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Light sensing has been extensively characterized in the human pathogen Acinetobacter baumannii at environmental temperatures. However, the influence of light on the physiology and pathogenicity of human bacterial pathogens at temperatures found in warm-blooded hosts is still poorly understand. In this work, we show that Staphylococcus aureus, Acinetobacter baumannii, and Pseudomonas aeruginosa (ESKAPE) priority pathogens, which have been recognized by the WHO and the CDC as critical, can also sense and respond to light at temperatures found in human hosts. Most interestingly, in these pathogens, light modulates important pathogenicity determinants as well as virulence in an epithelial infection model, which could have implications in human infections. In fact, we found that alpha-toxin-dependent hemolysis, motility, and growth under iron-deprived conditions are modulated by light in S. aureus Light also regulates persistence, metabolism, and the ability to kill competitors in some of these microorganisms. Finally, light exerts a profound effect on the virulence of these pathogens in an epithelial infection model, although the response is not the same in the different species; virulence was enhanced by light in A. baumannii and S. aureus, while in A. nosocomialis and P. aeruginosa it was reduced. Neither the BlsA photoreceptor nor the type VI secretion system (T6SS) is involved in virulence modulation by light in A. baumannii Overall, this fundamental knowledge highlights the potential use of light to control pathogen virulence, either directly or by manipulating the light regulatory switch toward the lowest virulence/persistence configuration.IMPORTANCE Pathogenic bacteria are microorganisms capable of producing disease. Dangerous bacterial pathogens, such as Staphylococcus aureus, Pseudomonas aeruginosa, and Acinetobacter baumannii, are responsible for serious intrahospital and community infections in humans. Therapeutics is often complicated due to resistance to multiple antibiotics, rendering them ineffective. In this work, we show that these pathogens sense natural light and respond to it by modulating aspects related to their ability to cause disease; in the presence of light, some of them become more aggressive, while others show an opposite response. Overall, we provide new understanding on the behavior of these pathogens, which could contribute to the control of infections caused by them. Since the response is distributed in diverse pathogens, this notion could prove a general concept.

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It is known that pigs can acquire flavour preferences by brief social interactions with conspecifics that previously consumed a flavoured solid feed. However, there is no information about whether a flavoured solution could support flavour preferences through social transmission. Ninety-six pigs (49 days old) were housed in 12 pens (8 pigs/pen). Four animals per pen were randomly selected to act as observers and four as demonstrators. Demonstrator animals were temporarily moved to an empty pen where a protein solution was offered (porcine digestive peptides (PDPs), 4% weight/volume) with the addition of 0.075% aniseed (six pens) or garlic (six pens) powdered artificial flavours for 30 min. Afterwards, demonstrators were returned to interact with observer animals for 30 min. A choice test (30 min) between aniseed and garlic PDP was performed for each observer group after the interaction. Observers showed a higher intake of solutions previously consumed by their demonstrator conspecifics (648 v. 468 ml; SEM 61.36, P < 0.05). As with flavoured solid feeds, protein solutions containing artificial flavours can create preferences in pigs for those flavours through social transmission from conspecifics.

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Carbon nanotubes (CNT) can be chemically modified by doping or functionalization to change the chemical and surface properties. These characteristic makes to CNT candidates for multiple applications including medical field in cardiovascular area. A novel method to CNT functionalization by formation of two compounds: α-bromoacid and the organic compound 2-(methacryloyloxy) ethyl phosphorylcholine (MPC), will be discussed in this article. According to results, CNT are suggested like candidates to repel oxidized low-density lipoproteins (ox-LDL) to prevent restenosis. The electronegative character on surface of functionalized CNT (F-CNT) is shown by wettability analysis observing a repellent behaviour in contact with ox-LDL after functionalization route. Here we analyse the toxicity of CNT and F-CNT on HepG2 cell line and find no damage to the cell membrane of HepG2 cells in concentration at doses below 1mg/ml.

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PURPOSE: To evaluate an institute-specific CTV-PTV margin for head and neck (HN) patients according to a 3-mm action level protocol. METHODS/PATIENTS: Twenty-three HN patients were prospectively analysed. Patients were immobilized with a thermoplastic mask. Inter- and intrafractional set-up errors (in the three dimensions) were assessed from portal images (PI) registration. Digitally reconstructed radiographs (DRRs) were compared with two orthogonal PI by matching bone anatomy landmarks. The isocenter was verified during the first five consecutive days of treatment: if the mean error detected was greater than 2 mm the isocenter position was corrected for the rest of the treatment. Isocenter was checked weekly thereafter. Set-up images were obtained before and after treatment administration on 10, 20 and 30 fractions to quantify the intrafractional displacement. For the set-up errors, systematic (Σ), random (σ), overall standard deviations, and the overall mean displacement (M), were determined. CTV to PTV margin was calculated considering both inter- and intrafractional errors. RESULTS: A total of 396 portal images was analysed in 23 patients. Systematic interfractional (Σ(inter)) set-up errors ranged between 0.77 and 1.42 mm in the three directions, whereas the random (σ (inter)) errors were around 1-1.31 mm. Systematic intrafractional (Σ(intra)) errors ranged between 0.65 and 1.11 mm, whereas the random (σ (intra)) errors were around 1.13-1.16 mm. CONCLUSIONS: A verification protocol (3-mm action level) provided by EPIDs improves the set-up accuracy. Intrafractional error is not negligible and contributes to create a larger CTV-PTV margin. The appropriate CTV-PTV margin for our institute is between 3 and 4.5 mm considering both inter- and intrafractional errors.

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1. Activation of H(+) secretion in the intracellular canaliculi of parietal cells occurs on an unknown time scale with ill-defined kinetics for the coupling of H(+) secretion and the elevation of intracellular calcium ([Ca(2+)](i)) stimulated by secretagogues. 2. We developed a method to determine H(+) secretion in isolated rabbit gastric glands with spatio-temporal resolution, using the fluorescent indicator Lysosensor Yellow-Blue (LYB). Glands accumulated the dye exclusively in the intracellular canaliculi of parietal cells and the gland lumen. Dye fluorescence in the acid spaces of the glands increased upon stimulation of acid secretion by carbachol, histamine and forskolin. Simultaneous fluorescence measurements of acid secretion and [Ca(2+)](i) at 1 s resolution were made by joint loading of LYB and Fluo-3. 3. Carbachol-stimulated H(+) secretion was detected in the gland lumen as early as 3 s after the onset of the [Ca(2+)](i) spike. H(+) accumulation appeared to be transient and paralleled the release component of the [Ca(2+)](i) spike. Short and repetitive stimulations with carbachol elicited repetitive responses in [Ca(2+)](i) and H(+) secretion. 4. Histamine or forskolin stimulated H(+) secretion with a delayed onset (around 2 min) and a sustained response. Acid secretion was temporally unrelated to the oscillatory Ca(2+) responses. 5. The striking difference in the kinetics of activation of H(+) secretion by cholinergic and cAMP-dependent secretagogues indicates that two distinct mechanisms are operating in the final stimulation of the pump, in spite of both eliciting a [Ca(2+)](i) response.

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Palm kernel meal (PKM), a by-product from the African Palm oil industry that is extensively cultivated in tropical countries, is an interesting feed ingredient for poultry due to its availability and low cost. The objective of this study was to evaluate the use of different levels of PKM in layer diets. This particular PKM contained 9.70% crude protein, 0.20% methionine, 0.36% lysine, and a TMEn value of 2,254 kcal/kg. A control diet based on corn and soybean meal and five different levels of PKM added to it were fed to Single Comb White Leghorn hens from 18 to 38 wk of age. The PKM levels were 0, 10, 20, 30, 40, and 50%. The hens were housed three per cage (30.5 cm wide x 45.7 cm deep). The six treatments were assigned randomly to three contiguous cages in each of eight rows in a randomized complete block design. Egg production was recorded daily, and feed consumption for an entire week was recorded every 21 d. Egg weight and specific gravity were recorded for 3 consecutive d every 21 d. Mortality was recorded daily. Results show that egg production was significantly decreased (P < 0.05) only with 50% PKM in the diet. Feed conversion was not affected by any level of PKM. Specific gravity was slightly but significantly (P < 0.05) decreased by all levels of added PKM. Feed consumption, mortality, and egg weight did not differ significantly among the treatments. We concluded that this particular PKM may be used up to 40% in the diet, taking into account that specific gravity may be slightly decreased.

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Some viruses induce changes in membrane permeability during infection. We have shown previously that the porcine strain of rotavirus, OSU, induced an increase in the permeability to Na+, K+, and Ca2+ during replication in MA104 cells. In this work, we have characterized the divalent cation entry pathway by measuring intracellular Ca2+ in fura-2-loaded MA104 and HT29 cells in suspension. The permeability to Ca2+ and other cations was evaluated by the change of the intracellular concentration following an extracellular cation pulse. Rotavirus infection induced an increase in permeability to Ca2+, Ba2+, Sr2+, Mn2+, and Co2+. The rate of cation entry decreased over time as the intracellular concentration increased during the first 20 s. This indicates that regulatory mechanisms, including channel inactivation, are triggered. La3+ did not enter the cell and blocked the entry of the divalent cations in a dose-dependent manner. Metoxyverapamil (D600), a blocker of L-type voltage-gated channels, partially inhibited the entry of Ca2+ in virus-infected MA104 and HT29 cells. The results suggest that rotavirus infection of cultured cells activates a cation channel rather than nonspecific permeation through the plasma membrane. This activation involves the synthesis of viral proteins through mechanisms yet unknown. The increase in intracellular Ca2+ induced by the activation of this channel may be related to the increase in cytoplasmic and endoplasmic reticulum Ca2+ pools required for virus maturation and cell death.

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The Venezuelan Food Composition Table (VFCT) is being revised for the publication of the ninth edition within the Venezuelan Food Project. The majority of the RE values for plant foods given in the VFCT were taken from previous editions (1964-1973) and with few exceptions, still remains the same in the latest edition of 1994. These values were calculated from the total carotenoid content of food, determined by an open column method with no separation of the various carotenoids that might be present in the food. Recently it has been suggested that the accepted factors to convert beta-carotene and other carotenoids to RE (1/6 and 1/12, respectively) do not reflect the reality and the apparent mean vitamin A activity of leafy vegetables and carrot would be around 23% and fruits about 50% of that assumed until now. Percentages of the Venezuelan RDAs for vitamin A were calculated from vitamin A intake supplied by food consumption surveys, using the conversion factors corrected according to the above mentioned criteria. Percentages of the Venezuelan RDAs were again calculated with the vitamin A availability given by the Food Balance Sheet (1997), using two levels of RE in carrots: 2,800 ER and 850 ER. Results in these approaches differ markedly and indicate that the vitamin A nutrition status may be overestimated. If confirmed, this situation could influence the criteria and decisions in regard to food fortification and other strategies for controlling vitamin A deficiency.

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Rotavirus infection modifies the metabolism and ionic homeostasis of the host cell. First, there is an induction of viral synthesis with a parallel shutoff of cell protein production, followed by an increase of plasma membrane Ca2+ permeability, thereby inducing an increase of free cytoplasmic and sequestered Ca2+ concentrations. Cell death follows at a later stage. We studied the role of the increase in Ca2+ concentration in cell death. An elevation of extracellular Ca2+ concentration during infection induced an increase in [Ca2+]i and potentiated cell death. Buffering the increases in [Ca2+]i with BAPTA added at 6 h p.i. reduced the cytopathic effect without inhibiting viral protein synthesis and infectious particle production. Metoxyverapamil (D600), a Ca2+ channel inhibitor, added at 1 h p.i. reduced Ca2+ permeability, the increases in [Ca2+]i, and cell death produced by infection without modifying viral protein synthesis and infectious titer. Thapsigargin, the inhibitor of Ca(2+)-ATPase of endoplasmic reticulum, potentiated the increase of [Ca2+]i and accelerated the time course of cell death. Double staining with fluorescein diacetate and ethidium bromide or acridine orange and ethidium bromide showed that infected MA104 cells had lost plasma membrane integrity without DNA fragmentation or formation of apoptotic bodies. These results support the hypothesis that the increase in [Ca2+]i due to a product of viral protein synthesis triggers the chain of events that leads to cell death by oncosis.

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UNLABELLED: Morbi-mortality due to asthma has increased in recent years both throughout the world in Cuba. A study of mortality caused by this disease has conducted in order to describe its current trend in the country. METHOD: A time series study was conducted which included all deaths attributed to asthma in Cuba recorded in the vital statistics records of the Ministry of Public Health from 1972 to 1993. Rates, secular trends of general mortality and according to gender were estimated. The proportional mortality for the 1972-1993 period was calculated and the potential years of life lost during the 90-92 trienium were quantified. RESULTS AND DISCUSSION: A drop in these global rates occurred between 1972 and 1975, with values of 3.6; 4.1; 3.0; 2.2; respectively; possibly due to the introduction of disodic chromoglycate among other drugs and the beginning of the Asthmatic Patient Program. An later increase in mortality was observed until 1993 (5.9 x 100,000 inhabitants) which may attributed to a drop of the intensity and regularity of said program and to other internationally knowledge factors which are present in our country. The trend of general mortality rose during this period and was greater in females than in males; which means that the risk to die of this cause has increased. Proportional Mortality since 1980 (0.50%) also increased until 1993 (0.80%). Potential years of life lost due to premature death ranged from 5,646 in 1990 to 7,386 in 1992. The increase in proportional mortality and the potential years of life lost suggest that this disease should been given priority by the National Health Program as a preventable cause of death, especially in women. CONCLUSIONS: There is a rising trend of mortality among asthmatic patients during the period under consideration. Asthma is a cause of premature death in Cuba.

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The pure TdI-1 polypeptide that blocks miniature endplate potentials (MEPPs) and abolishes or reduces endplate potentials (EPPs) below the action potential threshold was identified from the crude fraction of Tityus discrepans venom. The toxin is a potent reversible non-depolarizing muscle relaxant that blocks more than 95% of the EPP at a 2 microM (0.1 mg/ml) concentration. On a molar basis, TdI-1 is as potent as or more potent than many muscle relaxants since, at the concentration used, the toxin suppressed more than 95% of the EPP. Using matrix-assisted laser desorption time of flight (MALD-TOF) ionization mass spectrometry, TdI-1 was found to have an unusally large mol. wt for a scorpion toxin, close to 48,000. The N-terminal sequence of the first 23 residues of TdI-1 was also determined. The fragment differs from the N-terminal sequences of all 140 peptidic scorpion toxins found in the SWISSPROT and PIR databases using the search engine of the felix.EMBL-Heidelberg.de computer (European Molecular Biology Laboratory, Heidelberg, Germany.

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