Effect of polymorphic form on the functional properties of cellulose: A comparative study

The powder and tableting properties of cellulose II powders (MCCII) and (SDCII) were evaluated and compared with common direct compression binders. The cellulose II polymorphs offered more benefits in terms of functionality as compared with cellulose I (Avicel^® PH-102) spray dried lactose and starch. Spray dried cellulose II (SDCII) had a better disintegrant ability, but a lower compactibility than microcrystalline cellulose I (Avicel^® PH-102). However, when mixed and compressed with acetaminophen, SDCII was as compactable as cellulose I. Further, unprocessed cellulose II has a comparable compressibility to that of cellulose I. SDCII was found to be less friable, less sensitive to magnesium stearate, and possessed better acetaminophen loading capacity than unprocessed cellulose II and comparable to that of cellulose I. The cellulose II materials showed potential for use as a direct compression excipient.     

Focus: Zoonotic Disease: Zoonotic Ocular Onchocercosis by Onchocerca lupi

The parasitic filarioid Onchocerca lupi causes ocular disease characterized by conjunctivitis and nodular lesions. This nematode was first described in 1967 in a wolf from Georgia, and since then cases of infection from dogs and cats with ocular onchocercosis and sporadically from humans also with subcutaneous and cervical lesions caused by O. lupi have been reported from the Middle East, Europe, and North America. Due to its zoonotic potential, this parasitic infection has gained attention in the past 20 years. Phylogenetic studies have highlighted the recent divergence of O. lupi from other Onchocerca spp. and the importance of domestication in the evolutionary history of this worm. Moreover, the finding of an O. lupi genotype associated with subclinical and mild infection in the Iberian Peninsula, raises important questions about the pathogenicity of this presently enigmatic parasite.     

Deprotection of centromeric cohesin at meiosis II requires APC/C activity but not kinetochore tension

Genome haploidization involves sequential loss of cohesin from chromosome arms and centromeres during two meiotic divisions. At centromeres, cohesin''s Rec8 subunit is protected from separase cleavage at meiosis I and then deprotected to allow its cleavage at meiosis II. Protection of centromeric cohesin by shugoshin‐PP2A seems evolutionarily conserved. However, deprotection has been proposed to rely on spindle forces separating the Rec8 protector from cohesin at metaphase II in mammalian oocytes and on APC/C‐dependent destruction of the protector at anaphase II in yeast. Here, we have activated APC/C in the absence of sister kinetochore biorientation at meiosis II in yeast and mouse oocytes, and find that bipolar spindle forces are dispensable for sister centromere separation in both systems. Furthermore, we show that at least in yeast, protection of Rec8 by shugoshin and inhibition of separase by securin are both required for the stability of centromeric cohesin at metaphase II. Our data imply that related mechanisms preserve the integrity of dyad chromosomes during the short metaphase II of yeast and the prolonged metaphase II arrest of mammalian oocytes.     

Venom of the crotaline snake Atropoides nummifer (jumping viper) from Guatemala and Honduras: comparative toxicological characterization,isolation of a myotoxic phospholipase A2 homologue and neutralization by two antivenoms

A comparative study was performed on the venoms of the crotaline snake Atropoides nummifer from Guatemala and Honduras. SDS-polyacrylamide gel electrophoresis, under reducing conditions, revealed a highly similar pattern of these venoms, and between them and the venom of the same species from Costa Rica. Similar patterns were also observed in ion-exchange chromatography on CM-Shephadex C-25, in which a highly basic myotoxic fraction was present. This fraction was devoid of phospholipase A₂ activity and strongly reacted, by enzyme-immunoassay, with an antiserum against Bothrops asper myotoxin II, a Lys-49 phospholipase A₂ homologue. A basic myotoxin of 16 kDa was isolated to homogeneity from the venom of A. nummifer from Honduras, showing amino acid composition and N-terminal sequence similar to those of Lys-49 phospholipase A₂ variants previously isolated from other crotaline snake venoms. Guatemalan and Honduran A. nummifer venoms have a qualitatively similar toxicological profile, characterized by: lethal; hemorrhagic; myotoxic; edema-forming; coagulant; and defibrinating activities, although there were significant quantitative variations in some of these activities between the two venoms. Neutralization of toxic activities by two commercially-available antivenoms in the region was studied. Polyvalent antivenom produced by Instituto Clodomiro Picado was effective in the neutralization of: lethal; hemorrhagic; myotoxic; coagulant; defibrinating; and phospholipase A₂ activities, but ineffective against edema-forming activity. On the other hand, MYN polyvalent antivenom neutralized: hemorrhagic; myotoxic; coagulant; defibrinating; and phospholipase A₂ activities, albeit with a lower potency than Instituto Clodomiro Picado antivenom. MYN antivenom failed to neutralize lethal and edema-forming activities of A. nummifer venoms.     

Phosphonate and phosphinate analogues of N-acylated gamma-glutamylglutamate. potent inhibitors of glutamate carboxypeptidase II

Phosphonate and phosphinate analogues of N-acylated gamma-glutamylglutamate were tested for the ability to inhibit glutamate carboxypeptidase II (GCP II). All of the compounds inhibit GCP II with IC(50) values in the low nanomolar range. The comparison of the results to previously reported inhibitory studies of the same compounds toward folylpoly-gamma-glutamyl synthetase (FPGS) and gamma-glutamyl hydrolase (gamma-GH) provides insight into structural and mechanistic features of each enzyme. Potential utility of these compounds as diagnostic agents and probes to understand folate or antifolate poly-gamma-glutamates metabolism is also described.     

Sulphatide content in a membrane fraction isolated from rabbit gastric mucosal: its possible role in the enzyme involved in H+ pumping

The sulphatide content of vesicular membrane fraction from rabbit mucosal gastric microsomes was analyzed. This vesicular membrane fraction, in addition to a high sulphatide content, was enriched in an ouabain-insensitive (H+ + K+)-ATPase, a (Mg+2 + K+)-activated phosphatase, and a H+ pumping activity. The enzyme system involved in the process of acid secretion and the translocation of K+ was studied in these membrane preparations treated with arylsulphatase A, an enzyme that specifically hydrolyzes sulphatide. The results indicate that the breakdown of sulphatides of the vesicular membrane fraction inactivated both the (H+ + K+)-ATPase activity and the H+ pumping. Both activities were partially restored by the sole addition of sulphatide. The K+-stimulated ouabain-insensitive phosphatase activity, suggested as a partial reaction of the (H+ + K+)-ATPase sequence, was unaffected by arylsulphatase. These results suggest that sulphatides may play a function in the high activity binding site for K+ of the enzyme involved in H+ pumping.     

Rational design and synthesis of affinity matrices based on proteases immobilized onto cellulose membranes

Discovery of new protease inhibitors may result in potential therapeutic agents or useful biotechnological tools. Obtainment of these molecules from natural sources requires simple, economic, and highly efficient purification protocols. The aim of this work was the obtainment of affinity matrices by the covalent immobilization of dipeptidyl peptidase IV (DPP-IV) and papain onto cellulose membranes, previously activated with formyl (FCM) or glyoxyl groups (GCM). GCM showed the highest activation grade (10.2?µmol aldehyde/cm²). We implemented our strategy for the rational design of immobilized derivatives (RDID) to optimize the immobilization. pH 9.0 was the optimum for the immobilization through the terminal α-NH₂, configuration predicted as catalytically competent. However, our data suggest that protein immobilization may occur via clusters of few reactive groups. DPP-IV?GCM showed the highest maximal immobilized protein load (2.1?µg/cm²), immobilization percentage (91%), and probability of multipoint covalent attachment. The four enzyme-support systems were able to bind at least 80% of the reversible competitive inhibitors bacitracin/cystatin, compared with the available active sites in the immobilized derivatives. Our results show the potentialities of the synthesized matrices for affinity purification of protease inhibitors and confirm the robustness of the RDID strategy to optimize protein immobilization processes with further practical applications.     

Monooxygenases involved in GA12 and GA14 synthesis in Gibberella fujikuroi

A microsomal preparation from mycelia of the gibberellin (GA)-producing fungus Gibberella fujikuroi catalyzed the first two steps in the conversion of the biosynthetic intermediate GA12-aldehyde to gibberellic acid (GA3). [14C]GA12-Aldehyde was converted to radiolabelled GA14, the major product, together with smaller amounts of non-hydroxylated GA12. The microsomal activities required reduced pyridine nucleotides and molecular oxygen. However, GA12 and GA14 synthesis differed markedly in the preferred electron source. Formation of GA12 required NADH or NADPH, while GA14 synthesis from GA12-aldehyde occurred only with NADPH. Marked differences were also found in the activating effect of FAD. When NADPH was the reductant, the rate of GA14 synthesis was enhanced 3.5 times by 5 microM FAD while this flavin nucleotide did not alter the synthesis of GA12. In contrast, GA12 synthesis was activated 3.8 times by 50 microM FAD in the presence of NADH. Both activities were inhibited by carbon monoxide and cytochrome c. These properties suggest that the 3beta-hydroxylation of GA12-aldehyde and further oxidation of carbon 7 are catalyzed by cytochrome P-450 monooxygenases in Gibberella fujikuroi.     

Atmospheric pollen in Santiago,Chile

In the city of Santiago (33°27'S70°38'W), Chile, an atmospheric pollen was monitored for three years using a volumetric Hirst-type pollen trap. The aims of the study were: to assess the pollen types present in the atmosphere, their actual concentrations and dynamics (means and maxima); to establish the pollen calendar for Santiago; and to analyze the aerobiologic characteristics distinguishing introduced and native taxa. Results show that atmospheric pollen mainly originates from the following taxa: Platanus , Poaceae, Acer , Cupressus , Chenopodiaceae, Urticaceae, Morus , Plantago and Oleaceae. For the most frequent pollen types graphs of their atmospheric presence constructed and a table with relevant yearly data for the three studied (July-June) is presented. It is concluded, that the airborne pollen is originating mainly from introduced taxa, many of which are considered allergenic. Native taxa showed no high concentrations. The highest aiborne pollen concentrations where observed in September, however, atmospheric pollen thought to be capable of causing pollinosis, where present during the whole year. The highest pollen concentrations are mostly from trees.     

Evaluation of the efficacy of two mouthrinses formulated for the relief of xerostomia of diverse origin in adult subjects

doi: 10.1111/j.1741‐2358.2012.00626.x Evaluation of the efficacy of two mouthrinses formulated for the relief of xerostomia of diverse origin in adult subjects Objective: To evaluate the efficacy of two new mouthrinses in the reduction of xerostomía‐associated symptomatology. Background: Xerostomia is a common chronic health condition that affects a great number of adults and significantly deteriorates quality of life, such that treatment is necessary. Materials and methods: Sixty‐seven adult subjects of both sexes presenting xerostomia of diverse origin were selected. Mouthrinses were tested using a double‐blind, randomized, cross‐over clinical trial with an intervining wash out period. Results: The 100% of subjects presented sensation of dry mouth, and 86% stated sensation of thick saliva. Burning tongue sensation, need to drink liquids to swallow and the sensation of swallowing difficulty were recorded in more than 50% of the patients. The most frequent pathologies in the sample were depression, arthritis, and arterial hypertension. Results of the clinical tests showed that mouthrinse 1 relieves sensation of dry mouth, need to drink liquids, and swallowing difficulty. In contrast, mouthrinse 2 relieves only latter two symptoms. Both rinses were more effective in relieving xerostomía‐associated symptomatology in patients taking 3 or more medicines simultaneously. Conclusion: Both mouthrinses were effective in relieving various xerostomia symptoms, could be distributed at a low cost, thereby improving the quality of life of population affected.