Fasting increases microbiome-based colonization resistance and reduces host inflammatory responses during an enteric bacterial infection.

Reducing food intake is a common host response to infection, yet it remains unclear whether fasting is detrimental or beneficial to an infected host. Despite the gastrointestinal tract being the primary site of nutrient uptake and a common route for infection, studies have yet to examine how fasting alters the host's response to an enteric infection. To test this, mice were fasted before and during oral infection with the invasive bacterium Salmonella enterica serovar Typhimurium. Fasting dramatically interrupted infection and subsequent gastroenteritis by suppressing Salmonella's SPI-1 virulence program, preventing invasion of the gut epithelium. Virulence suppression depended on the gut microbiota, as Salmonella's invasion of the epithelium proceeded in fasting gnotobiotic mice. Despite Salmonella's restored virulence within the intestines of gnotobiotic mice, fasting downregulated pro-inflammatory signaling, greatly reducing intestinal pathology. Our study highlights how food intake controls the complex relationship between host, pathogen and gut microbiota during an enteric infection.

Evaluation of cerebral oxygen perfusion during shoulder arthroplasty performed in the semi-beach chair position.

BACKGROUND: The beach chair position is commonly used when performing shoulder arthroplasty. However, this position has been associated with hypotension, potentially leading to cerebral hypoperfusion, which may cause neurologic injury. In addition, shoulder arthroplasty cases are associated with longer operative times, posing a potentially greater risk of cerebral hypoperfusion. We aim to evaluate the risk of cerebral desaturation events (CDEs) during the course of total shoulder arthroplasty. METHODS: Twenty-six patients undergoing shoulder arthroplasties were monitored for changes in cerebral perfusion. Seven specific time-points during the procedure were labeled for comparison of events: baseline, beach chair, incision, humeral broaching, glenoid reaming, glenoid component implantation, and humeral component implantation. Cerebral oxygen perfusion was measured using near-infrared spectroscopy. A CDE was described as a decrease of oxygen saturation greater than 20%. RESULTS: Nineteeen of 25 subjects experienced a CDE. 42% of these patients experienced CDEs during semi-beach chair positioning. Patients experienced the largest oxygen saturation drop during semi-beach chair positioning. Transition from baseline to semi-beach chair was the only event to have a statistically significant decrease in cerebral perfusion (8%, P < .05). There was a statistically significant percentage change in mean oxygen saturation in the semi-beach chair interval (10%, P < .01) and the semi-beach chair to incision interval (7%, P < .01). CONCLUSIONS: Most patients experienced an intraoperative CDE, with greatest incidence during semi-beach chair positioning. The largest decline in cerebral oxygen saturation occurred during semi-beach chair positioning. Implant implantation was not associated with decrease in cerebral oximetry.

The relationship between the incidence of adhesive capsulitis and hemoglobin A1c.

BACKGROUND: Previous studies have shown no correlation between adhesive capsulitis and hemoglobin A1c (HbA1c). However, HbA1c is only a measure of short-term blood sugar control. We created a previously nonvalidated variable, cumulative HbA1c, that uses HbA1c values over time to estimate the total disease burden a single individual experiences over a period. In this study, we aimed to evaluate whether a correlation exists between cumulative HbA1c levels in diabetic patients and the prevalence of frozen shoulder. We hypothesized that poor long-term glucose control would be correlated with increased incidence of adhesive capsulitis. METHODS: A retrospective analysis at a single institution was performed. Data from all patients from a single institution with any HbA1c values were collected. A total of 24,417 patients met the inclusion criteria. A variable was created establishing the cumulative magnitude of abnormal HbA1c values over time, termed "cumulative HbA1c." Logistic regression analysis was performed to determine whether long-term glucose control was predictive of the development of adhesive capsulitis. RESULTS: Cumulative HbA1c was positively associated with adhesive capsulitis (7.6 × 10-5) (ie, odds ratio of 1.000076). The effect size of cumulative HbA1c on adhesive capsulitis was significant; for each unit of time that the HbA1c level was greater than 7, there was a 2.77% increase in the risk of adhesive capsulitis. DISCUSSION: Cumulative HbA1c was associated with an increased incidence of adhesive capsulitis. This finding suggests that the effects of diabetes that predispose patients to the development of adhesive capsulitis are dose dependent. Patients with worse blood sugar control over a longer period are at an increased risk of the development of adhesive capsulitis.