Efecto de la terapia láser de baja potencia sobre el hueso alveolar dañado / The low level laser therapy effect on alveolar bone damaged

La terapia con láser de baja potencia ha demostrado tener propiedades analgésicas antiinflamatorias, bioestimulantes y promotoras de la respuesta tisular al daño. El propósito de este estudio fue determinar el efecto que el láser de baja potencia tiene sobre el hueso alveolar dañado. Se utilizaros 13 ratas Sprage Dawley, en las cuales se realizó una lesión estandarizada del hueso alveolar, posterior a lo cual una muestra aleatoria de 7 ratas fue sometida a un protocolo de irradiación de 6 J/cm2, tres veces por semana durante cuatro semanas. Las muestras obtenidas del sitio lesionado en ratas expuestas y no expuestas a la terapia fueron procesadas para hematoxilina eosina, contabilizándose el número de osteonas al microscopio óptico con aumento de 40x. Los resultados muestran un aumento en el número de osteonas en el grupo irradiado, diferencia que resultó estadísticamente significativa (p<0,01), con una alta fuerza de asociación estadística (O.R=5,6 ). Estos resultados sugieren que la terapia láser de baja potencia favorece la respuesta del hueso alveolar dañado.

The Low Level Laser Therapy (LLLT) has demostrated to have analgesic, antiinflamatory, bioestimulant and promoters from the tissues responses properties to the damage. The purpose of this study was determinate the Low Level Laser Therapy effect in the damaged alveolar bone. Thirteen Sprage Dawley rats were used. Total number of animals alveolar bones a standarized lesion was made, later an aleatory sample of seven rats was subjected to the irradiation protocol 6 J/cm², three times per week during four weeks. The obtained samples of the injured area, of exposed and not exposed rats to the laser therapy were processed for hematoxilin & eosin, being the osteon number count by optic microscope with increase of 40x. The result show an increase in the osteon number in the irradiated group, this differentiated was statistically significant (p<0.01), whit a high strength of statistical association (OR=5.6). These result suggest that the therapy laser of low power favors the answer of the damaged alveolar bone.

Developmental regulation of the base excision repair enzyme uracil DNA glycosylase in the rat.

The developmental regulation of the mammalian DNA-repair enzyme uracil DNA glycosylase was examined in the rat at specific intervals ranging from -4 days before to 106 days after birth. Enzyme activity was quantitated by in vitro biochemical assay. In the adult animal, as measured in crude cell extracts, three organs (liver, kidney and spleen) had significant levels of activity. In contrast, three organs (brain, heart and lung) had low activity. Partial purification of this enzyme identified one major species of molecular weight 32,700 Da, demonstrating the quantitation of the nuclear glycosylase. During development, with the exception of the liver, the specific activity of the glycosylase paralleled the regulation of DNA synthesis. In these organs the highest levels of the glycosylase and the rate of DNA replication were observed around the time of birth. In the liver, DNA replication was similarly regulated. However, glycosylase activity was minimal at early stages of life. Instead, maximal levels were observed at 14-21 days after birth. At that time DNA replication was severely reduced. These results demonstrate that individual organs express this DNA-repair enzyme in a distinct and specific pattern during development. Accordingly, the regulation of the uracil DNA glycosylase during development may provide a model system to examine the differential regulation of DNA-repair genes.

[Inhalation of organic solvents during the last third of pregnancy in Sprague-Dawley rats. Somatometric and cerebellar consequences in newborn animals]. / Inhalación de solventes orgánicos durante el último tercio del embarazo de ratas Sprague-Dawley. Consecuencias somatométricas y cerebelosas en neonatos.

Cerebellar morphogenesis as well as somatometric parameters of progenies from mothers exposed to ethyl-ether, chloroform, turpentine or thinner were registered a 24, 48 and 7 hours of age. 1. Mortality rate of 20 and 59% was observed in progenies of thinner or turpentine exposed mothers, correspondingly. 2. Delay of intrauterine growth manifested by body weight, size and cephalic diameter was evident in chloroform exposed groups (P < 0.01). 3. Cerebellar maturation delay was found in thinner or turpentine prenatally exposed litters. 4. The number of Purkinje cells was significantly reduced in ethyl-ether and chloroform exposed groups (P < 0.01). These cells were found less affected by thinner or turpentine exposure (P < 0.01).

Effects of intramuscular sulfadoxine-pyrimethamine (fansidar) administered to pregnant Sprague Dawley rats on some tissue enzymes in the gonads of their litters

Sulphadoxine-pyrimethamine preparations are antimalaria drugs which owe their efficacy to their antifolate properties. Folates are essential for DNA synthesis and their deficiency at critical periods in gestation have been shown to be teratogenic in variious animals including man. This experiment has shown that, when administered to Sprague Dawley rats at certain periods in gestation, the activities of some enzymes essential for gonadonal steroidogenesis, such as delta 5-3-beta hydroxysteroid dehydrogenase (delta 5-3(HSD), 17-beta hydroxysteroid dehydrogenase (17 beta-HSD), and Glucose-6-phosphate dehydrogenase (G-6-PD) were found to be significantly reduced in the gonads of their litters (AU)