High resolution chromosome 3p, 8p, 9q and 22q allelotyping analysis in the pathogenesis of gallbladder carcinoma

Our recent genome-wide allelotyping analysis of gallbladder carcinoma identified 3p, 8p, 9q and 22q as chromosomal regions with frequent loss of heterozygosity. The present study was undertaken to more precisely identify the presence and location of regions of frequent allele loss involving those chromosomes in gallbladder carcinoma. Microdissected tissue from 24 gallbladder carcinoma were analysed for PCR-based loss of heterozygosity using 81 microsatellite markers spanning chromosome 3p (n=26), 8p (n=14), 9q (n=29) and 22q (n=12) regions. We also studied the role of those allele losses in gallbladder carcinoma pathogenesis by examining 45 microdissected normal and dysplastic gallbladder epithelia accompanying gallbladder carcinoma, using 17 microsatellite markers. Overall frequencies of loss of heterozygosity at 3p (100%), 8p (100%), 9q (88%), and 22q (92%) sites were very high in gallbladder carcinoma, and we identified 13 distinct regions undergoing frequent loss of heterozygosity in tumours. Allele losses were frequently detected in normal and dysplastic gallbladder epithelia. There was a progressive increase of the overall loss of heterozygosity frequency with increasing severity of histopathological changes. Allele losses were not random and followed a sequence. This study refines several distinct chromosome 3p, 8p, 9q and 22q regions undergoing frequent allele loss in gallbladder carcinoma that will aid in the positional identification of tumour suppressor genes involved in gallbladder carcinoma pathogenesis

Distinctive autofluorescence of urine samples from individuals with bacteriuria compared with normals

Background A variety of fluorophores are present in normal human urine. Alteration in the autofluorescence of urine could result from physiological or pathological changes. Method This study investigates the differences in the autofluorescence of 45 normal urine samples from 25 individuals with bacteriuria. Results Excitation at 290 nm showed good discrimination between these 2 groups. Principal Component Analysis (PCA) of the data revealed statistically significant differences between the fluorescence spectra for samples with bacteriuria as compared to the control group. Conclusion The findings indicate the potential of the fluorescence spectrum of urine to be developed as a simple and rapid diagnostic tool.3 page(s

Table S1 from How to get the most bang for your buck: the evolution and physiology of nutrition-dependent resource allocation strategies

Examples of the diversity of resource allocation strategies in some life history traits across the animal kingdom

Visible 532 nm laser irradiation of human adipose tissue-derived stem cells : effect on proliferation rates, mitochondria membrane potential and autofluorescence

Background and Objective: The photobiological effect of laser light on cells and tissues originates from light absorption by endogenous chromophores and hence it depends on the wavelength of light source and cell type. Earlier studies regarding the biostimulation effects of green laser light investigated a wide variety of cells but not adipose tissue-derived stem cells (ADSCS). In this study we reported the in vitro effect of 532-nm Nd:YAG laser on proliferation, mitochondrial activity of these mesenchymal stem cells (MSCs) on the autofluorescence emission at wavelengths associated with nicotinamide adenine dinucleotide (NADH) and flavoproteins. Materials and Methods: ADSCS were exposed to 532 nm second harmonic generation laser light at moderate power density (0.153 W/cm²) for periods of 30, 45, 60, 180, and 300 seconds. Mitochondrial membrane potential was measured using JC1 stain and confocal laser scanning microscopy, cell proliferation rates, and cellular autofluorescence emission at 450 and 540 nm wavelengths were measured using micro plate spectrofluorometer 48 hours after irradiation. Results: Shorter (30-60 seconds) exposure times led to significantly increased proliferation, attributed to increased mitochondrial activity (P < 0.05). At longer exposures we observed a significant decrease in proliferation and autofluorescence (P < 0.05). Strong correlation was observed between proliferation rates of cells and autofluorescence intensity. Conclusion: Our results show that autofluorescence of the respiratory chain components and key autofluorescent metabolites offers a non-invasive method to quantify cellular response to laser irradiation.10 page(s

Quantitative non-invasive cell characterisation and discrimination based on multispectral autofluorescence features

Automated and unbiased methods of non-invasive cell monitoring able to deal with complex biological heterogeneity are fundamentally important for biology and medicine. Label-free cell imaging provides information about endogenous autofluorescent metabolites, enzymes and cofactors in cells. However extracting high content information from autofluorescence imaging has been hitherto impossible. Here, we quantitatively characterise cell populations in different tissue types, live or fixed, by using novel image processing and a simple multispectral upgrade of a wide-field fluorescence microscope. Our optimal discrimination approach enables statistical hypothesis testing and intuitive visualisations where previously undetectable differences become clearly apparent. Label-free classifications are validated by the analysis of Classification Determinant (CD) antigen expression. The versatility of our method is illustrated by detecting genetic mutations in cancer, non-invasive monitoring of CD90 expression, label-free tracking of stem cell differentiation, identifying stem cell subpopulations with varying functional characteristics, tissue diagnostics in diabetes, and assessing the condition of preimplantation embryos.11 page(s

Intrinsic structural variation of the complex microsatellite marker MYCL1 in Finnish and Somali populations and its relevance to gastrointestinal tumors

The structurally complex MYCL1 microsatellite marker is often used to determine microsatellite instability in colorectal cancers but the allelic variation of this marker has remained largely uncharacterized in both populations and in cancers. Our study describes the allelic distributions of MYCL1 in Finnish (n = 117) and Somali population samples (n = 61) of non-related individuals and compares this distribution with the instability pattern obtained from 61 gastrointestinal tumors