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Biomedical subjects

G Spitzer

Publications and source records attributed to G Spitzer.

At least 145 records · Page 8Linked to original sources
PubMed1984

Normalization of in vitro sensitivity testing of human tumor clonogenic cells.

The use of normal bone marrow (granulocyte-macrophage colony-forming units) as a point of reference to normalize the in vitro activities of anticancer agents has been investigated. The cytotoxic effects of four substituted anthraquinone derivatives, and of vinblastine on myeloid progenitors of different donors were reproducible up to a cell kill of approximately 60%. Equitoxic in vitro concentrations for normal bone marrows did not correlate with in vivo pharmacokinetic concentrations of these drugs. Breast tumor progenitor cells of 46 specimens were more sensitive than were bone marrow progenitors to the anthraquinone derivatives in 26 to 39% of instances, ratios which are similar to the clinically observed response rates of patients with breast carcinoma to these agents. Tumors were either sensitive or resistant to all four drugs in 68% (10 tumors were more sensitive, and 21 tumors were less sensitive than normal bone marrow); but in 32% of instances there were differences in tumor sensitivity for the four drugs, and the assay could select one to three drugs for which the tumor sensitivity was greater than that of bone marrow. Correlations of in vitro sensitivity and of clinical response to single agent treatments were determined in 21 patients, and the concordance was 71%. The value of the assay in predicting clinical response ranked best for sensitivity determinations within the normalized dose ranges, when testing within three different dose ranges was compared in a group of six patients. The concordance was higher in the small (1 or 2 metastatic sites) than in the large (greater than or equal to 3 metastatic sites) tumors (85 versus 50%), indicating a confounding influence of tumor load on the ability of the assay to predict efficacy of treatment. A rule of thumb is proposed for altering the in vitro sensitivity test results for large tumors that improves the overall concordance to 90%.

Antineoplastic Agents↗
PubMed1984

Mobilization of canine hemopoietic stem cells by pyran copolymer (NSC 46015).

Pyran copolymer (NSC 46015), a divinyl ether maleic anhydride of broad spectrum molecular weight, was infused into six normal mongrel dogs. The effect on canine blood and bone marrow colony forming units in culture (CFU-C) was followed over an 11-day period. Significant elevation of circulating CFU-c was noted 2 days after pyran infusion; normalization occurred by day 7 postinfusion. Bone marrow CFU-C were decreased 2 days and 5 days after pyran administration. A further increase in circulating CFU-C was noted when pyran was administered twice, 5 days apart. The mobilizing effect of pyran copolymer appears promising enough to warrant further exploration of blood as a source of hemopoietic stem cells for transplantation purposes.

Animals↗
PubMed1983

High-dose chemotherapy and autologous bone marrow transplantation for the treatment of small cell lung carcinoma.

Fourteen patients with untreated small cell bronchogenic carcinoma were treated initially with 2 chemotherapy courses of cyclophosphamide (1.5 g/m2 days 1-3), 4-dimethyl epipodophylloxtin (200 mg/m2 days 1-3), vincristine (1.5 mg/m2 days 1 and 3), and with Adriamycin (80 mg/m2 day 1) in 8 patients and without Adriamycin in 6 patients. To modify hematopoietic toxicity from these high doses of chemotherapy, autologous marrow collected and frozen before storage was thawed and infused after each of these high-dose therapies. After this therapy patients received prophylactic brain irradiation (3000 rad), 4 courses of usual doses of these same drugs and then 5000 rad chest irradiation if there was still evidence of disease (PR) or randomized to radiation if in complete remission (CR). Response rate was high, with 54% CR and 46% PR, a total of 100%. However, a median response duration of 41 weeks and median survival of 56 weeks, are similar to other chemotherapy programs. Toxicity was mild except for cardiac arrhythmias when Adriamycin was included. The reasons for no therapeutic increment are discussed.

Aged↗
PubMed1983

High-dose chemoradiotherapy and bone marrow transplantation in patients with refractory lymphoma.

Eight adult patients with refractory Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL) were treated with high-dose combination chemotherapy (cyclophosphamide, BCNU and VP-16) or with cyclophosphamide and fractionated whole-body irradiation (TBI), followed by bone marrow transplant (BMT). Six patients received autologous and two patients allogeneic BMT. Five patients achieved complete remissions, and three of them (two with undifferentiated lymphoma, one with lymphoblastic lymphoma) are alive and free of disease 4-18+ months after BMT. The other two complete responders died of opportunistic infections 2 and 5 months, respectively, after BMT. One patient with HD achieved partial remission and is alive 18+ months after BMT. Two patients were considered failures: one developed leptomeningeal disease 24 days after BMT, and the other died of progressive lymphoma 7 months after BMT. Engraftment and prompt hematologic recovery occurred in all patients. The major toxicity included two fatal infections and one case of diffuse idiopathic interstitial pneumonitis. High-dose chemotherapy with or without TBI followed by BMT appears to produce a high response rate and, although associated with toxicity, it demonstrates the potential for salvaging patients with refractory lymphoma who otherwise would have a dismal prognosis.

Adult↗
PubMed1983

Effect of diethylaminoethyl-dextran on colony formation of human tumor cells in semisolid suspension cultures.

The effect of diethylaminoethyl-dextran on colony formation of established and primary human ovarian and breast tumor cells in semisolid suspension cultures was investigated. At the concentration of 250 to 300 micrograms/ml used in the human tumor stem cell assay, diethylaminoethyl-dextran inhibited in vitro growth of 3 of 4 human breast tumor cell lines and of 10 of 19 primary tumors. It did not affect growth in 7 primary tumors and enhanced colony formation in 2 tumors. We suggest that diethylaminoethyl-dextran may interact in the human tumor stem cell assay with other sites additional to sulfuric acid residues of the agar and that these effects may cancel or outweigh its purported beneficial effects.

Breast Neoplasms↗
PubMed1982

Human leukocyte interferon-mediated granulopoietic differentiation arrest and its abrogation by lithium carbonate.

Interferon has been shown to inhibit erythropoietic and granulopoietic differentiation. Since lithium carbonate (Li) elevates granulocyte levels in a variety of neutropenic disorders, we investigated the effect of Li on human leukocyte interferon (HLIF)-mediated inhibition of granulopoietic differentiation. Using an agar culture technique for cloning granulocyte-macrophage progenitor cells (GM-CFC), we demonstrated that Li blocks HLIF-induced granulopoietic differentiation arrest in a dose-dependent manner. Results of removal of T lymphocytes from marrow cells suggest that this Li effect is not mediated through marrow T lymphocytes.

Cell Differentiation↗
PubMed1982

DR antigen positive monocyte-macrophages control granulocyte-macrophage colony-stimulating activity and burst promoting activity elaboration in man.

To investigate the mechanisms that modulate granulocyte-macrophage colony-stimulating activity (GM-CSA) and burst promoting activity (BPA) elaboration, we studied human peripheral blood-derived monocyte-macrophage (M0) and T-lymphocyte (TL) interaction. Coincubation of live M0 with autologous TL at a 1:3 ratio in the presence of 1% phytohemagglutinin synergistically increased GM-CSA (6 of 6 experiments) and BPA (4 of 6 experiments) (P less than 0.002). Prior treatment of M0 with cycloheximide or actinomycin D significantly (P less than 0.002) diminished this M0's capacity to collaborate with TL. Mitomycin C treatment did not. Live M0 also enhanced TL-derived GM-CSA (P less than 0.002) and BPA (P less than 0.001). This enhancement was again compromised by prior cycloheximide or actinomycin D treatment, but not by mitomycin C treatment. Further experiments in which we blocked DR antigen on M0 membrane with monoclonal anti-DR antibodies suggested that M0 required their membrane DR antigen to collaborate with TL in elaborating GM-CSA and BPA.

Bone Marrow Cells↗
PubMed1982

Cyclic neutropenia and T lymphocyte suppression of granulopoiesis: abrogation of the neutropenic cycles by lithium carbonate.

To investigate the mechanisms of cyclic neutropenia, we studied the capacity of a patient's T lymphocytes (TLp) to interact with monocyte-macrophages from her normal HLA-identical sibling (MOb) in the elaboration of colony-stimulating activity (CSA). TLp obtained at the time of decreasing neutrophil counts, increased CSA elaboration (p less than 0.056) when incubated at a 1:1 ratio with MOb. Increasing the TLp to MOb ratios to 3:1 or 5:1 progressively decreased CSA. Also, lithium carbonate, which ordinarily prevents concanavalin A activation of suppressor TL, failed to do so, suggesting that preactivated suppressor TL were present in the patient while neutrophil levels were falling. In similar experiments performed while neutrophil levels were rising these activated suppressor TL were absent. These data suggest that some patients with cyclic neutropenia may have a cyclic increase in suppressor TL activity. As predicted by our in vitro experiments, lithium carbonate administration did not abrogate the first neutropenic cycle, but it did mitigate subsequent cycles.

Adult↗
PubMed1982

The mechanism of lithium carbonate-induced augmentation of colony-stimulating activity elaboration in man.

Lithium carbonate (Li) has been reported to elevate granulocyte counts in patients with certain neutropenic disorders and to improve chemotherapy-induced granulocytopenia. To investigate the mechanisms involved in the increase in myelopoiesis, the effect of Li on monocytemacrophage (M phi)- and T-lymphocyte (TL)-derived colony-stimulating activity (CSA) were studied in vitro. Li induced a dose-related increase in both M phi- and TL-derived CSA over that in non-Li-stimulated cell populations. However, the increase was significant (p less than 0.007) only at a higher concentration of Li (2 mEq/l). The results of co-incubating TL with M phi with or without Li indicated that Li significantly enhanced synergistic CSA production by the two cell populations (p less than 0.02). We further demonstrated the presence of a larger proportion of M phi with TL rosettes in the presence of Li (62%) than in its absence (21%). Further experiments with concanavalin A (Con-A)-inducible suppressor TL suggested that Li effectively blocks the suppressor TL-mediated suppression of CSA. These data suggest that Li enhances M phi and TL interaction which results in an augmented CSA elaboration. Further, Li would be more effective in those neutropenic disorders associated with enhanced suppressor TL activity. For an optimal effect, however, Li would require appropriately functioning M phi and non-suppressor subsets of TL and an intact stem cell pool.

Cell Division↗
PubMed1982

Monocyte-macrophage modulation of T-lymphocyte-derived colony-stimulating activity elaboration in man.

To investigate the source and the mechanisms of synergistically enhanced colony-stimulating activity elaboration by the coincubated monocyte-macrophages and T lymphocytes, we simultaneously prepared conditioned media both from the coincubated monocyte-macrophages and T lymphocytes (ratio 1:3) in the presence of phytohemagglutinin (1%) or methanol extraction residue of bacillus Calmette-Guerin (50 micrograms/ml) and from the isolated T lymphocytes that had been primed with monocyte-macrophages in the presence or absence of phytohemagglutinin or methanol extraction residue of bacillus Calmette-Guerin. Subsequently, colony-simulating activity in various conditioned media was assayed using light-density (less than 1.070 g/ml), nonadherent normal human marrow cells. Live monocyte-macrophages synergized with and significantly (P less than 0.01) agumented the T lymphocyte-derived colony-stimulating activity elaboration; while killed monocytes-macrophages had no such effect. Similarly, actinomycin D and cycloheximide not only diminished monocyte-macrophage colony-stimulating activity elaboration but also reduced their synergistic interaction with T lymphocytes and their ability to augment the T lymphocyte-derived colony-stimulating activity elaboration. In contrast, mitomycin C failed to diminish both - monocyte-macrophages' ability to synergise with T lymphocytes and also to augment T lymphocyte-derived colony-stimulating activity. These data suggest that monocyte-macrophages require an intact transcriptional and translational processes, but not DNA synthesis for synergising with T lymphocytes or for augmenting T lymphocyte colony-stimulating activity elaboration.

Cell Adhesion↗
PubMed1982

Cells with Fc gamma receptors from normal donors suppress granulocytic macrophage colony formation.

We investigated the role of normal human marrow cells with Fc receptors for IgG (Fc gamma+) on autologous granulocyte-macrophage colony (GM-CFC) formation. It was found that Fc gamma+ normal human marrow cells, both with (E+) or without receptors for sheep erythrocytes suppressed GM-CFC at as low a concentration as 0.25 X 10(5) cells/ml of culture. A similar effect was observed with E- Fc gamma+ but not E+ Fc gamma+ peripheral blood cells. Suppression by Fc gamma+ cells did not require mitogen activation and was not inactivated by irradiation (2000 R). This report presents a new in vitro regulatory mechanism for GM-CFC growth in normal donors.

Bone Marrow↗
PubMed1982

Human adherent cell contact-mediated modulation of normal myeloid colony formation.

The effects of coincubation of normal nonadherent bone marrow cells on adherent monolayers created from human peripheral blood mononuclear cells or marrow cells were investigated. Nonadherent marrow cells were coincubated for 4 hours with peripheral blood adherent cells at ratios of adherent cells to marrow cells of 2:1 to 5:1. This coincubation suppressed subsequent neutrophilic agar colony growth but not eosinophilic growth. Further studies suggested that this suppression was a cell-cell-mediated process and not secondary to soluble factors. However, coincubation on marrow adherent cells caused increased neutrophilic colony recovery. The possible in vivo relevance is discussed.

Agar↗
PubMed1982

High-dose AMSA and bone marrow rescue in patients with solid tumors.

The feasibility of high-dose AMSA followed by autologous bone marrow rescue was studied in seven patients with solid tumors. They received a total of 12 courses of treatment. Total doses ranged from 600 to 1000 mg/m2/course. Major toxic effects were myelosuppression, fever of unknown origin, and stomatitis. One patient with malignant melanoma had stable disease lasting 2 months; the other six had progressive disease.

Aminoacridines↗
PubMed1982

Testosterone and synthetic and androgens improve the in vitro survival of human marrow progenitor cells in serum-free suspension cultures.

The direct effect of testosterone and its synthetic analogs on the maintenance of human erythroid progenitor cells (BFU-E) and GM-CFC was studied in suspension cultures. To avoid interference by serum components, the experiments were conducted in serum-free media containing insulin, transferrin, selenium, BSA, and alpha-thioglycerol. When added at concentrations between 10(-7)M and 10(-9)M, testosterone improved survival of BFU-E and GM-CFC. Of the nine analogs tested, eight improved BFU-E maintenance in vitro: nandrolone norethandrolone, and oxymetholone were most active, whereas etiocholanolone had only marginal effects. The influence of these compounds on GM-CFC was less pronounced, with testosterone showing the highest activity. It is concluded that testosterone and some of the synthetic analogs tested exert their hemopoietic effect, at least partly, by affecting the maintenance of erythroid and granulocytic stem cells, directly by increasing their survival or proliferation or indirectly by increasing the input from multipotent stem cell pool, or by both mechanisms.

Cell Count↗