Circulating CD19+ blood cell levels in myeloma. ECOG Myeloma Clinical Trials Laboratory Study Group.
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Antibodies, Monoclonal↗
Biomedical subjects
T Leong
Publications and source records attributed to T Leong.
Life-span, T-cell responses, and incidence of lymphomas in congenic mice.
Survival, T-cell functions, and postmortem histopathology were studied in H-2 congenic strains of mice bearing H-2b, H-2k, and H-2d haplotypes. Males lived longer than females in all homozygous and heterozygous combinations except for H-2d homozygotes, which showed no differences between males and females. Association of heterozygosity with longer survival was observed only with H-2b/H-2b and H-2b/H-2d mice. Analysis using classification and regression trees (CART) showed that both males and females of H-2b homozygous and H-2k/H-2b mice had the shortest life-span of the strains studied. In histopathological analyses, lymphomas were noted to be more frequent in females, while hemangiosarcomas and hepatomas were more frequent in males. Lymphomas appeared earlier than hepatomas or hemangiosarcomas. The incidence of lymphomas was associated with the H-2 haplotype--e.g., H-2b homozygous mice had more lymphomas than did mice of the H-2d haplotype. More vigorous T-cell function was maintained with age (27 months) in H-2d, H-2b/H-2d, and H-2d/H-2k mice as compared with H-2b, H-2k, and H-2b/H-2k mice, which showed a decline of T-cell responses with age.
Animals↗
A phase II study of interleukin-2 with and without beta-interferon in the treatment of advanced renal cell carcinoma.
BACKGROUND: Biologic response modifiers have activity in renal cell carcinoma. The combination of interleukin-2 (IL-2) and beta-interferon (B-IFN) is synergistic in vitro. This trial was initiated to determine the efficacy of IL-2 alone and with B-IFN in advanced RCC. METHODS: Ambulatory patients with advanced RCC were randomly allocated to either IL-2 6 x 10(6) units/M2 intravenously (IV) three days a week for four weeks or IL-2 5 x 10(6) units/M2 IV plus B-IFN 6 x 10(6) units/M2 IV three days a week for 4 weeks. This induction phase was followed by a maintenance phase of the same drugs and doses administered for two weeks out of every four. RESULTS: 84 patients were entered onto this phase II trial with 75 considered eligible for response and survival. Toxicity is reported for the 81 patients on whom data was received, irrespective of eligibility. The overall response rate (RR) was 9.3% (7/75). Of the 3 responses in the IL-2 arm (RR = 8.3%), one was a complete response. 4 patients in the IL-2 + B-IFN arm (RR = 10.3%) achieved a partial response. Median survival was estimated to be 8.4 months for patients given IL-2 and 8.0 months for patients given the IL-2 and B-IFN combination. Multivariate analysis of survival data identified initial performance status, metastases of > 1 site, and weight loss as being important prognostic factors for survival. There were 2 lethal and 3 life threatening toxicities with the IL-2 treatment. While there were no lethal toxicities on the combination arm, there were 4 life threatening toxicities. CONCLUSIONS: The results of this study indicate that further investigation of IL-2 with or without B-IFN at this dose and schedule as treatments for renal cell carcinoma is probably not warranted.
Adult↗
Sequential phenotyping of myeloma patients on chemotherapy: persistence of activated T-cells and natural killer cells.
To better detail the status of functional T cell subsets and natural killer cells in multiple myeloma, we undertook a detailed immunophenotypic study of circulating mononuclear cells in myeloma. We studied myeloma patients entered on a large prospective, randomized ECOG chemotherapy trial EST 9486 for patients with newly diagnosed multiple myeloma. All patients were studied prior to entry and then two months after initiation of therapy (e.g. post two cycles of Vincristine, BCNU, melphalan, cyclophosphamide and prednisone (VBMCP)). The chemotherapy protocol was a three-arm protocol utilizing either VBMCP, VBMCP alternating with interferon, or VBMCP with intermittent high dose cyclophosphamide. The major findings in this analysis include significant reductions in the white blood cell count, total lymphocytes, T cell (CD3+), T helper (CD4+), and T suppressor (CD8+) cells, after 2 cycles of VBMCP. However, there was a relative sparing of Natural killer (CD16+) and activated T cell (CD2+, HLADR+) reduction in these same patients. In summary, only two cycles of combination chemotherapy resulted in significant reductions in white blood cell and lymphocyte counts in multiple myeloma patients. All cell types appear to have been reduced by chemotherapy except for activated T cells and natural killer cells. The impact of selective modulation of functional T cells subsets during therapy for patients with multiple myeloma is an important parameter which needs to be addressed in the overall approach to these patients.
Flow Cytometry↗
A phase II study of menogaril (7R-O-methylnogarol) in patients with relapsed/refractory acute myeloid leukemia: a study of the Eastern Cooperative Oncology Group.
Fifty-one patients (47 evaluable) with AML, 27 in first relapse and 20 either in second relapse or refractory were treated with menogaril, 100 mg/m2/day as a 90-min infusion daily for 5 days. The complete response (CR) rate was 17% (8/47), and there was one partial response. Seven of eight responders were in first relapse with a 26% response rate among first relapse patients (7/27). The median duration of survival was 3 months for all first relapse patients and 4.3 months for all other patients. Toxicity included grades 3-4 pancytopenia and fever (100% of patients) and grades 3-4 stomatitis and hepatic enzyme elevation (25% of patients). Grades 3-4 cardiac toxicity occurred in three patients (two grade 3 arrhythmias and one heart block). All had previously received anthracyclines. Remission duration was 1.6-48+ months; two patients underwent bone marrow transplantation and continue in CR at 36+ and 48+ months. The nontransplanted patients remained in CR 1.6, 2.0, 3, 7, 14 and 27 months. Activity and toxicity of menogaril in this study were comparable to that of other clinically useful anthracyclines in AML. Further investigation of this agent in AML is warranted.
Acute Disease↗
Inhibition of calcineurin phosphatase activity in adult bone marrow transplant patients treated with cyclosporine A.
In vitro studies have demonstrated that cyclosporine A (CsA) acts by inhibiting the phosphatase activity of calcineurin, an important mediator of T-cell activation. The relationship of CsA administration in vivo, calcineurin activity, and graft-versus-host disease (GVHD) has yet to be studied. The calcineurin activities of mononuclear cells isolated from 62 bone marrow transplant recipients and 12 normal volunteers were determined and analyzed with respect to administration of CsA, presence or absence of CsA in plasma, and presence or absence of GVHD. Of 62 patients, 33 were taking CsA and 29 were not. Early posttransplant (< 100 days), the calcineurin activity of patients on CsA was significantly lower than that of patients not on CsA (P = .0004) and than that of normal volunteers (P < .0001). Similarly, late posttransplant (> 100 days), the calcineurin activity of patients taking CsA was inhibited compared with normal volunteers (P < .05). The calcineurin activity of patients with acute GVHD who were taking CsA was lower than that of patients on CsA without acute GVHD matched for time posttransplant (P = .02). Calcineurin activity in patients on CsA with chronic GVHD was similar to those without chronic GVHD on drug. In conclusion, calcineurin activity is significantly suppressed by in vivo administration of CsA. The lower calcineurin activity of patients on CsA with acute GVHD suggests that CsA-resistant GVHD is not the result of inadequate suppression of calcineurin activity. These data suggest that if inhibition of calcineurin is the only physiologic target of CsA administration, simply increasing doses of CsA or treatment with other inhibitors of calcineurin, such as FK506, would not be expected to ameliorate GVHD.
Acute Disease↗
Seizures in children with supratentorial astroglial neoplasms.
We reviewed the records of 98 consecutive patients, 18 years of age or younger, with pathologically confirmed supratentorial astroglial neoplasms at the Children's Hospital, Boston, to evaluate the importance of seizures in their presentation and natural history. Tumors were diagnosed using the WHO criteria as pilocytic astrocytomas, astrocytomas, anaplastic astrocytomas, glioblastomas, giant cell glioblastomas, oligoastrocytomas and gangliogliomas. Our results were as follows. (1) Fifty percent of children had seizures as part of their presentation and 30% had seizures as their only presenting phenomenon. (2) The seizures varied in nature, but complex (55%) or simple (28%) partial seizures were by far the most common types, occurring in 77% of cases. (3) Preoperative electroencephalography (EEG) accurately lateralized to the tumor side in 88% of the cases and localized to the correct lobe in 56%. (4) Tumors involving cerebral cortex significantly correlated with seizures at presentation as compared to noncortical locations; 59% of patients with cortical tumors presented with seizures, and only 15% of patients with noncortical tumors experienced seizures. Lesions in the temporal and frontal lobes had the highest incidence of seizures. (5) Patients with gangliogliomas and oligoastrocytomas had the highest incidence of seizures, 88 and 86%, respectively, whereas patients with anaplastic astrocytoma had the lowest incidence, 21%. (6) Histopathologic calcification was associated with seizures at presentation approaching significance (p = 0.06). (7) Seizures at presentation were significantly associated with good prognosis (p = 0.02).
Adolescent↗
Ofloxacin compared with chloramphenicol in the management of external ocular infection.
The safety and efficacy of 0.3% ofloxacin in treating bacterial ocular infections was compared with that of 0.5% chloramphenicol in a parallel-group, randomised clinical trial at five sites. Clinical and microbiological improvement rates were studied in 84 culture-positive patients. Patients with suspected bacterial ocular infections were evaluated for clinical improvement and were included in drug safety and comfort analyses. Clinical improvement did not differ significantly between drug treatments. All patients completing the study (79 assigned ofloxacin, and 74 chloramphenicol) showed clinical improvement. Clinical improvement in the culture-positive groups was 100% (41/41) after ofloxacin treatment, and 95% (41/43) after chloramphenicol treatment. Microbiological improvement rates were similar for the two drugs: 85% (33/39) improved with ofloxacin, and 88% (38/43) improved with chloramphenicol. Both drugs were well tolerated. Adverse reactions possibly due to the study medication occurred in 1% (1/89) of those who received ofloxacin, and in 4% (4/93) of those who received chloramphenicol.
Adult↗
Shunt nephritis. Case report.
The incidence of shunt nephritis has decreased over the past several years due to the increased use of ventriculoperitoneal (VP) shunts rather than the ventriculovascular systems for which this complication was originally reported in 1965. Despite this trend, the syndrome has been reported in cases of VP shunting and, for this reason, merit a renewed look. Shunt nephritis is thought to be secondary to immune complex formation and deposition in the kidney in response to Staphylococcus epidermidis. The diagnostic workup and management of this disease is discussed.
Adult↗
A demonstration of the intrinsic importance of stabilizing hydrophobic binding and non-covalent van der Waals contacts dominant in the non-covalent CC-1065/B-DNA binding.
The comparative DNA binding properties and cytotoxic activity of CDPIn methyl esters (n = 1-5) vs. PDE-In methyl esters (n = 1-3) are detailed in studies which provide experimental evidence for the intrinsic importance of stabilizing hydrophobic binding and non-covalent van der Waals contacts dominant in the CC-1065/B-DNA minor groove binding. High affinity minor groove binding to DNA was established through: (1) the observation of CDPI3 binding (UV) but not unwinding of supercoiled DNA (phi 174 RFI DNA) thus excluding intercalative binding; (2) the observation of CDPI3 binding to T4 phage DNA (UV, delta Tm) in which the major groove is occluded by glycosylation thus excluding major groove binding; (3) the observation of salt (Na+) concentration independent high affinity CDPI3 binding to poly(dA . poly(dT) thus excluding simple electrostatic binding to the DNA phosphate backbone; and further inferred through (4) the observation of an intense induced dichroism (ICD, poly(dA) . poly(dT) and poly(dG) . poly(dC) [phi]23(358) = 24,000 and 23,500). This high affinity minor groove binding is sufficient to produce a potent cytotoxic effect.(ABSTRACT TRUNCATED AT 400 WORDS)
Animals↗
A new approach to the synthesis of a protected 2-aminopurine derivative and its incorporation into oligodeoxynucleotides containing the Eco RI and Bam HI recognition sites.
A protected 2-aminopurine nucleoside suitable for incorporation into oligodeoxynucleotides using phosphite triester chemical synthesis procedures has been prepared via oxidation of a purine hydrazino derivative with silver (I) oxide. Five oligodeoxynucleotides containing Eco RI and Bam HI recognition sites have been prepared such that, in the double stranded form, the 2-aminopurine base has either a complementary thymine or cytosine nucleobase. The helix character and thermodynamic parameters for helix formation have been examined.
2-Aminopurine↗