Median Stiffness Research Articles

Enhancement of a one-step membrane technique for the treatment of large bone defects by pre-seeding the membrane with CD8 lymphocyte depleted bone marrow mononuclear cells in a rat femoral defect model.

The one-step membrane technique, using a human acellular dermal matrix (hADM), is an experimental method for treating large bone defects. This eliminates the need for the Masquelet membrane induction step, shortening the procedure while maintaining effectiveness. However, previous studies showed that colonizing hADM with bone marrow mononuclear cells (BMC) worsens healing, likely due to the presence of CD8+ lymphocytes, which negatively affect bone regeneration. This study aims to investigate whether the negative impact of BMC on bone healing in this technique is due to the CD8+ cell population. A 5 mm femoral defect was created in 25 male Sprague-Dawley rats, divided into three groups (G1-G3). BMC were isolated from syngenic donor rats, with CD8+ lymphocytes removed magnetically from the BMC fraction in one group. The defects were filled with bone chips and wrapped with differently treated hADM: G1 received native hADM, G2 received hADM+BMC, and G3 received hADM+BMC-CD8. After 8 weeks, the femurs were evaluated through radiological, biomechanical, and histological examinations. Bone defects and bone mineral density (BMD) were significantly improved in G3 (hADM+BMC-CD8) compared to G2 (hADM+BMC). Bone volume, bone formation, and median bending stiffness were higher in G3. Immunohistological analysis showed a significant decrease in CD8 cell count in G3, with a lower percentage of IFNγ-producing cells compared to G2. Depleting CD8+ cells from BMC before colonizing hADM significantly improved bone healing, likely due to changes in the local mediator environment. This suggests that preoperative colonization with CD8+-depleted BMC could enhance the one-step membrane technique.

Spleen shear wave elastography measurements do not correlate with histological grading of liver fibrosis in Fontan physiology: a preliminary investigation.

Elevated spleen stiffness may be seen in patients with portal hypertension due to cirrhosis. In patients with Fontan physiology, elevated liver stiffness has been shown to correlate poorly with liver fibrosis. It is unknown whether spleen stiffness may instead serve as a surrogate marker of liver fibrosis in these patients. To compare spleen stiffness determined by shear wave elastography (SWE) with histological findings of an ultrasound-guided liver biopsy in patients who had undergone Fontan palliation as a potential surrogate for Fontan-associated liver disease. This was an IRB-approved single-center, retrospective study. Patients with Fontan palliation who had undergone both a spleen SWE study and a percutaneous liver biopsy between 2016 and 2020 were included. Biopsy, performed during cardiac catheterization, within 3months of the SWE was required for inclusion. Using Kruskal-Wallis tests, spleen stiffness was compared with three liver biopsy scoring methods: Ishak, METAVIR, and congestive hepatic fibrosis score (CHFS). When available, Pearson's correlation was also used to compare collagen deposition determined using Sirius Red stain (%SR) with SWE values. A P-value < 0.05 was considered statistically significant. Twenty-two patients (15 males) were included in the study, with a median age of 17years (IQR is 14.8-20.5years; age range: 7years to 30.2years). The median spleen stiffness was 2.94m/s (IQR: 2.57-3.61m/s; range: 1.48-4.27m/s). The median Fontan pressure was 11mm Hg (IQR: 10-13.3mm Hg; range: 7-19mm Hg) obtained within a median of 10days (IQR: 1-41days) of SWE. Splenic stiffness did not correlate with the extent of fibrosis determined by histology (all P > 0.05). There was also no statistically significant correlation between the %SR staining and SWE-determined spleen stiffness (Pearson's correlation of 0.165, P = 0.59, n = 13). In this preliminary study, SWE spleen stiffness values did not correlate with biopsy-determined scoring of liver fibrosis in patients with Fontan physiology.

Liver and spleen shear-wave elastography in the diagnosis and severity staging of myeloproliferative diseases and myelofibrosis.

Spleen and liver stiffness, investigated by VCTE (Vibration-Controlled Transient Elastography), have been associated with marrow fibrosis in patients with myeloproliferative neoplasms (MPNs). Tissue stiffness can be assessed by shear wave point (pSWE) and bidimensional elastography (2DSWE). Spleen stiffness (SS)values were higher in Myelofibrosis (MF) and Polycythemia Vera (PV) compared to Essential Thrombocythemia (ET). We aimed to identify SWE differences between MPN patients and healthy volunteers; to evaluate specific SWE features in patients with MF, PV and ET; to establish a correlation with bone marrow fibrosis in patients with myeloproliferative disease. Patients with myeloproliferative disease and healthy volunteers performed evaluation of spleen and liver stiffness (LS)by pSWE and 2DSWE. A total of 218 subjects were included: 143 with myeloproliferative disease (64 MF, 29.4%, 33 PV, 15.1% and 46 ET, 21.1%), and 75 (34.4%) healthy volunteers. Compared to volunteers, MF patients had greater spleen (pSWE 40.9 vs. 26.3kPa, p < 0.001; 2DSWE 34.9 vs. 20.1kPa, p < 0.001), and liver stiffness (pSWE 7.72 vs. 5.52kPa, p < 0.001; 2DSWE 6.96 vs. 5.01kPa, p < 0.001). In low (0-1) (n = 81, 60.4%) versus high-grade bone marrow fibrosis (2-3) (n = 42, 39.6%), is evident a higher median stiffness in patients with higher grades of fibrosis both for liver (pSWE 5.2 vs. 6.65kPa; 2DSWE 5.1 vs. 6.05kPa) and spleen (pSWE 27.2 vs. 37.9kPa, 2DSWE 21.7 vs 30.75kPa-p < 0.001 in both). SWE evaluation distinguishes MF patients from HV and ET/PV and may help in MPN diagnosis. LS and SS values are associated with bone marrow fibrosis grade.

Natural History and Management of Hepatitis C in Children: 25 Years Experience of a Reference Center in Northern Italy.

Hepatitis C virus (HCV) infection natural history and management in the pediatric population are still debated. We retrospectively evaluated the outcome of a HCV pediatric population managed at the Pediatric Infectious Disease Unit of Luigi Sacco Hospital (Milan, Italy) from January 1997 to January 2022 (median follow-up 10 years) and we focused on the role of new drugs and transient elastography. Fifty-seven patients were enrolled: 8 (14%) had a spontaneous clearance, 33 were treated (58%), 7 (12%) were not treated because they were under 12 years old and 9 were lost at follow-up. HCV RNA was undetectable in all treated patients at the end of therapy, after 12 weeks (SVR12) and for the rest of their follow-up. All patients treated underwent elastography before and 1 year after therapy. Median stiffness pretherapy was 5.6 kPa, and 9 patients (16%) had abnormal transient elastography (>7 kPa, median 8.7 kPa). Median stiffness after treatment in the abnormal group was 6.8 kPa. Direct-acting antiviral agents are a safe and effective therapy for HCV chronic infection in the pediatric population. Liver elastography is normal in many vertically infected children before 12 years, but, when abnormal, it shows a significant improvement after direct-acting antiviral agent treatment. Further studies are needed to evaluate the role of elastography at diagnosis and follow-up in children.

Functional MR elastography measures visual cortex stiffening proportional to visual contrast intensity in regions of activation

Abstract Functional MRI (fMRI) is widely used to spatially localize neural activity in the brain associated with functional stimuli. Functional MR Elastography (fMRE) has recently been introduced as a complementary approach that measures the mechanical response to functional stimulus. The hypothesis of the current study is that the stiffness change in fMRE is proportional to the underlying neural activity. This hypothesis is tested by measuring the median stiffness change in the visual cortex as a function of luminance-matched contrast intensity of a checkerboard visual stimulus in 16 healthy subjects. The fMRE signal in the visual cortex was observed to be proportional to the contrast intensity of the visual stimulus. In regions of activation, fMRE signal increased in the range of 2 ± 1% to 5.8 ± 1% and fMRI signal increased by the expected 0.4 ± 0.2% to 0.9 ± 0.2%, for contrast levels of 5% to 100%, respectively. In conclusion, this study shows that the fMRE signal in the visual cortex can be directly modulated by the contrast intensity of a visual stimulus. The presence of some overlap between fMRI and fMRE regions of activation may suggest two distinct mechanisms governing the fMRI and fMRE signals, which will be investigated in future studies.

Elastography of nerves in the wrists of cyclists.

This study aimed to investigate changes in the elasticity of the median and ulnar nerves in cyclists. The study included 30 cyclists and 2 non-biking reference groups that included 32 healthy volunteers and 32 individuals with ulnar nerve entrapment neuropathies. All participants underwent physical, ultrasonographic, and elastographic examinations including assessment of nerve cross-sectional area (CSA) and stiffness (SWE). The cyclists' group was tested before and after a 2-hour workout. The values of ulnar nerve CSA and stiffness in Guyon's canal in resting cyclists were 5.30 ± 1.51 mm2 and 49.05 ± 11.18 kPa, respectively. These values were significantly higher than in the healthy volunteers, but not higher than in the nerve entrapment group. Median nerve CSA and stiffness at rest were 9.10 ± 2.61 mm2 and 38.54 ± 14.87 kPa, respectively. Both values were higher than respective values in the healthy group. Cycling induced an increase in all these parameters, although the increase in nerve stiffness was more noticeable than in CSA. The elasticity of the median and ulnar nerve in cyclists remains within normal limits, questioning the belief that cyclists are at risk of nerve palsy in Guyon's canal. However, cycling workout does exert compression, resulting in transient oedema of both nerves. The dynamics of changes was more noticeable in SWE examination than in conventional ultrasound, which may depend on SWE sensitivity.

A case for shunt surgery in a patient with Portal Biliopathy with High Bilirubin and High Liver median stiffness.

A case for shunt surgery in a patient with Portal Biliopathy with High Bilirubin and High Liver median stiffness.

Comparison of Staple, Anchor, and Tenodesis Screw for Posterior Tibialis Tendon Fixation: A Biomechanical Analysis

Various posterior tibialis tendon fixation techniques are described in literature. Suture anchor, staple and tenodesis screws are widely used for posterior tibialis tendon transfer, but their stiffness and the maximal ultimate failure load were not tested before. We aimed to compare the initial ultimate failure load and stiffnesses of suture anchor, staple and tenodesis screws on bovine tendon fixation to bovine metaphyseal bone. Thirty-five fresh bovine ankle joints and hooves were obtained from a local abattoir. Metatarsals bones with long extensor tendons were harvested. Staple group had 15, suture anchor group had 10, and tenodesis screw group had 10 samples. All fixations were tested with Instron® ElectroPuls® E10000 Test Instrument. Ultimate failure load and failure location were noted. Staple group's median ultimate failure load was 210.03 N (IQR: 133.43), suture anchor group's was 124.33 N (IQR: 63.67), and tenodesis screw group's was 394.46 N (IQR:115.09). Median stiffness of the staple group was 19.87 N/m (IQR: 15.29); the tenodesis screw group's was 20.28 N/m (IQR: 6.18), the anchor group's was 8.54 N/m (IQR: 4.35). Staples' failure occurred on tendon-staple interface, while suture anchors' occurred on anchor-suture interface and tenodesis screws' occurred on tendon-suture interface. Tenodesis screws' ultimate failure load was the highest (tenodesis vs anchor and staple p < .001 and p=.032, respectively). Staple fixation is less expensive than the other methods and can provide sufficient fixation strength but was weaker than the tenodesis screw fixation. Staples are still a good choice for tendon to bone fixation, whereas the suture anchors provide lower fixation strength at a higher cost.

Utility of shear wave elastography for diagnosing carpal tunnel syndrome with psoriatic arthritis.

Carpal tunnel syndrome (CTS) is a type of peripheral entrapment neuropathy and common for the patients with psoriatic arthritis (PsA). Shear wave elastography (SWE) is a new ultrasonography technique that can be used for diagnosing CTS, but not studied in PsA patients. The aim of this study to measure the stiffness of median nerve and hand muscles by quantitative SWE to identify whether SWE can be used for diagnosing CTS in patients with PsA or not. To diagnose CTS, all patients had electrodiagnostic study. The stiffness values of the median nerve, abductor pollicis brevis, and abductor digiti minimi were determined using SWE. Muscle stiffness ratio was also calculated. Consideration is given to 48 patients with PsA (93 wrists) and 29 healthy volunteers (57 wrists). Median nerve stiffness was found to be significantly higher, and abductor pollicis brevis' stiffness and muscle stiffness ratio were significantly lower in PsA patients' wrists compared to control group (p = 0.002, p < 0.001, p = 0.001, respectively) and in CTS wrists compared to others (p < 0.001, p < 0.001, p = 0.001, respectively). Receiver operating characteristic analysis identified 28.2 kPA as the median nerve stiffness cut-off point for differentiating CTS in PsA patients (p = 0.001). We found that SWE has a good diagnostic value for CTS with PsA patients; hence, we can conclude that SWE could diagnose CTS in PsA patients.

Shear wave elastography parameters adds prognostic value to adverse outcome in kidney transplantation recipients

Introduction The tissue stiffness of donor kidneys in transplantation may increase due to pathological changes such as glomerulosclerosis and interstitial fibrosis, and those changes associate worse outcomes in kidney transplantation recipients. Ultrasound elastography is a noninvasive imaging examination with the ability to quantitatively reflect tissue stiffness. Aim of this study was to evaluate the prognostic value of ultrasound elastography for adverse kidney outcome in kidney transplantation recipients. Methods Shear wave elastography (SWE) examinations were performed by two independent operators in kidney transplantation recipients. The primary outcome was a composite of kidney graft deterioration, all-cause re-hospitalization, and all-cause mortality. Survival analysis was calculated by Kaplan-Meier curves with the log-rank test and Cox regression analysis. Results A total of 161 patients (mean age 46 years, 63.4% men) were followed for a median of 20.1 months. 27 patients (16.77%) reached the primary endpoint. The mean and median tissue stiffness at the medulla (hazard ratio: 1.265 and 1.229, respectively), estimated glomerular filtration rate (eGFR), and serum albumin level were associated with the primary outcome in univariate Cox regression. Adding mean or median medulla SWE to a baseline model containing eGFR and albumin significantly improved its discrimination (C-statistics: 0.736 for the baseline, 0.766 and 0.772 for the model added mean and median medulla SWE, respectively). Conclusion The medullary tissue stiffness of kidney allograft measured by shear wave elastography may provide incremental prognostic value to adverse outcomes in kidney transplantation recipients. Including SWE parameters in kidney transplantation recipients management could be considered to improve risk stratification.

Fixation of transverse midshaft clavicle fractures with nitinol staples vs. superior locked plating: a biomechanical study

Background: Nitinol staples have been used effectively for stabilization and compression at fracture sites. This study compared yield load, fracture displacement, and load to failure between nitinol staples and superior plating for midshaft clavicle fractures. Methods: Ten pairs of cadaveric clavicles underwent midshaft osteotomy. Each specimen in each pair was randomly assigned to fixation with superiorly placed nitinol staples or with superior plating. Specimens were loaded cyclically with increasing loads to a maximum of 1200 cycles and 60 N. Fracture displacement and construct stiffness were compared at each load. Load to failure was performed at the conclusion of testing. Results: The staple group demonstrated lower yield load and higher median fracture displacement at all levels of force compared to the plate group. Median displacement at physiologic load was 15.3 (IQR 12.8-16.5) mm for the staple construct and 2.9 (IQR 2.5-3.6) mm for plated constructs (P=2.04E-07). Median stiffness of plated constructs was significantly higher than staple constructs at all levels (P&lt;0.05). Median cycles to failure for staple constructs was significantly lower compared to plated constructs (P=0.004). Median load to failure was significantly higher for plated constructs compared to staple constructs (P=2.8E-06). Conclusions: Nitinol staple fixation of midshaft clavicle fractures demonstrated lower yield load, stiffness, increased displacement, and lower load to failure compared to superior plate fixation. However, staple constructs provided adequate stability to maintain reduction of the fracture at physiologic levels of repetitive stress, indicating a potential role for nitinol staples in clavicle fracture fixation.

1606-P: Tg/HDL Ratio and Liver Fibrosis in Diabetic Patients at an Indian Tertiary Care Center

Introduction: According to the most recent International Diabetes Federation (IDF) atlas, there are 537 million persons worldwide who have diabetes. Indians had increased central adiposity and insulin resistance. Diabetes patients are more likely to develop Nonalcoholic Fatty Liver Disease (NAFLD) due to high insulin resistance. An increasingly sensitive indicator of insulin resistance is the TG/HDL ratio. Measuring liver stiffness helps diabetics predict progressive fibrosis. The current investigation uses fibro scans to evaluate the TG/HDL ratio and liver stiffness in diabetic patients. Methods: After receiving consent, 181 newly diagnosed diabetics underwent fibro scans to measure their liver stiffness. Participants who had already had thiazolidinedione treatment or lipid-lowering therapy were disqualified from the study. Results: The median stiffness ranged from 2.3 kpa to 34.8 kpa (8.0 kpa), and the median TG/HDL ratio ranged from 0.5 to 29.3 (4.5). The connection between the median stiffness and the TG/HDL ratio was 0.2. Further, 26.5% of participants (Liver stiffness measurement (LSM) &amp;gt; 9.1), 23.7% of subjects who were men, and 30% of subjects who were women, showed advanced fibrosis. Both men and women with LSM &amp;gt; 9.1 had high TG/HDL ratios, with a mean of 4.9 in the former group and 4.9 in the latter. These numbers were significantly higher than the TG/HDL cut-offs for predicting insulin resistance, which were 0.9 and 1.2 for females and males, respectively. Conclusion: TG/HDL ratio and NAFLD have previously been linked utilising ultrasonography in nondiabetic persons. The more precise and sensitive method for NAFLD screening is the fibro scan. Liver fibrosis is predicted by median stiffness. In the index research, there is a high incidence of advanced fibrosis, which is associated with the TG/HDL ratio. The TG/HDL ratio was high in all of the male and female individuals with advanced fibrosis. Disclosure A. Chandra: None. J. Dinkar: None. R. Ranjan: None.

Granulocytes-Rich Thrombi in Cerebral Large Vessel Occlusion Are Associated with Increased Stiffness and Poorer Revascularization Outcomes.

We aim to identify a profile of intracranial thrombus resistant to recanalization by mechanical thrombectomy (MT) in acute stroke treatment. The first extracted clot of each MT was analyzed by flow cytometry obtaining the composition of the main leukocyte populations: granulocytes, monocytes, and lymphocytes. Demographics, reperfusion treatment, and grade of recanalization were registered. MT failure (MTF) was defined as final thrombolysis in cerebral infarction score IIa or lower and/or need of permanent intracranial stenting as a rescue therapy. To explore the relationship between stiffness of intracranial clots and cellular composition, unconfined compression tests were performed in other cohorts of cases. Thrombi obtained in 225 patients were analyzed. MTF were observed in 30 cases (13%). MTF was associated with atherosclerosis etiology (33.3% vs. 15.9%; p = 0.021) and higher number of passes (3 vs. 2; p < 0.001). Clot analysis of MTF showed higher percentage of granulocytes [82.46 vs. 68.90% p < 0.001] and lower percentage of monocytes [9.18% vs.17.34%, p < 0.001] in comparison to successful MT cases. The proportion of clot granulocytes (aOR 1.07; 95% CI 1.01-1.14) remained an independent marker of MTF. Among thirty-eight clots mechanically tested, there was a positive correlation between granulocyte proportion and thrombi stiffness (Pearson's r = 0.35, p = 0.032), with a median clot stiffness of 30.2 (IQR, 18.9-42.7) kPa. Granulocytes-rich thrombi are harder to capture by mechanical thrombectomy due to increased stiffness, so a proportion of intracranial granulocytes might be useful to guide personalized endovascular procedures in acute stroke treatment.

Ultrasound-guided breast biopsy using an adapted automated cone-based ultrasound scanner: a feasibility study.

Among available breast biopsy techniques, ultrasound (US)-guided biopsy is preferable because it is relatively inexpensive and provides live imaging feedback. The availability of magnetic resonance imaging (MRI)-3D US image fusion would facilitate US-guided biopsy even for US occult lesions to reduce the need for expensive and time-consuming MRI-guided biopsy. In this paper, we propose a novel Automated Cone-based Breast Ultrasound Scanning and Biopsy System (ACBUS-BS) to scan and biopsy breasts of women in prone position. It is based on a previously developed system, called ACBUS, that facilitates MRI-3D US image fusion imaging of the breast employing a conical container filled with a coupling medium. The purpose of this study was to introduce the ABCUS-BS system and demonstrate its feasibility for biopsy of US occult lesions. The biopsy procedure with the ACBUS-BS comprises four steps: target localization, positioning, preparation, and biopsy. The biopsy outcome can be impacted by 5 types of errors: due to lesion segmentation, MRI-3D US registration, navigation, lesion tracking during repositioning, and US inaccuracy (due to sound speed difference between the sample and the one used for image reconstruction). For the quantification, we use a soft custom-made polyvinyl alcohol phantom (PVA) containing 8 lesions (3 US-occult and 5 US-visible lesions of 10 mm in diameter) and a commercial breast mimicking phantom with a median stiffness of 7.6 kPa and 28 kPa, respectively. Errors of all types were quantified using the custom-made phantom. The error due to lesion tracking was also quantified with the commercial phantom. Finally, the technology was validated by biopsying the custom-made phantom and comparing the size of the biopsied material to the original lesion size. The average size of the 10-mm-sized lesions in the biopsy specimen was 7.00 ± 0.92 mm (6.33 ± 1.16 mm for US occult lesions, and 7.40 ± 0.55 mm for US-visible lesions). For the PVA phantom, the errors due to registration, navigation, lesion tracking during repositioning, and US inaccuracy were 1.33 mm, 0.30 mm, 2.12 mm, and 0.55 mm. The total error was 4.01 mm. For the commercial phantom, the error due to lesion tracking was estimated at 1.10 mm, and the total error was 4.11 mm. Given these results, the system is expected to successfully biopsy lesions larger than 8.22 mm in diameter. Patient studies will have to be carried out to confirm this in vivo. The ACBUS-BS facilitates US-guided biopsy of lesions detected in pre-MRI and therefore might offer a low-cost alternative to MRI-guided biopsy. We demonstrated the feasibility of the approach by successfully taking biopsies of 5 US-visible and 3 US-occult lesions embedded in a soft breast-shaped phantom. This article is protected by copyright. All rights reserved.

Measurement of renal congestion and compliance following intravenous fluid administration using shear wave elastography

ObjectiveUltrasound shear wave elastography (SWE) is a novel technique that may provide non-invasive measurements of renal compliance. We aimed to investigate the relationship between intravenous (IV) fluid administration and change in SWE measurements. We hypothesised that following IV fluid administration in healthy volunteers, global kidney stiffness would increase and that this increase in stiffness could be quantified using SWE. Our second hypothesis was that graduated doses of IV fluids would result in a dose-dependent increase in global kidney stiffness measured by SWE. DesignRandomised prospective study. SettingIntensive Care Unit. ParticipantsHealthy volunteers aged 18–40 years. InterventionsParticipants were randomised to receive 20 ml/kg, 30 ml/kg, or 40 ml/kg of normal saline. The volume of fluid infused was based on the actual body weight recorded. Main outcome measuresWe recorded average SWE stiffness (kPa with standard deviation of the mean), median SWE stiffness (kPa), and the interquartile range. ResultsNinety-eight percent of participants (44/45) demonstrated an increase in global kidney stiffness following administration of IV fluids. The average SWE pre fluid administration was 7.572 kPa ± 2.38 versus 14.9 kPa ± 4.81 post fluid administration (p < 0.001). In subgroup analysis, there were significant changes in global kidney stiffness pre and post fluid administration with each volume (ml/kg) of fluid administered. Average percentage change in global kidney stiffness from baseline was compared between the three groups. There was no significant difference when comparing groups 1 and 2 (197.1% increase ± 49.5 vs 216.1% ± 72.0, p ¼ 0.398), groups 2 and 3 (216.1% increase ± 72.0 vs 197.8% ± 59.9, p ¼ 0.455), or groups 1 and 3 (197.1% increase ± 49.5 vs 197.8% ± 59.9, p ¼ 0.972). ConclusionsFluid administration results in immediately visible and quantifiable changes in global kidney stiffness across all infused volumes of fluid.

Nanomechanical Signatures in Glioma Cells Depend on CD44 Distribution in IDH1 Wild-Type but Not in IDH1R132H Mutant Early-Passage Cultures

Atomic force microscopy (AFM) recently burst into biomedicine, providing morphological and functional characteristics of cancer cells and their microenvironment responsible for tumor invasion and progression, although the novelty of this assay needs to coordinate the malignant profiles of patients' specimens to diagnostically valuable criteria. Applying high-resolution semi-contact AFM mapping on an extended number of cells, we analyzed the nanomechanical properties of glioma early-passage cell cultures with a different IDH1 R132H mutation status. Each cell culture was additionally clustered on CD44+/- cells to find possible nanomechanical signatures that differentiate cell phenotypes varying in proliferative activity and the characteristic surface marker. IDH1 R132H mutant cells compared to IDH1 wild-type ones (IDH1wt) characterized by two-fold increased stiffness and 1.5-fold elasticity modulus. CD44+/IDH1wt cells were two-fold more rigid and much stiffer than CD44-/IDH1wt ones. In contrast to IDH1 wild-type cells, CD44+/IDH1 R132H and CD44-/IDH1 R132H did not exhibit nanomechanical signatures providing statistically valuable differentiation of these subpopulations. The median stiffness depends on glioma cell types and decreases according to the following manner: IDH1 R132H mt (4.7 mN/m), CD44+/IDH1wt (3.7 mN/m), CD44-/IDH1wt (2.5 mN/m). This indicates that the quantitative nanomechanical mapping would be a promising assay for the quick cell population analysis suitable for detailed diagnostics and personalized treatment of glioma forms.

Abstract 95: High Proportion Of Granulocytes Form Intracranial Thrombus Is Associated With Increased Stiffness And Resistance To Endovascular Recanalization

Hypothesis: We aim to identify a profile of intracranial thrombus resistant to recanalization by standard mechanical thrombectomy (MT) in acute stroke treatment. Methods: First extracted clot of each MT were analyzed by Flow Cytometry obtaining composition of main leukocyte populations: granulocytes, monocytes and lymphocytes. Demographics, reperfusion treatment and grade of recanalization were registered. MT Failure ( MTF) was defined as final Thrombolysis in Cerebral Infarction score IIa or lower and/ or need of permanent intracranial stenting as a rescue therapy after standard MT. In other cohort of cases, unconfined compression tests were performed to explore stiffness of retrieved clots . We looked for correlation between mechanical characterization tests and clot composition. Results: Among 225 patients, there were 13 % of MTF that were significantly associated to atherosclerosis etiology ( 33.3% vs. 15.9% ; p 0.021) , more passes ( 3 vs. 2; p &lt;0.001), higher proportion of clot granulocytes ( 82.46% vs. 68.90% ; p &lt;0.001) and lower proportion of clot monocytes ( 9.18% vs.17.34% ; p&lt;0.001). The proportion of clot granulocytes (aOR 1.07; 95% CI 1.01-1.14) remained as an independent marker of MTF. Among Thirty eight clots tested by unconfined compression median clot stiffness was 30.2 (IQR, 18.9-42.7) kPa. There was a positive correlation between granulocyte proportion and thrombi stiffness (Pearson’s r=0.35, p=0.032). Conclusions: There is a positive correlation between granulocyte proportion and thrombi stiffness that may explain endovascular resistance to recanalization. Influence of granulocytes within thrombus may be a target for future reperfusion treatments.

The sono-elastography evaluation of the immediate effects of neurodynamic mobilization technique on median nerve stiffness in patients with carpal tunnel syndrome

ObjectivesThe stiffness of median nerve increases in carpal tunnel syndrome (CTS) even at mild stage of syndrome which could be regarded as a diagnostic criterion. The aim of this study was to evaluate the immediate effects of neurodynamic technique on median nerve stiffness and cross-sectional area (CSA) at wrist and elbow in individuals with CTS. Material and methodsIt was a quasi-experimental study. Twenty patients were recruited for this study. They were included if aged 18–65 years and diagnosed with CTS based on electrodiagnostic and clinical findings. The exclusion criteria were previous surgeries at wrist or elbow. Patients were assessed by shear wave sono-elastography before and immediately after one session of neurodynamic mobilization technique (NDM). The primary outcome measure was the stiffness of the median nerve at wrist and the secondary outcomes were nerve stiffness at elbow and CSA of nerve at wrist and elbow. ResultsMedian nerve stiffness and CSA decreased significantly at wrist immediately after a session of NDM. These parameters also decreased at elbow but were not statistically significant. ConclusionOne session of NDM reduced the stiffness and CSA of median nerve at wrist in patients with CTS as detected by sono-elastography verifying that sono-elastography is able to quickly detect the immediate biomechanical changes of the median nerve.

SURG-21. DEVELOPMENT OF MICROSURGICAL FORCEPS EQUIPPED WITH HAPTICS TECHNOLOGY FOR IN SITU DIFFERENTIATION OF TUMOR TISSUE FROM NORMAL BRAIN DURING MICROSURGERY BY TISSUE STIFFNESS

Abstract Neurosurgeons perform tumor resection based on their tactile perception. However, many years of experience and training are required to appropriately differentiate tumor tissue from surrounding parenchymal tissue. It was reported that the stiffness of human cancer tissue strongly correlates with pathological tissue and it can be used as a biomarker. Comprehensive analysis also revealed that the molecular expression differs greatly between hard and soft tumors.Haptics technology measures and uses the stimulus that causes the sensation as a physical quantity. Force and tactile sensation is a sensation caused by mechanical contact with an object. Real Haptics is our main research field, which is a general term for technologies that quantify and utilize the force-tactile stimuli generated by contact with objects that exist in the real world and / or the virtual world.We have developed a microsurgical forceps equipped with haptics technology to differentiate tumor tissue from surrounding brain tissue during tumor dissection. We generated and used three glioblastoma cell lines (SF126, U87, U251) expressing proteins of firefly luciferase and mCherry. Each cell line was transplanted into forebrain of 5 nude mice. Tumor progression was regularly monitored with In Vivo Imaging System (IVIS) and mice were euthanized at the appropriate stage. Tumor and normal brain stiffness were measured by using the Master-slave integrated haptic forceps device. Importantly, all of the three glioblastomas were shown to be harder than the normal brain (p=0.047). The median stiffness of each tissue was as follows. Normal brain (n=15): 149.98 N/m, SF126 (n=5): 207.70 N/m, U87 (n=5): 214.40 N/m, U251 (n=5): 188.86 N/mThis pilot study showed that brain tumors could be differentiated by their stiffness from normal brain, and the forceps equipped with haptics technology might help the neurosurgeons to dissect tumor margin along the appropriate plane.

ODP174 Correlation of Advanced Fibrosis and Coronary Artery Disease Risk Scores in People With Type 2 Diabetes in a Tertiary Care Centre

Abstract Nonalcoholic fatty liver disease (NAFLD) and Type 2 diabetes mellitus (T2DM) are common conditions that often coexist and can act synergistically to cause adverse effects. The presence of both NAFLD and T2DM increases the likelihood of developing diabetes complications (including both macro and microvascular complications), and enhances the risk of cirrhosis, hepatocellular carcinoma and death. NAFLD screening is often neglected in routine clinical practice. Fibro scan is a more sensitive modality for diagnosis of liver fibrosis and scarring. Liver stiffness measurements predict advanced fibrosis in people with diabetes The current study aims to correlate liver stiffness measurements and coronary artery disease risk scores in people with type 2 diabetes in a tertiary care centre Material and Methods: - A total of 181 people with diabetes coming for the first time at our centre underwent liver stiffness measurements using fibro scan after taking consent, people on prior lipid-lowering therapy and thiazolidinedione therapy were excluded from the study. We used the risk score model for the assessment of coronary artery disease in asymptomatic patients with type 2 diabetes [ https://paperpile.com/c/XKqsdv/PpmxP 1 ] because it was easy to use, specific for Asian population and validated with coronary computed tomographic angiography (CCTA) in asymptomatic people with type 2 diabetes. Out of the total of 181 subjects 51% were males and 49% were females, mean age was 50.2 years, duration of diabetes was 7.6years, Hba1c values ranged from 6. 0%-15%(mean 8.5%), median stiffness ranged from 2.3kpa to 34.8kpa (median of 8. 0kpa).50 out of 181(27.62%) had advanced fibrosis(liver stiffness measurements(LSM values of &amp;gt;9. 0). Advanced fibrosis had a significant(p&amp;lt;. 001) correlation with coronary artery risk scores with a correlation coefficient of 0.570. Advanced fibrosis is associated with increased risk of coronary artery disease in people with type 2 diabetes BIBLIOGRAPHY 1. http://paperpile.com/b/XKqsdv/PpmxP. Park G-M, An H, Lee S-W, Cho Y-R, Gil EH, Her SH, et al. Risk Score Model for the Assessment of Coronary Artery Disease in Asymptomatic Patients With Type 2 Diabetes. Medicine [Internet]. 2015 Jan [cited 2020 Oct 14];94(4): e508. Available from: https://journals.lww.com/md-journal/Fulltext/2015/01040/Risk_Score_Model_for_the_Assessment_of_Coronary.44.aspx Presentation: No date and time listed