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Biomedical subjects

A Boldrini

Publications and source records attributed to A Boldrini.

At least 37 records · Page 2Linked to original sources

Adrenarche, pubertal development, age at menarche and final height of full-term, born small for gestational age (SGA) girls.

Children born small for gestational age (SGA) may present advanced bone maturation in childhood and reduced final height. The objectives of the study were to evaluate adrenarche, pubertal development, age at menarche and final height in full-term born-SGA girls. Twenty-four girls (12 born-SGA and 12 matched controls) were evaluated at 6-7.5 years of age for clinical signs of puberty and dehydroepiandrosterone sulfate (DHEAS) levels, as a marker of adrenarche. Thirty-eight girls (19 born-SGA and 19 matched controls) were evaluated at 17.5-18.5 years of age to assess final height, sexual maturation and age at menarche. SGA girls had a mean final height (160.1 cm vs 165.8 cm, p < 0.01) and mean weight (52.1 kg vs 56.5 kg, p < 0.05) significantly lower than controls. Controls had a mean final height significantly higher than their mean target height. Sexual maturation was at stage 5 of Tanner's staging in SGA girls and control subjects. SGA girls had a slightly anticipated puberty (9.9 vs 10.4 years for initial breast development) and a lower age at menarche (11.9 vs 12.3 years). At 6-7.5 years of age, SGA females and controls did not show any difference for clinical signs of puberty; however, DHEAS levels (0.75 + 0.18 microgram/ml vs 0.57 + 0.22 microgram/ml, p < 0.05) were significantly higher in SGA girls than in control subjects. We concluded that full-term born-SGA females have impaired final height and weight in adolescence but substantially normal sexual maturation and age at menarche. Increased DHEAS levels before puberty in born-SGA girls may predispose to increased bone maturation in childhood with a reduced final height. In our population a progressive increment in final stature is evident.

Adolescent↗

Correlation between visual function, neurodevelopmental outcome, and magnetic resonance imaging findings in infants with periventricular leucomalacia.

AIM: To evaluate the correlation between visual function and neurodevelopmental outcome in children with periventricular leucomalacia at 1 and 3 years. METHOD: Visual acuity, visual field, ocular motility, and optokinetic nystagmus were tested in 29 infants with periventricular leucomalacia by brain magnetic resonance imaging. All infants also had a structured neurological examination and a Griffiths developmental assessment. RESULTS: 21 of the infants showed at least one abnormality of visual function. The degree of visual impairment-that is, the number of visual tests showing abnormal results-correlated well with the results on developmental assessment at both ages. CONCLUSION: Multivariate analysis showed that visual impairment was the most important variable in determining the neurodevelopmental scores of these infants, more than their motor disability and the extent of their lesions on magnetic resonance imaging.

Child, Preschool↗

Electroencephalography in infants with periventricular leukomalacia: prognostic features at preterm and term age.

Cystic periventricular leukomalacia represents the most severe white-matter lesion in preterm infants and its occurrence accounts for most cases of neurologic impairment in these subjects. Electroencephalographic (EEG) findings and their prognostic value in relation to motor and cognitive outcome were investigated in a group of preterm infants affected by different degrees of cystic periventricular leukomalacia. EEG recordings were carried out in the early postnatal period (first 2 weeks of life) on 24 infants and at term age on 29. In the early postnatal period, background EEG abnormalities ("dysmaturity") were significantly more apparent in affected infants than in a control group, and, among infants with cystic periventricular leukomalacia, this parameter related to the occurrence of cerebral palsy; moreover, at the same age, the incidence of abnormal EEG transients seemed to show a correlation with cognitive outcome. At term age, these latter abnormalities were significantly more apparent in neonates with cystic periventricular leukomalacia than in control subjects, but they did not show any prognostic value. In conclusion, these data indicate that, during the early postnatal period, the EEG is a useful diagnostic and prognostic tool for preterm infants with white-matter lesions, whereas at term age, the role of EEG tracings appears secondary.

Brain Damage, Chronic↗

Symptomatic hypercalcemia in the first months of life: calcium-regulating hormones and treatment.

Neonatal hypercalcemia is a rare condition often of unclear pathogenesis. If unrecognized and untreated it may result in central nervous system and renal damage. We studied three infants with symptomatic neonatal hypercalcemia pointing out pathogenetic and therapeutic aspects. One infant was found to have transient hyperparathyroidism with high intact parathyroid hormone (iPTH) levels. One infant had an incomplete form of Williams syndrome with hypercalcemia and an elfin facies. The pathogenesis is unclear in this case. A reduced secretion of calcitonin or an hypersensitivity to vitamin D might be the underlying defect. The third case was found to have subcutaneous fat necrosis and hypercalcemia associated with high 1,25(OH)2D levels and suppressed iPTH levels. These findings suggest an unregulated extrarenal 1,25(OH)2D production. These infants were treated with hydratation, furosemide, corticosteroids and low calcium diet. Symptomatic neonatal hypercalcemia should be treated promptly. However blood has to be taken before starting treatment to study calcium-regulating hormones and clarify pathogenesis.

Adrenal Cortex Hormones↗

Constantly discontinuous EEG patterns in full-term neonates with hypoxic-ischaemic encephalopathy.

OBJECTIVES: Selected EEG features were evaluated in 21 constantly discontinuous tracings recorded on the same number of full-term neonates with hypoxic-ischaemic encephalopathy. METHODS: The tracings were examined without using interval amplitude as the basis for distinguishing between burst-suppression and nonburst-suppression patterns. RESULTS: The results were related to outcomes and other clinical parameters (severity of hypoxic-ischaemic encephalopathy, pO2 levels and drug intake). CONCLUSIONS: Features defining the grade of EEG discontinuity (i.e. maximum interval duration, minimum burst duration and interval amplitude) significantly related to outcome and, in most cases, to the grade of hypoxic-ischaemic encephalopathy. Other features (amplitude of slow waves within the burst and incidence of abnormal EEG transients) related to PO2 levels. The consumption of anticonvulsant drugs increased EEG discontinuity, but this effect did not seem dose-related. Finally, the persistence of a constantly discontinuous EEG pattern after the first week of life is a sign of unfavourable prognosis. In full-term neonates with hypoxic-ischaemic encephalopathy quantitative analysis of all constantly discontinuous EEGs seems more useful than only describing burst-suppression patterns on the basis of interval amplitude.

Brain↗

Serum iodothyronines in the human fetus and the newborn: evidence for an important role of placenta in fetal thyroid hormone homeostasis.

UNLABELLED: The pattern of circulating iodothyronines in the fetus differs from that in the adult, being characterized by low levels of serum T3. In this study, concentrations of various iodothyronines were measured in sera from neonates of various postconceptional age (PA). Results obtained in cord sera at birth (PA, 24-40 weeks), reflecting the fetal pattern, were compared with those found during extrauterine life in newborns of 5 days or more of postnatal life (PA, 27-46 weeks). The main findings are: Starting at 30 weeks of PA, serum levels increase linearly during extrauterine life; and at 40 weeks, they are more than 200% of those measured in cord sera from newborns of equivalent PA. Serum reverse T3 (rT3) levels during fetal life are higher than those measured during extrauterine life; but they significantly decrease, starting at 30 weeks of PA. Serum T3 sulfate (T3S) does not significantly differ between the two groups, showing the highest values at 28-30 weeks of PA, and significantly decreasing at 30-40 weeks. T3S levels are directly correlated with rT3, both in fetal and extrauterine life, whereas a significant negative correlation between T3S and T3 is found only during extrauterine life. IN CONCLUSION: 1) changes in serum concentrations of iodothyronines in umbilical cord and during postnatal life indicate that maturation of extrathyroidal type I-iodothyronine monodeiodinase (MD) accelerates, starting at 30 weeks of PA; 2) high levels of type III-MD activity in fetal tissues prevent the rise of serum T3, whereas they maintain high levels of rT3 during intrauterine life; 3) an important mechanism leading to the transition from the fetal to the postnatal thyroid hormone balance is a sudden decrease in type III-MD activity; iv) because placenta contains a high amount of type III-MD, it is conceivable that placenta contributes to maintain low T3 and high rT3 serum concentrations during fetal life and that its removal at birth is responsible for most changes in iodothyronine metabolism occurring afterwards.

Female↗

Kinematic and qualitative analysis of lower-extremity movements in preterm infants with brain lesions.

BACKGROUND AND PURPOSE: The purposes of this study were to evaluate the effects of preterm birth, severe brain lesions, and postterm age on kicking movements of young infants and to compare the prognostic value of kinematic analysis of kicking with a qualitative assessment of infants' spontaneous movements. SUBJECTS: The subjects were 12 full-term infants without brain injury, 12 low-risk preterm infants without brain injury, and 11 preterm infants with severe brain lesions (periventricular leukomalacia). METHODS: Videotape recordings of each infant's motor behavior in a supine position were made at 1 and 3 months postterm age. Kicking frequency, temporal organization of the kick cycle, coordination among different joints, and interlimb coordination were measured. A qualitative assessment for lower-extremity movements and a Gestalt judgment of general movement quality according to Prechtl's method were made from the same videotape recordings. RESULTS: Kinematic analysis showed only mild differences among the 3 groups of infants. Qualitative assessment of the lower-extremity movements, however, showed that preterm infants with brain lesions, and particularly those who later were found to have cerebral palsy, consistently had fewer segmental movements of the foot and abnormal general movements at both ages. CONCLUSION AND DISCUSSION: The data suggest that the mechanisms responsible for kicking movements in newborns and young infants do not appear to be influenced by the extrauterine environment or by brain lesions, at least at the ages studied. Qualitative assessment of lower-extremity and general movements seems to be more appropriate for clinical purposes.

Biomechanical Phenomena↗

Electroclinical correlation in neonatal seizures.

A dissociation between clinical and electroencephalographic phenomena is often observable in neonatal seizures. This finding raises important questions, including those related to the management of these patients. Another characteristic of neonatal convulsions is represented by their increased tendency towards status epilepticus. In order to examine the electroclinical correlation and its possible relationship to the occurrence of status epilepticus, recorded video-electroencephalograms of 17 newborns were submitted to detailed analysis. Time of onset, duration and other characteristics of all clinical and electrical events were noted. Five degrees of correlation were observed, from constant concurrence to complete dissociation. Examining the role of different parameters, it was observed that the incidence of electric discharges related significantly to the occurrence of electroclinical dissociation.

Anticonvulsants↗

Visual outcome at 5 years of newborn infants at risk of cerebral visual impairment.

Visual development at 5 years of age was tested in a group of 39 children who had shown severe neonatal encephalopathy or perinatal brain lesions, documented by medical history, cranial ultrasound, or MRI. In all children, grating acuity was tested during the first 2 years of life. The assessment protocol at 5 years included various visual functions (grating and resolution acuity, visual field size, depth perception, optokinetic nystagmus, and ocular motility), and neurological and cognitive development. The majority of the children showed visual disorders of different type and degree, which were not due to ophthalmological abnormalities. Visual defects correlated well with the results of early visual assessment and of neuroimaging. Visual outcome could be predicted by grating acuity at 1 to 2 years in 27 of the 39 children, by neonatal cranial ultrasound in 26 of the 32 cases examined by this technique, and by later MRI in 23 out of 27. Moreover, a significant correlation was found between visual, motor, and cognitive impairment.

Brain↗

Cerebral visual impairment in preterm infants with periventricular leukomalacia.

Neonatal brain lesions are the main cause of cerebral visual impairment in infancy, i.e., of a visual deficit caused by damage to posterior visual pathways. Visual outcome of preterm infants with periventricular leukomalacia (PVL) was investigated in 14 subjects affected by severe cystic PVL, another 34 with moderate PVL (prolonged periventricular echodensities), and 18 control preterm infants. All cases with significant ocular abnormalities (such as retinopathy of prematurity state III or upwards, optic nerve atrophy, or major refraction problems) were excluded. Visual acuity, visual field, eye alignment, fixation and following, optokinetic nystagmus, and visual threat were tested at 1 year of corrected age. A high incidence of cerebral visual impairment, consisting mainly of low visual acuity, severe oculomotor disorders, and reduced visual field, was found in infants with severe PVL. Visual defects were less frequent and less severe in the moderate PVL group, and very rare in the control group. The results of neuroimaging, and especially of magnetic resonance imaging, correlated with the visual outcome and indicate lesions at the level of optic radiations as the main anatomic substrate of the visual impairment. All infants with PVL need a visual follow-up, from the first months of life, the results of which are important both for visual and motor rehabilitation of these cases and for their daily care.

Female↗

Final height in girls with slowly progressive untreated central precocious puberty.

A group of six girls with slowly progressive idiopathic precocious puberty (IPP) and a good initial height prognosis was followed without treatment. At first observation the girls had a bone age advance over chronological age of no more than 18 months, a delta height age (delta HA): delta bone age (delta BA) ratio higher than 0.9 and height prognosis was unimpaired after 6 months. During the first two years of follow-up the girls maintained an acceptable height potential. The delta HA:delta BA ratio remained constant at greater than 0.9. Predicted height showed a slight increase or decrease (+/- 4 cm). The girls were reevaluated after the age of 14 years and followed-up until they reached their final height (FH). The mean FH (155.4 +/- 2.8 cm) was below the mean target height (159.3 +/- 4.2 cm) by 3.9 cm (range -2.1 to -6.7 cm); this difference was not statistically significant. The FH was more than 5 cm below the target height in only one case; this girl had the most precocious onset of puberty, at 6 years of age. In three cases FH was between the 3rd and 10th centiles. These three girls had a target height below 158 cm (< 25th centile). Girls with slowly progressive IPP and a good initial height prognosis preserved height potential with an acceptable final height without therapy.

Age Determination by Skeleton↗

Rhythmical leg movements in low-risk and brain-damaged preterm infants.

The characteristics of rhythmical kicking movements of preterm infants with documented brain damage (BD), who later showed a severe motor impairment, are described and compared with those of low-risk (LR) preterm infants. Spontaneous movements were videotaped for 60 min in the incubator or in a warmer. A first group of 6 BD and 6 LR infants was observed at 31-35 weeks of postmenstrual age (PMA) and a second group (6 BD, 6 LR) at 37-39 weeks. Bouts of rhythmical kicks, defined as leg movements repeated in the same form at least three times at regular short intervals, were analysed during periods of activity. The results indicated non-significant differences between BD and LR infants at 31-35 weeks of PMA. In contrast, some differences were observed at 37-39 weeks. These differences were not due to leg movement frequency, but to inter-leg coordination and to temporal organisation of the kicking cycles. LR infants exhibited more alternate-leg movements and fewer semi-both-leg movements (simultaneous flexion and non-simultaneous extension) than BD infants. In LR cases the duration of the pause between flexion and extension was shorter, whereas flexion and extension periods were similar for all infants. Although there were significant differences, quantitative analysis of kicking characteristics was not clinically useful because of the large overlap in findings between the two groups. On the other hand Gestalt evaluation of general movements of the same videorecordings showed a closer correlation with the presence of brain lesions and with neurological outcome.

Brain Diseases↗

A clinician looks at androgen resistance.

Androgen resistance in genetic males occurs when gonadotropins and testosterone are normal, but the physiological androgen response in androgen target organs is absent or decreased. In androgen-dependent target tissues two main defects may be found: 1) defective testosterone metabolism (5 alpha-reductase type 2 deficiency) and 2) anomalies in androgen receptors (androgen insensitivity syndrome (AIS)). The clinical manifestations of these defects vary from subjects with female external genitalia to subjects with mild forms of impaired masculinization. In particular, in the complete form of AIS (CAIS) the phenotype is feminine, and in the partial form (PAIS) the external genitalia are ambiguous with an extremely variable phenotype. The diagnosis requires clinical, hormonal, genetic, and molecular investigation for appropriate gender assignation and treatment. In AIS, cloning of androgen receptor cDNA using the polymerase chain reaction, denaturing gradient gel electrophoresis, and nucleotide sequencing have enabled a variety of molecular defects in the androgen receptor to be identified. The complexity of phenotypic presentation of AIS probably reflects the heterogeneity of androgen receptor gene mutations, but to date a relationship between genotype/phenotype has been difficult to establish, with the same point mutation reported to be associated with different phenotypic expressions. Other factors must therefore also contribute to the clinical presentation of AIS, although none have yet been identified. Establishing the functional consequences of androgen receptor mutations in vitro systems and correlating them with clinical presentation may ultimately provide an explanation for the variable clinical presentation of AIS and perhaps enable prediction of the response to androgen therapy in infants with PAIS.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗

Prognostic value of abnormal EEG transients in preterm and full-term neonates.

The prognostic value of abnormal EEG transients was investigated in 362 subjects submitted to EEG recording during the neonatal age and followed-up at least until the 12th month of corrected age. The incidence of negative and positive spikes and sharp waves, of rhythmic sharp theta and delta activities and of alpha discharges were evaluated by means of a quantitative score. These abnormal EEG transients appeared to be generally rare and even absent in a large number of subjects. In infants with normal outcome their incidence tends to increase from low postmenstrual ages towards term period. Full-term newborns with abnormal neurological outcome presented a significantly higher incidence of these transients. Preterm infants with unfavourable evolution showed a higher incidence only when submitted to EEG recording at around term age. However, no difference between subjects with normal and abnormal outcome was detected in preterm infants when evaluated at low postmenstrual ages. The hypothesis that at low postmenstrual ages brain damage might, on the one hand, give rise to abnormal transients and, on the other, alter the "capability' of manifesting them (together with other EEG maturational aspects), might explain these results.

Brain↗

Background EEG activity in preterm infants: correlation of outcome with selected maturational features.

The aim of this study is to identify normal EEG patterns of preterm infants, characteristic of early postmenstrual ages (PMAs). Quantitative features of EEG background activity have been examined in records from 83 preterm infants within the first 2 weeks of life at a PMA of 27-34 weeks. These subjects presented different cranial ultrasound findings and different outcomes. EEG quantitative data have been compared to the subsequent neurological evolution. We supposed that the features of EEG background activity which were associated with a favourable outcome should be considered as indexes of "normality" of the tracing for that specific PMA. At 27-30 weeks of PMA a high incidence of "temporal sawtooth," a particular rhythmic theta activity detectable in temporal regions, relates to a favourable evolution, therefore it can be assumed that this activity is a normal feature of EEG tracings at this age. On the contrary, a significant correlation between a high incidence of "temporal sawtooth" and an abnormal outcome is observable at 33-34 weeks and leads us to deduce that this pattern should disappear at this time. After 31 weeks other parameters (such as the incidence of 8-20 Hz activities, the length of the intervals and burst duration) show a significant correlation with the outcome.

Brain↗

Differences and variations in the patterns of early independent walking.

The early development of walking was investigated in 25 normal fullterm and in 25 low-risk preterm infants. All subjects were videorecorded within 3-4 weeks of the beginning of independent walking and again 4 months later. Analysis of the videos was carried out according to a predetermined list of items, with a semiquantitative score for each. The results indicate wide interindividual differences in normal infants in the form of independent walking. Several items seemed to be associated in different ways in different individuals. Age of onset, as long as the corrected age was considered, did not differ between preterm and fullterm infants, neither did their walking patterns. Gait asymmetries were often observed in both groups and they were related with asymmetries observable in prewalking locomotor behaviour. Toe-strike often occurred at the beginning of walking, but not after 4 months; in preterm infants the toe strike pattern correlated significantly with certain motor characteristics observed during the first weeks of life.

Aging↗

Neuroimaging and functional outcome of neonatal leukomalacia.

Leukomalacia is a major cause of neurological impairment in the high-risk newborn. It can be identified during the early postnatal period by means of ultrasound (US) imaging of the brain, through the anterior fontanel. Magnetic resonance imaging (MRI) permits an optimal differentiation of brain tissue and of its abnormalities, without resorting to ionizing radiation or intravenous contrast. It is particularly appropriate for following the evolution of leukomalacia, after fontanel closure. Ninety-five fullterm and preterm infants with cystic and non-cystic leukomalacia, documented by US, were clinically followed-up until at least 12 months of corrected age. Thirty-two had a severe neurological outcome (mainly cerebral palsy, sometimes associated with mental retardation and/or cerebral visual impairment). The prognosis was worse in cystic leukomalacia than in prolonged flare. Electroencephalogram (EEG) carried out in the first 2 weeks of life provided valuable indexes of further outcome, especially for US findings of more uncertain prognosis. MRI was carried out at around 12 months of corrected age, by means of an apparatus operating at 0.5 Tesla. The main categories of abnormalities observed were the following: cystic lesions, enlarged ventricles with irregular outlines, delayed myelination, high intensity areas in the long TR (repetition time) images within the white matter, cortical atrophy. MRI findings correlated well with the results of US imaging and often with motor, cognitive and visual impairments. Nevertheless, clinical features cannot be predicted by neuroimaging alone and a comprehensive approach, including longitudinal functional and electrophysiological testing, is highly recommended.

Cognition↗