Inibizione selettiva del gene MYCN mediante PNA (acidi peptido nucleici) anti-gene nel rabdomiosarcoma umano

MYCN oncogene amplification/expression is a feature of many childhood tumors, and some adult tumors, and it is associated with poor prognosis. While MYC expression is ubiquitary, MYCN has a restricted expression after birth and it is an ideal target for an effective therapy. PNAs belong to the latest class of nucleic acid-based therapeutics, and they can bind chromosomal DNA and block gene transcription (anti-gene activity). We have developed an anti-gene PNA that targets specifically the MYCN gene to block its transcription. We report for the first time MYCN targeted inhibition in Rhabdomyosarcoma (RMS) by the anti-MYCN-PNA in RMS cell lines (four ARMS and four ERMS) and in a xenograft RMS mouse model. Rhabdomyosarcoma is the most common pediatric soft-tissue sarcoma, comprising two main subgroups [Alveolar (ARMS) and Embryonal (ERMS)]. ARMS is associated with a poorer prognosis. MYCN amplification is a feature of both the ERMS and ARMS, but the MYCN amplification and expression levels shows a significant correlation and are greater in ARMS, in which they are associated with adverse outcome. We found that MYCN mRNA and protein levels were higher in the four ARMS (RH30, RH4, RH28 and RMZ-RC2) than in the four ERMS (RH36, SMS-CTR, CCA and RD) cell lines. The potent inhibition of MYCN transcription was highly specific, it did not affect the MYC expression, it was followed by cell-growth inhibition in the RMS cell lines which correlated with the MYCN expression rate, and it led to complete cell-growth inhibition in ARMS cells. We used a mutated- PNA as control. MYCN silencing induced apoptosis. Global gene expression analysis (Affymetrix microarrays) in ARMS cells treated with the anti-MYCN-PNA revealed genes specifically induced or repressed, with both genes previously described as targets of N-myc or Myc, and new genes undescribed as targets of N-myc or Myc (mainly involved in cell cycle, apoptosis, cell motility, metastasis, angiogenesis and muscle development). The changes in the expression of the most relevant genes were confirmed by Real-Time PCR and western blot, and their expression after the MYCN silencing was evaluated in the other RMS cell lines. The in vivo study, using an ARMS xenograft murine model evaluated by micro-PET, showed a complete elimination of the metabolic tumor signal in most of the cases (70%) after anti-MYCN-PNA treatment (without toxicity), whereas treatment with the mutated-PNA had no effect. Our results strongly support the development of MYCN anti-gene therapy for the treatment of RMS, particularly for poor prognosis ARMS, and of other MYCN-expressing tumors.

Rag2-/-;gammac-/- immunodeficient mice, a new preclinical model to study antitumor approaches

Animal models have been relevant to study the molecular mechanisms of cancer and to develop new antitumor agents. Anyway, the huge divergence in mouse and human evolution made difficult the translation of the gained achievements in preclinical mouse based studies. The generation of clinically relevant murine models requires their humanization both concerning the creation of transgenic models and the generation of humanized mice in which to engraft a functional human immune system, and reproduce the physiological effects and molecular mechanisms of growth and metastasization of human tumors. In particular, the availability of genotypically stable immunodepressed mice able to accept tumor injection and allow human tumor growth and metastasization would be important to develop anti-tumor and anti-metastatic strategies. Recently, Rag2-/-;gammac-/- mice, double knockout for genes involved in lymphocyte differentiation, had been developed (CIEA, Central Institute for Experimental Animals, Kawasaki, Japan). Studies of human sarcoma metastasization in Rag2-/-; gammac-/- mice (lacking B, T and NK functionality) revealed their high metastatic efficiency and allowed the expression of human metastatic phenotypes not detectable in the conventionally used nude murine model. In vitro analysis to investigate the molecular mechanisms involved in the specific pattern of human sarcomas metastasization revealed the importance of liver-produced growth and motility factors, in particular the insulin-like growth factors (IGFs). The involvement of this growth factor was then demonstrated in vivo through inhibition of IGF signalling pathway. Due to the high growth and metastatic propensity of tumor cells, Rag2-/-;gammac-/- mice were used as model to investigate the metastatic behavior of rhabdomyosarcoma cells engineered to improve the differentiation. It has been recently shown that this immunodeficient model can be reconstituted with a human immune system through the injection of human cord blood progenitor cells. The work illustrated in this thesis revealed that the injection of different human progenitor cells (CD34+ or CD133+) showed peculiar engraftment and differentiation abilities. Experiments of cell vaccination were performed to investigate the functionality of the engrafted human immune system and the induction of specific human immune responses. Results from such experiments will allow to collect informations about human immune responses activated during cell vaccination and to define the best reconstitution and experimental conditions to create a humanized model in which to study, in a preclinical setting, immunological antitumor strategies.

New insights into methodology and interpretation of osteoarthritis. The study of Frassetto identified skeletal collection.

Osteoarthritis (OA) or degenerative joint disease (DJD) is a pathology which affects the synovial joints and characterised by a focal loss of articular cartilage and subsequent bony reaction of the subcondral and marginal bone. Its etiology is best explained by a multifactorial model including: age, sex, genetic and systemic factors, other predisposing diseases and functional stress. In this study the results of the investigation of a modern identified skeletal collection will be presented. In particular, we will focus on the relationship between the presence of OA at various joints. The joint modifications have been analysed using a new methodology that allows the scoring of different degrees of expression of the features considered. Materials and Methods The sample examined comes from the Sassari identified skeletal collection (part of “Frassetto collections”). The individuals were born between 1828 and 1916 and died between 1918 and 1932. Information about sex and age is known for all the individuals. The occupation is known for 173 males and 125 females. Data concerning the occupation of the individuals indicate a preindustrial and rural society. OA has been diagnosed when eburnation (EB) or loss of morphology (LM) were present, or when at least two of the following: marginal lipping (ML), esostosis (EX) or erosion (ER), were present. For each articular surface affected a “mean score” was calculated, reflecting the “severity” of the alterations. A further “score” was calculated for each joint. In the analysis sexes and age classes were always kept separate. For the statistical analyses non parametric test were used. Results The results show there is an increase of OA with age in all the joints analyzed and in particular around 50 years and 60 years. The shoulder, the hip and the knee are the joints mainly affected with ageing while the ankle is the less affected; the correlation values confirm this result. The lesion which show the major correlation with age is the ML. In our sample males are more frequently and more severely affected by OA than females, particularly at the superior limbs, while hip and knee are similarly affected in the two sexes. Lateralization shows some positive results in particular in the right shoulder of males and in various articular surfaces especially of the superior limb of both males and females; articular surfaces and joints are quite always lateralized to the right. Occupational analyses did not show remarkable results probably because of the homogeneity of the sample; males although performing different activities are quite all employed in stressful works. No highest prevalence of knee and hip OA was found in farm-workers respect to the other males. Discussion and Conclusion In this work we propose a methodology to score the different features, necessary to diagnose OA, that allows the investigation of the severity of joint degeneration. This method is easier than the one proposed by Buikstra and Ubelaker (1994), but in the same time allows a quite detailed recording of the features. Epidemiological results can be interpreted quite simply and they are in accordance with other studies; more difficult is the interpretation of the occupational results because many questions concerning the activities performed by the individuals of the collection during their lifespan cannot be solved. Because of this, caution is suggested in the interpretation of bioarcheological specimens. With this work we hope to contribute to the discussion on the puzzling problem of the etiology of OA. The possibility of studying identified skeletons will add important data to the description of osseous features of OA, enriching the medical documentation, based on different criteria. Even if we are aware that the clinical diagnosis is different from the palaeopathological one we think our work will be useful in clarifying some epidemiological as well as pathological aspects of OA.

New molecular approaches to control rhabdomyosarcoma onset and metastasis in preclinical systems

Rhabdomyosarcoma is the most common soft tissue sarcoma of childhood. The aim of this study was to identify molecular events involved in rhabdomyosarcoma onset for the development of new therapeutic approaches against specific molecular targets. BALB-p53neu mice develop pelvic rhabdomyosarcoma and combines the activation of HER-2/neu oncogene with the inactivation of an allele of p53 oncosuppressor gene. Gene expression profiling led to the identification of genes potentially involved in rhabdomyosarcoma genesis and therefore of candidate targets. The pattern of expression of p53, HER-2/neu, CDKN2A/p19ARF and IGF-2 suggested that these alterations might be involved in gender-, site- and strain-specific development of rhabdomyosarcoma. Other genes such as CDKN1A/p21 might be involved. The role of IGF-2, CDKN2A/p19ARF and CDKN1A/p21 in tumor growth was investigated with siRNA in murine rhabdomyosarcoma cells. Silencing of p19ARF and p21 induced inhibition of growth and of migration ability, indicating a possible pro-tumor and pro-metastatic role in rhabdomyosarcoma in absence of p53. In addition the autocrine IGF-2/IGF-1R loop found in early phases of cancer progression strengthens its key role in sustaining rhabdomyosarcoma growth. As rhabdomyosarcoma displays defective myogenic differentiation, a therapeutic approach aimed at enhancing myogenic differentiation of rhabdomyosarcoma cells. Forced expression of myogenin was able to restore myogenic differentiation, significantly reduced cell motility and impaired tumor growth and metastatic spread. IL-4 treatment increased rhabdomyosarcoma cell growth, decreased myogenin expression and promoted migration of cells lacking myogenin. Another approach was based on small kinase inhibitors. Agents specifically targeting members of the HER family (Lapatinib), of the IGF system (NVP-AEW541) or downstream signal transducers (NVP-BEZ235) were investigated in vitro in human rhabdomyosarcoma cell lines as therapeutic anti-tumor and anti-metastatic tools. The major effects were obtained with NVP-BEZ235 treatment that was able to strongly inhibit cell growth in vitro and showed anti-metastatic effects in vivo.

Caratteristiche cliniche ed ecografiche dei Sarcomi Uterini

Obiettivo: descrivere le caratteristiche ecografiche e flussimetriche dei sarcoma uterini Materiali e Metodi: Dall'archivio anatomopatologico di due cliniche Universitarie sono state reclutate retrospettivamente tutte le pazienti con diagnosi anatomopatologica di sarcoma uterino. Tutte le cartelle cliniche, le immagini e i filmati digitalizzati sono stati analizzati e dati raccolti in un database. Risultati: Sono stati inclusi nello studio 49 casi, che comprendono 17 leiomiosarcoma, 14 sarcoma dello stroma endometriale e 18 carcinosarcoma. L'età media alla diagnosi è stata 62 anni (range 35-87). L'ottanta per cento delle pazienti erano in menopausa al momento della diagnosi. Circa la metà delle pazienti presentavano sanguinamento anomalo e il 20% dolore pelvico. La maggior parte delle lesioni sono apparse iso-ipoecogene, senza coni d’ombra (47/49;96%). Conclusioni: I sarcomi uterini sono un gruppo eterogeneo di tumori che presentano aspetti ecografici diversi anche in relazione all’istotipo. Conoscere le diverse caratteristiche può essere utile ai fini di una corretta diagnosi. Nel nostro studio l’assenza dei coni d’ombra risulta essere l’aspetto più significativo.

Bedeutung der synovialen Strukturqualität für die Ernährung des Chondrozyten

In dieser Arbeit wird eine Einteilung der degenerativen strukturellen Veränderungen der Synovialmembran vorgestellt. Anhand der Kriterien Fibrosierung des Stromas, Rückgang des Gefäßnetzes, Auftreten von Hyalinose und chondroider Metaplasie mit und ohne Nachweis von CPPD Kristallen wurden Präparate der Synovialmembran von 59 Patienten mit Nachweis degenerativer strukturellen Veränderungen in 4 Stadien eingeteilt. rnHyalinose (Stadium 3) konnte in den untersuchten Schnitten nur relativ selten beobachtet werden, so dass am ehesten von einem Vorstadium zur chondroiden Metaplasie auszugehen ist. rnDie Verteilung der Erkrankungsdauer und des Alters in den verschiedenen Stadien lassen darauf schließen, dass höhere Stadien mit höherem Alter und längerer Erkrankungsdauer korrelieren. rnAus der vorhandenen Literatur ergeben sich Hinweise, welche Faktoren zu der Entstehung der strukturellen Veränderungen beitragen können: rnAus dem Netzwerk der Zytokine scheinen TGF-beta und die BMP’s an der Zunahme der Fibrose und an der Entstehung chondroider Metaplasie beteiligt zu sein. Makrophagen scheinen dabei eine wichtige Rolle zu spielen. Dies weist darauf hin, dass entzündliche und strukturelle Veränderungen miteinander vernetzt sind. rnBei der Entstehung der chondroiden Metaplasie kommen zusätzlich mechanische Einflüsse in Form von zyklischen Kompressionen als Einflussfaktor in Frage. rnDie Regulierung der Angiogenese ist noch zu wenig verstanden, um den Gefäßrückgang bei fortgeschrittenen strukturellen Veränderungen zu erklären. Erklärungsansätze sind zum einen zunehmende mechanische Schädigung bei zunehmender Inkongruenz der Gelenkflächen. Zum anderen könnte eine beginnende chondroide Metaplasie mit Expression von Chondromodulin I eine entscheidende Rolle spielen. rnInsgesamt muss man davon ausgehen, dass die zunehmenden strukturellen Veränderungen die Ernährung des Knorpels erschweren. Dabei ist an erster Stelle der Rückgang des Gefäßnetzes zu nennen. Dies erschwert nicht nur die Versorgung mit Nährstoffen, sondern auch den Abtransport von Stoffwechselprodukten. Ab einem gewissen Punkt ist aber auch davon auszugehen, dass die Funktion der Deckzellschicht beeinträchtigt wird. Wenn die Konzentration der Hyaluronsäure in der Synovia dadurch sinkt, kann dies durch eine vermehrte Permeabilität der Synovialmembran zum verstärkten Ausstrom von Wasser aus der Gelenkhöhle führen. Durch ein Ödem des umliegenden Gewebes kann dadurch der Blutfluss im Bereich des Gelenks zusätzlich vermindert werden. rnAuch die zunehmende Fibrosierung der Synovialmembran kann einen Einfluss auf die Permeabilität der Synovialmembran haben. Ob und in welchen Stadien der Veränderungen das einen relevanten Einfluss für die Ernährung der Chondrozyten hat, ist noch unklar.rn

La navigazione nella chirurgia oncologica ortopedica: Applicazione ed implementazione di nuove tecnologie per il trattamento chirurgico dei tumori dell'apparato muscolo-scheletrico, studio pilota

Nel presente progetto di ricerca, da novembre 2011 a novembre 2013 , sono stati trattati chirurgicamente, con l’assistenza del navigatore , pazienti con tumori ossei primitivi degli arti, del bacino e del sacro, analizzando i risultati degli esami istologici dei margini di resezione del tumore e i risultati clinici e radiografici. Materiali e metodi : Abbiamo analizzato 16 pazienti 9 maschi e 7 femmine , con un'età media di 31 anni (range 12-55 ). Di tutti i pazienti valutati 8 avevano una localizzazione agli arti inferiori , 4 al bacino e 4 all'osso sacro . Solo quelli con osteosarcoma parostale , Cordoma e Condrosarcoma non sono stati sottoposti a terapia antiblastica . Solo un paziente è stato sottoposto a radioterapia postoperatoria per una recidiva locale . Tutti gli altri pazienti non sono stati trattati con la radioterapia per l’ adeguatezza dei margini di resezione . Non ci sono state complicanze intraoperatorie . Nel periodo postoperatorio abbiamo osservato una vescica neurologica , una paresi sciatica, due casi di infezione di cui una superficiale e una profonda, tutti e quattro i pazienti con sarcoma sacrale sviluppati hanno avuto ritardato della guarigione della ferita e di questi tre hanno avuto incontinenza sfinterica. In tutti i casi si è ottenuta una eccellente risultato clinico e radiografico , con soddisfazione del paziente , corretto contatto tra l'osteotomia e l'impianto che apparivano stabili ai primi controlli ambulatoriali ( FU 19 mesi). Risultati: La chirurgia assistita da calcolatore ha permesso di migliorare l’esecuzione delle resezioni ossee prevista dal navigatore. Questa tecnologia è valida e utile per la cure dei tumori dell’apparato scheletrico, soprattutto nelle sedi anatomiche più complesse da trattare come la pelvi, il sacro e nelle resezioni intercalari difficoltose nell’ottenere un margine di resezione ampio e quindi di salvare l’articolazione e l’arto stesso.

Efficacia clinica dello stanozololo intrarticolare nella terapia dell'osteoartrosi di gomito nel cane

Il trattamento dell’osteoartrosi (OA) del cane è una sfida nella pratica clinica veterinaria. Molti trattamenti sono stati proposti, tuttavia la risposta clinica agli stessi non è sempre soddisfacente. Molti farmaci sono utilizzati per il trattamento dell’OA, tra cui farmaci anti-infiammatori non steroidei, corticosteroidi, ed inibitori della produzione dell’ossido nitrico. Lo stanozololo è un derivato sintetico del testosterone; oltre alle sue proprietà anaboliche/androgeniche , a basse dosi lo stanozololo ha un affinità per i recettori glucocorticoidi. Per questa attività antinfiammatoria e rigenerativa sui tessuti articolari danneggiati viene utilizzato nella degenerative joint desease del cavallo. Lo scopo di questo studio è stato di valutare l’efficacia clinica dello stanozololo intra-articolare a 15, 30, 45 e 60 giorni dal trattamento di gomiti con OA di cane. E’ stato eseguito uno studio cieco, multicentrico e randomizzato. Previo consenso informato, sono stati arruolati 48 cani, suddivisi in 3 gruppi e trattati con stanozololo, mavacoxib e con entrambi i farmaci. Sono state valutate zoppia, tollerabilità del trattamento, range of motion, e punteggio radiografico. Inoltre sono state stabilite e annoverate quantità e qualità del liquido sinoviale. Ai dati ottenuti sono stati applicati i test di Kruskal-Wallis, Chi-quadro e Fischer, i quali hanno dimostrato l’efficacia della terapia nei singoli gruppi e tra i diversi gruppi di studio. I risultati ottenuti hanno mostrato la riduzione di almeno un grado di zoppia e la riduzione della progressione dell’OA nei casi trattati con stanozololo. Si può quindi affermare che tale molecola per via intra-articolare può essere una valida alternativa per il trattamento dell’OA di gomito nel cane.

Nuovi metodi di diagnosi precoce dei fallimenti di protesi d'anca con accoppiamento articolare ceramica-ceramica

L’accoppiamento articolare in ceramica è sempre più utilizzato in chirurgia protesica dell’anca per le sue eccellenti proprietà tribologiche. Tuttavia la fragilità della ceramica è causa di fallimenti meccanici. Abbiamo quindi condotto una serie di studi al fine di individuare un metodo efficace di diagnosi precoce del fallimento della ceramica. Abbiamo analizzato delle componenti ceramiche espiantate e abbiamo trovato un pattern di usura pre-frattura che faceva supporre una dispersione di particelle di ceramica nello spazio articolare. Per la diagnosi precoce abbiamo validato una metodica basata sulla microanalisi del liquido sinoviale. Per validare la metodica abbiamo eseguito un agoaspirato in 12 protesi ben funzionanti (bianchi) e confrontato i risultati di 39 protesi con segni di rottura con quelli di 7 senza segni di rottura. Per individuare i pazienti a rischio rottura i dati demografici di 26 pazienti con ceramica rotta sono stati confrontati con 49 controlli comparabili in termini demografici, tipo di ceramica e tipo di protesi. Infine è stata condotta una revisione sistematica della letteratura sulla diagnosi della rottura della ceramica. Nell’aspirato la presenza di almeno 11 particelle ceramiche di dimensioni inferiori a 3 micron o di una maggiore di 3 micron per ogni campo di osservazione sono segno di rottura della ceramica. La metodica con agoaspirato ha 100% di sensibilità e 88 % di specificità nel predire rotture della ceramica. Nel gruppo delle ceramiche rotte è stato trovato un maggior numero di malposizionamenti della protesi rispetto ai controlli (p=0,001). Il rumore in protesi con ceramica dovrebbe sollevare il sospetto di fallimento ed indurre ad eseguire una TC e un agoaspirato. Dal confronto con la letteratura la nostra metodica risulta essere la più efficace.

Identificazione dei meccanismi molecolari responsabili del ruolo oncosoppressivo della molecola CD99 nell'osteosarcoma

CD99, glicoproteina di membrana codificata dal gene MIC2, è coinvolta in numerosi processi cellulari, inclusi adesione, migrazione, apoptosi, differenziamento e regolazione del trafficking intracellulare di proteine, in condizioni fisiologiche e patologiche. Nell’osteosarcoma risulta scarsamente espressa ed ha ruolo oncosoppressivo. L’isoforma completa (CD99wt) e l’isoforma tronca (CD99sh), deleta di una porzione del dominio intracellulare, influenzano in modo opposto la malignità tumorale. In questo studio, comparando cellule di osteosarcoma caratterizzate da differenti capacità metastatiche e diversa espressione di CD99, abbiamo valutato la modulazione dei contatti cellula-cellula, la riorganizzazione del citoscheletro di actina e la modulazione delle vie di segnalazione a valle del CD99, al fine di identificare i meccanismi molecolari regolati da questa molecola e responsabili del comportamento migratorio e invasivo delle cellule di osteosarcoma. L'espressione forzata di CD99wt induce il reclutamento di N-caderina e β-catenina a livello delle giunzioni aderenti ed inibisce l'espressione di molecole cruciali nel processo di rimodellamento del citoscheletro di actina, come ACTR2, ARPC1A, Rho-associated, coiled–coil-containing protein kinase 2 (ROCK2), nonché di ezrina, membro della famiglia ezrin/radixin/moesin e chiaramente associata con la progressione tumorale e la metastatizzazione dell’OS. Gli studi funzionali identificano ROCK2 come mediatore fondamentale nella regolazione della migrazione e della diffusione metastatica dell’osteosarcoma. Mantenendo cSRC in una conformazione inattiva, CD99wt inibisce la segnalazione mediata da ROCK2 inducendo una diminuzione dell’ezrina a livello della membrana accompagnata dalla traslocazione in membrana di N-caderina e β-catenina, principali ponti molecolari per il citoscheletro di actina. La ri-espressione di CD99wt, generalmente presente negli osteoblasti, ma perso nelle cellule di osteosarcoma, attraverso l'inibizione dell'attività di cSrc e ROCK2, aumenta la forza di contatto e riattiva i segnali anti-migratori ostacolando l’azione pro-migratoria, altrimenti dominante, dell’ezrina nell’osteosarcoma. Abbiamo infine valutato la funzione di ROCK2 nel sarcoma di Ewing: nonostante il ruolo oncogenico esercitato da CD99, ROCK2 guida la migrazione cellulare anche in questa neoplasia.

Analyse humaner regulatorischer T-Zellen im humanisierten Mausmodell

Regulatorische T-Zellen sind essentiell für die Aufrechterhaltung der peripheren Toleranz. Hierbei sorgen diese hocheffektiven Suppressorzellen für ein immunologisches Gleichgewicht, indem sie Immunantworten gegen Autoantigene sowie harmlose Nahrungs- und Umweltantigene verhindern. Andererseits können diese bei chronischen Infekten Immunantworten reduzieren sowie effektive Antitumor-Immunantworten hemmen. Aufgrund ethischer Erwägungen ist die Erforschung regulatorischer T-Zellen und deren Rolle bei der Tumorentwicklung weitestgehend auf Mausmodelle oder humane in vitro oder ex vivo Analysen beschränkt. Um diese Limitationen zu überwinden und translationale immunologische Experimente zu ermöglichen, wurde hier ein humanisiertes Mausmodell verwendet. T- und B-Zell-defiziente NOD-scid IL2Rgammanull (NSG) Mäuse wurden mit humanen CD34+ hämatopoetischen Stammzellen aus Nabelschnurblut rekonstituiert. Aus diesen Stammzellen entstanden in den Tieren vielfältige humane Immunzellen. Im murinen Thymus der NSG Tiere entwickelten sich CD4+ und CD8+ einzelpositive T-Zellen, welche als funktionelle Effektorpopulationen in die Peripherie auswanderten. Humane regulatorische T-Zellen (CD4+ CD25+ Foxp3+ CD127-) entwickelten sich ebenfalls im murinen Thymus der Tiere und machten ca. 10% der humanen peripheren CD4+ T-Zellen in den Mäusen aus. Diese humanen regulatorischen T-Zellen zeigten vorwiegend einen HLA-DR+ Phänotyp, welcher mit höchster Suppressivität assoziiert ist. Weiter verhielten sich die regualtorischen T-Zellen anergisch und bewiesen ihre Funktionalität unter anderem durch die Inhibition der Proliferation von Effektor-T-Zellen in vitro. rnSubkutan injizierte Tumorzellen eines humanen undifferenzierten pleomorphen Sarkoms wurden in den humanisierten Mäusen nicht abgestoßen und der Tumor konnte, trotz Infiltration humaner Immunzellen, ungehindert wachsen. Als mögliche Ursache hierfür zeigte sich die selektive Akkumulation regulatorischer T-Zellen im Tumor. Zusammen mit dem erhöhten Anteil humaner regulatorischer T-Zellen in der Peripherie, weisen diese Beobachtungen deutliche Parallelen mit Befunden aus humanen Patienten auf. Dies bietet somit erstmalig die Option in vivo die Rolle humaner regulatorischer T-Zellen im undifferenzierten pleomorphen Sarkom zu analysieren. Die hier gezeigten Daten machen deutlich, dass es das humanisierte Mausmodell ermöglicht, die Entstehung und Funktion humaner regulatorischer T-Zellen in vivo zu analysieren, deren Bedeutung in klinisch relevanten Modellen zu charakterisieren und somit innovative Therapien zu etablieren.

Rapid spontaneous malignant progression of supratentorial tanycytic ependymoma with sarcomatous features - "Ependymosarcoma"

By analogy to gliosarcoma, the term "ependymosarcoma" has recently been coined to thematize the rare phenomenon of a malignant mesenchymal component arising within an ependymoma. We report on an example of this paradigm, involving tanycytic ependymoma as the host tumor in a 40-year-old female who underwent two tumor extirpation procedures at one-year interval. She first presented with severe headaches, and was seen by imaging to harbor a moderately enhancing mass 2.5cm in diameter at the rostral septum pellucidum accompanied by occlusive hydrocephalus. Microscopically, the tumor consisted of solid, wavy fascicles of elongated cells that were occasionally interrupted by vague perivascular pseudorosettes. Mitotic activity was absent, and less than 1% of nuclei immunoreacted for MIB-1. A histological diagnosis of tanycytic ependymoma (WHO grade II) was rendered, and no adjuvant therapy given. At recurrence, the lesion was 3.5cm in diameter, intensely enhancing, and had already seeded into the subarachnoid space. Histology showed a biphasic glial-sarcomatous architecture with remnants of the original ependymoma now displaying hypercellularity and atypical - yet not frankly anaplastic - features. The sarcomatous moiety consisted of spindle and epithelioid cells densely interwoven with reticulin fibers. While the ependymal component was GFAP and S100 protein positive, and featured punctate staining for EMA, none of these markers was expressed in the adjacent sarcoma. Instead, the latter reacted for vimentin and smooth muscle actin. To the best of our knowledge, this is the first documentation of tanycytic ependymoma undergoing malignant transformation, one driven by a highly anaplastic mesenchymal component, corresponding to "ependymosarcoma".

Immune reconstitution inflammatory syndrome in patients starting antiretroviral therapy for HIV infection: a systematic review and meta-analysis

In patients with HIV-1 infection who are starting combination antiretroviral therapy (ART), the incidence of immune reconstitution inflammatory syndrome (IRIS) is not well defined. We did a meta-analysis to establish the incidence and lethality of the syndrome in patients with a range of previously diagnosed opportunistic infections, and examined the relation between occurrence and the degree of immunodeficiency. Systematic review identified 54 cohort studies of 13 103 patients starting ART, of whom 1699 developed IRIS. We calculated pooled cumulative incidences with 95% credibility intervals (CrI) by Bayesian methods and did a random-effects metaregression to analyse the relation between CD4 cell count and incidence of IRIS. In patients with previously diagnosed AIDS-defining illnesses, IRIS developed in 37.7% (95% CrI 26.6-49.4) of those with cytomegalovirus retinitis, 19.5% (6.7-44.8) of those with cryptococcal meningitis, 15.7% (9.7-24.5) of those with tuberculosis, 16.7% (2.3-50.7) of those with progressive multifocal leukoencephalopathy, and 6.4% (1.2-24.7) of those with Kaposi's sarcoma, and 12.2% (6.8-19.6) of those with herpes zoster. 16.1% (11.1-22.9) of unselected patients starting ART developed any type of IRIS. 4.5% (2.1-8.6) of patients with any type of IRIS died, 3.2% (0.7-9.2) of those with tuberculosis-associated IRIS died, and 20.8% (5.0-52.7) of those with cryptococcal meningitis died. Metaregression analyses showed that the risk of IRIS is associated with CD4 cell count at the start of ART, with a high risk in patients with fewer than 50 cells per microL. Occurrence of IRIS might therefore be reduced by initiation of ART before immunodeficiency becomes advanced.

Changing patterns of cancer incidence in the early- and late-HAART periods: the Swiss HIV Cohort Study

The advent of highly active antiretroviral therapy (HAART) in 1996 led to a decrease in the incidence of Kaposi's sarcoma (KS) and non-Hodgkin's lymphoma (NHL), but not of other cancers, among people with HIV or AIDS (PWHA). It also led to marked increases in their life expectancy.

[Ultrasound and arthritis]

Musculoskeletal ultrasonography (US) is an established and validated imaging technique in rheumatology. Ultrasonography is able to directly visualize soft tissue pathologies such as synovial tissue changes. Pathological findings in superficial cartilage, bone lesions and synovial tissue changes in the context of rheumatoid arthritis, spondyloarthritis or crystal arthropathies may only be seen by sonography or detected earlier by ultrasonography compared to conventional imaging techniques. The activity of an inflammatory arthropathy can be visualized using Doppler and power Doppler US. US is helpful in the detection of early inflammatory changes, particularly in patients with undifferentiated arthritis and/or unremarkable conventional radiography. In addition to diagnosis in early arthritis and monitoring of therapy in rheumatoid arthritis, sonography is able to detect pivotal pathologies in spondyloarthritis and crystal deposition diseases such as gout, pseudogout and apatite deposition disease. Ultrasound-guided diagnostic and therapeutic interventions are characterized by their excellent accuracy and improvement of clinical effectiveness compared to unguided procedures. In conclusion, ultrasonography plays a pivotal role in the assessment and monitoring of therapy in rheumatic diseases.