An improved method for the detection and quantification of recombinant protein in transgenic plants

A sensitive method has been developed for the detection of recombinant protein produced as a result of gene transfer into plants. This method is based upon antibody binding, which is then visualized using enhanced chemiluminescence and recorded on x-ray film for long-term storage. The technique is simple, rapid and reliable and can be used to screen large numbers of transgenic plants. Several plant species have been successfully tested in this way for a range of recombinant proteins.     

Signal transduction for chemotaxis in Dictyostelium amoebae

The signal for chemotaxis in D. discoideum is cyclic AMP. This molecule binds to cell surface receptors and triggers the production of inositol (1,4,5)trisphosphate which releases Ca2+ from non-mitochondrial stores. The subsequent chain of signal transduction events brings about the polymerization of cytoskeletal actin (associated with pseudopodium formation) within five seconds and the formation of a peak of cyclic GMP within 10 s. Evidence from streamer F mutants indicates that the cyclic GMP regulates the association of myosin with the cytoskeleton that occurs at 25-50 s and that this phenomenon is concerned with elongation of the amoebae during chemotactic movement.     

Contribution to lignocellulose degradation and DOC formation from a salt marsh macrophyte by the ascomycete Phaeosphaeria spartinicola

Abstract Specifically radiolabeled [¹⁴C-lignin] lignocellulose and uniformly [U-¹⁴C] lignocellulose from the salt marsh grass Spartina alterniflora were incubated with the ascomycete Phaesphaeria s spartinicola . This fungus is the predominant one found on decaying standing dead S. alterniflora leaves in the salt marsh ecosystem. After 45 days of incubation at 20°C, 3.3% of the lignin moiety was mineralized to ¹⁴CO₂ and 2.7% solubilized to DO¹⁴C. Mineralization of the polysaccharides was seven times faster than that of the lignin. About 22% of the radioactivity was evolved as ¹⁴CO₂ but merely 4% was solubilized to DO¹⁴C within the incubation time. Experiments monitoring the ergosterol content of the mycelium incubated with S. alterniflora plant material were done to elucidate the carbon conversion efficiency of the fungus as well as the influence of the cinnamyl phenols p -coumaric and ferulic acid on lignocellulose degration. After 21 days of incubation, P. spartinicola showed a growth yield of 0.45 and 0.38 with and without the additional cinnamyl phenols, respectively. Grown on unextracted S. alterniflora the fungus caused a loss of organic plant material of about 50% with a corresponding growth yield of 0.38 during the incubation period. Investigation of cupric oxide oxidation products of sound and degraded lignocellulose revealed a preferential utilization of the syrinyl and cinnamly phenols compared with vanilly phenols.     

Rhodium catalysts bound to functionalized mesoporous silica

Phosphine and amine functionalized mesoporous silica materials were metallated with Rh(CO)₂(i-Pr₂NH)Cl or Rh₂(CO)₄Cl₂, respectively, to yield catalysts containing the Rh(PPh₂R)₂(CO)Cl or Rh(CO)₂(NH₂R)Cl, where R is a propyl chain bonded to the silica surface, reactive centers. In order to ascertain the effect of pore size on rates of hydroformylation catalysis both 35 and 45 Å pore size materials were used. Using the hydroformylation of octene as a reference reaction, the phosphine based, 45 Å catalysts were 1.5-1.3 times faster than the amine based, 45 Å catalysts, and the 45 Å materials were 2.6-2.1 times faster than the 35 Å materials. The orientation of the catalyst relative to the functionalized surface, and the steric environment around the catalyst active site appear to be significant in determining rate of reaction. The ability of the surface bound phosphine catalysts to affect hydroformylation was strongly influenced by the steric constraints of the substrate. Terminal alkenes were readily hydroformylated and norbornene was slowly hydroformylated, but pinene, trans-cyclododecene, cyclohexene and cholesterol were nonreactive to the catalytic center.     

Humoral and cellular immune reactions against tumor cells in patients with urinary bladder carcinoma

Serum IgG fractions from a large and homogeneous group of patients with transitional cell carcinoma of the urinary bladder (TCC) were tested for their capacity to induce antibody-dependent cellular cytotoxicity (ADCC) with lymphocytes from healthy donors against a TCC-derived target cell and one derived from adenocarcinoma of the colon. Both targets have previously been shown to be of comparable susceptibility to cell-mediated lysis in vitro. Some of the IgG preparations showed strong and dose-dependent ADCC against either one or both targets, while others gave weak reactions or none at all. Similar results were obtained with IgG from a matched group of patients with prostatic carcinoma who were used as clinical controls (CC). In parallel experiments, lymphocytes taken from the two donor groups at the same time as the serum samples were tested for their direct cytotoxicity (CMC) against the two targets. CMC gave similar results to ADCC. The differences in cytotoxicity displayed by either IgG or lymphocytes from individual donors were analysed statistically, using nonparametric statistics. To avoid introducing bias due to arbitrary data selection, the entire set of results, comprising both high and low reactors, was included in the statistical assessment. ADCC of the TCC donors' IgG against the TCC target was significantly stronger than against the colon carcinoma and also significantly stronger than that of the control donors. Similarly, the TCC patients' lymphocytes displayed a significantly higher CMC against the TCC target than against the control targets. This was not seen when the lymphocytes from the patients with prostatic carcinoma were tested. When CMC and ADCC of individual donors were compared, a statistically significant correlation between these activities was seen in three of the four donor/target combinations. These results support earlier findings and suggest that a significant fraction of both the disease-related and the 'non-selective' CMC (NK) displayed by cancer patients lymphocytes against allogeneic tumor cells in vitro reflects antibody-dependent reactions.     

The importance of observer effort on the accuracy of breeding success estimates in the Common Guillemot Uria aalge

ABSTRACT

Capsule: A data-thinning approach was used to assess the effects of reducing the frequency of nest-checks on estimates of breeding success of Common Guillemots Uria aalge. Inter-year and inter-colony differences in fledging age and their implications for setting a minimum age after which a chick could be assumed to have fledged were evaluated.

Aims: To assess the consequences of reducing sampling frequency on the estimation of breeding success, and on the robustness of the assumption that breeding has been successful if a chick survives to 15 days old.

Methods: Breeding success, ages at fledging and loss of chicks were estimated from daily checks at two Scottish colonies over a six-year period. Data-thinning was used to assess the consequences of reducing checks from daily to every two or three days. Breeding success was recalculated assuming that all chicks surviving to 15 days fledged.

Results: Reducing the frequency of checks from daily to every second or third day resulted in a small but statistically significant increase in the estimate of success. Between 20% and 25% of chick losses occurred when chicks were ≥15 days old. Assuming that these chicks had fledged resulted in significant increases in breeding success.

Conclusion: Assumptions about whether or not a chick fledged had a greater impact on the estimate of breeding success than reducing the frequency of nest-checks from daily to every second or third day. There was no threshold age after which a chick could be assumed to have fledged. These findings are relevant to other monitoring schemes where there is pressure to reduce input. Sampling methods used in monitoring schemes need to be clearly stated and changes in protocols documented so that sampling effects can be incorporated into future analyses.