Role of adventitial nitric oxide in vascular hyporeactivity induced by lipopolysaccharide in rat aorta

This study was designed to elucidate the role of the adventitia in NO-mediated vascular effects of lipopolysaccharide (LPS). After incubation of rat aorta with LPS, the adventitia generated 3.5 times more nitrite plus nitrate than a corresponding segment of media. Control media covered by adventitia from LPS-treated aortic rings exhibited a 4 fold elevated level of cyclic GMP. Medial layers from LPS-treated aortic rings (like LPS-treated adventitia-intact rings) exhibited a decrease in sensitivity to noradrenaline (NA) that was reversed by 1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one (1 microM) or N omega-nitro-L-arginine methylester (0.3 mM). However, in contrast to LPS-treated adventitia-intact rings, medial layers showed no reduction in maximal contraction to NA and virtually no relaxation to L-arginine. These data indicate that in blood vessels exposed to LPS, the adventitia is a more powerful source of NO than the media. The adventitia-derived NO can reach soluble guanylyl cyclase in the medial layer and contribute greatly to vascular hyporeactivity and L-arginine-induced relaxation observed in blood vessels exposed to LPS.

Vasoplegia in sepsis depends on the vascular system, vasopressor, and time-point: a comparative evaluation in vessels from rats subjected to the cecal ligation puncture model

We evaluated the effects of phenylephrine, norepinephrine, angiotensin II, and vasopressin in mesenteric, renal, carotid, and tail arteries, and in perfused mesenteric vascular bed from rats subjected to the cecal ligation and puncture (CLP) model of sepsis. Phenylephrine and angiotensin II were less efficacious in mesenteric arteries from the CLP 6 h and CLP 18 h groups than in preparations from non-septic animals, but no differences were found for norepinephrine and vasopressin between the preparations. In renal arteries, none of the vasoconstrictors had impaired activity in the CLP groups. Nonetheless, carotid arteries from the CLP 18 h group presented reduced reactivity to all vasoconstrictors tested, but only phenylephrine and norepinephrine had their effects reduced in carotid arteries from the CLP 6 h group. Despite the reduced responsiveness to phenylephrine, tail arteries from septic rats were hyperreactive to vasopressin and norepinephrine at 6 h and 18 h after the CLP surgery, respectively. The mesenteric vascular bed from CLP groups was hyporeactive to phenylephrine, norepinephrine, and angiotensin II, but not to vasopressin. The vascular contractility in sepsis varies from the well-described refractoriness, to unaltered or even hyperresponsiveness to vasoconstrictors, depending on the vessel, the vasoactive agent, and the time period evaluated.

Examining the Latent Structure and Correlates of Sensory Reactivity in Autism: A Multi-site Integrative Data Analysis by the Autism Sensory Research Consortium

Background Differences in responding to sensory stimuli, including sensory hyperreactivity (HYPER), hyporeactivity (HYPO), and sensory seeking (SEEK) have been observed in autistic individuals across sensory modalities, but few studies have examined the structure of these "supra-modal" traits in the autistic population. Methods Leveraging a combined sample of 3,868 autistic youth drawn from 12 distinct data sources (ages 3-18 years and representing the full range of cognitive ability), the current study used modern psychometric and meta-analytic techniques to interrogate the latent structure and correlates of caregiver-reported HYPER, HYPO, and SEEK within and across sensory modalities. Bifactor statistical indices were used to both evaluate the strength of a "general response pattern" factor for each supra-modal construct and determine the added value of "modality-specific response pattern" scores (e.g., Visual HYPER). Bayesian random-effects integrative data analysis models were used to examine the clinical and demographic correlates of all interpretable HYPER, HYPO and SEEK (sub)constructs. Results All modality-specific HYPER subconstructs could be reliably and validly measured, whereas certain modality-specific HYPO and SEEK subconstructs were psychometrically inadequate when measured using existing items. Bifactor analyses unambiguously supported the validity of a supra-modal HYPER construct (ω H  = .800), whereas a coherent supra-modal HYPO construct was not supported (ω H  = .611), and supra-modal SEEK models suggested a more limited version of the construct that excluded some sensory modalities (ω H  = .799; 4/7 modalities). Within each sensory construct, modality-specific subscales demonstrated substantial added value beyond the supra-modal score. Meta-analytic correlations varied by construct, although sensory features tended to correlate most strongly with other domains of core autism features and co-occurring psychiatric symptoms. Certain subconstructs within the HYPO and SEEK domains were also associated with lower adaptive behavior scores. Limitations: Conclusions may not be generalizable beyond the specific pool of items used in the current study, which was limited to parent-report of observable behaviors and excluded multisensory items that reflect many "real-world" sensory experiences. Conclusion Psychometric issues may limit the degree to which some measures of supra-modal HYPO/SEEK can be interpreted. Depending on the research question at hand, modality-specific response pattern scores may represent a valid alternative method of characterizing sensory reactivity in autism.

The psychometric properties of a self-report inventory of autistic symptoms in individuals with autism spectrum disorder

INTRODUCTION AND METHODS

This study examined 85 parental-reports with 85 self-reports of autistic symptoms with the 84-item Coolidge Autistic Symptom Survey (CASS). The CASS covers all of the diagnostic criteria for autism spectrum disorder (ASD) in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), as no studies to date have compared the self-reports of individuals with autism with parent- or significant-other-reports of those individuals using the complete DSM-5.

RESULTS

The CASS-Parental-Report and CASS-Self-Report exhibited excellent internal reliability (α = 0.97 and 0.96, respectively). There was support for the hypothesis that parental-reports and self-reports would be similar (r = 0.66, p < 0.001).

DISCUSSION

In conclusion, the CASS should be considered a promising tool for assessing autistic symptoms from both parent- and self-perspectives.

Sensory Issues and Their Impact Among Autistic Children: A Cross-Sectional Study in Northern Sri Lanka

BACKGROUND

Sensory processing issues are among the key diagnostic criteria for autism spectrum disorder (ASD). As altered sensory processing causes autistic children to react differently to sensory experiences and has a profound impact on their development, affecting their learning ability, social interaction, and ability to adapt to a new environment, there is a need to recognize and address these issues in children diagnosed with ASD during assessments and interventions. This study aimed to identify the patterns of sensory issues and their impact, and selected correlates among autistic children attending a center for neurodevelopmental disorders in northern Sri Lanka.

METHODS

This institution-based, descriptive, cross-sectional study was conducted at a center for neurodevelopmental disorders in Jaffna among 100 children diagnosed with ASD. The sociodemographic details of the child, and scores of the Childhood Autism Rating Scale second edition (CARS™ 2), Sensory Profile™ 2, and a locally developed Behavioral Checklist were extracted from the records available at the center. Data were analyzed using R statistical computing software (R Foundation for Statistical Computing, Vienna, Austria) using general linear models.

RESULTS

All the children in this study had at least one sensory issue, with 50% having visual processing issues. The severity of ASD increased as auditory processing issues increased. Behavioral issues, in general, increased significantly with increasing auditory and visual processing issues. Repetitive behaviors significantly increased with increasing auditory processing issues, while problems with self-regulation increased significantly with increasing visual and movement processing issues. Conduct-related issues were found to increase significantly with increasing movement and visual processing issues, and attentional response issues were found to increase significantly with increasing auditory, visual, and touch processing issues.

CONCLUSION

The high prevalence of sensory issues in autistic children and its impact on the severity of ASD and behavioral issues are reiterated in this study. These results emphasize the importance of including interventions targeting sensory issues with the routine therapy for ASD.

The roles of sensory hyperreactivity and hyporeactivity in understanding infant fearfulness and emerging autistic traits

BACKGROUND

Existing evidence indicates that atypical sensory reactivity is a core characteristic of autism, and has been linked to both anxiety (and its putative infant precursor of fearfulness) and repetitive behaviours. However, most work has used cross-sectional designs and not considered the differential roles of hyperreactivity and hyporeactivity to sensory inputs, and is thus limited in specificity.

METHODS

161 infants with and without an elevated likelihood of developing autism and attention-deficit hyperactivity disorder (ADHD) were followed from 10 to 36 months of age. Parents rated an infant precursor of later anxiety (fearfulness) using the Infant Behaviour Questionnaire at 10 and 14 months, and the Early Childhood Behavioural Questionnaire at 24 months, and sensory hyperreactivity and hyporeactivity at 10, 14 and 24 months using the Infant Toddler Sensory Profile. Domains of autistic traits (restrictive and repetitive behaviours; RRB, and social communication interaction, SCI) were assessed using the parent-rated Social Responsiveness Scale at 36 months. Cross-lagged models tested (a) paths between fearfulness and hyperreactivity at 10-24 months, and from fearfulness and hyperreactivity to later autism traits, (b) the specificity of hyperreactivity effects by including hyporeactivity as a correlated predictor.

RESULTS

Hyperreactivity at 14 months was positively associated with fearfulness at 24 months, and hyperreactivity at 24 months was positively associated with SCI and RRB at 36 months. When hyporeactivity was included in the model, paths between hyperreactivity and fearfulness remained, but paths between hyperreactivity and autistic traits became nonsignificant.

CONCLUSIONS

Our findings indicate that alterations in early sensory reactivity may increase the likelihood of showing fearfulness in infancy, and relate to later social interactions and repetitive behaviours, particularly in individuals with a family history of autism or ADHD.