Sensing of Continuum Robots: A Review.

The field of continuum robotics is rapidly developing. The development of new kinematic structures, locomotion principles and control strategies is driving the development of new types of sensors and sensing methodologies. The sensing in continuum robots can be divided into shape perception and environment perception. The environment perception is focusing on sensing the interactions between the robot and environment. These sensors are often embedded on an outer layer of the robots, so the interactions can be detected. The shape perception is sensing the robot's shape using various principles. There are three main groups of sensors that use the properties of electricity, magnetism and optics to measure the shape of the continuum robots. The sensors based on measuring the properties of electricity are often based on measuring the electrical resistance or capacitance of the flexible sensor. Sensors based on magnetism use properties of permanent magnets or coils that are attached to the robot. Their magnetic field, flux or other properties are then tracked, and shape reconstruction can be performed. The last group of sensors is mostly based on leveraging the properties of traveling light through optical fibers. There are multiple objectives of this work. Objective number one is to clearly categorize the sensors and make a clear distinction between them. Objective number two is to determine the trend and progress of the sensors used in continuum robotics. And finally, the third objective is to define the challenges that the researchers are currently facing. The challenges of sensing the shape or the interaction with the environment of continuum robots are currently in the miniaturization of existing sensors and the development of novel sensing methods.

Galanin System in the Human Bile Duct and Perihilar Cholangiocarcinoma.

BACKGROUND: Perihilar cholangiocarcinoma (pCCA) is characterised by poor outcomes. Early diagnosis is essential for patient survival. The peptide galanin (GAL) and its receptors GAL1-3 are expressed in various tumours. Detailed characterisation of the GAL system in pCCA is lacking. Our study sought to characterise GAL and GAL1-3 receptor (GAL1-3-R) expression in the healthy human bile duct, in cholestasis and pCCA. METHODS: Immunohistochemical staining was performed in healthy controls (n = 5) and in the peritumoural tissues (with and without cholestasis) (n = 20) and tumour tissues of pCCA patients (n = 33) using validated antibodies. The score values of GAL and GAL1-3-R expression were calculated and statistically evaluated. RESULTS: GAL and GAL1-R were expressed in various bile duct cell types. GAL2-R was only slightly but still expressed in almost all the examined tissues, and GAL3-R specifically in cholangiocytes and capillaries. In a small pCCA patient cohort (n = 18), high GAL expression correlated with good survival, whereas high GAL3-R correlated with poor survival. CONCLUSIONS: Our in-depth characterisation of the GAL system in the healthy human biliary duct and pCCA in a small patient cohort revealed that GAL and GAL3-R expression in tumour cells of pCCA patients could potentially represent suitable biomarkers for survival.

Clinical Outcomes After Total Pancreatectomy: A Prospective Multicenter Pan-European Snapshot Study.

OBJECTIVE: To assess outcomes among patients undergoing total pancreatectomy (TP) including predictors for complications and in-hospital mortality. BACKGROUND: Current studies on TP mostly originate from high-volume centers and span long time periods and therefore may not reflect daily practice. METHODS: This prospective pan-European snapshot study included patients who underwent elective (primary or completion) TP in 43 centers in 16 European countries (June 2018-June 2019). Subgroup analysis included cutoff values for annual volume of pancreatoduodenectomies (<60 vs ≥60).Predictors for major complications and in-hospital mortality were assessed in multivariable logistic regression. RESULTS: In total, 277 patients underwent TP, mostly for malignant disease (73%). Major postoperative complications occurred in 70 patients (25%). Median hospital stay was 12 days (IQR 9-18) and 40 patients were readmitted (15%). In-hospital mortality was 5% and 90-day mortality 8%. In the subgroup analysis, in-hospital mortality was lower in patients operated in centers with ≥60 pancreatoduodenectomies compared <60 (4% vs 10%, P = 0.046). In multivariable analysis, annual volume <60 pancreatoduodenectomies (OR 3.78, 95% CI 1.18-12.16, P = 0.026), age (OR 1.07, 95% CI 1.01-1.14, P = 0.046), and estimated blood loss ≥2L (OR 11.89, 95% CI 2.64-53.61, P = 0.001) were associated with in-hospital mortality. ASA ≥3 (OR 2.87, 95% CI 1.56-5.26, P = 0.001) and estimated blood loss ≥2L (OR 3.52, 95% CI 1.25-9.90, P = 0.017) were associated with major complications. CONCLUSION: This pan-European prospective snapshot study found a 5% inhospital mortality after TP. The identified predictors for mortality, including low-volume centers, age, and increased blood loss, may be used to improve outcomes.

Impact of the COVID-19 pandemic lockdown on the utilization of acute surgical care in the State of Salzburg, Austria: retrospective, multicenter analysis.

BACKGROUND: Some medical disciplines have reported a strong decrease of emergencies during the coronavirus disease 2019 (COVID-19) pandemic; however, the effect of the lockdown on general surgery emergencies remains unclear. METHODS: This study is a retrospective, multicenter analysis of general surgery emergency operations performed during the period from 1 March to 15th 2020 lockdown and in the same time period of 2019 in three medical centers providing emergency surgical care to the area Salzburg-North, Austria. RESULTS: In total 165 emergency surgeries were performed in the study period of 2020 compared to 287 in 2019. This is a significant decrease of 122 (42.5%) emergency surgeries during the COVID-19 lockdown (p = 0.005). The length of hospital stay was reduced to 3 days in 2020 compared to 4 in 2019. Appendectomy remained the most performed emergency surgery for both periods; however the number of surgeries was reduced to less than a half, with 72 cases in 2019 and 33 cases in 2020 (p = 0.118). Emergency colon surgery observed the strongest decrease of 75% from 17 cases in 2019 to 4 in 2020. In addition, the emergency abdominal wall hernia, cholecystectomies for acute cholecystitis, small surgeries and proctological emergencies recorded drops of 70%, 39%, 33% and 47% respectively. The strongest reduction in frequencies of emergency surgeries was reported from the designated COVID center in the examined region. CONCLUSIONS: Emergency general surgery is an essential service that continues to run under all circumstances. Our data show that COVID-19-related restrictions have resulted in a significant decrease in the utilization of acute surgical care.

Expression of the microRNA-200 Family, microRNA-205, and Markers of Epithelial-Mesenchymal Transition as Predictors for Endoscopic Submucosal Dissection over Esophagectomy in Esophageal Adenocarcinoma: A Single-Center Experience.

Endoscopic submucosal dissection (ESD) is an effective treatment of early esophageal adenocarcinomas (EACs). The decision of ESD over esophagectomy is based on clinical evaluation of tumor depth and invasion. On a molecular level, tumor invasion is strongly associated with epithelial-to-mesenchymal transition (EMT). Here, we investigated whether localized ESD-resected and surgically resected EAC samples displayed different expression profiles of EMT protein and microRNA markers and whether these different expression profiles were able to retrospectively discriminate localized and surgically resected samples. By doing this, we aimed to evaluate whether preoperative measurement of EMT marker expression might support the decision regarding ESD over surgery. The results showed that ESD-resected samples displayed an epithelial expression profile, i.e., high expression of epithelial protein markers, whereas surgically resected samples displayed high expression of mesenchymal markers. In addition, the anti-EMT microRNA-205 was significantly more expressed in ESD-resected samples, whereas we found no significant differences in the expression levels of microRNA-200 family members. Furthermore, in our retrospective approach, we have demonstrated that measurement of selected EMT markers and microRNA-205 has significant discrimination power to distinguish ESD-resected and surgically resected samples. We suggest that the assessment of EMT status of EAC samples on a molecular level may support clinical evaluation regarding the applicability of ESD.

Role of p-Benzoquinone in the Synthesis of a Conducting Polymer, Polyaniline.

Polyaniline (PANI) and 2,5-dianilino-p-benzoquinone both are formed by oxidation of aniline in an acidic aqueous environment. The aim of this study is to understand the impact of addition of p-benzoquinone on the structure of PANI prepared by the oxidation of aniline hydrochloride with ammonium peroxydisulfate and to elucidate the formation of low-molecular-weight byproducts. An increasing yield and size-exclusion chromatography, Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy, and nuclear magnetic resonance analyses of the products show that p-benzoquinone does not act as a terminating agent in the synthesis of PANI and the content of 2,5-dianilino-p-benzoquinone increases with the increasing molar concentration of p-benzoquinone in the reaction mixture, [BzQ]. Regarding the structure of PANI, Raman and UV-visible spectra show that the doping level and the charge delocalization both decrease with the increase of [BzQ], and the FTIR spectra of the PANI bases indicate an increased concentration of benzenoid units at higher [BzQ]. We explain these observations by an increasing concentration of structural defects in PANI chains and propose a 2,5-dianilino-p-benzoquinone-like structure of these defects present as pendant groups. The bands typical of 2,5-dianilino-p-benzoquinone-like moiety are observed even in the vibrational spectra of the sample prepared without addition of p-benzoquinone. This confirms in situ oxidation of aniline to p-benzoquinone within the course of the oxidation of aniline hydrochloride to PANI.

Perioperative chemotherapy versus neoadjuvant chemoradiation for patients with adenocarcinoma of the distal esophagus in Austria: a retrospective analysis.

BACKGROUND: The aim of this study was to compare the outcome of patients with adenocarcinoma of the distal esophagus (AEG type I) treated with neoadjuvant chemoradiation or perioperative chemotherapy. METHODS: Eligible patients from four Austrian centers were selected to conduct a retrospective analysis. All patients treated between January 2007 and October 2017 with chemotherapy according to EOX-protocol (Epirubicin, Oxaliplatin, Xeloda) or chemoradiation according to CROSS-protocol (carboplatin/paclitaxel + RTX 41.4 Gy), before esophagectomy were included. Primary outcomes disease-free survival (DFS) and overall survival (OS) as well as secondary outcomes downstaging of T- or N-stage and achievement of pathological complete response pCR (ypT0N0M0) were analyzed. Data of 119 patients were included. RESULTS: Complete data was available in 104 patients, 53 patients in the chemoradiation group and 51 patients in the chemotherapy group. The mean number of lymph nodes removed was significantly higher in the EOX group (EOX 29 ± 15.5 vs. CROSS 22 ± 8.8; p < 0.05). Median follow-up in the CROSS group was 17 months (CI 95% 8.8-25.2) and in the EOX group 37 months (CI 95% 26.5-47.5). In the chemotherapy group, the OS rate after half a year, - 1, and 3 years was 92%, 75%, and 51%. After chemoradiation, overall survival after half a year was 85 %, after 1 year 66%, and after 3 years 17%. In the EOX group DFS after ½, - 1, and 3 years was 90%, 73%, and 45%, in the chemoradiation group after half a year 81%, after 1 year 55% and after 3 years 15%. Pathological complete response (pCR) was achieved in 23% of patients after CROSS and in 10% after EOX (p < 0.000). CONCLUSIONS: There seem to be clear advantages for chemoradiation, concerning the major response of the primary tumor, whereas a tendency in favor for chemotherapy is seen in regards to systemic tumor control. Furthermore, the type of neoadjuvant treatment has a significant influence on the number of lymph nodes resected.

Concomitant 1p36 deletion and TNFRSF14 mutations in primary cutaneous follicle center lymphoma frequently expressing high levels of EZH2 protein.

Primary cutaneous follicle center lymphoma (PCFCL) is an indolent variant of follicular lymphoma (FL) with limited information available on the genetic background of the disease. The genetic hallmark of nodal FL, the t(14;18) translocation, affecting the BCL2 gene, is rare in PCFCL. Loss of 1p36, the most common secondary chromosomal abnormality in nodal FL, has been recently reported in 16.7% of PCFCL cases. In order to further characterize PCFCL, 21 cases were analyzed using interphase fluorescence in situ hybridization with BCL2 break apart and 1p36/1q25 dual color probes. Sanger sequencing was used to investigate TNFRSF14 and EZH2 mutations and immunohistochemistry to assess BCL2, EZH2 protein expressions.1p36 deletion occurred in 22% (5/21), BCL2 gene break in 10% (2/20) of the PCFCL cases. Mutations of the candidate tumor suppressor gene of the 1p36 region, TNFRSF14 mutations were detected in 4/17 (23.5%) cases with 2 cases presenting with concurrent 1p36 deletion. EZH2 hotspot mutations at Y641, A682, and A692 were not found. High EZH2 protein expression associated with a BCL2 negative phenotype was observed in 43% (9/21) of the cases. BCL2 gene break or 1p36 deletion did not impact the prognosis; however, they showed association with advanced stages at diagnosis (p = 0.016) and a tendency with shorter event free survival (p = 0.052).In conclusion, 1p36 deletion co-occurs with acquired TNFRSF14 mutations, suggesting a role of this tumor suppressor gene in the development of a subgroup of PCFCL. High EZH2 protein expression associated with BCL2 negative phenotype is common and might represent an ideal therapeutic target.

Application of gentamicin-collagen sponge shortened wound healing time after minor amputations in diabetic patients - a prospective, randomised trial.

INTRODUCTION: Diabetic foot infections are frequently polymicrobial. The lower tissue concentration of systemically administered antibiotics in diabetic patients was reported. Collatamp(®)EG (Syntacoll GmbH Saal/Donau, Germany) is a bioabsorbable, gentamicin impregnated collagen spongeused for local treatment. The aim of this randomized trial was to assess influence of gentamicin-collagen sponge applied to a wound on surgical outcomes after minor amputations in diabetic patients. MATERIAL AND METHODS: Fifty diabetic patients indicated for minor amputation in 2009 at our surgery department were included in the study. Patients were pre-operatively randomised into two groups. Twenty-five patients in group A were treated with gentamicin impregnated collagen sponge applied into wound peri-operatively while 25 patients in group B had minor amputation without gentamicin sponge. RESULTS: There was no significant difference in the demographic data, procedures performed, diabetes duration and peripheral vascular disease severity between the groups. The median glycosylated haemoglobin was 6.0% (range: 4.6-9.5%) in group A and 6.2% (range: 4.0-8.4%) in control group B (non-significant). Median TcPO2 level was 44 (range: 13-67) in group A and 48 (range: 11-69) in control group B (non-significant). The median of wound healing duration in group A was 3.0 weeks (range: 1.7-17.1 weeks) compared to 4.9 weeks (range: 2.6-20.0 weeks) in control group B. This was with a statistically significant difference (p < 0.05). CONCLUSIONS: Application of gentamicin impregnated collagen sponge shortened wound healing duration after minor amputations in diabetic patients by almost 2 weeks.

Immunosuppressive protocol with delayed use of low-dose tacrolimus after aortic transplantation suppresses donor-specific anti-MHC class I and class II antibody production in rats.

BACKGROUND: Arterial allografts are used as vascular conduits in the treatment of prosthetic graft infection. Immunosuppression decreases their rupture risk rate. However, immunosuppression can be unprofitable in florid infection. Previously, we confirmed inhibition of cell-mediated destruction of rat aortic grafts by delayed use of tacrolimus. In this work, we studied the influence of this protocol on the antibody-mediated rejection. MATERIAL AND METHODS: Flow cytometry was used for the retrospective analysis of day 0, 14, and 30 sera obtained from Lewis rat recipients of isogeneic fresh infrarenal aortic grafts (group A) or Brown-Norway rat aortic grafts (group B,C,D) for the presence of donor-specific anti-MHC class I and II antibodies. Tacrolimus in daily dose of 0.2 mg/kg was administered from day 1 to day 30 (group C) or from day 7 to day 30 (group D). RESULTS: Inhibition of fluorescence-labeled anti-BN MHC class I and MHC class II antibodies binding to BN-splenocytes was observed only by day 14 and day 30 sera of allogeneic non-immunosuppressed Lewis rats (group B). The day 30 sera significantly decreased anti-MHC I (42±3%) and anti-MHC II antibody binding (56±3%) compared to day 0 (76±9%, p=0.005 and 79±5%, p=0.003, respectively). Deposition of immunoglobulins G into the tunica media was observed only in non-immunosuppressed aortic allografts on day 30. CONCLUSIONS: Fresh aortic allografts induce donor-specific anti-MHC class I and anti-MHC class II antibody production. Delayed administration of tacrolimus completely suppressed antibody production and antibody-mediated destruction of aortic allografts.

Antibody-mediated rejection of arterialised venous allografts is inhibited by immunosuppression in rats.

OBJECTIVES AND DESIGN: We determined in a rat model (1) the presence and dynamics of alloantibodies recognizing MHC complexes on quiescent Brown-Norway (BN) splenic cells in the sera of Lewis (LEW) recipients of Brown-Norway iliolumbar vein grafts under tacrolimus immunosuppression; and (2) the presence of immunoglobulins in the wall of acute rejected vein allografts. MATERIALS AND METHODS: Flow cytometry was used for the analysis of day 0, 14 and 30 sera obtained from Lewis recipients of isogeneic iliolumbar vein grafts (group A) or Brown-Norway grafts (group B, C) for the presence of donor specific anti-MHC class I and II antibodies. Tacrolimus 0.2 mg/kg daily was administered from day 1 to day 30 (group C). Histology was performed on day 30. RESULTS: Sera obtained preoperatively and on day 30 were compared in all groups. The statistically significant decrease of anti MHC class I and II antibody binding was observed only in allogenic non-immunosuppressed group B (splenocytes: MHC class I - day 0 (93% ± 7% ) vs day 30 (66% ± 7%), p = 0.02, MHC class II - day 0 (105% ± 3% ) vs day 30 (83% ± 5%), p = 0.003; B-cells: MHC class I - day 0 (83% ± 5%) vs day 30 (55% ± 6%), p = 0.003, MHC class II - day 0 (101% ± 1%) vs day 30 (79% ± 6%), p = 0.006; T-cells: MHC class I - day 0 (71% ± 7%) vs day 30 (49% ± 5%), p = 0.04). No free clusters of immunoglobulin G deposition were detected in any experimental group. CONCLUSION: Arterialized venous allografts induce strong donor-specific anti-MHC class I and anti-MHC class II antibody production with subsequent immune-mediated destruction of these allografts with no evidence of immunoglobulin G deposition. Low-dose tacrolimus suppress the donor-specific antibody production.

Role of serum levels of angiogenic cytokines in assessment of angiogenesis after stem cell therapy of diabetic patients with critical limb ischemia.

The release of proangiogenic cytokines into the circulation after stem cell (SC) therapy and compensatory increase of angiogenesis inhibitors may reflect local vasculogenesis but also can increase the risk of side effects. The aim of our study was to evaluate serum levels of angiogenic cytokines with regard to the assessment of local and systemic vasculogenesis in diabetic patients with no-option critical limb ischemia (NO-CLI). Twenty-five diabetic patients with NO-CLI treated with SCs isolated from bone marrow or stimulated peripheral blood were included in the study. Serum levels of proangiogenic cytokines (VEGF, bFGF, Ang-1, PDGF-AA, and PDGF-BB) and an antiangiogenic cytokine (endostatin) were assessed 6 months after cell treatment, compared to baseline values, and correlated with the number of injected CD34(+) cells. The clinical effect of SC therapy (assessed by changes in TcPO2) and potential systemic vasculogenesis (assessed by eye fundus examination) were evaluated after 6 months. Serum levels of angiogenic inhibitor endostatin increased significantly after 1 and 3 months (p = 0.0003), but no significant increase in serum levels of proangiogenic cytokines was observed. A significant correlation between number of injected CD34(+) cells and serum levels of endostatin was observed (r = 0.41, p < 0.05); however, proangiogenic cytokines did not correlate with CD34(+) cells. No correlation between increase in TcPO2 after treatment and serum levels of any of the angiogenic cytokines were seen, and no signs of systemic vasculogenesis in the retina were observed after 6 months. Despite the significant increase in the levels of the angiogenic inhibitor endostatin following SC treatment, there was no risk of systemic vasculogenesis after SC therapy as documented by serum levels of proangiogenic cytokines or changes in the retina.

Polypropylene mesh repair of incisional hernia after kidney transplantation: single-center experience and review of the literature.

BACKGROUND: Incisional hernia after kidney transplantation increases patient morbidity and impacts quality of life. Reports of hernia mesh repair after kidney transplantation are rare; thus, the benefit of mesh hernioplasty in transplanted patients is assumed. However, it is also assumed that transplant patients are susceptible to incisional and mesh infections. MATERIAL/METHODS: Between January 1, 2005 and December 31, 2010, we performed 1067 kidney transplantations. Twenty-eight patients developed incisional hernias (2.6%), and mesh repair was performed in 20 of them (8 women, 12 men; median age 59.5 years, range 43 to 68 years). We retrospectively studied this latter group. We also reviewed the literature regarding the results of this treatment. RESULTS: Postoperative mortality was zero, but postoperative wound bleeding led to surgical revision in 1 patient. Wound infection did not occur. During the follow-up period we observed 4 hernia recurrences (20%). CONCLUSIONS: In conclusion, our retrospective study and review of the literature confirmed the safety and low incidence (1.1% to 3.8%) of mesh hernia repair in chronic immunosuppressed patients after renal transplantation, which has a minimal risk of wound infection and no higher risk of hernia recurrence than in non-transplant patients.