[Treatment of fractures of the distal part of the forearm using external fixation]. / Lécení zlomenin distální cásti predloktí zevní fixací.

In the years 1986-1987 the authors operated on 14 patients with 15 fractures in the area of the distal part of the forearm. They performed external fixation in open fractures and in unstable, intra-articular and extra-articular closed fractures. They use Poldi 7 external fixation device, the clamp type of fixation with the insertion of 2 screws into the radius and 2 screws into the second metacarpal. Reduction is carried out by distraction using the principle of ligamentotaxy. The evaluation of the results in the period between' 8-22 months after the operation showed excellent clinical results in 6 patients, good results in 7 patients and a fair result in one elderly female patient where a sizable radionulnar synostosis occurred during healing. Subjective feelings evaluated ten times as excellent and four times as good. In one patient the choice of the method of treatment was incorrect; an extensive lesion of ligamentary apparatus did not allow the correct reduction of fragments by distraction it was necessary to perform open reduction and transfixation of the fragments by means of K-wires, This patient was not included into the clinical results. Other more serious complications were not found out. Proceeding from their own experience the authors present some of the advantages of the method used: 1. Easy reduction and reliable retention of fragments 2. Possibility of the control and treatment of the damaged soft tissues 3. Possibility to perform additional operations without the danger of losing the reduction achieved a) fasciotomy b) spongioplasty c) skin grafts

Estimation of heterokaryon formation and hybridoma growth in murine and human cell fusions.

Four mouse myelomas commonly used for cell fusions (X63.Ag8.653, SP2/0, NS1, P3U1), 3 human myeloma-like cell lines (ARH77, U-266, GM1500) and 3 human x mouse hybridomas (SPAZ4, SA2, SA3) were compared for their heterokaryon formation and successful hybridoma growth after cell fusion with polyethylene glycol. The cells were stained with different fluorescent dyes which do not alter hybridoma growth or antibody secretion. After fusion myeloma cells containing at least 1 nucleus from a lymphocyte (heterokaryons) were counted from fluorescence photomicrographs and the heterokaryon frequency was calculated. Mouse myelomas fused at a frequency of 1-7%, whereas human myeloma lines showed a higher heterokaryon frequency ranging from 3-25%. In mouse fusions almost every well contained growing hybridomas showing a minimum hybridoma frequency of 2/10(6) lymphocytes. In human fusions the SPAZ4 and SA2 lines showed a heterokaryon frequency nearly as good as mouse myelomas, whereas U-266 yielded no growing hybridomas despite 20% heterokaryon frequency. Furthermore, human cell lines showed a high tendency of multikaryon formation whereas this phenomenon was rarely observed with murine and murine x human heterohybrids. In individual fusion experiments no correlation was found between heterokaryon formation and the number of growing hybridomas. Thus, our study shows that defects in hybridoma growth may not always result from lack of a successful fusion and human hybridomas might be more sensitive to post-fusion conditions.