Regional differences in statistical geometry of endothelial dense granules in human extremity veins.

OBJECTIVES: Leg and arm human veins are exposed to different gravitational stresses. We investigated if there is difference in the amount and geometry of secretory vesicles in their endothelium. METHODS: Superficial small vein segments were removed during vascular operations for electromicroscopic analysis. Vesicular area/total endothelial cross-sectional area was determined by computer-based morphometry. Long and short axes of granule cross sections were measured by image analyzing software. RESULTS: Vesicular density in all samples was 2.26 ± 0.34%. There was no significant difference between the vesicular densities of upper extremity and leg. The shape of the vesicles was more frequently elongated in leg than in arm sections (p < 0.01). CONCLUSIONS: The density of the vesicles does not depend on vascular region or orthostatic load. Ellipticity of these granules is significantly different in areas exposed to different gravitational stresses. This might contribute to the differences of thrombotic and hemodynamic properties of leg and upper body veins.

Comparison of passive and active biomechanical properties of human cervical and leg veins.

AIM: The aim of this study was to evaluate and compare passive and active biomechanical properties of human superficial veins exposed in vivo to different orthostatic stresses. METHODS: Superficial veins from jugular and saphenous regions were studied (11 segments each). Digitalized pressure-diameter curves were recorded in Krebs-Ringer solution, and after administration of 10-5M norepinephrine and 10-5M acetylcholine. Calcium-free solution was used to determine passive biomechanical properties. Similar tissue samples were collected for histochemistry. Resorcin-fuchsin stainings and immuno-histochemistry for smooth muscle actin were used. RESULTS: The outer radius of the relaxed samples was identical. Leg vein walls were thicker in Krebs-Ringer solution (110 ± 11 vs. 84 ± 7 µm at 30 mmHg). Isobaric wall stress was significantly higher in cervical veins. The significant differences in incremental distensibilities and elastic moduli were dependent on pressure level and smooth muscle tone. Spontaneous tone and norepinephrine induced contractions were significantly higher in leg veins (at 30 mmHg 18.3 ± 4.1 vs. 5.6 ± 1.8% and 37.6 ± 4.5 vs. 11.2 ± 4.3 %, respectively). Endothelial dilation was larger in cervical vein segments (3.8 ± 0.9% vs. 1.8 ± 0.5%). Resorcin-fuchsin and smooth muscle actin staining structures were more abundant in leg veins. CONCLUSION: Comparing active and passive biomechanical properties of human veins affected chronically by different orthostatic loading, we found several quantitative differences that reflect the physiological adaptation mechanisms to long-term gravitational stress.

Management of abdominal aortic and iliac artery aneurysms by stent-graft implantation in a patient on CAPD.

We present the case of a 76-year-old male patient, who - after 2.5 years of CAPD treatment - underwent aorto-biiliac aneurysm reconstruction for aorto-biiliac aneurysm by bifurcational stent-graft implantation. To our knowledge this is the first case presentation of a stent-graft implantation and uninterrupted continuation of CAPD treatment in a patient on peritoneal dialysis.

[Iatrogenic colorectal perforations--review of cases of the last twenty years]. / Iatrogen colorectalis perforációk--az elmúlt 20 év eseteinek áttekintése.

The experiences with the surgical therapy of 31 patients treated for iatrogenic colorectal perforations during twenty years (1979-1998) are reviewed by the authors. The factors leading to perforation and applied types of operations compared with the therapeutical methods suggested by the literature are summarized. For the treatment of immediately detected instrumental perforations of the well cleaned colon the justification of the suture and primary resection is stressed. The overall lethality, the operative mortality and the rate of perioperative complications were 9.7%, 6.7 and 36.7% respectively.