Deciphering the functions of Stromal Interaction Molecule-1 in amelogenesis using AmelX-iCre mice.

Introduction: The intracellular Ca2+ sensor stromal interaction molecule 1 (STIM1) is thought to play a critical role in enamel development, as its mutations cause Amelogenesis Imperfecta (AI). We recently established an ameloblast-specific (AmelX-iCre) Stim1 conditional deletion mouse model to investigate the role of STIM1 in controlling ameloblast function and differentiation in vivo (Stim1 cKO). Our pilot data (Said et al., J. Dent. Res., 2019, 98, 1002-1010) support our hypothesis for a broad role of Stim1 in amelogenesis. This paper aims to provide an in-depth characterization of the enamel phenotype observed in our Stim1 cKO model. Methods: We crossed AmelX-iCre mice with Stim1-floxed animals to develop ameloblast-specific Stim1 cKO mice. Scanning electron microscopy, energy dispersive spectroscopy, and micro- CT were used to study the enamel phenotype. RNAseq and RT-qPCR were utilized to evaluate changes in the gene expression of several key ameloblast genes. Immunohistochemistry was used to detect the amelogenin, matrix metalloprotease 20 and kallikrein 4 proteins in ameloblasts. Results: Stim1 cKO animals exhibited a hypomineralized AI phenotype, with reduced enamel volume, diminished mineral density, and lower calcium content. The mutant enamel phenotype was more severe in older Stim1 cKO mice compared to younger ones and changes in enamel volume and mineral content were more pronounced in incisors compared to molars. Exploratory RNAseq analysis of incisors' ameloblasts suggested that ablation of Stim1 altered the expression levels of several genes encoding enamel matrix proteins which were confirmed by subsequent RT-qPCR. On the other hand, RT-qPCR analysis of molars' ameloblasts showed non-significant differences in the expression levels of enamel matrix genes between control and Stim1-deficient cells. Moreover, gene expression analysis of incisors' and molars' ameloblasts showed that Stim1 ablation caused changes in the expression levels of several genes associated with calcium transport and mitochondrial kinetics. Conclusions: Collectively, these findings suggest that the loss of Stim1 in ameloblasts may impact enamel mineralization and ameloblast gene expression.

When the clock ticks wrong with COVID-19.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a member of the coronavirus family that causes the novel coronavirus disease first diagnosed in 2019 (COVID-19). Although many studies have been carried out in recent months to determine why the disease clinical presentations and outcomes can vary significantly from asymptomatic to severe or lethal, the underlying mechanisms are not fully understood. It is likely that unique individual characteristics can strongly influence the broad disease variability; thus, tailored diagnostic and therapeutic approaches are needed to improve clinical outcomes. The circadian clock is a critical regulatory mechanism orchestrating major physiological and pathological processes. It is generally accepted that more than half of the cell-specific genes in any given organ are under circadian control. Although it is known that a specific role of the circadian clock is to coordinate the immune system's steady-state function and response to infectious threats, the links between the circadian clock and SARS-CoV-2 infection are only now emerging. How inter-individual variability of the circadian profile and its dysregulation may play a role in the differences noted in the COVID-19-related disease presentations, and outcome remains largely underinvestigated. This review summarizes the current evidence on the potential links between circadian clock dysregulation and SARS-CoV-2 infection susceptibility, disease presentation and progression, and clinical outcomes. Further research in this area may contribute towards novel circadian-centred prognostic, diagnostic and therapeutic approaches for COVID-19 in the era of precision health.

Detection of Benign and Malignant Tumors in Skin Empowered with Transfer Learning.

Skin cancer is a major type of cancer with rapidly increasing victims all over the world. It is very much important to detect skin cancer in the early stages. Computer-developed diagnosis systems helped the physicians to diagnose disease, which allows appropriate treatment and increases the survival ratio of patients. In the proposed system, the classification problem of skin disease is tackled. An automated and reliable system for the classification of malignant and benign tumors is developed. In this system, a customized pretrained Deep Convolutional Neural Network (DCNN) is implemented. The pretrained AlexNet model is customized by replacing the last layers according to the proposed system problem. The softmax layer is modified according to binary classification detection. The proposed system model is well trained on malignant and benign tumors skin cancer dataset of 1920 images, where each class contains 960 images. After good training, the proposed system model is validated on 480 images, where the size of images of each class is 240. The proposed system model is analyzed using the following parameters: accuracy, sensitivity, specificity, Positive Predicted Values (PPV), Negative Predicted Value (NPV), False Positive Ratio (FPR), False Negative Ratio (FNR), Likelihood Ratio Positive (LRP), and Likelihood Ratio Negative (LRN). The accuracy achieved through the proposed system model is 87.1%, which is higher than traditional methods of classification.

An IoMT-Enabled Smart Healthcare Model to Monitor Elderly People Using Machine Learning Technique.

The Internet of Medical Things (IoMT) enables digital devices to gather, infer, and broadcast health data via the cloud platform. The phenomenal growth of the IoMT is fueled by many factors, including the widespread and growing availability of wearables and the ever-decreasing cost of sensor-based technology. The cost of related healthcare will rise as the global population of elderly people grows in parallel with an overall life expectancy that demands affordable healthcare services, solutions, and developments. IoMT may bring revolution in the medical sciences in terms of the quality of healthcare of elderly people while entangled with machine learning (ML) algorithms. The effectiveness of the smart healthcare (SHC) model to monitor elderly people was observed by performing tests on IoMT datasets. For evaluation, the precision, recall, fscore, accuracy, and ROC values are computed. The authors also compare the results of the SHC model with different conventional popular ML techniques, e.g., support vector machine (SVM), K-nearest neighbor (KNN), and decision tree (DT), to analyze the effectiveness of the result.

Edge AI-Based Automated Detection and Classification of Road Anomalies in VANET Using Deep Learning.

Road surface defects are crucial problems for safe and smooth traffic flow. Due to climate changes, low quality of construction material, large flow of traffic, and heavy vehicles, road surface anomalies are increasing rapidly. Detection and repairing of these defects are necessary for the safety of drivers, passengers, and vehicles from mechanical faults. In this modern era, autonomous vehicles are an active research area that controls itself with the help of in-vehicle sensors without human commands, especially after the emergence of deep learning (DNN) techniques. A combination of sensors and DNN techniques can be useful for unmanned vehicles for the perception of their surroundings for the detection of tracks and obstacles for smooth traveling based on the deployment of artificial intelligence in vehicles. One of the biggest challenges for autonomous vehicles is to avoid the critical road defects that may lead to dangerous situations. To solve the accident issues and share emergency information, the Intelligent Transportation System (ITS) introduced the concept of vehicular network termed as vehicular ad hoc network (VANET) for achieving security and safety in a traffic flow. A novel mechanism is proposed for the automatic detection of road anomalies by autonomous vehicles and providing road information to upcoming vehicles based on Edge AI and VANET. Road images captured via camera and deployment of the trained model for road anomaly detection in a vehicle could help to reduce the accident rate and risk of hazards on poor road conditions. The techniques Residual Convolutional Neural Network (ResNet-18) and Visual Geometry Group (VGG-11) are applied for the automatic detection and classification of the road with anomalies such as a pothole, bump, crack, and plain roads without anomalies using the dataset from different online sources. The results show that the applied models performed well than other techniques used for road anomalies identification.

Differential response of oxidative and glycolytic skeletal muscle fibers to mesterolone.

Oxidative and glycolytic muscle fibers differ in their ultrastructure, metabolism, and responses to physiological stimuli and pathological insults. We examined whether these fibers respond differentially to exogenous anabolic androgenic steroids (AASs) by comparing morphological and histological changes between the oxidative anterior latissimus dorsi (ALD) and glycolytic pectoralis major (PM) fibers in adult avian muscles. Adult female White Leghorn chickens (Gallus gallus) were randomly divided into five groups: a vehicle control and four mesterolone treatment groups (4, 8, 12, and 16 mg/kg). Mesterolone was administered orally every three days for four weeks. Immunocytochemical techniques and morphometric analyses were employed to measure the changes in muscle weight, fiber size, satellite cell (SC) composition, and number of myonuclei. Mesterolone increased both body and muscle weights and induced hypertrophy in glycolytic PM fibers but not in oxidative ALD fibers. Mesterolone induced SC proliferation in both muscles; however, the myonuclear accretion was noticeable only in the PM muscle. In both muscles, the collective changes maintained a constant myonuclear domain size and the changes were dose independent. In conclusion, mesterolone induced distinct dose-independent effects in avian oxidative and glycolytic skeletal muscle fibers; these findings might be clinically valuable in the treatment of age-related sarcopenia.

Calcium Sets the Clock in Ameloblasts.

BACKGROUND: Stromal interaction molecule 1 (STIM1) is one of the main components of the store operated Ca2+ entry (SOCE) signaling pathway. Individuals with mutated STIM1 present severely hypomineralized enamel characterized as amelogenesis imperfecta (AI) but the downstream molecular mechanisms involved remain unclear. Circadian clock signaling plays a key role in regulating the enamel thickness and mineralization, but the effects of STIM1-mediated AI on circadian clock are unknown. OBJECTIVES: The aim of this study is to examine the potential links between SOCE and the circadian clock during amelogenesis. METHODS: We have generated mice with ameloblast-specific deletion of Stim1 (Stim1 fl/fl/Amelx-iCre+/+, Stim1 cKO) and analyzed circadian gene expression profile in Stim1 cKO compared to control (Stim1 fl/fl/Amelx-iCre-/-) using ameloblast micro-dissection and RNA micro-array of 84 circadian genes. Expression level changes were validated by qRT-PCR and immunohistochemistry. RESULTS: Stim1 deletion has resulted in significant upregulation of the core circadian activator gene Brain and Muscle Aryl Hydrocarbon Receptor Nuclear Translocation 1 (Bmal1) and downregulation of the circadian inhibitor Period 2 (Per2). Our analyses also revealed that SOCE disruption results in dysregulation of two additional circadian regulators; p38α mitogen-activated protein kinase (MAPK14) and transforming growth factor-beta1 (TGF-ß1). Both MAPK14 and TGF-ß1 pathways are known to play major roles in enamel secretion and their dysregulation has been previously implicated in the development of AI phenotype. CONCLUSION: These data indicate that disruption of SOCE significantly affects the ameloblasts molecular circadian clock, suggesting that alteration of the circadian clock may be partly involved in the development of STIM1-mediated AI.

In Vitro Caries Models for the Assessment of Novel Restorative Materials.

Due to the high failure rates of traditional dental restorations, there is an ongoing effort to develop modified and new restorative biomaterials in dentistry. Being the most commonly used restorative material, most of these efforts primarily aim to improve dental composite. Generally, the main objective of such modifications is to enhance the restorative physical and antimicrobial properties in order to limit micro-leakage and inhibit bacterial biofilm cultivation. Herein, we describe the process of designing a simple in vitro model to assess the physical and antimicrobial properties of novel restorative materials in addition to evaluating their effect on the fragile balance between enamel de- and remineralization.

In Vivo Rodent Models for Studying Dental Caries and Pulp Disease.

Dental caries is an infectious oral disease caused primarily by complex interactions of cariogenic oral flora (biofilm) with dietary carbohydrates on the tooth surface over time. Streptococcus mutans and Streptococcus sobrinus (S. mutans and S. sobrinus) are the most prevalent cariogenic species within the oral biofilm and considered the main etiological agents of caries. Pulp exposure and infection can be caused by trauma, carious lesion, and mechanical reasons. Pulp response to these exposures depends on the state of the pulp as well as the potential bacterial contamination of pulp tissue. Herein, we describe the process of using two in vivo rodent models to study the progression of dental caries and pulp disease: a nutritional microbial model and a pulp disease induction model. The progression of the carious lesion and pulpal infections in both models was assessed by micro-CT imaging and histomorphometric analysis. Moreover, the pulp disease induction models can be used to compare and assess the antibacterial and reparative properties of the different pulp capping materials.

Saliva and Gingival Crevicular Fluid (GCF) Collection for Biomarker Screening.

Assaying different biological markers (biomarkers) is commonly used to monitor health status and aid in the diagnosis of diseases. With the recent advances in highly sensitive protein assays, whole saliva (WS) and gingival crevicular fluid (GCF) appear to be fluids that may contain important biomarkers with various applications in dentistry and medicine. Herein, we describe the process of GCF and WS sample collection and preparation for assaying clinically relevant biomarkers in clinical screening trials. Analysis of biomarkers in WS and GCF represents an easy and practical approach for the diagnosis and screening of different pathological conditions particularly in epidemiological surveys.

Myogenic regulatory factors: The orchestrators of myogenesis after 30 years of discovery.

Prenatal and postnatal myogenesis share many cellular and molecular aspects. Myogenic regulatory factors are basic Helix-Loop-Helix transcription factors that indispensably regulate both processes. These factors (Myf5, MyoD, Myogenin, and MRF4) function as an orchestrating cascade, with some overlapped actions. Prenatally, myogenic regulatory factors are restrictedly expressed in somite-derived myogenic progenitor cells and their derived myoblasts. Postnatally, myogenic regulatory factors are important in regulating the myogenesis process via satellite cells. Many positive and negative regulatory mechanisms exist either between myogenic regulatory factors themselves or between myogenic regulatory factors and other proteins. Upstream factors and signals are also involved in the control of myogenic regulatory factors expression within different prenatal and postnatal myogenic cells. Here, the authors have conducted a thorough and an up-to-date review of the myogenic regulatory factors since their discovery 30 years ago. This review discusses the myogenic regulatory factors structure, mechanism of action, and roles and regulations during prenatal and postnatal myogenesis. Impact statement Myogenic regulatory factors (MRFs) are key players in the process of myogenesis. Despite a considerable amount of literature regarding these factors, their exact mechanisms of actions are still incompletely understood with several overlapped functions. Herein, we revised what has hitherto been reported in the literature regarding MRF structures, molecular pathways that regulate their activities, and their roles during pre- and post-natal myogenesis. The work submitted in this review article is considered of great importance for researchers in the field of skeletal muscle formation and regeneration, as it provides a comprehensive summary of all the biological aspects of MRFs and advances a better understanding of the cellular and molecular mechanisms regulating myogenesis. Indeed, attaining a better understanding of MRFs could be utilized in developing novel therapeutic protocols for multiple myopathies.

Myogenic Satellite Cells: Biological Milieu and Possible Clinical Applications.

Adult skeletal muscle is a post-mitotic terminally differentiated tissue that possesses an immense potential for regeneration after injury. This regeneration can be achieved by adult stem cells named satellite cells that inhabit the muscular tissue. These cells were first identified in 1961 and were described as being wedged between the plasma membrane of the muscle fiber and the surrounding basement membrane. Since their discovery, many researchers investigated their embryological origin and the exact role they play in muscle regeneration and repair. Under normal conditions, satellite cells are retained in a quiescent state and when required, these cells are activated to proliferate and differentiate to repair pre-existing muscle fibers or to a lesser extent fuse with each other to form new myofibers. During skeletal muscle regeneration, satellite cell actions are regulated through a cascade of complex signaling pathways that are influenced by multiple extrinsic factors within the satellite cell micro-environment. Here, the basic concepts were studied about satellite cells, their development, function, distribution and the different cellular and molecular mechanisms that regulate these cells. The recent findings about some of their clinical applications and potential therapeutic use were also discussed.

Migration of the distal catheter of the ventriculoperitoneal shunt in hydrocephalus: A Comprehensive Analytical Review from an Anatomical Perspective.

There have been many reports on migration of the distal catheter of the ventriculoperitoneal shunt (VPS) since this phenomenon was recognized 50 years ago. However, there have been no attempts to analyze its different patterns or to assess these patterns in terms of potential risk to patients. We comprehensively reviewed all reports of distal VPS catheter migration indexed in PubMed and identified three different anatomical patterns of migration based on catheter extension and organs involved: (1) internal, when the catheter invades any viscus inside the thoracic, abdominal, or pelvic cavity; (2) external, when the catheter penetrates through the body wall either incompletely (subcutaneously) or completely (outside the body); and (3) compound, when the catheter penetrates a hollow viscus and protrudes through a pre-existing anatomical orifice. We also analyzed the association between each migration type and several key factors. External migration occurred mostly in infants. In contrast, internal migration occurred mostly in adults. A body wall weakness was not a risk factor for catheter protrusion. Shunt duration was a critical factor in the migration pattern, as most newly-replaced shunts tended to migrate externally. Clinicians must pay close attention to cases of large bowel perforation, since they were most often associated with intracranial infections. The organ involved in compound migration could determine the route of extrusion, as the bowel was involved in all trans-anal migrations and the stomach in most trans-oral cases. Clin. Anat. 30:821-830, 2017. © 2017Wiley Periodicals, Inc.

Assessment of risk factors for postdural puncture headache in women undergoing cesarean delivery in Jordan: a retrospective analytical study.

PURPOSE: Postdural puncture headache (PDPH) is one of the most recognized complications after spinal anesthesia in women undergoing cesarean delivery. This study aimed to investigate the incidence of PDPH and its associated risk factors in women undergoing cesarean delivery in Jordan. PATIENTS AND METHODS: This study included all women who underwent cesarean delivery at King Abdullah University Hospital in Jordan during 2015. Patient characteristics including age, weight, occurrence of PDPH, needle type, repeated puncture attempt, history of spinal anesthesia and PDPH, presence of tension headache, preeclampsia, migraine, sinusitis, and caffeine withdrawal were collated from hospital records. Statistical analyses were performed to assess the association of these characteristics with PDPH. RESULTS: The study cohort consisted of 680 women. Among these, only 43 (6.3%) had developed PDPH. The only factors that showed significant association (P<0.01) with PDPH were repeated puncture attempt and presence of tension headache. The repeated puncture attempt increased the risk of PDPH 2.55-fold, while presence of tension headache increased the risk 4.60-fold. Furthermore, the use of the traumatic 27 G Spinostar needle increased the risk of repeated puncture attempt 28.45-fold (P<0.01) compared with the use of the pencil-point 25 G Whitacre needle. CONCLUSION: The major risk factors associated with the incidence of PDPH in women undergoing cesarean delivery in Jordan are repeated puncture attempt and presence of tension headache. The use of the pencil-point 25 G Whitacre needle is recommended since this was associated with a substantially reduced risk of repeated spinal puncture than the traumatic 27 G Spinostar needle.

Sustanon induces dose-independent hypertrophy and satellite cell proliferation in slow oxidative fibers of avian skeletal muscle.

Sustanon is a well-known anabolic drug that is used to treat hypogonadism and restore muscle mass and bone density. As research to date has been limited to its effects in glycolytic fibers, this study aimed to investigate the dose-related effects of Sustanon on the oxidative fibers of avian skeletal muscle. Adult female chickens were randomly divided into 4 groups: control (C), received a dose of 100 µl normal saline per injection; and Sustanon-1, -2, and -3 (S1, S2, and S3), that received a dose of 12.5, 25, or 50 mg/kg Sustanon per injection, respectively. Each bird received 4 injections at weekly intervals (1 injection/week). Robust histochemical and immunofluorescent techniques along with morphometric analyses were applied to determine the oxidative activity and morphological variations of the oxidative muscle fibers in all groups. Sustanon-treated groups exhibited significant increases in fiber size and numbers of satellite cells and myonuclei compared to the control group. However, no significant variations were found between Sustanon-treated groups in the aforementioned indices. In conclusion, Sustanon induced oxidative fiber hypertrophy that was associated with satellite cell proliferation and myonuclear accretion in avian skeletal muscle. Furthermore, the effects of Sustanon appeared to be dose-independent.

Successful Management of Intraoperative Acute Bilateral Pulmonary Embolism in a High Grade Astrocytoma Patient.

BACKGROUND Intraoperative pulmonary embolism (PE) is a rare life-threatening complication in patients undergoing surgical intervention. Generally, cancer patients have a higher risk for developing this complication. Unfortunately, there is no standard procedure for its management. CASE REPORT We report the case of a 39-year-old woman with high-grade glioma in the right frontal lobe who was admitted to the surgical theater for craniotomy and excision of the tumor. During the general anesthesia procedure and just before inserting the central venous line, her end-tidal CO2 and O2 saturation dropped sharply. The anesthesiologist quickly responded with an aggressive resuscitation procedure that included aspiration through the central venous line, 100% O2, and IV administration of ephedrine 6 mg, colloid 500 mL, normal saline 500 mL, and heparin 5000 IU. The patient was extubated and remained in the supine position until she regained consciousness and her vital signs returned to normal. Subsequent radiological examination revealed a massive bilateral PE. A retrievable inferior vena cava (IVC) filter was inserted, and enoxaparin anticoagulant therapy was prescribed to stabilize the patient's condition. After 3 weeks, she underwent an uneventful craniotomy procedure and was discharged a week later under the enoxaparin therapy. CONCLUSIONS The successful management of intraoperative PE requires a quick, accurate diagnosis accompanied with an aggressive, fast response. Anesthesiologists are usually the ones who are held accountable for the diagnosis and early management of this complication. They must be aware of the possibility of such a complication and be ready to react properly and decisively in the operation theater.