Système RH : dépistage de D partiels avec RHD/RHCE gène hybride

Aim of the studyThe determination of the RhD phenotype is important in transfusion medicine. However, the complexity of the expression of the D antigen is the cause of the discrepancies observed between two serological determinations and the omission by serology of some variants that can be cause alloimmunization. Therefore, it is important to known in a population the RHD alleles responsible for partial D and weak D phenotype. The aim of the study was the screening of partial D with RHD/RHCE gene hybrid by PCR-multiplex.Materials and methodsOur study involved 308 blood donors from Tunisian Sahel (269 D positive and 39 D negative). We used the multiplex PCR assay to amplify specific exons of the RHD gene 3, 4, 5, 6, 7, 9 and 10. Further molecular investigations were carried to characterize the RHD variants that were detected by the multiplex.ResultsIn the 269 D positive samples, one case showed the absence of amplification of exons 4 and 5 of RHD gene. This variant was identified by PCR-SSP on weak D type 4. None of the RHD exons were amplified from DNA of 39 D negative samples in favor of a total deletion of the RHD gene.ConclusionWe have no found any partial D variant with RHD/RHCE gene hybrid. Results in D negative samples showed that RHD gene deletion is the most frequent mechanism of D negative phenotype in the Tunisian population.     

Influence of procedural variations during the laboratory phase of complete denture fabrication on patient satisfaction and denture quality

Objectives

To compare subjective and objective outcomes of complete dentures fabricated with standard clinical protocols, but omitted selected steps during the laboratory phase.

Materials and methods

Forty-three edentulous patients (mean age 58.1 years, SD 9.9, range 35–78), were consecutively recruited and randomly assigned to one of four groups according to selected variations of laboratory steps: Group 1 (n = 10), omission of secondary casts obtained from impressions in border moulded custom trays; Group 2 (n = 10), omission of secondary casts and face-bow articulator mounting; Group 3 (n = 10), omission of face-bow mounting; Group 4 (n = 13), no steps omitted (control). Clinical procedures for all groups were identical, and performed by senior dental students under supervision of prosthodontists, all of whom were blinded to the Group. At 1-, 4- and 12-weeks after delivery, patients rated their overall satisfaction, as well as a range of functional factors using visual analogue scales. An independent blinded prosthodontist similarly rated four domains of denture quality at the 1-week follow-up.

Results

No significant differences were noted among the groups in all aspects of patients’ assessments at all the time points (P > 0.1). There were no significant differences in prosthodontists’ ratings of denture quality in any of the domains examined (P > 0.1).

Conclusion

Selected omissions of steps (face-bow mounting and/or secondary casts) during the laboratory phase of complete denture fabrication has only a minor role, if any, in subjective and objective outcomes, contrasting with the common belief that such omissions will adversely affect outcomes.

Clinical significance

General practitioners provide most complete dentures. Many do not follow all the procedures they were taught at dental school. Our finding that omitting frequently advocated steps made no difference to patient satisfaction or to denture quality suggests that cost-effectiveness through simplifications be considered in practice and in education.     

Nucleotide metabolic mismatches in mammalian hearts: implications for transplantation

Introduction

Human donor organ shortages have led surgeons and scientists to explore the use of animals as alternative organ sources. Acute thrombovascular rejection (AVR) is the main hurdle in xenotransplantation. Disparities in nucleotide metabolism in the vessels of different species may contribute significantly to the microvascular component of AVR.

Methods

We evaluated the extent of nucleotide metabolism mismatch in selected organs and endothelial cells of different mammals with particular focus on the changes in activity of ecto-5’-nucleotidase (E5’N) elicited by exposure of porcine hearts or endothelial cells to human blood (ex vivo) or human plasma (in vitro).

Results

E5’N activity in the rat heart was significantly higher than in other species. We noted a significant difference (p<0.001) in E5’N activity between human and pig endothelial cell lines. Initial pig aortic endothelial E5’N activity decreased in vitro after a three-hour exposure to human and porcine plasma while remaining constant in controls. Ex vivo perfusion with fresh human blood for four hours resulted in a significant decrease of E5’N activity in both wild type and transgenic pig hearts overexpressing human decay accelerating factor (p<0.001).

Conclusions

This study provides evidence that mismatches in basal mammalian metabolic pathways and humoral immunity interact in a xenogeneic environment. Understanding the role of nucleotide metabolism and signalling in xenotransplantation may identify new targets for genetic modifications and may lead to the development of new therapies extending graft survival.     

Microarray-based molecular detection of foot-and-mouth disease, vesicular stomatitis and swine vesicular disease viruses, using padlock probes

The World Organization for Animal Health (Office International des Epizooties, OIE) includes the diseases caused by foot-and-mouth disease virus (FMDV), swine vesicular disease virus (SVDV), and vesicular stomatitis virus (VSV), as "Diseases Notifiable to the OIE". Foot-and-mouth disease (FMD) outbreaks have severe economical as well as social effects and cannot be differentiated from the diseases caused by the other two viruses on the basis of clinical symptoms. Efficient laboratory techniques are therefore required for detection and identification of the viruses causing similar vesicular symptoms in swine. A rapid method is described using padlock probes and microarrays to detect simultaneously and differentiate the three viruses in a single reaction, as well as providing serotype information in cases of VSV infection. The padlock probe/microarray assay detected successfully and identified 39 cDNA samples of different origin representing the three viruses. The results were in complete agreement with identities and serotypes determined previously. This novel virus detection method is discussed in terms of usefulness and further development.