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Biomedical subjects

A Zani

Publications and source records attributed to A Zani.

15 recordsLinked to original sources
PubMed2006

Pathogenesis of apparent life-threatening events in infants with esophageal atresia.

Many infants with a repaired esophageal atresia (EA) undergo fundoplication, aortopexy, or glossopexy because the mechanisms most responsible for airway obstruction and/or apparent life-threatening event (AO/ALTE) syndrome are considered to be gastroesophageal reflux (GER), tracheal compression (TC), or obstructive apnea, respectively. In the present study, we investigated whether these mechanisms are independent or interrelated. We developed a database of 120 consecutive patients with EA treated by the senior author between 1967-2002. We studied the clinical manifestations of patients with a cervical esophagostomy and/or blind lower esophageal stump, which ruled out TC and/or proximal esophageal GER as a mechanism for AO/ALTE. Of 25 neonates who underwent section/ligation of lower tracheo-esophageal fistula and/or feeding gastrostomy, 10 critically ill neonates died. Of 15 survivors, 9 infants had a feeding gastrostomy without an esophagostomy. Of these, 6 infants presented one or more episodes of AO, and 8 presented ALTE with or without AO. Subsequently, 5 of the 9 infants underwent an esophagostomy. Eventually, 11 infants had a feeding gastrostomy with an esophagostomy. Of the latter, 5 infants presented one or more episodes of AO, and 6 presented ALTE without AO. In conclusion, oral feeding, proximal esophageal GER, and TC are not essential for AO/ALTE syndrome to occur. They are probably factors which offer evidence of an underlying problem with control of upper airway patency.

Bradycardia↗
PubMed2006

Nutritional surveillance in Tuscany: eating habits at breakfast, mid-morning and afternoon snacks among 8-9 y-old children.

INTRODUCTION: The prevalence of overweight and obesity in children is rapidly increasing in many countries. For that it has been interesting to investigate the eating habits of 8-9 y-old Tuscany children by paying attention to their meals frequency per day and their food choices in total and in relation to children's Body Mass Index (BMI) classes. In addition we considered some environment factors that could affect the children eating behaviours, such as mother's BMI and their education level. METHODS: A statistical sample of 3076 (1583 males, 1493 females), 8-9 year-old school-children was collected; weight and height were measured using standardized personnel and instruments. BMI classes were calculated using Cole et al.'s cutoff for children and adolescents. In order to evaluate the consumption frequency of individual meals and various foods, a Food Frequency Questionnaire (FFQ) was used, which was completed by the children themselves at school. A self-administered questionnaire revealed the weight and height of parents and their educational levels. Three educational levels were established: high, medium and low. RESULTS: The results showed that 92.3% of children ate breakfast from 4-7 times a week, the vast majority at home, while only 3% declared consuming breakfast never or almost never The most preferred breakfast consisted of milk and biscuits for all children's BMI classes. 95.9% of children reported having midmorning snack at school; fruit juice and tea are the most frequently consumed liquid foods, and pizza, salami sandwiches and pre-packaged snacks are the most frequently consumed solid foods in all BMI classes. 93.6% ate afternoon snack for the most part at home, even if 12% of children reported consuming it elsewhere; fruit juice and tea with pizza, sandwiches and pre-packaged snacks are still the most highly consumed foods by all children's BMI classes. The consumption frequency of breakfast (P < 0.001), mid-morning (P < 0.05) and afternoon snack (P < 0.05) of 8-9 y-old Tuscany children decrease with increase the children's BMI classes. The same tendency may be noted for the consumption frequency of breakfast in relation to mother's BMI (P < 0.05) and their education level (P < 0.05). This data strengthens the thesis that some home environments can affect the children's eating behaviours. CONCLUSION: No substantial differences in food choices at the meals analyzed were determined among normal weight, overweight and obese children. Children of normal weight had a greater tendency to consume meals more regularly. Mother's BMI and their education level can have influence on children's eating behaviours.

Body Mass Index↗
PubMed2003

Unusual extended fibular origin of the human soleus muscle: possible morpho-physiologic significance based on comparative anatomy.

A bilateral anomalous extended origin of the soleus muscle was observed in a 73-year-old female cadaver. It arose from the head, neck, and proximal two-thirds of the medial crest of the fibula and ran through the posterior intermuscular septum of the leg, from the lateral border of the fibula. The soleus muscle formed the vault of a muscular tunnel, overcoming the deep flexor muscles of the leg that was about 15 cm in length and directed inferiorly and laterally. The extended fibular origin delimited a blind recess lateral to the muscular tunnel and parallel to the posterior surface of the fibula. This recess measured 6.5 cm in length and extended 3.5 cm above the inferior opening of the muscular tunnel; the superior portion of the flexor hallucis longus was housed within it between the portions of the extended origin from the medial crest of the fibula and posterior intermuscular septum. The neurovascular bundle of the posterior leg coursed in the muscular tunnel. The tibial origin and calcaneal insertion of the soleus muscle were normal. Phylogenetic studies of the muscles of the lower limbs in mammals indicate that the fibular origin of soleus is more constant than the tibial origin and, in primates, the fibular origin is the only one observed in most monkeys. The case reported might be considered a conspicuous enlargement of the fibular origin observed in primates. This large fibular origin of the soleus muscle may prove to be a difficulty during surgery when accessing the proximal two-thirds of the fibula for ligation of the peroneal artery.

Aged↗
PubMed2001

ERP indexes of functional differences in brain activation during proper and common names retrieval.

Functional neuroimaging and neuropsychological findings suggest that memory retrieval of common and proper names is subserved by different neuro-functional systems but little is known about the topographic localization of neural generators. In the present study brain electrical activity was recorded with a high density electrode montage in healthy young volunteers during lexical retrieval upon written definition. ERPs spatio-temporal mapping showed on one side a strong activation of left anterior temporal and left central-frontal areas for proper names, and on the other side a greater involvement of occipital areas for common names retrieval. The specific pattern of bio-electrical activity recorded during proper names retrieval might index the activation of neural circuits for recalling names of high contextual complexity, poor of sensory-motor associations and dependent on precise spatio-temporal coordinates.

Adult↗
PubMed1998

Electrophysiological evidence of a perceptual precedence of global vs. local visual information.

Aim of the present study was to investigate the mechanisms of attentional selection of hierarchically organized visual patterns (compound letter stimuli), while subjects were engaged in target selection at either the global or local level. Event-related brain potentials (ERPs) were recorded using a high density electrode montage. Reaction times (RTs) to target stimuli were also recorded. RT data indicated the interference effect of global incongruent information with the local one. ERP data were consistent with behavioral data. In fact, the early sensory N115 component recorded at the primary visual areas exhibited smaller responses to locally attended elements when the global configuration was incongruent rather than congruent, suggesting an interference effect of the global with the local level. Conversely, no interference effect was found for globally attended configurations. These results strongly support the view of a perceptual advantage of globally conveyed information, very likely mediated by low spatial frequency channels. At later processing levels, N1 and P3 components were faster and larger when attention was paid to the global configuration. The difference between target and nontarget responses, indexing the attentional target selection, yielded a broad occipital-temporal negativity focused onto the left hemisphere in the attend-local, and over the right hemisphere in the attend-global condition. The present findings indicate a hemispheric asymmetry in cerebral activation during local/global processing. In addition, they provide robust evidence of a sensory precedence of global information.

Adult↗
PubMed1997

Hemispheric asymmetries for spatial frequency discrimination in a selective attention task.

Hemispheric specialization for spatial frequency processing was investigated by measuring reaction times to sinusoidal gratings in 12 healthy subjects. Stimuli of 1.5, 3, and 6 c/deg were randomly presented at two peripheral locations in the left (LVF) and right (RVF) upper visual hemifields during a selective attention task. Subjects were instructed to pay covert attention and to respond to a frequency in a given hemifield ignoring all other stimuli. Results showed that RTs were significantly faster at LVF than RVF for low frequency gratings, and at RVF than LVF for high frequency gratings. Furthermore, RTs were faster to 6 than 1.5 c/deg at the RVF, while there was not a significant difference at the LVF. In our view, these findings in a task requiring fast and accurate spatial frequency discriminations may be interpreted in terms of a hemispheric asymmetry for spatial frequency processing.

Adolescent↗
PubMed1995

ERP signs of early selective attention effects to check size.

In ERP literature on visual selective attention evidence has been provided that selectively directing attention to a spatial frequency affects the visual processing of the attended frequency, and of unattended frequencies within the same channel bandwidth, starting at a relatively late level of post-stimulus processing, i.e., after about 150 msec. Nevertheless, little knowledge is available about the topographic distribution of these attention effects. This study investigated attentional selection of stimulus relative size at occipital and latero-occipital sites, as well as at fronto-lateral sites. ERPs from posterior scalp electrode sites showed that attention to check sizes enhanced the early sensory components, thus indicating that feature-based attention may result in a modulation of sensory processing. Comparisons of the ERPs to relevant and irrelevant patterns showed an enhanced latero-occipital P90 positivity as well as an occipital N115 negativity to relevant patterns, thus also suggesting possible differential mechanisms of early attentional selectivity at these locations. Later effects of attention consisted of a selection negativity to relevant patterns at posterior electrodes, and a selection positivity at latero-frontal sites. A larger late positivity to irrelevant patterns at anterior sites also suggested an active suppression of attentional response to irrelevant information. Moreover, right-and left-sided asymmetries were found to be respectively consistent for the P90 and N115 with left hemispheric specialization for high, and right hemispheric specialization for low spatial frequencies. A stronger left-sided attentional selectivity has also been found.

Adult↗
PubMed1994

ERP and RT signs of a rightward bias for spatial orienting in a split-brain patient.

Neuropsychological data have shown that the two cerebral hemispheres differ in the control of spatial attention. The present study investigated hemispheric asymmetries and visuomotor integration in a split-brain patient and three control subjects. Simple reaction times (RTs) and event-related potentials (ERPs) were recorded to lateralized stimuli presented at different eccentricities in the left and right visual hemifields. Both electrophysiological and behavioural data showed that, unlike controls, the split-brain patient showed a strong rightward attentional bias resulting in shorter RTs and larger P300 potentials to stimuli falling in the rightmost space. Furthermore, ERPs also showed that while the RH has a bilateral control of visual space, the LH spatial orienting capability is most restricted to the contralateral hemifield.

Adult↗
PubMed1989

Brain evoked responses reflect information processing changes with the menstrual cycle in young female athletes.

In sport activity, information processing plays a role crucial for sport performance. Neuropsychological and psychophysiological evidence based on behavioral and psychophysical tasks has been accumulated showing that the latter changes over the course of the menstrual cycle, but the available data are rather inconsistent. On the other hand, in sport literature, not much attention has been devoted to these topics by researchers who have mainly been asked to investigate changes in mood and well-being. Therefore, a study has been undertaken to investigate the relationships between the menstrual cycle and information processing in young female athletes, some of whom took oral contraceptives. The study was based on Auditory Evoked Responses that, unlike behavioral and psychophysical techniques, were revealed to be an exceptionally reliable tool for the study of neural activity during sensory information processing. The results showed the existence of clear fluctuations over the course of the menstrual cycle in time taken to handle information and in the amount of information processing that, with differences and similarities, could be observed both in spontaneously menstruating and on-pill athletes. In addition, neuroanatomical differences were evident in the response of different neural structures of the auditory pathways. In fact, the effects of the hormonal changes accompanying the menstrual cycle appear to be more effective and influential at higher central levels of the auditory pathway.

Adult↗
PubMed1986

Differences in hemispheric functional asymmetry between athletes and nonathletes: evidence from a Unilateral Tactile Matching Task.

To study the hemispheric specialization for spatial information processing in athletes and nonathletes a Unilateral Tactile Matching Task was administered. Athletes showed more marked hemispheric specialization than nonathletes. The right hemisphere of the former, in fact, indicated a more pronounced accuracy than those of the latter in perceiving rod orientations.

Adult↗