The Influences of Chromium Supplementation on Glycemic Control,Markers of Cardio-Metabolic Risk,and Oxidative Stress in Infertile Polycystic ovary Syndrome Women Candidate for In vitro Fertilization: a Randomized,Double-Blind,Placebo-Controlled Trial

This study was carried out to investigate the effects of chromium intake on glycemic control, markers of cardio-metabolic risk, and oxidative stress in infertile polycystic ovary syndrome (PCOS) women candidate for in vitro fertilization (IVF). This randomized double-blind, placebo-controlled trial was done among 40 subjects with infertile PCOS candidate for IVF, aged 18–40 years old. Individuals were randomly allocated into two groups to take either 200 μg/day of chromium (n?=?20) or placebo (n?=?20) for 8 weeks. Biochemical parameters were assessed at baseline and at end-of-trial. Compared with the placebo, taking chromium supplements led to significant reductions in fasting plasma glucose (??2.3?±?5.7 vs. +?0.9?±?3.1 mg/dL, P?=?0.03), insulin levels (??1.4?±?2.1 vs. +?0.4?±?1.7 μIU/mL, P?=?0.004), homeostatic model of assessment for insulin resistance (??0.3?±?0.5 vs. +?0.1?±?0.4, P?=?0.005), and a significant increase in quantitative insulin sensitivity check index (+?0.004?±?0.008 vs. ??0.001?±?0.008, P?=?0.03). In addition, chromium supplementation significantly decreased serum triglycerides (??19.2?±?33.8 vs. +?8.3?±?21.7 mg/dL, P?=?0.004), VLDL- (??3.8?±?6.8 vs. +?1.7?±?4.3 mg/dL, P?=?0.004) and total cholesterol concentrations (??15.3?±?26.2 vs. ??0.6?±?15.9 mg/dL, P?=?0.03) compared with the placebo. Additionally, taking chromium supplements was associated with a significant increase in plasma total antioxidant capacity (+?153.9?±?46.1 vs. ??7.8?±?43.9 mmol/L, P?<?0.001) and a significant reduction in malondialdehyde values (?0.3?±?0.3 vs. +?0.1?±?0.2 μmol/L, P?=?0.001) compared with the placebo. Overall, our study supported that chromium administration for 8 weeks to infertile PCOS women candidate for IVF had beneficial impacts on glycemic control, few variables of cardio-metabolic risk, and oxidative stress.     

Activity of myrosinase from Sinapis alba seeds immobilized into Ca-polygalacturonate as a simplified model of soil-root interface mucigel

Ca-polygalacturonate is a demethoxylated component of pectins which are constitutive of plant root mucigel. In order to define the role of root mucigel in myrosinase immobilization and activity at root level, a myrosinase enzyme which had been isolated from Sinapis alba seeds was immobilized into Ca-polygalacturonate. The activity profile for the immobilized and free enzyme was evaluated using the pH-Stat method as a function of time, temperature, and pH. The Michaelis-Menten kinetic parameters change between the immobilized (V _max ?=?127?±?13 U mg^?1 protein; K _M ?=?6.28?±?0.09?mM) and free (V _max ?=?17?±?1 U mg^?1 protein; K _M ?=?0.96?±?0.01?mM) forms of myrosinase, probably due to conformational changes involving the active site as a consequence of enzyme immobilization. Immobilized enzyme activity evaluated as a function of different substrates gave the highest value with nasturtin, the glucosinolate that is typical of several brassicaceae plant roots containing the glucosinolate-myrosinase defensive system. No feedback regulation mechanism was found in the presence of an excess of enzymatic reaction products (i.e. allyl isothiocyanate or sulphate). The high enzyme immobilization yield into Ca-polygalacturonate and its activity preservation under different conditions suggest that the enzyme released by plants at root level could be entrapped in root mucigel in order to preserve its activity.     

A Highly Efficient NADH-dependent Butanol Dehydrogenase from High-butanol-producing Clostridium sp. BOH3

Butanol has been considered as a better alternative fuel and it can be produced from anaerobic Clostridial fermentation. Though several enzymes are involved in the biosynthesis of butanol in Clostridia, butanol dehydrogenase (BDH) is understood to play a major role, which catalyzes the conversion of butyraldehyde into butanol at the expenditure of a cofactor NAD(P)H. Recently, the strain Clostridium sp. BOH3 is reported to generate high level of butanol from monosugars. To investigate the BDH activity at various stages of fermentation, BOH3 was cultured in reinforced Clostridial medium with 30 g/l of glucose at 35 °C and the cells were harvested periodically from acid production and solvent production phases. During acid production, NADPH-dependent BDH activity is higher than NADH dependent BDH. Conversely, NADH-BDH activity is predominant during solvent production phase. The optimum pHs for NADH and NADPH-BDH are estimated as pH?6 and 8, respectively. By employing three steps of purification, NADH-BDH is purified to 102-fold with 36 % yield. Subsequent characterization reveals that NADH-BDH is a dimer composed of two subunits depicting the molecular weight of 44 kDa. The peptide finger printing analysis (MS/MS) suggests that the purified protein has higher homology with bifunctional acetaldehyde-CoA and alcohol dehydrogenase of Clostridium acetobutylicum. The extensive kinetic studies show that NADH-BDH follows an ordered sequential bi bi mechanism. The calculated values of K _{butyraldehyde} and K _NADH are 8.35?±?0.25 and 0.076?±?0.02 mM, respectively, whereas V _max is 4.02?±?0.07 μmol/(mg protein. min). The purified NADH-BDH retains 70 % of its initial activity after 7 days at 4 °C.     

Palm tocotrienol-rich fraction reduced plasma homocysteine and heart oxidative stress in rats fed with a high-methionine diet

Oxidative stress contributes to cardiovascular diseases. We aimed to study the effects of palm tocotrienol-rich fraction (TRF) on plasma homocysteine and cardiac oxidative stress in rats fed with a high-methionine diet. Forty-two male Wistar rats were divided into six groups. The first group was the control. Groups 2–6 were fed 1 % methionine diet for 10 weeks. From week 6 onward, folate (8 mg/kg diet) or palm TRF (30, 60 and 150 mg/kg diet) was added into the diet of groups 3, 4, 5 and 6. The rats were then killed. Palm TRF at 150 mg/kg and folate supplementation prevented the increase in plasma total homocysteine (4.14?±?0.33 and 4.30?±?0.26 vs 5.49?±?0.25 mmol/L, p?<?0.05) induced by a high-methionine diet. The increased heart thiobarbituric acid reactive substance in rats fed with high-methionine diet was also prevented by the supplementations of palm TRF (60 and 150 mg/kg) and folate. The high-methionine group had a lower glutathione peroxidase activity (49?±?3 vs 69?±?4 pmol/mg protein/min) than the control group. This reduction was reversed by palm TRF at 60 and 150 mg/kg diet (p?<?0.05), but not by folate. Catalase and superoxide dismutase activities were unaffected by both methionine and vitamin supplementations. In conclusion, palm TRF was comparable to folate in reducing high-methionine diet-induced hyperhomocysteinemia and oxidative stress in the rats’ hearts. However, palm TRF was more effective than folate in preserving the heart glutathione peroxidase enzyme activity.     

The carbohydrate-binding module of Fragaria × ananassa expansin 2 (CBM-FaExp2) binds to cell wall polysaccharides and decreases cell wall enzyme activities “in vitro”

A putative carbohydrate binding module (CBM) from strawberry (Fragaria × ananassa Duch.) expansin 2 (CBM-FaExp2) was cloned and the encoding protein was over-expressed in Escherichia coli and purified in order to evaluate its capacity to bind different cell wall polysaccharides “in vitro”. The protein CBM-FaExp2 bound to microcrystalline cellulose, xylan and pectin with different affinities (K_ad = 33.6 ± 0.44 mL g^?1, K_ad = 11.37 ± 0.87 mL g^?1, K_ad = 10.4 ± 0.19 mL g^?1, respectively). According to “in vitro” enzyme assays, this CBM is able to decrease the activity of cell wall degrading enzymes such as polygalacturonase, endo-glucanase, pectinase and xylanase, probably because the binding of CBM-FaExp2 to the different substrates interferes with enzyme activity. The results suggest that expansins would bind not only cellulose but also a wide range of cell wall polymers.     

The stability of almond β-glucosidase during combined high pressure–thermal processing: a kinetic study

The thermal and the combined high pressure–thermal inactivation kinetics of almond β-glucosidase (β-d-glucoside glucohydrolase, EC 3.2.1.21) were investigated at pressures from 0.1 to 600 MPa and temperatures ranging from 30 to 80 °C. Thermal treatments at temperatures higher than 50 °C resulted in significant inactivation with complete inactivation after 2 min of treatment at 80 °C. Both the thermal and high pressure inactivation kinetics were described well by first-order model. Application of pressure increased the inactivation kinetics of the enzyme except at moderate temperatures (50 to 70 °C) and pressures between 0.1 and 100 MPa where slight pressure stabilisation of the enzyme against thermal denaturation was observed. The activation energy for the inactivation of the enzyme at atmospheric pressure was estimated to be 216.2?±?8.6 kJ/mol decreasing to 55.2?±?3.9 kJ/mol at 600 MPa. The activation volumes were negative at all temperature conditions excluding the temperature–pressure range where slight pressure stabilisation was observed. The values of the activation volumes were estimated to be ?29.6?±?0.6, ?29.8?±?1.7, ?20.6?±?3.2, ?41.2?±?4.8, ?36.5?±?1.8, ?39.6?±?4.3, ?31.0?±?4.5 and ?33.8?±?3.9 cm³/mol at 30, 35, 40, 45, 50, 60, 65 and 70 °C, respectively, with no clear trend with temperature. The pressure–temperature dependence of the inactivation rate constants was well described by an empirical third-order polynomial model.     

Production,Purification, and Characterization of α-Amylase from Solventogenic Clostridium sp. BOH3

A solventogenic strain of Clostridium sp. BOH3 produces extracellular α-amylase (7.15 U/mg protein) in reinforced clostridial medium supplemented with sugarcane bagasse hydrolysate (1 % w/v) and a small amount of starch (0.1 % w/v), which is essential for the expression of α-amylase. In the presence of α-amylase, BOH3 utilizes starch directly without any pretreatment and produces butanol almost equivalent (～90 %) to the production of butanol from glucose. α-Amylase can be purified from culture supernatant by using one-step weak anion exchange chromatography with a yield of 43 %. In peptide fingerprinting analysis, this enzyme shows homology with α-amylase produced by Clostridium acetobutylicum ATCC824. However, the molecular weight is 54 kDa, which is smaller than α-amylase of ATCC824 (84 kDa). This enzyme has optimum temperature at 45–50 °C and optimum pH at 4.5–5.5. Under this condition, the enzyme activity is 91.32 U/mg protein, and its K _m and V _max values are 1.71?±?0.02 mg/ml and 96.13?±?0.15 μmol/min/mg protein, respectively. Activity of this α-amylase can be enhanced (>1.5 times) by addition of Ca²⁺ and Co²⁺ and its activity can be maintained at an acidic pH (pH 3–5) for about 24 h. These unique characteristics suggest that this enzyme can be used for saccharification of starch for production of biofuel in one pot.     

Lead Accumulation as Possible Risk Factor for Primary Open-Angle Glaucoma

The objective of this study was to investigate the relationship between preeclampsia and iodine levels and magnesium concentration in the blood of subjects in the northeast Anatolia region where iodine deficiency is common. Blood specimens were obtained from 24 preeclamptic and 16 healthy pregnant women. Iodine levels in blood were determined by the Foss method based on the Sandell–Kolthoff reaction. Serum protein-bound iodine (PBI) levels and magnesium concentration in maternal blood were lower in patients with severe preeclampsia compared to normal pregnant women (8.46?±?1.22 vs. 11.46?±?1.71 μg/dL, p?<?0.001, 1.63?±?0.05 vs. 1.86?±?0.05 mg/dL, p?<?0.001, respectively). Serum PBI levels and magnesium concentration in umbilical cord blood were higher in patients with severe preeclampsia than in normal pregnant women (8.84?±?1.9 vs. 7.33?±?1.07 μg/dL, p?<?0.05, 2.48?±?0.03 vs. 2.02?±?0.01 mg/dL, p?<?0.001, respectively). There was a positive correlation between the serum PBI levels in maternal blood and magnesium concentration in maternal blood in patients with severe preeclampsia (r?=?0.41, p?<?0.05). Thus, iodine may be one factor contributing to the pathophysiology of preeclampsia. Iodine supplementation may be effective therapy in preeclamptic in pregnant women.     

Effect of Mg, Si, and Sr on growth and antioxidant activity of the marine microalga Tetraselmis suecica

Efforts to increase the productivity of microalgal cultures have been focused on the improvement of photobioreactors, but little attention has been paid to the nutritional requirements of microalgae in order to improve culture media formulation. In this study, the main goal was obtaining a high productivity for Tetraselmis suecica (Chlorophyta) in semicontinuous culture by adding magnesium (Mg), silicon (Si), and strontium (Sr) at concentrations from 0.01 to 10 mM; at the time, the effect on steady-state cell density, biochemical composition, and antioxidant activity of T. suecica was evaluated. Because productivity is higher in high-density cultures, the work was focused many times to cell density. Mg (3 mM) and Sr (0.1 mM) added separately reached the highest steady-state cell density (7.0?×?10⁶?±?0.4 cells mL^?1) in comparison to control (4.2?±?0.1 cells mL^?1), but simultaneous addition had a synergic effect, achieving 8.7?×?10⁶?±?0.6 cells mL^?1. Silicon (3 mM) significantly affected the steady-state cell density, reaching 6.0?±?0.3 cells mL^?1 and increased the cell ash-free dry weight, reaching 127?±?7.9 pg cell^?1 in comparison to control (102.7?±?5.0 pg cell^?1), resulting in an ash-free dry weight productivity of 0.75?±?0.07 g?L^?1 day^?1. The highest fatty acids content and antioxidant activity, measured by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) method were obtained with Sr 10 mM. Sr treatments showed a high correlation (R ²?=?0.98) between DPPH inhibition and polyphenolic content, explaining its high antioxidant activity. Therefore, the addition of Mg, Si, and Sr to culture medium of T. suecica is recommended to achieve high steady-state cell density in semicontinuous cultures.     

Growth,pigments, and biochemical composition of marine red alga Gracilaria crassa

The marine red alga Gracilaria crassa was investigated for its proximate composition, minerals, fatty acids, amino acids, and agar content to decipher its nutritional implications. The growth performance and pigments were studied under different combinations of temperature and salinity. On a dry weight basis the total lipid content was 1.30?±?0.05 %, protein was 5.18?±?0.64 %, carbohydrate was 42.0?±?1.2 %, ash was 43.18?±?1.15 %, and agar content was 21.52?±?0.73 %. Appreciable amounts of macro-, micro-nutrients (K?>?Na, Ca, Mg, and Fe), and essential amino acids (Ileu, His, Thr, Leu, and Lys) were found. Palmitic, stearic acid, and arachidonic acid were major fatty acids detected. The alga showed maximum daily growth rate (DGR %) 5.8?±?0.09 % at 25 °C, 35 ‰ salinity. The highest content of pigment R-phycoerythrin (444.7?±?1.9 μg g^?1 fresh weight (FW) basis) was obtained at 25 ‰ salinity at 35 °C while that of R-phycocyanin (476.3?±?2.3 μg g^?1 DW) at 30 ‰ salinity at 30 °C. This study revealed that this alga can be utilized as a potential source for food and feed. The data generated on best growth conditions will be very useful for farming of G. crassa in open sea. This alga could be used for production of natural colorants at defined control condition.     

Latent pulmonary hypertension in atrial septal defect: Dynamic stress echocardiography reveals unapparent pulmonary hypertension and confirms rapid normalisation after ASD closure

Objective

Closure of atrial septal defects (ASD) prevents pulmonary hypertension, right heart failure and thromboembolic stroke. The exact timing for ASD closure is controversial.

Methods

In a prospective study to address the question whether unapparent pulmonary hypertension can be revealed prior to right ventricular (RV) remodelling, patients were investigated before and 6, 12, and 24 months after ASD closure using exercise stress echocardiography (ESE) and ergospirometry (n?=?24).

Results

At rest, RV systolic pressure (RVSP) was normal in 58.8 %, slightly elevated in 26.5 %, and moderately elevated in 11.8 %. One patient showed severe pulmonary hypertension. During ESE, all patients with normal RVSP at rest exhibited an increase (25.7?±?1.2 mmHg vs. 45.3?±?2.3 mmHg, p?<?0.001). After closure the RVSP was lower, both at rest and ESE. RV diameters decreased too. Tricuspid annulus plane systolic excursion (TAPSE) at rest remained lower after closure (24.0?±?0.9 vs. 22.0?±?0.9 mm, p?<?0.05). TAPSE in ESE was elevated, and stayed stable after closure (30.1?±?1.8 mm vs. 29.3?±?1.6 mm). Before closure, RV systolic tissue velocities (s^a) at rest were normal and decreased after closure (14.0?±?1.0 cm/s vs. 11.5?±?0.7 (6 month) vs. 10.6?±?0.5 cm/s (12 month), p?<?0.05). During ESE, s^a velocity was similar before and after closure (23.0?±?1.3 cm/s vs. 23.3?±?1.9 cm/s). Maximal oxygen uptake (VO₂/kg) did not differ between baseline and follow-ups.

Conclusion

Latent pulmonary hypertension may become apparent in ESE. ASD closure leads to a significant reduction in this stress-induced pulmonary hypertension and to a decrease in the right heart diameters indicating reverse RV remodelling. RV functional parameters at rest did not improve. The VO₂/kg did not change after ASD closure.     

The Effects of Magnesium and Zinc Co-Supplementation on Biomarkers of Inflammation and Oxidative Stress,and Gene Expression Related to Inflammation in Polycystic Ovary Syndrome: a Randomized Controlled Clinical Trial

Magnesium and zinc are known to exert multiple beneficial effects including anti-inflammatory and antioxidant actions. To our knowledge, data on the effects of magnesium and zinc co-supplementation on biomarkers of inflammation and oxidative stress and gene expression related to inflammation in subjects of polycystic ovary syndrome (PCOS) are scarce. This study was conducted to evaluate the effects of magnesium and zinc co-supplementation on biomarkers of inflammation and oxidative stress and gene expression related to inflammation in subjects with PCOS. This randomized double-blind, placebo-controlled trial was conducted among 60 subjects with PCOS diagnosed according to the Rotterdam criteria, aged 18–40 years old. Participants were randomly assigned into two groups to take either 250 mg of magnesium oxide plus 220 mg of zinc sulfate (containing 50 mg zinc) supplements (n?=?30) or placebo (n?=?30) twice a day for 12 weeks. Biomarkers of inflammation and oxidative stress were assessed at baseline and at end of treatment. Gene expression related to inflammatory cytokines was assessed in peripheral blood mononuclear cells (PBMCs) of PCOS women with RT-PCR method. After the 12-week intervention, compared with the placebo, magnesium and zinc co-supplementation significantly decreased serum high-sensitivity C-reactive protein (hs-CRP) (??1.6?±?2.4 vs. +?0.1?±?0.7 mg/L, P?=?0.001) and protein carbonyl (PCO) (??0.14?±?0.28 vs. +?0.02?±?0.07 mmol/mg protein, P?=?0.002) and significantly increased plasma total antioxidant capacity (TAC) levels (+?60.7?±?69.4 vs. ??1.5?±?141.5 mmol/L, P?=?0.03). Results of RT-PCR demonstrated that compared with the placebo, magnesium and zinc co-supplementation downregulated gene expression of interleukin-1 (IL-1) (P?=?0.007) and tumor necrosis factor alpha (TNF-α) (P?=?0.03) in PBMCs of subjects with PCOS. Overall, magnesium and zinc co-supplementation, compared with the placebo, for 12 weeks among PCOS women had beneficial effects on serum hs-CRP, plasma PCO, TAC, and gene expression of IL-1 and TNF-α. Clinical trial registration number: http://www.irct.ir: IRCT201706075623N121.     

Probiotic Properties and Cellular Antioxidant Activity of <Emphasis Type="Italic">Lactobacillus plantarum</Emphasis> MA2 Isolated from Tibetan Kefir Grains

Lactobacillus plantarum MA2 was isolated from traditional Chinese Tibetan kefir grains. Its antioxidant properties had been demonstrated in vitro and in vivo previously. In the present study, the probiotic characteristics of this strain were further evaluated by investigating its acid and bile salt tolerances, cell surface hydrophobicity, and autoaggregation, respectively. In addition, the cellular antioxidant activity (CAA) assay was applied to test the antioxidant capacity of the isolate in different growth phases. Same method was also used to evaluate the antioxidant capacity of its fermentation supernatant, cell-free extract, and intact cell quantitatively. The results of probiotic characteristic tests showed that MA2 could survive at pH 2.5 and 0.3% bile salt. Meanwhile, the measurements of cell surface hydrophobicity and autoaggregation were 45.29?±?2.15 and 6.30?±?0.34%, respectively. The results of cellular antioxidant activity tests indicated that MA2 had high antioxidant potential. The CAA value of logarithmic phase cell-free extract of MA2 (39,450.00?±?424.05 μmol quercetin equivalents/100 g sample) was significantly higher than that in stationary phase cell-free extract (3395.98?±?126.06 μmol quercetin equivalents/100 g sample) and that of fermentation supernatant in logarithmic phase (2174.41?±?224.47 μmol quercetin equivalents/100 g sample) (p?<?0.05). The CAA method was successively applied to evaluate the antioxidant capacity of MA2 in this study, which suggests that it could be used as a useful method for lactic acid bacteria antioxidant potential evaluation.     

Phosphatase and phytase activities in nodules of common bean genotypes at different levels of phosphorus supply

Plants grown at limited P supply can increase the activity of phosphatases in roots to hydrolyse organic-P compounds in the soil thus improving plant P acquisition, but little information is available about the role of these enzymes for internal plant metabolism at limited-P conditions. This work intended to measure the activities of acid phosphatases and phytases in nodules of common bean (Phaseolus vulgaris) genotypes at different levels of P supply. The experiment was carried out in a 5?×?5 factorial design with four replicates, comprising five bean genotypes and five P levels (20, 40, 80, 160 and 320 μmol P plant^?1 week^?1) in nutrient solution. Root seedlings were inoculated with Rhizobium tropici and plants were grown in 1-l bottles. Nodule samples were detached from 39-day-old plants and enzyme activities were determined in crude extracts. Plants were harvested at the stage of pod setting. Polynomial models fitted to data indicated maximal values at the level of 194 μmol P for shoot mass, at 206 μmol P for nodule mass and at 221 μmol P for shoot N. Whereas shoot mass was 1.7 times lower at 20 than at 160 μmol P, nodule mass was 7.5 times lower. Concentration of P in nodules increased from 40 to 320 μmol P but remained stable between 20 and 40 μmol P, suggesting a minimal threshold concentration of 3 mg P g^?1 for nodule growth. Activities of phosphatases and phytases in nodules decreased strongly as P supply was raised from 20 to 80 μmol P, remaining almost stable at higher P levels. Phosphatase activity ranged from 1,154 to 406 nmol min^?1 g^?1 (nodule fresh mass) from 20 to 80 μmol P respectively, while the phytase activity ranged from 55 to 14 nmol min^?1 g^?1 from 20 to 80 μmol P. Bean genotypes differed in shoot and nodule mass at the levels of 80 and 160 μmol P, whilst they differed in nodule enzyme activities only at the lowest P level, the relationship between nodule enzyme activities and growth of different bean genotypes was not evident. It is concluded that bean plants at P-deficient conditions increase the activities of phosphatases and phytases in nodules. This may constitute an adaptive mechanism for N₂-fixing legumes to tolerate P deficiency, by increasing the utilisation of the scarce P within the nodules.     

Control of sorbitol metabolism in renal inner medulla of diabetic rats: regulation by substrate,cosubstrate and products of the aldose reductase reaction

Streptozotocin diabetes induces a 4-fold increase in the maximal velocity of inner medullary aldose reductase as determined in vitro but increases sorbital synthesis in intact inner medullary collecting duct (IMCD) cells only 1.3-fold [1]. In order to resolve this discrepancy we investigated the importance of intracellular factors in controlling the role of cellular sorbitol synthesis. These factors include glucose concentration, sorbitol concentration, the activity of the NADPH-regenerating pentose phosphate pathway, intracellular NADP and NADPH content, and intracellular reduced (GSH) and oxidized glutathione (GSSG). It was found that the apparent K_m of cellular sorbitol production for glucose was identical in control and diabetic rats ($\text{56 ± 18}\text{vs.}\text{59 ± 14}\text{mmol/l}\text{d}\text{-glucose}$), whereas V_max increased by 31% in diabetes. In inner medullary collecting duct cells of diabetic rats containing 146 ± 5 μmol sorbitol/g protein, sorbitol synthesis slightly lower (?15%), compared to cells which had been sorbitol-depleted prior to the experiment (87 ± 4 μmol sorbitol/g protein). However, no inhibitory effect of sorbitol (up to 200 mmol/l) was observed on aldose reductase activity in vitro. In diabetic rats the content of NADPH was about 32% lower than in the control rats (3.8 ± 0.3 vs. 5.6 ± 0.4 μmol/g protein) and the ratio of NADPH/NADP was decreased from 25.6 ± 5.1 to 8.6 ± 1.7. In homogenates of the inner medulla the activity of 6-phospho-gluconate dehydrogenase (EC 1.1.1.43) was identical in both experimental groups, so the pentose phosphate shunt seems to be unaltered. GSH content in diabetic rats was also diminished (4.2 ± 0.67 μmol/g protein vs. 7.41 ± 0.5 μmol/g protein) and the GSH/GSSG ratio fell from 92.6 to 57.4. In enzyme tests in vitro an apparent K_m of 7.3 ± 1.9 μmol/l of the aldose reductase for NADPH was found; NADP acted as competitive inhibitor with a apparent K_i of 183 ± 31 μmol/l. Aldose reductase activity was also found to be strongly inhibited by the SH-group reagent p-chloromercurybenzoesulfonate (apparent K_i = 0.85 · 10^?6 mol/l). Combining the results obtained on the properties of the aldose reductase in vitro and the observation made in the intact cells, the investigators suggest that the decrease in NADPH/ NADP ratio, as well as changes in the redox state in the cells of diabetic animals, can play a significant role in the control of sorbitol synthesis.     

Comparison of mitral annulus geometry between patients with ischemic and non-ischemic functional mitral regurgitation: implications for transcatheter mitral valve implantation

Background

Transcatheter mitral valve replacement (TMVR) is a new therapeutic option for high surgical risk patients with mitral regurgitation (MR). Mitral valve (MV) geometry quantification is of paramount importance for success of the procedure and transthoracic 3D echocardiography represents a useful screening tool. Accordingly, we sought to asses MV geometry in patients with functional MR (FMR) that would potentially benefit of TMVR, focusing on the comparison of mitral annulus (MA) geometry between patients with ischemic (IMR) and non ischemic mitral regurgitation (nIMR).

Methods

We retrospectively selected 94 patients with severe FMR: 41 (43,6%) with IMR and 53 (56,4%) with nIMR. 3D MA analysis was performed on dedicated transthoracic 3D data sets using a new, commercially-available software package in two moments of the cardiac cycle (early-diastole and mid-systole). We measured MA dimension and geometry parameters, left atrial and left ventricular volumes.

Results

Maximum (MA area 10.7?±?2.5 cm² vs 11.6?±?2.7 cm², p?>?0.05) and the best fit plane MA area (9.9?±?2.3 cm² vs 10.7?±?2.5 cm², p?>?0.05, respectively) were similar between IMR and nIMR. nIMR patients showed larger mid-systolic 3D area (9.8?±?2.3 cm² vs 10.8?±?2.7 cm², p?<?0.05) and perimeter (11.2?±?1.3 cm vs 11.8?±?1.5 cm, p?<?0.05) with longer and larger leaflets, and wider aorto-mitral angle (135?±?10° vs 141?±?11°, p?<?0.05). Conversely, the area of MA at the best fit plane did not differ between IMR and nIMR patients (9?±?1.1 cm² vs 9.9?±?1.5 cm², p?>?0.05).

Conclusions

Patients with ischemic and non-ischemic etiology of FMR have similar maximum dimension, yet systolic differences between the two groups should be taken into account to tailor prosthesis’s selection.

Trial registration

N.A.

     

Optimization of cultivation conditions for fatty acid composition and EPA production in the eustigmatophycean microalga Trachydiscus minutus

We determined the effects of cultivation conditions (nitrogen source, salinity, light intensity, temperature) on the composition of polyunsaturated fatty acids (PUFAs) and the production of eicosapentaenoic acid (EPA) in the laboratory cultured eustigmatophycean microalga, Trachydiscus minutus. T. minutus was capable of utilizing all nitrogen compounds tested (potassium nitrate, urea, ammonium nitrate, ammonium carbonate) with no differences in growth and only minor differences in fatty acid (FA) compositions. Ammonium carbonate was the least appropriate for lipid content and EPA production, while urea was as suitable as nitrates. Salinity (0.2 % NaCl) slightly stimulated EPA content and inhibited growth. Increasing salinity had a marked inhibitory effect on growth and PUFA composition; salinity at or above 0.8 % NaCl was lethal. Both light intensity and temperature had a distinct effect on growth and FA composition. The microalga grew best at light intensities of 470–1,070 μmol photons m^?2 s^?1 compared to 100 μmol photons m^?2 s^?1, and at 28 °C; sub-optimal temperatures (20, 33 °C) strongly inhibited growth. Saturated fatty acids increased with light intensity and temperature, whereas the reverse trend was found for PUFAs. Although the highest level of EPA (as a proportion of total FAs) was achieved at a light intensity of 100 μmol photons m^?2 s^?1 (51.1?± 2.8 %) and a temperature of 20 °C (50.9?±?0.8 %), the highest EPA productivity of about 30 mg L^?1?day^?1 was found in microalgae grown at higher light intensities, at 28 °C. Overall, for overproduction of EPA in microalgae, we propose that outdoor cultivation be used under conditions of a temperate climatic zone in summer, using urea as a nitrogen source.     

Effect of Zinc Supplementation on Thyroid Hormone Metabolism of Adolescents with Down Syndrome

Studies have evidenced that zinc metabolism is altered in the presence of Down syndrome, and zinc seems to have a relationship with the metabolic alterations usually present in this syndrome. In this work, the effect of zinc supplementation on thyroid hormone metabolism was evaluated in adolescents with Down syndrome. A prospective study was carried out on 16 adolescents with Down syndrome (age: 10–19 years) who were randomized for treatment with 30 mg zinc daily for 4 weeks. Diet evaluation was accomplished y using a 3-day dietary record, and the analysis was performed by the NutWin program, version 1.5. Anthropometric measurements were performed for evaluation of body composition. The Zn-related nutritional status of the groups was evaluated by means of zinc concentration determinations in plasma and erythrocytes using the method of atomic absorption spectroscopy, and the thyroid hormone was obtained by radioimmunoassay. The diet of patients with Down syndrome, before and after the intervention presented reduced energy level and adequate zinc concentrations. Mean plasma zinc values were 59.2?±?13.2 and 71.0?±?21.9 μg/dL before and after the intervention, respectively. Erythrocyte concentrations of the mineral before supplementation, instead, were 51.5 μg/dL?±?11.1 μg Zn/gHb, and at the end of the experiment, they were 42.9?±?8/5 μg Zn/gHb, with a significant statistical difference (p?<?0.05). Serum concentrations of T₄ hormone before and after zinc supplementation were 1.26?±?0.20 and 1.54?±?0.63 pg/mL, respectively. Mean T₃ values before intervention were 2.47?±?037 pg/mL and, after supplementation, 2.25?±?0.67 pg/mL, without significant statistical difference (p?>?0.05). Intervention with zinc showed to be effective in the stabilization of the concentrations of this mineral in plasma and erythrocytes, but had no influence on the metabolism of thyroid hormones.     

Decolorization of azo dyes by Geobacter metallireducens

Geobacter metallireducens was found to be capable of decolorizing several azo dyes with different structures to various extents. Pyruvate, ethanol, acetate, propionate, and benzoate could support 66.3?±?2.6?93.7?±?2.1 % decolorization of 0.1 mM acid red 27 (AR27) in 40 h. The dependence of the specific decolorization rate on AR27 concentration (25 to 800 μM) followed Michaelis–Menten kinetics (K _m?=?186.9?±?1.4 μΜ, V _max?=?0.65?±?0.02 μmol?mg protein^?1 h^?1). Enhanced AR27 decolorization was observed with the increase of cell concentrations ranging from 7.5 to 45 mgL^?1. AR27 decolorization by G. metallireducens was retarded by the presence of goethite, which competed electrons with AR27 and was reduced to Fe(II). The addition of low concentrations of humic acid (1?100 mgL^?1) or 2-hydroxy–1,4-naphthoquinone (0.5?50 μM) could improve the decolorization performance of G. metallireducens. High-performance liquid chromatography analysis suggested reductive pathway to be responsible for decolorization. This was the first study on azo dye decolorization by Geobacter strain and might improve our understanding of natural attenuation and bioremediation of environments polluted by azo dyes.