Specific, regulated modification of RNAs is important for proper gene expression. tRNAs are rich with various chemical modifications that affect their stability and function. 7-Methylguanosine (mG) at tRNA position 46 is a conserved modification that modulates steady-state tRNA levels to affect cell growth.
View Article and Find Full Text PDFFew areas of geophysics are today progressing as rapidly as basic geomagnetism, which seeks to understand the origin of the Earth's magnetism. Data about the present geomagnetic field pours in from orbiting satellites, and supplements the ever growing body of information about the field in the remote past, derived from the magnetism of rocks. The first of the three parts of this review summarizes the available geomagnetic data and makes significant inferences about the large scale structure of the geomagnetic field at the surface of the Earth's electrically conducting fluid core, within which the field originates.
View Article and Find Full Text PDFEnviron Toxicol Chem
June 2009
Produced water collected from oil and gas platforms on the United Kingdom Continental Shelf was characterized for nonregulated pollutants through an effects-directed analysis procedure. Produced water samples were characterized for the presence of aryl hydrocarbon receptor (AhR) and estrogen receptor (ER) agonists using the dioxin-responsive, chemical-activated luciferase gene expression assay (DR-CALUX) and yeast estrogen screen (YES) bioassays. The AhR and ER agonists were then isolated by normal-phase, high-performance liquid chromatography and identified using gas chromatography coupled to mass spectrometry in a number of formats.
View Article and Find Full Text PDFThe analysis and presence of clotrimazole, an antifungal agent with logK(OW) > 4, was thoroughly studied in the aquatic environment. For that reason analytical methods based on gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry were developed and validated to quantify clotrimazole with limits of quantification down to 5 and 1 ng/L, respectively. Both methods were compared in an intercalibration exercise.
View Article and Find Full Text PDFThe occurrence and potential adverse effects of pharmaceutical compounds in the aquatic environment have received much scientific interest. Presented are analytical methodologies for the determination of 10 of the pharmaceuticals listed on the Oslo and Paris Commission for the protection of the Marine Environment of the North East Atlantic (OSPAR) hazardous substances website. In addition to these 10 substances, the chemical fluoxetine (Prozac) was also investigated.
View Article and Find Full Text PDFThis paper presents the results of a survey of the wastewater effluent and surface waters of the lower river Tyne, UK. Samples were analysed by reversed-phase high-performance liquid chromatography-electrospray tandem mass spectrometry following solid phase extraction, for the presence of 13 pharmaceuticals selected from the priority lists of the UK Environment Agency and the Oslo and Paris Commission (OSPAR). The pharmaceutical compounds measured were acetyl-sulfamethoxazole, clofibric acid, clotrimazole, dextropropoxyphene, diclofenac, erythromycin, ibuprofen, mefenamic acid, paracetamol, propranolol, sulfamethoxazole, tamoxifen and trimethoprim.
View Article and Find Full Text PDFActa Crystallogr D Biol Crystallogr
January 2001
Glutathione S-transferases (GSTs) belong to a family of detoxification enzymes that conjugate glutathione to various xenobiotics, thus facilitating their expulsion from the cell. GST activity is elevated in many insecticide-resistant insects, including the DDT-resistant malaria vector Anopheles gambiae. Crystals of the recombinant form of a GST from A.
View Article and Find Full Text PDFThe Vero cell assay presently used for virulence testing of verotoxigenic Escherichia coli (VTEC) requires at least 48-96 h where cytotoxicity effects are examined under a microscope. Here, a complimentary rapid assay was developed that measures endogenous lactate dehydrogenase (LDH) release from Vero or HEp-2 cells as an indicator of cytotoxicity. Toxin preparations from 24 VTEC strains induced 36-89% LDH from Vero cells and 15-62% LDH from HEp-2 cells in 12-16 h.
View Article and Find Full Text PDFThe original intent of special education pull-out services was to remove students from general education temporarily for intensive, individualized instruction in deficit areas. In many school districts, however, it seems that once students participate in pull-out services, there is little effort to return them to general education. One explanation for this is that not much is known about how best to prepare students for movement up the cascade of services, including reintegration into the mainstream.
View Article and Find Full Text PDFThree-dimensional numerical simulations of the geodynamo suggest that a super- rotation of Earth's solid inner core relative to the mantle is maintained by magnetic coupling between the inner core and an eastward thermal wind in the fluid outer core. This mechanism, which is analogous to a synchronous motor, also plays a fundamental role in the generation of Earth's magnetic field.
View Article and Find Full Text PDFWe initially investigated the effects of a gonadotropin-releasing hormone analog, leuprolide acetate, in 28 patients with moderate to severe functional bowel disease in a phase-II, randomized, double-blind, and placebo-controlled study using Lupron Depot 3.75 mg (which delivers a continuous low dose of drug for one month) or placebo given intramuscularly. After completing that 12-week study period during which their symptoms had improved significantly (P < 0.
View Article and Find Full Text PDFModerate to severe functional bowel disease results in debilitating abdominal pain, nausea, intermittent vomiting, early satiety, bloating, abdominal distension, and/or altered bowel habits. Because it occurs approximately 20-30 times more frequently in women than in men and its symptoms often coincide with the menstrual cycle, we hypothesized that reproductive steroids may antagonize diseased nerves of the gastrointestinal tract, enhancing the expression of symptoms. No effective or consistent therapy has existed for these patients.
View Article and Find Full Text PDFCatheter-related sepsis is a well-known complication associated with the administration of total parenteral nutrition. A strict aseptic approach, supplemented with a knowledge of how the infection occurs, will do much to avoid this problem.
View Article and Find Full Text PDFWe reviewed 13 patients with monocondylar fractures of the femur. Undisplaced fractures may require extensive radiological investigation to visualize the fracture. Anatomically reduced fractures may displace when treated non-operatively.
View Article and Find Full Text PDFNineteen chondrosarcomas are reported arising in proximal phalanges or metacarpal bones of the hand mainly in elderly patients, predominantly women. The usual clinical presentation was of a progressively painful large tumour, often arising in a dormant lesion near the metacarpo-phalangeal joint. Radiologically most showed some bone expansion with a poorly defined area of destruction and a considerable soft-tissue swelling.
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