Valutazione affettiva del setting odontoiatrico in età evolutiva

Lo studio si pone l'obiettivo di approfondire il tema della valutazione affettiva del setting odontoiatrico in età evolutiva indagando se possa essere modulata da fattori quali: differenze di genere, specifici quadri patologici (Displasia Ectodermica e Patologie Sistemiche Croniche) responsabili di pregresse esperienze odontoiatriche e/o ospedalizzazioni; stato affettivo del bambino, stato affettivo del genitore. Materiali e metodi Studio 1. 85 soggetti [39 (19 maschi e 20 femmine) affetti da PSC e 46 (26 maschi e 20 femmine) soggetti sani] (range di età: 5-14 anni). Sono stati somministrati: un compito di valutazione immagini con 36 immagini (12 a contenuto piacevole, 12 neutro e 12 spiacevole) dallo IAPS e 12 immagini a contenuto odontoiatrico e dei questionari (MCDASf, CFSS-DS, TAD). Studio 2. 45 soggetti (19 maschi affetti da EDs e 26 maschi sani) (range di età: 5-14 anni). Sono stati somministrati: il compito di valutazione immagini precedentemente descritto e i questionari (MCDASf, CFSS-DS, TAD). Studio 3. 104 bambini (64 maschi and 40 femmine) (range di età: 5-14 anni) e uno dei genitori (19 padri and 69 madri). Sono stati somministrati i questionari MCDASf, CFSS-DS, TAD ai bambini e FDPQ, STAI-Y1, Y2-BDI-II ai genitori. Risultati: il contesto odontoiatrico ha una caratterizzazione affettiva distinta rispetto a contesti piacevoli, spiacevoli o neutri; specifici quadri patologici (EDs e PSC) non sembrano modulare il tipo di valutazione affettiva del contesto odontoiatrico; le femmine, attribuiscono al contesto odontoiatrico una valenza significativamente più spiacevole e una maggiore attivazione emotiva rispetto ai maschi; la paura del dolore odontoiatrico del genitore ha una correlazione con l’ansia dei bambini. Conclusione: è importante che l’odontoiatra consideri che la risposta emotiva delle bambine può essere caratterizzata da vissuti di paura con tendenza a comportamenti di allontanamento e valuti se la figura genitoriale rappresenta una risorsa o un elemento disturbante nella corso della seduta stessa.

Valutazione dello spostamento tridimensionale degli impianti in giovani pazienti affetti da EDs riabilitati con overdenture implanto-supportati

Ectodermal Dysplasias syndrome (EDs) are a heterogeneous group of inherited disorders characterized by dysplasia of tissues of ectodermal origin. Complete or partial anodontia are the most frequent dental findings. Prosthetic rehabilitation is recommended from functional, esthetic, and psychological points of view. Because of the anatomical abnormalities of existing teeth and alveolar ridges, conventional prosthetic rehabilitation in young patient is often difficult. Five growing patients (age 9 to 11 years) with oligo- or anodontia were prosthetically rehabilitated. Panoramic film and Cone Bean Computerized Tomography were performed and a resin model of mandibular bone was made. Despite a remarkable multi-dimensional atrophy of the alveolar bone, the insertion of two tapered implants was possible. After a submerged healing period of 2 month, the implants were exposed and abutment connection was performed. Implants were connected with an expansion bar that permits mandibular growth and prosthetic retention. A removable prosthesis was constructed with ball attachments. Mandibular growth was followed and evaluated using the expansion guide and cephalometric radiographs. Mandibular growth in sagittal and transverse direction had no adverse effects on implant position. The expansion bar permitted the undisturbed growth of the mandible. After 4.5 years of follow-up, this study showed that Implant-supported overdenture may improve oral function, phonesis and esthetics. The mandibular rotation accompanying growth had not caused a significant problem relative to the angulation and migration of the implants. Implants can be successfully placed, restored and loaded in growing EDs patients. The cephalometric analysis supported that EDs patients show midface hypoplasia with a class III tendency, which can be avoided by early rehabilitation. Thanks to the good stability and retention of the implant-supported overdenture, patients considered the prostheses as comparable to natural teeth.

Gen knockdown der Metalloproteasen Meprin alpha 1, alpha 2 und beta im Zebrabärbling Danio rerio

Die Metalloproteasen Meprin α und β übernehmen Schlüsselfunktionen in vielen (patho-) physiologischenrnProzessen. So sind sie beteiligt an der Umstrukturierung der extrazellulären Matrix, an immunologischenrnReaktionen oder an entzündlichen Gewebserkrankungen. Die beiden Enzyme kommenrnhauptsächlich in den Bürstensaummembranen von Niere und Darm sowie in der Haut von Vertebratenrnvor. Für die Erforschung der biologischen Aktivität der Meprine wurde in dieser Arbeit der ModellorganismusrnDanio rerio verwendet, der vor allem durch die Möglichkeit der gentechnischen Manipulationrnprädestiniert ist. Im Fisch konnten drei homologe Enzyme (Meprin α1, α2 und β) nachgewiesenrnwerden. Während mRNA-Analysen eine nahezu ubiquitäre Verteilung der Meprine offenbarten,rnkonnte ich mittels spezifischer Antikörper die Expression auf Proteinebene nachweisen. WährendrnMeprin α1 und β verstärkt im Darmepithel und in der Epidermis lokalisiert sind, konnte Meprinrnα2 ausschließlich in der Lamina propria des Darms identifiziert werden.rnDer Hauptteil der vorliegenden Arbeit zielt auf die spezifische Reduzierung des Expressionslevels derrnMeprine in Embryonen des Zebrabärblings. Dies wurde durch die Mikroinjektion von sogenanntenrnMorpholinos in die Zygote erzielt. Morpholinos sind RNA-Moleküle, die spezifisch an die mRNA desrnZielproteins binden können und die Translation verhindern. Die auftretenden Effekte durch das Fehlenrnder Meprine lassen so Rückschlüsse auf ihre physiologische Funktion zu. Nach der Injektion vonrnMorpholinos gegen Meprin α1 zeigten sich lediglich leichte epidermale Deformationen. Bei Meprin βrnhingegen kam es zu einer massiven Fehlbildung von Organen im Rumpf- und Schwanzbereich. Diesesrnführte zu erheblichen Defekten; die Embryonen starben innerhalb der ersten 24 Stunden nach derrnBefruchtung. Demzufolge müssen Meprin α1 und Meprin β insbesondere an der Gewebsdifferenzierungrnbeteiligt sein. Dies korreliert mit verschiedenen Experimenten, u.a. an knockout Mäusen, ausrndenen hervorgeht, dass die Prozessierung und Aktivierung der Cytokine Interleukin-1β oder Interleukin-rn18 durch Meprin β erfolgen kann.rnDie Injektion von Meprin α2-Morpholinos erbrachte ein weiteres, eindrucksvolles Ergebnis: Das Blutgefäßsystemrnvon injizierten Embryonen war vollständig unterbrochen und es sammelten sich Erythrozytenrnim Bereich der Caudalvene an. Diese Phänotypen gleichen den knockdown-Experimenten mitrndem vascular endothelial growth factor VEGF-A, dem entscheidenden Wachstumsfaktor in der Angiogenesern(Blutgefäßbildung). Eine Inkubation des humanen VEGF-A mit (humanem) rekombinantemrnMeprin α bzw. β führte zu einer differenzierten Prozessierung des Moleküls. Diese Ergebnisse legenrnnahe, dass Meprin α pro-angiogenetisch wirkt, indem es VEGF-A prozessiert und damit die Gefäßbildungrnaktiviert. Aus den Daten dieser Arbeit wird die hohe Signifikanz der Meprine für die Proliferationrnund Differenzierung spezieller Gewebe deutlich, welche somit eine wichtige Grundlage für Studienrnan höheren Vertebraten darstellt.

Flow Field–Flow Fractionation for size analysis and characterization of nanoparticles for applications in Life Sciences

Nanotechnologies are rapidly expanding because of the opportunities that the new materials offer in many areas such as the manufacturing industry, food production, processing and preservation, and in the pharmaceutical and cosmetic industry. Size distribution of the nanoparticles determines their properties and is a fundamental parameter that needs to be monitored from the small-scale synthesis up to the bulk production and quality control of nanotech products on the market. A consequence of the increasing number of applications of nanomaterial is that the EU regulatory authorities are introducing the obligation for companies that make use of nanomaterials to acquire analytical platforms for the assessment of the size parameters of the nanomaterials. In this work, Asymmetrical Flow Field-Flow Fractionation (AF4) and Hollow Fiber F4 (HF5), hyphenated with Multiangle Light Scattering (MALS) are presented as tools for a deep functional characterization of nanoparticles. In particular, it is demonstrated the applicability of AF4-MALS for the characterization of liposomes in a wide series of mediums. Afterwards the technique is used to explore the functional features of a liposomal drug vector in terms of its biological and physical interaction with blood serum components: a comprehensive approach to understand the behavior of lipid vesicles in terms of drug release and fusion/interaction with other biological species is described, together with weaknesses and strength of the method. Afterwards the size characterization, size stability, and conjugation of azidothymidine drug molecules with a new generation of metastable drug vectors, the Metal Organic Frameworks, is discussed. Lastly, it is shown the applicability of HF5-ICP-MS for the rapid screening of samples of relevant nanorisk: rather than a deep and comprehensive characterization it this time shown a quick and smart methodology that within few steps provides qualitative information on the content of metallic nanoparticles in tattoo ink samples.

Generierung und Charakterisierung von in-vitro- und in- vivo-Modellsystemen zur Untersuchung des Skelettsystems

Die Entstehung und Aufrechterhaltung von Knorpel- und Knochengewebe wird durch eine Vielzahl von hemmenden oder fördernden Faktoren hoch komplex reguliert, wobei die dabei involvierten physiologischen Prozesse bisher nur teilweise verstanden werden. Auch die Ursachen sowohl degenerativer Erkrankungen, aber auch durch Mutationen im FGFR3-Gen verursachter Chondrodysplasien sind in ihrer Ätiopathogenese noch nicht vollständig erforscht. In dieser Arbeit wurden verschiedene experimentelle Ansätze verfolgt, die zur weiteren Aufklärung der Pathophysiologie zweier unterschiedlicher Skeletterkrankungen beitragen sollten.rnEin relevantes Charakteristikum der degenerativen Gelenkserkrankung Osteoarthrose ist der Verlust an Aggrekan, hauptverantwortlich verursacht durch die Aggrekanase ADAMTS5. Es wurde ein Tiermodell generiert, bei dem gezielt mittels des Tet-ON-Systems die Aggrekanase mAdamts-5 überexprimiert werden kann. Nach Konstruktherstellung und Generierung als auch Charakterisierung des in vitro-Modells wurde das Tiermodell hergestellt, um die Folgen der Überexpression im Hinblick auf einen verstärkten Aggrekanabbau im Knorpel der Mäuse zu analysieren. Nach initialer Charakterisierung auf Induzierbarkeit zeigte eine Gründerlinie eine induzierbare transgene mAdamts5-Expression. Die Überprüfung auf Knorpelspezifität zeigte, sowohl embryonal als auch im adulten Tier, dass sich der verwendete, zusammengesetzte Kollagen-Typ II Promotor wie der endogene verhielt und somit funktional war. Nach Doxyzyklininduktion wurde bei der optimalen Dosis von 1 mg/ml im Vergleich zum induzierten Wildtyp-Tier eine 15%ige Abnahme des Gesamt-Glykosamino-glykan(GAG)-Gehaltes und eine um 120% erhöhte GAG-Abgabe ins Medium detektiert, was eine verstärkte Spaltung von Aggrekan bedeutete. Die transgene Aggrekanase wurde überexprimiert und spaltete verstärkt Aggrekan. Da aufgrund der histologischen Untersuchungen jedoch keine Knorpelerosionen feststellbar waren, konnte im Umkehrschluss gefolgert werden, dass der Knorpel einen Verlust an Glykosaminoglykanen bis zu einer gewissen Grenze tolerieren kann. Mit dem generierten und charakterisierten Tiermodell konnte mit dem Verlust an GAG eine Osteoarthrose-ähnliche Situation simuliert werden, insbesondere im Hinblick auf frühe Stadien der Erkrankung, bei denen noch keine makroskopisch eindeutig sichtbare Knorpelerosionen vorliegen. rnIm zweiten Teil der Arbeit wurden Zellkulturexperimente zur weiteren Aufklärung FGFR3-regulierter Prozesse durchgeführt. Nach Generierung und Verifizierung der stabilen Zelllinien, die mittels des Tet-ON-Systems das FGFR3-Gen mit jeweils einer Chondrodysplasie-assoziierten Mutation (Achondroplasie-Mutation G380R, Thanatophore Dysplasie Typ II-Mutation K650E) induzierbar überexprimieren, wurden die Auswirkungen der zwei verschiedenen Mutationen anhand bereits beschriebener Signalwege untersucht. Über die Rekrutierung des ERK-Signalweges konnte bei beiden Zelllinien die Funktionalität nachgewiesen werden, wobei die Zelllinie mit der einen schwereren Phänotyp beim Menschen verursachenden TDII-Mutation eine stärkere Aktivierung zeigte. Bei der Aktivierung von STAT1 wies nur die TDII-Zelllinie eine Phosphorylierung auf, nicht jedoch die ACH-Zelllinie; dies deckte sich mit bereits publizierten Untersuchungen. Beide Kaskaden zeigten eine unterschiedliche Signalantwort aufgrund der verschiedenen Mutationen. Des Weiteren konnte eine unterschiedliche MMP13-Zielgenexpression nachgewiesen werden, wobei lediglich die ACH-Zelllinie eine erhöhte MMP13-Expression (6-fach) zeigte. Zur Identifizierung neuer involvierter FGFR3-Zielgene wurde die differentielle Genexpression der TDII-Zelllinie im Vergleich induziert/nicht induziert mittels Microarray-Hybridisierung untersucht. Als interessantes Zielgen fiel STC1 auf, welches ebenfalls eine Rolle in der Chondrogenese spielt und bislang nicht mit FGFR3 in Verbindung gebracht wurde. Es konnte jedoch nur auf RNA-Ebene eine Regulation nachgewiesen werden. Nachfolgend durchgeführte transiente Experimente zeigten, dass die Wildtyp-Variante von FGFR3 möglicherweise eine Funktion in der Sekretion des Proteins STC1 hat und dass durch die beiden eingefügten Mutationen (ACH, TDII) diese aufgehoben ist. Der Einfluss von FGFR3 auf die Sekretion von STC1 stellt ein neues Ergebnis dar, insbesondere auch die Auswirkungen der beiden für die unterschiedlichen Krankheitsbilder stehenden Mutationen. Welche Relevanz allerdings die STC1-Sekretion im Rahmen FGFR3-assoziierter Erkrankungen hat, kann nicht eindeutig beurteilt werden. Weitere Faktoren aus dem hoch komplexen Zusammenspiel während der Knorpel/Knochenentwicklung müssen untersucht werden, um eine definitive Einordnung zu ermöglichen.

Impact of chorioamnionitis and preeclampsia on neurodevelopmental outcome in preterm infants below 32 weeks gestational age

ABSTRACT Aim: Intrauterine conditions may interfere with fetal brain development. We compared the neurodevelopmental outcome between infants <32 weeks gestational age after maternal preeclampsia or chorioamnionitis and controls. Methods: Case-control study on infants with maternal preeclampsia, chorioamnionitis and controls (each n = 33) matched for gestational age. Neurodevelopment at two years was assessed with the Bayley Scales of Infant Development II. Results: Ninety-nine infants were included with a median gestational age of 29 weeks (range 25-32). Median mental developmental index (MDI) was 96 in the control, 90 in the chorioamnionitis and 86 in the preeclampsia group. Preeclampsia infants had a lower MDI compared with the control group (univariate p = 0.021, multivariate p = 0.183) and with the chorioamnionitis group (univariate p = 0.242; multivariate p = 0.027). Median psychomotor index was 80.5 in the control, 80 in the preeclampsia and 85 in the chorioamnionitis group, and was not different between these three groups (p > 0.05). Chorioamnionitis or preeclampsia exposure was not associated with major neurodevelopmental impairments (cerebral palsy, MDI<70, PDI<70). Conclusion: The results of this preliminary study suggest that preeclampsia and chorioamnionitis play a relatively minor role among risk factors for adverse neurodevelopment outcome. Postnatal factors such as ventilation and bronchopulmonary dysplasia may have a greater impact on neurodevelopmental outcome.

Osteochondritis dissecans of the femoral head

Seven patients with symptomatic osteochondritic lesions of the femoral head are presented. All were male with a mean age of 26 years (16 - 33 years). Two distinct morphologic appearances of the hip joint could be identified. Five patients presented with a coxa valga deformity, four of whom had signs of epiphyseal dysplasia. There were 2 patients whose hips appeared normal apart from the osteochondrontic lesions. In both cases an additional acetabular rim lesion due to a reproducible femoro-acetabular impingement was diagnosed at arthrotomy. This may have acted as the underlying cause of osteochondritis dissecans in these cases. All 7 patients underwent surgical treatment. An intertrochanteric osteotomy (I.O.) alone was performed in 2 patients. Follow-up of these patients at 6.5 and 8.5 years after surgery revealed that the osteochondritic lesions had not healed and one individual remained symptomatic. In the remaining 5 patients, treatment consisted of femoral head dislocation and screw fixation of the osteochondritic lesion. This was combined with an I.O. in two of these patients for coxa valga and osteoplasty of a broad femoral neck in 2 other patients. All lesions had healed at an average follow-up of 4.3 years (2 - 8.5 years). Three patients were asymptomatic and 2 patients had minor residual pain. No progressive osteoarthritic changes or signs of avascular necrosis of the femoral head were observed.

Algorithm for femoral and periacetabular osteotomies in complex hip deformities

Residual acetabular dysplasia of the hip in most patients can be corrected by periacetabular osteotomy. However, some patients have intraarticular abnormalities causing insufficient coverage, containment or congruency after periacetabular osteotomy, or extraarticular abnormalities that limit either acetabular correction or hip motion. For these patients, we believe an additional proximal femoral osteotomy can improve coverage, containment, congruency and/or motion.

The pharmacokinetics and safety of porfimer after repeated administration 30-45 days apart to patients undergoing photodynamic therapy

Porfimer is an intravenous (i.v.) injectable photosensitizing agent used in the photodynamic treatment of tumours and of high-grade dysplasia in Barrett's oesophagus.

Fatal pulmonary embolism in a premature neonate after twin-to-twin transfusion syndrome

Thrombotic events are being increasingly recognized during the neonatal period. An infant girl was born at 29 weeks' gestation after a pregnancy complicated by twin-to-twin transfusion syndrome. After an initial uncomplicated clinical course, her oxygen requirement increased, which was interpreted as an early sign of bronchopulmonary dysplasia. At 3 weeks of age, she suddenly collapsed and died of severe pulmonary hypertension. At autopsy, multiple pulmonary artery emboli and several older renal vein thromboses were found. Results of genetic analyses of the infant and her family were negative for thrombophilia. Although embolism represents a frequent emergency in adults, fatal pulmonary embolism has never, to our knowledge, been described for premature infants. This case suggests that thrombotic events are underdiagnosed and that additional studies are needed to define infants at risk and optimal treatment strategies.

Meningocerebral angiodysplasia with metanephric induction failure: Broadening the spectrum of an emerging maldevelopmental syndrome

The uncommon simultaneous occurrence of an exuberant, angioma-like proliferation of superficial cerebral microvessels along with absence of the kidneys has been proposed to constitute a syndromic complex for which the term "meningocerebral angiodysplasia (or angiomatosis) with renal agenesis" (MCA-RA) is being descriptively used. We observed this constellation in one of a pair of dichorionic male twins following postpartal death in the 38th week of pregnancy. General autopsy revealed rudimentary metanephric anlagen made up of few residual glomeruli, cysts lined by flattened tubular epithelium, and islands of cartilage - corresponding to renal aplastic dysplasia. Largely inconspicuous with respect to its gyral pattern, as well as the configuration of the ventricular system, the brain microscopically showed extensive replacement of the cortex by a lattice of proliferating capillaries with necrosis of the intervening parenchyma. Minute foci of calcified necrosis were scattered in the deep subcortical white matter as well, while the ventricular ependyma and the subventricular germ cell layer remained remarkably intact. The cerebellum and brain stem appeared unaffected as well. Karyotyping of skin fibroblasts indicated a normal chromosome set of 46XY without gross structural anomalies. We interpret these findings as ones apt to being reasonably accommodated within the spectrum of MCA-RA. Although exceedingly rare, accurate identification of individual cases of MCA-RA is relevant both to differential diagnosis from its prognostically different look-alike "proliferative vasculopathy and hydranencephaly-hydrocephaly" (PVHH), and to refine the nosology of unconventional pediatric vascular malformations, for which the rather nonspecific label "angiodysgenetic necrotizing encephalopathy" is still commonly used.

Respiratory symptoms in preterm infants: burden of disease in the first year of life

Objective While respiratory symptoms in the first year of life are relatively well described for term infants, data for preterm infants are scarce. We aimed to describe the burden of respiratory disease in a group of preterm infants with and without bronchopulmonary dysplasia (BPD) and to assess the association of respiratory symptoms with perinatal, genetic and environmental risk factors. Methods Single centre birth cohort study: prospective recording of perinatal risk factors and retrospective assessment of respiratory symptoms during the first year of life by standardised questionnaires. Main outcome measures: Cough and wheeze (common symptoms), re-hospitalisation and need for inhalation therapy (severe outcomes). Patients: 126 preterms (median gestational age 28.7 weeks; 78 with, 48 without BPD) hospitalised at the University Children's Hospital of Bern, Switzerland 1999-2006. Results Cough occurred in 80%, wheeze in 44%, rehospitalisation in 25% and long term inhalation therapy in wheezers in 13% of the preterm infants. Using logistic regression, the main risk factor for common symptoms was frequent contact with other children. Severe outcomes were associated with maximal peak inspiratory pressure, arterial cord blood pH, APGAR and CRIB-Score. Conclusions Cough in preterm infants is as common as in term infants, whereas wheeze, inhalation therapy and re-hospitalisations occur more often. Severe outcomes are associated with perinatal risk factors. Preterm infants who did not qualify for BPD according to latest guidelines also showed a significant burden of respiratory disease in the first year of life.

Bernese periacetabular osteotomy in males: is there an increased risk of femoroacetabular impingement (FAI) after Bernese periacetabular osteotomy?

The Bernese periacetabular osteotomy (PAO) is a popular option for treating symptomatic acetabular dysplasia. We noted symptomatic impingement after PAO in several male patients.

Appendiceal mucocele in an elderly patient: how much surgery?

Appendiceal mucoceles are rare cystic lesions with an incidence of 0.3-0.7% of all appendectomies. They are divided into four subgroups according to their histology. Even though the symptoms may vary - depending on the level of complication - from right lower quadrant pain, signs of intussusception, gastrointestinal bleeding to an acute abdomen with sepsis, most mucoceles are asymptomatic and found incidentally. We present the case of a 70-year-old patient with an incidentally found appendiceal mucocele. He was seen at the hospital for backache. The CT scan showed a vertebral fracture and a 7-cm appendiceal mass. A preoperative colonoscopy displayed several synchronous adenomas in the transverse and left colon with high-grade dysplasia. In order to lower the cancer risk of this patient, we performed a subtotal colectomy. The appendiceal mass showed no histopathological evidence of malignancy and no sign of perforation. The follow-up was therefore limited to 2 months. In this case, appendectomy would have been sufficient to treat the mucocele alone. The synchronous high-grade dysplastic adenomas were detected in the preoperative colonoscopy and determined the therapeutic approach. Generally, in the presence of positive lymph nodes, a right colectomy is the treatment of choice. In the histological presence of mucinous peritoneal carcinomatosis, cytoreductive surgery with hyperthermic intraperitoneal chemotherapy is indicated. In conclusion, mucoceles of the appendix are detected with high sensitivity by CT scan. If there is no evidence of synchronous tumor preoperatively and no peritoneal spillage, invasion or positive sentinel lymph nodes during surgery, a mucocele is adequately treated by appendectomy.

Interaction of the receptor FGFRL1 with the negative regulator Spred1

FGFRL1 is a member of the fibroblast growth factor receptor family. It plays an essential role during branching morphogenesis of the metanephric kidneys, as mice with a targeted deletion of the Fgfrl1 gene show severe kidney dysplasia. Here we used the yeast two-hybrid system to demonstrate that FGFRL1 binds with its C-terminal, histidine-rich domain to Spred1 and to other proteins of the Sprouty/Spred family. Members of this family are known to act as negative regulators of the Ras/Raf/Erk signaling pathway. Truncation experiments further showed that FGFRL1 interacts with the SPR domain of Spred1, a domain that is shared by all members of the Sprouty/Spred family. The interaction could be verified by coprecipitation of the interaction partners from solution and by codistribution at the cell membrane of COS1 and HEK293 cells. Interestingly, Spred1 increased the retention time of FGFRL1 at the plasma membrane where the receptor might interact with ligands. FGFRL1 and members of the Sprouty/Spred family belong to the FGF synexpression group, which also includes FGF3, FGF8, Sef and Isthmin. It is conceivable that FGFRL1, Sef and some Sprouty/Spred proteins work in concert to control growth factor signaling during branching morphogenesis of the kidneys and other organs.