Glycation of nail proteins : from basic biochemical findings to a representative marker for diabetic glycation-associated target organ damage

Background : Although assessment of glycated nail proteins may be a useful marker for monitoring of diabetes, their nature and formation are still poorly understood. Besides a detailed anatomical analysis of keratin glycation, the usefulness of glycated nail protein assessment for monitoring diabetic complications was investigated. Methods : 216 patients (94 males, 122 females; mean age +/- standard deviation: 75.0 +/- 8.7 years) were enrolled. Glycation of nail and eye lens proteins was assessed using a photometric nitroblue tetrazolium-based assay. Following chromatographic separation of extracted nail proteins, binding and nonbinding fractions were analyzed using one-dimensional gel electrophoresis. Using a hand piece containing a latch-type-bur, a meticulous cutting of the nail plate into superficial and deep layers was performed, followed by a differential analysis of fructosamine. Results : Using SDS PAGE, four and two bands were identified among the nonglycated and glycated nail fraction respectively. Significantly lower fructosamine concentrations were found in the superficial nail layer (mean: 2.16 +/- 1.37 mu mol/g nails) in comparison with the deep layer (mean: 4.36 +/- 2.55 mu mol/g nails) (P<0.05). A significant higher amount of glycated eye lens proteins was found in diabetes mellitus patients (mean: 3.80 +/- 1.57 mu mol/g eye lens) in comparison with nondiabetics (mean: 3.35 +/- 1.34 mu mol/g eye lens) (P<0.05). A marked correlation was found between glycated nail and glycated eye lens proteins [y (glycated nail proteins) = 0.39 + 0.99 x (eye lens glycated proteins); r(2) = 0.58, P<0.001]. The concentration of glycated eye lens proteins and the HbA1c level were found to be predictors of the concentration of glycated nail proteins. Conclusions : Glycation of nail proteins takes place in the deep layer of finger nails, which is in close contact with blood vessels and interstitial fluid. Glycation of nail proteins can be regarded as a representative marker for diabetic glycation-associated target organ damage

Analysis of protein glycation in human fingernail clippings with near-infrared (NIR) spectroscopy as an alternative technique for the diagnosis of diabetes mellitus

BACKGROUND: Glycated keratin allows the monitoring of average tissue glucose exposure over previous weeks. In the present study, we wanted to explore if near-infrared (NIR) spectroscopy could be used as a non-invasive diagnostic tool for assessing glycation in diabetes mellitus. METHODS: A total of 52 patients with diabetes mellitus and 107 healthy subjects were enrolled in this study. A limited number (n=21) of nails of healthy subjects were glycated in vitro with 0.278 mol/L, 0.556 mol/L and 0.833 mol/L glucose solution to study the effect of glucose on the nail spectrum. Consequently, the nail clippings of the patients were analyzed using a Thermo Fisher Antaris II Near-IR Analyzer Spectrometer and near infrared (NIR) chemical imaging. Spectral classification (patients with diabetes mellitus vs. healthy subjects) was performed using partial least square discriminant analysis (PLS-DA). RESULTS: In vitro glycation resulted in peak sharpening between 4300 and 4400 cm-1 and spectral variations at 5270 cm-1 and between 6600 and 7500 cm-1. Similar regions encountered spectral deviations during analysis of the patients' nails. Optimization of the spectral collection parameters was necessary in order to distinguish a large dataset. Spectra had to be collected at 16 cm-1, 128 scans, region 4000-7500 cm-1. Using standard normal variate, Savitsky-Golay smoothing (7 points) and first derivative preprocessing allowed for the prediction of the test set with 100% correct assignments utilizing a PLS-DA model. CONCLUSIONS: Analysis of protein glycation in human fingernail clippings with NIR spectroscopy could be an alternative affordable technique for the diagnosis of diabetes mellitus

A Tissue Section-Based Near-Infrared Spectroscopical Analysis of Salivary Gland Tumors

SGTs vary in histological behavior. Mucins, a major component in salivary glands, consist of a glycosylated and sialylated protein core. Rapid evolutions in glycobiology have demonstrated the important role of glycoproteins in cancer development. NIR spectroscopy is a method for the biochemical analysis of substrates. NIR spectra can be analyzed using specific chemometrics. Our aim was to explore the diagnostic possibilities of NIR spectroscopy in SGTs. 238 Hematoxylin and Eosine stained (H&amp;E) SGT tissue sections were examined using NIR spectroscopy. 45 deparaffinized tissue sections were treated with neuraminidase to identify wavelengths in the NIR spectrum related to sialylation. NIR spectra were analyzed with chemometrics. NIR spectra could distinguish malignant SGTs from controls and benign SGTs. Prediction models based on the entire spectral range resulted in a 73.1% accurate classification of malignant SGTs and controls, while, based on neuraminidase experimental spectral peak differences (1436 nm; 1713 nm; 1783 nm; 1924 nm; 2032 nm; 2064 nm; 2178 nm; 2216 nm), an improved overall correct classification rate of 91.9% was obtained between healthy subjects and malignant tumors. H&amp;E tissue section-based NIR spectroscopy can identify malignant SGTs from controls, promising an alternative method in the diagnosis of SGTs

Clinical outcomes and cost-effectiveness of superficial parotidectomy versus extracapsular dissection of the parotid gland : a single-centre retrospective study of 161 patients

Improvements in preoperative diagnostics and intraoperative techniques have made the surgical excision of benign parotid gland tumours less invasive. Extracapsular dissection (ECD) has become more popular in comparison to superficial parotidectomy (SP), the gold standard. Although clinical outcomes have been reported, reports on cost-effectiveness are limited. The aim of this retrospective study was to analyse the surgical outcomes and cost-effectiveness of ECD versus SP in benign parotid tumour surgery. A retrospective cohort of 161 patients treated between 2012 and 2020 was collected. Data concerning demographics, clinical outcomes, and cost-efficiency were recorded. Analysis of the 161 unilateral parotidectomy cases (59 SP, 102 ECD) showed a significantly longer operation time, anaesthesia time, and length of stay for SP patients (all P < 0.001). Regarding postoperative complications, transient facial nerve weakness (P < 0.001) and haematoma formation (P = 0.016) were more prevalent in the SP patients. The frequency of positive margins was lower for SP (P = 0.037). No case of recurrence was identified with either technique. ECD showed excellent clinical outcomes as well as a reduction in complications when compared to SP. ECD is a viable alternative for superficial benign parotid gland tumours after thorough preoperative clinical, pathological, and radiological examination. The reduction in operation, anaesthesia, and hospitalization times with ECD is likely to result in a gain in cost-effectiveness

Optimized 3D virtually planned intermediate splints for bimaxillary orthognathic surgery: A clinical validation study in 20 patients

Orthognathic surgery is indicated for the treatment of significant skeletal malocclusions and facial dysmorphosis. Recent technological developments allow surgeons to virtually plan the orthognathic jaw movements. When producing intermediate splints, overlap between the upper and lower dentitions can occur. Autorotation of the mandible is often used as a solution for this problem. The purpose of this study was to present an optimized approach to fabricate digital intermediate splints based on the use of a scanned thick wax bite to overcome dental overlap during planning. Twenty patients (9 males and 11 females) undergoing bimaxillary orthognathic surgery participated in this prospective study. Planning of the maxillary movements was conducted by the same surgeon. The thick wax bite was scanned using an intraoral scanner and a special CBCT protocol. The fabrication of the intermediate splints was done by means of conventional model surgery and virtual 3D planning-printing. The splints were clinically assessed by comparing the digitally printed intermediate splints to the corresponding conventional set-up which served as the clinical standard. Moreover, reproducibility and comparison tests between the scanned wax bites were implemented. The root mean square (RMS) for the reproducibility and comparison tests was respectively 0,15 mm (SD 0,24 mm) and 0,19 mm (SD 0,08 mm). 19 out of the 20 intermediate digitally 3D printed splints were clinically accepted. This proposed protocol can be considered as an optimization to the current 3D planning protocols of bimaxillary orthognathic surgery.status: publishe

Implant Failure of Facial Prostheses: Systematic Review and Meta-Analysis

The aim of this systematic review is to evaluate craniofacial implant failure in the auricular, orbital and nasal region, including the impact of radiotherapy and evaluation of early and late implant failure