PubMed Health⌕ Search

Biomedical subjects

H D Preisler

Publications and source records attributed to H D Preisler.

At least 19 recordsLinked to original sources
PubMed1979

Growth of human acute myeloblastic leukemic (aml) cells in vitro.

Human normal and granulocytic leukemic progenitor cells produce colonies and clusters when cultured in the plasma clot system in vitro. The number of colonies formed and their cellular composition was comparable to that reported for the system (soft agar) usually used for these studies. The plasma clot system has the advantage of permitting in situ morphologic and cytochemical characterizaion of the cells within the colonies. A comparison was also made of the growth of leukemic cells in suspension cultures placed within conventional and modified Marbrook flasks. These studies demonstrated no advantage for the Marbrook system in cultures incubated for up to 7 days.

Culture Techniques↗
PubMed1979

Sensitization in vitro to murine myeloblastic leukemia cells by xenogeneic immune RNA.

Normal murine spleen cells were sensitized to syngeneic myeloid leukemia cells by RNA extracted from the lymph nodes and spleens of Hartley guinea pigs immunized with the murine leukemia cells. Sensitization mediated by RNA was an active process that required physiologic temperature and at least a 10-minute incubation. RNA extracted from unimmunized guinea pigs of guinea pigs immunized with normal spleen cells failed to sensitize the mouse spleen cells. Sensitization was specifically directed toward leukemia cells, whereas the spleen cells remained unreactive toward normal spleen or bone marrow cells. The sensitizing moiety was RNA itself inasmuch as it was inactivated by RNase and not by DNase or pronase. Preparations whose RNA patterns on sucrose density centrifugation gave evidence of degradation of the RNA did not sensitize normal spleen cells. These studies demonstrate that xenogeneic immune RNA can specifically sensitize normal spleen cells to syngeneic myeloid leukemia cells.

Animals↗
PubMed1979

Effects of partially thiolated polycytidylic acid on the clonogenicity of murine leukemic stem cells.

The effect of partially thiolated polycytidylic acid (MPC) on the colony-forming ability of the progenitor cells (CFUC) of RF/Un leukemic mice was investigated using the plasma clot method in order to study the mode of action of the modified polynucleotide. The results showed that MPC inhibited the CFUC in a dose-dependent and time-dependent manner. Once a maximum level of inhibition of CFUC (approximately 40%) was observed, no further inhibition occurred whether the concentration of MPC was increased or whether the duration of incubation was lengthened. High-specific-activity [3H]thymidine, an S-phase-specific agent, showed a similar inhibition profile on the CFUC as did MPC. When MPC and high-specific-activity [3H]thymidine were incubated together with the bone marrow cells, there was no additive or synergistic inhibitory effect on the CFUC. Thus, it appears that MPC is an S-phase-specific agent. When injected i.v. into the mice, MPC decreased the number of CFUC of both the bone marrow and the spleen significantly.

Animals↗
PubMed1979

A method for obtaining human bone marrow specimens enriched for myeloblasts and promyelocytes.

A simple method has been developed for obtaining specimens of human marrow which are enriched for myeloblasts and promyelocytes. The erythrocytes are lysed, the marrow is incubated with iron particles, and the cells that phagocytize the iron are removed with a powerful magnet. The marrow is then subjected to a density-cut centrifugation using Ficol-Hypaque with a density of 1.084 gm/mm3. The cells that do not enter the Ficol-Hypaque are removed from the surface and studied. The proportion of myeloblasts and promyelocytes in this subpopulation of cells exceeds 50%. Total recovery of these immature myeloid progenitor cells is 50% of that in the original marrow specimen. This method has been used for cell suspensions containing as many as 10(9) cells. Cells prepared using this method incorporate 3H-TdR, 3H-UR, and 3H-Leu at a higher rate than the unseparated specimens and have a cloning efficiency of 2.0% to 19.4% compared with 0.1% to 2.17% for the unseparated marrows.

Cell Separation↗
PubMed1978

Friend leukemia cells: relationship between differentiation, clonogenicity and malignancy.

Friend leukemia cells were cultured in vitro in the presence or absence of agents which induce erythroid differentiation. The cultures were harvested and the degree of differentiation determined. Clonogenicity of the cells in vitro and malignancy in vivo were determined as well. There was an inverse exponential relationship between the degree of differentiation and the clonogenicity of the culture. Differentiation was also associated with a modest decline in malignancy. Of interest was the observation that bromodeoxyuridine inhibited the biochemical manifestations of erythroid differentiation, but did not prevent the decline in clonogenicity which accompanied differentiation.

Animals↗
PubMed1978

Carcinoma of unknown primary: natural history and response to therapy.

Twenty-three consecutive patients with metastatic carcinoma of unknown primary referred to a medical oncology service over the past two years were studied. In the majority of patients, death occurred within one year of diagnosis and a priamry site of disease was identified at postmortem examination. Of patients who had a primary site identified, findings suggestive of involvement of that site were present during the course of their illness. Survival was greatest in patients with adenocarcinoma histology, with lymph node site of presentation and in those treated with both radiation therapy and chemotherapy, although these differences were not statistically significant. Despite the prolonged survival of a few patients, it is clear that failure to extensively evaluate subtle clinical findings and the lack of efficacious therapy for the malignancies commonly encountered seriously limit the survival of the vast majority of these patients. The identification of new tumor markers and the use of adjunctive chemo-immunotherapy to excisional surgery may ultimately improve to outlook for these patients.

Adenocarcinoma↗
PubMed1977

Acute myelogenous leukemia subsequent to therapy for a different neoplasm: clinical features and response to therapy.

The clinical characteristics of 10 patients with acute myelogenous leukemia (AML) which developed subsequently to treatment for another neoplasm are described. This disease appears to differ from "spontaneous" AML in being associated with lesser degrees of leukemic infiltration of the marrow and more frequent chromosomal aberrations. Only one of the nine patients who received chemotherapy attained remission status, and the mean and median survivals from the initiation of chemotherapy were 2.7 months and one month respectively. Nine of the 10 patients died as a result of infection. The refractoriness of this form of AML to chemotherapy was borne out by a review of the literature, which revealed only two remissions in 32 treated patients. The implications for the management of this disease are discussed.

Bone Marrow↗
PubMed1977

Murine myeloid leukemia: I. Pathophysiology and drug sensitivity.

The pathophysiology of serially passaged myeloid leukemia of the RFM mouse was studied. The disease was characterized by progressive splenomegaly and infiltration of both marrow and spleen by myeloblasts. The animals became anemic and there was an associated erythroid hyperplasia in the spleen. Leukemic spleen cells obtained from animals early in the course of the leukemia were less malignant than those obtained from preterminal mice. The leukemia is most sensitive to alkylating agents but is also responsive to antimetabolites.

Alkylating Agents↗
PubMed1977

Separation of leukemic cells into proliferative and quiescent subpopulations by centrifugal elutriation.

Centrifugal elutriation was used to separate human acute leukemia cells into proliferative and quiescent subpopulations. Ten bone marrow specimens and 5 peripheral blood specimens were subjected to centrifugal elutriations. From each patient, leukemic cell subpopulations were obtained for which the [3H]thymidine labeling index differed by 10- to 30-fold. In 6 of the marrow specimens and in 2 of the peripheral blood specimens, cell subpopulations were obtained for which the labeling index exceeded 20%. In 5 marrow specimens, subpopulations were obtained for which the labeling index exceeded 40%. Preliminary studies of the uptake of 1-beta-D-arabinofuranosylcytosine and 5-azacytidine failed to show any correlation between drug uptake and the proliferative characteristics of the leukemic subpopulations.

Azacitidine↗
PubMed1975

Differentiation of erythroleukemic cells in vitro: irreversible induction by dimethyl sulfoxide (DMSO).

The inclusion of DMSO in the media of suspension cultures of Friend erythroleukemia cells results in the erythroid differentiation of these cells. The studies reported here were directed towards answering two questions. (1) How long an exposure to DMSO is necessary to induce the differentiation of these cells; and (2) What is the fate of the differentiating cells when DMSO is removed from the medium. Exposure to DMSO for less than 24 hours failed to produce any detectable evidence of erythroid differentiation. On the other hand, culture in the presence of DMSO for 24 hours followed by culture in DMSO-free medium for four additional days produced a small but detectable increment in the proportion of benzidine positive cells in the culture. Once the differentiation of an individual cell was initiated, the process continued after removal of DMSO from the medium. The cell became progressively more differentiated as evidenced by increases in the intensity of benzidine staining as well as the rate of heme synthesis and heme content. However, when cells which had been induced to differentiate by DMSO were cultured in DMSO-free medium for more than 3--4 days, they became vacuolated and apparently died. This latter phenomenon, as well as the more rapid proliferation of the undifferentiated cells in the culture, accounts for the observation that when new cultures are established from cultures which have been grown in the presence of DMSO for several days, the culture which results ultimately contains only differentiated cells.

Benzidines↗
PubMed1975

Granulocyte differentiation by Friend leukemia cells.

Friend leukemia cells growing in suspension culture are thought to represent a population of primitive erythroid cells which have undergone malignant transformation. We have found that when growing in vivo or in plasma clots in vitro, these suspension culture cells can exhibit morphologic and enzymatic properties which are characteristic of primitive granulocytic cells. The microenvironment in which the tumor cells grow plays a major role in determining the direction of differentiation of these leukemia cells. Hence it appears likely that the Friend cell is in fact a neoplastic pluripotent hematopoietic stem cell.

Animals↗