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Query: UMLS:C0039730 (thalassemia)
 10,305 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Oxygen free radicals and other oxygen derived species (Superoxide, O2-; Hydroperoxide, HOO; Singlet oxygen, 1O2-; Hydroxyl radical, OH; and Hydrogen peroxide, H2O2) including lipid peroxides have been suggested as important causative agents of aging and several human diseases, including cancer, multiple sclerosis, Parkinson's disease, autoimmune disease, ischemia, anemia, senile dementia, asbestosis and in thalassemia. This paper aims to communicate some of the theories and rationales in aging process and thalassemia.
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PMID:Role of lipid peroxidation and antioxidants in aging process and thalassemia. 134 11

The possibility that myocardial ischemia may be associated with chest pain during painful crises was evaluated prospectively in 20 patients (11 women and nine men) with sickle cell disease (19 SS, 1 S beta + thalassemia). Sixteen of 20 (80%) had abnormal ECGs, 7 (35%) had transient ST-T wave changes, and 3 (15%) had persistent ST-T wave changes, both consistent with ischemia; 6 (30%) had nonspecific ST-T changes, and 4 (20%) had normal tracings. Serum enzymes (CK, SGOT, LDH) were abnormal in 16 of 19 (84%); 1 had CK-MB detected, (5%) and 1 had LDH1 to LDH2 reversal. All 10 Tc-99m pyrophosphate scans performed were negative; 4 of 6 (66%) thallium-201 scans had focal defects, and 5 of 8 (63%) radionuclide angiograms (MUGAs) had focal wall motion abnormalities. Three of 8 (38%) MUGAs showed cardiac dilation, diffuse hypokinesis, and reduced ejection fractions. Thus, myocardial damage may be a potentially serious complication of patients with sickle cell anemia who present with chest pain during painful crises. Studies are indicated to define the significance and pathophysiology of these observations.
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PMID:Sickle cell anemia: does myocardial ischemia occur during crisis? 203 80

Disorders of hemoglobin synthesis affect the musculoskeletal system by either causing replacement of bone by hematopoietic tissue, precipitating bone and soft tissue ischemia and necrosis, or a combination of both processes. Less frequently, joints are involved by synovial ischemia, synovial deposition of iron, or microfracture of subchondral bone. Osteopenia is a significant problem in both thalassemia and sickle cell anemia and may result in vertebral and long bone fractures. Growth disturbances are frequently seen but are not often appreciated until adolescence because of improved hematologic management. The cause of the growth problems is multifactorial and may be related to hormonal deficiencies, iron overload, hypoxia, or local trauma to the growth plate secondary to significant osteopenia.
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PMID:Musculoskeletal problems in hemoglobinopathy. 229 57

With the technique of laser-Doppler velocimetry, cutaneous blood flows in the forearm of patients with stable sickle cell disease after graded periods of proximal ischemia were compared with normal subjects matched for age, race, and sex, and with patients with anemia caused by beta(+)-thalassemia. In the sickle cell patients the reactive hyperemia was characterized by an increased time interval between the release of the occlusion and the peak amplitude response (time-to-peak) and by a greater period of blood flow above the base-line value (payback ratio) compared with controls. In addition, prolongation of the occlusion period led to an augmentation in the magnitude of the characteristic basal flow oscillations or an induction of this phenomenon at sites not exhibiting it before ischemia. Base-line or ischemia-provoked flow oscillations of either this magnitude or frequency were only observed in normal or thalassemic controls during brief intervals in the rapidly decaying portion of the hyperemic response and in one subject with homozygous hemoglobin C disease. These results would support a model of a local integrative control of microcirculatory blood flow, which appears to become augmented, synchronized, and sustained in sickle cell subjects.
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PMID:Microcirculatory adaptations in sickle cell anemia: reactive hyperemia response. 240 12

40 patients with ischemic heart disease were studied. In 60% of them a higher content of HbA2 was found. These data for higher frequency of HbA2 among the patients with ischemic heart disease do not correspond with the average incidence of the genetically determined anomaly A2-beta-thalassemia among the Bulgarian population. The negative data for increased methemoglobin, the shift of the oxygen dissociation curve to the right toward increased oxygen release from the hemoglobin molecule, the normalization of HbA2 after several days, the lack of anomalous fraction in the analyses lead to the conclusion that HbA2 plays a compensatory role in patients with ischemic heart disease and its dynamic changes could be used as a diagnostic test for ischemia.
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PMID:[Changes in the hemoglobin A2 level of patients with ischemic heart disease]. 247 9

In this review the chemistry and formation of oxygen radicals is surveyed. Various physiological protective mechanisms against oxygen radicals as well as the consequence of too much or too little oxygen radicals in diseases is discussed. In this respect attention is given to hypoxia/ischemia, bronchopulmonary dysplasia, retrolental fibroplasia, thalassaemia, Down's syndrome and chronic granulomatous disease. Finally some new developments in pharmacotherapeutic possibilities which might play a role in prevention or amelioration of free radical pathologies are mentioned.
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PMID:[Oxygen radicals: rescue or threat?]. 255 29

The incidence of aseptic necrosis of femoral head in homozygous beta-thalassaemia (Cooley's anaemia)--which is indeed significantly high--is not satisfactorily referred in late literature regarding haemolytic syndromes. Therefore, 4 cases of osteonecrosis of femoral head, recently recognized in a series of 280 patients affected by Cooley's anaemia (14.5 0/00) are presented, and a review of hypotheses about the pathogenesis of the lesions is considered. In Cooley's anaemia, the skeletal lesion (osteoporosis) must be believed as a propitious state, in which some other pathogenetic events (i.e. local ischemia, bony age, etc.) and microtraumas overlap. In any case, characteristic blood circulation of the femoral head is the "conditio sine qua non" in developing osteonecrosis.
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PMID:[Aseptic necrosis of the head of the femur in Cooley's disease]. 370 10

Over the past 28 years, 39 patients with Moyamoya disease or syndrome defined as spontaneous occlusion of the circle of Willis with extensive basal collateral vessels have been treated by the author in Canada and the USA. All patients presented with clinical or radiologic evidence of hemorrhage (23) or ischemia and infarction (16). A total of 12 patients had associated cerebral aneurysms and seven of these patients with aneurysms presented with subarachnoid hemorrhage. The patients ages ranged from 5 to 47 years. Of these 58% were female. The patients racial origin included North American Indian, Innuit, East Indian/Pakistani, Japanese, Chinese, Filipino, Korean, Malayasian, Hispanic, African American and Caucasian. Familial clustering was seen in North American Indian, Innuit and Caucasian patients. Associated disorders (tuberculosis, pharyngitis, thalassemia, fibromuscular hyperplasia, polycystic kidney, sickle cell trait and hypertension) were common in these patients, as was the use of tobacco, alcohol and in the adult females, oral contraceptives. It may be concluded from this series that the etiology of Moyamoya disease or syndrome is probably multifactorial, but that some racial and familial groups are more susceptible. Furthermore, in that the clinical and angiographic features are identical, the separation between Moyamoya disease and syndrome may not be helpful in understanding the etiology and pathophysiology of this disorder.
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PMID:Risk factors of moyamoya disease in Canada and the USA. 940 4

It is known that a blood transfusion is necessary for survival in patients with thalassemia, but it may cause myocardial dysfunction due to myocardial siderosis as in other organs. The aim of this study was to evaluate myocardial perfusion by means of stress thallium scanning (MPS) and left ventricular functions by rest radionuclide ventriculography (RNV). Twenty-one patients at ages 9-16 (mean 12.1 +/- 3.2) who have been diagnosed with thalassemia for 4-15 years (mean 12.7 +/- 4.8) were included in the study. They had blood transfusions 78-318 times (mean 162.1 +/- 71). MPS and RNV was performed within two days after the any transfusion. MPS showed ischemia in 3 patients and normal perfusion in 18 patients. RNV revealed normal systolic parameters (wall motion, EF, PER, TPE) but diminished diastolic parameters (TPF, PFR) compared with normal values (p < 0.05). We conclude that ischemia or fixed defects may be seen in stress MPS as a result of cardiac involvement in patients with thalassemia. But, RNV is an important and preferable test for the early detection of subclinic cardiomyopathy. RNV may therefore show diastolic abnormalities before the systolic abnormalities show up.
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PMID:Evaluation of cardiac functions in patients with thalassemia major. 1043 78

The release of free, reactive iron from cellular iron stores has been implicated as an important contributor to tissue damage in a variety of clinical situations, including ischemia and reperfusion injury, hemorrhagic shock, and burn injury. Deferoxamine mesylate (DFO), the only iron chelator currently approved for clinical use, is used for the treatment of iron overload, including acute iron poisoning and treatment of chronic iron overload in transfusion-dependent anemias such as beta-thalassemia. However, it is not suitable for acute care situations because of its toxicity, primarily hypotension when given at high intravenous doses, and its short plasma half-life. We have produced a high-molecular-weight iron chelator by chemically coupling DFO to hydroxyethyl starch. This novel chelator (HES-DFO) was administered to healthy male subjects by intravenous infusion over a 4-hour period. The drug was well tolerated, and signs of DFO acute toxicity were not observed. Maximum plasma chelator levels of approximately 3 mmol/L were achieved with HES-DFO, which is more than an order of magnitude higher than has been reported with injections of DFO. Drug residence time in plasma was markedly prolonged, with an initial half-life of 22 to 33 hours. Urinary iron excretion was 7.1 +/- 2.2 mg in 48 hours in the highest dose group, as compared with 0.06 +/- 0.15 mg in control subjects who received normal saline infusions. Intravenous infusion of HES-DFO is well tolerated, produces substantial and prolonged plasma chelator levels, and markedly stimulates urinary iron excretion.
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PMID:First human studies with a high-molecular-weight iron chelator. 1063 95


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