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Biomedical subjects

H Senn

Publications and source records attributed to H Senn.

53 records · Page 3Linked to original sources
PubMed1980

Proliferation activity and bacteriostatic potential of human blood monocytes, macrophages in pleural effusions, ascites, and of alveolar macrophages.

Human blood monocytes, macrophages from pleural effusions, ascites, and alveolar macrophages obtained by bronchopulmonary lavage were investigated. The proliferative activity of these cells was determined by the 3H-thymidine labeling index in vitro (3H-TDR L.I.). The bacteriostatic capacity was measured by the potential of the cells to block DNA-synthesis of proliferating Escherichia coli after phagocytosis. In most cases 3H-TDR L.I. of blood monocytes, macrophages from pleural effusions and ascites was less than 1%. However, macrophages of some patients with neoplastic diseases exhibited 3H-TDR L.I. between 4.0--9.6%. This probably reflected the action of factors, possibly lymphokines, which stimulated macrophage proliferation. In contrast, alveolar macrophages seemed to have almost totally lost their proliferative potential. The bacteriostatic capacity of blood monocytes proved to be significantly lower than that of macrophages. This demonstrates the functional immaturity of blood monocytes. In all type of macrophages investigated the bacteriostatic power was very high. No differences could be detected either between macrophages of different sources or between macrophages of benign, inflammatory, or malignant diseases.

Ascites↗
PubMed1977

Determination of the bacteriostatic capacity of neutrophils and monocytes in mixed cell populations.

Cline [1, 2] described a method of determining the phagocytic and bacteriostatic activity of individual types of leukocytes within mixed cell populations. We tried to improve the applicability of this method for the investigation of clinical problems.--Bacteria in the log-phase of growth were incubated in test tubes with leukocytes separated from venous blood. After a short period of phagocytosis 3H-thymidine was added to label DNA-synthesizing organisms. Smears were prepared and processed by autoradiography. The labeling indices of extracellular bacteria and of those phagocytized by neutrophils and monocytes were determined microscopically. The intracellular inhibition of DNA-synthesis was taken as indicative of the bacteriostatic activity of the leukocytes. The proposed modification of Cline's assay is suited to investigate clinical problems of phagocyte dysfunction.

Autoradiography↗
PubMed1976

[Harvesting of granulocytes for granulocyte transfusion by means of continuous flow centrifugation or filtration leukapheresis].

More than 10(10) viable granulocytes are necessary for a therapeutical effective granulocyte transfusion. This number of cells can be harvested from normal donors by two techniques basing on different principles: continuous flow centrifugation (CFC) and filtration leucapheresis (FL). Our studies demonstrated that, under certain special conditions, the separation potentials of both methods are comparable yielding 2.5 to 3.0 X 10(10) granulocytes within 4 hrs. Granulocyte collection rate was optimal if donors were treated with dexamethasone during 16 hrs prior to the state of the procedure. However, the costs of CFC exceed those of FL by a factor of about two. The increased occurrence of side effects attributed to the transfusion of FL-granulocytes can be reduced to the level of CFC-granulocytes by repetitive filtration-elution leucapheresis minimizing cell damage. The studies define the efficiency spectrum of CFC which in addition to granulocyte separation includes collection of thrombocytes, cells for immunotherapy, and plasmapheresis.

Blood Transfusion↗
PubMedDate not supplied

Conformational studies of cyclic peptide structures in solution from 1H-Nmr data by distance geometry calculation and restrained energy minimization.

The three-dimensional structure of a cyclic bouvardin analogue, cyclo (-Pro-MeTyr-Ala-MeTyr-MeTyr-D-Ala-) has been determined by distance geometry calculation and restrained energy minimization from nmr data. The preparation of the input for the distance geometry calculations, the modification of the amino acid library, and the analysis of the structures were done with the aid of a recently developed software package, GEOM. A great variety of different initial structures were explored to check the uniqueness of the determined solution structure. Calculations with 500 different initial structures and two different strategies led to a uniquely determined backbone conformation with a root mean square deviations value of 0.4 A. The backbone structure consists of two beta-turns, a beta-II turn at Pro1-MeTyr2, and a beta-VI turn at MeTyr4-MeTyr5. The efficiency of the two calculation strategies were compared in order to propose an optimal means for performing distance geometry calculations with cyclic structures.

Amino Acid Sequence↗