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Biomedical subjects

M Waugh

Publications and source records attributed to M Waugh.

At least 19 recordsLinked to original sources
PubMed2005

Autografting followed by rituximab for chemosensitive mantle cell lymphoma: a pilot study and literature review.

Mantle cell lymphoma (MCL) is rarely cured with either conventional-dose chemotherapy or autografting. Recent evidence suggests that anti-CD20 monoclonal antibody therapy (rituximab) in combination with chemotherapy may improve the response rate. We report a pilot study of autografting using busulfan-melphalan conditioning followed by rituximab in 9 patients (median age 52 years) with chemosensitive MCL. Rituximab was given for 4 doses of 375 mg/m(2) between 4 and 10 weeks post-transplant. Three of 5 patients autografted after induction therapy remain alive in clinical and molecular complete remission at 33-50 months post-transplant. Only 1 of 4 patients autografted after relapse remains in complete remission. Two of the 3 patients with persistent marrow molecular positivity post-autograft became negative after rituximab therapy. Molecular negativity was first observed in 2 patients only after rituximab therapy. Overall, 2 patients have relapsed and the remaining 3 died of late-onset respiratory failure, probably reflecting infection and/or aggressive conditioning in an older patient population. These preliminary results, together with a review of the literature, suggest that the combination of autografting and rituximab may lead to durable molecular remissions in patients with chemosensitive MCL. Further studies are required to clarify whether the administration of rituximab: (1) is optimal pre- or post-autograft and (2) impacts on the incidence of infection and idiopathic pneumonitis in this context.

Antibodies, Monoclonal↗
PubMed2001

Pharmacokinetic-pharmacodynamic relationships of the bispecific antibody MDX-H210 when administered in combination with interferon gamma: a multiple-dose phase-I study in patients with advanced cancer which overexpresses HER-2/neu.

INTRODUCTION: MDX-H210 is a Fab'xFab' bispecific antibody (BsAb) constructed chemically by crosslinking Fab' mAb 520C9 (anti-HER-2/neu) and Fab' mAbH22 (anti-CD64). STUDY DESIGN AND OBJECTIVES: This was a dose escalation study of intravenous MDX-H210 (1-70 mg/m(2)), preceded 24 h beforehand by subcutaneous IFNgamma (50 microg/m(2) to up-regulate FcgammaRI) administered three times a week for 3 weeks. We investigated the pharmacokinetic-pharmacodynamic relationships between MDX-H210 C(max) and AUC and (i) MDX-H210 binding to peripheral blood monocytes and neutrophils, (ii) the peak plasma G-CSF, IL-6, IL-8 and TNFalpha concentrations, and (iii) the observed clinical toxicity. RESULTS: 23 patients (19F:4M; median age 51.5; range 25-72 y) with advanced HER-2/neu positive cancers (19 breast, three prostate and one lung) were studied. Plasma MDX-H210 concentrations over time, circulating numbers of monocytes and neutrophils, percent saturation of monocyte and neutrophil FcgammaRI, and plasma concentrations over time of G-CSF, IL-6, IL-8 and TNFalpha were measured and clinical toxicity monitored. The E(max) pharmacodynamic model best fitted the relationship of MDX-H210 C(max) and the maximum percent saturation of both monocytes (E(max)=74.6; EC(50)=0.9 microg/ml) and neutrophils (E(max)=66.2; EC(50)=2.3 microg/ml) on the first day of treatment. On the last day of treatment, day 19, these parameters were E(max)=57.0% and EC(50)=0.46 microg/ml for monocytes and E(max)=61.9% and EC(50)=0.26 microg/ml for neutrophils. No positive relationship was defined between the log MDX-H210 C(max) and the log peak plasma IL-6, G-CSF, TNF or IL-8 concentrations on day 1. On day 19 these plasma cytokine concentrations were undetectable post MDX-H210 therapy. There was no consistent relationship between MDX-H210 C(max) and the observed clinical toxicities. CONCLUSIONS: These data suggest that MDX-H210 C(max) and AUC could be related by the E(max) model to maximum percent FcgammaRI saturation on circulating monocytes and neutrophils in the patients studied. After day 1, the post MDX-H210 therapy cytokine response attenuated over time, consistent with desensitization. We did not find a relationship between log MDX-H210 C(max) and peak plasma cytokine concentrations or clinical toxicities.

Adult↗
PubMed2000

The phytophthora genome initiative database: informatics and analysis for distributed pathogenomic research.

The Phytophthora Genome Initiative (PGI) is a distributed collaboration to study the genome and evolution of a particularly destructive group of plant pathogenic oomycete, with the goal of understanding the mechanisms of infection and resistance. NCGR provides informatics support for the collaboration as well as a centralized data repository. In the pilot phase of the project, several investigators prepared Phytophthora infestans and Phytophthora sojae EST and Phytophthora sojae BAC libraries and sent them to another laboratory for sequencing. Data from sequencing reactions were transferred to NCGR for analysis and curation. An analysis pipeline transforms raw data by performing simple analyses (i.e., vector removal and similarity searching) that are stored and can be retrieved by investigators using a web browser. Here we describe the database and access tools, provide an overview of the data therein and outline future plans. This resource has provided a unique opportunity for the distributed, collaborative study of a genus from which relatively little sequence data are available. Results may lead to insight into how better to control these pathogens. The homepage of PGI can be accessed at http:www.ncgr.org/pgi, with database access through the database access hyperlink.

Databases, Factual↗
PubMed2000

Signal transduction cascades regulating fungal development and virulence.

Cellular differentiation, mating, and filamentous growth are regulated in many fungi by environmental and nutritional signals. For example, in response to nitrogen limitation, diploid cells of the yeast Saccharomyces cerevisiae undergo a dimorphic transition to filamentous growth referred to as pseudohyphal differentiation. Yeast filamentous growth is regulated, in part, by two conserved signal transduction cascades: a mitogen-activated protein kinase cascade and a G-protein regulated cyclic AMP signaling pathway. Related signaling cascades play an analogous role in regulating mating and virulence in the plant fungal pathogen Ustilago maydis and the human fungal pathogens Cryptococcus neoformans and Candida albicans. We review here studies on the signaling cascades that regulate development of these and other fungi. This analysis illustrates both how the model yeast S. cerevisiae can serve as a paradigm for signaling in other organisms and also how studies in other fungi provide insights into conserved signaling pathways that operate in many divergent organisms.

Calcineurin↗
PubMed1999

A flow cytometric method to estimate the precursor frequencies of cells proliferating in response to specific antigens.

Fluorescent dyes that stain cell membranes or cytoplasm and then partition between daughter cells at division have been used in conjunction with flow cytometry to measure the proliferation of cells. In this paper, using peripheral blood mononuclear cells responding to tetanus toxoid, we describe an extension of this dye methodology to calculate the precursor frequency of antigen-specific T-cells. With mathematical deconvolution of the fluorescence histograms providing information about the proportion of cells in each of the daughter generations, information can be derived about the precursor frequency of cells in the original population that responded to the specific stimulus. Data from a model system with different proportions of fixed and viable cells indicate that the flow method returns accurate values for precursor frequency. Based on the characteristics of flow cytometric data acquisition, it is estimated that the flow method could detect proliferation of cells that represented, before addition of the stimulus, approximately 1/10(5) of the population. When comparing results to those from the limiting dilution technique, the flow cytometric method returns values that indicate higher precursor frequencies. Possible reasons for this discrepancy are discussed. The flow cytometric method offers the advantage of simplicity as well as the additional ability to phenotype the responding cells and determine their rate of proliferation. The flow method may find use as a simple, routine assay in the fields of allergy, transplant rejection, and autoimmunity and for quantitating responses to vaccination and cancer immunotherapy.

Antigens↗
PubMed1998

The Genome Sequence DataBase (GSDB): improving data quality and data access.

In 1997 the primary focus of the Genome Sequence DataBase (GSDB; www. ncgr.org/gsdb ) located at the National Center for Genome Resources was to improve data quality and accessibility. Efforts to increase the quality of data within the database included two major projects; one to identify and remove all vector contamination from sequences in the database and one to create premier sequence sets (including both alignments and discontiguous sequences). Data accessibility was improved during the course of the last year in several ways. First, a graphical database sequence viewer was made available to researchers. Second, an update process was implemented for the web-based query tool, Maestro. Third, a web-based tool, Excerpt, was developed to retrieve selected regions of any sequence in the database. And lastly, a GSDB flatfile that contains annotation unique to GSDB (e.g., sequence analysis and alignment data) was developed. Additionally, the GSDB web site provides a tool for the detection of matrix attachment regions (MARs), which can be used to identify regions of high coding potential. The ultimate goal of this work is to make GSDB a more useful resource for genomic comparison studies and gene level studies by improving data quality and by providing data access capabilities that are consistent with the needs of both types of studies.

Base Sequence↗
PubMed1994

Selective modulation of IFN-gamma mRNA stability by IL-12/NKSF.

We investigated the role of IL-12 in regulating IL-2 and IFN-gamma production in primary culture of human T cells. Addition of neutralizing antiserum against the 40-kDa subunit of IL-12 to PHA-stimulated PBMC markedly reduced both IFN-gamma protein production and mRNA accumulation and stability. Moreover, concurrent treatment of partially purified T cells (> 90% CD3+) with PHA and rIL-12 selectively enhanced IFN-gamma mRNA stability and protein production, while IL-2 protein and mRNA levels were unaffected. These studies also show that IFN-gamma and IL-2 mRNA stability are temporally dissociated during the course of T cell activation, and we propose that this dissociation may be mediated through the production of IL-12. The effect of IL-12 on modulation of IFN-gamma mRNA turnover is not associated with detectable changes in either the levels or affinity of cytoplasmic RNA-binding proteins capable of recognizing AU-rich sequences in the 3'UTR of IFN-gamma mRNA.

Base Sequence↗
PubMed1991

The great pox.

Explore the source record for details and available documents.

Disease Outbreaks↗
PubMed1990

Regulation of human monocyte HLA-DR and CD4 antigen expression, and antigen presentation by 1,25-dihydroxyvitamin D3.

1,25-Dihydroxyvitamin D3 (1,25(OH)2-D) has been shown to be a macrophage-derived cytokine, capable of regulating myeloid differentiation and T-cell activation in vitro. Therefore, we examined the effects of 1,25(OH)2-D on the monocyte phenotype and function of human peripheral blood monocytes as an index of its biologic role at an inflammatory site. 1,25(OH)2-D treatment consistently and specifically reduced HLA-DR and CD4 expression by monocytes, while CD14 and class I HLA antigen expression were unaffected. Expression of Fc gamma R I-III on monocytes was variably modulated by 1,25(OH)2-D treatment, but no differences in antibody-dependent cell cytotoxicity (ADCC) were observed, measured using either ADCC or anti-Fc gamma R-antibody expressing hybridomas. In contrast, the ability of monocytes to induce antigen-dependent T-cell proliferation was markedly reduced by 1,25(OH)2-D pretreatment for as little as 6 hours. Addition of interleukin-1 (IL-1), IL-6, or indomethacin did not restore antigen-dependent T-cell proliferation, suggesting that this observation was not secondary to changes in IL-1, IL-6, or PGE2 production induced by 1,25(OH)2-D. These data suggest that 1,25(OH)2-D treatment specifically modulates human monocyte phenotype and function, altering HLA-DR antigen expression and antigen presentation, while leaving lytic function intact. These findings may be relevant to the immunobiologic role of 1,25(OH)2-D.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1989

Effect of social drinking on neuropsychological performance.

The effects of social drinking on neuropsychological function have been assessed in a group of healthy male volunteers. Subjects were divided into three groups according to their daily alcohol consumption: (1) 40 g or less (n = 93), (2) 41-80 g (n = 22), (3) 81-130 g (n = 16). Group 1 had been drinking at the present level for a mean of 12.6 years, group 2 for 16.9 years and group 3 for 15.1 years; the differences are not significant. There are no significant differences on any neuropsychological tests variables between groups 1 and 2. However, subjects in group 3 were found to perform at a significantly lower level than groups 1 and 2 on the Rey Auditory Verbal Learning Test, the Austin Maze, and the Little Man and Spatial Memory Tests of the Bexley Maudsley Automated Psychological Screening Test. The pattern of deficits found in heavy social drinkers is less severe but otherwise similar to that found in alcoholics.

Adult↗
PubMed1977

Hepatitis B antigen and antibody in a male homosexual population.

Sera from 600 male homosexual patients were tested for hepatitis B antigen (HBs Ag) and its antibody (HBs Ab). Thirty-one men (5-2%) were positive for HBs Ag. Testing for HBs Ab by immuno-osmoelectrophoresis 33 men (5-5%) were positive. However, sera of 85 patients negative for HBs Ab by routine methods were examined for HBs Ab by radioimmune assay. Thirty (35%) sera were found to be positive. No absolute correlation between the detection of HBs Ag, or previous history of hepatitis, jaundice, or current hepatitis was found. Similarly there was little correlation between presence of HBs Ab and this history. These observations suggest that the male homosexual population represents a pool of individuals within which the hepatitis B virus is readily transmitted, mainly as a subclinical infection although clinical hepatitis does occur in some patients. It is suggested that further work is necessary to determine whether the high antibody rate in male homosexuals is related more to sexual practice than to promiscuity.

Adolescent↗