RESUMO
INTRODUCTION: About half of patients with acute liver failure (ALF) show clinical signs of cerebral edema and intracranial hypertension. Neuroimaging diagnostics and electroencephalography have poor correlation with intracranial pressure measurement. OBJECTIVE: The objective of this study was to characterize the cerebral hemodynamics patterns with transcranial Doppler (TCD) sonography in patients with ALF. METHOD: We studied 21 patients diagnosed with ALF, admitted to the intensive care unit (ICU) at the Centro de Investigaciones Médico Quirúrgicas of Cuba. All of these patients had a TCD performed on arrival at ICU, evaluating the following: systolic (SV), diastolic (DV), and medium (MV) flows velocities and pulsatility index (PI) in right middle cerebral artery (RMCA) via temporal windows. RESULTS: The sonographic patterns of cerebral hemodynamics were as follows: low-flow, 12 patients (57.1%); high resistance, 5 patients (23.8%); and hyperemic, 4 patients (19%). Patients who died while waiting had lower MV RMCA (56.1 vs 58.1 cm/s) and higher PI (1.71 vs 1.41) than patients who could undergo transplantation (P = .800 and P = .787, respectively). CONCLUSIONS: In patients diagnosed with ALF admitted to the ICU the predominating cerebral hemodynamic pattern was low-flow with resistance increase. The TCD was shown to be a useful tool in the initial evaluation for prognosis and treatment.
Assuntos
Circulação Cerebrovascular , Hemodinâmica , Falência Hepática Aguda/fisiopatologia , Artéria Cerebral Média/fisiopatologia , Ultrassonografia Doppler Transcraniana , Adolescente , Adulto , Velocidade do Fluxo Sanguíneo , Cuba , Feminino , Humanos , Hiperemia/etiologia , Hiperemia/fisiopatologia , Unidades de Terapia Intensiva , Pressão Intracraniana , Falência Hepática Aguda/etiologia , Masculino , Pessoa de Meia-Idade , Artéria Cerebral Média/diagnóstico por imagem , Adulto JovemRESUMO
Amaranthus leucocarpus lectin is a homodimeric glycoprotein of 35 kDa per sub-unit, which interacts specifically with N-acetyl-galactosamine. In this work, we compared different glycoproteins that contain Galbeta1-3 GalNAcalpha1-3 Ser/Thr or GalNAcalpha1-3 Ser/Thr in their structure as ligands to purify the A. leucocarpus lectin. From the glycoproteins tested, fetuin was the most potent inhibitor of the hemagglutinating activity and the better ligand for lectin purification; however, the use of desialylated stroma from erythrocytes represented the cheapest method to purify this lectin. O-linked glycans released from the glycoproteins used as affinity matrix and those from different erythrocytes were less inhibitory than parental glycoproteins. The NH2-terminal of the lectin is blocked; moreover, this is the only example of a lectin isolated from this genus to be a glycoprotein. Analysis of the glycoprotein sequences with inhibitory activity for the lectin, showed a different pattern in the O-glycosylation, which confirms that A. leucocarpus lectin recognizes conformation and, probably, distances among O-linked glycans moieties.