Heterologous fibrin biopolymer as an emerging approach to peripheral nerve repair: a scoping review.

Nerve injuries present a substantial challenge within the medical domain due to their prevalent occurrence and significant impact. In nerve injuries, a range of physiopathological and metabolic responses come into play to stabilize and repair the resulting damage. A critical concern arises from the disruption of connections at neuromuscular junctions, leading to profound degeneration and substantial loss of muscle function, thereby hampering motor tasks. While end-to-end neurorrhaphy serves as the established technique for treating peripheral nerve injuries, achieving comprehensive morphofunctional recovery remains a formidable challenge. In pursuit of enhancing the repair process, alternative and supportive methods are being explored. A promising candidate is the utilization of heterologous fibrin biopolymer, a sealant devoid of human blood components. Notably, this biopolymer has showcased its prowess in establishing a stable and protective microenvironment at the site of use in multiple scenarios of regenerative medicine. Hence, this scoping review is directed towards assessing the effects of associating heterologous fibrin biopolymer with neurorrhaphy to treat nerve injuries, drawing upon findings from prior studies disseminated through PubMed/MEDLINE, Scopus, and Web of Science databases. Further discourse delves into the intricacies of the biology of neuromuscular junctions, nerve injury pathophysiology, and the broader utilization of fibrin sealants in conjunction with sutures for nerve reconstruction procedures. The association of the heterologous fibrin biopolymer with neurorrhaphy emerges as a potential avenue for surmounting the limitations associated with traditional sealants while also mitigating degeneration in nerves, muscles, and NMJs post-injury, thereby fostering a more conducive environment for subsequent regeneration. Indeed, queries arise regarding the long-term regenerative potential of this approach and its applicability in reconstructive surgeries for human nerve injuries.

Morphology and computed tomography of the larynx in the white-eared opossum (Didelphis albiventris).

The white-eared opossum (Didelphis albiventris) is a Neotropical marsupial that occurs in the Brazilian territory. The larynx is an important organ of vocalization in mammals, although, other laryngeal functions are more fundamental for survival of mammals than phonation. The anatomical knowledge of respiratory structures is pivotal for a better understanding of the species. Thus, this study aimed to examine the larynx of the white-eared opossum by gross anatomy, computed tomography and histological description. For this, 10 adult (six females and four males) white-eared opossums (D. albiventris) were used. The white-eared opossum larynx was formed by epiglottis, thyroid, cricoids and arytenoid cartilages and a corniculate process. There is a similarity between the larynx of this marsupial and those reported in other wild mammals, regarding the number of cartilages and their location. Histologically, the epiglottis consisted of elastic cartilage and thyroid, cricoid and arytenoid cartilages were composed of hyaline cartilage. The epiglottis protruded rostrally into the nasal part of the pharynx, above the soft palate, and this is probably a marsupial characteristic as the fact that the thyroid and cricoid cartilages were ventrally fused. The hyoid apparatus was similar to that of other animals, with the same bony constitution, but with a greatly reduced stylohyoid bone. Histologically, the larynx was similar to those of other species such as koala, armadillo, crab-eating foxes and giant anteaters. The knowledge of the larynx morphology is important for the anatomical features of the species and clinical and surgical procedures, such as endotracheal intubation.

Effects of Nandrolone Decanoate on Skeletal Muscle and Neuromuscular Junction of Sedentary and Exercised Rats.

Background and Objectives: Nandrolone decanoate (ND) is the most widely used among the anabolic androgenic steroids (AAS), synthetic substances derived from testosterone, to improve muscular and health gains associated with exercises. The AAS leads to physical performance enhancement and presents anti-aging properties, but its abuse is associated with several adverse effects. Supraphysiological doses of AAS with or without physical exercise can cause morphological and functional alterations in neuromuscular interactions. This study aims to investigate the effects of ND supraphysiological doses in neuromuscular interactions, focusing on the soleus muscle and its neuromuscular junctions (NMJs) in rats, associated or not with physical exercise. Materials and Methods: Forty male Sprague Dawley rats were divided into four groups: sedentary and exercised groups, with or without ND at the dose of 10 mg/kg/week. The animals were treated for eight weeks, with intramuscular injections, and the soleus muscle was collected for morphological analyses. Results: The supraphysiological doses of ND in the sedentary group caused muscle degeneration, evidenced by splitting fibers, clusters of small fibers, irregular myofibrils, altered sarcomeres, an increase in collagen deposition and in the number of type I muscle fibers (slow-twitch) and central nuclei, as well as a decrease in fibers with peripheral nuclei. On the other hand, in the ND exercise group, there was an increase in the NMJs diameter with scattering of its acetylcholine receptors, although no major morphological changes were found in the skeletal muscle. Thus, the alterations caused by ND in sedentary rats were partially reversed by physical exercise. Conclusions: The supraphysiological ND exposure in the sedentary rats promoted an increase in muscle oxidative pattern and adverse morphological alterations in skeletal muscle, resulting from damage or post-injury regeneration. In the ND-exercised rats, no major morphological changes were found. Thus, the physical exercise partially reversed the alterations caused by ND in sedentary rats.

Neuroregeneration and immune response after neurorrhaphy are improved with the use of heterologous fibrin biopolymer in addition to suture repair alone.

INTRODUCTION/AIMS: Peripheral nerve injuries result in impaired neuromuscular interactions, leading to morphological and functional alterations. Adjuvant suture repair methods have been used to improve nerve regeneration and modulate the immune response. Heterologous fibrin biopolymer (HFB), a scaffold with adhesive properties, plays a critical role in tissue repair. The aim of this study is to evaluate neuroregeneration and immune response focusing on neuromuscular recovery, using suture-associated HFB for sciatic nerve repair. METHODS: Forty adult male Wistar rats were distributed into four groups (n = 10): C (control), only sciatic nerve location; D (denervated), neurotmesis and 6-mm gap removal and fixation stumps in subcutaneous tissue; S (suture), neurotmesis followed by suture; and SB (suture + HFB), neurotmesis followed by suture and HFB. Analysis of M2 macrophages (CD206+ ), as well as the morphology and morphometry of nerves, soleus muscle, and neuromuscular junctions (NMJs), were performed at 7 and 30 days after surgery. RESULTS: The SB group had the highest M2 macrophage area in both periods. After 7 days, SB was the only group similar to the C group regarding the number of axons; furthermore, after 30 days, the SB group was closer to the C group concerning blood vessel and central myonuclear numbers, NMJ angle, and connective tissue volume. After 7 days, increases in nerve area, as well as the number and area of blood vessels, were also observed in SB. DISCUSSION: HFB potentiates the immune response, increases axonal regeneration, induces angiogenesis, prevents severe muscle degeneration, and assists in NMJ recovery. In conclusion, suture-associated HFB has major implications for improved peripheral nerve repair.

Statin exposure during pregnancy promotes neuromuscular junction alterations in postpartum Wistar rats.

INTRODUCTION/AIMS: The mechanisms that underlie the pathogenesis of statin-associated muscle symptoms (SAMS) remain unclear. Pregnancy is associated with increased cholesterol levels. Statins may be useful during pregnancy, but their safety is uncertain. Hence, we investigated the postpartum effects of exposure to rosuvastatin and simvastatin during pregnancy in Wistar rats, targeting the neuromuscular structures. METHODS: Twenty-one pregnant Wistar rats were divided into three groups: control (C) treated with vehicle (dimethylsulfoxide + dH20), simvastatin (S) 62.5 mg/kg/day, and rosuvastatin (R) 10 mg/kg/day. Gavage was performed daily from the gestational days 8 to 20. At weaning, the postpartum mother tissues were collected and subjected to morphological and morphometric analysis of the soleus muscle, associated neuromuscular junctions (NMJs), and the sciatic nerve; protein quantification; quantification of the cholesterol and creatine kinase in the serum; and intramuscular collagen analysis. RESULTS: An increase in morphometric parameters (area, maximum and minimum diameters, Feret diameter, and minimum Feret) was observed in NMJs from the S and R groups in comparison with the C group, and there was also a loss of common NMJ circularity. The number of myofibers with central nuclei was higher in S (17 ± 3.9, P = .0083) and R (18.86 ± 14.42, P = .0498) than in C (6.8 ± 2.6). DISCUSSION: Gestational exposure to statins induced postpartum NMJ morphology alterations in soleus muscle, which may be caused by the remodeling of clusters of nicotinic acetylcholine receptors. This may be associated with the development and progression of SAMS observed in clinical practice.

Acetylcholine receptors of the neuromuscular junctions present normal distribution after peripheral nerve injury and repair through nerve guidance associated with fibrin biopolymer.

Peripheral nerve injuries (PNI) lead to alterations in the Agrin-LRP4-MuSK pathway. This results in disaggregation of AChRs and change from epsilon (mature, innervated) to gamma (immature, denervated) subunit. Tubulization technique has been shown to be effective for PNI repair and it also allows the use of adjuvants, such as fibrin biopolymer (FB). This study evaluated the effect of the association of tubulization with FB after PNI on AChRs and associated proteins. Fifty-two adults male Wistar rats were used, distributed in 4 experimental groups: Sham Control (S), Denervated Control (D); Tubulization (TB) and Tubulization + Fibrin Biopolymer (TB+FB). Catwalk was performed every 15 days. Ninety days after surgery the right soleus muscles and ischiatic nerves were submitted to the following analyses: (a) morphological and morphometric analysis of AChRs by confocal microscopy; (b) morphological and morphometric analysis of the ischiatic nerve; (c) protein quantification of AChRs: alpha, gama, and epsilon, of Schwann cells, agrin, LRP4, MuSK, rapsyn, MMP3, MyoD, myogenin, MURF1 and atrogin-1. The main results were about the NMJs that in the TB+FB group presented morphological and morphometric approximation (compactness index; area of the AChRs and motor plate) to the S group. In addition, there were also an increase of S100 and AChRε protein expression and a decrease of MyoD. These positive association resulted in AChRs stabilization that potentiate the neuromuscular regeneration, which strengthens the use of TB for severe injuries repair and the beneficial effect of FB, along with tubulization technique.

Heterologous fibrin biopolymer associated to a single suture stitch enables the return of neuromuscular junction to its mature pattern after peripheral nerve injury.

Denervation leads to severe atrophy of neuromuscular junction (NMJ) structure including decrease of the expression of fundamental proteins. Up to now, conventional suture has been the gold standard method used to correct this injury. Fibrin sealant is one of the alternatives proposed to optimize this method. This study verified if the association of fibrin sealant - Heterologous Fibrin Biopolymer (HFB) and a single suture stitch promotes return of morphology and NMJ structure to mature pattern after peripheral nerve injury. Forty Wistar rats were distributed into 4 groups: Sham-Control (SC), Denervated-Control (DC), Suture-Lesion (SL) and Suture-Lesion + HFB (SFS). In SC group only the right sciatic nerve identification was done. In DC, SL and SFS groups fixation of nerve stumps on musculature immediately after neurotmesis was performed. After seven days, stump reconnection with 3 stitches in SL and a single stitch associated with HFB in SFS were done. After sixty days right soleus muscles were prepared for nicotinic acetylcholine receptors (nAChRs) and nerve terminal confocal analyses, and for nAChRs (α1, ε e γ), S100, Agrin, LRP-4, MMP-3, Rapsyn western blotting analyses. SC group presented normal morphology. In DC group it was observed flattening of NMJ, fragmentation of nAChRs and tangled nerve terminals. The majority of the parameters of SL and SFS groups presented values in between SC and DC groups. There was an increase of relative planar area in these groups (SL and SFS) highlighting that there was less nAChRs fragmentation and the values of protein expression showed return of nAChRs to mature pattern. Use of HFB associated with a single suture stitch decreased surgical time, minimized suture injuries, did not alter nerve regeneration and presented potential to reestablish the NMJ apparatus. These consolidated results encourage surgeons to develop future clinical trials to install definitively this new approach both for reconstructive surgery and neurosurgery.

Heterologous fibrin sealant potentiates axonal regeneration after peripheral nerve injury with reduction in the number of suture points.

The use of suture associated with heterologous fibrin sealant has been highlighted for reconstruction after peripheral nerve injury, having the advantage of being safe for clinical use. In this study we compared the use of this sealant associated with reduced number of stitches with conventional suture after ischiatic nerve injury. 36 Wistar rats were divided into 4 groups: Control (C), Denervated (D), ischiatic nerve neurotmesis (6 mm gap); Suture (S), epineural anastomosis after 7 days from neurotmesis, Suture + Fibrin Sealant (SFS), anastomosis with only one suture point associated with Fibrin Sealant. Catwalk, electromyography, ischiatic and tibial nerve, soleus muscle morphological and morphometric analyses were performed. The amplitude and latency values of the Suture and Suture + Fibrin Sealant groups were similar and indicative of nerve regeneration.The ischiatic nerve morphometric analysis in the Suture + Fibrin Sealant showed superior values related to axons and nerve fibers area and diameter when compared to Suture group. In the Suture and Suture + Fibrin Sealant groups, there was an increase in muscle weight and in fast fibers frequency, it was a decrease in the percentage of collagen compared to group Denervated and in the neuromuscular junctions, the synaptic boutons were reestablished.The results suggest a protective effect at the lesion site caused by the fibrin sealant use. The stitches reduction minimizes the trauma caused by the needle and it accelerates the surgical practice. So the heterologous fibrin sealant use in nerve reconstruction should be considered.

Neuromuscular junctions (NMJs): ultrastructural analysis and nicotinic acetylcholine receptor (nAChR) subunit mRNA expression in offspring subjected to protein restriction throughout pregnancy.

Protein restriction during gestation can alter the skeletal muscle phenotype of offspring; however, little is known with regard to whether this also affects the neuromuscular junction (NMJ), as muscle phenotype maintenance depends upon NMJ functional integrity. This study aimed to evaluate the effects of a low protein (6%) intake by dams throughout gestation on male offspring NMJ morphology and nicotinic acetylcholine receptor (nAChR) α1, γ and ε subunit expression in the soleus (SOL) and extensor digitorum longus (EDL) muscles. Four groups of male Wistar offspring rats were studied. The offspring of dams fed low-protein (6% protein, LP) and normal protein (17% protein, NP) diets were evaluated at 30 and 120 days of age, and the SOL and EDL muscles were collected for analysis. Morphological studies using transmission electron microscopy revealed that only SOL NMJs were affected in 30-day-old offspring in the LP group compared with the NP group. SOL NMJs exhibited fewer synaptic folds, the postsynaptic membranes were smooth and myelin figures were also frequently observed in the terminal axons. With regard to the expression of mRNAs encoding nAChR subunits, only 30-day-old LP offspring EDL muscles exhibited reduced α, γ and ε subunit expression compared with the NP group. In conclusion, our results demonstrate that a low-protein diet (6%) imposed throughout pregnancy impairs the expression of mRNAs encoding the nAChR α, γ and ε subunits in EDL NMJs and promotes morphological changes in SOL NMJs of 30-day-old offspring, indicating specific differences among muscle types following long-term maternal protein restriction.

Effects of duodenal-jejunal bypass on structure of diaphragm in western diet obese rats.

PURPOSE:: To evaluate the effects of duodenal-jejunal bypass (DJB) on the diaphragm muscle of obese rats fed on a western diet (WD) . METHODS:: Eighteen male Wistar rats were fed a standard rodent chow diet (CTL group) or WD ad libitum. After 10 weeks, WD rats were submitted to sham (WD SHAM) or duodenal-jejunal bypass (WD DJB). The structure, ultrastructure, collagen content and the morphometry of the neuromuscular junctions (NMJs) were analyzed two months after surgery. RESULTS:: WD SHAM rats displayed an increase in body weight, the Lee index and retroperitoneal and peri-epididymal fat pads compared to the CTL group. DJB did not alter these parameters. The muscle fiber structure and NMJs were similar in the WD SHAM and CTL groups. However, the WD SHAM group showed alterations in the fiber ultrastructure, such as loosely arranged myofibrils and Z line disorganization. In addition, WD SHAM animals presented a considerable amount of lipid droplets and a reduction in the percentage of collagen compared to the CTL group. DJB did not affect the structure or ultrastructure of the muscle fibers or the NMJs in the diaphragm of the WD DJB animals. CONCLUSION:: Duodenal-jejunal bypass did not improve the alterations observed in the diaphragm of western diet obese-rats.

GaAs laser therapy reestablishes the morphology of the NMJ and nAChRs after injury due to bupivacaine.

BACKGROUND: Local anesthetics are used to relieve pre- and postoperative pain, acting on both sodium channels and nicotinic acetylcholine receptors (nAChR) at the neuromuscular junction (NMJ). Bupivacaine acts as a non-competitive antagonist and has limitations, such as myotoxicity, neurotoxicity, and inflammation. Low-level laser therapy (LLLT) has anti-inflammatory, regenerative, and analgesic effects. The aim of the present study was to evaluate the effects of a gallium arsenide laser (GaAs) on the morphology of the NMJ and nAChRs after application of bupivacaine in the sternomastoid muscle. METHODS: Thirty-two adult male Wistar rats received injections of bupivacaine 0.5% (Bupi: right antimere) and 0.9% sodium chloride (Cl: left antimere). Next, the animals were divided into a Control group (C) and a Laser group (LLLT). The laser group received LLLT (GaAs 904nm, 50mW, 4,8J) in both antimeres for five consecutive days. After seven days, the animals were euthanized and the surface portion of the sternomastoid muscle was removed, frozen, and subjected to morphological and morphometric analyses of the NMJs (nonspecific esterase reaction), confocal laser scanning, and an ultrastructural analysis. The nAChRs were quantified by Western blotting. RESULTS: In the chloride group, the morphology and morphometry of the NMJs remained stable. The maximum diameters of the NMJs were lower in the Bupi (15.048±1.985) and LLLT/Bupi subgroups (15.456±1.983) compared to the Cl (18.502±2.058) and LLLT/Cl subgroups (19.356±2.522) (p<0.05). Ultrastructurally, LLLT reduced myonecrosis observed after application of bupivacaine, with recovery in the junctional folds and active zone. There was an increase in the perimeter of the LLLT/Bupi subgroup (150.33) compared to the Bupi subgroup (74.69) (p<0.01) observed by confocal microscopy. There was also an increase in the relative planar area of the NMJ after LBI (8.75) compared to CBupi (4.80) (p<0.01). An analysis of the protein expression of nAChRα1 showed no major differences in the groups studied. There was an increase in protein expression of the ε subunit after application of LLLT (13.055) compared to Bupi (0.251) (p<0.01). Taken together, the present experiments indicate that there was a positive association of the α and γ subunits (p<0.05). CONCLUSIONS: These results demonstrate that LLLT at the dose used in this study reduced structural alterations in the NMJ and molecular changes in nAChRs triggered by bupivacaine, providing important data supporting the use of LLLT in therapeutic protocols for injuries triggered by local anesthetics.

Effects of duodenal-jejunal bypass on structure of diaphragm in western diet obese rats

Abstract Purpose: To evaluate the effects of duodenal-jejunal bypass (DJB) on the diaphragm muscle of obese rats fed on a western diet (WD) . Methods: Eighteen male Wistar rats were fed a standard rodent chow diet (CTL group) or WD ad libitum. After 10 weeks, WD rats were submitted to sham (WD SHAM) or duodenal-jejunal bypass (WD DJB). The structure, ultrastructure, collagen content and the morphometry of the neuromuscular junctions (NMJs) were analyzed two months after surgery. Results: WD SHAM rats displayed an increase in body weight, the Lee index and retroperitoneal and peri-epididymal fat pads compared to the CTL group. DJB did not alter these parameters. The muscle fiber structure and NMJs were similar in the WD SHAM and CTL groups. However, the WD SHAM group showed alterations in the fiber ultrastructure, such as loosely arranged myofibrils and Z line disorganization. In addition, WD SHAM animals presented a considerable amount of lipid droplets and a reduction in the percentage of collagen compared to the CTL group. DJB did not affect the structure or ultrastructure of the muscle fibers or the NMJs in the diaphragm of the WD DJB animals. Conclusion: Duodenal-jejunal bypass did not improve the alterations observed in the diaphragm of western diet obese-rats.

Effects of short-term severe and long-term mild STZ-induced diabetes in urethral tissue of female rats.

AIMS: To estimate and compare the alterations in the urethral tissues of female rats with two diabetes models: short-term severe and long-term mild diabetes. METHODS: To induce mild diabetes (blood glucose levels between 120 and 300 mg/dl), female newborns received streptozotocin (100 mg/kg body weight, sc route), and to induce short-term severe diabetes (blood glucose levels > 300 mg/d), adult animals received streptozotocin (40 mg/kg, iv route). The rats were killed on day 133 of the experimental via an i.p. Thiopentax® injection of 80 mg/kg, and the urethrovaginal tissues were harvested. Morphometric, pathological, immunohistochemical, and ultrastructural analyses were conducted. RESULTS: In the long-term mild diabetes group, collagen deposition, severe fibrosis, lipid droplets and numerous subsarcolemmal, and intermyofibrillar mitochondria were observed. In the short-term severe diabetes group, centrally located myonuclei and a significantly reduced striated muscle area were noted. Both diabetic models exhibited similar immunohistochemistry patterns, with changes from fast to slow fibers and a decrease in the numbers of fast fibers. CONCLUSIONS: Either long-term mild hyperglycemia or short-term severe hyperglycemia have detrimental impacts on muscle health. They are both involved in the failure to maintain healthy skeletal muscle that may contribute to the development of pelvic floor dysfunctions via different pathways. These results have important implications for monitoring and prevention strategies for improving the quality of life of women with diabetes mellitus and pelvic floor muscle dysfunction. Neurourol. Urodynam. 36:574-579, 2017. © 2016 Wiley Periodicals, Inc.

Maternal protein restriction during pregnancy and lactation affects the development of muscle fibers and neuromuscular junctions in rats.

INTRODUCTION: A balanced maternal diet is a determining factor in normal fetal development. The objective of this study was to evaluate the effects of maternal protein restriction during pregnancy and lactation on muscle fiber and neuromuscular junction (NMJ) morphology of rat offspring at 21 days of age. METHODS: Wistar rats were divided into a control group (CG), offspring of mothers fed a normal protein diet (17%), and a restricted group (RG), offspring of mothers fed a low-protein diet (6%). After a period of lactation, the animals were euthanized, and soleus muscles were obtained from pups for analysis. RESULTS: The soleus muscles of the RG exhibited an increase of 133% in the number of fibers and of 79% in the amount of nuclei. Moreover, the number of NMJs was lower in the restricted group than in the CG. CONCLUSIONS: Maternal protein restriction alters the normal development of the neuromuscular system. Muscle Nerve 55: 109-115, 2017.

Aerobic training attenuates nicotinic acethylcholine receptor changes in the diaphragm muscle during heart failure.

INTRODUCTION: Heart failure (HF) is a progressive myopathy, with clinical signs of fatigue and limb weakness that can damage the nerve-muscle interaction, altering synaptic transmission and nicotinic acetylcholine receptors (nAChR) in neuromuscular junctions (NMJs). The diaphragm is composed of a mixed proportion of muscle fibres, and during HF, this muscle becomes slower and can alter its function. As exercise training is an accepted practice to minimise abnormalities of skeletal muscle during HF, in this study, we evaluated the hypothesis that aerobic training attenuates alterations in the expression of nAChR subunits in NMJs diaphragm during heart failure. OBJECTIVE: The aim of this study was to evaluate the distribution and expression of nAChR subunits in the diaphragm muscle fibres of rats subjected to an aerobic training programme during HF. METHODS: Control (Sham), control training (ShamTR), aortic stenosis (AS) and aortic stenosis training (ASTR) groups were evaluated. The expression of nAChR subunits (γ, α1, ε, ß1 and δ) was determined by qRT-PCR, and NMJs were analysed using confocal microscopy. RESULTS: We observed increased expression of the γ, α1 and ß1 subunits in the AS group compared with the ASTR group. The distribution of NMJs was modulated in these groups. DISCUSSION: HF alters the mRNA expression of nAChR subunits and the structural characteristics of diaphragm NMJs. In addition, aerobic training did not alter NMJs morphology but attenuated the alterations in heart structure and function and in nAChR subunit mRNA expression. Our findings demonstrate the beneficial effects of aerobic exercise training in maintaining the integrity of the neuromuscular system in the diaphragm muscle during HF and may be critical for non-pharmacological therapy to improve the quality of life for patients with this syndrome.

Urethral striated muscle and extracellular matrix morphological characteristics among mildly diabetic pregnant rats: translational approach.

INTRODUCTION AND HYPOTHESIS: Diabetes mellitus (DM) during pregnancy is associated with high levels of urinary incontinence (UI) and pelvic floor muscle dysfunction. Mild DM can lead to changes in urethral striated muscle and extracellular matrix (ECM) in pregnant rats considering both structures as an entire system responsible for urinary continence. METHODS: Ninety-two female Wistar rats were distributed in four experimental groups: virgin, pregnant, diabetic, and diabetic pregnant. In adult life, parental nondiabetic female rats were mated with nondiabetic male rats to obtain newborns. At the first day of birth, newborns received citrate buffer (nondiabetic group) or streptozotocin 100 mg/kg body weight, subcutaneous route (mild DM group). At day 21 of the pregnancy, the rats were lethally anesthetized and the urethra and vagina were extracted as a unit. Urethral and vaginal sections were cut and analyzed by: (a) cytochemical staining for ECM and muscle structural components, (b) immunohistochemistry to identify fast- and slow-muscle fibers, and (c) transmission electron microscopy for ultrastructural analysis of urethral striated muscle. RESULTS: In comparison with the three control groups, variations in the urethral striated muscle and ECM from diabetic pregnant rats were observed including thinning, atrophy, fibrosis, increased area of blood vessels, mitochondria accumulation, increased lipid droplets, glycogen granules associated with colocalization of fast and slow fibers, and a steady decrease in the proportion of fast to slow fibers. CONCLUSIONS: Mild DM and pregnancy can lead to a time-dependent disorder and tissue remodeling in which the urethral striated muscle and ECM has a fundamental function.

EPA protects against muscle damage in the mdx mouse model of Duchenne muscular dystrophy by promoting a shift from the M1 to M2 macrophage phenotype.

In dystrophic mdx mice and in Duchenne muscular dystrophy, inflammation contributes to myonecrosis. Previously, we demonstrated that eicosapentaenoic acid (EPA) decreased inflammation and necrosis in dystrophic muscle. In the present study, we examined the effects of EPA and the corticoid deflazacort (DFZ) as modulators of M1 (iNOS-expressing cells) and M2 (CD206-expressing cells) macrophages. Mdx mice (14 days old) received EPA or DFZ for 16 days. The diaphragm, biceps brachii and quadriceps muscles were studied. Immunofluorescence, immunoblotting and ELISA assays showed that EPA increased interleucin-10, reduced interferon-γ and was more effective than DFZ in promoting a shift from M1 to M2.

Maternal protein restriction induce skeletal muscle changes without altering the MRFs MyoD and myogenin expression in offspring.

Stimuli during pregnancy, such as protein restriction, can affect morphophysiological parameters in the offspring with consequences in adulthood. The phenomenon known as fetal programming can cause short- and long-term changes in the skeletal muscle phenotype. We investigated the morphology and the myogenic regulatory factors (MRFs) MyoD and myogenin expression in soleus, SOL; oxidative and slow twitching and in extensor digitorum longus, EDL; glycolytic and fast twitching muscles in the offspring of dams subjected to protein restriction during pregnancy. Four groups of male Wistar offspring rats were studied. Offspring from dams fed a low-protein diet (6 % protein, LP) and normal protein diet (17 % protein, NP) were euthanized at 30 and 112 days old, and their muscles were removed and kept at -80 °C. Muscles histological sections (8 µm) were submitted to a myofibrillar adenosine triphosphatase histochemistry reaction for morphometric analysis. Gene and protein expression levels of MyoD and myogenin were determined by RT-qPCR and western blotting. The major findings observed were distinct patterns of morphological changes in SOL and EDL muscles in LP offspring at 30 and 112 days old without changes in MRFs MyoD and myogenin expression. Our results indicate that maternal protein restriction followed by normal diet after birth induced morphological changes in muscles with distinct morphofunctional characteristics over the long term, but did not alter the MRFs MyoD and myogenin expression. Further studies are necessary to better understand the mechanisms underlying the maternal protein restriction response on skeletal muscle.

Diabetes na gestação e incontinência urinária: uma associação pouco reconhecida / Diabetes in pregnancy and urinary incontinence: a little acknowledged association

Incontinência Urinária (IU) feminina é definida como toda perda involuntária de urina. É uma condição frequente, de alto custo econômico para o governo e que implica em danos físicos, psicológicos, sociais e pior qualidade de vida para as mulheres. Inúmeros são os fatores de risco envolvidos no desenvolvimento da IU, porém a associação com o diabetes mellitus (DM) é de grande interesse atualmente. DM afeta múltiplos sistemas orgânicos, incluindo o sistema urinário em aproximadamente 52% dos pacientes diabéticos e dos que apresentam apenas hiperglicemia, porém ainda não é totalmente explicada a associação entre diabetes mellitus gestacional e IU. O profissional de saúde deve estar atento a esse novo parâmetro e procurar analisá-lo de forma mais pormenorizada para que medidas profiláticas e terapêuticas sejam estabelecidas.Há necessidade de delinear a cronologia da relação entre DMG e as complicações urinárias, a relação entre o diabetes controlado e a incidência de incontinência e modalidades de tratamento efetivo para pacientes diabéticos com sintomas no trato urinário inferior.

Urinary incontinence (UI) in women is defined as any involuntary urine loss. This is a frequent condition of high economic cost to the government that also results in women’s physical, psychological and social damage and impaired quality of life. Various risk factors are involved in UI development; however, association with diabetes mellitus (DM) is of great interest at present. DM affects multiple organ systems, including the urinary system in approximately 52% of diabetic patients and in those showing only hyperglycemia; however, the association between gestational diabetes mellitus and UI has not been fully explained. Health care professionals must be attentive to this new parameter and attempt to analyze it in more detail so that prophylactic and therapeutic measures can be established. It is necessary to delineate the chronology of the relation ship between gestational diabetes mellitus and urinary complications, the relationship between controlled diabetes and the incidence of incontinence as well as effective treatment modalities for diabetic patients with symptoms in the lower urinary tract.

Effect of Citrus aurantium L. essential oil on muscle regeneration in mdx mice / Efecto del aceite esencial de Citrus aurantium L. en la regeneración muscular en ratones mdx

Duchenne muscular dystrophy (DMD) is a severe X-linked recessive disorder characterized by the progressive loss of muscular strength. Mdx mutant mice show a marked deficiency in dystrophin, which was related to muscle membrane stability. The aim of this study was to verify the possible protective anti-inflammatory effect of citrus oil on mdx muscle fibers. Thus, adult male and female mdx mice (014/06-CEEA) were divided into control and citrus-treated. After 60 days of treatment, one ml of blood was collected for creatine kinase (CK) test. Diaphragm, sternomastoideus, anterior tibial and gastrocnemius muscles were removed and processed according to histological routine methods. The observed alterations indicate a direct effect of citrus. Recent studies have improved the diagnosis of muscular diseases but with no definitions of efficient treatments. Intervention with several therapies is important to many patients presenting muscular dystrophy, which enables them to live longer and be more active, while there is no development of gene therapies.

La distrofia muscular de Duchenne (DMD) es una enfermedad grave ligada al cromosoma X, trastorno recesivo que se caracteriza por la pérdida progresiva de fuerza muscular. Mdx ratones mutantes muestran una marcada deficiencia en la distrofina, que está relacionada con la estabilidad de la membrana muscular. El objetivo de este estudio fue comprobar el posible efecto protector, antiinflamatorio del aceite de cítricos en las fibras musculares mdx. Los ratones mdx adultos machos y hembras (014/06-CEEA) se dividieron en control y cítricos tratados. Después de 60 días de tratamiento, un ml de sangre fue recogida para cuantificar la creatina quinasa (CK) de prueba. Fueron retirados y procesados los músculos diafragma, esternomastoideo, tibial anterior y gastrocnemio de acuerdo con los métodos de rutina histológica. Las alteraciones observadas indican un efecto directo de los cítricos. Estudios recientes han mejorado el diagnóstico de enfermedades musculares, pero sin definiciones de tratamientos eficaces. Intervención con varias terapias es importante para muchos pacientes que presentan distrofia muscular, lo que les permite vivir más y ser más activos, mientras no exista desarrollo de terapias génicas.