DIGITAL DENTISTRY AND ITS IMPACT ON ORAL HEALTH-RELATED QUALITY OF LIFE.

Over the past 50 years, digitization has gradually taken root in dentistry, starting with computer tomography in the 1970s. The most disruptive events in digital dentistry were the introduction of digital workflow and computer-aided manufacturing, which made new procedures and materials available for dental use. While the conventional lab-based workflow requires light or chemical curing under inconsistent and suboptimal conditions, computer-aided manufacturing allows for industrial-grade material, ensuring consistently high material quality. In addition, many other innovative, less disruptive, but relevant approaches have been developed in digital dentistry. These will have or already impact prevention, diagnosis, and therapy, thus impacting patients' oral health and, consequently, their oral health-related quality of life. Both software and hardware approaches attempt to maintain, restore, or optimize a patient's perceived oral health. This article outlines innovations in dentistry and their potential impact on patients' oral health-related quality of life in prevention and therapy. Furthermore, possible future developments and their potential implications are characterized.

Retrospective investigation of the 3D effects of the Carriere Motion 3D appliance using model and cephalometric superimposition.

OBJECTIVES: Carriere Motion 3D™ appliance (CMA) represents a method for molar distalization and correction of class II malocclusion. The aim was to investigate the 3D effects of the CMA by superimposing digital models and cephalometric X-rays. MATERIALS AND METHODS: We retrospectively examined 16 patients treated with CMA in combination with class II elastics. We compared digitized models and cephalometric X-rays of records taken before therapy and after the removal of CMA. The records were superimposed to assess the skeletal and dentoalveolar changes. The results of the cephalometric X-ray analysis were compared to an untreated age- and gender-matched sample. RESULTS: Class II occlusion was corrected after 11.85 ± 4.70 months by 3.45 ± 2.33 mm. The average distalization of the upper first molars was 0.96 ± 0.80 mm. The analysis of the cephalometric X-rays confirmed a distalization of the upper first molars with distal tipping and revealed a mesialization of the lower first molars of 1.91 ± 1.72 mm. Importantly, CMA resulted in a mild correction of the skeletal class II relationship (ANB: - 0.71 ± 0.77°; Wits: - 1.99 ± 1.74 mm) and a protrusion of the lower incisors (2.94 ± 2.52°). Compared to the untreated control group, there was significant distalization of the upper first molars and canines with mesialization and extrusion of the lower first molars. CONCLUSION AND CLINICAL RELEVANCE: CMA is an efficient method for treating class II malocclusions. However, the class II correction is only partially caused by a distalization of the upper molars.

Sex hormones associated with temporomandibular pain on palpation in male adolescents-Results of the epidemiologic LIFE child study.

OBJECTIVE: This study aimed to investigate whether the sex steroid precursor hormone dehydroepiandrosterone sulphate (DHEA-S), sex hormone-binding globulin (SHBG) and testosterone (TT) are associated with temporomandibular (TM) pain on palpation in male adolescents. METHODS: Out of the LIFE Child study dataset containing 1022 children and adolescents aged 10-18 years (496 males, 48.5%), we used a subsample of 273 male adolescents (mean age: 13.8 ± 2.3 years) in advanced pubertal development (PD) to analyse the association between hormones and TM pain. The Tanner scale was applied to describe the stage of PD. Pain on palpation of the temporalis and masseter muscles and the TM joints (palpation pain) was assessed using the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Serum levels of sex hormones (DHEA-S, SHBG and TT) were determined using standardised laboratory analyses. Free TT was estimated from the ratio between TT and SHBG (free androgen index[FAI]). We calculated the risk of perceived positive palpation pain for male participants as a function of hormone levels (DHEA-S, FAI) taking into account age and body mass index (BMI). RESULTS: Among more developed (Tanner stage 4-5) male adolescents, 22.7% (n = 62) reported palpation pain in the TM region. In these participants, FAI levels were approximately half that of individuals without such pain (p < .01). DHEA-S levels were about 30% lower in the pain group (p < .01). In multivariable regression analyses, the odds ratio (OR) for pain on palpation decreased to 0.75 (95% confidence interval [CI]: 0.57-0.98) per 10 units of FAI level compared to those without pain, after controlling for the effects of age and adjusted BMI. We observed the same effect for this subgroup per unit of DHEA-S serum level (OR = 0.71; 95% CI: 0.53-0.94). CONCLUSION: At subclinical lower levels of serum free TT and DHEA-S, male adolescents are more likely to report pain on standardised palpation of the masticatory muscles and/or TM joints. This finding supports the hypothesis that sex hormones may influence pain reporting.

Diagnostic criteria for temporomandibular disorders-INfORM recommendations: Comprehensive and short-form adaptations for children.

BACKGROUND: The Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) are used worldwide in adults. Until now, no adaptation for use in children has been proposed. OBJECTIVE: The aim of this study was to present comprehensive and short-form adaptations of Axis I and Axis II of the DC/TMD for adults that are appropriate for use with children in clinical and research settings. METHODS: Global Delphi studies with experts in TMDs and in pain psychology identified ways of adapting the DC/TMD for children. RESULTS: The proposed adaptation is suitable for children aged 6-9 years. Proposed changes in Axis I include (i) adapting the language of the Demographics and the Symptom Questionnaires to be developmentally appropriate for children, (ii) adding a general health questionnaire for children and one for their parents, (iii) replacing the TMD Pain Screener with the 3Q/TMD questionnaire and (iv) modifying the clinical examination protocol. Proposed changes in Axis II include (i) for the Graded Chronic Pain Scale, to be developmentally appropriate for children, (ii) adding anxiety and depression assessments that have been validated in children and (iii) adding three constructs (stress, catastrophising and sleep disorders) to assess psychosocial functioning in children. CONCLUSION: The recommended DC/TMD, including Axis I and Axis II, for children aged 6-9 years, is appropriate for use in clinical and research settings. This adapted the first version for children includes changes in Axis I and Axis II changes requiring reliability and validity testing in international settings. Official translations to different languages according to INfORM requirements will enable a worldwide dissemination and implementation.

Diagnostic criteria for temporomandibular disorders-INfORM recommendations: Comprehensive and short-form adaptations for adolescents.

BACKGROUND: The Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) for use in adults is in use worldwide. Until now, no version of this instrument for use in adolescents has been proposed. OBJECTIVE: To present comprehensive and short-form adaptations of the adult version of DC/TMD that are appropriate for use with adolescents in clinical and research settings. METHODS: International experts in TMDs and experts in pain psychology participated in a Delphi process to identify ways of adapting the DC/TMD protocol for physical and psychosocial assessment of adolescents. RESULTS: The proposed adaptation defines adolescence as ages 10-19 years. Changes in the physical diagnosis (Axis I) include (i) adapting the language of the Demographics and the Symptom Questionnaires to be developmentally appropriate for adolescents, (ii) adding two general health questionnaires, one for the adolescent patient and one for their caregivers and (iii) replacing the TMD Pain Screener with the 3Q/TMD questionnaire. Changes in the psychosocial assessment (Axis II) include (i) adapting the language of the Graded Chronic Pain Scale to be developmentally appropriate for adolescents, (ii) adding anxiety and depression assessment that have been validated for adolescents and (iii) adding three constructs (stress, catastrophizing and sleep disorders) to assess psychosocial functioning in adolescents. CONCLUSION: The recommended DC/TMD, including Axis I and Axis II for adolescents, is appropriate to use in clinical and research settings. This adapted first version for adolescents includes changes in Axis I and Axis II requiring reliability and validity testing in international settings. Official translations of the comprehensive and short-form to different languages according to INfORM requirements will enable a worldwide dissemination and implementation.

Diagnostic criteria for temporomandibular disorders in children and adolescents: An international Delphi study-Part 2-Development of Axis II.

BACKGROUND: Unlike the psychosocial assessment established for adults in the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD), a standardised psychosocial assessment for children and adolescents with TMD complaints has not yet been established. OBJECTIVES: To develop a new standardised instrument set to assess the psychosocial functioning in children and adolescents by adapting the psychosocial status and pain-related disability (Axis II) of the adult DC/TMD and by including new instruments. METHODS: A modified Delphi method was used to survey 23 international TMD experts and four international experts in pain-related psychological factors for consensus regarding assessment tools for psychosocial functioning and pain-related disability in children and adolescents. The TMD experts reviewed 29 Axis II statements at round 1, 13 at round 2 and 2 at round 3. Agreement was set at 80% for first-round consensus level and 70% for each of the second and third rounds. The psychological experts completed a complementary Delphi survey to reach a consensus on tools to use to assess more complex psychological domains in children and adolescents. For the psychological experts, the first round included 10 open-ended questions on preferred screening tools for depression, anxiety, catastrophising, sleep problems and stress in children (ages 6-9 years old) and adolescents (ages 10-19 years old) as well as on other domains suggested for investigation. In the second round, the psychological experts received a 9-item questionnaire to prioritise the suggested instruments from most to least recommended. RESULTS: The TMD experts, after three Delphi rounds, reached consensus on the changes of DC/TMD to create a form to evaluate Axis II in children and adolescents with TMD complaints. The psychological experts added tools to assess depression and anxiety, sleep disorders, catastrophising, stress and resilience. CONCLUSION: Through international expert consensus, this study adapted Axis II of the adult DC/TMD to assess psychosocial functioning and pain-related disability in children and adolescents. The adapted Axis II protocols will be validated in the target populations.

Influence of caries and molar incisor hypomineralization on oral health-related quality of life in children.

OBJECTIVES: This study was aimed to compare the impact of caries and molar incisor hypomineralization (MIH) on oral health-related quality of life (OHRQoL) in children. MATERIAL AND METHODS: A total of 528 German children aged 7 to 10 years were recruited, half affected by caries and the other half affected by MIH. Both groups were matched according to age, sex, and social status and divided into 3 categories according to severity. The German version of the Child Perceptions Questionnaire for 8- to 10 years old (CPQ-G8-10) was used to analyze the impact on OHRQoL by applying ANOVA models. RESULTS: Patients with MIH showed a mean CPQ score of 10.7 (± 9.3). This was significantly higher compared to the caries group with 8.1 (± 9.8). The score increased linearly from the low severity category to the high severity category in both groups (caries, 4.1 to 13.8; MIH, 5.2 to 17.7, respectively). CONCLUSION: With increasing severity, both clinical conditions showed a greater negative impact on OHRQoL. MIH was associated with more impairments. CLINICAL RELEVANCE: Currently, the focus in pediatric dentistry is placed on the prevention and treatment of caries. Both diseases may have a negative influence on OHRQoL. Since children perceive the impairments by MIH as worse and the prevalence is equal to that of caries, which focus might be shifted in the future.

Diagnostic criteria for temporomandibular disorders (DC/TMD) for children and adolescents: An international Delphi study-Part 1-Development of Axis I.

BACKGROUND: Since in children and adolescence prevalence is assessed mainly on self-reported or proxy-reported signs and symptoms; there is a need to develop a more comprehensive standardised process for the collection of clinical information and the diagnosis of TMD in these populations. OBJECTIVE: To develop new instruments and to adapt the diagnostic criteria for temporomandibular disorders (DC/TMD) for the evaluation of TMD in children and adolescents. METHOD: A modified Delphi method was used to seek international consensus among TMD experts. Fourteen clinicians and researchers in the field of oro-facial pain and TMD worldwide were invited to participate in a workshop initiated by the International Network for Orofacial Pain and Related Disorders Methodology (INfORM scientific network) at the General Session of the International Association for Dental Research (IADR, London 2018), as the first step in the Delphi process. Participants discussed the protocols required to make physical diagnoses included in the Axis I of the DC/TMD. Thereafter, nine experts in the field were added, and the first Delphi round was created. This survey included 60 statements for Axis I, and the experts were asked to respond to each statement on a five-item Likert scale ranging from 'Strongly disagree' to 'Strongly agree'. Consensus level was set at 80% agreement for the first round, and at 70% for the next. RESULTS: After three rounds of the Delphi process, a consensus among TMD experts was achieved and two adapted DC/TMD protocols for Axis I physical diagnoses for children and adolescents were developed. CONCLUSION: Through international consensus among TMD experts, this study adapted the Axis I of the DC/TMD for use in evaluating TMD in children and adolescents.

Prevalence of anamnestic symptoms and clinical signs of temporomandibular disorders in adolescents-Results of the epidemiologic LIFE Child Study.

BACKGROUND: Prevalence values for symptoms and signs of temporomandibular disorders (TMD) in adolescents vary within the literature due to differences in set-ups of examination protocols. OBJECTIVES: The objective was to present prevalence values for symptoms and signs of TMD in German adolescents that were observed within a standardised examination. Prevalence values comparing gender or pubertal status should be investigated. METHODS: A cross-sectional sample of the LIFE Child Study aged 10 to 18 was examined. A questionnaire gathering anamnestic symptoms of TMD was completed, and an examination according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) was performed by trained dentists. Pubertal status according to Tanner stages was documented. Descriptive statistics, Mann-Whitney U and Wilcoxon signed-rank tests were performed. RESULTS: A total of 1.116 participants (mean age 12.9 years, 51.4% female) were consecutively recruited. Most prevalent anamnestic symptoms were headaches (55.7%) and temporomandibular joint (TMJ) sounds (17.6%). The major clinical sign was TMJ sounds (31.9%). Both the examination of muscles or TMJs showed that pain to palpation was statistically significantly higher than familiar pain (P < .001). Gender comparisons revealed higher prevalence values and an increase in TMD symptoms and signs during pubertal development in females. CONCLUSION: The prevalence of self-reported headaches, as well as anamnestic and clinical TMJ sounds, was high in German adolescents. Prevalence values for pain to palpation and familiar pain obtained relevant differences. Considering the DC/TMD, females are more affected by TMD signs and symptoms that increase during pubertal development, than male adolescents.

Stress-related hormones in association with periodontal condition in adolescents-results of the epidemiologic LIFE Child study.

OBJECTIVES: The aim of this study was to investigate the associations between blood levels of stress-related hormones and early signs of periodontal disease in children and adolescents. MATERIALS AND METHODS: Within the LIFE (Leipzig research center for civilization diseases) Child study, 498 adolescents (10 to 18 years) were included. Early signs of periodontal inflammation were measured by probing depth (PD) at six index teeth (16, 11, 26, 36, 31, 46). Blood levels of stress-related hormones (cortisol, dehydroepiandosterone-sulfate [DHEA-S]) and, additionally interleukine-6 (IL-6) were measured. Socioeconomic status, oral hygiene, orthodontic appliances, and nutritional status, recorded by body-mass-index-standard-deviation-score (BMI-SDS), were considered as confounding factors. Additionally, in 98 participants, an oral chairside active matrix metalloproteinase-8 (aMMP-8) test was performed. Statistical tests are the Mann-Whitney U tests, chi-squared tests and multivariate logistic regression model. RESULTS: IL-6, BMI-SDS as well as positive aMMP-8 test result were significantly associated with maximum PD > 3 mm (p < 0.05). However, no statistically significant associations between stress-related hormones (cortisol and DHEA-S) and presence of maximum PD > 3 mm were found (p > 0.05). Higher DHEA-S and BMI were associated with positive aMMP-8 result, even after adjusting for age and gender (p = 0.027, padj = 0.026). CONCLUSION: The results reveal no associations between PD and stress-related hormones cortisol and DHEA-S. aMMP-8 test result might be associated with DHEA-S level. Nutritional status seems to influence periodontal disease in adolescents. CLINICAL RELEVANCE: DHEA-S and BMI-SDS show associations with early signs of periodontal disease in adolescents aged 10 to 18 years. This association should be confirmed by the investigation of high-risk groups.

[Socioeconomic Gradients in Dental Care Accessibility in Germany]. / Sozioökonomische Gradienten bei der Inanspruchnahme zahnärztlicher Leistungen in Deutschland.

The aim of this study was to determine whether dental care accessibility in Germany from 2002 to 2009 was linked to socioeconomic status (SES) or household net income (HHN). Analysis was based upon a nation-wide cross-sectional survey of German adults from 18 to 79 years (mean 49.1 years; 55% females) which was conducted by the "Bertelsmann Gesundheitsmonitor" from 2002-2009. Patients in Germany visit the dentist 2.4 times per year independently of the SES. Patients with higher income paid per income group 34 € (95%- KI: 6 €-63 €) more for their denture. People from the middle class had 1.28 (95% CI: 1.02-1.22), and people from the upper class had 1.86 (95%-CI: 1.58-2.18) as much dental coinsurance coverage as people from the lower class. The ability to pay for denture and obtain dental insurance coverage rose with higher SES or HHN. The rise of additional payments for dental services leads to discrepancies in dental health care.

Sex hormones in association with general joint laxity and hypermobility in the temporomandibular joint in adolescents-results of the epidemiologic LIFE child study.

OBJECTIVES: The aim of this cross-sectional study was to investigate whether sex hormones (testosterone, oestradiol, sex-hormone-binding globulin = SHBG) are associated with general joint laxity (GJL) and hypermobility or derangements of the temporomandibular joint (TMJ) in adolescents. METHODS: Within the LIFE Child study, 970 adolescents (10-18 years) were included. GJL was assessed using the Beighton test. Maximum mouth opening (MMO) and clinical clicking sounds as signs of disc displacement (DD) in the TMJ were assessed according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Serum levels of sex hormones were assessed using standardised laboratory analyses. RESULTS: Hypermobile joints were found in 54.9% (N = 532) of the sample; females were more affected than males (61.4% vs. 51.8%, P < 0.001). Using logistic regression analyses, the odds ratio (OR) for having >1 hypermobile joints increased to 1.15 (95% confidence interval [CI]: 1.04-1.27) in males and 1.09 (95% CI: 1.02-1.17) in females per 10 units of the SHBG serum level, compared to those without hypermobile joints-after controlling for the effect of age, adjusted BMI, pubertal development (Tanner scale), testosterone as well as oestradiol levels. Female subjects with >1 hypermobile joints showed a higher OR (1.89; 95% CI: 1.05-3.43) for having clinical clicking sounds in the TMJ and a 3.28 times higher OR (95% CI: 1.44-7.44) for MMO ≥ 55 mm. CONCLUSIONS: We observed age- and gender-independent associations of higher SHBG serum levels with GJL in adolescents. Moreover, hypermobile female adolescents show a more frequent hypermobility of the TMJ and clinical signs of DD.

The oral microbiome-the relevant reservoir for acute pediatric appendicitis?

PURPOSE: The oral microbiome has been related to numerous extra oral diseases. Recent studies detected a high abundance of oral bacteria in inflamed appendices in pediatric patients. To elucidate the role of oral bacteria in acute pediatric appendicitis, we studied the oral and appendiceal microbiome of affected children compared to healthy controls. METHODS: Between January and June 2015, 21 children undergoing appendectomy for acute appendicitis and 28 healthy controls were prospectively enrolled in the study. All individuals underwent thorough dental examination and laboratory for inflammatory parameters. Samples of inflamed appendices and the gingival sulcus were taken for 16S rDNA sequencing. RT-qPCR of Fusobacterium nucleatum, Peptostreptococcus stomatis, and Eikenella corrodens was performed and their viability was tested under acidic conditions to mimic gastric transfer. RESULTS: In phlegmonous appendices, Bacteroidetes and Porphyromonas were discovered as dominant phylum and genus. In sulcus samples, Firmicutes and Streptococcus were detected predominantly. P. stomatis, E. corrodens, and F. nucleatum were identified in each group. Viable amounts of P. stomatis were increased in sulci of children with acute appendicitis compared to sulci of healthy controls. In inflamed appendices, viable amounts of E. corrodens and F. nucleatum were decreased compared to sulci of children with appendicitis. Postprandial viability could be demonstrated for all tested bacteria. CONCLUSION: In children with acute appendicitis, we identified several oral bacterial pathogens. Based on postprandial viability of selected species, a viable migration from the oral cavity through the stomach to the appendix seems possible. Thus, the oral cavity could be a relevant reservoir for acute appendicitis.

Bias in retrospective assessment of perceived dental treatment effects when using the Oral Health Impact Profile.

PURPOSE: Aim of this exploratory study was to investigate whether a retrospective assessment of oral health-related quality of life (OHRQoL) using the Oral Health Impact Profile (OHIP) is susceptible to bias such as implicit theory of change and cognitive dissonance. METHODS: In this prospective clinical study, a sample of 126 adult patients (age 17-83 years, 49% women) requiring prosthodontic treatment was consecutively recruited. The OHRQoL was assessed using the 49-item OHIP at baseline and at follow-up. Additionally, patients were asked at follow-up to retrospectively rate their oral health status at baseline (retrospective pretest or then-test) and the change in oral health status using a global transition question. Furthermore, patients' ratings of overall oral health and general health were used as validity criteria for the OHRQoL assessments. Response shift was calculated as the difference between the initial and retrospective baseline assessments. RESULTS: Baseline and retrospective pretest did not differ substantially in terms of internal consistency and convergent validity. Response shift was more pronounced when patients perceived a large change in OHRQoL during treatment. Retrospective pretests were more highly correlated with the baseline than with the follow-up assessment. CONCLUSION: Findings suggest that retrospective assessments of OHRQoL using the OHIP-49 are susceptible to bias. Cognitive dissonance is more likely to appear as a source of bias than implicit theory of change.

aMMP-8 in correlation to caries and periodontal condition in adolescents-results of the epidemiologic LIFE child study.

OBJECTIVES: The suitability of a chairside aMMP-8 test in determination of periodontal inflammation and caries in adolescents was assessed. Secondly, the influence of orthodontic treatment on aMMP-8 test result was analyzed. MATERIALS AND METHODS: Within the LIFE Child study, 434 adolescents (10 to 18 years) were included. Clinical dental examinations comprised caries experience (DMF/T-Index), signs of periodontal inflammation (probing pocket depth, PPD; community periodontal index of treatment needs; CPITN) at six index teeth and oral hygiene (OH). Information about orthodontic appliances (OA) and socioeconomic status (SES) were obtained by validated questionnaires. Test's sensitivity and specificity to detect periodontal inflammation and carious lesions were evaluated. The influence of OA on the test result was analyzed (multivariate model). RESULTS: No associations between age, gender, SES or OH, and test outcome were found (p > 0.05). Positive test results correlated to periodontal findings (CPITN, mean PPD; p < 0.001). However, for the detection of ≥ 1 site(s) with PPD ≥ 4 mm, the test's sensitivity and specificity were found to be 61 and 69%, respectively. Multivariate analysis revealed a higher probability for a positive test result in cases of fixed OA (odds ratio 5.02, 95% confidence interval 1.90-13.19). The test had no diagnostic value considering carious lesions. CONCLUSIONS: The chairside aMMP-8 test does not reliably identify adolescents with periodontal inflammation. Positive test results were more frequent in case of OA. CLINICAL RELEVANCE: The chairside aMMP-8 test is no appropriate tool to screen children and adolescents neither for periodontal inflammation nor for carious lesions.

The severity and degree of hypomineralisation in teeth and its influence on oral hygiene and caries prevalence in children.

AIM: The purpose of this study was to investigate the relationship between the severity of hypomineralised teeth, plaque accumulation, hypersensitivity, associated caries risk, and oral health-related quality of life limitations of affected children. MATERIALS AND METHODS: A total of 250 children (mean age 9.0 years) presenting with at least one hypomineralised molar or incisor were included in the study. The hypersensitivity of the teeth was evaluated using the Schiff Cold Air Sensitivity Scale and the Wong-Baker Faces Scale. Furthermore, the Decayed, Missing, and Filled Teeth Index was documented, the Quigley Hein Index was obtained, and personal questioning was used to document the patients' limitations with intake of food. These data were analysed using general linear models that control influencing factors such as age and sex. RESULTS: The Quigley Hein Index increased with the severity of the hypomineralised teeth (1.64 in the unaffected, 2.77 in the moderately, and 3.63 in the severely affected teeth). Problems with intake of food were only observed in subjects with severe hypomineralisation. There was no immediate effect on dental caries. CONCLUSION: Increased severity of tooth hypomineralisation leads to increased hypersensitivity, which resulted in inadequate oral hygiene among children and limitations to their daily life.

A Complex of Htm1 and the Oxidoreductase Pdi1 Accelerates Degradation of Misfolded Glycoproteins.

A quality control system in the endoplasmic reticulum (ER) efficiently discriminates polypeptides that are in the process of productive folding from conformers that are trapped in an aberrant state. Only the latter are transported into the cytoplasm and degraded in a process termed ER-associated protein degradation (ERAD). In the ER, an enzymatic cascade generates a specific N-glycan structure of seven mannosyl and two N-acetylglucosamine residues (Man7GlcNAc2) on misfolded glycoproteins to facilitate their disposal. We show that a complex encompassing the yeast lectin-like protein Htm1 and the oxidoreductase Pdi1 converts Man8GlcNAc2 on glycoproteins into the Man7GlcNAc2 signal. In vitro the Htm1-Pdi1 complex processes both unfolded and native proteins albeit with a preference for the former. In vivo, elevated expression of HTM1 causes glycan trimming on misfolded and folded proteins, but only degradation of the non-native species is accelerated. Thus, modification with a Man7GlcNAc2 structure does not inevitably commit a protein for ER-associated protein degradation. The function of Htm1 in ERAD relies on its association with Pdi1, which appears to regulate the access to substrates. Our data support a model in which the balanced activities of Pdi1 and Htm1 are crucial determinants for the efficient removal of misfolded secretory glycoproteins.

The LIFE Child study: a population-based perinatal and pediatric cohort in Germany.

The LIFE Child study is a large population-based longitudinal childhood cohort study conducted in the city of Leipzig, Germany. As a part of LIFE, a research project conducted at the Leipzig Research Center for Civilization Diseases, it aims to monitor healthy child development from birth to adulthood and to understand the development of lifestyle diseases such as obesity. The study consists of three interrelated cohorts; the birth cohort, the health cohort, and the obesity cohort. Depending on age and cohort, the comprehensive study program comprises different medical, psychological, and sociodemographic assessments as well as the collection of biological samples. Optimal data acquisition, process management, and data analysis are guaranteed by a professional team of physicians, certified study assistants, quality managers, scientists and statisticians. Due to the high popularity of the study, more than 3000 children have already participated until the end of 2015, and two-thirds of them participate continuously. The large quantity of acquired data allows LIFE Child to gain profound knowledge on the development of children growing up in the twenty-first century. This article reports the number of available and analyzable data and demonstrates the high relevance and potential of the study.

Usa1 functions as a scaffold of the HRD-ubiquitin ligase.

Protein quality control in the endoplasmic reticulum is of central importance for cellular homeostasis in eukaryotes. Crucial for this process is the HRD-ubiquitin ligase (HMG-CoA reductase degradation), which singles out terminally misfolded proteins and routes them for degradation to cytoplasmic 26S-proteasomes. Certain functions of this enzyme complex are allocated to defined subunits. However, it remains unclear how these components act in a concerted manner. Here, we show that Usa1 functions as a major scaffold protein of the HRD-ligase. For the turnover of soluble substrates, Der1 binding to the C terminus of Usa1 is required. The N terminus of Usa1 associates with Hrd1 and thus bridges Der1 to Hrd1. Strikingly, the Usa1 N terminus also induces oligomerization of the HRD complex, which is an exclusive prerequisite for the degradation of membrane proteins. Our data demonstrate that scaffold proteins are required to adapt ubiquitin ligase activities toward different classes of substrates.

The ubiquitylation machinery of the endoplasmic reticulum.

As proteins travel through the endoplasmic reticulum (ER), a quality-control system retains newly synthesized polypeptides and supports their maturation. Only properly folded proteins are released to their designated destinations. Proteins that cannot mature are left to accumulate, impairing the function of the ER. To maintain homeostasis, the protein-quality-control system singles out aberrant polypeptides and delivers them to the cytosol, where they are destroyed by the proteasome. The importance of this pathway is evident from the growing list of pathologies associated with quality-control defects in the ER.