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Despite the thorough investigation of graphene since 2004, altering its surface chemistry and reproducible functionalization remain challenging. This hinders fabrication of more complex hybrid materials with controlled architectures, and as a consequence the development of sensitive and reliable sensors and biological assays. In this contribution, we introduce DNA origami structures as nanopositioners for placing single dye molecules at controlled distances from graphene. The measurements of fluorescence intensity and lifetime of single emitters carried out for distances ranging from 3 to 58 nm confirmed the d–4 dependence of the excitation energy transfer to graphene. Moreover, we determined the characteristic distance for 50% efficiency of the energy transfer from single dyes to graphene to be 17.7 nm. Using pyrene molecules as a glue to immobilize DNA origami nanostructures of various shape on graphene opens new possibilities to develop graphene-based biophysics and biosensing.

Objective: Oxidative stress due to ischemia/reperfusion injury increases systemic inflammation and impairs immune defenses. Much interest has developed for the administration of antioxidant substrates in surgical patients. The purpose of this study was to perform a pilot evaluation of the impact of a carbohydrate- containing preconditioning oral nutritional supplement (pONS) enriched with glutamine, antioxidants, and green tea extract on postoperative oxidative stress. Methods: We performed a double-blind placebo-controlled randomized clinical trial, involving 36 cancer patients undergoing pancreaticoduodenectomy. Patients were randomized to receive either pONS or placebo twice the day before surgery and once 3 hours before surgery. Total endogenous antioxidant capacity (TEAC), plasma levels of vitamin C, vitamin E, selenium, zinc, F2-isoprostanes, and C-reactive protein were measured at baseline and on postoperative day (POD) 1, 3, and 7. Results: At surgery, the mean gastric residual volume (mL) was 54.2 in the pONS group versus 51.3 in the placebo group (P = NS). On POD 1 plasma levels of vitamin C (P = 0.001), selenium (P = 0.07), and zinc (P = 0.06) were higher in the pONS group compared to placebo. TEAC was improved on POD 1, 3, and 7 in the pONS group compared to placebo (P = 0.01). No difference was found in plasma C-reactive protein levels after surgery in both groups. Conclusions: Perioperative pONS administration positively affected plasma vitamin C levels and improved TEAC shortly after surgery, but did not reduce oxidative stress and systemic inflammation markers.

It is well known that nutrition and wound healing are closely related and optimal wound repair requires adequate nutritional intake. Malnutrition or specific nutrient deficiencies can lead to an impaired or delayed wound healing process and increased infection risk. Carbohydrates, fats and proteins are necessary for prompt healing, but also other nutrients play an important role in the wound healing process. Some amino acids, such as arginine and glutamine, vitamin C, A and E, and trace elements such as magnesium, copper, zinc and iron are crucial for wound healing. Diabetes mellitus is reaching epidemic proportions worldwide and it is well known that it impairs acute wound healing and favors the occurrence of chronic nonhealing foot wounds. Moreover, patients with diabetes need surgical care more frequently than nondiabetic subjects and it is necessary to understand the best way of caring for diabetic patients to improve their clinical outcome. Achieving and maintaining normal glucose control is a key factor for wound healing, particularly in diabetic patients.

Background Pneumoperitoneum (PP), established for laparoscopic (LPS) operation, has been associated with potential detrimental effects, such as mesenteric ischemia-reperfusion injury. The objective of the trial was to measure intestinal tissue oxygen pressure (PtiO2) and oxidative damage during laparoscopic (LPS) and open colon surgery and during the postoperative course. Methods Forty patients candidate to left-sided colectomy were randomized to undergo open or LPS resection (20 patients/group). During the operation, PtiO2 was measured at established changes of PP pressure (from 0-15 mmHg) and for 6 days postoperatively. P tiO2 was determined by a polarographic microprobe implanted in the colon wall. Ischemia-reperfusion injury was assessed by plasma malondialdehyde (MDA). ClinicalTrial.gov registration number: NCT01040013. Results LPS was associated with a higher PtiO2 at the beginning of surgery (73.9 ± 9.4 vs. 64.3 ± 6.4 in open; P = 0.04) and at the end of the operation (57.7 ± 7.9 vs. 53.1 ± 4.7 in open; P = 0.03). PtiO2 decreased significantly during mesentery traction vs. beginning in both groups (respectively 58.7 ± 13.2 vs. 73.9 ± 9.4 in LPS and 55.3 ± 6.4 vs. 64.3 ± 6.4 in open group; minimum P = 0.02). During LPS, there was a significant decrease of PtiO2 only when PP was increased to 15 mmHg (63.2 ± 7.5 vs. 76.6 ± 10.7 at 10 mmHg; P = 0.03). PtiO2 also was significantly better in the LPS group during the first 3 days after operation (minimum P = 0.04 vs. open). MDA significantly increased in both groups after mesentery traction and at the end of operation vs. baseline levels with no difference between techniques. Conclusions LPS seems to be associated with a better intra- and postoperative PtiO2. High-pressure PP may impair PtiO2.

AIM: To investigate whether probiotic bacteria, given perioperatively, might adhere to the colonic mucosa, reduce concentration of pathogens in stools, and modulate the local immune function. METHODS: A randomized, double-blind clinical trial was carried out in 31 subjects undergoing elective colorectal resection for cancer. Patients were allocated to receive either a placebo (group A, n = 10), or a dose of 107 of a mixture of Bifidobacterium longum (BB536 ) and Lactobacillus johnsonii (La1 ) (group B, n = 11), or the same mixture at a concentration of 109 (group C, n = 10). Probiotics, or a placebo, were given orally 2 doses/d for 3 d before operation. The same treatment continued postoperatively from day two to day four. Stools were collected before treatment, during surgery (day 0) and 5 d after operation. During the operation, colonic mucosa samples were harvested to evaluate bacterial adherence and to assess the phenotype of dendritic cells (DCs) and lymphocyte subsets by surface antigen expression (flow cytometry). The presence of BB536 and La1 was evaluated by the random amplified polymorphism DNA method with specific polymerase chain reaction probes. RESULTS: The three groups were balanced for baseline and surgical parameters. BB536 was never found at any time-points studied. At day 0, La1 was present in 6/10 (60%) patients in either stools or by biopsy in group C, in 3/11 (27.2%) in group B, and none in the placebo group (P = 0.02, C vs A). There was a linear correlation between dose given and number of adherent La1 (P = 0.01). The rate of mucosal colonization by enterobacteriacae was 30% (3/10) in C, 81.8% (9/11) in B and 70% (7/10) in A (P = 0.03, C vs B). The Enterobacteriacae count in stools was 2.4 (log10 scale) in C, 4.6 in B, and 4.5 in A (P = 0.07, C vs A and B). The same trend was observed for colonizing enterococci. La1 was not found at day +5. We observed greater expression of CD3, CD4, CD8, and naive and memory lymphocyte subsets in group C than

Background: Data on enhanced recovery programmes after pancreatic surgery are sparse. This retrospective cohort study, using historical controls, aimed to evaluate the impact of a fast-track programme after pancreaticoduodenectomy (PD). Methods: Between 2004 and 2007, 252 patients undergoing PD were treated by a fast-track programme that included earlier postoperative feeding and mobilization. The patients were compared with an equally sized control group that received a traditional programme from 2000 to 2004. Outcome measures were morbidity, length of stay and readmission rate. Results: The rates of pancreatic fistula and other intra-abdominal complications were similar in the two groups. Delayed gastric emptying (DGE) was significantly reduced in the fast-track group (13.9 versus 24.6 per cent; P = 0.004). The independent effect of the fast-track protocol in reducing DGE was confirmed by the multiple regression analysis (adjusted odds ratio 0.477, P = 0.005). Length of stay was reduced with the fast-track protocol (median 13 versus 15 days; P > 0.001), without increasing the readmission rate (7.1 versus 6.3 per cent; P = 0.865). Conclusion: A fast-track programme after PD improves gastric emptying and reduces postoperative stay. Copyright © 2008 British Journal of Surgery Society Ltd. Published by John Wiley & Sons Ltd.

Objective: To investigate whether probiotic bacteria given perioperatively may adhere to the colonic mucosa, reduce concentration of pathogens in stools, and modulate local immunefunction. Design: Prospective, randomized, double-blind, clinical trial Methods: Thirty-one patients undergoing elective colorectal resection for cancer were allocated to receive either placebo (group A, n = 10), or a dose of 107 of a mixture of Bifidobacterium longum (BB536) and Lactobacillus jonhsonii (La1) (group B, n = 11), or the same mixture at a concentration of 109 (group C, n = 10). Probiotics or placebo were given orally in 2 doses/day for 3 days before operation. The same treatment continued postoperatively from day 2 to 4. Stools were collected before treatment (day -4), during surgery (day 0), and 5 days after operation. During the operation, colonic mucosa samples were harvested to evaluate bacterial adherence and to phenotype dendritic cell subsets by surface antigen expression (flow cytometry). Presence of BB536 and La1 was evaluated by the random amplified polymorphism DNA method. Results: The 3 groups were balanced for baseline and surgical parameters. BB536 was never found at any time point studied. At day 0, La1 was present in 60% of patients in group C in either stools or biopsy, in 27.2% in B, and none in the placebo group (p = 0.02, group C vs. A). There was a linear correlation between dose given and number of adherent La1 (p = 0.01). The rate of mucosal colonization by Enterobacteriaceae was 30% in group C, 82% in group B, and 70% in group A (p = 0.03, C vs. B). Enterobacteriaceae count in stools was 2.4 (log10 scale) in C, 4.2 in B, and 4.5 in A (p = 0.07). The same trend was observed for colonizing enterococci. La1 was not found at day +5. After ex vivo stimulation with lipopolysaccharides, groups C and B had a lower proliferation rate compared with group A. Moreover, dendritic phenotypes CD83-123, CD83-HLADR, and CD83-11c (markers of activation) were significantl

OBJECTIVE: Mannose-binding lectin (MBL2) is a collectin molecule able to activate the complement system and the subsequent inflammatory mechanisms. Several MBL2 genetic variants have been described, including the six variants studied in this report, which are those analyzed in most detail in the medical literature. DESIGN: The present study analyzes the prevalence of MBL2 gene variants in preterm newborns and associates individual genotypes with pulmonary outcome variables. All polymorphisms were analyzed by means of a commercially available reverse dot-blot kit. SETTING: Tertiary neonatal intensive care unit. PATIENTS AND PARTICIPANTS: Seventy-five consecutive preterm newborns. MEASUREMENTS AND RESULTS: Two variants were particularly analyzed: -550G > C and R52C. The first one is known to be associated with lower protein synthesis when included in specific haplotypes. The homozygous and heterozygous -550G > C mutations were significantly associated with protective effects regarding different lung outcome variables, including shorter duration of mechanical ventilation, hours of continuous positive airway pressure and lower number of hemotransfusions. In contrast, the heterozygous R52C mutation was associated with unfavorable outcome, including higher bronchopulmonary dysplasia prevalence. Multivariate logistic regression analysis showed that these associations were independent of gestational age and birth weight. In addition, four groups of patients were defined on the basis of haplotype combinations. Those known to be associated with low serum MBL2 levels were linked to a better outcome in terms of factors such as hours of mechanical ventilation, continuous positive airway pressure, number of hemotransfusions and bronchopulmonary disease development. CONCLUSIONS: The four haplotype combination groups may have a potential diagnostic use as opposite risk factors for lung disease of prematurity

In the last years adding specific nutrients, such as arginine, omega-3 fatty acids and nucleotides, has modified standard enteral diets. These substrates have been shown to up-regulate host immune response, control inflammatory response, and improve nitrogen balance and protein synthesis after injury. Most randomized trials focused on clinical outcome have been carried out in gastrointestinal (GI) cancer patients undergoing elective surgery. When immunonutrition was limited to the postoperative period the results were conflicting, probably because the amount of substrates given in the first days after surgery was not sufficient to reach adequate tissue and plasma concentration quickly enough to be active. Better results on outcome were obtained when the immunoenhancing diet was administered before surgery. This enabled to reduce significantly the postoperative infection rate in either malnourished or well-nourished patients. Cost-benefit analyses showed that immunonutrition is cost-effective when compared to the standard treatment

Despite the thorough investigation of graphene since 2004, altering its surface chemistry and reproducible functionalization remain challenging. This hinders fabrication of more complex hybrid materials with controlled architectures, and as a consequence the development of sensitive and reliable sensors and biological assays. In this contribution, we introduce DNA origami structures as nanopositioners for placing single dye molecules at controlled distances from graphene. The measurements of fluorescence intensity and lifetime of single emitters carried out for distances ranging from 3 to 58 nm confirmed the d–4 dependence of the excitation energy transfer to graphene. Moreover, we determined the characteristic distance for 50% efficiency of the energy transfer from single dyes to graphene to be 17.7 nm. Using pyrene molecules as a glue to immobilize DNA origami nanostructures of various shape on graphene opens new possibilities to develop graphene-based biophysics and biosensing.