New Concepts for Assessing Global Organ Function and Disease Activity Based on Combined PET and Structural Imaging Techniques.

This review is intended to discuss ways in which global and regional organ function may be assessed by using modern tomographic imaging methods. In addition, we discuss using (18)F-Fluorodeoxyglucose (FDG)-PET to monitor treatment response in various tumors as well as quantification of tumor burden in the entire body. We have selected FDG as a model that can also be adopted for other PET radiotracers.

Clinical and Research Applications of Quantitative PET Imaging.

In recent years, three important quantitative concepts in PET analysis have been developed: partial volume correction of standardized uptake value (SUV) in small lesions, dual-time point and delayed PET imaging, and assessment of global metabolic activity in the whole organ or of a particular diseased tissue(s). In this article, we discuss these novel concepts, their advantages over current quantitative techniques, and their potential clinical applications. We also describe the complicated kinetic modeling and the conventional SUV methods that have been used in the practice of clinical PET.

Potential clinical role of fluorodeoxyglucose-positron emission tomography in assessing primary or secondary lymphomas of the parotid gland.

Background: We have reviewed the utility of fluorodeoxyglucose-positron emission tomography (FDG-PET) imaging for clinical management of primary parotid lymphoma (by applying strict criteria of primary extranodal involvement by this disease) as well as of cases in which spread of the disease to the parotid gland had occurred as a consequence of primary nodal disease.

Patients And Methods: A total of 9 cases of parotid lymphoma (5 primary parotid lymphoma and 4 cases of combined nodal/extranodal lymphoma with parotid involvement) were identified and analyzed for this study. A retrospective review of the clinical records, radiologic data, and pathology results was carried out for assessment of the natural course and FDG-PET results in this disease.

Mycobacterium tuberculosis secreted antigen (MTSA-10) modulates macrophage function by redox regulation of phosphatases.

Macrophages are the primary host cells for Mycobacterium tuberculosis (Mtb). Although macrophages can mount a strong inflammatory response to dispose of invading microbial pathogens, the immune dysfunction of the Mtb-infected macrophage constitutes the hallmark of mycobacterial pathogenesis. A 10-kDa, Mtb secretory antigen (MTSA-10), encoded by ORF Rv3874, is one of the predominant members of the 'region of difference 1' locus of Mtb genome that has been strongly implicated in mycobacterial virulence.

"Cold" vertebrae on F-18 FDG PET: Causes and characteristics.

Background: Photon deficiency in the vertebrae on FDG PET can arise as a result of varying etiologies, and a proper interpretation of this incidental observation is essential for an accurate diagnosis.

Materials And Methods: Cases with "cold" vertebrae on FDG PET resulting from different causes were selected and analyzed from a population of patients with cancer who underwent conventional whole-body FDG PET for staging, disease viability assessment, or treatment monitoring purposes. The patterns were studied and correlated with the appropriate clinical setting.

Potential clinical role of FDG-PET in detecting sarcomatous transformation in von Recklinghausen's disease: a case study and review of the literature.

Background: The diagnosis of sarcomatous transformation of plexiform neurofibromas in Neurofibromatosis-1 (NF 1) is a clinical and radiological challenge. Considerable overlap exists in the clinical and the radiological characteristics between the benign enlarging neurofibromas and their counterparts undergoing malignant changes. Surgical biopsy to rule out suspicious malignant transformation is often a problem in deep seated lesions.

IL-6 and IL-12 specifically regulate the expression of Rab5 and Rab7 via distinct signaling pathways.

Recent studies have shown that phagosome maturation depends on the balance between pro-inflammatory and anti-inflammatory cytokines, indicating that cytokine modulates phagosome maturation. However, the mechanism of cytokine-mediated modulation of intracellular trafficking remains to be elucidated. Here, we have shown that treatment of macrophages with IL-6 specifically induce the expression of Rab5 through the activation of extracellular signal-regulated kinase, whereas IL-12 exclusively upregulate the expression of Rab7 through the activation of p38 MAPK.

Selected cases demonstrating the value of furosemide-primed 18F-FDG PET in identifying adrenal involvement.

The adrenals are often a site of metastatic spread of cancer, and evaluation of the adrenals is important in assessing the extent of disease involvement in several malignancies. PET with 18F-FDG has been found extremely effective in detecting adrenal involvement not identified on CT or not meeting the CT size criteria for malignancy. However, evaluation of the adrenals and of retroperitoneal adenopathy or other pathologic conditions with 18F-FDG PET can be complicated at times by normal accumulation of the tracer in the uppermost renal calyx because of its somewhat posterior orientation, particularly when it is dilated.

The strength of receptor signaling is centrally controlled through a cooperative loop between Ca2+ and an oxidant signal.

Activation of cell-surface receptors stimulates generation of intracellular signals that, in turn, direct the cellular response. However, mechanisms that ensure combinatorial control of these signaling events are not well understood. We show here that the Ca2+ and reactive oxygen intermediates generated upon BCR activation rapidly engage in a cooperative interaction that acts in a feedback manner to amplify the early signal generated.

(18)FDG PET in primary oat cell carcinoma of the esophagus.

The role of FDG-PET in oat cell carcinoma of the esophagus is hitherto unexplored. A MEDLINE search using the terms "small cell carcinoma" or "oat cell carcinoma" combined with "FDG-PET" yielded no report on this issue till date. We report, in this article, two cases depicting the usefulness of this modality in the management of this uncommon neoplasm.

Unsuspected metastatic male breast nodule from synovial sarcoma detected by FDG PET.

The literature of serendipitous findings on whole-body FDG PET continues to grow. Whole-body FDG PET imaging of a 24-year-old man with treated synovial sarcoma of the right upper extremity showed an abnormal focus of activity over the right chest in addition to abnormal uptake in the lungs. On reexamination, he was found to have a hitherto unknown 2.

Hemoglobin receptor in Leishmania is a hexokinase located in the flagellar pocket.

Hb endocytosis in Leishmania is mediated through a 46-kDa protein located in the flagellar pocket. To understand the nature of the Hb receptor (HbR), we have purified the 46-kDa protein to homogeneity from Leishmania promastigote membrane. Purified HbR specifically binds Hb.