Feasibility study of computational occupational dosimetry: evaluating a proof-of-concept in an endovascular and interventional cardiology setting

Individual monitoring of radiation workers is essential to ensure compliance with legal dose limits and to ensure that doses are As Low As Reasonably Achievable. However, large uncertainties still exist in personal dosimetry and there are issues with compliance and incorrect wearing of dosimeters. The objective of the PODIUM (Personal Online Dosimetry Using Computational Methods) project was to improve personal dosimetry by an innovative approach: the development of an online dosimetry application based on computer simulations without the use of physical dosimeters. Occupational doses were calculated based on the use of camera tracking devices, flexible individualised phantoms and data from the radiation source. When combined with fast Monte Carlo simulation codes, the aim was to perform personal dosimetry in real-time. A key component of the PODIUM project was to assess and validate the methodology in interventional radiology workplaces where improvements in dosimetry are needed. This paper describes the feasibility of implementing the PODIUM approach in a clinical setting. Validation was carried out using dosimeters worn by Vascular Surgeons and Interventional Cardiologists during patient procedures at a hospital in Ireland. Our preliminary results from this feasibility study show acceptable differences of the order of 40% between calculated and measured staff doses, in terms of the personal dose equivalent quantity H_p(10), however there is a greater deviation for more complex cases and improvements are needed. The challenges of using the system in busy interventional rooms have informed the future needs and applicability of PODIUM. The availability of an online personal dosimetry application has the potential to overcome problems that arise from the use of current dosimeters. In addition, it should increase awareness of radiation protection among staff. Some limitations remain and a second phase of development would be required to bring the PODIUM method into operation in a hospital setting. However, an early prototype system has been tested in a clinical setting and the results from this two-year proof-of-concept PODIUM project are very promising for future development.

PERSONAL DOSIMETRY USING MONTE-CARLO SIMULATIONS FOR OCCUPATIONAL DOSE MONITORING IN INTERVENTIONAL RADIOLOGY: THE RESULTS OF A PROOF OF CONCEPT IN A CLINICAL SETTING

Exposure levels to staff in interventional radiology (IR) may be significant and appropriate assessment of radiation doses is needed. Issues regarding measurements using physical dosemeters in the clinical environment still exist. The objective of this work was to explore the prerequisites for assessing staff radiation dose, based on simulations only. Personal dose equivalent, Hp(10), was assessed using simulations based on Monte Carlo methods. The position of the operator was defined using a 3D motion tracking system. X-ray system exposure parameters were extracted from the x-ray equipment. The methodology was investigated and the simulations compared to measurements during IR procedures. The results indicate that the differences between simulated and measured staff radiation doses, in terms of the personal dose equivalent quantity Hp(10), are in the order of 30-70 %. The results are promising but some issues remain to be solved, e.g. an automated tracking of movable parts such as the ceiling-mounted protection shield.

Virtual estimation of effective dose in neutron fields

The PODIUM project aims to provide real-time assessments of occupationally exposed workers by tracking their motion and combining this with a simulation of the radiation field. The present work describes the approach that would be taken in mixed neutron-gamma fields, and details the methods for generating and applying an effective dose rate map; the required fluence to effective dose conversion coefficients at intercardinal angles are also presented. A proof-of-concept of the approach is demonstrated using a simple simulated workplace field within a calibration laboratory, with corroborative comparisons made against survey instrument measurements generally confirming good agreement. Simulated tracking of an individual within the facility was performed, recording a 1.25μSv total effective dose and accounting for dose rates as low as 0.5 nSv h^-1, which is much lower than anything that could be accurately measured by physical neutron dosemeters in such a field.

Obstetric Anal Sphincter Injuries: A Survey of Clinical Practice and Education among Obstetricians and Gynaecologists in Ireland

This paper summarises results of a survey of obstetricians in Ireland regarding their technique, management, and education on episiotomy and Obstetric Anal Sphincter Injury (OASIS). An anonymous survey was emailed to all obstetricians and gynaecologists in Ireland, including trainees between January and September 2017. The response rate was 45% (155/343) with 111 out of 144 (77%) reported clinical experience as part of their training and 92 (64%) attended an OASIS workshop or classroom teaching. The majority prescribe antibiotics and laxatives post-op, request physiotherapy review and follow-up patients in outpatient settings. We identified that most specialists and trainees practice within guidelines, but some recognise a need for further teaching and exposure to these types of injuries. These results will direct future curriculum and optimise ongoing training for trainees, unify service provision and contribute to patient safety.

Acquiring basic and advanced laparoscopic skills in novices using two-dimensional (2D), three-dimensional (3D) and ultra-high definition (4K) vision systems: A randomized control study

AIMS

To compare the performance of novices in laparoscopic peg transfer and intra-corporeal suturing tasks in two-dimensional (2D), three-dimensional (3D) and ultra-high definition (4K) vision systems.

METHODS

Twenty-four novices were randomly assigned to 2D, 3D and 4K groups, eight in each group. All participants performed the two tasks on a box trainer until reaching proficiency. Their performance was assessed based on completion time, number of errors and number of repetitions using the validated FLS proficiency criteria.

RESULTS

Eight candidates in each group completed the training curriculum. The mean performance time (in minutes) for the 2D group was 558.3, which was more than that of the 3D and 4K groups of 316.7 and 310.4 min respectively (P < 0.0001). The mean number of repetitions was lower for the 3D and 4K groups versus the 2D group: 125.9 and 127.4 respectively versus 152.1 (P < 0.0001). The mean number of errors was lower for the 4K group versus the 3D and 2D groups: 1.2 versus 26.1 and 50.2 respectively (P < 0.0001).

CONCLUSION

The 4K vision system improved accuracy in acquiring laparoscopic skills for novices in complex tasks, which was shown in significant reduction in number of errors compared to the 3D and the 2D vision systems. The 3D and the 4K vision systems significantly improved speed and accuracy when compared to the 2D vision system based on shorter performance time, fewer errors and lesser number of repetitions.

Malignant mesothelioma of the tunica vaginalis

Malignant mesothelioma of the tunica vaginalis is a rare but potentially fatal disease. Lack of characteristic clinical features and tumour markers makes the pre-operative diagnosis very difficult. A 54 year-old man with no history of exposure to asbestos presented with a short history of scrotal swelling and pain. Ultrasound revealed a suspicious nodularity involving his tunica vaginalis, suggestive of mesothelioma. Excisional biopsy revealed a malignant mesothelioma; hence the patient was treated with radical inguinal orchidectomy and hemiscrotectomy. We present a case of this rare tumour, its management and a review of the literature.

Glycogen synthase kinase-3beta inhibition attenuates the development of bleomycin-induced lung injury

Glycogen synthase kinase-3 (GSK-3) is an ubiquitous serine-threonine protein kinase that participates in a multitude of cellular processes and has recently been implicated in the pathophysiology of a number of diseases. The aim of this study is to investigate the effects of TDZD-8, a potent and selective GSK-3beta inhibitor, on the development of lung injury caused by administration of bleomycin (BLM). Mice subjected to intra-tracheal administration of BLM developed significant lung injury characterized by marked neutrophil infiltration and tissue edema. An increase in immunoreactivity to nitrotyrosine, iNOS, TNF-alpha and IL-1beta was also observed in the lungs of BLM-treated mice. In contrast, administration of BLM-treated mice with TDZD-8 (1 mg/kg daily) significantly reduced (I) the degree of lung injury, (II) the increase in staining (immunohistochemistry) for myeloperoxidase (MPO), nitrotyrosine, iNOS, TNF-alpha and IL-1beta and (III) the degree of apoptosis, as evaluated by Bax and Bcl-2 immunoreactivity and TUNEL staining. Taken together, these results clearly demonstrate treatment with the GSK-3beta inhibitor TDZD-8 reduces the development of lung injury and inflammation induced by BLM in mice.

Inhibition of glycogen synthase kinase-3beta attenuates the development of carrageenan-induced lung injury in mice

BACKGROUND AND PURPOSE

Glycogen synthase kinase-3 (GSK-3) is a ubiquitous serine-threonine protein kinase that participates in a multitude of cellular processes and has recently been implicated in the pathophysiology of a number of diseases. The aim of this study was to investigate the effects of GSK-3beta inhibition in a model of acute inflammation. Here, we have investigated the effects of TDZD-8, a potent and selective GSK-3beta inhibitor, in a mouse model of carrageenan-induced pleurisy.

EXPERIMENTAL APPROACH

Injection of carrageenan into the pleural cavity of mice elicited an acute inflammatory response characterized by: accumulation of fluid containing a large number of neutrophils (PMNs) in the pleural cavity, infiltration of PMNs in lung tissues and subsequent lipid peroxidation, and increased production of nitrite/nitrate (NOx), prostaglandin E2 (PGE2), tumour necrosis factor-alpha, (TNF-alpha) and interleukin-1beta (IL-1beta). Furthermore, carrageenan induced an upregulation of the adhesion molecules ICAM-1 and P-selectin, iNOS, COX-2 as well as nitrotyrosine as determined by immunohistochemical analysis of lung tissues.

KEY RESULTS

Administration of TDZD-8 (1, 3 or 10 mg kg(-1), i.p.), 30 min prior to injection of carrageenan, caused a dose-dependent reduction in all the parameters of inflammation measured.

CONCLUSIONS AND IMPLICATIONS

Thus, based on these findings we propose that inhibitors of the activity of GSK-3beta, such as TDZD-8, may be useful in the treatment of various inflammatory diseases.

Atypical presentation of Churg-Strauss syndrome: another "forme fruste" of the disease?

Vasculitis is a clinicopathologic process characterized by inflammation and damage to blood vessels. A broad and heterogenous group of syndromes may result from this process, because any type, size, and location of blood vessel may be involved. The cause of these conditions remains unclear, but an autoimmune inflammatory process, characterized by involvement of both neutrophils and endothelial cells, seems to play an important role. In 1951, Churg and Strauss described a clinical syndrome of severe asthma, hypereosinophilia with eosinophilic infiltrates, eosinophilic vasculitis, and granulomata in various organs. Asthma may precede this vasculitis by many years. We report a case of anti-neutrophil cytoplasmic antibody-positive, pauci-immune, crescentic, necrotizing glomerulonephritis with peripheral and interstitial eosinophilia but without asthma. This is very unusual in Churg-Strauss syndrome.

Recurrent acute renal failure in a patient with minimal change disease

We report on a 16-year old female patient with biopsy proved minimal change disease and steroid state. She was subsequentlygiven cyclosporin for varying periods of time with inadequate response. She developed four episodes of acute renal failure in the background of severe nephrotic state, 10 years after the onset of her illness. Three of these episodes could be reversed with albumin infusion and judicious use of diuretics while the fourth necessitated six sessions of ultrafiltration. In none of the episodes of ARF could we find any cause other than the nephrotic state itself.

Calpain inhibitor I reduces the activation of nuclear factor-kappaB and organ injury/dysfunction in hemorrhagic shock

There is limited evidence that inhibition of the activity of the cytosolic cysteine protease calpain reduces ischemia/reperfusion injury. The multiple organ injury associated with hemorrhagic shock is due at least in part to ischemia (during hemorrhage) and reperfusion (during resuscitation) of target organs. Here we investigate the effects of calpain inhibitor I on the organ injury (kidney, liver, pancreas, lung, intestine) and dysfunction (kidney) associated with hemorrhagic shock in the anesthetized rat. Hemorrhage and resuscitation with shed blood resulted in an increase in calpain activity (heart), activation of NF-kappaB (kidney), expression of iNOS and COX-2 (kidney), and the development of multiple organ injury and dysfunction, all of which were attenuated by calpain inhibitor I (10 mg/kg i.p.), administered 30 min prior to hemorrhage. Chymostatin, a serine protease inhibitor that does not prevent the activation of NF-kappaB, had no effect on the organ injury/failure caused by hemorrhagic shock. Pretreatment (for 1 h) of murine macrophages or rat aortic smooth muscle cells (activated with endotoxin) with calpain inhibitor I attenuated the binding of activated NF-kappaB to DNA and the degradation of IkappaBalpha, IkappaBbeta, and IkappaBvarepsilon. Selective inhibition of iNOS activity with L-NIL reduced the circulatory failure and liver injury, while selective inhibition of COX-2 activity with SC58635 reduced the renal dysfunction and liver injury caused by hemorrhagic shock. Thus, we provide evidence that the mechanisms by which calpain inhibitor I reduces the circulatory failure as well as the organ injury and dysfunction in hemorrhagic shock include 1) inhibition of calpain activity, 2) inhibition of the activation of NF-kappaB and thus prevention of the expression of NFkappaB-dependent genes, 3) prevention of the expression of iNOS, and 4) prevention of the expression of COX-2. Inhibition of calpain activity may represent a novel therapeutic approach for the therapy of hemorrhagic shock.

A methodology for development of configurable remote access measurement system

A configurable remote access measurement system (CRAMS) is designed using an object oriented methodology (OOM) and implemented using the integration of an object oriented language, JAVA, a relational database management system, MS-ACCESS, and an instrumentation software package (LabVIEW). OOM is a powerful technique that is used to manage the complexity of large systems. It allows for easy maintenance and upgrading of the developed systems. The main focus of this paper is to present a detailed procedure for the analysis, design and implementation of CRAMS. The functionality of CRAMS is demonstrated by creating a remotely accessible laboratory environment using a set of programmable and virtual instruments connected to a PC server.