Ultrathin CAD-CAM Ceramic Occlusal Veneers and Anterior Bilaminar Veneers for the Treatment of Moderate Dental Biocorrosion: A 1.5-Year Follow-Up.

Dental biocorrosion can produce a devastating impact on oral health. The restorative phase of the treatment should not cause additional damage of the remaining sound tooth structure. Ultrathin occlusal veneers are a conservative alternative to traditional onlays and complete crowns for the treatment of severe biocorrosive lesions. This strategy is explained in the present case report through a full-mouth rehabilitation of a patient with moderate biocorrosion. Maxillary anterior teeth were restored using the bilaminar technique (lingual direct composite veneers with labial ceramic veneers) and posterior teeth using ultrathin CAD-CAM ceramic occlusal veneers. The technical aspects required for the implementation of this new restorative design are presented with a special emphasis on the control of tooth preparation based on diagnostic wax-up, provisionalization, and the use of CAD-CAM technology.

AAV-based gene therapy prevents neuropathology and results in normal cognitive development in the hyperargininemic mouse.

Complete arginase I deficiency is the least severe urea cycle disorder, characterized by hyperargininemia and infrequent episodes of hyperammonemia. Patients suffer from neurological impairment with cortical and pyramidal tract deterioration, spasticity, loss of ambulation and seizures, and is associated with intellectual disability. In mice, onset is heralded by weight loss beginning around day 15; gait instability follows progressing to inability to stand and development of tail tremor with seizure-like activity and death. Here we report that hyperargininemic mice treated neonatally with an adeno-associated virus (AAV)-expressing arginase and followed long-term lack any presentation consistent with brain dysfunction. Behavioral and histopathological evaluation demonstrated that treated mice are indistinguishable from littermates, and that putative compounds associated with neurotoxicity are diminished. In addition, treatment results in near complete resolution of metabolic abnormalities early in life; however, there is the development of some derangement later with decline in transgene expression. Ammonium challenging revealed that treated mice are affected by exogenous loading much greater than littermates. These results demonstrate that AAV-based therapy for hyperargininemia is effective and prevents development of neurological abnormalities and cognitive dysfunction in a mouse model of hyperargininemia; however, nitrogen challenging reveals that these mice remain impaired in the handling of waste nitrogen.

Antiapoptotic properties of erythropoietin: novel strategies for protection of retinal pigment epithelial cells.

INTRODUCTION: Oxidative damage of the retinal pigment epithelium (RPE) may play a role in the development and progression of age-related macula degeneration (ARMD). Therapeutic reduction of oxidative stress failed or had only slight effects in ARMD patients. This study evaluates antiapoptotic properties of erythropoietin (epo) at the RPE as a novel approach to protect RPE cells against oxidative damage. MATERIALS AND METHODS: Cultured ARPE-19 cells were exposed to hydroxyl (OH) radicals generated from H(2)O(2) under catalysis of Fe(3+) (Fenton reaction) for 5 min. Apoptosis rate was determined by Annexin V labelling and terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling assay. Epo was added in concentrations from 0 to 100 U/ml to the media 24 and 1 h before radical exposure as well as shortly after radical exposure. Expression of epo receptor was determined by western blotting. RESULTS: Hydroxyl radical exposure induced an increase of apoptosis rate from virtually 0 to 11.8+/-1.7%. Apoptosis was detectable up to 24 h after radical exposure and reached its maximum after 6 h. Epo reduced apoptosis rate by up to 88% even if applied after the radical exposure. Best protection was achieved at 5 U/ml epo. Western blot confirmed presence of epo receptor independent of a pre-incubation of the cells with epo. DISCUSSION: Epo exerts antiapoptotic effects on cultured RPE cells even if applied after the radical exposure. This might qualify epo as future candidate for therapy and prevention of dry ARMD.

Longitudinal evaluation of transport kinetics in children receiving peritoneal dialysis.

Functional stability of the peritoneal membrane is necessary for maintenance of peritoneal dialysis (PD) as a therapeutic option. Few studies have investigated this issue in children. We evaluated the peritoneal membrane solute transport capacity longitudinally in 26 children (mean age 11.0+/-5.5 years) receiving long-term PD. Each patient underwent a standardized peritoneal equilibration test on two occasions (mean interval between studies 19.8+/-5.9 months) to determine solute dialysate to plasma (D/P) ratios, dialysate glucose to initial dialysate glucose (D/D(0)) ratios, and mass transfer area coefficients (MTAC). The correlation of transport capacity with peritonitis history was also assessed. No significant change in MTAC, D/P, or D/D(0) values were found when comparing original and follow-up data of the group overall. However, transport of creatinine and glucose was significantly (P<0.05) greater in the peritonitis group compared with the group without peritonitis, and differences in the change over time between the peritonitis groups was significant for MTAC creatinine (P=0.035) and D/D(0) glucose (P=0.020). In summary, this experience demonstrates functional stability of the peritoneal membrane in pediatric patients receiving PD. However, follow-up assessments of peritoneal solute kinetics may be necessary in patients with a history of peritonitis in order to permit early identification of those who may be at risk for ultrafiltration failure and sclerosing peritonitis.

Adverse effect of peritonitis on peritoneal membrane function in children on dialysis.

The effect of peritonitis on peritoneal membrane solute transport characteristics was determined as part of a multicenter study in children on continuous ambulatory/cycling peritoneal dialysis. Ninety-three children each underwent a 4-h peritoneal equilibration test (PET) with 1,100 ml/m2 2.5% Dianeal for determination of mass transfer area coefficients (MTAC), dialysate to plasma ratios (D/P) for creatinine and urea at 0, 30, 60, 120, 180, and 240 min and dialysate glucose levels at 0, 30, 60, 120, 180, and 240 min for calculation of D/Do. The mean age of the study cohort was 10.1 +/- 5.6 years (range 0.1-19 years). There were 162 historical episodes of peritonitis; at the time of the PET tests, 36 children had never had an episode of peritonitis (group I) while 57 children had a history of one or more episodes of peritonitis (group II). In group II children, the 4-h glucose D/Do was significantly lower and the 4-h D/P creatinine ratio, the creatinine MTAC, and the glucose MTAC were significantly higher (each P < 0.05) than in group I. In children with a history of peritonitis caused by Gram-negative organisms, the 4-h glucose D/Do (P < 0.05) and the creatinine MTAC (P < 0.05) were significantly lower and the glucose MTAC (P = 0.07) nearly significantly lower than in children without a history of peritonitis. Linear regression analysis did not demonstrate a correlation between any of the variables and duration of peritoneal dialysis, while the rate of peritonitis was weakly correlated with glucose MTAC (r = 0.34, P < 0.05) and with 4-h glucose D/Do (r = -0.222, P < 0.01). We conclude that children with a history of peritonitis have peritoneal membranes that are more permeable to glucose and creatinine than children without a history of peritonitis, and that the peritoneal membranes of children who have had peritonitis caused by Gram-negative organisms are also more permeable to creatinine and glucose. Such changes are likely to have an adverse effect on membrane function and could eventually contribute to ultrafiltration failure.

Effects of chlorinated solvents on the natural lymphocytotoxic activities of human liver immune cells.

Inhibition of the natural immune system may be involved in the liver cancer caused by some non-genotoxic chemicals when they are administered at high doses to certain strains of animals. Previous studies have shown that some chlorinated solvents inhibit liver natural immune function in rodents. In this preliminary study, the effects of in vitro exposure to three commonly used chlorinated solvents were determined on three tumoricidal activities expressed by isolated human liver immune cells-natural killer (NK), natural cytotoxic (NC) and natural P815 killer (NPK) (Wright and Stacey, 1991) cell activities. The NK, NC and NPK cell activities of immune cells isolated from three human livers were 115, 45 and 53 lytic units (LU(20%)/10(6) effector cells), respectively. In vitro exposure to trichloroethylene (TRI) inhibited all three natural immune activities, and the ranking of sensitivity was NPK NC NK. Tetrachloroethylene (TET) inhibited NC and NPK cell activities, but had little effect on NK cell activity. 1,1,1-Trichloroethane (TCE) had little or no effect on the three tumoricidal activities examined. Overall, these data show clear similarities to the results obtained in vitro using cells from experimental animals.

Effects of tetrachloroethylene on hepatic and splenic lymphocytotoxic activities in rodents.

The industrial solvent tetrachloroethylene (TCE) is a liver carcinogen in experimental animals but is without significant genotoxicity. Presumably some nongenotoxic mechanism accounts for its cancer-causing effects. We have therefore investigated the effects of TCE on splenic and hepatic lymphocytotoxic activities in Sprague-Dawley rats and B6C3F1 mice, following in vivo and in vitro exposure to TCE. Natural killer (NK), natural cytotoxic, and "natural P815 killer" activities were measured in liver- and spleen-derived immune cells. Humoral and T-cell mitogenesis were assayed in lipopolysaccharide and Con-A-stimulated splenic cells, respectively. TCE administration in vivo did not significantly alter the various immunological parameters assessed, while in vitro exposure to TCE inhibited natural cytotoxic activity from liver and spleen in mice and rats. NK and "natural P815 killer" activity in rat cells exposed in vitro to TCE were also inhibited. Thus, TCE is capable of directly inhibiting natural lymphocytotoxic activity, which is indicated by these in vitro effects. While an inhibitory effect was not observed when immune cells were isolated from in vivo treated animals, the in vitro data do support the possibility that a direct inhibition of natural immune function may play some role in the carcinogenic effects of TCE in experimental mice.