Henrik Wie

Effects of Cyclophosphamide on Mechanical Properties of Bone and Skin in Rats

The effects of several different doses of cyclophosphamide on weight increase, longitudinal bone growth and mechanical properties of bone, intact skin and skin wounds, were studied in 30 young, male rats. The cystostatic effect was evaluated by counting white blood cells (WBC) in arterial blood at the end of the medication period. Compared with the control animals, the longitudinal bond growth, the mechanical properties of the distal femoral metaphysis and the skin wounds were most noticeably affected by the drug. Diaphyseal torsional strength of the femoral bone and tensile strength of intact skin were less affected.

Mechanical Properties of Bone and Skin During Recovery after Cyclophosphamide Administration

SummaryThe effects of cyclophosphamide were studied 2, 5 and 9 days after terminating a two-week every-second-day intraperitoneal medication in young, male rats. The cytostatic effect was assessed by counting white blood cells (WBC) in arterial blood.WBC counts were reduced by 72% of control values at 2 days and regained normal values at 9 days after an overshooting leucocytosis at 5 days.Compared to control animals, the treated rats had significantly reduced body weights, metaphyseal bending strength and longitudinal growth of the femur at all time intervals observed. The torsional strength of the femur diaphysis and the strength of wounded skin were not affected at 2 days, but significantly reduced at 5 and 9 days. The tensile strength of intact skin was not found to be affected by the drug.From the 5th to the 9th day after ending medication, the curves for control and treated animals were assuming parallel slopes regarding metaphyseal bone strength, longitudinal bone growth and tensile strength of wounds. This may indicate reversion of the drug effects approximately one week after terminating medication.ZusammenfassungDie Auswirkungen von Cyclophosphamid wurden bei jungen männlichen Ratten untersucht, 2, 5 und 9 Tage nach Beendigung einer zweiwöchigen Verabreichung, die alle 2 Tage intraperitoneal erfolgte. Die cytostatische Wirkung wurde durch die Leukozytenzählung im arteriellen Blut bestimmt.Die Leukozytenwerte waren am zweiten Tage um 72% reduziert und erreichten wieder eine normale Höhe am 9. Tag nach einer überschießenden Leukozytose am 5. Tag.Verglichen mit Kontrolltieren hatten die behandelten Ratten ein signifikant reduziertes Körpergewicht, eine herabgesetzte Biegefestigkeit der Metaphysen und ein verringertes Längenwachstum des Femur. Die Torsionsfestigkeit der Femurdiaphyse und die Festigkeit der verletzten Haut waren nach 2 Tagen nicht verändert, aber nach 5 und 9 Tagen signifikant herabgesetzt. Die Dehnungsfestigkeit der unverletzten Haut zeigte keine Verānderung durch das Medikament.Vom 5. bis zum 9. Tag nach Absetzen der Medikation zeigten die Kurven der Kontrollgruppe und der behandelten Tiere parallele Verläufe bezüglich der metaphysären Knochenfestigkeit, des Knochenlängenwachstums und der Zugfestigkeit der Hautwunden. Dies kann als Hinweis dafür gewertet werden, daß die Auswirkungen des Medikamentes sich etwa 1 Woche nach Beendigung der Verabreichung zurückbilden.

Implant-tissue interface of endosseous dental implants in dogs. validity of clinical evaluation methods.

Plaque and gingival bleeding were scored and probing, radiography, and histologic methods were used to evaluate clinical methods for estimating alterations of supporting structures at functioning endosseous dental implants. Twelve implant abutment posts in three Labrador retriever dogs were assessed. The observation period was 3 months of submerged healing followed by 6 months in function. In the presence of daily gingival cleaning, both plaque and gingival bleeding scores were reduced on implant abutments. No correlation was found between gingival scores and the degree of bone resorption. The correlation between probing and radiographic measurements was studied by comparing 136 parallel measurements. The average difference was 0.4 mm. Discrepancies were observed when evaluating bone loss that reached the shoulder area. Better accordance was obtained when moderate (2 to 4 mm) or extensive (6 to 8 mm) resorption was assessed. Histologic evaluation indicated alternating regions of implant-bone contact and fibrous encapsulation. Progressive infiltrates were observed in the permucosal area, sometimes extending into the deeper parts of the supporting bone. A combination of probing and radiographic measurements seems to give the most reliable information about the level of bone support and is recommended to be included in routine control of implant abutments.