Synthesis of osteogenic growth peptide and its synergetic effect with granulocyte colony stimulating factor.

Osteogenic growth peptide (OGP) has been synthesized through Fmoc solid phase synthesis procedure. The purity of synthetic OGP (sOGP) is over 98.6% identified by HPLC, the amino acid sequence and electro-spray mass spectroscopy are consistent with theoretical values. The synergetic effect of sOGP with recombinant human granulocyte-colony stimulating factor (rhG-CSF) on the hematopoiesis was investigated in normal mice. To assess the synergy of sOGP with rhG-CSF, two schemes were designed. In one scheme rhG-CSF was used at the last 8 days of a 13-day treatment with sOGP, while in the other one both cytokines were given concurrently for 10 days [sOGP, 0.5 nmol/day (mouse); rhG-CSF, 2 microg/day (mouse)]. Both schemes showed that sOGP remarkably synergized with rhG-CSF on increment of white blood cell number and lymphocyte number in peripheral blood without any change of red blood cell and platelet counts. Quantitative differential analysis of bone marrow and histological examination of the spleen and sternum showed that sOGP plus rhG-CSF did not cause abnormal hyperplasia, so sOGP is a very hopeful new drug to improve the effectiveness of clinical used rhG-CSF.

Effect of cryopreservation on patency and histological changes of arterial isogeneic and allogeneic grafts in the rat model.

Vascular grafting is used frequently in the management of length discrepancies between blood vessels. Cryopreservation permits vascular graft storage and aids availability; however, long-term patency of cryopreserved arterial allografts is not well established. Fifty Fisher and 55 Wistar rats were used in the study. Thirty-eight cryopreserved Fisher femoral arterial grafts were transplanted into the femoral arteries of 15 Fisher (cryoisografts) and 23 Wistar rats (cryoallografts). Thirty-two fresh Fisher arterial grafts were implanted into 32 Wistar femoral arteries (fresh allografts). The animals were killed at 1, 4, and 8 months in each group, and graft patency was assessed. One-month graft patency was 100% in all groups. At 4 months, graft patencies were 86%, 100%, and 75% in the cryoisografts, cryoallografts, and fresh allografts respectively. All cryoisografts and fresh allografts were patent, whereas all the cryoallografts were occluded at 8 months ( < 0.01). Cryopreserved rat arterial allografts offered satisfactory graft patency up to 4 months after implantation and may therefore be applicable clinically in selected cases.