scholarly journals Recent perspectives on the development of the central nervous system and the genetic background of neural tube defects

2009 ◽  
Vol 150 (19) ◽  
pp. 873-882 ◽  
Author(s):  
József Gábor Joó

Neural tube defects are rare and mostly lethal malformations. The pattern of inheritance of these malformations is multifactorial, rendering the identification of the underlying causes. Numerous studies have been conducted to elucidate the genetic basis of the development of the central nervous system. Essential signaling pathways of the development of the central nervous system include the planar cell polarity pathway, which is important for the initiation of neural tube closure as well as well as sonic hedhehog pathway, which regulates the neural plate bending. Genes and their mutations influencing the different stages of neurulation have been investigated for their eventual role in the development of these malformations. Among the environmental factors, folic acid seems to be the most important modifier of the risk of human neural tube defects. Genes of the folate metabolism pathways have also been investigated to identify mutations resulting in increased risk of NTDs. In this review the author has attempted to summarize the knowledge on neural tube defects, with special regard to genetic factors of the etiology.

2019 ◽  
Author(s):  
Jonathan M. Werner ◽  
Maraki Y. Negesse ◽  
Dominique L. Brooks ◽  
Allyson R. Caldwell ◽  
Jafira M. Johnson ◽  
...  

ABSTRACTPrimary neurulation is the process by which the neural tube, the central nervous system precursor, is formed from the neural plate. Incomplete neural tube closure occurs frequently, yet underlying causes remain poorly understood. Developmental studies in amniotes and amphibians have identified hingepoint and neural fold formation as key morphogenetic events and hallmarks of primary neurulation, the disruption of which causes neural tube defects. In contrast, the mode of neurulation in teleosts such as zebrafish has remained highly debated. Teleosts are thought to have evolved a unique pattern of neurulation, whereby the neural plate infolds in absence of hingepoints and neural folds (NFs), at least in the hindbrain/trunk where it has been studied. We report here on zebrafish forebrain morphogenesis where we identify these morphological landmarks. Our findings reveal a deeper level of conservation of neurulation than previously recognized and establish the zebrafish as a model to understand human neural tube development.


1979 ◽  
Vol 1 (6) ◽  
pp. 187-190
Author(s):  
Gerald S. Golden

The term "neural tube defects" refers to a biologically interrelated series of malformations of the central nervous system and overlying tissues. There is an abnormality in morphogenesis of the brain and/or spinal cord, associated with varying degrees of absence or malformation of the meninges, bone, muscle, and skin. In addition to morphologic similarities, these lesions are related epidemiologically and probably genetically. The terminology is complex, but the lesions can be placed in a simple framework. The Table outlines the most common defects. The malformation occurs early in embryonic development, since the gross structure of the central nervous system has been completed by the 26th gestational day. There are numerous theories of pathogenesis and there is a good deal of subprimate teratologic research, but no single etiologic hypothesis is widely accepted or rigorously proven. Despite this, clinical risk factors have been clearly defined and empiric techniques for prenatal diagnosis have been developed. FREQUENCY AND EPIDEMIOLOGY Neural tube defects represent one of the most common groups of major congenital malformations. Each year approximately 6,000 to 8,000 infants are born with these conditions in the United States. Incidence rates vary among different groups from 0.6 to 4.1/1,000 total births for anencephaly. The risk is not uniformly spread over the entire population; a number of factors are related to initial occurrence and recurrence.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Jonathan M. Werner ◽  
Maraki Y. Negesse ◽  
Dominique L. Brooks ◽  
Allyson R. Caldwell ◽  
Jafira M. Johnson ◽  
...  

AbstractPrimary neurulation is the process by which the neural tube, the central nervous system precursor, is formed from the neural plate. Incomplete neural tube closure occurs frequently, yet underlying causes remain poorly understood. Developmental studies in amniotes and amphibians have identified hingepoint and neural fold formation as key morphogenetic events and hallmarks of primary neurulation, the disruption of which causes neural tube defects. In contrast, the mode of neurulation in teleosts has remained highly debated. Teleosts are thought to have evolved a unique mode of neurulation, whereby the neural plate infolds in absence of hingepoints and neural folds, at least in the hindbrain/trunk where it has been studied. Using high-resolution imaging and time-lapse microscopy, we show here the presence of these morphological landmarks in the zebrafish anterior neural plate. These results reveal similarities between neurulation in teleosts and other vertebrates and hence the suitability of zebrafish to understand human neurulation.


2016 ◽  
Vol 52 (5) ◽  
pp. 319-324 ◽  
Author(s):  
Stephanie Engel ◽  
Karen Marie Hilling ◽  
Travis Kuder Meuten ◽  
Chad Brendan Frank ◽  
Angela J. Marolf

ABSTRACT Primary hypodipsic hypernatremia is a rarely reported disease in dogs. Reported underlying causes associated with this disease in dogs include congenital malformations, encephalitis, intracranial neoplasia, and pressure atrophy of the hypothalamus secondary to hydrocephalus. The dog in this report had an infiltrative neoplastic disorder, likely causing damage to the hypothalamic osmoreceptors responsible for the thirst generation. The neoplastic process was identified histopathologically as glioblastoma multiforme, an unusual tumor to occur in a dog this young. A tumor of the central nervous system causing physical destruction of the osmoreceptors has rarely been reported in dogs and none of the previously reported cases involved a glial cell tumor.


Paediatric neurology services care for children aged 0–16 years. Many of these children suffer genetic and complex neurological problems and frequently require life-long support. Hydrocephalus and central nervous system tumours are commonly presenting disorders; however, craniofacial syndromes, spinal disorders, spinal neural tube defects, epilepsy, and trauma including non-accidental injuries are frequently managed. Paediatric nurses specialize in the care of these children and support of their families but as they grow up and transition into adult services, it is the responsibility of general nurses to have a basic understanding of some of their conditions so they can maintain and continue their care.


2020 ◽  
pp. 237-238
Author(s):  
John F. Peppin ◽  
Joseph V. Pergolizzi ◽  
Robert B. Raffa ◽  
Steven L. Wright

The authors summarize the harmful and understudied aspects of the overuse of benzodiazepines. Increased and longer-term use of benzodiazepines has been observed to lead to side effects such as sedation, cognitive issues, abuse, and dependence, as well as many other unanticipated side effects that do not fit their known mechanism of action in the central nervous system. Data also shows a correlation between concomitant use of benzodiazepines and opioids and increased risk of death from overdose. The authors advocate for stricter guidelines for prescribing benzodiazepines, as well as close clinical monitor and shorter-term treatment plans.


Author(s):  
Peggy Mason

The central nervous system develops from a proliferating tube of cells and retains a tubular organization in the adult spinal cord and brain, including the forebrain. Failure of the neural tube to close at the front is lethal, whereas failure to close the tube at the back end produces spina bifida, a serious neural tube defect. Swellings in the neural tube develop into the hindbrain, midbrain, diencephalon, and telencephalon. The diencephalon sends an outpouching out of the cranium to form the retina, providing an accessible window onto the brain. The dorsal telencephalon forms the cerebral cortex, which in humans is enormously expanded by growth in every direction. Running through the embryonic neural tube is an internal lumen that becomes the cerebrospinal fluid–containing ventricular system. The effects of damage to the spinal cord and forebrain are compared with respect to impact on self and potential for improvement.


2019 ◽  
Vol 75 (5) ◽  
pp. 1003-1009 ◽  
Author(s):  
Shelly L Gray ◽  
Zachary A Marcum ◽  
Sascha Dublin ◽  
Rod Walker ◽  
Negar Golchin ◽  
...  

Abstract Background It is well established that individual medications that affect the central nervous system (CNS) increase falls risk in older adults. However, less is known about risks associated with taking multiple CNS-active medications. Methods Employing a new user design, we used data from the Adult Changes in Thought study, a prospective cohort of community-dwelling people aged 65 and older without dementia. We created a time-varying composite measure of CNS-active medication exposure from electronic pharmacy fill data and categorized into mutually exclusive categories: current (within prior 30 days), recent (31–90 days), past (91–365 days), or nonuse (no exposure in prior year). We calculated standardized daily dose and identified new initiation. Cox proportional hazards models examined the associations between exposures and the outcome of fall-related injury identified from health plan electronic databases. Results Two thousand five hundred ninety-five people had 624 fall-related injuries over 15,531 person-years of follow-up. Relative to nonuse, fall-related injury risk was significantly greater for current use of CNS-active medication (hazard ratio [HR] = 1.95; 95% CI = 1.57–2.42), but not for recent or past use. Among current users, increased risk was noted with all doses. Risk was increased for new initiation compared with no current use (HR = 2.81; 95% CI = 2.09–3.78). Post hoc analyses revealed that risk was especially elevated with new initiation of opioids. Conclusions We found that current use, especially new initiation, of CNS-active medications was associated with fall-related injury in community-dwelling older adults. Increased risk was noted with all dose categories. Risk was particularly increased with new initiation of opioids.


2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Meifang Yang ◽  
Xuan Zhang ◽  
Jianhua Hu ◽  
Hong Zhao ◽  
Lanjuan Li

Background. Cryptococcosis following kidney transplantation (KT) is rare but is associated with considerably increased risk of mortality. At present, data on the association between cryptococcosis and KT in mainland China remain relatively limited. Objectives. This study aims to review our experience related to the management of cryptococcosis following KT at a Chinese tertiary hospital. Methods. All patients with cryptococcosis following KT admitted to our hospital from January 2010 to December 2018 were reviewed. Results. A total of 37 patients with cryptococcosis were enrolled (males: 62.2%). The mean age of the patients was 49.5 ± 9.38 (20–64) years. The average time to infection following KT was 7.0 ± 5.50 years (5 months to 21 years), and 30 patients (81.1%) had cryptococcosis onset >2 years following transplantation. The most common site of infection was the central nervous system, followed by the pulmonary system and skin. Most patients received fluconazole or voriconazole with or without flucytosine as their initial treatment regimen at our hospital. The 2-week mortality rate was 8.1% (3/37), and five patients (13.5%) died within 6 months of being diagnosed with cryptococcosis. Remarkably, all patients who received high-dose fluconazole (800 mg daily) or voriconazole ± flucytosine survived. Conclusions. Cryptococcosis in kidney transplant recipients is typically a late-occurring infection, with most patients having cryptococcosis onset >2 years following KT at our hospital. The central nervous system, pulmonary system, and skin are the main sites of infection. Voriconazole or high-dose fluconazole can be used as an alternative therapy for post-KT cryptococcosis.


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