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Biomedical subjects

H Rühl

Publications and source records attributed to H Rühl.

At least 55 records · Page 3Linked to original sources
PubMed1980

Stimulation of human and mouse lymphocytes by ribosomal proteins.

Ribosomal 30S and 50S subunits as well as total proteins from the large subunit of E. coli ribosomes were found to be potent mitogens for both human adult and cord blood lymphocytes. On the other hand, the RNA fraction of the 50S subunit had only a weak stimulatory capacity suggesting that the protein moiety contains the stimulatory component. Experiments with lymphocyte subpopulations obtained by nylon wool filtration of E-rosette separation have shown that, in human, the main target cells are T lymphocytes. First experiments with mouse spleen cells indicate that, in mice, T and B lymphocytes can be stimulated by ribosomal proteins.

Adult↗
PubMed1979

Activation of human lymphocyte subpopulations by protein A from Staphylococcus aureus bacteria.

Cowan I strain Staphylococcus aureus bacteria were found to be mitogenic for human peripheral and cord blood lymphocytes. Experiments with lymphocyte supopulations otained by nylon wool filtration and/or E-rosette separation revealed that T-lymphocytes are the main target cells, whereas isolated B cells did not respond significantly. Further experiments suggested that B cells could be activated in the presence of mitomycin-treated T cells. Null cell-enriched lymphocyte suspensions could be stimulated by Con A but not by the bacteria or by PHA.

B-Lymphocytes↗
PubMed1979

Zinc metabolism in normal, lectin-stimulated and leukemic lymphocytes.

Gel filtration of the cytoplasmic fraction of homogenate from human peripheral lymphocytes incubated with 65Zn gave five separate peaks with molecular weights of greater than 150,000, 90,000, 65,000, 20,000, and less than 1000 daltons. Peaks I--IV consisted of proteins. The low molecular weight (peak V) may consist of nucleotides, polyamines and amino acids. After gel filtration 75-80% of the 65Zn activity was found in peak V. Lectin-induced stimulation of normal lymphocytes revealed a distribution pattern of 65Zn binding similar to that of unstimulated cells. There was only a slightly enhanced incorporation into the protein peaks I--IV. When peripheral lymphocytes of B lymphocyte origin from patients with chronic lymphocytic leukemia were incubated with 65Zn the same peaks were seen as with supernatants obtained from normal lymphocytes. Lectin-induced stimulation of leukemic lymphocytes had no significant effect on the 65Zn distribution pattern.

Carrier Proteins↗
PubMed1978

Activation of lymphocyte subpopulations in patients with chronic lymphocytic leukemia.

T lymphocytes from the peripheral blood of normal donors and patients with CLL were isolated by nylon wool filtration or E-rosette separation and tested for functional activities. Unseparated CLL lymphocytes showed a poor response to phytomitogens and to allogeneic cells. Subpopulations enriched in E-RFC showed an increased PHA- and a normal MLC-reactivity; the Con A responses, however, were markedly reduced in all experiments. Subpopulations which were T cell depleted showed no reactivity to all mitogens. Purified T cells from normal donors showed a decreased reactivity to PHA, Con A and PWM. The Con A responses were completely abolished in almost all experiments. These diminished responses could be restored by unseparated cells or by small numbers of syngeneic, mitomycin-treated monocytes. The data suggest that mitogen-induced T lymphocyte stimulation in vitro in general depends on the presence of monocytes.

Antibody-Producing Cells↗
PubMed1978

Monocyte-dependent stimulation of human T cells by zinc.

Subpopulations of human peripheral blood leucocytes were isolated by nylon filtration or E-rosette separation and tested for functional activity. As shown previously, zinc ions induce DNA synthesis in unfractionated lymphocyte cultures. E-rosette-forming cells (E-RFC), obtained either by nylon wool filtration or E-rosette separation, responded well to PHA but showed only low levels of proliferative reactivity to zinc and Con A. These dminished responses could be completely restored by the addition of small numbers of autologous, mitomycin-treated monocytes; further experiments suggested that a monocyte-derived soluble factor can substitute for monocytes in this function. B lymphocyte-enriched cell populations, containing less than 1% E-RFC, did not respond to zinc and showed only marginal reactivity to PHA and Con A.

Concanavalin A↗
PubMed1977

Effect of A. laidlawii on murine and human lymphocyte cultures.

Heat-inactivated A. laidlawii (AL) was found to be a potent mitogen for mouse spleen cells. Spleen cells from homozygous nude mice and spleen cells treated with anti-theta serum and complement responded as well as their respective controls, indicating that AL represented a B-cell mitogen for mouse spleen cells. Spleen cells from LPS-unresponsive C3H/Hej mice responded well to AL. The peripheral blood leucocytes from unselected human donors were also stimulated by AL, which appeared to represent a T-cell mitogen for human leucocytes. However, the possibility that it acted as a specific antigen could not be excluded. Attention was drawn to the possibility that the presence of mycoplasma might considerably affect the results of tests where tissue-culture cells or derivatives thereof are added to leucocyte cultures.

Acholeplasma laidlawii↗
PubMed1976

[A contribution to the physiology of movement of gregarines: elements and modus of cellular movement (author's transl)].

1. Cytochalasin B (= CCB, Phomin) in several concentrations inhibits the visible movement of gregarines. The fine structure of the cell is simultaneously changed, fibrillar bundles are desorganized. These fibrils are regarded as myonemes. 2. These myonemes are directed peripherally of the cell longitudinal and transverse to its axis. The longitudinal myonemes are organized in separated strings stretching along the top of the epicyte folds, between the plasmalemm and the secondary membranous layer. Fibrils under this layer serve as skeleton and as thus antagonist. The skeleton fibrils remain unaltered after CCB inhibition. They are located in a parallel direction to the myonemes. Their number corresponds together in one epicyte fold. The transverse myonemata surround the central plasma nearby the basal lamella, which cannot be found in some of the regarded species. 3. The co-work of skeleton-fibrils, stiff pellicle and myonemes allows to describe the modus of all known types of movement. Only change of coordination yields the multitude of these kinds of movement.

Animals↗
PubMed1975

Mixed lymphocyte culture stimulatory and responding capacity of lymphocytes from patients with lymphoproliferative diseases.

Lymphocyte reactivity in vitro was studied in patients with Hodgkin's disease, chronic lymphocytic leukaemia and lymphosarcoma. The responding capacity to phytohaemagglutinin (PHA) was markedly depressed and delayed in all three groups of patients compared with the PHA response observed in lymphocyte cultures from normal individuals. In one-way mixed lymphocyte culture experiments a significant decrease in responding capacity of the patients' lymphocytes to lymphocytes from normal donors could be demonstrated. In contrast, the stimulatory capacity of the patients' lymphocytes was found to be intact, or only slightly reduced.

Adolescent↗
PubMed1973

Zinc deficiency.

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Animals↗