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1.
Reprod Toxicol ; 93: 199-210, 2020 04.
Article En | MEDLINE | ID: mdl-32126282

The framework for developmental toxicity testing has remained largely unchanged for over 50 years and although it remains invaluable in assessing potential risks in pregnancy, knowledge gaps exist, and some outcomes do not necessarily correlate with clinical experience. Advances in omics, in silico approaches and alternative assays are providing opportunities to enhance our understanding of embryo-fetal development and the prediction of potential risks associated with the use of medicines in pregnancy. A workshop organised by the Medicines and Healthcare products Regulatory Agency (MHRA), "Predicting the Safety of Medicines in Pregnancy - a New Era?", was attended by delegates representing regulatory authorities, academia, industry, patients, funding bodies and software developers to consider how to improve the quality of and access to nonclinical developmental toxicity data and how to use this data to better predict the safety of medicines in human pregnancy. The workshop delegates concluded that based on comparative data to date alternative methodologies are currently no more predictive than conventional methods and not qualified for use in regulatory submissions. To advance the development and qualification of alternative methodologies, there is a requirement for better coordinated multidisciplinary cross-sector interactions coupled with data sharing. Furthermore, a better understanding of human developmental biology and the incorporation of this knowledge into the development of alternative methodologies is essential to enhance the prediction of adverse outcomes for human development. The output of the workshop was a series of recommendations aimed at supporting multidisciplinary efforts to develop and validate these alternative methodologies.


Drug-Related Side Effects and Adverse Reactions , Maternal-Fetal Exchange , Adverse Outcome Pathways , Animal Testing Alternatives , Animals , Drug Evaluation, Preclinical , Drug and Narcotic Control , Female , Humans , Pregnancy , Quantitative Structure-Activity Relationship , Toxicity Tests
2.
Diabet Med ; 37(8): 1357-1366, 2020 08.
Article En | MEDLINE | ID: mdl-31808578

AIMS: To assess fidelity of the Healthier You: NHS Diabetes Prevention Programme (NHS-DPP), a behavioural intervention for people in England at high risk of developing type 2 diabetes, to the specified programme features. METHODS: Document analysis of the NHS-DPP programme specification, including National Institute for Health and Care Excellence (NICE) PH38 diabetes prevention guidance. This was compared with the intervention design (framework response documents and programme manuals) from all four independent providers delivering the NHS-DPP. Documents were coded using the Template for Intervention Description and Replication framework (describing service parameters) and the Behaviour Change Technique Taxonomy v1. RESULTS: Providers demonstrated good fidelity to service parameters of the NHS-DPP. The NHS-DPP specification indicated 19 unique behaviour change techniques. Framework responses for the four providers contained between 24 and 32 distinct behaviour change techniques, and programme manuals contained between 23 and 45 distinct behaviour change techniques, indicating variation in behaviour change content between providers' intervention documents. Thus, each provider planned to deliver 74% of the unique behaviour change techniques specified, and a large amount of behaviour change content not mandated. CONCLUSIONS: There is good fidelity to the specified service parameters of the NHS-DPP; however, the four providers planned to deliver approximately three-quarters of behaviour change techniques specified by the NHS-DPP. Given that behaviour change techniques are the 'active ingredients' of interventions, and some of these techniques in the programme manuals may be missed in practice, this highlights possible limitations with fidelity to the NHS-DPP programme specification at the intervention design stage.


Diabetes Mellitus, Type 2/prevention & control , Program Evaluation , Psychosocial Intervention/standards , Behavior Therapy/standards , England , Humans , State Medicine , United Kingdom
5.
Br J Sports Med ; 51(1): 12-19, 2017 Jan.
Article En | MEDLINE | ID: mdl-27697939

OBJECTIVE: To assess the relationships between golf and health. DESIGN: Scoping review. DATA SOURCES: Published and unpublished reports of any age or language, identified by searching electronic databases, platforms, reference lists, websites and from consulting experts. REVIEW METHODS: A 3-step search strategy identified relevant published primary and secondary studies as well as grey literature. Identified studies were screened for final inclusion. Data were extracted using a standardised tool, to form (1) a descriptive analysis and (2) a thematic summary. RESULTS AND DISCUSSION: 4944 records were identified with an initial search. 301 studies met criteria for the scoping review. Golf can provide moderate intensity physical activity and is associated with physical health benefits that include improved cardiovascular, respiratory and metabolic profiles, and improved wellness. There is limited evidence related to golf and mental health. The incidence of golfing injury is moderate, with back injuries the most frequent. Accidental head injuries are rare, but can have serious consequences. CONCLUSIONS: Practitioners and policymakers can be encouraged to support more people to play golf, due to associated improved physical health and mental well-being, and a potential contribution to increased life expectancy. Injuries and illnesses associated with golf have been identified, and risk reduction strategies are warranted. Further research priorities include systematic reviews to further explore the cause and effect nature of the relationships described. Research characterising golf's contribution to muscular strengthening, balance and falls prevention as well as further assessing the associations and effects between golf and mental health are also indicated.


Golf/physiology , Health Status , Back Injuries/epidemiology , Craniocerebral Trauma/epidemiology , Exercise , Golf/injuries , Humans , Mental Health
6.
Placenta ; 43: 35-40, 2016 07.
Article En | MEDLINE | ID: mdl-27324097

OBJECTIVE: The aim of this work was to evaluate whether the uterine arteries (UtA) could be identified and their flow profiles measured during a fetal MRI examination. A comparison was performed against same day sonographic Doppler assessment. METHODS: 35 normal, healthy, singleton pregnancies at 28-32 weeks gestation underwent routine Doppler examination, followed by MRI examination. The resistivity index (RI) and pulsatility index (PI) of the left and right UtA were measured using phase contrast MRI. Bland Altman statistics were used to compare MRI and ultrasound results. RESULTS: Sixty-nine comparable vessels were analysed. Six vessels were excluded due to artefact or technical error. Bland-Altman analysis demonstrated the ultrasound indices were comparable, although systematically lower than the MRI indices; Right UtA RI bias -0.03 (95% limits of agreement (LOA) -0.27 to +0.20), and left UtA RI bias -0.06 (95% LOA -0.26 to +0.14); Right UtA PI bias -0.06 (95% LOA -0.50 to +0.38), Left UtA PI bias -0.11 (95% LOA -0.54 to +0.32). The inter-rater agreement for the MRI derived PI and RI analysis was good. CONCLUSION: This study demonstrates that in the majority of early third trimester pregnancies, the uterine arteries can be identified, and their flow profiles measured using MRI, and that the derived PI and RI values are comparable with Doppler ultrasound values.


Magnetic Resonance Imaging , Pregnancy Trimester, Third/physiology , Ultrasonography, Doppler , Uterine Artery/diagnostic imaging , Vascular Resistance/physiology , Female , Humans , Pregnancy , Pulsatile Flow/physiology , Uterine Artery/physiology
8.
Br J Sports Med ; 50(11): 647-50, 2016 Jun.
Article En | MEDLINE | ID: mdl-27130924

INTRODUCTION: Golf is a sport played in 206 countries worldwide by over 50 million people. It is possible that participation in golf, which is a form of physical activity, may be associated with effects on longevity, the cardiovascular, metabolic and musculoskeletal systems, as well as on mental health and well-being. We outline our scoping review protocol to examine the relationships and effects of golf on physical and mental health. METHODS AND ANALYSIS: Best practice methodological frameworks suggested by Arksey and O'Malley, Levac et al and the Joanna Briggs Institute will serve as our guide, providing clarity and rigour. A scoping review provides a framework to (1) map the key concepts and evidence, (2) summarise and disseminate existing research findings to practitioners and policymakers and (3) identify gaps in the existing research. A three-step search strategy will identify reviews as well as original research, published and grey literature. An initial search will identify suitable search terms, followed by a search using keyword and index terms. Two reviewers will independently screen identified studies for final inclusion. DISSEMINATION: We will map key concepts and evidence, and disseminate existing research findings to practitioners and policymakers through peer-reviewed and non-peer reviewed publications, conferences and in-person communications. We will identify priorities for further study. This method may prove useful to examine the relationships and effects of other sports on health.


Golf/psychology , Mental Health , Research Design , Databases, Factual , Humans
9.
Eur Radiol ; 26(10): 3752-9, 2016 Oct.
Article En | MEDLINE | ID: mdl-26792428

OBJECTIVES: This work evaluates rapid magnetic resonance projection hydrography (PH) based amniotic fluid volume (AFV) estimates against established routine ultrasound single deepest vertical pocket (SDVP) and amniotic fluid index (AFI) measurements, in utero at 28-32 weeks gestation. Manual multi-section planimetry (MSP) based measurement of AFV is used as a proxy reference standard. METHODS: Thirty-five women with a healthy singleton pregnancy (20-41 years) attending routine antenatal ultrasound were recruited. SDVP and AFI were measured using ultrasound, with same day MRI assessing AFV with PH and MSP. The relationships between the respective techniques were assessed using linear regression analysis and Bland-Altman method comparison statistics. RESULTS: When comparing estimated AFV, a highly significant relationship was observed between PH and the reference standard MSP (R(2) = 0.802, p < 0.001). For the US measurements, SDVP measurement related most closely to amniotic fluid volume, (R(2) = 0.470, p < 0.001), with AFI demonstrating a weaker relationship (R(2) = 0.208, p = 0.007). CONCLUSION: This study shows that rapid MRI based PH measurement is a better predictor of AFV, relating more closely to our proxy standard than established US techniques. Although larger validation studies across a range of gestational ages are required this approach could form part of MR fetal assessment, particularly where poly- or oligohydramnios is suspected. KEY POINTS: • MR projection hydrography can be used to estimate amniotic fluid volume. • MR projection hydrography relies on the T2w signal from amniotic fluid. • Amniotic fluid volume (AFV) is more accurately assessed than with ultrasound.


Amniotic Fluid/diagnostic imaging , Magnetic Resonance Imaging/methods , Prenatal Diagnosis/methods , Adult , Female , Gestational Age , Humans , Observer Variation , Pregnancy , Ultrasonography, Prenatal , Young Adult
11.
Front Neuroanat ; 6: 10, 2012.
Article En | MEDLINE | ID: mdl-22493569

The patterning of the embryonic cerebellum is vital to establish the elaborate zone and stripe architecture of the adult. This review considers early stages in cerebellar Purkinje cell patterning, from the organization of the ventricular zone to the development of Purkinje cell clusters-the precursors of the adult stripes.

12.
Clin Radiol ; 66(11): 1049-54, 2011 Nov.
Article En | MEDLINE | ID: mdl-21763645

AIM: To document the timing of the appearance of the radiological features of fracture healing in a group of infants in which the date of injury was known and to assess the degree of interobserver agreement. MATERIALS AND METHODS: Three paediatric radiologists independently assessed 161 images of 37 long bone fractures in 31 patients aged 0-44 months. The following features were assessed: soft-tissue swelling, subperiosteal new bone formation (SPNBF), definition of fracture line, presence or absence of callus, whether callus was well or ill defined, and the presence of endosteal callus. RESULTS: Agreement between observers was only moderate for all discriminators except SPNBF. SPNBF was invariably seen after 11 days but was uncommon before this time even in the very young. In one case SPNBF was seen at 4 days. CONCLUSION: With the exception of SPNBF, the criteria relied on to date fractures are either not reproducible or are poor discriminators of fracture age.


Femoral Fractures/diagnostic imaging , Fracture Healing , Humeral Fractures/diagnostic imaging , Radius Fractures/diagnostic imaging , Tibial Fractures/diagnostic imaging , Ulna Fractures/diagnostic imaging , Child, Preschool , Female , Femoral Fractures/physiopathology , Humans , Humeral Fractures/physiopathology , Infant , Infant, Newborn , Male , Observer Variation , Radiography , Radius Fractures/physiopathology , Retrospective Studies , Tibial Fractures/physiopathology , Time Factors , Ulna Fractures/physiopathology
13.
J Bone Joint Surg Br ; 92(7): 1013-6, 2010 Jul.
Article En | MEDLINE | ID: mdl-20595124

We present the results of treatment of developmental dysplasia of the hip in infancy with the Pavlik harness using a United Kingdom screening programme with ultrasound-guided supervision. Initially, 128 consecutive hips in 77 patients were reviewed over a 40-month period; 123 of these were finally included in the study. The mean age of the patients at the start of treatment was five weeks (1 to 12). All hips were examined clinically and monitored with ultrasound scanning. Failure of treatment was defined as an inability to maintain reduction with the harness. All hips diagnosed with dysplasia or subluxation but not dislocation were managed successfully in the harness. There were 43 dislocated hips, of which 39 were reducible, but six failed treatment in the harness. There were four dislocated but irreducible hips which all failed treatment in the harness. One hip appeared to be successfully treated in the harness but showed persistent radiological dysplasia at 12 and 24 months. Grade 1 avascular necrosis was identified radiologically in three patients at 12 months.


Hip Dislocation, Congenital/therapy , Orthotic Devices , Ultrasonography, Interventional/methods , Epidemiologic Methods , Femur Head Necrosis/etiology , Hip Dislocation, Congenital/diagnostic imaging , Humans , Infant , Infant, Newborn , Orthotic Devices/adverse effects , Treatment Outcome
14.
Technol Cancer Res Treat ; 9(1): 53-60, 2010 Feb.
Article En | MEDLINE | ID: mdl-20082530

There are many motivations for adding simultaneously acquired MR images to PET scanning. The most straight forward are, superior registration of MR and PET images, the addition of morphological detail when there is non-rigid motion and for pre-clinical studies simultaneous imaging could lead to a significant reduction in the time that animals are required to be anesthetised. In addition simultaneous MR has the potential to provide accurate motion correction for PET image reconstruction. For functional imaging simultaneous acquisition is required to assess the subject in the same physiological state, such as acute stroke studies. The elimination of the additional radiation associated with combining CT with PET, by providing anatomic detail with MR, would be a crucial advantage for cancer screening. Combining the two instruments necessitates some engineering tradeoffs, especially associated with the use of the highly developed photomultiplier tube (PMT) used for light amplification, because of its incompatibility with strong magnetic fields. Our approach is to provide a split in the magnet and gradients to locate the magnetic sensitive components, the PMTs, in regions of low magnetic field, leaving only the essential PET components, the scintillator blocks, in the strong magnetic field region. The crystals are coupled to the PMTs by extending the optical fibres. A further advantage accrues by moving the PET electronics out of the region seen by the MR radio-frequency (RF) and gradient coils as electromagnetic interference effects between the PET and MR systems, which could cause artefacts in either modality, are eliminated. Here we describe a preliminary evaluation of the system, which is essentially a microPET Focus-120 located in a 1T split magnet, and compare its performance to previous microPET instruments.


Magnetic Resonance Imaging/methods , Positron-Emission Tomography/methods , Animals , Apolipoproteins E/physiology , Electromagnetic Fields , Fluorodeoxyglucose F18 , Magnetic Resonance Imaging/instrumentation , Mice , Mice, Knockout , Positron-Emission Tomography/instrumentation , Radiopharmaceuticals , Whole Body Imaging
15.
J Comp Neurol ; 517(4): 524-38, 2009 Dec 01.
Article En | MEDLINE | ID: mdl-19795496

Somatostatin 28 immunoreactivity (Sst28-ir) identifies a specific subset of mossy fiber terminals in the adult mouse cerebellum. By using double-labeling immunohistochemistry, we determined that Sst28-ir is associated with presynaptic mossy fiber terminal rosettes, and not Purkinje cells, Golgi cells, or unipolar brush cells. Sst28-ir mossy fibers are restricted to the central zone (lobules VI/VII) and nodular zone (lobules IX, X) of the vermis, and the paraflocculus and flocculus. Within each transverse zone the mossy fiber terminal fields form a reproducible array of parasagittal stripes. The boundaries of Sst28-ir stripes align with a specific array of Purkinje cell stripes revealed by using immunocytochemistry for the small heat shock protein HSP25. In the cerebellum of the homozygous weaver mouse, in which a subpopulation of HSP25-ir Purkinje cells are located ectopically, the corresponding Sst28-ir mossy fiber projection is also ectopic, suggesting a role for a specific Purkinje cell subset in afferent pattern formation. Likewise, in the scrambler mutant mouse, Sst28-ir mossy fibers show a very close association with HSP25-ir Purkinje cell clusters. HSP25 itself does not appear to be critical for normal patterning, however: in the KJR mouse, which does not express cerebellar HSP25, Sst28 expression appears to be normal. Likewise, the Purkinje cell patterning antigens zebrin II and HSP25 are expressed normally in both Sst- and Sst-receptor knockout mice, suggesting that somatostatinergic transmission is not necessary for Purkinje cell stripe formation.


Cerebellum/cytology , Heat-Shock Proteins/metabolism , Neoplasm Proteins/metabolism , Nerve Fibers/metabolism , Purkinje Cells/metabolism , Somatostatin-28/metabolism , Animals , CD57 Antigens/metabolism , Choline O-Acetyltransferase/metabolism , Corticotropin-Releasing Hormone/metabolism , Gene Expression Regulation/genetics , Mice , Mice, Knockout , Mice, Neurologic Mutants/metabolism , Molecular Chaperones , Nerve Tissue Proteins/metabolism , Purkinje Cells/cytology , Receptors, Somatostatin/deficiency , Somatostatin-28/genetics , gamma-Aminobutyric Acid/metabolism
16.
Neuroscience ; 164(4): 1496-508, 2009 Dec 29.
Article En | MEDLINE | ID: mdl-19800947

Cerebellar unipolar brush cells (UBCs) are glutamatergic interneurons of the granular layer. Previous studies have identified three distinct UBC subsets in the mouse cerebellar cortex: one expressing the calcium-binding protein calretinin (CR), a second expressing both the metabotropic glutamate receptor (mGluR)1alpha and phospholipase C(PLC)beta4, and a third expressing PLCbeta4 but not mGluR1alpha. We have investigated UBC topography in two strains of mutant mice: early B-cell factor 2 (Ebf2) null and scrambler. In Ebf2 null mice Purkinje cell topography is disrupted due to Purkinje cell death and ectopic gene expression. The topography of all three classes of UBCs is also abnormal: the CR(+) UBCs, which are normally aligned with zebrin II stripes, become homogeneously distributed; the numerical density of mGluRlalpha(+) UBCs is increased; and many PLCbeta4(+) UBCs are located ectopically. The UBC ectopia is not a cell-intrinsic action of the Ebf2 gene-analysis of the constitutive expression of a beta-galactoside reporter under the control of the Ebf2 promoter reveals no Ebf2 expression in UBCs at any stage of cerebellar development. In scrambler (Dab1(scm)), most Purkinje cells are ectopic but nevertheless have normal adult gene expression patterns. In scrambler, UBCs associate with specific ectopic Purkinje cell clusters. Finally, similar associations with specific Purkinje cell clusters are seen during normal cerebellar development. These data suggest that UBCs become regionally restricted during development through a non-cell-autonomous mechanism involving embryonic interactions with different Purkinje cell subtypes.


Cerebellum/cytology , Interneurons/cytology , Purkinje Cells/cytology , Animals , Basic Helix-Loop-Helix Transcription Factors/genetics , Calbindin 2 , Cell Death , Cell Polarity , Cerebellum/embryology , Cerebellum/metabolism , Mice , Mice, Knockout , Nerve Tissue Proteins/genetics , Nerve Tissue Proteins/metabolism , Purkinje Cells/metabolism , Receptors, Metabotropic Glutamate/metabolism , S100 Calcium Binding Protein G/metabolism
17.
Neuroscience ; 161(1): 123-38, 2009 Jun 16.
Article En | MEDLINE | ID: mdl-19306913

The cerebellar nuclei integrate inhibitory input from Purkinje cells with excitatory input from mossy and climbing fiber collaterals and are the sole cerebellar output. Numerous studies have shown that the cerebellar cortex is highly compartmentalized into hundreds of genetically determined, reproducible topographic units--transverse zones and parasagittal stripes--that can be identified through the expression patterns of numerous molecules. The Purkinje cell stripes project to the cerebellar nuclei. However, there is no known commensurate topographic complexity in the cerebellar nuclei. Rather, conventional anatomical descriptions identify four major subdivisions--the medial, anterior and posterior interposed, and lateral nuclei--together with a few intranuclear subdivisions. To begin to address the apparent complexity gap, we have used a panel of antigens and transgenes to reveal a reproducible molecular heterogeneity in the mouse cerebellar nuclei. Based on the differential expression patterns, singly and in combination, a new cerebellar nuclear topographic map has been constructed. This reveals the subdivision of the cerebellar nuclei into at least 12 reproducible expression domains. We hypothesize that such heterogeneity is the counterpart of the zones and stripes of the cerebellar cortex.


Cerebellar Nuclei/anatomy & histology , Animals , Basic Helix-Loop-Helix Transcription Factors/biosynthesis , Basic Helix-Loop-Helix Transcription Factors/genetics , CD57 Antigens/biosynthesis , Cerebellar Nuclei/metabolism , Fructose-Bisphosphate Aldolase/biosynthesis , Gene Expression , Glycine Plasma Membrane Transport Proteins/biosynthesis , Glycine Plasma Membrane Transport Proteins/genetics , Green Fluorescent Proteins/genetics , Immunohistochemistry , Lac Operon , Mice , Mice, Transgenic , Nerve Tissue Proteins/biosynthesis , Phospholipase C beta/biosynthesis , Protein Serine-Threonine Kinases/biosynthesis , Transgenes
18.
Neuroscience ; 153(4): 1190-201, 2008 Jun 02.
Article En | MEDLINE | ID: mdl-18455884

The mammalian cerebellum is composed of a highly reproducible array of transverse zones, each of which is subdivided into parasagittal stripes. By using a combination of Purkinje cell antigenic markers and afferent tracing, four transverse zones have been identified: the anterior zone (AZ: approximately lobules I-V), the central zone (CZ: approximately lobules VI-VII), the posterior zone (PZ: approximately lobules VIII-dorsal IX) and the nodular zone (NZ: approximately ventral lobule IX+lobule X). Neurofilament-associated antigen (NAA) is an epitope recognized by a monoclonal antibody, which is expressed strongly in association with neurofilaments. During perinatal cerebellar development, anti-NAA immunocytochemistry reveals novel features of cerebellar organization. In particular, the CZ is reproducibly subdivided into anterior and posterior components. Between embryonic day 17 and postnatal day 7 NAA immunoreactivity is expressed selectively by a parallel fiber bundle that is restricted to lobule VII, thereby distinguishing the CZ anterior (lobules VIa, b) from the CZ posterior (lobule VII). The novel restriction boundary at lobule VII/VIII, which is also reflected in the morphology of the external granular layer and aligns with a gap in the developing Purkinje cell layer, precedes the morphological appearance of the posterior superior fissure between lobules VIb and VII. In addition, afferent axons to the CZ terminate in an array of parasagittal stripes that is probably a specific climbing fiber projection. Thus, the transverse zone architecture of the mouse cerebellum is more complex than had previously been appreciated.


Cerebellum/anatomy & histology , Gene Expression Regulation, Developmental/physiology , Nerve Tissue Proteins/metabolism , Neurofilament Proteins/metabolism , Animals , Animals, Newborn , Body Patterning/physiology , Calbindins , Cerebellum/embryology , Cerebellum/growth & development , Embryo, Mammalian , Epitopes/genetics , Epitopes/metabolism , Eye Proteins/metabolism , Homeodomain Proteins/metabolism , Luminescent Proteins/genetics , Luminescent Proteins/metabolism , Mice , Mice, Inbred C57BL , Mice, Transgenic , Nerve Tissue Proteins/genetics , Neuropeptides/metabolism , PAX6 Transcription Factor , Paired Box Transcription Factors/metabolism , Purkinje Cells/metabolism , Repressor Proteins/metabolism , S100 Calcium Binding Protein G/metabolism
19.
Neuroscience ; 153(3): 721-32, 2008 May 15.
Article En | MEDLINE | ID: mdl-18403128

The mammalian cerebellar cortex is highly compartmentalized. First, it is subdivided into four transverse expression domains: the anterior zone (AZ), the central zone (CZ), the posterior zone (PZ), and the nodular zone (NZ). Within each zone, the cortex is further subdivided into a symmetrical array of parasagittal stripes. The most extensively studied compartmentation antigen is zebrin II/aldolase c, which is expressed by a subset of Purkinje cells forming parasagittal stripes. Stripe phenotypes are specified early in cerebellar development, in part through the action of early B-cell factor 2 (Ebf2), a member of the atypical helix-loop-helix transcription factor family Collier/Olf1/EBF. In the murine cerebellum, Ebf2 expression is restricted to the zebrin II-immunonegative (zebrin II-) Purkinje cell population. We have identified multiple cerebellar defects in the Ebf2 null mouse involving a combination of selective Purkinje cell death and ectopic expression of multiple genes normally restricted to the zebrin II- subset. The nature of the cerebellar defect in the Ebf2 null is different in each transverse zone. In contrast to the ectopic expression of genes characteristic of the zebrin II+ Purkinje cell phenotype, phospholipase Cbeta4 expression, restricted to zebrin II- Purkinje cells in control mice, is well maintained, and the normal number of stripes is present. Taken together, these data suggest that Ebf2 regulates the expression of genes associated with the zebrin II+ Purkinje cell phenotype and that the zebrin II- Purkinje cell subtype is specified independently.


Basic Helix-Loop-Helix Transcription Factors/metabolism , Cerebellum/cytology , Cerebellum/metabolism , Nerve Tissue Proteins/metabolism , Purkinje Cells/metabolism , Animals , Gene Expression , Gene Expression Regulation , Immunohistochemistry , Mice , Mice, Knockout , Phenotype , Purkinje Cells/cytology
20.
Neuroscience ; 150(4): 863-79, 2007 Dec 19.
Article En | MEDLINE | ID: mdl-18031938

Subventricular zone (SVZ)-derived adult neurospheres express two ectonucleotidases, nucleoside triphosphate diphosphohydrolase 2 (NTPDase2) and tissue non-specific alkaline phosphatase (TNAP). Agonists of the nucleotide receptors P2Y(1) and P2Y(2) as well as adenosine augment growth factor-mediated progenitor cell proliferation. NTPDase2 converts ATP and UTP to ADP and UDP, respectively, which are all P2Y receptor agonists. TNAP hydrolyzes nucleoside triphosphates and diphosphates and produces the P1 receptor agonist adenosine. In the SVZ, NTPDase2 is specifically expressed by type B cells. In order to further scrutinize the association of key molecules of the purinergic signaling pathway with neurogenic regions, we analyzed the expression of TNAP at the lateral ventricles of the adult and developing mouse brain. In the adult brain, TNAP was expressed by type B, type A and at least subsets of type C cells of the SVZ and throughout the rostral migratory stream. Almost 100% of the proliferating, Ki-67-positive cells of the adult SVZ stained for TNAP, supporting the notion of a ubiquitous association of TNAP with SVZ progenitors. In contrast, NTPDase2-positive progenitors of the dentate gyrus were TNAP-negative. Essentially all cells of the telencephalic vesicle at embryonic day (E) 14 revealed TNAP activity, including doublecortin-positive neuroblasts. During further embryonic development, enhanced TNAP activity became restricted to cells of the ventricular and SVZ. In contrast to TNAP, NTPDase2 was first expressed in the SVZ perinatally, in association with TNAP-positive SVZ border cells. During later development, NTPDase2-positive cells disappeared from the ventricular surface and began to form sheaths around clusters of subventricular doublecortin-positive cells, apparently transforming into type B cells. Our results identify TNAP and NTPDase2 as novel markers for subsets of progenitors in the adult and developing mouse brain. They further support the notion that signaling via extracellular nucleotides and nucleosides contributes to embryonic and adult neurogenesis.


Adenosine Triphosphatases/metabolism , Cell Differentiation/physiology , Cell Proliferation , Lateral Ventricles/cytology , Nucleoside-Triphosphatase/metabolism , Stem Cells/physiology , Alkaline Phosphatase/metabolism , Animals , Animals, Newborn , Brain/cytology , Brain/embryology , Brain/growth & development , Doublecortin Domain Proteins , Embryo, Mammalian , Excitatory Amino Acid Transporter 1 , Female , Gene Expression Regulation, Developmental , Ki-67 Antigen/metabolism , Lateral Ventricles/embryology , Lateral Ventricles/growth & development , Mice , Microtubule-Associated Proteins/metabolism , Nerve Tissue Proteins/metabolism , Neuropeptides/metabolism , Pregnancy
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