Optimization of ovine bone decalcification for increased cellular detail: a parametric study

There are many published methods of decalcifying bone for paraffin histology; however, the current literature lacks details regarding the processing of ovine tissue. Ovine bone tissue presents challenges, as samples are often denser and larger than other comparative animal models, thus increasing decalcification times. Trifluoroacetic Acid (TFAA) has previously been used to decalcify ovine bone samples for histological analysis. Unfortunately, TFAA is a strong acid and often results in loss of cellular detail, especially in the connected soft tissue. This is generally manifested as over staining with eosin, and a decrease in cellular features which impacts overall histological interpretation. It is well known that leaving tissue in acid for long periods degrades cellular detail; therefore, minimizing decalcification time is critical to accurately determine cellular morphology. Six decalcification solutions (8% TFAA, 20% TFAA, 8% formic acid, 20% formic acid, Formical-4, and XLCal, and three temperatures (room temperature, 30°C, 37°C), were examined to determine their effects on cellular detail in ovine vertebrae and humeral heads. These data clearly indicate that 20% formic acid at 30°C yielded better decalcification rates (2.6 d ± 0.9 d) and cellular detail (none to mild changes) for the vertebrae samples, and 20% formic acid at RT yielded the best cellular detail (none to minimal loss) for humerus samples with a moderate amount of time (6.5 d ± 1.7). These results should establish the optimal demineralization procedures for ovine bone used in scientific studies resulting in improved cellular detail while minimizing decalcification times.

Trait mindfulness and the mental and physical health of caregivers for individuals with cancer

BACKGROUND

Mindfulness plays a role in moderating the negative mental and physical health outcomes associated with caregiving. The aims of this study were to examine the relationship between trait mindfulness and the (1) psychological functioning, (2) health behaviors, (3) and physical health of caregivers for individuals diagnosed with cancer.

METHODS

Caregivers completed a battery of questionnaires and examinations assessing sociodemographic characteristics, trait mindfulness, depression, perceived stress, caregiver stress, sleep, diet, physical activity, tobacco use, alcohol use, blood pressure, and BMI. Demographics and cancer diagnostics were collected for the individuals whom caregivers supported. Linear regression, multivariate analyses, and moderator analyses were performed.

RESULTS

Of the 78 caregivers, the mean age was 63.9 (S.D.=13.1); 59% identified as female; 97% identified as White. Regression analyses indicated that caregivers who reported higher levels of trait mindfulness reported significantly less perceived stress (b= -4.38, SE= 0.88, p <.001), lower levels of depression (b= -3.74, SE= 1.10, p = .001), greater caregiver quality of life (b= -9.05, SE=2.12, p < .001), better sleep quality (b= -0.98, SE=0.44, p = 0.03), and lower rates of tobacco use (b= -10.12, SE= 3.43, p =.003). Trait mindfulness was not significantly related to diet, alcohol use, blood pressure, or BMI.

CONCLUSIONS

Higher levels of trait mindfulness are associated with positive mental and physical health measure for caregivers. Future research would benefit from further examining mindfulness-based interventions and their impacts in mitigating the negative toll of caregiving in the context of cancer.

Tridentate imidazole-based Schiff base metal complexes: molecular docking, structural and biological studies

A novel Schiff base was synthesized by the condensation of imidazole-2-carboxaldehyde with l-histidine in an equimolar ratio. The prepared Schiff base was characterized by elemental analysis and spectral characterization techniques. It was then complexed with a series of 3-d metal(II) ions like manganese, iron, cobalt, nickel, copper and zinc. The coordination properties, nature of bonding and stability of the complexes were deduced from elemental analysis, IR, UV-vis, ¹H NMR, mass, electronic spectra, magnetic, conductivity and thermogravimetric analysis. IR studies support the tridentate behaviour of Schiff base as well as its coordination to the central metal ion through an azomethine nitrogen, deprotonated carboxylic oxygen and imidazole ring nitrogen atoms of histidine. The electronic spectra and magnetic moment data demonstrate that the complexes have an octahedral geometry, except zinc complex, which has a tetrahedral geometry. In vitro antimicrobial activity of the synthesized compounds has been shown to exhibit excellent antibacterial and antifungal activities. The antibacterial property of the prepared Schiff base was further confirmed by conducting a docking study of target proteins involved in the antibacterial mechanism.Communicated by Ramaswamy H. Sarma.

A training model to teach early management of priapism

BACKGROUND

Ischaemic priapism is a urological emergency with early treatment required to prevent irreversible loss of erectile function. Corporal aspiration is the first step in management. Currently, there are no satisfactory training models to develop skills in a controlled environment. We have therefore developed a novel training model to teach trainees the steps of penile aspiration in a safe and representative way.

MATERIALS AND METHODS

We have developed a priapism model using an old catheterisation teaching model. Face validity of the model was assessed by participants and experienced urologists teaching on a urology boot camp. All had managed at least 5 cases of actual priapism. Responses were reported using a 5-point Likert Scale. Data were analysed using IBM SPSS Statistics V25. The intra-class correlation was calculated using a «One-way Random model».

RESULTS

Eleven urologists and seven trainees participated in the evaluation. The model appearance was reported as the best simulation trait of the priapism model. Tactile feedback from needle insertion for aspiration was also felt to be realistic with 72.6% reporting it as «Good» or «very good» and 85.7% reported the model to be realistic for needle insertion. Intra-class correlation amongst experts was 0.552. Majority of trainees (83.3%) reported a realistic simulation. All evaluators agreed or strongly agreed that the model provided a good simulated experience that would be useful in training.

CONCLUSION

Our model provides a realistic simulation of corporal aspiration. It can be used repeatedly. Overall, the proposed model appears to be a promising tool for training junior doctors in the initial management of ischaemic priapism.

Mechanisms of Atomization from Rotary Dental Instruments and Its Mitigation

Since the onset of coronavirus disease 2019, the potential risk of dental procedural generated spray emissions (including aerosols and splatters), for severe acute respiratory syndrome coronavirus 2 transmission, has challenged care providers and policy makers alike. New studies have described the production and dissemination of sprays during simulated dental procedures, but findings lack generalizability beyond their measurements setting. This study aims to describe the fundamental mechanisms associated with spray production from rotary dental instrumentation with particular focus on what are currently considered high-risk components-namely, the production of small droplets that may remain suspended in the room environment for extended periods and the dispersal of high-velocity droplets resulting in formites at distant surfaces. Procedural sprays were parametrically studied with variables including rotation speed, burr-to-tooth contact, and coolant premisting modified and visualized using high-speed imaging and broadband or monochromatic laser light-sheet illumination. Droplet velocities were estimated and probability density maps for all laser illuminated sprays generated. The impact of varying the coolant parameters on heating during instrumentation was considered. Complex structured sprays were produced by water-cooled rotary instruments, which, in the worst case of an air turbine, included droplet projection speeds in excess of 12 m/s and the formation of millions of small droplets that may remain suspended. Elimination of premisting (mixing of coolant water and air prior to burr contact) resulted in a significant reduction in small droplets, but radial atomization may still occur and is modified by burr-to-tooth contact. Spatial probability distribution mapping identified a threshold for rotation speeds for radial atomization between 80,000 and 100,000 rpm. In this operatory mode, cutting efficiency is reduced but sufficient coolant effectiveness appears to be maintained. Multiple mechanisms for atomization of fluids from rotatory instrumentation exist, but parameters can be controlled to modify key spray characteristics during the current crisis.

Pre-Flight Calibration of the Mars 2020 Rover Mastcam Zoom (Mastcam-Z) Multispectral, Stereoscopic Imager

The NASA Perseverance rover Mast Camera Zoom (Mastcam-Z) system is a pair of zoomable, focusable, multi-spectral, and color charge-coupled device (CCD) cameras mounted on top of a 1.7 m Remote Sensing Mast, along with associated electronics and two calibration targets. The cameras contain identical optical assemblies that can range in focal length from 26 mm ( 25.5 ∘ × 19.1 ∘ FOV ) to 110 mm ( 6.2 ∘ × 4.2 ∘ FOV ) and will acquire data at pixel scales of 148-540 μm at a range of 2 m and 7.4-27 cm at 1 km. The cameras are mounted on the rover's mast with a stereo baseline of 24.3 ± 0.1  cm and a toe-in angle of 1.17 ± 0.03 ∘ (per camera). Each camera uses a Kodak KAI-2020 CCD with 1600 × 1200 active pixels and an 8 position filter wheel that contains an IR-cutoff filter for color imaging through the detectors' Bayer-pattern filters, a neutral density (ND) solar filter for imaging the sun, and 6 narrow-band geology filters (16 total filters). An associated Digital Electronics Assembly provides command data interfaces to the rover, 11-to-8 bit companding, and JPEG compression capabilities. Herein, we describe pre-flight calibration of the Mastcam-Z instrument and characterize its radiometric and geometric behavior. Between April 26 t h and May 9 t h , 2019, ∼45,000 images were acquired during stand-alone calibration at Malin Space Science Systems (MSSS) in San Diego, CA. Additional data were acquired during Assembly Test and Launch Operations (ATLO) at the Jet Propulsion Laboratory and Kennedy Space Center. Results of the radiometric calibration validate a 5% absolute radiometric accuracy when using camera state parameters investigated during testing. When observing using camera state parameters not interrogated during calibration (e.g., non-canonical zoom positions), we conservatively estimate the absolute uncertainty to be < 10 % . Image quality, measured via the amplitude of the Modulation Transfer Function (MTF) at Nyquist sampling (0.35 line pairs per pixel), shows MTF Nyquist = 0.26 - 0.50 across all zoom, focus, and filter positions, exceeding the > 0.2 design requirement. We discuss lessons learned from calibration and suggest tactical strategies that will optimize the quality of science data acquired during operation at Mars. While most results matched expectations, some surprises were discovered, such as a strong wavelength and temperature dependence on the radiometric coefficients and a scene-dependent dynamic component to the zero-exposure bias frames. Calibration results and derived accuracies were validated using a Geoboard target consisting of well-characterized geologic samples.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s11214-021-00795-x.

Ultrasound-guided Fascia Iliaca Plane Block for the treatment of donor site pain in the burn injured patient: a randomized control trial

Burn injuries requiring surgical intervention often result in split- thickness skin grafting procedures, with donor skin frequently harvested from the patient's anterolateral thigh. The donor site is often reported as the primary site of post-operative pain due to the damage sustained to localised nociceptors.A randomised control trial was undertaken to evaluate the impact an ultrasound-guided regional nerve block would have on patient reported pain scores in donor site wounds, and associated rescue analgesia consumption. Twenty participants requiring split-skin grafting for burn injuries of <15% total body surface area were enrolled from a tertiary burns unit and randomised to control (10 participants) or intervention group (10 participants). The intervention group received the addition of an ultrasound-guided facia iliaca plane block prior to their surgery. Primary outcome was pain score in the donor site during the postoperative phase; while secondary outcome was pain on day 1 post-surgery as measured by the numeric pain score (0-10). During the post-operative phase, the intervention group had a significantly lower median donor site pain score of 0 (interquartile range (IQR) 0 - 0), compared to the control group median 6 (IQR 4 - 7) (p < 0.001). Day 1 post-surgery the intervention group had a median pain score of 0 (IQR 0 - 4) compared to control group median 4.5 (IQR 2 - 6) (p= 0.043).The study findings demonstrated that regional anaesthesia was an effective way to reduce pain scores and requirement for additional analgesics during the postoperative phase.

Comparison of various instantaneous pulmonary arterial wedge pressure measurements with prognostic validation

Background

Current recommendations on the diagnosis of pulmonary hypertension due to left heart disease (PH-LHD) emphasize the need for standardization of pulmonary arterial wedge pressure (PAWP) measurement. Instead of mean PAWP values instantaneous mid-A wave pressures or, in case of atrial fibrillation (AF), measurement 130–160 ms after the QRS onset is recommended. Recently, PAWP at the QRS onset has also been proposed. Our aim was to compare the various instantaneous PAWP measurements and assess the prognostic value of the derived diastolic pressure gradients (DPG) in heart failure (HF) patients.

Methods and results

PAWP and pulmonary arterial pressure (PAP) tracings of 116 patients with PH-LHD were manually analyzed offline. PAWP was measured in 4 different ways: 1. mean value [PAWPM]; 2.mid-A wave value in sinus, and at 10 ms intervals 130–160 ms following QRS onset in AF [PAWPR]; 3. at the onset of the QRS complex [PAWPQRS]; 4. pre C-wave point value [PAWPC]. The pre C-wave point was chosen as a reference for truly end-diastolic pressures. The corresponding DPGM, DPGR, DPGQRS and DPGC were calculated. The patients were followed for 17 (8–27) months and the prognostic value of the various DPG measurements for predicting all-cause mortality was assessed. The pre C-wave point was identifiable in 35 patients (30%); on average it occurred 171 ms after the QRS-onset whereas the A wave-onset and A-wave peak happened on average 62 and 149 ms after the QRS-onset, respectively. All three instantaneous PAWP measurements gave significantly lower values than PAWPM [19.3 (15.4–25.0)]. PAWPR did not differ from PAWPC [18.1 mmHg (14–22) vs. 19.2 mmHg (13–22.8), p=0.9], whereas PAWPQRS was lower [15.8 mmHg (12.2–19.9), p&lt;0.001]. Accordingly, all instantaneous DPG measurements were higher than DPGM, yielding lower prevalence of negative DPG (29%, 17% and 45%, for DPGR, DPGQRS and DPGM, respectively). In AF (n=30), DPGR values at 130–140–150–160 ms demonstrated increasing scatter and progressively overestimated DPGQRS. For prognostic assessment, in case of both DPGQRS and DPGR, 6 mmHg was identified as a best cut-off value for predicting all-cause mortality, at which both indices provided superior prognostic information than DPGM [DPGR: HR 2.7; CI 1.1–6.9, p=0.029; DPGQRS: HR 2.6; CI 1.1–6.4, p=0.037, high-risk cases 17 for both; DPGM: HR 2.8; CI 1.0–7.6, p=0.045, high-risk cases 10].

Conclusions

PAWP measured at the mid-A wave provides a reliable assessment of the end-diastolic PAWP in sinus rhythm. On the other hand, ECG-gated measurements yield more robust evaluation of PAWP in AF. Finally, both approaches carry significant and similar prognostic information in PH-LHD.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): AIN was supported by the János Bolyai Scholarship of the Hungarian Academy of Sciences

Development of Coagulation Factor XII Antibodies for Inhibiting Vascular Device-Related Thrombosis

Introduction

Vascular devices such as stents, hemodialyzers, and membrane oxygenators can activate blood coagulation and often require the use of systemic anticoagulants to selectively prevent intravascular thrombotic/embolic events or extracorporeal device failure. Coagulation factor (F)XII of the contact activation system has been shown to play an important role in initiating vascular device surface-initiated thrombus formation. As FXII is dispensable for hemostasis, targeting the contact activation system holds promise as a significantly safer strategy than traditional antithrombotics for preventing vascular device-associated thrombosis.

Objective

Generate and characterize anti-FXII monoclonal antibodies that inhibit FXII activation or activity.

Methods

Monoclonal antibodies against FXII were generated in FXII-deficient mice and evaluated for their binding and anticoagulant properties in purified and plasma systems, in whole blood flow-based assays, and in an in vivo non-human primate model of vascular device-initiated thrombus formation.

Results

A FXII antibody screen identified over 400 candidates, which were evaluated in binding studies and clotting assays. One non-inhibitor and six inhibitor antibodies were selected for characterization in functional assays. The most potent inhibitory antibody, 1B2, was found to prolong clotting times, inhibit fibrin generation on collagen under shear, and inhibit platelet deposition and fibrin formation in an extracorporeal membrane oxygenator deployed in a non-human primate.

Conclusion

Selective contact activation inhibitors hold potential as useful tools for research applications as well as safe and effective inhibitors of vascular device-related thrombosis.

A review of social determinants of health for dashboard development for SDG 3.4 for sub-Sahara Africa

Background

All sustainable developmental goals (SDGs) require implementing sustainable strategies and monitoring to track progress. But what is known of sub-Sahara Africa (SSA)'s efforts in following this stride to reduce by 30% mortality from non-communicable diseases (NCDs) through prevention (SDG 3.4), by considering the effect of social determinants of health (SODHs) on type 2 diabetes increasing prevalence?

Methods

Our search produced 2005 unique articles. Only 10 studies were used in the analysis of this study. These studies include 1 from Botswana, 2 from Ghana, 2 from Kenya, 3 from Nigeria and 2 from South Africa. The findings were evaluated in a greater extent.

Results

All studies (100%) showed non-adherence to exercise and poor glycemic control. 7 studies (70%) on education revealed lack of knowledge or misconceptions, 5 studies (50%) with obesity showed a strong linkage between obesity and type 2 diabetes, and 4 studies (40%) on diet, showed diets high in carbohydrates, saturated fats, and sodium predisposition to type 2 diabetes. All studies (100%) linked urbanization with an increased prevalence of type 2 diabetes.

Conclusions

Changes in SODHs seem to be contributing to the growing prevalence of diabetes in SSA. These changes with other key data should be considered and tailored to policy processes, environment, infrastructures, and norms for prevention strategies and informing dashboard development for SDG 3.4.

Key messages

Social determinants of health must reflect in relevant causal pathways, settings, and sectors for preventive intervention such as in taxation; regulation of food advertising, school, and healthcare. Analysis of the effect of the changing social determinants of health on type 2 diabetes, will assist in establishing indicators for the dashboard development for SDG 3.4 for sub-Sahara Africa.

Evidence-based health security: The nexus of governance and pandemic preparedness

Background

Pandemic preparedness continues to be an important focus of the global health security agenda. Many nations in the sub-Saharan African region remain at high risk for a major pandemic due to limited capacity and endemic co-morbid conditions in their populations. While the literature does suggest that state capacity influences health, no studies to date indicate an association between state capacity and pandemic disease distribution, particularly in the presence of other endemic diseases.

Methods

This mixed methods study will contribute to existing research by examining how economic and sociopolitical attributes of state capacity influence pandemic-prone disease distribution in sub-Saharan Africa. A convergent mixed methods design was used to collect and analyze quantitative state capacity attributes and prevention, and control using correlation in six sub-Saharan countries. Results of the quantitative study were triangulated through the use of an expert panel and results integrated for an overall interpretation and conclusion.

Results

Variables in the study showed statistically significant relationships between proxies of state capacity and the follow areas: control of pandemics and prevention of pandemics. The Expert Panel interviews illustrated convergence between the correlated results.

Conclusions

This study brought forward associations with expert confirmation suggestive of areas for national governments in sub-Saharan Africa to further review and improve. While many internal factors limit state capacity in these nations (e.g. human and fiscal resources), external funders may consider adding information from this study and other metrics to test progress.

Key messages

Evidence is valuable for pandemic preparedness planning. Nation state capacity is a factor in pandemic preparedness.

Citizens' juries give verdict on whether private practice veterinarians should attend unvaccinated Hendra virus suspect horses

BACKGROUND

Hendra virus (HeV) is endemic in Australian flying foxes, posing a threat to equine and human health. Equine vaccination remains the most effective risk mitigation strategy. Many horses remain unvaccinated - even in higher-risk regions. Debate surrounding the vaccine's use is characterised by conflicting perspectives, misunderstanding and mistrust. Private veterinary practitioners are critical to early identification of public health risk through recognition, sampling and management of suspect-equine-HeV-cases. However, managing such cases can be burdensome, with some veterinarians opting not to attend unvaccinated horses or to abandon equine practice because of risk posed by HeV disease and liability.

OBJECTIVE

Ascertain the perspectives of informed citizens on what obligations (if any) private veterinarians have to attend unvaccinated horses with HeV or HeV-like disease.

METHODS

Three citizens' juries were tasked with considering approaches to managing HeV risk in Australia, including (reported here) roles and obligations of private veterinarians in responding to HeV-suspect-cases.

RESULTS

Jurors acknowledged that HeV management posed an important challenge for private veterinarians. A clear majority (27 of 31 jurors) voted that veterinarians should not be obliged to attend unvaccinated horses. All recognised that greater support for veterinarians should be a priority.

CONCLUSIONS

When informed of HeV risks and strategies for control and management, citizens appreciated the need to support veterinarians performing this critical 'One Health' role for public benefit. The current governance framework within which zoonotic disease recognition and response operates limits the contingency and scope for increasing support and efficacy of these important veterinary public health practices.

Multicenter Postmarket Analysis of the Neuroform Atlas Stent for Stent-Assisted Coil Embolization of Intracranial Aneurysms

BACKGROUND AND PURPOSE

The Neuroform Atlas is a new microstent to assist coil embolization of intracranial aneurysms that recently gained FDA approval. We present a postmarket multicenter analysis of the Neuroform Atlas stent.

MATERIALS AND METHODS

On the basis of retrospective chart review from 11 academic centers, we analyzed patients treated with the Neuroform Atlas after FDA exemption from January 2018 to June 2019. Clinical and radiologic parameters included patient demographics, aneurysm characteristics, stent parameters, complications, and outcomes at discharge and last follow-up.

RESULTS

Overall, 128 aneurysms in 128 patients (median age, 62 years) were treated with 138 stents. Risk factors included smoking (59.4%), multiple aneurysms (27.3%), and family history of aneurysms (16.4%). Most patients were treated electively (93.7%), and 8 (6.3%) underwent treatment within 2 weeks of subarachnoid hemorrhage. Previous aneurysm treatment failure was present in 21% of cases. Wide-neck aneurysms (80.5%), small aneurysm size (<7 mm, 76.6%), and bifurcation aneurysm location (basilar apex, 28.9%; anterior communicating artery, 27.3%; and middle cerebral artery bifurcation, 12.5%) were common. A single stent was used in 92.2% of cases, and a single catheter for both stent placement and coiling was used in 59.4% of cases. Technical complications during stent deployment occurred in 4.7% of cases; symptomatic thromboembolic stroke, in 2.3%; and symptomatic hemorrhage, in 0.8%. Favorable Raymond grades (Raymond-Roy occlusion classification) I and II were achieved in 82.9% at discharge and 89.5% at last follow-up. mRS ≤2 was determined in 96.9% of patients at last follow-up. The immediate Raymond-Roy occlusion classification grade correlated with aneurysm location (P < .0001) and rupture status during treatment (P = .03).

CONCLUSIONS

This multicenter analysis provides a real-world safety and efficacy profile for the treatment of intracranial aneurysms with the Neuroform Atlas stent.