氯化四乙基铵及维拉帕米对家兔缺血心肌不应期的影响

实验比较了K⁺通道阻断剂氯化四乙基铵(TEA)及Ca²⁺通道阻断剂维拉帕米(verapamil,Ver)对家兔缺血性心室肌不应期(ERP)的影响。结果表明,阻断冠脉10min及30min后,缺血中心区(CIZ)和缺血边缘区(BIZ)心肌ERP比缺血前均明显缩短,而TEA和Ver均能延长急性缺血性心肌的ERP,可能对心肌缺血引起的心律失常有预防作用。     

单克隆抗体BDI-I导向的阿霉素白蛋白毫微球对人膀胱癌细胞的特异杀伤活性

用化学偶联法将抗人膀胱癌单克隆抗体分子偶联到阿霉素白蛋白毫微球上,构建了一个有靶向杀伤性的免疫毫微球,即:阿霉素白蛋白载单克隆抗体毫微球(ADR-NP-Ab)。改变阿霉素毫微球和单克隆抗体的反应分子比,确定了制备该免疫毫微球的最佳条件。经免疫荧光检测及显微照像分析证明,免疫毫微球可有效地和人膀胱癌细胞结合。体外杀伤试验表明,此免疫毫微球对靶细胞EJ有高度特异杀伤活性,而对无关的人直肠癌Lovo细胞则无明显作用。     

Thymidylat-de novo-Synthese,salvage pathway und DNS-Synthese während der Differenzierung von Erythroblasten

Zusammenfassung Die de novo-Synthese von Thymidinmonophosphat in erythropoetischen Knochenmarkzellen einer normalen Ratte und einer gesunden Versuchsperson wird durch in vitro-Inkubation mit Fluordesoxyuridin FUdR) blockiert. Zur Aufrechterhaltung einer normalen DNS-Synthesegeschwindigkeit erhöhen die Zellen kompensatorisch die Inkorporationsrate von¹⁴C-Thymidin aus dem Inkubationsmedium. Dadurch können der Anteil des salvage pathway an der Thymidylat-Synthese und die DNS-Synthesegeschwindigkeit mit Hilfe einer quantitativen autoradiographischen Methode in den einzelnen Reifungsstufen bestimmt werden. Der Anteil des salvage pathway unter 10^–5m Thymidin liegt bei der Ratte mit 40 bis 80% erheblich höher als beim Menschen mit 28 bis 37%. In beiden Fällen findet sich bei den polychromatischen Erythroblasten sowohl ein geringerer Anteil des salvage pathway an der Thymidinmonophosphat-Synthese als auch eine deutlich geringere DNS-Synthesegeschwindigkeit als bei den Proerythroblasten und basophilen Erythroblasten.

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Summary The de novo synthesis of thymidinemonophosphate is blocked by in vitro incubation with fluorodeoxyuridine (FUdR) of erythropoietic bone marrow cells of a normal rat and a healthy individual. The cells maintain a normal DNA synthesis rate under these conditions by increasing the incorporation rate of¹⁴C-thymidine out of the medium. Thereby the participation of the salvage pathway in the synthesis of thymidilate as well as the DNA synthesis rate can be evaluated. This is by means of a quantitative autoradiographic method in the different erythropoietic maturation stages. The participation of the salvage pathway in the erythropoietic cells of the rat with 10^–5m¹⁴C-thymidine amounts to 40 to 80%. This is considerably higher than in the human cells where a participation of 28 to 37% is found. The salvage pathway activity as well as the DNA synthesis rate is markedly lower in polychromatic erythroblasts than in proerythroblasts and basophilic erythroblasts of both rat and man.

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Studie im Rahmen des Assoziationsvertrages EURATOM-GSF für Hämatologie Nr. 031 641 BIAD. Unterstützt von der Deutschen Forschungsgemeinschaft: SFB 51/5.     

Characterization of new murine monoclonal antibodies directed against glycophorins C and D

SUMMARY. Six new murine monoclonal antibodies (mAbs) directed to the erythrocyte membrane glycophorins C (GPC) and D (GPD) were obtained from splenocytes of different BALB/c mice immunized with human red blood cells, and fully characterized. The mAbs were selected by agglutination tests with control and Gerbich-negative cells, and by immunoblotting analysis. They showed specificity for the N-terminal domain(s) of GPC (and GPD) and were classified into three categories by competitive analysis using ¹²⁵Ilabelled antibodies and real-time biospecific interaction. The first group (NaM10-7G11, NaM70-1G4 and NaM77-7B6) compete for epitope(s) located at the N-terminal portion of GPC. Agglutination-inhibition tests revealed that the 7G11 epitope involves the amino group of Met¹ and sialic acid residue(s) whereas the 1G4 and 7B6 epitopes contain O-glycans. NaM89-2G11 belongs to a second group; its epitope is located in a region including Glu¹⁷, Asp¹⁹ and (an) O-glycan(s). The third group comprises mAbs NaM19-3C4 and NaM98-3Cl which bind to both GPC and GPD in proximity of the binding site of human anti-Ge:3 antibodies.
In addition, mAb 3C4 (anti-GPC/GPD) was found to bind to approximately 125 000 sites per red cell. Considering that the ratio of the GPC to GPD is about 3–4 to 1, the number of GPC and GPD molecules was estimated as 95 000 and 35 000, respectively.