254 research outputs found
Analysis of extended genomic rearrangements in oncological research.
Screening for genomic rearrangements is a fundamental task in the genetic diagnosis of many inherited
disorders including cancer-predisposing syndromes. Several methods were developed for analysis of structural
genomic abnormalities, some are targeted to the analysis of one or few specific loci, others are designed to
scan the whole genome. Locus-specific methods are used when the candidate loci responsible for the specific
pathological condition are known. Whole-genome methods are used to discover loci bearing structural
abnormalities when the disease-associated locus is unknown. Three main approaches have been employed for
the analysis of locus-specific structural changes. The first two are based on probe hybridization and include
cytogenetics and DNA blotting. The third approach is based on PCR amplification and includes microsatellite or
single nucleotide polymorphism (SNP) genotyping, relative allele quantitation, real-time quantitative PCR, long
PCR and multiplex PCR-based methods such as multiplex ligation-dependent probe amplification and the
recently developed nonfluorescent multiplex PCR coupled to high-performance liquid chromatography analysis.
Whole-genome methods include cytogenetic methods, array-comparative genomic hybridization, SNP array
and other sequence-based methods. The goal of the present review is to provide an overview of the main
features and advantages and limitations of methods for the screening of structural genomic abnormalities
relevant to oncological research
Domain-Wall Free-Energy of Spin Glass Models:Numerical Method and Boundary Conditions
An efficient Monte Carlo method is extended to evaluate directly domain-wall
free-energy for randomly frustrated spin systems. Using the method, critical
phenomena of spin-glass phase transition is investigated in 4d +/-J Ising model
under the replica boundary condition. Our values of the critical temperature
and exponent, obtained by finite-size scaling, are in good agreement with those
of the standard MC and the series expansion studies. In addition, two
exponents, the stiffness exponent and the fractal dimension of the domain wall,
which characterize the ordered phase, are obtained. The latter value is larger
than d-1, indicating that the domain wall is really rough in the 4d Ising spin
glass phase.Comment: 9 pages Latex(Revtex), 8 eps figure
Gastric adenomas: relationship between clinicopathological findings, Helicobacter pylori infection, APC mutations and COX-2 expression.
Gastric adenomas are rare neoplastic growths characterized by localized polypoid proliferations of dysplastic epithelium that tend to progress to infiltrating adenocarcinoma. Therefore, the identification of molecular markers that could reliably recognize adenomas at risk of progression is advocated in the clinical management. In this study we investigated, in a series of gastric adenoma specimens from an area at high risk of gastric cancer, the relationship between clinicopathological characteristics of adenoma and Helicobacter pylori infection, APC mutational status, and COX-2 and the down-stream enzyme mPGES1 expression. Helicobacter pylori infection, detected in 24%, and 33% by histology and PCR analyses, respectively, did not show any relationship with growth pattern, localization, size, dysplasia grade and presence of synchronous cancer. Pathogenetic mutations of MCR region (codons 1269-1589) of the APC gene were detected only in one case corresponding to a single, small size, low grade, H. pylori-negative adenoma. The expression of COX-2 largely matched that of mPGES(1). Both were overexpressed in 79% of cases showing a relationship with high-grade dysplasia, size >10 mm and presence of a synchronous carcinoma. In conclusion, COX-2 may play a key role in the development and progression of gastric adenoma and could be an attractive target in the management of gastric adenoma at major risk of cancer development
Fertilization induces a transient exposure of phosphatidylserine in mouse eggs
Phosphatidylserine (PS) is normally localized to the inner leaflet of the plasma membrane and the requirement of PS translocation to the outer leaflet in cellular processes other than apoptosis has been demonstrated recently. In this work we investigated the occurrence of PS mobilization in mouse eggs, which express flippase Atp8a1 and scramblases Plscr1 and 3, as determined by RT-PCR; these enzyme are responsible for PS distribution in cell membranes. We find a dramatic increase in binding of flouresceinated-Annexin-V, which specifically binds to PS, following fertilization or parthenogenetic activation induced by SrCl2 treatment. This increase was not observed when eggs were first treated with BAPTA-AM, indicating that an increase in intracellular Ca2+ concentration was required for PS exposure. Fluorescence was observed over the entire egg surface with the exception of the regions overlying the meiotic spindle and sperm entry site. PS exposure was also observed in activated eggs obtained from CaMKIIγ null females, which are unable to exit metaphase II arrest despite displaying Ca2+ spikes. In contrast, PS exposure was not observed in TPEN-activated eggs, which exit metaphase II arrest in the absence of Ca2+ release. PS exposure was also observed when eggs were activated with ethanol but not with a Ca2+ ionophore, suggesting that the Ca2+ source and concentration are relevant for PS exposure. Last, treatment with cytochalasin D, which disrupts microfilaments, or jasplakinolide, which stabilizes microfilaments, prior to egg activation showed that PS externalization is an actin-dependent process. Thus, the Ca2+ rise during egg activation results in a transient exposure of PS in fertilized eggs that is not associated with apoptosis.Fil: Curia, Claudio Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Ernesto, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Stein, Paula. University of Pennsylvania; Estados UnidosFil: Busso, Dolores. Pontificia Universidad Católica de Chile; ChileFil: Schultz, Richard. University of Pennsylvania; Estados UnidosFil: Cuasnicu, Patricia Sara. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Cohen, Debora Juana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); Argentin
Protective but Not Anticonvulsant Effects of Ghrelin and JMV-1843 in the Pilocarpine Model of Status epilepticus.
In models of status epilepticus ghrelin displays neuroprotective effects mediated by the growth hormone secretagogue-receptor 1a (GHS-R1a). This activity may be explained by anticonvulsant properties that, however, are controversial. We further investigated neuroprotection and the effects on seizures by comparing ghrelin with a more effective GHS-R1a agonist, JMV-1843. Rats were treated either with ghrelin, JMV-1843 or saline 10 min before pilocarpine, which was used to induce status epilepticus. Status epilepticus, developed in all rats, was attenuated by diazepam. No differences were observed among the various groups in the characteristics of pilocarpine-induced seizures. In saline group the area of lesion, characterized by lack of glial fibrillary acidic protein immunoreactivity, was of 0.45\ub10.07 mm2 in the hippocampal stratum lacunosum-moleculare, and was accompanied by upregulation of laminin immunostaining, and by increased endothelin-1 expression. Both ghrelin (P<0.05) and JMV-1843 (P<0.01) were able to reduce the area of loss in glial fibrillary acidic protein immunostaining. In addition, JMV-1843 counteracted (P<0.05) the changes in laminin and endothelin-1 expression, both increased in ghrelin-treated rats. JMV-1843 was able to ameliorate neuronal survival in the hilus of dentate gyrus and medial entorhinal cortex layer III (P<0.05 vs saline and ghrelin groups). These results demonstrate diverse protective effects of growth hormone secretagogues in rats exposed to status epilepticus
Oral Porphyromonas gingivalis and Fusobacterium nucleatum Abundance in Subjects in Primary and Secondary Cardiovascular Prevention, with or without Heterozygous Familial Hypercholesterolemia
Background: Low-grade chronic inflammation, promoted by dysbiosis of the gut and oral microbiota, has been shown to contribute to individual susceptibility to atherosclerotic cardiovascular disease (ASCVD). High oral Porphyromonas gingivalis (Pg) and lower Fusobacterium nucleatum (Fn) concentrations have been associated with clinical and experimental atherosclerosis. We assessed oral Pg and Fn abundance in very high-risk patients with previously diagnosed ASCVD, with or without heterozygous familial hypercholesterolemia (HeFH), in subjects with HeFH in primary prevention and in healthy subjects. Methods: In this cross-sectional study, 40 patients with previously diagnosed ASCVD (10 with genetically proven HeFH, and 30 without FH), 26 subjects with HeFH in primary prevention, and 31 healthy subjects were selected to quantify oral Pg and Fn abundance by qPCR and assess oral health status. Results: Compared to healthy subjects, patients with previously diagnosed ASCVD showed greater Pg abundance (1101.3 vs. 192.4, p = 0.03), but similar Fn abundance. HeFH patients with ASCVD had an even greater Pg abundance than did non-HeFH patients and healthy subjects (1770.6 vs. 758.4 vs. 192.4, respectively; p = 0.048). No differences were found in the levels of Pg and Fn abundance in HeFH subjects in primary prevention, as compared to healthy subjects. Conclusions: Greater oral Pg abundance is present in very high-risk patients with previously diagnosed ASCVD, with or without FH, suggesting a potential relationship with CV events. Future studies will assess the predictive value of Pg abundance measurement in ASCVD risk stratification
Two minimally invasive strategies to implant guide cannulas for multiple injections in deep brain areas
Temporal lobe epilepsy (TLE) is characterized by seizures that originate in temporal structures and that are pharmacoresistant in ∼ 40 % of patients. In the context of a preclinical study aimed at developing an innovative therapy to treat TLE, we needed to perform multiple intracranial injections in the rat ventral CA3 (vCA3). To reduce invasiveness and to increase the precision reproducibility when multiple injections are performed over time, we opted for the implantation of guide cannulas. In the conventional approach, the guide cannula is implanted close to the target zone damaging the brain tissue along the route of the cannula insertion. This is a particularly relevant issue in our study because vCA3 is situated deep in the rat brain. The damage caused by the standard procedure would severely compromise the integrity of the hippocampal tissue necessary for the effectiveness of the therapeutic intervention. To overcome this problem, we developed, in TLE adult rats, two novel approaches to implant guide cannulas more superficially: the “above dentate gyrus (DG)” and the “above hippocampus (HPC)” strategies. The target brain area was then reached with the thinner infusion needle, resulting in minimally invasive approaches. We demonstrated by immunofluorescence that both novel surgical approaches enable injections of different agents into the ventral hippocampus with excellent precision and reproducibility. Being this aspect comparable between the two approaches, we concluded that the “above HPC” strategy must be preferred due to its lower invasiveness. Behavioral tests confirmed that memory, locomotion and anxiety level were not affected by the cannula-induced damage
Increase of circulating cell free mitochondrial DNA in amateur boxers after sparring matches
Objectives: To determine if circulating mitochondrial deoxyribonucleic acid levels increase after sport activity involving blows to the head, such as boxing, and if it could play a role in inflammatory cascade regulation in response to trauma. Design: Observational, longitudinal. Methods: We measured mitochondrial deoxyribonucleic acid levels and integrity in ten non-professional male boxers before and after three weekly sparring matches. We set up a protocol to separate three different plasma fractions enriched in mitochondria-containing vesicles, mitochondrial deoxyribonucleic acid bound to proteins and naked mitochondrial deoxyribonucleic acid. We quantified the levels of the main cytokines involved in inflammatory response and the levels of neurofilament light, a well-known marker of brain damage. Results: Circulating mitochondrial deoxyribonucleic acid levels increased after each match. In the second fraction, we also observed an increase over the weeks. Mitochondrial deoxyribonucleic acid is less intact after each match if compared with pre-match integrity, especially the naked form which is not protected within vesicles or mitochondria. Circulating levels of interleukin-6, interleukin-1beta and interleukin-10 increased after each match linking traumatic brain injuries to inflammatory state. Neurofilament light chain showed a similar trend to mitochondrial deoxyribonucleic acid. Conclusions: As mitochondrial deoxyribonucleic acid displays an inflammatory effect and neurofilament light chain is more specific for brain injury, we concluded that the simultaneous analysis of these two parameters could be helpful to monitor the effects of traumatic brain injury in contact sports, and that mitochondrial deoxyribonucleic acid is a promising candidate biomarker to study the inflammatory state of patients who suffered repeated traumatic brain injuries
APC gene mutations and colorectal adenomatosis in familial adenomatous polyposis
Correlations between germline APC mutation sites and colorectal pathophenotypes, as evaluated by the direct count of adenomas at colectomy, were investigated analysing colectomy specimens from 29 FAP patients carrying one mis-sense (codon 208) and 14 frame-shift or non-sense APC mutations (codons 232, 367, 437, 623, 876, 995, 1061, 1068, 1075, 1112, 1114, 1309, 1324, 1556). The mis-sense mutation at codon 208 was associated with a relatively mild colorectal pathophenotype. The mutation at codon 367, subject to alternative splicing, was associated with attenuated FAP. The mutation at codon 1309 was associated with the profuse colorectal adenomatosis. For 13 mutations, predicted to result in null alleles or truncated APC proteins, we correlated density and distribution of colorectal adenomas with the predicted functional effects of the mutation. The most severe colorectal pathophenotype was significantly associated with the truncating mutation at codon 1309, which is located downstream to the I β-catenin binding domain but upstream II β-catenin-binding domain. Mutations between codons 867 and 1114, which affect the I β-catenin binding domain, as well as mutations occurring in exons 6 and 9, predicted to result in null alleles, were associated with a less severe colorectal pathophenotype. Overall, the highest number of adenomas was detected in the right colon, followed by the left colon, transverse colon sigma and rectum. However, the highest density of adenomas was observed in the left colon, followed by the right colon, sigma, transverse colon and rectum. Colorectal carcinomas, observed in only five patients, were all in the left colon. © 2000 Cancer Research Campaig
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