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Biomedical subjects

R B Pollard

Publications and source records attributed to R B Pollard.

At least 109 records · Page 6Linked to original sources
PubMed1987

Suppressor cells generated in mice late after thermal injury.

A second suppressive state (S-SupS) in interferon (IFN) response was demonstrated when mice with third-degree burns of approximately 30% of the body surface area (TI-mice) were stimulated in vivo by Staphylococcal enterotoxin A, a gamma IFN inducer. The first suppressive state in IFN production, appearing 3 to 7 days after thermal injury, was mediated by the generation of splenic suppressor macrophages. The S-SupS was demonstrated approximately 3 weeks post thermal injury. It persisted for almost 3 weeks and gradually disappeared by 7 weeks. Spleen cells from mice during the S-SupS produced less IFN in vitro than normal mouse splenic mononuclear cells (MNC) when stimulated with concanavalin A (Con A). Splenic MNC of mice during the S-SupS inhibited IFN production when they were co-cultured with normal mouse splenic MNC in the presence of Con A. Since this suppressor cell activity could not be removed from TI-mice splenic MNC by carbonyl iron treatment, or by a technique of adherence to a plastic surface, it is suggested that two different cell populations which are capable of suppressing the IFN response of TI-mice exist at different time periods following burn injury.

Animals↗
PubMed1987

The use of interferon in the treatment of multiple myeloma.

Almost all patients with multiple myeloma still relapse or become refractory in 2 to 3 years. Interferon (IFN) therapy has clearly influenced the levels of abnormal serum proteins in some patients. A multi-institutional phase II clinical trial used alfa-2b recombinant interferon (Intron A, Schering, Kenilworth, NJ) in 38 evaluable patients with relapsing and refractory multiple myeloma; two thirds of the patient population had received extensive prior treatment. Seven responded, of whom three continued to do so beyond 1 year--one with an ongoing complete remission. An additional 13 had at least a 25% decrease in abnormal paraproteins. Of nine patients who were initially refractory to chemotherapy, two responded to IFN. Of nine relapsing patients returned to chemotherapy following IFN therapy, six then responded. Thirty previously untreated patients with multiple myeloma were treated with IFN followed by melphalan and prednisone; of 24 evaluable patients, 18 responded with a median duration of 10+ months. Alfa-2b IFN apparently does not antagonize melphalan or prednisone, nor does it appear to worsen the response of the two drugs alone. Effectiveness of recombinant alfa-2b IFN in pretreated relapsing patients suggests additional trials are needed to study its effects in previously untreated patients. A significant number of patients who relapsed on their original chemotherapy and subsequent interferon will apparently respond to the reinstitution of chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1986

Suppression of interferon gamma production in mice treated with carrageenan.

Effects of carrageenan (CAR) treatment on the response of interferon (IFN) production in vivo and in vitro after stimulation with an IFN-gamma inducer, staphylococcal enterotoxin A (SEA), was investigated. The IFN-gamma production in mice stimulated with SEA was impaired after i.v. administration of a 20 mg/kg dose of CAR. Spleen cells (SC) from CAR-treated mice had decreased ability to produce IFN in vitro after stimulation with the same inducer. SC obtained from mice during the suppressive state inhibited IFN-gamma production when they were co-cultured with mononuclear cells prepared from spleens of untreated control mice. This suppressor cell activity could be removed from SC by an adherence technique to plastic surface. The SC with suppressor activity were not inactivated by treatments with monoclonal anti-Thy-1.2 antibody, anti-asialo GM1 antisera and anti-mouse immunoglobulin antisera followed by complement. The suppressive activity was detected in cell-free culture fluids of macrophage fractions containing suppressor cell activity. These results suggest that the decrease in IFN-gamma production in mice pretreated with CAR may associate with the presence of suppressor cells characterized to the monocyte/macrophage lineage.

Animals↗
PubMed1986

Cortisol stimulation by recombinant interferon-alpha 2.

Serum cortisol concentrations were determined by radioimmunoassay in cancer patients undergoing experimental therapy with recombinant interferon-alpha 2. Cortisol concentration rose steadily after interferon administration and was significantly different from that on control day at 8 h following intramuscular injection of interferon-alpha 2. Cortisol elevation was increased as weekly doses of interferon were increased (0-120 X 10(6) units). Recent clinical trials of interferons for treatment of neurological and malignant diseases provide a compelling need to understand the actions and side effects of exogenously administered interferons.

Adult↗
PubMed1986

Importance of Lyt 1+ T-cells in the antitumor activity of an immunomodulator, SSM, extracted from human-type Tubercle bacilli.

An arabinomannan lipid extracted from Mycobacterium tuberculosis strain Aoyama B (SSM) is an immunopotentiating agent with interferon-inducing and antitumor activities. In the present study, the possible role(s) of various immunocompetent cells on the antitumor effect of SSM was investigated in mice bearing syngeneic (RL male 1 leukemia) and allogeneic (Ehrlich carcinoma) ascites tumors. When Thy 1+ T-cells were depleted from tumor-bearing mice by the administration of monoclonal anti-Thy 1.2 antibody, the protective effect of SSM was eliminated. However, when macrophage (M phi) and natural killer (NK) cell activities were depleted by treatment with M phi blockers (trypan blue and carrageenan) or a blocker for NK cells (anti-asialo GM1 antiserum), no alteration of the antitumor activity of SSM was observed. Therefore, T-lymphocytes, but not M phi or NK cells, were required for the expression of the antitumor efficacy of SSM. The antitumor activity of SSM was also abrogated by Lyt 1+ T-cells being depleted by treatment with monoclonal anti-Lyt 1.2 antibody, whereas the administration of monoclonal anti-Lyt 2.2 antibody had no effect on the antitumor activity. Independent of M phi, NK cells, or Lyt 2+ T-cells, Lyt 1+ T-lymphocytes appear to play an important role in the expression of the antitumor effects of SSM.

Adjuvants, Immunologic↗
PubMed1985

Ability of sera from mice treated with Ge-132, an organic germanium compound, to inhibit experimental murine ascites tumours.

Sera from C57Bl/6 mice treated orally with Ge-132 exhibited antitumour activity against Ehrlich (allogeneic) and RL male 1 (syngeneic) ascites tumours in BALB/c mice. Sera obtained from mice 24 h after Ge-132 administration displayed the greatest antitumour effect and this was dose dependent. Sera prepared from mice 12, 36, or 48 h after Ge-132 treatment had no protective effect. Circulating interferon (IFN) was induced at 24 h after administration of Ge-132 but was not detected in the sera at 12, 36, or 48 h after administration. The antiviral activity of sera from Ge-132-treated mice was inactivated by treatments with trypsin, low pH, and anti-IFN gamma antiserum. The inactivated preparations of serum IFN induced by Ge-132 did not exhibit antitumour activity when administered to tumour-bearing mice. These results suggest that antitumour activity in the sera of Ge-132-treated mice may be expressed through activities of Ge-132-induced lymphokine(s), such as IFN gamma.

Animals↗
PubMed1985

Phase II study of recombinant alpha-2 interferon in resistant multiple myeloma.

A multicenter phase II study of INTRON, recombinant alpha-2 interferon (Schering Corp, Kenilworth, NJ), in patients with relapsing or refractory myeloma was initiated. Patients received either intravenous therapy for two weeks followed by subcutaneous therapy or subcutaneous dosing from initiation of treatment. Of 38 evaluable patients, 19 were refractory and 19 had relapsed at entry. Twenty-five of 38 had received prior treatment with multiple drugs. Responses were seen among 2/19 refractory patients and 5/19 relapsing patients. Three of seven responders continue to respond for more than one year while receiving maintenance therapy. Most patients experienced improvement in bone pain, and one patient, with a complete response, had healing of bone lesions. Survival curves show a statistically significant improvement in survival for responders v nonresponders. INTRON was well-tolerated with only four patients discontinuing treatment due to adverse effects. Thirty-two percent of patients had hematologic toxicity requiring dose adjustment; however, there was no evidence of cumulative hematologic toxicity. No patients developed serum neutralizing factors to interferon. Additional trials are warranted to study the activity of INTRON in previously untreated patients.

Adult↗
PubMed1984

Prevention of suppressed interferon gamma production in thermally injured mice by administration of a novel organogermanium compound, Ge-132.

As reported previously, gamma interferon (IFN-gamma) production was selectively decreased in thermally injured mice (TI-Mice) and spleen cell cultures from the mice following stimulation with various IFN inducers. The decrease in IFN production was associated with splenic suppressor macrophages. The present study demonstrated that TI-Mice treated with Ge-132 (TGe-Mice) produced IFN following stimulation with IFN-gamma inducers. The level of IFN activity detected in the sera of TGe-Mice approximated that of controls. Similar results were obtained when spleen cells prepared from TGe-Mice were stimulated with IFN-gamma inducers in vitro. While transfer of spleen cells from TI-Mice resulted in the suppression of IFN production in normal mice (N-Mice) stimulated with IFN-gamma inducers, the transfer of spleen cells derived from TGe-Mice did not induce suppression of IFN production in N-Mice. Mononuclear cells (MNC) prepared from N-Mice produced IFN following concanavalin A (Con A) stimulation when they were co-cultured with macrophage-enriched populations (PAC) obtained from the spleens of TGe-Mice. In contrast, MNC stimulated with Con A did not produce IFN activity when they were co-cultured with PAC of TI-Mice. These results suggest that the generation of suppressor macrophages in TI-Mice may be altered by the administration of Ge-132.

Animals↗
PubMed1982

Specific cell-mediated immunity and infections with herpes viruses in cardiac transplant recipients.

Immune responses and infections with herpes viruses were studied prospectively in 36 cardiac transplant recipients. Specific lymphocyte transformation and interferon production in response to viral antigens, viral culture results, antibody levels, responses to phytohemagglutinin, and T-cell numbers were determined. Responses to phytohemagglutinin and T-cell numbers were depressed for six to 12 weeks. Cytomegalovirus infection occurred in 100 percent of seropositive patients and in 62 percent of seronegative patients. Primary infection was more frequently symptomatic. Heart implantation from a seropositive patient wwas significantly correlated with subsequent infection in seronegative patients. Depression of transformation in response to cytomegalovirus correlated with prolonged shedding. Herpes simplex infection occurred in 95 percent of seropositive patients but decreased after 12 weeks. Asymptomatic shedding was rare, and primary infection did not occur. Return of transformation in response to herpes simplex was associated with decreased infection. Herpes zoster occurred in 22 percent during the first year, and transformation responses to varicella-zoster returned thereafter. Depression of interferon production in response to viruses did not correlate with infection as well as did lymphocyte transformation.

Antibodies, Viral↗
PubMed1982

Presence of interferon during bacterial otitis media.

To examine the possibility that interferon (IFN) production plays a role in otitis media, specimens of middle ear fluid (MEF) were cultured for bacteria and viruses and assayed for IFN. Twenty (33%) of 81 MEF specimens from children attending a pediatric clinic contained 50-600 units of IFN/ml. Characterization of high-titered samples by cell species specificity, stability at pH 2, nonspecificity for virus, and cell-bound antiviral activity showed the major properties of IFN. With or without the addition of antibody to IFN to 88 specimens of MEF before viral culture, viruses were recovered from only four specimens (5%) whereas bacteria were isolated from 62 specimens (70%). IFN was present in most MEF specimens from which bacteria were isolated. Among the MEF specimens that contained bacteria and IFN, there was no association with a particular bacterial species.

Adenoviruses, Human↗
PubMed1982

Antiviral treatment of chronic hepatitis B virus infection: pharmacokinetics and side effects of interferon and adenine arabinoside alone and in combination.

In an uncontrolled trial, 29 patients with chronic hepatitis B virus infection were treated with 93 courses of adenine arabinoside at doses ranging from 2.5 to 15 mg/kg per day. Most patients were treated concomitantly with human leukocyte interferon. Significant, but transient, neurotoxicity was seen with adenine arabinoside therapy in 44% of all courses. Manifestations of toxicity were mainly neurological and ranged from pain syndromes to tremors and, rarely, seizures. Suppression of numbers of lymphocytes was also noted. All effects were reversible with time. The extent of toxicity was dependent upon the dosage of adenine arabinoside. Treatment with interferon appeared to potentiate the occurrence of toxicity with adenine arabinoside. Arabinofuranosylhypoxanthine serum levels increased in a dose-dependent manner and tended to accumulate in interferon-treated hepatitis patients during a course of therapy. Elevated blood levels and drug accumulation were associated with toxicity in a significant fashion. Human leukocyte interferon was administered to 38 patients in 113 separate courses. Interferon side effects were rapidly reversible upon cessation of therapy. These included initial fever, myalgias, and hair loss as well as suppression of granulocytes, platelets, and lymphocytes in the blood.

Drug Therapy, Combination↗
PubMed1982

Cytomegalovirus immune plasma in bone marrow transplant recipients.

The effects of passive immunization on cytomegalovirus infection and interstitial pneumonia in marrow transplants were evaluated in a randomized, controlled trial. Twenty-four patients received cytomegalovirus immune plasma before and after transplantation, and 24 patients were controls. Although the incidence of cytomegalovirus infection was similar in the control and plasma groups, symptomatic infection (12 of 24 versus five of 24, p = 0.07) and interstitial pneumonia (11 of 24 versus five of 24, p = 0.12) occurred less frequently in the group receiving plasma. Cytomegalovirus infection occurred in 11 of 13 recipients of leukocyte transfusions and in 16 of 35 patients not given leukocyte transfusions (p = 0.02). Among patients not given leukocyte transfusions, the incidence of cytomegalovirus infection was similar in the control and plasma groups, but symptomatic infection (eight of 18 versus one of 17, p = 0.03) and interstitial pneumonia (nine of 18 versus one of 17, p = 0.01) were significantly less in the group receiving plasma. These results suggest that passive immunization modifies cytomegalovirus infection in humans and prevents interstitial pneumonia in marrow transplants especially when leukocyte transfusions are not used.

Adolescent↗
PubMed1982

Alterations of interferon production in a mouse model of thermal injury.

The effect of thermal injury on the response of interferon (IFN) production in vivo and in vitro after stimulation with eight representative inducers was investigated in a mouse model. The response of mice to immune IFN (IFN-gamma) inducers, staphylococcal enterotoxin A, concanavalin A, and a specific antigen for BCG-sensitized lymphocytes (purified protein derivative) was impaired after a 30% total body surface area third-degree burn. Suppression of IFN-gamma production was observed at day 2 and persisted until day 7 after burn. Decreased IFN-gamma production correlated closely with the percentage of total body surface area burned. When virus type IFN (IFN-alpha/beta) inducers, Newcastle disease virus, polyriboinosinic-polyribocytidylic acid, 10-carboxymethyl-9-acridanone, and E. coli endotoxin, were administered to mice, no change in IFN response was observed after thermal injury. Similar results were obtained when spleen cells obtained from thermally injured mice were stimulated with IFN-gamma inducers in vitro. These studies suggest that although the capacity for IFN-alpha/beta production remains intact in thermally injured mice, IFN-gamma production may be selectively decreased in burned animals and in their spleen cells.

Animals↗
PubMed1982

Mechanism for the suppression of gamma-interferon responsiveness in mice after thermal injury.

As reported previously, gamma-interferon production was decreased after the administration of inducers to thermally injured mice as compared with noninjured controls. Similarly, spleen cells from injured mice had decreased ability to produce interferon in vitro after stimulation with inducers. The present study demonstrated that the decrease in interferon production was associated with the presence of suppressor cells in the spleen of burned mice that were capable of inhibiting interferon production by normal splenic lymphocytes in vitro. Passive transfer of spleen cells containing suppressor cell activity derived from injured mice induced suppression in normal mice, and the time of the appearance of suppressor cell activity in injured mouse spleens closely approximated the time of the appearance of the suppression of interferon production observed in mice after thermal injury. The suppressor cells were characterized as a population of macrophages by the following: they adhered to plastic surface and could be removed from spleen cells by carbonyl-iron treatment; treatment of plastic-adherent cells with anti-Thy-1.2 and anti-mouse immunoglobulin antisera followed by complement failed to abrogate the suppression produced by these cells.

Animals↗
PubMed1981

Antiviral treatment of chronic hepatitis B virus infection. I. Changes in viral markers with interferon combined with adenine arabinoside.

Twenty patients with chronic active hepatitis and 12 patients with chronic persistent hepatitis associated with hepatitis B virus (HBV) infection were treated with human leukocyte interferon or adenine arabinoside alone or in combination. With interferon alone, four of 16 patients showed a permanent disappearance of HBV-associated DNA polymerase (DNAP) activity from serum. Of six patients treated with adenine arabinoside alone, only one patient became permanently DNAP-negative. With a regimen of multiple cycles of combined interferon and adenine arabinoside, seven of 16 male patients became permanently DNAP-negative. Of 69 patients who met the criteria for admission to the program, spontaneous decreases in DNAP activity without treatment were observed in only 9% during a mean observation period of 10 months. In general, patients with chronic active hepatitis, those who are female, and those with a history of recent steroid therapy responded to the antiviral agents significantly better than did the other patients.

Adult↗