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Biomedical subjects

M C O'Leary

Publications and source records attributed to M C O'Leary.

8 recordsLinked to original sources
PubMed1998

Screening of Australian medicinal plants for antiviral activity.

Extracts of 40 different plant species used in the traditional medicine of the Australian Aboriginal people have been investigated for antiviral activity. The extracts have been tested for activity against one DNA virus, human cytomegalovirus (HCMV) and two RNA viruses, Ross River virus (RRV) and poliovirus type 1, at non-cytotoxic concentrations. The most active extracts were the aerial parts of Pterocaulon sphacelatum (Asteraceae) and roots of Dianella longifolia var. grandis (Liliaceae), which inhibited poliovirus at concentrations of 52 and 250 microg/ml, respectively. The extracts of Euphorbia australis (Euphorbiaceae) and Scaevola spinescens (Goodeniaceae) were the most active against HCMV. Extracts of Eremophila latrobei subsp. glabra (Myoporaceae) and Pittosporum phylliraeoides var. microcarpa (Pittosporaceae) exhibited antiviral activity against RRV.

Antiviral Agents↗
PubMed1995

Pelvic neuroblastoma--implications for a new favorable subgroup: a Children's Cancer Group experience.

BACKGROUND: The survival in neuroblastoma is influenced by patient age, disease stage, tumor site, and several biologic factors. This study was undertaken to determine if primary pelvic lesions are associated with an unusually favorable outcome. METHODS: Nine hundred eighty-six patients registered on Children's Cancer Group studies from 1980 to 1993 were reviewed, and 41 (4.3%) were found to have pelvic tumors. Survival was analyzed, and correlations among age, stage of disease, surgical resectability, histopathology, serum ferritin, and N-myc oncogene amplification were evaluated. RESULTS: Age at diagnosis was comparable between patients with pelvic and nonpelvic tumors. Disease distribution was similar, with stages III and IV comprising 78% (32 of 41) of pelvic lesions compared with 73% (692 of 945) for nonpelvic tumors. There was no outcome difference in favorable stages (I, II, and IV-S), with 3-year progression-free survival rates of 88% and 82% for pelvic and nonpelvic sites, respectively. However, in stages III and IV, the 3-year progression-free survival was 70% for pelvic lesions compared with 47% for nonpelvic tumors (p = 0.04). Some favorable biologic factors were more common in children with pelvic lesions. CONCLUSIONS: The pelvis is an unusual primary site for neuroblastoma but represents a more favorable prognostic subgroup, which is most evident in advanced-stage disease.

Adolescent↗
PubMed1995

Role of myeloablative therapy in improved outcome for high risk neuroblastoma: review of recent Children's Cancer Group results.

The use of new strategies for dose intensification using peripheral blood stem cell or autologous purged bone marrow rescue has raised expectations for cure in advanced neuroblastoma, although conflicting reports exist regarding the efficacy of these approaches. Using risk groups based on both biological and clinical staging, the Children's Cancer Group (CCG) has conducted a series of pilot studies to test new induction, consolidation and myeloablative regimens to attempt to improve outcome. We summarise below the outcome and prognostic factor analysis for the pilot chemotherapy trial, CCG-(CCG-321P2), and the use of high dose myeloablative chemoradiotherapy with allogeneic (CCG-321P1) or autologous purged bone marrow rescue (CCG-321P3) for high risk neuroblastoma patients who were progression-free at the end of induction chemotherapy. After autologous bone marrow transplantation (ABMT), progression-free survival (PFS) at 4 years was 38% (median follow-up 4 years). Prognostic factors for relapse after ABMT included pre-BMT disease status, bone marrow tumour content at harvest, extent of primary resection at diagnosis, and time to ABMT. MYCN amplification, age, stage, and pre-BMT myeloablative regimen were not significant. Allogeneic BMT did not have a better outcome than ABMT. In a retrospective, non-randomised comparison of ABMT and chemotherapy, there was a significant difference in PFS for stage IV patients. High risk subgroups possibly benefiting from ABMT could be identified, including those with tumour MYCN amplification, over 2 years at diagnosis, and those not in complete remission at the end of induction. A randomised prospective trial comparing myeloablative therapy with ABMT to continuous infusion consolidation chemotherapy is currently underway in CCG to determine the relative benefit.

Adolescent↗
PubMed1994

Allogeneic versus autologous purged bone marrow transplantation for neuroblastoma: a report from the Childrens Cancer Group.

PURPOSE: We have compared the toxicity, relapse rate, and progression-free survival (PFS) of high-risk neuroblastoma patients receiving identical induction therapy and myeloablative chemotherapy plus total-body irradiation (TBI) followed by allogeneic or autologous purged bone marrow transplantation (BMT). PATIENTS AND METHODS: Fifty-six patients with high-risk neuroblastoma underwent BMT at investigator and parent option if they did not have progressive disease after induction chemotherapy with cisplatin, cyclophosphamide, doxorubicin, and etoposide. After surgery and local radiation to residual tumor, myeloablative therapy consisting of etoposide, melphalan, cisplatin, and TBI was given followed by BMT. Patients with human leukocyte antigen (HLA)-compatible siblings received allogeneic bone marrow (n = 20). The remaining patients (n = 36) received autologous bone marrow that had undergone multimodality purging and had no remaining detectable tumor cells by immunocytology. RESULTS: Four of 20 allogeneic patients had a treatment-related death, compared with three of 36 autologous patients (P = .21). The relapse rate among allogeneic BMT patients was 69%, compared with 46% for autologous BMT patients (P = .14). The estimated PFS rates 4 years after BMT were 25% for allogeneic BMT patients and 49% for autologous BMT patients (P = .051). CONCLUSION: Overall outcome for patients with neuroblastoma given this same induction therapy followed by autologous purged marrow was similar to that with allogeneic marrow, although bias in patients selection cannot be excluded in a nonrandomized comparison.

Adolescent↗
PubMed1991

Aggressive surgery combined with intensive chemotherapy improves survival in poor-risk neuroblastoma.

One hundred eighteen children with metastatic (Childrens Cancer Study Group [CCSG] stage IV), extensive regional (stage III), or stage II neuroblastoma with N-myc amplification received an intensive chemotherapeutic regimen of cis-platinum, etoposide, doxorubicin, and cyclophosphamide combined with persistent aggressive attempts at complete primary tumor resection. Fourteen patients were unevaluable and 42 left the study to be placed on bone marrow transplant protocols. The remaining 62 children were evaluated in detail. Complete excision was eventually accomplished in 39 patients (63%), 23 of whom are disease-free survivors after 8 to 47 months (median, 20 months). Twenty-three patients underwent partial excision or biopsy of their lesion and only 6 are alive without evidence of disease (P = .0011). Timing of surgery or site of tumor did not influence surgical outcome. N-myc oncogene expression could not predict which lesions would be completely resectable. Surgical complications occurred 21% of the time but the impact on the clinical course and chemotherapy administration was minimal. The ipsilateral kidney was removed with the tumor in 18 cases, 14 of which were during complete resection. Twelve of these children are disease-free survivors. With new intensive chemotherapy capable of eliciting an effective response from primary and metastatic neuroblastoma, aggressive surgical approaches for complete tumor resection are warranted and can be expected to improve patient outcome.

Adolescent↗
PubMed1990

Total body irradiation and bone marrow transplantation for immunodeficiency disorders in young children.

Congenital immunodeficiency disorders such as severe combined immunodeficiency disease (SCID), Wiskott-Aldrich syndrome, and Chediak-Hegashi syndrome are almost uniformly fatal with most children dying before age one. Allogeneic bone marrow transplant (BMT) is the treatment of choice. Few of these children have matched donors. We use bone marrow processing techniques that allow us to utilize marrow from the parents. Children who lack HLA-identical donors are offered haploidentical, T-cell depleted parental BMTs. Some of these children do not have an immune deficiency severe enough to allow durable engraftment of processed mismatched bone marrow. Successful engraftment may necessitate the use of immunosuppression. Total body irradiation (TBI) is part of our intensive conditioning regimen for children with Wiskott-Aldrich and Chediak-Hegashi syndrome and most children with SCID who have undergone an unsuccessful prior mismatched, T-cell depleted BMT, or who have a high likelihood of donor marrow rejection based on pre-transplant immune function testing. TBI is considered extremely toxic therapy in infancy, with little information available on the acute and chronic effects. The 10 children presented in this report are among the youngest to have received TBI. Five patients were 2 to 6 months of age when they received TBI. The conditioning regimen for all patients was; antithymocyte globulin (25 mg/kg/day, x 3 days), cyclophosphamide (60 mg/kg/day, x 2 days), and TBI. 7.0 Gy TBI was given as a single dose AP-PA at approximately 15 cGy/min. Half value blocks shielded the brain, eyes and lungs. Six of 10 children were alive from 7 to 72 months post transplant.(ABSTRACT TRUNCATED AT 250 WORDS)

Bone Marrow Transplantation↗
PubMedDate not supplied

Pharmacokinetics of fluconazole in immune-compromised children with leukemia or other hematologic diseases.

STUDY OBJECTIVE: To describe the pharmacokinetics of fluconazole in immune-compromised children with leukemia or other hematologic disease. DESIGN: Prospective. SETTING: Children's Health Care-Minneapolis hematology/oncology inpatient ward and outpatient clinic. PATIENTS: Ten immune-compromised children (mean +/- SD age 7.4 +/- 4.0 yrs, weight 31.6 +/- 25.9 kg) with leukemia or other hematologic disease. INTERVENTIONS: Serum was sampled before and after a single 6-mg/kg intravenous dose and after seven oral 3-mg/kg doses of fluconazole. MEASUREMENTS AND MAIN RESULTS: Mean (SD) pharmacokinetics were distribution half-life 1.67 (1.25) hours, elimination half-life 15.62 (3.21) hours, total body clearance 0.63 (0.19) ml/min/kg, volume of distribution for the central compartment 0.56 (0.10) L/kg, volume of distribution at steady state 0.77 (0.12) L/kg, absorption half-life 0.41 (0.26) hour, and oral bioavailability 0.92 (0.09). Volume of distribution for the central compartment was highly correlated with body surface area (r2 = 0.891) and weight (r2 = 0.949). Volume of distribution at steady state correlated with body surface area (r2 = 0.986), and total body clearance correlated with body surface area (r2 = 0.867). CONCLUSIONS: Fluconazole elimination was well described using a two-compartment model. Oral absorption was rapid and nearly complete. Children have a larger volume of distribution for the central compartment and faster elimination rate than adults. Body surface area and weight are important factors in determining pharmacokinetics in these patients.

Absorption↗