Development and validation of 3D printed anthropomorphic head phantom with eccentric holes for medical LINAC quality assurance testing in stereotactic radiosurgery

Stereotactic Radiosurgery (SRS) for brain tumors using Medical Linear Accelerator (LINAC) demands high precision and accuracy. A specific Quality Assurance (QA) is essential for every patient undergoing SRS to protect nearby non-cancerous cells by ensuring that the X-ray beams are targeted according to tumor position. In this work, a water-filled generic anthropomorphic head phantom consisting of two removable parts with eccentric holes was developed using Additive Manufacturing (AM) process for performing QA in SRS. In the patient specific QA, the planned radiation dose using Treatment Planning System (TPS) was compared with the dose measured in the phantom. Also, the energy consistency of radiation beams was tested at 200 MU for different energy beams at the central and eccentric holes of the phantom using an ionization chamber. Experimentally examined results show that planned doses in TPS are reaching the target within a 5% deviation. The ratio of the dose delivered in the eccentric hole to the dose delivered to the central hole shows variations of less than 2% for the energy consistency test. The designed, low-cost water-filled anthropomorphic phantom is observed to improve positioning verification and accurate dosimetry of patient-specific QA in SRS treatment.

The injury patterns, management and outcomes of retroperitoneal haemorrhage caused by lumbar arterial bleeding at a Level-1 Trauma Centre: A 10-year retrospective review

PURPOSE

Haemorrhagic shock remains a leading preventable cause of death amongst trauma patients. Failure to identify retroperitoneal haemorrhage (RPH) can lead to irreversible haemorrhagic shock. The arteries of the middle retroperitoneal region (i.e., the 1st to 4th lumbar arteries) are complicit in haemorrhage into the retroperitoneal space. However, predictive injury patterns and subsequent management implications of haemorrhage secondary to bleeding of these arteries is lacking.

MATERIALS AND METHODS

We performed a retrospective cohort study of patients diagnosed with retroperitoneal haemorrhage who presented to our Level-1 Trauma Centre (2009-2019). We described the associated injuries, management and outcomes relating to haemorrhage of lumbar arteries (L1-4) from this cohort to assess risk and management priorities in non-cavitary haemorrhage compared to RPH due to other causes.

RESULTS

Haemorrhage of the lumbar arteries (LA) is associated with a higher proportion of lumbar transverse process (TP) fractures. Bleeding from branches of these vessels is associated with lower systolic blood pressure, increased incidence of massive transfusion, higher shock index, and a higher Injury Severity Score (ISS). A higher proportion of patients in the LA group underwent angioembolisation when compared to other causes of RPH.

CONCLUSION

This study highlights the injury patterns, particularly TP fractures, in the prediction, early detection and management of haemorrhage from the lumbar arteries (L1-4). Compared to other causes of RPH, bleeding of the LA responds to early, aggressive haemorrhage control through angioembolisation. These injuries are likely best treated in Level-1 or Level-2 trauma facilities that are equipped with angioembolisation facilities or hybrid theatres to facilitate early identification and management of thoracolumbar bleeds.

A fully implantable wireless bidirectional neuromodulation system for mice

Novel research in the field of bioelectronic medicine requires neuromodulation systems that pair high-performance neurostimulation and bio-signal acquisition hardware with advanced signal processing and control algorithms. Although mice are the most commonly used animal in medical research, the size, weight, and power requirements of such bioelectronic systems either preclude use in mice or impose significant constraints on experimental design. Here, a fully-implantable recording and stimulation neuromodulation system suitable for use in mice is presented, measuring 2.2 cm3 and weighing 2.8 g. The bidirectional wireless interface allows simultaneous readout of multiple physiological signals and complete control over stimulation parameters, and a wirelessly rechargeable battery provides a lifetime of up to 5 days on a single charge. The device was implanted to deliver vagus nerve stimulation (n = 12 animals) and a functional neural interface (capable of inducing acute bradycardia) was demonstrated with lifetimes exceeding three weeks. The design utilizes only commercially-available electrical components and 3D-printed packaging, with the goal of facilitating widespread adoption and accelerating discovery and translation of future bioelectronic therapeutics.

Enhancing Wheat Disease Diagnosis in a Greenhouse Using Image Deep Features and Parallel Feature Fusion

Since the assessment of wheat diseases (e.g., leaf rust and tan spot) via visual observation is subjective and inefficient, this study focused on developing an automatic, objective, and efficient diagnosis approach. For each plant, color, and color-infrared (CIR) images were collected in a paired mode. An automatic approach based on the image processing technique was developed to crop the paired images to have the same region, after which a developed semiautomatic webtool was used to expedite the dataset creation. The webtool generated the dataset from either image and automatically built the corresponding dataset from the other image. Each image was manually categorized into one of the three groups: control (disease-free), disease light, and disease severity. After the image segmentation, handcrafted features (HFs) were extracted from each format of images, and disease diagnosis results demonstrated that the parallel feature fusion had higher accuracy over features from either type of image. Performance of deep features (DFs) extracted through different deep learning (DL) models (e.g., AlexNet, VGG16, ResNet101, GoogLeNet, and Xception) on wheat disease detection was compared, and those extracted by ResNet101 resulted in the highest accuracy, perhaps because deep layers extracted finer features. In addition, parallel deep feature fusion generated a higher accuracy over DFs from a single-source image. DFs outperformed HFs in wheat disease detection, and the DFs coupled with parallel feature fusion resulted in diagnosis accuracies of 75, 84, and 71% for leaf rust, tan spot, and leaf rust + tan spot, respectively. The methodology developed directly for greenhouse applications, to be used by plant pathologists, breeders, and other users, can be extended to field applications with future tests on field data and model fine-tuning.

Characteristics of the leachate produced during nutrient recycling of food and poultry slaughter wastes by fly larvae

Biowaste management is a pertinent problem and nutrient recycling utilizing fly larvae is an emerging solution. The leachate produced during biowaste management has potential implications for the environment but studies on this issue are scanty. This study was conducted to assess the characteristics of leachate produced during the bioconversion of food (BW-I) and poultry slaughter waste (BW-II) by natural fly larval activity. The results showed that total volumes of 2.2 L and 1.1 L leachate were produced for BW-I and II respectively. The highest pH in BW-I leachate was 7.43 ± 0.01 and the lowest pH in BW-II was 3.30 ± 0.12. The highest levels of BOD in BW-I and II were 36733.33 ± 430.63 mg/l and 2800.000 ± 999.50 mg/l. The highest level of COD in BW-I was 52575.000 ± 1076.86mg/l while in BW-II it was 4316.67 ± 790.45 mg/l. The high BOD and COD values of the leachate indicated that they needed to be pretreated before being released into the environment.

Drug Resistance Reversal Potential of Nanoparticles/Nanocomposites via Antibiotic's Potentiation in Multi Drug Resistant P. aeruginosa

Bacteria employ numerous resistance mechanisms against structurally distinct drugs by the process of multidrug resistance. A study was planned to discover the antibacterial potential of a graphene oxide nanosheet (GO), a graphene oxide-zinc oxide nanocomposite (GO/ZnO), a graphene oxide-chitosan nanocomposite (GO-CS), a zinc oxide decorated graphene oxide-chitosan nanocomposite (GO-CS/ZnO), and zinc oxide nanoparticles (ZnO) alone and in a blend with antibiotics against a PS-2 isolate of Pseudomonas aeruginosa. These nanocomposites reduced the MIC of tetracycline (TET) from 16 folds to 64 folds against a multidrug-resistant clinical isolate. Efflux pumps were interfered, as evident by an ethidium bromide synergy study with nanocomposites, as well as inhibiting biofilm synthesis. These nanoparticles/nanocomposites also decreased the mutant prevention concentration (MPC) of TET. To the best of our knowledge, this is the first report on nanomaterials as a synergistic agent via inhibition of efflux and biofilm synthesis.

Formulation and performance evaluation of polymeric mixed micelles encapsulated with baicalein for breast cancer treatment

The present study is aimed to formulate baicalein-loaded mixed micelles to enhance the solubility and oral bioavailability. Baicalein encapsulated D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) and pluronic F127 (F127) combined micelles were prepared and investigated for anticancer effect. The optimized formulation contains 25.04 ± 0.24 nm mean particle size of micelles with a zeta potential value of -4.01 ± 0.5 mV. The calculated entrapment efficiency percentage of baicalein within the micellar structure was 83.43 ± 0.13% and the in vitro release of baicalein from micelles displayed a sustained release profile at pH 7.4. The incorporation of baicalein within micelles core was also confirmed by FTIR analysis of formulation, which hardly represents the characteristic peak of baicalein, indicating successful entrapment of the drug. In vitro cell culture experiments revealed baicalein-loaded micelles significantly enhanced cellular uptake and cytotoxicity against MDAMB-231 cell lines in comparison to free baicalein. Additionally, as compared to free baicalein, baicalein micelles demonstrated greater apoptosis-inducing potential while the results of the cell cycle study exhibited arrest of cells at the G0/G1 phase of the cell cycle. Results of ROS (reactive oxygen species) and MMP (mitochondrial membrane potential) assay revealed the ROS-dependent mitochondrial-mediated apoptosis pathway utilized by developed formulation to inhibit cell proliferation. Thus, the developed nano micelles can serve as a potent carrier system for baicalein against breast cancer.

Nutrient concentrations and distribution of phytoplankton pigments in recently deposited sediments of a positive tropical estuary

Investigation of nutrients in the water column and phytoplankton pigments in recently formed modern sediments (0-5 cm) was carried out in Cochin estuary. The anthropogenic impacts were assessed using nutrients, nitrate, and phosphate in combination with phytopigments in sediments. The nitrate and phosphate concentration during the study ranged from 0.81 to 42.53 μmol/L and from 0.1 to 5.81 μmol/L, respectively. The mean values of the pigment showed the following order: zeaxanthin (791.53 ng/g) > lutein (347.57 ng/g) > fucoxanthin (335.30 ng/g) > pheophytin (308.84 ng/g) > pheophorbide (172.06 ng/g) > chlorophyll a (161.63 ng/g). The increase in the concentration of zeaxanthin indicated the presence of cyanobacteria, associated with eutrophication. Correlation analysis revealed that water column nutrients have a strong relationship between fucoxanthin and lutein, indicating the coexistence of diatoms and prasinophytes in the sampling sites. The principal component analysis showed positive loading of nutrients concomitant with pigment fucoxanthin and lutein, thus establishing that nutrient input controls the phytoplankton biomass of this estuary.

AB0360 A DECADE OF SUSPECTED GIANT CELL ARTERITIS: CLINICAL FEATURES OF A HIGHLY HETEROGENEOUS DISEASE

Background:

Giant cell arteritis is the most common chronic systemic vasculitis in older adults. Permanent visual loss is the most concerning complication can occur in up to 20% of patients (1). Diagnosis is based on a combination of clinical findings, laboratory evidence of inflammatory markers, and temporal artery biopsy (TAB) confirming histologic evidence of inflammation. There are no definitive markers of the disease when TAB is negative.

Objectives:

The objective of this study was to illustrate the clinical features of subjects suspected with GCA evaluated at the Dallas Veterans Affairs Medical Center (VAMC) and identify those features that would differentiate between TAB positive GCA, TAB negative GCA and non-GCA patients.

Methods:

This retrospective study searched the Dallas VAMC database for subjects between January of 2010 until December 2019 with ICD-9 and ICD-10 entry code for GCA. Based on the 1990 ACR clinical classification criteria for GCA, suspected patients were classified as TAB positive GCA, TAB negative GCA and non-GCA. Subjects with incomplete data needed for classification were excluded. Group comparisons were performed with Fisher’s exact test for categorical variables and the Mann-Whitney test for continuous variables.

Results:

One-hundred and sixty-nine subjects had ICD-9/10 entry code for GCA. Ophthalmology was the specialty who did the initial evaluation in 46% of the suspected cases. Seventy-one patients were excluded due to incomplete data. Of the remaining 98 patients, 42 (42.9%) were diagnosed with GCA out of which 10 patients had a positive TAB. Seventy-six percent of patients diagnosed with GCA had negative temporal artery biopsies. In 56 (57.1%) patients GCA was ruled out (Figure 1). New-onset headache was the predominant symptom suggestive of GCA affecting 88.9% TAB positive and 100% of TAB negative cases compared to 56.6% of non-GCA patients (p< 0.001), followed by scalp tenderness in 33.3%, 58.1% and 10.9%, respectively (p< 0.001), jaw claudication in 57.1%, 34.5% and 14.9% (p=0.021), and elevated sedimentation rate in 33%, 65.6% and 33% (p=0.013) (Table 1). Polymyalgia rheumatica was present in 28.6% and 21.7% of patients diagnosed with GCA compared to zero percent in non-GCA cases (p=0.017). More than 30% of patients with GCA had normal acute phase reactants in this cohort.

Table 1.

Comparison of demographics and clinical features of patients with suspected GCA

GCA TAB Positive (n=10)GCA - TAB Negative (n=32)non-GCA (n=56)n%n%n%pAge (mean/sd)71.3 (7.8)67.3 (8.1)67.3 (8.9)0.367Male99030/3293.851/5691.10.885Clinical findingsNew onset headache8/988.932/3210030/5356.6<0.001Visual symptoms9/109022/3268.842/5477.80.351Jaw claudication4/757.110/2934.57/4714.90.021PMR2/728.65/2321.70/3000.017Scalp tenderness2/633.318/3158.15/4610.9<0.001Fever0/505/2321.72/355.70.117ESR > 501/333.321/3265.618/5433.30.013CRP > 101/333.35/3016.76/5411.10.473Anemia (hemoglobin < 12 g/ dl)2/728.615/3246.921/5240.40.642Thrombocytosis (platelets >400)2/728.63/329.44/517.80.228

Conclusion:

There is clinical heterogeneity within the patients diagnosed with GCA regardless of TAB. A high index of clinical suspicion needs to be the cornerstone of diagnosis. There is need for new classification criteria to include patients with negative TAB.

References:

[1]Soriano A, et al. Nat Rev Rheumatol. 2017 Aug;13(8):476-484.

Disclosure of Interests:

Adela Castro: None declared, Jiby Mathew: None declared, Ola Azzouqah: None declared, Jesus Diaz: None declared, Andreas Reimold Consultant of: Lilly, Grant/research support from: Abbvie

Pfizer

Gilead, Kyawt Shwin: None declared

Evaluation of Anti-quorum Sensing Potential of Saraca asoca (Family Caesalpiniaceae) against Chromobacterium violaceum and Pseudomonas aeruginosa PA01

Aim: The present study was performed to evaluate the anti-quorum sensing (QS) potential of traditional medicinal herb Saracaasoca (family Caesalpiniaceae) stem bark extract against Chromobacterium violaceum and Pseudomonas aeruginosa PA01. Study Design: First, the test sample (bark extract) was screened for anti-QS activity. Then systematic in-vitro and biochemical tests were performed to evaluate the effect of the test sample on the QS mediated virulence factors. Place and Duration of Study: All the experimental works were performed in Lab 311, pharmacology division, CSIR-NBRI Lucknow from June 2019 to October 2019. Methodology: The samples of Saraca asoca stem bark were washed, dried and extracted using 70% methanol. The minimum inhibitory concentration (MIC) of the prepared Sarca asoca bark extract was determined using the Alamar blue assay, and the anti-QS activity was screened using standard agar overlay method against CV 12472 at subinhibitory concentrations 100, 200 and 300 µg (< MIC value). SAE effect on biofilms formation was assessed by growing biofilms on glass slides in a static culture of PA01. Anti-virulence effect of SAE on the production of QS-regulated virulence factors such as Pyocyanin, proteases, elastases, rhamnolipid and alginate in Pseudomonas aeruginosa was determined using the supernatant of a 24 hours old broth culture of PA01 supplemented with SAE. Using the agar plate technique, the swimming and swarming motility assays were conducted on 0.3% and 0.5% agar plates respectively. One-way ANOVA was used to analyze the data, presented as mean ± SD (standard deviation) of three independent experiments. Results: Preliminary screening results showed significant QS inhibition against CV 12472 in an agar overlay disk diffusion assay in a concentration-dependent manner. Data from the biofilm assay showed loose, distorted, irregular PA01 biofilm formation at 200 µg (48%) and 300 µg (65%). SAE caused a significant drop in virulence factor production, with maximum reduction in pyocyanin (58%), proteases (67%), elastases (52%), rhamnolipid (53%), and alginate (44%) observed at 300 µg concentration. At SAE sub-lethal concentrations (200 and 300 µg), both the swimming and swarming motility of PA01 were significantly inhibited. Conclusions: The present study demonstrates the broad-spectrum anti-QS potential of SAE, reported for the first time, suggesting that SAE could be considered as an alternative herbal source to develop antimicrobial agents which can be either solitary or synergistically with conventional antimicrobial drugs.

40 Improving Urinary Catheter Documentation and Care in Geriatric Wards

Introduction

NICE guidelines state that urinary catheter insertion, changes and care should be documented. Duration of catheterization is directly linked to the risk of developing a catheter-associated UTI. Furthermore, Public Health England has announced a national aim to reduce the incidence of Gram-negative bacteraemia by 50% by March 2021, and targeting catheters is one of the first steps.

Local problem

These issues are relevant to the elderly population at Princess Royal University Hospital, where documentation surrounding catheters was found to be inadequate. Despite there being an Electronic Patient Record (EPR) order for catheter insertion and monitoring available, this was not being used. Our primary aim was for all patients to have this order. We also hoped to reduce the weekly rate of catheter days (catheter days per 100 bed days), and improve documentation in clinical notes.

Methods

We focused on two medical wards and sampled all patients admitted over a period of 4 months who had a catheter at the time of data collection. We identified catheterized patients and whether they had an EPR catheter order on a daily basis. Additional parameters such as indication, insertion date, inserter, and documentation standards were extracted from EPR on a weekly basis. Patients were kept “live” and contributing to catheter day calculations until they were no longer on the ward or if the catheter was removed.

Interventions

We implemented changes over 2 PDSA cycles. Interventions included the addition of catheter columns to boards and education sessions for doctors and nurses (cycle 1), as well as catheter posters, alert cards, and circulation of emails with guidance to doctors and nursing staff (cycle 2).

Results

A total of 87 patients were analysed during the project. There was an increase in EPR orders being used, with the 100% target being reached on the final data collection point, and with data showing a significant shift above baseline. Furthermore, there was a decrease in the weekly rate of catheter days, but changes were difficult to sustain. We also saw a general improvement in documentation standards.

Conclusion

By improving documentation and reducing unnecessary catheterization, we hope to have reduced the overall risk of infection whilst improving patient comfort and experience. Lessons may be transferrable to other trusts.

Penile fracture associated with complete urethra and bilateral corpora cavernosa transection

Penile fracture is a rare urological emergency caused by blunt trauma to the erect penis. It occurs due to the forcible bending of the turgid erect penis against resistance leading to tunica albuginea tear. The rupture of tunica albuginea surrounding the corpora cavernosa leads to hematoma formation and classical 'aubergine' deformity. Timely intervention is essential to improve sexual function. Urethral injury may occur concomitantly in case of severe trauma. Blood at the meatus, inability to void and haematuria are distinctive features. We describe a case of 36-year-old man who presented to the emergency department with penile fracture during sexual intercourse associated with blood at the meatus and voiding difficulty. On surgical exploration, complete bilateral corpora cavernosa tear and penile urethral transection was noted. The patient was successfully managed with timely repair. This case highlights the need for suspicion of an associated urethral injury in patients of penile fracture with blood at the meatus.