[Current design and cement mantle thickness in hip arthroplasty : Theory and analysis of register data]

BACKGROUND

In this article, an overview and comparison of the most commonly used cemented hip stems, grouped into different stem types and cement mantle thickness, is given to see which combination performs well.

METHODOLOGY

Revision rates of cemented stem types were categorized from the Endoprosthesis Register-Germany, and 3‑ and 5‑year revision rates were reported and analyzed. For the research, the focus was on the Exeter, C‑Stem, MS-30, Excia, Bicontact, Charnley, Müller straight stem, Twinsys, Corail, Avenir, Quadra, and the Lubinus SP II stems. An important aspect was which stem is preferred to be implanted and which cementing technique is used with regard to the planned cement mantle thickness. In order to identify a trend in cemented hip arthroplasty, data from the Danish, Swedish, Norwegian, Swiss, New Zealand, English and Australian arthroplasty registers were also compared.

RESULTS AND CONCLUSION

Most countries use cemented prostheses according to the taper slip principle (Exeter, MS30, C‑Stem etc) or the composite beam (Charnley, Excia, Bicontact), which are implanted with a cement mantle thickness of 2-4 mm. However, a trend has emerged in Germany and Switzerland towards the line-to-line technique, with a planned cement mantle thickness of 1 mm (Twinsys, Corail, Avenir, Quadra), following the principle of the Müller straight stem prosthesis and the Kerboul-Charnley prosthesis, even though these are postulated to be "French paradoxes" in themselves. In the EPRD 5‑year results, the newer line-to-line prostheses seem to perform slightly worse. The best results are achieved by the "MS 30" in Germany and the "Exeter" in England. These are polished straight stems with centralizer and subsidence space at the apex with a 2-4 mm cement mantle in good cementing technique.

Sprague Dawley rats from different vendors vary in the modulation of prepulse inhibition of startle (PPI) by dopamine, acetylcholine, and glutamate drugs

RATIONALE

Rodent vendors are often utilized interchangeably, assuming that the phenotype of a given strain remains standardized between colonies. Several studies, however, have found significant behavioral and physiological differences between Sprague Dawley (SD) rats from separate vendors. Prepulse inhibition of startle (PPI), a form of sensorimotor gating in which a low-intensity leading stimulus reduces the startle response to a subsequent stimulus, may also vary by vendor. Differences in PPI between rat strains are well known, but divergence between colonies within the SD strain lacks thorough examination.

OBJECTIVES

We explored intrastrain variation in PPI by testing SD rats from two vendors: Envigo and Charles River (CR).

METHODS

We selected drugs acting on four major neurotransmitter systems that have been repeatedly shown to modulate PPI: dopamine (apomorphine; 0.5, 1.5, 3.0 mg/kg), acetylcholine (scopolamine; 0.1, 0.5, 1.0 mg/kg), glutamate (dizocilpine; 0.5, 1.5, 2.5 mg/kg), and serotonin (2,5-Dimethoxy-4-iodoamphetamine, DOI; 0.25, 0.5, 1.0 mg/kg). We determined PPI and startle amplitude for each drug in male and female Envigo and CR SD rats.

RESULTS

SD rats from Envigo showed dose-dependent decreases in PPI after apomorphine, scopolamine, or dizocilpine administration, without significant effects on startle amplitude. SD rats from CR were less sensitive to modulation of PPI and/or more sensitive to modulation of startle amplitude, across the three drugs.

CONCLUSIONS

SD rats showed vendor differences in sensitivity to pharmacological modulation of PPI and startle. We encourage researchers to sample rats from separate vendors before experimentation to identify the most suited source of subjects for their specific endpoints.

Beta-blocker/ACE inhibitor therapy differentially impacts the steady state signaling landscape of failing and non-failing hearts

Background

The molecular underpinnings of heart failure with reduced ejection fraction (HFrEF) involves a complex remodeling of the contractile, metabolic and electrical functions. Current pharmacotherapy for patients presenting HFrEF includes combination of angiotensin-converting enzyme inhibitors (ACEi) and β-adrenergic receptor blockers (β-AR blockers). Yet, a knowledge gap exists regarding the molecular changes accompanying such treatment.

Purpose

The present study takes an omics approach to study protein and phosphorylation signaling derangement in HFrEF and to define the global changes resulting from treatment with β-AR blocker (metoprolol) and ACE inhibitor (enalapril) in control- and HFrEF hearts.

Methods and results

For induction of HFrEF, a tight and permanent ligature was applied to constrict the transverse aorta in male C57BL6 mice. Eight weeks post-surgery, an osmotic pump was implanted delivering either vehicle or treatment (enalapril, ACE inhibitor, and metoprolol, β-AR blocker) for a two week period. The proteome- and phosphoproteome of left ventricular tissue was resolved using high-resolution liquid chromatography-mass spectrometry. The resulting dataset covered 6,004 proteins and 14,967 phosphorylation events. HFrEF was characterized by profound downregulation of mitochondrial proteins coupled with derangement of β-adrenergic and pyruvate dehydrogenase signaling. Upon treatment, phosphorylation changes consequent to HFrEF were reversed, including a reversal of Pdhk4 activity. In controls, treatment mainly led to downregulation of canonical PKA signaling. Overall, the signaling response elicited by treatment was profoundly different for failing than for control hearts.

Conclusions

We used state-of-the-art proteomics and phosphoproteomics approaches to analyze changes in protein abundance and phosphorylation state of the left ventricle resulting from combination therapy with a β-AR blocker and an ACE inhibitor in failing and non-failing hearts. Our observation of divergent signaling outcomes depending on the disease state of the heart underscores the importance of evaluating drug effects within the context of the specific conditions present in the recipient heart.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): The Danish Council for independent ResearchLundbeck FoundationFondation Leducq Transatlantic Network of Excellence

Health policy versus kava (Piper methysticum): Anxiolytic efficacy may be instrumental in restoring the reputation of a major South Pacific crop

ETHNOPHARMACOLOGICAL RELEVANCE

Kava (Piper methysticum G. Forst. f.) is by far the most important plant used in the islands of Melanesia, Polynesia and Micronesia for its relaxing effects. Kava drinking is a pillar of South Pacific societies and is also the foundation of their economies. Preparations of kava extract as herbal medicinal drugs were banned in Germany in 2002 and again in 2019, with dramatic consequences for the South Pacific economies. In 2002, the major regulatory argument for the ban of kava was safety issues. In 2019, the assessment report of the European Medicines Agency's Herbal Medicinal Product Committee (HMPC) justified a negative benefit-to-risk ratio by a supposed lack of efficacy of ethanolic extracts for an indication of which kava extract preparations never had an approval. In this HMPC report the efficacy in the approved indications 'nervous anxiety, tension and restlessness' was attributed to the extract branded as 'WS 1490', which was assumed to have been prepared with acetone as an extraction solvent. In addition to this change of indication and the attribution of efficacy to acetone kava extract alone, the German health authorities and the HMPC still refuse to discuss quality issues as a likely factor impacting drug safety. The first case reports of liver toxicity were observed with an acetone extract in a timely relationship with the introduction of 'two-day kava' instead of 'noble kava' as used in ethanolic kava extracts.

AIM OF THE STUDY

The correlation between clinical benefits and the type of extract preparation was examined.

METHODS

In order to identify the types of kava material and extracts used in clinical trials, the respective publications were compared with regulatory databases and protocols of a German regulatory advisory board.

RESULTS AND CONCLUSIONS

The comparison reveals inconsistencies in the regulatory decisions. In all studies with WS 1490, the evidence points to the use of an ethanolic extract. The efficacy of kava extract for the approved indication was clearly demonstrated. The HMPC report and the recent renewed German regulatory ban of kava therefore require major revision, which should include the impact of the use of "two-day kava" on drug safety. Such a revision could contribute to restoring the reputation of "noble kava" on the international markets.

Aging-related carcinoembryonic antigen-related cell adhesion molecule 1 signaling promotes vascular dysfunction

Aging is an independent risk factor for cardiovascular diseases and therefore of particular interest for the prevention of cardiovascular events. However, the mechanisms underlying vascular aging are not well understood. Since carcinoembryonic antigen‐related cell adhesion molecule 1 (CEACAM1) is crucially involved in vascular homeostasis, we sought to identify the role of CEACAM1 in vascular aging. Using human internal thoracic artery and murine aorta, we show that CEACAM1 is upregulated in the course of vascular aging. Further analyses demonstrated that TNF‐α is CEACAM1‐dependently upregulated in the aging vasculature. Vice versa, TNF‐α induces CEACAM1 expression. This results in a feed‐forward loop in the aging vasculature that maintains a chronic pro‐inflammatory milieu. Furthermore, we demonstrate that age‐associated vascular alterations, that is, increased oxidative stress and vascular fibrosis, due to increased medial collagen deposition crucially depend on the presence of CEACAM1. Additionally, age‐dependent upregulation of vascular CEACAM1 expression contributes to endothelial barrier impairment, putatively via increased VEGF/VEGFR‐2 signaling. Consequently, aging‐related upregulation of vascular CEACAM1 expression results in endothelial dysfunction that may promote atherosclerotic plaque formation in the presence of additional risk factors. Our data suggest that CEACAM1 might represent an attractive target in order to delay physiological aging and therefore the transition to vascular disorders such as atherosclerosis.

Interaction with St. John's wort due to exposure with blackcurrant aroma? How not to present a case report of an adverse event

Background: Adverse events case reports are important for signal generation in pharmacovigilance. They require a thorough collation of the facts, otherwise they may lead to erroneous conclusions which may conceal other treatment-related causes of the observation. Methods: We describe a case report from the literature that arrives at an erroneous conclusion merely from taking insufficient care when collating and interpreting the facts: The authors of the case report confused blackcurrant (Ribes nigrum) with St. John's wort preparation (Hypericum perforatum) and erroneously assumed that the intake of a herbal preparation was responsible for a drop in serum levels of everolimus. Results: The clinical observations in this case report may actually reflect a potentially lethal situation emerging from the prescribed medication everolimus. St. John's wort preparations rich in hyperforin do in fact reproducibly lead to the decrease of blood levels of medications metabolized through cytochrome P450 subtype 3A4. However, a case report requires more care than just ascribing the blame to something seemingly well-known. Conclusion: The readers of this report might have profited more from the description of the risks of treating graft-versus-host disease with everolimus, and the action to be taken in case of potentially severe adverse reactions to everolimus.

Zinc deficits, mucositis, and mucosal macrophage perturbation: is there a relationship?

PURPOSE OF REVIEW

Mucositis is a common and therapy-limiting adverse effect of cancer treatments including radiotherapy, chemotherapy, and immunotherapy. The optimal zinc formulation, dosage, and timing of administration warrant further research as does the efficacious prevention of febrile mucositis that predisposes to febrile neutropenia.

RECENT FINDINGS

Metaanalyses concluded that zinc sulfate failed to significantly reduce the incidence or severity of chemotherapy-induced oral mucositis, whereas polaprezinc was associated with a significant reduction. Three new trials were published in 2018. The first trial found that zinc sulfate reduced the incidence and severity of chemotherapy-induced oral mucositis. The second reported that polaprezinc reduced oral mucositis in pediatric patients receiving high-dose chemotherapy for hematopoietic stem cell transplantation. The third trial demonstrated efficacy for a zinc lozenge for postoperative sore throat induced by an endotracheal intubation.

SUMMARY

Zinc deficits, dietary or induced by cancer, are common in patients with cancer. Febrile mucositis may better describe the condition linking mucositis with febrile neutropenia. Febrile mucositis disrupts treatment and may be life-threatening. A paradigm shift is needed for a more comprehensive understanding of febrile mucositis. Zinc effects on the thymic immunological network and T lymphocytes during chemoradiotherapy regimens also warrant further investigation.

Interaction of gut microbiota with dysregulation of bile acids in the pathogenesis of nonalcoholic fatty liver disease and potential therapeutic implications of probiotics

The intestinal microbiota is now recognised to play key roles in health due to its involvement in many aspects of human physiology. Disturbance in gut microbiota (dysbiosis) is thus associated with many diseases including nonalcoholic fatty liver disease (NAFLD) which includes nonalcoholic fatty liver and nonalcoholic steatohepatitis. The mechanisms for the effect of dysbiosis in NAFLD pathogenesis are not completely elucidated. Many explanations have been proposed to trigger dysbiosis, leading to NAFLD including inflammation, ethanol produced by the gut bacteria and lipotoxicity. Recently the roles of bile acids and nuclear receptors are highly regarded. It is well known that gut microbes produce enzymes that convert primary bile acids into secondary bile acids in the intestines. Several studies have demonstrated that disturbance of the intestinal microbiota leads to decreased synthesis of secondary bile acids, which in turn decreases activation of nuclear receptors such as farnesoid X receptor (FXR), pregnane X receptor, Takeda G-protein-coupled bile acid protein 5 and vitamin D receptor. These receptors are important in energy regulation and their dysregulation can cause NAFLD. Therefore, stimulation of nuclear receptors especially FXR has been extensively explored for the amelioration of NAFLD. However, paradoxical effects of nuclear receptor activation are a major problem for the clinical application of nuclear receptor stimuli. We further posit that microbiome restoration could be an alternative approach for the treatment of NAFLD. Several gut bacteria are now known to be involved in bile acid metabolism. It will be necessary to identify which one/ones is/are feasible. Careful selection of commensal bacteria for probiotics may lead to an effective therapy for NAFLD.

The role of adjuvant probiotics to attenuate intestinal inflammatory responses due to cancer treatments

Chemotherapy and radiotherapy treatment regimens for gastrointestinal, peritoneal and pelvic tumours can disrupt the intestinal microbiome and intestinal epithelia. Such disturbances can provoke symptoms such as diarrhoea, nausea and vomiting. Chemotherapy and radiotherapy induced gastrointestinal toxicity aggravating intestinal microbiome dysbiosis is postulated to adversely alter the intestinal microbiome, with a consequent induced pro-inflammatory effect that disrupts the intestinal microbiome-epithelia-mucosal immunity axis. Although not widely recognised, the intestinal mucosa is the largest and most densely and dynamically populated immune-environment. Cancer treatment adverse effects that affect intestinal and mucosal cells inadvertently target and disrupt resident intestinal macrophages, the cells that marshal immune activity in the intestinal mucosa by shaping pro-inflammatory and anti-inflammatory activities to control and eradicate infectious insults and maintain local homeostasis. Pathobionts (bacteria capable of pathogenic pro-inflammatory activity) and noxious environmental and bacterial antigens use the intestinal epithelia and gap junctions as a point of entry into the systemic circulation. This translocation movement promotes toxic sequelae that obstruct intestinal macrophage functions resulting in uncontrolled local and systemic pro-inflammatory activity, loss of phagocytic function and loss of expression of tight junction proteins. Probiotic bacteria as an adjunctive treatment shows efficacy in ameliorating enteropathies such as mucositis/diarrhoea resulting from chemotherapy or radiotherapy regimens. As such we posit that an important benefit that warrants a further focused research effort is the administration of adjuvant probiotics to help reduce the incidence of febrile neutropenia.

Diagnostic guidelines for the histological particle algorithm in the periprosthetic neo-synovial tissue

BACKGROUND

The identification of implant wear particles and non-implant related particles and the characterization of the inflammatory responses in the periprosthetic neo-synovial membrane, bone, and the synovial-like interface membrane (SLIM) play an important role for the evaluation of clinical outcome, correlation with radiological and implant retrieval studies, and understanding of the biological pathways contributing to implant failures in joint arthroplasty. The purpose of this study is to present a comprehensive histological particle algorithm (HPA) as a practical guide to particle identification at routine light microscopy examination.

METHODS

The cases used for particle analysis were selected retrospectively from the archives of two institutions and were representative of the implant wear and non-implant related particle spectrum. All particle categories were described according to their size, shape, colour and properties observed at light microscopy, under polarized light, and after histochemical stains when necessary. A unified range of particle size, defined as a measure of length only, is proposed for the wear particles with five classes for polyethylene (PE) particles and four classes for conventional and corrosion metallic particles and ceramic particles.

RESULTS

All implant wear and non-implant related particles were described and illustrated in detail by category. A particle scoring system for the periprosthetic tissue/SLIM is proposed as follows: 1) Wear particle identification at light microscopy with a two-step analysis at low (× 25, × 40, and × 100) and high magnification (× 200 and × 400); 2) Identification of the predominant wear particle type with size determination; 3) The presence of non-implant related endogenous and/or foreign particles. A guide for a comprehensive pathology report is also provided with sections for macroscopic and microscopic description, and diagnosis.

CONCLUSIONS

The HPA should be considered a standard for the histological analysis of periprosthetic neo-synovial membrane, bone, and SLIM. It provides a basic, standardized tool for the identification of implant wear and non-implant related particles at routine light microscopy examination and aims at reducing intra-observer and inter-observer variability to provide a common platform for multicentric implant retrieval/radiological/histological studies and valuable data for the risk assessment of implant performance for regional and national implant registries and government agencies.

Adjunctive Treatments for the Prevention of Chemotherapy- and Radiotherapy-Induced Mucositis

Background: Chemoradiotherapy-associated mucositis can manifest as pain, inflammation, dysphagia, diarrhea, weight loss, rectal bleeding, and infection. Mucositis is a major dose-limiting side effect of chemotherapy, affecting nutritional intake and oral and intestinal function. Despite several interventions being available, there is a need for safe and effective preventative and treatment options for treatment-induced mucositis. The goals of this review are to discuss interventions based on foods and natural products and present the research to date. Methods: A narrative literature review identified 60 clinical studies examining various nutritional compounds and 20 examining probiotics. 9 studies on probiotics for the prevention of diarrhea were also assessed on methodological quality and limitations identified. Results: Several compounds have been posited as useful adjuvants for cancer treatment–related mucositis. Probiotics demonstrate efficacy for the prevention and treatment of chemoradiotherapy-induced gastrointestinal toxicity without significant side effects. Glutamine and activated charcoal were reported to reduce chemotherapy-induced diarrhea but not radiation-induced intestinal mucositis. Honey has been reported to decrease treatment interruptions, weight loss, and delays the onset of oral mucositis. Zinc, glutamine, and topical vitamin E were demonstrated efficacy for oral mucositis. Conclusion: There is plausible clinical evidence for the administration of several adjunctive treatments for the prevention and treatment of mucositis. Probiotics were reported to reduce the burden of intestinal mucositis and treatment-induced diarrhea. Activated charcoal and glutamine are beneficial for chemotherapy-induced diarrhea, whereas the administration of honey, zinc, and glutamine reduce the risk of developing oral mucositis during chemotherapy or radiotherapy.

Correction: Vitetta, L.; et al. Adjuvant Probiotics and the Intestinal Microbiome: Enhancing Vaccines and Immunotherapy Outcomes. Vaccines 2017, 5, 50

The authors wish to make the following corrections to this paper due to a typesetting error in the conclusion of this article which was recently published in Vaccines.

Intestinal Microbiome Shifts, Dysbiosis, Inflammation, and Non-alcoholic Fatty Liver Disease

Adverse fluctuations in the distribution of the intestinal microbiome cohort has been associated with the onset of intra- and extra-intestinal inflammatory conditions, like the metabolic syndrome (MetS) and it's hepatic manifestation, non-alcoholic fatty liver disease (NAFLD). The intestinal microbial community of obese compared to lean subjects has been shown to undergo configurational shifts in various genera, including but not limited to increased abundances of Prevotella, Escherichia, Peptoniphilus, and Parabacteroides and decreased levels of Bifidobacteria, Roseburia, and Eubacteria genera. At the phylum level, decreased Bacteroidetes and increased Firmicutes have been reported. The intestinal microbiota therefore presents an important target for designing novel therapeutic modalities that target extra-intestinal inflammatory disorders, such as NAFLD. This review hypothesizes that disruption of the intestinal-mucosal macrophage interface is a key factor in intestinal-liver axis disturbances. Intestinal immune responses implicated in the manifestation, maintenance and progression of NAFLD provide insights into the dialogue between the intestinal microbiome, the epithelia and mucosal immunity. The pro-inflammatory activity and immune imbalances implicated in NAFLD pathophysiology are reported to stem from dysbiosis of the intestinal epithelia which can serve as a source of hepatoxic effects. We posit that the hepatotoxic consequences of intestinal dysbiosis are compounded through intestinal microbiota-mediated inflammation of the local mucosa that encourages mucosal immune dysfunction, thus contributing important plausible insight in NAFLD pathogenesis. The administration of probiotics and prebiotics as a cure-all remedy for all chronic diseases is not advocated, instead, the incorporation of evidence based probiotic/prebiotic formulations as adjunctive modalities may enhance lifestyle modification management strategies for the amelioration of NAFLD.

Adjuvant Probiotics and the Intestinal Microbiome: Enhancing Vaccines and Immunotherapy Outcomes

Immune defence against pathogenic agents comprises the basic premise for the administration of vaccines. Vaccinations have hence prevented millions of infectious illnesses, hospitalizations and mortality. Acquired immunity comprises antibody and cell mediated responses and is characterized by its specificity and memory. Along a similar congruent yet diverse mode of disease prevention, the human host has negotiated from in utero and at birth with the intestinal commensal bacterial cohort to maintain local homeostasis in order to achieve immunological tolerance in the new born. The advent of the Human Microbiome Project has redefined an appreciation of the interactions between the host and bacteria in the intestines from one of a collection of toxic waste to one of a symbiotic existence. Probiotics comprise bacterial genera thought to provide a health benefit to the host. The intestinal microbiota has profound effects on local and extra-intestinal end organ physiology. As such, we further posit that the adjuvant administration of dedicated probiotic formulations can encourage the intestinal commensal cohort to beneficially participate in the intestinal microbiome-intestinal epithelia-innate-cell mediated immunity axes and cell mediated cellular immunity with vaccines aimed at preventing infectious diseases whilst conserving immunological tolerance. The strength of evidence for the positive effect of probiotic administration on acquired immune responses has come from various studies with viral and bacterial vaccines. We posit that the introduction early of probiotics may provide significant beneficial immune outcomes in neonates prior to commencing a vaccination schedule or in elderly adults prior to the administration of vaccinations against influenza viruses.

[Adverse reactions to metal orthopedic implants after knee arthroplasty]

Based on several clinical examples, the range of adverse or hypersensitive reactions to metal implants especially after total knee replacement are presented. In general, we found the patients to generally be women who present with pain, swelling, and local or generalized eczema. Some also present with early aseptic loosening mainly in the first 4 years after implantation. For these patients, a detailed allergy-specific history should be taken and a patch test should be performed; if necessary, blood ion levels should be evaluated to exclude cobaltism. Before revision surgery and exchange of the implant we always perform arthroscopic inspection to obtain biopsies for microbiology and histopathology. Using the Consensus Classification a good evaluation for planning revision with the different implant options is possible.

Probiotics, D-Lactic acidosis, oxidative stress and strain specificity

The existence of an implicit living microscopic world, composed primarily of bacteria, has been known for centuries. The exact mechanisms that govern the contribution of bacteria to human health and disease have only recently become the subject of intense research efforts. Within this very evident shift in paradigms, the rational design of probiotic formulations has led to the creation of an industry that seeks to progress the engineering of probiotic bacteria that produce metabolites that may enhance human host health and prevent disease. The promotion of probiotics is often made in the absence of quality scientific and clinically plausible data. The latest incursions into the probiotic market of claims have posited the amelioration of oxidative stress via potent antioxidant attributes or limiting the administration of probiotics to those species that do not produce D-Lactic acid (i.e., claims that D-Lactic acid acidosis is linked to chronic health conditions) or are strain-specific (shaping an industry point of difference) for appraising a therapeutic effect. Evidence-based research should guide clinical practice, as there is no place in science and medicine that supports unsubstantiated claims. Extravagant industry based notions continue to fuel the imprimatur of distrust and skepticism that is leveled by scientists and clinicians at an industry that is already rife with scientific and medical distrust and questionable views on probiotics. Ignoring scientifically discordant data, when sorting through research innovations and false leads relevant to the actions of probiotics, drives researcher discomfit and keeps the bar low, impeding the progress of knowledge. Biologically plausible posits are obligatory in any research effort; companies formulating probiotics often exhibit a lack of analytical understanding that then fuels questionable investigations failing to build on research capacity.

Role of Sphingosine-1-Phosphate in Transplant Vasculopathy Evoked by Anti-HLA Antibody

Transplant vasculopathy (TV) represents the main cause of late graft failure and limits the long-term success of organ transplantation. Cellular and humoral immune responses contribute to the pathogenesis of the concentric and diffuse intimal hyperplasia of arteries of the grafted organ. We recently reported that the mitogenic signaling, evoked in human vascular smooth muscle cells (hmSMC) by the anti-HLA class I monoclonal antibody W6/32, implicates neutral sphingomyelinase-2, suggesting a role for sphingolipids in intimal hyperplasia of TV. Here, we investigated whether the mitogenic sphingolipid, sphingosine-1-phosphate (S1P), is involved in intimal hyperplasia elicited by W6/32. Studies were done on cultured hmSMC and on an in vivo model of TV, consisting of human mesenteric arteries grafted into SCID/beige mice, injected weekly with W6/32. hmSMC migration and DNA synthesis elicited by W6/32 were inhibited by the sphingosine kinase-1 (SK1) inhibitor dimethylsphingosine, the anti-S1P antibody Sphingomab and the S1PR1/R3 inhibitor VPC23019. W6/32 stimulated SK1 activity, while siRNA silencing SK1, S1PR1 and S1PR3 inhibited hmSMC migration. In vivo, Sphingomab significantly reduced the intimal thickening induced by W6/32. These data emphasize the role of S1P in intimal hyperplasia elicited by the humoral immune response, and open perspectives for preventing TV with S1P inhibitors.

Fixation of the shorter cementless GTS™ stem: biomechanical comparison between a conventional and an innovative implant design

INTRODUCTION

Conventional cementless total hip arthroplasty already shows very good clinical results. Nevertheless, implant revision is often accompanied by massive bone loss. The new shorter GTS™ stem has been introduced to conserve femoral bone stock. However, no long-term clinical results were available for this implant. A biomechanical comparison of the GTS™ stem with the clinically well-established CLS(®) stem was therefore preformed to investigate the targeted stem philosophy.

MATERIALS AND METHODS

Four GTS™ stems and four CLS(®) stems were implanted in a standardized manner in eight synthetic femurs. A high-precision measuring device was used to determine micromotions of the stem and bone during different load applications. Calculation of relative micromotions at the bone-implant interface allowed the rotational implant stability and the bending behavior of the stem to be determined.

RESULTS

Lowest relative micromotions were detected near the lesser trochanter within the proximal part of both stems. Maximum relative micromotions were measured near the distal tip of the stems, indicating a proximal fixation of both stems. For the varus-valgus-torque application, a comparable stem bending behavior was shown for both stems.

CONCLUSION

Both stems seem to provide a comparable and adequate primary stability. The shortened GTS™ design has a comparable rotational stability and bone-implant flexibility compared to a conventional stem. This study demonstrates that the CLS(®) stem and the GTS™ stem exhibit similar biomechanical behavior. However, a clinical confirmation of these experimental results is still required.

[Different symptoms in patients with prostheses with metal-metal bearings]

Based on several clinical case examples, this article demonstrates the different symptoms and complications in patients fitted with prostheses with metal-on-metal (MoM) bearings. We recommend an annual clinical control for patients with MoM prostheses with a prosthesis head size of 36 mm or larger. In patients who have problems tests should be carried out to measure the metal ion levels of cobalt and chromium and the metal artifact-reduced sequence by magnetic resonance imaging (MRI) or if this is not possible an ultrasound investigation. The clinical investigations should specifically target asymptomatic local swellings or hardened sites and patients should be questioned on problems with general hypersensitivity reactions (skin rash), cardiomyopathy, neurological changes including sensory changes, renal function impairment and thyroid dysfunction.

[Revised consensus classification. Histopathological classification of diseases associated with joint endoprostheses]

The revised classification of the periprosthetic membrane (synovial-like interface membrane SLIM) encompasses all pathological alterations which can occur as a result of endoprosthetic replacement of major joints and lead to a reduction in durability of prostheses. This also includes the established consensus classification of SLIM by which aseptic and septic prosthetic loosening can be subdivided into four histological types and histopathological criteria for additional pathologies: endoprosthesis-associated arthrofibrosis, immunological/allergic alterations and osseous pathologies. This revision represents the foundation for the histopathological diagnostics of the total spectrum of diseases associated with joint prostheses, is a suitable basis for a standardized diagnostic procedure and etiological clarification of endoprosthesis failure and also as a data standard for endprosthesis registers, in particular for registers based on routine data (e.g. German endoprosthesis register).

Integration of left-right Pitx2 transcription and Wnt signaling drives asymmetric gut morphogenesis via Daam2

A critical aspect of gut morphogenesis is initiation of a leftward tilt, and failure to do so leads to gut malrotation and volvulus. The direction of tilt is specified by asymmetric cell behaviors within the dorsal mesentery (DM), which suspends the gut tube, and is downstream of Pitx2, the key transcription factor responsible for the transfer of left-right (L-R) information from early gastrulation to morphogenesis. Although Pitx2 is a master regulator of L-R organ development, its cellular targets that drive asymmetric morphogenesis are not known. Using laser microdissection and targeted gene misexpression in the chicken DM, we show that Pitx2-specific effectors mediate Wnt signaling to activate the formin Daam2, a key Wnt effector and itself a Pitx2 target, linking actin dynamics to cadherin-based junctions to ultimately generate asymmetric cell behaviors. Our work highlights how integration of two conserved cascades may be the ultimate force through which Pitx2 sculpts L-R organs.

New insights into the genetics of immune responses in rheumatoid arthritis

Rheumatoid arthritis (RA) is a common autoimmune disease with a strong genetic component. Numerous aberrant immune responses have been described during the evolution of the disease. In later years, the appearance of anti-citrullinated protein antibodies (ACPAs) has become a hallmark for the diagnosis and prognosis of RA. The post-translational transformation of arginine residues of proteins and peptides into citrulline (citrullination) is a natural process in the body, but for unknown reasons autoreactivity towards citrullinated residues may develop in disposed individuals. ACPAs are often found years before clinical manifestations. ACPAs are present in about 70% of RA patients and constitute an important disease marker, distinguishing patient groups with different prognoses and different responses to various treatments. Inside the human leukocyte antigen (HLA) region, some HLA-DRB1 alleles are strongly associated with their production. Genome-wide association studies in large patient cohorts have defined a great number of single nucleotide polymorphisms (SNPs) outside of the HLA region that are associated with ACPA positive (ACPA+) RA. The SNPs are generally located close to or within genes involved in the immune response or signal transduction in immune cells. Some environmental factors such as tobacco smoking are also positively correlated with ACPA production. In this review, we will describe the genes and loci associated with ACPA+ RA or ACPA- RA and attempt to clarify their potential role in the development of the disease.

Visualization of subcutaneous insulin injections by x-ray computed tomography

We report how the three-dimensional structure of subcutaneous injections of soluble insulin can be visualized by x-ray computed tomography using an iodine based contrast agent. The injections investigated are performed ex vivo in porcine adipose tissue. Full tomography scans carried out at a laboratory x-ray source with a total acquisition time of about 1 min yield CT-images with an effective pixel size of 109 × 109 μm². The depots are segmented using a modified Chan-Vese algorithm and we are able to observe differences in the shape of the injection depot and the position of the depot in the skin among equally performed injections. To overcome the beam hardening artefacts, which affect the quantitative prediction of the volume injected, we additionally present results concerning the visualization of two injections using synchrotron radiation. The spatial concentration distribution of iodine is calculated to show the dilution of the insulin drug inside the depot. Characterisation of the shape of the depot and the spatial concentration profile of the injected fluid is important knowledge when improving the clinical formulation of an insulin drug, the performance of injection devices and when predicting the effect of the drug through biomedical simulations.

X-ray tomography using the full complex index of refraction

We report on x-ray tomography using the full complex index of refraction recorded with a grating-based x-ray phase-contrast setup. Combining simultaneous absorption and phase-contrast information, the distribution of the full complex index of refraction is determined and depicted in a bivariate graph. A simple multivariable threshold segmentation can be applied offering higher accuracy than with a single-variable threshold segmentation as well as new possibilities for the partial volume analysis and edge detection. It is particularly beneficial for low-contrast systems. In this paper, this concept is demonstrated by experimental results.

Bronchopneumonia disguising lung metastases of a painless central chondrosarcoma of pubis

Chondrosarcoma is a generally locally malignant chondroid-forming bone tumor with a low potential for distant metastases. A small and completely painless central chondrosarcoma of pubis metastasizing to the lungs in a 63-year-old woman with bronchopneumonia is reported. Here we emphasize the mimicry and low growth of the chondrosarcoma and the easiness with which the diagnosis in completely asymptomatic patients can be missed. Although painless chondrosarcoma metastasizing to lung is rather rare, this tumor should be always included in the differential diagnosis of malignancies in this age category.

β2 -adrenergic receptor Thr164IIe polymorphism, blood pressure and ischaemic heart disease in 66 750 individuals

OBJECTIVES

The β(2) -adrenergic receptor (ADRB2) is located on smooth muscle cells and is an important regulator of smooth muscle tone. The Thr164Ile polymorphism (rs1800888) in the ADRB2 gene is rare but has profound functional consequences on receptor function and could cause lifelong elevated smooth muscle tone. We tested the hypothesis that Thr164Ile is associated with increased blood pressure, increased frequency of hypertension and increased risk of cardiovascular disease (CVD).

SUBJECTS

A total of 66 750 individuals from two large Danish general population studies were genotyped, and 1943 Thr164Ile heterozygotes and 16 homozygotes were identified.

RESULTS

Thr164Ile genotype was associated with increased systolic and diastolic blood pressure in women (trend: P = 0.04 and 0.02): systolic and diastolic blood pressure increased by 5% and 2%, respectively, in female homozygotes compared with female noncarriers. All female Thr164Ile homozygotes had hypertension compared with 58% of female heterozygotes and 54% of female noncarriers (chi-square: P = 0.001). Female Thr164Ile homozygotes and heterozygotes had odds ratios for ischaemic heart disease (IHD) of 2.93 (0.56-15.5) and 1.28 (1.03-1.61), respectively, compared with female noncarriers (trend: P = 0.007). These differences were not observed in men. Furthermore, Gly16Arg (rs1042713) and Gln27Glu (rs1042714) in the ADRB2 gene were not associated with blood pressure, hypertension or CVD either in the population overall or in women and men separately.

CONCLUSIONS

ADRB2 Thr164Ile is associated with increased blood pressure, increased frequency of hypertension and increased risk of IHD amongst women in the general population. These findings, particularly for homozygotes, are novel.

β2-adrenergic receptor polymorphisms, asthma and COPD: two large population-based studies

The β(2)-adrenergic receptor (ADRB2) is an important regulator of airway smooth muscle tone. We tested the hypothesis that three functional polymorphisms in the ADRB2 gene (Thr164Ile, Gly16Arg and Gln27Glu) are associated with reduced lung function, asthma or chronic obstructive pulmonary disease (COPD). We first genotyped 8,971 individuals from the Copenhagen City Heart Study for all three polymorphisms. To validate our findings, we genotyped an additional 53,777 individuals from the Copenhagen General Population Study for the Thr164Ile polymorphism. We identified 60,910 Thr164Ile noncarriers, 1,822 heterozygotes and 16 homozygotes. In the Copenhagen City Heart Study, the Thr164Ile genotype was associated with reduced forced expiratory volume in 1 s (FEV(1)) % predicted (trend p = 0.01) and FEV(1)/forced vital capacity (FVC) (p = 0.001): Thr164Ile heterozygotes had 3% and 2% reduced FEV(1) % pred and FEV(1)/FVC, respectively, compared with noncarriers. The odds ratio for COPD in Thr164Ile heterozygotes was 1.46 (95% CI 1.05-2.02). In the Copenhagen General Population Study, the Thr164 genotype associated with reduced FEV(1) % pred (p = 0.04) and FEV(1)/FVC (p < 0.001): Thr164Ile homozygotes and heterozygotes had 7% and 1% reduced FEV(1) % pred and 6% and 1% reduced FEV(1)/FVC, respectively, compared with noncarriers. The odds ratios for COPD in Thr164Ile homozygotes and heterozygotes were 4.53 (95% CI 1.54-13.3) and 1.07 (95% CI 0.92-1.25), respectively. Our results suggest that ADRB2 Thr164Ile is associated with reduced lung function and increased risk of COPD in the general population.