Loss of heterozygosity at 3p23 is correlated with poor survival in patients with colorectal carcinoma.

Background: Loss of heterozygosity (LOH) of chromosome 3p has been observed commonly in carcinomas of various tumor tissues, including colorectal carcinoma (CRC). Because there is no report analyzing 3p deletions in relation to patient prognosis in CRC, the authors investigated the prognostic value of LOH on 3p in 87 patients with sporadic CRC.

Methods: DNA samples from tumor and nontumor tissues were amplified by using polymerase chain reaction (PCR) and were analyzed for LOH on 3p using four different polymorphic human dinucleotide repeat DNA markers that map on this chromosome arm.

Suppression of vision by transcranial magnetic stimulation: a third mechanism.

We recently reported three periods when single-pulse transcranial magnetic stimulation (TMS) of the occipital pole impaired performance on a forced-choice visual letter-identification task. TMS-induced suppression during these periods is best explained by a blink-associated covering of the pupils and by a direct interference with letter-processing neural activity. We now report TMS-induced suppression at times that seem too late for the suppression to be explained by the first mechanism and too early for the suppression to be explained by the second mechanism.

Interactive image-guided surgery system with high-performance computing capabilities on low-cost workstations: a prototype.

We present a new frameless stereotatic system prototype that has been initially validated in functional neurosurgery operations and that makes use of an optical position tracker for image-guided neurosurgery. Several devices for tracking different surgical instruments have been designed and manufactured. These devices include an array of infrared light-emitting diodes that are tracked by three charge-coupled device cameras.

Nested cladistic analysis, phylogeography and speciation in the Timarcha goettingensis complex (Coleoptera, chrysomelidae).

The Timarcha goettingensis complex is a monophyletic assemblage of closely related leaf beetles (Chrysomelidae), distributed from the north half of the Iberian Peninsula to Central Europe. Oligophagy, mountainous habitat and apterism are factors which are assumed to promote speciation in these beetles. We have used cytochrome oxidase subunit II mitochondrial DNA genealogies obtained from 31 sampling localities and a nested geographical distance analysis to assess the population structure and demographic factors explaining the geographical distributions of the mtDNA haplotypes in the T.

The evolutionary history of the genus Timarcha (Coleoptera, Chrysomelidae) inferred from mitochondrial COII gene and partial 16S rDNA sequences.

The apterous genus Timarcha consists of three subgenera and more than 100 species in its Palearctic distribution, with specialized feeding on few plant families. Fifty-four sequences sampled from 31 taxa of the genus plus three outgroup leaf beetles were studied for their complete cytochrome oxidase II (COII) and a fragment of 16S rDNA mitochondrial genes, representing a total of about 1200 bp. Phylogenetic analyses using maximum-parsimony and distance methods for each gene separately and for the combined data set gave compatible topologies.

Detection of telomerase activity in human carcinomas using a trap-ELISA method: correlation with hTR and hTERT expression.

We have evaluated telomerase activity in a tumour population of 65 human cancers by using a TRAP-based method, in which detection is performed by an enzyme immunoassay (ELISA). We have corroborated that sensitivity and specificity of this new procedure can be considered similar to that of classical TRAP method, having the advantage of a rapid and reproducible analysis of large pools of samples. Thus, telomerase activity was detected in 83% of the tumours included in our population.

Differential prognosis of replication error phenotype and loss of heterozygosity in sporadic colorectal cancer.

Several distinct genetic alterations have been associated with colorectal tumorigenesis. This study investigated the frequency of microsatellite instability, also known as replication error (RER), and loss of heterozygosity (LOH) at six chromosome regions in sporadic colorectal cancer (CRC). Eighty-six tumour and paired normal mucosa samples were included in the study.

Primary hemangiopericytoma of the tibia: MR and angiographic correlation.

The Magnetic Resonance Imaging (MRI) appearances of primary osseous hemangiopericytoma (HPC) have been rarely described. We report on a 46-year-old Chinese man with primary osseous HPC of the right tibia. The characteristic vascular distribution of this tumor, presenting with a "spoke-wheel" appearance on MR images and with angiographic correlation, is described.

Failure of screening to detect HIV in a foreign laborer who died of toxoplasmosis of the central nervous system.

The most common neurologic complication in patients with acquired immunodeficiency syndrome (AIDS) is cerebral toxoplasmosis. Patients with cerebral toxoplasmosis have characteristic findings on clinical examination and neuroimaging. They require prolonged treatment and have a considerable mortality rate.

A system for the simulation and planning of orthodontic treatment using a low cost 3D laser scanner for dental anatomy capturing.

The detection and correction of malocclusions and other dental abnormalities is a significant area of work in orthodontic diagnosis. To assess the quality of occlusion between the teeth the orthodontist has to estimate distances between specific points located on the teeth of both arches. Distance measuring is based on the observation, by the orthodontist, of a plaster model of the mouth.

Oxidative stress is insignificant in N1S1-transplanted hepatoma despite markedly declined activities of the antioxidant enzymes.

It has been proposed that persistent oxidative stress accounts for the increased levels of DNA damage in cancer tissues. We have examined the profile of anti-oxidant enzymes in a transplanted hepatic tumor model by injecting N1S1 rat hepatoma cells into the liver of Sprague-Dawley rats. The transplanted N1S1 tumors displayed characteristics resembling human hepatocellular carcinoma.

Methods for the analysis of PCBs in human food, faeces and serum.

A method was developed to determine trace concentrations of a range of individual PCB congeners in biological samples (serum, food and faeces) using GC-MS, to prepare a mass balance of PCBs in humans. A simple method for the analysis of PCBs in human serum, which excluded an extraction step, was first employed. Results indicated that the recoveries of 13C12 PCB spikes were variable.

DNA amplification on chromosome 6p12 in non small cell lung cancer detected by arbitrarily primed polymerase chain reaction.

Gene amplification is clearly an important aspect of tumour growth and development and has prognostic significance in certain tumours. The identification and genetic characterisation of new areas of amplification in human malignancy remains an important goal in understanding the underlying genetic lesions within these tissues. In the present work, arbitrarily primed-PCR (AP-PCR) has been applied to detect and characterise amplified DNA fragments in human non small cell lung cancer (NSCLC).

Role of angiogenesis in hepatitis and hepatocellular carcinoma.

Background/aims: Hepatocellular carcinoma (HCC) is usually a hypervascular tumor. Factor VIII-related antigens, including von Willebrand factor, are known to be expressed in HCC, which cause capillarization of the sinusoids of HCC. Capillarization of hepatic sinusoids may play a role in hepatocarcinogenesis and its metastasis.

Exogenous hyperinsulinemia causes insulin resistance, hyperendothelinemia, and subsequent hypertension in rats.

In many clinical and animal studies, hypertension and insulin resistance coexist, but their mechanistic relationship is unclear. We explored the causal link between these two parameters in a rat model with chronic hyperinsulinemia induced with human insulin (1 U/d) released from subcutaneously implanted minipumps. Rats with saline minipumps served as a control.

Mitochondrial DNA phylogeny and the evolution of host-plant use in palearctic Chrysolina (Coleoptera, Chrysomelidae) leaf beetles.

The genus Chrysolina consists of specialized phytophagous leaf-beetles (Coleoptera, Chrysomelidae) with feed on several plant families. There is no explicit phylogenetic hypothesis available for this genus, which includes 65 subgenera and more than 400 species with a wide distribution. We obtained 839-bp sequence data from the 16S rDNA and cytochrome oxidase subunit I (COI) mitochondrial genes.

Overexpression of vascular endothelin-1 and endothelin-A receptors in a fructose-induced hypertensive rat model.

Objective: To examine the temporal relationship between hyperinsulinemia and hypertension in the fructose-hypertensive rat model and to study the function of endothelin-1 (ET-1) in fructose-induced hypertension.

Design: Since ET-1 induces insulin resistance in conscious rats, we tested the hypothesis that both hyperinsulinemia and hypertension developed in the fructose-hypertensive rat model might be the sequelae of an elevated tissue content of ET-1 and ET(A) receptors.

Materials And Methods: Systolic hypertension was induced within 3 weeks in male Sprague-Dawley rats fed on a fructose-rich diet.

Evidence that endothelin-1 (ET-1) inhibits insulin-stimulated glucose uptake in rat adipocytes mainly through ETA receptors.

The specificity of endothelin (ET) receptors involved in the inhibition of insulin-stimulated glucose uptake (ISGU) in rat adipocytes was investigated. Adipocytes were isolated from the epididymal fat pads of Sprague-Dawley rats. To determine receptor subtypes, we used three ET isopeptides, ET-1 and ET-2, both of which are nonselective agonists, and ET-3, a selective agonist for ETC receptors, to displace [125I]ET-1 binding from the fat cells.

Menadione (vitamin K3) enhances the mitogenic signal of epidermal growth factor via extracellular signal-regulated kinases.

The effects of vitamin K3 (VK3) on DNA synthesis, cell proliferation and mitogen-activated protein kinase pathway were investigated in G0-arrested NIH 3T3 fibroblasts. VK3 (5 microM) alone stimulates DNA synthesis by 40% and moderately increases the mitogenic effects of EGF, which is preceded by a rapid phosphorylation of the extracellular signal-regulated kinases (ERKs). At 20 microM, VK3 had an antiproliferative effect.

p53 exon 7 mutations as a predictor of poor prognosis in patients with colorectal cancer.

We have studied 61 resected colorectal adenocarcinomas in order to investigate p53 mutations as a prognostic factor for this pathology. Mutations in exons 5-9 of the p53 gene were analyzed by the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) technique followed by sequencing. Our data indicate that p53 exon 7 mutations were prevalent in the latest stages of colorectal carcinogenesis and patients bearing this alteration had the worst prognosis.

Genetic abnormalities and microsatellite instability in colorectal cancer.

Our purpose was to investigate different genetic abnormalities, such as K-ras mutations, p53 alterations, and c-myc RNA overexpression, as well as microsatellite instability in 63 colorectal tumors obtained from patients that had undergone surgery. K-ras point mutations were analyzed by PCR-RFLP technique, followed by sequencing; p53 protein accumulation by immunohistochemistry; p53 gene mutations in exons 5-9 were studied by the SSCP and sequencing techniques, and c-myc overexpression by Northern blot. Microsatellite instability was performed at chromosomes 2p, 3p, and 11p by a PCR-based technique.

Prognostic significance of p53 gene mutations in squamous cell carcinoma of the lung.

The aim of the present study was to analyze the prevalence and clinical importance of p53 gene mutations in surgically treated squamous cell lung carcinoma. Sixty patients were included. Fifty-one patients in stages I to IIIa were submitted to radical resection.

Prognostic value of genomic damage in non-small-cell lung cancer.

Genomic alterations have been analysed in 65 non-small-cell lung cancer (NSCLC) tissue samples by using the arbitrarily primed polymerase chain reaction (AP-PCR), which is a PCR-based genomic fingerprinting. We have shown that AP-PCR may be applied as a useful and feasible practical method for detection of the genomic alterations that accompany malignancy in NSCLC. Genomic changes detected by us consisted of: allelic losses or gains in anonymous DNA sequences, homozygously deleted DNA sequences and polymorphic DNA sequences.

Comparative survival analysis of p53 gene mutations and protein accumulation in colorectal cancer.

Immunohistochemical reactivity for p53 protein is common in various human malignancies. Increased intracellular concentration of p53, which is frequently, but not systematically, related to p53 mutation, has been proposed to be associated with poor prognosis in some tumor types. In colorectal cancer, this significance is still a matter of debate.

Up-regulation of beta-actin, cyclophilin and GAPDH in N1S1 rat hepatoma.

Beta-actin, cyclophilin and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) are all constantly expressed proteins that regulate cellular structures and endogenous cytoarchitectural functions. In this study, we used an in vivo N1S1 rat hepatoma model to examine changes in the expression levels of these housekeeping genes in normal and tumor liver samples. The beta-actin, cyclophilin and GAPDH genes were all up-regulated in tumor groups as compared to the controls.