[Combination strategies for checkpoint inhibition: Current practices and perspectives]

T-cell checkpoint blockade therapies have revolutionized treatment protocols and prognosis in patients with cancer. Pointed out by the success of PD-1 (programmed cell death-1) plus CTLA-4 (cytotoxic-T-lymphocyte associated antigen 4) blockade in patients with melanoma, the perspective of new synergistic immunotherapy combinations seems to be an important opportunity to improve outcomes for patients. In this article, we first focus on immunotherapy combinations that have shown their efficiency and that are currently approved in solid tumors. Then, we present a summary of emerging targets with reported pre-clinical efficacy and currently evaluated through ongoing clinical trials and other immunomodulatory molecules in the tumor microenvironment.

Full analysis from AVENANCE: A real-world study of avelumab first-line (1L) maintenance treatment in patients (pts) with advanced urothelial carcinoma (aUC)

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Background: In the phase 3 JAVELIN Bladder 100 trial, avelumab 1L maintenance + best supportive care (BSC) significantly prolonged overall survival (OS) vs BSC alone in pts with aUC that had not progressed with 1L platinum-based chemotherapy (CTx). The JAVELIN Bladder regimen is now standard of care with level 1 evidence in international treatment guidelines. The AVENANCE study (NCT04822350), is investigating the efficacy and safety of avelumab 1L maintenance in a real-world population of pts with aUC in France. Data from the full analysis set are reported for the first time. Methods: In this ongoing, noninterventional, ambispective study, eligible pts have locally advanced or metastatic UC that has not progressed with 1L platinum-based CTx and previous, ongoing, or planned avelumab 1L maintenance treatment. The primary endpoint is OS from start of avelumab; secondary endpoints include progression-free survival (PFS), duration of treatment (DOT), and safety. Results: 591 pts received avelumab. At data cutoff (July 31, 2022), median follow-up was 12.0 mo (95% CI, 10.9-12.9). Median age was 73.1 y (IQR, 67.0-78.1). At start of 1L CTx (excluding pts with missing data), disease stage was metastatic in 524 pts (90.5%; visceral metastases in 426 [81.5%]) and locally advanced in 54 (9.3%). ECOG PS was 0-1 in 407 pts (85.3%) and 2-3 in 69 (14.5%). Tumor histology was pure UC in 528 pts (91.8%) and UC with variant or pure variant in 47 (8.2%). 1L CTx was gemcitabine + carboplatin (GemCarbo), gemcitabine + cisplatin (GemCis), dose-dense methotrexate + vinblastine + adriamycin + cisplatin (DD-MVAC), and other in 353 (61.0%), 170 (29.4%), 28 (4.8%), and 28 (4.8%) pts, respectively. Median number of cycles was 5 (range, 1-10). Median DOT with avelumab was 5.8 mo (95% CI, 5.2-7.0); 241 pts (40.8%) remained on treatment at data cutoff. The most common reasons for treatment discontinuation were disease progression (74.1% [n=258]), death (11.5% [n=40]), and adverse events ([AEs] 10.3% [n=36]). Median OS from start of avelumab was 18.4 mo (95% CI, 15.4-not estimable [NE]), the 12-month OS rate was 64.8% (95% CI, 60.0%-69.1%), and median PFS was 5.7 mo (95% CI, 5.3-7.0). In pts who had received GemCarbo, GemCis, or DD-MVAC, median OS (95% CI) was 16.2 mo (13.4-NE), not reached (NR; 18.1-NE), and NR (15.2-NE), respectively. Subgroups analyses will be presented. 218 pts received subsequent 2L, including CTx, antibody-drug conjugates, immunotherapy, and other in 186 (85.3%), 22 (10.1%), 6 (2.8%), and 4 (1.8%) pts, respectively. Any-grade treatment-related AEs (TRAEs) occurred in 217 pts (36.7%), including serious TRAEs in 29 (4.9%). Conclusions: Real-world data for avelumab 1L maintenance in pts with aUC from AVENANCE support the findings of JAVELIN Bladder 100 and confirm the clinical activity and acceptable safety profile of avelumab in a heterogeneous population. Clinical trial information: NCT04822350 .

Survival Rate of CAD-CAM Endocrowns Performed by Undergraduate Students

OBJECTIVES

This study aimed to evaluate the success of computer-aided design-computer-aided manufacturing (CAD-CAM) endocrown restorations of endodontically treated teeth (ETT) performed by supervised undergraduate students. The study also intended to identify possible factors that may lead to failures.

METHODS AND MATERIALS

This observational open cohort study was based on clinical data from endocrown restorations performed by residents and undergraduate students in their 4th, 5th, and 6th year from July 2011 to May 2018. The presence of a tooth with an endocrown on the arch was the main criteria used to calculate the survival rate of restored teeth. The quality of the remaining endocrowns was evaluated referring to the FDI criteria. The cases of failure were categorized into either favorable or unfavorable.

RESULTS

A total of 343 ETT were restored with endocrowns in 315 patients. Among them, 199 patients encompassing 225 endocrowns were followed during a 56 ± 26 month period. The survival rate of restored teeth was found to be 81.8%, the estimated Kaplan-Meier survival rate being 71.8% at 9 years. Among the 41 failed cases, 32 were favorable (debonding and/or ceramic fractures) and 9 were unfavorable.

CONCLUSION

Endocrown restorations of posterior ETT using CAD-CAM technologies could be carried out by undergraduates with a low risk of failure. Teacher supervision could be reinforced, covering all steps of each endocrown procedure in order to avoid failures due to insufficient thickness or loss of retention.

Palladin isoforms 3 and 4 regulate cancer-associated fibroblast pro-tumor functions in pancreatic ductal adenocarcinoma

Pancreatic Ductal Adenocarcinoma (PDAC) has a five-year survival under 10%. Treatment is compromised due to a fibrotic-like stromal remodeling process, known as desmoplasia, which limits therapeutic perfusion, supports tumor progression, and establishes an immunosuppressive microenvironment. These processes are driven by cancer-associated fibroblasts (CAFs), functionally activated through transforming growth factor beta1 (TGFβ1). CAFs produce a topographically aligned extracellular matrix (ECM) that correlates with reduced overall survival. Paradoxically, ablation of CAF populations results in a more aggressive disease, suggesting CAFs can also restrain PDAC progression. Thus, unraveling the mechanism(s) underlying CAF functions could lead to therapies that reinstate the tumor-suppressive features of the pancreatic stroma. CAF activation involves the f-actin organizing protein palladin. CAFs express two palladin isoforms (iso3 and iso4) which are up-regulated in response to TGFβ1. However, the roles of iso3 and iso4 in CAF functions remain elusive. Using a CAF-derived ECM model, we uncovered that iso3/iso4 are required to sustain TGFβ1-dependent CAF activation, secrete immunosuppressive cytokines, and produce a pro-tumoral ECM. Findings demonstrate a novel role for CAF palladin and suggest that iso3/iso4 regulate both redundant and specific tumor-supportive desmoplastic functions. This study highlights the therapeutic potential of targeting CAFs to restore fibroblastic anti-tumor activity in the pancreatic microenvironment.

Impact of Androgen Deprivation Therapy Associated to Conformal Radiotherapy in the Treatment of D'Amico Intermediate-/High-Risk Prostate Cancer in Older Patients

PURPOSE/OBJECTIVE

The association of 3D Conformal External Beam Radiotherapy (3D-CEBRT) with adjuvant Androgen Deprivation Therapy (ADT) proved to treat patients with intermediate- and high-risk localized prostate cancer (IR and HR). However, older patients were underrepresented in literature. We aimed to report the oncological results and morbidity 3D-CEBRT +ADT in ≥80 years patients.

MATERIAL AND METHODS

From June 1998 to July 2017, 101 patients ≥80 years were included in a tertiary center. The median age was 82 years. ADT was initiated 3 months prior 3D-CEBRT in all patients, with a total duration of 6 months for IR prostate cancer (group A; n = 41) and 15 months for HR prostate cancer (group B; n = 60). Endpoints included overall survival (OS), metastasis-free survival (DMFS), biochemical recurrence-free survival (BRFS) and toxicity.

RESULTS

Five years-OS was 95% and 86.7% in groups A and B, respectively. Cardiovascular events occurred in 22.8% of ≥80 years patients with no impact on OS. In the multivariate analysis, age <82 years, Karnofsky index and normalization of testosterone levels were significantly associated with better OS.

CONCLUSION

Age ≥80 years should not be a limitation for the treatment of IR and HR prostate cancer patients with 3D-CEBRT and ADT, but cardiovascular monitoring and prevention are mandatory.

Targeting BRCA Deficiency in Breast Cancer: What are the Clinical Evidences and the Next Perspectives?

Breast cancers (BC) associated with germline mutations of BRCA1/2 represent 3–5% of cases. BRCA1/2-associated BC have biological features leading to genomic instability and potential sensitivity to DNA damaging agents, including poly(ADP-ribose) polymerase (PARP) and platinum agents. In this review, we will summarize clinical trials of chemotherapy and PARP inhibitors (PARPi), alone or in combination, at the early or late stage of BRCA1/2-associated BC. We will also present the mechanisms of resistance to PARPi as well as the new therapeutic strategies of association with PARPi. Finally, we will discuss under which conditions the use of DNA damaging agents can be extended to the BRCA1/2-wild type population, the BRCAness concept.

Shoulder Arthroplasty Imaging: What's New

Background

Shoulder arthroplasty, in its different forms (hemiarthroplasty, total shoulder arthroplasty and reverse total shoulder arthroplasty) has transformed the clinical outcomes of shoulder disorders. Improvement of general clinical outcome is the result of stronger adequacy of the treatment to the diagnosis, enhanced surgical techniques, specific implanted materials, and more accurate follow up. Imaging is an important tool in each step of these processes.

Method

This article is a review article declining recent imaging processes for shoulder arthroplasty.

Results

Shoulder imaging is important for shoulder arthroplasty pre-operative planning but also for post-operative monitoring of the prosthesis and this article has a focus on the validity of plain radiographs for detecting radiolucent line and on new Computed Tomography scan method established to eliminate the prosthesis metallic artefacts that obscure the component fixation visualisation.

Conclusion

Number of shoulder arthroplasties implanted have grown up rapidly for the past decade, leading to an increase in the number of complications. In parallel, new imaging system have been established to monitor these complications, especially component loosening.

Impact of early childhood caries and its treatment under general anesthesia on orofacial function and quality of life : A prospective comparative study

BACKGROUND

Early Childhood Caries (ECC) has become a major public health concern worldwide, mostly affecting children from disadvantaged families in increasingly severe forms. This condition has been frequently reported to alter children's nutrition, growth and general development. It negatively impacts their quality of life, through painful episodes and severe eating difficulties. While this period is crucial for oral praxes development, the impact of dental state on oro-facial functions is poorly documented. This study evaluated the impact of ECC and its treatment under general anesthesia on oro-facial functions and quality of life in pre-school children.

MATERIAL AND METHODS

The dysfunction and quality of life scores from 25 children with ECC were evaluated before treatment (T0), one month (T1) and three months after treatment (T2), using the Nordic Orofacial Test-Screening (NOT-S) and the Early Childhood Oral Health Impact Scale (ECOHIS), respectively, in comparison with 16 caries-free children. The number and extent of inter-arch dental contacts were also observed.

RESULTS

The pre-operative higher NOT-S score observed in children with ECC decreased to reach the control level at T2. The mastication item was the most affected in the ECC group throughout the study. Their mean ECOHIS score also significantly decreased post-operatively and differences remaining between both groups were no longer clinically relevant. In addition, in children with ECC, values of functional inter-arch surfaces tended to increase over the follow-up period.

CONCLUSIONS

Oro-facial functions and quality of life, altered by ECC, could be restored through a conservative treatment approach. Relations between dental state, orofacial functions and particularly chewing, and nutrition should be investigated further.

Torque resistance of impression copings after direct implant impression: An in vitro evaluation of impression materials with and without adhesive

STATEMENT OF PROBLEM

No data are available on the ability of an impression coping to resist the manual placement of an abutment replica (implant analog) during prosthodontic laboratory procedures after a direct (pick-up) impression.

PURPOSE

The purpose of this in vitro study was to evaluate the torque resistance of impression copings after a direct impression, that is, the amount of rotational torque sufficient to induce irreversible displacement of impression copings in the impression material bulk once the impression has been made.

MATERIAL AND METHODS

A reference model with 5 abutment replicas was constructed. Five impression copings were screwed onto the abutment replicas, and standardized impressions were made. A controlled twisting force was applied to each impression coping. A torque tester recorded the torque variation. Three elastomeric impression materials were tested. ANOVA and the Tukey test (α=.05) were performed using an average of 30 measurements per impression material, with and without adhesive.

RESULTS

ANOVA and the Tukey test results showed that the adhesive, cohesive, and mechanical bonds between the impression coping and the impression material depended greatly on the type of material and that the average rupture threshold of these bonds was statistically significantly different in pairwise comparisons (P<.05). The curve analysis showed that when the impression materials are used with adhesives, the deformation of the interface is irreversible beyond 5 Ncm of torque.

CONCLUSIONS

The polyether impression material is the direct impression material that showed the highest breakdown threshold for adhesive bonding when used without an adhesive. The use of an adhesive on impression copings leads to irreversible deformation of the interface at torque stresses well below the adhesive bond threshold of the same materials used without an adhesive.

[Evaluation of the professional dentists' ability to determine the tooth shade guide: a pilot study]

BACKGROUND

During its clinical practice, the dentist is often faced with issues concerning the determination of teeth shade. This step is considered sensitive by numerous clinicians and dental laboratories. The objective of this study was to test the ability of professional dentists to visually determine the teeth color.

MATERIAL AND METHODS

Eleven dentists classified 35 unmarked samples according to their hue, chroma and value from 2 standardized tooth shade guides Ivoclar-Vivadent (Chromascop) et Vita (3D Master). The ratio between the number of matching samples and the total amount of samples from each group was calculated and converted to a score between 0 and 10.

RESULTS

Better scores were obtained for value and chroma with the 3D Master shade guide than with the Chromascop shade guide (p < 0.001). The opposite result was obtained for the hue (p < 0.05). Globally, better results were obtained for the value and chroma, the hue being the most difficult item to evaluate. A satisfying "color perception" was observed in 69% of the cases.

CONCLUSION

The results of this study argue in favor of a specific training for tooth shade determination in Odontology.

Evaluation of Cerec endocrowns: a preliminary cohort study

This study aimed to evaluate clinical qualities and evolution on ceramic endocrowns produced with the Cerec 3D (Sirona). Endocrowns were produced in a hospital environment and evaluated according to the FDI criteria on the day of placement and 6 months afterwards. Each item was graded from 1 (good) to 5 (bad). A global score, as well as a score for aesthetics, functioning and biological integration was assessed for each evaluation. During the 6-month evaluation period, the scores were always related to good clinical quality, except for single crown restoration. The scores did not change between the two periods of evaluation.

Chewing deficiencies in adults with multiple untreated carious lesions

Persons who have multiple untreated carious lesions are at high risk of chewing difficulties and consequently an unhealthy diet, but few data are available on the impact of untreated caries on mastication in adults. This study in adults with multiple untreated caries lesions aimed to evaluate chewing deficiencies using physiological and psychosocial indicators. Forty-five patients, mean (±SD) decayed teeth 11.5 (±5.2), and 20 fully dentate caries-free subjects were observed during mastication of raw carrot and two jelly model foods differing in hardness. Criteria for chewing evaluation were carrot bolus granulometry, food refusals, chewing activity (chewing time, number of chewing cycles, chewing frequency) and oral health-related quality of life (GOHAI). Dental status was characterized by caries experience (DMFT) and posterior functional pairs of teeth. Adults with multiple untreated caries lesions suffered from chewing deficiencies, demonstrated by a decrease in food comminution related to the number of posterior functional teeth, food selection and functional alterations in oral health-related quality of life. The ability to adapt chewing activity to food hardness was preserved in this group. Further studies should be conducted to determine whether chewing function could be improved after dental treatment.

A description of oral health in three French jails

Prisoners display many features suggestive of a higher risk of poorer oral health than the general population. They have many risk factors: disadvantaged social background, consumption of psychoactive substances and a high proportion of persons with mental illness. The oral health of prisoners is handled by different care providers such as hospital doctors together with some students, interns, and some dedicated dental practitioners. There are few data describing the outcomes of this activity.

OBJECTIVE

The objective of this descriptive study was to determine the oral health of prisoners in the current care system as observed in three French jails.

PARTICIPANTS

84 male prisoners were allocated to two subgroups according to the duration of incarceration: a short-term group (< or = 2 years; 31 subjects, mean age: 31 (sd 13) years) and a long-term group (> 2 years; 53 subjects, mean age: 43 (sd 11) yearss). One investigator performed a semi-guided interview and a dental examination.

MAIN OUTCOME MEASURES

The DMFT index, the Global Oral Health Assessment Index, the number of dental functional units and some specific indicators on mastication were collected.

RESULTS

Duration of incarceration explained more variability than age for numbers of missing teeth (26%; p < 0.001) and functional units (24%; p < 0.001). Long-term prisoners had greater chewing difficulties than short-term prisoners.

CONCLUSIONS

This study suggested that, in the French jails studied, a stable level of oral infection including untreated caries was obtained at the cost of a degraded masticatory function.

Educational needs in the field of detection of domestic violence and neglect: the opinion of a population of French dentists

OBJECTIVES

The attitude of French dentists concerning domestic abuse has hardly ever been documented upon so far. The purpose of this study is to investigate the attitudes, knowledge and practices of a population of French general dental practitioners towards the prevention and detection of signs of neglect and abuse in order to determine the educational needs both during undergraduate curriculum and continuing education sessions.

METHODS

A total of 418 general dental practitioners all practising in the French area of Puy de Dôme were invited to participate in the study. The survey was conducted with questionnaires including multiple-choice or open questions and VAS scales.

RESULTS

The response rate was 54% (228/418). Only 5.7% of the practitioners systematically look for signs of neglect or abuse when treating their patients. 36% declare having already come across one or several cases of abuse and 48% having suspected at least one. The patients concerned were mainly women (54%). Only 28% would adopt an attitude in compliance with the French legislation if confronted with a case of abuse or domestic violence. 75.9% of the practitioners would like more training and assistance in the detection and care of abused patients and particularly as regards signs of abuse and the legal framework.

CONCLUSIONS

More information and training concerning abuse and domestic violence is required in the French undergraduate dental curriculum in order to help practitioners deal with such patients.

Changes in mastication after an immediate loading implantation with complete fixed rehabilitation

OBJECTIVE

This study aimed to measure modifications of mastication after immediate loading full-arch prosthesis (ILFAP) rehabilitation.

MATERIALS AND METHOD

Fourteen patients were observed before and 6 months after ILFAP rehabilitation when masticating two natural, standardized foods (peanut and carrot) and three model foods with increasing hardness. The granulometry of the expectorated boluses from carrot and peanuts was characterized by median particle size (D50), determined at the natural point of swallowing. Chewing time (CT), number of chewing cycles (CC), and chewing frequency (CF) were video recorded. A self-assessment questionnaire for oral health-related quality of life [Geriatric Oral Health Assessment Index (GOHAI)] was also used.

RESULTS

After ILFAP rehabilitation, the mean D50 values for carrot and peanuts were smaller [Repeated Model Procedures (RMP), F = 41, p < 0.001]. Mean CT and CC values recorded with the three model foods decreased, while CF increased regardless of the model food hardness (RMP, F = 14, F = 10, and F = 11, respectively, p < 0.001). The GOHAI score increased from 43 ± 9 to 56 ± 3 (t test, p < 0.001).

CONCLUSION

ILFAP rehabilitation improves the ability to reduce the bolus particle size and the ability to discriminate between different food hardnesses in the 6 months post-surgery period.

CLINICAL RELEVANCE

This study encourages the clinical development of immediate loading implantation with a fixed full-arch prosthesis protocol.

Involvement of cytosolic ascorbate peroxidase and Cu/Zn-superoxide dismutase for improved tolerance against drought stress

In order to understand the role of cytosolic antioxidant enzymes in drought stress protection, transgenic tobacco (Nicotiana tabacum cv. Xanthi) plants overexpressing cytosolic Cu/Zn-superoxide dismutase (cytsod) (EC 1.15.1.1) or ascorbate peroxidase (cytapx) (EC 1.11.1.1) alone, or in combination, were produced and tested for tolerance against mild water stress. The results showed that the simultaneous overexpression of Cu/Znsod and apx or at least apx in the cytosol of transgenic tobacco plants alleviates, to some extent, the damage produced by water stress conditions. This was correlated with higher water use efficiency and better photosynthetic rates. In general, oxidative stress parameters, such as lipid peroxidation, electrolyte leakage, and H(2)O(2) levels, were higher in non-transformed plants than in transgenic lines, suggesting that, at the least, overexpression of cytapx protects tobacco membranes from water stress. In these conditions, the activity of other antioxidant enzymes was induced in transgenic lines at the subcellular level. Moreover, an increase in the activity of some antioxidant enzymes was also observed in the chloroplast of transgenic plants overexpressing cytsod and/or cytapx. These results suggest the positive influence of cytosolic antioxidant metabolism on the chloroplast and underline the complexity of the regulation network of plant antioxidant defences during drought stress.

Expression of S100A8 in leukemic cells predicts poor survival in de novo AML patients

Cytogenetic stratification remains insufficient for almost half of the acute myeloblastic leukemia (AML) cases, with AML patients requiring subsequent molecular investigation. In our study, we used mass spectrometry (MS)-based proteomic approaches to characterize de novo AML. Fifty-four samples (mononuclear cells from bone marrow or peripheral blood mononuclear cells collected and frozen before treatment) from two independent cohorts of newly diagnosed AML patients were analyzed. We showed that the protein signature of leukemic cells defined two clusters that displayed significant variation for overall and disease-free survival (P=0.001 and 0.0004, respectively). This proteomic classification refines the cytogenetic classes. AML patients with intermediate and unfavorable cytogenetic classifications could be subdivided according to their protein profiles into subgroups with significantly different survival rates. Among the proteins expressed by leukemic cells, we isolated a 10,800-Da marker that retained the highest discriminative value between living and deceased patients. The 10,800-Da marker was identified by MS peptide sequencing as S100A8 (also designated MRP8 or calgranulin A). Western blot analysis confirmed its expression mainly in AML patients with the worst prognosis, arguing for a selective deregulation associated with poor prognosis. These results suggest that the expression of S100A8 in leukemic cells is a predictor of low survival.

The masticatory normative indicator

There is no established quantitative, objective method to differentiate individuals with good masticatory function from those lacking this attribute. The aim of this study was to specify a normal range of median particle size values for masticated raw carrots collected just before being swallowed. The masticatory normative indicator (MNI) value thus obtained was based on seven studies carried out by different investigators using different methods for measuring particle size in carrot boluses. A simple mathematical transformation of variables and the choice of an interval of +/-1.96 times the standard deviation gave 4.0 mm as the upper limit of normal median particle size for carrots in a population of young persons with good oral health. This value identifies boluses that may be considered as resulting from impaired mastication, as illustrated in healthy individuals with experimentally hampered mastication, denture wearers, and individuals presenting with obesity or Down syndrome.

Reactivity of transparent exopolymeric particles: a key parameter of trace metal cycling in the lagoon of Nouméa, New Caledonia

Seawater samples were collected in the lagoon of Nouméa (New Caledonia) along two transects from coastal bays to the oligotrophic barrier reef. Dissolved (<0.2 microm) and sub-micrometer (0.2-0.8 microm) concentrations of chromium, nickel and zinc were measured. Concentrations in the 0.2-0.8 microm size range were correlated with transparent exopolymeric particles (TEP) turnover rates, suggesting that a TEP pool rapidly cycling in the system is more reactive toward metals. The role of TEP reactivity in the transfer efficiency of metals from dissolved to particulate phases was estimated through variations of the metal partitioning coefficient K between sub-micrometer TEP and solution, as a function of the water mass residence time. The log K (6.0-8.0) increased from high to low residence time, suggesting that TEP reactivity increases when water masses renew rapidly. This suggests that hydrodynamics control TEP reactivity toward metals. The characteristics (adsorption vs. complexation) of TEP-metal association are discussed.

Is the tongue position influenced by the palatal vault dimensions?

The influence of the palatal vault dimensions on tongue position is here studied through evaluation of the in-mouth air cavity (IMAC) volume when the mandible is in maximal intercuspal position. A sample of 35 women (mean age 21.2 +/- 1.0) and 15 men (mean age 22.1 +/- 0.9) was selected. The sagittal cross-section area of the IMAC, which is modulated by the tongue position, was measured on lateral cephalograms. Dental casts were used to measure the palatal vault volume, which was defined by the occlusal plane, the hard palate and the posterior face of the second molars. Palatal vault volume allowed deduction of the IMAC volume through a rule of three procedure relating volume to area ratios. No IMAC could be calculated from cephalograms of 10 subjects who had the tongue stuck to the palate. For the 40 other subjects, the IMAC volume was 8.9 +/- 4.8 mL. It was 2 mL larger in men (n = 14) than in women (n = 26) and was the largest in skeletal Class III and the smallest in skeletal Class II (P > 0.05). IMAC volume was strongly correlated with palatal vault height but neither with palatal width nor length. It was thus assumed that the height of the palatal vault could influence the most observed position of the tongue but this does not exclude a possible growth influence of the tongue on its surrounding skeletal structures.

Clermont-Ferrand dental school curriculum: an appraisal by last-year students and graduates

OBJECTIVE

Last-year students and young graduates of the Clermont-Ferrand dental school (France) assessed their professional skills in order to shed light on those which are perfectly mastered and those which are not, with the aim of improving the undergraduate training given by the school.

METHODS

A questionnaire was handed out to students in their last two years and to young graduates (n = 170). They were asked to appraise their self-assessed level concerning 52 skills using a 0-10 visual analogue scale. The respondents also had to highlight the five skills which, according to them, needed to be improved during the programme.

RESULTS

Thirteen skills obtained a score lower than 5/10 showing a need of more thorough training, notably in the fields of implantology, paradontal surgery, temporomandibular joint disorders and dental practice financial management. Among these, five skills were found that demand in depth acquisition according to respondents. However, these five skills are not necessarily the ones which obtained the lowest scores.

CONCLUSIONS

Our school needs to improve the quality of its training, notably by reorganising some of its courses and by intensifying student' training in outreach programmes, particularly in private practice, where skills like the financial management of a dental practice could be more easily acquired than in a hospital environment.

The role of the Birt-Hogg-Dubé protein in mTOR activation and renal tumorigenesis

Birt-Hogg-Dubé (BHD) syndrome is a tumor-suppressor gene disorder characterized by skin tumors, cystic lung disease and renal cell carcinoma. Very little is known about the molecular pathogenesis of BHD. Clinical similarities between BHD and tuberous sclerosis complex (TSC) suggest that the BHD and TSC proteins may function within a common pathway. The TSC proteins inhibit the activity of the mammalian target of rapamycin complex 1 (TORC1), and in Schizosaccharomyces pombe, Bhd and Tsc1/Tsc2 have opposing roles in the regulation of amino-acid homeostasis. We report here that in mammalian cells, downregulation of BHD reduces the phosphorylation of ribosomal protein S6, an indicator of TORC1 activity. To determine whether folliculin, the product of the BHD gene, regulates mammalian target of rapamycin activity in vivo, we generated a mouse with targeted inactivation of the Bhd gene. The mice developed spontaneous oncocytic cysts and tumors composed of cells that resemble the renal cell carcinomas in BHD patients. The cysts and tumors had low levels of phospho-S6. Taken together, these data indicate that folliculin regulates the activity of TORC1, and suggest a new paradigm in which both inappropriately high and inappropriately low levels of TORC1 activity can be associated with renal tumorigenesis.

Dental difficulty for adult patients undergoing different dental procedures according to level of dental anxiety

This study aimed to determine the level of dental anxiety before different dental care procedures. A group of 116 adults presenting for the first time at a French dental hospital were included in the study. These patients completed a French-language version of Corah's Dental Anxiety Scale 1 and used a visual analogue scale to score their perception of the level of difficulty generated by 13 different dental treatments. The acts perceived as the most difficult to face were root canal and restorative treatment without local anaesthesia (LA), followed by oral surgery. There was a positive correlation between DAS score and level of difficulty experienced during dental treatment. Healthy subjects declared difficulty in coping with dental care. Dental procedures may be a factor of co morbidity in terms of the psychological status of dental patients. A classification of dental procedures is given according to the level of difficulty generated.

[Obesity and oral health: risk factors of obese patients in dental practice]

For 20 years, on a worldwide scale, the prevalence of obesity has always progressed as well in child as in adult. Obesity is frequently associated with other pathologies: cardiovascular, oncologic, systemic (diabetes) or oral. In this situation, the follow-up of obesity and its co morbidity needs a multidisciplinary approach. Obesity and oral health pathologies have risk factors in common, particularly dietary one. Indeed, it is established that food affects oral health. In the same way, an unbalanced diet raises the risk of overweight or obesity. Thereby, owing to these inter relations, the World Health Organization advocates to insert oral health in the Program for Global Health. First, this study presents the factors of risks that obesity and oral health diseases have in common. After, the risks and the specificity of the care of obese patients are outlined. Consecutively, a program of prevention and education of oral health is proposed.

Validation of video versus electromyography for chewing evaluation of the elderly wearing a complete denture

Chewing efficiency may affect nutritional status in the elderly. Many elderly patients are complete denture wearers, and often present cognitive problems. Those two factors make evaluation of mastication difficult with experimental methods. Analysis of video recording may be a simple way to routinely assess chewing parameters. This study aimed at validating several parameters of video evaluation versus electromyography (EMG), which is considered the 'gold standard'. The design was a prospective randomized study, carried out at the Faculty of Dentistry, University of Auvergne, Clermont-Ferrand, France. Twelve complete denture wearers chewed four model foods differing in hardness. Sessions were videotaped and EMG recordings were registered. Mastication time, number of masticatory cycles and cleaning time were recorded simultaneously by video and EMG. Two investigators independently analyzed the videos twice, in random order. Evaluation of criterion validity: a positive video/EMG correlation was found for the parameters 'chewing time' (0.89, Pearson) and 'number of masticatory cycles' (0.94, Spearman), whereas no statistical difference was found between these two EMG and video variables (t-test). Inter and intra-rater reliability gave a positive intraclass coefficient (ICC) for duration of mastication (0.86-0.98), number of masticatory cycles (0.90-0.97) and cleaning time (0.90-0.98). Discriminatory ability was studied using anova (P = 0.01): variation was significant in masticatory duration (F = 10), number of masticatory cycles (F = 10) and cleaning time (F = 4). Video may be a useful assessment tool in prosthetic rehabilitation and can be applied to help choose the type of food (solid, semi-liquid or liquid) to administer to dependent persons, particularly those suffering from dementia.

Mastication of model products in complete denture wearers

OBJECTIVE

The aim of this study was to define the characteristics of muscular activity in complete denture wearers and in dentate subjects during mastication of model foods differing in hardness but similar in terms of rheologically properties.

MATERIAL AND METHODS

The foodstuffs used in this study were laboratory-developed gumdrops demonstrating viscoelastic properties. The test foods cover a range of four hardness levels. The group of complete denture wearers included 15 subjects, while the control group included 9 subjects with normal dentition. Electromyograph (EMG) recordings were taken from the masseter and temporal muscles during mastication of the test foods. The results were evaluated by one-way and two-way ANOVA followed by means comparisons using a Student-Newman-Keuls post hoc test (alpha=0.05).

RESULTS

Preparing the same food bolus for swallowing required a greater number of masticatory cycles and a longer duration of mastication for complete denture wearers than for dentate subjects. In addition, complete denture wearers failed to increase EMG activity per cycle in response to hardness of the food.

CONCLUSION

Denture wearers experienced difficulties during mastication, as indicated by a decreased masticatory rate and the observed failure to increase EMG activity per cycle in response to increased food hardness. The increases in number of cycle and masticatory duration appear to be a response to this impaired masticatory function.

Age and gender-related differences in premolar and molar functional areas

The aim of the present study was to underline the difference in premolar-molar functional areas according to both age and gender in a human adult population. Premolar and molar series were marked manually on opposed casts with articulating paper and functional areas were evaluated by quantification of these markings. It was noticed that on average larger functional areas were displayed by the older group (19 individuals, mean age 71.2 years, minimum 68 years, maximum 73 years) in comparison with the younger one (24 individuals, mean age 27.4 years, minimum 22 years; maximum 33 years). It was also observed that the average total functional area (4 hemiarches) was larger in the male subgroup (n: 23; mean age 45; young adults, 14; old adults, 9) compared with the female one (n: 20; mean age 49; young adults, 10; old adults, 10). Nevertheless, this gender difference in premolar-molar functional areas was related to the individual occlusal areas. As a matter of fact, when the individual occlusal area was taken into account for each series in the form of a ratio (functional area/occlusal area), the values obtained were not different between both gender subgroups studied. When comparing premolar and molar functional ratios (functional area/occlusal area) between age groups, it appears that the values obtained were slightly higher for the premolar series (ratios for young and older adults, respectively: Premolar series: 23.6+/-7.5%, 30+/-6.5%; Molar series: 23.1+/-6.8%, 27.3+/-6.7%). This difference was interpreted in relation to the reference (occlusal area) chosen.

Histone modifications silence the GATA transcription factor genes in ovarian cancer

Altered expression of GATA factors was found and proposed as the underlying mechanism for dedifferentiation in ovarian carcinogenesis. In particular, GATA6 is lost or excluded from the nucleus in 85% of ovarian tumors and GATA4 expression is absent in majority of ovarian cancer cell lines. Here, we evaluated their DNA and histone epigenetic modifications in five ovarian epithelial and carcinoma cell lines (human 'immortalized' ovarian surface epithelium (HIO)-117, HIO-114, A2780, SKOV3 and ES2). GATA4 and GATA6 gene silencing was found to correlate with hypoacetylation of histones H3 and H4 and loss of histone H3/lysine K4 tri-methylation at their promoters in all lines. Conversely, histone H3/lysine K9 di-methylation and HP1gamma association were not observed, excluding reorganization of GATA genes into heterochromatic structures. The histone deacetylase inhibitor trichostatin A, but not the DNA methylation inhibitor 5'-aza-2'-deoxycytidine, re-established the expression of GATA4 and/or GATA6 in A2780 and HIO-114 cells, correlating with increased histone H3 and H4 acetylation, histone H3 lysine K4 methylation and DNase I sensitivity at the promoters. Therefore, altered histone modification of the promoter loci is one mechanism responsible for the silencing of GATA transcription factors and the subsequent loss of a target gene, the tumor suppressor Disabled-2, in ovarian carcinogenesis.

Transcriptional repression by the retinoblastoma protein through the recruitment of a histone methyltransferase

The E2F transcription factor controls the cell cycle-dependent expression of many S-phase-specific genes. Transcriptional repression of these genes in G(0) and at the beginning of G(1) by the retinoblasma protein Rb is crucial for the proper control of cell proliferation. Rb has been proposed to function, at least in part, through the recruitment of histone deacetylases. However, recent results indicate that other chromatin-modifying enzymes are likely to be involved. Here, we show that Rb also interacts with a histone methyltransferase, which specifically methylates K9 of histone H3. The results of coimmunoprecipitation experiments of endogenous or transfected proteins indicate that this histone methyltransferase is the recently described heterochromatin-associated protein Suv39H1. Interestingly, phosphorylation of Rb in vitro as well as in vivo abolished the Rb-Suv39H1 interaction. We also found that Suv39H1 and Rb cooperate to repress E2F activity and that Suv39H1 could be recruited to E2F1 through its interaction with Rb. Taken together, these data indicate that Suv39H1 is involved in transcriptional repression by Rb and suggest an unexpected link between E2F regulation and heterochromatin.

The histone deacetylase HDAC3 targets RbAp48 to the retinoblastoma protein

The product of the retinoblastoma susceptibility gene, the Rb protein, functions partly through transcriptional repression of E2F-regulated genes. Repression by Rb is mediated, at least in part, by a histone deacetylase complex, whose enzymatic activity relies on HDAC1, HDAC2 or HDAC3. Recently, we have shown that the Rb-associated histone deacetylase complex contains RbAp48 protein, which interacts with HDAC1 and HDAC2. RbAp48 could favour the deacetylation of histones since it binds directly to histone H4. In agreement with that, we show that transcriptional repression of E2F activity requires the presence of RbAp48. HDAC3 was thought not to interact with RbAp48. However, we found that it shared with HDAC1 the ability to favour the recruitment of RbAp48 to Rb. This latter effect was unlikely to be due to activation of Rb function, since HDAC3 did not increase Rb-E2F1 interaction. Rather, we found, surprisingly, that HDAC3 could physically interact with RbAp48 both in vitro and in living cells. Taken together, our data suggest a model in which Rb mediates the recruitment to E2F-regulating promoters of a repressive complex containing either HDAC1, HDAC2 or HDAC3 and the histone-binding protein RbAp48.

Selecting a longitudinal pathway: Robo receptors specify the lateral position of axons in the Drosophila CNS

On each side of the midline of the Drosophila CNS, axons are organized into a series of parallel pathways. Here we show that the midline repellent Slit, previously identified as a short-range signal that regulates midline crossing, also functions at long range to pattern these longitudinal pathways. In this long-range function, Slit signals through the receptors Robo2 and Robo3. Axons expressing neither, one, or both of these receptors project in one of three discrete lateral zones, each successively further from the midline. Loss of robo2 or robo3 function repositions axons closer to the midline, while gain of robo2 or robo3 function shifts axons further from the midline. Local cues further refine the lateral position. Together, these long- and short-range guidance cues allow growth cones to select with precision a specific longitudinal pathway.

Crossing the midline: roles and regulation of Robo receptors

In the Drosophila CNS, the midline repellent Slit acts at short range through its receptor Robo to control midline crossing. Longitudinal axons express high levels of Robo and avoid the midline; commissural axons that cross the midline express only low levels of Robo. Robo levels are in turn regulated by Comm. Here, we show that the Slit receptors Robo2 and Robo3 ensure the fidelity of this crossing decision: rare crossing errors occur in both robo2 and robo3 single mutants. In addition, low levels of either Robo or Robo2 are required to drive commissural axons through the midline: only in robo,robo2 double mutants do axons linger at the midline as they do in slit mutants. Robo2 and Robo3 levels are also tightly regulated, most likely by a mechanism similar to but distinct from the regulation of Robo by Comm.

Gelonin is an unusual DNA glycosylase that removes adenine from single-stranded DNA, normal base pairs and mismatches

We reported that plant ribosome inactivating proteins (RIP) have a unique DNA glycosylase activity that removes adenine from single-stranded DNA (Nicolas, E., Beggs, J. M., Haltiwanger, B. M., and Taraschi, T. F. (1998) J. Biol. Chem. 273, 17216-17220). In this investigation, we further characterized the interaction of the RIP gelonin with single-stranded oligonucleotides and investigated its activity on double-stranded oligonucleotides. At physiological pH, zinc and beta-mercaptoethanol stimulated the adenine DNA glycosylase activity of gelonin. Under these conditions, gelonin catalytically removed adenine from single-stranded DNA and, albeit to a lesser extent, from normal base pairs and mismatches in duplex DNA. Also unprecedented was the finding that activity on single-stranded and double-stranded oligonucleotides containing multiple adenines generated unstable products with several abasic sites, producing strand breakage and duplex melting, respectively. The results from competition experiments suggested similar interactions between gelonin's DNA-binding domain and oligonucleotides with and without adenine. A re-examination of the classification of gelonin as a DNA glycosylase/AP lyase using the borohydride trapping assay revealed that gelonin was similar to the DNA glycosylase MutY: both enzymes are monofunctional glycosylases, which are trappable to their DNA substrates. The k(cat) for the removal of adenine from single-stranded DNA was close to the values observed with multisubstrate DNA glycosylases, suggesting that the activity of RIPs on DNA may be physiologically relevant.

RbAp48 belongs to the histone deacetylase complex that associates with the retinoblastoma protein

The retinoblastoma susceptibility gene product, the Rb protein, is a key regulator of mammalian cell proliferation. One of the major targets of Rb is the S phase inducing E2F transcription factor. Once bound to E2F, Rb represses the expression of E2F-regulated genes. Transcriptional repression by Rb is believed to be crucial for the proper control of cell growth. Recently, we and others showed that Rb represses transcription through the recruitment of a histone deacetylase. Interestingly, we show here that the Rb-associated histone deacetylase complex could deacetylate polynucleosomal substrates, indicating that other proteins could be present within this complex. The Rb-associated protein RbAp48 belongs to many histone deacetylase complexes. We show here that the histone deacetylase HDAC1 is able to mediate the formation of a ternary complex containing Rb and RbAp48. Moreover, less deacetylase activity was found associated with Rb in cell extracts depleted for RbAp48 containing complexes, demonstrating that Rb, histone deacetylase, and RbAp48 are physically associated in live cells. Taken together, these data indicate that RbAp48 is a component of the histone deacetylase complex recruited by Rb. Finally, we found that E2F1 and RbAp48 are physically associated in the presence of Rb and HDAC1, suggesting that RbAp48 could be involved in transcriptional repression of E2F-responsive genes.

DNA base excision repair in human malaria parasites is predominantly by a long-patch pathway

Mammalian cells repair apurinic/apyrimidinic (AP) sites in DNA by two distinct pathways: a polymerase beta (pol beta)-dependent, short- (one nucleotide) patch base excision repair (BER) pathway, which is the major route, and a PCNA-dependent, long- (several nucleotide) patch BER pathway. The ability of a cell-free lysate prepared from asexual Plasmodium falciparum malaria parasites to remove uracil and repair AP sites in a variety of DNA substrates was investigated. We found that the lysate contained uracil DNA glycosylase, AP endonuclease, DNA polymerase, flap endonuclease, and DNA ligase activities. This cell-free lysate effectively repaired a regular or synthetic AP site on a covalently closed circular (ccc) duplex plasmid molecule or a long (382 bp), linear duplex DNA fragment, or a regular or reduced AP site in short (28 bp), duplex oligonucleotides. Repair of the AP sites in the various DNA substrates involved a long-patch BER pathway. This biology is different from mammalian cells, yeast, Xenopus, and Escherichia coli, which predominantly repair AP sites by a one-nucleotide patch BER pathway. The apparent absence of a short-patch BER pathway in P. falciparum may provide opportunities to develop antimalarial chemotherapeutic strategies for selectively damaging the parasites in vivo and will allow the characterization of the long-patch BER pathway without having to knock-out or inactivate a short-patch BER pathway, which is necessary in mammalian cells.

A new class of DNA glycosylase/apurinic/apyrimidinic lyases that act on specific adenines in single-stranded DNA

Although the biological function of DNA glycosylases is to protect the genome by removal of potentially cytotoxic or mutagenic bases, this investigation describes the existence of natural DNA glycosylases with activity on undamaged, nonmispaired bases. Gelonin, pokeweed antiviral protein, and ricin, previously described as ribosome-inactivating proteins, are shown to damage single-stranded DNA by removal of a protein-specific set of adenines and cleavage at the resulting abasic sites. Using an oligonucleotide as the substrate reveals that the reaction proceeds via the enzyme-DNA imino intermediate characteristic of DNA glycosylase/AP lyases. The adenine glycosylase activity on single-stranded DNA reported here challenges the concept that a normal base has to be in a mismatch to be specifically removed. By contrast to other glycosylases, these enzymes are expected to damage DNA rather than participate in repair processes. The significance of this DNase activity to the biological function of these plant proteins and to their toxicity to animal cells remains to be determined.