A central role for Necl4 (SynCAM4) in Schwann cell-axon interaction and myelination

Myelination in the peripheral nervous system requires close contact between Schwann cells and the axon, but the underlying molecular basis remains largely unknown. Here we show that cell adhesion molecules (CAMs) of the nectin-like (Necl, also known as SynCAM or Cadm) family mediate Schwann cell-axon interaction during myelination. Necl4 is the main Necl expressed by myelinating Schwann cells and is located along the internodes in direct apposition to Necl1, which is localized on axons. Necl4 serves as the glial binding partner for axonal Necl1, and the interaction between these two CAMs mediates Schwann cell adhesion. The disruption of the interaction between Necl1 and Necl4 by their soluble extracellular domains, or the expression of a dominant-negative Necl4 in Schwann cells, inhibits myelination. These results suggest that Necl proteins are important for mediating axon-glia contact during myelination in peripheral nerves.     

Factors associated with increased risk of insulin pump discontinuation in pediatric patients with type 1 diabetes

de Vries L, Grushka Y, Lebenthal Y, Shalitin S, Phillip M. Factors associated with increased risk of insulin pump discontinuation in pediatric patients with type 1 diabetes. Background: There are few reports on rates and predictors for pump discontinuation in the pediatric population. Objective: To study the rate of and predictors for insulin pump discontinuation among pediatric patients with type 1 diabetes. Methods: Medical chart review of 530 patients with type 1 diabetes who had started pump therapy between 2000 and 2008 in our center revealed that 11.3% had discontinued pump use after 3 d to 5 yr; of these, 9.1% discontinued pump use at least 3 months after initiation. Relevant data were retrieved from the files of these patients and from those of 100 randomly assigned pump‐treated patients. Results: The pump discontinuation group had a significantly higher proportion of female patients (75 vs. 46%, p = 0.001) and patients above 10 yr of age (93.8 vs. 80%, p = 0.03) than the reference group. Comparable findings were noted for age at diagnosis, pubertal stage, anthropometric data and duration of diabetes at pump initiation, rate of severe hypoglycemic and diabetic ketoacidosis episodes. There were no between‐group differences in number of daily insulin injections and blood glucose measurements before pump treatment. At pump initiation, HbA_1c was significantly higher in patients discontinuing pump therapy than in the controls (8.6 ± 1.4 vs. 8.1 ± 1.0, p = 0.02). This difference was maintained at the last follow‐up visit recorded. Conclusions: Almost 90% of our cohort maintained pump therapy. Female gender, age older than 10 years in girls and poor metabolic control at pump initiation were associated with higher risk for pump discontinuation – for such patients intensified individual and family support may serve to maximize persistent pump therapy.     

Leukocyte adhesiveness/aggregation test (LAAT) to discriminate between viral and bacterial infections in children

Objectives: We previously noted that white blood cells (WBC) have increased adhesive properties during bacterial infections. Here, we aim to explore the possibility of using the different adhesive properties of WBC as a means of differentiating between viral and bacterial infections, a common problem in paediatrics. Methods: The adhesive properties of WBC in the peripheral blood of 25 children with documented bacterial infections, 15 with documented viral infections and 36 with probable viral infections, were studied by means of a leukocyte adhesiveness/aggregation slide test (LAAT). The results of the LAAT were compared with those of the other acute phase reactants, namely WBC, differential count and erythrocyte sedimentation rate (ESR), which were taken in the same blood sample in each patient. Results: The sensitivity, specificity and positive predictive value were 92%, 96%, and 92%, respectively for the LAAT; 83%, 87% and 80% for the ESR; 56%, 78% and 56% for the white blood cell count; and 54%, 74% and 50% for the differential count. Conclusions: The presence of bacterial infections in children can be tested using a simple slide test to reveal the increased state of leukocyte adhesiveness/aggregation in the peripheral blood. The LAAT is a reliable, rapid and inexpensive test, and it can be a useful laboratory tool for the paediatrician treating a child with acute febrile illness.     

The Utility of Routine Ultrasound in the Diagnosis and Management of Adolescents with Abnormal Uterine Bleeding

Study Objective

Despite the fact that most cases of abnormal uterine bleeding (AUB) in adolescence are due to an immature hypothalamic-pituitary-ovarian (HPO) axis, the current approach to investigating adolescents who present with AUB often includes pelvic ultrasound to exclude rare structural causes. The aim of this study was to determine whether an ultrasound ordered for the investigation of AUB in adolescents detects any significant anatomic pathology or alters diagnosis and management.

Does gender of the fetus have any relation with fetal heart monitoring during the first and second stage of labor?

Objective: To investigate fetal gender and its influences on neonatal outcomes, taking into consideration the available tools for the assessment of fetal well-being.

Methods: We conducted a retrospective study comparing maternal, fetal and neonatal outcomes according to fetal gender, in women carrying a singleton gestation.

A multivariate analysis was performed for the prediction of adverse neonatal outcomes according to fetal gender, after adjustment for gestational age, maternal age and fetal weight.

Results: A total of 682 pregnancies were included in the study, of them 56% (n?=?383) were carrying a male fetus and 44% (n?=?299) a females fetus. Male gender was associated with a significant higher rate of abnormal fetal heart tracing patterns during the first (67.7% versus 55.1, p?=?0.001) and the second stage (77.6 versus 67.7, p?=?0.01) of labor. Male gender was also significantly associated with lower Apgar scores at 1' (19.1% versus 10.7%, p?p?2, PO₂) compared with female fetuses. In the multivariate analysis, male gender was found to be significantly associated with first (OR 1.76, 95% CI 1.28–2.43, p?=?0.001) and second stage (OR 1.73, 95% CI 1.20–2.50, p?Conclusions: The present study confirms the general trend of a lower clinical performance of male neonates compared with females. In addition, the relation between fetal heart rate patterns during all stages of labor and fetal gender showed an independent association between male fetal gender and abnormal fetal heart monitoring during labor.     

Fetal heart rate monitoring category 3 during the 2nd stage of labor is an independent predictor of fetal acidosis

Objective: To determine whether fetal heart rate (FHR) monitoring categories during the 1st and 2nd stage of labor can predict arterial cord pH?<7.2.

Materials and methods: A case control study was conducted including 653 consecutive term deliveries (37 weeks gestation and above) that were divided according to fetal pH?≤?7.2 (n?=?315) and fetal pH?>?7.2 (n?=?338). Deliveries occurred during the year 2013 in tertiary medical center, where arterial cord pH is routinely taken after birth. Intrapartum FHR monitoring categorization was defined according to the ACOG committee guidelines by two obstetricians. Multivariable models were constructed to control for confounders.

Results: Variable decelerations, late decelerations and bradycardia during the 1st and 2nd stages of labor were significantly higher in group of deliveries ended in cord pH??7.2. A significant association was observed between category 2 and 3 during the 1st stage of labor and pH?≤?7.2. However, while controlling for FHR category 3 at the 2nd stage of labor, 1st stage categorization lost its association with pH?<7.2, and only category 3 during the 2nd stage were noted as an independent risk factor for acidosis.

Conclusion: FHR monitoring category 3 during the 2nd stage of labor is an independent predictor of fetal acidosis as expressed by arterial cord pH?相似文献   

Meconium-stained amniotic fluid – risk factors and immediate perinatal outcomes among SGA infants

Objective: To detect factors that are associated with meconium-stained amniotic fluid (MSAF) among deliveries of small for gestational age (SGA) neonates and to identify perinatal outcomes of deliveries of SGA infants complicated with MSAF.

Methods: A population-based study comparing deliveries of SGA neonates with and without MSAF was conducted. Deliveries occurred during the years 1988–2007 at the Soroka University Medical Center. Risk factors for MSAF among SGA infants were evaluated. Incidence of adverse pregnancy outcomes were compared between deliveries of SGA neonates with and without MSAF.

Results: During the study period 9583 deliveries were of SGA neonates. Of these, 16.6% (n?=?1597) were complicated with MSAF. Among SGA neonates, older maternal age, multiparty, lack of prenatal care and weight were significantly associated with MSAF. Having delivered an SGA infant with MSAF was associated with decreased rates of induction of labor and increased rates of labor dystocia, delivery by cesarean section and fetal distress. Using multivariable regression models, having delivered an SGA infant with MSAF was independently associated with fetal distress.

Conclusion: Among SGA neonates, deliveries complicated with MSAF are associated with additional adverse pregnancy outcomes.