No description available.

RenewFuncBarr

No description available.

The aims of this study are to synthesize and produce a single-chain antibody (scFv) of the anti-cytokeratin 8 monoclonal IgG antibody TS1 and to functionally map amino acid residues important for the interaction with its antigen and the anti-idiotypic antibody TS1. The TS1 antibody has been shown to be effective in binding cytokeratin 8 (CK8) expressed in tumors in vivo and is proposed to be useful in immunotargeting and/or immunotherapy. The anti-idiotypic antibody TS1 can be used to regulate the tumor:non-tumor ratio. Mutagenesis of certain amino acid residues can be used to alter the affinity to improve the tumor:non-tumor ratio further. In the present study, the TS1 IgG was chemically modified to specify groups of residues important for interaction with both CK8 and TS1. If important residues were found in the CDRs, they were mutated in the TS1 scFv construct and the effect was studied using ELISA. The main conclusions drawn from this study are that the important amino acid residues in TS1 for the interaction with both CK8 and TS1 are mainly tyrosines, charged residues and a tryptophan. A central interacting interface was identified with the somewhat unusual participation of residues in the CDR 2 of the light chain. Mutations which resulted in increased affinity to both CK8 and TS1 were also identified.

QC 20110117

<p>Examen i vårdadministration, YH-utbildning: 20 Yh-poäng</p>

In this thesis, quantum chemical methods have been used to shed light on the reaction mechanisms of several dinuclear zinc enzymes. The enzymes studied are involved in the hydrolysis of phosphates, amides, and carboxylic esters, namely RNase Z, Dihydroorotase (DHO), and N-acyl homoserine lactone hydrolase (AHL lactonase). The density functional method B3LYP, together with quite large active site models, was used to investigate these enzymatic reactions. Several plausible proposed mechanisms, involving protonation states of important active site residues (DHO), substrate orientations (AHL lactonase), have been considered. The calculated energetics can be used to assess the feasibility of the suggested reaction mechanisms. Based on the calculations and also on other related dinuclear zinc enzymes studied previously, some general mechanistic features have been uncovered. For all three enzymes, the nucleophilicity of the bridging hydroxide is shown to be sufficient to perform the nucleophilic attack on the substrates. During the attack, the negative charge is transferred from the bridging hydroxide to the substrate oxygen (P=O or C=O). For phosphate hydrolysis, an in line attack have been suggested for RNase Z. In addition, the two zinc ions in RNase Z are directly involved in stabilizing the negative charge in the penta-coordinated transition states. For carbonyl substrates, only one zinc ion participates in the oxygen anion stabilization in the transition states and the tetrahedral intermediates. Furthermore, the enzymes always use the zinc ion with less negatively-charged ligands to play such role. All the substrates investigated have poor leaving groups. Therefore, either the zinc ions or some active site residues help the cleavage of the scissile bond. For RNase Z, a Glu-His diad was suggested to protonate the leaving group. For DHO, an Asp residue was shown to transfer a proton from the bridging hydroxide to the leaving group nitrogen. For AHL lactonase, a zinc ion was also observed to stabilize the leaving oxygen anion.

O cancro de pulmão é a neoplasia com maior incidência e maior taxa de mortalidade em todo o mundo, sendo o diagnóstico em estadios avançados o principal determinante de mau prognóstico. Novas terapias, como a imunoterapia, melhoram a sobrevivência global, mas apenas 30-40% dos doentes respondem a esses tratamentos, atribuindo-se essa baixa resposta a vias alternativas de imunossupressão, adotadas pelos tumores de pulmão, incluindo macrófagos associados a tumores (TAM). CSF-1 está implicada no recrutamento e diferenciação de TAM, bem como na angiogénese tumoral, em especial via um subgrupo de macrófagos que expressa o recetor Tie-2, que respondem à angiopoietina-2 (Ang-2). Neste trabalho, avaliou-se o papel dos níveis séricos de CSF-1 no prognóstico do cancro do pulmão de pulmão de células não-pequenas (CPCNP) e se estes podem servir de biomarcadores de deteção de CPCNP, juntamente com Ang-2. Realizamos um estudo prospetivo que incluiu 145 doentes com CPCNP e 30 indivíduos saudáveis. Os níveis séricos de CSF-1 e Ang-2 foram medidos por ELISA antes da realização de qualquer tratamento. Existe uma forte correlação entre os níveis séricos de CSF-1 e Ang-2 (p<0.000001). Indivíduos com níveis séricos elevados de CSF-1 mostram um risco dezassete vezes superior para apresentarem CPCNP e fenótipos com elevação simultânea de níveis séricos de CSF-1 e Ang-2 estão associados a pior prognóstico do CPCNP. Dado que a expressão elevada combinada de CSF-1 e Ang-2 parece estar presente em doentes com pior prognóstico, seria interessante conhecer a base desta interação, explorando a relação entre as duas as moléculas. Para além disto, pensamos que o CSF-1 poderá ser incluído como biomarcador em protocolos de rastreio de CPCNP, visando a melhoria do valor preditivo positivo das formas de rastreio atualmente delineadas, aumentando a relação custo-efetividade e melhorando a sobrevivência global dos doentes ao permitir diagnósticos mais precoces. / Lung cancer is the most incident and lethal form of cancer, with late diagnosis as a major determinant of its bad prognosis. Immunotherapies targeting immune checkpoints improve survival, but positive results encompass only 30-40% of the patients, possibly due to alternative pathways to immunosuppression, including tumor associated macrophages (TAM). CSF-1 is implicated in TAM differentiation and recruitment to tumors and in tumor angiogenesis, through a special setting of Tie-2-expressing macrophages, which respond to Angiopoietin-2 (Ang-2). We evaluated the role of serum levels of CSF-1 in NSCLC prognosis and whether these could serve as biomarkers for NSCLC detection, along with Ang-2.We prospectively studied an unselected cohort of 145 NSCLC patients and a group of 30 control individuals. Serum levels of Ang -2 and CSF-1 were measured by ELISA prior to treatment. Serum levels of CSF-1 and Ang-2 are positively correlated (p<0.000001). Individuals with high serum levels of CSF-1 present a seventeen-fold risk for NSCLC development and patients with combined High Ang-2/CSF-1 serum levels present a 5-fold increased risk of developing NSCLC. High Ang-2/CSF-1 phenotype is also associated with worst prognosis in NSCLC. Combined expression of CSF-1 and Ang-2 seems to contribute to worst prognosis in NSCLC and it is worthy to understand the basis of this unexplored partnership. Moreover, we think CSF-1 could be included as a biomarker in NSCLC screening protocols that can improve the positive predictive value of the current screening modalities, increase overall cost effectiveness, and potentially improve lung cancer survival.

No description available.

No description available.