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Biomedical subjects

J Stiller

Publications and source records attributed to J Stiller.

15 recordsLinked to original sources

The maize transposable element Ac is mobile in the legume Lotus japonicus.

To evaluate the prospects for transposon mutagenesis in the autogamous diploid legume Lotus japonicus, the behaviour of the maize transposable element Ac was analysed in the progeny of 38 independent transgenic plants. The conditions for monitoring donor site excision using histochemical localization of beta-glucuronidase activity or the alternative spectinomycin resistance assay were established, and used to follow Ac mobility through two generations. Somatic excision was monitored as variegated cotyledons in the T2 generation and germinal excision events were scored in segregating T3 families as complete beta-glucuronidase-mediated staining of cotyledons or as a fully green spectinomycin-resistant phenotype. Using these assays an average germinal excision frequency of 12% was estimated in the T3 offspring from variegated plants. The fidelity of the excision assays was ascertained by comparing the frequency of germinal excision to the frequency of Ac reinsertion at new positions of the genome. Transposition of Ac in 42% of the plants and detection of the characteristic Ac insertion/excision footprints suggests that insertion mutagenesis with the autonomous maize Activator element is feasible in Lotus japonicus. Parameters influencing Ac behaviour, such as dosage, position effects and modification of the element itself, were also investigated comparing homozygous and hemizygous plants from the same family and by analysing different transformants.

Base Sequence

Management of acute intractable headaches using i.v. therapy in an office setting.

Twenty-seven consecutive patients with acute intractable headaches were treated in an office setting with an intravenous protocol of an antiemetic, hydrocortisone sodium succinate, and dihydroergotamine (DHE). All patients had significant pain relief within 45 minutes. Patients who were not pain-free post-treatment uniformly reported decreasing pain at the time of departure from the office. No patients required further treatment (including narcotic medication) for acute headache. All patients were followed for at least 24 hours. Adverse reactions were transient and mild. Akathisia was not uncommon and has probably been underestimated in previous studies.

Acute Disease

Association of posttraumatic spinal arachnoid cyst and syringomyelia.

A patient developed a painful progressive paraparesis following trauma. Metrizamide myelography revealed an arachnoid cyst. A delayed metrizamide computed tomography scan of the area confirmed the cyst and demonstrated a syrinx at that level that was not appreciated on the myelogram. The association of these two lesions after trauma are perhaps more common than appreciated and the importance of a computed tomography scan of the abnormal area on myelography is emphasized.

Adult

A "dipstick" enzyme immunoassay for detection of antibody to Brucella abortus in cattle sera.

An enzyme immunoassay that utilizes antigen bound to a matrix which can be removed from the substrate to stop development is described. The assay which is performed in glass or plastic disposable tubes uses Gel-Bond film strips for attachment of antigen. The only equipment requirements are a rotary shaker and a spectrophotometer (optional). The antigen coated strips are passed through a series of tubes containing test serum, wash solution, antibody-enzyme conjugate, wash solution and substrate-chromogen taking about 45 minutes to perform. In testing sera with or without antibody to Brucella abortus a very high correlation existed between same day tests and tests performed over several days as well as with data on the same sera obtained by an enzyme immunoassay in a microtiter format.

Animals

A class capture enzyme immunoassay for immunoglobulin level determinations in bovine sera.

An enzyme immunoassay for determination of individual isotype concentrations in bovine serum was developed. Polystyrene tubes were coated with affinity purified goat antibovine IgA, IgG1, IgG2 or IgM, washed and then incubated with purified isotypes to ascertain crossreactivity and sensitivity limits. Bound isotype was detected using the homologous affinity purified antibody conjugated to horseradish peroxidase and hydrogen peroxide-2,2-azino-di-(3-ethylbenzthiazoline sulfonic acid), as the substrate/chromogen. A standardized serum was diluted and used as a control for comparison. Several dilutions were used initially, however, determinations may be made with a single dilution, 1:200, for all isotypes. Results for 100 sera were compared to data obtained with the same samples using a radial immunodiffusion technique. A low correlation coefficient was noted between results from the two assays. Day to day variation and within test repeatability were determined for both assays using ten samples. For the enzyme immunoassay method, day to day variation for IgA, IgM, IgG1 and IgG2 determinations was 17.5, 19.3, 7.6 and 7.3% while variation in repeatability (within a test) was 6.2, 5.9, 3.3 and 4.5%, respectively. Day to day variation for the single radial immunodiffusion test for IgA, IgM, IgG1 and IgG2 was 15.4, 26.0, 11.5 and 18.3% and variation repeatability (within a test) was 11.6, 13.9, 5.9 and 8.3%, respectively. The procedures consistently detected 0.1 micrograms of immunoglobulin whereas the radial diffusion sensitivity limit was approximately 500 micrograms.

Animals

Effects of various treatments of bovine complement on its lytic efficacy measured by two different tests.

Bovine complement was treated with various agents known to activate or inactivate one or more of the cascade components. The treated complement was then assessed for remaining hemolytic activity by a tube titration test and a radial hemolysis method. Divalent cation chelators (EDTA and EGTA); immune complexes prepared with serum and IgM, IgG1, IgG2, and IgA isotypes; smooth and rough lipopolysaccharides and lipid A; hydrazine; zymosan; cobra venom factor and brown recluse spider venom caused depletion of complement as determined in the tube titration test. Immune complexes (prepared with serum); hydrazine; cobra venom factor; EDTA and smooth lipopolysaccharide caused loss of hemolytic activity in the radial hemolysis test. This evidence suggests that the radial hemolysis test assessed complement consumed by the alternate pathway, while the tube titration method measured classical pathway consumption.

Animals

Immunoglobulin G1 Fc in colostral whey.

Two IgG1 fragments were isolated from bovine colostral whey. Based on gel diffusion analysis, both fragments originated from the Fc portion of the molecule but were not identical to IgG1 Fc prepared by papain cleavage. The molecular weights were determined to be 66,000 and 14,000 daltons and it was hypothesized that the larger fragment could be a polymer of the smaller. No IgG1 Fab or IgG2 fragments could be demonstrated.

Animals

Binding of Brucella abortus whole cell and lipopolysaccharide antigens to plastics.

Various buffers (0.2 M acetate, pH 4.2; 0.01 M phosphate with 0.15 M sodium chloride, pH 7.2; 0.15 M borate, pH 8.2 and 0.025 M carbonate, pH 9.6) were used as coating buffers with Brucella abortus alkali treated lipopolysaccharide on two types of plastic matrices. Maximum binding occurred using the phosphate buffer. However, as was the case with the other buffers 50 per cent or more of the antigen was removed by five washing procedures. B abortus S19 or S2308, suspended in ammonium acetate-carbonate buffer, pH 8.2, was shown to bind maximally when 10(9) cells were dried onto the plastics. Less than 20 per cent of the cells were removed by five washings.

Adsorption