Experimental inoculation of European starlings (Sturnus vulgaris) and American crows (Corvus brachyrhynchos) with Mycobacterium bovis

The purpose of this series of pilot studies was to determine whether the passerine species studied are susceptible to infection with Mycobacterium bovis. Separate experiments were conducted on wild-caught starlings (Sturnus vulgaris) and American crows (Corvus brachyrhynchos). In each experiment, four birds were challenged intraperitoneally and four were challenged orally with microorganisms. Challenge dose was 1 x 10(5) colony-forming units of M. bovis cultured from a white-tailed deer (Odocoileus virginianus) case in Michigan. Birds were euthanatized at 1 and 2 mo postinoculation. Histologic lesions suggestive of mycobacteriosis, without the presence of acid-fast bacilli, were noted in all experimental groups. Mycobacterial cultures performed on pooled tissue samples were positive for M. bovis in only some of the intraperitoneal inoculates of each species.     

Effect of short-term feed restriction and calorie source on hormonal and metabolic responses in geldings receiving a small meal

The metabolic effects of short-term feed restriction and dietary calorie source were studied in horses receiving high-roughage or high-concentrate diets. Four Thoroughbred geldings were assigned to four treatment groups in a 4 x 4 Latin square experiment. The four treatments were 1) a nutritionally adequate high-roughage ration (70% roughage, 30% concentrate; AHR), 2) a nutritionally adequate high-concentrate ration (40% roughage, 60% concentrate; AHC), 3) 70% of the intake of the AHR diet (RHR), and 4) 70% of the intake of the AHC diet (RHC). Diets AHR and AHC were designed to meet the caloric need of horses undergoing moderately intense work. Blood samples were taken on the first 7 d of each period for analysis of serum T4 and T3 concentrations. On d 9 of each feeding period, each horse was fed 1.0 kg of oats as the morning meal. Jugular blood was sampled before and immediately after, as well as at 30 min after, completion of the meal and subsequently every hour for 7 h. Daily serum T4 and T3 concentrations were not affected by day, feeding level, or diet composition. Meal feeding produced an increase (P < 0.01) in T4 and T3 concentrations when horses were adapted to the AHR and AHC diets but not the RHR or RHC diets. Thyroxine concentrations were lowest (P < 0.05) when horses were adapted to the AHC diet. Glucose (P < 0.05), insulin (P < 0.01), and NEFA (P < 0.01) concentrations were higher in response to the meal when horses received RHR than for the other diets. These results indicate that nutrient restriction alters responses to meal feeding in horses and that this response may also be affected by the dietary roughage:concentrate ratio.     

First Description of Scrotal Testicles in a Dog Affected by 78, XX Testicular Disorder of Sex Development

An eight‐month‐old female dog presented with ambiguous external genitalia. A thorough clinical examination together with various imaging techniques and a histology examination showed the presence of two testicles linked to both the Mullerian and Wolffian ducts. The discovery of the 78,XX SRY‐negative karyotype led to the diagnosis of incoherence between the chromosomal and gonadal sex, which is typical for a 78,XX testicular disorder of sex development. Our case was unique because the testicles were still located in their normal scrotal position, whereas the literature contains reports of the presence of cryptorchid testicles in this karyotype setting. To our knowledge, this is the first case that describes an SRY‐negative 78,XX testicular disorder of sex development with bilateral scrotal testicles.     

Biogenic amine metabolites in cerebrospinal fluid of depressed and manic patients

A reduction in 5-hydroxyindoleacetic acid in cerebrospinal fluid was found in depressed and manic patients both while they were symptomatic and also after treatment. The concentration of homovanillic acid was initially reduced and then tended to increase after treatment.     

Amino-acid metabolism in forest soil—Isolation and turnover of organic matter covalently labelled with s-methionine

Organic matter was extracted with pyrophosphate-NaOH buffer, pH 8.0 from the 02 horizon of a hardwood forest and exposed to ¹⁵S-methionine for 18 h to allow the incorporation of the aminoacid into the extract. Compared with other amendments, supplementation of the incorporation medium with Na₂SO₄ yielded the highest recoveries of the labelled organic matter. This material was chemically recalcitrant, requiring treatment for 6 h at 121°C with 6 NaOH for complete release of the incorporated methionine. A and B horizon soils from several forests were exposed to labelled material following dialysis to remove unlabelled components and a minor ³⁵S-labeIled component. All samples began to release ³⁵S-methionine after 48 h. Further metabolism of this amino-acid included mineralization and conversion to cysteine. A portion of the sulfate-S generated from mineralization was incorporated into organic matter and was recovered only by acid and alkali extraction. ³⁵S-labelled methionine and cysteine were also found in these latter fractions, indicating that these amino-acids had been directly incorporated into organic material during exposure.     

Mineralization of methionine sulphur in soils and forest floor layers

A1-horizon soils and 01, 02 forest floor layers from a mixed mature hardwood forest rapidly converted methionine-S to readily-available (salt-extractable) and less readily-available (acid- and base-extractable) inorganic sulphate (SO^?2₄). It is suggested that this latter conversion represents the incorporation into organic matter of a portion of the (SO^?2₄) released by mineralization. On a dry weight basis, the 02 layer of the forest floor was the most active with respect to both conversions. Moreover, capacities for mineralization and (SO^?2₄) incorporation decreased with increasing sample depth within the mineral horizon. Both conversions were dependent upon temperature and duration of incubation and were absent from samples which had been autoclaved. Sodium azide and the broad-spectrum antibiotic, tetracycline also inhibited each conversion to varying extents depending upon the type of sample incubated with methionine.     

Sulfonate S: A major form of forest soil organic sulfur

Summary Several forests of varying elevations, soils and vegetation were studied to evaluate the relative importance of sulfonate S, amino acid S, and ester sulfate as constituents of soil organic S. Suflonate S exceeded 40% of total S in the O1 horizon of all but one site examined, and comprised at least 50% of total S in the O2 horizons of 14 out of 18 study sites examined. Sulfonate pool sizes, on a percentage basis, tended to decrease with increasing sample depth within the mineral horizons, but sulfonate S was still a major form of organic S in the C horizon. Amino-acid S pool sizes were, as a general rule, lower than those for sulfonate in the O1 and O2 horizons, and lower than those for both ester sulfate and sulfonate when mineral soil horizons were considered. In no case did amino-acid S represent>25% of total S. Amino-acid S decreased with increasing depth at all but one site examined. Ester sulfate pool sizes were generally less than those of sulfonate S and greater than those of amino-acid S. This trend was observed with the O1, O2, and A horizons, but it was not apparent with samples from the intermediate and lowest soil horizons, where ester sulfate levels exceeded those for sulfonate S in 4 out of 8 and 5 out of 14 sites, respectively, in these latter horizons. Although there were some exceptions, collectively, the data suggest that sulfonate S is a major form of organic S in forest soils, irrespective of depth.     

Enzyme-linked immunosorbent assay for the detection of yessotoxin and its analogues

Polyclonal antibodies were produced for the development of competitive enzyme-linked immunoassays for use in quantifying yessotoxins in shellfish, algal cells, and culture supernatants. Immunizing and plate coating antigens were prepared by derivatization of yessotoxin either by ozonolysis or bromination and conjugation to proteins. Two assays that were the most sensitive for yessotoxin were optimized and characterized. Cross-reactivity studies indicated that the antibodies raised have broad specificity and that binding to analogues was strongly affected by changes to the A-ring and, to a lesser extent, the K-ring regions of the toxin molecule. ELISA provides a sensitive and rapid analytical method that is suitable for screening large numbers of samples and detects all the yessotoxin analogues that the European Commission currently requires shellfish to be tested for. The assay limit of quantitation for yessotoxin in whole shellfish flesh is 75 microg/kg; therefore, assay sensitivity is sufficient to measure toxin levels well below the maximum permitted level set by the European Commission. The antibodies produced can be used in additional applications such as the immunolocalization of yessotoxins in shellfish and preparation of immunoaffinity columns.