Biomedical subjects
Publications and source records attributed to C Jarstrand.
Clostridium difficile cytotoxin caused an irreversible dose- and time-dependent loss of fibronectin from the surfaces of human lung fibroblasts, paralleling the appearance of the cytopathic effect. Fibronectin was not required for the intoxication process. The results lend further support to a transmembrane connective link between fibronectin and the microfilaments.
A procedure for visualizing and quantifying motility of Entamoeba histolytica by migration under agarose is described. Agarose suspended in tissue culture medium 199 supplemented with bovine albumin was poured into plastic dishes and allowed to harden. Six pairs of wells were cut out in a circular configuration. To the inner wells a suspension of E. histolytica in Eagle's Medium (24 X 10(6) cells/ml) was added, and to the outer wells a chemoattractant or the control medium. After overnight incubation at 37 degrees C, the amebae were fixed and stained. The chemotactic and spontaneous migrations were measured in an enlarging projector. Escherichia coli filtrates, suspensions of intact and lysed erythrocytes, and the complement factor C5a acted as good chemoattractants. Both the random and chemotactic motility were correlated to the time of the incubation. Cytochalasin B effected a dose-related inhibition of both chemotactic and random migration, while colchicine caused a decrease of the chemotaxis only. The reproducibility of the method, measured by 10 intra-assay tests, was good. Thus, the described method can be useful for comparative determinations of the motility of different ameba populations. Furthermore, different factors affecting the motility of amebae can be studied.
Different plasma lipoprotein fractions in physiological concentrations have opposite effects on the phagocytosis and migration of human neutrophilic granulocytes. Preincubation for half an hour with very low density lipoproteins decreased the phagocytosis as well as the chemotactic and random migrations of the cells, while preincubation with high density lipoproteins increased the same functions. No effects were seen with low density lipoproteins. It is suggested that disturbances in plasma lipoprotein pattern may affect the function of phagocytes.
The influence of daily intramuscular injections of 3 X 10(6) units of interferon-alpha (IFN-alpha) on the phagocytic activity of peripheral monocytes was studied in 28 tumor patients. One day after initiation of IFN therapy no major change in the capacity of monocytes to ingest yeast particles was observed. After 1 week, 3 months, 6 months, and 9 months of treatment, monocyte phagocytosis had decreased in the majority of the patients tested. In patients where natural killer (NK) cell activity was measured simultaneously with monocyte phagocytosis, a correlation between the degree of enhancement of NK activity and the degree of decrease in monocyte phagocytosis was observed.
Radiation treatment of breast cancer patients (45.0 Gy) profoundly affected the peripheral blood lymphocytes. The number of these cells was markedly reduced with non-T-cells being more extensively depleted than T-cells immediately after radiation. The long-lasting lymphopenia, on the other hand, was mainly due to reduced number of T-cells. Antigen and mitogen stimulability, MLC reactivity, pokeweed (PWM)-induced immunoglobulin (Ig) production in vitro, and different cytotoxic functions decreased. Depletion of lymphocytes largely restored the radiation-depressed lymphocyte reactivity. The effects of in vitro exposure of blood lymphocytes to x-rays were similar to those seen after radiotherapy. Non-T-cells and T-cells with Fc-receptors for IgG were relatively radiosensitive. This latter observation agreed well with demonstrated increase of PWM-induced Ig synthesis after in vitro exposure to x-rays. T-suppressor cells defined by monoclonal antibodies were, however, radioresistant. The cytotoxic functions were reduced. No correlations were found between the pretreatment immunological status or the extent of radiation-induced immunological suppression, respectively, and prognosis.
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The phagocytic and catabolic functions of the reticuloendothelial system (RES) were determined in ten healthy men after subcutaneous injection of low-dose sodium- or calcium-heparin. The nitroblue tetrazolium (NBT)-reducing and the bactericidal capacity of granulocytes isolated from the men after heparin administration were also measured. No statistically significant difference was found for the two salts of heparin in any of the mentioned respects as compared with control injections of physiologic saline solution. In addition to these in vivo investigations, in vitro experiments were made for further study of the influence of sodium-heparin on various granulocyte functions. The results showed slight, but statistically significant increase in attachment and engulfment of particles when granulocytes were pre-incubated with heparin. No significant effect of heparin was detected in vitro on the chemotactic and random migration of granulocytes in tests with heparin concentrations 10 and 100 IU/ml. Preincubation of granulocytes with heparin in the same concentrations, however, resulted in a statistically significant decrease in the bactericidal capacity of the cells.
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Neutrophilic granulocytes preincubated in vitro with human plasma fibronectin (0-1.25 mg/ml) for 30 minutes showed increased spontaneous and chemotactic migration, increased uptake of fluorescein labelled yeast particles as well as higher NBT-reduction both with and without E. coli stimulation. These effects on the granulocyte functions were found to be mainly dose dependent. In control experiments, no significant effects were noted when fibronectin was replaced by human serum albumin in the same concentration range.
Bestatin, which is a chemically well-defined immunomodulator, was examined for its possible influence on various monocyte functions. It was observed that pretreatment of separated human blood monocytes with Bestatin did not change their chemotactic or random migration. In addition, the capacity of monocytes to reduce nitroblue tetrazolium or to inhibit growth of Chang cells was unchanged by Bestatin. Phagocytosis of yeast particles, however, was increased by pretreatment of monocytes with Bestatin in vitro and it was observed that oral administration of Bestatin to cancer patients augmented the phagocytic activity of blood monocytes in vitro.
Alveolar macrophages from 9 normal rabbits were incubated in vitro for 3 h with and without phospholipid-containing surfactant from nickel-treated ones. The macrophages treated with surfactant showed morphological and functional criteria of increased activity. The cell surface had many protrusions and the cytoplasma contained several lamellated structures. The oxidative metabolism, measured by the nitroblue tetrazolium (NBT)-test, at rest and after E. coli stimulation was increased, as was the attachment and ingestion of yeast particles. The NBT-values were about the same as corresponding values of macrophages lavaged from the lungs of nickel-treated rabbit. Macrophages incubated with surfactant from untreated animals, had NBT values and phagocytic activity similar to cells incubated without surfactant. As this substance was administered in excess, the difference in macrophage response would probably be due to a qualitative alteration of the surfactant after nickel exposure.
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Bestatin, which is a chemically well-defined immunomodulator, was tested for its capacity to change certain functions of human granulocytes from healthy donors in vitro. Pretreatment of granulocytes with Bestatin enhanced their spontaneous migration as well as their migration in the presence of chemotactic stimuli. Moreover, Bestatin treatment augmented the ingestion of yeast particles but it did not change the oxidative metabolism of the cells as measured by their capacity to reduce nitroblue tetrazolium.
The NBT reduction of granulocytes, increased in the presence of bacteria, was further enhanced bl specific antibody. The enhancement was dose-dependent and increased by complement. Clinically, the NBT test was used for measuring specific antibody in sera from patients after severe infections. With sera from 10 out of 14 patients with proven or suspected septicemia the NBT reduction was enhanced because of the presence of specific antibody. These results correlated well with the bacteriological findings and supported the view that the bacteria isolated from blood were relevant for the disease.
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Four different functions of the immune defence were studied in six men undergoing open-heart surgery with cardiopulmonary bypass (CPB). Pre-operatively, a few hours after and three days after surgery the following tests were performed: (I) in vivo phagocytic and metabolic functions of the reticuloendothelial system (RES), (II) haemolytic activity of blood monocytes, (III) nitroblue tetrazolium (NBT) reduction by granulocytes, and (IV) bactericidal capacity of granulocytes. Compared to the pre-operative values, the RES functions were unchanged postoperatively, whereas there was a significant increase in the haemolytic activity of monocytes and in the NBT reduction of granulocytes. The capacity of the granulocytes to kill bacteria was normal a few hours after surgery, but significantly increased on day 3. No infectious complications occurred and all patients recovered uneventfully. These results suggest that, at the present time, open-heart surgery under CPB is accompanied by an increased activity of granulocytes and monocytes in the early postoperative period.