Applauding with Closed Hands: Neural Signature of Action-Sentence Compatibility Effects

BACKGROUND: Behavioral studies have provided evidence for an action-sentence compatibility effect (ACE) that suggests a coupling of motor mechanisms and action-sentence comprehension. When both processes are concurrent, the action sentence primes the actual movement, and simultaneously, the action affects comprehension. The aim of the present study was to investigate brain markers of bidirectional impact of language comprehension and motor processes. METHODOLOGY/PRINCIPAL FINDINGS: Participants listened to sentences describing an action that involved an open hand, a closed hand, or no manual action. Each participant was asked to press a button to indicate his/her understanding of the sentence. Each participant was assigned a hand-shape, either closed or open, which had to be used to activate the button. There were two groups (depending on the assigned hand-shape) and three categories (compatible, incompatible and neutral) defined according to the compatibility between the response and the sentence. ACEs were found in both groups. Brain markers of semantic processing exhibited an N400-like component around the Cz electrode position. This component distinguishes between compatible and incompatible, with a greater negative deflection for incompatible. Motor response elicited a motor potential (MP) and a re-afferent potential (RAP), which are both enhanced in the compatible condition. CONCLUSIONS/SIGNIFICANCE: The present findings provide the first ACE cortical measurements of semantic processing and the motor response. N400-like effects suggest that incompatibility with motor processes interferes in sentence comprehension in a semantic fashion. Modulation of motor potentials (MP and RAP) revealed a multimodal semantic facilitation of the motor response. Both results provide neural evidence of an action-sentence bidirectional relationship. Our results suggest that ACE is not an epiphenomenal post-sentence comprehension process. In contrast, motor-language integration occurring during the verb onset supports a genuine and ongoing brain motor-language interaction

Effect of warming anesthetic on pain perception during dental injection: a split-mouth randomized clinical trial

Pedro Christian Aravena,1,2 Camila Barrientos,1 Catalina Troncoso,1 Cesar Coronado,3 Pamela Sotelo-Hitschfeld4 1Department of Dentistry, Universidad Austral de Chile, Valdivia, Chile; 2Department of Dental Implant Surgery, São Leopoldo Mandic School and Dental Institute, Campinas, SP, Brazil; 3Faculty of Health Science, School of Medicine, Universidad Autónoma de Chile, Santiago, Chile; 4Department of Center for Interdisciplinary Studies on Nervous System (CISNe), Universidad Austral de Chile, Valdivia, Chile Background: The purpose of this study is to determine the effectiveness of warming anesthesia on the control of the pain produced during the administration of dental anesthesia injection and to analyze the role of Transient Receptor Potential Vanilloid-1 nociceptor channels in this effect.Patients and methods: A double-blind, split-mouth randomized clinical trial was designed. Seventy-two volunteer students (22.1±2.45 years old; 51 men) from the School of Dentistry at the Universidad Austral de Chile (Valdivia, Chile) participated. They were each administered 0.9 mL of lidocaine HCl 2% with epinephrine 1:100,000 (Alphacaine®) using two injections in the buccal vestibule at the level of the upper lateral incisor teeth. Anesthesia was administered in a hemiarch at 42°C (107.6°F) and after 1 week, anesthesia was administered by randomized sequence on the contralateral side at room temperature (21°C–69.8°F) at a standardized speed. The intensity of pain perceived during the injection was compared using a 100 mm visual analog scale (VAS; Wilcoxon test p<0.05).Results: The use of anesthesia at room temperature produced an average VAS for pain of 35.3±16.71 mm and anesthesia at 42°C produced VAS for pain of 15±14.67 mm (p<0.001).Conclusion: The use of anesthesia at 42°C significantly reduced the pain during the injection of anesthesia compared to its use at room temperature during maxillary injections. The physiological mechanism of the temperature on pain reduction could be due to a synergic action on the permeabilization of the Transient Receptor Potential Vanilloid-1 channels, allowing the passage of anesthetic inside the nociceptors. Keywords: pain, dental anesthesia, maxillary, lidocaine, trigeminal nerve, clinical trial, TRP channe

Chilean patients’ perception of oral health-related quality of life after third molar surgery

Pedro Christian Aravena,1,2 Felipe Delgado,1 Hugo Olave,1 Carolina Ulloa-Marin,3 Francisco Perez-Rojas4 1School of Dentistry, Faculty of Medicine, 2Institute of Anatomy, Histology and Pathology, Faculty of Medicine, Universidad Austral de Chile, Valdivia, 3Department of Dentistry Based-Evidence, School of Dentistry, Universidad de Chile, Santiago, 4School of Medicine, Universidad Autónoma de Chile, Talca, Chile Objective: To describe the perception of the quality of life in oral health based on the Health-Related Quality of Life instrument in its Spanish version (HRQOL-sp) in Chilean patients with third molar extraction surgery. Patients and methods: A cross-sectional study. The HRQOL-sp was administered to dental patients at the Public Hospital in Rio Bueno in southern Chile treated for unilateral third molar extraction between March and June 2014. The instrument was applied by phone survey on the first, third, fifth, and seventh days after surgery. For the ordinal scale, the response was considered interference in the quality of life when patients selected the options “quite a bit of trouble” or “lots of trouble” for oral function and general activity; and selected complications-related signs and symptoms, a pain level score with a Verbal Rating Scale (range 0 to 7), and worst pain perceived. The patient’s sociodemographic data, type of surgery, and the quality of life level were analyzed according to the domains of the HRQOL-sp instrument. Results: A total of 106 patients were selected (age: 20.4±7.39 years; 71.7% women) and a total of 127 extracted third molars. On the first day of follow-up, most patients reported interference in their quality of life. The main problems were difficulty opening the mouth (50.94%) and swelling (83.02%). The worst symptom perceived was “bad breath” (>31%) and the worst pain felt was a mean of 4.31±1.62 on the Verbal Rating Scale. All items gradually reduced until the seventh day. Conclusion: The HRQOL-sp revealed substantial interference in the quality of life on the first postoperative day. It is suggested that the risk factors associated with quality of life be analyzed and the instrument in Spanish be validated. Keywords: quality of life, complications, extraction, third molar, dentistry, oral surger

Dissolved Organic Carbon in Multilayered Aquifers of Pondicherry Region (India): Spatial and Temporal Variability and Relationships to Major Ion Chemistry

Carbon, which is an essential element found in rocks and minerals, is used by biologically diverse life forms as a source of energy. Natural organic carbon is mainly derived from decomposing vegetation and other organic matter in the soil zone. Dissolved organic carbon (DOC) is an important component in biogeochemical cycling of elements characterized by high susceptibility to leaching. The significance of DOC was studied in layered coastal aquifers of the Pondicherry region during four different seasons. Pondicherry region has varied geological setup ranging from Cretaceous to Recent formations. A total of 324 groundwater samples were collected from various aquifers, namely Alluvium, Tertiary, Cretaceous, and Mixed formations, during different seasons of pre-monsoon, southwest monsoon, northeast monsoon, and post-monsoon. The samples were analyzed for major ions and DOC. The range of DOC in the study area is 0–10 mg/l. Very high DOC concentrations were measured in most of the samples from Alluvium and Upper Cuddalore Formation and in few samples from the Lower Cuddalore Formation. The relationships of DOC with other ions in this study indicate that the hydrochemistry of groundwater was controlled by both aerobic and anaerobic environments in the different formations of the study area