PubMed HealthSearch

Biomedical subjects

D Lutz

Publications and source records attributed to D Lutz.

At least 19 recordsLinked to original sources

Indications for the presence of antibodies cross-reactive with HTLV-I/II, but not HIV, in patients with myelodysplastic syndrome.

Serological evidence is presented for the fact that patients with the myelodysplastic syndrome exhibit a statistically significant reactivity in confirmatory assays for antibodies to human T-lymphotropic viruses types I and II (HTLV-I/II). This antibody reactivity, evident by indirect immunofluorescence and Western blot, was not confined to HTLV core antigens but extended to native and recombinant envelope glycoproteins. The effect was also observed in cases of acute myeloic leukemia, albeit to a lesser degree. It was essentially absent from patients with chronic myeloic leukemia or lymphocytic leukemias and healthy or multitransfused controls. No antibodies to human immunodeficiency viruses types 1 or 2 were detected in any of the specimens. The investigated clinical population had no known risk factor for retroviral infection other than a history of multiple platelet transfusions, and none of the specimens was seropositive for HTLV-I or HTLV-II according to recommended criteria. The cause of this cross-reactivity remains to be determined.

Antibodies, Viral

Remission may continue after termination of rIFN alpha-2b treatment for essential thrombocythemia.

Essential thrombocythemia, a myeloproliferative disorder of clonal origin, is often associated with various clinical manifestations resulting from thromboembolic or hemorrhagic complications. The long-established successful method of treatment with cytotoxic agents or radioactive phosphorus has recently been superseded by interferon alpha. We treated 14 symptomatic patients with 5 x 10(6) IU recombinant interferon alpha-2b s.c. daily. 12/14 pts responded within 14-75 days. When platelet counts decreased to below 450 g/l the frequency of administration was reduced stepwise. 7 patients remained in CR during this reduction phase and treatment was stopped in 5 pts after 12-32 months. Until now, 3 of them are still in continuous good PR without any drug therapy and free of symptoms for 3+, 19+ and 36+ months. Continuous response during maintenance was associated with age, initial platelet count and time required to reduce platelet counts to less than 450 g/l.

Adult

Childhood acute lymphoblastic leukemia immunophenotypes and their prognostic significance: experience of the IGCI-study in 389 children. International Society for Chemo-immunotherapy (IGCI-Vienna) Cooperative Group.

The prognostic significance of immunophenotype and other features including sex, age, anaemia, WBC, FAB type, and PAS staining were analysed in a group of 389 children newly diagnosed as acute lymphoblastic leukemia (ALL) and treated according to the BFM 1981/1983 protocol. The CR rate was higher (82-94%) in immunophenotypic subgroups defined as 'non-B' compared with B-ALL (54%). The probability of being in CCR at the end of follow up was 0.68 (median. observation, 3 years). Using the stepwise Cox regression analysis the following independent factors predictive of duration of CCR were selected (relative risk in brackets): 1. WBC (> 25G/1:< 25G/1 = 2.0, P = 0.0008), 2. age (> 10y:2-10y = 1.3, P = 0.04), 3. CALLA positivity (neg.:posit. = 2.4, P = 0.04), 4. CALLA within B-cell progenitor ALL (pre;preB,Calla-:Calla+ = 1.7, P = 0.007). T-ALL appeared to have a worse prognosis than U-ALL and B-progenitor derived ALL but it did not retain independent prognostic significance in multivariate analysis.

Adolescent

Contractile proteins in Drosophila development.

In summary, we have used a multidisciplinary approach to the analysis of actomyosin-based motility during Drosophila embryogenesis. We have documented the movements of early embryogenesis with modern, video methods. We have characterized the cytoplasmic myosin polypeptide, made specific polyclonal antisera to the molecule, studied its distribution during early embryogenesis, cloned and partially characterized the gene that encodes it, and have recently completed the nucleotide sequence of a nearly full length cDNA that encodes the entire protein-coding region. We have initiated studies on myosin function in living embryos both by direct microinjection of antibodies and through classical genetics. To better understand how myosin function is regulated, we have begun analysis of its light chains. Finally, to investigate the molecular mechanism by which its function is integrated into a labile cytoskeleton, whose architecture is constantly changing, we have also investigated Drosophila spectrins. Together, these studies are designed to shed light on the dynamics of biologic form at the cellular level, with current focus on such complex processes as cytokinesis and morphogenesis.

Actins

Terminal deoxynucleotidyl transferase and CD7 expression in acute myeloid leukemias are not associated with a high frequency of immunoglobulin and/or T cell receptor gene rearrangement.

Within normal hemopoiesis, the intranuclear DNA polymerase TdT seems to be exclusively expressed by T and B lymphoid precursor cells. Double staining experiments showed that TdT can also be expressed in blast cells of certain acute myeloid leukemias. Recent reports described a very strong association between TdT expression and rearrangements of IgH and TcR genes in such AML specimens, suggesting a predominant lymphoid commitment of these TdT positive AML blasts. When submitting 24 serologically and morphologically well-characterized TdT positive AML specimens for additional genotypic analysis to determine the IgH and TcR gene configuration, we observed that only four had clonally rearranged IgH and/or TcR genes, whereas 20 had germ line configuration. This frequency is clearly lower than previously reported and not necessarily different from rearrangement frequencies reported for TdT negative AML (4-40%). It would seem to us, therefore, that the expression of TdT in otherwise well-defined AML blasts is not necessarily associated with a higher frequency of immunoglobulin and/or T cell receptor gene rearrangement.

Antigens, CD7

Trisomy 4: a specific karyotype anomaly in primary and secondary acute myeloid leukemia.

Trisomy 4 as single karyotype anomaly has recently been proposed as an acute myeloid leukemia (AML) specific aberration. Up to now, 20 cases have been reported in which the single abnormality occurred without additional chromosomal aberrations. Trisomy 4 has been found in both primary and secondary AML, the majority of cases being diagnosed as FAB M4 or M2 subtypes. In the cytogenetic analysis of 305 patients with AML, we found 209 cases with aberrant karyotypes, among them two patients (22a, male, M2; and 69a, male, M4) with trisomy 4 as single aberration. The younger patient achieved complete remission lasting 13 months and survived 22 months whereas the older patient died in aplastic phase due to septicaemia 5 weeks after admission. Trisomy 4 is proposed to be the primary aberration in both these cases of de novo AML. Although in one case, as in two cases reported earlier, cytogenetic results were only available in first relapse, we have no indication that trisomy 4 appeared in a secondary induced leukemia, because the leukemic blasts of the relapse were morphologically identical to first acute phase. In contrast to other specific chromosomal aberrations, results indicate that trisomy 4 has as yet no prognostic relevance concerning the clinical outcome.

Adult

The expression of CD 15 antigen on myeloid leukaemia cells--a new prognostic index for complete remission and for survival.

377 untreated acute leukaemia patients were categorized according to FAB and cytochemical criterials and simultaneously phenotyped with the use of 6-21 monoclonal antibodies (MoAb) of VI series (W. Knapp, Vienna). The leukaemia phenotype was compared with the patients outcome after treatment. In adult ANLL patients a positive relationships was proved statistically between the expression of the CD 15 cell differentiation antigen on leukaemic blasts and the CR rate (p less than 0.01, chi 2 test). Also a comparison of the Kaplan-Meier survival curves revealed that the CD 15 positive group of ANLL patients has a better outcome than the CD 15 negative one (p less than 0.01, by Wilcoxon and Log-rank tests). Thus, examination of cell differentiation antigens could be a useful addition to existing risk assignment in acute leukaemia.

Antibodies, Monoclonal

Quantitative immunohistochemistry: standardization and possible application in research and surgical pathology.

We describe three different methods of calibration of quantitative immunohistochemistry, two of them based on self-made dye-agarose or antigen-agarose substrates. Quantification of immunostained objects (immunosignals) can be done by (1) microscope photometry (plug method) or scanning-photometry; (2) and densitometry of a television transformed microscope image. Both approaches are subjected to the different methods of calibration and three examples of application.

Arginase