Vera Campos

Prevalence of sequelae in the permanent anterior teeth after trauma in their predecessors: a longitudinal study of 8 years

The aim of this study was to determine the prevalence of sequelae in the permanent anterior teeth following trauma in their predecessors, and also to verify the existence of association between the sequelae in the permanent teeth and the type of injury in their predecessors according to the age group at the time of injury. This study was performed based on data from the records of 169 boys and 138 girls who received assistance at the dental clinic of the State University of Rio de Janeiro from March 1996 to December 2004. The sample was collected from 753 traumatized deciduous teeth of children aged 0-10 years. The number of boys and girls with dental trauma corresponded to 55.0% and 45.0%, respectively. The more affected age period was between 1 and 4 years (75.3%). The most common type of traumatic injury was the intrusion (29.3%), followed by avulsion (14.1%). Concerning permanent dentition, the most common developmental disturbances were discoloration of enamel and/or enamel hypoplasia (46.08%) and eruption disturbances (17.97%) due to the traumatic injury in their predecessors. It was not possible to find an association between the type of injury in primary teeth and sequelae in their successors in the studied age groups (P </= 1.00). The study concluded that discolorations of enamel and/or enamel hypoplasia (46.08%) were the most prevalent sequelae on the permanent dentition and that there was no significant statistical association between the occurrence of sequelae in the permanent teeth and the type of traumatic injury in their predecessors in the studied age groups.

Frequency of intrusive luxation in deciduous teeth and its effects

The aims of this study were three-fold: First, to determine the prevalence of partial and total intrusion of the primary anterior teeth. Second, to investigate the sequelae of total and partial intrusive luxation in the primary anterior teeth and in their successors and finally, to establish whether the sequelae on both deciduous and permanent teeth were related to the childs age at the time of the intrusion. Data collected from records of 169 boys and 138 girls, all between the ages of zero and 10 years, who were undergoing treatment during the period of March 1996 to December 2004. The sample was composed of 753 traumatized deciduous teeth, of which 221 presented intrusive luxation injury. Children with ages ranging from one to 4 years were the most affected with falls being the main cause of intrusion. Of all intruded teeth 128 (57.9%) were totally intruded and 93 (42.1%) partially. Pulp necrosis/premature loss and color change were the most frequent sequelae in both total and partial intrusions. Concerning permanent dentition, the most common disturbances were color change and/or enamel hypoplasia. Both types of intrusion caused eruption disturbance. Total intrusion was the most frequent type of intrusive luxation. There was no significant correlation between the childs age at the time of intrusion and the frequency of subsequent sequela on primary injured teeth (P = 0.035), between the age at the time of injury and the developmental disturbances on permanent teeth (P = 0.140).

Chemotherapy and radiation regimens to breast cancer treatment induce changes in mRNA levels of renin-angiotensin system related genes in cardiac tissue

Background and aim: Cardiovascular complications are one limitation of breast cancer treatment. The aim of the current study was to investigate whether the renin–angiotensin related genes could be altered by chemotherapy and radiotherapy, using a rat model. Methods: Female rats were divided into three groups: control, chemotherapy + irradiation (TC+IR) and irradiation (IR). Molecular analyses of the left ventricle were performed five months after the end of treatment. The analyses evaluated the changes in mRNA levels of some renin–angiotensin system (RAS) related genes: angiotensinogen, renin, angiotensin-converting enzyme (ACE) and angiotensin II type 1 receptor (AT1) and vascular endothelial growth factor (VEGF), which can be related to ACE production, by RT-PCR. Results: Renin was only observed in treated groups, TC+IR and IR, compared with the control group. ACE and VEGF levels were decreased in TC+IR (p<0.001) and in IR (p<0.001), and AT1 mRNA was higher in groups TC+IR (p<0.01) and IR (p<0.05) compared with the control group. Conclusion: Chemotherapy and irradiation can induce significant changes in some RAS related genes. These alterations are important to understand the pathways and consequences beyond cardiotoxicity induced by breast cancer treatments.

DNA damage in blood cells exposed to low-level lasers

In regenerative medicine, there are increasing applications of low‐level lasers in therapeutic protocols for treatment of diseases in soft and in bone tissues. However, there are doubts about effects on DNA, and an adequate dosimetry could improve the safety of clinical applications of these lasers. This work aimed to evaluate DNA damage in peripheral blood cells of Wistar rats induced by low‐level red and infrared lasers at different fluences, powers, and emission modes according to therapeutic protocols.

Low-intensity infrared lasers alter actin gene expression in skin and muscle tissue

The biostimulative effect of low-intensity lasers is the basis for treatment of diseases in soft tissues. However, data about the influence of biostimulative lasers on gene expression are still scarce. The aim of this work was to evaluate the effects of low-intensity infrared lasers on the expression of actin mRNA in skin and muscle tissue. Skin and muscle tissue of Wistar rats was exposed to low-intensity infrared laser radiation at different fluences and frequencies. One and 24 hours after laser exposure, tissue samples were withdrawn for total RNA extraction, cDNA synthesis and evaluation of actin gene expression by quantitative polymerase chain reaction. The data obtained show that laser radiation alters the expression of actin mRNA differently in skin and muscle tissue of Wistar rats depending of the fluence, frequency and time after exposure. The results could be useful for laser dosimetry, as well as to justify the therapeutic protocols for treatment of diseases of skin and muscle tissues based on low-intensity infrared laser radiation.

Caspase-3 activation and increased procollagen type I in irradiated hearts

The caspase-3-cleaved presence was evaluated in this study in the heart of irradiated rats, during the decline of ventricular function. Female Wistar rats were irradiated with a single dose of radiation (15 Gy) delivered directly to the heart and the molecular, histological and physiological evaluations were performed at thirteen months post-irradiation. The expressions of procollagen type I, TGF-ß1 and caspase-3-cleaved were analyzed using Western blotting. Cardiac structural and functional alterations were investigated by echocardiography and electron microscopy. In the irradiated group, the levels of procollagen type I, TGF-ß1 and caspase-3-cleaved are increased. Significant histological changes (degeneration of heart tissue and collagen deposition) and functional (reduced ejection fraction) were observed. Data suggest that the cardiac function decline after exposure to ionizing radiation is related, in part, to increased collagen and increased caspase-3-cleaved.

DNA fragmentation and nuclear phenotype in tendons exposed to low-intensity infrared laser

Clinical protocols are recommended in device guidelines outlined for treating many diseases on empirical basis. However, effects of low-intensity infrared lasers at fluences used in clinical protocols on DNA are controversial. Excitation of endogenous chromophores in tissues and free radicals generation could be described as a consequence of laser used. DNA lesions induced by free radicals cause changes in DNA structure, chromatin organization, ploidy degrees and cell death. In this work, we investigated whether low-intensity infrared laser therapy could alter the fibroblasts nuclei characteristics and induce DNA fragmentation. Tendons of Wistar rats were exposed to low-intensity infrared laser (830 nm), at different fluences (1, 5 and 10 J/cm2), in continuous wave (power output of 10mW, power density of 79.6 mW/cm2). Different frequencies were analyzed for the higher fluence (10 J/cm2), at pulsed emission mode (2.5, 250 and 2500 Hz), with the laser source at surface of skin. Geometric, densitometric and textural parameters obtained for Feulgen-stained nuclei by image analysis were used to define nuclear phenotypes. Significant differences were observed on the nuclear phenotype of tendons after exposure to laser, as well as, high cell death percentages was observed for all fluences and frequencies analyzed here, exception 1 J/cm2 fluence. Our results indicate that low-intensity infrared laser can alter geometric, densitometric and textural parameters in tendon fibroblasts nuclei. Laser can also induce DNA fragmentation, chromatin lost and consequently cell death, using fluences, frequencies and emission modes took out from clinical protocols.