Anxiety and depression following critical illness: A comparison of the recovery trajectories of patients and caregivers.

BACKGROUND: Following critical illness, family members are often required to adopt caregiving responsibilities. Anxiety and depression are common long term problems for both patients and caregivers. However, at present, it is not known how the trajectories of these symptoms compare between patients and caregivers. OBJECTIVES: The aim of this study was to investigate and compare the trajectories of anxiety and depression in patients and caregivers in the first year following critical illness. METHODS: This study analyses data from a prospective multicentre cohort study of patients and caregivers who underwent a complex recovery intervention following critical illness. Paired patients and caregivers were recruited. The Hospital Anxiety and Depression Scale was used to evaluate symptoms of anxiety and depression at three timepoints: baseline; 3 months; and 12 months in both patient and caregivers. A linear mixed-effects regression model was used to evaluate the trajectories of these symptoms over the first year following critical illness. RESULTS: 115 paired patients and caregivers, who received the complex recovery intervention, were recruited. There was no significant difference in the relative trajectory of depressive symptoms between patients and caregivers in the first 12 months following critical illness (p = 0.08). There was, however, a significant difference in the trajectory of anxiety symptoms between patients and caregivers during this time period (p = 0.04), with caregivers seeing reduced resolution of symptoms in comparison to patients. CONCLUSIONS: Following critical illness, symptoms of anxiety and depression are common in both patients and caregivers. The trajectory of symptoms of depression was similar between caregivers and patients; however, there was a significantly different recovery trajectory in symptoms of anxiety. Further research is required to understand the recovery pathway of caregivers in order to design effective interventions.

Trajectory of Recovery following ORIF for Distal Radius Fractures.

Background Distal radius fractures are commonly seen among the elderly, though studies examining their long-term outcomes are limited. Purpose The aim of this study was to describe the 5-year trajectory of recovery of distal radius fractures treated with open reduction and internal fixation (ORIF). Methods Patients with distal radius fractures (AO/OTA 23.A-C) treated by ORIF were prospectively studied. Patient-Rated Wrist Evaluation (PRWE) score was measured at baseline (preinjury recall) and postoperatively at 6 months, 1 year, and 5 years. Clinically relevant change in PRWE score was assessed using the minimal clinically important difference (MCID). Results A total of 390 patients were included, of which 75% completed 5-year follow-up. Mean baseline PRWE score was 1.25 (standard deviation, SD: 2.9). At 6 months, mean PRWE score was at its highest up to 20.2 (SD: 18.4; p < 0.01). A significant improvement in mean PRWE score was observed at 1 year down to 15.2 (SD: 17.6; p < 0.01); 44% of patients were still one MCID outside of their baseline PRWE score at 1 year. Further significant improvement in mean PRWE score occurred at 5 years down to 9.4 (SD: 13.4; p < 0.01); 29% of patients remained one MCID outside of their baseline PRWE score at 5 years. Conclusion Recovery after ORIF for distal radius fractures showed significant worsening after surgery, followed by significant improvements up to 1 year and between years 1 and 5, albeit to a lesser extent. Statistically and clinically relevant wrist pain and disability persisted at 5 years. Future research should examine different treatment modalities and include a nonoperative treatment arm for comparison. Level of Evidence Prognostic level II.

Considerations for the Identification and Conveyance of Clinical Pathology Findings in Preclinical Toxicity Studies: Results From the 9th ESTP International Expert Workshop.

The European Society of Toxicologic Pathology (ESTP) organized a panel of 24 international experts from many fields of toxicologic clinical pathology (e.g., industry, academia, and regulatory) that came together in 2021 to align the use of terminology to convey the importance of clinical pathology findings in preclinical toxicity studies. An additional goal consisted of how to identify important findings in standard and nonstandard clinical pathology associated endpoints. This manuscript summarizes the information and opinions discussed and shared at the ninth ESTP International Expert Workshop, April 5 to 6, 2022. In addition to terminology usage, the workshop considered topics related to the identification and conveyance of the importance of test item-related findings. These topics included sources of variability, comparators, statistics, reporting, correlations to other study data, nonstandard biomarkers, indirect/secondary findings, and an overall weight-of-evidence approach.

Correction: Integrated silicon photonic MEMS.

[This corrects the article DOI: 10.1038/s41378-023-00498-z.].

Multiplexed experimental strategies for fragment library screening against challenging drug targets using SPR biosensors.

Surface plasmon resonance (SPR) biosensor methods are ideally suited for fragment-based lead discovery.  However, generally applicable experimental procedures and detailed protocols are lacking, especially for structurally or physico-chemically challenging targets or when tool compounds are not available. Success depends on accounting for the features of both the target and the chemical library, purposely designing screening experiments for identification and validation of hits with desired specificity and mode-of-action, and availability of orthogonal methods capable of confirming fragment hits. The range of targets and libraries amenable to an SPR biosensor-based approach for identifying hits is considerably expanded by adopting multiplexed strategies, using multiple complementary surfaces or experimental conditions. Here we illustrate principles and multiplexed approaches for using flow-based SPR biosensor systems for screening fragment libraries of different sizes (90 and 1056 compounds) against a selection of challenging targets. It shows strategies for the identification of fragments interacting with 1) large and structurally dynamic targets, represented by acetyl choline binding protein (AChBP), a Cys-loop receptor ligand gated ion channel homologue, 2) targets in multi protein complexes, represented by lysine demethylase 1 and a corepressor (LSD1/CoREST), 3) structurally variable or unstable targets, represented by farnesyl pyrophosphate synthase (FPPS), 4) targets containing intrinsically disordered regions, represented by protein tyrosine phosphatase 1B  (PTP1B), and 5) aggregation-prone proteins, represented by an engineered form of human tau  (tau K18M). Practical considerations and procedures accounting for the characteristics of the proteins and libraries, and that increase robustness, sensitivity, throughput and versatility are highlighted. The study shows that the challenges for addressing these types of targets is not identification of potentially useful fragments per se, but establishing methods for their validation and evolution into leads.

α-Functionalisation of Cyclic Sulfides Enabled by Lithiation Trapping.

A general and straightforward procedure for the lithiation trapping of cyclic sulfides such as tetrahydrothiophene, tetrahydrothiopyran and a thiomorpholine is described. Trapping with a wide range of electrophiles is demonstrated, leading to more than 50 diverse α-substituted saturated sulfur heterocycles. The methodology provides access to a range of α-substituted cyclic sulfides that are not easily synthesised by the currently available methods.

Temperate silvopastures provide greater ecosystem services than conventional pasture systems.

Management and design affect systems' ability to deliver ecosystem services and meet sustainable intensification needs for a growing population. Soil-plant-animal health evaluations at the systems level for conventional and silvopastoral environments are lacking and challenge adoption across temperate regions. Impacts of silvopasture on soil quality, microclimate, cattle heat stress, forage quality and yield, and cattle weight gain were compared to a conventional pasture in the mid-southern US. Here, we illustrate silvopastures have greater soil organic carbon, water content, and overall quality, with lower temperatures (soil and cattle) than conventional pastures. Forage production and cattle weight gains were similar across systems; yet, conventional pasture systems would need approximately four times more land area to yield equivalent net productivity (tree, nuts, forage, and animal weight) of one ha of silvopasture. Temperate silvopastures enhanced delivery of ecosystem services by improving soil quality and promoting animal welfare without productivity losses, thus allowing sustainable production under a changing climate.

The relationship between pain, anxiety and depression in patients with post-intensive care syndrome.

PURPOSE: Survivors of critical illness frequently experience long-term symptoms including physical symptoms such as pain and emotional symptoms such as anxiety and depression. These symptoms frequently co-exist, however, at present there is limited understanding of these relationships. The aim of this study was to quantify the relationship between pain, anxiety and depression across the recovery trajectory. METHODS: This study is a secondary analysis of data from a multi-centre, prospective, cohort study which followed-up patients recovering from critical illness. Data was available at multiple time points and for 3 distinct cohorts. Structural equation modelling was used to investigate the relationship between outcome measures of pain, anxiety and depression. RESULTS: Data from 414 patients was analysed. Pain was significantly associated with both anxiety and depression in all cohorts and at all time points sampled. Path coefficients for the covariances between pain and depression ranged between 0.39 and 0.72 (p < 0.01). Path coefficients for the covariances between pain and anxiety ranged between 0.39 and 0.65 (p < 0.01). CONCLUSIONS: Pain, anxiety and depression are highly correlated in survivors of critical illness. Pharmacological treatments for pain management may be ineffective alone and further research is required to assess interventions targeting these symptoms in combination.

Assessing the Change in Operative Treatment Rates for Acute Midshaft Clavicle Fractures: Incorporation of Evidence-Based Surgery Results in Orthopaedic Practice.

In 2007, a randomized controlled trial (RCT) by the Canadian Orthopaedic Trauma Society (COTS) demonstrated better functional outcomes and a lower proportion of patients who developed malunion or nonunion following operative, compared with nonoperative, treatment of midshaft clavicle fractures. The primary aim of the present study was to compare the proportion of midshaft clavicle fractures treated operatively prior to and following the publication of the COTS RCT. An additional exploratory aim was to assess whether the proportion of midshaft clavicle fractures that were treated with surgery for malunion or nonunion decreased. Methods: This retrospective cohort analysis used population-level administrative health data on the residents of British Columbia, Canada. Cases were identified by International Classification of Diseases, Ninth Revision (ICD-9) diagnostic codes and procedure fee codes. Adult patients (≥18 years) with closed middle-third clavicle fractures between 1997 and 2018 were included. Multivariable logistic regression modeling compared the proportion of clavicle fractures treated operatively before and after January 1, 2007, controlling for patient factors. The Pearson chi-square test compared the proportion of fractures treated operatively for malunion or nonunion in the cohorts. Results: A total of 52,916 patients were included (mean age, 47.5 years; 65.6% male). More clavicle fractures were treated operatively from 2007 onward: 6.9% compared with 2.2% prior to 2007 (odds ratio [OR] = 3.35, 95% confidence interval [CI] = 3.03 to 3.70, p < 0.001). Male sex, moderate-to-high income, and younger age were associated with a greater proportion of operative fixation. The rate of surgery for clavicle malunion or nonunion also increased over this time period (to 4.1% from 3.4%, OR = 1.26, 95% CI = 1.15 to 1.38, p < 0.001). Conclusions: We found a significant change in surgeon practice regarding operative management of clavicle fractures following the publication of a Level-I RCT. With limited high-quality trials comparing operative and nonoperative management, it is important that clinicians, health-care institutions, and health-authority administrations determine what steps can be taken to increase responsiveness to new clinical studies and evidence-based guidelines. Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Integrated silicon photonic MEMS.

Silicon photonics has emerged as a mature technology that is expected to play a key role in critical emerging applications, including very high data rate optical communications, distance sensing for autonomous vehicles, photonic-accelerated computing, and quantum information processing. The success of silicon photonics has been enabled by the unique combination of performance, high yield, and high-volume capacity that can only be achieved by standardizing manufacturing technology. Today, standardized silicon photonics technology platforms implemented by foundries provide access to optimized library components, including low-loss optical routing, fast modulation, continuous tuning, high-speed germanium photodiodes, and high-efficiency optical and electrical interfaces. However, silicon's relatively weak electro-optic effects result in modulators with a significant footprint and thermo-optic tuning devices that require high power consumption, which are substantial impediments for very large-scale integration in silicon photonics. Microelectromechanical systems (MEMS) technology can enhance silicon photonics with building blocks that are compact, low-loss, broadband, fast and require very low power consumption. Here, we introduce a silicon photonic MEMS platform consisting of high-performance nano-opto-electromechanical devices fully integrated alongside standard silicon photonics foundry components, with wafer-level sealing for long-term reliability, flip-chip bonding to redistribution interposers, and fibre-array attachment for high port count optical and electrical interfacing. Our experimental demonstration of fundamental silicon photonic MEMS circuit elements, including power couplers, phase shifters and wavelength-division multiplexing devices using standardized technology lifts previous impediments to enable scaling to very large photonic integrated circuits for applications in telecommunications, neuromorphic computing, sensing, programmable photonics, and quantum computing.

Organogel delivery vehicles for the stabilization of organolithium reagents.

Organolithium reagents are a vital tool in modern organic chemistry, enabling the synthesis of carbon-carbon bonds. However, due to their high reactivity, low temperatures, inert atmospheres and strictly dried solvents are usually necessary for their use. Here we report an encapsulating method for the stabilization of sensitive organolithium reagents-PhLi, n-BuLi and s-BuLi-in a low-cost hexatriacontane (C36H74) organogel. The use of this technology is showcased in nucleophilic addition reactions under ambient conditions, low-temperature bromine-lithium exchange, ortho-lithiation and C-H functionalization. The gel substantially enhances organolithium stability, allows simple storage, handling and delivery, and enables reproducible reagent portioning. The use of gels as easily divided delivery vehicles for hazardous organometallics has the potential to transform this area of synthetic chemistry, making these powerful reactions safer and more accessible to non-specialist researchers, and enabling the more widespread use of these common synthetic methods.

Evaluating pain in survivors of critical illness: the correlation between the EQ-5D-5L and the Brief Pain Inventory.

INTRODUCTION: Pain is a common and debilitating symptom in survivors of critical illness. The 'Core Outcome Set for Survivors of Acute Respiratory Failure' proposes that the pain and discomfort question of the EuroQol 5 Dimension 5 Level (EQ-5D-5L) could be used to assess pain in this group, however, it was recognised that further research is required to evaluate how this single question compares to other more detailed pain tools. This study aims to evaluate the relationship between the pain and discomfort question of the EQ-5D-5L and the Brief Pain Inventory (BPI) in survivors of critical illness. METHODS: This study retrospectively analysed paired EQ-5D-5L and BPI data extracted from a prospective, multicentre study evaluating the impact of a critical care recovery programme. 172 patients who received a complex recovery intervention and 108 patients who did not receive this intervention were included. Data were available for the intervention cohort at multiple time points, namely, baseline, 3 months and 12 months. While, data were available for the usual care cohort at a single time point (12 months). We assessed the correlation between the pain and discomfort question of the EQ-5D-5L and two separate components of the BPI: severity of pain and pain interference. RESULTS: Correlation coefficients comparing the pain and discomfort question of the EQ-5D-5L and the BPI pain severity score ranged between 0.73 (95% CI 0.63 to 0.80) and 0.80 (95% CI 0.72 to 0.86). Correlation coefficients comparing the pain and discomfort question of the EQ-5D-5L and the BPI pain interference score ranged between 0.71 (95% CI 0.62 to 0.79) and 0.83 (95% CI 0.76 to 0.88) across the various time points. CONCLUSIONS: The pain and discomfort question of the EQ-5D-5L correlates moderately well with a more detailed pain tool and may help to streamline assessments in survivorship studies. More in-depth tools may be of use where pain is the primary study outcome or a patient-reported concern.

Evaluation of a health and social care programme to improve outcomes following critical illness: a multicentre study.

RATIONALE: At present, clinicians aiming to support patients through the challenges after critical care have limited evidence to base interventions. OBJECTIVES: Evaluate a multicentre integrated health and social care intervention for critical care survivors. A process evaluation assessed factors influencing the programme implementation. METHODS: This study evaluated the impact of the Intensive Care Syndrome: Promoting Independence and Return to Employment (InS:PIRE) programme. We compared patients who attended this programme with a usual care cohort from the same time period across nine hospital sites in Scotland. The primary outcome was health-related quality of life (HRQoL) measured via the EuroQol 5-dimension 5-level instrument, at 12 months post hospital discharge. Secondary outcome measures included self-efficacy, depression, anxiety and pain. RESULTS: 137 patients who received the InS:PIRE intervention completed outcome measures at 12 months. In the usual care cohort, 115 patients completed the measures. The two cohorts had similar baseline demographics. After adjustment, there was a significant absolute increase in HRQoL in the intervention cohort in relation to the usual care cohort (0.12, 95% CI 0.04 to 0.20, p=0.01). Patients in the InS:PIRE cohort also reported self-efficacy scores that were 7.7% higher (2.32 points higher, 95% CI 0.32 to 4.31, p=0.02), fewer symptoms of depression (OR 0.38, 95% CI 0.19 to 0.76, p=0.01) and similar symptoms of anxiety (OR 0.58, 95% CI 0.30 to 1.13, p=0.11). There was no significant difference in overall pain experience. Key facilitators for implementation were: integration with inpatient care, organisational engagement, flexibility to service inclusion; key barriers were: funding, staff availability and venue availability. CONCLUSIONS: This multicentre evaluation of a health and social care programme designed for survivors of critical illness appears to show benefit at 12 months following hospital discharge.

Exploration of piperidine 3D fragment chemical space: synthesis and 3D shape analysis of fragments derived from 20 regio- and diastereoisomers of methyl substituted pipecolinates.

Fragment-based drug discovery is now widely adopted for lead generation in the pharmaceutical industry. However, fragment screening collections are often predominantly populated with flat, 2D molecules. Herein, we report the synthesis of piperidine-based 3D fragment building blocks - 20 regio- and diastereoisomers of methyl substituted pipecolinates using simple and general synthetic methods. cis-Piperidines, accessed through a pyridine hydrogenation were transformed into their trans-diastereoisomers using conformational control and unified reaction conditions. Additionally, diastereoselective lithiation/trapping was utilised to access trans-piperidines. Analysis of a virtual library of fragments derived from the 20 cis- and trans-disubstituted piperidines showed that it consisted of 3D molecules with suitable molecular properties to be used in fragment-based drug discovery programs.

Radiation doses and fractionation schedules in non-low-risk ductal carcinoma in situ in the breast (BIG 3-07/TROG 07.01): a randomised, factorial, multicentre, open-label, phase 3 study.

BACKGROUND: Whole breast irradiation (WBI) after conservative surgery for ductal carcinoma in situ (DCIS) reduces local recurrence. We investigated whether a tumour bed boost after WBI improved outcomes, and examined radiation dose fractionation sensitivity for non-low-risk DCIS. METHODS: The study was an international, randomised, unmasked, phase 3 trial involving 136 participating centres of six clinical trials organisations in 11 countries (Australia, New Zealand, Singapore, Canada, the Netherlands, Belgium, France, Switzerland, Italy, Ireland, and the UK). Eligible patients were women aged 18 years or older with unilateral, histologically proven, non-low-risk DCIS treated by breast-conserving surgery with at least 1 mm of clear radial resection margins. They were assigned to one of four groups (1:1:1:1) of no tumour bed boost versus boost after conventional versus hypofractionated WBI, or randomly assigned to one of two groups (1:1) of no boost versus boost after each centre prespecified conventional or hypofractionated WBI. The conventional WBI used was 50 Gy in 25 fractions, and hypofractionated WBI was 42·5 Gy in 16 fractions. A boost dose of 16 Gy in eight fractions, if allocated, was delivered after WBI. Patients and clinicians were not masked to treatment allocation. The primary endpoint was time to local recurrence. This trial is registered with ClinicalTrials.gov (NCT00470236). FINDINGS: Between June 25, 2007, and June 30, 2014, 1608 patients were randomly assigned to have no boost (805 patients) or boost (803 patients). Conventional WBI was given to 831 patients, and hypofractionated WBI was given to 777 patients. Median follow-up was 6·6 years. The 5-year free-from-local-recurrence rates were 92·7% (95% CI 90·6-94·4%) in the no-boost group and 97·1% (95·6-98·1%) in the boost group (hazard ratio 0·47; 0·31-0·72; p<0·001). The boost group had higher rates of grade 2 or higher breast pain (10% [8-12%] vs 14% [12-17%], p=0·003) and induration (6% [5-8%] vs 14% [11-16%], p<0·001). INTERPRETATION: In patients with resected non-low-risk DCIS, a tumour bed boost after WBI reduced local recurrence with an increase in grade 2 or greater toxicity. The results provide the first randomised trial data to support the use of boost radiation after postoperative WBI in these patients to improve local control. The international scale of the study supports the generalisability of the results. FUNDING: National Health and Medical Research Council of Australia, Susan G Komen for the Cure, Breast Cancer Now, OncoSuisse, Dutch Cancer Society, Canadian Cancer Trials Group.

Escape from planarity in fragment-based drug discovery: A synthetic strategy analysis of synthetic 3D fragment libraries.

In fragment-based drug discovery (FBDD), there is a developing appreciation that 3D fragments could offer opportunities that are not provided by 2D fragments. This review provides an overview of the synthetic strategies that have been used to prepare 3D fragments, as discussed in 25 papers published from 2011 to mid-May 2020. Three distinct strategies are highlighted: (i) diversity-oriented synthesis; (ii) the synthesis and diversification of scaffolds; and (iii) computational design and synthesis (where 3D fragments were computationally enumerated and filtered on the basis of computationally generated 3D shape descriptors and other properties). We conclude that a workflow that combines computational design and one other strategy, together with a consideration of fragment properties, 3D shape and 'fragment sociability', could allow 3D fragments to feature more widely in fragment libraries and could facilitate fragment-to-lead optimisation.

Preliminary efficacy and safety analysis: 12-month results in 83 patients using a novel approach of widefield radiation therapy for extensive skin field cancerization with or without keratinocyte cancers.

PURPOSE: Evaluate the use of widefield radiation therapy (RT) in the management of extensive skin field cancerization (ESFC) with/without keratinocyte cancer (KC). METHODS: The National Dermatology Radiation Oncology Registry is a multidisciplinary collaboration (dermatologists and radiation oncologists). It captures disease description, prior therapies, radiation prescription, clinical effect, skin cosmesis scores, and toxicity data. This analysis included 12-month follow-up data on 89 treated fields from a subset of 83 patients. RESULTS: Clinical success (>90% field clearance) was 96% (ESFC, n = 63) and 88% (ESFC with KC, n = 26). Complete lesion response was seen in 96% of evaluable (n = 25) ESFC with KC. Recurrence (4/89 [5%]) and appearance of new lesions (10/89 [11%]) were minimal. Cosmetic outcome was excellent/good in 98% ESFC and 96% ESFC with KC. Grade 1-2 acute radiation dermatitis occurred in up to 80% of treated fields. The frequency of Grade 3 acute skin toxicities was low. CONCLUSIONS: Registry data demonstrate the potential for widefield RT to treat patients with significant skin pathology who have exhausted other therapies and require durable, minimally invasive treatment options. At 12 months, observed clinical success rates were higher than those reported for topical interventions for ESFC. Ongoing follow-up is required to determine longer term outcomes.

Nitrate losses and nitrous oxide emissions under contrasting tillage and cover crop management.

Agroecosystems in the upper Mississippi River Basin are highly productive but often contribute to deterioration of water quality and greenhouse gas emissions. Cover cropping and no-till are conservation strategies implemented to reduce the environmental impact of these agroecosystems. However, using multiple strategies can lead to systemwide interactions that are not fully understood. These interactions can affect not only environmental quality metrics, such as subsurface drainage nitrate losses or nitrous oxide (N2 O) emissions, but also may influence crop production potential. A field trial was initiated comparing nitrate losses, N2 O emissions, and crop production under systems with fall chisel plow tillage, fall chisel plow tillage with an oat (Avena sativa L.) cover crop (CP-oat), no-till (NT), no-till with a rye (Secale cereale L.) cover crop (NT-rye), and NT with zero N fertilizer. Pathways for nitrate losses and N2 O emissions did not appear linked and were not tied to cover crop or tillage practices. Nitrate losses were linked with drainage volumes, and cover crops and tillage had limited effect on cumulative drainage volumes. Notably, NT-rye altered the relationship between drainage volume and nitrate losses by reducing nitrate concentrations, lowering nitrate losses by 59 ±9% compared with CP-oat and 67 ± 9% compared with NT. Neither cover crop nor tillage consistently affected N2 O emissions or crop yield. Rather, N2 O emissions were closely tied with fertilizer N application and seasonal weather patterns. These findings indicate that nitrate leaching and N2 O emissions are regulated by separate mechanisms, so conservation management may require stacking multiple practices to be effective.

Both subsurface nitrate losses and nitrous oxide emissions were linked with weather. Subsurface nitrate losses were linked with cumulative annual drainage. Nitrous oxide emissions were linked with fertilizer N applications. Rye cover crop with no-till reduced nitrate losses with no yield declines.

Use of intraoperative impression smear cytology to guide successful treatment of a large renal cyst in a dog: a case report.

A 13-yr-old Shih tzu was referred for surgical management of right-sided cranial abdominal mass, which corresponded to large, cavitated renal mass on ultrasonography, and was suspected to represent neoplasia. Intraoperative impression smear cytology (ISC) of the renal mass wall was consistent with benign renal cyst (RC), without evidence of neoplasia or infection. Deroofing and omentalisation were performed and histopathology was consistent with benign RC. Chronic kidney disease was diagnosed 4 mon postoperatively, however, the dog was asymptomatic, without cyst reoccurrence. Intraoperative ISC is an expedient and inexpensive diagnostic technique that can guide most appropriate treatment in dogs with large RCs.