1/6. Unusual intravascular hemolysis in a case of fatal hypothermia.A 55-year-old man was discovered dead inside a deep freezer maintained at -40 degrees C. After consuming a large quantity of alcohol, the man had become trapped in the freezer approximately 11 h before his body was found. The body was still frozen at the time of autopsy, but subcutaneous dendriform vessel repletion phenomenon was observed on the upper and lower extremities. Although this intravascular hemolysis resembled that which develops during putrefaction, in this case it was thought to be due to pooling and freezing of blood in subcutaneous vessels. Contributory factors included alcohol ingestion, vasodilation following vasoconstriction, vasomotor paralysis, and red cell sludging. hemolysis followed freezing of the blood. When such phenomena are observed in a corpse, exposure to extreme cold should be suspected.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
2/6. enterococcus durans endocarditis in a patient with transposition of the great vessels.A case of native valve endocarditis caused by enterococcus durans in a patient with transposition of the great vessels is reported. The patient was treated initially with gentamicin and ceftriaxone; after isolation of enterococci, ceftriaxone was switched to ampicillin. The only virulence factors established in the strain were haemolytic activity and biofilm formation.- - - - - - - - - - ranking = 2.5keywords = vessel (Clic here for more details about this article) |
3/6. Red cell fragmentation syndrome with the use of subclavian hemodialysis catheters.The red cell fragmentation syndrome can occur due to abnormalities of the heart or the blood vessels or vascular malformations. We describe three patients who developed symptomatic hemolytic anemia due to red cell fragmentation with the use of single-lumen subclavian hemodialysis catheters. Retrospective analysis of 75 other patients who had undergone dialysis through this catheter disclosed five additional cases. Red cell fragmentation appears to be associated with partial catheter occlusion by thrombus or development of a clot at the catheter tip or both. The fragmentation resolved in all cases on withdrawal of the catheter. All patients with this catheter should be closely monitored for the red cell fragmentation syndrome, and the catheter should be withdrawn if it develops. White cell fragmentation was also seen in one patient.- - - - - - - - - - ranking = 0.5keywords = vessel (Clic here for more details about this article) |
4/6. Systemic angioendotheliomatosis presenting with hemolytic anemia.Two patients with systemic angioendotheliomatosis had prominent constitutional symptoms such as fever, loss of weight, and general weakness, and had multiple organ dysfunctions, including bizarre neurologic findings and dementia. Severe anemia that required frequent blood transfusions also was present. One patient developed severe hemolysis and hypersplenism that required splenectomy for relief; the other patient had intravascular hemolysis and autoimmune hemolytic anemia, which were treated unsuccessfully with conservative measures. In both cases, postmortem examination showed many large, noncohesive malignant cells within the lumen of the blood vessels in many of the organs. There was no infiltration or replacement of the normal tissues by the tumor cells. Histochemical studies showed that the tumor cells were pyroninophilic but did not have cytoplasmic immunoglobulins or activity of chloroacetate esterase and muramidase. The cells showed factor viii antigen in their cytoplasm. Systemic angioendotheliomatosis may represent a true neoplastic process of the vascular endothelial cells.- - - - - - - - - - ranking = 0.5keywords = vessel (Clic here for more details about this article) |
5/6. exercise-induced hemolysis in sickle cell anemia: shear sensitivity and erythrocyte dehydration.We describe a steady-state patient with sickle cell anemia (SS disease) who developed sporadic hemoglobinuria, historically related to vigorous exercise. We studied him and four other patients with SS disease and demonstrated exercise-induced hemoglobinemia. To see if SS erythrocytes were abnormally fragile when exposed to shear forces that could be generated in small vessels of exercising muscles, we exposed them to physiologic shear rates in a cone-plate viscometer. We show that SS erythrocytes are more shear sensitive than normal erythrocytes. This phenomenon is directly related to the presence of dehydrated cells as demonstrated by the increasing shear sensitivity of increasingly dehydrated cells separated on Stractan density gradients. Normal shear sensitivity could be restored to dehydrated layers by restoring normal hydration. Restoration of shear stability was complete in all layers except for the most dense ISC layer. A control group of patients with SC disease exhibited no exercise-induced hemoglobinemia, no abnormal shear sensitivity of whole blood, and only rare dehydrated ISCs. These studies suggest that the exercise-induced hemolysis in SS patients is related to the lysis of dehydrated, shear-sensitive cells. This same process may also contribute to the chronic hemolysis of SS disease--a phenomenon known to correlate with the numbers of dehydrated ISCs.- - - - - - - - - - ranking = 0.5keywords = vessel (Clic here for more details about this article) |
6/6. exercise-induced hemolysis in xerocytosis. Erythrocyte dehydration and shear sensitivity.A patient with xerocytosis was found to have swimming-induced intravascular hemolysis and shortening of erythrocyte life-span. In a microviscometer, xerocytes were more susceptible than normal erythrocytes to hemolysis by shear stress. Fractionation of normal and abnormal cells on discontinuous Stractan density gradients revealed that increasingly dehydrated cells were increasingly more shear sensitive. This sensitivity was partially corrected by rehydrating xerocytic erythrocytes by means of the cation-ionophore nystatin in a high potassium buffer. Conversely, normal erythrocytes were rendered shear sensitive by dehydrating them with nystatin in a low potassium buffer. This effect of dehydration was entirely reversible if normal cells were dehydrated for less than 4 h but was only partially reversed after more prolonged dehydration. It is likely that dehydration of erythrocytes results in shear sensitivity primarily because of concentration of cell contents and reduced cellular deformability. With prolonged dehydration, secondary membrane changes may potentiate the primary effect. This increased shear sensitivity of dehydrated cells may explain atraumatic exercise-induced hemolysis in xerocytosis as cardiac output is shifted to vessels of exercising muscles with small diameters and high shear rates.- - - - - - - - - - ranking = 0.5keywords = vessel (Clic here for more details about this article) |