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  • 1
    ISSN: 1432-0584
    Keywords: Fluorochrome ; Chemotaxis ; Haptotaxis Transwell
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Most conventional assays for the in vitro measurement of polymorphonuclear leukocyte (PMN) migration are modifications of the Boyden chamber technique, which requires quantification of migrated cells on micropore filters. This quantification is accompanied by several disadvantages, comprising errors in direct cell counting, low sensitivity of turbidimetric methods, the loss of marker enzymes by activation of PMNs, or the use of radioactive isotopes. We set up an improved fluorometric method to measure chemotactic and haptotactic migration of PMNs using polycarbonate filter-bearing Transwell culture plate inserts. This improved fluorometric method allows the evaluation of effects of fluorescent-dye labeling on chemotaxis and haptotaxis - defined as cell migration due to cell surface-or matrix-bound gradients of chemoattractants —by collecting data in an automated system. Results were compared with data obtained from direct microscopic cell counting in Transwell experiments as well as in conventional 48-multiwell Boyden chamber assays. Calcein-AM and BCECF-AM proved to be fluorochromes with minimal effect on both types of PMN migration. We conclude that the fluorochromes are powerful tools for the analysis of PMN migration and allow modifications of chemotaxis/haptotaxis assays for automated quantification.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-0584
    Keywords: Key words Fluorochrome ; Chemotaxis ; Haptotaxis ; Transwell
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Most conventional assays for the in vitro measurement of polymorphonuclear leukocyte (PMN) migration are modifications of the Boyden chamber technique, which requires quantification of migrated cells on micropore filters. This quantification is accompanied by several disadvantages, comprising errors in direct cell counting, low sensitvity of turbidimetric methods, the loss of marker enzymes by activation of PMNs, or the use of radioactive isotopes. We set up an improved fluorometric method to measure chemotactic and haptotactic migration of PMNs using polycarbonate filter-bearing Transwell culture plate inserts. This improved fluorometric method allows the evaluation of effects of fluorescent-dye labeling on chemotaxis and haptotaxis – defined as cell migration due to cell surface- or matrix-bound gradients of chemoattractants – by collecting data in an automated system. Results were compared with data obtained from direct microscopic cell counting in Transwell experiments as well as in conventional 48-multiwell Boyden chamber assays. Calcein-AM and BCECF-AM proved to be fluorochromes with minimal effect on both types of PMN migration. We conclude that the fluorochromes are powerful tools for the analysis of PMN migration and allow modifications of chemotaxis/haptotaxis assays for automated quantification.
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  • 3
    ISSN: 1471-0528
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Objective A database with reference values of the durations of the various waveforms in a magnetocardiogram of fetuses in uncomplicated pregnancies is assessed. This database will be of help to discriminate between pathologic and healthy fetuses. A fetal magnetocardiogram is a recording of the magnetic field in a location near the maternal abdomen and reflects the electric activity within the fetal heart. It is a non-invasive method, which can be used with nearly 100% reliability from the 20th week of gestation onward.Design Durations of the waveforms were assembled from averaged magnetocardiograms and statistically processed.Setting Fetal magnetocardiograms were measured with different magnetocardiographs. All measurements were carried out in magnetically shielded rooms.Sample Fetal magnetocardiograms were obtained for 582 healthy patients.Method The durations of the waveforms were extracted from fetal magnetocardiograms measured at the cooperating centres. The variables collected included the duration of the P-wave, the PR interval, the PQ interval, the QRS complex, the QT interval and the T-wave and QTc value. The results were compared with values extracted from electrocardiograms of fetuses measured via electrodes attached to the maternal abdomen, from electrocardiograms measured during labour using a scalp electrode, and from electrocardiograms recorded in newborns, that were found in the literature.Main outcome measures Values of the durations are given as a function of gestational age including the regression line as well as the bounds marking the 90%, 95% and 98% prediction interval.Results The durations of the P-wave, the PR interval, the QRS complex, the QT interval and QTc value increase linearly with gestational age. The durations of the PQ interval and the T-wave are independent of fetal age.Conclusion The values found agree with those found in the literature. The scatter of the data is wide due to the variation in normal physiology, the measuring system and signal processing and the subjectivity of the researcher. However, the system can define normal ranges and may be used in diagnosis.
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  • 4
    ISSN: 0167-0115
    Keywords: Aqueous humor ; Indomethacin ; Prostaglandin ; Substance P ; Surgical miosis ; Timolol
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1432-1912
    Keywords: Key words Growth hormone deficiency ; Neutrophils ; Monocytes ; Respiratory burst ; Chemotaxis ; Treatment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The observations that growth hormone primes neutrophils and stimulates various activities of monocytes suggested that it plays a role in the regulation of leukocyte biology. The in vivo reduction of growth hormone levels may be responsible for to the functional impairment of leukocytes observed in growth hormone deficient children. Whether leukocyte function is impaired in growth hormone deficient adults is not known as yet. We therefore studied superoxide anion release from neutrophils and chemotaxis of monocytes in 15 patients with adult-onset growth hormone deficiency before and after a period of 6 months of replacement therapy with recombinant human growth hormone. Analyses were performed by comparing functions of the leukocytes from these patients with those from age and sex-matched healthy control subjects. Before growth hormone treatment, patients received appropriate replacement therapy with thyroid, adrenal and gonadal hormones. The dose of recombinant human growth hormone was 0.25–0.5 U/kg/week (0.013–0.026 mg/kg/day) throughout the whole period of replacement therapy. In growth hormone deficient subjects, formylpeptide-triggered release of superoxide anions from neutrophils was significantly suppressed by about 40% before treatment as compared to healthy control subjects. After 6 months of replacement therapy, neutrophil superoxide anion release was similar in patients and healthy individuals. Neither before nor after replacement therapy, however, was there a difference in monocyte migration between control and growth hormone deficient subjects. These data indicate that neutrophil function is somehow altered in growth hormone deficient patients, even when receiving appropriate therapy with thyroid, adrenal and gonadal hormones, but that neutrophil function can be restored to near normalcy by growth hormone replacement therapy. This would suggest that suppressed neutrophil respiratory burst is due to the deficiency in growth hormone.
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  • 6
    ISSN: 1432-1912
    Keywords: Key words Neutrophils ; Endothelium ; Migration ; Thalidomide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Vascular endothelium activated by endotoxin and cytokines plays an important role in organ inflammation and blood leukocyte recruitment. Neutrophils, which are a homogeneous population of effector cells, are rapidly attracted in large numbers to sites of inflammation where they form an early response to infection or injury. Excessive production of various interleukins, TNF, arachidonic acid metabolites, and other substances by neutrophils and macrophages results in systemic endothelial cell injury, a fundamental problem. In the present study, we investigated in vitro the effects of thalidomide (THD) on activation of endothelial cells for enhanced transmigration of neutrophils by lipopolysaccharide (LPS), tumor necrosis factor-alpha (TNF), and interleukin-1 (IL-1). Modulation of endotoxin- and cytokine-induced neutrophil chemotaxis and respiratory burst by THD were also studied. Treatment of HUVEC with THD in combination with LPS, TNF, and IL-1, respectively, antagonized LPS-activated transmigration of neutrophils but stimulated the effects of TNF and IL-1. All of the agents used – THD, LPS, TNF, and IL-1 – inhibited neutrophil chemotaxis. Addition of THD to the neutrophils had no effect on LPS-inhibited chemotaxis whereas the TNF- and IL-1-induced chemotaxis was modulated in a bimodal manner. However, THD failed to influence neutrophil respiratory burst activity. Results demonstrate that THD differentially affects mediator-induced activation of HUVEC and neutrophils.
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