A single-cell atlas deconstructs heterogeneity across multiple models in murine traumatic brain injury and identifies novel cell-specific targets.

Traumatic brain injury (TBI) heterogeneity remains a critical barrier to translating therapies. Identifying final common pathways/molecular signatures that integrate this heterogeneity informs biomarker and therapeutic-target development. We present the first large-scale murine single-cell atlas of the transcriptomic response to TBI (334,376 cells) across clinically relevant models, sex, brain region, and time as a foundational step in molecularly deconstructing TBI heterogeneity. Results were unique to cell populations, injury models, sex, brain regions, and time, highlighting the importance of cell-level resolution. We identify cell-specific targets and previously unrecognized roles for microglial and ependymal subtypes. Ependymal-4 was a hub of neuroinflammatory signaling. A distinct microglial lineage shared features with disease-associated microglia at 24 h, with persistent gene-expression changes in microglia-4 even 6 months after contusional TBI, contrasting all other cell types that mostly returned to naive levels. Regional and sexual dimorphism were noted. CEREBRI, our searchable atlas (https://shiny.crc.pitt.edu/cerebri/), identifies previously unrecognized cell subtypes/molecular targets and is a leverageable platform for future efforts in TBI and other diseases with overlapping pathophysiology.

Prospective Collection of PROMIS Physical Function Measure Demonstrates Significant Improvement After Bariatric Surgery.

BACKGROUND: We evaluated quality of life among bariatric surgery patients using patient-reported outcomes (PROs). We hypothesized that physical function would improve after bariatric surgery. METHODS: We prospectively collected PROs beginning in December 2015. We used the validated Patient-Reported Outcomes Measurement Information System (PROMIS) instruments because of their broad applicability and ability to use computer-adapted technology to survey. Measures are repeated at clinic visits, both pre- and postoperatively. Data were reviewed through February 2018. Data were analyzed comparing pre- and postop physical function PRO (PF PRO) by procedure: laparoscopic Roux-en-Y gastric bypass (LRYGB) or sleeve gastrectomy (LSG). Additional variables were included in an adjusted linear mixed-effects regression model in order to isolate the effect of surgery on PF PRO over time. RESULTS: This cohort included 279 bariatric surgery patients. The mean follow-up time was 1.5 years after surgery. The procedure groups were similar in terms of age and race but differed by gender and preoperative BMI. The PF-PRO measure showed significant improvement following surgery for both procedures. CONCLUSION: Patient-reported physical function improved significantly after bariatric surgery. There was no significant difference between procedures.

Dual Ring Wound Protector Reduces Circular Stapler Related Surgical Site Infections in Patients Undergoing Laparoscopic Roux-En-Y Gastric Bypass.

BACKGROUND: While there are various techniques to create the gastrojejunostomy during a laparoscopic Roux-en-Y gastric bypass (LRYGB), many surgeons prefer using a circular stapler. One drawback of this method, however, is the higher incidence of surgical site infections (SSIs). To investigate the effect of a dual ring wound protector on SSIs during LRYGB. METHODS: In April 2016, our bariatric surgical group implemented an intervention whereby a dual ring wound protector in conjunction with a conical EEA stapler introducer was used when creating the gastrojejunostomy. SSIs from pre- and post-intervention were compared using Fisher's exact test. Only LRYGBs performed with a circular stapler were included in our analysis. Student's t test and χ2 were used to compare pre- and post-intervention groups with respect to demographics and co-morbidities. RESULTS: Between April 2015 and January 31st, 2017, our surgeons performed 158 LRYGBs using a circular stapler for the gastrojejunostomy. There were 84 patients (53%) in the pre-intervention group and 74 (47%) in the post-intervention group. The pre- and post-intervention groups were not statistically different. The SSI rate for the pre-intervention group was 9.5% while the SSI rate was 1.35% in the post-intervention group (p = 0.0371). The use of a dual ring wound protector for LRYGBs with circular stapled gastrojejunostomy was associated with an 86% relative risk reduction in SSIs. CONCLUSION: Using a dual ring wound protector in conjunction with a conical EEA introducer for LRYGBs with circular stapled gastrojejunostomy significantly decreased SSIs.

Calcium regulation of endothelin-1 synthesis in rat inner medullary collecting duct.

Collecting duct-derived endothelin-1 (ET-1) reduces blood pressure and inhibits Na and water reabsorption. Collecting duct ET-1 production is increased by volume expansion; however, the mechanism by which this occurs is unknown. We hypothesized that intracellular calcium, which is likely to be increased by volume expansion, regulates collecting duct ET-1 synthesis. Rat inner medullary collecting ducts (IMCD) were studied in primary culture. ET-1 release was decreased by 50-70% after chelation of intracellular calcium (BAPTA) or inhibition of CaM (W7) or CaMK (KN-93). These agents reduced ET-1 mRNA to a similar degree. CaM inhibition did not affect ET-1 mRNA stability. Transfection of IMCD with rat ET-1 promoter-luciferase constructs revealed maximal activity within 1.7 kb 5' to the transcription start site; 5, 20, 35, and 90% of this activity were in the 0.08-, 0.37-, 1.0-, and 3.0-kb promoter regions, respectively. W7 markedly inhibited activity of the 3.0-kb but not 0.37- or 1.0-kb promoter regions. In contrast, W7 did not affect ET-1 release by rat aortic endothelial cells. Furthermore, transfected endothelial cells had maximal activity in the 0.37-kb region (as compared with the 1.7- and 3.0-kb regions), whereas W-7 had no effect on the activity of any of these promoter regions. In summary, IMCD ET-1 synthesis is regulated by calcium/CaM/CaMK-dependent pathways. The calcium/CaM-sensitive pathway is active in IMCD, but not endothelial cells. This suggests that IMCD-specific enhancer elements exist within the ET-1 promoter that confer unique calcium responsiveness.