Wynik wyszukiwania w bazie Polska Bibliografia Lekarska GBL
Liczba odnalezionych rekordów:
Przejście do opcji zmiany formatu
Wyświetlenie wyników w wersji do druku
Biological rhythms and behavior - then and now.
Med. Sci. Monitor 2002: 8 (9) s.SR27-SR30, il., bibliogr. 6 poz.
Hasła klasyfikacyjne GBL:
Background: Living matter has its own 'biological time': a set of rhythmic oscillations, paced by genes whose expression varies over regular cycles. The resulting chronomes, or time structures, are usually studied in living matter. A human chronome is preserved long after death in the structure of tooth enamel. This fossil record can be compared with contemporary enamel thus providing insight into an ancient biological rhythm, and consequently into behavior in pre-historic civilizations. Material/Methods: Eight adult 3rd molar teeth from human burials in Atacama oases of Northern Chile, dating from AD 400 to 900 and belonging to the pre-Hispanic San Pedro culture, were compared to 20 discarded contemporaneous teth from Albuquerque, N. M. USA. Two adjacent, 100 ćm thick ground sections from each tooth were examined using a stereoscopic dissecting microscope and polarized light. The intervals between consecutive brown striae of Retzius (TBS) and the width of the enamel were measured. We recorded the the number of TBS and the number of Wilson's bands and calculated a ratio of enamel with/number of TBS for each section. We used ANOVA for statistical analysis and cosinor methodology for chronomics, time structure (chronome) mapping. Results: The 'biological week' in the chronome (time structure) of ancient enamel, gauged by TBS, varied according to a multiseptan (multiple of seven) component faster than did the multiseptan of contemporaneous teeth (1/2.7 versus 1/4.6 biological weeks). Conclusions: Until now no human chronome has been isolated from fossilized structures. Our discovery indicates that behavior of ancient populations, such as rest and work spans, can be deduced to some extent after millennia.
Clinical and pharmacokinetic study of fractionated doses of oral etoposide in pediatric patients with advanced malignancies.
Med. Sci. Monitor 2002: 8 (9) s.PI70-PI77, il., tab., bibliogr. 31 poz.
Hasła klasyfikacyjne GBL:
dzieci 2-5 r.ż.
dzieci 6-12 r.ż.
dzieci 13-18 r.ż.
Background: The purpose of this phase I study was to evaluate the toxicity profile, dose-limiting toxicities (DLT), maximum tolerated dose (MTD), and plasma pharmacokinetics of oral etoposide, and to recommend a safe fractionated dose for phase II trials in pediatric patients with refractory solid tumors. Material/Methods: All patients had tumors no longer amenable to established forms of treatment. The initial dose of etoposide was 20 mg/mý TID for 14 days every 21 days (dose-level I). Etoposide plasma pharmacokinetics were studied on day 1 of treatment and determined by PHLC. Results: Seventeen children were enrolled, 13 of whom were included in the pharacokinetic study, for a total of 64 courses. nine patients were included at dose-level I; grade 2-3 leucopenia was observed in 5. The dose was then raised to 25 mg/mý (dose-level II) in another 8 patients; grade 3-4 leucopenia was observed in 4. This dose-level was therefore considered the MTD. The DLT was neutropenia. In patients at dose-level I and II the maximum plasma etoposide concentration was 2.97 and 8.59 ćg/ml, respectively. Drug levels 1 ćg/ml were maintained for about 6.3 hours following drug administration at both dose-levels. Partial response was observed in 1 patient and 4 patients showed stable disease. Conclusions: Prolonged oral etoposide was well tolerated by our patients. Considering the MTD, and fact that the patients included at dose-level I achieved an adequate ( 1 ćg/ml) plasma concentration of etoposide for a sufficient time, this dose level was recommended for phase II studies in pediatric malignancies...
z abstraktem i deskryptorami