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Biomedical subjects

D L Longo

Publications and source records attributed to D L Longo.

At least 325 records · Page 18Linked to original sources
PubMed1990

Treatment of patients with aggressive lymphomas: an overview.

The treatment of aggressive lymphomas has progressed to the point that over 90% of the patients with localized disease, around 50% of the patients with advanced disease, and perhaps up to 25% of relapsing patients may enjoy long-term, disease-free survival. Several studies have documented that primary combination chemotherapy with or without involved-field radiation therapy is capable of curing 90% or more of the patients with clinically staged, localized disease. Results with primary radiation therapy in such patients are not nearly as good, even in those who undergo laparotomy staging. The management of advanced-stage disease is more controversial. Although combination chemotherapy is the treatment of choice, there is debate about whether the impressive results with the latest regimens, such as MACOP-B, COP-BLAM III, and ProMACE-CytaBOM, which appear to be curative for around 60% or more of advanced-stage patients, are really superior to CHOP, the most widely used program, which cures about 30% or so of the patients. A major idea that is guiding the development of new treatment programs is augmenting the dose intensity of the treatment. This notion is fueled not only by the demonstrated dose-response relationships that have been documented by Hryniuk and colleagues in other tumor types, such as cancers of the breast, ovary, and colon, but also by recent experience in the salvage therapy of relapsed aggressive lymphoma. Formerly a universally fatal disease, relapsed aggressive lymphoma now appears to be responsive to high-dose chemotherapy with or without radiation therapy followed by autologous or allogeneic bone marrow or peripheral blood stem cell reconstitution.(ABSTRACT TRUNCATED AT 250 WORDS)

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

Late complications of Hodgkin's disease management.

In the past several decades, Hodgkin's disease has been transformed from a uniformly fatal illness to one that can be treated with the expectation of long-term remission or cure in the majority of patients. Because patients now survive for long periods after curative intervention, various complications have been identified. The spectrum of complications following curative therapy is quite diverse and includes immunologic, cardiovascular, pulmonary, thyroid, and gonadal dysfunction. In addition, second malignant neoplasms in the form of acute leukemia as well as secondary solid tumors have now been documented to occur with increased frequency in patients cured of Hodgkin's disease.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

Lymphomas.

Explore the source record for details and available documents.

Hodgkin Disease↗
PubMed1989

Diffuse osteosclerosis in hairy cell leukemia.

We describe two patients with a new clinical pathologic syndrome of diffuse osteosclerosis in association with hairy cell leukemia. In both patients bone marrow biopsies could not be obtained due to extremely hard bones and inability to insert the biopsy needle; neither patient had a history of bony pain or fracture. The osteosclerotic process in one patient stabilized after successful treatment of her hairy cell leukemia with interferon alpha and deoxycoformycin suggesting that the osteosclerosis observed was related to the underlying malignant disease. Possible etiologic mechanisms are discussed.

Adult↗
PubMed1989

Interleukin-1 enhances survival of lethally irradiated mice treated with allogeneic bone marrow cells.

Interleukin-1 (IL-1) enhanced the capacity of allogeneic bone marrow (BM) cells to promote survival of mice given doses of radiation (1,200 to 1,350 cGy) that are significantly higher than those generally used for BM ablation (850 to 950 cGy). Three to five times greater numbers of lethally irradiated (1,200 to 1,350 cGy) C57B1/6 (H-2b) mice given 10(7) T-cell-depleted Balb/c (H-2d) BM cells survived over 6 weeks if also treated with a single intraperitoneal (IP) dose of 10 micrograms IL-1 20 hours before or from 1 to 3 hours after radiation. The spleens of these mice were reconstituted predominantly, but not exclusively, with donor cells (54% to 91%). Histologic examination of the epidermal and gastrointestinal tissues of mice surviving more than 6 weeks did not reveal any evidence of graft-versus-host (GVH) disease; however, since 10% to 43% of the mice died between days 30 and 46, the possibility of a GVH syndrome in these mice cannot be excluded. The spleen cells from irradiated mice given BM transplants and IL-1, which consisted of greater than or equal to 85% donor cells, were able to generate specific T-cell cytotoxic killing of unrelated allogeneic donor cells but were unreactive to target cells bearing either host or donor major histocompatibility complex (MHC) class I antigens. Thus, long-term mixed chimeric survivors were tolerant to recipient and donor alloantigens but exhibited immunologic competence. These results show that IL-1 promotes survival of lethally irradiated mice and that allogeneic hematopoietic cells in such animals develop tolerance to host MHC antigens. Although there are many unanswered questions, these data suggest that IL-1 may prove clinically useful in promoting BM engraftment.

Animals↗
PubMed1989

Enhanced therapeutic efficacy of an immunotoxin in combination with chemotherapy against an intraperitoneal human tumor xenograft in athymic mice.

A mouse IgG2b anti-pan carcinoma monoclonal antibody, NR-LU-10, was shown to bind homogeneously to ascites xenografts of both ovarian and colon carcinoma. Following linkage to a highly potent holotoxin, Pseudomonas exotoxin A (PE), NR-LU-10 demonstrated high potency and selectivity in vitro (ID50 = 100 pg/ml; elimination of greater than or equal to 4.5 logs of cells). The conjugate was evaluated for therapeutic efficacy against a human colon tumor (HT-29) transplantable in the peritoneal cavity of nude mice. Beginning 3 days after HT-29 injection, mice received either three or six i.p. injections of 0.5 micrograms of unconjugated NR-LU-10 or immunotoxin conjugate (NR-LU-10/PE) every other day. Mice that received three or six treatments of NR-LU-10 alone had median survival times (MSTs) of 39 and 40 days, respectively, which did not differ significantly from the MST observed for the untreated control groups (MST = 35 days). In contrast, treatment with three or six injections of 0.5 micrograms NR-LU-10/PE exhibited significantly increased MSTs (P = 0.002) of 50 and 60 days, respectively. Coinjection of unconjugated NR-LU-10 (20 micrograms) and 0.5 micrograms of NR-LU-10/PE blocked the therapeutic effect of the immunotoxin (MST = 33 days). The therapeutic efficacy of NR-LU-10/PE was further enhanced against HT-29 when administered i.p. during and after cytoreductive chemotherapy. The i.p. administration of 300 mg/lg of cyclophosphamide plus 100 mg/kg of the chemoprotective drug, WR-2721, 10 and 17 days posttumor cell inoculation induced a significant increase in MST from 36 days to 59 days (P = 0.002). Interestingly, groups of mice that received either two, four, or seven treatments of NR-LU-10/PE following cytoreductive therapy exhibited a further significant increase (P = 0.001) in MSTs of 89, 97, and 105 days, respectively. Therefore, the use of immunotoxin therapy following cytoreductive chemotherapy significantly prolonged survival time of mice bearing the HT-29 colon tumor over that observed with chemotherapy or NR-LU-10/PE alone.

ADP Ribose Transferases↗
PubMed1989

Inhibition of early murine hemopoietic progenitor cell proliferation after in vivo locoregional administration of transforming growth factor-beta 1.

Transforming growth factor-beta 1 (TGF beta 1) has been shown in vitro to be a potent negative regulator of growth and differentiation of early hemopoietic progenitor cells, but not of more mature progenitors. However, little information is yet available regarding similar effects in vivo. We have developed an approach whereby TGF beta 1 can be administered locoregionally to the bone marrow via direct injection into the femoral artery. Our studies show that intrafemoral administration of a single bolus dose of TGF beta 1 potently inhibits the baseline and IL-3-driven proliferation of bone marrow cells. This inhibition is relatively selective for the earlier multipotential granulocyte, erythroid, megakaryocyte, and macrophage CFU progenitor cells since these are completely inhibited while the more differentiated CFU assayed in culture colonies are inhibited by about 50%. The inhibition of hemopoietic progenitor growth and differentiation is both time and dose dependent with the maximal effect on the marrow observed at 24 h with doses greater than or equal to 5 micrograms/mouse, and the effect is reversed at later times. A possible practical implication of these in vivo results could be the use of TGF beta 1 to protect stem cells in the bone marrow from the myelotoxic effects of chemotherapeutic drugs.

Animals↗
PubMed1989

Chemoimmunotoxin therapy against a human colon tumor (HT-29) xenografted into nude mice.

The efficacy of intracavitary chemoimmunotoxin therapy for cancer treatment was evaluated using the human colon carcinoma (HT-29) which had been xenografted i.p. into nude mice. Mice bearing HT-29 were treated with an immunotoxin consisting of the monoclonal antibody OVB3 coupled to Pseudomonas exotoxin (OVB3-PE), with cyclophosphamide (Cy), or with both OVB3-PE plus Cy. Mice given injections i.p. of 3 x 10(6) HT-29 ascites cells developed a localized disease that presented as both malignant ascites and solid tumor confined to the peritoneal cavity. All mice died within 30 to 40 days. Mice that received either three or six injections of OVB3-PE at a dose of 0.5 micrograms every other day beginning 3 days post-tumor inoculation exhibited significantly increased median survival times (MSTs) (P = 0.002) of 62 and 68 days, respectively, as compared to a MST of 33 days for the controls. OVB3 alone or an irrelevant monoclonal antibody conjugated to PE exhibited no antitumor activity. The therapeutic effects of the immunotoxin could be blocked by giving a large amount of unconjugated OVB3 at the same time. Treatment of mice with Cy alone at the maximal tolerated dose (250 mg/kg) on Days 10 and 17 after tumor inoculation increased the MST from 33 days to 54 days. The maximum tolerated dose could be increased to 300 mg/kg per injection if the Cy treatment was preceded by 100 mg/kg of S-2-(3-aminopropylamino)ethyl phosphorothioic acid (WR-2721), a sulfhydryl compound that selectively protects normal tissue against the toxicity of radiation and alkylating agents. Cy plus WR-2721 treatment on Days 10 and 17 increased the MST from 35 to 61 days (P = 0.002). Interestingly, groups of mice that received either two, four, or seven treatments of OVB3-PE following Cy plus WR-2721 therapy exhibited a further increase (P less than 0.002) in MSTs to 81, 87, and 96 days, respectively. Thus, the combination of cytoreductive chemotherapy with the OVB3-PE was significantly more effective for the intracavitary treatment of established HT-29 colon cancer xenografts than either chemotherapy or immunotoxin therapy alone.

ADP Ribose Transferases↗
PubMed1989

Augmentation of mouse liver-associated natural killer activity by biologic response modifiers occurs largely via rapid recruitment of large granular lymphocytes from the bone marrow.

A variety of biologic response modifiers (BRM) can potently augment NK activity in nonlymphoid organs. By using the liver as a model organ, we have shown that this augmentation of organ-associated NK activity is coincident with a 10- to 15-fold increase in the number of large granular lymphocytes (LGL) which can be isolated. The present study was designed to investigate the mechanism by which BRM induce this increase in liver-associated LGL and the coincident increase in hepatic NK activity. Initial studies confirm that a single dose of the pyran copolymer, maleic anhydride divinyl ether (MVE-2), augmented hepatic NK activity and increased the number of liver-associated LGL from 3 x 10(4)/liver to 5 x 10(5)/liver (a 17-fold increase). Multiple injections of MVE-2 further augmented total liver-associated NK activity and LGL number (to 13 x 10(5)/liver). As expected, both the NK activity and detectable LGL were eliminated by treatment of the mice with antiasialo GM1 (asGM1) serum. Three possible mechanisms for the BRM-induced increase in liver-associated LGL have been investigated, including 1) the rapid proliferation of resident hepatic LGL, 2) the redistribution of mature LGL from peripheral sites such as the spleen, or by 3) a rapid output and subsequent hepatic localization of LGL or their precursors recently derived from the bone marrow (BM). Our results demonstrated that the contribution of in situ proliferation to the BRM-induced increase in liver-LGL was relatively small, since the number of cells expressing NK-associated markers (i.e., asGM1, Thy-1.2, and NK1.1) and in G2/M phase (as assessed by propidium iodide uptake) was only 4 to 8%. Further experiments demonstrated that splenectomy before the administration of MVE-2 did not inhibit the augmentation of liver-associated NK activity. This result argued against a recruitment of mature LGL from the spleen. In contrast, selective depletion of the BM following administration of 89Sr decreased the ability of MVE-2 to augment liver-associated NK activity by greater than 80%. This procedure also significantly decreased the ability of Propionibacterium acnes (85%) and multiple doses of IL-2 (49%) to augment liver-associated NK activity. These results demonstrate that the rapid augmentation of liver-associated NK activity by BRM is largely due to localization and accumulation in the liver of LGL recently derived from the BM.

Adjuvants, Immunologic↗
PubMed1989

Alteration of the B cell surface phenotype, immune response to phosphocholine and the B cell repertoire in M167 mu plus kappa transgenic mice.

M167, mu plus kappa, transgenic mice have been analyzed for the expression of the transgene product as a cell surface, Ag-specific receptor and for their ability to respond to Ag. The vast majority of B cells in these H + L transgenics (97 to 99%) express large amounts of the transgene product on their surface and are capable of binding phosphocholine. A total of 4 to 30% of the B cells also express endogenous IgM and IgD H chain products. After immunization with phosphocholine (PC)-conjugated keyhole limpet hemocyanin, more than 1000 micrograms/ml of anti-PC antibody bearing the transgene IgMa allotype marker are produced. Surprisingly, significant amounts of anti-PC antibodies that express the endogenous, IgMb allotype, are also produced; however, these antibodies lack the T15-idiotype which dominates the anti-PC response in their nontransgenic littermate controls. The B cells producing these endogenous anti-PC antibodies also fail to switch to IgG anti-PC synthesis, whereas B cells producing anti-keyhole limpet hemocyanin antibodies readily undergo class switching. These last two observations may be due to the fact that the endogenous anti-PC antibody actually results from mixed mu a + mu b molecules in which the transgene encoded H and L chains are most likely responsible for the binding of PC. Thus, a switch of the endogenous isotype from mu b to IgG would result in a loss of specificity for PC in the IgG molecules produced using the endogenous VH-gene product(s), and mu a + gamma b hybrid molecules are not likely to be formed. This hypothesis is supported by the fact that the majority of (mu a + mu b) hybridomas have the mu b-allotype joined with a VH region other than the VH1 gene which is required for PC-binding and T15 idiotype expression.

Animals↗
PubMed1989

Role of CD4 in thymocyte selection and maturation.

We examined the possible role of CD4 molecules during in vivo and in vitro fetal thymic development. Our results show that fetal thymi treated with intact anti-CD4 mAbs fail to generate CD4 single-positive T cells, while the generation of the other phenotypes remains unchanged. Most importantly, the use of F(ab')2 and Fab anti-CD4 mAb gave identical results, i.e., failure to generate CD4+/CD8- T cells, with no effect on the generation of CD4+/CD8+ T cells. Since F(ab')2 and Fab anti-CD4 fail to deplete CD4+/CD8- in adult mice, these results strongly argue that the absence of CD4+/CD8- T cells is not due to depletion, but rather, is caused by a lack of positive selection, attributable to an obstructed CD4-MHC class II interaction. Furthermore, we also observed an increase in TCR/CD3 expression after anti-CD4 (divalent or monovalent) mAb treatment. The TCR/CD3 upregulation occurs in the double-positive population, and may result from CD4 signaling after mAb engagement, or may be a consequence of the blocked CD4-class II interactions. One proposed model argues that the CD3 upregulation occurs in an effort to compensate for the reduction in avidity or signaling that is normally provided by the interaction of the CD4 accessory molecule and its ligand. As a whole, our findings advocate that CD4 molecules play a decisive role in the differentiation of thymocytes.

Animals↗
PubMed1989

Preferential differentiation of T cell receptor specificities based on the MHC glycoproteins encountered during development. Evidence for positive selection.

T cells recognize foreign antigens together with those MHC glycoproteins they have encountered during their development in the thymus. How the repertoire of antigen-specific TCRs is selected has not yet been fully defined. We have investigated the T cell repertoire specificities of CD4-CD8+ cytotoxic T cells developing under conditions where one of the class I MHC-encoded molecules is blocked, while other class I-MHC glycoproteins are still expressed. We show that antigen-specific T cells restricted to the blocked class I fail to develop, while generation of other class I-specific T cell proceeds undisturbed. This highly selective perturbation of the T cell receptor repertoire demonstrates that development of CD4-CD8+ T cells with a certain TCR specificity requires expression of particular alleles of class I MHC. Thus, TCR-MHC interactions provide signals essential to the differentiation of precursor T cells.

Animals↗
PubMed1989

Randomized trial of recombinant alpha 2b-interferon with or without indomethacin in patients with metastatic malignant melanoma.

alpha-Interferon has antitumor activity in a variety of malignancies but is frequently associated with unacceptable toxic side-effects. The routine use of agents potentially capable of reducing these side-effects has not been recommended out of concern for possible reductions in the therapeutic activity of interferon. We conducted a prospective randomized trial of alpha-interferon given with or without indomethacin to patients with malignant melanoma to determine what effect, if any, indomethacin might have on the toxic, immunomodulatory, and therapeutic properties of interferon in this disease. 53 patients were stratified according to performance status and randomized to receive alpha 2b-interferon, 20 million units per m2 i.v., 5 days per week for 4 weeks followed by 10 million units per m2 s.c. three times per week, either with or without indomethacin, 25 mg orally three times a day. The overall major response rate was 13% (three complete responders and three partial responders among 47 evaluable patients) and was the same on both arms. The mean maximal temperature elevation induced by interferon was significantly reduced (from 102.1 to 100.7, P = 0.0002) by indomethacin, but the incidence and severity of interferon-related fatigue, reduction in performance status, headache, depression, confusion, elevations in liver function tests, and myelosuppression were no different in either arm of the study. Indomethacin did not reduce the frequency of dose reductions for toxic side-effects and did not permit the administration of higher interferon doses. Peripheral blood natural killer activity was significantly enhanced in patients during maintenance therapy whether or not they received indomethacin. Indomethacin appeared to inhibit augmentation of natural killer activity during high dose induction therapy. Immunological changes did not correlate with response status. We conclude that indomethacin can reduce the fever associated with interferon therapy in patients with malignant melanoma without interfering with its therapeutic or chronic immunomodulatory activities. Since fever is rarely the dose-limiting toxicity of interferon, indomethacin is of marginal benefit to patients with malignant melanoma receiving interferon at the doses outlined in this study.

Adult↗
PubMed1989

Positive selection of CD4-CD8+ T cells in the thymus of normal mice.

The diversification of the repertoire of T-cell antigen receptor (TCR) specificities is influenced by at least two selection processes which occur in the thymus. One of these, termed 'negative selection', is required to install a state of tolerance to self-antigens in the T-cell repertoire and is often achieved by clonal deletion. The second type of selection operating in the thymus results in preferential differentiation of T cells that have restriction specificity for thymic major histocompatibility complex glycoproteins, but the mechanisms leading to this selective process are not yet clear. One model used to describe this 'positive selection' proposes that only those T cells with sufficient avidity for the MHC glycoproteins expressed in the thymus are allowed to acquire functional competence. Here we directly investigate the generation of TCR specificities by following the fate of developing V beta 17+ CD4-CD8+ T cells under conditions where one of the main class I-MHC molecules, either H-2K or H-2D, was specifically blocked by in vitro monoclonal antibody treatment. The results show that development of V beta 17+ CD4-CD8+ T cells in the SJL H-2s mouse strain is selectively abrogated by blocking class I-Ks molecules but is unaffected by blocking class I-Ds molecules. These data directly demonstrate that generation of CD4-CD8+ T cells expressing a particular TCR V beta segment can be correlated with the expression of a particular class I-MHC molecule, thereby providing evidence for positive selection.

Animals↗