A study of serum malondialdehyde and interleukin-6 levels in young women with dysmenorrhea in Taiwan

The purpose of this study was to examine whether the symptoms of dysmenorrhea in young women were related to serum malondialdehyde (MDA) and interleukin-6 (IL-6) levels. Ninety-four non-smoking and non-drinking female subjects without serious disease from a nursing college in Taiwan were divided into two groups. Group 1 consisted of 51 subjects without dysmenorrheal, and Group 2 of 43 subjects with dysmenorrheal symptom. All subjects were provided informed consent. Results showed that the serum levels of MDA and of IL-6 were significantly different between the two groups (P < 0.05) and (P < 0.005), respectively. We conclude that the pathological mechanism of dysmenorrhea is mediated by oxidative stress caused by the action of cytokine.     

Learning rules for optimal selection in a varying environment: mate choice revisited

The quality of a chosen partner can be one of the most significantfactors affecting an animal's long-term reproductive success.We investigate optimal mate choice rules in an environment wherethere is both local variation in the quality of potential mateswithin each local mating pool and spatial (or temporal) variationin the average quality of the pools themselves. In such a situation,a robust rule that works well across a variety of environmentswill confer a significant reproductive advantage. We formulatea full Bayesian model for updating information in such a varyingenvironment and derive the form of the rule that maximizes expectedreward in a spatially varying environment. We compare the theoreticalperformance of our optimal learning rule against both fixedthreshold rules and simpler near-optimal learning rules andshow that learning is most advantageous when both the localand environmental variances are large. We consider how optimalsimple learning rules might evolve and compare their evolutionwith that of fixed threshold rules using genetic algorithmsas minimal models of the relevant genetics. Our analysis pointsup the variety of ways in which a near-optimal rule can be expressed.Finally, we describe how our results extend to the case of temporallyvarying environments.     

Pair-level approximations to the spatio-temporal dynamics of epidemics on asymmetric contact networks

The process of infection during an epidemic can be envisaged as being transmitted via a network of routes represented by a contact network. Most differential equation models of epidemics are mean-field models. These contain none of the underlying spatial structure of the contact network. By extending the mean-field models to pair-level, some of the spatial structure can be contained in the model. Some networks of transmission such as river or transportation networks are clearly asymmetric, whereas others such as airborne infection can be regarded as symmetric. Pair-level models have been developed to describe symmetric contact networks. Here we report on work to develop a pair-level model that is also applicable to asymmetric contact networks. The procedure for closing the model at the level of pairs is discussed in detail. The model is compared against stochastic simulations of epidemics on asymmetric contact networks and against the predictions of the symmetric model on the same networks. DEFRA funded project FC1153     

Mode Transitions in a Model Reaction–Diffusion System Driven by Domain Growth and Noise

Pattern formation in many biological systems takes place during growth of the underlying domain. We study a specific example of a reaction-diffusion (Turing) model in which peak splitting, driven by domain growth, generates a sequence of patterns. We have previously shown that the pattern sequences which are presented when the domain growth rate is sufficiently rapid exhibit a mode-doubling phenomenon. Such pattern sequences afford reliable selection of certain final patterns, thus addressing the robustness problem inherent of the Turing mechanism. At slower domain growth rates this regular mode doubling breaks down in the presence of small perturbations to the dynamics. In this paper we examine the breaking down of the mode doubling sequence and consider the implications of this behaviour in increasing the range of reliably selectable final patterns.     

1,4-Benzoquinone-based electrophoretic assay for glucose oxidase

The communication demonstrates feasibility of an enzyme microassay for glucose oxidase with 1,4-benzoquinone as an acceptor of electrons. The protocol uses the plug-plug mode of electrophoretically mediated microanalysis, with nanolitre injected volumes of enzyme and reactant solutions. The reactant and product, 1,4-benzoquinone and hydroquinone, are separated during the assay by differential binding to sulfated-beta-cyclodextrin used as additive to the phosphate buffer (pH 7) and monitored at selected wavelengths in their UV spectra. The assay covers glucose oxidase concentration from 0.01 to 0.1mgml(-1). Due to the strong UV absorbance of the both reactant and product, there is no need for use of a second enzyme (peroxidase) in the present assay.     

Immunomarkers in gynecologic cytology: the search for the ideal 'biomolecular Papanicolaou test'

Harnessing the knowledge we have gained on the cell cycle disruption caused by human papillomaviruses (HPV) will likely lead to improved screening modalities for cervical cancer and its precursors. An easily applied biomarker that has high specificity and sensitivity would represent an attractive alternative or complement to cytology and HPV testing. To date, a number of promising markers have been investigated. These include p16(INK4A), MIB-1, BD-ProEx C, and L1. Newer possibilities involve a variety of gene products associated with aberrations of chromosome 3q, such as telomerase, p63, and PIK3CA, as well the combination of biomarkers such as p16(INK4A) and MIB-1 in the same assay. Although none of them has yet been incorporated into screening algorithms or found its way into routine practice, their performance characteristics remain a focus of current investigations. This review summarizes what we know and where we hope to go in translating basic pathobiology into clinical practice.     

Identification of a new steroid degrading bacterial strain H5 from the Baltic Sea and isolation of two estradiol inducible genes

The presence of steroid hormones in the aquatic environment is potentially threatening the population dynamics of all kinds of sea animals and public health. Environmental estrogens in water have been reported to be associated with abnormal sexual development and abnormal feminizing responses in some animals. New approaches for the bioremediation of steroid hormones from the environment are therefore urgently sought. We have previously isolated a steroid degrading bacterial strain (H5) from the Baltic Sea, at Kiel, Germany. In the present investigation, 16S rRNA analysis showed that marine strain H5 belongs to the genus Vibrio, family Vibrionaceae and class Gamma-Proteobacteria. To enable identification of steroid inducible genes from bacterial strain H5, a library was constructed of H5 chromosomal DNA fragments cloned into a fluorescent reporter (pKEGFP-2). A reporter plasmid pK3α-4.6-EGFP3 containing the estrogen-inducible gene 3α-hydroxysteroid dehydrogenase/carbonyl reductase (3α-HSD/CR) from Comamonas testosteroni (C. testosteroni) was created as a positive control. Steroid induction could be detected by a microplate fluorescence reader, when the plasmids were transformed into Escherichia coli (E. coli) HB101 cells. With our meta-genomic pKEGFP-2 approach, we identified two estradiol-inducible genes from marine strain H5, which are obviously involved in steroid degradation. Sequencing of the pKEGFP-2 inserts and data base research at NCBI revealed that one gene corresponds to 3-ketosteroid-delta-1-dehydrogenase from several Mycobacterium strains, while the other showed high similarity to carboxylesterase in Sebadella termitidis and Brachyspira murdochii. Both 3-ketosteroid-delta-1-dehydrogenase and carboxylesterase are one of the first enzymes in steroid degradation. In addition, we identified a strain H5 specific DNA sequence of 480bp which allows sensitive PCR detection and quantification of strain H5 bacteria in "unknown" seawater samples. Currently, the exact characterization and systematic classification of the marine steroid degrading bacterial strain H5 is envisaged, which might be used for the bioremediation of steroid contaminations in seawater. Article from a special issue on steroids and microorganisms.     

Physiological ecology of desert biocrust moss following 10 years exposure to elevated CO₂: evidence for enhanced photosynthetic thermotolerance

In arid regions, biomes particularly responsive to climate change, mosses play an important biogeochemical role as key components of biocrusts. Using the biocrust moss Syntrichia caninervis collected from the Nevada Desert Free Air CO₂ Enrichment Facility, we examined the physiological effects of 10 years of exposure to elevated CO₂, and the effect of high temperature events on the photosynthetic performance of moss grown in CO₂‐enriched air. Moss exposed to elevated CO₂ exhibited a 46% decrease in chlorophyll, a 20% increase in carbon and no difference in either nitrogen content or photosynthetic performance. However, when subjected to high temperatures (35–40°C), mosses from the elevated CO₂ environment showed higher photosynthetic performance and photosystem II (PSII) efficiency compared to those grown in ambient conditions, potentially reflective of a shift in nitrogen allocation to components that offer a higher resistance of PSII to heat stress. This result suggests that mosses may respond to climate change in markedly different ways than vascular plants, and observed CO₂‐induced photosynthetic thermotolerance in S. caninervis will likely have consequences for future desert biogeochemistry.     

Turning up the heat: immune brinksmanship in the acute-phase response

The acutephase response (APR) is a systemic response to severe trauma, infection, and cancer, although many of the numerous cytokine-mediated components of the APR are incompletely understood. Some of these components, such as fever, reduced availability of iron and zinc, and nutritional restriction due to anorexia, appear to be stressors capable of causing harm to both the pathogen and the host. We review how the host benefits from differences in susceptibility to stress between pathogens and the host. Pathogens, infected host cells, and neoplastic cells are generally more stressed or vulnerable to additional stress than the host because: (a) targeted local inflammation works in synergy with APR stressors; (b) proliferation/growth increases vulnerability to stress; (c) altered pathogen physiology results in pathogen stress or vulnerability; and (d) protective heat shock responses are partially abrogated in pathogens since their responses are utilized by the host to enhance immune responses. Therefore, the host utilizes a coordinated system of endogenous stressors to provide additional levels of defense against pathogens. This model of immune brinksmanship can explain the evolutionary basis for the mutually stressful components of the APR.