Myeloma cell resistance to melphalan, BCNU and epirubicin determined in vitro with the 3H-thymidine incorporation technique prior to chemotherapy.

Drug resistance of marrow plasma cells had been measured in vitro before chemotherapy was started. Resistance to melphalan was found in 20, to BCNU in 27 and to epirubicin in 38 out of 65 myelomas. Nineteen myelomas were resistant to a single cytostatic, 14 to two cytostatics and further 13 to all three. Patients with plasma cells resistant to melphalan in vitro failed to reduce 50% of monoclonal Ig plasma level after therapy along the VBMCP (M2) protocol, whereas sensitive myelomas responded to this program satisfactorily. Patients with cells resistant to two or three cytostatics, beside a bad therapeutic response, had also a shorter survival time. Results in vitro were in conformity with in vivo effects in 78%.

[Tendinous cords in echocardiographic studies--occurrence, clinical significance]. / Struny sciegniste w badaniu echokardiograficznym--wystepowanie, znaczenie kliniczne.

Tendinous chords inside cardiac ventricles were found in 53 (5.6%) out of 954 individuals examined echocardiographically within one year. Only 30 individuals were further analysed. No marked pathology in the cardiovascular system was found. Tendinous chord was localized in the right ventricle in 7 individuals, in left ventricle in 21, and in both ventricles in 2 subjects. Ventricular arrhythmias were shown in 11 subjects (36.6%) with the aid of a 24-hour ECG monitoring with Holter's technique. They were of the II and IV stage of advancement according to Lown's classification. Ventricular rhythm disorders were seen in both subjects with tendinous chord within left ventricle (7 subjects) and in the right ventricle (4 subjects). Local diastolic disorders with no effect on the ejection fraction were noted in all subjects with false chord and ventricular rhythm disorders. Ventricular cardiac rhythm disorders are being observed in the subjects with the false chord located within the right or the left cardiac ventricle producing local diastole disturbances.

Study of differentiation of fresh human leukemic cells by low dose cytosine arabinoside (LD Ara-C) and 12-O-tetradecanoylphorbol-13-acetate (TPA).

The effect of LD Ara-C (10(-8) mol/l) (Ara-C), TPA (1.6 x 10(-7) mol/l) and 13-cis-retinoic acid (RA) (10(-6) mol/l) on the differentiation in liquid culture of bone marrow cells from 5 patients with acute lymphoblastic, 17 patients with acute myelogenous leukemia, 1 patient in myeloid and 1 in lymphoid crisis of chronic granulocytic leukemia was studied. Ara-C induced morphological and cytochemical differentiation into monocytic cells in 2 cases (M1, M5 type). TPA induced convincing morphological and cytochemical features of maturation into monocytic cells in 4 cases (two M1, one M2, and one M5 type) and into differentiated myeloid cells in 2 cases (M1, M4 type). RA in one case (M2 type) out of three AML studied induced cytochemical and immunocytochemical features of maturation. The results of the study indicate that although TPA is a better inducer of blast cell differentiation than Ara-C, however, neither is a potent differentiation agent of leukemic blasts in liquid culture. The heterogeneity of leukemic blasts within the same type of leukemia was confirmed by their different response to differentiating agents.

Influence of small doses cytosine arabinoside (Ara-C) on leukemic cells in vitro and in vivo. Results in patients with leukemia and myelodysplastic syndrome.

The authors reviewed the literature concerned with the action of low dose Ara-C on MDS and some forms of AL and demonstrated their own results in vitro and in vivo. In vitro bone marrow blast cells short-term liquid culture were performed with and without addition of low dose Ara-C. After 5 days culture morphological and also cytochemical changes could be observed often inconsistent with the original cellular type. In vivo 8 patients suffering from AL or MDS were treated with low dose Ara-C and among them marked improvement in 3 cases only was observed.