The Application of Infrared Imaging and Optical Coherence Tomography of the Lacrimal Punctum in Patients Undergoing Punctoplasty for Epiphora

Purpose To determine the application of imaging the stenotic lacrimal punctum with infrared photographs and optical coherence tomography (OCT) and to identify characteristics of the lacrimal punctum in patients who benefit from punctoplasty. Design Case-control study. Participants Twenty patients with epiphora who were listed for punctoplasty and 20 healthy controls. Methods Prospectively, 20 patients listed for punctoplasty were asked to rate their epiphora, using the Munk score, before and after punctoplasty. They also underwent preoperative OCT and infrared imaging of the affected punctum. They were divided into 2 groups, depending on whether the epiphora improved, and were compared with 20 healthy controls. Main Outcome Measures Measurements of puncta from infrared and OCT images were obtained along with Munk scores of patient epiphora. Results The infrared image measurements were significantly smaller in those patients whose epiphora improved compared with those whose did not in both the area of the punctal aperture and in the maximum punctal diameter. Additionally, those patients with improvement in epiphora had a significantly smaller preoperative punctal diameter at 100 μm depth on OCT compared with healthy controls; this was not observed in patients whose epiphora failed to improve. There was no significant difference in the punctum diameter among the 3 groups at the punctum surface entrance or at 500 μm depth. Patients with epiphora had a higher tear meniscus within the punctum compared with healthy controls. Conclusions Lacrimal punctum infrared and OCT imaging may be helpful in predicting patients more likely to benefit symptomatically from punctoplasty, with patients with smaller puncta having greater symptomatic improvement. However, the results suggest that inner punctum diameter (not readily measurable by slit-lamp examination), rather than the surface diameter, is correlated with outcome. Additionally, OCT measurements of the tear meniscus height within the punctum may be related to the degree of epiphora

Characterizing the Occluded Lacrimal Punctum Using Anterior Segment Optical Coherence Tomography.

PURPOSE: Epiphora is sometimes associated with an absent or occluded lacrimal drainage punctum (or puncta). This study uses noninvasive "enhanced depth" anterior segment optical coherence tomography (OCT) to give improved characterization and understanding of absent or fully occluded puncta and the underlying canaliculus. METHODS: Anterior segment spectral domain OCT images were collected prospectively from 9 lower puncta of 6 patients with epiphora and absent or fully occluded puncta, not amenable to dilation in clinic, to see if a canaliculus was visible on OCT imaging below the occluded punctum. RESULTS: An epithelial lined canalicular lumen was visible on OCT in 4 lower eyelid puncta from 2 patients and OCT identified 80% (4/5) of the canaliculi that were located on microscope-assisted punctal exploration. These lumens were seen within 580 μm depth from the eyelid margin surface. A half of the eyes in which a canaliculus was identified on OCT (the 2 eyes in a single patient) had resolution of epiphora following punctoplasty, and the other patient was found to have coexisting nasolacrimal duct stenosis and required later dacryocystorhinostomy. The positive predictive value for identifying a canaliculus on lower eyelid punctal exploration in acquired complete punctal occlusion (excluding the congenital case) was 1, with a negative predictive value of 1. CONCLUSIONS: This study demonstrates that canaliculi can be imaged with OCT where formal access is precluded by an occluded punctum. This noninvasive investigation might help predict the likelihood of successful retrieval of a canaliculus at surgical exploration

Pericardial Effusion Worm-Like Strands on Transthoracic Echocardiogram

Background: Fibrinous Pericardial Effusion is the accumulation of excess fluid in the pericardial fibroelastic sac. It can be a symptom of any pathological process that affects the pericardium from acute pericarditis to systemic disorders. This broad differential poses a diagnostic challenge in the setting of acute fluid accumulation. Case Presentation: A 50-year-old male with a past medical history of extensive intravenous drug use complicated by bacteremia and left ankle abscess formation presented to the Emergency Department complaining of mild-moderate chest pain for four days. Within the last month, he presented to the Emergency Department three times for similar symptoms; however, he eloped each time before receiving proper medical treatment. Chest x-ray revealed an enlarged cardiac silhouette, and follow-up computed tomography (CT) scan demonstrated a large transudative pericardial effusion, bilateral lower lobe consolidation, and retroperitoneal lymphadenopathy. Prior to pericardiocentesis, a transthoracic echocardiogram was performed that revealed intrapericardial adhesions with a larva-like appearance. His clinical course was complicated by a concurrent left ankle abscess managed by podiatry. He received a pericardial window procedure one week later. Blood cultures from both procedures were negative, and the etiology was determined to be idiopathic. Subsequently, the cardiothoracic surgery team signed the patient off to the primary medical team for further medical management. Discussion/Conclusions: This case illustrates that imaging results can create a disproportionately severe clinical picture. Additionally, even in the case of explained systemic disease, the idiopathic nature of this patient presentation complicates the post-pericardiocentesis management of this patient. The extent of intrapericardial adhesion density and clinically severe appearance is not indicative of a pericardial effusion’s etiology. Transthoracic echocardiogram alone does not have a significant role in the formulation of a differential diagnosis for the treatment of fibrinous pericardial effusion

Effects of Laser Source Parameters on the Generation of Narrow Band and Directed Laser Ultrasound

The successful application of laser techniques for ultrasonic testing depends on the efficient coupling of optical energy into elastic energy so that laser probe detection sensitivity may be maximized. Through optimization of the laser source which is used to generate ultrasonic waves, the overall performance of laser ultrasonic systems may be enhanced by improving the efficiency with which optical energy is converted to elastic energy. This optimization depends primarily on the source laser wavelength which governs the physical interaction of the optical energy with the material of interest. For a given laser source wavelength, several techniques have been demonstrated which modify the laser source to enhance the detectability of laser ultrasonic waves and include the repetitively pulsed laser source [1,2], or temporal array, and the phased array laser source [3],or phased array. These techniques directly address the wave detectability issue by controlling the amplitude and/or the frequency content of the laser ultrasonic wave. Even though the overall conversion efficiency of optical energy to elastic energy is not improved primarily by repetitive pulsing or phasing laser arrays, the detectability of a given laser ultrasonic wave may be enhanced beyond that obtained using a single laser source

Effect of Cyclooxygenase(COX)-1 and COX-2 inhibition on furosemide-induced renal responses and isoform immunolocalization in the healthy cat kidney

BACKGROUND: The role of cyclooxygenase(COX)-1 and COX-2 in the saluretic and renin-angiotensin responses to loop diuretics in the cat is unknown. We propose in vivo characterisation of isoform roles in a furosemide model by administering non-steroidal anti-inflammatory drugs (NSAIDs) with differing selectivity profiles: robenacoxib (COX-2 selective) and ketoprofen (COX-1 selective). RESULTS: In this four period crossover study, we compared the effect of four treatments: placebo, robenacoxib once or twice daily and ketoprofen once daily concomitantly with furosemide in seven healthy cats. For each period, urine and blood samples were collected at baseline and within 48 h of treatment starting. Plasma renin activity (PRA), plasma and urinary aldosterone concentrations, glomerular filtration rate (GFR) and 24 h urinary volumes, electrolytes and eicosanoids (PGE(2), 6-keto-PGF1(α,) TxB(2)), renal injury biomarker excretions [N-acetyl-beta-D-glucosaminidase (NAG) and Gamma-Glutamyltransferase] were measured. Urine volume (24 h) and urinary sodium, chloride and calcium excretions increased from baseline with all treatments. Plasma creatinine increased with all treatments except placebo, whereas GFR was significantly decreased from baseline only with ketoprofen. PRA increased significantly with placebo and once daily robenacoxib and the increase was significantly higher with placebo compared to ketoprofen (10.5 ± 4.4 vs 4.9 ± 5.0 ng ml(−1) h(−1)). Urinary aldosterone excretion increased with all treatments but this increase was inhibited by 75 % with ketoprofen and 65 % with once daily robenacoxib compared to placebo. Urinary PGE(2) excretion decreased with all treatments and excretion was significantly lower with ketoprofen compared to placebo. Urinary TxB(2) excretion was significantly increased from baseline only with placebo. NAG increased from baseline with all treatments. Immunohistochemistry on post-mortem renal specimens, obtained from a different group of cats that died naturally of non-renal causes, suggested constitutive COX-1 and COX-2 co-localization in many renal structures including the macula densa (MD). CONCLUSIONS: These data suggest that both COX-1 and COX-2 could generate the signal from the MD to the renin secreting cells in cats exposed to furosemide. Co-localization of COX isoenzymes in MD cells supports the functional data reported here. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12917-015-0598-z) contains supplementary material, which is available to authorized users

Automation in human-machine networks: how increasing machine agency affects human agency

© 2018, Springer International Publishing AG. Efficient human-machine networks require productive interaction between human and machine actors. In this study, we address how a strengthening of machine agency, for example through increasing levels of automation, affect the human actors of the networks. Findings from case studies within air traffic management, emergency management, and crowd evacuation are presented, shedding light on how automation may strengthen the agency of human actors in the network through responsibility sharing and task allocation, and serve as a needed prerequisite of innovation and change

The implausibility of ‘usual care’ in an open system: sedation and weaning practices in Paediatric Intensive Care Units (PICUs) in the United Kingdom (UK)

Background: The power of the randomised controlled trial depends upon its capacity to operate in a closed system whereby the intervention is the only causal force acting upon the experimental group and absent in the control group, permitting a valid assessment of intervention efficacy. Conversely, clinical arenas are open systems where factors relating to context, resources, interpretation and actions of individuals will affect implementation and effectiveness of interventions. Consequently, the comparator (usual care) can be difficult to define and variable in multi-centre trials. Hence outcomes cannot be understood without considering usual care and factors that may affect implementation and impact on the intervention. Methods: Using a fieldwork approach, we describe PICU context, ‘usual’ practice in sedation and weaning from mechanical ventilation, and factors affecting implementation prior to designing a trial involving a sedation and ventilation weaning intervention. We collected data from 23 UK PICUs between June and November 2014 using observation, individual and multi-disciplinary group interviews with staff. Results: Pain and sedation practices were broadly similar in terms of drug usage and assessment tools. Sedation protocols linking assessment to appropriate titration of sedatives and sedation holds were rarely used (9 % and 4 % of PICUs respectively). Ventilator weaning was primarily a medical-led process with 39 % of PICUs engaging senior nurses in the process: weaning protocols were rarely used (9 % of PICUs). Weaning methods were variably based on clinician preference. No formal criteria or use of spontaneous breathing trials were used to test weaning readiness. Seventeen PICUs (74 %) had prior engagement in multi-centre trials, but limited research nurse availability. Barriers to previous trial implementation were intervention complexity, lack of belief in the evidence and inadequate training. Facilitating factors were senior staff buy-in and dedicated research nurse provision. Conclusions: We examined and identified contextual and organisational factors that may impact on the implementation of our intervention. We found usual practice relating to sedation, analgesia and ventilator weaning broadly similar, yet distinctively different from our proposed intervention, providing assurance in our ability to evaluate intervention effects. The data will enable us to develop an implementation plan; considering these factors we can more fully understand their impact on study outcomes

Complementarity of Spike- and Rate-Based Dynamics of Neural Systems

Relationships between spiking-neuron and rate-based approaches to the dynamics of neural assemblies are explored by analyzing a model system that can be treated by both methods, with the rate-based method further averaged over multiple neurons to give a neural-field approach. The system consists of a chain of neurons, each with simple spiking dynamics that has a known rate-based equivalent. The neurons are linked by propagating activity that is described in terms of a spatial interaction strength with temporal delays that reflect distances between neurons; feedback via a separate delay loop is also included because such loops also exist in real brains. These interactions are described using a spatiotemporal coupling function that can carry either spikes or rates to provide coupling between neurons. Numerical simulation of corresponding spike- and rate-based methods with these compatible couplings then allows direct comparison between the dynamics arising from these approaches. The rate-based dynamics can reproduce two different forms of oscillation that are present in the spike-based model: spiking rates of individual neurons and network-induced modulations of spiking rate that occur if network interactions are sufficiently strong. Depending on conditions either mode of oscillation can dominate the spike-based dynamics and in some situations, particularly when the ratio of the frequencies of these two modes is integer or half-integer, the two can both be present and interact with each other

On the early and developed stages of surface condensation: competition mechanism between interfacial and condensate bulk thermal resistances

Financial supports from the National Natural Science Foundation of China (51406205), the Beijing Natural Science Foundation (3142021) and the Engineering and Physics Science Research Council (EPSRC) of the UK (EP/L001233/1) are acknowledged.Financial supports from the National Natural Science Foundation of China (51406205), the Beijing Natural Science Foundation (3142021) and the Engineering and Physics Science Research Council (EPSRC) of the UK (EP/L001233/1) are acknowledged.Financial supports from the National Natural Science Foundation of China (51406205), the Beijing Natural Science Foundation (3142021) and the Engineering and Physics Science Research Council (EPSRC) of the UK (EP/L001233/1) are acknowledged.We use molecular dynamics simulation to investigate the early and developed stages of surface condensation. We find that the liquid-vapor and solid-liquid interfacial thermal resistances depend on the properties of solid and fluid, which are time-independent, while the condensate bulk thermal resistance depends on the condensate thickness, which is time-dependent. There exists intrinsic competition between the interfacial and condensate bulk thermal resistances in timeline and the resultant total thermal resistance determines the condensation intensity for a given vapor-solid temperature difference. We reveal the competition mechanism that the interfacial thermal resistance dominates at the onset of condensation and holds afterwards while the condensate bulk thermal resistance gradually takes over with condensate thickness growing. The weaker the solid-liquid bonding, the later the takeover occurs. This competition mechanism suggests that only when the condensate bulk thermal resistance is reduced after it takes over the domination can the condensation be effectively intensified. We propose a unified theoretical model for the thermal resistance analysis by making dropwise condensation equivalent to filmwise condensation. We further find that near a critical point (contact angle being ca. 153°) the bulk thermal resistance has the least opportunity to take over the domination while away from it the probability increases.Financial supports from the National Natural Science Foundation of China (51406205), the Beijing Natural Science Foundation (3142021) and the Engineering and Physics Science Research Council (EPSRC) of the UK (EP/L001233/1) are acknowledged

Rhomboid family member 2 regulates cytoskeletal stress-associated Keratin 16.

Keratin 16 (K16) is a cytoskeletal scaffolding protein highly expressed at pressure-bearing sites of the mammalian footpad. It can be induced in hyperproliferative states such as wound healing, inflammation and cancer. Here we show that the inactive rhomboid protease RHBDF2 (iRHOM2) regulates thickening of the footpad epidermis through its interaction with K16. K16 expression is absent in the thinned footpads of irhom2-/- mice compared with irhom2+/+mice, due to reduced keratinocyte proliferation. Gain-of-function mutations in iRHOM2 underlie Tylosis with oesophageal cancer (TOC), characterized by palmoplantar thickening, upregulate K16 with robust downregulation of its type II keratin binding partner, K6. By orchestrating the remodelling and turnover of K16, and uncoupling it from K6, iRHOM2 regulates the epithelial response to physical stress. These findings contribute to our understanding of the molecular mechanisms underlying hyperproliferation of the palmoplantar epidermis in both physiological and disease states, and how this 'stress' keratin is regulated