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Biomedical subjects

S Gulati

Publications and source records attributed to S Gulati.

At least 163 records · Page 9Linked to original sources
PubMed1989

Total lymphoid irradiation, high-dose chemotherapy and autologous bone marrow transplantation for chemotherapy-resistant Hodgkin's disease.

Seventeen patients with advanced stage Hodgkin's disease who relapsed or failed to respond to multiple regimens of combination chemotherapy (mostly Mechlorethamine, Vincristine, Procarbarzine, Prednisone and Adriamycin, Bleomycin, Vinblastine, Dacarbazine) were treated with accelerated hyperfractionated total lymphoid irradiation (TLI) and high-dose chemotherapy followed by autologous bone marrow transplantation (AuBMT). Candidates for the protocol did not have prior radiation therapy and had no evidence of bone marrow involvement. Their bone marrow was initially harvested and cryopreserved. The treatment protocol consisted of reinduction with conventional doses of combination chemotherapy followed by boost local field irradiation to areas of residual disease (1500 cGy within 5 days) and total lymphoid irradiation (2004 cGy given in 12 fractions of 167 cGy each t.i.d. delivered within 4 days). The patients were treated with Etoposide (250 mg/m2/day I.V. X 3 days) and high-dose Cyclophosphamide (60 mg/kg/day I.V. X 2 days). Cryopreserved (unpurged) autologous bone marrow was infused 48 hr after completion of chemotherapy. Of the 17 patients treated, four were in relapse and 13 refractory to multiple regimens of combination chemotherapy. Four patients died during the immediate peritransplant period (2--septicemia, 2--pulmonary complications). Of the 13 surviving patients, 12 entered a complete remission and one had a partial remission and died of disease 6 months later. One patient relapsed 5 months after treatment and is currently alive with disease. Eleven patients (65%) are alive with no evidence of disease 4-35 months (median 20 months) following completion of therapy. Treatment with this protocol results in a high rate of complete remission and a potential for long-term disease-free survival in previously unirradiated patients with advanced stage refractory or relapsed Hodgkin's disease who have exhausted conventional modes of chemotherapy.

Adult↗
PubMed1989

Immunophenotypic demonstration of two natural killer surface markers, H25 and H366, on fresh human leukemic cells.

Using a modified alkaline-phosphatase/antialkaline-phosphatase method for phenotyping fresh human leukemias, we could demonstrate peripheral blood and bone marrow-derived blast cells to specifically react with two monoclonal antibodies (MoAbs), H25 and H366, previously shown to recognize natural killer cells, activated T lymphocytes and a proportion of normal hematopoietic precursor cells. MoAbs H25 and H366 were found to identify the majority of leukemic cells in patients presenting with T-ALL, LGL leukemia, pre-B-ALL, CML, and AML, respectively.

Animals↗
PubMed1989

Analysis of the individual and combined reactivities of monoclonal antibodies H25, H366, and MY9 with normal progenitor cells and blast cells from patients with acute myeloblastic leukemia.

Recently we reported that two monoclonal antibodies (MoAbs), H25 and H366, which react with human natural killer cells and monocytes, also react with normal in vitro colony-forming cells including granulocyte-monocyte colony-forming units (CFU-GM), erythroid burst-forming units (BFU-E), and erythroid colony-forming units and with leukemic blasts in preliminary testing of cells from patients with myeloid leukemias and T cell acute lymphocytic leukemia. In the present studies we examined the reactivities of MoAbs H25, H366, and MY9 (singly or combined) with the total leukemic cell population and the leukemic clonogenic cells (L-CFC) from 28 patients with acute myeloblastic leukemia. Using cytofluorography, we found the extent of expression of antigen H25 comparable to MY9 in the majority of patients, and both were more highly expressed than antigen H366. Incubation with H25 and H366 MoAbs simultaneously did not increase the number of positive cells over that seen when stained with H25 alone; however, the amount of antibody fluorescence intensity (FI) was increased. Leukemic cells simultaneously stained with MoAbs H25, H366, and MY9 displayed the highest number of positive cells and FI. Using magnetic beads coated with sheep anti-mouse IgG for depleting antibody-binding cells, greater than or equal to 90% of L-CFC were depleted by a combination of H25 and H366 MoAbs in 76% of AML cases tested as compared to 41% of the cases with MoAb MY9. Using a MoAb cocktail of H25, H366, and MY9, greater than or equal to 90% of L-CFC were depleted in 94% of cases tested, and greater than or equal to 99% of L-CFC were removed in 76% of the cases. Using the same depletion methods for normal bone marrow cells, a combination of anti-H25 and anti-H366 removed 90%, 98%, and 84% of CFU-GM, BFU-E, and multipotent colony-forming units (CFU-GEM), respectively, whereas the cocktail of H25, H366, and MY9 MoAbs removed 98%, 99.5%, and 97% of CFU-GM, BFU-E, and CFU-GEM, respectively. Incubation of H25 and H366-depleted bone marrow cells for 2 weeks in the presence of irradiated adherent cell layers from long-term marrow cultures generated CFU-GM and some BFU-E, as did H25, H366, and MY9-depleted marrow cells, although to a much lesser extent. Based on the overall data, combinations of H25, H366, and MY9 MoAbs and immunomagnetic beads conceivably might have therapeutic potential for ex vivo elimination of leukemic cells from AML remission marrows prior to autologous transplantation.

Adult↗
PubMed1988

The effect of high energy shock waves (HESW) on human bone marrow.

The effect of High energy shock waves (HESW) on the viability and proliferation of normal human bone marrow cells was evaluated. A dose dependent increase in cytotoxicity with an increase in the number of HESW was demonstrated. In general 700 HESW immediately reduced the cell viability of bone marrow cells by 50%. The CFU-GM assay provides a method to evaluate the effect of HESW on the proliferative capacity of bone marrow. Following HESW treatment the colony forming ability of trypan blue excluding cells also felt in a dose dependent fashion, but some variation in sensitivity was noted. By comparing the sensitivity of various cells, the cells of normal human bone marrow were felt to be less sensitive to HESW effects than those of other tissue cultured cells or malignant cell lines.

Bone Marrow↗
PubMed1988

Improved survival of poor prognosis diffuse histiocytic (large cell) lymphoma managed with sequential induction chemotherapy, "boost" radiation therapy, and autologous bone marrow transplantation.

From 1981 to 1985, 33 patients with the diagnosis of diffuse histiocytic (large cell) lymphoma (DHL) with a poor prognosis received induction multi-drug chemotherapy followed by autologous marrow cryopreservation. Thirty patients who had residual disease after chemotherapy were given "boost" irradiation to these sites, followed immediately by hyperfractionated total body irradiation, 1320 to 1375 cGy in 11 fractions over 4 days, then cyclophosphamide (60 mg/kg/d) for 2 days. All patients received an autologous bone marrow transplant (ABMT), with 15 patients receiving marrow purged with 4-hydroperoxycyclophosphamide. Patients were transplanted either as part of a planned induction-transplant approach (Group I), or as salvage after relapse on the same induction regimen (Group II), or other conventional chemotherapy regimens (Group III). In the entire group, 16 of 33 patients (48%) are alive free of lymphoma with a median follow-up of 32 months (11 to 53 mo). Actuarial (Kaplan-Meier) survival is 51% at 2 years and 46% at 3 years, with only 1 patient dying after 2 years out of 11 at risk. Eight patients (24%) succumbed to early treatment related complications. Nine patients (27%) died from relapse. Patients receiving ABMT as planned sequential therapy post-induction (Group I) did significantly better than patients given ABMT as salvage therapy after relapse on prior chemotherapy (Groups II and III) and better than the historical group of patients treated with chemotherapy alone. At 2 years, the survival in Group I is 79% versus 0% for Group II versus 48% for Group III. Historically, this group of high risk patients had a 2-year disease-free survival of 20% or less with chemotherapy alone.

Adolescent↗
PubMed1988

Molecular aspects, physiological function, and clinical significance of metallothioneins.

Metallothioneins (MTs) are well-characterized low molecular weight, heat-stable cytosolic proteins with exceptional high content of cysteinyl sulfur and are known to bind heavy metals like cadmium (Cd), zinc (Zn), and copper (Cu). Since these proteins are induced on exposure to heavy metals, it is now accepted that they have a detoxifying role during heavy metal toxicity. It has also been suggested that the primary function of Mt is in the homeostasis of the essential metals Zn and Cu. Recently, a role MT in selenium metabolism in primates has been established. Further, MT has gained considerable importance in the clinical disorders related to trace metal metabolism.

Amino Acid Sequence↗
PubMed1988

Elimination of myeloma cells from bone marrow by using monoclonal antibodies and magnetic immunobeads.

The efficacy of immunomagnetic beads to purge human myeloma cells from bone marrow ex vivo was evaluated. The optimal conditions for purging were studied first by using three myeloma cell lines: RPMI-8226, SKO-007, and SKMM-2. Myeloma cells labeled with the vital fluorescent dye Hoechst 33342 were admixed with normal bone marrow cells, and two monoclonal antibodies reactive with the myeloma cells (PCA-1 and BL-3) were added alone or in combination with the cells. Magnetic beads coated with goat antimouse immunoglobulin G were then added, and the tumor cells to which beads were attached were separated from the mixture with a magnet. The efficacy of tumor cell removal was dependent on the bead-to-tumor ratio; a ratio of more than 500 was optimal in the presence of excess normal marrow cells. The combination of monoclonal antibodies PCA-1 and BL-3 increased the tumor cell removal as compared with either antibody alone. Two cycles of treatment were more effective than one cycle was. Under optimal conditions, 2.3 to 4 logs of tumor cells could be removed from the mixture containing 10% myeloma cells without a significant loss of normal hematopoietic progenitors as measured by CFU-GM, CFU-GEM, and BFU-E. When the efficacy of this procedure was tested on fresh bone marrow from patients with multiple myeloma (MM) by using the combination of PCA-1, BL-3, and J-5, 1.6 to 2.5 logs of tumor cells could be removed by one cycle of treatment, even from marrows containing less than 10% myeloma cells. These observations support the use of monoclonal antibody combinations and immunobeads as a reliable and nontoxic method to eliminate contaminating myeloma cells ex vivo in preparation for autologous bone marrow transplantation in patients with MM.

Antibodies, Monoclonal↗
PubMed1987

Comparative cytotoxicity of various drug combinations for human leukemic cells and normal hematopoietic precursors.

The development of suitable methods for purging the malignant cells contaminating the bone marrow of patients with cancer may offer a better chance of success for autologous bone marrow transplantation. In this paper, we further describe our efforts at purging acute myelogenous leukemia cells. HL-60, a promyelocytic leukemia cell line, was used as a model. 4-Hydroperoxycyclophosphamide (4-HC), VP-16-213 (VP-16), and Adriamycin were used alone or in combination to develop the best method to purge HL-60 cells. The cytotoxicity of 29.2 micrograms/ml (100 microM) of 4-HC was 99.8 +/- 0.12% (SD) on HL-60 cells and 82.5% on colony forming units-granulocyte, macrophage. Ninety-nine % of HL-60 cells and 72.7% of colony forming units-granulocyte, macrophage were inhibited by VP-16 at a concentration of 25 micrograms/ml (42.5 microM). The cytotoxicity of 1.5 micrograms/ml (2.76 microM) of Adriamycin on HL-60 cells was 98.6 +/- 0.8% and inhibited colony forming units-granulocyte, macrophage by 50.8%. The cytotoxicity and interactions of any two drug combinations at different combination ratios and the different effect levels were quantitatively determined by median effect plot and the multiple drug effect equation (T-C. Chou and P. Talalay. Adv. Enzyme Regul. 22: 27-55, 1984). The combination of 4-HC and VP-16 at a 4-HC:VP-16 drug ratio of 1:0.342 was found to be the best for selective toxicity towards HL-60 cells and was superior to the 4-HC-Adriamycin or VP-16 Adriamycin combination for usefulness in purging bone marrow.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1987

Isolation and characterization of a metallothionein-like protein from monkey brain.

A cadmium-binding protein from monkey brain has been isolated, purified and characterized. The absorption spectrum of this protein indicates the presence of Cu-Zn thionein in the normal monkey brain which has a strong affinity to bind cadmium. On cadmium exposure the protein sequestered most of the cadmium which entered the brain. The apparent molecular weight of this protein as determined on a gel filtration column calibrated with marker proteins has been found to be in the range of 11,500-12,000 Da. The ratio of absorbance at 254 nm/280 nm is more than 1 indicating the presence of cadmium-mercaptide bonds, which was further confirmed by the presence of 15 cysteine residues. Polyacrylamide gel electrophoresis of the protein shows 3 bands indicating the presence of 3 isometallothionein forms. Unlike hepatic or renal thioneins, the cadmium-binding protein in brain is not inducible following administration of cadmium. However, when antibodies raised against hepatic metallothionein were cross-reacted with brain Cd-binding protein, a line of identity was observed, indicating the 2 proteins are immunologically identical and share a high degree of structural similarity.

Animals↗
PubMed1987

Specificity of antibodies against Neisseria gonorrhoeae that stimulate neutrophil chemotaxis. Role of antibodies directed against lipooligosaccharides.

Five strains each of Neisseria gonorrhoeae sensitive or resistant to complement (C) dependent killing by normal human serum (NHS) were examined for their ability to stimulate chemotaxis of polymorphonuclear leukocytes (PMNs) after preincubation with NHS; or IgM or IgG derived from NHS. Serum-sensitive N. gonorrhoeae stimulated C-dependent chemotaxis when opsonized with IgM, but not IgG, however, serum-resistant strains, taken as a whole, failed to promote chemotaxis when opsonized with either isotype. IgM titers in NHS against lipooligosaccharide (LOS) antigens from individual serum-sensitive, but not serum-resistant strains, correlated with the magnitude of chemotaxis generated by the corresponding opsonized strains (r = 0.99). Western blots demonstrated that IgM and IgG from NHS recognized different antigenic determinants on LOS from serum-sensitive gonococci. IgM from NHS immunopurified against serum-sensitive LOS accounted for two-thirds of the chemotaxis promoting activity present in whole serum. IgG titers in NHS against LOS antigens from individual serum-resistant strains also correlated with magnitude of chemotaxis generated by the corresponding opsonized strains (r = 0.87), although most opsonized serum-resistant strains did not generate significantly higher magnitudes of chemotaxis than controls. In contrast, a serum-resistant isolate from a patient with disseminated gonococcal infection (DGI) stimulated chemotaxis when opsonized with IgG obtained from the patient's convalescent serum. By Western blot, convalescent IgG antibody recognized an additional determinant on serum-resistant LOS not seen by normal IgG.

Adult↗
PubMed1987

Interleukin-2- and mitogen-activated NK-like killer cells from highly purified human peripheral blood T cell (CD3+ N901-) cultures.

In this study, highly purified (HP) CD3-positive N901-negative T lymphocytes could be induced to become natural killer (NK)-like in culture in the presence of recombinant interleukin-2 (rIL-2) and phytohemagglutinin (PHA). Thus, purified CD3+ N901- T cells from fresh human peripheral blood were obtained by negative selection using an indirect panning technique. To ensure that T lymphocyte fractions were completely devoid of any detectable NK cells, two additional purification procedures were employed: incubation of post-pan T cells with the NK-cytotoxic lysomotropic agent L-leucinemethylester, and complement-mediated lysis using the NK cell specific NKH1a monoclonal antibody. Purity of CD3+ N901- cells could be confirmed by surface marker analysis, whereby two NK-associated antigens, N901 and H-25, were undetectable, while 94 +/- 1% of cells expressed the CD3 (Leu-4) antigen. On functional analysis, fresh HP CD3+ N901- cells exhibited no cytotoxic activity against the standard NK target K562. When HP NK-depleted T lymphocytes were cultured for 7 days in the presence of rIL-2 (100 U/ml), neither surface antigen expression nor cytotoxic activity against K562 changed significantly. However, significant cytotoxicity against K562 [18 +/- 5% specific lysis at 25:1 effector:target (E/T) ratio] could be induced when HP CD3+ N901- cells were grown for 7 days in the presence of rIL-2 and PHA (0.5% v/v). Concomitantly, antigens N901 and H-25 were found to be coexpressed on a minor proportion (22 +/- 16 and 22 +/- 6%, respectively) of CD3+ (88 +/- 2% on day 7) cells. Four-week long-term culture of HP NK-depleted T cells in the presence of rIL-2 and PHA yielded a continuous increase in cytotoxicity against K562 cells (0 up to 46% specific lysis at 25:1 E/T ratio). Of particular interest was the emergence of cytotoxicity against the NK-resistant Daudi cell target (15 +/- 8% specific lysis at 25:1 E/T ratio on day 21). Expression of antigens N901 and H-25 as well as CD3 remained essentially unchanged in long-term culture. In sorting experiments, the H-25+ cell fraction was significantly enriched for cytotoxicity against K562, when compared to both H-25- and unseparated cell fractions. In summary, our results suggest that a proportion of HP CD3+ N901- T lymphocytes may give rise to cells that exhibit NK-like functional and phenotypic properties.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1987

Activities of four purified growth factors on highly enriched human hematopoietic progenitor cells.

The activities of four purified human growth factors: biosynthetic (recombinant) granulocyte-macrophage colony-stimulating factor (GM-CSF); recombinant erythroid-potentiating activity (EPA); natural and recombinant pluripoietin (Ppo); and natural pluripoietin alpha (Ppo alpha), were compared on the growth of hematopoietic colonies from enriched populations of human marrow and blood progenitor cells. Conditioned medium from the Mo T cell line (MoCM) was used as a standard positive control. We found that activities of GM-CSF and Ppo alpha on the growth of hematopoietic colonies were indistinguishable; Ppo alpha is now believed to be identical to GM-CSF. Both factors were able to promote the growth of colonies derived from subpopulations of CFU-GM, BFU-E, and CFU-GEM. Colonies derived from CFU-GM and CFU-GEM in cultures stimulated by GM-CSF and Ppo alpha were much smaller than in cultures stimulated by MoCM. In contrast to previous reports in which less highly enriched progenitors were used as target cells, Ppo had no detectable activity on the growth of colonies derived from BFU-E or CFU-GEM but promoted the growth of a subpopulation of CFU-GM derived colonies. Ppo is now recognized to be identical to G-CSF. The GM colonies in cultures stimulated by G-CSF (Ppo) were much smaller than in cultures stimulated by MoCM. EPA had no detectable activity on either the size or number of colonies derived from CFU-GM, BFU-E, or CFU-GEM. Results from experiments using target cell populations of marrow fractions separated by velocity sedimentation and marrow populations following freezing suggested that GM-CSF (Ppo alpha) and G-CSF (Ppo) primarily affect the growth of relatively mature subpopulations of progenitor cells. It is clear from these results that additional factor(s) are present in MoCM that are necessary to stimulate CFU-GM, BFU-E, and CFU-GEM maximally in vitro.

Bone Marrow↗