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Biomedical subjects

S L Anderson

Publications and source records attributed to S L Anderson.

At least 19 recordsLinked to original sources
PubMed2005

Timing of prenatal stressors and autism.

Recent evidence supports a role for genetics in autism, but other findings are difficult to reconcile with a purely genetic cause. Pathological changes in the cerebellum in autism are thought to correspond to an event before 30-32 weeks gestation. Our purpose was to determine whether there is an increased incidence of stressors in autism before this time period. Surveys regarding incidence and timing of prenatal stressors were distributed to specialized schools and clinics for autism and Down syndrome, and to mothers of children without neurodevelopmental diagnoses in walk-in clinics. Incidence of stressors during each 4-week block of pregnancy was recorded. Incidence of stressors in the blocks prior to and including the predicted time period (21-32 weeks gestation) in each group of surveys was compared to the other prenatal blocks. A higher incidence of prenatal stressors was found in autism at 21-32 weeks gestation, with a peak at 25-28 weeks. This does support the possibility of prenatal stressors as a potential contributor to autism, with the timing of stressors consistent with the embryological age suggested by neuroanatomical findings seen in the cerebellum in autism. Future prospective studies would be needed to confirm this finding.

Autistic Disorder↗
PubMed2001

Genomic organization and chromosomal localization of the mouse IKBKAP gene.

The autosomal recessive disorder familial dysautonomia (FD) has recently been demonstrated to be caused by mutations in the IKBKAP gene, so named because an initial report suggested that it encoded an IkappaB kinase complex associated protein (IKAP). Two mutations in IKBKAP have been reported to cause FD. The major mutation is a T-->C transition in the donor splice site of intron 20 and the minor mutation is a missense mutation in exon 19 that disrupts a consensus serine/threonine kinase phosphorylation site. We have characterized the cDNA sequences of the mouse, rat and rabbit IKBKAP-encoded mRNAs and determined the genomic organization and chromosomal location of mouse IKBKAP. There is significant homology in the amino acid sequence of IKAP across species and the serine/threonine kinase phosphorylation site altered in the minor FD mutation of IKAP is conserved. The mouse and human IKBKAP genes exhibit significant conservation of their genomic organization and the intron 20 donor splice site sequence, altered in the major FD mutation, is conserved in the human and mouse genes. Mouse IKBKAP is located on the central portion of chromosome 4 and maps to a region in which there is conserved linkage homology between the human and mouse genomes. The homologies observed in the human and mouse sequences should allow, through the process of homologous recombination, for the generation of mice that bear the IKBKAP mutations present in individuals with FD. The characterization of such mice should provide significant information regarding the pathophysiology of FD.

Amino Acid Sequence↗
PubMed2001

Familial dysautonomia is caused by mutations of the IKAP gene.

The defective gene DYS, which is responsible for familial dysautonomia (FD) and has been mapped to a 0.5-cM region on chromosome 9q31, has eluded identification. We identified and characterized the RNAs encoded by this region of chromosome 9 in cell lines derived from individuals homozygous for the major FD haplotype, and we observed that the RNA encoding the IkappaB kinase complex-associated protein (IKAP) lacks exon 20 and, as a result of a frameshift, encodes a truncated protein. Sequence analysis reveals a T-->C transition in the donor splice site of intron 20. In individuals bearing a minor FD haplotype, a missense mutation in exon 19 disrupts a consensus serine/threonine kinase phosphorylation site. This mutation results in defective phosphorylation of IKAP. These mutations were observed to be present in a random sample of Ashkenazi Jewish individuals, at approximately the predicted carrier frequency of FD. These findings demonstrate that mutations in the gene encoding IKAP are responsible for FD.

Amino Acid Sequence↗
PubMed2001

Effects of contaminants on genetic patterns in aquatic organisms: a review.

There is increasing awareness of the need to evaluate the effects of contaminants at the population level. Genetic techniques offer a powerful approach to assess contaminant-induced changes in populations. Yet studies to date are relatively few and not always carefully designed to maximize the utility inherent in this approach. We present a summary of contemporary genetic assessment methods and a review of published studies of genetic effects in field-exposed aquatic organisms. We discuss evaluations of genetic patterns that use genetic adaptation, allozyme variation, and molecular genetic (DNA) variation. Direct tests of genetic adaptation are very effective in establishing a concrete, and potentially deleterious population-level effect of contaminant exposure, but they are difficult to accomplish with most field-exposed organisms. Allozyme surveys are relatively simple and common, and may provide data that are suggestive of contaminant effects. However, these are rarely conclusive, primarily because few allozyme loci are variable and these few loci represent extremely small portions of the genome. Molecular genetic techniques have the potential to be very effective. But, there is a tendency to emphasize the power of the techniques, rather than the underlying causes of the molecular genetic patterns observed. The strength of the conclusions of each study varies widely, partially derived from variation in the strength of the techniques. We caution that all these approaches are greatly improved by careful experimental design that includes adequate numbers of reference and contaminated sites and sample size. In addition, careful exposure assessment is required, including site and tissue chemistry, biomarker responses, and measures of potentially deleterious effects, such as DNA damage, or reduced reproductive output or survival.

Animals↗
PubMed2001

Brief report: macrographia in high-functioning adults with autism spectrum disorder.

The initial description of Asperger syndrome commented on the poor handwriting and motor coordination difficulties of individuals with this condition. Early descriptions of autism do not remark upon such difficulties. Recent evidence, however, suggests that individuals with both conditions have a similar motor control impairment. Handwriting has not been formally assessed in this context. Our study compared handwriting size between individuals with autism spectrum disorder and age- and IQ-matched control subjects. Macrographia was observed among subjects with autism spectrum disorder which remained statistically significant when covaried with educational level. This finding may correlate with the anatomical abnormalities present in the cerebellum of individuals with autism spectrum disorder.

Adolescent↗
PubMed2001

Choice of methodology for assessing genetic impacts of environmental stressors: polymorphism and reproducibility of RAPD and AFLP fingerprints.

PCR-based multi-locus DNA fingerprints represent one of the most informative and cost-effective measures of genetic diversity and are useful population-level biomarkers of toxicologic and other anthropogenic impacts. However, concerns about reproducibility of DNA fingerprints have limited their wider use in environmental biology. We assessed polymorphism and reproducibility of two common fingerprinting techniques, RAPD (randomly amplified polymorphic DNA) and AFLP (amplified fragment length polymorphism), in pedigreed populations of rainbow trout (Oncorhynchus mykiss) to derive general rules for selective removal of problematic fingerprint bands. We found that by excluding bands that comprised less than 1% of total intensity, and by excluding the largest and smallest 10% of the bands, we could achieve nearly 100% reproducibility of AFLP fingerprints. Similar application of band exclusion criteria to RAPD fingerprints did not significantly enhance their reproducibility, and at least 15% of RAPD bands were not fully repeatable, heritable, or transmittable. The RAPD technique produced more polymorphic fingerprints than AFLP; however, considering that a substantial proportion of RAPD markers did not demonstrate Mendelian inheritance patterns, the AFLP methodology is to be preferred for future research.

Animals↗
PubMed2001

Enhanced cell polarity in mutants of the budding yeast cyclin-dependent kinase Cdc28p.

The yeast cyclin-dependent kinase Cdc28p regulates bud morphogenesis and cell cycle progression via the antagonistic activities of Cln and Clb cyclins. Cln G1 cyclins direct polarized growth and bud emergence, whereas Clb G2 cyclins promote isotropic growth of the bud and chromosome segregation. Using colony morphology as a screen to dissect regulation of polarity by Cdc28p, we identified nine point mutations that block the apical-isotropic switch while maintaining other functions. Like a clb2 Delta mutation, each confers tubular bud shape, apically polarized actin distribution, unipolar budding, and delayed anaphase. The mutations are all suppressed by CLB2 overexpression and are synthetically lethal with a CLB2 deletion. However, defects in multiple independent pathways may underlie their common phenotype, because the mutations are scattered throughout the CDC28 sequence, complement each other, and confer diverse biochemical properties. Glu12Gly, a mutation that alters a residue involved in Swe1p inhibition of Cdc28p, was unique in being suppressed by deficiency of SWE1 or CLN1. With wild-type CDC28, filament formation induced by CLN1 overexpression was markedly decreased in a SWE1 deletion. These results suggest that Swe1p, via inhibition of Clb2p/Cdc28p, may mediate much of the effect of Cln1p on filamentous morphogenesis.

Alleles↗
PubMed2000

Allosteric inhibition of NAD+-specific isocitrate dehydrogenase by a mitochondrial mRNA.

NAD+-specific isocitrate dehydrogenase (IDH) has been reported to bind sequences in 5'-untranslated regions of yeast mitochondrial mRNAs. In the current study, an RNA transcript containing the 5'-untranslated region of the mRNA from the yeast mitochondrial COX2 gene is shown to be an allosteric inhibitor of the affinity-purified yeast enzyme. At 0.1 microM concentrations of the transcript, velocity of the IDH reaction is reduced to 20% of the value obtained in the absence of the RNA transcript. This inhibition is due to a 2. 5-fold increase in the S0.5 value for isocitrate. Significant inhibition of IDH activity is also obtained with a transcript containing a portion of the 5'-untranslated region of the yeast mitochondrial ATP9 gene and with an antisense form of the COX2 transcript, both of which contain potential stem-loop secondary structures implicated in binding of IDH. In contrast, much higher concentrations of yeast tRNA or poly(A)mRNA, respectively, 33- and 60-fold greater than that required for the COX2 transcript, are required to produce a 50% decrease in velocity. These results suggest that inhibition of activity is relatively specific for the 5'-untranslated regions of mitochondrial mRNAs. All measurable inhibition of IDH activity by RNA is eliminated by addition of 100 microM concentrations of the allosteric activator AMP. At equivalent concentrations, dAMP is less efficient than AMP as an allosteric activator of IDH and is proportionally less effective in protecting against inhibition of activity by the COX2 transcript. Other nucleotides that are not allosteric activators fail to protect IDH activity from inhibitory effects of RNA. Thus, alleviation of catalytic inhibition of IDH by mitochondrial mRNA correlates with the property of allosteric activation.

5' Untranslated Regions↗
PubMed1999

Interferon-induced guanylate binding protein-1 (GBP-1) mediates an antiviral effect against vesicular stomatitis virus and encephalomyocarditis virus.

A cDNA encoding the human guanylate binding protein-1 (hGBP-1) was expressed in HeLa cells using a constitutive expression vector. Stably transfected clones expressing hGBP-1 exhibited resistance to the cytopathic effect mediated by both vesicular stomatitis virus (VSV) and encephalomyocarditis virus (EMCV) and produced less viral progeny than control cells following infection with these viruses. To study the role hGBP-1 plays in the IFN-mediated antiviral effect, cells were stably transfected with a construct expressing antisense RNA for hGBP-1. VSV infection of IFN-alpha-treated antisense RNA-expressing cells produced an amount of virus comparable to that produced in the parental cell line, while EMCV infection of the IFN-alpha-treated transfected cells and VSV and EMCV infection of the IFN-gamma-treated transfected cells produced far more virus than was produced in the parental cell line. These results demonstrate that GBP-1 mediates an antiviral effect against VSV and EMCV and plays a role in the IFN-mediated antiviral response against these viruses.

DNA-Binding Proteins↗
PubMed1999

Knowledge, attitudes, and behaviors of college students regarding the 1990 Nutrition Labeling Education Act food labels.

OBJECTIVES: This study examined the influence of 1990 Nutrition Labeling and Education Act food labels on college students. The purposes of the study were to examine knowledge, attitudes, and behaviors of college students regarding labels and relationships among these factors, and whether educational experience with labels was associated with label-reading knowledge, attitudes, and behaviors. DESIGN: A descriptive, nonexperimental research design was used. Data were gathered using a survey designed for the study. SUBJECTS: The study surveyed 208 undergraduate students enrolled in general education classes at a midwestern university. STATISTICAL ANALYSIS: Descriptive statistics analyzed knowledge, attitudes, and behaviors of college students regarding food labels. The Student t test and chi 2 analysis evaluated specific measures of behavior. Pearson correlation coefficients and multiple regression analysis examined relationships among variables and identified factors associated with label use. RESULTS: Students' mean knowledge score was 48%. Knowledge score was positively correlated with attitudes toward labels (r = .14, P = .04) and use of labels (r = .87, P = .0001). Previous education in reading labels was associated with higher knowledge scores (P = .04). Ninety-five percent of participants perceived the label to be useful, but many distrusted nutrition claims. Seventy percent looked at the Nutrition Facts label when purchasing a product for the first time. The single best predictor of general label use was a positive attitude toward labels (P < .001), followed by being a woman (P < .01). CONCLUSIONS: The 1990 National Labeling and Education Act food label has influenced college students. Labeling education efforts are associated with greater knowledge about labels, more favorable attitudes toward them, and increased label use in making food choices. Special attention should be directed toward explaining terms and phrases on labels and the guidelines that ensure truthfulness of nutrition claims. College students need to understand their need for numerous nutrients instead of merely focusing on the fat and caloric content of foods.

Adolescent↗
PubMed1999

Genomic organization and chromosomal localization of a new member of the murine interferon-induced guanylate-binding protein family.

An RNA species has been identified whose nucleotide sequence is closely related to the mRNA encoding the murine interferon (IFN)-induced guanylate-binding protein-1 (mGBP1) and an mRNA encoding an isoprenylated protein that is constitutively expressed in various organs in the rat. Sequence analysis of the gene encoding this newly identified RNA reveals that in its 5'-region it is identical to a DNA fragment reported to represent the 5'-region of a gene termed mGBP2. In light of this homology, we term this newly identified gene product mGBP2. mGBP2 is inducible following IFN treatment in animals bearing Gbp1a alleles, in which mGBP1 is transcriptionally upregulated by IFN treatment, as well as in animals bearing Gbp1b alleles, in which mGBP1 is not induced in response to IFN treatment. The genomic organizations of the genes encoding mGBP1 and mGBP2 are similar, and the nucleotide sequences of their IFN-responsive-like elements and their relative locations are conserved. Gbp1 and Gbp2 map to a genetically indistinguishable site on the distal arm of chromosome 3.

Animals↗
PubMed1999

Allied health applications of a computerized clinical log database system.

Preliminary research in the development and use of computerized clinical log records began in 1987 in an allied health college at a midwestern academic health center. This article reviews development and implementation of a computerized system for managing clinical log records to improve and enhance allied health educational programs in the radiation sciences. These clinical log databases are used for quantitative and qualitative analyses of student participation in clinical procedures, and educational planning for each student. Collecting and recording data from clinical log records serves as a valuable instructional tool for students, with both clinical and didactic applications.

Accreditation↗
PubMed1998

The effect of semantic and emotional context on written recall for verbal language in high functioning adults with autism spectrum disorder.

OBJECTIVE: Several deficits have been proposed to account for cognitive impairment in autism including an inability to comprehend the perspectives of others ("theory of mind"), an inability to process emotional information, and difficulty drawing together diverse information in context ("central coherence"). Because context (central coherence) and emotion can influence memory, a study was designed to show if autism spectrum disorder was associated with impaired utilisation of context and emotion in recall; and if impairments in theory of mind processing would influence recall in autism spectrum disorder. METHODS: Ten high functioning subjects with autism spectrum disorder and 13 age and IQ matched controls were tested using recall tests. In the first coherence memory test, subjects listened to a series of word lists that were in varying degrees of syntactic and semantic (coherent) order and were asked to recall the words. In the second coherence memory test, subjects listened to stories consisting of sentences that were, or were not, in logical (coherent) order. In the emotional memory test, the subjects listened to sentences that were highly emotional or non-emotional. In the theory of mind test, the subjects listened to stories requiring varying levels of understanding of the perspectives of others. RESULTS: There were no significant differences between groups in recall of coherent versus incoherent word lists, nor was there a significant difference between groups in recall of coherent versus incoherent stories. However, the control subjects recalled more of the emotional than non-emotional sentences, whereas the autism spectrum disorder group did not show such a difference. No significant difference existed in recall of stories requiring varying levels of understanding of the perspectives of others among subjects with autism spectrum disorder, and subjects with autism spectrum disorder did not differ from control subjects in the influence of theory of mind content on story recall. CONCLUSION: The study shows that memory in high functioning adults with autism spectrum disorder is facilitated by emotional content to a lesser degree than it is facilitated by coherence. Therefore, impairments in emotional processing cannot be considered as simply an effect of the "weak central coherence" theory in autism spectrum disorder. Whereas the reasons for this emotional deficit are unknown, evidence of abnormalities of the limbic structures in autism spectrum disorder may provide an anatomical explanation.

Adult↗
PubMed1997

Attenuation of phytochrome A and B signaling pathways by the Arabidopsis circadian clock.

In higher plants, environmental cues such as light signals are integrated with circadian clock signals to control precisely the daily rhythms observed for many biological functions. We have used a fusion of the promoter of a chlorophyll a/b binding protein gene, CAB2, with firefly luciferase (cab2::luc) to monitor the detailed kinetics of transcription in response to photoreceptor activation in Arabidopsis. Using this marker in phototransduction and circadian-dysfunctional mutants, we studied how signals from phytochrome and the circadian clock are integrated for the regulation of CAB2 transcription. Results from these mutant studies demonstrate that similar expression features, namely, the acute and circadian responses, are present in both etiolated and green seedlings and that the acute and circadian responses are genetically separable. We also demonstrate that persistent Pfr signaling occurs in red light-pulsed etiolated seedlings, which suggests that the circadian clock antagonizes Pfr-mediated signal transduction. Based on these genetic studies, we propose a model for the regulation of CAB2 transcription in which individual photoreceptors and phototransduction components have been assigned to specific pathways for the regulation of discrete kinetic components of the CAB2 expression pattern.

Arabidopsis↗
PubMed1997

A descriptive study of breastfeeding practices and policies in Missouri hospitals.

All Missouri hospitals that offer maternity services were assessed to measure their compliance with WHO/UNICEF Baby Friendly Hospital Initiative (BFHI). Representatives from seventy six hospitals responded to a telephone survey relating to hospital breastfeeding practices and policies as defined by BFHI's Ten Steps to Successful Breastfeeding. No hospital fully supported the Ten Steps. Compliance with the WHO/UNICEF criteria varied greatly. The least support was for Step I, only 28% of hospitals had a written breastfeeding policy that was communicated to all staff. The greatest support was for Step 3, 93% of hospitals had staff who informed all pregnant women of breastfeeding benefits. In order to increase breastfeeding rates and duration, administrators of hospitals that offer maternity services must increase their efforts to consistently implement the Ten Steps, to become more baby friendly, and to more fully establish a breastfeeding culture within their institutions.

Breast Feeding↗
PubMed1996

Use of alternative polyadenylation sites in the synthesis of mRNAs encoding the interferon-induced tryptophanyl tRNA synthetase.

The interferon-mediated induction of the gene encoding the human tryptophanyl tRNA synthetase (WRS) results in the production of two mRNA species differing in size by approximately 800 base pairs (bp). Two distinctly sized cDNAs differing by approximately 800 bp were isolated from a cDNA library generated from mRNA prepared from IFN-gamma-treated cells. Northern blot analysis using cDNA probes recognizing different regions of the WRS mRNA reveals distinctly sized mRNAs differing in the length of their 3' untranslated regions. Differential display analysis using oligo dT primers demonstrates that the different sized WRS mRNAs result from alternative polyadenylation of this transcript.

Alternative Splicing↗