Similar Joint Action Research Articles

Assessment of so called organic trace compounds in drinking water from the regulatory, health and aesthetic-quality points of view, with special consideration given to pharmaceuticals

More than 2500 chemically defined substances are approved as drugs in Germany. Unlike agricultural pesticides, these biologically active structures are not used in open environmental compartments and therefore their environmental toxicological data base is not nearly as complete. Nevertheless, some of them become environmental contaminants after their intended use. Therefore, from the viewpoint of environmental health protection, there are gaps in their health-related environmental risk assessment. Organic trace compounds that lack an adequate toxicological database, and their mixtures, in drinking water can be safely regulated and provisionally assessed by combining the "similar joint action" addition rule with the recommendation of the Federal Environment Agency of March 2003 "Assessing the presence of substances in drinking water without (adequate) toxicological database from the health point of view". The general precautionary value (Gesundheitlicher Orientierungswert GOW1=0.10 microg/l), which is a recommendation for weakly to not genotoxic compounds, re presents a workable compromise between preventive health protection, water management considerations and aesthetic quality claims (purity). Compliance with this value in the long term will only be possible if the chemical and biological degradation of pharmaceuticals and their metabolites in waste water and waste water treatment plants is effectively improved. Alternatively, there is the risk of drinking water degenerating into a sink for highly mobile, polar and persistent compounds. Their elimination at a stage as late as technical drinking water treatment would be neither close to the initial cause nor justifiable in terms of technical effectiveness. The risk assessment of their byproducts would give rise to further uncertainties. Possible conflicts with the therapeutic quality must be solved by developing substitute products which are environmentally sound.

Modification of allelopathic effects ofp-coumaric acid on morning-glory seedling biomass by glucose, methionine, and nitrate

Studies of allelopathy have emphasized primarily the identification and quantification of phytotoxins in soils, with only limited attention directed toward how organic (carbon) and inorganic constituents (nutrients) in the soil may modify the action of such phytotoxins. In the present study, increasing carbon (C) levels (up to 108μg C/g soil) supplied as glucose, phenylalanine, orp-hydroxybenzoic acid did not alter morning-glory biomass, but similar C levels supplied as leucine, methionine, orp-coumaric acid were inversely related to morning-glory biomass. Similar joint action and multiplicative analyses were used to describe morning-glory biomass response to various C sources and to generate dose isolines for combinations ofp-coumaric acid and methionine at two NO3-N levels and for combinations ofp-coumaric acid and glucose at one NO3-N level. Methionine, glucose, and NO3-N treatments influenced the inhibitory action ofp-coumaric acid on biomass production of morning-glory seedlings. For example, results from the multiplicative analysis indicated that a 10% inhibition of morning-glory biomass required 7.5μgp-coumaric acid/g soil, while the presence of 3.68μg methionine/g soil thep-coumaric acid concentration required for 10% inhibition was only 3.75μg/ g soil. Similar response trends were obtained forp-coumaric acid and glucose. The higher NO3-N (14 vs. 3.5μg/g) treatments lowered the methionine and increased thep-coumaric acid concentrations required for 10% inhibition of morning-glory biomass. These results suggested that allelopathic interactions in soil environments can be a function of interacting neutral substances (e.g., glucose), promoters (e.g., NO3-N), and/or inhibitors (e.g., methionine andp-coumaric acid) of plant growth.

Simple similar action and independent joint action - two similar models for the joint effects of toxicants applied as mixtures

Two commonly referenced modes of joint action, simple similar joint action (SSA) and independent joint action (IJA), in their simplest forms, are assumed to describe very different types of action by toxicants. SSA is assumed to describe toxicants that act similarly and at the same sites of action, and IJA to describe toxicants that act differently or at different sites of action. It is demonstrated in this paper that maintaining both models and their common variations is not practical for the development of larger and more inclusive models. It is shown that the ranges of responses that can be described by common simple variations of both models are very similar. It is also argued that the two models in their simplest forms are not alternative hypotheses since they are expressions about different variables. Moreover, since toxicants often cannot be uniquely described as acting similarly, dissimilarly or at only one site of action, it is argued that only one of the above models and its expanded forms should be used to describe the results of experiments with a diversity of toxicants. Variations of the probit response model are believed to be more desirable because they resemble a model used to make predictions about the effects of complex mixtures, namely the toxic units model.

Dose-response functions in aquatic toxicity testing and the Weibull model

A linear transformation of the Weibull model for dose-response functions is developed. The transformation is analogous to the probit and logit transformations. Typical dose-response curves in aquatic toxicity testing using macroorganisms and algae are analyzed by the Weibull and probit models, and it is shown that the Weibull model generally provides at least as good a fit to experimental data as the probit model. The expansion of the Weibull model to reflect the survival fraction or yield of organisms under multiple toxicant limiting conditions leads to particularly useful expressions for simple similar joint action (concentration addition with parallel response curves for the individual toxicants) and independent joint action (response multiplication). Explicit water quality criteria are derived based on both formulations. The multiple toxicity models, expanded to include concentration addition with non-parallel response curves for the individual toxicants, are applied to algal assay data for Selenastrum capricornutum exposed to manganese, copper, and lead. The fact that the yield based on response multiplication for the manganese-lead pair is lower than that calculated from concentration addition suggests that water quality criteria based on concentration addition may not always provide safe limits.

Joint Action of Methomyl and Synthetic Pyrethroids AgainstHeliothis armigeraandHeliothis punctigera

Abstract The joint action of 8:1 and 9.3:1 mixtures of methomyl + fenvalerate against Heliothis armigera and H. punctigera respectively, and of methomyl + deltamethrin (9:1) against H. armigera was investigated in the laboratory by topical application. Methomyl + fenvalerate showed similar joint action against both species and methomyl + deltamethrin was antagonistic against H. armigera.

Toxicological studies on a beetle, Alphitobius Zaevigatus (F.)

SUMMARYA series of joint action experiments was done using 4,6‐dinitro‐2‐n‐butylphenol and 4,6‐dinitro‐2‐sec‐butylphenol in solution in Risella 17 oil. The following were tested: (1) the joint action of doses of the n‐butyl compound on two sites of application on the beetle, the mesoscutellum and the hind coxae; (2) the joint action of doses of the sec‐butyl compound on the two sites; (3) the joint action of the two compounds applied to the mesoscutellum; and (4) the joint action of the two compounds applied to the hind coxae.The data obtained were interpretable on the assumption that the joint action of the doses (whether of one compound on the two sites, or of the two on one site) was simply similar, with complete positive correlation of tolerances, and that the amount of toxicant reaching the site of action was proportional to the dose (volume of solution) raised to the power of η, where η < 1. This meant that the joint applications were more toxic than was predicted by an equation for similar joint action given by Finney (1952), which in effect makes the assumption that η= 1. In the portion of the present work in which the results can be so expressed, the joint applications ranged from 1·11 to 1·51 times as toxic as the predictions by Finney's equation. The estimates of 7 ranged from 0·62 to 0·87, with a mean of 0·755 ± 0·037. The finding that the joint toxicities were higher than predicted by Finney's equation agrees with predictions made by Plackett & Hewlett (1952) and by Hewlett & Plackett (1959, 1961). Experiments with the see‐butyl compound indicated that values of η < 1 were not interpretable on the hypothesis that the coefficient of regression of probits on log‐concentration was greater than that on log‐volume, for estimates of the two coefficients were not significantly different.

Insecticidal activity of pyrethrum extract and its four insecticidal constituents against house flies. I.—Preparation and relative toxicity of the pure constituents; Statistical analysis of the action of mixtures of these components

AbstractPyrethrins I and II and cinerins I and II were isolated from commercial pyrethrum extract by displacement chromatography and were also reconstituted from the naturally derived acids and alcohols. The samples of each constituent isolated from both sources had identical chemical and physical properties, and were of the same insecticidal potency within the limits of experimental error. The relative toxicities of the four constituents to female house flies (Musca domestica L.), determined at 20° by a measured drop technique, were: pyrethrum extract, 1.0; pyrethrin II, 1.3‐ 1.5; pyrethrin I, 0.9‐1.0; cinerin II, 0.5‐0.6; cinerin I, 0.4‐0.5. The insecticidal activity of a mixture of the four constituents was examined statistically for simple similar joint action, assuming that the probit‐log‐dose lines for the separate constituents were not parallel; the predicted results are in good agreement with the experimental data. The procedures for computing the responses predicted by simple similar joint action are discussed.

The toxicity of mixtures of zinc and copper sulphates to rainbow trout (Salmo gairdnerii Richardson)

SUMMARYThe toxicity to rainbow trout of a mixture of zinc and copper sulphates in relatively low concentrations can be calculated from the toxicities of the individual metals by assuming that they exert a similar joint action. Higher concentrations of the mixture in soft water exhibit a synergistic action.

Induction of ovulation in mice with placental gonadotrophins.

SUMMARY The ovulation response was measured, by the recovery of tubal ova, in mature dioestrous albino mice after single injections of gonadotrophin, using three preparations of pregnant mares' serum (PMS) and three of human chorionic material (HCG). The dose-response lines were parallel over a limited part of the range, and similar joint action of PMS and HCG was demonstrated within these limits. Higher doses of HCG inhibited ovulation, whereas higher doses of PMS induced superovulation. The double injection technique (priming followed by ovulating injections) was examined in experiments of factorial design in immature normal and immature hypophysectomized mice. Both PMS and HCG may be used as priming or ovulatory substances in normal mice, though the equivalent doses are different for the two functions. The optimal time interval between priming and ovulatory injections, the effect of time from weaning and the response of two additional strains of mice were also examined.

Antispasmodic activity of two substituted benzhydryl derivatives

The joint action of diethylaminoethyl benzylic acid ester methyl bromide (FWH-101) and β-dimethylaminoethyl ( p-chloro-α-methyl) benzhydryl ether hydrochloride (chlorphenoxamine) has been studied as to the modification of acute toxicity and antispasmodic activity in vivo. The intraperitoneal LD 50 of each compound was significantly increased when simultaneously administered with the LD 50 of the other. Using an in situ ileal preparation in the cat and the “charcoal meal” test in the intact rat, a marked increase in antispasmodic activity was observed. Quantitative data are presented to demonstrate a potentiation of pharmacologic effect which appears to be similar joint action.

Anticonvulsant Drug Combinations: Diphenylhydantoin CoLbined with Other Antiepileptics

Methods are presented for the study of drug combinations in which one component is active by the anticonvulsant test and both components are active by the neurotoxicity test. The effects of Dilantin on anti-Metrazol activity and neurotoxicity of five clinically useful antiepileptics were determined in mice and protective indices calculated. The anti-Metrazol activity of two combinations of Dilantin-Phenurone was significantly greater than that of Phenurone alone. The minimal neurotoxic doses of all combinations of Dilantin-Tridione and Dilantin-Mesantoin were significantly larger than those calculated on the basis of similar joint action of toxicities. The margin of safety of one combination of Dilantin-Mesantoin was significantly increased over that of the active component alone.

Joint action of gonadotrophic substances.

SUMMARY Four experiments are described in which the joint action of certain pairs of six gonadotrophic preparations was studied. In every case similar joint action was demonstrated using the uterine weight in the immature mouse as the criterion of response. These results are discussed with regard to the early action of gonadotrophins on the immature mouse ovary.

SIMILAR joint action of insecticides.

BLISS1 defined the similar joint action of poisons in such a way that the quantal responses to mixtures of poisons acting similarly could be predicted from the separate toxicities of the components of the mixtures. Finney2 revised Bliss's treatment of the subject, and both Finney2 and Swisher3 have shown that mixtures of certain insecticides were of the toxicity so predicted. If z1 and z2 are the doses of poisons A and B respectively, the probit responses, y, produced by A and B alone are usually given respectively by: Provided, and only provided, that β1 = β2 = β, the probit response to z1 of A and z2 of B applied together is, according to Bliss's scheme, predicted by Finney's equation (8.4), which may be conveniently expressed in the form: where h is the base of the logarithms. Equation (3) reduces to (1) or (2) as z2 or z1 is made zero. Bliss's hypothesis of similar action does not permit A and B to act similarly if β ≠ β2.