Large Amounts Of Collagen Research Articles

Dissociated urethral plate Onlay and standard Onlay urethroplasty for mid-distal hypospadias: A comparative study

BackgroundUrethral plate(UP) reserved Onlay urethroplasty currently had been widely used in mid-distal hypospadias. However, for children with 15-30° bending after degloving, only dorsal tunica albuginea plication was performed to correct penile ventral curvature(VC), and long-term follow-up showed a high recurrence rate of penile curvature. We developed a modified Onlay urethroplasty which dissociated the UP and completely removed the tissue beneath UP to fully correct penile curvature, and compared it with the standard Onlay urethroplasty to explore its rationality and feasibility. MethodsWe prospectively collected clinical data from 68 children with hypospadias who underwent standard or modified Onlay urethroplasty between September 2019 and June 2021, and evaluated interim outcomes to identify the complications between two groups. And we conducted histological examination of the tissue beneath the UP. ResultsA total of thirty-two patients underwent modified Onlay urethroplasty. Intraoperative curvature measurements showed that 37.5% (12/32) of patients had completely straightened their penis after dissecting UP and removing fibrous tissue beneath it. A total of thirty-six patients underwent standard Onlay urethroplasty. Totally five fistulas were reported in the first and second groups, respecitively as well as the complication rates were 15.6% and 13.9%, respectively (P > 0.05). The histological results showed that the tissue below the UP contains a large amount of collagen, mainly type I collagen. ConclusionThe dissociated UP Onlay urethroplasty can maximally remove factors limiting penis growth and completely correct penile curvature, without increasing the incidence of postoperative complications.Therefore, we recommend the application of improved Onlay urethroplasty in children with mid-distal hypospadias.

Review of the slaughter wastes and the meat by-products recycling opportunities

In the ancient times, the Kazakhstan population were considered as nomadic people, where a cult of all types of cattle breeding had a leading position. However, currently the processing approaches of livestock slaughter wastes and secondary meat raw materials are weakly developed. The presented review of waste-free technologies considers the utilization processes of following: carcasses, skins, bones, meat scraps, blood, adipose tissue, horns, feet, hooves, and internal organs. These substances are an important source of animal protein, collagen, bioactive peptides, blood plasma, minerals, and fats that can be applied in various industries: food, feed, medical, and technological. When slaughtering livestock, meat on bones makes up almost half of the total weight of livestock, yet the remaining half contains offal and inedible raw materials. Blood consists of: erythrocytes, leukocytes, platelets, and plasma. Animal bones have mostly proteins (30–50%) and lipids (13–20%) from bone tissues. Tendons, bones and skins contain a large amount of collagen. Animal fat and adipose tissue have 54.9% saturated acids, 40.9% unsaturated fatty acids and 4.2% polyunsaturated fatty acids. Bioactive peptides from collagen derivatives contain from 2 to 20 amino acids and have various biological (antihypertensive, antioxidant, and antimicrobial) activity. This review considers a world current status, modern prospects and opportunities in the slaughter wastes and the meat by-products recycling technologies. Overview of existing approaches for waste processing with the subsequent use of the final product in the food industry, the production of feed, medicines and technical products is considered. The complete processing within the slaughtering livestock and the secondary meat raw materials allows to expand the wide-range products with a low prime cost, thereby promoting to the sustainable development of agroecology by applying the waste hierarchy: Reducing, Reusing, and Recycling.

Acellular fish skin grafts in the treatment of diabetic wounds: Advantages and clinical translation.

Diabetic wounds cannot undergo normal wound healing due to changes in the concentration of hyperglycemia in the body and soon evolve into chronic wounds causing amputation or even death of patients. Diabetic wounds directly affect the quality of patients and social medical management; thus researchers started to focus on skin transplantation technology. The acellular fish skin grafts (AFSGs) are derived from wild fish, which avoids the influence of human immune function and the spread of the virus through low-cost decellularization. AFSGs contain a large amount of collagen and omega-3 polyunsaturated fatty acids and they have an amazing effect on wound regeneration. However, after our search in major databases, we found that there were few research trials in this field, and only one was clinically approved. Therefore, we summarized the advantages of AFSGs and listed the problems faced in clinical use. The purpose of this paper is to enable researchers to better carry out original experiments at various stages.

Recent Advances in the Nutrition and Metabolism of Dogs and Cats.

Domestic dogs (facultative carnivores) and cats (obligate carnivores) have been human companions for at least 12,000 and 9000 years, respectively. These animal species have a relatively short digestive tract but a large stomach volume and share many common features of physiological processes, intestinal microbes, and nutrient metabolism. The taste buds of the canine and feline tongues can distinguish sour, umami, bitter, and salty substances. Dogs, but not cats, possess sweet receptors. α-Amylase activity is either absent or very low in canine and feline saliva, and is present at low or substantial levels in the pancreatic secretions of cats or dogs, respectively. Thus, unlike cats, dogs have adapted to high-starch rations while also consuming animal-sourced foods. At metabolic levels, both dogs and cats synthesize de novo vitamin C and many amino acids (AAs, such as Ala, Asn, Asp, Glu, Gln, Gly, Pro, and Ser) but have a very limited ability to form vitamin D3. Compared with dogs, cats have higher requirements for AAs, some B-complex vitamins, and choline; greater rates of gluconeogenesis; a higher capacity to tolerate AA imbalances and antagonism; a more limited ability to synthesize arginine and taurine from glutamine/proline and cysteine, respectively; and a very limited ability to generate polyunsaturated fatty acids (PUFAs) from respective substrates. Unlike dogs, cats cannot convert either β-carotene into vitamin A or tryptophan into niacin. Dogs can thrive on one large meal daily and select high-fat over low-fat diets, whereas cats eat more frequently during light and dark periods and select high-protein over low-protein diets. There are increasing concerns over the health of skin, hair, bone, and joints (specialized connective tissues containing large amounts of collagen and/or keratin); sarcopenia (age-related losses of skeletal-muscle mass and function); and cognitive function in dogs and cats. Sufficient intakes of proteinogenic AAs and taurine along with vitamins, minerals, and PUFAs are crucial for the normal structures of the skin, hair, bone, and joints, while mitigating sarcopenia and cognitive dysfunction. Although pet owners may have different perceptions about the feeding and management practice of their dogs and cats, the health and well-being of the companion animals critically depend on safe, balanced, and nutritive foods. The new knowledge covered in this volume of Adv Exp Med Biol is essential to guide the formulation of pet foods to improve the growth, development, brain function, reproduction, lactation, and health of the companion animals.

Ehlers-Danlos syndrome in the practice of an otorhinolaryngologist: Clinical observation and literature review

The presented own clinical observation showed that functional dysphonia can be one of the clinical manifestations of EhlersDanlo syndrome: it is the deep layer of the own plate of the vocal fold, containing a large amount of collagen, that is most susceptible to changes in this pathology. The patient of the vocal voice for many years: a picture of hypotonic dysphonia was revealed during video pharyngostroboscopy – gaping of the laryngeal ventricles, non-closure of the vocal folds throughout by 1.5–2 mm. Acoustic analysis of the voice showed a decrease and instability in the amplitude of the pitch frequency, a narrowing of the dynamic range, a decrease in the intensity of the voice in the area of individual tones of the transient register, an increase in the level of noise components in the spectrum. The patient underwent a course of neuromuscular electrophonopedic stimulation No. 12 in combination with taking B vitamins for three weeks; after that, an increase in voice endurance was subjectively noted, however, according to the results of phonetography, spectrography and videolaryngostroboscopy, no visible positive dynamics was noted. The rheumatologist revealed hyperextension and increased traumatism of the skin, increased folding of the palms and flat feet. DNA sequencing revealed mutations in the genes and confirmed the diagnosis of Ehlers-Danlo syndrome.

Reconstruction of the alveolar–capillary barrier in vitro based on a photo‐responsive stretchable Janus membrane

AbstractThe lung is the respiratory organ of the human body, and the alveoli are the most basic functional units of the lung. Herein, a photo‐responsive stretchable Janus membrane was proposed for the reconstruction of the alveolar–capillary barrier in vitro. This Janus membrane was fabricated by photocrosslinking methylacrylamide gelatin (Gelma) hydrogel and N‐isoacrylamide (NIPAM) hydrogel mixed with graphene oxide (GO). The Gelma hydrogel containing large amounts of collagen provides a natural extracellular matrix environment for cell growth, while the temperature‐sensitive NIPAM hydrogel combined with GO gives the membrane a light‐controlled stretching property. Based on this Janus membrane, an open polydimethylsiloxane chip was established to coculture alveolar epithelial cells and vascular endothelial cells at the air–liquid interface. It was demonstrated that the alveolar epithelial cells cultured on the upper side of the Janus membrane could express epithelial cell marker protein E‐cadherin and secrete alveolar surfactant. In addition, VE‐cadherin, an endothelium‐specific protein located at the junction between endothelial cells, was also detected in vascular endothelial cells cultured on the underside of Janus membrane. The constructed lung tissue model with the dynamically stretchable Janus membrane is well‐suited for COVID‐19 infection studies and drug testing.

Type I Collagen Adsorption Behavior on the Control and Modified Surface of Polylactide Coating

Knowledge of the bio-macromolecules adsorption on polylactide (PLA) was essential to the application of PLA-based biomedical materials. This study presented the adsorption behavior of type I collagen on control (CH3-enriched) and modified (introduced COOH– and CONH2– respectively) PLA surfaces by quartz crystal microbalance with energy dissipation measurements (QCM-D) and atomic force microscopy (AFM). The results showed that the Langmuir adsorption isotherms were obtained, indicating a monomolecular layer adsorption of collagen on PLA coatings. Adsorption of collagen could reach equilibrium more quickly on the modified surfaces than on the control. Large amounts of collagen (1522.2 ng·cm−2) was assembled tightly on the COOH-enriched surface of PLA, owing to the electrostatic attracting. However it was inhibited on the CONH2-enriched surface because of its increasing hydrophilicity. A netlike structure was formed on the control and COOH-enriched surfaces, while only a few of braching fibril was found on the CONH2-enriched surface. The behaviour of protein adsorption on the surfaces with different groups might effect the next stage of cell adhesion on scaffold.

ShenKang Injection Attenuates Renal Fibrosis by Inhibiting EMT and Regulating the Wnt/β-Catenin Pathway

Shenkang Injection (SKI) is a traditional Chinese medicine injection commonly used in the clinical treatment of chronic kidney disease. Although it has been confirmed that SKI has anti-kidney fibrosis effects, the underlying mechanism remains unclear. To investigate the effects of SKI on epithelial-mesenchymal transition (EMT) and Wnt/β-catenin pathway and explore its potential anti-fibrosis mechanism. A unilateral ureteral obstruction (UUO) model was induced by ligating the left ureter of male SD rats. A total of 24 rats were randomly divided into the following four groups: sham group, model group, SKI group, and benazepril group. The rats in each group were treated for 28 days, and renal function was evaluated by blood urea nitrogen (BUN) and serum creatinine (Scr). The degree of renal fibrosis was assessed by hematoxylin and eosin (HE) and Masson staining. Extracellular matrix (ECM) deposition was evaluated by immunohistochemistry. Real-time fluorescent quantitative PCR (RT-qPCR) and western blotting were used to detect the expression of genes and proteins in the Wnt/β-catenin signaling pathway. Further studies were performed in vitro using HK-2 cells treated with TGF-β1. At 28 days postoperation, the levels of BUN and Scr expression were significantly increased in the UUO group. SKI and benazepril reduced the levels of BUN and Scr, which displayed protective renal effects. Pathological staining showed that compared with the sham operation group, the renal parenchymal structure was severely damaged, the number of glomeruli was reduced, and a large amount of collagen was deposited in the kidney tissue of the UUO group. SKI treatment reduced morphological changes. Immunohistochemistry showed that compared with the sham operation group, the content of collagen I and FN in the kidney tissue of the UUO group were significantly increased, whereas the SKI content was decreased. In addition, compared with the UUO group, the levels of Wnt1, active β-catenin, Snail1, and PAI-1 expression were reduced in the SKI group, suggesting that SKI may reduce renal fibrosis by mediating the Wnt/β-catenin pathway. Further in vitro studies showed that collagen I, FN, and α-SMA levels in HK-2 cells were significantly increased following stimulation with TGF-β1. SKI could significantly reduce the expression of collagen I, FN, and α-SMA. A scratch test showed that SKI could reduce HK-2 migration. In addition, by stimulating TGF-β1, the levels of Wnt1, active β-catenin, snail1, and PAI-1 were significantly upregulated. SKI treatment could inhibit the activity of the Wnt/β-catenin signaling pathway in HK-2 cells. SKI improves kidney function by inhibiting renal fibrosis. The anti-fibrotic effects may be mediated by regulation of the Wnt/β-catenin pathway and EMT inhibition.

Rapid fabrication of tendon-like collagen gel via simultaneous fibre alignment and intermolecular cross-linking under mechanical loading

Artificial tissue replacement is a promising strategy for better healing outcomes for tendon and ligament injuries, due to the very limited self-regeneration capacity of these tissues in mammals, including humans. Because clinically available synthetic and biological scaffolds for tendon repair have performed more poorly than autografts, both biological and mechanical compatibility need to be improved. Here we propose a rapid fabrication method for tendon-like structure from collagen hydrogel, simultaneously achieving collagen fibre alignment and intermolecular cross-linking. Collagen gel, 24 h after polymerization, was subjected to mechanical loading in the presence of the chemical cross-linker, genipin, for 24 or 48 h. Mechanical loading during gel incubation oriented collagen fibres in the loading direction and made chemical cross-linking highly effective in a loading magnitude-dependent manner. Gel incubated with 4 g loading in the presence of genipin for 48 h possessed tensile strength of 4 MPa and tangent modulus of 60 MPa, respectively, which could fulfill the minimum biomechanical requirement for artificial tendon. Although mechanical properties of gels fabricated using the present method can be improved by using a larger amount of collagen in the starting material and through optimisation of mechanical loading and cross-linking, the method is a simple and effective for producing highly aligned collagen fibrils with excellent mechanical properties.

Inhibitory Effect of Topical Cartilage Acellular Matrix Suspension Treatment on Neovascularization in a Rabbit Corneal Model.

The extracellular matrix (ECM) of articular cartilage has an inhibitory effect on vascularization, yet clinical utilization has been technically challenging. In this study, we aimed to fabricate a biologically functional ECM powder suspension from porcine articular cartilage that inhibits neovascularization (NV). The digested-cartilage acellular matrix (dg-CAM) was prepared by sequential processes of decellularization, enzymatic digestion and pulverization. Physicochemical properties of dg-CAM were compared with that of native cartilage tissue (NCT). Cellular interactions between human umbilical vein endothelial cells (HUVECs) and dg-CAM was evaluated with proliferation, migration and tube formation assays compared with that of type I collagen (COL) and bevacizumab, an anti-angiogenic drug. We then investigated the therapeutic potential of topical administration of dg-CAM suspension on the experimentally induced rabbit corneal NV model. The dg-CAM released a significantly larger amount of soluble proteins than that of the NCT and showed an improved hydrophilic and dispersion properties. In contrast, the dg-CAM contained a large amount of collagen, glycosaminoglycans and anti-angiogenic molecules as much as the NCT. The inhibitory effect on NV of the dg-CAM was more prominent than that of COL and even comparable to that of bevacizumab in inhibiting the HUVECs. The therapeutic potential of the dg-CAM was comparable to that of bevacizumab in the rabbit corneal NV model by efficiently inhibiting neovessel formation of the injured cornea. The current study developed a dg-CAM having anti-angiogenic properties, together with water-dispersible properties suitable for topical or minimally invasive application for prevention of vessel invasion.

Biocompatibility Investigation of Hybrid Organometallic Polymers for Sub-Micron 3D Printing via Laser Two-Photon Polymerisation.

Hybrid organometallic polymers are a class of functional materials which can be used to produce structures with sub-micron features via laser two-photon polymerisation. Previous studies demonstrated the relative biocompatibility of Al and Zr containing hybrid organometallic polymers in vitro. However, a deeper understanding of their effects on intracellular processes is needed if a tissue engineering strategy based on these materials is to be envisioned. Herein, primary rat myogenic cells were cultured on spin-coated Al and Zr containing polymer surfaces to investigate how each material affects the viability, adhesion strength, adhesion-associated protein expression, rate of cellular metabolism and collagen secretion. We found that the investigated surfaces supported cellular growth to full confluency. A subsequent MTT assay showed that glass and Zr surfaces led to higher rates of metabolism than did the Al surfaces. A viability assay revealed that all surfaces supported comparable levels of cell viability. Cellular adhesion strength assessment showed an insignificantly stronger relative adhesion after 4 h of culture than after 24 h. The largest amount of collagen was secreted by cells grown on the Al-containing surface. In conclusion, the materials were found to be biocompatible in vitro and have potential for bioengineering applications.

Clinical effect of nano-fat mixed granule fat transplantation in the treatment of cicatricial facial depression and atrophy and the related experimental mechanism

Objective: To study the clinical effect of nano-fat mixed granule fat transplantation in the treatment of cicatricial facial depression and atrophy, and to explore the related experimental mechanism. Methods: (1) From January 2012 to April 2018, 105 patients conforming to the inclusion criteria, with cicatricial facial depression and atrophy deformity who needed facial fat transplantation, were admitted to our unit. Their medical records were analyzed retrospectively. According to the patients' wishes, 54 patients (12 males and 42 females) aged 10-59 years received traditional transplantation of pure autologous granule fat collected from abdomen/thigh and were included in simple transplantation group, while the other 51 patients (14 males and 37 females) aged 7-63 years received transplantation of autologous nano-fat mixed granule fat collected from abdomen/thigh and were included in mixed transplantation group. The treatment satisfaction of patients 3 and 6 months after operation was assessed by the facial fullness, symmetry, scar, and complications using self-made scales and photo data before and after operation. Six months after operation, the patients were assessed whether they needed to undergo a second operation, and the rate of second operation was calculated. During the second operation, the fat of patients transplanted in the first operation was collected, and the morphology of adipocytes and microangiogenesis was observed under a scanning electron microscope. (2) Adipose-derived stem cells (ADSCs) were isolated and cultured from abdominal fat of a 4-week-old male Sprague-Dawley (SD) rat. The 5th passage of cells were selected to observe cell morphology after cultured for 14 days, observe expression of vimentin and cytokeratin-18 by immunofluorescence method, identify osteogenic and adipogenic differentiation, and detect rates of CD29 and CD44 positive cells by flow cytometer (n=3). Eighteen 4-week-old male SD rats were divided into ADSCs transplantation group, simple scar group, and blank control group according to the random number table, with 6 rats in each group. Rats in ADSCs transplantation group and simple scar group were subcutaneously injected with 1 mL bleomycin which was dissolved in phosphate buffered saline (PBS) with a mass concentration of 1 mg/mL at the back to establish scar models. After 3 hours, rats in ADSCs transplantation group were injected with 1×10(6) ADSCs suspended in 0.1 mL PBS at the same injection site, while rats in simple scar group were injected with 0.1 mL PBS. Rats in blank control group were injected with the same doses of PBS in the same place at the same two time points mentioned above. After continuous injection for 28 days in each group, the full-thickness skin tissue of the injected area of all rats was collected to observe the collagen fibers by Masson staining and expressions of α-smooth muscle actin (α-SMA) and transforming growth factor β(1) (TGF-β(1)) by immunohistochemistry, and the positive cells were counted. Data were processed with Mann-Whitney U test, χ(2) test, one-way analysis of variance, and least significant difference test. Results: (1) Compared with the preoperative condition, the facial fullness and symmetry of patients in simple transplantation group were better in 3 months after operation, with scar color closer to the surrounding skin, and the filling volume of patients in this group decreased in 6 months after operation as compared with that in 3 months after operation. In mixed transplantation group, the facial fullness and symmetry of patients were better in 3 and 6 months after operation as compared with the preoperative condition, with scar color and texture closer to the surrounding skin, and the filling volume in 6 months after operation was not obviously reduced as compared with that in 3 months after operation. Fat liquefaction and subcutaneous nodule formation occurred respectively in 1 patient in simple transplantation group within 3 months after operation. The treatment satisfaction of patients in mixed transplantation group was significantly higher than that in simple transplantation group in 3 and 6 months after operation (Z=-2.566, -3.084, P 0.05), all significantly less than (135±13) and (121±23) cells per 20-fold field of view of simple scar group (P<0.05). Conclusions: Compared with those of autologous simple granule fat transplantation, autologous nano-fat mixed granule fat transplantation has better filling fullness in the treatment of patients with scar facial depression and atrophy. The filling effect lasts longer, and the improvement of scar texture is more obvious. As showed in the rat scar model experiment, the mechanism may be that ADSCs inhibit the expressions of α-SMA and TGF-β(1), thus inhibiting the formation of scar.

The association between seizures and deposition of collagen in the brain in porcine Taenia solium neurocysticercosis

Neurocysticercosis caused by infection with Taenia solium is a significant cause of epilepsy and seizures in humans. The aim of this study was to assess the association between seizures and the deposition of collagen in brain tissue in pigs with T. solium neurocysticercosis. In total 78 brain tissue sections from seven pigs were examined histopathologically i.e. two pigs with epileptic seizures and T. solium cysts, four pigs without seizures but with cysts, and one non-infected control pig.Pigs with epileptic seizures had a larger amount of collagen in their brain tissue, showing as large fibrotic scars and moderate amount of collagen deposited around cysts, compared to pigs without seizures and the negative control pig. Our results indicate that collagen is likely to play a considerable part in the pathogenesis of seizures in T. solium neurocysticercosis.

Collagen peptides derived from Alaska pollock skin protect against TNFα‐induced dysfunction of tight junctions in Caco‐2 cells

Dysfunction of tight junctions in the intestinal barrier promotes enhanced antigen uptake, bacteria translocation, and induction of abnormal immune responses, which contribute to the pathogenesis of inflammatory bowel disease and necrotizing enterocolitis. Tumor necrosis factor‐α (TNFα) is a key proinflammatory cytokine regulating the function and structure of tight junctions. With their immunomodulatory actions, collagens and their derived bioactive peptides may protect against TNFα‐induced dysfunction in tight junctions. Fish skins generated during fish processing may be a valuable by‐product useful in the development of functional foods as they contain a large amount of collagen. Thus, we examined the effect of Alaska pollock skin‐derived collagen (SDC) and its 3 collagen peptides (CP) derived from tryptic hydrolysis, CP1 (MW &gt;6 kDa), CP2 (3–6 kDa), and CP3 (&lt;3 kDa), on TNFα‐induced dysfunction in tight junctions in Caco‐2 cell monolayers. After being cultured in a Transwell® system for 21 d, Caco‐2 cells were treated with or without 2 mg/mL SDC or CPs for 24 h, followed by treatment with 10 ng/mL TNFα for 24 h. TNFα impaired monolayer integrity, as reflected by a 26% reduction in trans‐epithelial electrical resistance (TEER) from 454 ± 16 to 340 ± 10 Ω·cm2 and by a 58% increase in FITC‐Dextran 4 kDa (FD‐4) transmembrane flux from 186 ± 17 to 293 ± 28 μg/mL. The pre‐treatment of SDC or CPs protected against TNFα‐induced destruction of tight junction integrity to different degrees. CP3 was the most protective, maintaining TEER at 438 ± 14 Ω·cm2 and FD‐4 flux at 195 ± 14 μg/mL, values not different from the control. The phosphorylation of myosin light chain (pMLC) mediated by myosin light chain kinase (MLCK) induces F‐actin rearrangement and disruption of tight junction assembly; TNFα treatment augmented pMLC and MLCK expression by 37 and 47%, respectively, compared to controls (P ≤0.05). SDC and CPs down‐regulated TNFα‐induced pMLC expression to levels comparable to controls, and CPs completely blocked TNFα‐induced MLCK expression. TNFα activated NFκB and ERK1/2 pathways, two key transcription factors in the regulation of tight junctions, as illustrated by increases in nuclear NFκB‐p65 content from 6.9 ± 0.8 to 10.1 ± 1.2 nmol/mg protein and in nuclear ELK‐1 content from 0.9 ± 0.1 to 1.3 ± 0.2 ng/mg protein (P ≤0.05). SDC and CPs completely inhibited their activations. TNFα decreased expression of tight junction proteins ZO‐1 by 35% from 496 ± 72 to 321 ± 42 ng/mg protein and occludin by 43% from 2.0 ± 0.2 to 1.1 ± 0.1 ng/mg protein compared to controls (P ≤0.05). Of the 4 treatments, only CP3 maintained the expression of these 2 tight junction proteins comparable to controls. In conclusion, Alaska pollock skin‐derived peptides, particularly CP3, protected against TNFα‐induced dysfunction in tight junctions via the NFκB‐ and ERK1/2‐mediated MLCK‐pMLC pathway.Support or Funding InformationNational Science Foundation China, China Scholarship Council &amp; USDA

Dexamethasone action on caudal fin regeneration of carp Cyprinus carpio (Linnaeus, 1758).

Studies have demonstrated that the prolonged use of corticoids can delay the healing process, affecting re-epithelialization, neovascularization and collagen synthesis. As the fins of teleost fish contain a large amount of collagen, the aim of the present study was to investigate the effect of dexamethasone (anti-inflammatory and glucocorticoid steroid widely used in the treatment of rheumatic diseases) during the regeneration process in the caudal fin of specimens of carp (Cyprinus carpio). For such, two glass aquaria were used - one for a group of fish treated with dexamethasone (Henrifarma) in a 20 mg/L concentration and the other for the control group. The caudal fins were amputated transversally and fish remained in their respective aquaria until regeneration occurred. Samples of regenerating fins were collected on days 1, 2, 4, 6, 8 and 10 after amputation. The fins in the control group regenerated normally and grew within the expected in time course. The fins in the group treated with dexamethasone were significantly smaller in comparison to the control group at every evaluation time. Thus, it was possible to verify that, at this concentration of dexamethasone, the regeneration of the caudal fins was delayed, but not completely inhibited. The results show that the caudal fin is a good model for histological studies on regeneration and the action of drug toxicity, but it's also of great importance the interaction with further studies for a better knowledge and understanding of all the changes in all the phases.

Human multipotent mesenchymal stem cells improve healing after collagenase tendon injury in the rat

BackgroundMesenchymal stromal cells attract much interest in tissue regeneration because of their capacity to differentiate into mesodermal origin cells, their paracrine properties and their possible use in autologous transplantations. The aim of this study was to investigate the safety and reparative potential of implanted human mesenchymal stromal cells (hMSCs), prepared under Good Manufacturing Practice (GMP) conditions utilizing human mixed platelet lysate as a culture supplement, in a collagenase Achilles tendon injury model in rats.MethodsEighty-one rats with collagenase-induced injury were divided into two groups. The first group received human mesenchymal stromal cells injected into the site of injury 3 days after lesion induction, while the second group received saline. Biomechanical testing, morphometry and semiquantitative immunohistochemistry of collagens I, II and III, versican and aggrecan, neovascularization, and hMSC survival were performed 2, 4, and 6 weeks after injury.ResultsHuman mesenchymal stromal cell-treated rats had a significantly better extracellular matrix structure and a larger amount of collagen I and collagen III. Neovascularization was also increased in hMSC-treated rats 2 and 4 weeks after tendon injury. MTCO2 (Cytochrome c oxidase subunit II) positivity confirmed the presence of hMSCs 2, 4 and 6 weeks after transplantation. Collagen II deposits and alizarin red staining for bone were found in 6 hMSC- and 2 saline-treated tendons 6 weeks after injury. The intensity of anti-versican and anti-aggrecan staining did not differ between the groups.ConclusionshMSCs can support tendon healing through better vascularization as well as through larger deposits and better organization of the extracellular matrix. The treatment procedure was found to be safe; however, cartilage and bone formation at the implantation site should be taken into account when planning subsequent in vivo and clinical trials on tendinopathy as an expected adverse event.

Pathological changes in primary cilia: A novel mechanism of graft cholangiopathy caused by prolonged cold preservation in a rat model of orthotopic liver transplantation.

To study the impairment of cholangiocyte primary cilia caused by prolonged cold preservation and its correlation with graft cholangiopathy after orthotopic liver transplantation (OLT). Subjects were 60 male Wistar rats that were divided into 2 groups: a control group (n = 30) receiving a donor liver preserved for 1 h and a study group (n = 30) receiving a donor liver preserved for 12 h. A two-cuff method was used to establish the OLT model, and the hepatic artery and bile ducts were reconstructed using stents. Samples were collected 2, 8, and 16 weeks after surgery, and 5 samples were collected from each group at each time point. Serum biochemical indicators were measured, morphological changes in intrahepatic bile ducts and cholangiocyte primary cilia were observed using an optical microscope and scanning electronic microscope, respectively, and the ciliary marker (α-tubulin) and membrane proteins (PC-1, TRPV4, and P2Y12) were detected using immunofluorescence analysis and Western blotting. In the study group, phlogocytes infiltrated around bile ducts and bile ducts proliferated markedly at 8 weeks. At 16 weeks, the biliary structures were indistinct and some bile ducts disappeared, a large amount of collagen was deposited, numerous phlogocytes infiltrated around ducts, some biliary epithelial cells (BECs) were deformed or dead, and primary cilia disappeared. In the control group, the intrahepatic bile ducts and BECs were nearly intact and the primary cilia were present. In the study group, the expression of α-tubulin, polycystin-1 (PC-1), TRPV4, and P2Y12 in bile ducts disappeared completely after 8 weeks. In the control group, expression of the marker and proteins decreased at 2 weeks and increased slightly after 8 weeks. These results suggest that the study group had dysfunctional primary cilia at the start of OLT and that this dysfunction was irreversible. In the control group, the primary cilia defects and subsequent biliary injury were temporary. Thus, prolonged cold preservation of a donor liver may cause graft cholangiopathy by altering the integrity and functions of cholangiocyte primary cilia.

Chemical Composition of Salmon Ovary Outer Membrane and Its Protein Increases Fecal Mucins Content in C57BL/6J and Type 2 Diabetic/Obese KK-Ay Mice

Salmon ovary outer membrane (SOM) is a byproduct of the salmon industry; however, the effective utilization of SOM for food materials and supplements is anticipated as the demand for fish and seafood increases worldwide. The purposes of the present study were to assess the chemical composition of SOM, the characteristics of SOM protein (SOMP), and its effects on serum and fecal biochemical parameters in mice. SOM contained high levels of crude protein (61.9 g/100 g) and crude lipid (18.9 g/100 g). The protein pattern of SOMP was different from those of fish muscle protein and roe; it was abundant in collagen, as calculated from the hydroxyproline content. In addition, SOMP exhibited lower protein digestibility during in vitro digestion analyses compared with casein. Male C57BL/6J and KK-Ay mice were fed a casein-based semi-purified diet or a diet with replacement of part of the dietary protein (50%) by SOMP for four weeks. Mice fed the diet containing SOMP showed elevated fecal nitrogen and mucins contents and reduced levels of serum liver injury markers and fecal ammonia. These results show for the first time that chemical composition of SOM, and SOMP, contain a resistant protein fraction and a large amount of collagen. Therefore, SOM is a potential source of marine collagen and functional food material for promoting the health of the liver and colon.

Penile Anatomy and Hypotheses of Erectile Function in the American Alligator (Alligator mississippiensis): Muscular Eversion and Elastic Retraction

The intromittent organs of most amniotes contain variable-volume hydrostatic skeletons that are stored in a flexible state and inflate with fluid before or during copulation. However, the penis in male crocodilians is notable because its shaft does not seem to change either its shape or bending stiffness as blood enters its vascular spaces before copulation. Here I report that crocodilians may have evolved a mechanism for penile shaft erection that does not require inflation and detumescence. Dissections of the cloaca in sexually mature male American alligators (Alligator mississippiensis) show that the cross section of the proximal shaft of the alligator penis contains dense collagenous tissues that do not significantly change shape when fluid is added to the central vascular space. The large amount of collagen in the wall and central space of the alligator penis stiffen the structure so it can be simply everted for copulation and rapidly retracted at its completion. Because no muscles insert directly onto the penis, eversion and retraction must be produced indirectly. My results suggest that the contraction of paired levator cloacae muscles around the anterior end of the cloaca rotates the penis out of the cloacal opening and strains the ligamentum rami that connect the base of the penis to the ischia. When the cloacal muscles relax, the elastic recoil of the ligamentum rami can return the penis to its original position inside the cloaca.

Osteoblasts responses to three‐dimensional nanofibrous gelatin scaffolds

The development of suitable scaffolds for bone tissue engineering requires an in-depth understanding of the interactions between osteoblasts and scaffolding biomaterials. Although there have been a large amount of knowledge accumulated on the cell-material interactions on two-dimensional (2D) planar substrates, our understanding of how osteoblasts respond to a biomimetic nanostructured three-dimensional (3D) scaffold is very limited. In this work, we developed an approach to use confocal microscopy as an effective tool for visualizing, analyzing, and quantifying osteoblast-matrix interactions and bone tissue formation on 3D nanofibrous gelatin scaffolds (3D-NF-GS). Integrin β1, phosphor-paxillin, and vinculin were used to detect osteoblasts responses to the nanofibrous architecture of 3D-NF-GS. Unlike osteoblasts cultured on 2D substrates, osteoblasts seeded on 3D-NF-GS showed less focal adhesions for phospho-paxillin and vinculin, and the integrin β1 was difficult to detect after the first 5 days. Bone sialoprotein (BSP) expression on the 3D-NF-GS was present mainly in the cell cytoplasm at 5 days and inside secretory vesicles at 2 weeks, whereas most of the BSP on the 2D gelatin substrates was concentrated either in cell interface toward the periphery or at focal adhesion sites. Confocal images showed that osteoblasts were able to migrate throughout the 3D matrix within 5 days. By 14 days, osteoblasts were organized as nodular aggregations inside the scaffold pores and a large amount of collagen and other cell secretions covered and remodeled the surfaces of the 3D-NF-GS. These nodules were mineralized and were uniformly distributed inside the entire 3D-NF-GS after being cultured for 2 weeks. Taken together, these results give insight into osteoblast-matrix interactions in biomimetic nanofibrous 3D scaffolds and will guide the development of optimal scaffolds for bone tissue engineering.