Role of plants, mycorrhizae and phytochelators in heavy metal contaminated land remediation.

Phytoremediation is a site remediation strategy, which employs plants to remove non-volatile and immisible soil contents. This sustainable and inexpensive process is emerging as a viable alternative to traditional contaminated land remediation methods. To enhance phytoremediation as a viable strategy, fast growing plants with high metal uptake ability and rapid biomass gain are needed. This paper provides a brief review of studies in the area of phytoaccumulation, most of which have been carried out in Europe and the USA. Particular attention is given to the role of phytochelators in making the heavy metals bio-available to the plant and their symbionts in enhancing the uptake of bio-available heavy metals.

Trace metals in oysters and sediments of Botany Bay, Sydney.

Trace metal concentrations (Pb, Cd, Cu and Zn) in Sydney rock oysters (Sacostera commercialis) and sediments (< 53 microns fraction) were determined for six sites in the northern regions of Botany Bay. Levels for lead, cadmium, copper and zinc in oysters ranged (in microgram g-1) from 1.38 to 15.3, 1.81 to 16.3, 56.1 to 212 and 1806 to 2902, respectively. In sediments, levels ranged (in microgram g-1) from 599 to 4081, 3.57 to 91.0, 191 to 1113 and 227 to 1472, respectively. Such values indicated high levels of contamination, especially in the sediments. Indeed, high proportions of the samples displayed metal concentrations that exceeded the prescribed limits for oysters and sediments. No significant correlations in metal concentrations were found between oysters and sediments, suggesting that changes in the sediment metal loading are not solely influencing the levels of bioavailable metal. The results supported the conclusion that different rates and mechanisms of metal accumulation are taking place in the two types of samples. Variability between sites was high, particularly for oysters. Multidimensional scaling identified that the Cooks River (site 3) and La Perouse (site 6) sites were most dissimilar, both to each other as well as to the other four sites. This was a reflection of high contamination in the Cooks River and the generally low levels in the La Perouse reference sample. The configuration was mainly influenced by the sediment parameters, rather than the oyster metal concentrations, indicating the sediment data were better for identifying site similarities. These ordinations provide evidence of the usefulness of multidimensional scaling in elucidating the physico-chemical variability of the sampling sites.

Aminophylline fails to improve the outcome of cardiopulmonary resuscitation from prolonged ventricular fibrillation: a placebo-controlled, randomized, blinded experimental study.

OBJECTIVES: The purpose of this study was to evaluate systematically the effects of the adenosine antagonist aminophylline on resuscitation outcome in a canine model of postcardioversion nonperfusing rhythm. BACKGROUND: Theoretic considerations and experimental studies indicate that myocardial adenosine accumulation during prolonged ventricular fibrillation might play a significant role in postcardioversion asystole and electromechanical dissociation. A recent uncontrolled clinical trial has suggested that the adenosine antagonist aminophylline might improve the outcome of cardiopulmonary resuscitation from refractory bradyasystolic cardiac arrest. METHODS: Two placebo-controlled, randomized, blinded experimental studies were performed. In protocol 1 (20 dogs), ventricular fibrillation was induced and maintained for 7.5 min. Sixty seconds before cardioversion, dogs received 1 mg of epinephrine followed by 250 mg of aminophylline or placebo. In protocol 2 (20 dogs), dogs were cardioverted to electromechanical dissociation after 5 min of unsupported ventricular fibrillation. Sixty seconds later, all dogs received 1 mg of epinephrine followed by 250 mg of aminophylline or placebo. In both experiments, resuscitation efforts were continued until return of spontaneous circulation, or up to 30 min. The primary end point was survival to 1 h. RESULTS: In protocol 1, 4 of 10 dogs survived in the aminophylline group, whereas 7 of 10 dogs survived in the placebo group, a nonsignificant trend toward unfavorable outcome from aminophylline. Pretreatment with aminophylline increased the number of cardioversion applications required to terminate ventricular fibrillation. In protocol 2, 5 of 10 and 6 of 10 dogs survived in the aminophylline and placebo groups, respectively. CONCLUSIONS: The results of this study suggest that aminophylline fails to improve the outcome of resuscitation from prolonged ventricular fibrillation. It does not reverse established electromechanical dissociation and may in fact increase the number of cardioversion applications required to terminate ventricular fibrillation. The rationale for conducting clinical trials with aminophylline during cardiopulmonary resuscitation is questionable.

Mixed function oxidases in sterol metabolism. Source of reducing equivalents.

Either NADH or NADPH can serve as a cofactor for oxidative demethylation of [30,31-14C]4,4-dimethyl-5 alpha-cholest-7-en-3 beta-ol and oxidative deformylation of 4-hydroxy[14C]methylene-5 alpha-cholest-7-en-3-one. This report suggests that the cofactors interact with these two oxidase systems differently depending upon whether the reduced cofactor arises intra- or extramicrosomally. Marked differences in oxidative activity are observed depending on whether NADPH is generated in the microsomes or is added as an exogenous cofactor. Thus, the concentration of added NADPH required to yield maximal rates of sterol oxidation is 500 muM or greater. Nearly equivalent rates of sterol oxidation are obtained from NADPH generated in the microsomes where the NADPH concentration is no greater than 0.454 muM. Similar results are observed with NADH. In this case, NADH is generated in the microsomes from added NAD+ by microsomal reactions. The rate of sterol oxidation when NADH is generated from added NAD+ is nearly the same as that obtained from added NADH; although the concentration of NADH generated from NAD+ is 0.403 muM, the concentration of added NADH is 100 muM, and Km for added NADH is 1.7 muM.

Factors limiting injury from pesticides.

Factors are discussed that may limit injury from pesticides whether the victims are exposed occupationally, through other intentional uses, or simply accidently. Emphasis is placed on choice of methods fitted to the problems revealed by dependable vital statistics for each country. In general, good labeling of pesticides is the most important single factor in their safe use. Regulation of use combining agricultural advice to the farmer with surveillance of his practices in the handling of pesticides often is the best way to minimize occupational poisoning and restrict residues on crops brought to market. To be successful, these and other aspects of education must be directed toward the improvement of human health. International organizations may be the best source of practical solutions simply because of the range of their experience.

Severe organophosphate poisoning complicated by alcohol and turpentine ingestion.

A 52-year-old comatose white male was admitted to the hospital with what was later learned to be severe poisoning by a turpentine solution of dicrotophos, an organophosphorous insecticide he had ingested while drunk. The patient was treated effectively with atropine and pralidoxime chloride and required the largest doses of both agents reported to data. The case was complicated by difficulty in evaluating the response to therapy because of the effects of alcohol and turpentine. The patient was discharged from the hospital on the thirty-third day with no apparent sequelae.

Mortality in 1969 from pesticides, including aerosols.

Among the 87 deaths in the United States in 1969 for which a causal relationship to pesticides could not be excluded, there were 62 valid accidents, 20 intentionally inflicted deaths, and five deaths incorrectly attributed to pesticides. The reduction in the number of such deaths compared to the decade and a half prior to 1962 probably involves a trend. As in the past, a disproportionate fraction of the victims were children, boys and men, and nonwhites. Findings in four cases (three in 1969) were consistent with the conclusion that intensive inhalation of an aerosol can sensitize the heart to fatal arrhythmia, even though there is no intentional misuse of the aerosol and no attempt to seek a thrill. Medical examiners should be alert to the possibility of such deaths associated with both pesticide and non-pesticide aerosols.

Studies on exposure during the use of anticholinesterase pesticides.

Relatively few studies have been made of the exposure of workers to pesticides. Of these, approximately half involved chlorinated hydrocarbon insecticides, and most involved agricultural applications. Some important matters, especially indoor spraying-e.g., for malaria control-have been investigated experimentally with DDT only. Fortunately, information on exposure during agricultural use-which is of considerable interest in itself-can serve as a rough guide in connexion with the exposures associated with vector-control activities. This paper reviews the different methods of measuring exposure and the significance of some of the results that have been obtained.