THE ROLE OF NADPH OXIDASE IN NEURITE OUTGROWTH AND ZEBRAFISH NEURODEVELOPMENT

Nicotinamide adenine dinucleotide phosphate oxidases (NOX) are a family of enzymes that produce reactive oxygen species (ROS). The first NOX enzyme was discovered in leukocytes and associated with host defense in the immune system. Subsequent findings of ROS production in non-immune cells led to the identification of six additional NOX isoforms, and opened new avenues for research into NOX-mediated cellular functions. Since then, NOX-derived ROS have been found to be involved in a tremendous number of cell signaling pathways. Of particular interest is the well-established function of NOX-derived ROS in signaling pathways that drive cytoskeletal rearrangements and motility in several cell types. Our lab is interested in the highly motile neuronal growth cone that guides axonal growth during neurodevelopment and regeneration. Others have reported that inhibition of NOX enzymes during development causes a decrease in the size of some brain areas, and NOX deficiencies in humans are correlated with diminished cognitive function. Despite the fact that NOX activity is necessary for some cell motility in non-neuronal cells and a loss of NOX function during development has impacts on brain structure, it is still unclear what role NOX plays in axonal growth and guidance or the establishment of connections in the central nervous system

Off-Label Use of Transmucosal Ketamine as a Rapidacting Antidepressant: A Retrospective Chart Review

Objective: This study evaluated the effectiveness and safety of subanesthetic doses of ketamine using an off-label, transmucosal administration route in patients with treatment-resistant depression. Methods: A retrospective chart review was conducted to identify patients who met the inclusion criteria for treatment-resistant major depressive disorder. Seventeen such patients who received subanesthetic doses of ketamine were included. Patient demographics, efficacy (drug refill, clinician notes), side effects, and concurrent medications were assessed. Results: Benefit from low-dose transmucosal ketamine was noted in 76% of subjects (average age 48 years, 88% female), with a dose duration lasting 7–14 days. No notable side effects were noted. The most common classes of concurrent medications to which ketamine was added were serotonin–norepinephrine reuptake inhibitors (59%), stimulants (47%), folate replacement (47%), and benzodiazepines (47%). Conclusion: Our results provide preliminary evidence of the effectiveness and safety of lowdose transmucosal ketamine in treatment-resistant patients. A controlled, prospective pilot study is warranted to validate these findings

Anisotropy vs Isotropy in Living Cell Indentation With AFM

The measurement of local mechanical properties of living cells by nano/micro indentation relies on the foundational assumption of locally isotropic cellular deformation. As a consequence of assumed isotropy, the cell membrane and underlying cytoskeleton are expected to locally deform axisymmetrically when indented by a spherical tip. Here, we directly observe the local geometry of deformation of membrane and cytoskeleton of different living adherent cells during nanoindentation with the integrated Atomic Force (AFM) and spinning disk confocal (SDC) microscope. We show that the presence of the perinuclear actin cap (apical stress fibers), such as those encountered in cells subject to physiological forces, causes a strongly non-axisymmetric membrane deformation during indentation reflecting local mechanical anisotropy. In contrast, axisymmetric membrane deformation reflecting mechanical isotropy was found in cells without actin cap: cancerous cells MDA-MB-231, which naturally lack the actin cap, and NIH 3T3 cells in which the actin cap is disrupted by latrunculin A. Careful studies were undertaken to quantify the effect of the live cell fluorescent stains on the measured mechanical properties. Using finite element computations and the numerical analysis, we explored the capability of one of the simplest anisotropic models – transverse isotropy model with three local mechanical parameters (longitudinal and transverse modulus and planar shear modulus) – to capture the observed non-axisymmetric deformation. These results help identifying which cell types are likely to exhibit non-isotropic properties, how to measure and quantify cellular deformation during AFM indentation using live cell stains and SDC, and suggest modelling guidelines to recover quantitative estimates of the mechanical properties of living cells

Multilevel Analysis in Rural Cancer Control: A Conceptual Framework and Methodological Implications

Mitochondria are abundantly detected at the growth cone, the dynamic distal tip of developing axons that directs growth and guidance. It is, however, poorly understood how mitochondrial dynamics relate to growth cone behavior in vivo, and which mechanisms are responsible for anchoring mitochondria at the growth cone during axon pathfinding. Here, we show that in retinal axons elongating along the optic tract in zebrafish, mitochondria accumulate in the central area of the growth cone and are occasionally observed in filopodia extending from the growth cone periphery. Mitochondrial behavior at the growth cone in vivo is dynamic, with mitochondrial positioning and anterograde transport strongly correlating with growth cone behavior and axon outgrowth. Using novel zebrafish mutant lines that lack the mitochondrial anchoring proteins Syntaphilin a and b, we further show that Syntaphilins contribute to mitochondrial immobilization at the growth cone. Syntaphilins are, however, not required for proper growth cone morphology and axon growth in vivo, indicating that Syntaphilin-mediated anchoring of mitochondria at the growth cone plays only a minor role in elongating axons

BCMA Is Essential for the Survival of Long-lived Bone Marrow Plasma Cells

Long-lived humoral immunity is manifested by the ability of bone marrow plasma cells (PCs) to survive for extended periods of time. Recent studies have underscored the importance of BLyS and APRIL as factors that can support the survival of B lineage lymphocytes. We show that BLyS can sustain PC survival in vitro, and this survival can be further enhanced by interleukin 6. Selective up-regulation of Mcl-1 in PCs by BLyS suggests that this α-apoptotic gene product may play an important role in PC survival. Blockade of BLyS, via transmembrane activator and cyclophilin ligand interactor–immunoglobulin treatment, inhibited PC survival in vitro and in vivo. Heightened expression of B cell maturation antigen (BCMA), and lowered expression of transmembrane activator and cyclophilin ligand interactor and BAFF receptor in PCs relative to resting B cells suggests a vital role of BCMA in PC survival. Affirmation of the importance of BCMA in PC survival was provided by studies in BCMA−/− mice in which the survival of long-lived bone marrow PCs was impaired compared with wild-type controls. These findings offer new insights into the molecular basis for the long-term survival of PCs

Global burden and strength of evidence for 88 risk factors in 204 countries and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

Background: Understanding the health consequences associated with exposure to risk factors is necessary to inform public health policy and practice. To systematically quantify the contributions of risk factor exposures to specific health outcomes, the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 aims to provide comprehensive estimates of exposure levels, relative health risks, and attributable burden of disease for 88 risk factors in 204 countries and territories and 811 subnational locations, from 1990 to 2021. Methods: The GBD 2021 risk factor analysis used data from 54 561 total distinct sources to produce epidemiological estimates for 88 risk factors and their associated health outcomes for a total of 631 risk–outcome pairs. Pairs were included on the basis of data-driven determination of a risk–outcome association. Age-sex-location-year-specific estimates were generated at global, regional, and national levels. Our approach followed the comparative risk assessment framework predicated on a causal web of hierarchically organised, potentially combinative, modifiable risks. Relative risks (RRs) of a given outcome occurring as a function of risk factor exposure were estimated separately for each risk–outcome pair, and summary exposure values (SEVs), representing risk-weighted exposure prevalence, and theoretical minimum risk exposure levels (TMRELs) were estimated for each risk factor. These estimates were used to calculate the population attributable fraction (PAF; ie, the proportional change in health risk that would occur if exposure to a risk factor were reduced to the TMREL). The product of PAFs and disease burden associated with a given outcome, measured in disability-adjusted life-years (DALYs), yielded measures of attributable burden (ie, the proportion of total disease burden attributable to a particular risk factor or combination of risk factors). Adjustments for mediation were applied to account for relationships involving risk factors that act indirectly on outcomes via intermediate risks. Attributable burden estimates were stratified by Socio-demographic Index (SDI) quintile and presented as counts, age-standardised rates, and rankings. To complement estimates of RR and attributable burden, newly developed burden of proof risk function (BPRF) methods were applied to yield supplementary, conservative interpretations of risk–outcome associations based on the consistency of underlying evidence, accounting for unexplained heterogeneity between input data from different studies. Estimates reported represent the mean value across 500 draws from the estimate's distribution, with 95% uncertainty intervals (UIs) calculated as the 2·5th and 97·5th percentile values across the draws. Findings: Among the specific risk factors analysed for this study, particulate matter air pollution was the leading contributor to the global disease burden in 2021, contributing 8·0% (95% UI 6·7–9·4) of total DALYs, followed by high systolic blood pressure (SBP; 7·8% [6·4–9·2]), smoking (5·7% [4·7–6·8]), low birthweight and short gestation (5·6% [4·8–6·3]), and high fasting plasma glucose (FPG; 5·4% [4·8–6·0]). For younger demographics (ie, those aged 0–4 years and 5–14 years), risks such as low birthweight and short gestation and unsafe water, sanitation, and handwashing (WaSH) were among the leading risk factors, while for older age groups, metabolic risks such as high SBP, high body-mass index (BMI), high FPG, and high LDL cholesterol had a greater impact. From 2000 to 2021, there was an observable shift in global health challenges, marked by a decline in the number of all-age DALYs broadly attributable to behavioural risks (decrease of 20·7% [13·9–27·7]) and environmental and occupational risks (decrease of 22·0% [15·5–28·8]), coupled with a 49·4% (42·3–56·9) increase in DALYs attributable to metabolic risks, all reflecting ageing populations and changing lifestyles on a global scale. Age-standardised global DALY rates attributable to high BMI and high FPG rose considerably (15·7% [9·9–21·7] for high BMI and 7·9% [3·3–12·9] for high FPG) over this period, with exposure to these risks increasing annually at rates of 1·8% (1·6–1·9) for high BMI and 1·3% (1·1–1·5) for high FPG. By contrast, the global risk-attributable burden and exposure to many other risk factors declined, notably for risks such as child growth failure and unsafe water source, with age-standardised attributable DALYs decreasing by 71·5% (64·4–78·8) for child growth failure and 66·3% (60·2–72·0) for unsafe water source. We separated risk factors into three groups according to trajectory over time: those with a decreasing attributable burden, due largely to declining risk exposure (eg, diet high in trans-fat and household air pollution) but also to proportionally smaller child and youth populations (eg, child and maternal malnutrition); those for which the burden increased moderately in spite of declining risk exposure, due largely to population ageing (eg, smoking); and those for which the burden increased considerably due to both increasing risk exposure and population ageing (eg, ambient particulate matter air pollution, high BMI, high FPG, and high SBP). Interpretation: Substantial progress has been made in reducing the global disease burden attributable to a range of risk factors, particularly those related to maternal and child health, WaSH, and household air pollution. Maintaining efforts to minimise the impact of these risk factors, especially in low SDI locations, is necessary to sustain progress. Successes in moderating the smoking-related burden by reducing risk exposure highlight the need to advance policies that reduce exposure to other leading risk factors such as ambient particulate matter air pollution and high SBP. Troubling increases in high FPG, high BMI, and other risk factors related to obesity and metabolic syndrome indicate an urgent need to identify and implement interventions

Headline Hawai`i: Racial Aloha in Kama`aina News

The front page of Hawai`i\u27s largest-circulated newspaper - The Honolulu Star-Bulletin - was reviewed for a three-month period: March 1, 2008 - June 1, 2008, to examine representations of race in a media market where Caucasian individuals are the minority. Analysis of the newspaper seeks to present a greater understanding of ethnic portrayals in island news and examines ethical implications that have/can arise from adopting journalistic values typical of white news or mainstream reporting practices in areas where the mainstream is, in fact, the minority

The Role of NADPH Oxidases in Neurite Outgrowth and Zebrafish Neurodevelopment

Nicotinamide adenine dinucleotide phosphate oxidases (NOX) are a family of enzymes that produce reactive oxygen species (ROS). The first NOX enzyme was discovered in leukocytes and associated with host defense in the immune system. Subsequent findings of ROS production in non-immune cells led to the identification of six additional NOX isoforms, and opened new avenues for research into NOX-mediated cellular functions. Since then, NOX-derived ROS have been found to be involved in a tremendous number of cell signaling pathways. Of particular interest is the well-established function of NOX-derived ROS in signaling pathways that drive cytoskeletal rearrangements and motility in several cell types. Our lab is interested in the highly motile neuronal growth cone that guides axonal growth during neurodevelopment and regeneration. Others have reported that inhibition of NOX enzymes during development causes a decrease in the size of some brain areas, and NOX deficiencies in humans are correlated with diminished cognitive function. Despite the fact that NOX activity is necessary for some cell motility in non-neuronal cells and a loss of NOX function during development has impacts on brain structure, it is still unclear what role NOX plays in axonal growth and guidance or the establishment of connections in the central nervous system. In this series of studies, I investigated the function of NOX enzymes in neurite outgrowth and neurodevelopment using both in vitro and in vivo approaches. I report that NOX activity is necessary for the extension of neurites in culture. Inhibition NOX activity leads to a disorganization of the actin cytoskeleton, a decrease in retrograde flow and a loss of neurite outgrowth. Using embryonic zebrafish, I showed that four separate nox genes are expressed broadly throughout the central nervous system during the first two days of development. Functional studies in zebrafish revealed that NOX inhibition leads to expansion of the ganglion cell layer in the retina and decrease in the size of the optic nerve. Subsequent studies using a site-specific, RNA-guided mutagenesis approach (CRISPR/Cas9) showed that optic nerve thinning resulted from developmental delays while ganglion cell expansion was a permanent defect caused by the mutation of a specific NOX isoform, NOX2/CYBB. The targeting of optic nerve axons to the optic tectum of the midbrain was also disrupted in NOX2/CYBB mutants. These results show that NOX activity is critical for neurite outgrowth in cultured cells in addition to retinal development and axon targeting in vivo

Headline Hawai`i: Racial Aloha in Kama`aina News

The front page of Hawai`i\u27s largest-circulated newspaper - The Honolulu Star-Bulletin - was reviewed for a three-month period: March 1, 2008 - June 1, 2008, to examine representations of race in a media market where Caucasian individuals are the minority. Analysis of the newspaper seeks to present a greater understanding of ethnic portrayals in island news and examines ethical implications that have/can arise from adopting journalistic values typical of white news or mainstream reporting practices in areas where the mainstream is, in fact, the minority