Influence of systemic inflammatory response syndrome and sepsis on outcome of critically ill infected patients

The clinical significance of the systemic inflammatory response in infected patients remains unclear. We examined risk factors for hospital mortality in 3,608 intensive care unit patients included in the European Sepsis Study. Patients were categorized as having infection without or with (i.e., sepsis) systemic inflammatory response, severe sepsis, and septic shock, on the first day of infection. Hospital mortality varied from 25 to 60% according to sepsis stage, but did not differ between the first two categories (hazard ratio, 0.94; p = 0.55), whereas there was a grading of severity from sepsis to severe sepsis (1.53, p < 10-4) and septic shock (2.64, p < 10-4). Within each stage, mortality was unaffected by the number of inflammatory response criteria. Prognostic factors identified by Cox regression included comorbid conditions, severity of acute illness and acute organ dysfunction, shock, nosocomial infection, and infection caused by aerobic gram-negative bacilli, enterobacteria, Staphylococcus aureus, and infection from a digestive or unknown source. We conclude that whereas the categorization of infection by the presence of organ dysfunction or shock has strong prognostic significance, infection and sepsis have similar outcomes, unaffected by the presence or number of inflammatory response criteria. Refinement of risk stratification of patients presenting with infection and no organ dysfunction is needed.     

Molecular mechanisms of angiotensin II-mediated mitochondrial dysfunction: linking mitochondrial oxidative damage and vascular endothelial dysfunction

Mitochondrial dysfunction is a prominent feature of most cardiovascular diseases. Angiotensin (Ang) II is an important stimulus for atherogenesis and hypertension; however, its effects on mitochondrial function remain unknown. We hypothesized that Ang II could induce mitochondrial oxidative damage that in turn might decrease endothelial nitric oxide (NO.) bioavailability and promote vascular oxidative stress. The effect of Ang II on mitochondrial ROS, mitochondrial respiration, membrane potential, glutathione, and endothelial NO. was studied in isolated mitochondria and intact bovine aortic endothelial cells using electron spin resonance, dihydroethidium high-performance liquid chromatography -based assay, Amplex Red and cationic dye fluorescence. Ang II significantly increased mitochondrial H2O2 production. This increase was blocked by preincubation of intact cells with apocynin (NADPH oxidase inhibitor), uric acid (scavenger of peroxynitrite), chelerythrine (protein kinase C inhibitor), N(G)-nitro-L-arginine methyl ester (nitric oxide synthase inhibitor), 5-hydroxydecanoate (mitochondrial ATP-sensitive potassium channels inhibitor), or glibenclamide. Depletion of p22(phox) subunit of NADPH oxidase with small interfering RNA also inhibited Ang II-mediated mitochondrial ROS production. Ang II depleted mitochondrial glutathione, increased state 4 and decreased state 3 respirations, and diminished mitochondrial respiratory control ratio. These responses were attenuated by apocynin, 5-hydroxydecanoate, and glibenclamide. In addition, 5-hydroxydecanoate prevented the Ang II-induced decrease in endothelial NO. and mitochondrial membrane potential. Therefore, Ang II induces mitochondrial dysfunction via a protein kinase C-dependent pathway by activating the endothelial cell NADPH oxidase and formation of peroxynitrite. Furthermore, mitochondrial dysfunction in response to Ang II modulates endothelial NO. and generation, which in turn has ramifications for development of endothelial dysfunction.     

The effect of submicron fat droplets in a drink on satiety,food intake,and cholecystokinin in healthy volunteers

Purpose

Small fat droplets infused into the gut reduce food intake and hunger more than bigger ones, at levels as low as 6 g, and these effects are hypothesized to occur via satiety hormones such as cholecystokinin. It is, however, unknown whether the effect of droplet size would persist after oral consumption. It is also unknown whether an even smaller droplet size can affect hunger and food intake and at what minimum amount of fat. Therefore, the aim of the study was to test the effect of very fine fat droplets on satiety and food intake in two different quantities.

Methods

In a balanced-order 4-way crossover design, 24 volunteers consumed a fat-free meal replacement drink with either 5 or 9 g oil (rapeseed) and either 3 or 0.1 μm droplet size. Appetite scores and plasma cholecystokinin levels (in n = 12 subset) were measured for 180 min, when food intake was assessed during an ad libitum meal. Data were analyzed by ANCOVA, followed by Dunnett’s test and paired t test. The behavior of the emulsions was also characterized in a simulated gastrointestinal model.

Results

Despite faster in vitro lipolysis of the smallest droplets, neither droplet size nor fat amount affected satiety or food intake. From t = 45–150 min, cholecystokinin response was 50 % higher (P < 0.05) after the 0.1 versus 3 μm, but only with 9 g fat.

Conclusion

When this particular fat at these amounts is delivered in a meal replacement drink, droplet size does not influence appetite or food intake. This effect is independent of the amount of fat or plasma cholecystokinin changes.     

Prognostic factors and efficacy of different chemotherapeutic regimens in patients with mediastinal nonseminomatous germ cell tumors

Purpose

Patients (pts) with mediastinal nonseminomatous germ cell tumors (MNGCT) are belonged to poor prognostic group by IGCCCG. We retrospectively studied the prognostic factors and efficacy of different chemotherapeutic regimen in pts with MNGCT.

Methods

We analyzed data on 61 pts with MNGCT. Conditional induction chemotherapy BEP was performed in 38 %, TBEP—in 28 %, CBOP—in 28 %, accelerated (two weekly) version of BEP—in 6 % pts. Based on similar efficacy of CBOP and TBEP regimens, we combines pts with CPOB and TBEP regimen in one group—55.8 % and different variants of BEP regimen in the second group—44.2 %. Multivariate Cox regression analysis was performed to determine independent factors, which influenced on overall survival.

Results

We revealed the following independent negative prognostic factors: age ≥24 years (p = 0.07), size of the primary mediastinal tumor ≥19 cm (p = 0.03). Median overall survival (OS) has not been reached, and 2-year OS was 66 % in pts with good prognosis (age <24 years and/or size of mediastinal tumor <19 cm) versus 15 months and 40 % in pts with poor prognosis (p = 0.03). Objective marker negative response was revealed more often in pts with CPOB/TBEP group: 26/34 (76.5 %) versus 14/27 (52 %), p = 0.08. Median OS was also higher in pts with CPOB/TBEP group: nonreached versus 15 months (p = 0.01).

Conclusion

CPOB and TBEP regimen were significantly associated with better outcome in pts with MNGCT. Age ≥24 years and size of the primary mediastinal tumor ≥19 cm were found as independent negative prognostic factors.     

Mapping the diatom redox-sensitive proteome provides insight into response to nitrogen stress in the marine environment

Diatoms are ubiquitous marine photosynthetic eukaryotes responsible for approximately 20% of global photosynthesis. Little is known about the redox-based mechanisms that mediate diatom sensing and acclimation to environmental stress. Here we used a quantitative mass spectrometry-based approach to elucidate the redox-sensitive signaling network (redoxome) mediating the response of diatoms to oxidative stress. We quantified the degree of oxidation of 3,845 cysteines in the Phaeodactylum tricornutum proteome and identified approximately 300 redox-sensitive proteins. Intriguingly, we found redox-sensitive thiols in numerous enzymes composing the nitrogen assimilation pathway and the recently discovered diatom urea cycle. In agreement with this finding, the flux from nitrate into glutamine and glutamate, measured by the incorporation of ¹⁵N, was strongly inhibited under oxidative stress conditions. Furthermore, by targeting the redox-sensitive GFP sensor to various subcellular localizations, we mapped organelle-specific oxidation patterns in response to variations in nitrogen quota and quality. We propose that redox regulation of nitrogen metabolism allows rapid metabolic plasticity to ensure cellular homeostasis, and thus is essential for the ecological success of diatoms in the marine ecosystem.Aerobic organisms produce reactive oxygen species (ROS) as a byproduct of oxygen-based metabolic pathways, such as photosynthesis, photorespiration, and oxidative phosphorylation (1). Perturbations in oxygenic metabolism under various stress conditions can induce oxidative stress from overproduction of ROS (2, 3). Because ROS are highly reactive forms of oxygenic metabolites, critical mechanisms for ROS detoxification have evolved consisting of ROS-scavenging enzymes and small molecules, including glutathione (GSH) (4). As the most abundant low molecular weight thiol antioxidant, GSH has critical roles in maintaining a proper cellular thiol–disulfide balance and in detoxifying H₂O₂ via the ascorbate–GSH cycle (5).Although classically ROS were considered toxic metabolic byproducts that ultimately lead to cell death, it is now recognized that ROS act as central secondary messengers involved in compartmentalized signaling networks (1, 6–8). Modulation of various cell processes by ROS signaling is mediated largely by posttranslational thiol oxidation, whereby their physical structure and biochemical activity are modified upon oxidation (9). Thus, the redox states of these proteins possess crucial information needed for cell acclimation to stress conditions (10, 11). The emergence of advanced redox proteomic approaches, such as the OxICAT method (12), has created new opportunities to identify redox-sensitive proteins (e.g., redoxome) on the system level and to quantify their precise level of oxidation on exposure to environmental stress conditions.Marine photosynthetic microorganisms (phytoplankton) are the basis of marine food webs. Despite the fact that their biomass represents only approximately 0.2% of the photosynthetic biomass on earth, they are responsible for nearly 50% of the annual global carbon-based photosynthesis and greatly influence the global biogeochemical carbon cycle (13). This high ratio of productivity to biomass, reflected in high turnover rates, makes phytoplankton highly responsive to climate change. Phytoplankton can grow rapidly and form massive blooms that stretch over hundreds of kilometers in the oceans and are regulated by such environmental factors as nutrient availability and biotic interactions with grazers and viruses.Diatoms are a highly diverse clade of phytoplankton, responsible for roughly 20% of global primary productivity (14). Consequently, diatoms play a central role in the biogeochemical cycling of important nutrients, including carbon, nitrogen, and silica, which constitute part of their ornate cell wall. As members of the eukaryotic group known as stramenopiles (or heterokonts), diatoms are derived from a secondary endosymbiotic event involving red and green algae engulfed within an ancestral protest (15).The unique multilineage content of diatom genomes reveals a melting pot of biochemical characteristics that resemble bacterial, plant, and animal traits, including the integration of a complete urea cycle, fatty acid oxidation in the mitochondria, and plant C4-like related pathways (16, 17). During bloom succession, phytoplankton cells are subjected to diverse environmental stress conditions that lead to ROS production, such as allelopathic interactions (18), CO₂ availability (19, 20), UV exposure (21), iron limitation (22), and viral infection (23). Recently reported evidence suggests that diatoms possess a surveillance system based on the induction of ROS that have been implicated in response to various environmental stresses (22, 24). Nevertheless, very little is known about cell signaling processes in marine phytoplankton and their potential role in acclimation to rapid fluctuations in the chemophysical gradients in the marine environment (25).Using a mass spectrometry-based approach, we examined the diatom redoxome and quantified its degree of oxidation under oxidative stress conditions. The wealth of recently identified redox-sensitive proteins participating in various cellular functions suggests a fundamental role of redox regulation in diatom biology. We mapped the redox-sensitive enzymes into a metabolic network and evaluated their role in the adjustment of metabolic flux under variable environmental conditions. We further explored the redox sensitivity of the primary nitrogen-assimilating pathway and demonstrated the role of compartmentalized redox regulation in cells under nitrogen stress conditions using a redox-sensitive GFP sensor targeted to specific subcellular localizations.     

Molecular and biochemical study of glutaric aciduria type 1 in 49 Russian families: nine novel mutations in the GCDH gene

Metabolic Brain Disease - Glutaric aciduria type 1 (GA1, deficiency of glutaryl CoA dehydrogenase, glutaric acidemia type 1) (ICD-10 code: E72.3; MIM 231670) is an autosomal recessive disease...     

Trajectories of glycaemia following acute pancreatitis: a prospective longitudinal cohort study with 24 months follow-up

Journal of Gastroenterology - New-onset diabetes is the most common sequela of acute pancreatitis (AP). Yet, prospective changes in glycaemia over time have never been investigated comprehensively...