Concentrations Of Zinc Sulfate Research Articles

The level of free intracellular zinc mediates programmed cell death/cell survival decisions in plant embryos.

Zinc is a potent regulator of programmed cell death (PCD) in animals. While certain, cell-type-specific concentrations of intracellular free zinc are required to protect cells from death, zinc depletion commits cells to death in diverse systems. As in animals, PCD has a fundamental role in plant biology, but its molecular regulation is poorly understood. In particular, the involvement of zinc in the control of plant PCD remains unknown. Here, we used somatic embryos of Norway spruce (Picea abies) to investigate the role of zinc in developmental PCD, which is crucial for correct embryonic patterning. Staining of the early embryos with zinc-specific molecular probes (Zinquin-ethyl-ester and Dansylaminoethyl-cyclen) has revealed high accumulation of zinc in the proliferating cells of the embryonal masses and abrupt decrease of zinc content in the dying terminally differentiated suspensor cells. Exposure of early embryos to a membrane-permeable zinc chelator N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine led to embryonic lethality, as it induced ectopic cell death affecting embryonal masses. This cell death involved the loss of plasma membrane integrity, metacaspase-like proteolytic activity, and nuclear DNA fragmentation. To verify the anti-cell death effect of zinc, we incubated early embryos with increased concentrations of zinc sulfate. Zinc supplementation inhibited developmental PCD and led to suppression of terminal differentiation and elimination of the embryo suspensors, causing inhibition of embryo maturation. Our data demonstrate that perturbation of zinc homeostasis disrupts the balance between cell proliferation and PCD required for plant embryogenesis. This establishes zinc as an important cue governing cell fate decisions in plants.

Characteristics of Pulse Deposited CdZnSe Films

CdZnSe films were pulse deposited using aqueous solutions of AR grade cadmium sulphate, zinc sulphate and selenium di oxide.To get different compositions of the ternary films, concentrations of Cadmium and zinc sulphate were varied. The films exhibited hexagonal structure after heat treatment. The band gap of the films varied in the range of 1.72 - 2.70 eV as the composition of the films changed from CdSe to ZnSe side.XPS studeis also confirmed the formation of CdZnSe. I-V characteristics of the films were studied. Laser Raman studies indicated LO and TO modes depending on the composition of the films.

Influence of Zn2+, Co2+ and dimethylbenzimidazole on vitamin B12 biosynthesis by Pseudomonas denitrificans

Previous research has confirmed that cobalt ion and dimethylbenzimidazole (DMBI) are the precursors of vitamin B12 biosynthesis, and porphobilinogen synthase (PBG synthase) is a zinc-requiring enzyme. In this paper, the effects of Zn2+, Co2+ and DMBI on vitamin B12 production by Pseudomonas denitrificans in shake flasks were studied. Present experimental results demonstrated that the addition of the above mentioned three components to the fermentation medium could significantly stimulate the biosynthesis of vitamin B12. The concentrations of zinc sulphate, cobaltous chloride and DMBI in the fermentation medium were further optimized with rotatable orthogonal central composite design and statistical analysis by Data Processing System (DPS) software. As a result, vitamin B12 production was increased from 69.36 ± 0.66 to 78.23 ± 0.92 μg/ml.

Prevalence of Intestinal Parasites and Associated Risk Factors among Schoolchildren in Srinagar City, Kashmir, India

Surveys on the prevalence of various intestinal parasitic infections in different geographic regions is a prerequisite for developing appropriate control strategies. The aim of the present study was to determine the prevalence of intestinal parasitic infections in schoolchildren enrolled in various schools in Srinagar City, Kashmir, India, and to assess epidemiological factors associated with the extent of endemic disease. Stool samples were collected from 514 students enrolled in 4 middle schools. The samples were processed with the use of both simple smear and zinc sulphate concentration methods, and then microscopically examined for intestinal parasites. Of the 514 students surveyed, 46.7% had 1, or more, parasites. Prevalence of Ascaris lumbricoides was highest (28.4%), followed by Giardia lamblia (7.2%), Trichuris trichiura (4.9%), and Taenia saginata (3.7%). Conditions most frequently associated with infection included the water source, defecation site, personal hygiene, and the extent of maternal education. The study shows a relatively high prevalence of intestinal parasites and suggests an imperative for the implementation of control measures.

The effect of lead and zinc concentrations on the growth of four species of bryophytes.

Studies have been made on the morphological and physiological changes that occurred in four bryophyte taxa, namely, Riccia crystalina, Timmiella barbuloides, Hyophila involuta and Physcomitrium repandum in response to the various concentrations of two heavy metals, i.e. zinc and lead. Effect of different concentrations of lead nitrate and zinc sulphate on various parameters was studied at regular intervals on different plants since the amount, duration, intensity of precipitation and plant species affect accumulation of heavy metal. The plants showed reduced number of regenerants and retarded growth when exposed to >0.5 ppm concentration of metals. At higher concentration and exposure for longer duration, the plants lost the chlorophyll content. Effect of Lead nitrate on various parameters was found to be more drastic than Zinc sulphate in most of the cases except in T. barbuloides. The uptake efficiency of the most common heavy metals in mosses follows mostly the order: Pb > Co, Cr > Cu, Cd, Mo, Ni, V > Zn > As. © 2007 International Formulae Group. All rights reserved. International Journal of Biological & Chemical Sciences Vol. 1 (2) 2007: pp. 128-135

Process aspects of electroless deposition for nickel–zinc–phosphorous alloys

AbstractElectroless deposition of Ni–Zn–P thin film was considered as a barrier film on a galvanic Zn or Ni–Zn sacrificial layer in a multicomponent corrosion protective coating on steel. The incorporation of zinc on the chemical composition of electroless Ni–Zn–P coating was studied. The effect of operating conditions such as temperature, pH value and concentration of zinc sulphate was investigated. Some physical characteristics such as morphology, structure, corrosion properties of Ni–Zn–P coatings were assessed in parallel with those of Ni–P. Inclusion of Zn to Ni–P is accompanied by the transformation of the coating structure from amorphous to crystalline. The effect of adding nonionic surfactant to the plating solution on the composition and surface morphologies was also investigated. The results indicate that nonionic surfactant has no effect on the Zn % in the deposit layer, but it affects the surface morphology and improves the corrosion resistance of Ni–Zn–P layers. Copyright © 2005 John Wiley & Sons, Ltd.

Separation of H 2SO 4 + ZnS0 4 mixture by diffusion dialysis

Dialysis of an aqueous solution ofH 2SO 4 + ZnSO 4 was investigated in a two-compartment cell with an anion-exchange membrane, Neosepta-AFN. The experiments proved that sulfuric acid permeates well through the membrane while zinc sulfate was efficiently rejected. This operation is very effective at high acid concentrations and low concentrations of zinc sulfate. The flux of ZnSO 4 calculated from the time dependencies of the ZnSO 4 concentration was negatively influenced by increasing acid concentration. It was demonstrated that (1) the ZnSO 4 concentration in the membrane decreased with increasing acid concentration and (2) at the same time, the concentrations of zinc complexes bearing negative charges also decreased.

Effect of metal mixtures (Cd and Zn) on body weight in terrestrial isopods.

The aim of this study was to determine the effect of exposure to cadmium and zinc mixtures on the weight of terrestrial isopods. Experiments were conducted using uncontaminated specimens of P. laevis. The isopods were exposed to various concentrations of cadmium and zinc sulfate in single- and mixed-metal experiments. The mean weight of the unexposed isopods in the control group increased over the 6 weeks of observation. It was concluded that cadmium and zinc, administered separately, had a negative effect on the weight of P. laevis. The weight change (gain or loss) of P. laevis in the exposures to mixtures of cadmium and zinc sulfate were different from those of woodlice where Cd and Zn were administered separately. Combination of the lowest concentrations of Cd and Zn (20 and 1000 mg x kg(-1)) produced a stimulating effect compared to the control. Weight changes of the other two combinations of Cd and Zn (80/4000 and 160/8000 mg x kg(-1)) showed no differences from those of the control, and weight changes of woodlice exposed to Cd and Zn mixtures were mostly the same as those of the control over the 6-week exposure period. It can thus be concluded that mixtures of Cd and Zn have an antagonistic effect on each other in terms of weight of P. laevis.

Growth Inhibition of Enteric Pathogens by Zinc Sulfate: An in vitro Study

Objective: To determine the inhibition effect of zinc sulfate on isolates of enteric bacteria. Materials and Methods: Mueller-Hinton agar containing different concentrations of zinc sulfate was prepared. Isolates used in this study were obtained from local clinics. They were Salmonella typhi, Salmonella groups A, B, C, D and E, Escherichia coli, Enterobacter, Shigella and Vibrio cholerae. Overnight cultures of test organisms in brain-heart infusion broth were adjusted to 0.5 McFarland standard turbidity by adding normal saline with 1 µl of each adjusted broth culture inoculated onto zinc sulfate agar plates. The plates were incubated for 18–20 h at 37°C. The inhibition concentration was recorded as the lowest concentration of zinc sulfate that completely inhibited growth. Results: All enteric pathogens tested were inhibited by zinc sulfate. Of the isolates, S. typhi was most sensitive since 20% of the strains were inhibited by zinc sulfate of 0.8 mg/ml. Salmonella paratyphi A was inhibited at 1.2 mg/ml. Other Salmonella spp. were inhibited at concentrations between 1.4 and 2.0 mg/ml. V. cholerae O1 and Shigella flexneri demonstrated a similar pattern of inhibition as S. paratyphi A. A higher concentration of zinc sulfate (1.6 mg/ml) was required to completely inhibit Shigella sonnei. Conclusion: The findings indicate that zinc sulfate has an antimicrobial effect on enteric pathogens and may contribute to the treatment of diarrhea.

Evaluation of cytological effects of Zn 2+ in relation to germination and root growth of Nigella sativa L. and Triticum aestivum L.

The effects of different treatments with zinc sulfate (Zn 2+) on the cytology and growth of Nigella sativa and Triticum aestivum were investigated. Five concentrations of zinc sulfate ranging from 5 to 25 mg/l were applied for 6, 12, 18, and 24 h. The treatments reduced the germination percentages of N. sativa seeds and T. aestivum grains and inhibited the root growth of both plants. Concentrations higher than 25 mg/l of Zn 2+ applied for 24 h were toxic for both plants. The non-lethal concentrations of Zn 2+ showed an inhibitory effect on cell division in root tips of both plants and caused a decrease in their mitotic index values. The reduction in MI in root tips of T. aestivum was more evident than that of N. sativa. All treatments changed the frequency of mitotic phases as compared with the control values. The total percentage of abnormalities in N. saliva was more than that in T. aestivum. Zn 2+ treatments produced a number of mitotic abnormalities in dividing cells in root tips of both plants resulting from its action on the spindle apparatus such as C-metaphases, lagging chromosomes and multipolar anaphases and telophases. Also, Zn 2+ induced vacuolated nuclei and irregular prophases. The induction of chromosomal stickiness and chromosomal aberrations such as bridges and breaks indicates its action on the chromosome. These abnormalities (chromosome breaks and chromosomal bridges at ana–telophases) indicate true clastogenic potential of the ions tested.

Insulin containing polyethylenimine–dextran sulfate nanoparticles

An aqueous nanoparticle delivery system has been developed which employs the oppositely charged polymers polyethylenimine (PEI) and dextran sulfate (DS) with zinc as a stabilizer. It is found that the pH of PEI solutions, the weight ratio of the two polymers, and zinc sulfate concentrations all play significant roles in controlling particle size. Spherical particles of 250 nm mean diameter were produced under optimal conditions which have a zeta potential of approximately +30 mV. Up to 90% drug entrapment efficiency was observed when insulin was used as a model protein drug. No degradation products were detected during in vitro dissolution or in potency studies. Circular dichroism (CD) spectra showed no significant conformational changes compared to free insulin under optimized formulation conditions. Rapid release characteristics were observed in in vitro dissolution studies. Biological activity in steptozotocin-induced diabetic rats, however, exhibited a prolonged hypoglycemic effect. This system offers the following advantages: (1) ease of manufacturing under mild preparation conditions; (2) employment of completely aqueous processing conditions; (3) use of biocompatible polymers which can be prepared aseptically; (4) ability to control particle size; (5) a high level of drug entrapment and (6) an ability to preserve protein secondary structure and biological activity.

Direct protection of inosine on PC12 cells against zinc-induced injury.

It has been reported that inosine has no direct neuroprotection against respiratory inhibitors due to the absence of purine nucleoside phosphorylase in neurons. Recent evidence, however, has shown that inosine has direct neurotrophic effects. Thus, lack of direct neuroprotection, as reported before, may not be a general conclusion, but is related to special types of injury. We used PC12 cells to explore direct neuroprotection of inosine against high concentration of zinc sulfate, an injury different from the previous one and found that inosine reduced the mortality of PC12 cells significantly in a dose dependent manner. The results indicate that inosine can directly protect neurons from zinc-induced injury, and such effect might be mediated via mechanism(s) other than purine nucleoside phosphorylase.

Slow release rubber formulations containing ZnSO 4

Styrene butadiene (SBR) and natural rubber (NR) can be used as binding matrices to control the release of zinc (Zn) which is a micro-nutrient for plants. The leaching rate of zinc in an aqueous medium depends on the concentration of zinc sulphate loaded in the two types of rubber used, the temperature of the surrounding environment and the pH of the aqueous medium. Water uptake was increased with increasing concentration of ZnSO 4. The sustained release of zinc ions from the investigated formulations was prolonged for over five months. The mechanical properties of the vulcanizates were affected as the concentration of zinc sulphate changed.

Zinc alloy plating

Substrate protection coatings are widely applied in the industry. Zn–Ni alloys have less potential for corrosion, thus preserving the steel substrate by corroding first. In this sense, this study used nickel-rich electroplating industry wastewater to produce Zn–Ni alloys under different conditions, analyzing the zinc sulfate concentration, electric current density, and rotating cathode in the deposition. The nickel removal kinetics showed a reversible and first-order behavior. The alloys with a composition of 2 wt.% nickel, according to energy-dispersive X-ray spectroscopy analysis, were more anti-corrosive with polarization resistance of 1276.7 Ω cm2, than the alloys containing 5 wt.% nickel. Electrochemical impedance spectroscopy proved that alloys containing 2 wt.% nickel were more resistant to corrosion and indicated the formation of a porous oxide layer. Besides, the micrographs of the alloys containing 2 wt.% nickel showed homogeneity without cracks and nodular grains, unlike the alloys with 5 wt.% nickel, which had cracks and were heterogeneous. The X-ray diffraction diffractograms showed different structures according to the amount of Ni. Thus, the deposition of metals from wastewater is an alternative to conventional treatments and avoids the use of synthetic baths.

Formulation and characterization of amphotericin B–polyethylenimine–dextran sulfate nanoparticles

A new aqueous nanoparticle system has been developed using complex coacervation employing the oppositely charged polymers polyethylenimine (PEI) and dextran sulfate (DS), with zinc sulfate as a stabilizing agent. Amphotericin B (AmB) was loaded into the nanoparticles as a model drug. The nanoparticles contained PEI and DS in the weight ratio of ∼1:2. They possessed a zeta potential of approximately +30 mV and demonstrated a narrow size distribution in the range 100–600 nm with a polydispersity index of 0.2. Electron microscopy revealed spherical nanocapsules with a smooth surface. Very favorable drug entrapment and recovery efficiencies of up to 85% were routinely observed. Processing parameters, such as the pH of the PEI solutions, ratio of the two polymers, as well as the concentrations of DS and zinc sulfate, all played a significant role in controlling particle size. Dissolution studies demonstrated a fast release that is dependent on the model drug solubility. The AmB‐loaded nanoparticles displayed no toxicity in tissue culture in contrast to free drug and were almost as efficacious as free drug in killing Candida albicans. Advantages of this simple technique are (1) ease of manufacturing and mild preparation conditions, (2) employment of completely aqueous processing conditions, (3) use of biocompatible polymers that can be prepared aseptically, (4) ability to control their size, and (5) a high level of drug entrapment. © 2001 Wiley‐Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 90:902–914, 2001

Concerted action of antioxidant enzymes and curtailed growth under zinc toxicity in Brassica juncea

Investigations were carried out to study the enzymatic detoxification of high concentration of oxygen species in shoots of Brassica juncea (Brassicaceae) seedlings raised on mineral growth medium with various concentrations of zinc sulphate (0.007, 0.05, 5 and 10 mM). Zinc at 0.05 mM promoted growth of seedlings, but at 5 and 10 mM caused significant reduction in growth. Moreover, zinc at and above 5 mM brought over 2.5-fold enhancement in malondialdehyde content (an index of lipid peroxidation) over that of control, indicating that free radical generation was accelerated in plants exposed to toxic levels of zinc. The shoots of seedlings raised in the presence of toxic levels of zinc showed an enzyme-specific increase in the activities of superoxide dismutase (EC 1.15.1.1), catalase (EC 1.11.1.6), guaiacol peroxidase (EC 1.11.1.7), ascorbate peroxidase (EC 1.11.1.11), monodehydroascorbate reductase (EC 1.6.5.4), dehydroascorbate reductase (EC 1.8.5.1) and glutathione reductase (EC 1.6.4.2). Concentrations of both ascorbate and glutathione were significantly enhanced in seedlings raised at toxic levels of zinc. These results suggest that B. juncea seedlings try to counteract high concentrations of oxygen species produced under zinc toxicity through a co-ordinated increase in the activities of enzymes involved in their detoxification.

Efficacy of a drug combination of praziquantel, pyrantel pamoate, and febantel against giardiasis in dogs

Abstract Objective To evaluate efficacy of a combination of praziquantel, pyrantel pamoate, and febantel at 2 dosages for treating naturally acquired giardiasis in dogs. Animals 6 male and 9 female Beagles. Procedure Dogs were identified as naturally infected with Giardia sp, using the zinc sulfate concentration technique (ZSCT), and were allocated to 1 of 3 groups. Group-1 dogs were treated orally with a praziquantel (5.4 to 7 mg/kg of body weight), pyrantel pamoate (26.8 to 35.2 mg/kg), and febantel (26.8 to 35.2 mg/kg) combination, every 24 hours for 3 doses. Group-2 dogs were treated with the combination once. Group-3 dogs were nontreated controls. Four fecal samples were examined, using the ZSCT, from each dog of each group within 6 days of the last treatment. Dogs were considered to have giardiasis if 1 or more of the fecal samples had positive results for Giardia cysts. Dogs were examined daily for at least 10 days after the last treatment. Results Giardia cysts were not detected in the feces of any group-1 dog or in the feces of 2 of 5 group- 2 dogs. Cysts were detected in the feces of 5 of 5 group-3 (nontreated control) dogs. Signs of toxicosis were not observed in any dog. Conclusion and Clinical Relevance The current labeled dose (for treatment of various nematodes and cestodes, but not Giardia sp) of the combination given orally once reduces cyst excretion in Giardia-infected dogs, and should be considered for treatment of dogs shedding Giardia cysts, whether or not they have clinical signs of infection. (Am J Vet Res 1998; 59:1134-1136)

The effect of zinc ions on the activity of metallo-beta-lactamases of Bacteroides fragilis.

The zinc supplement required to achieve the maximum activity of metallo-beta-lactamases from 12 Bacteroides fragilis isolates was investigated. Changes in absorbance of imipenem in a spectrophotometric assay with crude cell extracts were performed in the presence and absence of various concentrations of zinc sulphate. The greatest degree of imipenem hydrolysis was seen with the addition of between 50 and 500 microM zinc sulphate, and the degree of stimulation of enzyme activity in the strains tested varied six-fold. Increasing the zinc sulphate concentration resulted in inhibition of hydrolysis with extracts of low enzymic activity. These findings indicate the importance of determining the optimal zinc concentration for each strain tested in kinetic studies of metallo-beta-lactamases.

Increased expression of Gs(alpha) enhances activation of the adenylyl cyclase signal transduction cascade.

Expression of the stimulatory G protein, G(S)alpha, can vary over a 3-fold range in human tissues and in rodent central nervous system. In fact, the offspring of alcoholics have higher levels of G(S)alpha expression in certain tissues compared with the offspring of nonalcoholics. The aim of this research was to test the hypothesis that a causal relationship exists between the level of expression of G(S)alpha and induction of the adenylyl cyclase (AC) cascade. The methodology employed transient transfection of HEK 293 cells with a cDNA for the 52-kDa form of G(S)alpha under regulation by inducible metallothionein promoters. Transfectants were exposed to varying concentrations (0-125 microM) of zinc sulfate that produced a 3-fold range of membrane G(S)alpha expression. The range of G(S)alpha expression produced was found to mimic a physiologically relevant spectrum of G(S)alpha expression in membranes derived from human tissues and rat brain. It was observed that induction of G(S)alpha expression increased constitutive as well as stimulated cAMP accumulation. Moreover, induction of G(S)alpha expression increased events distal to the accumulation of cAMP including the phosphorylation of the transcription factor, cAMP response element binding protein and transcriptional activation of cAMP-dependent reporter genes. In summary, these studies show that the amount of G(S)alpha expression has a marked impact on the level of activity of the AC cascade from the membrane through to the nucleus. It is hypothesized that individuals who differ in G(S)alpha expression may also differ in the expression of certain cAMP-dependent genes.

Tolerance to cadmium cytotoxicity is induced by zinc through non-metallothionein mechanisms as well as metallothionein induction in cultured cells

To investigate the relationship between metallothionein induction and zinc-induced tolerance to cadmium cytotoxicity at the cell level, Chang liver cells were pretreated with a wide range of concentrations of zinc sulfate and challenged with toxic levels of cadmium after removal of zinc. It was found that zinc-pretreated cells were significantly resistant even when the extracellular level of zinc was low and metallothionein was not induced by the metal. Pretreatment with zinc resulted in a lesser accumulation of cadmium and metallothionein after challenge with cadmium. In porcine kidney LLC-PK 1 cells and bovine aortic smooth muscle cells pretreated with low levels of zinc, the intracellular accumulation of cadmium was significantly less and cadmium-induced decrease in intracellular zinc was significantly prevented without a change of metallothionein content; as the result, the toxic effect of cadmium was significantly diminished. It was therefore concluded that a tolerance to cadmium cytotoxicity is induced by zinc via non-metallothionein mechanisms such as decreasing intracellular cadmium as well as metallothionein induction at the cell level. The non-metallothionein mechanism was postulated to be particularly importatnt when the extracellular concentration of zinc is under the threshold for metallothionein induction.