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Biomedical subjects

G Spitzer

Publications and source records attributed to G Spitzer.

At least 181 records · Page 10Linked to original sources
PubMed1980

One-step procedure for human T-lymphocyte colony growth and its regulation by T and B cells, and monocytes.

Previous systems for cloning human T-cells have been either one step procedures with small colony size (40 less than 40 cells) or two-step procedures with agglutination problems. These systems also require erythrocytes, thiols and human serum. We have regularly grown more than 10(3) colonies (more than 40 cells)/5 X 10(5) cells from purified T-cells or phagocytic and adherent cell depleted mononuclear cells in agar using phytohemagglutinin (PHA) as the mitogenic stimulus. The reason for the poor colony size in other single step procedures using agar may be related to cell-to-cell interaction. We found that both adherent (Ad) and phagocytic cells were suppressive of T-cell colony growth (TCCG) in donors with low or absent TCCG from whole mononuclear cells. This effect was reproduced by adding Ad cells to T-cell concentrated fractions. Both irradiated T and unirradiated enriched B-cells increased TCCG of T fractions. TCCG is possible in simple in vitro systems from both adherent and phagocytic cell depleted fractions and concentrated T-cell fractions. This allows for the examination of factor regulation of TCCG and has enabled the identification of a possible B-cell released T-cell growth factor. Previously described complex growth requirements may be related to cell interactions.

B-Lymphocytes↗
PubMed1980

Enhancement of hemopoietic recovery after bone marrow transplantation with the addition of nucleated blood cells in mice.

Recovery of bone marrow cellularity, CFU-C, and CFU-S were studied sequentially over 90 days time after syngeneic bone marrow transplantation in mice. A minimal cell dose of 2 X 10(5) bone marrow cells was given. At day 28 after transplantation, CFU-C reached more than 50% of the normal range whereas the CFU-S concentration was less than 15%. Normalization of CFU-S occurred at day 90. The effect of the addition of peripheral blood nucleated cells on bone marrow hemopoietic recovery was studied at day 28. The augmentation of CFU-C and CFU-S recoverey were dose dependent. Optimal enhancement was seen with bone marrow to blood ratios of 1:1 and 1:2.5. This enhancement effect was lost when nucleated blood cells in a ratio of 1:10 were administered.

Animals↗
PubMed1980

Pyran copolymer: effect of molecular weight on stem cell mobilization in mice.

Maleic anhydride divinly ether copolymer polyanions (MVE) of well defined molecular weight ranging from 12,000 to 52,000 and Pyran Copolymer (NSC 46015), a MVE preparation with broader molecular weight range, were tested for their ability to mobilize murine stem cells, colony forming units spleen (CFU-S) and colony forming units in culture (CFU-C). Maximal mobilization of circulating stem cells was seen five days after Pyran Colopymer injection. This time point was chosen to determine the mobilization effect of different MVE preparations. It was found that the mobilization paralleled the molecular weight: the observed increase of circulation CFU-S by fractions MVE II, III, IV, and V and NSC 46015 were 3, 5, 14, and 20 fold.

Animals↗
PubMed1980

Effect of pyran copolymer on murine hemopoiesis.

Pyran Copolymer (NSC-46015), a divinyl-ether maleic anhydride leads to a significant shift in distribution of nucleated cells and CFUs in the bone marrow and spleen. The bone marrow cellularity and the CFUs content reach a nadir 4 to 6 days after Pyran injection, simultaneous rise in spleen cellularity and CFUs concentration of circulating pluripotent stem cells by a factor of 10 to 45 and a concomitant rise of CFUc is seen. the origin of the mobilized pluripotent stem cells is likely to be the bone marrow, not athe spleen.

Animals↗
PubMed1979

Autologous bone-marrow transplantation in relapsed adult acute leukaemia.

24 cases of adult acute leukaemia, of which 21 were evaluable, were treated in irreversible relapse with high-dose piperazinedione and supralethal total-body irradiation (T.B.I.) in conjunction with autologous marrow transplantation (A.B.M.T.). The grafted marrow cells had been collected and stored in liquid nitrogen at the time of remission. In 12 patients the marrow cells were fractionated on discontinuous albumin gradients in an attempt to separate normal cells from residual leukaemic cells. 11 patients achieved complete remission (C.R.); 7 other patients had signs of engraftment but died before C.R. The median remission duration was 4 months (2-14). 6 of 9 acute myeloblastic leukaemia patients, in whom bone-marrow transplantation was the first treatment of relapse, achieved C.R. 4 of 5 patients with acute lymphoblastic leukaemia, whose bone-marrow cells were collected during first remission, reached C.R. Autologous bone-marrow transplantation is a valuable first treatment for acute myeloblastic leukaemia in relapse and acute lymphoblastic leukaemia in second relapse.

Adolescent↗
PubMed1979

Mobilization of murine hemopoietic stem cells (HSC) by Pyran Copolymer.

Pyran Copolymer, divinyl-ether maleic anhydride increases the concentration of circulating pluripotential stem cells in mice by a factor of 15 to 30. Maximal mobilization occurs five days after Pyran Copolymer injection with synchronous peaks of CFU-S and CFU-C. When Pyran fractions of defined molecular weight from 12,000 to 52,000 are injected into mice, mobilization of CFU-S and CFU-C parallels molecular weight. Hemopoietic stem cells are mobilized from bone marrow into peripheral blood and subsequently trapped in the spleen.

Animals↗
PubMed1979

Possible mechanisms of action of lithium on augmentation of in vitro spontaneous myeloid colony formation.

To understand the possible mechanisms of lithium carbonate-induced neutrophilia, the in vitro effect on human myeloid progenitor cells was examined. A significant increase in spontaneous colony formation (15 of 24 experiments) was observed with the addition of lithium. Increased colony formation seldom occurred when human placental conditioned media as a source of colony-stimulating activity (CSA) was simultaneously added to the cultures. Further data suggest that lithium requires an adherent marrow cell population for this action and that increases in CSA-containing cultures may be due to suboptimal CSA concentrations. Lithium was shown to release CSA from marrow cells and adherent cell population prepared from human bone marrow. Lithium possibly increases spontaneous human myeloid colony development indirectly through CSA release by adherent cells.

Bone Marrow↗
PubMed1979

Human leukocyte interferon preparation blocks granulopoietic differentiation.

Since interferon administration in the treatment of some malignant conditions has been reported to cause leukopenia, we studied the effects of human leukocyte interferon preparation (HLIF) on myelopoiesis in vitro. The continual presence of HLIF in semisolid agar cultures caused a progressive decline in colony and a rise in cluster incidence with increasing concentrations of interferon. The total plating efficiency, however, remained nearly constant, regardless of the HLIF doses used. Morphological examination of the clusters demonstrated a progressively increasing percentage of immature granulocytic precursors with increasing HLIF concentrations. This suggests that HLIF causes leukopenia by blocking differentiation of marrow myeloid precursors.

Cell Aggregation↗
PubMed1979

High-dose BCNU therapy with autologous bone marrow infusion: preliminary observations.

Nine patients with solid malignancies and extensive prior treatment received high-dose BCNU therapy (600--750 mg/m2) with autologous bone marrow support; following this treatment hematopoietic recovery was studied. The only significant nonhematopoietic toxicity was a probable case of BCNU-induced pulmonary toxicity in a patient who had received massive amounts of prior chemotherapy and chest irradiation. The marrow aspirations prior to cryopreservations had revealed a hypoplastic marrow in four of nine patients. Despite using marrow exposed to prior chemotherapy, neutropenia beyond Day 40 after BCNU therapy was not observed in any patient. One patient did not develop neutropenia of less than 1.5 X 10(9) cells/liter and five patients did not develop neutropenia of less than 0.5 X 10(9) cells/liter. A partial response was observed in one patient and less than partial responses were observed in two other patients. Autologous bone marrow infusion may modify the neutropenia of high-dose BCNU therapy.

Adult↗
PubMed1979

Autologous bone marrow transplantation in relapsed adult acute leukemia.

From March, 1976 to February, 1979, 28 cases of adult acute leukemia of which 24 were evaluable were treated in irreversible relapse with high dose chemotherapy (piperazinedione) and supra-lethal total body irradiation (TBI) in conjunction with autologous bone marrow transplantation (ABMT). The marrow cells grafted were collected and stored in liquid nitrogen at the time of remission. In 12 patients the marrow cells were fractionated using discontinuous albumin gradients in an attempt to separate normal cells from residual leukemic cells. Twelve patients achieved complete remission (CR); in 9 additional patients signs of engraftment were evident but death occurred before achievement of CR. Seven of 12 AML patients, which were treated with bone marrow transplantation as first treatment of their relapse, achieved CR. Four of 5 patients with ALL, whose bone marrows were collected during first remission, reached CR. The median CR duration was 4+ months and the median survival of the patients reaching CR was 6+ months. Autologous bone marrow transplantation offers a good chance of CR (66%), when marrow is collected during first remission and used as first treatment for AML in third relapse and ALL in second relapse.

Adolescent↗
PubMed1979

Myelopoietic enhancement by immunoadjuvants: in vitro studies for their rational use in neutropenic patients.

Following marrow transplantation, the clinical course of the patients is invariably complicated by severe infections due to neutropenia and immuno-incompetence. With a view to explore means of alleviating these complications, Bacillus Calmette-Guerin (BCG), methanol extraction residue of BCG (MER), Corynebacterium parvum (C. parvum) and Pyran were examined for their myelopoietic activity on human marrow. Light density (less than or equal to 1.077 g/ml) unfractionated (UF) cells (2 X 10(6)/ml and 2ml/dish), and adherent (Ad) and non-adherent (N-Ad) cells alone (derived from 4 X 10(6) UF cells per dish) were incubated with and without the above agents. The conditioned media (CM) were harvested at 24, 72, 96, and 168 hours and colony stimulating activity (CSA) assayed against light density non-adherent human marrow cells using double layer agar-culture system. CSA was maximum at 72 and 96 hours followed by an invariable decline at 168 hours' incubation. The optimal concentrations releasing maximum CSA varied for each agent. CM prepared with higher concentrations were less active. CM prepared in the presence of Pyran had no CSA. Comparisons of the maximally released CSA by the optimal concentrations of these agents revealed BCG and MER to be the most active. The CSA elaborated by UF cells was more than the total combined activity from separately incubated Ad and N-Ad cells. Re-addition studies revealed that almost full CSA could be recovered when Ad and N-Ad cells were incubated together at a ratio of 1:3. Different immunoadjuvants have a differing capacity to elaborate CSA from human marrow cells and each has an optimal concentration for maximum CSA release. This may require a cell-cell and/or humoral interaction(s) between Ad and N-Ad cells.

Adjuvants, Immunologic↗