A qualitative study on barriers and strategies to hospital preparedness against chemical, biological, radiological, and nuclear incidents

BACKGROUND

The effects of chemical, biological, radiological, and nuclear (CBRN) incidents on human society can be irreparable. Preparing the health system for these incidents is essential. This study aims to identify obstacles to hospital preparedness against CBRN incidents and provide solutions.

MATERIALS AND METHODS

This qualitative study was conducted using semi-structured interview method in 2022. The research community included experts in the fields of CBRN, and 17 persons were included in the study through purposive sampling. The interviews were collected by interview guide and recorded face-to-face and online and were analyzed using thematic content analysis method in MS Word 2016.

RESULTS

The interviews' analysis was classified into two main categories and 34 sub-categories. Some of the most important obstacles to the hospital preparedness against CBRN incidents were the lack of proper crisis management, the lack of specialist staff, the stress of employees, the lack of turnover and sufficient rest for employees, legal gaps, and so on. The main strategies were determining the type and extent of the risk factor, strong crisis management, the lack of parallelism, continuous monitoring, having a protocol and road map, appropriate training programs, having skilled personnel, rapid response of personnel, positive attitude of the staff, and the favorable condition of the building.

CONCLUSION

The appointment of an expert in the field of CBRN and having a specialized unit, the existence of specialized and trained staff along with access to the required facilities, clear instructions, and intra-departmental and inter-departmental cooperation affect the readiness of hospitals against CBRN incidents.

Mutuality of epigenetic and nanoparticles: two sides of a coin

Nowadays nanoparticles (NPs) due to their multidimensional applications in enormous different fields, has become an exciting research topic. In particular, they could attract a noticeable interest as drug deliver with increased bioavailability, therapeutic efficacy and drug specificity. Epigenetic can be considered as a complex network of molecular mechanism which are engaged in gene expression and have a vital role in regulation of environmental effects on ethology of different disorders like neurological disorders, cancers and cardiovascular diseases. For many of them epigenetic therapy was proposed although its application accompanied with limitations, due to drug toxicity. In this review we evaluate two aspects to epigenetic in the field of NPs: firstly, the role of epigenetic in regulation of nanotoxicity and secondly application of NPs as potential carriers for epidrugs.

Antileishmanial effects and drugability characteristics of a heterocyclic copper complex: An in silico, in vitro and molecular study

Leishmaniasis caused by the protozoan Leishmania presents a severe illness, principally in tropical and subtropical areas. Antileishmanial metal complexes, like Glucantime®️ with proven activity, are routinely studied to probe their potency. We investigated the effects of a Cu (II) homoleptic complex coordinated by two dimethyl-bipyridine ligands against Leishmania major stages in silico and in vitro. The affinity of this heterocyclic Cu (II) complex (CuDMBP) towards a parasitic metacaspase was studied by molecular docking. Key pharmacokinetic and pharmacodynamic properties of the complex were predicted using three web-based tools. CuDMBP was tested for in vitro antileishmanial activities using MTT assay, model murine macrophages, flow cytometry, and quantitative real-time polymerase chain reaction (qPCR). Molecular docking confirmed the tendency between the target macromolecule and the complex. ADMET evaluations highlighted CuDMBP's key pharmacological features, including P-glycoprotein-associated GI absorption and lack of trans-BBB permeability. MTT showed significant inhibitory effects against promastigotes. CuDMBP significantly increased the level of cellular IL-12 expression (p < 0.05), while the upregulation observed in the expression of iNOS was considered not significant (p > 0.05). It decreased the expression of IL-10 significantly (p < 0.05). Findings demonstrated that CuDMBP deserves to be introduced as a leishmanicidal candidate provided further studies are carried out.

Innovative Diagnostic Peptide-Based Technologies for Cancer Diagnosis: Focus on EGFR-Targeting Peptides

Active targeting using biological ligands has emerged as a novel strategy for the targeted delivery of diagnostic agents to tumor cells. Conjugating functional targeting moieties with diagnostic probes can increase their accumulation in tumor cells and tissues, enhancing signal detection and, thus, the sensitivity of diagnosis. Due to their small size, ease of chemical synthesis and site-specific modification, high tissue penetration, low immunogenicity, rapid blood clearance, low cost, and biosafety, peptides offer several advantages over antibodies and proteins in diagnostic applications. Epidermal growth factor receptor (EGFR) is one of the most promising cancer biomarkers for actively targeting diagnostic and therapeutic agents to tumor cells due to its active involvement and overexpression in various cancers. Several peptides for EGFR-targeting have been identified in the last decades, which have been obtained by multiple means including derivation from natural proteins, phage display screening, positional scanning synthetic combinatorial library, and in silico screening. Many studies have used these peptides as a targeting moiety for diagnosing different cancers in vitro, in vivo, and in clinical trials. This review summarizes the progress of EGFR-targeting peptide-based assays in the molecular diagnosis of cancer.

Immobilization of Clostridium perfringens type D in calcium alginate beads: toxin production mimics free cell culture

Background and Objectives

Cell-immobilization is used to maintain microbial culture to produce metabolites in repeated-batch or continuous fermentations, thereby reducing the time and resources spent on delivering mass production of microbe. The technique also enables shortening of the detoxification phase and the amount of formaldehyde required due to low incidence of viable bacteria in the extract.

Materials and Methods

A solution of sodium alginate containing Clostridium perfringens cells was dropped into stirring CaCl solution via a sterile syringe needle. Optimizations resulted in reasonably uniform beads containing C. perfringens. Beads were externally stabilized by poly L-lysine, followed by immersion in a solution of Na-alginate to coat them with a new layer of alginate forming an alginate-PLL-alginate cortex.

Results

This study proved successful in immobilizing C. perfringens cells inside uniform alginate microspheres. Cell loading and cell propagation inside the beads were measured. The cell loaded beads were cultivable in liquid media producing 550 minimum lethal doses per milliliter (MLD/ml) in a 72 h.

Conclusion

The research paved the way for further investigations to optimize and establish an efficient bacterial encapsulation method. Thus, it seems possible to produce toxins from beads engulfing C. perfringens on larger scales via repeated-batch or continuous fermentation processes.

vB_EcoM_kmuOR AND vB_EcoM_kmuGH: TWO BROAD HOST RANGE COLIPHAGES EFFECTIVE AGAINST ESCHERICHIA COLI O157:H7 AND SHIGELLA FLEXNERI

E. coli O157:H7 is a foodborne pathogen mostly related to consumption of meat and vegetables. Although using antibiotics is not recommended in treatment of infections caused by this pathogen, antibiotic resistant isolates are reported. This has encouraged researchers to find alternative methods to treat and effective approaches to prevent the E. coli O157:H7 infections. Phage therapy is one of the techniques with therapeutic and biocontrol applications. The aim of this study was to find effective phages capable of lysing this pathogen. Twenty samples were searched for phages against E. coli O157:H7. The host range of the isolated phages was determined. The phages with broader host range were selected for structural study. The stability in different temperature and pH values were also performed. Phages kmuOR and kmuGH could lyse two strain of E. coli O157:H7, some clinical non-O157 E. coli strains, and a strain of Shigella flexneri, another enteric pathogen. Transmission electronic micrograph revealed that both phages belong to Myoviridae family. The two phages were resistant to pH 3 to 9.5 and temperatures 4-50°C and able to prevent the growth of E. coli O157:H7 in LB medium. Further study can prove the suitability of these phages as biocontrol or phage therapy agents.

Nuclease-like metalloscissors: Biomimetic candidates for cancer and bacterial and viral infections therapy

Despite the extensive and rapid discovery of modern drugs for treatment of cancer, microbial infections, and viral illnesses; these diseases are still among major global health concerns. To take inspiration from natural nucleases and also the therapeutic potential of metallopeptide antibiotics such as the bleomycin family, artificial metallonucleases with the ability of promoting DNA/RNA cleavage and eventually affecting cellular biological processes can be introduced as a new class of therapeutic candidates. Metal complexes can be considered as one of the main categories of artificial metalloscissors, which can prompt nucleic acid strand scission. Accordingly, biologists, inorganic chemists, and medicinal inorganic chemists worldwide have been designing, synthesizing and evaluating the biological properties of metal complexes as artificial metalloscissors. In this review, we try to highlight the recent studies conducted on the nuclease-like metalloscissors and their potential therapeutic applications. Under the light of the concurrent Covid-19 pandemic, the human need for new therapeutics was highlighted much more than ever before. The nuclease-like metalloscissors with the potential of RNA cleavage of invading viral pathogens hence deserve prime attention.

In silico and in vitro antileishmanial effects of gamma-terpinene: Multifunctional modes of action

INTRODUCTION

Leishmaniasis denotes a significant health challenge worldwide with no ultimate treatment. The current study investigated the biological effects of gamma-terpinene (GT) on Leishmania major in putative antileishmanial action, cytotoxicity, apoptosis induction, gene expression alteration, antioxidant activity, hemolysis, and ROS generation.

METHODS

GT and meglumine antimoniate (MA) were probed alone and in combination (GT/MA) for their anti-leishmanial potentials using the MTT biochemical colorimetric assay and a model macrophage cell. In addition, their immunomodulatory properties were assessed by analyzing their effect on the transcription of cytokines related to Th1 and Th2 responses. GT and MA, alone and in combination, were also assessed for their potential to alter metacaspase gene expression in L. major promastigotes by real-time RT-PCR. The hemolytic potential of GT and MA-treated promastigotes were also measured by routine UV absorbance reading. Electrophoresis on agarose gel was employed to analyze genomic DNA fragmentation.

RESULTS

GT demonstrated notable dose-dependent antileishmanial effects towards promastigotes and amastigotes of L. major. The IC₅₀ values for GT against L. major promastigotes and amastigotes were 46.76 mM and 25.89 mM, respectively. GT was considerably safer towards murine macrophages than L. major amastigotes with an SI value of 3.17. Transcriptional expression of iNOS, JAK-1, Interleukin (IL-10), and TGF-β was meaningfully decreased, while the levels of metacaspase mRNA were increased. Results also confirmed GT antioxidant activities. Also, increased levels of intracellular ROS were observed upon treatment of promastigotes with GT. The gel electrophoresis result indicated slight DNA fragmentation in the treated promastigotes by both drugs. A weak hemolytic effect was also observed for GT.

CONCLUSION

The results demonstrated that GT showed potent activity against L. major stages. It seems that its mechanism of action involves representing an immunomodulatory role towards upregulation of iNOS and JAK-1, while downregulation of IL-10 and TGF- β. Moreover, GT has an antioxidative potential and exerts its action through activating macrophages to kill the organism. Further in vivo and clinical studies are essential to explore its effect in future programs.

In vitro biological and in silico molecular docking and ADME studies of a substituted triazine-coordinated cadmium(II) ion: efficient cytotoxicity, apoptosis, genotoxicity, and nuclease-like activity plus binding affinity towards apoptosis-related proteins

A cadmium(II) complex containing dppt ligand with the formula [CdCl₂(dppt)₂], where dppt is 5,6-diphenyl-3-(2-pyridyl)-1,2,4-triazine was synthesized, elucidated and submitted to in vitro cytotoxicity studies against human breast (MCF-7), glioblastoma (U-87), and lung (A549) cancer cell lines as well as mouse embryo normal cell line (NIH/3T3), in comparison with cisplatin employing MTT assay over 24 and 48 h. The complex exhibited the highest cytotoxic effect against MCF-7 cells among the other three cell lines with IC₅₀ values of 8.7 ± 0.5 (24 h) and 1.2 ± 0.7 µM (48 h). Significantly, flow cytometric assessment of the complex-treated MCF-7 and U-87 cells demonstrated a dose-dependent induced apoptotic cell death. The cellular morphological changes were in concord with cytotoxicity and flow cytometric results. The results of comet assay showed that the complex is able to induce DNA damage in MCF-7 cells. These observations are of importance, as sustained damage to cellular DNA could lead to apoptotic cell death. The results of DNA-binding studies indicated that the complex fits into the DNA minor groove and interacts with DNA via a partial intercalation. Moreover, the complex was able to efficiently cleave pUC19 DNA through a hydrolytic mechanism. The binding affinity between the complex and apoptosis-relevant protein targets including APAF1, Bax, Bcl-2, Cas3, Cas7, and Cas9 was evaluated through molecular docking studies. In silico virtual studies revealed the complex's strong affinity towards apoptosis-related proteins; therefore the complex can act as a potential apoptosis inducer. Physicochemical, pharmacokinetics, lipophilicity, drug-likeness, and medicinal chemistry properties of the complex were also predicted through in silico absorption, distribution, metabolism and excretion studies.

The System of Awarding Degrees in Higher Education of Iran and United Kingdom: A Descriptive-Comparative Study With Focusing on the Internationalization of Health Education

The main indicators of higher education (HE) internationalization in the field of awarding degrees are the international development of disciplines and interdisciplinary sciences, new educational and learning methods, new and updated curricula, and their correct ways of sharing. This study aimed to examine the system of awarding degrees in health HE of Iran and the United Kingdom. This descriptive-comparative study focused on the field of medical sciences and its related disciplines. The vital information about the variables was collected by visiting the official websites of the UK universities and related or joint organizations. The related information to the Kerman University of Medical Sciences as a sample of Iran medical universities was obtained from the university’s Farabar system. All data extraction steps were performed manually. There were differences in the mechanism of setting up a new discipline and the process of students’ admission, diversity of degrees’ titles and curriculums, stability of disciplines over the time, creativity in creating competition between different disciplines, the reason for establishing a discipline and the requirements for certification and awarding of degrees in health sciences disciplines in Iran and the United Kingdom were described. Propelling of medical education in the health sciences area towards standard awarding degree systems can be responsible for the requirements of internationalization of higher education.

Rapid microwave-assisted biosynthesis of platinum nanoparticles and evaluation of their antioxidant properties and cytotoxic effects against MCF-7 and A549 cell lines

In this study, platinum nanoparticles (Pt NPs) were synthesized by a green method using an aqueous extract of Eucalyptus camaldulensis with assistance of microwave irradiation (850 W) and their physicochemical characteristics were studied by UV-visible spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) analyses. Antioxidant activities, hemocompatibility, and cytotoxic effects of the prepared Pt NPs were then evaluated. The attained results showed that the newly formed Pt NPs possess a size range between 7.4 and 11.2 nm. These spherical-shaped NPs were slightly aggregated and held various functional groups on their surface. The antioxidant activity of Pt nanostructures was comparable to that of butylated hydroxyl anisole at concentrations higher than 320 µg/mL. At the same concentration of 640 μg/mL, the scavenging activities were 3.36 ± 0.9% (hexachloroplatinic acid) and 52.13 ± 0.43% (Pt NPs). The results of hemolytic assay revealed satisfactory hemocompatibility of the Pt NPs even at the concentration as high as 4 mg/mL (hemolysis percent equal to 3.5 ± 1.3%). The cytotoxicity studies revealed that MCF-7, A549, and 3T3 cell lines treated with hexachloroplatinic acid and cisplatin for 24 h and 48 h showed a higher percentage of cell death compared with the Pt NPs. After 24 h, for A549, 3T3, and MCF-7 cells exposed to Pt NPs, the cell viability was measured to be 80 ± 3.2%, 96 ± 1%, and 89 ± 2.6%, respectively, at concentration of 640 µg/mL. Further investigations are required to elucidate the mechanisms behind the biological activities of as-synthesized Pt NPs.

A brief review on DNA vaccines in the era of COVID-19

This article provides a brief overview of DNA vaccines. First, the basic DNA vaccine design strategies are described, then specific issues related to the industrial production of DNA vaccines are discussed, including the production and purification of DNA products such as plasmid DNA, minicircle DNA, minimalistic, immunologically defined gene expression (MIDGE) and Doggybone™. The use of adjuvants to enhance the immunogenicity of DNA vaccines is then discussed. In addition, different delivery routes and several physical and chemical methods to increase the efficacy of DNA delivery into cells are explained. Recent preclinical and clinical trials of DNA vaccines for COVID-19 are then summarized. Lastly, the advantages and obstacles of DNA vaccines are discussed.

Cytotoxicity of mancozeb on Sertoli-germ cell co-culture system: Role of MAPK signaling pathway

Mancozeb (MZB) is a worldwide fungicide for the management of fungal diseases in agriculture and industrial contexts. Human exposure occurs by consuming contaminated plants, drinking water, and occupational exposure. There are reports on MZB's reprotoxicity such as testicular structure damage, sperm abnormalities, and decrease in sperm parameters (number, viability, and motility), but its molecular mechanism on apoptosis in testis remains limited. To investigate the molecular mechanisms involved in male reprotoxicity induced by MZB, we used primary cultures of mouse Sertoli-germ cells. Cells were exposed to MZB (1.5, 2.5, and 3.5 μM) for 3 h to evaluate viability by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay, reactive oxygen species (ROS) generation, and oxidative stress parameters (lipid peroxidation). Cell death and mitogen-activated protein kinase (MAPK) signaling were measured in these cells using flow cytometry and western blotting. In addition, some groups were exposed to N-acetylcysteine (NAC, 5 mM) in the form of co-treatment with MZB. Mancozeb reduced viability and increased the level of intracellular ROS, p38 and c-Jun N-terminal kinases (JNK) MAPK proteins phosphorylation, and apoptotic cell death, which could be blocked by NAC as an inhibitor of oxidative stress. The present study indicated for the first time the toxic manifestations of MZB on the Sertoli-germ cell co-culture. Redox imbalance and p38 and JNK signaling pathway activation might play critical roles in MZB-induced apoptosis in the male reproductive system.

Optimization of immobilization of Pseudomonas cepacia lipase on multiwalled carbon nanotubes functionalized with glycyrrhizin and Tween 80

In the present study, multiwalled carbon nanotubes (MWCNTs) were functionalized with glycyrrhizin and Tween 80 and applied for immobilization of Pseudomonas cepacia lipase (PcL). Characterization of f-MWCNTs was performed through Fourier-transform infrared spectroscopy, thermal gravimetric, field emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy analysis. The optimum specific activity of immobilized PcL (studied by Plackett-Burman statistical design) occurred at 0.3 mg/mL of f-MWCNTs, 25 mM of phosphate buffer (pH 6.0), 15 min sonication time, 8 U/mL of enzyme concentration, and 24 h immobilization time at 4 °C in the absence of glutaraldehyde. In these conditions, the specific activity was 16.57 ± 0.71 U/mg, which was very close to the predicted amount (16.62 ± 0.64 U/mg). The results of thermal and pH stability showed that the stability of immobilized PcL was higher than that of the free PcL. The activity of immobilized PcL on f-MWCNTs held 93% after being incubated for 60 min at 70 °C. Moreover, the immobilized PcL on f-MWCNTs retained about 65% of its initial activity after 30 days of storage at 25 °C. In addition, about 50% of initial activity of immobilized PcL retained after 10 cycles of uses. Therefore, f-MWCNTs could be introduced as suitable support for enzymes immobilization.

In silico and in vitro inhibitory potential of an organometallic Cu (II) complex on Leishmania major stages

Leishmaniosis results in a serious complication, principally in the tropical and subtropical areas. Metalcored complexes, like meglumine antimoniate (MA) have proven antileishmanial activity. Similarly, in this research, we investigated the effects of Cu (II) dimethoxy bipyridine (CuDMOBP) against Leishmania major stages in silico and in vitro. Molecular docking analysis was carried out on the complex and a protozoan metacaspase. The complex's antipromastigote and its cytotoxicity towards macrophages were assayed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method to calculate relative Inhibitory Concentration 50% (IC50), Cytotoxic Concentration 50% (CC50), and Selectivity Index (SI). Expression of TNF-α and IL-10 in intracellular amastigotes and induction of apoptosis was also investigated using quantitative real-time PCR. The complex interacted effectively with four amino acid residues including lysine (Lys171), histidine (His193), arginine (Arg44 and Arg243) of the targeted metacaspase. This indicates a potential affinity between the target macromolecule and the complex. MTT results showed significant in vitro inhibitory effects against promastigotes. Reduction in cellular expression of IL-10 and TNF-α was also significant, p<0.05 and p<0.005, respectively. CuDMOBP showed powerful in vitro anti-leishmanial activity and could be introduced as a new leishmanicidal candidate.

Bioactive anti-oxidative polycaprolactone/gelatin electrospun nanofibers containing selenium nanoparticles/vitamin E for wound dressing applications

In this study, polycaprolactone/gelatin (PCL/GEL) electrospun nanofibers containing biogenic selenium nanoparticles (Se NPs) and Se NPs/vitamin E (VE) with average diameters of 397.8 nm and 279.5 nm, respectively (as determined by SEM inspection) were prepared and their effect on wound healing was evaluated using in-vivo studies. The energy dispersive X-ray (EDX) mapping, TEM micrograph, and FTIR spectra of the prepared nanofibers strongly demonstrated well entrapment of Se NPs and VE into scaffolds. An amount of 57% Se NPs and 43% VE were gradually released from PCL/GEL/Se NPs/VE scaffold after 4 days immersion in PBS solution (pH 7.4). The both PCL/GEL/Se NPs and PCL/GEL/Se NPs/VE scaffolds supported 3T3 cell proliferation and attachment as confirmed by MTT assay and SEM imaging. Complete re-epithelialization, low level of edema and inflammatory cells in coordination with high level of oriented collagens demonstrated the wound healing activity of PCL/GEL/Se NPs/VE. Besides, significant antioxidant efficacy of PCL/GEL/Se NPs and PCL/GEL/Se NPs/VE scaffolds was demonstrated according to GSH and MDA assays. To sum up, the prepared PCL/GEL/Se NPs/VE scaffold in the present study represented suitable healing effect on animal model which candidate it for further studies.

Socialization During the COVID-19 Pandemic: The Role of Social and Scientific Networks During Social Distancing

In the COVID-19 era, while we are encouraged to be physically far away from each other, social and scientific networking is needed more than ever. The dire consequences of social distancing can be diminished by social networking. Social media, a quintessential component of social networking, facilitates the dissemination of reliable information and fighting against misinformation by health authorities. Distance learning, telemedicine, and telehealth are among the most prominent applications of networking during this pandemic. Additionally, the COVID-19 pandemic highlights the importance of collaborative scientific efforts. In this chapter, we summarize the advantages of harnessing both social and scientific networking in minimizing the harms of this pandemic. We also discuss the extra collaborative measures we can take in our fight against COVID-19, particularly in the scientific field.

Design, synthesis, biological evaluation, and molecular dynamics of novel cholinesterase inhibitors as anti-Alzheimer's agents

A series of novel chroman-4-one derivatives were designed and synthesized successfully with good to excellent yield (3a-l). In addition, the obtained products were evaluated for their cholinesterase (ChE) inhibitory activities. The results show that among the various synthesized compounds, analogs bearing the piperidinyl ethoxy side chain with 4-hydroxybenzylidene on the 3-positions of chroman-4-one (3l) showed the most potent activity with respect to acetylcholinesterase (anti-AChE activity; IC₅₀  = 1.18 μM). In addition, the structure-activity relationship was studied and the results revealed that the electron-donating groups on the aryl ring of the 3-benzylidene fragment (3k, 3l) resulted in the designed compounds to be more potent ChE inhibitors in comparison with those having electron-withdrawing groups (3h). In this category, the strongest ChE inhibition was found for the compound containing piperidine as cyclic amine, and a hydroxyl group (for AChE, compound 3l) and fluoro group (for butyrylcholinesterase (BuChE, compound 3i) on the para-position of the aryl ring of the benzylidene group. The molecular docking and dynamics studies of the most potent compounds (3i and 3l against BuChE and AChE, respectively) demonstrated remarkable interactions with the binding pockets of the ChE enzymes and confirmed the results obtained through in vitro experiments.

Tris-chelated complexes of nickel(II) with bipyridine derivatives: DNA binding and cleavage, BSA binding, molecular docking, and cytotoxicity

Two nickel(II) complexes with substituted bipyridine ligand of the type [Ni(NN)₃](ClO₄)₂, where NN is 4,4'-dimethyl-2,2'-bipyridine (dimethylbpy) (1) and 4,4'-dimethoxy-2,2'-bipyridine (dimethoxybpy) (2), have been synthesized, characterized, and their interaction with DNA and bovine serum albumin (BSA) studied by different physical methods. X-ray crystal structure of 1 shows a six-coordinate complex in a distorted octahedral geometry. DNA-binding studies of 1 and 2 reveal that both complexes sit in DNA groove and then interact with neighboring nucleotides differently; 2 undergoes a partial intercalation. This is supported by molecular-docking studies, where hydrophobic interactions are apparent between 1 and DNA as compared to hydrogen bonding, hydrophobic, and π-π interactions between 2 and DNA minor groove. Moreover, the two complexes exhibit oxidative cleavage of supercoiled plasmid DNA in the presence of hydrogen peroxide as an activator in the order of 1 > 2. In terms of interaction with BSA, the results of spectroscopic methods and molecular docking show that 1 binds with BSA only via hydrophobic contacts while 2 interacts through hydrophobic and hydrogen bonding. It has been extensively demonstrated that the nature of the methyl- and methoxy-groups in ligands is a strong determinant of the bioactivity of nickel(II) complexes. This may justify the above differences in biomolecular interactions. In addition, the in vitro cytotoxicity of the complexes on human carcinoma cells lines (MCF-7, HT-29, and U-87) has been examined by MTT assay. According to our observations, 1 and 2 display cytotoxicity activity against selected cell lines. Communicated by Ramaswamy H. Sarma.

Mancozeb induces testicular dysfunction through oxidative stress and apoptosis: Protective role of N-acetylcysteine antioxidant

Mancozeb (MZB) is one of the fungicides used in pest control programs that might affect human health including reproductive system. The aim of this study was to demonstrate the mechanisms through which MZB induces testicular tissue damage and the probable protective effect of N-acetylcysteine (NAC), a modified amino acid, with antioxidant property, against MZB toxicity in an animal model. Male albino mice ( n = 8) were exposed to different doses of MZB (250 and 500 mg/kg/day) by oral gavage without or with NAC (200 mg/kg, twice/week) for 40 days. Sub-chronic MZB dose-dependently decreased sperm motility and count. Exposure to MZB increased lipid peroxidation and protein carbonyl, while it reduced antioxidant enzymes activities, total antioxidant capacity, and glutathione content. The histopathological examination clearly showed deleterious changes in the testicular structure. At the molecular levels, the results of quantitative real time-poly chain reaction (qRT-PCR) showed that MZB upregulated oxidative stress markers inducible nitric oxide synthase (iNOS) and NADPH oxidase 4 (NOX4) and downregulated expression of the glutathione peroxidase 1 (Gpx1) gene as one of the most important antioxidant enzymes. MZB also induced apoptosis dose-dependently in the testes as determined by the terminal dUTP nick-end labeling assay and immunoblotting. NAC administration decreased the mRNA levels of both iNOS and NOX4 with a concomitant increase in Gpx1 expression. It also significantly decreased MZB-induced oxidative stress and apoptosis. Collectively, the present study showed MZB-induced oxidative damage in testes leading to apoptosis. It revealed that antioxidants such as NAC can mitigate oxidant injury induced by the dithiocarbamate pesticides in the reproductive system.

Production and characterization of monoclonal antibodies against aflatoxin B1

In this article, we embarked on production of mouse monoclonal antibodies against aflatoxin B1 which is the most commonly occurring fungal toxin in food and feed products. After immunization and fusion with myloma cells, two stable clones (A218 and B319) were selected. Isotyping showed that these monoclonal antibodies (mAbs) were IgG2b with kappa light chains. The affinity of A218 and B319 clons were 5×10(11) M(-1) and 6×10(9) M(-1), respectively. Competitive indirect ELISA results indicated these mAbs had complete (100%) cross-reaction with four major types of aflatoxins: B1, B2, G1, and G2. These mAbs could be used for immunoassay measurement of aflatoxins with high affinity and low detection limits.

Oxidative stress induced in the workers of natural gas refineries, no role for GSTM1 and GSTT1 polymorphisms

Oxidative stress has an important role in the pathophysiology of many occupational diseases. In this controlled exposure study, the intensity of oxidative stress biomarkers was assessed in the workers of natural sweet and sour gas refineries (SwGR and SoGR, respectively) and compared with controls. In addition, the role of gluthatione S-transferase M1 (GSTM1)-null and GSTT1-null polymorphisms on the intensity of oxidative stress and liver function tests (LFTs) was investigated. Blood samples were taken and measured for lipid peroxidation (LPO) level, total antioxidant capacity (TAC) and total thiol molecules (TTMs). GSTM1- and GSTT1-null genotypes were determined using polymerase chain reaction. LPO was significantly ( p < 0.05) higher in the workers of SoGR. TAC was significantly lower in SwGR subjects ( p < 0.001). TTMs were significantly lower in SoGR and SwGR subjects. Among LFTs, activities of aspartate aminotransferase and alanine aminotransferase but not alkaline phosphatase were elevated significantly ( p < 0.001) in SoGR subjects. Multivariate linear regression revealed no association between studied polymorphisms, oxidative stress biomarkers, and LFTs. These results indicate that working in the SoGR and SwGR can lead to oxidative stress and abnormal LFTs. Continuous monitoring of natural gas workers for probable ongoing problems is therefore suggested.