Anatomical variations and bilateral symmetry of roots and root canal system of mandibular first permanent molars in Saudi Arabian population utilizing cone- beam computed tomography

Aim: The aim of the study was to evaluate the anatomical variations of the roots and root canal system, and to determine the symmetry between right and left sides of mandibular first permanent molars in Saudi Arabian population using images derived from cone beam computed tomography (CBCT) scans. Methods: The CBCT scans (with the following parameters: FOV 170 × 120 mm, 90 Kv, 5–8 mA, 17.5 s exposure time and 0.25 mm voxel size) were retrieved from the database and axial, coronal and sagittal sections of mandibular first molars were examined. The number of roots, canals and type of canal configuration based on Vertucci's classification were recorded. Bilateral symmetry between right and left side of the same individuals and differences between genders were investigated. Results: Out of 174 mandibular first molars, 97.1% were two rooted and 2.9% were three rooted (distolingual root). In regards to the number of canals, 73% had three, 25.3% had four and 1.7% had two root canals. In teeth with four root canals, 90.9% of the extra canal was in the distal root, while 9.1% in the extra distolingual root. The most common canal configuration in mesial and distal root were type IV (64.9%) and type I (77%), respectively. Symmetrical analysis revealed 100% symmetry in number of roots and 56.4% in number of canals between right and left teeth in the same individual. Conclusions: Within the limitation of this study, wide range of canals configurations were noted in mandibular first molars among the Saudi Arabian population. The prevalence of three rooted mandibular first molars was relatively low. Three canals were most commonly seen in mandibular first molars. Bilateral symmetry was varied in number of canals and canals configurations, which could be of clinical significance while performing root canal treatment on both side mandibular first permanent molars

Human Colon Microbiota Transform Polycyclic Aromatic Hydrocarbons to Estrogenic Metabolites

Ingestion is an important exposure route for polycyclic aromatic hydrocarbons (PAHs) to enter the human body. Although the formation of hazardous PAH metabolites by human biotransformation enzymes is well documented, nothing is known about the PAH transformation potency of human intestinal microbiota. Using a gastrointestinal simulator, we show that human intestinal microbiota can also bioactivate PAHs, more in particular to estrogenic metabolites. PAH compounds are not estrogenic, and indeed, stomach and small intestine digestions of 62.5 nmol naphthalene, phenanthrene, pyrene, and benzo(a)pyrene showed no estrogenic effects in the human estrogen receptor bioassay. In contrast, colon digests of these PAH compounds displayed estrogenicity, equivalent to 0.31, 2.14, 2.70, and 1.48 nmol 17α-ethynylestradiol (EE2), respectively. Inactivating the colon microbiota eliminated these estrogenic effects. Liquid chromatography–mass spectrometry analysis confirmed the microbial PAH transformation by the detection of PAH metabolites 1-hydroxypyrene and 7-hydroxybenzo(a)pyrene in colon digests of pyrene and benzo(a)pyrene. Furthermore, we show that colon digests of a PAH-contaminated soil (simulated ingestion dose of 5 g/day) displayed estrogenic activity equivalent to 0.58 nmol EE2, whereas stomach or small intestine digests did not. Although the matrix in which PAHs are ingested may result in lower exposure concentrations in the gut, our results imply that the PAH bioactivation potency of colon microbiota is not eliminated by the presence of soil. Moreover, because PAH toxicity is also linked to estrogenicity of the compounds, the PAH bioactivation potency of colon microbiota suggests that current risk assessment may underestimate the risk from ingested PAHs

Design and preparation of a novel colon-targeted tablet of hydrocortisone

ABSTRACT The objective of this research was to design a new colon-targeted drug delivery system based on chitosan. The properties of the films were studied to obtain useful information about the possible applications of composite films. The composite films were used in a bilayer system to investigate their feasibility as coating materials. Tensile strength, swelling degree, solubility, biodegradation degree, Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Scanning Electron Microscope (SEM) investigations showed that the composite film was formed when chitosan and gelatin were reacted jointly. The results showed that a 6:4 blend ratio was the optimal chitosan/gelatin blend ratio. In vitro drug release results indicated that the Eudragit- and chitosan/gelatin-bilayer coating system prevented drug release in simulated intestinal fluid (SIF) and simulated gastric fluid (SGF). However, the drug release from a bilayer-coated tablet in SCF increased over time, and the drug was almost completely released after 24h. Overall, colon-targeted drug delivery was achieved by using a chitosan/gelatin complex film and a multilayer coating system

Measuring Success for a Future Vision: Defining Impact in Science Gateways/Virtual Research Environments

Scholars worldwide leverage science gateways/VREs for a wide variety of research and education endeavors spanning diverse scientific fields. Evaluating the value of a given science gateway/VRE to its constituent community is critical in obtaining the financial and human resources necessary to sustain operations and increase adoption in the user community. In this paper, we feature a variety of exemplar science gateways/VREs and detail how they define impact in terms of e.g., their purpose, operation principles, and size of user base. Further, the exemplars recognize that their science gateways/VREs will continuously evolve with technological advancements and standards in cloud computing platforms, web service architectures, data management tools and cybersecurity. Correspondingly, we present a number of technology advances that could be incorporated in next-generation science gateways/VREs to enhance their scope and scale of their operations for greater success/impact. The exemplars are selected from owners of science gateways in the Science Gateways Community Institute (SGCI) clientele in the United States, and from the owners of VREs in the International Virtual Research Environment Interest Group (VRE-IG) of the Research Data Alliance. Thus, community-driven best practices and technology advances are compiled from diverse expert groups with an international perspective to envisage futuristic science gateway/VRE innovations

Scanning tunneling microscopy of the electronic structure of chemical vapor deposited diamond films

This article discusses scanning tunneling microscopy of the electronic structure of chemical vapor deposited diamond films

Ability of Group IVB metallocene polyethers containing dienestrol to arrest the growth of selected cancer cell lines

<p>Abstract</p> <p>Background</p> <p>Monomeric Group IVB (Ti, Zr and Hf) metallocenes represent a new class of antitumor compounds. There is literature on the general biological activities of some organotin compounds. Unfortunately, there is little information with respect to the molecular level activity of these organotin compounds. We recently started focusing on the anti-cancer activity of organotin polymers that we had made for other purposes and as part of our platinum anti-cancer effort.</p> <p>Methods</p> <p>For this study, we synthesized a new series of metallocene-containing compounds coupling the metallocene unit with dienestrol, a synthetic, nonsteroidal estrogen. This is part of our effort to couple known moieties that offer antitumor activity with biologically active units hoping to increase the biological activity of the combination. The materials were confirmed to be polymeric using light scattering photometry and the structural repeat unit was verified employing matrix assisted laser desorption ionization mass spectrometry and infrared spectroscopy results.</p> <p>Results</p> <p>The polymers demonstrated the ability to suppress the growth of a series of tumor cell lines originating from breast, colon, prostrate, and lung cancers at concentrations generally lower than those required for inhibition of cell growth by the commonly used antitumor drug cisplatin.</p> <p>Conclusion</p> <p>These drugs show great promise in vitro against a number of cancer cell lines and due to their polymeric nature will most likely be less toxic than currently used metal-containing drugs such as cisplatin. These drugs also offer several addition positive aspects. First, the reactants are commercially available so that additional synthetic steps are not needed. Second, synthesis of the polymer is rapid, occurring within about 15 seconds. Third, the interfacial synthetic system is already industrially employed in the synthesis of aromatic nylons and polycarbonates. Thus, the ability to synthesize large amounts of the drugs is straight forward.</p

Magnetic hyperthermia controlled drug release in the GI tract : solving the problem of detection

Drug delivery to the gastrointestinal (GI) tract is highly challenging due to the harsh environments any drug- delivery vehicle must experience before it releases it’s drug payload. Effective targeted drug delivery systems often rely on external stimuli to effect release, therefore knowing the exact location of the capsule and when to apply an external stimulus is paramount. We present a drug delivery system for the GI tract based on coating standard gelatin drug capsules with a model eicosane- superparamagnetic iron oxide nanoparticle composite coating, which is activated using magnetic hyperthermia as an on-demand release mechanism to heat and melt the coating. We also show that the capsules can be readily detected via rapid X-ray computed tomography (CT) and magnetic resonance imaging (MRI), vital for progressing such a system towards clinical applications. This also offers the opportunity to image the dispersion of the drug payload post release. These imaging techniques also influenced capsule content and design and the delivered dosage form. The ability to easily change design demonstrates the versatility of this system, a vital advantage for modern, patient-specific medicine

Honey, a Gift from Nature to Health and Beauty: A Review

Benefits of honey are contributed by the composition of its elements such as glucose, fructose, glucose oxidase, vitamins and phenolic compounds. For health, honey can be used to treat wounds due to the antibacterial activity conferred by the hydrogen peroxide produced by glucose oxidase in honey. Anti-inflammatory, anti-oxidant, deodorizing and tissue regeneration activities in honey also help in the wound healing process. It can also be an alternative sweetener for diabetic patients to ensure compliance to a healthy diet. Moreover, honey exerts several effects such as lowering low density lipids and increasing high density lipids, thus reducing risk of atherosclerosis. In terms of beauty, honey can be used on skin and hair. It moisturizes skin through its natural humectant properties contributed by high contents of fructose and glucose. Honey treats acne on the skin due to its antibacterial activity, anti-inflammatory action and tissue repair. The hair can benefit from honey in such a way that the hair has abundance, and becomes easier to comb. However, there have not been as many studies regarding the use of honey in skin in comparison to its use for health. Therefore, future studies on honey could research its use, action and benefits in both cosmetics and dermatology

Nonsurgical management and 2-year follow-up by means of cone beam computed tomography of an invasive cervical resorption in a molar

Background: Invasive cervical resorption (ICR) is a relatively uncommon form of external tooth resorption, characterized by an invasive nature. It is usually painless and detection of lesions is often made incidentally. Three-dimensional imaging techniques, such as cone beam computed tomography (CBCT), are useful in the diagnosis and management of ICR as the true extent of the defect cannot always be estimated using conventional radiographs. Aim: The aim of this article is to report on the successful treatment of ICR in mandibular first molar by nonsurgical approach and follow-up by means of CBCT. Case report: An 18-year-old patient was referred with a complaint of unusual radiolucency in the mesial cervical area of tooth #19 with unknown etiology. Cone beam computed tomography was performed to assess the extent of the lesion in three spatial levels and diagnosis of Heithersay class III ICR was made. This case presented with ICR (Heithersay class III) on tooth #19. Nonsurgical root canal treatment and removal of the lesion from the coronal access was performed; the resorptive defect was filled with dual-cure, self-adhesive, resin-modified glass ionomer cement (RMGIC); 6-month follow-up X-ray film showed no changes at the lesion site and tooth was asymptomatic; 1-year follow-up X-ray film showed slight mesial bone loss and a probing depth of 3 mm; finally, 2-year follow-up CBCT images showed no recurrence and no further bone destruction at the lesion site. Conclusion: The intraoral radiographs revealed the resorptive changes in two dimensions; therefore, the actual extent and location of the lesions are not fully understood. On the contrary, CBCT is a very useful tool to achieve a proper diagnosis; it detects the extent of the defect more accurately and hence, improves the treatment outcomes of ICR. Clinical significance: The ICR is usually seen as a late complication to traumatic injuries of the teeth; it is essential, therefore, that the patients who were exposed to situations that can damage the integrity of periodontal tissue need to have careful periodic recalls and X-ray examinations