Percentage Of Connective Tissue Research Articles

Aquatic Pollution and Risks to Biodiversity: The Example of Cocaine Effects on the Ovaries of Anguilla anguilla.

Simple SummaryThe increasing consumption of illicit drugs by man has determined the presence of these drugs in waters, both fresh and marine, in almost all the world. Many studies have shown the dangerousness of these substances to aquatic organisms, so the goal of this study was to investigate the effects of cocaine, one of the most used drugs, on the ovaries of the Anguilla anguilla eel, a critically endangered edible fish, to understand if this drug could also compromise fish reproduction. Our results show that cocaine may impair reproduction in eels through changes in oocyte morphology, expressions of enzymes crucial for oogenesis, and alteration in the serum levels of cortisol and gonadotropins, which regulate the development and maturation of eel gonads. Though this study was conducted on eels, other species may also suffer similar effects from cocaine exposure; our results, therefore, show that illicit drug use is a serious problem not only for humans but also for the environment.Pollution is one of the main causes of the loss of biodiversity, currently one of the most important environmental problems. Important sources of aquatic pollution are illicit drugs, whose presence in waters is closely related to human consumption; their psychoactive properties and biological activity suggest potential adverse effects on non-target organisms, such as aquatic biota. In this study, we evaluated the effect of an environmentally relevant concentration of cocaine (20 ng L−1), an illicit drug widely found in surface waters, on the ovaries of Anguilla anguilla, a species critically endangered and able to accumulate cocaine in its tissues following chronic exposure. The following parameters were evaluated: (1) the morphology of the ovaries; (2) the presence and distribution of enzymes involved in oogenesis; (3) serum cortisol, FSH, and LH levels. The eels exposed to cocaine showed a smaller follicular area and a higher percentage of connective tissue than controls (p < 0.05), as well as many previtellogenic oocytes compared with controls having numerous fully vitellogenic and early vitellogenic oocytes. In addition, the presence and location of 3β-hydroxysteroid dehydrogenase, 17β-hydroxysteroid dehydrogenase, and P450 aromatase differed in the two groups. Finally, cocaine exposure decreased FSH and LH levels, while it increased cortisol levels. These findings show that even a low environmental concentration of cocaine affects the ovarian morphology and activity of A. anguilla, suggesting a potential impact on reproduction in this species.

Metformin-Incorporated Gelatin/Nano-Hydroxyapatite Scaffolds Promotes Bone Regeneration in Critical Size Rat Alveolar Bone Defect Model.

In this study, we fabricated gelatin/nano-hydroxyapatite/metformin scaffold (GHMS) and compared its effectiveness in bone regeneration with extraction-only, Sinbone, and Bio-Oss Collagen® groups in a critical size rat alveolar bone defect model. GHMS was synthesized by co-precipitating calcium hydroxide and orthophosphoric acid within gelatin solution, incorporating metformin, and cross-linked by microbial transglutaminase. The morphology, characterization, and biocompatibility of scaffold were examined. The in vitro effects of GHMS on osteogenic gene and protein expressions were evaluated. In vivo bone formation was assessed in a critical size rat alveolar bone defect model with micro-computed tomography and histological examination by comparing GHMS with extraction-only, Sinbone, and Bio-Oss Collagen®. The synthesized GHMS had a highly interconnected porous structure with a mean pore size of 81.85 ± 13.8 µm. GHMS exhibited good biocompatibility; promoted ALPL, RUNX2, SP7, BGLAP, SPARC and Col1a1 gene expressions; and upregulated the synthesis of osteogenic proteins, including osteonectin, osteocalcin, and collagen type I. In critical size rat alveolar bone defects, GHMS showed superior bone regeneration compared to extraction-only, Sinbone, and Bio-Oss Collagen® groups as manifested by greater alveolar ridge preservation, while more bone formation with a lower percentage of connective tissue and residual scaffold at the defect sites grafted with GHMS in histological staining. The GHMS presented in this study may be used as a potential bone substitute to regenerate alveolar bone. The good biocompatibility, relatively fast degradation, interconnected pores allowing vascularization, and higher bioactivity properties of the components of the GHMS (gelatin, nHA, and metformin) may contribute to direct osteogenesis.

Botulinum toxin A improves neurogenic bladder fibrosis by suppressing transforming growth factor β1 expression in rats.

BackgroundIntradetrusor botulinum toxin A injection is recommended for the treatment of refractory detrusor overactivity (DO) in patients with neurogenic bladder, however, whether it could inhibit neurogenic bladder fibrosis is uncertain. This study aimed to investigate the effect of botulinum toxin A on neurogenic bladder fibrosis and the underlying mechanism.MethodsForty eight Female Wistar rats were evenly randomized into 4 groups: Sham, T10 transection, Early and Late groups. The last three groups were subjected to T10 spinal cord transection, while the Sham group was treated with sham surgery. 0.9% saline was injected into the detrusor in the Sham and T10 transection groups simultaneously with the surgery, while 2 U/rat botulinum toxin A was injected into the detrusor simultaneously with the surgery in the Early group and 4 weeks following the surgery in the Late group. Body/bladder weight, cystometric parameters, bladder Hematoxylin-eosin staining were used to evaluate the bladder fibrosis. Western blot and quantitative Real-time PCR were used to evaluate the expression of bladder transforming growth factor β1.ResultsCompared with the T10 transection group, the bladder/body weight was decreased significantly in the Early and Late groups (P<0.05), along with the significant inhibition of non-voiding contraction (NVC) frequency and amplitude (P<0.05), and the significant increase of bladder volume (P<0.05). The detrusor connective tissue percentage (P<0.05) and the expression of transforming growth factor β1 (P<0.05) also decreased significantly in the Early and Late groups. Those changes were more obviously in the Early group than in the Late group.ConclusionsIntradetrusor botulinum toxin A injection reduced bladder fibrosis in rats with spinal cord injury (SCI), which was more obviously in the Early group than in the Late group. The mechanisms might be mediated by suppression of transforming growth factor β1 (TGF-β1) expression.

Differences in the response in the dermis of the tails of young and old SD rats to treatment with bipolar RF.

The passing of the years is marked by intrinsic (chronological) and extrinsic aging, caused by photoaging, which is characterized by a decrease in collagen and the deposition of abnormal elastic fibers in the dermis. The use of bipolar radiofrequency (RF) increases fibroblast proliferation and differentiation, accompanied by collagen synthesis and a subsequent increase in connective tissue, and it is not known whether the biological effects of this type of radiofrequency on the dermis are similar regardless of the age of the individual or whether such effects are altered by the aging process itself. The objective was to perform a histological study of the changes in the tail dermis of young and old rats after submitting them to bipolar RF, to determine cell proliferation and volume of connective tissue. One part of the rat tail was fixed in formol and processed for light microscopy and another part processed for electron microscopy. The number of fibroblasts/unit area and cells positive to nuclear proliferation antigen was higher in young animals. Significant differences were observed regarding expression of HSP-47 protein, and the value was always lower in old rats. No significant differences were observed in the percentage of connective tissue. No histological alterations were observed in any rats. Treatment with RF increased the number of fibroblasts located in the connective tissue of the young rats. In addition, the effect of a single treatment on the population of fibroblasts in young animals was sufficient to activate the synthesis of new collagen.

Short-term effects of whole-body vibration on the soleus of ooforectomized rats: Histomorphometric analysis and oxidative stress in an animal model

PurposeThe aim of this study was to analyze the effects of mechanical vibration on the histomorphometry and oxidative stress of oophorectomized rats. MethodSeventy-two Wistar rats were randomized to Pseudoophorectomy (P) and Oophorectomy (O) and subdivided into untreated animals and euthanized after four (P4 and O4) and eight (P8 and O8) weeks and animals treated during four (PT4 and OT4) and eight (PT8 and OT8) weeks. The treatment consisted of use of whole-body vibration for 10 min, three times a week. After euthanasia, the soleus muscle was collected. The general morphological analysis was performed in the right soleus muscle and then the cross-sectional area, the largest and the smallest diameter of the muscle fiber in 100 fibers per muscle, also the nuclei and capillary/fiber ratios, and percentage of connective tissue were measured. The left soleous was used for oxidative stress analysis. ResultsPT4 presented higher values in cross-sectional area than P4 and PT8, while O8 was lower than O4, P8 and OT8; for the fiber diameters, the oophorectomized animals had lower values than the pseudo-oophorectomized animals and the treatments values higher than the ones that had no treatment. In oxidative stress, O8 and OT8 presented higher lipoperoxidation, without any alterations to the activities of superoxide dismutase, catalase and cholinesterase. ConclusionWhole-body vibration induced muscle hypertrophy in the pseudo-oophorectomized rats after four weeks, as well as being able to reverse the changes caused by the surgery in eight weeks in that variable.

Histological comparison of DBBM and platelet rich fibrin for guided bone regeneration in a rabbit model

To histologically evaluate the use of bovine derived deproteinized xenograft (DBBM), leukocyte and platelet rich fibrin (L-PRF) and the combination of both in Guided Bone Regeneration (GBR) performed in non-critical size defects in rabbit. A prospective experimental study was performed. Four bone defects in the tibiae of 12 rabbits were made and each of them was filled with DBBM, L-PRF, a combination of DBBM+L-PRF or was left to heal as control site. All defects were covered with a collagen membrane. Rabbits were randomly distributed in three groups and euthanatized at 3, 6 or 9 weeks. Samples were obtained and histologically analyzed to determine vital bone, connective tissue and remaining graft particles percentage. Analysis of variance, Kruskal Wallis and non-paired t-test where used to evaluate the significance of the results. At 3 weeks of healing, DBBM showed significantly more vital bone percentage than L-PRF (p=0,05) and DBBM+L-PRF showed significantly less connective tissue than control (p<0,05). All other groups showed no statistical difference between them. At 6 weeks of healing, DBBM showed significantly more vital bone percentage than L-PRF (p<0,05), DBBM+L-PRF (p<0,05) and control (p<0,05) and there wasn't any other significant difference regarding to connective tissue or remaining particle percentage between groups. At t 9 weeks healing period, there weren't any significant differences between groups. DBBM seems to enhance vital bone formation at early healing stages. The use of L-PRF alone or combined with DBBM, didn't show any histological improvement regarding to vital bone formation. The use of DBBM, alone or in conjunction with L-PRF showed a trend to reduce connective tissue percentage. The use of L-PRF combined with DBBM didn't affect the remaining particle percentage.

Histological analysis of socket preservation using DBBM. A systematic review and meta-analysis

PurposeDeproteinized bovine bone mineral (DBBM) is a type of bone substitute material widely used in tooth extraction sites. However, there is a lack of evidence supporting the benefit of DBBM used for postextraction socket preservation with regard to new bone formation. This meta-analysis and systematic review was conducted to explore whether site preservation (SP) using DBBM could provide benefits with regard to new bone formation compared with natural healing. Materials and methodsStudies reporting histological results for postextraction SP with DBBM and natural healing from 2000 to 2019 were identified in three databases, and a meta-analysis was conducted. ResultsFive studies were included. The DBBM group had a significantly lower new bone percentage than the natural healing group, with a MD of −24.75 [95%CI: −39.77, −9.73] (P=0.001). The percentage of connective tissue in the extraction site was not significantly different between the two groups, with a MD of 0.60 [95%CI: −4.85, 6.05] (P=0.83). ConclusionsSP using DBBM provided no additional benefit with regard to postextraction new bone formation in comparison with natural healing. Due to the lack of high-quality research, further large-sample studies and standard studies are needed to confirm these conclusions.

Compensatory neuromuscular junction adaptations of forelimb muscles in focal cortical ischemia in rats.

IntroductionUpper limb movements are affected frequently by brain ischemia (BI). Mechanisms involved in recovery and compensatory movements have developed several studies. However, less attention is given to skeletal muscles, where neuromuscular junction (NMJ) has an important role on muscle tropism and functional performance.MethodsAnimals were divided into two groups: control (C) and BI. Then, animals were skilled to perform single‐pellet retrieval task, following these procedures: habituation, shaping, and single‐pellet retrieval task. BI was induced using stereotaxic surgery in order to apply endothelin‐1 in motor cortex, representative of movements of dominant paw. Reaching task performance was evaluated by single‐pellet retrieval task 1 day before BI induction, 4 and 15 days after BI induction. After that, biceps, triceps, fingers flexor, and extensor muscles were extracted. NMJ was assessed in morphometric characteristics (total area, total perimeter, and feret). Muscle fiber cross‐sectional area and connective tissue percentage were also evaluated for characterization. Student's t test was used for comparisons between C and BI groups. Tau Kendall's correlation was applied among variables from BI group.ResultsAn increase in all NMJ morphometric parameters, as well as increase of atrophy and fibrosis in BI group compared with C. There was a high level of direct correlation between mean values of NMJ morphometry with percentage of success in reaching task in BI group.ConclusionBrain ischemia‐induced NMJ compensatory expansion, muscle atrophy, and fibrosis in forelimb muscles that are related to reaching performance.

AÇÃO DA VIBRAÇÃO DE CORPO INTEIRO NA MORFOLOGIA DO MÚSCULO TIBIAL ANTERIOR DE RATAS WISTAR OOFORECTOMIZADAS

Estrogen is essential for maintaining muscle mass and strength and its decrease in menopause leads to sarcopenia. Physical exercises, such as whole-body vibration (WBV), stand out as a treatment promoting improvement in several physiological parameters. However, its tissue effects are still poorly understood, and this study analyzed its action on the tibialis anterior muscle morphology of oophorectomized rats. 32 female Wistar rats were divided into two groups, oophorectomy (GO) and pseudo-oophorectomy (GP). Subsequently, GO and GP were divided into two groups, treated (GOT e GPT) or not (GO e GP) with WBV. The vibrating platform was used as a WBV source in 3 alternating weekly sessions, for ten minutes daily for 8 weeks, with a frequency of 60Hz and an amplitude of 2 mm. After the experimental period, the tibialis anterior muscle was removed and submitted to histological preparation. In the analysis of area, larger and smaller diameters of muscle fiber and percentage of connective tissue, no statistical differences were found. In the ratio of nuclei per fiber (N/F) and the number of total nuclei significant differences were identified between GP and GO (p<0,005). Considering the percentage of central nuclei, a reduction of the percentage was observed in trained animals in relation to sedentary ones. From the findings, it can be inferred that the time to induce the effects of hormonal privation was insufficient to cause sarcopenia of the tibialis anterior muscle in the oophorectomy groups, and the exercise protocol with WBV accelerates the muscle repair process.

The effects of stretching on muscle morphometry of ovariectomized rats

Abstract Introduction: Ageing is responsible for structural alterations, declining of all physiological variables, including range of motion and skeletal muscle function, known as sarcopenia. Objective: The aim of the study was to evaluate the effects of stretching on muscle morphometry in ovariectomized rats. Method: 21 female Wistar rats (12 weeks, 218 ± 22 g) were divided into 4 groups: control (CONTROL, n = 3) intact; ovariectomized and hysterectomized (OH, n = 6); Stretching (STRET, n = 6); ovariectomized and hysterectomized and stretching (OHS, n = 6). The rats were subjected to ovariectomy and hysterectomy. The stretching protocol of the soleus muscle lasted 10 repetitions of 1 minute with 45s interval between each repetition performed 3 times a week for 3 weeks. After 3 weeks, the rats were weighed and the muscles of both hind limbs were removed weighed and analyzed at muscle length; serial sarcomere number; sarcomere length; muscle fiber cross-sectional area (MFCSA) and percentage of connective tissue. Results: The final body weight increased in all groups. The serial sarcomere number of STRET was greater than the OH. The muscle fibers’ cross-sectional area of OHS was higher than CONTROL. Conclusion: It can be concluded that ovariectomy and hysterectomy prevented sarcomerogenesis even when stretching was applied. However, the stretching protocol enhanced muscle trophismof ovariectomized and hysterectomized rats. It might be suggested that longitudinal growth (serial sarcomeres) and radial (ASTFM) are differently regulated by stretching in intact and/or estrogen depleted (ovariectomy and hysterectomy) skeletal muscle.

2479-PUB: Mesenchymal Stromal Cells Improves Motor Function and Increases Collagen Macromolecular Organization in Muscles of Diabetic Rats

Diabetes mellitus affects the skeletal muscle connective tissue and leads to significant physical performance impairment. The use of mesenchymal stromal cells (MSCs) is an attractive strategy to modify the microenvironment and promote tissue repair and regeneration. Male Wistar rats (225 ± 25 g) were randomly assigned to 3 groups: Control (C), Diabetic (DM) and Diabetic treated with MSCs (DM-MSCs). Diabetes was induced by Streptozotocin (50 µg/kg). Bone marrow cells were isolated from the tibia and femur. After 10 weeks of DM induction, DM-MSC rats received 4 i.p. injections of MSCs (1 x 106). Ten weeks after MSC transplantation motor performance was evaluated by Rota Rod test and the anterior tibial (TA) muscles were collected for morphometric and quantification of collagen birefringence by polarizing microscopy analysis. Statistical significance was set at 0.05. Fasting glycemia was significantly higher and body mass was significantly lower in the Diabetic (DM) and Diabetic treated with MSCs (DM + MSCs) groups compared with control group. Motor performance of the DM group (30.1 ± 9.6 s) was significantly reduced when compared to the C group (727.2 ± 92 s) and increased significantly in DM + MSCs group (786.8 ± 109.5 s). The TA muscle mass was significantly reduced in DM and DM + MSCs groups compared with C group. The muscle fiber cross sectional area followed the same pattern. The connective tissue increased in DM group compared with C group and decreased in DM + MSCs. The percentage collagen birefringence quantified in the connective tissue of the TA muscle decreased significantly in DM group when compared to C group and increased in DM + MSCs group. Motor performance was positively correlated with collagen birefringence (r = 0.83; P &amp;lt; 0.0001) and negatively correlated with percentage of connective tissue (r = -0.94; P &amp;lt; 0.0001). The results indicate that improves both motor function and the collagen macromolecular organization in type 1 DM. Disclosure G.L. Luna: None. M.A. Sabadine: None. Y. Estrada-Bonilla: None. F. Freitas Aníbal: None. Â.M. Leal: None. Funding Conselho Nacional de Desenvolvimen to Científico e Tecnológico Processo (447518/2014-3)

Application of Histological and Physico-Chemical Analyses for Evaluation of Meat Product — Cachir

Abstract: Cachir sums up the whole charcuterie tradition Algerian is a product manufactured under the hygienic conditions imposed by the authorities to groups of meat processing trades. This meat product is made from beef or chicken, and is often seasoned with spices and olives during recent years, probably due to a significant reshuffle in eating habits. There has been an increase in the consumption of Cachir in Algeria. This study was carried out to determine the tissue and physicochemical composition of the Cachir on sale. Five different types of Cachir were bought at random from different local grocery stores in the Batna region (Algeria). From a physicochemical point of view, the majority of the samples have a water content of 64, 85 ± 0, 36 %. Meat products that have Aw of 0, 92±0,002, have pH of 6, 61±0,078. The histological evaluation provides the percentage of meat content (defined as the skeletal muscle content) with 0, 76 ±0, 21% and the percentage of connective tissue with 0, 16 ±0, 14 %. The quality of this meat product is closely related to the ratio of skeletal muscle and connective tissue with a value of 21, 05%. We found that these meat product were of poor quality, badly preserved. Keys words: Cachir, evaluation histology, physicochemical analysis.

Morphological and nociceptive effects of mechanical vibration on the sciatic nerve of oophorectomized Wistar rats

Abstract Aim: To evaluate the effects of whole-body vibration in the sciatic nerve of oophorectomized Wistar rats, on nociceptive and morphological parameters, such as fiber, axon, and myelin sheath diameters, G ratio, number of nerve fiber and nuclei of Schwann cells, and percentage of connective tissue. Method: Sixty-four rats were used in the groups sham-operate and oophorectomy (n = 32/group); after surgical procedures, each group was subdivided into four: euthanized in the 12th week, untreated and treated for four weeks; and euthanized in the 16th week, untreated and treated for eight weeks. The treatment with vibration was performed with a 60 Hz frequencies, for 10 minutes, three days a week, with duration of 4 or 8 weeks. Nociception was evaluated later, in the right paw, by means of a digital analgesimeter, prior to surgery, at the beginning and at the end of the protocol. After the trial period, the sciatic nerve was dissected for examination of the general morphology of the tissue and morphometric analysis; later, the animals were euthanized. Results: Regarding nociception and the morphometry of the sciatic nerve, independent of oophorectomy and treatment time, there was no statistically significant difference within and between groups. Also, the general morphology of the tissue in all groups had characteristics that were preserved. Conclusion: The mechanical vibration did not alter the nociceptive threshold and the morphological aspects of nerve fibers in oophorectomized Wistar rats.

Biomaterial-induced multinucleated giant cells express proinflammatory signaling molecules: A histological study in humans.

The biomaterials physicochemical characteristics influence their cellular reaction, degradation and regenerative capacities. Macrophages and multinucleated giant cells (MNGCs) are observed in the augmentation area of biomaterials. This study, for the first time, evaluated the polarization pattern of macrophages and MNGCs in response to two different bone substitute materials (synthetic bone substitute material [SBSM] = NanoBone vs. xenogeneic bone substitute material [XBSM] = Bio-Oss) in human bone biopsies compared to non-augmented bone (control). Histomorphometrical analysis of the polarization in proinflammatory (M1) and anti-inflammatory (M2) cells was performed using different immunohistochemical markers: CD-68 = macrophages; CCR-7 and Cox-2 (M1) and CD-206 and CD-163 (M2) and tartrate-resistant acid phosphatase (TRAP). The macrophage polarization pattern in SBSM showed a significantly higher number of M1 cells than did XBSM and non-augmented bone. XBSM induced a significantly higher number of CD-206-positive macrophages than SBSM did. No significant difference was found between XBSM and the non-augmented bone. MNGCs expressed CD-68 and TRAP. In both test-groups, MNGCs showed a high proinflammatory character (CCR-7 and Cox-2-positive) and their number in the SBSM group was significantly higher than that of XBSM. The tissue distribution showed a significantly low percentage of the remaining biomaterial in SBSM compared to XBSM. Within the limitations of this study, these findings show that MNGCs exhibit a rather proinflammatory character and lead to biomaterial degradation, once they are induced in a high number. The premature degradation of bone substitute materials is compensated with a high percentage of connective tissue and not new bone formation. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 780-790, 2019.

A prospective histomorphometric and cephalometric comparison of bovine bone substitute and autogenous bone grafting in Le Fort I osteotomies

PurposeThe aim of the present study was the histomorphometric and cephalometric comparison of autogenous bone grafting of the anterior iliac crest and the application of bovine bone substitute concerning new bone formation and postoperative stability in patients undergoing orthognathic Le Fort I osteotomy. Patients and methodsTwenty-five patients requiring orthognathic surgery with Le Fort I osteotomy were included in this study. Patients were randomly divided into three groups receiving either autogenous iliac crest BONE grafting (BONE; n = 8) or xenogenic bovine bone grafting (Bio-Oss®) in INTER (n = 12) or in ONLAY (n = 5) position. Histomorphometric analysis was performed using trephine bone biopsies from the autogenous, respectively xenogenic bone grafting region. Postoperative stability was evaluated using teleradiographies of three different timepoints. ResultsAll groups showed comparable mineralized fractions in bone biopsies of 50.2% (±13.2%) INTER, 46.48% (±12.3%) ONLAY and 57.1% (±20.6%) BONE as well as comparable percentage of connective tissue. Patients in the INTER-group revealed the lowest relapse rate of 20.5% (INTER) compared to 30.3% (ONLAY) and 33.0% (BONE). All groups underwent comparable maxillary advancement and healing time. ConclusionsPresent results indicate that block shaped bovine bone substitute is a promising alternative to autogenous bone grafting to bridge the Le Fort I osteotomy gap in orthognathic surgery.

587 Effects of Brazil nut (Bertholletia excelsea) oil-based diet on penile morphology of Wistar rats’

We aimed to evaluate if the diet based the oil of Bertholletia excelsa (Brazil nut) is able to reverse morphological changes in the penis of Wistar rats’ cause by an obesogenic diet. Wistar rats with 60 days of age were divided into 2 nutritional groups and received the diets until 90 days of age: control group (C, n=30) and high-fat group (lard-based diet), (HF, n=30). At the end of treatment, 10 animals from each group were sacrificed and the remainders were divided into 4 groups of 10 animals each. The groups received their respective experimental diets until 120 days-old: control group (C/C), control - Brazil nut group (C/Nts), high-fat group (HF/HF) and high-fat - Brazil nut group (HF/Nts). At sacrifice (120 days), blood glucose was evaluated and the blood was collected for analysis of total cholesterol (TC), LDL-c, HDL-c and triglycerides. The penises were collected and processed for histomorphometric analyzes of corpora cavernosa area with and without tunica albuginea (CC with TA and CC without TA), and tunica albuginea (TA) area, percentages of connective tissue, smooth muscle and sinusoidal spaces. The results were analyzed by one-way ANOVA and post-Holm-Sidak test, considering p<0.05 as significant.

Electrical Stimulation Based on Chronaxie Increases Fibrosis and Modulates TWEAK/Fn14, TGF-β/Myostatin, and MMP Pathways in Denervated Muscles.

The aim of this work was to investigate the effects of electrical stimulation (ES) of denervated muscles of rat in neuromuscular performance, muscle atrophy, and fibrosis formation. Wistar rats were divided into normal (N), 7- or 15-day denervation (D7d and D15d), D7d or D15d plus ES (DES7d and DES15d, respectively). Sciatic nerves were crushed causing muscle denervation. Two hundred muscle contractions were electrically induced daily by surface electrodes, considering muscle chronaxie. Sciatic functional index was used to determine neuromuscular performance during walking. The muscle fiber cross-sectional area and percentage of connective tissue were assessed by light microscopy. Molecular markers of extracellular matrix production and remodeling were evaluated. Metalloproteinase (MMP) activity was assessed by zymography, and TWEAK, Fn14, myostatin, and transforming growth factor (TGF)-β gene expressions were determined by real-time PCR. Electrical stimulation impaired natural recovery of walking at 15 days. In addition, ES induced fibrosis and accentuated muscle atrophy in denervated muscles. Although ES reduced the accumulation of TWEAK and myostatin expressions, it up-regulated Fn14 and TGF-β in a time-dependent manner. Electrical stimulation also increased the activity of MMP-2 compared to the other groups (P < 0.05). Electrical stimulation applied to denervated muscles induced muscle fibrosis and atrophy, as well as loss of performance. The TWEAK/Fn14 system, TGF-beta/myostatin pathway, and MMP activity seem to be involved in these deleterious changes.

The morphological and functional effects of exercise in the aquatic environment, performed before and/or after sciatic nerve compression in Wistar rats.

The aim of this study was to evaluate the effects of exercise in the aquatic environment, performed before and/or after sciatic nerve compression in Wistar rats on morphological and functional parameters. Twenty-five Wistar rats were divided into the following groups: control (C), lesion (L), trained+lesion (TL), lesion+exercise (LE), and training+lesion+exercise (TLE), who underwent right sciatic nerve compression on day 21 of the experiment. The TL and TLE groups were submitted to a jumping exercise in a water environment for 20 days prior to injury and the LE and TLE groups after injury. The functional analysis was carried out using the sciatic functional index (SFI). On the last day of the experiment, the right sciatic nerves were collected, processed and analysed according to morphology and morphometry. The C group showed higher SFI in relation to the other groups. In the morphometric analysis, in comparison to C, all groups showed a decrease in the diameter of the injured nerve fibre, the myelin sheath and an increase in the percentage of connective tissue. There was a decrease in axon diameter in L, TL, and LE groups and a decrease in the density of nerve fibres in the TL and LE groups. The exercise did not affect functional recovery. However, the exercise prior to the injury improved morphology of the nervous tissue, and when performed pre- and postinjury, there was also an improvement in nerve regeneration, but this was not the case with exercise performed after the injury demonstrating worse results.

Biological effects of compressive forces exerted on particulate bone grafts during socket preservation: animal study.

To compare different compressive forces exerted on a particulate graft material during socket preservation and their effects on bone regeneration. Six male dogs were used. The second, third, and fourth premolars, and the first molar were extracted bilaterally at the lower jaws. A particulate synthetic biphasic grafting material (60% HA and 40% β-tricalcium phosphate) was used. Three different standardized compressive forces were applied randomly during the socket preservation. The sample was divided into four experimental groups Test A (10g), Test B (50g), Test C (200g), and Control (empty sockets). Collagen membranes were placed, and primary closure was obtained. Two months after the surgery the animals were sacrificed, and histomorphometric analysis of non-decalcified samples was performed at the coronal, middle, and apical thirds. Grafted sockets resulted in higher bony contour (3±0.43mm2 ; P<0.05). The particles penetrated up to the apical third in the group C but not in the other test groups and controls (P<0.05). The percentage of new bone were higher at the coronal and apical thirds for Controls and group C compared to A and B groups (P<0.05). The residual graft was higher for group C (53±1.4%), followed by group B (45±3.1%) and group A (35±1.9%; P<0.05). The percentages of connective tissue were higher at the middle third without differences between groups (P>0.05). Within the limitations of this experimental animal study, it might be concluded that grafted sockets compressed with 200g force will have higher bony contours; higher compressive forces facilitate the penetration of the particulate graft material into the apical area of the socket and results in more bone formation at the coronal, middle, and apical thirds.

Effects of GaAs laser and stretching on muscle contusion in rats

ABSTRACT Laser and stretching are used to treat skeletal muscle injuries. This study aimed to evaluate the effects of GaAs laser and stretching in the morphology of the tibialis anterior (TA) muscle after contusion. Thirty-six male rats (349±23g) were divided into six groups (n=6): control group (CG); lesion group (LG); lesion and laser group (LLG); lesion and stretching group (LSG); lesion, laser and stretching group (LLSG); and stretching group (SG). TA was wounded by a contusion apparatus. We used GaAs laser 4.5 J/cm2 dose for 32 s each, beginning 48 h after lesion, for 7 days, once a day. Manual passive stretching was applied by 10 repetitions for 1 minute, initiating on the 8th day, once a day, 3 times a week, during 3 weeks. After 4 weeks, rats were euthanized and we analyzed: muscle weight and length, cross sectional area of muscle fibers (CSAMF), serial sarcomere number (SSN), sarcomere length, and percentage of connective tissue. Comparisons among groups were made by ANOVA and post hoc Tukey tests, with the significance level set at ≤ 0.05. The serial sarcomere number of LLSG was higher than LSG. The sarcomere length of LSG was superior to LLG, LLSG, and SG. SG increased SSN compared to CG, while the percentage of connective tissue of SG decreased in comparison to LLSG. Thus, the sarcomerogenesis of injured muscles was enhanced by laser therapy, stretching, and association of both. The stretching protocol was enough to increase SSN of intact muscles.