Biomodification of existing hard tissue structures, specifically tooth dentin, is an innovative approach proposed to improve the biomechanical and biochemical properties of tissue for potential preventive or reparative/regenerative therapies. The objectives of the study were to systematically characterize dentin matrices biomodified by proanthocyanidin-rich grape seed extract (GSE) and glutaraldehyde (GD). Changes to the biochemistry and biomechanical properties were assessed by several assays to investigate the degree of interactions, biodegradation rates, proteoglycans interaction, and effect of collagen fibril orientation and environmental conditions on the tensile properties. The highest degree of agent-dentin interaction was observed with GSE which exhibited the highest denaturation temperature, regardless of the agent concentration. Biodegradation rates remarkably decreased following biomodification of dentin matrices after 24hs collagenase digestion. A significant decreased in the proteoglycans content of GSE treated samples was observed using a micro-assay for glycosaminoglycans and histological electron microscopy, while no changes were observed for GD and control. Tensile strength properties of GD biomodified dentin matrices were affected by dentin tubule orientation, most likely due to the orientation of the collagen fibrils. Higher and/or increased stability of the tensile properties of GD and GSE-treated samples were observed following exposure to collagenase and 8 month water storage. Biomodification of dentin matrices using chemical agents not only affects the collagen biochemistry; it also involves interaction with proteoglycans. Tissue biomodifiers interact differently with dentin matrices and may provide the tissue with enhanced preventive and restorative/reparative abilities.
Degradation of the adhesive interface contributes to the failure of resin composite restorations. The hydrophilicity of the dentin matrix during and after bonding procedures may result in an adhesive interface that is more prone to degradation over time. This study assessed the effect of chemical modification of dentin matrix on the wettability and the long-term reduced modulus of elasticity (Er) of the adhesive interfaces. Human molars were divided into groups according to the priming solutions: distilled water (control), 6.5% Proanthocyanidin-rich grape seed extract (PACs), 5.75% 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride/1.4% n-hydroxysuccinimide (EDC/NHS) and 5% Glutaraldehyde (GA). The water-surface contact angle was verified before and after chemical modification of the dentin matrix. The demineralized dentin surface was treated with the priming solutions and restored with One Step Plus (OS) and Single Bond Plus (SB) and resin composite. The Er of the adhesive, hybrid layer and underlying dentin was evaluated after 24 h and 30 months in artificial saliva. The dentin hydrophilicity significantly decreased after application of the priming solutions. Aging significantly decreased the Er in the hybrid layer and underlying dentin of control groups. The Er of GA groups remained stable over time at the hybrid layer and underlying dentin. Significant higher Er was observed for PACs and EDC/NHS groups at the hybrid layer after 24 h. The decreased hydrophilicity of the modified dentin matrix likely influence the immediate mechanical properties of the hybrid layer. Dentin biomodification prevented substantial aging at the hybrid layer and underlying dentin after 30 months storage.
The aim of this study was to evaluate the diagnostic accuracy of a neuromonitoring protocol—the Abu Dhabi Neural Mapping protocol (ADNM)—using a new device, Nim-Vital™, during minimally invasive thyroidectomy in the early identification of non-recurrent laryngeal nerve (n-RLN) problems and the preservation of its function. Method: Patients with thyroid disorders that required thyroid resection, who were admitted to the Department of Surgery at Burjeel Hospital, Abu Dhabi, between January and July 2022, were included in the study. The data were extracted from a prospective database and were analyzed retrospectively. All nerves at risk were identified and exposed at seven precisely defined anatomical points, with strict adherence to the intraoperative technical steps of neuromonitoring. These were sequentially applied to the vagal nerve (VN), the superior laryngeal nerve (SLN), and the recurrent laryngeal nerve (RLN). In the next step after the creation of the skin-platysma flap, the strap muscle’s lateral border was moved from the medial limb of the sternocleidomastoid without using any electrical device and without any manipulation of the thyroid gland. The VN was exposed in the carotid sheath and then stimulated using a monopolar probe at a precisely defined point above the clavicle, using anatomical landmarks. Results: In total, 136 women with a mean age of 40 years (range 18–74) and 36 men with a mean age of 42 (range 21–66), demonstrating 270 nerves at risk, were included in the analysis. Indications for surgery were malignancy in 70 cases, toxic goiter/Graves in 23 cases, retrosternal goiter in 21, and symptomatic multinodular goiter in 64 cases. Of these, 100 patients received a total thyroidectomy, 46 received a right lobectomy, and 24 received a left lobectomy only. For a total thyroidectomy, the median skin-to-skin surgery duration was 52 min (range 24–104 min) and the median hospital stay was 2 days (range 1–4 days). In 4 cases (4/146; 2.74%) the pre-dissection stimulation of the vagal nerve (VN1) at the ADNM’s precisely defined point did not create any signal or proper EMG-curve that indicated the existence of the non-RLN. Proximal dissection of the right VN at a precisely defined point by the ADNM’s level of incisura of the larynx created a positive signal. The separation point of the right non-RLN from the VN was discovered in all four patients. The postoperative video-laryngoscopy confirmed bilateral mobile vocal cords in all cases. Conclusions: Following the ADNM protocol during thyroid surgery minimizes the risk of a non-laryngeal nerve injury and prevents voice dysfunction.
Background Investigate whether estradiol differs between premenopausal women with and without type 1 diabetes, and whether levels are associated with such factors as age, reproductive history, or diabetes management. Methods Estradiol in premenopausal women with type 1 diabetes (n=89; age=18-50 years; duration=13-18 years) and age/race-matched controls without diabetes (n=76) was collected during a cross-sectional ancillary study of the Wisconsin Diabetes Registry Study, a population-based incident cohort. Total and bioavailable estradiol and SHBG were compared using multivariable regression (e.g., adjusting for reproductive history). Results Adjusted mean total and bioavailable estradiol did not differ overall by diabetes status (p≥0.74), while adjusted mean SHBG was higher in type 1 diabetes women (p=0.02). However, only in women with type 1 diabetes and not controls (interaction p=0.0005), total estradiol was positively associated with duration of reproductive years with unsuppressed ovarian function (UnsuppOvFx=years since menarche minus years on hormonal contraceptives/pregnant/breastfeeding). Stratifying into ≤ or > the median 9 years duration of UnsuppOvFx, compared to controls, women with type 1 diabetes had significantly lower total estradiol in ≤9 years group (β=−43.2 pg/ml [−158.6 pmol/L], p=0.04), and significantly higher total estradiol in >9 years group (β=53.9 pg/ml [197.9 pmol/L], p=0.04). Results remained consistent during additional statistical adjustments and sensitivity analyses. Conclusions Compared to controls, estradiol may be lower in women with type 1 diabetes with shorter duration, and higher with longer duration, of UnsuppOvFx. Given the potential effects of insulin on ovarian function, estradiol production may vary across the lifespan for women with type 1 diabetes.
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