Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 4 de 4
Filter
Add more filters










Database
Language
Publication year range
1.
IEEE Int Ultrason Symp ; 2019: 2303-2306, 2019 Oct.
Article in English | MEDLINE | ID: mdl-36514673

ABSTRACT

The purpose of this study was to monitor acute changes in pancreatic tumor perfusion with contrast-enhanced ultrasound (CEUS) imaging following targeted hyaluronan (HA) treatment. Intratumoral accumulation of HA is one of contributing factors that can lead to an increased tumor interstitial pressure (TIP). These elevated TIP levels can hinder delivery of chemotherapeutic drugs and cause treatment failure. For this study, pancreatic cancer-bearing mice were imaged at baseline and again at 2 h after intravenous administration of physiological saline (control group) or PEGPH20, which targets HA (therapy group). CEUS data were collected for 5 min and the temporal sequence was first analyzed using a singular value filter (SVF) to remove any background clutter signal. Given the time history of contrast agent flow, a tumor perfusion parametric analysis was performed. A series of morphological image operations was applied to quantify structural features of the tumor angiogenic network including vessel count, density, length, diameter, tortuosity, and branching points. After imaging, animals were euthanized, and tumors excised for histological processing. Acute microvascular changes were found at 2 h after drug administration as confirmed by CEUS imaging. Further, histologic analysis of tumor sections revealed lower HA accumulation in the therapy group animals. Overall, these findings suggest that CEUS imaging of acute changes in tumor perfusion may help identify an optimal window whereby follow-up chemotherapeutic drug dosing would be more effective.

2.
J Ultrasound Med ; 38(5): 1259-1268, 2019 May.
Article in English | MEDLINE | ID: mdl-30280391

ABSTRACT

OBJECTIVE: H-scan imaging is a new ultrasound technique used to visualize the relative size of acoustic scatterers. The purpose of this study was to evaluate the use of H-scan ultrasound imaging for monitoring early tumor response to neoadjuvant treatment using a preclinical breast cancer animal model. METHODS: Real-time H-scan ultrasound imaging was implemented on a programmable ultrasound scanner (Vantage 256; Verasonics Inc., Kirkland, WA) equipped with an L11-4v transducer. Bioluminescence and H-scan ultrasound was used to image luciferase-positive breast cancer-bearing mice at baseline and at 24, 48, and 168 hours after administration of a single dose of neoadjuvant (paclitaxel) or sham treatment. Animals were euthanized at 48 or 168 hours, and tumors underwent histologic processing to identify cancer cell proliferation and apoptosis. RESULTS: Baseline H-scan ultrasound images of control and therapy group tumors were comparable, but the latter exhibited significant changes over the 7-day study (P < .05). At termination, there was a marked difference between the H-scan ultrasound images of control and treated tumors (P < .05). Specifically, H-scan ultrasound images of treated tumors were more blue in hue than images obtained from control tumors. There was a significant linear correlation between the predominance of the blue hue found in the H-scan ultrasound images and intratumoral apoptotic activity (R2 > 0.40, P < .04). CONCLUSION: Preliminary preclinical results suggest that H-scan ultrasound imaging is a new and promising tissue characterization modality. H-scan ultrasound imaging may provide prognostic value when monitoring early tumor response to neoadjuvant treatment.


Subject(s)
Antineoplastic Agents, Phytogenic/therapeutic use , Breast Neoplasms/diagnostic imaging , Breast Neoplasms/drug therapy , Neoadjuvant Therapy/methods , Paclitaxel/therapeutic use , Ultrasonography/methods , Animals , Disease Models, Animal , Female , Mice , Mice, Nude , Phantoms, Imaging , Treatment Outcome
3.
Steroids ; 128: 15-22, 2017 12.
Article in English | MEDLINE | ID: mdl-29037584

ABSTRACT

Derivatives of spironolactone (1), a diuretic and antihypertensive drug, were synthesized by using fungal cells for the first time. Ten different fungi were screened for their ability to biotransform 1, four of which were able to produce metabolites 2-8. Gibberella fujikuroi produced canrenone (2), 1-dehydrocanrenone (3), Curvularia lunuta provided compound 2, and 7α-thio-spironolactone (4), Fusarium lini yielded compounds 2, 3, 1ß-hydroxycanrenone (5), 1α-hydroxycanrenone (6), 1-dehydro-15α-hydroxycanrenone (7), and 15α-hydroxycanrenone (8), while Aspergillus alliaceus was able to produce all the seven metabolites. Metabolites 5, 6, and 7 were identified as new compounds. Their structures were elucidated by using different spectroscopic techniques. Substrate 1 and its metabolites 2, 3, and 5-8 were also evaluated for α-glucosidase inhibitory activity in vitro. Substrate 1 was found to be strongly active with IC50 = 335 ±â€¯4.3 µM as compared to the standard drug acarbose IC50 = 840 ±â€¯1.73 µM, whereas all of resulting metabolites were found to be inactive.


Subject(s)
Antihypertensive Agents/chemical synthesis , Biotransformation , Diuretics/chemical synthesis , Spironolactone/chemical synthesis , Antihypertensive Agents/chemistry , Antihypertensive Agents/therapeutic use , Ascomycota/chemistry , Ascomycota/genetics , Ascomycota/metabolism , Aspergillus/chemistry , Aspergillus/genetics , Aspergillus/metabolism , Diuretics/chemistry , Diuretics/therapeutic use , Fusarium/chemistry , Fusarium/genetics , Fusarium/metabolism , Gibberella/chemistry , Gibberella/genetics , Gibberella/metabolism , Humans , Molecular Structure , Spironolactone/analogs & derivatives , Spironolactone/chemistry , Spironolactone/therapeutic use
4.
Bioorg Med Chem ; 23(20): 6740-8, 2015 Oct 15.
Article in English | MEDLINE | ID: mdl-26381063

ABSTRACT

We describe here the synthesis of dihydropyrimidines derivatives 3a-p, and evaluation of their α-glucosidase enzyme inhibition activities. Compounds 3b (IC50=62.4±1.5 µM), 3c (IC50=25.3±1.26 µM), 3d (IC50=12.4±0.15 µM), 3e (IC50=22.9±0.25 µM), 3g (IC50=23.8±0.17 µM), 3h (IC50=163.3±5.1 µM), 3i (IC50=30.6±0.6 µM), 3m (IC50=26.4±0.34 µM), and 3o (IC50=136.1±6.63 µM) were found to be potent α-glucosidase inhibitors in comparison to the standard drug acarbose (IC50=840±1.73 µM). The compounds were also evaluated for their in vitro cytotoxic activity against PC-3, HeLa, and MCF-3 cancer cell lines, and 3T3 mouse fibroblast cell line. All compounds were found to be non cytotoxic, except compounds 3f and 3m (IC50=17.79±0.66-20.44±0.30 µM), which showed a weak cytotoxic activity against the HeLa, and 3T3 cell lines. In molecular docking simulation study, all the compounds were docked into the active site of the predicted homology model of α-glucosidase enzyme. From the docking result, it was observed that most of the synthesized compounds showed interaction through carbonyl oxygen atom and polar phenyl ring with active site residues of the enzyme.


Subject(s)
Antineoplastic Agents/pharmacology , Computer Simulation , Glycoside Hydrolase Inhibitors/pharmacology , Pyrimidines/pharmacology , alpha-Glucosidases/metabolism , 3T3 Cells , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Glycoside Hydrolase Inhibitors/chemical synthesis , Glycoside Hydrolase Inhibitors/chemistry , HeLa Cells , Humans , MCF-7 Cells , Mice , Molecular Docking Simulation , Molecular Structure , Pyrimidines/chemical synthesis , Pyrimidines/chemistry , Structure-Activity Relationship , Tumor Cells, Cultured
SELECTION OF CITATIONS
SEARCH DETAIL
...