Possibilities and limitations of capillary electropherosis in pharmaceutical analysis.

Capillary electropherosis (CE) has been proved to be an important alternative to high-performance liquid chromatography (HPLC) in pharmaceutical analysis. However, when it comes to the analysis of compounds, e.g. impurities or metabolites, of very different polarity and water solubility CE and the related techniques come to its limits. This is demonstrated for the antipsychotic drug quetiapine and its impurities. A nonaqueous capillary electrophoresis (NACE) method was developed using a background electrolyte (BGE) composed of ammonium acetate dissolved in a mixture of acetonitrile and methanol including acetic acid to protonate the substances. The NACE method gave an excellent separation of all components. Since the conductivity of the BGE used in the NACE method is quite low and problems with current occurred, an additional aqueous capillary zone electrophoresis (CZE) method was developed for quetiapine and the two water soluble derivatives, using phosphate buffer as BGE. The method was validated with regard to repeatability and limit of detection.

Transmission of angiosarcomas from a common multiorgan donor to four transplant recipients.

We describe the donor tumor transmission of metastatic angiosarcomas to four transplant recipients through transplantation of deceased-donor organs, i.e. kidneys, lung and liver, from an apparently unaffected common female multiorgan donor. Fluorescent in situ hybridization of angiosarcoma cells confirmed that the tumor was of female donor's origin in male kidney recipients. Recent literature associated increased urokinase-plasminogen-activator-receptor (uPAR) and plasma soluble urokinase-plasminogen-activator-receptor (suPAR) levels with metastatic malignancies. Now we found that, compared to baseline levels, both deceased-donor kidney recipients showed increased uPAR transcripts in mononuclear cells as well as increased plasma suPAR levels after the diagnosis of metastatic angiosarcomas, i.e. 4 months after donor tumor transmission. These results show an association of uPAR/suPAR in donor tumor transmission of metastatic angiosarcomas in humans.

Nonmuscle myosin heavy chain-B expression in balloon-dilated and stented arteries: a study in the atherosclerotic Yucatan micropig.

BACKGROUND: Restenosis after balloon angioplasty is in part due to remodelling, whereas restenosis after stenting is entirely due to neointima formation. Nonmuscle myosin heavy chain-B (NMMHC-B) is expressed by vascular smooth muscle cells and because of its overexpression in restenotic lesions after balloon angioplasty, NMMHC-B is proposed as a potential therapeutic target. Because the mechanisms underlying restenosis after balloon angioplasty or after stenting are different we hypothesised that the expression of NMMHC-B would differ in balloon-dilated versus stented arteries. METHODS: To study the localisation and time course of expression of NMMHC-B, we performed stenting or balloon dilation in peripheral arteries of 16 atherosclerotic Yucatan micropigs and used serial intravascular ultrasound (IVUS) and angiography to measure geometric dimensions following balloon angioplasty or stenting. In situ hybridisation techniques were used to detect NMMHC-B mRNA. 5'-bromo-2'-deoxyuridine (BrdU) was administered to detect proliferating cells. By counting the number of silver grains in the different layers of the artery, we could compare the amount of expression at the different time points between the groups. RESULTS: In intima and media, NMMHC-B expression increased after balloon dilation and stenting and peaked at 7 days. In stented arteries, the expression of NMMHC-B remained high for up to 42 days after injury, whereas in balloon-dilated arteries it had normalised. In the adventitia of balloon-dilated arteries, but not of stented arteries, NMMHC-B expression peaked at 7 days. NMMHC-B expression was not limited to proliferating cells. CONCLUSION: NMMHC-B is expressed near sites of active repair after arterial injury, but not limited to proliferating cells. The different pattern of NMMHC-B expression after balloon dilation compared with stenting may be related to arterial remodelling, because stented arteries that do not remodel lack this conspicuous adventitial expression at 7 days.

Off-pump coronary artery bypass surgery compared with stent implantation and on-pump bypass surgery: clinical outcome and cost-effectiveness at one year.

BACKGROUND: Coronary revascularisation by means of surgery or percutaneous intervention plays an important role in the management of patients with ischaemic heart disease. Coronary bypass surgery without cardiopulmonary bypass (off-pump surgery) has been reintroduced into clinical practice to avoid complications related to the use of cardiopulmonary bypass. It is unknown whether off-pump surgery can match the outcomes of bypass surgery with cardiopulmonary bypass (on-pump surgery) or intracoronary stent implantation. METHODS: The Octopus study comprised two multicentre randomised trials. In the Octopump trial, on-pump surgery was compared with off-pump surgery (139 vs. 142 patients). In the Octostent trial stent implantation was compared with off-pump surgery (138 vs. 142 patients). The primary cardiac endpoint was survival free from the following cardiovascular events: stroke, myocardial infarction and repeated coronary revascularisation. Secondary endpoints included quality of life and cost-effectiveness. The uncertainty surrounding the cost-effectiveness analysis was addressed by bootstrapping. RESULTS: Octopump trial: at one year, event-free survival in the on-pump group was 90.6% and in the off-pump group 88.0% (difference 2.6%, 95% CI-4.6 to 9.8). Quality-adjusted years of life were 0.83 and 0.82 (p=0.81), respectively. On-pump surgery was associated with €2089 (14.1%) additional direct medical costs per patient (p<0.01). Off-pump was more cost-effective than on-pump surgery in 95% of bootstrap estimates. Octostent trial: at one year, event-free survival in the stent group was 85.5% and in the off-pump surgery group 91.5% (difference -6.0%, 95% CI -13.5 to 1.4). Quality-adjusted years of life were 0.82 and 0.79 (p=0.09), respectively. Stent implantation reduced direct medical costs by €2813 (26.0%) per patient (p=0.01). Stent implantation was more cost-effective in 95% of bootstrap estimates. CONCLUSION: In selected patients eligible for bypass surgery, there was no difference in cardiac outcome between on-pump and off-pump surgery. Off-pump surgery, however, was more cost-effective than on-pump surgery and may be preferred from an economic perspective. In selected patients eligible for percutaneous coronary intervention, stent implantation was more cost-effective than off-pump surgery while maintaining comparable cardiac outcome. Therefore, stent implantation rather than off-pump surgery can be recommended as a first-choice revascularisation strategy.

Association between early and three month cognitive outcome after off-pump and on-pump coronary bypass surgery.

OBJECTIVE: To describe the association between cognitive outcome in the first postoperative week and that at three months after both off-pump and on-pump coronary bypass surgery, and to make a direct comparison of early cognitive outcome after off-pump versus on-pump surgery. DESIGN: Randomised trial with an additional prediction study within the two randomised groups. SETTING: Three centres for heart surgery in the Netherlands. PATIENTS: 281 patients, mean age 61 years. INTERVENTIONS: Participants were randomly assigned to off-pump or on-pump coronary bypass surgery. MAIN OUTCOME MEASURES: Cognitive outcome, assessed by psychologists who administered neuropsychological tests one day before and four days and three months after surgery. A logistic regression model was used to study the predictive association between early cognitive outcome, together with eight clinical variables, and cognitive outcome after three months. RESULTS: Cognitive outcome in the first week after surgery was determined for 219 patients and was a predictor of cognitive decline after three months. This association was stronger in on-pump patients (odds ratio (OR) 5.24, p < 0.01) than in off-pump patients (OR 1.80, p = 0.23). Early decline was present in 54 patients (49%) after off-pump surgery and 61 patients (57%) after on-pump surgery (OR 0.73, p = 0.25). CONCLUSIONS: In patients undergoing first time coronary bypass surgery, early cognitive decline predicts cognitive outcome after three months. Early cognitive decline is not significantly influenced by the use of cardiopulmonary bypass.

[Remodelling of the arterial wall: a determinant of luminal stenosis and a factor with prognostic significance]. / Remodellering van de vaatwand: een determinant van lumenstenosering en een factor met prognostische betekenis.

A structural transversal change in artery size is a type of arterial remodelling. Luminal stenosis in atherosclerosis is not only determined by plaque increase, but also by remodelling of the vessel wall. Expansive remodelling prevents luminal stenosis by atherosclerotic plaque progression, whereas constrictive remodelling increases luminal stenosis. Expansive remodelling is associated with lesions that are frequently observed at sites of acute manifestations of atherosclerotic disease, such as myocardial infarction, and it is therefore a negative prognostic feature. Constrictive remodelling is associated with stable plaque lesions. Remodelling of the vessel wall also plays a role after interventions such as balloon angioplasty, heart transplantation and bypass surgery. For example, the most important determinant of restenosis after balloon angioplasty is constrictive remodeling.

Early outcome after off-pump versus on-pump coronary bypass surgery: results from a randomized study.

BACKGROUND: The use of cardiopulmonary bypass during coronary artery bypass surgery (CABG) has been associated with substantial morbidity. The recent introduction of cardiac stabilizers facilitates CABG without cardiopulmonary bypass (off-pump CABG), but it is unknown whether cardiac outcome after off-pump surgery is similar to that for the on-pump procedure. METHODS AND RESULTS: In a multicenter trial, 281 patients (mean age 61 years, SD 9 years) were randomly assigned to off-pump or on-pump CABG. In-hospital results and cardiac outcome and quality of life after 1 month are presented. Cardiac outcome was defined as survival free of stroke, myocardial infarction, and coronary reintervention. The mean numbers of distal anastomoses per patient were 2.4 (SD 1.0) and 2.6 (SD 1.1) in the off-pump and on-pump groups, respectively. Completeness of revascularization was similar in both groups. Blood products were needed during 3% of the off-pump procedures and 13% of the on-pump procedures (P<0.01). Release of creatine kinase muscle-brain isoenzyme was 41% less in the off-pump group (P<0.01). Otherwise, no differences in complications were found postoperatively. Off-pump patients were discharged 1 day earlier. At 1 month, operative mortality was zero in both groups, and quality of life had improved similarly. In both groups, 4% of the patients had recurrent angina. The proportions of patients surviving free of cardiovascular events were 93.0% in the off-pump group and 94.2% in the on-pump group (P=0.66). CONCLUSIONS: In selected patients, off-pump CABG is safe and yields a short-term cardiac outcome comparable to that of on-pump CABG.

Plaque burden, arterial remodeling and plaque vulnerability: determined by systemic factors?

OBJECTIVES: This study was designed to determine whether arterial remodeling and plaque vulnerability are influenced by systemic factors. BACKGROUND: Atherosclerotic luminal narrowing is caused by gradual plaque growth and arterial remodeling. In the acute phase, luminal narrowing may be accelerated by acute thrombus formation, usually precipitated by rupture of a vulnerable plaque. METHODS: Femoral arteries were obtained from elderly individuals at autopsy. Pairs of atherosclerotic femoral arteries from 42 individuals were examined. The arteries were divided in 1-cm intervals. Plaque size, the mode of arterial remodeling and histopathologic characteristics of plaque vulnerability (lipid-rich core and plaque inflammation) were compared between right and left femoral arteries obtained from the same individual. A role for systemic factors was assumed if a phenomenon was equally present in both arteries. RESULTS: There was concordance in average plaque size (r(2) = 0.5, p < 0.001), expansive remodeling (kappa = 0.42, p = 0.007) and occurrence of plaques containing a large lipid-rich core (kappa = 0.60, p = 0.001), but no concordance in plaque inflammation (kappa = 0.067, p = 0.61) between right and left arteries. CONCLUSIONS: These results suggest that not only the amount of atherosclerosis, but also arterial remodeling and lipid deposition in plaques, are influenced by systemic factors. The nonhomogeneous distribution of inflammation in atherosclerotic arteries supports the hypothesis that plaque inflammation is locally affected.

Shear-stress and wall-stress regulation of vascular remodeling after balloon angioplasty: effect of matrix metalloproteinase inhibition.

BACKGROUND: Constrictive vascular remodeling (VR) is the most significant component of restenosis after balloon angioplasty (PTA). Whereas in physiological conditions VR is associated with normalization of shear stress (SS) and wall stress (WS), after PTA the role of SS and WS in VR is unknown. Furthermore, whereas matrix metalloproteinase inhibition (MMPI) has been shown to modulate VR after PTA, its effect on the SS and WS control mechanisms after PTA is unknown. METHODS AND RESULTS: PTA was performed in external iliac arteries of 12 atherosclerotic Yucatan pigs, of which 6 pigs (7 vessels) received the MMPI batimastat and 6 pigs (10 vessels) served as controls. Before and after the intervention and at 6-week follow-up, intravascular ultrasound pullback was performed, allowing 3D reconstruction of the treated segment and computational fluid dynamics to calculate the media-bounded area and SS. WS was derived from the Laplace formula. Immediately after PTA, media-bounded area, WS, and SS changed by 20%, 16%, and -49%, respectively, in both groups. VR was predicted by SS and WS. In the control group, SS and WS had been normalized at follow-up with respect to the reference segment. In contrast, for the batimastat group, the SS had been normalized, but not the WS. The latter is attributed to an increase in wall area at follow-up. CONCLUSIONS: Vascular remodeling after PTA is controlled by both SS and WS. MMPI inhibited the WS control system.

Furin and membrane type-1 metalloproteinase mRNA levels and activation of metalloproteinase-2 are associated with arterial remodeling.

Matrix metalloproteinase (MMP) activation is an essential feature of pathological and physiological arterial enlargement or shrinkage. Recently, furin-activated membrane type-1 MMP (MT1-MMP) was identified as the in vivo activator of MMP2 in mice. Although arterial enlargement and shrinkage are important in several pathological processes, this proprotein convertase-MT1-MMP axis has not been described during arterial remodeling. In rabbit femoral and carotid arteries, we report an increase in furin and MT1-MMP mRNA levels before and at the onset of arterial remodeling followed by an increase in activated MMP2. This reveals the presence of the proprotein convertase-MT1-MMP axis in flow-induced arterial remodeling and identifies furin as a possible target for local intervention in pathological arterial remodeling.

The adventitia of atherosclerotic coronary arteries frequently contains Chlamydia pneumoniae.

The presence of Chlamydia pneumoniae in the human arterial system has mainly been determined in atherosclerotic plaque, whereas the adventitia has remained relatively unexplored. We assessed the presence of C. pneumoniae in all three vessel wall layers of coronary (n=72) and brachial (n=48) arteries in relation to local atherosclerosis. Immunohistochemical staining of C. pneumoniae was observed in plaque and adventitia. Cells stained for C. pneumoniae were detected in the same areas as cells stained for macrophages in adjacent sections. C. pneumoniae staining in the adventitia was associated with the extent and severity of atherosclerosis. Coronary sections with C. pneumoniae staining in both adventitia and plaque more often contained advanced atherosclerosis than sections with staining only in the adventitia. Staining was observed more often in the coronary artery than in the brachial artery (24/72 vs. 5/48 and 51/72 vs. 8/48 for plaque and adventitia, respectively, P=0.004 and P<0.001). PCR confirmed the presence of C. pneumoniae DNA in the adventitia. In summary, the adventitia of atherosclerotic coronary arteries frequently contains C. pneumoniae that seems to be located within macrophages. These results might indicate a possible route for infected circulating macrophages to home into atherosclerotic lesions in the artery via vasa vasorum.

Distribution of Chlamydia pneumoniae in the human arterial system and its relation to the local amount of atherosclerosis within the individual.

BACKGROUND: Chlamydia pneumoniae has been suggested to play a role in the origin of atherosclerosis. We studied the prevalence of C pneumoniae at multiple locations in the arterial system within the same individual. Studying the association between atherosclerosis and C pneumoniae within the individual excludes confounding by interindividual variability. METHODS AND RESULTS: Postmortem, the presence in the intima/plaque and media of C pneumoniae membrane protein was determined by use of a C pneumoniae-specific monoclonal antibody. In 24 individuals, 33 arterial locations were studied (n=738 segments). Area stenosis was determined in adjacent cross sections. In all individuals, immunostaining of C pneumoniae was observed in >/=1 artery. The highest prevalences were observed in the abdominal aorta (67%), internal and common iliac arteries (41%), and coronary arteries (33%). The lowest prevalences were observed in the radial (0%) and cerebral (2%) arteries. Within the individual, area stenosis was larger in cross sections with immunoreactivity compared with cross sections without immunoreactivity (31.0+/-11.9% versus 14.3+/-6.1%, respectively; P:<0.001). In the individual, immunoreactivity was observed in 15+/-10% of the arteries (range, 3% to 45%). Between individuals, the percentage of arteries with immunoreactivity to C pneumoniae was associated with the average area stenosis throughout the arterial system (r(2)=0.56, P:<0.001). CONCLUSIONS: C pneumoniae was mostly observed at locations that are related to clinically relevant features. Within the individual, the distribution of C pneumoniae is associated with the distribution of atherosclerosis. The role of the microorganism in atherosclerotic disease remains to be elucidated.

Oral matrix metalloproteinase inhibition and arterial remodeling after balloon dilation: an intravascular ultrasound study in the pig.

BACKGROUND: Inhibition of matrix metalloproteinase (MMP) activity after balloon angioplasty by intraperitoneal injection of batimastat reduces late lumen loss by inhibition of constrictive remodeling. In the present study, we investigated whether the oral MMP inhibitor marimastat inhibits constrictive remodeling in favor of neutral or expansive remodeling. METHODS AND RESULTS: In 26 pigs, balloon dilation was performed in 101 peripheral arteries. Pigs were treated with marimastat or served as controls and were euthanized 42 days after intervention. Intravascular ultrasound was performed at all time points. Vessel area (VA) loss was assessed by calculating the change in VA at termination relative to after intervention. Arteries were divided in 3 categories: expansive remodeling (VA loss < -5%), neutral (-5% +5%). In the marimastat group, a significant reduction (53%) of late lumen loss was observed that was fully explained by impaired constrictive remodeling. In the marimastat group, the prevalence of constrictive remodeling was reduced (38% versus 75% in the control group) in favor of not only neutral but also expansive remodeling (21% and 42% versus 4% and 21% in the control group, respectively, P:<0.01). In contrast to the control group, acute luminal gain in the marimastat group did not correlate with late VA loss. CONCLUSIONS: Irrespective of the acute luminal gain by balloon dilation, the oral MMP inhibitor marimastat inhibited constrictive arterial remodeling in favor of both neutral and expansive remodeling.

Hemodynamic changes with right lateral decubitus body positioning in the tilted porcine heart.

BACKGROUND: In beating-heart coronary surgical procedures, exposure of posterior vessels through sternotomy causes cardiac function to deteriorate. We hypothesized that turning the subject to the right lateral decubitus position before cardiac retraction improves exposure of posterior vessels and preserves cardiac pump function on displacement. METHODS: Eight 80-kg open-chest pigs were instrumented with catheter-tip manometers. After a stepwise 60-degree turn to the right lateral decubitus position of the body, the heart was retracted anteriorly to 90 degrees with a suction stabilizer. RESULTS: Right lateral body positioning caused an approximately 45-degree right deviation of the apex, thereby exposing the left atrial groove. Stroke volume, mean arterial pressure, right atrial pressure, and right ventricular end-diastolic pressure increased to 106% +/- 5% (mean +/- standard error of the mean, p = 0.31), 106% +/- 3% (p = 0.01), 129% +/- 8% (p = 0.001), and 171% +/- 14% (p = 0.002), respectively, compared with control values. In contrast, left atrial pressure decreased to 73% +/- 6% (p = 0.007), whereas left ventricular preload remained unchanged (110% +/- 8%, p = 0.26). Additional anterior displacement to 90 degrees fully exposed the posterior vessels, and stroke volume decreased to 90% +/- 3% (p = 0.01) and mean arterial pressure to 93% +/- 5% (p = 0.07) at the expense of further increased right ventricular preload (256% +/- 28%, p < 0.001). CONCLUSIONS: By placing the subject in the right lateral decubitus position, exposure through sternotomy of posterior vessels in the beating porcine heart was facilitated while mean arterial pressure was maintained.

Effect of vascular freezing on the histopathology of dissected small vessels in the rat: vascular freezing does induce intimal hyperplasia in arteries and veins.

Intimal hyperplasia is the primary response of a vessel wall after injury. It may be the single most significant factor affecting long-term patency. The purpose of this study was to find out whether freeze injury, inflicted on rat microvessels, would be followed by intimal hyperplasia. Toward this aim, we exposed the superficial femoral vessels in the rat. On one side they were frozen using liquid nitrogen spray. The other side was dissected as the control. Vessel segments, harvested immediately and after 1, 2, 3, and 5 months, were studied light microscopically for the occurrence and content of intimal hyperplasia. In the arteries a considerable intimal hyperplasia was found within a 4-week interval, persisting for at least 5 months, as a result of the freeze injury. In the veins, the intimal hyperplasia was much less marked but was nevertheless demonstrable. These findings are not in agreement with earlier studies, in which freezing of injured rat microarteries with liquid nitrogen spray was followed by complete regeneration of the vessel wall, without intimal hyperplasia taking place. The factors contributing to these differences are discussed. It is concluded that freezing of a vessel wall is followed by intimal hyperplasia, which is part of the normal healing process.

Arteriotomy closure by glued patch in the porcine carotid artery.

BACKGROUND: A thoracoscopic approach to coronary bypass grafting warrants renewed search for facilitated vascular anastomosis methods. We reassessed tissue adhesion, sealing properties, and histotoxicity of iso-butyl-cyanoacrylate, in a simplified anastomosis model. METHODS: In 12 Dutch landrace pigs, five arteriotomies were made in each carotid artery. The arteriotomies were closed by conventional microvascular suturing or by pericardial patch (Peri-Strips) and iso-butyl-cyanoacrylate. The animals were sacrificed at 2 hours (n = 2), 2 days (n = 5), and 4 weeks (n = 5). The arteries were examined by flow measurement, angiography, and histologic analysis. RESULTS: The time required to close arteriotomies by conventional suturing was 257 +/- 43 seconds (mean +/- SD) and by glued patch 51 +/- 27 seconds (p < 0.001). In all arteriotomies covered by glued patch, complete hemostasis was obtained. At 2 days and 4 weeks, with both methods the same histologic results were observed. At follow-up, all carotid arteries were patent without stenoses. CONCLUSIONS: Arteriotomy closure by glued patch was simple, fast, reliable, and without signs of histotoxicity. Adhesives deserve to be reconsidered as an alternative to suturing in closed chest beating-heart coronary surgery.

Coronary anastomotic devices: theory and patented ideas on micromechanical fastening.

Coronary anastomotic devices are being designed to reduce the laborious, complex suturing approach to endoscopic coronary surgery. An anastomotic device should be safe and reliable, it should allow full view of the vessel parts to be bonded, it must provide a simple and rapid deployment, and should be hemodynamically adequate. Three anastomotic device categories found in the (patent) literature are discussed that use micromechanical fastening techniques. First, devices using individual bonding elements; second, devices using bonding elements anchored to extra-luminal frames; third, devices using an internal frame, often a stent-like structure. Anastomotic devices described in the (patent) literature to date fail to meet all requirements for endoscopic coronary application.