Luminol-dependent luminescence (LDL) and luminol-independent, native luminescence (NL) of polymorphonuclear leukocytes were investigated with respect to the effects generated by the addition of albumin to the reaction medium. The cells were activated: (1) by simple surface attachment to a hydrophilic plastic, (2) by opsonized zymosan, (3) by phorbol myristate acetate, (4) by formylmethionyl-leucyl-phenylalaline. Both kinds of emissions were recorded simultaneously using a method of spectral discrimination. The addition of albumin resulted in an inhibition of LDL, which coincided with a generation of NL. The extent of the inhibition of LDL depended on the type of stimulus used. Maximum inhibition occurred with cells activated by attachment to plastic surfaces and minimum inhibition was observed with cells stimulated by opsonized zymosan. Different contributions of extracellularly released reactive oxygen-species may be responsible for this. It appears possible to discriminate between intra- and extracellular sites of oxygen-metabolites production using albumin simultaneously as extracellular quencher of LDL and as luminescent probe for NL.

Humans↗

PubMedDate not supplied

Magnesium-dependent induction of phagocytosis-associated chemiluminescence of adherent human polymorphonuclear leukocytes by non-opsonized zymosan.

A severe dysfunction in the cellular response of human polymorphonuclear leukocytes (PMNL) to non-opsonized zymosan was observed under a deficiency of extracellular Mg2+. The phagocytosis-association native (luminol-independent) luminescence (NL), as well as luminol-dependent luminescence (LDL) (detected simultaneously and discriminated by spectral methods), was strongly inhibited. Apart from a general decrease of total light production, a Mg2+-concentration-dependent delay of the maximum of NL and LDL was observed. A disorder in recruitment of activated membrane-bound NADPH-oxidase of PMNL is suggested. The presence of extracellular Ca2+ did not compensate for the Mg2+ deficit. In the presence of Mg2+ only a slight Ca2+-dependent reduction of NL was obtained, but Ca2+ seemed to selectively promote LDL. This may indicate a positive influence of Ca2+ on the myeloperoxidase release from the cells. Experiments with the metalions-chelating agents EDTA and EGTA, which complex Mg2+ to differing extents, confirmed the important role of Mg2+ in PMNL-activation by non-opsonized zymosan.

Calcium↗

PubMedDate not supplied

Different influences of cytochalasin B on the activation of human neurophils settled onto petri dishes displayed by simultaneously detected native and luminol-dependent luminescence.

Cytochalasin B (CB) is known to interfere reversibly with the cytoplasmic contractile filamental network of mammalian cells. The role of the microfilament system in the mechanism of the reactive oxygen intermediates release of polymorphonuclear leukocytes (PMNL) was studied for different kinds of stimuli. PMNL from fresh human blood were treated with CB and stimulated by adherence on plastic surfaces, by opsonized zymosan, by phorbol myristate acetate and by N-formylmethionyl-phenylalaline. The production of reactive oxygen species were monitored by simultaneous detection of native, luminol-independent, luminescence (NL) and luminol-dependent luminescence (LDL) using a method of spectral discrimination. Different influences of CB on NL with respect to LDL as well stimuli-dependent influences of CB on the luminescence response of PMNL were observed. Especially phagocytosis-associated activation of PMNL was strongly inhibited by CB, whereas LDL was reduced to a much greater extent in comparison with NL. A firm involvement of the microfilament system is indicated, but it depends on the kind of stimulus engaged.

Actin Cytoskeleton↗

PubMedDate not supplied

[Osteochondritis dissecans of the knee joint. Results of follow-up].

In a long-term follow-up examination (5-15 years postoperatively) clinical and radiological results after surgical treatment of osteochondritis dissecans of the knee of 97 patients with 109 osteochondritic lesions were controlled. The treatment consisted of retrograde removal of the subchondral osteonecrosis and -sclerosis with following autologous bone grafting in cases with intact hyaline cartilage. In cases of partial or total loosening of the osteochondritic lesion this procedure was done anterograde. For refixation different techniques such as fibrin glue or acylate glue were used. Using the classification of Arcq in 59.6% of the knee joints excellent and in 18.3% good results were obtained. Regarding the development of osteoarthritis in 56% no signs of osteoarthritis were visible. Worst results were obtained in knee joints in which non-resorbable acrylate glue was used for refixation of dissecates. In contrast to that patients in which loose dissecates were refixated with fibrin glue reached a significant better postoperative long-term result. In addition postoperative results were influenced by the age in which first symptoms were complained, by the stage of cartilaginous lesion, the kind of intraoperative technique and by additional morphological disturbances at the knee such as varus- or valgus mallaignment. In general for the treatment of osteochondritis dissecans of the knee an early operation before occurrence of cartilaginous lesions is recommended to avoid osteoarthritic changes. In cases of partial or complete loosening fibrin glue is recommended as the fixation technique of first choice.

Adolescent↗