Air pollution and molecular changes in age-related diseases.

Assessment of the impact that air contaminants have on health is difficult as this is a complex mixture of substances that varies depending on the time and place. There are many studies on the association between air pollution and increased morbidity and mortality. Before the effect of polluted air is manifested at the level of the organs, an impact can be observed at the molecular level. These include some new biomarkers, like a shortening of the mean telomere length in DNA, dysregulation of gene expression caused by microRNA levels or a variation in the copy number of mitochondrial DNA. These changes may predispose individuals to premature development of age-related diseases and consequently to shortening of life. The common attribute, shared by changes at the molecular level and the development of diseases, is the presence of oxidative stress.

[A rare case of congenital dentin dysplasia in a child aged 8 years]. / Rzadki przypadek wrodzonje dysplazji zebiny u 8-letniego dziecka.

In the reported case the authors observed a considerable mobility of all milk teeth and permanent teeth. The degree of this mobility varied. The crowns of milk and permanent teeth had a normal size, shape and colour. All teeth were unresponsive to thermal and electric stimulation. Radiological examination showed a nearly complete lack of roots and complete absence of pulp chambers and root canals. This was confirmed by histological examinations demonstrating that the inner part of the teeth in the crown and root was filled with hard masses which in light microscopy resembled newly forming compact bone with Haversian structures. The absence of resorption sinuses in the rudimentary roots was noted. Paediatric examination failed to demonstrate any abnormalities.

Column chromatography of tetracyclines and their degradation products.

The improved column chromatographic method has been developed for the determination of tetracycline, oxytetracycline N-pyrrolidinemethyltetracycline, methacycline, doxycycline and their degradation products (anhydro and epi forms) in pharmaceutical preparations. The analyses of 13 commercial preparations showed them to contain certain amounts of degradation products. The most contaminated were preparations containing tetracycline and N-pyrrolidinemethyltetracycline. They contain all of degradation products (anhydro and epi forms). Preparations containing oxytetracycline showed the presence of anhydrooxytetracyline but did not contain the epimer. Preparations containing semisynthetic antibiotics, methacycline and doxycycline, showed only the presence of epimers.