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S C Gulati

Publications and source records attributed to S C Gulati.

At least 37 records · Page 2Linked to original sources
PubMed1994

Newer options for treating drug-resistant (MDR+) cancer cells using photoradiation therapy.

Emergence of drug resistance with conventional cytotoxic therapy is a major challenge towards the curability of many cancers, especially in patients undergoing autologous BMT with ex-vivo purged hematopoietic support. We have explored the potential role of photoradiation therapy in purging hematopoietic stem cells of various hematological malignancies. Benzoporphyrin derivative, monoacid ring A (BPD-MA), dihematoporphyrin ether (DHE), and MC-540 were evaluated for the "ex-vivo" purging of residual tumor cells from autologous bone marrow (BM) grafts. BPD-MA and DHE photosensitizing activity was tested against two human large cell lymphoma cell lines and colony forming-unit leukemia (CFU-L) derived from patients with acute myelogenous leukemia (AML). In mixing experiments four log elimination of tumor cell lines was observed after 1 hr of incubation with BPD-MA or DHE followed by white light exposure. By comparison, using the same concentration of BPD-MA or DHE, the mean recovery of normal BM progenitors was 4-5.2% for granulocyte-macrophage colony forming unit (CFU-GM) and 5-9.8% for burst forming unit erythroid (BFU-E). The T lymphoblastic leukemia cell line CEM and its vinblastine (VBL)-resistant subline CEM/VBL100, along with the acute promyelocyte leukemia cell line HL-60 and its vincristine (VCR)-resistant subline HL-60/VCR, were also tested. Our results demonstrated the preferential cytotoxicity of BPD-MA and DHE toward neoplastic cell lines and CFU-L from AML patients. In addition, DHE was slightly more effective in purging tumor cells expressing the p-170 glycoprotein.(ABSTRACT TRUNCATED AT 250 WORDS)

Bone Marrow Purging↗
PubMed1994

Combination of hematopoietic growth factors containing IL-3 induce acute myeloid leukemia cell sensitization to cycle specific and cycle non-specific drugs.

Laboratory studies have suggested that hematopoietic growth factors (GF), combined with cytosine-arabinoside (Ara-C) can enhance cytotoxic effects of this agent against acute myeloid leukemia (AML) cells. While clinical trials based on this growth factor/chemotherapy combination (GF/CT) are progressing with discordant results, further information regarding the underlying mechanisms have been reported supporting this rationale and requiring additional investigation. To assess the role of cytokinetic changes in the GF/CT strategy and to evaluate if chemotherapeutic agents regimens other than Ara-C, when combined with GF, can enhance their cytotoxic effects, we have primed AML blasts with two cytokine combinations and then exposed these cells to the S-phase specific agent Ara-C as well as to the phase non-specific drug daunorubicin (DNR) and to the alkylating agent 4-hydroperoxycyclophosphamide (4-HC). The two cytokine combinations used for priming AML blasts were: (i) interleukin-3 (IL-3) + granulocyte-macrophage colony-stimulating factor (GM-CSF) + granulocyte colony-stimulating factor (G-CSF); and (ii) GM + G-CSF. Cytokinetic analysis in ten AML samples and clonogenic growth of leukemic colonies (CFU-L) in methylcellulose were used to detect proliferative and cytotoxic effects on AML samples. We report that in AML clonogenic cell growth can be stimulated by cytokines in 50% of the samples (4/8), and that Ara-C sensitization clearly occurs in two out of these four samples. Among the different cytokine combinations tested, the one containing IL-3 was the most effective through a cytokinetic mechanism consistent with recruitment (averaged G0 decrease p = 0.04; S-phase increase p = 0.005). Furthermore we observed increased cytotoxicity also to the phase non-specific drugs DNR and 4-HC, which may be mediated by other mechanisms recently described. We conclude that GF/CT combinations may also be beneficial in regimens containing drugs other than Ara-C, used for AML treatment, including bone marrow transplantation conditioning regimens.

Antineoplastic Agents↗
PubMed1994

Positive selection of hematopoietic CD34+ stem cells provides 'indirect purging' of CD34- lymphoid cells and the purging efficiency is increased by anti-CD2 and anti-CD30 immunotoxins.

Human CD34+ hematopoietic cells were purified using the avidin-biotin immunoabsorption technique. The selected population showed 78.6 +/- 3% CD34+ cells and the overall recovery of CD34+ cells, CFU-GM and BFU-E from the starting population was 34 +/- 5%, 71 +/- 4% and 67 +/- 2%, respectively. Hematopoietic progenitor cell purification also resulted in 3 log of normal T cell depletion from the bone marrow (BM) by immunofluorescence analysis. Moreover, when unseparated BM cells were mixed with the CD34- lymphoma cell lines D430B and Raji, the removal of greater than 3 log of tumor cells from the enriched CD34+ cell fraction was demonstrated. To increase the neoplastic cell purging, several immunotoxins (IT) containing the ribosome-inactivating protein (RIP) saporin and directed toward the lymphoid-associated antigens CD30 and CD2 were prepared. Our experiments showed only a minimal toxicity of the immunoconjugates on colony-forming cells (CFC) derived from purified CD34+ cells. Conversely, all the ITs were very effective in inhibiting protein synthesis and growth of normal and neoplastic lymphoid cells. Further experiments demonstrated that the sequential combination of CD34+ cells purification and IT treatment resulted in 5 or more log of tumor cell purging with no additional loss of BM progenitor cells.

Antigens, CD↗
PubMed1994

Is bone marrow purging proving to be of value?

Although the role of hematopoietic stem-cell transplantation (HSCT) in cancer treatment is rapidly expanding, decreasing the side effects of stem-cell infusion is a major challenge. Cancer cells present in the stem-cell collection can cause relapse after autologous transplantation. In allogeneic transplantation. T lymphocytes contribute to graft-versus-host disease. Various methods of purging have been used to remove these unwanted cells, and there is some evidence that such manipulations are clinically useful. Nevertheless, the inability to detect minimal disease makes it difficult to determine whether relapse is caused by incomplete disease eradication in the patient or by the infused cells. This makes it hard to justify the clinical benefit of ex vivo purging. Researchers can focus on this issue by designing studies with minimal variation in other factors that affect the success of stem-cell transplantation.

Bone Marrow Purging↗
PubMed1993

Phase II trial of high-dose carboplatin and etoposide with autologous bone marrow transplantation in first-line therapy for patients with poor-risk germ cell tumors.

BACKGROUND: Between 20% and 30% of patients with advanced germ cell tumors (GCTs) fail to have durable complete response to conventional cisplatin-based induction chemotherapy. However, third-line therapy with high-dose carboplatin and etoposide plus autologous bone marrow transplantation (AuBMT) has induced durable complete response in 10%-20% of patients with cisplatin-resistant GCT. PURPOSE: We conducted a phase II trial of first-line therapy that included high-dose carboplatin and etoposide plus AuBMT in untreated men with advanced GCTs and unfavorable prognosis (i.e., "poor-risk" patients). METHODS: Twenty-eight patients were treated with a conventional-dose, cisplatin-containing regimen (VAB-6 [cisplatin, vinblastine, bleomycin, cyclophosphamide, dactinomycin]) with or without high-dose carboplatin (1500 mg/m2) and etoposide (1200 mg/m2) plus AuBMT. Twenty-two of these patients were selected for treatment with two cycles of high-dose carboplatin and etoposide plus AuBMT when reduced clearance of serum tumor markers (alpha-fetoprotein [AFP] or human chorionic gonadotropin [HCG]), as evidenced by prolonged half-life (> 7 days for AFP and > 3 days for HCG), was observed after two cycles of conventional treatment. RESULTS: Fifteen (56%) of 27 patients considered assessable for response achieved a complete response (12 treated with high-dose chemotherapy plus AuBMT). Sixteen (57%) are alive; 13 (46%) are free of disease at a median follow-up of 31.2 months. For 36 cycles of high-dose chemotherapy, the median duration from bone marrow infusion until a granulocyte count of 0.5/mm3 and a platelet count of 50,000/mm3 was 16 days (range, 7-41 days and 8-30 days, respectively). Analysis showed a trend toward improved survival (P = .07) in patients treated with high-dose chemotherapy in this study, compared with 68 poor-risk patients with GCT treated with conventional-dose therapy alone in two earlier studies. Toxicity was not cumulative, and recovery of blood counts after AuBMT was generally rapid. CONCLUSIONS: Inclusion of high-dose carboplatin-containing chemotherapy in treatment of poor-risk GCT patients is feasible when serum tumor marker half-life is used to predict resistance to standard cisplatin-based therapy. High-dose therapy in this setting was well tolerated. IMPLICATIONS: Early use of a dose-intensive regimen may increase survival compared with conventional-dose therapy alone. Further studies with standard induction therapy and intensive high-dose therapy using hematopoietic growth factor support are warranted, followed by a randomized trial comparing this strategy with standard therapy.

Adolescent↗
PubMed1993

Phase I trial with pharmacokinetic analyses of high-dose carboplatin, etoposide, and cyclophosphamide with autologous bone marrow transplantation in patients with refractory germ cell tumors.

Thirty patients with cisplatin-refractory germ cell tumor were treated with high-dose carboplatin, etoposide, and cyclophosphamide and autologous bone marrow transplantation. The total dose of carboplatin was 1500 mg/m2, etoposide 1200 mg/m2, and cyclophosphamide was increased by increments from 60 to 150 mg/kg. Twenty-five cycles of treatment, given to 17 patients, did not include granulocyte-colony stimulating factor (G-CSF). Nineteen cycles of high-dose chemotherapy, given to 13 patients at the 2 highest dose levels of cyclophosphamide, included G-CSF. The dose of cyclophosphamide was escalated to 150 mg/kg/cycle without prohibitive toxicity. The use of G-CSF resulted in a shorter duration of neutropenia (P = 0.07); the median number of days until the recovery of an absolute granulocyte count > 0.5 was 25 without G-CSF and 14 with G-CSF. The most frequent nonhematological toxicity was hepatic, and there were 2 (7%) treatment-related deaths. Thirteen (43%) patients achieved a complete response, and 8 are alive and free of disease (27%); 7 are in continuous complete response (23%), and 1 after resection of a solitary site of disease following a relapse after high-dose chemotherapy. Five patients had pharmacology studies performed to determine the area under the curve (AUC) of free and total platinum, carboplatin, etoposide, cyclophosphamide, and phosphoramide mustard. There was a decrease in the AUC of cyclophosphamide and an increase in the AUC of phosphoramide mustard, the "active" metabolite, with successive days of treatment. The interpatient variability of the AUC of cyclophosphamide/phosphoramide mustard that was demonstrated was most likely a result of each individual's metabolic capacity. The measured AUC of carboplatin and/or free platinum closely approximated the predicted AUC of carboplatin calculated by renal function in 3 of the 5 patients. In summary, cyclophosphamide administered at a dose of 50 mg/kg x 3 days was achieved with acceptable toxicity, and no further dose escalation is planned. High-dose carboplatin, etoposide, and cyclophosphamide achieved a 23% continuous complete response proportion (27% alive, free of disease) when used as third-line therapy in germ cell tumor patients refractory to cisplatin + ifosfamide-based chemotherapy. Ongoing studies are addressing the role of high-dose carboplatin-containing chemotherapy in previously untreated patients with poor prognostic features or as a part of first-line salvage.

Adolescent↗
PubMed1993

Dye-mediated photolysis is capable of eliminating drug-resistant (MDR+) tumor cells.

We evaluated the potential role of photoradiation therapy with a benzoporphyrin derivative, monoacid ring A (BPD-MA), and dihematoporphyrin ether (DHE), for the ex vivo purging of residual tumor cells from autologous bone marrow (BM) grafts. BPD-MA and DHE photosensitizing activity was tested against two human large-cell lymphoma cell lines and colony-forming unit-leukemia (CFU-L) derived from patients with acute myelogenous leukemia (AML). In mixing experiments, 4-log elimination of tumor cell lines was observed after 1 hour of incubation with 75 ng/mL of BPD-MA or 30 minutes of treatment with 12.5 micrograms/mL of DHE followed by white light exposure. By comparison, using the same concentration of BPD-MA, the mean recovery of normal BM progenitors was 4% +/- 0.8% (mean +/- SD) for granulocyte-macrophage colony-forming unit (CFU-GM) and 5% +/- 0.8% for burst-forming unit-erythroid (BFU-E). Similarly, DHE treatment resulted in the recovery of 5.2% +/- 2% and 9.8% +/- 3% of CFU-GM and BFU-E, respectively. Furthermore, equivalently cytotoxic concentrations of both DHE and BPD-MA and light were found not to kill normal pluripotent stem cells in BM, as demonstrated by their survival in two-step long-term marrow culture at levels equal to untreated controls. The T-lymphoblastic leukemia cell line CEM and its vinblastine (VBL)-resistant subline CEM/VBL, along with the acute promyelocyte leukemia cell line HL-60 and its vincristine (VCR)-resistant subline HL-60/VCR, were also tested. BPD-MA at 75 ng/mL was able to provide a greater than 4-log elimination of the drug-sensitive cell lines, but only a 34% and 55% decrease of the drug-resistant HL-60/VCR and CEM/VBL cell lines, respectively. On the contrary, 12.5 micrograms/mL of DHE reduced the clonogenic growth of all the cell lines by more than 4 logs. Further experiments demonstrated decreased uptake of both BPD-MA and DHE by the resistant cell lines. However, all the cell lines took up more DHE than BPD-MA under similar experimental conditions. Our results demonstrate the preferential cytotoxicity of BPD-MA and DHE toward neoplastic cell lines and CFU-L from AML patients. In addition, DHE was slightly more effective in purging tumor cells expressing the p-170 glycoprotein. These results suggest that photoradiation with DHE would be useful for in vitro purging of residual drug-resistant leukemia and lymphoma cells.

Bone Marrow↗
PubMed1993

Effect of stem cell factor (c-kit ligand), granulocyte-macrophage colony stimulating factor and interleukin 3 on hematopoietic progenitors in human long-term bone marrow cultures.

In this paper we attempt to improve upon the methods of hematopoietic stem cell expansion. We evaluate the effects of recombinant human stem cell factor (SCF or c-kit ligand) alone and also in combination with recombinant human granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin 3 (IL-3), on cell proliferation and differentiation in human long term bone marrow cultures (LTBMC). Weekly addition of 5 ng/ml of SCF with 25% serum containing media resulted in increased recovery of total nonadherent cells, granulocyte-macrophage colony forming units (CFU-GM), and burst-forming units erythroid (BFU-E) at week 1, but the number of bone marrow (BM) progenitor cells fell below the level of untreated control cultures at weeks 3 (BFU-E) and 4 (CFU-GM). At week 8, when the cultures were terminated, the CFU-GM recovery was markedly reduced in flasks supplemented with SCF compared with the controls (p < 0.002). Moreover, SCF treatment induced the early disappearance of BFU-E. When LTBMC were supplemented with the combination of SCF plus GM-CSF (100 U/ml) and IL-3 (5 ng/ml), synergistic activity of the CSFs was observed at week 1. The number of BM colony forming cells (CFC) rapidly declined below the level of growth factor-free controls, leading to the early exhaustion of the culture when SCF was combined with GM-CSF. By comparison, GM-CSF and IL-3 alone induced a statistically significant increase above the controls (no growth factor) in the number of nonadherent cell colonies of CFU-GM and BFU-E. Analysis of adherent layer cells from cultures supplemented with SCF showed increased cellularity, no adipogenesis, and early disappearance of myeloid progenitors while the percentage of CFU-GM in S phase, assessed by cytosine arabinoside (Ara-C) suicide assay, was 9.2 +/- 5% SD versus 27.7 +/- 10% SD in control (no growth factor) samples (p < 0.01). SCF increased the number of fibroblast colony forming units (CFU-F) and also showed a synergistic activity (9.6-fold increase) when combined with IL-3. These findings suggest that SCF, GM-CSF and IL-3 exert their activity on different cell populations within the hematopoietic system. Further investigations are needed to optimize the use of SCF in supporting hematopoiesis.

Bone Marrow↗
PubMed1993

T cells and monocytes regulate the generation and functional activity of natural killer-derived lymphokine-activated killer cells.

The lymphokine-activated killer (LAK) phenomenon is generally referred to as nonspecific, i.e., major histocompatibility complex (MHC)-unrestricted cytotoxicity against tumor cells generated by ex vivo culture of human peripheral blood lymphocytes with interleukin 2 (IL-2). In this study, we selectively purified and depleted cell subpopulations such as natural killer (NK) cells, T-lymphocytes and monocytes from fresh human peripheral blood by negative selection. While highly purified NK cells could be induced to acquire potent LAK activity in five-day culture with IL-2, the presence of T-lymphocytes and monocytes in NK cultures was needed in order to induce a significant expansion of cytotoxic effector cells over the culture period. Neither T cells nor monocytes by themselves were able to generate LAK cells in a standard five-day IL-2 culture. However, when added to highly purified NK cells prior to IL-2 incubation, a proportion of CD3+ T-lymphocytes was found to gain LAK-like killing activity. Monocytes, when cultured with IL-2 in the presence of NK cells and T-lymphocytes, did not appear to acquire LAK activity but were able to induce a dramatic increase in cytotoxic lymphocyte recovery after five days with IL-2. In summary, we could demonstrate that peripheral blood T-lymphocytes and monocytes are potent regulators of NK-dependent lymphokine (IL-2)-activated killing.

Cell Communication↗
PubMed1993

Rationale for purging in autologous stem cell transplantation.

The success of autologous stem cell transplantation using bone marrow or peripheral blood stem cells depends not only on in vivo irradication of the disease by cytotoxic therapy but also on complete hematopoietic engraftment with no risk of relapse from the infused cells. Various methods are available for removing (purging) such contaminants. Purging techniques were developed by use of various in vitro models utilizing cell lines and fresh cancer cells. Once effective conditions were developed, they were advanced onto clinical trials. Various approaches for purging have been used. Subgroups of leukemia and lymphoma have now shown clinical benefit by the use of purged stem cells. Emphasis is now being placed on utilizing the information already obtained by the pre-clinical investigators on designing better clinical trials.

Animals↗
PubMed1993

Harvesting bone marrow in an outpatient setting using newer anesthetic agents.

PURPOSE: To evaluate the results of outpatient bone marrow harvest (BMH). PATIENTS AND METHODS: Seventy-two adult patients with various malignancies had 79 BMH procedures performed for future autologous bone marrow transplantation (BMT) in our institution's outpatient surgical facility. All patients were evaluated and educated before the procedure. Newer anesthetic agents specifically developed to have shorter half-lives, more rapid recovery from general anesthesia, and fewer unpleasant side effects were chosen. Propofol was used for induction of anesthesia in 76 patients, the other three were induced with sodium pentothal. The blood volume removed was replaced by colloid (6% hydroxyethyl starch). Also, a new parenteral nonnarcotic pain medication, ketoroloc, was used during the last part of general anesthesia to help with expected postoperative pain in 76 patients. RESULTS: BMH took 111 +/- 24 minutes and patients were in postanesthesia care unit (PACU) for 220 +/- 72 minutes before being sent home with a companion and Tylenol with codeine (acetaminophen with codeine; McNeil Pharmaceutical, Spring House, PA). PACU complications were minor and included transient mild dizziness (7.6%), vomiting (3.8%), and fever (2.6%). No life-threatening complication was observed. Only one patient was hospitalized for observation (fever) and then sent home. Seventy-five patients (94.9%) were contacted at home by the hospital nursing staff the day following the procedure. Five (6.7%) complained of nausea or vomiting, and four (5.3%) developed fever at home (temperature, 37.2 to 38.3 degrees C). Only 36% of patients actually took oral narcotic pain medication at home. CONCLUSION: Autologous BMH (AuBMH) is a safe outpatient procedure with minimal side effects when newer anesthetic agents are used.

Adolescent↗
PubMed1993

Accelerated hyperfractionated total-lymphoid irradiation, high-dose chemotherapy, and autologous bone marrow transplantation for refractory and relapsing patients with Hodgkin's disease.

PURPOSE: To evaluate the feasibility and therapeutic effect of accelerated hyperfractionated total-lymphoid irradiation (TLI), high-dose chemotherapy, and autologous bone marrow transplantation (AuBMT) in patients with relapsing or chemotherapy-resistant Hodgkin's disease (HD). PATIENTS AND METHODS: Forty-seven patients with HD who either relapsed after chemotherapy (n = 19), or failed to respond (n = 28) to at least two regimens of combination chemotherapy were studied. No patient received prior radiation therapy (RT). Treatment started with reinduction with standard-dose chemotherapy, followed by involved-field irradiation (15 Gy) to areas of relapsed or persistent disease and TLI (20.04 Gy given in 1.67 Gy fractions three times per day for 4 days). Subsequently, patients received etoposide and high-dose cyclophosphamide, followed by infusion of unpurged autologous bone marrow. All surviving patients had a minimum follow-up duration of 1 year. The median follow-up duration for survivors was 40+ months, and the maximum follow-up duration was 80+ months. RESULTS: Of the 47 patients treated, eight (17%) died of toxicity during the peritransplant period. Twenty-nine of the remaining 39 assessable patients (74%) attained a complete response (CR), while 10 remained with residual disease and progressed early after AuBMT. Four of the CR patients (14%) relapsed and 25 patients remained alive and free of disease. The actuarial disease-free survival (DFS) rate for the entire group at 6.5 years was 50%. Patients who received the protocol for relapsing HD had a significantly better DFS rate (79%) compared with patients treated for continuous refractory disease (DFS, 33%; P < .03). CONCLUSION: Previously unirradiated patients with relapsing or chemotherapy-resistant HD who have exhausted conventional chemotherapy may still respond to an aggressive therapeutic approach consisting of accelerated hyperfractionated TLI, high-dose chemotherapy, and AuBMT rescue. This program offers a potential for long-term DFS to approximately one half of patients who would otherwise have a dismal prognosis with standard-dose salvage therapy.

Adolescent↗
PubMed1993

Improving the role of hematopoietic support for high-dose cytotoxic therapy.

Dose intensification of cytotoxic drugs is now being evaluated in several trials. Various methods are available to manage the hematopoietic toxicity. Hematopoietic growth factors can be used alone and/or in combination with hematopoietic stem cell rescue. Patients undergoing autologous stem cell transplantation (AuSCT) have their own bone marrow and/or peripheral blood used for hematopoietic engraftment. In several malignancies, the bone marrow is involved with tumor, and in such situations, the success of AuSCT may improve if hematopoietic elements are enriched (positive selection) or if contaminating cancer cells are purged by negative selection. In patients undergoing allogeneic bone marrow transplantation, T lymphocytes, from donor cells, contribute to the development of graft-versus-host disease (GVHD), which can result in major morbidity and mortality. The incidence of GVHD has decreased with selective purging of T lymphocytes, but further modifications are needed to improve hematopoietic engraftment. Methods for purging hematopoietic stem cells are discussed, with emphasis on the therapeutic role of purging. Growing stem cells from a small amount of bone marrow presents a new possibility. Furthermore, genetic engineering can enhance immune surveillance and decrease drug resistance. Analysis of the clinical trials utilizing various doses of cytotoxic therapy with proper methods of hematopoietic rescue will help avoid unnecessary dose escalation and help decide the optimum use of cancer treatment modalities.

Antineoplastic Agents↗