Review of nanomaterials in dentistry: interactions with the oral microenvironment, clinical applications, hazards, and benefits.

Interest in the use of engineered nanomaterials (ENMs) as either nanomedicines or dental materials/devices in clinical dentistry is growing. This review aims to detail the ultrafine structure, chemical composition, and reactivity of dental tissues in the context of interactions with ENMs, including the saliva, pellicle layer, and oral biofilm; then describes the applications of ENMs in dentistry in context with beneficial clinical outcomes versus potential risks. The flow rate and quality of saliva are likely to influence the behavior of ENMs in the oral cavity, but how the protein corona formed on the ENMs will alter bioavailability, or interact with the structure and proteins of the pellicle layer, as well as microbes in the biofilm, remains unclear. The tooth enamel is a dense crystalline structure that is likely to act as a barrier to ENM penetration, but underlying dentinal tubules are not. Consequently, ENMs may be used to strengthen dentine or regenerate pulp tissue. ENMs have dental applications as antibacterials for infection control, as nanofillers to improve the mechanical and bioactive properties of restoration materials, and as novel coatings on dental implants. Dentifrices and some related personal care products are already available for oral health applications. Overall, the clinical benefits generally outweigh the hazards of using ENMs in the oral cavity, and the latter should not prevent the responsible innovation of nanotechnology in dentistry. However, the clinical safety regulations for dental materials have not been specifically updated for ENMs, and some guidance on occupational health for practitioners is also needed. Knowledge gaps for future research include the formation of protein corona in the oral cavity, ENM diffusion through clinically relevant biofilms, and mechanistic investigations on how ENMs strengthen the tooth structure

A new class of glycomimetic drugs to prevent free fatty acid-induced endothelial dysfunction

Background: Carbohydrates play a major role in cell signaling in many biological processes. We have developed a set of glycomimetic drugs that mimic the structure of carbohydrates and represent a novel source of therapeutics for endothelial dysfunction, a key initiating factor in cardiovascular complications. Purpose: Our objective was to determine the protective effects of small molecule glycomimetics against free fatty acid­induced endothelial dysfunction, focusing on nitric oxide (NO) and oxidative stress pathways. Methods: Four glycomimetics were synthesized by the stepwise transformation of 2,5­dihydroxybenzoic acid to a range of 2,5­substituted benzoic acid derivatives, incorporating the key sulfate groups to mimic the interactions of heparan sulfate. Endothelial function was assessed using acetylcholine­induced, endotheliumdependent relaxation in mouse thoracic aortic rings using wire myography. Human umbilical vein endothelial cell (HUVEC) behavior was evaluated in the presence or absence of the free fatty acid, palmitate, with or without glycomimetics (1µM). DAF­2 and H2DCF­DA assays were used to determine nitric oxide (NO) and reactive oxygen species (ROS) production, respectively. Lipid peroxidation colorimetric and antioxidant enzyme activity assays were also carried out. RT­PCR and western blotting were utilized to measure Akt, eNOS, Nrf­2, NQO­1 and HO­1 expression. Results: Ex vivo endothelium­dependent relaxation was significantly improved by the glycomimetics under palmitate­induced oxidative stress. In vitro studies showed that the glycomimetics protected HUVECs against the palmitate­induced oxidative stress and enhanced NO production. We demonstrate that the protective effects of pre­incubation with glycomimetics occurred via upregulation of Akt/eNOS signaling, activation of the Nrf2/ARE pathway, and suppression of ROS­induced lipid peroxidation. Conclusion: We have developed a novel set of small molecule glycomimetics that protect against free fatty acidinduced endothelial dysfunction and thus, represent a new category of therapeutic drugs to target endothelial damage, the first line of defense against cardiovascular disease

Psychosocial profile of institutionalised street children in Alexandria, Egypt: a comparative study with school children

Objective: The phenomenon of street children in Egypt constitutes a public health concern. This study aimed to investigate the characteristics of institutionalised street children in Alexandria, to compare the prevalence of substance abuse and conduct disorder between street children and school children, and to identify predictors of these mental health outcomes among street children.Methods: Institutionalised street children (n = 102) participated in a cross-sectional comparative study with a matched group of school children (n = 156). An interviewing questionnaire was used to assess demographic characteristics and substance use. Conduct disorder was measured using the Revised Ontario Child Health study scale.Results: Poverty, family breakdown, and domestic violence were the main reasons for street children having left home. Street children recorded significantly higher rates of substance use (9.8%) and conduct disorder (35.3%) compared to school children. In street children, smoking was a significant predictor of substance use and conduct disorder. Other predictors of conduct disorder included physical illness and having 5 to 7 siblings.Conclusion: Substance abuse and conduct disorder were present among institutionalisedstreet children at higher rates than school children. Absence of basic life needs and disrupted families constituted the main reasons for leaving home. Interventions at the governmental and non-governmental levels are needed

Study of the association between nailfold capillaroscopic changes and serum level of interleukin-17 in rheumatoid: a clue for emerging vaculitis

Objectives The aim of this work was to study nailfold capillaroscopic (NC) abnormalities and serum interleukin-17 (IL-17) level among rheumatoid arthritis (RA) patients and to find whether IL-17 is causally involved in the changes in the capillary vascular bed, such as autoimmune prevasculitic changes. Patients and methods The study was conducted on a group of RA Egyptian patients (n=40) who were diagnosed as having RA based on ACR criteria. Those 40 patients were further divided into two groups. Group 1 included RA patients with clinical signs of skin vasculitis and NC changes (n=6). Group 2 included RA patients with no clinical signs of skin vasculitis and no NC changes (n=34). All patients were subjected to demographic data collection, clinical examination, disease activity score 28 calculation, laboratory measurement (including erythrocyte sedimentation rate, C-reactive protein, rheumatoid factor, antinuclear antibody, antineutrophil cytoplasmic antibody, anti-cyclic citrullinated peptide, and IL-17) and NC examination. In addition, group 1 (n=6) was further subjected to electrophysiological evaluation using peripheral nerve conduction studies to determine the effect of vasculitis on the peripheral nerves. Results IL-17 level and NC changes showed a significant association in RA vasculitis patients. Conclusion Elevated levels of serum IL-17 and characteristic NC changes raise their importance in the detection of preclinical rheumatoid vasculitis

A morpho-etiological description of congenital limb anomalies.

<b>Background: </b>Limb anomalies rank behind congenital heart disease as the most common birth defects observed in infants. More than 50 classifications for limb anomalies based on morphology and osseous anatomy have been drafted over the past 150 years. The present work aims to provide a concise summary of the most common congenital limb anomalies on a morpho-etiological basis. <b>Patients and Methods: </b>In a retrospective study, 70 newborns with anomalies of the upper and/or lower limbs were ascertained through clinical examination, chromosomal analysis, skeletal surveys and other relevant investigations. <b>Results: </b>Fetal causes of limb anomalies represented 55.8&#x0025; of the cases in the form of 9 cases (12.9&#x0025;) with chromosomal aberrations (trisomy 13, 18 and 21, duplication 13q and deletion 22q) and 30 cases (42.9&#x0025;) with single gene disorders. An environmental etiology for limb anomalies was diagnosed in 11 cases (15.7&#x0025;) as amniotic band disruption, monozygotic twin with abnormal circulation, vascular disruption (Poland sequence, sirenomelia and general vascular disruption) and an infant with a diabetic mother. Twenty cases (28.5&#x0025;) had limb anomalies as part of sporadic syndromes of unknown etiology. <b>Conclusions: </b>The morpho-etiological work-up of limb anomalies adopted in the present study is valuable for detecting the cause of the anomaly and is crucial for its prevention. Prevention can be achieved by proper genetic counseling, which includes recurrence risk estimation and prenatal diagnosis