DSEF-1 is a member of the hnRNP H family of RNA-binding proteins and stimulates pre-mRNA cleavage and polyadenylation in vitro

DSEF-1 protein selectively binds to a G-rich auxiliary sequence element which influences the efficiency of processing of the SV40 late polyadenylation signal. We have obtained cDNA clones of DSEF-1 using sequence information from tryptic peptides isolated from DSEF-1 protein purified from HeLa cells. DSEF-1 protein contains three RNA-binding motifs and is a member of the hnRNP H family of RNA-binding proteins. Recombinant DSEF-1 protein stimulated the efficiency of cleavage and polyadenylation in an AAUAAA-dependent manner in in vitro reconstitution assays. DSEF-1 protein was shown to be able to interact with several poly(A) signals that lacked a G-rich binding site using a less stringent, low ionic strength gel band shift assay. Recombinant DSEF-1 protein specifically stimulated the processing of all of the poly(A) signals tested that contained a high affinity G-rich or low affinity binding site. DSEF-1 specifically increased the level of cross-linking of the 64 kDa protein of CstF to polyadenylation substrate RNAs. These observations suggest that DSEF-1 is an auxiliary factor that assists in the assembly of the general 3'-end processing factors onto the core elements of the polyadenylation signal.     

Evaluation of anti-nociceptive effects of neuronal nicotinic acetylcholine receptor (NAChR) ligands in the rat tail-flick assay

In the present investigation, anti-nociceptive effects of neuronal nicotinic acetylcholine receptor (NAChR) ligands, (+)- and (-)-nicotine, cytisine, methylcarbamylcholine (MCC), dimethylphenylpiperazinium iodide (DMPP), and (+/-)-epibatidine were evaluated in the rat tail-flick assay both after subcutaneous (s.c.) and intracerebroventricular (i.c.v.) administration. The pharmacology of the tail-flick response to NAChR ligands after s.c. and i.c.v. routes was similar. Epibatidine was the most potent ligand examined with a longer duration of action than any other agonist. (-)-Nicotine was more active than (+)-nicotine indicating stereospecificity. ICV administration studies indicated an apparent partial agonist activity for (+)-nicotine in the tail-flick response. Tail-flick responses to NAChR agonists are independent of opioid and muscarinic pathways and appear to be mediated both by central and peripheral NAChR recognition sites. Central administration of MCC activates both NAChR and muscarinic anti-nociceptive mechanisms. Studies employing the alpha-adrenergic receptor alkylating agent, phenoxybenzamine or the noradrenergic neurotoxin, N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4), suggested that the NAChR-noradrenergic and NAChR-serotoninergic interactions play an important role in the tail-flick response. Studies employing a selective alpha-bungarotoxin-sensitive NAChR receptor antagonist, methyllycaconitine (MLA), suggested a minimal role for these receptors in the tail-flick response. The biochemical studies also indicated that a sub-population of NAChR receptors are located pre-synaptically on noradrenergic and/or serotoninergic pathways in the hippocampus.     

Fluid dynamics and flow patterns in stirred tanks with a turbine impeller

Velocity profiles were measured in a stirred tank with a turbine impeller using a three-dimensional, pitot tube probe. A tangential jet model was used to describe the flow in the region of the impeller, and two-dimensional potential flow models and a circular jet were used to describe the flow in the rest of the tank. The tangential jet model accurately predicted the measurements from this work and comparable measurements reported in the literature for water and air, for varying impeller diameter and speeds and for different tank diameters. In the rest of the tank a three-dimensional, low velocity, flow field exists; and the center of circulation is not a true stagnation point. The flow at this point is tangential. The two-dimensional models only qualitatively described the flow in this region, and a three-dimensional model would be required. It was experimentally and theoretically confirmed that standard practice of using 10% baffles effectively controls the flow in the tank.     

Latency–probability curves for sequential decision models: A comment on Weatherburn.

Discusses D. Weatherburn's (see record 1979-25180-001) mathematical argument that shows that the relationship between response latency and response probability in sensory discrimination experiments does not determine the form of an underlying sequential decision process unless the time rates for implicit events are also specified. This argument is not denied, but in many cases the expected variation of time rates is not sufficient to rule out the use of the latency–probability graph. This is particularly the case if time rate variation is directly determined by stimulus magnitude or if variations due to motivation occur only from trial to trial rather than from session to session. It is concluded that, even if such variation is large, there is a considerable amount of information to be gained from latency–probability analysis. (13 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Kinetics and mechanisms of chemical reactions in nonequilibrium-plasma etching of silicon and silicon compounds

Plasma-chemical etching of silicon and silicon compounds is reviewed. It is shown that present data indicates that fluorine atoms and molecules are the main particles responsible for etching of silicon and that atomic fluorine is the main active particle for etching of silicon dioxide. Insufficient data exists to establish the contribution of charged and excited states to the etching of silicon and its compounds but oxygen atoms and molecules are seen to have a strong influence and fluorocarbon radicals can passivate the surface by forming polymer films.     

Quality at time of purchase of dried milk products commercially packaged in reduced oxygen atmosphere

Nonfat dry milk (NDM) and powdered whey beverages are available at the retail level, packaged in No. 10 cans in a reduced oxygen atmosphere to prolong shelf life. The objective of this research was to determine the sensory and nutritional quality of these dried milk products at the time of purchase. In the 10 brands tested, wide variation existed in headspace oxygen, can seam quality, sensory quality, and vitamin A (with 6 of 10 brands entirely lacking the vitamin). Manufacturers of dried milk products packaged in cans for long-term storage need to give careful attention to can seam quality, product labeling, and vitamin fortification. Consumers would be well advised to evaluate several brands of dried milk products prior to large quantity purchases.     

IL-1 in gingival crevicular fluid following closed root planing and papillary flap debridement

Interleukin (IL)-1 alpha and beta are cytokines which can mediate inflammatory, bone resorbing, and reparative effects in the periodontium, but few longitudinal data exist exploring their role following periodontal therapy. This study examined gingival crevicular fluid (GCF) concentrations of IL-1 alpha and IL-1 beta at sites with shallow sulci (SS) or inflamed moderate/advanced pockets (M/AP) before and 6 months after treatment with closed scaling/root planing (SC/RP) or papillary flap debridement (PFD), all in the same subject (n = 14 patients). No significant differences were noted in IL-1 alpha or beta concentrations (determined with two-site enzyme-linked immunosorbent assays) between SS and M/AP sites at baseline. While both therapies improved clinical parameters of periodontal disease, IL-1 alpha concentration increased significantly (p < 0.05) in M/AP-PFD sites 6 months after treatment, but were unchanged in other groups. IL-1 beta concentrations were numerically lower after therapy, except for a significant increase (p < 0.05) in M/AP-PFD sites. These data suggest that surgical wound healing in an inflamed, plaque-infected site (M/AP-PFD) results in prolonged production of IL-1, which may be a reflection of the extent of tissue trauma and delayed wound healing. In spite of increased IL-1 levels, these sites demonstrated significant short-term improvement in clinical attachment level (+ 1.8 mm, p < or = 0.001) postoperatively.     

When is facial pain trigeminal neuralgia?

The pain of trigeminal neuralgia can be excruciating and debilitating. Fortunately, effective medical and surgical therapies for the disorder exist. Successful treatment hinges on thorough history taking and accurate diagnosis. Diagnostic evaluation of patients with orofacial pain should include complete head and neck, dental, and neurologic examinations combined with radiologic imaging of the head and appropriate laboratory tests.