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Full-Text Articles in Medicine and Health Sciences

The Landmark Citation Method: Analysis Of A Citation Pattern As A Collection Assessment Method, Catherine B. Soehner, S Tanner Wray, Daniel T. Richards Dec 1991

The Landmark Citation Method: Analysis Of A Citation Pattern As A Collection Assessment Method, Catherine B. Soehner, S Tanner Wray, Daniel T. Richards

Dartmouth Scholarship

The landmark citation method is a new collection assessment method based on the citation record of a single landmark article. This citation record is developed by identifying sources which cite the landmark article. A bibliography, extracted from the citation record, is then used to complete an assessment of the collection. This method was developed and used to assess the biotechnology collection of the National Library of Medicine. The information gained from this study, in addition to demonstrating the technique, also provided insight into the evolution of the biotechnology literature.


The Ability Of Simian Virus 40 Large T Antigen To Immortalize Primary Mouse Embryo Fibroblasts Cosegregates With Its Ability To Bind To P53., Jiyue Y. Zhu, Marina Abate, Philip W. Rice, Charles N. Cole Dec 1991

The Ability Of Simian Virus 40 Large T Antigen To Immortalize Primary Mouse Embryo Fibroblasts Cosegregates With Its Ability To Bind To P53., Jiyue Y. Zhu, Marina Abate, Philip W. Rice, Charles N. Cole

Dartmouth Scholarship

The large T antigen encoded by simian virus 40 (SV40) plays essential roles in the infection of permissive cells, leading to production of progeny virions, and in the infection of nonpermissive cells, leading to malignant transformation. Primary mouse embryo fibroblasts (MEFs) are nonpermissive for SV40, and infection by wild-type SV40 leads to immortalization and transformation of a small percentage of infected cells. We examined the ability of an extensive set of mutants whose lesions affect SV40 large T antigen to immortalize MEFs. We found that immortalization activity was retained by all mutants whose lesions are located upstream of codon 346. …


A Polymerase Chain Reaction-Based Method To Detect Cisplatin Adducts In Specific Genes, M M. Jennerwein, A Eastman Nov 1991

A Polymerase Chain Reaction-Based Method To Detect Cisplatin Adducts In Specific Genes, M M. Jennerwein, A Eastman

Dartmouth Scholarship

Every bulky lesion in DNA can potentially inhibit the Taq DNA polymerase and thereby decrease the amplification produced in the polymerase chain reaction. We investigated the feasibility of using this inhibition to quantify DNA lesions produced by the anticancer drug cisplatin. Products were detected by electrophoresis followed by ethidium bromide staining. Quantitation was obtained by including [32P]dCTP in the amplification reaction and subsequently assessing the incorporated radioactivity. Hamster genomic DNA was platinated in vitro to defined levels and amplified with primers that produce either a 150, 750 or 2,000 base pair fragment. The degree of inhibition of PCR …


Fc Receptors For Igg (Fc Gamma Rs) On Human Monocytes And Macrophages Are Not Infectivity Receptors For Human Immunodeficiency Virus Type 1 (Hiv-1): Studies Using Bispecific Antibodies To Target Hiv-1 To Various Myeloid Cell Surface Molecules, Including The Fc Gamma R., R I. Connor, N B. Dinces, A L. Howell, J L. Romet-Lemonne, J L. Pasquali, M W. Fanger Nov 1991

Fc Receptors For Igg (Fc Gamma Rs) On Human Monocytes And Macrophages Are Not Infectivity Receptors For Human Immunodeficiency Virus Type 1 (Hiv-1): Studies Using Bispecific Antibodies To Target Hiv-1 To Various Myeloid Cell Surface Molecules, Including The Fc Gamma R., R I. Connor, N B. Dinces, A L. Howell, J L. Romet-Lemonne, J L. Pasquali, M W. Fanger

Dartmouth Scholarship

Fc gamma Rs (Fc gamma RI, Fc gamma RII, and Fc gamma RIII) are highly expressed on human mononuclear phagocytes and function in the clearance of immune complexes and opsonized pathogens. We have examined the role of Fc gamma R in mediating antibody-dependent clearance of HIV-1 by human monocytes and monocyte-derived macrophages by using bispecific antibodies (BsAbs) to independently target the virus to Fc gamma RI, Fc gamma RII, or Fc gamma RIII. Virus production was markedly reduced in monocytes cultured with strain HIV-1IIIB opsonized with BsAbs that target the virus to either Fc gamma RI or Fc gamma RII …


Translocation Of The Glucose Transporter Glut4 In Cardiac Myocytes Of The Rat., Jan W. Slot, Hans J. Geuze, Sander Gigengack, David E. James, Gustav E. Lienhard Sep 1991

Translocation Of The Glucose Transporter Glut4 In Cardiac Myocytes Of The Rat., Jan W. Slot, Hans J. Geuze, Sander Gigengack, David E. James, Gustav E. Lienhard

Dartmouth Scholarship

The insulin-regulated glucose transporter GLUT4 was immunolocalized in rat cardiac muscle under conditions of basal and stimulated glucose uptake, achieved by fasting and a combined exercise/insulin stimulus, respectively. In basal myocytes there was very little (less than 1%) GLUT4 in the different domains of the plasma membrane (sarcolemma, intercalated disk, and transverse tubular system). GLUT4 was localized in small tubulo-vesicular elements that occur predominantly near the sarcolemma and the transverse tubular system and in the trans-Golgi region. Upon stimulation approximately 42% of GLUT4 was found in the plasma membrane. Each domain of the plasma membrane contributed equally to this effect. …


Mapping The Transcriptional Transactivation Function Of Simian Virus 40 Large T Antigen., Jiyue Y. Zhu, Philip W. Rice, Michele Chamberlain, Charles N. Cole Jun 1991

Mapping The Transcriptional Transactivation Function Of Simian Virus 40 Large T Antigen., Jiyue Y. Zhu, Philip W. Rice, Michele Chamberlain, Charles N. Cole

Dartmouth Scholarship

T antigen is able to transactivate gene expression from the simian virus 40 (SV40) late promoter and from several other viral and cellular promoters. Neither the mechanisms of transactivation by T antigen nor the regions of T antigen required for this activity have been determined. To address the latter point, we have measured the ability of a set of SV40 large T antigen mutants to stimulate gene expression in CV-1 monkey kidney cells from the SV40 late promoter and Rous sarcoma virus (RSV) long terminal repeat (LTR) promoter. Transactivation, although reduced, was retained by an N-terminal 138-amino-acid fragment of T …


Effect Of Delays In Processing On The Survival Of Mycobacterium Avium-M. Intracellulare In The Isolator Blood Culture System., C. Fordham Von Reyn, Stephen Hennigan, Sandra Niemczyk, Nicholas J. Jacobs Jun 1991

Effect Of Delays In Processing On The Survival Of Mycobacterium Avium-M. Intracellulare In The Isolator Blood Culture System., C. Fordham Von Reyn, Stephen Hennigan, Sandra Niemczyk, Nicholas J. Jacobs

Dartmouth Scholarship

Concentrations of Mycobacterium avium-M. intracellulare ranging from 10(-1) to 10(3) CFU/ml were added to blood, placed in Isolator tubes, and held at room temperature for intervals ranging from 4 h to 56 days before being processed (centrifugation and culture on Middlebrook 7H10 agar). At all concentrations tested, M. avium-M. intracellulare was recovered after hold times ranging from 4 h to 7 days; the number of final CFU actually increased progressively for hold times of 8 h or more. Hold times of up to 7 days did not increase the time from processing to the first appearance of visible colonies. At …


Evidence For Attenuation Of Myo-Inositol Uptake, Phosphoinositide Turnover And Inositol Phosphate Production In Aortic Vasculature Of Rats During Pregnancy, Kirk P. Conrad, Susan A. Barrera, Peter A. Friedman, Vicki M. Schmidt May 1991

Evidence For Attenuation Of Myo-Inositol Uptake, Phosphoinositide Turnover And Inositol Phosphate Production In Aortic Vasculature Of Rats During Pregnancy, Kirk P. Conrad, Susan A. Barrera, Peter A. Friedman, Vicki M. Schmidt

Dartmouth Scholarship

We postulated that vascular phosphoinositide metabolism is attenuated during pregnancy, and thereby could contribute to maternal vasodilation and reduced vascular reactivity. The basal rate of incorporation of [3H]myo-inositol and [3H]glycerol into phosphoinositides of aortae from pregnant rats in vitro was significantly reduced, when compared with vessels from virgin animals. After injection of [3H]myo-inositol intravenously into chronically instrumented conscious pregnant and virgin rats, the incorporation of the label by phosphatidylinositol was 66 +/- 4% less in aortae of gravid versus virgin animals (P less than 0.001), despite comparable plasma concentrations of radioactivity. Fold stimulation of total [3H]inositol phosphates by arginine vasopressin, …


Reaction Of Chromium(Vi) With Glutathione Or With Hydrogen Peroxide: Identification Of Reactive Intermediates And Their Role In Chromium(Vi)-Induced Dna Damage, J Aiyar, H Berkovits, R Floyd, K Wetterhahn May 1991

Reaction Of Chromium(Vi) With Glutathione Or With Hydrogen Peroxide: Identification Of Reactive Intermediates And Their Role In Chromium(Vi)-Induced Dna Damage, J Aiyar, H Berkovits, R Floyd, K Wetterhahn

Dartmouth Scholarship

The types of reactive intermediates generated upon reduction of chromium(VI) by glutathione or hydrogen peroxide and the resulting DNA damage have been determined. In vitro, reaction of chromium(VI) with glutathione led to formation of two chromium(V) complexes and the glutathione thiyl radical. When chromium(VI) was reacted with DNA in the presence of glutathione, chromium-DNA adducts were obtained, with no DNA strand breakage. The level of chromium-DNA adduct formation correlated with chromium(V) formation. Reaction of chromium(VI) with hydrogen peroxide led to formation of hydroxyl radical. No chromium(V) was detectable at 24 degrees C (297 K); however, low levels of the tetraperoxochromium(V) …


Interleukin-2-Triggered Raf-1 Expression, Phosphorylation, And Associated Kinase Activity Increase Through G1 And S In Cd3-Stimulated Primary Human T Cells., Antanina Zmuidzinas, Harvey J. Mamon, Thomas M. Roberts, Kendall A. Smith May 1991

Interleukin-2-Triggered Raf-1 Expression, Phosphorylation, And Associated Kinase Activity Increase Through G1 And S In Cd3-Stimulated Primary Human T Cells., Antanina Zmuidzinas, Harvey J. Mamon, Thomas M. Roberts, Kendall A. Smith

Dartmouth Scholarship

To gain further insight into the role of Raf-1 in normal cell growth, c-raf-1 mRNA expression, Raf-1 protein production, and Raf-1-associated kinase activity in normal human T cells were analyzed. In contrast to the constitutive expression of Raf-1 in continuously proliferating cell lines, c-raf-1 mRNA and Raf-1 protein levels were barely detectable in freshly isolated G0 T lymphocytes. Previous work with fibroblasts has suggested that Raf-1 plays a signaling role in the G0-G1 phase transition. In T cells, triggering via the T-cell antigen receptor (TCR)-CD3 complex (TCR/CD3) resulted in an approximately fourfold increase in c-raf-1 mRNA. In addition, the promotion …


Acquired Cisplatin Resistance In Human Ovarian Cancer Cells Is Associated With Enhanced Repair Of Cisplatin-Dna Lesions And Reduced Drug Accumulation., Ricardo J. Parker, Alan Eastman, Frieda Bostick-Bruton, Eddie Reed Mar 1991

Acquired Cisplatin Resistance In Human Ovarian Cancer Cells Is Associated With Enhanced Repair Of Cisplatin-Dna Lesions And Reduced Drug Accumulation., Ricardo J. Parker, Alan Eastman, Frieda Bostick-Bruton, Eddie Reed

Dartmouth Scholarship

Studies were undertaken to investigate acquired resistance to cisplatin in human ovarian cancer cells. The cell lines A2780 and A2780/CP70 were studied to assess their respective characteristics of drug accumulation and efflux, cytosolic inactivation of drug, and DNA repair. All experiments were performed using 1-h drug exposures. The A2780/CP70 cell line was 13-fold more resistant to cisplatin than A2780 cells. When studied at their respective IC50 doses, drug accumulation rates were similar for the two cell lines. However, the resistant cell line was twofold more efficient at effluxing drug, which was associated with reduced total drug accumulation for equivalent micromolar …


Interleukin-1 Or Phorbol Induction Of The Stromelysin Promoter Requires An Element That Cooperates With Ap-1., Karen Sirum-Connolly, Constance E. Brinckerhoff Jan 1991

Interleukin-1 Or Phorbol Induction Of The Stromelysin Promoter Requires An Element That Cooperates With Ap-1., Karen Sirum-Connolly, Constance E. Brinckerhoff

Dartmouth Scholarship

Interieukin-1, a mediator of inflammation, or tumor promoting phorbol esters induce transcription of stromelysin, a metalloproteinase that degrades extracellular matrix molecules and that is overexpressed in diseases such as rheumatoid arthritis. Sequences required for induction of transcription of the human stromelysin promoter are contained on a 46 base pair fragment. This fragment contains a sequence with a high degree of similarity to the binding site for the transcription factor activator protein-1 (AP-1) and indeed, the AP-1 sequence of this fragment is necessary but not sufficient for the maximal response to phorbol 12-myristate 13-acetate (phorbol) or interleukin-1. Maximal induction requires functional …


Neurospora Crassa Clock-Controlled Genes Are Regulated At The Level Of Transcription., Jennifer J. Loros, Jay C. Dunlap Jan 1991

Neurospora Crassa Clock-Controlled Genes Are Regulated At The Level Of Transcription., Jennifer J. Loros, Jay C. Dunlap

Dartmouth Scholarship

Although an extensive number of biological processes are under the daily control of the circadian biological clock, little is known about how the clock maintains its regulatory networks within a cell. An important aspect of this temporal control is the daily control of gene expression. Previously we identified two morning-specific genes that are regulated by the clock through daily control of gene expression (J. Loros, S. Denome, and J.C. Dunlap, Science 243:385-388, 1989). We have now introduced a method for transcriptional analysis in Neurospora crassa and used this nuclear run-on procedure to show that regulation of mRNA abundance for these …