Tracking the therapeutic efficacy of a ketone mono ester and β-hydroxybutyrate for ulcerative colitis in rats: New perspectives

Ulcerative colitis (UC) is an inflammatory condition that affects the colon's lining and increases the risk of colon cancer. Despite ongoing research, there is no identified cure for UC. The recognition of NLRP3 inflammasome activation in the pathogenesis of UC has gained widespread acceptance. Notably, the ketone body β-hydroxybutyrate inhibits NLRP3 demonstrating its anti-inflammatory properties. Additionally, BD-AcAc 2 is ketone mono ester that increases β-hydroxybutyrate blood levels. It has the potential to address the constraints associated with exogenous β-hydroxybutyrate as a therapeutic agent, including issues related to stability and short duration of action. However, the effects of β-hydroxybutyrate and BD-AcAc 2 on colitis have not been fully investigated. This study found that while both exogenous β-hydroxybutyrate and BD-AcAc 2 produced the same levels of plasma β-hydroxybutyrate, BD-AcAc 2 demonstrated superior effectiveness in mitigating dextran sodium sulfate-induced UC in rats. The mechanism of action involves modulating the NF-κB signaling, inhibiting the NLRP3 inflammasome, regulating antioxidant capacity, controlling tight junction protein expression and a potential to inhibit apoptosis and pyroptosis. Certainly, BD-AcAc 2's anti-inflammatory effects require more than just increasing plasma β-hydroxybutyrate levels and other factors contribute to its efficacy. Local ketone concentrations in the gastrointestinal tract, as well as the combined effect of specific ketone bodies, are likely to have contributed to the stronger protective effect observed with ketone mono ester ingestion in our experiment. As a result, further investigations are necessary to fully understand the mechanisms of BD-AcAc 2 and optimize its use.

Smart/stimuli-responsive chitosan/gelatin and other polymeric macromolecules natural hydrogels vs. synthetic hydrogels systems for brain tissue engineering: A state-of-the-art review

Currently, there are no viable curative treatments that can enhance the central nervous system's (CNS) recovery from trauma or illness. Bioengineered injectable smart/stimuli-responsive hydrogels (SSRHs) that mirror the intricacy of the CNS milieu and architecture have been suggested as a way to get around these restrictions in combination with medication and cell therapy. Additionally, the right biophysical and pharmacological stimuli are required to boost meaningful CNS regeneration. Recent research has focused heavily on developing SSRHs as cutting-edge delivery systems that can direct the regeneration of brain tissue. In the present article, we have discussed the pathology of brain injuries, and the applicable strategies employed to regenerate the brain tissues. Moreover, the most promising SSRHs for neural tissue engineering (TE) including alginate (Alg.), hyaluronic acid (HA), chitosan (CH), gelatin, and collagen are used in natural polymer-based hydrogels and thoroughly discussed in this review. The ability of these hydrogels to distribute bioactive substances or cells in response to internal and external stimuli is highlighted with particular attention. In addition, this article provides a summary of the most cutting-edge techniques for CNS recovery employing SSRHs for several neurodegenerative diseases.

Unraveling the role of miRNAs in the diagnosis, progression, and drug resistance of oral cancer

Oral cancer (OC) is a widely observed neoplasm on a global scale. Over time, there has been an increase in both its fatality and incidence rates. Oral cancer metastasis is a complex process that involves a number of cellular mechanisms, including invasion, migration, proliferation, and escaping from malignant tissue through either lymphatic or vascular channels. MicroRNAs (miRNAs) are a crucial class of short non-coding RNAs recognized as significant modulators of diverse cellular processes and exert a pivotal influence on the carcinogenesis pathway, functioning either as tumor suppressors or as oncogenes. It has been shown that microRNAs (miRNAs) have a role in metastasis at several stages, including epithelial-mesenchymal transition, migration, invasion, and colonization. This regulation is achieved by targeting key genes involved in these pathways by miRNAs. This paper aims to give a contemporary analysis of OC, focusing on its molecular genetics. The current literature and emerging advancements in miRNA dysregulation in OC are thoroughly examined. This project would advance OC diagnosis, prognosis, therapy, and therapeutic implications.

Unraveling the role of miRNAs in the diagnosis, progression, and therapeutic intervention of Parkinson's disease

Parkinson's disease (PD) is a debilitating neurological disorder characterized by the impairment of the motor system, resulting in symptoms such as resting tremor, cogwheel rigidity, bradykinesia, difficulty with gait, and postural instability. The occurrence of striatal dopamine insufficiency can be attributed to a notable decline in dopaminergic neurons inside the substantia nigra pars compacta. Additionally, the development of Lewy bodies serves as a pathological hallmark of PD. While current therapy approaches for PD aim to preserve dopaminergic neurons or replenish dopamine levels in the brain, it is important to acknowledge that achieving complete remission of the condition remains elusive. MicroRNAs (miRNAs, miR) are a class of small, non-coding ribonucleic acids involved in regulating gene expression at the post-transcriptional level. The miRNAs play a crucial part in the underlying pathogenic mechanisms of several neurodegenerative illnesses, including PD. The aim of this review is to explore the role of miRNAs in regulating genes associated with the onset and progression of PD, investigate the potential of miRNAs as a diagnostic tool, assess the effectiveness of targeting specific miRNAs as an alternative therapeutic strategy to impede disease advancement, and discuss the utilization of newly developed nanoparticles for delivering miRNAs as neurodegenerative therapies.

Adipose Stem Cell-Seeded Decellularized Porcine Pericardium: A Promising Functional Biomaterial to Synergistically Restore the Cardiac Functions Post-Myocardial Infarction

Myocardial infarction (MI) is a serious cardiovascular disease as the leading cause of death globally. Hence, reconstruction of the cardiac tissue comes at the forefront of strategies adopted to restore heart functions following MI. In this investigation, we studied the capacity of rat adipose-derived mesenchymal stem cells (r-AdMSCs) and decellularized porcine pericardium (DPP) to restore heart functions in MI animals. MI was induced in four different groups, three of which were treated either using DPP (MI-DPP group), stem cells (MI-SC group), or both (MI-SC/DPP group). Cardiac functions of these groups and the Sham group were evaluated using echocardiography, the intraventricular pressure gradient (IVPG) on weeks 2 and 4, and intraventricular hemodynamics on week 4. On day 31, the animals were euthanized for histological analysis. Echocardiographic, IVPG and hemodynamic findings indicated that the three treatment strategies shared effectively in the regeneration process. However, the MI-SC/DPP group had a unique synergistic ability to restore heart functions superior to the other treatment protocols. Histology showed that the MI-SC/DPP group presented the lowest (p < 0.05) degeneration score and fibrosis % compared to the other groups. Conclusively, stem cell-seeded DPP is a promising platform for the delivery of stem cells and restoration of heart functions post-MI.

Advances and prospects of platelet-rich plasma therapy in veterinary ophthalmology

In the recent decades, there has been a significant uptick on the use of platelet-rich plasma (PRP) as a better alternative for ophthalmologic therapies in pathologies, primarily of the ocular surface. PRP is a class of liquid platelet concentrate containing a supra-physiological concentration of platelets in a relatively small amount of plasma. Its potential to heal various tissues has piqued interest in its therapeutic application as a biomaterial in regenerative medicine. It is currently a popular therapeutic agent in plastic surgery, cardiothoracic surgery, reconstructive surgery, and even oral and maxillofacial surgery. Based on the data from in vitro and in vivo studies, it can be concluded that PRP possesses adequate therapeutic potential in ocular pathologies, especially those involving cornea. In addition, the high concentrations of growth factors (TGF-β, VEGF, EGF) present in the PRP accelerate the healing of the corneal epithelium. PRP has great therapeutic prospects in veterinary ophthalmology as a regenerative therapeutic modality. However, several variables are yet to be defined and standardized that can directly affect the efficacy of PRP application in different ophthalmic conditions. There is a shortage of research on the use of PRP in ocular surface defects compared to the number of studies and reports on the use of autologous and allogeneic serum eye drops. Therefore, a data-driven approach is required to generate consensus/guidelines for the preparation, characterization, and therapeutic use of PRP in veterinary ophthalmology. This review aims to inform readers of the latest research on PRP, including its preparation methods, physiological and biochemical properties, clinical applications in veterinary ophthalmology, and their safety and efficacy.

miRNAs orchestration of salivary gland cancer- Particular emphasis on diagnosis, progression, and drug resistance

Cancer of the salivary glands is one of the five major types of head and neck cancer. Due to radioresistance and a strong propensity for metastasis, the survival rate for nonresectable malignant tumors is dismal. Hence, more research is needed on salivary cancer's pathophysiology, particularly at the molecular level. The microRNAs (miRNAs) are a type of noncoding RNA that controls as many as 30% of all genes that code for proteins at the posttranscriptional level. Signature miRNA expression profiles have been established in several cancer types, suggesting a role for miRNAs in the incidence and progression of human malignancies. Salivary cancer tissues were shown to have significantly aberrant levels of miRNAs compared to normal salivary gland tissues, supporting the hypothesis that miRNAs play a crucial role in the carcinogenesis of salivary gland cancer (SGC). Besides, several SGC research articles reported potential biomarkers and therapeutic targets for the miRNA-based treatment of this malignancy. In this review, we will explore the regulatory impact of miRNAs on the processes underlying the molecular pathology of SGC and provide an up-to-date summary of the literature on miRNAs that impacted this malignancy. We will eventually share information about their possible use as diagnostic, prognostic, and therapeutic biomarkers in SGC.

miRNAs driving diagnosis, progression, and drug resistance in multiple myeloma

Multiple myeloma (MM) is a tumor of transformed plasma cells. It's the second most common hematologic cancer after non-Hodgkin lymphoma. MM is a complex disease with many different risk factors, including ethnicity, race, and epigenetics. The microRNAs (miRNAs) are a critical epigenetic factor in multiple myeloma, influencing key aspects such as pathogenesis, prognosis, and resistance to treatment. They have the potential to assist in disease diagnosis and modulate the resistance behavior of MM towards therapeutic regimens. These characteristics could be attributed to the modulatory effects of miRNAs on some vital pathways such as NF-KB, PI3k/AKT, and P53. This review discusses the role of miRNAs in MM with a focus on their role in disease progression, diagnosis, and therapeutic resistance.

The potential role of miRNAs in the pathogenesis of gallbladder cancer - A focus on signaling pathways interplay

microRNAs (also known as miRNAs or miRs) are a class of small non-coding RNAs that play a critical role in post-transcriptional gene regulation as negative gene regulators by binding complementary sequences in the 3'-UTR of target messenger RNAs (mRNAs) leading to translational repression and/or target degradation a wide range of genes and biological processes, including cell proliferation, invasion, migration, and apoptosis. The development and progression of cancer have been linked to the anomalous expression of miRNAs. According to recent studies, miRNAs have been found to regulate the expression of cancer-related genes through multiple signaling pathways in gallbladder cancer (GBC). Besides, miRNAs are implicated in several modulatory signaling pathways of GBC, including the Notch signaling pathway, JAK/STAT signaling pathway, protein kinase B (AKT), and Hedgehog signaling pathway. This review summarizes our current knowledge of the functions of miRNAs in the mechanisms underlying the pathogenic symptoms of GBC and illustrates their potential significance as treatment targets.

Decoding the role of miRNAs in multiple myeloma pathogenesis: A focus on signaling pathways

Multiple myeloma (MM) is a cancer of plasma cells that has been extensively studied in recent years, with researchers increasingly focusing on the role of microRNAs (miRNAs) in regulating gene expression in MM. Several non-coding RNAs have been demonstrated to regulate MM pathogenesis signaling pathways. These pathways might regulate MM development, apoptosis, progression, and therapeutic outcomes. They are Wnt/β-catenin, PI3K/Akt/mTOR, P53 and KRAS. This review highlights the impending role of miRNAs in MM signaling and their relationship with MM therapeutic interventions.

Comparison of Bovine- and Porcine-Derived Decellularized Biomaterials: Promising Platforms for Tissue Engineering Applications

Animal-derived xenogeneic biomaterials utilized in different surgeries are promising for various applications in tissue engineering. However, tissue decellularization is necessary to attain a bioactive extracellular matrix (ECM) that can be safely transplanted. The main objective of the present study is to assess the structural integrity, biocompatibility, and potential use of various acellular biomaterials for tissue engineering applications. Hence, a bovine pericardium (BP), porcine pericardium (PP), and porcine tunica vaginalis (PTV) were decellularized using a Trypsin, Triton X (TX), and sodium dodecyl sulfate (SDS) (Trypsin + TX + SDS) protocol. The results reveal effective elimination of the cellular antigens with preservation of the ECM integrity confirmed via staining and electron microscopy. The elasticity of the decellularized PP (DPP) was markedly (p < 0.0001) increased. The tensile strength of DBP, and DPP was not affected after decellularization. All decellularized tissues were biocompatible with persistent growth of the adipose stem cells over 30 days. The staining confirmed cell adherence either to the peripheries of the materials or within their matrices. Moreover, the in vivo investigation confirmed the biocompatibility and degradability of the decellularized scaffolds. Conclusively, Trypsin + TX + SDS is a successful new protocol for tissue decellularization. Moreover, decellularized pericardia and tunica vaginalis are promising scaffolds for the engineering of different tissues with higher potential for the use of DPP in cardiovascular applications and DBP and DPTV in the reconstruction of higher-stress-bearing abdominal walls.

Stimuli-responsive hydrogels: smart state of-the-art platforms for cardiac tissue engineering

Biomedicine and tissue regeneration have made significant advancements recently, positively affecting the whole healthcare spectrum. This opened the way for them to develop their applications for revitalizing damaged tissues. Thus, their functionality will be restored. Cardiac tissue engineering (CTE) using curative procedures that combine biomolecules, biomimetic scaffolds, and cells plays a critical part in this path. Stimuli-responsive hydrogels (SRHs) are excellent three-dimensional (3D) biomaterials for tissue engineering (TE) and various biomedical applications. They can mimic the intrinsic tissues' physicochemical, mechanical, and biological characteristics in a variety of ways. They also provide for 3D setup, adequate aqueous conditions, and the mechanical consistency required for cell development. Furthermore, they function as competent delivery platforms for various biomolecules. Many natural and synthetic polymers were used to fabricate these intelligent platforms with innovative enhanced features and specialized capabilities that are appropriate for CTE applications. In the present review, different strategies employed for CTE were outlined. The light was shed on the limitations of the use of conventional hydrogels in CTE. Moreover, diverse types of SRHs, their characteristics, assembly and exploitation for CTE were discussed. To summarize, recent development in the construction of SRHs increases their potential to operate as intelligent, sophisticated systems in the reconstruction of degenerated cardiac tissues.

The potential role of miRNAs in the pathogenesis of salivary gland cancer - A Focus on signaling pathways interplay

Salivary gland cancer (SGC) is immensely heterogeneous, both in terms of its physical manifestation and its aggressiveness. Developing a novel diagnostic and prognostic detection method based on the noninvasive profiling of microribonucleic acids (miRs) could be a goal for the clinical management of these specific malignancies, sparing the patients' valuable time. miRs are promising candidates as prognostic biomarkers and therapeutic targets or factors that can advance the therapy of SGC due to their ability to posttranscriptionally regulate the expression of various genes involved in cell proliferation, differentiation, cell cycle, apoptosis, invasion, and angiogenesis. Depending on their biological function, many miRs may contribute to the development of SGC. Therefore, this article serves as an accelerated study guide for SGC and the biogenesis of miRs. Here, we shall list the miRs whose function in SGC pathogenesis has recently been determined with an emphasis on their potential applications as therapeutic targets. We will also offer a synopsis of the current state of knowledge about oncogenic and tumor suppressor miRs in relation to SGC.

The interplay of signaling pathways and miRNAs in the pathogenesis and targeted therapy of esophageal cancer

Globally, esophageal cancer (EC) is the 6th leading cause of cancer-related deaths and the second deadliest gastrointestinal cancer. Multiple genetic and epigenetic factors, such as microRNAs (miRNAs), influence its onset and progression. miRNAs are short nucleic acid molecules that can regulate multiple cellular processes by regulating gene expression. Therefore, EC initiation, progression, apoptosis evasions, invasion capacity, promotion, angiogenesis, and epithelial-mesenchymal transition (EMT) enhancement are associated with miRNA expression dysregulation. Wnt/-catenin signaling, Mammalian target of rapamycin (mTOR)/P-gp, phosphoinositide-3-kinase (PI3K)/AKT/c-Myc, epidermal growth factor receptor (EGFR), and transforming growth factor (TGF)-β signaling are crucial pathways in EC that are controlled by miRNAs. This review was conducted to provide an up-to-date assessment of the role of microRNAs in EC pathogenesis and their modulatory effects on responses to various EC treatment modalities.

Impact of the mother's gut microbiota on infant microbiome and brain development

The link between the gut microbiome and health has recently garnered considerable interest in its employment for medicinal purposes. Since the early microbiota exhibits more flexibility compared to that of adults, there is a considerable possibility that altering it will have significant consequences on human development. Like genetics, the human microbiota can be passed from mother to child. This provides information on early microbiota acquisition, future development, and prospective chances for intervention. The succession and acquisition of early-life microbiota, modifications of the maternal microbiota during pregnancy, delivery, and infancy, and new efforts to understand maternal-infant microbiota transmission are discussed in this article. We also examine the shaping of mother-to-infant microbial transmission, and we then explore possible paths for future research to advance our knowledge in this area.

Impact of Adipose Tissue Depot Harvesting Site on the Multilineage Induction Capacity of Male Rat Adipose-Derived Mesenchymal Stem Cells: An In Vitro Study

Recently, substantial attention has been paid toward adipose-derived mesenchymal stem cells (AdMSCs) as a potential therapy in tissue engineering and regenerative medicine applications. Rat AdMSCs (r-AdMSCs) are frequently utilized. However, the influence of the adipose depot site on the multilineage differentiation potential of the r-AdMSCs is still ambiguous. Hence, the main objective of this study was to explore the influence of the adipose tissue harvesting location on the ability of r-AdMSCs to express the stem-cell-related markers and pluripotency genes, as well as their differentiation capacity, for the first time. Herein, we have isolated r-AdMSCs from the inguinal, epididymal, peri-renal, and back subcutaneous fats. Cells were compared in terms of their phenotype, immunophenotype, and expression of pluripotency genes using RT-PCR. Additionally, we investigated their potential for multilineage (adipogenic, osteogenic, and chondrogenic) induction using special stains confirmed by the expression of the related genes using RT-qPCR. All cells could positively express stem cell marker CD 90 and CD 105 with no significant in-between differences. However, they did not express the hematopoietic markers as CD 34 and CD 45. All cells could be induced successfully. However, epididymal and inguinal cells presented the highest capacity for adipogenic and osteogenic differentiation (21.36-fold and 11.63-fold for OPN, 29.69-fold and 26.68-fold for BMP2, and 37.67-fold and 22.35-fold for BSP, respectively, in epididymal and inguinal cells (p < 0.0001)). On the contrary, the subcutaneous cells exhibited a superior potential for chondrogenesis over the other sites (8.9-fold for CHM1 and 5.93-fold for ACAN, (p < 0.0001)). In conclusion, the adipose tissue harvesting site could influence the differentiation capacity of the isolated AdMSCs. To enhance the results of their employment in various regenerative cell-based therapies, it is thus vital to take the collection site selection into consideration.

miRNAs as potential game-changers in head and neck cancer: Future clinical and medicinal uses

Head and neck cancers (HNCs) are a group of heterogeneous tumors formed most frequently from epithelial cells of the larynx, lips, oropharynx, nasopharynx, and mouth. Numerous epigenetic components, including miRNAs, have been demonstrated to have an impact on HNCs characteristics like progression, angiogenesis, initiation, and resistance to therapeutic interventions. The miRNAs may control the production of numerous genes linked to HNCs pathogenesis. The roles that miRNAs play in angiogenesis, invasion, metastasis, cell cycle, proliferation, and apoptosis are responsible for this impact. The miRNAs also have an impact on crucial HNCs-related mechanistic networks like the WNT/β-catenin signaling, PTEN/Akt/mTOR pathway, TGFβ, and KRAS mutations. miRNAs may affect how the HNCs respond to treatments like radiation and chemotherapy in addition to pathophysiology. This review aims to demonstrate the relationship between miRNAs and HNCs with a particular emphasis on how miRNAs impact HNCs signaling networks.

miRNAs insights into rheumatoid arthritis: Favorable and detrimental aspects of key performers

Rheumatoid arthritis (RA) is a severe autoimmune inflammation that mostly affects the joints. It's a multifactorial disease. Its clinical picture depends on genetic and epigenetic factors such as miRNAs. The miRNAs are small noncoding molecules that are able to negatively or positively modulate their target gene expression. In RA, miRNAs are linked to its pathogenesis. They disrupt immunity balance by controlling granulocytes, triggering the release of several proinflammatory cytokines such as interleukin-6 and tumor necrosis factor-α, finally leading to synovium hyperplasia and inflammation. Besides, they also may trigger activation of some pathways as nuclear factor kappa-β disrupts the balance between osteoclast and osteoblast activity, leading to increased bone destruction. Moreover, miRNAs are also applied with efficiency in RA diagnosis and prognosis. Besides the significant association between miRNAs and RA response to treatment, they are also applied as a choice for treatment based on their effects on the immune system and inflammatory cytokines. Hence, the review aims to present an updated overview of miRNAs, their biogenesis, implications in RA pathogenesis, and finally, the role of miRNAs in RA treatment.

Intraventricular pressure gradient: a novel colour M-mode echocardiographic-derived imaging modality to assess and predict the alterations following acute myocardial infarction

Funding Acknowledgements

Type of funding sources: None.

Background

Myocardial infarction (MI), caused by partial or total interruption of myocardial blood supply, is among the leading causes of morbidity and death. It can go silent (undetected), or it can be a catastrophic occurrence with severe hemodynamic alterations and abrupt death. Hence, immediate diagnosis or even prediction of these changes is really significant. Being the gold standard technique, echocardiography is typically adopted to identify heart dysfunctions. However, it exhibits a modest aptitude to foresee these variations. Intraventricular pressure gradient (IVPG) was introduced recently as a precise colour M-mode echocardiographic (CMME)-derived diastolic function imaging modality to assess the cardiac performance. Yet, its potential to assess and anticipate the alterations post-acute MI was not explored.

Purpose

The chief goal of this work is to study the efficacy of IVPG to measure and expect the alterations of rats’ cardiac functions at early stages of MI induced by variable LAD suture occlusion sites.

Methods

Fifty-five male SD rats were operated. Three different LAD occlusion sites were adopted to induce MI. In one group, LAD was occluded at the junction between LA and LV (MI-H, n=20). The middle and low ligation sites were more distal away from the base in two distinct groups (MI-M, n=15, and MI-L, n=10). The typical thoracotomy was accomplished in sham animals without occlusion of LAD (Sham, n=10). The sham and survived MI animals were checked using conventional echocardiography and CMME-derived IVPG on days 1, 7, 14, and 21 post MI induction. Afterwards, they were euthanized after transcatheter hemodynamics recording under the effect of anesthesia. The heart sections were stained to calculate the infarction size.

Results

The MI-H animals showed the lowest survival rate (35 % vs. 66.67, and 80 % in MI-M and MI-L groups; respectively). Moreover, they presented the most serious cardiac and hemodynamic alterations. The values of mid-to-apical, mid, and apical IVPG segments were significantly (P&lt; 0.001) declined in MI-M and MI-H groups compared to sham on days 7, 14, and 21. Likewise, they presented a meaningful reduction of the total IVPG on days 14, and 21. Contrarily, the basal IVPG was markedly (P&lt; 0.0001) elevated. Despite the echocardiographic changes were firstly recorded on day 14, the variations in the IVPG were recorded on day 7. The IVPG variables were significantly (P&lt; 0.0001) correlated with the echocardiographic, the hemodynamic (LVSP, LVDP, LVEDP, +dP/dtmax, -dP/dtmin, Tau) variables, and the infarction size. Moreover, all IVPG indices could significantly predict the cardiac and hemodynamic alterations occurred in varied degrees of severity. The Bland-Altman test confirmed the reproducibility of our IVPG measures.

Conclusion

CMME-derived IVPG is a novel and promising imaging modality with superior ability than conventional echocardiography to assess and predict the alterations encountered due to acute MI.

Mutations in SARS-CoV-2: Insights on structure, variants, vaccines, and biomedical interventions

COVID-19 is a worldwide pandemic caused by SARS-coronavirus-2 (SARS-CoV-2). Less than a year after the emergence of the Covid-19 pandemic, many vaccines have arrived on the market with innovative technologies in the field of vaccinology. Based on the use of messenger RNA (mRNA) encoding the Spike SARS-Cov-2 protein or on the use of recombinant adenovirus vectors enabling the gene encoding the Spike protein to be introduced into our cells, these strategies make it possible to envisage the vaccination in a new light with tools that are more scalable than the vaccine strategies used so far. Faced with the appearance of new variants, which will gradually take precedence over the strain at the origin of the pandemic, these new strategies will allow a much faster update of vaccines to fight against these new variants, some of which may escape neutralization by vaccine antibodies. However, only a vaccination policy based on rapid and massive vaccination of the population but requiring a supply of sufficient doses could make it possible to combat the emergence of these variants. Indeed, the greater the number of infected individuals, the faster the virus multiplies, with an increased risk of the emergence of variants in these RNA viruses. This review will discuss SARS-CoV-2 pathophysiology and evolution approaches in altered transmission platforms and emphasize the different mutations and how they influence the virus characteristics. Also, this article summarizes the common vaccines and the implication of the mutations and genetic variety of SARS-CoV-2 on the COVID-19 biomedical arbitrations.

The Pivotal Role of Stem Cells in Veterinary Regenerative Medicine and Tissue Engineering

The introduction of new regenerative therapeutic modalities in the veterinary practice has recently picked up a lot of interest. Stem cells are undifferentiated cells with a high capacity to self-renew and develop into tissue cells with specific roles. Hence, they are an effective therapeutic option to ameliorate the ability of the body to repair and engineer damaged tissues. Currently, based on their facile isolation and culture procedures and the absence of ethical concerns with their use, mesenchymal stem cells (MSCs) are the most promising stem cell type for therapeutic applications. They are becoming more and more well-known in veterinary medicine because of their exceptional immunomodulatory capabilities. However, their implementation on the clinical scale is still challenging. These limitations to their use in diverse affections in different animals drive the advancement of these therapies. In the present article, we discuss the ability of MSCs as a potent therapeutic modality for the engineering of different animals' tissues including the heart, skin, digestive system (mouth, teeth, gastrointestinal tract, and liver), musculoskeletal system (tendons, ligaments, joints, muscles, and nerves), kidneys, respiratory system, and eyes based on the existing knowledge. Moreover, we highlighted the promises of the implementation of MSCs in clinical use in veterinary practice.

Intraventricular pressure gradient: A novel tool to assess the post-infarction chronic congestive heart failure

Congestive heart failure (CHF), the leading cause of death, is deemed a grave sequel of myocardial infarction (MI). The employment of left ventricular end-diastolic pressure (LVEDP), as a primary indication of CHF, becomes restricted owing to the potential impairment of heart function and caused injury to the aortic valve during its measurement. Echocardiography is the standard technique to detect cardiac dysfunction. However, it exhibits a low capacity to predict the progression of CHF post chronic MI. Being extremely sensitive, noninvasive, and preload-independent, intraventricular pressure gradient (IVPG) was lately introduced to evaluate cardiac function, specifically during cardiomyopathy. Yet, the utility of its use to assess the CHF progression after chronic MI was not investigated. Herein, in the current research, we aimed to study the efficacy of a novel echocardiographic-derived index as IVPG in the assessment of cardiac function in a chronic MI rat model with CHF. Fifty healthy male rats were involved, and MI was surgically induced in 35 of them. Six months post-surgery, all animals were examined using transthoracic conventional and color M-mode echocardiography (CMME) for IVPG. Animals were euthanized the following day after hemodynamics recording. Gross pathological and histological evaluations were performed. J-tree cluster analysis was conducted relying on ten echocardiographic parameters suggestive of CHF. Animals were merged into two main clusters: CHF+ (MI/HF + group, n = 22) and CHF– (n = 28) that was joined from Sham (n = 15), and MI/HF– (n = 13) groups. MI/HF+ group showed the most severe echocardiographic, hemodynamic, anatomic, and histologic alterations. There was no significant change in the total IVPG among various groups. However, the basal IVPG was significantly increased in MI/HF+ group compared to the other groups. The remaining IVPG measures were considerably increased in the MI/HF+ group than in the Sham one. The segmental IVPG measures were significantly correlated with the anatomical, histological, echocardiographic, and hemodynamic findings except for the heart rate. Moreover, they were significant predictors of CHF following a long-standing MI. Conclusively, IVPG obtained from CMME is a substantially promising noninvasive tool with a high ability to detect and predict the progression of CHF following chronic MI compared to conventional echocardiography.

Changes in Cardiac Function During the Development of Uremic Cardiomyopathy and the Effect of Salvianolic Acid B Administration in a Rat Model

Background

Uremic cardiomyopathy (UC), the main cause of death in progressive chronic kidney disease (CKD), is characterized by diastolic dysfunction. Intraventricular pressure gradients (IVPG) derived from color m-mode echocardiography (CMME) and two-dimensional speckle tracking echocardiography (2DSTE) were established as novel echocardiographic approaches for non-invasive and repeatable assessment of cardiac function. Previously, salvianolic acid B (Sal B) showed the potential to alleviate concentric LV hypertrophy in the pressure overload model. The purpose of this study was to evaluate the changes in cardiac function in UC and assess the efficacy of Sal B therapy using IVPG and 2DSTE techniques.

Materials and Methods

Twenty-four rats underwent subtotal nephrectomy to produce progressive renal failure and were allocated equally into UC (n = 12) and Sal B-UC (n = 12) groups and monitored for 8 weeks. A sham-operated group was also included in this study (n = 12). Sal B was injected from weeks 4 to 8 in the Sal B-UC group. Conventional echocardiography, 2DSTE, and CMME were performed every 2 weeks post-operation, concomitantly with an evaluation of renal function. Histopathological and immunohistochemistry analyses were carried out to confirm the echocardiography findings.

Results

Renal failure and myocardial dysfunction were confirmed in the UC group from weeks 2 through 8. Eccentric and concentric hypertrophy was observed in the UC group, while the Sal B-UC group showed only eccentric hypertrophy. IVPG analysis did not reveal any significant differences between the groups. Edema, inflammation, fibrosis, and immunohistochemical expression of CD3 infiltration were higher in the UC group compared with sham and Sal B-UC groups.

Conclusion

2DSTE and IVPG explored the pathophysiology during the development of UC and indicated the incidence of myocardial dysfunction before ventricular morphological changes without intracardiac flow changes. This study confirmed increased ventricular stiffness and fibrosis in UC rats which was potentially treated by Sal B via decreasing edema, inflammation, and fibrosis.

Intraventricular pressure gradient: a promising tool to predict the post-infarction chronic congestive heart failure in rats

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction: Congestive heart failure (CHF), the main reason for morbidity and mortality, is considered a serious consequence of myocardial infarction (MI). The use of left ventricular end-diastolic pressure (LVEDP) as a chief indicator of CHF becomes limited because of the possible impairment of cardiac function and induced aortic valve damage during its recording. Echocardiography is the gold standard approach to diagnose structural myocardial dysfunction. However, its ability to predict chronic CHF following MI is still limited. Recently, intraventricular pressure gradient (IVPG) was presented as a non-invasive, highly sensitive preload-independent diastolic function parameter to assess cardiac function, especially during cardiomyopathy. However, there have not been any investigations demonstrating the feasibility of IVPG in the evaluation of post-infarction chronic CHF.

Purpose

This study aimed to investigate the utility of IVPG to assess the heart function in a rat model with chronic CHF following MI with evaluating its capacity to predict these changes.

Methods

Fifty male rats were included. MI was induced via ligation of the left anterior descending artery (LAD) at the level of the atrioventricular junction (MI animals, n = 35). Sham animals were subjected to the same left thoracotomy procedure without LAD ligation (Sham animals, n = 15). Transthoracic conventional echocardiography and colour M-mode echocardiography (CMME) for IVPG were performed in all animals 6 months post-surgery. The next day, animals were anesthetized, ventilated, and euthanized after the recording of hemodynamics. The heart weight, and lung and liver wet-to-dry weight ratios were recorded. J-tree cluster-analysis was performed based on ten echocardiographic variables indicative of CHF.

Results

Based on the cluster analysis, animals were joined into two clusters; CHF+ (n = 22) and named MI/HF+, and CHF- (n = 28) that was joined from sham (n = 15), and MI/HF- (n = 13). MI/HF+ presented the most severe anatomical and echocardiographic changes indicative of CHF with significant reduction of all IVPG indices and impairment of the hemodynamics. The IVPG indices were significantly (P&lt; 0.0001) correlated with the anatomical and echocardiographic findings, LVDP, LVEDP, HR, -dP/dtmin, and Tau. Meanwhile, LVSP was only significantly correlated with apical IVPG (R = 0.677, P = 0.022). dP/dtmax was significantly correlated with total IVPG, basal IVPG, and apical IVPG (R = 0.797, P = 0.017, R = 0.724, P = 0.003, and R = 0.652, P = 0.026 ; respectively). Moreover, total, basal, mid-to-apical, mid-, and apical IVPG were significant (P&lt; 0.0001) predictors of chronic CHF following MI.

Conclusion

Compared to the structural, and functional indices of conventional echocardiography, IVPG derived from CMME could provide a substantial non-invasive tool to diagnose and predict CHF after long-term MI.

Treatment of portal vein thrombosis using vascular access port implantation in a Dalmatian dog: A case report

Background:

Portal vein thrombosis is a disease with potentially deleterious outcomes including portal vein hypertension and intestinal infarction. The factors contributing is various; however, dogs with with acute portal vein thrombosis or multiple thromboses are less likely to survive. Therefore, acute development of portal hypertension has a requires an immediate treatment.

Case Description:

A 10-year-old Dalmatian was referred for syncope and azotemia, hyperammonemia. After each examinations including computed tomography scan, we diagnosed with acute portal vein thrombosis with unknown cause. A portal vein port was inserted to prevent and control the portal vein thrombus. The port was placed in abdomen subcutaneously after the position of the catheter were stabilized. Low-molecular-weight heparin was injected from the port to manage thrombosis after the operation. This case responded well to this treatment. Syncope and azotemia, hyperammonemia resolved and no relapse of thrombosis was found 6 months after the operation.

Conclusion:

Implantable vascular access port is a drug delivery system with the advantage of dealing with treatment-resistant acute portal vein thrombosis.

Smart/stimuli-responsive hydrogels: Cutting-edge platforms for tissue engineering and other biomedical applications

Recently, biomedicine and tissue regeneration have emerged as great advances that impacted the spectrum of healthcare. This left the door open for further improvement of their applications to revitalize the impaired tissues. Hence, restoring their functions. The implementation of therapeutic protocols that merge biomimetic scaffolds, bioactive molecules, and cells plays a pivotal role in this track. Smart/stimuli-responsive hydrogels are remarkable three-dimensional (3D) bioscaffolds intended for tissue engineering and other biomedical purposes. They can simulate the physicochemical, mechanical, and biological characters of the innate tissues. Also, they provide the aqueous conditions for cell growth, support 3D conformation, provide mechanical stability for the cells, and serve as potent delivery matrices for bioactive molecules. Many natural and artificial polymers were broadly utilized to design these intelligent platforms with novel advanced characteristics and tailored functionalities that fit such applications. In the present review, we highlighted the different types of smart/stimuli-responsive hydrogels with emphasis on their synthesis scheme. Besides, the mechanisms of their responsiveness to different stimuli were elaborated. Their potential for tissue engineering applications was discussed. Furthermore, their exploitation in other biomedical applications as targeted drug delivery, smart biosensors, actuators, 3D and 4D printing, and 3D cell culture were outlined. In addition, we threw light on smart self-healing hydrogels and their applications in biomedicine. Eventually, we presented their future perceptions in biomedical and tissue regeneration applications. Conclusively, current progress in the design of smart/stimuli-responsive hydrogels enhances their prospective to function as intelligent, and sophisticated systems in different biomedical applications.

Evaluation of Changes in the Cardiac Function before and after Transcatheter Edge-to-Edge Mitral Valve Repair in Healthy Dogs: Conventional and Novel Echocardiography

Mitral valve regurgitation is a common canine heart disease. Transcatheter Edge-to-Edge Repair (TEER) is a transcatheter, edge-to-edge mitral repair device that uses a hybrid approach. No detailed information has been published on the hemodynamic effect of TEER on cardiac function. The aim of this report is to provide a longitudinal observation of the cardiac functional changes observed after TEER implantation in normal dogs using traditional, two-dimensional speckle tracking, and color M-mode echocardiographic methods. In the current report, TEER was implanted into two healthy dogs under general anesthesia. An echocardiographic examination was performed at baseline and weekly postoperative follow-ups were conducted until the fourth week. Successful TEER implantation was achieved with a short operation time (98 and 63 min) in the two dogs. Functional mitral valve regurgitation, elevated E/e' ratio, elevated radial strain, and stable intraventricular pressure gradients (IVPG) were observed after the operation in the dogs. Mild non progressive mitral valve stenosis was observed in both dogs. TEER is a minimally invasive method for mitral valve surgery that necessitates more clinical trials. With longitudinal observation of heart function using novel approaches, better outcomes will be expected.

Role of multidrug resistance-associated proteins in cancer therapeutics: past, present, and future perspectives

Cancer, a major public health problem, is one of the world's top leading causes of death. Common treatments for cancer include cytotoxic chemotherapy, surgery, targeted drugs, endocrine therapy, and immunotherapy. However, despite the outstanding achievements in cancer therapies during the last years, resistance to conventional chemotherapeutic agents and new targeted drugs is still the major challenge. In the present review, we explain the different mechanisms involved in cancer therapy and the detailed outlines of cancer drug resistance regarding multidrug resistance-associated proteins (MRPs) and their role in treatment failures by common chemotherapeutic agents. Further, different modulators of MRPs are presented. Finally, we outlined the models used to analyze MRP transporters and proposed a future impact that may set up a base or pave the way for many researchers to investigate the cancer MRP further.

Effect of Loading Changes on the Intraventricular Pressure Measured by Color M-Mode Echocardiography in Rats

Evaluation of diastolic function is a pivotal challenge due to limitations of the conventional echocardiography, especially when the heart rate is rapid as in rats. Currently, by using color M-mode echocardiography (CMME), intraventricular pressure difference (IVPD) and intraventricular pressure gradient (IVPG) in early diastole can be generated and are available as echocardiographic indices. These indices are expected to be useful for the early diagnosis of heart failure (HF), especially diastolic dysfunction. There have not been any studies demonstrating changes in IVPD and IVPG in response to changes in loading conditions in rats. Therefore, the present study aims to evaluate CMME-derived IVPD and IVPG changes in rats under various loading conditions. Twenty rats were included, divided into two groups for two different experiments, and underwent jugular vein catheterization under inhalational anesthetics. Conventional echocardiography, CMME, and 2D speckle tracking echocardiography were measured at the baseline (BL), after intravenous infusion of milrinone (MIL, n = 10), and after the infusion of hydroxyethyl starch (HES, n = 10). Left ventricular IVPD and IVPG were calculated from color M-mode images and categorized into total, basal, mid-to-apical, mid, and apical parts, and the percentage of the corresponding part was calculated. In comparison to the BL, the ejection fraction, mid-to-apical IVPG, mid IVPG, and apical IVPD were significantly increased after MIL administration (p < 0.05); meanwhile, the end-diastolic volume, E-wave velocity, total IVPD, and basal IVPD were significantly increased with the administration of HES (p < 0.05). The increase in mid-to-apical IVPD, mid IVPD, and apical IVPD indicated increased relaxation. A significant increase in basal IVPD reflected volume overloading by HES. CMME-derived IVPD and IVPG are useful tools for the evaluation of various loading conditions in rats. The approach used in this study provides a model for continuous data acquisition in chronic cardiac disease models without drug testing.

Tissue Harvesting Site Effect on the Canine Adipose Stromal Vascular Fraction Quantity and Quality

Simple Summary

Adipose stromal vascular fraction (SVF) cells are freshly isolated non-cultured mesenchymal stem cells, which have been recently applied in the treatment of several musculoskeletal inflammatory conditions in dogs. However, the best adipose tissue (AT) sampling site is still challenging. This study first addressed the ideal AT harvesting site in canines ranging between middle and old age, the most susceptible age to chronic musculoskeletal problems. Our results showed that the peri-ovarian region is the best AT harvesting site, which yields high amounts of SVF cells with enough adipose-derived stem cells. These data may help the further set-up of cell-based regenerative therapies at the preclinical and experimental level in canines.

Abstract

Mesenchymal stem cells (MSCs) constitute a great promise for regenerative therapy, but these cells are difficultly recovered in large amounts. A potent alternative is the stromal vascular fraction (SVF), non-cultured MSCs, separated from adipose tissue (AT). We aim to evaluate AT harvesting site effect on the SVF cells’ quantity and quality in dogs. Subcutaneous abdominal fat, falciform ligament and peri-ovarian fat were sampled. After SVF isolation, the trypan blue exclusion test and a hemocytometer were used to assess the cell viability and cellular yield. SVF cells were labeled for four surface antigenic markers, clusters of differentiation CD90, CD44, CD29, and CD45, and then examined by flow cytometry. Semi-quantitative RT-PCR was used to evaluate the gene expression of the former markers in addition to OCT-4 and CD34. SVF cells in the peri-ovarian AT recorded the highest viability% (99.63 ± 0.2%), as well as a significantly higher cellular yield (36.87 ± 19.6 × 10⁶ viable cells/gm fat, p < 0.001) and a higher expression of adipose-derived mesenchymal stem cells AD-MSCs surface markers than that of other sites. SVF cells from the peri-ovarian site revealed a higher expression of MSC markers (CD90, CD44, and CD29) and OCT-4 compared to the other sites, with weak CD45 and CD34 expressions. The positive OCT-4 expression demonstrated the pluripotency of SVF cells isolated from different sites. To conclude, the harvesting site is a strong determinant of SVF cells’ quantity and quality, and the peri-ovarian site could be the best AT sampling site in dogs.

Assessment of the Cardiac Functions Using Full Conventional Echocardiography with Tissue Doppler Imaging before and after Xylazine Sedation in Male Shiba Goats

The present study aimed to provide a complete conventional echocardiographic protocol in adult male Shiba goats by using two-dimensional, M-mode, Pulsed Wave Doppler, and tissue Doppler imaging (TDI) echocardiography, and to study concomitantly xylazine-induced alteration of cardiac functions in a highly sensitive species. For this purpose, 12 male Shiba goats were included and complete conventional echocardiography from the standard right and left parasternal views was carried to report the echocardiographic data in male Shiba goats, and also before and after xylazine (Pre-Xyl and Post-Xyl) administration (0.05 mg/IM/kg). Results revealed that the full echocardiographic protocol was feasible in all goats through different cardiac windows and good Doppler alignment was achieved with non-significant variability for assessment of the left ventricular dimensions, trans-pulmonary, trans-aortic, and trans-mitral blood flow. The TDI, which was not reported previously in goats, was successfully assessed from the standard left apical view and showed distinct systolic and diastolic patterns. Xylazine administration was found to significantly reduce heart rate, fractional shortening, and cardiac output as well as the Doppler hemodynamic parameters of the pulmonary artery, aortic and mitral inflows (p < 0.05). For TDI, the Post-Xyl group revealed a significant decrease in the myocardial velocities of the septal and lateral wall of the left ventricle. The present study provides, for the first time, complete data of conventional echocardiography in male goats using the full protocol, which is routinely used in pet's practice. Further, we illustrate in-depth the adverse effect of short-term sedative, xylazine, as used under field conditions and emphasize a simultaneous reduction in both systolic and diastolic cardiac function in goats based on full echocardiography assessment of the heart.