A multicentre observational study to investigate feasibility of a direct oral penicillin challenge in de-labelling 'low risk' patients with penicillin allergy by non-allergy healthcare professionals (SPACE study): Implications for healthcare systems

OBJECTIVE

The huge burden of inaccurate penicillin allergy labels (PALs) is an important driver of antimicrobial resistance. This is magnified by insufficient allergy specialists and lack of 'point-of-care' tests. We investigated the feasibility of non-allergy healthcare professionals (HCPs) delivering direct oral penicillin challenges (DPCs) for penicillin allergy de-labelling.

METHODS

This prospective observational study was conducted in three hospitals in England across three settings (acute medical, pre-surgical and haematology-oncology). Patients with a PAL were screened and stratified as low risk/high risk. Low risk patients (non-immune mediated symptoms, benign rash, tolerated amoxicillin since and family history) underwent a DPC.

RESULTS

N = 2257 PALs were screened, 1054 were eligible; 643 were approached, 373 declined, 270 consented and 259 risk stratified (low risk = 155; high risk = 104). One hundred and twenty-six low risk patients underwent DPC, 122 (96.8%) were de-labelled with no serious allergic reactions. Conversion rate from screening-to-consent was 12% [3.3% and 17.9% in acute and elective settings respectively; odds ratios for consent were 3.42 (p < 0.001) and 5.53 (p < 0.001) in haematology-oncology and pre-surgical setting respectively. Common reasons for failure to progress in the study included difficulty in reaching patients, clinical instability/medical reasons, lacking capacity to consent and psychological factors.

INTERPRETATION

DPCs can be delivered by non-allergy HCPs. A high proportion of patients with PALs did not progress in the study pathway. Strategies to deliver DPC at optimal points of the care pathway are needed to enhance uptake. Elective settings offer greater opportunities than acute settings for DPC. The safety and simplicity of DPCs lends itself to adoption by healthcare systems beyond the UK, including in resource-limited settings.

Perioperative visual loss and consent for adult spine surgery: a national survey of the practice amongst spine surgeons and anaesthetists†

BACKGROUND

Perioperative Visual Loss (POVL) is a devastating complication for patients undergoing spine surgery. Consent process for POVL amongst spine surgeons and anaesthetist remains variable. The aim of this study is to evaluate their practice and views about it.

METHODS

Two similar questionnaires were distributed to members of the Society of British Neurological Surgeons (SBNS), British Association of Spine Surgeons (BASS), and Neuroanaesthsia and Critical Care Society (NACCS).

RESULTS

A total of 271 responses were received (SBNS/BASS n = 149, NACCS n = 122). Fewer surgeons considered POVL as a material risk for patients compared to the anaesthetists (57.7 versus 79.7%). Outpatient/pre-assessment clinics were considered as the optimal setting for discussing POVL by the majority of the clinicians (81.2 and 93.4%). POVL should be discussed by both specialists according to 75% of the anaesthetists. Estimated incidence of POVL was considered to be higher by the anaesthetists (0.03-0.2% by 63% of the anaesthetist versus 0.0001-0.004% by 57% of the surgeons). Twenty-three surgeons and 10 anaesthetists had a patient who suffered from POVL, which led to a change of practice in most of them. This questionnaire will lead to a change in practice/consent to 18.1% of the surgeons and 23.5% of the anaesthetists.

CONCLUSIONS

Most of the surgeons and anaesthetist feel that POVL is a material risk that ideally needs to be firstly discussed before the day of surgery, by both specialties. However, a significant number of clinicians have an opposite view. A national guidance from respective societies should encourage POVL to be discussed routinely.

Effect of conventional multilevel brachycephalic obstructive airway syndrome surgery on clinical and videofluoroscopic evidence of hiatal herniation and gastroesophageal reflux in dogs

OBJECTIVE

To evaluate the effect of conventional multilevel surgery (CMS) for brachycephalic obstructive airway syndrome (BOAS) on associated sliding hiatal hernia (SHH) and/or gastroesophageal reflux (GER).

STUDY DESIGN

Prospective clinical trial.

ANIMALS

Sixteen client-owned dogs with clinical signs consistent with BOAS and associated SHH and GER.

METHODS

All dogs were treated with 1 or more components of CMS including soft palate resection, laryngeal ventriculectomy, and alaplasty. A standardized Dog Swallowing Assessment Tool (Dog SAT) questionnaire was completed by owners preoperatively and postoperatively. Videofluoroscopic swallow studies (VFSS) were used to evaluate esophageal motility, gastroesophageal reflux, and hiatal herniation preoperatively, and in a subset of dogs postoperatively. Upper gastrointestinal endoscopic studies were performed to document esophagitis and lower esophageal sphincter pathology.

RESULTS

All dogs were discharged from the hospital. One dog experienced aspiration pneumonia immediately postoperatively. Owner-assigned clinical scores improved in scores related to regurgitation after eating and regurgitation (P = .012) during increased activity/exercise (P = .002) between preoperative and postoperative time points. However, no improvement was detected in masked assessment of preoperative and postoperative VFSS studies in terms of GER frequency (P = .46) or severity (P = .79), SHH frequency (P = .082) or severity (P = .34) scores.

CONCLUSION

Owners of dogs treated with CMS perceived an improvement in clinical signs of SHH and GER that was not confirmed by VFSS studies.

CLINICAL SIGNIFICANCE

Conventional multilevel surgery in dogs with BOAS does not appear to consistently resolve SHH and GER, although clinical signs may improve.

Dam-Infant Rhesus Macaque Pairs to Dissect Age-Dependent Responses to SARS-CoV-2 Infection

The global spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its associated coronavirus disease (COVID-19) has led to a pandemic of unprecedented scale. An intriguing feature of the infection is the minimal disease in most children, a demographic at higher risk for other respiratory viral diseases. To investigate age-dependent effects of SARS-CoV-2 pathogenesis, we inoculated two rhesus macaque monkey dam-infant pairs with SARS-CoV-2 and conducted virological and transcriptomic analyses of the respiratory tract and evaluated systemic cytokine and Ab responses. Viral RNA levels in all sampled mucosal secretions were comparable across dam-infant pairs in the respiratory tract. Despite comparable viral loads, adult macaques showed higher IL-6 in serum at day 1 postinfection whereas CXCL10 was induced in all animals. Both groups mounted neutralizing Ab responses, with infants showing a more rapid induction at day 7. Transcriptome analysis of tracheal airway cells isolated at day 14 postinfection revealed significant upregulation of multiple IFN-stimulated genes in infants compared with adults. In contrast, a profibrotic transcriptomic signature with genes associated with cilia structure and function, extracellular matrix composition and metabolism, coagulation, angiogenesis, and hypoxia was induced in adults compared with infants. Our study in rhesus macaque monkey dam-infant pairs suggests age-dependent differential airway responses to SARS-CoV-2 infection and describes a model that can be used to investigate SARS-CoV-2 pathogenesis between infants and adults.

Parental education and youth suicidal behaviours: a systematic review and meta-analysis

AIMS

Lower parental education has been linked to adverse youth mental health outcomes. However, the relationship between parental education and youth suicidal behaviours remains unclear. We explored the association between parental education and youth suicidal ideation and attempts, and examined whether sociocultural contexts moderate such associations.

METHODS

We conducted a systematic review and meta-analysis with a systematic literature search in PubMed, PsycINFO, Medline and Embase from 1900 to December 2020 for studies with participants aged 0-18, and provided quantitative data on the association between parental education and youth suicidal ideation and attempts (death included). Only articles published in English in peer-reviewed journals were considered. Two authors independently assessed eligibility of the articles. One author extracted data [e.g. number of cases and non-cases in each parental education level, effect sizes in forms of odds ratios (ORs) or beta coefficients]. We then calculated pooled ORs using a random-effects model and used moderator analysis to investigate heterogeneity.

RESULTS

We included a total of 59 articles (63 study samples, totalling 2 738 374 subjects) in the meta-analysis. Lower parental education was associated with youth suicidal attempts [OR = 1.12, 95% Confidence Interval (CI) = 1.04-1.21] but not with suicidal ideation (OR = 1.05, 95% CI = 0.98-1.12). Geographical region and country income level moderated the associations. Lower parental education was associated with an increased risk of youth suicidal attempts in Northern America (OR = 1.26, 95% CI = 1.10-1.45), but with a decreased risk in Eastern and South-Eastern Asia (OR = 0.72, 95% CI = 0.54-0.96). An association of lower parental education and increased risk of youth suicidal ideation was present in high- income countries (HICs) (OR = 1.14, 95% CI = 1.05-1.25), and absent in low- and middle-income countries (LMICs) (OR = 0.91, 95% CI = 0.77-1.08).

CONCLUSIONS

The association between youth suicidal behaviours and parental education seems to differ across geographical and economical contexts, suggesting that cultural, psychosocial or biological factors may play a role in explaining this association. Although there was high heterogeneity in the studies reviewed, this evidence suggests that the role of familial sociodemographic characteristics in youth suicidality may not be universal. This highlights the need to consider cultural, as well as familial factors in the clinical assessment and management of youth's suicidal behaviours in our increasingly multicultural societies, as well as in developing prevention and intervention strategies for youth suicide.

Monoclonal antibodies protect aged rhesus macaques from SARS-CoV-2-induced immune activation and neuroinflammation

Anti-viral monoclonal antibody (mAb) treatments may provide immediate but short-term immunity from coronavirus disease 2019 (COVID-19) in high-risk populations, such as people with diabetes and the elderly; however, data on their efficacy in these populations are limited. We demonstrate that prophylactic mAb treatment blocks viral replication in both the upper and lower respiratory tracts in aged, type 2 diabetic rhesus macaques. mAb infusion dramatically curtails severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-mediated stimulation of interferon-induced chemokines and T cell activation, significantly reducing development of interstitial pneumonia. Furthermore, mAb infusion significantly dampens the greater than 3-fold increase in SARS-CoV-2-induced effector CD4 T cell influx into the cerebrospinal fluid. Our data show that neutralizing mAbs administered preventatively to high-risk populations may mitigate the adverse inflammatory consequences of SARS-CoV-2 exposure.

737 Supporting Surgeons in Their Return to Training

Aim

t any one time, approximately 10% of the junior doctor workforce (∼5000 doctors) take time out of training. Following the Bawa Gaba case, and with trainees shielding during the COVID pandemic, there is greater scrutiny and demand to support trainees returning to the frontline. Supported Return to Training (SuppoRTT) is a Health Education England Program designed to improve the Return-To-Training (RTT) experience. For surgical specialties there are additional challenges of reintroducing trainees to practical skills.

Method

e designed and facilitated the first regional SuppoRTT course for Orthopaedic Specialist Registrars, which consisted of peer and consultant-led clinical updates, forum discussions and externally commissioned professional coaching. A pre-course survey established participants’ concerns and expectations about RTT and formed the basis of discussions. A post-course survey assessed value of the course and impact on participants.

Results

Eight participants (6 female) attended. Grade of training on return ranged from ST3 to ST8. Main areas of concern related to colleague perception, reduced confidence with decision-making, operative skill fade, and frustrations with organisational elements of managing work-life balance. There was an overwhelmingly positive response to the support offered on our course, particularly to the discussions around RTT concerns and returning to on-calls. All respondents strongly agreed that sharing their concerns and hearing about peer experience was valuable.

Conclusions

High numbers of trainees take approved time out of training. RTT is associated with anxiety around performance and safety. Surgical trainees can be supported with a targeted course that offers clinical update, peer support and professional coaching.

A systematic review and taxonomy of tools for evaluating evidence-based medicine teaching in medical education

BACKGROUND

The importance of teaching the skills and practice of evidence-based medicine (EBM) for medical professionals has steadily grown in recent years. Alongside this growth is a need to evaluate the effectiveness of EBM curriculum as assessed by competency in the five 'A's': asking, acquiring, appraising, applying and assessing (impact and performance). EBM educators in medical education will benefit from a compendium of existing assessment tools for assessing EBM competencies in their settings. The purpose of this review is to provide a systematic review and taxonomy of validated tools that evaluate EBM teaching in medical education.

METHODS

We searched MEDLINE, EMBASE, Cochrane library, Educational Resources Information Centre (ERIC), Best Evidence Medical Education (BEME) databases and references of retrieved articles published between January 2005 and March 2019. We have presented the identified tools along with their psychometric properties including validity, reliability and relevance to the five domains of EBM practice and dimensions of EBM learning. We also assessed the quality of the tools to identify high quality tools as those supported by established interrater reliability (if applicable), objective (non-self-reported) outcome measures and achieved ≥ 3 types of established validity evidence. We have reported our study in accordance with the PRISMA guidelines.

RESULTS

We identified 1719 potentially relevant articles of which 63 full text articles were assessed for eligibility against inclusion and exclusion criteria. Twelve articles each with a unique and newly identified tool were included in the final analysis. Of the twelve tools, all of them assessed the third step of EBM practice (appraise) and four assessed just that one step. None of the twelve tools assessed the last step of EBM practice (assess). Of the seven domains of EBM learning, ten tools assessed knowledge gain, nine assessed skills and-one assessed attitude. None addressed reaction to EBM teaching, self-efficacy, behaviours or patient benefit. Of the twelve tools identified, six were high quality. We have also provided a taxonomy of tools using the CREATE framework, for EBM teachers in medical education.

CONCLUSIONS

Six tools of reasonable validity are available for evaluating most steps of EBM and some domains of EBM learning. Further development and validation of tools that evaluate all the steps in EBM and all educational outcome domains are needed.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018116203.

Abstract OT1-08-02: TRYbeCA-2: A randomized phase 2/3 study of eryaspase in combination with gemcitabine and carboplatin chemotherapy versus chemotherapy alone as first-line treatment in patients with metastatic or locally recurrent triple-negative breast cancer (NCT03674242)

Background: Triple Negative Breast Cancer (TNBC) represents approximately 15% of all breast cancer. It confers a poorer prognosis relative to the other breast cancer subtypes, with an increased likelihood of recurrence and death within 5 years of diagnosis. There is no standard of care specifically for patients presenting with TNBC.

Altered amino acid metabolism have been shown to play a role in TNBC. Eryaspase, asparaginase (ASNase) encapsulated in red blood cells (RBCs) is an investigational product under development. Following infusion, asparagine and glutamine are actively transported into RBCs where they are hydrolyzed by the encapsulated ASNase. In a recent randomized Phase 2b study, eryaspase has demonstrated evidence of improved overall survival (OS) and progression free survival (PFS) and acceptable safety when combined with gemcitabine or FOLFOX therapy in patients with advanced pancreatic cancer whose disease progressed following first-line treatment (NCT02195180). The demonstration of ASNase activity of eryaspase in combination with chemotherapy including DNA-damaging agents in both preclinical and clinical settings provide a rationale to further test combination in TNBC.

Methods: TRYbeCA-2 is an international, randomized, open-label Phase 2/3 trial (N=64 for Phase 2) of eryaspase combined with chemotherapy in patients with locally recurrent or metastatic TNBC who have not received prior systemic therapy for locally recurrent or metastatic disease. Patients are randomized in a 1:1 ratio to receive gemcitabine/carboplatin with or without eryaspase, administered as IV infusion on Day 1 and Day 8 of each 3-week cycle.

Key eligibility criteria include measurable lesion(s), performance status 0 or 1, and adequate organ function. The primary endpoint is the objective response rate (ORR) as determined by an independent radiological review. Key secondary endpoints include ORR as determined by the investigator’s assessment, clinical benefit rate, overall survival, progression-free survival, safety, biomarker research, pharmacokinetics and pharmacodynamics.

A steering committee will be established to review safety at regular intervals and to review safety and efficacy data at the end of the Phase 2 to determine whether or not to proceed to Phase 3. The study is planned in European countries. Several sites have already been initiated and at least one patient was enrolled at the time of submitting this abstract.

Citation Format: Ahmad Awada, Javier Cortes, Sarah Slater, Iain MacPherson, Tibor Csoszi, Jean-Baptiste Bertrand, Anne-Sophie Clermont, Rachel Pollard, Romain Chrestia-Blanchine, Nigel Biswas-Baldwin, Hagop Youssoufian, Iman El-Hariry. TRYbeCA-2: A randomized phase 2/3 study of eryaspase in combination with gemcitabine and carboplatin chemotherapy versus chemotherapy alone as first-line treatment in patients with metastatic or locally recurrent triple-negative breast cancer (NCT03674242) [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr OT1-08-02.

Bioengineered in vitro enteric nervous system

Bidirectional interactions between the human central nervous system and the gastrointestinal tract, via the enteric nervous system, are unmapped and central to many human conditions. There is a critical need to develop 3D human in vitro intestinal tissue models to emulate the intricate cell interactions of the human enteric nervous system within the gastrointestinal tract in order to better understand these complex interactions that cannot be studied utilizing in vivo animal models. In vitro systems, if sufficiently replicative of some in vivo conditions, may assist with the study of individual cell interactions. Here, we describe a 3D-innervated tissue model of the human intestine consisting of human-induced neural stem cells differentiated into relevant enteric nervous system neural cell types. Enterocyte-like (Caco-2) and goblet-like (HT29-MTX) cells are used to form the intestinal epithelial layer, and intestinal myofibroblasts are utilized to simulate the stromal layer. In vitro enteric nervous system cultures supported survival and function of the various cell types, with mucosal and neural transcription factors evident over 5 weeks. The human-induced neural stem cells migrated from the seeding location on the peripheral layer of the hollow scaffolds toward the luminal epithelial cells, prompted by the addition of neural growth factor. nNOS-expressing neurons and the substance P precursor gene TAC1 were expressed within the in vitro enteric nervous system to support the utility of the tissue model to recapitulate enteric nervous system phenotypes. This innervated tissue system offers a new tool to use to help in understanding neural circuits controlling the human intestine and associated communication networks.

Entry-Level Spatial and General Non-verbal Reasoning: Can These Abilities be Used as a Predictor for Anatomy Performance in Veterinary Medical Students?

There is currently limited available information, but growing interest, in possible relationships between spatial visualization skills in medical students and their academic performance in select areas of the curriculum such as radiographic interpretation and anatomy. There is very limited comparable information on how entry-level spatial visualization skills may correlate with macroscopic anatomy performance in veterinary medical students exposed to an integrated curriculum. The present study made use of a battery of two short tests that measure spatial ability: Guay's visualization of views test (VVT) and mental rotation test (MRT) and, one test that measures general non-verbal reasoning abilities: Raven's Advanced Progressive Matrices Test, short form (APMT). Tests were given to 1st-year veterinary medical students (n = 124) immediately before commencing the integrated veterinary medical curriculum. Results show there is a positive correlation between entry-level spatial ability and non-verbal general reasoning scores confirming these abilities are linked (r: +0.22 and +0.3 for VVT/APMT and MRT/APMT respectively). The dispersion and inconsistency of significant positive correlation between anatomy practical exams grade and spatial and general reasoning scores suggest these abilities either do not correlate with anatomy practical exams grade or, are overcome with progression through the anatomy courses. Males scored higher than females in the spatial ability tests: 16.59 vs. 12.06 for VVT (p = 0.01) and 19.0 vs. 14.68 for MRT (p = 0.01). Scores for APMT did not show a significant difference by gender.

Consistency and effect of body position change on measurement of upper and lower esophageal sphincter geometry using impedance planimetry in a canine model

The EndoFLIP (Endolumenal Functional Lumen Imaging Probe, Crospon Inc, Galway, Ireland) device uses the technique of impedance planimetry to evaluate dimensions and distensibility of the upper and lower esophageal sphincter. The null hypotheses for this study were that EndoFLIP variables would be stable between anesthestic episodes and would not be affected by body position when evaluating the upper and lower esophageal sphincters in healthy dogs. During each of three consecutive general anesthesia episodes administered to eight healthy adult research colony dogs with a standardized protocol, the EndoFLIP catheter was positioned to measure cross-sectional area, intrabag pressure, upper and lower esophageal sphincter length at two different balloon fill volumes (30 and 40 mL) and two body positions (lateral and dorsal recumbency). From these measured variables, a distensibility index was also calculated. Mixed effect analysis of variance was used to evaluate the fixed marginal and interaction effects of anesthesia episode, body position, and balloon volume on measured and calculated variables. For the upper esophageal sphincter significant interactions were present between anesthetic episode and body position for all variables except intrabag pressure; adjusting for body position significant differences were present between anesthetic episodes for all variables except distensibility index; adjusting for anesthetic episode cross-sectional area, intrabag pressure, upper esophageal sphincter length and distensibility index were all affected by body position. For the lower esophageal sphincter distensibility index was the only variable where a significant interaction between anesthesia episode and body position occurred; cross-sectional area, intrabag pressure, and lower esophageal length were not significantly affected by anesthesia episode when adjusting for body position; distensibility index was the only variable significantly affected by body position. Measurements of the geometry of the lower esophageal sphincter as measured by the EndoFLIP device were consistent under conditions of general anesthesia. Similar measurements taken at the upper esophageal sphincter displayed greater variability between anesthetic episodes and were affected to a greater extent by body position. Body position should be standardized in studies using the EndoFLIP to assess geometric and functional characteristics of the upper and lower esophageal sphincters.

Total laryngectomy for management of chronic aspiration pneumonia in a myopathic dog

A 5-month-old female pit bull terrier dog evaluated for ataxia, progressive regurgitation, and recurrent aspiration pneumonia had markedly elevated creatine kinase activity, non-inflammatory generalized myopathy, and severe esophageal dysmotility. A narrow-field total laryngectomy was performed. The dog is doing well 30 months after surgery, and no longer has episodes of aspiration pneumonia, despite intermittent regurgitation. This case represents the first application of total laryngectomy for the prevention of chronic recurrent aspiration pneumonia in the dog.

Optical and magneto-optical properties of gold core cobalt shell magnetoplasmonic nanowire arrays

In this work we present core-shell nanowire arrays of gold coated with a nanometric layer of cobalt. Despite the extremely small Co volume, these core-shell nanowires display large magneto-optical activity and plasmonic resonance determined by the geometry of the structure. Therefore, we are able to tune both the plasmonic and magneto-optical response in the visible range. Through optical and ellipsometric measurements in transmission, and applying a magnetic field to the sample, it is possible to modulate the value of the phase angle (Del {Δ}) between the S and P polarised components. It was found that the core-shell sample produced an order of magnitude larger variation in Del with changing magnetic field direction, compared with hollow cobalt tubes. The enhancement of magneto optical properties through the plasmonic nature of the gold core is complemented with the ability to induce magnetic influence over optical properties via an externally applied field. Moreover, we demonstrate for the first time the ability to use the remanent magnetisation of the Co, in conjunction with the optical properties defined by the Au, to observe remanent optical states in this uniquely designed structure. This new class of magnetoplasmonic metamaterial has great potential in a wide range of applications, from bio-sensing to data storage due to the tuneable nature of multiple resonance modes and dual functionality.

Genetic variation corroborates subspecific delimitation in the Namib fog-basking beetle, Onymacris unguicularis (Haag) (Tenebrionidae, Coleoptera)

The fog-basking beetle, Onymacris unguicularis (Haag, 1875), is currently listed as a polytypic form comprising two subspecies. A flightless substrate specialist, the beetleis endemic to vegetationless dunes in the Namib, where southern populations constitute the nominate subspecies, O. u. unguicularis, and populations some 300 km to the north compose O. u. schulzeae Penrith, 1984. Their taxonomic descriptions are based on minor differences in pronotal and prosternal shape, and the phylogenetic validity of these subspecies has yet to be ascertained. Here we reassess the polytypic status of O. unguicularis by (1) examining diagnostic phenotypic characters in conjunction with a geometric morphometric analysis, and (2) conducting phylogenetic analysis of mitochondrial DNA sequences. Our results confirm pronotal and prosternal differences, which are complemented by geometric morphometric resolution of the subspecies. Phylogenetic analysis recovered two reciprocally monophyletic lineages that exhibit perfect phylogeographic congruence with phenotypic variation. Our genetic data identify southern and northern populations as distinct lineages, corroborate morphometric data regarding subspecific delimitation, and therefore support the recognition of O. u. unguicularis and O. u. schulzeae as valid taxa under the general lineage concept.

Designed ultrafast optical nonlinearity in a plasmonic nanorod metamaterial enhanced by nonlocality

All-optical signal processing enables modulation and transmission speeds not achievable using electronics alone. However, its practical applications are limited by the inherently weak nonlinear effects that govern photon-photon interactions in conventional materials, particularly at high switching rates. Here, we show that the recently discovered nonlocal optical behaviour of plasmonic nanorod metamaterials enables an enhanced, ultrafast, nonlinear optical response. We observe a large (80%) change of transmission through a subwavelength thick slab of metamaterial subjected to a low control light fluence of 7 mJ cm(-2), with switching frequencies in the terahertz range. We show that both the response time and the nonlinearity can be engineered by appropriate design of the metamaterial nanostructure. The use of nonlocality to enhance the nonlinear optical response of metamaterials, demonstrated here in plasmonic nanorod composites, could lead to ultrafast, low-power all-optical information processing in subwavelength-scale devices.

Plasmonic nanorod metamaterials for biosensing

Label-free plasmonic biosensors rely either on surface plasmon polaritons or on localized surface plasmons on continuous or nanostructured noble-metal surfaces to detect molecular-binding events. Despite undisputed advantages, including spectral tunability, strong enhancement of the local electric field and much better adaptability to modern nanobiotechnology architectures, localized plasmons demonstrate orders of magnitude lower sensitivity compared with their guided counterparts. Here, we demonstrate an improvement in biosensing technology using a plasmonic metamaterial that is capable of supporting a guided mode in a porous nanorod layer. Benefiting from a substantial overlap between the probing field and the active biological substance incorporated between the nanorods and a strong plasmon-mediated energy confinement inside the layer, this metamaterial provides an enhanced sensitivity to refractive-index variations of the medium between the rods (more than 30,000 nm per refractive-index unit). We demonstrate the feasibility of our approach using a standard streptavidin-biotin affinity model and record considerable improvement in the detection limit of small analytes compared with conventional label-free plasmonic devices.

Guided plasmonic modes in nanorod assemblies: strong electromagnetic coupling regime

We demonstrate that the coupling between plasmonic modes of oriented metallic nanorods results in the formation of an extended (guided) plasmonic mode of the nanorod array. The electromagnetic field distribution associated to this mode is found to be concentrated between the nanorods within the assembly and propagates normally to the nanorod long axes, similar to a photonic mode waveguided by an anisotropic slab. This collective plasmonic mode determines the optical properties of nanorod assemblies and can be tuned in a wide spectral range by changing the nanorod array geometry. This geometry represents a unique opportunity for light guiding applications and manipulation at the nanoscale as well as sensing applications and development of molecular plasmonic devices.

Serum insulin-like growth factor-I concentration in cats with diabetes mellitus and acromegaly

BACKGROUND

Serum insulin-like growth factor-I (IGF-I) has been used in place of serum growth hormone quantification for identifying acromegaly in diabetic cats. The utility of IGF-I as a screening test for acromegaly has not been critically evaluated. This retrospective study was performed to evaluate the usefulness of serum IGF-I concentration for identifying acromegaly.

HYPOTHESIS

Serum IGF-I is a useful screening test for acromegaly in diabetic cats.

ANIMALS

A review was made of the medical records of 74 diabetic cats that had serum IGF-I quantified. The diabetes was classified as well controlled (15 cats), poorly controlled because of problems with the insulin treatment regimen, concurrent disease, or both (40), or poorly controlled with clinical findings consistent with acromegaly (19).

METHODS

A review of medical records was made.

RESULTS

Serum IGF-I concentration was significantly (P < .0001) increased in acromegalic diabetic cats, compared with well-controlled and poorly controlled diabetic cats. Sensitivity and specificity for serum IGF-I concentration were 84% (95%/ confidence interval [CI] = 60.4-96.6%) and 92% (95% CI = 81.3-97.2%), respectively. There was no significant correlation between serum IGF-I concentration and duration of insulin treatment (r = 0.23, P = .089), insulin dosage (r = 0.14, P = .30), age (r = 0.16, P = .12), and pituitary volume (r = 0.40, P = .11), but a modest correlation was found between serum IGF-I concentration and body weight (r = 0.48, P < .0001).

CONCLUSIONS AND CLINICAL IMPORTANCE

Results support the use of serum IGF-I concentration as a screening test for acromegaly in diabetic cats that have clinical findings supportive of the disease.

Ultrasound microbubble contrast agents: fundamentals and application to gene and drug delivery

This review offers a critical analysis of the state of the art of medical microbubbles and their application in therapeutic delivery and monitoring. When driven by an ultrasonic pulse, these small gas bubbles oscillate with a wall velocity on the order of tens to hundreds of meters per second and can be deflected to a vessel wall or fragmented into particles on the order of nanometers. While single-session molecular imaging of multiple targets is difficult with affinity-based strategies employed in some other imaging modalities, microbubble fragmentation facilitates such studies. Similarly, a focused ultrasound beam can be used to disrupt delivery vehicles and blood vessel walls, offering the opportunity to locally deliver a drug or gene. Clinical translation of these vehicles will require that current challenges be overcome, where these challenges include rapid clearance and low payload. The technology, early successes with drug and gene delivery, and potential clinical applications are reviewed.

Retrospective Evaluation of Three Treatment Methods for Primary Hyperparathyroidism in Dogs

The medical records of 110 dogs treated for primary hyperparathyroidism were reviewed. Dogs were treated via parathyroidectomy (n=47), percutaneous ultrasound-guided ethanol ablation (n=15), or percutaneous ultrasound-guided heat ablation (n=48). Forty-five of 48 (94%) parathyroidectomies resulted in control of hypercalcemia for a median of 561 days. Thirteen of 18 (72%) ethanol ablation procedures resulted in control of hypercalcemia for a median of 540 days. Forty-four of 49 (90%) heat-ablation treatments resulted in control of hypercalcemia for a median of 581 days.

Mesoscale Iron Enrichment Experiments 1993-2005: Synthesis and Future Directions

Since the mid-1980s, our understanding of nutrient limitation of oceanic primary production has radically changed. Mesoscale iron addition experiments (FeAXs) have unequivocally shown that iron supply limits production in one-third of the world ocean, where surface macronutrient concentrations are perennially high. The findings of these 12 FeAXs also reveal that iron supply exerts controls on the dynamics of plankton blooms, which in turn affect the biogeochemical cycles of carbon, nitrogen, silicon, and sulfur and ultimately influence the Earth climate system. However, extrapolation of the key results of FeAXs to regional and seasonal scales in some cases is limited because of differing modes of iron supply in FeAXs and in the modern and paleo-oceans. New research directions include quantification of the coupling of oceanic iron and carbon biogeochemistry.

Optical bistability in nonlinear surface-plasmon polaritonic crystals

Nonlinear optical transmission through periodically nanostructured metal films (surface-plasmon polaritonic crystals) has been studied. The surface polaritonic crystals have been coated with a nonlinear polymer. The optical transmission of such nanostructures has been shown to depend on the control-light illumination conditions. The resonant transmission exhibits bistable behavior with the control-light intensity. The bistability is different at different resonant signal wavelengths and for different wavelengths of the control light. The effect is explained by the strong sensitivity of the surface-plasmon mode resonances at the signal wavelength to the surrounding dielectric environment and the electromagnetic field enhancement due to plasmonic excitations at the controlled light wavelengths.

Ultrasound detection and characterization of polycystic kidney disease in a mouse model

We sought to use ultrasonography to quantify renal size and echogenicity in a mouse model of polycystic kidney disease. We imaged 36 wild-type (WT) and juvenile cystic kidney (jck) mice by using a standard ultrasound unit and 10-5 MHz linear transducer. Mice were imaged at 3 (6 WT, 7 jck), 6 (7 WT, 5 jck), and 9 (6 WT, 5 jck) wk of age. Kidney length, width, and height were recorded for volume calculation. Sagittal images of both kidneys were recorded for assessment of intensity. Quantitative values were obtained from areas of similar depth and gain settings. Kidney and liver intensities were determined for calculation of their ratio. Representative histologic kidney sections were stained with hematoxylin and eosin and digitized for calculation of cyst number, mean cyst area, and percentage cystic area. We found that renal volume was greater in jck than WT mice at 3 (P < 0.0001), 6 (P < 0.0001), and 9 (P < 0.0001) wk of age. In addition, kidney intensity and kidney:liver ratio were higher in jck than WT mice at 3 (P < 0.002 for both parameters), 6 (P < 0.04), and 9 wk (P < 0.008). Kidneys with smaller mean cyst size and less percentage cystic space had higher intensity values. We therefore conclude that ultrasound measures of renal volume and intensity can noninvasively identify jck-affected mice as early as 3 wk of age. Cortical intensity is greater in jck versus WT mice and appears affected by percentage cyst area and mean cyst size.

Long-term trends in home advantage in professional team sports in North America and England (1876-2003)

Home advantage is quantitatively defined and calculated for each season since the start of the main professional sports in North America and England. Over 400,000 games are analysed. The leagues represented are the National League (1876-2002) and American League (1901-2002) for baseball, the National Hockey League (1917-2003) for ice hockey, the National Football League (1933-2002) for American football, the National Basketball Association (1946-2003) for basketball, and the four levels of professional football, formerly called the Football League, in England (1888-2003). Problems caused by unbalanced playing schedules are considered. The results are presented graphically to show long-term trends and sudden changes. The highest levels of home advantage for all sports were in their early years of existence. Home advantage in ice hockey, basketball and football in England has declined over the last two decades. In baseball there has been very little change over the last 100 years, with home advantage consistently lower than in other sports. There was a large drop in home advantage in football in England following the 7-year suspension of the league during the Second World War. The trends and changes provide some evidence that travel and familiarity contribute to home advantage, but little in support of crowd effects.

Pretreatment clinical and laboratory findings in dogs with primary hyperparathyroidism: 210 cases (1987–2004)

OBJECTIVE

To evaluate pretreatment clinical and laboratory findings in dogs with naturally occurring primary hyperparathyroidism.

DESIGN

Retrospective study.

ANIMALS

210 dogs with primary hyperparathyroidism and 200 randomly selected, age-matched control dogs that did not have primary hyperparathyroidism.

PROCEDURE

Medical records for dogs with primary hyperparathyroidism were reviewed for signalment; clinical features; and results of clinicopathologic testing, serum parathyroid hormone assays, and diagnostic imaging.

RESULTS

Mean age of the dogs with primary hyperparathyroidism was 11.2 years (range, 6 to 17 years). The most common clinical signs were attributable to urolithiasis or urinary tract infection (ie, straining to urinate, increased frequency of urination, and hematuria). Most dogs (149 [71%]) did not have any observable abnormalities on physical examination. All dogs had hypercalcemia, and most (136 [65%]) had hypophosphatemia. Overall, 200 of the 210 (95%) dogs had BUN and serum creatinine concentrations within or less than the reference range, and serum parathyroid hormone concentration was within reference limits in 135 of 185 (73%) dogs in which it was measured. Urolithiasis was identified in 65 (31 %) dogs, and urinary tract infection was diagnosed in 61 (29%). Mean serum total calcium concentration for the control dogs-was significantly lower than mean concentration for the dogs with primary hyperparathyroidism, but mean BUN and serum creatinine concentrations for the control dogs were both significantly higher than concentrations for the dogs with primary hyperparathyroidism.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that urolithiasis and urinary tract infection may be associated with hypercalcemia in dogs-with primary hyperparathyroidism, but that development of renal insufficiency is uncommon.

Comparison of 3 techniques for ureteroneocystostomy in cats

OBJECTIVE

To compare 3 techniques for ureteroneocystostomy in cats.

STUDY DESIGN

Experimental surgical study.

ANIMALS

Fifteen adult cats.

METHODS

Cats (15) had ureteroneocystostomy with ureteronephrectomy of the contralateral kidney: 5 cats had an intravesical mucosal apposition technique (modified Leadbetter-Politano; intravesical-MA group), 5 cats had extravesical ureteroneocystostomy (modified Lich Gregoir) using a simple continuous suture pattern (extravesical-SC group) and 5 cats had an extravesical technique using a simple interrupted suture pattern (extravesical-SI group). Renal function was evaluated by measuring serum creatinine concentration. Ultrasonographic assessment of the kidney and ureteroneocystostomy site was performed the day after surgery, twice weekly for 3 weeks and once weekly for the remainder of the study. Cats were euthanatized 50 days after surgery. The kidney and ureter removed at surgery, the remaining kidney, ureter, ureteroneocystostomy site, and bladder were examined histologically.

RESULTS

Two extravesical-SC cats were euthanatized because of azotemia and uroabdomen, and 1 died acutely at day 4 for unknown reasons. In the intravesical-MA and extravesical-SI cats, the serum creatinine concentration increased after surgery, peaking at a mean (+/-SD) of 9.4+/-2.4 mg/dL and 4.9+/-3.3 mg/dL on day 3, and decreasing to 3.4+/-5.7 mg/dL and 1.5+/-0.4 mg/dL on day 7, respectively. The extravesical-SI technique was associated with consistently lower serum creatinine concentrations for the first week after surgery compared with the other techniques. The mean serum creatinine concentration was within the reference range in cats in the intravesical-MA and extravesical-SI groups by days 10 and 5, respectively. Renal pelvic dilatation occurred in all cats but resolved more rapidly in cats after extravesical techniques. There was no significant difference in serum creatinine concentrations or renal pelvic dilation between the intravesical-MA and extravesical-SI techniques. Bladder mass height at the anastomosis site was significantly larger and persisted for longer with intravesical-MA technique.

CONCLUSION

An extravesical-SI technique is seemingly the choice for ureteroneocystostomy in cats with undilated ureters. Renal pelvic dilation on ultrasound examination should be expected after ureteroneocystostomy in cats.

CLINICAL RELEVANCE

An extravesical ureteroneocystostomy technique using a simple interrupted pattern for anastomosis should be considered in cats undergoing renal transplantation.

National Immunization Information Hotline: Calls concerning adverse events, 1998-2000

Data from the National Immunization Information Hotline (NIIH) concerning vaccine adverse event inquiries were analyzed from 1998 to 2000 (total n = 23,841 [public n = 14,330; health care professionals n = 9,511]). Approximately 20% of calls from the public from 1998 to 2000 concerned vaccine adverse events. These calls increased 199.5% from 1998 (n = 422) to 1999 (n = 1,264), then declined 12.4% from 1999 to 2000 (n = 1,107). A Lexus Nexus search showed that the number of news stories mentioning vaccine safety showed a similar pattern. Women were more likely to call the NIIH concerning vaccine adverse events than men, and persons 40-59 years old and persons 60 years old and over were less likely to call about vaccine adverse events than those 20-39 years. The parallel trends in news stories mentioning vaccine safety and calls to the NIIH concerning adverse events suggests that news stories may stimulate questions about vaccine safety. Understanding that news stories may elicit questions about vaccine adverse events and examining the characteristics of persons who ask vaccine adverse event questions may guide future informational interventions toward those most in need.

Surgical management of cricopharyngeal dysphagia in dogs: 14 cases (1989-2001)

OBJECTIVE

To determine outcome of and complications associated with cricopharyngeal myotomy or myectomy for treatment of cricopharyngeal dysphagia (CPD) in dogs.

DESIGN

Retrospective study.

ANIMALS

14 dogs.

PROCEDURE

Medical records of dogs with CPD that underwent cricopharyngeal myotomy or myectomy were examined. Follow-up information was obtained through telephone interviews with owners and referring veterinarians and clinical examinations when feasible.

RESULTS

16 surgical procedures were performed on the 14 dogs. Dysphagia was completely resolved immediately after surgery in 1 dog, and clinical signs did not recur (follow-up time of 8 years); a second dog also had immediate complete resolution of dysphagia, but follow-up time was only 10 days. Three dogs had transient complete resolution with a mean time to recurrence of dysphagia of 12.3 weeks (range, 2 to 36 weeks). Three dogs had permanent partial resolution. Six dogs had no improvement after surgery. Eight of the 14 dogs were euthanatized because of problems related to CPD, including persistent dysphagia (n = 8) and aspiration pneumonia (5).

CONCLUSIONS AND CLINICAL RELEVANCE

The failure rate for dogs undergoing surgical treatment of CPD may be high, particularly if concurrent aspiration pneumonia or malnutrition is not addressed prior to surgery. For those dogs with concurrent diseases, more aggressive medical management, such as enteral tube feeding, may be warranted rather than surgery. In dogs with CPD complicated by other anatomic or functional conditions, such as myasthenia gravis, laryngeal paralysis, and esophageal stricture, surgery may also not be indicated.

Near-field imaging of ultrathin magnetic films with in-plane magnetization

A new approach to near-field magneto-optical imaging was developed capable of visualization of in-plane magnetization of ultrathin magnetic structures. The approach relies on the magneto-optical effect specific for thin magnetic layers and employs near-field transmission measurements of longitudinal and/or transverse magneto-optical effect arising from the presence of thin film interfaces. The near-field magneto-optical contrast of in-plane domain structure of ultrathin Co film has been demonstrated in different polarization configurations.

Attitudes, practices, and preferences of pediatricians regarding initiation of hepatitis B immunization at birth

OBJECTIVES

To explore practices and attitudes of pediatricians toward administration of the first dose of hepatitis B vaccine to infants, and to identify factors influencing the decision of pediatricians to initiate immunization at birth versus at 1 to 2 months of age.

METHODS

A random sample of 600 pediatricians obtained from the American Academy of Pediatrics membership database was surveyed by mail.

RESULTS

Three hundred eighty (68%) of the 563 pediatricians who were located responded to the survey. Of these 380 pediatricians, 279 provided routine immunizations to children. Of the 270 pediatricians who vaccinated children with hepatitis B vaccine and indicated their practice regarding the birth dose, 50% offered the first dose of hepatitis B vaccine at birth to all infants; the rest either offered the vaccine at birth only to infants of hepatitis B surface antigen-positive mothers and mothers whose serostatus is unknown, or did not offer the birth dose to any infants at all. Practicing in the inner city, working for a medical school or government hospital, and living in a state with universal immunization supply policies were associated with the respondent giving the birth dose. The strongest perceived barriers to giving the birth dose in the hospital were the difficulty tracking these vaccines (39%), the increased cost (27%), and the lack of reimbursement from insurance companies (26%). If a combination vaccine that includes hepatitis B; diphtheria, tetanus, pertussis (diphtheria and tetanus toxoids and acellular pertussis vaccine); and polio (inactivated poliovirus vaccine) antigens become available in the near future, then 38% of physicians who currently give the birth dose to all infants would prefer to wait until 2 months of age to initiate hepatitis B immunization.

CONCLUSIONS

Efforts to achieve high implementation of hepatitis B birth dose administration may falter once a hepatitis B-containing pentavalent combination vaccine becomes available. Programmatic efforts should ensure prevention of perinatal hepatitis B virus transmission through universal prenatal hepatitis B surface antigen screening and immunoprophylaxis of high-risk newborn infants.

A lower incidence of left-handed writing among young adults in Bulgaria than in the USA

The incidence of left-handed writing among 590 young Bulgarian adults was 6.4%, significantly lower than that reported in two studies of students in the United States. Of those writing with the right hand, 10.8% stated that they had been forced to change their preferred hand for writing. The parents of the Bulgarian sample had a similar low incidence of left-handed writing (5.9%). Left-handed writing was almost three times more likely if one or both of the parents wrote with the left hand.