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G Keller

Publications and source records attributed to G Keller.

172 records · Page 10Linked to original sources
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Retrovirus transfer of a bacterial gene into mouse haematopoietic progenitor cells.

The haematopoietic system is made up of a hierarchy of cells with different developmental, functional and proliferative capacities. Although cellular diversity appears to arise from the commitment and maturation of stem cells, the molecular basis for this differentiation process is unknown. The introduction of cloned DNA sequences into haematopoietic progenitor cells would provide a novel approach for studying this differentiating in vivo system. One laboratory has reported DNA-mediated transfer of genes into mouse bone marrow cells. However, retroviruses offer a number of advantages over DNA-mediated gene transfer procedures, including high efficiency infection of a wide range of cell types in vitro and in vivo, stable and low copy integration into the host chromosome, and a defined integrated provirus structure. For these reasons recombinant DNA techniques have been utilized to construct high efficiency retrovirus vectors expressing foreign genes. We demonstrate here, using such a retrovirus vector, the transfer of a dominant selectable drug-resistance gene into defined classes of mouse haematopoietic progenitor cells. These observations should facilitate the development of molecular genetic approaches to fundamental and clinical problems in haematopoiesis.

Animals↗
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Expression of a foreign gene in myeloid and lymphoid cells derived from multipotent haematopoietic precursors.

Bone marrow cells infected with retroviral vectors carrying the bacterial neomycin resistance (neo) gene as a marker were used for long-term reconstitution of the haematopoietic system of irradiated mice. The neo gene is expressed in the myeloid and lymphoid lineages of these animals and an analysis of the sites of viral integration indicates that these lineages are derived from the same primitive multipotent cells.

Animals↗
PubMedDate not supplied

[Significance of subsequent hip unloading after surgical intertrochanteric osteotomy of idiopathic femur head necrosis].

PURPOSE: To judge the influence of consequent non-weight-bearing on the postoperative results, we reviewed 28 patients in whom we performed intertrochanteric osteotomies for idiopathic osteonecrosis of the femoral head during the years 1996 and 1997. Postoperatively 12 patients were supplied with a walking device for non-weight-bearing which was used for 1 year. 16 patients were mobilized by using 2 crutches for 15 kp partial weight-bearing until the osteotomy healed up and were then allowed to bear full weight. METHOD: For clinical evaluation of the early results after about 18 month the Merle d'Aubigné hip score was used. Furthermore we analyzed pelvic radiographs for assessing the stage of the necrosis (Ficat staging) and the necrotic angle. RESULTS: Overall 82% good and excellent results were achieved. Due to a longer period of non-weight-bearing the results were again clearly improved (92% versus 75% of patients with partial weight-bearing). It was noticed that there were discrepancies between good clinical results and the less satisfying radiographic findings. CONCLUSIONS: Postoperative non-weight-bearing for about 1 year with the use of a walking device by patients with idiopathic osteonecrosis of the femoral head has clearly a positive effect on clinical results.

Adult↗