A clinical and histological comparison of two different bone augmentation materials in the atrophic pre-maxilla.

This case study was conducted to compare the regenerative potential of bovine xenograft versus demineralized freeze-dried bone allograft in a thermoplastic biologic carrier in regards to achieving regeneration of bone width as well as potential bone height. The objective for the patient was to gain adequate bone volume for the placement of dental implants using the two different forms of graft material--one with a slow resorption time and the other in a gelatin matrix to provide dimensional stability. The results of this case report are inconclusive to demonstrate the superiority of one of the two graft materials over the other in reconstructing a severely atrophied maxilla. Both sites ultimately required a second guided bone regeneration (GBR) procedure prior to implant placement. It was speculated that adequate space maintenance might not have been achieved during the initial procedures.

Effect of nitisinone (NTBC) treatment on the clinical course of hepatorenal tyrosinemia in Québec.

BACKGROUND: Hepatorenal tyrosinemia (HT1, fumarylacetoacetate hydrolase deficiency, MIM 276700) can cause severe hepatic, renal and peripheral nerve damage. In Québec, HT1 is frequent and neonatal HT1 screening is practiced. Nitisinone (NTBC, Orfadin ®) inhibits tyrosine degradation prior to the formation of toxic metabolites like succinylacetone and has been offered to HT1 patients in Québec since 1994. METHODS: We recorded the clinical course of 78 Québec HT1 patients born between 1984 and 2004. There were three groups: those who never received nitisinone (28 patients), those who were first treated after 1 month of age (26 patients) and those treated before 1 month (24 patients). Retrospective chart review was performed for events before 1994, when nitisinone treatment began, and prospective data collection thereafter. FINDINGS: No hospitalizations for acute complications of HT1 occurred during 5731 months of nitisinone treatment, versus 184 during 1312 months without treatment (p<0.001). Liver transplantation was performed in 20 non-nitisinone-treated patients (71%) at a median age of 26 months, versus 7 late-treated patients (26%, p<0.001), and no early-treated patient (p<0.001). No early-treated patient has developed detectable liver disease after more than 5 years. Ten deaths occurred in non-nitisinone treated patients versus two in treated patients (p<0.01). Both of the latter deaths were from complications of transplantation unrelated to HT1. One probable nitisinone-related event occurred, transient corneal crystals with photophobia. INTERPRETATION: Nitisinone treatment abolishes the acute complications of HT1. Some patients with established liver disease before nitisinone treatment eventually require hepatic transplantation. Patients who receive nitisinone treatment before 1 month had no detectable liver disease after more than 5 years.

Newborn screening for hepatorenal tyrosinemia by tandem mass spectrometry: analysis of succinylacetone extracted from dried blood spots.

OBJECTIVES: To develop a method for the determination of succinylacetone (SA) in dried blood spots (DBS) using tandem mass spectrometry (MS/MS). METHODS: SA was extracted from DBS with an acetonitrile and water solution (80:20 by volume) containing formic acid and hydrazine hydrate (both at 0.1% by volume), and analyzed by MS/MS with a total run time per sample under 2 min. The reference range for SA in newborns was determined by analyzing a control group of 3199 DBS. SA was also measured in stored newborn specimens from three patients diagnosed clinically with hepatorenal tyrosinemia (HT). RESULTS: The within-run precision was