Central nervous system toxicosis associated with metronidazole treatment of dogs: five cases (1984-1987)

Metronidazole, administered to 5 dogs for periods ranging from 3 to 14 days, was associated with acute development of CNS dysfunction. Metronidazole dosage ranged from 67.3 to 129.0 mg/kg of body weight/d. Clinical signs of toxicosis began with anorexia and intermittent vomiting and progressed rapidly to include pronounced, generalized ataxia and vertical, positional nystagmus. These signs were consistent with lesions of the vestibular nuclei and/or cerebellum. High CSF protein content was detected in 2 of 3 dogs from which CSF was collected. Two dogs were euthanatized because of severe neurologic dysfunction. Three dogs improved slowly and recovered completely over several months. These findings suggest that currently recommended dosages of metronidazole may be too high for some dogs.     

Dose–Response Studies for Pituitary and Testicular Function in Male Dogs Treated with the GnRH Superagonist, Deslorelin

We tested the effect of dose of GnRH superagonist on pituitary and testicular function in a study with four groups of four male dogs. The Controls received blank implants and the other three groups received implants containing 3, 6 or 12 mg deslorelin (d ‐Trp⁶‐Pro⁹‐des‐Gly¹⁰‐GnRH ethylamide). In all deslorelin‐treated groups, there was initially an acute increase in plasma concentrations of LH and testosterone, followed by declines such that both hormones became undetectable after approximately 12 days. There was a dose–response in some of these early aspects of the hormone profiles. With respect to long‐term effects of treatment, the 12‐mg dose had significantly greater effects than the smaller doses for the duration of minimum testicular volume [366 ± 77, mean ± SEM (3 mg), 472 ± 74 (6 mg), and 634 ± 59 (12 mg) days], absence of ejaculate [416 ± 88 (3 mg), 476 ± 83 (6 mg), and 644 ± 67 (12 mg) days], undetectable plasma concentrations of LH and testosterone [367 ± 64 (3 mg), 419 ± 72 (6 mg), and 607 ± 69 (12 mg) days], the delay until complete recovery of LH and testosterone secretion [394 ± 65 (3 mg), 484 ± 72 (6 mg) and 668 ± 47 (12 mg) days], and the delay until testes had regrown to normal volume [408 ± 77 (3 mg), 514 ± 74 (6 mg), 676 ± 59 (12 mg) days]. The time taken to restore full ejaculates was also longest for the 12‐mg dose: 716 ± 67 (12 mg) days vs 440 ± 66 (3 mg) and 538 ± 83 (6 mg) days after implantation. There was no correlation between delay to recovery of normal ejaculate quality and body mass. We conclude that the dose–response relationship with deslorelin implants is not expressed with respect to the degree of suppression of reproduction, but on the maximum duration of suppression and thus to delay until recovery.     

Sorption/desorption behaviour of sulfonylurea herbicides as affected by the addition of fresh and composted olive cake to soil

The olive industry generates residues which can be applied as amendments to soils in their original form (olive cake) or after composting or vermicomposting processes. The addition, fresh or incubated, of these amendments to soil and of their different organic fractions was studied in relation to the sorption/desorption of three sulfonylurea herbicides, bensulfuron‐methyl, chlorsulfuron and prosulfuron. Herbicide sorption was low or very low, slightly promoted by the addition of the agricultural by‐products, especially olive cake, and mainly affected by pH of the soil solution, with the organic carbon content having no significant effect on herbicide retention. Desorption was only reduced when fresh olive cake was added. The incubation of soil and amendments for 3 months did not modify herbicide sorption, but made desorption reversible except for olive cake. The transformation of the organic matter of the amendments due to humification and maturity processes are likely to be responsible for this behaviour. Different organic fractions were removed to assess the influence of each fraction on sulfonylurea sorption. Only the removal of all studied organic fractions increased herbicide sorption, revealing the role of humin and mineral fractions in this process. Therefore, the use of organic amendments is not useful for reducing the risk of movement of ionisable molecules in soil.     

N Response of No-Till Dryland Winter Triticale Forage

Triticale’s forage-yield response to fertilizer nitrogen (N) is impressive on soils testing low in available N. Our objectives were to (1) quantify the forage-yield response of dryland winter triticale to applied N and residual nitrate N and (2) fit the yield data to a regression equation based on both applied N and residual soil nitrates and use the fitted equation to calculate economic optimum N rates for this crop (EONR). Winter triticale was direct seeded no-till into wheat or millet stubble for four site years at the United States Department of Agriculture, Agricultural Research Service (USDA-ARS) Central Great Plains Research Station. In each experiment (1995, 2007, 2009 and 2010) just prior to planting, the soil was sampled for nitrate-N. Replicated field plots were top-dressed with 0, 22, 34, 67, 90, 101 or 135 kg of N fertilizer per ha as urea-N. Yield and total biomass N was then measured in each plot in late spring each year. A relative yield N response equation, fitted to all four years of data, was able to explain 93% of the variability in yield. That equation provided reasonable EONR estimates that matched 87% of the EONRs calculated for individual years.     

FeLV-FAIDS-induced immunodeficiency syndrome in cats

Findings are reviewed, relevant to elucidation of the pathogenic, genetic and biochemical properties of a single, genetically heterogeneous isolate of feline leukemia virus (FeLV-FAIDS) shown to induce fatal immunodeficiency disease in nearly 100% of inoculated cats. Hypotheses are suggested which pertain to the mechanism of T-cell killing by this virus, and which extrapolate findings in the FeLV-FAIDS animal model to AIDS induced in humans by human immunodeficiency virus (HIV).     

Long-term agroecosystem experiments: assessing agricultural sustainability and global change

Long-term agroecosystem experiments can be defined as large-scale field experiments more than 20 years old that study crop production, nutrient cycling, and environmental impacts of agriculture. They provide a resource for evaluating biological, biogeochemical, and environmental dimensions of agricultural sustainability; for predicting future global changes; and for validating model competence and performance. A systematic assessment is needed to determine the merits of all known experiments and to identify any that may exist in tropical and subtropical environments. The establishment of an international network to coordinate data collection and link sites would facilitate more precise prediction of agroecosystem sustainability and future global change.     

楚源果业优质鲜食猕猴桃产业化开发的实践与体会

“楚源果业”（长沙楚源果业有限公司的简称）从2003年起开始实施湖南省优质鲜食猕猴桃产业化工程。公司按照产业化经营的思路和集中成片、规模发展的原则，选择丰悦、翠玉等优良品种，在省内旅游区周边交通便利、农业生产管理水平较高的中低海拔地区建立生产基地，并以公司为龙头，按行业协作组织的形式将各生产基地组织起来，统一技术管理和果品营销。现已建立产业化基地约200hm^2，并在湘中、湘北、湘西北及湘西建立了鲜食猕猴桃重点示范基地。两年来，湖南省优质鲜食猕猴桃产业化开发从无到有，从小到大，极大地促进了湖南省猕猴桃产业的整体发展。     

RESPONSE OF LISIANTHUS TO IRRIGATION WITH SALINE WATER: ION RELATIONS

Eustoma grandiflorum (Raf.) Shinn. (lisianthus) is a moderately salt tolerant species that can be produced commercially under irrigation with saline wastewaters prevalent in two salt-affected areas of California. The objective of the present studies was to determine the effect of irrigation with saline waters of two different compositions on the ion accumulation and ion relations of lisianthus ‘Pure White’ and ‘Echo Blue’. The ionic composition of irrigation waters simulated the compositions typical of i) seawater dilutions (SWD) and ii) concentrations of Colorado River water (CCRW). Electrical conductivities (EC) of SWD and CCRW were between 2 and 12 dS · m^?1. Plants irrigated with CCRW were higher in Ca²⁺ compared to plants irrigated with SWD water. Calcium was also higher in ‘Pure White’ than in ‘Echo Blue’. Increasing EC of irrigation water caused a significant decrease in shoot and leaf Ca²⁺ concentration in ‘Echo Blue’, but had no effect on Ca²⁺ content of ‘Pure White’ shoots and leaves. Magnesium concentration in ‘Echo Blue’ was higher than in ‘Pure White’. Electrical conductivity did not significantly affect Mg²⁺ concentration of either cultivar, despite the increasingly higher external concentration. Potassium concentration of young and mature leaves of ‘Echo Blue’ increased as EC increased from 2 to 8 dS · m^?1, then decreased significantly once EC exceeded 8 dS · m^?1. Potassium concentration of ‘Pure White’ leaves decreased over the range of salinity treatments tested, suggesting that the reduced potassium ion (K⁺) activity at EC levels of 8 dS · m^?1, or less, that resulted in lower leaf?K⁺ in ‘Pure White’ did not cause a decrease in K⁺ uptake in ‘Echo Blue’. Increases in external Na⁺ caused a significant increase in Na⁺ in ‘Pure White’ leaves and these plants exhibited the best growth even when levels of Na⁺ were high enough to be considered detrimental for growth.