[NOVEL APPROACH TO COMPOSITION OF, BACTERIOPHAGE MIXTURES FOR ANTIBACTERIAL THERAPY].

AIM: Evaluate antibacterial activity of an experimental mixture of phages, belonging to several well-studied species. MATERIALS AND METHODS: The study was carried out using a group of 55 clinical Pseudomonas aeruginosa strains of various origins,- 4 mono-species mixtures of 32 virulent bacteriophages (species phiKZ-, phiKMV-, phiPBl-, PaP3-like phages) and 2 novel phages, phiMK (species PaK-P2) and phiPerm5. Activity of preparations from mono-species mixtures of bacteriophages ofvarious species were compared with activity of 3 commercial mixtures. Standard methods of study of bacteriophages were used: determination of lytic activity by seeding onto bacterial lawns of P. aeruginosa, restriction analysis of phage DNA for confirmation of their be- longing to certain species. RESULTS: Cumulative activity of 6 mono-species mixtures of virulent phages was shown to be similar to lytic activity of commercial therapeutic mixtures used against P. aeruginosa infections. 54 of 55 strains of clinical isolates of P: aeruginosa showed sensitivity to experimental mixtures composed of mono-species mixtures of bacteriophages. 53 strains were lysed by commercial preparations. Wherein the possibility of accidental inclusion of moderate -bacteriophages in the experimental mixture is excluded. CONCLUSION: A possibility of creation of highly active therapeutic antibacterial preparations against P. aeruginosa using mono-species mixtures of 6 species of lytic bacteriophages is shown Use of such a mixture in therapy of lung infections reduces the risk of emergence of bacterial strains with increased virulence and patho- genicity during prolonged administration.

Nitric oxide participates in the intestinal pathology associated with murine syngeneic graft-versus-host disease.

Syngeneic graft-versus-host disease (SGVHD) develops following lethal irradiation, reconstitution with syngeneic bone marrow, and treatment with a short course of cyclosporin A (CsA) therapy. The disease is characterized by the development of a T helper cell type 1-like cytokine response [interleukin (IL)-12, interferon-gamma (IFN-gamma), and tumor necrosis factor alpha], and macrophage activation is central to development of the syndrome. It has been shown that nitric oxide (NO) participates significantly in the development of allogeneic GVHD. Studies were initiated to determine if NO participates in the pathology associated with SGVHD. Significant increases in inducible NO synthase (iNOS) mRNA and circulating NO were found in the tissues of SGVHD versus control animals. Treatment of SGVHD animals with the iNOS inhibitor aminoguanidine (AG) reversed the pathology associated with this disease. Furthermore, AG treatment reduced the production of IL-12 and IFN-gamma mRNA in the colons of CsA-treated mice. These studies demonstrate that NO participates in the pathological processes that are associated with the development of murine SGVHD.

Induction of syngeneic graft-versus-host disease in LPS hyporesponsive C3H/HeJ mice.

Syngeneic GVHD (SGVHD) develops following syngeneic bone marrow transplantation and treatment with cyclosporine A. Previous studies have demonstrated a role for IL-12, IFN-gamma, and TNF-alpha in the development of murine SGVHD. Macrophages can be activated to secrete IL-12 and TNF-alpha via a T-cell-dependent or T-cell-independent pathway (LPS or bacterial products). Studies were designed to determine if LPS participated in the development of SGVHD in C3H/HeN (LPS-responsive) and C3H/HeJ (LPS-hyporesponsive) mice. C3H/HeJ and C3H/HeN mice had similar levels of disease induction and pathology. Following induction of SGVHD, treatment of C3H/HeN, but not C3H/HeJ, mice with a sublethal dose of LPS resulted in mortality. However, neutralization of IL-12 abrogated the development of disease in C3H/HeJ mice, demonstrating that activated macrophages and their products participated in the development of SGVHD in these animals. These data suggested that LPS responsiveness was not a predisposing factor for SGVHD induction.

Bleomycin-induced pulmonary fibrosis is independent of eosinophils.

Eosinophils have been shown to increase in tissues during many fibrotic conditions and consequently have been suggested to contribute to the development of fibrosis. This study tested the hypothesis that eosinophils are essential in the development of lung fibrosis in mice in response to bleomycin (BLM). Anti-IL-5 antibody was administered intraperitoneally into mice 2 h prior to endotracheal BLM inoculation and thereafter, every other day. Lung eosinophilia was evaluated by measurement of eosinophil peroxidase activity and confirmed by eosinophil counts in histologic sections. Lung fibrosis was evaluated by hydroxyproline content and confirmed by collagen staining in histological sections. Results demonstrated that BLM induced pronounced lung eosinophilia, which was maximal 7 days after BLM treatment and remained elevated through day 14, in C57B1/6 SCID mice and CBA/J mice. In contrast, eosinophilia was a minor component in the lungs of wildtype C57B1/6 mice after BLM treatment, although lung fibrosis developed similarly in all three strains of mice. Treatment with anti-IL-5 completely abrogated eosinophilia but failed to block pulmonary fibrosis induced by BLM in all mouse strains, including C57B1/6 SCID, wildtype C57B1/6 mice, and CBA/J mice. Analysis of cytokine mRNA by RNase-protection assay in C57B1/6 SCID mice indicated that BLM treatment caused enhanced expression of the cytokines, TNF-alpha, and IL-6 at days 3, 7, and 14 post-BLM inoculation, regardless of whether eosinophils were depleted by anti-IL-5. Finally, the importance of eosinophils in lung fibrosis was examined in IL-5 gene knockout mice (IL-5tm1Kopf). BLM treatment induced significant lung fibrosis in IL-5 knockout mice in the absence of eosinophilia. These findings indicate that eosinophils are not an absolute requirement for BLM-induced pulmonary fibrosis in the mouse.

High-dose carmustine, thiotepa and etoposide followed by autologous bone marrow rescue for the treatment of high risk central nervous system tumors.

Forty-two patients (29 newly diagnosed) with high grade gliomas (n = 37), medulloblastoma (n = 2) or non-biopsied tumors (n = 3) with supratentorial (n = 24), brain stem (n = 11), posterior fossa (n = 5) or spinal (n = 2) location were eligible for this study with adequate organ function and no bone marrow tumor infiltration. Median patient age was 12.2 years (range, 0.7-46.8). A total of 600 mg/m2 BCNU, 900 mg/m2 thiotepa and 1500 or 750 mg/m2 etoposide (VP-16) was administered followed by autologous bone marrow reinfusion (ABMR). Twenty-one newly diagnosed patients received local irradiation (RT) post ABMR. Nine early deaths were observed (21%), as well as one secondary graft failure. Half of the patients aged 18 years or older experienced toxic deaths, whereas only 15% of patients younger than 18 years experienced toxic death (P = 0.05). Of 25 evaluable newly diagnosed patients, 20% achieved complete remission (CR) and 4% partial remission (PR), while 28% remained in continuing complete remission (CCR) and 44% remained with stable disease prior to RT. Of eight evaluable patients with recurrent disease, one achieved CR and two PR, while one remained in CCR and four with stable disease for 1 to 110.2 months. Overall survival was 36%, 24% and 17% at 1, 2 and 3 years following ABMR, with three newly diagnosed patients and one patient treated for recurrent disease being alive, without disease progression 64.4, 67.0, 86.3 and 110.2 months after ABMR, respectively. The combination of high-dose BCNU/ thiotepa/VP-16 has substantial toxicity but definite activity for high risk CNS tumors. Similar protocols with lower toxicity merit further evaluation in both newly diagnosed and recurrent CNS tumors.

Functional brain mapping using positron emission tomography scanning in preoperative neurosurgical planning for pediatric brain tumors.

OBJECT: The purpose of this report is to demonstrate the value of functional brain mapping using the positron emission tomography (PET) method for preoperative neurosurgical planning in children with brain tumors. Brain maps were used to characterize the relationship between potentially resectable tumors and functionally eloquent brain areas. METHODS: Five children, ranging in age from 3 to 13 years, with hemispheric brain tumors adjacent to eloquent cortex were studied. Magnetic resonance (MR) imaging was used to identify the brain tumors; PET imaging after injection of [18F] fluorodeoxyglucose (FDG), [11C]L-methionine (CMET), or a combination of the two was performed to grade the tumors; and a [15O] H2O uptake study was used to characterize the anatomical relationships of the tumors to functional cortex. The cortical activation maps were obtained during control periods and during behavioral tasks and were used to document motor, visual, and speech and language organizational areas. Wada tests were performed in two patients. Language and speech activation was concordant with the results of Wada testing. CONCLUSIONS: Functional brain mapping using PET scans and coregistered MR images provided the neurosurgeon with precise definitions of structural and functional cortical areas; this altered surgical management in some cases and/or was used to predict outcome. The combination of PET imaging with FDG and/or CMET and measurements of [15O] water uptake was useful in characterizing and grading tumors and instrumental in achieving effective neurosurgical planning. Postoperative results in the five cases suggest that preoperative functional brain mapping has the potential to improve outcome by defining a surgical plan to maximize resection and minimize the risk of neurological sequelae.

Positron emission tomography using [18F] fluorodeoxyglucose and [11C] l-methionine to metabolically characterize dysembryoplastic neuroepithelial tumors.

Dysembryoplastic neuroepithelial tumors are unique and benign congenital tumors occurring frequently in children and adolescents. Differentiation from other low-grade tumors is important for management. Five patients with confirmed dysembryoplastic neuroepithelial tumors were studied with positron emission tomography using glucose and protein metabolic uptake in an attempt to categorize these tumors metabolically. Functional brain mapping also was obtained to aid in operative management. Results of the study conclude that dysembryoplastic neuroepithelial tumors, although having similar neuroimgaing characteristics to other low-grade tumors, are distinguished by a unique metabolic profile. They are inactive tumors with no significant glucose or protein metabolic activity. The combination of preoperative positron emission tomographic metabolic studies with functional brain mapping allowed for prediction of tumor type, defined eloquent areas of cortical function, and improved approach and resection of the tumors with minimal risk of neurologic impairment.

Interleukin-10 enhances immune responses to pneumococcal polysaccharides and sheep erythrocytes in young and aged mice.

Antibody responses to pneumococcal polysaccharides are decreased in aged mice. Using a system to measure murine antibody responses to the Pnu-Imune vaccine, here we demonstrate that interleukin-10 (IL-10) has an adjuvant effect in enhancing the vaccine response in the aged. IL-10 increased the vaccine responses of B cells from aged mice in vitro only if either T cells or macrophages were also present. The need for T cells or macrophages could be substituted by cytokines such as IL-1 or IL-5, which are normally made by these accessory cells. Thus, IL-10 appeared to act on B cells directly but it worked in conjunction with other cytokines to induce an antigen specific response. In vivo studies showed that IL-10 administration enhanced antibody responses not only to thymic independent antigens but also to thymic-dependent antigens such as sheep erythrocytes. These data suggest that IL-10 may be useful in enhancing vaccine-specific responses in situations in which the host is immunocompromised.

Intra-abdominal embryonal rhabdomyosarcoma in an adult.

Rhabdomyosarcoma is an uncommon neoplasm in the adult population. Sporadic cases of primary rhabdomyosarcoma arising in the abdomen have been reported, but these cases are limited almost exclusively to the pediatric population. We report a well-documented case of primary intra-abdominal rhabdomyosarcoma in a 57-year-old woman. The patient presented with a pelvic mass and an elevated serum CA 125 and was referred to gynecologic oncologists at our institution for a presumed primary gynecologic malignancy. Intraoperatively, amorphous gelatinous tumor comprised a large portion of the peritoneal cavity. Surgical exploration of the abdomen failed to implicate any specific organ as the site of origin of the tumor. The overall histologic pattern of the resected tumor was most consistent with embryonal type rhabdomyosarcoma. To our knowledge this is the first well-documented case report of non-hepatobiliary, adult, intra-abdominal embryonal rhabdomyosarcoma in the English language literature. The presentation of a rare adult sarcoma mimicking a gynecologic malignancy was an unusual feature that complicated the diagnosis in this case.

Idiopathic pneumonia syndrome after allogeneic bone marrow transplantation in mice. Role of pretransplant radiation conditioning.

Idiopathic pneumonia syndrome (IPS) is a significant clinical problem encountered among patients treated with bone marrow transplantation (BMT). IPS is identified as an inflammatory lung disease characterized by diffuse interstitial pneumonitis and alveolitis leading to interstitial fibrosis in the absence of an identifiable infectious agent. In an earlier study we characterized a murine model of IPS following allogeneic BMT that exhibits several features of human IPS. In this report we show that the lung represents a unique target of post-BMT disease in this model. The kinetics of developing lung disease were found to be markedly different from the kinetics of graft-versus-host disease in other tissues such as liver, colon, ear, skin, and tongue. Mice transplanted by our standard protocol with T-cell-depleted semiallogeneic donor bone marrow plus donor spleen cells in the absence of pretransplant radiation conditioning did not develop lung inflammation or fibrosis characteristic of IPS. Pretransplant radiation conditioning in the absence of BMT also failed to cause IPS, demonstrating an important role for radiation conditioning in the development of BMT-related IPS. The occurrence of lung disease post-BMT was found to be dependent on radiation conditioning in a dose-dependent manner. Finally, thoracic irradiation alone was demonstrated to be sufficient in causing IPS in mice transplanted with bone marrow plus spleen cells, albeit with reduced severity. Based on these findings, we conclude that pretransplant radiation conditioning plays an important role in the development of IPS following allogeneic BMT.

Rejection of an MHC class II negative tumor following induction of murine syngeneic graft-versus-host disease.

Cyclosporin A (CsA) has been used clinically to induce graft-versus-host disease following autologous bone marrow transplantation in an attempt to destroy residual leukemia cells and reduce relapse. To analyze the antitumor potential of murine syngeneic graft-versus-host disease (SGVHD), C3H/HeN mice were lethally irradiated, reconstituted with T cell-depleted syngeneic bone marrow (ATBM) and treated with CsA for 21 days. Graft-versus-leukemia activity was assessed by challenging groups of olive oil-treated control ATBM (OO-ATBM) and CsA-treated (CsA-ATBM) mice 1 week after CsA therapy with graded doses of the syngeneic 38C13 B cell lymphoma. Following CsA treatment, up to 70% of CsA-ATBM developed SGVHD and more than 70% of the animals injected with 500 38C13 cells exhibited long-term survival (MST >80 days). In contrast, none of the OO-ATBM control mice developed SGVHD, and more than 75% of these mice died following injection of 500 38C13 tumor cells (MST = 34 days). Long-term survivors were not resistant to tumor challenge suggesting that tumor-specific immunity did not develop. Finally, class II negative 38C13 cells cultured in IL-4 or IL-10 were not inducible for MHC class II molecules, demonstrating that class II-independent antitumor mechanisms exist in SGVHD mice.

T cell independence of bleomycin-induced pulmonary fibrosis.

The role of T cells and cytokines in bleomycin (BLM)-induced fibrosis was evaluated in susceptible and resistant strains of normal and SCID mice. Histology and hydroxyproline analysis showed that BLM induced pulmonary fibrosis in C57BL/6 and (C57BL/6 x BALB/c)F1 mice, whereas BALB/c mice were resistant to the disease. To test whether lymphocytes were required for the induction of BLM-induced pulmonary fibrosis, SCID mice were injected intratracheally with BLM and evaluated for the development of pulmonary inflammation and fibrosis. Similar morphological changes and increases in hydroxyproline were observed in both C57BL/6 SCID and (C57BL/6 x CB.17)F1 SCID animals compared to those seen in wild-type C57BL/6 and (C57BL/6 x BALB/c)F1 mice. In contrast, CB.17 SCID mice, which are genetically similar to BALB/c mice, were resistant to disease induction. Analysis of the cellular infiltrate in BLM-treated C57Bl/6 SCID mice confirmed a lack of T cells in the lungs of SCID mice and demonstrated a pronounced accumulation of eosinophils in areas of developing pulmonary fibrosis. NK cells were significantly elevated in untreated SCID mice and did not increase further after BLM treatment. Analysis of selected cytokines 1 day after initiation of BLM-induced pulmonary fibrosis indicated that the levels of TNF-alpha and IFN-gamma appeared to segregate with fibrosis in both the SCID and wild-type mice. The data demonstrate that T cells are not required for the induction of fibrosis by BLM and suggest that responses by non-lymphoid cells may be sufficient for the induction of fibrosis.

Inhibition of natural killer cell activity in mice treated with tobacco specific carcinogen NNK.

Among the different chemicals present in tobacco and tobacco smoke, 4-(methylnitrosamine)-1-(3-pyridyl)-1-butanone (NNK) is the most potent carcinogen. In the present study the immunosuppressive effect of NNK was investigated in laboratory animals by analyzing the antitumor immune responses. Mice of B6C3F1 strain were treated with different doses of NNK by IP and assayed for natural killer cell activity by the lysis of 51Cr-labeled YAC-1 lymphoma cells. The control mice received physiological saline. The results showed a significant inhibition of natural killer cell activity in the spleen cells of mice treated with 100 or 250 mg/kg NNK. In contrast to the high-dose NNK group, treatment of mice with lower doses of NNK like 10 or 50 mg/kg had no significant effect on the natural killer cell activity. In addition to spleen, the natural killer cell activity was also suppressed in the hilar lymph nodes and lung cells of NNK-treated mice. The clearance of 125I labeled YAC-1 tumor cells was also reduced from the lungs of mice injected with NNK. Further, the metastatic potential of B16F10 melanoma cells was significantly higher, as evidenced by the increased lung tumor nodules in the high-dose NNK-treated mice. The decreased antitumor immune response in the carcinogen-treated mice was not due to a decrease of NK cells, because flow cytometric analysis indicated no change in the frequency of NK 1.1+ cells between control and treated animals. However, there was an increased plasma cortisone levels in the carcinogen-treated mice compared to control animals. Injection of mice with poly I:C or interleukin-12 was able to restore natural killer cell activity in the tobacco carcinogen-treated mice.

Role of virus replication in a murine model of AIDS-associated interstitial pneumonitis.

One of the major complications of HIV infection is the development of interstitial pneumonitis (IP). IP is characterized by lymphocytic infiltration of the lung and may lead to respiratory failure in some cases. The etiology of IP is unknown although it is likely the result of an antiviral or autoimmune response occurring in the lung. To determine the role of viral replication in the development of IP, AZT was evaluated for the ability to inhibit development of lung inflammation in a murine model of retrovirus-associated IP. Mice were infected with LP-BM5 retrovirus, which induces murine AIDS. Infected mice develop IP by 4 weeks postinfection characterized by infiltration of the lung with activated T cells, B cells, and macrophages. Virus could be detected in the lungs of these mice by 2 weeks postinfection and persisted throughout the course of disease. To determine if reduction in viral load affected the disease process, infected mice were treated with AZT for varying periods postinfection and analyzed for the development of IP. Treatment with AZT resulted in a treatment time-dependent reduction of viral RNA in the lungs of infected mice compared to untreated infected mice. The reduction of viral burden in the lungs correlated with a reduction in the severity of IP and decreased production of the proinflammatory cytokines interleukin (IL)-1 beta and interferon (IFN)-gamma. These results suggest that continuous viral replication in the lung contributes to the pathogenesis of IP.

Role of T cell subsets in the development of AIDS-associated interstitial pneumonitis in mice.

Idiopathic interstitial pneumonitis (IP), characterized by lymphocytic infiltration of the lung and pulmonary dysfunction, is a major noninfectious complication of human immunodeficiency virus (HIV) infection. The role of the CD4+ and CD8+ T cell populations and INF-gamma in the development of IP were analyzed using a murine model of retroviral-associated IP. Infected mice depleted of CD8+ T cells developed IP similarly to untreated infected mice, suggesting that the CD8+ T cell population does not play a role in IP. Furthermore, depletion of CD8+ T cells did not alter the level of viral RNA in lungs, suggesting that cytotoxic T cells may not serve a role in controlling virus burden in lungs. In contrast, depletion of CD4+ T cells in infected mice prevented the development of IP and inhibited inflammatory cytokine expression, suggesting that CD4+ T cells are important for the development of IP. IFN-gamma -/- mice infected with virus for 10 weeks developed IP, although the severity of lymphocytic infiltration was substantially reduced compared to infected wild-type mice. The data suggest that persistent viral antigen in the lung may drive a CD4+ T cell-mediated immune response, resulting in the chronic production of IFN-gamma which amplifies a chronic inflammatory response in the lung resulting in tissue injury.

High dose chemotherapy with autologous bone marrow rescue for children with diffuse pontine brain stem tumors. Children's Cancer Group.

PURPOSE: Diffuse pontine tumors are highly lethal, and there are few long-term survivors with the standard treatment of external beam irradiation. We investigated the effectiveness of high-dose thiotepa and etoposide-based chemotherapy regimens with autologous bone marrow rescue (ABMR) in children with pontine tumors. PATIENTS AND METHODS: Sixteen children with diffuse pontine tumors were treated. Ten had resistant or recurrent tumors. All ten had previously received irradiation; five had also received chemotherapy and one, beta-interferon. Three high-dose chemotherapy regimens were employed. Six patients received three days of thiotepa (300 mg/m2/day) and etoposide (250-500 mg/m2/day) (TE); two received three days of carmustine (BCNU) (200 mg/m2/day divided every 12 hours) followed by TE (BTE); and two received three days of carboplatin (500 mg/m2/day) followed by TE (CTE). Six other patients had newly-diagnosed tumors and had not received any prior treatment. They all received the BTE regimen and subsequently were treated with hyperfractionated irradiation (7200-7800 cGy) beginning approximately six weeks post-ABMR. RESULTS: There were two toxic deaths (13%), both in previously treated patients, due to multiorgan system failure and Candida septicemia in one case each. Median survival of the patients with resistant or recurrent disease was 4.7 months (range 0.1-18.7) from time of ABMR. Median survival of the newly-diagnosed patients was 11.4 months (range 7.6-17.1) from the time of ABMR. CONCLUSION: High-dose chemotherapy utilizing these regimens followed by ABMR did not appear to prolong survival compared to conventional therapy in these children with pontine tumors. Alternative strategies need to be developed for this highly lethal disease.

Inhibition of graft-versus-host disease. Use of a T cell-controlled suicide gene.

Graft-vs-host disease (GVHD) after allogeneic bone marrow transplantation is associated with significant morbidity and mortality. T cell depletion of the marrow graft, which is currently used to prevent GVHD, has been shown to result in increased graft failure and leukemia relapse. To explore the feasibility of controlling GVHD, transgenic mice with the herpes simplex virus thymidine kinase suicide gene linked to the IL-2 promoter were used as a source of T cells to induce GVHD, which would be modulated with ganciclovir. Injection of herpes simplex virus thymidine kinase transgenic B10.A(5R) spleen cells into lethally irradiated DBA/2 mice resulted in severe acute GVHD. Treatment of the recipient mice with ganciclovir significantly inhibited GVHD-mediated weight loss and mortality and reduced the severity of inflammation in the target organs of GVHD.

Enhanced graft-versus-host disease in older recipient mice following allogeneic bone marrow transplantation.

The incidence and severity of GVHD following bone marrow transplantation increases with recipient age. The role of recipient age on the development of GVHD was analyzed in a semi-allogeneic (C57BL/6-->(C57BL/6 x DBA/2)F1) murine GVHD system. Young adult (2 months) and old (12-14 months) recipient mice were lethally irradiated and reconstituted with young adult T cell-depleted bone marrow (ATBM) or ATBM and young spleen cells. A significantly higher percentage of old vs young recipients developed lethal GVHD. Furthermore, while pre-transplant conditioning with irradiation was not required to observe increased mortality in old recipients, irradiation predisposed the older animals for a more severe course of GVHD, suggesting that GVHD occurred in old compared to young animals in the absence of pre-transplant conditioning but was exacerbated by irradiation. Histologically, the immunological responses in the GVHD target organs were more severe in the old GVHD animals. In support of this observation, increased spontaneous proliferation was observed using lymphoid cells isolated from old vs young GVHD mice. These findings demonstrate that old recipients develop a more severe course of GVHD following BMT, and may present a unique opportunity to study age-related factors in the generation of GVHD.

Use of positron emission tomography for presurgical localization of eloquent brain areas in children with seizures.

Successful surgical management of a neoplastic or nonneoplastic seizure focus in close proximity to or within eloquent brain areas relies on precise delineation of the relationship between the lesion and functional brain areas. The aim of this series was to validate the usefulness and test the efficacy of noninvasive presurgical PET mapping of eloquent brain areas to predict surgical morbidity and outcome in children with seizures. To identify eloquent brain areas in 15 children (6 female and 9 male; mean age 11 years) with epileptogenic lesions PET images of regional cerebral blood flow were performed following the administration of [(15)O]water during motor, visual, articulation, and receptive language tasks. These images with coregistered magnetic resonance (MR) images were then used to delineate the anatomic relationship of a seizure focus to eloquent brain areas. Additional PET images using [18F]fluoro-2-deoxy-D-glucose (FDG) and [11C]methionine (CMET) were acquired to help localize the seizure focus, as well as characterize the lesion. Patient surgical management decisions were based on PET mapping in combination with coregistered MR images, PET-FDG findings, and the anatomic characteristics of the lesion. At follow-up 1-26 months after surgery, all patients that underwent temporal lobectomy (9 patients) and extratemporal resection (4 patients) for a neoplastic or nonneoplastic seizure focus are seizure-free with minimal postoperative morbidity. Of prime importance, no child sustained a postoperative speech or language deficit. PET imaging was also well tolerated without procedural complications. Based on PET mapping, a nonoperative approach was used for 2 children and a biopsy only was used in one child. When cortical injury involved prenatally determined eloquent cortex, PET demonstrated reorganization of language areas to new adjacent areas or even to the contralateral hemisphere. Integration of anatomical and functional data enhanced the surgical safety, defined optimal surgical approach, delineated the seizure focus from eloquent brain areas, facilitated maximum resection and optimized the timing of surgery, thereby minimizing surgical morbidity while maximizing surgical goals. PET measurements of FDG and CMET uptake were also helpful in localizing the seizure focus and grading the tumors. PET used for brain mapping in children provides the surgeon with strategic preoperative information not readily attainable with traditional invasive Wada testing or intraoperative cortical stimulation. PET mapping may also improve the outcome of extratemporal resections by allowing aggressive seizure focus resection. In addition, serial brain maps may optimize timing for surgical intervention by demonstrating reorganization of eloquent cortex often seen in younger children after cortical injury. Our results suggest that noninvasive presurgical brain mapping has the potential to reduce risk and improve neurologic outcome.