Acceleration and transport of relativistic electrons in the jets of the microquasar SS 433

SS 433 is a microquasar, a stellar binary system that launches collimated relativistic jets. We observed SS 433 in gamma rays using the High Energy Stereoscopic System (H.E.S.S.) and found an energy-dependent shift in the apparent position of the gamma-ray emission from the parsec-scale jets. These observations trace the energetic electron population and indicate that inverse Compton scattering is the emission mechanism of the gamma rays. Our modeling of the energy-dependent gamma-ray morphology constrains the location of particle acceleration and requires an abrupt deceleration of the jet flow. We infer the presence of shocks on either side of the binary system, at distances of 25 to 30 parsecs, and that self-collimation of the precessing jets forms the shocks, which then efficiently accelerate electrons.

Search for Dark Matter Annihilation Signals in the H.E.S.S. Inner Galaxy Survey

The central region of the Milky Way is one of the foremost locations to look for dark matter (DM) signatures. We report the first results on a search for DM particle annihilation signals using new observations from an unprecedented γ-ray survey of the Galactic Center (GC) region, i.e., the Inner Galaxy Survey, at very high energies (≳100  GeV) performed with the H.E.S.S. array of five ground-based Cherenkov telescopes. No significant γ-ray excess is found in the search region of the 2014-2020 dataset and a profile likelihood ratio analysis is carried out to set exclusion limits on the annihilation cross section ⟨σv⟩. Assuming Einasto and Navarro-Frenk-White (NFW) DM density profiles at the GC, these constraints are the strongest obtained so far in the TeV DM mass range. For the Einasto profile, the constraints reach ⟨σv⟩ values of 3.7×10^{-26}  cm^{3} s^{-1} for 1.5 TeV DM mass in the W^{+}W^{-} annihilation channel, and 1.2×10^{-26}  cm^{3} s^{-1} for 0.7 TeV DM mass in the τ^{+}τ^{-} annihilation channel. With the H.E.S.S. Inner Galaxy Survey, ground-based γ-ray observations thus probe ⟨σv⟩ values expected from thermal-relic annihilating TeV DM particles.

Time-resolved hadronic particle acceleration in the recurrent nova RS Ophiuchi

Recurrent novae are repeating thermonuclear explosions in the outer layers of white dwarfs, due to the accretion of fresh material from a binary companion. The shock generated when ejected material slams into the companion star's wind can accelerate particles. We report very-high-energy (VHE, [Formula: see text]) gamma rays from the recurrent nova RS Ophiuchi, up to a month after its 2021 outburst, observed using the High Energy Stereoscopic System. The VHE emission has a similar temporal profile to lower-energy GeV emission, indicating a common origin, with a two-day delay in peak flux. These observations constrain models of time-dependent particle energization, favoring a hadronic emission scenario over the leptonic alternative. Shocks in dense winds provide favorable environments for efficient acceleration of cosmic-rays to very high energies.

Revealing x-ray and gamma ray temporal and spectral similarities in the GRB 190829A afterglow

Gamma-ray bursts (GRBs), which are bright flashes of gamma rays from extragalactic sources followed by fading afterglow emission, are associated with stellar core collapse events. We report the detection of very-high-energy (VHE) gamma rays from the afterglow of GRB 190829A, between 4 and 56 hours after the trigger, using the High Energy Stereoscopic System (H.E.S.S.). The low luminosity and redshift of GRB 190829A reduce both internal and external absorption, allowing determination of its intrinsic energy spectrum. Between energies of 0.18 and 3.3 tera-electron volts, this spectrum is described by a power law with photon index of 2.07 ± 0.09, similar to the x-ray spectrum. The x-ray and VHE gamma-ray light curves also show similar decay profiles. These similar characteristics in the x-ray and gamma-ray bands challenge GRB afterglow emission scenarios.

AB0412 URINARY SOLUBLE VCAM-1 IS A USEFUL BIOMARKER OF DISEASE ACTIVITY AND TREATMENT RESPONSE IN LUPUS NEPHRITIS

Background:

The traditional lupus nephritis (LN) biomarkers are not sensitive nor specific enough for detecting ongoing disease activity and early relapse of nephritis and they do not reflect kidney damage nor have prognostic value1. Urinary biomarkers are directly excreted by the kidney and are easily obtained. They can also differentiate the renal activity of the disease from other organic manifestations more accurately than the serum biomarkers2. Vascular cell adhesion molecule-1 (VCAM-1) is involved in the progression of glomerular and tubulointerstitial injury in LN and its soluble form can be easily assessed in urine (uVCAM-1)3. Several studies correlated the uVCAM-1 levels with urine protein-creatinine ratio (UPC), with general disease activity and with active LN3.

Objectives:

To assess uVCAM-1 as a biomarker of disease activity and treatment response in LN.

Methods:

This prospective study enrolled patients with class III, IV or V LN diagnosed within the last three years and divided them in two groups: with and without active nephritis at the inclusion. The patients with active nephritis were included before they started a new immunosuppressive treatment. Active LN was defined as proteinuria (UPC≥0.5) plus active urinary sediment (hematuria, leukocyturia or cellular hematic/granular casts). At each visit, a urine sample was collected for uVCAM-1 evaluation and the nephritis status was accessed.

Results:

Median uVCAM-1 level was elevated in patients with active compared to inactive LN (p<0.001). The ROC curve of uVCAM-1 demonstrated an AUC of 0.84 and a cutoff of 47.2 ng/mgCr yielded a good sensitivity (74.2%) and specificity (74.2%) for the diagnosis of active LN. A significant correlation was found between uVCAM-1 level and renal activity scores and traditional biomarkers of LN (table 1). The level of uVCAM-1 dropped in patients with active LN who went into remission (p<0.001), increased in patients who went into activity (p=0.002) and did not change in patients who remained inactive (p=0.797) (figure 1). The level of uVCAM-1 peaked during the flare of LN (p<0.05) (figure 2).

Table 1.

Correlations between urinary soluble VCAM-1 and other LN biomarkers/disease scores

LN biomarkers/disease scoresVCAM-1SLEDAI-2k0.597***Renal SLEDAI0.569***Renal SLAM-R0.470***Renal SLICC0.620***Anti-dsDNA0.342**C3-0.344**C4-0.382**UPC0.654***

Spearman’s correlation coefficients

*pvalue <0.05; **pvalue <0.01; ***pvalue <0.001

C, complement; LN, lupus nephritis; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index; renal SLAM-R, The renal Systemic Lupus Activity Measure revised; renal SLICC, The Systemic Lupus International Collaborating Clinics renal activity/response exercise; UPC, urine protein-creatinine ratio.

Conclusion:

The uVCAM-1 is a reliable biomarker that reflects renal disease activity and is useful for monitoring individual patients with lupus nephritis over time.

References:

[1]Mok CC. Biomarkers for lupus nephritis: A critical appraisal. J Biomed Biotechnol. 2010;2010:638413.

[2]Reyes-Thomas J, Blanco I, Putterman C. Urinary Biomarkers in Lupus Nephritis. Clin Rev Allergy Immunol. 2010;40:138–50.

[3]Gasparin AA, Pamplona Bueno de Andrade N, Hax V, Tres GL, Veronese FV, Monticielo OA. Urinary biomarkers for lupus nephritis: the role of the vascular cell adhesion molecule-1. Lupus. 2019;28:265-272.

Acknowledgments:

We acknowledge the Research Incentive Fund (FIPE/HCPA) and the Research Support Fund of Brazilian Society of Rheumatology that supported this work.

Disclosure of Interests:

Andrese Aline Gasparin: None declared, Nicole Pamplona Bueno de Andrade: None declared, Vanessa Hax: None declared, Penelope Palominos Grant/research support from: This work was sponsored by the regional society of rheumatology (Sociedade de Reumatologia do Rio Grande do Sul)., Marina Siebert: None declared, Romulo Marx: None declared, Pedro Shaefer: None declared, Francisco Veríssimo Veronese: None declared, Odirlei Monticielo: None declared

Granulations denses anormales dans les thrombocytes humains

On sait que les granulations denses des thrombocytes humains peuvent présenter, dans certains cas, des aspects inhabituels: granulations denses en bâtonnet, granulations denses géantes et granulations denses en “oeil-de-boeuf”. L’étude systématique au microscope électronique de thrombocytes de sujets sains et de 30 patients atteints de thrombopathies diverses a permis d’analyser la fréquence de l’apparition de cette altération, mais n’a pas montré que la présence de granulations denses anormales caractérise un type de thrombopathie déterminé. Par contre, l’analyse des réactions de ces organites tant normaux qu’anormaux vis-à- vis de certains “contrastants électroniques”, ainsi que l’étude ultrastructurelle de la thrombocytopoïèse chez l’animal de laboratoire, ont permis d’émettre quelques hypothèses sur leur genèse et leur signification. Enfin, les auteurs discutent des rapports qui peuvent exister entre déficience du facteur thrombocytaire 3 et altérations des granulations denses.

Sur la présence de graisses neutres dans les thrombocytes humains normaux et pathologiques

La microscopie électronique a montré, dans les thrombocytes humains, la présence de gouttelettes lipidiques. Dans les plaquettes normales, le pourcentage de coupes présentant cette caractéristique ultrastructurelle est très faible; cette observation concorde avec les résultats des analyses biochimiques et cytochimiques. Par contre, dans les thrombopathies (surtout congénitales), leur proportion est significativement augmentée. Nous pouvons donc considérer que la mise en évidence d’une stéatose thrombocytaire notable est un des critères valables du diagnostic d’un état pathologique des thrombocytes.

L’aspect submicroscopique des gouttelettes lipidiques intrathrombocytaires permet de penser qu’elles sont constituées vraisemblablement de graisses neutres très riches en acides gras non saturés. Cette hypothèse est appuyée par des études cytochimiques récentes au microscope électronique des constituants lipidiques.

Nos observations montrent que la genèse des gouttelettes lipidiques n’est vraisemblablement pas liée à une lipophanérose, ni à une phagocytose de chylomicrons. Par contre, la diminution du taux de glycogène dans les plaquettes présentant une stéatose, nous permet de supposer que les gouttelettes lipidiques peuvent être considérées comme l’indice d’un trouble du métabolisme plaquettaire.

Search for γ-Ray Line Signals from Dark Matter Annihilations in the Inner Galactic Halo from 10 Years of Observations with H.E.S.S

Spectral lines are among the most powerful signatures for dark matter (DM) annihilation searches in very-high-energy γ rays. The central region of the Milky Way halo is one of the most promising targets given its large amount of DM and proximity to Earth. We report on a search for a monoenergetic spectral line from self-annihilations of DM particles in the energy range from 300 GeV to 70 TeV using a two-dimensional maximum likelihood method taking advantage of both the spectral and spatial features of the signal versus background. The analysis makes use of Galactic center observations accumulated over ten years (2004-2014) with the H.E.S.S. array of ground-based Cherenkov telescopes. No significant γ-ray excess above the background is found. We derive upper limits on the annihilation cross section ⟨σv⟩ for monoenergetic DM lines at the level of 4×10^{-28}  cm^{3} s^{-1} at 1 TeV, assuming an Einasto DM profile for the Milky Way halo. For a DM mass of 1 TeV, they improve over the previous ones by a factor of 6. The present constraints are the strongest obtained so far for DM particles in the mass range 300 GeV-70 TeV. Ground-based γ-ray observations have reached sufficient sensitivity to explore relevant velocity-averaged cross sections for DM annihilation into two γ-ray photons at the level expected from the thermal relic density for TeV DM particles.

Co-Localization of Macrophage Inhibitory Factor and Nix in Skeletal Muscle of the Aged Male Interleukin 10 Null Mouse

Chronic inflammation is associated with muscle weakness and frailty in older adults. The antagonistic cross-talk between macrophage migration inhibitory factor (Mif), an anti-apoptotic cytokine and NIP3-like protein X (Nix), a pro-apoptotic mitochondrial protein, may play a role in mitochondrial free radical homeostasis and inflammatory myopathies. We examined Nix-Mif interaction in inflammation and aging using young and old, IL-10tm/tm (a rodent model of chronic inflammation) and C57BL/6 mice. In this study, we observed that Nix and Mif were co-localized in skeletal muscles of aged and inflamed mice. We show an inflammation- and age-related association between Nix and Mif gene expression, with the strongest positive correlation observed in old IL-10tm/tm skeletal muscles. The IL-10tm/tm skeletal muscles also had the highest levels of oxidative stress damage. These observations suggest that Nix-Mif cross-talk may play a role in the interface between chronic inflammation and oxidative stress in aging skeletal muscles.

Ultra-broadband EPR spectroscopy in field and frequency domains

Electron paramagnetic resonance (EPR) is a powerful technique to investigate the electronic and magnetic properties of a wide range of materials.

Effect of Surface Roughness on Flexural Strength of Veneer Ceramics

The strength of ceramic restorations depends on the occlusal surface roughness of the veneering porcelain, which is influenced by the final preparation. The hypothesis of the study was that roughnesses below a critical microscopic defect size—based only on fracture mechanics considerations—also affect flexural strength. The bending failure stress was evaluated on standard specimens of 4 veneer ceramics with 4 different surfaces of defined roughnesses, respectively. A linear correlation was found between roughness and failure stress. A "roughness-free" failure stress value was predicted for each tested material. This theoretical value can represent the "true" strength of the respective ceramic material. We conclude from our results that the final preparation of a ceramic restoration is critical to the strength of the material, and that ceramic veneering materials can be compared more objectively with respect to their strength by means of roughness-free strength values.

H.E.S.S. Limits on Linelike Dark Matter Signatures in the 100 GeV to 2 TeV Energy Range Close to the Galactic Center

A search for dark matter linelike signals iss performed in the vicinity of the Galactic Center by the H.E.S.S. experiment on observational data taken in 2014. An unbinned likelihood analysis iss developed to improve the sensitivity to linelike signals. The upgraded analysis along with newer data extend the energy coverage of the previous measurement down to 100 GeV. The 18 h of data collected with the H.E.S.S. array allow one to rule out at 95% C.L. the presence of a 130 GeV line (at l=-1.5°, b=0° and for a dark matter profile centered at this location) previously reported in Fermi-LAT data. This new analysis overlaps significantly in energy with previous Fermi-LAT and H.E.S.S.

RESULTS

No significant excess associated with dark matter annihilations was found in the energy range of 100 GeV to 2 TeV and upper limits on the gamma-ray flux and the velocity weighted annihilation cross section are derived adopting an Einasto dark matter halo profile. Expected limits for present and future large statistics H.E.S.S. observations are also given.

Search for Dark Matter Annihilations towards the Inner Galactic Halo from 10 Years of Observations with H.E.S.S

The inner region of the Milky Way halo harbors a large amount of dark matter (DM). Given its proximity, it is one of the most promising targets to look for DM. We report on a search for the annihilations of DM particles using γ-ray observations towards the inner 300 pc of the Milky Way, with the H.E.S.S. array of ground-based Cherenkov telescopes. The analysis is based on a 2D maximum likelihood method using Galactic Center (GC) data accumulated by H.E.S.S. over the last 10 years (2004-2014), and does not show any significant γ-ray signal above background. Assuming Einasto and Navarro-Frenk-White DM density profiles at the GC, we derive upper limits on the annihilation cross section ⟨σv⟩. These constraints are the strongest obtained so far in the TeV DM mass range and improve upon previous limits by a factor 5. For the Einasto profile, the constraints reach ⟨σv⟩ values of 6×10^{-26}  cm^{3} s^{-1} in the W^{+}W^{-} channel for a DM particle mass of 1.5 TeV, and 2×10^{-26}  cm^{3} s^{-1} in the τ^{+}τ^{-} channel for a 1 TeV mass. For the first time, ground-based γ-ray observations have reached sufficient sensitivity to probe ⟨σv⟩ values expected from the thermal relic density for TeV DM particles.

[Rehabilitation standards for follow-up treatment and rehabilitation of patients with ventricular assist device (VAD)]

The increasing use of ventricular assist devices (VADs) in terminal heart failure patients provides new challenges to cardiac rehabilitation physicians. Structured cardiac rehabilitation strategies are still poorly implemented for this special patient group. Clear guidance and more evidence for optimal modalities are needed. Thereby, attention has to be paid to specific aspects, such as psychological and social support and education (e.g., device management, INR self-management, drive-line care, and medication).In Germany, the post-implant treatment and rehabilitation of VAD Patients working group was founded in 2012. This working group has developed clear recommendations for the rehabilitation of VAD patients according to the available literature. All facets of VAD patients' rehabilitation are covered. The present paper is unique in Europe and represents a milestone to overcome the heterogeneity of VAD patient rehabilitation.

[Progress of Rehabilitation for Cardiac Patients Depending on the Degree of Self-Sufficiency at Admission]

INTRODUCTION

There are hardly any publications about the outcome of cardiac rehabilitation considering patients with an increased need for medical, nursing and therapeutic care. The aim of this study, which consecutively included n=387 statutory health insurance inpatients over a period of 2 years, was to find out differences in outcome in self-care patients (Barthel index>70) as compared to patients with a need for complex care (Barthel index≤70).

METHODS

Rehabilitation outcomes concerning physical capacity, emotional status and activities of daily living as measured by Barthel index, FIM index, HADS, clinical complications, exercise test, duration of rehabilitation and form of dismission were analyzed and compared between both groups.

RESULTS

The inpatients with a Barthel index ≤70 at admission were older, had a longer stay in hospital and in rehabilitation, developed more complications and more often suffered from concomitant diseases. They were readmitted to hospital more often. They showed a comparatively higher increase in indices of self-care and a significant increase in physical performance tests.

CONCLUSION

Higher medical care expenses of multimorbid cardiac inpatients are no contraindication against rehabilitation, because even in this group the specific rehabilitation aims of the healthcare payers can be reached.

[Bone cement adhesion on ceramic surfaces - surface activation of retention surfaces of knee prostheses by atmospheric plasma versus thermal surface treatment]

AIM

CoCrMo alloys are contraindicated for allergy sufferers. For these patients, uncemented and cemented prostheses made of titanium alloy are indicated. Knee prostheses machined from that alloy, however, may have poor tribological behaviour, especially in relation to UHMWPE inlays. Therefore, for knee replacement cemented high-strength oxide ceramic prostheses are suitable for allergy sufferers and in cases of particle-induced aseptic loosening. For adhesion of bone cement, the ceramic surface, however, only exposes inefficient mechanical retention spots as compared with a textured metal surface. Undercuts generated by corundum blasting which in the short-term are highly efficient on a CoCrMo surface are not possible on a ceramic surface due to the brittleness of ceramics. Textures due to blasting may initiate cracks which will weaken the strength of a ceramic prosthesis. Due to the lack of textures mechanical retention is poor or even not existent. Micromotions are promoted and early aseptic loosening is predictable. Instead silicoating of the ceramic surface will allow specific adhesion and result in better hydrolytic stability of bonding thereby preventing early aseptic loosening. Silicoating, however, presupposes a clean and chemically active surface which can be achieved by atmospheric plasma or thermal surface treatment.

METHOD

In order to evaluate the effectiveness of silicoating the bond strengths of atmospheric plasma versus thermal surface treated and silicate layered ZPTA surfaces were compared with "as-fired" surfaces by utilising TiAlV probes (diameter 6 mm) for traction-adhesive strength tests. After preparing samples for traction-adhesive strength tests (sequence: ceramic substrate, silicate and silane, protective lacquer [PolyMA], bone cement, TiAlV probe) they were aged for up to 150 days at 37 °C in Ringer's solution.

RESULTS

The bond strengths observed for all ageing intervals were well above 20 MPa and much higher and more hydrolytically stable for silicate layered compared with "as-fired" ZPTA samples.

CONCLUSION

Silicoating may be effective for achieving high initial bond strength of bone cement on surfaces of oxide ceramics and also suitable to stabilise bond strength under hydrolytic conditions as present in the human body in the long-term. Activation by atmospheric plasma or thermal surface treatment seems to be effective for activation prior to silicoating. Due the proposed silicate layer migration, micromotions and debonding should be widely reduced or even eliminated.

Constraints on an annihilation signal from a core of constant dark matter density around the milky way center with H.E.S.S

An annihilation signal of dark matter is searched for from the central region of the Milky Way. Data acquired in dedicated on-off observations of the Galactic center region with H.E.S.S. are analyzed for this purpose. No significant signal is found in a total of ∼9  h of on-off observations. Upper limits on the velocity averaged cross section, ⟨σv⟩, for the annihilation of dark matter particles with masses in the range of ∼300  GeV to ∼10  TeV are derived. In contrast to previous constraints derived from observations of the Galactic center region, the constraints that are derived here apply also under the assumption of a central core of constant dark matter density around the center of the Galaxy. Values of ⟨σv⟩ that are larger than 3×10^{-24}  cm^{3}/s are excluded for dark matter particles with masses between ∼1 and ∼4  TeV at 95% C.L. if the radius of the central dark matter density core does not exceed 500 pc. This is the strongest constraint that is derived on ⟨σv⟩ for annihilating TeV mass dark matter without the assumption of a centrally cusped dark matter density distribution in the search region.

Revision ACL reconstruction outcomes: MOON cohort

Many clinicians believe that the results of revision anterior cruciate ligament (ACL) reconstruction compare unfavorably with primary ACL reconstruction. However, few prospective studies have evaluated revision ACL reconstruction using validated patient-based metrics. This study was performed to evaluate and compare the results of revision ACL reconstruction and primary ACL reconstruction. The Multicenter Orthopaedic Outcomes Network consortium is an NIH-funded, hypothesis-driven, multicenter prospective cohort study of patients undergoing ACL reconstruction. All patients preoperatively complete a series of validated patient-oriented questionnaires. At scheduled 2-year follow-up all patients are given the same series of questionnaires to complete. The study evaluated the results of 2-year follow-up of revision ACL reconstruction performed in 2001. Parameters evaluated included Marx activity level, Knee Injury and Osteoarthritis Outcome Score (KOOS), and International Knee Documentation Committee (IKDC) scores. For this study 446 subjects met inclusion criteria; 2-year follow-up was obtained on 393 (88%). The study group consisted of 55% males with median age of 22 years. There were 33 revision ACL reconstruction cases, for which follow-up was available for 29 (88%). Median baseline Marx (interquartile range) was 12 (8 to 16) and 12 (6 to 16) for the primary ACL reconstruction and revision ACL reconstruction groups, respectively (p= 0.81). At 2 years, median Marx was 9 (4 to 13) and 5 (0 to 10) for the primary ACL reconstruction and revision ACL reconstruction groups, respectively (p= 0.03). Median 2-year IKDC was 75.9 (revision) versus 83.9 (primary) (p=0.003). Median KOOS subscale Knee Related Quality of Life (KRQOL) at 2 years was 62.5 (revision) versus 75 (primary) (p < 0.001), subscale Sports and Recreation was 75 (revision) and 85 (primary) (p = 0.005), subscale Pain was 83.3 (revision) and 91.7 (primary) (p= 0.002). Marx activity score declined at 2-year follow-up in revision ACL reconstruction compared with primary ACL reconstruction. IKDC and KRQOL were significantly decreased in revision ACL reconstruction compared with primary ACL reconstruction at 2-year followup. Revision ACL reconstruction resulted in a significantly worse outcome as measured by these patient-based measures at 2 years.

[PVD-silicoating before cementation of zirconia-based knee prostheses effects better cement adhesion and lower aseptic loosening rates]

AIM

CoCrMo alloys are contraindicated for allergy patients. For these patients, cemented or uncemented prostheses made of titanium alloy are indicated. Uncemented prostheses, however, have low primary retention, particularly the tibial components of knee joint prostheses because of the lack of a positive locking. Therefore, for knee replacement cemented CoCrMo prostheses may be suitable also for allergy sufferers if these are masked by ZrN or TiNbN layers. Alternatively the CoCrMo alloy may be replaced by high-strength oxide ceramics. For adhesion of bone cement to the ceramic surface, however, only inefficient mechanical retention spots are exposed as compared with a metal surface. Undercuts generated by corundum blasting, although highly efficient on a CoCrMo surface, are not such efficient centres on a ceramic surface due to its brittleness. Therefore, the mechanical component of retention is significantly reduced. When specific adhesion between bone cement and surface does not exist due to physical and chemical forces, the hydrolytic stability will be insufficient. Micromotions are promoted and early aseptic loosening is predictable. Silicoating of the ceramic surface will allow specific adhesion and can result in better hydrolytic stability of bonding.

METHODS

In order to evaluate the effectiveness of silicoating the bond strengths of blasted (mean size of corundum grains 50 µm) and silicate layered alumina-toughened zirconia (ATZ) surfaces were compared with "as fired" surfaces by utilising TiAlV probes (diameter 6 mm) for traction-adhesive strength testing. Samples machined out of CoCrMo alloy were utilised for reference. After preparing the samples for traction-adhesive strength testing (sequence: substrate, silicate and silane, protective lacquer [PolyMA], bone cement, TiAlV probe) they were aged up to 360 days at 37 °C in Ringer's solution.

RESULTS

The bond strengths observed for all ageing intervals were well above 20 MPa and much higher and more hydrolytically stable for blasted and silicate-layered compared with "as fired" ATZ samples.

CONCLUSION

Silicoating may be effective for achieving a high initial bond strength of bone cement on surfaces of oxide ceramics and also suitable to stabilise bond strength under hydrolytic conditions as present in the human body. Activation by low grain size corundum (mean grain size 50 µm) seems to be effective for activation without deteriorating the bending strength of the ceramics investigated. Due to the proposed layer system migration, micromotions and debonding should be widely reduced or even eliminated.

Loss of sarcolemmal nNOS is common in acquired and inherited neuromuscular disorders

OBJECTIVE

Neuronal nitric oxide synthase (nNOS), normally expressed at the sarcolemmal membrane, is known to be mislocalized to the sarcoplasm in several forms of muscular dystrophy. Our objectives were to characterize further the range of patients manifesting aberrant nNOS sarcolemmal immunolocalization and to study nNOS localization in animal models of nondystrophic myopathy.

METHODS

We carried out a retrospective cross-sectional study. We performed immunofluorescent staining for nNOS on biopsy specimens from 161 patients with acquired and nondystrophin inherited neuromuscular conditions. The localization of sarcolemmal nNOS correlated with mobility and functional status. Muscle specimens from mouse models of steroid-induced and starvation-related atrophy were studied for qualitative and quantitative nNOS expression.

RESULTS

Sarcolemmal nNOS staining was abnormal in 42% of patients with inherited myopathic conditions, 25% with acquired myopathic conditions, 57% with neurogenic conditions, and 93% with hypotonia. Interestingly, we found significant associations between mobility status or muscle function and sarcolemmal nNOS expression. Furthermore, mouse models of catabolic stress also demonstrated mislocalization of sarcolemmal nNOS.

CONCLUSION

Our analyses indicate that nNOS mislocalization is observed in a broad range of nondystrophic neuromuscular conditions associated with impaired mobility status and catabolic stress. Our findings suggest that the assessment of sarcolemmal localization of nNOS represents an important tool for the evaluation of muscle biopsies of patients with a variety of inherited and acquired forms of neuromuscular disorders.

Local cytokine profiles in knee osteoarthritis: elevated synovial fluid interleukin-15 differentiates early from end-stage disease

OBJECTIVE

Much of what is known about the inflammatory response in the synovial membrane (SM) of patients with osteoarthritis (OA) comes from studies of synovial tissues from end-stage disease. In this study, we sought to better characterize the inflammatory infiltrate in symptomatic patients with early signs of knee OA, and to determine how inflammatory cell populations relate to the pattern of cytokine and degradative enzyme production.

METHODS

Study populations comprised patients with degenerative meniscal tears and early cartilage thinning undergoing arthroscopic procedures (early OA) and patients undergoing total knee replacement for end-stage OA. Quantitative real-time polymerase chain reaction (PCR) was used to measure expression of SM cytokines and enzymes implicated in the pathogenesis of inflammatory arthritis and OA, as well as cell lineage-specific markers. We quantified synovial fluid (SF) cytokines and enzymes by enzyme-linked immunosorbent assay (ELISA) and SM cell populations by immunohistochemistry.

RESULTS

We found increased levels of SF interleukin-15 (IL-15) protein in the early knee OA patients when compared to end-stage OA. Both SF IL-15 protein and numbers of CD8 cells within SM correlated with matrix metalloproteinase-1 (MMP-1) and three levels. TNF-alpha, IL-6 and IL-21 were also detectable in the SF of the majority of patients, and IL-15 levels were associated with IL-6 levels.

CONCLUSION

IL-15 is elevated in early knee OA, suggesting activation of an innate immune response in the SM. The association of IL-15 expression with CD8 transcripts and MMPs implicates this cytokine in OA pathogenesis and as a candidate therapeutic target.

Effect of bavistin on in vitro plant conversion from encapsulated uninodal microcuttings of micropropagated Bacopa monnieri (L.)--an Ayurvedic herb

A reliable and reproducible protocol for contamination free plant recovery system from alginated encapsulated uninodal microcuttings of micropropagated Bacopa monnieri L. have been developed after storage at 18 degrees C for 45 days. Node segments excised from freshly micropropagated plants were encapsulated as single explant beads with 3.0% sodium alginate and 80 mM CaCl2 2 H2O. To find out the optimal concentration of fungicide bavistin for efficient plant recovery different concentrations of bavistin (1.0 - 15 mg l(-1)) were incorporated in to the encapsulation medium. 3.0mg l(-1) bavistin showed no reduction in plant conversion and generated maximum number of shoots (45.6 +/- 1.69) at high frequency with out any contamination after storage up to 45 days at 18 degrees C. At high concentrations (13 and 15 mg l(-1)), rupturing of calcium alginate coats after 8 - 9 days and gradual decline in the number of shoots indicates the toxic effect of bavistin on plant conversion. Encapsulated node cuttings stored up to 45 days regenerated shoots (5.2) and multiple shoots (45.6) in MS basal and hormone medium respectively. Maximum shoot length (8.2 +/- 0.37 cm) was observed from encapsulsted node cuttings incorporated with 3.0 mg l(-1) bavistin on MS basal medium. 90% of the recovered plantlets were hardened off and successfully established in soil.

[Silicate coating of cemented titanium-based shafts in hip prosthetics reduces high aseptic loosening]

AIM

For cemented hip prostheses, all requirements can be fulfilled by using forged Co/Cr/Mo stems. Co/Cr/Mo alloys, however, are contraindicated for allergy sufferers. For these patients, a cemented prosthesis made of titanium (alloy) would be indicated. Cemented stems from titanium (alloy), depending on the geometry of the prosthesis and its specific surface texture, however, may have loosening rates which are clinically not tolerable. In comparison to Co/Cr/Mo alloys, the greater roughness in conjunction with lesser abrasion resistance of titanium-based alloys leads to high loosening rates caused by abrasion. On the other hand, the greater surface roughness permits good mechanical retention of bone cement to the surface. Good mechanical retention enhances migration behaviour and reduces micromotions. However, there is no stable hydrolytic bond between bone cement and metallic surface; intermediate-term debonding between metal and bone cement is predictable. This debonding results in relative movements, consequently in wear particles which have their origin both from the rough metallic surface and from the PMMA cement. The roughness of the metallic surface operates as emery and with that, a rubbing wear from the PMMA.

METHOD

For the above reasons, a low or moderate roughness is essential for easily abradable implants such as shafts made of titanium (alloy) because low roughness provides a fail-safe running function in case of debonding. Thus, one must allow for inappropriate migration behaviour accompanied by greater micromotions due to insufficient mechanical retention in the case of low roughness. This can be accomplished by a silicate layer coating applied to the metal shaft surface via electrochemical "ECD" or physical vapour deposition "PVD". For analysis, specimens (screws for pull-out, cones for push-out tests) were sand-blasted, so that roughnesses between Ra = 0.8 microm (Rz = 4 microm) and Ra = 2.0 microm (Rz = 9 microm) were generated.

RESULTS

The bond strengths observed in tensile tests for roughnesses of Ra = 1.7 mm were always well above 25 MPa for all periods of hydrolytic load. Therefore, the investigation shows that surfaces of moderate roughness (Ra = 1.7 microm), however coated, provide a steady retention. Cave-in and micromotions should widely be prevented.

CONCLUSION

The abrasion, which is a consequence of and reason for debonding and loosening at the same time, should be avoidable if the bonding of cement on the metallic shaft is stabilised with the help of a suitable chemical bond system.

Surface coating to improve the metal-cement bonding in cemented femur stems

INTRODUCTION

Hydrolytic debonding of the metal-cement interface is one of the main reasons for aseptic loosening in cemented hip arthroplasty.

MATERIALS AND METHODS

BiContact femur stems (CoCrMo-/TiAl6V4-alloy) were coated by a silica/silane interlayer coating system. The stems were cemented into artificial femurs. The cyclical loading (DIN ISO 7206-4) was performed within a hip-simulator. Uncoated stems (CoCrMo-/TiAl6V4-alloy) were prepared and loaded the same way. After loading, the metal-cement and the bone-cement interfaces were analysed. Unloaded uncoated and unloaded coated BiContact stems served as a control.

RESULTS

The coated loaded stems showed a significant reduction in debonding and cement failure (P < or = 0.05). A high correlation was documented between debonding and cement failure (rSpear> or = 0.9). There was no significant difference between CoCrMo- and TiAl6V4-stems (P > or = 0.05).

CONCLUSION

The silica/silane coating significantly decreased hydrolytic debonding at the metal-bone cement interface with consecutively less cement failure.

[Surface pretreatment of endoprostheses by silica/silane to optimise the hydrolytic stability between bone cement and metal. Total hip and knee arthroplasty]

BACKGROUND

The aseptic loosening of cemented total hip and knee arthroplasties is still an unsolved problem. In this regard, the hydrolytic resistance in the metal-to-bone cement interface is of major importance.

METHODS

Cemented pretreated femur stems and tibia components coated by means of a silica/silane interlayer system were dynamically loaded with the help of a hip and knee simulator similar to DIN ISO Norm. After loading, the components were microscopically analysed concerning both debonding in the metal-to-bone cement interface and cement mantle defects. These data were matched with uncoated components. Unloaded coated and uncoated femur and tibia components acted as controls.

RESULTS

Compared with uncoated components, the pretreated and coated ones yielded a significant reduction in cement defects as well as of debonding in the metal-to-bone cement interface.

CONCLUSION

Using the silica/silane interlayer system for cemented femur and tibia components, hydrolytic debonding in the metal-to-bone cement interface with following cement mantle failure can be reduced. This could help increase the long-term stability of the metal-to-bone cement compound, with decreased aseptic loosening.

[Mechanical bending strength of explanted ex vivo bone cements compared with in vitro samples]

INTRODUCTION

The mechanical properties of acrylic bone cements are an important factor in determining an efficient load transmission between prosthesis and bone to guarantee the long-term stability in cemented hip arthroplasty.

MATERIAL AND METHODS

Palacos and Refobacin Palacos specimens from 21 aseptically loosened femoral compoments of cemented hip arthroplasties manufactured by the first to third generation cementing technique have been mechanically tested in a standardised four-point bending test (ISO 5833). In vitro manufactured Palacos and Refobacin Palacos specimens served as a control group. The fatigue fracture surfaces were morphologically analysed with light microscopy.

RESULTS

Under in vitro conditions manufactured specimens had higher values of bending strength, with the exception of blood contaminated ones, compared to ex vivo specimens. Ex vivo specimens of the second and third generation cementing technique had higher values than specimens of the first generation.

CONCLUSIONS

Acrylic bone cements are subjected to a multifactorial material fatigue in vivo. Here, the art and quality of cementing technique is of eminent importance in determining the long-term stability of cemented hip arthroplasty.

[Application of an amphiphilic bonder in a goat model to increase the femoral cement-bone adhesion in cemented hip arthroplasty]

AIM

Cemented revision of femoral components in total hip arthroplasty has shown high rates of early loosening due to reduced micro- and macroretention of the cement to the endostal bone stock. Enhanced stability can be reached by an amphiphilic bonder, which offers a covalent bonding of the hydrophobic cement to the hydrophilic bone. The aim of this study is to evaluate the biocompatibility of such a bonder and its effects on the mechanical stability of cemented hip arthroplasty stems in vivo.

METHODS

Total cemented hip arthroplasties were performed in 20 sheep. In the verum group (n = 10) the implant bed was preconditioned by application of the bonder prior to femoral stem implantation. To study the biocompatibility around the bone-cement interface fluorescent marking of osteoblasts was applied in vivo throughout the observation period of 9 months. Native X-rays of the hip joints were obtained immediately after implantation and after euthanasia. The bone-cement interface was examined histologically.

RESULTS

All stems of the verum group showed firm bonding of cement to bone in manual testing, while in 7 of the 10 controls the stems with adherent cement could be easily pulled out off the bony implant bed. This was coherent with significantly higher rates of progredient radiolucent lines and soft-tissue interpositions between bone and cement in the control group. The bonder was biocompatible.

CONCLUSION

When preconditioned with an amphiphilic bonder, cemented stems showed a markedly higher adhesive strength to the cancellous bone without signs of inflammation or neoplasia. This procedure might offer enhanced longevity of cemented femoral revision stems in hip arthroplasty.

Improvement of the long-term adhesive strength between bone cement and bone in cemented cup arthroplasty: ex-vivo study

INTRODUCTION

One of the main causes of cup loosening in cemented total hip replacement is the lack of a hydrolysis stable compound between the hydrophobic bone cement and the hydrophilic acetabular bone stock. Thus, the long-term adhesive strength between bone and bone cement is decreased resulting in premature aseptic loosening. Accordingly, an amphiphilic bonding system was developed to prevent hydrolytic debonding in the interface bone-to-bone cement.

MATERIALS AND METHODS

Polyethylene cups were cemented in cadaver sheep hips. The hips were prepared with (n = 10) a multilayer bonding system as well as with an improved monolayer bonding system with (n = 10) and without (n = 10) UV-light hardening. The hips were dynamically loaded (10(6) cycles; 3 Hz; upper/lower load 1,500/200 N) and afterwards turned out with a defined strength to determine the interface compound strength. Dynamically loaded cemented cups without using the bonding system (n = 10) function as a control group.

RESULTS

The interface adhesive strength improved significantly by a factor of 1.9 (using the multilayer bonding system) compared to the unconditioned ones (P < or = 0.05); for the monolayer bonding system without (with) UV-light hardening the compound strength was 11.9-fold (> or =22.2-fold) higher (P < or = 0.001).

CONCLUSION

The bonding system significantly improves the adhesive strength between bone and bone cement in cemented cup arthroplasty.

Aortic insufficiency due to a partial left-coronary aortic valve prolapse and the detection of two small interatrial jets after blunt thoracic trauma

Aortic valve regurgitation due to blunt thoracic trauma is a rare complication. Autopsy studies have been shown that the aortic valve is the most often lacerated one among the heart valves. Actually, we describe a case of a 47 year old man with the signs of heart failure after a blunt thoracic trauma 2 months before caused by aortic insufficiency due to a partial left-coronary aortic valve prolapse. Furthermore, transthoracic and transesophageal echocardiography revealed two small jets between the left and the right atrium.

Bisphosphonate use and osteonecrosis of the jaw: Pharmacovigilance and reporting of this serious adverse event from the Research on Adverse Drug Events and Reports (RADAR) project

6519

Background: Two years after zoledronate, received FDA approval, four dental professionals treated 107 cases of osteonecrosis of the jaw (ONJ). We review the timeline and source for initial recognition of ONJ and the comprehensiveness of dissemination of information on this adverse drug event. Methods: Data sources included primary case series from dental professionals; published case reports, clinical trials, and cases reported to the manufacturers or the FDA. Exposure adjusted incidence rates estimates were derived from manufacturer sponsored and investigator initiated review of claims data from large cancer centers. Safety notifications were disseminated by the manufacturers, regulatory authorities, and academic investigators. Results: Between 2001 and 2003, 107 patients with ONJ received care from dental professionals. In late 2003, and 2004 peer-reviewed case series were published. By 2006, safety databases maintained by the FDA, the manufacturer, and the RADAR project included information on 2,270, 1,178, and 368 cases of ONJ, respectively. In 2004 and 2005, incidence estimates of 0.8 and 22 ONJ cases per 1,000 person-years of intravenous bisphosphonate therapy were reported by the manufacturer and academic investigators. From 2003 to 2006, safety information from manufacturers, national regulatory authorities, case series, and clinical guidelines were disseminated. Conclusions: Recognition and reporting of ONJ occurred two years after FDA approval of zoledronate, dissemination of safety information occurred in the third year, and publications were disseminated from year three to year five. The life-cycle for identification and information dissemination for this serious adverse drug reaction was short and comprehensive.

[Table: see text] [Table: see text]

HIV prevention case management in San Francisco: barriers to successful implementation

Prevention case management (PCM) is the most labor-intensive HIV prevention intervention for persons at risk for acquiring or transmitting HIV. However, it has not been thoroughly evaluated. We abstracted client charts (n = 290) from 12 San Francisco PCM programs and interviewed current and former program directors (n=16), case managers (n = 17) and contract managers (n = 4) regarding client characteristics, services delivered, barriers to care, cost and organizational structure, policies and procedures. Most agencies lacked protocols and data collection forms, had high staff turnover, inadequate staff training and supervision, experienced difficulty recruiting and retaining clients and could not implement PCM guidelines. Half the clients lacked behavioral risk assessment, 39% were low or no risk, a third received HIV prevention education and a third received referrals. Including time spent directly with clients and working on their behalf, PCM cost almost four-fold more per client contact than the next most costly individual level prevention intervention. Local PCM guidelines, reimbursement ties to providing and documenting services and increased collaboration between the health department and agencies has greatly improved the situation. Outcome evaluations and cost-effectiveness assessments comparing PCM to less costly prevention interventions are needed.

[Cemented total knee arthroplasties]

INTRODUCTION

The aseptic loosening of cemented total knee arthroplasties is still an unsolved problem. In this regard, the hydrolysis resistance in the metal-to-bone cement interface is of major importance.

MATERIAL AND METHODS

Cemented pre-treated tibia components coated by means of a silica/silane interlayer system of the model "Columbus PS" were dynamically loaded with the help of a knee-simulator similar to DIN ISO 14243. After loading, the components were microscopically analysed concerning debonding in the metal-to-bone cement interface as well as with regard to cement mantle defects. These data were matched with uncoated "Columbus PS" components. Unloaded coated and uncoated tibia components acted as a control.

RESULTS

In comparison with uncoated tibia components, the pre-treated and coated ones yielded a highly significant reduction of cement defects (p < 0.01) as well as a significant reduction of debonding in the metal-to-bone cement interface (p < 0.05).

CONCLUSION

By means of the silica/silane interlayer system for cemented tibia components, a hydrolytic debonding in the metal-to-bone cement interface with subsequent mechanical loosening and consecutive early cement mantle failure can be significantly reduced. This could lead to an increased long-term stability of the metal-to-bone cement compound with decreased aseptic loosening in clinical use.