Knowledge of Dental Students and Practitioners About Medication-Related Osteonecrosis of the Jaw in the Central Region of Saudi Arabia.

BACKGROUND: Bisphosphonates (BPs) are often used in treating benign and malignant disorders. Medication-related osteonecrosis of the jaw (MRONJ) is a significant problem that arises from the long-term use of BPs. OBJECTIVE: In this study, we assessed the knowledge of students and dentists about MRONJ in the central region of Saudi Arabia. METHODS: A cross-sectional study was conducted to collect information from dental students and practitioners from the central region of Saudi Arabia. A valid, reliable, and structured questionnaire was used to gather data using a non-probability convenient sampling technique. IBM SPSS Statistics for Windows, Version 22.0 (Released 2013; IBM Corp., Armonk, New York, United States) was used to analyse the data. The descriptive data were expressed as frequencies and percentages to evaluate the association between dentists and students concerning overall knowledge related to osteonecrosis of the jaw, and a chi-squared test was applied. RESULTS: In total, 250 individuals completed the questionnaire. The general knowledge of antiresorptive/antiangiogenic medications showed that most dentists (87.5%) and students (68.4%) knew about BP medications. A general lack of understanding about the therapeutic uses of antiangiogenic and antiresorptive medications was demonstrated by the participants. A significant proportion of dentists (58.8%) and students (50.9%) were not convinced that invasive dental procedures can be safely performed on patients receiving intravenous BP therapy. A significant proportion of the participants in the sample were unclear of the principal diseases that antiresorptive and antiangiogenic medications target. A mere 22% of respondents were aware of the accurate definition of medications-related MRONJ. CONCLUSION: There is insufficient knowledge about MRONJ among students and practitioners. Therefore, these findings suggest increased emphasis should be placed on educating dentists and students about this condition to ensure patients receive the best possible care.

Frequency and Severity of Temporomandibular Disorders Among Weightlifters at Fitness Centers in a Subset Population of Saudi Arabia: A Cross-Sectional Observational Study.

Background Teeth clenching in weightlifters is a common finding that may result in temporomandibular disorders (TMDs). This study aimed to evaluate the severity and frequency of TMDs among weightlifters at fitness centers in Saudi Arabia. Methods A cross-sectional study was designed to collect data from weightlifters at fitness centers. A non-probability convenient sampling technique was applied using a valid and reliable Fonseca's questionnaire on a Google Sheet (Google, Mountain View, CA) to collect participant data. The survey was conducted from November 2022 to April 2023. Epi Info software (CDC, Atlanta, Georgia) was used to calculate the sample size, and a minimum sample of 278 was required. The data underwent analysis using SPSS version 20 (IBM Corp., Armonk, NY). Results Data analyzed from 375 participants revealed that 192 (51.2%) had mild signs of TMD, whereas 128 (34.13%) of the respondents had no symptoms of TMD. A significant difference was observed among female participants in all the temporomandibular joint severity categories. A statistically significant difference was observed between both genders concerning frequent headaches, earache, and nervousness. Conclusion The prevalence of TMD is high worldwide. Unsupervised athletic activity may result in the occurrence of TMD. Fonseca's questionnaire findings reveal a mild prevalence of TMD in weightlifters.

Endothelial progenitor cell-derived small extracellular vesicles for myocardial angiogenesis and revascularization.

Background: Endothelial progenitor cells (EPCs) have been well-studied for their differentiation potential and paracrine activity in vitro and in experimental animal studies. EPCs are the precursors of endothelial cells (ECs) and a rich source of pro-angiogenic factors, and hence, possess enormous potential to treat ischemic heart through myocardial angiogenesis. Their proven safety and efficacy observed during the pre-clinical and clinical studies have portrayed them as a near ideal cell type for cell-based therapy of ischemic heart disease.In response to the chemical cues from the ischemic heart, EPCs from the bone marrow and peripheral circulation home-in to the ischemic myocardium and participate in the intrinsic repair process at the molecular and cellular levels through paracrine activity and EC differentiation. EPCs also release small extracellular vesicles (sEVs) loaded with bioactive molecules as part of their paracrine activity for intercellular communication to participate in the reparative process in the heart. Aim: This literature review is based on the published data regarding the characteristic features of EPC-derived sEVs and their proteomic and genomic payload, besides facilitating safe and effective repair of the ischemic myocardium. In light of the encouraging published data, translational and clinical assessment of EPC-derived sEVs is warranted. We report the recent experimental animal studies and their findings using EPC-derived sEVs on cardiac angiogenesis and preservation of cardiac function. Relevance for Patients: With the promising results from pre-clinical studies, clinical trials should be conducted to assess the clinical utility of EPC-derived sEVs in the treatment of the ischemic myocardium.

Remineralization Effect of Zamzam Water on Initial Artificial Carious Lesion of Permanent Teeth.

INTRODUCTION: Chemical testing showed that Zamzam water is completely safe to drink and has health benefits due to its high percentage of sodium, calcium, magnesium, and many other minerals. The purpose of this study was to evaluate the remineralization effect of Zamzam water on extracted premolars using the Vickers Microhardness test. METHODS: Teeth samples (N=40) with artificially induced carious lesions were divided randomly into four groups: Study group (I) treated with agitated Zamzam water (n=10), study group (II) treated with non-agitated Zamzam water (n=10), control positive group (III) treated with sodium fluoride (n=10), and control negative group (IV) treated with deionized water (n=10). Teeth were subjected to microhardness testing before and after artificial demineralization and after remineralization treatment within the four groups. RESULTS: Following treatment with different solutions in both study and control groups, there was an increase in microhardness after remineralization but with varying degrees. The highest increase in microhardness was shown after remineralization with sodium fluoride followed by agitated Zamzam water. CONCLUSION: Zamzam water with agitation causes an increase in the microhardness of the enamel surface after demineralization. Zamzam water is an effective remineralizing agent in initial carious lesions, and its efficacy is comparable to that of sodium fluoride.

Endovascular approach in the management of idiopathic myointimal hyperplasia of the inferior mesenteric vein.

BACKGROUND: Idiopathic myointimal hyperplasia of the mesenteric vein (IMHMV) is a rare, often undiagnosed pathology affecting the colon. Patients typically present with severe abdominal pain and inflammation caused by smooth muscle proliferation of the veins, leading to arterialization, stenosis, and potential occlusion. The etiology remains unclear, but it has been hypothesized that an arteriovenous connection may be associated with the pathology. This is the first reported case indicating such an association. This case additionally highlights the potential utility of endovascular treatment, as endovascular embolization is generally a less invasive alternative to surgical resection in the treatment of such vascular disorders. CASE PRESENTATION: This report describes a 24-year-old female patient with findings of colitis and an abnormal arteriovenous connection of the inferior mesenteric arterial and venous systems. Partial embolization of this arteriovenous connection temporarily improved the patient's condition, but her symptoms ultimately returned due to the presence of multiple smaller feeder vessels not amenable to embolization, necessitating colonic resection for definitive treatment. Although prior reports have hypothesized that arterial pressurization of the veins may precipitate myointimal hyperplasia, to the authors' knowledge, this is the first report of IMHMV with an associated abnormal arteriovenous connection. CONCLUSIONS: This case illustrates the possibility of an association between an arteriovenous connection and IMHMV. This rare diagnosis should be considered in patients with a similar presentation of abdominal pain after common etiologies like IBD have been excluded.

Model of spontaneous droplet transport on a soft viscoelastic substrate with nonuniform thickness.

Dynamic wetting of droplets on soft solids has many industrial and biological applications which require an understanding of the underlying fluid transport mechanism. Here we study the case of a droplet on a viscoelastic substrate of variable thickness which is known to give rise to a spontaneous droplet transport. This phenomenon is known as droplet durotaxis and has been observed experimentally. Here we develop a model assuming a small linear gradient in substrate thickness to reveal the physical mechanism behind this transport phenomena. We show the variable thickness causes an asymmetric deformation along the drop contact line, which causes a variation in the contact angle. This generates a net driving force on the drop, causing it to move in the direction of higher thickness. The resulting drop velocity is determined by balancing the work done by the moving drop with the viscoelastic dissipation of the substrate (viscoelastic braking) and computed from a self-consistent model. We find our results to be in qualitative agreement to previously reported experimental findings.

Correction: Plateau-Rayleigh instability in a soft viscoelastic material.

Correction for 'Plateau-Rayleigh instability in a soft viscoelastic material' by S. I. Tamim et al., Soft Matter, 2021, DOI: .

Plateau-Rayleigh instability in a soft viscoelastic material.

A soft cylindrical interface endowed with surface tension can be unstable to wavy undulations. This is known as the Plateau-Rayleigh instability (PRI) and for solids the instability is governed by the competition between elasticity and capillarity. A dynamic stability analysis is performed for the cases of a soft (i) cylinder and (ii) cylindrical cavity assuming the material is viscoelastic with power-law rheology. The governing equations are made time-independent through the Laplace transform from which a solution is constructed using displacement potentials. The dispersion relationships are then derived, which depend upon the dimensionless elastocapillary number, solid Deborah number, and compressibility number, and the static stability limit, critical disturbance, and maximum growth rate are computed. This dynamic analysis recovers previous literature results in the appropriate limits. Elasticity stabilizes and compressibility destabilizes the PRI. For an incompressible material, viscoelasticity does not affect stability but does decrease the growth rate and shift the critical wavenumber to lower values. The critical wavenumber shows a more complex dependence upon compressibility for the cylinder but exhibits a predictable trend for the cylindrical cavity.

The elastic Rayleigh drop.

Bioprinting technologies rely on the formation of soft gel drops for printing tissue scaffolds and the dynamics of these drops can affect the process. A model is developed to describe the oscillations of a spherical gel drop with finite shear modulus, whose interface is held by surface tension. The governing elastodynamic equations are derived and a solution is constructed using displacement potentials decomposed into a spherical harmonic basis. The resulting nonlinear characteristic equation depends upon two dimensionless numbers, elastocapillary and compressibility, and admits two types of solutions, (i) spheroidal (or shape change) modes and (ii) torsional (rotational) modes. The torsional modes are unaffected by capillarity, whereas the frequency of shape oscillations depend upon both the elastocapillary and compressibility numbers. Two asymptotic dispersion relationships are derived and the limiting cases of the inviscid Rayleigh drop and elastic globe are recovered. For a fixed polar wavenumber, there exists an infinity of radial modes that each transition from an elasticity wave to a capillary wave upon increasing the elastocapillary number. At the transition, there is a qualitative change in the deformation field and a set of recirculation vortices develop at the free surface. Two special modes that concern volume oscillations and translational motion are characterized. A new instability is documented that reflects the balance between surface tension and compressibility effects due to the elasticity of the drop.

Epidemiology and phylogenetic analysis of VP7 and VP4 genes of rotaviruses circulating in Rawalpindi, Pakistan during 2010.

Human group A rotaviruses (RVAs) possess a large genetic diversity and new RVA strains and G/P genotype combinations are been identified frequently. Only a few studies reporting the distribution and co-circulation of RVA G and P genotypes are available for Pakistan. This hospital based study showed a RVA prevalence rate of 23.8%, which is similar to RVA detection rates estimated in other Eastern Mediterranean countries. During 2010, the following RVA strains were found to co-circulate: G1P[8] and G2P[4] (both 24.3%), G1P[6] (12.1%), G9P[8] (10.8%), G9P[6] (5.4%), G12P[6] (6.7%), G6P[1] (2.7%) and mixed infections (6.7%). Sequence analyses of selected G1, G2, G9 and G12 RVA strains revealed a close evolutionary relationship with typical human RVA strains. Sequence identities among the Pakistani VP7 RVA genes encoding G1, G2, G9 and G12 ranged between 91.5-98.7%, 99.6-98.9%, 97.7-99.5% and 99.2-99.9%, respectively. Analysis of the VP4 genes revealed co-prevalence of distinct lineages of the P[8] genotype. P[6] and P[4] showed a close relationship with typical human RVA strains detected in several Asian countries. The two G6P[1] RVA strains were closely related to typical bovine RVA strains, suggesting one or multiple interspecies transmission events. Our data provide important baseline data on the burden of RVA disease and genotype distribution in Rawalpindi, Pakistan, which is important with respect to vaccine introduction in national immunization programs.

Genomic studies in AIDS: problems and answers. Development of a statistical model integrating both longitudinal cohort studies and transversal observations of extreme cases.

Genomic studies developed to understand HIV-1 infection and pathogenesis have often lead to conflicting results. This is linked to various factors, including differences in cohort design and selection, the numbers of patients involved, the influence of population substructure, the ethnic origins of the participants, and phenotypic definition. These difficulties in the interpretation of results are examined through published studies on the role of polymorphisms in HLA and the chemokine receptors genes in AIDS. Our analysis suggests that the use of haplotypes will strengthen the results obtained in a given cohort, and meta-analysis including multiple cohorts to gather large-enough numbers of patients should also allow clarification of the genetic associations observed. A P-value of 0.001 appears to be a good compromise for significance on candidate genes in a genetic study. Due to the generally limited size of available cohorts, results will have to be validated in other cohorts. We developed a model to fit transversal case studies (extreme case-control studies) with longitudinal cohorts (all-stages patients) for observations on two gene polymorphisms of CCR5 and NQO1. Interestingly, we observe a protective effect for the CCR5-Delta32 mutant allele in 95% of the simulations based on that model when using a population of 600 subjects; however, when using populations of 250 subjects we find a significant protection in only 59% of the simulations. Our model gives thus an explanation for the discrepancies observed in the various genomic studies published in AIDS on CCR5-Delta32 and other gene polymorphisms: they result from statistical fluctuations due to a lack of power. The sizes of most seroconverter cohorts presently available seem thus insufficient since they include less than a few hundred subjects. This result underlines the power and usefulness of the transversal studies involving extreme patients and their complementarity to longitudinal studies involving seroconverter cohorts. The transposition approach of extreme case-control data into longitudinal analysis should prove useful not only in AIDS but also in other diseases induced by chronic exposure to a foreign agent or with chronic clinical manifestations.

Identification of 96 single nucleotide polymorphisms in eight genes involved in iron metabolism: efficiency of bioinformatic extraction compared with a systematic sequencing approach.

Single nucleotide polymorphisms (SNPs) can significantly contribute to the characterization of the genes predisposing to iron overloads or deficiencies. We report an SNP survey of coding and non-coding regions of eight genes involved in iron metabolism, by two successive methods. First, we made use of the public domain sequence data, by using assembled expressed sequence tags, non-redundant sequences, and SNP database screening. We extracted 77 potential SNPs of which only 31 could be further validated by sequencing DNA from 44 unrelated multi-ethnic individuals. Our results indicate that a bioinformatic approach may be effective only in those cases where candidate SNPs are extracted from two different data sources or in cases of experimentally confirmed SNPs. Second, additional systematic sequencing of DNA from 24 unrelated Breton subjects increased the number of SNPs over a total length of 86 kb to 96. The average distance between the SNPs and minor allele frequencies were higher than reported by others authors; this discrepancy may reflect the nature of the genes studied and the ethnic homogeneity of our test population.

[Level of histamine in supernatants from the basophil activation test: applications to hymenoptera allergy and drug allergy--preliminary study]. / Dosage de l'histamine sur les surnageants du test d'activation des basophiles: applications a l'allergie aux venins d'hymenopteres et a l'allergie medicamenteuse--étude préliminaire.

Histamine Release technic consists in calculating histamine liberated by blood cells in touch with an allergen. To this day, this method is only used in Hymenoptera venom allergy diagnosis. The principle of this study is to measure histamine released by activated basophils in surnageons of Basophil Activation Test (BAT) for different allergens: Hymenoptera venoms: Bee, White Faced Hornet, Vespula Wasp. Drugs: Cefaperos, Clamoxyl, Alfatil, Rapifen, Diprivan, Nesdonal, Mivacron. A threshold of positivity (amplification factor in comparison with the control) is determined for these two classes of allergens: 45 for Hymenoptera venoms and 9 for drugs. These results, compared to the other diagnosis technics (Histamine Release, Basophil Activation Test, Prick Tests) discloses very high correlation rates in each case. This method seems to be a reliable method for Hymenoptera venom allergy diagnosis and for drugs allergy diagnosis too. However, this study is based on a few number of patients, so a significant statistic conclusion can't be expressed but it opens an interesting way of research.