Activation of the cGAS-STING pathway plays a key role in the innate immune response to cancer through Type-1 Interferon (IFN) production and T cell priming. Accumulation of cytosolic double-stranded DNA (dsDNA) within tumor cells and dying cells is recognized by the DNA sensor cyclic GMP-AMP synthase (cGAS) to create the secondary messenger cGAMP, which in turn activates STING (STimulator of INterferon Genes), resulting in the subsequent expression of IFN-related genes. This process is regulated by Three-prime Repair EXonuclease 1 (TREX1), a 3' → 5' exonuclease that degrades cytosolic dsDNA, thereby dampening activation of the cGAS-STING pathway, which in turn diminishes immunostimulatory IFN secretion.
View Article and Find Full Text PDFAntimicrob Agents Chemother
December 1997
The multiple antibiotic resistance operon (marORAB) in Escherichia coli controls intrinsic susceptibility and resistance to multiple, structurally different antibiotics and other noxious agents. A plasmid construct with marA cloned in the antisense direction reduced LacZ expression from a constitutively expressed marA::lacZ translational fusion and inhibited the induced expression of LacZ in cells bearing the wild-type repressed fusion. The marA antisense construction also decreased the multiple antibiotic resistance of a Mar mutant.
View Article and Find Full Text PDFMutagenesis at abasic sites was investigated in E.coli and simian kidney (COS) cells using a duplex shuttle vector containing synthetic analogs of deoxyribose on the phosphodiester backbone. Lesions were positioned on opposite strands of the vector.
View Article and Find Full Text PDFSinglet oxygen was generated in the gas phase at atmospheric pressure by the method of heterogeneous photosensitization. In vitro exposure of human lung WI-38 fibroblasts to gas-phase singlet oxygen resulted in sister chromatid exchange.
View Article and Find Full Text PDFPhotochem Photobiol
October 1992
Singlet-oxygen (1O2) was generated in the gas phase by heterogeneous photosensitization and bubbled into suspensions of phosphatidylcholine (PC) liposomes. Lipid peroxidation and membrane lysis were observed, and were dependent on the 1O2 concentration and the degree of unsaturation of the liposome. An analysis based on large target diffusion theory indicates that approximately 5000, 2800, and 1600 interactions were required for the lysis of large dioleoylPC, dilinoleoylPC and dilinolenoylPC liposomes, respectively.
View Article and Find Full Text PDFTwo patients developed large tears of the retinal pigment epithelium associated with choroidal effusion. One tear occurred after combined cataract/filtration surgery complicated by postoperative choroidal detachment; the second developed in a patient with idiopathic uveal effusion syndrome. Weakness of the junctions of the pigment epithelial cells secondary to the accumulation of fluid in the subretinal or suprachoroidal space may result in tearing of the retinal pigment epithelium as it is stretched.
View Article and Find Full Text PDFThe toxic effects of gas-phase singlet oxygen, 1O2, on the ciliated respiratory epithelium of hamster trachea have been demonstrated. Tracheal explants treated with 1O2 showed a dose-dependent decrease in cilia beating frequency and focal ciliostasis. A statistically significant decrease in ciliary activity occurred at 1O2 concentrations as low as 154 ppb after a 2-hr exposure.
View Article and Find Full Text PDFAdult female Swiss-Webster and B6C3F1 mice received distilled water only or water containing 0.1, 1.0, 10, 100, or 1000 ppb of aldicarb daily for 34 days.
View Article and Find Full Text PDFA 5-month-old male infant with chondrodystrophia punctata type Conradi-Hünermann showed electrocardiographically an increasing right ventricular hypertrophy. Echocardiographically an enormous enlarged right ventricle with signs of supra-systemic pressure was found. No other intracardiac defects could be seen.
View Article and Find Full Text PDFAutoradiographic identification of unscheduled DNA synthesis (UDS) in short-term organ culture of hamster tracheal epithelium has been used as a predictive test for mutagenic and/or carcinogenic compounds. Tracheal explants were treated for 2 h with singlet delta oxygen plus [3H]thymidine. Silver grains over the nuclei of epithelial cells from the superficial layer of the mucosa were observed, indicating UDS.
View Article and Find Full Text PDFSinglet delta oxygen (1O2) was generated at atmospheric pressure using heterogeneous gas-phase photosensitization. Polycyclic aromatic hydrocarbons (PAH), known constituents of the atmosphere, were found to be efficient sensitizers in the production of singlet delta oxygen under simulated environmental conditions. A novel mechanism involving singlet delta oxygen is proposed in which PAH on particle surfaces are self-activated to form direct-acting mutagens.
View Article and Find Full Text PDFExposure of hamster tracheal organ cultures to gas phase singlet delta oxygen, O2, at atmospheric pressure produced significant alterations in the mucociliary epithelium resulting in changes in ciliary activity and cellular morphology.
View Article and Find Full Text PDFA prematurely born infant (35 weeks of gestational age) developed signs of respiratory insufficiency, and fever, beginning at the 17th day of life; x-ray examinations showed small and large spotted lung infiltrations which grew and confluated rapidly in spite of broad antibiotic treatment. At the 29th day intubation and artificial ventilation became necessary; cultures of tracheal fluid remained sterile, Ziehl-Neelsen stains were not done. The infant died at the age of 35 days.
View Article and Find Full Text PDFA survey was made to determine the levels of insect damage and rodent excreta pellets in wheat. The analytical data obtained represented the various grade designations of wheat normally encountered during wheat grade certification in the 34 Agricultural Marketing Service, Grain Division, field offices. The mean and range of weights of insect-damaged kernels per 100 g and rodent excreta pellets and pellet fragments per kilogram were 71.
View Article and Find Full Text PDFMonatsschr Kinderheilkd (1902)
August 1978
Z Geburtshilfe Perinatol
February 1978
Perinatal mortality is a qualitative parameter for the obstetric and neonatologic efficiency of an obstetric center. The present study conducted at the Herford clinical center, based on 3,700 case histories from 1972 to 1976, revealed a drop of the uncorrected perinatal mortality from 35.08% to 14.
View Article and Find Full Text PDFThe present official first action method for the isolation of light filth from fig and fruit paste, 44.083(a), occasionally yields excessive plant debris on filter papers, which causes difficulty in effectively counting insect filth. The proposed method provides the option of an additional flotation of trapped off material in a Corning percolator.
View Article and Find Full Text PDFInorganic particulate matter in foods and drugs is discussed from the standpoint of determination by optical microscopy, source, and regulatory significance. Some particulate matter may be generated as extraneous material and traced to specific operational practices during processing and production with excessive levels associated with deficiencies in good manufacturing practices. Other particles, such as talc and asbestos, may be incorporated as additives during their use in production.
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