Arm regeneration in two populations of Ophionereis reticulata (Echinodermata, Ophiuroidea)

This study compared the arm regeneration frequencies in two different populations of Ophionereis reticulata (Say, 1825) in Sao Sebastiao, Southeast Brazil and observed arm regeneration between age classes (juvenile and adults) and sexes (male and female). From the 1,170 individuals sampled, 1,089 (92.2%) showed signs of arm regeneration. The relative frequencies of regenerating arms in the two areas were not different (Baleeiro Isthmus: 91.3% and Grande Beach: 99.5%). Both areas also presented similar values for the number of arms regenerating/individual and in the frequency of regenerating individuals. The major part of the regenerating scars was concentrated in the distal portion of the arm. Sub-lethal predation is most likely the cause to the high rates of arm regeneration in O. reticulata. There was no significant differences in the regeneration rates between females (3.57 +/- 1.36 arms regenerating/individual) and males (3.47 +/- 1.42).

Effect of a low-level laser on bone regeneration after rapid maxillary expansion

Introduction: In this study, we evaluated the effects of a low-level laser on bone regeneration in rapid maxillary expansion procedures. Methods: Twenty-seven children, aged 8 to 12 years, took part in the experiment, with a mean age of 10.2 years, divided into 2 groups: the laser group (n=14), in which rapid maxillary expansion was performed in conjunction with laser use, and the no-laser group (n=13), with rapid maxillary expansion only. The activation protocol of the expansion screw was 1 full turn on the first day and a half turn daily until achieving overcorrection. The laser type used was a laser diode (TWIN Laser; MMOptics, Sao Carlos, Brazil), according to the following protocol: 780 nm wavelength, 40 mW power, and 10 J/cm(2) density at 10 points located around the midpalatal suture. The application stages were 1 (days 1-5 of activation), 2 (at screw locking, on 3 consecutive days), 3, 4, and 5 (7, 14, and 21 days after stage 2). Occlusal radiographs of the maxilla were taken with the aid of an aluminum scale ruler as a densitometry reference at different times: T1 (initial), T2 (day of locking), T3 (3-5 days after T2), T4 (30 days after T3), and T5 (60 days after T4). The radiographs were digitized and submitted to imaging software (Image Tool; UTHSCSA, San Antonio, Tex) to measure the optic density of the previously selected areas. To perform the statistical test, analysis of covariance was used, with the time for the evaluated stage as the covariable. In all tests, a significance level of 5% (P<0.05) was adopted. Results: From the evaluation of bone density, the results showed that the laser improved the opening of the midpalatal suture and accelerated the bone regeneration process. Conclusions: The low-level laser, associated with rapid maxillary expansion, provided efficient opening of the midpalatal suture and influenced the bone regeneration process of the suture, accelerating healing. (Am J Orthod Dentofacial Orthop 2012;141:444-50)

GaAs 904-nm laser irradiation improves myofiber mass recovery during regeneration of skeletal muscle previously damaged by crotoxin

This work investigated the effect of gallium arsenide (GaAs) irradiation (power: 5 mW; intensity: 77.14 mW/cm(2), spot: 0.07 cm(2)) on regenerating skeletal muscles damaged by crotoxin (CTX). Male C57Bl6 mice were divided into six groups (n = 5 each): control, treated only with laser at doses of 1.5 J or 3 J, CTX-injured and, CTX-injured and treated with laser at doses of 1.5 J or 3 J. The injured groups received a CTX injection into the tibialis anterior (TA) muscle. After 3 days, TA muscles were submitted to GaAs irradiation at doses of 1.5 or 3 J (once a day, during 5 days) and were killed on the eighth day. Muscle histological sections were stained with hematoxylin and eosin (H&E) in order to determine the myofiber cross-sectional area (CSA), the previously injured muscle area (PIMA) and the area density of connective tissue. The gene expression of MyoD and myogenin was detected by real-time PCR. GaAs laser at a dose of 3 J, but not 1.5 J, significantly increased the CSA of regenerating myofibers and reduced the PIMA and the area density of intramuscular connective tissue of CTX-injured muscles. MyoD gene expression increased in the injured group treated with GaAs laser at a dose of 1.5 J. The CTX-injured, 3-J GaAs laser-treated, and the CTX-injured and treated with 3-J laser groups showed an increase in myogenin gene expression when compared to the control group. Our results suggest that GaAs laser treatment at a dose of 3 J improves skeletal muscle regeneration by accelerating the recovery of myofiber mass.

Differential Expression of Genes Involved in the Degeneration and Regeneration Pathways in Mouse Models for Muscular Dystrophies

The genetically determined muscular dystrophies are caused by mutations in genes coding for muscle proteins. Differences in the phenotypes are mainly the age of onset and velocity of progression. Muscle weakness is the consequence of myofiber degeneration due to an imbalance between successive cycles of degeneration/regeneration. While muscle fibers are lost, a replacement of the degraded muscle fibers by adipose and connective tissues occurs. Major investigation points are to elicit the involved pathophysiological mechanisms to elucidate how each mutation can lead to a specific degenerative process and how the regeneration is stimulated in each case. To answer these questions, we used four mouse models with different mutations causing muscular dystrophies, Dmd (mdx) , SJL/J, Large (myd) and Lama2 (dy2J) /J, and compared the histological changes of regeneration and fibrosis to the expression of genes involved in those processes. For regeneration, the MyoD, Myf5 and myogenin genes related to the proliferation and differentiation of satellite cells were studied, while for degeneration, the TGF-beta 1 and Pro-collagen 1 alpha 2 genes, involved in the fibrotic cascade, were analyzed. The result suggests that TGF-beta 1 gene is activated in the dystrophic process in all the stages of degeneration, while the activation of the expression of the pro-collagen gene possibly occurs in mildest stages of this process. We also observed that each pathophysiological mechanism acted differently in the activation of regeneration, with distinctions in the induction of proliferation of satellite cells, but with no alterations in stimulation to differentiation. Dysfunction of satellite cells can, therefore, be an important additional mechanism of pathogenesis in the dystrophic muscle.

Regeneration and characterization of somatic hybrids combining sweet orange and mandarin/mandarin hybrid cultivars for citrus scion improvement

Protoplast fusion between sweet orange and mandarin/mandarin hybrids scion cultivars was performed following the model "diploid embryogenic callus protoplast + diploid mesophyll-derived protoplast". Protoplasts were isolated from embryogenic calli of 'Pera' and 'Westin' sweet orange cultivars (Citrus sinensis) and from young leaves of 'Fremont', Nules', and 'Thomas' mandarins (C. reticulata), and 'Nova' tangelo [C. reticulata x (C. paradisi x C. reticulata)]. The regenerated plants were characterized based on their leaf morphology (thickness), ploidy level, and simple sequence repeat (SSR) molecular markers. Plants were successfully generated only when 'Pera' sweet orange was used as the embryogenic parent. Fifteen plants were regenerated being 7 tetraploid and 8 diploid. Based on SSR molecular markers analyses all 7 tetraploid regenerated plants revealed to be allotetraploids (somatic hybrids), including 2 from the combination of 'Pera' sweet orange + 'Fremont' mandarin, 3 'Pera' sweet orange + 'Nules' mandarin, and 2 'Pera' sweet orange + 'Nova' tangelo, and all the diploid regenerated plants showed the 'Pera' sweet orange marker profile. Somatic hybrids were inoculated with Alternaria alternata and no disease symptoms were detected 96 h post-inoculation. This hybrid material has the potential to be used as a tetraploid parent in interploid crosses for citrus scion breeding.

Human Fallopian Tube Mesenchymal Stromal Cells Enhance Bone Regeneration in a Xenotransplanted Model

We have recently reported that human fallopian tubes, which are discarded during surgical procedures of women submitted to sterilization or hysterectomies, are a rich source of human fallopian tube mesenchymal stromal cells (htMSCs). It has been previously shown that human mesenchymal stromal cells may be useful in enhancing the speed of bone regeneration. This prompted us to investigate whether htMSCs might be useful for the treatment of osteoporosis or other bone diseases, since they present a pronounced capacity for osteogenic differentiation in vitro. Based on this prior knowledge, our aim was to evaluate, in vivo, the osteogenic capacity of htMSCs to regenerate bone through an already described xenotransplantation model: nonimmunosuppressed (NIS) rats with cranial defects. htMSCs were obtained from five 30-50 years old healthy women and characterized by flow cytometry and for their multipotenciality in vitro capacity (osteogenic, chondrogenic and adipogenic differentiations). Two symmetric full-thickness cranial defects on each parietal region of seven NIS rats were performed. The left side (LS) of six animals was covered with CellCeram (Scaffdex)-a bioabsorbable ceramic composite scaffold that contains 60% hydroxyapatite and 40% beta-tricalciumphosphate-only, and the right side (RS) with the CellCeram and htMSCs (10(6) cells/scaffold). The animals were euthanized at 30, 60 and 90 days postoperatively and cranial tissue samples were taken for histological analysis. After 90 days we observed neobone formation in both sides. However, in animals euthanized 30 and 60 days after the procedure, a mature bone was observed only on the side with htMSCs. PCR and immunofluorescence analysis confirmed the presence of human DNA and thus that human cells were not rejected, which further supports the imunomodulatory property of htMSCs. In conclusion, htMSCs can be used successfully to enhance bone regeneration in vivo, opening a new field for future treatments of osteoporosis and bone reconstruction.

Effect of electromagnetic field on bone regeneration around dental implants after immediate placement in the dog mandible: a pilot study

Background: Accelerating bone healing around dental implants can reduce the long-term period between the insertion of implants and functional rehabilitation. Objective: This in vivo study evaluated the effect of a constant electromagnetic field (CEF) on bone healing around dental implants in dogs. Materials and methods: Eight dental implants were placed immediately after extraction of the first premolar and molar teeth on the mandible of two male dogs and divided into experimental (CEF) and control groups. A CEF at magnetic intensity of 0.8 mT with a pulse width of 25 mu s and frequency of 1.5 MHz was applied on the implants for 20 min per day for 2 weeks. Result and conclusion: After qualitative histological analysis, a small quantity of newly formed bone was observed in the gap between the implant surface and alveolar bone in both groups.

Sciatic nerve regeneration in rats by a nerve conduit engineering with a membrane derived from natural latex

PURPOSE: To evaluate the capacity of natural latex membrane to accelerate and improve the regeneration quality of the of rat sciatic nerves. METHODS: Forty male adult Wistar rats were used, anesthetized and operated to cut the sciatic nerve and receive an autograft or a conduit made with a membrane derived from natural latex (Hevea brasiliensis). Four or eight weeks after surgery, to investigate motor nerve recovery, we analyzed the neurological function by walking pattern (footprints analysis and computerized treadmill), electrophysiological evaluation and histological analysis of regenerated nerve (autologous nerve graft or tissue cables between the nerve stumps), and anterior tibial and gastrocnemius muscles. RESULTS: All functional and morphological analysis showed that the rats transplanted with latex conduit had a better neurological recovery than those operated with autologous nerve: quality of footprints, performance on treadmill (p<0.01), electrophysiological response (p<0.05), and quality of histological aspects on neural regeneration. CONCLUSION: The data reported showed behavioral and functional recovery in rats implanted with latex conduit for sciatic nerve repair, supporting a complete morphological and physiological regeneration of the nerve.

Immunolocalization of bone morphogenetic protein 2 during the early healing events after guided bone regeneration

Objective. The objective of this study was to evaluate the immunolocalization of bone morphogenetic protein 2 (BMP-2) after autogenous block grafting covered or not with an e-PTFE membrane. Study Design. Forty-eight rats were divided into 2 groups, autogenous block graft (B) and autogenous block graft + e-PTFE membrane (MB), and were evaluated by immunohistochemistry at baseline and 3, 7, 14, 21, and 45 days. Results. The largest number of positive cells in the recipient bed was observed after 3 days in both groups. At the graft border, the largest number of positive cells was seen after 7 days in group B and after 14 days in group MB. The highest proportion of staining in the graft was observed after 3 days in group B and after 21 days in group MB. Conclusions. High proportions of stain were related to intense revascularization and osteogenesis. Except for the interface, BMP-2 staining occurred later in group MB than in group B in all structures analyzed. (Oral Surg Oral Med Oral Pathol Oral Radiol 2012;113:533-541)

A bayesian network meta-analysis on comparisons of enamel matrix derivatives, guided tissue regeneration and their combination therapies

Aims: Guided tissue regeneration (GTR) and enamel matrix derivatives (EMD) are two popular regenerative treatments for periodontal infrabony lesions. Both have been used in conjunction with other regenerative materials. We conducted a Bayesian network meta-analysis of randomized controlled trials on treatment effects of GTR, EMD and their combination therapies. Material and Methods: A systematic literature search was conducted using the Medline, EMBASE, LILACS and CENTRAL databases up to and including June 2011. Treatment outcomes were changes in probing pocket depth (PPD), clinical attachment level (CAL) and infrabony defect depth. Different types of bone grafts were treated as one group and so were barrier membranes. Results: A total of 53 studies were included in this review, and we found small differences between regenerative therapies which were non-significant statistically and clinically. GTR and GTR-related combination therapies achieved greater PPD reduction than EMD and EMD-related combination therapies. Combination therapies achieved slightly greater CAL gain than the use of EMD or GTR alone. GTR with BG achieved greatest defect fill. Conclusion: Combination therapies performed better than single therapies, but the additional benefits were small. Bayesian network meta-analysis is a promising technique to compare multiple treatments. Further analysis of methodological characteristics will be required prior to clinical recommendations.

NATURAL REGENERATION IN ABANDONED FIELDS FOLLOWING INTENSIVE AGRICULTURAL LAND USE IN AN ATLANTIC FOREST ISLAND, BRAZIL

The time required to regrowth a forest in degraded areas depends on how the forest is removed and on the type of land use following removal. Natural regeneration was studied in abandoned old fields after intensive agricultural land use in areas originally covered by Brazilian Atlantic Forests of the Anchieta Island, Brazil in order to understand how plant communities reassemble following human disturbances as well as to determine suitable strategies of forest restoration. The fields were classified into three vegetation types according to the dominant plant species in: 1) Miconia albicans (Sw.) Triana (Melastomataceae) fields, 2) Dicranopteris flexuosa (Schrader) Underw. (Gleicheniaceae) thickets, and 3) Gleichenella pectinata (Willd.) Ching. (Gleicheniaceae) thickets. Both composition and structure of natural regeneration were compared among the three dominant vegetation types by establishing randomly three plots of 1 x 3 m in five sites of the island. A gradient in composition and abundance of species in natural regeneration could be observed along vegetation types from Dicranopteris fern thickets to Miconia fields. The gradient did not accurately follow the pattern of spatial distribution of the three dominant vegetation types in the island regarding their proximity of the remnant forests. A complex association of biotic and abiotic factors seems to be affecting the seedling recruitment and establishment in the study plots. The lowest plant regeneration found in Dicranopteris and Gleichenella thickets suggests that the ferns inhibit the recruitment of woody and herbaceous species. Otherwise, we could not distinguish different patterns of tree regeneration among the three vegetation types. Our results showed that forest recovery following severe anthropogenic disturbances is not direct, predictable or even achievable on its own. Appropriated actions and methods such as fern removal, planting ground covers, and enrichment planting with tree species were suggested in order to restore the natural forest regeneration process in the abandoned old fields.

Natural regeneration in abandoned fields following intensive agricultural land use in an Atlantic Forest Island, Brazil

The time required to regrowth a forest in degraded areas depends on how the forest is removed and on the type of land use following removal. Natural regeneration was studied in abandoned old fields after intensive agricultural land use in areas originally covered by Brazilian Atlantic Forests of the Anchieta Island, Brazil in order to understand how plant communities reassemble following human disturbances as well as to determine suitable strategies of forest restoration. The fields were classified into three vegetation types according to the dominant plant species in: 1) Miconia albicans (Sw.) Triana (Melastomataceae) fields, 2) Dicranopteris flexuosa (Schrader) Underw. (Gleicheniaceae) thickets, and 3) Gleichenella pectinata (Willd.) Ching. (Gleicheniaceae) thickets. Both composition and structure of natural regeneration were compared among the three dominant vegetation types by establishing randomly three plots of 1 x 3 m in five sites of the island. A gradient in composition and abundance of species in natural regeneration could be observed along vegetation types from Dicranopteris fern thickets to Miconia fields. The gradient did not accurately follow the pattern of spatial distribution of the three dominant vegetation types in the island regarding their proximity of the remnant forests. A complex association of biotic and abiotic factors seems to be affecting the seedling recruitment and establishment in the study plots. The lowest plant regeneration found in Dicranopteris and Gleichenella thickets suggests that the ferns inhibit the recruitment of woody and herbaceous species. Otherwise, we could not distinguish different patterns of tree regeneration among the three vegetation types. Our results showed that forest recovery following severe anthropogenic disturbances is not direct, predictable or even achievable on its own. Appropriated actions and methods such as fern removal, planting ground covers, and enrichment planting with tree species were suggested in order to restore the natural forest regeneration process in the abandoned old fields.

In vitro cultivation of canine multipotent mesenchymal stromal cells on collagen membranes treated with hyaluronic acid for cell therapy and tissue regeneration

Support structures for dermal regeneration are composed of biodegradable and bioresorbable polymers, animal skin or tendons, or are bacteria products. The use of such materials is controversial due to their low efficiency. An important area within tissue engineering is the application of multipotent mesenchymal stromal cells (MSCs) to reparative surgery. The combined use of biodegradable membranes with stem cell therapy may lead to promising results for patients undergoing unsuccessful conventional treatments. Thus, the aim of this study was to test the efficacy of using membranes composed of anionic collagen with or without the addition of hyaluronic acid (HA) as a substrate for adhesion and in vitro differentiation of bone marrow-derived canine MSCs. The benefit of basic fibroblast growth factor (bFGF) on the differentiation of cells in culture was also tested. MSCs were collected from dog bone marrow, isolated and grown on collagen scaffolds with or without HA. Cell viability, proliferation rate, and cellular toxicity were analyzed after 7 days. The cultured cells showed uniform growth and morphological characteristics of undifferentiated MSCs, which demonstrated that MSCs successfully adapted to the culture conditions established by collagen scaffolds with or without HA. This demonstrates that such scaffolds are promising for applications to tissue regeneration. bFGF significantly increased the proliferative rate of MSCs by 63% when compared to groups without the addition of the growth factor. However, the addition of bFGF becomes limiting, since it has an inhibitory effect at high concentrations in culture medium.