Ex vivo neutrophil function in response to three different doses of glycosylated rHuG-CSF (Lenograstim)

Granulocyte colony-stimulating factor (G-CSF) is being considered as adjuvant treatment for infections in non-neutropenic patients. Normal healthy donors were given rHuG-CSF (Lenograstim) at 2.5, 5.0 and 7.5 μg/kg subcutaneously daily for 5 d. Polymorphonuclear leucocyte (PMN) function tests were carried out on peripheral blood PMN before the first injection and at 24 h and 96 h. Circulating PMN levels were also measured at these time intervals and found to be significantly increased with all doses by 24 and 96 h. Investigation of cell surface antigen expression revealed no changes in β₂ integrin (CD11b/CD18) expression. L-selectin (CD62L) expression was reduced with all doses by 96 h, this being significant with the 7.5 μg/kg dose. FcγRI (CD64) levels were significantly up-regulated with the 7.5 μg/kg dose by 96 h whereas FcγRIII (CD16) expression was found to be reduced during G-CSF treatment. Superoxide anion production was significantly increased in response to N -formylmethionylleucylphenylalanine (FMLP) and opsonized Staphylococcus epidermidis stimulation at 24 h and 96 h with the 5.0 and 7.5 μg/kg doses. The initial rate of phagocytosis (0–2 min) appeared to have increased with the 7.5 and 5.0 μg/kg doses at 96 and 24 h compared with PMN responses pretreatment, although these increases were not statistically significant. These results show that G-CSF enhances the functional responses of PMN stimulated by physiological agonists and may help in the treatment of infections.     

A solitary plasmacytoma of donor origin arising 14 years after kidney allotransplantation

Summary Allotransplantation of solid organs transfers passenger leucocytes which may give rise to a state of persistent microchimaerism. In this report we describe the case of a patient who developed a solitary plasmacytoma in a transplanted kidney more than 10 years after allografting. The diagnosis was established on the basis of the presence of a monoclonal IgG kappa peak in the serum, and light chain proteinuria, the plasmacytoid features of tumour cells including cell surface expression of IgG, kappa light chains, CD20, CD38 and CD56, the absence of lytic bone lesions and a normal bone marrow biopsy, and the disappearance of the monoclonal IgG peak after graft nephrectomy. A donor origin of the tumour was established by HLA DNA typing of tumour, tumour-free kidney tissue, and peripheral blood leucocytes, respectively.     

Plasminogen activator is involved in the hCG-induced neutrophil extravasation and vasopermeability increase in the rat testis

The role of proteolytic enzymes in the hCG-induced increase in testicular vasopermeability and neutrophil extravasation was studied using protease inhibitors. An intra-testicular injection of hCG together with incubation medium conditioned by polymorphonuclear leucocytes (PMNs) caused a significant increase in vasopermeability and a coincident extravasation of PMN's from the postcapillary venules in the rat testis. When p-aminobenzamidine, a serine protease inhibitor which inhibits urokinase-type plasminogen activator, was administered together with hCG in the incubation medium, both the permeability increase and PMN extravasation were prevented. Aprotinin, another serine protease inhibitor, and Eglin C, a specific neutrophil elastase and cathepsin G inhibitor were, however, without effect. None of these inhibitors caused any non-specific vascular effects in the testis at the concentrations used. These results support the concept that the hCG-induced increase in vasopermeability in the rat testis is related to extravasation of PMNs and suggest that urokinase-type plasminogen activator is involved in migration of these cells through the postcapillary venular walls.     

Seminal peroxidase positive cells are not an adequate indicator of asymptomatic urethral genital infection

The relationship between asymptomatic urethral infection and seminal white blood cells, as detected using the peroxidase enzyme system, was examined. Eighty-four semen donors were tested. Twenty-four (29%) were diagnosed as having an active urethral genital infection. There was no statistical relationship between the total number of concentrations of peroxidase-positive cells and a urethral genital infection. Further studies should concentrate on the subtypes of seminal leucocytes and their surface receptors using monoclonal antibodies.     

Diving physiology and pathophysiology

Summary. Divers have worked at 500 m depth in the sea and have reached 700 m in simulated chamber dives. A prerequisite for this has been extensive physiological studies of the body's reactions to pressure and pressure changes. This paper reviews such physiological and pathophysiological studies with emphasis on recent developments.     

Blockade of superoxide generation prevents high-affinity immunoglobulin E receptor-mediated release of allergic mediators by rat mast cell line and human basophils

BACKGROUND: Previous studies have shown that rat peritoneal mast cells and mast cell model rat basophilic leukaemia (RBL-2H3) cells generate intracellular reactive oxygen species (ROS) in response to antigen challenge. However, the physiological significance of the burst of ROS is poorly understood. OBJECTIVE: The present study was undertaken to investigate the role of superoxide anion in mediator release in rat and human cell systems. METHODS: RBL-2H3 cells were directly stimulated with anti-rat FcepsilonRI alpha-subunit monoclonal antibody (mAb). For the analysis of human cell system, leucocytes were isolated by dextran sedimentation from healthy volunteers or from patients, and challenged either with anti-human FcepsilonRI mAb or with the relevant antigens. Superoxide generation was determined by chemiluminescence-based methods. The releases of histamine and leukotrienes (LT)s were determined by enzyme-linked immunosorben assay (ELISA). RESULTS: Cross-linking of FcepsilonRI on RBL-2H3 cells or on human leucocytes from healthy donors by the anti-FcepsilonRI mAb resulted in a rapid generation of superoxide anion, as determined by chemiluminescence using superoxide-specific probes. Similarly, leucocytes from patients generated superoxide anion in response to the challenge with the relevant allergen but not with the irrelevant allergen. Furthermore, diphenyleneiodonium (DPI), a well-known inhibitor of flavoenzymes suppressed the superoxide generation and the release of histamine and LTC4 induced by the anti-FcepsilonRI mAb or by allergen in parallel. CONCLUSION: These results indicate that both RBL-2H3 cells and human basophils generate superoxide anion upon FcepsilonRI cross-linking either by antibody or by allergen challenge and that blockade of the generation prevents the release of allergic mediators. The findings strongly support the role of superoxide generation in the activation of mast cells and basophils under both physiological and pathological conditions. The findings suggest that drugs regulating the superoxide generation have potential therapeutic use for allergic disorders.     

Significance of eosinophilic granulocytes in chronic subdural hematomas

Despite a number of studies on infiltration of eosinophilic granulocytes into the outer membrane of chronic subdural hematomas, the significance of this phenomenon is not clear. We investigated histologically the membranes of 40 patients with chronic subdural encapsulated hematoma. Infiltrations with eosinophilic leucocytes were found in the granulation tissue of the inner layer of the outer membrane, either diffuse and sporadic (12 cases) or as massive agglomerations (28 cases). Fifty percent of the patients with marked infiltrations were between 61 and 80 years old. In 5 cases Charcot-Leyden crystals were identified. The numerous functions of the eosinophils play a more important role in repair than in maintenance of fluidity of hematomas.     

Association of passive smoking with increased coronary heart disease risk is not explained by elevation of leucocyte count

The increased risk of coronary heart disease in cigarette smokersmay be due at least partly to an elevation of the leucocytecount Chronic passive smoking has also been found to be associatedwith an increased risk of coronary heart disease, but its effecton the leucocyte count has not been reported. In this study250 male factory employees aged 20–64 years were interviewedon smoking behaviour and exposure to environmental tobacco smoke,and blood counts were determined. Urinary cotinine was measureby radio-immunoassay and corrected for urinary creatinine concentrations.Mean leucocyte count was significantly higher among smokerscompared with non-smokers (8,666 compared to 6, 900; p<0.001).On the basis of smoking history, passive smokers had leucocytecounts similar to non-smokers. These findings were confirmedwhen leucocyte counts were compared with urine cotinine to creatinineratios. The association of haematocrlt and haemoglobin withsmoking was similar to that of leucocyte count These findingssuggest that any association of passive smoking with coronaryheart disease is not through an elevation of leucocyte count.     

An in vitro study of polymorphonuclear leucocyte-mediated injury to human gingival keratinocytes by periodontopathic bacterial extracts

Human gingival keratinocytes were cultured and, after the first passage, subjected to cell detachment assays with polymorphonuclear leucocytes (PMNs) and/or sonic extracts from Actinobacillus actinomycetemcomitans Y4, and Eikenella corrodens 1073. The effector-to-target cell ratio was 30:1. Bacterial extracts alone caused no disruption of keratinocyte monolayers. PMNs alone also caused only minimal detachment after 14 h incubation. Adding A. actinomycetemcomitans to the PMN-keratinocyte co-cultures at the concentration of 100 μg/ml caused dramatic cell detachment. The effect of A. actinomycetemcomitans was heat labile and not inhibited by polymyxin B. Cell detachment was inhibited by α₁-antitrypsin, whereas catalase and Superoxide dismutase could not prevent it. No lysis of keratinocytes was observed after incubation, as judged by ⁵¹Cr release. E. corrodens had little effect even at the concentration of 1000 μg/ml. H₂O₂ and partially purified PMN elastase also caused detachment of keratinocytes. These data indicate that PMNs can cause non-lytic detachment of keratinocytes when interacting with certain bacteria.