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Biomedical subjects

R M Meyer

Publications and source records attributed to R M Meyer.

At least 19 recordsLinked to original sources
PubMed1995

CD2+, CD3-, CD56/NCAM+ malignant lymphoma with TCR beta gene rearrangement: a case report.

A case of CD56/NCAM+ malignant lymphoma is reported. Only a rare malignant lymphoma cell showed azurophilic granules in the cytoplasm of Giesma-stained preparations, while electron microscopic examination revealed occasional cytoplasmic granules with paracrystalline inclusions. The most common phenotype seen in NK lymphomas, CD2+, CD3-, CD56+, CD16-, CD57-, was present in the case. Cases with this phenotype have been interpreted to represent either true NK lymphoma or T-cell lymphoma with NK expression. Genotyping, where performed, has shown TCR germline configuration. Our case showed TCR beta rearrangement indicating that the above phenotype can be associated with a peripheral T-cell lymphoma.

Aged↗
PubMed1995

Randomized phase II comparison of standard CHOP with weekly CHOP in elderly patients with non-Hodgkin's lymphoma.

PURPOSE: To determine whether modifying the standard regimen of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) from full doses given every 3 weeks to one-third doses given weekly (chop) increases the received chemotherapy dose-intensity in elderly patients with advanced-stage intermediate-grade lymphoma. PATIENTS AND METHODS: Consenting patients, age > or = 65 years who had acceptable cardiac, renal, and liver function and an Eastern Cooperative Oncology Group (ECOG) performance status less than 4, were stratified by bone marrow and performance status and randomized to receive standard CHOP or weekly chop. Drug doses were attenuated or escalated according to a defined dose-modification schedule. The primary outcome was average relative received dose-intensity. Secondary outcomes included response, progression-free and overall survival, toxicity, and performance status. RESULTS: Nineteen patients were allocated to each group. No difference in received dose-intensity was seen. When dose-intensity was calculated for the first six cycles of therapy, average relative received dose-intensity was .92 with CHOP versus .89 with weekly chop (P = .5); when calculated for the first 18 weeks of therapy, values were .88 with CHOP versus .89 with weekly chop (P = .8). The complete response rate was 68% with CHOP versus 74% with weekly chop (P = .9). At 2 years, the progression-free survival rate was 57% with CHOP versus 46% with weekly chop (P = .16) and the survival rate was 74% with CHOP versus 51% with weekly chop (p = .05). More myelotoxicity was seen with CHOP. CONCLUSION: We conclude that CHOP can be given in sufficient doses to elderly patients and that weekly chop does not increase received dose-intensity. Progression-free and overall survival are unlikely to be superior with weekly chop, and may be worse. CHOP should remain the standard against which new therapies for elderly patients with intermediate-grade lymphoma are compared.

Aged↗
PubMed1994

Relation between platinum-DNA adducts and complete remission in adult acute nonlymphocytic leukemia.

The purpose of this study was to determine the relationship between platinum-DNA adducts in leukemic cells and the success of remission induction therapy in adult patients with acute nonlymphocytic leukemia (ANLL). Freshly isolated cells from pre-treatment bone marrow aspirates of 14 patients were incubated with cisplatin in vitro and the amount of platinum bound to DNA was determined using a competitive ELISA procedure and an antibody directed against platinum-modified DNA. Platinum-DNA adduct levels discriminated well between complete remission (CR) and remission failure (RF) patients, treated with mitoxantrone, cytosine arabinoside +/- carboplatin.

Adolescent↗
PubMed1993

Escalated as compared with standard doses of doxorubicin in BACOP therapy for patients with non-Hodgkin's lymphoma.

BACKGROUND AND METHODS: In 1981 the Clinical Trials Group of the National Cancer Institute of Canada completed a pilot study in patients with advanced-stage non-Hodgkin's lymphoma with aggressive tumor histology. That study demonstrated the potential efficacy of escalating the dose of doxorubicin used in a regimen of bleomycin, doxorubicin, cyclophosphamide, vincristine, and prednisone (BACOP). In the present study, we compared standard BACOP (s-BACOP) with BACOP that included escalated doses of doxorubicin (esc-BACOP) in 238 patients 16 to 70 years old with previously untreated, advanced-stage intermediate- or high-grade non-Hodgkin's lymphoma. During the first 28-day cycle all patients received doxorubicin in a dose of 25 mg per square meter of body-surface area on days 1 and 8. Patients randomly assigned to receive s-BACOP subsequently received five identical cycles, whereas those assigned to receive esc-BACOP received 40 mg of doxorubicin per square meter on days 1 and 8 of five subsequent cycles if granulocytopenia (< 1000 cells per cubic millimeter) had not developed during the first cycle. RESULTS: The 119 patients assigned to the esc-BACOP regimen received doxorubicin at a significantly higher mean weekly dose intensity (13.5 vs. 10.4 mg per square meter per week, P < 0.001) and mean total dose (296 vs. 231 mg per square meter, P < 0.001). Because of granulocytopenia during the first cycle of therapy, only 56 of these patients (47 percent) received the escalated doses of doxorubicin. During a median follow-up of 65 months, there were no differences between the s-BACOP and esc-BACOP groups in response rate, overall survival, or survival without disease progression. When the patients who actually received the escalated doses of doxorubicin were compared with the patients in the s-BACOP group in whom neutropenia did not develop during the first treatment cycle, no difference between their outcomes was observed. Toxicity was greater in the esc-BACOP group. CONCLUSIONS: In patients with advanced-stage intermediate- or high-grade non-Hodgkin's lymphoma, escalating the dose of doxorubicin in the BACOP regimen increases toxicity but does not improve the rate of response or survival.

Adolescent↗
PubMed1992

A pilot study of carboplatin augmentation therapy for patients with poor risk acute non-lymphocytic leukemia.

Eleven patients with acute non-lymphocytic leukemia and persistent leukemia on a bone marrow done 6 days after the start of standard induction chemotherapy with daunorubicin and cytosine arabinoside were given augmentation chemotherapy with carboplatin as a continuous intravenous infusion over 3 days. Nine of the 11 patients (82%) entered complete remission. The hematologic and non-hematologic toxicities encountered by these patients were similar to those seen after conventional therapy alone with the exception of peripheral neuropathy in one patient. Of the two induction failures, one patient died of treatment-related toxicity and one patient had resistant leukemia.

Adolescent↗
PubMed1991

The role of dose intensity in determining outcome in intermediate-grade non-Hodgkin's lymphoma.

To determine whether the dose intensity of chemotherapeutic regimens correlates with the complete remission rate in adult patients with advanced-stage intermediate-grade lymphoma, reports of comparative trials of therapy were reviewed. Reports were identified using MEDLINE, through references from review articles, and through review of selected abstracts. Twenty-two studies including 14 randomized and eight cohort trials were analyzed to assess projected dose intensity. Four other studies were analyzed to assess the role of received dose intensity. Dose intensities were calculated using described methods and correlated with complete remission rates. Individual trials were assessed using "levels of evidence." A metaanalysis of randomized trials and a cross-trial analysis of all comparative trials using a weighted least squares linear regression were performed. Using levels of evidence, support was obtained for the hypothesis that dose intensity correlates with the remission rate from two trials in which dose intensity was "indirectly" tested. As these studies did not "directly" test dose intensity, confounding variables, including those arising from the assumptions made in calculating dose intensity, cannot be excluded. Metaanalysis showed a relative probability of achieving complete remission of 1.34 (95% confidence interval, 1.13 to 1.58) favoring the pooled arm of high dose intensity. Cross-trial analysis showed a relatively weak association between dose intensity and remission rate (r = .49, P = .0001). Two of four reports retrospectively assessing received dose intensity suggested that increased dose intensity is associated with superior remission rates. These analyses suggest that dose intensity may correlate with the remission rate in advanced-stage intermediate-grade lymphoma. However, properly designed trials directly testing dose intensity have not been performed and are needed to confirm this hypothesis.

Antineoplastic Agents↗
PubMed1990

Oxygen analyzers: failure rates and life spans of galvanic cells.

Competing technologies exist for measuring oxygen concentrations in breathing circuits. Over a 4-year period, two types of oxygen analyzers were studied prospectively in routine clinical use to determine the incidence and nature of malfunctions. Newer AC-powered galvanic analyzers (North American Dräger O2med) were compared with older, battery-powered polarographic analyzers (Ohmeda 201) by recording all failures and necessary repairs. The AC-powered galvanic analyzer had a significantly lower incidence of failures (0.12 +/- 0.04 failures per machine-month) than the battery-powered polarographic analyzer (4.0 +/- 0.3 failures per machine-month). Disposable capsules containing the active galvanic cells lasted 12 +/- 7 months. Although the galvanic analyzers tended to remain out of service longer, awaiting the arrival of costly parts, the polarographic analyzers were more expensive to keep operating when calculations included the cost of time spent on repairs. Stocking galvanic capsules would have decreased the amount of time the galvanic analyzers were out of service, while increasing costs. In conclusion, galvanic oxygen analyzers appear capable of delivering more reliable service at a lower overall cost. By keeping the galvanic capsules exposed to room air during periods of storage, it should be possible to prolong their life span, further decreasing the cost of using them. In addition, recognizing the aberrations in their performance that warn of the exhaustion of the galvanic cells should permit timely recording and minimize downtime.

Anesthesia, Closed-Circuit↗
PubMed1986

Effect of monensin on the performance of cattle on pasture or fed harvested forages in confinement.

Three series of trials were conducted to evaluate the effect of monensin on the growth performance of cattle. Twenty-four trials were conducted to evaluate the addition of monensin at 200 mg/d to limited quantities of supplemental concentrate for growing cattle grazing pastures. The pastures ranged from dormant end-of-the-season grasses and crop residues to lush green pastures, and were located in several different states. Pasture plus supplement supported gains of control cattle (without monensin) of .24 to .96 kg, with an average of .56 kg/d. The addition of 200 mg monensin to the supplement increased daily gain in all 24 trials by an average of .09 kg daily (+16.3%). Eleven trials were conducted with monensin and energy supplements fed at .907 kg.- head-1 X d-1 to growing cattle grazing growing, nondormant pastures for an average period of 117 d. Each trial was designed to compare the performance of unsupplemented cattle, cattle fed a supplement and cattle fed a supplement with monensin. Cattle on pasture gained .50 kg daily. Supplement feeding increased average daily gain by .09 kg and the addition of monensin to the supplement further increased gain by .09 kg, for a total increase of .18 kg (34.2%). The efficiencies with which supplemental feed was converted to extra gain (kg supplement/kg gain) for the supplement-only and the monensin treatment groups were 10.1:1 and 5.0:1, respectively. In a series of 12 trials, monensin was added at a level of 33 mg/kg air-dry diet to limited quantities of supplemental feed for cattle fed harvested forages in confinement. All trials compared monensin feeding with a nonmedicated control treatment. Hay was fed in 8 of the 12 trials, fresh-cut green-chop in two trials and ensiled corn stover and ensiled milo stover in one trial each. Monensin reduced feed intake by -3.1%, improved average daily gain by .09 kg (+14.4%) and improved feed efficiency by 15.3%.

Animal Feed↗
PubMed1986

Classifying acute leukemia by immunophenotyping: a combined FAB-immunologic classification of AML.

A panel of commercially available monoclonal antibodies and five heteroantisera were used to distinguish and subtype 138 cases of acute leukemia (AL). The immunophenotype was compared with the French-American-British (FAB) classification obtained on the cases. The immunophenotype discriminated acute myelogenous leukemia (AML) from acute lymphoblastic leukemia (ALL) and recognized cases not distinguished by cytochemistry (22% of cases), mixed lineage phenotypes (13% of cases), and cases with separate populations of lymphoblasts and myeloblasts (one case). Using the immunologic panel and derived criteria to subtype AML, correspondence of the immunophenotype to the FAB subtypes M1, M2, M4, and M5 was possible in greater than 80% of cases. A combined classification of the immunophenotype and FAB morphology/cytochemistry was devised for AML subtyping. It is recommended that immunophenotyping should be done at least in all cases with negative or inconclusive cytochemistry. At present, we suggest that until a "gold standard" for identifying leukemic subtypes is developed, the best method for typing acute leukemia is by using a combination of morphology, cytochemistry and immunophenotyping.

Antibodies, Monoclonal↗