Avaliação do alinhamento postural e do desempenho em atividades funcionais de crianças hemofílicas em idade inferior a sete anos, com e sem sinovite crônica: correlação com a incidência de hemartroses / Evaluation of postural alignment and performance in functional activities among hemophilic children under 7 years old with and without chronic synovitis: correlation with hemarthrosis incidence

INTRODUÇÃO: A sinovite na hemofilia pode induzir às alterações nos receptores sensitivos e proprioceptivos articulares. Tal efeito favorece a redução de estabilidade e um desalinhamento corporal, podendo comprometer a funcionalidade das crianças acometidas. OBJETIVO: Avaliar o alinhamento postural dos membros inferiores e o desempenho funcional de crianças hemofílicas, relacionando-os com a incidência de hemartroses. MÉTODO: Foi avaliado um grupo experimental (GE) de 28 crianças hemofílicas e um grupo controle (GC) de 20 crianças sem hemofilia. O GE foi dividido de acordo com o grau de comprometimento articular: 16 crianças no grupo sem sinovite crônica (GSS) e 12 no grupo com sinovite crônica (GCS). Cada grupo foi subdividido por faixa etária: 3-4 anos, 5-6 anos, 7 anos. A avaliação consistiu da análise do alinhamento dos ângulos do joelho e do tornozelo através do programa Geometer Sketchpad. O desempenho das atividades funcionais foi avaliado através de testes modificados a partir do Exame Neurológico Evolutivo de Lefévre. RESULTADOS: Foi constatado que a média dos sangramentos dos hemofílicos aumenta com a idade (p< 0,001) e parece ser relacionada com o grau de comprometimento articular (GCS>GSS), (p< 0,059); o ângulo do joelho do GCS tende a um menor valor (semiflexão) quando comparado aos outros grupos; e há diferença significativa no percentual de desempenho nos testes entre grupos na faixa etária de 7 anos (GSS>GC e GSS>GCS), (p< 0,087). DISCUSSÃO E CONCLUSÃO: Crianças hemofílicas de 7 anos apresentaram menor desempenho funcional quando comparadas aos outros grupos. Este resultado ressalta a importância da fisioterapia precoce associada à terapêutica médica para evitar comprometimentos articulares severos.

Determination of serum aluminum, platelet aggregation and lipid peroxidation in hemodialyzed patients

Aluminum (Al3+) overload is frequently associated with lipid peroxidation and neurological disorders. Aluminum accumulation is also reported to be related to renal impairment, anemia and other clinical complications in hemodialysis patients. The aim of the present study was to determine the degree of lipid peroxidation, platelet aggregation and serum aluminum in patients receiving regular hemodialytic treatment. The level of plasma lipid peroxidation was evaluated on the basis of thiobarbituric acid reactive substances (TBARS). Mean platelet peroxidation in patients undergoing hemodialysis was significantly higher than in normal controls (2.7 ± 0.03 vs 1.8 ± 0.06 nmol/l, P<0.05). Platelet aggregation and serum aluminum levels were determined by a turbidimetric method and atomic absorption spectrophotometry, respectively. Serum aluminum was significantly higher in patients than in normal controls (44.5 ± 29 vs 10.8 ± 2.5 æg/l, P<0.05). Human blood platelets were stimulated with collagen (2.2 æg/ml), adenosine diphosphate (6 æM) and epinephrine (6 æM) and showed reduced function with the three agonists utilized. No correlation between aluminum levels and platelet aggregation or between aluminum and peroxidation was observed in hemodialyzed patients

Aluminum induces lipid peroxidation and aggregation of human blood platelets

Aluminum (Al3+) intoxication is thought to play a major role in the development of Alzheimer's disease and in certain pathologic manifestations arising from long-term hemodialysis. Although the metal does not present redox capacity, it can stimulate tissue lipid peroxidation in animal models. Furthermore, in vitro studies have revealed that the fluoroaluminate complex induces diacyglycerol formation, 43-kDa protein phosphorylation and aggregation. Based on these observations, we postulated that Al3+-induced blood platelet aggregation was mediated by lipid peroxidation. Using chemiluminescence (CL) of luminol as an index of total lipid peroxidation capacity, we established a correlation between lipid peroxidation capacity and platelet aggregation. Al3+ (20-100 muM) stimulated CL production by human blood platelets as well as their aggregation. Incubation of the platelets with the antioxidants nor-dihydroguaiaretic acid (NDGA) (100 muM) and n-propyl gallate (NPG) (100 muM), inhibitors of the lipoxygenase pathway, completely prevented CL and platelet aggregation. Acetyl salicylic acid (ASA) (100 muM), an inhibitor of the cyclooxygenase pathway, was a weaker inhibitor of both events. These findings suggest that Al3+ stimulates lipid peroxidation and the lipoxygenase pathway in human blood platelets thereby causing their aggregation.

An aqueous extract of guaraná (Paullinia cupana) decreases platelet thromboxane synthesis

The effects of an aqueous extract of guaraná (Paullinia cupana) on rabbit platelet aggregation and thromboxane synthesis were examined. The guaraná extract (100 mg/ml) and fractions separated by TLC (origin and xanthines) decreased platelet aggregation (37.27 and 31% of control values, respectively) and platelet thromboxane formation from [14C]-arachidonic acid (78, 70 and 50% of control values respectively). The decreased thromboxane synthesis could be responsible, at least in part, for the antiaggregatory action of guaraná