988 resultados para biological marker


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Angiostrongylus cantonensis is the etiologic agent of eosinophilic meningoencephalitis in humans. Cases have been recorded in many parts of the world, including Brazil. The aim of this study was to compare the differences in the biology and morphology of two different Brazilian haplotypes of A. : ac8 and ac9. A significantly larger number of L1 larvae eliminated in the faeces of rodents at the beginning of the patent period was observed for ac9 haplotype and compared to the total of L1 larvae eliminated, there was a significant difference between the two haplotypes. The ac9 haplotype showed a significant difference in the proportion of female and male specimens (0.6:1), but the same was not observed for ac8 (1.2:1). The morphometric analysis showed that male and female specimens isolated from ac8 haplotype were significantly larger with respect to body length, oesophagus length, spicule length (male) and distance from the anus to the rear end (female) compared to specimens from ac9. The morphological analysis by light microscopy showed little variation in the level of bifurcations at the lateral rays in the right lobe of the copulatory bursa between the two haplotypes. The biological, morphological and morphometric variations observed between the two haplotypes agree with the observed variation at the molecular level using the cytochrome oxidase subunit I marker and reinforce the possible influence of geographical isolation on the development of these haplotypes.

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A heterogeneous group of 159 tumours was studied for the presence of S-100 protein by the immunoperoxidase technique in order to determine whether this marker may be of value in facilitating immunocytochemical diagnosis. Among cases of melanocytic and pigmented lesions, S-100 was widely distributed and demonstrated the strongest degrees of reactivity. S-100 protein was identified in virtually all nerve sheath tumours such as schwannomas, neurofibromas, myxoid sheath nerve tumour and also in some tumours of controversial histogenesis such as granular cell tumours. The great majority of carcinomas did not express S-100, with only two cases of breast carcinoma displaying focal S-100 staining. In a miscellaneous group of tumours S-100 was demonstrated in chordomas, myoepitheliomas and Wilms' tumour with Schwann cell differentiation. Despite its presence in a wide array of cell types, S-100 protein continues to be an extremely useful marker especially for soft tissue and peripheral nervous system tumours.

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The banana weevil Cosmopolites sordidus (Germar) is one of a number of pests that attack banana crops. The use of the entomopathogenic fungus Beauveria bassiana as a biological control agent for this pest may contribute towards reducing the application of chemical insecticides on banana crops. In this study, the genetic variability of a collection of Brazilian isolates of B. bassiana was evaluated. Samples were obtained from various geographic regions of Brazil, and from different hosts of the Curculionidae family. Based on the DNA fingerprints generated by RAPD and AFLP, we found that 92 and 88 % of the loci were polymorphic, respectively. The B. bassiana isolates were attributed to two genotypic clusters based on the RAPD data, and to three genotypic clusters, when analyzed with AFLP. The nucleotide sequences of nuclear ribosomal DNA intergenic spacers confirmed that all isolates are in fact B. bassiana. Analysis of molecular variance showed that variability among the isolates was not correlated with geographic origin or hosts. A RAPD-specific marker for isolate CG 1024, which is highly virulent to C. sordidus, was cloned and sequenced. Based on the sequences obtained, specific PCR primers BbasCG1024F (5'-TGC GGC TGA GGA GGA CT-3') and BbasCG1024R (5'-TGC GGC TGA GTG TAG AAC-3') were designed for detecting and monitoring this isolate in the field.

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In this study the population structure and connectivity of the Mediterranean and Atlantic Raja clavata (L., 1758) were investigated by analyzing the genetic variation of six population samples (N = 144) at seven nuclear microsatellite loci. The genetic dataset was generated by selecting population samples available in the tissue databases of the GenoDREAM laboratory (University of Bologna) and of the Department of Life Sciences and Environment (University of Cagliari), all collected during past scientific surveys (MEDITS, GRUND) from different geographical locations in the Mediterranean basin and North-east Atlantic sea, as North Sea, Sardinian coasts, Tuscany coasts and Cyprus Island. This thesis deals with to estimate the genetic diversity and differentiation among 6 geographical samples, in particular, to assess the presence of any barrier (geographic, hydrogeological or biological) to gene flow evaluating both the genetic diversity (nucleotide diversity, observed and expected heterozygosity, Hardy- Weinberg equilibrium analysis) and population differentiation (Fst estimates, population structure analysis). In addition to molecular analysis, quantitative representation and statistical analysis of morphological individuals shape are performed using geometric morphometrics methods and statistical tests. Geometric coordinates call landmarks are fixed in 158 individuals belonging to two population samples of Raja clavata and in population samples of closely related species, Raja straeleni (cryptic sibling) and Raja asterias, to assess significant morphological differences at multiple taxonomic levels. The results obtained from the analysis of the microsatellite dataset suggested a geographic and genetic separation between populations from Central-Western and Eastern Mediterranean basins. Furthermore, the analysis also showed that there was no separation between geographic samples from North Atlantic Ocean and central-Western Mediterranean, grouping them to a panmictic population. The Landmark-based geometric morphometry method results showed significant differences of body shape able to discriminate taxa at tested levels (from species to populations).

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Plasmons in metal nanoparticles respond to changes in their local environment by a spectral shift in resonance. Here, the potential of plasmonic metal nanoparticles for label-free detection and observation of biological systems is presented. Comparing the material silver and gold concerning plasmonic sensitivity, silver nanoparticles exhibit a higher sensitivity but their chemical instability under light exposure limits general usage. A new approach combining results from optical dark-field microscopy and transmission electron microscopy allows localization and quantification of gold nanoparticles internalized into living cells. Nanorods exposing a negatively charged biocompatible polymer seem to be promising candidates to sense membrane fluctuations of adherent cells. Many small nanoparticles being specific sensing elements can build up a sensor for parallel analyte detection without need of labeling, which is easy to fabricate, re-usable, and has sensitivity down to nanomolar concentrations. Besides analyte detection, binding kinetics of various partner proteins interacting with one protein of interest are accessible in parallel. Gold nanoparticles are able to sense local oscillations in the surface density of proteins on a lipid bilayer, which could not be resolved so far. Studies on the fluorescently labeled system and the unlabeled system identify an influence of the label on the kinetics.

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AIMS: To evaluate the expression of matrix metalloproteinase-19 (MMP-19) in oropharyngeal squamous cell carcinoma along with its association with structural features of invasiveness. To investigate whether MMP-19 expression correlates with lymphatic or systemic metastasis and prognosis in patients who have received definitive radiotherapy. METHODS AND RESULTS: The histological evaluation of the invasive front was based on Bryne's malignancy grading system. We correlated the immunohistochemical expression pattern with morphological parameters which characterize tumor invasiveness such as keratinization, nuclear polymorphism, invasion pattern, and the host inflammatory response. Local immunoreactivity for MMP-19 was positively correlated with tumor invasiveness as reflected in its structural characteristics and the degree of nuclear polymorphism, and negatively correlated with the inflammatory response of the host. No correlation existed between MMP-19 expression and clinicopathological features (TNM stage, grade of differentiation) or a patient''s outcome and prognosis. CONCLUSIONS: This latter finding probably reflects the unique change for MMPs from high immunoreactivity within healthy tissue areas and non-invasive tumor parts, through absence in the least invasive neoplastic regions, to strong re-expression at a highly invasive front of the same tumor. Our findings indicate that MMP-19 can be used as a marker for tumor invasiveness in patients with oropharyngeal squamous cell carcinoma.

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In addition to self reports and questionnaires, biomarkers are of relevance in the diagnosis of and therapy for alcohol use disorders. Traditional biomarkers such as gamma-glutamyl transpeptidase or mean corpuscular volume are indirect biomarkers and are subject to the influence of age, gender and non-alcohol related diseases, among others. Direct metabolites of ethanol such as Ethyl glucuronide (EtG), ethyl sulphate (EtS) and phosphatidylethanol (PEth) are direct metabolites of ethanol, that are positive after intake of ethyl alcohol. They represent useful diagnostic tools for identifying alcohol use even more accurately than traditional biomarkers. Each of these drinking indicators remains positive in serum and urine for a characteristic time spectrum after the cessation of ethanol intake - EtG and EtS in urine up to 7 days, EtG in hair for months after ethanol has left the body. Applications include clinical routine use, emergency room settings, proof of abstinence in alcohol rehabilitation programmes, driving under influence offenders, workplace testing, assessment of alcohol intake in the context of liver transplantation and foetal alcohol syndrome. Due to their properties, they open up new perspectives for prevention, interdisciplinary cooperation, diagnosis of and therapy for alcohol-related problems.

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Uridine-rich small nuclear (U snRNAs), with the exception of the U6 snRNA, are RNA polymerase II (RNAPII) transcripts. The mechanism of 3’ cleavage of snRNAs has been unknown until recently. This area was greatly advanced when 12 of the Integrator complex subunits (IntS) were purified in 2005 through their interaction with the C-terminal domain (CTD) of the large subunit (RpbI) of RNAPII. Subsequently, our lab performed a genome-wide RNAi screen that identified two more members of the complex that we have termed IntS13 and IntS14. We have determined that IntS9 and 11 mediate the 3’ cleavage of snRNAs, but the exact function of the other subunits remains unknown. However, through the use of a U7 snRNA-GFP reporter and RNAi knockdown of the Integrator subunits in Drosophila S2 cells, we have shown that all subunits are required for the proper processing of snRNAs, albeit to differing degrees. Because snRNA transcription takes place in the nucleus of the cell, it is expected that all of the Integrator subunits would exhibit nuclear localization, but the knowledge of discrete subnuclear localization (i.e. to Cajal bodies) of any of the subunits could provide important clues to the function of that subunit. In this study, we used a cell biological approach to determine the localization of the 14 Integrator subunits. We hypothesized that the majority of the subunits would be nuclear, however, a few would display distinct localization to the Cajal bodies, as this is where snRNA genes are localized and transcribed. The specific aims and results are: 1. To determine the subcellular localization of the 14 Integrator subunits. To accomplish this, mCherry and GFP tagged clones were generated for each of the 14 Drosophila and human Integrator subunits. Confocal microscopy studies revealed that the majority of the subunits were diffuse in the nucleus, however, IntS3 formed discrete subnuclear foci. Surprisingly, two of the subunits, IntS2 and 7 were observed in cytoplasmic foci. 2. To further characterize Integrator subunits with unique subcellular localizations. Colocalization studies with endogenous IntS3 and Cajal body marker, coilin, showed that these two proteins overlap, and from this we concluded that IntS3 localized to Cajal bodies. Additionally, colocalization studies with mCherry-tagged IntS2 and 7 and the P body marker, Dcp1, revealed that these proteins colocalize as well. IntS7, however, is more stable in cytoplasmic foci than Dcp1. It was also shown through RNAi knockdown of Integrator subunits, that the cytoplasmic localization of IntS2 and 7 is dependent on the expression of IntS1 and 11 in S2 cells.

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Head and neck cancer constitutes the 6th most common malignancy worldwide and affects the crucial anatomical structures and physiological functions of the upper aerodigestive tract. Classical therapeutic strategies such as surgery and radiotherapy carry substantial toxicity and functional impairment. Moreover, the loco-regional control rates as well as overall survival still need to be improved in subgroups of patients. The scatter-factor/hepatocyte growth factor receptor tyrosine kinase MET is an established effector in the promotion, maintenance and progression of malignant transformation in a wide range of human malignancies, and has been gaining considerable interest in head and neck cancer over the last 15 years. Aberrant MET activation due to overexpression, mutations, tumor-stroma paracrine loops, and cooperative/redundant signaling has been shown to play prominent roles in epithelial-to-mesenchymal transition, angiogenesis, and responses to anti-cancer therapeutic modalities. Accumulating preclinical and translational evidence highly supports the increasing interest of MET as a biomarker for lymph node and distant metastases, as well as a potential marker of stratification for responses to ionizing radiation. The relevance of MET as a therapeutic molecular target in head and neck cancer described in preclinical studies remains largely under-evaluated in clinical trials, and therefore inconclusive. Also in the context of anti-cancer targeted therapy, a large body of preclinical data suggests a central role for MET in treatment resistance towards multiple therapeutic modalities in malignancies of the head and neck region. These findings, as well as the potential use of combination therapies including MET inhibitors in these tumors, need to be further explored.

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PURPOSE To assess endometrial gene as well as protein expression of neuroendocrine and supposedly endometriosis-associated product PGP9.5 and pain symptoms in women with endometriosis and controls undergoing laparoscopy, using molecular biological and immuno-histochemical approaches in the same patients. METHODS Biopsy of eutopic endometrium from 29 patients by sharp curettage, and preparation of paraffin blocks. Determination of PGP9.5 gene expression and protein abundance using qPCR and immuno-histochemistry. RESULTS qPCR; The PGP9.5 mRNA expression level between women with (N = 16) and without (N = 13) endometriosis was not different, regardless of pain symptoms or menstrual cycle phase. PGP9.5 expression was higher in women who reported pain compared to those who did not; however, this association was not statistically significant. The expression of PGP9.5 mRNA was higher in women with endometriosis and pain during the proliferative than in the secretory phase (P = 0.03). Furthermore, in the first half of the cycle, the abundance of the PGP9.5 transcript was also significantly higher in endometriosis patients compared to those without (P = 0.03). Immuno-histochemistry; Thirteen of the 16 endometriosis patients showed positive PGP9.5 immuno-reactivity in the endometrium, whereas no such signal was observed in women without endometriosis. The absolute number of nerve fibres per mm(2) in women with endometriosis was similar, regardless of the pain symptoms. CONCLUSIONS PGP9.5 mRNA expression is increased in the proliferative phase of endometriotic women with pain. The presence of nerve fibres was demonstrated by a PGP9.5 protein signal in immuno-histochemistry and restricted to patients with endometriosis. Based on these results, however, there did not appear to be a direct association between the gene expression and protein abundance in women with and without endometriosis or those that experienced pain.

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Carcinomas that arise from the ovarian surface epithelium represent a great challenge in gynecologic oncology. Although the prognosis of ovarian cancer is influenced by many factors capable of predicting clinical outcome, including tumor stage, pathological grade, and amount of residual disease following primary surgery, the biological aspects of ovarian cancer are not completely understood, thus implying that there may be other predictive indicators that could be used independently or in conjunction with these factors to provide a clearer clinical picture. The identification of additional markers with biological relevance is desirable. To identify disease-associated peptides, a phage display random peptide library was used to screen immunoglobulins derived from a patient with ovarian cancer. One peptide was markedly enriched following three rounds of affinity selection. The presence of autoantibodies against the peptide was examined in a panel of ovarian cancer patients. Stage IV patients exhibited a high percentage of positive reactivity (59%). This was in contrast to stage III patients, who only displayed 7% positive reactivity. Antibodies against the peptide were affinity purified, and heat-shock protein 90 (Hsp90) was identified as the corresponding autoantigen. The expression profile of the identified antigen was determined. Hsp90 was expressed in all sections examined regardless of degree of anaplasia. This thesis shows that utilizing the humoral response to ovarian cancer can be used to identify a tumor antigen in ovarian cancer. The data show that certain antigens may be expressed in ovarian tumors independent of the disease stage or grade, whereas circulating antibodies against such epitopes are only found in a subset of patients. ^

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Perhaps the most striking fact about early Cenozoic avian history some 70 million years ago was the rapid radiation of large, flightless, ground-living birds. It has been suggested that, for a time, there was active competition between these large terrestrial birds and the early mammals. Probably reflecting the above noted early start of Ratitae of the infraclass Eoaves, the presumptive sex chromosomes of their present day survivors, such as the emu and the ostrich, largely remained homomorphic. The signs of genetic differentiation between their still-homomorphic Z and W chromosomes were tested by using two marker genes (Z-linked ZOV3 and the gene for the iron-responsive element-binding protein) and one marker sequence of a part of a presumptive pseudogene (W-linked EE0.6 of the chicken). Their homologues, maintaining 71–92% identities to the chicken counterparts, were found in both the emu (Dromaius novaehollandiae) and the ostrich (Struthio camelus). Their locations were visualized on chromosome preparations by fluorescence in situ hybridization. In the case of the emu, these three marker sequences were localized on both members of the fifth pair of a female, thus revealing no sign yet of genetic differentiation between the Z and the W. The finding was the same with regard to both members of the fourth pair of male ostriches. In the female ostrich, however, the sequence of the gene for the iron-responsive element-binding protein was missing from one of the pairs, thus revealing the differentiation by a small deletion of the W from the Z.

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A computational system for the prediction of polymorphic loci directly and efficiently from human genomic sequence was developed and verified. A suite of programs, collectively called pompous (polymorphic marker prediction of ubiquitous simple sequences) detects tandem repeats ranging from dinucleotides up to 250 mers, scores them according to predicted level of polymorphism, and designs appropriate flanking primers for PCR amplification. This approach was validated on an approximately 750-kilobase region of human chromosome 3p21.3, involved in lung and breast carcinoma homozygous deletions. Target DNA from 36 paired B lymphoblastoid and lung cancer lines was amplified and allelotyped for 33 loci predicted by pompous to be variable in repeat size. We found that among those 36 predominately Caucasian individuals 22 of the 33 (67%) predicted loci were polymorphic with an average heterozygosity of 0.42. Allele loss in this region was found in 27/36 (75%) of the tumor lines using these markers. pompous provides the genetic researcher with an additional tool for the rapid and efficient identification of polymorphic markers, and through a World Wide Web site, investigators can use pompous to identify polymorphic markers for their research. A catalog of 13,261 potential polymorphic markers and associated primer sets has been created from the analysis of 141,779,504 base pairs of human genomic sequence in GenBank. This data is available on our Web site (pompous.swmed.edu) and will be updated periodically as GenBank is expanded and algorithm accuracy is improved.