1.Biomimetic Mineralization of the Alginate/Gelatin/Calcium Oxalate Matrix for Immobilization of Pectinase: Influence of Matrix on the Pectinolytic Activity.
Bustamante-Vargas CE1, de Oliveira D2, Valduga E3, Venquiaruto LD3, Paroul N3, Backes GT3, Dallago RM4. Appl Biochem Biotechnol. 2016 Apr 4. [Epub ahead of print]
Pectinases catalyze the degradation of pectic substances and are used in several processes, mainly in food and textile industries. In this study, a biomimetic matrix of alginate/gelatin/calcium oxalate (AGOCa) was synthesized for the in situ immobilization via encapsulation of crude pectinase from Aspergillus niger ATCC 9642, obtaining an immobilization efficiency of about 61.7 %. To determine the performance of AGOCa matrix, this was compared to control matrices of alginate/calcium oxalate (AOxal) and alginate/water (ACa). By the evaluation of pH and temperature effects on the enzyme activity, it was observed an increase on pectinolytic activity for both three tested matrices with an increase on pH and temperature. The kinetic parameters for pectinase immobilized in the three matrices were determined using citric pectin as substrate. Values of K m of 0.003, 0.0013, and 0.0022 g mL-1 and V max of 3.85, 4.32, and 3.17 μmol min-1 g-1 for AGOCa, AOxal, and ACa matrices were obtained, respectively.
2.Crystal structure of bis-(2-methyl-1H-imidazol-3-ium) di-hydroxidobis(oxalato-κ(2) O (1),O (2))stannate(IV) monohydrate.
Diop MB1, Diop L1, Plasseraud L2, Maris T3. Acta Crystallogr E Crystallogr Commun. 2016 Feb 17;72(Pt 3):355-7. doi: 10.1107/S2056989016002061. eCollection 2016.
In the structure of the hydrated title salt, (C4H7N2)2[Sn(C2O4)2(OH)2]·H2O, the asymmetric unit comprises one stannate(IV) dianion, two organic cations and one water mol-ecule of crystallization. The [Sn(C2O4)2(OH)2](2-) dianion consists of an Sn(IV) atom chelated by two oxalate anions and coordinated by two OH(-) ligands in a cis octa-hedral arrangement. Neighbouring anions are connected through O-H⋯O hydrogen bonds between hydroxide groups and non-coordinating oxalate O atoms into layers expanding parallel to (100). In addition, cations and anions are linked through N-H⋯O hydrogen bonds, and the water mol-ecule bridges two anions with two O-H⋯O hydrogen bonds and is also the acceptor of an N-H⋯O hydrogen bond with one of the cations. Weak C-H⋯O hydrogen bonds are also observed. The intricate hydrogen bonding leads to the formation of a three-dimensional network.
3.[Epidemiological study on urinary stones in the region of Fez and the risk of recurrence].
El Habbani R1, Chaqroune A2, Sqalli Houssaini T3, Arrayhani M3, El Ammari J4, Dami F3, Chouhani BA3, Lahrichi A5. Prog Urol. 2016 Apr;26(5):287-94. doi: 10.1016/j.purol.2016.02.004. Epub 2016 Mar 19.
OBJECTIVE: In Morocco, few works on morpho-constitutional analysis of urinary calculi have been published, especially for patients in the region of Fez. This work aims to make a retrospective epidemiological study on the nature of urinary calculi with patients from the region of Fez and control the urine of the same patients after a period of three months to report on the risk of recurrence.
4.Polyacrylic acid attenuates ethylene glycol induced hyperoxaluric damage and prevents crystal aggregation in vitro and in vivo.
Sridharan B1, Ganesh RN2, Viswanathan P3. Chem Biol Interact. 2016 Mar 24;252:36-46. doi: 10.1016/j.cbi.2016.03.020. [Epub ahead of print]
The study explores calcium oxalate crystal inhibiting characteristic of polyacrylic acid (pAA), an anionic polymer in in vitro and in vivo. Animals were divided into 5 groups where group 1 served as control, group 2 were made hyperoxaluric by supplementing with Ethylene glycol (EG) 0.75% (v/v) for 30 days. Group 3, 4 & 5 were also given with EG and treated simultaneously with 2.5, 5 & 10 mg of pAA/kg of body weight, respectively. Urine, serum and tissue analyses along with histological studies were performed at the end of the 30 days study. In vitro crystallization was significantly inhibited by pAA and further it was supported by particle size analyses, XRD and FT-IR studies. Toxicological analyses showed that pAA was safe to use in animals at concentrations below 100 mg/kg BW. In vivo anti-urolithic study showed significant improvement in urinary lithogenic factors (calcium, oxalate, phosphate, citrate & magnesium) and renal function parameters (creatinine, urea and protein).