scholarly journals L-asparaginases of extremophilic microorganisms in biomedicine

2020 ◽  
Vol 66 (2) ◽  
pp. 105-123
Author(s):  
M.V. Dumina ◽  
M.A. Eldarov ◽  
D.D. Zdanov ◽  
N.N. Sokolov
Keyword(s):  
Food Industry ◽  
Biomedical Application ◽  
Lymphoblastic Leukemia ◽  
Kinetic Properties ◽  
Lymphoproliferative Diseases ◽  
Ph Tolerance ◽  
Physiological Properties ◽  
Extremophilic Microorganisms ◽  
Extreme Cold

L-asparaginase is extensively used in the treatment of acute lymphoblastic leukemia and several other lymphoproliferative diseases. In addition to its biomedical application, L-asparaginase is also of prospective use in food industry to reduce the formation of acrylamide, which is classified as probably neurotoxic and carcinogenic to human, and in biosensors for determination of L-asparagine level in medicine and food chemistry. The importance of L-asparaginases in different fields, disadvantages of commercial ferments, and the fact that they are widespread in nature stimuli the search for biobetter L-asparaginases from new producing microorganisms. In this regard, extremofile microorganisms exhibit unique physiological properties such as thermal stability, adaptability to extreme cold conditions, salt and pH tolerance and so provide one of the most valuable sources for novel L-asparaginases. The present review summarizes the recent results on studying the structural, functional, physicochemical and kinetic properties, stability of extremophilic L-asparaginases in comparison with their mesophilic homologues.

Characterization of Different Types of Biomass Wastes Using Thermogravimetric and ICP-MS Analyses

2020 ◽  
Vol 70 (12) ◽  
pp. 4594-4600
Keyword(s):  
Thermogravimetric Analysis ◽  
Food Industry ◽  
Wood Waste ◽  
Biomass Ash ◽  
Minor Elements ◽  
Ms Analysis ◽  
Icp Ms ◽  
Different Types

The purpose of this study was to characterize some types of biomass wastes resulted from different activities such as: agriculture, forestry and food industry using thermogravimetric and ICP-MS analyses. Also, it was optimized an ICP-MS method for the determination of As, Cd and Pb from biomass ash samples. The ICP-MS analysis revealed that the highest concentration of metals (As, Cd, Pb) was recorded in the wood waste ash sample, also the thermogravimetric analysis indicated that the highest amount of ash was obtained for the same sample (26.82%). The biomass wastes mentioned in this study are alternative recyclable materials, reusable as pellets and briquettes. Keywords: ash, biomass, ICP-MS, minor elements, TG

scholarly journals Gating Competence of Constitutively Open CLC-0 Mutants Revealed by the Interaction with a Small Organic Inhibitor

2003 ◽  
Vol 122 (3) ◽  
pp. 295-306 ◽  
Author(s):  
Sonia Traverso ◽  
Laura Elia ◽  
Michael Pusch
Keyword(s):  
Chloride Channels ◽  
Bound State ◽  
Side Chain ◽  
Pore Channel ◽  
Kinetic Properties ◽  
Wild Type ◽  
High Affinity ◽  
Critical Residue ◽  
Fast Gating

Opening of CLC chloride channels is coupled to the translocation of the permeant anion. From the recent structure determination of bacterial CLC proteins in the closed and open configuration, a glutamate residue was hypothesized to form part of the Cl−-sensitive gate. The negatively charged side-chain of the glutamate was suggested to occlude the permeation pathway in the closed state, while opening of a single protopore of the double-pore channel would reflect mainly a movement of this side-chain toward the extracellular pore vestibule, with little rearrangement of the rest of the channel. Here we show that mutating this critical residue (Glu166) in the prototype Torpedo CLC-0 to alanine, serine, or lysine leads to constitutively open channels, whereas a mutation to aspartate strongly slowed down opening. Furthermore, we investigated the interaction of the small organic channel blocker p-chlorophenoxy-acetic acid (CPA) with the mutants E166A and E166S. Both mutants were strongly inhibited by CPA at negative voltages with a >200-fold larger affinity than for wild-type CLC-0 (apparent KD at −140 mV ∼4 μM). A three-state linear model with an open state, a low-affinity and a high-affinity CPA-bound state can quantitatively describe steady-state and kinetic properties of the CPA block. The parameters of the model and additional mutagenesis suggest that the high-affinity CPA-bound state is similar to the closed configuration of the protopore gate of wild-type CLC-0. In the E166A mutant the glutamate side chain that occludes the permeation pathway is absent. Thus, if gating consists only in movement of this side-chain the mutant E166A should not be able to assume a closed conformation. It may thus be that fast gating in CLC-0 is more complex than anticipated from the bacterial structures.

scholarly journals The Outcome of Children With Acute Lymphoblastic Leukemia Without Receiving Sufficient Dose of L-Asparaginase

2020 ◽  
Author(s):  
Gholamreza Bahoush ◽  
Gholamreza Bahoush ◽  
Marzieh Nojomi
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Hypersensitivity Reaction ◽  
Lymphoblastic Leukemia ◽  
Accurate Determination ◽  
Drug Regimen ◽  
Disease Recurrence ◽  
Free Survival ◽  
Complete Treatment

In acute lymphoblastic leukemia (ALL) patients treated with L-asparaginase, discontinuation of the drug occasionally occur due to severe drug complications or resistance, however, due to the high efficacy of this drug in the recovery of patients and the prevention of disease recurrence, resuming the drug regimen is preferred in most patients. What we did in this study was to evaluate and compare the effects of clinical outcomes in the two modes of continuing and discontinuing drug use. In this retrospective cohort study, all children with ALL who had been treated with L-asparaginase during the years 2005 to 2015 were included in the study and categorized into two groups receiving complete treatment regimen (n=160) and those who had to discontinue the drug due to appearing complications (n=9). The rate of relapse and mortality rate was determined and compared across the two groups with a median follow-up time of more than 5 years. 5-yrs Overall survival of all enrolled patients in the groups continued and discontinued was 91.4±2.5% and 71.4±17.1%, respectively (P=0.792). Also, 5-yrs event-free survival of the two groups was 75.8±3.5% and 71.4±17.1%, respectively (P=0.557. Relapse was revealed in 17.5% and 33.3% respectively and mortality in 16.9% and 0.0% (P=0.261). However, the overall prevalence of hypersensitivity reaction to the drug was significantly higher in those patients who discontinued their drug regimen (100% versus 24.4%, P<0.001). Hypersensitivity reaction to drugs may be an important factor in discontinuing L-asparaginase in patients with ALL. The discontinuation of L-asparaginase supplementation due to various complications such as hypersensitivity reactions may be effective in the survival of these patients. However, accurate determination of the effect of discontinuation of this drug on the outcome of children with ALL requires a more comprehensive study with more complicated cases.

Determination of uronic acids in sugarcane bagasse by anion-exchange chromatography using an electrode modified with copper nanoparticles

2015 ◽  
Vol 7 (6) ◽  
pp. 2347-2353 ◽  
Author(s):  
Maísa Azevedo Beluomini ◽  
José Luiz da Silva ◽  
Nelson Ramos Stradiotto
Keyword(s):  
Anion Exchange ◽  
Sugarcane Bagasse ◽  
Copper Nanoparticles ◽  
Food Industry ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Lignocellulosic Materials ◽  
Uronic Acids

Uronic, d-glucuronic and d-galacturonic acids are found in lignocellulosic materials and are known to be used in the food industry and chemical industries.

Relevance of Specific Immunoglobulin M and Immunoglobulin G for Parvovirus B19 Diagnosis in Patients With Acute Lymphoblastic Leukemia Receiving Chemotherapy: Prospective Study

2007 ◽  
Vol 131 (11) ◽  
pp. 1697-1699
Author(s):  
Maysaa El Sayed Zaki
Keyword(s):  
Bone Marrow ◽  
Immune Response ◽  
Acute Lymphoblastic Leukemia ◽  
Parvovirus B19 ◽  
Lymphoblastic Leukemia ◽  
Healthy Children ◽  
Immunocompromised Patients ◽  
Humoral Immune ◽  
Specific Immunoglobulin

Abstract Context.—Immunocompromised patients suffer from prolonged viral infections often without detectable immune response. However, even if the immune response occurs, can it clear the virus completely? Objective.—To detect parvovirus B19 DNA and its antibodies in bone marrow cells and in serum by polymerase chain reaction (PCR) in children with acute lymphoblastic leukemia receiving chemotherapy to highlight the relation of humoral immune response to the presence of viremia. Also, to evaluate the optimal diagnostic test(s) for a correct diagnosis of parvovirus B19 disease in immunocompromised patients. Design.—Forty-eight children with acute lymphoblastic leukemia receiving maintenance chemotherapy were included in the study in addition to 20 healthy children with matched age and sex. Study for parvovirus B19 was performed by serologic determination of specific immunoglobulin (Ig) M and IgG, and viral DNA was determined by PCR in both serum and bone marrow aspiration. Results.—Parvovirus B19 DNA was detected in both serum and bone marrow in 20% of patients. Specific IgG was found in 40% and IgM in 26.7%. Two cases (10%) in the control group were positive for IgG. The agreement between IgG and positive results of PCR in the bone marrow was 33.3%, and the agreement for IgM and PCR in the serum was 33.3%. Conclusions.—Parvovirus B19 is considered a common viral infection in children with acute lymphoblastic leukemia receiving chemotherapy. We must use our full potential to exclude such infection, which can mimic the side effects of chemotherapy in these patients. In immunocompromised patients, there are immunologic discrepancies in humoral immune responses for both IgM and IgG between individuals with parvovirus B19 persistence and healthy individuals, findings that may reflect both failed immunity and antigenic exhaustion. The contemporaneous determination of parvovirus B19 DNA by PCR in both bone marrow and peripheral blood and specific serologic markers appears to be the most appropriate diagnostic protocol for the correct laboratory diagnosis of parvovirus B19 infection in these patients.

Study of Histamine Detection using Liquid Chromatography and Gas Chromatography

2021 ◽  
Vol 16 ◽  
pp. 1-9
Author(s):  
Muhammad Abdurrahman Munir ◽  
Muhammad Mukram Mohamed Mackeen ◽  
Lee Yook Heng ◽  
Khairiah Haji Badri
Keyword(s):  
Gas Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Food Industry ◽  
Hplc Analysis ◽  
Hplc Method ◽  
Chromatography Analysis ◽  
Quantitation Limit ◽  
Satisfactory Recovery

Histamine is a heterocyclic amine shaped by decarboxylation of the histidine. It is a compound that lack chromophore and involatile. However, the detection of histamine is imperative due to the characteristic of histamine has given several disadvantages in food industry. This paper describes methods for histamine detection by employing high performance liquid chromatography and gas chromatography. The derivatization techniques required for both methods in order to increase the sensitivity of chromatography analysis. Two derivatizing agents were applied in this study such as 9-flourenilmethyl chloroformate (FMOC – Cl) for HPLC analysis whereas for GC analysis a N,O-bis (trimethylsilyl)acetamide (BSA) was used. Method validation was in accordance to Commission Decision 657/2002/CE. The validation of specificity, linearity, precision, accuracy, detection limit and quantitation limit results indicate that the methods were acceptable. The linear range for both methods were at 0.16 – 5.00 µg∙mL-1. The determination of histamine using GC showed the superiority of this instrument compared to HPLC. Method applicability was also checked on real sample namely mackerel in order to acquire a satisfactory recovery for both methods.

Determination of Nanomaterials in the Food Industry: An Approach to Safety and Quality

2021 ◽  
pp. 114-121
Author(s):  
L. Gobbi ◽  
L. Mancini ◽  
R. Ruggieri ◽  
M. Tiradritti ◽  
G. Vinci
Keyword(s):  
Food Industry

Characterization of microneedles and microchannels for enhanced transdermal drug delivery

2021 ◽  
Author(s):  
Ashana Puri ◽  
Hiep X Nguyen ◽  
Akeemat O Tijani ◽  
Ajay K Banga
Keyword(s):  
Transdermal Delivery ◽  
Transdermal Drug Delivery ◽  
Review Paper ◽  
Low Molecular Weight ◽  
Kinetic Properties ◽  
Different Types ◽  
And Performance ◽  
Tools And Techniques

Microneedle (MN)-based technologies are currently one of the most innovative approaches that are being extensively investigated for transdermal delivery of low molecular weight drugs, biotherapeutic agents and vaccines. Extensive research reports, describing the fabrication and applications of different types of MNs, can be readily found in the literature. Effective characterization tools to evaluate the quality and performance of the MNs as well as for determination of the dimensional and kinetic properties of the microchannels created in the skin, are an essential and critical part of MN-based research. This review paper provides a comprehensive account of all such tools and techniques.

Anthropometric and Physiological Properties in the Determination of Biological Distances

1979 ◽  
Vol 29 (2) ◽  
pp. 77-81 ◽  
Author(s):  
P. Rudan ◽  
Milica Gomzi ◽  
Eugenija &Zcaron;u&scaron;ki ◽  
M. &Scaron;ari&cacute;
Keyword(s):  
Physiological Properties
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