大鼠神经系统发育过程中神经元特异性烯醇酶的出现和意义

用自行提纯的人脑和牛脑神经元特异性烯醇酶(NSE)分别免疫家兔,制备兔抗人和抗牛NSE血清(抗NSEh和抗NSEb)。以PAP免疫组织化学染色,系统观察3O只发育出SD大鼠的脑、脊髓与脊神经节。发现NSE最先出现于胚胎15d的脊神经节神经元,随后相继出现于三叉神经节、脊髓、嗅皮质、海马、扣带回和外侧皮质神经元。表明NSE先后出现于周围神经和中枢神经系统,由脊髓向大脑、原始皮质及新皮质发展的顺序,与神经系统发育过程中的头向发展规律相一致。     

Predictive value of neonatal MRI as compared to ultrasound in premature infants with mild periventricular white matter changes

A follow-up study was performed in 42 premature infants in whom serial neonatal ultrasound and a single neonatal MRI of the brain was normal, or showed mild periventricular white matter changes. The aim of the study was to evaluate the clinical significance of periventricular signal intensity changes on MRI and to compare the predictive value of neonatal MRI with that of ultrasound. The infants underwent repeated standardised motor assessments and developmental tests. MRI was repeated at the corrected age of 12 months. Pronounced periventricular signal intensity changes on neonatal MRI and periventricular echodensities (flaring) on ultrasound were associated with a high incidence of transient motor problems during infancy. The degree of echogenicity carried the highest predictive value, as compared to duration of flaring on ultrasound and degree of periventricular signal intensity change on MRI. It is concluded that signal intensity changes on neonatal MRI represent the same ischaemic change of the periventricular white matter as flaring on ultrasound and that routine neonatal MRI screening is not warranted in premature infants without clinical evidence of neurological problems and with normal or mildly abnormal ultrasound scans. Recording of the degree of echogenicity should become a routine procedure in neonatal cerebral ultrasonography.     

Punctate white-matter lesions in the full-term newborn: Underlying aetiology and outcome

Background

Punctate white matter lesions (PWMLs) are small focal patches of increased signal intensity (SI) on T1- and decreased SI on T2-weighted magnetic resonance imaging (MRI). To date, there have been few reports of PWMLs in term born infants.

Dietary supplementation of long-chain polyunsaturated fatty acids in preterm infants: effects on cerebral maturation

Aim: To study the influence of dietary-supplied long-chain polyunsaturated fatty acids on structural brain maturation in preterm infants and to investigate parameters of functional brain development, relating them to structural maturation. Other studies have suggested that dietary supplementation of long-chain polyunsaturated fatty acids in preterm infants may enhance their visual development. The influence on structural brain development has never been evaluated. Methods: In a prospective, double-blind study, 42 formula-fed premature infants were randomized to be fed either a standard preterm formula without long-chain polyunsaturated fatty acids or an identical formula supplemented with docosahexaenoic acid (0.015 g/100 ml) and arachidonic acid (0.031 g/100 ml). Infants with significant cerebral damage, retinopathy, chronic disease or feeding problems were excluded. Follow-up was focused on assessment of cerebral myelination by MRI. Psychomotor, mental and visual development was analysed and flash-visual evoked potentials were recorded. Results: It was found that progress of myelination, mental and motor development and latencies of visual evoked potentials were not positively influenced by supplementation of long-chain polyunsaturated fatty acids. At each test age, visual acuity was slightly better in the supplemented infants than in the non-supplemented infants, but the difference never reached significance level Conclusion: Supplementation of long-chain polyunsaturated fatty acids did not have a demonstrable positive influence on structural brain maturation. Related to this finding, in this small cohort of preterm infants without significant neurological damage, sample size being restricted by strict inclusion criteria and MRI procedures, no significant positive effects were found on psychomotor, mental and visual development.     

Diagnostic imaging of brain maturation in premature infants

In 3 studies brain maturation in 42 preterm infants with no or minor cerebral deviations was examined with MRI. With a scoring system 5 stadia in gyral development were recognized, which corresponded to the gestational age (duration of amenorrhoea of the pregnant woman). At a gestational age between 30 and 34 weeks, myelin was present in many brain stem, diencephalic and cerebellar structures, but only in a few hemispheric structures. Little progress in myelination was noticed up to the gestational age of 46 weeks. Remnants of the germinal matrix formed a sharp contrast with the immature unmyelinated periventricular white matter and had a characteristic appearance on MR images before term age. Broad periventricular zones with subtle change of signal intensity were also physiological in this age group. Zones with more outspoken signal intensity change compared with the rest of the cerebral white matter were, however, not physiological and represent mild ischaemic change of the periventricular white matter.     

Delayed interval delivery in multiple pregnancies. Is optimism justified?

OBJECTIVE: Evaluation of the success of delayed interval delivery in multiple pregnancies. METHOD: Retrospective analyses of all multiple pregnancies with the birth of one child at a gestational age of 16-31 weeks (n=80). Three groups were defined: group I, unsuccessful attempt to temporize delivery, group II, interval between the first child and the other child or children 3 hours or more, with delivery of the remaining children before 28 weeks and group III, prolongation of pregnancy beyond 28 weeks. RESULTS: In 15 multiple pregnancies (ten sets of twins, five sets of triplets), the aim was to postpone the delivery of the second (and third) child. The mean gestational age at admittance was 25 weeks. Delay of the delivery of the second child was achieved in ten cases, five in group II and five in group III. In groups II and III, the mean interval of delivery was 12 days; the gestational age at the delivery of the remaining children in these ten patients was 27 5/7 weeks. No relation could be found between the reason for admittance and the interval in delivery between the first and the other children. The only severe maternal complication was blood loss exceeding 2 liters. In the neonatal outcome of first and second children (with a gestational age of 28 weeks or more) no striking differences were observed. CONCLUSION: Delayed delivery in multiple pregnancies after the birth of the first child is only successful in a minority of patients and should be considered prior to the birth of the first child.     

Differentiating normal myelination from hypoxic-ischemic encephalopathy on T1-weighted MR Images: a new approach

BACKGROUND AND PURPOSE: Hypoxic-ischemic cerebral changes can be difficult to distinguish from normal myelination on T1-weighted images. We hypothesized that comparing signal intensity (SI) of brain structures on T1-weighted images enables differentiation of myelination from hypoxic-ischemic brain damage. MATERIALS AND METHODS: T1-weighted images, obtained in 57 infants aged 1-104 days and born after a gestational age of 35 weeks or older, were retrospectively evaluated. Subjects were assigned to a patient (n = 23, with perinatal hypoxic-ischemic encephalopathy [HIE] stage 2/3) or a control group (n = 34). In each subject, an SI score was assigned to 19 brain structures on the basis of pairwise comparisons with the other 18 structures. In both groups, mean total SI scores were calculated for the 19 structures. Independent samples t tests assessed whether the mean total score of a structure differed significantly between the 2 groups. Logistic regression assessed which comparison was best to distinguish between the groups and to predict the presence of hypoxic-ischemic injury. RESULTS: In patients, mean total SI scores for posterolateral putamen (PP) and peri-Rolandic cortex (PC) were significantly higher (P = .000 for both). Mean total SI scores of the posterior limb of internal capsule (PLIC) and the corona radiata (CR) were significantly lower in patients (P = .000 and 0.005, respectively). Two comparisons (PLIC versus CR, PP versus PC) were best to distinguish patients and controls and to predict absence or presence of HIE (P < .0001). CONCLUSION: SI changes due to hypoxia-ischemia can be differentiated from normal myelination by comparing SI of 4 brain structures on T1-weighted images.     

The offspring of mothers with anorexia nervosa: A high-risk group for undernutrition and stunting?

Seven children from three families presented with stunting and low weight-for-height. Their mothers had a history of anorexia nervosa (AN). Evidence was gathered that the children were nourished insufficiently, possibly in combination with psychosocial deprivation. Low growth hormone secretion was documented in three cases. With the increasing ability to induce fertility in anorectic women one should be aware of the effects of maternal AN on the offspring.     

Brain ultrasound findings in neonates treated with intrauterine transfusion for fetal anaemia

Background

The main causes of severe fetal anaemia are red-cell allo-immunization, parvo B19 virus infection and feto-maternal haemorrhage. Treatment consists of intrauterine transfusion (IUT). Neuro-imaging studies in surviving neonates treated with IUT are scarce.

Aims

To assess if neonates treated with IUT for fetal anaemia are at risk for cerebral injury, report the incidence and severity of brain ultrasound (US) abnormalities and explore the relation between brain US findings and perinatal parameters and neurological outcome.

Patients and methods

Brain US scans of neonates born alive between 2001 and 2008 with at least one IUT were retrospectively reviewed and classified as normal, mildly or moderately/severely abnormal. Incidences of abnormalities were calculated for full-term and preterm neonates. Presence and severity of abnormalities were related to clinical and IUT related parameters and to neurological outcome around 2 years of age (adverse: moderate or severe disability; favourable: normal or mild disability).

Results

A total of 127 neonates (82 born preterm) were included. Median number of IUTs was 3 (range 1–6) and of brain US 2 (1–6). Median gestational age and weight at birth were 36.6 (26.0–41.1) weeks and 2870 (1040–3950) g. In 72/127 (57%) neonates ≥ 1 abnormality was seen on brain US, classified as moderate/severe in 30/127 (24%). Neurological outcome was adverse in 5 infants. Presence of brain US abnormalities was not significantly related to any of the perinatal parameters or to neurological outcome.

Conclusions

Neonates undergoing IUT for fetal anaemia are at high risk of brain injury.