Leif Christensen

Peptide nucleic acids containing adenine or guanine recognize thymine and cytosine in complementary DNA sequences

Peptide nucleic acid (PNA) monomer building blocks for the introduction of G and A are prepared and used to synthesise H-T4XT5-Lys-NH2(X = G or A), which are shown by Tm measurements to recognize their complementary DNA sequences in both the parallel (N-terminal PNA/5′-DNA) and the anti-parallel mode; the stoichiometry in each case is (PNA)2/DNA.

The Bologna process and medical education

The Bologna Process designates the ongoing activities whereby the Ministers responsible for Higher Education in Europe attempt to change and harmonize fundamental aspects of all higher education in the many countries involved. This grand scheme is gaining momentum. The number of participating countries is increasing, more aspects of higher education are included and the number of activities and projects is growing. Medical education has so far been neglected in the process and awareness of the development at medical schools has been limited. The purpose of this paper is to introduce the Bologna Process, its background, objectives and main activities and to draw attention to some of the challenges medical education will probably have to face in the near future such as a structure based on two main cycles, undergraduate and graduate, a system of easily readable and comparable degrees and European cooperation in quality assurance including a system of accreditation, certification or comparable procedures. The position of medical education towards the Bologna Process is essential.

WFME Global Standards in Medical Education: status and perspectives following the 2003 WFME World Conference

The development of the World Federation for Medical Education (WFME) Global Standards in Medical Education can be viewed as consisting of 3 overlapping phases. The first phase concerned the formulation of the Standards at a time when there were no comprehensive, globally recognised standards. The second phase comprised the piloting and evaluation of the WFME Standards, of which the world conference was a part. Based on the results of this, it is envisaged that, in the third phase, more institutions, countries and regions will become familiar with the Standards and further application and refinement will take place as feedback is received. This may also lead to formal recognition or accreditation of medical schools by the WFME. As part of the evaluation process, the WFME organised a world conference, Global Standards in Medical Education for Better Health Care , in March 2003. In a remarkable example of international collaboration, the conference strongly endorsed the evaluation process and encouraged its continuation and the updating of the Standards in the light of further experience.

Sequence dependent N-terminal rearrangement and degradation of peptide nucleic acid (PNA) in aqueous solution

The stability of the PNA (peptide nucleic acid) thymine monomer ¿N-[2-(thymin-1-ylacetyl)]-N-(2-aminoaminoethyl)glycine¿ and those of various PNA oligomers (5-8-mers) have been measured at room temperature (20 degrees C) as a function of pH. The thymine monomer undergoes N-acyl transfer rearrangement with a half-life of 34 days at pH 11 as analyzed by 1H NMR; and two reactions, the N-acyl transfer and a sequential degradation, are found by HPLC analysis to occur at measurable rates for the oligomers at pH 9 or above. Dependent on the amino-terminal sequence, half-lives of 350 h to 163 days were found at pH 9. At pH 12 the half-lives ranged from 1.5 h to 21 days. The results are discussed in terms of PNA as a gene therapeutic drug as well as a possible prebiotic genetic material.

Neo-colonialism versus sound globalisation policy in medical education

to designing an assessment strategy. Clearly, the claims of improved knowledge retention need to be tested in authentic settings and over longer periods. There are many aspects of test-enhanced learning that have yet to be elucidated. Do learners undergoing an increased frequency of testing retain knowledge for much longer periods, such as a year or more? What difference does test-enhanced learning make to the accessibility and use of knowledge in the context of solving problems? Given the growing interest in competency-based programmes, how well does the testing effect bear out when multiple different assessment formats are used? Test-enhanced learning based on increased frequency of assessment is likely to be expensive in terms of teacher time and resources; we need to know whether the apparent gains in knowledge retention are worth the effort.

Process-outcome interrelationship and standard setting in medical education: the need for a comprehensive approach

An outcome-based approach to medical education compared to a process/content orientation is currently being discussed intensively. In this article, the process and outcome interrelationship in medical education is discussed, with specific emphasis on the relation to the definition of standards in basic medical education. Perceptions of outcome have always been an integrated element of curricular planning. The present debate underlines the need for stronger focus on learning objectives and outcome assessment in many medical schools around the world. The need to maintain an integrated approach of process/content and outcome is underlined in this paper. A worry is expressed about the taxonomy of learning in pure outcome-based medical education, in which student assessment can be a major determinant for the learning process, leaving the control of the medical curriculum to medical examiners. Moreover, curricula which favour reductionism by stating everything in terms of instrumental outcomes or competences, do face a risk of lowering quality and do become a prey for political interference. Standards based on outcome alone rise unclarified problems in relationship to licensure requirements of medical doctors. It is argued that the alleged dichotomy between process/content and outcome seems artificial, and that formulation of standards in medical education must follow a comprehensive line in curricular planning.

6-THIOGUANINE IN PEPTIDE NUCLEIC ACIDS. SYNTHESIS AND HYBRIDIZATION PROPERTIES

Abstract The synthesis of N-((2-amino-6-benzylthiopurine-9-yl)acetyl)-N-(2-tBoc-aminoethyl)glycine 4 and its incorporation into a peptide nucleic acid (PNA) oligomer are described. Introduction of a single 6-thioguanine residue (6sG) in the PNA of a 10-mer PNA:DNA heteroduplex resulted in a decrease in Tm of 8.5°C. Furthermore, we observed a hypochromic and a bathochromic shift of 6 nm above 346 nm when the 6sG containing PNA was hybridized to its complementary DNA strand.