Diagnostic yield of percutaneous, ultrasound-guided, fine needle aspirates of the gastrointestinal wall: a retrospective analysis of 152 samples.

OBJECTIVES: The aim was to assess the technical success of percutaneous ultrasound-guided fine needle aspirates of gastrointestinal wall lesions and evaluate predictors of success. Secondary aims included comparing the cytological diagnosis with histopathology, evaluating the utility of concurrent locoregional lymph node cytology and assessing the procedure's complication rate. MATERIAL AND METHODS: Gastrointestinal wall cytology from 75 dogs and 70 cats obtained between 2018 and 2023 were reviewed and categorised as successful (resulting in a diagnostic cytology report) and accurate (resulting in the correct diagnosis when compared to histopathology). Unsuccessful fine needle aspirates, not submitted for cytology, were not recorded. Variables recorded included animal signalment, lesion and lymph node's appearance on ultrasound, size, location, number of smears submitted and experience of the ultrasonographer. RESULTS: One hundred and fifty-two reports were analysed. Eighty-eight (58%) were successful: three normal epithelium, 21 inflammatory processes and 64 neoplasms. Variables associated with increased technical success included description of a mass, higher number of slides submitted and thickness of gastrointestinal lesion on ultrasound. Comparison with histopathology, performed for 17 lesions, showed discrepancies in eight, complete agreement in seven and partial in two. Eighty-four loco-regional lymph nodes were sampled, of which, 67 were successful (80%) and 52 brought additional clinical information (supporting GI wall cytology or diagnosing neoplasia not identified on GI wall cytology). No complication strictly attributable to gastrointestinal wall sampling was reported but when possibly related, death of the patient occurred in 2.5% of cases. CLINICAL SIGNIFICANCE: Ultrasound-guided fine needle aspirate of gastrointestinal wall had moderate accuracy and was unsuccessful in 42% of cases, but technical success increased when sampling mass lesions, thicker intestinal layers and submitting more slides.

Volumetric metamaterials versus impedance surfaces in scattering applications.

Artificially created media allow employing material parameters as additional valuable degrees of freedom in tailoring electromagnetic scattering. In particular, metamaterials with either negative permeability or permittivity allow creating deeply subwavelength resonant structures with relatively high scattering cross-sections. However, the equivalence principle allows replacing volumetric structures with properly designed curved impedance surfaces, ensuring the same electromagnetic properties. Here, we examine this statement from a practical standpoint, considering two structures, having a dipolar electric resonance at the same frequency. The first realization is based on arrays of inductively loaded electric dipoles printed on stacked circuit boards (a volumetric metamaterial), while the second structure utilizes a 4-wire spiral on a spherical surface (surface impedance realization). An intermediate conclusion is that the surface implementation tends to outperform the volumetric counterparts in the scenario when a single resonance is involved. However, in the case where multiple resonances are overlapping and lossy materials are involved, volumetric realization can have an advantage. The discussed structures are of significant importance to the field of electrically small antennas, superdirective antennas, and superscatterers, which find use in wireless communications and radar applications, to name just a few.

Complications associated with bone marrow sampling in dogs and cats.

OBJECTIVES: To evaluate the prevalence of complications during bone marrow sampling and associated patient and procedural factors in dogs and cats. MATERIALS AND METHODS: Retrospective cohort study, records were evaluated to identify dogs and cats that had bone marrow sampling between 2012 and 2019. Data including signalment, the presence of specific clinicopathological findings, anatomical site of bone marrow sampling, number of attempts, diagnostic quality of sampling, analgesia protocol and complications postprocedure were recorded. RESULTS: A total of 131 dogs and 29 cats were included in the study. Complications were recorded in 22 of 160 (14%) of cases. Pain was the most common complication of bone marrow sampling in 20 of 22 (91%) of cases with bruising reported in the remaining patients. A local anaesthetic block was used in 98 of 160 (61%) of patients. CLINICAL SIGNIFICANCE: Excluding pain, complications associated with bone marrow sampling were rare and no clear association were detected between patient or procedural variables. Haemorrhage and infection are rare complications in dogs and cats when thrombocytopenia and neutropenia are present. Peri-procedure analgesia is strongly recommended to minimise complications.

Glucocorticoid metabolism and the action of 11 beta-hydroxysteroid dehydrogenase 2 in canine congestive heart failure.

The enzyme 11-beta-hydroxysteroid dehydrogenase isoenzyme 2 (11BHSD2) is responsible for converting the active glucocorticoid cortisol to inactive cortisone and in the renal medulla protects the mineralocorticoid receptor (MR) from activation by cortisol. Derangements in 11BHSD2 activity can result in reduced conversion of cortisol to cortisone, activation of the MR by cortisol and, consequently, sodium and water retention. The objective of this study was to examine glucocorticoid metabolism in canine congestive heart failure (CHF), specifically to evaluate whether renal 11BHSD2 activity and expression were altered. Dogs were prospectively recruited into one of two phases; the first phase (n=56) utilized gas chromatography-tandem mass spectrometry to examine steroid hormone metabolites normalised to creatinine in home-caught urine samples. Total serum cortisol was also evaluated. The second phase consisted of dogs (n=18) euthanased for refractory CHF or for behavioural reasons. Tissue was collected from the renal medulla for examination by quantitative reverse transcription polymerase chain reaction, immunohistochemistry and protein immune-blotting. Heart failure did not change urinary cortisol:cortisone ratio (P=0.388), or modify renal expression (P=0.303), translation (P=0.427) or distribution of 11BHSD2 (P=0.325). However, CHF did increase excretion of 5α-tetrahydrocortisone (P=0.004), α-cortol (P=0.002) and α-cortolone (P=0.009). Congestive heart failure modifies glucocorticoid metabolism in dogs by increasing 5α-reductase and 20α-hydroxysteroid dehydrogenase activity. Differences between groups in age, sex and underlying disease processes may have influenced these results. However, 11BHSD2 does not appear to be a potential therapeutic target in canine CHF.

Meta-hologram-based authentication scheme employing a speckle pattern fingerprint.

A concept for an optical holographic security tag is proposed and demonstrated. When illuminated with a laser beam, the image scattered from the tag projects a Quick Response code which encodes identifying information. The image also carries pseudorandom speckle noise, from which a unique speckle pattern "fingerprint" is derived. We show numerically that the tag is unclonable without access to a secret key - the starting conditions of the design algorithm. However, given the key, it is straightforward to reproduce a tag exhibiting the expected fingerprint. Several tags have been realized, implemented as plasmonic meta-holograms, and characterized experimentally. The robustness of the tag to fabrication error and its resilience to counterfeiting are studied in detail and demonstrated experimentally.

Glucocorticoid metabolism in critically ill dogs (Canis lupus familiaris).

Critical illness due to sepsis is a major global health concern associated with a high burden of mortality and cost. Glucocorticoid dysregulation in human sepsis is associated with poorer outcomes. This study examines glucocorticoid metabolism in septic canine patients to delineate elements of cellular dysregulation in common with critically ill humans and explore potential differences. This was a prospective case-control study conducted in the veterinary specialist critical care departments of two University teaching hospitals. Critically ill canine patients with naturally occurring sepsis or septic shock were compared with an in-hospital control population. Serum total, bound, and free cortisol concentrations were increased in septic shock (P < 0.001), and higher bound cortisol was associated with nonsurvival (P = 0.026). Urinary Gas Chromatography-Tandem Mass Spectrometry was performed to assess urinary glucocorticoid metabolites and estimate intracellular glucocorticoid metabolism. Decreased renal 11ß-hydroxysteroid dehydrogenase 2 (11ßHSD2) activity inferred from increased urinary cortisol-to-cortisone ratio was observed in critically ill dogs (P < 0.001). Decreased 11ßHSD2 activity (P = 0.019) and increased A-ring reduction of cortisone (P = 0.001) were associated with nonsurvival within the critically ill dogs. Intriguingly, two dogs were identified with low circulating total cortisol (<2 mg/dL) associated with increased A-ring reduction of cortisol, not previously described. Investigation of spontaneous canine sepsis and septic shock reveals dysregulation of cortisol to cortisone conversion similar to that observed in human patients, but with differences in A-ring reduction compared with those reported in humans. In addition, two dogs with high levels of cortisol inactivation associated with low circulating cortisol concentrations were identified.

Quantum noise radar: superresolution with quantum antennas by accessing spatiotemporal correlations.

We suggest overcoming the "Rayleigh catastrophe" and reaching superresolution for imaging with both spatially and temporally correlated field of a superradiant quantum antenna. Considering far-field radiation of two interacting spontaneously emitting two-level systems, we show that for the measurement of the temporally delayed second-order correlation function of the scattered field, the Fisher information does not tend to zero with diminishing the distance between a pair of scatterers even for non-sharp time-averaged detection. For position estimation of more scatterers, the measurement of the time-delayed function is able to provide a considerable accuracy gain over the zero-delayed function. We also show that the superresolution with the considered quantum antenna can be achieved for both near-field imaging and for estimating the antenna parameters.

Epidemiology of road traffic accidents in cats attending emergency-care practices in the UK.

OBJECTIVES: To estimate the incidence proportion of road traffic accidents in cats attending emergency out-of-hours clinics in the UK, identify major risk factors for road traffic accident occurrence and for survival to discharge. MATERIALS AND METHODS: A retrospective study of a cohort of 33,053 cats in the VetCompass database attending emergency-care practice between January 1, 2012 and February 15, 2014. Incidence proportion was calculated and logistic regression was used to identify risk factors for road traffic accident and survival to discharge following road traffic accident. RESULTS: Incidence proportion was estimated at 4∙2% (95% confidence interval: 4∙0 to 4∙4%). Cats aged 6 months to 2 years were at increased odds of road traffic accident, as were male cats and crossbred cats. Odds of road traffic accident were highest in the autumn. Spinal injury, abdominal injury and increasing count of injuries were associated with increased odds of death. CLINICAL SIGNIFICANCE: Road traffic accident is a frequent presentation in emergency-care practice. Identification of risk factors for death within the first 24 hours following a road traffic accident can aid veterinarian and owner decision-making for treatment of cats involved in a road traffic accident.

Gastric dilation-volvulus in dogs attending UK emergency-care veterinary practices: prevalence, risk factors and survival.

OBJECTIVE: To report prevalence, risk factors and clinical outcomes for presumptive gastric dilation-volvulus diagnosed among an emergency-care population of UK dogs. METHODS: The study used a cross-sectional design using emergency-care veterinary clinical records from the VetCompass Programme spanning September 1, 2012 to February 28, 2014 and risk factor analysis using multivariable logistic regression modelling. RESULTS: The study population comprised 77,088 dogs attending 50 Vets Now clinics. Overall, 492 dogs had presumptive gastric dilation-volvulus diagnoses, giving a prevalence of 0·64% (95% Confidence interval: 0·58 to 0·70%). Compared with cross-bred dogs, breeds with the highest odds ratios for the diagnosis of presumptive gastric dilation-volvulus were the great Dane (odds ratio: 114·3, 95% Confidence interval 55·1 to 237·1, P<0·001), akita (odds ratio: 84·4, 95% Confidence interval 33·6 to 211·9, P<0·001) and dogue de Bordeaux (odds ratio: 82·9, 95% Confidence interval 39·0 to 176·3, P<0·001). Odds increased as dogs aged up to 12 years and neutered male dogs had 1·3 (95% Confidence interval 1·0 to 1·8, P=0·041) times the odds compared with entire females. Of the cases that were presented alive, 49·7% survived to discharge overall, but 79·3% of surgical cases survived to discharge. CLINICAL SIGNIFICANCE: Approximately 80% of surgically managed cases survived to discharge. Certain large breeds were highly predisposed.

Coagulation status in dogs with naturally occurring Angiostrongylus vasorum infection.

OBJECTIVES: Angiostrongylus vasorum infection is associated with bleeding tendencies in approximately one-third of clinical cases. The cause of the coagulopathy is poorly understood but may be related to disseminated intravascular coagulation. Thromboelastography is a global evaluation of coagulation and has not been described in a cohort of dogs with this disease. MATERIALS AND METHODS: Thromboelastography in association with other measures of coagulation including prothrombin and activated partial thromboplastin times, antithrombin percentage activity and D-dimer and von Willebrand factor concentrations was evaluated in a group of 30 dogs with A. varosum infection. RESULTS: A total of 18 dogs had signs of bleeding on physical examination. Thromboelastography was consistent with hypocoagulation in 17 of these dogs. There was no association between any of the other measures and hypocoagulation on thromboelastography. Abnormal coagulation times were not significantly associated with bleeding. Only fibrinogen concentration was significantly lower in dogs that were bleeding compared with those that were not (P = 0 · 026). D-dimer concentrations were increased in 22/25 cases in the study; however, other coagulation parameters were more variable. CLINICAL SIGNIFICANCE: Although the changes identified in this study were not consistent, there is activation of coagulation within this population, possibly consistent with an intravascular disseminated coagulopathy.

Spatial, demographic and clinical patterns of Angiostrongylus vasorum infection in the dog population of Southern England.

A retrospective study was carried out to provide updated knowledge of the spatial pattern of Angiostrongylus vasorum infection in Southern England and to investigate associations between selected host characteristics (age, breed, sex), risk of infection and clinical presentation (cardiorespiratory signs v haemorrhagic diathesis). One hundred and forty-one cases diagnosed between April 1999 and July 2012 were compared with a control population of dogs referred to the same hospital. A significant association was found between haemorrhagic diathesis and breed but not for other host characteristics and clinical presentations. Younger dogs and certain breeds of dog (Jack Russell terriers, Cocker Spaniels, Springer Spaniels, Cavalier King Charles spaniels and Staffordshire Bull Terriers) had significantly higher odds of angiostrongylosis than other breeds in the study. A significant cluster of cases was found in Southern England. Animals presenting with cardiorespiratory signs or haemorrhagic diathesis in Southern England, especially if they are young or of a breed associated with angiostrongylosis, should be given special consideration with regards to possible A. vasorum infestation. Our results should be interpreted bearing in mind that they are based on the retrospective exploration of dogs seen at a referral centre.

Coagulation factor and hemostatic protein content of canine plasma after storage of whole blood at ambient temperature.

BACKGROUND: Standard practice in canine blood banking is to produce fresh frozen plasma (FFP) by separating and freezing plasma produced from blood within 8 hours of collection. Within canine blood donation programs, this can limit the number of units collected. HYPOTHESIS/OBJECTIVES: The aim was to compare the coagulation factor and hemostatic protein content (CF&HPC) of plasma produced from blood stored at ambient temperature for 8, 12, and 24 hours. Another aim was to compare the CF&HPC between Greyhound types and other breeds. ANIMALS: None. METHODS: In vitro study. A convenience sample of 58 units of canine blood from a blood donor pool was processed to prepare and freeze plasma 8, 12, or 24 hours following collection. RESULTS: Regardless of time of processing, the units contained therapeutic CF&HPC. Frozen plasma prepared after 24 hours had significantly higher factor VIII (P = .014) and factor X (P = .03) when compared with the frozen plasma prepared at 8 hours. Factor X (P < .01), fibrinogen (P < .01), and vWF (P = .04) were significantly lower in plasma collected from Greyhound types than in plasma collected from other breeds. CONCLUSIONS AND CLINICAL IMPORTANCE: Storing whole blood for up to 24 hours is a suitable method for producing FFP. Lower values for some coagulation factors and hemostatic proteins in plasma produced from Greyhound types would not preclude these dogs as FFP donors.

Reconstruction of surface potential from Kelvin probe force microscopy images.

We present an algorithm for reconstructing a sample surface potential from its Kelvin probe force microscopy (KPFM) image. The measured KPFM image is a weighted average of the surface potential underneath the tip apex due to the long-range electrostatic forces. We model the KPFM measurement by a linear shift-invariant system where the impulse response is the point spread function (PSF). By calculating the PSF of the KPFM probe (tip+cantilever) and using the measured noise statistics, we deconvolve the measured KPFM image to obtain the surface potential of the sample.The reconstruction algorithm is applied to measurements of CdS-PbS nanorods measured in amplitude modulation KPFM (AM-KPFM) and to graphene layers measured in frequency modulation KPFM (FM-KPFM). We show that in the AM-KPFM measurements the averaging effect is substantial, whereas in the FM-KPFM measurements the averaging effect is negligible.

Direct measurement of individual deep traps in single silicon nanowires.

The potential of the metal nanocatalyst to contaminate vapor-liquid-solid (VLS) grown semiconductor nanowires has been a long-standing concern, since the most common catalyst material, Au, is known to induce deep gap states in several semiconductors. Here we use Kelvin probe force microscopy to image individual deep acceptor type trapping centers in single undoped Si nanowires grown with an Au catalyst. The switching between occupied and empty trap states is reversibly controlled by the back-gate potential in a nanowire transistor. The trap energy level, i.e., E(C) - E(T) = 0.65 ± 0.1 eV was extracted and the concentration was estimated to be ∼2 × 10(16) cm(-3). The energy and concentration are consistent with traps resulting from the unintentional incorporation of Au atoms during the VLS growth.

Evaluation of surface contamination with staphylococci in a veterinary hospital using a quantitative microbiological method.

OBJECTIVES: To evaluate microbial contamination of the environment in a veterinary hospital using standards recommended for human hospitals and to provide a baseline against which further investigations can be compared. METHODS: Surfaces were sampled twice daily for five consecutive days using a contact-based counting method to measure the levels of staphylococci in colony forming units (cfu) per cm². RESULTS: Current recommendations for human hospitals were applied in this study; all samples with <2.5 cfu/cm² staphylococci were considered to have passed and those with ≥2.5 cfu/cm² to have failed. Of all the samples, 55.9% failed. The ICU did not have significantly higher failure rates than other areas of the hospital. The floor as a surface was associated with greater than a threefold increase in odds of elevated cfu concentrations relative to the door handle. CLINICAL SIGNIFICANCE: This study provides information on the microbiological cleanliness of a veterinary teaching hospital using techniques and standards adopted by the food industry and recommended for human hospitals. This data can be used as a baseline for other hospitals, to evaluate the effectiveness in improvements in hygiene and cleaning measures and to design effective hospital cleaning protocols and assess ongoing hygiene standards.

Factors contributing to the contamination of peripheral intravenous catheters in dogs and cats.

The aim of this study was to identify factors that contribute significantly to the bacterial contamination of peripheral intravenous catheters in dogs and cats. Between January and June 2005, intravenous catheters were removed from 84 dogs and 15 cats at the Queen Mother Hospital for Animals, Royal Veterinary College. None of the factors under consideration was significantly associated with bacterial contamination, but 42.9 per cent of the animals with clinical signs consistent with a peripheral catheter-related infection, 34.8 per cent of the animals in which blood had been collected from the catheter immediately after its insertion, and 21.1 per cent of the animals in which a T-connector rather than a Y-connector had been used had contaminated cannulae, compared with 19.0 per cent, 19.7 per cent and 8.3 per cent, respectively, of the animals that did not have signs of such an infection, from which blood was not taken immediately, and that had a Y-connector rather than a T-connector. Binary logistic regression showed that the animals with clinical signs of a catheter-related infection were 10 times more likely to have a contaminated catheter (odds ratio [OR] 10.9, 95 per cent confidence interval [CI] 0.89 to 134) and the animals fitted with Y-connectors rather than T-connectors were 10 times less likely to have a contaminated catheter (OR 0.10, 95 per cent CI 0.008 to 1.25).