A novel application of the popular web instruction architecture Blackboard Academic Suite® is described. The method was applied to a large number of students to assess quantitatively the accuracy of each student’s laboratory skills. The method provided immediate feedback to students on their personal skill level, replaced labour-intensive scrutiny of laboratory skills by teaching staff and identified immediately those students requiring further individual assistance in mastering the skill under evaluation. The method can be used for both formative and summative assessment. When used formatively, the assessment can be repeated by the student without penalty until the skill is mastered. When used for summative assessment, the method can save the teacher much time and effort in assessing laboratory skills of vital importance to students in the real world.

Because of their widespread industrial and medical importance, there is considerable interest in the manipulation and improvement of Lactobacillus strains using modern genetic engineering techniques. However, most reports have focused on industrial strains and often have resulted in non-reproducible transformation efficiencies. We have developed an optimised protocol for electroporating foreign plasmid DNA into clinical strains of lactobacilli. Treatment of the recipient lactobacilli with either lysozyme, glycine or penicillin improved electrotransformation efficiencies up to 480-fold. A critical step in achieving efficient and reproducible electrotransformation of clinical lactobacilli with the plasmid pSA3 was the requirement for a post-pulse recovery time of 2–3 h, combined with the use of sub-inhibitory concentrations of antibiotics in the selective plates. While pNZ17 transformants also benefited from a post-pulse recovery period, good transformation efficiencies could be achieved when plated directly onto selective concentrations of chloramphenicol. We also observed significant differences in electrotransformation efficiencies between our guinea pig vaginal Lactobacillus isolates (maximum of 4.8 × 104 transformants/μg pNZ17 DNA) and the human L. casei strain ATCC 393 (3.7 × 106 transformants/μg pNZ17 DNA). An optimised procedure for the electroporation of plasmid DNA into lactobacilli is described.

In this work the growth hormone-encoding gene (GH) from the fish barramundi (Lates calcarifer) was characterized by nucleotide (nt) sequence analysis and comparative studies on higher and lower vertebrate GH were performed. The barramundi GH contains six exons and five introns. A putative transcription start point 21 nt downstream from a potential TATAAA box was determined, with a modified primary transcript size of 1615 nt predicted. cis-Acting elements potentially important for transcriptional regulation at the basal, hormone-responsive and pituitary gland-specific levels were identified. Several microsatellite and minisatellite repetitive sequences were shown to be present within noncoding portions of this gene. Repeat sequences similar to the deca- and undeca-minisatellites of the barramundi GH were observed in the corresponding introns of the tilapia, but not other teleost GH. Comparative studies on the Osteichthyes, Mammalia and Aves vertebrate class GH promoters suggested that the TATAAA box was the only conserved region between these sequences. Conserved sequences, however, were identified within the GH promoters of different species from the Osteichthyes or Mammalia classes. The Osteichthyes A + T-rich sequence (consensus GATRMATYWAAWCA, where R=A or G; M=A or C, Y=C or T and W=A or T) is the only conserved region identified between teleost GH promoters, and is most likely involved in the pituitary gland-specific expression of these genes.

Monoclonal antibodies designated 8G10/48 and 9E3/48 raised against mature asexual blood stages of Plasmodium falciparum inhibit parasite growth in vitro. Both antibodies bind to an epitope which includes the linear sequence Ser Thr Asn Ser and which is present in a cDNA clone from a P. falciparum expression library. These antibodies recognise a glycosylated antigen of approximately 51 kDa which is located on the merozoite surface membrane.

La production d'un grand nombre d'anticorps monoclonaux contre P.f. a permis l'identification d'un grand nombre d'antigenes parasitaires