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Biomedical subjects

William Wood

Publications and source records attributed to William Wood.

18 recordsLinked to original sources
PubMed2006

Alterations in immunological and neurological gene expression patterns in Alzheimer's disease tissues.

Microarray technology was utilized to isolate disease-specific changes in gene expression by sampling across inferior parietal lobes of patients suffering from late onset AD or non-AD-associated dementia and non-demented controls. Primary focus was placed on understanding how inflammation plays a role in AD pathogenesis. Gene ontology analysis revealed that the most differentially expressed genes related to nervous system development and function and neurological disease followed by genes involved in inflammation and immunological signaling. Pathway analysis also implicated a role for chemokines and their receptors, specifically CXCR4 and CCR3, in AD. Immunohistological analysis revealed that these chemokine receptors are upregulated in AD patients. Western analysis demonstrated an increased activation of PKC, a downstream mediator of chemokine receptor signaling, in the majority of AD patients. A very specific cohort of genes related to amyloid beta accumulation and clearance were found to be significantly altered in AD. The most significantly downregulated gene in this data set was the endothelin converting enzyme 2 (ECE2), implicated in amyloid beta clearance. These data were subsequently confirmed by real-time PCR and Western blot analysis. Together, these findings open up new avenues of investigation and possible therapeutic strategies targeting inflammation and amyloid clearance in AD patients.

Aged↗
PubMed2006

A rapid method for microarray cross platform comparisons using gene expression signatures.

Microarray technology has become highly valuable for identifying complex changes in global gene expression patterns. The inevitable use of a variety of different platforms has compounded the difficulty of effectively comparing data between projects, laboratories, and public access databases. The need for consistent, believable results across platforms is fundamental and methods for comparing results across platforms should be as straightforward as possible. We present the results of a study comparing three major, commercially available, microarray platforms (Affymetrix, Agilent, and Illumina). Concordance estimates between platforms was based on mapping of probes to Human Gene Organization (HUGO) gene names. Appropriate data normalization procedures were applied to each dataset followed by the generation of lists of regulated genes using a common significance threshold for all three platforms. As expected, concordance measured by directly comparing gene lists was relatively low (an average 22.8% for all platforms across all possible comparisons). However, when statistical tests (gene set enrichment analysis--GSEA, parametric analysis of gene enrichment--PAGE) which align gene lists with continuous measures of differential gene expression were applied to the cross platform datasets using significant gene lists to poll entire datasets, the relatedness of the results from all three platforms was specific, obvious, and profound.

Animals↗
PubMed2005

Imaging cell movement during dorsal closure in Drosophila embryos.

During Drosophila embryogenesis, many cells and tissues undergo complex morphogenetic movements, such as ventral furrow formation, germ band extension and retraction, and dorsal closure. The best way to study and understand the cell behaviors during such tissue movements is to image them live using time course analysis. The Drosophila embryo lends itself perfectly to live imaging for several reasons: powerful genetics allow transgenic embryos expressing green fluorescent protein-fusion proteins to be quickly and easily generated and the expression domains of these reporters can be efficiently controlled using the GAL4-upstream activator sequence system. Embryos will survive for several hours mounted on a slide in a gas-permeable oil, such as Voltalef or Halocarbon, during which time they will undergo normal development and can be easily imaged using a confocal laser scanning microscope. Here, we describe in detail a protocol for live imaging of Drosophila embryos which, in our hands, is routinely used to study dorsal closure but is suitable for the live study of any process involving cell motility, be it a coordinated tissue movement such as dorsal closure or the movement of individual cells such as hemocytes within the embryo.

Animals↗
PubMed2004

Lumpectomy plus tamoxifen with or without irradiation in women 70 years of age or older with early breast cancer.

BACKGROUND: In women 70 years of age or older who have early breast cancer, it is unclear whether lumpectomy plus tamoxifen is as effective as lumpectomy followed by tamoxifen plus radiation therapy. METHODS: Between July 1994 and February 1999, we randomly assigned 636 women who were 70 years of age or older and who had clinical stage I (T1N0M0 according to the tumor-node-metastasis classification), estrogen-receptor-positive breast carcinoma treated by lumpectomy to receive tamoxifen plus radiation therapy (317 women) or tamoxifen alone (319 women). Primary end points were the time to local or regional recurrence, the frequency of mastectomy for recurrence, breast-cancer-specific survival, the time to distant metastasis, and overall survival. RESULTS: The only significant difference between the two groups was in the rate of local or regional recurrence at five years (1 percent in the group given tamoxifen plus irradiation and 4 percent in the group given tamoxifen alone, P<0.001). There were no significant differences between the two groups with regard to the rates of mastectomy for local recurrence, distant metastases, or five-year rates of overall survival (87 percent in the group given tamoxifen plus irradiation and 86 percent in the tamoxifen group, P=0.94). Assessment by physicians and patients of cosmetic results and adverse events uniformly rated tamoxifen plus irradiation inferior to tamoxifen alone. CONCLUSIONS: Lumpectomy plus adjuvant therapy with tamoxifen alone is a realistic choice for the treatment of women 70 years of age or older who have early, estrogen-receptor-positive breast cancer.

Aged↗
PubMed2004

Multiple Wnt signaling pathways converge to orient the mitotic spindle in early C. elegans embryos.

How cells integrate the input of multiple polarizing signals during division is poorly understood. We demonstrate that two distinct Caenorhabditis elegans Wnt pathways contribute to the polarization of the ABar blastomere by differentially regulating its duplicated centrosomes. Contact with the C blastomere orients the ABar spindle through a nontranscriptional Wnt spindle alignment pathway, while a Wnt/beta-catenin pathway controls the timing of ABar spindle rotation. The three C. elegans Dishevelled homologs contribute to these processes in different ways, suggesting that functional distinctions may exist among them. We also find that CKI (KIN-19) plays a role not only in the Wnt/beta-catenin pathway, but also in the Wnt spindle orientation pathway as well. Based on these findings, we establish a model for the coordination of cell-cell interactions and distinct Wnt signaling pathways that ensures the robust timing and orientation of spindle rotation during a developmentally regulated cell division event.

Alleles↗
PubMed2003

Vaccination of women with metastatic breast cancer, using a costimulatory gene (CD80)-modified, HLA-A2-matched, allogeneic, breast cancer cell line: clinical and immunological results.

MDA-MB-231, an HLA-A2(+), HER2/neu(+) allogeneic breast cancer cell line genetically modified to express the costimulatory molecule CD80 (B7-1), was used to vaccinate 30 women with previously treated stage IV breast cancer. Expression of CD80 conferred the ability to deliver a costimulatory signal and thereby improved the antigen presentation capability of the tumor cells to patient T cells in vitro. Patients were vaccinated with 10(7) or 10(8) irradiated gene-modified tumor cells with granulocyte-macrophage colony-stimulating factor (GM-CSF) or BCG, three times at 2-week intervals and then monthly until progressive disease developed. GM-CSF-related flulike symptoms and minor injection site reactions were observed frequently. Prolonged disease stabilization was observed in four patients but no objective tumor regressions were seen. Immune responses were measured in matched peripheral blood samples collected before and after treatment from 9 of 15 patients treated at the 10(8) tumor cell dose. Four patients exhibited MHC class I-restricted cytokine production in response to the parental breast cancer cell line. One patient maintained an increased number of circulating tumor-specific, interferon gamma-secreting CD8(+) T cells for 24 months after the last vaccination. One patient exhibited a tumor-specific interleukin 5 response to an autologous tumor cell line. This immunization strategy proved to be safe and feasible, and induced tumor-specific immune responses in a minority of patients; however, no objective tumor regressions were observed.

Adult↗
PubMed2003

Adjuvant immunization of HLA-A2-positive melanoma patients with a modified gp100 peptide induces peptide-specific CD8+ T-cell responses.

PURPOSE: To measure the CD8+ T-cell response to a melanoma peptide vaccine and to compare an every-2-weeks with an every-3-weeks vaccination schedule. PATIENTS AND METHODS: Thirty HLA-A2-positive patients with resected stage I to III melanoma were randomly assigned to receive vaccinations every 2 weeks (13 vaccines) or every 3 weeks (nine vaccines) for 6 months. The synthetic, modified gp100 peptide, g209-2M, and a control peptide, HPV16 E7, were mixed in incomplete Freund's adjuvant and injected subcutaneously. Peripheral blood mononuclear cells obtained before and after vaccination by leukapheresis were analyzed using a fluorescence-based HLA/peptide-tetramer binding assay and cytokine flow cytometry. RESULTS: Vaccination induced an increase in peptide-specific T cells in 28 of 29 patients. The median frequency of CD8+ T cells specific for the g209-2M peptide increased markedly from 0.02% before to 0.34% after vaccination (P <.0001). Eight patients (28%) exhibited peptide-specific CD8+ T-cell frequencies greater than 1%, including two patients with frequencies of 4.96% and 8.86%, respectively. Interferon alfa-2b-treated patients also had significant increases in tetramer-binding cells (P <.0001). No difference was observed between the every-2-weeks and the every-3-weeks vaccination schedules (P =.59). CONCLUSION: Flow cytometric analysis of HLA/peptide-tetramer binding cells was a reliable means of quantifying the CD8+ T-cell response to peptide immunization. This assay may be suitable for use in future trials to optimize different vaccination strategies. Concurrent interferon treatment did not inhibit the development of a peptide-specific immune response and vaccination every 2 weeks, and every 3 weeks produced similar results.

Adult↗
PubMed2002

Dynamic analysis of actin cable function during Drosophila dorsal closure.

Throughout development, a series of epithelial movements and fusions occur that collectively shape the embryo. They are dependent on coordinated reorganizations and contractions of the actin cytoskeleton within defined populations of epithelial cells. One paradigm morphogenetic movement, dorsal closure in the Drosophila embryo, involves closure of a dorsal epithelial hole by sweeping of epithelium from the two sides of the embryo over the exposed extraembryonic amnioserosa to form a seam where the two epithelial edges fuse together. The front row cells exhibit a thick actin cable at their leading edge. Here, we test the function of this cable by live analysis of GFP-actin-expressing embryos in which the cable is disrupted by modulating Rho1 signaling or by loss of non-muscle myosin (Zipper) function. We show that the cable serves a dual role during dorsal closure. It is contractile and thus can operate as a "purse string," but it also restricts forward movement of the leading edge and excess activity of filopodia/lamellipodia. Stripes of epithelium in which cable assembly is disrupted gain a migrational advantage over their wild-type neighbors, suggesting that the cable acts to restrain front row cells, thus maintaining a taut, free edge for efficient zippering together of the epithelial sheets.

Actins↗
PubMed2002

Epithelial fusions in the embryo.

Morphogenesis in the embryo involves the bending, folding and fusing of epithelial tissues to create the final complex shapes of the various organs and structures in the body. One essential process that occurs frequently during development is the drawing together and fusion of epithelial edges. Drosophila dorsal closure is perhaps the most genetically tractable of this type of movement, and several recent advances have revealed much about the signals regulating the dynamic actin cytoskeletal machineries that underlie the zippering-closed of this hole in the embryonic fly. It is now clear that there are intriguing parallels with more complex morphogenetic tissue movements in vertebrates.

Actins↗
PubMed2002

Structures in focus--filopodia.

Filopodia are thin cell surface extensions filled with tight parallel bundles of actin filaments. They are highly dynamic structures which rapidly extend and retract as well as sweep up and down and from side to side, and can be found at the leading edge of many types of motile cells such as fibroblasts and keratinocytes, as well as the growth cone tips of migrating axons. Cells appear to use filopodia to explore the extracellular matrix (ECM) and surfaces of other cells, identifying appropriate targets for adhesion or in the case of a migrating growth cone, for sensing guidance cues that enable the axon to navigate to it's appropriate target. As well as this sensory role, filopodia have also recently been shown to play an important mechanical role in epithelial adhesion, and are likely to be key players in developmental processes that require migrating epithelial sheets to zipper and fuse to one another. Their dynamic properties as well as their tendency to be damaged or lost after fixation mean they are best analysed using live imaging techniques. As this field improves, the number of tissues in which filopodia are seen to be playing key roles is fast increasing.

Animals↗
PubMed2002

Wound healing recapitulates morphogenesis in Drosophila embryos.

The capacity to repair a wound is a fundamental survival mechanism that is activated at any site of damage throughout embryonic and adult life. To study the cell biology and genetics of this process, we have developed a wounding model in Drosophila melanogaster embryos that allows live imaging of rearrangements and changes in cell shape, and of the cytoskeletal machinery that draws closed an in vivo wound. Using embryos expressing green fluorescent protein (GFP) fusion proteins, we show that two cytoskeletal-dependent elements -- an actin cable and dynamic filopodial/lamellipodial protrusions -- are expressed by epithelial cells at the wound edge and are pivotal for repair. Modulating the activities of the small GTPases Rho and Cdc42 demonstrates that these actin-dependent elements have differing cellular functions, but that either alone can drive wound closure. The actin cable operates as a 'purse-string' to draw the hole closed, whereas filopodia are essential for the final 'knitting' together of epithelial cells at the end of repair. Our data suggest a more complex model for epithelial repair than previously envisaged and highlight remarkable similarities with the well-characterized morphogenetic movement of dorsal closure in Drosophila.

Actins↗
PubMedDate not supplied

Adoptive cellular therapy with tumor vaccine draining lymph node lymphocytes after vaccination with HLA-B7/beta2-microglobulin gene-modified autologous tumor cells.

Adoptive immunotherapy with anti-CD3-expanded lymphocytes from lymph nodes draining alloantigen gene-modified autologous tumor vaccines is an effective treatment of poorly immunogenic murine tumors. This phase I/II study was performed to determine the feasibility and toxicity of combining ex vivo gene transfer of autologous tumor cells and adoptive immunotherapy with anti-CD3-expanded tumor vaccine draining lymph node lymphocytes (TVDLN) in patients with metastatic melanoma and renal cell cancer (RCC). To facilitate the generation of tumor-specific lymphocytes in the TVDLN, autologous tumor cells were modified by gene transfer ex vivo to express the alloantigen HLA-B7, a modification that has the potential to enhance the immunogenicity of the tumor cells. After vaccination with gene-modified tumor cells, patients' lymph nodes were harvested; TVDLN lymphocytes were activated and expanded ex vivo with anti-CD3 and interleukin-2 (IL-2), and adoptively transferred to patients in combination with systemic IL-2. Twenty patients, nine with melanoma and 11 with RCC were treated. Tumor was harvested successfully in all 20 patients. Ex vivo gene transfer was performed using lipofection with a lipid: DNA plasmid complex containing the genes for HLA-B7 and beta2-microglobulin. The mean expression of HLA-B7 by autologous tumor cells after gene transfer was 4.53% (range 0.3%-12.1%). Lymph nodes were harvested from all 20 patients with a mean of 53 x 107 and 60 x 107 cells obtained from the gene-modified and unmodified tumor vaccine sites, respectively. Successful expansion of adequate TVDLN was accomplished in 19 of 20 harvests of unmodified vaccines and in 18 of 20 gene-modified vaccines. No major toxicities were noted after vaccination with autologous tumor cells or adoptive transfer of ex vivo activated TVDLN lymphocytes. Typical IL-2-related toxicities were observed in all patients. No objective tumor regressions were observed. MHC class I restricted, tumor-specific cytokine secretion was observed in lymphocytes from TVDLN and the peripheral blood of vaccinated patients.

Adult↗
PubMedDate not supplied

Prospective evaluation of implants connected to teeth.

PURPOSE: This prospective clinical trial examined the effect on teeth and implants when rigidly or non-rigidly connected in a cross-arch model. MATERIALS AND METHODS: Thirty patients received 2 implants, 1 on each side of the mandible, and were restored with 3-unit fixed partial dentures connected either rigidly or non-rigidly to an abutment tooth. Patients were followed for at least 5 years post-restoration. RESULTS: Repeated-measures analysis revealed no significant difference in crestal bone loss at implants (rigid versus non-rigid methods). An overall significant difference (P < .001) was found comparing methods for teeth. Paired t tests revealed no significant differences in crestal bone levels for implants or teeth at the 5-year recall. Kaplan-Meier methods and the Cox proportional hazards model showed no differences between attachment methods with regard to success based on survival and bone loss criteria. During the 5-year recall period, 1 implant (rigid side) was removed. Four implants developed bone loss greater than 2 mm during the course of this trial. One tooth on the rigid side and 2 teeth on the non-rigid side had greater than 2 mm of crestal bone loss and were removed secondary to fractures. In all, 5 abutment teeth were removed, all of which had been treated with root canal therapy and fractured at the interface of the post within the tooth. There was no clear relationship of tooth fracture to attachment. Repeated-measures analysis of mobility values revealed no significant changes over the time course of this study, and paired t tests revealed no statistically significant differences between implants for mobility. Repeated-measures analysis and paired t tests for probing depth revealed no significant changes over the time course of this study. There were no significant differences in soft tissue indices for either attachment method. The percentage of patients who had measurable intrusion was 66% for the non-rigid group, and 44% for the rigid group; 25% of the non-rigid teeth had greater than 0.5 mm intrusion, compared with 12.5% for the rigid group. For the 2 time periods evaluated, there was no significant increase in intrusion over time. The non-rigid-side implant required more nonscheduled visits to treat problems than the rigid implant and the teeth. DISCUSSION: Most patients were treated successfully with rigid or non-rigid attachment of implants to teeth. CONCLUSION: The high incidence of intrusion and non-scheduled patient visits suggest that alternative treatments without connecting implants to teeth may be indicated.

Adult↗