Cell adhesion molecules mediate radiation-induced leukocyte adhesion to the vascular endothelium

The predominant early histological changes in irradiated tissues are edema and leukocyte infiltration. Cell adhesion molecules (CAMs) are required for the extravasation of leukocytes from the circulation. To study the role of CAMs in the pathogenesis of radiation-mediated inflammation, we quantified the expression of P-selectin, E-selectin, intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 glycoproteins on the surface of irradiated human endothelial cells. We found that E-selectin and ICAM-1 expression increased after irradiation, whereas there was no increased expression of other cytokine-inducible adhesion molecules (P-selectin or vascular cell adhesion molecule-1). We found a dose- and time-dependent increase in radiation-induced expression of both E-selectin and ICAM-1. Furthermore, the threshold dose for E-selectin expression was 1 Gy, whereas the threshold dose for ICAM-1 synthesis was 5 Gy of X-rays. Northern blot analysis of RNA from irradiated endothelial cells demonstrated that ICAM-1 is expressed at 3-6 h following irradiation. No de novo protein synthesis was required for increased ICAM-1 mRNA expression. The 1.1-kb segment of the 5' untranslated region of the ICAM-1 gene was sufficient for X-ray induction of chloramphenicol acetyltransferase reporter gene expression. We measured whether ICAM-1 mediates adhesion of leukocyte to the irradiated endothelium and found that leukocyte adhesion occurred concurrently with ICAM-1 induction. Radiation-mediated leukocyte adhesion was prevented by anti-ICAM-1 blocking antibodies. These data indicate that ICAM-1 participates in the inflammatory response to ionizing radiation. Moreover, radiation induction of these CAMs occurs in the absence of tumor necrosis factor and interleukin 1 production.

Eye shielding for patients treated with total body irradiation

The incidence of cataracts in patients who have received total body irradiation (TBI) is about 20% and increases to 40% if the patient is treated for graft-versus-host disease. At our institution, all TBI patients are treated with two lateral opposed 24 MV photon fields. No attempt is usually made to shield the eyes during the TBI treatment because of the amount of lead required to adequately attenuate megavoltage photon beams, the difficulty in properly positioning an eye shield and the possibility of compromising the effectiveness of the treatment. However, we were asked to treat a TBI patient who is a professional pilot, and thus his livelihood is contingent upon maintaining perfect vision. A custom eye shield was constructed out of lead and ionization chamber and film measurements were performed under TBI conditions to determine the thickness and location of the eye block to optimize the competing effects of increased scatter and attenuation from the lead. Phantom data were also obtained for 6 MV irradiation for comparison with 24 MV. In-vivo patient and phantom measurements with thermoluminescent dosimeters showed that with visual positioning of the eye block the dose was reduced from 16 to 20% across the orbits of both eyes.

E-selectin gene induction by ionizing radiation is independent of cytokine induction

The mechanism of the x-ray-mediated inflammatory response in normal tissues is unknown. To determine whether leukocyte infiltration into irradiated tissue is regulated by adhesion molecule expression, we quantified the synthesis of glycoproteins that participate in inflammation. We found that E-selectin is synthesized in a time-dependent manner following exposure to doses as low as 0.5 Gy. Northern blot analysis demonstrated that E-selectin mRNA expression increased at 2 h after x-irradiation and increased expression required no de novo protein synthesis. Transcription of the promoter region of E-selectin (-578 to +35) was transiently induced following x-irradiation, whereas deletion of the NFkB binding site eliminated x-ray induction. Electrophoretic mobility gel shift analysis confirmed increased binding of nuclear proteins from irradiated endothelial cells to the NFkB binding sequence from the E-selectin promoter. Nuclear protein binding to the NFkB binding sequence was altered by antibodies to the p50 and p65 components of NFkB. These data demonstrate that E-selectin expression does not require cytokine synthesis, but involves NFkB activation.

Patterns of failure following high-dose chemotherapy and autologous bone marrow transplantation with involved field radiotherapy for relapsed/refractory Hodgkin's disease

PURPOSE

To evaluate the patterns of failure and outcome of patients undergoing high-dose chemotherapy and autologous bone marrow transplantation for relapsed/refractory Hodgkin's disease with emphasis on the impact of involved-field radiotherapy.

METHOD AND MATERIALS

Fifty-four adult patients with refractory (25) or relapsed (29) Hodgkin's disease underwent high-dose chemotherapy with either autologous bone marrow (32) or peripheral stem cell (23) transplantation. Twenty patients received involved-field radiotherapy either prior to (7) or following (13) high-dose chemotherapy. Patients treated prior to the high-dose chemotherapy received radiation to bulky or symptomatic sites, and those treated following the transplantation were treated to sites of disease persistence (10) or to consolidate a complete response (3). Twenty-six patients had purely nodal disease, 10 had lung involvement, 7 liver, 5 bone, and 3 bone marrow. A total of 147 sites were present prior to high-dose chemotherapy. Nineteen were bulky (> or = 5 cm), and 42 arose in a previous radiotherapy field.

RESULTS

Twenty-five of the 54 patients (46.3%) relapsed. Seventeen (68.0%) relapsed in sites of disease present prior to high-dose chemotherapy. Patients treated with involved-field radiotherapy had a lower rate of relapse in sites of prior disease involvement (26.3 vs. 42.8%) (p < 0.05) than those not treated with radiotherapy. Twenty-one patients had disease persistence following high-dose chemotherapy, of which 10 received involved-field radiotherapy and were converted to a complete response. Patients with disease persistence who received involved-field radiotherapy had a better progression-free survival (40.0 vs. 12.1%) (p = 0.04) than those who did not. Moreover, the patients converted to a complete response had similar progression-free and cause-specific survival as those patients achieving a complete response with high-dose chemotherapy alone. Of the initial 147 sites, 142 (97.3%) were amenable to involved-field radiation therapy. The addition of involved-field radiotherapy improved the 5-year local control of all sites (p = 0.008), nodal sites (p = 0.01), and sites of disease persistence (p = 0.0009).

CONCLUSIONS

Patients with relapsed/refractory Hodgkin's disease undergoing high-dose chemotherapy and autologous bone marrow rescue have a high rate of relapse in sites of prior disease involvement. Involved-field radiotherapy is capable of improving the control of these sites, the majority of which are amenable to radiotherapy. In addition, the use of radiotherapy to sites of disease persistence following high-dose chemotherapy may improve the outcome of these patients.

A randomized, double-blind, placebo-controlled trial of systemically administered interferon-alpha, -beta, or -gamma in combination with cryotherapy for the treatment of condyloma acuminatum

One hundred fifty-two patients were enrolled in a study to evaluate 3 interferon (IFN) preparations used in combination with cryotherapy for treatment of anogenital warts. Subjects received subcutaneous injections (2 x 10(6) units/m2) of IFN-alpha n1, -beta, -gamma or placebo 3 times a week for 6 weeks and cryotherapy with liquid nitrogen. Subjects were followed < or = 1 year. Among patients followed > or = 12 weeks, two-thirds had a complete response. No significant differences in rates of complete response (P = .37) or reappearance of a wart at the initial site (P = .20) were noted among the treatment groups. However, patients who received IFN-beta or -gamma developed new warts at a significantly lower frequency (P = .02). IFN administration was associated with side effects but was well tolerated. IFN-beta was the least toxic of the 3 preparations and had the best therapeutic ratio.

Radiation induction of immediate early genes: effectors of the radiation-stress response

Recent studies have demonstrated that the early response genes c-jun, Egr-1, c-fos, and NF kappa B are induced following exposure of mammalian cells to ionizing radiation. We propose that the products of these early response genes regulate downstream genes that are important in the adaptation of cells and tissues to radiation-induced stress. Potential downstream targets include cytokine and growth factor genes as well as deoxyribonucleic acid (DNA) repair genes. Early response gene products may also regulate cell cycle progression following cellular x-irradiation. Signal transduction pathways that allow cells to adapt to radiation may provide molecular targets to modify tumor and normal responses to radiotherapy.

Efficacy and safety of 0.5% podofilox solution in the treatment and suppression of anogenital warts

PURPOSE

For the patient-administered treatment of anogenital warts, 0.5% podofilox (podophyllotoxin), one of the active compounds of podophyllin, has been shown to be more effective than the vehicle alone. This study was designed to evaluate the safety and efficacy of 0.5% podofilox treatment followed by prophylaxis.

PATIENTS AND METHODS

A total of 103 patients were entered in stage 1 of the study. Stage 1 was an open label study, and patients self-administered 0.5% podofilox twice daily for 3 consecutive days per week for 4 weeks. A total of 100 patients remained available for efficacy and safety analyses. At the end of stage 1, patients who had a complete response proceeded to stage 2 of the study. Patients who had a 50% to 99% reduction in measured total wart area were offered cryotherapy every 10 days, up to 5 times. If cleared of warts, they were also entered into stage 2. A total of 57 patients were enrolled into stage 2, a double-blind, randomized, placebo-controlled prophylactic study of 0.5% podofilox self-administered once daily for 3 days per week for 8 weeks, on the sites of healed warts. A total of 45 patients in stage 2 were available for efficacy analysis.

RESULTS

By the end of stage 1, 68% of the warts had disappeared, and 29 of 100 patients (29%) had a complete response. A total of 49 patients had a 50% or greater improvement in wart area and underwent cryotherapy. Rates of local side effects after 1 week of treatment were 57% for inflammation, 39% for erosion, 47% for pain, 48% for burning, and 44% for itching. However, these symptoms and signs were mostly mild to moderate in intensity and diminished over time. Therefore, overall treatment was well tolerated. In stage 2, only 4 of 21 patients (19%) in the podofilox group experienced a recurrence as opposed to 12 of 24 (50%) in the placebo group (P = 0.031). As in stage 1, the side effects were modest, and the drug was well tolerated.

CONCLUSION

This study confirms the efficacy and good tolerance of 0.5% podofilox in the treatment of anogenital warts. It also establishes the safety and superior efficacy of patient-administered podofilox over the vehicle alone as prophylaxis against recurrence of lesions. Although long-term efficacy and tolerance remain to be established, podofilox appears to be a useful agent in the control of this disease.

Ionizing radiation activates transcription of the EGR1 gene via CArG elements

The present studies have examined the effects of ionizing radiation on control of the early growth response 1 (EGR1) gene. Exposure of human HL-525 cells to x-rays was associated with increases in EGR1 mRNA levels. Nuclear run-on assays showed that this effect is related at least in part to activation of EGR1 gene transcription. Sequences responsive to ionizing radiation-induced signals were determined by deletion analysis of the EGR1 promoter. The results demonstrate that x-ray inducibility of the EGR1 gene is conferred by a region containing six serum response or CC(A+T-rich)6GG (CArG) motifs. Further analysis confirmed that the region encompassing the three distal or upstream CArG elements is functional in the x-ray response. Moreover, this region conferred x-ray inducibility to a minimal thymidine kinase gene promoter. Taken together, these results indicate that ionizing radiation induces EGR1 transcription through CArG elements.

3-D treatment planning and dose delivery verification integrating a variety of state-of-the-art techniques: a case report

A patient previously treated with radiation for base-of-tongue cancer presented with recurrent disease seven years later. The spinal cord had received tolerance dose. Using state-of-the-art treatment planning techniques, including beam's-eye-view and volumetrics, dose-volume histograms, split field technique, mixed energies, and beam intensity modulation (with a compensator), we achieved uniform dose coverage of the target in 3-D. This was verified in vivo with thermoluminescence dosimeters positioned in the esophagus by means of a nasogastric tube that ran centrally through the target volume. The various techniques applied will be presented with a discussion of the rationale used in each step of plan optimization and verification.

Mycosis fungoides involving the central nervous system

The clinical records of nine patients, followed at the University of Chicago, with mycosis fungoides (MF) and neurologic deficits due to direct CNS involvement were reviewed. Lymph node and visceral involvement was present in all patients. Clinical findings included cranial nerve deficits in four patients, altered mental status in eight, gait disturbances in three, and leg weakness in one. Helpful diagnostic studies included lumbar puncture with CSF cytology, computerized tomography (CT) brain scans, brain biopsy, and myelogram. Two patients, who were treated with radiation therapy (RT), survived 14 and 40 weeks, respectively. Survival of less than 4 weeks limited treatment in the other patients. Autopsies were performed on six patients and revealed meningeal infiltration and perivascular infiltration of the brain. In addition, the cerebral parenchyma was infiltrated in one patient and a lymphomatous tumor was found in the brainstem of another. We conclude that the varied clinical and pathologic features of CNS involvement with mycosis fungoides resemble those seen in leukemias and other lymphoproliferative disorders. Better awareness of the clinical features may permit earlier diagnosis and initiation of therapy.