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The investigation of an abdominal mass in a child is a common problem in the radiology department of the Red Cross Children's Hospital. The majority of these masses involve the urinary tract. The commonest neoplasm is a Wilms' tumour of the kidney. Against a pathological and clinical background, the investigation of Wilms' tumour by diagnostic imaging is presented. The imaging modalities currently utilised are the intravenous urogram (IVU), ultrasound (US), computed tomography (CT) and magnetic resonance (MR). Using the material available in the last decade, the principles, techniques and imaging characteristics of these modalities are investigated and compared. These results are reflected against those reported in the medical literature. This literature is not yet extensive as the current technology has only been available for the last six to seven years. The IVU has in the past been the main imaging modality and we still use it extensively. Its strengths and weaknesses are discussed. In the last five years US has taken its place as the primary method of diagnostic imaging. We have found that with our increasing experience that this is justified. The use of US and IVU in a practiced hand is a powerful diagnostic combination. CT as a primary investigation is not readily available at our institution. We have used it for comparative purposes in about 20% of our recent cases. CT has not added greatly to our initial diagnostic impression. However, it has been most useful for follow up of metastasis and for assessing the normality of the lungs before ceasing chemotherapy. Our experience with MRI is limited and confined to unusual presentations in the last year. Other modalities such as arteriography and nuclear medicine have special indications which are to be discussed. The remaining tumours of the upper urinary tracts are all rare, but are reported and the literature researched. In the lower urinary tract the main pelvic lesion is a rhabdomyosarcoma. The comparative advantages of the IVU, US, CT and MRI are also noted. In the pelvis, US has also become the primary imaging modality, and is replacing contrast medium cystography. However, examples of the latter are included as it still has a place, particularly in the less sophisticated institutes. CT and MRI, when available, have imaging advantages in the pelvis and are becoming the methods of choice for follow up. The main objective of this document has been to investigate the available imaging techniques, but, against this overall theme, the clinical care of the child is most important. With this in mind the treatment protocols that are used at our hospital are noted in the appendices to the thesis.

Thesis (MNutr)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Introduction and purpose The aim of the study was to determine the renal handling of a once-off bolus dietary protein load in patients treated for nephroblastoma. Patients who have been managed for nephroblastoma always have suboptimal amounts of kidney tissue as a result of their medical management which includes nephrectomies, chemotherapy and or radiotherapy. Little data are available indicating the extent of renal impairment expected in such patients as a result of their disease and management. The study was to determine whether the use of regular screening tests such as serum urea, creatinine and urine microalbumin, in conjunction with a dietary protein load could help detect early progressive deterioration of kidney function in nephroblastoma patients. Methodology The study was a quantitative non-randomised intervention study in which patients served as their own control before and after a protein load. Thirty-four participants were included in the study. Each participant was provided with a supplemental protein drink providing 2 g/kg body weight of protein. Serum creatinine, urea and urine microalbumin were assessed at baseline and four hours after the intervention. These pre- and post intervention biochemical values were then analysed together with descriptive data relating to the participants, such as age, stage of nephroblastoma, aspects of medical management and the period of time since they had been treated for nephroblastoma, and statistical relationships were assessed. Data were collected from May 2010 to November 2010. Results Descriptive statistics indicated that the mean [± Standard deviation (SD)] age of the population was 92 (± 55) months, the mean age at diagnosis was 41 (± 27) months and the mean age from the diagnosis to the time of the study was 51 (± 53) months. There was a statistically significant increase (p = 0.00) in serum urea post intervention; however, no significant difference was noted between pre- and post intervention serum creatinine and urine microalbumin values. The stages of nephroblastoma failed to show a statistical correlation with the response to the dietary protein bolus load in terms of the difference in pre- and post intervention biochemical data. No statistical correlation was found between post-pubescence and response to the protein load. Similiarly, no statistical correlation could be demonstrated for a longer period between the diagnosis and the time of this study, on the one hand, and the prevalence of high values in the biochemical data, on the other. Conclusion The study was unable to demonstrate statistically that participants managed for nephroblastoma had poor renal handling of a once-off dietary protein load in terms of the objectives specified. The study had limitations including a small population with even smaller subgroups of participants, therefore results of the study need to be interpreted in context to the size of the population. / AFRIKAANSE OPSOMMING: Doel Die doel van die studie was om die renale hantering van ’n eenmalige bolus dieetproteïenlading by pasiënte wat vir nefroblastoom behandel word, te bepaal. Pasiënte wat vir nefroblastoom behandel word, het altyd ‘n subopitmale hoeveelheid nierweefsel as gevolg van hulle mediese behandeling wat nefrektomies, chemoterapie en / of radioterapie insluit. Min data is beskikbaar omtrent die omvang van die nierbelemmering wat in sulke pasiënte verwag word as gevolg van hulle siekte en behandeling. Die studie is uitgevoer om te bepaal of die gebruik van gereelde siftingstoetse soos serum-ureum, kreatinien en mikroalbuminurie, in samewerking met ‘n dieetproteïenlading, kan help om vroeë progressiewe agteruitgang van nierfunksie in nefroblastoom pasiënte, op te spoor. Metodologie Die studie was ‘n kwantitatiewe nie-ewekansige intervensie studie waar pasiënte as hul eie kontrole gedien het voor en na ‘n proteïenlading. Altesaam 34 deelnemers is by die studie betrek. Elke deelnemer het ’n proteïenaanvullingsdrankie ontvang wat 2 gram proteïen per kilogram liggaamsgewig voorsien het. Serumkreatinien, serum-ureum en mikro-albuminurie is op die basislyn sowel as vier uur na die intervensie gemeet. Hierdie biochemiese waardes voor en na die intervensie is daarna saam met beskrywende data van die deelnemers – soos ouderdom, stadium van nefroblastoom, aspekte van mediese behandeling en tydsverloop sedert behandeling vir nefroblastoom – ontleed. Statistiese verwantskappe is vervolgens beoordeel. Data is vanaf Mei 2010 tot November 2010 ingesamel. Resultate Beskrywende statistieke het op ’n gemiddelde [± Standaard afwyking (SA)] populasie-ouderdom van 92 (± 55) maande, ’n gemiddelde diagnose-ouderdom van 41(± 27) maande en ’n gemiddelde ouderdom van 51(± 53) maande vanaf diagnose tot en met die studie gedui. Ná die intervensie is ’n statisties beduidende toename (p = 0.00) in serum-ureum opgemerk, hoewel daar geen beduidende verskil in serumkreatinien en mikro-albuminurie waardes, voor en na behandeling, was nie. Biochemiese data voor en na die intervensie het geen statistiese verwantskap tussen die stadium van nefroblastoom en die reaksie op die dieetproteïenlading getoon nie. Boonop is geen statistiese verwantskap opgemerk tussen post-pubesensie en die reaksie op die proteïenlading, of tussen ’n langer tydsverloop tussen die diagnose en die studie en die voorkoms van hoë waardes in die biochemiese data nie. Gevolgtrekking Wat die studie-doelwitte betref, kon die navorsing nie statisties bewys dat deelnemers wat vir nefroblastoom behandel word, swak renale hantering van ’n eenmalige dieetproteïenlading toon nie. Die beperkinge van die studie sluit ‘n klein populasie met selfs kleiner subgroepe in; die resultate van die studie moet derhalwe in die konteks van die grootte van die populasie, geÏnterpreteer word.

The aims of this study were: (i) to determine the association between p53, bcl-2, pRb, p21, cyclin A and p-glycoprotein immunoexpression and prognosis, and (ii) to determine the frequency of loss of heterozygosity and microsatellite instability at 11 p, 16q and mismatch repair gene loci and their association with prognosis, in nephroblastomas in South African children. There were 138 cases (111 of whom received preoperative chemotherapy) in the immunohistochemical study and, 70 cases (48 with preoperative chemotherapy) in the microsatellite study. The following monoclonal antibodies were used after heat induced epitope retrieval; p53, bcl-2, pRb, p21, cyclin A and p-glycoprotein. Six polymorphic microsatellite markers were selected from the 11p region, 5 from the 16q region and 6 from the loci of known mismatch repair genes. Automated fluorescent DNA technology was used in the analysis. The results of the immunohistochemical and microsatellite studies were correlated with patient age, gender, preoperative chemotherapy, SlOP histological classification, SlOP histological risk group, clinicopathological stage, patient outcome and survival using X2 , Fisher's exact test, Cox regression model and Kaplan-Meier estimates. The majority of patients presented with advanced disease. Anaplastic tumours and high-risk histology were associated with high disease stage. Mortality was directly related to increasing stage and histological risk group. Multivariate analysis showed that clinicopathological stage was the only factor significantly associated with survival (p<0.001) (hr=5.6, 95%CI: 2.1-14.9). High expression of p53 was more frequent in anaplastic tumours suggesting that p53 mutations are common events in this tumour type (p<0.001). Despite the strong association with tumour histology, there was no association with stage. Although p53 expression was found to be a predictor of survival in the univariate analysis this was not retained in the multivariate analysis. Tumours treated with preoperative chemotherapy showed higher bcl-2 immunoreactivity (p=0.027 but lower levels of pRb (p=0.040) and cyclin A expression (p<0.001). All anaplastic tumours showed high expression of pRb compared to the other histological types (p=0.003). Expression of xxii pRb was significantly associated with survival in the univariate analysis but not in the multivariate analysis. High cyclin A expression was associated with high risk histology (p<0.001). Cyclin A expression was found to be a significant predictor of survival in both the univariate (hr=1.7; 95%CI 1.2-2.4; p=0.002) and multivariate analyses (hr=1.7; 95%CI1.1-2.7; p=0.032). Although tumours with high risk histology were more likely to express high levels of p-glycoprotein, this did not reach significance. LOH at 11 p was seen in 64.7% of 68 informative cases. LOH at 11 p13 was more frequent than LOH at 11p15. LOH for both 11p13 and 11p15 was found in 39.7% of all tumours. MSI at 11 p was seen in 22.1 % of informative cases. The majority showed MSI for one marker only. LOH 16q was seen in 66.7% of 66 informative cases. MSI at 16q was seen in 16.7% of cases. LOH for 016S496 and 016S520 appear to be related to tumour histology and risk group. The most frequent locus for LOH was 16q21-22, which is known to harbour important genes, such as, E2F4 and E-cadherin. LOH for MMR markers was seen in 43.5% of 69 informative cases. MSI was seen in 11.6% of tumours. In the multivariate analysis there was no significant correlation between LOH at any of the loci studied and survival. There were no tumours with high frequency MSI. Low frequency MSI was of no clinicopathological significance. The following conclusions are made: (i) p53 mutations determined by high p53 expression is a frequent finding in anaplastic tumours, (ii) Bcl-2 may play a role in the chemoresistance of nephroblastomas, (iii) Rb gene alterations are not important in the development of nephroblastoma and anaplasia, (iv) Cyclin A expression is an independent predictor of survival, (v) p-glycoprotein may be responsible for the chemoresistance in a proportion of nephroblastomas, (vi) MSI is a rare occurrence in nephroblastoma and does not play a role in the development of nephroblastoma, (vii) LOH at 11 p and 16q are frequent findings in nephroblastomas, (viii) LOH for the specific 16q markers (016S496 and 016S520) may have an important prognostic role in nephroblastoma. / Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2008.

<p>Angiogenesis is necessary for the growth and spread of solid tumors. In these studies angiogenesis was measured in childhood malignancies in general and in Wilms’ tumor in particular, and cutting needle biopsy (CNB) specimens were evaluated for diagnosis in childhood renal tumors. </p><p>In 33 patients with Wilms’ tumor, tumor capillaries were quantified, expression of angiogenic growth factors in tumor tissue investigated, and concentrations of angiogenic growth factors in serum measured. Reference values for angiogenic growth factors were obtained in 80 healthy adults (fibroblast growth factor 2 [FGF-2], vascular endothelial growth factor A [VEGF-A]) and 94 healthy children (angiogenin [ANG], epidermal growth factor [EGF], FGF-2, hepatocyte growth factor [HGF], tumor necrosis factor alpha [TNFA] and VEGF-A) aged 0.5-18 years. These reference values were compared with values in sera taken at diagnosis in 268 children with tumors and leukemias. CNB specimens were evaluated in 25 children with renal tumors.</p><p>A large number of capillaries was an independent prognostic factor for a poor outcome in Wilms’ tumor. Angiogenic growth factors were expressed in Wilms’ tumor tissue, and elevated concentrations of HGF and VEGF-A were found in both benign and malignant tumors. HGF was increased in leukemia, and TNFA was increased in leukemia, lymphoma and neuroblastoma. CNB, which proved to be a safe procedure, had a sensitivity of 76%. </p><p>These studies have demonstrated that quantification of capillaries is a prognostic factor in Wilms’ tumor and that HGF, TNFA and VEGF-A are frequently elevated in sera from children with cancer. Quantification of capillaries in tumor tissue and of circulating angiogenic growth factors would therefore seem to be of clinical relevance in managing children with cancer.</p>

Angiogenesis is necessary for the growth and spread of solid tumors. In these studies angiogenesis was measured in childhood malignancies in general and in Wilms’ tumor in particular, and cutting needle biopsy (CNB) specimens were evaluated for diagnosis in childhood renal tumors. In 33 patients with Wilms’ tumor, tumor capillaries were quantified, expression of angiogenic growth factors in tumor tissue investigated, and concentrations of angiogenic growth factors in serum measured. Reference values for angiogenic growth factors were obtained in 80 healthy adults (fibroblast growth factor 2 [FGF-2], vascular endothelial growth factor A [VEGF-A]) and 94 healthy children (angiogenin [ANG], epidermal growth factor [EGF], FGF-2, hepatocyte growth factor [HGF], tumor necrosis factor alpha [TNFA] and VEGF-A) aged 0.5-18 years. These reference values were compared with values in sera taken at diagnosis in 268 children with tumors and leukemias. CNB specimens were evaluated in 25 children with renal tumors. A large number of capillaries was an independent prognostic factor for a poor outcome in Wilms’ tumor. Angiogenic growth factors were expressed in Wilms’ tumor tissue, and elevated concentrations of HGF and VEGF-A were found in both benign and malignant tumors. HGF was increased in leukemia, and TNFA was increased in leukemia, lymphoma and neuroblastoma. CNB, which proved to be a safe procedure, had a sensitivity of 76%. These studies have demonstrated that quantification of capillaries is a prognostic factor in Wilms’ tumor and that HGF, TNFA and VEGF-A are frequently elevated in sera from children with cancer. Quantification of capillaries in tumor tissue and of circulating angiogenic growth factors would therefore seem to be of clinical relevance in managing children with cancer.

Nephroblastoma is the most prevalent pediatric kidney tumor, which occurs primarily in younger children with the average age at diagnosis of 42,5 months for girls and 36,5 months for boys. Even though its treatment is currently very succesful and the overall survival rate reaches over 90 %, there are still more things to be discovered and improved. An important role for the right choice of treatment plays not only the histology of tumor, but also the chromosomal changes present at tumor. Some of them (for example 1q gain, simultaneous deletion of 1p and 16q, TP53 deletion) were confirmed as negative prognostic markers because they are associated with an increased risk of relapse or with anaplastic type of nephroblastoma that is included in a high risk group. These changes are therefore used together with the tumor histology for stratification of nephroblastomas. Some of these changes were found in a heterogeneous state (only in a part of the cells) in nephroblastoma, which also complicates the treatment of the patient and which cannot be solved when only one sample is taken from the tumor. In this work we concentrated on the detection of chromosomal changes present in nephroblastomas of 44 patients and their associations with clinical data. We have proved some of the known associations (22q...

Orientadores: Laurecir Gomes, Maria Tereza Cartaxo Muniz / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-26T03:40:26Z (GMT). No. of bitstreams: 1 Arruda_IzabelBarrosde_D.pdf: 1365851 bytes, checksum: 2a1a28a0a33d73a75e48051e8b746627 (MD5) Previous issue date: 2014 / Resumo: O tumor de Wilms é uma neoplasia embrionária, originada de células do blastema metanéfrico, sendo histologicamente caracterizado como tumor trifásico, pois as células blastematosas, estromais e epiteliais estão presentes em proporções variáveis, com grande diversidade de arranjo celular e graus de diferenciação com ou sem anaplasia. Este tumor está associado a síndromes genéticas e a malformações do trato geniturinário. O objetivo desta tese foi avaliar as alterações nos genes WT1 e WT2 e a relação do índice apoptótico com o estadiamento tumoral. Para investigação das alterações nos genes WT1 e WT2 foi utilizada o método FISH, a imunorreatividade das proteínas WT1, p53 e MMP-2 foi empregada imunoistoquímica e para detectar células em apoptose, utilizou-se o método TUNEL. Os resultados evidenciaram cópias extras dos genes WT1 e WT2, com citogenética molecular nuc ish (WT1x3),(WT2x3) [100%], sugerindo que a evidencia da cópia-extra do gene WT2 pode ser explicada por trissomia ou por isodissomia uniparental, porém a presença da cópia-extra do WT1, até o momento, não foi relatada em qualquer caso clínico na literatura, sendo necessários mais estudos que a justifiquem. Por imunohistoquímica, constatou-se intensa imunomarcação no tumor para WT1 (80%), p53 (96,4%), assim como no estroma e ao redor do tumor, para MMP-2 (97%). Possivelmente essa alta expressão de WT1 pode estar refletindo a perda da regulação desse gene no desenvolvimento normal celular. A detecção da p53 neste estudo pode indicar a mutação do gene TP53, sugerindo que os tumores de Wilms poderiam progredir para anaplasia, após adquirem mutação do TP53, porém não como um evento isolado. Outros eventos seriam necessários para esta progressão, como a perda do alelo normal do TP53. A alta expressão da MMP-2 no estroma e ao redor do tumor não implica em sua atividade proteolítica, já que essa proteína pode estar em sua forma latente como também ativa e a técnica imunohistoquímica utilizada neste trabalho não diferencia essas formas. Não se identificou diferença significativa do índice apoptótico segundo estadio tumoral (p=0,937), mas os tumores em estadio III apresentaram índice seis vezes menor o daqueles em estadio II, em ausência de neoadjuvância, proporção que aumentou para 29 vezes, na presença de quimioterapia neoadjuvante, parecendo indicar que a neoadjuvância pode interferir sobre os mecanismos envolvidos na apoptose / Abstract: Wilms' tumor is an embryonic neoplasm arising from cells of the metanephric blastema, being histologically characterized as three-phase tumor, because blastematosas, stromal and epithelial cells are present in varying proportions, with great diversity of cell arrangement and degree of differentiation with or without anaplasia. This tumor is associated with genetic syndromes and malformations of the genitourinary tract. The aim of this thesis was to evaluate changes in WT1 and WT2 genes and the ratio of apoptotic cells to tumor staging. For investigation of changes in both WT1 and WT2 genes, the FISH method was used for immunoreactivity of the WT1 p53 and MMP-2 protein was employed and immunohistochemistry to detect cells undergoing apoptosis, we used the TUNEL. The results showed extra copies of WT1 and WT2 genes, with molecular cytogenetic nuc ish (WT1x3), (WT2x3) [100%], suggesting that the evidence of extra copy of WT2 gene can be explained by trisomy or uniparental isodisomy, but the presence of extra copy of WT1, so far, has not been reported in any clinical case in the literature, being necessary more studies to justify it. By immunohistochemistry, intense immunostaining was found in the tumor WT1 (80%), p53 (96.4%) as well as in the stroma surrounding the tumor, MMP-2 (97%). Possibly this high expression of WT1 may reflect the loss of regulation of this gene in the normal cell development. The detection of p53 in this study may indicate the mutation of the TP53 gene, suggesting that the Wilms' tumors may progress to anaplasia, after acquiring mutation of TP53, but not as an isolated event. Other events are needed for this progression, as loss of the normal allele of TP53. The high expression of MMP-2 in the stroma and around the tumor does not imply its proteolytic activity, since this protein may be at its latent form as well as active and the immunohistochemical technique used in this study does not differentiate these forms. There was no significant difference in the apoptotic index according to the tumor stage (p = 0.937), but in stage III tumors showed rate six times smaller than those in the stage II, in the absence of neoadjuvant therapy, rising to 29 times in the presence of chemotherapy neoadjuvant, seeming to indicate that neoadjuvant therapy may interfere with the mechanisms involved in apoptosis / Doutorado / Biologia Celular / Doutora em Biologia Celular e Estrutural

The described experimental model of clonal tumors induced through the insertional mutagenesis with MAV-2 proved to be a valid and rich source of information describing the process of transformation of normal into tumor cell. We have mapped more than 2000 individual clonal VISs from several hundreds of tumor tissue samples. We have analyzed five tumor types of different histology and tissue of origin along with their derivative tissue cultures. Furthermore, we have discovered the industasis phenomenon and described it during the course of the study. The goal of my study was to uncover common reasons for neoplastic transformation of the cell. The results of my study led me to the paradoxical conclusion that the significance of genetic changes as the primary cause of induction of neoplastic transformation is being overestimated. Although studying the functions of individual genes and search for new tumor markers and therapeutical targets are still beneficial, I believe that the traditional perception of tumor formation as a function/result of mutation accumulation and selection is becoming a serious drawback in further investigations. These conclusions are further discussed in the last section of the presented Ph.D. thesis.