Biocompatibility of Dental Amalgams

Objective. The purpose of this review paper is to review the literature regarding the toxicology of mercury from dental amalgam and evaluate current statements on dental amalgam. Materials and Methods. Two key-words “dental amalgam” and “toxicity” were used to search publications on dental amalgam biocompatibility published in peer-reviewed journals written in English. Manual search was also conducted. The most recent declarations and statements were evaluated using information available on the internet. Case reports were excluded from the study. Results. The literature show that mercury released from dental amalgam restorations does not contribute to systemic disease or systemic toxicological effects. No significant effects on the immune system have been demonstrated with the amounts of mercury released from dental amalgam restorations. Only very rarely have there been reported allergic reactions to mercury from amalgam restorations. No evidence supports a relationship between mercury released from dental amalgam and neurological diseases. Almost all of the declarations accessed by the internet stated by official organizations concluded that current data are not sufficient to relate various complaints and mercury release from dental amalgam. Conclusions. Available scientific data do not justify the discontinuation of amalgam use from dental practice or replacement with alternative restorative dental materials

Quantification of Plasma and Urine Thymidine and 2'-Deoxyuridine by LC-MS/MS for the Pharmacodynamic Evaluation of Erythrocyte Encapsulated Thymidine Phosphorylase in Patients with Mitochondrial Neurogastrointestinal Encephalomyopathy.

Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is an ultra-rare disorder caused by mutations in TYMP, leading to a deficiency in thymidine phosphorylase and a subsequent systemic accumulation of thymidine and 2'-deoxyuridine. Erythrocyte-encapsulated thymidine phosphorylase (EE-TP) is under clinical development as an enzyme replacement therapy for MNGIE. Bioanalytical methods were developed according to regulatory guidelines for the quantification of thymidine and 2'-deoxyuridine in plasma and urine using liquid chromatography-tandem mass spectrometry (LC-MS/MS) for supporting the pharmacodynamic evaluation of EE-TP. Samples were deproteinized with 5% perchloric acid (v/v) and the supernatants analyzed using a Hypercarb column (30 × 2.1 mm, 3 µm), with mobile phases of 0.1% formic acid in methanol and 0.1% formic acid in deionized water. Detection was conducted using an ion-spray interface running in positive mode. Isotopically labelled thymidine and 2'-deoxyuridine were used as internal standards. Calibration curves for both metabolites showed linearity (r > 0.99) in the concentration ranges of 10-10,000 ng/mL for plasma, and 1-50 µg/mL for urine, with method analytical performances within the acceptable criteria for quality control samples. The plasma method was successfully applied to the diagnosis of two patients with MNGIE and the quantification of plasma metabolites in three patients treated with EE-TP

A Symmetry Preserving Algorithm for Matrix Scaling

International audienceWe present an iterative algorithm which asymptotically scales the $\infty$-norm of each row and each column of a matrix to one. This scaling algorithm preserves symmetry of the original matrix and shows fast linear convergence with an asymptotic rate of $1/2$. We discuss extensions of the algorithm to the one-norm, and by inference to other norms. For the 1-norm case, we show again that convergence is linear, with the rate dependent on the spectrum of the scaled matrix. We demonstrate experimentally that the scaling algorithm improves the conditioning of the matrix and that it helps direct solvers by reducing the need for pivoting. In particular, for symmetric matrices the theoretical and experimental results highlight the potential of the proposed algorithm over existing alternatives.Nous décrivons un algorithme itératif qui, asymptotiquement, met une matrice à l'échelle de telle sorte que chaque ligne et chaque colonne est de taille 1 dans la norme infini. Cet algorithme préserve la symétrie. De plus, il converge assez rapidement avec un taux asymptotique de 1/2. Nous discutons la généralisation de l'algorithme à la norme 1 et, par inférence, à d'autres normes. Pour le cas de la norme 1, nous établissons que l'algorithme converge avec un taux linéaire. Nous démontrons expérimentalement que notre algorithme améliore le conditionnement de la matrice et qu'il aide les méthodes directes de résolution en réduisant le pivotage. Particulièrement pour des matrices symétriques, nos résultats théoriques et expérimentaux mettent en valeur l'intérêt de notre algorithme par rapport aux algorithmes existants

Canal wall reconstruction and mastoid obliteration with composite multi-fractured osteoperiosteal flap

We used inferior pedicled composite multi-fractured osteoperiosteal flap (CMOF), our original and new surgical approach, to obliterate the mastoid cavity and reconstruct the external auditory canal (EAC) to prevent the open cavity problems. CMOF was used to obliterate the mastoid cavity and reconstruct the EAC in 24 patients (13 women, 11 men; age span 12–51 years) who underwent radical mastoidectomy to treat the chronic otitis media between 1998 and 2004. Small meatoplasty was done in all 24 patients to relive their aesthetical concerns. Temporal bone CT scanning was done to observe the neo-osteogenesis in the mastoidectomy cavity and the CMOF, and the EAC volume was measured postoperatively. All our patients were followed-up for 2 years. The epithelization of the new EAC in our patients was complete at the end of the second month. Cholesteatoma, granulation, and recurrence of osteitis did not occur in any of the patients. We saw the new bone formation filling the mastoid cavity in the postoperative temporal bone CT scanning images. The mean volume of the new EAC on the 24th month was 1.83 ± 0.56 cm(3). We had an almost natural EAC, which owed its existence to the neo-osteogenesis that grows behind the CMOF, which we use to obliterate the mastoid cavity and to reconstruct the EAC

Deneysel meme kanseri modelinde süt proteinlerinin koruyucu etkisi

Amaç: Süt serumu proteinlerinin insan sağlığına üzerine birçok yararlı etkileri olduğu bilinmektedir. Çalışmamızda, sıçanlarda N-metil-N-nitrozure ile indüklenen meme kanseri modelinde süt serumu proteinlerinin koruyucu etkileri araştırılmıştır. Yöntemler: Çalışmamızda deneysel meme kanseri modeli oluşturmak üzere 130 günlük Sprague-Dawley türü, dişi, virjin sıçanlara 100 gün ara ile iki kez N-metil-N-nitrozüre enjekte edildi. Çalışma boyunca sıçanlara haftada iki kez orogastrik gavajla süt serumu proteinleri verildi. Sıçanlar 180 gün sonunda sakrifiye edildi doku örnekleri toplandı. Karaciğer, böbrek ve meme dokularındaki glutatyon, malondialdehit ve protein karbonil değerleri karşılaştırıldı. Bulgular: Tüm dokularda en yüksek malondialdehit ve protein karbonil değerleri N-metil-N-nitrozüre grubundaki sıçanlarda en düşük malondialdehit ve protein karbonil değerleri de kontrol grubunda gözlendi. N-metil-N-nitrozüre ile birlikte süt serumu proteinleri verildiğinde ise bu değerlerdeki artışların baskılanarak kontrol grubu değerlerine yaklaştığı gözlendi. Sonuç: Çalışmamızda N-metil-N-nitrozüre ile oluşturulan meme kanseri modelinde N-metil-N-nitrozüre etkisiyle oluşan biyokimyasal değişikliklere karşı süt serumu proteinlerinin koruyucu etkisi olduğu gözlenmiştir

Atrioventricular thrombus in a 14-year-old patient: a case report

Right atrioventricular thrombus was diagnosed by echocardiography in a 14-year-old boy. Thrombus was reached through the right ventricle to the pulmonary artery and it was caused to tricuspit valve insufficiency. Surgical thrombectomy was performed and, he was treated with oral anticoagulation in postoperative period