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Biomedical subjects

B Lange

Publications and source records attributed to B Lange.

At least 127 records · Page 7Linked to original sources
PubMed1986

Incidence, presentation, and outcome of spinal cord disease in children with systemic cancer.

During a 40-month period, in 24 of 643 (4%) newly diagnosed patients with systemic cancer younger than 18 years of age (range: 3 months to 17 years) spinal cord disease developed. Patients with spinal cord disease included 21 children with metastatic spinal cord compression, two with treatment-related transverse myelopathies, and one with an anterior spinal artery stroke. Spinal cord disease occurred in 13 of 102 children (12%) with sarcomas, six of 82 (7%) with neuroblastomas, and four of 94 (4%) with lymphomas. Spinal cord compression occurred as the presenting sign of malignancy in six children (four with sarcomas and two with lymphomas). In the remaining 15 patients, cord compression occurred a median of 13 months after initial diagnosis, and in four patients it occurred at the time of first relapse. Symptoms of metastatic cord compression included back pain in 17 patients (80%), weakness in 14 (67%), sphincter dysfunction in 12 (57%), and sensory abnormalities in three (14%). Findings on plain radiographs of the spine were abnormal in only seven of 20 patients with cord compression, and myelography was needed to differentiate compression from other causes of spinal cord disease. Treatment included high-dose corticosteroids followed by operation (seven patients) or radiotherapy (14 patients). After treatment, nine of 15 nonambulatory patients became ambulatory, and five of 10 incontinent patients regained sphincter control. None of the patients with nonmetastatic spinal cord disease had a satisfactory outcome.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

Student perception of faculty role models.

Few studies have been conducted on the effect of faculty role models on dental students. Questionnaires were developed to compare faculty self-perceptions with dental students' perceptions of the role they desired to achieve. Results indicated a minimal relationship between the self-perceptions of faculty and the students' identification of their desired future role in the dental profession. Furthermore, faculty were not perceived by students as being the most influential in molding their feelings about the practice of dentistry.

Consultants↗
PubMed1985

Surface phenotypes of human hemopoietic progenitor cells defined by monoclonal antibodies.

A panel of ten monoclonal antibodies which react with antigens present on the surface of myeloid leukemic cells was used to investigate the distribution of these antigens on normal hemopoietic stem cells and progenitor cells at various stages of maturity. A population of immature cells, possibly stem cells, that are capable of regenerating CFU-GM in long-term marrow cultures reacts with four antibodies recognizing antigens abundantly expressed in leukemic cells, but does not react with antibodies against Ia-like molecules or against carbohydrate determinants specific for myeloid cells. Progenitor cells that form mixed colonies in semisolid medium (CFU-GEMM), early erythroid (BFU-E) and early myelomonocytic (type 1 CFU-GM) progenitors retain the antigens present on the hypothetical stem cell population and begin to express Ia-like antigens. As they differentiate, myeloid and erythroid progenitors undergo a series of quantitative and qualitative shifts in surface phenotype. They begin to express stage-related, lineage-specific antigens and cease expressing antigens common to early cells of different lineages. The identification of antigens present on very immature normal progenitor cells should be valuable in future studies aimed at the detailed characterization of this relatively little-known hemopoietic cell population.

Animals↗
PubMed1984

Increased levels of circulating HLA-DR antigen in sera of patients with acute lymphoblastoid leukemia.

Monoclonal antibodies that define HLA-DR antigen bind to a variety of human tumors, such as Burkitt lymphoma and melanoma cells grown in vitro and with the spent medium of these cultures. Two radioimmunoassays have been developed to detect HLA-DR antigen circulating in human sera. The inhibition assay is based on the inhibition of binding of monoclonal antibodies against HLA-DR to the target preparation; the double-determinant assay traces antigen bound by a solid-phase monoclonal antibody by the use of a second 125I-labeled antibody. Twenty-six of 39 sera from patients with acute lymphoblastoid leukemia, 2 of 29 sera from patients with acute myeloid leukemia, and 5 of 31 sera from patients with advanced metastatic melanoma showed increased levels of HLA-DR antigen, whereas none of 28 sera from patients with other malignancies had increased levels of HLA-DR antigen, and only 2 of 155 sera from healthy donors bound monoclonal antibodies to HLA-DR at detectable levels. The detection of circulating HLA-DR antigen in sera of cancer patients may be useful in monitoring patients with certain malignancies.

Antibodies, Monoclonal↗
PubMed1984

EEG-based multivariate statistical analysis of sleep stages.

All-night sleep of 5 healthy male subjects was scored on the basis of EEG (paper records), EMG and EOG into the stages of wakefulness, REM sleep and slow sleep stages 1-4 according to Rechtschaffen and Kales. Spectral analysis for 8 EEG channels was then performed and spectral parameters (total power and coherence for certain frequency bands) extracted. Stepwise linear discriminant analysis was applied to these spectral parameters to see how well the polygraphically defined sleep stages were recognized. While the results of each intrasubject analysis were satisfactory (error rates between 10 and 15%), a more detailed analysis revealed that most errors occur between nearby slow sleep stages or between S1 and REM or wakefulness. This is related to the fact that Rechtschaffen and Kales classify into discrete stages an essentially continuous process and this is, to some extent, arbitrary. This interpretation is supported by examples. Cross-classification of each subject on the basis of the remaining 4 increases the error rates drastically. A simple way of avoiding this effect, by standardizing the individual data, is shown to work nicely in this case.

Adult↗
PubMed1984

Subpopulation heterogeneity in human acute myeloid leukemia determined by monoclonal antibodies.

The leukemic population in 63 patients with acute myeloid leukemia (AML) was studied with 15 monoclonal antibodies that detect lineage-related and stage-related antigens on normal hemopoietic cells. Indirect immunofluorescence and fluorescence-activated cell sorting showed that subpopulations of leukemic cells reacted with some or all antibodies, but the percentage of cells reacting with a single antibody varied widely among patients. The composite antigenic phenotype of the various cases, as determined by immunofluorescence assay, did not correlate with the French-American-British morphological classification. Furthermore, some cells in each case failed to express any antigen normally expressed on myelomonocytic precursors from the level of the early CFU-GM to the mature granulocyte or monocyte. In double-fluorescence experiments, the individual cells expressed none, one, or both antigens. These results demonstrate that there is considerable subpopulation heterogeneity in AML. This heterogeneity may considerably limit or complicate the use of monoclonal antibodies for diagnosis, prognosis, and treatment of acute nonlymphocytic leukemia (ANLL).

Adult↗
PubMed1984

[Temporal dynamics of spectral EEG parameters during nocturnal sleep in healthy adults].

We recorded all-night sleep EEG's of six healthy male volunteers (age 23 to 29 years) from F3, F4, P3, P4, 01, 02, T3, T4 to Cz as reference electrode. Power and coherence spectra were calculated for ten frequency bands from 0-30 cps. We examined their changes through the different cycles of all sleep stages. In general there was a decrease in power as well as in coherence from the 1st to the 4th cycle of the different sleep stages with some variations depending on frequency and derivation. The highest power was most often in the 1st cycle in stages REM, 2, 3 and 4, whereas in stage 1 it was most often in the 2nd cycle. The trends in power from the 1st to the 4th cycle were similar for stages REM and 2 with a power decrease from the 1st to the 2nd cycle. In stage 1 there was most often a power increase between these two cycles. Coherence maxima were for stages REM, 1, 2 and 3 most often in the 1st cycle, for stage 4 most often in the 2nd cycle. The coherence trends were similar for stages 1 and 2 with a decrease most often from the 1st to the 2nd cycle. In stage REM the decline was more constantly found from the 2nd to the 3rd cycle. The power trends were more consistent than the coherence trends. We found more often similar power changes from the 1st to the 4th cycle of a specific sleep stage than similar coherence changes.

Adult↗
PubMed1984

Surface phenotype of clonogenic cells in acute myeloid leukemia defined by monoclonal antibodies.

Colony-forming cells in ten cases of acute myeloid leukemia (AML) were studied with six cytotoxic monoclonal antibodies that react with antigens expressed at discrete stages of differentiation of normal and leukemic hematopoietic cells. The reactivity of the whole leukemic population was measured by indirect immunofluorescence, and the reactivity of the colony-forming cells was established by complement-mediated cytotoxicity and by fluorescence activated cell sorting. Comparison of the immunofluorescent reactivity with cytotoxicity and cell sorting showed that colony-forming cells were found within a fraction of the leukemic subpopulations that expresses these antigens. This finding implies that immunofluorescence reactivity of the total leukemic population does not necessarily predict the phenotype of the clonogenic cells. When the surface phenotype of the clonogenic leukemic cells was compared to that previously established for normal marrow hemopoietic clonogenic cells, several patterns were seen: (1) in four of ten cases, the clonogenic cells expressed a phenotype like that of relatively mature normal granulocyte-macrophage colony-forming cells (late CFU-GM) or, (2) in two cases, a phenotype similar to the less mature colony-forming cells (early CFU-GM or CFU-GEMM), and (3) in four cases, a composite phenotype of early and late CFU-GM. Thus, the level of impairment of differentiation in AML may vary from case to case. In those cases phenotypically similar to the late CFU-GM, it may be possible to separate leukemic clonogenic cells from less mature normal clonogenic cells using monoclonal antibodies selectively cytotoxic for the late CFU-GM.

Antibodies, Monoclonal↗
PubMed1983

Management of Hodgkin's disease in children and adolescents.

Between 1970 and 1980, 66 children or adolescents with Hodgkin's disease were treated at the Children's Hospital of Philadelphia. Since 1977, prepubertal patients and postpubertal patients with Stage IIA massive mediastinal disease or Stage IIB-IVB disease were clinically staged and treated with six courses of chemotherapy and 2000 rad involved-field irradiation. Postpubertal patients with Stage IA or IIA disease were staged pathologically and treated with 3600-4400 rad extended-field irradiation. At four years, actuarial survival in 27 patients with Stage IA or IIA disease is 100%; relapse-free survival is 86% in 16 patients treated with combined modality and 70% in 11 patients treated with irradiation. Among 39 patients with Stage IIB-IVB disease, 34 received combined modality; at five years, survival is 86% and relapse-free survival is 60%. In the majority of cases relapses in patients treated with combined modality could be better explained by chemotherapy failure rather than by insufficient radiation. Clinical staging and combined modality therapy may offer advantages for prepubertal patients and those postpubertal patients at high risk of relapse when treated with irradiation alone. The complications of laparotomy and splenectomy are avoided; however, with 2000 rad and limited-field irradiation, hypothyroidism does occur and growth disturbances may appear.

Adolescent↗
PubMed1983

Cytogenetics of childhood preleukemia.

Chromosome studies were done on ten children with childhood preleukemia characterized by anemia, thrombocytopenia, blasts in the circulation, and hypercellular marrow with excess blasts. The syndrome was clinically similar to adult preleukemia (myelodysplastic disorder). A chromosomally abnormal clone was found in the marrow in five patients: three with monosomy 7; one with a chromosome No. 21 replaced by two isochromosomes for 21q; and one with multiple alterations including an extra, abnormal chromosome No. 7. It was not apparent that a karyotypic change indicated a worse prognosis. The observed chromosome abnormalities appeared to overlap less with those in acute nonlymphocytic leukemia occurring de novo than is the case in adults, perhaps reflecting differing contributions of genetic and environmental factors to the pathogenesis of the disease at different ages.

Acute Disease↗
PubMed1983

[Application of beta-rhythm quantification to the treatment of epilepsy].

Abundance of beta activity in epileptic patients under clonazepam (Rivotril) treatment shows a significant correlation with the suppression of epileptic seizures and/or of epileptic EEG activity such as spikes and spike/wave complexes. In a longitudinal two-year study in 21 children with severe epilepsy treated with clonazepam, relative spectral peak power (RSPP) of beta activity was correlated with daily dose and serum concentration as well as with its effect on seizures and on epileptic EEG activity. Eight cases showed significant correlation of beta RSPP to daily dose, but only 4 to serum concentration. A significant (inverse) correlation was found between beta RSPP and the relative occurrence of epileptic EEG activity. Most illustrative were the individual follow-ups, with beta RSPP as an interesting additional parameter regarding the course of the epileptic condition. Quantitative measurement of beta activity by means of spectral analysis during long-term antiepileptic treatment promises important additional information on specific aspects in the individual case.

Benzodiazepinones↗