Amount Of Cell Lysis Research Articles

Investigating the Role of EPA and DHA on Cellular Oxidative Stress; Profiling Antidiabetic and Antihypertensive Potential.

Polyunsaturated fatty acids (PUFAs) remain part of the diet and are essential for growth and development. Furthermore, omega - 3 fatty acids boost various cardiovascular disease risk factors as well as lower blood pressure and cholesterol levels. The effects of PUFAs on glycemia in type 2 diabetes patients are unclear. In the present study, the anti-diabetic and anti-hypertensive potential of eicosapentenoic acid (EPA) and docosahexaenoic acid (DHA)-two polyunsaturated fatty acids-were examined. Using 3T3-L1 pre-adipocyte cells fed with PUFAs, the antioxidant capacity of EPA and DHA was assessed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay/test. The DPPH activity of EPA and DHA was 49.72 and 50.51%, respectively, indicating a reduction in oxidative stress. The number, size, and total lipid content of adipocytes in adipose tissue were used to study the anti-diabetic effect of EPA and DHA. Both PUFAs were revealed to have a much lower capacity for cell lysis of 3T3-L1 pre-adipocytes when compared to propylene glycol monomethyl ether acetate (PMA). In 3T3-L1 pre-adipocyte cells that had been treated with EPA and DHA, the gene expression profiles for ATP synthase 6 were examined. The results demonstrated a similar trend of reducing total lipid content in 3T3-L1 pre-adipocyte cells treated with EPA and DHA. The amount of cell lysis was then examined for 3T3-L1 pre-adipocyte cells exposed to DHA and EPA, and the results showed 38.45% and 41.26%, respectively. In the 3T3-L1 pre-adipocyte cells, treatment with PUFAs, EPA, and DHA dramatically lowered total lipid content after 48 hours. The study also revealed that exposing 3T3-L1 pre-adipocyte cells to EPA at 90 g/ml for 48 hours reduced the total lipid content by a significant amount. According to the findings, EPA and DHA therapy reversed oxidative stress in mitochondria and upregulated the ATP synthase 6 gene. This discovery shows how EPA and DHA have anti-diabetic and hypertension properties.

Role of Temperate Bacteriophage ϕ20617 on Streptococcus thermophilus DSM 20617T Autolysis and Biology.

Streptococcus thermophilus DSM 20167T showed autolytic behavior when cultured in lactose- and sucrose-limited conditions. The amount of cell lysis induced was inversely related to the energetic status of the cells, as demonstrated by exposing cells to membrane-uncoupling and glycolysis inhibitors. Genome sequence analysis of strain DSM 20617T revealed the presence of a pac-type temperate bacteriophage, designated Φ20617, whose genomic organization and structure resemble those of temperate streptococcal bacteriophages. The prophage integrated at the 3′-end of the gene encoding the glycolytic enzyme enolase (eno), between eno and the lipoteichoic acid synthase-encoding gene ltaS, affecting their transcription. Comparative experiments conducted on the wild-type strain and a phage-cured derivative strain revealed that the cell-wall integrity of the lysogenic strain was compromised even in the absence of detectable cell lysis. More importantly, adhesion to solid surfaces and heat resistance were significantly higher in the lysogenic strain than in the phage-cured derivative. The characterization of the phenotype of a lysogenic S. thermophilus and its phage-cured derivative is relevant to understanding the ecological constraints that drive the stable association between a temperate phage and its bacterial host.

Citotoxicidade de soldas elétricas a ponto: estudo in vitro

OBJETIVO: o processo de solda envolve íons metálicos capazes de provocar lise celular. Diante disso, o objetivo deste estudo foi testar a hipótese de que existe citotoxicidade entre diferentes tipos de ligas (CrNi, TMA, NiTi) utilizadas em Ortodontia, submetidas à solda elétrica a ponto. MÉTODOS: três tipos de ligas foram avaliados neste estudo. Foram confeccionados 36 corpos de prova, 6 para cada combinação entre os fios, divididos em 6 grupos - grupo AA (aço com aço), grupo AT (aço com TMA), grupo AN (aço com NiTi), grupo TT (TMA com TMA), grupo TN (TMA com NiTi) e grupo NN (NiTi com NiTi) - que foram submetidos à solda a ponto para avaliação quanto ao possível efeito citotóxico nos tecidos bucais. Previamente, os corpos de prova foram limpos com álcool isopropílico e esterilizados em luz ultravioleta. O ensaio de citotoxicidade foi realizado utilizando-se cultura de células (linhagem L929, fibroblastos de camundongos), submetida ao teste para células viáveis em vermelho neutro ("dye-uptake") no tempo de 24h. A análise de variância e comparação múltipla (ANOVA) e teste de Tukey foram utilizados (p< 0,05). RESULTADOS: os resultados demonstraram que não houve diferença estatisticamente significativa entre os grupos experimentais (P> 0,05). Foi observada maior viabilidade celular no grupo TT, seguido dos grupos AT, TN, AA, NA e NN. CONCLUSÃO: pôde-se evidenciar que solda em fios de liga de NiTi causaram maior quantidade de lise celular. Soldas elétricas a ponto demonstraram pequena capacidade de causar lise celular.

Photodisruptive laser nucleation of ultrasonic cavitation for biomedical applications.

Pulses of high intensity laser light, when focused into transparent materials, may produce localized electron-ion plasmas through optical breakdown. By simultaneously incorporating the resulting volume of vaporized material within the focal volume of a high intensity ultrasound source, the photodisruption (1.05 microm wavelength) void served as a nucleation site for ultrasonic cavitation. Dilute suspensions of canine erythrocytes in phosphate buffered saline were exposed in a flow-through exposure chamber and the percentage of lysed cells was used as a measure of the biologically effective cavitation activity produced in the chamber. Brief (about 30 micros) acoustic emissions were detected from the photodisruption alone (indicating laser nucleation of bubbles), but the cell lysis produced was undetectable against the background. However, combined exposure greatly increased both the duration of the acoustic emissions (up to 1.5 ms) and the amount of cell lysis above an ultrasonic pressure amplitude threshold of about 4.3 MPa at 2.5 MHz. The amount of cell lysis (sometimes approaching 100%) increased with increasing ultrasonic intensity, laser pulse energy and laser PRF. Addition of 5% serum albumin enhanced the effect, apparently by stabilizing bubbles and nuclei. Photodisruptive laser nucleation of ultrasonic cavitation can provide controlled and synergistic enhancement of bioeffects.

Comparison of extraction methods for quantifying extracellular polymers in biofilms

Five commonly used extraction methods - regular centrifugation, EDTA extraction, ultracentrifugation, steaming extraction and regular centrifugation with formaldehyde (RCF) - were selected to study their effectiveness and repeatability in extracting extracellular polymeric substances (EPS) from aerobic/sulfate reducing and nitrifying/denitrifying biofilm samples. Biofilm EPS extraction yields were represented by carbohydrate and protein concentrations; the amount of cell lysis during the extractions was indicated by DNA concentration. The results showed that analyzing wash waters is essential in quantifying biofilm EPS; the contribution of this step varied from 8-50% of the total carbohydrate yield, depending on the extraction method. Among the extraction methods, the RCF extraction gave the greatest carbohydrate yield, the steaming extraction gave the greatest protein yield, and the other three extraction methods gave approximately equivalent amounts of carbohydrate and proteins for both types of biofilm. DNA in the EPS was 27 times smaller than in the pellets, indicating no significant cell lysis occurred during the extractions.

Comparison of extraction methods for quantifying extracellular polymers in biofilms

Five commonly used extraction methods — regular centrifugation, EDTA extraction, ultracentrifugatron, steaming extraction and regular centrifugation with formaldehyde (RCF) — were selected to study their effectiveness and repeatability in extracting extracellular polymeric substances (EPS) from aerobic/sulfate reducing and nitrifying/denitrifying biofilm samples. Biofilm EPS extraction yields were represented by carbohydrate and protein concentrations; the amount of cell lysis during the extractions was indicated by DNA concentration. The results showed that analyzing wash waters is essential in quantifying biofilm EPS; the contribution of this step varied from 8–50% of the total carbohydrate yield, depending on the extraction method. Among the extraction methods, the RCF extraction gave the greatest carbohydrate yield, the steaming extraction gave the greatest protein yield, and the other three extraction methods gave approximately equivalent amounts of carbohydrate and proteins for both types of biofilm. DNA in the EPS was 27 times smaller than in the pellets, indicating no significant cell lysis occurred during the extractions

The Effects of the Microbubble Suspension SH U 454 (Echovist®) on Ultrasound‐Induced Cell Lysis In a Rotating Tube Exposure System

Human erythrocytes resuspended at different hematocrits in autologous plasma at 37 degrees C were exposed to the therapeutic intensities of continuous-wave 0.75-MHz ultrasound in vitro in a rotating tube exposure apparatus designed to maximize the destructive effects of cavitational activity. Provided that large numbers of additional gas bubbles had not been introduced during the various preparative and manipulatory procedures, the addition of Echovist at final concentrations comparable with those currently being used for clinical investigations resulted in a statistically significant increase in the amount of cell lysis in vitro in those samples having hematocrits less than 2%. The amount of cell lysis produced at any given ultrasound intensity decreased with increasing hematocrit in both the controls and the cell suspensions containing Echovist until it was virtually zero in both cases at hematocrits of 5.5% or greater. The addition of Echovist to samples that already contained large numbers of stabilized gas bubbles and/or had hematocrits greater than 5.5% produced no detectable cell lysis even at ultrasonic intensities as high as 3 W/cm 2 spatial average, temporal average (SATA). It is therefore unlikely that Echovist would cause appreciable amounts of cell lysis when the gas bubbles were being exposed to ultrasound under the conditions used for clinical investigations in vivo.

Use of hybridoma-resident variant cell lines to study H-2Db/FMR-specific cytotoxic T cells.

An H-2Db heterozygous tumor cell line and a variant subclone bearing a mutant gene product were used to analyze the H-2Db specificity of cytotoxic T lymphocytes (CTL) generated during a Moloney murine sarcoma virus (MSV) infection. When the mutant cells were used as targets for MSV-specific CTL, the amount of cell lysis, compared with that seen with the nonmutant parental cells, was drastically decreased. However, cells of the mutant clones remained susceptible to allogeneic CTL specific for the nonmutant H-2Db molecule. The mutant cells also did not differ from the parent cells in their level of viral antigen expression. Biochemically the parental and mutant molecules were similar but not identical. The data indicate that minor alterations of the H-2 antigens caused by somatic mutation may prevent virus-infected cells from being recognized as targets by CTL.

Description and analysis of a simple micro-titration immune cytolytic test.

A method of micro-titration for cytolytic antibodies is described. Standard drops of diluent are placed on a subdivided siliconed slide and dilutions are made by rotating a wire loop holding 1 drop of serum in each drop sequentially. One drop of a mixture of cells and complement is then added. The slide is incubated in a moist chamber for 90 min at 37° C. after which a small cover-slip is placed on each drop and the amount of cell lysis, judged by phase-contrast microscopy, is graded.An analysis of variance of the method has been performed and the method has been found to be reliable, accurate and unbiased.It allows accurate estimates of cytolytic activity in sera using cell concentrations of 104to 105cells per ml. Eight ten-dilution titrations can be carried out with 1 ml. of such a suspension.