• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 13
  • 5
  • 4
  • 2
  • 1
  • Tagged with
  • 30
  • 30
  • 10
  • 9
  • 7
  • 6
  • 6
  • 5
  • 5
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Do the new signal transduction modulators have activity in vitro in tumor cells from ovarian carcinoma and lymphoma?

Lundin, Desiré January 2005 (has links)
During the last decades, chemotherapy with cytotoxic drugs has played a significant role in cancer therapy. It’s important to develop new anticancer drugs, and drug sensitivity testing in vitro can be used to find the right diagnosis for the newly developed substances. The aim of this study was to investigate the cytotoxic activity of the new signal transduction modulators bortezomib, gefitinib and PKC412. The well-established substances cisplatin, cytarabine, doxorubicin and vincristin were investigated for comparison. The activity of the cytotoxic drugs was analysed in human tumor samples from patients with ovarian carcinoma (n=16) and lymphoma (n=15) by using the Fluorometric Microculture Cytotoxicity Assay (FMCA). The testing of cellular drug resistance by FMCA was accomplished successfully in 33 out of the 34 samples (97%). The results of this study indicated that the activity of cytotoxic drugs in tumor cells obtained from patients with ovarian carcinoma and lymphoma may be detected by the FMCA. It also suggested that bortezomib and gefitinib could represent promising agents for treatment of ovarian carcinoma and that PKC412 might be of less use for patients with this diagnose.
12

Patterns of cancer cell sphere formation in primary cultures of human oral tongue squamous cell carcinoma and neck nodes

Saleem, Saira, Jamshed, A., Faisal, S., Hussain, R., Tahseen, M., Loya, A., Sutton, Chris W. 04 December 2014 (has links)
Yes / Recently a sub-population of cells with stem cell characteristics, reported to be associated with initiation, growth, spread and recurrence, has been identified in several solid tumors including oral tongue squamous cell carcinoma (OTSCC). The aim of our pilot study was to isolate CD44+ cancer stem cells from primary cultures of OTSCC and neck node Level I (node-I) biopsies, grow cell spheres and observe their characteristics in primary cultures. Parallel cultures of hyperplastic lesions of tongue (non-cancer) were set up as a control. Immunohistochemistry was used to detect CD44/CD24 expression and magnetic activated cell sorting to isolate CD44+ cell populations followed by primary cell culturing. Both OTSCC and node-I biopsies produced floating spheres in suspension, however those grown in hyperplastic and node-I primary cultures did not exhibit self-renewal properties. Lymph node metastatic OTSCC, express higher CD44/CD24 levels, produce cancer cell spheres in larger number and rapidly (24 hours) compared to node negative OTSCC (1 week) and non-cancer specimens (3 weeks). In addition, metastatic OTSCC have the capacity for proliferation for up to three generations in primary culture. This in vitro system will be used to study cancer stem cell behavior, therapeutic drug screening and optimization of radiation dose for elimination of resistant cancer cells. / SKMCH&RC, Yorkshire Cancer Research
13

Studium biologické aktivity alkaloidů izolovaných z Fumaria officinalis L. (Fumariaceae) II. / Study of biological activity of alkaloids isolated from Fumaria officinalis L. (Fumariaceae) II.

Malý, Lukáš January 2014 (has links)
Malý, L.: Study of biological activity of alkaloids isolated from Fumaria officinalis L. (Fumariaceae) II. Diploma Thesis, Charles University in Prague, Faculty of Pharmacy in Hradec Králové, Department of Pharmaceutical Botany and Ecology, Hradec Králové 2014, 49 pp. Obtained diethylether extract of Fumaria officinalis L. was separated to fractions in column chromatography with petrol, chloroform and ethanol. Preparative TLC and crystalisation led to isolation of five alkaloids from fraction. Alkaloids were identified by GC-MS and NMR specters, optical rotation and melting point as protopine, cryptopine, (-)-fumaricine, (+)-fumariline and (+)-parfumidine. Isolated alkaloids were tested for their inhibition activity towards acetyl- and butyrylcholinesterase and towards prolyloligopeptidase. Activities were compared with standards. Natural inhibitor galanthamine showed IC50 AChE 1.710 ± 0.065 µM, IC50 BuChE 42.30 ± 1.30 µM. Best inhibition activity showed protopine (IC50 AChE 345.4 ± 24 µM, IC50 BuChE 239.6 ± 22.3 µM) and cryptopine (IC50 AChE 477.71 ± 47.33 µM, IC50 BuChE 270.82 ± 39.12 µM). The highest prolyloligopeptidase inhibition activity showed (+)-parfumidine with IC50 POP 99.2 µM, which was more active than used natural inhibitor baicaline (IC50 POP 605.9 ± 0.021 µM). Synthetic POP...
14

Studium biologické aktivity alkaloidů izolovaných z Fumaria officinalis L. (Fumariaceae) I. / Study of biological activity of alkaloids isolated from Fumaria officinalis L. (Fumariaceae) I.

Kostelník, Jan January 2014 (has links)
Kostelník, J.: Study of biological activity of alkaloids isolated from Fumaria officinalis L. (Fumariaceae) I. Diploma thesis, Charles University in Prague,Faculty of Pharmacy in Hradec Králové, Department of Pharmaceutical Botany and Ecology, Hradec Králové 2014, 63 p. The aim of this study was to isolate alkaloids from joined fraction no. 55-67 (A2) obtained from the total alkaloid fraction of extract of Fumaria officinalis L. (Fumariaceae) plant. Using chromatography methods three alkaloids were isolated and then identified by structural analysis (GC-MS, NMR). Three alkaloids were isolated by using common chromagografic methods and then identified by structural analyses optical rotation and melting point as (-)-O- methylfumarophycine, (-)-sinactine a (-)-stylopine. Inhibitory activity of isolated alkaloids was assessed against human erythrocyte acetylcholinesterase, human butyrylcholineesterase and prolyl oligopeptidase. The results were expressed as IC50 values ((-)-stylopine: IC50 AChE and IC50 BuChE > 1000 μM, IC50 POP > 1000 mM; (-)-O-methylfumarophycine: IC50 AChE = 963.10 ± 135.98 µM, IC50 BuChE = 1771.0 ± 380.94 µM, IC50 POP - unmeasured; (-)-sinactine IC50 AChE = 632.0 ± 68.12 µM, IC50 BuChE = 8154.3 ± 981.42 µM, IC50 POP = IC50 POP = 52.9 ± 1.8 µM). None of alkaloids isolated showed...
15

"Estudo da expressão das proteínas PTEN e Akt em células derivadas de carcinoma epidermóide bucal em câmara de invasão" / Study of expression of PTEN and Akt protein in OSCC cell lines submitted to in vitro assay method.

Capuano, Ana Carolina Thome 30 January 2006 (has links)
PTEN é um gene supressor de tumor, que resulta na proteína citoplasmática de mesmo nome, e possui a capacidade de modular a apoptose e o ciclo celular, assim como de inibir a migração celular. Por outro lado, o oncogene Akt promove a sobrevida celular e impede a apoptose. A ativação de Akt é inversamente relacionada com a ausência de PTEN em uma variedade de neoplasias malignas. Neste estudo, linhagens celulares derivadas de carcinoma epidermóide bucal (HN6, HN30, HN31 e uma linhagem de células controle, HaCat) foram submetidas ao método de invasão in vitro e clones celulares altamente invasivos foram isolados. Através das técnicas de imunofluorescência e Western blot foi verificada a expressão de ambas as proteínas nos novos clones (denominados HN6.1, HN30.1, HN31.1 e HaCat.1) e comparada às linhagens controle. A técnica da zimografia também foi realizada, desde que várias metaloproteinases (MMPs) têm demonstrado possuir papel importante no processo de invasão e metástase dos CEB. Nossos resultados revelaram que todas as linhagens celulares e seus respectivos clones invasivos mostraram marcação citoplasmática e nuclear para PTEN e pAkt, respectivamente. A exceção foi a HaCat.1 que apresentou marcação predominantemente citoplasmática para pAkt. A análise do Western blot revelou que os clones invasivos expressam menor quantidade de PTEN, não significantes estatisticamente. Essa diminuição foi expressiva somente na linhagem HaCat.1 (p<0.05). Em relação ao pAkt, foi observado uma discreta superexpressão dessa proteína nas linhagens invasivas de CEB. Contrariamente, a linhagem HaCat.1 sofreu uma significante diminuição de pAkt (p<0,05). Finalmente, a zimografia mostrou um discreto aumento de MMP-2 latente e/ou um significante aumento de MMP-9 ativa em todos os clo nes invasivos. Nossos resultados sugerem que não há uma relação inversa consistente e significativa entre as proteínas PTEN e Akt no processo de invasão in vitro com células derivadas de CEB. Não há somente um padrão de sinalização PTEN-PI3K-Akt no processo de carcinogênese desta neoplasia. A linhagem celular HaCat.1 se comportou diferente das linhagens derivadas de CEB e provavelmente sofreu diferenciação. Um aumento estatisticamente significante de secreção de MMP-9 ativa foi observado em 2 das 3 linhagens de CEB estudadas / PTEN is a tumor suppressor gene that encodes a dual phosphates protein capable to modulate apoptosis and cell cycle and prevent cellular migration. On the other hand, Akt oncogene promotes both cell cycle progression and inhibits apoptosis. Akt activation is inversely correlated with PTEN lost in a variety of cancers. In this study, highly invasive clones of OSCC cell lines (HN6, HN30, HN31 and a control cell line, HaCat) were isolated using an in vitro assay method. The expression of both proteins in these cells was compared by immunofluorescence and western blot technique. The metalloproteinase activation was analyzed by gelatin zimography, since several MMPs have been shown to play an important role in the invasion and metastasis of OSCC. All OSCC cell lines and its new clones showed cytoplasmatic and nuclear staining for PTEN and pAkt, respectively. The western blot analysis revealed no significant decrease of PTEN expression in the most invasive clones (named HN6.1, HN30.1 and HN31.1). Only HaCat.1 had a significant decrease (p<0,05). However, there was no significant increase of Akt in the invasiveness clones and oppositely the expression of Akt was strongly reduced (p<0,05) in the HaCat.1. Finally, the zimography showed a discrete increase of inactive MMP-2 and/or a significant increase of active MMP-9 in all the most invasive cell lines. In conclusion, no correlation was seen between PTEN and pAkt in the process of invasion in vitro. There is not only a linear PTEN-PI3K-Akt pathway in OSCC. The HaCat.1 had a different behavior in relation to OSCC cell lines and probably allowed cellular differentiation. In addition, a significant increase of active MMP-9 was seen in 2 of 3 lines of cells derived from OSCC
16

"Estudo da expressão das proteínas PTEN e Akt em células derivadas de carcinoma epidermóide bucal em câmara de invasão" / Study of expression of PTEN and Akt protein in OSCC cell lines submitted to in vitro assay method.

Ana Carolina Thome Capuano 30 January 2006 (has links)
PTEN é um gene supressor de tumor, que resulta na proteína citoplasmática de mesmo nome, e possui a capacidade de modular a apoptose e o ciclo celular, assim como de inibir a migração celular. Por outro lado, o oncogene Akt promove a sobrevida celular e impede a apoptose. A ativação de Akt é inversamente relacionada com a ausência de PTEN em uma variedade de neoplasias malignas. Neste estudo, linhagens celulares derivadas de carcinoma epidermóide bucal (HN6, HN30, HN31 e uma linhagem de células controle, HaCat) foram submetidas ao método de invasão in vitro e clones celulares altamente invasivos foram isolados. Através das técnicas de imunofluorescência e Western blot foi verificada a expressão de ambas as proteínas nos novos clones (denominados HN6.1, HN30.1, HN31.1 e HaCat.1) e comparada às linhagens controle. A técnica da zimografia também foi realizada, desde que várias metaloproteinases (MMPs) têm demonstrado possuir papel importante no processo de invasão e metástase dos CEB. Nossos resultados revelaram que todas as linhagens celulares e seus respectivos clones invasivos mostraram marcação citoplasmática e nuclear para PTEN e pAkt, respectivamente. A exceção foi a HaCat.1 que apresentou marcação predominantemente citoplasmática para pAkt. A análise do Western blot revelou que os clones invasivos expressam menor quantidade de PTEN, não significantes estatisticamente. Essa diminuição foi expressiva somente na linhagem HaCat.1 (p<0.05). Em relação ao pAkt, foi observado uma discreta superexpressão dessa proteína nas linhagens invasivas de CEB. Contrariamente, a linhagem HaCat.1 sofreu uma significante diminuição de pAkt (p<0,05). Finalmente, a zimografia mostrou um discreto aumento de MMP-2 latente e/ou um significante aumento de MMP-9 ativa em todos os clo nes invasivos. Nossos resultados sugerem que não há uma relação inversa consistente e significativa entre as proteínas PTEN e Akt no processo de invasão in vitro com células derivadas de CEB. Não há somente um padrão de sinalização PTEN-PI3K-Akt no processo de carcinogênese desta neoplasia. A linhagem celular HaCat.1 se comportou diferente das linhagens derivadas de CEB e provavelmente sofreu diferenciação. Um aumento estatisticamente significante de secreção de MMP-9 ativa foi observado em 2 das 3 linhagens de CEB estudadas / PTEN is a tumor suppressor gene that encodes a dual phosphates protein capable to modulate apoptosis and cell cycle and prevent cellular migration. On the other hand, Akt oncogene promotes both cell cycle progression and inhibits apoptosis. Akt activation is inversely correlated with PTEN lost in a variety of cancers. In this study, highly invasive clones of OSCC cell lines (HN6, HN30, HN31 and a control cell line, HaCat) were isolated using an in vitro assay method. The expression of both proteins in these cells was compared by immunofluorescence and western blot technique. The metalloproteinase activation was analyzed by gelatin zimography, since several MMPs have been shown to play an important role in the invasion and metastasis of OSCC. All OSCC cell lines and its new clones showed cytoplasmatic and nuclear staining for PTEN and pAkt, respectively. The western blot analysis revealed no significant decrease of PTEN expression in the most invasive clones (named HN6.1, HN30.1 and HN31.1). Only HaCat.1 had a significant decrease (p<0,05). However, there was no significant increase of Akt in the invasiveness clones and oppositely the expression of Akt was strongly reduced (p<0,05) in the HaCat.1. Finally, the zimography showed a discrete increase of inactive MMP-2 and/or a significant increase of active MMP-9 in all the most invasive cell lines. In conclusion, no correlation was seen between PTEN and pAkt in the process of invasion in vitro. There is not only a linear PTEN-PI3K-Akt pathway in OSCC. The HaCat.1 had a different behavior in relation to OSCC cell lines and probably allowed cellular differentiation. In addition, a significant increase of active MMP-9 was seen in 2 of 3 lines of cells derived from OSCC
17

Pharmacologic profiling of novel compounds via fluorometric analyses of monoamine transporter responses

Hojati, Ashkhan 01 January 2019 (has links)
In humans and other organisms, monoaminergic systems are crucial in neuronal function and behavior. The monoamine transporters (MATs), which can be found on the presynaptic plasma membrane of neurons in the central nervous system (CNS), are crucial in the regulation of neurotransmitter concentration in the synaptic cleft. As the duration and concentration of neurotransmitters in the cleft affect further downstream signaling responses, these proteins are important targets for both understanding neuronal physiology and compounds of interest. Multiple theories exist proponing the contribution of MATs to a variety of mental and neurological disorders, including depression. This theory establishes that depression is caused by imbalances in monoamine neurotransmitters. Compounds such as Fluoxetine (FLX) are classified as selective serotonin reuptake inhibitors (SSRIs), these drugs selectively block the reuptake of neurotransmitters at the serotonin transporter (SERT). Since differences in MAT selectivity of inhibitory compounds are influential to selecting efficacious antidepressant treatments, we utilized a unique fluorescent analysis technique to explore three therapeutic compounds of interest (in-vitro) which contain structural similarity to FLX. Our results confirm the selectivity of FLX at SERT, and classify the novel compounds studied into different potential categories of reuptake inhibitors. We hope these compounds will be studied further to elucidate their potentially therapeutic roles and mitigation of undesired side effects seen in other medications.
18

Chemotherapy in Childhood Acute Lymphoblastic Leukemia : In vitro cellular drug resistance and pharmacokinetics

Frost, Britt-Marie January 2002 (has links)
<p>The aims of the studies described in this thesis were to investigate the pharmacokinetics of and cellular resistance to chemotherapy as causes of treatment failure in childhood acute lymphoblastic leukemia (ALL).</p><p>Leukemic cells from 370 children with newly diagnosed ALL were tested by the Fluorometric Microculture Cytotoxicity Assay to measure their resistance to each of ten standard cytotoxic drugs. In the high-risk group, increased in vitro resistance to each of the drugs dexamethasone, etoposide and doxorubicin was associated with a worse clinical outcome. Combining the results for these drugs yielded a drug resistance score, showing a relative risk of relapse in the most resistant group that was 9.8 times higher than in the most sensitive group. In the standard-risk and intermediate-risk groups, final evaluation must await longer follow-up.</p><p>The new cytotoxic agent CHS 828 was equally active in vitro in samples from children with acute myeloblastic leukemia (AML) and ALL, with 50% cell kill at concentrations achievable in vivo. In AML samples CHS 828 also displayed high frequencies of synergistic interactions with four standard drugs. The well-known differences in clinical outcome between Down´s syndrome (DS) and non-DS children with acute leukemia may partly be explained by our finding of differences in drug resistance at the cellular level.</p><p>Pharmacokinetic studies were performed at the start of induction treatment of ALL. Doxorubicin was assayed by reversed-phase liquid chromatography with fluorometric detection, and vincristine by high performance liquid chromatography with electrochemical detection. Plasma doxorubicin concentrations were measured in 107 children after 23 h of a 24-h infusion. The median steady-state concentration in children 4-6 years old, a group known to have a favorable outcome of treatment, was about 50% higher than in those 1-2 and >6 years old Vincristine pharmacokinetics was evaluated in 98 children. There was no correlation between age and total body clearance or any other pharmacokinetic parameters.</p><p>In vitro testing of cellular drug resistance might be useful in predicting the outcome in high-risk ALL. The further exploration of CHS 828 in childhood leukemia seems warranted. There is no pharmacokinetic rationale for the common practice of administering relatively lower doses of vincristine to adolescents than to younger children.</p>
19

Application of In Vitro Chemosensitivity Testing for Evaluation of New Cytotoxic Drugs in Chronic Lymphocytic Leukaemia

Åleskog, Anna January 2002 (has links)
<p>Despite major advances in the understanding of the biology of chronic lymphocytic leukaemia (CLL), progress in improving its treatment has been limited and it still remains an incurable disorder. In the present research, we have performed <i>in vitro</i> drug sensitivity testing of primary CLL cells for preclinical evaluation of cytotoxic drugs, using the fluorometric microculture cytotoxicity assay (FMCA).</p><p>The tumour type-specific activities of 14 standard drugs, evaluated <i>in vitro</i> on tumour cells from patients with CLL and acute leukaemias, were in good agreement with their known clinical activities. A correlation between drug treatment and development of cellular drug resistance was demonstrated in CLL, but not in the acute leukaemias. Moreover, the nucleoside analogues fludarabine, cladribine, cytarabine and gemcitabine, as well as the anthracycline idarubicin, were highly active in CLL cells.</p><p>A new cytotoxic drug candidate, CHS 828, was evaluated in primary cell cultures from a broad spectrum of tumours. CHS 828 was highly active against haematological malignancies <i>in vitro</i>, especially CLL, but also against some solid tumours. The drug appeared to be non cross-resistant with standard drugs.</p><p>In addition, the relationship between drug sensitivity <i>in vitro</i> and a recently described prognostic factor in CLL, the mutational status of the immunoglobulin variable heavy chain (IgV<sub>H</sub>) gene, was evaluated. Interestingly, cells with unmutated IgV<sub>H</sub> genes were more chemosensitive than the mutated cells. </p><p>In summary, our results indicate that <i>in vitro</i> studies on tumour cellsfrom leukaemia patients may yield considerable information regarding the activity, mechanisms of action and cross-resistance of cytotoxic drugs, as well as concerning the relationship between drug sensitivity and prognostic factors, which can be useful in the preclinical evaluation of new cytotoxic drugs. Furthermore, the results suggest that the pyrimidine analogues cytarabine and gemcitabine, as well as the anthracycline idarubicin, may have a role in the treatment of CLL. The new cyanoguanidine CHS 828 is highly active in CLL cells and appears to be non cross-resistant with standard drugs. The poorer prognosis in patients with CLL cells with unmutated IgV<sub>H</sub> genes can not be explained by increased chemoresistance.</p>
20

Acute Lymphoblastic Leukaemia in Adult Patients : Studies of Prognostic Factors, Treatment Results and in vitro Cellular Drug Resistance

Hallböök, Helene January 2005 (has links)
<p>Treatment results and clinical characteristics in adult acute lymphoblastic leukaemia (ALL) were evaluated regarding three issues: a new treatment with cytarabine up-front, stem cell transplantation and a comparison between adult and paediatric treatment protocols. All studies were conducted on a national basis. Furthermore, activity of imatinib was investigated by in vitro cytotoxicity assay. </p><p>The national protocol was evaluated in 153 adult ALL patients. A high complete remission rate, 86%, was achieved with 29% overall survival at 3-years. Favourable outcome was identified in patients < 40 years with precursor B phenotype and continuous complete remission was higher for precursor B compared to T-ALL. </p><p>Stem cell transplantation was evaluated in 187 patients. No differences in outcome between allogeneic and autologous transplantation were found, with the exception of Philadelphia-positive ALL, in which allogeneic transplantation was preferable. Limited chronic graft-versus-host disease (compared to none) resulted in superior disease free survival. </p><p>The paediatric NOPHO-92 and the Adult protocols were evaluated for 243 ALL-patients. Superior remission rate and survival were achieved for 10-18 year-olds treated according to the Paediatric protocol compared to both 15-25 and 25-40 year-olds treated according to the Adult protocol. Treatment protocol was a significant prognostic factor for patients aged 15-20 years. </p><p>Fluorometric Microculture Cytotoxicity Assey was used to analyze 15 tumour cell samples from ALL patients. High concordance was determined between in vitro sensitivity to imatinib and presence of BCR-ABL. Daunorubicin, prednisolone and cytarabine had the greatest benefit from a combination with imatinib. </p><p>The national adult treatment protocol’s results were consistent with international trials regarding precursor B ALL but may be under performing for T-ALL. Adolescents may benefit from treatment according to the Paediatric protocol. No difference in outcome between allogeneic and autologous stem cell transplantation was determined except for Philadelphia-positive patients, despite the indication of a graft-versus-leukaemia effect.</p>

Page generated in 0.1313 seconds