Marine collagen scaffolds and photobiomodulation on bone healing process in a model of calvaria defects.

INTRODUCTION: Collagen from marine esponges has been used as a promising material for tissue engineering proposals. Similarly, photobiomodulation (PBM) is able of modulating inflammatory processes after an injury, accelerating soft and hard tissue healing and stimulating neoangiogenesis. However, the effects of the associated treatments on bone tissue healing have not been studied yet. In this context, the present study aimed to evaluate the biological temporal modifications (using two experimental periods) of marine sponge collagen or sponging (SPG) based scaffold and PBM on newly formed bone using a calvaria bone defect model. MATERIAL AND METHODS: Wistar rats were distributed into two groups: SPG or SPG/PBM and euthanized into two different experimental periods (15 and 45 days post-surgery). A cranial critical bone defect was used to evaluate the effects of the treatments. Histology, histomorfometry and immunohistological analysis were performed. RESULTS: Histological findings demonstrated that SPG/PBM-treated animals, 45 days post-surgery, demonstrated a higher amount of connective and newly formed bone tissue at the region of the defect compared to CG. Notwithstanding, no difference among groups were observed in the histomorphometry. Interestingly, for both anti-transforming growth factor-beta (TGF-ß) and anti-vascular endothelial growth factor (VEGF) immunostaining, higher values for SPG/PBM, at 45 days post-surgery could be observed. CONCLUSION: It can be concluded that the associated treatment can be considered as a promising therapeutical intervention.

Influence of the incorporation of marine spongin into a Biosilicate®: an in vitro study.

The combination of different biomaterials can be a promising intervention for the composites manufacture, mainly by adding functional and structural characteristics of each material and guarantee the advantages of the use of these composites. In this context, the aim of this study was to develop and evaluated the influence of the incorporation of marine spongin (SPG) into Biosilicate® (BS) in different proportions be used during bone repair. For this purpose, it was to develop and investigate different BS/SPG formulations for physico-chemical and morphological characteristics by pH, loss mass, Fourier transform infrared spectrometer (FTIR) and scanning electron microscope (SEM) analysis. Additionally, the influence of these composites on cell viability, proliferation, and alkaline phosphatase (ALP) activity were investigated. The results revealed that the pH values of all BS groups (with or without SPG) increased over time. A significant mass loss was observed in all composites, mainly with higher SPG percentages. Additionaly, SEM micrographies demonstrated fibers of SPG into BS and material degradation over time. Moreover, FTIR spectral analysis revealed characteristic peaks of PMMA, BS, and SPG in BS/SPG composites. BS/SPG groups demonstrated a positive effect for fibroblast proliferation after 3 and 7 days of culture. Additionally, BS and BS/SPG formulations (at 10% and 20% of SPG) presented similar values of osteoblasts viability and proliferation after 7 days of culture. Furthermore, ALP activity demonstrated no significant difference between BS and BS/SPG scaffolds, at any composition. Based on the present in vitro results, it can be concluded that the incorporation of SPG into BS was possible and produced an improvement in the physical-chemical characteristics and in the biological performance of the graft especially the formulation with 80/20 and 90/10. Future research should focus on in vivo evaluations of this novel composite.

Incorporation of Collagen from Marine Sponges (Spongin) into Hydroxyapatite Samples: Characterization and In Vitro Biological Evaluation.

Biomaterial-based bone grafts have an important role in the field of bone tissue engineering. One of the most promising classes of biomaterials is collagen, including the ones from marine biodiversity (in general, called spongin (SPG)). Also, hydroxyapatite (HA) has an important role in stimulating bone metabolism. Therefore, this work investigated the association of HA and SPG composites in order to evaluate their physico-chemical and morphological characteristics and their in vitro biological performance. For this, pre-set composite disks were evaluated by means of mass loss after incubation, pH, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and "in vitro" cell viability. pH measurements showed no statistical difference between groups. Moreover, a higher mass loss was observed for HA/SPG70/30 compared to the other groups for all experimental periods. Moreover, SEM representative micrographs showed the degradation of the samples with and without immersion. FTIR analysis demonstrated the absorption peaks for poly(methyl methacrylate) (PMMA), HA, and SPG. A higher L292 cell viability for control and PMMA was observed compared to HA and HA/SPG 90/10. Also, HA/SPG 70/30 showed higher cell viability compared to HA and HA/SPG 90/10 on days 3 and 7 days of culture. Furthermore, HA showed a significant lower MC3T3 cell viability compared to control and HA/SPG 70/30 on day 3 and no significant difference was observed between the composites in the last experimental period. Based on our investigations, it can be concluded that the mentioned composites were successfully obtained, presenting improved biological properties, especially the one mimicking the composition of bone (with 70% of HA and 30% of SPG). Consequently, these data highlight the potential of the introduction of SPG into HA to improve the performance of the graft for bone regeneration applications. Further long-term studies should be carried out to provide additional information concerning the late stages of material degradation and bone healing in the presence of HA/SPG.

Characterization and Cytotoxicity Evaluation of a Marine Sponge Biosilica.

Bone fractures characterize an important event in the medical healthcare, being related to traumas, aging, and diseases. In critical conditions, such as extensive bone loss and osteoporosis, the tissue restoration may be compromised and culminate in a non-union consolidation. In this context, the osteogenic properties of biomaterials with a natural origin have gained prominence. Particularly, marine sponges are promising organisms that can be exploited as biomaterials for bone grafts. Thus, the objectives of this study were to study the physicochemical and morphological properties of biosilica (BS) from sponges by using scanning electron microscopy, Fourier-transform infrared, X-ray diffraction (SEM, FTIR and XRD respectively), mineralization, and pH. In addition, tests on an osteoblast precursor cell line (MC3T3-E1) were performed to investigate its cytotoxicity and proliferation in presence of BS. Bioglass (BG) was used as gold standard material for comparison purposes. Sponge BS was obtained, and this fact was proven by SEM, FTIR, and XRD analysis. Calcium assay showed a progressive release of this ion from day 7 and a more balanced pH for BS was maintained compared to BG. Cytotoxicity assay indicated that BS had a positive influence on MC3T3-E1 cells viability and qRT-PCR showed that this material stimulated Runx2 and BMP4 gene expressions. Taken together, the results indicate a potential use of sponge biosilica for tissue engineering applications.

Comparison of two different laser photobiomodulation protocols on the viability of random skin flap in rats.

To identify the best low level laser photobiomodulation application site at the same irradiation time to increase the viability of the skin flap in rats. Eighteen male rats (Rattus norvegicus: var. Albinus, Rodentia Mammalia) were randomly distributed into three groups (n = 6). Group I (GI) was submitted to simulated laser photobiomodulation; group II (GII) was submitted to laser photobiomodulation at three points in the flap cranial base, and group III (GIII) was submitted to laser photobiomodulation at 12 points distributed along the flap. All groups were irradiated with an Indium, Galium, Aluminum, and Phosphorus diode laser (InGaAlP), 660 nm, with 50 mW power, irradiated for a total time of 240 s in continuous emission mode. The treatment started immediately after performing the cranial base random skin flap (10 × 4 cm2 dimension) and reapplied every 24 h, with a total of five applications. The animals were euthanized after the evaluation of the percentage of necrosis area, and the material was collected for histological analysis on the seventh postoperative day. GII animals presented a statistically significant decrease for the necrosis area when compared to the other groups, and a statistically significant increase in the quantification of collagen when compared to the control. We did not observe a statistical difference between the TGFß and FGF expression in the different groups evaluated. The application of laser photobiomodulation at three points of the flap cranial base was more effective than at 12 points regarding the reduction of necrosis area.

Biosilicate/PLGA osteogenic effects modulated by laser therapy: In vitro and in vivo studies.

The main purpose of the present work was to evaluate if low laser level therapy (LLLT) can improve the effects of Biosilicate®/PLGA (BS/PLGA) composites on cell viability and bone consolidation using a tibial defects of rats. The composites were characterized by scanning electron microscope (SEM) and reflection Fourier transform infrared spectrometer (FTIR). For the in vitro study, fibroblast and osteoblast cells were seeded in the extract of the composites irradiated or not with LLLT (Ga-Al-As, 808nm, 10J/cm2) to assess cell viability after 24, 48 and 72h. For the in vivo study, 80 Wistar rats with tibial bone defects were distributed into 4 groups (BS; BS+LLLT; BS/PLGA and BS/PLGA+LLLT) and euthanized after 2 and 6weeks. Laser irradiation Ga-Al-As (808nm, 30J/cm2) in the rats was performed 3 times a week. The SEM and FTIR results revealed that PLGA were successfully inserted into BS and the microparticles degraded over time. The in vitro findings demonstrated higher fibroblast viability in both BS/PLGA groups after 24h and higher osteoblast viability in BS/PLGA+LLLT in all periods. As a conclusion, animals treated with BS/PLGA+LLLT demonstrated an improved material degradation and an increased amount of granulation tissue and newly formed bone.

Characterization and biological evaluation of the introduction of PLGA into biosilicate®.

The aims of this study were to characterize different BS/PLGA composites for their physicochemical and morphological characteristics and evaluate the in vitro and in vivo biological performance. The physicochemical and morphological modifications were analyzed by pH, mass loss, XRD, setting time, and SEM. For in vitro analysis, the osteoblast and fibroblast viability was evaluated. For in vivo evaluations, histopathology and immunohistochemistry were performed in a tibial defect in rats. After incubation, all composites presented lower values in pH and mass loss over time. Moreover, XRD and SEM analysis confirmed that the composites degraded over time. Additionally, pore formation was observed by SEM analysis after incubation mainly in BS/PLGA groups. BS/PLGA showed significantly increased in osteoblast viability 24 h. Moreover, BS/PLGA composites demonstrated an increase in fibroblast viability in all periods analyzed when compared to BS. In the in vivo study, after 2 and 6 weeks of implantation of biomaterials, histopathological findings revealed that the BS/PLGA composites degrades over time, mainly at periphery. Moreover, can be observed the presence of granulation tissue, bone formation, Runx-2, and RANKL immunoexpression in all groups. In conclusion, BS/PLGA composites present appropriate physicochemical characteristics, stimulate the cellular viability, and enhance the bone repair in vivo. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1063-1074, 2017.

Characterization and biocompatibility of a fibrous glassy scaffold.

Bioactive glasses (BGs) are known for their ability to bond to living bone and cartilage. In general, they are readily available in powder and monolithic forms, which are not ideal for the optimal filling of bone defects with irregular shapes. In this context, the development of BG-based scaffolds containing flexible fibres is a relevant approach to improve the performance of BGs. This study is aimed at characterizing a new, highly porous, fibrous glassy scaffold and evaluating its in vitro and in vivo biocompatibility. The developed scaffolds were characterized in terms of porosity, mineralization and morphological features. Additionally, fibroblast and osteoblast cells were seeded in contact with extracts of the scaffolds to assess cell proliferation and genotoxicity after 24, 72 and 144 h. Finally, scaffolds were placed subcutaneously in rats for 15, 30 and 60 days. The scaffolds presented interconnected porous structures, and the precursor bioglass could mineralize a hydroxyapatite (HCA) layer in simulated body fluid (SBF) after only 12 h. The biomaterial elicited increased fibroblast and osteoblast cell proliferation, and no DNA damage was observed. The in vivo experiment showed degradation of the biomaterial over time, with soft tissue ingrowth into the degraded area and the presence of multinucleated giant cells around the implant. At day 60, the scaffolds were almost completely degraded and an organized granulation tissue filled the area. The results highlight the potential of this fibrous, glassy material for bone regeneration, due to its bioactive properties, non-cytotoxicity and biocompatibility. Future investigations should focus on translating these findings to orthotopic applications. Copyright © 2015 John Wiley & Sons, Ltd.

Aerobic exercise training and low-level laser therapy modulate inflammatory response and degenerative process in an experimental model of knee osteoarthritis in rats.

OBJECTIVE: The aim of this study was to evaluate the effects of an aerobic exercise training and low-level laser therapy (LLLT) (associated or not) on degenerative modifications and inflammatory mediators on the articular cartilage using an experimental model of knee OA. MATERIAL AND METHODS: Fifty male Wistar rats were randomly divided into five groups: control group (CG); knee OA control group (OAC); OA plus exercise training group (OAT); OA plus LLLT group (OAL); OA plus exercise training associated with LLLT group (OATL). The exercise training (treadmill; 16 m/min; 50 min/day) and the laser irradiation (two points-medial and lateral side of the left joint; 24 sessions) started 4 weeks after the surgery, 3 days/week for 8 weeks. RESULTS: The results showed that all treated groups showed (irradiated or not) a better pattern of tissue organization, with less fibrillation and irregularities along the articular surface and chondrocytes organization, a lower degenerative process measured by OARSI score and higher thickness values. Additionally, all treated group showed a reduced expression in IL-1ß, caspase-3 and MMP-13 compared to OAC. Moreover, a lower caspase-3 expression was observed in OATL compared to OAL and OAT. CONCLUSION: These results suggest that exercise training and LLLT were effective in preventing cartilage degeneration and modulating inflammatory process induced by knee OA.

Effects of photobiomodulation on the fatigue level in elderly women: an isokinetic dynamometry evaluation.

Aging is responsible by a series of morphological and functional modifications that lead to a decline of muscle function, particularly in females. Muscle tissue in elderly people is more susceptible to fatigue and, consequently, to an increased inability to maintain strength and motor control. In this context, therapeutic approaches able of attenuating muscle fatigue have been investigated. Among these, the photobiomodulation demonstrate positive results to interacts with biological tissues, promoting the increase in cell energy production. Thus, the aim of this study was to investigate the effects of photobiomodulation (808 nm, 250 J/cm(2), 100 mW, 7 J each point) in the fatigue level and muscle performance in elderly women. Thirty subjects entered a crossover randomized double-blinded placebo-controlled trial. Photobiomodulation was delivered on the rectus femoris muscle of the dominant limb immediately before the fatigue protocol. In both sessions, peripheral muscle fatigue was analyzed by surface electromyography (EMG) and blood lactate analysis. Muscle performance was evaluated using an isokinetic dynamometer. The results showed that photobiomodulation was able of reducing muscle fatigue by a significant increase of electromyographic fatigue index (EFI) (p = 0.047) and decreasing significantly lactate concentration 6 min after the performance of the fatigue protocol (p = 0. 0006) compared the placebo laser session. However, the photobiomodulation was not able of increasing muscle performance measured by the isokinetic dynamometer. Thus, it can be conclude that the photobiomodulation was effective in reducing fatigue levels. However, no effects of photobiomodulation on muscle performance was observed.

Effect of a new bioactive fibrous glassy scaffold on bone repair.

Researchers have investigated several therapeutic approaches to treat non-union fractures. Among these, bioactive glasses and glass ceramics have been widely used as grafts. This class of biomaterial has the ability to integrate with living bone. Nevertheless, bioglass and bioactive materials have been used mainly as powder and blocks, compromising the filling of irregular bone defects. Considering this matter, our research group has developed a new bioactive glass composition that can originate malleable fibers, which can offer a more suitable material to be used as bone graft substitutes. Thus, the aim of this study was to assess the morphological structure (via scanning electron microscope) of these fibers upon incubation in phosphate buffered saline (PBS) after 1, 7 and 14 days and, also, evaluate the in vivo tissue response to the new biomaterial using implantation in rat tibial defects. The histopathological, immunohistochemistry and biomechanical analyzes after 15, 30 and 60 days of implantation were performed to investigate the effects of the material on bone repair. The PBS incubation indicated that the fibers of the glassy scaffold degraded over time. The histological analysis revealed a progressive degradation of the material with increasing implantation time and also its substitution by granulation tissue and woven bone. Histomorphometry showed a higher amount of newly formed bone area in the control group (CG) compared to the biomaterial group (BG) 15 days post-surgery. After 30 and 60 days, CG and BG showed a similar amount of newly formed bone. The novel biomaterial enhanced the expression of RUNX-2 and RANK-L, and also improved the mechanical properties of the tibial callus at day 15 after surgery. These results indicated a promising use of the new biomaterial for bone engineering. However, further long-term studies should be carried out to provide additional information concerning the material degradation in the later stages and the bone regeneration induced by the fibrous material.

Incidence and clinical significance of iliac vein compression.

OBJECTIVES: To determine the frequency of left common iliac vein (CIV) compression by the right common iliac artery (CIA) based on CT scan images. METHODS: CT scan images were reviewed and the diameter of CIV was measured at the area of minimal diameter and compared to the distal adjacent segment and the contralateral CIV at the same level. Medical records were reviewed for symptoms, deep vein thrombosis (DVT) and risk factors that might be associated with DVT. Data were analyzed with SPSS program using both Chi square and t test. A p < 0.05 was considered statistically significant. Linear regression (R2) was used to evaluate correlation. RESULTS: A total of 300 complete records were reviewed. The mean age was 51.89 years, with 126 (42%) males. Comparison between the two groups (>70% vs <70%) showed similar clinical factors such as history of DVT, surgery, immobilization, malignancy, limb trauma, pregnancy, obesity, CHF, and smoking. There were more females with CIV compression of 70% or more than males (19.5% vs 11.1% P < .049). CONCLUSION: Diameter stenosis more than 70% was present in 30.6% of cases with higher incidence in females. The presence of stenosis was not associated with the presence of clinical symptoms.

Nandrolone decanoate is able to modulate proliferation and adhesion of myoblasts.

The search for a more efficient repair process of muscle injuries has become evident in clinical practice. The aim of the present study was to evaluate the effect of nandrolone decanoate (ND) on the proliferation, adhesion, and expression of myogenic regulatory factors (MRFs) in C2C12 cells.Methods. Cell proliferation and adhesion were assessed using an MTT assay. The expression of MRFs was assessed by real-time PCR.Results. ND applied at 10 or 25 µM concentration induced after 60 min an increase in adhesion, at 5 µM concentration induced after 5 days an increase in cell proliferation, and ND at 50 µM concentration led after 5 days to a decrease in cell proliferation in comparison with other groups. The steroid did not alter the expression of MRFs.Conclusions. The positive effects of ND regarding the proliferation and adhesion of C2C12 cells suggest that this steroid may have positive effects following a muscle injury.

Stent fracture in the brachiocephalic trunk.

Stents are commonly used as a tool for revascularization of different vascular beds in the body. However, many pitfalls have been reported with their use, such as thrombosis, migration, restenosis or fractures. The latter have been strongly correlated to in-stent restenosis with long-term follow-up. We report a rare case of an early stent fracture in the brachiocephalic trunk with in-stent restenosis and recurrence of symptoms. To our knowledge there has been only one case report of a delayed brachiocephalic stent fracture in the English literature. We believe that our case is the first report of an early stent fracture in the brachiocephalic trunk.

Incorporation of bioactive glass in calcium phosphate cement: material characterization and in vitro degradation.

Calcium phosphate cements (CPCs) have been widely used as an alternative to biological grafts due to their excellent osteoconductive properties. Although degradation has been improved by using poly(D,L-lactic-co-glycolic) acid (PLGA) microspheres as porogens, the biological performance of CPC/PLGA composites is insufficient to stimulate bone healing in large bone defects. In this context, the aim of this study was to investigate the effect of incorporating osteopromotive bioactive glass (BG; up to 50 wt %) on setting properties, in vitro degradation behavior and morphological characteristics of CPC/BG and CPC/PLGA/BG. The results revealed that the initial and final setting time of the composites increased with increasing amounts of incorporated BG. The degradation test showed a BG-dependent increasing effect on pH of CPC/BG and CPC/PLGA/BG pre-set scaffolds immersed in PBS compared to CPC and CPC/PLGA equivalents. Whereas no effects on mass loss were observed for CPC and CPC/BG pre-set scaffolds, CPC/PLGA/BG pre-set scaffolds showed an accelerated mass loss compared with CPC/PLGA equivalents. Morphologically, no changes were observed for CPC and CPC/BG pre-set scaffolds. In contrast, CPC/PLGA and CPC/PLGA/BG showed apparent degradation of PLGA microspheres and faster loss of integrity for CPC/PLGA/BG pre-set scaffolds compared with CPC/PLGA equivalents. Based on the present in vitro results, it can be concluded that BG can be successfully introduced into CPC and CPC/PLGA without exceeding the setting time beyond clinically acceptable values. All injectable composites containing BG had suitable handling properties and specifically CPC/PLGA/BG showed an increased rate of mass loss. Future investigations should focus on translating these findings to in vivo applications.

Incorporation of bioactive glass in calcium phosphate cement: An evaluation.

Bioactive glasses (BGs) are known for their unique ability to bond to living bone. Consequently, the incorporation of BGs into calcium phosphate cement (CPC) was hypothesized to be a feasible approach to improve the biological performance of CPC. Previously, it has been demonstrated that BGs can successfully be introduced into CPC, with or without poly(d,l-lactic-co-glycolic) acid (PLGA) microparticles. Although an in vitro physicochemical study on the introduction of BG into CPC was encouraging, the biocompatibility and in vivo bone response to these formulations are still unknown. Therefore, the present study aimed to evaluate the in vivo performance of BG supplemented CPC, either pure or supplemented with PLGA microparticles, via both ectopic and orthotopic implantation models in rats. Pre-set scaffolds in four different formulations (1: CPC; 2: CPC/BG; 3: CPC/PLGA; and 4: CPC/PLGA/BG) were implanted subcutaneously and into femoral condyle defects of rats for 2 and 6 weeks. Upon ectopic implantation, incorporation of BG into CPC improved the soft tissue response by improving capsule and interface quality. Additionally, the incorporation of BG into CPC and CPC/PLGA showed 1.8- and 4.7-fold higher degradation and 2.2- and 1.3-fold higher bone formation in a femoral condyle defect in rats compared to pure CPC and CPC/PLGA, respectively. Consequently, these results highlight the potential of BG to be used as an additive to CPC to improve the biological performance for bone regeneration applications. Nevertheless, further confirmation is necessary regarding long-term in vivo studies, which also have to be performed under compromised wound-healing conditions.

Effect of three exercise programs on patients with chronic obstructive pulmonary disease.

We compared the effect of three different exercise programs on patients with chronic obstructive pulmonary disease including strength training at 50_80% of one-repetition maximum (1-RM) (ST; N = 11), low-intensity general training (LGT; N = 13), or combined training groups (CT; N = 11). Body composition, muscle strength, treadmill endurance test (TEnd), 6-min walk test (6MWT), Saint George's Respiratory Questionnaire (SGRQ), and baseline dyspnea (BDI) were assessed prior to and after the training programs (12 weeks). The training modalities showed similar improvements (P > 0.05) in SGRQ-total (ST = 13 +/- 14%; CT = 12 +/- 14%; LGT = 11 +/- 10%), BDI (ST = 1.8 +/- 4; CT = 1.8 +/- 3; LGT = 1 +/- 2), 6MWT (ST = 43 +/- 51 m; CT = 48 +/- 50 m; LGT = 31 +/- 75 m), and TEnd (ST = 11 +/- 20 min; CT = 11 +/- 11 min; LGT = 7 +/- 5 min). In the ST and CT groups, an additional improvement in 1-RM values was shown (P < 0.05) compared to the LGT group (ST = 10 +/- 6 to 57 +/- 36 kg; CT = 6 +/- 2 to 38 +/- 16 kg; LGT = 1 +/- 2 to 16 +/- 12 kg). The addition of strength training to our current training program increased muscle strength; however, it produced no additional improvement in walking endurance, dyspnea or quality of life. A simple combined training program provides benefits without increasing the duration of the training sessions.

Effect of three exercise programs on patients with chronic obstructive pulmonary disease

We compared the effect of three different exercise programs on patients with chronic obstructive pulmonary disease including strength training at 50_80 percent of one-repetition maximum (1-RM) (ST; N = 11), low-intensity general training (LGT; N = 13), or combined training groups (CT; N = 11). Body composition, muscle strength, treadmill endurance test (TEnd), 6-min walk test (6MWT), Saint George's Respiratory Questionnaire (SGRQ), and baseline dyspnea (BDI) were assessed prior to and after the training programs (12 weeks). The training modalities showed similar improvements (P > 0.05) in SGRQ-total (ST = 13 ± 14 percent; CT = 12 ± 14 percent; LGT = 11 ± 10 percent), BDI (ST = 1.8 ± 4; CT = 1.8 ± 3; LGT = 1 ± 2), 6MWT (ST = 43 ± 51 m; CT = 48 ± 50 m; LGT = 31 ± 75 m), and TEnd (ST = 11 ± 20 min; CT = 11 ± 11 min; LGT = 7 ± 5 min). In the ST and CT groups, an additional improvement in 1-RM values was shown (P < 0.05) compared to the LGT group (ST = 10 ± 6 to 57 ± 36 kg; CT = 6 ± 2 to 38 ± 16 kg; LGT = 1 ± 2 to 16 ± 12 kg). The addition of strength training to our current training program increased muscle strength; however, it produced no additional improvement in walking endurance, dyspnea or quality of life. A simple combined training program provides benefits without increasing the duration of the training sessions.

Pulmonary function testing in quadriplegic subjects.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: Pulmonary functional capacity in 23 Brazilian quadriplegic subjects (ASIA A), aged 30 (9.5) years, weight 66 (10.75) kg, height 176 (7) cm, was investigated at 42 (64) months postinjury. SETTING: University Hospital--UNICAMP, Campinas, Brazil. METHOD: Subjects performed forced vital capacity (FVC) and maximal voluntary ventilation (MVV) tests while seated in their standard wheelchairs. Forced Expired Volume after 1 s (FEV1) and FVC/FEV1 ratio were calculated from these tests. Values obtained were compared to three prediction equations from the literature that are used specifically for spinal cord subjects and include different variables in their formulae, such as age, gender, height, postinjury time and injury level. Data are expressed as median (interquartile interval). Differences between values were demonstrated by median confidence interval with significance level set at alpha=0.05. RESULTS: Obtained data were statistically different from prediction equation results, with FVC 3.11 (0.81), 4.46 (0.28), 4.16 (0.33), 4.26 (0.42); FEV1 2.77 (1.03), 3.67 (0.21), 3.66 (0.30), 3.45 (0.39) and MVV 92 (27), 154.2 (11.9), 156.6 (14), 157.3 (16.8), where the first value is obtained experimentally and the second, third and fourth values correspond to predicted values. The results obtained from spirometry test in this study differed significantly from the results obtained when prediction equations were used. CONCLUSION: The use of prediction equations developed to estimate pulmonary function in wheelchair users significantly overestimates pulmonary function of quadriplegic individuals with complete lesions (ASIA group A), in comparison to measured values.

The effects of laser irradiation on osteoblast and osteosarcoma cell proliferation and differentiation in vitro.

OBJECTIVE: The aim of this study was to investigate the effects of 670-nm, 780-nm, and 830-nm laser irradiation on cell proliferation of normal primary osteoblast (MC3T3) and malignant osteosarcoma (MG63) cell lines in vitro. BACKGROUND: Some studies have shown that laser phototherapy is able to stimulate the osteogenesis of bone tissue, increasing osteoblast proliferation and accelerating fracture consolidation. It has been suggested that laser light may have a biostimulatory effect on tumor cells. However, the mechanism by which the laser acts on cells is not fully understood. MATERIALS AND METHODS: Neonatal, murine, calvarial, osteoblastic, and human osteosarcoma cell lines were studied. A single laser irradiation was performed at three different wavelengths, at the energies of 0.5, 1, 5, and 10 J/cm(2). Twenty-four hours after laser irradiation, cell proliferation and alkaline phosphatase assays were assessed. RESULTS: Osteoblast proliferation increased significantly after 830-nm laser irradiation (at 10 J/cm(2)) but decreased after 780-nm laser irradiation (at 1, 5, and 10 J/cm(2)). Osteosarcoma cell proliferation increased significantly after 670-nm (at 5 J/cm(2)) and 780-nm laser irradiation (at 1, 5, and 10 J/cm(2)), but not after 830-nm laser irradiation. Alkaline phosphatase (ALP) activity in the osteoblast line was increased after 830-nm laser irradiation at 10 J/cm(2), whereas ALP activity in the osteosarcoma line was not altered, regardless of laser wavelength or intensity. CONCLUSION: Based on the conditions of this study, we conclude that each cell line responds differently to specific wavelength and dose combinations. Further investigations are required to investigate the physiological mechanisms responsible for the contrasting outcomes obtained when using laser irradiation on cultured normal and malignant bone cells.