The impact of divergent forms of social support on health-related quality of life in patients with multiple myeloma and its precursor states

PURPOSE

Multiple myeloma is a largely incurable disease. Patients suffer from the cancer, therapeutic side effects, and often psychological symptoms. Not only multiple myeloma patients but also patients with precursor diseases show high psychological distress. Today, treatment option evaluations are increasingly performed in combination with health-related quality of life (HRQoL) assessments. One factor that is positively associated with HRQoL is social support.

METHODS

Our recent study used questionnaires (EORTC QLQ-C30, EORTC QLQ-MY20, Illness-specific Social Support Scale) to investigate the influence of positive and negative aspects of social support on HRQoL in patients with multiple myeloma and its precursors.

RESULTS

Multiple linear regression analyses with sex, age, treatment line, hemoglobin level, and number of comorbidities as control variables show that positive social support had a significant beneficial association with emotional function (β = 0.323) and social function (β = 0.251). Detrimental interactions had a significant negative association with social function (β =  - 0.209) and a significant positive association with side effects of treatment (β = 0.266).

CONCLUSION

Therefore, screening for social support and, if needed, psycho-oncological care can be an important resource and should be implemented in routine care.

CLINICAL TRIAL REGISTRATION

This study was registered with clinicaltrials.gov (NCT04328038).

A precision-based exercise program for patients with multiple myeloma

OBJECTIVES

Aim of this study was to retrospectively evaluate an interdisciplinary consultation followed by a precision-based exercise program (PEP) for myeloma patients with stable and unstable bone lesions.

METHODS

Data of myeloma patients (n = 100) who received a PEP according to an orthopedic evaluation were analyzed. Bone stability was assessed by established scoring systems (Spinal Instability Neoplastic Score [SINS], Mirels' score). All patients with stable and unstable osteolyses received a PEP and n = 91 were contacted for a follow-up interview.

RESULTS

In 60% of patients at least one osteolysis of the spine was considered potentially unstable or unstable. Following consultation, the number of patients performing resistance training could be significantly increased (≥2 sessions/week, 55%). Musculoskeletal pain was reported frequently. At the follow-up interview, 75% of patients who performed PEP stated that painful symptoms could be effectively alleviated by exercise. Moreover, only patients who exercised regularly discontinued pain medication. No injuries were reported in association with PEP.

CONCLUSION

We were able to demonstrate that individualized resistance training is implementable and safe for myeloma patients. By means of a PEP, patients' self-efficacy in managing musculoskeletal pain was enhanced and pain medication could be reduced.

The effect of surgical suture material on osteoclast generation and implant-loosening

Background: Implant loosening - either infectious or aseptic- is a still a major complication in the field of orthopaedic surgery. In both cases, a pro-inflammatory peri-prosthetic environment is generated by the immune system - either triggered by bacteria or by implant wear particles - which leads to osteoclast differentiation and osteolysis. Since infectious cases in particular often require multiple revision surgeries, we wondered whether commonly used surgical suture material may also activate the immune system and thus contribute to loss of bone substance by generation of osteoclasts. Methods: Tissue samples from patients suffering from infectious implant loosening were collected intraoperatively and presence of osteoclasts was evaluated by histopathology and immunohistochemistry. Further on, human monocytes were isolated from peripheral blood and stimulated with surgical suture material. Cell supernatant samples were collected and ELISA analysis for the pro-inflammatory cytokine IL-8 was performed. These experiments were additionally carried out on ivory slices to demonstrate functionality of osteoclasts. Whole blood samples were incubated with surgical suture material and up-regulation of activation-associated cell surface markers CD11b and CD66b on neutrophils was evaluated by flow cytofluorometry analysis. Results: We were able to demonstrate that multinucleated giant cells form in direct vicinity to surgical suture material. These cells stained positive for cathepsin K, which is a typical protease found in osteoclasts. By in vitro analysis, we were able to show that monocytes differentiated into osteoclasts when stimulated with surgical suture material. Resorption pits on ivory slices provided proof that the osteoclasts were functional. Release of IL-8 into cell supernatant was increased after stimulation with suture material and was further enhanced if minor amounts of bacterial lipoteichoic acid (LTA) were added. Neutrophils were also activated by surgical suture material and up-regulation of CD11b and CD66b could be seen. Conclusion: We were able to demonstrate that surgical suture material induces a pro-inflammatory response of immune cells which leads to osteoclast differentiation, in particular in combination with bacterial infection. In conclusion, surgical suture material -aside from bacteria and implant wear particles- is a contributing factor in implant loosening.

Bacterial Biofilm Components Induce an Enhanced Inflammatory Response Against Metal Wear Particles

Purpose

Aseptic implant loosening is still a feared complication in the field of orthopaedics. Presumably, a chronic inflammatory response is induced by wear particles, which leads to osteoclast generation, bone degradation and hence loosening of the implant. Since it has been demonstrated in the literature that most implants are in fact colonized by bacteria, the question arises whether aseptic implant loosening is truly aseptic. The aim of this study was to investigate a possibly enhanced inflammatory response to metal wear particles in the context of subclinical infection.

Patients and Methods

Tissue samples were collected intra-operatively from patients undergoing implant-exchange surgery due to aseptic loosening. Histopathological analysis was performed, as well as gene expression analysis for the pro-inflammatory cytokine Interleukin-8. By a series of in vitro experiments, the effect of metal wear particles on human monocytes, polymorphonuclear neutrophiles and osteoblasts was investigated. Additionally, minor amounts of lipoteichoic acid (LTA) and the bacterial heat shock protein GroEL were added.

Results

Histopathology of tissue samples revealed an accumulation of metal wear particles, as well as a cellular infiltrate consisting predominately of mononuclear cells. Furthermore, high expression of IL-8 could be detected in tissue surrounding the implant. Monocytes and osteoblasts in particular showed an increased release of IL-8 after stimulation with metal wear particles and in particular after stimulation with bacterial components and wear particles together.

Conclusion

We were able to show that minor amounts of bacterial components and metal wear particles together induce an enhanced inflammatory response in human monocytes and osteoblasts. This effect could significantly contribute to the generation of bone-resorbing osteoclasts and hence implant-loosening.

Ability of chlorhexidine, octenidine, polyhexanide and chloroxylenol to inhibit metabolism of biofilm-forming clinical multidrug-resistant organisms

Purpose

This in vitro study was designed to determine if standard antiseptics used for skin and environmental surface cleansing can disrupt the metabolic activity (as a measure of viability) of multidrug-resistant gram-negative bacteria, methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus isolates within their native biofilms.

Methods

Sixty clinical isolates of multidrug-resistant bacteria were selected for testing in different chlorhexidine gluconate, octenidine, polyhexanide and chloroxylenol concentrations. Metabolic inhibition of biofilm for each clinical isolate was analysed using a biofilm viability assay.

Results

Chlorhexidine gluconate (mean = 83.8% ± 9.8%) and octenidine (mean = 84.5% ± 6.8%) showed the greatest efficacy against biofilms of the tested microorganisms, with the greatest efficacies against MRSA. The antiseptics demonstrated the least efficacy against biofilms of Pseudomonas aeruginosa.

Conclusion

Chlorhexidine gluconate and octenidine showed the greatest level of bacterial metabolic inhibition and were statistically equivalent. Polyhexanide was more effective than chloroxylenol, but both were inferior to chlorhexidine gluconate and octenidine against the tested organisms.

IgY Targeting Bacterial Quorum-Sensing Molecules in Implant-Associated Infections

Background: Implant-associated infections are still a major complication in the field of orthopedics. Bacteria can form biofilms on implant surfaces, making them more difficult to detect and treat. Since standard antibiotic therapy is often impaired in biofilm infections, particular interest is directed towards finding treatment alternatives. Biofilm-formation is a well-organized process during which bacteria communicate via quorum-sensing molecules (QSM). The aim of this study was to inhibit bacterial communication by directing avian IgY against specific QSM. Methods: Chicken were immunized against the following QSM: (1) AtlE, a member of the autolysin family which mediates attachment to a surface in Staphylococcus epidermidis; (2) GroEL, the bacterial heat shock protein; (3) PIA (polysaccharide intercellular adhesion), which is essential for cell–cell adhesion in biofilms. Staphylococcus epidermidis biofilms were grown and inhibition of biofilm-formation by IgYs was evaluated. Additionally, human osteoblasts were cultivated and biocompatibility of IgYs was tested. Results: We were able to demonstrate that all IgYs reduced biofilm-formation, also without prior immunization. Therefore, the response was probably not specific with regard to the QSM. Osteoblasts were activated by all IgYs which was demonstrated by microscopy and an increased release of IL-8. Conclusions: In conclusion, avian IgY inhibits biofilm-formation, though the underlying mechanism is not yet clear. However, adverse effects on local tissue cells (osteoblasts) were also observed.

Quantitative sensory testing in physically active individuals and patients who underwent multidisciplinary pain therapy in the longitudinal course

Objective

The aim of this study was to evaluate possible differences of quantitative sensory testing (QST) results in healthy individuals (group control, n=20), physically active individuals (group sport, n=30) and in patients suffering from chronic musculoskeletal pain (group pain, n=30).

Methods

Thermal detection thresholds, thermal pain thresholds and blunt pressure pain thresholds were measured at various sites (T0). Additionally, group pain was treated in multidisciplinary pain therapy for 4 weeks. All groups were retested after 4 weeks to evaluate the reliability of QST measurements and to investigate possible early changes following treatment (T1).

Results

Importantly, QST-measurements showed stable test results for group sport and group control at both time points. Athletes demonstrated the highest pain thresholds in general (cold pain threshold mean in degree Celsius for the hand: 5.76, lower back right: 7.25, lower back left: 7.53; heat pain threshold mean in degree Celsius for the hand: 46.08, lower back right: 45.77, lower back left: 45.70; and blunt pressure pain mean in kilograms for the hand: 3.54, lower back right: 5.26, lower back left: 5.46). Patients who underwent therapy demonstrated significant differences at T1 (cold pain threshold hand mean in degree Celsius for the hand: 11.12 [T0], 15.12 [T1]; and blunt pressure pain mean in kilograms for the lower back right: 2.87 [T0], 3.56 [T1]). They were capable of enduring higher blunt pressure, but on the other hand cold pain tolerance had decreased (P=0.045 and P=0.019, respectively).

Conclusions

In conclusion, we were able to demonstrate significant differences of QST results among the three groups and we detected early changes following multidisciplinary pain therapy, which will be discussed.

Changes in the microarchitecture of the pancreatic cancer stroma are linked to neutrophil-dependent reprogramming of stellate cells and reflected by diffusion-weighted magnetic resonance imaging

In pancreatic cancer (PDAC) intratumor infiltration of polymorphonuclear neutrophils (PMN) is associated with histologically apparent alterations of the tumor growth pattern. The aim of this study was to examine possible associations between PMN infiltration, tumor microarchitecture, and water diffusivity in diffusion-weighted magnetic resonance imaging (DW-MRI), and to further asses the underlying mechanisms.

Methods: DW-MRI was performed in 33 PDAC patients prior to surgery. In parallel, tissue specimen were examined histologically for growth pattern, azurocidin-positive PMN infiltrates, and the presence of alpha-smooth muscle actin (α-SMA) and metalloproteinase 9 (MMP9)-positive myofibroblastic cells. For confirmation of the histological findings, a tissue microarray of a second cohort of patients (n=109) was prepared and examined similarly. For in vitro studies, the pancreatic stellate cell line RLT was co-cultivated either with isolated PMN, PMN-lysates, or recombinant azurocidin and characterized by Western blot, flow cytometry, and proteome profiler arrays.

Results: Tumors with high PMN density showed restricted water diffusion in DW-MRI and histologic apparent alterations of the tumor microarchitecture (microglandular, micropapillary, or overall poorly differentiated growth pattern) as opposed to tumors with scattered PMN. Areas with altered growth pattern lacked α-SMA-positive myofibroblastic cells. Tissue microarrays confirmed a close association of high PMN density with alterations of the tumor microarchitecture and revealed a significant association of high PMN density with poor histologic grade of differentiation (G3). In vitro experiments provided evidence for direct effects of PMN on stellate cells, where a change to a spindle shaped cell morphology in response to PMN and to PMN-derived azurocidin was seen. Azurocidin incorporated into stellate cells, where it associated with F-actin. Down-regulation of α-SMA was seen within hours, as was activation of the p38-cofilin axis, up-regulation of MMP9, and acquisition of intracellular lipid droplets, which together indicate a phenotype switch of the stellate cells.

Conclusion: In PDAC, PMN infiltrates are associated with alterations of the tumor microarchitecture. As a causal relationship, we propose a reprogramming of stellate cells by PMN-derived azurocidin towards a phenotype, which affects the microarchitecture of the tumor.

Surgical site infections following instrumented stabilization of the spine

Background

Implant-associated infections are still a feared complication in the field of orthopedics. Bacteria attach to the implant surface and form so-called biofilm colonies that are often difficult to diagnose and treat. Since the majority of studies focus on prosthetic joint infections (PJIs) of the hip and knee, current treatment options (eg, antibiotic prophylaxis) of implant-associated infections have mostly been adapted according to these results.

Objective

The aim of this study was to evaluate patients with surgical site infections following instrumented stabilization of the spine with regard to detected bacteria species and the course of the disease.

Patients and methods

We performed a retrospective single-center analysis of implant-associated infections of the spine from 2010 to 2014. A total of 138 patients were included in the study. The following parameters were evaluated: C-reactive protein serum concentration, microbiological evaluation of tissue samples, the time course of the disease, indication for instrumented stabilization of the spine, localization of the infection, and the number of revision surgeries required until cessation of symptoms.

Results

Coagulase-negative Staphylococcus spp. were most commonly detected (n=69, 50%), followed by fecal bacteria (n=46, 33.3%). In 23.2% of cases, no bacteria were detected despite clinical suspicion of an infection. Most patients suffered from degenerative spine disorders (44.9%), followed by spinal fractures (23.9%), non-degenerative scoliosis (20.3%), and spinal tumors (10.1%). Surgical site infections occurred predominantly within 3 months (64.5%), late infections after 2 years were rare (4.3%), in particular when compared with PJIs. Most cases were successfully treated after 1 revision surgery (60.9%), but there were significant differences between bacteria species. Fecal bacteria were more difficult to treat and often required more than 1 revision surgery.

Conclusion

In summary, we were able to demonstrate significant differences between spinal implant-associated infections and PJIs. These aspects should be considered early on in the treatment of surgical site infections following instrumented stabilization of the spine.

The Not-So-Good Prognosis of Streptococcal Periprosthetic Joint Infection Managed by Implant Retention: The Results of a Large Multicenter Study

BACKGROUND.

Streptococci are not an infrequent cause of periprosthetic joint infection (PJI). Management by debridement, antibiotics, and implant retention (DAIR) is thought to produce a good prognosis, but little is known about the real likelihood of success.

METHODS.

A retrospective, observational, multicenter, international study was performed during 2003-2012. Eligible patients had a streptococcal PJI that was managed with DAIR. The primary endpoint was failure, defined as death related to infection, relapse/persistence of infection, or the need for salvage therapy.

RESULTS.

Overall, 462 cases were included (median age 72 years, 50% men). The most frequent species was Streptococcus agalactiae (34%), and 52% of all cases were hematogenous. Antibiotic treatment was primarily using β-lactams, and 37% of patients received rifampin. Outcomes were evaluable in 444 patients: failure occurred in 187 (42.1%; 95% confidence interval, 37.5%-46.7%) after a median of 62 days from debridement; patients without failure were followed up for a median of 802 days. Independent predictors (hazard ratios) of failure were rheumatoid arthritis (2.36), late post-surgical infection (2.20), and bacteremia (1.69). Independent predictors of success were exchange of removable components (0.60), early use of rifampin (0.98 per day of treatment within the first 30 days), and long treatments (≥21 days) with β-lactams, either as monotherapy (0.48) or in combination with rifampin (0.34).

CONCLUSIONS.

This is the largest series to our knowledge of streptococcal PJI managed by DAIR, showing a worse prognosis than previously reported. The beneficial effects of exchanging the removable components and of β-lactams are confirmed and maybe also a potential benefit from adding rifampin.

Patients' safety: is there a systemic release of gentamicin by gentamicin-coated tibia nails in clinical use?

INTRODUCTION

Osteitis is one of the most serious complications in orthopedic surgery. Expert Tibia Nail (ETN) PROtect™ coated with a biodegradable layer of gentamicin-laden polymer was developed for prophylaxis of osteomyelitis. In systemic administration, gentamicin has only a small therapeutic index and serious side effects; it is potentially nephrotoxic as well as ototoxic. It is not yet known if relevant gentamicin concentrations are released into the systemic circulation after implantation of gentamicin-coated nails. In order to evaluate the patients' risks profiles and increase patient safety, we measured gentamicin levels in pre- and postoperative serum samples of patients undergoing implantation of ETN PROtect.

METHODS

Twenty-five patients who received ETN PROtect between March 2012 and August 2014 were included in this study. Collection of blood samples occurred before the operation, at weeks 1-4, 3 and 6 months, and up to 1 year after the implantation. Measurement of gentamicin levels in serum samples was performed at the central laboratory of Heidelberg University Hospital. Additionally, laboratory parameters, C-reactive protein, leukocyte number, urea and creatinine concentrations were analyzed in routine controls before and after operating and assessed for systemic side effects.

RESULTS

Over the course of this prospective observational study, we were able to determine that gentamicin-coated nails do not release gentamicin into the systemic circulation above the lowest detectable level of 0.2 mg/dL. There were slight increases in the mean inflammation and renal retention markers, but no gentamicin-associated side effects could be linked to implantation. Furthermore, no allergic reactions could be detected during our study.

CONCLUSION

Our findings suggest that there is no relevant release of gentamicin into the systemic circulation causing a systemic effect, and serious side effects due to gentamicin-coated tibia nails should not be feared. Postoperative monitoring of renal function does not seem necessary because of the implantation of ETN PROtect.

The osteoblast as an inflammatory cell: production of cytokines in response to bacteria and components of bacterial biofilms

BACKGROUND

Implant infections are a major complication in the field of orthopaedics. Bacteria attach to the implant-surface and form biofilm-colonies which makes them difficult to treat. Not only immune cells exclusively respond to bacterial challenges, but also local tissue cells are capable of participating in defense mechanisms. The aim of this study was to evaluate the role of osteoblasts in the context of implant infections.

METHODS

Primary osteoblasts were cultivated and stimulated with free-swimming bacteria at 4 °C and 37 °C. Supernatants were harvested for ELISA and expression of pro-inflammatory cytokines evaluated by RT-PCR. Bacterial binding to osteoblasts was evaluated using cytofluorometry and uptake was investigated by (3)H thymidine-labelling of bacteria. Osteoblasts were additionally stimulated with the extracellular polymeric substance (EPS) of Staphylococcus epidermidis biofilms, as well as components of the EPS; the bacterial heat shock protein GroEL in particular.

RESULTS

We demonstrated that binding of bacteria to the osteoblast cell surface leads to an increased production of pro-inflammatory cytokines. Bacteria are capable of surviving intracellular. Furthermore, osteoblasts do not only respond to free-swimming, planktonic bacteria, but also to components of the EPS, including lipoteichoic acid and the heat shock protein GroEL.

CONCLUSION

In conclusion, local tissue cells, specifically osteoblasts, might contribute to the persistence of the inflammatory response associated with implant-infections.

Innate Immune Response in Implant-Associated Infections: Neutrophils against Biofilms

Biofilm has been recognized as a well-protected form of living for bacteria, contributing to bacterial pathogenicity, particularly for opportunistic species. Biofilm-associated infections are marked by their persistence. Extensive research has been devoted to the formation and composition of biofilms. The immune response against biofilms remains rather unexplored, but there is the notion that bacteria within a biofilm are protected from host defences. Here we glance at the mechanisms by which neutrophils recognize and face biofilms in implant infections and discuss the implications of this interplay, as well as speculate on its significance.

Activation of phagocytic cells by Staphylococcus epidermidis biofilms: effects of extracellular matrix proteins and the bacterial stress protein GroEL on netosis and MRP-14 release

The recognition and phagocytosis of free-swimming (planktonic) bacteria by polymorphonuclear neutrophils have been investigated in depth. However, less is known about the neutrophil response towards bacterial biofilms. Our previous work demonstrated that neutrophils recognize activating entities within the extracellular polymeric substance (EPS) of biofilms (the bacterial heat shock protein GroEL) and that this process does not require opsonization. Aim of this study was to evaluate the release of DNA by neutrophils in response to biofilms, as well as the release of the inflammatory cytokine MRP-14. Neutrophils were stimulated with Staphylococcus epidermidis biofilms, planktonic bacteria, extracted EPS and GroEL. Release of DNA and of MRP-14 was evaluated. Furthermore, tissue samples from patients suffering from biofilm infections were collected and evaluated by histology. MRP-14 concentration in blood samples was measured. We were able to show that biofilms, the EPS and GroEL induce DNA release. MRP-14 was only released after stimulation with EPS, not GroEL. Histology of tissue samples revealed MRP-14 positive cells in association with neutrophil infiltration and MRP-14 concentration was elevated in blood samples of patients suffering from biofilm infections. Our data demonstrate that neutrophil-activating entities are present in the EPS and that GroEL induces DNA release by neutrophils.

Sensing developing biofilms: the bitter receptor T2R38 on myeloid cells

Quorum-sensing molecules, also known as autoinducer, are essential for bacterial biofilm formation. Our focus is on N-(3-oxododecanoyl)-L-homoserine lactone (AHL-12), because it is also known as an ‘interkingdom signalling molecule’, which means that it also interacts with mammalian cells. AHL-12 activates defence-relevant functions of phagocytic cells, including enhancement of phagocytosis, increased expression of adhesion receptors and induction of chemotaxis. This leads to the hypothesis that early recognition of developing biofilms might be the key to a successful host defence against biofilm infection. In that context we studied activation of phagocytic cells by AHL-12, and found that phagocytes are activated via a rather specialized receptor that was not previously described on myeloid cells, the bitter taste receptor T2R38. Taste receptors are commonly associated with cells of the gustatory system. The extragustatory expression, however, suggests an additional role, namely the sensing of the onset of bacterial biofilm infection.

Myeloid cells express the bitter taste receptor T2R38 als ligand for the quorum-sensing molecule of Pseudomonas aeruginosa N-(3-oxododecanoyl)-L-homoserine lactone (AHL-12).

Are atrophic long-bone nonunions associated with low-grade infections?

Impaired fracture healing, especially when associated with bacterial infection, is a severe complication following long-bone fractures and requires special treatment. Because standard diagnostic techniques might provide falsely negative results, we evaluated the sonication method for detection of bacteria on implants of patients with fracture nonunions. A total of 49 patients with a nonunion (group NU) and, for comparison, 45 patients who had undergone routine removal of osteosynthetic material (group OM), were included in the study. Five different diagnostic methods (culture of tissue samples, culture of intraoperative swabs, histopathology of tissue samples, culture of sonication fluid, and 16S ribosomal DNA polymerase chain reaction of sonication fluid) were compared and related to clinical data. Among the diagnostic tests, culture of sonication fluid demonstrated by far the highest detection rate of bacteria (57%) in group NU, and rather unexpectedly 40% in group OM. Culture of sonication samples also revealed a broad spectrum of bacteria, in particular Propionibacterium spp. In conclusion, our results indicate that more bacteria can be detected on implants of patients with atrophic nonunions of long-bone fractures by means of the sonication procedure, which provides a valuable additional diagnostic tool to decide on a surgical procedure (eg, two-step procedure) and to further specify antimicrobial therapy.

Neutrophil-derived MRP-14 is up-regulated in infectious osteomyelitis and stimulates osteoclast generation

Bone infections of patients with joint replacement by endoprosthesis (so called "periprosthetic joint infection") pose a severe problem in the field of orthopedic surgery. The diagnosis is often difficult, and treatment is, in most cases, complicated and prolonged. Patients often require an implant exchange surgery, as the persistent infection and the accompanying inflammation lead to tissue damage with bone degradation and consequently, to a loosening of the implant. To gain insight into the local inflammatory process, expression of the proinflammatory cytokine MRP-14, a major content of neutrophils, and its link to subsequent bone degradation was evaluated. We found MRP-14 prominently expressed in the affected tissue of patients with implant-associated infection, in close association with the chemokine CXCL8 and a dense infiltrate of neutrophils and macrophages. In addition, the number of MRP-14-positive cells correlated with the presence of bone-resorbing osteoclasts. MRP-14 plasma concentrations were significantly higher in patients with implant-associated infection compared with patients with sterile inflammation or healthy individuals, advocating MRP-14 as a novel diagnostic marker. A further biologic activity of MRP-14 was detected: rMRP-14 directly induced the differentiation of monocytes to osteoclasts, thus linking the inflammatory response in implant infections with osteoclast generation, bone degradation, and implant loosening.

Infectious versus non-infectious loosening of implants: activation of T lymphocytes differentiates between the two entities

PURPOSE

Loosening of implants occurs mainly for two reasons: bacterial infection of the implant or "aseptic loosening" presumably due to wear particles derived from the implant. To gain further insight into the pathomechanism, we analysed activation of the T cell response in these patients.

METHODS

Activation of peripheral T lymphocytes was determined by cytofluorometry as down-regulation of CD28 and up-regulation of CD11b. In addition, tissue samples obtained during surgery were analysed by quantitative RT-PCR for gene expression of CD3, CD14 and cathepsin K, as markers for T cells, monocytes/macrophages or osteoclasts, respectively.

RESULTS

Activated T lymphocytes were detected in patients with infection but not in patients with aseptic loosening. Gene expression of CD3 was significantly enhanced in tissues of patients with infection compared to those with aseptic loosening. Expression of CD14 and of cathepsin K did not differ between the two groups.

CONCLUSION

Implant-associated infection and aseptic loosening are associated with a local inflammatory response, which eventually results in osteoclastogenesis and bone resorption. Systemic T cell activation, in contrast, occurs only in patients with implant-associated infection, and hence analysis of T cell activation markers could serve as a diagnostic tool to differentiate between the two entities.

A persistent case of tuberculosis of the pubic symphysis and pubic bone

A case of a patient suffering from tuberculosis of the pubic symphysis and pubic bone is presented. There were no symptoms other than pain in the right groin area for 12 months. An X-ray of the pelvis showed an osteodestructive lesion of the pubic bone, and an MRI revealed an abscess formation of the pubic symphysis. Tissue samples were collected via CT-guided needle biopsy. Histological evaluation of tissue and analysis by PCR prompted the diagnosis of musculoskeletal tuberculosis. Despite antituberculous chemotherapy according to the current guidelines, the osteodestructive lesion progressed. This case highlights the difficulty of treating bone infections in general. Moreover, Mycobacterium tuberculosis as a rare causative agent of bone infections is discussed.

Osteoclast Generation and Cytokine Profile at Prosthetic Interfaces: A Study on Tissue of Patients with Aseptic Loosening or Implant-Associated Infections

Aseptic loosening of implants or loosening due to persistent bacterial infection remains a severe complication in orthopaedic surgery. To investigate underlying cellular and molecular mechanisms, particularly with regard to bone loss, tissue samples of patients requiring surgery were examined. By histological methods and by quantitative RT-PCR, respectively, infiltration of leukocytes, expression of osteoclast-typical genes and of proinflammatory cytokines was determined. Samples were taken directly from osteolytic sites and for comparison from adjacent sites, distant sites and from muscle. At osteolytic sites, cathepsin K and the metalloproteinases MMP1 and MMP9 were found, as was expression of inflammation-related cytokines, particularly of interleukin (IL)-1β, CXCL8, S100A9 and a very moderate expression of receptor activator of NfκB ligand (RANKL) and tumour necrosis factor (TNF) a. Of note, expression of these parameters gradually decreased from sites of osteolysis to adjacent tissue, to distant tissue to muscle. In patients with infection and osteolysis, expression of cytokines, notably of CXCL8, was markedly enhanced, especially in adjacent and distant tissues, where expression was 10- to 20-fold higher compared to tissue of aseptic patients. A possible source of CXCL8 could be infiltrated cells, particularly neutrophils, because they were found in infected tissue only. Histological examination of the biopsies revealed an additional CXCL8 source, namely endothelial cells of small blood vessels. In conclusion, aseptic loosening and implant-associated infection are associated with osteoclast generation and a local inflammatory response. The proinflammatory environment could promote the differentiation of precursor cells to osteoclasts, thereby linking inflammation to bone resorption. The higher expression of cytokines, particularly of CXCL8 in tissue of patients with bacterial infection, could explain the accelerated time course of bone resorption as it occurs in infection compared to aseptic loosening.

Necrotising fasciitis

A patient in his late 50s who suffered from necrotising fasciitis is described in this case report. The patient first presented at the chest pain unit, where he reported of respiratory distress and showed systemic signs of an infection. Because of progressive skin lesions indicative of necrotising fasciitis on both the lower extremities, the patient was immediately rushed into surgery and was treated at the intensive care unit. Despite receiving immediate treatment, the patient died of this rapidly spreading infectious disease. Because of the fast advance of this disease, we would like to emphasise the importance of early recognition of symptoms.

Prognostic value of laryngeal electromyography in vocal fold paralysis

OBJECTIVE

To analyze the value of electromyography in predicting recovery from acute neurogenic vocal fold paralysis.

STUDY DESIGN

Prospective case series.

SETTING

University-based hospital of otorhinolaryngology-head and neck surgery.

PATIENTS

Ninety-eight patients (56 women, with a mean age of 62.2 years; 42 men, with a mean age of 39.8 years) with 111 paralyzed vocal folds. The causes were varied, with thyroid surgery (53 cases) and idiopathic palsy (18 cases) being the predominant factors.

INTERVENTION

Prognostication was based on electromyography performed no earlier than 14 days after onset of palsy. Findings were classified as neurapraxy, axonotmesis, and neurotmesis. Prognosis is inherent in this classification, since neurapraxy is presumed to resolve completely within 8 to 12 weeks, whereas axonotmesis is most likely to be followed by impaired vocal fold mobility.

MAIN OUTCOME MEASURES

Vocal fold mobility after 6 months.

RESULTS

In 102 vocal folds, some palsy of various degree persisted after 6 months. Free mobility of the paralyzed vocal fold was restored in 9 cases. By means of laryngeal electromyography, defective recovery, defined as absence of completely free vocal fold mobility, was predicted correctly in 94.4% of cases (68/72). For complete recovery, prognosis was accurate in only 12.8% of cases (5/39).

CONCLUSIONS

The detection of neural degeneration by laryngeal electromyography allows the prediction of poor functional outcome with sufficient reliability in an early phase of the disease process. Conversely, the absence of signs of degeneration does not imply that complete recovery is to be expected.

A new mouse model for embryos with a hatching deficiency and its use to elucidate the mechanism of blastocyst hatching

OBJECTIVE

To develop an experimental model for embryos with a defect specific to hatching, with the purpose of clarifying the mammalian embryo hatching mechanism.

DESIGN

A microneedle was inserted under the zona pellucida (ZP) of mouse embryos, and either 1/2 or 1/4 of the blastomeres were mechanically destroyed. The remainder of embryos that developed into blastocysts were compared for hatching to controls wherein a microneedle was inserted and withdrawn without harming the embryo. Experiments were done to increase pressure within the perivitelline space to decrease the amount of ZP material to study the hatching mechanism.

SETTING

University-based basic research laboratory.

RESULTS

When 1/2 or 1/4 of the embryo was destroyed and the remaining cells developed into healthy blastocysts within the intact zona, hatching was significantly impaired, and zona thickness was markedly increased relative to controls. When a mineral oil droplet was inserted under the zona to enhance a possible mechanical component of hatching, manipulated embryos were not restored to normal hatching, and hatching of unmanipulated blastocysts was not improved. However, when the zona was circumferentially thinned by application of acid Tyrode's solution, the hatching defect in manipulated "3/4 embryos" was corrected.

CONCLUSION

Because it is known that embryos with cells reduced by 1/2 or 1/4 have normal developmental potential, we conclude that the inability of such embryos to hatch from an intact zona constitutes a mouse model for a defect specific to hatching. Moreover, results from mineral oil droplet insertion and circumferential thinning of the zona indicate that normal hatching is accomplished predominantly, if not entirely, by zona lysis, not by pressure exerted against the zona by the expanding blastocyst.

Restoration of normal implantation rates in mouse embryos with a hatching impairment by use of a new method of assisted hatching

OBJECTIVE

To use a newly developed mouse model for embryos with a hatching defect to develop improved methods of assisted hatching.

DESIGN

We had previously demonstrated that mouse embryos with reduced cell numbers, when resident within an intact zona, exhibit a hatching deficiency, and we used these "hatching-defective" embryos to demonstrate that hatching is mediated predominantly, if not entirely, by lysis of the zona pellucida. In the present study, the hatching-defective embryos were implanted into pseudo-pregnant females to determine if implantation rates were reduced. In addition, to compensate for reduced zona lysin production, the zonae of some embryos were circumferentially thinned with acid Tyrode's solution. The implantation rates and developmental potential of hatching-defective embryos subjected to zona thinning were compared with those of the hatching-defective embryos implanted without zona thinning.

SETTING

University-based basic research laboratory.

RESULTS

When hatching-defective embryos, created by destruction of 1/4 of the blastomeres at the four-cell stage, were implanted into pseudopregnant female mice, no pregnancies were established, and no implantation sites could be identified after transfer of 41 embryos. However, when hatching-defective embryos were subjected to zona thinning before ET, a normal rate of implantation was observed (18 implantation events of 49 embryos transferred). Fetuses appeared morphologically normal. The difference in implantation rates between hatching-defective embryos subjected to zona thinning and those not treated by zona thinning was highly significant by chi 2 analysis.

CONCLUSION

Failure of embryos with cell numbers reduced by micromanipulation to implant and restoration of normal implantation and development after circumferential zona thinning demonstrates that the developmental defect of the manipulated embryos is confined to hatching, and thus, that this procedure establishes a useful model for defective hatching. High rates of implantation after circumferential thinning of the zona shows that this procedure of assisted hatching is highly effective. These findings have important implications for use of assisted hatching in human IVF because the assisted hatching procedure is safe and effective and increases the efficiency of the normal hatching mechanism. Thus, the procedure may be useful in a wide variety of circumstances for which assisted hatching by zona opening has been found to be ineffective.