Gene expression responses to acute and chronic heat stress in the common reef-building coral Pocillopora verrucosa

Global climate change is impacting coral reefs worldwide, with approximately 19% of reefs being permanently degraded, 15% showing symptoms of imminent collapse, and 20% at risk of becoming critically affected in the next few decades. This alarming level of reef degradation is mainly due to an increase in frequency and intensity of natural and anthropogenic disturbances. Recent evidence has called into question whether corals have the capacity to acclimatize or adapt to climate changes and some groups of corals showed inherent physiological tolerance to environmental stressors. The aim of the present study was to evaluate mRNA expression patterns underlying differences in thermal tolerance in specimen of the common reef-building coral Pocillopora verrucosa collected at different locations in Bangka Island waters (North Sulawesi, Indonesia). Part of the experimental work was carried out at the CoralEye Reef Research Outpost (Bangka Island). This includes sampling of corals at selected sites and at different depths (3 and 12 m) as well as their experimental exposure to an increased water temperature under controlled conditions for 3 and 7 days. Levels of mRNAs encoding ATP synthase (ATPs) NADH dehydrogenase (NDH) and a 70kDa Heat Shock Protein (HSP70) were evaluated by quantitative real time PCR. Transcriptional profiles evaluated under field conditions suggested an adaptation to peculiar local environmental conditions in corals collected at different sites and at the low depth. Nevertheless, high–depth collected corals showed a less pronounced site-to-site separation suggesting more homogenous environmental conditions. Exposure to an elevated temperature under controlled conditions pointed out that corals adapted to the high depth are more sensitive to the effects of thermal stress, so that reacted to thermal challenge by significantly over-expressing the selected gene products. Being continuously exposed to fluctuating environmental conditions, low-depth adapted corals are more resilient to the stress stimulus, and indeed showed unaffected or down-regulated mRNA expression profiles. Overall these results highlight that transcriptional profiles of selected genes involved in cellular stress response are modulated by natural seasonal temperature changes in P. verrucosa. Moreover, specimens living in more variable habitats (low-depth) exhibit higher basal HSP70 mRNA levels, possibly enhancing physiological tolerance to environmental stressors.

Effects of acute temperature increase on performance and survival of Caribbean echinoids

Climate change is occurring at a faster rate than in the past, with an expected increase of mean sea surface temperatures up to 4.8°C by the end of this century. The actual capabilities of marine invertebrates to adapt to these rapid changes has still to be understood. Adult echinoids play a crucial role in the tropical ecosystems where they live. Despite their role, few studies about the effect of temperature increase on their viability have been reported in literature. This thesis work reports a first systematic study on several Caribbean echinoids about their tolerance to temperature rise in the context of global warming. The research - carried out at the Bocas del Toro Station of the Smithsonian Tropical Research Institute, in Panama - focalized on the 6 sea urchins Lytechinus variegatus, L. williamsi, Echinometra lucunter, E. viridis, Tripneustes ventricosus and Eucidaris tribuloides, and the 2 sand dollars Clypeaster rosaceus and C. subdepressus. Mortality and neuromuscular well-being indicators - such as righting response, covering behaviour, adhesion to the substrate, spine and tube feet movements - have been analysed in the temperature range 28-38°C. The righting time RT (i.e., the time necessary for the animal to right itself completely after inversion) measured in the 6 sea urchin species, demonstrated a clearly dependence on the water temperature. The experiments allowed to determine the “thermal safety margin” (TSM) of each species. Echinometra lucunter and E. viridis resulted the most tolerant species to high temperatures with a TSM of 5.5°C, while T. ventricosus was the most vulnerable with a TSM of only 3°C. The study assessed that all the species already live at temperatures close to their upper thermal limit. Their TSMs are comparable to the predicted temperature increase by 2100. In absence of acclimatization to such temperature change, these species could experience severe die-offs, with important consequences for tropical marine ecosystems.

Effect of Acute Psychological Stress on Prefrontal GABA Concentration Determined by Proton Magnetic Resonance Spectroscopy

Objective Impaired function of the central gamma-aminobutyric acid (GABA) system, which provides the brain’s major inhibitory pathways, is thought to play an important role in the pathophysiology of anxiety disorders. The effect of acute psychological stress on the human GABA-ergic system is still unknown, however. The purpose of this study was to determine the effect of acute stress on prefrontal GABA levels. Method A recently developed noninvasive magnetic resonance spectroscopy method was used to measure changes in the GABA concentration of the prefrontal cortex in 10 healthy human subjects during a threat-of-shock condition and during a safe condition (two sessions on different days). The main outcome measure was the mean GABA concentration within a 3×3×2-cm3 voxel selected from the medial prefrontal cortex. Results Prefrontal GABA decreased by approximately 18% in the threat-of-shock condition relative to the safe condition. This reduction was specific to GABA, since the concentrations of N-acetyl-aspartate, choline-containing compounds, and glutamate/glutamine levels obtained in the same spectra did not change significantly. Conclusions This result appeared compatible with evidence from preclinical studies in rodents, which showed rapid presynaptic down-regulation of GABA-ergic neurotransmission in response to acute psychological stress. The molecular mechanism and functional significance of this reduced inhibitory effect of acute psychological stress in relation to impaired GABA-ergic function in anxiety disorders merit further investigation.

Perceived functional ability assessed with the spinal function sort: is it valid for European rehabilitation settings in patients with non-specific non-acute low back pain?

The aim of this study involving 170 patients suffering from non-specific low back pain was to test the validity of the spinal function sort (SFS) in a European rehabilitation setting. The SFS, a picture-based questionnaire, assesses perceived functional ability of work tasks involving the spine. All measurements were taken by a blinded research assistant; work status was assessed with questionnaires. Our study demonstrated a high internal consistency shown by a Cronbach's alpha of 0.98, reasonable evidence for unidimensionality, spearman correlations of >0.6 with work activities, and discriminating power for work status at 3 and 12 months by ROC curve analysis (area under curve = 0.760 (95% CI 0.689-0.822), respectively, 0.801 (95% CI 0.731-0.859). The standardised response mean within the two treatment groups was 0.18 and -0.31. As a result, we conclude that the perceived functional ability for work tasks can be validly assessed with the SFS in a European rehabilitation setting in patients with non-specific low back pain, and is predictive for future work status.

Embryonic exposure to corticosterone modifies the juvenile stress response, oxidative stress, and telomere length.

Early embryonic exposure to maternal glucocorticoids can broadly impact physiology and behaviour across phylogenetically diverse taxa. The transfer of maternal glucocorticoids to offspring may be an inevitable cost associated with poor environmental conditions, or serve as a maternal effect that alters offspring phenotype in preparation for a stressful environment. Regardless, maternal glucocorticoids are likely to have both costs and benefits that are paid and collected over different developmental time periods. We manipulated yolk corticosterone (cort) in domestic chickens (Gallus domesticus) to examine the potential impacts of embryonic exposure to maternal stress on the juvenile stress response and cellular ageing. Here, we report that juveniles exposed to experimentally increased cort in ovo had a protracted decline in cort during the recovery phase of the stress response. All birds, regardless of treatment group, shifted to oxidative stress during an acute stress response. In addition, embryonic exposure to cort resulted in higher levels of reactive oxygen metabolites and an over-representation of short telomeres compared with the control birds. In many species, individuals with higher levels of oxidative stress and shorter telomeres have the poorest survival prospects. Given this, long-term costs of glucocorticoid-induced phenotypes may include accelerated ageing and increased mortality.

Protein disulfide isomerase blocks CEBPA translation and is up-regulated during the unfolded protein response in AML

Deregulation of the myeloid key transcription factor CEBPA is a common event in acute myeloid leukemia (AML). We previously reported that the chaperone calreticulin is activated in subgroups of AML patients and that calreticulin binds to the stem loop region of the CEBPA mRNA, thereby blocking CEBPA translation. In this study, we screened for additional CEBPA mRNA binding proteins and we identified protein disulfide isomerase (PDI), an endoplasmic reticulum (ER) resident protein, to bind to the CEBPA mRNA stem loop region. We found that forced PDI expression in myeloid leukemic cells in fact blocked CEBPA translation, but not transcription, whereas abolishing PDI function restored CEBPA protein. In addition, PDI protein displayed direct physical interaction with calreticulin. Induction of ER stress in leukemic HL60 and U937 cells activated PDI expression, thereby decreasing CEBPA protein levels. Finally, leukemic cells from 25.4% of all AML patients displayed activation of the unfolded protein response as a marker for ER stress, and these patients also expressed significantly higher PDI levels. Our results indicate a novel role of PDI as a member of the ER stress-associated complex mediating blocked CEBPA translation and thereby suppressing myeloid differentiation in AML patients with activated unfolded protein response (UPR).

Vascular tissue reaction to acute malapposition in human coronary arteries: sequential assessment with optical coherence tomography

The vascular tissue reaction to acute incomplete stent apposition (ISA) is not well known. The aim of this study was to characterize the vascular response to acute ISA in vivo and to look for predictors of incomplete healing.

RecNcMIC3-1-R is a microneme- and rhoptry-based chimeric antigen that protects against acute neosporosis and limits cerebral parasite load in the mouse model for Neospora caninum infection

In order to achieve host cell entry, the apicomplexan parasite Neospora caninum relies on the contents of distinct organelles, named micronemes, rhoptries and dense granules, which are secreted at defined timepoints during and after host cell entry. It was shown previously that a vaccine composed of a mixture of three recombinant antigens, corresponding to the two microneme antigens NcMIC1 and NcMIC3 and the rhoptry protein NcROP2, prevented disease and limited cerebral infection and transplacental transmission in mice. In this study, we selected predicted immunogenic domains of each of these proteins and created four different chimeric antigens, with the respective domains incorporated into these chimers in different orders. Following vaccination, mice were challenged intraperitoneally with 2 × 10(6)N. caninum tachzyoites and were then carefully monitored for clinical symptoms during 4 weeks post-infection. Of the four chimeric antigens, only recNcMIC3-1-R provided complete protection against disease with 100% survivors, compared to 40-80% of survivors in the other groups. Serology did not show any clear differences in total IgG, IgG1 and IgG2a levels between the different treatment groups. Vaccination with all four chimeric variants generated an IL-4 biased cytokine expression, which then shifted to an IFN-γ-dominated response following experimental infection. Sera of recNcMIC3-1-R vaccinated mice reacted with each individual recombinant antigen, as well as with three distinct bands in Neospora extracts with similar Mr as NcMIC1, NcMIC3 and NcROP2, and exhibited distinct apical labeling in tachyzoites. These results suggest that recNcMIC3-1-R is an interesting chimeric vaccine candidate and should be followed up in subsequent studies in a fetal infection model.

Acute pulmonary edema and airway hemorrhage in a goat during sevoflurane anesthesia

A goat was scheduled for experimental surgery under general anesthesia. The first attempt of performing endotracheal intubation failed and provoked laryngeal spasm. After repeated succesful intubation of inhalation anesthesia was delivered in high concentrations of sevoflurane. Suddenly hypertension and tachycardia were observed, followed by foamy airway secretion and then severe airway hemorrhage. The authors hypothesize that laryngeal spasm provoked respiratory distress and pulmonary edema. The delivered high concentrations of sevoflurane probably enhanced a hyperadrenergic response, predisposing to the development of airway hemorrhage.

Analgesic and anti-inflammatory actions of robenacoxib in acute joint inflammation in dog

The objectives of this study were to establish dose-response and blood concentration-response relationships for robenacoxib, a novel nonsteroidal anti-inflammatory drug with selectivity for inhibition of the cyclooxygenase (COX)-2 isoenzyme, in a canine model of synovitis. Acute synovitis of the stifle joint was induced by intra-articular injection of sodium urate crystals. Robenacoxib (0.25, 0.5, 1.0, 2.0 and 4.0 mg/kg), placebo and meloxicam (0.2 mg/kg) were administered subcutaneously (s.c.) 3 h after the urate crystals. Pharmacodynamic endpoints included data from forceplate analyses, clinical orthopaedic examinations and time course of inhibition of COX-1 and COX-2 in ex vivo whole blood assays. Blood was collected for pharmacokinetics. Robenacoxib produced dose-related improvement in weight-bearing, pain and swelling as assessed objectively by forceplate analysis (estimated ED(50) was 1.23 mg/kg for z peak force) and subjectively by clinical orthopaedic assessments. The analgesic and anti-inflammatory effects of robenacoxib were significantly superior to placebo (0.25-4 mg/kg robenacoxib) and were non-inferior to meloxicam (0.5-4 mg/kg robenacoxib). All dosages of robenacoxib produced significant dose-related inhibition of COX-2 (estimated ED(50) was 0.52 mg/kg) but no inhibition of COX-1. At a dosage of 1-2 mg/kg administered s.c., robenacoxib should be at least as effective as 0.2 mg/kg of meloxicam in suppressing acute joint pain and inflammation in dogs.

Health-related quality of life in long-term survivors of relapsed childhood acute lymphoblastic leukemia

Background Relapses occur in about 20% of children with acute lymphoblastic leukemia (ALL). Approximately one-third of these children can be cured. Their risk for late effects is high because of intensified treatment, but their health-related quality of life (HRQOL) was largely unmeasured. Our aim was to compare HRQOL of ALL survivors with the general population, and of relapsed with non-relapsed ALL survivors. Methodology/Principal Findings As part of the Swiss Childhood Cancer Survivor Study (SCCSS) we sent a questionnaire to all ALL survivors in Switzerland who had been diagnosed between 1976–2003 at age <16 years, survived ≥5 years, and were currently aged ≥16 years. HRQOL was assessed with the Short Form-36 (SF-36), which measures four aspects of physical health and four aspects of mental health. A score of 50 corresponded to the mean of a healthy reference population. We analyzed data from 457 ALL survivors (response: 79%). Sixty-one survivors had suffered a relapse. Compared to the general population, ALL survivors reported similar or higher HRQOL scores on all scales. Survivors with a relapse scored lower in general health perceptions (51.6) compared to those without (55.8;p=0.005), but after adjusting for self-reported late effects, this difference disappeared. Conclusion/Significance Compared to population norms, ALL survivors reported good HRQOL, even after a relapse. However, relapsed ALL survivors reported poorer general health than non-relapsed. Therefore, we encourage specialists to screen for poor general health in survivors after a relapse and, when appropriate, specifically seek and treat underlying late effects. This will help to improve patients’ HRQOL.

Azacytidine for acute myeloid leukemia in elderly or frail patients: A phase II trial (SAKK 30/07)

Abstract This phase II trial treated elderly or frail AML patients with single agent subcutaneous azacytidine at 100 mg/m(2), on 5 of 28 days for up to 6 cycles. Treatment was stopped for lack of response, or continued to progression in responders. Primary endpoint was response within 6 months. A response rate >34% was considered a positive trial outcome. From 9/2008-4/2010, 45 patients from 10 centres (median age 74 (55-86) years) were accrued. Patients received 4 (1-21) cycles. Best response was CR/CRi in 8 (18%; 95% CI: 8%-32%.), 0 (0%) PR, 7 (16%) hematologic improvement, 17 (38%) stable disease. Three nonresponding patients stopped treatment after 6 cycles, 31 patients had stopped early and 11 patients continued treatment for 8-21 cycles. Adverse events (grade >III) were infections (13), febrile neutropenia (14), thrombocytopenia (7), dyspnea (6), bleeding (5) and anemia (4 patients). Median overall survival was 6 months. Peripheral blood blast counts, grouped at 30% had a borderline significant association with response (p = 0.07). This modified azacytidine schedule is feasible for elderly or frail AML patients in an outpatient setting with moderate, mainly hematologic, toxicity and response in a proportion of patients, although the primary objective was not reached.

Involvement of drug-specific T cells in acute drug-induced interstitial nephritis

Drug-induced interstitial nephritis can be caused by a plethora of drugs and is characterized by a sudden impairment of renal function, mild proteinuria, and sterile pyuria. For investigation of the possible pathomechanism of this disease, drug-specific T cells were analyzed, their function was characterized, and these in vitro findings were correlated to histopathologic changes that were observed in kidney biopsy specimens. Peripheral blood mononuclear cells from three patients showed a proliferative response to only one of the administered drugs, namely flucloxacillin, penicillin G, and disulfiram, respectively. The in vitro analysis of the flucloxacillin-reactive cells showed an oligoclonal immune response with an outgrowth of T cells bearing the T cell receptor Vbeta9 and Vbeta21.3. Moreover, flucloxacillin-specific T cell clones could be generated from peripheral blood, they expressed CD4 and the alphabeta-T cell receptor, and showed a heterogeneous cytokine secretion pattern with no clear commitment to either a Th1- or Th2-type response. The immunohistochemistry of kidney biopsies of these patients revealed cell infiltrations that consisted mostly of T cells (CD4+ and/or CD8+). An augmented presence of IL-5, eosinophils, neutrophils, CD68+ cells, and IL-12 was observed. In agreement with negative cytotoxicity assays, no cytotoxicity-related molecules such as Fas and perforin were detected by immunohistochemistry. The data indicate that drug-specific T cells are activated locally and orchestrate a local inflammation via secretion of various cytokines, the type of which depends on the cytokine pattern secreted and which probably is responsible for the renal damage.

Sleep-disordered breathing and acute ischemic stroke: diagnosis, risk factors, treatment, evolution, and long-term clinical outcome

BACKGROUND AND PURPOSE: Sleep-disordered breathing (SDB) is frequent in stroke patients. Risk factors, treatment response, short-term and long-term outcome of SDB in stroke patients are poorly known. METHODS: We prospectively studied 152 patients (mean age 56+/-13 years) with acute ischemic stroke. Cardiovascular risk factors, Epworth sleepiness score (ESS), stroke severity/etiology, and time of stroke onset were assessed. The apnea-hypopnea index (AHI) was determined 3+/-2 days after stroke onset and 6 months later (subacute phase). Continuous positive airway pressure (CPAP) treatment was started acutely in patients with SDB (AHI > or =15 or AHI > or =10+ESS >10). CPAP compliance, incidence of vascular events, and stroke outcome were assessed 60+/-16 months later (chronic phase). RESULTS: Initial AHI was 18+/-16 (> or =10 in 58%, > or =30 in 17% of patients) and decreased in the subacute phase (P<0.001). Age, diabetes, and nighttime stroke onset were independent predictors of AHI (r2=0.34). In patients with AHI > or =30, age, male gender, body mass index, diabetes, hypertension, coronary heart disease, ESS, and macroangiopathic etiology of stroke were significantly higher/more common than in patients with AHI <10. Long-term incidence of vascular events and stroke outcome were similar in both groups. CPAP was started in 51% and continued chronically in 15% of SDB pts. Long-term stroke mortality was associated with initial AHI, age, hypertension, diabetes, and coronary heart disease. CONCLUSIONS: SDB is common particularly in elderly stroke male patients with diabetes, nighttime stroke onset, and macroangiopathy as cause of stroke; it improves after the acute phase, is associated with an increased poststroke mortality, and can be treated with CPAP in a small percentage of patients.

Gene expression in cortex and hippocampus during acute pneumococcal meningitis

BACKGROUND: Pneumococcal meningitis is associated with high mortality (approximately 30%) and morbidity. Up to 50% of survivors are affected by neurological sequelae due to a wide spectrum of brain injury mainly affecting the cortex and hippocampus. Despite this significant disease burden, the genetic program that regulates the host response leading to brain damage as a consequence of bacterial meningitis is largely unknown.We used an infant rat model of pneumococcal meningitis to assess gene expression profiles in cortex and hippocampus at 22 and 44 hours after infection and in controls at 22 h after mock-infection with saline. To analyze the biological significance of the data generated by Affymetrix DNA microarrays, a bioinformatics pipeline was used combining (i) a literature-profiling algorithm to cluster genes based on the vocabulary of abstracts indexed in MEDLINE (NCBI) and (ii) the self-organizing map (SOM), a clustering technique based on covariance in gene expression kinetics. RESULTS: Among 598 genes differentially regulated (change factor > or = 1.5; p < or = 0.05), 77% were automatically assigned to one of 11 functional groups with 94% accuracy. SOM disclosed six patterns of expression kinetics. Genes associated with growth control/neuroplasticity, signal transduction, cell death/survival, cytoskeleton, and immunity were generally upregulated. In contrast, genes related to neurotransmission and lipid metabolism were transiently downregulated on the whole. The majority of the genes associated with ionic homeostasis, neurotransmission, signal transduction and lipid metabolism were differentially regulated specifically in the hippocampus. Of the cell death/survival genes found to be continuously upregulated only in hippocampus, the majority are pro-apoptotic, while those continuously upregulated only in cortex are anti-apoptotic. CONCLUSION: Temporal and spatial analysis of gene expression in experimental pneumococcal meningitis identified potential targets for therapy.