Proper inhaler use is critical to asthma management, but many children and youth do not use their inhalers correctly. School nurses are ideally positioned and have an important role in assessing the ...inhaler technique and knowledge regarding its use among students. This article discusses common student errors with inhaler technique, along with knowledge deficits surrounding use of asthma inhalers. A tool for assessing inhaler use is provided, in addition to suggestions for how to assist students with improved inhaler technique. By assessing inhaler technique and knowledge early in the school year, school nurses proactively assist in improved student management of their asthma.
A study on clonal growth in Chinese hamster ovary (CHO) cells was conducted after exposure to optical trapping wavelengths using Nd:YAG (1064 nm) and tunable titanium-sapphire (700–990 nm) laser ...microbeam optical traps. The nuclei of cells were exposed to optical trapping forces at various wavelengths, power densities, and durations of exposure. Clonal growth generally decreased as the power density and the duration of laser exposure increased. A wavelength dependence of clonal growth was observed, with maximum clonability at 950–990 nm and least clonability at 740–760 nm and 900 nm. Moreover, the most commonly used trapping wavelength, 1064 nm from the Nd:YAG laser, strongly reduced clonability, depending upon the power density and exposure time. The present study demonstrates that a variety of optical parameters must be considered when applying optical traps to the study of biological problems, especially when survival and viability are important factors. The ability of the optical trap to alter either the structure or biochemistry of the process being probed with the trapping beam must be seriously considered when interpreting experimental results.
The antibacterial photodynamic effects of uncharged (o-tetrahydroxyphenyl porphine THPP, m-THPP and p-THPP), cationic (5,10,15,20-tetra4-N-methylpyridylporphine TMPyP) and anionic ...(5,10,15,20-tetra4-sulfonatophenyl porphine TPPS4) porphines on Staphylococcus aureus and Escherichia coli bacteria inactivation were examined. The results show that uncharged porphines provoked antibacterial photodynamic activity on S. aureus, and also on E. coli in the presence of the membrane-disorganizing peptide polymixin B nonapeptide (PMNP). The TMPyP compound was highly photoactive toward gram-positive bacteria but only marginally effective on gram-negative cells, whereas TPPS4 showed no activity on either gram-positive or gram-negative bacteria. The photoactivity of TMPyP is due to the electrostatic attraction between the positively charged sensitizer molecule and the negatively charged membrane of the gram-positive target cells. For TPPS4, the inactivity toward gram-positive bacteria is due to electrostatic repulsion between the charged sensitizer molecule and the cell membrane. For gram-negative bacteria, the inactivity is conceivably due to preferential (electrostatic) binding to the positively charged PMNP, which is an adjuvant for membrane disorganization, but has no effect on cell viability. For hydrophobic sensitizers, the photoactivity depends on the state of aggregation. The extent of deaggregation of the different THPP isomers was determined by fluorescence measurements of bound sensitizers and could be positively correlated with their photoinactivation capacity. We conclude that the structure-activity relationships of these porphines are affected by their net charge and by aggregation.
Past research on cognitive dissonance indicated that people from independent (e.g. European-American) and interdependent (e.g. East-Asian) cultural backgrounds show different patterns of choice ...justification: whereas choice made for oneself affirms the independent view of the self, choice made for close others affirms the interdependent view of the self. We hypothesized that interpersonal choice considerations may be temporally accessible even among habitually independent European-Americans. The present research provides the first experimental evidence that choice justification varies as a function of both subliminal affiliation priming and the target of choice (self vs. close others). Results from three studies indicate that subliminal priming of affiliation increases justification of a choice European-Americans made for a close other, while decreasing justification of a choice made for the self. Implications for theories related to cognitive dissonance, subliminal processing and cultural meaning systems are discussed.
► We subliminally prime people with affiliation vs. neutral words. ► Participants chose between similarly attractive gifts. ► We examine if justifying a choice depends on whether it was made for self or others ► After priming, European-Americans justified self-choices less than other-choices.
Photodynamic efficacy of four tetrakis(methoxyethyl)porphycene (TMPn) derivatives encapsulated in liposomes, was studied in vitro and in vivo. Fluorescence and absorption measurements were used to ...determine aggregation in dipalmitoyl phosphatidylcholine (DPPC) liposomes; no spectral changes were found when dissolving in an organic solution or in an aqueous dispersion of DPPC liposomes. This indicates that the porphycenes were located in the lipophilic bilayer of the liposomes. Fluorescence quenching experiments with I
− showed, specifically, that porphycenes located in the liposome bilayer at various depths, according to the hydrophilicity of the porphycene side chains. Doseresponse relations were established: increasing porphycene concentration or light dose enhanced the damage proportionally. In cultured MDCK cells, photodynamic damage was in accordance with location: a porphycene ‘buried’ inside the bilayer did not cause damage to the cell culture. PDT efficacy was tested also in vivo by the damage to blood vessels of the chorioallantoic membrane (CAM) of the fertilized chick embryo. Unlike in the in vitro case, the porphycene ‘buried’ inside the bilayer did cause significant photodynamic damage in vivo. This difference suggests that in vitro photodynamic action follows contact-mediated sensitizer transfer to cell membranes from liposomes, which remain distinct from cells, whereas in vivo the photosensitizer is delivered to tissue via fusion of liposomes with endothelial cell membranes.
Programs to facilitate professional eye exams after failed school vision screenings often are based on the assumption that funding and access to services are major obstacles to care. Despite such ...programs, many children do not receive professional exams. The purpose of this study was to identify additional barriers to follow-up eye care. School nurses in an urban, mid-western public school district identified elementary school students who had not received follow-up eye exams after failed school vision screenings. Parents of these students were interviewed during the summer to determine financial, logistical, social/family, and perceptual barriers to care. Family issues, parental perceptions of vision problems, and difficulty planning ahead were found to be significant factors. Strategies to increase follow-up compliance and recommendations for overcoming barriers to care were also identified.
Photodynamically induced oxygen depletion has been measured in an Ehrlich ascites mouse tumor cell line using a Clark-type electrode. Cells are loaded with aluminum phthalocyanines, sulfonated to ...different degrees (AlPcS
n
,
n = 0,2,3,4) and consisting of various isomeric species. Different cell lines and incubation procedures are used in order to investigate the cellular uptake mechanism. Uptake (in units of molecules/cell), post-irradiation redistribution and AlPcS
n
photodegradation are measured using spectroscopic techniques. For a given sensitizer, the oxygen depletion rate per cell increases sublinearly with uptake and superlinearly with cell density. In order to compare oxygen depletion rates of different compounds, we have defined the biological quantum yield (BQY) as the number of oxygen molecules that disappear per absorbed photon. The BQY is independent of uptake and cell density; therefore, it denotes the intrinsic photoactivity of a sensitizer. Sensitizers with high BQY show efficient post-irradiation intracellular redistribution. Photodegradation during irradiation is similar for all sensitizers (20–30%).
Photodynamic therapy (PDT) has been described in terms of cellular and vascular effects. The precise mechanisms of cellular and vascular damage are still unknown. In this study, the photodynamic ...inactivation of endothelial cells in vitro and damage to the microvasculature in vivo by naturally occurring porphyrins (uroporphyrin III (UP), coproporphyrin III (CP) and protoporphyrin IX (PP)) were investigated. The chick chorioallantoic membrane model (CAM model) was used, which is convenient for the study of damage to the microcirculation induced by PDT. The hydrophilic porphyrins UP and CP exhibited low cytotoxicity towards endothelial cells. Only small amounts of UP and CP were taken up, resulting in weak inactivation after irradiation. In contrast, the more lipophilic PP showed a marked cytotoxicity. Considerable amounts of PP were accumulated in the cells, leading to pronounced inactivation after light exposure. For the three porphyrins, damage to the microvasculature was observed. The damage caused by the hydrophilic porphyrins UP and CP was strongly dependent on the drug and light dose. For vascular injury, the efficacy was graded as UP < CP < PP.
The ability to control the degree and spatial distribution of cooling in biological tissues during a thermally mediated therapeutic procedure would be useful for several biomedical applications of ...lasers. We present a theory based on the solution of the heat conduction equation that demonstrates the feasibility of selectively cooling biological tissues. Model predictions are compared with infrared thermal measurements of in vivo human skin in response to cooling by a cryogen spurt. The presence of a boundary layer, undergoing a liquid-vapour phase transition, is associated with a relatively large thermal convection coefficient (approximately 40 kW m-2 K-1), which gives rise to the observed surface temperature reductions (30-40 degrees C). The degree and the spatial-temporal distribution of cooling are shown to be directly related to the cryogen spurt duration.
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