Human neutrophil migration into skin chambers is associated with production of NAP-1/IL8 and C5a

Respiratory burst activity initiated by the chemoattractants fMLP, rC5a and rNAP-1/IL8 was investigated in human exudated and peripheral blood neutrophils. Exudated cells were isolated after migration into a skin chamber and the respiratory burst activity was measured as chemiluminescence amplified by luminol and horseradish peroxidase. The response to fMLP (5 x 10(-8) mol/l) was significantly enhanced (p less than 0.01) in the exudated cells but was significantly decreased after stimulation (5 x 10(-8) mol/l) with rC5a and rNAP-1/IL8 (p less than 0.05 and p less than 0.01, respectively). Analysis revealed that, in the chamber fluid, the activated complement C5a was generated during exudation (p less than 0.01). Determinations of NAP-1/IL8 showed that this substance was also produced and released into the chamber fluid (p less than 0.01). No correlation was found between the number of exudated cells and the amount of C5a or NAP-1/IL8 in the exudation fluid, thus indicating that, in vivo, the exudation process is controlled by multiple factors and not by the quantity of a single chemoattractant. The present study shows that NAP-1/IL8 and C5a are produced in humans during an aseptic inflammation, and that this occurs in parallel to the migration of neutrophils into the skin chambers. The significant desensitization of the exudated cells to NAP-1/IL8 and C5a reflects a previous exposure to these attractants. These results suggest that the novel tissue-derived cytokine NAP-1/IL8 plays a role in human neutrophil exudation in vivo.     

Antinociceptive Effects and Spinal Distribution of Two Adenosine Receptor Agonists after Intrathecal Administration

The dose-activity relationship of various positive inotropic drugs has been investigated in the spontanously beating right atria of the rat. The influence of dose regimen and age has been evaluated. There is a significant difference between the maximal response of single and cumulative dose experiments with amrinone (P<0.05) and dobutamine (P<0.001) in animals aged 2 months and in dopamine (P<0.001) in animals aged 4 months. The maximum response is lowered significantly with age for isoprenaline with single (P<0.05) and for dopamine and dobutamine with cumulative dosing (P<0.001). In the single dose study the response is achieved within 4 min. for isoprenaline, noradrenaline, dobutamine, xamoterol and amrinone, but not until after 14 min. for prenalterol. It is concluded that both age and methods used in the study of pharmacodynamics are important. Thus when comparing effects the use of the same method and tissue from rats of the same age is necessary.     

Announcement

The microanatomy of ensheathing and early myelinating rat oligodendrocytes was analyzed through electron microscopic examination of serial sections. The study included cells in the spinal cord (SC) ventral funiculus and the corpus callosum (CC), containing early myelinating, prospective large axons and late myelinating, prospective small axons, respectively. The results show that ensheathment commences fetal day (F) 19 in the SC and 12 days postnatally (P12) in the CC. By then, multipolar SC and CC oligodendrocytes provide axons with uncompacted cytoplasmic sheaths. The average number of axons ensheathed by each such cell was 7 in the SC and 13 in the CC. The mean diameter of the ensheathed axons was 0.69 μm in the SC and 0.36 μm in the CC. The formation of compact myelin had clearly been initiated at birth in the SC and at P17 in the CC. At that stage, the mean number of myelinated axons per analyzed oligodendrocyte was 3 in the SC and 15 in the CC. The mean diameter of the myelinated axons was 1.02 μm in the SC and 0.54 μm in the CC. These observations show that myelin-related rat oligodendrocytes are morphologically heterogeneous. It also seems that this heterogeneity is related to time of onset of myelination and prospective axon diameter. Further, the data suggest that some oligodendrocytes reduce the number of sheaths initially elaborated before formation of compact myelin. © 1994 Wiley-Liss, Inc.     

Embolization of Spinal Metastases Reduces Peroperative Blood Loss: 21 Patients Operated on for Renal Cell Carcinoma

We evaluated the peroperative blood loss in 21 patients who were treated with 29 operative procedures for thoracolumbar spinal renal cell carcinoma metastases. Embolization was undertaken prior to 11 operations. At posterior surgery the average blood loss was one third after embolization compared with when embolization had not been performed. The blood loss was also lower during anterior surgery, although this difference was smaller. We recommend that preoperative embolization should precede surgical treatment of spinal metastases of renal cell carcinoma where it can be anticipated that the operation will extend into the pathological tissue.     

A universal spine tester for in vitro experiments with muscle force simulation

Summary We report a new apparatus to determine the quasistatic, three-dimensional, load-displacement characteristics of spines including muscle forces. The loading frame can be adapted to mono- and polysegmental specimens from the lumbar or cervical spine as well as to entire spines. Three force and three moment components can be applied in either direction individually or in combination with no constraint on the resulting motion; the loads can be applied at user-chosen rates of application and release with continuous recording of displacements, so as to study either creep or relaxation. The loads and displacement-measuring devices are computer-controlled. Thus, this testing device provides a tool for many kinds of stability tests and for basic research of spine biomechanics. A first experiment shows that the application of muscle forces significantly affects the load-deformation characteristics and intradiscal pressure.     

A combined electromyographic and cineradiologic investigation in patients with defecation disorders

Records from 20 patients on whom defecography and electromyography were performed simultaneously because of defecation disorders were analyzed. According to the electromyographic investigation, the patients could be divided into three main groups: 1) normal sphincter reaction; 2) paradoxical sphincter reaction; and 3) combined reaction. Group A was characterized by a marked reduction of muscular activity during emptying and a pronounced closing reflex after emptying. This was followed by return of normal tonic activity. Patients in group B had no relaxation of the sphincters during emptying but a pronounced increased activity in the external sphincter and the puborectalis muscle. They also had severe emptying difficulties at defecography. No closing reflex was seen. In group C the electrical activity in the sphincters increased during moderate straining and when emptying was complete a clear closing reflex was seen. In this study, a dynamic visualization of the defecation together with a registration of electromyographic activity in the striated anal sphincters was performed. It was shown that patients with paradoxical sphincter reaction were lacking a closing reflex after emptying was complete. This has not been reported previously and is important evidence for the paradoxical defecation pattern. It was also shown that the patients with rectoceles had paradoxical sphincter reaction.     

Systematic set-up errors for IMRT in the head and neck region: effect on dose distribution.

BACKGROUND AND PURPOSE: There is a general concern about intensity modulated radiation therapy (IMRT) treatments being more sensitive to patient positioning than conventional treatments. The aim of this study was to evaluate the International Commission on radiation units and measurements (ICRU) method for taking systematic set-up errors into account for IMRT treatments and to compare the effects on the dose distribution with the effects of conventional treatments. MATERIAL AND METHODS: A planning margin to account for set-up errors was added to the clinical target volumes and to the spinal cords, for three head and neck patients, according to the ICRU. No margin was added to organs at risk with mainly parallel structure if they were situated adjacent to the target volume, for example, the parotid glands. The effects of set-up errors in six IMRT plans and three conventional plans were simulated in the planning system and analysed with physical dose parameters. RESULTS AND CONCLUSIONS: In general, the ICRU method of taking set-up errors into account works satisfactorily for IMRT treatments as well as for conventional treatments with no difference between the treatment techniques. The sensitivity to set-up errors regarding the target volume is dependent on the quality of the treatment plan, i.e. the part of the target covered with a dose >95 and <105% and the effect in the critical organs is dependent on the sharpness of the dose gradients outside the critical organ. However, the method makes it difficult to include organs at risk with mainly parallel structure if they are situated adjacent to the target volume.     

Association of amount of physical activity with cortical bone size and trabecular volumetric BMD in young adult men: the GOOD study.

In this population-based study, amount of PA was associated with cortical bone size (increased thickness and periosteal circumference) and trabecular vBMD, but not with cortical vBMD or length of the long bones in young men. The lowest effective amount of PA was > or = 4 h/week. INTRODUCTION: Physical activity (PA) is believed to have positive effects on the skeleton and possibly help in preventing the occurrence of osteoporosis. Neither the lowest effective amount of PA needed to induce an osteogenic response nor its effect on the BMD and size of the different bone compartments (i.e., trabecular and cortical bone) has yet been clarified. MATERIALS AND METHODS: In this population-based study, we investigated the amount of all types of PA in relation to areal BMD (aBMD), trabecular and cortical volumetric BMD (vBMD), and cortical bone size in 1068 men (age, 18.9 +/- 0.02 years), included in the Gothenburg Osteoporosis and Obesity Determinants (GOOD) study. aBMD was measured by DXA, whereas cortical and trabecular vBMD and bone size were measured by pQCT. RESULTS AND CONCLUSIONS: The amount of PA was associated with aBMD of the total body, radius, femoral neck, and lumbar spine, as well as with cortical bone size (increased thickness and periosteal circumference) and trabecular vBMD, but not with cortical vBMD or length of the long bones. The lowest effective amount of PA was > or = 4 h/week. aBMD, cortical bone size, and trabecular vBMD were higher in subjects who started their training before age 13 than in subjects who started their training later in life. Our data indicate that > or = 4 h/week of PA is required to increase bone mass in young men and that exercise before and during the pubertal growth is of importance. These findings suggest that PA is imperative for the augmentation of cortical bone size and trabecular vBMD but does not affect the cortical vBMD in young men.