Review: Glial lineages and myelination in the central nervous system

Oligodendrocytes, derived from stem cell precursors which arise in subventricular zones of the developing central nervous system, have as their specialist role the synthesis and maintenance of myelin. Astrocytes contribute to the cellular architecture of the central nervous system and act as a source of growth factors and cytokines; microglia are bone-marrow derived macrophages which function as primary immunocompetent cells in the central nervous system. Myelination depends on the establishment of stable relationships between each differentiated oligodendrocyte and short segments of several neighbouring axons. There is growing evidence, especially from studies of glial cell implantation, that oligodendrocyte precursors persist in the adult nervous system and provide a limited capacity for the restoration of structure and function in myelinated pathways damaged by injury or disease.     

Renal Kallikrein Excretion in Alcoholic Cirrhosis

Severe liver disease is often associated with renal hemodynamic changes, and these changes may involve vasoactive hormones. The vasodilatory renal kallikrein-kinin system has received little previous study in these patients. We measured urinary kallikrein in nine patients with alcoholic cirrhosis under rigid metabolic conditions and simultaneously evaluated renin, aldosterone and urinary prostaglandins. Plasma renin und aldosterone were generally increased as expected but urinary kallikrein was surprisingly diminished (13.3 ± 3.7 vs. 38.8 ± 11.1 SE, E.U./day. P < 0.05). despite adequate creatinine clearance (81 ± 9 ml./min.). Administration of prostaglandin inhibitors reduced urinary prostaglandin E by 72% and creatinine clearance by 56% but did not alter urinary kallikrein. Mineralocor-ticoid inhibition by spironolactone induced a natriuresis in four patients with ascites (from 1.4–140 mEq. Na⁺/day) but also failed to alter kallikrein. Thus, kallikrein excretion is paradoxically reduced and seemingly unresponsive to alterations in the prostaglandin and renin-aldosterone systems. If urinary kallikrein quantitatively reflects intrarenal kallikrein-kinin activity, the impairment in this vasodilatory system may mediate the altered renal hemodynamics of severe liver disease.     

Obstetric brachial plexus palsy: a prospective,population‐based study of incidence,recovery, and residual impairment at 18 months of age

Aim The aim of this investigation was to study the incidence of obstetric brachial plexus palsy (OBPP), to prospectively follow the recovery process, to assess the functional outcome at 18 months of age, and to find early prognostic indicators. Method Of the 38 749 children born between 1999 and 2001 in western Sweden, 114 (70 males, 44 females) had an OBPP. Ninety‐eight children were examined on six occasions at up to 18 months of age. Muscle strength, range of motion, hand preference, and functional abilities were noted, and the severity of the OBPP was classified. Results The incidence of OBPP was 2.9 per 1000 live births, and the incidence of persisting OBPP was 0.46 per 1000. At 3 months of age, the predictive value of regained elbow flexion for complete recovery was 100%, 99% of shoulder external rotation, and 96% of forearm supination. Most of the 18 children with persisting OBPP could perform functional activities but asymmetries were noted. Five children had a mild, 11 had a moderate, and two had a severe impairment. Three had undergone nerve surgery, one with a mild and two with a severe persisting impairment. Interpretation Most children with an OBPP recover completely. Muscle strength at 3 months of age can be used to predict outcome.     

Child abuse study among Swedish physicians and medical students

Background: The purpose of the present paper was to examine the attitudes and experiences of reporting child abuse and neglect among primary care and hospital‐based physicians and to study the responses of physicians and medical students to case vignettes suggestive of possible physical abuse or neglect. Methods: Physicians at the child health centers in Göteborg primary care (n= 44) and the general pediatricians at the pediatric hospital (n= 21) in Göteborg answered a questionnaire regarding their attitude and experiences reporting child abuse and neglect. The physicians and medical students (n= 34) responded to three case vignettes in which child abuse and neglect could be suspected. Results: A majority of the physicians had reported child abuse and neglect to the social services (80%). No differences were found between primary care and hospital‐based physicians in terms of reporting or attitudes. Two‐thirds of the physicians had suspected child abuse and neglect and decided not to report, and the major reason for not reporting was a lack of confidence in social services organization. Twenty‐one percent had never reported a child for abuse or neglect during their working career. Medical students were more likely to report hypothetical cases than physicians. Conclusion: Many physicians have reported child abuse to social services but also have neglected to do so even when suspecting abuse. It is important that medical students’ willingness to report is continued when starting to work clinically and that all physicians should be continuously educated.     

Serum ferritin in term and preterm infants

Serum ferritin levels were examined in maternal serum, In cord sera and at one, four, eight and twelve weeks in 19 term and 28 preterm infants. There was no correlation between maternal and cord ferritin levels. Mean serum ferritin concentration was lower in preterm infants, and both term and preterm Infants exhibited' an initial rise in serum ferritin concentration followed by a steady fall. Serum ferritin concentration showed a good correlation with calculated iron stores at twelve weeks of age suggesting that serum ferritin estimation is the method of choice for monitoring body iron stores in infants. No correlation was found between serum ferritin concentration and calculated iron intake at any age in either term or preterm infants. It is suggested that iron supplementation additional to that present in modified cow's milk is not necessary for the first twelve weeks of life in either term or preterm infants.     

Morphogenesis and Regulation of Bergmann Glial Processes During Purkinje Cell Dendritic Spine Ensheathment and Synaptogenesis

星形胶质细胞在突触形成中发挥重要作用,但星形胶质细胞突起如何在发育过程中与突触结构相联系还不是很清楚。本文分析在小脑突触发生过程中Bergmann胶质细胞(BG)突起生长的类型。本文发现在这个过程中,BG突起向外生长与树突棘增多的包被作用相关。此外,双光子时间分辩显像显示BG突起是高度动态的,在棘包被过程中突起趋于稳定。虽然突触活力依赖于肌动蛋白的聚合作用,但细胞骨架调节器Rac1和RhoG的活动在胶质细胞突起的动力或密度上并未发挥作用,而是对于保持突起长度起关键性作用。本文扩展这个发现,探查突起形态和包被之间的关系,发现缩短的突起导致棘覆盖的减少。本文进一步发现在BG表达dn-Rac1和低水平突触包被的区域,显示突触数量的增加。这些分析提示BG突起如何生长并包围突触结构,阐明BG突起结构对突触包被适当发育的重要性,并提示包被在突触形成中的作用。     

Diaphragm Pacing with a Quadripolar Phrenic Nerve Electrode: An International Study

We sought to determine the international experience with the quadripolar diaphragm pacer system and to test two hypotheses: the incidence of pacer complications would be (1) increased among pediatric as compared to adult patients; and (2) highest among active pediatric patients with idiopathic congenital central hypoventilation syndrome (CCHS). Data were collected via a questionnaire coupled with the Atrotech Registry data for a total of 64 patients (35 children and 29 adults) from 14 countries. Thoracic implantation of electrodes and bilateral pacer use each occurred in 94% of all subjects. Tetraplegic (vs pediatric CCHS) patients were more typically paced 24 hours/day (P = 0.001). Pacing duration averaged 2.0 ± 1.0 years among children and 2.2 ± 1.1 years among adults. Infections occurred among 2.9% of surgical procedures, all in pediatric CCHS patients (vs pediatric tetraplegic patients, P = 0.01). The incidence of mechanical trauma was 3.8%, without significant differences among patient groups. The incidence of presumed electrode and receiver failure were 3.1% and 5.9%, respectively, with internal component failure greater among pediatric CCHS than pediatric tetraplegic patients (P < 0.01). Intermittent or absent function of 0–4 electrode combinations occurred among 19% of all patients, with increased frequency among pediatric CCHS than pediatric tetraplegic patients (P < 0.03). Complication- free successful pacing occurred in 60% of pediatric and 52% of adult patients. In all, 94 % of the pediatric and 86% of the adult patients paced successfully after the necessary intervention. Although pacer complications were not increased among pediatric as compared to adult patients, the incidence of complications was highest among the active pediatric patients with CCHS. Longitudinal study of these patients will provide invaluable information for modification and improvement of the quadripolar system.