Bone healing in drill hole defects in spontaneously hypertensive male and female rats' femurs. A histological and histometric study

Objective: the aim of this study was to evaluate the bone healing in spontaneously hypertensive rats (SHR) and compare the results with normotensive rats, evaluating male and female animals.Methods: A bone drill defect was created in the left femur of 24 SHR (12 males and 12 females) and 24 normotensive rats (12 males and 12 females). The animals were divided into two groups and sacrificed 7 and 21 days after the surgical procedure. After the routine laboratory processing, histological and histometric analysis were carried out and data were submitted to ANOVA and Tukey's test (5%).Results: Males and females from the same group had similar histological characteristics. After seven days, all animals presented irregular bone trabeculae. The periosteal osteoblasts were flattened in SHR, and presented a cuboid shape in normotensive animals. After 21 days, the bone defects of all specimens showed a linear closure in all the superficial extension. In addition, SHR presented flattened osteoblasts surrounding the bone trabeculae, while normotensive ones showed cuboidal cells. Statistical analysis of the histometric data indicated similar means between the male and female groups, except for normotensive rats on day 7. In addition, a larger amount of new bone formation was observed in hypertensive when compared to normotensive rats on day 27, in males as well as females.Conclusion: We conclude that bone healing in SHR was more significant than in normotensive ones, as shown by the histological and histometric evaluation 21 days after surgery.

Photosensitization of different Candida species by low power laser light

The aim of this study was to evaluate the effects of the laser radiation (685 nm) associated with photosensitizers on viability of different species of Candida genus. Suspensions of Candida albicans, Candida dubliniensis, Candida krusei and Candida tropicalis, containing 106 viable cells per milliliter were obtained with the aid of a Neubauer's chamber. From each species, 10 samples of the cell suspension were irradiated with diode laser (685 nm) with 28 J/cm(2) in the presence of methylene blue (0.1 mg/ml), 10 samples were only treated with methylene blue, 10 samples were irradiated with laser in the absence of the dye, 10 samples were treated with the dye and irradiated with laser light and 10 samples were exposed to neither the laser light nor to the methylene blue dye. From each sample, serial dilutions of 10(-2) and 10(-3) were obtained and aliquots of 0.1 ml of each dilution were plated in duplicate on Sabouraud dextrose agar. After incubation at 37 degrees C for 48 h, the number of colony-forming units (CFU/ml) was obtained and data were submitted to ANOVA and Tukey's test (p < 0.05). Laser radiation in the presence of methylene blue reduced the number of CFU/ml in 88.6% for C. albicans, 84.8% for C. dubliniensis, 91.6% for C krusei and 82.3% for C tropicalis. Despite of this, only laser radiation or methylene blue did not reduce significantly the number of CFU/ml of Candida samples, except for C tropicalis. It could be concluded that the photo activation of methylene blue by the red laser radiation at 685 nm presented fungicide effect on all Candida species studied. (c) 2006 Elsevier B.V. All rights reserved.

New anti-Alzheimer drugs from biodiversity: the role of the natural acetylcholinesterase inhibitors

Alzheimer's disease (AD) is a progressive neurodegenerative pathology with severe economic and social impact. There is currently no cure, although cholinesterase inhibitors provide effective temporary relief of symptoms in some patients. Nowadays, drug research and development are based on the cholinergic hypothesis that supports the cognition improvement by regulation of the synthesis and release of acetylcholine in the brain. There are only four commercial medicines approved for treatment of AD, and natural products have played an important alternative role in the research for new acetylcholinesterase inhibitors, as exemplified through the discovery of galantamine. This profile conducts us to give in this paper an overview relating the several classes of natural products with anti-cholinesterasic activity as potential templates to the design of new selective and powerful anti-Alzheimer drugs.