Liver fibrosis results from excessive accumulation of extracellular matrix (ECM) proteins that distort the hepatic architecture. Progression of liver fibrosis results in cirrhosis and liver failure, and often, liver transplantation is required. The decellularized liver tissue contains different components that mimic the natural hepatic environment. We hypothesized that a decellularized liver hydrogel can be used to replace the necrotic hepatocytes and damaged ECM. Therefore, our aim in this study is to develop a therapy for treating liver fibrosis. Mice livers were decellularized and processed to form a hepatic hydrogel. We evaluated the biocompatibility and bioactivity of the hydrogel. The ability of the hydrogel to enhance the migration of hepatocytes and endothelial cells was investigated. Human hepatic stellate cell line (LX-2) activated by transforming growth factor-β1 (TGF-β1) was used as in vitro model for fibrogenesis. Then, the hydrogel was injected into the liver parenchyma of mice after the induction of liver fibrosis using thioacetamide. The resulting hydrogel maintained a complex composition, which included glycosaminoglycans, collagen, elastin, and growth factors. Hepatocytes and endothelial cells were shown to migrate toward the hydrogel in vitro. Liver hydrogel improved TGF-β1-induced LX-2 cells activation via blocking the TGF-β1/Smad pathway. The matrix was delivered successfully in vivo and enhanced the reduction of fibrosis and recovery to a nearly normal structure. In conclusion, we have demonstrated that the liver hydrogel can be utilized as an injectable biomaterial for liver tissue engineering in order to reduce the degree of fibrosis.

The development of biocompatible patches that can provide adequate mechanical properties and mimicking the physiological relevance still has enormous challenges in the field of tissue engineering. In this study, the aim is to engineer and develop tri-layered nanofiber patches to synchronous the mechanical properties and mimic the complex structure of living cardiovascular tissues. The developed patches consisting of blended silk fibrin (SF) and polyvinyl alcohol (PVA) composite as a hydrophilic middle layer. The upper and lower layers were composed of polycaprolactone polymer (PCL) and Poly (Lactic Acid) (PLA), respectively. Layer by layer of the developed patches were fabricated by electrospinning technique. The patches characteristics such as morphology, surface topography, and physiochemical, biodegradable and mechanical stability were investigated. Furthermore, a human endothelial cell line (EA. hy926) was exploited to assess the biological properties of the fabricated patches. The results show that the patches had high endothelial cells biocompatibility, mechanical elasticity, and unique nanofibers structure.

Bioengineering a functional organ holds great potential to overcome the current gap between the organ need and shortage of available organs. Whole organ decellularization allows the removal of cells from large-scale organs, leaving behind extracellular matrices containing different growth factors, structural proteins, and a vascular network with a bare surface. Successful application of decellularized tissues as transplantable organs is hampered by the inability to completely reline the vasculature by endothelial cells (ECs), leading to blood coagulation, loss of vascular patency, and subsequent death of reseeded cells. Therefore, an intact, continuous layer of endothelium is essential to maintain proper functioning of the vascular system, which includes the transfer of nutrients to surrounding tissues and protecting other types of cells from shear stress. Here, we aimed to summarize the available cell sources that can be used for reendothelialization in addition to different trials performed by researchers to reconstruct vascularization of decellularized solid organs. Additionally, different techniques for enhancing reendothelialization and the methods used for evaluating reendothelialization efficiency along with the future prospective applications of this field are discussed. STATEMENT OF SIGNIFICANCE: Despite the great progress in whole organ decellularization, reconstruction of vasculature within the engineered constructs is still a major roadblock. Reconstructed endothelium acts as a multifunctional barrier of vessels, which can reduce thrombosis and help delivering of oxygen and nutrients throughout the whole organ. Successful reendothelialization can be achieved through reseeding of appropriate cell types on the naked vasculature with or without modification of its surface. Here, we present the current research milestones that so far established to reconstruct the vascular network in addition to the methods used for evaluating the efficiency of reendotheilization. Thus, this review is quite significant and will aid the researchers to know where we stand toward biofabricating a transplantable organ from decellularizd extracellular matrix.

Background and Aim: Congenital anomalies of the urinary system are common affections in ruminants. Dilatation of the pelvic urethra is one of these affections in which the pelvic urethra dilated than normal diameter. This study aimed to explain the diagnosis and surgical treatment of urethral dilatation in cattle calves. Materials and Methods: Twenty-three bull calves (2-7 months old) were presented with a history of stranguria, tenesmus, and straining. Diagnosis of urethral dilatation was relied on the case history and clinical examination and was confirmed using survey and contrast radiography, ultrasonography, and biochemical tests. Treatment was done by urethrostomy under the effect of local infiltration analgesia. Results: Physical examination revealed the presence of an oval, firm, and painless swelling at the perineal region, starting just below the anus and extended to the base of the scrotum. The owners reported that the initial swelling size and severity of symptoms increased with the progress of animal age. Biochemical findings revealed non-significant changes in blood urea nitrogen and creatinine levels. Radiographic findings showed an oval radiopaque mass. However, a well-demarcated structure with acoustic enhancement was detected on ultrasonographic examination. Urethrostomy resulted in a successful outcome of all cases. Conclusion: Depending on these findings, ultrasonography is the most reliable diagnostic tool and urethrostomy is the intervention of choice with acceptable results for diagnosis and treatment of urethral dilatation in cattle calves, respectively.

Background and Aim: Congenital anomalies of the urinary system are common affections in ruminants. Dilatation of the pelvic urethra is one of these affections in which the pelvic urethra dilated than normal diameter. This study aimed to explain the diagnosis and surgical treatment of urethral dilatation in cattle calves. Materials and Methods: Twenty-three bull calves (2-7 months old) were presented with a history of stranguria, tenesmus, and straining. Diagnosis of urethral dilatation was relied on the case history and clinical examination and was confirmed using survey and contrast radiography, ultrasonography, and biochemical tests. Treatment was done by urethrostomy under the effect of local infiltration analgesia. Results: Physical examination revealed the presence of an oval, firm, and painless swelling at the perineal region, starting just below the anus and extended to the base of the scrotum. The owners reported that the initial swelling size and severity of symptoms increased with the progress of animal age. Biochemical findings revealed non-significant changes in blood urea nitrogen and creatinine levels. Radiographic findings showed an oval radiopaque mass. However, a well-demarcated structure with acoustic enhancement was detected on ultrasonographic examination. Urethrostomy resulted in a successful outcome of all cases. Conclusion: Depending on these findings, ultrasonography is the most reliable diagnostic tool and urethrostomy is the intervention of choice with acceptable results for diagnosis and treatment of urethral dilatation in cattle calves, respectively.

An 11-year-old female mixed-breed dog admitted due to anorexia and vomiting. Radiography showed 7.6-mm uroliths in the right proximal ureter and an enlarged kidney. Type 1 emphysematous pyelonephritis (EPN) was diagnosed using computed tomography (CT) in the awake dog. Right ureteronephrectomy was performed, and Escherichia coli was isolated. The stone was consisted of 80% calcium oxalate. At the 6-month follow-up, no complications were observed. This is the first report of EPN caused by calcium oxalate in a dog. In addition, we suggest performing CT in weak animals to diagnose EPN without anesthesia.

The trunk kidney of grass carp mainly consisted of renal tubules with a few interstitial hematopoietic tissues. The component structure of fish nephron markedly varies between different species of fish. The nephron of grass carp consisted of morphologically distinct segments; renal corpuscles, neck segment, proximal, intermediate, distal, and collecting tubules. The glomerulus of renal corpuscles mainly composed of mesangial cells and well-developed podocytes that extended their processes to the endothelium of glomerular capillaries forming the filtration barrier. The podocytes expressed both α-SMA and the transforming growth factor gene, TGF-β. The proximal convoluted tubules (PCTs) expressed α-SMA iNOS2, and TGF-β. The cytoplasmof PCT was rich in mitochondria and rER, in addition to the presence of well-developed basolateral tubular system and apical brush borders. Collecting tubules distributed throughout the kidney and lined by principal and flask cells. The interstitial hemopoietic tissues contained iNOS2-positive polymorphic granulocytes, CD3-positive T lymphocytes, rodlet cells, dendritic cells, macrophages, melanomacrophage centers, and telocytes. This study described for the first time the cellular components of the nephron and its associated hemopoietic tissues that can act as a basis for studying the structural changes that may occur in the kidney of grass carp during water salinitiy, environmental, or experimental conditions.

Teleosts exhibit enormous heterogeneity in brain morphology, especially in the patterns of the organization of cerebellum. The cerebellum of a red-tail shark that we analyzed was well-developed and included three main divisions: the valvula cerebelli, the corpus cerebelli, and the vestibulolateral lobe. Characteristically, the cerebellar cortex contained three well-distinct layers: an outer molecular, intermediate ganglionic, and inner granular layer. The ganglionic layer possessed irregularly arranged Purkinje cells and eurydendroid cells that extended their processes into the molecular layer. Both Purkinje cells and eurydendroid cells showed immunoreactivity for iNOS2. Moreover, astrocytes in the cerebellum showed the expression of glial fibrillary acidic protein. The most striking observation in the cerebellum of shark was the lack of deep cerebellar nuclei and a well-identified white matter. On the other hand, the gray substance in the spinal cord displays a characteristic pattern in its organization, in which the dorsal horns lie quite close together, giving the gray substance the shape of an inverted Y and possessing large neurons. Notably, the white matter possessed myelinated nerve fibers. The current study provides the first report on the organization of layers and neurons in the cerebellum and spinal cord of red-tail shark. This research will contribute to the neuroanatomy and evolutionary studies of the brain of Cyprinidae.

The role of retinoid acid receptor-related orphan receptor alpha (RORα) on male reproductive functions during aging is unclear. Here, we analyze the morphological changes in the testis of both young and aged RORα-deficient mice, with and without melatonin supplementation. Young mutants showed vacuolation, degeneration and pyknosis of spermatogenic epithelium and Sertoli cells. Aged mutants showed atrophy of the seminiferous tubules and absence of mitotic spermatogenic cells. Absence of sperms in many tubules, loss of acrosomal cap, vacuolation and hypertrophy of Sertoli cells were detected in aged mice, with a significant reduction in the number of seminiferous tubules and a significant increase in the number of Leydig cells and telocytes. Repair in seminiferous tubules and interstitial tissues with enhancement of spermatogenesis was observed in melatonin-treated aged mice. Young mutants overexpressed VEGF that was weaker in aged animals and observed only in the spermatocytes, while melatonin increased VEGF expression in spermatocytes and spermatids. Caspase 3 increased in both young and aged mutant mice in all seminiferous tubules and interstitium; caspase 3 immunostaining in seminiferous tubules, however, showed a normal pattern of apoptosis with melatonin supplementation. The present study reports that age-dependent testicular changes in RORα mutant mice were recovered by melatonin treatment.

Specific features of the immunohistochemical and ultrastructural organization of the hemopoietic head-kidney (HK) in adult Ctenopharyngodon idella (Valenciennes, 1844) were investigated using light and transmission electron microscopy. The HK of grass carp possessed all developmental stages of leucocytes and erythrocytes, as well as dendritic cells and epithelial reticular cells. The rodlet cells were expressed α-smooth muscle actin (SMA). In addition, macrophages were the most numerous cells in the HK, which aggregated into structures called melanomacrophage centers (MMCs). On contrary, the chromaffin and interrenal cells (ICs) were mixed and organized into large anastomosing cords, which lined the posterior cardinal veins of the HK, and associated with many blood capillaries. The ICs displayed the characteristic features of steroid-producing cells. Three types of chromaffin cells: adrenaline, noradrenaline, and small granule- containing cells were observed in the HK. Glial fibrillary acidic protein (GFAP)-positive sustentacular cells were marked among the chromaffin cells. Hemopoietic cells, immune cells, MMCs, rodlet cells, in addition to three types of chromaffin cells and one type of interrenal cells in the HK were correlated with the functional significance of the fish concerned.