Neelam Verma

L-Asparaginase: A Promising Chemotherapeutic Agent

ABSTRACT This article comprises detailed information about L-asparaginase, encompassing topics such as microbial and plant sources of L-asparaginase, treatment with L-asparaginase, mechanism of action of L-asparaginase, production, purification, properties, expression and characteristics of l-asparaginase along with information about studies on the structure of L-asparaginase. Although L-asparaginase has been reviewed by , our effort has been to include recent and updated information about the enzyme covering new aspects such as structural modification and immobilization of L-asparaginase, recombinant L-asparaginase, resistance to L-asparaginase, methods of assay of L-asparagine and L-asparaginase activity using the biosensor approach, L-asparaginase activity in soil and the factors affecting it. Also, side-effects of L-asparaginase treatment in acute lymphoblastic leukemia (ALL) have been discussed in the current review. L-asparaginase has been and is still one of the most widely studied therapeutic enzymes by researchers and scientists worldwide.

Biosensors for heavy metals

A biosensor is an analytical device that consists of an immobilized biocomponent in conjunction with a transducer, and represents a synergistic combination of biotechnology and microelectronics. This review summarizes the use of biosensors for detecting and quantifying heavy metal ions. Heavy metal contamination is of serious concern to human health since these substances are non-biodegradable and retained by the ecological system. Conventional analytical techniques for heavy metals (such as cold vapour atomic absorption spectrometry, and inductively coupled plasma mass spectrometry) are precise but suffer from the disadvantages of high cost, the need for trained personnel and the fact that they are mostly laboratory bound. Biosensors have the advantages of specificity, low cost, ease of use, portability and the ability to furnish continuous real time signals. The analysis of heavy metal ions can be carried out with biosensors by using both protein (enzyme, metal-binding protein and antibody)-based and whole-cell (natural and genetically engineered microorganism)-based approaches.

A review on solid phase microextraction- : High performance liquid chromatography as a novel tool for the analysis of toxic metal ions

This paper reviews the practical applications of solid phase microextraction-High performance liquid chromatography in the analysis of toxic metal species as these are important contaminants and are carcinogenic. Their determination in formulations, in feed and food, and in complex environmental matrices (e.g., waste water and industrial effluents) often requires analytical methods capable of high efficiency, unique selectivity, and high sensitivity. Solid phase microextraction (SPME) requires low solvent consumption and is quick in use. SPME is used for extraction and online desorption of analytes with the mobile phase of HPLC and subsequent detection by UV, ICP-MS or ESI-MS as detectors. Different SPME-HPLC methods are summarized in this article to demonstrate the usefulness of this technique for metallic species of As, Cr, Pb, Hg and Se.

E. coli K-12 Asparaginase-Based Asparagine Biosensor for Leukemia

The present work aims at the development of a novel, diagnostic biosensor for monitoring asparagine levels in leukemia. Various immobilization strategies have been applied to improve the stability of the biocomponent (asparaginase). Response time studies have been carried out for different immobilization methods. Phenol Red indicator has been coimmobilized with asparaginase and color visualization approach has been optimized for various asparagine ranges. The detection limit of asparagine achieved with nitrocellulose membrane is 10−1 M, with silicon gel is 10−10–10−1 M, and with calcium alginate beads is 10−9–10−1 M. Furthermore, the calcium alginate bead system of immobilization has been applied for the asparagine range detection in normal and leukemia serum samples.

Fiber Optic Biosensor for the Detection of Cd in Milk

A novel absorption-transmission based, miniaturized fi ber optic biosensor has been developed for the detection of cadmium in milk. Biosensor constitutes Bacillus badius whole cells with phenol red as an indicator co-immobilized onto circular plastic discs with sol-gel approach and a fi ber optic transducer system. Inhibition of urease enzyme by cadmium ion has been used as bioassay principle in the study. The detection limit of 0.1 g/l has been achieved. Sample volume could be miniaturized to 10 l; miniaturization of sample volume to this level has never been cited in literature. Storage stability of biocomponent was found to be more than 90 days when stored at 4°C in 10% glycerol. Conclusively the study resulted in development of a quick, reliable, miniaturized biosensor with lower detection limit and longer storage stability.

Spectrophotometric determination of zinc bis-ethylenedithiocarbamate (zineb)

A spectrophotometric method has been developed for the determination of zineb by converting it into a molybdenum ethylenedithiocarbamate complex, which is then extracted into isobutyl methyl ketone and measured at 670 nm against a reagent blank. Beers law is obeyed over the zineb concentration range 2-40 mug/ml in the extract. The method is sensitive and can be used for determination of zineb in the presence of ziram, thiram or ferbam.

Bioscavenging of Cu(II) ions from aqueous solution with ricebran

Abstract The removal of copper ions from aqueous solution by ricebran as biosorbent was examined. Batch equilibration experiments conducted with alkali-treated ricebran showed 90·5% sorption within 1 h shaking at pH 7·2 with 100 ml of 50 ppm solution of Cu(II) ions and 1 g of ricebran. The Freundlich adsorption isotherm equation showed the measure of sorption capacity ( K ) to be 0·257.

A Bacillus sphaericus Based Biosensor for Monitoring Nickel Ions in Industrial Effluents and Foods

A microbial-based biosensor has been developed based on enzyme inhibition bioassay for monitoring the presence of Ni(II) in real-time samples. The sensing element is immobilized Bacillus sphaericus MTCC 5100 yielding urease enzyme. The transducer is an NH 4 + ion selective electrode in conjunction with a potentiometer. Heavy metals are potentially toxic to human beings. Nickel is associated with causing adverse health effects such as dermatitis and vertigo, in humans. Toxicity is manifested by affecting T-cell system and suppressing the activity of natural killer cells. Nickel finds applications in electroplating, coinage, electrodes, jewellery, alloys. The foods rich in Ni(II) are nuts, beans, oats, and wheat. The range of Ni(II) detection by the developed biosensor is 0.03–0.68 nM (0.002–0.04 ppb) with a response time of 1.5 minutes. For application, the Ni(II) effluent was procured from an electroplating industrial unit and was found to have a concentration of 100.0 ppm Ni(II). In foods, wheat flour sample was acid digested and Ni(II) was specifically complexed in the presence of other cations, and had an Ni(II) concentration of 0.044 ppm. The developed system has a reliability of 91.5% and 90.6%, respectively, for the samples and could possibly replace the existing conventional techniques of analysis.

Nature curing cancer – review on structural modification studies with natural active compounds having anti-tumor efficiency

Cancer treatment has raised many drugs and radiation therapies whose side-effects are visible. Ongoing research throughout the world for effective treatment mainly concentrates on methods either in the form of drugs or therapies against this lethal disease. However returning to ayurvedic roots enlightens the fact that nature has many efficient components with anti-cancerous, anti-proliferating and anti-angiogenesis effects. Evidences confirm the participation of plants extracts in synthesizing many medicines against already existing and even emerging diseases. Structure activity relationship (SAR) studies and structural modifications are helping in observing the basis of compounds characteristics to exhibit inhibitor’s nature against carcinogenic agents by modifying parent compounds for creating an improved and potent compound. Many components are under clinical trials but most of them still need attention. In this review an attempt has been made to focus on the natural components gifted by nature and even included in our diet with their structures and sources that could be supportive in designing drug either by computational methods or by experimental methods.

Plant asparaginase-based asparagine biosensor for leukemia

Abstract The present work aims at the development of plant asparaginase-based asparagine biosensor for leukemia. It is a novel diagnostic for monitoring asparagine levels in patients suffering from acute lymphoblastic leukemia (ALL). Various immobilization strategies have been applied to improve the stability of the asparaginase. The latest and updated information including some new techniques of immobilization related to L-asparaginase such as gelatin, agarose, agar, and calcium alginate methods are described in detail along with response time studies and comparative data. Furthermore these immobilization techniques have been applied for the detection of asparagine in normal and leukemia serum samples.