Total Number Of Tumor Cells Research Articles

Behaviour of the Bp8 mouse ascites sarcoma after partial body irradiation.

Mice bearing the Bp8 mouse ascites sarcoma were 4 days after inoculation irradiated with 2.5, 5 and 8 Gy. By shielding the head and the upper part of the thorax the mice survival, compared with whole body irradiation, was markedly prolonged and the behaviour of the ascites tumour could be evaluated up to 30 days after inoculation. While about 10 days after irradiation the total number of tumour cells started to decrease and amounted to only 4 per cent 20 days later, the ascites volume increased up to 30 ml. Using flow-cytometric cellular DNA analysis, the proportions of cells in the various parts of the cell cycle were determined. After an initial G2 blockage, a partial blockage with an increase proportion of G2 cells was found up to 20 days after inoculation. While the total number of G1, S-phase and mitotic cells started to decrease on day 10, the total number of G2 cells was independent of the dose and was constant up to day 18. This behaviour may indicate specific regulating processes linked to G2 cells.

Studies on the distribution of abnormal cells in cytologic preparations: III. Making the smear with a plastic spatula

A model system of 15% exfoliated tumor (Ehrlich ascites) cells and 85% exfoliated cervicovaginal human squamous cells and acellular viscous mucuslike material was used to investigate the distribution of tumor cells on smear preparations. The smears were taken by the same individual, with plastic spatulas, using traditional smearing motions. The presence or absence of normal squamous cervicovaginal cells and tumor cells was recorded in 400 randomly distributed areas. Smears done with circular motions contained the largest number of tumor cells and those done with back-and-forth strokes, the least. Circular motions apparently should be preferred if the purpose is to transfer to slides the largest possible number of tumor cells. Independently of the motion employed, the largest total number of tumor cells was found in ring 9 and the lowest, in ring 5. When the various motions were taken into account, the largest number of tumor cells was found in ring 9 for smears done with zigzag strokes; the lowest, in ring 5 with clockwise circular motions. Despite these differences, comparative studies indicate that plastic spatulas may induce a more even distribution of tumor cells onto slides than wooden spatulas or cotton swab applicators. We have been unable to confirm that plastic spatulas induce better cytologic preparations than do wooden spatulas or cotton swab applicators.

Improved survival times in multiple myeloma treated with melphalan, prednisone, cyclophosphamide, vincristine and BCNU: M-2 protocol

Seventy-three patients in whom multiple myeloma could be evaluated were treated with a combination drug protocol (M-2), consisting of melphalan, prednisone, cyclophosphamide, vincristine and BCNU (1,3-bis(2-chloroethyl 1)-1-nitrosourea). All patients were classified according to the clinical staging system of Salmon and Durie; 75 per cent of them were in stage III. Total tumor cell number was calculated according to the method of Salmon. A significant objective remission was obtained in 40 of 46 (87 per cent) previously untreated patients. The median duration of response for this group is presently 20+ months. Twenty-seven of these 40 responders are still in remission. Thirteen of 26 (50 per cent) previously treated patients responded. With eight of these still in remission, the median duration of response for the group is 22+ months. The median times between the first dose and an established response were two and three months for the previously untreated and treated groups, respectively. The duration of remission in the more rapid responders does not appear to be shorter. The response rate does not appear to correlate with the type of immunoglobulin or light chain secreted. One patient, without immunoglobulin secretion, has been in remission for 45+ months, and three with primary amyloid have failed to respond. At this point, it appears that survival time in patients treated with M-2 will be significantly longer than in the earlier group treated at this center with melphalan and prednisone alone.

Specific growth regulation in three ascitic tumours

Simultaneous inoculation of two different hypotetraploid ascites tumours in the same mouse was followed by independent development of both tumours. The total number of tumour cells reached a maximum of about 2 × 10 9, i.e. twice the number of cells found in the plateau phase of growth of a single ascites tumour. Injection of cell-free ascites obtained from one ascites tumour in the plateau phase of growth into mice bearing a different kind of ascites tumour was not followed by inhibition of the tumour cells in the G-1 and the G-2 phase of the cell cycle, which is otherwise seen when the ascites is injected into mice bearing ascites tumours of the same origin. It is suggested that these findings might be explained by a tissue specific growth regulation similar to the chalone regulation of some normal tissues.

Immunotherapy in the Treatment of Acute Lymphoid Leukemia

Active immunologic stimulation has the potential of killing the “last” leukemic cell once the total number of tumor cells is reduced to about 105 by chemo- and radiotherapy. A plateau in remission duration has now persisted for more than five years in about a third of patients so treated. Thus far the favorable prognosis is confined to patients in whom the lymphoid proliferation is primarily microlymphoblastic or prolymphocytic.

Contribution of host resistance to radiosensitivity of an isologous murine lymphoma in vivo.

SummaryLSA ascites lymphoma cells were irradiated in vitro and assayed in vivo in isologous recipients. Results with the TD50 method were correlated with a separate assay using an inoculum containing a fixed total number of tumour cells and measuring the 50 per cent sterilization dose (SD50) of x-radiation. Comparison of sham- and pre-irradiated recipients showed differences which were consistent with the presence of isoantigenic tumour antigens, using the SD50 method. Host-resistance against the tumour was reduced by irradiation of the recipients, but significant differences were only evident when cell inocula were large. Isologous tumour resistance was found to become of progressively greater significance with larger numbers of radiation-killed cells. Host-resistance factors appear to increase apparent shoulder size (or extrapolation number), decrease D0, and convert a linear exponential survival curve to a more parabolic one. Host-resistance factors may contribute to cell-survival response in vivo with...