Bo Norberg

The difference between random movement and chemotaxis: Effects of antitubulins on neutrophil granulocyte locomotion☆

Abstract The antitubulins demecolcine and podophyllic acid ethylhydrazide (SPI) were used in experiments designed to elucidate the role of centriole-associated cytoplasmic microtubules in the locomotion of human neutrophil granulocytes (PMNs). The PMN locomotion was studied as chemotaxis and as the velocity of random movement. The PMN chemotaxis was inhibited by demecolcine (0.01 μg/ml) and SPI (0.1 μg/ml), i.e. concentrations below the reported threshold ones for mitotic arrest in metaphase. The velocity of single PMNs during random movement was only slightly reduced by treatment with 0.5 μg/ml of SPI. PMN locomotion was not appreciably inhibited by SPI, 0.5 μg/ml. The discrepancies mentioned suggest that centriole-associated microtubules are essential structures in the PMN direction-finding or PMN directional movement of chemotaxis but not in the mechanism of PMN locomotion. The present observations might, at least in part, explain the beneficial effects of antitubulins on acute gout.

The role of cytoplasmic microtubules in polymorphonuclear leukocyte chemotaxis: Evidence for the release hypothesis by means of time-lapse analysis of PMN movement relative to dot-like attractants

Abstract The present experiments were designed to elucidate the role of cytoplasmic microtubules in the chemotaxis of human polymorphonuclear leukocytes (PMNs) by means of the Boyden chamber technique and by means of analysis of PMN locomotion around a dot-like attractant. Casein induced positive chemotaxis in a small and variable fraction of the PMNs in the Boyden chamber. The movements of individual PMNs in coverslip preparations of clotted autoplasma were analysed as regards velocity of locomotion, locomotive index and net radial dislocation relative to the cell centre, with or without a yeast-phagocytosing leukocyte as a dot-like attractant. PMNs without obvious attractants tended to leave the visual field, i.e. they had a negative net radial dislocation relative to the centre of the visual field. Their locomotive indices suggested that their disappearance from the visual field was due to random movement. In contrast, the locomotive indices of PMNs influenced by attractants suggested the presence of both positive and negative chemotaxis in the population of moving PMNs. Yeast-phagocytosing leukocytes attracted wandering PMNs isolated by the Isopaque-Ficoll method (IF-PMNs) with a force which approximately balanced the basic tendency of the IF-PMNs to leave the visual field. Selective pretreatment of the moving IF-PMNs with podophyllic acid ethylhydrazide (SPI), 0.5 μg/ml (1.05 × 10−6 M), did not inhibit their attraction towards the central yeast phagocyte. The attraction of wandering IF-PMNs towards the central yeast phagocyte was inhibited by selective pretreatment of the phagocytes with SPI, 0.5 μg/ml. These observations indicate that cytoplasmic microtubules have an essential role in the release of chemotactic substances from phagocytosing leukocytes but not in the direction-finding of attractant-approaching PMNs. From the present observations by means of SPI, it is suggested that antitubulin inhibition of the release of chemotactic substances from phagocytosing leukocytes is the mechanism of inhibition of PMN chemotaxis by sub-antimitotic antitubulin concentrations in vitro. The latter phenomenon is thought to reflect the cellular basis of the anti-inflammatory action of the antitubulins.

Analysis of polymorphonuclear leukocyte (PMN) migration by the leading-front technique. Random locomotion and chemotaxis.

Abstract The present study was designed to elucidate the contribution of non-stimulated random movement, stimulated random movement, antitubulin-resistant chemotaxis and antitubulin-sensitive chemotaxis to the casein-induced PMN migration into a micropore filter, evaluated by the leading-front technique. This analysis was conducted by a simplified test design including PMN migration, ( a ) without casein; ( b ) in a gradient of casein; and ( c ) in casein without gradient. Treatment with the antitubulin SPI (a podophyllotoxin derivative) inhibited PMN migration within a casein gradient down to the level of the stimulated PMN random movement induced by casein. The casein-induced PMN chemotaxis measured by the leading-front technique is thus composed of stimulated random movement and antitubulin-sensitive chemotaxis without evidence of antitubulin-resistant chemotaxis. It is suggested that the anti-inflammatory effects of the antitubulins (colchicine, podophyllotoxin, Vinca alcaloids, griseofulvin) are due to an inhibition of the antitubulin-sensitive chemotaxis.

Effect of short-term high-dose treatment with methenamine hippurate on urinary infection in geriatric patients with an indwelling catheter

SummaryAn evaluation has been made of the clinical and laboratory effects of short-term (34 days), high-dose (2 g×3 daily) treatment with methenamine hippurate (MH) of 14 geriatric patients with an indwelling catheter and clinical features of urinary tract infection. During MH treatment the number of catheter changes was halved, each catheter remaining in situ for an average of 12.0 days as compared to 6.2 days in the pre-treatment control period and 5.2 days in the post-treatment control period; the difference is significant (p=0.008; Friedman two-way analysis of variance). Urine pH was reduced (pH 7.0–6.5–7.0; p=0.01) and the standard bicarbonate in blood was slightly elevated (24.1–25.7–25.0 mmol/l; p=0.008) during the MH treatment period, when compared to pre- and post-treatment control periods. It is suggested that MH treatment reduced the complications associated with indwelling catheters due to reduction in urine pH, bacteriuria, and pyuria. Blockage of catheters is thought to be due to intraluminal salt precipitations with trapping of clumps, and is primarily not correlated with urine viscosity.

The oxalate-induced radial segmentation of the nuclei of lymphocytes and monocytes from peripheral blood. A possible screening test for metaphase-blocking agents.

SummaryIn previous studies, the oxalate-induced radial segmentation (RS) of lymphocyte nuclei was inhibited by the metaphase-blocking agents vinblastine, demecolcine, griseofulvin and podophyllic acid ethylhydrazide. The metaphase arrest induced by the cytostatics mentioned is thought to be due to microtubule disassembly. The present study demonstrates that the threshold concentration of RS inhibition by means of these metaphase-blocking agents was close to the threshold concentration of metaphase arrest for each substance. The oxalate-induced radial segmentation was not inhibited by some cytostatics which do not affect the microtubule stability. It was concluded that the oxalate-induced radial segmentation provides a convenient screening test for new substances suspected to have metaphase-blocking activity. The restrictive assumptions and requirements of this test are discussed.ZusammenfassungIn früheren Untersuchungen wurde die oxalatinduzierte Radialsegmentierung (RS) von Lymphozytenkernen durch metaphasenblockierende Substanzen verhindert: Vinblastin, Demecolcin, Griseofulvin und Podophyllinsäureäthylhydrazid.Man nimmt an, daß das Verweilen in der Metaphase-hervorgerufen durch die oben genannten Substanzen — auf der Auflösung der Mikrotubuli beruht.Die vorliegende Arbeit zeigt, daß die Schwellenkonzentrationen dieser (metaphasenblockierenden) Substanzen für die RS-Hemmung nahe der Schwellenkonzentration jeder einzelnen Substanz für die Metaphasenhemmung liegt. Die oxalat-induzierte RS wurde dagegen nicht von einigen anderen Zytostatika gehemmt, die auch nicht die mikrotubuläre Stabilität beeinflussen.Daraus läßt sich schließen, daß die oxalatinduzierte RS einen bequemen Screening-Test darstellt für neue Substanzen, bei denen man eine metaphasenblockierende Aktivität vermutet.Voraussetzungen und Grenzen dieses Testverfahrens werden im einzelnen diskutiert.

Urinary pH and the Indwelling Catheter

The pH of the urine within a blocked indwelling catheter was significantly higher than the pH of the first urine portion from the new catheter. This observation suggests that the urinary pH was changed in an alkaline direction within the indwelling catheter, probably due to the production of ammonia induced by urease from Proteus strains. This pH gradient could only be demonstrated under conditions where the circadian pH variations of the urine within the individual could be neglected.

Randomized double-blind study of prophylactic methenamine hippurate treatment of patients with indwelling catheters.

SummaryCatheterized patients with heavy bacteriuria and short catheter life received a shortcourse of antimicrobial therapy and then were allocated at random to double-blind treatment for 5 months with methenamine hippurate (MH), 1 g three times daily, or placebo 1 g 3 times daily. MH treatment reduced the number of catheter blockages and instances of spontaneous removal of the catheter, and doubled catheter life (p<0.001). It is suggested that the doubled catheter life was due to the reduced bacteriuria and lowering of urinary pH.

Initiation and direction of polymorphonuclear leucocyte locomotion. The particle collision hypothesis

A simple model of the initiation of locomotion, the random movement and the directional locomotion during chemotaxis is derived from observations on moving human polymorphonuclear leucocytes (PMNs). This model provides a unifying concept of initiation of PMN locomotion, PMN random movement and PMN chemotaxis. The lamellipodium is thought to be the direction-determining cell organelle.

Statistical Analysis of the Radial Segmentation of Lymphocyte and Monocyte Nuclei in vitro

SummaryIn previous studies the radial segmentation of lymphocytes and monocytesin vitro has been associated to a contraction of intermitotic residues of the mitotic spindle, parallel to a slow dissociation of cytoplasmic microtubules. In the present study it is demonstrated that the frequency distribution of radial segmented nuclei after incubationin vitro is skew and can probably not be approximated to any classical distribution. These facts form the rationale for evaluating experiments on radial segmentation by means of nonparametric statistics.ZusammenfassungIn früheren Untersuchungen wurde die Radialsegmentierung (RS) von Lymphozyten und Monozytenin vitro der Kontraktion in intermitotischen Resten der Mitosespindel zugeschrieben, und zwar parallel zu einer langsamen Auflösung der Mikrotubuli des Zytoplasmas.In der vorliegenden Arbeit zeigt sich, daß die Frequenzverteilung von RS-Kernen nach Inkubationin vitro ungleichmäßig ist und sich vermutlich mit keiner der klassischen Normalverteilungen annähern läßt.Aufgrund dieser Tatsachen erscheint es angezeigt, Experimente auf dem Gebiet der Radialsegmentierung mit Hilfe nichtparametrischer statistischer Methoden auszuwerten.