摘要:

We treated 14 patients suffering from critical limb ischemia (CLI) as defined by the Consensus Document, and in whom possibilities of surgical or percutaneous arterial reconstruction were excluded, by PGE1 60 µg i.v. daily during 3 weeks. Effects were evaluated by clinical, macrocirculatory and microcirculatory parameters during a follow-up of 1 year. After treatment with PGE1·, we noted a significant reduction in analgesic use and in pain score. The average tcpO2 values on the forefoot in the supine and sitting positions, with or without inhalation of O2 through a face mask, showed a significant improvement after 3 weeks, as well as capillary stage. Laser Doppler flux did not change, but was significantly higher in diabetic patients than in nondiabetics with CLI. In 4 patients (28%) no improvement could be found after 3 weeks’ treatment. Although in 6 patients the improvement lasted for up to 4 months, the legs eventually deteriorated. In 4 patients (28%) the legs were preserved after 1 year without further active therapy. No patient with initial tcpO2 values above 40 mm Hg in the supine and 100 mm Hg in the sitting positions during O2 inhalation lost a leg. Although other effects like local care could have influenced the outcome favorably, we noticed a beneficial albeit transient effect of PGE1 for the majority of our patients with CLI. TcpO2 measurements with O2 inhalation might be a valuable predictor of a positive long-term res

ISSN:0167-6865    

DOI:10.1159/000179151

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

In order to investigate laser Doppler (LD) flux motion in healthy subjects and patients with peripheral arterial occlusive disease (PAOD), spectrum analysis of LD signals is needed. Autoregressive analysis (AR) is presented as an alternative method of power spectrum estimation. This procedure is compared to the commonly used fast Fourier transform algorithm (FFT) by describing the analytical power of both spectra in the analysis of flux motion waves. LD signals were recorded from the forefoot of 8 healthy volunteers and 11 patients with different degrees of PAOD. The flux, concentration of moving blood cells and velocity signal was digitized and stored for off-line analysis. Special software was designed to calculate AR and FFT spectra of the LD signals and to compare the suitability of both methods for the spectral analysis of LD recordings. Additionally, three-dimensional spectrum diagrams were calculated to demonstrate time-dependent flux changes during standardized provocation maneuvers. AR facilitates the determination of frequency and amplitude of flux motion waves as compared to the FFT. Low frequency-large amplitude waves (LF waves) were detected in both groups. High frequency-small amplitude waves (HF waves), which predominantly appear in severe ischemia, were observed in 7 of the 11 patients and in 2 of the 8 controls. The spectra revealed pulsatile waves in all healthy controls, but only in 1 of the 11 patients. AR modelling allows a reliable description of important flux motion components and has considerable advantages in spectral estimation of LD signals as compared to the FFT.

ISSN:0167-6865    

DOI:10.1159/000179152

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

The observed positive correlation between cessation of red blood cell flow in capillaries at low perfusion pressures and the oxygen tension (PO2) in the superfusion solution may be due to oxygen-dependent arteriolar constriction. To test this hypothesis, we investigated capillary flow cessation during aortic occlusion and concomitant changes in diameters of terminal arterioles and capillaries in normal and vasodilated vascular beds of rabbit tenuissimus muscle (n = 15) by means of video intravital microscopy. In the vasodilated bed, arteriolar tone was eliminated by local application of 10-4M adenosine (ADO). The PO2 in the superfusate was varied locally, i.e., in the solution between objective lens and muscle surface. At a local PO2 of 40 mm Hg without ADO, flow ceased in about 50% of the capillaries during aortic occlusion while the arterioles dilated to 118% of control (median; p < 0.001). Addition of ADO led to an increase in arteriolar and capillary diameter to 220% (median; p < 0.001) and 121% (median; p < 0.05), respectively. Under ADO, the incidence of capillary flow cessation was reduced (p < 0.05) to about 20%. Elevation of the local PO2 from 40 to 100 mm Hg in the presence of ADO did not lead to a significant change in the incidence of flow cessation, nor to changes in arteriolar or capillary diameter. In the presence of ADO, median arteriolar and capillary diameters during aortic occlusion were 96% (p < 0.001) and 7% (p < 0.05) larger than their control diameters without ADO, respectively. In summary, it is suggested that the incidence of flow cessation may depend on both the arteriolar and the capillary diameter. Of these two factors, capillary diameter may be the most important one, because its changes affect the interaction between red blood cells and the vessel wall in the narrow capillaries, and, hence, the resistance to flow. In the presence of ADO, at elevated local PO2 levels flow cessation still occurs in about 20-30% of the capillaries, suggesting that arteriolar contraction is only in part responsible for the incidence of flow cessation.

ISSN:0167-6865    

DOI:10.1159/000179153

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Ten samples of pyogenic granuloma and 10 of normal skin from age- and sex-matched controls were grafted onto the chick embryo chorioallantoic membrane (CAM) to investigate their possible angiogenic activity. The angiogenic response in pathological and control implants was assessed on his-tologic sections by a planimetric point-count method 4 days after grafting. The CAM mast cells were also quantified. The vascular counts in the area underlying the pyogenic granuloma were four times higher than those of normal skin. A higher number of mucosa-like mast cells was detected in the intermediate mesenchyme of the CAM in pathological samples in comparison to controls. Pyogenic granuloma may promote angiogenesis leading to release of several angiogenic factors. The role played in angiogenic response by the inflammatory cells, mainly mast cells, forming the perilesional infiltrate was supported by this study.

ISSN:0167-6865    

DOI:10.1159/000179154

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Myeloperoxidase (MPO) activity is assessed for the quantification of neutrophil accumulation in tissues. In particular, it may be used to support in vivo data on leukocyte kinetics obtained by intravital microscopy and to clarify whether phenomena observed on the organ surface reflect the situation of the whole organ microcirculation. Previous measurements of MPO activity were limited by interference with other peroxidases and by inhibition of MPO activity by specific enzymes. To circumvent these limitations, a modified assay was devised that combined a two-step tissue homogenization technique with heat incubation in a continuous photometric measurement. MPO activity was quantified in neutrophils isolated from rat and rabbit whole blood, rat brain and rabbit lung and compared with intravital microscopic data on leukocyte accumulation. The modified assay is characterized by high reproducibility, strong correlation of MPO activity with number of neutrophils and full recovery of neutrophils added to tissue homogenate. MPO activity per neutrophil was 342.9 ± 11.7 mU/106 cells in rats and 40.3 ± 0.8 mU/106 cells in rabbits. MPO activity in tissue was significantly lower in rat brains (18.9 ± 29.7 mU/g) as compared to rabbit lungs (741 ± 67 mU/g). Whereas global cerebral ischemia/reperfusion did not increase MPO activity in rat brain (18.1 ± 26.1 mU/g), intravenous infusion of cobra venom factor (1,447 ± 407 mU/g) or endotoxin (1,439 ± 285 mU/g), enhanced MPO activity in rabbit lung. These results parallel microcirculatory data from the organ surface. Therefore they supplement the intravital microscopic observations by demonstrating that these are indeed representative of deeper parenchymal tissue

ISSN:0167-6865    

DOI:10.1159/000179155

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

The effects of an extract of Ginkgo biloba (EGb 761) on arteriolar spasm were confirmed using a preparation of rat cremaster muscle. When vasospasm was induced by rat serum, arteriolar constriction reached 25-30% of the initial diameter after 10 min. Intravenous injection of EGb 761 (30 mg/kg) 5 min after inducing spasm inhibited about 80% of this serum-induced vasoconstriction. As previous studies have shown that EGb 761 has an antiaggregatory effect on platelets, thrombin, serotonin (platelet-derived compounds that are present in the serum) and a thromboxane analogue (U46619) were also used to induce vasospasm. Administration of EGb 761 (30 mg/kg) 5 min after exposure of the preparation to serotonin (10-3M) or 10 min after exposure to thrombin (20 units) did not affect vasospasm induced by these agents. In contrast, treatment with this same dose of EGb 761 5 min after exposure of the preparation to U46619 (10-4M) abolished the arteriolar constriction induced by this agent in 15 min. The thromboxane/prostaglandin H2 receptor antagonist SQ29548 antagonized serum-induced vasospasm, indicating an involvement of thromboxane. Other experiments indicated that the effects of EGb 761 of counteracting vasospasm may be mediated in part by ginkgolide B, a triterpene constituent of the extract that is an antagonist of platelet-activating factor and in part by an ‘NO-like’ action of its proanthocyanidin constituents. Taken together, these results have revealed that EGb 761 treatment can antagonize the vasoconstrictor effect of thromboxane on arterioles. As thromboxane is implicated in many cardiovascular disorders, this property of EGb 761 may explain some of its beneficial clinical effects in such patholog

ISSN:0167-6865    

DOI:10.1159/000179156

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

The aim of this study was to examine whether the hyperpermeable structure of the liver endothelium in vivo is related to the interactions of hepatocytes in a culture system. The permeation of macromolecular FITC-labeled dextran (molecular weight 70,000) through a monolayer of bovine aortic endothelial cells (BAEC), cocultured with rat parenchymal hepatocytes (P-hep), was increased. When the BAEC were cocultured with nonparenchymal hepatocytes (N-hep), the permeability of the BAEC monolayer was not increased. However, when the BAEC were cocultured with a mixture of P-hep and N-hep (PN-hep), the BAEC monolayer was more permeable than when BAEC were cocultured with P-hep alone. The conditioned medium of P-hep did not alter the BAEC monolayer permeability, nor did the extracellular matrix of P-hep alter BAEC permeability. When the BAEC were cocultured with PN-hep, the F-actin content was not altered.These findings suggest that the interaction between hepatocytes and endothelial cells exerts an important effect on the hyperpermeable structure of the liver vessels in vivo.

ISSN:0167-6865    

DOI:10.1159/000179157

出版商:S. Karger AG    

年代:1996

数据来源: Karger

ISSN:0167-6865    

DOI:10.1159/000179158

出版商:S. Karger AG    

年代:1996

数据来源: Karger