A pharmacogenetic study of ADRB2 polymorphisms and indacaterol response in COPD patients.

Genetic variation in the ADRB2 gene has been hypothesized to have a role in differential response to beta-agonist (BA) therapy in asthma. However, study results have been inconsistent and the issue remains controversial. Furthermore, the impact of ADRB2 genetic variation on BA response in chronic obstructive pulmonary disease (COPD) patients has not been thoroughly studied. We carried out a large pharmacogenetic analysis testing for an association between common ADRB2 polymorphisms and indacaterol response in COPD patients. A total of 648 indacaterol-treated patients enrolled in two large randomized phase III studies were genotyped for the most commonly studied polymorphisms in the ADRB2 gene: Gly16Arg, Gln27Glu, Thr164Ile, and a variant in the 5' untranslated region (rs1042711). Our analysis showed little evidence for the association between these ADRB2 variants and indacaterol response, suggesting that ADRB2 genetic variation is unlikely to have a major role in differential response to indacaterol treatment in COPD patients.

Molecular alterations of the IDH1 gene in AML: a Children's Oncology Group and Southwest Oncology Group study.

Recent whole-genome sequencing efforts led to the identification of IDH1(R132) mutations in acute myeloid leukemia (AML) patients. We studied the prevalence and clinical implications of IDH1 genomic alterations in pediatric and adult AML. Diagnostic DNA from 531 AML patients treated on Children's Oncology Group trial COG-AAML03P1 (N=257), and Southwest Oncology Group trials SWOG-9031, SWOG-9333 and SWOG-9500 (N=274), were tested for IDH1 mutations. Codon R132 mutations were absent in the pediatric cohort, but were found in 12 of 274 adult patients (4.4%, 95% CI 2.3-7.5). IDH1(R132) mutations occurred most commonly in patients with normal karyotype, and those with FLT3/ITD and NPMc mutations. Patients with IDH1(R132) mutations trended toward higher median diagnostic white blood cell counts (59.2 x 10(9) vs 29.1 x 10(9) per liter, P=0.19) than those without mutations, but the two groups did not differ significantly in age, bone marrow blast percentage, overall survival or relapse-free survival. Eleven patients (2.1%) harbored a novel V71I sequence alteration, which was found to be a germ-line polymorphism. IDH1 mutations were not detected in pediatric AML, and are uncommon in adult AML.

Paclitaxel for the treatment of progressive or recurrent childhood brain tumors: a pediatric oncology phase II study.

PURPOSE: To assess the efficacy and define the toxicity of paclitaxel given at a dosage of 350 mg/m2 every 3 weeks as a 24-hour continuous infusion to children with recurrent or progressive primary brain tumors. PATIENTS AND METHODS: Seventy-three eligible patients, ages 4 months to 19 years, with progressive or recurrent primary brain tumors were treated according to a Pediatric Oncology Group (POG) phase II protocol with paclitaxel (POG 9330). Tumor histologic strata included: astrocytoma (n = 4), malignant glioma (n = 13), medulloblastoma (n = 16), brain stem glioma (n = 15), ependymoma (n = 13), and miscellaneous histologies (n = 12). All patients had previous histologic confirmation of a primary intracranial or spinal cord tumor with magnetic resonance imaging or computed tomography documentation of unequivocally measurable progressive or recurrent disease. All patients had received previous therapy including surgery, radiation therapy, and/or chemotherapy, but no patient had been previously treated on more than one phase II trial. Paclitaxel was administered as a 24-hour intravenous infusion at a dosage of 350 mg/m2 every 3 weeks. Neurologic and neuroradiologic reevaluations were performed after every second course. Patients were allowed to continue therapy for a total of 18 cycles in the absence of progressive disease or unacceptable toxicity. RESULTS: Seventy-five patients were enrolled onto the POG 9330 protocol; two ineligible patients were removed from the study before receiving any therapy. Of the 73 eligible patients, 72 were evaluable for toxicity and 70 were either fully or partially evaluable for disease response. There was one complete response and three partial responses (5.7%). Twenty patients had stable disease for more than 2 months. Toxicities included mild nausea, central nervous system toxicity, myelosuppression, and febrile neutropenia, including one septic death. One grade 2 and two grade 3 allergic reactions occurred. No cardiac toxicities or arthralgias were reported. CONCLUSION: Paclitaxel is well tolerated in children with recurrent or progressive brain tumors at this dosage and schedule and may result in short-term disease stabilization in this patient population. The lack of a significant number of patients with measurable disease regression, however, precludes it from being identified as an active agent when administered as a single agent by 24-hour continuous infusion.

Experience with 2-chlorodeoxyadenosine in previously untreated children with newly diagnosed acute myeloid leukemia and myelodysplastic diseases.

PURPOSE: To develop more effective chemotherapy regimens for childhood acute myelogenous leukemia (AML). PATIENTS AND METHODS: Between June 1991 and December 1996, we administered the nucleoside analog 2-chlorodeoxyadenosine (2-CDA) to 73 children with primary AML and 20 children with secondary AML or myelodysplastic syndrome (MDS). Patients received one or two 5-day courses of 2-CDA (8.9 mg/m(2)/d) given by continuous infusion. All patients then received one to three courses of daunomycin, cytarabine, and etoposide (DAV) remission induction therapy. RESULTS: Seventy-two patients with primary AML were assessable for response. Their rate of complete remission (CR) was 24% after one course of 2-CDA, 40% after two courses of 2-CDA, and 78% after DAV therapy. Of the 57 patients who entered CR, 11 subsequently underwent allogeneic bone marrow transplantation (BMT), and 40 underwent autologous BMT. Twenty-nine patients remain in continuous CR after BMT. Two patients remain in CR after chemotherapy only. The 5-year event-free survival (EFS) estimate was 40% (SE = 0.080%). Patients with French-American-British (FAB) M5 AML had a higher rate of CR after treatment with 2-CDA (45% after one course and 70.6% after two courses) than did others (P =.002). In contrast, no patient with FAB M7 AML (n = 10) entered CR after treatment with 2-CDA. Similarly, no patient with primary MDS (n = 6) responded to 2-CDA. Seven patients with secondary AML or MDS (n = 14) had a partial response to one course of 2-CDA. CONCLUSION: This agent was well tolerated, and its toxicity was acceptable. Future trials should examine the effectiveness of 2-CDA given in combination with other agents effective against AML.

Application of pressure steps to mechanosensitive channels in membrane patches: a simple, economical, and fast system.

Mechanosensitive channels (MSCs) have been described in a wide variety of cells, but the molecular mechanisms that couple membrane tension or deformation to channel activity (i.e., mechanotransduction) are not understood. The ability to measure the dynamics of the temporal relationship between the pressure stimulus and the channel response is a key tool for gaining insight into mechanotransduction. Several laboratories have designed pressure clamps, but these instruments are complex, costly, and not commercially available. This paper describes a simple and inexpensive system for applying fast pressure steps to a membrane patch. This system is easy to build and achieves submillisecond 20% to 80% step response times on par with the fastest pressure clamp described. Application to a stretch-activated non-selective cation channel in the kidney is used to demonstrate the system.

Improved outcome for children with acute lymphoblastic leukemia: results of Dana-Farber Consortium Protocol 91-01.

The Dana-Farber Cancer Institute (DFCI) acute lymphoblastic leukemia (ALL) Consortium Protocol 91-01 was designed to improve the outcome of children with newly diagnosed ALL while minimizing toxicity. Compared with prior protocols, post-remission therapy was intensified by substituting dexamethasone for prednisone and prolonging the asparaginase intensification from 20 to 30 weeks. Between 1991 and 1995, 377 patients (age, 0-18 years) were enrolled; 137 patients were considered standard risk (SR), and 240 patients were high risk (HR). Following a 5.0-year median follow-up, the estimated 5-year event-free survival (EFS) +/- SE for all patients was 83% +/- 2%, which is superior to prior DFCI ALL Consortium protocols conducted between 1981 and 1991 (P =.03). There was no significant difference in 5-year EFS based upon risk group (87% +/- 3% for SR and 81% +/- 3% for HR, P =.24). Age at diagnosis was a statistically significant prognostic factor (P =.03), with inferior outcomes observed in infants and children 9 years or older. Patients who tolerated 25 or fewer weeks of asparaginase had a significantly worse outcome than those who received at least 26 weeks of asparaginase (P <.01, both univariate and multivariate). Older children (at least 9 years of age) were significantly more likely to have tolerated 25 or fewer weeks of asparaginase (P <.01). Treatment on Protocol 91-01 significantly improved the outcome of children with ALL, perhaps due to the prolonged asparaginase intensification and/or the use of dexamethasone. The inferior outcome of older children may be due, in part, to increased intolerance of intensive therapy.

Cognitive sequelae in children treated for acute lymphoblastic leukemia with dexamethasone or prednisone.

PURPOSE: The cognitive sequelae of treatment for childhood acute lymphoblastic leukemia (ALL) were compared in a group of patients who received dexamethasone during the intensification and maintenance phases of therapy with those in a historical control group for whom antileukemia therapy was similar, except that the corticosteroid component of therapy was prednisone. METHODS: Patients treated for ALL on Dana-Farber Cancer Institute protocols 87-01 (n = 44) and 91-01 (n = 23) were evaluated by standard cognitive and achievement tests. Corticosteroid therapy was delivered in 5-day pulses given every 3 weeks during intensification and continuation phases of therapy for a total of 2 years. RESULTS: Children treated on protocol 87-01 received prednisone at a dose of 40 mg/m2/d (standard risk, SR) or 120 mg/ m2/d (high risk, HR); those treated on protocol 91-01 received dexamethasone at a dose of 6 mg/m2 per day (SR) or 18 mg/m2 per day (HR). Children treated on protocol 91-01 performed less well on cognitive testing. Subsample analysis indicated that cranial radiation therapy and methotrexate dose did not account for differences in cognitive outcomes. CONCLUSIONS: The findings of this preliminary study are consistent with the hypothesis that dexamethasone therapy can increase risk for neurocognitive late effects in children treated for ALL and indicate that further investigation of this question is warranted.

Substituting dexamethasone for prednisone complicates remission induction in children with acute lymphoblastic leukemia.

BACKGROUND: The authors report the occurrence of fatal or near-fatal sepsis in 16 of 38 children with newly diagnosed acute lymphoblastic leukemia (ALL) treated with a new induction regimen that differed from its predecessor by the substitution of dexamethasone for prednisone. METHODS: The frequency of septic deaths among 38 children who received multiagent remission induction therapy, including dexamethasone (6 mg/m(2)) daily for 28 days (pilot protocol 91-01P), was compared with the frequency of septic deaths among children previously treated (protocol 87-01) and subsequently treated (protocol 91-01) in consecutive Dana-Farber Cancer Institute (DFCI) ALL trials with induction therapy that included 21 and 28 days of prednisone (40 mg/m(2)), respectively. Except for dexamethasone in protocol 91-01P, the remission induction agents used were identical in substance to those used in protocol 87-01. Protocol 91-01, the successor 91-01P, was also similar, with the exception of the deletion of a single dose of L-asparaginase. RESULTS: Sixteen of the 38 children (42%) treated on the DFCI 91-01P had documented gram positive or gram negative sepsis (17 episodes) during remission induction, including 4 toxic deaths (11%). In contrast, there were 4 induction deaths among 369 children (1%) treated on protocol 87-01 (P = 0.0035) and 1 induction death among 377 children (<1%) treated on protocol 91-01 (P = 0.0003). CONCLUSIONS: Substitution of dexamethasone for prednisone or methylprednisolone in an otherwise intensive conventional induction regimen for previously untreated children with ALL resulted in an alarmingly high incidence of septic episodes and toxic deaths. Awareness of this complication, considering that the substitution has no apparent benefit in the efficacy of remission induction, argues against its routine use in intensive induction regimens for children with ALL.

Pulmonary leukostasis mimicking pulmonary embolism.

We report a case of a 32-year-old woman who presented with shortness of breath and pleuritic chest pain, and mismatched perfusion defects on a ventilation-perfusion scan suspicious for pulmonary embolism. However, subsequent data revealed the diagnosis of acute myelogenous leukemia with hyperleukocytosis and associated pulmonary leukostasis. Unfortunately, the patient died despite urgent leukopheresis. Autopsy examination revealed extensive infiltration of leukemic cells in all major organs with no evidence of pulmonary embolism. This case highlights the clinical, radiographic and histologic features of pulmonary leukostasis, and reminds the clinician that not all ventilation-perfusion mismatching is due to thromboembolic disease.

Results of Dana-Farber Cancer Institute Consortium protocols for children with newly diagnosed acute lymphoblastic leukemia (1981-1995).

The Dana-Farber Cancer Institute (DFCI) ALL consortium has been conducting clinical trials in childhood acute lymphoblastic leukemia (ALL) since 1981. The treatment backbone has included intensive, multi-agent remission induction, early intensification with weekly, high-dose asparaginase, cranial radiation for the majority of patients, frequent vincristine/ corticosteroid pulses during post-remission therapy, and for high-risk patients, doxorubicin during intensification. Between 1981 and 1995, 1,255 children with newly diagnosed ALL were evaluated on four consecutive protocols: 81-01 (1981-1985), 85-01 (1985-1987), 87-01 (1987-1991) and 91-01 (1991-1995). The 5-year event-free survival (EFS) rates (+/- standard error) for all patients by protocol were as follows: 74 +/- 3% (81-01), 78 +/- 3% (85-01), 77 +/- 2% (87-01) and 83 +/- 2% (91-01). The 5-year EFS rates ranged from 78 to 85% for patients with B-progenitor phenotype retrospectively classified as NCI standard-risk, 63-82% for NCI high-risk B-progenitor patients, and 70-79% for patients with T cell phenotype. Results of randomized studies revealed that neither high-dose methotrexate during induction (protocol 87-01) nor high-dose 6-mercaptopurine during intensification (protocol 91-01) were associated with improvement in EFS compared with standard doses. Current studies continue to focus on improving efficacy while minimizing acute and late toxicities.

A Phase I trial of bryostatin-1 in children with refractory solid tumors: a Pediatric Oncology Group study.

Bryostatin-1, a macrocyclic lactone, appears to elicit a wide range of biological responses including modulation of protein kinase C (PKC). PKC, one of the major elements in the signal transduction pathway, is involved in the regulation of cell growth, differentiation, gene expression, and tumor promotion. Because of the potential for a unique mechanism of interaction with tumorgenesis, a Phase I trial of bryostatin-1 was performed in children with solid tumors to: (a) establish the dose-limiting toxicity (DLT) and maximum-tolerated dose (MTD); (b) establish the pharmacokinetic profile in children; and (c) document any evidence of antitumor activity. A 1-h infusion of bryostatin-1 in a PET formulation (60% polyethylene glycol 400, 30% ethanol, and 10% Tween 80) was administered weekly for 3 weeks to 22 children (age range, 2-21 years) with malignant solid tumors refractory to conventional therapy. Doses ranged from 20 to 57 microg/m2/ dose. Pharmacokinetics were performed in at least three patients per dose level. The first course was used to determine the DLT and MTD. Twenty-two patients on five dose levels were evaluable for toxicities. At the 57 microg/m2/dose level dose-limiting myalgia (grade 3) was observed in three patients; two of those patients also experienced photophobia or eye pain, and one experienced headache. Symptoms occurred in all patients within 24-72 h after the second dose of bryostatin-1 with resolution within 1 week of onset. Other observed toxicities (grades 1 and 2) included elevation in liver transaminases, thrombocytopenia, fever, and flu-like symptoms. The bryostatin-1 infusion was typically well tolerated. Although stable disease was noted in several patients, no complete or partial responses were observed. The recommended Phase II dose of bryostatin-1 administered as a 1-h infusion weekly for 3 of every 4 weeks to children with solid tumors is 44 microg/m2/dose. Myalgia, photophobia, or eye pain, as well as headache, were found to be dose limiting.

Severing of F-actin by the amino-terminal half of gelsolin suggests internal cooperativity in gelsolin.

Gelsolin is a Ca2+-regulated actin-binding protein that can sever, cap, and nucleate growth from the pointed ends of actin filaments. In this study we have measured the binding of the amino-terminal half of gelsolin, G1-3, to pyrene-labeled F-actin as a function of Ca2+ concentration. The rate of binding is shown to be dependent on micromolar concentrations of Ca2+. Independent experiments demonstrate that conformational changes in G1-3 are induced by micromolar concentrations of Ca2+. Titrations of pyrene-F-actin with G1-3 and gelsolin show that the quenching of pyrene fluorescence is identical in extent and stoichiometry for both G1-3 and gelsolin. In contrast, severing of F-actin by G1-3 is found to be much less efficient than is severing by gelsolin. In experiments in which F-actin severing is quantitatively measured, the filament number is found to be proportional to the 1.35 power of the G1-3 concentration. This deviation from linearity may be explained by cooperativity; the binding of two G1-3 molecules in close proximity may lead to cooperative severing of the polymer, thus increasing the severing efficiency. This model is supported by experiments that show that the efficiency of G1-3 severing of F-actin increases with increasing G1-3:F-actin ratios. Extrapolating from these results, we conclude that G4-6, the carboxyl-terminal half of gelsolin, has an active role in the severing of F-actin by intact gelsolin. Whereas F-actin severing by G1-3 is enhanced by cooperative binding of two separate G1-3 molecules, cooperativity is inherent to intact gelsolin because the cooperative partners are covalently linked.

Cell cycle inhibition in human BE-13 T cell leukemia cells by haptoglobin-related (HPR) antisense cDNA.

We have recently cloned and sequenced a human haptoglobin-related cDNA. Hpr expression was found in various tumor cell lines. To determine whether the haptoglobin related protein (hpr) affects the growth of an established T-cell leukemia cell line, an Hpr antisense expression vector that specifically reduces hpr production was constructed. The vector was transfected into BE-13 cells, an established T-cell leukemia cell line in which Hpr is expressed. Three stable clones were isolated in which hpr protein expression was reduced. These established cell lines proliferated more slowly than vector transfected cells in proportion to Hpr antisense mRNA expression and the reduction in hpr protein production. Following a BrdU pulse, flow cytometric analysis was performed to estimate the fraction of cells in S phase. Hpr antisense transfected cells contained less cells in S phase compared to vector transfected cells. Also in soft agar, cells expressing the antisense cDNA insert, formed on average at least 7-fold fewer colonies than cells transfected with the vector alone. The data suggest that Hpr inhibitors might be of therapeutic value for T-cell leukemia.

Efficiency of P-glycoprotein-mediated exclusion of rhodamine dyes from multidrug-resistant cells is determined by their passive transmembrane movement rate.

The aim of the present study was to examine the relationship between the rate of the passive transmembrane movement of multidrug resistance (MDR)-type substrates and the ability of P-glycoprotein to extrude them from MDR cells. For this purpose, seven rhodamine dyes were examined for their P-glycoprotein-mediated exclusion from MDR cells, their localization in wild-type drug-sensitive cells, their capacity to stimulate the ATPase activity of P-glycoprotein reconstituted in proteoliposomes, and their transmembrane movement rate in artificial liposomes. All these rhodamine dyes were accumulated in wild-type drug-sensitive cells and were localized mainly in the mitochondria. All the dyes tested were substrates of reconstituted P-glycoprotein and cellular P-glycoprotein and were excluded to a variable degree from MDR cells. The transmembrane movement rate proved the major factor determining the efficacy of the P-glycoprotein-mediated exclusion of rhodamine dyes from MDR cells. Thus, rhodamine B, the poorest cellular P-glycoprotein substrate, exhibited a high affinity toward reconstituted P-glycoprotein, but was the fastest membrane-traversing dye. In contrast, tetramethylrosamine, the best cellular MDR probe, exhibited high affinity toward reconstituted P-glycoprotein and slow transmembrane movement rate. Therefore, an anticancer drug with a fast transmembrane movement rate is expected to overcome the MDR phenomenon. Furthermore, the widely used MDR marker, rhodamine 123, was a poor cellular MDR substrate compared with other rhodamine dyes, especially tetramethylrosamine, which was a superior cellular MDR substrate for functional dye-exclusion studies.

A pilot study of continuous infusion Ara-C in combination with rhG-CSF in relapsed childhood acute myeloid leukemia.

Relapse in acute myeloid leukemia (AML) following intensive chemotherapy bears a bad prognosis. We treated 18 children with relapsed AML on two separate protocols that included continuous infusion (CI) of cytosine arabinoside (ara-C) (total dose 4gr-6gr/m2) over 96-120 hours. In an attempt to increase the fraction of blasts in S-phase and render them more sensitive to cell-cycle specific agents such as ara-C, 10 patients received 5mcg/kg rhG-CSF twice daily beginning 48 hours before and continuing through the duration of the CI ara-C (POG #9192 study). The percentage of cells is S phase before and after G-CSF administration was determined. In a second group of patients (n = 8) who received ara-C alone, endogenous concentrations of G-CSF and serial blood counts were measured (St Jude's R4 study). The rationale of the St Jude's R4 was to optimize the schedule of the second course of ara-C at a time when the patient's endogenous G-CSF concentration was increased and thus maximize the percent of cells captured in S phase. Four out of 8 patients receiving CI ara-C alone and 4 out of 10 patients receiving CI ara-C with rhG-CSF achieved a complete remission (CR) after 1 cycle of therapy. Four patients in CR underwent marrow transplantation (2 allogeneic and 2 autologous). Cell cycle analysis of blast cells cultured in vitro with or without G-CSF showed a two fold increase in the percentage of cells in S phase (P = 0.03) whereas cells obtained from patients before and after G-CSF administration showed no difference in cell cycling. Correlation between G-CSF concentrations and ANC showed a negative association indicating that the regulatory mechanisms for G-CSF production remained intact. In our relatively small series, CI ara-C achieved a CR rate of 44% with rhG-CSF having no effect on the remission rate. Although in vitro rhG-CSF increased the percentage of blasts in S phase significantly, in vivo effects were not observed. Larger studies with combinations of different hematopoietic growth factors and cell-cycle active drugs are needed to evaluate the role of these cytokines in the therapy of recurrent AML.

Prenatal analysis of rhesus CcDEe blood groups by heteroduplex generator.

OBJECTIVE: Our purpose was to determine the efficacy of the heteroduplex generator in the prenatal analysis of rhesus CcDEe blood groups. STUDY DESIGN: A cross-sectional study was performed evaluating fetal samples from 85 women undergoing prenatal diagnosis and comparing the results with standard immunologic serotyping on cord blood delivery. RESULTS: Of the 85 samples, 64 were tested, for all CcDEe alleles: one case was discrepant. Twenty-one cases were tested solely for the D antigen. Two novel genotypes were detected in the population by heteroduplex generator and confirmed by deoxyribonucleic acid sequencing. Five cases were indeterminate because of an indistinct banding pattern. CONCLUSIONS: Heteroduplex analysis can identify rhesus blood group alleles and is inexpensive, rapid, and does not use radioactive isotopes.

Monosomy 7 myelodysplastic syndrome and other second malignant neoplasms in children with neurofibromatosis type 1.

BACKGROUND: Children with neurofibromatosis type 1 (NF1) are at increased risk of developing benign and malignant solid tumors as well as hematologic malignancies, including de novo juvenile chronic myelogenous leukemia, monosomy 7 syndrome, and acute myelogenous leukemia. The normal NF1 allele is frequently deleted in the bone marrow cells from NF1 patients with hematologic malignancies, suggesting a pathogenic role in primary leukemogenesis. The authors report monosomy 7 myelodysplastic syndrome (MDS) as a second malignant neoplasm (SMN) in five children with sporadic NF1, the results of molecular analysis for NF1 and ras alterations in their bone marrow, and summarize their experience with SMNs in pediatric patients with NF1. METHODS: Monosomy 7 MDS was diagnosed as an SMN in five children with NF1 by morphologic and cytogenetic studies of bone marrow specimens. DNA extracted from these malignant bone marrows was analyzed for allelic loss at the NF1 locus and for the presence of ras mutations. The Children's Hospital of Philadelphia (CHOP) Tumor Registry was also reviewed to estimate the incidence of SMNs in pediatric NF1 patients. RESULTS: Bone marrow specimens from four patients retained constitutional heterozygosity at the NF1 locus; one specimen was uninformative. There was no evidence of activating ras mutations. The risk of an SMN was approximately 11% among the 64 NF1 registrants with primary malignancies in the CHOP registry, but was 75% (6 of 8) among patients treated for a pediatric embryonal cancer. CONCLUSIONS: Children with NF1 are susceptible to the development of malignant myeloid disorders both as a primary event and as an SMN. Additional molecular genetic analysis is necessary to determine if the NF1 gene is inactivated by somatic mutation in these secondary leukemias.

Role of irradiation in management of synovial sarcoma: St. Jude Children's Research Hospital experience.

The role of irradiation in the management of synovial sarcoma (SS) in pediatric patients is evaluated. The review covers all children seen at St. Jude Children's Research Hospital between May 1969 and December 1992 with the diagnosis of soft tissue sarcoma, of the 37 patients with the subtype SS, 16 received irradiation for the management of primary site disease. There were four IRS Group I, six Group II, four Group III, and two Group IV patients receiving irradiation. Tumor grade included seven Grade II, and nine Grade III lesions. TMN staging identified eight T1 and eight T2 lesions. Follow-up has ranged from 14 to 117 months (med = 33 months). All IRS Group I patients had documented local control. Five of six IRS Group II and 4/4 Group III patients have had documented local control at last follow-up. IRS Group IV patients had either local control tumor stabilization (n=1) or evidence of tumor regression (n=1) at autopsy. Complications following irradiation include wound dehiscence (n=1), surgery to revise a painful scar (n=1) extremity length discrepancy (n=2), and femoral head avascular necrosis (n=1). At last follow-up, 10 of 14 patients receiving curative intent irradiation remain alive. This review indicates questionable benefit to the addition of irradiation for patients with adequate surgical resection and having "good" tumor characteristics (Grade I, II; IRS Group I, TMN T1A,T1B. For lesions that have had incomplete resection or partial response to chemotherapy, there is evidence that irradiation may provide durable local control. The role of irradiation in those patients with IRS Group IV disease is at present confined to palliative roles until the time when more effective chemotherapy will mandate the decision to treat primary disease for curative measures.

Heteroduplex generator in analysis of Rh blood group alleles.

We describe the use of heteroduplex analysis to enhance the resolution of different rhesus-derived (Rh) isotypes. Heteroduplex analysis of different domains of the Rh D and Rh CE loci can be performed to diagnose a variety of blood group incompatibilities. One application of this technique is the ability to test for fetal-maternal blood group incompatibilities during pregnancy. Several new serotype-specific sequence variations were discovered in the mapping of the Rh locus, and used in the construction of artificial heteroduplex generators (HGs). HGs facilitate the resolution of the Rh isotypes by electrophoretic methods.