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Four patients with juvenile neuronal ceroid lipofuscinoses, a childhood neurodegenerative disorder that was previously described as CLN9 variant, are reclassified as CLN5 disease. CLN5-deficient (CLN5(-/-) ) fibroblasts demonstrate adhesion defects, increased growth, apoptosis, and decreased levels of ceramide, sphingomyelin, and glycosphingolipids. The CLN8 protein (CLN8p) corrects growth and apoptosis in CLN5(-/-) cells. Related proteins containing a Lag1 motif (CerS1/2/4/5/6) partially corrected these deficits, with CerS1, which is primarily expressed in brain, providing the best complementation, suggesting CLN5p activates CerS1 and may co-immunoprecipitate with it. CLN8p complements CLN5-deficient cells, consolidating the interrelationship of CLN5p/CLN8p, whose potential roles are explored as activators of (dihydro)ceramide synthases. Homozygosity mapping using microarray technology led to identification of CLN5 as the culprit gene in previously classified CLN9-defective cases. Similar to CLN5(-/-) cells, ceramide synthase activity, C16/C18:0/C24:0/C24:1 ceramide species, measured by MS is decreased in CLN8(-/-) cells. Comparison of normal versus CLN5(-/-) cell CerS1-bound proteins by immunoprecipitation, differential gel electrophoresis, and MS revealed absence of γ-actin in CLN5(-/-) cells. The γ-actin gene sequence is normal in CLN5(-/-) derived DNA. The γ-actin-bound proteins, vimentin and histones H2Afz/H3F3A/Hist1H4, were absent from the γ-actin protein complex in CLN5(-/-) cells. The function of CLN5p may require vimentin and the histone proteins to bind γ-actin. Defective binding could explain the CLN5(-/-) cellular phenotype. We explore the role of the CLN5/CLN8 proteins in ceramide species specific sphingolipid de novo synthesis, and suggest that CLN5/CLN8 proteins are more closely related than previously believed.

STATEMENT OF PROBLEM The use of resin patterns to produce partial coverage restorations is poorly documented. PURPOSE The purpose of this in vitro study was to compare the marginal and internal fit accuracy of lithium disilicate glass-ceramic inlays obtained from wax or resin patterns and fabricated with digital and conventional techniques. MATERIAL AND METHODS A dentoform mandibular first molar was prepared for a mesio-occlusal ceramic inlay. Six groups of 15 inlays were obtained by conventional impression and manual wax (group CICW) or resin patterns (group CICR); conventional impression, laboratory scanning of the stone die, CAD-CAM milled wax (group CIDW), or polymethylmethacrylate (PMMA) blocks (group CIDR); and scanning of the master preparation with an intraoral scanner, CAD-CAM milled wax (group DSDW), or PMMA blocks (DSDR). The same design was applied to produce the wax and PMMA patterns in the last 4 groups. The replica technique was used to measure marginal and internal fit under stereomicroscopy. Mixed-model ANOVA was applied to assess differences according to the techniques, materials, and discrepancy location (=.05). RESULTS The results demonstrated significant effects of the technique (P<.001), material (P=.009), and discrepancy location (P<.001) on fit measurements. Marginal discrepancy was only affected by the technique (P<.001), with the digital approaches yielding the smallest marginal discrepancy (23.5 ±3.6 m), followed by the conventional digital techniques (31.1 ±5.6 m) and finally by the conventional (42.8 ±7.2 m) techniques. Internal fit was significantly influenced only by the material with lower discrepancy in wax (75.2 ±9.0 m) than in resin patterns (84.7 ±15.1 m). The internal discrepancy was significantly larger than the marginal discrepancy in all groups (P<.001). CONCLUSIONS Inlays generated from conventional wax and resin patterns tend to show higher marginal discrepancies than conventional digital and full digital patterns. Wax and resin materials yield similar marginal fit accuracies irrespective of the impression/manufacturing technique. Better internal fit was shown in wax than in resin patterns, regardless of the technique.

SynopsisDifferential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and IR analysis were performed on a nonviscous epoxy polymer system (EP) with Kraft lignin (L) up to 20%.Mixtures of E P with similar amounts of silica (S) as in EP-L polyblends were used as a reference system for the analyses performed. EP-L polyblends cured a t room temperature exhibit a single TR, a fact characteristic for the monophasic systems. One-step tensile storage modulus vs. temperature curves, and related one-peak tensile loss modulus vs. temperature curves were found for all the EP-L polyblends. At about 30°C the tensile storage modulus of E P does not change in the presence of lignin in amounts up to 20% by weight. All these showed that L is miscible with E P and it does not affect the crosslinking at room temperature. IR spectra led to similar conclusions. The gradual decrease of the peak values of tan 6 with the amount of L in polyblends is due to an increase in the tensile storage modulus and a decrease of the tensile loss modulus a t temperatures close t o TR. This fact is explained by a stronger bond between E P and L, which could be formed at higher temperatures. The DSC and DMA data are in agreement with the mechanical properties of EP-L polyblends, which were reported previously.

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