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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The circadian variation of major cardiovascular disorders, that is, TMI, AMI, SCD, and stroke, reflects an increased vulnerability to myocardial and cerebral ischemia and myocardial dysfunction in the early hours of the morning after awakening and rising. A comprehensive approach to treatment in patients with ischemic heart disease must take into consideration the chronobiology of the cardiovascular system and its relevance to the underlying disease process that affects the cardiovascular system.
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PMID:Circadian influence on coronary events. 341 71

Regional cerebral blood flow, blood volume, fractional oxygen extraction and oxygen consumption were measured by positron emission tomography in six patients with sickle cell disease to see how oxygen delivery to the brain is maintained in the presence of both anemia and a low oxygen affinity hemoglobin. Both regional cerebral blood flow and blood volume were found to be markedly increased compared to values obtained from 14 normal subjects in the same age range. The mean fractional oxygen extraction was not significantly different in the two groups. Mean oxygen consumption in the two groups was also not significantly different but low values in individual patients with sickle cell disease and the presence of atrophy on the CT-scans of three of them were suggestive of some neuronal loss in patients without any history of nervous system involvement. In view of the known high values of cerebral blood flow and metabolism in childhood, it is suggested that when compounded by anemia and abnormal red cells, a hypercirculatory state may make patients in this age-group particularly prone to ischemic infarction.
Stroke
PMID:Measurement of regional cerebral blood flow, blood volume and oxygen metabolism in patients with sickle cell disease using positron emission tomography. 348 6

The cause of stroke in a young adult can usually be ascertained with proper workup. One of the most common causes is atherosclerotic cerebrovascular disease, and cigarette smoking is an important risk factor in young adults. Several types of nonatherosclerotic cerebral vasculopathy can also result in premature cerebral infarction; these include cervicocephalic arterial dissection, nonpenetrating traumatic arterial disease, moyamoya disease, fibromuscular dysplasia, vasculitis, and migraine. Cardiac embolism may play a more important role than was previously thought, and hematologic disorders (eg, sickle cell disease, polycythemia rubra vera, coagulation problems) are known to predispose patients to stroke. A careful history of risk factors and a thorough neurologic and cardiovascular examination followed by adequate testing, including angiography, are essential to diagnosis.
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PMID:Diagnosis of stroke in young adults. 356 68

A 28-year-old woman with sickle cell anemia suffered a left hemispheric cerebrovascular accident associated with severe right-sided weakness during a delayed hemolytic transfusion reaction owing to anti-rh' (C) and anti-S. The anti-rh' (C) had been identified four years earlier at a different hospital but neither the patient, her family, nor any member of the staff of the hospital where she was transfused was aware of this information. It is postulated that spherocytes, formed during hemolysis, could slow capillary flow, thereby increasing red cell sickling and producing vaso-occlusion. The patient had no clinically apparent neurologic complications during the preceding 24 years and has had no further neurologic events during the subsequent 20 months. This patient's reaction underscores the compelling need for sensitive pre-transfusion tests as well as the obligation to inform patients and their families of the presence and potential consequences of alloantibodies in the event of future transfusion.
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PMID:Cerebrovascular accident during a delayed hemolytic transfusion reaction in a patient with sickle cell anemia. 371 83

The use of chronic transfusions in patients with sickle cell disease is now the common practice after a stroke has occurred, in order to prevent the highly probable recurrence. Clinical studies show that chronic transfusion prevents the recurrence of a stroke. Review of the natural history of sickle cell disease indicates, however, that the mortality and morbidity associated with hemoglobin SS disease are quite high. Use of chronic transfusion, given before the occurrence of stroke and other irreversible organ damage, can be considered as an alternative to the conservative management of sickle cell disease. Chronic transfusion has become practicable since the recent advances in chelation therapy have essentially eliminated the risk of secondary iron overload.
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PMID:Chronic transfusions in patients with sickle cell disease. Indications and problems. 403 43

Modern contraceptive methods are discussed, with special emphasis on oral contraceptives, which are regarded as the most effective. They are also regarded as generally safe, although there are contraindications and the drugs should only be prescribed after careful examination. The need for selecting the drug most suitable for the individual patients, mainly on the basis of the characteristics of the menstrual cycle (suggesting a predominance of estrogen or progestin, within safety limits, such as 50 mcg of estrogen), is emphasized. The examinations required include a general clinical, gynecological, and breast examination, cytology tests, evaluation of the menstrual flow pattern, measurements of arterial pressure, weight, glucose, cholesterol and triglyceride levels, and urine tests. They should be repeated at 6-month intervals, or 3-month intervals in the case of high-risk patients (varicose veins, obesity, heavy smokers, high cholesterol and triglyceride levels, history of jaundice, slight heart condition, clinical or potential diabetes, porphyria or predisposition to uterine myoma). Oral contraceptives are contraindicated in cases presenting a history of thromboembolism, phlebitis, cerebral apoplexy; sickle cell anemia, which indicates a predisposition to thromboembolic accidents; serious liver disease or recent hepatitis; serious heart disease; hormone-dependent neoplasia (breast cancer); predisposition to uterine cancer; erythematous lupus; metorrhagia of unknown origin; psychic disorders, especially of a depressive type. They should also be avoided for 3-4 years after puberty, in order to avoid interfering with the development of the hypothalamus and with growth. A carcinogenic effect of the pill and an increase in the risk of giving birth to abnormal children can be ruled out, although the incidence of abortions due to chromosome anomalies after suspending treatment is rather high (due to the previous inhibition of ovulation, a situation similar to repeated pregnancies at short intervals, which involve the same risk).
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PMID:[Current clinical problems of contraception]. 502 53

Persons with sickle cell anemia who have elevated fetal hemoglobin or lowered erythrocyte mean corpuscular volume are reputed to have less severe clinical manifestations and a greater probability of survival. This study examines the relationship between seven clinical indicators of morbidity in sickle cell anemia and seven hematological parameters that were collected from 214 patients. Risks of sickle cell crisis, acute chest syndrome, hospital admissions, cerebrovascular accident, aseptic necrosis, meningitis/septicemia, and death were used as indicators of morbidity. The hematological parameters included percent fetal hemoglobin, absolute fetal hemoglobin, percent hemoglobin A2, hemoglobin concentration, packed cell volume, mean corpuscular volume, and mean corpuscular hemoglobin concentration. Statistical analyses of the data showed no relationship between the hematological parameters and six of the seven clinical indicators of the severity of sickle cell anemia. The only significant finding was an increased risk of stroke in those patients with lower levels of fetal hemoglobin. Therefore, with this exception, there is no predictable relationship between morbidity and mortality in sickle cell anemia and levels of fetal hemoglobin or erythrocyte indices. Thus, the general belief that there is an association between severity of sickle cell anemia and the levels of fetal hemoglobin has not been established.
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PMID:Lack of influence of fetal hemoglobin levels or erythrocyte indices on the severity of sickle cell anemia. 615 92

When the clinical manifestations of 272 patients with sickle cell anemia are compared with their level of fetal hemoglobin (HbF), the results suggest that there may be a threshold above which HbF is effective in ameliorating the morbidity of this disease. The age of entry of these SS patients into the study ranged from birth to 56 yr; the average length of follow-up was 11 yr for a total of 3,011 patient-years of clinic observation. HbF was determined quantitatively by microchromatographic procedures; the mean for HbF was 10% +/- 6% with a range from 2% to 32%. For major organ failure, analyzed as termination events of morbidity, such as stroke or aseptic necrosis, the threshold appears to be 10%, whereas for recurrent clinical events, such as crisis or pulmonary disorders, it is 20%. No linear trend was found between HbF levels and morbidity. If a threshold exists, it is important to recognize this fact when attempts are made to raise the level of HbF in patients with sickle cell disease.
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PMID:Is there a threshold level of fetal hemoglobin that ameliorates morbidity in sickle cell anemia? 620 Jan 61

The indications and management of blood transfusion in the haemoglobinopathies have been reviewed. The sickle cell diseases that require transfusion support are sickle cell anaemia, sickle haemoglobin-C and -D diseases and sickle beta-thalassaemia. Homozygous beta-thalassaemia (Cooley's anaemia) is the major problem among the thalassaemias. The pathophysiology of the sickle cell disorders is largely based on the secondary effects of increased blood viscosity, whereas in the thalassaemias the defect is ineffective haematopoiesis. In the former the major problems occur as manifestations of vaso-occlusive crises with disseminated bone and abdominal pain, priapism, stroke and leg ulcers. Bone infarction and aseptic necrosis occur but the widespread bone changes, underdevelopment and haemochromatosis that complicate the thalassaemia are not prominent. Transfusion therapy in the sickle cell diseases is mainly episodic and is guided by the frequency of crises and the severity of vaso-occlusive complications. Partial exchange transfusion and the maintenance of haemoglobin A concentrations at 40 to 50 per cent is frequently indicated. In the thalassaemias, maintenance of haemoglobin levels is essential for normal growth and development. The problem of haemochromatosis is very serious. With hypertransfusion regimens the haemoglobin and haemotocrit are maintained above 12-13 g/dl and 35 per cent. The resulting benefit appears to be reduced blood volume, less iron turnover, and less intestinal iron absorption. The splenomegaly in these disorders is frequently associated with hypersplenism requiring well-timed splenectomy. Chronic and intensive chelation is necessary to prevent the ravages of iron overload. The availability of automated equipment for in vivo and ex vivo blood cell separation has brought new possibilities for improving the management of these haemoglobinopathies. It is feasible, but not as yet practical, to offer transfusions of neocytes (red cells with a mean age of 30 days) which have a 50 per cent longer survival than routine red cell preparations (mean age of 60 days). Neocytes can be prepared ex vivo from fresh routine blood donations using blood cell separator devices. The result is reduced transfusion requirements. A more recent suggestion for using the new technology is to remove the patient's oldest and most abnormal corpuscles on the basis of buoyant density and replacing them with neocytes . Thus the short-lived abnormal red cells would be removed before they could unload their iron. With automation it is possible to perform these procedures on an outpatient basis.
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PMID:Transfusion support for haemoglobinopathies. 637 80

Stroke is a relatively frequent and severe complication of sickle cell disease. We performed cerebral arteriograms in 30 patients with sickle cell disease to evaluate the cause of acute neurologic deficits and to assess the effects of transfusion therapy given for a year or more after the acute episode. Twenty-three patients with motor and speech deficits had multiple abnormalities of major cerebral arteries. The internal carotid and anterior and middle cerebral arteries showed stenosis and/or occlusion at their common junction. Irregular luminal surfaces suggested that endothelial damage and intimal hyperplasia were the basis of stroke. Prolonged transfusion therapy nearly stopped progression of stenosis and markedly decreased the irregularity of the luminal surfaces; in 4 untransfused patients, the degree of stenosis doubled and the luminal abnormalities persisted. Prior to transfusion, 90% of patients had recurrence of stroke. With transfusion therapy, only 10% of patients had recurrence despite persistent arterial abnormalities. Clinical recurrences per patient-month decreased 75-fold. The patients tolerated prolonged transfusion therapy well, despite progressive iron accumulation. Seven patients with smooth abnormalities of a single artery, nonocclusive changes, or with normal arteriograms did not receive transfusions. Only one of this group had recurrence of symptoms.
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PMID:Effect of transfusion therapy on arteriographic abnormalities and on recurrence of stroke in sickle cell disease. 668 47


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