Rational Design of Benzobisheterocycle Metallo-β-Lactamase Inhibitors: A Tricyclic Scaffold Enhances Potency against Target Enzymes

Antimicrobial resistance is a global public health threat. Metallo-β-lactamases (MBLs) inactivate β-lactam antibiotics, including carbapenems, are disseminating among Gram-negative bacteria, and lack clinically useful inhibitors. The evolving bisthiazolidine (BTZ) scaffold inhibits all three MBL subclasses (B1-B3). We report design, synthesis, and evaluation of BTZ analogues. Structure-activity relationships identified the BTZ thiol as essential, while carboxylate is replaceable, with its removal enhancing potency by facilitating hydrophobic interactions within the MBL active site. While the introduction of a flexible aromatic ring is neutral or detrimental for inhibition, a rigid (fused) ring generated nM benzobisheterocycle (BBH) inhibitors that potentiated carbapenems against MBL-producing strains. Crystallography of BBH:MBL complexes identified hydrophobic interactions as the basis of potency toward B1 MBLs. These data underscore BTZs as versatile, potent broad-spectrum MBL inhibitors (with activity extending to enzymes refractory to other inhibitors) and provide a rational approach to further improve the tricyclic BBH scaffold.

Early Communicative Development in Williams Syndrome: A Longitudinal Case Study

Individuals with Williams Syndrome (WS) have a specific and atypical neuropsychological profile, where language is above what is expected for their mental age, although it shows a late onset. There exists only one longitudinal study in infants younger than 20 months old with WS about early language precursors (joint attention, referential and instrumental behaviors, pointing gesture, verbal tags). The aim of this investigation is to evaluate these precursors in a baby with WS (8 to 18 months). Seven sessions of systematic observation were performed (six at baby's home, one at the Early Childhood Assistance center). The Battelle Developmental Inventory was used to evaluate the baby's development in two occasions (12 and 18 months). The results show an atypical development, and he is 5-6 months under what is expected for his chronological age. Attention towards objects prevails over preference for faces, but this one tends to increase. The pointing gesture does not emerge at the end of the observation period and therefore follows the first words that appear. The implications for the comprehension of the early linguistic profile in WS are discussed, as well as the implications for specific intervention strategies in the context of early childhood care.

Gaze Following as an Early Diagnostic Marker of Autism in a New Word Learning Task in Toddlers

The aim was to test the use of eye-tracking methodology for the early detection of ASD in a task of association between unfamiliar objects and pseudowords. Significant differences were found between ASD (n = 57) and TD (n = 57) Spanish speaking toddlers in the number and time of fixation. The TD children showed more and longer fixations on eyes and mouth while the ASD children attended almost exclusively to objects, making it difficult to integrate lexical and phonological information. Moreover, the TD toddlers looked at the mouth when the pseudoword was produced while the ASD toddlers did not. Gaze fixation on eyes and mouth during word learning recorded by eye-tracking may be used as a biomarker for the early diagnosis of ASD.

Late phonological development in Williams syndrome

Williams syndrome is a neurodevelopmental genetic disorder characterized by a unique phenotype, including mild to moderate intellectual disability and an uneven neuropsychological profile of relative strengths and weaknesses. Language structure components (i.e., phonology, morphosyntax, and vocabulary) have been considered an area of specific ability compared to pragmatic language use. However, research on phonological development in Williams syndrome is very scarce, and it suggests atypical patterns. Therefore, the aim of the present study was to explore the profiles of late phonological development in Spanish-speaking children, adolescents, and adults with Williams syndrome, based on the analysis of five classes of processes (Syllable Structure, Substitution, Omission, Assimilation, and Addition) in spontaneous speech. The phonological profiles of seven children (aged 3-8 years), and seven adolescents and young adults (aged 14-25 years) with Williams syndrome were compared with two normative groups of typically developing (TD) children at different stages of late phonological development (aged 3 and 5 years). The frequency of phonological processes in the group of children with Williams syndrome was similar to that of 3-year-old TD children, which suggests that they would be in the first stage of late phonological development (expansion stage). The group of older individuals with Williams syndrome showed a much lower frequency of processes, similar to that of 5-year-old TD children in the last stage of phonological development (resolution stage). However, their phonological processes appeared to be persistent and independent of chronological age. Furthermore, asynchronies in quantitative and qualitative profiles (relative frequency) indicated atypical and complex trajectories in late phonological development, which cannot be described as simply delayed or protracted. Remarkable individual differences were observed, especially in the group of adolescents and adults with Williams syndrome, although the majority of cases conformed to the modal profiles of their groups. A major tendency for Omission, including final consonant deletion, may be considered atypical and specific to Williams syndrome at all ages. The results of the present study raise the need for continued and appropriate phonological assessment and treatment for people with Williams syndrome across the lifespan.

Health-related quality of life of X-linked hypophosphatemia in Spain

BACKGROUND

Health-related quality of life (HRQoL) of patients with X-linked hypophosphatemia (XLH) is lower than that of both the general population and the patients with other chronic diseases, mainly due to diagnostic delay, treatment difficulties, poor psychosocial support, and problems with social integration. Early diagnosis and optimal treatment are paramount to control the disease in patients with XLH, avoid complications, and maintain or improve their HRQoL. We, therefore, analyzed the HRQoL of pediatric and adult patients with XLH treated with conventional therapy in Spain.

RESULTS

We used several versions of the EuroQol-5 dimensions (EQ-5D) instrument according to the age of patients with XLH. Then we compared the HRQoL of patients to that of the general Spanish population. Children with XLH (n = 21) had moderate problems in walking about (61.9%), washing or dressing themselves (9.52%), and performing their usual activities (33.33%). They also felt moderate pain or discomfort (61.9%) and were moderately anxious or depressed (23.81%). Adults with XLH (n = 29) had lower HRQoL, with problems in walking (93%, with 3.45% unable to walk independently), some level of pain (86%, with 3.45% experiencing extreme pain), problems with their usual activities (80%) and self-care (> 50%), and reported symptoms of anxiety and/or depression (65%). There were important differences with the general Spanish population.

CONCLUSIONS

XLH impacts negatively on physical functioning and HRQoL of patients. In Spanish patients with XLH, the HRQoL was reduced despite conventional treatment, clearly indicating the need to improve the therapeutic approach to this disorder.

Oral Narrative Intervention by Tele-Practice in a Case with Developmental Language Disorder

BACKGROUND

A narrative requires the integration and management of linguistic and cognitive skills. It has been observed that children with Developmental Language Disorder (DLD) have difficulties in narrating stories. This research proposes an intervention in a case of a child 9 years and 2 months old with DLD, with the aim of improving his oral narrative skills through a retelling task via telepractice.

METHODS

In the evaluation, standardized tests have been used and a 'remembering a story' task, with a story titled The Lost Backpack, elaborated by one of the authors. Narratives were elicited in two sessions, and were transcribed, coded, and analysed using the Child Language Data Exchange System CHILDES Project tool. The participant received a total of 10 sessions through the Skype platform, which included intervention-addressed explicit instruction about the narrative structure and the use of discourse markers to improve cohesion in story retelling.

RESULTS

Significant changes were observed in the retelling of the story at microstructure and macrostructure levels: an increase of the Mean Length of Utterance (MLU), Types and Tokens, specific vocabulary, discourse markers and the recall of events.

CONCLUSIONS

These results demonstrate the effectiveness of intervention in narrative skills through the oral retelling of a story with visual support via tele-practice.

Assessing Phonological Profiles in Children and Adolescents With Down Syndrome: The Effect of Elicitation Methods

In the context of comparing linguistic profiles across neurodevelopmental disorders, Down syndrome (DS) has captured growing attention for its uneven profile. Although specific weaknesses in grammatical and phonological processing have been reported, research evidence on phonological development remains scarce, particularly beyond early childhood. The purpose of this study was to explore the phonological profiles of children and adolescents with Down syndrome. The profiles were based on the frequency and relative proportion of the processes observed by classes, and they were compared to those of typically developing preschool children of similar verbal age. A complementary goal was to assess the effect of two different methods of elicitation: a test of articulation and spontaneous speech sampling. Finally, intergroup and intragroup differences in full match percentages between three positions at syllable-level (complex onset, medial coda, and final coda) were assessed. The results of the present study confirmed that the frequency of phonological processes in children and adolescents with DS is atypically high and is above what is expected for lexical age and at the same level as grammatical age. Highly increased frequency of processes, consistent in all kinds of processes and positions at the syllable-level, and asynchronous with verbal age and mental age suggest atypical developmental trajectories of phonological development in the Down syndrome population.

Gaze Following and Pupil Dilation as Early Diagnostic Markers of Autism in Toddlers

Background: Children with autism spectrum disorder (ASD) show certain characteristics in visual attention. These may generate differences with non-autistic children in the integration of relevant social information to set the basis of communication. Reliable and objective measurement of these characteristics in a language learning context could contribute to a more accurate early diagnosis of ASD. Gaze following and pupil dilation are being studied as possible reliable measures of visual attention for the early detection of ASD. The eye-tracking methodology allows objective measurement of these biomarkers. The aim of this study is to determine whether measurements of gaze following and pupillary dilation in a linguistic interaction task are potential objective biomarkers for the early diagnosis of ASD. Method: A group of 20 children between 17 and 24 months of age, made up of 10 neurotypical children (NT) and 10 children with an increased likelihood of developing ASD were paired together according to chronological age. A human face on a monitor pronounced pseudowords associated with pseudo-objects. Gaze following and pupil dilation were registered during the task These measurements were captured using eye-tracking methodology. Results: Significant statistical differences were found in the time of gaze fixation on the human face and on the object, as well as in the number of gazes. Children with an increased possibility of developing ASD showed a slightly higher pupil dilation than NT children. However, this difference was not statistically significant. Nevertheless, their pupil dilation was uniform throughout the different periods of the task while NT participants showed greater dilation on hearing the pseudoword. Conclusions: The fixing and the duration of gaze, objectively measured by a Tobii eye-tracking system, could be considered as potential biomarkers for early detection of ASD. Additionally, pupil dilation measurement could reflect differential activation patterns during word processing in possible ASD toddlers and NT toddlers.

Manufacturing parameter analysis for alumina coating on steel substrate by automated image processing of isolated splats samples

Thermal spray technology, which involves the Atmospheric Plasma Spraying (APS), encompasses a category of coating processes that supply surface properties to protect or improve the performance of a substrate or component. The coating produced by this technology is built by overlapped splats, whose morphology determines the coating properties. In the same way, the splats obtained in a separated distribution by interposing a perforated mask but using the same thermal spray parameters, has a relationship with the overlapped splats inside the coating. The samples with isolated splats have the advantage of being faster and cheaper to generate and analyse. This article analyses alumina plasma-sprayed splats on steel substrates by image processing techniques, which recognize individual splats and their corresponding morphology (doughnut and pancake) parameters. These parameters allow the user to efficiently classify the splats. After that classification, a quality control can be implemented by comparison between the original and checked sample of isolated splats and a new sample obtained during a small interruption in the normal operation. Additionally, these parameters obtained in an automated way can be used to evaluate the effect of different selections of spraying process parameters.

Explicit Oral Narrative Intervention for Students with Williams Syndrome

Narrative skills play a crucial role in organizing experience, facilitating social interaction and building academic discourse and literacy. They are at the interface of cognitive, social, and linguistic abilities related to school engagement. Despite their relative strengths in social and grammatical skills, students with Williams syndrome (WS) do not show parallel cognitive and pragmatic performance in narrative generation tasks. The aim of the present study was to assess retelling of a TV cartoon tale and the effect of an individualized explicit instruction of the narrative structure. Participants included eight students with WS who attended different special education levels. Narratives were elicited in two sessions (pre and post intervention), and were transcribed, coded and analyzed using the tools of the CHILDES Project. Narratives were coded for productivity and complexity at the microstructure and macrostructure levels. Microstructure productivity (i.e., length of narratives) included number of utterances, clauses, and tokens. Microstructure complexity included mean length of utterances, lexical diversity and use of discourse markers as cohesive devices. Narrative macrostructure was assessed for textual coherence through the Pragmatic Evaluation Protocol for Speech Corpora (PREP-CORP). Macrostructure productivity and complexity included, respectively, the recall and sequential order of scenarios, episodes, events and characters. A total of four intervention sessions, lasting approximately 20 min, were delivered individually once a week. This brief intervention addressed explicit instruction about the narrative structure and the use of specific discourse markers to improve cohesion of story retellings. Intervention strategies included verbal scaffolding and modeling, conversational context for retelling the story and visual support with pictures printed from the cartoon. Results showed significant changes in WS students' retelling of the story, both at macro- and microstructure levels, when assessed following a 2-week interval. Outcomes were better in microstructure than in macrostructure, where sequential order (i.e., complexity) did not show significant improvement. These findings are consistent with previous research supporting the use of explicit oral narrative intervention with participants who are at risk of school failure due to communication impairments. Discussion focuses on how assessment and explicit instruction of narrative skills might contribute to effective intervention programs enhancing school engagement in WS students.

Evaluación de perfiles fonológicos en el síndrome x-frágil mediante índices de error

Los avances científicos que han tenido lugar en las últimas décadas han permitido identificar síndromes hasta entonces poco conocidos dentro del campo inespecífico que tradicionalmente se definía como “retraso o deficiencia mental”. El estudio de estos síndromes, entre los que se encuentra el síndrome X Frágil (SXF), ha permitido abandonar la concepción estática de la discapacidad intelectual, para pasar a una concepción dinámica que tiene en cuenta su desarrollo a lo largo del ciclo vital como resultado de la interacción entre sus capacidades de adaptación y los apoyos. Este trabajo, de acuerdo con dicho paradigma, se inscribe dentro del más amplio Proyecto Syndroling (Diez-Itza et al., 2014), de establecimiento comparado de perfiles lingüísticos en síndromes genéticos neuroevolutivos, y su objetivo es analizar los perfiles fonológicos de varones adultos con SXF. El estudio de los perfiles fonológicos se realizó a partir de muestras de habla espontánea de 6 varones adultos con SXF (Edad Media=38;6). Las muestras fueron recogidas y analizadas de acuerdo con la metodología RETAMHE y el Proyecto CHILDES (Diez-Itza, Snow y MacWhinney, 1999). Se analizaron la frecuencia y distribución relativa de los distintos tipos y clases de procesos (Estructura Silábica, Sustitución, Omisión y Asimilación), construyendo los perfiles fonológicos a partir de índices de error calculados en función de la frecuencia léxica (Martínez, 2010). Los resultados muestran un perfil fonológico específico del SXF caracterizado por una incidencia relativa mayor de procesos de Estructura de la Sílaba y menor de Sustitución y Omisión que en el desarrollo típico (DT) y en el Síndrome de Down (SD). El nivel fonológico en el SXF podría considerarse por tanto más cercano al buen nivel observado en el Síndrome de Williams (SW) que a las dificultades específicas del SD, lo que abre posibilidades a fundamentar en él la intervención en el discurso y la lectura.

Narrative competence in Spanish-speaking adults with Williams syndrome

BACKGROUND

Williams syndrome (WS) is a genetic disorder associated with intellectual disability and characterised by displaying an atypical neuropsychological profile, with peaks and valleys, where language skills seem better preserved than non-verbal intelligence.

METHOD

This study researches the narrative competence of nine Spanish-speaking adults with WS. Oral narratives were elicited from a silent film, and narrative coherence was analysed as a function of sequential order of the events narrated at three structure levels, while narrative cohesion was assessed through the frequency of use and type of discourse markers.

RESULTS

WS subjects were able to remember a significant proportion of the events from the film, but coherence of narratives, i.e., sequential order of events, was more impaired. Consistently with their linguistic abilities, cohesion of narratives was better preserved, as they used discourse markers to introduce a high proportion of events.

CONCLUSIONS

Construction of mental models of the narratives may be constrained in WS by non-verbal cognitive abilities, but narrative competence is also determined by textual pragmatic abilities to organize discourse, which should be addressed by specific intervention in narrative competence.

Biomarkers in Ocular Chronic Graft Versus Host Disease: Tear Cytokine- and Chemokine-Based Predictive Model

PURPOSE

To develop a tear molecule level-based predictive model based on a panel of tear cytokines and their correlation with clinical features in ocular chronic graft versus host disease (cGVHD).

METHODS

Twenty-two ocular cGVHD patients and 21 healthy subjects were evaluated in a controlled environmental research laboratory (CERLab). Clinical parameters were recorded, and tears were collected. Levels of 15 molecules (epidermal growth factor [EGF], IL receptor antagonist [IL-1Ra], IL-1β, IL-2, IL-6, IL-8/CXCL8, IL-10, IL-12p70, IL-17A, interferon inducible protein [IP]-10/CXCL10, IFN-γ, VEGF, TNF-α, eotaxin 1, and regulated on activation normal T cell expressed and secreted [RANTES]) were measured by multiplex-bead assay and correlated with clinical parameters. Logistic regression was used to develop a predictive model. Leave-one-out cross-validation was applied. Classification capacity was evaluated in a cohort of individuals with dry eye (DE) of other etiologies different from GVHD.

RESULTS

Epidermal growth factor and IP-10/CXCL10 levels were significantly decreased in ocular cGVHD, positively correlating with tear production and stability and negatively correlating with symptoms, hyperemia, and vital staining. Interleukin-1Ra, IL-8/CXCL8, and IL-10 were significantly increased in ocular cGVHD, and the first two correlated positively with symptoms, hyperemia, and ocular surface integrity while negatively correlating with tear production and stability. Predictive models were generated, and the best panel was based on IL-8/CXCL8 and IP-10/CXCL10 tear levels along with age and sex, with an area under the receiving operating curve of 0.9004, sensitivity of 86.36%, and specificity of 95.24%.

CONCLUSIONS

A predictive model based on tear levels of IL-8/CXCL8 and IP-10/CXCL10 resulted in optimal sensitivity and specificity. These results add further knowledge to the search for potential biomarkers in this devastating ocular inflammatory disease.

Persistent alterations in colonic afferent innervation in a rat model of postinfectious gut dysfunction: Role for changes in peripheral neurotrophic factors

BACKGROUND

Visceral hypersensitivity in the inflamed gut is related partly to the effects of peripheral neurotrophic factors (NTFs) on local afferent neurons. However, alterations in sensory afferents of distant areas remain unexplored. Using the Trichinella spiralis infection model, which causes a jejunitis, we investigated the remodeling of colonic afferents and the potential role of NTFs.

METHODS

Rats were infected with T. spiralis. Inflammatory-like changes, mucosal mast cells (MMCs) dynamics, and expression of nerve growth factor and glial cell line-derived NTFs (glial cell-derived neurotrophic factor, artemin, and neurturin) were determined in the colon up to day 30 postinfection. Functional responses of colonic afferents were determined assessing changes in the expression of sensory-related markers in thoracolumbar (TL)/lumbosacral (LS) dorsal root ganglias (DRGs) following intracolonic capsaicin.

KEY RESULTS

Trichinella spiralis induced an inflammatory-like response within the colon, partly resolved at day 30 postinfection, except for a persistent MMC infiltrate. While the jejunum of infected animals showed an up-regulation in the expression of NTFs, a transitory down-regulation was observed in the colon. Overall, T. spiralis effects on DRGs gene expression were restricted to a transient down-regulation of TPRV1. Stimulation with intracolonic capsaicin induced a down-regulation of TRPV1 levels in TL and LS DRGs, an effect enhanced in LS DRGs of infected animals, regardless the postinfection time considered.

CONCLUSIONS & INFERENCES

During intestinal inflammation, spread morphological and functional alterations, including remodeling of visceral afferents, are observed outside the primary region affected by the insult. Similar mechanisms might be operating in states of widespread alterations of visceral sensitivity.

Influence of vehicles on antioxidant efficacy in hair

Microspheres are the best vehicle to increase the antioxidant efficacy of gallic acid in hair.

Diagnosis and management of breakthrough cancer pain: Have all the questions been resolved? A Delphi-based consensus assessment (DOIRON)

OBJECTIVE

To ascertain the level of agreement and achieve a consensus among cancer pain specialists in Spain with regard to the optimal definition, diagnosis, and management of breakthrough cancer pain (BTcP).

DESIGN

Two-round Delphi methodology survey (February-May 2013) using seven-point Likert scales (ranging from 1 "strongly disagree" to 7 "strongly agree") was carried out. Mean scores >5 or <3 indicated, respectively, agreement or disagreement. Scores from 3 to 5 indicated no consensus.

RESULTS

A total of 126 experienced specialists were surveyed. Response rates were 68 % in round 1 and 90 % in round 2. Agreement (mean Likert score) was strongest for the proposed BTcP definition (6.6), the use of oral (6.1), and intranasal (6.0) transmucosal fentanyl, the need for early assessment after BTcP treatment initiation, and the need to improve staff knowledge of BTcP. Broad agreement was also reached regarding the need to systematically screen all cancer patients for BTcP (5.9). Most respondents (82 %) considered strong opioids to be appropriate treatment. In contrast, no consensus was reached regarding strong opioid treatment for baseline pain as a prerequisite for BTcP diagnosis.

CONCLUSIONS

Consensus was strong for most treatment, and diagnostic aspects were evaluated in the study. However, several important issues remain unresolved, particularly whether the diagnostic criteria must include strong opioids for background pain. Nurses' awareness and understanding of BTcP was considered insufficient, and more training is needed in this area. Overall, agreement among specialists was good, but more work is needed to better define the optimal diagnostic features and treatments for this condition.

Gene Expression-Based Predictive Models of Graft Versus Host Disease-Associated Dry Eye

PURPOSE

To develop a predictive model based on inflammatory gene mRNA expression in conjunctival cells of graft versus host disease (GvHD)-associated dry eye (DE) patients, as well as to find meaningful correlations between gene signals and clinical signs.

METHODS

Twenty GvHD-DE patients and 14 healthy controls were recruited. Patients discontinued medications for 1 week before examination. Dry eye-related symptoms and signs were recorded, and conjunctival epithelial cells were collected by impression cytology after spending 20 minutes under standard conditions within a Controlled Environmental Research Laboratory. Gene expression of inflammatory molecules was determined by polymerase chain reaction, and the results were correlated with clinical signs. Shrinkage discriminant analysis, support vector machine, and k-nearest neighbor classifier methods were used to develop predictive models that were validated considering accuracy, calibration, and discriminant capability.

RESULTS

Out of the 84 genes analyzed, 34 showed significant differences in expression. IL-6, IL-9, CCL24, CCL18, IL-10, IFN-γ, and CCL2 were highly increased (>6-fold); 26 genes were moderately upregulated (2- to 6-fold), whereas EGFR was downregulated (2.63 fold) in GvHD-DE samples. A panel based on EGFR, IL-6, IL-9, and NAMPT had an area under the receiver operating characteristic curve of 0.994, a sensitivity of 100%, and a specificity of 92.9%. EGFR expression correlated negatively with ocular surface damage markers, while IL-6, IL-9, and NAMPT correlated positively with these tests.

CONCLUSIONS

EGFR, IL-6, IL-9, and NAMPT have the greatest potential as diagnostic biomarkers, with excellent sensitivity, specificity, and clinical relevance to the ocular surface status of GvHD.

Functional Genomic Screen Identifies Klebsiella pneumoniae Factors Implicated in Blocking Nuclear Factor κB (NF-κB) Signaling

Klebsiella pneumoniae is an etiologic agent of community-acquired and nosocomial pneumonia. It has been shown that K. pneumoniae infections are characterized by reduced early inflammatory response. Recently our group has shown that K. pneumoniae dampens the activation of inflammatory responses by antagonizing the activation of the NF-κB canonical pathway. Our results revealed that K. pneumoniae capsule polysaccharide (CPS) was necessary but not sufficient to attenuate inflammation. To identify additional Klebsiella factors required to dampen inflammation, we standardized and applied a high-throughput gain-of-function screen to examine a Klebsiella transposon mutant library. We identified 114 mutants that triggered the activation of NF-κB. Two gene ontology categories accounted for half of the loci identified in the screening: metabolism and transport genes (32% of the mutants) and envelope-related genes (17%). Characterization of the mutants revealed that the lack of the enterobactin siderophore was linked to a reduced CPS expression, which in turn underlined the NF-κB activation induced by the mutant. The lipopolysaccharide (LPS) O-polysaccharide and the pullulanase (PulA) type 2 secretion system (T2SS) are required for full effectiveness of the immune evasion. Importantly, these factors do not play a redundant role. The fact that LPS O-polysaccharide and T2SS mutant-induced responses were dependent on TLR2-TLR4-MyD88 activation suggested that LPS O-polysaccharide and PulA perturbed Toll-like receptor (TLR)-dependent recognition of K. pneumoniae. Finally, we demonstrate that LPS O-polysaccharide and pulA mutants are attenuated in the pneumonia mouse model. We propose that LPS O-polysaccharide and PulA T2SS could be new targets for the design of new antimicrobials. Increasing TLR-governed defense responses might provide also selective alternatives for the management of K. pneumoniae pneumonia.

Antibiotic-induced dysbiosis alters host-bacterial interactions and leads to colonic sensory and motor changes in mice

Alterations in the composition of the commensal microbiota (dysbiosis) seem to be a pathogenic component of functional gastrointestinal disorders, mainly irritable bowel syndrome (IBS), and might participate in the secretomotor and sensory alterations observed in these patients.We determined if a state antibiotics-induced intestinal dysbiosis is able to modify colonic pain-related and motor responses and characterized the neuro-immune mechanisms implicated in mice. A 2-week antibiotics treatment induced a colonic dysbiosis (increments in Bacteroides spp, Clostridium coccoides and Lactobacillus spp and reduction in Bifidobacterium spp). Bacterial adherence was not affected. Dysbiosis was associated with increased levels of secretory-IgA, up-regulation of the antimicrobial lectin RegIIIγ, and toll-like receptors (TLR) 4 and 7 and down-regulation of the antimicrobial-peptide Resistin-Like Molecule-β and TLR5. Dysbiotic mice showed less goblet cells, without changes in the thickness of the mucus layer. Neither macroscopical nor microscopical signs of inflammation were observed. In dysbiotic mice, expression of the cannabinoid receptor 2 was up-regulated, while the cannabinoid 1 and the mu-opioid receptors were down-regulated. In antibiotic-treated mice, visceral pain-related responses elicited by intraperitoneal acetic acid or intracolonic capsaicin were significantly attenuated. Colonic contractility was enhanced during dysbiosis. Intestinal dysbiosis induce changes in the innate intestinal immune system and modulate the expression of pain-related sensory systems, an effect associated with a reduction in visceral pain-related responses. Commensal microbiota modulates gut neuro-immune sensory systems, leading to functional changes, at least as it relates to viscerosensitivity. Similar mechanisms might explain the beneficial effects of antibiotics or certain probiotics in the treatment of IBS.

Foliar potassium nitrate application improves the tolerance of Citrus macrophylla L. seedlings to drought conditions

Scarcity of water is a severe limitation in citrus tree productivity. There are few studies that consider how to manage nitrogen (N) nutrition in crops suffering water deficit. A pot experiment under controlled-environment chambers was conducted to explore if additional N supply via foliar application could improve the drought tolerance of Citrus macrophylla L. seedlings under dry conditions. Two-month-old seedlings were subjected to a completely random design with two water treatments (drought stress and 100% water/field capacity). Plants under drought stress (DS) received three different N supplies via foliar application (DS: 0, DS + NH4NO3: 2% NH4NO3, DS + KNO3: 2% KNO3). KNO3-spraying increased leaf and stem DW as compared with DS + NH4NO3 and DS treatments. Leaf water potential (Ψw) was decreased by drought stress in all the treatments. However, in plants from DS + NH4NO and DS + KNO3, this was due to a decrease in the leaf osmotic potential, whereas the decrease in those from the DS treatment was due to a decrease in the leaf turgor potential. These responses were correlated with the leaf proline and K concentrations. DS + KNO3-treated plants had a higher leaf proline and K concentration than DS-treated plants. In terms of leaf gas exchange parameters, it was observed that net assimilation of CO2 [Formula: see text] was decreased by drought stress, but this reduction was much lower in DS + KNO3-treated plants. Thus, when all results are taken into account, it can be concluded that a 2% foliar-KNO3 application can enhance the tolerance of citrus plants to water stress by increasing the osmotic adjustment process.

Erythrocytes and cell line-based assays to evaluate the cytoprotective activity of antioxidant components obtained from natural sources

Oxidative stress can damage cellular components including DNA, proteins or lipids, and may cause several skin diseases. To protect from this damage and addressing consumer's appeal to natural products, antioxidants obtained from algal and vegetal extracts are being proposed as antioxidants to be incorporated into formulations. Thus, the development of reliable, quick and economic in vitro methods to study the cytoactivity of these products is a meaningful requirement. A combination of erythrocyte and cell line-based assays was performed on two extracts from Sargassum muticum, one from Ulva lactuca, and one from Castanea sativa. Antioxidant properties were assessed in erythrocytes by the TBARS and AAPH assays, and cytotoxicity and antioxidant cytoprotection were assessed in HaCaT and 3T3 cells by the MTT assay. The extracts showed no antioxidant activity on the TBARS assay, whereas their antioxidant capacity in the AAPH assay was demonstrated. On the cytotoxicity assays, extracts showed low toxicity, with IC50 values higher than 200μg/mL. C. sativa extract showed the most favourable antioxidant properties on the antioxidant cytoprotection assays; while S. muticum and U. lactuca extracts showed a slight antioxidant activity. This battery of methods was useful to characterise the biological antioxidant properties of these natural extracts.

[Evaluation of diet and nutrient intake in children under three years old. ALSALMA pilot study]

OBJECTIVE

The present study evaluates energy and nutrient intake in Spanish children under three years of age, and compares the results with the current recommendations in order to identify possible inadequate nutrient intake.

PATIENTS AND METHODS

A cross-sectional pilot study. The mothers completed a diet diary for four non-consecutive days, recording the products and amounts consumed by their children. Nutrient intake was calculated, and the results were compared with the dietary reference intakes (DRI) for each age group.

RESULTS

A total of 188 children (93 boys and 95 girls) aged 0-6 (n=41), 7-12 (n=24), 13-24 (n=57), and 25-36 months (n=66) were included. Statistically significant differences in DRI were observed for most of the nutrients analyzed. Protein intake, in particular was 376% of DRI in children between 1-3 years of age. By age groups, 96% of the children aged 7-12 months, 88% of the children aged 13-24 months, and 97% of the children aged 25-36 months showed protein intakes more than two-fold DRI.

CONCLUSIONS

Nutrient intake differed from the DRI, particularly as regards proteins. A new study is required to determine whether the observed study deviations could be representative of the national population of this age group, as well as the possible effects on child health.

Stress and antibiotics alter luminal and wall-adhered microbiota and enhance the local expression of visceral sensory-related systems in mice

BACKGROUND

Stress leads to altered gastrointestinal neuro-immune responses. We characterized the interaction between stress and gut commensal microbiota and their role modulating colonic responses to stress, the induction of inflammation, the expression of sensory-related markers, and visceral sensitivity.

METHODS

C57BL/6N female mice were treated (7 days, PO) with non-absorbable-broad spectrum antibiotics (bacitracin/neomycin, 0.4 mg per mouse per day). Simultaneously, mice were subjected to a 1 h per day (7 days) session of psychological stress (water avoidance stress, WAS). Luminal and wall-adhered microbiota were characterized by fluorescent in situ hybridization. Cannabinoid receptors 1 and 2 (CB1/2), tryptophan hydroxylase 1 and 2 (TPH1/2), and inflammatory markers were quantified by reverse transcription-quantitative real-time PCR (RT-qPCR) and secretory-IgA (s-IgA) by ELISA. Visceral sensitivity was assessed after the intracolonic administration of capsaicin.

KEY RESULTS

Antibiotics did not affect the defecatory and endocrine responses to stress. However, antibiotics diminished by 2.5-folds total bacterial counts, induced a specific dysbiosis and favored bacterial wall adherence. Combining antibiotics and stress resulted in further reductions in bacterial counts and a dysbiosis, with enhanced bacterial wall adherence. Luminal s-IgA levels increased in dysbiotic mice. Nevertheless, no alterations consistent with the induction of colonic inflammation were observed. Dysbiosis upregulated CB2 expression and stress upregulated CB2 and TPH1 expression. Stress enhanced visceral pain-related responses, an effect prevented by antibiotic treatment.

CONCLUSIONS & INFERENCES

Manipulations of the commensal microbiota and the interaction host-microbiota are able to modulate the local expression of neuro-immune-endocrine systems within the colon, leading to a modulation of visceral sensitivity. These mechanisms might contribute to the pathogenic and protective roles of microbiota in gastrointestinal homeostasis.

Environment-related adaptive changes of gut commensal microbiota do not alter colonic toll-like receptors but modulate the local expression of sensory-related systems in rats

Pathogenic and protective roles have been attributed to gut commensal microbiota (GCM) in gastrointestinal inflammatory and functional disorders. We have shown that the adaptation to a new environment implies specific changes in the composition of GCM. Here we assessed if environment-related adaptive changes of GCM modulate the expression of colonic Toll-like receptors (TLRs) and sensory-related systems in rats. Adult male SD rats were maintained under different environmental conditions: barrier-breed-and-maintained, barrier-breed adapted to conventional conditions or conventional-breed-and-maintained. Fluorescent in situ hybridization and real-time quantitative PCR (qPCR) were used to characterize luminal ceco-colonic microbiota. Colonic expression of TLR2, TLR4, TLR5, and TLR7, cannabinoid receptors (CB1/CB2), μ-opioid receptor (MOR), transient receptor potential vanilloid (TRPV1, TRPV3, and TRPV4), protease-activated receptor 2 (PAR-2), and calcitonin gene-related peptide were quantified by RT-qPCR. CB1, CB2 and MOR expression, was evaluated also by immunohistochemistry. In rats, housing-related environmental conditions induce specific changes of GCM, without impact on the expression of TLR-dependent bacterial recognition systems. Expression of sensory-related markers (MOR, TRPV3, PAR-2, and CB2) decreased with the adaptation to a conventional environment, correlating with changes in Bacteroides spp., Lactobacillus spp., and Bifidobacterium spp. counts. This suggests an interaction between GCM and visceral sensory mechanisms, which might be part of the mechanisms underlying the beneficial effects of some bacterial groups on functional and inflammatory gastrointestinal disorders.

In vitro study of the cytotoxicity and antiproliferative effects of surfactants produced by Sphingobacterium detergens

The application of biosurfactants in the biomedical field is growing due to their antimicrobial activity, low cytotoxicity and ability to induce apoptosis in cancer cells. In the light of this therapeutic potential, as well as possible applications in cosmetics or as drug vehicles in pharmaceutical products, a new biosurfactant produced by Sphingobacterium detergens was investigated for its haemolytic activity and cytotoxic and antiproliferative effects in different cell lines. Fraction A showed 100% haemolysis in rabbit erythrocytes, but in Fraction B the rate was only 83%. When comparing cytotoxicity values (IC50) of the two fractions in model fibroblast and keratinocyte cell cultures, Fraction B was less cytotoxic, showing lower values than the reference compound SDS, indicating low skin irritability. Finally, in non-differentiated intestinal Caco-2 cultures, Fractions A and B reduced cell proliferation and induced apoptosis by 44% and 75%, respectively. According to these results, biosurfactants produced by S. detergens have potential application in cosmetic and pharmaceutical formulations.

Wolbachia, filariae and Leishmania coinfection in dogs from a Mediterranean area

OBJECTIVES

In an endemic area for leishmaniosis and filariasis, coinfection can occur and the immunomodulation triggered by Wolbachia infection might influence the clinical signs and progression of both diseases. The aims of this study were to determine the prevalence of Wolbachia in dogs infected with Dirofilaria immitis and other filarial nematodes, to evaluate the prevalence of coinfection of Leishmania infantum, filariae and Wolbachia and their association with clinical presentation.

METHODS

Polymerase chain reaction assays were performed to detect filarial species, Wolbachia species and Leishmania in 118 samples of dogs from southeastern Spain with leishmaniosis and/or filariasis.

RESULTS

Ninety-eight dogs were infected with Leishmania and 49 had filarial infection (29 were coinfected with both). Wolbachia DNA was detected in 30·6% of filariae-positive dogs (15/49). Dogs coinfected with Leishmania and filaria had more severe clinical signs. Wolbachia infection was significantly (P=0·026) more frequent in dogs that were not infected with Leishmania. There was no correlation between outcome and coinfection with these pathogens.

CLINICAL SIGNIFICANCE

This study highlights the increased sensitivity of polymerase chain reaction in the diagnosis of filariasis, confirms the presence of Wolbachia in dogs from the Mediterranean basin, shows the increased severity of clinical signs when Leishmania-filarial coinfection is present and suggests a protective role of Wolbachia in leishmaniosis.

NGF is involved in oral ovalbumin-induced altered colonic contractility in rats: evidence from the blockade of TrkA receptors with K252a

BACKGROUND

Nerve growth factor (NGF)-mucosal mast cell (MMC) interaction has been implicated in the remodeling of enteric circuitries and associated functional changes. We investigated the involvement of NGF and its receptor TrkA in the altered colonic contractile activity observed in the model of oral ovalbumin (OVA)-induced MMC hyperactivity in rats. We also studied the role of colonic MMCs as a source of NGF.

METHODS

Rats received oral OVA, alone or with the TrkA antagonist K252a. Colonic co-expression of NGF/TrkA and rat mast cell protease II (RMCPII) (double immunofluorescence), RMCPII content (ELISA) and expression of NGF, Brain-derived neurotrophic factor (BDNF) and TrkA/B (QT-PCR) were assessed. Colonic contractile activity was determined in vivo and in vitro.

KEY RESULTS

TrkA, but not NGF, was localized in colonic MMCs (RMCPII-positive). Oral ovalbumin exposure increased colonic RMCPII levels but did not change the percentage of TrkA-positive MMCs. Neither OVA nor K252a, alone or combined, altered NGF, BDNF or TrkA/B expression. Spontaneous colonic activity in vivo and in vitro was altered by OVA, an effect prevented by K252a. Electrical stimulation-induced contractile responses in vivo and carbachol responses in vitro were increased by OVA in a K252a-independent manner. In OVA-treated animals, inhibition of NO synthesis with l-NNA significantly enhanced spontaneous colonic activity in vitro, a response completely prevented by K252a.

CONCLUSIONS & INFERENCES

These results suggest that NGF-TrkA-dependent pathways are implicated in colonic contractile alterations observed during OVA exposure in rats. NGF-TrkA system might represent a potential target for treatment of gastrointestinal disorders characterized by colonic motor alterations.

[Assimilation processes in the late stages of phonological development]

This article reports a research on late phonological assimilation processes in child language in order to determine the possible stages in their evolution and the variations in relative frequency as a function of directionality (progressive vs. regressive), distance (contiguous vs. non-contiguous), and type of phonemes involved in assimilations (consonants vs. vowels). The corpus analyzed was collected from 240 children ranging in age between three and six years old. The speech samples were obtained in naturalistic settings of spontaneous conversation with the researchers, and were transcribed and analyzed with the tools provided by the CHILDES Project. Results describe a profile with three stages, reflecting the general dynamics of phonological development. Around the age of four, a general reorganization of the phonological system takes place, and the least frequent assimilation processes (progressive, contiguous and intervocalic) tend to disappear earlier. The most frequent assimilation processes (regressive, non-contiguous and inter-consonant) tend to persist as processing errors in the transition to adult speech. These findings show the functional complexity of late assimilation processes, as well as the need for taking it into account when planning clinical intervention.

Grape epicatechin conjugates prevent erythrocyte membrane protein oxidation

Epicatechin conjugates obtained from grape have shown antioxidant activity in various systems. However, how these conjugates exert their antioxidant benefits has not been widely studied. We assessed the activity of epicatechin and epicatechin conjugates on the erythrocyte membrane in the presence and absence of a peroxyl radical initiator, to increase our understanding of their mechanisms. Thus, we studied cell membrane fluidity by fluorescence anisotropy measurements, morphology of erythrocytes by scanning electron microscopy, and finally, red cell membrane proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Our data showed that incubation of red cells in the presence of epicatechin derivatives altered membrane fluidity and erythrocyte morphology but not the membrane protein pattern. The presence in the medium of the peroxyl radical initiator 2,2'-azobis(amidinopropane) dihydrochloride (AAPH) resulted in membrane disruptions at all levels analyzed, causing changes in membrane fluidity, cell morphology, and protein degradation. The presence of antioxidants avoided protein oxidation, indicating that the interaction of epicatechin conjugates with the lipid bilayer might reduce the accessibility of AAPH to membranes, which could explain in part the inhibitory ability of these compounds against hemolysis induced by peroxidative insult.

Genetic control of canine leishmaniasis: genome-wide association study and genomic selection analysis

BACKGROUND

The current disease model for leishmaniasis suggests that only a proportion of infected individuals develop clinical disease, while others are asymptomatically infected due to immune control of infection. The factors that determine whether individuals progress to clinical disease following Leishmania infection are unclear, although previous studies suggest a role for host genetics. Our hypothesis was that canine leishmaniasis is a complex disease with multiple loci responsible for the progression of the disease from Leishmania infection.

METHODOLOGY/PRINCIPAL FINDINGS

Genome-wide association and genomic selection approaches were applied to a population-based case-control dataset of 219 dogs from a single breed (Boxer) genotyped for ~170,000 SNPs. Firstly, we aimed to identify individual disease loci; secondly, we quantified the genetic component of the observed phenotypic variance; and thirdly, we tested whether genome-wide SNP data could accurately predict the disease.

CONCLUSIONS/SIGNIFICANCE

We estimated that a substantial proportion of the genome is affecting the trait and that its heritability could be as high as 60%. Using the genome-wide association approach, the strongest associations were on chromosomes 1, 4 and 20, although none of these were statistically significant at a genome-wide level and after correcting for genetic stratification and lifestyle. Amongst these associations, chromosome 4: 61.2-76.9 Mb maps to a locus that has previously been associated with host susceptibility to human and murine leishmaniasis, and genomic selection estimated markers in this region to have the greatest effect on the phenotype. We therefore propose these regions as candidates for replication studies. An important finding of this study was the significant predictive value from using the genomic information. We found that the phenotype could be predicted with an accuracy of ~0.29 in new samples and that the affection status was correctly predicted in 60% of dogs, significantly higher than expected by chance, and with satisfactory sensitivity-specificity values (AUC = 0.63).

pH-Sensitive surfactants from lysine: assessment of their cytotoxicity and environmental behavior

The toxicity and environmental behavior of new pH-sensitive surfactants from lysine are presented. Three different chemical structures are studied: surfactants with one amino acid and one alkyl chain, surfactants with two amino acids on the polar head and one alkyl chain, and gemini surfactants. The pH sensitivity of these compounds can be tuned by modifying their chemical structures. Cytotoxicity has been evaluated using erythrocytes and fibroblast cells. The toxic effects against these cells depend on the hydrophobicity of the molecules as well as their cationic charge density. The effect of hydrophobicity and cationic charge density on toxicity is different for each type of cells. For erythrocytes, the toxicity increases as hydrophobicity and charge density increases. Nevertheless, for fibroblasts cationic charge density affects cytotoxicity in the opposite way: the higher charge density, the lower the toxicity. The effect of the pH on hemolysis has been evaluated in detail. The aquatic toxicity was established using Daphnia magna . All surfactants yielded EC(50) values considerably higher than that reported for cationic surfactants based on quaternary ammonium groups. Finally, their biodegradability was evaluated using the CO(2) headspace test (ISO 14593). These lysine derivatives showed high levels of biodegradation under aerobic conditions and can be classified as "readily biodegradable compounds".

Persistent epithelial barrier alterations in a rat model of postinfectious gut dysfunction

BACKGROUND

Mucosal mast cells (MMCs), epithelial barrier function (EBF) and the enteric nervous system (ENS) are interactive factors in the pathophysiology of functional gastrointestinal disorders. We characterized postinfectious EBF alterations in the Trichinella spiralis infection model of MMC-dependent intestinal dysfunction in rats.

METHODS

Sprague-Dawley rats were infected with T. spiralis. 30 ± 2 days postinfection, jejunal EBF (electrophysiological parameters, fluorescein isothiocyanate-dextran fluxes and responses to secretagogues and MMC degranulators) was evaluated (Ussing chamber). In some experiments, participation of secretomotor neurons was examined by tetrodotoxin (TTX) pretreatment. Jejunal histology and MMC count and activity were also assessed.

KEY RESULTS

30 ± 2 days postinfection, when only a low grade inflammation was observed, increased MMC number and activity were associated with altered EBF. EBF alterations were characterized by increased mucosal permeability and ion secretion. In T. spiralis-infected animals, secretory responses to serotonin (5-HT) and immunoglobulin E (IgE)-dependent activation of MMCs were reduced. In contrast, responses to substance P (SP) and capsaicin were similar in infected and noninfected animals. Neuronal blockade with TTX altered secretory responses to SP and capsaicin only in infected rats.

CONCLUSIONS & INFERENCES

Trichinella spiralis infection in rats, at late stages, results in persistent postinfectious intestinal barrier dysfunctions and mucosal mastocytosis, with other signs suggestive of a low grade inflammation. The altered permeability and the TTX-independent hyporesponsiveness to 5-HT and IgE indicate epithelial alterations. Changes in responses to SP and capsaicin after neuronal blockade suggest an ENS remodeling during this phase. Similar long-lasting neuro-epithelial alterations might contribute to the pathophysiology of functional and postinfectious gastrointestinal disorders.

A selective sweep of >8 Mb on chromosome 26 in the Boxer genome

BACKGROUND

Modern dog breeds display traits that are either breed-specific or shared by a few breeds as a result of genetic bottlenecks during the breed creation process and artificial selection for breed standards. Selective sweeps in the genome result from strong selection and can be detected as a reduction or elimination of polymorphism in a given region of the genome.

RESULTS

Extended regions of homozygosity, indicative of selective sweeps, were identified in a genome-wide scan dataset of 25 Boxers from the United Kingdom genotyped at ~20,000 single-nucleotide polymorphisms (SNPs). These regions were further examined in a second dataset of Boxers collected from a different geographical location and genotyped using higher density SNP arrays (~170,000 SNPs). A selective sweep previously associated with canine brachycephaly was detected on chromosome 1. A novel selective sweep of over 8 Mb was observed on chromosome 26 in Boxer and for a shorter region in English and French bulldogs. It was absent in 171 samples from eight other dog breeds and 7 Iberian wolf samples. A region of extended increased heterozygosity on chromosome 9 overlapped with a previously reported copy number variant (CNV) which was polymorphic in multiple dog breeds.

CONCLUSION

A selective sweep of more than 8 Mb on chromosome 26 was identified in the Boxer genome. This sweep is likely caused by strong artificial selection for a trait of interest and could have inadvertently led to undesired health implications for this breed. Furthermore, we provide supporting evidence for two previously described regions: a selective sweep on chromosome 1 associated with canine brachycephaly and a CNV on chromosome 9 polymorphic in multiple dog breeds.

Pressure-induced cooperative spin transition in ironII 2D coordination polymers: room-temperature visible spectroscopic study

For the 2D coordination polymers [Fe(3-Fpy)(2)M(II)(CN)(4)] (M(II) = Ni, Pd, Pt), the pressure-induced spin crossover behavior has been investigated at 298 K by monitoring the distinct optical properties associated with each spin state. Cooperative first-order spin transition characterized by a piezohysteresis loop ca. 0.1 GPa wide was observed for the three derivatives. Application of the mean field regular solution theory has enabled estimation of the cooperative parameter, Γ(p), and the enthalpy, ΔH(HL)(p), associated with the spin transition for each derivative. These values, found in the intervals 6.8-7.9 and 18.6-20.8 kJ mol(-1), respectively, are consistent with those previously reported for thermally induced spin transition at constant pressure for the title compounds (Chem.-Eur. J.2009, 15, 10960). Relevance of the elastic energy, Δ(elast), as a corrective parameter accounting for the pressure dependence of the critical temperature of thermally induced spin transitions (Clausius-Clapeiron equation) is also demonstrated and discussed.

Canine leishmaniasis: the key points for qPCR result interpretation

Background

Diagnosis and follow up of CanL is difficult since the range of clinical signs is varied and seroprevalence is high in endemic areas. The aims of this study were: i) demonstrate the advantages of Leishmania qPCR to diagnose and control CanL and highlight its prognostic value and ii) propose guidelines for tissue selection and infection monitoring.

Findings

This study included 710 dogs living in an endemic area of leishmaniasis. Forty percent (285/710) exhibited clinical signs consistent with CanL. Infection was detected in 36.3% (258/710) of the dogs of which 4.5% (32/710) were detected by qPCR, 16.2% (115/710) detected by ELISA and 15.6% (111/710) tested positive for both tests. Only 17.9% (127/710) of the dogs were classified sick (affected) with CanL.

All symptomatic dogs with medium or high ELISA titers were qPCR-positive in blood samples. All dogs with inconclusive or low ELISA results with high or medium qPCR parasitemia values developed the disease. Seventy one percent of asymptomatic ELISA-positive dogs confirmed by qPCR (medium to high parasitemia) developed the disease.

Bone marrow or lymph node aspirate should be selected to ensure the absence of the parasite in asymptomatic dogs: 100-1,000 parasites/ml in bone marrow are detectable in blood, whereas lower parasite loads are usually negative. Almost 10% of negative samples in blood were positive in conjunctival swabs.

Conclusions

Because qPCR allows parasite quantification, it is an effective tool to confirm a diagnosis of CanL in (i) cases of inconclusive ELISA results, (ii) when the dog has not yet seroconverted, or (iii) for treatment monitoring.