Uncontrolled noncompressible hemorrhage is a major cause of mortality following traumatic injuries in civilian and military populations. An injectable hemostat for point-of-care treatment of noncompressible hemorrhage represents an urgent medical need. Here, we describe an injectable hemostatic agent via polymer peptide interfusion (HAPPI), a hyaluronic acid conjugate with a collagen-binding peptide and a von Willebrand factor–binding peptide. HAPPI exhibited selective binding to activated platelets and promoted their accumulation at the wound site in vitro. In vivo studies in mouse tail vein laceration model demonstrated a reduction of >97% in both bleeding time and blood loss. A 284% improvement in the survival time was observed in the rat inferior vena cava traumatic model. Lyophilized HAPPI could be stably stored at room temperature for several months and reconstituted during therapeutic intervention. HAPPI provides a potentially clinically translatable intravenous hemostat.

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Intravenous nanoparticle hemostats offer a potentially attractive approach to promote hemostasis, in particular for inaccessible wounds such as noncompressible torso hemorrhage (NCTH). In this work, particle size was tuned over a range of <100–500 nm, and its effect on nanoparticle–platelet interactions was systematically assessed using in vitro and in vivo experiments. Smaller particles bound a larger percentage of platelets per mass of particle delivered, while larger particles resulted in higher particle accumulation on a surface of platelets and collagen. Intermediate particles led to the greatest platelet content in platelet–nanoparticle aggregates, indicating that they may be able to recruit more platelets to the wound. In biodistribution studies, smaller and intermediate nanoparticles exhibited longer circulation lifetimes, while larger nanoparticles resulted in higher pulmonary accumulation. The particles were then challenged in a 2 h lethal inferior vena cava (IVC) puncture model, where intermediate nanoparticles significantly increased both survival and injury-specific targeting relative to saline and unfunctionalized particle controls. An increase in survival in the second hour was likewise observed in the smaller nanoparticles relative to saline controls, though no significant increase in survival was observed in the larger nanoparticle size. In conjunction with prior in vitro and in vivo experiments, these results suggest that platelet content in aggregates and extended nanoparticle circulation lifetimes are instrumental to enhancing hemostasis. Ultimately, this study elucidates the role of particle size in platelet–particle interactions, which can be a useful tool for engineering the performance of particulate hemostats and improving the design of these materials.

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Laparoscopic sleeve gastrectomy (LSG) effectively reduces weight by restricting gastric capacity and altering gut hormones levels. We designed a prospective study to investigate the correlation of serum uric acid (SUA) concentration and weight loss. SUA and body mass index (BMI) were measured preoperatively and on first postoperative month and year in patients who underwent LSG in our department of bariatric surgery. Data on 55 patients were analyzed. Preoperative SUA concentration had a significant positive correlation with percentage of total weight loss (TWL) on first postoperative month (P ¼ 0.001) and year (P ¼ 0.002). SUA concentration on first postoperative month had a positive correlation with percentage of TWL on first postoperative year (P ¼ 0.004). SUA concentration could be used as a predictor of LSG's success and could help in early detection of patients with rapid loss of weight, in order to prevent complications.Key words: Bariatric surgery -Metabolic syndrome -Weight loss -Uric acid M orbid obesity has reached epidemic proportions worldwide. In a recent epidemiological survey, the overall prevalence of obesity in Greece was estimated 22.5% (27.3% men and 25.7% women), while 35.2% of total population was found to be overweight (41.1% men and 29.9% women).1 Recent studies suggest that morbid obesity represents an important social and financial problem. Furthermore, morbid obesity is related with decreased overall survival, due to the related comorbidities, such as obstructive sleep apnea, hypoventilation syndrome, pulmonary hypertension, systemic hypertension, cholelithiasis, pancreatitis, fatty liver infiltration, cardiovascular disease, diabetes mellitus 2 Nowadays, LSG has proved its efficiency in weight loss and is used as a single bariatric operation. LSG achieves excess weight loss of 60 to 65% (in 3 years' follow up) and successful management of obesity comorbidities with resolution in about 45 to 95% of them. 3The mechanisms behind LSG weight-reducing actions are not yet fully elucidated. Reduction of the stomach capacity causing restriction in food intake is one of the most important mechanisms involved. Recent studies implicate that gut hormones and especially ghrelin may play a role in weight loss after LSG. 4Uric acid is the end product of purines (adenosine/guanosine) metabolism. Xanthine oxidase (XO) is the enzyme, responsible for the uric acid production. It converts hypoxanthine to xanthine and xanthine to uric acid (Fig. 1).5 Uric acid is produced mainly in the liver and intestine because of the high XO activity in those tissues. Serum uric acid (SUA) concentration is lower in women and children and increases with age. In postmenopausal women, SUA concentration is similar to this found in males. Normal values of SUA concentration are 3.5 to 7.2 mg/dL for adult men and 2.6 to 6.1 mg/dL for premenopausal women. It is obvious that concentration of SUA does not remain stable and it depends on genetic and environmental factors, the distortion of which can result to hyperuricemia. 6Uric ...

BACKGROUND Recent studies suggest that obesity is a risk factor for Clostridium difficile infection, possibly due to disruptions in the intestinal microbiome composition. We hypothesized that body mass index (BMI) is associated with increased incidence of C. difficile infection in surgical patients. METHODS In this nationwide retrospective cohort study in 680 American College of Surgeons National Surgical Quality Improvement Program participating sites across the United States, the occurrence of C. difficile infection within 30 days postoperatively between different BMI groups was compared. All American College of Surgeons National Surgical Quality Improvement Program patients between 2015 and 2016 were classified as underweight, normal-weight, overweight, or obese class I-III if their BMI was less than 18.5, 18.5 to 25, 25 to 30, 30 to 35, 35 to 40 or greater than 40, respectively. RESULTS A total of 1,426,807 patients were included; median age was 58 years, 43.4% were male, and 82.9% were white. The postoperative incidence of C. difficile infection was 0.42% overall: 1.11%, 0.56%, 0.39%, 0.35%, 0.33% and 0.36% from the lowest to the highest BMI group, respectively (p < 0.001 for trend). In univariate then multivariable logistic regression analyses, adjusting for patient demographics (e.g., age, sex), comorbidities (e.g., diabetes, systemic sepsis, immunosuppression), preoperative laboratory values (e.g., albumin, white blood cell count), procedure complexity (work relative unit as a proxy) and procedure characteristics (e.g., emergency, type of surgery [general, vascular, other]), compared with patients with normal BMI, high BMI was inversely and incrementally correlated with the postoperative occurrence of C. difficile infection. The underweight were at increased risk (odds ratio, 1.15 [1.00–1.32]) while the class III obese were at the lowest risk (odds ratio, 0.73 [0.65–0.81]). CONCLUSION In this nationwide retrospective cohort study, obesity is independently and in a stepwise fashion associated with a decreased risk of postoperative C. difficile infection. Further studies are warranted to explore the potential and unexpected association. LEVEL OF EVIDENCE Prognostic/Epidemiologic, Level IV.