Uncertainty of measurement for competitive and indirect ELISAs.

A method for the estimation of the uncertainty of measurements for Gaussian outcomes of enzyme-linked immunosorbent assay (ELISA) is described using competitive and indirect foot and mouth disease (FMD) ELISAs. Assay repeatability was determined by random effects analysis of variance, and the normality of the residuals was checked. The standard errors of the individual predicted values were transformed into confidence intervals around the corresponding observed values and further transformed into probabilities of being above/below a cut-off. Logistic regression models were subsequently used to interpolate probability values for the whole range of possible assay values. The uncertainty of measurement of a test result was finally defined as the probability of not observing the same qualitative test result when retesting the same sample. For the competitive ELISA any sample with a percent inhibition 4% above the cut-off value had an uncertainty level (probability of a negative result in the case of retest) below 5%. In the indirect ELISA with a cut-off OD of 0.1, the uncertainty was below 5% for any sample with a normalised OD value above 0.22.

The effectiveness of two psychomotor therapy programmes on physical fitness and physical self-concept in nonpsychotic psychiatric patients: a randomized controlled trial.

OBJECTIVE: To compare the changes in cardiorespiratory and muscular fitness, and the changes in physical self-concept after participation in one of two psychomotor therapy programmes in a sample group of psychiatric patients. To study the relationship between the changes in physical fitness and the changes in physical self-concept. DESIGN: Randomized controlled parallel-group trial with repeated measures. SETTING: Three treatment units of a university psychiatric hospital in Belgium. SUBJECTS: One hundred and ninety-nine patients with severe symptoms of depression and/or anxiety, and/or personality disorders. INTERVENTIONS: A general programme of psychomotor therapy, consisting of different forms of physical exercises and relaxation training, and a personalized psychomotor fitness programme, consisting of aerobic and resistance training. These programmes were followed three times a week for a period of 16 weeks. OUTCOME MEASURES: The maximum dynamic strength, the strength endurance, physical work capacity at 60% and 80% of the estimated maximal heart rate reserve, and the physical self-concept by means of the Dutch version of the Physical Self-Perception Profile. RESULTS: After eight weeks, both groups exhibited an improvement in muscular fitness (both p-values < 0.0001), but only the psychomotor fitness group had improved in cardiorespiratory fitness (p < 0.01). After 16 weeks, the patients in the general programme of psychomotor therapy had not increased in cardiorespiratory fitness. At the end of the 16-week programmes, both groups showed a more positive physical self-concept (p from 0.01 to < 0.0001). However, these improvements were not related to the progress in physical fitness. CONCLUSIONS: The main difference in the effectiveness of the two programmes was the increase in cardiorespiratory fitness in the psychomotor fitness group. The gains in fitness did not play an essential role in the enhancement of physical self-concept.

Improvements in physical fitness of non-psychotic psychiatric patients following psychomotor therapy programs.

AIM: To investigate the changes in physical fitness after participation in 1 of 2 psychomotor therapy programs in a sample group of non-psychotic psychiatric patients. EXPERIMENTAL DESIGN: randomized controlled parallel group trial with follow-up measures after 8 weeks and after 16 weeks. SETTING: 3 treatment units of a university psychiatric hospital in Belgium. PATIENTS: 141 (51 males, 90 females) patients with severe depressive and/or anxious symptoms, and/or personality disorders. INTERVENTIONS: patients followed a personalized psychomotor fitness program (PF), consisting of aerobic and resistance training, or a general program of psychomotor therapy (GPMT), consisting of different forms of physical exercises and relaxation training. MEASURES: the maximum dynamic strength, the strength endurance and physical work capacity at 60% and 80% of the estimated maximal heart rate reserve. RESULTS: After 8 weeks it was observed that the PF group enhanced in all parameters of cardio-respiratory as well as muscular fitness; the GPMT group had improved in 7 out of the 9 muscular fitness measurements. At the end of the 16 weeks, both groups had shown an improvement in all of the muscular fitness parameters, but only the PF group had increased in cardio-respiratory fitness. CONCLUSION: In order to improve both muscular and cardio-respiratory fitness in these patients, a balanced personalized training program, which includes aerobic and resistance training, is necessary during a period of at least 8 weeks. The less specific GPMT, when followed for a period of 16 weeks, is sufficient for improving muscular fitness and for maintaining cardio-respiratory fitness.

Long-term protection against bovine leukaemia virus replication in cattle and sheep.

In this report, we have evaluated the ability of two different types of live attenuated bovine leukaemia virus (BLV) variants (BLV DX and BLV 6073) to protect cattle and sheep against a heterologous wild-type BLV challenge. Four months after challenge, the protection of the vaccinated animals was effective in contrast to unvaccinated controls. However, long-term protection (18 months after challenge) was observed only in six out of seven animals, one of the vaccinated cattle being infected 12 months after challenge. A second prospective approach investigated the injection of naked plasmid DNA. Two sheep were injected with plasmid DNA encoding the BLV envelope proteins; the challenge virus infection was delayed but could not be completely abrogated. Our results demonstrate that vaccines based on live attenuated viruses and naked DNA injections are able to delay BLV infection, although complete protection cannot be achieved. In addition, our data cast light onto the need to perform long-term vaccination trials because challenge superinfection can occur even after apparent protection for 12 months.

Epidemiological evaluation of a monoclonal ELISA detecting antibodies against bovine leukaemia virus in serum pools.

Sensitivity, specificity and predictive values of an enzyme-linked immunosorbent assay (ELISA) for detecting antibodies against bovine leukaemia virus (BLV) were evaluated using a representative sample of 145 serum pools, comprising from 3 to 48 individual sera. The sample was constituted according to the frequency distribution of the negative and positive pools analysed during a screening involving the whole cattle population of Belgium. Sensitivity and specificity were estimated to 88.9% and 100% and the predicted negative and positive values were 99.9% and 100%, respectively. These results indicate the use of serum pools is suitable for the detection of BLV infected herds in eradication campaigns.