Laparoscopic Tissue Retractor Based on Local Magnetic Actuation

Magnetic instruments for laparoscopic surgery have the potential to enhance triangulation and reduce invasiveness, as they can be rearranged inside the abdominal cavity and do not need a dedicated port during the procedure. Onboard actuators can be used to achieve a controlled and repeatable motion at the interface with the tissue. However, actuators that can fit through a single laparoscopic incision are very limited in power and do not allow performance of surgical tasks such as lifting an organ. In this study, we present a tissue retractor based on local magnetic actuation (LMA). This approach combines two pairs of magnets, one providing anchoring and the other transferring motion to an internal mechanism connected to a retracting lever. Design requirements were derived from clinical considerations, while finite element simulations and static modeling were used to select the permanent magnets, set the mechanism parameters, and predict the lifting and supporting capabilities of the tissue retractor. A three-tier validation was performed to assess the functionality of the device. First, the retracting performance was investigated via a benchtop experiment, by connecting an increasing load to the lever until failure occurred, and repeating this test for different intermagnetic distances. Then, the feasibility of liver resection was studied with an ex vivo experiment, using porcine hepatic tissue. Finally, the usability and the safety of the device were tested in vivo on an anesthetized porcine model. The developed retractor is 154 mm long, 12.5 mm in diameter, and weights 39.16 g. When abdominal wall thickness is 2 cm, the retractor is able to lift more than ten times its own weight. The model is able to predict the performance with a relative error of 9.06 ± 0.52%. Liver retraction trials demonstrate that the device can be inserted via laparoscopic access, does not require a dedicated port, and can perform organ retraction. The main limitation is the reduced mobility due to the length of the device. In designing robotic instrument for laparoscopic surgery, LMA can enable the transfer of a larger amount of mechanical power than what is possible to achieve by embedding actuators on board. This study shows the feasibility of implementing a tissue retractor based on this approach and provides an illustration of the main steps that should be followed in designing a LMA laparoscopic instrument

Natural and anthropogenic variations in the Po river waters (northern Italy): insights from a multi-isotope approach

Po is the main Italian river and the δ18O and δ2H of its water reveal a similarity between the current meteoric fingerprint and that of the past represented by groundwater. As concerns the hydrochemisty, the Ca–HCO3 facies remained constant over the last 50 year, and only nitrate significantly increased from less than 1 mg/L to more than 10 mg/L in the 1980s, and then attenuated to a value of 9 mg/L. Coherently, δ13C and δ34S are compatible with the weathering of the lithologies outcropping in the basin, while extremely variable δ15NNO3 indicates contribution from pollutants released by urban, agricultural and zootechnical activities. This suggests that although the origin of the main constituents of the Po river water is geogenic, anthropogenic contributions are locally significant. Noteworthy, the associated aquifers have the same nitrogen isotopic signature of the Po river, but are characterized by significantly higher NO3 concentration. This implies that aquifers’ pollution is not ascribed to inflow of current river water, and that the attenuation of the nitrogen load recorded in the river is not occurring in the aquifers, due to their longer water residence time and delayed recovery from anthropogenic contamination

Tracing geogenic and anthropogenic sources in the Po river dissolved load with a multi isotope approach.

The Po river cross Northern Italy and flows within a densely populated area characterized by intense agriculture and industrial activities. The presented data represent a follow up of a previous study that discussed dissolved components and oxygen-hydrogen isotope composition of its waters in distinct seasons of the year 2012, all along the river course [1]. In this contribution the study of Po river water is implemented with further sampling campaigns of the year 2013, to provide a more complete chemical and multi-isotopic investigation. δ18O-δD data on riverine waters conform to the meteoric trends, and their analogies with the local groundwater rule out significant warming trends. The comparison of the new data with historical analyses indicates that the Ca-HCO3 hydrochemical facies remained constant over the decades; in contrast, nitrate drastically increases from less than 1 mg/L to an average value of 9 mg/L. δ13C (between -11.4‰ and -4.4‰) and δ34S (between 4.2‰ and 8.0‰) are compatible with the weathering and dissolution processes that involve the lithologies outcropping in the basin, while extremely variable δ15N (between -4.1‰ and 18.0‰) indicates contribution of pollutants from mixed anthropogenic sources (urban wastewater, agricultural and zootechnical activities). These observations suggest that although the origin of the main constituents of the Po river water is geogenic, anthropogenic contributions are also effective. [1] Marchina et al(2015) Environ. Sci. Pollut. R. 22, 5184-5203

The Po river water from the Alps to the Adriatic Sea (Italy): new insights from geochemical and isotopic (δ18O-δD) data

Although the Po river is the most important fluvial system of Northern Italy, the systematic geochemical and isotopic investigations of its water are rare and were never reported for the whole basin. The present contribution aims to fill this knowledge gap, reporting a comprehensive data-set including oxygen and hydrogen stable isotopes, as well as major and trace element concentration of dissolved species for 54 Po river water samples, mainly collected in different hydrological conditions (peak discharge in April, drought in August) at increasing distance from the source, i.e. from the upper part of the catchment to the terminal (deltaic) part of the river at the confluence with the Adriatic Sea. The isotopic compositions demonstrate that the predominant part of the runoff derives from the Alpine sector of the catchment through important tributaries such as Dora Baltea, Ticino, Adda and Tanaro rivers, whereas the contribution from the Apennines tributaries is less important. The geochemical and isotopic compositions show that the Po river water attains a homogeneous composition at ca. 100 km from the source. The average composition is characterized by delta18O -9.8‰, deltaD – 66.2‰, TDS (Total Dissolved Solids) 268 mg/L, chloride 17 mg/L and by a general Ca–HCO3 hydrochemical facies, which is maintained for most of the river stream, only varying in the terminal part where the river is diverted in a complex deltaic system affected by more significant evaporation and mixing with saline water evidenced by higher TDS and chloride content (up to 8,198 mg/L and 4,197 mg/L, respectively). Geochemical and isotopic maps have been drawn to visualize spatial gradients, which reflect the evolution of the river water composition at progressive distance from the source; more detailed maps were focused on the deltaic part in order to visualize the processes occurring in the transitional zone toward the Adriatic Sea. The data also highlight anthropogenic contributions, mainly represented by significant concentrations of nitrate (average 8 mg/L) and possibly arsenic (average 12 μg/L). These data allow the calculation of geochemical fluxes transferred from the river to the sea, and generally they contribute to the definition of a “hydro-archive” which is useful to highlight ongoing variations in the related ecosystems

Coupled Plasma Filtration Adsorption Application for Liver and Thyroid Toxins

none6noCoupled plasma filtration and adsorption (CPFA) is a detoxification system that combines a plasma adsorption circuit and a continuous renal replacement therapy circuit. Its main application is for sepsis and septic shock with or without acute renal failure. Several recent studies have suggested that CPFA can reduce the mortality when the volume of plasma absorbed on the styrenic resin is at least >0.18 L/kg/day. At present, new applications for CPFA are under investigation, also in patients without significant kidney failure. We report here a successful case of CPFA use during acute liver failure, with a complete recovery of liver function in a patient after severe cholangitis and relapsing hemolytic anemia. The resin enabled the removal of bilirubin and protein-bound toxins, while the hemofilter removed the hydrophilic toxins such as ammonia and non-protein-bound toxins as free bilirubin. We also describe a second case of CPFA application during thyrotoxicosis to achieve free triiodothyronine (FT3) and free thyroxin (FT4) adsorptions. The CPFA efficacy seems to exceed that obtained by plasma exchange (PEX) as to FT3 and FT4 adsorptions. The resin allowed the adsorption of FT3 and FT4. The role of the hemofilter is to enhance the hemodynamic tolerance of the extracorporeal treatment and remove water-soluble toxins. The reduced duration of CPFA treatments, in case of normal renal function, is confirmed by the assessment of the resin cartridge saturation. Thus, multipurpose CPFA can play a role in the case of resistance to current medical therapy or as a bridge to liver transplantation or thyroidectomy.mixedmixedDonati, Gabriele; Capelli, Irene; Chiocchini, Anna Laura Croci; Natali, Nicolò; Scrivo, Anna; La Manna, GaetanoDonati, Gabriele; Capelli, Irene; Chiocchini, Anna Laura Croci; Natali, Nicolò; Scrivo, Anna; La Manna, Gaetan

Haemodynamic and metabolic phenotyping of hypertensive patients with and without heart failure by combining cardiopulmonary and echocardiographic stress test

Aim We combined cardiopulmonary exercise test (CPET) and exercise stress echocardiography (ESE) to identify early haemodynamic and metabolic alterations in patients with hypertension (HT) with and without heart failure with preserved ejection fraction (HFpEF). Methods and results Fifty stable HFpEF‐HT outpatients (mean age 68 ± 14 years) on optimal medical therapy, 63 well‐controlled HT subjects (mean age 63 ± 11 years) and 32 age and sex‐matched healthy controls (mean age 59 ± 15 years) underwent a symptom‐limited graded ramp bicycle CPET‐ESE. The acquisition protocol included left ventricular cardiac output, global longitudinal strain, E/e′, peak oxygen consumption (VO2), non‐invasive arterial–venous oxygen content difference (AVO2diff) and lung ultrasound B‐lines. There was a decline in peak VO2 from controls (24.4 ± 3 mL/min/kg) to HFpEF‐HT (15.2 ± 2 mL/min/kg), passing through HT (18.7 ± 2 mL/min/kg; P  < 0.0001). HFpEF‐HT displayed a lower peak cardiac output (9.8 ± 0.9 L/min) compared to HT (12.6 ± 1.0 L/min; P = 0.02) and controls (13.3 ± 1.0 L/min; P = 0.01). Peak AVO2diff was reduced in HFpEF‐HT and HT (13.3 ± 2 and 13.5 ± 2 mL/dL vs. controls: 16.9 ± 2 mL/dL; P < 0.0001). A different left ventricular contractility was observed among groups, expressed as low‐load global longitudinal strain (−16.8 ± 5% in HFpEF‐HT, −18.2 ± 3% in HT, and 20.9 ± 3% in controls; P < 0.0001), and distribution of E/e′ and B‐lines [HFpEF‐HT: 13.7 ± 3 and 16, interquartile range (IQR) 10–22; HT: 9.5 ± 2 and 8, IQR 4–10; controls: 6.2 ± 2 and 0, IQR 0–2; P < 0.0001]. Conclusions Reduced peak VO2 values in HT with and without HFpEF may be the result of decreased AVO2diff. CPET‐ESE can also identify mild signs of left ventricular systo‐diastolic dysfunction and pulmonary congestion, promoting advances in personalized therapy

Overexpression and activation of hepatocyte growth factor/scatter factor in human non-small-cell lung carcinomas

Hepatocyte growth factor/scatter factor (HGF/SF) stimulates the invasive growth of epithelial cells via the c-MET oncogene-encoded receptor. In normal lung, both the receptor and the ligand are detected, and the latter is known to be a mitogenic and a motogenic factor for both cultured bronchial epithelial cells and non-small-cell carcinoma lines. Here, ligand and receptor expression was examined in 42 samples of primary human non-small-cell lung carcinoma of different histotype. Each carcinoma sample was compared with adjacent normal lung tissue. The Met/HGF receptor was found to be 2 to 10-fold increased in 25% of carcinoma samples (P = 0.0113). The ligand, HGF/SF, was found to be 10 to 100-fold overexpressed in carcinoma samples (P &lt; 0.0001). Notably, while HGF/SF was occasionally detectable and found exclusively as a single-chain inactive precursor in normal tissues, it was constantly in the biologically-active heterodimeric form in carcinomas. Immunohistochemical staining showed homogeneous expression of both the receptor and the ligand in carcinoma samples, whereas staining was barely detectable in their normal counterparts. These data show that HGF/SF is overexpressed and consistently activated in non-small-cell lung carcinomas and may contribute to the invasive growth of lung cancer