Metal Supplement Research Articles

Trace metal optimization in CHO cell culture through statistical design of experiments.

A majority of the biotherapeutics industry today relies on the manufacturing of monoclonal antibodies from Chinese hamster ovary (CHO) cells, yet challenges remain with maintaining consistent product quality from high-producing cell lines. Previous studies report the impact of individual trace metal supplemental on CHO cells, and thus, the combinatorial effects of these metals could be leveraged to improve bioprocesses further. A three-level factorial experimental design was performed in fed-batch shake flasks to evaluate the impact of time wise addition of individual or combined trace metals (zinc and copper) on CHO cell culture performance. Correlations among each factor (experimental parameters) and response variables (changes in cell culture performance) were examined based on their significance and goodness of fit to a partial least square's regression model. The model indicated that zinc concentration and time of addition counter-influence peak viable cell density and antibody production. Meanwhile, early copper supplementation influenced late-stage ROS activity in a dose-dependent manner likely by alleviating cellular oxidative stress. Regression coefficients indicated that combined metal addition had less significant impact on titer and specific productivity compared to zinc addition alone, although titer increased the most under combined metal addition. Glycan analysis showed that combined metal addition reduced galactosylation to a greater extent than single metals when supplemented during the early growth phase. A validation experiment was performed to confirm the validity of the regression model by testing an optimized setpoint of metal supplement time and concentration to improve protein productivity.

Ochratoxin A-Induced Nephrotoxicity: Up-to-Date Evidence.

Ochratoxin A (OTA) is a mycotoxin widely found in various foods and feeds that have a deleterious effect on humans and animals. It has been shown that OTA causes multiorgan toxicity, and the kidney is the main target of OTA among them. This present article aims to review recent and latest intracellular molecular interactions and signaling pathways of OTA-induced nephrotoxicity. Pyroptosis, lipotoxicity, organic anionic membrane transporter, autophagy, the ubiquitin-proteasome system, and histone acetyltransferase have been involved in the renal toxicity caused by OTA. Meanwhile, the literature reviewed the alternative or method against OTA toxicity by reducing ROS production, oxidative stress, activating the Nrf2 pathway, through using nanoparticles, a natural flavonoid, and metal supplement. The present review discloses the molecular mechanism of OTA-induced nephrotoxicity, providing opinions and strategies against OTA toxicity.

Influence of vitamin coupled with micronutrient supplement on the biomethane production, process stability, and performance of mesophilic anaerobic digestion

Batch anaerobic digestion (AD) using municipal solid waste (MSW) as a substrate with anaerobic sludge as inoculum were carried out under mesophilic conditions to understand the effect of Vitamin supplement coupled with micronutrients on the AD process. Reactions were operated using various concentrations of vitamin and water-based metal supplementations. The stability and process performance in the low level supplementation was indicated by evaluating Volatile fatty acids to alkalinity ratio, pH as well as methane kinetics. The feasibility of AD process was further evaluated by cost-benefit ratio analysis. This study shows that Vitamin addition as a sole supplement had either no significant or negative effect on methane production and process performance of anaerobic digestion (AD). However, coupling the metal supplement with vitamins shows an increase in methane production up to 30% compared to sole vitamin supplement and control systems. This study also shows that high levels of metal supplementation were detrimental and 15% decline in methane production over the control system was observed in high concentrations. Low level addition improved the reactor performance and process stability. Moreover, cost/benefit ratios lower than 1 were achieved for these concentrations. Hence, low levels of vitamin and water-based metal supplementation at 0.5–5 mg/L, increased the methane production and process stability by approximately 15, and 25% respectively.

Nanofibrous cobalt oxide for electrocatalysis of CO2 reduction to carbon monoxide and formate in an acetonitrile-water electrolyte solution

The electrocatalytic reduction of carbon dioxide (CO2) is an attractive option to efficiently bind electrical energy from renewable resources in artificial carbon fuels and feedstocks. The strategy is considered as crucial part in closing the anthropogenic carbon cycle. In particular, the electrosynthetic production of C1 species such as carbon monoxide (CO) would radiate immense power, since these building blocks offer a versatile chemistry to higher carbon products and fuels. In the present study we report the exploration of the catalytic behavior of semiconducting Co3O4 nanofibers for the conversion of CO2 to CO predominantly with a Faradaic efficiency of 65%. We assist the process by expanding the electrode network with nanofibrous interconnections and hence are able to demonstrate the electrosynthesis of CO without applying any metal supplement. We use polyacrylnitrile (PAN) as template polymer to generate highly crystalline Co3O4 fibers to expand the catalytically active surface to volume ratio. The stability of the nanofibrous electrodes remains for 8 h at a geometric current density of approximately 0.5 mA/cm2 on a flat surface. The ease of synthesis and the comparatively high Faradaic yield for CO makes Co3O4 nanofibers a potential candidate for future large scale electrode utilization.

Research on residual stresses during hot stamping with flat and local-thickened plates

Residual stresses generated during hot stamping have a significant effect on the mechanical properties and dimensional stability of aluminum alloy sheet components. What is more, few studies have paid attentions to the effects of hot stamping parameters on residual stresses and the methods of reducing residual stresses during hot stamping of aluminum alloy plates with thickness around 5 mm. Hence, in this study, the effects of forming temperature, blank holder force, die entrance radius, die corner radius, and local thickening on the residual stresses of square cups were studied, by conducting both finite element simulations and experiment investigations of the hot stamping of 2024 aluminum alloy plates. The results showed that the residual stress distribution is not uniform through the thickness. Within the range of process parameters investigated in this study, increasing the forming temperature, blank holder force, and die corner radius or decreasing the die entrance radius all lead to lower values of residual stresses. Compared to flat plates, local-thickened plates can significantly reduce the residual stresses in hot stamped square cups, which is attributed to the metal supplement mechanism at the thickened locations. When the side length of the square-ring-shaped convex rib of the plate is equal to the punch width and the convex rib facing downward, lower residual stresses in square cups are obtained. The established residual stress calculation model is capable of describing the residual stress distribution in the bottom circular arc of hot stamped square cups.

Sub-chronic copper pretreatment reduces oxidative damage in an experimental Huntington's disease model.

Quinolinic acid (QUIN) striatal injection in rat reproduces the main neurochemical features of Huntington's disease (HD), including oxidative damage. In this study, we evaluated the effect of a copper (Cu) supplement in drinking water (90 ppm Cu, 28 days) on the QUIN-induced HD model in the rat. Copper exposure caused no signs of liver toxicity; however, it produced significant Cu accumulation in striatum. It is noteworthy that QUIN also caused increased striatal Cu content; when the supplement was administered to animals with QUIN-injury, an even higher metal striatal accumulation was observed. Cu pre-treatment preserved striatal gamma-aminobutyric acid (GABA) content, which was reduced by QUIN intrastriatal injection. Similarly, apomorphine-induced circling behavior was reduced in Cu-pretreated QUIN-damaged rats. Metal supplement in drinking water prevented both lipid peroxidation and reactive oxygen species (ROS) formation caused by QUIN in striatum. In Cu-treated groups, superoxide dismutase-1 (SOD1) activity showed a significant increase, while SOD2 activity was slightly enhanced. Although the pathophysiological role for higher Cu levels in patients with HD and in experimental models of the disease is not fully understood, results in the present study suggest that Cu oral intake stimulates anti-oxidant defenses, an effect that may be a potential factor for reducing the progression of HD.

Zinc supplement greatly improves the condition of parkin mutant Drosophila

Parkinson's disease (PD) is a progressive neurodegenerative disorder in which oxidative stress is implicated as a major causative factor. Mutations in the gene encoding Parkin, a ubiquitin ligase, are responsible for a familial form of PD. In a Drosophila disease model lacking Parkin (park(25) null mutant), we tested the effect of zinc supplementation. Zinc is an essential trace metal and a component of many enzymes and transcriptional regulators. Unlike copper and iron, zinc is not redox-active and under most conditions serves as an antioxidant. We find that the condition of parkin mutants raised on zinc-supplemented food is greatly improved. At zinc concentrations where controls begin to show adverse effects as a result of the metal supplement, parkin mutants perform best, as manifested in a higher frequency of reaching adulthood, extended lifespan and improved motoric abilities.

Decontamination of water polluted by heavy metals with Taro (Colocasia esculenta) cultured in a hydroponic NFT system

The toxicity and bioaccumulation of two heavy metals—lead (Pb) and cadmium (Cd)—in a semi-aquatic plant, Colocasia esculenta (L. Schott), from a synthetic heavy metal solution were studied. Young plants of equal size were grown hydroponically in shallow raceways containing Hoagland medium amended with 20, 40, and 60 mg l−1 of Pb and 2, 4, and 6 mg l−1 of Cd. The medium containing heavy metals was allowed to flow through the raceways with a change in influent heavy metal solution on every 5th day. The experiment was continued for 20 days. A set of control raceways—one comprised of nutrient medium with heavy metal supplements, devoid of plants, and another with the plants and nutrient medium having no metal supplement—was also simultaneously run. Chlorosis in the leaves was the prominent toxicity symptom observed due to Pb and Cd on the test plants. A significant decrease in the relative growth, biomass productivity, and total chlorophyll content were noticed in the plants with an increase in concentration of metal supplement in the solution and exposure time. Both metals accumulated to higher concentrations in the roots than in shoots, suggesting that the metals were bound to the root cells and their translocation to the leaves was limited. The results of the 20-day-long experiments indicate that from a phytoremediation perspective, C. esculenta is a promising plant species for remediation of wastewater polluted with lower concentrations of Pb and Cd.

SPIRULINA: THE WONDER FOOD OF THE 21ST CENTURY

This article is about spirulina and how it can be used as a nutrient supplement, a therapeutic agent, trace metal supplement, antioxidant, pigments, enviroment protector and a source of enzymes.

Biological treatment of a contaminated gaseous emission from a paint and varnish plant—from laboratory studies to pilot‐scale operation

AbstractA Vapour‐Phase Bioreactor (VPB), namely a biotrickling filter, was scaled‐up and operated in‐situ for the treatment of gaseous emissions from a paint and varnish industrial plant. A microbial culture able to degrade the target compounds was enriched and a laboratory‐scale VPB was established in order to evaluate the treatment's performance. The VPB presented removal efficiencies higher than 90% when exposed to Organic Loads (OL) of ca 50 g h−1 m−3 of reactor. The VPB was exposed to dynamic conditions often found in‐situ (eg night and weekend shutdown periods) and showed a fast capacity to recover, with and without mineral medium recirculation. After a prolonged interruption period (10 months), the VPB was not able to cope with OL of ca 25 g h−1 m−3 of reactor and re‐inoculation was required in order to recover the treatment performance. The VPB also showed limited treatment when exposed to higher OL (ca 500 g h−1 m−3 of reactor). The VPB was then scaled‐up and a 3 m3 VPB was operated in‐situ, showing removal efficiencies higher than 50% when exposed to an OL of c 5 g h−1 m−3 of reactor, thus complying with current legal demands. The addition of a maintenance feed was shown to be a useful tool for VPB pilot‐scale operation when shutdown periods occurred. A factorial design of experiments was carried out, which allowed reduction to one‐tenth of the initial supply of the main mineral medium constituents, namely phosphate buffer, ammonium and magnesium salts, and also elimination of the metal supplement. Overall, the VPBs were shown to be robust equipment, being able to respond actively to dynamic treatment scenarios, particularly night and weekend shutdown periods. Copyright © 2003 Society of Chemical Industry

Mineral and trace metal supplement for use with synthetic diets based on comminuted chicken.

Earlier studies (Alexander et al., 1974; Lawson et al., 1977) suggested a suitable composition for a mineral and trace metal supplement for use with synthetic diets containing some natural food. Such a mixture has been evaluated in patients receiving a diet based on comminuted chicken and has been shown to be adequate. This conclusion was based on balance experiments measuring Zn, Cu, Mn, Fe, Ca, Mg, N, and P.

A new successful approach to trace metal therapy and its relevance to the aetiology of various skin disorders.

SummaryPatients with dermatitis herpetiformis, chronic prurigo of adults and bullous pemphigoid reported in this study have responded more effectively to their specific drug therapy if trace metal supplement were provided. A lesser dosage requirement or even final elimination of drugs like dapsone or corticosteroids, resulted. Most frequently, a zinc and magnesium mixture was prescribed, although zinc only or magnesium only mixture was given in some patients. The plasma zinc and plasma magnesium levels in these patients were frequently below normal or in the low normal range.

Evaluation of a new mineral and trace metal supplement for use with synthetic diets.

In an earlier study (Alexander et al., 1974) it was shown that the mineral mixture used in association with a synthetic diet was deficient in zinc, copper, iron, and manganese. A new mixture containing appropriately increased amounts of these trace metals has now been evaluated by means of metabolic balance studies carried out on children with phenylketonuria. This new mixture was shown to be satisfactory for zinc, copper, and iron, but minor changes have been recommended for manganese.

Controlled Trial of D-Penicillamine in Rheumatoid Arthritis: Dose Effect and the Role of Zinc

The findings are reported of a controlled clinical trial comparing in 66 rheumatoid arthritis patients 0 g (placebo), and 0.50 g a day and 1 g a day of penicillamine. Each of these groups has been subdivided into two, one part receiving 5 mg a day of zinc metal supplement, the other a placebo. The trial was planned to be double-blind, and for each patient to take part for 4 months. The results prove the effectiveness of penicillamine in rheumatoid arthritis. 0.50 g a day has the same effect as 1 g a day but gives less side effects. Zinc supplement inhibits the clinical effects of penicillamine but does not prevent the side effects.