Long-term safety of OnabotulinumtoxinA treatment in chronic migraine patients: a five-year retrospective study.

Background: Real-world studies have shown the sustained therapeutic effect and favourable safety profile of OnabotulinumtoxinA (BoNTA) in the long term and up to 4 years of treatment in chronic migraine (CM). This study aims to assess the safety profile and efficacy of BoNTA in CM after 5 years of treatment in a real-life setting. Methods: We performed a retrospective chart review of patients with CM in relation to BoNTA treatment for more than 5 years in 19 Spanish headache clinics. We excluded patients who discontinued treatment due to lack of efficacy or poor tolerability. Results: 489 patients were included [mean age 49, 82.8% women]. The mean age of onset of migraine was 21.8 years; patients had CM with a mean of 6.4 years (20.8% fulfilled the aura criteria). At baseline, patients reported a mean of 24.7 monthly headache days (MHDs) and 15.7 monthly migraine days (MMDs). In relation to effectiveness, the responder rate was 59.1% and the mean reduction in MMDs was 9.4 days (15.7 to 6.3 days; p < 0.001). The MHDs were also reduced by 14.9 days (24.7 to 9.8 days; p < 0.001). Regarding the side effects, 17.5% experienced neck pain, 17.3% headache, 8.5% eyelid ptosis, 7.5% temporal muscle atrophy and 3.2% trapezius muscle atrophy. Furthermore, after longer-term exposure exceeding 5 years, there were no serious adverse events (AE) or treatment discontinuation because of safety or tolerability issues. Conclusion: Treatment with BoNTA led to sustained reductions in migraine frequency, even after long-term exposure exceeding 5 years, with no evidence of new safety concerns.

Study of umbelliferone hydroxylation to esculetin catalyzed by polyphenol oxidase.

We characterize umbelliferone, a derivative of 2,4-dihydroxycoumaric acid, as a substrate of polyphenol oxidase. This enzyme hydroxylates umbelliferone to esculetin, its o-diphenol, and then oxidizes it to o-quinone. The findings show that umbelliferone, an intermediate in one of the coumarin biosynthesis pathways, may be transformed into its o-diphenol, esculetin, which is also an intermediate in the same pathway. The activity of the enzyme on umbelliferone was followed by measuring the consumption of oxygen, spectrophotometrically and by HPLC. Kinetic constants characterizing the hydroxylation process were: kcat=0.09±0.02 s(-1) and Km=0.17±0.06 mM. The o-diphenol, esculetin, was a better substrate and when its oxidation was followed spectrophotometrically, the kinetic constants were: kcat=1.31±0.25 s(-1) and Km=0.035±0.002 mM. Both compounds therefore can be considered as alternative substrates to L-tyrosine and L-3,4-dihydroxyphenylalanine (L-DOPA), since both indirectly inhibit melanogenesis.

Melanogenesis inhibition due to NADH.

The effect of NADH on melanogenesis under aerobic conditions involves three types of reaction: (a) acting as tyrosinase substrate (a competitive substrate of L-tyrosine and L-DOPA), (b) irreversible inactivation acting as a suicide substrate of tyrosinase, and (c) non-enzymatic reduction of o-dopaquinone by NADH. Under anaerobic conditions, NADH irreversibly inhibits the enzymatic forms met-tyrosinase and deoxy-tyrosinase. In this paper, we kinetically characterize this coenzyme as it acts as a tyrosinase suicide substrate and propose a kinetic mechanism to explain its oxidation by tyrosinase. In addition, the compound is characterized as an irreversible inhibitor of met-tyrosinase and deoxy-tyrosinase.

Effects of tetrahydropterines on the generation of quinones catalyzed by tyrosinase.

Tetrahydrobiopterine (6BH(4)) can diminish the oxidative stress undergone by keratinocytes and melanocytes by reducing the o-quinones generated by the oxidation of the corresponding o-diphenols. We found that 6BH(4) and their analogs reduced all the o-quinones studied. The formal potentials of different quinone/diphenol pairs indicate that the o-quinones with withdrawing groups are more potent oxidants than those with donating groups.

Capacidad de la alfa-fetoproteína en suero materno como marcador predictivo de parto pretérmino / Capacity of alpha-fetoprotein in maternal serum as a marker predictive of preterm delivery

Determinar el papel de la alfa-fetoproteína como predictora de parto pretérmino. Estudio clínico, de cohorte, no experimental realizado en 170 pacientes, 85 con factores de riesgo de parto pretérmino (grupo estudio), y 85 pacientes sin factores de riesgo de parto pretérmino y sin patología (grupo control). A las pacientes se les tomó una muestra de sangre a las 24 y 28 semanas para evaluar los niveles de alfa-fetoproteína. Servicio de Perinatología, Hospital "Dr. Adolfo Prince Lara", Puerto Cabello. Encontramos una asociación entre el aumento de los valores de alfa-fetoproteína en suero materno y el parto pretérmino. X² = 19,30 P< 0,05, RR = 8 IC 95 por ciento (2,50-25,57), RA = 24,71 IC 95 por ciento (14,36-35,05), sensibilidad = 79,41 por ciento, especificidad = 81,62 por ciento, VPP = 51,92 por ciento, VPN = 94,07 por ciento, prevalencia = 20 por ciento, exactitud = 80,51 por ciento, coeficiente de correlación -0,069. La alfa-fetoproteína tiene capacidad predictiva de parto pretérmino; se recomienda su utilización en el embarazo de riesgo de parto pretérmino

To determine the role of alpha-fetoprotein as predictor or preterm delivery. Clinical, cohort, no experimental study performed in 170 patients, 85 with risk factors for preterm delivery (study group), and 85 patients with no risk factors for preterm delivery and no pathology (control group). A blood sample was taken at 24 and 28 weeks of pregnancy to evaluate alpha-fetoprotein levels. Perinatology Unit, Hospital "Dr. Adolfo Prince Lara", Puerto Cabello. We found an association between the increase of alpha-fetoprotein levels in maternal serum and preterm delivery. X² = 19.30 P< 0.05, RR = 8 IC 95 percent (2.50-25.57), RA = 24.71 IC 95 percent (14.36-35.05), sensibility = 79.41 percent, specificity = 81.62 percent, VPP = 51.92 percent, VPN = 94.07 percent, prevalence = 20 percent, exactness = 80,51 percent, correlation coefficient -0.069. The alpha-fetoprotein has predictive capacity for preterm delivery; we recommend its use in pregnancies with risk of preterm delivery

Kinetic characterization of the oxidation of carbidopa and benserazide by tyrosinase and peroxidase.

Carbidopa and benserazide have been described as inhibitors of dopa decarboxylase and both have been used in the treatment of Parkinson's disease. Because of their chemical structure as polyphenols, these compounds can behave as substrates of tyrosinase and peroxidase. We demonstrate that these enzymes oxidize both substrates. Since o-quinones are unstable, a chronometric method for enzymatic initial rate determinations was used based on measurements of the lag period in the presence of micromolar concentrations of ascorbic acid to kinetically characterize these substrates. In the case of tyrosinase, the values of the Michaelis constant for both substrates were greater than those described for dopa, although the catalytic constants were lower, probably due to the greater size of the substitute group in carbon 1. As regards peroxidase, the saturation of the enzyme by both substrates is possible, however this effect does not occur with the isomers of dopa. The distance of the charges from the benzene ring may enable the ring to approach the iron of the active site and, therefore, act.

Valores normales de las alfa-fetoproteínas en embarazadas a las 24 y 28 semanas de gestación

Obtener los valores normales de las alfafetoproteínas en embarazadas a las 24 y 28 semanas de gestación, con el fin de utilizar estos como cifras referenciales en embarazo de riesgo de parto pretérmino. Estudio prospectivo longitudinal, no experimental, en 80 embarazadas atendidas entre enero y noviembre 2005. Se determinaron las alfa-fetoproteínas con la técnica Elisa. El valor medio de las alfa-fetoproteínas a las 24 semanas fue 112 ng/mL y 133 ng/ml a las 28 semanas de gestación, y con rangos de 60 ng/mL en el percentil 10 y 200 ng/ml en el percentil 90 a las 24 semanas, y rangos de 82 ng/mL en el percentil 10 y 230 ng/mL en el percentil 90 a las 28 semanas de gestación. Se dispone de cifras referenciales de alfa-fetoproteínas como parámetro que puede ser utilizado como pronóstico en el embarazo de riesgo de parto pretérmino

To obtain the normal values of alpha-fetoprotein, between 24-28 weeks of pregnancy, to be use as levels of reference in the pregnancies with preterm delivery risk. Longitudinal prospective study, non experimental, in 80 pregnant women attended between January to November 2005. alpha-fetoprotein was determined by the Elisa technic. The alpha-fetoprotein mean values oscilated between 112 ng/mL at 24 weeks and 133 ng/mL at 28 weeks, and in the percentile distribution with ranges of 60 ng/mL in the percentile 10 and 200 ng/mL in the percentile 90 at the 24 weeks. At 28 weeks the range were 82 ng/mL in the percentile 10 and 230 ng/mL in the 90 percentile. We have at one’s disposal alpha-fetoprotein values as a parameter to be used as pronostique in the high risk pregnancy of preterm delivery

Kinetic characterization of the oxidation of esculetin by polyphenol oxidase and peroxidase.

Esculetin has been described as an inhibitor of tyrosinase and polyphenol oxidase and, therefore, of melanogenesis. In this work, we demonstrate that esculetin is not an inhibitor but a substrate of mushroom polyphenol oxidase (PPO) and horseradish peroxidase (POD), enzymes which oxidize esculetin, generating its o-quinone. Since o-quinones are very unstable, the usual way of determining the enzymatic activity (slope of recordings) is difficult. For this reason, we developed a chronometric method to characterize the kinetics of this substrate, based on measurements of the lag period in the presence of micromolar concentrations of ascorbic acid. The catalytic constant determined was of the same order for both enzymes. However, polyphenol oxidase showed greater affinity (a lower Michaelis constant) than peroxidase for esculetin. The affinity of PPO and POD towards oxygen and hydrogen peroxide was very high, suggesting the possible catalysis of both enzymes in the presence of low physiological concentrations of these oxidizing substrates. Taking into consideration optimum pHs of 4.5 and 7 for POD and PPO respectively, and the acidic pHs of melanosomes, the studies were carried out at pH 4.5 and 7. The in vivo pH might be responsible for the stronger effect of these enzymes on L-tyrosine and L-3,4-dihydroxyphenylanaline (L-DOPA) (towards melanogenesis) and on cumarins such as esculetin towards an alternative oxidative pathway.

Prueba de la desnaturalización alcalina de la hemoglobina en obstetricia / Alcaline denaturation test of the hemoglobin in obstetrics

Evaluar prospectivamente la utilidad de la prueba de la desnaturalización alcalina con hidróxido de sodio en la identificación de la hemoglobina fetal y del adulto. El fundamento de la prueba es la propiedad de la hemoglobina fetal de ser resistente a la desnaturalización alcalina y a la fragilidad de la hemoglobina del adulto. Se recolectaron 100 muestras de sangre del cordón umbilical y 100 de mujeres no embarazadas. Se prepararon hemolizados que fueron sometidos a concentración variable de hidróxido de sodio 0,2 N; 0,4 N; 0,6 N; y 0,8 N para determinar cúal era la de mayor utilidad discriminativa. A un grupo de 80 hemolizados, codificados y aleatorios (40 adulto y 40 fetal), se sometieron a identificación de manera ciega con observadores voluntarios. Hospital "Dr. Adolfo Prince Lara", Puerto Cabello, Edo. Carabobo. El hidróxido de sodio 0,2 N fue la concentración que más evidentemete deslindó las hemoglobinas estudiadas al valorar el tiempo y cambio de color inducido (p< 0,001). Todos los hemolizados adultos y fetales probados en ensayos ciegos, fueron identificados correctamente al emplear hidróxido de sodio 0,2 N. La prueba de desnaturalización de la hemoglobina con hidróxido de sodio al 0,2 N es una prueba sencilla, rápida, económica y segura en la identificación de la hemoglobina fetal y la adulta