The application process for nurse anesthesia programs: is there room for improvement?

In summary, we have observed that competition among programs for applicants has been strong in recent years. We believe the answers to preparation of adequate numbers of CRNAs in the future should be based upon cooperation and major recruitment activities within our geographical area. In addition, the results of this study will help us focus on strengths and areas needing improvement in our application process and programs. This is important to attract well-qualified students and maintain our reputation for excellence.

An investigation of the HUMVWA31A locus in British Caucasians

A number of short tandem repeat (STR) loci are currently being examined for their usefulness as markers of identity; HUMVWA31A is one such locus. We used a high-sieving agarose technique to type 200 British Caucasians for this locus. Comparison of the resultant allele frequencies with other published databases showed that their distributions were similar. Observed heterozygosity was similar to that reported in other population studies but significantly lower than expected. A goodness of fit analysis of observed and expected genotypes was highly significant, suggesting a deviation from Hardy-Weinberg equilibrium, although reports from other populations appeared not to show such differences. The possibility that mistyping had led to an erroneous statistic was investigated by detailed examination of samples within our own laboratory and in two other laboratories, involving verification of the agarose typing by both automated fluorescent detection techniques, and sequencing. Other reported deviations from Hardy-Weinberg equilibrium in STR systems are discussed.

Investigation of the STR locus HUMTH01 using PCR and two electrophoresis formats: UK and Galician Caucasian population surveys and usefulness in paternity investigations

Two hundred unrelated Caucasians from the UK and 210 from Galicia (NW Spain) have been genotyped for the HUMTH01 locus using polymerase chain reaction (PCR) amplification followed by high sieving agarose electrophoresis (UK samples) and polyacrylamide electrophoresis (Galician samples). Allele and genotype frequencies obtained from both populations were in close agreement to those seen by other workers and chi 2 tests of the two populations showed that both were in Hardy-Weinberg equilibrium. The potential usefulness of HUMTH01 in paternity investigations was analysed by constructing, within each population, false family trios, each with a non-father, in order to estimate the actual exclusion rate. The observed rate of exclusion was in close agreement with the expected rate for both populations. Examination of the mother-child pairs in the false families showed a common allele in every case and no evidence of mutation or non-Mendelian inheritance was observed. The HUMTH01 locus shows an informative polymorphism and the production and analysis of population databases is easily achieved. The use of PCR followed by electrophoresis in either gel format appears to provide a quick and straightforward method for investigating the HUMTH01 locus.

Investigation of the between-gel and within-gel variation in fragment size determinations found when using single locus DNA probes

Measurement variation in the sizing of DNA fragments has been assessed, examining within-gel and between-gel variability. Also, measurement variation detected between two different laboratories, using both manual and automated measurement techniques, has been investigated and discussed.

Aberrent group B reactions detected in mixtures of semen and vaginal secretions possibly due to acquired B

Routine ABO grouping tests performed on vaginal swabs from a group O female showed the presence of blood group B activity as well as the expected A and H activity after intercourse with her group A partner. The source of the B activity was readily detectable using the Laboratory's routine elution test, but it was not detectable when a monoclonal anti-B was used and detection by the inhibition technique was possible only with a selected antiserum. A possible explanation of the reactions observed is that the acquired B is capable of reacting with only a portion of the antibodies present in normal polyclonal anti-B sera.

Biostatistical parameters of paternity and calculation by a computer programme

Biostatistical Parameters such as the paternal markers in the child (PM), individual exclusion change (IEC) probability of incidental involvement (Z), probability of paternity (POP), plausibility of paternity according to Essen-M oller ( PLEM ) and paternity index (PI) are defined and discussed in respect to their application in cases of disputed paternity. In order to calculate these parameters for up to 24 marker systems, including HLA under strict observation of the linkage disequilibrium, a computer programme in BASIC has been developed.

The detection of the HLA-A1 antigen in bloodstains

The wealth of antigens in the HLA white cell blood group system makes their detection in bloodstains a fascinating possibility for the forensic serologist. The work presented in this paper is concerned with the detection of the HLA-A1 antigen in bloodstains. The essence of the technique employed is the inhibition of the lymphocytotoxic activity of anti-HLA-Al antisera by HLA-A1 bearing bloodstains.

A 4 cm length of bloodstained thread was used for each test and incubation with the HLA antisera was overnight at 4°C. An inhibition of the cytotoxic activity of the HLA-A1 antiserum of 55–100 per cent was taken as indicative of the presence of the HLA-A1 antigen in the stain, while an inhibition of 0–45 per cent indicated the absence of the antigen. Inhibitions in the range 46–54 per cent were regarded as indeterminate.

Three antisera were used in parallel as these produced more satisfactory results than those of a single antiserum. The HLA-A1 antigen appeared to show little loss of activity in stains up to 230 days old.

The additional finding that whole blood samples could be successfully typed for the HLA-A1 antigen using this inhibition technique is of particular importance because, in forensic casework, fresh blood samples taken into the media ideal for normal HLA typing may not always be available.

Lawyers should take note that, although the HLA system promises to be of great value in forensic problems, owing to the highly specialized nature of the techniques employed it will not be immediately applicable to routine case-work.

Serological studies of the H activity of Oh red cells with various anti-H reagents

Several examples of Oh cells have been investigated with various anti-H reagents. After enzyme treatment of the cells with either papain or neuraminidase, very high titres were obtained, particularly with some preparations of Ulex europeus. Fractionation of anti-H Ulex showed that the anti-H component inhibitable by L-fucose required papain treatment of the Oh cells for optimal activity whereas the component not inhibitable by L-fucose agglutinated preferentially Oh cells treated with neuraminidase. The anti-H lectin Cytisus sessifolius which is not inhibitable by L-fucose gave no reaction with papain-treated Oh cells but reacted well when the Oh cells were treated with neuraminidase. Normal O cells were almost equally well agglutinated by the lectins when treated by either of the two enzymes. That the various lectin components activated by enzymes had H specificity was shown by the fact that their activity was inhibited by purified H substance, partially inhibited to L-fucose and 2-fucosyllactose and not at all by purified Lea substance and non-secretor salivas. In spite of the high titres obtained with Oh cells by the enzyme technique, the amount of H present on the red cells, judged by inhibition tests, in comparison with normal group O cells was very small.

The use of low ionic strength solution (LISS) in elution experiments and in combination with papain-treated cells for the titration of various antibodies, including eluted antibody

The investigation presents evidence for the value of suspending red cells in a low ionic strength medium for elution experiments since this has the effect of increasing the uptake of antibodies by the red cells. In addition it has been shown that for the titration of low affinity antibodies, and also of eluted antibodies, the combining capacity of which may be impaired through the elution process, it is an advantage to use a LISS-enzyme (papain) technique.

Observations on the use of an autoanalyser and a manual technique for the detection of the red cell antigens C, D, E, c, K and S in bloodstains

The results of the detection of the Rh antigens (D, C, E, c) and the S and K antigens by an elution technique comparing the AutoAnalyser and a manual method for the detection of eluted antibody are presented. Investigation of a series of anti-D sera demonstrates that while it is not too difficult to select antisera for the detection of the D antigen in fresh stains (i.e. up to 4 weeks old) some of these sera will not be satisfactory for typing older stains. The AutoAnalyser system used is low ionic strength/polybrene which has a capacity for detecting 0.002 microgram/ml of anti-D, but in spite of this degree of sensitivity the manual technique for the detection of eluted antibody compared very favourably and tended, where older stains were being tested, to give more conclusive results than the AutoAnalyser. The superiority of the manual technique was most pronounced when detecting the S and K antigens.

The advantage of a build-up anti-globulin technique for the detection of immunoglobulin on the red cells of rabbits infected with trypanosomes. A preliminary report

A build-up anti-globulin technique has been used to detect immunoglobulin on the red cells of rabbits infected with Trypanosoma brucei brucei S 42 and 427. The method, which is useful for the detection of immunoglobulin on sparsely coated red cells, involves treating the red cells of infected rabbits with antiglobulin followed by alternate globulin and antiglobulin layers until a lattice is built up which allows agglutination to occur. The red cells of five infected rabbits have been tested with anti-rabbit IgG,-IgM and broad spectrum anti-globulin reagents at intervals after infection and following the administration of Berenil, a drug which destroys trypanosomes. The positive anti-globulin reactions which developed following inoculation with trypanosomes were much reduced after giving Berenil. The tests became more strongly positive again in two rabbits after reinfection.

Frequencies of secretors and non-secretors of ABH group substances among 1,000 alcoholic patients

The ABO blood group and secretor status of 1,000 alcoholic patients has been determined. The patients were drawn from large alcoholic units in the London area together with several small units, including rehabilitation centres, nd 127 were from Aberdeen.The findings have been compared with appropriate controls which take into account the ethnic origin of the patients in the series. A striking disturbance of the secretor/non-secretor ratio among group A patients compared with the controls is observed. There is an increase in group A non-secretors, which is almost exactly balanced by a loss of group A secretors so that the overall frequency of the group A phenotype is not disturbed. It is difficult to find an acceptable explanation for these results.

Antigen-antibody studies in the ABO blood group system with particular reference to cross-reacting antibodies in group O sera

A comparison has been made between the reactivity of cross-reacting antibody from group O sera titrated against A cells and the reactivity when titrated against cells of group B. It is considered that the experimental findings require the postulation that cross-reacting antibodies which are produced in response to stimulation by antigen A have a different configuration from those produced in response to antigen B.

The results also suggest that elution of antibody from cells at 56° may cause minor changes in spatial configuraiton which diminish the ability of some antibodies to combine with some subgroups of the A system.

The cross-reacting antibodies of group O sera: immunological studies and possible explanation of the observed facts

Eluates were prepared from fifteen group O sera using A and B red cells. The sera originated from group O women who had either A or B children. In eight of the chosen sera, anti-A was the immune antibody and in seven, the anti-B. Antibody cross-reacting with both A and B red cells was found in all the eluates.

The results of titrations of cross-reacting antibody eluted from the red cells, both before and after absorption with A or B red cells and group specific substances, all indicate that the cross-reacting antibody produced by stimulation with antigen A is different from that produced by B.

The work also includes experiments using A₂, A_x and A_m red cells in conjunction with an immune group O serum chosen because of its good reactivity with A_x and A_m cells. It is particular interest that potent eluates from this serum prepared from A₁ cells failed to agglutinate cells of A_x slightly less potent eluates from group B agglutinated A_x to a titre of 128.

Two types of cross-reacting antibodies are postulated depending upon whether they are produced in response to stimulation by A or B. It is thought that most of the cross-reactive antibodies are directed against common portions of the blood group active oligosaccharide side chains, including the substituent at carbon atom 2 of the terminal non-reducing sugar (A (NH.CO.CH₃) or B(OH) specificity).

Denaturation or alteration of the spatial configuration of the antibody molecules after dissociation from the antigen may account for some of the observed phenomena.

Technique for the evaluation of cold antibodies in cases for operation under hypothermia

Cold antibodies were found in 95 out of 112 cases active at 10 degrees C. but in 86 of these the whole blood compatability test described in this paper was negative or very weakly positive. It is safe to transfuse blood incompatible with a cold antibody if the whole blood test is weak or negative.