Search results for "fragmentation"
showing 10 items of 798 documents
Quantitative Spatial Analysis of the Mouse Brain Lipidome by Pressurized Liquid Extraction Surface Analysis
2014
Here we describe a novel surface sampling technique termed pressurized liquid extraction surface analysis (PLESA), which in combination with a dedicated high-resolution shotgun lipidomics routine enables both quantification and in-depth structural characterization of molecular lipid species extracted directly from tissue sections. PLESA uses a sealed and pressurized sampling probe that enables the use of chloroform-containing extraction solvents for efficient in situ lipid microextraction with a spatial resolution of 400 μm. Quantification of lipid species is achieved by the inclusion of internal lipid standards in the extraction solvent. The analysis of lipid microextracts by nanoelectrosp…
The effect of cancer on sperm DNA fragmentation as measured by the sperm chromatin dispersion test
2008
The percentage of spermatozoa with fragmented DNA from cancer patients before surgery, chemotherapy, or radiotherapy treatments was compared with infertile male patients in an assisted reproduction program and with sperm donors of proven fertility. The percentages of DNA fragmentation were 34.3% in cancer patients, 30.9% in infertile men whose partners did not become pregnant, 28.8% in men who partners became pregnant, and 10.8% in fertile sperm donors. The DNA fragmentation of sperm donors was statistically significantly lower compared the other groups. No statistically significant differences were found in the levels of DNA fragmentation when comparing cancer types, including those of tes…
Preparation of degraded human DNA under controlled conditions
2003
Abstract DNA typing through analysis of short tandem repeats (STRs) and mitochondrial DNA (mtDNA) by means of the polymerase chain reaction (PCR) and sequencing are the common methods for the forensic identification of persons and reconstruction of kinship, especially when skeletal human remains have to be analyzed. Furthermore, samples typically found at crime scenes may be both quantitatively and qualitatively inadequate since they may contain very scarce and often degraded DNA due to exposure to heat, light, humidity, and microorganisms. In order to improve the performance of STR typing technology in those cases where DNA availability is limited, it would be desirable to have a source of…
Does haplodiploidy purge inbreeding depression in rotifer populations?
2009
Background Inbreeding depression is an important evolutionary factor, particularly when new habitats are colonized by few individuals. Then, inbreeding depression by drift could favour the establishment of later immigrants because their hybrid offspring would enjoy higher fitness. Rotifers are the only major zooplanktonic group where information on inbreeding depression is still critically scarce, despite the fact that in cyclical parthenogenetic rotifers males are haploid and could purge deleterious recessive alleles, thereby decreasing inbreeding depression. Methodology/Principal Findings We studied the effects of inbreeding in two populations of the cyclical parthenogenetic rotifer Brach…
Cell death and oxidative stress in gliomas.
1999
In gliomas, apoptosis and necrosis are determined by a number of promoting and inhibiting factors including oxidative cell stress mediated by nitric oxide synthases (NOS) and reduced by superoxide dismutases. Therefore, in 46 gliomas (including astrocytomas, oligodendrogliomas, oligo-astrocytomas, and glioblastomas), the relationship of apoptosis and necrosis and the expression of apoptosis-promoting (p53, bax, Fas, Fas-L) and inhibiting (bcl-2) factors as well as of different isoforms of NOS (NOSb, NOSe, NOSi) and manganese superoxide dismutase (MnSOD) were studied. Apoptosis was measured in situ by the TUNEL method while expression profiles of apoptosis-related and oxidative stress-associ…
Seed-dispersal distributions by trumpeter hornbills in fragmented landscapes.
2010
Frugivorous birds provide important ecosystem services by transporting seeds of fleshy fruited plants. It has been assumed that seed-dispersal kernels generated by these animals are generally leptokurtic, resulting in little dispersal among habitat fragments. However, little is known about the seed-dispersal distribution generated by large frugivorous birds in fragmented landscapes. We investigated movement and seed-dispersal patterns of trumpeter hornbills ( Bycanistes bucinator ) in a fragmented landscape in South Africa. Novel GPS loggers provide high-quality location data without bias against recording long-distance movements. We found a very weakly bimodal seed-dispersal distribution …
Morphometric comparison by the ISAS
2016
DNA fragmentation has been shown to be one of the causes of male infertility, particularly related to repeated abortions, and different methods have been developed to analyze it. In the present study, two commercial kits based on the SCD technique (Halosperm® and SDFA) were evaluated by the use of the DNA fragmentation module of the ISAS® v1 CASA system. Seven semen samples from volunteers were analyzed. To compare the results between techniques, the Kruskal–Wallis test was used. Data were used for calculation of Principal Components (two PCs were obtained), and subsequent subpopulations were identified using the Halo, Halo/Core Ratio, and PC data. Results from both kits were significantly …
Simultaneous determination in situ of DNA fragmentation and 8-oxoguanine in human sperm.
2009
Deoxyribonucleic acid fragmentation and oxidative DNA damage were simultaneously determined in the same sperm cell, incubating with an 8-oxoguanine DNA probe on human spermatozoa processed by the sperm chromatin dispersion test. The assay was validated by incubation with agents that induce DNA fragmentation with or without oxidative base damage. In all samples examined, increased levels of 8-oxoguanine were present only in those spermatozoa with fragmented DNA, suggesting a link between both DNA damage types.
Effect of genistein added to bull semen after thawing on pronuclear and sperm quality.
2015
The aim of this research was to study the effect of different genistein treatments on bull sperm after thawing on pronuclear formation after in vitro fertilization (IVF) and on different sperm quality variables. Three experiments were performed. In Experiment 1, three treatments (Control, sperm incubation for 1 h at 37 degrees C with or without genistein) and two sperm concentrations during IVF (I or 3 x 10(6) sperm/mL) were evaluated to study the influence of genistein on pronuclear formation (PNF). Sperm incubation for 1 h before IVF reduced PNF regardless of sperm concentration. However, after sperm incubation and with 3 x 10(6) sperm/mL in IVF, the genistein treatment group had greater …
Swim-up procedure selects spermatozoa with longer telomere length.
2010
Telomere length and sperm DNA fragmentation were determined in sperm samples from 27 patients, using a quantitative PCR (Q-PCR) assay and the Sperm Chromatin Dispersion (SCD) test, respectively. Comparisons of the samples before and after swim-up processing demonstrated that this procedure selects a sperm population with longer average telomere size and lower frequency of sperm cells with fragmented DNA.