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1.
This study evaluated the extent of oxidative stress by measuring malondialdehyde and ascorbic acid in the seminal plasma of human subjects with different fertility potential. Semen samples from 148 subjects were evaluated (48 normozoospermics, 34 oligoasthenoteratozoospermics, 34 asthenoteratozoospermics and 32 azoospermics). malondialdehyde level was found to be significantly higher in the abnormal groups (oligoasthenoterato and asthenoterato-zoospermics) than normozoospermics (P < 0.01). Negative correlation was also found between malondialdehyde level, sperm concentration, sperm motility and sperm morphology. Level of ascorbic acid was found to be significantly higher in normozoospermics than other abnormal groups (P < 0.01). It was found to be correlated positively with all seminogram parameters and negatively with malondialdehyde level. The study revealed that, excess lipid peroxidation reflected by high malondialdehyde level with reduced ascorbic acid in human seminal plasma is associated with poor semen quality where as ascorbic acid content has positive correlation with fertility potential.  相似文献   

2.
Quantifying the motility of micro-organisms is beneficial in understanding their biomechanical properties. This paper presents a simple image-based algorithm to derive the kinetic power and propulsive force of the nematode Caenorhabditis elegans. To avoid unnecessary disturbance, each worm was confined in an aqueous droplet of 0.5 μl. The droplet was sandwiched between two glass slides and sealed with mineral oil to prevent evaporation. For motion visualization, 3-μm fluorescent particles were dispersed in the droplet. Since the droplet formed an isolated environment, the fluid drag and energy loss due to wall frictions were associated with the worm''s kinetic power and propulsion. A microparticle image velocimetry system was used to acquire consecutive particle images for fluid analysis. The short-time interval (Δt < 20 ms) between images enabled quasi real-time measurements. A numerical simulation of the flow in a straight channel showed that the relative error of this algorithm was significantly mitigated as the image was divided into small interrogation windows. The time-averaged power and propulsive force of a N2 adult worm over three swimming cycles were estimated to be 5.2 ± 3.1 pW and 1.0 ± 0.8 nN, respectively. In addition, a mutant, KG532 [kin-2(ce179) X], and a wild-type (N2) worm in a viscous medium were investigated. Both cases showed an increase in the kinetic power as compared with the N2 worm in the nematode growth medium due to the hyperactive nature of the kin-2 mutant and the high viscosity medium used. Overall, the technique deals with less sophisticated calculations and is automation possible.  相似文献   

3.
There is growing evidence that damage to spermatozoa by reactive oxygen species play a key role in male infertility. The aim of this study was to assess seminal plasma free 8-Isoprostane levels in men with asthenozoospermia, asthenoteratozoospermia and oligoasthenoteratozoospermia compared to normozoospermic males and its correlation with seminal parameters. The case group consisted of men with asthenozoospermia (n=15), asthenoteratozoospermia (n=16) and oligoasthenoteratozoospermia (n=15). The control group consisted of 16 males with normozoospermia. After Purification of Free 8-Isoprostane by affinity column, its concentration was measured by enzyme immunoassay method. Free 8-Isoprostane evaluation showed significantly greater values in the total case group (n=46) versus control group (18.23±3.56 vs 2.6±0.38 ng/ml). In each case group free 8-Isoprostane also showed a significant increasing compared to normozoospermic males. Free 8-Isoprostane showed an inversely significant correlation with sperm motility and sperm morphology. Lipid peroxidation could have significant role in etiology of sperm abnormalities. Measurement of 8-Isoprostane can be used as a specific biomarker for assessing lipid peoxidation in sperm.  相似文献   

4.
BackgroundResidual oils were characterized according to their physicochemical properties, i.e. acidity, iodine value, peroxide value and saponification number, to evaluate the degradation level and viability for biodiesel production.ResultsThe methyl esters of fatty acids (FAME) from samples of residual bovine, chicken and soybean oils were quantified by using four transesterification methods, using acidic and basic catalysis and, gas chromatography with flame ionization detector (GC–FID). Methods that used acidic catalysis at a lower temperature were the most efficient. Methyl biodiesel samples were synthesized by basic catalysis (KOH) for all quantified oils and the physicochemical properties of the biofuel were evaluated, i.e. viscosity, flash and fire points, density, water content, iodine and acidity numbers.ConclusionsThe obtained results suggesting that it is possible to take advantage of these residues for biodiesel production as the obtained products were approved according to the rules established by the National Association of Petroleum (ANP); the bovine samples were the exception regarding moisture and acidity.  相似文献   

5.
We introduce a method for improved dielectrophoretic (DEP) discrimination and separation of viable and nonviable yeast cells. Due to the higher cell wall permeability of nonviable yeast cells compared with their viable counterpart, the cross-linking agent glutaraldehyde (GLT) is shown to selectively cross-link nonviable cells to a much greater extent than viable yeast. The DEP crossover frequency (cof) of both viable and nonviable yeast cells was measured over a large range of buffer conductivities (22 μS∕cm–400 μS∕cm) in order to study this effect. The results indicate that due to selective nonviable cell cross-linking, GLT modifies the DEP cof of nonviable cells, while viable cell cof remains relatively unaffected. To investigate this in more detail, a dual-shelled oblate spheroid model was evoked and fitted to the cof data to study cell electrical properties. GLT treatment is shown to minimize ion leakage out of the nonviable yeast cells by minimizing changes in cytoplasm conductivity over a large range of ionic concentrations. This effect is only observable in nonviable cells where GLT treatment serves to stabilize the cell cytoplasm conductivity over a large range of buffer conductivity and allow for much greater differences between viable and nonviable cell cofs. As such, by taking advantage of differences in cell wall permeability GLT magnifies the effect DEP has on the field induced separation of viable and nonviable yeasts.  相似文献   

6.
To investigate the effects of antiphospholipid antibodies on establishment of pregnancy and changes in hormones such as estradiol-17ß (E2) and progesterone (P) levels in circulation. Hence, mice were immunized with human β2-Glycoprotein I (β2GPI) and the effect of these antibodies on fetuses weight, placental obsrvation, Serum levels of P and E2 in pregnant mice, hematological were observed. Immunization of mice with human β2-GPI resulted in elevated levels of antiphospholipid antibodies. The experimentally induced antiphospholipid syndrome mouse showed higher rate of fetal resorption, low number of viable fetuses, and “placental abnormalities”. In these animals, serum E2 and P levels were reduced significantly. In addition, the blood cell variation among APS induced and control mice were determined. No significant variations were observed in number of Red Blood Cell count, White Blood Cell count and Hemoglobin content, while platelet number was significantly reduced as compared to control. These results clearly demonstrate that human β2-GPI might be involved in causing gestational failure in APS by exerting their effect on serum hormones.  相似文献   

7.
Defective sperm function is the most common cause of infertility. A prospective study was carried out to correlate the concentration of nitrite (the stable metabolite of nitric oxide) in seminal plasma with leukocytospermia, and sperm membrane integrity. Total Fifty-seven normozoospermic subjects with and without leukocytospermia visiting the Infertility clinic at KH and MRC, Karad, were included in the present study. Semen samples were checked for sperm concentration, total sperm count, sperm motility, seminal leukocyte concentration and sperm membrane integrity as Hypoosmotic Swelling Test. Similarly the concentration of nitrite in seminal plasma was measured by Griess reaction and total antioxidant power measured as ferric reducing ability of plasma. The concentration of nitrite in seminal plasma was found to be raised with significantly increased leukocyte concentration in semen. Also significantly lowered levels of total antioxidant power along with defective sperm function was observed. Our results suggest that supplementary treatment of antioxidants with antibiotic for leukocytospermic infertile male patients may improve the sperm membrane integrity.  相似文献   

8.
Squire's study of thermal stability of a solid infinite cylinder with temperature-sensitive internal heat generation is extended to a hollow infinite cylinder, subject to combinations of four commonly encountered boundary conditions. The results of these analyses indicate that the critical parameter for thermal viability is critically dependent on the cylinder size, the convective heat transfer coefficient and other constants accrued from the cylinder environment. In certain situations, such as a frigid climate, a hollow Squire cylinder is thermally viable only if it is thicker than a critical thickness.  相似文献   

9.
Thermotaxis has been demonstrated to be an important criterion for sperm evaluation, yet clinical assessment of thermotaxis capacity is currently lacking. In this article, the on-chip thermotaxis evaluation of human sperm is presented for the first time using an interfacial valve-facilitated microfluidic device. The temperature gradient was established and accurately controlled by an external temperature gradient control system. The temperature gradient responsive sperm population was enriched into one of the branch channels with higher temperature setting and the non-responsive ones were evenly distributed into the two branch channels. We employed air-liquid interfacial valves to ensure stable isolation of the two branches, facilitating convenient manipulation of the entrapped sperm. With this device, thermotactic responses were observed in 5.7%-10.6% of the motile sperm moving through four temperature ranges (34.0-35.3 °C, 35.0-36.3 °C, 36.0-37.3 °C, and 37.0-38.3 °C, respectively). In conclusion, we have developed a new method for high throughput clinical evaluation of sperm thermotaxis and this method may allow other researchers to derive better IVF procedure.  相似文献   

10.
The present work aims to study the effects of the blood-microstructure on the electrical conduction from two different but correlated properties: Electrical and mechanical (viscosity), and to derive useful parameters for the evaluation of electrical conduction as a function of the blood viscosity. ac-conductivity and dielectric constant of normal and diabetic blood are measured in the frequency range 10 kHz–1 MHz at the room temperature. An empirical relation relating the resistivity and viscosity of the blood has been presented. The results show that a microfluidic device is a viable and simple solution for determination of electrical and rheological behaviors of blood samples.  相似文献   

11.
Micro-orifice based cell fusion assures high-yield fusion without compromising the cell viability. This paper examines feasibility of a dielectrophoresis (DEP) assisted cell trapping method for parallel fusion with a micro-orifice array. The goal is to create viable fusants for studying postfusion cell behavior. We fabricated a microfluidic chip that contained a chamber and partition. The partition divided the chamber into two compartments and it had a number of embedded micro-orifices. The voltage applied to the electrodes located at each compartment generated an electric field distribution concentrating in micro-orifices. Cells introduced into each compartment moved toward the micro-orifice array by manipulation of hydrostatic pressure. DEP assisted trapping was used to keep the cells in micro-orifice and to establish cell to cell contact through orifice. By applying a pulse, cell fusion was initiated to form a neck between cells. The neck passing through the orifice resulted in immobilization of the fused cell pair at micro-orifice. After washing away the unfused cells, the chip was loaded to a microscope with stage top incubator for time lapse imaging of the selected fusants. The viable fusants were successfully generated by fusion of mouse fibroblast cells (L929). Time lapse observation of the fusants showed that fused cell pairs escaping from micro-orifice became one tetraploid cell. The generated tetraploid cells divided into three daughter cells. The fusants generated with a smaller micro-orifice (diameter∼2 μm) were kept immobilized at micro-orifice until cell division phase. After observation of two synchronized cell divisions, the fusant divided into four daughter cells. We conclude that the presented method of cell pairing and fusion is suitable for high-yield generation of viable fusants and furthermore, subsequent study of postfusion phenomena.  相似文献   

12.
The stresses that can be imposed upon higher plant tissues by freezing may be damaging and potentially lethal. They influence the distribution and reproductive behaviour of plant species and are the cause of significant agricultural and horticultural crop losses. In contrast, however, low and ultralow temperatures can be used to conserve viable plant material for subsequent propagation, exploiting either natural resistance to freezing within the tissues or laboratory manipulation to sustain viability.  相似文献   

13.
The characterization of cell viability is a challenging task in applied biotechnology, as no clear definition of cell death exists. Cell death is accompanied with a change in the electrical properties of the membrane as well as the cell interior. Therefore, changes in the physiology of cells can be characterized by monitoring of their dielectric properties. We correlated the dielectric properties of industrially used mammalian cells, sedimented over interdigitated microelectrodes, to the AC signal response across the chip. The voltage waveforms across the electrodes were processed to obtain the circuit impedance, which was used to quantify the changes in cell viability. We observed an initial decrease in impedance, after which it remained nearly constant. The results were compared with data from the dye exclusion viability test, the cell specific oxygen uptake rate, and the online viable cell density data from capacitance probes. The microelectrode technique was found to be sensitive to physiological changes taking place inside the cells before their membrane integrity is compromised. Such accurate determination of the metabolic status during this initial period, which turned out to be less well captured in the dye exclusion tests, may be essential for several biotechnology operations.  相似文献   

14.
Bio-electrospraying (BES) is a technique used for the processing of cells and can be applied to tissue engineering. The association of BES with scaffold production techniques has been shown to be an interesting strategy for the production of biomaterials with cells homogeneously distributed in the entire structure. Various studies have evaluated the effects of BES on different cell types. However, until the present moment, no studies have evaluated the impact of BES time on mesenchymal stem cells (MSC). Therefore, the aim of this work was to standardise the different parameters of BES (voltage, flow rate, and distance of the needle from the collecting plate) in relation to cell viability and then to evaluate the impact of BES time in relation to viability, proliferation, DNA damage, maintenance of plasticity and the immunophenotypic profile of MSC. Using 15 kV voltage, 0.46 ml/h flow rate and 4 cm distance, it was possible to form a stable and continuous jet of BES without causing a significant reduction in cell viability. Time periods between 15 and 60 min of BES did not cause alterations of viability, proliferation, plasticity, and immunophenotypic profile of the MSC. Time periods above 30 min of BES resulted in DNA damage; however, the DNA was able to repair itself within five hours. These results indicate that bio-electrospraying is an adequate technique for processing MSC which can be safely applied to tissue engineering and regenerative medicine.  相似文献   

15.
Electrodeless dielectrophoresis is the best choice to achieve preconcentration of nanoparticles and biomolecules due to its simple, robust, and easy implementation. We designed a simple chip with microchannels and nano-slits in between and then studied the trapping of DNA in high conductive medium and low conductive medium, corresponding to positive and negative dielectrophoresis (DEP), respectively. It is very important to investigate the trapping in media with different conductivities since one always has to deal with the sample solutions with different conductivities. The trapping process was analyzed by the fluorescent intensity changes. The results showed that DNA could be trapped at the nano-slit in both high and low conductive media in a lower electric field strength (10 V/cm) compared to the existing methods. This is a significant improvement to suppress the Joule heating effect in DEP related experiments. Our work may give insight to researchers for DNA trapping by a simple and low cost device in the Lab-on-a-Chip system.  相似文献   

16.
We investigated the effect of UV-B irradiation on PI 3-kinase activity in human fetal hepatocytes. When cells were exposed to monochromatic (304nm) UV-B light, a significant increase in intracellular PI 3-kinase activity was observed in a dose dependent manner with maximal activity upon 1500 Jm−2 irradiation. At 1500 Jm−2 dose PI 3-kinse activity increased by 80% in membrane fraction of fetal hepatocytes of 25 weeks gestation. PI 3-kinse inhibitors wortmannin and LY294002 specifically inhibited the UV-B induced lipid kinase activity and blocked significantly the UV-B induced cell viability. The data suggests a correlation between cell survival and elevated levels of PI 3-kinase and suggest that UV-B irradiation at a dose of 1500 Jm−2 is ideal for fetal hepatocyte transplantation. Also, PI 3-kinase levels could be a representative marker for viable UV-B irradiated fetal hepatocytes for transplantation.  相似文献   

17.
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18.
BackgroundThe extracellular expression of enzymes in a secretion host such as Bacillus subtilis is a useful strategy in reducing the cost of downstream processing of industrial enzymes. Here, we present the first report of the successful extracellular expression in Bacillus subtilis WB800 of Geobacillus stearothermophilus lipase (T1.2RQ), a novel industriallydesirable thermostable lipolytic enzyme which has an excellent hydrolytic and transesterification activity. Signal peptides of α-amylase, extracellular protease, and lipase A, as well as two different promoters, were used in the secretion and expression of lipase T1.2RQ.ResultsLipase activity assay using p-nitrophenyl laurate showed that all three signal peptides directed the secretion of lipase T1.2RQ into the extracellular medium. The signal peptide of lipase A, resulted in the highest extracellular yield of 5.6 U/ml, which corresponds to a 6-fold increase over the parent Bacillus subtilis WB800 strain. SDS-PAGE and zymogram analysis confirmed that lipase T1.2RQ was correctly processed and secreted in its original size of 44 kDa. A comparison of the expression levels of lipase T1.2RQ in rich medium and minimal media showed that the enzyme was better expressed in rich media, with up to an 8-fold higher yield over minimal media. An attempt to further increase the lipase expression level by promoter optimization showed that, contrary to expectation, the optimized promoter exhibited similar expression levels as the original one, suggesting the need for the optimization of downstream factors.ConclusionsThe successful extracellular secretion of lipase T1.2RQ in Bacillus subtilis represents a remarkable feat in the industrial-scale production of this enzyme.How to cite: Ridwan E, Suwanto A, Thenawidjaja M. Extracellular expression in Bacillus subtilis of a thermostable Geobacillus stearothermophilus lipase. Electron J Biotechnol 2021;53. https://doi.org/10.1016/j.ejbt.2021.07.003  相似文献   

19.
The essay compares German and Irish media coverage of human genome research in the year 2000, using qualitative and quantitative frame analysis of a print media corpus. Drawing from a media-theoretical account of science communication, the study examines four analytic dimensions: (1) the influence of global and national sources of discourse; (2) the nature of elaboration on important themes; (3) the extent of societal participation in discourse production; (4) the cultural conditions in which the discourse resonates. The analysis shows that a global discursive package, emphasizing claims of scientific achievement and medical progress, dominates media coverage in both countries. However, German coverage is more extensive and elaborate, and includes a wider range of participants. Irish coverage more often incorporates the global package without further elaboration. These finding indicate that the global package is 'localized' differently due to national patterns of interests, German participation in human genome research, traditions of media coverage, and the domestic resonance of the issue.  相似文献   

20.
IntroductionThe aim of the present study was to determine and compare the concentration of hyaluronic acid (HA) in rheumatoid arthritis (RA), systemic sclerosis (SSc) and systemic lupus erythematosus (SLE), and its correlation with parameters of disease activity and duration. The hypothesis was that HA should be increased in rheumatic diseases. We also expected that HA could be a marker of disease activity and inflammation in some of these diseases.Materials and methodsThe study group comprised 149 patients with RA, SSc and SLE hospitalized in the Department of Rheumatology and Internal Diseases, Medical University of Bialystok (Bialystok, Poland) and 30 healthy controls. The concentrations of HA, C-reactive protein (CRP) and rheumatoid factor (RF) were measured using Architect ci8200; haemoglobin, platelets on Sysmex XS-800i; and erythrocyte sedimentation rate (ESR) on Sediplus S 2000 analysers. Statistical analysis was performed using Statistica 13.3 PL.ResultsHyaluronic acid was increased in RA, SLE and SSc when compared to controls (P < 0.001, P = 0.011, and P = 0.015, respectively). There were no differences in HA between rheumatic diseases (P = 0.840). Hyaluronic acid positively correlated with SLE activity (P = 0.025). In RA, HA positively correlated with ESR (P = 0.028) and CRP (P = 0.009). However, HA was not found to correlate with the duration of rheumatic diseases.ConclusionsHyaluronic acid concentration undergoes changes in rheumatic diseases with no difference between RA, SLE and SSc. In RA, HA concentration can be a marker of inflammation, while in SLE patients an indicator of disease activity.  相似文献   

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