Vigabatrin as a first-choice drug in the treatment of West syndrome.

This is a prospective study designed to evaluate the efficacy and safety of vigabatrin as first-choice monotherapy in infants with West syndrome. One hundred sixteen patients with newly diagnosed West syndrome were studied in Argentina, from June 1994 to April 1998. The follow-up ranged from 17 to 40 months (mean, 23 months). Vigabatrin was administered upon diagnosis, starting with a 50-mg/kg/day dose and increasing 50 mg/kg every 48 hours to reach a maximum dose of 200 mg/kg/day. Twenty-nine percent of cases were considered to be cryptogenic or idiopathic West syndrome, while 70.7% were symptomatic. Response to vigabatrin treatment was measured according to five categories: (1) seizures free: 61.8% of cases for cryptogenic and 29.3% for symptomatic West syndrome, (2) more than 75% reduction in the number of infantile spasms: 14.7% for cryptogenic and 26.8% for symptomatic West syndrome, (3) from 50% to 74% reduction in the number of infantile spasms: 11.8% for cryptogenic and 24.4% for symptomatic West syndrome, (4) poor or null response: 11.8% for cryptogenic and 18.3% for symptomatic West syndrome, and (5) increase in the number of infantile spasms: one symptomatic case (1.2%). All seizure-free cryptogenic cases showed normal neuropsychic development. The most effective dose of vigabatrin was 150 mg/kg of body weight per day. The most frequent adverse events were somnolence in 19 cases and irritability in 15 cases, but none required treatment interruption.

Parameters affecting the adsorption of ligands to polyvinyl chloride plates in enzyme immunoassays.

In the present work, we studied the efficacy of three blocking agents (HSA, BSA and OVA) in the inhibition of non-specific binding to PVC plates. According to the inhibition data, 1% OVA was the most effective blocking agent. On the other hand, the presence of detergents in all of the blocking solutions drastically decreased the percent inhibition of the non-specific binding. Furthermore, the effect of ligand concentration on adsorption and the kinetics of ligand adsorption to PVC plates were also investigated. Ligand adsorption is a linear function of input up to a limit (around 8.70 ng/mm2) where saturation is reached. The rate of adsorption of pure human IgG to PVC plates was proportionally increased with the temperature, as shown by proportional rate constants almost 2 times faster at 37 degrees C than at 4 degrees C. These results have practical implications for investigators using PVC for immunoassays and should be taken into consideration when designing such assays.

Serum pregnancy-associated alpha 2-glycoprotein levels in the evolution of hepatitis B virus infection.

Serum pregnancy-associated alpha 2-glycoprotein (alpha 2-PAG) levels were evaluated in a follow-up study of patients with hepatitis B virus (HBV) infection and compared with biochemical and virological parameters. In a study of 25 patients with acute hepatitis, an association was found between high alpha 2-PAG values, ALT levels, and HBsAg in 20 patients (80%) (P less than 0.05), 18 recovered completely, and 2 had a protracted course. In five patients serum alpha 2-PAG levels were similar to those in the control group. On the other hand, eight (100%) chronic persistent HBV patients showed high levels of alpha 2-PAG (P less than 0.05) during the study period, and these levels correlated well with inflammatory activity and failure of HBsAg elimination. There were no significant differences in alpha 2-PAG values between asymptomatic HBsAg carriers and controls. Serial analysis of alpha 2-PAG, in correlation with viral markers, biochemical parameters, and histological data, would contribute to the ability to predict the final outcome of HBV infection.

Serologic study by competitive enzyme-linked immunosorbent assay of pregnancy-associated alpha 2-glycoprotein in hepatitis B virus infection.

Serum levels of pregnancy-associated alpha 2-glycoprotein (alpha 2-PAG) in patients with hepatitis B virus (HBV) infection were compared with those of healthy male subjects used as controls by a competitive enzyme-linked immunosorbent assay (ELISA). Assay parameters were optimized, and minimal detectable concentration was 100 ng/ml. The alpha 2-PAG levels in 22/26 acute HBV patients showed a very significant statistical difference when compared with controls (x2 = 19.93, p less than 0.0005). On the other hand, 8/8 chronic persistent HBV patients showed high levels with a range between 51 to 200 ug/ml (x2 = 18.16, p less than 0.0005). There was no significant difference between asymptomatic HBsAg carriers and controls. Although alpha 2-PAG apparently exhibits immunosuppressive properties similar to other factors present in HBV infection, follow-up studies are needed to elucidate its role in the natural evolution of this disease.

Clobazam en el tratamiento de las epilepsias graves de la infancia / Clobazam in the treatment of severe epilepsy in infancy

Los autores estudiaron 14 pacientes con trastornos convulsivos importantes: espasmos infantiles, crisis secundarias a injurias prenatales y retardo mental, que fueron medicados con Clobazam solo o con otras drogas anticonvulsivantes (principalmente fenobarbital). Clobazam fue efectivo en 64,3% de los niños con severos trastornos convulsivos secundarios. El efecto terapéutico del Clobazam fue más prolongado y los efectos adversos fueron menores. Adicionalmente el Clobazam ha mejorado la conexión psicosocial y el estado de atención de estos pacientes (AU)

Clobazam en el tratamiento de las epilepsias graves de la infancia / Clobazam in the treatment of severe epilepsy in infancy

Los autores estudiaron 14 pacientes con trastornos convulsivos importantes: espasmos infantiles, crisis secundarias a injurias prenatales y retardo mental, que fueron medicados con Clobazam solo o con otras drogas anticonvulsivantes (principalmente fenobarbital). Clobazam fue efectivo en 64,3% de los niños con severos trastornos convulsivos secundarios. El efecto terapéutico del Clobazam fue más prolongado y los efectos adversos fueron menores. Adicionalmente el Clobazam ha mejorado la conexión psicosocial y el estado de atención de estos pacientes

Influence of specificity and affinity of antibodies on the kinetics of a sandwich enzyme immunoassay for human IgG.

In comparative experiments, we desired to determine the influence of specificity and affinity of various combinations of antibodies on the kinetics of a "sandwich" enzyme immunoassay for human IgG. Some antibodies were immobilized and others labeled with glucose oxidase. When antibodies employed were heterogeneous in specificity and affinity, long periods of time were required to reach equilibrium, especially on the second step of the assay. In contrast, when antibodies were separated into populations with specificity towards two different antigenic sites, and each one was used as immunoadsorbent and labeled, time was significantly reduced. Finally, when the assay took place--the last antibodies being selected by their high affinities--the rate of the reaction improved even more. We assume selection of antibodies by specificity and affinity by two antigenic sites as an essential requirement to improve performance of these assays, independently of the antigen and marker used.