• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 119
  • 58
  • 31
  • 10
  • 9
  • 4
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 302
  • 126
  • 80
  • 74
  • 61
  • 55
  • 42
  • 27
  • 25
  • 24
  • 24
  • 23
  • 22
  • 21
  • 20
  • 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.
61

A novel T cell activating factor

Williams, Laura Dawn January 1987 (has links)
The maturation of cytotoxic T lymphocyte (CTL) effectors from CTL precursors (CTLp) requires specific signals mediated through cellular interactions and soluble factors. The most studied factor is T cell growth factor (TCGF) which is also termed interleukin-2 (IL-2). This lymphokine is produced by T helper cells (TH) and induces activated CTLp to proliferate and differentiate. However, in the absence of mitogen or antigen stimulation, IL-2 alone cannot induce CTL (except in the case of very high cell density). A factor is described that is found in the supernatant of 4-β-phorbol-12-myristate-13-acetate (PMA)-induced EL4 cells that can polyclonally activate CTL in the presence of IL-2. This factor elutes at 27 kilodaltons (KDa) on a G-100 column, and its target cell includes T cells of the Thyl⁺ Lyt2⁺ L3T4⁻ phenotype. The factor increases the frequency of IL-2 receptor expressing cells within a population, thereby increasing the response to IL-2. It is suggested that this factor acts through an alternative pathway of CTL activation which is independent of specific stimulation by antigen. / Medicine, Faculty of / Medical Genetics, Department of / Graduate
62

Cytotoxic molecules of Mycoplasma Pneumoniae and their relationship with biofilm growth

Nzenwata, Davidson Ugochukwu 19 November 2021 (has links)
No description available.
63

Syntéza a studium reaktivity a biologické aktivity C5 substituovaných analog uracilu / Synthesis, reactivity and biological activity of C5 substituted uracil analogues

Brulíková, Lucie January 2011 (has links)
Bibliographical identification: Author's first name and surname: RNDr. Lucie Brulíková (nee Spáčilová) Title: Synthesis, reactivity and biological activity of C-5 substituted uracil analogues Type of thesis: Ph.D. thesis Department: Department of Organic Chemistry, Faculty of Science, Palacký University Olomouc Advisor: prof. RNDr. Antonín Holý, Dr.Sc., Dr.hc. mult. Advisor-consultant: doc. RNDr. Jan Hlaváč, Ph.D. The year of presentation: 2011 Abstract: The presented thesis is focused on the synthesis of various C-5 modified uracil analogues, the study of their reactivity and biological activity, especially cytotoxic activity. In the first part, the brief survey of described results for selected 5-alkoxymethyluracil analogues is performed. The second part of the presented thesis deals with the synthesis of novel uracil analogues modified at the C-5 position, the development and optimizing of procedure leading to the desired compounds, the study of biological activity and the evaluation of structure- activity relationship (SAR). This part presents the synthesis of a series of 5-[alkoxy(4- nitrophenyl)methyl)]uracil and 5-alkoxymethyluracil analogues and extended SAR studies depending on a substitution of metylene bridge directly attached at the C-5 position as well as alkoxy chain length. The last part of...
64

CD8+ T Cell Mediated Immunity is Disrupted by Ex Vivo and In Vivo Opioid Use

Mazahery, Claire 01 June 2020 (has links)
No description available.
65

T Cell Intrinsic and Extrinsic Role of XIAP, During CD8 T Cell Response Against Intracellular Pathogens

Thakker, Parva 19 July 2021 (has links)
The magnitude and effectiveness of CD8 response against intracellular pathogens is directed by survival and apoptotic signals that govern the fate of T cells. XIAP is a bona fide endogenous inhibitor of apoptotic signals. In this thesis, I have investigated the role of XIAP at various stages of CD8 T cell response. I used both in vivo and in vitro models to show that XIAP acts in a CD8 T cell extrinsic and intrinsic manner to regulate the expansion and contraction phases of the CD8 T cell response, respectively. During the expansion phase, XIAP prevents the cell death of APCs to promote APC-T cell interaction and cytokine release, which facilitates the proliferation and survival of activated T cells. During the contraction phase, XIAP functions in a cell-intrinsic fashion to inhibit the proapoptotic signals in the activated CD8 T cells to prolong the immune response. Finally, I also demonstrate that the expression of XIAP in T cells is critical for their differentiation in to memory subsets. Overall, I present that XIAP plays a critical role in generating an effective CD8 T cell immune response.
66

High Glucose Distinctively Regulates Ca<sup>2+</sup> Influx in Cytotoxic T Lymphocytes Upon Target Recognition and Thapsigargin Stimulation

Zou, Huajiao, Yang, Wenjuan, Schwär, Gertrud, Zhao, Renping, Alansary, Dalia, Yin, Deling, Schwarz, Eva C., Niemeyer, Barbara A., Qu, Bin 01 December 2020 (has links)
No description available.
67

Structurally Related Flavonoids CT1 and CT3 Have Cytotoxic Activity On Triple Negative MDA-MB-231 Breast Cancer Cells By Targeting The MEK-ERK Pathway

Belcher, Dewey A, III, Hackworth, Keagan Davis, Hagood, Kendra Lyndsey, Aramburo, Jacqueline, Umeh, chukuwunyere, Michaud, Kristen, Morgan, Cunningham, Garrett, Mudd, Torrenegra, Ruben, Gina, Mendez-Callejas, Palau, Victoria 07 April 2022 (has links)
Breast cancer is the most commonly diagnosed cancer in women with an estimated 287,850 cases in 2022. Approximately 684,000 deaths each year are associated with breast cancer across the world. Risk factors of breast cancer include increased estrogen exposure, family history of breast cancer, and environmental factors. Treatment of breast cancer is highly dependent on the presence of HER2, estrogen, and progesterone receptors. Breast cancers that present with increased receptors for estrogen, progesterone, and HER2 are typically the least aggressive and the easiest to treat. The percentage of cases in the United States associated with hormone receptor positive and HER-2 negative or positive are approximately 82%. Absence of receptors for estrogen, progesterone, and HER2 is known as triple negative breast cancer. In the United States, only about 10% of cases are associated with this form. However, it is considered the most aggressive and difficult to treat. Two emerging flavonoids known as CT1 and CT3 have shown cytotoxic activity against cell lines that represent some of the most common breast cancers: MCF7, MDA-MB-231, and SKBr3. CT1 and CT3 were extracted from the leaves of Chromolaena tacotana using a Soxhlet extractor and the compounds then underwent isolation and purification. The cells were then treated with CT1 or CT3 at concentrations of 5, 10, 20, 40 and 80 µM. MTT assays were then used to determine cell viability. MDA-MB-231, the most aggressive type of breast cancer cells, responded to both CT1 and CT3. The most profound cytotoxic effects of CT1 were seen with MCF7 and MDA-MB-231, while CT3 exhibited a greater toxicity against SKBr3 cells. Preliminary results indicate that CT1 and CT3 target the MEK-ERK signaling pathway. Further studies need to be completed to determine mechanistically how these compounds lead to receptor-independent toxicity.
68

ASSESSMENT OF BIODEGRADATION AND TOXICOLOGICAL EFFECTS OF MICROCYSTINS

Krishnan, Anjali 27 June 2019 (has links)
No description available.
69

Development of a PNA-drug conjugate for pretargeted delivery of cytotoxic drugs

Haraldsson, Astrid January 2023 (has links)
One of the major challenges in cancer treatment is delivering high enough doses of active substance specifically to cancer cells without accumulation in healthy organs. Pretargeting has emerged as a potential solution, where the delivery of a cancer recognizing (primary) agent and a cancer killing (secondary) agent are separated. Pretargeted cancer therapy utilizing PNA probes has proved to be a promising approach to selectively deliver toxic payloads to cancer cells while minimizing accumulation in healthy organs. The aim of this project was to develop a new set of secondary PNA probes specifically designed for PNA pretargeted delivery of cytotoxic drugs. A HER2-specific Affibody molecule, ZHER2:2891-SR-H6, was recombinantly produced in E. coli before being conjugated to a primary PNA hybridization probe, HP9, through sortase A-mediated ligation, to produce the primary agent, ZHER2:2891-SR-HP9. Circular dichroism (CD) spectroscopy confirmed the stability of the constructs with high melting temperatures of 71.2 and 73.7 °C. Surface plasmon resonance (SPR) analysis demonstrated high binding affinity to HER2, slightly affected by PNA conjugation. Three new secondary PNA hybridization probes were designed, differing mainly in prevalence and position of a hydrophilic PEG molecule. The probes were produced by solid phase peptide synthesis and conjugated to the cytotoxic drug DM1 through maleimide-cysteine coupling. Analytical RP-HPLC evaluation revealed a slightly higher apparent hydrophobicity for the probe with PEG in the main chain. All three secondary probes displayed high affinity to the primary probe with KD values between 498–505 pM. In vitro cytotoxicity studies on HER2-overexpressing cells demonstrated comparable potent cytotoxic activity for pre-incubated primary and secondary probes with IC50 values of 10–14 nM. These results indicate the successful development of three PNA-drug conjugates for pretargeted delivery of cytotoxic drugs.
70

Activation of CD8+ Cytotoxic T Lymphocytes against Tumor Cells using a TLRL-MUC1-Tn Cancer Vaccine

Lee, Kyunghee January 2013 (has links)
No description available.

Page generated in 0.0294 seconds