Biomedical subjects

E R Lawlor

Publications and source records attributed to E R Lawlor.

8 recordsLinked to original sources

PubMed1998

The Ewing tumor family of peripheral primitive neuroectodermal tumors expresses human gastrin-releasing peptide.

The Ewing tumor family of peripheral primitive neuroectodermal tumors (pPNETs) are characterized by chromosomal translocations leading to EWS-ETS gene fusions. These hybrid genes express chimeric proteins that are thought to act as aberrant transcription factors. We therefore used differential display-PCR to compare gene expression patterns in pPNET cell lines with those of other small round cell tumors (SRCTs) of childhood. This technique detected differential expression of sequences corresponding to human gastrin-releasing peptide (GRP) in pPNET cell lines but not in other SRCT cell lines. Subsequent Northern and reverse transcription-PCR analysis of SRCT cell lines confirmed GRP positivity in all pPNET lines tested. Of primary tumors tested by reverse transcription-PCR, GRP expression was found in 7 (44%) of 16 pPNETs but in no other primary SRCTs examined. Expression of the GRP receptor gene was demonstrable in 55% of pPNET cell lines and 25% of primary pPNET tumors but also in several other SRCTs. Radioimmunoassays and immunohistochemistry confirmed expression of bioactive GRP peptide in pPNET cell lines and primary tumors, respectively. Moreover, in vitro growth of a pPNET cell line was slowed by treatment with a GRP receptor antagonist and accelerated by a GRP receptor agonist. GRP is a known autocrine growth factor in small cell lung cancer and other neuroendocrine tumors. Its expression in pPNETs provides further evidence for a neuroectodermal histogenesis of these tumors and suggests that autocrine growth of this family of tumors may be at least partially regulated by GRP.

Artificial Gene Fusion↗

PubMed1998

Successful use of cyclosporine A in the treatment of refractory thrombotic thrombocytopenic purpura.

Thrombotic thrombocytopenic purpura (TTP) is, in most cases, treatable with plasma exchange therapy (PLEX). Rarely, patients do not respond to PLEX or develop refractory disease despite an initial remission. In these cases, treatment options are limited and the response to established alternative therapies is often disappointing. We report the case of a paediatric patient with TTP who developed refractory disease after an initial response to PLEX. She was subsequently treated with cyclosporine A and showed an immediate and sustained response. CSA may be a safe and effective therapy for patients with refractory TTP and should be studied in randomized, prospective clinical trials.

Adolescent↗

PubMed1998

Peripheral primitive neuroectodermal tumors in adults: documentation by molecular analysis.

PURPOSE: The Ewing tumor (ET) family of peripheral primitive neuroectodermal tumors (pPNETs) are primitive small round-cell tumors (SRCTs) of the bone and soft tissue that occur predominantly in children and adolescents. However, pPNETs only rarely enter the differential diagnosis of bone and soft tissue SRCTs in adults. Recently, gene fusions between the EWS gene and different members of the ETS transcription factor family have been shown to occur in virtually all pPNETs and thus constitute a pathognomonic marker for this tumor subclass. The aim of the present study was to document EWS/ETS fusion gene expression in suspected pPNETs of adults as objective evidence for the existence of this tumor family in older patients. PATIENTS AND METHODS: The three contributing molecular diagnostic laboratories retrospectively compiled a cohort of all SRCT cases in which EWS/ETS gene fusions had been shown by molecular analysis. This cohort was surveyed for cases that occurred in patients aged 40 years or older, which were then analyzed for their clinical and pathologic features. RESULTS: Nine patients between 40 and 65 years of age were found to have tumors positive for EWS/ETS gene fusions. Standard histopathologic and clinical features of these cases, other than age, were similar to those of childhood pPNETs. Patients were initiated on appropriate therapy after molecular analysis confirmed the diagnosis of pPNET. CONCLUSION: Identification of an EWS/ETS gene fusion is useful in providing objective evidence of the diagnosis of pPNET in patients over the age of 40 years. This diagnosis should be considered in adults who present with bone and soft tissue SRCTs and appropriate biopsy specimens should be collected for molecular analysis at the time of diagnosis.

Adult↗

PubMed1998

EWS-FLI1 fusion transcript structure is an independent determinant of prognosis in Ewing's sarcoma.

PURPOSE: More than 90% of Ewing's sarcomas (ES) contain a fusion of the EWS and FLI1 genes, due to the t(11;22)(q24;q12) translocation. At the molecular level, the EWS-FLI1 rearrangements show great diversity. Specifically, many different combinations of exons from EWS and FLI1 encode in-frame fusion transcripts and result in differences in the length and composition of the chimeric protein, which functions as an oncogenic aberrant transcription factor. In the most common fusion type (type 1), EWS exon 7 is linked in frame with exon 6 of FLI1. As the fundamental pathogenetic lesion in ES, the molecular heterogeneity of these fusion transcripts may have functional and clinical significance. PATIENTS AND METHODS: We performed a clinical and pathologic analysis of 112 patients with ES in which EWS-FLI1 fusion transcripts were identified by reverse-transcriptase polymerase chain reaction (RT-PCR). Adequate treatment and follow-up data were available in 99 patients treated with curative intent. Median follow-up in these 99 patients was 26 months (range, 1 to 140 months). Univariate and multivariate survival analyses were performed that included other prognostic factors, such as age, tumor location, size, and stage. RESULTS: Among the 99 patients suitable for survival analysis, the tumors in 64 patients contained the type 1 fusion and in 35 patients contained less common fusion types. Stage at presentation was localized in 74 patients and metastatic in 25. Metastases (relative risk [RR] = 2.6; P = .008), and type 1 EWS-FLI1 fusion (RR = 0.37; P = .014) were, respectively, independent negative and positive prognostic factors for overall survival by multivariate analysis. Among 74 patients with localized tumors, the type 1 EWS-FLI1 fusion was also a significant positive predictor of overall survival (RR = 0.32; P = .034) by multivariate analysis. CONCLUSION: EWS-FLI1 fusion type appears to be prognostically relevant in ES, independent of tumor site, stage, and size. Further studies are needed to clarify the biologic basis of this phenomenon.

Adolescent↗

PubMed1997

Metastatic primitive neuroectodermal tumour of the ovary: successful treatment with mega-dose chemotherapy followed by peripheral blood progenitor cell rescue.

Primitive neuroectodermal tumours (PNET) of the ovary are rare, aggressive tumours which are associated with high morbidity and mortality. Previously reported cases have shown limited response to therapy in patients presenting with metastatic disease and survival rates have been discouragingly low. We report the case of a 13-year-old girl who presented with a primary ovarian PNET and extensive metastatic disease. Pathologic studies confirmed the neural origin of the tumour and its morphologic appearance of neuroblastoma. Incomplete surgical resection was followed by treatment with aggressive multi-agent chemotherapy including cis-platinum, etoposide, cyclophosphamide, anddoxorubicin as per a neuroblastoma treatment protocol. Complete clinical remission ensued and she received consolidative therapy with myeloablative doses of thiotepa, melphalan, and carboplatin followed by autologous peripheral blood progenitor cell rescue. All therapy was well tolerated and the patient remains in complete remission with no evidence of disease 18 months from presentation. Mega-dose chemotherapy followed by progenitor cell rescue may provide optimal therapy for patients presenting with metastatic ovarian PNET.

Adolescent↗

PubMed1997

Thrombotic thrombocytopenic purpura: a treatable cause of childhood encephalopathy.

We describe two patients less than 13 years of age with thrombotic thrombocytopenic purpura, a rare disorder in childhood. Both children were treated with plasma exchange therapy, which resulted in a rapid resolution of symptoms. This disorder is a cause of childhood encephalopathy, which can be treated effectively with plasma exchange.

Brain Diseases↗

PubMed1996

Transient erythroporphyria of infancy.

We describe a neonate with hemolytic disease of the newborn in whom a photosensitivity eruption developed during phototherapy for treatment of hyperbilirubinemia. Free erythrocyte protoporphyrin and zinc protoporphyrin levels were markedly elevated during the neonatal period. Porphyrin levels were normal at 19 weeks of age. The infant had residual skin atrophy and showed clinical and radiologic evidence of kernicterus. The pathogenesis of transient porphyrinemia associated with hemolytic disease of the newborn is unclear.

Humans↗

PubMedDate not supplied

Immunosuppressive therapy: a potential alternative to bone marrow transplantation as initial therapy for acquired severe aplastic anemia in childhood?

PURPOSE: Currently bone marrow transplantation (BMT) with an HLA-identical sibling donor is recommended as optimal therapy for children with acquired severe aplastic anemia (SAA). Immunosuppressive therapy (IST) has become a very successful initial therapy for SAA in children lacking a related bone marrow donor. We wished to evaluate whether current IST regimens may be as efficacious as BMT. PATIENTS AND METHODS: A retrospective review identified children treated for SAA over a 12-year period. Children with a related donor received a BMT. Children lacking a donor were treated with IST followed by a "rescue" BMT if IST was ineffective. IST consisted of anti-thymocyte globulin and steroid +/- cyclosporine A. Transfusion independence and survival rates were compared between the two groups. RESULTS: Twenty-seven children were identified. Nine received a related BMT; seven of these survive and are transfusion independent (median follow-up 54 months). Sixteen of 18 patients who received IST are transfusion-independent survivors, including three of four patients who received a rescue BMT (median follow-up 33.5 months). Actuarial survival is 75% (95% CI = 45%, 105%) and 92% (95% CI = 78%, 107%) for the BMT and IST groups, respectively (p = 0.15). Severe toxicity was not experienced by any patient as a result of IST. CONCLUSIONS: Equivalent rates of transfusion independence and survival were experienced by patients receiving BMT and IST. We propose that a prospective trial be undertaken to evaluate IST as initial therapy in all children with SAA, to be followed by BMT if there is inadequate response.

Adolescent↗