Daniel Martins Pereira

Effect of Low‐Level Laser Therapy (660 nm) on Acute Inflammation Induced by Tenotomy of Achilles Tendon in Rats

In this study, we aimed to analyze the effects of low‐level laser therapy (LLLT; 660 nm) on levels of protein expression of inflammatory mediators after cutting Achilles tendon of rats. Thirty Wistar male rats underwent partial incisions of the left Achilles tendon, and were divided into three groups of 10 animals according to the time of euthanasia after injury: 6, 24 and 72 h. Each group was then divided into control group and LLLT group (treated with 100 mW, 3.57 W cm−2, 0.028 cm2, 214 J cm−2, 6 J, 60 s, single point). In LLLT group, animals were treated once time per day until the time of euthanasia established for each group. The group treated with LLLT showed a significant reduction of IL‐1β compared with control groups at three time points (6 h: P = 0.0401; 24 h: P = 0.0015; 72 h: P = 0.0463). The analysis of IL‐6 showed significant reduction only in the LLLT group at 72 h compared with control group (P = 0.0179), whereas IL‐10 showed a significant increase in the treated group compared with control group at three experimental times (6 h: P = 0.0007; 24 h: P = 0.0256; 72 h: P < 0.0001). We conclude that LLLT is an important modulator of inflammatory cytokines release after injury in Achilles tendon.

Experimental model of pulmonary carcinogenesis in Wistar rats

PURPOSE To elaborate an experimental model of pulmonary carcinogenesis in Wistar rats. METHODS Male Rattus norvegicus albinus, Wistar lineage were carried through an intra-pulmonary instillation of the Benzo[a]pyrene (B[a]P) dilution in alcohol 70%, a polycyclic aromatic hydrocarbon widely known by its power of tumoral induction. Three experimental groups had been formed with 08 animals each: Control Group (Alcohol 70%); B[a]P Group 10 mg/kg; e B[a]P Group 20mg/kg, submitted to euthanasia 08, 10, 12 and 14 weeks after the experimental procedure. The pulmonary sections had been colored by hematoxilin-eosin (HE) and submitted to the morphometrical analysis to describe the tissue alterations. RESULTS The presence of diffuse inflammatory alterations was observed in all groups; however, at the analysis of the pulmonary tissue of the experimental groups had been observed hyperplasic alterations (BALT hyperplasia), and in one of the animals of the experimental group 20mg/kg (12 weeks) was noticed the presence of cellular epithelial tracheal pleomorphism, suggesting the adenocarcinoma formation in situ. CONCLUSION The main secondary alterations to the intra-pulmonary instillation of B[a]P in Wistar rats were: cellular proliferation, inflammatory alterations of several degrees and nodular lymphoid hyperplasias. The association of an activator agent of the pulmonary metabolic reply is necessary to establish the ideal reply-dose to the development of the lung cancer.

Usefulness of argyrophilic nucleolar organizer regions in detection of lung cells alterations after benzo[a]pyrene instillation

PURPOSE To verify the relationship between AgNOR expression and lung tissues changes of Wistar rats after pulmonary instillation of benzo[a]pyrene (B[a]P). METHODS Male Rattus norvegicus albinus,Wistar lineage were given a single intrapulmonary instillation of B[a]P at doses of 10 and 20 mg/kg in a volume of approximately 0.3 ml. After 7 and 21 days the rats were killed and the lung slices submitted to a histological technique of AgNOR. AgNOR dots were quantified and the result analyzed by statistical tests; p < or = 0.05 was considered significant. RESULTS The mean values of AgNOR dots for the experimental groups 10/7 (1.51+/-0.86) and 10/21 (1.84+/-0.13) were statistically different (p = 0.009). Among the groups 20/7 (1.63+/-0.11) and 20/21 (2.48+/-0.28) was observed statistically significant difference (p = 0.003). CONCLUSION The AgNOR technique can be useful in identification of cells changes induced by B[a]P.

Ischemia and reperfusion of rat small intestine using pentoxyfilline and prostaglandin E1

PURPOSE To investigate the small intestinal tissue alterations in rats submitted to ischemia and tissue reperfusion using pentoxyfilline or prostaglandin E1. METHODS Thirty five Wistar rats were used, distributed into group control (A) n=10 were submitted to intestinal ischemia and reperfusion during 60 minutes and no one drug have been utilized. In the group pentoxyfilline (B) n=10 have been utilized during tissue ischemia and reperfusion as well as prostaglandin E1 (C) n=10, but separately. In the group sham (D) n=5, the animals were submitted to surgical. After euthanasia of the animals, a segment of the small intestine was cut, stained by hematoxilin-eosin and histological analysis according to Chiu criteria. RESULTS Histological results showed that using pentoxyflline or prostaglandin E1 the results during tissue reperfusion were better, since the levels of criteria from Chiu that predominated were level 2 and 3, indicating less tissue damage in comparison to the control group (group A) that showed levels 4 and 5, what means more severe histological tissue alterations. CONCLUSION Use of pentoxyfilline or prostaglandin E1 promoted a beneficial effect during intestinal reperfusion, demonstrated by less severe histological lesions in the small intestine mucosa of rats submitted to ischemia and tissue reperfusion when helped by the drugs.

Pulmonary emphysema induced by methylphenidate: experimental study

CONTEXT AND OBJECTIVE Methylphenidate is the most widely used drug for treating attention deficit hyperactivity disorder. However, it has important side effects, such as abdominal pain, insomnia, anorexia and loss of appetite, and also some cases of early severe emphysema after drug abuse have been reported. Our aim was to investigate the development of pulmonary emphysema in rats that were subjected to different doses of methylphenidate. DESIGN AND SETTING Experimental study carried out at the laboratory of a public university. METHODS Eighteen male Wistar rats were divided into three groups: control (0.9% saline solution); MP 0.8 (methylphenidate, 0.8 mg/kg); MP 1.2 (methylphenidate, 1.2 mg/kg). After 90 days of daily gavage, the animals were sacrificed and lung tissue samples were prepared for analysis on the mean alveolar diameter (Lm). RESULTS The Lm was greater in MP 0.8 (47.91 ± 3.13; P < 0.01) and MP 1.2 (46.36 ± 4.39; P < 0.05) than in the control group (40.00 ± 3.48). CONCLUSION Methylphenidate caused an increase in the alveolar diameter of rats, which was compatible with human pulmonary emphysema.