Effect of different cryopreservation media on human nucleus pulposus cells' viability and trilineage potential

Introduction: Low back pain (LBP) is a significant cause of disability in many countries, affecting more than half a billion people worldwide. In the past, progenitor cells have been found within the nucleus pulposus (NP) of the human intervertebral disc (IVD). However, in the context of cell therapy, little is known about the effect of cryopreservation and expansion on here called “heterogenic” human NP cells (hNPCs), and whether commercially available cryopreservation media are more efficient than “commonly used” media in terms of cell viability. Materials: In this study, hNPCs from four trauma patients (age 40.5 ± 14.3 years) and two patients with degenerated IVDs (age 24 and 46 years), undergoing spinal surgery, were collected. To isolate hNPCs, the tissue was digested with a mild two-step protocol. After subsequent expansion, hNPCs at passages 2-5 were separated and either cryo-preserved for 1 week at −150°C or differentiated into osteogenic, adipogenic, or chondrogenic lineages for 21 days. Cryopreservation was performed with five different media to compare their effect on the cell's viability and differentiation potential. Cell viability was determined with flow cytometry using propidium iodide and the trilineage differentiation potential was assessed by quantitative polymerase chain reaction and histological analysis. Results: After 1 week of cryopreservation, the hNPC's cell viability was comparable for all conditions, that is, independent of the cryopreservation medium used (82.3 ± 0.8% of cell viability). Furthermore, hNPCs from trauma patients showed some evidence for adipogenic and chondrogenic differentiation and at lower levels, this and evidence of osteogenic differentiation could be confirmed with hNPCs from degenerated discs. Moreover, cryopreservation did not affect the cell's differentiation potential in the majority of the cases tested. Conclusion: “Commonly used” cryopreservation media seem to perform just as well as commercially available media in terms of cell viability and the overall maintenance of the hNPCs trilineage differentiation potential

In Situ Cell Signalling of the Hippo-YAP/TAZ Pathway in Reaction to Complex Dynamic Loading in an Intervertebral Disc Organ Culture

Recently, a dysregulation of the Hippo-YAP/TAZ pathway has been correlated with intervertebral disc (IVD) degeneration (IDD), as it plays a key role in cell survival, tissue regeneration, and mechanical stress. We aimed to investigate the influence of different mechanical loading regimes, i.e., under compression and torsion, on the induction and progression of IDD and its association with the Hippo-YAP/TAZ pathway. Therefore, bovine IVDs were assigned to one of four different static or complex dynamic loading regimes: (i) static, (ii) “low-stress”, (iii) “intermediate-stress”, and (iv) “high-stress” regime using a bioreactor. After one week of loading, a significant loss of relative IVD height was observed in the intermediate- and high-stress regimes. Furthermore, the high-stress regime showed a significantly lower cell viability and a significant decrease in glycosaminoglycan content in the tissue. Finally, the mechanosensitive gene CILP was significantly downregulated overall, and the Hippo-pathway gene MST1 was significantly upregulated in the high-stress regime. This study demonstrates that excessive torsion combined with compression leads to key features of IDD. However, the results indicated no clear correlation between the degree of IDD and a subsequent inactivation of the Hippo-YAP/TAZ pathway as a means of regenerating the IVD

Reliability and Validity of the German Version of the AO Spine Patient Reported Outcome Spine Trauma Questionnaire.

STUDY DESIGN A single-center validation study. OBJECTIVE To translate and cross-culturally adapt the AO Spine PROST (Patient Reported Outcome Spine Trauma) into German, and to test its psychometric properties among German-speaking Swiss spine trauma patients. METHODS Patients were recruited from a level-1 Swiss trauma center. Next to the AO Spine PROST, the EQ-5D-3L questionnaire was used for concurrent validity. Questionnaires were filled out at two-time points for test-retest reliability. Patient characteristics were analyzed using descriptive statistics. For content validity, floor, and ceiling effects, as well as any irrelevant and missing questions were analyzed. Construct validity of the AO Spine PROST questionnaire to the EQ-5D-3L was tested using Spearman correlation tests. RESULTS The AOSpine PROST was translated and adapted into German using established guidelines. We included 179 patients. The floor effect for all items was well within the optimal range (below 15%), while the ceiling effect of seven items was within the optimal range. None of the items displayed a problematic floor or ceiling effect. The overall test-retest reliability of the total PROST score was excellent, with an ICC of .83 (95% CI .69-.91). The Spearman correlation coefficient between the total PROST summary score and EQ-5D-3 L was ρ = .63. CONCLUSIONS The German version of the AO Spine PROST questionnaire demonstrated very good validity and reliability results

Influence of Angiopoietin Treatment with Hypoxia and Normoxia on Human Intervertebral Disc Progenitor Cell’s Proliferation, Metabolic Activity, and Phenotype

Increasing evidence implicates intervertebral disc (IVD) degeneration as a major contributor to low back pain. In addition to a series of pathogenic processes, degenerated IVDs become vascularized in contrast to healthy IVDs. In this context, angiopoietin (Ang) plays a crucial role and is involved in cytokine recruitment, and anabolic and catabolic reactions within the extracellular matrix (ECM). Over the last decade, a progenitor cell population has been described in the nucleus pulposus (NP) of the IVD to be positive for the Tie2 marker (also known as Ang-1 receptor). In this study, we investigated the influence of Ang-1 and Ang-2 on human NP cell (Tie2+, Tie2- or mixed) populations isolated from trauma patients during 7 days in normoxia (21% O2) or hypoxia (≤ 5% O2). At the end of the process, the proliferation and metabolic activity of the NP cells were analyzed. Additionally, the relative gene expression of NP-related markers was evaluated. NP cells showed a higher proliferation depending on the Ang treatment. Moreover, the study revealed higher NP cell metabolism when cultured in hypoxia. Additionally, the relative gene expression followed, with an increase linked to the oxygen level and Ang concentration. Our study comparing different NP cell populations may be the start of new approaches for the treatment of IVD degeneration

Anterior thoracolumbar column reconstruction with the vertebral body stent-safety and efficacy.

PURPOSE The aim of this study was to assess safety and efficacy of vertebral body stenting (VBS) by analyzing (1) radiographic outcome, (2) clinical outcome, and (3) perioperative complications in patients with vertebral compression fractures treated with VBS at minimum 6-month follow-up. METHODS In this retrospective cohort study, 78 patients (61 ± 14 [21-90] years; 67% female) who have received a vertebral body stent due to a traumatic, osteoporotic or metastatic thoracolumbar compression fracture at our hospital between 2012 and 2020 were included. Median follow-up was 0.9 years with a minimum follow-up of 6 months. Radiographic and clinical outcome was analyzed directly, 6 weeks, 12 weeks, 6 months postoperatively, and at last follow-up. RESULTS Anterior vertebral body height of all patients improved significantly by mean 6.2 ± 4.8 mm directly postoperatively (p < 0.0001) and remained at 4.3 ± 5.1 mm at last follow-up compared to preoperatively (p < 0.0001). The fracture kyphosis angle of all patients improved significantly by mean 5.8 ± 6.9 degrees directly postoperatively (p < 0.0001) and remained at mean 4.9 ± 6.9 degrees at last follow-up compared to preoperatively (p < 0.0001). The segmental kyphosis angle of all patients improved significantly by mean 7.1 ± 7.6 degrees directly postoperatively (p < 0.0001) and remained at mean 2.8 ± 7.8 degrees at last follow-up compared to preoperatively (p = 0.03). Back pain was ameliorated from a preoperative median Numeric Rating Scale value of 6.5 to 3.0 directly postoperatively and further bettered to 1.0 six months postoperatively (p = 0.0001). Revision surgery was required in one patient after 0.4 years. CONCLUSION Vertebral body stenting is a safe and effective treatment option for osteoporotic, traumatic and metastatic compression fractures

Epidemiologic analysis of 8000 acute vertebral fractures: evolution of treatment and complications at 10-year follow-up.

STUDY DESIGN This is a retrospective cohort study. OBJECTIVES This study aims to determine the proportional incidence, clinical characteristics, treatment patterns with complications and changes in treatment of vertebral fractures over 10 years at a Swiss university hospital. METHODS A retrospective cohort study was performed. All patients with an acute vertebral fracture were included in this study. The extracted anonymized data from the medical records were manually assessed. Demographic data, exact location, etiology, type of treatment and complications related to the treatment were obtained. RESULTS Of 330,225 treated patients, 4772 presented with at least one vertebral fracture. In total 8307 vertebral fractures were identified, leading to a proportional incidence of 25 vertebral fractures in 1000 patients. Fractures were equally distributed between genders. Male patients were significantly younger and more likely to sustain a traumatic fracture, while female patients more commonly presented with osteoporotic fractures. The thoracolumbar junction (Th11-L2) was the most frequent fracture site in all etiologies. More than two-thirds of vertebral fractures were treated surgically (68.6%). Out of 4622 performed surgeries, we found 290 complications (6.3%). The odds for surgical treatment in osteoporotic fractures were two times higher before 2010 compared to 2010 and after (odds ratio: 2.1, 95% CI 1.5-2.9, p < 0.001). CONCLUSION Twenty-five out of 1000 patients presented with a vertebral fracture. More than 4000 patients with over 8307 vertebral body fractures were treated in 10 years. Over two-thirds of all fractures were treated surgically with 6.3% complications. There was a substantial decrease in surgeries for osteoporotic fractures after 2009

Reliability and Validity of the German Version of the AO Spine Patient Reported Outcome Spine Trauma Questionnaire

Study Design: A single-center validation study. Objective: To translate and cross-culturally adapt the AO Spine PROST (Patient Reported Outcome Spine Trauma) into German, and to test its psychometric properties among German-speaking Swiss spine trauma patients. Methods: Patients were recruited from a level-1 Swiss trauma center. Next to the AO Spine PROST, the EQ-5D-3L questionnaire was used for concurrent validity. Questionnaires were filled out at two-time points for test-retest reliability. Patient characteristics were analyzed using descriptive statistics. For content validity, floor, and ceiling effects, as well as any irrelevant and missing questions were analyzed. Construct validity of the AO Spine PROST questionnaire to the EQ-5D-3L was tested using Spearman correlation tests. Results: The AOSpine PROST was translated and adapted into German using established guidelines. We included 179 patients. The floor effect for all items was well within the optimal range (below 15%), while the ceiling effect of seven items was within the optimal range. None of the items displayed a problematic floor or ceiling effect. The overall test-retest reliability of the total PROST score was excellent, with an ICC of.83 (95% CI.69-.91). The Spearman correlation coefficient between the total PROST summary score and EQ-5D-3 L was ρ =.63. Conclusions: The German version of the AO Spine PROST questionnaire demonstrated very good validity and reliability results

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication