Progression of transthyretin (TTR) amyloidosis in donors and recipients after domino liver transplantation-a prospective single-center cohort study.

Liver transplantation (LT) is the first-line therapy in patients with transthyretin (TTR) amyloidosis and progressive familial amyloid polyneuropathy (FAP). Explanted organs from these patients can be used for domino liver transplantation (DLT). After DLT, de novo amyloidosis may develop in domino recipients (DR). Data were collected prospectively in a transplant database. Electroneurography by nerve conduction velocity (NCV), quantitative sensory testing, heart rate variability (HRV), sympathetic skin response, orthostatic reaction (tilt table test), transthoracic echocardiography, cardiac MRI and organ biopsy results were evaluated. The cohort included 24 FAP- (11 Val30Met, 13 nonVal30Met) and 23 DR-patients. DR symptoms referred to post-DLT only, while those of FAP patients were both pre- and post-transplantation. Symptoms of TTR-amyloidosis in Val30Met and Non-Val30Met patients pre- and post-LT were similarly distributed. Biopsy-proven de novo amyloidosis occurred in 4/23 DR after a mean observation of 10 years. Analysis for manifestations of amyloidosis only included patients with available 5-year follow-up data (n = 13 FAP, n = 12 DR). Compared to Val30Met FAP patients pre-LT, Val30Met DR patients had better NCV (P = 0.04) and HRV (P = 0.015). In the Non-Val30Met group no differences were found between DR and FAP patients pre-LT. TTR-amyloidosis symptoms showed no differences in FAP patients pre- and 5 years post-LT, irrespective of Val30Met status. In DR patients, de novo amyloidosis occurred earlier than expected. Therefore, recipients for DLT need to be carefully selected and followed.

Penetration Potential of a Silver Diamine Fluoride Solution on Dentin Surfaces. An Ex Vivo Study.

BACKGROUND: Occurrence of open dentinal tubules as a cause of dental hypersensitivity is a very common pnenomenon in patients. The aim of this in vitro study was to assess the effect of a silver diamine fluoride solution (Ag(NH3)2 F) on human dentin samples. METHODS: A total of five fully retained wisdom teeth were selected for this study. The crowns of the teeth were separated from the roots and the occlusal enamel surface was removed. All dentin samples were treated for 60 seconds with phosphoric acid (36%) and rinsed thoroughly to remove the smear layer. Then the desensitizing agent (Riva Star, SDI; 38% Ag(NH3)2 F) was placed according to the manufacturer's instruction. Three dentin samples were prepared for element analysis using an electron beam microprobe analyzer (JEOL JXA 8900RL). The Ag concentrations in the dentin samples were measured in depths ranging from 5 to 40 µm. The other two dentin samples were vertically fractured and accordingly prepared for visualization with SEM (Zeiss DSM). RESULTS: The application of the desensitizing agent on the dentin areas demonstrated an increased Ag concentration (JEOL JXA 8900RL). On the dentin surface an Ag concentration of 1.7 weight % (? 0.7) was measured, but at a depth of 20 µm only 0.3 weight % (± 0.1) were detected. In depths greater than 40 µm the Ag concentration was below the detection limit. The SEM results showed that deposits could be found in a covering on the dentin layer and in the dentinal tubules to a depth of 20 µm. CONCLUSIONS: In this ex vivo study, the effect of silver diamine fluoride on dentin surfaces could be demonstrated. The desensitizing agent formed a film on the dentin surface and in some dentinal tubules deposits were detected. These findings can explain a certain desensitizing effect, but a direct translation to in vivo conditions can only be done with caution.