Clinical success in regeneration: report of a case.

Occasionally in clinical periodontics we are confronted with exceptional examples of the potential for healing. This is the report of one such instance in a young patient with a history of juvenile periodontitis and significant localized bone loss. Following relatively simple treatment, marked bone fill of a periodontal defect was observed over the course of 1 year. The factors which contributed to the remarkable healing response are considered, and the techniques used during therapy are presented.

In vitro comparison of aged and young osteogenic and hemopoietic bone marrow stem cells and their derivative colonies.

The purpose of this in vitro study was to determine whether there were differences in the number and size of osteogenic and hemopoietic colonies derived from bone marrow stem cells of aged and young adult male Sprague-Dawley rats. Using a Ficoll-Paque gradient, stem cells were harvested from aged male rats 18 to 22 months old and young adult males 55 days of age. Single cell suspensions from the red marrow of the long bones were cultured 14 days in vitro and subsequent colonies were assessed by light microscopy for number and size. A computerized histomorphometric linear measuring system was utilized to assess colony area in square millimeters. The results clearly show that young animals have a statistically significant increased cellular potential for osteogenic and hemopoietic colony formation. Cultures from aged animals showed an average formation of 0.45 +/- 0.6863 osteogenic colonies while those from younger animals had an average of 3.6 +/- 2.3523 osteogenic colonies per 3 million cells plated. Hemopoietic colonies from aged animal cell cultures numbered 5.25 +/- 2.2449 while those from the young animals averaged 8.23 +/- 3.3601 per 3 million cells plated. The difference in size of the osteogenic and hemopoietic colonies between age groups was not statistically significant. The area of osteogenic colonies derived from aged animals measured 0.1244 +/- 0.0891 mm2, while those derived from the young animals averaged 0.1276 +/- 0.0518 mm2. Hemopoietic colonies from the aged cells measured 0.0759 +/- 0.0514 mm2, while hemopoietic colonies from the young animal cells measured 0.06010 +/- 0.0180 mm2. The results of this study may have implications for consideration in the cellular healing aspects of aged versus young individuals.

Antimotility and antisecretory activity of some aryl substituted amidinoureas.

A number of aryl substituted amidinoureas have been prepared and examined for their gastrointestinal spasmolytic, antimotility, antidiarrheal and antisecretory effects. In general, antisecretory and antimotility effects have been found to be associated with each other in these compounds. The structure-activity relationships found show that substitution of the aromatic ring in positions other than 2 and 6 correlates poorly with potency, and potency of such compounds is low. In contrast to this, 2,6-disubstitution confers high potency. The potency of 2,6-disubstituted compounds declines sharply with increasing weight of substitution of the amidinourea chain, with the important exception of the N-alkoxyamidinoureas. Increasing the molecular weight of an N-alkoxy substituent has a much less profound effect than the corresponding increase has in an N-alkyl substituent. High potency in an amidinourea may well be related to low basicity (or a high pKa value for its conjugate salt) but there is insufficient data to support this hypothesis fully. The actual tautomeric structure of an amidinourea probably affects its potency and this is discussed briefly.