Anesthetic effects of clove oil and lidocaine-HCl on marine medaka (Oryzias dancena)

Fish may be anesthetized for various experimental and practical purposes, primarily to immobilize them in order to facilitate handling. Marine medaka (Oryzias dancena) is a teleost fish used in marine ecotoxicology studies. Despite the importance of anesthesia in handling experimental fish, the effects of anesthesia in marine medaka have not yet been investigated. In this study, the authors evaluated the anesthetic effects (time required for anesthesia to take effect and recovery time) of two anesthetic agents, clove oil and lidocaine-HCl, on marine medaka. They anesthetized fish at different water temperatures (23 °C, 26 °C and 29 °C) and using different concentrations of clove oil (50 ppm, 75 ppm, 100 ppm, 125 ppm, 150 ppm and 175 ppm) or lidocaine-HCl (300 ppm, 400 ppm, 500 ppm, 600 ppm, 700 ppm and 800 ppm). The time required for anesthesia to take effect decreased significantly as both anesthetic concentration and water temperature increased for both clove oil and lidocaine-HCl. To anesthetize marine medaka within approximately 1 min, the optimal concentrations for clove oil were 125 ppm at 23 °C, 100 ppm at 26 °C and 75 ppm at 29 °C and for lidocaine-HCl were 800 ppm at 23 °C and 700 ppm at both 26 °C and 29 °C. The authors also compared anesthetic effects in marine medaka of different sizes. Both anesthetic exposure time and recovery time were significantly shorter for smaller fish than for larger fish. These results provide a useful foundation for the laboratory handling of marine medaka.     

Tolerance of wheat and pea to boron in irrigation water

In a micro-plot experiment 1.5 ppm boron in the irrigation water was toxic for wheat. Its concentration in the soil solution increased to 1.53 ppm and in the plant tissue to 58 ppm. In pea plants 4 ppm B in the irrigation water was toxic with 2.00 ppm soil solution B and 213 ppm tissue B. Nitrogen in both species increased significantly and calcium decreased with the increase in B in irrigation water. The yield of wheat grain declined by 13, 20 and 32 per cent at the 4.0, 6.0 and 8.0 ppm B respectively. The yield of straw and grains of pea declined by 31, 56 and 41, 56 per cent at 6.0 and 8.0 ppm B levels respectively. Thus tolerance to B in irrigation water was between 3.0 and 4.0 ppm for wheat and 4.0 and 6.0 ppm for pea.     

PHYTOTOXICITY OF FUNGICIDES AND BACTERICIDES IN ORCHID CULTURE MEDIA

A number of fungicides, bactericides and dual-action substances were screened for phytotoxicity in vitro using Cattleya aurantiaca and Stanhopea occulata (Orchidaceae) seedlings. Of the 25 compounds screened, ten (each at only one concentration) were employed in nine different combinations for nonsterile in vitro cultures of Cattleya aurantiaca seedlings: Amphotericin B, 10 ppm; Benlate, 50 ppm; Dowicide, 5 ppm; Ethirimol, 50 ppm; Gentamicin, 50 ppm; Nystatin, 25 ppm; PCNB, 100 ppm; Penicillin G, 100 ppm; Sodium omadine, 5 ppm; and Vancomycin, 50 ppm. All nine combinations prevented contamination, but had different effects on seedling development.     

Toxic levels of soil and plant zinc for maize and wheat

Summary Maize and wheat crops grown for 60 days and maturity respectively in soils with a range of available zinc (0.4 to 109 ppm DTPA extractable) indicated 7 ppm Zn in soil and 60 ppm in plant being toxic for wheat. These limits for maize were 11 ppm Zn in soil and 81 ppm Zn in plant. Wheat crop is more susceptible to Zn toxicity as compared to maize.     

Effects of temperature, and dietary magnesium and nickel levels on magnesium and nickel concentrations during the moult-cycle in Oniscus asellus (Porcellionidae, Isopoda, Crustacea).

Mean magnesium concentrations in intermoult Oniscus asellus, caged at 20 degrees C for 10 days, ranged from 1,059.15 +/- 51.9 ppm on diets containing 10 ppm nickel, to 6,827.6 +/- 314.1 ppm on a mixture of 500 ppm magnesium + 10 ppm nickel. Mean nickel concentrations ranged from 89.4 +/- 4.3 ppm on diets containing 500 ppm magnesium, to 314.0 +/- 14.8 ppm on a mixture of 500 ppm magnesium + 10 ppm nickel. At 30 degrees C, magnesium tissue concentrations ranged from 4,149.8 +/- 153.5 ppm on diets with 10 ppm nickel to 12,602.6 +/- 529.3 ppm on 500 ppm magnesium. Nickel concentrations at 30 degrees C varied from 156.8 +/- 6.7 in isopods in the control to 490.5 +/- 23.5 ppm on those on 500 ppm magnesium + 10 ppm nickel. Magnesium in intermoult isopods was mainly stored in other tissues, including the exoskeleton, and nickel in the hepatopancreas. Differences in both magnesium and nickel concentrations between males and females were not significant. Magnesium and nickel concentrations in postmoult isopods, on the average, amounted to 367.6 +/- 16.5 ppm and 18.7 +/- 0.7 ppm, respectively, at 20 degrees C, and 369.9 +/- 16.3 ppm and 30.9 +/- 1.3 ppm, respectively, at 30 degrees C. Differences between males and females, and between various treatments were not significant at P greater than 0.01. It is suggested that both hepatopancreas and other tissues, including the exoskeleton, are used as sinks to get rid of excessive tissue magnesium and nickel during the moult-cycle.     

Lead exposure in an "urban" peregrine falcon and its avian prey

Necropsy of a 7-yr-resident peregrine falcon (Falco peregrinis) from Baltimore showed a Pseudomonas infection involving the pharynx as the immediate cause of death. Concentrations of lead in liver and kidney measured 0.74 and 1.40 ppm, respectively. A survey of lead exposure was performed on 40 urban rock doves (Columbia livia). Thirteen additional rock doves were collected from sites removed from lead contamination and served as controls. The mean concentration of lead in the blood of the urban rock doves was 0.96 ppm (range 0.29-17.0 ppm) compared to 0.05 ppm (0.01-0.07 ppm) for control birds. Ninety-eight percent (39/40) of the urban rock doves had elevated concentrations of lead in their blood, while 27% (11/40) had sublethal concentrations. None of the control birds had increased concentrations of lead in their blood. Concentrations of lead in liver and kidney of 13 urban rock doves were 3.48 ppm and 9.53 ppm, respectively, compared to concentrations of 0.43 ppm and 0.50 ppm for four control rock doves. From these data a mean total concentration of lead per rock dove was calculated at 4.60 ppm for urban birds and 0.33 ppm for control birds.     

Toxicity of two carbamate insecticides to the cyanobacterium Anabaena PCC 7120 and computations of partial lethal concentrations by the probit method

Toxicity studies of two commercial carbamate insecticides, carbaryl and carbofuran with the nitrogen-fixing filamentous cyanobacterium Anabaena PCC 7120, are described. Under nitrogen-fixing conditions and with calcium nitrate supplementation, 100 and 120 ppm carbaryl were the respective lethal concentrations (LC100), while 20 to 80 ppm (nitrogen-fixing conditions) and 20 to 100 ppm (with nitrate supplementation) were the partial lethal doses (相似文献   

Sublethal effects of heavy metal contaminated sediment on midge larvae (Chironomus tentans)

Chironomid larvae were maintained for 17 days in sediments with various heavy metal levels. The control sediment had levels of 0.6 ppm cadmium, 17 ppm chromium and 77 ppm zinc. The most contaminated sediment had levels of 1030 ppm cadmium, 1640 ppm chromium, and 17300 ppm zinc.The mean length and weight of the larvae from the control sediment were 1.83 cm and 2.86 mg. The mean length and weight of larvae from the most contaminated sediment were 0.82 cm and 0.20 mg. A linear relationship was found for the square root of length versus metal levels in the sediment.     

Somatic embryogenesis and plant regeneration from the anther of Aconitum carmichaeli Debx

Anthers of Aconitum carmichaeli Debx. were used for callus induction. After the addition of 5 ppm 2,4-D and 1 ppm kinetin callus induction occurred over a period of 15 weeks. When calluses were subcultured on a medium containing 1 ppm 2,4-D for 12 weeks embryogenesis occurred. Mature somatic embryos developed normal shoots when transferred to basal medium inoculated with 1 ppm GA and 5 ppm BAP. Rooting occurred after the transfer of shoots to a new medium containing 0.5 ppm IAA and plantlets formed. The transplantation of these was successful and all plants matured during 5 months subsequent cultivation.     

Genotoxicity of intermittent co-exposure to benzene and toluene in male CD-1 mice

Benzene is an important industrial chemical. At certain levels, benzene has been found to produce aplastic anemia, pancytopenia, myeloblastic anemia and genotoxic effects in humans. Metabolism by cytochrome P450 monooxygenases and myeloperoxidase to hydroquinone, phenol, and other metabolites contributes to benzene toxicity. Other xenobiotic substrates for cytochrome P450 can alter benzene metabolism. At high concentrations, toluene has been shown to inhibit benzene metabolism and benzene-induced toxicities. The present study investigated the genotoxicity of exposure to benzene and toluene at lower and intermittent co-exposures. Mice were exposed via whole-body inhalation for 6h/day for 8 days (over a 15-day time period) to air, 50 ppm benzene, 100 ppm toluene, 50 ppm benzene and 50 ppm toluene, or 50 ppm benzene and 100 ppm toluene. Mice exposed to 50 ppm benzene exhibited an increased frequency (2.4-fold) of micronucleated polychromatic erythrocytes (PCE) and increased levels of urinary metabolites (t,t-muconic acid, hydroquinone, and s-phenylmercapturic acid) vs. air-exposed controls. Benzene co-exposure with 100 ppm toluene resulted in similar urinary metabolite levels but a 3.7-fold increase in frequency of micronucleated PCE. Benzene co-exposure with 50 ppm toluene resulted in a similar elevation of micronuclei frequency as with 100 ppm toluene which did not differ significantly from 50 ppm benzene exposure alone. Both co-exposures - 50 ppm benzene with 50 or 100 ppm toluene - resulted in significantly elevated CYP2E1 activities that did not occur following benzene or toluene exposure alone. Whole blood glutathione (GSH) levels were similarly decreased following exposure to 50 ppm benzene and/or 100 ppm toluene, while co-exposure to 50 ppm benzene and 100 ppm toluene significantly decreased GSSG levels and increased the GSH/GSSG ratio. The higher frequency of micronucleated PCE following benzene and toluene co-exposure when compared with mice exposed to benzene or toluene alone suggests that, at the doses used in this study, toluene can enhance benzene-induced clastogenic or aneugenic bone marrow injury. These findings exemplify the importance of studying the effects of binary chemical interactions in animals exposed to lower exposure concentrations of benzene and toluene on benzene metabolism and clastogenicity. The relevance of these data on interactions for humans exposed at low benzene concentrations can be best assessed only when the mechanism of interaction is understood at a quantitative level and incorporated within a biologically based modeling framework.     

The molluscicidal activity of plants used in Brazilian folk medicine.

In a continuing search for new compounds for the control of the vectors of schistosomiasis, we have tested the activity of some Brazilian medicinal plants as sources of molluscicidal natural compounds, using two molluscicidal bioassays. Twenty-seven crude extracts, from twenty-six species belonging to nineteen families, were tested. Seven extracts showed significant molluscicidal activity against Biomphalaria glabrata adults with DL50 values of less than 50 ppm, and five of them were very active in the test using egg masses. The species most active against B. glabrata adults (LD50 value = 3.65 ppm) and their egg masses (LD50 value = 0.13 ppm) was Derris sp. Annona muricata [LD50 value (adult) = 11.86 ppm and LD50 value (egg) = 49.62 ppm], Jatropha elliptica (from Goiás state) [LD50 value (adult) = 24.80 ppm and LD50 value (egg) = 3.03 ppm] and Renealmia exaltata [LD50 value (adult) = 28.03 ppm and LD50 value (egg) = 21.67 ppm], were also considered promising molluscicidal plants.     

Natural occurrence of deoxynivalenol, 15-acetyl-deoxynivalenol, and zearalenone in refusal factor corn stored since 1972.

Two samples of "refusal factor" corn, one stored frozen in Minnesota and one stored dry in Indiana since 1972 or 1973, were analyzed for the presence of Fusarium spp. and Fusarium toxins. Both samples were from corn refused by swine in Indiana from 1972 to 1973. Sample FS 808 (stored in Indiana) contained 20 ppm of deoxynivalenol (20 micrograms/g), 16 ppm of 15-acetyl-deoxynivalenol, 5 ppm of zearalenone, and 0.2 ppm of alpha-zearalenol. Sample FS 362 (stored in Minnesota) contained 3 ppm of deoxynivalenol, 1 ppm of 15-acetyldeoxynivalenol, and 0.3 ppm of zearalenone. The presence of 15-acetyl-deoxynivalenol is significant because it is the first report of it occurring naturally in refusal factor corn, and it may account in part for the refusal that could not be solely attributed to deoxynivalenol.     

Natural occurrence of deoxynivalenol, 15-acetyl-deoxynivalenol, and zearalenone in refusal factor corn stored since 1972

Two samples of "refusal factor" corn, one stored frozen in Minnesota and one stored dry in Indiana since 1972 or 1973, were analyzed for the presence of Fusarium spp. and Fusarium toxins. Both samples were from corn refused by swine in Indiana from 1972 to 1973. Sample FS 808 (stored in Indiana) contained 20 ppm of deoxynivalenol (20 micrograms/g), 16 ppm of 15-acetyl-deoxynivalenol, 5 ppm of zearalenone, and 0.2 ppm of alpha-zearalenol. Sample FS 362 (stored in Minnesota) contained 3 ppm of deoxynivalenol, 1 ppm of 15-acetyldeoxynivalenol, and 0.3 ppm of zearalenone. The presence of 15-acetyl-deoxynivalenol is significant because it is the first report of it occurring naturally in refusal factor corn, and it may account in part for the refusal that could not be solely attributed to deoxynivalenol.     

Genetic differences in phosphorus absorption among white clover populations

Summary Eight semi-natural white clover populations and two cultivars were grown in culture solutions containing 10 ppm and 0.01 ppm phosphorus (P). The rate of P uptake by the intact plants was then measured in solutions containing 10 ppm P.Phosphorus uptake per unit root length was twice as great by plants previously grown at 0.01 ppm P than those grown at 10 ppm P. Large differences in total P uptake were found among populations regardless of the pretreatment; most of this variation was accounted for by differences in root length. Only small differences were found between populations for P uptake per unit root length, and then only after pretreatment with 10 ppm P; this variation was largely accounted for by relative growth rate and shoot %P.     

Effects of oligosaccharins on callus growth and saponin content of Panax notoginseng

This work provides some evidences for the saponinproduction of Panax notoginseng callus by using biologi-cally active,wall-related oligosaccharins.In anappropriate concentration,three kinds of oligosaccharinsstimulated saponin formation or callus growth.Theconcentration of DO,GO and CO for saponin productionof Panax notoginseng callus culture were 15ppm,15ppmaud 20ppm respectively by comparing saponin yield.Itwas very obvious for DO to increase saponin contentwhen the concentration was 10ppm,and for GO tostimulate callus growth when the concentration was20ppm.It would be a good way to produce saponin byusing oligosaccharins in large scale culture in thefuture.     

Developmental toxicity studies in Crl:CD (SD) rats following inhalation exposure to trichloroethylene and perchloroethylene

The potential for trichloroethylene (TCE) and perchloroethylene (PERC) to induce developmental toxicity was investigated in Crl:CD (SD) rats whole-body exposed to target concentrations of 0, 50, 150 or 600 ppm TCE or 0, 75, 250 or 600 ppm PERC for six hours/day, seven days/week on gestation day (GD) 6-20 and 6-19, respectively. Actual chamber concentrations were essentially identical to target with the exception of the low PERC exposure level, which was 65 ppm. The highest exposure levels exceeded the limit concentration (2 mg/L) specified in the applicable test guidelines. Maternal necropsies were performed the day following the last exposure. Dams exposed to 600 ppm TCE exhibited maternal toxicity, as evidenced by decreased body weight gain (22% less than control) during GD 6-9. There were no maternal effects at 50 or 150 ppm TCE and no indications of developmental toxicity (including heart defects or other terata) at any exposure level tested. Therefore, the TCE NOEC for maternal toxicity was 150 ppm, whereas the embryo/fetal NOEC was 600 ppm. Maternal responses to PERC were limited to slight, but statistically significant reductions in body weight gain and feed consumption during the first 3 days of exposure to 600 ppm, resulting in a maternal NOEC of 250 ppm. Developmental effects at 600 ppm consisted of reduced gravid uterus, placental and fetal body weights, and decreased ossification of thoracic vertebral centra. Developmental effects at 250 ppm were of minimal toxicological significance, being limited to minor decreases in fetal and placental weight. There were no developmental effects at 65 ppm.     

Magnesium and manganese uptake, accumulation and regulation by a terrestrial isopod, Porcellio spinicornis Say (Porcellionidae, isopoda, Crustacea)

Highest Mg concentration in whole intermoult, 7th growth-stage Porcellio spinicornis, exposed for 7 days to various Mg [367.39 ppb (carrot powder-control), 217.6 ppb (apple powder-control), 100, 150, 500, and 1000 ppm Mg, as well as two mixtures containing 500 ppm Mn + 150 ppm Mg and 500 ppm Mg + 500 ppm Mn)], and Mn concentrations [97.9 ppb (carrot powder-control), 2.0 ppb (apple powder-control), 100, 150, 500 and 1000 ppm)], was observed in males feeding on 500 ppm Mn + 150 ppm Mg, and lowest in females on 500 ppm dietary Mg. Highest tissue Mn concentration, on the other hand, was observed in males exposed to 1000 ppm dietary Mn, and lowest in females on 500 ppm Mg. Approximately 42% of the total tissue Mg was present in hepatopancreas and the remaining in other body tissues, including exoskeleton. In contrast, 78.55% Mn was stored in hepatopancreas and 21.4% in remaining body tissues. Differences between hepatopancreatic Mg levels were not significant between the two sexes, but differences in Mn levels between males and females were significant at P less than 0.01.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of Selected Chemical Pesticides on Agamermis unka (Nematoda: Mermithidae), a Parasite of the Brown Plant Hopper,Nilaparvata lugens

Selected commercial and technical grade pesticides were tested against the egg, preparasite and adult stages of Agamermis unka , a nematode parasite of the brown planthopper, Nilaparvata lugens . The commercial insecticide, diazinon (LC = 0.37 ppm), was most toxic to the 50 preparasites, followed by phenthoate (LC = 0.43 ppm), BPMC (LC = 0.44 ppm), IBP 50 50 (LC = 0.46 ppm), cartap hydrochloride (LC = 0.82 ppm) and buprofezin + isoprocarb 50 50 (LC = 1.11 ppm). The least toxic commercial pesticide tested was the fungicide, pencycuron 50 (LC = 2.19 ppm). Out of 12 technical grade insecticides tested, phenthoate, monocrotophos, 50 diazinon and carbofuran (LC = 0.37-0.46 ppm) were highly toxic to the preparasites, followed by 50 buprofezin, BPMC and fenitrothion (LC = 0.74-0.86 ppm). Fenthion, etofenprox, chlorpyrifos, 50 imidacloprid and MIPC (LC = 1.11-2.19 ppm) were the technical grade insecticides least toxic 50 to the preparasites. Most preparasites survived for up to 24 h at the low insecticide concentrations (0.63 and 0.31 ppm). Preparasites that were exposed to BPMC for 24 h at concentrations as high as 5.0 ppm and survived the treatments infected brown planthopper nymphs. Four selected insecticides-chlorpyrifos, BPMC, imidacloprid and carbofuran-had significant adverse effects on A. unka egg hatching. Eggs that were in the insecticide solution for 168 h fared poorly with imidacloprid having the best survival ( > 2% of the eggs hatching at 0.04 ppm). No eggs hatched from the other insecticide treatments. Three selected insecticides, BPMC, imidacloprid and chlorpyrifos, tested against adult A. unka showed that most adults survived the exposure to the insecticides between 0.31 and 2.5 ppm. At 5.0 ppm of BPMC or chlorpyrifos none of the adults survived, whereas with imidacloprid 70% of the adults survived. Egg deposition by the surviving adults was greatly reduced in those treated with the insecticides compared with those in the controls. Imidacloprid had some negative impact on the preparasites' ability to infect BPH nymphs, but it had the least detrimental effect of the insecticides tested on preparasite survival and on the eggs and adults of A. unka .     

Caffeine Formulation for Avian Repellency

Abstract: Nonlethal management alternatives are needed to reduce avian depredation of agricultural crops. Caffeine has promise as an effective, economical, and environmentally safe avian repellent, yet formulation improvements are needed for field applications. We included sodium benzoate in subsequent formulations to enhance the solubility of caffeine. Red-winged blackbirds (Agelaius phoeniceus) discriminated between untreated rice and rice treated with 250 ppm or 10,000 ppm caffeine and sodium benzoate in captivity. We observed a positive concentration-response relationship among birds offered rice treated with 250 ppm, 1,000 ppm, 2,500 ppm, 5,000 ppm, 10,000 ppm, or 20,000 ppm caffeine and sodium benzoate. Relative to the pretreatment of the concentration-response test, repellency was >85% for rice treated with our 2,500- to 20,000-ppm treatments. We conducted seed germination experiments and associated residue analyses to evaluate the potential phytotoxicity of various caffeine formulations under controlled environmental conditions. The optimized formulation enhanced the solubility of tank mixtures and ameliorated the negative impacts of seed treatments to germination. Our caffeine formulation provides an applicable, nonlethal alternative for managing blackbird impacts to agricultural production.     

Carbaryl-induced behavioural and reproductive abnormalities in the earthworm Metaphire posthuma: a sensitive model

Carbaryl, an N-methyl carbamate insecticide, is used in India to control foliar insects, but, due to soil contamination, it also adversely affects non-target organisms such as earthworms. This paper deals with the toxic effects of carbaryl on the behavioural and reproductive profiles of the earthworm, Metaphire posthuma. Locomotion and geotaxis were significantly affected, even after a 20-minute exposure to 0.125ppm carbaryl. The hatching of cocoons was altered at 0.5ppm, whereas cocoon production was retarded even at 0.125ppm carbaryl. No cocoon production was observed at 2.0ppm carbaryl. Sperm head abnormalities were reported even at the lowest test concentration of 0.125ppm. Wavy head abnormalities were observed at 0.125ppm carbaryl, whereas at 0.25ppm and 0.5ppm, the sperm heads became amorphous and the head nucleus was turned into granules deposited within the wavy head. It is concluded that the earthworm could be used as an ecosystem model for the initial toxicity testing of environmental pollutants.