Nordisk medicin最新文献

The treatment of HIV infection in the industrialised countries has undergone manifest changes during the past decade. Since the advent of zidovudine in 1987, the first agent capable of delaying disease progression, several other nucleoside analogues have been introduced, though in retrospect the effect of these drugs can now be seen to have been moderate. With the introduction of proteinase inhibitors, more effective control of infection became possible, and the combination of a proteinase inhibitor with two nucleoside analogues yielded a triple-drug treatment capable of halting progression for a large proportion of patients. Thus, during recent years the disease course has changed in character from successive deterioration of the immune defence system to a condition where most patients can live virtually normal lives in many respects. For some patients, however, the new drugs have been associated with side effects, and our knowledge of the long-term effects is still insufficient.

With the radionuclide tracers available today, 50-90 per cent of neuroendocrine tumours of the gastro-intestinal tract can be visualised with PET (positron-emission tomography). PET also enables the effect of tumour treatment to be monitored in terms of biochemical and functional variables, which is not possible with other radiological techniques. Owing to the very good tumour resolution possible with PET, it serves as a complement to other routine methods such as computed tomography and ultrasonography, and can be used to screen the chest and abdomen for small primary tumours that can not be detected with other methods. In several pre-operative trials PET has been shown to demonstrate more changes in the pancreas and liver than was possible with other methods. In the near future it will be possible to demonstrate the presence of and quantify growth factor receptors, hormones, enzymes, DNA synthesis, mRNA synthesis and protein synthesis. Access to these tumour biological data will be of crucial importance to the individualisation of treatment.

Positron emission tomography has developed very much since the start in the late 1970s, especially with the development of new labelling procedures for PET-tracers. With the development of whole body imaging and the discovery that 18F-FDG allows a high sensitivity for the detection of soft tissue tumors, the clinical use has increased remarkably. The cost-effectiveness of this modality, when properly used, has been demonstrated and 18F-FDG-PET should be considered as an early alternative in patient evaluation.

The most important preventive measures against accidental HIV infection in health care are the education of personnel and the observance of routine procedures in everyday work. In this way, the accidental infection rate can be reduced by more than 50 per cent. Consistent registration of the causes of accidental infection can further reduce work-related risks. In January, the Danish authorities issued guidelines for the use of antiviral chemoprophylaxis against HIV infection following occupational exposure. A four-week course of triple-drug anti-retroviral prophylaxis is recommended to prevent HIV infection in causes of needle-stick or other penetration injuries.

In order to grow beyond 2-3 mm in size, a primary tumour or metastasis must induce angiogenesis, the formation of new blood vessels. Tumour capillary content is an independent prognostic factor, usually measured as the mean of three counts in capillary-rich areas of the histological section. Either as single drugs or in combination with other treatment, angiostatic agents probably represent the future of cancer treatment.

The purpose of this work is to address future possibilities for avoiding cancer. We elucidate the most important known causes of cancer in the Nordic countries during the second half of this century and provide estimates of the numbers of cancer cases that might be avoided by the year 2000 if those causes were effectively eliminated. Information on the pattern of carcinogenic exposures in each of the five Nordic countries and the associated relative risk estimates from the scientific literature were obtained. The numbers of avoidable cancers were assessed on the basis of this information together with the associated population attributable risk percent, PAR%, i.e. the proportion of a given cancer that can be avoided upon elimination of the causative factor. The main causes of cancer include smoking, alcohol consumption, exposure to occupational carcinogens, radiation, obesity and infection with human papillomavirus (HPV) and Helicobacter pylori. Annually, more than 18,000 cancers in men and 11,000 in women in the Nordic populations could be avoided by eliminating exposure to known carcinogens which is equivalent to 33 percent and 20 percent of all cancers arising in men and women, respectively, around the year 2000. Smoking habits account for a little more than half of these avoidable cases. Exposure to solar radiation, HPV and Helicobacter pylori, diagnostic and therapeutic radiation and consumption of alcohol play important roles in the causation of cancer, as each of these factors is linked with 1-5 percent of all cancers in men and women. Occupational exposures are also substantial causes in men (3 percent), and obesity is important in women (1 percent). In contrast, current knowledge is insufficient to give reliable estimates of the numbers of cancers that could be avoided by well-described modifications of dietary habits. These figures indicate that the most efficient way of reducing cancer morbidity would be to reduce the prevalence of exposure of the population to cancer-causing agents.

A successful model of liaison between the primary and secondary (hospital) levels of health care entails improved co-operation between hospital doctors and general practitioners (GPs). Since its introduction in Denmark in 1991, this approach has been adopted in Sweden and, to a lesser extent, in Norway. Important principles of the model include: 1) both at the primary and secondary level, responsibility for cooperation rests with the physicians themselves; 2) all physicians at both levels are involved; 3) liaison is maintained by selected GPs serving as liaison officers acting in concert under the guidance of a coordinator; 4) liaison officers are responsible for cultivating personal contacts and good relations at hospitals, and promoting interest in and commitment to the system. Evaluation of the model requires both quantitative and qualitative studies. Although few evaluations have been completed, and no definite conclusions can be drawn, the preliminary results of current evaluations in progress in Sweden and Norway are promising, as are the reported experiences of those who use the system. A Nordic ad hoc group has been actively engaged in promoting the quality of primary-secondary health care liaison since 1997.

The Nordic Cancer Registries have completed a long-term project designed to evaluate developments in cancer up to the year 2010. On the basis of trends hitherto discernible, the development of cancer morbidy and mortality in the Nordic countries was projected. Another aim was to investigate the manner in which the trend of increasing cancer incidence might be modified by preventive measures, early diagnosis and optimised treatment.

Suppressor genes is the collective term for genes that regulate growth control. Inactivation of both copies may promote malignant transformation, though usually only in the presence of other mutations. The distinction between suppressor genes and other genes of importance to the development of malignancy is not clear cut. Suppressor genes may be activated genetically or somatically. In the latter case, mutations may occur before, during or after malignant transformation, and will determine the cancer phenotype and thus its clinical manifestations.