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Biomedical subjects

N Graf

Publications and source records attributed to N Graf.

At least 19 recordsLinked to original sources
PubMed2006

Expression profiling of Wilms tumors reveals new candidate genes for different clinical parameters.

Wilms tumor is the most frequent renal neoplasm in children, but our understanding of its genetic basis is still limited. We performed cDNA microarray experiments using 63 primary Wilms tumors with the aim of detecting new candidate genes associated with malignancy grade and tumor progression. All tumors had received preoperative chemotherapy as mandated by the SIOP protocol, which sets this study apart from related approaches in the Unites States that are based on untreated samples. The stratification of expression data according to clinical criteria allowed a rather clear distinction between different subsets of Wilms tumors. Clear-cut differences in expression patterns were discovered between relapse-free as opposed to relapsed tumors and tumors with intermediate risk as opposed to high risk histology. Several differentially expressed genes, e.g.TRIM22, CENPF, MYCN, CTGF, RARRES3 and EZH2, were associated with Wilms tumor progression. For a subset of differentially expressed genes, microarray data were confirmed by real-time RT-PCR on the original set of tumors. Interestingly, we found the retinoic acid pathway to be deregulated at different levels in advanced tumors suggesting that treatment of these tumors with retinoic acid may represent a promising novel therapeutic approach.

Disease Progression↗
PubMed2006

Two infants with life-threatening diffuse neonatal hemangiomatosis treated with cyclophosphamide.

Diffuse neonatal hemangiomatosis (DNH) is a rare, frequently fatal disorder characterized by multiple cutaneous and visceral hemangiomas. Complications include high-output cardiac failure, hemorrhage, hepatic failure, and consumption coagulopathy. We present two cases of neonates with DNH. We prescribed cyclophosphamide after failure of corticosteroids. Cyclophosphamide induced a fast regression of the lesions with no side effects in both infants. We were able to stop treatment after 3-4 courses of cyclophosphamide in both infants because of the excellent response. Cyclophosphamide seems to be a safe and effective treatment in patients suffering from life-threatening DNH unresponsive to corticosteroids.

Adrenal Cortex Hormones↗
PubMed2006

[Reference radiology in nephroblastoma: accuracy and relevance for preoperative chemotherapy].

PURPOSE: A reference radiologic diagnosis was carried out for the purpose of quality control and in order to achieve high diagnostic accuracy in the ongoing trial and study SIOP 2001/GPOH for renal tumors during childhood. The aim of the present study is to evaluate the value of diagnostic imaging and the benefit of reference evaluation at a pediatric radiology center. MATERIALS AND METHODS: In 2004 the imaging studies of 97 patients suspected of having a renal tumor were presented at the beginning of therapy. Diagnostic imaging was compared to the primary imaging results and the histological findings and was analyzed in regard to the therapeutic consequence (primary chemotherapy without prior histology). 77 MRI, 35 CT and 67 ultrasound examinations of 47 girls and 50 boys (mean age 4 years; one day to 15.87 years old) were analyzed. In addition to the histological findings, the reference pathological results were submitted in 86 cases. Results from the primary imaging corresponding to the histology and results from the reference radiology corresponding to the histology were statistically compared in a binomial test. RESULTS: In 76 of the reference-diagnosed Wilms' tumors, 67 were confirmed histologically. In 72 cases preoperative chemotherapy was initiated. In 5 cases neither a Wilms' tumor nor a nephroblastomatosis was found. 16 of 21 cases (76 %) with reference-diagnosed non-Wilms' tumors were selected correctly. The results of the primary imaging corresponded to the histology in 71 cases, and those of the reference radiology in 82 cases. The statistical evaluation showed that the results of the reference radiology were significantly better (p = 0.03971). CONCLUSION: Reference radiological evaluation improved the diagnostic accuracy with therapeutic relevance. The differentiation of different renal tumors is not completely possible using imaging methods. The rate of patients with false preoperative chemotherapy for all renal neoplasms is currently 5.2 % and 1 % for benign renal tumors.

Antineoplastic Agents↗
PubMed2005

[Childhood kidney tumors -- the relevance of imaging].

Kidney tumors represent 6.2% of malignant tumors in children. History, clinical course and radiological findings are necessary elements in the differential diagnosis of the different renal tumors. In the case of nephroblastoma, chemotherapy is based solely on the radiological diagnosis without prior histology. In therapy-optimizing studies of the Society of Pediatric Oncology and Hematology, preoperative chemotherapy is performed. Therapy monitoring is performed in the course of and after preoperative chemotherapy to verify tumor response. Radiological staging plays a significant role in deciding on further treatment and in operative planning. Three-dimensional visualization of the abdominal situs can assist preoperative planning. In summary, diagnostic imaging in renal tumors in children plays a role in differential diagnosis, staging, monitoring of therapy, and surgical planning.

Abnormalities, Multiple↗
PubMed2005

[Radiologic differentiation of rhabdoid tumor from Wilms' tumor and mesoblastic nephroma].

Differentiation between rhabdoid tumor (RT) and mesoblastic nephroma (MN) and Wilms' tumor (WT) by imaging studies in babies and young children before histological confirmation is useful to start optimal treatment early. Typical radiologic criteria (crescent-shaped subcapsular liquid areas, tumor lobules, blurred tumor borders, metastasis in the lung, and regional lymph nodes) are described. The results of 26 MRI, 30 CT, and 22 ultrasound examinations of 49 patients (22 RT, 19 WT, and 8 MN, age 2-57 months) were analyzed. The above-mentioned radiologic criteria were classified with score values. The score value distribution was analyzed between the tumor entities and by two investigators.RT had significantly higher score values than the MN and WT. The difference between the two investigators was not significant. As a group RT differentiates from the group of WT and MN, but this is not possible in single cases with the radiologic criteria employed. Only if more signs are observed together in one case can a RT be presumed, which may indicate an early biopsy before chemotherapy.

Child, Preschool↗
PubMed2005

[MRI-morphology and staging of congenital mesoblastic nephroma: evaluation of a collection with 20 patients].

PURPOSE: To differentiate classic and cellular type of congenital mesoblastic nephroma (CMN) in MRI and to evaluate MRI for staging according to the Societe Internationale de Oncologie Pediatrique (SIOP). MATERIAL AND METHODS: MRI examinations of 20 children with CMN (age 1st to 16th months, classic type n = 11, cellular type n = 7, mixed type n = 2) were analyzed retrospectively. Cysts, necrosis, hemmorhage in the tumor, signal intensity, tumor structure, thrombosis and dilatation of renal vein, crossing of the body midline, peripheral contrast-enhancement, tumor volume and existence of a tumor pseudocapsule in contrast to the residual kidney were described. The radiologic stage was compared with the histopathologic stage (infiltration of perirenal fat and infiltration of the renal sinus). RESULTS: Tumors of the classic type (mean volume 67.9 ml) had necrosis in 1 case, crossed the midline in 1 case, had no cysts or bleeding, and had a peripheral contrast-enhancement in 1 case, and were heterogeneous in 9 cases. The cellular type (mean volume 302.8 ml) had tumor necrosis in 6 cases, bleeding in 3 cases, cysts in 3 cases, crossed the midline in 4 cases, and peripheral contrast enhancement in 2 cases, and was predominantly heterogeneous. Mixed tumor types (7 ml and 202 ml) had tumor necrosis in 1 case and crossed the midline in 1 case, a peripheral contrast enhancement in 2 cases and a homogenous structure in 1 case. The signal intensity in T1 w and T2 w images was not specific. The renal vein was inconspicuous in all children. The evaluation of the infiltration in perirenal fatty tissue was true positive in 1 case, true negative in 10 cases, false negative in 4 cases and false positive in 5 cases. The infiltration of the renal hilus was true positive in 10 children, false positive in 8 cases and true negative in 2 cases. CONCLUSION: A typical finding of CMN in MRI is a heterogeneous tumor without demarcation from the rest of the kidney parenchyma by a pseudocapsule. The cellular type of CMN tends to have a higher tumor volume and shows more necrosis, bleeding and cysts than the classic type in MRI. A peripheral contrast-enhancement in MRI is not characteristic for any type of CMN. Local tumor staging is not possible with MRI.

Diagnosis, Differential↗
PubMed2005

Effects of short-term propofol administration on pancreatic enzymes and triglyceride levels in children.

This prospective, clinical trial evaluated the effects of short-term propofol administration on triglyceride levels and serum pancreatic enzymes in children undergoing sedation for magnetic resonance imaging. Laboratory parameters of 40 children, mean age (SD; range) 67 (66; 4-178) months undergoing short-term sedation were assessed before and 4 h after having received propofol. Mean (SD) propofol loading dose was 2.2 (1.1) mg.kg(-1) followed by continuous propofol infusion of 6.9 (0.9) mg.kg(-1).h(-1). Serum lipase levels (p = 0.035) and serum triglyceride levels (p = 0.003) were raised significantly after propofol administration but remained within normal limits. No significant changes in serum pancreatic-amylase levels were seen (p = 0.127). In two (5%) children, pancreatic enzymes and in four (10%) children triglyceride levels were raised above normal limits; however, no child showed clinical symptoms of pancreatitis. We conclude that even short-term propofol administration with standard doses of propofol may have a significant effect on serum triglyceride and pancreatic enzyme levels in children.

Adolescent↗
PubMed2004

Intracranial relapse in Wilms tumor patients.

BACKGROUND: In children with nephroblastoma, recurrence with metastases in the central nervous system is rare. Recently, previous reports (NWTSG and UKCCSG) reported brain metastases with an incidence of respectively 0.5% and 0.6% in Wilms tumor (WT) patients (respectively n = 30/5,852 and n = 7/1,249). PROCEDURE: We retrospectively investigated the incidence and survival of patients with central nervous system relapse in WT patients, treated according to the consecutive SIOP protocols 1, 2, 5, 6, 9, and 93-01. All children with WT from 1971 until 2000 were enrolled in the study (3,040 eligible patients). Specimens at diagnosis and if possible at relapse were centrally reviewed. Patients with renal neoplasms other than WT were excluded. RESULTS: CNS relapse was documented in 14 patients (0.5%). Median time to CNS relapse was 16 months (3-69). The occurrence of relapse was not associated with specific histological subtypes. In seven patients intracranial metastases occurred at first relapse, of which two were isolated relapses. In five patients no treatment was started because of the poor condition of the patient, the other nine cases were treated with (a combination of) chemotherapy (n = 6), surgery (n = 4), and radiotherapy (n = 6). CONCLUSIONS: CNS relapse in WNT is rare. In contrast to reports of other Wilms tumor study groups, although four patients reached (local) CR, the SIOP registry showed that eventually none of the documented WT patients survived.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2004

[Prognosis of Wilm's tumor in the course of the SIOP trials and studies].

Wilms' tumor is the most common malignant renal tumor in children. Dramatic improvements in survival have occurred as the result of advances in anesthetic and surgical management, irradiation, and chemotherapy. Today treatments are based on several multicenter trials and studies conducted by the SIOP in Europe and NWTS in the USA. The main objectives of these trials and studies are to treat patients according to well-defined risk groups in order to achieve the highest cure rates, to decrease the frequency and intensity of acute and late toxicity, and to minimize the cost of therapy. The SIOP trials and studies largely focus on the issue of preoperative therapy whereas patients treated according to NWTS are primarily operated.

Adolescent↗
PubMed2004

[Rhabdoid tumors of the kidney in childhood].

PURPOSE: The primary diagnosis of renal masses in children is made by imaging studies. This retrospective analysis describes the imaging features of rhabdoid tumors (RT) with US, CT and MRI, to point out characteristics and to evaluate the possibility of differentiation between RT and Wilms tumor. MATERIALS AND METHODS: We reviewed 10 MRI (6 STIR, 9 T1 w, 8 T2 w, 10 T1 post KM), 15 CT (9 Nativ-CT, 14 KM-CT) and 14 US images of 22 patients (age 2 - 57 months) with histopathologically confirmed RT. The following characteristics were evaluated: subcapsular fluid collection, multiple tumor lobules, presence of calcification, primary tumor size, visibility of tumor margin, tumor necrosis and metastases. RESULTS: The mean total tumor volume was 238 ml. 19 RT were located in the perihilar/medullary region with invasion of the renal hilum, and 5/22 tumors showed multiple tumor lobules. Subcapsular fluid collection was found in 6/22 cases. Calcifications were present in 6/19. Eleven tumors were well defined from the renal parenchyma, 9 poorly defined, 2 could not be assessed. In 19/22 cases tumor necrosis was found. Distant metastases were seen in 8 cases in the lung, in 3 cases in the CNS. Metastases of regional lymph nodes were seen in 9 cases. CONCLUSION: The evaluated characteristics frequently found in RT are not indicative of these tumors. RT cannot clearly be differentiated from Wilms tumor by imaging studies. Because of frequent involvement of the CNS and lung, a MRI of the CNS and CT of the lung is indicated after histopathologic diagnosis of RT is made.

Child, Preschool↗
PubMed2004

[3D-visualization by MRI for surgical planning of Wilms tumors].

PURPOSE: To improve surgical planning of kidney tumors in childhood (Wilms tumor, mesoblastic nephroma) after radiologic verification of the presumptive diagnosis with interactive colored 3D-animation in MRI. MATERIALS AND METHODS: In 7 children (1 boy, 6 girls) with a mean age of 3 years (1 month to 11 years), the MRI database (DICOM) was processed with a raycasting-based 3D-volume-rendering software (VG Studio Max 1.1/Volume Graphics). The abdominal MRI-sequences (coronal STIR, coronal T1 TSE, transverse T1/T2 TSE, sagittal T2 TSE, transverse and coronal T1 TSE post contrast) were obtained with a 0.5T unit in 4 - 6 mm slices. Additionally, a phase-contrast-MR-angiography was applied to delineate the large abdominal and retroperitoneal vessels. A notebook was used to demonstrate the 3D-visualization for surgical planning before surgery and during the surgical procedure. RESULTS: In all 7 cases, the surgical approach was influenced by interactive 3D-animation and the information found useful for surgical planning. Above all, the 3D-visualization demonstrates the mass effect of the Wilms tumor and its anatomical relationship to the renal hilum and to the rest of the kidney as well as the topographic relationship of the tumor to the critical vessels. One rupture of the tumor capsule occurred as a surgical complication. For the surgeon, the transformation of the anatomical situation from MRI to the surgical situs has become much easier. CONCLUSION: For surgical planning of Wilms tumors, the 3D-visualization with 3D-animation of the situs helps to transfer important information from the pediatric radiologist to the pediatric surgeon and optimizes the surgical preparation. A reduction of complications is to be expected.

Age Factors↗
PubMed2004

Survival in nephroblastoma treated according to the trial and study SIOP-9/GPOH with respect to relapse and morbidity.

BACKGROUND: Recent Wilms' tumor (WT) trials and studies have tried to determine the minimal therapy needed for cure. The goal was survival without morbidity. PATIENTS AND METHODS: From January 1989 to March 1994 the German Society of Pediatric Oncology and Hematology registered 440 patients (median age 2.9 years; 231 male, 209 female) with WTs (preoperative chemotherapy 362) for therapy according to the International Society of Pediatric Oncology Trial and Study 9. Therapy for relapse depended on site of relapse and therapy already received. Follow-up included inquiries for morbidity. Prognostic factors for relapse and death were evaluated. RESULTS: Five-year survival of WTs was 89.5%; 98.2% (385 of 392) of survivors had a follow-up of 5 years (range 0.8-12.6; median 8). In non-anaplastic WTs, young age (<2 years) was of significance (P = 0.026) for a better survival. Non-anaplastic WTs (407 patients) had a 5-year survival of 92.3%, versus 48.5% in anaplastic WTs (33 patients), and a 5-year relapse-free survival of 87.6% versus 42.4%. Survival after relapse was significantly worse for anaplastic than for non-anaplastic WTs (residual 3-year survival 11.8% versus 54.3%; P <0.0001). In preoperatively treated WTs, anaplasia was a strong prognostic factor for death [relative risk (RR) 4.7], followed by poor response to preoperative therapy (RR 3.6), stage IV (RR 3.2) and abdominal stage III (RR 2.2). Low abdominal stages (<III) dominated (280 versus 82). In the 334 unilateral stage I-IV WTs (median age 3.2 years), diffuse anaplasia (21 patients) had a 5-year relapse-free survival of 38.1%, versus 58.4% in blastemal WTs (25 patients); survival was 42.9% in diffuse anaplasia versus 84% in blastemal WTs. None of 46 patients (median age 1.9 years; 91.3% stages I or II) with differentiated WTs (nine epithelial, 37 stromal) relapsed despite their non-response; two died (one therapy related, one due to bilaterization). In the 25 non-anaplastic bilateral WTs, differentiated cases (one epithelial, eight stromal, 33.3% abdominal stage III) were more frequent (P = 0.048) than in unilateral WTs (one stromal, abdominal stage III relapsed). In all, 52.9% of the 5-year survivors had received adriamycin (250-400 mg/m(2)), 25.7% radiation, 6.4% ifosfamide (24-30 g/m(2)) and 6.7% carboplatin plus etoposide. Abnormal parameters according to the National Cancer Institute score were seen in 18.9% during follow-up, but only 6.4% were treated for morbidity at the end of follow-up. Three WTs developed renal failure due to Drash syndrome, but none due to tumor therapy. After adriamycin 1.9% of WTs (9% of those receiving 400 mg/m(2)) required therapy for cardiac toxicity. CONCLUSIONS: Initial therapy should be more individualized, taking the above risk groups (age in non-anaplastic WTs, poor response, anaplasia, etc.) into account, as morbidity even after relapse therapy with ifosfamide, carboplatin and etoposide was not high. Milder therapy in low stages of differentiated and of well responding WTs should be tested.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2004

A meta-model of chemotherapy planning in the multi-hospital/multi-trial-center-environment of pediatric oncology.

OBJECTIVE: Chemotherapy planning in pediatric oncology is complex and time-consuming. The correctness of the calculation according to state-of-the-art research is crucial for curing the child. Computer-assistance can be of great value. The objective of our research was to work out a meta-model of chemotherapy planning based on the Unified Modeling Language (UML). The meta-model is used for the development of an application system which serves as a knowledge-acquisition tool for chemotherapy protocols in pediatric oncology as well as for providing protocol-based care. METHODS: We applied evolutionary prototyping, software reengineering techniques and grounded theory, a qualitative method in social research. We repeated the following steps several times over the years: Based on a requirements analysis (i) a meta-model was developed or adapted, respectively (ii). The meta-model served as a basis for implementing evolutionary prototypes (iii). Further requirements were identified (i) from clinical use of the systems. RESULTS: We developed a comprehensive UML-based meta-model for chemotherapy planning in pediatric oncology (chemoMM). We implemented it and introduced evolutionary prototypes (CATIPO and DOSPO) in several medical centers. Systematic validation of the prototypes enabled us to derive a final meta-model which covers the requirements that have turned out to be necessary in clinical routine. CONCLUSIONS: We have developed an application system that fits well into clinical routine of pediatric oncology in Germany. Validation results have shown that the implementation of the meta-model chemoMM can adequately support the knowledge acquisition process for protocol-based care.

Antineoplastic Agents↗
PubMed2003

[Supratentorial tumors in childhood].

In Germany about 400 children are diagnosed of having a brain tumour each year. About half of them are located in the supratentorial region. Despite the fact, that brain tumours are the most common solid tumour in childhood, they are very heterogeneous, regarding clinical symptoms, pathology, treatment and prognosis. Imaging studies play an important role for diagnosis and follow-up.

Adolescent↗
PubMed2002

Multicentre analysis of anthracycline-induced cardiotoxicity in children following treatment according to the nephroblastoma studies SIOP No.9/GPOH and SIOP 93-01/GPOH.

BACKGROUND: To study cardiac function and the incidence of anthracycline-induced cardiotoxicity in children following treatment according to the nephroblastoma studies SIOP No.9/GPOH and SIOP 93-01/GPOH. PROCEDURE: Analysis of clinical status, echocardiography, and ECG findings prior to administration of anthracyclines (median cumulative doxorubicin dose: 250 mg/m(2) [range: 90-411 mg/m(2)] and after a median posttherapeutic interval of 2.9 years [range: 0-10.2 years]. Data on cardiac function before and/or after therapy could be obtained of 186 patients. RESULTS: Posttherapy left ventricular fractional shortening was reduced in 4/157 (2.5%) patients. Out of the 4 children, 2 had clinically reduced tolerance to exercise and received anticongestive therapy. Abnormal ECG findings that were not detectable prior to therapy were found in 7/124 (5.6%) children. CONCLUSIONS: The incidence of abnormal findings is low in our study group in comparison to data from the literature and might be due to the comparably short posttherapeutic interval.

Adolescent↗