Centrosomal abnormality is common in and a potential biomarker for bladder cancer

Centrosomal abnormalities have been implicated in chromosomal segregation aberrations that result from the formation of multipolar mitotic spindles and lead to aneuploidy. Aneuploidy is a characteristic of neoplasia and underlies the development and progression of bladder cancer. Therefore, centrosomal abnormality may play a key role in urothelial tumor transformation. The purpose of our investigation was to determine whether centrosomal abnormalities are present in malignant urothelial cells, define the relationship between centrosomal abnormalities and aneuploidy and determine whether the presence of centrosomal abnormalities might be a potential diagnostic marker for bladder cancer. Bladder wash specimens obtained from patients with and without a history of urothelial carcinoma were analyzed for centrosomal abnormalities using an immunoassay with a gamma-tubulin antibody. FISH with centromeric probes for chromosomes 4 and 9 and DNA ploidy image analysis were performed to detect aneuploidy. Defective centrosomes were found in 40 of 45 bladder wash specimens from patients with bladder cancer but in none of the 10 samples from patients without it. A large percentage (69%) of grade 1 tumors were positive for centrosomal abnormalities, and these abnormalities were increasing in numbers and size in grade 2 (93%) and grade 3 (100%) specimens. Centrosomal abnormalities and numerical chromosomal aberrations frequently appeared concomitantly in the same malignant cells. All of the specimens showing aneuploidy also exhibited centrosomal abnormalities: centrosomal defects and aneuploidy occurred together in 80% of malignant bladder tumors, with an especially high percentage in higher-grade tumors. The overall positivity of centrosomal abnormalities was higher than that of aneuploidy (88% vs. 80%), especially in grade 1 tumors (69% vs. 46%), whereas aneuploidy was strongly associated with grade 2 and grade 3 tumors. Centrosomal abnormalities are common in bladder cancer, even in low-grade tumors, and strongly associated with cancer grade and aneuploidy, especially in high-grade neoplasms. Centrosomal abnormalities appear to be intrinsic to aneuploidy and tumorigenesis and may be potential markers for early detection of bladder cancer.     

Congenital disorders of glycosylation type Ia and IIa are associated with different primary haemostatic complications

Congenital disorders of glycosylation (CDG) type I are mostly due to a deficient phosphomannomutase activity, called CDG Ia. CDG IIa (mutations in the MGAT2 gene) results from a deficient activity of the Golgi enzyme N-acetylglucosaminyltransferase II. CDG Ia patients predominantly have a thrombotic tendency, whereas our CDG IIa patient has an increased bleeding tendency, despite similar coagulation factor abnormalities in both types. We have investigated whether abnormally glycosylated platelet membrane glycoproteins are involved in the haemostatic complications of both CDG groups. In flow cytometry, the binding of Ricinus communis lectin (reactive with -galactose primarily) to control platelets increased after neuraminidase treatment: this increase was smaller (p < 0.01) in CDG Ia patients (3.1 ± 0.08 times) than in control platelets (8.5 ± 1.8 times) and did not occur in the CDG IIa patient. Platelet-rich plasma from CDG Ia patients, but not a CDG IIa patient, aggregated spontaneously and gel-filtered platelets from CDG Ia patients agglutinated at very low concentrations of ristocetin, independently of von Willebrand factor (vWF). Accordingly, in stirred whole blood, the rate of single platelet disappearance of CDG Ia patients was twice that of control platelets. In contrast, perfusion of whole anticoagulated blood of the CDG IIa patient over collagen yielded markedly decreased platelet adherence to collagen at shear rates involving glycoprotein (GP) Ib–vWF interactions. Thus, abnormal glycosylation of platelet glycoproteins in CDG Ia enhances nonspecific platelet interactions, in agreement with a thrombotic tendency. The reduced GP Ib-mediated platelet reactivity with vessel wall components in the CDG IIa patient under flow conditions provides a basis for his bleeding tendency.     

Phosphorylcholine coating offers natural platelet preservation during cardiopulmonary bypass

Return of blood activated by tissue factor is the main culprit for triggering the coagulation cascade. When this activated blood is diverted from the cardiopulmonary bypass (CPB) circuit, it becomes possible to evaluate the effect of surface treatment on platelet and complement activation. Twenty adult patients undergoing elective coronary artery bypass grafting (CABG) were randomly assigned either to a control group (n=10) or to a group in which the CPB circuit was completely coated with phosphorylcholine (n=10). Plasma concentrations of platelet factor 4 (PF4), beta-thromboglobulin (betaTG), C3, C3d, C4, TCC, thrombin generation, haptoglobin and free haemoglobin, as well as blood loss, were measured. No significant differences between the two groups were found for haemolysis and thrombin generation. The mean total release of PF4 and betaTG during CPB was 9338+/-17303 IU/ml/CPB and 3790+/-4104 IU/ml/CPB in the coated group versus 22192+/-13931 IU/ml/CPB (p=0.011) and 8040+/-3986 IU/ml/CPB (p=0.005) in the control group. Blood loss was 30% less in the coated group compared to the control group. Phosphorylcholine coating appears to have a favourable effect on blood platelets, which is most obvious after studying the changes during CPB. Clinically, this effect resulted in a 30% reduction in blood loss.     

A monoclonal antibody recognizes a von Willebrand factor domain within the amino-terminal portion of the subunit that modulates the function of the glycoprotein IB- and IIB/IIIA-binding domains.

We developed a monoclonal antibody, 1C1E7, against vWf that increases ristocetin-induced platelet aggregation in a dose-dependent manner and lowers the threshold concentration of ristocetin needed to obtain a full aggregatory response. The platelet aggregatory effect of asialo vWf (ASvWf) also is enhanced by 1C1E7, in the presence or absence of glycoprotein (GP) IIb/IIIa receptor antagonism. In the presence of ristocetin, both intact 1C1E7 and its Fab fragments enhance specific binding of 125I-vWf to platelets. With 1C1E7, the intermediate and higher molecular weight multimers of vWf are preferentially bound to both GP Ib and GP IIb/IIIa. Thrombin-induced 125I-vWf binding to GP IIb/IIIa also is increased by 1C1E7. Maximal binding of 1C1E7 to vWf corresponds to 0.97 mol/mol vWf monomer with a Kd of 4.7 x 10(-10) M. 1C1E7 reacts with a 34/36-kD tryptic fragment (III-T4) and a 34-kD plasmic fragment (P34), which localizes the epitope between amino acid residues 1 and 272; this was confirmed by NH2-terminal amino acid sequencing. Finally, platelet aggregation by ASvWf was associated with a sharp rise in intracellular Ca2+ only in the presence of 1C1E7. An antibody-mediated conformational change of vWf may result in an improved presentation of the GP Ib- and GP IIb/IIIa-binding domains of mainly the larger multimers; the increased density of vWf on the platelet surface leads to platelet activation. The antibody may thus recognize a domain of relevance for vWf physiology.     

Role of proaggregatory and antiaggregatory prostaglandins in hemostasis. Studies with combined thromboxane synthase inhibition and thromboxane receptor antagonism.

Thromboxane synthase inhibition can lead to two opposing effects: accumulation of proaggregatory cyclic endoperoxides and increased formation of antiaggregatory PGI2 and PGD2. The elimination of the effects of the cyclic endoperoxides by an endoperoxide-thromboxane A2 receptor antagonist should enhance the inhibition of hemostasis by thromboxane synthase blockers. We have carried out a series of double-blind, placebo-controlled, crossover studies in healthy volunteers to check if this hypothesis may be operative in vivo in man. In a first study, in 10 healthy male volunteers, the combined administration of the thromboxane receptor antagonist BM 13.177 and the thromboxane synthase inhibitor dazoxiben gave stronger inhibition of platelet aggregation and prolonged the bleeding time more than either drug alone. In a second study, in 10 different healthy male volunteers, complete inhibition of cyclooxygenase with indomethacin reduced the prolongation of the bleeding time by the combination BM 13.177 plus dazoxiben. In a third study, in five volunteers, selective cumulative inhibition of platelet TXA2 synthesis by low-dose aspirin inhibited platelet aggregation and prolonged the bleeding time less than the combination BM 13.177 plus dazoxiben. In vitro, in human platelet-rich plasma stimulated with arachidonic acid, the combination of BM 13.177 and dazoxiben increased intraplatelet cAMP while the single drugs did not affect it. Our results indicate that prostaglandin endoperoxides can partly substitute for the activity of TXA2 in vivo in man and that an increased formation of endogenous antiaggregatory and vasodilatory prostaglandins, as obtained with selective thromboxane synthase inhibitors, may contribute to the impairment of hemostasis.     

Autotransfusion during aorto-iliac surgery

Red blood cell (RBC) quality and function during autotransfusion with the Solcotrans system were studied. Up to 64% (mean 999.5 +/- 310 ml) of the total volume of blood lost (mean 1895 +/- 707 ml) during operation in 10 patients undergoing elective abdominal aortic surgery was salvaged. No patient received homologous blood during surgery. Haemoglobin (Hb) and Haematocrit (PCV) values decreased but within acceptable limits. No evidence of DIC was found and renal function was unaffected. Mechanical and functional damage to the RBC was minimal and erythrocyte oxygen-carrying capacity was excellent. 2,3-DPGRBC concentration and RBC reduced glutathion were normal. The device was easy to handle and technical problems were not encountered. It was accurate in salvaging blood although the need for homologous blood was not entirely eliminated since four patients received homologous blood products in the postoperative period. No adverse clinical events occurred.     

Das primäre Leberkarzinom beim Säuglinge

Ohne Zusammenfassung     

Melting and crystallization of colloidal hard-sphere suspensions under shear

Shear-induced melting and crystallization were investigated by confocal microscopy in concentrated colloidal suspensions of hard-sphere-like particles. Both silica and polymethylmethacrylate suspensions were sheared with a constant rate in either a countertranslating parallel plate shear cell or a counterrotating cone-plate shear cell. These instruments make it possible to track particles undergoing shear for extended periods of time in a plane of zero velocity. Although on large scales, the flow profile deviated from linearity, the crystal flowed in an aligned sliding layer structure at low shear rates. Higher shear rates caused the crystal to shear melt, but, contrary to expectations, the transition was not sudden. Instead, although the overall order decreased with shear rate, this was due to an increase in the nucleation of localized domains that temporarily lost and regained their ordered structure. Even at shear rates that were considered to have melted the crystal as a whole, ordered regions kept showing up at times, giving rise to very large fluctuations in 2D bond-orientational order parameters. Low shear rates induced initially disordered suspensions to crystallize. This time, the order parameter increased gradually in time without large fluctuations, indicating that shear-induced crystallization of hard spheres does not proceed via a nucleation and growth mechanism. We conclude that the dynamics of melting and crystallization under shear differ dramatically from their counterparts in quiescent suspensions.The majority of complex fluids are non-Newtonian liquids. That is, when subjected to a shear flow, they exhibit shear thinning or shear thickening behavior. It has long been established that the macroscopic properties of a material are coupled to its microstructure. To understand the macroscopic behavior of flowing complex fluids, much research has been done on revealing the microstructure under shear.Apart from shear thinning and shear thickening, also shear banding, which is characterized by a discontinuous jump in the flow profile, is observed for many complex fluids (1). For worm-like micellar systems this has been extensively studied (2–5). Shear banding has also been observed in rod-like colloidal suspensions (6) and in crystallizing suspensions of spherical colloids (7–10), but for the latter, the number of studies is limited. Zukoski and coworkers (11–14) found the origin of shear banding with rheometry and small angle neutron scattering. They found that colloidal crystals shear thin discontinuously and that this is associated with a transition from a polycrystalline structure to a sliding layer structure. For not too soft potentials, these sliding layers have a hexagonal symmetry (15, 16). By using microscopy, it has been shown that this transition also leads to a shear banded flow (7).Shear has a dual influence on the order in colloidal suspensions. At high shear rates, it can disorder, or melt, a colloidal crystal (17–19), but at low shear rates or at low-amplitude oscillatory shear, it can induce order (20–22). Shear changes the growth kinetics, i.e., the induction time, density of nuclei, and crystal growth rate (23). This has been studied on soft spheres both with experiments (24, 25) and computer simulations (26–28). One of the characteristics reported for crystallization under flow is that the crystals align in 1 direction. Crystals with a different orientation are destroyed, after which they recrystallize in the preferred direction. Third, the nucleation rate depends on the stability of the crystal and liquid under shear. For soft spheres, the melting line shifts when a shear flow is applied (25, 26). For hard spheres, it is unknown whether or how the melting phase transition changes by shear, but a disordering transition is clearly evident from scattering experiments (16, 17).Most studies of complex fluids under shear have been done with light, X-ray, or neutron scattering. Scattering techniques have the disadvantage that the data are averages over the sampled volume; information about local processes cannot be obtained. Real-space experiments, using microscopy, have been undertaken to study behavior under shear in more detail. Two-dimensional colloidal crystals at a liquid interface were observed in real-space (29, 30) showing the motion of strings of particles past each other when sheared. Shear-induced crystallization has been observed in 3 dimensions in hard sphere suspensions under low-frequency oscillatory shear by taking snapshots at the extremes of the oscillation cycle (31). When crystals were confined to a narrow gap by applying oscillatory shear, several unusual crystal structures were found (32). Finally, Palberg et al. (33) used a special microscopy method in which positional correlations of particles could be directly imaged but not individual particles themselves. For confined, very soft colloids, these authors observed a zig-zag motion of sliding hexagonal layers as well as a disordering transition at higher shear rates (34, 35). Despite these efforts, a unified picture of the structural transitions of colloidal crystals under shear is still far from complete. Shear alignment of colloids has already been used to align large colloidal crystals for photonic applications (36) even on a semiindustrial scale (37–39), and it has also been reported in the related process of spin-coating (40–43).In previous work we examined sheared colloidal crystals in 3D using confocal microscopy and a counter rotating cone-plate shear cell (44, 45). The zig-zag motion of sliding hexagonal layers could be clearly observed and the local flow profile could be determined. As the shear rate was increased displacements of particles from their lattice positions grew larger, and particle diffusivity increased. The instrument used enables one to determine structure on a single-particle level. The counterrotation principle creates a plane of zero velocity in which a collection of particles can be tracked for an extended time. In the present work, we also used a counter translating parallel plate shear cell with a small enough plate separation that we could observe individual particles throughout the gap with a confocal microscope (46). This enabled us to obtain local information about the complete system. As we will show, local information is valuable in characterizing the sliding-layer structure and the observation of shear banding. Moreover, it reveals interesting differences between the local ordering and disordering dynamics in shear-induced melting and shear-induced crystallization. By looking at 2 different hard-sphere colloidal systems, we have tried to make sure that our observations were independent of system details of the interactions such as a short-ranged repulsion or the density mismatch with the solvent.     

Cardiovascular risk factors and global risk of fatal cardiovascular disease are positively correlated between partners of 802 married couples from different European countries. Report from the IMMIDIET project

Shared environmental factors may confer to spouses a similar risk for cardiovascular disease. We aimed at investigating in pairs the concordance in risk factors for cardiovascular disease and in global risk of cardiovascular events. In the framework of the IMMIDIET Project, married couples, recruited randomly from general practice, were studied. One thousand six hundred and four apparently healthy subjects aged 25-74 years from three different European populations were enrolled. Individual cardiovascular risks were estimated using SCORE risk equations. Age was strongly correlated within couples (r = 0.86, P < 0.0001). In multivariate model, within-pair correlation was high for social status (r = 0.49; percentage of explained variation = 24%) and percent of calories from lipids (r = 0.34; 12%). Concerning conventional metabolic risk factors, percentage of explained variation varied from 0.5% (triglycerides) to 11% (glucose). Among new risk factors, activated factor VII showed the strongest correlation (r = 0.28) and C-reactive protein the lowest (r = 0.13). Either total, coronary or non-coronary risk estimates at 10 years were strongly correlated within pairs: the risk of a member explained about two thirds of the cardiovascular risk of the partner. Spouse pairs share common lifestyle habits, common and new metabolic risk factors and the predicted global risk of cardiovascular events. If the individual risk of a person is influenced by the risk of his/her partner, decreasing the risk in a member of the pair should also decrease the risk in the partner. These concepts may have important public health consequences in targeting screening or disease prevention measures towards partners of people with cardiovascular risk.