egr-4, a target of EGFR signaling, is required for the formation of the brian primordial and head regeneration in planarians

During the regeneration of freshwater planarians, polarity and patterning programs play essential roles in determining whether a head or a tail regenerates at anterior or posterior-facing wounds. This decision is made very soon after amputation. The pivotal role of the Wnt/β-catenin and Hh signaling pathways in re-establishing anterior-posterior (AP) polarity has been well documented. However, the mechanisms that control the growth and differentiation of the blastema in accordance with its AP identity are less well understood. Previous studies have described a role of Smed-egfr-3, a planarian epidermal growth factor receptor, in blastema growth and differentiation. Here, we identify Smed-egr-4, a zinc-finger transcription factor belonging to the early growth response gene family, as a putative downstream target of Smed-egfr-3. Smed-egr-4 is mainly expressed in the central nervous system and its silencing inhibits anterior regeneration without affecting the regeneration of posterior regions. Single and combinatorial RNA interference to target different elements of the Wnt/β-catenin pathway, together with expression analysis of brain- and anterior-specific markers, revealed that Smed-egr-4: (1) is expressed in two phases - an early Smed-egfr-3-independent phase and a late Smed-egfr-3-dependent phase; (2) is necessary for the differentiation of the brain primordia in the early stages of regeneration; and (3) that it appears to antagonize the activity of the Wnt/β-catenin pathway to allow head regeneration. These results suggest that a conserved EGFR/egr pathway plays an important role in cell differentiation during planarian regeneration and indicate an association between early brain differentiation and the proper progression of head regeneration.

Use of anisotropic modelling in electrical impedance tomography: description of method and preliminary assessment of utility in imaging brain function in the adult human head.

Electrical Impedance Tomography (EIT) is an imaging method which enables a volume conductivity map of a subject to be produced from multiple impedance measurements. It has the potential to become a portable non-invasive imaging technique of particular use in imaging brain function. Accurate numerical forward models may be used to improve image reconstruction but, until now, have employed an assumption of isotropic tissue conductivity. This may be expected to introduce inaccuracy, as body tissues, especially those such as white matter and the skull in head imaging, are highly anisotropic. The purpose of this study was, for the first time, to develop a method for incorporating anisotropy in a forward numerical model for EIT of the head and assess the resulting improvement in image quality in the case of linear reconstruction of one example of the human head. A realistic Finite Element Model (FEM) of an adult human head with segments for the scalp, skull, CSF, and brain was produced from a structural MRI. Anisotropy of the brain was estimated from a diffusion tensor-MRI of the same subject and anisotropy of the skull was approximated from the structural information. A method for incorporation of anisotropy in the forward model and its use in image reconstruction was produced. The improvement in reconstructed image quality was assessed in computer simulation by producing forward data, and then linear reconstruction using a sensitivity matrix approach. The mean boundary data difference between anisotropic and isotropic forward models for a reference conductivity was 50%. Use of the correct anisotropic FEM in image reconstruction, as opposed to an isotropic one, corrected an error of 24 mm in imaging a 10% conductivity decrease located in the hippocampus, improved localisation for conductivity changes deep in the brain and due to epilepsy by 4-17 mm, and, overall, led to a substantial improvement on image quality. This suggests that incorporation of anisotropy in numerical models used for image reconstruction is likely to improve EIT image quality.

Constant and variable amplitude fatigue strength of high strength steel welds treated with ultrasonic impact treatment

Hitsattujen rakenteiden väsymiskestävyyttä pystytään parantamaan jälkikäsittelymenetelmillä, joistayksi, ultraäänikäsittely muokkaa hitsin geometriaa ja aiheuttaa puristusjäännösjännitystilan. Tässä tutkimuksessa verrataan kokeellisesti kuormaa kantamattoman hitsatun ja ui -käsitellyn rivan väsymislujuutta toisiinsa. Tutkimusohjelmaan kuuluu kahta teräslajia ja sekä vakio - että vaihtuva - amplitudista kuormitusta. Ultraäänikäsittelyllä saavutetaan väsymiskestoiän parantuminen vakio - ja vaihtuva - amplitudisella kuormituksella. Perusaineen lujuudella ei ole merkittää vaikutusta väsymislujuuteen kun liitos on hitsatussa tilassa. Tällöin väsymiskestävyyden määrää hitsin rajaviivan jännityskeskittymä. Ultraäänikäsitellyn hitsatunliitoksen väsymiskestävyys on suurempi korkeamman lujuuden omaavilla teräksillä. Tästä syystä korkealujuuksisten terästen käyttö ultraäänikäsiteltynä väsyttävästi kuormitetuissa kevytrakenteissa on perusteltua.

Critères de qualité en radiothérapie des cancers de la tête et du cou sous l'égide de l'Intergroupe ORL Quality criteria in radiotherapy for head and neck cancers under the aegis of Head and Neck Intergroup.

The aim of radiotherapy is to deliver enough radiation to the tumor in order to achieve maximum tumour control in the irradiated volume with as few serious complications as possible with an irradiation dose as low as possible to normal tissue. The quality of radiotherapy is essential for optimal treatment and quality control is to reduce the bias in clinical trials avoiding possible major deviations. The assurance and quality control programs have been developed in large european (EORTC, GORTEC) and american cooperative groups (RTOG) of radiation oncology since the 1980s. We insist here on the importance of quality assurance in radiotherapy and the current status in this domain and the criteria for quality control especially for current clinical trials within GORTEC are discussed here.

Optimization of energy consumption in wastewater pumping

Pumppauksessa arvioidaan olevan niin teknisesti kuin taloudellisestikin huomattavia mahdollisuuksia säästää energiaa. Maailmanlaajuisesti pumppaus kuluttaa lähes 22 % sähkö-moottorien energiantarpeesta. Tietyillä teollisuudenaloilla jopa yli 50 % moottorien käyttämästä sähköenergiasta voi kulua pumppaukseen. Jäteveden pumppauksessa pumppujen toiminta perustuu tyypillisesti on-off käyntiin, jolloin pumpun ollessa päällä se käy täydellä teholla. Monissa tapauksissa pumput ovat myös ylimitoitettuja. Yhdessä nämä seikat johtavat kasvaneeseen energian kulutukseen. Työn teoriaosassa esitellään perusteet jätevesihuollosta ja jäteveden käsittelystä sekä pumppaussysteemin pääkomponentit: pumppu, putkisto, moottori ja taajuusmuuttaja. Työn empiirisessä osassa esitellään työn aikana kehitetty laskuri, jonka avulla voidaan arvioida energiansäästöpotentiaalia jäteveden pumppaussysteemeissä. Laskurilla on mandollista laskea energiansäästöpotentiaali käytettäessä pumpun tuoton ohjaustapana pyörimisnopeuden säätöä taajuusmuuttajalla on-off säädön sijasta. Laskuri ilmoittaa optimaalisimmanpumpun pyörimisnopeuden sekä ominaisenergiankulutuksen. Perustuen laskuriin, kolme kunnallista jätevedenpumppaamoa tutkittiin. Myös laboratorio-testitsuoritettiin laskurin simuloimiseksi sekä energiansäästöpotentiaalin arvioimiseksi. Tutkimukset osoittavat, että jätevedenpumppauksessa on huomattavia mandollisuuksia säästää energiaa pumpun pyörimisnopeutta pienentämällä. Geodeettisen nostokorkeuden ollessa pieni, voidaan energiaa säästää jopa 50 % ja pitkällä aikavälillä säästö voi olla merkittävä. Tulokset vahvistavat myös tarpeen jätevedenpumppaussysteemien toiminnan optimoimiseksi.

Cigarette, cigar, and pipe smoking and the risk of head and neck cancers: pooled analysis in the International Head and Neck Cancer Epidemiology Consortium.

Cigar and pipe smoking are considered risk factors for head and neck cancers, but the magnitude of effect estimates for these products has been imprecisely estimated. By using pooled data from the International Head and Neck Cancer Epidemiology (INHANCE) Consortium (comprising 13,935 cases and 18,691 controls in 19 studies from 1981 to 2007), we applied hierarchical logistic regression to more precisely estimate odds ratios and 95% confidence intervals for cigarette, cigar, and pipe smoking separately, compared with reference groups of those who had never smoked each single product. Odds ratios for cigar and pipe smoking were stratified by ever cigarette smoking. We also considered effect estimates of smoking a single product exclusively versus never having smoked any product (reference group). Among never cigarette smokers, the odds ratio for ever cigar smoking was 2.54 (95% confidence interval (CI): 1.93, 3.34), and the odds ratio for ever pipe smoking was 2.08 (95% CI: 1.55, 2.81). These odds ratios increased with increasing frequency and duration of smoking (Ptrend ≤ 0.0001). Odds ratios for cigar and pipe smoking were not elevated among ever cigarette smokers. Head and neck cancer risk was elevated for those who reported exclusive cigar smoking (odds ratio = 3.49, 95% CI: 2.58, 4.73) or exclusive pipe smoking (odds ratio = 3.71, 95% CI: 2.59, 5.33). These results suggest that cigar and pipe smoking are independently associated with increased risk of head and neck cancers.

A prospective, randomized, and controlled study of fluid management in children with severe head injury: lactated Ringer's solution versus hypertonic saline.

OBJECTIVES: Resuscitation in severe head injury may be detrimental when given with hypotonic fluids. We evaluated the effects of lactated Ringer's solution (sodium 131 mmol/L, 277 mOsm/L) compared with hypertonic saline (sodium 268 mmol/L, 598 mOsm/L) in severely head-injured children over the first 3 days after injury. DESIGN: An open, randomized, and prospective study. SETTING: A 16-bed pediatric intensive care unit (ICU) (level III) at a university children's hospital. PATIENTS: A total of 35 consecutive children with head injury. INTERVENTIONS: Thirty-two children with Glasgow Coma Scores of <8 were randomly assigned to receive either lactated Ringer's solution (group 1) or hypertonic saline (group 2). Routine care was standardized, and included the following: head positioning at 30 degrees; normothermia (96.8 degrees to 98.6 degrees F [36 degrees to 37 degrees C]); analgesia and sedation with morphine (10 to 30 microg/kg/hr), midazolam (0.2 to 0.3 mg/kg/hr), and phenobarbital; volume-controlled ventilation (PaCO2 of 26.3 to 30 torr [3.5 to 4 kPa]); and optimal oxygenation (PaO2 of 90 to 105 torr [12 to 14 kPa], oxygen saturation of >92%, and hematocrit of >0.30). MEASUREMENTS AND MAIN RESULTS: Mean arterial pressure and intracranial pressure (ICP) were monitored continuously and documented hourly and at every intervention. The means of every 4-hr period were calculated and serum sodium concentrations were measured at the same time. An ICP of 15 mm Hg was treated with a predefined sequence of interventions, and complications were documented. There was no difference with respect to age, male/female ratio, or initial Glasgow Coma Score. In both groups, there was an inverse correlation between serum sodium concentration and ICP (group 1: r = -.13, r2 = .02, p < .03; group 2: r = -.29, r2 = .08, p < .001) that disappeared in group 1 and increased in group 2 (group 1: r = -.08, r2 = .01, NS; group 2: r = -.35, r2 =.12, p < .001). Correlation between serum sodium concentration and cerebral perfusion pressure (CPP) became significant in group 2 after 8 hrs of treatment (r = .2, r2 = .04, p = .002). Over time, ICP and CPP did not significantly differ between the groups. However, to keep ICP at <15 mm Hg, group 2 patients required significantly fewer interventions (p < .02). Group 1 patients received less sodium (8.0 +/- 4.5 vs. 11.5 +/- 5.0 mmol/kg/day, p = .05) and more fluid on day 1 (2850 +/- 1480 vs. 2180 +/- 770 mL/m2, p = .05). They also had a higher frequency of acute respiratory distress syndrome (four vs. 0 patients, p = .1) and more than two complications (six vs. 1 patient, p = .09). Group 2 patients had significantly shorter ICU stay times (11.6 +/- 6.1 vs. 8.0 +/- 2.4 days; p = .04) and shorter mechanical ventilation times (9.5 +/- 6.0 vs. 6.9 +/- 2.2 days; p = .1). The survival rate and duration of hospital stay were similar in both groups. CONCLUSIONS: Treatment of severe head injury with hypertonic saline is superior to that treatment with lactated Ringer's solution. An increase in serum sodium concentrations significantly correlates with lower ICP and higher CPP. Children treated with hypertonic saline require fewer interventions, have fewer complications, and stay a shorter time in the ICU.

Etude de la toxicité hépatique de la cocaïne associée à de l'alcool: Effets de l'éthanol sur le métabolisme de la cocaïne dan les hépatocytes de rat en suspension et dans un modèle enzymatique humain

Le but essentiel de notre travail a été d?étudier la capacité du foie, premier organe de métabolisation des xénobiotiques, à dégrader la cocaïne en présence d?éthanol, à l?aide de deux modèles expérimentaux, à savoir un modèle cellulaire (les hépatocytes de rat en suspension) et un modèle acellulaire (modèle reconstitué in vitro à partir d?enzymes purifiées de foie humain). La première partie a pour objectifs de rechercher les voies de métabolisation de la cocaïne qui sont inhibées et / ou stimulées en présence d?éthanol, sur hépatocytes isolés de rat. Dans ce but, une méthode originale permettant de séparer et de quantifier simultanément la cocaïne, le cocaéthylène et huit de leurs métabolites respectifs a été développée par Chromatographie Phase Gazeuse couplée à la Spectrométrie de Masse (CPG / SM). Nos résultats préliminaires indiquent que l?éthanol aux trois concentrations testées (20, 40 et 80 mM) n?a aucun effet sur la cinétique de métabolisation de la cocaïne. Notre étude confirme que l?addition d?éthanol à des cellules hépatiques de rat en suspension supplémentées en cocaïne résulte en la formation précoce de benzoylecgonine et de cocaéthylène. L?apparition retardée d?ecgonine méthyl ester démontre l?activation d?une deuxième voie de détoxification. La production tardive d?ecgonine indique une dégradation de la benzoylecgonine et de l?ecgonine méthyl ester. De plus, la voie d?oxydation intervenant dans l?induction du stress oxydant en produisant de la norcocaïne est tardivement stimulée. Enfin, notre étude montre une métabolisation complète de la concentration initiale en éthanol par les hépatocytes de rat en suspension. La deuxième partie a pour but de déterminer s?il existe d?autres enzymes que les carboxylesterases formes 1 et 2 humaines ayant une capacité à métaboliser la cocaïne seule ou associée à de l?éthanol. Pour ce faire, une méthode de micropurification par chromatographie liquide (Smart System®) a été mise au point. Dans le cadre de nos dosages in situ de la cocaïne, du cocaéthylène, de la benzoylecgonine, de l?acide benzoïque et de la lidocaïne, une technique par Chromatographie Liquide Haute Performance couplée à une Détection par Barrette de Diode (CLHP / DBD) et une méthode de dosage de l?éthanol par Chromatographie Phase Gazeuse couplée à une Détection par Ionisation de Flamme équipée d?un injecteur à espace de tête (espace de tête CPG / DIF) ont été développées. La procédure de purification nous a permis de suspecter la présence d?autres enzymes que les carboxylesterases formes 1 et 2 de foie humain impliquées dans le métabolisme de la cocaïne et déjà isolées. A partir d?un modèle enzymatique reconstitué in vitro, nos résultats préliminaires indiquent que d?autres esterases que les formes 1 et 2 de foie humain sont impliquées dans l?élimination de la cocaïne, produisant benzoylecgonine et ecgonine méthyl ester. De plus, nous avons montré que les sensibilités de ces enzymes à l?éthanol sont variables.<br/><br/>The main purpose of our work was to study the ability of the liver, as the first organ to metabolise xenobiotic substances, to degrade cocaine in the presence of ethanol. In order to do this, we used two experimental models, namely a cellular model (rat liver cells in suspension) and an a-cellular model (model reconstructed in vitro from purified human liver enzymes). The purpose of the first part of our study was to look for cocaine metabolising processes which were inhibited and / or stimulated by the presence of ethanol, in isolated rat liver cells. With this aim in mind, an original method for simultaneously separating and quantifying cocaine, cocaethylene and eight of their respective metabolites was developed by Vapour Phase Chromatography coupled with Mass Spectrometry (VPC / MS). Our preliminary results point out that ethanol at three tested concentrations (20, 40 et 80 mM) have no effect on the kinetic of metabolisation of cocaine. Our study confirms that the addition of alcohol to rat liver cells in suspension, supplemented with cocaine, results in the premature formation of ecgonine benzoyl ester and cocaethylene. The delayed appearance of ecgonine methyl ester shows that a second detoxification process is activated. The delayed production of ecgonine indicates a degradation of the ecgonine benzoyl ester and the ecgonine methyl ester. Moreover, the oxidising process which occurs during the induction of the oxidising stress, producing norcocaine, is stimulated at a late stage. Finally, our study shows the complete metabolisation of the initial alcohol concentration by the rat liver cells in suspension. The second part consisted in determining if enzymes other than human carboxylesterases 1 and 2, able to metabolise cocaine on its own or with alcohol, existed. To do this, a micropurification method us ing liquid phase chromatography (Smart System®) was developed. A technique based on High Performance Liquid Chromatography coupled with a Diode Array Detection (HPLC / DAD) in the in situ proportioning of cocaine, cocaethylene, ecgonine benzoyl ester, benzoic acid and lidocaine, and a method for proportioning alcohol by quantifying the head space using Vapour Phase Chromatography coupled with a Flame Ionisation Detection (head space VPC / FID) were used. The purification procedure pointed to the presence of enzymes other than the human liver carboxylesterases, forms 1 and 2, involved in the metabolism of cocaine and already isolated. The preliminary results drawn from an enzymatic model reconstructed in vitro indicate that human liver carboxylesterases, other than forms 1 and 2, are involved in the elimination of cocaine, producing ecgonine benzoyl ester and ecgonine methyl ester. Moreover, we have shown that the sensitivity of these enzymes to alcohol is variable.

A comparative performance study of four-pole induction motors and synchronous reluctance motors in variable speed drives

Design aspects of the Transversally Laminated Anisotropic (TLA) Synchronous Reluctance Motor (SynRM) are studied and the machine performance analysis compared to the Induction Motor (IM) is done. The SynRM rotor structure is designed and manufactured for a30 kW, four-pole, three-phase squirrel cage induction motor stator. Both the IMand SynRM were supplied by a sensorless Direct Torque Controlled (DTC) variablespeed drive. Attention is also paid to the estimation of the power range where the SynRM may compete successfully with a same size induction motor. A technicalloss reduction comparison between the IM and SynRM in variable speed drives is done. The Finite Element Method (FEM) is used to analyse the number, location and width of flux barriers used in a multiple segment rotor. It is sought for a high saliency ratio and a high torque of the motor. It is given a comparison between different FEM calculations to analyse SynRM performance. The possibility to take into account the effect of iron losses with FEM is studied. Comparison between the calculated and measured values shows that the design methods are reliable. A new application of the IEEE 112 measurement method is developed and used especially for determination of stray load losses in laboratory measurements. The study shows that, with some special measures, the efficiency of the TLA SynRM is equivalent to that of a high efficiency IM. The power factor of the SynRM at rated load is smaller than that of the IM. However, at lower partial load this difference decreases and this, probably, brings that the SynRM gets a better power factor in comparison with the IM. The big rotor inductance ratio of the SynRM allows a good estimating of the rotor position. This appears to be very advantageous for the designing of the rotor position sensor-less motor drive. In using the FEM designed multi-layer transversally laminated rotor with damper windings it is possible to design a directly network driven motor without degrading the motorefficiency or power factor compared to the performance of the IM.

Risk factors for head and neck cancer in young adults: a pooled analysis in the INHANCE consortium.

BACKGROUND: Increasing incidence of head and neck cancer (HNC) in young adults has been reported. We aimed to compare the role of major risk factors and family history of cancer in HNC in young adults and older patients. METHODS: We pooled data from 25 case-control studies and conducted separate analyses for adults ≤45 years old ('young adults', 2010 cases and 4042 controls) and >45 years old ('older adults', 17 700 cases and 22 704 controls). Using logistic regression with studies treated as random effects, we estimated adjusted odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: The young group of cases had a higher proportion of oral tongue cancer (16.0% in women; 11.0% in men) and unspecified oral cavity / oropharynx cancer (16.2%; 11.1%) and a lower proportion of larynx cancer (12.1%; 16.6%) than older adult cases. The proportions of never smokers or never drinkers among female cases were higher than among male cases in both age groups. Positive associations with HNC and duration or pack-years of smoking and drinking were similar across age groups. However, the attributable fractions (AFs) for smoking and drinking were lower in young when compared with older adults (AFs for smoking in young women, older women, young men and older men, respectively, = 19.9% (95% CI = 9.8%, 27.9%), 48.9% (46.6%, 50.8%), 46.2% (38.5%, 52.5%), 64.3% (62.2%, 66.4%); AFs for drinking = 5.3% (-11.2%, 18.0%), 20.0% (14.5%, 25.0%), 21.5% (5.0%, 34.9%) and 50.4% (46.1%, 54.3%). A family history of early-onset cancer was associated with HNC risk in the young [OR = 2.27 (95% CI = 1.26, 4.10)], but not in the older adults [OR = 1.10 (0.91, 1.31)]. The attributable fraction for family history of early-onset cancer was 23.2% (8.60% to 31.4%) in young compared with 2.20% (-2.41%, 5.80%) in older adults. CONCLUSIONS: Differences in HNC aetiology according to age group may exist. The lower AF of cigarette smoking and alcohol drinking in young adults may be due to the reduced length of exposure due to the lower age. Other characteristics, such as those that are inherited, may play a more important role in HNC in young adults compared with older adults.

Using the optical flow to implement a relative virtual mouse controlled by head movements

The following paper introduces the work conducted to create a relative virtual mouse based on the interpretation of head movements and face gesture through a low cost camera and the optical flow of the images. This virtual device is designed specifically as an alternative non-contact pointer for people with mobility impairments in the upper extremities and reduced head control. The proposed virtual device was compared with a conventional mouse, a touchpad and a digital joystick. Validation results show performances close to a digital joystick but far away from a conventional mouse.

La fonction publique en Suisse : analyse géopolitique d'un fédéralisme à géométrie variable

Bien que présenté comme un modèle de stabilité, le fédéralisme est constamment remis en question. Le but de l'article est de présenter quelques-unes de ses caractéristiques lues à travers les effectifs de la fonction publique en Suisse. Pour ce faire, nous distinguerons quatre types d'employeurs : Confédération, cantons, communes et corporations de droit public, lesquels représentent 10,5 % du total des actifs en Suisse. Nous analyserons la densité administrative, la variation des emplois et le degré de décentralisation selon la culture, le territoire et la religion. Il ressort que la fonction publique intermédiaire, c'est-à-dire les cantons, joue le premier rôle avec ses 140'000 emplois en équivalents plein temps (EPT) sur un total de 328'000, en hausse de 10,3 % par rapport à 2001. Les communes comptent 38 % des agents publics (+3,6 % par rapport à 2001), loin devant la Confédération, 11 % du total (en perte de vitesse : -1,2 %) et les corporations de droit public, 9 % du total (+14,5 %). Le taux d'administration est plus élevé dans la partie francophone que dans la partie germanophone, ainsi que dans les centres économiques et les zones frontières. Les écarts entre les cantons peuvent varier du simple au triple. En fait, deux modèles politico-administratifs transparaissent : le premier « cantonaliste » et davantage étatiste dans la partie latine, l'autre « communaliste » et décentralisé, dominant dans la partie germanophone. Le quotient de décentralisation administrative montre de grandes différences entre l'est et l'ouest, qui s'estompent toutefois avec la modernisation des institutions et le repositionnement de la Suisse face à l'Europe.

Natural vitamin C intake and the risk of head and neck cancer : a pooled analysis in the International Head and Neck Cancer Epidemiology Consortium

Evidence of associations between single nutrients and head and neck cancer (HNC) is still more limited and less consistent than that for fruit and vegetables. However, clarification of the protective mechanisms of fruit and vegetables is important to our understanding of HNC etiology. We investigated the association between vitamin C intake from natural sources and cancer of the oral cavity/pharynx and larynx using individual-level pooled data from ten case-control studies (5,959 cases and 12,248 controls) participating in the International Head and Neck Cancer Epidemiology (INHANCE) consortium. After harmonization of study-specific exposure information via the residual method, adjusted odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were estimated using unconditional multiple logistic regression models on quintile categories of 'non-alcohol energy-adjusted' vitamin C intake. In the presence of heterogeneity of the estimated ORs among studies, we derived those estimates from generalized linear mixed models. Higher intakes of vitamin C were inversely related to oral and pharyngeal (OR = 0.54, 95% CI: 0.45-0.65, for the fifth quintile category versus the first one, p for trend<0.001) and laryngeal cancers (OR = 0.52, 95% CI: 0.40-0.68, p for trend = 0.006), although in the presence of heterogeneity among studies for both sites. Inverse associations were consistently observed for the anatomical subsites of oral and pharyngeal cancer, and across strata of age, sex, education, body mass index, tobacco, and alcohol, for both cancer sites. The inverse association of vitamin C intake from foods with HNC may reflect a protective effect on these cancers; however, we cannot rule out other explanations.