Publications by authors named "Giovanni Cappello"

39 Publications

Assessment of morphological CT imaging features for the prediction of risk stratification, mutations, and prognosis of gastrointestinal stromal tumors.

Eur Radiol 2021 Apr 21. Epub 2021 Apr 21.

Department of Biomedicine, Neuroscience and Advanced Diagnostics (BiND), University of Palermo, Via del Vespro 129, 90127, Palermo, Italy.

Objectives: To investigate the correlation between CT imaging features and risk stratification of gastrointestinal stromal tumors (GISTs), prediction of mutation status, and prognosis.

Methods: This retrospective dual-institution study included patients with pathologically proven GISTs meeting the following criteria: (i) preoperative contrast-enhanced CT performed between 2008 and 2019; (ii) no treatments before imaging; (iii) available pathological analysis. Tumor risk stratification was determined according to the National Institutes of Health (NIH) 2008 criteria. Two readers evaluated the CT features, including enhancement patterns and tumor characteristics in a blinded fashion. The differences in distribution of CT features were assessed using univariate and multivariate analyses. Survival analyses were performed by using the Cox proportional hazard model, Kaplan-Meier method, and log-rank test.

Results: The final population included 88 patients (59 men and 29 women, mean age 60.5 ± 11.1 years) with 45 high-risk and 43 low-to-intermediate-risk GISTs (median size 6.3 cm). At multivariate analysis, lesion size ≥ 5 cm (OR: 10.52, p = 0.009) and enlarged feeding vessels (OR: 12.08, p = 0.040) were independently associated with the high-risk GISTs. Hyperenhancement was significantly more frequent in PDGFRα-mutated/wild-type GISTs compared to GISTs with KIT mutations (59.3% vs 23.0%, p = 0.004). Ill-defined margins were associated with shorter progression-free survival (HR 9.66) at multivariate analysis, while ill-defined margins and hemorrhage remained independently associated with shorter overall survival (HR 44.41 and HR 30.22). Inter-reader agreement ranged from fair to almost perfect (k: 0.32-0.93).

Conclusions: Morphologic contrast-enhanced CT features are significantly different depending on the risk status or mutations and may help to predict prognosis.

Key Points: • Lesions size ≥ 5 cm (OR: 10.52, p = 0.009) and enlarged feeding vessels (OR: 12.08, p = 0.040) are independent predictors of high-risk GISTs. • PDGFRα-mutated/wild-type GISTs demonstrate more frequently hyperenhancement compared to GISTs with KIT mutations (59.3% vs 23.0%, p = 0.004). • Ill-defined margins (hazard ratio 9.66) were associated with shorter progression-free survival at multivariate analysis, while ill-defined margins (hazard ratio 44.41) and intralesional hemorrhage (hazard ratio 30.22) were independently associated with shorter overall survival.
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http://dx.doi.org/10.1007/s00330-021-07961-3DOI Listing
April 2021

Extracellular matrix in multicellular aggregates acts as a pressure sensor controlling cell proliferation and motility.

Elife 2021 Mar 11;10. Epub 2021 Mar 11.

Université Grenoble Alpes, Laboratoire Interdisciplinaire de Physique, CNRS, Grenoble, France.

Imposed deformations play an important role in morphogenesis and tissue homeostasis, both in normal and pathological conditions. To perceive mechanical perturbations of different types and magnitudes, tissues need appropriate detectors, with a compliance that matches the perturbation amplitude. By comparing results of selective osmotic compressions of CT26 mouse cells within multicellular aggregates and global aggregate compressions, we show that global compressions have a strong impact on the aggregates growth and internal cell motility, while selective compressions of same magnitude have almost no effect. Both compressions alter the volume of individual cells in the same way over a shor-timescale, but, by draining the water out of the extracellular matrix, the global one imposes a residual compressive mechanical stress on the cells over a long-timescale, while the selective one does not. We conclude that the extracellular matrix is as a sensor that mechanically regulates cell proliferation and migration in a 3D environment.
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http://dx.doi.org/10.7554/eLife.63258DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8064752PMC
March 2021

Antibacterial and Anti-Inflammatory Activity of an Antimicrobial Peptide Synthesized with D Amino Acids.

Antibiotics (Basel) 2020 Nov 24;9(12). Epub 2020 Nov 24.

Department of Medical Biotechnologies, University of Siena, 53100 Siena, Italy.

The peptide SET-M33 is a molecule synthesized in tetra-branched form which is being developed as a new antibiotic against Gram-negative bacteria. Its isomeric form with D amino acids instead of the L version (SET-M33D) is also able to kill Gram-positive bacteria because of its higher resistance to bacterial proteases (Falciani et al., , 2012, 7, e46259). Here we report the strong in vitro activity of SET-M33D (MIC range 0.7-6.0 µM) against multiresistant pathogens of clinical interest, including Gram-positives , , and , and various Gram-negative enterobacteriaceae. SET-M33D antibacterial activity is also confirmed in vivo against a MRSA strain of with doses perfectly compatible with clinical use (5 and 2.5 mg/Kg). Moreover, SET-M33D strongly neutralized lipopolysaccharide (LPS) and lipoteichoic acid (LTA), thus exerting a strong anti-inflammatory effect, reducing expression of cytokines, enzymes, and transcription factors (TNF-α, IL6, COX-2, KC, MIP-1, IP10, iNOS, NF-κB) involved in the onset and evolution of the inflammatory process. These results, along with in vitro and in vivo toxicity data and the low frequency of resistance selection reported here, make SET-M33D a strong candidate for the development of a new broad spectrum antibiotic.
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http://dx.doi.org/10.3390/antibiotics9120840DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7760307PMC
November 2020

Imaging alternatives to colonoscopy: CT colonography and colon capsule. European Society of Gastrointestinal Endoscopy (ESGE) and European Society of Gastrointestinal and Abdominal Radiology (ESGAR) Guideline - Update 2020.

Endoscopy 2020 12 26;52(12):1127-1141. Epub 2020 Oct 26.

Radiology Unit, Candiolo Cancer Institute, FPO-IRCCS, Candiolo, Turin, Italy.

1: ESGE/ESGAR recommend computed tomographic colonography (CTC) as the radiological examination of choice for the diagnosis of colorectal neoplasia.Strong recommendation, high quality evidence.ESGE/ESGAR do not recommend barium enema in this setting.Strong recommendation, high quality evidence. 2: ESGE/ESGAR recommend CTC, preferably the same or next day, if colonoscopy is incomplete. The timing depends on an interdisciplinary decision including endoscopic and radiological factors.Strong recommendation, low quality evidence.ESGE/ESGAR suggests that, in centers with expertise in and availability of colon capsule endoscopy (CCE), CCE preferably the same or the next day may be considered if colonoscopy is incomplete.Weak recommendation, low quality evidence. 3: When colonoscopy is contraindicated or not possible, ESGE/ESGAR recommend CTC as an acceptable and equally sensitive alternative for patients with alarm symptoms.Strong recommendation, high quality evidence.Because of lack of direct evidence, ESGE/ESGAR do not recommend CCE in this situation.Very low quality evidence.ESGE/ESGAR recommend CTC as an acceptable alternative to colonoscopy for patients with non-alarm symptoms.Strong recommendation, high quality evidence.In centers with availability, ESGE/ESGAR suggests that CCE may be considered in patients with non-alarm symptoms.Weak recommendation, low quality evidence. 4: Where there is no organized fecal immunochemical test (FIT)-based population colorectal screening program, ESGE/ESGAR recommend CTC as an option for colorectal cancer screening, providing the screenee is adequately informed about test characteristics, benefits, and risks, and depending on local service- and patient-related factors.Strong recommendation, high quality evidence.ESGE/ESGAR do not suggest CCE as a first-line screening test for colorectal cancer.Weak recommendation, low quality evidence. 5: ESGE/ESGAR recommend CTC in the case of a positive fecal occult blood test (FOBT) or FIT with incomplete or unfeasible colonoscopy, within organized population screening programs.Strong recommendation, moderate quality evidence.ESGE/ESGAR also suggest the use of CCE in this setting based on availability.Weak recommendation, moderate quality evidence. 6: ESGE/ESGAR suggest CTC with intravenous contrast medium injection for surveillance after curative-intent resection of colorectal cancer only in patients in whom colonoscopy is contraindicated or unfeasibleWeak recommendation, low quality evidence.There is insufficient evidence to recommend CCE in this setting.Very low quality evidence. 7: ESGE/ESGAR suggest CTC in patients with high risk polyps undergoing surveillance after polypectomy only when colonoscopy is unfeasible.Weak recommendation, low quality evidence.There is insufficient evidence to recommend CCE in post-polypectomy surveillance.Very low quality evidence. 8: ESGE/ESGAR recommend against CTC in patients with acute colonic inflammation and in those who have recently undergone colorectal surgery, pending a multidisciplinary evaluation.Strong recommendation, low quality evidence. 9: ESGE/ESGAR recommend referral for endoscopic polypectomy in patients with at least one polyp ≥ 6 mm detected at CTC or CCE.Follow-up CTC may be clinically considered for 6 - 9-mm CTC-detected lesions if patients do not undergo polypectomy because of patient choice, comorbidity, and/or low risk profile for advanced neoplasia.Strong recommendation, moderate quality evidence.
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http://dx.doi.org/10.1055/a-1258-4819DOI Listing
December 2020

Imaging alternatives to colonoscopy: CT colonography and colon capsule. European Society of Gastrointestinal Endoscopy (ESGE) and European Society of Gastrointestinal and Abdominal Radiology (ESGAR) Guideline - Update 2020.

Eur Radiol 2021 May;31(5):2967-2982

Radiology Unit, Candiolo Cancer Institute, FPO-IRCCS, Candiolo, Turin, Italy.

Main Recommendations: 1. ESGE/ESGAR recommend computed tomographic colonography (CTC) as the radiological examination of choice for the diagnosis of colorectal neoplasia. Strong recommendation, high quality evidence. ESGE/ESGAR do not recommend barium enema in this setting. Strong recommendation, high quality evidence.2. ESGE/ESGAR recommend CTC, preferably the same or next day, if colonoscopy is incomplete. The timing depends on an interdisciplinary decision including endoscopic and radiological factors. Strong recommendation, low quality evidence. ESGE/ESGAR suggests that, in centers with expertise in and availability of colon capsule endoscopy (CCE), CCE preferably the same or the next day may be considered if colonoscopy is incomplete. Weak recommendation, low quality evidence.3. When colonoscopy is contraindicated or not possible, ESGE/ESGAR recommend CTC as an acceptable and equally sensitive alternative for patients with alarm symptoms. Strong recommendation, high quality evidence. Because of lack of direct evidence, ESGE/ESGAR do not recommend CCE in this situation. Very low quality evidence. ESGE/ESGAR recommend CTC as an acceptable alternative to colonoscopy for patients with non-alarm symptoms. Strong recommendation, high quality evidence. In centers with availability, ESGE/ESGAR suggests that CCE may be considered in patients with non-alarm symptoms. Weak recommendation, low quality evidence.4. Where there is no organized fecal immunochemical test (FIT)-based population colorectal screening program, ESGE/ESGAR recommend CTC as an option for colorectal cancer screening, providing the screenee is adequately informed about test characteristics, benefits, and risks, and depending on local service- and patient-related factors. Strong recommendation, high quality evidence. ESGE/ESGAR do not suggest CCE as a first-line screening test for colorectal cancer. Weak recommendation, low quality evidence.5. ESGE/ESGAR recommend CTC in the case of a positive fecal occult blood test (FOBT) or FIT with incomplete or unfeasible colonoscopy, within organized population screening programs. Strong recommendation, moderate quality evidence. ESGE/ESGAR also suggest the use of CCE in this setting based on availability. Weak recommendation, moderate quality evidence.6. ESGE/ESGAR suggest CTC with intravenous contrast medium injection for surveillance after curative-intent resection of colorectal cancer only in patients in whom colonoscopy is contraindicated or unfeasible. Weak recommendation, low quality evidence. There is insufficient evidence to recommend CCE in this setting. Very low quality evidence.7. ESGE/ESGAR suggest CTC in patients with high risk polyps undergoing surveillance after polypectomy only when colonoscopy is unfeasible. Weak recommendation, low quality evidence. There is insufficient evidence to recommend CCE in post-polypectomy surveillance. Very low quality evidence.8. ESGE/ESGAR recommend against CTC in patients with acute colonic inflammation and in those who have recently undergone colorectal surgery, pending a multidisciplinary evaluation. Strong recommendation, low quality evidence.9. ESGE/ESGAR recommend referral for endoscopic polypectomy in patients with at least one polyp ≥6 mm detected at CTC or CCE. Follow-up CTC may be clinically considered for 6-9-mm CTC-detected lesions if patients do not undergo polypectomy because of patient choice, comorbidity, and/or low risk profile for advanced neoplasia. Strong recommendation, moderate quality evidence. Source and scope This is an update of the 2014-15 Guideline of the European Society of Gastrointestinal Endoscopy (ESGE) and the European Society of Gastrointestinal and Abdominal Radiology (ESGAR). It addresses the clinical indications for the use of imaging alternatives to standard colonoscopy. A targeted literature search was performed to evaluate the evidence supporting the use of computed tomographic colonography (CTC) or colon capsule endoscopy (CCE). The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was adopted to define the strength of recommendations and the quality of evidence.
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http://dx.doi.org/10.1007/s00330-020-07413-4DOI Listing
May 2021

Machine learning-based prediction of microsatellite instability and high tumor mutation burden from contrast-enhanced computed tomography in endometrial cancers.

Sci Rep 2020 10 20;10(1):17769. Epub 2020 Oct 20.

Body Imaging Service, Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.

To evaluate whether radiomic features from contrast-enhanced computed tomography (CE-CT) can identify DNA mismatch repair deficient (MMR-D) and/or tumor mutational burden-high (TMB-H) endometrial cancers (ECs). Patients who underwent targeted massively parallel sequencing of primary ECs between 2014 and 2018 and preoperative CE-CT were included (n = 150). Molecular subtypes of EC were assigned using DNA polymerase epsilon (POLE) hotspot mutations and immunohistochemistry-based p53 and MMR protein expression. TMB was derived from sequencing, with > 15.5 mutations-per-megabase as a cut-point to define TMB-H tumors. After radiomic feature extraction and selection, radiomic features and clinical variables were processed with the recursive feature elimination random forest classifier. Classification models constructed using the training dataset (n = 105) were then validated on the holdout test dataset (n = 45). Integrated radiomic-clinical classification distinguished MMR-D from copy number (CN)-low-like and CN-high-like ECs with an area under the receiver operating characteristic curve (AUROC) of 0.78 (95% CI 0.58-0.91). The model further differentiated TMB-H from TMB-low (TMB-L) tumors with an AUROC of 0.87 (95% CI 0.73-0.95). Peritumoral-rim radiomic features were most relevant to both classifications (p ≤ 0.044). Radiomic analysis achieved moderate accuracy in identifying MMR-D and TMB-H ECs directly from CE-CT. Radiomics may provide an adjunct tool to molecular profiling, especially given its potential advantage in the setting of intratumor heterogeneity.
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http://dx.doi.org/10.1038/s41598-020-72475-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7575573PMC
October 2020

An innovative radiomics approach to predict response to chemotherapy of liver metastases based on CT images.

Annu Int Conf IEEE Eng Med Biol Soc 2020 07;2020:1339-1342

Liver metastases (mts) from colorectal cancer (CRC) can have different responses to chemotherapy in the same patient. The aim of this study is to develop and validate a machine learning algorithm to predict response of individual liver mts. 22 radiomic features (RF) were computed on pretreatment portal CT scans following a manual segmentation of mts. RFs were extracted from 7x7 Region of Interests (ROIs) that moved across the image by step of 2 pixels. Liver mts were classified as non-responder (R-) if their largest diameter increased more than 3 mm after 3 months of treatment and responder (R+), otherwise. Features selection (FS) was performed by a genetic algorithm and classification by a Support Vector Machine (SVM) classifier. Sensitivity, specificity, negative (NPV) and positive (PPV) predictive values were evaluated for all lesions in the training and validation sets, separately. On the training set, we obtained sensitivity of 86%, specificity of 67%, PPV of 89% and NPV of 61%, while, on the validation set, we reached a sensitivity of 73%, specificity of 47%, PPV of 64% and NPV of 57%. Specificity was biased by the low number of R- lesions on the validation set. The promising results obtained in the validation dataset should be extended to a larger cohort of patient to further validate our method.Clinical Relevance- to personalize treatment of patients with metastastic colorectal cancer, based on the likelihood of response to chemotherapy of each liver metastasis.
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http://dx.doi.org/10.1109/EMBC44109.2020.9176627DOI Listing
July 2020

Pertuzumab and trastuzumab emtansine in patients with HER2-amplified metastatic colorectal cancer: the phase II HERACLES-B trial.

ESMO Open 2020 09;5(5):e000911

Niguarda Cancer Center, Grande Ospedale Metropolitano Niguarda, Milano, Italy; Dipartimento di Oncologia ed Emato-Oncologia, Università degli Studi di Milano (La Statale), Milano, Italy. Electronic address:

Background: HER2 is a therapeutic target for metastatic colorectal cancer (mCRC), as demonstrated in the pivotal HERACLES-A (HER2 Amplification for Colo-rectaL cancer Enhanced Stratification) trial with trastuzumab and lapatinib. The aim of HERACLES-B trial is to assess the efficacy of the combination of pertuzumab and trastuzumab-emtansine (T-DM1) in this setting.

Methods: HERACLES-B was a single-arm, phase II trial, in patients with histologically confirmed wild-type and HER2+ mCRC refractory to standard treatments. HER2 positivity was assessed by immunohistochemistry and in situ hybridisation according to HERACLES criteria. Patients were treated with pertuzumab (840 mg intravenous load followed by 420 mg intravenous every 3 weeks) and T-DM1 (3.6 mg/kg every 3 weeks) until disease progression or toxicity. Primary and secondary end points were objective response rate (ORR) and progression-free survival (PFS). With a Fleming/Hern design (H0=ORR 10%; α=0.05; power=0.85), 7/30 responses were required to demonstrate an ORR ≥30% (H1).

Results: Thirty-one patients, 48% with ≥4 lines of previous therapies, were treated and evaluable. ORR was 9.7% (95% CI: 0 to 28) and stable disease (SD) 67.7% (95% CI: 50 to 85). OR/SD ≥4 months was associated with higher HER2 immunohistochemistry score (3+ vs 2+) (p = 0.03). Median PFS was 4.1 months (95% CI: 3.6 to 5.9). Drug-related grade (G) 3 adverse events were observed in two patients (thrombocytopaenia); G≤2 AE in 84% of cycles (n = 296), mainly nausea and fatigue.

Conclusions: HERACLES-B trial did not reach its primary end point of ORR; however, based on high disease control, PFS similar to other anti-HER2 regimens, and low toxicity, pertuzumab in combination with T-DM1 can be considered for HER2+mCRC as a potential therapeutic resource.

Trial Registration Number: 2012-002128-33 and NCT03225937.
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http://dx.doi.org/10.1136/esmoopen-2020-000911DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7523198PMC
September 2020

Long-term Clinical Outcome of Trastuzumab and Lapatinib for HER2-positive Metastatic Colorectal Cancer.

Clin Colorectal Cancer 2020 12 27;19(4):256-262.e2. Epub 2020 Jun 27.

Niguarda Cancer Center, Grande Ospedale Metropolitano Niguarda, Milan, Italy; Dipartimento di Oncologia ed Emato-Oncologia, Università degli Studi di Milano, Milan, Italy. Electronic address:

Background: ERBB2 amplification occurs in 5% of RAS wild-type metastatic colorectal cancer (mCRC) and it has been shown to be a target for treatment with 2 HER2-directed combinations of trastuzumab and lapatinib or trastuzumab and pertuzumab. We present long-term clinical results of trastuzumab and lapatinib (HERACLES-A trial) at 6.7 years (82 months) follow-up and focus on central nervous system (CNS) recurrences.

Patients And Methods: Patients had histologically confirmed KRAS exon 2 (codons 12 and 13) wild-type and HER2-positive mCRC. HER2 positivity was assessed by immunohistochemistry and in situ hybridization HERACLES diagnostic criteria. Patients were treated with intravenous trastuzumab 4 mg/kg loading dose, then 2 mg/kg once per week, and oral lapatinib 1000 mg per day until disease progression or toxicity. Patients who presented with symptoms or signs of CNS disease received brain computed tomography scan or magnetic resonance imaging.

Results: A total of 35 patients received trastuzumab and lapatinib and 32 were evaluable for response. One patient (3%) achieved complete response (CR), 8 (25%) partial response, and 13 (41%) stable disease. Therefore, response rate was 28%. Median progression-free survival was 4.7 months (95% confidence interval [CI] 3.7-6.1). Median overall survival was 10.0 months (95% CI 7.9-15.8). One patient achieved sustained CR still maintained at 7 years of follow-up. Progression in the central nervous system (CNS) occurred in 6 (19%) of 32 patients.

Conclusions: Long-term (6.7 years) follow-up analysis of HERACLES-A supports using of trastuzumab and lapatinib as treatment reference for KRAS wild-type, chemorefractory HER2-positive mCRC. In this subset of patients, prolongation of survival is accompanied by CNS recurrences that will require diagnostic and therapeutic attention in future studies. Clinicaltrials. Gov identifier: NCT 03225937.
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http://dx.doi.org/10.1016/j.clcc.2020.06.009DOI Listing
December 2020

Radiomics predicts response of individual HER2-amplified colorectal cancer liver metastases in patients treated with HER2-targeted therapy.

Int J Cancer 2020 12 14;147(11):3215-3223. Epub 2020 Sep 14.

Radiology Unit, Candiolo Cancer Institute, FPO-IRCCS, Candiolo, Italy.

The aim of our study was to develop and validate a machine learning algorithm to predict response of individual HER2-amplified colorectal cancer liver metastases (lmCRC) undergoing dual HER2-targeted therapy. Twenty-four radiomics features were extracted after 3D manual segmentation of 141 lmCRC on pretreatment portal CT scans of a cohort including 38 HER2-amplified patients; feature selection was then performed using genetic algorithms. lmCRC were classified as nonresponders (R-), if their largest diameter increased more than 10% at a CT scan performed after 3 months of treatment, responders (R+) otherwise. Sensitivity, specificity, negative (NPV) and positive (PPV) predictive values in correctly classifying individual lesion and overall patient response were assessed on a training dataset and then validated on a second dataset using a Gaussian naïve Bayesian classifier. Per-lesion sensitivity, specificity, NPV and PPV were 89%, 85%, 93%, 78% and 90%, 42%, 73%, 71% respectively in the testing and validation datasets. Per-patient sensitivity and specificity were 92% and 86%. Heterogeneous response was observed in 9 of 38 patients (24%). Five of nine patients were carriers of nonresponder lesions correctly classified as such by our radiomics signature, including four of seven harboring only one nonresponder lesion. The developed method has been proven effective in predicting behavior of individual metastases to targeted treatment in a cohort of HER2 amplified patients. The model accurately detects responder lesions and identifies nonresponder lesions in patients with heterogeneous response, potentially paving the way to multimodal treatment in selected patients. Further validation will be needed to confirm our findings.
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http://dx.doi.org/10.1002/ijc.33271DOI Listing
December 2020

Measuring cell displacements in opaque tissues: dynamic light scattering in the multiple scattering regime.

Biomed Opt Express 2020 Apr 31;11(4):2277-2297. Epub 2020 Mar 31.

Université Grenoble Alpes, Laboratoire Interdisciplinaire de Physique, CNRS, F-38000 Grenoble, France.

Coherent light scattered by tissues brings structural and dynamic information, at depth, that standard imaging techniques cannot reach. Dynamics of cells or sub-cellular elements can be measured thanks to dynamic light scattering in thin samples (single scattering regime) or thanks to diffusive wave spectroscopy in thick samples (diffusion regime). Here, we address the intermediate regime and provide an analytical relationship between scattered light fluctuations and the distribution of cell displacements as a function of time. We illustrate our method by characterizing cell motility inside half millimeter thick multicellular aggregates.
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http://dx.doi.org/10.1364/BOE.388360DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7173902PMC
April 2020

Imaging of Adverse Events Related to Checkpoint Inhibitor Therapy.

Diagnostics (Basel) 2020 Apr 13;10(4). Epub 2020 Apr 13.

Diagnostic and Interventional Radiology, Department of Translational Research, University of Pisa, Via Roma, 67, 56126 Pisa, Italy.

Immunotherapy with checkpoint inhibitors (ICIs) is becoming standard of practice for an increasing number of cancer types. ICIs enhance T-cell action against the cancer cells. By unbalancing the immune system ICIs may cause dysimmune toxicities, a series of disorders broadly defined immune-related adverse events (irAEs). IrAEs may affect any organ or apparatus and most frequently involve skin, colon, endocrine organs, liver, and lungs. Early identification and appropriate treatment of irAEs can improve patient outcome. The paper aims at reviewing mechanisms of the occurrence of irAEs, the importance of a proper diagnosis and the main pillars of therapy. To provide effective guidance to the comprehension of major irAEs imaging findings will be reviewed.
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http://dx.doi.org/10.3390/diagnostics10040216DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7235714PMC
April 2020

Structural transitions and mechanochemical coupling in the nucleoprotein filament explain homology selectivity and Rad51 protein cooperativity in cellular DNA repair.

Phys Rev E 2020 Mar;101(3-1):032407

Institut Curie, PSL Research University, Centre National de la Recherche Scientifique, Sorbonne Universités, UPMC Univ Paris 06, Unité Mixte de Recherche 168, 75005 Paris, France.

The nucleoprotein filament (NPF) is the fundamental element of homologous recombination (HR), a major mechanism for the repair of double-strand DNA breaks in the cell. The NPF is made of the damaged DNA strand surrounded by recombinase proteins, and its sensitivity to base-pairing mismatches is a crucial feature that guarantees the fidelity of the repair. The concurrent recombinases are also essential for several steps of HR. In this work, we used torque-sensitive magnetic tweezers to probe and apply mechanical constraints to single nucleoprotein filaments (NPFs). We demonstrated that the NPF undergoes structural transitions from a stretched to a compact state, and we measured the corresponding mechanochemical signatures. Using an active two-state model, we proposed a free-energy landscape for the NPF transition. Using this quantitative model, we explained both how the sensitivity of the NPF to the homology length is regulated by its structural transition and how the cooperativity of Rad51 favors selectivity to relatively long homologous sequences.
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http://dx.doi.org/10.1103/PhysRevE.101.032407DOI Listing
March 2020

Confocal fluorescence correlation spectroscopy through a sparse layer of scattering objects.

Opt Express 2019 Jul;27(14):19382-19397

In the presence of strong light scattering, as often encountered in biological tissue, optical microscopy becomes challenging and technical demanding. Beside image quality, the quantitative determination of molecular properties is also strongly affected by scattering. We have carried out fluorescence correlation spectroscopy (FCS) experiments, in a solution of fluorophores, through a sparse scattering layer made of dielectric beads. We observe that the fluorescence signal steadily decreases as the focus is moved away from the scattering layer. By contrast, the estimated number of molecules recovers its normal value beyond a characteristic distance of about twice the bead diameters, below which it is strongly biased. Accompanying theoretical modeling demonstrates how diffraction and refraction by the scattering layer and their impact on FCS measurements depend on size and refractive index of the beads.
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http://dx.doi.org/10.1364/OE.27.019382DOI Listing
July 2019

Confinement-Induced Transition between Wavelike Collective Cell Migration Modes.

Phys Rev Lett 2019 Apr;122(16):168101

Université Grenoble Alpes, Laboratoire Interdisciplinaire de Physique, CNRS, F-38000 Grenoble, France.

The structural and functional organization of biological tissues relies on the intricate interplay between chemical and mechanical signaling. Whereas the role of constant and transient mechanical perturbations is generally accepted, several studies recently highlighted the existence of long-range mechanical excitations (i.e., waves) at the supracellular level. Here, we confine epithelial cell monolayers to quasi-one-dimensional geometries, to force the establishment of tissue-level waves of well-defined wavelength and period. Numerical simulations based on a self-propelled Voronoi model reproduce the observed waves and exhibit a phase transition between a global and a multinodal wave, controlled by the confinement size. We confirm experimentally the existence of such a phase transition, and show that wavelength and period are independent of the confinement length. Together, these results demonstrate the intrinsic origin of tissue oscillations, which could provide cells with a mechanism to accurately measure distances at the supracellular level.
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http://dx.doi.org/10.1103/PhysRevLett.122.168101DOI Listing
April 2019

Radiologic and Genomic Evolution of Individual Metastases during HER2 Blockade in Colorectal Cancer.

Cancer Cell 2018 07;34(1):148-162.e7

Niguarda Cancer Center, Grande Ospedale Metropolitano Niguarda, Milan 20162, Italy.

Targeting HER2 is effective in 24% of ERBB2 amplified metastatic colorectal cancer; however, secondary resistance occurs in most of the cases. We studied the evolution of individual metastases during treatment to discover spatially resolved determinants of resistance. Circulating tumor DNA (ctDNA) analysis identified alterations associated with resistance in the majority of refractory patients. ctDNA profiles and lesion-specific radiographic reports revealed organ- or metastasis-private evolutionary patterns. When radiologic assessments documented progressive disease in target lesions, response to HER2 blockade was retained in other metastases. Genomic and functional analyses on samples and cell models from eight metastases of a patient co-recruited to a postmortem study unveiled lesion-specific evolutionary trees and pharmacologic vulnerabilities. Lesion size and contribution of distinct metastases to plasma ctDNA were correlated.
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http://dx.doi.org/10.1016/j.ccell.2018.06.004DOI Listing
July 2018

Optical volume and mass measurements show that mammalian cells swell during mitosis.

J Cell Biol 2015 Nov;211(4):765-74

UMR 144, Institut Curie, Centre de Recherche, 75005 Paris, France

The extent, mechanism, and function of cell volume changes during specific cellular events, such as cell migration and cell division, have been poorly studied, mostly because of a lack of adequate techniques. Here we unambiguously report that a large range of mammalian cell types display a significant increase in volume during mitosis (up to 30%). We further show that this increase in volume is tightly linked to the mitotic state of the cell and not to its spread or rounded shape and is independent of the presence of an intact actomyosin cortex. Importantly, this volume increase is not accompanied by an increase in dry mass and thus corresponds to a decrease in cell density. This mitotic swelling might have important consequences for mitotic progression: it might contribute to produce strong pushing forces, allowing mitotic cells to round up; it might also, by lowering cytoplasmic density, contribute to the large change of physicochemical properties observed in mitotic cells.
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http://dx.doi.org/10.1083/jcb.201505056DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4657168PMC
November 2015

Effect of an osmotic stress on multicellular aggregates.

Methods 2016 Feb 22;94:114-9. Epub 2015 Jul 22.

Laboratoire Interdisciplinaire de Physique, Centre National de la Recherche Scientifique, Université Joseph Fourier, Unité Mixte de Recherche 5588, 38402 St. Martin d'Hères, France. Electronic address:

There is increasing evidence that multicellular structures respond to mechanical cues, such as the confinement and compression exerted by the surrounding environment. In order to understand the response of tissues to stress, we investigate the effect of an isotropic stress on different biological systems. The stress is generated using the osmotic pressure induced by a biocompatible polymer. We compare the response of multicellular spheroids, individual cells and matrigel to the same osmotic perturbation. Our findings indicate that the osmotic pressure occasioned by polymers acts on these systems like an isotropic mechanical stress. When submitted to this pressure, the volume of multicellular spheroids decreases much more than one could expect from the behavior of individual cells.
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http://dx.doi.org/10.1016/j.ymeth.2015.07.009DOI Listing
February 2016

Compressive stress inhibits proliferation in tumor spheroids through a volume limitation.

Biophys J 2014 Oct;107(8):1821-1828

Physicochimie Curie (Institut Curie/Centre National de la Recherche Scientifique-UMR168/Université Pierre et Marie Curie), Institut Curie, Centre de Recherche, Paris, France.

In most instances, the growth of solid tumors occurs in constrained environments and requires a competition for space. A mechanical crosstalk can arise from this competition. In this article, we dissect the biomechanical sequence caused by a controlled compressive stress on multicellular spheroids (MCSs) used as a tumor model system. On timescales of minutes, we show that a compressive stress causes a reduction of the MCS volume, linked to a reduction of the cell volume in the core of the MCS. On timescales of hours, we observe a reversible induction of the proliferation inhibitor, p27Kip1, from the center to the periphery of the spheroid. On timescales of days, we observe that cells are blocked in the cell cycle at the late G1 checkpoint, the restriction point. We show that the effect of pressure on the proliferation can be antagonized by silencing p27Kip1. Finally, we quantify a clear correlation between the pressure-induced volume change and the growth rate of the spheroid. The compression-induced proliferation arrest that we studied is conserved for five cell lines, and is completely reversible. It demonstrates a generic crosstalk between mechanical stresses and the key players of cell cycle regulation. Our results suggest a role of volume change in the sensitivity to pressure, and that p27Kip1 is strongly influenced by this change.
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http://dx.doi.org/10.1016/j.bpj.2014.08.031DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4213738PMC
October 2014

Fluorescent correlation spectroscopy measurements with adaptive optics in the intercellular space of spheroids.

Biomed Opt Express 2014 Oct 29;5(10):3730-8. Epub 2014 Sep 29.

Univ. Grenoble Alpes, LIPHY, F-38000 Grenoble, France ; CNRS, LIPHY, F-38000 Grenoble, France.

In this study we demonstrate the use of adaptive optics to correct the biasing effects of optical aberrations when measuring the dynamics of molecules diffusing between cells in multicellular spheroids. Our results indicate that, on average, adaptive optics leads to a reduction of the 3D size of the point spread function that is statistically significant in terms of measured number of molecules and diffusion time. The sensorless approach, which uses the molecular brightness as optimization metric, is validated in a complex, highly heterogeneous, biological environment. This work paves the way towards the design of accurate diffusion measurements of molecules in thick biological specimens.
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http://dx.doi.org/10.1364/BOE.5.003730DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4206337PMC
October 2014

Mechanical control of cell flow in multicellular spheroids.

Phys Rev Lett 2013 Mar 26;110(13):138103. Epub 2013 Mar 26.

Physicochimie Curie (Institut Curie, CNRS-UMR168, UPMC), Centre de Recherche, 26 rue d'Ulm, 75248 Paris Cedex 05, France.

Collective cell motion is observed in a wide range of biological processes. In tumors, physiological gradients of nutrients, growth factors, or even oxygen give rise to gradients of proliferation. We show using fluorescently labeled particles that these gradients drive a velocity field resulting in a cellular flow in multicellular spheroids. Under mechanical stress, the cellular flow is drastically reduced. We describe the results with a hydrodynamic model that considers only convection of the particles by the cellular flow.
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http://dx.doi.org/10.1103/PhysRevLett.110.138103DOI Listing
March 2013

Kinesin KIFC1 actively transports bare double-stranded DNA.

Nucleic Acids Res 2013 May 29;41(9):4926-37. Epub 2013 Mar 29.

Physico-Chimie-Curie/UMR168 Institut Curie, Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, 75231 Paris, France.

During the past years, exogenous DNA molecules have been used in gene and molecular therapy. At present, it is not known how these DNA molecules reach the cell nucleus. We used an in cell single-molecule approach to observe the motion of exogenous short DNA molecules in the cytoplasm of eukaryotic cells. Our observations suggest an active transport of the DNA along the cytoskeleton filaments. We used an in vitro motility assay, in which the motion of single-DNA molecules along cytoskeleton filaments in cell extracts is monitored; we demonstrate that microtubule-associated motors are involved in this transport. Precipitation of DNA-bound proteins and mass spectrometry analyses reveal the preferential binding of the kinesin KIFC1 on DNA. Cell extract depletion of kinesin KIFC1 significantly decreases DNA motion, confirming the active implication of this molecular motor in the intracellular DNA transport.
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http://dx.doi.org/10.1093/nar/gkt204DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3643607PMC
May 2013

Probing Rad51-DNA interactions by changing DNA twist.

Nucleic Acids Res 2012 Dec 24;40(22):11769-76. Epub 2012 Nov 24.

Institut Curie, Centre de Recherche-Physico-Chimie-Curie, CNRS UMR168, Université Pierre et Marie Curie, Paris F-75231, France.

In eukaryotes, Rad51 protein is responsible for the recombinational repair of double-strand DNA breaks. Rad51 monomers cooperatively assemble on exonuclease-processed broken ends forming helical nucleo-protein filaments that can pair with homologous regions of sister chromatids. Homologous pairing allows the broken ends to be reunited in a complex but error-free repair process. Rad51 protein has ATPase activity but its role is poorly understood, as homologous pairing is independent of adenosine triphosphate (ATP) hydrolysis. Here we use magnetic tweezers and electron microscopy to investigate how changes of DNA twist affect the structure of Rad51-DNA complexes and how ATP hydrolysis participates in this process. We show that Rad51 protein can bind to double-stranded DNA in two different modes depending on the enforced DNA twist. The stretching mode is observed when DNA is unwound towards a helical repeat of 18.6 bp/turn, whereas a non-stretching mode is observed when DNA molecules are not permitted to change their native helical repeat. We also show that the two forms of complexes are interconvertible and that by enforcing changes of DNA twist one can induce transitions between the two forms. Our observations permit a better understanding of the role of ATP hydrolysis in Rad51-mediated homologous pairing and strand exchange.
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http://dx.doi.org/10.1093/nar/gks1131DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3526263PMC
December 2012

Membrane shape at the edge of the dynamin helix sets location and duration of the fission reaction.

Cell 2012 Oct;151(3):619-29

Biochemistry Department, University of Geneva, 1211 Geneva, Switzerland.

The GTPase dynamin polymerizes into a helical coat that constricts membrane necks of endocytic pits to promote their fission. However, the dynamin mechanism is still debated because constriction is necessary but not sufficient for fission. Here, we show that fission occurs at the interface between the dynamin coat and the uncoated membrane. At this location, the considerable change in membrane curvature increases the local membrane elastic energy, reducing the energy barrier for fission. Fission kinetics depends on tension, bending rigidity, and the dynamin constriction torque. Indeed, we experimentally find that the fission rate depends on membrane tension in vitro and during endocytosis in vivo. By estimating the energy barrier from the increased elastic energy at the edge of dynamin and measuring the dynamin torque, we show that the mechanical energy spent on dynamin constriction can reduce the energy barrier for fission sufficiently to promote spontaneous fission. :
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http://dx.doi.org/10.1016/j.cell.2012.09.017DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4290832PMC
October 2012

Totally implanted venous access devices implanted in the saphenous vein. Relation between the reservoir site and comfort/discomfort of the patients.

Ann Vasc Surg 2012 Nov 28;26(8):1127.e9-1127.e13. Epub 2012 Aug 28.

Department of Surgical Sciences, Organ Transplantation, and Advanced Technologies, Cannizzaro Hospital, University of Catania, Catania, Italy.

Background: When a totally implantable venous access device (TIVAD) is implanted in the femoral or saphenous vein, the port can be placed in the abdominal wall, thigh, or anteroinferior thoracic wall. This study analyzed the relationship between the position of the port and patient comfort.

Methods: All patients who underwent TIVAD implantation from 1995 to 2011 were included in the study. Sex, age, indication for TIVAD implantation, contraindication for implantation in a vein draining into the superior vena cava, surgical technique, length of procedure, complications, difficulties recorded by nurses, and patient comfort or discomfort were recorded.

Results: The TIVAD was implanted in the saphenous vein in 6 of 581 patients (1.3%) who received a TIVAD, consisting of four male subjects and two female subjects aged 35 to 56 years (mean age: 47.3 years), who all underwent TIVAD implantation for the treatment of a solid tumor. The port was positioned in the anteroinferior thoracic wall in one patient, the abdominal wall in one patient, the anterior thigh in three patients, and the lateral thigh in one patient. The mean procedure duration was 52 minutes (range: 20-135 minutes). No immediate or early complications were recorded. The nurses had difficulty in puncturing the port in the abdominal wall. Patient comfort levels were high when the port was placed in the anterior thigh.

Conclusion: The anterior thigh may be the most useful and comfortable position for the port of a TIVAD implanted in the inferior vena cava. Larger studies should be undertaken to confirm this.
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http://dx.doi.org/10.1016/j.avsg.2012.02.025DOI Listing
November 2012

Comparison of two entry methods for laparoscopic port entry: technical point of view.

Diagn Ther Endosc 2012 13;2012:305428. Epub 2012 Jun 13.

Department of Surgical Sciences, Organ Transplantation, and Advanced Technologies, University of Catania, Cannizzaro Hospital, Via Messina 829, 95126 Catania, Italy.

Laparoscopic entry is a blind procedure and it often represents a problem for all the related complications. In the last three decades, rapid advances in laparoscopic surgery have made it an invaluable part of general surgery, but there remains no clear consensus on an optimal method of entry into the peritoneal cavity. The aim of this paper is to focus on the evolution of two used methods of entry into the peritoneal cavity in laparoscopic surgery.
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http://dx.doi.org/10.1155/2012/305428DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3384909PMC
August 2012

Persistent increase in alpha-fetoprotein level in a patient without underlying liver disease who underwent curative resection of hepatocellular carcinoma. A case report and review of the literature.

World J Surg Oncol 2012 May 6;10:79. Epub 2012 May 6.

Department of Surgical Sciences, Organ Transplantation and Advanced Technologies, University of Catania, Cannizzaro Hospital, Catania, Italy.

Introduction: Alpha-fetoprotein (AFP) is an oncofetal protein produced by hepatocellular carcinoma (HCC). AFP level can also be elevated in other neoplastic or non-neoplastic conditions. An elevated AFP level has high diagnostic significance for HCC; at a level of >200 ng/mL, the probability of HCC is >90%. The aim of the present paper is to report a patient who underwent curative resection of HCC, who had a persistently elevated AFP level postoperatively but did not develop recurrence during a 2-year follow-up period. A review of the literature is also presented.

Case Report: An 82-year-old male was referred following a computed tomography scan showing a 160 mm diameter mass in the left lobe of the liver. This huge mass was diagnosed as HCC, arising in the absence of cirrhosis or viral hepatitis. After tumor removal, the patient's high AFP level persisted for 2 years.

Conclusion: As steatosis was the only pathological change in the remnant liver, this may have caused the persistently elevated AFP level in this patient.
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http://dx.doi.org/10.1186/1477-7819-10-79DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3407768PMC
May 2012

Stress clamp experiments on multicellular tumor spheroids.

Phys Rev Lett 2011 Oct 24;107(18):188102. Epub 2011 Oct 24.

UMR 168, Institut Curie, Centre de Recherche, 26 rue d'Ulm 75005 Paris, France.

The precise role of the microenvironment on tumor growth is poorly understood. Whereas the tumor is in constant competition with the surrounding tissue, little is known about the mechanics of this interaction. Using a novel experimental procedure, we study quantitatively the effect of an applied mechanical stress on the long-term growth of a spheroid cell aggregate. We observe that a stress of 10 kPa is sufficient to drastically reduce growth by inhibition of cell proliferation mainly in the core of the spheroid. We compare the results to a simple numerical model developed to describe the role of mechanics in cancer progression.
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http://dx.doi.org/10.1103/PhysRevLett.107.188102DOI Listing
October 2011

Quantum dots to tail single bio-molecules inside living cells.

Adv Drug Deliv Rev 2012 Feb 24;64(2):167-78. Epub 2011 Jun 24.

In the last two decades, the single particle and single molecule approach became more and more popular to investigate the activity and the mechano-chemical properties of biological molecules. The inherent limit of these assays was that the molecules of interest were observed in vitro, out of their natural environment, the cell. Several recent works have shown the possibility to overcome this limit, to extend this approach to living cells and to observe the details of many cellular processes at the molecular level. In this review we discuss the use of semiconductor quantum dots to perform single particle and single molecule tracking in the cell. We refer to other articles for the technical aspects of this method. Here, after an introduction on the advantages provided by these nanoparticles, we restrict ourselves to some examples, mainly related to intracellular transport and molecular motor activity. These will illustrate the important role played by semiconductor quantum dots as fluorescent nano-reporters in in cell single molecule approach in modern biology and biophysics.
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http://dx.doi.org/10.1016/j.addr.2011.06.004DOI Listing
February 2012

Separation of time scales in one-dimensional directed nucleation-growth processes.

Phys Rev E Stat Nonlin Soft Matter Phys 2010 Dec 9;82(6 Pt 1):061904. Epub 2010 Dec 9.

Institut Curie, Centre de recherche, INSERM U932 Immunité et cancer, 12 rue Lhomond, 75005 Paris, France.

Proteins involved in homologous recombination such as RecA and hRad51 polymerize on single- and double-stranded DNA according to a nucleation-growth kinetics, which can be monitored by single-molecule in vitro assays. The basic models currently used to extract biochemical rates rely on ensemble averages and are typically based on an underlying process of bidirectional polymerization, in contrast with the often observed anisotropic polymerization of similar proteins. For these reasons, if one considers single-molecule experiments, the available models are useful to understand observations only in some regimes. In particular, recent experiments have highlighted a steplike polymerization kinetics. The classical model of one-dimensional nucleation growth, the Kolmogorov-Avrami-Mehl-Johnson (KAMJ) model, predicts the correct polymerization kinetics only in some regimes and fails to predict the steplike behavior. This work illustrates by simulations and analytical arguments the limitation of applicability of the KAMJ description and proposes a minimal model for the statistics of the steps based on the so-called stick-breaking stochastic process. We argue that this insight might be useful to extract information on the time and length scales involved in the polymerization kinetics.
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http://dx.doi.org/10.1103/PhysRevE.82.061904DOI Listing
December 2010