direct-imaging-er-calcium-with-targeted-esterase-induced-dye-loading

Direct Imaging of ER Calcium with Targeted-Esterase Induced Dye Loading (TED)

Visualization of calcium dynamics is important to understand the role of calcium in cell physiology. To examine calcium dynamics, synthetic fluorescent ...

Lacrimal-auricular-dental-digital (LADD) syndrome comprises multiple anomalies. It can be inherited as autosomal dominant with variable expressivity or can be sporadic in nature. The clinical features of LADD syndrome include variably, lacrimal system hypoplasia, ear anomalies (with or without hearing impairment), salivary system hypoplasia, epiblepharon, dry eyes, corneal limbal stem cells deficiency, hypodontia, microdontia, xerostomia, and clinodactyly. We would like to report a unique case series of LADD syndrome patients presenting with diffuse ophthalmoplegia and facial muscle dysfunction, which may be a distinct subset of LADD syndrome or a new syndrome itself. We believe this to be the first such report. We suggest careful examination of ocular movements in all newly diagnosed LADD syndrome patients.

Lacrimal-auricular-dental-digital (LADD) syndrome with diffuse ophthalmoplegia--a new finding.

Stress and the brain: how experiences and exposures across the life span shape health, development, and learning in adolescence.

In mammalian cells, signal peptide-dependent protein transport into the endoplasmic reticulum (ER) is mediated by a dynamic protein-conducting channel, the Sec61 complex. Previous work has characterized the Sec61 channel as a potential ER Ca(2+) leak channel and identified calmodulin as limiting Ca(2+) leakage in a Ca(2+)-dependent manner by binding to an IQ motif in the cytosolic aminoterminus of Sec61Î±. Here, we manipulated the concentration of the ER lumenal chaperone BiP in cells in different ways and used live cell Ca(2+) imaging to monitor the effects of reduced levels of BiP on ER Ca(2+) leakage. Regardless of how the BiP concentration was lowered, the absence of available BiP led to increased Ca(2+) leakage via the Sec61 complex. When we replaced wild-type Sec61Î± with mutant Sec61Î±Y344H in the same model cell, however, Ca(2+) leakage from the ER increased and was no longer affected by manipulation of the BiP concentration. Thus, BiP limits ER Ca(2+) leakage through the Sec61 complex by binding to the ER lumenal loop 7 of Sec61Î± in the vicinity of tyrosine 344.

BiP-mediated closing of the Sec61 channel limits Ca2+ leakage from the ER.

Reduced levels of the SMN (survival of motoneuron) protein cause spinal muscular atrophy, the main form of motoneuron disease in children and young adults. In cultured motoneurons, reduced SMN levels lead to disturbed axon growth that correlates with reduced actin mRNA and protein in growth cones, indicating that anterograde transport and local translation of Î²-actin mRNA are altered in this disease. However, it is not fully understood how local translation of the Î²-actin mRNA is regulated in SMN-deficient motoneurons. Here, we established a lentiviral GFP-based reporter construct to monitor local translation of Î²-actin mRNA. Time-lapse imaging of fluorescence recovery after photobleaching (FRAP) in living motoneurons revealed that Î²-actin is locally translated in the growth cones of embryonic motoneurons. Interestingly, local translation of the Î²-actin reporter construct was differentially regulated by various Laminin isoforms, indicating that Laminins provide extracellular cues for the regulation of local translation in growth cones. Notably, local translation of Î²-actin mRNA was deregulated in motoneurons from a mouse model for the most severe form of SMA (Smn(-/-);SMN2). Taken together our findings suggest that local translation of Î²-actin in growth cones of motoneurons is regulated by Laminin signalling and that this signalling is disturbed in SMA.

Laminin induced local axonal translation of Î²-actin mRNA is impaired in SMN-deficient motoneurons.

Bronfenbrenner's ecological systems theory, a multisystem framework, was used to identify risk and protective factors associated with adolescent mental and physical health (AMPH) in the English-speaking Caribbean.

Adolescent mental and physical health in the English-speaking Caribbean.

China's rates of internal migration increased to an all-time high of over 200 million individuals at the beginning of the twenty-first century. Yet, there is a dearth of information on the lives of young migrant populations. The aim of this study was to explore how migration influences the sexual attitudes and behaviours of 18-24-year-old migrant men and women in Shanghai, China. A total of 64 migrants participated in 10 focus-group discussions and 20 in-depth interviews. Guided by acculturation theory, coded data were organised into analytic matrices to compare themes across participants. Factors associated with increased sexual-risk behaviours include acculturative stress, discrimination leading to social isolation, conflicts between traditional and modern city values and increased sexual opportunities. Premarital sex, cohabitation, unprotected sex and visiting sex workers are common among this population. Reasons for not using condoms included being unprepared, lack of knowledge and barriers in accessing reproductive services due to not having urban documentation. Local family planning programmes should help migrants negotiate traditional and modern values and partner with work-sites to provide comprehensive sexual education and services and train health professionals in the specific healthcare needs of young migrant populations.

Sexual attitudes, behaviours and acculturation among young migrants in Shanghai.

Spontaneous electrical activity preceding synapse formation contributes to the precise regulation of neuronal development. Examining the origins of spontaneous activity revealed roles for neurotransmitters that depolarize neurons and activate ion channels. Recently, we identified a new molecular mechanism underlying fluctuations in spontaneous neuronal excitability. We found that embryonic motoneurons with a genetic loss of the low-threshold sodium channel NaV1.9 show fewer fluctuations in intracellular calcium in axonal compartments and growth cones than wild-type littermates. As a consequence, axon growth of NaV1.9-deficient motoneurons in cell culture is drastically reduced while dendritic growth and cell survival are not affected. Interestingly, NaV1.9 function is observed under conditions that would hardly allow a ligand- or neurotransmitter-dependent depolarization. Thus, NaV1.9 may serve as a cell-autonomous trigger for neuronal excitation. In this addendum, we discuss a model for the interplay between cell-autonomous local neuronal activity and local cytoskeleton dynamics in growth cone function.

Cell-autonomous axon growth of young motoneurons is triggered by a voltage-gated sodium channel.

Based on previous data, road traffic injury (RTI) was a leading cause of non-fatal injury in all-age groups in Vietnam, and among the top causes of injury in children and adolescents. Specific analysis on RTIs in young people, however, has yet to be fully investigated. Using the results of two surveys in 2004 and 2009, the present study aims to describe the current situation of non-fatal, unintentional RTIs among Vietnamese youths. In addition, it explores RTI-related risk and protective factors.

Road traffic injury among young people in Vietnam: evidence from two rounds of national adolescent health surveys, 2004-2009.

This study focuses on the role of the kinase BRaf in postnatal brain development. Mice expressing truncated, non-functional BRaf in neural stem cell-derived brain tissue demonstrate alterations in the cerebellum, with decreased sizes and fuzzy borders of the glomeruli in the granule cell layer. In addition we observed reduced numbers and misplaced ectopic Purkinje cells that showed an altered structure of their dendritic arborizations in the hippocampus, while the overall cornus ammonis architecture appeared to be unchanged. In male mice lacking BRaf in the hippocampus the size of the granule cell layer was normal at postnatal day 12 (P12) but diminished at P21, as compared to control littermates. This defect was caused by a reduced ability of dentate gyrus progenitor cells to differentiate into NeuN positive granule cell neurons. In vitro cell culture of P0/P1 hippocampal cells revealed that BRaf deficient cells were impaired in their ability to form microtubule-associated protein 2 positive neurons. Together with the alterations in behaviour, such as autoaggression and loss of balance fitness, these observations indicate that in the absence of BRaf all neuronal cellular structures develop, but neuronal circuits in the cerebellum and hippocampus are partially disturbed besides impaired neuronal generation in both structures.

Ablation of BRaf impairs neuronal differentiation in the postnatal hippocampus and cerebellum.

The aim of this analysis was to evaluate a new visual scoring scale developed to facilitate the qualitative appraisal of lesion uptake on F-fluorothymidine PET (F-FLT-PET).

Evaluation of a new visual uptake scoring scale for 18F-fluorothymidine positron emission tomography in the diagnosis of pulmonary lesions.

PURPOSE:: To evaluate microperimetry changes in patients with acute macular edema secondary to branch retinal vein occlusion during a follow-up period of 12 months with intravitreal ranibizumab treatment (Lucentis; Novartis). METHODS:: Patients with macular edema secondary to branch retinal vein occlusion received an intravitreous injection of 0.5 mg of ranibizumab (0.05 mL). Best-corrected visual acuity, Spectralis OCT (Heidelberg Engineering), and color fundus photography were performed at monthly intervals over a follow-up period of 1 year. Macular function was documented by microperimetry (Nidek, MP-1) at baseline, 3, and 12 months. RESULTS:: Data of 20 patients without lack of microperimetry results were included to the statistical analyses. The size of the area of absolute scotoma was reduced from 16% at baseline to 11.7% at Month 3 and remained stable in the entire study duration (P > 0.05). Mean differential light threshold improved significantly under therapy from 9.47 dB at baseline to 12.53 dB at 12 months (P < 0.001). Best-corrected visual acuity correlated significantly with central millimeter thickness and mean retinal sensitivity at baseline and at 12-month follow-up visits. CONCLUSION:: In addition to anatomical restoration and increased visual acuity, intravitreal ranibizumab also improved the central macular function in patients with acute macular edema after branch retinal vein occlusion.

RESPONSE OF RETINAL SENSITIVITY TO RANIBIZUMAB TREATMENT OF MACULAR EDEMA AFTER ACUTE BRANCH RETINAL VEIN OCCLUSION.

Evolution of the mammalian brain encompassed a remarkable increase in size of the cerebral cortex, which includes tangential and radial expansion. However, the mechanisms underlying these key features are still largely unknown. Here, we identified the DNA-associated protein Trnp1 as a regulator of cerebral cortex expansion in both of these dimensions. Gain- and loss-of-function experiments in the mouse cerebral cortex inÂ vivo demonstrate that high Trnp1 levels promote neural stem cell self-renewal and tangential expansion. In contrast, lower levels promote radial expansion, with a potent increase of the number of intermediate progenitors and basal radial glial cells leading to folding of the otherwise smooth murine cerebral cortex. Remarkably, TRNP1 expression levels exhibit regional differences in the cerebral cortex of human fetuses, anticipating radial or tangential expansion. Thus, the dynamic regulation of Trnp1 is critical to control tangential and radial expansion of the cerebral cortex in mammals.

Article	Year
Lacrimal-auricular-dental-digital (LADD) syndrome with diffuse ophthalmoplegia--a new finding. Seminars in ophthalmology\| PubMed ID: 22784266	2012
Stress and the brain: how experiences and exposures across the life span shape health, development, and learning in adolescence. The Journal of adolescent health : official publication of the Society for Adolescent Medicine\| PubMed ID: 22794527	2012
BiP-mediated closing of the Sec61 channel limits Ca2+ leakage from the ER. The EMBO journal\| PubMed ID: 22796945	2012
Laminin induced local axonal translation of Î²-actin mRNA is impaired in SMN-deficient motoneurons. Histochemistry and cell biology\| PubMed ID: 22810847	2012
Adolescent mental and physical health in the English-speaking Caribbean. Revista panamericana de salud pÃºblica = Pan American journal of public health\| PubMed ID: 22910727	2012
Sexual attitudes, behaviours and acculturation among young migrants in Shanghai. Culture, health & sexuality\| PubMed ID: 22943505	2012
Cell-autonomous axon growth of young motoneurons is triggered by a voltage-gated sodium channel. Channels (Austin, Tex.)\| PubMed ID: 23238424	2013
Road traffic injury among young people in Vietnam: evidence from two rounds of national adolescent health surveys, 2004-2009. Global health action\| PubMed ID: 23336620	2013
Ablation of BRaf impairs neuronal differentiation in the postnatal hippocampus and cerebellum. PloS one\| PubMed ID: 23505473	2013
Evaluation of a new visual uptake scoring scale for 18F-fluorothymidine positron emission tomography in the diagnosis of pulmonary lesions. Nuclear medicine communications\| PubMed ID: 23542911	2013
RESPONSE OF RETINAL SENSITIVITY TO RANIBIZUMAB TREATMENT OF MACULAR EDEMA AFTER ACUTE BRANCH RETINAL VEIN OCCLUSION. Retina (Philadelphia, Pa.)\| PubMed ID: 23584689	2013
Trnp1 regulates expansion and folding of the Mammalian cerebral cortex by control of radial glial fate. Cell\| PubMed ID: 23622239	2013

Robert Blum

Biography

JoVE Journal Publications

Other Publications