Crucial role of the terminal complement complex in chondrocyte death and hypertrophy after cartilage trauma.

OBJECTIVE: Innate immune response and particularly terminal complement complex (TCC) deposition are thought to be involved in the pathogenesis of posttraumatic osteoarthritis. However, the possible role of TCC in regulated cell death as well as chondrocyte hypertrophy and senescence has not been unraveled so far and was first addressed using an ex vivo human cartilage trauma-model. DESIGN: Cartilage explants were subjected to blunt impact (0.59 J) and exposed to human serum (HS) and cartilage homogenate (HG) with or without different potential therapeutics: RIPK1-inhibitor Necrostatin-1 (Nec), caspase-inhibitor zVAD, antioxidant N-acetyl cysteine (NAC) and TCC-inhibitors aurintricarboxylic acid (ATA) and clusterin (CLU). Cell death and hypertrophy/senescence-associated markers were evaluated on mRNA and protein level. RESULTS: Addition of HS resulted in significantly enhanced TCC deposition on chondrocytes and decrease of cell viability after trauma. This effect was potentiated by HG and was associated with expression of RIPK3, MLKL and CASP8. Cytotoxicity of HS could be prevented by heat-inactivation or specific inhibitors, whereby combination of Nec and zVAD as well as ATA exhibited highest cell protection. Moreover, HS+HG exposition enhanced the gene expression of CXCL1, IL-8, RUNX2 and VEGFA as well as secretion of IL-6 after cartilage trauma. CONCLUSIONS: Our findings imply crucial involvement of the complement system and primarily TCC in regulated cell death and phenotypic changes of chondrocytes after cartilage trauma. Inhibition of TCC formation or downstream signaling largely modified serum-induced pathophysiologic effects and might therefore represent a therapeutic target to maintain the survival and chondrogenic character of cartilage cells.

The functional role of chondrogenic stem/progenitor cells: novel evidence for immunomodulatory properties and regenerative potential after cartilage injury.

Considering the poor intrinsic healing potential of articular cartilage, resident chondrogenic stem/progenitor cells (CSPCs) have gained attention in recent years. Although, CSPCs are attracted by a cartilage injury, knowledge about the post-traumatic behaviour and functional role of this cell population is fairly basic. The present study, not only elaborated on the regenerative capacities of CSPCs, but also illuminated potential immunomodulatory properties after cartilage trauma. Estimation of the CSPC population size within previously impacted cartilage explants by flow-cytometry revealed an increased percentage of CSPC-marker positive cells as compared to unimpacted tissue. In line with this, proliferation, chemotactic migration and in vitro wound healing activity of isolated CSPCs was similarly enhanced after stimulation with trauma-conditioned (TC) medium. Further, a significant increase in pro- and anti-inflammatory gene expression, as well as IL-6 secretion due to TC-medium-stimulation was measured. In this context, antioxidative or chondroanabolic therapeutic intervention alleviated the post-traumatic response of TC-medium-activated CSPCs and substantially influenced CSPC chondrogenic differentiation in different ways. Overall, this study provided novel insights concerning the functional role of CSPCs after cartilage trauma and the effects of a therapeutic intervention in order to improve regenerative processes and prevent cartilage degeneration following trauma.

Osteoarthritis-patterns, cardio-metabolic risk factors and risk of all-cause mortality: 20 years follow-up in patients after hip or knee replacement.

Osteoarthritis (OA) is a common musculoskeletal disorder and occur in different patterns. However, its impact on long-term all-cause-mortality is inconclusive. STUDY AIMS: Investigate 20-year all-cause-mortality in patients with hip/knee arthroplasty (recruited 1995/1996, N = 809) from the Ulm Osteoarthritis Study-cohort, in comparison to general population. Furthermore, to enlighten the triangle between baseline life-style and cardio-metabolic risk factors, phenotypic OA-patterns (laterality, generalization, cause) and all-cause-mortality. Mortality was assessed during 20 years follow-up. Standardized mortality ratios (SMR), adjusted odds ratios and hazard ratios (aHR) were calculated. After five years cohort-mortality was reduced compared to the general population, however 20 years later assimilated (SMR = 1.11; 95%-CI 0.73-1.49). OA-patterns were associated with age, cholesterol, and overweight/obesity. In comparison to primary OA decreased mortality was observed for patients with secondary OA (aHR = 0.76; 95%-CI 0.61-0.95) adjusted for age, smoking, overweight/obesity, diabetes, hypertension, cardiac insufficiency, uric acid, and lower cholesterol. There was no increased mortality in patients after 20 years follow-up compared to general population. Significantly decreased mortality in secondary compared to primary OA suggests a subtype-specific involvement of systemic co-factors in determination of all-cause-mortality. Because cardio-metabolic risk factors were associated with increased risk of bilateral OA and lower long-term survival, those risk factors should be consequently targeted in OA-patients.

Mesenchymal stem cells in peripheral blood of severely injured patients.

PURPOSE: Mesenchymal stem cells (MSCs) are primarily stromal cells present in bone marrow and other tissues that are crucial for tissue regeneration and can be mobilized into peripheral blood after different types of organ damage. However, little is known about MSC appearance in blood in the setting of polytrauma. METHODS: We conducted a monocentered and longitudinal observational clinical study in 11 polytraumatized patients with an injury severity score (ISS) ≥ 24 to determine the numbers of MSCs in peripheral blood. Blood was collected from healthy volunteers and patients after polytrauma in the emergency room and 4, 12, 24, 48 h, 5 and 10 day later, and cells carrying MSC-surface markers (negative for CD45, positive for CD29, CD73, CD90, CD105, and CD166 in different combinations also employing the more stringent markers STRO1 and MSCA1) were detected and characterized using flow cytometry. Relative numbers of MSC-like cells were correlated with clinical parameters to evaluate if specific injury patterns had an influence on their presence in the blood cell pool. RESULTS: We were able to detect MSC marker-positive cells in both cohorts; however, the percentage of those cells present in the blood of patients during the first 10 day after injury was mostly similar to healthy volunteers, and significantly lowers starting at 4 h post trauma for one marker combination when compared to controls. Furthermore, the presence of a pelvis fracture was partly correlated with reduced relative numbers of MSC-like cells detectable in blood. CONCLUSIONS: Polytrauma in humans was associated with partly reduced relative numbers of MSC-like cells detected in peripheral blood in the time course after injury. Further studies need to define if this reduction was due to lower mobilization from the bone marrow or to active migration to the sites of injury.

Friction properties of a new silk fibroin scaffold for meniscal replacement.

The menisci protect the articular cartilage by reducing contact pressure in the knee. To restore their function after injury, a new silk fibroin replacement scaffold was developed. To elucidate its tribological properties, friction of the implant was tested against cartilage and glass, where the latter is typically used in tribological cartilage studies. The silk scaffold exhibited a friction coefficient against cartilage of 0.056, which is higher than meniscus against cartilage but in range of the requirements for meniscal replacements. Further, meniscus friction against glass was lower than cartilage against glass, which correlated with the surface lubricin content. Concluding, the tribological properties of the new material suggest a possible long-term chondroprotective function. In contrast, glass always produced high, non-physiological friction coefficients.

Adiponectin regulates contextual fear extinction and intrinsic excitability of dentate gyrus granule neurons through AdipoR2 receptors.

Post-traumatic stress disorder (PTSD) is characterized by exaggerated fear expression and impaired fear extinction. The underlying molecular and cellular mechanisms of PTSD are largely unknown. The current pharmacological and non-pharmacological treatments for PTSD are either ineffective or temporary with high relapse rates. Here we report that adiponectin-deficient mice exhibited normal contextual fear conditioning but displayed slower extinction learning. Infusions of adiponectin into the dentate gyrus (DG) of the hippocampus in fear-conditioned mice facilitated extinction of contextual fear. Whole-cell patch-clamp recordings in brain slices revealed that intrinsic excitability of DG granule neurons was enhanced by adiponectin deficiency and suppressed after treatment with the adiponectin mimetic AdipoRon, which were associated with increased input resistance and hyperpolarized resting membrane potential, respectively. Moreover, deletion of AdipoR2, but not AdipoR1 in the DG, resulted in augmented fear expression and reduced extinction, accompanied by intrinsic hyperexcitability of DG granule neurons. Adiponectin and AdipoRon failed to induce facilitation of fear extinction and elicit inhibition of intrinsic excitability of DG neurons in AdipoR2 knockout mice. These results indicated that adiponectin action via AdipoR2 was both necessary and sufficient for extinction of contextual fear and intrinsic excitability of DG granule neurons, implying that enhancing or dampening DG neuronal excitability may cause resistance to or facilitation of extinction. Therefore, our findings provide a functional link between adiponectin/AdipoR2 activation, DG neuronal excitability and contextual fear extinction, and suggest that targeting adiponectin/AdipoR2 may be used to strengthen extinction-based exposure therapies for PTSD.

Antioxidative therapy in an ex vivo human cartilage trauma-model: attenuation of trauma-induced cell loss and ECM-destructive enzymes by N-acetyl cysteine.

OBJECTIVE: Mechanical trauma of articular cartilage results in cell loss and cytokine-driven inflammatory response. Subsequent accumulation of reactive oxygen (ROS) and nitrogen (RNS) species enhances the enzymatic degradation of the extracellular matrix (ECM). This study aims on the therapeutic potential of N-acetyl cysteine (NAC) in a human ex vivo cartilage trauma-model, focusing on cell- and chondroprotective features. DESIGN: Human full-thickness cartilage explants were subjected to a defined impact trauma (0.59 J) and treated with NAC. Efficiency of NAC administration was evaluated by following outcome parameters: cell viability, apoptosis rate, anabolic/catabolic gene expression, secretion and activity of matrix metalloproteinases (MMPs) and proteoglycan (PG) release. RESULTS: Continuous NAC administration increased cell viability and reduced the apoptosis rate after trauma. It also suppressed trauma-induced gene expression of ECM-destructive enzymes, such as ADAMTS-4, MMP-1, -2, -3 and -13 in a dosage- and time-depending manner. Subsequent suppression of MMP-2 and MMP-13 secretion reflected these findings on protein level. Moreover, NAC inhibited proteolytic activity of MMPs and reduced PG release. CONCLUSION: In the context of this ex vivo study, we showed not only remarkable cell- and chondroprotective features, but also revealed new encouraging findings concerning the therapeutically effective concentration and treatment-time regimen of NAC. Its defense against chondrocyte apoptosis and catabolic enzyme secretion recommends NAC as a multifunctional add-on reagent for pharmaceutical intervention after cartilage injury. Taken together, our data increase the knowledge on the therapeutic potential of NAC after cartilage trauma and presents a basis for future in vivo studies.

Impact of Breast Density Legislation on Breast Cancer Risk Assessment and Supplemental Screening: A Survey of 110 Radiology Facilities.

Breast density notification laws, passed in 19 states as of October 2014, mandate that patients be informed of their breast density. The purpose of this study is to assess the impact of this legislation on radiology practices, including performance of breast cancer risk assessment and supplemental screening studies. A 20-question anonymous web-based survey was emailed to radiologists in the Society of Breast Imaging between August 2013 and March 2014. Statistical analysis was performed using Fisher's exact test. Around 121 radiologists from 110 facilities in 34 USA states and 1 Canadian site responded. About 50% (55/110) of facilities had breast density legislation, 36% of facilities (39/109) performed breast cancer risk assessment (one facility did not respond). Risk assessment was performed as a new task in response to density legislation in 40% (6/15) of facilities in states with notification laws. However, there was no significant difference in performing risk assessment between facilities in states with a law and those without (p < 0.831). In anticipation of breast density legislation, 33% (16/48), 6% (3/48), and 6% (3/48) of facilities in states with laws implemented handheld whole breast ultrasound (WBUS), automated WBUS, and tomosynthesis, respectively. The ratio of facilities offering handheld WBUS was significantly higher in states with a law than in states without (p < 0.001). In response to breast density legislation, more than 33% of facilities are offering supplemental screening with WBUS and tomosynthesis, and many are performing formal risk assessment for determining patient management.

Supplemental Breast Cancer Screening With Molecular Breast Imaging for Women With Dense Breast Tissue.

OBJECTIVE: Molecular breast imaging was implemented in routine clinical practice at a large community-based breast imaging center. The aim of this study was to retrospectively assess the clinical performance of molecular breast imaging as a supplementary screening tool for women with dense breast tissue. MATERIALS AND METHODS: Women with dense breasts and negative mammography results who subsequently underwent screening with 300 MBq (8 mCi) (99m)Tc-sestamibi molecular breast imaging were retrospectively analyzed. Outcome measures included cancer detection rate, recall rate, biopsy rate, and positive predictive values (PPVs). RESULTS: Molecular breast imaging screening of 1696 women in this study resulted in the detection of 13 mammographically occult malignancies, of which 11 were invasive, one was node positive, and one had unknown node positivity. The lesion size ranged from 0.6 to 2.4 cm, with a mean of 1.1 cm. The incremental cancer detection rate was 7.7‰ (95% CI, 4.5-13.1‰), the recall rate was 8.4% (95% CI, 7.2-9.8%), and the biopsy rate was 3.7% (95% CI, 2.9%-4.7%). The PPV for recall (PPV 1) was 9.1% (95% CI, 5.4-15.0%), and the PPV for biopsy (PPV 3) was 19.4% (95% CI, 11.4-30.9%). CONCLUSION: When incorporated into a community-based clinical practice environment, molecular breast imaging yielded a high incremental cancer detection rate of 7.7‰ at an acceptable radiation dose. These results show the utility of molecular breast imaging as a supplementary screening tool to mammography for women with dense breasts.

Characterization of a migrative subpopulation of adult human nasoseptal chondrocytes with progenitor cell features and their potential for in vivo cartilage regeneration strategies.

BACKGROUND: Progenitor cells display interesting features for tissue repair and reconstruction. In the last years, such cells have been identified in different cartilage types. In this study, we isolated a migrative subpopulation of adult human nasoseptal chondrocytes with progenitor cell features by outgrowth from human nasal septum cartilage. These putative progenitor cells were comparatively characterized with mesenchymal stem cells (MSC) and human nasal septum chondrocytes with respect to their cellular characteristics as well as surface marker profile using flow cytometric analyses. Differentiation capacity was evaluated on protein and gene expression levels. RESULTS: The migrative subpopulation differentiated into osteogenic and chondrogenic lineages with distinct differences to chondrocytes and MSC. Cells of the migrative subpopulation showed an intermediate surface marker profile positioned between MSC and chondrocytes. Significant differences were found for CD9, CD29, CD44, CD90, CD105 and CD106. The cells possessed a high migratory ability in a Boyden chamber assay and responded to chemotactic stimulation. To evaluate their potential use in tissue engineering applications, a decellularized septal cartilage matrix was either seeded with cells from the migrative subpopulation or chondrocytes. Matrix production was demonstrated immunohistochemically and verified on gene expression level. Along with secretion of matrix metalloproteinases, cells of the migrative subpopulation migrated faster into the collagen matrix than chondrocytes, while synthesis of cartilage specific matrix was comparable. CONCLUSIONS: Cells of the migrative subpopulation, due to their migratory characteristics, are a potential cell source for in vivo regeneration of nasal cartilage. The in vivo mobilization of nasal cartilage progenitor cells is envisioned to be the basis for in situ tissue engineering procedures, aiming at the use of unseeded biomaterials which are able to recruit local progenitor cells for cartilage regeneration.

The parasite Ichthyophonus sp. in Pacific herring from the coastal NE Pacific.

The protistan parasite Ichthyophonus occurred in populations of Pacific herring Clupea pallasii Valenciennes throughout coastal areas of the NE Pacific, ranging from Puget Sound, WA north to the Gulf of Alaska, AK. Infection prevalence in local Pacific herring stocks varied seasonally and annually, and a general pattern of increasing prevalence with host size and/or age persisted throughout the NE Pacific. An exception to this zoographic pattern occurred among a group of juvenile, age 1+ year Pacific herring from Cordova Harbor, AK in June 2010, which demonstrated an unusually high infection prevalence of 35%. Reasons for this anomaly were hypothesized to involve anthropogenic influences that resulted in locally elevated infection pressures. Interannual declines in infection prevalence from some populations (e.g. Lower Cook Inlet, AK; from 20-32% in 2007 to 0-3% during 2009-13) or from the largest size cohorts of other populations (e.g. Sitka Sound, AK; from 62.5% in 2007 to 19.6% in 2013) were likely a reflection of selective mortality among the infected cohorts. All available information for Ichthyophonus in the NE Pacific, including broad geographic range, low host specificity and presence in archived Pacific herring tissue samples dating to the 1980s, indicate a long-standing host-pathogen relationship.

Systemic mesenchymal stem cell administration enhances bone formation in fracture repair but not load-induced bone formation.

Mesenchymal stem cells (MSC) were shown to support bone regeneration, when they were locally transplanted into poorly healing fractures. The benefit of systemic MSC transplantation is currently less evident. There is consensus that systemically applied MSC are recruited to the site of injury, but it is debated whether they actually support bone formation. Furthermore, the question arises as to whether circulating MSC are recruited only in case of injury or whether they also participate in mechanically induced bone formation. To answer these questions we injected green fluorescent protein (GFP)-labelled MSC into C57BL/6J mice, which were subjected either to a femur osteotomy or to non-invasive mechanical ulna loading to induce bone formation. We detected GFP-labelled MSC in the early (day 10) and late fracture callus (day 21) by immunohistochemistry. Stromal cell-derived factor 1 (SDF-1 or CXCL-12), a key chemokine for stem cell attraction, was strongly expressed by virtually all cells near the osteotomy--indicating that SDF-1 may mediate cell migration to the site of injury. We found no differences in SDF-1 expression between the groups. Micro-computed tomography (µCT) revealed significantly more bone in the callus of the MSC treated mice compared to untreated controls. The bending stiffness of callus was not significantly altered after MSC-application. In contrast, we failed to detect GFP-labelled MSC in the ulna after non-invasive mechanical loading. Histomorphometry and µCT revealed a significant load-induced increase in bone formation; however, no further increase was found after MSC administration. Concluding, our results suggest that systemically administered MSC are recruited and support bone formation only in case of injury but not in mechanically induced bone formation.

The California breast density information group: a collaborative response to the issues of breast density, breast cancer risk, and breast density notification legislation.

In anticipation of breast density notification legislation in the state of California, which would require notification of women with heterogeneously and extremely dense breast tissue, a working group of breast imagers and breast cancer risk specialists was formed to provide a common response framework. The California Breast Density Information Group identified key elements and implications of the law, researching scientific evidence needed to develop a robust response. In particular, issues of risk associated with dense breast tissue, masking of cancers by dense tissue on mammograms, and the efficacy, benefits, and harms of supplementary screening tests were studied and consensus reached. National guidelines and peer-reviewed published literature were used to recommend that women with dense breast tissue at screening mammography follow supplemental screening guidelines based on breast cancer risk assessment. The goal of developing educational materials for referring clinicians and patients was reached with the construction of an easily accessible Web site that contains information about breast density, breast cancer risk assessment, and supplementary imaging. This multi-institutional, multidisciplinary approach may be useful for organizations to frame responses as similar legislation is passed across the United States. Online supplemental material is available for this article.

Evaluation of breast silicone implants.

While clinical evaluation of breast implants and their complications can identify capsule contracture and rupture of saline implants, the identification of silicone implant failure is best accomplished by silicone specific protocols for MRI with orthogonal acquisition. Such imaging can also help resolve other clinical problems. Following a brief overview of the history and development of commercial use of silicone implants and alternatives, this article outlines the approach toward optimal imaging and expected results.

[The staged approach--an overview on a strategy to reduce spinal cord injury in thoracoabdominal aortic aneurysm repair]. / Das zweizeitige Vorgehen zur Reduktion der spinalen Ischämie bei der Ausschaltung thorakoabdomineller Aortenaneurysmen - eine Übersicht.

The spinal cord is particularly susceptible to ischaemic injury following repair of extensive descending thoracic and thoracoabdominal aortic aneurysms (TAAA). For the past decade, the Mount Sinai group in New York has intensively studied the anatomy of the extensive vascular network surrounding the spinal cord, as well as its dynamic morphology in response to decreased blood pressure and flow. Along with clinical data, experimental findings gave rise to the Collateral Network Concept, by which spinal cord injury in open TAAA repair can be significantly reduced. With the more recent widespread use of endovascular repair, strategies to prevent ischaemic spinal cord damage after extensive segmental artery sacrifice/occlusion are still evolving. The hypothesis that dividing extensive aneurysm repair into two steps may mitigate the impact of diminished blood flow to the collateral network has led to a recently conducted series of staged repair experiments. By exploiting the resources of the collateral network, spinal cord injury could be minimised in staged open, as well as in staged hybrid repair and seems equally adoptable for endovascular procedures. The contribution presented herein provides an overview of clinical and experimental studies on the staged approach. Furthermore, it briefly assesses the anatomic rationale for the collateral network concept.

Benefit of semiannual ipsilateral mammographic surveillance following breast conservation therapy.

PURPOSE: To compare cancer recurrence outcomes on the basis of compliant semiannual versus noncompliant annual ipsilateral mammographic surveillance following breast conservation therapy (BCT). MATERIALS AND METHODS: A HIPAA-compliant retrospective review was performed of post-BCT examinations from 1997 through 2008 by using a deidentified database. The Committee on Human Research did not require institutional review board approval for this study, which was considered quality assurance. Groups were classified according to compliance with institutional post-BCT protocol, which recommends semiannual mammographic examinations of the ipsilateral breast for 5 years. A compliant semiannual examination was defined as an examination with an interval of 0-9 months, although no examination had intervals less than 3 months. A noncompliant annual examination was defined as an examination with an interval of 9-18 months. Cancer recurrence outcomes were compared on the basis of the last examination interval leading to diagnosis. RESULTS: Initially, a total of 10 750 post-BCT examinations among 2329 asymptomatic patients were identified. Excluding initial mammographic follow-up, there were 8234 examinations. Of these, 7169 examinations were semiannual with 94 recurrences detected and 1065 examinations were annual with 15 recurrences detected. There were no differences in demographic risk factors or biopsy rates. Recurrences identified at semiannual intervals were significantly less advanced than those identified at annual intervals (stage I vs stage II, P = .04; stage 0 + stage I vs stage II, P = .03). Nonsignificant findings associated with semiannual versus annual intervals included smaller tumor size (mean, 11.7 vs 15.3 mm; P = .15) and node negativity (98% vs 91%, P = .28). CONCLUSION: Results suggest that a semiannual interval is preferable for ipsilateral mammographic surveillance, allowing detection of a significantly higher proportion of cancer recurrences at an earlier stage than noncompliant annual surveillance.