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Biomedical subjects

D Lutz

Publications and source records attributed to D Lutz.

At least 55 records · Page 3Linked to original sources
PubMed1990

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↗
PubMed1990

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↗
PubMed1990

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↗
PubMed1989

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↗
PubMed1989

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↗
PubMed1989

Performance of a slow-release formulation of isosorbide-5-mononitrate (ISMO retard).

From the in vitro release-rate constant of a new sustained-release (SR) preparation of 40 mg isosorbide-5-mononitrate, the concentration-time profile in healthy subjects could be excellently predicted. Therapeutically, effective concentrations of 100 ng/ml were achieved within 20 min and lasted up to a maximum of 15.6 h. The decline of concentrations below this value thereafter, guarantees the absence of tolerance development in chronic therapy. In a three-period change-over study, two other commercial SR preparations exhibited only 79% and 53% of the bioavailability of the new formulation, which was significant in both cases. Compared with literature data, the absolute bioavailability of the new form should lie in the order of at least 85%.

Adolescent↗
PubMed1988

[The cytogenetics of acute leukemia].

Methodological prerequisites for the culture of leukaemic blasts and the fluorescence banding of spread metaphases are represented in detail. By using an improved method the percentage of aneuploid karyotype findings increased in AML from 49% to 68% and ALL from 65% to 81% of all evaluable patients. Specific aberrations known up to the present day are discussed. They could be diagnosed in 46% of aneuploid AML-clones and in 59% of ALL-clones. The fluorescence banding according to the three-colour technique is demonstrated by three examples of "non-specific" aberrations: a) Tandem translocation of 1q and 7 q (64a, male, FAB:M5B), b) Karyotype instability with variability of chromosome numbers arising from trisomy, tetrasomy and polyploidisation of single normal as well as marker chromosomes (57a, female, FAB:M6), c) Identification of a marker chromosome as a derivative chromosome 16 (33a, female, FAB:L2, c-ALL).

Adult↗
PubMed1988

Immunophotometric quantification of extravascular immunoglobulin deposits in the synovial membrane of patients with osteoarthritis and rheumatoid arthritis.

The amount of extravascular immunoglobulin deposits in the synovial membrane of patients with osteoarthritis and rheumatoid arthritis was studied in comparison with that of patients suffering from non-joint diseases. Immunoglobulin deposits were immunostained using the three-layer immunoperoxidase method. The staining results were quantified with the help of a microscope photometer connected with a scanning stage. Several experiments involving artificial test substrates, diseases with allegedly increased extravascular deposits or diseases not exhibiting extravascular deposits of immunoglobulins are used to validate the described microspectrophotometrical approach for measuring extravascular immunoglobulin deposits. The scanning photometry demonstrates significantly higher amount of extravascular immunoglobulin deposits in rheumatoid arthritis as compared with osteoarthritis and non-joint diseases.

Arthritis, Rheumatoid↗
PubMed1988

A new porcine bioprosthesis: design rationale and early clinical experience.

The Medtronic Intact valve is a third-generation porcine bioprosthesis produced using a leaflet fixation process which imposes virtually zero hydrostatic pressure. This fixation method provides optimal preservation of the original leaflet structure and integrity and should result in an improvement in durability compared to conventional preservation techniques. The biomechanical basis for this hypothesis is presented along with early experience with 118 patients (125 valves). There have been no complications related to primary valve failure and the incidence of other valve related events is acceptable.

Aortic Valve↗
PubMed1988

Serum type-III-procollagen and laminin concentration after interferon therapy in chronic myeloproliferative disorders.

Serum procollagen-III-peptide (P-III-P) and laminin P 1 (LP1) concentrations were measured in 24 patients with various chronic myeloproliferative diseases, viz., essential thrombocythaemia (ET), chronic myelogenous leukaemia (CML) and myelofibrosis (MF). The highest P-III-P values were found in myelofibrosis. As compared to the controls, the serum laminin concentration was higher in all there groups of patients. No significant difference was found between the groups of patients. After three months of alpha-IFN therapy the P-III-P values became significantly higher, the laminin concentration slightly decreased in all investigated patients. Longitudinal follow-up myeloproliferative patients should be carried out in order to prove whether P-III-P and laminin determinations provide a useful test to monitor the progression of the disease and the effect of the therapy.

Adult↗