Screening over Speech in Unselected Populations for Clinical Trials in AD (PROSPECT-AD): Study Design and Protocol

BACKGROUND

Speech impairments are an early feature of Alzheimer's disease (AD) and consequently, analysing speech performance is a promising new digital biomarker for AD screening. Future clinical AD trials on disease modifying drugs will require a shift to very early identification of individuals at risk of dementia. Hence, digital markers of language and speech may offer a method for screening of at-risk populations that are at the earliest stages of AD, eventually in combination with advanced machine learning. To this end, we developed a screening battery consisting of speech-based neurocognitive tests. The automated test performs a remote primary screening using a simple telephone.

OBJECTIVES

PROSPECT-AD aims to validate speech biomarkers for identification of individuals with early signs of AD and monitor their longitudinal course through access to well-phenotyped cohorts.

DESIGN

PROSPECT-AD leverages ongoing cohorts such as EPAD (UK), DESCRIBE and DELCODE (Germany), and BioFINDER Primary Care (Sweden) and Beta-AARC (Spain) by adding a collection of speech data over the telephone to existing longitudinal follow-ups. Participants at risk of dementia are recruited from existing parent cohorts across Europe to form an AD 'probability-spectrum', i.e., individuals with a low risk to high risk of developing AD dementia. The characterization of cognition, biomarker and risk factor (genetic and environmental) status of each research participants over time combined with audio recordings of speech samples will provide a well-phenotyped population for comparing novel speech markers with current gold standard biomarkers and cognitive scores.

PARTICIPANTS

N= 1000 participants aged 50 or older will be included in total, with a clinical dementia rating scale (CDR) score of 0 or 0.5. The study protocol is planned to run according to sites between 12 and 18 months.

MEASUREMENTS

The speech protocol includes the following neurocognitive tests which will be administered remotely: Word List [Memory Function], Verbal Fluency [Executive Functions] and spontaneous free speech [Psychological and/ or behavioral symptoms]. Speech features on the linguistic and paralinguistic level will be extracted from the recordings and compared to data from CSF and blood biomarkers, neuroimaging, neuropsychological evaluations, genetic profiles, and family history. Primary candidate marker from speech will be a combination of most significant features in comparison to biomarkers as reference measure. Machine learning and computational techniques will be employed to identify the most significant speech biomarkers that could represent an early indicator of AD pathology. Furthermore, based on the analysis of speech performances, models will be trained to predict cognitive decline and disease progression across the AD continuum.

CONCLUSION

The outcome of PROSPECT-AD may support AD drug development research as well as primary or tertiary prevention of dementia by providing a validated tool using a remote approach for identifying individuals at risk of dementia and monitoring individuals over time, either in a screening context or in clinical trials.

Spinal cord synaptic plasticity by GlyRβ release from receptor fields and syndapin I-dependent uptake

Glycine receptor-mediated inhibitory neurotransmission is key for spinal cord function. Recent observations suggested that by largely elusive mechanisms also glycinergic synapses display synaptic plasticity. We imaged receptor fields at ultra-high resolution at freeze-fractured membranes, tracked surface and internalized glycine receptors (GlyR) and studied differential regulations of GlyRβ interactions with the scaffold protein gephyrin and the F-BAR domain protein syndapin I and thereby reveal key principles of this process. S403 phosphorylation of GlyRβ, known to be triggered by synaptic signaling, caused a decoupling from gephyrin scaffolds but simultaneously promoted association of syndapin I with GlyRβ. In line, kainate-treatments used to trigger rearrangements of glycine receptors in murine syndapin I KO spinal cords (mixed sex) showed even more severe receptor field fragmentation than already observed in untreated syndapin I KO spinal cords. Syndapin I KO furthermore resulted in more dispersed receptors and increased receptor mobility also pointing out an important contribution of syndapin I in the organization of GlyRβ fields. Strikingly, syndapin I KO also led to a complete disruption of kainate-induced GlyRβ internalization. Accompanying quantitative ultra-high resolution studies in dissociated spinal cord neurons strongly suggested that the observed defects in GlyR internalization observed in syndapin I KO spinal cords are directly caused by syndapin I deficiency within murine spinal cord neurons. Together our results unveiled important mechanisms organizing and altering glycine receptor fields during both steady-state and particularly upon kainate-induced synaptic rearrangement - principles organizing and fine-tuning synaptic efficacy and plasticity of glycinergic synapses in the spinal cord.SIGNIFICANCE STATEMENTInitial observations suggested that also glycinergic synapses - key for spinal cord and brain stem functions - may display some form of synaptic plasticity. Imaging receptor fields at ultra-high resolution at freeze-fractured membranes, tracking surface and internalized glycine receptors (GlyR) and studying regulations of GlyRβ interactions we here reveal key principles of these kainate-inducible adaptations. A switch from gephyrin-mediated receptor scaffolding to syndapin I-mediated GlyRβ scaffolding and internalization allows for modulating synaptic receptor availability. In line, kainate-induced GlyRβ internalization was completely disrupted and GlyRβ receptor fields were distorted upon syndapin I KO. These results unveiled important mechanisms during both steady-state and kainate-induced alterations of synaptic GlyR fields - principles underlying synaptic efficacy and plasticity of synapses in the spinal cord.

Comparison of Multiscale Imaging Methods for Brain Research

A major challenge in neuroscience is how to study structural alterations in the brain. Even small changes in synaptic composition could have severe outcomes for body functions. Many neuropathological diseases are attributable to disorganization of particular synaptic proteins. Yet, to detect and comprehensively describe and evaluate such often rather subtle deviations from the normal physiological status in a detailed and quantitative manner is very challenging. Here, we have compared side-by-side several commercially available light microscopes for their suitability in visualizing synaptic components in larger parts of the brain at low resolution, at extended resolution as well as at super-resolution. Microscopic technologies included stereo, widefield, deconvolution, confocal, and super-resolution set-ups. We also analyzed the impact of adaptive optics, a motorized objective correction collar and CUDA graphics card technology on imaging quality and acquisition speed. Our observations evaluate a basic set of techniques, which allow for multi-color brain imaging from centimeter to nanometer scales. The comparative multi-modal strategy we established can be used as a guide for researchers to select the most appropriate light microscopy method in addressing specific questions in brain research, and we also give insights into recent developments such as optical aberration corrections.

Syndapin I Loss-of-Function in Mice Leads to Schizophrenia-Like Symptoms

Schizophrenia is associated with cognitive and behavioral dysfunctions thought to reflect imbalances in neurotransmission systems. Recent screenings suggested that lack of (functional) syndapin I (PACSIN1) may be linked to schizophrenia. We therefore studied syndapin I KO mice to address the suggested causal relationship to schizophrenia and to analyze associated molecular, cellular, and neurophysiological defects. Syndapin I knockout (KO) mice developed schizophrenia-related behaviors, such as hyperactivity, reduced anxiety, reduced response to social novelty, and an exaggerated novel object response and exhibited defects in dendritic arborization in the cortex. Neuromorphogenic deficits were also observed for a schizophrenia-associated syndapin I mutant in cultured neurons and coincided with a lack of syndapin I–mediated membrane recruitment of cytoskeletal effectors. Syndapin I KO furthermore caused glutamatergic hypofunctions. Syndapin I regulated both AMPAR and NMDAR availabilities at synapses during basal synaptic activity and during synaptic plasticity—particularly striking were a complete lack of long-term potentiation and defects in long-term depression in syndapin I KO mice. These synaptic plasticity defects coincided with alterations of postsynaptic actin dynamics, synaptic GluA1 clustering, and GluA1 mobility. Both GluA1 and GluA2 were not appropriately internalized. Summarized, syndapin I KO led to schizophrenia-like behavior, and our analyses uncovered associated molecular and cellular mechanisms.

An AKAP-Lbc-RhoA interaction inhibitor promotes the translocation of aquaporin-2 to the plasma membrane of renal collecting duct principal cells

Stimulation of renal collecting duct principal cells with antidiuretic hormone (arginine-vasopressin, AVP) results in inhibition of the small GTPase RhoA and the enrichment of the water channel aquaporin-2 (AQP2) in the plasma membrane. The membrane insertion facilitates water reabsorption from primary urine and fine-tuning of body water homeostasis. Rho guanine nucleotide exchange factors (GEFs) interact with RhoA, catalyze the exchange of GDP for GTP and thereby activate the GTPase. However, GEFs involved in the control of AQP2 in renal principal cells are unknown. The A-kinase anchoring protein, AKAP-Lbc, possesses GEF activity, specifically activates RhoA, and is expressed in primary renal inner medullary collecting duct principal (IMCD) cells. Through screening of 18,431 small molecules and synthesis of a focused library around one of the hits, we identified an inhibitor of the interaction of AKAP-Lbc and RhoA. This molecule, Scaff10-8, bound to RhoA, inhibited the AKAP-Lbc-mediated RhoA activation but did not interfere with RhoA activation through other GEFs or activities of other members of the Rho family of small GTPases, Rac1 and Cdc42. Scaff10-8 promoted the redistribution of AQP2 from intracellular vesicles to the periphery of IMCD cells. Thus, our data demonstrate an involvement of AKAP-Lbc-mediated RhoA activation in the control of AQP2 trafficking.

Deciphering caveolar functions by syndapin III KO-mediated impairment of caveolar invagination

Several human diseases are associated with a lack of caveolae. Yet, the functions of caveolae and the molecular mechanisms critical for shaping them still are debated. We show that muscle cells of syndapin III KO mice show severe reductions of caveolae reminiscent of human caveolinopathies. Yet, different from other mouse models, the levels of the plasma membrane-associated caveolar coat proteins caveolin3 and cavin1 were both not reduced upon syndapin III KO. This allowed for dissecting bona fide caveolar functions from those supported by mere caveolin presence and also demonstrated that neither caveolin3 nor caveolin3 and cavin1 are sufficient to form caveolae. The membrane-shaping protein syndapin III is crucial for caveolar invagination and KO rendered the cells sensitive to membrane tensions. Consistent with this physiological role of caveolae in counterpoising membrane tensions, syndapin III KO skeletal muscles showed pathological parameters upon physical exercise that are also found in CAVEOLIN3 mutation-associated muscle diseases.

A-kinase anchoring proteins as potential drug targets

A-kinase anchoring proteins (AKAPs) crucially contribute to the spatial and temporal control of cellular signalling. They directly interact with a variety of protein binding partners and cellular constituents, thereby directing pools of signalling components to defined locales. In particular, AKAPs mediate compartmentalization of cAMP signalling. Alterations in AKAP expression and their interactions are associated with or cause diseases including chronic heart failure, various cancers and disorders of the immune system such as HIV. A number of cellular dysfunctions result from mutations of specific AKAPs. The link between malfunctions of single AKAP complexes and a disease makes AKAPs and their interactions interesting targets for the development of novel drugs. LINKED ARTICLES This article is part of a themed section on Novel cAMP Signalling Paradigms. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.166.issue-2.

Surgical complications in abdominal tumor surgery in children. Experiences at a single oncological center

INTRODUCTION

Surgical complications after tumor operations are frequent in children, with rates of up to 30% cited in the literature. Various approaches to reduce these complication rates have been attempted, with preoperative chemotherapy holding pride of place. One approach to minimize surgical complications is better preoperative preparation. In a retrospective analysis, we evaluated the complications associated with tumor surgery.

MATERIAL AND METHODS

We retrospectively analyzed patient data from 1991 to 2007. The distribution of the various tumors, the type of surgery, and complications were evaluated. For neuroblastomas a differentiated analysis of complications was performed, which included staging and radiologically defined surgical risk factors (SRFs). Patients were divided into two groups: A and B. Intensified surgical planning with 3D visualization was used in patients of group B.

RESULTS

A total of 145 operations for abdominal tumors were performed in 123 patients. The three most common diseases were neuroblastoma (36%), nephroblastoma (26%), and ovarian tumor (19%). In 68% of patients complete resection and in 19% of cases partial resection of the tumor was carried out; open biopsy was performed in 13%. A total of 15 (10.3%) complications developed: the incidence of complications for group A was 11.8% and 7.7% for group B (p=0.5). For nephroblastoma these figures were 27.9% and 21.2% (p=1.0). In the group of patients with neuroblastoma, six complications developed in patients from group A (21.4%) and one in a group B patient (4.2%) (p=0.107). 54% of neuroblastomas were completely and 33% partially resected; these figures and the distribution of SRFs were similar in the two groups. A significant increase in the risk of complications could be seen with an increase in SRFs (p=0.0267) and with disease stages 2 and 3 (p=0.016). Tumor reduction surgery was also associated with an increase in complications (p=0.086).

CONCLUSIONS

In summary, tumor surgery is associated with considerable risks in children. Therefore it is very important to look for new approaches that could potentially minimize these risks. As the causes of surgical complications are multifactorial, we are of the opinion that intensified surgical planning can contribute to reducing risks. Particularly neuroblastoma surgery could profit from an increased use of 3D visualization and improved preoperative planning.

3D perfusion mapping and virtual surgical planning in the treatment of pediatric embryonal abdominal tumors

INTRODUCTION

3D imaging and surgical planning for the treatment of embryonal tumors using different techniques (CT versus MRI) are presently under discussion. Up to now, the main focus has been on visualizing the anatomy. Contrast medium dynamics have not been taken into consideration. The aim of the present study was to establish the technical means of integrating the 3D images from functional MRI data into the anatomical images and to determine clinical applications for this approach.

MATERIAL AND METHODS

In 11 patients (mean age: 2.4 years) with solid tumors, 26 diagnostic MRI examinations were performed for primary diagnosis, treatment monitoring, or as part of the surgical planning. Seven children presented with neuroblastomas, three with Wilms' tumor, and one with advanced bilateral nephroblastomatosis. The MRI data were acquired using a 1.5-T system. For post-processing, we used volume rendering software, including an evaluation of perfusion. By using color-coded parametric images and integrating functional information, perfusion could be visualized and used for interactive surgical planning. Macroscopic and microscopic sections served as the gold standard for assessing tissue viability.

RESULTS

We were able to integrate the dynamic data into the anatomical images for all patients. A good agreement was found between the results of surgical planning, including perfusion mapping, with the surgical site, subsequently produced macroscopic sections and the results of random microscopic examinations.

CONCLUSIONS

Perfusion mapping using color-coded parametric images of pediatric abdominal tumors extends the diagnostic techniques currently available. We provide first proof of the possibility of integrating functional information into 3D MR images in children. Monitoring the treatment of nephroblastoma and surgical planning for pediatric embryonal tumors represent potential applications of this technique.

Loss of anisotropy in trigeminal neuralgia revealed by diffusion tensor imaging

We studied the trigeminal nerve in seven healthy volunteers and six patients with trigeminal neuralgia using the diffusion tensor imaging derived parameter fractional anisotropy (FA). While controls did not show a difference between both sides, there was a reduction of FA in the affected nerve in three of six patients with accompanying nerve-vessel conflict and atrophy. Reversibility of abnormally low FA values was demonstrated in one patient successfully treated with microvascular decompression.

[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.

[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.

[Computer-assisted operational planning for pediatric abdominal surgery. 3D-visualized MRI with volume rendering]

Exact surgical planning is necessary for complex operations of pathological changes in anatomical structures of the pediatric abdomen. 3D visualization and computer-assisted operational planning based on CT data are being increasingly used for difficult operations in adults. To minimize radiation exposure and for better soft tissue contrast, sonography and MRI are the preferred diagnostic methods in pediatric patients. Because of manifold difficulties 3D visualization of these MRI data has not been realized so far, even though the field of embryonal malformations and tumors could benefit from this.A newly developed and modified raycasting-based powerful 3D volume rendering software (VG Studio Max 1.2) for the planning of pediatric abdominal surgery is presented. With the help of specifically developed algorithms, a useful surgical planning system is demonstrated. Thanks to the easy handling and high-quality visualization with enormous gain of information, the presented system is now an established part of routine surgical planning.

Abdominal tumours in children: 3-D visualisation and surgical planning

INTRODUCTION

Solid abdominal tumours are of special importance in the field of paediatric surgery. Because of the dangers of cumulative irradiation and improved delineation of soft parts MRI is usually employed in children for diagnostic assessment. Compiling the radiologic information for surgical planning is often difficult by conventional methods. Newly improved and efficient 3-D volume rendering software is now available for visual reconstruction of tumour anatomy utilising segmentation and other special techniques. Because the intraoperative complication rate is close to 20 % as described in the literature, optimal preoperative visualisation and planning would seem imperative.

MATERIALS AND METHODS

All children with solid abdominal tumours at Heidelberg University in the year 2002 were included in this study. MR examinations were performed with a 0.5 Tesla magnet using a standard protocol. All MR data were processed with VG Studio Max 1.1, converting the two-dimensional data into three-dimensional data.

RESULTS

This report presents 15 cases using this special technique: 7 with abdominal neuroblastoma, 6 with nephroblastoma, 1 ganglioneuroma, and 1 ovarian teratoma.

CONCLUSIONS

Our experience shows that a better understanding of the surgical anatomy, particularly regarding the surrounding organs and vasculature, can be helpful in decreasing the incidence of inadvertent intraoperative injuries to these structures.

3-D-Visualisierung in der MRT zur Operationsplanung von Wilms-Tumoren

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.

[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.

Results of the SIOP 93-01/GPOH Trial and Study for the Treatment of Patients with Unilateral Nonmetastatic Wilms Tumor

BACKGROUND

The treatment of Wilms Tumor is integrated into clinical trials since the 1970's. In contrast to the National Wilms Tumor Study Group (NWTSG) the SIOP trials and studies largely focus on the issue of preoperative therapy to facilitate surgery of a shrunken tumor and to treat metastasis as early as possible.

PATIENTS AND METHODS

In the SIOP 93-01/GPOH trial and study 1 020 patients with a newly diagnosed renal tumor were registered. 847 of them had a histological proven Wilms Tumor, of whom 637 were unilateral localized, and 173 tumors had an other histology [40 congenital mesoblastic nephroma (CMN), 51 clear cell sarcoma (CCSK), 24 rhabdoid tumor (RTK) and 58 other tumors]. Preoperative chemotherapy in benign tumors was given to 1.3 % of the patients. The main objective of the trial was the randomized question, if the postoperative two drug chemotherapy for stage I in intermediate risk or anaplasia can be reduced from conventional 3 courses to an experimental 1 course without loss of efficacy.

RESULTS

519 patients with unilateral nonmetastatic Wilms did receive preoperative chemotherapy. The histology in this group of patients was of intermediate risk in 469 (90 %) patients, 14 (3 %) tumors were low risk and 36 (7 %) high risk. The stage distribution of the tumors was stage I in 315 (61 %), stage II N- in 126 (24 %), stage II N+ in 25 (5 %) and stage III in 36 (7 %) patients. In 17 (3 %) patients the tumor stage remained unclear. Tumor volume was measured in 487 patients before and in 402 after preoperative chemotherapy. The median tumor volume did shrink from 353 to 126 ml. The amount of volume reduction depends on the histological subtype. The event free survival (EFS) after 5 years was 91 % for all patients with unilateral Wilms tumor without distant metastasis. Randomisation was done in 43.7 % for stage I patients and there was no difference in EFS for both treatment arms (90 versus 91 %). The EFS is identical for patients with stage I and II N- (0.92), as well as for stage II N+ and III (0.82). The tumor volume after chemotherapy is a prognostic factor for intermediate risk tumors with the exception of epithelial and stromal predominant tumors. These two subtypes often present as large tumors, they do not shrink during preoperative chemotherapy but they still have an excellent prognosis. On the other hand the prognosis of patients with blastemal predominant subtype after preoperative chemotherapy is worse than in any other patient group of intermediate risk tumors. There are less blastemal predominant tumors compared to primary surgery, but they are chemotherapeutic resistant selected by the preoperative chemotherapy.

CONCLUSION

Patients with unilateral Wilms tumor without metastasis have an excellent prognosis. The post-operative chemotherapy in stage I can be reduced to 4 weeks without worsening treatment outcome. The reduction of the tumor volume could be identified as a helpful marker for stratification of post-operative treatment. Post-chemotherapy blastemal predominant subtype of Wilms tumor has to be classified as high risk tumor. Focal anaplasia has a better prognosis than diffuse anaplasia and will be classified as intermediate risk tumor.

Neuroblastoma preoperatively treated as nephroblastoma: does inadequate therapy worsen the prognosis?

BACKGROUND

The current standard in the treatment of nephroblastoma is preoperative chemotherapy based on radiological appearance. After subsequent surgical removal few tumours proved histologically to be neuroblastoma. We asked whether initial chemotherapy according to nephroblastoma trials would change the prognosis for those neuroblastoma patients.

RESULTS

Out of 1603 patients registered in the German neuroblastoma trials, 29 patients (1.8 %) have preoperatively been treated according nephroblastoma protocols. Advanced stages (11 stage 3, 12 stage 4) were dominant. Diagnostic work up of those patients revealed elevation of catecholamine metabolites in only 39 % (compared to 80 % of the control patients) and mIBG uptake in only 71 % (compared to 89 % of the control patients). Elevation of NSE was observed in 92 % of patients (control group 72 %). Patients with preoperative nephroblastoma treatment were older than the patients of the control group. Risk factors like MYCN amplification or elevation of LDH were more often detected. The outcome of the patients with preoperative chemotherapy according nephroblastoma trials was worse than that of the control group, but risk group adapted survival analysis revealed no disadvantage.

CONCLUSION

The prognosis of children with neuroblastoma tumours, which have been radiologically classified as nephroblastoma, is inferior compared to the prognosis of patients without preoperative nephroblastoma therapy. The difference appears to be associated rather with more unfavourable biology than with the element "preoperative chemotherapy".

German pediatric reference data for quantitative transverse transmission ultrasound of finger phalanges

Quantitative ultrasound (QUS) of the finger phalanges is a useful tool in the assessment of disease- or age-related deterioration of bone. For studying the impact of juvenile diseases or growth disorders affecting the skeleton, a reference database for QUS parameters is needed. The aim of this study was to establish a calibrated reference database of parameters of transverse ultrasound transmission through juvenile finger phalanges. A total of 1328 children (650 females, 678 males; ages 3-17 years) were measured in Heidelberg and Kiel in order to establish a German reference database. Highly significant gender-specific correlations (p<0.0001) were found between the QUS parameters amplitude-dependent speed of sound (AD-SoS) and bone transmission time (BTT) versus age, body height and body mass index (BMI). For AD-SoS the correlation coefficients were R2 = 0.64 against age in males and R2 = 0.73 in females, R2 = 0.60 against body height in males and R2 = 0.68 in females, and R2 = 0.19 against BMI in males and R2 = 0.23 in females. For BTT the correlation coefficients were R2 = 0.74 against age in males and R2 = 0.79 in females, R2 = 0.75 against body height in males and R2 = 0.77 in females, and R2 = 0.32 against BMI in males and R2 = 0.35 in females. Age and height were the strongest determinants of QUS results. Gender-specific differences were observed in AD-SoS (significant for ages 11-14 years and for 150-170 cm body height) and in BTT (significant for ages 7 and 11-17 years and for 160-170 cm body height). Tables of QUS parameters versus age and height can serve as a basis for the evaluation of the impact of skeletal diseases or growth disorders on phalangeal QUS. Depending on the type of disease or growth disorder, measurement results can be compared with age- or height- specific reference data. In this way a simple and radiation-free assessment of juvenile skeletal disorders using quantitative ultrasound might be possible in the future.

[Acute hematogenous osteomyelitis--exclusion with Turbo-STIR sequence?]

The timely diagnosis and early initiation of antibiotic therapy determine the clinical course of an acute hematogenous osteomyelitis. Consequently, a fast and efficient MRI examination protocol is crucial. We retrospectively evaluated various MR sequences used in the examination of 8 children having osteomyelitis. The examinations were conducted using a 0.5 T MR machine. All patients had a high signal intensity of the lesion in the IR sequence with fat suppression (turbo-STIR). An acute osteomyelitis can be excluded in the absence of signal intensity increase in the turbo-STIR sequence without the necessity of having to perform additional sequences.

[Quality of ambulatory thoracic radiography in the child--a pilot study]

A quality control of outpatient paediatric chest X-rays was conducted in a sample of patients of one paediatric practice. During a period of eight months the technical image quality was analysed considering both diagnostic aspects and radiation protection. The quality of the 139 examined chest X-rays was inadequate concerning the collimation and focussing of the X-rays and the positioning of the patients. Exposure was estimated as average, sharpness was rated as good. In total 14% of the X-rays were not suitable for medical diagnosis. Image quality of the X-rays of infants (children younger than 6 years) was significantly lower compared to the total sample. Radiation protection standards were not fulfilled. As a conclusion from our results, improvements in outpatient paediatric radiography are urgently necessary. Quality control committees should pay particular attention in radiographs of infants.

Clinical impact of histologic subtypes in localized non-anaplastic nephroblastoma treated according to the trial and study SIOP-9/GPOH

BACKGROUND

Histologic subtypes of standard histology Wilms' tumor (WT) and the effect of preoperative therapy on their clinical and histologic features, deserve to be analysed in respect to outcome to find an adequate baseline for therapy.

PATIENTS AND METHODS

The German Society of Paediatric Oncology & Haematology enrolled patients from January 1989 to March 1994 for therapy according the International Society of Paediatric Oncology trial & study 9. Standardised preoperative therapy with dactinomycin and vincristine for 4-8 weeks was generally applied in patients between 0.5 and 16 years with localized renal tumors and imaging typical for WT. In 99.5% of cases representative material was sent for review to the Kiel Paediatric Tumour Registry. For prospective subtyping of 329 WT (258 after preoperative therapy, 71 with immediate surgery) modified Beckwith & Palmer criteria were used. Reduction in volume measured by imaging prior to chemotherapy and surgery was used to assess response (poor response: reduction < 40%; good response: reduction > or = 40%).

RESULTS

There were 39% of patients treated with immediate surgery and 12.4% of patients with preoperative therapy in the age group up to 12 months. The difference in age (P = 0.022) was linked with different amounts of epithelial WT (15.5% vs. 3.1%), median age: 0.58 and 0.93 years. Due to the effect of chemotherapy the amount of other WT changed: stromal 0% to 14%, mixed 45.1% to 29.4%, blastemal 39.4% to 9.3%). After preoperative therapy 37.6% of WT were predominantly regressive, 6.6% completely necrotic. Poor response was frequent in differentiated WT (86% of stromal, 75% of epithelial WT) but none relapsed. In the other WT with viable tumor left after preoperative therapy > 70% had good response, poor response was a risk factor (P = 0.0057).

CONCLUSIONS

Subtyping according modified Beckwith & Palmer can be used in WT after preoperative therapy to stratify postoperative therapy in future. A milder therapy could be tested in differentiated WT at low stages and an intensified in the others with viable tumor left and poor response, i.e., mainly blastemal WT.

[Static-dynamic MR urography. Comparison with excretory urography and scintigraphy in experimentally-induced urinary tract obstruction]

PURPOSE

To assess the diagnostic value of combined static-dynamic MR urography (MRU) for the functional-morphological evaluation of experimentally induced urinary tract obstruction.

METHODS

Static-dynamic MRU--combination study with a respiratory-triggered 3D-IR-TSE sequence and a dynamic 2D-FFE sequence after Gd-DTPA and furosemide--was obtained in comparison with 99mTc-MAG3 diuretic renal scintigraphy (DRS), excretory urography (EU) and ultrasound (US) in 29 healthy piglets and in 20 piglets with surgically induced ureteric stenosis (total of 50 postoperative examination blocks).

RESULTS

MRU allowed complete depiction of the urinary tract in all controls, in operated piglets the stenosis was always correctly identified. Quality of MRU was superior to EU in 36 of 43 comparative studies. Calculation of single kidney function from parenchymal renograms, and assessment of urinary excretion from whole-kidney renograms resulted in a highly significant agreement of MRU with DRS.

CONCLUSION

Static-dynamic MR urography allows excellent depiction of experimentally induced urinary tract obstruction, and reliable assessment of individual renal function and urinary excretion. Two advantages of the method stand out, it does not require radiation and it permits a functional-morphological correlation.

[Hypertrophic pyloric stenosis: sonographic monitoring of conservative therapy with intravenous atropine sulfate]

AIM

Ultrasound is the method of choice for the diagnosis of hypertrophic pyloric stenosis (HPS). The purpose of this study was to evaluate the usefulness of sonography in monitoring the efficacy of conservative therapy of HPS with intravenous atropine sulfate.

METHOD

21 infants with HPS under i.v. treatment with atropine sulfate were included. Pyloric sonomorphology, channel width and passage of gastric contents through the pyloric channel were monitored daily. The latter was examined with colour Doppler, too. If no clinical improvement was observed after 6-8 days, sonography and colour Doppler sonography played a crucial role in the decision whether to continue the conservative therapy or to perform pyloromyotomy.

RESULTS

Conservative treatment was effective in 13/21 infants. In 8 patients therapy was continued as sonography demonstrated the passage of gastric contents despite lack of clinical improvement. In 4 patients, due to the sonographic findings, impending surgery could be cancelled. Colour Doppler sonography proved to be extremely useful in demonstrating passage of liquid through the narrowed pyloric channel. No significant change in pyloric morphology was seen.

CONCLUSION

In HPS a conservative therapeutic approach with atropine sulfate is justified considering a success rate of 62% (13/21). During sonographic monitoring the detection of the passing of gastric content may be crucial for continuation and success of conservative therapy. In those cases colour Doppler sonography is a very useful method.

Combined static-dynamic MR urography for the simultaneous evaluation of morphology and function in urinary tract obstruction. I. Evaluation of the normal status in an animal model

OBJECTIVE

A new approach, combined static-dynamic MR urography is evaluated to determine its potential utility for the functional-morphological diagnosis of paediatric urinary tract obstruction. In this initial investigation we sought to evaluate the procedure by imaging the urinary tract of piglets.

MATERIALS AND METHODS

Twenty-nine healthy piglets were studied with MR urography (MRU), 99mTc-MAG3 diuretic renal scintigraphy (DRS), ultrasound (US) and excretory urography (EU). The functional and morphological findings were compared. For MRU we combined a respiration-triggered 3D-IR-TSE sequence and a dynamic 2D-FFE sequence after Gd-DTPA injection.

RESULTS

MRU depicted the complete urinary tract with superior image quality compared to EU. Calculation of time-intensity curves from the dynamic sequence permitted determination of single kidney function from parenchymal ROIs and urinary excretion using the whole kidney ROI. MRU and DRS showed significant agreement in the assessment of both single kidney function and urinary excretion. Disturbances of urinary drainage were generally caused by an overfilled bladder.

CONCLUSIONS

Combined static-dynamic MRU is well suited for the depiction of the complete urinary tract and for the determination of individual kidney function and urinary excretion in the piglet.

Combined static-dynamic MR urography for the simultaneous evaluation of morphology and function in urinary tract obstruction. II. Findings in experimentally induced ureteric stenosis

PURPOSE

To assess the diagnostic value of combined static-dynamic MR urography (MRU) for the functional-morphological evaluation of experimentally induced urinary tract obstruction in the piglet.

MATERIALS AND METHODS

In 20 piglets unilateral ureteric stenosis was created operatively. Post-surgery repeated comparative examinations were obtained with MRU, diuretic renal scintigraphy (DRS), excretory urography (EU) and ultrasound (US). MRU was performed as a combination study with a static 3D-IR-TSE sequence and a dynamic 2D-FFE sequence after Gd-DTPA with frusemide administration.

RESULTS

MRU allowed complete depiction of the prestenotic urinary tract and of the stenosis in all cases. In 43 comparative studies MRU was superior to EU in 36, EU to MRU in 2. When single kidney function was calculated with both MRU and DRS, results were highly correlated (r = 0.92). When urinary excretion was compared, significant agreement was achieved with concordant findings in 86% and slightly discordant results in 12%.

CONCLUSIONS

Static-dynamic MR urography permits excellent depiction of experimentally induced urinary tract obstruction in piglets and reliable assessment of individual renal function and urinary excretion. Two advantages of the method stand out--it does not require radiation and it permits functional-morphological correlation.

Adenocarcinoma of the stomach with tumor-thrombotic microangiopathy in an 11-year-old male patient

The majority of malignancies in childhood are represented by leukemias, lymphomas or other reticuloendothelial neoplasms, tumors of the central nervous system, nephroblastomas and sarcomas. Gastrointestinal tumors represent less than 5% of pediatric neoplasms and carcinomas within this subgroup have been very rarely described, especially those arising in the stomach. In this study, we report a case of an 11-year-old boy with a signet-ring carcinoma of the stomach. The patient initially presented with respiratory symptoms which were caused by massive pulmonary lymphangiosis carcinomatosa and a peculiar microangiopathy, recently addressed as pulmonary tumor thrombotic microangiopathy. To our knowledge, this constellation has not been reported so far.