The impact of the COVID-19 pandemic on the dental-maxillofacial emergency service of a German university hospital in the year 2020.

OBJECTIVES: COVID-19 is considered one of the most serious pandemic in history and has posed major challenges to the world's health care. Dentistry and oral and maxillofacial surgery (CMFS) are particularly affected due to direct exposure to the respiratory tract, as the reservoir of SARS-CoV-2. In this study, the impact of the COVID-19-pandemic on a dental and CMFS emergency services in Germany in 2020 was first time investigated and correlated with governmental restriction measures in public life. MATERIALS AND METHODS: Epidemiological data of a German University Hospital were analysed from a total of 8386 patients in 2019 and 2020. Parameters included information on demographics, time, weekday and reason for presentation, as well as diagnosis and therapy performed. Data from 2020 were compared with those from 2019, taking into account the nationwide periods of public life restrictions. RESULTS: In 2020, 22% fewer patients presented via dental and CMFS emergency service. In a monthly comparison, there were negative peaks of up to - 41% in November, but also a plus of 26% in July. The largest decreases were recorded during the lockdown periods in spring (- 33%) and winter (- 39%). Further, a threefold increase in actual emergencies and inpatient admissions revealed during these time periods (p < 0.001). CONCLUSIONS: COVID-19 pandemic had a significant impact on the dental and CMFS emergency service in 2020 resulting in more severe cases. CLINICAL RELEVANCE: This study underlines the importance of maintaining an emergency service system and basic outpatient care in these specialities, which requires uniform recommendations from the medical-dental societies and politics.

Organic nitrate chemistry and its implications for nitrogen budgets in an isoprene- and monoterpene-rich atmosphere: constraints from aircraft (SEAC4RS) and ground-based (SOAS) observations in the Southeast US.

Formation of organic nitrates (RONO2) during oxidation of biogenic volatile organic compounds (BVOCs: isoprene, monoterpenes) is a significant loss pathway for atmospheric nitrogen oxide radicals (NOx), but the chemistry of RONO2 formation and degradation remains uncertain. Here we implement a new BVOC oxidation mechanism (including updated isoprene chemistry, new monoterpene chemistry, and particle uptake of RONO2) in the GEOS-Chem global chemical transport model with ∼25 × 25 km2 resolution over North America. We evaluate the model using aircraft (SEAC4RS) and ground-based (SOAS) observations of NOx, BVOCs, and RONO2 from the Southeast US in summer 2013. The updated simulation successfully reproduces the concentrations of individual gas- and particle-phase RONO2 species measured during the campaigns. Gas-phase isoprene nitrates account for 25-50% of observed RONO2 in surface air, and we find that another 10% is contributed by gas-phase monoterpene nitrates. Observations in the free troposphere show an important contribution from long-lived nitrates derived from anthropogenic VOCs. During both campaigns, at least 10% of observed boundary layer RONO2 were in the particle phase. We find that aerosol uptake followed by hydrolysis to HNO3 accounts for 60% of simulated gas-phase RONO2 loss in the boundary layer. Other losses are 20% by photolysis to recycle NOx and 15% by dry deposition. RONO2 production accounts for 20% of the net regional NOx sink in the Southeast US in summer, limited by the spatial segregation between BVOC and NOx emissions. This segregation implies that RONO2 production will remain a minor sink for NOx in the Southeast US in the future even as NOx emissions continue to decline.

Effect of ionizing radiation on polymer brackets.

OBJECTIVE: The purpose of this study was to investigate whether the mechanical properties of polymer brackets can be improved without discoloration by electron beam (EB) irradiation applied with a Rhodotron electron accelerator using standard high-energy parameters including a 10 MV acceleration voltage and 100 kGy of energy. We analyzed polymer samples and several commercially available brackets. MATERIALS AND METHODS: The first group included three polymeric base materials (polyoxymethylene, polycarbonate, polyurethane) currently used in various bracket systems. The second group included five bracket types, three of which are on the market (Aesthetik-Line and Brillant by Forestadent; Envision by Ortho Organizers) while the other two were experimental brackets containing urethane dimethacrylate as a monomer matrix and functional silane-treated SiO2 fillers with a filler content of 10 or 40 vol%. Each category included 40 specimens previously irradiated by a commercial provider (Beta-Gamma-Service, Bruchsal, Germany) and another 40 nonirradiated controls. The polymer specimens were analyzed for fracture toughness, Vickers hardness, and wear resistance, and the bracket specimens for Vickers hardness and color stability. The Wilcoxon-Mann-Whitney U test was used for pairwise comparison to identify significant differences (p ≤ 0.05). RESULTS: Significant increases in fracture toughness and Vickers hardness were observed in polycarbonate and polyurethane after EB irradiation, while EB irradiation of polyoxymethylene resulted in a significant decrease in these parameters. The polyurethane samples demonstrated significantly less postirradiation wear. All the commercially available brackets except for Brillant revealed significant increases in Vickers hardness. Significant discoloration was observed in all brackets after irradiation. CONCLUSION: Although our evaluation of polymer brackets revealed considerable improvements in mechanical properties after EB irradiation, this benefit was marred by very obvious discoloration. We cannot therefore recommend industrial scale EB irradiation for any polymer bracket currently on the market.

Effects of mechanical and bacterial stressors on cytokine and growth-factor expression in periodontal ligament cells.

OBJECTIVES: The goal of the study was to examine the effects of a mechanical (orthodontic force simulation by static compressive loading) and a bacterial (endotoxins from a heat-inactivated gram-negative periodontal pathogen) stressor on the expression patterns of factors that are key to regulating osteoclastogenesis and bone remodeling. MATERIALS AND METHODS: Three experimental groups were formed with fifth-passage periodontal ligament (PDL) fibroblasts treated by the static application of compressive force (2 g/cm(2)), heat-inactivated aggregatibacter actinomycetemcomitans (1 × 10(7) cells), or both of these stressors combined. Real-time polymerase chain reaction (RT-PCR) was used to study gene expression of IL-6, IL-8, COX-2, IGF-1, VEGF, and MMP-13 in the 3 groups. Protein levels of COX-2, prostaglandin E2 (PGE(2)), and IL-8 production were quantified using immunoblotting and enzyme-linked immunosorbent assay (ELISA). RESULTS: The mechanical stressor upregulated the genes of COX-2, IL-8, IGF-1, and MMP-13 in PDL fibroblasts and the bacterial stressor upregulated IL-6, IL-8, COX-2 and MMP-13. Both stressors in combination upregulated VEGF and caused COX-2 gene expression to increase further; the latter effect was also detected at the protein level and indirectly via the enhanced production of PGE(2). We noted that the posttranscriptional regulation of IL-8 was induced by the mechanical stressor and influenced by PGE(2). CONCLUSION: While mechanical-stressor application increased the gene expression of COX-2, IL-8, and VEGF in the presence of the bacterial stressor, IL-8 production was posttranscriptionally regulated by the mechanical stressor, whereas COX-2 expression correlated with enhanced production of the inflammatory tissue hormone PGE(2), which exerted a suppressive effect on endotoxin-induced IL-8 production.

The role of hypoxia in orthodontic tooth movement.

Orthodontic forces are known to have various effects on the alveolar process, such as cell deformation, inflammation, and circulatory disturbances. Each of these conditions affecting cell differentiation, cell repair, and cell migration, is driven by numerous molecular and inflammatory mediators. As a result, bone remodeling is induced, facilitating orthodontic tooth movement. However, orthodontic forces not only have cellular effects but also induce vascular changes. Orthodontic forces are known to occlude periodontal ligament vessels on the pressure side of the dental root, decreasing the blood perfusion of the tissue. This condition is accompanied by hypoxia, which is known to either affect cell proliferation or induce apoptosis, depending on the oxygen gradient. Because upregulated tissue proliferation rates are often accompanied by angiogenesis, hypoxia may be assumed to fundamentally contribute to bone remodeling processes during orthodontic treatment.

Obesity prevention in defined (high school) populations.

BACKGROUND: A challenge for the widespread dissemination of Internet-based programs designed to produce weight maintenance/loss in defined (high school) populations is to adapt them to local needs and interests, whereas demonstrating effectiveness and salience for both universal and targeted populations. OBJECTIVE: The objective of this study is to examine the feasibility of providing an inexpensive, Internet-based universal (healthy weight regulation) and targeted (weight maintenance/loss) health program to all ninth-grade students in a high school serving a lower socioecnomic status, diverse population. DESIGN: A total of 118 normal-weight and 64 overweight/obese students in the same ninth-grade class completed a baseline screen and were allocated to a healthy weight regulation program or a weight-loss maintenance program. Both groups simultaneously received a 10-week Internet-based intervention. Program implementation required minimal teacher time. Measurement included self-reported fruit, vegetable and high-fat/-calorie food consumption, self-reported change in body mass index (BMI), weight and shape concerns, as well as program engagement. RESULTS: The program was successfully implemented in nine classes, with minimal help from the investigators. There was a significant increase in self-reported consumption of fruits and vegetables (P=0.001). There was a significant reduction in self-reported BMI in the overweight/obese group (P=0.001). Students found the program helpful and engaging. There was a significant reduction in weight and shape concerns in the high-risk female students, consistent with a reduced risk for the development of an eating disorder. Providing a universal and targeted online healthy weight regulation program to ninth-grade students is feasible and inexpensive. The results suggest the program can serve as 'core' for future studies using adaptive, continuous quality-improvement designs.

Profiling type I collagen gene expression in growing mandibular structures.

We conducted a temporal gene expression analysis with type I collagen in the coronoid process, alveolar process and mandibular angle of the rat. We observed gene expression cross-sectionally across different important physiological time points in the rat postnatal life in order to observe in which developmental stage mandibular development mainly occur. This study indicates prominent type I collagen expression at day 10 postpartum in the mandibular ramus and at day 21 in the alveolar process. These findings correspond well with previously obtained data from proliferation studies in facial bone suggesting that craniofacial growth in the rat occurs mainly between days 10 and 21.

Investigations about N-aminopropyl transferases probably involved in biomineralization.

Polyamines are widespread distributed all over in living organisms. In Thalassiosira pseudonana 10 N-aminopropyl transferase like nucleotide sequences exists. It is assumed that these sequences are involved in the biomineralization of the diatom shell. The cDNA of the sequences were cloned, recombinant overexpressed and assayed with decarboxylated S-adenosylmethionine and several radioactive labelled polyamines. However, only a spermidine synthase and a thermospermine synthase were found to be enzymatically active in an in vitro assay. Both enzyme activities could be recognized in the crude extracts of Thalassiosira pseudonana and Cyclotella meneghiana. In further investigations the kinetics of the thermospermine synthase was determined and a site-specific mutagenesis of the bindig cavity of decarboxylated S-adenosylmethionine was carried out.

Evaluating the federal role in financing health-related research.

This paper considers the appropriate role for government in the support of scientific and technological progress in health care; the information the federal government needs to make well-informed decisions about its role; and the ways that federal policy toward research and development should respond to scientific advances, technology trends, and changes in the political and social environment. The principal justification for government support of research rests upon economic characteristics that lead private markets to provide inappropriate levels of research support or to supply inappropriate quantities of the products that result from research. The federal government has two basic tools for dealing with these problems: direct subsidies for research and strengthened property rights that can increase the revenues that companies receive for the products that result from research. In the coming years, the delivery system for health care will continue to undergo dramatic changes, new research opportunities will emerge at a rapid pace, and the pressure to limit discretionary federal spending will intensify. These forces make it increasingly important to improve the measurement of the costs and benefits of research and to recognize the tradeoffs among alternative policies for promoting innovation in health care.

[Measurement of esophageal pH during 24 hours in children. Preliminary report]. / Medición del pH esofágico durante 24 horas en niños. Reporte preliminar.

A preliminary report is presented regarding the 24 hours continuous pH monitoring of 40 patients from 1 month to 19 years of age with clinical features of gastro-esophageal reflux confirmed by at least one of the diagnostic methods utilized (radiology, endoscopy, esophageal biopsy). The equipment used was a MIC GASTROGRAPH with 1.2 and 3 mm catheters according to age and using the methodology suggested by ESPGAN. Patients with reflux index of more than 10% had all other pH indexes and other diagnostic methods abnormal. The area of the curve below pH 4 correlated directly with the presence of esophagitis. Patients with post history of esophageal atresia and caustic esophagitis had marked alterations of pH. PH monitoring with the modern methodology currently available is of great help to quantify severity of acid reflux, to distinguish between physiologic pathologic reflux and to decide treatment.

Effect of three dietary treatments upon the histopathology of jejunal biopsies of children with chronic diarrhea.

Thirty two children with chronic diarrhea of unknown etiology were prospectively investigated in a special hospitalization unit. They were all under 5 percentile for weight/height (NCHS). They had no edema and their age range was between three and eighteen months. The patients were given cow's milk and following the first jejunal biopsy they were fed one of three different diets as their only intake for a period of 15 days. The diets consisted of cow's milk and of two semi-elemental diets with different carbohydrate compositions. A second biopsy was taken at the conclusion of the specific diet. The jejunal biopsies were taken with a Crosby capsule just after the duodenal-jejunal junction and were analyzed by light microscopy. The morphological changes before and after 15 days of dietary treatment were evaluated. The children on semi-elemental diets showed a marked reduction of the number of interepithelial lymphocytes, and of lymphocytes in lamina propria. The infants on cow's milk showed no improvement. Our results suggest that cow's milk could be the cause of the persistent mucosal alterations observed in these infants.