RESUMEN
<i>Background:</i> Enamel matrix derivative placed in the backs of rats induces numerous eosinophilic round bodies (ERBs) and hard tissue. ERBs were analyzed by matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and by database analysis. Subsequently, a seven-amino-acid sequence was identified, and an artificial oligopeptide was synthesized with its sequence. The present experiment was carried out to clarify whether or not the peptide induces hard tissue formation <i>in vivo</i>.<i>Methods:</i> Synthetic oligopeptide was injected into the backs of 15 rats. After injection, the tissues were excised at various times and prepared for light and immune-light microscopy.<i>Results:</i> A white lump was macroscopically observed in each rat back 14 days after injection of 7.5 and 15 mg/mL synthetic oligopeptide, and endochondral ossification and bone formation were microscopically observed in one rat back 14 days after injection of 15 mg/mL synthetic oligopeptide.<i>Conclusions:</i> The synthetic oligopeptide is pure, 1,118 dalton, and apparently low-toxicity. It seems to produce hard tissues, such as cartilage and bone tissue.
RESUMEN
A 27-peptide,a fragment of hepatitis delta antigen(HDAg),was synthesized and used to develop an ELISA method for ihe detection of anti-HD.It was found that positive anti-HD reaction occurred between the coated 27-peptide and a stored sample of serum which was known anti-HD positive.Absorption test revealed that the synthetic peptide competed with natural HDAg for anti-HD,suggesting that the peptide possessed the antigenicity similar to that of natural HDAg.The antigenicity of the synthetic peptide was quite specific wihtout cross reaction with normal human and mouse sera and with anti-HA.anti-HB and anti-HC sera.Among 300 blood donors,there was only 1 case(0.33%)anti-HD positive with an ALT level 2 times higher than normal.In 41 cases of non-B hepatitis and 52 cases of HAV hepatitis,none was anti-HD positive.In 211 cases of various types of HBV hepatitis,21 were(9.95%)anti-HD positive,among whom 2/82(2.5%)werehealthy HBV carriers,6/43(13.95%)were patients with a-cute icteric hepatitis,6/60(10.00%)were patients of chronic active hepatitis,4/18(22.20%)were patients of severe hepatitis,and 3/8(37.50%)were those with liver cirrhosis.These results were consistent with those in our previous reports.