RESUMEN
Purpose The purpose of this study was to evaluate the safety of antithrombotic treatments prescribed during pregnancy in patients with antiphospholipid syndrome (APS). Methods This international, multicenter study included two cohorts of patients: a retrospective French cohort and a prospective US cohort (PROMISSE study). Inclusion criteria were (1) APS (Sydney criteria), (2) live pregnancy at 12 weeks of gestation (WG) with (3) follow-up data until six weeks post-partum. According to APS standard of care, patients were treated with aspirin and/or low-molecular weight heparin (LMWH) at prophylactic (pure obstetric APS) or therapeutic doses (history of thrombosis). Major bleeding was defined as abnormal blood loss during the pregnancy and/or post-partum period requiring intervention for hemostasis or transfusion, or during the peripartum period greater than 500 mL and/or requiring surgery or transfusion. Other bleeding events were classified as minor. Results Two hundred and sixty-four pregnancies (87 prospectively collected) in 204 patients were included (46% with history of thrombosis, 23% with associated systemic lupus). During pregnancy, treatment included LMWH ( n = 253; 96%) or low-dose aspirin ( n = 223; 84%), and 215 (81%) patients received both therapies. The live birth rate was 89% and 82% in the retrospective and prospective cohorts, respectively. Adverse pregnancy outcomes occurred in 28% of the retrospective cohort and in 40% of the prospective cohort. No maternal death was observed in either cohort. A combined total of 45 hemorrhagic events (25%) occurred in the retrospective cohort, but major bleeding was reported in only six pregnancies (3%). Neither heparin nor aspirin alone nor combined therapy increased the risk of hemorrhage. We also did not observe an increased rate of bleeding in the case of a short interval between last LMWH (less than 24 hours) or aspirin (less than five days) doses and delivery. Only emergency Caesarean section was significantly associated with an increased risk of bleeding (odds ratio (OR) 5.03 (1.41-17.96); p=.016). In the prospective cohort, only one minor bleeding event was reported (vaginal bleeding). Conclusion Our findings support the safety of antithrombotic therapy with aspirin and/or LMWH during pregnancy in high-risk women with APS, and highlight the need for better treatments to improve pregnancy outcomes in APS. PROMISSE Study ClinicalTrials.gov identifier: NCT00198068.
Asunto(s)
Anticoagulantes/efectos adversos , Síndrome Antifosfolípido/tratamiento farmacológico , Aspirina/efectos adversos , Fibrinolíticos/efectos adversos , Heparina de Bajo-Peso-Molecular/efectos adversos , Inhibidores de Agregación Plaquetaria/efectos adversos , Hemorragia Posparto/inducido químicamente , Adulto , Síndrome Antifosfolípido/sangre , Síndrome Antifosfolípido/diagnóstico , Pérdida de Sangre Quirúrgica/prevención & control , Transfusión Sanguínea , Cesárea/efectos adversos , Quimioterapia Combinada , Femenino , Francia , Humanos , Hemorragia Posoperatoria/inducido químicamente , Hemorragia Posoperatoria/terapia , Hemorragia Posparto/diagnóstico , Hemorragia Posparto/terapia , Embarazo , Estudios Prospectivos , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento , Estados UnidosRESUMEN
A causal link has long been described between estrogen and systemic lupus erythematosus activity. Contraceptive and pregnancy management is now common for lupus patients, but pregnancy continues to be associated with higher maternal and fetal mortality/morbidity in systemic lupus erythematosus patients than among the general population. Potential complications include lupus flares, obstetric complications (fetal loss, in utero growth retardation, premature birth) and neonatal lupus syndrome. Association with antiphospholipid antibodies or antiphospholipid syndrome increases the risk of obstetric complications. Anti-SSA and/or anti-SSB antibodies put fetuses at risk for neonatal lupus. Improving the outcome of such pregnancies depends upon optimal systematic planning of pregnancy at a preconception counseling visit coupled with a multidisciplinary approach. Absence of lupus activity, use of appropriate medication during pregnancy based on the patient's medical history and risk factors, and regular monitoring constitute the best tools for achieving a favorable outcome in such high-risk pregnancies. The aim of this review is to provide an update on the management of contraception and pregnancy in systemic lupus erythematosus, cutaneous lupus and/or antiphospholipid syndrome in order to reduce the risk of complications and to ensure the best maternal and fetal prognosis.
Asunto(s)
Lupus Eritematoso Cutáneo/complicaciones , Lupus Eritematoso Sistémico/complicaciones , Complicaciones del Embarazo , Embarazo de Alto Riesgo , Anticuerpos Antifosfolípidos/sangre , Anticoagulantes/uso terapéutico , Síndrome Antifosfolípido/complicaciones , Anticoncepción , Ecocardiografía , Femenino , Muerte Fetal , Retardo del Crecimiento Fetal/etiología , Humanos , Recién Nacido , Lupus Eritematoso Cutáneo/terapia , Lupus Eritematoso Sistémico/congénito , Lupus Eritematoso Sistémico/etiología , Lupus Eritematoso Sistémico/prevención & control , Lupus Eritematoso Sistémico/terapia , Periodo Posparto , Atención Preconceptiva , Embarazo , Nacimiento Prematuro/etiología , Pronóstico , Ultrasonografía PrenatalRESUMEN
Myotonic dystrophy (DM) is caused by the expansion of a CTG trinucleotide repeat. The mutation is in complete linkage disequilibrium with a nearly two-allele insertion/deletion polymorphism, suggesting a single origin for the mutation or predisposing mutation. To trace this-ancestral event, we have studied the association of CTG repeat alleles in a normal population to alleles of the insertion/deletion polymorphism and of a (CA)n repeat marker 90 kilobases from the DM mutation. The results strongly suggest that the initial predisposing event(s) consisted of a transition from a (CTG)5 allele to an allele with 19 to 30 repeats. The heterogeneous class of (CTG)19-30 alleles which has an overall frequency of about 10%, may constitute a reservoir for recurrent DM mutations.
Asunto(s)
Cromosomas Humanos Par 19 , Mutación , Distrofia Miotónica/genética , Secuencias Repetitivas de Ácidos Nucleicos , Alelos , Secuencia de Bases , Evolución Biológica , Síndrome del Cromosoma X Frágil/genética , Marcadores Genéticos , Haplotipos/genética , Humanos , Incidencia , Desequilibrio de Ligamiento , Modelos Genéticos , Datos de Secuencia Molecular , Atrofia Muscular Espinal/genética , Distrofia Miotónica/epidemiología , Polimorfismo Genético , Eliminación de Secuencia , Población Blanca/genéticaRESUMEN
Huntington's disease (HD) results from the expansion of a polyglutamine encoding CAG repeat in a gene of unknown function. The wide expression of this transcript does not correlate with the pattern of neuropathology in HD. To study the HD gene product (huntingtin), we have developed monoclonal antibodies raised against four different regions of the protein. On western blots, these monoclonals detect the approximately 350 kD huntingtin protein in various human cell lines and in neural and non-neural rodent tissues. In cell lines from HD patients, a doublet protein is detected corresponding to the mutated and normal huntingtin. Immunohistochemical studies in the human brain using two of these antibodies detects the huntingtin in perikarya of some neurons, neuropiles, varicosities and as punctate staining likely to be nerve endings.
Asunto(s)
Enfermedad de Huntington/genética , Mutación , Proteínas del Tejido Nervioso/análisis , Proteínas Nucleares/análisis , Secuencia de Aminoácidos , Animales , Anticuerpos Monoclonales/inmunología , Western Blotting , Encéfalo/metabolismo , Línea Celular , Chlorocebus aethiops , Clonación Molecular , ADN Complementario , Femenino , Técnica del Anticuerpo Fluorescente , Regulación de la Expresión Génica , Humanos , Proteína Huntingtina , Enfermedad de Huntington/metabolismo , Linfocitos/metabolismo , Masculino , Ratones , Datos de Secuencia Molecular , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/inmunología , Proteínas Nucleares/genética , Proteínas Nucleares/inmunología , Ratas , Proteínas Recombinantes de Fusión/inmunología , Secuencias Repetitivas de Ácidos Nucleicos , Distribución Tisular , TransfecciónRESUMEN
Two forms of the neurodegenerative disorder spinocerebellar ataxia are known to be caused by the expansion of a CAG (polyglutamine) trinucleotide repeat. By screening cDNA expression libraries, using an antibody specific for polyglutamine repeats, we identified six novel genes containing CAG stretches. One of them is mutated in patients with spinocerebellar ataxia linked to chromosome 12q (SCA2). This gene shows ubiquitous expression and encodes a protein of unknown function. Normal SCA2 alleles (17 to 29 CAG repeats) contain one to three CAAs in the repeat. Mutated alleles (37 to 50 repeats) appear particularly unstable, upon both paternal and maternal transmissions. The sequence of three of them revealed pure CAG stretches. The steep inverse correlation between age of onset and CAG number suggests a higher sensitivity to polyglutamine length than in the other polyglutamine expansion diseases.
Asunto(s)
Proteínas/genética , Secuencias Repetitivas de Ácidos Nucleicos , Degeneraciones Espinocerebelosas/genética , Adolescente , Adulto , Edad de Inicio , Alelos , Secuencia de Aminoácidos , Anticuerpos Monoclonales , Ataxinas , Secuencia de Bases , Niño , Clonación Molecular , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/inmunología , Femenino , Regulación de la Expresión Génica , Humanos , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Proteínas del Tejido Nervioso , Proteína de Unión a TATA-Box , Factores de Transcripción/genética , Factores de Transcripción/inmunología , Repeticiones de TrinucleótidosRESUMEN
The gene for spinocerebellar ataxia 7 (SCA7) has been mapped to chromosome 3p12-13. By positional cloning, we have identified a new gene of unknown function containing a CAG repeat that is expanded in SCA7 patients. On mutated alleles, CAG repeat size is highly variable, ranging from 38 to 130 repeats, whereas on normal alleles it ranges from 7 to 17 repeats. Gonadal instability in SCA7 is greater than that observed in any of the seven known neuro-degenerative diseases caused by translated CAG repeat expansions, and is markedly associated with paternal transmissions. SCA7 is the first such disorder in which the degenerative process also affects the retina.
Asunto(s)
Cromosomas Humanos Par 3 , Proteínas del Tejido Nervioso/genética , Degeneraciones Espinocerebelosas/genética , Repeticiones de Trinucleótidos , Adulto , Edad de Inicio , Anciano , Alelos , Secuencia de Aminoácidos , Ataxina-7 , Mapeo Cromosómico , Cromosomas Artificiales de Levadura , Clonación Molecular , Femenino , Marcadores Genéticos , Variación Genética , Impresión Genómica , Humanos , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Proteínas del Tejido Nervioso/biosíntesis , Proteínas del Tejido Nervioso/química , Retina/patología , Degeneración Retiniana/genética , Degeneración Retiniana/fisiopatología , Degeneraciones Espinocerebelosas/mortalidad , Degeneraciones Espinocerebelosas/fisiopatologíaRESUMEN
Nosocomial infections in neonatal intensive care units are a preoccupying issue. Bacillus sp. can be pathogenic in immuno-compromised hosts, including premature infants. Central catheters and mechanical ventilation are potential sources of infection. We report for the first time a case of Bacillus licheniformis bacteremia in a premature infant. Recovery necessitated treatment with vancomycin and cefotaxime in combination with removal of the central catheter.
Asunto(s)
Bacillus/aislamiento & purificación , Infecciones por Bacterias Grampositivas/diagnóstico , Recien Nacido con Peso al Nacer Extremadamente Bajo , Enfermedades del Prematuro/diagnóstico , Sepsis/diagnóstico , Antibacterianos/uso terapéutico , Bacillus/genética , Proteína C-Reactiva/análisis , Cateterismo Venoso Central , Infecciones por Bacterias Grampositivas/tratamiento farmacológico , Infecciones por Bacterias Grampositivas/microbiología , Humanos , Recién Nacido , Recien Nacido Prematuro , Enfermedades del Prematuro/tratamiento farmacológico , Enfermedades del Prematuro/microbiología , Masculino , Pruebas de Sensibilidad Microbiana , Respiración Artificial , Sepsis/tratamiento farmacológico , Sepsis/microbiología , Desconexión del VentiladorRESUMEN
Liver dysfunction during pregnancy can be related or not to pregnancy itself. The purpose of this review is to summarize the possible causes of liver dysfunction during pregnancy and their management. Liver dysfunction during pregnancy can be chronic or acute, independent or specific to pregnancy. Management of liver disease can be different during pregnancy. The knowledge of liver dysfunction during pregnancy is of help for a better management of the mother in order to avoid maternal and fetal mortality and morbidity.
Asunto(s)
Hepatopatías/diagnóstico , Hepatopatías/terapia , Complicaciones del Embarazo/diagnóstico , Complicaciones del Embarazo/terapia , Femenino , Humanos , Pruebas de Función Hepática , EmbarazoRESUMEN
PURPOSE: To develop French recommendations about the management of vaccinations, the screening of cervical cancer and the prevention of pneumocystis pneumonia in systemic lupus erythematosus (SLE). METHODS: Thirty-seven experts qualified in internal medicine, rheumatology, dermatology, nephrology and pediatrics have selected recommendations from a list of proposition based on available data from the literature. For each recommendation, the level of evidence and the level of agreement among the experts were specified. RESULTS: Inactivated vaccines do not cause significant harm in SLE patients. Experts recommend that lupus patient should receive vaccinations accordingly to the recommendations and the schedules for the general public. Pneumococcal vaccination is recommended for all SLE patients. Influenza vaccination is recommended for immunosuppressed SLE patients. Live attenuated vaccines should be avoided in immunosuppressed patients. Yet, recent works suggest that they can be considered in mildly immunosuppressed patients. Experts have recommended a cervical cytology every year for immunosuppressed patients. No consensus was obtained for the prevention of pneumocystis pneumonia. CONCLUSION: These recommendations can be expected to improve clinical practice uniformity and, in the longer term, to optimize the management of SLE patients.
Asunto(s)
Testimonio de Experto , Control de Infecciones/normas , Lupus Eritematoso Sistémico/complicaciones , Lupus Eritematoso Sistémico/terapia , Guías de Práctica Clínica como Asunto , Adolescente , Adulto , Francia , Humanos , Huésped Inmunocomprometido , Control de Infecciones/métodos , Infecciones/diagnóstico , Lupus Eritematoso Sistémico/diagnóstico , Lupus Eritematoso Sistémico/inmunología , Literatura de Revisión como Asunto , Vacunación/normas , Adulto JovenRESUMEN
Pre-pregnancy counseling is one of the keys of success of pregnancy in women with autoimmune or systemic diseases, especially lupus or antiphospholipid syndrome. This type of consultation should be offered to all women with systemic diseases, giving the possibility to allow a pregnancy or to explain why this project should be delayed, to anticipate some problems, to give comprehensive informations to the couple, to organize the multidisciplinary monitoring, to adapt treatments, and finally, to verify the validity of some vaccinations. The generalization of pre-pregnancy counseling should allow to minimize risks for both mother and fetus, then, to improve the prognosis of these high risk pregnancies.
Asunto(s)
Enfermedades Autoinmunes/terapia , Consejo , Complicaciones del Embarazo/terapia , Femenino , Humanos , Embarazo , Factores de RiesgoRESUMEN
Liver disease can be observed in pregnant women whether or not related to pregnancy. Liver disorders can be revealed by pruritus, vomiting, jaundice or abnormal liver blood tests during pregnancy. These liver manifestations can lead to the diagnosis of liver disease specifically associated to pregnancy as intrahepatic pregnancy, intrahepatic cholestasis of pregnancy, Hyperemesis gravidarum, acute fatty liver of pregnancy and preeclampsia-induced liver injury. Pregnancy may also be a risk factor for other liver diseases coincident with pregnancy as viral hepatitis, thrombosis, drug toxicity or gallstone. Finally, pre-existing liver disease must be taken into account given the risk of fÅto-maternal transmission risk as well as the risk of decompensation of underlying cirrhosis secondary to the hemodynamic changes caused by pregnancy. The aim of this revue is to perform an update on the various situations that can be observed, the principles of management of these liver diseases, in order to reduce the risk of complications and to ensure the best maternal and fetal prognosis.
Asunto(s)
Hepatopatías/diagnóstico , Hígado/fisiopatología , Complicaciones del Embarazo/diagnóstico , Femenino , Feto , Humanos , Hepatopatías/complicaciones , Hepatopatías/terapia , Embarazo , Complicaciones del Embarazo/terapia , Factores de RiesgoRESUMEN
Pregnancy in systemic lupus erythematosus patients is a common situation that remains associated with higher maternal and fetal mortality/morbidity than in the general population. Complications include lupus flares, obstetrical complications (fetal loss, in utero growth retardation, prematurity) and neonatal lupus syndrome. The association with antiphospholipid antibodies or antiphospholipid syndrome increases the risk of obstetrical complications. Improving the care of these pregnancies depends upon a systematic pregnancy planning, ideally during a preconception counseling visit and a multidisciplinary approach (internist/rheumatologist, obstetrician and anesthetist). The absence of lupus activity, the use of appropriate medications during pregnancy adjusted to the patient's medical history and risk factors, and a regular monitoring are the best tools for a favorable outcome for these high-risk pregnancies. The aim of this review article is to perform an update on the medical care of pregnancy in systemic lupus erythematosus or antiphospholipid syndrome to reduce the risk of complications and to ensure the best maternal and fetal prognosis.
Asunto(s)
Síndrome Antifosfolípido/complicaciones , Lupus Eritematoso Sistémico/complicaciones , Complicaciones del Embarazo/terapia , Anticuerpos Antinucleares , Síndrome Antifosfolípido/terapia , Femenino , Humanos , Lupus Eritematoso Sistémico/terapia , EmbarazoRESUMEN
Fertility is not impaired in systemic lupus erythematosus or antiphospholipid syndrome, but, similarly to the general population, these patients may undergo in vitro fertilization. This type of treatment increases the risk of lupus flare, thrombosis, and ovarian hyperstimulation syndrome. This review will focus on in vitro fertilization in systemic lupus erythematosus or antiphospholipid syndrome. Literature data are relatively scant with only 3 reported studies. The first one included 17 patients and 63 cycles of induction ovulation/in vitro fertilization leading to 25 % of lupus flare, no thrombosis, and 3 % of ovarian hyperstimulation syndrome. The second study included 10 patients and 40 cycles of in vitro fertilization showing 31 % of lupus flare, no thrombosis and no ovarian hyperstimulation syndrome. The last one included 34 patients and 83 procedures of in vitro fertilization leading to 8 % of flares, 5 % of thrombosis and no ovarian hyperstimulation syndrome. Interestingly, in this last study, half of the complications were explained by poor adherence to treatment. These data are reassuring but it is important to remember that in vitro fertilization should be scheduled and carefully supervised in the same way as the high-risk pregnancies occurring in these patients.
Asunto(s)
Síndrome Antifosfolípido/complicaciones , Fertilización In Vitro/efectos adversos , Lupus Eritematoso Sistémico/complicaciones , Síndrome Antifosfolípido/terapia , Femenino , Fertilización In Vitro/métodos , Humanos , Lupus Eritematoso Sistémico/terapia , EmbarazoRESUMEN
Neonatal lupus syndrome is associated with transplacental passage of maternal anti-SSA/Ro and anti-SSB/La antibodies. Children display cutaneous, hematological, liver or cardiac features. Cardiac manifestations include congenital heart block (CHB); endocardial fibroelastosis and dilated cardiomyopathy. The prevalence of CHB in newborns of anti-Ro/SSA positive women with known connective tissue disease is between 1 and 2% and the risk of recurrence is around 19%. Skin and systemic lesions are transient, whereas CHB is definitive and associated with significant morbidity and a mortality of 18%. A pacemaker must be implanted in 2/3 of cases. Myocarditis may be associated or appear secondly. Mothers of children with CHB are usually asymptomatic or display Sjogren's syndrome or undifferentiated connective tissue disease. In anti-Ro/SSA positive pregnant women, fetal echocardiography should be performed at least every 2 weeks from the 16th to 24th week gestation. An electrocardiogram should be performed for all newborn babies. The benefit of fluorinated corticosteroid therapy for CHB detected in utero remains unclear. Maternal use of hydroxychloroquine may be associated with a decreased recurrent CHB risk in a subsequent offspring. A prospective study is actually ongoing to confirm these findings.
Asunto(s)
Anticuerpos Antinucleares/sangre , Bloqueo Cardíaco/congénito , Lupus Eritematoso Sistémico/congénito , Complicaciones del Embarazo/inmunología , Femenino , Bloqueo Cardíaco/etiología , Bloqueo Cardíaco/terapia , Humanos , Recién Nacido , Lupus Eritematoso Sistémico/complicaciones , Lupus Eritematoso Sistémico/diagnóstico , Lupus Eritematoso Sistémico/inmunología , Embarazo , Complicaciones del Embarazo/diagnósticoRESUMEN
PURPOSE: To develop French recommendations about screening and management of cardiovascular risk factors in systemic lupus erythematosus (SLE). METHODS: Thirty-nine experts qualified in internal medicine, rheumatology and nephrology have selected recommendations from a list developed based on evidence from the literature. For each recommendation, the level of evidence and the level of agreement among the experts were specified. RESULTS: Experts recommended an annual screening of cardiovascular risk factors in SLE. Statins should be prescribed for primary prevention in SLE patients based on the level of LDL-cholesterol and the number of cardiovascular risk factors, considering SLE as an additional risk factor. For secondary prevention, experts have agreed on an LDL-cholesterol target of <0.7 g/L. Hypertension should be managed according to the 2013 European guidelines, using renin-angiotensin system blockers as first line agents in case of renal involvement. Aspirin can be prescribed in patients with high cardiovascular risk or with antiphospholipid antibodies. CONCLUSION: These recommendations about the screening and management of cardiovascular risk factors in SLE can be expected to improve clinical practice uniformity and, in the longer term, to optimize the management of SLE patients.
Asunto(s)
Enfermedades Cardiovasculares/etiología , Lupus Eritematoso Sistémico/complicaciones , Tamizaje Masivo/métodos , Enfermedades Cardiovasculares/diagnóstico , Enfermedades Cardiovasculares/tratamiento farmacológico , Medicina Basada en la Evidencia , Testimonio de Experto , Guías como Asunto , Humanos , Factores de Riesgo , Prevención SecundariaRESUMEN
We report on a patient with moderate mental retardation and a typical fragile X phenotype, with no family history and no fragile X site on cytogenetic analysis. The patient was found to have a deletion encompassing part of the FMR1 gene and a 70-100 kb region upstream of the FMR1 promotor region. This deletion is smaller than those previously reported and confirms that FMR1 is the major and probably the only gene implicated in the phenotype of the fragile X syndrome.
Asunto(s)
Síndrome del Cromosoma X Frágil/genética , Eliminación de Gen , Adulto , Southern Blotting , Humanos , Masculino , Fenotipo , Reacción en Cadena de la PolimerasaRESUMEN
A prospective study of infective endocarditis (IE) was conducted between 1994 and 2000 in Marseilles, France, and included 170 definite cases diagnosed with the use of modified Duke criteria. Classification of IE based on the aetiological agent was related to epidemiological characteristics, including age, gender and the nature of the injured valve. Enterococci and Streptococcus bovis were identified more frequently in older subjects (p 0.02), and S. bovis was also associated with mitral valve infection (p 0.03). Streptococcus spp. were found to be associated with native valves (p < 10(-3)), whereas coagulase-negative staphylococci and Coxiella burnetii were associated with intracardiac prosthetic material (p < 0.05). S. bovis and Staphylococcus aureus were the predominant species associated with presumably healthy valves (p < 0.05), whereas oral streptococci caused IE exclusively in patients with previous valve damage. The basic host status of IE patients has been linked to specific microorganisms, and this may be of value when empirical treatment is needed in patients who have received previous antibiotic therapy and whose blood cultures are negative.
Asunto(s)
Endocarditis Bacteriana/microbiología , Enfermedades de las Válvulas Cardíacas/complicaciones , Infecciones Relacionadas con Prótesis/complicaciones , Adolescente , Adulto , Distribución por Edad , Anciano , Anciano de 80 o más Años , Válvula Aórtica/microbiología , Coxiella/aislamiento & purificación , Endocarditis Bacteriana/epidemiología , Femenino , Cocos Grampositivos/clasificación , Cocos Grampositivos/aislamiento & purificación , Enfermedades de las Válvulas Cardíacas/microbiología , Prótesis Valvulares Cardíacas/microbiología , Humanos , Masculino , Persona de Mediana Edad , Válvula Mitral/microbiología , Prevalencia , Estudios Prospectivos , Infecciones Relacionadas con Prótesis/microbiología , Distribución por Sexo , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/microbiología , Infecciones Estreptocócicas/epidemiología , Infecciones Estreptocócicas/microbiologíaRESUMEN
Evaluation of loads acting on the spine requires the knowledge of the muscular forces acting on it, but muscles redundancy necessitates developing a muscle forces attribution strategy. Optimisation, EMG, or hybrid models allow evaluating muscle force patterns, yielding a unique muscular arrangement or/and requiring EMG data collection. This paper presents a regulation model of the trunk muscles based on a proprioception hypothesis, which searches to avoid the spinal joint overloading. The model is also compared to other existing models for evaluation. Compared to an optimisation model, the proposed alternative muscle pattern yielded a significant spine postero-anterior shear decrease. Compared to a model based on combination of optimisation criteria, present model better fits muscle activation observed using EMG (38% improvement). Such results suggest that the proposed model, based on regulation of all spinal components, may be more relevant from a physiologic point of view.
Asunto(s)
Vértebras Lumbares/fisiología , Modelos Biológicos , Contracción Muscular/fisiología , Músculo Esquelético/fisiología , Equilibrio Postural/fisiología , Postura/fisiología , Propiocepción/fisiología , Abdomen/fisiología , Dorso/fisiología , Simulación por Computador , Diagnóstico por Computador/métodos , Electromiografía/métodos , Retroalimentación/fisiología , Humanos , Vértebras Lumbares/inervación , Músculo Esquelético/inervación , Estrés MecánicoRESUMEN
The authors followed, during 4 years consecutively, from 1987 to 1990, by immunofluorescence, the frequency of B. burgdorferi in an amount of 677 nymphs of I. ricinus tick, collected fasting by flagging in 2 forests in Brittany (France). Percentages obtained in each of these forests do not reveal significative differencies statistically and seem to show a relative stability, from one year to the following, during the considered period, of the infestation levels in ticks.
Asunto(s)
Vectores Arácnidos/microbiología , Grupo Borrelia Burgdorferi/aislamiento & purificación , Garrapatas/microbiología , Árboles , Animales , Recolección de Datos , Entomología , Francia/epidemiología , Estudios Longitudinales , Enfermedad de Lyme/epidemiología , Enfermedad de Lyme/transmisiónRESUMEN
The objectives of the study are to describe and use a muscular model to compare spinal loads and muscles recruitments between an unbalanced subject (patient) and a normal volunteer. Data collection was performed and imputed into the muscular model: from sagittal X-rays, together with plantar foot pressure measurements, external loads for the L3/L4 level were calculated. Using MRI of the thoraco-lumbar region and muscular testing, a personalized muscular model was constructed. The main results are as follow: external loads for the unbalanced subject were higher because of the postural default, especially for flexion moment. Running the model, simulations showed a higher erector spinae group activation for the patient. This induced a significant difference in joint compression. Setting the maximum admissible stress of the extensor muscles of the patient to an equivalent level as the one found for the volunteer to maintain the posture, a second simulation was performed. Joint compression was reduced, but postero-anterior shear and flexion moment increased drastically. The model suggests that either the muscular system needed a stronger activation, yielding a higher joint compression and probably a muscle fatigue in such an activation level, or the spinal loads increased to a higher and probably dangerous level.