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Biomedical subjects

R Van Furth

Publications and source records attributed to R Van Furth.

At least 37 records · Page 2Linked to original sources
PubMed1990

Increased activity of FIM in serum of mice during a Mycobacterium bovis (BCG) infection.

In mice given an intravenous injection of Mycobacterium bovis (BCG), the bacilli proliferated in the spleen, liver and lungs but the peritoneal cavity remained sterile. The numbers of blood monocytes and alveolar macrophages were increased during the first 2 weeks of the infection, whereas the number of peritoneal macrophages remained constant. To study whether factor-increasing monocytopoiesis (FIM) plays a role in the regulation of the monocytosis during the BCG infection, the activity of this factor in the serum of mice at various intervals during the infection was determined. Previous studies have shown that FIM stimulates monocyte production by its effect on the mitotic activity of monoblasts and promonocytes in the bone marrow. The FIM activity of the serum reached a maximum on Day 4 and remained elevated during the first 21 days of the BCG infection. Since FIM is synthesized and secreted by macrophages that have phagocytosed opsonized particles, it is highly probable that FIM occurring in serum originates from macrophages that have ingested BCG. The results of the present study led to the conclusion that FIM plays a role in the monocytosis developing during infection with BCG.

Animals↗
PubMed1988

Immunocytochemical detection of 5-bromo-2-deoxyuridine incorporation in individual cells.

5-Bromo-2-deoxyuridine (BrdUrd) is a thymidine analogue which can be used to detect DNA synthesis in cells. The present paper describes a method for the fixation and DNA denaturation of cells that affects neither the morphology of the cells not their adhesion to a glass surface. The cells were fixed in absolute ethanol and glacial acetic acid followed by gradual rehydration. Denaturation of DNA was achieved by very brief exposure of the cells to low pH, followed by heating to high temperature and rapid cooling. Incorporation of BrdUrd was assessed from the binding of monoclonal antibody to BrdUrd in single-stranded DNA as detected with an immunocytochemical method. This method makes it possible to demonstrate BrdUrd labeling of individual, morphologically identifiable cells. The results obtained with this method correspond well with the autoradiographic data on [3H]thymidine incorporation.

Animals↗
PubMed1986

A reaction vessel for the measurement of oxygen consumption by small numbers of cells in suspension.

A reaction vessel is described that permits measurement of oxygen consumption in small numbers of cells in suspension. The assay permits accurate detection of changes in oxygen tension amounting to less than 0.016 nmol X min-1, and allows the continuous monitoring and calculation of oxygen consumption by as few as 3-6 X 10(5) blood granulocytes or mouse peritoneal macrophages. The results obtained with this assay are highly reproducible, and the values agree closely with those obtained in 10-15-fold larger samples with commercially available oxygraphs. The reaction vessel offers three basic advantages: (1) fewer cells are required per sample (at most 1/10 the number needed for conventional oxygraphs); (2) smaller volumes of test media are needed (i.e., cytokines, opsonins); and (3) the oxygen tension of the medium can be rapidly changed to any desired level at the start of or during experiments. The applications described include the oxygen consumption by human granulocytes and murine peritoneal macrophages before and after addition of both soluble and particulate stimuli. With the use of this technique it was found that the maximum oxygen consumption by human granulocytes after stimulation with phorbol myristate acetate is proportional to the oxygen tension of the medium during the addition of the triggering agent.

Animals↗
PubMed1985

Method to select mice in the steady state for biological studies.

Collection of small amounts of blood from the orbital sinus was found to be a satisfactory method for repeated sampling in mice, which means that these animals can be selected for further study on the basis of the leukocyte count. In biomedical research it is often necessary to have detailed information about the effect of injected material on the numerical course of circulating leukocytes. However, the present study has shown that 2 stress-producing procedures on 1 day disturb the steady state, and that this disturbance is expressed in changes in the number of leukocytes. Such stress could be avoided by alteration of the experimental design to include only 1 stressful situation each day. When blood was sampled in the orbital sinus on 1 day to determine the animals' condition and on the next day only the tail was punctured as sham injection, the number of blood leukocytes remained constant throughout the observation period. Comparative studies on the numbers of monocytes, lymphocytes, and granulocytes in blood from the tail, heart, and orbital sinus showed a systematic difference in the mean numbers of certain types of leukocytes. Statistically significant differences were found between the mean numbers of monocytes, lymphocytes, and granulocytes in orbital blood from normal mice of 5 specific pathogen-free strains, i.e., Cpb:SE (Swiss), CBA/Cpb, BALB/cCpb, C3H/Rij, and DBA/2Rij.

Animals↗
PubMed1985

A cytophotometric method to quantitate the binding of monoclonal antibodies to individual cells.

A cytophotometric technique to quantitate binding of (monoclonal) antibodies to individual cells is described. This method is based on the detection of cell-surface antigens by immunoperoxidase staining procedures. The amount of reaction product of the peroxidase reaction with diaminobenzidine/H2O2 was quantitated by computerized scanning cytophotometry. The incubation period of peroxidase with the substrate required for an optimal cytophotometric determination of the reaction product proved to be 60 min. The reproducibility of individual absorbance measurements, the day-to-day reproducibility of the quantitation of monoclonal antibody binding, and the specificity and sensitivity of the detection of defined monoclonal antibodies, established the reliability of the present method. The sensitivity of the indirect immunoperoxidase procedure could be enhanced by using a biotin-avidin-peroxidase staining procedure.

Animals↗
PubMed1984

Determination of blood volume in the mouse with 51chromium-labelled erythrocytes.

The present report concerns the use of 51chromium-labelled erythrocytes to measure the blood volume of mice. Statistical analysis showed a linear correlation between blood volume and body weight for male and female Swiss mice and female B10 mice; for female CBA mice the relation was curvilinear. The mean blood volumes of these mice, expressed per 100 g body weight, amounted to 7.14 ml for male Swiss mice, 7.17 ml for Swiss females, 6.96 ml for B10 females, and 6.29 ml for CBA females. The difference in blood volume between the CBA strain and the other mouse strains is statistically significant.

Animals↗
PubMed1983

Micro-CO2-incubator for use on a microscope.

A simple micro-CO2-incubator designed for use on the stage of an inverted microscope is described. This micro-incubator is easy to use, offers a handy tool for the culture of cells under the microscope and its performance compares well with that of a conventional CO2-incubator. A standard disposable culture dish can be placed in the micro-incubator. The culture medium is covered by a gas-permeable layer of mineral oil, this protects the culture from the environment without affecting the culture conditions and allows easy cell manipulation under microscopical control.

Animals↗
PubMed1983

A micromethod for the separate evaluation of phagocytosis and intracellular killing of Staphylococcus aureus by human monocytes and granulocytes.

A micro-assay has been developed for the separate evaluation of phagocytosis and intracellular killing of Staphylococcus aureus by human monocytes and granulocytes. The minimal number of phagocytes required for the investigation of these functional activities of phagocytic cells has been established by performing phagocytosis and intracellular killing experiments at various cell concentrations, bacteria-to-cell ratios, and volumes. The results of these experiments revealed that phagocytosis can be measured in a reliable way, at bacteria-to-cell ratios of 5:1 and 1:1 (cell concentration 5 x 10(6)/ml), in a suspension of 200 microliters. The rate of intracellular killing by monocytes and granulocytes can also be measured with a total phagocytic suspension of 200 microliters and a cell concentration of 5 x 10(6)/ml. From these results it can be concluded that for an independent determination of the phagocytosis and intracellular killing of micro-organisms, 400 microliters of 5 x 10(6) phagocytes/ml is required, i.e., a total of 2 x 10(6) phagocytes. This number of granulocytes can be obtained from 1-2 ml of blood; for monocytes 4-8 ml of blood is required.

Blood Bactericidal Activity↗
PubMed1983

Estimation of the membrane potential of cultured macrophages from the fast potential transient upon microelectrode entry.

Analysis of membrane potential recordings upon microelectrode impalement of four types of macrophages (cell lines P388D1 and PU5-1.8, cultured mouse peritoneal macrophages, and cultured human monocytes) reveals that these cells have membrane potentials at least two times more negative than sustained potential values (E(s)) frequently reported. Upon microelectrode entry into the cell (P388D1), the recorded potential drops to a peak value (E(p)) (mean -37 mV for 50 cells, range -15 to -70 mV) within 2 ms, after which it decays to a depolarized potential (E(n)) (mean -12 mV) in about 20 ms. Thereafter, the membrane develops one or a series of slow hyperpolarizations before a final sustained membrane potential (E(s)) (mean -14 mV, range -5 to -40) is established. The mean value of the peak of the first hyperpolarization (E(h)) is -30 mV (range -10 to -55 mV). The initial fast peak transient, measured upon microelectrode entry, was first described and analyzed by Lassen et al. (Lassen, U.V., A.M. T. Nielson, L. Pape, and L. O. Simonsen, 1971, J. Membr. Biol. 6:269-288 for other change in the membrane potential from its real value before impalement to a sustained depolarized value. This was shown to be true for macrophages by two-electrode impalements of single cells. Values of E(p), E(n), E(h), E(s), and membrane resistance (R(m)) measured for the other macrophages were similar to those of P388D1. From these results we conclude that E(p) is a better estimate of the true membrane potential of macrophages than E(s), and that the slow hyperpolarizations upon impalement should be regarded as transient repolarizations back to the original membrane potentials. Thus, analysis of the initial fast impalement transient can be a valuable aid in the estimation of the membrane potential of various sorts of small isolated cells by microelectrodes.

Animals↗
PubMed1982

Characterization of mononuclear phagocytes from the mouse, guinea pig, rat, and man.

The present paper describes cytochemical, membrane, functional, and mitotic characteristics of monoblasts, promonocytes, monocytes, and macrophages of the mouse, guinea pig, rat, and man. For all of these species the results show that after staining for nonspecific esterase, with alpha-naphthylbutyrate as substrate, and for lysozyme, mononuclear phagocytes can be distinguished from other cells, e.g., T and B lymphocytes. However, it must be kept in mind that immature and mature granulocytic cells are also lysozyme positive. The presence of Fc and C receptors is dependent on the maturity of the cells and the duration of incubation in vitro; with respect to the former, an in vivo population of immature mononuclear phagocytes may have a lower percentage of positive cells than is the case in a mature population, and with respect to the latter, the percentage of positive cells rises during incubation. Phagocytosis of opsonized bacteria and red cells is a reliable criterion for the distinction between mononuclear phagocytes and other cell types, e.g. lymphocytes and fibroblasts. In all of the species studied, the majority of both immature and mature mononuclear phagocytes ingested particles opsonized with IgG; the proportion of phagocytosis of red cells via C3 receptors is usually very small. Incorporation studies with [3H] thymidine have shown that immature mononuclear phagocytes (i.e., monoblasts and promonocytes) divided and that monocytes and macrophages do not. The small number of macrophages that incorporate [3H] thymidine are immature mononuclear phagocytes which have very recently arrived in the tissues from the bone marrow. Comparison of mononuclear phagocytes in different organs of various species has shown unequivocally that these cells belong to one cell line, called the mononuclear phagocyte system.

Animals↗
PubMed1982

Functions of peripheral-blood monocytes and granulocytes in cutaneous T-cell lymphoma.

Granulocyte and monocyte functions (phagocytosis, intracellular killing, chemokinesis and chemotaxis) and the opsonic and chemotactic activity of the serum of twenty-two patients with cutaneous T-cell lymphoma were assessed. Granulocyte functions were within the normal control range in most cases. The monocyte functions showed more variation in the test results; in six out of twenty-two patients intracellular killing of Staphylococcus aureus was depressed and in four out of ten patients a disturbance in monocyte chemotaxis was found. Two patients with a decreased chemotactic response also had an impaired capacity to kill S. aureus. No correlation was found between the cell disturbance and susceptibility to infection, stage of the disease, or clinical course in these patients.

Adult↗
PubMed1982

Interaction of povidone-iodine compounds, phagocytic cells, and microorganisms.

The interaction between povidone-iodine, phagocytic cells, and microorganisms was studied. Three preparations of povidone-iodine were investigated: commercially available povidone-iodine solution Betadine, pure high-molecular-weight povidone-iodine as used in Betadine, and a low-molecular-weight povidone-iodine. Low concentrations of povidone-iodine (approximately 0.005%) have considerable activity in vitro. The concentrations used clinically (0.1 to 20%) are toxic for granulocytes and monocytes. Leukocytes reduce the in vitro microbicidal activity of povidone-iodine. No differences of any importance were found between the three preparations of povidone-iodine.

Bacteria↗
PubMed1980

Effects of monocytopenia and anticoagulation in experimental Streptococcus sanguis endocarditis.

The role of blood monocytes in the attachment of streptococci to endocardial vegetations was investigated in an experimental Streptococcus sanguis endocarditis by depletion of blood monocytes with the cytostatic drug VP 16-213 alone and combined with anticoagulant treatment with warfarin sodium. The numbers of streptococci in the vegetations of control, monocytopenic, and monocytopenic/anticoagulated rabbits were comparable. In the vegetations streptococci were found mainly in areas free of phagocytic cells. It is concluded that streptococci do not have to be phagocytosed by monocytes in the circulation before being deposited on the surface of endocardial vegetations. Even the vegetations of intensively anticoagulated/monocytopenic rabbits showed colonies of streptococci embedded in polymerized fibrin and cellular material, this matrix possibly being held together by streptococcal dextran.

Animals↗
PubMed1976

Synthesis of immunoglobulin and secretory component by gastrointestinal mucosa in patients with hypogammaglobulinaemia or IgA deficiency.

Biopsies of intestinal mucosa from patients with adult hypogammaglobulinaemia or selective IgA deficiency have been studied for the ability to synthesize immunoglobulins and secretory component. Tissue fragments were cultured in vitro in medium containing 14C-labelled amino acids and newly snythesized proteins were detected by radioimmunoelectrophoresis. Synthesis of IgA, and in some cases IgG and IgM, was found in intestinal mucosal biopsies from hypogammaglobulinaemics and IgA-deficient subjects. Biopsies from all the patients also synthesized secretory component, but evidence was obtained which indicated that secretory component does not combine normally with IgA. Tissue sections of these biopsies have also been studied by immunofluorescence and immunoglobulin bearing cells have been demonstrated. The present findings demonstrate that immunoglobulin synthesizing cells are present in the intestinal mucosa of immunoglobulin-deficient individuals. Local immunoglobulin synthesis may partially explain why these patients do not often have major problems with intestinal infections.

Adolescent↗
PubMed1976

Antimicrobial factors in the exudates of skin windows in human subjects.

The "skin window" technique in which the horny layer of the skin is abraded with a high speed grinder has been used to study the appearance of proteins with antimicrobial activity in the fluid accumulating in damaged human skin. The fluid was absorbed into paper discs and protein levels measured by radial diffusion. The skin exudates contained about 45% as much IgG and IgM as the subjects' serum, but the amount of IgA (68% of the serum level) in the exudate was significantly greater, suggesting selective transport into the lesion. The fluid also contains complement proteins, lysozyme and lactoferrin. The methods used in this study may provide useful information about clinical situations in which susceptibility to cutaneous infection is increased.

Complement System Proteins↗