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1.
Am J Med Genet A ; 130A(3): 299-302, 2004 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-15378535

RESUMEN

We report a girl with mild mental retardation with onset of infantile spasms at age of 9 months. Treatment with a short course of adrenocorticotropic hormone (ACTH) was successful. Initially, a diagnosis of idiopathic West syndrome, with good neurological outcome and disappearance of epilepsy after treatment, was made. Conventional karyotype was normal. Reinvestigations were done at age 8 years, because of a new pregnancy. Karyotyping of both parents was done because of mild dysmorphic features in the proband, and to eliminate other causes than early age epilepsy as the etiology of her mental retardation. Parental karyotypes showed a balanced paternal translocation (4p;17q) resulting in partial 4p trisomy, without significant 17q monosomy in the proband. Chromosomal abnormalities usually lead to a severe West syndrome with poor prognosis of neurological outcome (persistent severe epilepsy, mental retardation, and behavioral disturbances). The presence of an undetected cytogenetic anomaly in our proband with transient hypsarythmia is unusual and led us to propose systematic telomeric screening in apparently "idiopathic" West syndrome patients with mild mental retardation and subtle dysmorphic features.


Asunto(s)
Anomalías Múltiples/genética , Cromosomas Humanos Par 4/genética , Espasmos Infantiles/patología , Telómero/genética , Trisomía , Anomalías Múltiples/patología , Niño , Preescolar , Bandeo Cromosómico , Femenino , Estudios de Seguimiento , Humanos , Hibridación Fluorescente in Situ , Lactante , Discapacidad Intelectual/patología , Cariotipificación , Fenotipo , Síndrome
2.
J Fr Ophtalmol ; 26(3): 249-53, 2003 Mar.
Artículo en Francés | MEDLINE | ID: mdl-12746600

RESUMEN

INTRODUCTION: Previous studies have reported that an elevated plasma homocysteine level is a risk factor for vascular disease. The aim of this study is to determine whether hyperhomocysteinemia is a risk factor for retinal vein occlusion (RVO) and whether it is a prognostic factor. PATIENTS AND METHODS: The plasma homocysteine level was measured in 101 patients and compared to the plasma homocysteine level of controls. The relation between plasma homocysteine level and the other known risk factors of retinal vein occlusion was studied, as well as the correlation between the clinical outcome of the RVO and the plasma homocysteine level. RESULTS: The mean plasma homocysteine level was significantly higher in the 101 RVO patients than in the 29 controls (11.9 mmol/l vs 8.6, p<0.001). We found no relation between plasma homocysteine and other risk factors of vascular disease except for the hematocrit level. Hyperhomocysteinemia was more frequent in the ischemic forms and in bilateral RVO, but the difference was not statistically significant. CONCLUSIONS: Hyperhomocysteinemia seems to be an independent risk factor for RVO and was more frequent in severe RVO, but our study did not evidence an association with a severe prognosis. Vitamin therapy can decrease homocysteinemia but its efficacy in the prevention and in the treatment of RVO remains to be demonstrated.


Asunto(s)
Hiperhomocisteinemia/complicaciones , Oclusión de la Vena Retiniana/complicaciones , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores/sangre , Femenino , Homocisteína/sangre , Humanos , Hiperhomocisteinemia/sangre , Masculino , Persona de Mediana Edad , Valores de Referencia , Oclusión de la Vena Retiniana/sangre , Estudios Retrospectivos , Factores de Riesgo , Trastornos de la Visión/clasificación , Trastornos de la Visión/epidemiología
4.
J Fr Ophtalmol ; 21(4): 245-50, 1998 Apr.
Artículo en Francés | MEDLINE | ID: mdl-9759412

RESUMEN

PURPOSE: Epidemiological studies have shown a significant correlation between increased levels of lipoprotein (a) and coronary and cerebral vascular diseases. Lipoprotein (a) presents a striking homology with plasminogen and may therefore complete with binding of plasminogen at fibrin and at the endothelial cell surface, leading to fibrinolytic system dysfunction. The aim of this work is to study the relationship between increased levels of Lp(a) and retinal vein occlusion. METHODS: 132 consecutive patients with retinal vein occlusion were screened for lipoprotein (a) level. They also underwent initial and final visual acuity measurement, fluorescein angiography and blood tests including glucose, cholesterol and triglyceride levels, apolipoprotein A1 and B, protein electrophoresis, coagulation tests. Lipoprotein (a) results were compared with those of 52 age, sex and cardiovascular risk factors-matched controls. RESULTS: Lipoprotein (a) values were significantly higher in the retinal vein occlusion group than in the control group (p = 0.05). Elevated lipoprotein (a) (> 0.1 g/l) levels were observed more often in retinal vein occlusion patients (61%) than in the controls (42%; p < 0.02). No correlation was found in retinal vein occlusion patients between high levels of lipoprotein (a) and a severe form of retinal vein occlusion. Lipoprotein (a) levels were similar in central vein and branch vein occlusion patients. CONCLUSION: Lipoprotein (a) has been shown to be correlated with cardiovascular disorders and may also be involved in retinal vein occlusion, probably by dysfunction of the fibrinolytic system. However, it does not seem to be a prognostic factor of retinal vein occlusion and its role has to be elucidated in further studies.


Asunto(s)
Lipoproteína(a)/sangre , Oclusión de la Vena Retiniana/epidemiología , Adolescente , Adulto , Anciano , Unión Competitiva , Comorbilidad , Diabetes Mellitus/epidemiología , Femenino , Fibrinólisis , Glaucoma/epidemiología , Humanos , Hiperlipidemias/epidemiología , Hipertensión/epidemiología , Lípidos/sangre , Lipoproteína(a)/química , Masculino , Persona de Mediana Edad , Plasminógeno/química , Plasminógeno/metabolismo , Factores de Riesgo
5.
Ophthalmology ; 103(4): 551-60, 1996 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-8618752

RESUMEN

BACKGROUND: The prognosis of retinal vein occlusion is highly unpredictable because nonischemic types may convert into ischemic types within the first months. This study was designed to identify epidemiologic characteristics of the different types of retinal vein occlusion, their visual outcome, and their prognostic factors. METHODS: The authors analyzed prospectively the data from patients who have had retinal vein occlusion with complete medical and biologic examination, including fluorescein angiography, and a 1-year follow-up. RESULTS: One hundred seventy-five retinal vein occlusion eyes consisted of 120 central retinal vein occlusions (CRVO), 7 hemicentral occlusions, and 48 branch occlusions. In initially nonischemic CRVO eyes, retinal ischemia developed in 54%. The study of prognostic factors in the CRVO group showed that older age, male sex, and the number of risk factors (systemic vascular risk factors and glaucoma) were correlated with a poor visual outcome and with the development of retinal ischemia, as well as baseline visual acuity, initial extent of retinal ischemia, and rheologic findings (hematocrit, fibrinogen, and erythrocyte aggregation levels). Logistic regression underlined the prognostic role of sex, the number of risk factors, erythrocyte aggregation, and initial clinical features. Persistent macular edema was shown to be associated with hyperlipidemia and cardiovascular history, and inversely correlated to glaucoma. CONCLUSION: Because clinical characteristics of CRVO may worsen, the authors' results provide a basis to predict visual outcome by taking into account epidemiologic and rheologic findings. A careful follow-up of these patients is recommended.


Asunto(s)
Oclusión de la Vena Retiniana/epidemiología , Oclusión de la Vena Retiniana/etiología , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Angiografía con Fluoresceína , Estudios de Seguimiento , Francia/epidemiología , Fondo de Ojo , Humanos , Isquemia/etiología , Isquemia/patología , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Prospectivos , Oclusión de la Vena Retiniana/fisiopatología , Vasos Retinianos/patología , Factores de Riesgo , Agudeza Visual/fisiología
6.
Am J Ophthalmol ; 118(4): 421-9, 1994 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-7943118

RESUMEN

Hemorheologic factors probably play a role in the pathogenesis and prognosis of retinal vein occlusion. Accordingly, we designed a prospective, randomized, double-masked study to evaluate the effect of troxerutin, a rheologic drug, on retinal vein occlusion. Fifty-three patients were included, 27 with central retinal vein occlusion and 26 with branch retinal vein occlusion. They were randomly assigned for treatment with either troxerutin or a placebo. All subjects were similar in age, gender, associated diseases, hemorheologic values, and clinical severity of the retinal vein occlusion. At the end of follow-up, members of the troxerutin-treated group, as compared with the placebo group, showed significant improvement in visual acuity (P = .03), macular threshold (P = .01), retinal circulation times (P = .04), and macular edema (P = .05). Furthermore, they had diminished progression of ischemia (P = .05) and decreased red blood cell aggregability (P = .006) when compared with the controls. These encouraging preliminary results obtained with a rheologic treatment attest to the pathogenic role of blood viscosity in retinal vein occlusion and suggest that a large-scale randomized study should be conducted.


Asunto(s)
Anticoagulantes/uso terapéutico , Hidroxietilrutósido/análogos & derivados , Oclusión de la Vena Retiniana/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Método Doble Ciego , Evaluación de Medicamentos , Femenino , Humanos , Hidroxietilrutósido/uso terapéutico , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Oclusión de la Vena Retiniana/fisiopatología , Vasos Retinianos/fisiología , Resultado del Tratamiento , Agudeza Visual
7.
Ophthalmology ; 101(9): 1483-7, 1994 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8090451

RESUMEN

BACKGROUND: Retinal venous circulation is characterized by the combination of a low flow state and a high vascular resistance, which would make it particularly dependent on blood viscosity. Erythrocyte aggregation is the chief determinant of blood viscosity at low shear rates. Recent studies have demonstrated increased erythrocyte aggregation in many systemic vascular disorders and also in retinal vein occlusion. METHODS: To assess the possible role of abnormal hemorheologic findings in the pathogenesis of central retinal vein occlusion (CRVO), the authors retrospectively studied erythrocyte aggregation and hematocrit and fibrinogen levels in 33 patients with CRVO and without any known risk factors (diabetes, hypertension, smoking, hyperlipidemia, cardiovascular disease, glaucoma). Erythrocyte aggregation was assessed with a light back-scattering method. Results were compared with those of a group of 33 age- and sex-matched controls. RESULTS: Eleven (33%) of the 33 patients with CRVO had abnormal hemorheologic findings. Erythrocyte aggregation was highly significantly increased in the CRVO group when compared with the control group (P < 0.0001), as was the hematocrit level (P < 0.05). In addition, the proportion of patients with abnormal blood rheologic tests was greater (50%) in the subgroup of patients who initially had nonischemic CRVO that worsened into an ischemic CRVO during the follow-up. CONCLUSION: These data suggest that abnormal hemorheologic findings could affect the pathogenesis of CRVO, and perhaps be predictive of an aggravation. The latter hypothesis needs to be confirmed in a larger, prospective study.


Asunto(s)
Agregación Eritrocitaria , Oclusión de la Vena Retiniana/sangre , Adulto , Anciano , Viscosidad Sanguínea/fisiología , Femenino , Fibrinógeno/análisis , Hematócrito , Humanos , Masculino , Persona de Mediana Edad , Oclusión de la Vena Retiniana/etiología , Estudios Retrospectivos , Factores de Riesgo
8.
Arch Ophthalmol ; 112(6): 790-5, 1994 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-8002838

RESUMEN

OBJECTIVE: To assess the prevalence of antiphospholipid antibodies in patients with occlusive retinal vascular disorders. PATIENTS: Seventy-five consecutive patients (44 with central retinal vein occlusions, 24 with branch venous occlusions, five with vasculitis plus branch venous occlusion, and two with arterial occlusions) were screened for antiphospholipid antibodies and compared with a control group composed of outpatients with similar systemic vascular disorders. RESULTS: The antibody assay for one patient was positive for lupus anticoagulant and the antibody assay for three other patients was positive for anticardiolipin antibodies. These four patients had central or branch retinal vein occlusion and presented with several vascular risk factors. Comparison of the retinal vascular occlusion and the control groups showed no difference in the levels of anticardiolipin antibodies or lupus anticoagulant. CONCLUSIONS: Antiphospholipid antibodies did not seem to be a feature of retinal vein occlusion, but in rare cases (5%) they may contribute to the occlusive phenomenon. A systematic screening does not seem to be justified, but it may be valuable to test for antiphospholipid antibodies in patients without conventional risk factors and in patients with clotting screen abnormalities, particularly if associated with lupus-like syndrome or other elements of the primary antiphospholipid syndrome.


Asunto(s)
Anticuerpos Anticardiolipina/análisis , Inhibidor de Coagulación del Lupus/análisis , Oclusión de la Arteria Retiniana/inmunología , Oclusión de la Vena Retiniana/inmunología , Adulto , Anciano , Síndrome Antifosfolípido/inmunología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Estudios Prospectivos , Factores de Riesgo
9.
Br J Haematol ; 86(1): 195-7, 1994 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8011530

RESUMEN

We report the clinical presentation and the morphological, immunophenotypic, cytogenetic and molecular genetic characteristics of a 14 1/2-year-old boy who had French-American-British (FAB) type M1 acute non-lymphocytic (ANLL) leukaemia with a common T-ALL immunological phenotype, with no myeloid associated antigen, either on the membrane or in the cytoplasm. ALL-directed induction therapy induced complete remission.


Asunto(s)
Células Madre Hematopoyéticas/inmunología , Leucemia Mieloide Aguda/inmunología , Peroxidasa/análisis , Linfocitos T/inmunología , Adolescente , Antígenos CD/análisis , Antígenos de Neoplasias/análisis , Humanos , Inmunofenotipificación , Leucemia Mieloide Aguda/clasificación , Leucemia Mieloide Aguda/enzimología , Leucemia Mieloide Aguda/patología , Masculino
10.
Environ Pollut ; 75(2): 223-8, 1992.
Artículo en Inglés | MEDLINE | ID: mdl-15092037

RESUMEN

Chemical budgets are presented for three small granitic catchments in Southeastern France, with contrasting vegetation type: beech coppice; spruce forest; and grassland. The results show a small net loss of cations, and a large accumulation of sulphur in the soil, which acts as an additional proton sink. Significantly higher weathering rates are observed for the conifer catchment. Clearfelling of the spruce forest, late in the monitoring programme, increased net cation and nitrate losses. The importance of dry atmospheric deposition in the input-output budget, particularly for forests, is highlighted.

11.
Am J Obstet Gynecol ; 165(1): 51-6, 1991 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-1853915

RESUMEN

Lupus anticoagulant, anticardiolipin, antinuclear, anti-deoxyribonucleic acid, antithyroglobulin, and antithyroid microsomal antibodies were assayed during third-trimester pregnancy (100 normal, 100 with complications). In spite of a normal activated partial thromboplastin time in all instances, lupus anticoagulant was further investigated by three additional procedures: tissue thromboplastin inhibition time, platelet neutralization procedure, and cephalin neutralization test. The prevalence of autoantibodies in pregnancies with hypertension reaches 16% (four with lupus anticoagulant, two with anticardiolipin, and two with antithyroid microsomal antibodies), which is significantly greater than that for idiopathic fetal growth retardation (2%) (one with lupus anticoagulant antibodies) and normal pregnancies (3%) (two with antithyroglobulin and one with autithyroid microsomal antibodies) (p less than 0.01). Autoantibodies were equally distributed between patients with gestational hypertension and those with preeclampsia. When compared with the 42 patients with hypertension and no autoantibodies, the eight patients with autoantibody had a more frequent history of fetal growth retardation (p less than 0.05), but there was no difference in the severity of hypertension, the frequency of obstetric complications, or the outcome of pregnancy. They did not require any specific treatment.


Asunto(s)
Autoanticuerpos/análisis , Retardo del Crecimiento Fetal/inmunología , Hipertensión/inmunología , Complicaciones Cardiovasculares del Embarazo , Embarazo/inmunología , Pruebas de Coagulación Sanguínea , Femenino , Humanos , Embarazo/sangre , Tercer Trimestre del Embarazo , Valores de Referencia
12.
Am J Med ; 90(3): 381-5, 1991 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-1848396

RESUMEN

The first known case of systemic mast cell disease associated with a germ cell tumor is reported. Six months after the complete remission of a primary mediastinal germ cell tumor treated by chemotherapy and resection, a young man had a series of episodes of hypotension and syncope and, a few months later, a gastric hemorrhage and coagulation disorder. The diagnosis of systemic mast cell disease was made in view of bone marrow and liver biopsies. A transient circulating heparin-like anticoagulant was noted. The occurrence in a short period of these two unusual conditions, given previous knowledge of hematologic disorders associated with germ cell tumors, suggests that the present association is not a coincidence. Systemic mast cell disease should be considered among the hematologic disorders associated with a germ cell tumor.


Asunto(s)
Mastocitosis/complicaciones , Neoplasias del Mediastino/complicaciones , Neoplasias de Células Germinales y Embrionarias/complicaciones , Adulto , Humanos , Masculino
13.
Br J Haematol ; 75(1): 127-31, 1990 May.
Artículo en Inglés | MEDLINE | ID: mdl-2375911

RESUMEN

Reversible aggregation of red blood cells (RBC) plays an important role in determining the flow properties of blood, and is the cause of the increase in blood viscosity at low shear rates. Retinal venous circulation is characterized by the combination of a low flow state and a high vascular resistance which might severely limit its capacity to adjust to high blood viscosity. These characteristics make the venous circulation in the retina particularly dependent on haemorheological factors. To test the possibility that high RBC aggregation could predispose to the onset and development of retinal vein occlusion (RVO), RBC aggregation and disaggregation (SEFAM erythroaggregameter, France) were measured in 64 patients with RVO. Results were compared to those of a group of 64 controls, similar in age, sex, smoking habit and associated pathologies. Increased RBC aggregation was observed in 52% of the patients, and the mean values showed a highly significant elevation of RBC aggregation parameters in RVO patients (+14%) when compared with controls (P less than 0.001). Subgroups were compared to study the influence of site (central versus branch), form (ischaemic versus non-ischaemic), duration and severity of the occlusion on the aggregation parameters. No significant differences were found between these various subgroups. An increase in RBC aggregability and in the shear resistance of RBC aggregates, by predisposing to circulatory stasis, is likely to contribute to the onset of RVO.


Asunto(s)
Agregación Eritrocitaria/complicaciones , Oclusión de la Vena Retiniana/etiología , Adulto , Anciano , Anciano de 80 o más Años , Proteínas Sanguíneas/análisis , Femenino , Fibrinógeno/análisis , Humanos , Masculino , Persona de Mediana Edad , Oclusión de la Vena Retiniana/sangre , Factores de Riesgo
14.
J Fr Ophtalmol ; 13(10): 500-5, 1990.
Artículo en Francés | MEDLINE | ID: mdl-2081840

RESUMEN

Erythrocyte aggregation is one of the principal determinants of blood viscosity at low shear rates (low flow). Anatomical and hemodynamical characteristics make retinal venous circulation particularly dependent on hemorheological factors. Erythrocyte aggregation and other laboratory parameters (haematocrit, fibrinogen, plasma proteins, clotting) were measured in 85 patients presenting with retinal vein occlusion and 64 controls matched for age, sex and vascular risk factors (hypertension, diabetes, smoking). Statistical analysis of the results demonstrated a significant difference between the retinal vein occlusion group an the control group for erythrocyte aggregation (p less than 0.001 for the aggregation index at 10 sec and for the threshold of dissociation). The fibrinogen level, haematocrit and plasma proteins (albumin, IgA, IgG, IgM, total proteins, 2-macroglobulin) were similar in the two groups. No statistically significant difference for erythrocyte aggregation was observed between occlusions of the venous branch and occlusions of the central retinal vein or between ischaemic and non-ischaemic forms. These results suggest that raised erythrocyte aggregation mainly explains the increase in blood viscosity previously demonstrated, and could play a role in the constitution of retinal vein occlusion.


Asunto(s)
Agregación Eritrocitaria , Oclusión de la Vena Retiniana/sangre , Enfermedad Aguda , Adulto , Anciano , Anciano de 80 o más Años , Viscosidad Sanguínea , Enfermedad Crónica , Femenino , Humanos , Isquemia/sangre , Masculino , Persona de Mediana Edad , Pronóstico , Vasos Retinianos , Factores de Riesgo , Factores de Tiempo
15.
Bull Soc Ophtalmol Fr ; 89(12): 1393-6, 1989 Dec.
Artículo en Francés | MEDLINE | ID: mdl-2632113

RESUMEN

Erythrocyte aggregation (EAg) is one of the principal determinants of blood viscosity at low shearing rates (slow flow). The retinal venous circulation, characterised by a slow circulatory rate and a high resistance to flow, creates a favourable environment for the formation of erythrocyte aggregates. EAg and other laboratory parameters (haematocrit, fibrinogen, plasma proteins, clotting) were measured in 64 patients presenting with retinal vein occlusion (RVO) and 64 controls matched for age, sex, risk factors (HT, diabetes, smoking) and concomitant vascular disease. Statistical analysis of the results demonstrated a significant difference between the RVO group and the control group for fibrinogen (p = 0.03) and erythrocyte aggregation (p = 0.00003 for the aggregation index at 10 sec and p = 0.0002 for the threshold of partial dissociation). The rise in the fibrinogen level alone cannot explain the increased erythrocyte aggregation. These results demonstrate that the increased EAg largely explains the hyperviscosity reported by other authors and suggest that it plays an important role in the pathogenesis of RVO.


Asunto(s)
Agregación Eritrocitaria , Oclusión de la Vena Retiniana/sangre , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Fibrinógeno/análisis , Humanos , Masculino , Persona de Mediana Edad
16.
Rev Med Interne ; 8(2): 157-62, 1987.
Artículo en Francés | MEDLINE | ID: mdl-3296077

RESUMEN

Three anti-native DNA antibody detecting assays were compared using sera from 948 patients with clinical symptoms of connective tissue disease and 55 definite systemic lupus erythematosus patients. The Farr assay was more effective than the two other assays in the diagnosis of lupus. Anti-DNA antibody detection by ELISA was as sensitive as the Farr assay; in contrast indirect immunofluorescence on Crithidia luciliae had a significantly lower sensitivity, detecting less than one out of two cases of lupus detected. Particularly ELISA but also indirect immunofluorescence may give positive results in the absence of lupus, so that results obtained by each of these assays must be confirmed by the Farr assay if they are used in the diagnosis of lupus. The significance of antibodies detected by one assay but not by the others is discussed.


Asunto(s)
Anticuerpos Antinucleares/análisis , ADN/inmunología , Lupus Eritematoso Sistémico/inmunología , Crithidia , Ensayo de Inmunoadsorción Enzimática , Técnica del Anticuerpo Fluorescente , Humanos
18.
Int J Biomed Comput ; 12(6): 483-501, 1981 Nov.
Artículo en Francés | MEDLINE | ID: mdl-7319665

RESUMEN

Transport of energy appears as the ultimate finality of the force convection cardiovascular system. Blood pressure cardiac output and vascular resistances are the three major components of the circulatory system. Among them, blood pressure is regarded as the regulated parameter whose control value is the best adapted parameter, to each kind of activity, neurogenic mechanisms. The authors, considering the physiological variations of blood pressure during increasing energetic loads imposed on the organism, propose a new control function: optimization of cardiac mechanical power necessary to assure convection of the energy needed by the organism. Blood pressure is no more regarded as a constant. Simultaneous changes in cardiac output and blood pressure are both significant, adjusted to realize energetic minimisation of the cardiac pump. This cardiovascular regulation is described by a system of equations whose resolution leads to results in good accordance with physiological data.


Asunto(s)
Computadores , Corazón/fisiología , Hemodinámica , Adaptación Fisiológica , Presión Sanguínea , Gasto Cardíaco , Metabolismo Energético , Humanos , Resistencia Vascular
19.
Nouv Presse Med ; 9(43): 3253-7, 1980 Nov 15.
Artículo en Francés | MEDLINE | ID: mdl-7454569

RESUMEN

Anti-red auto-antibodies were found in 69 out of 892 000 blood donors aged between 20 and 60 years, 63 of whom were followed for up to five years. This would suggest an overall incidence of 1 in 13 000 members of a "normal" population. Uncontrolled methyl-dopa treatment could be incriminated in 25% of cases. Only 10% of autoimmune subjects had slight confirmed anaemia, but 72% had biological evidence of red cell destruction (i.e. hyper-reticulocytosis, elevated serum bilirubin levels and shortened red cell life span), which demonstrates the presence of subclinical autoimmune haemolytic disease in apparently normal people. The anti-red cell auto-antibodies were of the IgG type in 97% of the subjects and were associated with various anti-tissue antibodies in 41%, thus pointing to a multisystem autoimmune disorder. In most cases the abnormality persisted or spontaneously regressed during the observation period, but long-term follow-up is required to determine whether asymptomatic red cell autoimmunization is harmless or potentially dangerous.


Asunto(s)
Autoanticuerpos/análisis , Eritrocitos/inmunología , Adulto , Anemia Hemolítica Autoinmune/etiología , Donantes de Sangre , Prueba de Coombs , Femenino , Hemólisis , Humanos , Inmunoglobulina G/análisis , Masculino , Metildopa/efectos adversos , Metildopa/uso terapéutico , Persona de Mediana Edad
20.
Int J Biomed Comput ; 9(4): 287-300, 1978 Jul.
Artículo en Francés | MEDLINE | ID: mdl-689770

RESUMEN

The purpose of this pulmonary gas exchange model is to study the effect produced by an inhomogeneous distribution of the ventilation-perfusion (V A/Q) and diffusion-perfusion (D/Q) ratios on the oxygen transfer. We calculate partial pressures of oxygen and carbon dioxide in venous blood, in capillary blood and alveolar gas of each element as the unique solution of a non-linear system, the parameters of which are the local values of ventilation, perfusion and diffusion. We show that an inhomogeneous distribution of any ratio leads to a decrease of the mixed arterial concentration of oxygen and that the greater the inhomogeneity, the greater the decrease. We show by numerical stimulation that if two inhomogeneities (V A/Q) and (D/Q) are associated, the oxygen arterial concentration decrease is rather less important if the diffusion-ventilation ratio has a distribution almost homogeneous, i.e. if the V A/Q and D/Q inhomogeneities are almost identical.


Asunto(s)
Modelos Biológicos , Capacidad de Difusión Pulmonar , Relación Ventilacion-Perfusión , Dióxido de Carbono/sangre , Humanos , Matemática , Oxígeno/sangre
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