Factors affecting image quality and diagnostic efficacy in abdominal sonography: A prospective study of 140 patients

A study was undertaken to evaluate the limitations of abdominal sonography in a group of predominantly elderly patients. In the majority of patients (98%) sonography, using 3.5 MHz and 5 MHz array transducers permitted visualization of the major abdominal organs with image quality sufficient for definitive diagnosis, but improved image quality would be desirable in 78% of this sample. Obesity and immobilization were associated with poor sonographic image quality. In 31 of the 45 (69%) poor image quality studies, no near-field artifacts (less than 3 cm depth) were observed. Obstacles in the acoustic path were noted in 77% of the poor image quality studies. © 1993 John Wiley & Sons, Inc.     

Ultrasonic attenuation maps of liver based on a conventional B-scan and an amplitude loss technique

The authors present a novel ultrasonic amplitude loss technique, using image processing techniques and designed for computation of local attenuation estimates. Three different estimation approaches were evaluated: the extended Prony, the maximum likelihood, and the least squares approaches. The latter two approaches were found to result in a much higher estimation error than that observed for the Prony method. The attenuation values in the normal population (49 subjects) were 0.44 +/- 0.03 dB/MHz/cm. Three hundred sixty-seven liver scans from 266 patients were evaluated. Hodgkin's lymphoma patients with liver involvement had attenuation values of 0.22 +/- 0.07 dB/MHz/cm. Low attenuation values also were observed for four patients with viral hepatitis (0.31 +/- 0.08 dB/MHz/cm). The detectability of other disease states was not increased by these global attenuation estimates; however, the results demonstrate possible potential uses for the proposed technique for the diagnosis of diffuse liver disease.     

CT features of adnexal torsion

OBJECTIVE: Adnexal torsion is most commonly a clinical diagnosis, often aided by sonographic findings. At times, the clinical presentation can mimic nongynecologic causes of acute lower abdominal pain. In these cases, CT may be the initial imaging study. The purpose of this study was to define the CT features associated with adnexal torsion. CONCLUSION: On CT, a well-defined adnexal mass abnormally located in the pelvis with ipsilateral deviation of the uterus in a woman or girl with lower abdominal pain should raise the suspicion of adnexal torsion. Inflammatory signs on CT suggest the presence of necrosis.     

ApoSense: a novel technology for functional molecular imaging of cell death in models of acute renal tubular necrosis

Purpose Acute renal tubular necrosis (ATN), a common cause of acute renal failure, is a dynamic, rapidly evolving clinical condition associated with apoptotic and necrotic tubular cell death. Its early identification is critical, but current detection methods relying upon clinical assessment, such as kidney biopsy and functional assays, are insufficient. We have developed a family of small molecule compounds, ApoSense, that is capable, upon systemic administration, of selectively targeting and accumulating within apoptotic/necrotic cells and is suitable for attachment of different markers for clinical imaging. The purpose of this study was to test the applicability of these molecules as a diagnostic imaging agent for the detection of renal tubular cell injury following renal ischemia.Methods Using both fluorescent and radiolabeled derivatives of one of the ApoSense compounds, didansyl cystine, we evaluated cell death in three experimental, clinically relevant animal models of ATN: renal ischemia/reperfusion, radiocontrast-induced distal tubular necrosis, and cecal ligature and perforation-induced sepsis.Results ApoSense showed high sensitivity and specificity in targeting injured renal tubular epithelial cells in vivo in all three models used. Uptake of ApoSense in the ischemic kidney was higher than in the non-ischemic one, and the specificity of ApoSense targeting was demonstrated by its localization to regions of apoptotic/necrotic cell death, detected morphologically and by TUNEL staining.Conclusion ApoSense technology should have significant clinical utility for real-time, noninvasive detection of renal parenchymal damage of various types and evaluation of its distribution and magnitude; it may facilitate the assessment of efficacy of therapeutic interventions in a broad spectrum of disease states.M. Damianovich and I. Ziv had an equal contribution to the paper.Potential conflict of interest: ApoSense is a product developed by NST, Ltd. NST financially supported the research presented in full. M. Damianovich, I. Ziv, T. Aloya, H. Grimberg, G. Levin, A. Reshef, A. Bentolila, A. Cohen, and A. Shirvan are NST employees. S.N. Heyman, S. Rosen , A. Shina, and D. Kidron have no actual or potential conflict of interest in relation to this article. ApoSense is still an investigational product.     

MiR-92b and miR-9/9* are specifically expressed in brain primary tumors and can be used to differentiate primary from metastatic brain tumors

A recurring challenge for brain pathologists is to diagnose whether a brain malignancy is a primary tumor or a metastasis from some other tissue. The accurate diagnosis of brain malignancies is essential for selection of proper treatment. MicroRNAs are a class of small non-coding RNA species that regulate gene expression; many exhibit tissue-specific expression and are misregulated in cancer. Using microRNA expression profiling, we found that hsa-miR-92b and hsa-miR-9/hsa-miR-9* are over-expressed, specifically in brain primary tumors, as compared to primary tumors from other tissues and their metastases to the brain. By considering the expression of only these two microRNAs, it is possible to distinguish between primary and metastatic brain tumors with very high accuracy. These microRNAs thus represent excellent biomarkers for brain primary tumors. Previous reports have found that hsa-miR-92b and hsa-miR-9/hsa-miR-9* are expressed more strongly in developing neurons and brain than in adult brain. Thus, their specific over-expression in brain primary tumors supports a functional role for these microRNAs or a link between neuronal stem cells and brain tumorigenesis.     

Heparanase is highly expressed and regulates proliferation in GH-secreting pituitary tumor cells

Pituitary tumorigenesis involves remodeling of the extracellular matrix (ECM). Heparanase, an endoglycosidase capable of degrading heparan sulfate, a major polysaccharide constituent of the ECM, is implicated in diverse processes associated with ECM remodeling, such as morphogenesis, angiogenesis, and tumor invasion. The aim of this study was to investigate the possible role of heparanase in pituitary tumorigenesis. Human normal pituitaries and pituitary tumors were examined for heparanase mRNA and protein expression using real-time PCR and immunohistochemistry, respectively. Cell proliferation was assessed by colony formation after heparanase overexpression in GH3 and MtT/S cells. Cell viability and cell cycle progression were evaluated after heparanase gene silencing. Higher heparanase mRNA and protein expression was noted in GH tumors as compared with normal pituitaries. Heparanase overexpression in GH3 and MtT/S cells resulted in a 2- to 3-fold increase in colony number, compared with control cells. Cell viability decreased by 50% after heparanase gene silencing due to induced apoptosis reflected by increased fraction of cleaved poly-ADP-ribose polymerase and sub-G1 events. Notably, exogenously added heparanase enhanced epidermal growth factor receptor, Src, Akt, ERK, and p38 phosphorylation in pituitary tumor cells. Our results indicate that heparanase enhances pituitary cell viability and proliferation and may thus contribute to pituitary tumor development and progression.     

Copolymer 1 induces T cells of the T helper type 2 that crossreact with myelin basic protein and suppress experimental autoimmune encephalomyelitis

The synthetic amino acid copolymer copolymer 1 (Cop 1) suppresses experimental autoimmune encephalomyelitis (EAE) and is beneficial in multiple sclerosis. To further understand Cop 1 suppressive activity, we studied the cytokine secretion profile of various Cop 1-induced T cell lines and clones. Unlike T cell lines induced by myelin basic protein (MBP), which secreted either T cell helper type 1 (Th1) or both Th1 and Th2 cytokines, the T cell lines/clones induced by Cop 1 showed a progressively polarized development toward the Th2 pathway, until they completely lost the ability to secrete Th1 cytokines. Our findings indicate that the polarization of the Cop 1-induced lines did not result from the immunization vehicle or the in vitro growing conditions, but rather from the tendency of Cop 1 to preferentially induce a Th2 response. The response of all of the Cop 1 specific lines/clones, which were originated in the (SJL/J×BALB/c)F₁ hybrids, was restricted to the BALB/c parental haplotype. Even though the Cop 1-induced T cells had not been exposed to the autoantigen MBP, they crossreacted with MBP by secretion of interleukin (IL)-4, IL-6, and IL-10. Administration of these T cells in vivo resulted in suppression of EAE induced by whole mouse spinal cord homogenate, in which several autoantigens may be involved. Secretion of anti-inflammatory cytokines by Cop 1-induced suppressor cells, in response to either Cop 1 or MBP, may explain the therapeutic effect of Cop 1 in EAE and in multiple sclerosis.