Early signaling components in ultraviolet-B responses: distinct roles for different reactive oxygen species and nitric oxide

The nature and origin of the reactive oxygen species (ROS) involved in the early part of Ultraviolet-B (UV-B)-induced signaling pathways were investigated in Arabidopsis thaliana using a range of enzyme inhibitors and free radical scavengers. The increase in PR-1 transcript and decrease in Lhcb transcript in response to UV-B exposure was shown to be mediated through pathways involving hydrogen peroxide (H(2)O(2)) derived from superoxide (O(2)(&z.rad;-)). In contrast, the up-regulation of PDF1.2 transcript was mediated through a pathway involving O(2)(&z.rad;-) directly. The origins of the ROS were also shown to be distinct and to involve NADPH oxidase and peroxidase(s). The up-regulation of Chs by UV-B was not affected by ROS scavengers, but was reduced by inhibitors of nitric oxide synthase (NOS) or NO scavengers. Together these results suggest that UV-B exposure leads to the generation of ROS, from multiple sources, and NO, through increased NOS activity, giving rise to parallel signaling pathways mediating responses of specific genes to UV-B radiation.

The lipid peroxidation product, 4-hydroxy-2-trans-nonenal, alters the conformation of cortical synaptosomal membrane proteins

Alzheimer's disease (AD) is widely held to be a disorder associated with oxidative stress due, in part, to the membrane action of amyloid beta-peptide (A beta). A beta-associated free radicals cause lipid peroxidation, a major product of which is 4-hydroxy-2-trans-nonenal (HNE). We determined whether HNE would alter the conformation of synaptosomal membrane proteins, which might be related to the known neurotoxicity of A beta and HNE. Electron paramagnetic resonance spectroscopy, using a protein-specific spin label, MAL-6 (2,2,6,6-tetramethyl-4-maleimidopiperidin-1-oxyl), was used to probe conformational changes in gerbil cortical synaptosomal membrane proteins, and a lipid-specific stearic acid label, 5-nitroxide stearate, was used to probe for HNE-induced alterations in the fluidity of the bilayer domain of these membranes. Synaptosomal membranes, incubated with low concentrations of HNE, exhibited changes in protein conformation and bilayer order and motion (fluidity). The changes in protein conformation were found to be concentration- and time-dependent. Significant protein conformational changes were observed at physiologically relevant concentrations of 1-10 microM HNE, reminiscent of similar changes in synaptosomal membrane proteins from senile plaque- and A beta-rich AD hippocampal and inferior parietal brain regions. HNE-induced modifications in the physical state of gerbil synaptosomal membrane proteins were prevented completely by using excess glutathione ethyl ester, known to protect neurons from HNE-caused neurotoxicity. Membrane fluidity was found to increase at higher concentrations of HNE (50 microM). The results obtained are discussed with relevance to the hypothesis of A beta-induced free radical-mediated lipid peroxidation, leading to subsequent HNE-induced alterations in the structure and function of key membrane proteins with consequent neurotoxicity in AD brain.

An integrated multi-omics analysis identifies prognostic molecular subtypes of non-muscle-invasive bladder cancer

The molecular landscape in non-muscle-invasive bladder cancer (NMIBC) is characterized by large biological heterogeneity with variable clinical outcomes. Here, we perform an integrative multi-omics analysis of patients diagnosed with NMIBC (n = 834). Transcriptomic analysis identifies four classes (1, 2a, 2b and 3) reflecting tumor biology and disease aggressiveness. Both transcriptome-based subtyping and the level of chromosomal instability provide independent prognostic value beyond established prognostic clinicopathological parameters. High chromosomal instability, p53-pathway disruption and APOBEC-related mutations are significantly associated with transcriptomic class 2a and poor outcome. RNA-derived immune cell infiltration is associated with chromosomally unstable tumors and enriched in class 2b. Spatial proteomics analysis confirms the higher infiltration of class 2b tumors and demonstrates an association between higher immune cell infiltration and lower recurrence rates. Finally, the independent prognostic value of the transcriptomic classes is documented in 1228 validation samples using a single sample classification tool. The classifier provides a framework for biomarker discovery and for optimizing treatment and surveillance in next-generation clinical trials.

Vaccination against infectious bronchitis virus: A continuous challenge

Infectious bronchitis virus (IBV) is a significant respiratory pathogen of commercial poultry that causes millions of dollars in lost revenue worldwide each year. Even though the poultry industry extensively vaccinates against IBV, emergence of new serotypes and variants continually occur, making control of the disease difficult. Current mass application strategies for IBV vaccines are inefficient and frequently result in vaccination failures. Novel vaccine technology development has been slow, and is hindered by the constraints of large-scale poultry production. Further complicating the situation is the lack of knowledge of IBV protein and host cell interactions, making targeted vaccine intervention strategies near impossible. Taken together, it is easy to see why this disease remains significant in poultry production. This review outlines the current situation as it relates to IBV control, including vaccination, vaccines, and development of immunity, and recent developments in vaccine technology that may provide better protection in the future.

Gene expression profiling of primary breast carcinomas using arrays of candidate genes

Breast cancer is characterized by an important histoclinical heterogeneity that currently hampers the selection of the most appropriate treatment for each case. This problem could be solved by the identification of new parameters that better predict the natural history of the disease and its sensitivity to treatment. A large-scale molecular characterization of breast cancer could help in this context. Using cDNA arrays, we studied the quantitative mRNA expression levels of 176 candidate genes in 34 primary breast carcinomas along three directions: comparison of tumor samples, correlations of molecular data with conventional histoclinical prognostic features and gene correlations. The study evidenced extensive heterogeneity of breast tumors at the transcriptional level. A hierarchical clustering algorithm identified two molecularly distinct subgroups of tumors characterized by a different clinical outcome after chemotherapy. This outcome could not have been predicted by the commonly used histoclinical parameters. No correlation was found with the age of patients, tumor size, histological type and grade. However, expression of genes was differential in tumors with lymph node metastasis and according to the estrogen receptor status; ERBB2 expression was strongly correlated with the lymph node status (P < 0.0001) and that of GATA3 with the presence of estrogen receptors (P < 0.001). Thus, our results identified new ways to group tumors according to outcome and new potential targets of carcinogenesis. They show that the systematic use of cDNA array testing holds great promise to improve the classification of breast cancer in terms of prognosis and chemosensitivity and to provide new potential therapeutic targets.

Peroxynitrite-induced alterations in synaptosomal membrane proteins: insight into oxidative stress in Alzheimer's disease

Peroxynitrite (ONOO ) is a highly reactive, oxidizing anion with a half-life of <1 s that is formed by reaction of superoxide radical anion with nitric oxide. Several reports of ONOO--induced oxidation of lipids, proteins, DNA, sulfhydryls, and inactivation of key enzymes have appeared. ONOO- has also been implicated as playing a role in the pathology of several neurodegenerative disorders, such as Alzheimer's disease (AD) and amyotrophic lateral sclerosis, among others. Continuing our laboratory's interest in free radical oxidative stress in brain cells in AD, the present study was designed to investigate the damage to brain neocortical synaptosomal membrane proteins and the oxidation-sensitive enzyme glutamine synthetase (GS) caused by exposure to ONOO-. These synaptosomal proteins and GS have previously been shown by us and others to have been oxidatively damaged in AD brain and also following treatment of synaptosomes with amyloid beta-peptide. The results of the current study showed that exposure to physiological levels of ONOO- induced significant protein conformational changes, demonstrated using electron paramagnetic resonance in conjunction with a protein-specific spin label, and caused oxidation of proteins, measured by the increase in protein carbonyls. ONOO- also caused inactivation of GS and led to neuronal cell death examined in a hippocampal cell culture system. All these detrimental effects of ONOO- were successfully attenuated by the thiol-containing antioxidant tripeptide glutathione. This research shows that ONOO- can oxidatively modify both membranous and cytosolic proteins, affecting both their physical and chemical nature. These findings are discussed with reference to the potential involvement of ONOO- in AD neurodegeneration.

The strong ion gap does not have prognostic value in critically ill patients in a mixed medical/surgical adult ICU

OBJECTIVE

To examine whether the strong ion gap (SIG) or standard base excess corrected for abnormalities of serum chloride and albumin (BE(UA)) can predict outcome and to compare the prognostic abilities of these variables with standard base excess (SBE), anion gap (AG), pH, and lactate, the more traditional markers of acid-base disturbance.

DESIGN

Prospective, observational study.

SETTING

University teaching hospital, general adult ICU.

PATIENTS

One hundred consecutive patients on admission to the ICU.

MEASUREMENTS AND RESULTS

The anion gap (AG) was calculated and corrected for abnormal serum albumin (AG(corrected)). Serum lactate was measured and SBE, BE(UA), SIG, and APACHE II scores calculated for each patient. 28-day survival was recorded. There was a significant difference between the mean APACHE II (P < 0.001), SBE (P < 0.001), lactate (P = 0.008), AG (P = 0.007), pH (P < 0.001), and BE(UA) (P = 0.009) of survivors and non-survivors. There was no significant difference between the mean SIG (P = 0.088), SIDeff (P = 0.025), and SID app (P = 0.254) between survivors and non-survivors. The pH and SBE demonstrated the best ability of the acid-base variables to predict outcome (AUROC curves 0.72 and 0.71, respectively). Neither of these were as good as the APACHE II score (AUROC 0.76)

CONCLUSION

Traditional indices of SBE, BE(UA,) lactate, pH, AG, and APACHE II all discriminated well between survivors and non-survivors. In this group of patients the SIG, SIDeff, and SIGapp appear to offer no advantage in prediction of outcome and their use as prognostic markers can therefore not be advocated.

Differential expression assay of chromosome arm 8p genes identifies Frizzled-related (FRP1/FRZB) and Fibroblast Growth Factor Receptor 1 (FGFR1) as candidate breast cancer genes

Deletions and amplifications are frequent alterations of the short arm of chromosome 8 associated with various types of cancers, including breast cancers. This indicates the likely presence of tumor suppressor genes and oncogenes. In the present study, we have used the expressed sequence tag (EST) map of 8p11-21 to assemble a set of available cDNAs representing genes from this region. DNA arrays were prepared for expression analysis and search for genes potentially involved in breast cancer. Underexpresion in tumoral breast cells (versus normal breast) was observed for 15 transcripts. Among these, the Frizzled-related gene FRP1/FRZB, was turned off in 78% of breast carcinomas, suggesting that the lack of its product may be associated with malignant transformation. Overexpression in tumoral breast cells was observed for 13 genes. The FGFR1 gene, that encodes a tyrosine kinase receptor for members of the fibroblast growth factor family, was identified as a good candidate for one amplification unit. Taken together, our results demonstrate that such a strategy can rapidly identify genes with an altered pattern of expression and provide candidate genes for malignancies.

Blazar spectral variability as explained by a twisted inhomogeneous jet

Blazars are active galactic nuclei, which are powerful sources of radiation whose central engine is located in the core of the host galaxy. Blazar emission is dominated by non-thermal radiation from a jet that moves relativistically towards us, and therefore undergoes Doppler beaming. This beaming causes flux enhancement and contraction of the variability timescales, so that most blazars appear as luminous sources characterized by noticeable and fast changes in brightness at all frequencies. The mechanism that produces this unpredictable variability is under debate, but proposed mechanisms include injection, acceleration and cooling of particles, with possible intervention of shock waves or turbulence. Changes in the viewing angle of the observed emitting knots or jet regions have also been suggested as an explanation of flaring events and can also explain specific properties of blazar emission, such as intra-day variability, quasi-periodicity and the delay of radio flux variations relative to optical changes. Such a geometric interpretation, however, is not universally accepted because alternative explanations based on changes in physical conditions-such as the size and speed of the emitting zone, the magnetic field, the number of emitting particles and their energy distribution-can explain snapshots of the spectral behaviour of blazars in many cases. Here we report the results of optical-to-radio-wavelength monitoring of the blazar CTA 102 and show that the observed long-term trends of the flux and spectral variability are best explained by an inhomogeneous, curved jet that undergoes changes in orientation over time. We propose that magnetohydrodynamic instabilities or rotation of the twisted jet cause different jet regions to change their orientation and hence their relative Doppler factors. In particular, the extreme optical outburst of 2016-2017 (brightness increase of six magnitudes) occurred when the corresponding emitting region had a small viewing angle. The agreement between observations and theoretical predictions can be seen as further validation of the relativistic beaming theory.

Views of what's wrong: diagnosis and patients' concepts of illness

A group of women were interviewed about their construction of their illness experiences before they saw a physician and subsequently over a period of several months following consultation. It was found that the physician's input was one of many components of their post-consultation understanding of their illnesses. The women built up their understandings in an interactive process, drawing significantly on their prior histories, ongoing experiences and social worlds. They continually tried out, adjusted and reworked the construction of their illnesses to adapt them to the exigencies of everyday life. We conclude that illness explanations are dynamic entities whose adequacy is determined by their usefulness within the extra-medical social environment.

The free radical antioxidant vitamin E protects cortical synaptosomal membranes from amyloid beta-peptide(25-35) toxicity but not from hydroxynonenal toxicity: relevance to the free radical hypothesis of Alzheimer's disease

Amyloid beta-peptide (Abeta) is a key factor in the neurotoxicity of Alzheimer's disease (AD). Recent research has shown that Abeta-mediated neurotoxicity involves free radicals and that Abeta peptides can initiate multiple membrane alterations, including protein oxidation and lipid peroxidation, eventually leading to neuronal cell death. Research also has emphasized the role of 4-hydroxynonenal (HNE), a downstream product of lipid peroxidation, in being able to mimic some of the effects of Abeta peptides. In the current investigation, electron paramagnetic resonance (EPR) studies of spin labeled cortical synaptosomal membrane proteins has been employed to study conformational changes in proteins, spectrophotometric methods have been used to measure protein carbonyl content, and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay for mitochondrial function has been used to study the effect of vitamin E on samples that were treated with Abeta or HNE. The free radical dependence of beta-amyloid-associated toxicity was confirmed by the ability of the free radical scavenger vitamin E to prevent the toxic effects of Abeta. In contrast, HNE was still toxic in the presence of vitamin E. These results support our Abeta-associated free radical model for neurotoxicity in AD brain and are discussed with reference to potential therapeutic strategies for AD.

Compliance and the patient's perspective: controlling symptoms in everyday life

Non-compliance with medical advice is poorly understood. Most of the existing literature considers the problem only from the doctor's point of view. We undertook a diachronic, qualitative study of the illness experiences of 19 women to try to understand non-compliance from the patient's perspective. Three-fourths of our study group had ceased to follow their doctor's recommendations by four months post-diagnosis. Their non-compliance could not be explained by the fact that the women held understandings of their illnesses which were incongruent with their physician's; nor were they unable to understand the diagnosis they received. A consideration of the roles that their diagnosis and treatments played in their daily lives proved more useful in explaining their failure to follow physicians' recommendations. Patients' use of treatments reflected their desire to control symptoms within the constraints of their daily routines.

Cosmopolitical obstetrics: some insights from the training of traditional midwives

In most countries of the third world, strategies for development in the health sector include efforts to upgrade the skills of village level health care workers, including traditional birth attendants (TBAs). In spite of several decades of experience, training programs for TBAs have not been particularly successful. Drawing on data from several years of ethnographic fieldwork with Maya midwives in Yucatan and on participation in government-sponsored training courses for indigenous midwives, this paper examines some of the reasons underlying this failure. Paramount among these are differences in world view and the misapplication of didactic modes of teaching in situations where learning in the apprenticeship mode is more appropriate and culturally customary.

Lower cognitive performance of older football players possessing apolipoprotein E epsilon4

OBJECTIVE

To determine whether the cognitive status of professional football players varies as a function of age and apolipoprotein E (APOE) genotype.

METHODS

Fifty-three active players underwent APOE and neuropsychological assessments. Players were grouped according to age (proxy indicator of high/low exposure to contact) and the presence/absence of at least one copy of the epsilon4 allele. Outcome measures were overall cognitive performance and scores in cognitive domains.

RESULTS

As a group, older players possessing APOE epsilon4 exhibited significantly lower cognitive test scores than did all other players studied, including non-epsilon4-possessing players and younger epsilon4-carriers. Measures of general cognitive functioning, information-processing speed and accuracy, and attention were related to poorer performance among the epsilon4-carrying players. In an analysis of variance model, the interaction between APOE genotype and age was significant (P = 0.004). As determined using linear regression, age accounted for 34% of the variance in the memory index among APOE epsilon4-possessing players but did not contribute significantly to variance among the non-epsilon4-possessing players. Older APOE epsilon4-carriers were significantly overrepresented among players whose scores indicated possible cognitive impairment, with the criterion of performing two or more standard deviations below the general normal values in a summary index of general cognitive functioning.

CONCLUSION

Older professional football players who possessed the APOE epsilon4 allele scored lower on cognitive tests than did players without this allele or less experienced players of any genotype. The cognitive status of professional athletes with repeated exposure to head trauma may therefore be influenced by age, inherited factors such as APOE genotype, and cumulative exposure to contact.

Thermally injured patients are at significant risk for thromboembolic complications

BACKGROUND

The incidence of thromboembolic complications such as deep vein thrombosis (DVT) and pulmonary embolism (PE) in thermally injured patients is considered sufficiently uncommon that routine prophylactic measures are not warranted. Nevertheless, the incidence of DVT/PE may be increasing.

METHODS

The records of 1,300 patients admitted to our unit from January 1990 to June 1995 were reviewed.

RESULTS

Twenty-three patients developed a clinically significant DVT, eight patients developed a PE, and two patients developed both a DVT and a PE, for an overall DVT/PE incidence of 2.9%. Four of 10 PEs were felt to be fatal. The DVT/PE patients were older (mean age, 42.6 vs. 28.7; p < 0.001) and had larger burns (37% vs. 18%, p < 0.001) than patients without evidence of DVT/PE. Body weight appeared to also influence DVT/PE rates, with obese patients (>30% over ideal body weight) having a higher incidence than patients with low or normal body weight (7.2 vs. 2.7%, p < 0.015). Age and total body surface area (TBSA) burn had a synergistic effect on DVT/PE risk, with the sum of age and TBSA burn exerting the strongest independent effect when discriminant function analysis was performed (p < 0.001).

CONCLUSION

One can identify a population at increased risk of DVT/PE on the basis of the sum of age and TBSA burn, but prospective screening trials that assess all risk factors for DVT/PE should be performed before routine prophylaxis is used in thermally injured patients.

Metabolite profiling and transcriptomic analyses reveal an essential role of UVR8-mediated signal transduction pathway in regulating flavonoid biosynthesis in tea plants (Camellia sinensis) in response to shading

BACKGROUND

Tea is the most popular nonalcoholic beverage worldwide for its pleasant characteristics and healthful properties. Catechins, theanine and caffeine are the major natural products in tea buds and leaves that determine tea qualities such as infusion colors, tastes and fragrances, as well as their health benefits. Shading is a traditional and effective practice to modify natural product accumulation and to enhance the tea quality in tea plantation. However, the mechanism underlying the shading effects is not fully understood. This study aims to explore the regulation of flavonoid biosynthesis in Camellia sinensis under shading by using both metabolomic and transcriptional analyses.

RESULTS

While shading enhanced chlorophyll accumulation, major catechins, including C, EC, GC and EGC, decreased significantly in tea buds throughout the whole shading period. The reduction of catechins and flavonols were consistent with the simultaneous down-regulation of biosynthetic genes and TFs associated with flavonoid biosynthesis. Of 16 genes involved in the flavonoid biosynthetic pathway, F3'H and FLS significantly decreased throughout shading while the others (PAL, CHSs, DFR, ANS, ANR and LAR, etc.) temporally decreased in early or late shading stages. Gene co-expression cluster analysis suggested that a number of photoreceptors and potential genes involved in UV-B signal transductions (UVR8_L, HY5, COP1 and RUP1/2) showed decreasing expression patterns consistent with structural genes (F3'H, FLS, ANS, ANR, LAR, DFR and CHSs) and potential TFs (MYB4, MYB12, MYB14 and MYB111) involved in flavonoid biosynthesis, when compared with genes in the UV-A/blue and red/far-red light signal transductions. The KEGG enrichment and matrix correlation analyses also attributed the regulation of catechin biosynthesis to the UVR8-mediated signal transduction pathway. Further UV-B treatment in the controlled environment confirmed UV-B induction on flavonols and EGCG accumulation in tea leaves.

CONCLUSIONS

We proposed that catechin biosynthesis in C. sinensis leaves is predominantly regulated by UV through the UVR8-mediated signal transduction pathway to MYB12/MYB4 downstream effectors, to modulate flavonoid accumulation. Our study provides new insights into our understanding of regulatory mechanisms for shading-enhanced tea quality.

Molecular mapping of the human T cell receptor gamma (TRG) genes and linkage of the variable and constant regions

In the human T cell receptor gamma (TRG) locus, fourteen variable (TRGV) genes belonging to four subgroups have been identified upstream of two constant region (TRGC) genes. Three joining segments, JP1, JP and J1, have been localized upstream of TRGC1, and two others, JP2 and J2, upstream of TRGC2. In this report, we demonstrate that a unique Xho I fragment of 120 kilobases (kb) contains the fourteen TRGV genes and that the hybridization of that fragment in pulsed-field gel electrophoresis (PFGE) allows linkage of the variable region to the constant region locus. We also show that the variable and the constant regions are remarkably close to each other since the distance between V11, the most 3' V gamma gene, and JP1, the most 5' J gamma segment, is only 16 kb. With its 14 V gamma genes, spanning 100 kb, the two C gamma genes and 5 joining segments covering less than 40 kb and only 16 kb separating the most 3' V gene from the most 5' J segment, the human TRG locus spans 160 kb of genomic DNA and represents a particularly condensed locus compared to the other rearranging gene loci.

Adriamycin-induced changes of creatine kinase activity in vivo and in cardiomyocyte culture

Adriamycin (ADM) is an anthracycline anti-neoplastic agent, whose clinical effectiveness is limited by severe side effects, including cardiotoxicity. The toxic effects of ADM are likely to be the consequence of the generation of free radicals. This study demonstrates that ADM induces significant changes in the activity of the oxidative sensitive enzyme creatine kinase (CK) in the heart in vivo and in a cardiomyocyte culture model. The changes observed are likely to reflect the ability of ADM to damage the plasma membrane of cardiac cells and to induce the direct inactivation of CK. The role for ADM-derived free radicals is one of the possible mechanisms for the CK inactivation observed during the ADM treatment.

Expression scanning of an array of growth control genes in human tumor cell lines

Analysis of gene expression on a medium- or large-scale is an increasingly recognized method for functional and clinical investigations based on the now extensive catalog of known or partially sequenced genes. The accessibility of this approach can be enhanced by using readily available technology (macroarrays on Nylon, radioactive detection) and the IMAGE resource to assemble sets of targets. We have set up such a medium-scale, flexible system and validated it by the study of quantitative expression levels for 120 genes in six cell lines, including three mammary carcinoma cell lines. A number of important parameters are identified as necessary for the assembly of a valid set and the obtention of good-quality quantitative data. The extensive data assembled in this survey identified potential targets of carcinogenesis, for example the CRABP2 and GATA3 transcription factor genes. We also demonstrate the feasibility of this procedure for relatively small tumor samples, without recourse to probe amplification methods.