Integrin receptor signaling: the propagation of an alpha-helix model

Improper assessment and treatment of asthma attacks have been identified as causes of increased morbidity and mortality: several pneumological societies have therefore created and published guidelines for facilitating decision making and for preventing unnecessary failures of therapy. The objective of this study was to examine emergency department compliance with such guidelines in our hospital, comparing the performance of pneumologists and other specialists. We reviewed the records of 117 patients treated for acute asthma attacks in 1994 (87 women and 30 men, mean age 46 years); 37 patients were treated by pneumologists and 80 by other specialists. The two physician groups differed significantly with respect to initial assessment of severity, particularly in the recording of vital signs (p < 0.05) and in the examination of some signs such as the use of accessory musculature (38% versus 10%, for pneumologists and other specialists, respectively) or the presence of cyanosis (81% versus 55%). Other factors associated with risk of death were noted only occasionally. Peak flow meters were used with only 5 patients, all examined by pneumologists; on the other hand, arterial blood samples for gasometric measurements were taken from 97%, although only 24% met the criteria stipulated in the guidelines. Treatment evaluated against the guidelines was incorrect in 24%, with no significant differences between pneumologists and other specialists. We conclude that: 1) the emergency clinical assessment and treatment of patients presenting with acute asthma attack is inadequate for a large proportion of patients, as the recommendations of consensual guidelines are habitually ignored, and 2) although there are differences in the management of these patients by pneumologists and other emergency room specialists, the former do not generally do a better job of following the guidelines.     

EMS1 gene expression in primary breast cancer: relationship to cyclin D1 and oestrogen receptor expression and patient survival

The EMS1 and CCND1 genes at chromosome 11q13 are amplified in about 15% of primary breast cancers but appear to confer different phenotypes in ER positive and ER negative tumours. Since there are no published data on EMS1 expression in large series of breast cancers we examined the relationship of EMS1 expression with EMS1 gene copy number and expression of mRNAs for cyclin D1 and ER. In a subset of 129 patients, where matched tumour RNA and DNA was available, EMS1 mRNA overexpression was associated predominantly with gene amplification (P = 0.0061), whereas cyclin D1 mRNA overexpression was not (P = 0.3142). In a more extensive series of 351 breast cancers, there was no correlation between cyclin D1 and EMS1 expression in the EMS1 and cyclin D1 overexpressors (P = 0.3503). Although an association between EMS1 mRNA expression and ER positivity was evident (P = 0.0232), when the samples were divided into quartiles of EMS1 or cyclin D1 mRNA expression, the increase in the proportion of ER positive tumours in the ascending EMS1 mRNA quartiles was not statistically significant (P = 0.0951). In marked contrast there was a significant stepwise increase in ER positivity in ascending quartiles of cyclin D1 mRNA (P = 0.030). A potential explanation for this difference was provided by the observation that in ER positive breast cancer cells oestradiol treatment resulted in increased cyclin D1 gene expression but was without effect on EMS1. The relationship between EMS1 expression and clinical outcome was examined in a subset of 234 patients with median follow-up of 74 months. High EMS1 expression was associated with age > 50 years (P = 0.0001), postmenopausal status (P = 0.0008), lymph node negativity (P = 0.019) and an apparent trend for worse prognosis in the ER negative subgroup. These data demonstrate that overexpression of EMS1 mRNA is largely due to EMS1 gene amplification, is independent of cyclin D1 and ER expression and, in contrast to cyclin D1, is not regulated by oestrogen. Independent overexpression of these genes may confer different phenotypes and disease outcomes in breast cancer as has been inferred from recent studies of EMS1 and CCND1 gene amplification.     

Greater improvement in summer than with light treatment in winter in patients with seasonal affective disorder

OBJECTIVE: The authors sought to compare the degree of mood improvement after light treatment with mood improvement in the subsequent summer in patients with seasonal affective disorder. METHOD: By using the Seasonal Affective Disorder Version of the Hamilton Depression Rating Scale, the authors rated 15 patients with seasonal affective disorder on three occasions: during winter when the patients were depressed, during winter following 2 weeks of light therapy, and during the following summer. They compared the three conditions by using Friedman's analysis of variance and the Wilcoxon signed ranks test. RESULTS: The patients' scores on the depression scale were significantly higher after 2 weeks of light therapy in winter than during the following summer. CONCLUSIONS: Light treatment for 2 weeks in winter is only partially effective when compared to summer. Further studies will be necessary to assess if summer's light or other factors are the main contributors to this difference.     

'98 Escherichia coli SWISS-2DPAGE database update

The combination of two-dimensional polyacrylamide gel electrophoresis (2-D PAGE), computer image analysis and several protein identification techniques allowed the Escherichia coli SWISS-2DPAGE database to be established. This is part of the ExPASy molecular biology server accessible through the WWW at the URL address http://www.expasy.ch/ch2d/ch2d-top.html . Here we report recent progress in the development of the E. coli SWISS-2DPAGE database. Proteins were separated with immobilized pH gradients in the first dimension and sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the second dimension. To increase the resolution of the separation and thus the number of identified proteins, a variety of wide and narrow range immobilized pH gradients were used in the first dimension. Micropreparative gels were electroblotted onto polyvinylidene difluoride membranes and spots were visualized by amido black staining. Protein identification techniques such as amino acid composition analysis, gel comparison and microsequencing were used, as well as a recently described Edman "sequence tag" approach. Some of the above identification techniques were coupled with database searching tools. Currently 231 polypeptides are identified on the E. coli SWISS-2DPAGE map: 64 have been identified by N-terminal microsequencing, 39 by amino acid composition, and 82 by sequence tag. Of 153 proteins putatively identified by gel comparison, 65 have been confirmed. Many proteins have been identified using more than one technique. Faster progress in the E. coli proteome project will now be possible with advances in biochemical methodology and with the completion of the entire E. coli genome.     

Physiological response of Lactobacillus plantarum to salt and nonelectrolyte stress

In this report, we compared the effects on the growth of Lactobacillus plantarum of raising the medium molarity by high concentrations of KCl or NaCl and iso-osmotic concentrations of nonionic compounds. Analysis of cellular extracts for organic constituents by nuclear magnetic resonance spectroscopy showed that salt-stressed cells do not contain detectable amounts of organic osmolytes, whereas sugar-stressed cells contain sugar (and some sugar-derived) compounds. The cytoplasmic concentrations of lactose and sucrose in growing cells are always similar to the concentrations in the medium. By using the activity of the glycine betaine transport system as a measure of hyperosmotic conditions, we show that, in contrast to KCl and NaCl, high concentrations of sugars (lactose or sucrose) impose only a transient osmotic stress because external and internal sugars equilibrate after some time. Analysis of lactose (and sucrose) uptake also indicates that the corresponding transport systems are neither significantly induced nor activated directly by hyperosmotic conditions. The systems operate by facilitated diffusion and have very high apparent affinity constants for transport (>50 mM for lactose), which explains why low sugar concentrations do not protect against hyperosmotic conditions. We conclude that the more severe growth inhibition by salt stress than by equiosmolal concentrations of sugars reflects the inability of the cells to accumulate K+ (or Na+) to levels high enough to restore turgor as well as deleterious effects of the electrolytes intracellularly.     

Two color hybridization analysis using high density oligonucleotide arrays and energy transfer dyes

High density oligonucleotide arrays (DNA chips) have been used in two color mutational analysis of the 3.43 kb exon 11 of the hereditary breast and ovarian cancer gene BRCA1 . Two color analysis allows competitive hybridization between a reference standard and an unknown sample, improving the performance of the assay. Fluorescein and phycoerythrin dyes werepreviously used due to their compatibility with a single line 488 nm excitation source. Here we show that an alternative dye combination, containing the energy transfer dye system phycoerythrin*cy5 along with phycoerythrin, provides more evenly matched signal intensities and decreased spectral overlap between the two fluorophores, while maintaining compatibility with a 488 nm excitation source.     

Co-precipitation synthesis and AC conductivity of Sn0.94Zn0.04O2 nanoparticles,using impedance spectroscopy

The co-precipitation method is used for the preparation of Sn_0.94Zn_0.04O₂ nanoparticles. The formation of typical rutile-type was confirmed by X-ray diffraction studies, and it was found to be a tetragonal phase at room temperature. In addition, the complex measurement has been investigated in the temperature range 473–713 K and in the frequency range 200 Hz–5 MHz. The results have been analyzed in the complex plane formalism and suitable equivalent circuits have been proposed in different regions. The direct current conductivity shows typical Arrhenuis behavior, when observed as a function of temperature. The modulus plots can be characterized by the empirical Kohlrausch–Williams–Watts function: Φ(t) = exp [(?t/τ)^β]. The near value of activation energies obtained from the analyses of modulus and conductivity data confirms that the transport is through ion hopping mechanism in the investigated materials.     

Municipal solid waste compost application improves productivity, polyphenol content, and antioxidant capacity of Mesembryanthemum edule

Organic wastes were successfully used as soil amendment to improve agrosystems productivity. Yet, the effectiveness of this practice to enhance plant antioxidant capacities has received little attention. Here, we assess the effect of municipal solid waste (MSW) compost (at 40 t ha(-1)) on growth, polyphenol contents and antioxidant activities of Mesembryanthemum edule. MSW compost application significantly increased the soil contents of carbon, nitrogen, calcium, phosphorus and potassium. This was associated with higher nutrient (N, P, and K) uptake, which likely led to the significant improvement of the plant biomass and relative growth rate (RGR) (+93% on average) as compared to the control. In the same way, the fertilizing effect of the added organic matter significantly enhanced the antioxidant potential M. edule, assessed by radical scavenging activity, iron reducing power and β-carotene bleaching capacity. This was associated with significantly higher antioxidant contents, mainly total phenols and flavonoids. Heavy metal (Pb, Cd, Cu, and Zn) concentrations were slightly increased upon compost application, but remained lower than phytotoxic values. Overall, our results point out that short-term MSW compost application at 40 t ha(-1) is efficient in enhancing the productivity together with the antioxidant potentiality of M. edule without any adverse environmental impact.