Leakage of 4 resin-based root-canal sealers used with a single-cone technique.

OBJECTIVE: The aim of this study was to measure leakage of 4 resin-based sealers. STUDY DESIGN: Four groups of premolars (n = 60) were prepared using GT Rotary files and the crown-down technique and filled by the single-cone technique with AH26, AHPlus, EndoREZ, and an experimental MBP as sealer. Leakage was measured using the fluid filtration method after 15, 30, and 60 days and determined as microL/min(-1) x 10 psi. RESULTS: Statistical analysis by ANOVA and Tukey HSD test indicated that root fillings with AH Plus and the MBP showed lower leakage values after 15 days (P < .05). At 30 days, AH26 presented higher leakage values when compared to other sealers (P < .05). At 60 days, MBP and AH Plus presented the lower leakage values, differing significantly from EndoREZ (P < .05). CONCLUSION: It was observed that AH Plus and the experimental MBP showed lower leakage after 60 days than AH 26 and EndoREZ.     

The optimal procedure for the great arteries and left ventricular outflow tract obstruction. An anatomical study.

OBJECTIVE: To describe the optimal surgical strategy in heart specimens with transposition of the great arteries (TGA) and left ventricular outflow tract obstruction (LVOTO). METHODS: Thirty-three specimens with LVOTO were selected: TGA with intact ventricular septum (TGA/IVS) (10), TGA/VSD (21), and Taussig-Bing (2). RESULTS: LVOTO in TGA/IVS consisted of combinations of bicuspid pulmonary valve (four), subpulmonary fibrous ridge (four), obstructive muscular conus (two) and bulging muscular septum (four). Arterial switch operation (ASO) with LVOTO resection/valvotomy was feasible in nine hearts. Obstructive anterior papillary muscle prohibited LVOTO relief in one specimen. In TGA/VSD and Taussig-Bing LVOTO consisted of combinations of bicuspid (nine) or unicommissural (one) pulmonary valve, fibrous ridge (three), obstructive muscular conus (five), malaligned outlet septum (six), accessory mitral valve tissue (two), straddling mitral valve (two) and anterior mitral valve rotation (four). VSDs were subpulmonary in 13 (9 perimembranous, 4 muscular), subaortic in 3 (2 perimembranous, 1 anterior muscular), doubly committed in 2, inlet in 3 (2 perimembranous, 1 muscular), non-committed and anterior in 1, and finally 1 VSD extended both into inlet and subpulmonary outlet septum. LVOTO resection and ASO with VSD closure was possible in 10. In six specimens, both a Rastelli and a Nikaidoh operation were feasible. For two hearts, a Nikaidoh procedure was the only option, while Rastelli was considered optimal in another specimen. Mitral valve anomalies prevented LVOTO relief in four, only permitting for Senning/VSD closure (one) or univentricular palliation (three). CONCLUSIONS: LVOTO resection and pulmonary valvotomy frequently permits an ASO. Inlet VSD, impossibility of VSD enlargement, straddling mitral valve, distant aorta and small right ventricle make the Nikaidoh procedure the best option. Mitral anomalies preventing LVOTO relief can make biventricular repair impossible.     

A novel 37-Kd adhesive membrane protein from cloned murine bone marrow stromal cells and cloned murine hematopoietic progenitor cells

The adhesion of hematopoietic progenitor cells to bone marrow stromal cells is critical to hematopoiesis and involves multiple effector molecules. Stromal cell molecules that participate in this interaction were sought by analyzing the detergent-soluble membrane proteins of GBI/6 stromal cells that could be adsorbed by intact FDCP-1 progenitor cells. A single-chain protein from GBI/6 cells having an apparent molecular weight of 37 Kd was selectively adsorbed by FDCP-1 cells. This protein, designated p37, could be surface-radiolabeled and thus appeared to be exposed on the cell membrane. An apparently identical 37- Kd protein was expressed by three stromal cell lines, by Swiss 3T3 fibroblastic cells, and by FDCP-1 and FDCP-2 progenitor cells. p37 was selectively adsorbed from membrane lysates by a variety of murine hematopoietic cells, including erythrocytes, but not by human erythrocytes. Binding of p37 to cells was calcium-dependent, and was not affected by inhibitors of the hematopoietic homing receptor or the cell-binding or heparin-binding functions of fibronectin. It is proposed that p37 may be a novel adhesive molecule expressed on the surface of a variety of hematopoietic cells that could participate in both homotypic and heterotypic interactions of stromal and progenitor cells.     

Immunoglobulin M (IgM)-glycoinositolphospholipid enzyme-linked immunosorbent assay: an immunoenzymatic assay for discrimination between patients with acute toxoplasmosis and those with persistent parasite-specific IgM antibodies

In the present study we developed an enzyme-linked immunosorbent assay (ELISA) to measure immunoglobulin M (IgM) specific for glycoinositolphospholipids (GIPL) derived from tachyzoite membrane (IgM-GIPL ELISA). The sensitivity and specificity of the assay were compared with those of commercially available Toxoplasma-specific IgM serological tests, namely, immunofluorescence assay (IFA) with fixed tachyzoites and capture ELISA employing tachyzoite extracts. Our results show that all patients with acute toxoplasmosis, as determined by clinical data and conventional serological tests, were also positive by the IgM-GIPL ELISA. Interestingly, many patients that were classified as indeterminate, who had IgG with high avidity but positive results in the IgM-specific IFA and capture ELISA, were negative by the IgM-GIPL ELISA. Finally, we tested the sera from patients with rheumatoid arthritis and various parasitic infections and found no evidence of false positives in the IgM-GIPL ELISA.