Detection of highly pathogenic and low pathogenic avian influenza subtype H5 (Eurasian lineage) using NASBA

Nucleic acid sequence-based amplification (NASBA) is a technique that allows the rapid amplification of specific regions of nucleic acid obtained from a diverse range of sources. It is especially suitable for amplifying RNA sequences. A NASBA technique has been developed that allows the detection of avian influenza A subtype H5 from allantoic fluid harvested from inoculated chick embryos. The amplified viral RNA is detected by electrochemiluminescence. The NASBA technique described below is rapid and specific for the identification of influenza A subtype H5 viruses of the Eurasian lineage. More importantly, it can be used to distinguish highly pathogenic and low pathogenic strains of the H5 subtype.     

A protein kinase A-dependent molecular switch in synapsins regulates neurite outgrowth

Cyclic AMP (cAMP) promotes neurite outgrowth in a variety of neuronal cell lines through the activation of protein kinase A (PKA). We show here, using both Xenopus laevis embryonic neuronal culture and intact X. laevis embryos, that the nerve growth-promoting action of cAMP/PKA is mediated in part by the phosphorylation of synapsins at a single amino acid residue. Expression of a mutated form of synapsin that prevents phosphorylation at this site, or introduction of phospho-specific antibodies directed against this site, decreased basal and dibutyryl cAMP-stimulated neurite outgrowth. Expression of a mutation mimicking constitutive phosphorylation at this site increased neurite outgrowth, both under basal conditions and in the presence of a PKA inhibitor. These results provide a potential molecular approach for stimulating neuron regeneration, after injury and in neurodegenerative diseases.     

European seroepidemiology network 2: Standardisation of assays for seroepidemiology of varicella zoster virus.

BACKGROUND: The aim of the European Sero-Epidemiology Network (ESEN2) is to harmonise the serological surveillance of vaccine-preventable diseases in Europe. OBJECTIVE: To allow comparison of antibody prevalence in different countries by standardising results into common units. STUDY DESIGN: For varicella zoster virus (VZV), a reference laboratory established a panel of 148 samples, characterised by indirect enzyme-immunoassay (ELISA), indirect immunofluorescence, and complement fixation test. Fifty-seven samples were also studied by the fluorescence antibody to membrane antigen test. The geometric mean of the antibody activity (GMAA) obtained from four ELISA determinations was used to characterise each sample of the panel as positive (GMAA: >100 mIU/ml), equivocal (GMAA: 50-100 mIU/ml) or negative (GMAA: <50 mIU/ml) for antibody to VZV (anti-VZV). Thirteen laboratories, using five different ELISA tests, tested the panel. RESULTS: Agreement with the reference laboratory was above 85% in all cases, and the R(2) values obtained from regression analysis of the quantitative results were always higher than 0.87. Finally, the regression equations could be used to convert national values into a common unitage. CONCLUSION: This study confirmed that results for anti-VZV obtained by different ELISA methods can be converted into common units, enabling the comparison of the seroprevalence profiles obtained in the participant countries.     

Ionophore A23187 can mimick the changes in membrane permeability that occur during acetylcholine-stimulation of pancreatic acinar secretion

Acetylcholine (ACh) released from vagal terminals increases the permeability of the pancreatic acinar membrane to Na⁺ and Ca²⁺ ions. In this report, we compare the induced changes in intracellular Na⁺ and Ca²⁺ electrode potentials (E_Na and E_Ca) due to ACh-stimulation of acini with those observed during stimulation with the calcium ionophore, A23187, which mimicks the action of ACh on pancreatic secretion. Stimulation with ACh concentrations varying from 10^–8 to 10^–5 M and with A23187 concentrations of 10^–6 and 10^–5 M caused parallel increases in cytosolic Ca²⁺ and Na⁺ ([Ca]_i, [Na]_i). The magnitude of the increases in [Ca]_i and [Na]_i due to A23187-stimulation further indicate that when presented with a calcium challenge the acinar cells continue to regulate [Ca]_i close to physiological levels and suggest that the observed increases in ionized calcium could reflect much larger increases in complexed Ca²⁺. ACh-stimulation following removal of either extracellular Na⁺ or Ca²⁺ ions, eliminated the intracellular increases found when the removed ions is present, but did not affect the increases usually found with the other ion. The independence of the permeability changes to either the presence of Ca²⁺ or Na⁺ indicates the ACh-induced currents carried by Na⁺ and Ca²⁺ are also independent. The selective translocation of Na⁺ and Ca²⁺ during acetylcholine-stimulation in a manner analogous to the changes observed when ionophore A23187 was used as stimulus, indicates the ability of the activated acinar membrane to function as an ionophore.     

Fascin,an actin-bundling protein,modulates colonic epithelial cell invasiveness and differentiation in vitro

In epithelial tissue, cell-matrix and cell-cell adhesive interactions have important roles in the normal organization and stabilization of the cell layer. The malignant conversion of epithelial cells involves alterations in the expression and function of these adhesion systems that enable a switch to a migratory phenotype in tumor invasion and metastasis. Fascin is an actin-crosslinking protein that is found in the core actin bundles of cell-surface spikes and projections that are implicated in cell motility. We demonstrate that fascin is not detectable in normal colonic epithelium, but is dramatically up-regulated in colorectal adenocarcinoma. To test the hypothesis that fascin could participate in tumor invasive behavior, we developed a cell culture model to examine the effect of fascin expression on the adhesive interactions, invasiveness, and differentiation of colonic epithelial cells. We report marked effects on the organization of cell-surface protrusions, actin cytoskeleton, and focal adhesions in the absence of alterations in the protein levels of the major components of these structures. These effects correlate with alterations in cell movements on two-dimensional matrix, and increased invasiveness in three-dimensional matrix. The cells also show increased proliferation and decreased capacity for normal glandular differentiation in collagen gels. We propose that up-regulation of fascin, by promoting the formation of protrusive, actin-based, cell-motility structures, could be a significant component in the acquisition of invasive phenotype in colonic carcinoma.     

Functional evidence of decreased tumorigenicity associated with monochromosome transfer of chromosome 14 in esophageal cancer and the mapping of tumor-suppressive regions to 14q32

Despite the abundant evidence of high allelic loss of chromosome arm 14q in human cancers, tumor-suppressor genes mapped to this chromosome have yet to be identified. To narrow the search for candidate genes, we performed monochromosome transfer of chromosome 14 into an esophageal carcinoma cell line, SLMT-1 S1. Statistically significant suppression of the tumorigenic potential of microcell hybrids containing the transferred chromosome 14 provided functional evidence that tumor-suppressive regions of chromosome 14 are essential for esophageal cancer. Tumor segregants emerging in nude mice during the tumorigenicity assay were analyzed by detailed PCR-microsatellite typing to identify critical nonrandomly eliminated regions (CRs). A 680-kb CR mapped to 14q32.13 and an approximately 2.2-Mb CR mapped to 14q32.33 were delineated. Dual-color BAC FISH analysis of microcell hybrids and tumor segregants verified the selective loss of the 14q32.13 region. In contrast, similar transfers of an intact chromosome 11 into SLMT-1 S1 did not significantly suppress tumor formation. These functional complementation studies showing the correlation of tumorigenic potential with critical regions of chromosome 14 validated the importance of the 14q32 region in tumor suppression in esophageal cancer. The present study also paved the path for further identification of novel tumor-suppressor genes that are relevant to the molecular pathogenesis of esophageal cancer.     

Small effect of brown adipose tissue and major effect of photoperiod on body weight in hamsters (Mesocricetus auratus)

It has been suggested that brown adipose tissue plays a special role in the control of body weight. This hypothesis was investigated by measuring the body weight of female hamsters over a two month period following removal of interscapular brown adipose tissue. Two groups of animals were used, one maintained on a short day (10:14 light: dark ratio) and the other on a long day (16:8 light: dark ratio) photoperiod. Under both photoperiod conditions hamsters with interscapular brown adipose tissue removed gained somewhat more weight than their corresponding sham operated controls. Photoperiod, however, had a much larger effect on body weight. Hamsters maintained on short days increased their body weight by about 60 percent during the two months of the experiment whereas the hamsters maintained on long days increased their body weight by only about 17 percent. It was concluded that brown adipose tissue plays a small non special role in the control of body weight in the female hamster, but that the light-dark ratio is quantitatively much more important under these experimental conditions.     

Assessing Diet Quality of Indigenous Food Systems in Three Geographically Distinct Solomon Islands Sites (Melanesia,Pacific Islands)

Indigenous Solomon Islanders, like many living in Pacific Small Island Developing States (PSIDS), are currently experiencing the global syndemic—the combined threat of obesity, undernutrition, and climate change. This mixed-method study aimed to assess nutrition transitions and diet quality by comparing three geographically unique rural and urban indigenous Solomon Islands populations. Participants in rural areas sourced more energy from wild and cultivated foods; consumed a wider diversity of foods; were more likely to meet WHO recommendations of >400 g of non-starchy fruits and vegetables daily; were more physically active; and had significantly lower body fat, waist circumference, and body mass index (BMI) when compared to urban populations. Urban populations were found to have a reduced ability to self-cultivate agri-food products or collect wild foods, and therefore consumed more ultra-processed foods (classified as NOVA 4) and takeout foods, and overall had less diverse diets compared to rural populations. Clear opportunities to leverage traditional knowledge and improve the cultivation and consumption of underutilized species can assist in building more sustainable and resilient food systems while ensuring that indigenous knowledge and cultural preferences are respected.