Biomedical subjects

Wenyu Sun

Publications and source records attributed to Wenyu Sun.

10 recordsLinked to original sources

PubMed2006

Automated Neuropsychological Assessment Metrics sports medicine battery.

This paper describes the development and ongoing validation of the ANAM-sports medicine battery (ASMB) for use in concussion surveillance and management. A review of previous research utilizing the ASMB highlights current issues in concussion surveillance including: tracking cognitive recovery, effect of previous concussion history on acute concussion presentation, and clinical decision making using computerized measures. ASMB interpretation using reliable change indices or impairment indices is highlighted. Future development of the ASMB is discussed as it relates to interpretation of ASMB, development of appropriate norms, and defining adequate baseline assessment. This includes the definition of practice effects, the effects of maturation on test performance and definition of adequate baseline assessment that clearly defines a subject's normal cognitive performance level. ASMB is ready for cautious introduction into clinical practice for use by neuropsychologists with experience in both sports concussion and computerized testing.

Athletic Injuries↗

PubMed2006

Assessing change with the Automated Neuropsychological Assessment Metrics (ANAM): issues and challenges.

Accurately documenting cognitive change is important, as neuropsychologists are routinely asked to determine cognitive change following disease progression or medical intervention. Computerized testing batteries, such as the Automated Neuropsychological Assessment Metrics (ANAM), are good tools for assessing change, because they allow for randomization of stimuli, creating near limitless alternate forms and reducing practice effects. The question remains, however, as to how best to determine reliable change in performance using ANAM. The current study compared the use of Reliable Change Index (RCI) and regression based methods (REG) calculated from 28 individuals with migraine. These methods then were applied to an independent sample of 25 individuals with migraine assessed with ANAM at baseline, headache, and following pharmacologic treatment. Traditional repeated measures analyses revealed declines in cognitive efficiency following migraine onset on two of four ANAM tasks and significant improvement on all ANAM tasks following treatment. Rates of deterioration and improvement did not significantly differ between RCI and REG methods, although were slightly different across the ANAM tasks used in this study. A combined ANAM score categorized the most individuals as demonstrating cognitive change, revealing that 60% of subjects declined in performance following headache and 84% improved following migraine treatment.

Adult↗

PubMed2006

Retinol dehydrogenase (RDH12) protects photoreceptors from light-induced degeneration in mice.

RDH12 has been suggested to be one of the retinol dehydrogenases (RDH) involved in the vitamin A recycling system (visual cycle) in the eye. Loss of function mutations in the RDH12 gene were recently reported to be associated with autosomal recessive childhood-onset severe retinal dystrophy. Here we show that RDH12 localizes to the photoreceptor inner segments and that deletion of this gene in mice slows the kinetics of all-trans-retinal reduction, delaying dark adaptation. However, accelerated 11-cis-retinal production and increased susceptibility to light-induced photoreceptor apoptosis were also observed in Rdh12(-/-) mice, suggesting that RDH12 plays a unique, nonredundant role in the photoreceptor inner segments to regulate the flow of retinoids in the eye. Thus, severe visual impairments of individuals with null mutations in RDH12 may likely be caused by light damage(1).

Alcohol Oxidoreductases↗

PubMed2006

Autosomal recessive retinitis pigmentosa and E150K mutation in the opsin gene.

Retinitis pigmentosa (RP) is a heterogeneous group of hereditary disorders of the retina caused by mutation in genes of the photoreceptor proteins with an autosomal dominant (adRP), autosomal recessive (arRP), or X-linked pattern of inheritance. Although there are over 100 identified mutations in the opsin gene associated with RP, only a few of them are inherited with the arRP pattern. E150K is the first reported missense mutation associated with arRP. This opsin mutation is located in the second cytoplasmic loop of this G protein-coupled receptor. E150K opsin expressed in HEK293 cells and reconstituted with 11-cis-retinal displayed an absorption spectrum similar to the wild type (WT) counterpart and activated G protein transducin slightly faster than WT receptor. However, the majority of E150K opsin showed a higher apparent molecular mass in SDS-PAGE and was resistant to endoglycosidase H deglycosidase. Instead of being transported to the plasma membrane, E150K opsin is partially colocalized with the cis/medial Golgi compartment markers such as GM130 and Vti1b but not with the trans-Golgi network. In contrast to the endoplasmic reticulum-retained adRP mutant, P23H opsin, Golgi-retained E150K opsin did not influence the proper transport of the WT opsin when coexpressed in HEK293 cells. This result is consistent with the recessive pattern of inheritance of this mutation. Thus, our study reveals a novel molecular mechanism for retinal degeneration that results from deficient export of opsin from the Golgi apparatus.

Cell Line↗

PubMed2006

Is conception delay a risk factor for reduced gestation or birthweight?

Previous studies have suggested an association between delays in conception and adverse perinatal outcomes, specifically, low birthweight and preterm birth. We investigated the relationship between conception delay (defined as >6 months to become pregnant) and three perinatal outcomes: low birthweight (LBW; <2500 g), preterm birth (PTB; <37 weeks), and small-for-gestational-age (SGA; <10th percentile weight for given gestational age) using data from the Collaborative Perinatal Project. The study cohort was limited to pregnancies with a known time-to-pregnancy (n = 8465; 15%). Generalised estimating equations were used to estimate odds ratios (OR) and 95% confidence intervals [CI] for risk of adverse perinatal outcomes accounting for the clustering of pregnancy outcomes for women with more than one pregnancy. After adjusting for confounders, all ORs were close to the null (LBW, OR = 1.01; 95% CI = 0.86, 1.20), (PTB, OR = 1.10; 95% CI = 0.95, 1.27), (SGA, OR = 1.06; 95% CI = 0.91, 1.25). Thus, we found no evidence to support an adverse relationship between conception delay and decrements in gestation or birthweight among this select sample of fertile women, even after varying the cut-point for defining conception delay.

Adult↗

PubMed2005

Role of photoreceptor-specific retinol dehydrogenase in the retinoid cycle in vivo.

The retinoid cycle is a recycling system that replenishes the 11-cis-retinal chromophore of rhodopsin and cone pigments. Photoreceptor-specific retinol dehydrogenase (prRDH) catalyzes reduction of all-trans-retinal to all-trans-retinol and is thought to be a key enzyme in the retinoid cycle. We disrupted mouse prRDH (human gene symbol RDH8) gene expression by targeted recombination and generated a homozygous prRDH knock-out (prRDH-/-) mouse. Histological analysis and electron microscopy of retinas from 6- to 8-week-old prRDH-/- mice revealed no structural differences of the photoreceptors or inner retina. For brief light exposure, absence of prRDH did not affect the rate of 11-cis-retinal regeneration or the decay of Meta II, the activated form of rhodopsin. Absence of prRDH, however, caused significant accumulation of all-trans-retinal following exposure to bright lights and delayed recovery of rod function as measured by electroretinograms and single cell recordings. Retention of all-trans-retinal resulted in slight overproduction of A2E, a condensation product of all-trans-retinal and phosphatidylethanolamine. We conclude that prRDH is an enzyme that catalyzes reduction of all-trans-retinal in the rod outer segment, most noticeably at higher light intensities and prolonged illumination, but is not an essential enzyme of the retinoid cycle.

Alcohol Oxidoreductases↗

PubMed2004

Prevalence of and risk factors for depressive symptoms among young adolescents.

OBJECTIVE: To determine the prevalence, risk factors, and risk behaviors associated with depressive symptoms in a nationally representative, cross-sectional sample of young adolescents. DESIGN: A school-based survey collected through self-administered questionnaires in grades 6, 8, and 10 in 1996. SETTING: Schools in the United States. PARTICIPANTS: 9863 students in grades 6, 8, and 10 (average ages, 11, 13, and 15). MAIN OUTCOME MEASURES: Depressive symptoms, substance use, somatic symptoms, scholastic behaviors, and involvement in bullying. RESULTS: Eighteen percent of youths reported symptoms of depression. A higher proportion of females (25%) reported depressive symptoms than males (10%). Prevalence of depressive symptoms increased by age for both males and females. Among American Indian youths, 29% reported depressive symptoms, as compared with 22% of Hispanic, 18% of white, 17% of Asian American, and 15% of African American youths. Youths who were frequently involved in bullying, either as perpetrators or as victims, were more than twice as likely to report depressive symptoms than those who were not involved in bullying. A significantly higher percentage of youths who reported using substances reported depressive symptoms as compared with other youths. Similarly, youths who reported experiencing somatic symptoms also reported significantly higher proportions of depressive symptoms than other youths. CONCLUSIONS: Depression is a substantial and largely unrecognized problem among young adolescents that warrants an increased need and opportunity for identification and intervention at the middle school level. Understanding differences in prevalence between males and females and among racial/ethnic groups may be important to the recognition and treatment of depression among youths.

Adolescent↗

PubMed2004

Duration of cognitive impairment after sports concussion.

OBJECTIVE: We sought to determine the duration of cognitive impairment after sports concussion. METHODS: We conducted a study with a prospective design in which 729 athletes underwent preseason baseline testing by being administered a computerized neuropsychological test battery, followed by retesting at regular intervals after they sustained sports-related concussions. A control group consisting of nonconcussed athletes drawn from the same baseline population underwent testing at parallel intervals. RESULTS: Cognitive impairment in this primarily American Academy of Neurology Grade II sample of boxing concussions was apparent on the day of injury and at 1 to 2 days postinjury. Recovery of cognitive performance occurred during the 3- to 7-day interval. Comparison with control subjects showed that absent or attenuated practice effects, in addition to frank deterioration from baseline, were indications of recent concussion. CONCLUSION: The present findings of recovery during the 3- to 7-day interval postinjury are consistent with the American Academy of Neurology Grade II return-to-play practice parameters suggesting a 1-week time-out from participation in contact sports.

Adolescent↗

PubMed2004

Mean total arsenic concentrations in chicken 1989-2000 and estimated exposures for consumers of chicken.

The purpose of this study was to estimate mean concentrations of total arsenic in chicken liver tissue and then estimate total and inorganic arsenic ingested by humans through chicken consumption. We used national monitoring data from the Food Safety and Inspection Service National Residue Program to estimate mean arsenic concentrations for 1994-2000. Incorporating assumptions about the concentrations of arsenic in liver and muscle tissues as well as the proportions of inorganic and organic arsenic, we then applied the estimates to national chicken consumption data to calculate inorganic, organic, and total arsenic ingested by eating chicken. The mean concentration of total arsenic in young chickens was 0.39 ppm, 3- to 4-fold higher than in other poultry and meat. At mean levels of chicken consumption (60 g/person/day), people may ingest 1.38-5.24 microg/day of inorganic arsenic from chicken alone. At the 99th percentile of chicken consumption (350 g chicken/day), people may ingest 21.13-30.59 microg inorganic arsenic/day and 32.50-47.07 microg total arsenic/day from chicken. These concentrations are higher than previously recognized in chicken, which may necessitate adjustments to estimates of arsenic ingested through diet and may need to be considered when estimating overall exposure to arsenic.

Age Factors↗

PubMed2003

Rab27b is associated with fusiform vesicles and may be involved in targeting uroplakins to urothelial apical membranes.

The terminally differentiated umbrella cells of bladder epithelium contain unique cytoplasmic organelles, the fusiform vesicles, which deliver preassembled crystalline arrays of uroplakin proteins to the apical cell surface of urothelial umbrella cells. We have investigated the possible role of Rab proteins in this delivery process, and found Rab27b to be expressed at an extraordinary high level (0.1% of total protein) in urothelium, whereas Rab27b levels were greatly reduced (to <5% of normal urothelium) in cultured urothelial cells, which synthesized only small amounts of uroplakins and failed to form fusiform vesicles. Immuno-electron microscopy showed that Rab27b was associated with the cytoplasmic face of the fusiform vesicles, but not with that of the apical plasma membrane. The association of Rab27b with fusiform vesicles and its differentiation-dependent expression suggest that this Rab protein plays a role in regulating the delivery of fusiform vesicles to the apical plasma membrane of umbrella cells.

Animals↗