Induction of somatic cell haploidy by premature cell division.

Canonical mitotic and meiotic cell divisions commence with replicated chromosomes consisting of two sister chromatids. Here, we developed and explored a model of premature cell division, where nonreplicated, G0/G1-stage somatic cell nuclei are transplanted to the metaphase cytoplasm of mouse oocytes. Subsequent cell division generates daughter cells with reduced ploidy. Unexpectedly, genome sequencing analysis revealed proper segregation of homologous chromosomes, resulting in complete haploid genomes. We observed a high occurrence of somatic genome haploidization in nuclei from inbred genetic backgrounds but not in hybrids, emphasizing the importance of sequence homology between homologs. These findings suggest that premature cell division relies on mechanisms similar to meiosis I, where genome haploidization is facilitated by homologous chromosome interactions, recognition, and pairing. Unlike meiosis, no evidence of recombination between somatic cell homologs was detected. Our study offers an alternative in vitro gametogenesis approach by directly reprogramming diploid somatic cells into haploid oocytes.

Enhancing differentiation of menstrual blood-derived stem cells into female germ cells using a bilayer amniotic membrane and nano-fibrous fibroin scaffold.

Three-dimensional nanofiber scaffolds offer a promising method for simulating in vivo conditions within the laboratory. This study aims to investigate the influence of a bilayer amniochorionic membrane/nanofibrous fibroin scaffold on the differentiation of human menstrual blood mesenchymal stromal/stem cells (MenSCs) into female germ cells. MenSCs were isolated and assigned to four culture groups: (i) MenSCs co-cultured with granulosa cells (GCs) using the scaffold (3D-T group), (ii) MenSCs using the scaffold alone (3D-C group), (iii) MenSCs co-cultured only with GCs (2D-T group), and (iv) MenSCs without co-culture or scaffold (2D-C group). Both MenSCs and GCs were independently cultured for two weeks before co-culturing was initiated. Flow cytometry was employed to characterize MenSCs based on positive markers (CD73, CD90, and CD105) and negative markers (CD45 and CD133). Additionally, flow cytometry and immunocytochemistry were used to characterize the GCs. Differentiated MenSCs were analyzed using real-time PCR and immunostaining. The real-time PCR results demonstrated significantly higher levels of VASA expression in the 3D-T group compared to the 3D-C, 2D-T, and 2D-C groups. Similarly, the SCP3 mRNA level in the 3D-T group was notably elevated compared to the 3D-C, 2D-T, and 2D-C groups. Moreover, the expression of GDF9 was significantly higher in the 3D-T group when compared to the 3D-C, 2D-T, and 2D-C groups. Immunostaining results revealed a lack of signal for VASA, SCP3, or GDF9 markers in the 2D-T group, while some cells in the 3D-T group exhibited positive staining for all these proteins. These findings suggest that the combination of a bilayer amniochorionic membrane/nanofibrous fibroin scaffold with co-culturing GCs facilitates the differentiation of MenSCs into female germ cells.

Histone deacetylase 4 and 5 translocation elicited by microsecond pulsed electric field exposure is mediated by kinase activity.

Electroporation-based technologies using microsecond pulsed electric field (µsPEF) exposures are established as laboratory and clinical tools that permeabilize cell membranes. We demonstrate a µsPEF bioeffect on nucleocytoplasmic import and export of enzymes that regulate genetic expression, histone deacetylases (HDAC) -4 and -5. Their µsPEF-induced nucleocytoplasmic transport depends on presence and absence of extracellular calcium ions (Ca2+) for both MCF7 and CHO-K1 cells. Exposure to 1, 10, 30 and 50 consecutive square wave pulses at 1 Hz and of 100 µs duration with 1.45 kV/cm magnitude leads to translocation of endogenous HDAC4 and HDAC5. We posit that by eliciting a rise in intracellular Ca2+ concentration, a signaling pathway involving kinases, such as Ca2+/CaM-dependent protein kinase II (CaMKII), is activated. This cascade causes nuclear export and import of HDAC4 and HDAC5. The potential of µsPEF exposures to control nucleocytoplasmic transport unlocks future opportunities in epigenetic modification.

Evaluation of immune system in patients with transfusion-dependent beta-thalassemia in Rasoul-e-Akram Hospital in 2021: A descriptive cross-sectional study.

Background and aims: Thalassemia syndromes are the most common hemoglobinopathy globally related to blood transfusion and iron overload in the body. Splenectomy, excessive iron overload, and repeated exposure to antigens in blood transfusions can cause severe damage to the patient's immune system making the patient prone to frequent infection. This study evaluates the immune system status and infection rate in beta-thalassemia major patients receiving iron chelators. Methods: This descriptive cross-sectional study was performed in Rasoul-e-Akram Hospital on patients with a beta-thalassemia major who had iron overload due to frequent blood transfusions. The percentage of lymphocyte markers was determined by flow cytometry. Serum levels of immunoglobin were measured by nephelometric assay. Also, Nitro blue tetrazolium and dihydrorhodamine assays were used to evaluate the phagocytic function. Results: Of the 106 patients participating in this study, 59 (55.7%) and 47 (44.3%) are male and female, respectively. The mean age ± SD of participants was 24.7 ± 12.1 years with 4 to 55 years. There was no significant correlation between sex, the C3 and C4 complements, the lymphocyte markers, and the immunoglobulin levels. Furthermore, all of these variables increased significantly over 30 (p < 0.05). Moreover, there was a strong positive correlation between splenectomy and IgG immunoglobulin (p < 0.001) and CD16 (p = 0.005) lymphocyte marker. Conclusion: Iron chelator agents effectively improve patients' immune system with thalassemia major. The increase in IgG and IgM immunoglobulins levels is due to frequent blood transfusions, which stimulate the immune system.

The Clinical Trials of Mesenchymal Stromal Cells Therapy.

Mesenchymal stromal cells (MSCs) are a heterogeneous population of adult stem cells, which are multipotent and possess the ability to differentiate/transdifferentiate into mesodermal and nonmesodermal cell lineages. MSCs display broad immunomodulatory properties since they are capable of secreting growth factors and chemotactic cytokines. Safety, accessibility, and isolation from patients without ethical concern make MSCs valuable sources for cell therapy approaches in autoimmune, inflammatory, and degenerative diseases. Many studies have been conducted on the application of MSCs as a new therapy, but it seems that a low percentage of them is related to clinical trials, especially completed clinical trials. Considering the importance of clinical trials to develop this type of therapy as a new treatment, the current paper is aimed at describing characteristics of MSCs and reviewing relevant clinical studies registered on the NIH database during 2016-2020 to discuss recent advances on MSC-based therapeutic approaches being used in different diseases.

Evaluation of Expression and Phosphorylation of Progesterone Receptor in Endometrial Stromal Cells of Patients with Recurrent Implantation Failure Compared to Healthy Fertile Women.

Recurrent implantation failure (RIF) is the repeated failure of good-quality embryos in implantation process following several assisted reproduction cycles. Disruption of the endometrial receptivity is one of the main causes of RIF. Progesterone plays a pivotal role in the endometrial receptivity through the regulation of gene expression pattern by binding to its receptors in the endometrial cells. The aim of this study was to evaluate the expression level of progesterone receptor (PR) and its phosphorylated form in the endometrial stromal cells (eSC) of RIF patients and compare it to the eSC of healthy fertile women as control group. After isolation of the eSC from biopsy samples of RIF patients and healthy fertile women and their characterization, expression levels of PR mRNA, PR protein, and phospho-Ser294 PR protein were evaluated by quantitative real-time PCR and immunofluorescence staining, respectively. The results demonstrated a significant reduction in PR mRNA expression (P < 0.01.) and phospho-Ser294 PR protein (P < 0.05) level in RIF patients compared to the control group. These data for the first time suggest that the expression of PR and its phosphorylated form are impaired in RIF patients. Therefore, designing therapeutic methods for improving PR expression status and its regulation in the endometrium of RIF patients may help in improving the final reproductive outcomes of these cases.

Green and Fast Synthesis of 2-Arylidene-indan-1,3-diones Using a Task-Specific Ionic Liquid.

A novel method for condensation reaction of indan-1,3-dione with various aldehydes which are efficiently catalyzed by a task-specific ionic liquid, 2-hydroxyethylammonium formate, to provide the corresponding 2-arylidenindane-1,3-diones has been developed. This green, low-cost, high-yield, and fast reaction takes place at room temperature without the use of any solvent and catalyst. A plausible reaction mechanism that involves ionic liquid-assisted activation is also discussed. This work is the first report of ionic liquids as a reaction medium and catalyst for the synthesis of 2-arylidenindane-1,3-diones.

Effect of Vitamin D3 on Mitochondrial Biogenesis in Granulosa Cells Derived from Polycystic Ovary Syndrome.

BACKGROUND: Polycystic ovary syndrome (PCOS) is an endocrine disorder diagnosed by anovulation hyperandrogenism. Hyperandrogenism increases apoptosis, which will eventually disturb follicular growth in PCOS patients. Since mitochondria regulate apoptosis, they might be affected by high incidence of follicular atresia. This may cause infertility. Since vitamin D3 has been shown to improve the PCOS symptoms, the aim of study was to investigate the effects vitamin D3 on mtDNA copy number, mitochondrial biogenesis, and membrane integrity of granulosa cells in a PCOS-induced mouse model. MATERIALS AND METHODS: In this experimental study, the PCOS mouse model was induced by dehydroepiandrosterone (DHEA). Granulosa cells after identification by follicle-stimulating hormone receptor (FSHR) were cultured in three groups: 1. granulosa cells treated with vitamin D3 (100 nM for 24 hours), 2. granulosa cells without any treatments, 3. Non-PCOS granulosa cells (control group). Mitochondrial biogenesis gene (TFAM) expression was compared between different groups using real-time PCR. mtDNA copy number was also investigated by qPCR. The mitochondrial structure was evaluated by transmission electron microscopy (TEM). Hormonal levels were measured by an enzymelinked immunosorbent assay (ELISA) kit. RESULTS: The numbers of pre-antral and antral follicles increased in PCOS group in comparison with the non-PCOS group. Mitochondrial biogenesis genes were downregulated in granulosa cells of PCOS mice when compared to the non-PCOS granulosa cells. However, treatment with vitamin D3 increased mtDNA expression levels of these genes compared to PCOS granulosa cells with no treatments. Most of the mitochondria in the PCOS group were spherical with almost no cristae. Our results showed that in the PCOS group treated with vitamin D3, the mtDNA copy number increased significantly in comparison to PCOS granulosa cells with no treatments. CONCLUSION: According to this study, we can conclude, vitamin D3 improves mitochondrial biogenesis and membrane integrity, mtDNA copy number in granulosa cells of PCOS mice which might improve follicular development and subsequently oocyte quality.

A global systematic review and meta-analysis on illicit drug consumption rate through wastewater-based epidemiology.

Wastewater-based epidemiology (WBE) is a complementary, well-established comprehensive, cost-effective, and rapid technique for monitoring of illicit drugs used in a general population. This systematic review and meta-analysis is the first to estimate the rank and consumption rate of illicit drugs through WBE studies. In the current study, the related investigations regarding the illicit drug consumption rate based on WBE were searched among the international databases including Scopus, PubMed, Science direct, Google scholar, and local database, Magiran from 2012 up to May 2019. The illicit drug consumption rate with 95% confidence intervals was pooled between studies by using random effect model. The heterogeneity was determined using I2 statistics. Also, subgroup analyses were conducted to examine the possible effects of year and location of studies on observed heterogeneity. Meta-analysis of 37 articles indicates that the overall rank order of illicit drugs according to their pooled consumption rate can be summarized as tetrahydrocannabinol or cannabis (7417.9 mg/day/1000 people) > cocaine (655.7 mg/day/1000 people) > morphine (384.9 mg/day/1000 people) > methamphetamine (296.2 mg/day/1000 people) > codeine (222.7 mg/day/1000 people) > methadone (200.2 mg/day/1000 people) > 3,4-methylenedioxymethamphetamine (126.3 mg/day/1000 people) > amphetamine (118.2 mg/day/1000 people) > 2-ethylidene-1,5-dimethyl-3, 3-diphenylpyrrolidine (33.7 mg/day/1000 people). The pooled level rate was 190.16 mg/day/1000 people for benzoylecgonine (main urinary cocaine metabolite), 137.9 mg/day/1000 people for 11-nor-9-carboxy-delta9-tetrahydrocannabinol (main metabolite of cannabis), and 33.7 mg/day/1000 people for 2-ethylidene-1,5-dimethyl-3, 3-diphenylpyrrolidine (main metabolite of methadone). The I2 values for all selected drugs were 100% (P value < 0.001). The results of year subgroup indicated that the changes of heterogeneity for all selected drugs were nearly negligible. The heterogeneity within studies based on continents subgroup just decreased in America for drugs like 11-nor-9-carboxy-delta9-tetrahydrocannabinol (I2 = 24.4%) and benzoylecgonine (I2 = 94.1%). The outcome of this meta-analysis can be used for finding the illicit drugs with global serious problem in view of consumption rate (i.e., cannabis and cocaine) and helping authorities to combat them.

Ab Initio Calculations on Sequential Reactions of Nitric Oxide with Titanium Ions in the Gas Phase.

Potential energy surfaces of sequential reactions of NO with Ti+ ion in the gas phase were investigated for various spin multiplicities using the coupled-cluster and the multireference configuration interaction methods. The mechanisms of Ti+ reactions with up to four NO molecules were fully determined, with all transition-state structures being found by relaxed surface scans and confirmed by the intrinsic reaction coordinate (IRC) calculations. The reaction mechanisms are consistent with the products observed in mass spectrometric experiments. In the first reaction, the nitrogen atom and TiO+ ion are produced with intersystem crossings for singlet and triplet states. The OTi(NO)+ complex is formed in the second reaction, and the third reaction involves N-N bond formation, yielding the N2O molecule and TiO2+ ion. The fourth NO molecule reacts with the TiO2+ ion in an electron-transfer reaction to produce final products TiO2 and NO+. The coupled-cluster relative energies were used as a reference to evaluate the overall performance of common density functionals for this particular reaction.

Vitamin D3 affects mitochondrial biogenesis through mitogen-activated protein kinase in polycystic ovary syndrome mouse model.

Polycystic ovarian syndrome (PCOS) is a disorder characterized by oligomenorrhea, anovulation, and hyperandrogenism. Altered mitochondrial biogenesis can result in hyperandrogenism. The goal of this study was to examine the effect of vitamin D3 on mitochondrial biogenesis of the granulosa cells in the PCOS-induced mouse model. Vitamin D3 applies its effect via the mitogen-activated pathway kinase-extracellular signal-regulated kinases (MAPK-ERK1/2) pathway. The PCOS mouse model was induced by the injection of dehydroepiandrosterone (DHEA). Isolated granulosa cells were subsequently treated with vitamin D3, MAPK activator, and MAPK inhibitor. Gene expression levels were measured using real-time polymerase chain reaction. MAPK proteins were investigated by western blot analysis. We also determined reactive oxygen species (ROS) levels with 2', 7'-dichlorofluorescein diacetate. Mitochondrial membrane potential (mtMP) was also measured by TMJC1. Mitochondrial biogenesis (peroxisome proliferator-activated receptor gamma coactivator 1-α and nuclear respiratory factor), antioxidant (superoxide dismutase, glutathione peroxidase, and catalase), and antiapoptotic (B-cell lymphoma-2) genes were upregulated in the PCOS mice that treated with vitamin D3 compared with the PCOS mice without any treatment. Vitamin D3 and MAPK activator-treated groups also reduced ROS levels compared with the nontreated PCOS group. In summary, vitamin D3 and MAPK activator increased the levels of mitochondrial biogenesis, MAPK pathway, and mtMP markers, while concomitantly decreased ROS levels in granulosa cells of the PCOS-induced mice. This study suggests that vitamin D3 may improve mitochondrial biogenesis through stimulation of the MAPK pathway in cultured granulosa cells of DHEA-induced PCOS mice which yet to be investigated.

DFT study on tautomerism and natural bond orbital analysis of 4-substituted 1,2,4-triazole and its derivatives: solvation and substituent effects.

Density functional theory investigations at the DFT-B3LYP/6-311++G** theoretical level employed to determine the tautomerism, substituent effects of 4-substituted 4-amino-5-methyl-2,4-dihydro-3H-1,2,4-triazole-3-thione, and its derivatives (4-R-H, 4-R-CH3, 4-R-F, 4-R-NO2) in the selected solvent (acetone, acetonitrile, and dichloromethane) and gas phases using the polarizable continuum method (PCM) model. The substituted 1,2,4-triazoles have two main different tautomers namely N2-H and S7-H. For considered derivatives, thione forms are more energetically stable and dominant form in the studied solvent and gas phases. In addition, geometrical parameters, charges on atoms, dipole moments, energetic properties, and the nucleus-independent chemical shifts (NICS) are investigated. It has been seen that these molecular features of the studied compound and its derivatives are mostly solvent dependent. For electron-releasing and -withdrawing derivatives in the solution and gas phases, 2-H forms are the more stable and dominant form. The relative stability of the C4-substituted 1,2,4-triazole tautomerism is influenced by the possibility for intramolecular interactions between substituent and electron-donor or electron-acceptor centers of the triazole ring.

Fabrication of novel 2D Ag-TiO2/γ-Al2O3/Chitosan nano-composite photocatalyst toward enhanced photocatalytic reduction of nitrate.

The presence of excess nitrate in groundwater limits it use as a drinking water supply and its removal is critical to balance the nitrogen cycle in aquatic systems. In this study, ultra-thin 2-dimensional Ag-TiO2/γ-Al2O3/Chitosan (Ag-TiO2/Al2O3/CS) nano-composite was synthesized for the fast reduction of nitrate under UVA irradiation from aqueous solutions. As-synthesized nano-composite was well characterized by X-ray diffraction, transmission electron microscopy, N2 adsorption-desorption isotherms, Fourier-transform infrared spectroscopy and UV-vis diffuse reflectance spectroscopy. Experimental variables including pH, nitrate concentration, photocatalyst dose and contact time were considered to demonstrate their effect on the rate of nitrate reduction. Formic acid was used as a radical scavenger at optimal concentration of 2:1 (formic acid:nitrate). The results showed that upon UVA irradiation, the synthesized nano-composite exhibited fast nitrate reduction in broad pH range (about 74% removal at pH 11 in 5 min reaction time) in diverse water chemical conditions. The Ag-doped and hybrid heterostructures can effectively utilize UV-visible-light to remove nitrate and degrade formic acid. For the 3 cycles the photocatalyst efficiency remained same and after the third cycle, its efficacy decreased gradually. This work suggests 2D Ag-TiO2/Al2O3/CS nano-composite for the fast removal of nitrate in drinking water treatment.

Quantitative response in ion mobility spectrometry with atmospheric pressure chemical ionization in positive polarity as a function of moisture and temperature.

Response of an ion mobility spectrometer at ambient pressure was quantitatively determined for fourteen chemicals from five chemical families spanning a range of proton affinities and temperature from 30 to 175 °C with moisture from 1 to 1 × 104 ppmv in purified air. Peak intensities, drift times and reduced mobility coefficients were determined for hydrated protons from a63Ni ion source and for protonated monomers and proton bound dimers of alcohols, aldehydes, acetates, ketones, and organophosphates. These measurements permitted the determination of response factors with atmospheric pressure chemical ionization and the influence of moisture and temperature on APCI response with correlation to computational models of hydration values. The formation of protonated monomers and proton bound dimers was described by heats of formation for a displacement reaction of water on H+(H2O)n by an analyte vapor and favorably matched results from density functional theory (DFT) with the 6-311 + G(dp) basis set. Response factors worsened with increased moisture and decreased temperature for compounds of medium, and more so, of low proton affinities. Findings here provide a broad measure and understanding for quantitative response in ion mobility spectrometers for substances for combinations of moisture and temperature.

Online breath analysis using metal oxide semiconductor sensors (electronic nose) for diagnosis of lung cancer.

The analysis of exhaled breath is drawing a high degree of interest in the diagnostics of various diseases, including lung cancer. Electronic nose (E-nose) technology is one of the perspective approaches in the field due to its relative simplicity and cost efficiency. The use of an E-nose together with pattern recognition algorithms allow 'breath-prints' to be discriminated. The aim of this study was to develop an efficient online E-nose-based lung cancer diagnostic method via exhaled breath analysis with the use of some statistical classification methods. A developed multisensory system consisting of six metal oxide chemoresistance gas sensors was employed in three temperature regimes. This study involved 118 individuals: 65 in the lung cancer group (cytologically verified) and 53 in the healthy control group. The exhaled breath samples of the volunteers were analysed using the developed E-nose system. The dataset obtained, consisting of the sensor responses, was pre-processed and split into training (70%) and test (30%) subsets. The training data was used to fit the classification models; the test data was used for the estimation of prediction possibility. Logistic regression was found to be an adequate data-processing approach. The performance of the developed method was promising for the screening purposes (sensitivity-95.0%, specificity-100.0%, accuracy-97.2%). This shows the applicability of the gas-sensitive sensor array for the exhaled breath diagnostics. Metal oxide sensors are highly sensitive, low-cost and stable, and their poor sensitivity can be enhanced by integrating them with machine learning algorithms, as can be seen in this study. All experiments were carried out with the permission of the N.N. Petrov Research Institute of Oncology ethics committee no. 15/83 dated March 15, 2017.

Sulfaquinoxaline oxidation by UV-C activated sodium persulfate: Degradation kinetics and toxicological evaluation.

This study evaluates the efficiency of sulfate radicals used in advanced oxidation process in water treatment. The targeted pollutant is an antibiotic, sulfaquinoxaline (SQ-Na) sodium, widely used in the veterinary field. The results show a degradation of SQ-Na until 90% after 300 min of irradiation at optimal sodium persulfate (SPS) concentration (200 mg/L). Degradation of the antibiotic obeys a pseudo-first-order kinetics when the concentration of sulfate radicals ranging from 0 to 240 mg/L. The decomposition of SQ-Na via the UV/SPS method is favored significantly under acidic conditions but becomes slow at neutral pH and almost inhibited under alkaline conditions. The contribution of the sulfate radicals alone and of both radicals hydroxyl and sulfate on the SQ-Na degradation is evaluated at 69% and 80%, respectively. Toxicity tests with Sinapis alba and Daphnia magna on treated samples, before and after irradiation, indicate the formation of new by-products more toxic during the treatment process. PRACTITIONER POINTS: SQ-Na was significantly degraded (90%) under UV/SPS system. SQ-Na decay exhibited a pseudo-first-order kinetics. SQ-Na was completely degraded via UV/SPS process under acidic conditions. The shoot growth appears to be more sensitive to oxidation by-products toxicity than root growth. Ineffectiveness in eliminating the ecotoxicity.

Atmospheric oxidation reactions of imidazole initiated by hydroxyl radicals: kinetics and mechanism of reactions and atmospheric implications.

The atmospheric oxidation mechanism of imidazole initiated by hydroxyl radicals is investigated via OH-addition and H-abstraction pathways by quantum chemistry calculations at the M06-2X/aug-cc-pVTZ level of theory coupled with reaction kinetics calculations using statistical Rice-Ramsperger-Kassel-Marcus (RRKM) theory and transition state theory (TST). It was found that OH addition proceeds more rapidly than H-abstraction by several orders of magnitude. Moreover, H-abstraction reactions with submerged barriers exhibit positive temperature dependence. Effects of reaction temperature and pressure on the reaction between imidazole and OH radicals are studied by means of RRKM calculations. Effective rate coefficients involve two-step mechanisms. According to the experiment, the obtained branching ratios show that the kinetically most efficient process corresponds to OH addition onto a carbon atom which is adjacent to a nitrogen atom having a lower energy barrier. These ratios also reveal that the regioselectivity of the oxidation reaction decreases with increasing temperatures and decreasing pressures. Because of negative activation energies, pressures larger than 100 bar are required to reach the high pressure limit. The atmospheric lifetime of imidazole in the presence of OH radicals is estimated to be ∼4.74 days, based on the calculated overall kinetic rate constant of 1.22 × 10-12 cm3 molecule-1 s-1 at a pressure of 1 bar and nearly ambient temperature. NBO analysis demonstrates that the calculated energy barriers are dictated by charge transfer effects and aromaticity changes because of the delocalization of nitrogen lone pairs to empty π* orbitals.

Ion mobility spectrometers and electron capture detector - A comparison of detection capabilities.

Electron capture detectors (ECDs) and detectors used in ion mobility spectrometry (IMS) have been successfully used for the detection of numerous compounds including hazardous substances. The general principles of their operations are similar and based on sample component ionization and measurement of the signal using the differences in the mobility of electric charge carriers. Differences in sensitivity result from various parameters of these instruments. Value of electric field intensity in ionic reactors have an influence on ionization process. The main goal of the performed tests was to compare the analytical properties of ECD and two types of IMS detectors: a drift tube spectrometer (DT IMS) and a differential mobility spectrometer (DMS). In the work performed, the efficiency of ionization and the response of detectors to selected analytes were compared. ECD, DT IMS and DMS were equipped with 63-Ni radioactive sources. Analytes have been ionized via electron capture process or dissociative electron transfer. Results obtained for oxygen and chloro-substituted organic compounds (carbon tetrachloride, benzyl chloride, chloroform, 2-chloroethyl ethyl sulfide) were used to calculate the relative signal and to compare the ionization efficiency for three detectors. The phenomena observed experimentally were related to energy dependencies and electron capture cross-sections of analytes. The efficiency of ionization in DT IMS was also compared for electron capture when nitrogen was used as the carrier gas, and when the ionization process was based on the collisions of the analyte molecules with the O2- with the use of air.