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Biomedical subjects

G R Buchanan

Publications and source records attributed to G R Buchanan.

At least 91 records · Page 5Linked to original sources
PubMed1994

Splenic rupture in hemophilia.

PURPOSE: Little information is available regarding splenic injury in patients with hemophilia. We describe here the management of splenic rupture in five of our patients with hemophilia and summarize the literature describing this complication. PATIENTS AND METHODS: Two human immunodeficiency virus-seropositive patients were managed medically and did not require splenectomy. A third patient had a high titer inhibitor to both porcine and human factor VIII and required emergency splenectomy. Two boys had not been previously diagnosed with hemophilia until they underwent splenectomy after abdominal trauma. RESULTS: All five patients survived. CONCLUSIONS: These cases demonstrate that nonsurgical management of splenic injury in patients with hemophilia can be performed safely and that splenectomy can be successfully performed despite a high titer of factor VIII inhibitor.

Adolescent↗
PubMed1994

Aerosolized pentamidine for the prevention of Pneumocystis carinii pneumonia in children with cancer intolerant or allergic to trimethoprim/sulfamethoxazole.

PURPOSE: Trimethoprim/sulfamethoxazole (TMP/SMX) is the drug of choice for Pneumocystis carinii pneumonia (PCP) prophylaxis in immunocompromised patients. In children with malignancy, TMP/SMX is well tolerated, but adverse reactions that necessitate discontinuation can occur. We evaluated the safety and efficacy of aerosolized pentamidine (AP) as an alternative prophylaxis modality in children with malignancy who are intolerant of or allergic to TMP/SMX. PATIENTS AND METHODS: AP (200 mg/m2 every 4 weeks) was administered to 60 children with malignancy receiving chemotherapy who had experienced severe adverse reactions to TMP/SMX. Seven hundred twenty doses of AP have been administered during a 3 1/2-year period (21,600 patient-days), with 30 patients treated for > or = 12 months (range, 12 to 25). RESULTS: Adverse reactions occurred during 79 (10%) of the 720 treatments and included bronchospasm in 23, cough in 40, vomiting in 10, and nausea in six. Only two patients had severe bronchospasm. AP was discontinued due to toxicity in three patients (5%). None of the patients (upper 95% confidence limit, 0.049) have developed PCP. CONCLUSION: AP appears to be well tolerated and effective in the prevention of PCP in children with malignancy.

Adolescent↗
PubMed1994

Phase II investigational window using carboplatin, iproplatin, ifosfamide, and epirubicin in children with untreated disseminated neuroblastoma: a Pediatric Oncology Group study.

PURPOSE: Children less than 1 year of age with metastatic neuroblastoma NB are at high risk of death. The need to identify new and effective chemotherapy agents is clear. A study was conducted by the Pediatric Oncology Group (POG) to determine the efficacy and safety of administering two courses of a single phase II agent before conventional treatment as a means to evaluate new agents in this setting. PATIENTS AND METHODS: One hundred seventy-three eligible patients more than 1 year of age with disseminated neuroblastoma received two courses of one of the following: ifosfamide (IFOS) 2 g/m2/d for 4 days intravenously (IV) plus mesna; carboplatin (CARB) 560 mg/m2 i.v. over 1 hour; iproplatin (CHIP) 325 mg/m2 IV over 2 hours; or epirubicin (EPIR) 90 mg/m2 i.v. push. Following evaluation for response and toxicity, eligible patients were randomized to receive either cisplatin 90 mg/m2 i.v. on day 1, etoposide 200 mg/m2 i.v. on day 3, cyclophosphamide 150 mg/m2/d orally on days 7 to 13, doxorubicin 35 mg/m2 i.v. on day 14 (CECA), or cisplatin 40 mg/m2 IV on days 1 to 5 and etoposide 200 mg/m2 i.v. on days 2 to 4 alternating at 3-week intervals with cyclophosphamide 150 mg/m2/d orally on days 1 to 7 and doxorubicin 35 mg/m2 IV on day 8 (HDP/VP/CA). An additional 86 patients were randomized to receive either CECA or HDP/VP/CA without initial phase II therapy. RESULTS: After phase II therapy, only 20% of patients experienced grade 3/4 hematopoietic toxicity. No toxic deaths occurred. Objective response rates (partial responses [PRs] plus minor responses [MRs]) following IFOS, CARB, CHIP, and EPIR were 70%, 77%, 67%, and 26%, respectively. Following phase III treatment, there was no statistically significant difference in rates of complete response (CR)/PR or progressive disease (PD), or in time to PD of patients who participated in the phase II window versus those who received only CECA or HDP/VP/CA. CONCLUSION: IFOS, CARB, and CHIP are efficacious in neuroblastoma, are well tolerated, and should be incorporated into primary treatment regimens. Combination regimens using these agents may be possible, since most repeat courses were given within 2 weeks. Administering phase II therapy to untreated patients with high-risk tumors provides a unique and sensitive method to assess new agents without compromising patient outcome.

Adolescent↗
PubMed1993

Ifosfamide with mesna uroprotection and etoposide in recurrent, refractory acute leukemia in childhood. A Pediatric Oncology Group Study.

BACKGROUND: Ifosfamide has previously been shown to be active as a single agent and in combination with doxorubicin, etoposide, and teniposide in pediatric solid tumors and adult acute leukemia. The authors performed a dose-escalation trial of ifosfamide with a fixed dosage of etoposide, with mesna uroprotection, in children with multiply recurrent acute leukemia. METHODS: Chemotherapy was administered daily for 5 days. Etoposide 100 mg/m2 was followed by ifosfamide at an initial dosage of 1.6 g/m2. The ifosfamide was escalated in 20% increments to the maximum tolerated dosage in cohorts of three patients. Mesna 400 mg/m2 was given immediately before the ifosfamide and then at 3 and 6 hours after ifosfamide in the initial patients. Subsequent patients were treated with mesna 400 mg/m2 just before ifosfamide, and then every 2 hours to a total dosage equal to the ifosfamide dosage. RESULTS: Forty-four heavily pretreated patients were entered on study. Forty were evaluable for toxicity and 36 for response as well. The maximum tolerated dosage of ifosfamide was 4.0 g/m2/d for 5 days (20 g/m2/course). Overall, 10 patients achieved complete remission, and 3 achieved partial remission. Remissions were brief, although four patients went on to bone marrow transplant while in remission. One patient is still alive. CONCLUSIONS: The combination of etoposide and ifosfamide with mesna uroprotection showed promising activity in children with multiply recurrent acute leukemia.

Acute Disease↗
PubMed1993

Clinical features and outcome of T-cell acute lymphoblastic leukemia in childhood with respect to alterations at the TAL1 locus: a Pediatric Oncology Group study.

Alteration of the TAL1 locus is the most common nonrandom genetic defect in childhood T-cell acute lymphoblastic leukemia (T-ALL). To determine if rearrangements of the TAL1 proto-oncogene confer a distinct leukemic phenotype, we studied leukemic peripheral blood or bone marrow samples from 182 children with newly diagnosed T-ALL enrolled on Pediatric Oncology Group treatment protocols. Forty-eight (26%) of the samples had a local rearrangement of the TAL1 locus. Demographic and clinical features were compared for patient subgroups with and without TAL1 rearrangements. The only clinical correlates that were significantly associated with TAL1 gene rearrangements were higher white blood cell count (P = .017) and higher hemoglobin (P = .007) at diagnosis. Immunophenotypically, samples with altered TAL1 were more likely to be CD2+ (P = .001) and lack CD10 (cALLa) expression (P = .007) than those without the rearrangement. There was a trend toward improved event-free survival (EFS) in patients with TAL1 rearrangements (4-year EFS was 44% +/- 7% for patients without the rearrangements v 59% +/- 11% for those with rearrangements), but the difference was not significant (P = .34). The role of TAL1 in leukemogenesis has yet to be clearly defined, and the prognostic significance of TAL1 gene rearrangements in T-ALL deserves further study.

Adolescent↗
PubMed1993

Treatment of late bone marrow relapse in children with acute lymphoblastic leukemia: a Pediatric Oncology Group study.

Children with acute lymphoblastic leukemia (ALL) who have completed 2.5 to 3 years of initial chemotherapy have an off-therapy relapse rate of approximately 20%. In an attempt to improve the survival of children with a late bone marrow (BM) relapse (ie, occurring greater than 6 months after cessation of primary therapy), the Pediatric Oncology Group designed a randomized study to compare the efficacy of doxorubicin/prednisone and cytarabine/teniposide in a multidrug retreatment chemotherapy program. Treatment consisted of remission reinduction with vincristine, prednisone, and doxorubicin, central nervous system prophylaxis with triple intrathecal chemotherapy, and continuation therapy (for 132 weeks) with alternating cycles of oral 6-mercaptopurine/methotrexate and intravenous vincristine/cyclophosphamide. Patients received intermittent courses of either prednisone/doxorubicin (regimen 1) or teniposide/cytarabine (regimen 2) during continuation therapy and a late intensification phase with either vincristine, prednisone, and doxorubicin (regimen 1) or teniposide and cytarabine (regimen 2). One hundred two of 105 evaluable patients (97%) achieved a second complete remission. Twenty-eight of 50 patients on regimen 1 have failed compared with 28 or 52 patients on regimen 2 (log-rank analysis, P = .68), indicating that this trial was inconclusive as to which treatment regimen was superior. The overall 4-year event-free survival for children with a late BM relapse was 37% +/- 6%. Age less than 10 years at initial diagnosis (P < or = .001), white blood cell count less than 5,000/microL at relapse (P = .036) and duration of first remission greater than 54 months (P = .039) were independently associated with a more favorable outcome. While the randomized trial was inconclusive, prolonged second complete remissions were secured in more than one-third of children with a late BM relapse of ALL. The prognostic factors identified may help select children with a late BM relapse who can be successfully retreated with chemotherapy alone.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1993

Elective surgery in children with sickle cell disease without preoperative blood transfusion.

It is generally recommended that patients with sickle cell disease receive red blood cell (RBC) transfusions before undergoing general anesthesia and surgery. Since RBC transfusions are costly, inconvenient, and may cause serious complications, it might be useful to identify groups of patients for whom they are not absolutely necessary. We report our experience with 54 pediatric patients undergoing 66 elective surgical procedures without preoperative transfusion preparation. All patients were felt to be clinically and hematologically stable in the immediate preoperative period. For the majority of procedures (57/66, 86%) no transfusions were administered at any time during the perioperative course. There were no intraoperative complications or postoperative deaths. Overall, some type of postoperative complication was encountered after 17 procedures (26%). Complications were usually minor and were more likely to occur after procedures involving thoracotomy or laparotomy (10/20, 50%) and tonsillectomy/adenoidectomy (T&A) (5/9, 56%) than other procedures (2/37, 5%; P < .001). Pulmonary complications were especially more prevalent in the group undergoing thoracotomy, laparatomy, or T&A (9/29 v 0/37 for all other procedures, P < .001). We conclude that preoperative transfusions might be avoided in children with sickle cell disease who undergo most minor surgical procedures on an elective basis. Patients undergoing thoracotomy, laparotomy, or T&A are at a relatively higher risk of developing postoperative complications and would comprise ideal groups for evaluation of preoperative transfusion regimens in prospective carefully controlled, randomized studies.

Adolescent↗
PubMed1993

Hypoprothrombinemia and severe hemorrhage associated with a lupus anticoagulant.

We recently encountered a previously healthy 3-year-old girl who had severe bleeding resulting from a severe deficiency of prothrombin. A lupus anticoagulant was identified by several different methods. The patient was successfully treated with glucocorticoids. This rare complication of a lupus anticoagulant should be considered in the differential diagnosis of a previously well child who suddenly has hemorrhage.

Child, Preschool↗
PubMed1993

Secondary acute myeloid leukemia in children with acute lymphoblastic leukemia treated with etoposide.

PURPOSE: To describe the occurrence of secondary acute myeloid leukemia (AML) in children with acute lymphoblastic leukemia (ALL) treated with etoposide (VP-16). PATIENTS AND METHODS: Two hundred five consecutive children with early B-lineage ALL were treated according to the Dallas/Fort Worth (DFW) protocol between January 1986 and July 1, 1991. Therapy included a four-drug induction followed by consolidation and continuation phases of nightly oral mercaptopurine (6-MP) and repetitive courses of divided-dose oral methotrexate (dMTX) and asparaginase (L-asp). Three doses of VP-16 and cytarabine (Ara-C) were given during consolidation and later, during continuation, two doses were given 3 to 4 days apart, every 9 weeks. Intrathecal (IT) chemotherapy was given throughout the treatment period. RESULTS: Two hundred three of the 205 patients entered remission. Only eight of these 203 children have had a bone marrow relapse (ALL). However, 10 other children have developed secondary AML 23 to 68 months following the diagnosis of ALL. Overall event-free survival (EFS) at 4 years is 79.3% +/- 5.1%, with a risk of secondary AML at 4 years of 5.9% +/- 3.2%. CONCLUSION: This experience provides strong evidence for a link between epipodophyllotoxin therapy and secondary AML since none of these children received alkylating agent therapy or irradiation. This serious complication raises concern as to the appropriate use of epipodophyllotoxins in the treatment of childhood ALL.

Acute Disease↗
PubMed1993

Approach to treatment of the febrile cancer patient with low-risk neutropenia.

All cancer patients who develop fever during a period of neutropenia are not at high risk of developing serious infection. Following hospitalization for empiric broad spectrum antibiotic therapy, certain low-risk patients can be identified and safely be discharged "early", prior to recovery of the absolute neutrophil count to 500 cells per mm3. The medical, psychological, and financial benefits of early hospital discharge are immense. Careful examination for serial increases in components of the peripheral blood count herald marrow recovery and help identify the low-risk patient. It may also be possible to identify "low-risk" neutropenic patients upon development of fever in order to explore alternative management strategies (for example, outpatient oral or intravenous antibiotics) rather than routine hospitalization.

Bone Marrow↗
PubMed1992

Unexpected acute neurologic toxicity in the treatment of children with acute lymphoblastic leukemia.

BACKGROUND: Our current protocol for treatment of childhood acute lymphoblastic leukemia (ALL) was designed to assess the efficacy of methotrexate (MTX) plus L-asparaginase and of etopisode (VP-16) plus cytarabine (ARA-C) during intensive consolidation and continuation therapies and to determine the feasibility of intensifying MTX therapy by the use of divided oral doses of MTX. The protocol was associated with unexpected acute neurotoxicity. There are few reports of such toxic effects during therapy for ALL. PURPOSE: This report describes these toxic effects and outlines our successful approach to the problem. METHODS: The standard four-drug induction regimen consisted of vincristine, L-asparaginase, daunorubicin, and prednisone. In consolidation therapy, oral MTX was given in divided doses (dMTX) of 25 mg/m2 every 6 hours four times daily in four weekly courses concomitant with weekly triple intrathecal therapy--MTX, ARA-C, and hydrocortisone--plus one dose of leucovorin 24 hours after triple intrathecal therapy. Consolidation treatment ended with three daily doses of intravenous VP-16 and ARA-C. The first 16 months of continuation therapy included 6-week cycles of dMTX and L-asparaginase, both given every other week for 5 weeks, with 6-mercaptopurine nightly, and then two doses of VP-16 plus ARA-C and one dose of triple intrathecal therapy. RESULTS: Twenty-five of the 138 patients evaluated had acute neurotoxicity. Ten of the first 72 experienced a seizure or episode of transient neurological deficit 9-11 days following the administration of intravenous ARA-C, VP-16, and triple intrathecal therapy. Despite discontinuation of intrathecal ARA-C, which eliminated simultaneous intravenous and intrathecal treatment with ARA-C, acute neurotoxicity was observed in six previously unaffected patients and six of 42 patients treated after the elimination of intrathecal ARA-C. Therefore, as a second amendment, oral leucovorin was given 24 and 36 hours after dMTX and intrathecal MTX in continuation therapy. No acute neurotoxicity has been seen in 24 patients subsequently entered in the study. CONCLUSION: These findings suggest that folate replacement due to administration of leucovorin modulated MTX toxicity and/or modified an interaction among VP-16, ARA-C, intrathecal therapy, and the central nervous system.

Adolescent↗
PubMed1992

A fatal case of acute splenic sequestration in a 53-year-old woman with sickle-hemoglobin C disease.

Acute splenic sequestration crisis (ASSC) is a common complication in infants and young children with homozygous sickle cell disease, but it is infrequent in patients with sickle-hemoglobin C (SC) disease. When it does occur in such patients, it is often associated with exposure to high altitude, either by air travel or mountainous environment. Since 1970, only 15 cases of ASSC have been reported in patients with SC disease who were not exposed to a high altitude. Nine of these were children and adolescents aged 11 to 18 years, while six were adults aged 21 to 44 years. A review of these cases shows only two fatalities from ASSC: a 12-year-old West Indian girl living in England and a 13-year-old black girl in the United States. In this report, we describe the sudden death from ASSC of a 53-year-old black woman with SC disease at low altitude. To our knowledge, death from ASSC has not been previously reported in an adult patient with SC disease.

Acute Disease↗