The German multi-centre study on smoking-related behavior-description of a population-based case-control study

Tobacco smoking is a major risk factor for most of the diseases leading in mortality. Nicotine dependence (ND), which sustains regular smoking, is now acknowledged to be under substantial genetic control with some environmental contribution. At present, however, genetic studies on ND are mostly conducted in populations that have been poorly characterized with regard to ND-related phenotypes for the simple reason that the respective populations were not primarily collected to study ND. The German multi-centre study 'Genetics of Nicotine Dependence and Neurobiological Phenotypes', which is funded by the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG) as part of the Priority Program (Schwerpunktprogramm) SPP1226: 'Nicotine-Molecular and Physiological Effects in CNS', was intended to overcome some of these inherent problems of current genetic studies of ND. The multi-centre study is a population-based case-control study of smokers and never-smokers (n = 2396). The study was unique worldwide because it was the first large-scale genetic study specifically addressing ND with the collection of a wide range of environmental, psychosocial and neurobiological phenotypes. Study design and major population characteristics with emphasis on risk prediction of smoking status were presented in this paper.

P50 sensory gating and smoking in the general population

P50 gating is a major functional biomarker in research on schizophrenia and other psychiatric conditions with high smoking prevalence. It is used as endophenotype for studying nicotinic systems genetics and as surrogate endpoint measure for drug development of nicotinic agonists. Surprisingly, little is known about P50 gating in the general population and the relationship to smoking-related characteristics. In this multicenter study at six academic institutions throughout Germany, n=907 never-smokers (NS<20 cigarettes/lifetime), n=463 light smokers (LS) with Fagerström Test for Nicotine Dependence (FTND)≥4 and n=353 heavy smokers (HS, FTND<4) were randomly selected from the general population. As part of a standardized protocol for investigating the genetics of nicotine dependence (ND), an auditory P50 paradigm was applied. The main outcome measure was P50-amplitude difference followed by time-frequency analyses and functional imaging (sLORETA). Reduced P50 gating was found in HS compared to NS with LS taking an intermediate position-correlating with the degree of ND. sLORETA and time-frequency analyses indicate that high-frequency oscillations in frontal brain regions are particularly affected. With growing age, P50 gating increased in (heavy) smokers. This is the first large-scale study (normative sample data) on P50 sensory gating and smoking in the general population. Diminished gating of P50 and associated high-frequency oscillations in the frontal brain region are indications of a deficient inhibitory cortical function in nicotine-dependent smokers. The suitability and application of sensory P50 gating as functional biomarker with regard to genetic and pharmacological studies is discussed.

Treatment costs and quality of life of patients with peripheral arterial occlusive disease--the German perspective

BACKGROUND

To objectify the debate about the restricted resources of the health system, examinations about the treatment costs and quality of life implications of different illnesses are necessary. The aims of the examination were the quantification of costs that are caused by a patient with PAD per year and the determination of the quality of life.

PATIENTS AND METHODS

280 patients (mean 66.6 years) in Fontaine stages II to IV were included in the study to determine their treatment costs for the year 2001 retrospectively from patient records. Health-related quality of life was recorded through the standardized questionnaires PAVK-86, SF-36 and EQ-5D.

RESULTS

A patient with PAD in stage Ila costs on average 1792.45 Euros, in stage IIb 2551.28 Euros, in stage III 4356.48 Euros and in stage IV 6225.89 Euros. The costs of the in-hospital treatment dominated the total result on average with 44.4% of the direct costs. Further cost factors were the drugs with 33.4%, the out-patient medical treatment with 9.9%, the expenditures for care with 6.7%, rehabilitation with 3.6% and adjuvants with a share of 1.9%. The indirect costs played a subordinate role with 9.67% of the total costs. The quality of life was clearly restricted in all stages of the PAD. The quality of life especially was strongly decreased from the Fontaine stage IIb on. The problems were mainly in the areas of the physicalfunctions and pain.

CONCLUSION

The study showed that the treatment of patients with PAD is very cost-intensive and that patients have to suffer from a considerable loss of quality of life.

[Preliminary studies of the immunization of shrimp (Penaeus monodon) against vibrio infections]

There is a great demand for an applicable vaccine against bacterial infections of prawns, especially Vibriosis. The results of the tests that had been carried out can be evaluated as promising and indicate that the vaccination of prawns against bacterial diseases is possible. Nevertheless it is still necessary to increase the scale of research on this subject, above all, the basics of the immuno-system of prawns. Adult prawns should be vaccinated to check if they are able to pass their immuno-protection to their progeny. If that is the case only a few breeding animals have to be vaccinated, instead of all the larvae. Actually the prophylactic application of antibiotics is the only method to prevent infections with Vibriosis. 100-150 mg of Oxytetracycline per kg of prawns are fed during one production period and these antibiotics are also used in humans. Assuming that the average amount of harvested prawns per production unit is 8-10 metric tons/pond (1 ha). 800-1500 g of antibiotics are used. Since different pathogenic strains have developed resistance to Oxytetracycline, also other kinds of antibiotics (for example oxolinic acid) are given today. Antibiotics are often fed until harvesting, however, there are laws which prohibit use to antibiotics during the last thirty days before harvesting, to prevent residues in the prawn body. A vaccine against bacterial diseases could decrease the production costs and reduce the amount of the applied antibiotics.