No abstract available.
Bile Ducts, Extrahepatic* ; Carcinoma, Hepatocellular*

The objectives of this investigation were to evaluate biomechanical factors in the atherosclerotic process using human in vivo hemodynamic parameters and computed numerical simulation qualitatively and quantitatively. The three-dimensional spatial patterns of steady and pulsatile flows in the left coronary artery were simulated, using a finite volume method. Coronary angiogram and Doppler ultrasound measurement of the proximal left coronary flow velocity were performed in humans. Inlet wave velocity distribution obtained from in vivo data of the intravascular Doppler study allowed for input of in vitro numerical simulation. Hemodynamic variables, such as flow velocity, pressure and shear stress of the left anterior descending coronary bifurcation site were calculated. We found that there were spatial fluctuation of flow-velocity and recirculation areas at the curved outer wall of the left anterior descending coronary artery, which were due to the differences of flow-velocity and shear stress, especially during the declaration phase of pulsatile flow. This study suggests that rheologic properties may be a part of the atherogenic process in the coronary bifurcated and curved areas.
Biomechanics ; Blood Flow Velocity/physiology ; Blood Pressure/physiology ; Coronary Arteriosclerosis/physiopathology* ; Coronary Arteriosclerosis/etiology* ; Coronary Vessels/physiopathology* ; Hemodynamics/physiology* ; Homeostasis/physiology ; Human ; Models, Cardiovascular* ; Pulsatile Flow ; Stress, Mechanical

Gastrointestinal strongyloidiasis and Cytomegalovirus infection mostly occur in patients receiving cancer chemotherapy, undergoing immunosuppressive therapy after organ transplantation, and suffering from acquired immune deficiency syndrome. A 56-year-old man was admitted to the hospital because of abdominal pain and constipation. He had a 10-year history of chronic obstructive pulmonary disease and has been treated intermittently with systemic steroid. The gastroduodenoscopic examination showed a single ulcer on the duodenal bulb and microscopic finding of the biopsy specimens from the ulcer revealed Strongyloides stercoralis and cytomegalovirus immunohistochemical stain positive intranuclear inclusion body on the mucosal surface. The patient was successfully treated with albendazole and ganciclovir.
Abdominal Pain ; Acquired Immunodeficiency Syndrome ; Albendazole ; Biopsy ; Coinfection ; Constipation ; Cytomegalovirus ; Cytomegalovirus Infections ; Duodenal Ulcer ; Ganciclovir ; Humans ; Intranuclear Inclusion Bodies ; Middle Aged ; Organ Transplantation ; Pulmonary Disease, Chronic Obstructive ; Steroids ; Stress, Psychological ; Strongyloides ; Strongyloides stercoralis ; Strongyloidiasis ; Transplants ; Ulcer

The present study in angulated coronary stenosis used human in vivo hemodynamic parameters and computed simulation, both qualitatively and qualitatively, to evaluate the influence of flow velocity and wall shear stress (WSS) on coronary atherosclerosis, the changes of hemodynamic indices following coronary stenting, and their effect on evolving in-stent restenosis. Initial and follow-up coronary angiographies in patients with angulated coronary stenosis were performed (n=60). The optimal degree of coronary stenting for angulated coronary stenosis had two models, the less than 50% angle changed group (model 1, n=33) and the more than 50% angle changed group (model 2, n=27). This angle change was based on the percentage change of vascular angle between pre- and post-intracoronary stenting. The flow-velocity wave obtained from in vivo intracoronary Doppler study data was used for in vitro numerical simulation. Spatial and temporal patterns of the flow-velocity vector and recirculation area were drawn throughout the selected segment of coronary models. WSS of pre- and post-intracoronary stenting was calculated from three-dimensional computer simulation. As results, follow-up coronary angiogram demonstrated significant difference in the percentage of diameter stenosis between the two groups (group 1: 40.3 +/- 30.2 vs. group 2: 25.5 +/- 22.5%, p < 0.05). Negative shear area on 3D simulation, which is consistent with the re-circulation area of flow vector, was noted on the inner wall of the post-stenotic area before stenting. The negative WSS disappeared after stenting. High spatial and temporal WSS before stenting fell within the range of physiologic WSS after stenting. This finding was more prominent in model 2 (p < 0.01). The present study suggests that hemodynamic forces exerted by pulsatile coronary circulation, termed WSS, might affect the evolution of atherosclerosis within the angulated vascular curvature. Moreover, geometric characteristics, such as the angular difference between pre- and post- intracoronary stenting might define optimal rheologic properties for vascular repair after stenting.
Adult ; Aged ; Biomechanics ; *Coronary Circulation ; Coronary Stenosis/*physiopathology/therapy ; Female ; *Hemodynamics ; Human ; Male ; Middle Age ; *Stents ; Stress, Mechanical