Molecular insights into hypomineralized enamel

Hypomineralized enamel may be found in connection with the condition molar incisor hypomineralization (MIH), which has a prevalence of around 15% in most parts of the world. Molar incisor hypomineralization is associated with extensive objective and subjective problems, such as hypersensitivity of the affected teeth, enamel breakdown, and problems with retention of restorations. The etiology behind MIH has not yet been elucidated, but a number of possible factors, which affect the same or different functions of ameloblasts during their different stages of maturation, have been suggested. The aim of this study was to utilize multi‐nuclear, solid‐state nuclear magnetic resonance (ss‐NMR) and time‐of‐flight secondary ion mass spectroscopy (ToF‐SIMS) to elucidate any differences, at a molecular level, between enamel powder prepared from normal, healthy teeth and enamel powder prepared from teeth diagnosed with MIH. ³¹P and ²³Na ss‐NMR confirmed the presence of and two different Na⁺ sites in hypomineralized enamel, suggesting a heterogeneous chemical composition. The content of organic components was higher in hypomineralized enamel, as shown by both ¹³C ss‐NMR and ToF‐SIMS, indicating the presence of higher numbers of proteins and phospholipids. The interplay between both is necessary for the formation and mineralization of enamel, which might be disturbed or halted in hypomineralized enamel.     

Is there a correlation between arthroscopic findings and the clinical signs and symptoms of patients with internal derangement of the temporomandibular joint? A prospective study

The aim of this study was to evaluate the correlation between clinical signs and symptoms of patients with internal derangement of the temporomandibular joint (TMJ) and arthroscopic findings. The study included a sample of 67 patients who underwent TMJ arthroscopy. The variables evaluated were the arthroscopic findings of synovitis, chondromalacia, adhesion, and roofing. The Spearman correlation index was used to correlate these findings with the clinical signs and symptoms of internal derangement of the TMJ, namely maximum mouth opening, pain (visual analogue scale, VAS), and the Wilkes classification. The mean age of the population was 36.16 years, and 85% were female. There was a correlation between pain and synovitis (P = 0.0029, r = 0.3508), between mouth opening limitation and the amount of adhesion (P = 0.0004, r = ?0.4084), and between Wilkes classification and the presence of chondromalacia and disc displacement (P = 0.001, r = 0.374 and P = 0.0045, r = ?0.3357, respectively). No correlation was found between age and the presence of chondromalacia (P = 0.3444, r = 0.1147). Patients who had worse pain symptoms had more advanced stages of synovitis, and the increased presence of adhesions was associated with limitations in mouth opening. Furthermore, those with more advanced Wilkes stages had greater disc displacement and more severe stages of chondromalacia.     

Cancer league actions against sunbed use for skin cancer prevention

The incidence of non‐melanoma and melanoma skin cancer has been rising in Europe. Although the World Health Organization's International Agency for Research on Cancer has since 2009 classified sunbeds as a Group 1 carcinogen, sunbed use, especially by those under the age of 18, continues to be a concern. As the only platform for cancer leagues in Europe, the Association of European Cancer Leagues decided to explore interest and actions by its member leagues at the national level against sunbed use, to share experiences and to provide background information on possible future collective actions at the EU level.     

Where is the brain in all of this?

Clinical Autonomic Research -     

The difficulty of diagnosing NCSE in clinical practice; external validation of the Salzburg criteria

To improve the diagnostic accuracy of electroencephalography (EEG) criteria for nonconvulsive status epilepticus (NCSE), external validation of the recently proposed Salzburg criteria is paramount. We performed an external, retrospective, diagnostic accuracy study of the Salzburg criteria, using EEG recordings from patients with and without a clinical suspicion of having NCSE. Of the 191 EEG recordings, 12 (12%) was classified as an NCSE according to the reference standard. In the validation cohort, sensitivity was 67% and specificity was 89%. The positive predictive value was 47% and the negative predictive value was 95%. Ten patients in the control group (n = 93) were false positive, resulting in a specificity of 89.2%. The interrater agreement between the reference standards and between the scorers of the Salzburg criteria was moderate; disagreement occurred mainly in patients with an epileptic encephalopathy. The Salzburg criteria showed a lower diagnostic accuracy in our external validation study than in the original design, suggesting that they cannot replace the current practice of careful weighing of both clinical and EEG information on an individual basis.     

Slower Skeletal Muscle Oxygenation Kinetics in Adults With Complex Congenital Heart Disease

BackgroundAdults with complex congenital heart disease (CHD) show reduced aerobic exercise capacity and impaired skeletal muscle function compared with healthy peers. Peripheral muscle factors are presumed to be important contributors to the aerobic capacity, but the mechanisms are poorly understood. The aim of the present study was to investigate differences between adults with CHD and controls in muscle oxygenation kinetics at rest, and during and after exercise.MethodsSeventy-four patients with complex CHD (mean age 35.6 ± 14.3 years, female n = 22) were recruited. Seventy-four age- and sex-matched subjects were recruited as controls. Muscle oxygenation was successfully determined on the anterior portion of the deltoid muscle using near-infrared spectroscopy in 65 patients and 71 controls. Measurements were made at rest, during isotonic shoulder flexions (0-90°) to exhaustion, and during recovery.ResultsThe patients with CHD performed fewer shoulder flexions (40 ± 17 vs 69 ± 40; P < 0.001), had lower muscle oxygen saturation (StO₂) at rest (58 ± 18% vs 69 ± 18%; P < 0.001), slower desaturation rate at exercise onset (?9.7 ± 5.9 vs ?15.1 ± 6.5% StO₂ × 3.5 s^?1, P <0.001), and slower resaturation rate post exercise (4.0 ± 2.7 vs 5.4 ± 3.6% StO₂ × 3.5 s^?1; P = 0.009) compared with the controls.ConclusionsIn comparison with age- and sex-matched controls, adults with complex CHD had slower oxygenation kinetics. This altered skeletal muscle metabolism might contribute to the impaired skeletal muscle endurance capacity shown and thereby also to the reduced aerobic capacity in this population.     

Systemic disruption of the homeostasis of transfer RNA isopentenyltransferase causes growth and development abnormalities in Bombyx mori

Isopentenylation at A37 (i⁶A37) of some transfer RNAs (tRNAs) plays a vital role in regulating the efficiency and fidelity of protein synthesis. However, whether insects, which are well known for their highly efficient protein synthesis machinery, employ this regulatory mechanism remains uninvestigated. In the current study, a candidate tRNA isopentenyltransferase (IPT) gene with three alternative splicing isoforms (BmIPT1–BmIPT3) was identified in Bombyx mori (silkworm). Only BmIPT1 could complement a yeast mutant lacking tRNA IPT. Phylogenetic analysis showed that silkworm tRNA IPT is conserved in the Lepidoptera. BmIPT was expressed in all B. mori tissues and organs that were investigated, but was expressed at a significantly higher level in silk glands of the fourth instar compared to the first day of the fifth instar. Interestingly, BmIPT was expressed at a significantly higher level in the domesticated silkworm, B. mori, than in wild Bombyx mandarina in multiple tissues and organs. Knock‐down of BmIPT by RNA interference caused severe abnormalities in silk spinning and metamorphosis. Constitutive overexpression of BmIPT1 using a cytoplasmic actin 4 promoter in B. mori raised its messenger RNA level more than sixfold compared with nontransgenic insects and led to significant decreases in the body weight and cocoon shell ratio. Together, these results confirm the first functional tRNA IPT in insects and show that a suitable expression level of tRNA IPT is vital for silk spinning, normal growth, and metamorphosis. Thus, i⁶A modification at position A37 in tRNA probably plays an important role in B. mori protein synthesis.