Magnesium incorporation into primary dental enamel and its effect on mechanical properties

Cross-sectional study of sound primary dental enamel revealed hardness zonation and, in parallel, significant change in the Mg content below the prismless layer. Mg content is known to play an important role in enamel apatite biomineralization, therefore, Mg ion exchange experiments were carried out on the outer surface of sound primary molars and on reference abiogenic Ca-phosphates using MgCl2 solution. Effects of Mg incorporation on crystal/particle size, ionic ratio and morphology were compared and the observed changes were explained by parallel diffusion and dissolution/reprecipitation processes. Based on depth profile analysis and high resolution electron microscopy of the Mg-exchanged dental enamel, a poorly ordered surface layer of approximately 10–15 nanometer thickness was identified. This thin layer is strongly enriched in Mg and has non-apatitic structure. Below the surface layer, the Mg content increased only moderately (up to ~3 at%) and the apatite crystal structure of enamel was preserved. As a common effect of the Mg exchanged volume, primary dental enamel exhibited about 20% increase of nanohardness, which is intrepreted by strengthening of both the thin surface layer and the region below due to the decreased crystallite size and the effect of incorporated Mg, respectively

Egy diagnosztikus kihívás: paraduodenalis pancreatitis. Két eset bemutatása = A diagnostic challenge: paraduodenal pancreatitis. Two case reports

Absztrakt: A paraduodenalis, vagy groove pancreatitis egy kevéssé ismert krónikus hasnyálmirigygyulladás-típus, mely malignitást utánozva sokszor differenciáldiagnosztikai nehézségeket okoz. Közleményünkben két esetet mutatunk be: mindkét esetben műtéti reszekcióra volt szükség a biztos diagnózishoz, az inadekvát preoperatív szövettani mintavétel és a klinikai kép miatt. A képalkotó vizsgálatok az első esetben malignitás gyanúját vetették fel, a második esetben gyomorürülési zavar indikálta a reszekciót. Irodalmi áttekintést adunk az elváltozás klinikopatológiájáról, beleértve annak epidemiológiáját, klinikai megjelenését és az alkalmazható diagnosztikus módszereket, a betegség makroszkópos és mikroszkópos patomorfológiáját. Kialakulásának háttere összetett: az alkohol patogenetikai szerepe mellett a pancreaticus ductalis rendszer anatómiai variációi, a dorsalis pancreas inkomplett involúciójából származó duodenumfali pancreasszigetek vagy az elváltozás részeként gyakran megfigyelt Brunner-mirigy-hyperplasia is szerepet játszhat a minor papilla területén jelentkező pancreasnedv-elfolyási zavarban, mely a jellegzetes lokalizációjú gyulladáshoz vezet. A legfrissebb kutatások génpolimorfizmusok hajlamosító szerepét is kimutatták a hasnyálmirigy gyulladásos folyamataiban. A paraduodenalis pancreatitis differenciáldiagnosztikájának kérdése mellett a terápiás lehetőségekről is szót ejtünk, kiemelve a sikeres elkülönítés esetén jó hatásfokkal alkalmazható konzervatív kezelés lehetőségét. Orv Hetil. 2019; 160(22): 873–879. | Abstract: The paraduodenal, or groove pancreatitis is a lesser-known type of chronic pancreatitis, often mimicking malignancy, hence resulting in serious differential diagnostic challenges. Herein we report two cases of this entity. Both required analysis of the surgical specimen in order to ensure the diagnosis due to inadequate preoperative histological sampling and a vague clinical presentation. In the first case, strong suspicion of malignancy following imaging, while in the second, severe gastric outlet stenosis indicated the resection. In our report, we give a clinicopathological summary from the literature of this entity, including its epidemiology, clinical presentation and applicable diagnostic methods as well as macroscopic and microscopic pathomorphology. The pathogenesis of this disease is complex. Beside the role of alcohol, anatomic variations of the pancreatic ductal system, pancreatic islets in duodenal wall resulting from incomplete involution of dorsal pancreas, or Brunner gland hyperplasia (often observed as part of the lesion) can all play a role in the disturbance of pancreatic fluid discharge in the minor papilla area, eventually leading to this specific localised inflammation. In addition, recent investigations revealed a susceptible role of genetic polymorphism in the persistent inflammatory disorders of the pancreas. Besides summarizing the differential diagnostic aspects, we also discuss therapeutic possibilities, underlining the conservative methods, which can be used with good efficacy after a successful identification of this entity. Orv Hetil. 2019; 160(22): 873–879

Guidelines for Ecosystem Services Based Ecotourism Strategy

The ecosystem services (ESS) based worldview understands that nature contributes to human well-being and society can operate in a way which reduces or enhances nature’s capacity to contribute to our well-being. ESS can be defined as conditions and processes through which ecosystems sustain and enrich human life. Most generally, four types of ESS are differentiated: provisioning, regulating, cultural, and supporting ESS. Tourism in general and ecotourism in particular are usually related to cultural ESS

Gradient Structural Anisotropy of Dental Enamel is Optimized for Enhanced Mechanical Behaviour

Exceptional mechanical performance of dental enamel in the harsh environment of oral cavity can be preserved on decade timescale, which is a unique property in comparison with functional nanomaterials. Hierarchic architecture of enamel, based on site-specific structural organization of apatite nanocrystals has a key role in this durability. In the present study, a novel SEM imaging based method is presented for obtaining quantitative information on enamel prism orientation in sound primary dental enamel. This missing puzzle of quantification of the hierarchical enamel structure, along with spatial mechanical and chemical mapping, shed light on the optimum anisotropic gradient behaviour of elastic modulus of dental enamel. Specifically, orientation and composition dependent contributions in both the spatially changing hardness and elastic modulus were separated. Anisotropy of the enamel’s modulus was predicted and verified by the spatial variation of average prism orientation. Based on our results we conclude that the anisotropy of modulus for the bulk enamel arises from the elastic gradient in direction normal to the enamel external surface combined with the nearly constant value of modulus in the perpendicular cross section. This behaviour results in high surface strength and additionally can be responsible to the superior durability of human enamel

Tartós protonpumpagátló kezelés hatására kialakuló masszív fundusmirigy-polyposis = Massive Fundic Gland Polyposis Caused by Chronic Proton Pump Inhibitor Therapy

Közleményünkben egy protonpumpagátló kezeléssel összefüggésben kialakult, táplálkozási nehezítettség miatt teljes gastrectomiához vezető, továbbá egy passzázszavart még nem okozó masszív fundusmirigy-polyposis esetét mutatjuk be, emellett irodalmi áttekintést adunk az elváltozás gyakoriságáról és kialakulásának hátteréről, és ennek kapcsán röviden összefoglaljuk a protonpumpagátló kezelés és egyéb makro-és mikromorfológiai gastricus eltérések esetleges kapcsolatát vizsgáló tanulmányok eredményeit. A gastrectomiához vezető masszív fundusmirigy-polyposis a tartós protonpumpagátló kezelés ritka szövődménye, saját esetünk a második közölt a világon, de a terápia elterjedtsége miatt ennek gyakoribbá válása várható. We report two cases of a massive fundic gland polyposis associated with protracted proton pump inhibitor (PPI) therapy. Both patients were females aged 51. On repeated endoscopy, the number of fundic gland polyps was inreasing steeply, and they resulted in a passage disorder. In the first case, the enormous number of polyps made endoscopic removal impossible, so the patient was treated by total gastrectomy. Although our case is the second reported one in the world, we would like to draw the attention to this rare complication of long lasting PPI therapy

Prognostic role of HPV infection in esophageal squamous cell carcinoma

Abstract Background The aims of this study were to evaluate whether HPV infection has a prognostic role in patients with esophageal squamous cell carcinoma who underwent oncological treatment and also to compare the heat shock proteins (Hsp) 90, 27 and 16.2 and growth hormone-releasing hormone receptor (GHRH-R) expression patterns of the pre-treatment tumor biopsies with the HPV status and with the oncological response. Methods Pre-treatment tumor biopsies of 74 patients with locally advanced esophageal squamous cell carcinoma were processed retrospectively. The presence of HPV was detected by chromogenic in situ hybridization. Hsp and GHRH-R expressions were determined using immunohistochemistry. Following neoadjuvant or definitive radiochemotherapy, the patients were restaged according to the Response Evaluation Criteria in Solid Tumors. The correlation between the HPV status, response to treatment and Hsp and GHRH-R expressions were evaluated. Results Fourteen (19%) patients were HPV-positive. These patients were more likely to respond poorly to multimodal therapy (71.4% were non-responders vs. 28.6% responders) and had shorter survival compared to HPV-negative patients (mean survival of 8 months vs. 11 months), although the difference was not significant. A significantly higher number of HPV-positive patients expressed Hsp 90 and 16.2 at high levels (93 and 79%, respectively) than at low levels (Chi-Square p = 0.019 and p = 0.031). Higher levels of Hsp expressions were associated with poorer response to therapy and worse overall survival. No correlation was found between GHRH-R expression and the HPV status, nor between GHRH-R expression and the treatment response of the examined samples. Conclusions We found that HPV infection was associated with poor response to oncological treatment and decreased overall survival, and therefore proved to be a negative prognostic factor in patients with esophageal squamous cell carcinoma. There was a linear correlation between levels of Hsp 90 and 16.2 expression and HPV positivity

Upregulation of the TRPA1 Ion Channel in the Gastric Mucosa after Iodoacetamide-Induced Gastritis in Rats: A Potential New Therapeutic Target

Acute gastritis is often untreatable by acid secretion-inhibiting drugs. Understanding the protective mechanisms including the role of Transient Receptor Potential Ankyrin1 (TRPA1) and Vanilloid1 (TRPV1) channels localized on capsaicin-sensitive afferents and non-neuronal structures might identify novel therapeutic approaches. Therefore, we characterized a translational gastritis model using iodoacetamide (IAA) and investigated TRPA1/V1 expressions. Wistar rats and CD1, C57Bl/6J mice were exposed to IAA-containing (0.05, 0.1, 0.2, 0.3, 0.5%) drinking water for 7 or 14 days. Body weight and water consumption were recorded daily. Macroscopic lesions were scored, qualitative histopathologic investigation was performed, TRPA1/V1 immunopositivity and mRNA expressions were measured. IAA induced a concentration-dependent weight loss and reduced water intake in both species. Hyperemia, submucosal edema, inflammatory infiltration and hemorrhagic erosions developed after 7 days, while ulcers after 14 days in rats. Trpa1 mRNA/protein expressions were upregulated at both timepoints. Meanwhile, TRPV1 immunopositivity was upregulated in the gastric corpus after 0.05% IAA ingestion, but downregulated after 0.2%, whereas Trpv1 mRNA did not change. Interestingly, no macroscopic/microscopic changes were observed in mice. These are the first data for the concentration- and duration-dependent changes in the IAA-induced gastritis in rats accompanied by TRPA1 upregulation, therefore, its therapeutic potential in gastritis should further be investigated