1,392 research outputs found
Surfactant protein D contributes to ocular defense against Pseudomonas aeruginosa in a murine model of dry eye disease.
Dry eye disease can cause ocular surface inflammation that disrupts the corneal epithelial barrier. While dry eye patients are known to have an increased risk of corneal infection, it is not known whether there is a direct causal relationship between these two conditions. Here, we tested the hypothesis that experimentally-induced dry eye (EDE) increases susceptibility to corneal infection using a mouse model. In doing so, we also examined the role of surfactant protein D (SP-D), which we have previously shown is involved in corneal defense against infection. Scopolamine injections and fan-driven air were used to cause EDE in C57BL/6 or Black Swiss mice (wild-type and SP-D gene-knockout). Controls received PBS injections and were housed normally. After 5 or 10 days, otherwise uninjured corneas were inoculated with 10(9) cfu of Pseudomonas aeruginosa strain PAO1. Anesthesia was maintained for 3 h post-inoculation. Viable bacteria were quantified in ocular surface washes and corneal homogenates 6 h post-inoculation. SP-D was measured by Western immunoblot, and corneal pathology assessed from 6 h to 4 days. EDE mice showed reduced tear volumes after 5 and 10 days (each by ∼75%, p<0.001) and showed fluorescein staining (i.e. epithelial disruption). Surprisingly, there was no significant difference in corneal pathology between EDE mice and controls (∼10-14% incidence). Before bacterial inoculation, EDE mice showed elevated SP-D in ocular washes. After inoculation, fewer bacteria were recovered from ocular washes of EDE mice (<2% of controls, p = 0.0004). Furthermore, SP-D knockout mice showed a significant increase in P. aeruginosa corneal colonization under EDE conditions. Taken together, these data suggest that SP-D contributes to corneal defense against P. aeruginosa colonization and infection in EDE despite the loss of barrier function to fluorescein
Methorics of the Precipitation Processes. XXIV. Flocculation Phenomena of Non-Ionic Surface-Active Agents on Silver Iodide Sols
An explanation concerning the flocculation and stabilization
action of non-ionic surface-active agents (NSAA) T-X-305 and
T-X-705 on the negatively and positively charged silver iodide
stable sols was attempted by means of tyndallometric and microscopic
investigations.
The flocculation phenomena were found to occur in the concentrational
region of 10-7 to 10-4 mol dm·3 of triton. The influence
of temperature, time, and sol concentration on the kinetics of the
formation of colloid particles was also examined . The mechanism
of flocculation· processes was suggested by assuming that the flocculation
and stabilization of Ag! colloid in the presence of NSAA
is a heterogeneous precipitation characterized by the critical concentrational
and temporal parameters
The Retail FX Trader: Random Trading and the Negative Sum Game
With the internet boom of early 2000 making access to trading the Foreign Exchange (FX) market far simpler for members of the general public, the growth of 'retail' FX trading continues, with daily transaction volumes as high as $200 billion. Potential new entrants to the retail FX trading world may come from the recent UK pension deregulations, further increasing the volumes. The attraction of FX trading is that it offers high returns and whilst it has been understood that it is high-risk in nature, the rewards are seen as being commensurately high for the 'skilled and knowledgeable' trader who has an edge over other market participants. This paper analyses a number of independent sources of data and previous research, to examine the profitability of the Retail FX trader and compares the results with that of a simulated random trading models. This paper finds evidence to suggest that whilst approximately 20% of traders can expect to end up with a profitable account, around 40% might expect their account to be subject to a margin call. This paper finds a strong correlation between the overall profitability of traders and impact of the cost of the bid-ask spread, whilst finding little if any evidence that retail FX traders, when viewed as a group, are achieving results better than that from random trading
Active rests during the work process
Svaki rad, osobito profesionalni, stvara umor koji smanjuje radnu učinkovitost. Aktivni odmori s izabranim rekreacijskim aktivnostima ugrađeni u proces rada vrlo su djelotvorni u uklanjanju simptoma umora. Članak iznosi primjere i mehanizme bržeg urađivanja i oporavka, koji su povezani s programiranom tjelesnom aktivnosti na početku rada, u vrijeme redovitih i/ili dodatnih odmora sukladno utvrđenom kritičnom vremenu u tijeku osmosatne radne smjene.Every work, especially professional work, induces fatigue whteh diminishes work efficacy. Active rests with aim-oriented recreational activities implemented in the work process are very efficacious in removing fatigue symptoms, The paper discusses examples and mechanisms of making work and recovery faster and more successful by programming physical activity at the beginning of work and during regular and added rests in accordance with the established critical time during the eight-hour work shift
Effect of active immunization against growth hormone releasing factor on concentrations of somatotropin and insulin-like growth factor I in lactating beef cows
Two experiments were conducted to determine the effects of immunoneutralization of growth hormone-releasing factor [GRF(1–29)-NH2] on concentrations of somatotropin (ST) and insulin-like growth factor I (IGF-I) in lactating beef cows. In Experiment 1, multiparous Hereford cows were immunized against 2 mg GRF(1–29)-(Gly)4-Cys-NH2 conjugated to human serum albumin (GRFi, n=3) or 2 mg human serum albumin (HSAi, n=3) at 52 ± 1 d prior to parturition. Boosters (1 mg) were administered on days 12, 40 and 114 postpartum (pp). Serum samples were collected at 15-min intervals for 5 hr on days 18, 46 and 120 pp, followed by administration (IV) of an opioid agonist (FK33-824; 10 μg/kg) and an antagonist (naloxone; .5 mg/kg) at hours 5 and 7, respectively. A GRF-analog ([desamino-Tyr1, D-Ala2, Ala15] GRF (1–29)-NH2; 3.5 μg/kg) and arginine (.5 g/kg) were administered at hour 10 on days 47 and 121, respectively. Percentage binding of [125I]GRF (1:100 dilution of serum) 28 d after primary immunization was greater in GRFi (14.3 ± 4.9) than in HSAi (.7 ± .3) cows. Binding increased to 29.3 ± 6.5% after first booster in GRFi cows. Episodic release of ST was abolished by immunization against GRF; concentration and frequency of release of ST were lower (P125I]GRF, absence of pulsatile release of ST, low concentrations of ST and IGF-I and failure of ST to increase after IV opioid agonist or arginine
Differences in risk behaviours and HIV status between primary amphetamines and opioid injectors in Estonia and Russia
Background and objective People who inject drugs (PWID) account for over half of new HIV infections in Eastern Europe and central Asia, where opioids continue to be the dominant illicit drugs injected. Stimulants including amphetamines (ATS) have been associated with HIV infection risk in several settings. We sought to examine whether primary ATS injection was associated with greater HIV risk, compared to opioid injection in two European locales with significant HIV epidemics. Methods PWID in Kohtla-Järve and St. Petersburg were recruited using respondent-driven sampling in 2012–2013. Survey data on demographic characteristics, service use, injecting and sexual risk behaviours and HIV-status (and HCV in Kohtla-Järve) were compared between primary opioid and ATS injectors using logistic regression models. Results Of 591 injectors recruited in Kohtla-Järve and 811 in St. Petersburg, 195 (33%) and 27 (4%) primarily injected ATS in each city. In both cities, ATS injectors were younger than opioid injectors, initiated injection later, injected less frequently and were more likely to have been paid for sex. In both cities, PWID had high levels of multiple sex partners. In Kohtla-Järve, ATS-injectors had lower odds of back-loading and greater odds of polydrug use than opioid-injectors. In St. Petersburg, where over half of PWID reported unsafe sharing practices, ATS-injectors were less likely to report these practices. ATS-injection was negatively associated with being HIV positive in Kohtla-Järve (aOR = 0.6; 95%CI: 0.5–0.8) and St. Petersburg (aOR = 0.3; 95%CI: 0.1–0.7). ATS-injection was negatively associated with HCV-reactivity in Kohtla-Järve (aOR = 0.5; 95%CI: 0.3–0.6). Conclusions In both locations, primary ATS injection was associated with lower injecting risk behaviours, lower odds of HIV and being paid for sex compared to opioid injection. Interventions targeting the characteristics and needs of ATS injectors are needed to increase contact with services and reduce sexual and injecting risk. Harm reduction services, including sexual risk reduction, need to be expanded for all PWID in St. Petersburg
Ontogeny of synaptophysin and synaptoporin in the central nervous system
The expression of the synaptic vesicle antigens synaptophysin (SY) and synaptoporin (SO) was studied in the rat striatum, which contains a nearly homogeneous population of GABAergic neurons. In situ hybridization revealed high levels of SY transcripts in the striatal anlage from embryonic day (E) 14 until birth. In contrast. SO hybridization signals were low, and no immunoreactive cell bodies were detected at these stages of development. At E 14, SY-immunoreactivity was restricted to perikarya. In later prenatal stages of development SY-immunoreactivity appeared in puncta (identified as terminals containing immunostained synaptic vesicles), fibers, thick fiber bundles and ‘patches’. In postnatal and adult animals, perikarya of striatal neurons exhibited immunoreaction for SO; ultrastructurally SO antigen was found in the Golgi apparatus and in multivesicular bodies. SO-positive boutons were rare in the striatum. In the neuropil, numerous presynaptic terminals positive for SY were observed. Our data indicate that the expression of synaptic vesicle proteins in GABAergic neurons of the striatum is developmentally regulated. Whereas SY is prevalent during embryonic development, SO is the major synaptic vesicle antigen expressed postnatally by striatal neurons which project to the globus pallidus and the substantia nigra. In contrast synapses of striatal afferents (predominantly from cortex, thalamus and substantia nigra) contain SY
Alpha B-crystallin protects retinal tissue during Staphylococcus aureus-induced endophthalmitis
Bacterial infections of the eye highlight a dilemma that is central to all immune-privileged sites. On the one hand, immune privilege limits inflammation to prevent bystander destruction of normal tissue and loss of vision. On the other hand, bacterial infections require a robust inflammatory response for rapid clearance of the pathogen. We demonstrate that the retina handles this dilemma, in part, by activation of a protective heat shock protein. During Staphylococcus aureus-induced endophthalmitis, the small heat shock protein αB-crystallin is upregulated in the retina and prevents apoptosis during immune clearance of the bacteria. In the absence of αB-crystallin, mice display increased retinal apoptosis and retinal damage. We found that S. aureus produces a protease capable of cleaving αB-crystallin to a form that coincides with increased retinal apoptosis and tissue destruction. We conclude that αB-crystallin is important in protecting sensitive retinal tissue during destructive inflammation that occurs during bacterial endophthalmitis
- …