Metasurface-assisted Lab-on-fiber optrode for highly sensitive detection of vitamin D.

The increasing demand for vitamin D status assessment has highlighted the need for rapid, sensitive, and user-friendly methods for its detection in biological samples potentially integrated in Point-of-Care (PoC) diagnostic devices. Detection of the major circulating form of vitamin D, 25-hydroxyvitamin D3-25(OH)D3, is particularly challenging due to the laborious procedures for sample preparation and its low molecular weight (∼400 Da), which requires highly sensitive detection methods. In this study, we developed a novel label-free Lab-on-Fiber biosensing platform for highly sensitive detection of 25(OH)D3 based on the integration of plasmonic metasurfaces (MSs) on the tip of a single-mode optical fiber (OF). A dedicated pipeline was carefully designed and developed to optimize the bio-functionalization of the plasmonic sensor tip to specifically detect the target biomolecule. The resulting MS-assisted Lab-on-fiber platform enables direct and highly sensitive detection of 25(OH)D3 in clinically relevant ranges (4-160 ng/mL), both in buffer solution and complex matrix, with limits of detection (LOD) of 1.40 ng/mL in saline buffer and 0.85 ng/mL in complex matrix. Overall, these results demonstrate that our platform can successfully and specifically detect small molecules in label-free configuration, with performances comparable to those of conventional methods used in clinical practice. The high degree of miniaturization combined with its high sensitivity makes our platform an exceptional building block for realizing valid diagnostic alternatives for label-free detection of clinically relevant analytes, which can be transformed into new low-cost, fast, simple, and ready-to-use PoC diagnostic devices with improved processability and performance compared to current methods.

SERS assisted sandwich immunoassay platforms for ultrasensitive and selective detection of human Thyroglobulin.

We developed an immunoassay platform for the detection of human Thyroglobulin (Tg) to be integrated with fine-needle aspiration biopsy for early detection of lymph node metastases in thyroid cancer patients. The sensing platform detects Tg by a sandwich immunoassay involving a self-assembled surface-enhanced Raman scattering (SERS) substrate assisted by functionalized gold nanoparticles that provide additional Raman signal amplification and improved molecular specificity. Specifically, the SERS-active substrates were functionalized with Tg Capture antibodies and fabricated either on-chip or on optical fiber tips by nanosphere lithography. Gold nanoparticles were functionalized with Detection antibodies and conjugated with 4-mercaptobenzoic acid, which serves as a Raman reporter. The sandwich assay platform was validated in the planar configuration and a detection limit as low as 7 pg/mL was successfully achieved. Careful morphological examination of the SERS substrates before and after Tg measurements further assessed the effective capture of nanoparticles and correlated the average nanoparticle coverage with the Tg concentration obtained by SERS measurements. The sandwich assay was successfully demonstrated on washout fluids of fine needle aspiration biopsies from cancer patients and confirmed the high specificity of the proposed methodology when complex biological matrices are considered. Finally, SERS optrodes were fabricated and successfully used to detect Tg concentration by applying the same bio-recognition strategy and Raman interrogation through an optical fiber. This opens the possibility of transferring the Tg detection approach to the optical fiber tip to develop point-of-care platforms that can be directly integrated into fine needle aspiration biopsies.

Management of Small Bowel Obstruction (SBO) in older adults (>80 years): a propensity score-matched analysis on predictive factors for a (un)successful non-operative management (NOM).

OBJECTIVE: Small Bowel Obstruction (SBO) is a common emergency in older patients. The most appropriate treatment strategy is still matter of debate. The aim of this study was to compare a non-operative management (NOM) vs. a surgical procedure for patients ≥ 80 years with SBO. PATIENTS AND METHODS: All patients ≥ 80 years admitted to our Emergency Department (ED) for SBO between January 1st, 2015, and December 31st, 2020 were included in this study. In order to correct for baseline covariates and factors associated to clinical management, we used a 1:1 propensity score matching (PSM) analysis. The primary outcome was to compare the overall in-hospital mortality. Secondary outcomes included occurrence of major complications and in-hospital length of stay (LOS). RESULTS: A total of 561 patients were enrolled. After propensity score matching (PSM) analysis, 302 patients (151 each group) were included in the analysis. Mortality did not differ between the two groups. After PSM mechanical ventilation, sepsis, cumulative major complications, and LOS were significantly higher in the operative treatment group [15.9% vs. 1.5%, 9.4% vs. 4.1%, 27.6% vs. 19.2%, and 9.4 (6.4-14.3) days vs. 8.1 (4.5-13.3) days, respectively; p<0.001, p=0.013, p=0.025, and p=0.003, respectively]. CONCLUSIONS: In patients ≥ 80 years with SBO, a NOM could yield similar results, in terms of overall mortality, compared to a surgical management. Thus, particularly in patients with multiple comorbidities or functional impairments, a conservative approach should always be considered.

Nanocomposite hyaluronic acid-based hydrogel for the treatment of esophageal fistulas.

Fistulas are abnormal connections between two body parts that can impair the quality of life. The use of biological glues represents the least invasive procedure to fill the fistula; however, it is limited by the need of multiple injections, the persistence of infection and the failure in the treatment of high-output fistulas. We describe herein the use of an injectable nanocomposite hydrogel that is able to form in situ a tissue-mimicking matrix as an innovative material for the treatment of esophageal fistulas. Injectable hydrogels that have the dual advantage of being implantable with a minimally invasive approach and of adapting their shape to the target cavity, while the introduction of mesoporous silica nanoparticles opens the possibility of drug/biomolecules delivery. The hydrogel is based on hyaluronic acid (HA), the crosslinking process occurs at physiological conditions leading to a hydrogel made of >96% by water and with a large-pore micro-architecture. The kinetic profile of the hydrogel formation is studied as a function of HA molecular weight and concentration with the aim of designing a material that is easily injectable with an endoscopic needle, is formed in a time compatible with the surgical procedure and has final mechanical properties suitable for cell proliferation. The in vivo experiments (porcine model) on esophageal-cutaneous fistulas, showed improved healing in the animals treated with the hydrogel compared with the control group.

The impact of the multidisciplinary tumor board (MDTB) on the management of pancreatic diseases in a tertiary referral center.

BACKGROUND: The implementation of multidisciplinary tumor board (MDTB) meetings significantly ameliorated the management of oncological diseases. However, few evidences are currently present on their impact on pancreatic cancer (PC) management. The aim of this study was to evaluate the impact of the MDTB on PC diagnosis, resectability and tumor response to oncological treatment compared with indications before discussion. PATIENTS AND METHODS: All patients with a suspected or proven diagnosis of PC presented at the MDTB from 2017 to 2019 were included in the study. Changes of diagnosis, resectability and tumor response to oncological/radiation treatment between pre- and post-MDTB discussion were analyzed. RESULTS: A total of 438 cases were included in the study: 249 (56.8%) were presented as new diagnoses, 148 (33.8%) for resectability assessment and 41 (9.4%) for tumor response evaluation to oncological treatment. MDTB discussion led to a change in diagnosis in 54/249 cases (21.7%), with a consequent treatment strategy variation in 36 cases (14.5%). Change in resectability was documented in 44/148 cases (29.7%), with the highest discrepancy for borderline lesions. The treatment strategy was thus modified in 27 patients (18.2%). The MDTB brought a modification in the tumor response assessment in 6/41 cases (14.6%), with a consequent protocol modification in four (9.8%) cases. CONCLUSIONS: MDTB discussion significantly impacts on PC management, especially in high-volume centers, with consistent variations in terms of diagnosis, resectability and tumor response assessment compared with indications before discussion.

Noradrenergic fibers are associated with beta-cell dedifferentiation and impaired beta-cell function in humans.

AIMS/HYPOTHESIS: Type 2 diabetes (T2D) is characterized by a progressive loss of beta-cell function, and the "disappearance" of beta-cells in T2D may also be caused by the process of beta -cell dedifferentiation. Since noradrenergic innervation inhibits insulin secretion and density of noradrenergic fibers is increased in type 2 diabetes mouse models, we aimed to study the relation between islet innervation, dedifferentiation and beta-cell function in humans. METHODS: Using immunohistochemistry and electron microscopy, we analyzed pancreata from organ donors and from patients undergoing pancreatic surgery. In the latter, a pre-surgical detailed metabolic characterization by oral glucose tolerance test (OGTT) and hyperglycemic clamp was performed before surgery, thus obtaining in vivo functional parameters of beta-cell function and insulin secretion. RESULTS: The islets of diabetic subjects were 3 times more innervated than controls (0.91 ±â€¯0.21 vs 0.32 ±â€¯0.10, n.fibers/islet; p = 0.01), and directly correlated with the dedifferentiation score (r = 0.39; p = 0.03). In vivo functional parameters of insulin secretion, assessed by hyperglycemic clamp, negatively correlated with the increase in fibers [beta-cell Glucose Sensitivity (r = -0.84; p = 0.01), incremental second-phase insulin secretion (r = -0.84, p = 0.03) and arginine-stimulated insulin secretion (r = -0.76, p = 0.04)]. Moreover, we observed a progressive increase in fibers, paralleling worsening glucose tolerance (from NGT through IGT to T2D). CONCLUSIONS/INTERPRETATION: Noradrenergic fibers are significantly increased in the islets of diabetic subjects and this positively correlates with beta-cell dedifferentiation score. The correlation between in vivo insulin secretion parameters and the density of pancreatic noradrenergic fibers suggests a significant involvement of these fibers in the pathogenesis of the disease, and indirectly, in the islet dedifferentiation process.

Surgical emergencies during SARS-CoV-2 pandemic lockdown: what happened?

OBJECTIVE: The pandemic from SARS-CoV-2 is having a profound impact on daily life of a large part of world population. Italy was the first Western country to impose a general lockdown to its citizens. Implications of these measures on several aspects of public health remain unknown. The aim of this study was to investigate the effects of the lockdown on surgical emergencies volumes and care in a large, tertiary referral center. MATERIALS AND METHODS: Electronic medical records of all patients visited in our Emergency Department (ED) and admitted in a surgical ward from February 21st 2020 to May 3rd 2020 were collected, analyzed and compared with the same periods of 2019 and 2018 and a cross-sectional study was performed. RESULTS: Number of surgical admissions dropped significantly in 2020 with respect to the same periods of 2019 and 2018, by almost 50%. The percentage distribution of admissions in different surgical wards did not change over the three years. Time from triage to operating room significantly reduced in 2020 respect to 2019 and 2018 (p<0.001). CONCLUSIONS: The lockdown in Italy due to SARS-CoV-2 pandemic arguably represents the largest social experiment in modern times. Data provided by our study provide useful information to health authorities and policymakers about the effects of activity restriction on surgical accesses and changing epidemiology due to an exceptional external event.

Atypical presentation of acute pancreatitis: a single center case-match analysis of clinical outcomes.

OBJECTIVE: Acute pancreatitis (AP) may present an aspecific clinical picture without abdominal symptoms (atypical AP). We compared clinical outcomes between typical and atypical AP. PATIENTS AND METHODS: Thirty out of 1163 patients (2.6%) presented an atypical AP. Demographic, clinical data, laboratory and radiological findings, management type, length of hospital stay (LOS) and mortality rate were retrospectively reviewed. A case match analysis 2:1 was performed. The final groups comprised 50 typical APs (TAP group) and 25 atypical APs (AAP group). RESULTS: The AAP patients presented fever (36%), syncope (32%) and dyspnea (16%) as the most frequent symptoms. Laboratory values showed similarity between the two groups. We noted a comparable edematous AP rate in both groups (p=0.36). Ten (20%) TAP and 3 (12%) AAP patients needed ERCP, respectively (p=0.38). Cholecystectomy was similarly performed in both cohorts (p=0.81). One TAP patient underwent a percutaneous drainage and subsequent surgical necrosectomy compared to none in the AAP cohort (p=0.47). LOS and mortality rate were comparable (p=0.76 and 0.3, respectively). CONCLUSIONS: Similar outcomes have been reached in the two groups. Routine evaluation of the serum amylase values fundamentally contributed to early diagnosis and appropriate treatment.

The impact of preoperative ASA-physical status on postoperative complications and long-term survival outcomes in gastric cancer patients.

OBJECTIVE: The aim of this study was to investigate the impact of the preoperative American Society of Anesthesiologists-Physical status (ASA-PS) on both the short-term and long-term outcomes in patients with Gastric Cancer (GC). PATIENTS AND METHODS: In a retrospective observational study, a total of 473 GC patients were divided into the following 3 groups: ASA 1, ASA 2, and ASA 3-4. RESULTS: The ASA 3-4 group included significantly older patients compared to the other groups (p<0.0001). In ASA 1 patients, there was a higher number of lymph nodes dissected (p=0.006), and more patients received adjuvant treatment (p<0.001). In the three groups, no difference regarding the postoperative surgical and medical complications (p=0.29 and p=0.1, respectively) nor in terms of mortality rate (p=0.17) were demonstrated. The multivariate analysis showed that age, tumor stage, number of lymph nodes dissected, positive lymph nodes, adjuvant treatments, and postoperative surgical complications were significant predictive factors for mortality. Five-year overall and disease-free survival for ASA 1, ASA 2, and ASA 3-4 groups was 56%, 57.6%, and 44%, respectively; and 37%, 44.3%, and 39.2%, respectively. CONCLUSIONS: Preoperative ASA-PS alone cannot serve as a direct operative risk indicator for GC patients.

Colonoscopy quality assessment and accuracy: analysis of the influencing factors and surgical sequelae on 216 colonoscopies.

OBJECTIVE: Colonoscopy is recognized as the primary screening test for colorectal cancer. However, its inaccuracy in identifying the exact tumor localization is still high. As a consequence, repeated colonoscopies and changes in the surgical management have been reported. This study aims to evaluate the quality of 216 colonoscopies, to define colonoscopy accuracy and to investigate the surgical sequelae of an incorrect localization. PATIENTS AND METHODS: A retrospective analysis of 216 colonoscopies has been conducted. Colonoscopy quality was assessed on: quality of bowel preparation, completeness of the examination, video and/or photographic documentation, and reported the distance of the lesion from the anal verge. Colonoscopy accuracy was evaluated in terms of correspondence between the endoscopic and intra-operative tumor localization. RESULTS: Bowel preparation adequateness was reported in 121 out of 216 (56%) colonoscopies, with an adequate grade in 68.6% of cases. A complete colonoscopy was accomplished in 86.9% of cases with photo documentation in only 59 colonoscopies (27.3%). The lesion distance from the anal verge was documented only in 93 out of 216 colonoscopies. Of the 157 lesions described at the colonoscopy, 117 matched with the intra-operative localization (accuracy 74.5%). Fifteen of the 40 incorrectly localized lesions (37.5%) required changes in the surgical management. At multivariate analysis, the colonoscopy completeness was the only influencing factor on the concordance between endoscopic and intra-operative localization. CONCLUSIONS: Colonoscopy demonstrated adequate accuracy in localizing lesions. However, the incorrect tumor localization leads to a high rate of changes in surgical management. Increase in.

Laser ablation in biliary tree: analysis of the intraductal and superficial thermal effects during the treatment.

The treatment of choice for the unresectable cholangiocarcinoma is based on biliary decompression procedures. Despite stent placement is the standard of care, it is related to well-known complications. Hence, alternative techniques were proposed. Ideally, they should guarantee an adequate intraductal disobstruction, without injuring the surrounding tissues.This pre-clinical study aims to investigate the thermal effects of the laser ablation (LA) in the biliary tree, in terms of intraductal and surrounding tissue temperature achieved with different laser settings. The common bile ducts (in their upper and lower portions) of two pigs were ablated for 6 minutes with a diode laser at 3 W and 5 W. A custom-made laser applicator was used to obtain a circumferential ablation within the ducts. The intraductal temperature (Tid) was monitored by means of a fiber Bragg grating (FBG) sensor, while an infrared thermal camera monitored the T distribution in the surrounding tissues (Tsup). A maximum T difference of 65 °C and 57 °C was evidenced between the two power settings for the Tid measured in the upper and lower ducts, respectively. The mean difference between Tid and the averaged Tsup values was evaluated. At 5 W, a difference of 37±3 °C and 44±10 °C were obtained for the upper and lower ducts, respectively. At 3 W, a T difference of 2±1 °C was obtained for the upper biliary duct, while a difference of 8±1 °C was documented for the lower duct. Based on the results obtained in this preliminary study, the possibility to equip the laser probe with temperature sensor can improve the control and the safety of the procedure; this solution will guarantee the monitoring of the treatment while preserving the lumen and the surrounding structures.

Long-term pancreatic exocrine and endometabolic functionality after pancreaticoduodenectomy. Comparison between pancreaticojejunostomy and pancreatic duct occlusion with fibrin glue.

OBJECTIVE: Even if pancreatic pathologies, residual fibrosis, residual amount of parenchyma, and anastomotic patency are recognized as main causes of exocrine and glycemic impairment after pancreaticoduodenectomy (PD), few data are reported concerning the role of the different pancreatic remnant treatment techniques. The objective of the study is to assess and compare exocrine functionality, glycemic pattern, nutritional status, and quality of life (QoL) after PD between pancreaticojejunostomy (PJ) and pancreatic duct occlusion (PDO), both in an objective and a subjective manner. PATIENTS AND METHODS: Thirty-two patients (16 PJ and 16 PDO) were evaluated after a mean follow-up of 21 months after surgery. Exocrine insufficiency was objectively evaluated through the 13C-labelled mixed triglyceride breath test. Fasting glucose, fasting insulin, HbA1c and HOMA-IR values were used to assess glucose metabolism. For these two outcomes, anamnestic data were also collected. QoL was assessed with GIQLI, SF-36, EORTC-QLQ-C30, and EORTC-PAN-26 questionnaires. RESULTS: The 13C-labelled mixed triglyceride breath test detected a lipid digestive insufficiency in 56% of patients after PJ and 100% after PDO respectively (p = 0.007). However, no difference was observed between the two groups regarding postoperative necessity of substitutive pancreatic enzymes. Nutritional status, fasting plasma glucose, fasting insulin, HbA1c levels, HOMA-IR values and postoperative necessity of insulin or oral antidiabetic agents were comparable between the two groups. QoL measurements showed similar results. However, in the subdomains analysis, better outcomes were reported regarding digestive symptoms and physical functioning for PJ and PDO respectively. CONCLUSIONS: Even if an objective exocrine major impairment was evidenced after PDO, this result did not impact the need for a higher rate of postoperative substitutive enzymes. In terms of glycemic pattern, nutritional status, and QoL, the two techniques turn out to be comparable.

Treatment of giant paraesophageal hernia: pro laparoscopic approach.

PURPOSE: Giant paraesophageal hernias (GPEH) are relatively uncommon and account for less than 5% of all primary hiatal hernias. Giant Secondary GPEH can be observed after surgery involving hiatal orifice opening, such as esophagectomy, antireflux surgery, and hiatal hernia repair. Surgical treatment is challenging, and there are still residual controversies regarding the laparoscopic approach, even though a reduced morbidity and mortality, as well as a shorter hospital stay have been demonstrated. METHODS: A Pubmed electronic search of the literature including articles published between 1992 and 2016 was conducted using the following key words: hiatal hernia, paraesophageal hernias, mesh, laparoscopy, intrathoracic stomach, gastric volvulus, diaphragmatic hernia. RESULTS: Given the risks of non-operative management, GPEH surgical repair is indicated in symptomatic patients. Technical steps for primary hernia repair include hernia reduction and sac excision, correct repositioning of the gastroesophageal junction, crural repair, and fundoplication. For secondary hernias, the surgical technique varies according to hernia type and components and according to the approach used during the first surgery. There is an ongoing debate regarding the best and safest method to close the hiatal orifice. The laparoscopic approach has demonstrated a lower postoperative morbidity and mortality, and a shorter hospital stay as compared to the open approach. A high recurrence rate has been reported for primary GPEH repair. However, recent studies suggest that recurrence does not reduce symptomatic outcomes. CONCLUSIONS: The laparoscopic treatment of primary and secondary GPEH is safe and feasible in elective and emergency settings, especially in high-volume centers. The procedure is still challenging. The main steps are well defined. However, there is still room for improvement to lower the recurrence rate.

Tapered fiber optic applicator for laser ablation: Theoretical and experimental assessment of thermal effects on ex vivo model.

Laser Ablation (LA) is a minimally invasive technique for tumor removal. The laser light is guided into the target tissue by a fiber optic applicator; thus the physical features of the applicator tip strongly influence size and shape of the tissue lesion. This study aims to verify the geometry of the lesion achieved by a tapered-tip applicator, and to investigate the percentage of thermally damaged cells induced by the tapered-tip fiber optic applicator. A theoretical model was implemented to simulate: i) the distribution of laser light fluence rate in the tissue through Monte Carlo method, ii) the induced temperature distribution, by means of the Bio Heat Equation, iii) the tissue injury, by Arrhenius integral. The results obtained by the implementation of the theoretical model were experimentally assessed. Ex vivo porcine liver underwent LA with tapered-tip applicator, at different laser settings (laser power of 1 W and 1.7 W, deposited energy equal to 330 J and 500 J, respectively). Almost spherical volume lesions were produced. The thermal damage was assessed by measuring the diameter of the circular-shaped lesion. The comparison between experimental results and theoretical prediction shows that the thermal damage discriminated by visual inspection always corresponds to a percentage of damaged cells of 96%. A tapered-tip applicator allows obtaining localized and reproducible damage close to spherical shape, whose diameter is related to the laser settings, and the simple theoretical model described is suitable to predict the effects, in terms of thermal damage, on ex vivo liver. Further trials should be addressed to adapt the model also on in vivo tissue, aiming to develop a tool useful to support the physician in clinical application of LA.

Effects of Nd:YAG laser for the controlled and localized treatment of early gastrointestinal tumors: Preliminary in vivo study.

Endoscopic submucosal dissection (ESD) is a minimally invasive technique allowing for the removal of early gastrointestinal (GI) tumors, widely considered as a valid alternative to conventional surgery. However, ESD is technically demanding, and potentially severe complications, such as bleeding and perforation, may occur. Energy-based techniques (e.g., radiofrequency ablation) might offer a potential alternative to ESD. However, their use mandates the ability to predict the damage induced and to identify a "signature" of the complete ablation, without the need for a physical specimen. Ideally, an energy-based procedure should be tunable in order to limit the ablation to the superficial layers, namely mucosa (M) and submucosa (SM), without injuring the muscularis propria (MP), thereby minimizing GI perforation. This experimental study aims to investigate thermal damage induced by Nd:YAG laser on the gastric wall, at different laser settings such as power (P) and time (t). Laser ablation was performed on the stomach wall of 6 Wistar rats. Two powers (2.5W and 1.0W) and 3 exposure times (12s, 6s and 2s) were tested, for a total of 30 ablations. Histological analysis allowed to assess thermal damage, in terms of damage depth (DD) and identification of involved layers. The ratio (R) between DD and the total depth (TD) of target layers (M+SM) was used as an index to evaluate the effectiveness of laser settings. At P=2.5W, MP was damaged (R>1) in the majority of cases (11/15). At P=1.0W, MP was preserved in all tests (R<;1), and rarely (4/15) did the damage reach the whole SM (R=1). Histopathological analysis evidenced that tissue damage was strongly related to the variable tissue thickness. These preliminary results seem to support the fact that endoscopic tunable laser ablation is feasible with a consistent damage/power correlation. Further tests are required to optimize the settings for applications on early GI tumors.

Distribution of Escherichia coli in a coastal lagoon (Venice, Italy): Temporal patterns, genetic diversity and the role of tidal forcing.

Despite its worldwide importance as fecal indicator in aquatic systems, little is known about the diversity of Escherichia coli in the environment and the factors driving its spatial distribution. The city of Venice (Italy), lying at the forefront of a large European lagoon, is an ideal site to study the mechanisms driving the fate of fecal bacteria, due to the huge fluxes of tourists, the city's unique architecture (causing poor efficiency of sewages treatment), and the long branching network of canals crossing the city. We summarize the results of a multi-year investigation to study the temporal dynamics of E. coli around the city, describe the population structure (by assigning isolates to their phylogenetic group) and the genotypic diversity, and explore the role of environmental factors in determining its variability. E. coli abundance in water was highly variable, ranging from being undetectable up to 10(4) Colony Forming Units (CFU) per 100 ml. Abundance did not display significant relationships with the water physico-chemical variables. The analysis of the population structure showed the presence of all known phylogroups, including extra-intestinal and potentially pathogenic ones. The genotypic diversity was very high, as likely consequence of the heterogeneous input of fecal bacteria from the city, and showed site-specific patterns. Intensive sampling during the tidal fluctuations highlighted the prominent role of tides, rather than environmental variables, as source of spatial variation, with a more evident influence in water than sediments. These results, the first providing information on the genetic properties, spatial heterogeneity and influence of tides on E. coli populations around Venice, have implications to manage the fecal pollution, and the associated waterborne disease risks, in coastal cities lying in front of lagoons and semi-enclosed basins.

Simple technique for integrating compact silicon devices within optical fibers.

In this work, we present a simple fabrication process enabling the integration of a subwavelength amorphous silicon layer inside optical fibers by means of the arc discharge technique. To assess our method, we have fabricated a compact in-line Fabry-Perot interferometer consisting of a thin (<1 µm) a-Si:H layer completely embedded within a standard single-mode optical fiber. The device exhibits low loss (1.3 dB) and high interference fringe visibility (~80%) both in reflection and transmission, due to the high refractive index contrast between silica and a-Si:H. A high linear temperature sensitivity up to 106 pm/°C is demonstrated in the range 120°C-400°C. The proposed interferometer is attractive for point monitoring applications as well as for ultrahigh-temperature sensing in harsh environments.

Complications related to hyperthermia during hypertermic intraoperative intraperitoneal chemiotherapy (HIPEC) treatment. Do they exist?

BACKGROUND AND OBJECTIVES: Hyperthermia, either alone or in combination with anticancer drugs, is becoming more and more a clinical reality for the treatment of far advanced gastrointestinal cancers, acting as a cytotoxic agent at a temperature between 40-42.5 degrees C. Although hyperthermic intraoperative intraperitoneal chemotherapy (HIPEC) is demonstrated to have some benefit in selected patients with peritoneal seeding, there are not enough data on the risk of damage of normal tissue that increases as the temperature rises, with possible serious and, sometimes, lethal complications. MATERIALS AND METHODS: We searched on medline words like "intraoperative intraperitoneal chemohyperthermia and morbidity", focusing our attention on studies (published since 1990) which reported morbidity as bowel obstruction, bowel perforation or anastomic leak, during intraoperative intraoperitoneal chemotherapy in hyperthermia (HIPEC). RESULTS: Heat acts increasing cancer cell killing after exposure to ionizing radiation, inhibiting repairing processes of radiation-induced DNA lesions (radiosensitization), and also sensitizing cancer cells to chemotherapeutic drugs, particularly to alkylating agents (chemosensitization). The peritoneal carcinomatosis (a frequent evolution of advanced digestive cancer) represents one of the main indication to hypertermic treatment. In the last fifteen years, in fact, different methods were developed for the surgery treatment (peritonectomy) and for loco-regional chemotherapic treatment of the carcinomatosis (intraperitoneal intra/post-operative iper/normothermic chemotherapy) to act directly on neoplastic seeding. We found, as result of different studies, 9 articles, written about perforation after HIPEC. CONCLUSION: The aim of the present study is to present the review of the literature in terms of peri-operative complications related to the hyperthermia during intraoperative chemohyperthermia procedure.

Role of oxidized regenerated cellulose in preventing infections at the surgical site: prospective, randomized study in 98 patients affected by a dirty wound.

AIM: The aim of this study was to evaluate whether oxidized regenerated cellulose (ORC), applied to "dirty" surgical wounds, is able to reduce the microbial load and, consequently, the infection rate as compared to conventional local wound treatment. METHODS: The study included 98 patients who underwent intestinal recanalization procedures between December 2003 and December 2008, with the stoma as the surgical site. Authors considered several risk factors for SSI. The patients were divided into two groups. In group A (50 patients), the surgical wound, previous site of the stoma, was packed with ORC, whereas in group B (48 patients) gauze soaked in iodine was used. Microbial contamination was evaluated with three swabs (in subcutaneous tissue and the dermis), in the operating room before wound packing and on the 2nd and 3rd postoperative day (before suturing the skin). RESULTS: There were no cases of wound dehiscence and no clinically evident superficial or deep surgical site infections in either group. Analysis of all data revealed that there was no or reduced bacterial contamination in the second and third swab in 33 patients (66%) of Group A versus 12 patients (25%) of Group B. CONCLUSION: Although it is necessary to consider all factors which can have an influence on SSI and use all the means shown to be effective to reduce the risk of SSI, there is a rationale for using ORC to prevent this kind of infection, especially in patients who undergo "dirty" surgery.