Rationale And Objectives: To assess the applicability of a novel macromolecular polyethylene glycol (PEG)-core gadolinium contrast agent for monitoring early antiangiogenic effects of bevacizumab using dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI).
Materials And Methods: Athymic rats (n = 26) implanted with subcutaneous human melanoma xenografts underwent DCE-MRI at 2.0 T using two different macromolecular contrast agents. The PEG core cascade polymer PEG12,000-Gen4-(Gd-DOTA)16, designed for clinical development, was compared to the prototype, animal-only, macromolecular contrast medium (MMCM) albumin-(Gd-DTPA)35. The treatment (n = 13) and control (n = 13) group was imaged at baseline and 24 hours after a single dose of bevacizumab (1 mg) or saline to quantitatively assess the endothelial-surface permeability constant (K(PS), μL⋅min⋅100 cm(3)) and the fractional plasma volume (fPV,%), using a two-compartment kinetic model.
Results: Mean K(PS) values, assessed with PEG12,000-Gen4-(Gd-DOTA)16, declined significantly (P < .05) from 29.5 ± 10 μL⋅min⋅100 cm(3) to 10.4 ± 7.8 μL⋅min⋅100 cm(3) by 24 hours after a single dose of bevacizumab. In parallel, K(PS) values quantified using the prototype MMCM albumin-(Gd-DTPA)35 showed an analogous, significant decline (P < .05) in the therapy group. No significant effects were detected on tumor vascularity or on microcirculatory parameters in the control group between the baseline and the follow-up scan at 24 hours.
Conclusion: DCE-MRI enhanced with the novel MMCM PEG12,000-Gen4-(Gd-DOTA)16 was able to monitor the effects of bevacizumab on melanoma xenografts within 24 hours of a single application, validated by the prototype, animal-only albumin-(Gd-DTPA)35. PEG12,000-Gen4-(Gd-DOTA)16 may be a promising candidate for further clinical development as a macromolecular blood pool contrast MRI agent.
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http://dx.doi.org/10.1016/j.acra.2013.07.010 | DOI Listing |
Sci Rep
December 2024
School of Mechanical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353, China.
Microtextured microneedles are tiny needle-like structures with micron-scale microtextures, and the drugs stored in the microtextures can be released after entering the skin to achieve the effect of precise drug delivery. In this study, the skin substitution model of Ogden's hyperelastic model and the microneedle array and microtexture models with different geometrical parameters were selected to simulate and analyse the flow of the microtexture microneedle arrays penetrating the skin by the finite-element method, and the length of the microneedles was determined to be 200 μm, the width 160 μm, and the value of the gaps was determined to be 420 μm. A four-pronged cone was chosen as the shape of microneedles, and a rectangle was chosen as the shape of the drug-carrying microneedle.
View Article and Find Full Text PDFTrials
December 2024
Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.
Background: Vancomycin, an antibiotic with activity against methicillin-resistant Staphylococcus aureus (MRSA), is frequently included in empiric treatment for community-acquired pneumonia (CAP) despite the fact that MRSA is rarely implicated in CAP. Conducting polymerase chain reaction (PCR) testing on nasal swabs to identify the presence of MRSA colonization has been proposed as an antimicrobial stewardship intervention to reduce the use of vancomycin. Observational studies have shown reductions in vancomycin use after implementation of MRSA colonization testing, and this approach has been adopted by CAP guidelines.
View Article and Find Full Text PDFWorld Neurosurg
December 2024
Department of Neurology, Nanjing Pukou People's Hospital, No. 166 Shanghe Street, Jiangpu Subdistrict, Pukou District, Nanjing, 210000, China. Electronic address:
Objective: Early identification of risk factors associated with early neurological deterioration (END) in patients with acute minor stroke and large vessel occlusion (LVO) receiving intravenous thrombolysis (IVT) could assist in formulating treatment decisions.
Methods: Consecutive patients with acute minor stroke and LVO were extracted from a single-center prospective database spanning January 2020 to December 2023. END was defined as an increase of ≥ 4 points in the National Institutes of Health Stroke Scale (NIHSS) score from baseline, or ≥ 2 points in any single NIHSS item, within 24 hours of the IVT.
J Nutr
December 2024
Nottingham NIHR Biomedical Research Centre and Nottingham Digestive Disease Centre, School of Medicine, University of Nottingham, Nottingham, United Kingdom. Electronic address:
Background: Recent studies show that the increase in breath hydrogen (BH) and symptoms after ingestion of inulin is reduced by co-administering psyllium.
Objectives: To determine if slowing delivery of inulin to the colon by administering it in divided doses would mimic the effect of psyllium. Primary endpoint was the BH area under the curve AUC.
J Cardiothorac Vasc Anesth
December 2024
Department of Cardiovascular Surgery, Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. Electronic address:
Objectives: The myocardial-protective effect of del Nido cardioplegia solution was evaluated in adult patients undergoing prolonged aortic cross-clamping during cardiac surgery.
Design: Prospective cohort.
Setting: Single-center tertiary academic medical center.
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