Harmonisation of ethics committees' practice in 10 European countries

BACKGROUND

The Directive 2001/20/EC was an important first step towards consistency in the requirements and processes for clinical trials across Europe. However, by applying the same rules to all types of drug trials and transposing the Directive's principles into pre-existing national legislations, the Directive somewhat failed to meet its facilitation and harmonization targets. In the field of ethics, the Directive 2001/20/EC conditioned the way of understanding and transposing the "single opinion" process in each country. This led to a situation in which two models of research ethics committees organisation systems exist, being the model in which the "single opinion" is considered to be the decision made by a single ethics committee more effective and simpler in terms of administrative and logistic workload.

METHOD

A survey was conducted in 10 European countries. Members of the European Clinical Research Infrastructures Network working party number 1, with expertise in the field of ethics, responded.

RESULTS

There is a major heterogeneity in the composition of ethics committees among the surveyed countries based on the number of members, proportion of experts versus lay members and expertise of the scientific members. A harmonized education of the ethics committees' membership based in common curricula is recommended by the majority of countries.

CONCLUSIONS

Despite the efforts for harmonization of the European Clinical Trial Directive, from an ethical point of view, there remains a plurality of ethics committees' systems in Europe. It is important to comprehend the individual national systems to understand the problems they are facing.

Ambulation in patients with myelomeningocele: a 12-year follow-up

Factors determining change in ambulatory status were studied over a 12-year observation time in 60 ambulating patients with myelomeningocele. There were 26 female and 34 male subjects with a median age of 22 years (range, 12-54). We used the method of Lindseth to define the neurologic level of the lesion and classified walking ability according to the criteria of Hoffer. The prevalence of spasticity and spine and lower-limb deformities was assessed. Orthopedic and neurosurgical interventions and other medical events were registered, as well as occurrence of pressure sores, musculoskeletal pain, and use of orthoses. There were 19 patients with downward transitions in ambulatory level during the follow-up time. Factors explaining deterioration in these 19 patients included deterioration of the neurologic level of lesion, spasticity, knee and hip flexion contractures, low-back pain, lack of motivation, as well as those of major medical events like stroke, recurrent septicemia, lower limb edema, and invasive surgical interventions.

Inhibition of human leukocyte elastase by N-substituted peptides containing alpha,alpha-difluorostatone residues at P1

A series of tripeptides which contain alpha,alpha-difluorostatone residues at P1-P1' and span the S3-S1' subsites have been shown to be potent inhibitors of human leukocyte elastase (HLE). The tripeptides described contain the nonproteinogenic achiral residue N-(2,3-dihydro-1H-inden-2-yl)glycine at the P2-position. This redidue has previously been shown in the case of HLE to be a good bioisosteric replacement for L-proline. Of the peptides prepared, those which contain the alpha,alpha-difluoromethylene keton derivative of L-valine (difluorostatone) are the preferred residue at the P1-primary specificity position. Substitution at P1 by the corresponding alpha,alpha-difluoromethylene ketones of L-leucine and L-phenylalanine gives inactive compounds. Of the tripeptides described the most potent in vitro compound is ethyl N-[N-CBZ-L-valyl-N-(2,3-dihydro-1H-inden-2-yl)glycyl]- 4(S)-amino-2,2-difluoro-3-oxo-5-methylhexanoate (17B) (IC50 = 0.635 microM). It is presumed that the inhibitor 17b interacts with the S3-S1' binding regions of HLE. Additionally extended binding inhibitors were prepared which interact with the S3-S3' binding subsites of HLE. In order to effect interaction with the S1'-S3' subsites of HLE, the leaving group side of cleaved peptides, spacers based upon Gly-Gly, and those linked via the N epsilon of L-lysine were utilized. One of the most potent extended compounds (P3-P3') in vitro is methyl N6-[4(S)-[[N-[N-CBZ-L-valyl-N- (2,3-dihydro-1H-inden-2-yl)glycyl]amino]-2,2-difluoro-3-oxo-5- methylhexanoyl]-2(S)-(acetylamino)-6-aminohexanoate (24b) (IC50 = 0.057 microM). The described in vitro active inhibitors were also evaluated in hamsters in an elastase-induced pulmonary hemorrhage (EPH) model. In this model, intratracheal (it.) administration of 22c, 5 min prior to HLE challenge (10 micrograms, it.) effectively inhibited hemorrhage (94.6%) in a dose-dependent manner. The described alpha,alpha-difluoromethylene ketone inhibitors are assumed to act as transition-state analogs. The inhibition process presumably acts via hemiketal formation with the active site Ser195 of HLE, and is facilitated by the strongly electron withdrawing effect of the alpha,alpha-difluoromethylene functionality.

BI-RG-587 is active against zidovudine-resistant human immunodeficiency virus type 1 and synergistic with zidovudine

A series of dipyridodiazepinones have been shown to be potent inhibitors of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase. The lead compound, BI-RG-587, had a 50% inhibitory concentration of 84 nM against HIV-1 reverse transcriptase activity. This compound reduced plaque formation of HIV-1 in HeLa cells expressing the CD4 receptor by 50% at 15 nM. BI-RG-587 at comparable concentrations inhibited the production of p24 antigen following the acute infection of CEM T-lymphoblastoid cells or primary human monocyte-derived macrophages with HIV-1. No inhibitory effects against HIV-2 or against three picornaviruses were detected. Zidovudine (3'-azido-3'-deoxythymidine [AZT])-susceptible and AZT-resistant isolates of HIV-1 were equally susceptible to BI-RG-587. AZT and BI-RG-587 exhibited synergistic inhibition of HIV-1BRU at all concentrations examined.

Internal supply of coenzyme to an amperometric glucose biosensor based on a chemically modified electrode

A biosensor for glucose using glucose dehydrogenase immobilized on a chemically modified graphite electrode was supplied with coenzyme, nicotinamide adenine dinucleotide (NAD+), through pores in the material. A graphite rod was hollowed out, leaving 0.3 mm at the end contacting the solution, filled with 10 mM NAD+ and pressurized. The response factor was 40% of that obtained when 2 mM NAD+ was mixed with the sample solution in a flow system. The coenzyme consumption was 11 microliters h-1 representing a 500-fold saving compared to supply through the bulk solution. The biosensor had a linear calibration curve from the detection limit, 1 microM, to 2 mM glucose and a repeatability of 0.3%. The graphite electrode was modified by adsorption of a bis-(benzophenoxazinyl)-terephthaloyl derivative in order to be able to oxidize NADH at 0 mV versus Ag/AgCl, 0.1 M KCl.

Inhibition of HIV-1 replication by a nonnucleoside reverse transcriptase inhibitor

A series of dipyridodiazepinones have been shown to be potent inhibitors of human immunodeficiency virus-1 (HIV-1) reverse transcriptase (RT). One compound, BI-RG-587, had a Ki of 200 nanomolar for inhibition of HIV-1 RT that was noncompetitive with respect to deoxyguanosine triphosphate. BI-RG-587 was specific for HIV-1 RT, having no effect on feline and simian RT or any mammalian DNA polymerases. BI-RG-587 inhibited HIV-1 replication in vitro as demonstrated by in situ hybridization, inhibition of protein p24 production, and the lack of syncytia formation in cultured human T cell lines and freshly isolated human peripheral blood lymphocytes. Cytotoxicity studies of BI-RG-587 on human cells showed a high therapeutic index (greater than 8000) in culture.

Inhibition of human leukocyte elastase by N-substituted tripeptide trifluoromethyl ketones

Several tripeptide trifluoromethyl ketones containing non-naturally occurring N-substituted glycine residues at the P2-position are effective human leukocyte elastase (HLE) inhibitors in vitro and possess IC50 values in the submicromolar range. Deletion of the amino acid at the P3-subsite region affords inactive compounds. The trifluoromethyl ketone derivative of valine is the preferred residue at the P1-position; whereas, the corresponding glycine or alpha, alpha-dimethyl glycine analogs result in inactive compounds.

Cleavage of synthetic peptides by purified poliovirus 3C proteinase

Synthetic peptides, 14-16 residues in length, were used as substrates for purified recombinant poliovirus proteinase 3C. The sequences of the substrates correspond to the sequences of authentic cleavage sites in the poliovirus polyprotein, all of which contain Gln-Gly at the scissile bond. Specificity of cleavages was demonstrated by analysis of 3C digests of synthetic peptides. Relative rate constants for the cleavages were derived by competition experiments. The rate constants roughly correlated with the estimated half-life of the homologous precursor proteins detected in poliovirus-infected cells. The peptide most resistant to cleavage corresponded to the 3C/3D junction, a site known to be cleaved very slowly by 3C in vivo. Substitution of threonine for alanine in P4 position of this peptide, however, resulted in significant cleavage. This observation supports the hypothesis that the residue in P4 position, in addition to the Gln-Gly in P1 and P1', respectively, contributes to substrate recognition. Ac-Gln-Gly-NH2 was not a substrate for 3C.

Ambulation in patients with myelomeningocele: a multivariate statistical analysis

Factors determining ambulation in 163 patients with myelomeningocele were studied by a multivariate statistical method. Neurological dysfunction unrelated to the plaque was analyzed by magnetic resonance imaging. There were no ambulators at the thoracic or L1-L2 level. At the L3 level, 54% ambulated, and at the L4 level, 67% ambulated. Eighty percent were ambulators at L5 and all at the sacral level. Below L1-L2, one-half of the nonambulators had neurological deficiencies caused by syringohydromyelia or Chiari malformations preventing ambulation. Severe scoliosis was closely, age moderately, and hip flexion contracture slightly related to the inability of the other nonambulators to walk, while pelvic obliquity, hip dislocation, or knee flexion contracture was not.