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Therapeutic stimulation of collateral artery growth is a promising approach for treatment of cardiovascular diseases. Unfortunately, translation into clinical practice yet remains cumbersome. Cardiovascular physiology and anatomy are major determinants of vascular growth processes. Hence, large-animal models are needed to improve clinical translatability of preclinical research. Furthermore, acute complete occlusions are mostly applied in experimental research, whereas stepwise occlusions are more often observed in human disease. We developed a model of coronary collateral artery growth in which 1) the artery is occluded in a step wise approach, and 2) effects of local treatment can be measured individually for each supplying coronary vessel. A hemodynamically relevant stenosis was created by implantation of a tapered stent at day 0 (d0) in the left circumflex artery (LCX), followed by complete arterial occlusion at day 14 (d14). Fluorescent microspheres were injected for demarcation of perfusion territories at each time point. Three and four weeks after induction of stenosis, collateral conductance measurements were performed for each coronary artery separately using differently labeled fluorescent microspheres. Postmortem angiography after acute LCX occlusion confirmed the presence of preexistent coronary anastomoses in the pig. The tapered stent created a hemodynamically significant stenosis immediately postplacement (fractional flow reserve, 0.70 ± 0.03). Between day 21 and 28, collateral conductance significantly increased in both the left anterior descending (LAD) and the right coronary artery (RCA)-supplied, collateral-dependent territories (LAD d21, 0.77 ± 0.14; LAD d28, 1.35 ± 0.12; RCA d21, 0.88 ± 0.29; RCA d28, 1.70 ± 0.16 ml · min(-1) · g(-1) · 100 mmHg(-1)), indicating collateral artery growth. We here describe a new translational minimally invasive model of coronary collateral artery growth in pigs, according to a defined protocol of LCX-stenosis and subsequent occlusion, allowing preclinical evaluation of arteriogenic therapies.

MicroRNAs are short, nonprotein-coding RNA molecules that play a crucial role in the post-transcriptional regulation of gene expression. By binding to specific target sequences, mostly located in the 3'-untranslated region of their target mRNA, they can induce mRNA decay or translational inhibition. Unlike siRNA, microRNAs show imperfect matching to their target mRNAs and can therefore modulate the expression of several mRNA genes at once. Although microRNAs have already been extensively studied in invertebrates, their function in mammalian organisms and in human disease is largely unknown. Several studies have shown an important regulatory function of microRNAs in embryonic and postnatal blood vessel development. Here, we provide an overview on these recent findings and summarize these so-called "angiomiRs" and their mode of action., (Copyright © 2010 Elsevier Inc. All rights reserved.)

Objectives: To evaluate targeting of a microbubble contrast agent to platelets under high shear flow using the natural selectin ligand sialyl Lewis., Materials and Methods: Biotinylated polyacrylamide Sialyl Lewis or biotinylated carbohydrate-free polymer (used as a control) were attached to biotinylated microbubbles via a streptavidin linker. Activated human platelets were isolated and attached to fibrinogen-coated culture dishes. Fibrinogen-coated dishes without platelets or platelet dishes blocked by an anti-P-selectin antibody served as negative control substrates. Dishes coated by recombinant P-selectin served as a positive control substrate. Microbubble adhesion was assessed by microscopy in an inverted parallel plate flow chamber, with wall shear stress values of 40, 30, 20, 10, and 5 dynes/cm2. The ratio of binding and passing microbubbles was defined as capture efficiency., Results: There was no significant difference between the groups regarding the number of microbubbles in the fluid flow at each shear rate. Sialyl Lewis-targeted microbubbles were binding and slowly rolling on the surface of activated platelets and P-selectin-coated dishes at all the flow conditions including 40 dynes/cm2. Capture efficiency of targeted microbubbles to activated platelets and recombinant P-selectin decreased with increasing shear flow: at 5 dynes/cm2, capture efficiency was 16.11% on activated platelets versus 21.83% on P-selectin, and, at 40 dynes/cm2, adhesion efficiency was still 3.4% in both groups. There was neither significant adhesion of Sialyl Lewis-targeted microbubbles to control substrates, nor adhesion of control microbubbles to activated platelets or to recombinant P-selectin., Conclusions: Microbubble targeting using sialyl Lewis, a fast-binding ligand to P-selectin, is a promising strategy for the design of ultrasound contrast binding to activated platelets under high shear stress conditions.

Background: In 2005, a scoring system (CLASI, Cutaneous Lupus Erythematosus Disease Area and Severity Index) was developed for patients with cutaneous lupus erythematosus (CLE) to assess disease 'activity' and 'damage'. However, the CLASI does not give an accurate assessment of the severity in all disease subtypes., Objectives: The main objective of this study was to analyse critically the included parameters of the CLASI and to revise the activity and damage score taking into account various clinical features of the different subtypes of CLE. The revised CLASI (RCLASI) was also validated for use in clinical trials. Patients and methods A RCLASI was designed with regard to the anatomical region (i.e. face, chest, arms) and morphological aspects (i.e. erythema, scaling/hyperkeratosis, oedema/infiltration, scarring/atrophy) of skin lesions and evaluated by nine dermatologists who scored 12 patients with different subtypes of CLE to estimate inter- and intrarater reliability., Results: Reliability studies demonstrated an intraclass correlation coefficient (ICC) for an inter-rater reliability of 0.89 for the activity score [95% confidence interval (CI) 0.79-0.96] and of 0.79 for the damage score (95% CI 0.62-0.92). The ICC for intrarater reliability for the activity score was 0.92 (95% CI 0.89-0.95) and the ICC for the damage score was 0.95 (95% CI 0.92-0.98)., Conclusions: In the present study, a RCLASI was developed by experts, and reliability studies supported the validity and applicability of the revised scoring instrument for CLE. Thus, the RCLASI is a valuable instrument in multicentre studies and for the clinical evaluation of activity and damage in different disease subtypes.

Endocarditis due to Actinomyces neuii is a rare disease, with only 14 reported cases. Recently, A. neuii was added to the list of species implicated in endocarditis of native valves. We now report the first case of prosthetic valve endocarditis and the first successful control of endocarditis caused by this organism without surgical intervention.

Unlabelled: During collateral artery growth, monocytes adhere to the endothelium and secrete cytokines from the perivascular space promoting arteriogenesis. Recently, the endothelial glycocalyx has been shown to modulate leucocyte infiltration in atherogenic regions. The role of this endothelial surface coating in arteriogenesis, however, has not been investigated so far. We now report that local plasma levels of hyaluronic acid are specifically increased in collateral arterial blood of coronary artery disease patients and hypothesized that components of the endothelial glycocalyx are shed during arteriogenesis, resulting in decreased glycocalyx dimensions and an increased leucocyte extravasation. In a rabbit model of femoral artery ligation, electron microscopy revealed a decrease in glycocalyx dimensions in collateral arteries compared with quiescent anastomoses (67.5 +/- 47.2 nm versus 101.0 +/- 11.3 nm; P < 0.001). This decrease was correlated with a higher number of perivascular macrophages around collateral arteries. The additional glycocalyx perturbation by local hyaluronidase infusion almost completely removed the endothelial surface layer and temporarily stimulated leucocyte accumulation in the perivascular space. However, complete perturbation of the glycocalyx by hyaluronidase infusion resulted in a significant attenuation of collateral artery growth assessed by microsphere-based perfusion measurements (ml/min/100 mmHg: hyaluronidase: 27.5 +/- 3.5;, Controls: 47.1 +/- 3.83; P < 0.001) and a lower percentage of actively proliferating vascular smooth muscle cells. A decreased expression of the shear-stress regulated pro-arteriogenic genes eNOS and TGF-beta1 suggests an impaired mechanotransduction as the underlying mechanisms. For the first time, we describe the role of the endothelial glycocalyx in collateral artery growth. Although complete abrogation led to attenuated arteriogenesis, shedding of glycocalyx components is observed during collateral artery growth.

The present investigation evaluates the dental care situation of patients with head and neck cancer before and after radiotherapy. The situations of these patients in 1993 and 2005 were compared to detect similarities, differences and developments. In the years 1993 and 2005, 37 and 36 patients, respectively, with head and neck cancer treated by the local departments of otorhinolaryngology and of radiotherapy were examined consecutively according to their aftercare appointments. Time points of radiotherapy treatment of the patients evaluated in 1993 varied from 1984 to 1993. The patients evaluated in 2005 had received radiotherapy between 1998 and 2005. Therefore the applied radiotherapeutic regimen differed not only between the two groups of patients, but also within each group. The information for these investigations was provided anonymously. It was evaluated with descriptive statistics. The evaluation of the data shows distinct differences with respect to preventive and therapeutic dental care measures. In 2005, 35 out of 36 patients (97.2%) had a dental consultation before radiotherapy (1993, 65%). All 27 dentate patients (100%) obtained a splint for fluoride application (1993, none). 29% fewer edentulous patients were seen than in 1993. The number of teeth destroyed decreased from 19.2% (1993) to 7.8% in 2005. Mycoses due to Candida spp. and chronic failures in wound healing were rare (5.5%). In the course of the 12 years, prophylactic measures, such as the application of splints for fluoride treatment, were intensified. However, concepts for the dental care of patients undergoing radiotherapy, especially following the radiation, should be widened to avoid ruined teeth and long delayed wound healings.

The stimulation of the endogenous adaptive vessel growth (angiogenesis, arteriogenesis) provides a promising therapeutic approach for the large number of patients with vascular occlusive disease that is not eligible for current interventional treatments. Despite the proven efficacy of various factors in pre-clinical experimental studies, the successful translation of angiogenic therapies into clinical practice yet remains to be made. Most authors identified the mode of administrations as culprit for the neutral effects observed in the majority of clinical trials. Although experimental studies have proven the superiority of continuous intra-arterial application above other routes (iv, im, sc), clinical trials focused on either bolus therapy, iv or sc application respectively, due to the lack of technical solutions to fulfill the requirements of intra-arterial delivery. The recent developments in the field of drug eluting stents may offer new possibilities for local drug delivery. Local release of cytokines, such as TGF-beta, has been shown to induce collateral growth in an experimental model of PAD. Other factors might eventually render useful to stabilize atherosclerotic plaques downstream of the site of stent implantation.

Aims: An ongoing concept is that stem cells have the potential to regenerate the injured myocardium. In addition to direct vasorelaxing effects on the vasculature, which are mediated by an increased cAMP production leading to a decreased calcium influx in smooth muscle cells, parathyroid hormone (PTH) was recently shown to facilitate stem cell mobilization. Therefore, we analysed in a murine model of experimental myocardial infarction (MI) the influence of PTH treatment on survival, functional parameters, stem cell migration, and expression of vascular endothelial growth factor A (VEGF-A)., Methods and Results: Mice (C57BL/6) were treated with PTH (80 microg/kg/d) for up to 14 days after coronary artery ligation. Functional and immunohistochemical analyses were performed at days 6 and 30 after MI. Stem cells and VEGF expression in the myocardium were analysed by FACS and qRT-PCR at day 2 after MI. PTH-treated animals revealed a significant improvement of post-MI survival and myocardial function that was related to a subsequent reduction of left ventricular wall thinning and scar extension. Infarcted hearts of PTH-treated mice revealed increased numbers of CD45(+)/CD34(+) progenitor cells as well as an upregulation of VEGF-A mRNA associated with increased neovascularization and cell survival., Conclusions: PTH application after MI increases migration of angiogenic CD45(+)/CD34(+) progenitor cells to the ischaemic heart, which may attenuate ischaemic cardiomyopathy. As PTH is already used in patients with osteoporosis, our findings may have a direct impact on the initiation of clinical studies in patients with ischaemic heart disease.

Pharmacological attempts to stimulate the growth of collateral arteries (arteriogenesis) are evolving towards a new treatment option for patients with vascular occlusive diseases. This enlargement of small pre-existing anastomoses towards large conductance arteries takes place independent of local oxygen tension and is driven by changes in luminal shear stress and infiltration of circulating cells. With the increasing knowledge regarding the distinct differences between capillary sprouting (angiogenesis) and arteriogenesis, several cytokines and growth factors have been demonstrated to stimulate the growth of arterial blood vessels in preclinical models of vascular disease. However, the translation towards clinical practice remains difficult and first in-man trials show limited success. Intensive research especially regarding new drug delivery platforms and the potentially serious side effects of pro-arteriogenic therapeutics is warranted before stimulation of arteriogenesis could become a significant treatment option for vascular occlusive diseases. This review focuses on the recent advances in the field of collateral artery growth. In addition, possible means to overcome the hurdles that have hampered the clinical implementation of pro-arteriogenic therapies will be discussed.

Objectives: The purpose of this study was to develop a cytokine-eluting stent to stimulate collateral artery growth (arteriogenesis) in the peripheral circulation of the rabbit via local transforming growth factor (TGF)-beta1 release., Background: The stimulation of arteriogenesis with cytokines is a potential new treatment option for patients suffering from vascular occlusive diseases. However, the lack of a delivery platform for continuous intra-arterial application of pro-arteriogenic compounds has hampered the clinical implementation of this promising therapeutic strategy., Methods: Different polymer coatings were tested regarding their suitability for cytokine release. Fifty-four rabbits underwent implantation of bare-metal stents (BMS), polymer-only coated stents (PDLLA), polymer-coated TGF-beta1-eluting stents (TGF) in the iliac artery, or bolus infusion of TGF-beta1 and subsequent femoral artery ligation. Collateral artery growth was assessed with fluorescent microspheres, angiography, and histological quantification of the proliferation marker Ki67. In-stent neointima formation was measured in histological sections of plastic-embedded stents., Results: A TGF-beta1-loaded coating based on poly(D,L-lactide) released up to 2.4 microg active TGF-beta1 over a period of 24 h. Perfusion measurements revealed a significant increase in collateral conductance after TGF-beta1 stent implantation compared with the control groups ([ml/min/100 mm Hg] BMS: 47.8 +/- 2.5; PDLLA: 44.1 +/- 3.9; TGF: 91.3 +/- 32.6). Bolus infusion of TGF-beta1 had no effect. Collateral arteries showed a higher proliferation activity in the TGF-treated group. At 7 days, no significant difference in in-stent neointima formation was observed., Conclusions: We first describe the use of a cytokine-releasing stent to stimulate collateral artery growth. These results show that intra-arterial cytokine-releasing devices might serve as a novel platform for the delivery of compounds affecting biological processes downstream of the site of implantation.

Through transfer of an active, isoproturon degrading microbial community, pesticide mineralization could be successfully enhanced in various soils under laboratory and outdoor conditions. The microbes, extracted from a soil having high native ability to mineralize this chemical, were established on expanded clay particles and distributed to various soils in the form of microbial "hot spots". Both, diffusion controlled isoproturon mass flow towards these "hot spots" (6microg d(-1)) as well as microbial ability to mineralize the herbicide (approximately 5microg d(-1)) were identified as the main processes enabling a multiple augmentation of the native isoproturon mineralization even in soils with heavy metal contamination. Soil pH-value appears to exert an important effect on the sustainability of this process.

Two strains, E3 and F2, capable to mineralize 1,2,4-trichlorobenzene (1,2,4-TCB) were isolated from a chlorinated benzenes contaminated soil using (14)C-1, 2,4-TCB as carbon source. They were identified by their 16S rDNA coding genes and fluoresence in situ hybridization (FISH) analysis as members of the genus Bordetella. A similarity of 100% were observed between strains E3 and F2 with their 16S rDNA sequences. They had the highest homology of 100% with Bordetella sp. QJ2-5 and the closest relation to described species, Bordetella petrii (GDH030510) with a similary of 99.4%. Strains E3 and F2 could degrade about 90% of 1,2,4-TCB and mineralize 58% and 46% of 1,2,4-TCB to CO2 within 30 days in mineral liquid cultures, respectively. Biomass was formed during the mineralization process.

A soil which has been polluted with chlorinated benzenes for more than 25 years was used for isolation of adapted microorganisms able to mineralize 1,2,4-trichlorobenzene (1,2,4-TCB). A microbial community was enriched from this soil and acclimated in liquid culture under aerobic conditions using 1,2,4-TCB as a sole available carbon source. From this community, two strains were isolated and identified by comparative sequence analysis of their 16S-rRNA coding genes as members of the genus Bordetella with Bordetella sp. QJ2-5 as the highest homological strain and with Bordetella petrii as the closest related described species. The 16S-rDNA of the two isolated strains showed a similarity of 100%. These strains were able to mineralize 1,2,4-TCB within two weeks to approximately 50% in liquid culture experiments. One of these strains was reinoculated to an agricultural soil with low native 1,2,4-TCB degradation capacity to investigate its bioremediation potential. The reinoculated strain kept its biodegradation capability: (14)C-labeled 1,2,4-TCB applied to this inoculated soil was mineralized to about 40% within one month of incubation. This indicates a possible application of the isolated Bordetella sp. for bioremediation of 1,2,4-TCB contaminated sites.

In four different agricultural soils the long-term leaching behaviour of [14C]isoproturon was studied in outdoor lysimeters (2 m length, 1 m2 surface area). The herbicide was applied in spring 1997 and spring 2001. At the end of the first 4-year-investigation period between 0.13% and 0.31% of the applied radioactivity was leached. Isoproturon or known metabolites could not be detected in the leachate. However, shortly after the second application isoproturon and its degradation products 2-hydroxy-isoproturon and monodemethyl-isoproturon were leached via preferential flow in one of the lysimeters (Mollic gleysol) in concentrations of 4.5 microg L-1, 3.1 microg L-1 and 0.9 microg L-1, respectively, thus considerably exceeding the EU threshold limit of 0.1 microg L-1 for ground and drinking water. The results indicate that in soils where mass flow transfer dominates, leaching of isoproturon to groundwater is of low probability whereas in highly structured soils which have the tendency to form macropores, isoproturon can be transported via preferential flow to the groundwater.

Background: A growing number of patients suffer from peripheral artery disease (PAD). Current therapies are often limited by the extent of vascular pathology and the occurrence of restenosis after angioplasty. The stimulatory effect of growth factor administration on collateral vessel formation (arteriogenesis) has evolved as a potential new treatment for this patient group. Granulocyte-macrophage colony-stimulating factor (GM-CSF) was shown to stimulate arteriogenesis in small-animal models and in a pilot study in patients with coronary artery disease. Although a recent clinical study demonstrated disappointing results after subcutaneous GM-CSF application in patients with PAD, we hypothesized that intra-arterial cytokine application using implantable infusion pumps might well stimulate arteriogenesis in a large-species model of peripheral vascular disease. We also aimed to compare continuous and intermittent infusion regimens and to validate experimental and clinically available measurements of collateral artery growth., Methods: Twenty-four pigs underwent unilateral occlusion of the right femoral artery and received either GM-CSF continuously, GM-CSF intermittently, or phosphate-buffered saline (PBS). After 1 week, collateral conductance was determined under maximal vasodilatation with adenosine and by using a pump-driven extracorporal shunt system., Results: Conductance showed a significant stimulatory effect of GM-CSF on arteriogenesis (collateral conductance [mL/min/mm Hg]: PBS, 37.7 +/- 5.4; GM-CSF continuous, 69.2 +/- 12.5; GM-CSF intermittent, 71.5 +/- 11.1). Flow measurements under reactive hyperemia were consistent with these results (flow occluded/non-occluded hind limb: PBS, 40.5% +/- 9.1%; GM-CSF continuous, 48.9% +/- 3.9%; GM-CSF intermittent, 48.7% +/- 4.4%). Measurements of ankle/brachial indices were not sensitive enough to detect the differences in collateral growth between the three groups., Conclusion: These results demonstrate the proarteriogenic properties of GM-CSF in larger animal species, revealing comparable efficacy of continuous and intermittent intra-arterial infusion. Furthermore, we provide evidence that implantable pumps offer a possible means for the intra-arterial application of growth factors. Intra-arterial application of GM-CSF might be a future treatment option for vascular occlusive disease. Finally, we show that in the peripheral circulation, pressure measurements alone have a low sensitivity to determine the effects of proarteriogenic therapy compared with flow or combined flow-pressure measurements.

The genus Herbaspirillum of the Betaproteobacteria mainly comprises diazotrophic bacteria with a potential for endophytic and systemic colonization of a variety of plants. The plant-associated bacterial isolates N3(T), N5 and N9 were derived from surface-sterilized wheat roots. After phylogenetic analysis of 16S rRNA gene sequence data the isolates could be allocated to the genus Herbaspirillum, and 99.9 % similarity to the sequence of Herbaspirillum lusitanum P6-12(T) was found. A set of 16S rRNA gene-targeted oligonucleotide probes was developed for the identification of the three novel isolates and H. lusitanum (Hhilu446), and for the specific detection of several other Herbaspirillum species described recently. For higher phylogenetic resolution, the 23S rRNA gene sequences of all members of the genus was sequenced and used to construct a phylogenetic tree. Isolates N3(T), N5 and N9 formed a group that was distinct from all other Herbaspirillum species. In addition, isolate N3(T) and H. lusitanum P6-12(T) exhibited a DNA-DNA hybridization value of only 25 %. The value for DNA-DNA hybridization between N3(T) and other members of the genus Herbaspirillum was between 14 and 32 %; DNA-DNA hybridization between strain N3(T) and isolates N5 and N9 produced values above 95 %. This places the three isolates as representatives of a novel species within the genus Herbaspirillum. A Biolog GN2 assay supported this conclusion. The major fatty acids were C(16 : 1)omega7c, C(16 : 0) and C(18 : 1)omega7c, and the DNA G+C content ranged from 60.9 to 61.5 mol%. Therefore these three isolates should be classified within a novel species, for which the name Herbaspirillum hiltneri sp. nov. is proposed. The type strain is N3(T) (=DSM 17495(T)=LMG 23131(T)).

A standardized quantitative approach was developed to reliably elucidate the effect of increasing soil moisture on pesticide mineralization. The mineralization of three aerobically degradable and chemically different 14C-labeled pesticides (isoproturon, benazolin-ethyl, and glyphosate) was studied under controlled conditions in the laboratory at an identical soil density of 1.3 g cm(-3). The agricultural soils used are characterized by (i) large variations in soil texture (sand content 4-88%) and organic matter content (0.97-2.70% org. C), (ii) fairly diverse soil-water retention curves, and (iii) differing pH values. We quantified the effect of soil moisture on mineralization of pesticides and found that (i) at soil water potential < or = -20 MPa minimal pesticide mineralization occurred; (ii) a linear correlation (P < 0.0001) exists between increasing soil moisture (within a soil water potential range of -20 and -0.015 MPa), and increased relative pesticide mineralization; (iii) optimum pesticide mineralization was obtained at a soil water potential of -0.015 MPa, and (iv) when soil moisture approximated water holding capacity, pesticide mineralization was considerably reduced. As both selected pesticides and soils varied to a large degree, we propose that the correlation observed in this study may be also valid in the case of aerobic degradation of other native and artificial organic compounds in soils.

The specific antagonists of tumor necrosis factor-alpha (TNF-alpha), infliximab and etanercept, are established therapeutic agents for inflammatory diseases such as rheumatoid arthritis and Crohn's disease. Although the importance of TNF-alpha in chronic inflammatory diseases is well established, little is known about its implications in the cardiovascular system. Because proliferation of arteriolar connections toward functional collateral arteries (arteriogenesis) is an inflammatory-like process, we tested in vivo the hypothesis that infliximab and etanercept have antiarteriogenic actions. Sixty-three New Zealand White rabbits underwent femoral artery occlusion and received infliximab, etanercept, or vehicle according to clinical dosage regimes. After 1 wk, collateral conductance, assessed with fluorescent microspheres, revealed significant inhibition of arteriogenesis (collateral conductance): 52.4 (SD 8.1), 35.2 (SD 7.7), and 33.3 (SD 10.1) ml x min(-1) x 100 mmHg(-1) with PBS, infliximab, and etanercept, respectively (P < 0.001). High-resolution angiography showed no significant differences in number of collateral arteries, but immunohistochemical analysis demonstrated a decrease in mean collateral diameter, proliferation of vascular smooth muscle cells, and reduction of leukocyte accumulation around collateral arteries in treated groups. Infliximab and etanercept bound to infiltrating leukocytes, which are important mediators of arteriogenesis. Infliximab induced monocyte apoptosis, and neither substance affected monocyte expression of the adhesion molecule Mac-1. We demonstrated that TNF-alpha serves as a pivotal modulator of arteriogenesis, which is attenuated by treatment with TNF-alpha inhibitors. Reduction of collateral conductance is most likely due to inhibition of perivascular leukocyte infiltration and subsequent lower vascular smooth muscle cell proliferation. This is the first report showing a negative influence of TNF-alpha inhibitors on collateral artery growth.

Objectives: The objective of this study was to test the potential of aspirin and clopidogrel to influence collateral artery growth (arteriogenesis)., Background: Aspirin and clopidogrel are antiplatelet agents commonly used in the treatment of ischemic cardiovascular disease. Both inhibit platelet aggregation; however, they differ mechanistically because aspirin acts via cyclooxygenase (COX) inhibition, while clopidogrel noncompetitively antagonizes the P2Y12 adenosine diphosphate receptor. We hypothesized that aspirin, due to its anti-inflammatory effects through inhibition of COX activity could inhibit arteriogenesis. Given that clopidogrel does not affect COX activity, it would be less likely to interfere with collateral artery growth., Methods: Fifty-four New Zealand White rabbits received either saline, aspirin (10 mg/kg), or clopidogrel (10 mg/kg) for seven days after femoral artery ligation. Maximal collateral conductance was assessed with fluorescent microspheres under maximal vasodilation; cellular migration and proliferation (Ki-67) was evaluated by quantitative immunohistology., Results: Collateral conductance was significantly reduced by aspirin treatment, whereas clopidogrel had a neutral effect (saline: 0.94 +/- 0.04; clopidogrel: 0.94 +/- 0.05; aspirin: 0.64 +/- 0.03 ml x min(-1) x 100 mm Hg(-1) x g(-1); p < 0.001). Ki-67 proliferation indexes were consistent with these results (saline: 23.1 +/- 2.9%; clopidogrel: 23.5 +/- 1.1%; aspirin: 19.2 +/- 1.1% Ki-67-positive cells). Immunohistochemistry showed COX expression in collateral arteries and a significantly decreased monocyte/macrophage accumulation in the perivascular tissue after aspirin treatment. Cell adhesion molecule expression on monocytes after activation was significantly reduced by aspirin, which might explain the reduced migratory ability., Conclusions: In summary, clopidogrel had a neutral effect on natural arteriogenesis. Aspirin significantly inhibited collateral artery growth, probably due to its anti-inflammatory effect. Additional studies are needed to substantiate these results before translation into clinical practice.

Objective: Circulating leukocytes play a crucial role during arteriogenesis. However, known pro-arteriogenic compounds (MCP-1, GM-CSF) acting via monocytic pathways also exert positive effects on granulocytes and lymphocytes. The role of these two cell types in arteriogenesis remains yet to be clarified, which was the aim of the current study., Methods: Ninety New Zealand White Rabbits received either phosphate buffered saline (PBS), monocyte chemoattractant protein-1 (MCP-1), interleukin-8 (IL-8), neutrophil activating protein-2 (NAP-2) or lymphotactin (Ltn) via osmotic minipumps after unilateral femoral artery ligation. In vitro stimulation and in vivo assessment of chemoattraction confirmed cell-specific action of the compounds in rabbits. Arteriogenesis was evaluated by angiography and collateral conductance measurements using fluorescent microspheres. Quantitative immunohistology was used to quantify transmigrated leukocyte subtypes after infusion of the factors., Results: MCP-1 infusion attracts monocytes and granulocytes, whereas IL-8 attracts all three cell types albeit monocytes to a significantly lower degree than MCP-1. NAP-2 and lymphotactin selectively attract granulocytes, respectively, lymphocytes. Of the tested cytokines, only MCP-1 stimulates arteriogenesis, as assessed by collateral conductance measurements ((ml/(min 100 mmHg)): PBS, 50.70+/-5.15; MCP-1, 216.30+/-12.30; IL-8, 58.91+/-5.56; NAP-2, 66.83+/-8.72; Ltn, 52.80+/-5.37) and angiographic findings., Conclusion: This study for the first time provides evidence that not granulocytes or T-lymphocytes but monocytes are the key mediators of arteriogenesis.

Objective: Strategies to therapeutically stimulate collateral artery growth in experimental models have been studied intensively in the last decades. However, the experimental methods to detect collateral artery growth are discussed controversially and vary significantly. We compared different methods in a model of arteriogenesis in the rabbit hind limb and determined the effects on collateral flow of a known pro-arteriogenic factor, monocyte chemoattractant protein-1 (MCP-1), and a cytokine not previously evaluated for its arteriogenic efficacy, the adipocytokine leptin., Methods and Results: Forty-two New Zealand White rabbits received either MCP-1, leptin or PBS after ligation of the right femoral artery. The pro-arteriogenic effect of MCP-1 was confirmed by flow measurements during reactive hyperemia, as demonstrated by increased flow ratio (PBS 0.56+/-0.07 vs. MCP-1 0.77+/-0.06, no unit, p<0.0001), ankle-brachial index and microsphere-based conductance measurements (PBS 50.8+/-2.1 vs. MCP-1 225.8+/-8.8 ml/min/100 mm Hg, p<0.001). Biological activity of leptin on rabbit monocytes was shown by a dose dependent increase in Mac-1 expression. In-vivo administration of leptin also led to an increase in hyperemic flow and flow ratio (leptin 0.69+/-0.03, p<0.05 vs. PBS), but not to an increase in collateral conductance (leptin 54.7+/-4.1 ml/min/100 mm Hg, p=ns vs. PBS) or proliferation of vascular smooth muscle cells (Ki-67 staining: PBS 24.7+/-3.9%, leptin 22.7%+/-0.8% (p=ns), MCP-1 32.0+/-1.9% (p<0.01)). Ki-67 mRNA measured by real-time polymerase chain reaction increased (8.8+/-3.1-fold, p<0.01) during natural arteriogenesis, and was further enhanced (25.5+/-8.1-fold, p<0.005) after stimulation with MCP-1., Conclusion: MCP-1 and leptin increase collateral flow in the rabbit hind limb model. In contrast to MCP-1, leptin does not enhance direct markers of vascular proliferation such as collateral conductance under maximal vasodilation and proliferation indices. The observed increase in hyperemic collateral flow thus most probably can be attributed to the well-documented vasodilatory effects of leptin. These data stress the necessity of the use of proliferation markers and microsphere-based conductance measurements under maximal vasodilation in order to separate effects of substances on vascular proliferation from effects on vasodilation.

A peri-carinal tracheal laceration was produced in a 11-year-old cat during tracheal intubation. Before reconstructive surgery began, the leak was bypassed with an endobronchial tube positioned using endoscopy and direct vision. However, single-lung ventilation could not be sustained because the tube became dislodged and could not be repositioned. Consequently, surgery was completed with periods of intermittent apnoea interspersed with manually controlled hyperventilation. Cardiovascular variables were stable during anaesthesia and no signs of hypoxia were detected. The difficulties in maintaining endobronchial tube position resulted from the animal's small size relative to the dimensions of the endotracheal tube.

Monocyte adhesion to shear stress-activated endothelium stands as an important initial step during arteriogenesis (collateral artery growth). Using multiple approaches, we tested the hypothesis that monocyte adhesion via intercellular adhesion molecule-1 (ICAM-1) and selectin interactions is essential for adaptive arteriogenesis. Forty-eight New Zealand White rabbits received either solvent, monocyte chemoattractant protein-1 (MCP-1) alone, MCP-1 plus ICAM-mab, or MCP-1 plus an IgG2a isotype control via osmotic minipumps. After 7 days, collateral conductance was evaluated: solvent 4.01 (mL/min per 100 mm Hg), MCP-1 plus ICAM-mab 8.04 (versus solvent P=NS), and MCP-1 alone 33.11 (versus solvent P<0.05). Furthermore, the right femoral arteries of ICAM-1-/-, Mac-1-/- and mice having defective selectin interactions (FT4/7-/-) as well as their corresponding controls were ligated. One week later, perfusion ratios were determined by the use of fluorescent microspheres. FT4/7-/- mice did not show any significant difference in perfusion restoration whereas ICAM-1-/- and Mac-1-/- mice had a significant reduction in arteriogenesis as compared with matching controls (FT4/7-WT 37+/-9%, FT4/7-/- 32+/-3%, P=0.31; C57BL/6J 59+/-9%, ICAM-1-/- 36+/-8%, P<0.05; Mac-1-/- 42+/-3%, P<0.05). ICAM-1/Mac-1-mediated monocyte adhesion to the endothelium of collateral arteries is an essential step for arteriogenesis, whereas this process can proceed via selectin interaction independent mechanisms. Furthermore, in vivo treatment with monoclonal antibodies against ICAM-1 totally abolishes the stimulatory effect of MCP-1 on collateral artery growth, suggesting that the mechanism of the MCP-1-induced arteriogenesis proceeds via the localization of monocytes rather than the action of the MCP-1 molecule itself.

Our current knowledge regarding the efficacy of factors stimulating collateral artery growth in the peripheral circulation primarily stems from models in small animals. However, experimental models in large sized animals are a prerequisite for extrapolation of growth factor therapy to patients with peripheral atherosclerotic obstructive disease. Therefore, we have developed a novel porcine femoral artery ligation model using non-invasive and invasive evaluation techniques. In 12 young farm pigs and nine older minipigs, a ligation of the superficial femoral artery was performed. Using an intra-arterial catheter, phosphate buffered saline (PBS) was administered with a first-pass over the collateral vascular bed. Directly after ligation as well as after 2 weeks of continuous infusion of PBS, perfusion of the leg was measured using various flow and pressure parameters. Using a pump driven extracorporal system, collateral conductance was determined under maximal vasodilatation. Conductance decreased after acute ligation to similar levels in both young farm pigs as well as the older minipigs (both 9.3% of normal perfusion) and recovered after 2 weeks to a higher value in farm pigs compared with minipigs (22.4 vs. 12.7% of normal; P<0.05). Angiography using both X-ray and magnetic resonance imaging was performed to visualize the formed collateral arteries. To the best of our knowledge this is the first in vivo pig model for hemodynamic assessment of growth of collateral arteries in the peripheral circulation, that is suitable for evaluation of arteriogenic effects of growth factors or genes.

Monocyte chemoattractant protein-1 (MCP-1) stimulates the formation of a collateral circulation on arterial occlusion. The present study served to determine whether these proarteriogenic properties of MCP-1 are preserved in hyperlipidemic apolipoprotein E-deficient (apoE-/-) mice and whether it affects the systemic development of atherosclerosis. A total of 78 apoE-/- mice were treated with local infusion of low-dose MCP-1 (1 microg/kg per week), high-dose MCP-1 (10 microg/kg per week), or PBS as a control after unilateral ligation of the femoral artery. Collateral hindlimb flow, measured with fluorescent microspheres, significantly increased on a 1-week high-dose MCP-1 treatment (PBS 22.6+/-7.2%, MCP-1 31.3+/-10.3%; P<0.05). These effects were still present 2 months after the treatment (PBS 44.3+/-4.6%, MCP-1 56.5+/-10.4%; P<0.001). The increase in collateral flow was accompanied by an increase in the number of perivascular monocytes/macrophages on MCP-1 treatment. However, systemic CD11b expression by monocytes also increased, as did monocyte adhesion at the aortic endothelium and neointimal formation (intima/media ratio, 0.097+/-0.011 [PBS] versus 0.257+/-0.022 [MCP-1]; P<0.0001). Moreover, Sudan IV staining revealed an increase in aortic atherosclerotic plaque surface (24.3+/-5.2% [PBS] versus 38.2+/-9.5% [MCP-1]; P<0.01). Finally, a significant decrease in the percentage of smooth muscle cells was found in plaques (15.0+/-5.2% [PBS] versus 5.8+/-2.3% [MCP-1]; P<0.001). In conclusion, local infusion of MCP-1 significantly increases collateral flow on femoral artery ligation in apoE-/- mice up to 2 months after the treatment. However, the local treatment did not preclude systemic effects on atherogenesis, leading to increased atherosclerotic plaque formation and changes in cellular content of plaques.

Two useful techniques for the repair of caudal sacral fractures and sacrococcygeal fractures/luxations are described. Pre- and postoperative clinical, neurological and radiological findings in 16 operated animals (13 cats and 3 dogs) were compared with findings in 17 (13 cats and 4 dogs) conservatively treated animals. In the surgically treated patients follow up findings were characterized by absence of hyperesthesia and a higher number of animals with recovered tail function. The authors suggest the use of these techniques in cases of caudal sacral fractures or sacrococcygeal fractures/luxations.

First X-ray absorption spectroscopy experiments with a vibrating piezo-driven double-crystal monochromator (piezo-QEXAFS) and fluorescence detection are reported. It is shown that high-quality XANES spectra can be recorded on a time scale of about 50 ms per spectrum, even for very low concentrations of < 10 mmol l-1 using fluorescence detection. The quality of the spectra, possible applications, as well as present limits of the technique will be discussed.

X-rays of 205 horses having navicular disease and having been reexamined up to six times are evaluated. For this, the x-rays of each foreleg are evaluated in the dorsopalmar (Oxspring) and lateromedial view. Additionally to changes of the navicular bone, changes of the distal part of the toe are also assessed. Differences can be found in the radiographic process in view of the limitation of vascular foramina and cyst-like lesions. Vascular foramina with sclerotic rim grow less frequent than poorly defined ones and therefore allow for easier prognostication. Cyst-like lesions with sclerotic rim often stay unchanged or decrease separately, whereas poorly defined areas of rarefication show a stronger tendency to expand into the surrounding spongiosa. Changes of vascular and bone structure occur already within a few months, whereas most of the margination changes are already formed in the early stages of disease and proceed slowly. Finally the effects of the therapy are being examined for the radiographic course of disease. Following a neurectomy, a more intensive development of the changes can be observed. The rate of only minimally altered navicular bones as well as the often simultaneous occurrence of changes in the joints of the toe do not allow for a diagnosis only on the basis of radiographic findings. The often slow development of the pathological radiographic changes requires intervals of examination of at least one year and shows that prognostic statements can only be made with caution even after follow-up examinations.