Indium-111-oxine labeled leukocyte uptake in Ki-1-positive anaplastic large cell lymphoma.

Indium-111-oxine labeled leukocyte ((111)In-WBC) scintigraphy is well known for its ability to localize in areas of active infection, but not in areas of lymphomatous involvement. We present a case of Ki-1-positive anaplastic large-cell lymphoma that was initially thought to be a case of multifocal osteomyelitis because of positive uptake on a (111)In-WBC scan. The areas of abnormal uptake on the indium scan were demonstrated histopathologically to be sites of lymphomatous involvement in bone.

A multi-institutional retrospective study of intracranial ependymoma in children: identification of risk factors.

PURPOSE: The goal of this multi-institutional retrospective study of children with intracranial ependymoma was to identify risk factors associated with unfavorable overall survival (OS) and event-free survival (EFS). PATIENTS AND METHODS: Clinical data, including demographics, tumor location, spread, histology, details of surgery, radiation treatment, and chemotherapy were collected. Clinical characteristics and univariate and multivariate analyses of risk factors for OS and EFS are presented. RESULTS: Eleven U.S. institutions contributed 83 patients treated from 1987 to 1991. The OS at 5 and 7 years was 57% and 46%, and EFS at 5 and 7 years was 42% and 33%. Patients 3 years of age or younger differed from the older group by more common infratentorial location, less common gross total resection (GTR), and postoperative use of chemotherapy rather than radiation. This younger group of patients had worse survival (P < 0.01) than the older age group. Other than young age, less than GTR and World Health Organization (WHO) II grade 3 histology were significant adverse risk factors for EFS in univariate and multivariate analyses. OS shared the same adverse risk factors except for histology in multivariate analysis, which was only of borderline significance (P = 0.05). Progression at the original tumor location, present in 89% of patients, was the major pattern of tumor recurrence. Adjuvant chemotherapy in the group older than 3 years or craniospinal radiation in M0 patients did not significantly change EFS. CONCLUSIONS: Adverse outcome in childhood intracranial ependymoma is related to age (3 years or younger), histology (grade 3), and degree of surgical resection (less than GTR). New approaches, particularly for local tumor control in younger patients, are needed to improve survival.

Cytokine-enhanced NK cell-mediated cytotoxicity. Positive modulatory effects of IL-2 and IL-12 on stimulus-dependent granule exocytosis.

NK cells are a subpopulation of lymphocytes that kill virally infected cells and tumor cells without previous sensitization. Although exposure to distinct cytokines, including IL-2 and IL-12, can enhance these cytotoxic responses, the mechanism of this lymphokine-augmented killing remains unclear. Inasmuch as the cytotoxic event is a multistep process, there are many potential targets for lymphokine regulation. We focused on whether selected lymphokines directly modulate the intracellular signaling pathways critical for NK cell secretory function. In our experimental model, homogeneous, cloned human CD16+/CD3- NK cells were pretreated with either IL-2 or IL-12 and then stimulated with direct pharmacologic activators of the secretory response (e.g., PMA and ionomycin for intact cells or GTP gamma S for streptolysin-O permeabilized cells). Previous exposure of the cells to IL-2 or IL-12 enhanced the stimulus-induced release of granule-derived proteins (hexosaminidase and serine proteases) in a cytokine concentration- and time-dependent fashion. Furthermore, the cytokines increased the efficacies without changing the potencies of the secretagogues used in these studies. These results suggest that IL-2 and IL-12 augment NK cell-mediated cytotoxicity by increasing the maximal level of granule exocytosis evoked by Ca2+ and/or G protein-dependent intracellular signaling pathways.