The effect of ethanol evaporation on the properties of inkjet produced liposomes.

BACKGROUND: Inkjet method has been used to produce nano-sized liposomes with a uniform size distribution. However, following the production of liposomes by inkjet method, the solvent residue in the product could have a significant effect on the properties of the final liposomes. OBJECTIVE: This research paper aimed to find a suitable method to remove ethanol content and to study its effect on the properties of the final liposomal suspension. METHOD: Egg phosphatidylcholine and lidocaine were dissolved in ethanol; and inkjet method at 80 kHz was applied to produce uniform droplets, which were deposited in an aqueous solution to form liposomes. Dry nitrogen gas flow, air-drying, and rotary evaporator were tested to remove the ethanol content. Liposome properties such as size, polydispersity index (PDI), and charge were screened before and after ethanol evaporation. RESULTS: Only rotary evaporator (at constant speed and room temperature for 2 h) removed all of the ethanol content, with a final drug entrapment efficiency (EE) of 29.44 ± 6.77%. This was higher than a conventional method. Furthermore, removing ethanol led to liposome size reduction from approximately 200 nm to less than 100 nm in most samples. Additionally, this increased the liposomal net charge, which contributed to maintain the uniform and narrow size distribution of liposomes. CONCLUSION: Nano-sized liposomes were produced with a narrow PDI and higher EE compared to a conventional method by using an inkjet method. Moreover, rotary evaporator for 2 h reduced effectively the ethanol content, while maintaining the narrow size distribution. Graphical abstract.

Behavioral profile in RASopathies.

Here, we describe neurobehavioral features in patients with RASopathies (i.e., Noonan syndrome, LEOPARD syndrome, Costello syndrome, and cardiofaciocutaneous syndrome), developmental disorders caused by mutations in genes coding transducers participating in the RAS-MAPK signaling cascade. Parents of 70 individuals with a RASopathy were asked to fill out the following questionnaires: Child Behavior Checklist (CBCL), Social Communication Questionnaire version lifetime (SCQ-L), and Modified Checklist for Autism in toddlers (M-CHAT). Data analysis indicated high rates of internalizing (37%) and externalizing problems (31%) on CBCL. Scores over the cut-off were documented in 64% of patients with cardiofaciocutaneous syndrome, 44% with Costello syndrome, and 12% with Noonan syndrome on SCQ-L/M-CHAT. Our findings indicate that mutations promoting dysregulation of the RAS-MAPK cascade mark an increased psychopathological risk and highlight that autistic-like behavior could be underdiagnosed in patients with RASopathies.

Visual processing in Noonan syndrome: dorsal and ventral stream sensitivity.

Global spatial and motion processing abilities were assessed in 18 patients with Noonan syndrome (NS) and in 43 matched controls using form and motion coherence testing, respectively. We observed a discrepancy between the two groups since the study group had significantly lower performances than the control group for form coherence while there was no impairment on motion coherence. All the patients were also assessed on the Movement Assessment Battery for Children (M-ABC) to evaluate visuomotor skills. Thirteen of the 18 (72%) also had global poor performances on the M-ABC. The results show that children with NS have a specific impairment in the global processing of visuospatial information and are likely to have a specific ventral stream deficit as also suggested by the frequent visuomotor perceptual difficulties. Testing form and motion coherence thresholds may be a useful diagnostic tool for this group of patients, despite their normal cognitive abilities, since aspects of global form processing and visuomotor perceptual difficulties can be identified and potentially targeted for a specific rehabilitation program.

Long term memory profile of disorders associated with dysregulation of the RAS-MAPK signaling cascade.

In the present study we evaluated long term memory in twenty individuals with molecularly confirmed diagnosis of Noonan syndrome and LEOPARD syndrome, two disorders caused by mutations in genes coding transducers participating in the RAS-MAPK signaling cascade. The profile of explicit long term memory abilities was investigated using PROMEA, which includes a battery of tests specifically developed to assess memory and learning in verbal, visual and spatial domains. Ten individuals (50%) had impaired (≤5th percentile) or below average (≤15th percentile) performance on a delayed verbal free recall memory task, four (20%) on a delayed visual recognition memory task, and only one (5%) on a delayed spatial recognition memory task. Our data suggest that dysregulation of the RAS-MAPK cascade may be associated with a pattern of reduced verbal recall memory performance but relative sparing of visual and spatial recognition memory.

Early visual assessment in preterm infants with and without brain lesions: correlation with visual and neurodevelopmental outcome at 12 months.

BACKGROUND: Several studies have reported the development of various aspects of visual function in infancy and early childhood in both preterm and term-born infants, but only a few studies have focused on the predictive power of neonatal visual findings in infants with brain lesions. AIMS: To explore visual findings at term age, and at 3 and 12 months corrected age in preterm infants (gestational age <33 weeks) with and without brain lesions; to compare the assessment at term age and at 12 months; and to assess the relationship between visual findings and neurodevelopmental outcome at 12 months. STUDY DESIGN: Cranial ultrasound scans (US) were classified in normal, mild or major abnormalities. One-hundred and forty-five infants were assessed with age specific tests for visual function at term age, and at 3 and 12 months. Neurodevelopmental assessment (Griffiths' Scales) was performed at 12 months. RESULTS: A good correlation was found between early and late visual assessment and neurodevelopment outcome. Of the 121 infants with normal neonatal visual assessment, 119 were also normal at 12 months and 116 had normal developmental quotient. Of the 24 infants with abnormal neonatal visual assessment, 12 were also abnormal at 12 months. All the false positives had normalised by 3 months. Of the 35 infants with major US abnormalities, 20 had normal and 15 abnormal scores on the neonatal assessment. At 1 year 17 had normal and 18 abnormal scores. CONCLUSION: A normal visual assessment at term age is a good predictor of normal visual and neurodevelopmental outcome at 12 months. An abnormal visual examination in the neonatal period was a less reliable prognostic indicator, infant should be reassessed at 3 months.

Hypoventilation in REM sleep in a case of 17p11.2 deletion (Smith-Magenis syndrome).

We describe a 2-year-old baby affected by Smith-Magenis syndrome (SMS), due to 17p11.2 deletion, who presented repeated episodes of hemoglobin desaturation during REM sleep. The boy, aged 14 months, presented a phenotype characterized by psychomotor delay, right posterior plagiocephaly, telecanthus, strabismus, upslanting palpebral fissures, broad hypoplastic nasal bridge, short philtrum, deep ring shaped skin creases around the limbs, proximal syndactyly, bilateral hypoacusia. Polysomnographic (PSG) recording showed episodes of REM-related hypoventilation (hemoglobin desaturations without apneas or hypopneas). Sleep disorders are present in almost all the cases of SMS, but very few reports describe the sleep-related respiratory patterns. The finding of REM hypoventilation in SMS does not allow an unequivocal interpretation. It could reflect a subclinical restrictive respiratory impairment or, alternatively, an impairment of central respiratory control during REM sleep. In SMS children, respiratory abnormalities during sleep, and in particular during REM sleep, may cause sleep disruption, reduction of time spent in REM sleep, and daytime sleepiness. We therefore suggest that some sleep abnormalities described in SMS could be consequent to Sleep Disordered Breathing, and in particular to REM hypoventilation. Sleep studies in SMS should include the recording of respiratory parameters.

Cortical visual function in preterm infants in the first year.

OBJECTIVE: To assess visual function in low-risk preterm infants at 3, 5, and 12 months corrected age to determine whether the maturation of visual function in the first year is similar to that reported in term-born infants. STUDY DESIGN: Seventy-five low-risk infants (25.0-30.9 weeks gestation) underwent ophthalmological examinations and a battery of tests (fix and follow, visual fields, acuity, attention at distance, and fixation shift) designed to assess various aspects of visual function at 3, 5, and 12 months corrected age. RESULTS: The results were comparable with normative data from term-born infants in all tests but fixation shift, suggesting that maturation of most aspects of visual function is not significantly affected by preterm birth. In contrast, >25% of preterm infants failed the fixation shift test at 3 months, with a higher percentage of failing at 5 and 12 months. CONCLUSIONS: There is a specific profile of early visual behavior in low-risk preterm infants, with a high percentage of infants failing a test that specifically assesses visual attention and provides a measure of cortical processing.

Visual and visuoperceptual function in children with Panayiotopoulos syndrome.

PURPOSE: The aim of this study was to assess behavioral aspects of visual function and visuoperceptual abilities in patients with Panayiotopoulos syndrome (PS), and their possible associations with clinical and electroencephalography (EEG) findings in order to establish the possible effect of interictal paroxysmal activity on visual performance. METHODS: The cohort included 28 patients (14 male and 14 female) of ages ranging between 4 and 15 years. All patients underwent serial videopolygraphic studies and a detailed battery of tests assessing visual abilities, including assessment of acuity, stereopsis, visual fields, and visuoperceptual abilities; tests included the Movement Assessment Battery for Children, the Visuo Motor Integration tests, and evaluation of motion and form coherence threshold. RESULTS: On the assessment of visual function, only 4 of the 28 (15%) had abnormal crowding acuity and one had abnormal stereopsis. On the visuoperceptual assessment, one patient had abnormal results on the Visuo Motor Integration tests, and one on the Movement Assessment Battery for Children, whereas 4 (15%) had abnormal results for form coherence threshold and one for motion threshold. DISCUSSION: Our results suggest that, although most of our patients had focal or diffuse EEG abnormalities involving the occipital regions, abnormalities of visual and visuoperceptual function were relatively uncommon. Age at onset of seizure <5 years and EEG activation to eye closure and during sleep can be considered as factors that slightly increased the risk for developing visual abnormalities. Their presence, however, was not always associated with abnormal visual findings.

Cognitive profile of disorders associated with dysregulation of the RAS/MAPK signaling cascade.

Mutations in genes coding for transducers participating in the RAS/MAPK pathway have been identified as the molecular cause underlying a group of clinically related developmental disorders with cognitive deficits of variable severity. To determine the spectrum of cognitive defects associated with dysregulation of this signal cascade, we studied the profile of cognitive abilities in patients with mutations affecting the PTPN11, SOS1, HRAS, KRAS, BRAF, RAF1, and MEK1 genes and phenotype-genotype correlations. Our findings support the observation that heterogeneity in cognitive abilities can be at least partially ascribed to the individual affected genes and type of mutation involved. While mutations affecting transducers upstream of RAS were less frequently associated with mental retardation, mutations in downstream components of the pathway were generally associated with a more severe cognitive impairment. Among patients with a heterozygous PTPN11 mutation, the T468M substitution was associated with a mean IQ significantly higher compared to that of individuals carrying the N308D change. Our study provides insights on the range of cognitive abilities in patients with gene mutations causing dysregulation of RAS signaling suggesting that the presence and severity of cognitive involvement can be predicted in part by the gene involved.

Visual function at 35 and 40 weeks' postmenstrual age in low-risk preterm infants.

OBJECTIVES: The objectives of this study were to (1) assess visual function in low-risk preterm infants at 35 and 40 weeks' postmenstrual age, (2) compare preterm visual abilities at term-equivalent age with term-born infants, and (3) evaluate effects of preterm extrauterine life on early visual function. METHODS: Visual function was assessed by using a validated test battery at 35 and 40 weeks' postmenstrual age in 109 low-risk preterm infants who were born at <31 weeks' gestation. The preterm findings were compared with data from term-born infants collected by using the same test protocol. RESULTS: All preterm infants completed both assessments. The 35-week responses were generally less mature than those at 40 weeks. Preterm infants at both ages were significantly more mature than term-born infants for ocular movements and vertical and arc tracking and at 40 weeks for stripe discrimination. In contrast, tracking a colored stimulus, attention at distance, and stripe discrimination were more mature at term age (in both term-born and preterm infants) than at 35 weeks. CONCLUSIONS: Our findings provide data for visual function at 35 and 40 weeks' postmenstrual age in low-risk preterm infants. The results suggest that early extrauterine experience may accelerate the maturation of aspects of visual function related to ocular stability and tracking but does not seem to affect other aspects that may be more cortically mediated.

Neurological examination of preterm infants at term equivalent age.

BACKGROUND: We previously reported the neurological findings of the Dubowitz neonatal examination in a cohort of 157 low-risk preterms born between 25 and 33 weeks gestational age (GA) and examined at term equivalent age (TEA). Median and range of scores were wider than those found in term-born infants and preterms showed a different neurological behaviour in specific items. However, the cohort number was too small to draw any definitive conclusion about the distribution of findings. AIMS: We provide normative data from a low-risk cohort of 380 preterm infants; we also assess the findings and their relationship to motor outcome in preterms with major cranial ultrasound (US) abnormality. STUDY DESIGN: We assessed, at TEA, 380 low-risk preterms born <35 weeks gestation (range 25-34.9, median 29) with normal 2 year motor outcome and 85 preterm infants with major US abnormality. RESULTS: At TEA low-risk preterms had less flexor limb tone, poorer head control but better visual following than term-born infants. For 28/34 of the neurological items the range and median scores were similar across gestational ages. In infants with major US lesions the range and median scores differed from low-risk preterms in 20/34 items; 40% of infants developing a diplegia and 80% developing a tetraplegia had >7 items outside the 90th centile; all infants with >12 items outside the 90th centile developed a tetraplegia. CONCLUSIONS: We provide reference values for the neurological examination of low-risk preterms at TEA. In infants with major US abnormality the number of items outside the 90th centile was an indicator of outcome severity.

Early assessment of visual function in full term newborns.

BACKGROUND: The assessment of visual function is part of all the neonatal neurological examination but it is often limited to the evaluation of ocular movements and the ability to fix and follow a target. AIM OF THE STUDY: To develop a simple battery of test items assessing different aspects of visual function that could be used as early as 48 h after birth. STUDY DESIGN AND SUBJECTS: : The final battery, which has been used in 50 full term low risk neonates, includes 9 items assessing ocular motility, both spontaneous and with focus on a visual target, fixation and tracking (horizontal, vertical and in an arc), the ability to discriminate stripes of different spatial frequency, and attention at distance. RESULTS: The battery proved easy to perform and did not require long training. The testing did not require a specific setting and was easy to use even for infants in incubators. The equipment is small and cleanable. CONCLUSION: Our paper suggests that a simple battery, which can be performed in 5/10 min, can be easily applied and provides useful information on various aspects of early neonatal visual function.

Application of a neonatal assessment of visual function in a population of low risk full-term newborn.

BACKGROUND: We have previously developed and described a battery of 9 items suitable for assessing different clinical aspects of visual function in newborn infants. AIM OF THE STUDY: Application of the test battery to a cohort of low risk term-born infants at 48 and 72 h after birth 1) to define the normative distribution of results for each item and 2) to document any effect of postnatal age. STUDY DESIGN AND SUBJECTS: 124 term-born low risk infants were assessed at 48 h; fifty of them were re-assessed 24 h later at 72 h. RESULTS: The visual test battery was successfully completed in 110 of the 124 infants assessed at 48 h and in all the 50 infants assessed at 72 h after birth. For 3 of the 9 items (fixation on a black/white target of concentric circles, on a coloured (red/yellow) face and horizontal tracking), the findings were very similar at both ages. For the remaining 6 items the range of findings was wider. There was a statistical difference in the responses obtained at 48 and 72 h for vertical and arc tracking (p<0.05) and the ability to discriminate stripes and attention at distance (p<0.001). CONCLUSION: Our results provide information on the visual abilities in a low risk population of term-born infants and the distribution of frequency of their visual responses to our battery of visual tests. These findings may be used as reference data when using our visual test battery in both clinical and research settings.

The development of vision.

Disorders of visual function are common findings in children with neonatal brain lesions of antenatal and perinatal onset. In the last few years the development of age appropriate batteries for assessing visual function in the first years and the combined use of neuroimaging and neurophysiological techniques have allowed to achieve better understanding of the mechanisms underlying development of vision in low risk infants and in those with brain lesions. We will review the main models of visual development and the tests available to assess visual function in infancy, focusing on the recently described battery of tests for assessing early visual abilities in preterm and full term infants.

Visual development in infants with prenatal post-haemorrhagic ventricular dilatation.

OBJECTIVE: The aim of this study was to assess visual function in 13 infants with evidence of prenatal post haemorrhagic ventricular dilatation. DESIGN: Infants were assessed at 5, 12 and 24 months using a battery of tests specifically designed to assess various aspects of visual function in infancy. Visual findings were correlated with several variables, including extent of the lesion and presence of epilepsy. RESULTS AND CONCLUSIONS: Abnormalities of visual function were frequent (over 60%) in our cohort at age 2 years, ranging from isolated abnormal ocular movements to severe abnormalities of all the aspects of visual function assessed. The most severe and persistent abnormalities of visual function were found in infants with grade IV intraventricular haemorrhage and shunted hydrocephalus who also had epilepsy in the first year.

Thalamic atrophy in infants with PVL and cerebral visual impairment.

The aim of this retrospective study was to establish the presence and severity of cerebral visual impairment in preterm infants with PVL. We also wished to establish whether abnormalities of visual function are related to brain MRI findings and more specifically not only to the involvement of optic radiations and occipital cortex but also to changes in the thalami, that are often affected in infants with PVL. Twelve infants with cystic PVL were assessed at 1 year (+2) corrected age with a battery of tests specifically designed to assess various aspects of visual function in infancy, such as ocular movements, visual acuity, visual fields and fixation shift. All infants also had a brain MRI. Eleven of the 12 had involvement of the optic radiations: all had some abnormalities of visual function and visual impairment was more severe in infants with more extensive involvement of the optic radiations. The child with normal optic radiations had normal visual function. Six of the 12 infants also had obvious signs of atrophy of the thalami and all had severe and wide-ranging abnormalities of visual function in all testing domains. Two children had equivocal atrophy of the thalami, both had some abnormalities of visual function. Four children had normal thalami and had normal visual function or only minor abnormalities on one of the visual tests. Our results suggest that the atrophy of the thalami may play an additional role in the abnormal development of visual function in infants with PVL and abnormal optic radiations.

Epilepsy in shunted posthemorrhagic infantile hydrocephalus owing to pre- or perinatal intra- or periventricular hemorrhage.

Epilepsy is relatively common in infants with hydrocephalus. Its mechanism is controversial; in fact, studies on etiologically heterogeneous series are not able to clarify the mechanism generating epilepsy or to suggest effective prevention and treatment strategies. Our study is aimed at assessing the onset and evolution of epilepsy, as well as concurrent cognitive development of a homogeneous series of shunted posthemorrhagic hydrocephalus owing to pre- or perinatal intra- or periventricular hemorrhage. Forty patients were enrolled in the study. Twenty-six were patients with grade II-III intraventricular hemorrhage, 16 of whom had associated ischemic lesions. In the remaining 14 patients, a grade IV intra-ventricular hemorrhage was found. Epilepsy was observed in 27 patients. Aside from 10 cases with nonsyndromic forms of epilepsy, it was possible to define at least three different age-dependent epileptic syndromes: symptomatic neonatal location-related epilepsy with transient West's syndrome in infancy in 5 patients; West's syndrome in 8 patients; and continuous spike-waves during sleep in 4 patients. Epilepsy was significantly correlated with ischemic lesions only. Early thalamic injuries frequently evolved toward continuous spike-waves during sleep, indicating that patients with thalamic injury must be monitored to detect continuous spike-waves during sleep early. Cerebellar atrophy, in addition to epilepsy and other brain injuries, accounted for disorders of cognitive development.