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D B Carter

Publications and source records attributed to D B Carter.

At least 73 records · Page 4Linked to original sources
PubMed1990

Secretion of interleukin-6 (IL-6) by human monocytes stimulated by muramyl dipeptide and tumour necrosis factor alpha.

We studied IL-6 gene expression in human monocytes stimulated by muramyl dipeptide (MDP), a synthetic immunomodulator derived from mycobacterial cell walls. In control monocytes, two IL-6 transcripts of 3.4 kb and 1.6 kb were easily detected at 2.5 hr of culture and remained stable until 18 hr. In MDP-treated monocytes, three IL-6 RNA species displayed different kinetics of accumulation: a 3.4 kb RNA whose expression already reached its maximum after 2.5 hr exposure to MDP; a 1.6 kb RNA whose expression peaked at 5 hr; and a new RNA species of 1.4 kb which was transiently induced in early time of cell stimulation. TNF-alpha co-operated with MDP to increase IL-6 gene expression and secretion of biological active protein (measured by the hybridoma plasmacytoma growth factor assay). MDP exhibits a broad spectrum of immunomodulation properties such as adjuvant activity, enhancement of macrophage cytotoxicity against tumour and induction of non-specific resistance to intracellular agents. The results reported here suggest that these properties might be linked to the stimulation by MDP of genes coding for key cytokines such as IL-6, TNF and IL-1.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1989

Platelet-derived growth factor induces interleukin-1 receptor gene expression in Balb/c 3T3 fibroblasts.

Our previous studies have demonstrated that platelet-derived growth factor (PDGF) modulated cellular responses to interleukin-1 (IL-1). In this communication, we show that PDGF regulates expression of IL-1 receptor (IL-1 R) gene. Treatment of quiescent cultures of Balb/c 3T3 fibroblasts with PDGF produced 20-30-fold stimulation of IL-1 R mRNA with a concomitant increase in cell surface 125I-binding. IL-1 R mRNA accumulation occurred after an initial lag period and with a time course preceding the increase in 125I-IL-1 binding to cells. Induction of IL-1 R mRNA was blocked by inhibitors of protein synthesis, suggesting that a product of a gene expressed immediately after PDGF addition is required for IL-1 R gene expression. These latter data provide evidence for an ordered sequence of expression of PDGF-inducible "immediate early" gene(s) and IL-1 R gene. These results suggest that in connective tissues, PDGF may be an important determinant in initiating and maintaining cellular responses to IL-1. Such responses may have important consequences in the actions of IL-1 under normal and pathological conditions such as arthritis and atherosclerosis.

Animals↗
PubMed1988

Crystallization of purified recombinant human interleukin-1 beta.

The gene for human interleukin-1 beta was cloned from SK-hep-1 hepatoma cellular RNA and expressed at high levels in Escherichia coli both as the naturally processed form (rIL-1 beta) and as a variant with an additional sequence of three amino acids on the N-terminus (rIL-1 beta +). Expressed protein was purified to homogeneity by a sequence of steps, which included low pH incubation, adsorption and desorption from Procion Red Sepharose, sizing on a Superose 12 fast-performance liquid chromatography (FPLC) column, and anion exchange chromatography on QAE Sepharose. The final step provided a biologically active protein that migrates on two-dimensional (2-D) gels as a single spot with a pI of 6.7 +/- 0.2 and a molecular mass of 17,500 daltons. Concentrated solutions of rIL-1 beta have produced crystals by ammonium sulfate precipitation. The crystals are tetragonal, show the symmetry of space group P4(1) or its enantiomer, have lattice constants of a = 58.46 (1) and c = 77.02 (3) A, and scatter to at least 2 A resolution. A structure determination based on these crystals is under way.

Amino Acid Sequence↗
PubMed1988

Structure of the androgen dependent SVS VI protein as derived from cDNA.

The 11S poly(A+)RNA from rat seminal vesicle was cloned. By hybrid selection of clones reacting to the low molecular weight region of the 11S peak, a clone containing a new seminal vesicle cDNA sequence called SVS VI was isolated. The DNA sequence of two overlapping cDNAs (pSV24 and pSV33) is presented. The sequence of SVS VI was compared to the previously isolated SVS IV and SVS V cDNAS. Dot hybridization showed that SVS VI is androgen responsive after giving testosterone to castrated rats. The hydrophilicity was analyzed using standard Bionet procedures. All three proteins are extremely variable, rich in alpha-helix and very water soluble. The computer predicted hydrophilicity is compared for SVS VI, V and IV. A small region in the 3'-non-coding area of SVS VI has high similarity to a region in SVS IV mRNA.

Amino Acid Sequence↗
PubMed1987

Enhanced interleukin-1 production by human monocyte cell lines following treatment with 5-azacytidine.

Recent studies suggest that DNA modification, such as methylation of specific bases or substitution of altered bases, can play an important role in the control of eukaryotic gene expression. We chose to examine the effects of two DNA modifying agents, 5-azacytidine (AZA) and 5-bromodeoxyuridine (BUdR), on interleukin-1 (IL-1) gene expression in the human monocyte cell lines THP-1 and U937.1. THP-1 produced IL-1 upon stimulation with lipopolysaccharide (LPS), whereas U937.1 did not. Following treatment with AZA, U937.1 cells could be induced to produce IL-1 beta mRNA and release IL-1, but only if a stimulus such as LPS was present. In addition, the level of IL-1 beta mRNA produced and IL-1 released by THP-1 cells after induction could be doubled by treatment with AZA. In contrast, we were unable to alter IL-1 production by treatment of cells with BUdR in the absence or presence of inducers. These results suggest that the production of IL-1 may be, in part, regulated by methylation of DNA.

Azacitidine↗
PubMed1985

The antigenic relatedness of proteins from human and simian prostate fluid.

Two-dimensional electrophoretic analysis of human prostate fluid reveals an abundant protein migrating to a molecular weight of 15 kD and an isoelectric point of 5.5. Polyclonal antibodies were raised specifically to microgram quantities of electrophoresed, excised, and eluted PSP15 (prostate secretory protein). Western immunoblot analysis using these antibodies showed they not only react to PSP15, but cross-react with simian prostate and human seminal fluid proteins of similar molecular weights. Two-dimensional gel immunoblots strongly suggest that the seminal protein and PSP15 are the same, thereby providing a more accessible source of the protein. The antibody to the human PSP15 cross-reacted with neither prostate fluid from the ventral lobe of the rat prostate nor the prostate fluid from the beagle dog.

Animals↗
PubMed1984

Molecular differentiation of the mouse genital tract: altered protein synthesis following prenatal exposure to diethylstilbestrol.

Exposure in utero to the synthetic estrogen diethylstilbestrol (DES) has been associated with the subsequent development of reproductive tract lesions in both women and experimental animals. Using the techniques of organ culture and two-dimensional (2-D) gel electrophoresis, the effects of DES on protein synthetic patterns were studied during fetal and neonatal development of the CD-1 mouse. The protein patterns, analyzed by comparing 2-D fluorograms after [35S] methionine incorporation at different developmental stages, were correlated with the histology at the same age. Several qualitative and quantitative changes in protein synthesis were observed after prenatal DES exposure. A protein, apparent by Day 14 of gestation, with molecular weight approximately 70,000 and pI of 5.8, was observed to be greatly diminished in all reproductive tract tissues exposed to DES during prenatal development. This alteration, induced in utero, persists through the early postnatal differentiation of the genital tract (17 days old). This protein may provide an early marker for alterations in normal reproductive tract function.

Animals↗
PubMed1983

Recombinant DNA strategies in genetic neurological diseases.

The application of recombinant DNA techniques applied to the study of genetic neurological diseases will play a major role in the practice of neurology in upcoming years. Strategies are now available to develop useful and relatively simple biochemical diagnostic tests for heterozygous individuals with diseases inherited as autosomal dominant traits. In addition, molecular genetic methods will lead to the delineation of the genomic mutations responsible for these diseases. This review will update the current status of research in several neurological genetic diseases including myotonic muscular dystrophy, Huntington's disease, Charcot-Marie-Tooth disease and Duchenne muscular dystrophy (X-linked). An introduction and overview of the methodology is provided. Specific research strategies including random screening of libraries, chromosome walking, messenger RNA selection, and messenger RNA translation are described. These strategies are designed to provide heterozygote identification, prenatal diagnosis and gestational management, the development of rational therapies, and the understanding of the molecular basis of disease expression.

Charcot-Marie-Tooth Disease↗
PubMed1983

Developmental aspects of androgen-dependent mRNA from rat ventral prostate using cloned cDNA.

The androgen-dependence of two mRNAs from rat ventral prostate coding for a 20 000 and an 11 000 dalton translation product has been investigated using complementary DNA cloned in the bacterial plasmid PBR322. One of the cloned insert DNAs from a recombinant plasmid, C-27, arrests the in vitro translation of C2 (Peeters et al. (1980) J. Biol. Chem. 255, 7017-7023). The other cloned insert DNA arrests the translation of a glycoprotein 20 000 daltons in size, with unknown function. The quantities of mRNA coding for the 20 000 and 11 000 dalton translation product were determined by hybridization of 32P-labeled inserts to filter-bound total RNA or poly(A+)-mRNA. Castration caused a decline in both mRNAs of 250-fold over 8 days. Stimulation with androgen of 5-week castrates restored the mRNA levels to 17% of intact for the 20 000 dalton translation product and 31% of intact for the 11 000 dalton translation product. The quantity of the two mRNAs found in the lateral poly(A+)-mRNA was about 1/10 that of the ventral level and the mRNAs were not detectable in the dorsal prostate, seminal vesicle or human prostate poly(A+)-mRNA populations. RNA from the ventral prostates of animals 10-21 days old contained mature levels of complementary sequences, suggesting a form of developmental posttranscriptional regulation for synthesis of the polypeptides which are not synthesized in mature quantities at this stage of development (Heyns et al. (1978) Endocrinology 103, 1090-1095; Kistler et al. (1981) Proc. Natl. Acad. Sci. (U.S.A.) 78, 737-741).

Androgen-Binding Protein↗
PubMed1982

High resolution analysis of human prostatic fluid by two-dimensional electrophoresis.

High-resolution two-dimensional electrophoresis has been used to resolve the major protein components of human prostatic fluid. Samples taken from individuals ranging in age from 19 to 74 years show ten major proteins that are consistently present in the fluids examined. Seven major proteins appear to have age-dependent patterns of synthesis and accumulation in the prostatic fluid. A major protein in the human fluid has electrophoretic properties similar to the glycosylated component of the rat ventral prostate secretory protein known as prostatic binding protein, prostatein, or estramustine binding protein. The isoelectric point/molecular weight of the human protein is 6.0/17,000 compared with 5.6/13,000 for the rat protein. Protein patterns from benign prostatic hyperplasia cases were not dramatically different from the normal patterns.

Adult↗
PubMed1982

Molecular differentiation of the mouse genital tract: protein synthesis in fetal and immature female reproductive tract.

Using two-dimensional gel electrophoresis, approximately 75% of the 192 proteins detected in the fetal mouse genital tract are also detected on fluorograms of immature tissue. There is a progressive increase in the number of qualitatively different proteins synthesized from Day 14 fetal genital tissue to the 17-day-old immature uterus and vagina. Seventy-eight percent of the 180 proteins detectable on fluorograms of proteins having isoelectric points between 4 and 7, and proteins synthesized in the immature female genital tracts, were also detected in fluorograms of fetal tissues. Four of the 12 new proteins appear to be specific to the immature vagina; the remaining 8, specific to the immature uterus.

Animals↗
PubMed1981

Molecular differentiation of the mouse genital tract: serum-free organ culture system for morphological and biochemical correlations.

This report describes a serum-free system for studying the fetal mouse genital tract in organ culture. Using the techniques of isoelectric focusing and gel electrophoresis of polypeptides synthesized by the organ explant in culture, the biochemical integrity of as little as 1 to 2 mg of this tissue was determined during the period of culture. Thus, differentiation of the fetal genital tissue in organ culture can be assessed by both morphological and biochemical criteria.

Animals↗
PubMed1981

Uterine proteins influenced by estrogen exposure. Analysis by two-dimensional gel electrophoresis.

Two-dimensional gel electrophoresis has been utilized as a technique to investigate uterine protein patterns and protein distribution after estrogen administration. A combined in vivo stimulation, in vitro labeling technique was devised to investigate these questions. Animals were first primed in vivo with estrogen for 2 h to activate the normal early response to hormone and to stimulate protein synthesis. Tissue was removed and protein labeling occurred for 4 h with [35S]methionine. Tissue was then re-exposed in vitro to either estrogen or saline for an additional 1 h. Subfractionation of the uterine tissue and analysis of labeled proteins by two-dimensional gel electrophoresis has indicated the disappearance of some proteins from the cytoplasmic compartment and the appearance of other proteins in the nuclear fraction of estrogen-exposed samples. These findings suggest that in the mouse uterus, estrogen influences protein synthesis and also a redistribution of these proteins into various cellular fractions where they may act to elicit estrogen action.

Animals↗
PubMed1981

Effect of testosterone propionate on protein synthesis by two-dimensional electrophoresis in rat ventral prostate.

Two-dimensional polyacrylamide gel electrophoresis has been used to map the pattern of protein synthesis in rat ventral prostate from both castrate and testosterone treated animals. Proteins were detected by fluorography of 35S-methionine incorporation. In the soluble or cytosol fraction, four major proteins that have molecular weights less than 25,000 and isoelectric points (pI) less then 6.0 and one than has a molecular weight above 30,000 and pI 6.6 are under androgen control. One of these proteins with molecular weight 12,000 and pI 5.4 also appears in the microsomal fraction. Using nonequilibrium pH gradient electrophoresis, soluble proteins of pI greater than 7.0 were investigated. One major protein of 20-25,000 daltons and pI 8.0 appears to be androgen dependent. The ventral prostate from castrate synthesized proteins which are not detectable in androgen stimulated castrates.

Animals↗
PubMed1980

Parameters of fixation disparity.

This paper reviews the definition, causation, and significance of fixation disparity and suggests that the magnitude and character of fixation disparity depend on several major parameters: individual differences in the efficiency of motor and sensory processes of binocularity; natural or prism-induced demands on motor fusion; the presence or absence of foveal or parafoveal fusion clues; and the presence or absence of vergence adaptation. The clinical and research usefulness of fixation disparity as an indicator of binocular stress is emphasized.

Adaptation, Ocular↗
PubMed1980

Effect of spironolactone on androgen-dependent proteins in the ventral prostate of the rat.

The effect of spironolactone on five androgen-dependent proteins in the ventral prostate of the rat was investigated by two-dimensional gel electrophoresis. Spironolactone was given to intact male, castrated and androgen-stimulated castrated rats. It has been shown that spironolactone had no influence on the synthesis or accumulation of the androgen-dependent proteins in intact animals. However, spironolactone suppressed the restoration of the major androgen-dependent protein of low molecular weight in castrated rats given testosterone. The mechanism by which spironolactone exerts its anti-androgenic activity was shown to be unrelated to its capacity to inhibit the synthesis or accumulation of the five androgen-dependent proteins studied in this investigation.

Animals↗
PubMed1979

Isolation and partial purification of the major abundant class rat seminal vesicle poly(A+)-messenger RNA.

Total poly(A(+))-RNA (poly(A(+))-RNA(tot)) was isolated from rat seminal vesicle and its size distribution determined by 70% formamide 5-25% sucrose density analysis. One major peak was resolved in the 10-13 S region and accounted for approximately 35% of the total poly(A(+))-RNA applied. Preparative 1% SDS, 5-20% linear sucrose density gradients also resolved a single major peak in the 11S region (poly(A(+))(11S). Analysis of poly(A(+))-RNA(tot) and poly(A(+))-RNA(11S) under denaturing conditions on 2% agarose gel electrophoresis demonstrated two major components in both poly(A(+))-RNA populations. Size estimations for these components are 620 and 540 NT respectively. (3)H-cDNA was made to both poly(A(+))-RNA(tot) and poly(A(+))-RNA(11S). Back-hybridization of poly(A(+))-RNA(tot) and poly(A(+))-RNA(11S) to their respective (3)H-cDNA revealed a highly abundant class representing 41% and 85% of the sequences in their respective (3)H-cDNA's. The highly abundant class corresponded to 3-5 sequences present in 30,000-50,000 copies/cell. Invitro translation of poly(A(+))-RNA(11S) resulted in two major polypeptides coded for by the 620 NT long and 540 NT long poly(A(+))-RNA respectively.Images

Animals↗