The purpose of the present study was to evaluate the effectiveness of Er:YAG laser scaling and the morphological and histological changes of the laser-scaled root surface in comparison with the effectiveness and root surface changes produced by conventional ultrasonic scaling. Fifty-three periodontally involved human extracted teeth with a band of subgingival calculus were used. The teeth were divided randomly into 2 groups for laser scaling and ultrasonic scaling. Laser irradiation was performed at an energy output of 40 mJ/pulse and 10 pulses/s under water spray, with the probe tip contacted obliquely to the root surface. Ultrasonic scaling was performed at a clinically standard power setting. The time required for scaling, the scaled area and the temperature changes were determined using both methods of treatment. The features of the scaled surfaces were examined by histological and scanning electron microscope (s.e.m.) observations. The Er:YAG laser provided subgingival calculus removal on a level equivalent to that provided by the ultrasonic scaler, without major thermal elevation. Macroscopically, the laser-treated root surface was somewhat rougher than or similar to the ultrasonically scaled root. However, the efficiency of the laser scaling was lower than that of the ultrasonic scaling. In addition, histological examination revealed a thin deeply stained zone on the lased root surface, and s.e.m. analysis revealed a characteristic microroughness on the lased surface. The laser scaling provided a level of calculus removal that was similar to that provided by the ultrasonic scaling. However, the Er:YAG laser produced superficial, structural and thermal microchanges on the root cementum.

Objective. To examine the entire HLA region for loci (other than the DRB1 locus) associated with rheumatoid arthritis (RA) susceptibility, by typing HLA-DRB1 alleles and multiple single-nucleotide polymorphisms (SNPs) in the Japanese population.Methods. The HLA-DRB1 alleles and 88 SNPs distributed over the HLA gene complex were genotyped, for 828 patients with RA and 1,032 control subjects. The data were evaluated for linkage disequilibrium, and case-control associations were analyzed in 2 ways, in the presence or absence of the disease-susceptibility DRB1 allele, to detect loci independent of the DRB1 allele.Results. HLA-DRB1 alleles *0405, *0401, *0901, *0101, *1401, *1602, *0403, and *1405 were significantly associated with RA in the Japanese population. The smallest P value (P ‫؍‬ 1.4 ؋ 10 ؊27 ) was observed in association with an intronic SNP of the NOTCH4 gene, which was due to strong linkage disequilibrium with the HLA-DRB1 allele. A strong association that was independent of HLA-DRB1 shared epitope alleles was observed in 2 SNPs: one in the intron of the MICA gene, the other in the intron of the HLA-DQB2 gene. Their association with RA, independent of HLA-DRB1 shared epitope alleles, was suggestive (P ‫؍‬ 0.0024 [corrected P (P corr ) ‫؍‬ 0.068, and P ‫؍‬ 0.00037 [P corr ‫؍‬ 0.012], respectively).Conclusion. These findings suggest that 1 or more other loci besides the HLA-DRB1 or other DRB1 (nonshared epitope, non-*0901) alleles are involved in RA susceptibility/protection.

The erbium:yttrium-aluminum-garnet (Er:YAG) laser is now increasingly used in periodontal therapy. The purpose of this study was to investigate the effect of Er:YAG laser irradiation on the morphology of periodontopathic bacteria and to compare the bacterial elimination effect of the laser and the ultrasonic scaler on diseased root surfaces in vitro. Colonies of Porphyromonas gingivalis were exposed to a single-pulse Er:YAG laser at 40 mJ and were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Also, 20 pairs of periodontally diseased root surfaces with subgingival calculi of freshly extracted teeth were treated by Er:YAG laser scaling at 40 mJ/pulse (14.2 J/cm(2) per pulse) and 10 Hz with water spray or ultrasonic scaling, or were not treated. The efficiency of each treatment was determined as the area treated per second, and the treated surfaces were examined by SEM. The material scraped from the treated root surfaces was cultured in aerobic and anaerobic conditions, and the numbers of colony forming units (CFUs) were compared. SEM and TEM showed that the Er:YAG laser had easily ablated the bacterial colony, leaving an ablation spot with a crater and the surrounding affected area showing melted branch-like structures. The laser irradiation was as equally effective and efficient as the ultrasonic scaler in performing root surface debridement. The CFUs after laser treatment were significantly fewer than those after ultrasonic scaling in aerobic and anaerobic culture conditions. Er:YAG laser ablates periodontopathic bacteria with thermal vaporization, and its bacterial elimination effect on the diseased root surfaces appears to be superior to that of the ultrasonic scaler.

Transforming growth factor (TGF)-beta1, a multifunctional cytokine, which regulates proliferation and differentiation of a variety of cell types, has the central role in the development and progression of renal injury in both animal models and human. Although it has been suggested that genetic variations in the TGF-beta1 gene are associated with the activity of the gene product, their clinical significance in glomerular disease is unknown. We investigated whether the polymorphisms of C-509T and T869C in TGF-beta1 account for interindividual variation in manifestations of IgA nephropathy (IgAN) using 626 Japanese subjects including 329 patients with histologically proven IgAN and 297 healthy controls with normal urinalysis. The frequencies of genotypes, alleles, and major haplotypes were similar between the patients and controls. The C-509T and T869C polymorphisms were in tight linkage disequilibrium, and the major haplotypes were C-C and T-T, which accounted for more than 95% of the total. In patients with -509CC and in those with the 869CC, urinary protein excretion was higher than in those with other genotypes, whereas no difference in other clinical manifestations was noted. Moreover, patients with -509CC and those with 869CC genotypes presented with a significant higher score of mesangial cell proliferation than in those with other genotypes. These results suggest that TGF-beta1 gene polymorphisms are specifically associated with heavy proteinuria and mesangial cell proliferation in Japanese patients with IgAN, although they do not confer susceptibility to this disease.

We report an elderly man with chronic tubulointerstitial nephritis (TIN) showing a high serum immunoglobulin G4 (IgG4) concentration. His serum creatinine (Scr) level had gradually increased from 0.9 mg/dL to 5.6 mg/dL over 18 months. Renal biopsy showed marked IgG4-positive plasma cell infiltration in the interstitium without glomerular abnormalities and IgG4-related TIN was diagnosed. Oral prednisolone reduced his Scr and IgG4 levels immediately. The present case indicates that IgG4-related TIN can not only progress rapidly but also chronically over a long period without significant urinary abnormalities, and we should consider hidden IgG4-related TIN in cases of chronic renal insufficiency.