Imaging of lesions in a murine rheumatoid arthritis model with a humanized anti-interleukin-6 receptor antibody

Gynaecological Cancer Diagnostics: 99mTc-Cisplatin Complex as a Future Approach for Early, Prompt and Efficient Diagnosis of Gynaecological Cancer

BACKGROUND

Gynaecological cancers (GCCa) are common and have a significant mortality rate all over the world. Early diagnosis of cancer can play a key role in the treatment and survival of a patient. Identification, staging, treatment, and monitoring of gynaecological malignancies is being done successfully by nuclear medicines.

DISCUSSION

Currently, single-photon emission computed tomography (SPECT) and positron emission tomography (PET) centered imaging techniques are being developed for use in patients with GCCa as a diagnostic tool. The present work elucidates several clinical studies on the use of radiopharmaceuticals, based on their effectiveness, in the early detection and management of GCCa. It also highlights the importance of reconsidering the biology for nuclear imaging as a future modality for early, rapid and efficient diagnosis of gynecological cancers. This comprehensive review is a part of our study designed to detect gynaecological cancers at an early stage using radionuclide complex, 99m Tc-Cisplatin.

CONCLUSION

This article summarizes the significance of radioscintigraphy such as single-photon emission computed tomography (SPECT) and PET for identification of GCCa in the experimental humans and animals.

Nuclear medicine for imaging of epithelial ovarian cancer

Cancer is one of the leading causes of mortality worldwide. Usually, the diagnosis of cancer at an early stage is important to facilitate proper treatment and survival. Nuclear medicine has been successfully used in the diagnosis, staging, therapy and monitoring of cancers. Single-photon emission computed tomography and PET-based companion imaging agents are in development for use as a companion diagnostic tool for patients with ovarian cancer. The present review discusses the basic and clinical studies related to the use of radiopharmaceuticals in the diagnosis and management of ovarian cancer, focusing on their utility and comparing them with other imaging techniques such as computed tomography and MRI.

Molecular imaging of rheumatoid arthritis: emerging markers, tools, and techniques

Early diagnosis and effective monitoring of rheumatoid arthritis (RA) are important for a positive outcome. Instant treatment often results in faster reduction of inflammation and, as a consequence, less structural damage. Anatomical imaging techniques have been in use for a long time, facilitating diagnosis and monitoring of RA. However, mere imaging of anatomical structures provides little information on the processes preceding changes in synovial tissue, cartilage, and bone. Molecular imaging might facilitate more effective diagnosis and monitoring in addition to providing new information on the disease pathogenesis. A limiting factor in the development of new molecular imaging techniques is the availability of suitable probes. Here, we review which cells and molecules can be targeted in the RA joint and discuss the advances that have been made in imaging of arthritis with a focus on such molecular targets as folate receptor, F4/80, macrophage mannose receptor, E-selectin, intercellular adhesion molecule-1, phosphatidylserine, and matrix metalloproteinases. In addition, we discuss a new tool that is being introduced in the field, namely the use of nanobodies as tracers. Finally, we describe additional molecules displaying specific features in joint inflammation and propose these as potential new molecular imaging targets, more specifically receptor activator of nuclear factor κB and its ligand, chemokine receptors, vascular cell adhesion molecule-1, αVβ₃ integrin, P2X7 receptor, suppression of tumorigenicity 2, dendritic cell-specific transmembrane protein, and osteoclast-stimulatory transmembrane protein.

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.

Tissue factor detection for selectively discriminating unstable plaques in an atherosclerotic rabbit model

Tissue factor (TF), a transmembrane glycoprotein that acts as an essential cofactor to factor VII/VIIa, initiates the exogenous blood coagulation cascade leading to thrombin generation and subsequent thrombus formation in vivo. TF expression is closely related to plaque vulnerability, and high TF expression is shown in macrophage-rich atheromatous lesions, making TF a potential target for detecting atheromatous lesions in vivo. Thus, we prepared (99m)Tc-labeled anti-TF-monoclonal antibody (TF-mAb) IgG as a molecular probe and evaluated its usefulness to achieve TF-specific imaging using myocardial infarction-prone Watanabe heritable hyperlipidemic (WHHLMI) rabbits.

METHODS

Anti-TF-mAb was created using a standard hybridoma technique and was labeled by (99m)Tc with 6-hydrazinonicotinic acid (HYNIC) as a chelating agent to obtain (99m)Tc-TF-mAb. The immunoreactivity of HYNIC-TF-mAb was estimated by flow cytometry. WHHLMI and control rabbits were injected intravenously with (99m)Tc-TF-mAb. Twenty-four hours after the injection, the aorta was removed and radioactivity was measured. Autoradiography and histologic studies were performed using serial aorta sections. Subclass matched antibody (IgG(1)) was used as a negative control.

RESULTS

HYNIC-TF-mAb showed 93% immunoreactivity of the anti-TF-mAb. The radioactivity accumulation in WHHLMI aortas was 6.1-fold higher than that of control rabbits. Autoradiograms showed a heterogeneous distribution of radioactivity in the intima of WHHLMI aortas. Regional radioactivity accumulation was positively correlated with TF expression density (R = 0.64, P < 0.0001). The highest radioactivity accumulation in percentage injected dose × body weight/mm(2) × 10(2) was found in atheromatous lesions (5.2 ± 1.9) followed by fibroatheromatous (2.1 ± 0.7), collagen-rich (1.8 ± 0.7), and neointimal lesions (1.8 ± 0.6). In contrast, (99m)Tc-IgG(1) showed low radioactivity accumulation in WHHLMI aortas that was independent of the histologic grade of lesions.

CONCLUSION

The TF-detecting ability and preferential accumulation in atheromatous lesions of (99m)Tc-TF-mAb were demonstrated, indicating its potential for selective imaging of macrophage-rich atheromatous lesions in vivo.

[Molecular imaging: future uses in arthritides]

Molecular imaging is an upcoming field in radiology as a result of great advances in imaging technology, genetics, and biochemistry in the recent past. Early-stage imaging of molecular pathological changes in cells opens the gates to new methods in medical treatment of diseases that otherwise would only be detected in advanced stages. Methods of imaging biochemical pathways with molecular agents are currently an issue of intensive research. This article reviews current modalities of molecular imaging in arthritis that should offer future perspective on early disease detection, diagnosis, and monitoring of treatment efficiency and how they can pave the way to optimized therapy.