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Let R be a non-commutative prime ring of characteristic different from 2, with center Z(R) and extrended centroid C and let F be a non-zero generalized derivation of R. Denote by f(R) = {f(r1, . . ., rn) : r1, . . ., rn ∈ R}, the set of all the evaluations of a non-central polynomial f(x1, . . ., xn) over C. If F acts as a Lie homomorphism on f(R) then F is the identity map. [ABSTRACT FROM AUTHOR]

Let R be a prime ring of characteristic different from 2, with extended centroid C, U its two-sided Utumi quotient ring, F a nonzero generalized derivation of R, f(x1,..., xn) a noncentral multilinear polynomial over C inn noncommuting variables, and a, b ∈ R such that a[F(f(r1,..., rn)), f(r1,...,rn)]b = 0 for any r1..., rn ∈ R. Then one of the following holds: (1) a = 0; (2) b = 0; (3) there exists λ ∈ C such that F(x) = λx, for all x ∈ R; (4) there exist q ∈ U and λ ∈ C such that F(x) = (q + λ)x + xq, for all x ∈ R, and f(xl,..., xn)² is central valued on R; (5) there exist q ∈ U and λ, μ ∈ C such that F(x) = (q + λ)x + xq, for all x ∈ R, and aq = μa, qb = μb. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: The aim of this work is to characterize the shape and the volume of the internal anal sphincter (IAS) in normal subjects by three-dimensional anorectal ultrasonography. Methods: Thirty-nine normal volunteer males (mean age 58.5±18.7) and 25 females (mean age 59.4±14.1) were submitted to anorectal ultrasonography. The tissue is defined by a semiautomatic procedure. Measurements of thickness, length and volume were assessed automatically. The software provides an average number of 57,600 thickness measurements, 360 length measurements for each zone (90 for each quadrant) and seven volume measurements (one for each anatomical area).The mean values of magnitudes were calculated for the entire volume in each quadrant and zone. Age and gender-related variations were analyzed. Results: In assessments of the whole tissue, only thickness was gender-related, with greater thickness for females (male thickness: 1.81±0.47mm, female thickness 2.16±0.57mm, P-value<0.01).In the distal zone: thickness, length and volume were all larger in females (for male and female respectively: 1.83±0.49mm vs 2.34±0.58mm, P-value<0.01, for the thickness; 10.87±2.10mm vs 12.18±2.21mm, P-value<0.02 for the length and 1501±605mm3 vs 2169±871mm3, P-value<0.01 for the volume). In the medial zone, only thickness was gender-related, with greater thickness in females (male thickness: 2.04±0.60mm, female thickness:2.44±0.74mm, P-value<0.02).The only variation observed in the proximal zone concerned length, larger in males (respectively: 11.27±2.84mm vs 9.55±2.43mm, P-value<0.02). The male population was significantly positively correlated with ageing for volume in the whole tissue (ρ =0.32, P-value<0.05), and for both thickness and volume in the medial zone (ρ =0.33, P-value<0.05 for thickness; ρ =0.39, P-value<0.02 for the volume). Conclusion: This new method is useful to understand both functional anal disorders and local damage which may affect only part of the muscle tissue. [Copyright &y& Elsevier]

Background: Recently, in the field of abdominal wall repair surgery, some minimally invasive procedures introduced the use of staplers to provide a retromuscular prosthetic repair. However, to the knowledge of the authors, there are little data in the literature about the outcomes of stapled sutures adoption for midline reconstruction. This study aims to investigate the biomechanics of stapled sutures, simple (stapled), or oversewn (hybrid), in comparison with handsewn suture. From the results obtained, we tried to draw indications for their use in a clinical context., Methods: Human cadaver fascia lata specimens, sutured (handsewn, stapled, or hybrid) or not, underwent tensile tests. The data on strength (maximal stress), ultimate strain (deformability), Young's modulus (rigidity), and dissipated specific energy (ability to absorb mechanical energy up to the breaking point) were recorded for each type of specimens and analyzed., Results: Stapled and hybrid suture showed a significantly higher strength (handsewn 0.83 MPa, stapled 2.10 MPa, hybrid 2.68 MPa) and a trend toward a lower ultimate strain as compared to manual sutures (handsewn 344%, stapled 249%, hybrid 280%). Stapled and hybrid sutures had fourfold higher Young's modulus as compared to handsewn sutures (handsewn 1.779 MPa, stapled 7.374 MPa, hybrid 6.964 MPa). Handsewn and hybrid sutures showed significantly higher dissipated specific energy (handsewn 0.99 mJ-mm 3 , stapled 0.73 mJ-mm 3 , hybrid 1.35 mJ-mm 3 )., Conclusion: Stapled sutures can resist high loads, but are less deformable and rigid than handsewn suture. This suggests a safer employment in case of small defects or diastasis (< W1 in accord to EHS classification), where the presumed tissutal displacement is minimal. Oversewing a stapled suture improves its efficiency, becoming crucial in case of larger defects (> W1 in accord to EHS classification) where the expected tissutal displacement is maximal. Hybrid sutures seem to be a good compromise., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Laparoscopic Incisional and Ventral Hernia Repair (LIVHR) is a safe and worldwide accepted procedure performed using absorbable tacks. The aim of the study was to evaluate recurrence rate in a long term follow-up and whether the results of laparoscopic IVH repair in the elderly (≥65 years old) are different with respect to results obtained in younger patients., Methods: One hundred and twenty-nine consecutive patients (74 women and 55 men, median age 67 years, range = 30-87 years) with ventral (N = 42, 32.5%) or post incisional (N = 87, 67.5%) hernia were enrolled in the study. Patients were divided into two groups according to their age: group A (N = 55, 42.6%) aged <65 years and group B (N = 74, 57.4%) aged ≥65 years., Results: The mean operative time was not significantly different between groups (66.7 ± 37 vs. 74 ± 48.4 min, p = 0.4). To the end of 2016, seven recurrences had occurred (group A = 3, group B = 4, p = 1). Complications occurred in 8 (16%) patients in group A and 21 (28.3%) patients in group B., Conclusion: In conclusion, our results confirm that the use of absorbable tacks does not increase recurrence frequency and laparoscopic incisional and ventral repair is a safety procedure also in elderly patients., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Cystic adventitial disease (CAD) is a rare vascular disease that causes a localized stenosis or occlusion in absence of alterations of blood vessels in other sites of the body. CAD is predominantly located to the popliteal artery, although cases have been described involving other arteries. Typically it affects young men with minimal cardiovascular risk factors, presenting a short history of progressive claudication. Imaging is based on US, CTA and MRA. Suspected diagnosis is confirmed at the time of the surgery. We report two cases of CAD involving the popliteal artery. In the first case a 59 year-old man was treated by resection of the popliteal artery and a reversed saphenous vein was used to restore circulation. In the second case a 53 year-old man was treated by resection of the popliteal artery and a cryo-preserved arterial graft was used to restore circulation. We also made a review of the literature on this subject.

The coexistence of colorectal cancer and abdominal aortic aneurysm has been observed with increasing frequency, raising several questions about therapeutic and surgical strategies for management of both diseases. This study has reviewed 440 cases (359 cases analyzed) of colorectal cancer associated with abdominal aortic aneurysm recovered in the literature from year 1987 to 2010. In 120 cases, patients were treated in one stage; in 239 cases, they were treated in two stages. The treatment in two stages was associated with a morbidity of 26.4%, with a mortality of 5% and prosthetic infection of 0.8%. The treatment in one stage had rates of complications and mortality of 13.3% and 4.2% respectively and no cases of prosthetic infection. Analysis of the literature shows that the treatment in two stages exposes patients to a higher risk of complications and prosthetic infection.

Background: Colorectal cancer (CRC) is one of the most frequent causes of cancer related deaths worldwide. Recently, the use of cell-free DNA as diagnostic tools to identify cancer has been investigated. The aim of this work was to assess whether circulating DNA could be considered a useful marker for detection of early stage CRC and polyps., Methods: A total of 118 patients with CRC were included in the study along with 49 patients with colorectal polyps and 26 control subjects. Cell-free DNA was quantified using a real-time TaqMan-polymerase chain reaction assay. Non-parametric tests (Mann-Whitney test and Spearman correlation) were utilized for statistical analysis., Results: Serum DNA concentrations were significantly higher in CRC patients and patients with polyps (median value 105.0 ng/mL and 40.0 ng/mL) compared with controls (median value 14.0 ng/mL; p<0.05). Although carcinoembryonic antigen was above the cut-off in only 13/66 (19.7%) patients with early stage CRC, serum free DNA showed values above the threshold identified using receiver operator characteristic (ROC) curve analysis in 53/66 (80.3%) patients., Conclusions: Our data confirm that serum DNA concentrations are significantly increased in CRC patients with early stage disease and in patients with polyps. This marker might be useful for identifying high-risk individuals.