Aqueous Synthesis of Plasmonic Gold-Tin Alloy Nanoparticles.

This protocol describes the synthesis of Au nanoparticle seeds and the subsequent formation of Au-Sn bimetallic nanoparticles. These nanoparticles have potential applications in catalysis, optoelectronics, imaging, and drug delivery. Previously, methods for producing alloy nanoparticles have been time-consuming, require complex reaction conditions, and can have inconsistent results. The outlined protocol first describes the synthesis of approximately 13 nm Au nanoparticle seeds using the Turkevich method. The protocol next describes the reduction of Sn and its incorporation into the Au seeds to generate Au-Sn alloy nanoparticles. The optical and structural characterization of these nanoparticles is described. Optically, prominent localized surface plasmon resonances (LSPRs) are apparent using UV-visible spectroscopy. Structurally, powder X-ray diffraction (XRD) reflects all particles to be less than 20 nm and shows patterns for Au, Sn, and multiple Au-Sn intermetallic phases. Spherical morphology and size distribution are obtained from transmission electron microscopy (TEM) imaging. TEM reveals that after Sn incorporation, the nanoparticles grow to approximately 15 nm in diameter.

Deacylcortivazol-like pyrazole regioisomers reveal a more accommodating expanded binding pocket for the glucocorticoid receptor.

Glucocorticoids (GCs) are widely used, potent anti-inflammatory and chemotherapeutic drugs. They work by binding to the glucocorticoid receptor (GR), a ligand-activated transcription factor, inducing translocation to the nucleus and regulation of genes that influence a variety of cellular activities. Despite being effective for a broad number of conditions, GC use is limited by severe side effects. To identify ligands that are more selective, we synthesized pairs of regioisomers in the pyrazole ring that probe the expanded binding pocket of GR opened by deacylcortivazol (DAC). Using an Ullmann-type reaction, a deacylcortivazol-like (DAC-like) backbone was modified with five pendant groups at the 1'- and 2'-positions of the pyrazole ring, yielding 9 ligands. Most of the compounds were cytotoxic to leukemia cells, and all required GR expression. Both aliphatic and other aromatic groups substituted at the 2'-position produced ligands with GC activity, with phenyl and 4-fluorophenyl substitutions exhibiting high cellular affinity for the receptor and >5× greater potency than dexamethasone, a commonly used strong GC. Surprisingly, phenyl substitution at the 1'-position produced a high-affinity ligand with ∼10× greater potency than dexamethasone, despite little apparent room in the expanded binding pocket to accommodate 1'-modifications. Other 1'-modifications, however, were markedly less potent. The potency of the 2'-substituted and 1'-substituted DAC-like compounds tracked linearly with cellular affinity but had different slopes, suggesting a different mode of interaction with GR. These data provide evidence that the expanded binding pocket opened by deacylcortivazol is more accommodating that expected, allowing development of new, and possibly selective, GCs by substitution within the pyrazole ring.

Assessment of collagen-induced arthritis using cyanine 5.5 conjugated with hydrophobically modified glycol chitosan nanoparticles: correlation with 18F-fluorodeoxyglucose positron emission tomography data.

OBJECTIVE: To evaluate the potential and correlation between near-infrared fluorescence (NIRF) imaging using cyanine 5.5 conjugated with hydrophobically modified glycol chitosan nanoparticles (HGC-Cy5.5) and (18)F-fluorodeoxyglucose-positron emission tomography ((18)F-FDG-PET) imaging of collagen-induced arthritis (CIA). MATERIALS AND METHODS: We used 10 CIA and 3 normal mice. Nine days after the injecting collagen twice, microPET imaging was performed 40 minutes after the intravenous injection of 9.3 MBq (18)F-FDG in 200 µL PBS. One day later, NIRF imaging was performed two hours after the intravenous injection of HGC-cy5.5 (5 mg/kg). We assessed the correlation between these two modalities in the knees and ankles of CIA mice. RESULTS: The mean standardized uptake values of (18)F-FDG for knees and ankles were 1.68 ± 0.76 and 0.79 ± 0.71, respectively, for CIA mice; and 0.57 ± 0.17 and 0.54 ± 0.20 respectively for control mice. From the NIRF images, the total photon counts per 30 mm(2) for knees and ankles were 2.32 ± 1.54 × 10(5) and 2.75 ± 1.51 × 10(5), respectively, for CIA mice, and 1.22 ± 0.27 × 10(5) and 0.88 ± 0.24 × 10(5), respectively, for control mice. These two modalities showed a moderate correlation for knees (r = 0.604, p = 0.005) and ankles (r = 0.464, p = 0.039). Moreover, both HGC-Cy5.5 (p = 0.002) and (18)F-FDG-PET (p = 0.005) imaging also showed statistically significant differences between CIA and normal mice. CONCLUSION: NIRF imaging using HGC-Cy5.5 was moderately correlated with (18)F-FDG-PET imaging in the CIA model. As such, HGC-Cy5.5 imaging can be used for the early detection of rheumatoid arthritis.

Locally advanced thyroid cancer: can CT help in prediction of extrathyroidal invasion to adjacent structures?

OBJECTIVE: The purpose of this study was to determine the diagnostic accuracy of CT for detecting extrathyroidal invasion of thyroid cancer to adjacent structures. MATERIALS AND METHODS: Eighty-four patients (19 men, 65 women; age range, 19-84 years; mean, 54.2 +/- 15.4 years) with 86 malignant tumors of the thyroid with extracapsular extension (37 T3, 49 T4) were retrospectively enrolled in this study. Two radiologists independently evaluated the CT findings of invasion of thyroid cancer into the trachea, esophagus, common carotid artery, internal jugular vein, and recurrent laryngeal nerve. These results were compared with the surgical and histopathologic findings. RESULTS: The mean sensitivity, specificity, and accuracy of CT were as follows: 59.1%, 91.4%, and 83.2% for tracheal invasion; 28.6%, 96.2%, and 90.7% for esophageal invasion; 75.0%, 99.4%, and 98.8% for invasion of the common carotid artery; 33.3%, 98.8%, and 97.1% for invasion of the internal jugular vein; and 78.2%, 89.8%, and 85.5% for invasion to the recurrent laryngeal nerve. Interobserver agreement was moderate to good in the five categories of extrathyroidal invasion with a mean kappa value of 0.65 (range, 0.49-0.77). CONCLUSION: Although the effectiveness is limited by low sensitivity, CT may be a valuable tool for evaluation of extrathyroidal invasion of thyroid cancer to adjacent structures.

CT features of foreign body granulomas after cosmetic paraffin injection into the cervicofacial area.

PURPOSE: Cosmetic injection of paraffin into cervicofacial tissues has been practiced in the past, especially in Asia, resulting in foreign body granuloma (paraffinoma). The purpose of this study was to describe the computed tomography (CT) findings of cervicofacial paraffinomas. MATERIALS AND METHODS: CT images of 5 patients (4 women and 1 man; age range, 54-80 years; mean age, 67.6 years), who had received direct paraffin injections into cervicofacial tissues, were reviewed retrospectively. RESULTS: The lesions were bilateral and located in the subcutaneous fat layer of the cheek (n = 5), buccal space (n = 2), periorbital area (n = 1), periauricular area (n = 1), neck (n = 1), and nose (n = 1). The predominant CT features were speckled mass formation (n = 3), fat-density nodule (n = 5), high-density nodule (n = 5), nodular calcification (n = 5), and rim calcification (n = 4). CONCLUSION: Paraffinomas in the cervicofacial region have specific CT features that are distinct from other soft tissue masses.

Angiomyofibroblastoma arising from the posterior perivesical space: a case report with MR findings.

Angiomyofibroblastoma is a rare benign soft tissue neoplasm that predominantly occurs in the genital region of middle-aged women. We present a case of an angiomyofibroblastoma that involved the posterior perivesical space in a 48-year-old woman. We have documented the magnetic resonance imaging features of this case.

Relationship between mucoid hypertrophy of the anterior cruciate ligament (ACL) and morphologic change of the intercondylar notch: MRI and arthroscopy correlation.

OBJECTIVE: The purpose of this study was to evaluate the relationship between mucoid hypertrophy of the anterior cruciate ligament (ACL) and morphologic change of the intercondylar notch. MATERIALS AND METHODS: We retrospectively reviewed the 105 patients with knee magnetic resonance imaging (MRI) with or without knee arthroscopy [group 1: patients with arthroscopic notchplasty (N = 47), group 2: knee arthroscopy demonstrating intact ACL (N = 33), and group 3: patients with normal knee MRI but no arthroscopy (N = 25)]. Groups 2 and 3 served as an arthroscopic and MR control group, respectively. Two musculoskeletal radiologists reviewed all MR examinations. The intercondylar notch width, notch index (width of intercondylar notch/width of femoral condyle), transverse notch angle (TNA), sagittal notch angle (SNA), and notch area were recorded on axial and sagittal MR images at the midpoint of Blumensaat's line which was identified on sagittal images. The diameter of the ACL was recorded on coronal MR images at the posterior end of Blumensaat's line. RESULTS: The mean values of the intercondylar notch width, notch index, TNA, SNA, notch area, and ACL diameter for the three groups were 16.0 mm/0.2/50.3 degrees /36.5 degrees /249.0 mm(2)/7.7 mm (group 1); 19.3 mm/0.3/52.9 degrees /40.2 degrees /323.4 mm(2)/4.8 mm (group 2); and 20.3 mm/0.3/51.4 degrees /39.1 degrees /350.8 mm(2)/4.5 mm (group 3). The intercondylar notch width, notch index, SNA, and notch area were smaller, and ACL diameter was thicker in group 1 compared with the other groups (p < 0.05). CONCLUSION: Patients with mucoid ACL hypertrophy show a narrower notch, a steeper notch angle, and a smaller notch area than control groups.