New species of Hercostomus Loew, 1857 (Dolichopodidae, Diptera) from Japan.

Six new species of the genus Hercostomus Loew, 1857, are described from Japan: Hercostomus acutiformis Negrobov, Kumazawa & Tago sp. nov., H. falcilis Negrobov, Kumazawa & Tago sp. nov., H. flavipalpus Negrobov, Kumazawa, Tago & Sato sp. nov., H. nigricollaris Negrobov, Kumazawa & Tago sp. nov., H. spathulatus Negrobov, Kumazawa, Tago & Sato sp. nov., H. spinitibialis Negrobov, Kumazawa & Tago sp. nov. Hercostomus flaveolus Negrobov & Chalaya, 1987 is newly recorded from Japan, and Hercostomus arcticus Yang, 1996 is newly synonymized with Hercostomus flaveolus (syn. nov.). The holotype of Hercostomus flaviventris Smirnov & Negrobov, 1979 is redescribed. Hercostomus ussurianus Stackelberg is transferred to the genus Gymnopternus Loew, 1857 (stat. nov.). A key to the eleven recognized species of Japanese Hercostomus is provided.

Thermal stability of an SiO2-coated Rh catalyst and catalytic activity in NO reduction by CO.

An SiO2-coated Rh catalyst with SiO2 thickness of 13 nm has much higher stability against sintering of Rh and SiO2 than sol-gel and impregnation Rh/SiO2 catalysts; it exhibits the highest activity in the NO-CO reaction among these catalysts after thermal treatment.

Use of a catecholamine sensor in the control of an artificial heart system.

An electrochemical sensor system to allow real-time measurement and feedback of catecholamine concentrations was developed for use in the control of artificial hearts. Electrochemical analyses were carried out using a carbon fiber working electrode, an Ag-AgCl reference electrode, and a potentiostat. The operating parameters of the pneumatically-driven artificial heart system were altered in accordance with the algorithm for changes in the catecholamine concentration. The minimum detectable concentrations of both adrenaline and noradrenaline in a mock circulatory system using a phosphate-buffered solution were approximately 1-2 ng/ml (10(-8) mol/L). An artificial heart control system utilizing this set-up performed satisfactorily without delay, although sensor sensitivity decreased when placed in goat plasma instead of a phosphate-buffered solution, due to the adsorption of various substances such as plasma proteins onto the electrodes. This study demonstrated the future feasibility of a feedback control system for artificial hearts using catecholamine concentrations.

Antitumor effects of a nonsteroidal aromatase inhibitor (CGS 16949A) on 7, 12-dimethylbenz[alpha]anthracene-induced mammary tumors in rats.

The effects of a nonsteroidal aromatase inhibitor, CGS 16949A, on female Sprague-Dawley (SD) rats with 7, 12-dimethylbenz[alpha]anthracene (DMBA)-induced mammary cancers were examined in relation to estrogen receptors (ER). Rat tumor sizes in each treated group were significantly smaller (P less than 0.05) and rat body weights in most treated groups were significantly increased (P less than 0.05) compared to those in the control group (no treatment) at all measurement points during treatment. Rat uterine weights in each treated group decreased significantly compared with those in the control group (P less than 0.05). There was no significant difference between ER-positive and ER-negative groups in tumor size, body weight or uterine weight. At increased doses of CGS 16949A in the experiment, further increases in testosterone levels and further decreases in estradiol levels were shown to occur. The results suggest the mechanisms of CGS 16949A action not to be influenced by the presence or absence of ER, but to be due to its potent aromatase inhibition of the conversion of androgens to estrogens.

Effects of sequential and combined immuno-endocrine therapies using OK-432 (Picibanil) and tamoxifen on the growth of 7,12-dimethylbenz [alpha] anthracene-induced rat mammary carcinoma.

Effects of sequential and combined immuno-endocrine therapies using OK-432 (Picibanil) and tamoxifen (TAM) on the growth of 7,12-dimethylbenz [alpha] anthracene (DMBA)-induced carcinoma were examined in 128 female Sprague-Dawley (SD) rats. The rats were divided into six groups: control (no treatment), tamoxifen, OK-432, simultaneous immuno-endocrine OK-432 and TAM (OK-432 + TAM) therapy, two types of sequential immuno-endocrine therapy of the OK-432 and TAM groups [OK-432 (1 wk)----TAM (4 wk) and OK-432 (2 wk)----TAM (3 wk)]. Each group was treated consecutively for five weeks. The response rates in the TAM alone group, the [OK-432 (1 wk)----TAM (4 wk)] group and the [OK-432 + TAM (5 wk)] group were significantly higher than in the control group. When the results among the treated groups were compared, the response rate in the [OK-432 (1 wk)----TAM (4 wk)] group was significantly higher than in the OK-432 alone or TAM alone groups. The response rate in the [OK-432 (2 wk)----TAM (3 wk)] group, however, was lower than in the TAM alone group. The response rate in the OK-432 + TAM group was, moreover, not significantly superior to that in the TAM alone group. These results suggest OK-432 not to potentiate the antitumor effect of TAM since the response rate of the combined OK-432/TAM therapy was not always significantly superior to that of the TAM treatment.