Benign intracranial hypertension in children

Ceftriaxone has a very high plasma protein binding (up to 98%) that is saturable and decreases with higher concentrations. This high protein binding results in high concentrations in plasma that are frequently related to the anti-infective activity. However, because only the free fraction of the drug is pharmacologically active and most of the infections are located in the tissues, it is more relevant to evaluate unbound concentrations in the interstitial space. Plasma and tissue pharmacokinetics of ceftriaxone in rats after single intravenous administration were investigated at two different concentrations (50 and 100 mg/kg). Both plasma and tissue samples were taken simultaneously from the same animal and analyzed by reversed-phase high-performance liquid chromatography. Free tissue levels in the thigh muscle were measured by microdialysis. The concentration in plasma is much higher than the free concentration in tissue. After determination of nonlinear protein binding by microdialysis and including these parameters in the pharmacokinetic model, it is possible to predict free concentrations in the interstitial space from plasma levels for any given dose.     

Poly(L‐lactic acid) with added α‐tocopherol and resveratrol: optical,physical, thermal and mechanical properties

Poly(L ‐lactic acid) (PLLA) films containing various concentrations of two natural antioxidants, α‐tocopherol and resveratrol, were fabricated by a melt compounding and compression molding process. The influence of the antioxidants on the optical properties such as color and UV‐visible light transmission was analyzed. The thermal, mechanical, rheological and physical properties of PLLA films with added antioxidants were assessed. PLLA films with added α‐tocopherol and resveratrol showed a yellowish brown color and the lightness was influenced by the presence of the antioxidants. The glass transition and melting temperatures were significantly reduced with the addition of antioxidants while enhanced thermal stability was observed, which could be a benefit and important for processing and production. PLLA films with added antioxidants were slightly more hydrophobic than neat PLLA. The combination effect of plasticizing and enhancement of the elastic modulus with differing concentrations of two antioxidants played a critical role in the mechanical and thermomechanical properties of PLLA films. The melt viscosity of the PLLA films with added antioxidants was substantially higher than that of neat PLLA. The higher melt viscosity and G′(ω) could be an indication of formation of entanglement between PLLA and the two antioxidants. Copyright © 2012 Society of Chemical Industry     

Calcium(II)(3) (3,5-Diisopropylsalicylate)(6)(H(2)O)(6) Activates Nitric Oxide Synthase: An Accounting for its Action in Decreasing Platelet Aggregation

Purposes of these studies were first; to determine whether or not Calcium(II)(3) (3,5- diisopropylsalicylate)(6)(H(2)O)(6) [Ca(II)(3)(3,5-DIPS)(6)], a lipophilic calcium complex, could decrease activated-platelet aggregation, and second; to determine whether or not it is plausible that Ca(II)(3)(3,5-DIPS)(6) decreases activated-platelet aggregation by facilitating the synthesis of Nitric Oxide (NO) by Nitric Oxide Synthase (NOS). The influence of Ca(II)(3)(3,5-DIPS)(6) on the initial rate of activated-platelet aggregation was determined by measuring the decrease in rate of increase in transmission at 550 nm for a suspension of Thrombin-CaCl(2) activated platelets following the addition of 0, 50, 100, 250, or 500 muM Ca(II)(3)(3,5-DIPS)(6). To establish that the Ca(lI)(3)(3,5- DIPS)(6)-mediated decrease in aggregation was due to activation of NOS, the effect of L-NMMA, an inhibitor of NOS, on the inhibition of platelet aggregation by Ca(II)(3)(3,5-DIPS)(6) was determined using a suspension of activated platelets contaimng 0 or 250 muM Ca(II)(3)(3,5-DIPS)(6) without or with 1 mM L-NMMA. An in vitro Bovine Brain NOS reaction mixture, containing CaCl(2) for the activation of Phosphodiesterase-3' ,5'-Cyclic Nucleotide Activator required for the activation of NOS, was used to determine whether or not Ca(II)(3)(3,5-DIPS)(6) could be used as a substitute for the addition of Ca. The decrease in absorbance at 340 nm, lambda maximum for NADPH, was measured to determine NOS activity following the addition of NOS to the complete reaction mixture containing either CaCl(2), Ca(II)(3)(3,5-DIPS)(6), or neither Ca compound. Increasing the concentration of Ca(II)(3)(3,5-DIPS)(6) caused a concentration related decrease in activated platelet aggregation. The addition of L-NMMA to activated platelets, in the absence of Ca(II)(3)(3,5-DIPS)(6), caused a 129% increase in initial rate of platelet aggregation. The initial rate of platelet aggregation decreased 74% with the addition of 250 muM Ca(II)(3)(3,5-DIPS)(6) and the addition of L-NMMA plus 250 muM Ca(II)(3)(3,5-DIPS)(6) caused a 197% decrease in initial rate of aggregation compared to the initial rate observed width the presence of 1 mM L-NMMA alone. There was only a small, 27%, increase in initial rate of 0.4 mM NADPH oxidation when 0.9 mM CaCl(2) was added to the NOS reaction mixture in comparison to the initial rate of NADPH oxidation with no addition of CaCI(2). Addition of an equivalent amount of Ca in the form of Ca(II)(3)(3,5-DIPS)(6), 333 muM, caused a 37% increase in initial rate of NADPH oxidation compared to the addition of 0.9 mM CaCl(2). Addition of increasing concentrations of L-NMMA plus 0.9 mM CaCl(2) or 333 muM Ca(II)(3)(3,5-DIPS)(6) to the NOS reaction mixture caused a concentration related increase in initial rate of NADPH oxidation. Addition of L-NMMA while expected to decrease NADPH oxidation actually increased the rate of NADPH oxidation. Additions of 133 muM or 267 muM Ca(II)(3)(3,5- DIPS)(6) also caused concentration related increases in initial rate of NADPH oxidation in the presence of 113 muM L-NMMA. However, the addition of 533 muM Ca(II)(3)(3,5-DIPS)(6) caused a dramatic decrease in initial rate of NADPH oxidation by NOS. It is concluded that: 1) Ca(II)(3)(3,5- DIPS)(6) activates platelet NOS in preventing platelet aggregation, 2) in vitro NOS activity can be observed spectrophotometrically by following the consumption of NADPH as a decrease in absorbance at 340 nm, 3) Ca(II)(3)(3,5-DIPS)(6) plays a role in enhancing Bovine Brain NOS activity resulting in an increased rate of NADPH oxidation by NOS, 4) Ca(II)(3)(3,5-DIPS)(6) is a useful form of Ca in activating NOS and superior to CaCl(2) with regard to the facilitation of a NADPH oxidation, and 5) L-NMMA stimulates Bovine Brain NOS activity rather than causing an inhibition of this enzyme and must serve as a reducible substrate for Bovine Brain NOS.     

High-voltage surge protection by a varistor-filled air gap

The electric discharge across a varistor granule filled air gap under a fast-rising voltage pulse was investigated for surge protection applications. The effects of temperature and pressure on the arc and the electrical conduction were analyzed by the characteristic changes in voltage waveforms triggered by a fast-rising high voltage pulse. In addition to the gap size, experimental results show that competing mechanisms among arc conduction, conduction through the varistor granule network, thermionic emission from Joule heating at granule-to-granule contact points, and the magnitude of the switching voltage dictate the maximum surge protection voltage for the filled air gap. Experimental evidence indicated that accumulated degradation was created at small contact points between varistor granules by repetitive assaults from longer duration, high voltage pulses. The uniqueness of using varistor over other dielectric granules in an air gap for surge protection is identified and discussed.     

Radiorecovery Activity of Dicopper(II) Tetrakis(3,5-Diiso propylsalicylate) Includes Recovery of Radiation-Induced Loss of Body Mass and Impaired Mouse Locomotion

Dicopper(II) tetrakis(3,5-diisopropylsalicylate), [Cu(II)(2)(3,5-DIPS)(4)], is effective in increasing survival of lethally irradiated mice when it is administered after irradiation. The possibility that this radiorecovery activity might also facilitate recovery from radiation-induced impaired increase in body mass and locomotion was examined. Cu(II)(2)(3,5-DIPS)(4) was used to treat LD 50/30 gamma irradiated female C57BL/6 mice after irradiation. A dose of 0, 5, 10, or 20 mumol Cu(II)(2) (3, 5-DIPS)(4) /kilogram of body mass was administered subcutaneously 3 hrs after LD 50/30 irradiation and change in body mass and locomotor activity measured daily throughout the 30 day post-irradiation period. Treatment with 5, 10, or 20 mumol Cu(II)(2) (3,5-DIPS)(4) /kg of body mass increased survival, which was statistically significant for the 10 mumol /kg of body mass-treated group compared to the vehicle-treated group (P<0.05), significantly (P<0.05) increased recovery of locomotion from days 13 to 15 post-irradiation onward for all treated groups compared to vehicle-treated mice, and increased recovery of body mass gain from day 14 onward for the 20 mumol /kg of body mass-treated group (P<0.001) and day 21, although not statistically significant, for the 10 mumol /kg of body mass-treated group. There were no statistically significant differences between the increase in survival, recovered increase in body mass, and recovered increase in locomotion for mice treated with 10 mumol or 20 mumol Cu(II)(2)(3,5-DIPS)(4) /kg on day 30 post-irradiation. It is concluded that Cu(II)(2)(3,5-DIPS)(4) in addition to increasing survival of irradiated mice increases the rate of recovery of radiation-induced decrease in body mass and locomotion.     

Refusal to eat in the elderly

Refusal to eat by the elderly, and subsequent malnutrition, occurs in both institutional and community settings. Causes include physiologic changes associated with aging, mental disorders such as dementia and depression, and medical, social, and environmental factors. Treatment approaches call for management of these causes while considering the roles that medicine, ethics, and culture play in the process.     

Orientation in operator algebras

A concept of orientation is relevant for the passage from Jordan structure to associative structure in operator algebras. The research reported in this paper bridges the approach of Connes for von Neumann algebras and ourselves for C*-algebras in a general theory of orientation that is of geometric nature and is related to dynamics.