Anatomy of the deep fascia of the upper limb. Second part: study of innervation

Analysis of specimens taken from different areas of the deep fascia in 20 upper limbs was made in order to establish which kind of nerve fibres and endings are present in the deep muscular fascia. The flexor retinaculum and the lacertus fibrosus were also evaluated because they are anatomically hardly separable from the deep muscular fascia, although they have different functions. In particular, specimens were taken at the level of: (a) the expansion of pectoralis major onto the bicipital fascia, (b) the middle third of the brachial fascia, (c) the lacertus fibrosus, (d) the middle third of the antebrachial fascia, (e) the flexor retinaculum. This study demonstrated an abundant innervation of the fascia consisting in both free nerve endings and encapsulated receptors, in particular, Ruffini and Pacini corpuscles. However, differences in innervation were verified: the flexor retinaculum was resulted the more innervated element whilst lacertus fibrosus and the pectoralis major expansion the less innervated. These results suggest that the retinaculum has more a perceptive function whereas the tendinous expansions onto the fascia have mostly a mechanical role in the transmission of tension. The hypothesis that the fascia plays an important role in proprioception, especially dynamic proprioception, is therefore advanced. In fact, the fascia is a membrane that extends throughout the whole body and numerous muscular expansions maintain it in a basal tension. During a muscular contraction these expansions could also transmit the effect of the stretch to a specific area of the fascia, stimulating the proprioceptors in that area.

Activated T cells sustain myeloid-derived suppressor cell-mediated immune suppression

The expansion of myeloid derived suppressor cells (MDSCs), a suppressive population able to hamper the immune response against cancer, correlates with tumor progression and overall survival in several cancer types. We have previously shown that MDSCs can be induced in vitro from precursors present in the bone marrow and observed that these cells are able to actively proliferate in the presence of activated T cells, whose activation level is critical to drive the suppressive activity of MDSCs. Here we investigated at molecular level the mechanisms involved in the interplay between MDSCs and activated T cells. We found that activated T cells secrete IL-10 following interaction with MDSCs which, in turn, activates STAT3 phosphorylation on MDSCs then leading to B7-H1 expression. We also demonstrated that B7-H1⁺ MDSCs are responsible for immune suppression through a mechanism involving ARG-1 and IDO expression. Finally, we show that the expression of ligands B7-H1 and MHC class II both on in vitro-induced MDSCs and on MDSCs in the tumor microenvironment of cancer patients is paralleled by an increased expression of their respective receptors PD-1 and LAG-3 on T cells, two inhibitory molecules associated with T cell dysfunction. These findings highlight key molecules and interactions responsible for the extensive cross-talk between MDSCs and activated T cells that are at the basis of immune suppression.

Infrapatellar Fat Pad Gene Expression and Protein Production in Patients with and without Osteoarthritis

Osteoarthritis (OA) is one of the most common joint disorders. Evidence suggests that the infrapatellar fat pad (IFP) is directly involved in OA pathology. However, a comparison between OA versus non-OA IFP is still missing. Thus, the aim of this study was to compare IFP molecular, adipocytes and extracellular matrix characteristics of patients affected by OA, and patients undergoing anterior cruciate ligament (ACL) reconstruction. We hypothesized that not only inflammation but also changes in adipocytes and extracellular matrix (ECM) composition might be involved in OA pathogenesis. Fifty-three patients were enrolled. IFP biopsies were obtained, evaluating: (a) lymphocytic infiltration and vascularization; (b) adipocytes area and number; (c) adipo-cytokines and extracellular matrix gene expression levels; (d) IL-6 and VEGF protein production; (e) collagen fibers distribution. OA IFP was more inflamed and vascularized compared to ACL IFP. OA IFP adipocytes were larger and numerically lower (1.3-fold) than ACL IFP adipocytes. An increase of gene expression of typical white adipose tissue genes was observed in OA compared to ACL IFP. Collagen-types distribution was different in the OA IFP group compared to controls, possibly explaining the change of the biomechanical characteristics found in OA IFP. Statistical linear models revealed that the adipocyte area correlated with BMI in the OA group. In conclusion, inflammation and fibrotic changes of OA IFP could represent novel therapeutic targets to counteract OA.

Inflammatory molecules produced by meniscus and synovium in early and end-stage osteoarthritis: a coculture study

The aim of this study was to identify the molecules and pathways involved in the cross-talk between meniscus and synovium that may play a critical role in osteoarthritis (OA) pathophysiology. Samples of synovium and meniscus were collected from patients with early and end-stage OA and cultured alone or cocultured. Cytokines, chemokines, metalloproteases, and their inhibitors were evaluated at the gene and protein levels. The extracellular matrix (ECM) changes were also investigated. In early OA cultures, higher levels of interleukin-6 (IL-6) and IL-8 messenger RNA were expressed by synovium and meniscus in coculture compared with meniscus cultured alone. RANTES release was significantly increased when the two tissues were cocultured compared with meniscus cultured alone. Increased levels of matrix metalloproteinase-3 (MMP-3) and MMP-10 proteins, as well as increased release of glycosaminoglycans and aggrecan CS846 epitope, were observed when synovium was cocultured with meniscus. In end-stage OA cultures, increased levels of IL-8 and monocyte chemoattractant protein-1 (MCP-1) proteins were released in cocultures compared with cultures of meniscus alone. Chemokine (C-C motif) ligand 21 (CCL21) protein release was higher in meniscus cultured alone and in coculture compared with synovium cultured alone. Increased levels of MMP-3 and 10 proteins were observed when tissues were cocultured compared with meniscus cultured alone. Aggrecan CS846 epitope release was increased in cocultures compared with cultures of either tissue cultured alone. Our study showed the production of inflammatory molecules by synovium and meniscus which could trigger inflammatory signals in early OA patients, and induce ECM loss in the progressive and final stages of OA pathology.

Conditioned media from human osteoarthritic synovium induces inflammation in a synoviocyte cell line

AIM

Osteoarthritis (OA) is a whole joint pathology involving cartilage, synovial membrane, meniscus, subchondral bone, and infrapatellar fat pad (IFP). Synovitis has been widely documented in OA suggesting its important role in pathogenesis. The aim of this study was to investigate the role of different joint tissues in promoting synovitis.

MATERIALS AND METHODS

Conditioned media (CM) from cartilage, synovial membrane, meniscus, and IFP were generated from tissues of five patients undergoing total knee replacement and used to stimulate a human fibroblast-like synoviocytes cell line (K4IM). Cytokines, chemokines, and metalloproteases release was analyzed in all CM by Bio-Plex Assay and sulfated glycosaminoglycan (GAG) content by dimethylmethylene blue assay. Gene expression of several markers was evaluated by real-time PCR in K4IM cells stimulated with the CM obtained from joint tissues.

RESULTS

CM from all tissues produced high levels of IL-6, IL-8, and CCL2. CCL21, MMP-3, and -13 levels were detected in all CM except IFP. MMP-10 was present only in CM of cartilage and synovial tissues. IL-1β, IL-15, TNF-α, CCL5, and CCL19 were undetectable. However, only K4IM cells stimulated by the CM from OA synovium showed an increase of IL-6, CXCL-8, CCL21, MMP10, and IL-1β expression.

CONCLUSION

Our study showed that K4IM might be a suitable in vitro model for evaluating different cellular pathways in OA studies. Importantly, we demonstrated that in OA, all joint tissues might be involved in the progression of synovitis with a predominant role of synovial membrane itself compared to the other joint tissues.

High-density lipoproteins downregulate CCL2 production in human fibroblast-like synoviocytes stimulated by urate crystals

Introduction

To investigate whether monosodium urate (MSU) crystals induce the production of CCL2 (monocyte chemoattractant protein-1; MCP-1) in human fibroblast-like synoviocytes (FLS) and whether this mechanism would be affected by high-density lipoproteins (HDL).

Methods

Human FLS isolated from synovial tissue explants were stimulated with MSU crystals (0.01 to 0.5 mg/ml) or interleukin (IL)-1β (10 pg/ml) in the presence or absence of HDL (50 and 100 μg/ml). The production and expression of CCL2 was evaluated with ELISA, confocal microscopy, immunofluorescence microscopy, chemotaxis assay, and real-time quantitative PCR.

Results

Exposure of FLS to MSU crystals induced CCL2 accumulation in culture medium in a dose- and time-dependent manner, reaching a plateau at 50 to 75 μg/ml MSU crystals and 20 to 24 hours. Although low, the induced CCL2 levels were sufficient to trigger mononuclear cell migration. In resting FLS, CCL2 was localized in small cytoplasmic vesicles whose number diminished with MSU crystal stimulation. Concomitantly, MSU crystals triggered the induction of CCL2 mRNA expression. All these processes were inhibited by HDL, which cause a 50% decrease in CCL2 mRNA levels and a dose-dependent inhibition of the release of CCL2. Similar results were obtained when FLS were pretreated with HDL and washed before activation by MSU crystals or IL-1β, suggesting a direct effect of HDL on the FLS activation state.

Conclusions

The present results demonstrate that MSU crystals induce FLS to release CCL2 that is stored in vesicles in resting conditions. This mechanism is inhibited by HDL, which may limit the inflammatory process by diminishing CCL2 production and, in turn, monocytes/macrophages recruitment in joints. This study confirms the antiinflammatory functions of HDL, which might play a part in the limitation of acute gout attack.

Influence of glucosamine sulphate on oxidative stress in human osteoarthritic chondrocytes: effects on HO-1, p22(Phox) and iNOS expression

OBJECTIVE

Reactive oxygen species (ROS) are major determinants in the alteration of articular cartilage. Among protective cellular mechanisms, the inducible isoform of haem oxygenase (HO-1) plays a particularly relevant role. On the other hand, the enzymatic activity of the Nicotinamide adenine dinucleotide phosphate (NADPH) system could contribute to the generation of ROS. Glucosamine sulphate (GS) is one of the drugs used in the treatment of osteoarthritis; however, its mechanism of action is still largely unknown. The aim of the present study was to investigate the effects of GS on primary human chondrocytes in vitro, in particular with regard to HO-1, p22(Phox) (a subunit of NADPH complex) and inducible nitric oxide synthase (iNOS) expression.

METHODS

Primary human chondrocytes were treated with different concentrations of GS; gene expression of HO-1, p22(Phox) and iNOS was assessed by the reverse transcriptase-polymerase chain reaction method. In a separate set of experiments, the cells were stimulated with human recombinant interleukin (IL)-1beta and simultaneously treated with GS. Moreover, HO-1 protein and total nitrite production were evaluated.

RESULTS

HO-1 gene expression was up-regulated (+40% with respect to the controls, P < 0.001) by 10 mmol/l GS at 24 h, while p22(Phox) gene expression was down-regulated by 10 mmol/l GS with a maximum inhibitory effect observed after 48 h treatment. IL-1beta stimulation induced expression of iNOS reverted by 1 and 10 mmol/l GS. Moreover, HO-1 gene expression was down-regulated by IL-1beta and 10 mmol/l GS restored baseline values. These data were confirmed by evaluating HO-1 protein level and nitrite production.

CONCLUSIONS

The influence of GS on oxidative stress observed in this study discloses a possible new mechanism of action and seems to be in keeping with a potential protective effect on chondrocyte population.

Infrapatellar Fat Pad Stem Cells Responsiveness to Microenvironment in Osteoarthritis: From Morphology to Function

Recently, infrapatellar fat pad (IFP) has been considered as a source of stem cells for cartilage regeneration in osteoarthritis (OA) due to their ability for differentiation into chondrocytes. However, stressful conditions, like that related to OA, may induce a pathogenic reprograming. The aim of this study was to characterize the structural and functional properties of a new population of stem cells isolated from osteoarthritic infrapatellar fat pad (OA-IFP). Nine OA patients undergoing total knee arthroplasty (TKA) were enrolled in this study [median age = 74 years, interquartile range (IQR) = 78.25-67.7; median body mass index = 29.4 Kg/m², IQR = 31.7-27.4]. OA-IFP stem cells were isolated and characterized for morphology, stemness, metabolic profile and multi-differentiative potential by transmission electron microscopy, flow cytometric analysis, gene expression study and cytochemistry. OA-IFP stem cells displayed a spindle-like morphology, self-renewal potential and responsiveness (CD44, CD105, VEGFR2, FGFR2, IL1R, and IL6R) to microenvironmental stimuli. Characterized by high grade of stemness (STAT3, NOTCH1, c-Myc, OCT-4, KLF4, and NANOG), the cells showed peculiar immunophenotypic properties (CD73⁺/CD39⁺/CD90⁺/CD105⁺/CD44^–/+/CD45^–). The expression of HLA-DR, CD34, Fas and FasL was indicative of a possible phenotypic reprograming induced by inflammation. Moreover, the response to mechanical stimuli together with high expression level of COL1A1 gene, suggested their possible protective response against in vivo mechanical overloading. Conversely, the low expression of CD38/NADase was indicative of their inability to counteract NAD⁺-mediated OA inflammation. Based on the ultrastructural, immunophenotypic and functional characterization, OA-IFP stem cells were hypothesized to be primed by the pathological environment and to exert incomplete protective activity from OA inflammation.

Biomechanics of Chondrocytes and Chondrons in Healthy Conditions and Osteoarthritis: A Review of the Mechanical Characterisations at the Microscale

Biomechanical studies are expanding across a variety of fields, from biomedicine to biomedical engineering. From the molecular to the system level, mechanical stimuli are crucial regulators of the development of organs and tissues, their growth and related processes such as remodelling, regeneration or disease. When dealing with cell mechanics, various experimental techniques have been developed to analyse the passive response of cells; however, cell variability and the extraction process, complex experimental procedures and different models and assumptions may affect the resulting mechanical properties. For these purposes, this review was aimed at collecting the available literature focused on experimental chondrocyte and chondron biomechanics with direct connection to their biochemical functions and activities, in order to point out important information regarding the planning of an experimental test or a comparison with the available results. In particular, this review highlighted (i) the most common experimental techniques used, (ii) the results and models adopted by different authors, (iii) a critical perspective on features that could affect the results and finally (iv) the quantification of structural and mechanical changes due to a degenerative pathology such as osteoarthritis.

In vitro response of osteoarthritic chondrocytes and fibroblast-like synoviocytes to a 500-730 kDa hyaluronan amide derivative

The aim of this study was to compare the effects of native hyaluronan (HA) with that of its hexadecylamide derivative (HYADD) on proliferation of fibroblast-like synoviocytes (FLS) and chondrocytes. The production of inflammatory and anti-inflammatory cytokines was also analyzed in FLS cultures. The proliferation of osteoarthritis (OA) chondrocytes was enhanced when cells were treated with 0.5-1.5 mg mL(-1) of HA or HYADD®4-G. This effect was completely suppressed by the anti-CD44 antibody. At 0.5 to 1 mg mL(-1) , HA and HYADD®4-G did not influence the proliferation of normal or pathological FLS; however, at the higher concentration (1.5 mg mL(-1) ), HYADD®4-G did significantly inhibit cell proliferation. As to effects on inflammation, a significant increase in the expression of the IL-10 gene was observed when FLS were pretreated with tumor necrosis factor alpha and then cultured in the presence of 0.5 mg mL(-1) HYADD® 4-G or HA. The effects of HA derivatives on FLS proliferation and production of anti-inflammatory cytokines indicate that they may be of therapeutic benefit in OA. The longer residence time in the joint cavity, the increased viscoelasticity, and the anti-inflammatory potential of HYADD®4-G make it a better candidate than native HA for OA therapy.

Challenging Surgical Treatment of Displaced Articular Tibial Plateau Fractures: Do Early Knee Radiographic Features Have a Predictive Value of the Mid-Term Clinical Functional Outcomes?

Objective

To evaluate mid‐term radiographic and functional outcomes of tibial plateau fracture (TPF) patients treated with the open reduction internal fixation (ORIF) technique and to find predictive factors of clinical outcomes.

Methods

A retrospective, single‐center study was performed enrolling a consecutive series of patients with diagnosis of TPF. All subjects were treated by ORIF between January 2010 and December 2015 at our level‐1 healthcare trauma center. The inclusion criteria were: age between 18 and 75 years; ORIF technique used for articular TPF, type 41‐B and 41‐C, isolated or with associated injuries. The patients were divided in two groups, according to fracture patterns and compared. Their characteristics, radiographic and clinical outcomes were recorded. Radiographs 12 months after surgery were evaluated for reduction and alignment, and radiographs at 24 months to describe post‐traumatic osteoarthritis (PTOA). Functional outcomes were assessed using the visual analog scale (VAS), the Short Form 36 (SF‐36), the knee injury and osteoarthritis outcome score (KOOS), and the American Knee Society score (AKSS) questionnaires. Return to work and sport activities were also investigated. Univariate and multivariate analysis were performed, and the statistical significance was defined as two‐tailed P < 0.05.

Results

Forty‐five patients were included, 29 males and 16 females; the mean age was 54.5 years. The mean follow‐up was 57.18 months (range, 26–94). There were AO 41‐B fractures (partial articular fractures) in more than half of the patients (66.67%), while the remaining 15 had AO 41‐C fractures (complete articular fractures). The sub‐type AO 41‐B3 was the most common, reported in 62.22% of patients. The mean KOOS score was 69.0. Mean AKSS and SF‐36 PCS scores were 79.0 and 41.4, respectively. There were significant relationships between age and functional results (KOOS ADL, Sport, QoL, and SF‐36 PCS) and between BMI and KOOS Pain, ADL, Sport, and QoL. No differences were found between the two types of fractures regarding quality of reduction and alignment. AO 41‐C TPF tend to develop PTOA more frequently with respect to 41‐B fractures, while type AO 41‐C TPF had the worst clinical outcomes. We found that the presence of an articular step‐off and the malalignment of the tibial axis after surgery were predictive of daily pain felt by patients. PTOA was predictive of a worse AKSS. The overall complication rate was 13.33%: 1 superficial wound infection, 1 deep vein thrombosis, and 4 cases of transitory deficit of the common peroneal nerve.

Conclusion

The present study demonstrates that early radiographic features may be predictive for pain perceived by patients at mid‐term follow‐up.

The Lumbar Interspinous Ligaments in Humans: Anatomical Study and Review of the Literature

In textbooks of human anatomy and atlases of spinal surgery, the lumbar interspinous ligaments are described and illustrated in various and often conflicting ways. Thirty-four lumbar vertebral columns (19 males, 15 females, range 17-92 years old), sampled at autopsy, were studied by dissection and macroscopic analysis. The orientation of the fibre bundles was evaluated in the sagittal plane by tracing a reference line parallel to the cranial border of the spinous process, and the degree of bundle tilting with reference to this line was measured in the ventral, middle and dorsal parts of the ligament. Histological and immunohistochemical (anti-S100) studies of the ligaments, on sagittal, frontal, and transversal planes, were also carried out. In vivo radiological validation was performed in 25 patients by MR and CT imaging. Macroscopically, the interspinous ligaments are consistently composed of bundles of fibres arranged in a characteristic pattern. Together, they present an oblique orientation from anterior to posterior in a caudal-cranial direction. In their ventral part the bundles form a slight curve with a posterior-inferior concavity. In the middle part, the bundles are thicker and arranged in an italic S shape with a mean degree of tilting of 52 +/- 14, 21 +/- 12 and 50 +/- 17 in the anterior, intermediate and posterior subzones of the L2-L3 ligaments and of 32 +/- 14, 11 +/- 9 and 18 +/- 11 in the anterior, intermediate and posterior subzones of the L4-L5 level. The dorsal part consists of obliquely ascending bundles of fibres mostly converging in the supraspinous ligament. Histologically, these ligaments are mainly composed of collagen fibres, whereas the elastic fibres are ubiquitous, although mostly concentrated in the ventral part, which is closely linked to the yellow ligament. The interspinous ligament is well supplied by small blood vessels and sensory nerves, the latter particularly in its dorsal part and on its lateral surfaces. According to collected data, the structure of the interspinous ligaments reflects their function, i.e., the italic S-shaped course of the fibrous bundles represents an available reserve of length in a poorly elastic ligament.

Tryptophan catabolism in synovial fluid of various arthropathies and its relationship with inflammatory cytokines

Synovial fluids (SF) from patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA), gout, and osteoarthritis (OA) were investigated for the levels of interleukin (IL)-1 beta, IL-6 and IL-8, tryptophan (Trp) and indoleamine 2,3-dioxygenase (IDO) activity. Significant differences exist in the levels of IL-1 beta between inflammatory arthritides RA, PsA and gout and non inflammatory arthritis, such as OA. The highest concentration of IL-1 beta was found in RA, that showed high levels also of IL-6 and IL-8. In the same disease we also found the highest IDO activity and the lowest Trp concentration. In addition, IDO activity seems to be related with the decrease in Trp, as demonstrated by the inverse correlation found between these two substances in the SF of all patients.

Mechanical behavior of infrapatellar fat pad of patients affected by osteoarthritis

The infrapatellar fat pad (IFP) is an adipose tissue present in the knee that lies between the patella, femur, meniscus and tibia, filling the space between these structures. IFP facilitates the distribution of the synovial fluid and may act to absorb impulsive actions generated through the joint. IFP in osteoarthritis (OA) pathology undergoes structural changes characterized by inflammation, hypertrophy and fibrosis. The aim of the present study is to analyze the mechanical behavior of the IFP in patients affected by end-stage OA. A specific test fixture was designed and indentation tests were performed on IFP specimens harvested from OA patients who underwent total knee arthroplasty. Experiments allowed to assess the typical features of mechanical response, such as non-linear stress-strain behavior and time-dependent effects. Results from mechanical experimentations were implemented within the framework of a visco-hyperelastic constitutive theory, with the aim to provide data for computational modelling of OA IFP role in knee mechanics. Initial and final indentation stiffness were calculated for all subjects and statistical results reveled that OA IFP mechanics was not significantly influenced by gender, BMI and sample preparation. OA IFP mechanical behavior was also compared to that of other adipose tissues. OA IFP appeared to be a stiffer adipose tissue compared to subcutaneous, visceral adipose tissues and heel fat pads. It is reasonable that fibrosis induces a modification of the tissue destabilizing the normal distribution of forces in the joint during movement, causing a worsening of the disease.

Mid-Term Outcomes after Arthroscopic "Tear Completion Repair" of Partial Thickness Rotator Cuff Tears

Background and Objectives: Different arthroscopic procedures are used for partial-thickness rotator cuff tears (PT-RCTs), but there is still no evidence on the superiority of one procedure over the other. The aim of this study was to evaluate the clinical outcomes and the rate of complications of a tear completion repair (TCR) technique. Materials and Methods: Patients who had undergone arthroscopic TCR technique for PT-RCTs with a follow-up of at least 2-years after surgery were included. The TCR technique involved the removal of the "critical zone" and creating microfractures to biologically support tendon healing. Functional outcomes were assessed prospectively by the Constant score (CS) and active and passive range of movement (ROM). Pain and patient satisfaction were measured using a visual analog scale (VAS). Complication rates were recorded, and tendon integrity was assessed with magnetic resonance imaging (MRI) or ultrasound performed at least 2-years after surgery. Results: Eighty-seven patients with a median age of 57 years were followed-up for a median of 5 years. The CS score improved from 53.5 preoperatively to 94.0 postoperatively (p < 0.001). Median VAS score decreased from 8.6 to 1.0 (p < 0.0001). Median patient satisfaction was 9.3. The overall complication rate was 14.9%. Conclusions: Patients with PT-RCTs of the supraspinatus tendon treated by the TCR technique with "critical zone" removal and biological stimulation by microfractures showed good functional results with excellent strength recovery, a high degree of patient satisfaction, and resolution of painful symptoms at mid-term follow-up.

Pro-inflammatory interleukins in the synovial fluid of rheumatoid arthritis associated with joint hypermobility

BACKGROUND

Joint hypermobility (JH) is frequently seen in rheumatology; in some cases, such as rheumatoid arthritis (RA), it may represent a worsening of disease evolution. The aim of our study was to evaluate the influence of joint hypermobility on RA synovial fluid (SF) inflammation. Patients and methods. One hundred consecutive adult patients with RA and joint effusion of the knee were examined for the presence of JH. In the SF we evaluated volume, the number of white blood cells (WBC) and the levels of interleukin (IL)-1beta, IL-6 and IL-8 and prostaglandin E2 (PGE2).

RESULTS

JH was associated with RA (JH-RA) in 18 patients, all of whom were female. Compared with non-JH RA, all the SF indices found in JH-RA were higher, although significant differences were observed only for volume, IL-8 and PGE2.

CONCLUSION

In JH-RA, increased joint mobility seems to be associated with a more severe local inflammatory response, which may contribute to the more erosive evolution observed in our patients.

Defective excitation-contraction coupling and mitochondrial respiration precede mitochondrial Ca2+ accumulation in spinobulbar muscular atrophy skeletal muscle

Polyglutamine expansion in the androgen receptor (AR) causes spinobulbar muscular atrophy (SBMA). Skeletal muscle is a primary site of toxicity; however, the current understanding of the early pathological processes that occur and how they unfold during disease progression remains limited. Using transgenic and knock-in mice and patient-derived muscle biopsies, we show that SBMA mice in the presymptomatic stage develop a respiratory defect matching defective expression of genes involved in excitation-contraction coupling (ECC), altered contraction dynamics, and increased fatigue. These processes are followed by stimulus-dependent accumulation of calcium into mitochondria and structural disorganization of the muscle triads. Deregulation of expression of ECC genes is concomitant with sexual maturity and androgen raise in the serum. Consistent with the androgen-dependent nature of these alterations, surgical castration and AR silencing alleviate the early and late pathological processes. These observations show that ECC deregulation and defective mitochondrial respiration are early but reversible events followed by altered muscle force, calcium dyshomeostasis, and dismantling of triad structure.

Metal Ion Release, Clinical and Radiological Outcomes in Large Diameter Metal-on-Metal Total Hip Arthroplasty at Long-Term Follow-Up

Total hip arthroplasty (THA) with metal-on-metal (MoM) bearings have shown problems of biocompatibility linked to metal ion release at the local level causing an adverse reaction to metal debris (ARMD) and at a systemic level. The aim of this study was to evaluate clinical and radiological outcomes, and metal ion concentrations in the blood and urine of patients who underwent THA with the LIMA Met-Met hip system. Patients with ceramic-on-ceramic (CoC) bearings were included as a control group. In this study, 68 patients were enrolled: 34 with MoM THAs and 34 with CoC THAs. Patients were evaluated clinically (Harris Hip Score, SF-36) and radiologically at a median of 7.4 years after surgery. Whole blood and urinary cobalt and chromium levels were also assessed. Both types of implants were comparable in terms of clinical and functional results. Ion levels were significantly higher in the MoM group compared with CoC group 7 years after surgery. No correlations were found between metal ion levels and patient demographics, functional and radiological outcomes, and prosthesis features. Patient monitoring is thus advised to establish if prosthesis revision is necessary, especially in the case of MoM THA.

The Viability and Anti-Inflammatory Effects of Hyaluronic Acid-Chitlac-Tracimolone Acetonide- β-Cyclodextrin Complex on Human Chondrocytes

OBJECTIVE

To compare the effects of the complex triamcinolone acetonide-hydroxypropyl-β-cyclodextrin (TA-CD) on in vitro inflamed primary human articular chondrocytes in the presence or absence of the mixture hyaluronic acid-Chitlac, a lactose-modified chitosan (HA-CTL).

DESIGN

Changes in cell viability and pro-inflammatory cytokines gene expression were analyzed in human chondrocytes using an in vitro model of macrophage-mediated inflammation. Human monocytes U937 were differentiated to macrophages by phorbol 12-myristate 13-acetate (PMA) and lipopolysaccharides (LPS). The anti-inflammatory effects of the complex TA-CD and HA-CTL mixture were assessed on chondrocytes exposed for 24 hours to U937 conditioned medium (CM), by quantitative polymerase chain reaction analysis.

RESULTS

The TA-CD viability was enhanced by the presence of the HA-CTL mixture in chondrocyte cultures. The exposure of cells to CM significantly increased interleukin-1β and interleukin-6 gene expression, and when the complex TA-CD was added to the inflamed cells, gene transcription of cytokines was restored to near baseline values, both in the presence or in the absence of HA-CTL mixture.

CONCLUSION

The addition of HA-CTL mixture significantly attenuated cytotoxicity induced by TA and preserved the anti-inflammatory effects, thus confirming the chondroprotective role of the HA-CTL mixture.

Macroscopic Synovial Inflammation Correlates with Symptoms and Cartilage Lesions in Patients Undergoing Arthroscopic Partial Meniscectomy: A Clinical Study

Background: The aim of the study was to examine the relationship among patients’ characteristics, intraoperative pathology and pre/post-operative symptoms in a cohort of patients undergoing arthroscopic partial meniscectomy for symptomatic meniscal tears. Methods: Clinical data were collected (age, sex, body mass index, time to surgery, trauma). Intraoperative cartilage pathology was assessed with Outerbridge score. Meniscal tears were graded with the ISAKOS classification. Synovial inflammation was scored using the Macro-score. Patient symptoms were assessed pre/post-operatively using the KOOS instrument. Results: In the series of 109 patients (median age 47 years), 50% of the meniscal tears were traumatic; 85% of patients showed mild to moderate synovitis; 52 (47.7%) patients had multiple cartilage defects and 31 (28.4%) exhibited a single focal chondral lesion. Outerbridge scores significantly correlated with patient age, BMI and synovial inflammation. There was a correlation between severity of chondral pathology and high-grade synovial hyperplasia. Pre-operative KOOS correlated with BMI, meniscal degenerative changes and symptom duration. Obesity, time to surgery, presence of high-grade synovial hyperplasia and high-grade cartilage lesions were independent predictors of worse post-operative pain and function. Conclusion: We demonstrated that pre-operative symptoms and post-operative outcomes correlate with synovitis severity and cartilage pathology, particularly in old and obese patients that underwent arthroscopic partial meniscectomy. Importantly, patients with a degenerative meniscal pattern and with longer time to surgery experienced more severe cartilage damage and, consequentially, pain and dysfunction. These findings are fundamental to identify patients suitable for earlier interventions.

[Synoviocyte cultures from synovial fluid]

The study of the pathogenetic mechanisms of rheumatic diseases is in general carried out through "in vitro" systems based on cellular cultures models. The difficulties to achieve fresh human tissue prompted us to develop a simpler method to obtain fibroblast-like synovial cells from synovial fluid (SF).

METHODS

SF was collected from the knees of 5 patients with rheumatoid arthritis (RA), 4 with osteoarthritis (OA) and 5 with psoriatic arthritis (PsA). The pellet obtained after centrifugation was resuspended in DMEM/HamF12 containing 10% foetal calf serum, 1% peni-streptomycin, 4 ng/ml of fibroblast grow factor and incubated at 37 degrees C in T25 culture flasks. Synoviocytes were also obtained from fresh synovial membranes (SM) by explants technique. Both types of cells were characterized by immunocytochemistry and their inflammatory response to synthetic monosodium urate crystals was studied through the measurement of nitric oxide (NO).

RESULTS

Adherent synoviocytes were obtained from the culture of 2/5 SF from RA, 4/4 SF from OA and 5/5 SF from PsA. Synoviocytes isolated from both SF and SM expressed surface antigens CD90, CD55, and the intracellular prolyl-4-hydroxylase. Morphologically, the cells showed the typical spindle-shape fibroblast-like appearance. NO levels induced by UMS crystals in SF synoviocytes were similar to those obtained in SM synoviocytes.

CONCLUSION

Adherent cells obtained from SF showed the phenotype and the reactivity of tissue synoviocytes. Due to the easy accessibility of SF, this method may represents an useful alternative when synovial tissues is not promptly available.

Human MDSCs derived from the bone marrow maintain their functional ability but have a reduced frequency of induction in the elderly compared to pediatric donors

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immunosuppressive cells developing from myeloid progenitors, which are enriched in pathological conditions such as cancer, and are known to inhibit the functions of effector T cells. During aging, several changes occur both at the adaptive and innate immune system level, in a process defined as immunoscenescence. In particular, the low-grade inflammation state observed in the elderly appears to affect hematopoiesis. We previously demonstrated that the combination of GM-CSF and G-CSF drives the in vitro generation of bone marrow-derived MDSCs (BM-MDSCs) from precursors present in human bone marrow aspirates of healthy donors, and that these cells are endowed with a strong immune suppressive ability, resembling that of cancer-associated MDSCs. In the present work we investigated BM-MDSCs induction and functional ability in a cohort of pediatric versus elderly donors. To this aim, we analyzed the differences in maturation stages and ability to suppress T cell proliferation. We found that the ex vivo distribution of myeloid progenitors is similar between pediatric and elderly individuals, whereas after cytokine treatment a significant reduction in the more immature compartment is observed in the elderly. Despite the decreased frequency, BM-MDSCs maintain their suppressive capacity in aged donors. Taken together, these results indicate that in vitro induction of MDSCs from the BM is reduced with aging and opens new hypotheses on the role of age-related processes in myelopoiesis.

Variations in contents of hyaluronan in the peritumoral micro-environment of human chondrosarcoma

A concept consolidated in recent years is that tumor growth depends to a great extent on the micro-environment surrounding the tumor, which has a fundamental role in tumor progression and in determining the effectiveness of therapies. Our analysis focuses on chondrosarcoma, the second primary malignant bone tumor, resistant to both chemotherapeutic and radiation therapy. We quantified hyaluronan, one of the main components of the extracellular matrix, with the aim of comparing its amount in the connective tissue surrounding the tumor with intra-tumoral tissue and healthy fascia of the same anatomic district, viewed as a health control. We demonstrate that hyaluronan increased significantly in the peritumoral stroma compared with the healthy fascia, which showed an average amount according to the physical characteristics of body districts by a mean value of 26.9 μg/g. In the peritumoral stroma, the mean hyaluronan content reached 132.6 μg/g (mean value of 63.2 μg/g). The p-value was less than 0.01, showing a highly significant statistical difference. Surprisingly, no significant differences were detected as a function of age, gender, or tumor grade. The levels of hyaluronan were comparable in peritumoral and tumor tissues, although there were differences depending on the state of necrosis. In addition, data on the expression of hyaluronic acid synthetase showed a decrease of about 50% in peritumoral and tumor tissues, indicating alterations in hyaluronan turnover and synthesis. This work demonstrates a variation in hyaluronan contents around the chondrosarcoma, likely correlated with the aggressiveness and resistance to chemotherapy of this tumors. Statement of Clinical Significance: Deeper knowledge about the composition of the peritumoral stroma, rich in extracellular matrix, will enhance better study and understanding of the metastatic potential of tumors and their prognostic indices. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:503-509, 2019.

Psoriatic arthritis exacerbated by Salmonella infection

Psoriatic arthritis (PsA) is an inflammatory joint disease in which environmental factors, particularly trauma and infections, are thought to play an important role. The authors describe the case of a patient with a mild and long-untreated form of PsA which was severely exacerbated by Salmonella typhimurium infection. This case confirms the importance of infectious agents in the occurrence and course of PsA.