Hydroxyurea in up to 60 mM concentration did not inhibit growth or DNA synthesis in nonaerated cultures of Streptococcus faecalis ATCC 8043. In contrast, in cultures aerated by shaking already 1 mM hydroxyurea decreased the rate of net DNA synthesis and in higher concentrations of the drug the growth of the total cell mass also slowed down and the number of cells per chain increased from 1-2 to 10. The differential rate of DNA synthesis, but not the growth of the total cell mass, could be restored almost to the control level by adding thymidine to the medium. Thus there are at least two targets for hydroxyurea in the cells of S. faecalis grown in aerated cultures.

• MeSH
• DNA bakterií biosyntéza   MeSH
• Enterococcus faecalis účinky léků   růst a vývoj   metabolismus   MeSH
• hydroxymočovina farmakologie   MeSH
• thymidin farmakologie   MeSH
• vzduch * MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• DNA bakterií MeSH
• hydroxymočovina MeSH
• thymidin MeSH

Haemopoietic stem cells were examined in the blood of mice which had been injected with hydroxyurea. It was observed that the amount of CFU in the blood quickly decreased and after higher doses of hydroxyurea CFU completely disappeared from blood. Since CFU are rather resistant to the killing effect of hydroxyurea, it is assumed that the observed effect is caused either by an interference of hydroxyurea (due to its effect on the blood-forming tissues) with the migration of CFU into blood or by stimulating the removal og CFU from blood.

• MeSH
• faktory stimulující kolonie krev   MeSH
• hematopoetické kmenové buňky účinky léků   MeSH
• hydroxymočovina aplikace a dávkování   farmakologie   MeSH
• injekce intraperitoneální MeSH
• myši MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• faktory stimulující kolonie MeSH
• hydroxymočovina MeSH

Treatment of the Epstein-Barr virus (EBV)-transformed, virus-producer P3HR-1 cell line with hydroxyurea (HU) resulted in increased synthesis of the EBV-specific early antigen (EA) and viral capsid antigen (VCA). The induction was noted already at a 200 mumol/l and reached plateau at a 1500 mumol/l HU concentration. At plateau concentration, the percentage of cells expressing EA and VCA was about 5 times higher than in the absence of the drug.

• MeSH
• aktivace viru účinky léků   MeSH
• antigeny virové biosyntéza   MeSH
• hydroxymočovina farmakologie   MeSH
• kapsida biosyntéza   MeSH
• lidé MeSH
• virové plášťové proteiny * MeSH
• virové proteiny biosyntéza   MeSH
• virus Epsteinův-Barrové účinky léků   růst a vývoj   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antigeny virové MeSH
• Epstein-Barr viral capsid antigen MeSH Prohlížeč
• Epstein-Barr virus early antigen MeSH Prohlížeč
• hydroxymočovina MeSH
• virové plášťové proteiny * MeSH
• virové proteiny MeSH

• MeSH
• buněčné dělení účinky léků   MeSH
• hydroxymočovina terapeutické užití   MeSH
• lidé MeSH
• psoriáza farmakoterapie   MeSH
• replikace DNA účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• hydroxymočovina MeSH

Comparison of double hydroxyurea and hydroxyurea-excess thymidine blockades as synchronizing procedures in cultured L5178Y cells revealed that hydroxyurea mimics the effect of thymidine as regards the degree of the resulting synchrony evaluated by the mitotic index and 3H-thymidine incorporating activity. However, the peaks of the mitotic and 3H-incorporating activity appear later after thymidine than after hydroxyurea blockade and the initial maximum incorporation of 3H-deoxycytidine into DNA was about twice higher in thymidine- than in hydroxyurea-treated cells. On the other hand, the timing of 14C-formate incorporation into purine DNA bases was closely similar in both cell populations.

• MeSH
• buněčný cyklus účinky léků   MeSH
• DNA nádorová biosyntéza   MeSH
• hydroxymočovina farmakologie   MeSH
• inbrední kmeny myší MeSH
• kultivované buňky MeSH
• lymfom metabolismus   patofyziologie   MeSH
• mitóza účinky léků   MeSH
• myši MeSH
• permeabilita buněčné membrány účinky léků   MeSH
• radioizotopy uhlíku MeSH
• thymidin farmakologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• DNA nádorová MeSH
• hydroxymočovina MeSH
• radioizotopy uhlíku MeSH
• thymidin MeSH

We detected DNA repair synthesis by employing hydroxyurea as an inhibitor of DNA semiconservative synthesis in various time schedules of experiments. We came to the conclusion that prolongation of the time interval between [3H]thymidine administration and sacrifice of the animals from 0.5 h to 7.5 h increases the sensitivity of examination. Some artifacts associated with detection of the repair (hydroxyurea-resistant) synthesis of DNA are discussed.

• MeSH
• dimethylnitrosamin farmakologie   MeSH
• hydroxymočovina farmakologie   MeSH
• inbrední kmeny myší MeSH
• játra účinky léků   metabolismus   MeSH
• myši MeSH
• oprava DNA * MeSH
• replikace DNA účinky léků   MeSH
• scintilace - počítání metody   MeSH
• thymidin metabolismus   MeSH
• tritium MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• dimethylnitrosamin MeSH
• hydroxymočovina MeSH
• thymidin MeSH
• tritium MeSH

Activation events induced by lectins in human lymphocyte cultures differed not only in time kinetics of their appearance but were also in a different manner inhibited by hydroxyurea (HU). 4F2 and Tac expression, thermostable sheep erythrocyte rosette formation, cell volume distribution changes and the enhancement of the purine metabolic rate [( 3H]adenine incorporation) induced by PHA, Con A or PWM were not influenced by HU treatment, suggesting G1-phase dependency of these markers. The decrease in the mitogen-induced marker expression after 48 h of incubation with HU can be explained by the unability of activated cells to process the cell cycle, to divide and to become newly positive cells. Mitogen-induced RNA synthesis was partially, DNA synthesis, PWM-induced Ig synthesis and lectin-mediated HLA class II antigen expression were totally inhibited by HU. It holds especially for the DR antigen that its appearance in a polyclonal model of lymphocyte activation occurs in a later (postmitotic G1) phase of the cell cycle. The inhibitory effect of HU on late activation parameters could be removed after washing the cells. Mitogen-activated, HU-treated PBL cultures after removing HU continued cell cycle progression without requirement for further addition of lectin.

• MeSH
• adenin metabolismus   MeSH
• aktivace lymfocytů účinky léků   MeSH
• B-lymfocyty účinky léků   MeSH
• fluorescence MeSH
• hydroxymočovina farmakologie   MeSH
• imunoglobuliny biosyntéza   MeSH
• kultivované buňky MeSH
• lektiny farmakologie   MeSH
• lidé MeSH
• lymfocyty účinky léků   MeSH
• mitogeny MeSH
• thymidin metabolismus   MeSH
• uridin metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• adenin MeSH
• hydroxymočovina MeSH
• imunoglobuliny MeSH
• lektiny MeSH
• mitogeny MeSH
• thymidin MeSH
• uridin MeSH

We have previously found that on average 30% of hematopoietic stem cells (CFU-S) are in the S phase, which is at least three times the value published by others. Therefore, it seemed desirable to investigate the reliability of the methods used to measure the percentage of CFU-S in S phase. Various modifications of the [3H]thymidine suicide were tested and it could be demonstrated that results were not affected by them. Furthermore, results obtained with the [3H]thymidine suicide were compared to those obtained with methods utilizing hydroxyurea to kill CFU-S in S phase. The [3H]thymidine- and hydroxyurea-based methods gave parallel results. The parallel behavior validated all of these methods as reliable indicators of the turnover of CFU-S and presumably other stem cell populations.

• MeSH
• buněčné dělení účinky léků   MeSH
• hematopoetické kmenové buňky účinky léků   MeSH
• hydroxymočovina farmakologie   MeSH
• inbrední kmeny myší MeSH
• myši MeSH
• replikace DNA účinky léků   MeSH
• thymidin farmakologie   MeSH
• viabilita buněk MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• hydroxymočovina MeSH
• thymidin MeSH

Using array technology that allows the simultaneous detection of gene expression of hundreds of genes, four patients with chronic myeloid leukemia (CML) were investigated at diagnosis and after starting administration of hydroxyurea. To detect the gene expression of peripheral blood mononuclears and granulocytes Human Cancer cDNA Array (CLONTECH) with 588 gene probes was used. Gene expression mononuclear and granulocyte profiles of patients at diagnosis were compared with the control profiles. The significant expression changes observed in most patients seemed to be important. Increased expression of c-jun N-terminal kinase 2 (JNK2), integrin alpha E, MMP-8, MMP-9 was detected in both fractions of most patients. In some samples PCNA, HDGF, MAPK p38, CD59 increased expressions were found. Significant down-regulation of expression in patients was detected in genes CDK4 inhibitor A, PURA, notch1 in mononuclears; STAT2, STAT5, RAR-alpha, MCL-1, junB, caspase 4 in granulocytes; CDK6, GADD153, ERBB-3, cadherin 5 in both fractions. Expression profiles detected in patients at diagnosis did not differ markedly from those after one-week treatment with hydroxyurea. Only in a few genes were significant changes after hydroxyurea administration observed and inter-individual expression differences were rather common.

• MeSH
• chronická myeloidní leukemie farmakoterapie   genetika   MeSH
• chronická nemoc MeSH
• dospělí MeSH
• genetická variace MeSH
• hydroxymočovina farmakologie   terapeutické užití   MeSH
• lidé středního věku MeSH
• lidé MeSH
• nádorové proteiny biosyntéza   genetika   MeSH
• protinádorové antimetabolity farmakologie   terapeutické užití   MeSH
• regulace genové exprese u nádorů účinky léků   MeSH
• reprodukovatelnost výsledků MeSH
• sekvenční analýza hybridizací s uspořádaným souborem oligonukleotidů * MeSH
• stanovení celkové genové exprese * MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• hydroxymočovina MeSH
• nádorové proteiny MeSH
• protinádorové antimetabolity MeSH

The changes in hemopoiesis of mice following intraperitoneal administration of dextran sulfate (DS) 24 h before irradiation, as well as the effect of injecting them with hydroxyurea (HU), were analyzed. DS increased the proliferation activity and number of hemopoietic stem cells (CFUs) in the bone marrow. The content of CFUs in the bone marrow and the number of endogenous spleen colonies (ESC) of hemopoietic tissue were higher after irradiation in mice treated with DS than in control groups. The survival rate following a lethal radiation dose was also higher. Injection with HU decreased the number of CFUs in animals injected with DS to the level of controls and suppressed its radioprotective effect.

• MeSH
• dextrany farmakologie   MeSH
• hematopoetické kmenové buňky účinky léků   účinky záření   MeSH
• hydroxymočovina farmakologie   MeSH
• míra přežití MeSH
• myši inbrední C57BL MeSH
• myši inbrední CBA MeSH
• myši MeSH
• radioprotektivní látky farmakologie   MeSH
• síran dextranu MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• dextrany MeSH
• hydroxymočovina MeSH
• radioprotektivní látky MeSH
• síran dextranu MeSH