Synthese von Cyclooxygenase-2-Inhibitoren als Grundlage für die funktionelle Charakterisierung der COX-2-Expression mittels PET

Eine erhöhte COX-2-Expression wird bei Krankheiten wie rheumatoider Arthritis aber auch Parkinson, Alzheimer und Krebs beobachtet. Die nichtinvasive Visualisierung und Quantifizierung der COX 2-Expression in vivo mittels Positronen-Emissions-Tomographie (PET) könnte wertvolle Beiträge zur Diagnose dieser Krankheiten liefern. Zur Nutzung der PET-Technik werden geeignete COX-2-adressierende Radiotracer benötigt, deren Entwicklung auch die Identifizierung neuer, der Radiomarkierung zugänglicher COX-2-Inhibitoren als Leitstrukturen voraussetzt. Ziel dieser Arbeit war die Synthese von selektiven, der Radiomarkierung zugänglichen COX 2-Inhibitoren und deren In-vitro-Evaluierung, um Verbindungen zu identifizieren, die für eine weitere Entwicklung zu COX-2-adressierenden Radiotracern geeignet sind. Im Rahmen dieser Arbeit wurden ausgehend von literaturbekannten COX-2-Inhibitoren zwei grundlegende Strategien verfolgt: die Derivatisierung an der Peripherie sowie der Austausch von Strukturelementen im Grundgerüst der COX-2-selektiven Inhibitoren. In dieser Arbeit wird zum einen die Synthese der Zielverbindungen (Diphenyl-substituierte Indol-, Pyrazolo[1,5-b]pyridazin-, 1,2-Dihydropyrrolo[3,2,1-hi]indol- und Pyrrolo[3,2,1-hi]indol-Derivate sowie 2-Carbaboranyl-substituierte Indol-Derivate) und deren strukturanalytische Charakterisierung vorgestellt. Es konnte die McMurry-Cyclisierung als neuer Zugang für die Synthese von Carbaboranyl-substituierten Verbindungen und 1,2-Dihydropyrrolo[3,2,1-hi]indol-Derivaten sowie die Dehydrogenierung mittels DDQ als neue Variante zur Synthese von Pyrrolo[3,2,1-hi]indol-Derivaten etabliert werden. Durch Röntgeneinkristallstrukturanalyse wurde die Molekülstruktur von sechs Zwischenverbindungen und neun Zielverbindungen aufgeklärt. Zum anderen erfolgte die Charakterisierung der Verbindungen in vitro, wobei die COX-inhibitorischen Eigenschaften mit einem Fluoreszenz-basierten, einem Enzymimmunoassay (EIA)-basierten und einem [14C]Arachidonsäure-basierten COX-Assay bestimmt und zudem viele Verbindungen hinsichtlich ihrer Redoxeigenschaften untersucht wurden. Im Besonderen die hergestellten Indol-Derivate besitzen antioxidative Eigenschaften, die bei der Untersuchung der COX inhibitorischen Eigenschaften beachtet werden müssen. Die Derivatisierung an der Peripherie der bekannten Inhibitoren führte zur Identifizierung von zwei Aminosulfonyl-substituierten Indol-Derivaten und einem Fluorethoxy-substituierten Pyrazolo[1,5 b]pyridazin-Derivat, die grundsätzlich geeignete Kandidaten für eine weitere Entwicklung zum Radiotracer darstellen. Das Fluorethoxy-substituierte Pyrazolo[1,5 b]pyridazin-Derivat wurde im Rahmen dieser Arbeit mit Fluor-18 markiert und die initiale Charakterisierung des Radiotracers in vitro durchgeführt. Der Austausch von Strukturelementen im Grundgerüst der literaturbekannten COX-2-Inhibitoren mit voluminöseren Gruppen führte zum einen bei Austausch eines Phenylrings gegen einen Carbaboranyl-Cluster zum Verlust der COX-inhibitorischen Eigenschaften, was eine weitere Entwicklung dieser Verbindungen zum Radiotracer ausschließt. Zum anderen wurde ausgehend von 2,3-Diphenyl-1H-indol-Derivaten die bicyclische auf eine tricyclische Kernstruktur vergrößert. Dies lieferte hoch affine und selektive COX-2-Inhibitoren. Unter den hergestellten Verbindungen wurden ein 1,2-Dihydropyrrolo[3,2,1-hi]indol- und drei Pyrrolo[3,2,1-hi]indol-Derivate als vielversprechende Kandidaten für die weitere Entwicklung zum Radiotracer identifiziert

Psychosocial impact of living-related kidney transplantation on donors and partners

Living-related kidney transplantation (LRKT) is an option for children with end-stage renal failure. In addition to medical concerns, there is uncertainty about the psychological impact of living-related donation on parent donors and families. A survey was conducted on the decision making process and medical and psychosocial consequences of LRKT. Between 1992 and 1999, 20 parents donated a kidney for their child. A questionnaire including 24 items was sent to parent donors and their partners. Nineteen parents and partners responded; the median time after LRKT was 3years. Donors and partners reported an independent decision making process with no significant influence of partners, relatives, or hospital staff. Partners were more concerned about medical problems than donors themselves (P <0.02). Donors and partners cited no medical problems except sustained pain. Both reported an improved personal relationship towards the transplanted child. Donors and partners also cited an improved personal relationship. The vast majority (18/19) of couples still supported the decision for organ donation. In conclusion, there was a high degree of satisfaction with the decision making process in LRKT. The great majority of donors and partners did not report negative medical or psychological consequences. The relationship between donor, partner, and recipient child improved after LRK

Transplantation of infant en bloc kidneys into paediatric recipients

En bloc renal transplantation (EBT) from infant donors is an option for children with end-stage renal failure. Owing to potential complications, EBT is not performed in all paediatric nephrology centres. We evaluated the perioperative and long-term course of five children undergoing EBT. Primary diagnosis was atypical (diarrhoea-negative) haemolytic uraemic syndrome (n=2), interstitial nephropathy (two siblings) and branchio-oto-renal syndrome (n=1). Recipient and donor ages ranged between 5.9 and 11.1 years and 0.3 and 2.5 years, respectively. Follow-up time after EBT was 2.1-13.2 years. Perioperative complications included (1) a renal artery thrombosis, with immediate intraoperative reconstruction and primary non-functioning of the graft, with recovery after 10 days, and (2) a vesico-ureteric obstruction, successfully managed with temporary insertion of a JJ-catheter. All grafts had good long-term function. Absolute glomerular filtration rate (GFR; millilitres/minute) increased in all patients, whereas relative GFR (millilitres/minute per 1.73m2 body surface area) remained stable during the follow-up period in all but one. Kidney size increased significantly, with maximal growth during the first year after EBT; magnetic resonance imaging (MRI) showed normal structure and vasculature. EBT is a safe and effective option for young children with end-stage renal failure. Absolute GFR and graft size increase and adapt to the children's growing body mas

Selective late steroid withdrawal after renal transplantation

Steroid withdrawal (SW) after paediatric renal transplantation (RTPL) is controversial. Selective late SW has been performed in our unit since 1995. The safety and effects of SW were analysed retrospectively in 47 patients undergoing RTPL between 1995 and 2004. Initial immunosuppression consisted of cyclosporine A, azathioprine or mycophenolate mofetil and steroids. Criteria for SW were: (1) stable renal function, (2) time interval after RTPL ≥ 1year, (3) no rejection or time interval after last rejection ≥ 1year and (4) good compliance. SW was performed in 30 patients at an age of 13.5years (range 4.5-18.5) and 2.2years (range 1-6.6) after RTPL. After SW, one patient experienced a steroid-sensitive rejection. Follow-up after SW (1.3year; range 0.25-7.5) showed maintained renal function: glomerular filtration rate at SW and currently was 82 (65-128) and 82 (42-115) ml/min per 1.73m2, respectively. The number of patients on antihypertensive treatment did not significantly change (at SW: n = 15; currently: n = 11). Height and body mass index (BMI) remained stable: Median standard deviation score (SDS) for height/BMI at SW and currently was −1.1/0.2 and −0.8/0.1, respectively. Selective late SW was safe regarding renal function and had no significant effect on blood pressure and growt

Outcome after renal transplantation. Part II: Quality of life and psychosocial adjustment

Knowledge of health-related quality of life (QOL) and psychosocial adjustment (PA) in children after renal transplantation (RTPL) is limited. QOL and PA were evaluated by standardized tests in patients after RTPL. Thirty-seven children of median age 14.5years (range 6.5-17years) were investigated a mean 4.5years (range 0.5-12.8years) after RTPL. Child- and parent-rated QOL was evaluated with the Child Quality of life Questionnaire of The Netherlands Organization for Applied Scientific Research Academical Medical Centre (TNO-AZL). PA was assessed by the Child Behaviour Checklist (CBCL) providing parental reports of a child's behaviour. In patients' self-ratings, the QOL dimension physical complaints (P < 0.0005) scored significantly better than that of healthy controls, whereas the dimension positive emotional functioning was impaired (P = 0.02). Parents rated motor functioning (P = 0.002), autonomy (P = 0.01), cognition (P = 0.04) and positive emotions (P < 0.0005) as significantly impaired. Parents also assessed PA significantly (P = 0.02) impaired with regard to internalizing behaviour. Dialysis duration, young age at RTPL, living-related donation, steroid treatment, adverse family relationships and maternal distress had a significantly negative impact on QOL and PA (P < 0.05). Patients rated QOL higher than did healthy controls. Parents evaluated their children's QOL and PA more pessimistically than did the patients themselves. Both illness-related variables and family environment played an important rol

Outcome after renal transplantation. Part I: Intellectual and motor performance

Comprehensive information on neurodevelopmental outcome in children and adolescents with chronic kidney disease is still limited. Intellectual performance (IP) and motor performance (MP) were systematically assessed in 27 patients at a median age of 14.1years (range 6.5-17) and 6years (range 0.5-12.7) after renal transplantation (RTPL). IP was analyzed with the Wechsler Intelligence Scale for Children-III (WISC-III) in 25 patients and by the Kaufman Assessment Battery for Children in two patients. MP was evaluated by the Zurich Neuromotor Assessment. Median full- scale intelligent quotient (FSIQ) was 97 (range 49-133). Twenty-one patients had an FSIQ ≥ 85 (i.e. ≥ mean-1 standard deviation). The five patients with neurological comorbidity had a median FSIQ of 81 (range 49-101). Verbal IQ (VIQ) (median 104; range 50-146) was significantly (p < 0.01) higher than performance IQ (PIQ) (median 88; range 48-117). The PIQ was significantly lower compared with controls (p < 0.007), and patients scored significantly lower compared with controls in five of 11 subtests of the Wechsler Scale. All MP tasks were significantly (p < 0.01) lower than in controls, and also in children without neurological comorbidity. Socioeconomic status was significantly correlated with FSIQ (p = 0.03). IP after RTPL was within the normal range for the majority of children. PIQ was lower compared with VIQ, and MP was significantly affected in all children after RTP

Intellectual and motor performance, quality of life and psychosocial adjustment in children with cystinosis

Cystinosis is a rare multisystemic progressive disorder mandating lifelong medical treatment. Knowledge on the intellectual and motor functioning, health-related quality of life and psychosocial adjustment in children with cystinosis is limited. We have investigated nine patients (four after renal transplantation) at a median age of 9.7years (range 5.3-19.9years). Intellectual performance (IP) was analysed with the Wechsler Intelligence Scale for Children-III (seven children) and the Kaufman Assessment Battery for Children (two children). Motor performance (MP) was evaluated using the Zurich Neuromotor Assessment Test, and quality of life (QOL) was studied by means of the Netherlands Organization for Applied Scientific Research Academical Medical Center Child Quality of Life Questionnaire. Psychosocial adjustment was assessed by the Child Behavior Checklist. The overall intelligence quotient (IQ) of our patient cohort (median 92, range 71-105) was significantly lower than that of the healthy controls (p = 0.04), with two patients having an IQ < 85. Verbal IQ (93, range 76-118) was significantly higher than performance IQ (90, range 68-97; p = 0.03). The MP was significantly below the norm for pure motor, pegboard and static balance, as well as for movement quality. The patients' QOL was normal for six of seven dimensions (exception being positive emotions), whereas parents reported significant impairment in positive emotions, autonomy, social and cognitive functions. Significant disturbance was noted in terms of psychosocial adjustment. Based on the results from our small patient cohort, we conclude that intellectual and motor performance, health-related QOL and psychosocial adjustment are significantly impaired in children and adolescents with cystinosi

Engineering Java 7's Dual Pivot Quicksort Using MaLiJAn

Wild S, Nebel M, Reitzig R, Laube U. Engineering Java 7's Dual Pivot Quicksort Using MaLiJan. In: Proceedings of the 15th Meeting on Algorithm Engineering and Experiments, ALENEX 2013, New Orleans, Louisiana, USA, January 7, 2013. Philadelphia, PA: Society for Industrial and Applied Mathematics; 2013: 55--69

A very mild phenotype in six individuals of a three-generation family with the novel HRAS variant c.176C > G p.(Ala59Gly): Emergence of a new HRAS-related RASopathy distinct from Costello syndrome

Costello syndrome is a clinically recognizable, severe neurodevelopmental disorder caused by heterozygous activating variants in HRAS. The vast majority of affected patients share recurring variants affecting HRAS codons 12 and 13 and a relatively uniform phenotype. Here, we report the unique and attenuated phenotype of six individuals of an extended family affected by the HRAS variant c.176C>T p.(Ala59Gly), which, to our knowledge, has never been reported as a germline variant in patients so far. HRAS Alanine 59 has been previously functionally investigated as an oncogenic hotspot and the p.Ala59Gly substitution was shown to impair intrinsic GTP hydrolysis. All six individuals we report share a phenotype of ectodermal anomalies and mild features suggestive of a RASopathy, reminiscent of patients with Noonan syndrome-like disorder with loose anagen hair. All six are of normal intelligence, none have a history of failure to thrive or malignancy, and they have no known cardiac or neurologic pathologies. Our report adds to the previous reports of patients with rare variants affecting amino acids located in the SWITCH II/G3 region of HRAS and suggests a consistent, attenuated phenotype distinct from classical Costello syndrome. We propose the definition of a new distinct HRAS-related RASopathy for patients carrying HRAS variants affecting codons 58, 59, 60