A single column method for the assay of adenylate cyclase

An improved, one-step method for the separation of cyclic AMP from other nucleotides on disposable columns of neutral aluminum oxide is described. The method consists of several modifications of an established assay for adenylate cyclase. These modifications were designed to increase the sensitivity of the method, to decrease the time required for column preparation, and to eliminate the variable elution patterns for cyclic AMP that are obtained when using aluminum oxide from different commercial sources. Uniform elution patterns and high recoveries (approximately 80%) of cyclic AMP were obtained when 0.1 M ammonium acetate was used to elute cyclic AMP instead of Tris-HCl buffer. Prior to column chromatography, the adenylate cyclase reactions were terminated with the addition of hydrochloric acid and the mixtures were heated to degrade acid-labile nucleotides that would otherwise elute with cyclic AMP from aluminum oxide columns. Disposable polypropylene columns, fabricated with a reservoir and fast-flow filters, were used for column chromatography. Low blank values, generally less than 15 dpm/assay tube, were obtained when the acidified reaction mixtures were applied directly to aluminum oxide columns without prior neutralization. The proposed method should be useful for the routine assay of adenylate cyclase activity.     

The calcium-dependent ribonuclease XendoU promotes ER network formation through local RNA degradation

How cells shape and remodel organelles in response to cellular signals is a poorly understood process. Using Xenopus laevis egg extract, we found that increases in cytosolic calcium lead to the activation of an endogenous ribonuclease, XendoU. A fraction of XendoU localizes to the endoplasmic reticulum (ER) and is required for nuclear envelope assembly and ER network formation in a catalysis-dependent manner. Using a purified vesicle fusion assay, we show that XendoU functions on the surface of ER membranes to promote RNA cleavage and ribonucleoprotein (RNP) removal. Additionally, RNA removal from the surface of vesicles by RNase treatment leads to increased ER network formation. Using human tissue culture cells, we found that hEndoU localizes to the ER, where it promotes the formation of ER tubules in a catalysis-dependent manner. Together, these results demonstrate that calcium-activated removal of RNA from membranes by XendoU promotes and refines ER remodeling and the formation of tubular ER.     

Simultaneous binding of Guidance Cues NET1 and RGM blocks extracellular NEO1 signaling

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Some Unique Properties of the Deoxyribonucleic Acid-Bearing Portion of the Bacterial Membrane

By using the M-band technique we have shown that portions of the membranes of Bacillus megaterium and Escherichia coli vary in their affinity for magnesium-Sarkosyl crystals and in phospholipid composition. The portion to which deoxyribonucleic acid is attached comprises as little as 4% of the total cell membrane, has a particularly high degree of affinity for magnesium-Sarkosyl crystals, and is rich in phosphatidylethanolamine. The M-band fractionation does not depend on the use of lysozyme.     

An open-label,multicenter study to evaluate the safe and effective use of the single-use autoinjector with an Avonex<Superscript>®</Superscript> prefilled syringe in multiple sclerosis subjects

Background  

The ability to self-inject in patients with multiple sclerosis (MS) has been associated with a reduced risk of missed injections and drug discontinuation, and a beneficial effect on patients' independence. However, injection anxiety, needle phobia and disease-related disability are major barriers to a patient's ability to self-administer treatment. Use of an autoinjector may improve patients' ability to self-inject. This study evaluated the safe and effective use of Avonex Pen™ (prefilled pen), a single use autoinjector, for intramuscular delivery of interferon beta-1a (IM IFNβ-1a, Avonex) in MS patients.     

Lysine biosynthesis inMethanobacterium thermoautotrophicum is by the diaminopimelic acid pathway

Methanobacterium thermoautotrophicum, an archaebacterium, possesses the first and last enzymes of the diaminopimelic acid pathway for lysine biosynthesis, dihydrodipicolinate synthase, and diaminopimelate decarboxylase. It does not have saccharopine dehydrogenase, the last enzyme of the aminoadipate pathway for lysine biosynthesis. The dihydrodipicolinate synthase is inhibited but not repressed by lysine. We conclude that this microbe uses the diaminopimelate pathway for synthesis of lysine.Deceased.     

Anti‐angiogenic therapy: Adapting strategies to overcome resistant tumors

Healthy cells, as well as benign and malignant tumors, depend upon the body's blood supply to bring in oxygen and nutrients and carry away waste products. Using this property against tumors, anti‐angiogenic therapy targets the tumor vasculature with the aim of starving the tumor, and has demonstrated exceptional clinical efficacy against a number of tumors. This review discusses the current state of knowledge regarding anti‐angiogenic therapies presently available to patients, and garners from both preclinical and clinical literature the benefits and side effects associated with anti‐angiogenic therapies, the unfortunate mechanisms of acquired resistance to these novel therapeutics, and highlights promising next generation anti‐angiogenics that may overcome the limitations encountered with first generation therapies. J. Cell. Biochem. 111: 543–553, 2010. © 2010 Wiley‐Liss, Inc.