Fate of bone marrow mesenchymal stem cells following the allogeneic transplantation of cartilaginous aggregates into osteochondral defects of rabbits

The purpose of this study was to track mesenchymal stem cells (MSCs) labelled with internalizing quantum dots (i‐QDs) in the reparative tissues, following the allogeneic transplantation of three‐dimensional (3D) cartilaginous aggregates into the osteochondral defects of rabbits. QDs were conjugated with a unique internalizing antibody against a heat shock protein‐70 (hsp70) family stress chaperone, mortalin, which is upregulated and expressed on the surface of dividing cells. The i‐QDs were added to the culture medium for 24 h. Scaffold‐free cartilaginous aggregates formed from i‐QD‐labelled MSCs (i‐MSCs), using a 3D culture system with chondrogenic supplements for 1 week, were transplanted into osteochondral defects of rabbits. At 4, 8 and 26 weeks after the transplantation, the reparative tissues were evaluated macroscopically, histologically and fluoroscopically. At as early as 4 weeks, the defects were covered with a white tissue resembling articular cartilage. In histological appearance, the reparative tissues resembled hyaline cartilage on safranin‐O staining throughout the 26 weeks. In the deeper portion, subchondral bone and bone marrow were well remodelled. On fluoroscopic evaluation, QDs were tracked mainly in bone marrow stromata, with some signals detected in cartilage and the subchondral bone layer. We showed that the labelling of rabbit MSCs with anti‐mortalin antibody‐conjugated i‐QDs is a tolerable procedure and provides a stable fluorescence signal during the cartilage repair process for up to 26 weeks after transplantation. The results suggest that i‐MSCs did not inhibit, and indeed contributed to, the regeneration of osteochondral defects. Copyright © 2010 John Wiley & Sons, Ltd.     

Effect of canal taper and plugger size on warm gutta-percha obturation of lateral depressions

This study used transparent epoxy-resin root canal models to evaluate different main root canal tapers and various methods of vertical compaction for warm gutta-percha obturation of lateral depressions. The root canal models had straight main root canals with three tapers and four lateral depressions at right angles to the main root canal, 1.0 mm and 3.0 mm from the apex. Three types of experimental stainless steel pluggers with different flat-tip diameters and tapers were used to compact the warm gutta-percha. The Obtura II was used for obturation. After obturation, the depth of penetration into lateral depressions was measured under a stereoscopic microscope, and the effects of root canal taper and plugger size were analyzed by using two-way analysis of variance. The penetration of warm gutta-percha into lateral depressions using the smallest-diameter plugger decreased with increasing main root canal taper. Penetration into lateral depressions increased with the use of pluggers of the correct size. There was a close relationship between plugger size and canal taper. The results suggest that main root canal taper and plugger size should be closely matched so as to promote gutta-percha obturation of lateral depressions.     

Topical treatment of oral cavity and wounded skin with a new disinfection system utilizing photolysis of hydrogen peroxide in rats

The present study aimed to evaluate the acute locally injurious property of hydroxyl radical generation system by photolysis of H(2)O(2), which is a new disinfection system for the treatment of periodontitis developed in our laboratory. Firstly, generation of the hydroxyl radical by a test device utilizing the photolysis of H(2)O(2) was confirmed by applying an electron spin resonance (ESR)-spin trapping technique. Secondly, the bactericidal effect of the device was examined under a simulant condition in which Staphylococcus aureus suspended in 1 M H(2)O(2) was irradiated with laser light emitted from the test device, resulting in substantial reduction of the colony forming unit of the bacteria within a short time as 2 min. Finally, acute topical effect of the disinfection system on rat oral mucosa and wounded skin was evaluated by histological examination. No abnormal findings were observed in the buccal mucosal region treated three times with 1 M H(2)O(2) and irradiation. Similarly, no abnormal findings were observed during the healing of skin treated with 1 M H(2)O(2) and irradiation immediately after wounding. Since topical treatment with the novel disinfection technique utilizing the photolysis of H(2)O(2) had no detrimental effect on the oral mucosa and the healing of full thickness skin wounds in rats, it is expected that the acute locally injurious property of the disinfection technique is low.     

Antiretroviral therapy for treatment-naïve chronic HIV-1 infection with an axonal variant of Guillain-Barré syndrome positive for anti-ganglioside antibody: a case report

Guillain-Barré syndrome sometimes manifests as immune reconstitution inflammatory syndrome. We report a treatment-na?ve male with chronic HIV-1 infection who presented with an axonal variant of Guillain-Barré syndrome. Antiretroviral therapy commenced one month later and no rapid improvement or deterioration of tetraparesis was noted. This is the first report that describes the detection and serial measurements of anti-ganglioside antibody in a patient with HIV infection. This case suggests a limited role for T-cell immunity in the production of anti-ganglioside antibody and the pathogenesis of axonal variants, since the antiretroviral therapy-induced improvement in T-cell immunity neither re-elevated anti-ganglioside antibody titer nor worsened tetraparesis.     

GATA3 abnormalities in six patients with HDR syndrome

GATA3 mutations cause HDR (hypoparathyroidism, sensorineural deafness, and renal dysplasia) syndrome and, consistent with the presence of the second DiGeorge syndrome locus (DGS2) proximal to GATA3, distal 10p deletions often leads to HDR and DiGeorge syndromes. Here, we report on six Japanese patients with GATA3 abnormalities. Cases 1-5 had a normal karyotype, and case 6 had a 46,XX,del(10)(p15) karyotype. Cases 1-6 had two or three of the HDR triad features. Case 6 had no DiGeorge syndrome phenotype except for hypoparathyroidism common to HDR and DiGeorge syndromes. Mutation analysis showed heterozygous GATA3 mutations in cases 1-5, i.e., c.404-405insC (p.P135fsX303) in case 1, c.700T>C & c.708-709insC (p.F234L & p.S237fsX303) on the same allele in case 2, c.737-738insG (p.G246fsX303) in case 3, c.824G>T (p.W275L) in case 4, and IVS5+1G>C (splice error) in case 5. Deletion analysis of chromosome 10p revealed loss of GATA3 and preservation of D10S547 in case 6. The results are consistent with the previous finding that GATA3 mutations are usually identified in patients with two or three of the HDR triad features, and provide supportive data for the mapping of DGS2 in the region proximal to D10S547.     

Vascular endothelial growth factor-C and its receptor type-3 expressed in acute lymphocytic leukemia cases with t(1;19)

The vascular endothelial growth factor (VEGF)-C system was analyzed in two cases of acute lymphocytic leukemia (ALL) with TCF3/PBX1 fusion to determine whether the VEGF-C system influences the growth of these ALL blasts. Bone marrow non-adherent mononuclear cells were prepared from the patients, and expressions of VEGFs and VEGF receptors (VEGFRs) were analyzed based on RNA and protein levels. Cell proliferation was also assayed with or without neutralizing antibodies to VEGFs. The patients’ leukemic blasts expressed a significant amount of VEGF-C and VEGFR type-3. When anti-VEGF-C antibody was added to the blast cell cultures, cell proliferation was suppressed. These observations indicate that, in our ALL cases with TCF3/PBX1 fusion, VEGF-C autocrine stimulation plays an important role in the proliferation of ALL.