Tissue Strips Research Articles

Achilles tendon injury repair and sports performance

Various Achilles tendon problems and injuries, ruptures in particular, are challenging and harmful to an athletes general performance or to their game. The Achilles tendon is the strongest and thickest tendon in the human body; a strip of this connective tissue connecting the leg muscles to the heel is responsible for several essential functions involving running, jumping, or even standing. Considering the complexity and speed of the movement, athletes are more prone to occurrences of such damage, which usually has serious consequences, including the end of the career. The recovery methods after an Achilles tendon injury, either based on surgical or physical operations, are long and arduous but overall result in full recovery. Although surgical remedies provide a faster way to return to normal activity, they have some drawbacks, such as wound-healing issues. In contrast, the non-surgical methods, as less invasive, introduce a larger risk of re-rupture. After the injury, an athlete tends to reduce their performance. This manifests through a decrease in games played, efficiency, and return to performance for high dynamics sports, such as basketball or football. Meanwhile, for baseball, where the physical load on the Achilles tendon is different, such injuries do not affect as much the results. This fact reflects the importance of therapists to elaborate on methods of full functional return after surgery to bring the player back to identity.

Comparison between early and late weight bearing after anterior cruciate ligament reconstruction surgery.

The anterior cruciate ligament (ACL) is a strip of dense connective tissue that runs from the femur to the tibia with a relatively poor blood supply. It prevents the femoral condyles from rolling posteriorly. ACL is commonly injured in any knee trauma, ranging from a little sprain to a total rupture. The arthroscope is the gold standard approach for identifying ACL tears, which may be treated conservatively or surgically. To assess the efficiency of immediate and delayed weight bearing after arthroscopic ACL reconstruction. Cohort longitudinal study carried through 6years from 2017 to 2023 et al.-kindy Teaching, Ulamaa, and Almuktar hospitals 186 patients, the patients were divided randomly into 2 groups, group A (n = 93) with immediate (after 10days) weight bearing and group B (n = 93) with delayed (after 1month) weight bearing following ACL reconstruction. any patients with chondral lesions, aged less than 19 or more than 40years, knee osteoarthritis, ligament damage, and deformity in lower extremities were excluded. Patients from both groups A and B had complete ACL tears and underwent arthroscopic ACL reconstruction follow-up for 6months duration regarding stiffness, infection, giving up pain, swelling, and quadriceps muscle atrophy. In group A, there were 93 patients,70 male and 23 female, and meniscal injury was 89 patients. While in group B (93 patients) 57 male and 36 female, meniscal injury in group B was 91. There is a statistically significant difference regarding knee swelling. (80.6% in group A, and 10.8% in group B), and knee pain in which (79.6% in group A patients and only 7.5% in group B). There is no significant value between the two groups about the knee getting given up, infection, stiffness, and quadriceps muscle atrophy. Delay weight bearing after ACL reconstruction makes the patients less prone to knee pain and effusion but more prone to quadriceps muscle atrophy.

A novel technique for atraumatic transurethral catheterisation of male rats.

Transurethral catheterisation of male rats is technically difficult owing to anatomical peculiarities. In the male rat, the urethral striated sphincter consists of two lateral fascicles separated by an anterior and a posterior strip of connective tissue, which impedes the smooth insertion of a urinary catheter. For rat studies requiring continuous collection of urine, bladder irrigation, or measurement of bladder pressure, investigators either have to exclude the male population (be limited to the female population) or perform percutaneous (suprapubic) bladder puncture in male rats, which is more traumatic and invasive than transurethral catheterisation. This paper describes a novel, atraumatic method of transurethral catheterisation in the male rat, with the aid of a microscope and microsurgical instruments. Six Wistar rats were used for this experiment, all of which were catheterised successfully, with no evidence of bladder or urethral injury. The study shows that male rats can be safely catheterised via the urethra with the aid of a microscope and microsurgical instruments for both visual and tactile feedback. This is a relatively straightforward technique to learn and can allow for inclusion of male rats in future studies requiring urinary analysis or bladder irrigation, without the need for traumatic percutaneous (suprapubic) bladder puncture.

Morphological Changes in Tissue When Using Polypropylene Implants with Adsorbed Multipotent Stromal Cells in Experiment.

The subcutaneous tissue of rats after implantation of polypropylene materials with adsorbed bone marrow-derived mesenchymal multipotent stromal cells (MMSCs) was studied using light microscopy. Inflammation in response to implantation was mild, and the foreign material was encapsulated into a thin strip of dense fibrous connective tissue with multinucleated macrophages. By 1 year after introduction of the monofilament and 6 and 12 months after implantation of the mesh product, some threads were deformed, broken, and had sharp edges. Small fragments of foreign material appeared in the adjacent tissues surrounded by their own relatively thick acellular capsule. As a result of preliminary adsorption of MMSCs on polypropylene, the thickness of the connective tissue capsule decreased, its vascularization increased, and the severity of inflammatory infiltration decreased. However, all effects of MMSCs adsorption in rats were transient and disappeared within 1 week.

343. DIAGNOSTIC VALUE OF ENDOBRONCHIAL ULTRASOUND-GUIDED TRANSESOPHAGEAL NEEDLE ASPIRATION (EBUS-TENA) IN LESIONS ADJACENT TO BOTH THE TRACHEA/BRONCHUS AND ESOPHAGUS

Abstract Objective To investigate the clinical diagnostic value of endobronchial ultrasound-guided transesophageal needle aspiration (EBUS-TENA) in lesions adjacent to both the trachea/bronchus and esophagus Methods The clinical data of 12 patients who underwent EBUS-TENA from February 2019 to February 2022 were collected. The operative physicians and nurses worked closely with each other and meticulously cared the patients. The vital signs changes were observed and recorded, as well as intraoperative adverse events and the acquired specimens. Results All the 12 patients underwent surgery successfully, and hair-like tissue strips were obtained in each case. There were 8 cases of central lung cancer and 4 cases of mediastinal tumor. The preoperative vital signs scores showed no significant difference with the intraoperative and postoperative scores (P>0.05). A few complications occurred, including 2 case of mild cough, 2 case of nausea and vomiting, with no symptoms of severe cough and dyspnea, haemorrhage, mediastinal infection, pneumothorax, mediastinal emphysema and other complications. Conclusion EBUS-TENA has significant effect in successfully obtaining pathological tissue specimens especially for lesions adjacent to both the trachea/bronchus and esophagus, improving disease positive diagnosis rate, reducing patients discomfort and the risk of surgery.

The effect of structural bending properties versus material bending properties on maize stalk lodging

Stalk lodging (mechanical failure of stalks or stems before harvest) is a major problem in grain production that significantly reduces yield. Efforts to improve stalk lodging are hampered by a limited understanding of the determinants of stalk failure. This study examined the structural bending properties and material bending properties of maize (Zea mays L.) stalks. First, an in-field phenotyping device known as DARLING (Device for Assessing Resistance to Lodging In Grains) was used to determine structural properties of maize stalks. Stalks were then subjected to a rind penetration protocol and morphological measurements were acquired. Finally, small strips of rind tissue were excised from the stalks and micro three-point bending tests were conducted to determine the material properties of the rind tissue. Results showed that the material bending strength of the rind tissue was approximately twice as large as the bending stresses present in the rind tissue when failure occurred during field testing. This indicates that stalks ultimately fail due to some form of buckling (i.e., structural failure) as opposed to material failure. This result is relevant to genetic and breeding studies seeking to address the problem of stalk lodging. In particular, these results suggest that improvements in stalk lodging resistance should focus on the stalk's geometric features, such as the ratio of rind thickness to diameter, rather than solely on enhancing material strength. For the samples in this study, material strength ranged between 64 and 197 MPa whereas material stiffness ranged between 4 and 12 GPa. Rind penetration resistance was found to be a good predictor of material properties but a poor predictor of structural properties.

Exploring contrast-enhancing staining agents for studying adipose tissue through contrast-enhanced computed tomography

Contrast-enhanced computed tomography offers a nondestructive approach to studying adipose tissue in 3D. Several contrast-enhancing staining agents (CESAs) have been explored, whereof osmium tetroxide (OsO4) is the most popular nowadays. However, due to the toxicity and volatility of the conventional OsO4, alternative CESAs with similar staining properties were desired. Hf-WD 1:2 POM and Hexabrix have proven effective for structural analysis of adipocytes using contrast-enhanced computed tomography but fail to provide chemical information. This study introduces isotonic Lugol’s iodine (IL) as an alternative CESA for adipose tissue analysis, comparing its staining potential with Hf-WD 1:2 POM and Hexabrix in murine caudal vertebrae and bovine muscle tissue strips. Single and sequential staining protocols were compared to assess the maximization of information extraction from each sample. The study investigated interactions, distribution, and reactivity of iodine species towards biomolecules using simplified model systems and assesses the potential of the CESA to provide chemical information. (Bio)chemical analyses on whole tissues revealed that differences in adipocyte gray values post-IL staining were associated with chemical distinctions between bovine muscle tissue and murine caudal vertebrae. More specific, a difference in the degree of unsaturation of fatty acids was identified as a likely contributor, though not the sole determinant of gray value differences. This research sheds light on the potential of IL as a CESA, offering both structural and chemical insights into adipose tissue composition.

Insights into the role of PGF2α in canine periparturient myometrium.

Parturition in dogs is subjected to complex hormonal regulation, with the involvement of prostaglandin F2α (PGF2α) still not fully understood. To investigate uterine inertia (UI), the most prevalent maternal reason for dystocia in the bitch, a better understanding of undisturbed uterine, especially myometrial function, is crucial. Our aim was to gain deeper insights into the role of PGF2α in the canine parturient myometrium. Uterine biopsies were obtained during medically indicated cesarean sections. To test for stimulatory effects of PGF2α in vitro, circular and longitudinal myometrial layer tissue strips were challenged with 50pM, 0.5µM, and 50µM PGF2α. Prostaglandin-endoperoxide synthase 2 (PTGS2) and PGF2α-receptor (PTGFR) mRNA expressions were compared between primary UI (PUI) and obstructive dystocia (OD) samples in isolated parturient myometrium. PTGFR protein expression was assessed in full thickness uterine samples. PGF2α concentrations were analyzed in canine interplacental tissue around term. In the organ bath, the contractile response to PGF2α was limited to the circular layer at the highest dosage. Correspondingly, PTGFR immunohistochemical staining was significantly stronger in the circular layer (p ≤ 0.01). PTGS2 gene expression did not differ between PUI and OD, whereas PTGFR gene expression could not be quantified. Local uterine PGF2α concentrations correlated negatively with serum P4 levels and were the highest during prepartum luteolysis while being significantly lower in PUI. Conclusively, despite the significant increase in local PGF2α concentrations at birth, confirming the interplacental tissue as a production site, our results suggest that PGF2α might affect uterine contractility during labor, mainly indirectly.

In vitro effects of β3-adrenoceptor agonist mirabegron on the human ureter.

This study aimed to investigate the effect of mirabegron, a β3-adrenoceptor agonist with widespread clinical use for treating overactive bladder disease, on isolated healthy human ureter strips. This was a prospective study employing a series of in vitro organ bath experiments using ureteral tissues of kidney grafts from 10 healthy donors. The ureteral strips were subjected to cumulative mirabegron concentrations (10-9-10-4.5 M). Effects on frequency or amplitude of spontaneous, 10 mM KCl- or EFS-induced contractions were evaluated. Mirabegron decreased the frequency of spontaneous ureteric contraction in a concentration-dependent manner. Statistically significant decrease in the frequency of spontaneous contraction was observed at 10-8-10-4.5 M. In 10 mM KCl medium, statistically significant change in frequency was observed at 10-9-10-4.5 M. Statistically significant decrease in the amplitudes of spontaneous contraction was observed at 10-7-10-4.5 M. In a 10 mM KCl medium, statistically significant change in amplitudes was observed at 10-8-10-4.5 M. Mirabegron reduced the amplitude and frequency of human ureter activity in in vitro organ bath studies. This effect was achieved in a dose-dependent manner on isolated tissue strips. Although monotherapy with mirabegron remains uncertain, this study has the potential to elucidate the mechanism underlying the effectiveness of mirabegron, particularly in combination therapy for ureteral stones.

Unpredictable chronic mild stress shows neuronal remodeling in multipolar projection neurons of hippocampal complex in postnatal chicks.

The hippocampal complex of birds is a narrow-curved strip of tissue that plays a crucial role in learning, memory, spatial navigation, and emotional and sexual behavior. This study was conducted to evaluate the effect of unpredictable chronic mild stress in multipolar neurons of 3-, 5-, 7-, and 9-week-old chick's hippocampal complex. This study revealed that chronic stress results in neuronal remodeling by causing alterations in dendritic field, axonal length, secondary branching, corrected spine number, and dendritic branching at 25, 50, 75, and 100µm. Due to stress, the overall dendritic length was significantly retracted in 3-week-old chick, whereas no significant difference was observed in 5- and 7-week-old chick, but again it was significantly retracted in 9-week-old chick along with the axonal length. So, this study indicates that during initial days of stress exposure, the dendritic field shows retraction, but when the stress continues up to a certain level, the neurons undergo structural modifications so that chicks adapt and survive in stressful conditions. The repeated exposure to chronic stress for longer duration leads to the neuronal structural disruption by retraction in the dendritic length as well as axonal length. Another characteristic which leads to structural alterations is the dendritic spines which significantly decreased in all age groups of stressed chicks and eventually leads to less synaptic connections, disturbance in physiology, and neurology, which affects the learning, memory, and coping ability of an individual.

In vitro inhibition of uterine contractions using electrospun nanofibers loaded with nifedipine and ML7.

To formulate a nanofiber-based controlled drug delivery system that could be effective in preventing uterine contractions and can be used for the treatment of preterm labor. We utilized uterine tissue samples obtained from ten pregnant women who underwent cesarean section at term to investigate the effect of nanofibers on spontaneous and induced myometrial contractions. We prepared nifedipine and ML7-loaded nanofibers using the electrospinning method with Poly(D,L-lactide-co-glycolide) (PLGA) polymer, resulted in seven groups of nanofibers, including a control group. Group I served as the control, Group II was non-drug loaded nanofiber, Group III was nifedipine (10-5 M) loaded nanofiber, Group IV was ML7 (3x10-5 M) loaded nanofiber, Group V was ML7 (3x10-5 M) and nifedipine (10-5 M) nanofiber, Group VI was ML7 (3x10-5 M) and nifedipine (3x10-5 M) nanofiber, and Group VII was ML7 (3x10-5 M) and nifedipine (10-4 M) nanofiber. To evaluate the contractile response, the nanofibers loaded with different doses of ML7 and nifedipine were applied onto the tissue strips, and in vitro organ bath experiments were performed. Full-thickness uterine samples were cleared of the serosa and surrounding tissues, and eight strips (3x10 mm) were prepared from each sample. The seven different nanofiber formulations were gently placed and sutured onto the strips, with one strip always kept as the time control. We recorded spontaneous, KCl-induced, and stimulated cumulative oxytocin-induced contractions from all samples in all groups. After completing all experiments, the viability of the strips was checked, and weight measurement was recorded. The administration of drug-loaded polymers resulted in a significant decrease in both the frequency and intensity of spontaneous and induced contractions in all groups (p<0.01). No significant difference was observed between the control group and the non-drug-loaded nanofiber group in post hoc analysis (p=0.704). In terms of amplitude and frequency of contractions, the most significant decrease was observed in group VII at cumulative oxytocin doses compared to the control and non-drug-loaded nanofiber groups (p<0.05). Moreover, group VI also showed a significant decrease in contraction intensity and frequency compared to the control and non-drug-loaded nanofiber groups (p<0.05). While the use of nifedipine and/or ML7-loaded nanofibers decreased both intensity and frequency of contraction, this attenuation was not significant compared to the control and empty polymer groups. However, a more significant inhibition was observed when ML7 was used with nifedipine at doses of 3x10-5 M and 10-4 M. The results indicate that human uterine contractions can be inhibited using calcium channel blocker (nifedipine) and myosin light chain kinase inhibitor (ML7) loaded nanofibers in uterine tissue strips. These results strongly suggested the potential for the development of locally effective and safe controlled drug release systems to prevent premature birth.

Adreno-Muscarinic Synergy of Contractile Responses From Human Hyperplastic Prostate.

Adreno-muscarinic synergy, a supra-additional contractile response to simultaneous application of α-adrenoreceptor and muscarinic receptor agonists, is a feature of several lower urinary tract regions that have dual sympathetic and parasympathetic innervation. We tested the hypothesis that synergy is also a feature of prostate tissue obtained from men with benign prostatic enlargement. Isolated tissue strips were dissected from prostate 'chips', collected after transurethral prostate resection procedures for in vitro experiments, to measure isometric tension at 36°C. Added separately to the superfusate, phenylephrine and carbachol generated contractions with mean pEC50 (-log10EC50) values of 5.36 and 5.58, respectively, although phenylephrine maximal responses were about six-fold greater. In the presence of carbachol, the mean phenylephrine pEC50 was significantly increased to 5.84 and maximal response increased by 28%; overall, a significant synergistic response was demonstrated. The synergistic response was reduced by muscarinic receptor antagonists, most potently by the M3-selective agent 4-DAMP (1,1-dimethyl-4-diphenylacetoxypiperidinium iodide), and less so by M2 and M1-selective inhibitors gallamine and pirenzepine, but with an overall profile indicating M3/M2 mediation of the synergistic response. The magnitude of the synergistic response was variable between prostate chips that provided isolated preparations suggesting regional heterogenicity, although their zonal origin could not be determined. These experiments show that adreno-muscarinic contractile synergy is a feature of human hyperplastic prostate tissue. This has implications for the use of a combination therapy of α-blockers and anti-muscarinic agent to relieve secondary symptoms associated with benign prostatic hyperplasia, at least in men who can tolerate antimuscarinics without a risk of retention.

Enhanced solute transport and steady mechanical stimulation in a novel dynamic perifusion bioreactor increase the efficiency of the in vitro culture of ovarian cortical tissue strips.

Introduction: We report the development and preliminary evaluation of a novel dynamic bioreactor to culture ovarian cortical tissue strips that leverages tissue response to enhanced oxygen transport and adequate mechanical stimulation. In vitro multistep ovarian tissue static culture followed by mature oocyte generation, fertilization, and embryo transfer promises to use the reserve of dormant follicles. Unfortunately, static in vitro culture of ovarian tissue does not promote development of primordial to secondary follicles or sustain follicle viability and thereby limits the number of obtainable mature oocytes. Enhancing oxygen transport to and exerting mechanical stimulation on ovarian tissue in a dynamic bioreactor may more closely mimic the physiological microenvironment and thus promote follicle activation, development, and viability. Materials and Methods: The most transport-effective dynamic bioreactor design was modified using 3D models of medium and oxygen transport to maximize strip perifusion and apply tissue fluid dynamic shear stresses and direct compressive strains to elicit tissue response. Prototypes of the final bioreactor design were manufactured with materials of varying cytocompatibility and assessed by testing the effect of leachables on sperm motility. Effectiveness of the bioreactor culture was characterized against static controls by culturing fresh bovine ovarian tissue strips for 7days at 4.8 × 10-5m/s medium filtration flux in air at -15% maximal total compressive strain and by assessing follicle development, health, and viability. Results and Conclusions: Culture in dynamic bioreactors promoted effective oxygen transport to tissues and stimulated tissues with strains and fluid dynamic shear stresses that, although non-uniform, significantly influenced tissue metabolism. Tissue strip culture in bioreactors made of cytocompatible polypropylene preserved follicle viability and promoted follicle development better than static culture, less so in bioreactors made of cytotoxic ABS-like resin.

The Diagnostic Value of Liver Biopsy for Unexplained Liver Dysfunction: A Retrospective Study.

To analyse clinical manifestations of unexplained abnormal liver function and perform hepatobiliary histopathology procedures on patients to evaluate the value of liver biopsy in diagnosing the aetiology of unexplained abnormal liver function. A convenience sampling method was used to retrospectively collect the data of patients who were diagnosed with unexplained abnormal liver function and who received liver biopsy in the Pathology Department of Tianjin Second People's Hospital, China, between March 2022 and July 2023 to analyse liver pathology and clinical manifestations. A total of 1302 patients were included in this study, which mainly included 11 diseases: autoimmune liver disease (74 cases, 5.68%), drug-induced liver injury (DILI) (204 cases, 15.67%), cancer (237 cases, 18.20%), non-alcoholic fatty liver disease (104 cases, 7.99%), non-alcoholic steatohepatitis (74 cases, 5.68%), viral hepatitis (490 cases, 37.63%), other types of hepatitis (30 cases, 2.30%), cholestatic liver disease (17 cases, 1.31%), alcoholic liver disease (15 cases, 1.15%), hepatic cyst (5 cases, 0.38%) and Gilbert syndrome (4 cases, 0.31%). The success rate of liver biopsy sampling was 100%, and (1.52 ± 0.130) tissue strips were sampled. The average operating time was 11.52 minutes. The percutaneous liver biopsy did not significantly increase short-term liver function index values (serum γ-glutamyl transpeptidase, total bilirubin, alanine transaminase, aspartate aminotransferase, alkaline phosphatase). Ninety-two patients had a small amount of liver subcapsular fluid, but there was no progress after medical treatment. Ultrasound-guided percutaneous liver biopsy has value in the diagnosis of unexplained abnormal liver function. Viral hepatitis, cancer and DILI are the most common causes of unexplained abnormal liver function. Liver biopsy does not aggravate the organic and functional impairment of the liver.

FRESH™ 3D bioprinted cardiac tissue, a bioengineered platform for in vitro pharmacology.

There is critical need for a predictive model of human cardiac physiology in drug development to assess compound effects on human tissues. In vitro two-dimensional monolayer cultures of cardiomyocytes provide biochemical and cellular readouts, and in vivo animal models provide information on systemic cardiovascular response. However, there remains a significant gap in these models due to their incomplete recapitulation of adult human cardiovascular physiology. Recent efforts in developing in vitro models from engineered heart tissues have demonstrated potential for bridging this gap using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) in three-dimensional tissue structure. Here, we advance this paradigm by implementing FRESH™ 3D bioprinting to build human cardiac tissues in a medium throughput, well-plate format with controlled tissue architecture, tailored cellular composition, and native-like physiological function, specifically in its drug response. We combined hiPSC-CMs, endothelial cells, and fibroblasts in a cellular bioink and FRESH™ 3D bioprinted this mixture in the format of a thin tissue strip stabilized on a tissue fixture. We show that cardiac tissues could be fabricated directly in a 24-well plate format were composed of dense and highly aligned hiPSC-CMs at >600 million cells/mL and, within 14 days, demonstrated reproducible calcium transients and a fast conduction velocity of ∼16 cm/s. Interrogation of these cardiac tissues with the β-adrenergic receptor agonist isoproterenol showed responses consistent with positive chronotropy and inotropy. Treatment with calcium channel blocker verapamil demonstrated responses expected of hiPSC-CM derived cardiac tissues. These results confirm that FRESH™ 3D bioprinted cardiac tissues represent an in vitro platform that provides data on human physiological response.

Management of an inadvertent late filtering bleb and hypotony in a scleral fixated intraocular lens implantation.

To report a case of inadvertent cystic filtering bleb in a patient with scleral fixated intraocular lens (SFIOL) implantation 7 years after initial procedure. A 14-year-old boy underwent lensectomy, vitrectomy and a sutured rigid SFIOL for microspherophakia in the right eye. Seven years later, the patient presented with hypotony related ocular changes. Examination revealed an inadvertent cystic filtering bleb at the scleral section. Anterior segment optical coherence tomography (ASOCT) revealed gap in inner lips of the scleral wound, bridged by a thin strip of scleral tissue. A conservative management with bandage contact lens (BCL) failed after an initial improvement. Injection of trypan blue dye in the anterior chamber confirmed the presence and site of wound filtration. Surgical closure of the fistula was done and patient showed both structural and visual improvement. Meticulous wound construction and water tight closure at the end of the surgery can avoid such complications. ASOCT can be helpful in diagnosing the area of fistula. A conservative management with BCL can help by tamponading the filtering bleb. However, in unresponsive cases, surgical closure of the fistula is recommended to improve the hypotony-related changes.

Robust mixed electron-photon radiation therapy planning for soft tissue sarcoma.

Mixed electron-photon beam radiation therapy (MBRT) is an emerging technique in which external electron and photon beams are simultaneously optimized into a single treatment plan. MBRT exploits the steep dose falloff and high surface dose of electrons while maintaining target conformity by leveraging the sharp penumbra ofphotons. This study investigates the dosimetric benefits of MBRT for soft tissue sarcoma (STS)patients. A retrospective cohort of 22 STS of the lower extremity treated with conventional photon-based Volumetric Modulated Arc Therapy (VMAT) were replanned with MBRT. Both VMAT and MBRT treatments were planned on the Varian TrueBeam linac using the Millenium multi-leaf collimator. No electron applicator, cutout or additional collimating devices were used for electron beams of MBRT plans. MBRT plans were optimized to use a combination of 6 MV photons and five electron energies (6, 9, 12, 16, 20 MeV) by a robust column generation algorithm. Electron beams in this study were planned at standard 100 cm source-axis distance (SAD). The dose to the clinical target volume (CTV), bone, normal tissue strip and other organs-at-risk (OARs) were compared using a Wilcoxon signed-ranktest. As part of the original VMAT treatment, tissue-equivalent bolus was required in 10 of the 22 patients. MBRT plans did not require bolus by virtue of the higher electron entrance dose. CTV coverage by the prescription dose was found to be clinically equivalent between plans of either modality: (MBRT) = 97.9 ± 0.2% versus (VMAT) = 98.1 ± 0.6% (p=0.34). Evaluating the absolute paired difference between doses to OARs in MBRT and VMAT plans, we observed lower to normal tissue in MBRT plans by 14.9 ± 3.2% ( ). Similarly, to bone was found to be decreased by 8.2 ± 4.0% ( ) of the bonevolume. For STS with subcutaneous involvement, MBRT offers statistically significant sparing of OARs without sacrificing target coverage when compared to VMAT. MBRT plans are deliverable on conventional linacs without the use of electron applicators, shortened source-to-surface distance (SSD) or bolus. This study shows that MBRT is a logistically feasible technique with clear dosimetricbenefits.

Local characterization of collagen architecture and mechanical failure properties of fibrous plaque tissue of atherosclerotic human carotid arteries.

Atherosclerotic plaque rupture in carotid arteries is a major cause of cerebrovascular events. Plaque rupture is the mechanical failure of the heterogeneous fibrous plaque tissue. Local characterization of the tissue's failure properties and the collagen architecture are of great importance to have insights in plaque rupture for clinical event prevention. Previous studies were limited to average rupture properties and global structural characterization, and did not provide the necessary local information. In this study, we assessed the local collagen architecture and failure properties of fibrous plaque tissue, by analyzing 30 tissue strips from 18 carotid plaques. Our study framework entailed second harmonic generation imaging for local collagen orientation and dispersion, and uniaxial tensile testing and digital image correlation for local tissue mechanics. The results showed that 87% of the imaged locations had collagen orientation close to the circumferential direction (0°) of the artery, and substantial dispersion locally. All regions combined, median [Q1:Q3] of the predominant angle measurements was -2° [-16°:16°]. The stretch ratio measurements clearly demonstrated a nonuniform stretch ratio distribution in the tissue under uniaxial loading. The rupture initiation regions had significantly higher stretch ratios (1.26 [1.15-1.40]) than the tissue average stretch ratio (1.11 [1.10-1.16]). No significant difference in collagen direction and dispersion was identified between the rupture regions and the rest of the tissue. The presented study forms an initial step towards gaining better insights into the characterization of local structural and mechanical fingerprints of fibrous plaque tissue in order to aid improved assessment of plaque rupture risk. STATEMENT OF SIGNIFICANCE: Plaque rupture risk assessment, critical to prevent cardiovascular events, requires knowledge on local failure properties and structure of collagenous plaque tissue. Our current knowledge is unfortunately limited to tissue's overall ultimate failure properties with scarce information on collagen architecture. In this study, local failure properties and collagen architecture of fibrous plaque tissue were obtained. We found predominant circumferential alignment of collagen fibers with substantial local dispersion. The tissue showed nonuniform stretch distribution under uniaxial tensile loading, with high stretches at rupture spots. This study highlights the significance of local mechanical and structural assessment for better insights into plaque rupture and the potential use of local stretches as risk marker for plaque rupture for patient-specific clinical applications.

Influencing Factors and Prediction Model of Performance of Needle Visualization in Fine Needle Aspiration of Thyroid Nodules

Objective To investigate the influencing factors and establish a model predicting the performance of needle visualization in fine-needle aspiration (FNA) of thyroid nodules. Methods This study prospectively included 175 patients who underwent FNA of thyroid nodules in the Department of Ultrasound in China-Japan Friendship Hospital and compared the display of the needle tips in the examination of 199 thyroid nodules before and after the application of needle visualization.We recorded the location,the positional relationship with thyroid capsule,ultrasonic characteristics,and the distribution of the soft tissue strip structure at the puncture site of the nodules with unclear needle tips display before using needle visualization.Furthermore,according to the thyroid imaging reporting and data system proposed by the American College of Radiology,we graded the risk of the nodules.Lasso-Logistic regression was employed to screen out the factors influencing the performance of needle visualization and establish a nomogram for prediction. Results The needle tips were not clearly displayed in the examination of 135 (67.8%) and 53 (26.6%) nodules before and after the application of needle visualization,respectively,which showed a significant difference (P<0.001).Based on the positional relationship between the nodule and capsule,anteroposterior/transverse diameter (A/T) ratio,blood supply,and the distribution of subcutaneous strip structure at the puncture site,a nomogram was established to predict the probability of unclear display of the needle tips after application of needle visualization.The C-index of the prediction model was 0.75 (95%CI=0.67-0.84) and the area under the receiver operating characteristic curve was 0.72.The calibration curve confirmed the appreciable reliability of the prediction model,with the C-index of 0.70 in internal validation. Conclusions Needle visualization can improve the display of the needle tip in ultrasound-guided FNA of thyroid nodules.The nomogram established based on ultrasound features such as the positional relationship between the nodule and capsule,A/T ratio,blood supply,and the distribution of subcutaneous strip structure at the puncture site can predict whether needle visualization is suitable for the examination of nodules.

The Free Superficially Based Low-Abdominal Mini Flap for Oncoplastic Breast Reconstruction.

Volume replacement in oncoplastic breast reconstruction most commonly uses pedicled flaps. In thin patients with small breasts, free-tissue transfer may be better suited to preserve breast size. Evidence on microvascular oncoplastic reconstruction is limited, and reconstruction has often required sacrifice of potential future donor sites. The free superficially based low-abdominal mini (SLAM) flap uses a narrow strip of lower abdominal tissue based on superficial perfusion of the abdominal wall that is anastomosed to chest wall perforators to preserve the ability to perform future abdominally based autologous breast reconstruction. Five patients underwent reconstruction with SLAM flaps for immediate oncoplastic reconstruction. Their mean age was 49.8 years, and their mean body mass index was 23.5. Tumor location was most commonly in the lower outer quadrant (40%). Average lumpectomy weight was 30 g. Two flaps were based on the superficial inferior epigastric artery, and three, on the superficial circumflex iliac artery. Recipient vessels included internal mammary perforators (40%), serratus branch (20%), lateral thoracic vessel branch (20%), and lateral intercostal perforators (20%). All patients underwent radiation therapy without delay and maintained volume, symmetry, and contour at an average period of 11.7 months after surgery. There were no cases of flap loss, fat necrosis, or delayed wound healing. The free SLAM flap allows for immediate oncoplastic breast reconstruction in thin, small-breasted patients with limited regional tissue without sacrificing future potential donor sites for autologous breast reconstruction. Therapeutic, IV.