Developmental health of Canadian kindergarten children with teacher-reported asthma between 2010 and 2015: A population-level cross-sectional study.

Asthma can impact children's quality of life. It is unclear how asthma is associated with the developmental health (i.e. a broad range of skills and abilities associated with growth and development) of young children at school entry. The goals of this cross-sectional, population-level study were to: (1) investigate the association between teacher-reported asthma and children's concurrent indicators of developmental health (developmental vulnerability); and (2) explore whether school absences and functional impairments modified this association. Participants were a Canadian population-based sample of 564 582 kindergarten children (Mage = 5.71 years, SD = 0.32, 51.3 % male) with data on the Early Development Instrument (EDI) collected between 2010 and 2015. Adjusted binary logistic regressions were conducted to address the objectives. From the sample, 958 (0.2 %) children were identified as having a diagnosis of asthma. These children were absent on average 9.4 days and 53.5 % had functional impairments (vs. 6.7 days absent and 15.9 % with functional impairments in children without asthma). After controlling for demographic characteristics, children with asthma had between 1.51 and 2.42 higher odds of being developmentally vulnerable. Only the presence of functional impairments modified this relationship and only for physical health and well-being. In this large, population-based sample of Canadian kindergarten children, few teachers reported knowledge of their students' asthma diagnosis. Among teacher-reported cases, asthma was a risk factor for developmental vulnerability in the domain of physical health and well-being only. Functional impairments may therefore be more detrimental for child development at school entry than asthma alone.

Teaching bone marrow procedures at pelvic and sternal sites: a high fidelity anatomy simulation.

The bone marrow aspirate and biopsy procedure are fundamental to the diagnosis of many hematologic pathologies. We describe a hands-on, anatomy-based workshop that allows learners to practice bone marrow procedures on cadavers. Notably, participants learned how to perform sternal aspirates: a procedure rarely performed in real-life practice. Learners valued the experience and described increased comfort with the procedure after the workshop. This workshop provides a valuable opportunity for trainees to learn a procedural skill in a safe, high fidelity environment. Given its hands-on nature, residency training programs could also adapt it for direct observation and trainee assessment.

La ponction et la biopsie de la moelle osseuse sont d'une importance capitale pour le diagnostic de nombreuses pathologies hématologiques. Nous décrivons un atelier pratique, axé sur l'anatomie, qui permet aux apprenants de faire des prélèvements de moelle osseuse sur des cadavres. Les participants ont notamment appris à effectuer des ponctions sternales, une intervention qui est plutôt rare dans la pratique réelle. Ils indiquent avoir apprécié l'atelier, grâce auquel ils ont pris confiance pour pratiquer la technique. L'atelier est une occasion précieuse pour les apprenants d'acquérir une habileté technique dans un environnement sûr et haute fidélité. Étant donné son caractère pratique, les programmes de résidence pourraient aussi l'adapter dans un contexte d'observation directe et d'évaluation.

PF-06804103, A Site-specific Anti-HER2 Antibody-Drug Conjugate for the Treatment of HER2-expressing Breast, Gastric, and Lung Cancers.

The approval of ado-trastuzumab emtansine (T-DM1) in HER2+ metastatic breast cancer validated HER2 as a target for HER2-specific antibody-drug conjugates (ADC). Despite its demonstrated clinical efficacy, certain inherent properties within T-DM1 hamper this compound from achieving the full potential of targeting HER2-expressing solid tumors with ADCs. Here, we detail the discovery of PF-06804103, an anti-HER2 ADC designed to have a widened therapeutic window compared with T-DM1. We utilized an empirical conjugation site screening campaign to identify the engineered ĸkK183C and K290C residues as those that maximized in vivo ADC stability, efficacy, and safety for a four drug-antibody ratio (DAR) ADC with this linker-payload combination. PF-06804103 incorporates the following novel design elements: (i) a new auristatin payload with optimized pharmacodynamic properties, (ii) a cleavable linker for optimized payload release and enhanced antitumor efficacy, and (iii) an engineered cysteine site-specific conjugation approach that overcomes the traditional safety liabilities of conventional conjugates and generates a homogenous drug product with a DAR of 4. PF-06804103 shows (i) an enhanced efficacy against low HER2-expressing breast, gastric, and lung tumor models, (ii) overcomes in vitro- and in vivo-acquired T-DM1 resistance, and (iii) an improved safety profile by enhancing ADC stability, pharmacokinetic parameters, and reducing off-target toxicities. Herein, we showcase our platform approach in optimizing ADC design, resulting in the generation of the anti-HER2 ADC, PF-06804103. The design elements of identifying novel sites of conjugation employed in this study serve as a platform for developing optimized ADCs against other tumor-specific targets.

Systematic review of fondaparinux for heparin-induced thrombocytopenia: When there are no randomized controlled trials.

BACKGROUND: Fondaparinux is commonly used for treatment of heparin-induced thrombocytopenia (HIT) despite lack of approval for this indication. High quality randomized controlled trials of this agent are unlikely to be forthcoming. OBJECTIVES: The objective of this systematic review is to update the literature on the efficacy and safety of fondaparinux for treatment of confirmed and probable HIT based on the available evidence. METHODS: Primary articles were identified using Web of Science and PubMed database searches for English-language studies from January 2006 to November 2017. Selected studies enrolled consecutive adult patients who received fondaparinux as the primary anticoagulant to treat acute HIT; confirmed the diagnosis by serological testing with a serotonin-release assay; heparin-induced platelet activation assay or enzyme-linked immunosorbent assay; provided clinical criteria used to define HIT and reported clinically important outcomes. RESULTS: A total of 9 studies were identified with 154 HIT positive patients. Ten experienced a new thrombotic event while receiving fondaparinux (6.5%, 95% CI, 3.4 to 11.7%) and 26 experienced major bleeding (16.9%, 95% CI, 11.7 to 23.6%). Mortality due to thrombosis or bleeding was reported in 5 patients (3.2%, 95% CI, 1.2 to 7.6%). CONCLUSIONS: Fondaparinux appears to be an effective and safe anticoagulant for treatment of acute HIT despite the absence of randomized trials. Caution should exercised when using fondaparinux in patients with renal insufficiency.

Inflammatory Cell Findings in the Female Rabbit Heart and Stress-associated Exacerbation with Handling and Procedures Used in Nonclinical Studies.

Despite the use of rabbits in biomedical research, including regulatory toxicology and cardiovascular studies, little data exist on heart findings in this species. This study was designed to document myocardial findings in female rabbits and the impact of study-related procedures typical for vaccine toxicology studies. One hundred and forty 6- to 8-month-old female New Zealand White rabbits were divided equally into 2 groups, high and low study procedure groups (group 1 and group 2, respectively). All animals received intramuscular (IM) injections of sterile saline every 2 weeks for 5 times and were necropsied 2 days after the final IM injection. Clinical chemistry, hematology, and urinalysis were evaluated. Blood for stress biomarkers (norepinephrine, epinephrine, cortisol, and corticosterone), C-reactive protein, cardiac troponin I, and creatine kinase were collected at time 0 (just before dose administration) and then at 4, 24, and 48 hr after dose administration in group 1 only. Hearts were assessed histologically. Focal to multifocal minimal inflammatory cell infiltrates were common (∼80%), particularly in the left ventricle and interventricular septum, and were similar to the types of infiltrates identified in other laboratory animal species. Additionally, study-related procedures elevated serum stress biomarkers and exacerbated the frequency and severity of myocardial inflammatory cell infiltrates.

Demonstration of the preclinical correlate of protection for Staphylococcus aureus clumping factor A in a murine model of infection.

The Staphylococcus aureus virulence factor clumping factor A (ClfA) is a component of an investigational S. aureus prophylactic vaccine. ClfA enables S. aureus to bind to fibrinogen and platelets during the initial stages of invasive disease. Here we demonstrate that ectopic expression of ClfA is sufficient to render nonpathogenic Lactococcus lactis lethal in a murine model of systemic infection. In contrast, L. lactis expressing ClfAY338A, which cannot bind fibrinogen, did not cause death in the mice. Pathogenicity was also prevented by immunization with ClfA. This model was then used to define a preclinical correlate of protection by measuring functional antibody in a S. aureus fibrinogen binding inhibition assay (FBI) and correlating that titer with protective outcomes. Although many humans have pre-existing antibodies that bind to ClfA, only sera with a threshold functional titer in the FBI were protective in this preclinical model. This confirms that fibrinogen binding is critical for ClfA-mediated pathogenesis and demonstrates that functional antibodies against ClfA are sufficient to protect against ClfA-mediated pathogenesis in vivo, enabling the definition of a preclinical correlate of protection for ClfA-containing vaccines based on FBI titer.

Phenotype of TPBG Gene Replacement in the Mouse and Impact on the Pharmacokinetics of an Antibody-Drug Conjugate.

The use of predictive preclinical models in drug discovery is critical for compound selection, optimization, preclinical to clinical translation, and strategic decision-making. Trophoblast glycoprotein (TPBG), also known as 5T4, is the therapeutic target of several anticancer agents currently in clinical development, largely due to its high expression in tumors and low expression in normal adult tissues. In this study, mice were engineered to express human TPBG under endogenous regulatory sequences by replacement of the murine Tpbg coding sequence. The gene replacement was considered functional since the hTPBG knockin (hTPBG-KI) mice did not exhibit clinical observations or histopathological phenotypes that are associated with Tpbg gene deletion, except in rare instances. The expression of hTPBG in certain epithelial cell types and in different microregions of the brain and spinal cord was consistent with previously reported phenotypes and expression patterns. In pharmacokinetic studies, the exposure of a clinical-stage anti-TPBG antibody-drug conjugate (ADC), A1mcMMAF, was lower in hTPBG-KI versus wild-type animals, which was evidence of target-related increased clearance in hTPBG-KI mice. Thus, the hTPBG-KI mice constitute an improved system for pharmacology studies with current and future TPBG-targeted therapies and can generate more precise pharmacokinetic and pharmacodynamic data. In general the strategy of employing gene replacement to improve pharmacokinetic assessments should be broadly applicable to the discovery and development of ADCs and other biotherapeutics.

Long-term tumor regression induced by an antibody-drug conjugate that targets 5T4, an oncofetal antigen expressed on tumor-initiating cells.

Antibody-drug conjugates (ADC) represent a promising therapeutic modality for the clinical management of cancer. We sought to develop a novel ADC that targets 5T4, an oncofetal antigen expressed on tumor-initiating cells (TIC), which comprise the most aggressive cell population in the tumor. We optimized an anti-5T4 ADC (A1mcMMAF) by sulfydryl-based conjugation of the humanized A1 antibody to the tubulin inhibitor monomethylauristatin F (MMAF) via a maleimidocaproyl linker. A1mcMMAF exhibited potent in vivo antitumor activity in a variety of tumor models and induced long-term regressions for up to 100 days after the last dose. Strikingly, animals showed pathologic complete response in each model with doses as low as 3 mg antibody/kg dosed every 4 days. In a non-small cell lung cancer patient-derived xenograft model, in which 5T4 is preferentially expressed on the less differentiated tumor cells, A1mcMMAF treatment resulted in sustained tumor regressions and reduced TIC frequency. These results highlight the potential of ADCs that target the most aggressive cell populations within tumors, such as TICs. In exploratory safety studies, A1mcMMAF exhibited no overt toxicities when administered to cynomolgus monkeys at doses up to 10 mg antibody/kg/cycle × 2 and displayed a half-life of 5 days. The preclinical efficacy and safety data established a promising therapeutic index that supports clinical testing of A1mcMMAF.

Comparison of psychophysical, electrophysiological, and fMRI assessment of visual contrast responses in patients with schizophrenia.

Perception has been identified by the NIMH-sponsored Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia (CNTRICS) group as a useful domain for assessing cognitive deficits in patients with schizophrenia. Specific measures of contrast gain derived from recordings of steady-state visual evoked potentials (ssVEP) have demonstrated neural deficits within the visual pathways of patients with schizophrenia. Psychophysical measures of contrast sensitivity have also shown functional loss in these patients. In the current study, functional magnetic resonance imaging (fMRI) was used in conjunction with ssVEP and contrast sensitivity testing to elucidate the neural underpinnings of these deficits. During fMRI scanning, participants viewed 1) the same low and higher spatial frequency stimuli used in the psychophysical contrast sensitivity task, at both individual detection threshold contrast and at a high contrast; and 2) the same stimuli used in the ssVEP paradigm, which were designed to be biased toward either the magnocellular or parvocellular visual pathway. Patients showed significant impairment in contrast sensitivity at both spatial frequencies in the psychophysical task, but showed reduced occipital activation volume for low, but not higher, spatial frequency at the low and high contrasts tested in the magnet. As expected, patients exhibited selective deficits under the magnocellular-biased ssVEP condition. However, occipital lobe fMRI responses demonstrated the same general pattern for magnocellular- and parvocellular-biased stimuli across groups. These results indicate dissociation between the fMRI measures and the psychophysical/ssVEP measures. These latter measures appear to have greater value for the functional assessment of the contrast deficits explored here.

Drug design structural alert: formation of trifluoroacetaldehyde through N-dealkylation is linked to testicular lesions in rat.

In the process of drug design, it is important to consider potential structural alerts that may lead to toxicosis. This work illustrates how using trifluoroethane as a part of a novel chemical entity led to cytochrome P450 - mediated N-dealkylation and the formation of trifluoroacetaldehyde, a known testicular toxicant, in exploratory safety studies in rats. Testicular toxicosis was noted microscopically in a dose-dependent manner as measured by testicular spermatocytic degeneration and necrosis and excessive intratubular cellular debris in the epididymis. This apparent toxic effect correlated well with the dose-dependent formation of trifluoroacetaldehyde, identified from in vitro rat liver microsome metabolism studies. A similar safety study performed with an N-tetrazole substitution in place of the N-trifluoroethane showed no evidence of testicular injury, implicating further the role of trifluoroacetaldehyde in the testicular lesion observed. These results highlight the relevance of early metabolic and safety testing in assessing potential structural alerts in drug design.

Influence of pupil size and other test variables on visual function assessment using visual evoked potentials in normal subjects.

The purpose of this study was to assess the influence of pupil size and optical blur on measurements obtained with isolated-check visual evoked potential (icVEP). Two stimulus conditions of icVEP, +15 and -15% contrasts, were studied in normal subjects with normal (N), miotic (M), and dilated (D) pupils. The effects of optical blur were studied in subjects with normal pupil. Response to visual stimuli was quantified by a signal-to-noise (SNR) ratio. In 30 normal subjects, the mean age was 26.0 +/- 3.4 years. Mean pupil diameters were N = 4.2 +/- 0.6 mm, M = 2.7 +/- 0.6 mm, and D = 7.3 +/- 0.9 mm. For both +15 and -15% contrast levels, mean SNR values were reduced for dilated and constricted pupils when compared with normal pupils. Mean SNR values for optical blur with a +2 or +3 diopter lens placed over the distance correction were reduced when compared with SNR measurements obtained with best-corrected visual acuity under both +15 and -15% contrast levels. Statistical significance was found in comparisons of N versus M (P < 0.001) and N versus D (P = 0.002) for +15 and -15% contrast conditions, respectively. No statistical difference was seen for M versus D (P = -0.435). The effect of optical blur was statistically significant when compared to the normal pupils with best-corrected vision (P < 0.001). No statistically significant difference was found comparing +2 and +3 diopters lenses for optical blur testing. Visual evoked potential values are influenced by pupillary constriction and dilation, as well as optical blur. When obtaining icVEP measurements, the influence of pupil size and optical blur should be kept in mind for accurate interpretations.

CJ-13610, an orally active inhibitor of 5-lipoxygenase is efficacious in preclinical models of pain.

Zileuton, a redox and iron chelator 5-lipoxygenase (5-LOX) inhibitor and, leukotriene receptor antagonists are presently used clinically in the long term treatment of asthma. Recent data implicate 5-LOX pathway in pain signaling. We report 5-LOX expression in the central nervous system (CNS) and analyze the pain efficacy of a new class of non redox, non iron chelating 5-LOX inhibitor. CJ-13610, 4-(3-(4-(2-methyl-1H-imidazol-1-yl) phenylthio) phenyl)-tetrahydro-2H-pyran-4-carboxamide, demonstrated antihyperalgesic activity in inflammatory pain models including the acute carrageenan model and the chronic inflammatory model using complete Freund's adjuvant. Following complete Freund's adjuvant stimulus leukotrieneB(4) concentration in the brain was elevated (9+/-1 ng/g, mean+/-S.E.M.) by about 3 times that of the control group (3+/-0.11, mean+/-S.E.M.). Hyperalgesia and leukotrieneB(4) concentration were both reversed following CJ-13610 treatment. Furthermore, we demonstrate CJ-13610 efficacy against osteoarthritis like pain using the rat medial meniscal transection model. CJ-13610 at oral doses of 0.6, 2 and 6 mg/kg/day reversed two modalities of pain in this model; tactile allodynia and weight bearing differential. Taken together, these data suggest that 5-LOX pathway and the leukotriene products are important mediators of pain.

Novel tight-binding inhibitory factor-kappaB kinase (IKK-2) inhibitors demonstrate target-specific anti-inflammatory activities in cellular assays and following oral and local delivery in an in vivo model of airway inflammation.

Nuclear factor-kappaB (NF-kappaB) is one of the major families of transcription factors activated during the inflammatory response in asthma and chronic obstructive pulmonary disease. Inhibitory factor-kappaB kinase 2 (IKK-2) has been shown to play a pivotal role in cytokine-induced NF-kappaB activation in airway epithelium and in disease-relevant cells. Nevertheless, the potential toxicity of specific IKK-2 inhibitors may be unacceptable for oral delivery in chronic obstructive pulmonary disease. Therefore, local delivery to the lungs is an attractive alternative that warrants further exploration. Here, we describe potent and selective small-molecule IKK-2 inhibitors [8-(5-chloro-2-(4-methylpiperazin-1-yl)isonicotinamido)-1-(4-fluorophenyl)-4,5-dihydro-1H-benzo[g]indazole-3-carboxamide (PHA-408) and 8-(2-(3,4-bis(hydroxymethyl)-3,4-dimethylpyrrolidin-1-yl)-5-chloroisonicotinamido)-1-(4-fluorophenyl)-4,5-dihydro-1H-benzo-[g]indazole-3-carboxamide (PF-184)] that are competitive for ATP have slow off-rates from IKK-2 and display broad in vitro anti-inflammatory activities resulting from NF-kappaB pathway inhibition. Notably, PF-184 has been designed to have high systemic clearance, which limits systemic exposure and maximizes the effects locally in the airways. We used an inhaled lipopolysaccharide-induced rat model of neutrophilia to address whether inhibiting NF-kappaB activation locally within the airways would show anti-inflammatory effects in the absence of systemic exposure. PHA-408, a low-clearance compound previously shown to be efficacious orally in a rodent model of arthritis, dose-dependently attenuated inhaled lipopolysaccharide-induced cell infiltration and cytokine production. Interestingly, PF-184 produced comparable dose-dependent anti-inflammatory activity by intratracheal administration and was as efficacious as intratracheally administered fluticasone propionate (fluticasone). Together, these results support the potential therapeutic utility of IKK-2 inhibition in inflammatory pulmonary diseases and demonstrate anti-inflammatory efficacy of an inhaled IKK-2 inhibitor in a rat airway model of neutrophilia.

Novel electrophysiological instrument for rapid and objective assessment of magnocellular deficits associated with glaucoma.

PURPOSE: To introduce a rapid and objective electrophysiological technique that can assess visual function in the magnocellular pathway, which is thought to be affected in early-stage glaucoma. METHODS: Low-contrast bright or dark isolated-checks were luminance-modulated against a static background at 10 Hz in order to drive preferentially the magnocellular ON or OFF pathway. Visual evoked potentials were recorded during 1-s epochs of stimulation and responses at the stimulus frequency were measured. Artifact rejection features ensured that eight valid runs were obtained per eye. Signal-to-noise ratios (SNR) were derived based on a multivariate statistic. In order to demonstrate its functionality, a small group of patients with glaucoma (N = 18, Snellen acuity of 20/30 or better) and control observers (N = 16) were tested. A participant failed the test if either eye yielded an SNR < or = 1. Receiver-operating-characteristic curve analysis was used to estimate the accuracy of group classification. RESULTS: The instrument was found to elicit reliable responses from control observers. For the 15% bright condition, all control observers yielded significant isolated-check VEPs (icVEPs), whereas the majority of patients failed to do so, indicating significant losses in central visual function. This condition produced the highest classification accuracy (94%), followed by the 10% dark condition (91%). CONCLUSIONS: Both ON and OFF divisions of the magnocellular pathway can be assessed rapidly through the application of the icVEP technique. This measure of central visual function may be of value in the detection of glaucomatous deficits and may complement tests of peripheral function.