Locomotor play behavior evolves by random genetic drift but not as a correlated response to selective breeding for high voluntary wheel-running behavior.

Locomotor play is vigorous and seemingly purposeless behavior, commonly observed in young mammals. It can be costly in terms of energy expenditure, increased injury risk, and predator exposure. The main hypothesized benefit of locomotor play is enhancement of neuromuscular development, with effects persisting into adulthood. We hypothesized that levels of locomotor play would have evolved as a correlated response to artificial selection for increased voluntary exercise behavior. We studied mice from 4 replicate lines bred for voluntary wheel running (High Runner or HR) at 6-8 weeks of age and four non-selected Control (C) lines. Mice were weaned at 21 days of age and play behavior was observed for generations 20 (22-24 days old), 68 (22-23 days old), and 93 (15 days old). We quantified locomotor play as (1) rapid, horizontally directed jerk-run sequences and (2) vertical "bouncing." We used focal sampling to continuously record behavior in cages containing 4-6 individuals during the first 2-3 h of the dark cycle. Observations were significantly repeatable between observers and days. A two-way, mixed-model simultaneously tested effects of linetype (HR vs. C), sex, and their interaction. Contrary to our hypothesis, HR and C lines did not differ in any generation, nor did we find sex differences. However, differences among the replicate HR lines and among the replicate C lines were detected, and may be attributed to the effects of random genetic drift (and possibly founder effects). Thus, play behavior did evolve in this selection experiment, but not as a correlated response to selection for voluntary exercise.

Severe acute liver injury associated with Yersinia enterocolitica.

Yersinia enterocolitica is a Gram-negative bacterium that causes foodborne illnesses, typically characterised by acute febrile gastroenteritis and is associated with a variety of manifestations. Isolated febrile illness without gastrointestinal symptoms is rare. We report a case of Y. enterocolitica infection with severe anicteric hepatitis. A 33-year-old Chinese man with no significant medical history presented on multiple occasions to the emergency department with recurrent high-grade fever and chills, but without gastrointestinal symptoms. Hepatic panel showed rising transaminases that peaked at Aspartate Aminotransferase (AST) of 991 U/L and Alanine Aminotransferase (ALT) of 1664 U/L. CT of the abdomen revealed terminal ileitis and mesenteric adenitis. As part of workup, we found positive serology for Y. enterocolitica Ultimately, he improved with supportive care. This case highlights the importance of thorough workup of terminal ileitis and 'Crohn's mimics' which ultimately revealed a unifying diagnosis; and an important addition to the workup for undifferentiated severe isolated hepatocellular liver injury.

Use of complementary therapies for chronic pain management in patients with reported Ehlers-Danlos syndrome or hypermobility spectrum disorders.

Ehlers-Danlos Syndromes (EDS) and related Hypermobility Spectrum Disorders (HSD) are debilitating connective tissue disorders that feature a prominent pain component for which there are limited therapeutic options for pain management. Consequently, many patients try various non-prescribed treatments, including complementary and alternative therapies that have not been well studied in the EDS/HSD patient population. We surveyed over 500 individuals through the EDS Society who reported having been diagnosed with EDS or HSD to ascertain what complementary and alternative therapies were used and their reported effectiveness in alleviating pain and improving quality of life. Specifically, we focused on the use of traditional Chinese therapies, herbal medications, and marijuana. The most commonly reported therapies, used by 70-92% of participants, were non-steroidal anti-inflammatory drugs, acetaminophen, opioids, and physical therapy. Therapies rated by participants as most efficacious were opioids, physical therapy, and marijuana with 10-24% of those using these therapies rating them as extremely helpful. Patient-initiated complementary therapy use in EDS/HSD patients is widespread at 56%. Complementary therapies were largely utilized by EDS/HSD patients with higher reported pain levels. Providers caring for EDS/HSD patients should be aware of these data showing broad usage of predominantly non-prescribed therapies and be prepared to consider such usage in working collaboratively with these patients to develop comprehensive treatment plans to manage their chronic pain complications.