PMN heterogeneity: long-term stability of fluorescent membrane potential responses to the chemoattractant N-formyl-methionyl-leucyl- phenylalanine in healthy adults and correlation with respiratory burst activity

Polymorphonuclear neutrophils (PMNs) were isolated from 24 healthy adults 20 to 61 years of age and the proportion of cells that demonstrated depolarization responses to the synthetic chemotaxin N- formyl-methionyl-leucyl-phenylalanine (FMLP) were enumerated using the lipophilic fluorescent cyanine dye 3,3'-di-pentyl-oxacarbocyanine [di-O- C(5)(3)] and flow cytometry. The membrane potential responses were correlated to the cells' respiratory burst capabilities as measured by nitroblue tetrazolium (NBT) reduction and/or superoxide production in response to FMLP; 40.2% +/- 15.1% (mean +/- SD) of cells depolarized to FMLP. The mean SE for duplicate determinations 1 hour apart was 3.8% (range 0.4% to 13.6%, n = 15). There was no correlation between the percentage of depolarizing PMNs and the yield of cells, the percentage of immature cells, or the circulating WBC count. There was no difference in the average age of men (34.9 +/- 9.9 years, n = 11) v women (33.8 +/- 8.5, n = 13) (mean +/- SD) studied, or in the percentage of depolarizing PMNs when men and women were compared (42.2 +/- 10.6% v 43.1 +/- 13.3%, respectively). However, there was a significant increase in the percentage of depolarizing PMNs with increasing age of women (r = .61, P less than .025) but not men (r = .03, P greater than .05). Analysis of variance revealed significantly greater person-to-person variability in the membrane potential response than in day-to-day variability in the same person (P less than .0005). The percentage of depolarizing PMNs in response to FMLP was significantly correlated with the percentage of NBT-positive cells from both purified PMNs and from whole blood (r = .849, P less than .0005, r = .857, P less than .05, respectively), and with the amount of superoxide produced, expressed as a percentage of that amount produced by cytochalasin B (cyto-B)-pretreated cells (r = .565, P less than .01). The data indicate that PMNs from healthy adults demonstrate a heterogeneous membrane potential response to the chemotaxin FMLP that correlates with the cells' oxidative responsiveness and that intersubject differences can be detected. In addition, the proportion of responsive PMNs increases with increasing age in women.     

Stimulation of murine colony-forming cells with high proliferative potential by the combination of GM-CSF and CSF-1

Granulocyte-macrophage colony-stimulating factor (GM-CSF) has previously been shown to stimulate granulocyte, macrophage, and megakaryocyte lineages to act as an erythroid burst-promoting activity and to stimulate limited replication of spleen colony-forming cells. Here we demonstrate that murine GM-CSF alone or in combination with macrophage colony-stimulating factor (CSF-1) can stimulate colony- forming cells in bone marrow (BM) that have a high proliferative capacity. In cultures of BM from mice treated with 5-fluorouracil (FU) eight days before sampling, GM-CSF alone or in combination with CSF-1 stimulated the formation of large macrophage colonies with diameters greater than 0.5 mm. CSF-1 alone, at 800 units or greater, also stimulated larger colonies; however, these colonies were always less than 1.1 mm in diameter, whereas GM-CSF in combination with CSF-1 stimulated many colonies with diameters between 1 and 4 mm. At all doses of CSF-1 tested, the combination of factors resulted in a synergistic increase in colonies with diameters greater than 1.0 or 2.0 mm. Analysis of the incidence of colony-forming cells in the BM of normal mice and mice 2, 4, 6, and 8 days after FU treatment demonstrated that the progenitor cells stimulated by GM-CSF alone or in combination with CSF-1 were depleted by FU treatment in vivo and regenerated more rapidly than did the macrophage progenitors (M-CFC) stimulated by CSF-1 alone. This is similar to the properties of the previously described high-proliferative potential, colony-forming cell (HPP-CFC) that is responsive to interleukin-3 plus CSF-1 but not the HPP-CFC stimulated by hematopoietin 1 plus CSF-1. These data suggest that GM-CSF plus CSF-1 act synergistically to stimulate a population of progenitor cells that have a high proliferative potential and have properties similar to those of the population of HPP-CFC stimulated by interleukin-3 plus CSF-1.     

A new method of three‐dimensional coronary artery reconstruction from X‐ray angiography: Validation against a virtual phantom and multislice computed tomography

Objective : To develop and implement a method for three‐dimensional (3D) reconstruction of coronary arteries from conventional monoplane angiograms. Background : 3D reconstruction of conventional coronary angiograms is a promising imaging modality for both diagnostic and interventional purposes. Methods : Our method combines image enhancement, automatic edge detection, an iterative method to reconstruct the centerline of the artery and reconstruction of the diameter of the vessel by taking into consideration foreshortening effects. The X‐Ray‐based 3D coronary trees were compared against phantom data from a virtual arterial tree projected into two planes as well as computed tomography (CT)‐based coronary artery reconstructions in patients subjected to coronary angiography. Results : Comparison against the phantom arterial tree demonstrated perfect agreement with the developed algorithm. Visual comparison against the CT‐based reconstruction was performed in the 3D space, in terms of the direction angle along the centerline length of the left anterior descending and circumflex arteries relative to the main stem, and location and take‐off angle of sample bifurcation branches from the main coronary arteries. Only minimal differences were detected between the two methods. Inter‐ and intraobserver variability of our method was low (intra‐class correlation coefficients > 0.8). Conclusion : The developed method for coronary artery reconstruction from conventional angiography images provides the geometry of coronary arteries in the 3D space. © 2008 Wiley‐Liss, Inc.     

Periprosthetic Fracture Torque for Short Versus Standard Cemented Hip Stems: An Experimental In Vitro Study

In an attempt to preserve proximal femoral bone stock and achieve a better fit in smaller femora, especially in the Asian population, several new shorter stem designs have become available. We investigated the torque to periprosthetic femoral fracture of the Exeter short stem compared with the conventional length Exeter stem in a Sawbone model. Forty-two stems; 21 shorter and 21 conventional stems both with three different offsets were cemented in a composite Sawbone model and torqued to fracture. Results showed that Sawbone femurs break at a statistically significantly lower torque to failure with a shorter compared to conventional-length Exeter stem of the same offset. Both standard and short-stem designs are safe to use as the torque to failure is 7–10 times that seen in activities of daily living.     

Shear wave elastography for breast masses is highly reproducible

Objectives

To evaluate intra- and interobserver reproducibility of shear wave elastography (SWE) for breast masses.

Methods

For intraobserver reproducibility, each observer obtained three consecutive SWE images of 758 masses that were visible on ultrasound. 144 (19%) were malignant. Weighted kappa was used to assess the agreement of qualitative elastographic features; the reliability of quantitative measurements was assessed by intraclass correlation coefficients (ICC). For the interobserver reproducibility, a blinded observer reviewed images and agreement on features was determined.

Results

Mean age was 50 years; mean mass size was 13 mm. Qualitatively, SWE images were at least reasonably similar for 666/758 (87.9%). Intraclass correlation for SWE diameter, area and perimeter was almost perfect (ICC?≥?0.94). Intraobserver reliability for maximum and mean elasticity was almost perfect (ICC?=?0.84 and 0.87) and was substantial for the ratio of mass-to-fat elasticity (ICC?=?0.77). Interobserver agreement was moderate for SWE homogeneity (κ?=?0.57), substantial for qualitative colour assessment of maximum elasticity (κ?=?0.66), fair for SWE shape (κ?=?0.40), fair for B-mode mass margins (κ?=?0.38), and moderate for B-mode mass shape (κ?=?0.58), orientation (κ?=?0.53) and BI-RADS assessment (κ?=?0.59).

Conclusions

SWE is highly reproducible for assessing elastographic features of breast masses within and across observers. SWE interpretation is at least as consistent as that of BI-RADS ultrasound B-mode features.

Key Points

? Shear wave ultrasound elastography can measure the stiffness of breast tissue ? It provides a qualitatively and quantitatively interpretable colour-coded map of tissue stiffness ? Intraobserver reproducibility of SWE is almost perfect while intraobserver reproducibility of SWE proved to be moderate to substantial ? The most reproducible SWE features between observers were SWE image homogeneity and maximum elasticity

     

A step forward for the undulation pump total artificial heart

In the University of Tokyo, various types of total artificial heart (TAH) have been studied. Based on the experiences of TAH research, the development of the undulation pump total artifical heart (UPTAH) started in 1994. The undulation pump is a small-size, continuous-flow, displacement-type blood pump, and the UPTAH is a unique implantable total artificial heart that uses the undulation pump. To date, three models of UPTAH have been developed. The first model, UPTAH1, was developed to investigate the possibility of reducing the size of the device so it could be implanted in small adults, such as Japanese patients, in 1994. The second model, UPTAH2, which was the prototype of the animal experimental model, was developed in 1996 to investigate the possibility of survival with the UPTAH. The third model, UPTAH3, which is the present model, was developed in 1998 to enable long-term survival in animal experiments and to investigate the pathophysiology of the UPTAH. From July 1996 to October 1999, 22 implantations of UPTAH2 or UPTAH3 were performed in goats. In spite of the limitation of their small chest cavity, the UPTAH could be implanted into the chest of all goats. Using UPTAH3, survival of 31 days could be obtained. The research and development of UPTAH are ongoing.     

Induction of Th2 cell differentiation in the primary immune response: dendritic cells isolated from adherent cell culture treated with IL-10 prime naive CD4+ T cells to secrete IL-4

A number of observations indicate that exposure to IL-4 is essential for the priming of Th2-type effector T cells and that exposure to IL-12 is essential for the priming of Th1-type effector T cells. However, the initial source of IL-4 in the early immune response has not been clearly identified. Dendritic cells (DC) are the most potent antigen- presenting cells (APC) in priming naive T cells. In this report, we show that DC exposed to IL-10 may play an important role in the priming of IL-4-secreting cells in the early immune response. DC isolated from splenic adherent cell cultures treated with rIL-10 (IL-10-DC) primed naive ovalbumin (OVA)-TCR transgenic T cells to secrete IL-4 upon re- stimulation with OVA and splenic APC. By contrast, DC isolated from rIL- 12, rIL-4 or control treated cultures induced almost exclusively Th1- type effector T cells. IL-4 secretion was detected in the primary cultures of IL-10-DC plus naive CD4+ T cells and the priming of IL-4- secreting T cells by IL-10-DC was dependent on endogenous IL-4 production in the priming culture since anti-IL-4 neutralizing antibody completely abrogated the priming of IL-4-secreting cells. Anti-B7-2 but not anti-B7-1 inhibited the ability of IL-10-DC to prime T cells to secrete IL-4. Furthermore, the ability of IL-10 DC to prime for IL-4- secreting T cells was closely related to the down-regulation of CD40 ligand-mediated IL-12 p70 production by DC in the primary cultures and was markedly reduced by adding exogenous IL-12 to the priming cultures. Thus, our findings indicate that early immunologic events that drive Th2 differentiation involve the effects of IL-10 on DC.