Differences in platelet-rich plasma composition influence bone healing

AIM

Platelet-rich plasma (PRP) is an autologous blood-derived material that has been used to enhance bone regeneration. Clinical studies, however, reported inconsistent outcomes. This study aimed to assess the effect of changes in leucocyte and PRP (L-PRP) composition on bone defect healing.

MATERIALS AND METHODS

L-PRPs were prepared using different centrifugation methods and their regenerative potential was assessed in an in-vivo rat model. Bilateral critical-size tibial bone defects were created and filled with single-spin L-PRP, double-spin L-PRP, or filtered L-PRP. Empty defects and defects treated with collagen scaffolds served as controls. Rats were euthanized after 2 weeks, and their tibias were collected and analysed using micro-CT and histology.

RESULTS

Double-spin L-PRP contained higher concentrations of platelets than single-spin L-PRP and filtered L-PRP. Filtration of single-spin L-PRP resulted in lower concentrations of minerals and metabolites. In vivo, double-spin L-PRP improved bone healing by significantly reducing the size of bone defects (1.08 ± 0.2 mm³ ) compared to single-spin L-PRP (1.42 ± 0.27 mm³ ) or filtered L-PRP (1.38 ± 0.28 mm³ ). There were fewer mast cells, lymphocytes, and macrophages in defects treated with double-spin L-PRP than in those treated with single-spin or filtered L-PRP.

CONCLUSION

The preparation method of L-PRP affects their composition and potential to regenerate bone.

Accuracy of digital planning in zygomatic implants

Background

Zygomatic implants have been described as a therapeutic alternative for patients with severe maxillary atrophy in order to avoid bone augmentation procedures. Taking that into account, in these treatments, the key factor is the position of the implant, the virtual surgical planning (VSP) is widespread among most clinicians before surgery on the patient. However, there are no studies which evaluate the clinical relevance of these VSP.

The aim of this study is to determine whether digital planning on zygomatic implants has any influence on the implant dimensions and position, even when performing conventional surgery afterwards.

Results

Fourteen zygomatic implants were placed in four patients. Pre-operative and post-operative helicoidal computed tomography were performed to each patient to allow the comparison between the digital planning and the final position of implants. Tridimensional deviation (TD), mesio-distal deviation (MDD), bucco-palatine deviation (BPD), and apico-coronal deviation (ACD) were evaluated as well as angular deviation (AD). Significative differences in apical TD were observed with a mean of 6.114 ± 4.28 mm (p < 0.05). Regarding implant position, only implants placed in the area of the first right molar reported significant differences (p < 0.05) for ACD. Also, implant length larger than 45 mm showed BPD significative differences (p < 0.05).

Conclusions

Zygomatic implant surgery is a complex surgical procedure, and although VSP is a useful tool which helps the clinician determine the number and the length of zygomatic implants as well as its proper position, surgical experience is still mandatory.

A5 GM-CSF AUTOANTIBODIES: PREDICTORS OF CROHN’S DISEASE DEVELOPMENT AND A NOVEL THERAPEUTIC APPROACH

Background

Crohn’s disease (CD) is a heterogenous, chronic inflammatory disorder driven by a combination of genetic, environmental, and microbiota-dependent risk factors. Mononuclear phagocytes (MNP) are crucial cells that maintain intestinal homeostasis. An important cytokine for MNP survival and function is granulocyte-macrophage colony stimulating factor (GM-CSF). Interestingly, several studies reported CD-associated genetic risk variants within the GM-CSF receptor and its downstream signaling components. Furthermore, high titers of autoantibodies specific to GM-CSF can be detected in CD patients. Taken together, this data suggests an important role for GM-CSF in abrogation of CD development in a subgroup of patients.

Aims

This study sought to investigate the function of GM-CSF autoantibodies in CD.

Methods

We retrospectively quantified and characterized GM-CSF autoantibodies in sera of 220 CD, 200 ulcerative colitis (UC) patients, and 220 healthy controls (HC) sampled at 3 time points prior to disease diagnosis and one time point after diagnosis. ELISA was used to determine GM-CSF autoantibody titers and isotypes followed by in vitro multiplexed mass cytometry (CyTOF) neutralization assays on peripheral blood mononuclear cells. Flow cytometry and CyTOF were used to map the profile of immune cells isolated from inflamed and non-inflamed CD mucosa.

Results

Our data demonstrates that GM-CSF autoantibodies are specific to CD, significantly elevated up to 7 years prior to diagnosis of disease, and correlate with disease location, severity, and complications at the time of diagnosis. Moreover, in contrast to GM-CSF autoantibodies in pulmonary alveolar proteinosis patients, CD-associated autoantibodies neutralize GM-CSF via specific recognition of post-translational modifications (PTM), affecting MNP function. Removal of PTM enabled GM-CSF to escape autoantibody binding and restored MNP response to GM-CSF in the presence of neutralizing antibodies, indicating a potential therapeutic avenue. Furthermore, we identified group 3 innate lymphoid cells (ILC3) as a major source of GM-CSF in the healthy intestinal tract, suggesting intriguing crosstalk of MNP and ILC3 across the GM-CSF-GM-CSFR axis.

Conclusions

Our results identify GM-CSF autoantibodies as predictive serological biomarker for CD in a subgroup of patients presenting with severe and complicated form of disease at the time of diagnosis. The presence of GM-CSF autoantibodies precedes the onset of CD by several years and likely abrogates homeostatic immune cell crosstalk involving ILC3 and MNP, suggesting the development of a pre-diseased state in CD patients.

Funding Agencies

CIHRDr. Edward Ketchum Graduate Scholarship

Application of propolis extract, nanovitamin C and nanovitamin E to prevent alveolar osteitis after impacted lower third molar surgery. A randomized, double-blind, split-mouth, pilot study

BACKGROUND

Propolis has anti-inflammatory, analgesic and healing properties. The purpose of this study was to determine whether a gel containing 2% of propolis extract, 0.2% of ascorbic acid and 0.2% of tocopherol acetate is effective in preventing surgical complications related to impacted lower third molar extractions.

MATERIAL AND METHODS

A randomized, double-blind, split-mouth study was performed. Fifteen patients were recruited who needed bilateral impacted lower third molar extractions with a similar surgical difficulty. A test or placebo gel was administered randomly inside post-extraction sockets. Each patient was instructed to apply the gel 3 times/day in the surgical wound for a week. After a month, the contralateral third molar was extracted, and the opposite gel applied. The following parameters were diagnosed/evaluated and then recorded: alveolar osteitis following Blum's criteria, swelling and trismus at day one, two, three and seven post-intervention, wound healing at day 7 post-intervention, and postoperative pain using a visual analog scale, as well as, the number of analgesic pill intake.

RESULTS

A total of twenty-six surgical procedures were performed in 13 patients (mean age 20.67±2 years). Alveolar osteitis was reported in 3 patients from the placebo group (23.1%) and none in the test group (0%) (p=0.25). No statistically significant differences were reported in swelling, trismus, wound healing or analgesic pill consumption between two groups. But statistically lower postoperative pain during the 7 days after surgical extractions was found according to visual analog scale in test group compared to the placebo group (p=0.007). No side effects were reported.

CONCLUSIONS

The application of this gel may be effective in preventing alveolitis and thus reducing postoperative pain after impacted third molar extractions. More randomized clinical trials with larger sample are needed to confirm these results.

Diploma on Ultrasound training and competency for Intensive Care and Emergency Medicine: Consensus document of the Spanish Society of Anesthesia (SEDAR), Spanish Society of Internal Medicine (SEMI) and Spanish Society of Emergency Medicine (SEMES)

The use of ultrasound as a clinical diagnostic tool and guide of bedside procedures has become an indispensable examination in the acute critically ill patient. The training of professionals in minimum skills of knowledge, management and indications of use of ultrasound required to be defined by the Scientific Societies. The Intensive Care Ultrasound Working Group of the Spanish Society of Anesthesiology and Resuscitation (SEDAR), of the Spanish Society of Internal Medicine (SEMI) and the Spanish Society of Emergency Medicine (SEMES) has developed this consensus document in which the recommended training program and the minimum competencies to be achieved with regard to the use of Ultrasound in Intensive Care, Anesthesia and Emergency medicine are defined. This document defines the training program and the skills to acquire in order to achieve the diploma in lung, abdominal and vascular ultrasound. This document can serve as a guide to define the skills to be acquired in the training programs of residents (MIRs) of specialists working in intensive care, anesthesia, and emergency medicine.

The Mars Environmental Dynamics Analyzer, MEDA. A Suite of Environmental Sensors for the Mars 2020 Mission

NASA's Mars 2020 (M2020) rover mission includes a suite of sensors to monitor current environmental conditions near the surface of Mars and to constrain bulk aerosol properties from changes in atmospheric radiation at the surface. The Mars Environmental Dynamics Analyzer (MEDA) consists of a set of meteorological sensors including wind sensor, a barometer, a relative humidity sensor, a set of 5 thermocouples to measure atmospheric temperature at ∼1.5 m and ∼0.5 m above the surface, a set of thermopiles to characterize the thermal IR brightness temperatures of the surface and the lower atmosphere. MEDA adds a radiation and dust sensor to monitor the optical atmospheric properties that can be used to infer bulk aerosol physical properties such as particle size distribution, non-sphericity, and concentration. The MEDA package and its scientific purpose are described in this document as well as how it responded to the calibration tests and how it helps prepare for the human exploration of Mars. A comparison is also presented to previous environmental monitoring payloads landed on Mars on the Viking, Pathfinder, Phoenix, MSL, and InSight spacecraft.

Relation of contrast volume to new onset atrial fibrillation in acute coronary syndrome underwent percutaneous coronary intervention

Introduction

There is an important relationship between atrial fibrillation (AF) and contrast induced nephropathy (CIN). Several hypotheses were suggested to explain this unidirectional association between CIN and AF, like influence on renin-angiotensin-aldosterone system and the inflammatory pathway, as well as the use of iodinated contrasts -due to its possible interaction at the thyroid hormone regulation-.

Purpose

The aim of this study was to analyze the relation between contrast volume and the subsequent development of AF in patients with acute coronary syndrome (ACS)

Methods

A total of 6,133 ACS patients underwent PCI between 2010 and 2016 were analyzed. We have excluded 1,896 patients with prior history of AF, without data about contrast volume or with missing data about follow-up. The impact of contrast volume in the development of AF was assessed by Cox regression analysis. Hazard Ratios (HR) with 95% of confidence interval (CI) were reported. Maximum allowable contrast dose (MACD) was defined as 5*body weight/serum creatinine.

Results

From the total study population (4,237 patients, 64.3±12.8 years, 24.2% women), 399 (9.4%) developed AF during a mean follow-up of 3.5±2.4 years. Mean contrast volume used was 199.9±90.3 ml. Contrast volume was not associated with follow-up de novo AF (HR 0.99, 95% CI: 0.99–1.00; p=0.834). However, the ratio between contrast volume used and the maximum allowable contrast dose (CV/MACD) resulted a predictor of follow-up AF (HR 1.18, 95% CI: 1.02–1.37, p=0.027). The cumulative incidence of AF was 2.7 per 100 patients/year in patients with CV/MACD ≤1 and 4.8 per 100 patients/year in patients with CV/MACD &gt;1. After adjusting for those variables associated with follow-up AF in the univariate analysis, the use of a contrast volume higher than MACD resulted an independent predictor of AF (HR 1.40, 95% CI: 1.03–1.89; p=0.032).

Conclusion

Doses of contrast volume higher than the maximum allowable contrast dose were independently associated with higher rates of AF during the follow-up.

Cumulative incidence of AF by groups

Funding Acknowledgement

Type of funding source: None

Palatal root surgery of a maxillary molar using a piezosurgery transantral approach with simultaneous sinus lift grafting: a case report

AIM

To report a case involving transantral palatal root piezoelectric surgery followed by a sinus floor augmentation procedure with the purpose of minimizing and managing complications associated with sinus lining perforations and optimizing bone regeneration at the site of the surgical defect.

SUMMARY

An asymptomatic 28-year-old male patient with the diagnosis of chronic apical periodontitis on a previously root filled right maxillary first molar (FDI tooth 16) and second premolar (No. 15) was managed by transantral apical surgery. Cone-beam computerized tomography (CBCT) revealed the position of the palatal root of the first molar within the maxillary sinus. The case highlights the management of the palatal root and the handling of a perforation of the Schneiderian membrane through a combination of piezosurgery and a sinus lift grafting procedure involving a second-generation of platelet concentrates. No postoperative complications were observed. Sinus bone augmentation after a 26-month recall period was confirmed by CBCT in the clinically asymptomatic teeth.

KEY LEARNING POINTS

The selective bone tissue cutting and enhanced visibility obtained by piezoelectric surgery in comparison with current rotary techniques make this technology the preferred tool for apical surgery when the mucosal lining of the maxillary sinus could be compromised. The wound healing and physical properties of the platelet-rich fibrin membranes in combination with an allograft material can be considered as sinus bone graft options when a transantral approach is performed on a palatal root of a maxillary molar. A preoperative tomographic examination is essential for apical surgery using a transantral approach with sinus bone augmentation, because of the information obtained from the axial and coronal views on the CBCT scan.

Location and Setting of the Mars InSight Lander, Instruments, and Landing Site

Knowing precisely where a spacecraft lands on Mars is important for understanding the regional and local context, setting, and the offset between the inertial and cartographic frames. For the InSight spacecraft, the payload of geophysical and environmental sensors also particularly benefits from knowing exactly where the instruments are located. A ~30 cm/pixel image acquired from orbit after landing clearly resolves the lander and the large circular solar panels. This image was carefully georeferenced to a hierarchically generated and coregistered set of decreasing resolution orthoimages and digital elevation models to the established positive east, planetocentric coordinate system. The lander is located at 4.502384°N, 135.623447°E at an elevation of -2,613.426 m with respect to the geoid in Elysium Planitia. Instrument locations (and the magnetometer orientation) are derived by transforming from Instrument Deployment Arm, spacecraft mechanical, and site frames into the cartographic frame. A viewshed created from 1.5 m above the lander and the high-resolution orbital digital elevation model shows the lander is on a shallow regional slope down to the east that reveals crater rims on the east horizon ~400 m and 2.4 km away. A slope up to the north limits the horizon to about 50 m away where three rocks and an eolian bedform are visible on the rim of a degraded crater rim. Azimuths to rocks and craters identified in both surface panoramas and high-resolution orbital images reveal that north in the site frame and the cartographic frame are the same (within 1°).

Heath care utilization after birth in Brazil: a national study

Background

The Brazilian Ministry of Health recommends primary health care actions for women and babies in the first week after birth, with the aim of monitoring health status, screening for diseases, vaccination, support for breastfeeding and promoting contraception. However, data on these actions are not available at the national level. This study aims to estimate the use of outpatient health services in the postpartum period and to verify the demographic, socioeconomic and obstetric factors associated with this use.

Methods

National hospital-based study, conducted in 2011-2012, with an interview of 23,894 women. Estimates were calculated for eight indicators of health service use with performance assessed as “satisfactory” (75-100%), “partial” (50-74%) and “unsatisfactory” (&lt;50%). Multiple logistic regression was performed to verify the association between women's characteristics and each of the analyzed indicators.

Results

”Demand for postpartum consultation” (73.9%; 95% CI: 72.4-75.3%), “demand for newborn consultation” (91.6%; 95% CI: 90.6% - 92.5%), “BCG vaccination” (99.0%; 95% CI 98.7% - 99.2%) and “Hepatitis B vaccination” (96.8%; 95% CI 96.0%-97.5%) were considered satisfactory. “Neonatal screening test in the first week of life” was considered partial (60.1%; 95% CI 57.6% - 62.6%), while “consultation of the woman in the first 15 days after delivery” (37.0% 95% CI 35.0-39.0%),”consultation of the newborn in the first seven days of life”(21.8% 95% CI 20.2% - 23.5%) and “receiving the result of neonatal screening in the first month of life” (29.8% CI 95% 27.6%-32.2%) were considered unsatisfactory. Regional and social inequalities were identified, with the worst performance of all indicators in the less developed North and Northeast regions and in the most vulnerable women.

Conclusions

There is a need for better organization and provision of services, aiming to increase the coverage of postpartum and childcare actions and to reduce health inequalities.

Key messages

Low coverage of postnatal actions limits access to effective health care practices, putting mothers and babies at greater risk of illness and death. Regional and social inequalities and worse performance of health actions that depend exclusively on primary care services suggest barriers to access and failures in the organization of services.

Cerebral Venous Thrombosis Associated with COVID-19

Despite the severity of coronavirus disease 2019 (COVID-19) being more frequently related to acute respiratory distress syndrome and acute cardiac and renal injuries, thromboembolic events have been increasingly reported. We report a unique series of young patients with COVID-19 presenting with cerebral venous system thrombosis. Three patients younger than 41 years of age with confirmed Severe Acute Respiratory Syndrome coronavirus 2 (SARS-Cov-2) infection had neurologic findings related to cerebral venous thrombosis. They were admitted during the short period of 10 days between March and April 2020 and were managed in an academic institution in a large city. One patient had thrombosis in both the superficial and deep systems; another had involvement of the straight sinus, vein of Galen, and internal cerebral veins; and a third patient had thrombosis of the deep medullary veins. Two patients presented with hemorrhagic venous infarcts. The median time from COVID-19 symptoms to a thrombotic event was 7 days (range, 2-7 days). One patient was diagnosed with new-onset diabetic ketoacidosis, and another one used oral contraceptive pills. Two patients were managed with both hydroxychloroquine and azithromycin; one was treated with lopinavir-ritonavir. All patients had a fatal outcome. Severe and potentially fatal deep cerebral thrombosis may complicate the initial clinical presentation of COVID-19. We urge awareness of this atypical manifestation.

Characterization of non-linear mechanical behavior of the cornea

The objective of this study was to evaluate which hyperelastic model could best describe the non-linear mechanical behavior of the cornea, in order to characterize the capability of the non-linear model parameters to discriminate structural changes in a damaged cornea. Porcine corneas were used, establishing two different groups: control (non-treated) and NaOH-treated (damaged) corneas (n = 8). NaOH causes a chemical burn to the corneal tissue, simulating a disease associated to structural damage of the stromal layer. Quasi-static uniaxial tensile tests were performed in nasal-temporal direction immediately after preparing corneal strips from the two groups. Three non-linear hyperelastic models (i.e. Hamilton-Zabolotskaya model, Ogden model and Mooney-Rivlin model) were fitted to the stress–strain curves obtained in the tensile tests and statistically compared. The corneas from the two groups showed a non-linear mechanical behavior that was best described by the Hamilton-Zabolotskaya model, obtaining the highest coefficient of determination (R² > 0.95). Moreover, Hamilton-Zabolotskaya model showed the highest discriminative capability of the non-linear model parameter (Parameter A) for the tissue structural changes between the two sample groups (p = 0.0005). The present work determines the best hyperelastic model with the highest discriminative capability in description of the non-linear mechanical behavior of the cornea.

Anterior shoulder anatomy and subcoracoid impingement: An anatomical study

OBJECTIVE

The aim of our study was to describe the anatomy of the anterior shoulder, specifically structures potentially involved in subscapularis tears pathophysiology and also to identify structures at risk during surgical approaches of this area.

MATERIALS AND METHODS

We designed an observational, experimental study based on cadaveric models. Dissection was performed and several structures of the anterior shoulder were characterized including the subscapularis, coracoid morphology, the coracoacromial ligament, coraco-humeral distance, and the axillary and musculocutaneous nerves.

RESULTS

Our sample included 16 shoulders. The coracoacromial ligament presented two bands in 37.5%, and these variants were significantly wider and thinner, and were associated with inferior coraco-humeral distance in internal rotation. The subscapularis footprint was longer and the coracoid process was bigger in male specimens, and the median coracoid angle was 122°, corresponding to a Leite-Torres type I. The Subscapularis showed a median thickness of 0.7cm, while the coraco-humeral distance in our sample ranged from 0.30cm in internal rotation to 0.85cm in external rotation. Neurologic relevant structures were at least more than 2.55cm from the coracoid tip.

CONCLUSIONS

This is the first paper to explore the eventual relationship between the presence of a double band coracoacromial ligament variant and subcoracoid impingement. Also, to our knowledge, this is the first cadaveric model study to postulate a possible anatomic base for subcoracoid impingement, as the SS myotendinous junction thickness was found to be greater than the coraco-humeral distance in neutral position and in IR.

Observation of Radar Echoes from High-Energy Particle Cascades

We report the observation of radar echoes from the ionization trails of high-energy particle cascades. Data were taken at the SLAC National Accelerator Laboratory, where the full electron beam (∼10^{9}  e^{-} at ∼10  GeV/e^{-}) was directed into a plastic target to simulate an ultrahigh-energy neutrino interaction. The target was interrogated with radio waves, and coherent radio reflections from the cascades were detected with properties consistent with theoretical expectations. This is the first definitive observation of radar echoes from high-energy particle cascades, which may lead to a viable neutrino detection technology for energies ≳10^{16}  eV.