Safe use of metal-contaminated agricultural land by cultivation of energy maize (Zea mays).

Production of food crops on trace element-contaminated agricultural lands in the Campine region (Belgium) can be problematic as legal threshold values for safe use of these crops can be exceeded. Conventional sanitation of vast areas is too expensive and alternatives need to be investigated. Zea mays on a trace element-contaminated soil in the region showed an average yield of 53 ± 10 Mg fresh or 20 ± 3 Mg dry biomass ha(-1). Whole plant Cd concentrations complied with legal threshold values for animal feed. Moreover, threshold values for use in anaerobic digestion were met. Biogas production potential did not differ between maize grown on contaminated and non-contaminated soils. Results suggested favorable perspectives for farmers to generate non-food crops profitably, although effective soil cleaning would be very slow. This demonstrates that a valuable and sustainable alternative use can be generated for moderately contaminated soils on which conventional agriculture is impaired.

Economic viability of phytoremediation of a cadmium contaminated agricultural area using energy maize. Part I: effect on the farmer's income.

This paper deals with the economic viability of using energy maize as a phytoremediation crop in a vast agricultural area moderately contaminated with metals. The acceptance of phytoremediation as a remediation technology is, besides the extraction rate, determined by its profitability, being the effects it has on the income of the farmer whose land is contaminated. This income can be supported by producing renewable energy through anaerobic digestion of energy maize, a crop that takes up only relatively low amounts of metals, but that can be valorised as a feedstock for energy production. The effect on the income per hectare of growing energy maize instead of fodder maize seems positive, given the most likely values of variables and while keeping the basic income stable, originating from dairy cattle farming activities. We propose growing energy maize aiming at risk-reduction, and generating an alternative income for farmers, yet in the long run also generating a gradual reduction of the pollution levels. In this way, remediation is demoted to a secondary objective with sustainable risk-based land use as primary objective.

The use of bio-energy crops (Zea mays) for 'phytoattenuation' of heavy metals on moderately contaminated soils: a field experiment.

Worldwide there are numerous regions where conventional agriculture is affected by the presence of elevated amounts of plant-available trace elements, causing economic losses and food and feed quality and safety. The Belgian and Dutch Campine regions are a first-class example, with approximately 700 km(2) diffusely contaminated by historic atmospheric deposition of Cd, Zn and Pb. Primary land use in this region is agriculture, which is frequently confronted with crops exceeding the European standards for heavy metal contents in food and feed-stuffs. Phytoremediation as a soil remediation technology only appears feasible if the produced biomass might be valorised in some manner. In the current case, we propose the use of energy maize aiming at risk-reduction and generation of an alternative income for agriculture, yet in the long run also a gradual reduction of the pollution levels. Since the remediation aspect is demoted to a secondary objective with sustainable risk-based land use as first objective, we introduce the term 'phytoattenuation': this is in analogy with 'natural attenuation' of organic pollutants in soils where also no direct intended remediation measures but a risk-based management approach is implemented. In the current field experiment, cultivation of energy maize could result in 33,000-46,000 kW h of renewable energy (electrical and thermal) per hectare per year which by substitution of fossil energy would imply a reduction of up to 21 x 10(3)kg ha(-1) y(-1) CO(2) if used to substitute a coal fed power plant. Metal removal is very low for Cd and Pb but more significant for Zn with an annual reduction of 0.4-0.7 mgkg(-1) in the top soil layer.

Chemically assisted phytoextraction: a review of potential soil amendments for increasing plant uptake of heavy metals.

The contamination of soils by trace metals has been an unfortunate sideeffect of industrialization. Some of these contaminants can interfere with vulnerable enduses of soil, such as agriculture or nature, already at relatively low levels of contamination. Reversely, conventional civil-technical soil-remediation techniques are too expensive to remediate extended areas of moderately contaminated soil. Phytoextraction has been proposed as a more economic complementary approach to deal with this specific niche of soil contamination. However, phytoextraction has been shown to be a slow-working process due to the low amounts of metals that can be annually removed from the soil under normal agronomic conditions. Therefore, extensive research has been conducted on process optimization by means of chemically improving plant availability and the uptake of heavy metals. A wide range of potential amendments has been proposed in the literature, with considerable attention being spent on aminopolycarboxylic acids such as ethylenediaminetetraacetic acid (EDTA). However, these compounds have received increasing criticism due to their environmental persistence and associated risks for leaching. This review presents an overview of potential soil amendments that can be employed for enhancing metal uptake by phytoextraction crops, with a distinct focus on more degradable alternatives to persistent compounds such as EDTA.

Famciclovir for ophthalmic zoster: a randomised aciclovir controlled study.

AIMS: To compare the efficacy and safety of famciclovir with aciclovir for the treatment of ophthalmic zoster. METHODS: Randomised, double masked, aciclovir controlled, parallel group in 87 centres worldwide including 454 patients with ophthalmic zoster of trigeminal nerve (V(1)) comprised the intent to treat population. Oral famciclovir 500 mg three times daily or oral aciclovir 800 mg five times daily for 7 days. Assessments included day 0 (screening), days 3 and 7 (during treatment), days 10, 14, 21, 28 and monthly thereafter, up to 6 months (follow up). Proportion of patients who experienced ocular manifestations, severe manifestations and non-severe manifestations; loss of visual acuity was the main outcome measure. RESULTS: The percentage of patients who experienced one or more ocular manifestations was similar for famciclovir (142/245, 58.0%) and aciclovir (114/196, 58.2%) recipients, with no significant difference between groups (OR 0.99; 95% CI 0.68, 1.45). The percentage of patients who experienced severe and non-severe manifestations was similar between groups, with no significant difference. The prevalence of individual ocular manifestations was comparable between groups. There was no significant difference between groups for visual acuity loss. CONCLUSION: Famciclovir 500 mg three times daily was well tolerated and demonstrated efficacy similar to aciclovir 800 mg five times daily.

Acetazolamide affects performance on the Nagel II anomaloscope.

BACKGROUND: Recent reports have indicated that acetazolamide alters human electroretinograms. We wished to determine the effects of administering acetazolamide on performance on the Nagel II anomaloscope. METHODS: We tested 15 subjects matches of blue-green light to a mixture of blue and green lights (luminance match) on a Nagel type II anomaloscope 2.5 h after ingesting 500 mg of acetazolamide or a placebo. RESULTS: The mean of the luminance settings for the subjects was 54.4 for the placebo condition and 58.5 for the acetazolamide condition. The mean difference of 4.1 was statistically significant, indicating that following ingestion of acetazolamide subjects were less sensitive to a blue-green light. In two supplementary experiments we tested (1) a second group of four normal subjects using the Nagel type II anomaloscope and (2) the previously untreated eyes of four patients with primary open-angle glaucoma before and after placing them on acetazolamide therapy. In both groups, more blue-green light was needed to make the match after ingestion of acetazolamide. CONCLUSIONS: Acetazolamide alters the sensitivity of one or more cone populations, probably the carbonic anhydrase-containing cones. The sensitivity loss is reversible and does not appear to be clinically significant. However, the results suggest that patients administered acetazolamide should be excluded from studies which compare the color vision of glaucomatous patients to that of normals.

The effects of acetazolamide in albino rabbits, pigmented rabbits, and humans.

In three separate experiments albino rabbits, pigmented rabbits, and humans were tested following administration of acetazolamide and without acetazolamide. In all three experiments, we recorded electroretinograms (ERGs) under dark adapted and light adapted conditions and measured the b-wave amplitudes. Dark adapted ERG b-wave amplitudes were increased following administration of acetazolamide as compared to control conditions, in albino rabbits, pigmented rabbits and humans. Light adapted b-wave amplitudes showed no statistically significant changes as a function of acetazolamide administration although in all three experiments there was a trend toward light adapted b-wave amplitude reduction following administration of acetazolamide. In the human experiments, ERG a-wave amplitudes were also measured. Light adapted a-wave amplitudes were reduced following administration of acetazolamide. In the human experiments, several behavioral tests were performed, including L'Anthony desaturated D-15, Farnsworth-Munsell 100 hue, Cogan-Gunkel chromatograph, Nagel anomaloscope, Goldmann-Weekers dark adaptometry. There were no consistent changes in the human dark adaptation thresholds or color discrimination, although several measures approached significance.

How useful are scrapings in the treatment of corneal ulcers?

We retrospectively reviewed the records of patients, hospitalised in our department from january 1989 through january 1993, with the diagnosis of corneal ulcer. The medical records were analyzed and the information computed, with emphasis on the modalities of prelevation, and the response to treatment. Direct inoculation of scrapings on media and an initial treatment with a combination of fortified antibiotics have proven to be effective over the past several years.

Blindness following paranasal sinus surgery: a report of two cases.

Two cases of blindness following paranasal sinus surgery are presented. The first patient, a 38-year old man, developed a delayed massive haemorrhage, after bilateral sphenoethmoidectomy. This hemorrhage could be stopped by electric cauterisation under endoscopical control. During this reintervention the patient developed total blindness of his right eye, and a restriction of the inferotemporal left visual field. The second patient, a 10-year old girl, developed, after bilateral spheno-ethmoidectomy for isolated sphenoiditis, total blindness of the left eye and paralysis of the ipsilateral extraocular muscles. According to the literature, blindness secondary to paranasal surgery is mainly due to retrobulbar hemorrhage. In the first case blindness was due to a direct cauterisation of the optic nerve, after perforation of the lamina papyracea. In the second case, blindness was probably due to a hemorrhage in the orbital apex.

Acute macular neuroretinopathy after shock.

Acute macular neuroretinopathy is a rare disease that has been described mainly in women taking hormonal contraceptives. An association either with a viral illness or with the parenteral use of sympathomimetics was sometimes found. We describe its occurrence in a 22-year-old female following an anaphylactic shock after a bee sting, and in a 26-year-old female following a pregnancy complicated with vena cava syndrome and delivery by caesarean section. A combination of factors including hypoperfusion, Valsalva stress, estrogen-induced hematological and rheological changes, and alpha-adrenergic stimulation apparently provoked this clinical manifestation.