Current Resources

Reviews include: The Managed Care Answer Book for Mental Health Professionals. ( 1997) Gayle McCracken Tuttle and Dianne Rush Woods. Bristol, P A: Brunner/Mazel, Inc. Reviewed by Patricia Newlin Somebody Else's Children: and the Struggle to Save America's Troubled Families. (1996) John Hubner and Jill Wolfson. New York: Three Rivers Press. Reviewed by John Nasuti Assessing the Long-Term Effects of Foster Care-A Research Synthesis. (1996) Thomas P. McDonald, Reva I. Allen, Alex Westerfield, and Irving Piliavin. Washington, D.C.: CWLA Press. Reviewed by Anthony N. Ma/uccio

Aboral ectoderm-specific expression and regulation of the LpS1 genes of {\it Lytechinus pictus\/}

The Spec genes serve as molecular markers for examining the ontogeny of the aboral ectoderm lineage of sea urchin embryos. These genes are activated at late-cleavage stage only in cells contributing to the aboral ectoderm of Strongylocentrotus purpuratus and encode 14,000-17,000 Da calcium-binding proteins. A comparative analysis was undertaken to better understand the mechanisms underlying the activation and function of the Spec genes by investigating Spec homologues from Lytechinus pictus, a distantly related sea urchin. Spec antibodies cross-reacted with 34,000 Da proteins in L. pictus embryos that displayed a similar ontogenetic pattern to that of Spec proteins. One cDNA clone, LpS1, was isolated by hybridization to a synthetic oligonucleotide corresponding to a calcium-binding domain or EF-hand. The LpS1 mRNA has developmental properties similar to those of the Spec mRNAs. LpS1 encodes a 34,000 Da protein containing eight EF-hand domains, which share structural homology with the Spec EF-hands; however, little else in the protein sequence is conserved, implying that calcium-binding is important for Spec protein function. Genomic DNA blot analysis showed two LpS1 genes, LpS1$\alpha$ and LpS1$\beta$, in L. pictus. Partial gene structures for both LpS1$\alpha$ and $\beta$ were constructed based on genomic clones isolated from an L. pictus genomic library. These revealed internal duplications of the LpS1 genes that accounted for the eight EF-hand domains in the LpS1 proteins. Sequencing analysis showed there was little in common among the 5$\sp\prime$-flanking regions of the LpS1 and Spec genes except for the presence of a binding site for the transcription factor USF.^ A sea urchin gene-transfer expression system showed that 762 base pairs (bp) of 5$\sp\prime$-flanking DNA from the LpS1$\beta$ gene were sufficient for correct temporal and spatial expression of reporter genes in sea urchin embryos. Deletions at the 5$\sp\prime$ end to 511, 368, or 108bp resulted in a 3-4 fold decrease in chloramphenicol acetyltransferase (CAT) activity and disrupted the restricted activation of the lac Z gene in aboral ectoderm cells.^ A full-length Spec1 protein and a truncated LpS1 protein were induced and partially purified from an in vitro expression system. (Abstract shortened with permission of author.) ^

Origins and evolution of VNTR loci: The apolipoprotein B 3$\sp\prime$ VNTR

I studied the apolipoprotein (apo) B 3$\sp\prime$ variable number tandem repeat (VNTR) and did computer simulations of the stepwise mutation model to address four questions: (1) How did the apo B VNTR originate? (2) What is the mutational mechanism of repeat number change at the apo B VNTR? (3) To what extent are population and molecular level events responsible for the determination of the contemporary apo B allele frequency distribution? (4) Can VNTR allele frequency distributions be explained by a simple and conservative mutation-drift model? I used three general approaches to address these questions: (1) I characterized the apo B VNTR region in non-human primate species; (2) I constructed haplotypes of polymorphic markers flanking the apo B VNTR in a sample of individuals from Lorrain, France and studied the associations between the flanking-marker haplotypes and apo B VNTR size; (3) I did computer simulations of the one-step stepwise mutation model and compared the results to real data in terms of four allele frequency distribution characteristics.^ The results of this work have allowed me to conclude that the apo B VNTR originated after an initial duplication of a sequence which is still present as a single copy sequence in New World monkey species. I conclude that this locus did not originate by the transposition of an array of repeats from somewhere else in the genome. It is unlikely that recombination is the primary mutational mechanism. Furthermore, the clustered nature of these associations implicates a stepwise mutational mechanism. From the high frequencies of certain haplotype-allele size combinations, it is evident that population level events have also been important in the determination of the apo B VNTR allele frequency distribution. Results from computer simulations of the one-step stepwise mutation model have allowed me to conclude that bimodal and multimodal allele frequency distributions are not unexpected at loci evolving via stepwise mutation mechanisms. Short tandem repeat loci fit the stepwise mutation model best, followed by microsatellite loci. I therefore conclude that there are differences in the mutational mechanisms of VNTR loci as classed by repeat unit size. (Abstract shortened by UMI.) ^

Effects of treatment on orienting in Parkinson disease

Parkinson disease (PD) is a movement disorder affecting over one million Americans, and 1% of our population over 60 years of age. Currently, PD has an unknown cause, no predictive biomarker, and no cure, yet there are effective treatments (medicine and surgery) to chronically manage the motor symptoms. But, PD patients also develop cognitive symptoms (e.g., distractibility, executive dysfunction) that remain untreated or may decline as a result of treating the motor symptoms. To address this important issue, I measured covert orienting of attention and overt eye movements in PD patients to assess the patients' ability to automatically detect stimuli in their visual field, to predict and attend to where the stimuli would appear, and to volitionally look somewhere else. ^ PD patients completed the cognitive tasks under multiple treatment conditions, and their performance was compared to healthy adults. PD patients first completed the tasks after they had withdrawn from medication. Their unmedicated performance revealed exaggerated automatic orienting, poor predictability, and weak volitional orienting. PD patients then repeated the tasks while medication was giving its peak benefit. The medication returned automatic covert orienting toward normal but did not improve volitional covert orienting. Several PD patients completed the tasks a third time after receiving surgery (specifically, implantation of stimulating electrodes in a subcortical brain region to alleviate motor symptoms). The stimulation (without medication) returned automatic orienting toward normal, did not change predictability, and further impaired volitional orienting. Taken together, treatments prescribed to alleviate the motor symptoms (a patient's primary concern) only improve some cognitive functions. Future studies may establish criteria to predict which patients are more likely to have cognitive benefit from medication over surgery, or vice versa. ^ I have also hypothesized an anatomical model relating orienting circuitry to abnormal PD circuitry and the therapeutic targets. My results suggest medication is more effective restoring the orienting circuitry than stimulation. Further, automatic and volitional orienting abilities seem to be modulated independently, which differs from an earlier model proposing a dependent, inverse relationship. My results are further discussed in terms of response inhibition, response selection, and the location of the selection. ^