METHODS: The cytotoxic effects of As2O3 on five myeloma ce ll lines U266, SKO-007, LP-1, HS-Sultan, and KM3 were examined using MTT bioa ssay, and the concentration of 50%growth inhibition (IC50) was calculated. The synergistic or antagonistic effects of menadione (VK3), N-acetyl-cysteine (NAC ), and reduced glutathione (GSH) combined with As2O3 were also examined.

(0.1、0.2mg. kg-1*** p<0.01 vs saline), phy can increased the rat's choice percentage on delayed time in 810scc (0.1mg . kg-1** p<0.05; 0.2mg . kg-1. *** p<0.01 vs saline), and had antagonistic effects on memoria detriment by Scop.

Among which 16 strains showed good antagonistic effects with 6—11mm inhibition zone diameter and＞2.0 antagonistic coefficient, 7 of 16 strains showed steady antagonistic effects.

0.75,1.50 and 3.00 mg/kg of sodium selenite presented antagonistic effects against DNA damage induced by 250 mg/kg of BaP in mouse's lung cells. The antagonistic effect of sodium selenite at the dose of 1.50 mg/kg was better than those of sodium selenite at the doses of 0.75,3.00 mg/kg.

By inoculated to tobacco plants, six strains could be re-isolated from the inoculated plants, indicating that they were endophytic bacteria in tobacco. Culture these eight bacteria and Phytophthora parasitica var. nicotianae together, the result showed four endophytic bacteria YN-55, NN-3, YN-4 and YN-10 have the best antagonistic effects.

254 strains were isolated and purified from the soil samples, which were collected from rhizosphere of the crop in the suburban districts of Shanghai from 2003 to 2005. One strain of P13 was screened out from 254 isolates, which expressed stronger antagonistic effects on Sclerotinia sclerotiorum trough dual culture method.

Similar antagonistic effects of BN_3A(0.01, 0.1, 1 and 10 μg·ml~(-1)), BN_3B (0.05, 0.5 and 5 μg·ml~(-1)) and BN_3C (5 μg·ml~(-1)) wereobserved when the immunosuppressive drug hydrocortisone was substituted by cyclosporin A.

The antagonistic effects of SOD-1 on arrhythmia induced by ET-1 were dose-related. And the arrhythmia score in the group pretreated with SOD-1 0.1 mg/kg administered into proxial LAD was 0.20± 0.17, significantly lower than that in the ET-1 group in cats(5. 17±1. 60,P<0. 05).

APS(50 to 250 μg/ml)and GS( 1. 0 to 100 μg/ml) showed significant in vitro antagonistic effects on increased ratio of cAMP /cGMP in stimulated macrophages and splenocytes from traumatized mice.

Nitric oxide, produced from exogenous NO donor, sodium nitroprusside, and hydrogen peroxide exerted antagonistic effects on tobacco leaves at micromolar concentrations but induced synergistic effects at millimolar concentrations.

Recent findings on different subtypes of estrogen receptors (ER-α and ER-β) may explain some antagonistic effects as proliferation in the one (endometrium) and anti-proliferation in the other (vascular wall) tissue.

In previous experiments PY 108-068 (PY) has been found to have more potent calcium antagonistic effects on vascular smooth muscle than on myocardial tissue.

These agents have additional antagonistic effects at histamine H1, muscarinic cholinergic, α1-adrenergic, α2-adrenergic and dopamine receptors, but drugs which are selective for these non-5-HT receptors appear to be of no benefit in migraine.

Transforming growth factor beta1 (TGF-beta1) has antagonistic effects on TNF-alpha and IL-1-mediated processes.

The combined toxicity of sodium antimony gluconate (SAG_(sb)~v) and tartar emetic (PAT_(sb)~Ⅲ) was analysed in mice according to Loewe's method. It was found that when sodium antimony gluconate in the doses of 1/4, 1/2, and 3/4 respectively of its LD_(50) was used in combination with tartar emetic, a marked antagonistic effect in their toxicities occured.

Based on the known histological and electrophysiological data concerning the receptive fields of the vertebrate retina, a mathematical model was proposed. This model consists of three layers of net-works in which net-work elements R of the first layer represent receptors, elements I of the second layer represent connective cells (including bipolar, horizontal and amarcrine cells) and elements G of the third layer represent ganglion cells. Suppose that I and G possess operating properties of spatial summation...

Based on the known histological and electrophysiological data concerning the receptive fields of the vertebrate retina, a mathematical model was proposed. This model consists of three layers of net-works in which net-work elements R of the first layer represent receptors, elements I of the second layer represent connective cells (including bipolar, horizontal and amarcrine cells) and elements G of the third layer represent ganglion cells. Suppose that I and G possess operating properties of spatial summation and of threshold and the connections between the elements of two neighbouring layers have two modes, one excitating (signed by 1) and the other inhibiting (signed by-1), then the one-dimensional discrete model is expressed as follows:g=[W·[K·AR]_α]_β(1)where g is the output of a ganglion cell,A=(α_1 α_2…α_n)is a vector which represents the light spot input,K=(K_11 K_12 K_13 …K_(1n) K_(21) K_(22) K_(23) …K_(2n) ……K_(m1) K_(m2) K_(m3) …K_(mn)) is the connection matrix between the first and the second layers,W=(w_1,w_2,w_3,…w_m)is the connection matrix between the second layer and the ganglion cell, α and β represent the thresholds of cells belonging to the second layer and ganglion cells respectively and R describes the characteristics of the receptors.Equation (1) can also be written as follows:In some aspects, this model conforms qualitatively with electrophysiological data on receptive fields conducted with small spot lights, i. e.(1) When various values of K were taken, this model qualitatively shows correspondingly the properties of on-center RF, off-center RF and on-off RF.(2) So far as on-RF and off-RF are concerned, this model has three different response regions and shows the antagonistic effect among different regions.(3) For any receptive field, this model presents the property that within the receptive field the excitation level varies with different regions. The model also possesses perfect summation region, partial summation region and inhibition region.Methods are also suggested for the construction of some models having special spatial properties.The model was further extended to a two-dimensional, continuous form:(3) where k (x, y, ξ, η)is a weighting function. When k is taken as a kind of spatial invariant linear system then (3) can be written as (4)The significance of the system in information processing of the visual system is also discussed.

Based on the known histological and electrophysiological data concerning the receptive fields of the vertebrate retina, a mathematical model was proposed. This model consists of three layers of net-works in which net-work elements R of the first layer represent receptors, elements I of the second layer represent connective cells (including bipolar, horizontal and amarorine cells) and elements G of the third layer represent ganglion cells. Suppose that I and G possess operating properties of spatial summation...

Based on the known histological and electrophysiological data concerning the receptive fields of the vertebrate retina, a mathematical model was proposed. This model consists of three layers of net-works in which net-work elements R of the first layer represent receptors, elements I of the second layer represent connective cells (including bipolar, horizontal and amarorine cells) and elements G of the third layer represent ganglion cells. Suppose that I and G possess operating properties of spatial summation and of threshold and the connections between the elements of two neighbour ing layers have two modes, one excitating (signed by 1) and the other inhibiting (signed by-1), then the one-dimensional discrete model is expressed as follows:g=[W·[K·AR]_α]_β (1)where g is the output of a ganglion cell,is a vector which represents the light spot input,is the connection matrix between the first and the seoond layers,W=(w_1, w_2, w_3,…w_m)is the connection matrix between the second layer and the ganglion cell, α and β represent the thresholds of cells belonging to the second layer and ganglion cells respec tively and R describes the characteristics of the receptors.Equation (1) can also be written as follows:In some aspects, this mode] conforms qualitatively with electrophysiologioal data on receptive fields conducted with small spot lights, i. e.(1) When various values of K were taken, this model qualitatively shows corres pondingly the properties of on-center RF, off-center RF and on-off RF.(2) So far as on-RF and off-RF are concerned, this model has three different response regions and shows the antagonistic effect among different regions.(3) For any receptive field, this model presents the property that within the recep tive field the excitation level varies with different regions. The model also possesses perfect summation region, partial summation region and inhibition region.Methods are also suggested for the construction of some models having special spatial properties.The model was further extended to a two-dimensional, continuous form:where k (x, y,ξ, η)is a weighting function. When k is taken as a kind of spatial invariant linear system then (3) can be written asThe significance of the system in information processing of the visual system is also discussed.