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Query: UMLS:C0002895 (sickle cell disease)
 11,747 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Liver biopsy results and clinical records from 13 patients with sickle cell anemia were reviewed to assess the relative importance of local ischemia or of factors unrelated to sickling as a cause of their liver disease. Two of the biopsy specimens were normal and one showed cirrhosis. Nine patients had received multiple blood transfusions and nine had cholelithiasis, of whom two also had choledocholithiasis. Seven had both risk factors. Five had lobular cholestasis and four had acute or chronic hepatitis. One biopsy specimen showed changes of the Budd-Chiari syndrome. Another showed clear portal tract changes of large bile duct obstruction but no mechanical blockage of the biliary system; this suggests the thickened bile as postulated by Muirhead. Otherwise the changes observed were those to be expected in a heavily transfused population with a high prevalence of gallstones.
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PMID:Histopathologic features of liver biopsy specimens in sickle cell disease. 334 26

Hemorheologic disorders are a frequent finding in circulating blood during vascular diseases (arterial disease of lower limb, cerebrovascular accidents). They participate in thrombogenesis and tissue ischemia production, and also in microcirculatory disturbances as shown by behavior in microvessels of red cells with decreased hereditary deformability (sickle cell anemia). Active alterations in erythrocyte rheology have also been demonstrated during vascular diseases in relation to inflammation: cell-protein inflammatory reaction, action of leukocytes. Therapy should be adapted for these microcirculatory disorders by suitable specific clinical trials.
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PMID:[Hemorheologic study of different forms of vasomotor acrosyndromes]. 355 5

Direct intravital microscopic examinations were made in nailfold capillaries in subjects with homozygous sickle cell disease (HbSS red cells). In the resting state, capillary red cell (rbc) flux exhibited greater intermittence compared with normal subjects, which increased with painful crisis. In crisis-free HbSS subjects, capillary occlusion and red cell sequestration occurred in only 8.2% of all capillaries and diminished to 5.8% during crisis, possibly due to sequestration of less deformable rbcs in other organs. Velocities of rbc's (Vrbc) were measured by video techniques under resting conditions and during postocclusive reactive hyperemia (PORH) induced by a pressure cuff around the finger. Resting Vrbc was normal in crisis-free HbSS subjects, averaging 0.7 mm/s. In contrast, Vrbc was significantly elevated during crisis, to 0.98 mm/s, apparently due to compensatory arteriolar dilation. Crisis subjects exhibited a significantly depressed PORH with the ratio of peak red cell velocity to resting values reduced by 15% due to a loss of vasodilatory reserve, whereas crisis-free subjects exhibited a normal response. A 55% increase in the time to attain peak Vrbc was attributed to resistance increases, possibly resulting from red cell and leukocyte-to-endothelium adhesion during the induced ischemia.
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PMID:Intravital microscopy of capillary hemodynamics in sickle cell disease. 359 70

Although the pathophysiologic manifestations of sickle cell disease have been assumed to result from microvascular occlusion consequent to in situ sickling of erythrocytes, actual blood vessel obstruction have been rarely demonstrated in vivo. Recent observations utilizing sophisticated biophysical techniques to study the intracellular hemoglobin S polymerization process has led to major revisions in this previously held pathophysiologic paradigm, but in vivo correlations are still lacking. With the development of new noninvasive imaging and para-imaging methods, it is now technically possible and feasible to characterize both regional organ perfusion and tissue biochemistry in quantitative terms. In addition, these modalities promise to clarify pathogenesis of the disease through definition of the events responsible for the progression from tissue ischemia and infarction through the resolution phase. Since these noninvasive techniques are amenable to sequential applications, they should facilitate objective evaluations of clinical trials of therapeutic agents designed to prevent or delay the vaso-occlusive manifestations of sickle cell disease.
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PMID:Noninvasive techniques to evaluate the vaso-occlusive manifestations of sickle cell disease. 387 1

This paper describes what is thought to be the first reported use of a free flap in a patient with homozygous sickle cell disease. The utilization of a free flap in homozygous sickle cell disease should be questioned because the obligate period of ischemia to which the flap must be subjected during the transfer from donor to recipient sites might lead to intravascular sickling in the flap and flap failure. Review of the literature suggests that by reducing the level of sickle hemoglobin to the range of 25 to 40 percent, the risk of failure of a free flap is not significantly increased in the homozygous sickle cell patient. Furthermore, there is good evidence to suggest that a well-vascularized muscle flap provides optimal coverage, reversing the pathophysiologic cycle of the sickle cell ulcer. Thus in cases of multiply recurrent sickle cell ulcers in areas devoid of a local well-vascularized muscle flap, a free muscle flap is indicated, may be the procedure of choice, and can be performed successfully. We report a patient with a 4-year history of multiple recurrent sickle cell ulcers of the left ankle treated with a gracilis free flap. This patient has been followed for 2 years and continues to be free of recurrent ulceration.
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PMID:The use of a free flap in homozygous sickle cell disease. 403 81

A 6-year-old girl with sickle cell disease was admitted to the hospital with the diagnosis of the acute chest syndrome. The laboratory findings and the radionuclear lung scan supported a diagnosis of pulmonary infarction rather than pneumonia. She improved with intravenous fluids, oxygen, penicillin, and theophylline. The most likely explanation for the rapid resolution of the clinical syndrome, the chest x-ray, and lung scan abnormalities is that masses of sickled cells caused transient pulmonary vascular occlusion leading to perfusion defects and ischemia, and that the sickled cell thrombi were dislodged before the infarction occurred. To our knowledge, this phenomenon has not been described as a cause of the acute chest syndrome in sickle cell disease in children.
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PMID:Acute reversible pulmonary ischemia. A cause of the acute chest syndrome in sickle cell disease. 406 60

Blood has a number of rheological properties which partially determine flow, especially at capillary level, and its capacity to deliver oxygen. It is non-Newtonian, pseudoplastic, thixotropic and viscoelastic. Viscosity can be studied with different types of viscosimeters (coaxial cylinder or capillary viscosimeters). It can be defined by the ratio of stress of deformation to rate of deformation. Viscosity depends on macrorheological parameters: hematocrit, serum proteins, especially fibrinogen and globulins, and also on microrheological parameters: degree of aggregation and red blood cell deformability. Viscosity rises when the temperature falls and decreases with the radius of the tube through which the blood flows (Fahraeus-Linqvist effects). Blood viscosity is studied clinically at different temperatures, and, above all, at different rates of deformation by carefully recording the hematocrit. Plasma viscosity, fibrinogen, albumia and immunoglobulin levels, the viscosity of blood cell suspensions in normal saline must also be taken into consideration. Special investigations (rheoscopy, filtrability) provide information about red cell aggregation and deformability. Hyperviscosity syndromes are observed with: --raised hematocrit (polycythemia and pseudopolycythemia), --conditions with raised serum proteins or changes in their composition (especially hyperfibrinogenemia, raised immunoglobulins, low albumin levels); inflammatory syndromes, dysglobulinemias (Fahey's syndrome of plasma hyperviscosity), --low temperature (hypothermia), --increased red cell aggregability (shock, fat embolism), --reduced red cell deformability due to various congenital and acquired conditions (sickle cell anemia, renal failure, hyperlipoproteinemia, thrombosis, diabetes). Conversely, hypoviscosity may occur with a low hematocrit, hypoproteinemia, hypofibrinogenemia, and hyperthermia. Increased viscosity results in a slowing of blood flow, stagnation of its constituents and in ischemia. Therapeutic interventions may be considered on the different components of the hyperviscosity syndrome: hemodilation, plasmapheresis, dispersion of aggregants, agents acting on red cell deformability.
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PMID:[Blood hyperviscosity syndromes. Classification and physiopathological understanding. Therapeutic deductions]. 636 7

Chronic, excruciatingly painful ulcerations of the lower extremities in patients with homozygous sickle cell anemia (HbSS) present a frustrating clinical problem for the reconstructive surgeon. Despite adequate wound care and skin grafting, there is a dismally high incidence of recurrence. Furthermore, there is a paucity of reliable locoregional fasciocutaneous, muscle, and myocutaneous flaps in the ankle region. Free-tissue transfer has become the procedure of choice for reconstruction of the lower third of the leg. However, in sickle cell anemia, does the obligate period of flap ischemia inherent in free-tissue transfer inevitably doom a flap to failure? We present our multidisciplinary experience over 55 months with five free flaps in four homozygous sickle cell anemia patients 21 to 38 years old who had chronic nonhealing leg ulcerations. Special perioperative measures included exchange transfusion to lower hemoglobin S to below 30 percent, maintaining the hematocrit at 31 to 35 percent, intraoperative flap washout and perfusion with warm heparinized saline-dextran solution, administration of dextran and aspirin intraoperatively and postoperatively, prophylactic topical and systemic anti-Pseudomonas antibiotics, supplemental oxygen, and warm ambient room temperature. Flaps included the latissimus dorsi muscle (two patients), the temporoparietal fascia (one patient), and "split" omentum for bilateral lower limb salvage (one patient). Successful free-tissue transfer was accomplished in all patients. One patient suffered gradual partial occlusion of the microcirculation by sickled erythrocytes following a transient hypothermic, hypotensive episode. Sufficient flap tissue survived to permit skin grafting with an excellent result. Pseudomonas infection occurred in two patients (three flaps).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Lower limb salvage by microvascular free-tissue transfer in patients with homozygous sickle cell disease. 756 93

Infarctions of the long bones in sickle cell anemia and some of its variant hemoglobinopathies are well known. Photopenia representing areas of acute infarctions of the ilia in two young children are presented as unusual presentations of bone ischemia.
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PMID:Infarctions of the ilia in young patients with sickle hemoglobinopathies. 834 22

We performed 31P magnetic resonance spectroscopy of gastrocnemius muscle at rest in 7 normal volunteers and 12 patients with sickle cell disease (7 with leg ulcers and 5 without leg ulcers but with painful crises). We measured intracellular pH and ratios of Pi to ATP, PCr to ATP and PCr to Pi (Pi = inorganic phosphate, ATP = adenosine triphosphate, and PCr = phosphocreatine). Magnetic resonance arteriograms were also performed. Significant differences were found for PCr/Pi ratios between normals and sickle cell disease patients with leg ulcers (p < 0.008). Magnetic resonance arteriograms were normal in volunteers and patients with sickle cell disease. The altered high energy phosphate metabolism in sickle cell disease with leg ulcers is consistent with muscle ischemia or hypoxia.
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PMID:Altered muscle metabolism shown by magnetic resonance spectroscopy in sickle cell disease with leg ulcers. 842 14


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