Photobiomodulation modulates the expression of inflammatory cytokines during the compensatory hypertrophy process in skeletal muscle

Compensatory hypertrophy (CH) occurs due to excessive mechanical load on a muscle, promoting an increase in the size of muscle fibers. In clinical practice, situations such as partial nerve injuries, denervation, and muscle imbalance caused by trauma to muscles and nerves or diseases that promote the loss of nerve conduction can induce CH in muscle fibers. Photobiomodulation (PBM) has demonstrated beneficial effects on muscle tissue during CH. The aim of the present study was to evaluate the effect of PBM on the inflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) as well as type 2 metalloproteinases (MMP-2) during the process of CH due to excessive load on the plantaris muscle in rats. Forty-five Wistar rats weighing 250 g were divided into three groups: control group (n = 10), hypertrophy (H) group (n = 40), and H + PBM group (n = 40). CH was induced through the ablation of synergist muscles of the plantaris muscle. The tendons of the gastrocnemius and soleus muscles were isolated and sectioned to enable the partial removal of each of muscle. The preserved plantaris muscle below the removed muscles was submitted to excessive functional load. PBM was performed with low-level laser (AsGaAl, λ = 780 nm; 40 mW; energy density: 10 J/cm²; 10 s on each point, 8 points; 3.2 J). Animals from each group were euthanized after 7 and 14 days. The plantaris muscles were carefully removed and sent for analysis of the gene and protein expression of IL-6 and TNF-α using qPCR and ELISA, respectively. MMP-2 activity was analyzed using zymography. The results were submitted to statistical analysis (ANOVA + Tukey's test, p < 0.05). The protein expression analysis revealed an increase in IL-6 levels in the H + PBM group compared to the H group and a reduction in the H group compared to the control group. A reduction in TNF-α was found in the H and H + PBM groups compared to the control group at 7 days. The gene expression analysis revealed an increase in IL-6 in the H + PBM group compared to the H group at 14 days as well as an increase in TNF-α in the H + PBM group compared to the H group at 7 days. Increases in MMP-2 were found in the H and H + PBM groups compared to the control group at both 7 and 14 days. Based on findings in the present study, it is concluded that PBM was able to modulate pro-inflammatory cytokines that are essential for the compensatory hypertrophy process. However, it has not shown a modulation effect directly in MMP-2 activity during the same period evaluated.

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.

Effect of nandrolone decanoate on skeletal muscle repair

This study analyzed the effect of nandrolone decanoate (ND) on muscle repair and the expression of myogenic regulatory factors following cryoinjury in rat skeletal muscle. Adult male Wistar rats were randomly divided into 4 groups: control group, sham group, cryoinjured group treated with ND and non-injured group treated with ND. Treatment consisted of subcutaneous injections of ND (5 mg/kg) twice a week. After sacrifice, the tibialis anterior muscle was removed for the isolation of total RNA and analysis of myogenic regulatory factors using real-time PCR as well as morphological analysis using the hematoxylin-eosin assay. There was a significant increase in MyoD mRNA after 7 days and in myogenin mRNA after 21 days in the cryoinjured ND group in comparison to other groups in the same period. The morphological analysis revealed no edema or myonecrosis after 7 days as well as no edema or inflammatory infiltrate after 14 days in the cryoinjured ND group. In conclusion the anabolic steroid nandrolone decanoate can modulate the muscle repair process in rats following cryoinjury by influencing the expression of regulatory myogenic factors and phases of muscle repair.

Occlusal contact in children with Temporomandibular Disorders. A pilot study

AIM

The aim of the present study was to perform a comparative analysis of occlusal contact points in children with and without signs and symptoms of Temporomandibular Disorders (TMD).

STUDY DESIGN

Cross-sectional study. One hundred fifty children between 6 and 14 years of age were evaluated using the Helkimo questionnaire and a clinical exam. The occlusal contact points in each child were recorded during maximal intercuspation with the aid of carbon strips. Digital photographs were taken of the upper and lower arches before and after recording the occlusal contacts. The number of contact points between sides were compared and recorded on individual charts (occlusograms).

STATISTICS

Student's t-test and Pearson's chi-square test were used for the statistical analysis, with the level of significance set at 0.05, which revealed no statistically significant differences between genders. The Student's t-test revealed a statistically significant difference in the mean number of occlusal contact points between the participants with and without TMD, with a higher number of contact points among those without TMD. There was no significant difference between sides. RESULTS The results of this study show a difference in the number of occlusal contact points in centric occlusion between children with and without TMD. CONCLUSION Regardless of the degree of severity, the number of occlusal contact points is lower among children with TMD.

Rehabilitation of exacerbated case of oral mucositis associated with renal failure following bone marrow transplantation

Inflammation of oral mucosa induced by anti neoplastic drugs is an important, dose limiting and costly side effect of cancer therapy. Here is presented an exacerbated case of oral mucositis associated with renal failure in a patient who underwent bone marrow transplantation. The clinical aspects and an integrated rehabilitation program are discussed below.

Orofacial lesions in treated southeast Brazilian leprosy patients: a cross-sectional study

AIM

The aim of the present study was to clinically evaluate the oral mucosa lesions of leprosy patients during and after multi-drug therapy.

METHODS

Clinical examination, medical and dental history examination was performed in 100 leprosy patients.

RESULTS

The results revealed that 71 patients, 50 men and 21 women, exibited oral lesions. The most frequent lesions were: fissured tongue (18 cases), inflammatory papillary hyperplasia (16 cases), chronic atrophic candidiasis (10 cases), fibroma (10 cases), erythematous candidiasis (eight cases), and traumatic ulceration (seven cases).

CONCLUSION

We conclude that leprosy-related lesions are not present in patients undergoing treatment for leprosy, probably due to response to multidrug therapy.

Intraosseous schwannoma mimicking a periapical lesion on the adjacent tooth: case report

AIM

To present an additional case of intraosseous schwannoma involving the apical area in the mandibular alveolar bone mimicking an inflammatory periapical lesion.

SUMMARY

This article describes a case of schwannoma periapically located mimicking an inflammatory periapical lesion in the mandible of a 34-year-old female. Diagnostic and therapeutic problems can occur when this lesion is misinterpreted as being endodontic in origin. The diagnosis, radiograph, immunohistochemical aspects and treatment are also discussed.

KEY LEARNING POINTS

Intraosseous schwannoma is a rare unilocular radiolucency that when located periapically could be misdiagnosed as an endodontic lesion and result in unnecessary root canal treatment. The vitality of the pulp is an important test to exclude lesions of inflammatory origin. Histological examination is important to establish the diagnosis of lesions in the periradicular region.