Enzyme-linked immunosorbent assay for the detection of circulating antigens of Toxoplasma gondii in the serum of cats

An ELISA was developed to detect circulating antigens of Toxoplasma gondii in the serum of cats. For the experiment, toxoplasmosis was induced in a group of cats by oral administration of bradyzoites. An ELISA that detects anti-Toxoplasma IgG, an ELISA to detect circulating antigens, and fecal examinations were performed on samples from each cat for 1 year after inoculation. When coupled with IgG-class antibody measurement, antigen detection can aid in the diagnosis of some cases of subclinical feline toxoplasmosis.     

Ionophores alter hepatic concentrations of intermediary carbohydrate metabolites in steers

The effects of ionophores on liver weight and function were determined in finishing steers (n = 24; avg weight 440 kg). Steers were group-fed one of three treatments (control, lasalocid or monensin at 33 mg/kg feed) for 46 d prior to slaughter. Three days prior to slaughter, blood was collected for the determination of serum Ca and Mg. At slaughter, the liver was removed, weighed, sampled, frozen in liquid nitrogen and subsequently analyzed for concentrations of carbohydrate metabolites and minerals. Liver weight (5.9 kg) was unaffected by treatment. Serum and hepatic Ca and Mg were not affected by ionophore treatment. Hepatic glycogen levels in steers fed ionophores were unaffected by treatment. Fructose 1,6-bisphosphate was 21% lower (P less than .10) in hepatic tissue of steers fed ionophores, whereas dihydroxyacetone phosphate was 15 to 37% greater in hepatic tissue of steers fed monensin (P less than .20) or lasalocid (P less than .10). Glyceraldehyde 3-phosphate was elevated more extensively by lasalocid than by monensin with increases of 72 (P less than .05) and 132% (P less than .001), respectively, over controls. Glycerol 3-phosphate levels were 37% (P less than .05) and 12% (NS) greater with these ionophores. Hepatic levels of pyruvate were elevated 12 (NS) to 36% (P less than .17) for monensin and lasalocid. Fructose 2,6-bisphosphate levels were 25% lower (P less than .25) in hepatic tissue of steers fed ionophores than in hepatic tissue from control steers. Other metabolites of carbohydrate metabolism in hepatic tissue were not altered appreciably. Changes in levels of intermediary metabolites of carbohydrate metabolism suggest alterations in hepatic carbohydrate metabolism favoring gluconeogenesis in steers fed ionophores.     

Effects of monensin on Mg, Ca, P and Zn metabolism and tissue concentrations in lambs

A study consisting of two trials was conducted to determine the effects of monensin on the apparent absorption and retention of magnesium (Mg), phosphorus (P), calcium (Ca) and zinc (Zn) and to determine mineral changes in tissue and ruminal fluid. Eight lambs (39 kg) were used in trial 1, and 10 lambs (37 kg) were used in trial 2. Animals were blocked by weight and fed a high concentrate diet with or without 20 mg/kg monensin. Trials began with a dietary adjustment period lasting 18 d in trial 1 and 21 d in trial 2. Animals were then placed in metabolism stalls for a 10-d stall adjustment period followed by a 12-d collection period. Collections to determine mineral balance were made during the first 10 d of the collection period. Blood and ruminal fluid samples were taken on d 11 of the collection period. Lambs were slaughtered on d 12 of the collection period and tissue samples were collected. Monensin supplementation increased (P less than .05) Mg retention 42.0%. Urinary Ca excretion decreased (P less than .05) 60.0% when monensin was fed. Monensin supplementation decreased (P less than .05) liver Ca and bone Ca, 45.5 and 2.9%, respectively. Apparent P digestibility increased (P less than .05) 40.0% and P retention increased (P less than .10) 26.8% due to monensin supplementation. Both apparent absorption and retention of Zn increased (P less than .01) 50.0 and 45.0%, respectively, with monensin supplementation. Ruminal fluid Zn concentrations decreased (P less than .05) 33.0% with the addition of monensin.(ABSTRACT TRUNCATED AT 250 WORDS)     

Coccidioidomycosis in 48 Cats: A Retrospective Study (1984–1993)

Coccidioidomycosis was diagnosed in 48 cats. Forty-one cases were identified within a period of 3 years. Coccidioides immitis was revealed by cytological or histopathological examinations, or culture in 70% of cats. The remaining 30% of cases were diagnosed by appropriate clinical signs, radiographic lesions, and serological test results. The average age of affected cats was 6.2 years with a median age of 5.0 years. Fifty-four percent (n = 26) were female and 46% (n = 22) were male. Domestic shorthaired and longhaired breeds comprised 89% (n = 41) of affected cats. Sixty-seven percent of cases were diagnosed during the 6-month period of December through May. Cats infected with C immitis were presented for evaluation of dermatologic (56%), respiratory (25%), musculoskeletal (19%), and neurological or ophthalmologic signs (19%). Fever, inappetence, and weight loss were present in 44% of the cats. Duration of clinical signs before diagnosis was less than 4 weeks in 85% (n = 42) of cats, with an average of 3.8 weeks and a median of 2 weeks. Agar gel immunodiffusion tests were positive in all 39 cats tested at sometime during the course of their disease. Hyperproteinemia (greater than 7.9 g/dL) was present in 52% (10/23) of cases. The majority of cats (n = 39) were negative for feline leukemia virus. Antibodies to feline immunodeficiency virus were absent in the 19 cats tested. Ketoconazole was the most common antifungal agent used to treat cats with Coccidioidomycosis. Duration of treatment ranged from less than 1 week to 43 months. Thirty-two cats are currently asymptomatic, with or without treatment. Eleven cats died or were euthanized. Five cats were lost to follow-up. Ketoconazole likely is more suppressive than curative because relapses were common after discontinuing therapy.     

A diet-induced developmental polymorphism in a caterpillar

Caterpillars of the spring brood of Nemoria arizonaria develop into mimics of the oak catkins upon which they feed. Caterpillars from the summer brood emerge after the catkins have fallen and they develop instead into mimics of oak twigs. This developmental polymorphism may be triggered by the concentration of defensive secondary compounds in the larval diet: all caterpillars raised on catkins, which are low in tannin, developed into catkin morphs; those raised on leaves, which are high in tannin, developed into twig morphs; most raised on artificial diets of catkins with elevated tannin concentrations developed into twig morphs.     

TILLING and Ecotilling the Plant Kingdom

The modem crop scientist has a large amount of available nucleotide sequence information to identify genes of potential agronomic importance. Using reverse genetic approaches, specific genes can be disrupted, and hypotheses regarding gene function directly tested in vivo. Although a number of reverse genetic methods have been introduced, many are limited in application because they are organism-specific, expensive, transgenic, or only transiently disrupt gene function. However, traditional mutagenesis using chemical mutagens has been widely used as a forward genetics strategy to create many new crop plant varieties at relatively low cost. Mutagens such as ethyl methanesulphonate （EMS） cause stable point mutations and thus produce an allelic series of truncation and missense changes that can provide a range of phenotypes （Greene et al., 2003）. TILLING （targeting induced local lesions IN genomes） is a high-throughput reverse genetic strategy that combines traditional mutagenesis and SNP discovery methods （Colbert et al., 2001; McCallum et al., 2000）. To identify mutations, target regions of-l.5 kb are amplified with fluorescently labeled gene specific primers. Heteroduplexes are then formed between wild-type and mutant strands, mismatches are cleaved by incubation with a single-strand specific nuclease,