Structural elaboration of dicyanopyrazine: towards push-pull molecules with tailored photoredox activity.

As an extension of the successful dicyanopyrazine photoredox catalysts, a series of X-shaped push-pull molecules with a systematically altered structure were designed and facilely synthesized; their structure-property relationship was elucidated in detail experimental as well as theoretical calculations. Dicyanopyrazines are proven to be powerful photoredox catalysts with a push-pull arrangement that allows facile property tuning by interchanging a particular part of the D-π-A system. Changing the mutual position of the cyano acceptors and the methoxy, methylthio and thienyl donors as well as modifying the linker allowed wide tuning of the fundamental properties of the catalysts.

[Insufficient formation of interferon in children with recurrent respiratory infections].

The authors investigated the ability of IFN-alpha formation in 50 children followed up on account of frequent and relapsing respiratory diseases. The ability to produce IFN-alpha was consistent with the clinical condition. Children who were frequently ill and whose condition did not improve during the last two years had an inadequate IFN-alpha production.

Deficiency of interferon production in children with recurrent respiratory diseases.

In 50 children followed-up for frequent and repeated respiratory diseases, IFN-alpha production was examined. The ability to produce IFN-alpha correlated with the clinical situation of the children. It was low in children constantly ill and better or even normal in children whose health substantially improved or who were without symptoms during the last two years.

[The role of cellular immunity in the etiopathogenesis of obstructive bronchitis in childhood].

The development and aetiopathogenetic role of the immune response were studied in group of infants and children aged 4-6 years by comparison of clinical status, concentrations of serum immunoglobulins, virological tests (levels of specific antibodies and cultivation of viruses) and the macrophage migration inhibition test. A respiratory syncytial virus was found in 44% of virologically positive children. The macrophage migration inhibition test was positive in 45% of infants suffering from obstructive bronchitis.

Ultrastructure of bronchial epithelium in children with chronic or recurrent respiratory diseases.

The ultrastructure of the bronchial epithelium in three children with recurrent bronchopneumonia, four patients with cystic fibrosis and two with Kartagener's syndrome was studied. The children with recurrent bronchopneumonia and those with Kartagener's syndrome had mostly changes in the pseudostratified ciliated epithelium, and two of them had ultrastructural signs of developing squamous metaplasia. Developed stratified squamous epithelium was found in three of four patients with cystic fibrosis and in one patient with recurrent bronchopneumonia.

A comparison between the efficacy of ketotifen and clemastine in children.

In a controlled single-blind study of 12 weeks' duration the prophylactic anti-asthmatic effects of ketotifen and clemastine in children with bronchial asthma were compared. The drugs were administered in syrup form in doses from 1 to 2 mg per day according to the body-weight. Fifty-seven children, twenty-nine in the ketotifen group and twenty-eight in the clemastine group took part.

[Pathological ultrastructural findings in the epithelium of the respiratory passages in children and adults with repeated and chronic respiratory diseases (author's transl)].

The ultrastructure of the respiratory passages epithelium of children, adolescents and older adults suffering from repeated or chronic respiratory disease was studied in the material obtained as a small excision during bronchoscopy. The findings were classified into 4 groups according to the character of the ultrastructural changes found in the epithelium. In large bronchi was found: I--a completely unaltered pseudostratified columnar ciliated epithelium, II--a pseudostratified columnar epithelium with various signs of pathological alteration, III--an altered pseudostratified columnar epithelium with first ultrastructural signs of the development of squamous metaplasia, IV--a developed stratified squamous epithelium.