Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0002895 (sickle cell disease)
 11,747 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have studied the effect of carbamylation on hemoglobin S (HbS) polymerization with the use of a new quantitative gelling technique. HbS gels fromed in the presence of nitrogen and dithionite (with or without carbon monoxide) at pH 7 in 0.15M phosphate were separated into sol and gel phases by centrifugation at 130,000 g. Hb concentration to the sol phase ([Hb]sol) of nonligated HbS was found to be constant (10.5 +/- 092 mM heme) over a range of original Hb concentrations from 11 to 17 mM at 24degrees C. This suggests that the HbS sol-gel equilibrium behaves as simple two-phase system. Increasing levels of total carbamylation from 0.65 to 3.65 moles CNO-/mole Hb tetramer (0.36 to 2.2 moles N-terminal/mole Hb4) progressively increases [Hb]sol. Specific activity of 14CNO-HbS was similar in the sol and gel phases, whereas COHbS appeared to be completely excluded from polymer structure of the gel. A comparison of the solubility of uncarbamylated and heavily carbamylated HbS at Co saturations ranging from 3 to 61 percent showed that the larges difference in [Hb]sol occured at the lowest ligand saturation rather than at intermediate states of ligation. Inhibition of HbS polymerization by carbamylation under these conditions, therefore, is not primarily the result of an effect on the T in equilibrium R comformational equilibrium. Our findings indicate that cyanate can interfere with HbS polymerization directly, possibly by alteration of surface binding sit(s) which are critical to aggregation. This direct action of cyanate may contribute significantly to the hematologic improvement achieved by cyanate treatment in sickle cell disease.
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PMID:Mechanism of inhibition of hemoglobin S polymerization by cyanate. 87 May 73

A 22-year-old African male with known sickle cell anaemia was referred by a Congolese medical centre with a request to improve his poor physical condition. He was unable to walk, stand or sit because his large joints and his spine were either ankylosed or very rigid. Radiographs showed joint fusion from the third to the fifth cervical vertebrae, of both hips, of the left knee, and a bilateral osteonecrosis of the humeral head. There was no scintigraphic evidence for an active osteomyelitis (99mTc-MDP (methyldiphosphonate) bone scan, Tc monoclonal antigranulocyte scan and 99mTc sulphur colloid scan). To improve his mobility the right femoral head was resected in June 1997; 14 days later the left femoral head was resected. Four months after the resection of the right hip, a right uncemented total hip prosthesis was implanted on this side. One month later the same type of hip arthroplasty was performed on the left side. During the postoperative rehabilitation period the patient regained autonomy. We have found no previous reports of such severe and multiple joint complications in a single patient suffering from sickle cell anaemia.
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PMID:A 'made in one piece' skeleton in a 22-year-old man suffering from sickle cell anaemia. 1094 10

This is a case report of a 29-year-old Saudi male with sickle cell disease (SCD) with severe stiffness of his joints, mainly both knees and hips, secondary to complications of SCD. He was severely crippled: unable to sit, stand or walk, and was bedridden for 8 years when he was presented to us. Radiographs showed fusion of both knees and hips. There was no evidence of active osteomyelitis by Gallium scan. The patient's hemoglobin S decreased to levels below 30% by exchange transfusion. Bilateral total hip replacement, as well as unilateral total knee replacement, was carried out to improve his level of function. There is only one reported case of such severe and multiple joint complications in a single patient suffering from SCD. The increased life expectancy that medical advances have offered to the sickle-cell patients has led to the appearance of sickle-cell-related complications, which were previously only seen rarely. These complications were successfully managed and the patient was able to move and transfer using a wheel chair.
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PMID:Ankylosis of the hips and knees due to sickle cell disease. 2435 37