[Nitrous oxide is not widely used for children in the emergency departments in The Netherlands]. / Lachgas wordt niet algemeen toegepast bij kinderen op de SEH.

Nitrous oxide was introduced in The Netherlands as an easily accessible and effective agent for procedural sedation and analgesia (PSA) in children at the Emergency Department. It was expected that its adoption would increase due to the rapid onset of action, limited side effects and the non-invasive character. In this article, we discuss the efficacy and use of nitrous oxide in The Netherlands. Nitrous oxide is a safe and effective agent for children undergoing low-complex procedures. However, the analgesic effect is limited for complex procedures such as fracture reposition, necessitating the use of additional agents such as opioids. Against our expectations, most Dutch Emergency Departments do not use nitrous oxide. Reasons for this are the limited analgesic effects for most procedures, the availability of good alternatives and cost and sustainability considerations.

Effect on tissue differentiation and articular cartilage degradation of a polymer meniscus implant: A 2-year follow-up study in dogs.

BACKGROUND: Replacement of the meniscus by an implant could potentially avoid cartilage degeneration. HYPOTHESIS: An implant of degradable polycaprolacton-polyurethane should act as a temporary scaffold enabling regeneration of a new meniscus by slow degradation of the polymer and simultaneous in-growth and differentiation of tissues into the typical cartilage-like tissue of the meniscus. STUDY DESIGN: Controlled laboratory study. METHODS: In 13 dogs' knees, the lateral meniscus was replaced with a porous polymer implant (6 and 7 for 6- and 24-month follow-up, respectively); in 7 knees only a meniscectomy was performed. In 6 knees, no surgery was performed. After 6 and 24 months, the implants and the articular cartilage were histologically evaluated. Compression-stress tests were performed on implant biopsy specimens. RESULTS: The implants were fully integrated into the tissue without formation of a capsule. The foreign body reaction did not exceed grade I. Differentiation from fibrous- to cartilage-like tissue was pronounced after 24 months. Viable cells were particularly absent after 24 months in central parts of the most anterior part of the scaffold. The mechanical properties of the implants were intermediate between the scaffold before implantation and native meniscus tissue and were not different between 6 and 24 months. After both 6 and 24 months, small areas of the implant were not covered with tissue. Cartilage degeneration was not prevented. CONCLUSION: A final remodeling of tissue into neomeniscus tissue could not take place since the original structure of the polymer was still present after 24 months. The implant did not prevent cartilage degradation. Several factors are discussed that may be responsible for this. CLINICAL RELEVANCE: Although clinical application of a polymer implant for the replacement of the entire meniscus is not supported by this study, the authors strongly believe in the concept, but further improvements in the implant and surgical technique are needed before such an implant can be recommended for human clinical use.

Accuracy and initial stability of open- and closed-wedge high tibial osteotomy: a cadaveric RSA study.

We analyzed the difference in angle-correction accuracy and initial stability between open-wedge (OWO) and closed-wedge tibial valgus osteotomy (CWO). Five fresh-frozen pairs of human cadaver lower limbs were used; their bone mineral density (BMD) was measured with DEXA and a planned 7 degrees valgus osteotomy was performed, either with an open (right knees) or closed (left knees) technique. All knees for osteotomy were fixed with a rigid locked plate. In OWO, tricalcium phosphate (TCP) wedges were inserted. The knees were subjected to an increasing cyclic axial load until failure, while measuring the relative displacement of the bony segments with roentgen stereophotogrammetric analysis. The mean postoperative valgus correction angle was 9.5 degrees +/-2.8 degrees for CWO (over-correction of 2.5 degrees ) and 6.2 degrees +/-2.0 degrees for OWO (under-correction of 0.8 degrees ) (P =0.08). The data of displacement under load bearing showed no significant differences in rotations and translations in any direction. No significant correlation between BMD and the moment of failure was found (P =0.27). This study has shown that both methods gave an acceptable correction with a high variation of postoperative correction angles. There was a tendency for over-correction in the CWO group but no significant difference was found. There was no difference in initial stability between CWO and OWO with a rigid locked-plate fixation.

The expression of blood group P1 in post-enteropathic haemolytic uraemic syndrome.

Blood group P1 expression was scored by direct agglutination in 32 patients who had previously developed post-enteropathic haemolytic uraemic syndrome (HUS). Sixty-six children of similar ages undergoing venepuncture for other renal disorders acted as controls. The expression of P1 in controls was that expected from the normal caucasian population, 23% being negative. By contrast, there was an excess of HUS patients with weak or absent expression of P1 (chi 2 for linear trend 5.45, P less than 0.02), and this was particularly evident in those with a poor outcome. Verotoxin (VT), which is associated with HUS, requires the terminal disaccharide of the P1 antigen to bind to cells, and after internalization disrupts the transcription of ribonucleic acid. Mature erythrocytes do not synthesize protein and may be toxin resistant. We postulate that strong expression of P1 antigen may promote the binding of VT to red cells and thus reduce the dose to vulnerable nucleated endothelial cells. P1 positivity may be protective, and P1 negativity a risk factor in HUS.

A human dispermic chimaera first suspected from analyses of the blood group gene-specified glycosyltransferases.

The red cells of a normal male blood donor, K.S., were first grouped as B but he was found to lack anti-A in his serum. Closer investigation revealed that his red cells had very weak A activity, demonstrable only by absorption and elution of anti-A. He is a non-secretor of ABH and a secretor of Lea. Blood group A-, B and H-gene specified glycosyltransferases were detected in his serum. In contrast to the finding of a B antigen of normal strength on his red cells, the B transferase in his serum was only about 30% of the normal level and, despite the very weak A activity of K.S's red cells, the A transferase level was about 50% of that found in the serum of group A individuals with normal strength of A antigen. Moreover, the A transferase on the basis of its pH optimum, Km values for donor and acceptor substrates, activation by divalent cations, isoelectric focusing profile and capacity to convert O to A-active cells, was characterized as the product of an A1 gene. A family study showed that K.S's wife is group A2 and that they have two sons, one group A2 and the other group B. The group B son is assumed to have inherited a B gene from the propositus but the level of B transferase in the son's serum is three times as high as that in his father's serum. The wife of the propositus and his group A2 son have normal A2 transferases in keeping with their A2 red cell status. The A2 son therefore appears to have inherited an A2 gene from his mother but neither the A1 nor the B gene shown to be carried by his father. The distribution of transferase activities in K.S's red cells differs from that in his serum. A level of B transferase within the normal range was found in his red cell membranes but a very low level of A transferase was detected. The discrepancies between the serum transferases and ABO red cell group, together with the pattern of inheritance within the family, led to a suspicion of chimaerism. This was confirmed by the finding of fibroblasts with the female 46XX karyotype in cultures of the propositus' skin. These results suggest that K.S. is a dispermic chimaera with two different cell lines of the genotypes BO and A1O or A1A1. The group A2 son is assumed to have inherited an O gene from his father. It seems probable that K.S.'s bone marrow and reproductive organs are comprised predominantly of the XY cell line which carried the blood group BO genotype whereas his skin and other tissues which contribute the A1 transferase to his plasma, are partly made up of the XX cell line which carries the blood group A1O or A1A1 genotype.

Human serum antibodies to melibiose and other carbohydrates.

Human sera were screened by passive haemagglutination for antibodies to various sugars. A high incidence of antibodies to melibiose was observed. There were also a few antibodies to other sugars and to dextran.