Acute induction of interleukin-6 and biphasic changes of serum complement C3 by carrageenan in mice.

Carrageenan has been widely used as an irritant to evoke inflammation in animals or to selectively deplete macrophages in vivo. Although precise understanding of carrageenan activity is a prerequisite for the experimental use of this polysaccharide, the effects of this agent on host-biological systems are still poorly understood. We investigated the effect of carrageenan on serum concentrations of complement C3 and interleukin (IL)-6, a potent complement-inducing factor. Intraperitoneal administration of carrageenan (4 mg) in mice resulted in an initial fall in serum C3 (70% of control, P < 0.05) between 3 and 6 h, but was followed by a significant rise (180% of the control, P < 0.05) at 24h. Prior to the rise in complement C3, a sharp peak of serum IL-6 was observed at 6h after carrageenan treatment. These results indicate potential of carrageenan to enhance host complement systems, which may be associated with, at least in part, an acute induction of IL-6

Skeletal muscle dysfunction is associated with derangements in mitochondrial bioenergetics (but not UCP3) in a rodent model of sepsis

Muscle dysfunction is a common feature of severe sepsis and multi-organ failure. Recent evidence implicates bioenergetic dysfunction and oxidative damage as important underlying pathophysiological mechanisms. Increased abundance of uncoupling protein-3 (UCP-3) in sepsis suggests increased mitochondrial proton leak, which may reduce mitochondrial coupling efficiency but limit ROS production. Using a murine model, we examined metabolic, cardiovascular and skeletal muscle contractile changes following induction of peritoneal sepsis in wild-type and Ucp3(-/-) mice. Mitochondrial membrane potential (Δψm) was measured using two-photon microscopy in living diaphragm, and contractile function was measured in diaphragm muscle strips. The kinetic relationship between membrane potential and oxygen consumption was determined using a modular kinetic approach in isolated mitochondria. Sepsis was associated with significant whole body metabolic suppression, hypothermia and cardiovascular dysfunction. Maximal force generation was reduced and fatigue accelerated in ex vivo diaphragm muscle strips from septic mice. Mitochondrial membrane potential was lower in the isolated diaphragm from septic mice despite normal substrate oxidation kinetics and proton leak in skeletal muscle mitochondria. Even though wild-type mice exhibited an absolute 26 ± 6% higher UCP-3 protein abundance at 24 hours, no differences were seen in whole animal or diaphragm physiology, nor in survival rates, between wild-type and Ucp3(-/-) mice. In conclusion, this murine sepsis model shows a hypometabolic phenotype with evidence of significant cardiovascular and muscle dysfunction. This was associated with lower Δψm and alterations in mitochondrial ATP turnover and phosphorylation pathway. However, UCP-3 does not play an important functional role, despite its upregulation

Glucose Tolerance and the Risk Factors for Transmission in Japanese SARS-CoV-2/WA-1/2020 Epicenter: A Retrospective Study

Manabu Saito,1,&ast; Hiroshi Uchino,1,&ast; Yoko Iwata,1 Ayako Fuchigami,1 Genki Sato,1 Fukumi Yoshikawa,1 Masahiko Miyagi,1 Taito Miyazaki,2 Yoshihisa Urita,2 Kotaro Aoki,3 Yoshikazu Ishii,3 Kazuhiro Tateda,3 Takahisa Hirose1 1Division of Diabetes, Metabolism and Endocrinology, Department of Internal Medicine, Toho University Graduate School of Medicine, Tokyo, Japan; 2Department of General Medicine and Emergency Care, Toho University School of Medicine, Tokyo, Japan; 3Department of Microbiology and Infectious Diseases, Toho University School of Medicine, Tokyo, Japan&ast;These authors contributed equally to this workCorrespondence: Hiroshi Uchino, Division of Diabetes, Metabolism and Endocrinology, Department of Internal Medicine, Toho University Graduate School of Medicine, 6-11-1 Omori-nishi, Ota-ku, Tokyo, 143-8541, Japan, Tel +81-3-3762-4151, Fax +81-3-3765-6488, Email [email protected]: The severe pathogenic ancient-type COVID-19, SARS-CoV-2/WA-1/2020 was the predominant gene variant in early 2020 in Japan, however, its transmissibility was uncertain. The period before the public commenced using any personal protective equipment (PPE) was evaluating to describe the transmissibility of the SARS-CoV-2/WA-1/2020. We analyzed the secondary attack rate (SAR) among close contacts and the risk factor for SAR.Methods: This retrospective cohort study included a total of 539 patients who were anticipated for the SARS-CoV-2/WA-1/2020 infection at Toho University Medical Center Omori Hospital from February to May 2020. We selected 54 patients with 1) exclude other pathogens infection, 2) include “Three Cs” condition: crowded places between distance 15min with a person tested positive for SARS-CoV-2/WA-1/2020 without PPE. We evaluated alternative infection risks: the body mass index (BMI) and diabetes (DM) status (non-DM, pre-DM, and DM) as demographic determinants of transmissibility and infectivity of SARS-CoV2/WA-1/2020 cases during the incubation period.Results: The calculated SAR was 79.3%. BMI was significantly associated with the PCR positivity rate, which was significant in the univariate (CI 95%, 1.02– 1.51; P = 0.03) and multivariate (CI 95%, 1.02– 1.60; P = 0.03) analyses. Comparing the different BMI groups, the highest BMI group (25.5− 35.8 kg/m2) had an elevated risk of SAR compared to the lowest BMI group (14.0– 22.8 kg/m2), with an odds ratio of 1.41 (95% CI, 1.02– 1.59; P = 0.03). There were no significant differences in the risk of SAR among different DM statuses.Conclusion: The transmissibility of SARS-CoV2/WA-1/2020 was high (79.3%) among household members without PPE who had “Three Cs” exposure. Although pre-DM and established DM did not confer a risk for transmissibility, higher BMI was associated with an increased risk of SAR.Trial Registration: UMIN Clinical Trials Registry, UMIN0000 50905.Keywords: obesity, pre-diabetes, SARS-CoV-2 transmissio

Review: optical fiber sensors for civil engineering applications

Optical fiber sensor (OFS) technologies have developed rapidly over the last few decades, and various types of OFS have found practical applications in the field of civil engineering. In this paper, which is resulting from the work of the RILEM technical committee “Optical fiber sensors for civil engineering applications”, different kinds of sensing techniques, including change of light intensity, interferometry, fiber Bragg grating, adsorption measurement and distributed sensing, are briefly reviewed to introduce the basic sensing principles. Then, the applications of OFS in highway structures, building structures, geotechnical structures, pipelines as well as cables monitoring are described, with focus on sensor design, installation technique and sensor performance. It is believed that the State-of-the-Art review is helpful to engineers considering the use of OFS in their projects, and can facilitate the wider application of OFS technologies in construction industry

Combined In Silico, In Vivo, and In Vitro Studies Shed Insights into the Acute Inflammatory Response in Middle-Aged Mice

We combined in silico, in vivo, and in vitro studies to gain insights into age-dependent changes in acute inflammation in response to bacterial endotoxin (LPS). Time-course cytokine, chemokine, and NO2-/NO3- data from "middle-aged" (6-8 months old) C57BL/6 mice were used to re-parameterize a mechanistic mathematical model of acute inflammation originally calibrated for "young" (2-3 months old) mice. These studies suggested that macrophages from middle-aged mice are more susceptible to cell death, as well as producing higher levels of pro-inflammatory cytokines, vs. macrophages from young mice. In support of the in silico-derived hypotheses, resident peritoneal cells from endotoxemic middle-aged mice exhibited reduced viability and produced elevated levels of TNF-α, IL-6, IL-10, and KC/CXCL1 as compared to cells from young mice. Our studies demonstrate the utility of a combined in silico, in vivo, and in vitro approach to the study of acute inflammation in shock states, and suggest hypotheses with regard to the changes in the cytokine milieu that accompany aging. © 2013 Namas et al

Quorum Sensing Inhibition Selects for Virulence and Cooperation in Pseudomonas aeruginosa

With the rising development of bacterial resistance the search for new medical treatments beyond conventional antimicrobials has become a key aim of public health research. Possible innovative strategies include the inhibition of bacterial virulence. However, consideration must be given to the evolutionary and environmental consequences of such new interventions. Virulence and cooperative social behaviour of the bacterium Pseudomonas aeruginosa rely on the quorum-sensing (QS) controlled production of extracellular products (public goods). Hence QS is an attractive target for anti-virulence interventions. During colonization, non-cooperating (and hence less virulent) P. aeruginosa QS-mutants, benefiting from public goods provided by wild type isolates, naturally increase in frequency providing a relative protection from invasive infection. We hypothesized that inhibition of QS-mediated gene expression removes this growth advantage and selection of less virulent QS-mutants, and maintains the predominance of more virulent QS-wild type bacteria. We addressed this possibility in a placebo-controlled trial investigating the anti-QS properties of azithromycin, a macrolide antibiotic devoid of bactericidal activity on P. aeruginosa, but interfering with QS, in intubated patients colonized by P. aeruginosa. In the absence of azithromycin, non-cooperating (and hence less virulent) lasR (QS)-mutants increased in frequency over time. Azithromycin significantly reduced QS-gene expression measured directly in tracheal aspirates. Concomitantly the advantage of lasR-mutants was lost and virulent wild-type isolates predominated during azithromycin treatment. We confirmed these results in vitro with fitness and invasion experiments. Azithromycin reduced growth rate of the wild-type, but not of the lasR-mutant. Furthermore, the lasR-mutant efficiently invaded wild-type populations in the absence, but not in the presence of azithromycin. These in vivo and in vitro results demonstrate that anti-virulence interventions based on QS-blockade diminish natural selection towards reduced virulence and therefore may increase the prevalence of more virulent genotypes in the Hospital environment. More generally, the impact of intervention on the evolution of virulence of pathogenic bacteria should be assessed

A two-component regulator induces the transmission phenotype of stationary-phase Legionella pneumophila

Pathogenic Legionella pneumophila evolved as a parasite of aquatic amoebae. To persist in the environment, the microbe must be proficient at both replication and transmission. In laboratory cultures, as nutrients become scarce a stringent response-like pathway coordinates exit from the exponential growth phase with induction of traits correlated with virulence, including motility. A screen for mutants that express the flagellin gene poorly identified five activators of virulence: LetA/LetS, a two-component regulator homologous to GacA/GacS of Pseudomonas and SirA/BarA of Salmonella ; the stationary-phase sigma factor RpoS; the flagellar sigma factor FliA; and a new locus, letE . Unlike wild type, post-exponential-phase letA and letS mutants were not motile, cytotoxic, sodium sensitive or proficient at infecting macrophages. L. pneumophila also required fliA to become motile, cytotoxic and to infect macrophages efficiently and letE to express sodium sensitivity and maximal motility and cytotoxicity. When induced to express RelA, all of the strains exited the exponential phase, but only wild type converted to the fully virulent form. In contrast, intracellular replication was independent of letA, letS, letE or fliA . Together, the data indicate that, as the nutrient supply wanes, ppGpp triggers a regulatory cascade mediated by LetA/ LetS, RpoS, FliA and letE that coordinates differentiation of replicating L. pneumophila to a transmissible form.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75531/1/j.1365-2958.2002.02884.x.pd