Cellular expression of interleukin 2 (IL-2) and its receptor (IL-2R, CD25) in lung tumours.

In view of the unclear prognostic and diagnostic role of interleukin 2 (IL-2) and its receptor in human tumours, we examined the cellular expression of IL-2 and of the subunit alpha of its receptor (IL-2Ralpha, CD25) in relation to the proliferative activity of various subtypes of lung tumours. The immunocytochemical ABC technique was applied to archival tissue material of neuroendocrine lung tumours: lung carcinoids, including typical carcinoids (TC), atypical carcinoids (AC) and small-cell lung cancers (SCLC) and squamous cell lung cancers (non-small cell lung cancers, NSCLC). Expression of IL-2 was detected in all types of lung tumours. The highest frequency of IL-2 expression (93%) was noted and the most pronounced semi-quantitatively evaluated expression of IL-2 was detected in AC tumour cells. The expression was more pronounced as compared to neoplastic SCLC (p = 0.01) and NSCLC cells (p = 0.005). The results suggest a negative correlation between IL-2 expression and the proliferative activity of tumour cells (evaluated by expression of Ki-67) in AC. The frequency of detection of IL-2 receptor (IL-Ralpha, CD25) was the highest in NSCLC (94%). Semi-quantitative expression of IL-2R, like that of IL-2, also dominated in the group of atypical lung carcinoids but manifested a significant difference only as compared to typical carcinoids (p = 0.014). Within the groups of tumours studied no correlation could be detected between cellular expressions of IL-2 and IL-2R. Our results demonstrate variable expression of IL-2 and its receptor in various types of lung tumours, but no simple relationship could be detected between tissue expression of the markers and proliferative activity. Appraisal of the diagnostic and/or prognostic significance of the results requires further study.

Children as a sensitive subgroup and their role in regulatory toxicology: DGPT workshop report.

There is increasing discussion that children might be considered as a specific subgroup in public health regulations which could be more sensitive than the average "adult" human being. Differences between children and adults, with regard to susceptibility towards toxicants, may result from a combination of toxicokinetic, toxicodynamic and exposure factors. Kinetic factors are of importance mainly in the early postnatal period, largely as the result of immature elimination systems, i.e. metabolising enzymes and/or renal function. Specific vulnerability may prevail during several time periods, related to the development and maturation of organs (for example, brain, bone, endocrine system). For some substances, it has been shown that children at a specific age are less sensitive than adults. Specific exposures of toddlers to environmental chemicals may be high due to their moving behaviour and hand-to-mouth activities. Existing scenarios and models for exposure of children should be improved, in particular with respect to different ages. The outcome of model calculations must be verified by human biomonitoring analysis. At present, there is ongoing discussion of toxicological test models suitable to delineate human postnatal development. Experience with infant-orientated test systems is scarce (for example in developmental neurotoxicity). In general, tools for predicting toxicological sensitivity of children must be further improved. Regulators should also be aware that reduction of lifestyle-related toxic exposures such as smoking and drug abuse in children and adolescents is now an increasing public health problem in many countries.

[Respiratory problems in children after severe pneumonia]. / Problemy oddechowe u dzieci po przebytym zapaleniu pluc o ciezkim przebiegu.

In the course of complicated pneumonia in children diffuse inflammatory infiltrations with the risk of durable destruction of lung parenchyma are confirmed clinically and radiologically. The aim of the study was an evaluation of the general health state and respiratory problems in 55 children who had been earlier hospitalized for pneumonia with signs of localized changes and severe symptoms. The evaluation was done 2-10 years after the onset of the disease. In 89.1% of children a planned treatment was continued after hospital discharge. The period of recovery lasted over 6 weeks in 50.8% of examined children, and it was shorter than 2 weeks only in 23.6% of children. The relapses of the lower respiratory tract inflammation occurred in 43.6% of children in the form of bronchitis and in 9.1% of children a recurrent pneumonia was diagnosed. Only 12.7% of children needed subsequent hospitalization for respiratory problems. In 34.5% of children a limitation of physical activity was noted. 40 children underwent a functional examination of the respiratory system. In this group 35% of children ventilation problems of restrictive character were stated, whereas in 17.5% spirometry revealed bronchial obstruction. Presented results suggest the necessity of the specialistIc care of children after severe pneumonia including the monitoring of clinical and spirometric parameters of respiratory function and adequate rehabilitation.

The utility of two rodent species in carcinogenic risk assessment of pharmaceuticals in Europe.

For the past 20-30 years, lifespan carcinogenicity studies for pharmaceuticals have been required to be carried out in two rodent species. Due to scientific progress, the necessity/justification of lifespan studies in two species for the assessment of carcinogenic risk of pharmaceuticals is currently under discussion. A study in one species (either rat or mouse) might suffice. To appraise the need for a study in a second species, a database was compiled of all pharmaceuticals tested for carcinogenicity for which a marketing authorization was applied for in Germany and The Netherlands since 1980. The incidence of treatment-related tumor findings was determined in either rat or mouse or in both. Tumor findings occurred for nearly 50% of all compounds, with the rat being more sensitive than the mouse. Specific attention was given to the question whether tumor findings in mice ever caused the regulatory authorities to refuse registration, to restrict the proposed therapeutic indication of a pharmaceutical, or to apply a cautionary label. It was found that no tumor findings in mice alone ever led to such a regulatory action. In addition, whether mouse studies had been important in interpreting the results of rat studies was determined. A negative mouse study (no tumors found) was rarely used to declare the rat findings irrelevant to humans. A mechanistic explanation was used as a much more important argument in the assessment of tumor findings in rats. In case of transspecies findings, the target organs were the usual ones, such as lung and liver, or the tumors occurred as a result of an exaggerated pharmacodynamic action expected from the pharmacology of the compound. The results of the database thus question the need of maintaining the requirement of rodent carcinogenicity studies in two species.