Tumor-suppressor genes in colorectal carcinomas - p53 inactivation is highly associated with allelic loss of chromosome 5q

Sixty-four colorectal carcinomas were evaluated for allelic loss of chromosomes 17p and 5q, as well as point mutation of the p53 tumor suppressor gene. Allelic loss of chromosomes 5q and 17p were found to be weakly associated, whereas point mutation of the p53 gene was found to be more strongly associated with chromosome 5q allelic loss. Carcinomas in which both alleles of p53 had been inactivated showed a strong association with allelic loss of chromosome 5q (p=2.3x10(-4)), a relationship confirmed by an association between allelic loss of chromosome 5q and immunostaining with the p53 monoclonal antibody pAb 1801 (p=9.4x10(-3)). In contrast, allelic loss of chromosome 5q was not associated with either the activation of the c-Ki-ras proto-oncogene, or with DNA aneuploidy. The association between allelic loss of chromosome 5q and the inactivation of both alleles of p53 was significantly associated with tumor dissemination (p=7.2x10(-3)). These results suggest that dissemination of colorectal neoplasia may require the coordinate inactivation of at least two suppressor genes.     

A survey of visual impairment and blindness in children attending eight schools for the blind in Myanmar: An update

Purpose:To determine the causes of visual impairment (VI) and blindness among children in schools for the blind in Myanmar; to identify the avoidable causes of VI and blindness; to provide spectacles, low-vision aids, and ophthalmic treatment where indicated; to provide an update of the 2007 survey performed and identify any major epidemiological changes.Methods:Two hundred and ninety children under 16 years of age from all eight schools for the blind in Myanmar were examined and the data entered into the World Health Organization Prevention of Blindness Examination Record for Childhood Blindness.Results:In total, 271 children (93.4%) were blind (visual acuity [VA] <3/60 in the better eye) and 15 (5.17%) had severe visual impairment (SVI = VA <6/60 to 3/60 in the better eye). Most children had whole globe as the major anatomical site of SVI or blindness (105, 36.6%). The cause was unknown in the majority of these (155, 54.0%). One hundred and twelve children had avoidable causes of blindness and SVI (39.0%). Forty children (13.9%) required an optical device and 10.1% required surgical or medical attention, with a potential for visual improvement through intervention in 3.48%.Conclusion:In all, 39.0% of children had potentially avoidable causes of SVI and blindness with cataracts and measles being the commonest causes. This follow-up survey performed after the first one completed in Myanmar in 2007 demonstrates a change in the major site of abnormality from the cornea to whole globe and a reduction in avoidable blindness but highlights the ongoing burden of measles.     

Membrane plasmalogen composition and cellular cholesterol regulation: a structure activity study

Background  

Disrupted cholesterol regulation leading to increased circulating and membrane cholesterol levels is implicated in many age-related chronic diseases such as cardiovascular disease (CVD), Alzheimer's disease (AD), and cancer. In vitro and ex vivo cellular plasmalogen deficiency models have been shown to exhibit impaired intra- and extra-cellular processing of cholesterol. Furthermore, depleted brain plasmalogens have been implicated in AD and serum plasmalogen deficiencies have been linked to AD, CVD, and cancer.     

Multiscale biomimetic topography for the alignment of neonatal and embryonic stem cell-derived heart cells

Nano- and microscale topographical cues play critical roles in the induction and maintenance of various cellular functions, including morphology, adhesion, gene regulation, and communication. Recent studies indicate that structure and function at the heart tissue level is exquisitely sensitive to mechanical cues at the nano-scale as well as at the microscale level. Although fabrication methods exist for generating topographical features for cell culture, current techniques, especially those with nanoscale resolution, are typically complex, prohibitively expensive, and not accessible to most biology laboratories. Here, we present a tunable culture platform comprised of biomimetic wrinkles that simulate the heart's complex anisotropic and multiscale architecture for facile and robust cardiac cell alignment. We demonstrate the cellular and subcellular alignment of both neonatal mouse cardiomyocytes as well as those derived from human embryonic stem cells. By mimicking the fibrillar network of the extracellular matrix, this system enables monitoring of protein localization in real time and therefore the high-resolution study of phenotypic and physiologic responses to in-vivo like topographical cues.     

What aspects of emotional functioning are impaired in schizophrenia?

Disturbances in emotional functioning are a major cause of persistent functional disability in schizophrenia. However, it is not clear what specific aspects of emotional functioning are impaired. Some studies have indicated diminished experience of positive affect in individuals with schizophrenia, while others have not. The current study assessed emotional responses by 34 individuals with schizophrenia and 35 demographically matched healthy participants to 131 images sampling a wide range of emotional arousal and valence levels. Ratings of affective response elicited by individual images were highly correlated across the groups (r's>.90), indicating similar emotional experiences at the moment of stimulus exposure. However, the data did not indicate strong relationships between ratings of the emotional impact of the images and most measures of day-to-day emotional processing. These results demonstrate that individuals with schizophrenia report "normal" emotional responses to emotional stimuli, and thus suggests that deficits in emotional functioning associated with the disorder are likely to occur further downstream, and involve the effective integration of emotion and cognition for adaptive functioning in areas such as goal-setting, motivation, and memory.     

Possible correlation between iron deposition and enhanced proliferating activity in hepatitis C virus-positive hepatocellular carcinoma in Myanmar (Burma)

Background The aim of this study was to survey the effect of deposited iron on the cell kinetics of hepatitis C virus (HCV)-positive hepatocellular carcinoma (HCC) in Myanmar (Burmese) patients. Methods Formalin-fixed and paraffin-embedded liver tissues from 34 Myanmar patients with HCC were used. To detect iron deposition, Prussian blue staining was performed. Cell proliferation and apoptosis were assessed by Ki-67 staining and by the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL) assay, respectively. HCV RNA was detected by in situ hybridization, and HCV protein, Fas and Fas ligand (FasL) were localized by immunohistochemistry. To identify the subtype of lymphocytes, CD8 was used as a surface marker. Results Iron deposition was found in 43% of the HCC cases, and was heavier in moderately differentiated HCC than in well-differentiated HCC. The Ki-67 labeling index (LI) in cancer cells was higher in Prussian blue-positive-HCC than in -negative HCC (3.8 ± 2.2 vs 1.5 ± 1.7, mean ± SD; P = 0.0067), whereas there was no significant difference between these groups in TUNEL LI. HCV protein was localized in cancer cells, and was found in 89% of the patients. In addition, Fas was expressed in HCC cells, and FasL was localized in HCC cells as well as in infiltrating CD8+ T lymphocytes. The frequency of apoptosis of HCC cells was correlated significantly with the population density of infiltrating CD8+ T lymphocytes. Conclusions Our results indicated that, in Myanmar patients with HCC, iron deposition might accelerate hepatocarcinogenesis, by promoting cancer cell proliferation, without affecting the Fas/FasL apoptotic system.     

Human neutrophil peptides induce interleukin-8 production through the P2Y6 signaling pathway

Antimicrobial human neutrophil peptides (HNPs) play a pivotal role in innate host defense against a broad spectrum of prokaryotic pathogens. In addition, HNPs modulate cellular immune responses by producing the chemokine interleukin-8 (IL-8) in myeloid and epithelial cells and by exerting chemotaxis to T cells, immature dendritic cells, and monocytes. However, the mechanisms by which HNPs modulate the immune responses in the eukaryotic cells remain unclear. We demonstrated that, as with adenosine triphosphate (ATP) and uridine diphosphate (UDP), HNP stimulation of human lung epithelial cells selectively induced IL-8 production in 10 pro- and anti-inflammatory cytokines examined. HNP-induced IL-8 release was inhibited by treatment with the nucleotide receptor antagonists suramin and reactive blue. Transfection of lung epithelial cells with antisense oligonucleotides targeting specific purinergic P2Y receptors revealed that the P2Y6 (ligand of UDP) signaling pathway plays a predominant role in mediating HNP-induced IL-8 production.