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Biomedical subjects

T Hong

Publications and source records attributed to T Hong.

At least 55 records · Page 3Linked to original sources
PubMed1994

Expression and characterization of a fusion protein between the catalytic domain of poly(ADP-ribose) polymerase and the DNA binding domain of the glucocorticoid receptor.

A fusion protein comprising the DNA-binding region of the glucocorticoid receptor and the catalytic domain of poly(ADP-ribose) polymerase was constructed. This chimeric protein was expressed both in E. coli and in eukaryotic cells and was recognized by antibodies to both polymerase and the glucocorticoid receptor. Similar to polymerase, the chimera produced bona fide poly (ADP-ribose) polymers covalently bound to protein and was inhibited by 3-aminobenzamide. Like the authentic glucocorticoid receptor, the fusion protein formed a stable complex with DNA containing the glucocorticoid response element. In mammalian cells, the fusion protein significantly and specifically inhibited the ability of the glucocorticoid receptor to stimulate a reporter construct. These results indicate that polymerase activity can be targeted to specific DNA sequences and modulate gene expression.

Adenosine Diphosphate Ribose↗
PubMed1994

Transcription, translation, and cellular localization of PDV-E66: a structural protein of the PDV envelope of Autographa californica nuclear polyhedrosis virus.

A late gene encoding a 66-kDa structural protein of Autographa californica nuclear polyhedrosis virus was mapped and sequenced (26.9-29.7 MU). Transcription initiates from two conserved TAAG motifs (-15 and -37) with transcripts detected from 12 to 72 hr pi. The protein is detected in infected Spodoptera frugiperda (Sf9) cells from 24 to 72 hr pi. Western-blot and immunoelectron microscopic data identify this protein as specific for the polyhedra-derived virus (PDV) envelope. This protein has been named PDV-E66 to identify its viral origin, envelope location, and apparent molecular weight. In addition to being a structural protein of the PDV envelope, PDV-E66 is enriched in foci of microvesicles in the nuclei of infected Sf9 cells.

Amino Acid Sequence↗
PubMed1993

Human immunodeficiency virus type 1 DNA integration: fine structure target analysis using synthetic oligonucleotides.

The target specificity of DNA strand transfer mediated by human immunodeficiency virus type 1 integrase was examined in vitro with synthetic oligonucleotides. Although insertion occurred at most locations in the target, some sites were preferred over others by at least 15-fold. Changing the nucleotide sequence of the target changed the distribution of preferred sites in complex ways, some of which included changes in target preference distant from the sequence alteration. Alignment of target sequences revealed that adenosine is preferred adjacent to the insertion site. Strand transfer occurred to within 2 nucleotides of the 3' end and to within 3 nucleotides of the 5' end of the target. This suggests that only 2 or 3 nucleotides flanking the target site are required for integration; such restricted contact with target DNA would allow integrase to insert the two ends of viral DNA into two closely spaced sites in host DNA, consistent with the concerted in vivo integration reaction that generates a 5-bp target duplication.

Base Sequence↗
PubMed1993

Basic mycology underscoring medically important fungi.

This article details the basic mycologic features of yeast and mold-like fungi causing infections in humans. Concordant with the mycologic attributes delineating species identification, the pathogenic potential of mycotic agents is discussed with particular reference to intrinsic fungal virulence factors (e.g., exoenzymes) and host factors (e.g., neutrophil function, underlying disease) predisposing to colonization and infection.

Fungi↗
PubMed1992

Sequence, genomic organization of the EcoRI-A fragment of Autographa californica nuclear polyhedrosis virus, and identification of a viral-encoded protein resembling the outer capsid protein VP8 of rotavirus.

We present the sequence and genomic organization of the EcoRI-A fragment of the Autographa californica multicapsid nuclear polyhedrosis virus, which represents 11% of the AcMNPV genome. Fifteen putative open reading frames and their respective amino acid sequences are described. One open reading frame is similar to the VP8 protein of rotavirus.

Amino Acid Sequence↗
PubMed1992

[Hypolipodemic action of zhikeqing].

Zhikeqing is a compound prescription of Chinese herbs. It has been proved shown to possess an obvious effect on lipid and lipoprotein cholesterol contents in the serum of hyperlipidemic mice or rats.

Animals↗
PubMed1991

Circular DNA of human immunodeficiency virus: analysis of circle junction nucleotide sequences.

During infection of cells by retroviruses, some of the nonintegrated viral DNA can be found as a circular form containing two tandem, directly repeated long terminal repeats. The nucleotide sequence at the point where the long terminal repeats join (the circle junction) can be used to deduce the terminal nucleotides of the linear form of the viral DNA. Comparison of the termini of linear viral DNA with sequences at the junctions between the integrated provirus and the host chromosome has revealed that for most retroviruses 2 bp are removed from each end of the linear viral DNA during integration. For human immunodeficiency virus type 1 (HIV-1), however, sequence considerations involving primer-binding sites had suggested that only 1 bp is removed during integration. We obtained the nucleotide sequences at the ends of HIV-1 DNA by using the polymerase chain reaction to amplify fragments corresponding to the HIV-1 circle junction. Of 17 clones containing amplified sequences, 10 had identical circle junctions that contained an additional 4 bp (GTAC) relative to the integrated provirus. This indicates that, as for other retroviruses, 2 bp are removed from each end of the linear HIV-1 viral DNA during integration. The remaining seven isolates contained insertions or deletions at the circle junction.

Base Sequence↗
PubMed1990

[Histological and biochemical studies of the uterus of ovariectomized gilts during the first two months of pregnancy after different hormone substitutions. 4. Effect of the conceptus on the activities of alkaline and acid phosphatase and the concentration of glycogen in the uterus during different supplies of progesterone and norgestrel].

Forty-five ovariectomised gilts in early gravidity received injections of progesterone doses between 120 mg and 40 mg as well as 250 micrograms/die of oestradiol-benzoate and oral application of 12 mg/die of norgestrel, the latter being administered in addition to the 40 mg dose of progesterone. The animals were killed between the 20th and 24th or on the 35th days of gravidity, before endometrial activities were determined of alkaline and acid phosphatases at various points of the uterus (centre and sides of ampullae and in-between ampullae). Under conditions of sufficient progesterone supply (120 mg/die and 100 mg/die), endometrial activities of both alkaline and acid phosphatases in the centre of ampullae were found to be higher than those in-between them. Activities were lower with inadequate progesterone supply (40 mg/die), and differences between points of sampling were less strongly pronounced for alkaline phosphatase. Endometrial glycogen concentrations in the centre of ampullae were lower than those in-between. Values in response to inadequate progesterone administration were lower than those following sufficient supply. With regard to glycogen concentrations, differences between points of sampling in the myometrium were below those in the endometrium.

Animals↗
PubMed1990

[The physiologic disposition and pharmacokinetics of guaiacol acetylsalicylate in rats].

Guaiacol acetylsalicylate (GASL) has been shown to possess significant anti-inflammatory, antipyretic and expectorant activities and has been used clinically in chronic bronchitis with fairly good results. In the present work, the absorption, distribution and excretion of metabolites of the drug were studied in rats using quantitative TLC scanning technique. GASL was shown to be unstable in rat gastrointestinal tract and guaiacol salicylate (GSLT) and salicylic acid (SLA) were found in plasma. The plasma SLA concentration-time curve obtained after oral administration of GASL to rats was shown to fit a one compartment open model with the following pharmacokinetic parameters: T1/2ka = 1.25 h, T1/2ke = 3.28 h, ka = 0.5554/h, ke = 0.2111/h, Tmax = 3.02 h, Cmax = 331.46 micrograms/ml, AUC = 2832.93 micrograms/ml.h The SLA concentration was found to be high in muscle, moderate in spleen, testicle, kidney, lung, plasma, heart and liver and low in brain. The GSLT concentration was found to be low in plasma and organs. Within 24 h following ig administration of GASL the total SLA excreted in urine and feces was 10.9 and 0.41 of the GASL dose, respectively.

Animals↗
PubMed1990

[Histologic and biochemical studies of the uteri of ovariectomized gilts during the first two months of pregnancy after different hormone substitutions. 2. Effects of reducing the progesterone dosage on the survival rate of embryos and the structure of the placenta and the influence of oral administration of norgestrel].

Studies were conducted into ovariectomised gilts in early gravidity, with the view to finding out if reduction of daily progesterone doses had an impact upon embryo survival rate and on the structure of the placenta and if experimentally induced progesterone deficit could be offset by oral administration of norgestrel, a synthetic progestagen. Embryo survival were found to drop from 80 to 26.1 percent in response to reduced progesterone dosage from 120 mg to 40 mg, average numbers of living embryos per animal being 9.6 or 3.0. Oral administration of 12 mg of norgestrel, in addition to injection of 40 mg of progesterone, enhanced the survival rate to 64.6 percent, the average number of living embryos coming to 8.9. Reduction of progesterone doses compared to animals with sufficient progesterone supply. Depressed the beginning decrease of the thickness endometrium and surface epithelium oedematisation of the endometrial stroma was mitigated, and subepithelial hyperaemia disappeared altogether. The secretory activity of uterine glands declined, and so did the endometrial activities of acid and alkaline phosphatases. Administration of norgestrel proved helpful in substantive removal of manifestations observed in the progesterone deficit group.

Administration, Oral↗
PubMed1990

[Histologic and biochemical studies of the uteri of ovariectomized gilts during the first two months of pregnancy after different hormone substitutions. 3. Local effects of the conceptus on the structure of the placenta and its modification by different progesterone and norgestrel administration].

Optical light microscopy was used in investigations of ovariectomised gravid gilts to which progesterone doses between 120 mg and 40 mg as well as 250 micrograms of oestradiol benzoate had been daily applied to preserve gravidity, with 12 mg of norgestrel being additionally administered to some of them. These investigations were conducted for the purpose of studying locally delimited effects of conception on the placental structure. Uterus tissue was sampled from living and dead embryos (centre and sides of ampullae) as well as from uterus regions free of foetal membranes (in-between ampullae). With adequate progesterone supply, embryos were shown to clearly affect the endometrial structures. Endometrium in the centre of ampullae, with living embryos, was lower than at points without embryos. Surface epithelium was flattened, and endometrial stroma was more strongly oedematised. Strongly pronounced hyperaemia occurred to subepithelial stroma in the centre of ampullae, and uterine glandular function was unambiguously stimulated. These embryo-triggered effects were much less or no longer detectable at all under conditions of inadequate progesterone supply (40 mg/die). Administration of 12 mg of norgestrel, in addition to 40 mg/die of progesterone, enabled embryos to exercise gravidity-specific influence upon the endometrium, as in cases of sufficient progesterone supply.

Animals↗