Increased Purinergic Signaling in Human Dental Pulps With Inflammatory Pain is Sex-Dependent.

An enhanced understanding of neurotransmitter systems contributing to pain transmission aids in drug development, while the identification of biological variables like age and sex helps in the development of personalized pain management and effective clinical trial design. This study identified enhanced expression of purinergic signaling components specifically in painful inflammation, with levels increased more in women as compared to men. Inflammatory dental pain is common and potentially debilitating; as inflammation of the dental pulp can occur with or without pain, it provides a powerful model to examine distinct pain pathways in humans. In control tissues, P2X3 and P2X2 receptors colocalized with PGP9.5-positive nerves. Expression of the ecto-nucleotidase NTPDase1 (CD39) increased with exposure to extracellular adenosine triphosphate (ATP), implying CD39 acted as a marker for sustained elevation of extracellular ATP. Both immunohistochemistry and immunoblots showed P2X2, P2X3, and CD39 increased in symptomatic pulpitis, suggesting receptors and the ATP agonist were elevated in patients with increased pain. The increased expression of P2X3 and CD39 was more frequently observed in women than men. In summary, this study identifies CD39 as a marker for chronic elevation of extracellular ATP in fixed human tissue. It supports a role for increased purinergic signaling in humans with inflammatory dental pain and suggests the contribution of purines shows sexual dimorphism. This highlights the potential for P2X antagonists to treat pain in humans and stresses the need to consider sex in clinical trials that target pain and purinergic pathways. PERSPECTIVE: This article demonstrates an elevation of ATP-marker CD39 and of ATP receptors P2X2 and P2X3 with inflammatory pain and suggests the rise is greater in women. This highlights the potential for P2X antagonists to treat pain and stresses the consideration of sexual dimorphism in studies of purines and pain.

Stress Level of Dental and Medical Students: Comparison of Effects of a Subject-Based Curriculum versus a Case-Based Integrated Curriculum.

The aim of this study was to investigate the stress level of medical and dental students at Kuwait University after a case-based integrated curriculum replaced the former subject-based curriculum. A modified version of the Dental Environment Stress questionnaire was used to measure possible stressors for both medical and dental students. The investigators administered the questionnaire for the first time in 2008, when Kuwait University medical and dental schools followed a subject-based curriculum (group A). The same questionnaire was administered for a second time in 2014, when both medical and dental schools had adopted a case-based integrated curriculum (group B). A total of 345 fifth- and sixth-year medical and dental students responded to the questionnaire (group A=187, group B=158), with an overall 83% response rate. The results showed that, for both the dental and medical students, changing to a case-based integrated curriculum raised the stress level for most of the stressors evaluated. "Inconsistency of feedback on work between different instructors," "difficulties in communicating with teaching staff," "amount of assigned class work," and "examinations and grades" were some of the statistically significant stressors for group B students. Female students reported higher levels of stress than male students in both groups. These results suggest that introducing stress management education into the case-based integrated dental and medical curricula could enhance students' psychological well-being.