Chronic maxillary sinusitis associated with dental impression material

A 62-year-old man was referred for routine treatment of hyperplasia of the mucosa in the anterior lower jaw. An oroantral fistula was detected in the right superior alveolar ridge. The patient had no complaints. Plain radiographs showed a radiopaque foreign body in the posterior region associated with opacification of the maxillary sinus. Computed tomography showed the same hyperdense foreign body located in the posterior lower part of the sinus and an abnormal soft tissue mass in the entire right maxillary sinus. When asked about sinusitis, the patient mentioned occasional episodes of pus taste and intermittent crises of headache lasting for one week. The patient has been edentulous for 20 years. Sinus debridement was performed and the oroantral fistula was closed. The clinical suspicion of the presence of zinc oxide-eugenol paste was confirmed by microscopical and chemical analysis. After 6 months of follow-up, the fistula continued to be closed and sinusitis did not recur. This clinical case of maxillary chronic sinusitis illustrates a different odontogenic origin.

Effects of a mixture of growth factors and proteins on the development of the osteogenic phenotype in human alveolar bone cell cultures

Strategies to promote bone repair have included exposure of cells to growth factor (GF) preparations from blood that generally include proteins as part of a complex mixture. This study aimed to evaluate the effects of such a mixture on different parameters of the development of the osteogenic phenotype in vitro. Osteoblastic cells were obtained by enzymatic digestion of human alveolar bone and cultured under standard osteogenic conditions until subconfluence. They were subcultured on Thermanox coverslips up to 14 days. Treated cultures were exposed during the first 7 days to osteogenic medium supplemented with a GFs + proteins mixture containing the major components found in platelet extracts [plate I et-derived growth factor-BB, transforming growth factor (TGF)-beta 1, TGF-beta 2, albumin, fibronectin, and thrombospondin] and to osteogenic medium alone thereafter. Control cultures were exposed only to the osteogenic medium. Treated cultures exhibited a significantly higher number of adherent cells from day 4 onward and of cycling cells at days 1 and 4, weak alkaline phosphatase (ALP) labeling, and significantly decreased levels of ALP activity and mRNA expression. At day 14, no Alizarin red-stained nodular areas were detected in cultures treated with GFs + proteins. Results were confirmed in the rat calvaria-derived osteogenic cell culture model. The addition of bone morphogenetic protein 7 or growth and differentiation factor 5 to treated cultures upregulated Runx2 and ALP mRNA expression, but surprisingly, ALP activity was not restored. These results showed that a mixture of GFs + proteins affects the development of the osteogenic phenotype both in human and rat cultures, leading to an increase in the number of cells, but expressed a less differentiated state.

Does research into sensitive areas do harm? Experiences of research participation after a child's diagnosis with Ewing's sarcoma

Objective: To investigate family members' experiences of involvement in a previous study (conducted August 1995 to June 1997) following their child's diagnosis with Ewing's sarcoma. Design: Retrospective survey, conducted between 1 November and 30 November 1997, using a postal questionnaire. Participants: Eighty-one of 97 families who had previously completed an in-depth interview as part of a national case-control study of Ewing's sarcoma. Main outcome measures: Participants' views on how participation in the previous study had affected them and what motivated them to participate. Results: Most study participants indicated that taking part in the previous study had been a positive experience. Most (n = 79 [97.5%]) believed their involvement would benefit others and were glad to have participated, despite expecting and finding some parts of the interview to be painful. Parents whose child was still alive at the time of the interview recalled participation as more painful than those whose child had died before the interview. Parents who had completed the interview less than a year before our study recalled it as being more painful than those who had completed it more than a year before. Conclusions: That people suffering bereavement are generally eager to participate in research and may indeed find it a positive experience is useful information for members of ethics review boards and other gatekeepers, who frequently need to determine whether studies into sensitive areas should be approved. Such information may also help members of the community to make an informed decision regarding participation in such research.

Contributo dos músculos respiratórios para a fisiopatologia da hipercápnia na doença pulmonar crónica estabilizada: parte 1 = The role of the respiratory muscles in the pathophisiology of chronic hypercapnia in clinically stable chronic obstructive pulmonary diseases: part 1

Rev Port Pneumol. VII(2): 191-208, 2001

Long-term behaviour of railway transitions under dynamic loading application to soft soil sites

Dissertação para obtenção do Grau de Doutor em Engenharia Civil

Saloplastic membranes as green devices for soft tissue regeneration

Implantable devices must exhibit mechanical properties similar to native tissues to promote appropriate cellular behavior and regeneration. Herein, we report a new membrane manufacture method based on the synthesis of polyelectrolyte complexes (PECs) that exhibit saloplasticity, i.e. variable physical-chemistry using salt as a plasticizer. This is a Green Chemistry approach, as PECs generate structures that are stabilized solely by reversible electrostatic interactions, avoiding the use of harmful crosslinkers completely. Furthermore, natural polyelectrolytes - chitosan and alginate - were used. Upon mixing them, membranes were obtained by drying the PECs at 37ºC, yielding compact PECs without resorting to organicsolvents. The plasticizing effect of salt after synthesis was shown by measuring tensile mechanical properties, which were lower when samples were immersed in high ionic strength solutions.Salt was also used during membrane synthesis in different quan- tities (0 M, 0.15 M and 0.5 M in NaCl) yielding structures with no significant differences in morphology and degradation (around 15% after 3 months in lysozyme). However, swelling was higher (about 10x) when synthesized in the presence of salt. In vitro cell studies using L929 fibroblasts showed that cells adhered and proliferated preferentially in membranes fabricated in the presence of salt (i.e. the membranes with lower tensile strength). Structures with physical-chemical properties controlled with precision open a path to tissue engineering strategies depending on fine tuning mechanical properties and cellular adhesion simply by changing ionic strength during membrane manufacture

Myopia control with a novel peripheral gradient soft lens and orthokeratology: a 2-year clinical trial

Objective. To evaluate the degree of axial elongation with soft radial refractive gradient (SRRG) contact lenses, orthokeratology (OK), and single vision (SV) spectacle lenses (control) during a period of 1 year before treatment and 2 years after treatment. Methods. This was a prospective, longitudinal, nonrandomized study. The study groups consisted of 30, 29, and 41 children, respectively. The axial length (AL) was measured during 2 years after recruitment and lens fitting. Results. The baseline refractive sphere was correlated significantly (r 2 = 0.542; P < 0.0001) with the amount of myopia progression before baseline. After 2 years, the mean myopia progression values for the SRRG, OK, and SV groups were −0.56 ± 0.51, −0.32 ± 0.53, and −0.98 ± 0.58 diopter, respectively. The results represent reductions in myopic progression of 43% and 67% for the SRRG and OK groups, respectively, compared to the SV group. The AL increased more in the SV group compared to the SRRG and OK groups, with 27% and 38% lower axial elongation, respectively, compared to the SV group at the 2-year visit (P < 0.05). SRRG and OK showed no differences (P = 0.430). Conclusion. The SRRG lens significantly decreased AL elongation compared to the SV control group. The SRRG lens was similarly effective to OK in preventing myopia progression in myopic children and adolescent.

Neo/adjuvant chemotherapy does not improve outcome in resected primary synovial sarcoma: a study of the French Sarcoma Group.

BACKGROUND: There are only scarce data about the benefit of adjunctive chemotherapy in patients with localized synovial sarcoma (SS). PATIENTS AND METHODS: Data from 237 SS patients recorded in the database of the French Sarcoma Group were retrospectively analyzed. The respective impact of radiotherapy, neo-adjuvant chemotherapy and adjuvant chemotherapy on overall survival (OS), local recurrence-free survival (LRFS) and distant recurrence-free survival (DRFS) were assessed after adjustment to prognostic factors. RESULTS: The median follow-up was 58 months (range 1-321). Adjuvant, neo-adjuvant chemotherapy and postoperative radiotherapy were administered in 112, 45 and 181 cases, respectively. In all, 59% of patients treated with chemotherapy received an ifosfamide-containing regimen. The 5-year OS, LRFS and DRFS rates were 64.0%, 70% and 57%, respectively. On multivariate analysis, age >35 years old, grade 3 and not-R0 margins were highly significant independent predictors of worse OS. After adjustment to prognostic factors, radiotherapy significantly improved LRFS but not DRFS or OS. Neither neo-adjuvant nor adjuvant chemotherapy had significant impact on OS, LRFS or DRFS. CONCLUSION: As for other high-grade soft-tissue sarcomas, well-planned wide surgical excision with adjuvant radiotherapy remains the cornerstone of treatment for SS. Neo-adjuvant or adjuvant chemotherapy should not be delivered outside a clinical trial setting.

Role of microRNAs in the pathogenesis of Ewing's sarcoma

SummaryEwing's sarcoma family tumors (ESFT) are the second most frequent cancer of bone in adolescents and young adults. ESFT are characterized by a chromosomal translocation that involves the 5' segment of the EWSR1 gene and the 3' segment of an ets transcription factor family member gene. In 85% of cases the chromosomal translocation generates the fusion protein EWSR1-FLI-1. Recent work from our laboratory identified mesenchymal stem cells (MSC) as the putative cell of origin of ESFT and characterized a CD133+ subpopulation of ESFT cells with tumor initating and self-renewal capacity, known as cancer stem cells (CSC). MicroRNAs (miRNAs) are small non-coding RNA that regulate protein expression at the post-transcriptional level by either repressing translation or destabilizing mRNA. MiRNAs participate in several biological processes including cell proliferation and differentiation. We used miRNA expression profile comparison between MSC and ESFT cell lines and CD133+ ESFT cells and CD133" ESFT cells to investigate the role of miRNAs in ESFT pathogenesis. MiRNA expression profile comparison of MSC and ESFT cell lines identified 35 differentially expressed miRNAs. Among these was down-regulation of let-7a which results, in part, by the direct repression of let-7a-l promoter by EWSR1-FLI-1. Overexpression of let-7a in ESFT cells blocked ESFT tumorigenesis through an High-motility group AT-hook2 (HMGA2)-mediated mechanism.MiRNA profiling of CD133+ ESFT and CD 133" ESFT cells revealed a broad repression of miRNAs in CD133+ ESFT mediated by down-regulation of TARBP2, a central regulator of the miRNA maturation pathway. Down-regulation of TARBP2 in ESFT cell lines results in a miRNA expression profile reminescent of that observed in CD133+ ESFT and associated with increased tumorigenicity. Enhancement of TARBP2 activity using the antibiotic enoxacin or overexpression of miRNA-143 or miRNA-145, two targets of TARBP2, impaired ESFT CSC self-renewal and block ESFT tumorigenicity. Moreover in vivo administration of synthetic let- 7a, miRNA-143 or miRNA-145 blocks ESFT tumor growth.Thus, dysregulation of miRNA expression is a key feature in ESFT pathogenesis and restoration of their expressions might be used as a new therapeutic tool.RésuméLe sarcome d'Ewing est la deuxième tumeur osseuse la plus fréquente chez l'enfant et le jeune adolescent. Le sarcome d'Ewing est caractérisé par une translocation chromosomique qui produit une protéine de fusion EWSR1-FLI-1. Des récents travaux ont identifié les cellules mésenchymateuses souches (MSC) comme étant les cellules à l'origine du sarcome d'Ewing ainsi qu'une sous-population de cellules exprimant le marqueur CD 133, dans le sarcome d'Ewing connu comme les cellules cancéreuses souches (CSC). Ces cellules ont la capacité d'initier la croissance tumorale et possèdent des propriétés d'auto-renouvellement. Les microRNAs (miRNAs) sont de petits ARN qui ne codent pas pour des protéines et qui contrôlent l'expression des protéines en bloquant la traduction ou en dégradant l'ARNm. Les miRNAs participent à différents processus biologiques comme la prolifération et la différenciation cellulaires.Le but de ce travail est d'étudier le rôle des miRNAs dans le sarcome d'Ewing. Un profil d'expression de miRNAs entre les MSC et des lignées cellulaires de sarcome d'Ewing a mis en évidence 35 miRNAs différemment exprimés. Parmi ceux-ci, la répression de let-7a est liée à la répression directe du promoteur de let-7a-l par EWSR-FLI-1. La sur-expression de let-7a dans des lignées cellulaires de sarcome d'Ewing inhibe leur croissance tumorale. Cette inhibition de croissance tumorale est régulée par la protéine high-motility group AT-hook2 (HMGA2).Un profil d'expression de miRNAs entre les cellules du sarcome d'Ewing CD133+ et CD133" montre une sous-expression d'un grand nombre de miRNAs dans les cellules CD133+ par rapport aux cellules CD133". Cette différence d'expression de miRNAs est due à la répression du gène TARBP2 qui participe à la maturation des miRNAs. La suppression de TARBP2 dans des cellules d'Ewing induit un profil d'expression de miRNAs similaire aux cellules CD133+ du sarcome d'Ewing et augmente la tumorigenèse des lignées cellulaires. De plus l'utilisation d'enoxacin, une molécule qui augmente l'activité de TARBP2 ou la sur- expression des miRNA143 ou miRNA-145 dans les CSC du sarcome d'Ewing bloque l'auto- renouvellement des cellules et la croissance tumorale. Finalement, l'administration de let-7a, miRNA-143 ou miRNA-145, dans des souris bloque la croissance du sarcome d'Ewing. Ces résultats indiquent que la dysrégulation des miRNAs participe à la pathogenèse du sarcome d'Ewing et que les miRNAs peuvent être utilisés comme des agents thérapeutiques.

Development of Ewing's sarcoma from primary bone marrow-derived mesenchymal stem cells

SUMMARY : Ewing's sarcoma is a member of Ewing's family tumors (ESPY) and the second most common solid bone and soft tissue malignancy of children and young adults. It is associated in 85% of cases with the t(11;22)(q24:q12) chromosomal translocation that generates fusion of the 5' segment of the EWSR1 gene with the 3' segment of the ETS family gene FLI-1. The EWSR1-FLI-1 fusion protein behaves as an aberrant transcriptional activator and is believed to contribute to ESFT development. However, EWSR1-FLI-1 induces growth arrest and apoptosis in normal fibroblasts, and primary cells that are pemissive for its putative oncogenic properties have not been discovered, hampering basic understanding of ESFT biology. Here, we show that EWSR1-FLI-1 alone can transform mouse primary bone marrow-derived mesenchymal progenitor cells and generate tumors that display hallmarks of Ewing's sarcoma, including a small round cell phenotype, expression of ESFT-associated markers, insulin like growth factor-I dependence, and induction or repression of numerous EWSR1-FLI-1 target genes. Consistent with this finding, we tested the possibility that human mesenchymal stem cells (hMSC) might also provide a permissive cellular environment for EWSR1-FLI-1, and could represent the first adequate primary human cellular background for the oncogenic properties of the fusion protein. Indeed, expression of EWSR1-FLI-1 in human mesenchymal stem cells (hMSC) was not only stably maintained without inhibiting proliferation, but induced a gene expression profile bearing striking similarity to that of ESFT, including genes that are among the highest ESFT discriminators. Expression of EWSR1-FLI-1 in hMSCs may recapitulate the initial steps of Ewing's sarcoma development, allowing identification of genes that play an important role early in its pathogenesis. Among relevant candidate transcripts induced by EWSR1-FL/-1 in hMSC we found the polycomb group gene EZH2 which we show to play a critical role in Ewing's sarcoma growth. These observations provide the first identification of candidate primary cells from which ESFTs originate and suggest that EWSR1-FLI-1 expression may constitute the initiating event in ESFT pathogenesis. Le sarcome d' Ewing est un membre de la famille des tumeurs Ewing (ESFT) et représente la deuxième tumeur maligne solide de l'os et des tissus mous chez les enfants et les jeunes adultes. Cette tumeur est associée dans 85% des cas avec la translocation chromosomique t(11;22)(g24:g12), qui génère la fusion entre le segment 5' du gène EWSR1 avec le segment 3' du gène FLI-1, appartenant à la famille des facteurs de transcription ETS. La protéine de fusion EWSR1-FLI-1 qui en dérive joue le rSle d'un facteur de transcription aberrant, et est supposée contribuer de manière décisive au processus de développement des ESFTs. Néanmoins, l'expression de EWSR1-FLI-1 dans des fibroblastes normaux induit un arrêt de croissance et leur apoptose, et les cellules primaires permissives pour les propriétés oncogéniques attribuées à la translocation n'ont pas encore été identifiées, empêchant la compréhension de la biologie de base du sarcome d'Ewing. Dans ce travail on montre que l'expression de EWSR1-FLI-1 uniquement est capable de transformer des cellules souches mésenchymateuses dérivées de la moelle osseuse de la souris, pour générer des tumeurs qui présentent les caractéristiques du sarcome d' Ewing humain, et notamment une morphologie de petites cellules bleues et rondes, l'expression de marqueurs associés aux ESFTs, une dépendance du facteur de croissance IGF-1, et l'induction ou la répression de nombreux gènes cibles connus de EWSR1-FLI-1. Sur la base de ces observations, on a testé la possibilité que les cellules souches mésenchymateuses humaines (hMSCs) puissent aussi fournir un environnement cellulaire permissif pour EWSR1-FLI-1 ; et représenter le premier background cellulaire humain adéquat pour la manifestation du pouvoir oncogénique de la protéine de fusion. En effet, l'expression de EWSR1-FLI-1 dans des cellules souches mésenchymateuses humaines s'est révélée non seulement maintenue, mais elle a induit un profil d'expression génétique étonnamment similaire à celui des ESFTs humains, incluant les gènes qui ont été rapportés comme étant les plus discriminatifs pour ces tumeurs. L'expression de EWSR1-FLI-1 dans les hMSCs pourrait récapituler les étapes initiales du développement du sarcome d' Ewing, et de ce fait consentir à identifier les gènes qui jouent un rôle crucial dans sa pathogenèse précoce. Parmi les transcrits relevant indults par EWSR1-FL/-9 dans les hMSCs nous avons découvert le gène du groupe des polycomb EZH2, que nous avons par la suite démontré jouer un rôle essentiel dans la croissance du sarcome de Ewing. Ces observations apportent pour la première fois l'identification d'une cellule primaire candidate pour représenter la cellule d'origine des ESFTs, et en même temps suggèrent que l'expression de EWSR1-FLI-1 peut constituer l'événement initial dans la pathogenèse du sarcome d' Ewing.

Treatment of advanced soft-tissue sarcomas using a combined strategy of high-dose ifosfamide, high-dose doxorubicin and salvage therapies.

Having determined in a phase I study the maximum tolerated dose of high-dose ifosfamide combined with high-dose doxorubicin, we now report the long-term results of a phase II trial in advanced soft-tissue sarcomas. Forty-six patients with locally advanced or metastatic soft-tissue sarcomas were included, with age <60 years and all except one in good performance status (0 or 1). The chemotherapy treatment consisted of ifosfamide 10 g m(-2) (continuous infusion for 5 days), doxorubicin 30 mg m(-2) day(-1) x 3 (total dose 90 mg m(-2)), mesna and granulocyte-colony stimulating factor. Cycles were repeated every 21 days. A median of 4 (1-6) cycles per patient was administered. Twenty-two patients responded to therapy, including three complete responders and 19 partial responders for an overall response rate of 48% (95% CI: 33-63%). The response rate was not different between localised and metastatic diseases or between histological types, but was higher in grade 3 tumours. Median overall survival was 19 months. Salvage therapies (surgery and/or radiotherapy) were performed in 43% of patients and found to be the most significant predictor for favourable survival (exploratory multivariate analysis). Haematological toxicity was severe, including grade > or =3 neutropenia in 59%, thrombopenia in 39% and anaemia in 27% of cycles. Three patients experienced grade 3 neurotoxicity and one patient died of septic shock. This high-dose regimen is toxic but nonetheless feasible in multicentre settings in non elderly patients with good performance status. A high response rate was obtained. Prolonged survival was mainly a function of salvage therapies.

Development of Ewing's sarcoma from primary bone marrow-derived mesenchymal progenitor cells.

Ewing's sarcoma is a member of Ewing's family tumors (EFTs) and the second most common solid bone and soft tissue malignancy of children and young adults. It is associated in 85% of cases with the t(11;22)(q24:q12) chromosomal translocation that generates fusion of the 5' segment of the EWS gene with the 3' segment of the ETS family gene FLI-1. The EWS-FLI-1 fusion protein behaves as an aberrant transcriptional activator and is believed to contribute to EFT development. However, EWS-FLI-1 induces growth arrest and apoptosis in normal fibroblasts, and primary cells that are permissive for its putative oncogenic properties have not been discovered, hampering basic understanding of EFT biology. Here, we show that EWS-FLI-1 alone can transform primary bone marrow-derived mesenchymal progenitor cells and generate tumors that display hallmarks of Ewing's sarcoma, including a small round cell phenotype, expression of EFT-associated markers, insulin like growth factor-I dependence, and induction or repression of numerous EWS-FLI-1 target genes. These observations provide the first identification of candidate primary cells from which EFTs originate and suggest that EWS-FLI-1 expression may constitute the initiating event in EFT pathogenesis.

Telomerase activity and human telomerase reverse transcriptase mRNA expression in soft tissue tumors: correlation with grade, histology, and proliferative activity.

Telomerase activity (TA) is detected in most human cancers but, with few exceptions, not in normal somatic cells. Little is known about TA in soft tissue tumors. We have examined a series of benign and malignant soft tissue tumors for TA using the telomerase repeat amplification protocol assay. Analysis of the expression of the human telomerase reverse transcriptase was also carried out using RT-PCR. TA was undetectable in benign lesions (15 of 15) and low-grade sarcomas (6 of 6) and was detectable in 50% (19 of 38) of intermediate-/high-grade sarcomas. Although the presence of TA in soft tissue tumors is synonymous with malignancy, it is neither a reliable method in making the distinction between reactive/benign and malignant (especially low-grade) lesions nor a reliable marker of tumor aggressiveness. Leiomyosarcomas and storiform/pleomorphic malignant fibrous histiocytomas rarely showed TA, irrespective of their grade. A strong correlation between human telomerase reverse transcriptase mRNA expression and TA was observed, supporting the close relationship between both parameters. No significant relationship was observed between proliferative activity (as assessed by MIB-1 immunolabeling) and TA. We verified that the absence of telomerase expression was not due to the presence of telomerase inhibitors and therefore alternative mechanism(s) for cell immortalization, yet to be determined, seem to be involved in the development and/or maintenance of some soft tissue sarcomas.