor progression in many types of cancer. Although lung cancer is one of the leading causes of cancer death, a comparative analysis of TbetaR mRNA and protein expression in non-small-cell (NSC) lung tumors has not been performed. Lung tumor tissues and control non-lesional lung tissues were obtained from 17 patients undergoing thoracotomy for primary NSC lung tumors in clinical stage II. Each tissue sample was studied for TbetaRI and TbetaRII mRNA and immunoreactive protein expression, using a semi-quantitative reverse transcription-PCR method, and a quantitative immunohistochemistry method, respectively. TbetaRI protein expression was higher in tumors than in controls (p=0.0005) and a similar trend was present at the mRNA level. TbetaRII protein expression was not significantly different between tumors and controls, however an intense peri-nuclear staining for TbetaRII was observed in several tumor cells. TbetaRII mRNA levels were lower in tumors than in controls (p=0.005) and an inverse relation between TbetaRII mRNA and protein expression was detected in tumors (p=0.0013). Our findings suggest an altered function of the TbetaR system in NSC lung cancer.

Synergistic inhibitory activities of interleukin-10 and dexamethasone on human CD4+ T cells.

BACKGROUND: We have previously demonstrated that interleukin (IL)-10 synergizes with dexamethasone (Dex) in inhibiting proliferation of human T cells, stimulated in an antigen-presenting cell (APC)-dependent manner. Because IL-10 effectively inhibits APC accessory functions, the synergism could have been a result of its effect on APC. We then investigated the effects of Dex and IL-10 on T-cell subpopulations, stimulated in an APC-independent manner. METHODS: CD4 and CD8 T cells were stimulated with anti-CD3, with or without Dex and IL-10, alone or in combination. Proliferation, glucocorticoid (GC) receptor binding, anti-CD3-induced tyrosine phosphorylation, IL-2 production, and expression of IL-2 receptor alpha, beta, and gamma chains were evaluated. The pharmacologic interactions were analyzed using the isobole method. RESULTS: IL-10 synergized with Dex in inhibiting CD4 but not CD8 T-cell proliferation. The synergism was not associated with modifications of GC receptor number or affinity, nor with modifications of anti-CD3-induced tyrosine phosphorylation. IL-10 synergized with Dex in inhibiting IL-2 production and increased Dex inhibitory effect on the expression of the IL-2 receptor alpha chain, which is up-regulated by CD3 stimulation and IL-2. Only Dex inhibited the beta and gamma chain expression, which, interestingly, is not up-regulated by IL-2. IL-2, as well as IL-7 and IL-15, reversed the effects of IL-10 but not those of Dex. CONCLUSIONS: IL-10 synergizes with Dex in inhibiting CD4 T-cell proliferation. Its synergizing effect is mediated by the inhibition of IL-2 production. Dex exerts additional activities, such as the inhibition of beta and gamma chain expression. Therefore, IL-10 could be useful for the enhancement of GC-based immunosuppressive therapies.

Inhibition of cGMP-dependent protein kinases potently decreases neutrophil spontaneous apoptosis.

The signalling pathways mediating neutrophil spontaneous apoptosis are still largely unknown. We report that the indolocarbazole compound KT5823, a specific inhibitor of cGMP-dependent protein kinases (cGK), dose-dependently inhibited spontaneous apoptosis of neutrophils. At the concentration eliciting the maximum effect (8 microM), it decreased apoptosis from 72.42+/-12.79% to 45.86+/-7.22% (p=0.0002, n=6). Similarly, the isoquinoline sulfonamide compound H89, another cGK inhibitor, prevented neutrophil apoptosis. At the concentration eliciting the maximum effect (20 microM), it decreased apoptosis from 72.42+/-12.79% to 31.84+/-10.70% (p=0.0004, n=6). The maximum effect of KT5823 and H89 was comparable to that of GM-CSF and LPS, respectively. Moreover, YC-1, a soluble guanylate cyclase activator, and 4-([3',4',-(methylenedioxy)benzyl]amino)-6-methoxyquinazoline, a specific phosphodiesterase 5 inhibitor, enhanced neutrophil apoptosis, and their effect was antagonised by KT5823. Taken together, these observations highlight a new role of cGK as important mediators of neutrophil spontaneous apoptosis.