Molecular characterization and pathological identification of a novel strain of delta papillomavirus-4 (bovine papillomavirus-2) in Egypt.

BACKGROUND AND AIM: Bovine papillomaviruses (BPV) are a heterogeneous group of oncoviruses, distributed globally, which produce major economic losses. In the current study, we compared the results of different diagnostic approaches and compared the strains identified in this study with previously characterized strains at local and international levels. MATERIALS AND METHODS: Samples of skin warts were collected from five bovines with generalized papillomatosis from two Egyptian provinces, Menya and Ismailia, in 2020. Electron microscopy, molecular characterization, histopathological, and immunohistochemical examination were performed. RESULTS: BPV was detected using electron microscopy in the collected samples. Using molecular characterization, BPV-2 was successfully identified for 1st time in Egypt. The strain has 99.6% identity with the BPV-2 reference strains obtained from GenBank. These results were supported by histopathology and immunohistochemistry examination. Partial nucleotide sequences of the L1 gene were submitted to GenBank with accession numbers MW289843 and MW289844. CONCLUSION: BPV-2 was reported for 1st time in the current study. The strain was identified grossly, microscopically, and pathologically and confirmed using molecular approaches. All results were consistent. The sequence analysis revealed that this strain has high sequence similarity to the reference Deltapapillomavirus-4, BPV-2 strains from Brazil and China.

Diagnosis of naturally occurring lumpy skin disease virus infection in cattle using virological, molecular, and immunohistopathological assays.

BACKGROUND AND AIM: Lumpy skin disease (LSD) is a contagious viral disease that has great economic losses among Egyptian breeding flocks. The present study was designed to compare the results of different diagnostic approaches used for the diagnosis of LSD virus (LSDV). MATERIALS AND METHODS: A total of 73 skin nodule samples were collected from suspected infected cattle with LSDV from some Egyptian governorates during 2019 and 2020. Trials for virus isolation (VI) and identification on embryonated chicken eggs (ECEs) were conducted. Molecular detection, histopathological, and immunohistochemical examination were also conducted. RESULTS: The virus was isolated into ECEs, and 58 samples of 73 were positive and gave a characteristic pock lesion on the chorioallantoic membrane. Twenty-two representative nodular skin specimens of the 58 positive samples were selected to be used for molecular, histopathological, and immunohistochemistry (IHC) diagnosis. Conventional polymerase chain reaction succeeded in detecting LSDV DNA in all tested 22 skin nodule samples. Histological examination of skins of different cases revealed various alterations depending on the stage of infection. IHC was used as a confirmatory test for detecting LSDV antigen in the tissues of the skin nodules of infected cattle using specific anti-LSDV antibodies. Lumpy skin viral antigen was detected within the cytoplasm of the epidermal basal cells layer and prickle cell and within the cytoplasm of the hair follicles' epithelial outer and inner roots. CONCLUSION: This study confirmed the prevalence of LSDV infection in different Egyptian governorates during 2019 and 2020. In addition, histopathology and IHC could be potential methods to confirm Lumpy skin disease infection besidesVI and molecular detection.

Proficiency of Carboxymethylcellulose as a Cryoprotectant. Clinical and Histological Evaluation of Cryopreserved Heterogenous Mesenchymal Stem Cell-Exosomal Hydrogel on Critical Size Skin Wounds in Dogs.

Background: Fresh stem cell exosomes are usually obtained and reused in the same individual. It cannot be kept viable for a long period of time regardless of the lengthy preparation time. Freezing is typically used to preserve the viability of perishable materials and increase their lifetime. Regrettably, normal freezing of biomaterials leads to cell damage. Therefore, a cryoprotectant can save the cells from the conventional cryodamage. Sodium carboxymethylcellulose (NA-CMC) is a powdery substance that is used to manufacture bio-safe hydrofilm gels because of its high viscosity, cytocompatibility, and nonallergenic nature. Materials and Methods: Sterile CMC hydrogel was prepared, part of which was loaded with exosomal solution derived from MSCs. The gel was kept at -20°C for preservation. Two bilateral full-thickness circular skin wounds of 2-cm diameter were created on the back of experimental dogs. The wounds were at least 2.5 cm apart. Treatment started 24 hours after wound creation. Group I received CMC gel solely, whereas group II received frozen CMC exosomal gel. The gel was applied 4 times, a single application per day with 1- day interval. Results: Clinically, the frozen exosomal gel significantly promoted wound healing with no scaring. Histologically, enhanced dermal fibroblasts and organized collagen deposition were seen in the treated group. Conclusion: CMC proved to be an efficient cryoprotectant and a suitable vehicle for exosomes. Deep freezing was proven to conserve the viability, extended the preservation, and facilitated the usage of exosomal gel. This technique of preserved cell-free therapy is inexpensive, time-saving, and proficient and seems suitable for treating cutaneous wounds.

Pressure-induced left ventricular hypertrophy in canine model of aortic stenosis using nylon tie

The aim of this study was to develop an experimentally-induced canine model of left ventricular hypertrophy through banding of the ascending aorta using nylon ties. Seven clinically normal dogs free of cardiovascular disease were used. Nylon tie was used in banding the mid-ascending aorta. Clinical, radiographic and echocardiographic evaluations were done at 1.5, 3 and 6 months. Dogs were euthanized at 6 months for post mortem and histopathological evaluation. Clinically, dogs did not exhibit any signs of cardiovascular disease at 1.5 or 3 months, while at 6 months two dogs (28.6 %) exhibited mild weight loss, exercise intolerance and heart murmurs. Radiographic evaluation revealed significant increase in cardiac size only at 6 months based on measurement of the cardiothoracic area evaluation. Echocardiography revealed increased left ventricular wall thickness starting from 1.5 month, although this increase was statistically significant at 3 and 6 months (p > 0.05). Left ventricular hypertrophy was confirmed by post mortem examination. Histopathological sections of left ventricle in all dogs demonstrated myocyte hypertrophy and interstitial fibrosis. This model simulates the naturally occurring ventricular hypertrophy using a rapid and economic technique. Such models are required to understand pathogenesis of heart disease and to develop effective treatment strategy.

Histological Evaluation of Experimentally Induced Critical Size Defect Skin Wounds Using Exosomal Solution of Mesenchymal Stem Cells Derived Microvesicles.

BACKGROUND AND OBJECTIVES: The present study investigated whether MSCs derived microvesicles (MVs) or (Exosomes) can exert therapeutic effects on an experimental model of cutaneous injury and explored the underlying involving mechanisms. METHODS AND RESULTS: Three bilateral full thickness circular wounds were created on the back of two groups of dogs using 2-cm dermal punch. The wounds were at least 2.5 cm apart. Saline was subcutaneously injected in 4 places around each wound area in group-I (control), whereas an equal volume of exosomal solution of MSCs derived MVs was similarly injected in group-II. The findings demonstrated that MSCs derived MVs had significantly promoted cutaneous wound healing, collagen synthesis, and vascularization at wound sites. The application of the exosomal solution had not only promoted the generation of newly formed vessels, but also have accelerated their development and maturation leading to a faster healing process. CONCLUSIONS: MSC-Exosomes appeared to be a superior candidate for treating cutaneous wounds than their originator cells, and may represent a promising opportunity to develop a novel cell-free therapy approach that might overcome the obstacles and risks associated with the use of native or engineered stem cells transplantation therapy.

Epigallocatechin-3-Gallate: The Prospective Targeting of Cancer Stem Cells and Preventing Metastasis of Chemically-Induced Mammary Cancer in Rats.

BACKGROUND: Cancer stem cells are a subpopulation of tumor cells that are capable of self-renewal, capable of tumor recurrence and metastasis, and in addition are resistant to current cancer therapies. Epigallocatechin-3-gallate is a type of catechin found in green tea that is known for its powerful chemoprotective ability. Hence, this study aimed to investigate the effect of epigallocatechin-3-gallate on 7, 12 dimethylbenzanthracene-induced tumor metastasis, angiogenesis and cancer stem cells. MATERIALS AND METHODS: For this purpose, 3 groups of virgin femal rats with 7,12 dimethylbenzanthracene-induced mammary cancer were treated using epigallocatechin-3-gallate, paclitaxel or their combination. RESULTS: It was found that epigallocatechin-3-gallate exhibited significant chemopreventive effects and anti-cancer stem cell activity through several pathways, including a significant decrease in the size and number of tumors per rat, significant amelioration of the oxidative stress markers' alterations and significant inhibition of CD44, VEGF, Ki-67 and MMP-2 expression associated with a significantly increased expression of caspase-3. Histopathologically, therapy with epigallocatechin-3-gallate resulted in marked necrosis of the neoplastic cells and the tumor masses were mostly replaced by proliferated fibrous tissue so that histological confirmation of a previous tumor was not possible at that site. However, in the combination therapy the neoplastic cells showed marked vacuolation, haphazard arrangement and extensive nuclear pyknosis accompanied with many apoptotic bodies. Therapy with the sole paclitaxel caused variable degrees of necrosis among the neoplastic cells. Additionally, the combination of epigallocatechin-3-gallate and paclitaxel significantly enhanced the later anticancer efficacy. CONCLUSIONS: Epigallocatechin-3-gallatecould be offered as an unprecedented curative strategy to eradicate cancer.