Magnetic Resonance Imaging Assessment of Subchondral Bone and Soft Tissues in Knee Osteoarthritis

Knee osteoarthritis (OA) has to be considered a whole joint disease. Magnetic resonance imaging (MRI) allows superior assessment of all joint tissues that may be involved in OA, such as the subchondral bone, synovium, ligaments, and periarticular soft tissues. Reliable MRI-based scoring systems are available to assess and quantify these structures and associated pathology. Cross-sectional and longitudinal evaluation has enabled practitioners to understand their relevance in explaining pain and structural progression.

Lower Extremities Magnetic Resonance Angiography With Blood Pressure Cuff Compression: Quantitative Dynamic Analysis

Purpose: To quantitatively evaluate changes induced by the application of a femoral blood-pressure cuff (BPC) on run-off magnetic resonance angiography (MRA). which is a method generally previously proposed to reduce venous contamination in the leg. Materials and Methods: This study was Health Insurance Portability and Accountability Act (HIPAA)- and Institutional Review Board (IRB)-compliant, We used time-resolved gradient-echo gadolinium (Gd)-enhanced MRA to measure BPC effects on arterial, venous, and soft-tissue enhancement. Seven healthy volunteers (six men) were studied with the BPC applied at the mid-femoral level unilaterally using a 1.5T MR system after intravenous injection of Gd-BOPTA. Different statistical tools were used such as the Wilcoxon signed rank test and a cubic smoothing spline fit. Results: We found that BPC application induces delayed venous filling (as previously described), but also induces significant decreases in arterial inflow, arterial enhancement, vascular-soft tissue contrast, and delayed peak enhancement (which have not been previously measured). Conclusion: The potential benefits from using a BPC for run-off MRA must be balanced against the potential pitfalls, elucidated by our findings.

Magnetic Resonance Imaging in Knee Osteoarthritis Research: Semiquantitative and Compositional Assessment

Semiquantitative assessment of the knee by expert magnetic resonance imaging readers is a powerful research tool for understanding the natural history of osteoarthritis (OA). Several reliable semiquantitative scoring systems have been applied to large observational cross-sectional and longitudinal epidemiologic studies and interventional clinical trials. Such evaluations have enabled understanding of the relevance of disease in structures within the knee joint to explain pain and progression of OA. Compositional imaging of cartilage has added to our ability to detect early degeneration before morphologic changes are present, which may help to prevent the permanent morphologic changes commonly seen in knee OA.

Magnetic Resonance Angiography in Extracranial Giant Cell Arteritis

Background: Noninvasive diagnosis of giant cell arteritis (GCA) remains challenging, particularly with regard to evaluation of extracranial arterial disease. Objectives: The objective of the study was to retrospectively review extracranial involvement in patients with GCA and/or polymyalgia rheumatica (PMR), evaluated with magnetic resonance imaging (MRI), especially 3-dimensional contrast-enhanced magnetic resonance angiography images of the aortic arch and its branches. Methods: Clinical information, biopsy status, and MRI examinations of 28 patients with GCA/PMR were reviewed. Patient images were mixed randomly with 20 normal control images and were independently reviewed by 2 radiologists. Interobserver agreement for detection of arterial stenosis was determined by the k coefficient. Results: Both readers described vascular alterations in keeping with extracranial GCA in 19 of 28 patients (67%) with good interobserver agreement (k = 0.73) and with even higher agreement on diagnosing nonocclusive versus occlusive disease (k = 1.00). The most common lesions were bilateral axillary stenosis or obstructions, observed by both readers in 8 patients (28%). Among the 19 patients with magnetic resonance angiography lesions in the subclavian/axillary arteries, 12 (75%) had biopsy-proven GCA, but only 5 (41%) of these patients had clinical features of large artery disease. Conclusions: In our series review, MRI could provide accurate information on involvement of the aortic arch and its branches in extracranial GCA, depicting different degrees of stenosis. Our analysis also illustrates that occult large artery vasculitis should be considered in patients without biopsy-proven GCA, patients with classic GCA but without clinical signs of large artery disease, and in patients initially diagnosed as having PMR.

Magnetic resonance imaging quantification of regional cerebral blood flow and cerebrovascular reactivity to carbon dioxide in normotensive and hypertensive rats

Hypertension afflicts 25% of the general population and over 50% of the elderly. In the present work, arterial spin labeling MRI was used to non-invasively quantify regional cerebral blood flow (CBE), cerebrovascular resistance and CO(2) reactivity in spontaneously hypertensive rats (SHR) and in normotensive Wistar Kyoto rats (WKY), at two different ages (3 months and 10 months) and under the effects of two anesthetics, alpha-chloralose and 2% isoflurane (1.5 MAC). Repeated CBE measurements were highly consistent, differing by less than 10% and 18% within and across animals, respectively. Under alpha-chloralose, whole brain CBE at normocapnia did not differ between groups (young WKY: 61 3 ml/100 g/min; adult WKY: 62 +/- 4 ml/100 g/min; young SHR: 70 +/- 9 ml/100 g/min: adult SHR: 69 8 ml/100 g/min), indicating normal cerebral autoregulation in SHR. At hypercapnia, CBE values increased significantly, and a linear relationship between CBE and PaCO(2) levels was observed. In contrast, 2% isoflurane impaired cerebral autoregulation. Whole brain CBE in SHR was significantly higher than in WKY rats at normocapnia (young SHR: 139 +/- 25 ml/100 g/min; adult SHR: 104 +/- 23 ml/100 g/min; young WKY: 55 +/- 9 ml/100 g/min; adult WKY: 71 +/- 19 ml/100 g/min). CBE values increased significantly with increasing CO(2): however, there was a clear saturation of CBF at PaCO(2) levels greater than 70 mm Hg in both young and adult rats, regardless of absolute CBE values, suggesting that isoflurane interferes with the vasoclilatory mechanisms of CO(2). This behavior was observed for both cortical and subcortical structures. Under either anesthetic, CO(2) reactivity values in adult SHR were decreased, confirming that hypertension, when combined with age, increases cerebrovascular resistance and reduces cerebrovascular compliance. Published by Elsevier Inc.

Stability improvement of the fatty acid binding protein Sm14 from S. mansoni by Cys replacement: Structural and functional characterization of a vaccine candidate

The Schistosoma mansoni fatty acid binding protein (FABP), SmA, is a vaccine candidate against, S. mansoni and F hepatica. Previously, we demonstrated the importance of a correct fold to achieve protection in immunized animals after cercariae challenge [[10]. C.R.R. Ramos, R.C.R. Figueredo, T.A. Pertinhez, M.M. Vilar, A.L.T.O. Nascimento, M. Tendler, I. Raw, A. Spisni, P.L. Ho, Gene structure and M20T polymorphism of the Schistosoma mansoni Sm14 fatty acid-binding protein: structural, functional and immunoprotection analysis. J. Biol. Chem. 278 (2003) 12745-12751]. Here we show that the reduction of vaccine efficacy over time is due to protein dimerization and subsequent aggregation. We produced the mutants Sm14-M20(C62S) and Sm14M20(C62V) that, as expected, did not dimerize in SDS-PAGE. Molecular dynamics calculations and unfolding experiments highlighted a higher structural stability of these mutants with respect to the wild-type. In addition, we found that the mutated proteins, after thermal denaturation, refolded to their active native molecular architecture as proved by the recovery of the fatty acid binding ability. Sm14-M20(C62V) turned out to be the more stable form over time, providing the basis to determine the first 3D solution structure of a Sm14 protein in its apo-form. Overall, Sm14-M20(C62V) possesses an improved structural stability over time, an essential feature to preserve its immunization capability and, in experimentally immunized animals, it exhibits a protection effect against S. mansoni cercariae infections comparable to the one obtained with the wild-type protein. These facts indicate this protein as a good lead molecule for large-scale production and for developing an effective Sm14 based anti-helminthes vaccine. (C) 2008 Elsevier B.V. All rights reserved.

Magnetic retention and bar-clip attachment for implant-retained auricular prostheses: A comparative analysis

Retention systems for implant-retained auricular prostheses using either bar-clip attachments with 2 or 3 clips or retention with 2 or 3 magnets were wear tested (insertion and removal cycles) to simulate clinical periods of use. Measurements were taken at intervals of 540 cycles, which represents a period of use of approximately 6 months, for up to 3,240 cycles. Assessments of retentive force were carried out before, during, and after the wear test. Statistical analysis indicated that the bar-clip systems provided higher retention than the magnetic systems. The bar-clip attachment with 2 clips showed a significant loss of retentive force after wear testing (P < .05), suggesting lower durability and shorter clinical life. The retention provided by the bar-clip attachment with 3 clips remained stronger than that provided by all other systems tested. At the end of the wear test, the magnetic systems showed very little loss of retention but were still less retentive than the bar-clip systems, suggesting higher durability under clinical simulation despite the lower retention initially provided.

Oral lesions and immune reconstitution syndrome in HIV+/AIDS patients receiving highly active antiretroviral therapy. Epidemiological evidence

Objective: To determine whether opportunistic oral infections associated to HIV infection (OOI-HIV) are found in HIV+/AIDS patients with immune reconstitution related to highly active antiretroviral therapy (HAART). Methods. From among 1100 HIV+/AIDS patients (Service of Internal Medicine, Carlos Haya Hospital, Malaga, Spain) subjected to review of the oral cavity between January 1996 and May 2007, we identified those examined in 1996 and which were again examined between 1997 and 2007, and were moreover receiving HAART. The following data were collected: age, gender, form of contagion, antiretroviral therapy at the time of review, number of CD4+ lymphocytes/ml, and viral load (from 1997 onwards). We identified those subjects with an increase in CD4+ lymphocytes/ ml associated to HAART, and classified them as subjects with quantitative evidence of immune reconstitution (QEIR). Among these individuals with QEIR we moreover identified those with undetectable viral loads (QEIR+VL), and differentiated those patients with an increase in CD4+ lymphocytes > 500/ml (QEIRm+VL). In each group we determined the prevalence of OOI-HIV, following the diagnostic recommendations of the EC-Clearinghouse (CDC-Atlanta, USA - WHO). In addition, we analyzed the prevalence of OOI-HIV in the different groups in relation to the duration of HAART. Results. A total of 86 subjects were included (44 females and 42 males; 19 heterosexuals, 34 male homosexuals, and 33 intravenous drug abusers). Forty-two patients showed QEIR: 21 belonged to the QEIR+VL group, and 17 conformed the QEIRm+VL group. The prevalence of OOI-HIV per group was as follows: QEIR = 54.8%; QEIR+VL = 33%; QEIRm+VL = 35%. The most prevalent lesion in all groups was erythematous candidiasis. OOI-HIV increased with the duration of HAART (p=0.008), and were seen to be dependent upon late appearance of the mycotic lesions ( after 24 months under HAART). Conclusions: It is suggested that opportunistic oral infections associated to HIV infection form part of the clinical picture of immune reconstitution inflammatory syndrome, though such infections are of late onset.

Evaluation of the lateral pterygoid muscle using magnetic resonance imaging

Objectives: The aims of this study were to evaluate the visibility of the lateral pterygoid muscle (LPM) in temporomandibular joint (TMJ) images obtained by MRI, using different projections and to compare image findings with clinical symptoms of patients with and without temporomandibular disorders (TMD). Methods: In this study, LPM images of 50 participants with and without TMDs were investigated by MRI. The images of the LPM in different projections of 100 TMJs from 35 participants (70 TMJs) with and 15 participants (30 TMJs) without clinical signs and symptoms of TMD were visible and analysed. Results: The oblique sagittal and axial images of the TMJ clearly showed the LPM. Hypertrophy (1.45%), atrophy (2.85%) and contracture (2.85%) were the abnormalities found in the LPM. TMD signs, such as hypermobility (11.4%), hypomobility (12.9%) and disc displacement (20.0%), could be seen in TMJ images. Related clinical symptoms, such as pain (71.4%), articular sounds (30.4%), bruxism (25.7%) and headache (22.9%), were observed. Conclusions: Patients with TMD can present with alterations in the LPM thickness. Patients without TMD also showed alterations, such as atrophy and contracture, in TMJ images. Recognition of alterations in the LPM will improve our understanding of clinical symptoms and pathophysiology of TMD, and may lead to a more specific diagnosis of these disorders. Dentomaxillofacial Radiology (2010) 39, 494-500. doi: 10.1259/dmfr/80928433

Acid phosphatase and cathepsin D are active expressed enzymes in the placenta of the cat

Enzymes are crucial for the metabolism of macromolecular substrates. In the great majority of cells, most enzymes are constitutive. Nevertheless, inducible enzymes can predominate, determining specialized cell functions. Within this context, histochemistry/immunohistochemistry and biochemistry were used to investigate expression of peroxidase and reduced nicotinamide-adenine dinucleotide phosphate (NADPH)-oxidase, as well as the expression and activity of cathepsin D and acid phosphatase, in trophoblast cells within the endotheliochorial labyrinth and marginal hematoma of the term cat placenta. In the marginal hematoma, elevated Cathepsin D expression and activity was accompanied by erythrophagocytosis. In contrast, acid phosphatase activity was much more intense in the labyrinth, where metabolic exchanges occur. Peroxidase and NAD(P)H-oxidase were predominantly active in trophoblast cells within endosomal vesicles of different placental compartments, indicating that, although reactive oxygen species might participate in endosomal/lysosomal processes, they are not territorially specific or functional markers. These findings highlight differential characteristics of cathepsin D and acid phosphatase activity within each placental compartment, thereby contributing to the comprehension of the territorial role played by the placenta and facilitating future metabolic studies. (C) 2007 Elsevier Ltd. All rights reserved.

HN-associated oral plasmablastic lymphoma and role of adherence to highly active antiretroviral therapy

Plasmablastic lymphoma (PBL) is an HIV-associated non-Hodgkin`s lymphoma that primarily affects the oral cavity. We describe the case of an HIV patient with a lesion in the maxilla that lasted four months. He was diagnosed with PBL and received highly active antiretroviral therapy as well as chemotherapy and local radiotherapy. The lesion regressed after the third cycle of chemotherapy. The patient interrupted antiretroviral treatment and the lesion recurred. The immune reconstitution secondary to the use of antiretroviral therapy seems to participate in the regression of PBL and maintains the remission of the tumour, but it might not be enough to prevent the development of PBL.

Comparative distalization effects of Jones jig and pendulum appliances

Introduction: In this study, we compared the dentoalveolar changes of Class II patients treated with Jones jig and pendulum appliances. Methods: The experimental group comprised 40 Class II malocclusion subjects, divided into 2 groups: group 1 consisted of 20 patients (11 boys, 9 girls) at a mean pretreatment age of 13.17 years, treated with the Jones jig appliance for 0.91 years; group 2 comprised 20 patients (8 boys, 12 grls) at a mean pretreatment age of 13.98 years, treated with the pendulum appliance for 1.18 years. Only active treatment time of molar distalization was evaluated in the predistalization and postdistalization lateral cephalograms. Molar, second premolar, and incisor angular and linear variables were obtained. The intergroup treatment changes in these variables were compared with independent t tests. Results: The maxillary second premolars showed greater mesial tipping and extrusion in the Jones jig group, indicating more anchorage loss during molar distalization with this appliance. The amounts and the monthly rates of molar distalization were similar in both groups. Conclusions: The Jones jig group showed greater mesial tipping and extrusion of the maxillary second premolars. The mean amounts and the monthly rates of first molar distalization were similar in both groups. (Am J Orthod Dentofacial Orthop 2009;135:336-42)

A genetic polymorphism of matrix metalloproteinase 9 (MMP-9) affects the changes in circulating MMP-9 levels induced by highly active antiretroviral therapy in HIV patients

We examined whether two functional polymorphisms (g.-1562C>T and g.-90(CA)14-24) in the matrix metalloproteinase (MMP)-9 gene or MMP-9 haplotypes affect the circulating levels of pro-MMP-9 and pro-MMP-9/TIMP-1 (tissue inhibitor of metalloproteinase-1) ratios in AIDS patients, and modulate alterations in these biomarkers after highly active antiretroviral therapy (HAART). We studied 82 patients commencing HAART. Higher pro-MMP-9 concentrations and pro-MMP-9/TIMP-1 ratios were found in CT/TT patients compared with CC patients. HAART decreased pro-MMP-9 levels and pro-MMP-9/TIMP-1 ratios in CT/TT patients, it did not modify pro-MMP-9 levels and it increased pro-MMP-9/TIMP-1 ratios in CC patients. The g.-90(CA)14-24 polymorphism, however, produced no significant effects. Moreover, we found no significant differences in HAART-induced changes in plasma pro-MMP-9, TIMP-1 and pro-MMP-9/TIMP-1 ratios when different MMP-9 haplotypes were compared. These findings suggest that the g.-1562C>T polymorphism affects pro-MMP-9 levels in patients with AIDS and modulates the alterations in pro-MMP-9 levels caused by HAART, thus possibly affecting the risk of cardiovascular complications. The Pharmacogenomics Journal (2009) 9, 265-273; doi: 10.1038/tpj.2009.13; published online 21 April 2009