Magnetic resonance imaging as a structural refinement to the American College of Rheumathology clinical classification criteria for knee osteoarthritis

OBJECTIVE

To evaluate if fulfilment of the definition of osteoarthritis (OA) based on the American College of Rheumatology (ACR) clinical criteria corresponds to pathological knee findings evaluated by magnetic resonance imaging (MRI). To evaluate if any such criteria is associated with a specific MRI pattern.

METHODS

Forty-six consecutive patients aged 50 years or more referred by their general practitioners (GPs) to a radiology department because of non-traumatic knee pain underwent MRI using a dedicated low field (0.2 T) machine.

RESULTS

MRI results were compared against the ACR criteria for knee OA. Patients with knee pain fulfilling the ACR criteria showed more severe synovial fluid effusion (OR 6.2, 95% CI 2.02 to 19.1), cartilage lesions in the medial area (OR 2.4, 95% CI 1.2 to 5) and higher mean number of osteophytes (OR 2.3, 95% CI 1.1 to 4.5). The association between single criteria and MRI features was more difficult to establish. Nonetheless, crepitus at joint movement was associated with synovial fluid effusion (p=0.02); bone enlargement was more frequent in patients with lesions of the posterior cruciate ligament (p=0.0001); no palpable warmth was associated with cartilage lesions (p=0.02), and morning stiffness shorter than 30 minutes was associated with the surface of bone edema (p=0.02).

CONCLUSIONS

The ACR clinical criteria identify patients showing the most important features of OA. The association between individual clinical ACR criteria and OA pathology depicted by MRI may be difficult to explain on the basis of anatomical changes and needs further evaluation.

POS1212 SARS-CoV-2 INFECTION AMONG PATIENTS WITH BEHÇET’S SYNDROME

Background:

Studies on SARS-Cov-2 in Behçet’s syndrome (BS) patients are limited to two small case series from European centres.[1,2]

Objectives:

We aimed to assess the prevalence of SARS-CoV-2 infection among Italian BS patients referring to Careggi University Hospital (Florence, Italy) and to evaluate the possible association between BS disease activity and treatment and the risk of Sars-CoV-2 infection among patients with BS.

Methods:

A survey was conducted among 335 subjects diagnosed with BS and followed at Careggi University Hospital. Moreover, we conducted a case-control study. Cases were described in term of SARS-CoV-2 manifestation and prognosis, changes in disease activity, and in pharmacological therapies. Sars-CoV-2 negative controls matched 1:3 by sex, age and disease duration ± 5 years were randomly selected.

Results:

Out of 335 BS patients, 12 declared to have/have had SARS-CoV-2 infection (3.6%). Eight were females (median age of 40 years), with a median duration of BS disease of 6 years; five had active disease. Nine patients reported fever, 9 myalgia/arthralgia, 5 gastrointestinal symptoms, 5 anosmia/ageusia, 5 cough, 3 headache, 3 fatigue, 2 breathlessness, panic attacks and dizziness (one each). Before infection, patients were treated with corticosteroids, colchicine, hydroxychloroquine (HCQ), traditional DMARDs [azathioprine (n patients = 4), methotrexate (n=1)], and biologics DMARDs [adalimumab (n=6), infliximab (n=2), secukinumab (n=1), and canakinumab (n=1)]. Therapy was suspended for a median time of 33 days in 9patients and resumed after a median time of 5 days from negativation. Regarding SARS-CoV-2 treatment, most patients started or increased corticosteroids, whereas heparin and antipyretic drugs were used in 4 and 5 patients, respectively. Cases were comparable to controls in terms of disease manifestations, activity, and immunomodulating therapy, with the only exception of corticosteroids, whose daily dose was significantly higher in cases (Table 1).

Conclusion:

Prevalence of SARS-CoV-2 infection among Italian BS patients is 3.6%, similarly to the Italian general population (4.2%). Disease activity at time of infection was not associated with an increased risk of SARS-CoV-2 infection. Most patients interrupted biologic DMARDs. However, use of DMARDs, seemed not to be associated with an increased risk of SARS-CoV-2 infection, while higher doses of corticosteroids resulted to be more common among patients with SARS-CoV-2 infection as compared to controls. No patient required hospitalization or died. Our experience shows encouraging data about BS patients who do not appear be at greater risk of SARS-CoV-2 infection or complications than the general population.

References:

[1]Espinosa et al. COVID-19 and Behçet’s disease: clinical case series. Ann Rheum Dis. 2020

[2]Yurttaş et al. Characteristics and outcomes of Behçet’s syndrome patients with Coronavirus Disease 2019: a case series of 10 patients. IEM. 2020

[3]http://www.salute.gov.it

Table 1.

Features of SARS-CoV-2+ cases and matched controls

12 SARS-CoV-2+ CASESPRE-INFECTION12 SARS-CoV-2+ CASESPOST-INFECTION36 CONTROLSp-value*Female sex8 (66.7%)24 (66.7%)Matching variableMedian age40 (IQR 31-45)40 (IQR 32-44)Matching variableMedian disease duration6 (IQR 5-9)6 (IQR 3-8)Matching variableActive disease (BDCAF≥1)5 (41.7%)4 had disease relapse24 (66.7%)0.176Immunomodulating therapyCorticosteroids –8 (66.7%)8 (66.7%)12 (33.3%)0.088Median dosage (IQR)5 (IQR 0-12.5)6 (IQR 0-15)0 (IQR 0-2.5)0.010Colchicine2 (16.7%)Continued11 (30.6%)0.469HCQ1 (8.3%)Continued1 (2.8%)0.441Traditional DMARDs5 (41.7%)1 interrupted8 (22.2%)0.263Biologic DMARDs10 (83.3%)8 interrupted27 (75%)0.705Disease involvementMucocutaneous5 (41.7%)12 (33.3%)0.731Articular5 (41.7%)4 worsened17 (47.2%)1.000Ocular02 (5.6%)n.a.Vascular00n.a.Neurological3 (25%)8 (22.2%)1.000Gastrointestinal2 (16.7%)1 worsened6 (16.7%)1.000

*p-value from Fisher exact test for unpaired data between first columns vs third columns

Disclosure of Interests:

None declared.

Behçet's syndrome as a tool to dissect the mechanisms of thrombo-inflammation: clinical and pathogenetic aspects

Behçet's syndrome (BS) is a complex disease with different organ involvement. The vascular one is the most intriguing, considering the existence of a specific group of patients suffering from recurrent vascular events involving the venous and, more rarely, the arterial vessels. Several clinical clues suggest the inflammatory nature of thrombosis in BS, especially of the venous involvement, thus BS is considered a model of inflammation-induced thrombosis. Unique among other inflammatory conditions, venous involvement (together with the arterial one) is currently treated with immunosuppressants, rather than with anti-coagulants. Although many in-vitro studies have suggested the different roles of the multiple players involved in clot formation, in-vivo models are crucial to study this process in a physiological context. At present, no clear mechanisms describing the pathophysiology of thrombo-inflammation in BS exist. Recently, we focused our attention on BS patients as a human in-vivo model of inflammation-induced thrombosis to investigate a new mechanism of clot formation. Indeed, fibrinogen displays a critical role not only in inflammatory processes, but also in clot formation, both in the fibrin network and in platelet aggregation. Reactive oxygen species (ROS)-derived modifications represent the main post-translational fibrinogen alterations responsible for structural and functional changes. Recent data have revealed that neutrophils (pivotal in the pathogenetic mechanisms leading to BS damage) promote fibrinogen oxidation and thrombus formation in BS. Altogether, these new findings may help understand the pathogenetic bases of inflammation-induced thrombosis and, more importantly, may suggest potential targets for innovative therapeutic approaches.

Heterogeneity of Cortical Lesion Susceptibility Mapping in Multiple Sclerosis

BACKGROUND AND PURPOSE

Quantitative susceptibility mapping has been used to characterize iron and myelin content in the deep gray matter of patients with multiple sclerosis. Our aim was to characterize the susceptibility mapping of cortical lesions in patients with MS and compare it with neuropathologic observations.

MATERIALS AND METHODS

The pattern of microglial activation was studied in postmortem brain tissues from 16 patients with secondary-progressive MS and 5 age-matched controls. Thirty-six patients with MS underwent 3T MR imaging, including 3D double inversion recovery and 3D-echo-planar SWI.

RESULTS

Neuropathologic analysis revealed the presence of an intense band of microglia activation close to the pial membrane in subpial cortical lesions or to the WM border of leukocortical cortical lesions. The quantitative susceptibility mapping analysis revealed 131 cortical lesions classified as hyperintense; 33, as isointense; and 84, as hypointense. Quantitative susceptibility mapping hyperintensity edge found in the proximity of the pial surface or at the white matter/gray matter interface in some of the quantitative susceptibility mapping-hyperintense cortical lesions accurately mirrors the microglia activation observed in the neuropathology analysis.

CONCLUSIONS

Cortical lesion susceptibility maps are highly heterogeneous, even at individual levels. Quantitative susceptibility mapping hyperintensity edge found in proximity to the pial surface might be due to the subpial gradient of microglial activation.

Analysis of waste management issues arising from a field study evaluating decontamination of a biological agent from a building

The Bio-response Operational Testing and Evaluation (BOTE) Project was a cross-government effort designed to operationally test and evaluate a response to a biological incident (release of Bacillus anthracis [Ba] spores, the causative agent for anthrax) from initial public health and law enforcement response through environmental remediation. The BOTE Project was designed to address site remediation after the release of a Ba simulant, Bacillus atrophaeus spp. globigii (Bg), within a facility, drawing upon recent advances in the biological sampling and decontamination areas. A key component of response to a biological contamination incident is the proper management of wastes and residues, which is woven throughout all response activities. Waste is generated throughout the response and includes items like sampling media packaging materials, discarded personal protective equipment, items removed from the facility either prior to or following decontamination, aqueous waste streams, and materials generated through the application of decontamination technologies. The amount of residual contaminating agent will impact the available disposal pathways and waste management costs. Waste management is an integral part of the decontamination process and should be included through "Pre-Incident" response planning. Overall, the pH-adjusted bleach decontamination process generated the most waste from the decontamination efforts, and fumigation with chlorine dioxide generated the least waste. A majority of the solid waste generated during pH-adjusted bleach decontamination was the nonporous surfaces that were removed, bagged, decontaminated ex situ, and treated as waste. The waste during the two fumigation rounds of the BOTE Project was associated mainly with sampling activities. Waste management activities may represent a significant contribution to the overall cost of the response/recovery operation. This paper addresses the waste management activities for the BOTE field test.

IMPLICATIONS

Management of waste is a critical element of activities dealing with remediation of buildings and outdoor areas following a biological contamination incident. Waste management must be integrated into the overall remediation process, along with sampling, decontamination, resource management, and other important response elements, rather than being a stand-alone activity. The results presented in this paper will provide decision makers and emergency planners at the federal/state/tribal/local level information that can be used to integrate waste management into an overall systems approach to planning and response activities.

Rheumatoid trigger wrist

No abstract available

Medical treatment of joint prosthesis: indication, opportunities and liability profiles

Orthopaedic specialists should completely and sequentially manage osteoarthritis, from the onset to the prosthesis, with no attitude of resignation, complying with national and international Guidelines (GLs) and abiding by the criteria of appropriateness of drugs, rehabilitation and orthopaedic device prescription, in line with the ethics of the medical profession. The GLs are a paper that rationalises the quantity of existing information for a disease, without abusing the decision of the doctor; a large volume of scientific knowledge is concentrated in a format that is easily accessible to doctors when carrying out their work. The use of drugs has taken on a connotation of a rational and multifactorial choice, rather than an accidental and incremental choice - inspired only by safety, rather than efficacy criteria. The Notes compiled by the Italian Medicines Agency - a legal instrument to define the reimbursability of medicines and, therefore, an instrument for managing pharmaceutical expenditure – are, in reality, a means to guarantee the appropriateness of the use of medicines, orienting the therapeutic choices according to established Guidelines. In the specific case of osteoarthritis, the knowledge of the GLs is the most appropriate and complete approach towards the disease, in the context of its pathogenetic complexity in its natural history. Moreover, pharmacological treatment of the subchondral osteometabolic damage becomes necessary when documented by magnetic resonance or a scintigraphy; the bone-related pain cannot be challenged through symptomatic analgesic treatment alone.

METABOLIC BONE CHANGES IN OSTEOARTHRITIS: THE ROLE OF IMAGING AND PATHOGENETIC INTERPRETATION

Osteoarthritis (OA) is the most prevalent chronic joint disease and one of the major causes of disability in the adult population. Although OA is considered a progressive degenerative process which involves the whole joint, articular cartilage and subchondral bone play a determinant role in its pathogenesis. In particular, metabolic-triggered subchondral bone damage, together with biochemical markers, are referred as important indicators of the disease. Magnetic resonance (MR) is the best imaging technique to detect and characterize such bone abnormalities. It represents an effective method through which to not only diagnose, describe and follow the course of OA but also to deepen our understanding of the natural history of the disease, with the ultimate purpose of attaining improved outcome in terms of therapy and prognosis. Even though MR has enormous potential, some diagnostic pitfalls may occur in clinical practice, hence an accurate clinical assessment of the patient is mandatory in combination with optimal imaging evaluation.

Topical promethazine side effects: our experience and review of the literature

Promethazine hydrochloride is a first-generation H1 receptor antagonist, antihistamine, and antiemetic medication that can also have strong sedative effects. The apparent ability of topical H1r/2r antagonists to target epidermal H1/2r was translated into increased efficacy in the treatment of inflammatory dermatoses, likely due to decreased inflammation and enhanced barrier function.

Systemic lupus erythematosus: immunopathogenesis and novel therapeutic targets

Systemic lupus erythematosus (SLE) is the prototype of autoimmune diseases with multiorgan involvement. SLE presents many genetic and epigenetic associations and the pathogenesis is characterized by a complex network of alterations affecting both adaptative and innate immunity. The disclosure of novel mechanisms of SLE pathogenesis suggested new therapeutic targets, based on interference with the cytokine pathways or on depletion of the immune cells.

Exenatide promotes cognitive enhancement and positive brain metabolic changes in PS1-KI mice but has no effects in 3xTg-AD animals

Recent studies have shown that type 2 diabetes mellitus (T2DM) is a risk factor for cognitive dysfunction or dementia. Insulin resistance is often associated with T2DM and can induce defective insulin signaling in the central nervous system as well as increase the risk of cognitive impairment in the elderly. Glucagone like peptide-1 (GLP-1) is an incretin hormone and, like GLP-1 analogs, stimulates insulin secretion and has been employed in the treatment of T2DM. GLP-1 and GLP-1 analogs also enhance synaptic plasticity and counteract cognitive deficits in mouse models of neuronal dysfunction and/or degeneration. In this study, we investigated the potential neuroprotective effects of long-term treatment with exenatide, a GLP-1 analog, in two animal models of neuronal dysfunction: the PS1-KI and 3xTg-AD mice. We found that exenatide promoted beneficial effects on short- and long-term memory performances in PS1-KI but not in 3xTg-AD animals. In PS1-KI mice, the drug increased brain lactate dehydrogenase activity leading to a net increase in lactate levels, while no effects were observed on mitochondrial respiration. On the contrary, exenatide had no effects on brain metabolism of 3xTg-AD mice. In summary, our data indicate that exenatide improves cognition in PS1-KI mice, an effect likely driven by increasing the brain anaerobic glycolysis rate.

A case of sensitization to alitretinoin

Alitretinoin is a unique retinoid authorised for the treatment of adults with severe chronic hand eczema (CHE) refractory to potent topical steroids. The most common adverse events (AEs) were typical class effects of oral retinoids including headache, flushing and skin disorders. To our knowledge, there are no cases of sensitization to alitretinoin reported in literature. We present a case of sensitization to alitretinoin.

Helicobacter Pylori HP0175 Promotes the Production of IL-23, IL-6, IL-1β and TGF-β

Helicobacter pylori infection induces a chronic gastric inflammatory infiltrate. This study was undertaken to evaluate the type of the innate immune responses elicited by the secreted peptidyl-prolyl cis-trans isomerase of H. pylori (HP0175). The cytokine production induced by HP0175 in neutrophils, and monocytes was evaluated. HP0175 was able to induce the expression of IL-23 in neutrophils, and monocytes, and IL-6, IL-1beta and TGF-beta in monocytes. These findings indicate that HP0175 is able to promote the activation of innate cells and the production of a cytokine milieu that may favour the development of Th17 response.

Effects of long-term treatment with pioglitazone on cognition and glucose metabolism of PS1-KI, 3xTg-AD, and wild-type mice

In this study, we investigated the effects of long-term (9-month) treatment with pioglitazone (PIO; 20 mg/kg/d) in two animal models of Alzheimer's disease (AD)-related neural dysfunction and pathology: the PS1-KI(M146V) (human presenilin-1 (M146V) knock-in mouse) and 3xTg-AD (triple transgenic mouse carrying AD-linked mutations) mice. We also investigated the effects on wild-type (WT) mice. Mice were monitored for body mass changes, fasting glycemia, glucose tolerance, and studied for changes in brain mitochondrial enzyme activity (complexes I and IV) as well as energy metabolism (lactate dehydrogenase (LDH)). Cognitive effects were investigated with the Morris water maze (MWM) test and the object recognition task (ORT). Behavioral analysis revealed that PIO treatment promoted positive cognitive effects in PS1-KI female mice. These effects were associated with normalization of peripheral gluco-regulatory abnormalities that were found in untreated PS1-KI females. PIO-treated PS1-KI females also showed no statistically significant alterations in brain mitochondrial enzyme activity but significantly increased reverse LDH activity.PIO treatment produced no effects on cognition, glucose metabolism, or mitochondrial functioning in 3xTg-AD mice. Finally, PIO treatment promoted enhanced short-term memory performance in WT male mice, a group that did not show deregulation of glucose metabolism but that showed decreased activity of complex I in hippocampal and cortical mitochondria. Overall, these results indicate metabolically driven cognitive-enhancing effects of PIO that are differentially gender-related among specific genotypes.

High-resolution ultrasound of the extrinsic carpal ligaments

Thanks to its intrinsic high spatial resolution, ultrasound is an ideal imaging modality for examining very thin, superficial structures, and this makes it very helpful in the evaluation of extrinsic carpal ligaments. These structures, which arise from the radius and ulna and insert on the carpal bones, are extremely important for wrist stability. Previous studies have assessed the use of ultrasound to study the extrinsic carpal ligaments in cadavers, healthy asymptomatic subjects, and patients with rheumatoid arthritis. In the present report, we review the normal anatomy, biomechanics, and ultrasound appearance of these ligaments.

Novel POMGNT1 point mutations and intragenic rearrangements associated with muscle-eye-brain disease

Congenital muscular dystrophies due to defects in genes encoding proteins involved in α-dystroglycan (α-DG) glycosylation are a heterogeneous group of muscle disorders variably associated with central nervous system and eye abnormalities. One of the more severe is muscle-eye-brain disease (MEB). Mutations in genes coding for proven or putative glycosyltransferases (POMT1, POMT2, POMGnT1, fukutin, FKRP, and LARGE), the DPM3 gene encoding a DOL-P-Man synthase subunit, and the DAG1 gene encoding α-dystroglycan, have been associated with altered α-DG glycosylation.

We report new POMGnT1 mutations and evaluate protein expression in 3 patients and 2 foetuses with variably severe MEB features. We identify two new point mutations (c.643 C > T, c.1863delC), one new intragenic rearrangement (deletion of exons 2–8), and a new intron retention (between exons 21 and 22) resulting from a known point mutation c.1895 + 1 G > T. Our study provides further evidence that rearrangements of the POMGnT1 gene are relatively common. Importantly, if heterozygous, they can be missed on standard genomic DNA sequencing. POMGNT1 protein analysis in 3 patients showed that the severity of the phenotype does not correlate with protein expression. Cerebral MRI is important for identifying MEB and α-dystroglycanopathy phenotypes in children and foetuses, and hence for directing the genetic analysis.

Preliminary ultrasound evaluation of the rotator cable in asymptomatic volunteers()

PURPOSE

To characterize the rotator cable high-resolution ultrasound appearance in asymptomatic shoulders of volunteers of different age.

MATERIALS AND METHODS

IRB approval and volunteers' written consent was obtained. Excluding subjects with known shoulder affections, we screened 24 asymptomatic volunteers. Supraspinatus and infraspinatus tendons high-resolution ultrasound evaluation was performed according to standard scan protocols, further excluding shoulders with partial/full-thickness cuff tears. Thus, we studied 24 shoulders in 12 young volunteers (age range 21-39 years, mean age 33 ± 8 years) and 21 shoulders in 11 elderly volunteers (age range 62-83 years, mean age 75 ± 45 years). For each shoulder, we noted rotator cable visibility and its thickness and width. Fisher's and U Mann-Whitney statistics were used.

RESULTS

Rotator cable was less frequently detected in young than in elderly volunteers (5/24 vs. 11/21 shoulders; P = 0.034). When detected, rotator cable was significantly thicker in young (range 1.2-1.5 mm, mean thickness 1.3 ± 0.1 mm) than in elderly (range 0.9-1.4 mm, mean thickness 1.2 ± 0.1 mm) volunteers (P = 0.025), while its width was not significantly different in young (range 4.5-7.1 mm, mean 5.6 ± 1.1 mm) compared to elderly (range 2.5-7.1 mm, mean 4.2 ± 1.4 mm) volunteers (P = 0.074) although a tendency can be highlighted.

CONCLUSIONS

Ultrasound demonstrated the different consistency of rotator cable in young and elderly asymptomatic patients, with high interobserver reproducibility.

Correlation between radiographic, echographic and MRI changes and rheumatoid arthritis progression

OBJECTIVES

To review the imaging methods used for the evaluation of disease progression in rheumatoid arthritis (RA) and to evaluate the results of their application in pharmacological trials.

METHODS

Literature articles dealing with radiology, echography, and magnetic resonance imaging (MRI) of patients with RA were evaluated in a non-systematic fashion.

RESULTS

Conventional radiology is the gold standard for the evaluation of disease progression in RA because of its diffusion, economy, and standardization. Different techniques have been proposed to evaluate radiological damage of the joints, with the Larsen's and Sharp's methods being most widely used. These methods are commonly used for the evaluation of the ability of DMARDs to slow RA progression. Among traditional DMARDs, gold salts, sulphasalazine, methotrexate, cyclosporin, and leflunomide have shown efficacy in slowing the appearance of new erosions. The same effect has been recently demonstrated for infliximab plus methotrexate, anakinra and etanercept. However, conventional radiology has several disadvantages, because it is monoplanar and has a low sensitivity to change. Newer imaging techniques, such as echography and MRI are extensively studied and have been used occasionally in the mediumterm evaluation of DMARDs, with promising results.

CONCLUSIONS

Although conventional radiology is still the gold standard for the evaluation of disease progression in RA, newer techniques are increasingly studied. In particular, standardization of echographic and MRI imaging of the joints is in progress.

The Simpson-Golabi-Behmel syndrome: A clinical case and a detective story

The Simpson-Golabi-Behmel syndrome (SGBS) is an overgrowth condition comprising "coarseness" of facial traits, supernumerary nipples, congenital heart defects, polydactyly and fingernail hypoplasia, and an increased risk of neonatal death and later neoplasia. Psychomotor development is usually normal. The syndrome is caused by mutation/deletion of the X-linked gene GPC3. We describe a new case of SGBS, that led to the discovery of an extended family segregating a GPC3 mutation and, ultimately, of an affected relative forgotten, but not lost, in an anatomical museum, where he was classified as a macrosomic newborn, who was born probably around 1940 and died neonatally of unknown cause. This baby boy becomes the oldest case of SGBS on record.

Dietary zinc supplementation of 3xTg-AD mice increases BDNF levels and prevents cognitive deficits as well as mitochondrial dysfunction

The overall effect of brain zinc (Zn²⁺) in the progression and development of Alzheimer's disease (AD) is still not completely understood. Although an excess of Zn²⁺ can exacerbate the pathological features of AD, a deficit of Zn²⁺ intake has also been shown to increase the volume of amyloid plaques in AD transgenic mice. In this study, we investigated the effect of dietary Zn²⁺ supplementation (30 p.p.m.) in a transgenic mouse model of AD, the 3xTg-AD, that expresses both β amyloid (Aβ)- and tau-dependent pathology. We found that Zn²⁺ supplementation greatly delays hippocampal-dependent memory deficits and strongly reduces both Aβ and tau pathology in the hippocampus. We also evaluated signs of mitochondrial dysfunction and found that Zn²⁺ supplementation prevents the age-dependent respiratory deficits we observed in untreated 3xTg-AD mice. Finally, we found that Zn²⁺ supplementation greatly increases the levels of brain-derived neurotrophic factor (BDNF) of treated 3xTg-AD mice. In summary, our data support the idea that controlling the brain Zn²⁺ homeostasis may be beneficial in the treatment of AD.

Alterations of brain and cerebellar proteomes linked to Aβ and tau pathology in a female triple-transgenic murine model of Alzheimer's disease

The triple-transgenic Alzheimer (3 × Tg-AD) mouse expresses mutant PS1(M146V), APP(swe), and tau(P301L) transgenes and progressively develops plaques and neurofibrillary tangles with a temporal- and region-specific profile that resembles the neuropathological progression of Alzheimer's disease (AD). In this study, we used proteomic approaches such as two-dimensional gel electrophoresis and mass spectrometry to investigate the alterations in protein expression occurring in the brain and cerebellum of 3 × Tg-AD and presenilin-1 (PS1) knock-in mice (animals that do not develop Aβ- or tau-dependent pathology nor cognitive decline and were used as control). Finally, using the Ingenuity Pathway Analysis we evaluated novel networks and molecular pathways involved in this AD model. We identified several differentially expressed spots and analysis of 3 × Tg-AD brains showed a significant downregulation of synaptic proteins that are involved in neurotransmitter synthesis, storage and release, as well as a set of proteins that are associated with cytoskeleton assembly and energy metabolism. Interestingly, in the cerebellum, a structure not affected by AD, we found an upregulation of proteins involved in carbohydrate metabolism and protein catabolism. Our findings help to unravel the pathogenic brain mechanisms set in motion by mutant amyloid precursor protein (APP) and hyperphosphorylated tau. These data also reveal cerebellar pathways that may be important to counteract the pathogenic actions of Aβ and tau, and ultimately offer novel targets for therapeutic intervention.

Defining the transcriptomic and proteomic profiles of rat ageing skeletal muscle by the use of a cDNA array, 2D- and Blue native-PAGE approach

We defined the transcriptomic and proteomic profiles of rat ageing skeletal muscle using a combined cDNA array, 2D- and Blue native-PAGE approach. This was allowed to obtain an overview of the interrelated events leading to the transcriptome/proteome/mitoproteome changes likely to underlie the structural/metabolic features of aged skeletal muscle. The main differences were found in genes/proteins related to energy metabolism, mitochondrial pathways, myofibrillar filaments, and detoxification. Concerning the abundance of mitochondrial OXPHOS complexes as well as their supramolecular organization and activity, mitochondria from old rats, when compared with those from young rats, contained significantly lower amounts of complex I (NADH:ubiquinone oxidoreductase), V (FoF1-ATP synthase), and III (ubiquinol:cytochrome c oxidoreductase). The same mitochondria contained a significantly larger amount of complex II (succinate:ubiquinone oxidoreductase), but an unchanged amount of complex IV (cytochrome c oxidase, COX). When comparing the supercomplex profiles between young and old muscle mitochondria, the densitometric analysis revealed that lighter supercomplexes were significantly reduced in older mitochondria, and that in the older group the major supercomplex bands were those representing heavier supercomplexes, likely suggesting a compensatory mechanism that, in ageing muscle, is functionally directed towards substrate channeling and catalytic enhancement advantaging the respirosome.

3,5-Diiodo-L-thyronine rapidly enhances mitochondrial fatty acid oxidation rate and thermogenesis in rat skeletal muscle: AMP-activated protein kinase involvement

Triiodothyronine regulates energy metabolism and thermogenesis. Among triiodothyronine derivatives, 3,5-diiodo-l-thyronine (T(2)) has been shown to exert marked effects on energy metabolism by acting mainly at the mitochondrial level. Here we investigated the capacity of T(2) to affect both skeletal muscle mitochondrial substrate oxidation and thermogenesis within 1 h after its injection into hypothyroid rats. Administration of T(2) induced an increase in mitochondrial oxidation when palmitoyl-CoA (+104%), palmitoylcarnitine (+80%), or succinate (+30%) was used as substrate, but it had no effect when pyruvate was used. T(2) was able to 1) activate the AMPK-ACC-malonyl-CoA metabolic signaling pathway known to direct lipid partitioning toward oxidation and 2) increase the importing of fatty acids into the mitochondrion. These results suggest that T(2) stimulates mitochondrial fatty acid oxidation by activating several metabolic pathways, such as the fatty acid import/beta-oxidation cycle/FADH(2)-linked respiratory pathways, where fatty acids are imported. T(2) also enhanced skeletal muscle mitochondrial thermogenesis by activating pathways involved in the dissipation of the proton-motive force not associated with ATP synthesis ("proton leak"), the effect being dependent on the presence of free fatty acids inside mitochondria. We conclude that skeletal muscle is a target for T(2), and we propose that, by activating processes able to enhance mitochondrial fatty acid oxidation and thermogenesis, T(2) could play a role in protecting skeletal muscle against excessive intramyocellular lipid storage, possibly allowing it to avoid functional disorders.

[Dynamic contrast-enhanced magnetic resonance imaging of the wrist in early arthritis]

OBJECTIVES

MRI has been proposed as the imaging method of choice to evaluate the long-term outcome in patients with early arthritis. The role of dynamic MRI, performed at presentation, in predicting the outcome of patients with early arthritis has been addressed in the present study.

METHODS

39 patients with early arthritis, involving at least one wrist, were studied with clinical visits and laboratory investigations, every 3 months. Dynamic MRI was performed with a low-field (0.2T), extremity-dedicated machine (Artoscan, Esaote, Genova, Italy) equipped with a permanent magnet and with a dedicated hand and wrist coil. During the intravenous injection of Gd-DTPA, twenty consecutive fast images of 3 slices of the wrist were acquired. The synovial contrast enhancement ratio was calculated both as rate of early enhancement (REE) per second during the first 55" and as relative enhancement (RE) at t seconds.

RESULTS

In our cohort of patients, REE and RE were significantly lower than those observed in a historical cohort of 36 patients with active rheumatoid arthritis. In univariate analysis, low RE predicted complete remission of arthritis. In multivariate analysis, fulfillment of RA criteria during follow-up was predicted by high RE. The need for immunosoppressive treatment at the end of follow-up was predicted by both low RE and high REE.

CONCLUSIONS

Dynamic MRI may be used to predict several outcomes of early arthritis involving the wrist.

[Magnetic resonance imaging of the peripheral joints in psoriatic arthritis]

OBJECTIVE

Magnetic resonance imaging (MRI) has been widely used for the evaluation of rheumatoid arthritis (RA), with only a minority of studies considering other types of arthritis. This review is concerned with an evaluation of the MRI appearance of peripheral joints in psoriatic arthritis (PsA).

METHODS

A Medline search was performed to identify all publications from the years 1985 to 2006 concerning MRI of the peripheral joints and PsA. Additional papers were retrieved by scanning the references to the Medline-listed articles. Articles written in English, French, German, and Italian were included.

RESULTS

Most papers studied the hand and wrist, and only few of them were concerned with the knee, foot, temporomandibular joint, and elbow. Patients with PsA showed often, but not always, a pattern of joint inflammation which extended beyond the capsule into the extraarticular tissue. Bone oedema and erosions were less frequent than in RA. In particular, bone oedema at the entheseal junction was seen, especially in the knee. The degree of synovitis, assessed by dynamic MRI, was similar in PsA and RA.

DISCUSSION

Data on MRI of the peripheral joints in PsA are scanty. Only few studies were specifically designed to evaluate the pattern of arthritis in PsA, with most information deriving from papers where different types of arthritis were considered together. An enthesis-related origin of PsA has been proposed in contrast to the primarily synovial inflammation of RA. This pathogenic interpretation is likely to be true, but does not explain all cases of PsA, and needs to be confirmed by further studies.

How normal are the hands of normal controls? A study with dedicated magnetic resonance imaging

OBJECTIVE

To investigate bone and soft tissue changes in the hands of normal subjects by MRI.

METHODS

Twenty-three normal volunteers (16 women) agreed to be examined. MRI of the hand was performed with a dedicated-extremity 0.2 Tesla device using gradient echo, spin echo and STIR sequences. Joint space width was measured in 16 different locations of the hand. Bone lesions, including bone oedema, ankylosis, and erosions, as well as the presence of tenosynovitis were investigated.

RESULTS

Reproducibility of measures of joint space width was relatively good with an intraclass correlation coefficient of 0.82 and 0.71 in the intra-observer and inter-observer evaluations, respectively. No age- or sex-related differences of joint space were observed. Reproducibility of the readings of bone oedema and tenosynovitis were optimal. Bone oedema and erosions were observed in 2/23 (8.7%) and in 6/23 (26.1%) subjects, respectively. Tenosynovitis of the extensor tendons was present in 1/23 subjects (4.3%), whereas tenosynovitis of the flexor tendons was seen in 4/23 (17.4%).

CONCLUSION

This study demonstrates that joint changes considered to be peculiar of arthritis can be found by MRI in a relevant percentage of healthy subjects. Our data suggest that a control group of healthy subjects should be included in MRI studies on the appearance of the wrist in disease.

Thyroid hormones as molecular determinants of thermogenesis

Thyroid hormones (TH) are major modulators of energy metabolism and thermogenesis. It is generally believed that 3,5,3'-triiodo-l-thyronine (T3) is the only active form of TH, and that most of its effects are mediated by nuclear T3 receptors, which chiefly affect the transcription of target genes. Some of these genes encode for the proteins involved in energy metabolism. However, a growing volume of evidence now indicates that other iodothyronines may be biologically active. Several mechanisms have been proposed to explain the calorigenic effect of TH, but none has received universal acceptance. Cold acclimation/exposure and altered nutritional status are physiological conditions in which a modulation of energy expenditure is particularly important. TH seem to be deeply involved in this modulation, and this article will review some aspects of their possible influence in these conditions.

Thyroid-hormone effects on putative biochemical pathways involved in UCP3 activation in rat skeletal muscle mitochondria

In vitro, uncoupling protein 3 (UCP3)-mediated uncoupling requires cofactors [e.g., superoxides, coenzyme Q (CoQ) and fatty acids (FA)] or their derivatives, but it is not yet clear whether or how such activators interact with each other under given physiological or pathophysiological conditions. Since triiodothyronine (T3) stimulates lipid metabolism, UCP3 expression and mitochondrial uncoupling, we examined its effects on some biochemical pathways that may underlie UCP3-mediated uncoupling. T3-treated rats (Hyper) showed increased mitochondrial lipid-oxidation rates, increased expression and activity of enzymes involved in lipid handling and increased mitochondrial superoxide production and CoQ levels. Despite the higher mitochondrial superoxide production in Hyper, euthyroid and hyperthyroid mitochondria showed no differences in proton-conductance when FA were chelated by bovine serum albumin. However, mitochondria from Hyper showed a palmitoyl-carnitine-induced and GDP-inhibited increased proton-conductance in the presence of carboxyatractylate. We suggest that T3 stimulates the UCP3 activity in vivo by affecting the complex network of biochemical pathways underlying the UCP3 activation.

Novel and recurrent mutations in the integrin beta 4 subunit gene causing lethal junctional epidermolysis bullosa with pyloric atresia

In this study we examined two unrelated patients affected with the lethal variant of junctional epidermolysis bullosa with pyloric atresia (PA-JEB) who were found to carry mutations in the integrin beta4 subunit gene (ITGB4). Although in both patients Northern blot analysis showed only a 50% reduction in the level of ITGB4 transcript, a complete lack (patient 1) or a strong reduction (patient 2) of beta4 immunoreactivity was observed in the skin. Using immunoprecipitation analysis, integrin beta4 could not be visualized in patient 1 cells while a markedly reduced amount (approximately 20%) of normal sized beta4 chains was detected in patient 2. These data suggested the presence of ITGB4 mutations that interfere with both mRNA and protein stability. Using molecular analysis, patient 1 was shown to be a compound heterozygous for a single amino acid deletion (deltaN318) and a not yet identified mutation that induces a very rapid decay of the encoded mRNA transcript. Patient 2 was, instead, a compound heterozygous for a novel 4-bp tandem duplication (4298-4299ins4) and a previously described missense mutation (R252C). Our data support the notion that PA-JEB lethal phenotypes associated with a markedly decreased/absent alpha6beta4 expression can be due not only to the presence of null alleles, but also to specific mutations leading to protein instability and/or altered function.

Power Doppler analysis of tendon vascularization

Forty-nine patients with tendonitis (patellar in 16, quadriceps in two, Achilles in 12, rotator cuff disease in 19) and 47 patients with tenosynovitis (acute tenosynovitis in 25, stenosing tenosynovitis in 22) underwent ultrasound (US) and Power Doppler (PD)-US examination. Spectral analysis of flow signals was performed in all patients. Ten patients (six with tendonitis, four with tenosynovitis) were rewired after medical therapy. Six healthy volunteers were also examined for control purposes. Three different patterns of flow distribution were found in patients with tendonitis and active tenosynovitis. The vessels of tendons without tendon sheaths began with great peduncles at the level of the peritendinous soft tissues and were then distributed inside the tendon (pattern I). A clear peritendinous hypervascular pattern was found in all active tenosynovitis, but no vessels were found inside the tendons (pattern II). In some cases of intratendinous or partial lesions PD-US revealed some vessels located near or inside the lesion (pattern II). On spectral analysis these vessels corresponded to arteries with a low resistance index or small venules. PD-US revealed a significant reduction of flow signals in patients rewired after medical therapy. No pathological flow signals were found either in patients with stenosing tenosynovitis or in the control group. PD-US gives us an in vivo confirmation of tendon vascularity. Spectral analysis adds further information to gray-scale US.

Skeletal muscle mitochondrial free-fatty-acid content and membrane potential sensitivity in different thyroid states: involvement of uncoupling protein-3 and adenine nucleotide translocase

The effect of triiodothyronine (T3) on mitochondrial efficiency could be related to an increase in the concentrations of some proteins, such as uncoupling proteins (UCPs). Free fatty acids (FFA) seem to be a cofactor essential for the uncoupling activity of UCP3. In this paper, we report that the hypothyroidism-hyperthyroidism transition is accompanied by increases: (i) in the endogenous levels of mitochondrial FFA and (ii) in the sensitivity to FFA shown by the mitochondrial respiration rate and membrane potential, which correlated with the level of UCP3 protein. The level of the mRNA for adenine-nucleotide translocase-1 (ANT) was not affected by the thyroid state, while the ANT contribution to FFA-induced changes in mitochondrial uncoupling was low in the hypothyroid and euthyroid states but became more relevant in the hyperthyroid state at the highest concentration of FFA.

c-FLIP efficiently rescues TRAF-2-/- cells from TNF-induced apoptosis

For the past 20 years, it has been known that preparations of Tumor Necrosis Factor alpha (TNF) fail to induce apoptosis due to cytoprotective responses that render cells resistant to its cytotoxic activity. Here we show that TRAF-2-/- embryonic fibroblasts express reduced levels of the anti-apoptotic molecule c-FLIP due to extensive degradation of the protein. Reconstitution of TRAF-2-/- EF with c-FLIP is sufficient for resistance to TNF toxicity. Our results strengthen the role of c-FLIP in protecting cells from the cytotoxic effect of TNF and have implication for the treatment of inflammatory and proliferative disorders.

Uncoupling protein-3 is a molecular determinant for the regulation of resting metabolic rate by thyroid hormone

Thyroid hormones increase energy expenditure, partly by reducing metabolic efficiency. The control of specific genes at the transcriptional level is thought to be the major molecular mechanism. However, both the number and the identity of the thyroid hormone-controlled genes remain unknown, as do their relative contributions. Uncoupling protein-3, a recently identified member of the mitochondrial transporter superfamily and one that is predominantly expressed in skeletal muscle, has the potential to be a molecular determinant for thyroid thermogenesis. However, changes in mitochondrial proton conductance and resting metabolic rate after physiologically mediated changes in uncoupling protein-3 levels have not been described. Here, in a study on hypothyroid rats given a single injection of T(3), we describe a strict correlation in terms of time course between the induced increase in uncoupling protein-3 expression (at mRNA and protein levels) and decrease in mitochondrial respiratory efficiency, on the one hand, and the increase in resting metabolic rate, on the other. First, we describe our finding that uncoupling protein-3 is present and regulated by T(3) only in metabolically relevant tissues (such as skeletal muscle and heart). Second, we follow the time course (at 0, 6, 12, 24, 48, 65, 96, and 144 h) of both uncoupling protein-3 mRNA levels and mitochondrial uncoupling protein-3 density in gastrocnemius muscle and heart. In both tissues, the maximal (12-fold) increase in uncoupling protein-3 density was reached at 65 h. The resting metabolic rate [lO(2)(kg(0.75))(-1)h(-1)] showed the same time course, and at 65 h the increase vs. time zero was 45% (1.316 +/- 0.026 vs. 0.940 +/- 0.007; P < 0.001). At the same time point, gastrocnemius muscle mitochondria showed a significantly higher nonphosphorylating respiration rate (nanoatoms of oxygen per min/mg protein; increase vs. time zero, 40%; 118 +/- 4 vs. 85 +/- 9; P < 0.05), whereas the membrane potential decreased by 8% (168 +/- 2 vs. 182 +/- 4; P < 0.05). These data are diagnostic of mitochondrial uncoupling. The results reported here provide the first direct in vivo evidence that uncoupling protein-3 has the potential to act as a molecular determinant in the regulation of resting metabolic rate by T(3).

An appraisal of magnetic resonance imaging of the wrist in rheumatoid arthritis

OBJECTIVES

To evaluate the role of magnetic resonance imaging (MRI) in the diagnosis, staging, and follow-up of the rheumatoid wrist.

METHODS

A Medline search was performed to identify all publications from the years 1985 to 1999 concerning MRI of the wrist in patients with rheumatoid arthritis (RA). Additional papers were retrieved by scanning the references to the Medline-listed articles. Details of the MRI technique, as well as clinical data, were analyzed and compared.

RESULTS

A total of 55 papers were identified. There were considerable variations in imaging sequence, section type, and slice thickness. Erosions and synovitis were the conditions that mostly profited from the adoption of MRI. Although the visualization of erosions was better detailed with MRI than with conventional radiography, erosions were only rarely related to clinical and laboratory parameters. Another advantage was that synovitis imaging, which can be enhanced by contrast agents, was amenable to quantitation. The extent of the synovial surface and the rate of contrast enhancement in a series of consecutive, rapidly acquired images were the most common measures.

CONCLUSIONS

MRI of the rheumatoid wrist is a useful technique to ascertain the criteria for diagnosis and progression of RA, and to monitor the effects of treatment. Implementation of a standardized protocol could further increase its value.