scholarly journals Active Rheumatoid Arthritis in a Mouse Model is not an Independent Risk Factor for Periprosthetic Joint Infection

2021 ◽  
Author(s):  
Rishi Trikha ◽  
Danielle Greig ◽  
Troy Sekimura ◽  
Nicolas Cevallos ◽  
Benjamin Kelley ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Risk Factor ◽  
Periprosthetic Joint Infection ◽  
Ex Vivo ◽  
Joint Infection ◽  
Bacterial Burden ◽  
Crystal Violet Assay ◽  
Significant Difference ◽  
Infectious Burden

Introduction Periprosthetic joint infection (PJI) represents a devastating complication of total joint arthroplasty associated with significant morbidity and mortality. Literature suggests a possible higher incidence of periprosthetic joint infection (PJI) in patients with rheumatoid arthritis (RA). There is, however, no consensus on this relative risk nor a well-defined mechanism of this purported risk. This study investigates how collagen-induced arthritis (CIA), a validated animal model of RA, impacts infectious burden in a well-established model of PJI.   Methods Control mice were compared against CIA mice. Whole blood samples were collected to quantify systemic IgG levels via ELISA. Ex vivo respiratory burst function was measured via dihydrorhodamine assay. Ex vivo Staphylococcus aureus Xen36 burden was measured directly via colony forming unit (CFU) counts and crystal violet assay to assess biofilm formation. In vivo , surgical placement of a titanium implant through the knee joint and inoculation with S. aureus Xen36 was performed. Bacterial burden was then quantified by longitudinal bioluminescent imaging.   Results Mice with CIA demonstrated significantly higher levels of systemic IgG compared with control mice (p = 0.003). Ex vivo, there was no significant difference in respiratory burst function (p=0.89) or S. aureus bacterial burden as measured by CFU counts (p=0.91) and crystal violet assay (p=0.96). In vivo , no significant difference in bacterial bioluminescence between groups was found at all postoperative time points. CFU counts of both the implant and the peri-implant tissue were not significantly different between groups (p=0.82 and 0.80, respectively).   Conclusion This study demonstrated no significant difference in S. aureus infectious burden between mice with CIA and control mice. These results suggest that untreated, active RA may not represent a significant intrinsic risk factor for PJI. Further mechanistic translational and clinical studies are, however, warranted to thoroughly investigate the infectious risk of RA.

scholarly journals Active rheumatoid arthritis in a mouse model is not an independent risk factor for periprosthetic joint infection

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0250910
Author(s):  
Rishi Trikha ◽  
Danielle Greig ◽  
Troy Sekimura ◽  
Nicolas Cevallos ◽  
Benjamin Kelley ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Risk Factor ◽  
Periprosthetic Joint Infection ◽  
Ex Vivo ◽  
Joint Infection ◽  
Bacterial Burden ◽  
Crystal Violet Assay ◽  
Significant Difference ◽  
Infectious Burden

Introduction Periprosthetic joint infection (PJI) represents a devastating complication of total joint arthroplasty associated with significant morbidity and mortality. Literature suggests a possible higher incidence of periprosthetic joint infection (PJI) in patients with rheumatoid arthritis (RA). There is, however, no consensus on this purported risk nor a well-defined mechanism. This study investigates how collagen-induced arthritis (CIA), a validated animal model of RA, impacts infectious burden in a well-established model of PJI. Methods Control mice were compared against CIA mice. Whole blood samples were collected to quantify systemic IgG levels via ELISA. Ex vivo respiratory burst function was measured via dihydrorhodamine assay. Ex vivo Staphylococcus aureus Xen36 burden was measured directly via colony forming unit (CFU) counts and crystal violet assay to assess biofilm formation. In vivo, surgical placement of a titanium implant through the knee joint and inoculation with S. aureus Xen36 was performed. Bacterial burden was then quantified by longitudinal bioluminescent imaging. Results Mice with CIA demonstrated significantly higher levels of systemic IgG compared with control mice (p = 0.003). Ex vivo, there was no significant difference in respiratory burst function (p = 0.89) or S. aureus bacterial burden as measured by CFU counts (p = 0.91) and crystal violet assay (p = 0.96). In vivo, no significant difference in bacterial bioluminescence between groups was found at all postoperative time points. CFU counts of both the implant and the peri-implant tissue were not significantly different between groups (p = 0.82 and 0.80, respectively). Conclusion This study demonstrated no significant difference in S. aureus infectious burden between mice with CIA and control mice. These results suggest that untreated, active RA may not represent a significant intrinsic risk factor for PJI, however further mechanistic translational and clinical studies are warranted.

scholarly journals The mildly decreased preoperative bilirubin level is a risk factor for periprosthetic joint infection after total hip and knee arthroplasty

Arthroplasty ◽  
2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Jun Fu ◽  
Xiyue Chen ◽  
Ming Ni ◽  
Xiang Li ◽  
Libo Hao ◽  
...  
Keyword(s):  
Risk Factor ◽  
Bilirubin Level ◽  
Knee Arthroplasty ◽  
Periprosthetic Joint Infection ◽  
Joint Infection ◽  
Primary Arthroplasty ◽  
Significant Difference ◽  
Serologic Markers ◽  
Hip And Knee Arthroplasty ◽  
Laboratory Biomarkers

Abstract Background Many serologic markers are routinely tested prior to joint arthroplasty, but only few are commonly used to guide surgeons in determining patients most at risk of periprosthetic joint infection (PJI). The objective of this study was to investigate the association between preoperative bilirubin level and PJI after primary hip and knee arthroplasty. Methods A retrospective analysis was performed on patients undergoing revision hip and knee arthroplasty at our hospital from January 2016 to December 2019. Laboratory biomarkers were collected before the primary arthroplasty, as well as general patient information. The association between the above serologic markers and postoperative PJI was analyzed. Results A total of 72 patients (30 hips/42 knees) were analyzed, including 39 patients with PJI and 33 patients without PJI. Except for total bilirubin (TB) and direct bilirubin (DB), there was no significant difference between the remaining laboratory biomarkers. The preoperative TB and DB in the PJI group were 10.84 ± 0.61 μmol/L and 3.07 ± 0.19 μmol/L, respectively, which were lower than those in the non-PJI group (14.68 ± 0.75 μmol/L and 4.70 ± 0.39 μmol/L, P < 0.001). The area under the curve (AUC) of preoperative TB to predict PJI was 0.755 (P < 0.001, cutoff = 11.55 μmol/L, sensitivity = 66.67%, specificity = 75.76%). Meanwhile, the AUC of preoperative DB was 0.760 (P < 0.001, cutoff = 4.00 μmol/L, sensitivity = 84.62%, specificity = 54.45%). Conclusions The serum levels of TB and DB before the primary arthroplasty were lower in PJI patients than in non-PJI patients, and the preoperative values lower than 11.55 μmol/L and 4.00 μmol/L could be considered as a risk factor for postoperative PJI.

scholarly journals Predicting chromosome damage in astronauts participating in international space station missions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alan Feiveson ◽  
Kerry George ◽  
Mark Shavers ◽  
Maria Moreno-Villanueva ◽  
Ye Zhang ◽  
...  
Keyword(s):  
International Space Station ◽  
Dose Response ◽  
Ex Vivo ◽  
Space Station ◽  
Space Radiation ◽  
Blood Samples ◽  
International Space ◽  
Significant Difference ◽  
Subject Specific

AbstractSpace radiation consists of energetic protons and other heavier ions. During the International Space Station program, chromosome aberrations in lymphocytes of astronauts have been analyzed to estimate received biological doses of space radiation. More specifically, pre-flight blood samples were exposed ex vivo to varying doses of gamma rays, while post-flight blood samples were collected shortly and several months after landing. Here, in a study of 43 crew-missions, we investigated whether individual radiosensitivity, as determined by the ex vivo dose–response of the pre-flight chromosome aberration rate (CAR), contributes to the prediction of the post-flight CAR incurred from the radiation exposure during missions. Random-effects Poisson regression was used to estimate subject-specific radiosensitivities from the preflight dose–response data, which were in turn used to predict post-flight CAR and subject-specific relative biological effectiveness (RBEs) between space radiation and gamma radiation. Covariates age, gender were also considered. Results indicate that there is predictive value in background CAR as well as radiosensitivity determined preflight for explaining individual differences in post-flight CAR over and above that which could be explained by BFO dose alone. The in vivo RBE for space radiation was estimated to be approximately 3 relative to the ex vivo dose response to gamma irradiation. In addition, pre-flight radiosensitivity tended to be higher for individuals having a higher background CAR, suggesting that individuals with greater radiosensitivity can be more sensitive to other environmental stressors encountered in daily life. We also noted that both background CAR and radiosensitivity tend to increase with age, although both are highly variable. Finally, we observed no significant difference between the observed CAR shortly after mission and at > 6 months post-mission.

scholarly journals The change of coagulation profile in two-staged arthroplasty for periprosthetic joint infection patients: a retrospective cohort study

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Hao Li ◽  
Rui Li ◽  
L. L. Li ◽  
Wei Chai ◽  
Chi Xu ◽  
...  
Keyword(s):  
Cohort Study ◽  
Periprosthetic Joint Infection ◽  
Retrospective Cohort Study ◽  
Persistent Infection ◽  
Retrospective Cohort ◽  
Joint Infection ◽  
Diagnostic Study ◽  
Level Of Evidence ◽  
Coagulation Profile ◽  
Significant Difference

Abstract Aims Periprosthetic joint infection (PJI) is a serious complication of total joint arthroplasty. We performed a retrospective cohort study to evaluate (1) the change of coagulation profile in two-staged arthroplasty patients and (2) the relationship between coagulation profile and the outcomes of reimplantation. Method Between January 2011 and December 2018, a total of 202 PJI patients who were operated on with two-staged arthroplasty were included in this study initially. This study continued for 2 years and the corresponding medical records were scrutinized to establish the diagnosis of PJI based on the 2014 MSIS criteria. The coagulation profile was recorded at two designed points, (1) preresection and (2) preimplantation. The difference of coagulation profile between preresection and preimplantation was evaluated. Receiver operating characteristic curves (ROC) were used to evaluate the diagnostic efficiency of the coagulation profile and change of coagulation profile for predicting persistent infection before reimplantation. Results The levels of APTT, INR, platelet count, PT, TT, and plasma fibrinogen before spacer implantation were significantly higher than before reimplantation. No significant difference was detected in the levels of D-dimer, ACT, and AT3 between the two groups. The AUC of the combined coagulation profile and the change of combined coagulation profile for predicting persistent infection before reimplantation was 0.667 (95% CI 0.511, 0.823) and 0.667 (95% CI 0.526, 0.808), respectively. Conclusion The coagulation profile before preresection is different from before preimplantation in two-staged arthroplasty and the coagulation markers may play a role in predicting infection eradication before reimplantation when two-stage arthroplasty is performed. Level of evidence Level III, diagnostic study.

scholarly journals A Tumbling Magnetic Microrobot System for Biomedical Applications

Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 861
Author(s):  
Elizabeth E. Niedert ◽  
Chenghao Bi ◽  
Georges Adam ◽  
Elly Lambert ◽  
Luis Solorio ◽  
...  
Keyword(s):  
Ultrasound Imaging ◽  
Biomedical Applications ◽  
Imaging System ◽  
Ex Vivo ◽  
Negative Control ◽  
Circular Path ◽  
Rotational Axis ◽  
Significant Difference

A microrobot system comprising an untethered tumbling magnetic microrobot, a two-degree-of-freedom rotating permanent magnet, and an ultrasound imaging system has been developed for in vitro and in vivo biomedical applications. The microrobot tumbles end-over-end in a net forward motion due to applied magnetic torque from the rotating magnet. By turning the rotational axis of the magnet, two-dimensional directional control is possible and the microrobot was steered along various trajectories, including a circular path and P-shaped path. The microrobot is capable of moving over the unstructured terrain within a murine colon in in vitro, in situ, and in vivo conditions, as well as a porcine colon in ex vivo conditions. High-frequency ultrasound imaging allows for real-time determination of the microrobot’s position while it is optically occluded by animal tissue. When coated with a fluorescein payload, the microrobot was shown to release the majority of the payload over a 1-h time period in phosphate-buffered saline. Cytotoxicity tests demonstrated that the microrobot’s constituent materials, SU-8 and polydimethylsiloxane (PDMS), did not show a statistically significant difference in toxicity to murine fibroblasts from the negative control, even when the materials were doped with magnetic neodymium microparticles. The microrobot system’s capabilities make it promising for targeted drug delivery and other in vivo biomedical applications.

The Change of Coagulation Profile in Two-staged Arthroplasty for Periprosthetic Joint Infection Patients：A Retrospective Cohort Study

2021 ◽  
Author(s):  
Hao Li ◽  
Rui Li ◽  
Liangliang Li ◽  
Chi Xu ◽  
Wei Chai ◽  
...  
Keyword(s):  
Cohort Study ◽  
Periprosthetic Joint Infection ◽  
Retrospective Cohort Study ◽  
Persistent Infection ◽  
Retrospective Cohort ◽  
Joint Infection ◽  
Diagnostic Study ◽  
Level Of Evidence ◽  
Coagulation Profile ◽  
Significant Difference

Abstract Aims：Periprosthetic joint infection (PJI) a serious complication of total joint arthroplasty. We performed a retrospective cohort study to evaluate 1) the change of coagulation profile in two-staged arthroplasty patients 2) the relationship between coagulation profile and the outcomes of reimplantation. Method: Between 2011 January and 2018 December, a total of 202 PJI patients who were performed with two-staged arthroplasty were included in this study initially. They were followed up at least 2 years and corresponding medical records were scrutinized to establish the diagnosis of PJI based on the 2014 MSIS criteria. The coagulation profile was recorded at two designed points 1) preresection and 2) preimplantation. Then, the difference of coagulation profile between preresection and preimplantation was evaluated. Besides, receiver operating characteristic curves (ROC) were used to evaluate the diagnostic efficiency of coagulation profile and the change of coagulation profile for predicting persistent infection before reimplantation. Results: The levels of APTT, INR, platelet count, PT, TT and plasma fibrinogen before spacer implantation were significantly higher than that before reimplantation. No significant difference was detected in the levels of D-dimer, ACT, AT3 between the two groups. The AUC of the combined coagulation profile and the change of combined coagulation profile for predicting persistent infection before reimplantation was 0.667 (95%CI:(0.511,0.823) and 0.667 (95%CI: (0.526,0.808)), respectively.Conclusion: The coagulation profile before preresection is different from that before preimplantation in two-staged arthroplasty and the coagulation markers may play a role in predicting infection eradication before reimplantation when two-stage arthroplasty is performed. Level of Evidence: level III, diagnostic study

scholarly journals Qualitative Alpha-defensin Versus The Main Available Tests For The Diagnosis Of Periprosthetic Joint Infection: Best Predictor Test?

2018 ◽  
Vol 3 (3) ◽  
pp. 156-164 ◽  
Author(s):  
Giovanni Riccio ◽  
Luca Cavagnaro ◽  
Wassim Akkouche ◽  
Giuliana Carrega ◽  
Lamberto Felli ◽  
...  
Keyword(s):  
Likelihood Ratio ◽  
Periprosthetic Joint Infection ◽  
Joint Infection ◽  
Positive Likelihood Ratio ◽  
Negative Likelihood Ratio ◽  
Diagnostic Methods ◽  
Minimal Amount ◽  
Musculoskeletal Infection ◽  
Infection Diagnosis ◽  
Significant Difference

Abstract. Introduction: Biomarkers such as α-defensin demonstrated to be a potentially useful option in periprosthetic joint infection (PJI) diagnosis. Recently, a new point-of-care test for α-defensin level detection in synovial fluid has been commercialized in Europe. The aim of this study is to compare the α-defensin test (SynovasureTM) diagnostic ability with the main available clinical tests for periprosthetic joint infection diagnosis in a practical clinical setting of a Bone Infection Unit.Methods: Between 2015 and 2017, 146 patients with suspected chronic PJI were screened with SynovasureTM. Seventy-three of these met the Musculoskeletal Infection Society (MSIS) criteria and were included in the analysis. According to MSIS criteria, 40 patients (54.7%) were classified as infected and 33 (45.3%) as not infected. The results obtained with SynovasureTM were recorded and compared with standard diagnostic methods for PJI diagnosis.Results: SynovasureTM showed a sensitivity of 85.0 % (95% CI 70.2 to 94.3) and a specificity of 96.9 % (95% CI 83.8 to 99.9) for PJI detection. The positive likelihood ratio of SynovasureTM was 27.2 (95% CI 3.9 to 188.1) and the negative likelihood ratio was 0.2 (95% CI 0.1 to 0.3). The diagnostic odds ratio was 181.3 (95% CI 20.7 to 1590.4). SynovasureTM demonstrated a statistical significant difference when compared to Erythrocyte Sedimentation Rate (ESR) and C-reactive Protein (CRP) specificity (at least one positive test) and preoperative culture sensitivity (1 positive culture).Conclusion: Our findings show that SynovasureTM sensitivity is lower than quantitative α-D test, but when compared to the main available tests shows a good specificity and the highest DOR. On the SF it is the easier test to do, due to the fact that it needs a minimal amount of SF and it is not limited by blood contamination or antibiotic use. Whereas there is no single standalone test, SynovasureTM should be considered a reliable additional test for periprosthetic joint infection diagnosis in everyday clinical practice.

scholarly journals Ex vivo and in vivo study of Kowa HA-2 applanation tonometer in the measurement of intraocular pressure in cats

2017 ◽  
Vol 38 (6) ◽  
pp. 3647
Author(s):  
Claudia Lizandra Ricci ◽  
Rogério Giuffrida ◽  
Glaucia Prada Kanashiro ◽  
Hilidia Stephania Rufino Belezzi ◽  
Carolina De Carvalho Bacarin ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Ex Vivo ◽  
Clinical Signs ◽  
In Vivo Study ◽  
Eye Drops ◽  
Significant Difference ◽  
Applanation Tonometer ◽  
Ex Vivo Study ◽  
Healthy Eyes

The objective of this study was to evaluate the use of the Kowa HA-2 applanation tonometer in measuring intraocular pressure (IOP) in cats. Ten healthy eyes were used in an ex vivo study in which the calibration curve for manometry vs. tonometry was determined by artificially raising the IOP in 5 mmHg increments up to 60 mmHg (10-60 mmHg). Both eyes of 10 anesthetized cats were studiedin vivo to compare manometry vs. tonometry. In the ambulatory study, 78 healthy eyes, 7 eyes with glaucoma and 20 eyes with uveitis were evaluated by tonometry, which was performed with topical anesthesia and 1% fluorescein eye drops for the formation of fluorescein semicircles. The correlation coefficient (r²) between the manometer and the Kowa HA-2 tonometer was 0.993 and the linear regression equation was y = 0.0915x + 0.0878 in the ex-vivo study. In the in vivo study, the IOP values (mean±SD, in mmHg) in manometry were 15.6 ± 1.1(14.0 – 17.5) and in tonometry were 15.5 ± 1.2(13.5 – 17.2), with no significant difference (P > 0.05) between manometry and tonometry. In ambulatory study, using the Kowa HA-2 tonometer, the IOP values (mean±SD, in mmHg) were 15.0 ± 1.5 (11.8 – 18.3) for the healthy eyes, 38.4 ± 8.1(29.6 – 53.7) for glaucomatous eyes and 10.4 ± 2.0(5.3 – 12.2) for eyes with uveitis. There was a strong correlation and accuracy between the IOP values with the manometry and the Kowa HA-2 tonometer. In the ambulatorystudy the IOP values obtained with the tonometer were compatible for animals with healthy eyes and with clinical signs of glaucoma and uveitis. We conclude that the Kowa HA-2 tonometer can be used in the measurement of IOP in cats, since it is a practical and accurate method in this species.

scholarly journals Effect of Doxycycline on Survival in Abdominal Aortic Aneurysms in a Mouse Model

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Lisa C. Adams ◽  
Julia Brangsch ◽  
Jan O. Kaufmann ◽  
Dilyana B. Mangarova ◽  
Jana Moeckel ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Ex Vivo ◽  
Endothelial Damage ◽  
Aortic Aneurysms ◽  
Clinical Dose ◽  
Doxycycline Treatment ◽  
Abdominal Aortic ◽  
Significant Difference ◽  
Aneurysm Growth

Background. Currently, there is no reliable nonsurgical treatment for abdominal aortic aneurysm (AAA). This study, therefore, investigates if doxycycline reduces AAA growth and the number of rupture-related deaths in a murine ApoE−/− model of AAA and whether gadofosveset trisodium-based MRI differs between animals with and without doxycycline treatment. Methods. Nine ApoE−/− mice were implanted with osmotic minipumps continuously releasing angiotensin II and treated with doxycycline (30 mg/kg/d) in parallel. After four weeks, MRI was performed at 3T with a clinical dose of the albumin-binding probe gadofosveset (0.03 mmol/kg). Results were compared with previously published wild-type control animals and with previously studied ApoE−/− animals without doxycycline treatment. Differences in mortality were also investigated between these groups. Results. In a previous study, we found that approximately 25% of angiotensin II-infused ApoE−/− mice died, whereas in the present study, only one out of 9 angiotensin II-infused and doxycycline-treated ApoE−/− mice (11.1%) died within 4 weeks. Furthermore, doxycycline-treated ApoE−/− mice showed significantly lower contrast-to-noise (CNR) values ( p = 0.017 ) in MRI compared to ApoE−/− mice without doxycycline treatment. In vivo measurements of relative signal enhancement (CNR) correlated significantly with ex vivo measurements of albumin staining (R2 = 0.58). In addition, a strong visual colocalization of albumin-positive areas in the fluorescence albumin staining with gadolinium distribution in LA-ICP-MS was shown. However, no significant difference in aneurysm size was observed after doxycycline treatment. Conclusion. The present experimental in vivo study suggests that doxycycline treatment may reduce rupture-related deaths in AAA by slowing endothelial damage without reversing aneurysm growth.

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