Recognition of environmental and genetic effects on barley phenolic fingerprints by neural networks.

Through computational analysis of high-performance liquid chromatography (HPLC) traces we find correlations between secondary metabolites and growth conditions of six varieties of barley. Using artificial neural networks, it was possible to classify chromatograms for which the varieties were fertilized by nitrogen and treated by fungicide. For each variety of barley we could also differentiate it from the others. Surprisingly, all these classification tasks could be solved successfully by a simple network with no hidden units. When adding to the methodology pruning of the network weights, we were able to reduce the set of peaks in the chromatograms and obtain a necessary subset from which the growth conditions and differentiation may be decided. In some instances, more complex networks with hidden units could lead to a further reduction of the number of peaks used. In most cases, far more than half of the peaks are redundant. We find that it requires fewer information-rich peaks to perform the variety differentiation tasks than to recognize any of the growth conditions. Analysis of the network weights reveals correlations between weighted combinations of peaks.

Distribution of RAPD markers on a linkage map of barley.

The RAPD technique was found to provide reliable genetic markers in barley. A linkage study of 23 RAPDs, 28 RFLPs, and 29 gene loci was conducted on 72 chromosome-doubled haploid progeny lines from a barley cross. The resulting linkage map covered 680 cM, about half of the barley genome. RAPD markers were distributed throughout the map, but a higher than expected frequency of tightly linked RAPDs was observed. Several cases of skewed segregation ratios were observed, but the RAPD markers segregated in ratios similar to their linked loci, confirming that they were reliably scored. In separate crosses, two amplified RAPD products, generated by different primers, were shown to reside in corresponding chromosomal positions. The RAPD markers seem a realistic alternative to RFLP markers in linkage analysis of barley.

Dextropropoxyphene deaths in Denmark from the health authority point of view.

All known deaths resulting from poisoning with Dextropropoxyphene (n = 234) in the Municipality of Copenhagen during the period 1982 to 1989 were surveyed. The deaths were found to have occurred in a group characterized by social stress and abuse. A decline was observed in the annual number of deaths after 1985. The influence that the health authorities efforts and debates in the professional press had with regard to this development are discussed. Furthermore, it is recommended that more explicit criteria as to how the cause of death is to be determined in the future should be compiled.

Severe low-back pain. I: Clinical assessment of two weeks conservative therapy.

A standard clinical examination was performed by two independent investigators, before and after two weeks of conservative therapy, on 33 patients with severe low-back pain. Kappa coefficients indicated a higher reproducibility of neurological tests than of e.g. muscular tenderness or scoliosis. All patients were diagnosed by CT-scan and a disc herniation was found in 20. The clinical diagnosis was more in agreement with the CT-diagnosis after than before treatment. By discriminant analyses six variables were found to classify the clinical diagnosis correctly in 32 of the 33 patients: sensory loss, ankle jerk, soreness of back extensors, lumbosacral soreness, radiating pain and back extension test. Similarly, the CT-diagnosis was classified in 25 of 33 patients by the variables: sensory loss and limping.

Severe low-back pain. II: Changes in CT scans in the acute phase and after long-term observation.

No significant changes were noted in the CT-scan before and after 14 days of conservative therapy for low-back pain. Twenty of 33 patients had a disc herniation diagnosed on CT, and of these 18 patients were re-scanned after two weeks. Twelve patients were subsequently treated surgically, and of the remaining 8 patients 6 were re-scanned after 18 months. At this time the disc herniation had diminished significantly and was located in a more median position. In the 8 conservatively treated patients, the pain score at follow-up was related to the original size of the herniation (r = 0.72, p < 0.05).

The correlation between general disease prevention and prevention of HIV-contagion among adolescents.

A representative group of young persons (N = 745), who used the youth clubs in Copenhagen were asked to fill in a structured questionnaire. A large group of the young had had their sexual debut (N = 367). In respect of this group we found no correlation between prevention regarding general health risk factors vs. prevention against HIV contraction. It is discussed as to whether this difference can be accepted as an expression of the fact that adolescents do not consider the risk of AIDS as something that can affect them. Similarly, current problems in the chain of knowledge, attitude and behaviour in relation to intervention programmes are also discussed, including ethical aspects.

[Standardized treatment]. / Standardiseret behandling.

Treatment protocols have not been well-defined, and may comprise anything from mere instructions regarding simple procedures to guide-lines for the treatment of the whole course of a disease. The discussion about treatment protocols has continued on since the 70's, and the system has been introduced into the Health Service of a number of countries. Those in favour of the programmes have focused, in particular, on the economic advantages and the advantage of achieving a certain quality of treatment, while those opposing the programmes insist that clinical freedom is at stake. We have found, especially via literature studies, that little knowledge is available as to what extent treatment protocols or case management protocols are employed, e.g., in Sweden and the USA where there have been a number of advocates of these systems. We have only been able to find two evaluation studies of more comprehensive programmes. In these two studies, the total expenditure for treatment was not clearly reduced, and as there were no well-defined parameters for quality of care, it has not been possible to demonstrate any improvement in the quality itself. It is, of course, possible that the discussion in respect of treatment protocols has indirectly had an effect on clinical thought, including those countries where these systems have not been introduced.

The influence of prolonged stable methadone maintenance treatment on mortality and employment: an 8-year follow-up.

A cohort of 169 opiate drug addicts was followed for 8 years. The mortality rate was 3.3 per year. The average lethality per observation year was found to be higher than in other studies. The treatment with methadone was unstable and only 11% had received stable prolonged maintenance treatment. It is not possible to reject a model that described increasing mortality rates neither as a function of falling methadone maintenance treatment nor as a function of socially unstable addicts contra stable addicts. Unemployment was high in the cohort (87%), and no relationship could be demonstrated between methadone maintenance treatment and employment.

The allocation of drug addicts to different types of treatment. An evaluation and a two-year follow-up.

In Denmark the official aim has been to reduce methadone treatment, even though no effort is made to directly forbid this therapy. A multiprofessional committee was established to regulate and limit methadone treatment. There were no specific guidelines for what type of drug addict should be treated with methadone. We found that allocation for the Regional Narcotic Committee of the Municipality of Copenhagen during 1982-1984 did not serve the desires of the addicts because only 41% followed it. Allocation also did not follow the principles of research in this field. In a 2-year follow-up investigation we found that drug addicts had a mortality rate of 6.3/year, rising criminality (significant), and falling availability to the labor market (nonsignificant). We therefore came to the conclusion that the efforts of the committee did not improve the conditions of drug addicts. Only those drug addicts who had been under almost constant methadone treatment had a low lethality and a falling number of criminal convictions (significant). Finally, it is concluded that limited research within this field prevents more specific treatment and improved use of financial resources.

A statistical analysis of the seasonality in sudden infant death syndrome.

Sudden Infant Death Syndrome (SIDS) has a characteristic peak incidence in the winter months and a peak incidence at the age of two to four months. The present study examines whether the seasonality is related to the time of birth-the time of death or both. The data for the study relates to 116 cases of SIDS, representing 95% of all registered cases of SIDS in eastern Denmark in a three-year period 1981 to 1983. They were all autopsied at the Institute of Forensic Medicine in Copenhagen and evaluated by the same people. The framework of the analysis is a multiplicative Poisson-model with three sets of parameters describing the effects of the age of the infant, the time of death and the time of birth. The analysis proved the seasonality related alone to the time of death. An identical analysis was performed for 123 infants who in the period 1973-83 in eastern Denmark died from infectious diseases. In these cases no significant effect of the month of birth or the month of death was shown.