Clinical silent cerebral infarct (SCI) in patients with thalassemia diseases assessed by magnetic resonance imaging (MRI).

BACKGROUND: Silent cerebral infarct (SCI) could be detected on magnetic resonance imaging. It seems to be associated with the risk of stroke. Ischemic stroke has been reported in sickle cell anemia. Sickle red cell in hypoxic state associated with hypercoagulopathy is the risk factor of blood vessel occlusion leading to ischemic stroke. Hypercoagulable state has been documented in patients with beta thalassemia/Hb E disease, which their red cells are abnormal in deformity. OBJECTIVE: Explore SCI in patients with beta thalassemia/Hb E disease and provide a guideline for prevention of stroke. MATERIAL AND METHOD: Sixty-seven patients (29 males and 28 females, age 10-59 yrs, with a mean age of 31) with beta-thal/Hb E disease who were in the steady state without any neurological sign and symptom and no other associated stroke related disease such as DM, HT were included for MRI scanning. The cerebral MRI protocals were axial Flair, T2 Gre and 3DTOFMRA (3-dimension time of flight magnetic resonance angiography) of the brain. RESULTS: 67 patients (29 males and 28 females) with beta-thal/Hb E disease who were in the steady state without any neurological sign and symptom and no other associate stroke related disease such as DM, HT were included for MRI scanning. The ages of the patients were 10 to 59 years with a mean of 31 years. The abnormalities of the brain were found in 16 of 67 (24%). Most of the lesions were lacunar infarcts with varying amounts in the deep cerebral white matter. One cortical and subcortical infarct was observed with irregularity and stenosis of the intracranial vessels noted by MRA. All cases showed increased vascularity compared to the normal control subject. CONCLUSION: This preliminary prevalence of 24% of SCI in this genotype of thalassemia was higher than found in sickle cell disease (11%). It may be associated with coagulopathy and deformity of the red cell. Further study is needed.

Comparison of colorimetry and electrothermal atomic absorption spectroscopy for the quantification of non-transferrin bound iron in human sera.

This paper describes a comparison of two analytical techniques, one employing bathophenanthrolinedisulfonate (BPT), a most commonly-used reagent for Fe (II) determination, as chromogen and an electrothermal atomic absorption spectroscopy (ETAAS) for the quantification of non-transferrin bound iron (NTBI) in sera from thalassemic patients. Nitrilotriacetic acid (NTA) was employed as the ligand for binding iron from low molecular weight iron complexes present in the serum but without removing iron from the transferrin protein. After ultrafiltration the Fe (III)-NTA complex was then quantified by both methods. Kinetic study of the rate of the Fe (II)-BPT complex formation for various excess amounts of NTA ligand was also carried out. The kinetic data show that a minimum time duration (> 60 minutes) is necessary for complete complex formation when large excess of NTA is used. Calibration curves given by colorimetric and ETAAS methods were linear over the range of 0.15-20 microM iron (III). The colorimetric and ETAAS methods exhibited detection limit (3sigma) of 0.13 and 0.14 microM, respectively. The NTBI concentrations from 55 thalassemic serum samples measured employing BPT as chromogen were statistically compared with the results determined by ETAAS. No significant disagreement at 95% confidence level was observed. It is, therefore, possible to select any one of these two techniques for determination of NTBI in serum samples of thalassemic patients. However, the colorimetric procedure requires a longer analysis time because of a slow rate of exchange of NTA ligand with BPT, leading to the slow rate of formation of the colored complex.