I'll be there for you: The effects of exercise engagement on social support provision within undergraduate students' personal networks.

Objective: To use social network analysis to examine exercise participation relative to health and wellness support provision within students' networks. Participants: 513 undergraduates from a large private university completed online surveys. Methods: Multilevel modeling assessed exercise engagement at the individual and dyadic level and support provision from network members. Results: More support was perceived by first and second-year students and individuals who reported more exercise engagement. Significant others, roommates, siblings, female network members, and those who exercised often provided greater support. Greater support was reported when both the participant and their social tie were involved in the campus group-exercise program. Conclusion: This study suggests individual and dyadic-level exercise was related to undergraduates feeling more supported. Findings support campus group exercise programs as opportunities to create reciprocal supportive ties for college students. Future research could further explore ways exercise and social support, particularly in group settings, affect health and well-being.

Assessment of university policies for service animals and emotional support animals.

OBJECTIVE: Assess administrative responsibilities and experiential effects of emotional support animal (ESA) and service animal (SA) policies on college campuses. PARTICIPANTS: Students at two four-year universities participated in an emotional support animals and service animals survey. Selected students and professional personnel participated in interviews and focus groups. METHODS: This mixed-methods study included quantitative survey data from 1,363 students, qualitative individual interviews (3) and a focus group (1) regarding emotional support animal (ESA) and service animal (SA). RESULTS: Seventy-one students reported having ESAs, 18 had SAs. Barriers for ESAs on campus included no ESAs outside of dorms, while SA-owners reported fewer barriers. University administrators followed federal guidelines for SAs but lacked clear guidelines for ESAs. Qualitative themes included lack of awareness, education, support for SA, and ESA accommodations. CONCLUSIONS: ESA and SA accommodations continue to rise, on university campuses. Clear guidelines and implementation processes are imperative for future improvements.

Egocentric network composition and structure relative to violence victimization among a sample of college students.

ObjectiveTo use egocentric network analysis to understand how composition and structure of egonetworks relate to violence victimization among college students. Participants: 697 students from a large southeastern university completed online surveys. Methods: Hierarchical logistic regression analyses assessed the relationship between egocentric network variables and a history of violence victimization. Results: Being connected to others with a history of violence victimization increased a student's odds of indicating their own history of physical, emotional, and sexual violence victimization. Having less dense egonetworks was related to sexual violence victimization, while being connected to less people of the same gender was related to emotional violence victimization. Conclusion: The way college students' networks are composed and structured could help in understanding violence victimization in this population, and should be considered in prevention and reactionary efforts on campuses. These findings add to the current literature largely focused on individual-level risk factors related to violence.

Social networks, group exercise, and anxiety among college students.

OBJECTIVE: This study aimed to evaluate the relationship between group exercise membership, social network characteristics, and general state anxiety in a sample of college students. Participants: 490 undergraduates from a private university in the southern US participated in the study. Methods: An egocentric network analysis was conducted to test whether demographic variables, leisure-time physical activity, group exercise membership, flourishing scores, and network variables were related to anxiety. Results: Regression analyses (R2 = .174, F = 7.650, p < .0001) suggest group exercise membership (ß = -.105, p = .034) and flourishing scores (ß = -.342, p < .0001) were related to lower anxiety scores, while being a racial/ethnic minority (ß = .094, p = .036), and having personal networks composed of more people who exercise often (ß = .100, p = .025), were related to higher anxiety scores in this sample. Conclusions: Findings suggest a connection between group exercise membership, activity habits of peers, and anxiety. Encouraging group exercise participation could be an effective way of combating anxiety for college students.

Five-year results of the complete versus culprit vessel percutaneous coronary intervention in multivessel disease using drug-eluting stents II (CORRECT II) study: a prospective, randomised controlled trial.

OBJECTIVES/BACKGROUND: In patients with multivessel coronary artery disease (MVD) the decision whether to treat a single culprit vessel or to perform multivessel revascularisation may be challenging. The purpose of this study was to evaluate the long-term outcome of multivessel percutaneous coronary intervention (MV-PCI) versus culprit vessel only (CV-PCI) in patients with stable coronary artery disease or non-ST elevation acute coronary syndrome. METHODS: In this dual-centre, prospective, randomised study a total 215 patients with MVD were randomly assigned to MV-PCI or CV-PCI. The primary endpoint was the occurrence of major adverse cardiac events (MACE) including death, myocardial infarction (MI), and repeat revascularisation. Secondary endpoints were the combined endpoint of death or MI, the individual components of the primary endpoint, and the occurrence of stent thrombosis. Patients were followed up to 5 years after enrolment. RESULTS: The occurrence of the primary endpoint was similar at 28% versus 31% in the MV-PCI and CV-PCI group, respectively (hazard ratio [HR] 0.87, 95% confidence interval [CI]: 0.53-1.44, p = 0.59). The rate of repeat revascularisation was 15% versus 24% (HR 0.59, 95% CI 0.32 to 1.11, p = 0.11), whereas definite or probable stent thrombosis occurred in 2% versus 0% (p = 0.44). CONCLUSIONS: In this randomised study comparing the strategies for MV-PCI and CV-PCI in patients with MVD, no difference was found in the occurrence of MACE after 5 years. We observed a numerically higher rate of death or MI and a lower rate of repeat revascularisation after MV-PCI, although these findings were not statistically significant.

Impact of percutaneous coronary intervention timing on 5-year outcome in patients with non-ST-segment elevation acute coronary syndromes. The 'wait a day' approach might be safer.

BACKGROUND: The OPTIMA trial was a randomised multicentre trial exploring the influence of the timing of percutaneous coronary intervention (PCI) on patient outcomes in an intermediate to high risk non-ST-elevation acute coronary syndrome (NSTE-ACS) population. In order to decide the best treatment strategy for patients presenting with NSTE-ACS, long-term outcomes are essential. METHODS: Five-year follow-up data from 133 of the 142 patients could be retrieved (94 %). The primary endpoint was a composite of death and spontaneous myocardial infarction (MI). Spontaneous MI was defined as MI occurring more than 30 days after randomisation. Secondary endpoints were the individual outcomes of death, spontaneous MI or re-PCI. RESULTS: No significant difference with respect to the primary endpoint was observed (17.8 vs. 10.1 %; HR 1.55, 95 % CI: 0.73-4.22, p = 0.21). There was no significant difference in mortality rate. However, spontaneous MI was significantly more common in the group receiving immediate PCI (11.0 vs. 1.4 %; HR 4.46, 95 % CI: 1.21-16.50, p = 0.02). We did not find a significant difference between the groups with respect to re-PCI rate. CONCLUSION: There was no difference in the composite of death and spontaneous MI. The trial suggests an increased long-term risk of spontaneous MI for patients treated with immediate PCI.

An Integrated X-Ray/Optical Tomography System for Pre-clinical Radiation Research.

The current Small Animal Radiation Research Platform (SARRP) is poor for localizing small soft tissue targets for irradiation or tumor models growing in a soft tissue environment. Therefore, an imaging method complementary to x-ray CT is required to localize the soft tissue target's Center of Mass (CoM) to within 1 mm. In this paper, we report the development of an integrated x-ray/bioluminescence imaging/tomography (BLI/BLT) system to provide a pre-clinical, high resolution irradiation system. This system can be used to study radiation effects in small animals under the conebeam computed tomography (CBCT) imaging guidance by adding the bioluminescence imaging (BLI) system as a standalone system which can also be docked onto the SARRP. The proposed system integrates two robotic rotating stages and an x-ray source rated at maximum 130 kVp and having a small variable focal spot. A high performance and low noise CCD camera mounted in a light-tight housing along with an optical filter assembly is used for multi-wavelength BL tomography. A three-mirror arrangement is implemented to eliminate the need of rotating the CCD camera for acquiring multiple views. The mirror system is attached to a motorized stage to capture images in angles between 0-90° (for the standalone system). Camera and CBCT calibration are accomplished.

Immediate versus deferred coronary angioplasty in non-ST-segment elevation acute coronary syndromes.

BACKGROUND: The field of acute coronary syndromes is characterised by an increasing tendency towards early invasive catheter-based diagnostics and therapeutics-a practice based on observational and retrospective data. OBJECTIVE: To compare immediate versus deferred angioplasty in patients with non-ST-segment elevation acute coronary syndromes (NSTE-ACS) METHODS: A randomised, prospective multicentre trial was performed in patients admitted with NSTE-ACS, eligible for percutaneous coronary intervention (PCI). Interim analysis was performed after enrolment of 251 patients; PCI was appropriate in 142 patients. These patients were randomised to immediate PCI (n = 73) or deferred PCI (24-48 h) (n = 69). Patients received protocol-driven glycoprotein IIb/IIIa blockers, aspirin and clopidogrel. The primary end point was a composite of death, non-fatal myocardial infarction (MI) or unplanned revascularisation, at 30 days. After hospital discharge outpatient follow-up was performed at 30 days and 6 months. RESULTS: The incidence at 30 days of the primary end point was 60% in the group receiving immediate PCI and 39% in the group receiving deferred PCI (relative risk (RR) = 1.5, 95% CI 1.09 to 2.15; p = 0.004). No deaths occurred in either group. MI was significantly more common in the group receiving immediate PCI (60% vs 38%, RR = 1.6, 95% CI 1.12 to 2.28, p = 0.005). Unplanned revascularisation was similar in both groups. The observed difference was preserved over 6-months' follow-up. CONCLUSIONS: Immediate PCI was associated with an increased rate of MI in comparison with a 24-48 h deferred strategy, despite aggressive antithrombotic treatment. The results suggest that PCI for high-risk patients with non-refractory NSTE-ACS should be delayed for at least 24 h after hospital admission. TRIAL REGISTRATION NUMBER: ISRCTN80874637.

The use of magnetic field effects on photosensitizer luminescence as a novel probe for optical monitoring of oxygen in photodynamic therapy.

The effect of a magnetic field on the steady-state and time-resolved optical emission of a custom fullerene-linked photosensitizer (PS) in liposome cell phantoms was studied at various oxygen concentrations (0.19-190 microM). Zeeman splitting of the triplet state and hyperfine coupling, which control intersystem crossing between singlet and triplet states, are altered in the presence of low magnetic fields (B < 320 mT), perturbing the luminescence intensity and lifetime as compared to the triplet state at B = 0. Measurements of the luminescence intensity and lifetime were performed using a time-domain apparatus integrated with a magnet. We propose that by probing magnet-affected optical emissions, one can monitor the state of oxygenation throughout the course of photodynamic therapy. Since the magnetic field effect (MFE) operates primarily by affecting the radical ion pairs related to type I photodynamic action, the enhancement or suppression of the MFE can be used as a measure of the dynamic equilibrium between the type I and II photodynamic pathways. The unique photo-initiated charge-transfer properties of the PS used in this study allow it to serve as both cytotoxic agent and oxygen probe that can provide in situ dosimetric information at close to real time.

Bioluminescence imaging of point sources implanted in small animals post mortem: evaluation of a method for estimating source strength and depth.

The performance of a simple approach for the in vivo reconstruction of bioluminescent point sources in small animals was evaluated. The method uses the diffusion approximation as a forward model of light propagation from a point source in a homogeneous tissue to find the source depth and power. The optical properties of the tissue are estimated from reflectance images obtained at the same location on the animal. It was possible to localize point sources implanted in mice, 2-8 mm deep, to within 1 mm. The same performance was achieved for sources implanted in rat abdomens when the effects of tissue surface curvature were eliminated. The source power was reconstructed within a factor of 2 of the true power for the given range of depths, even though the apparent brightness of the source varied by several orders of magnitude. The study also showed that reconstructions using optical properties measured in situ were superior to those based on data in the literature.

Quantification of bioluminescence images of point source objects using diffusion theory models.

A simple approach for estimating the location and power of a bioluminescent point source inside tissue is reported. The strategy consists of using a diffuse reflectance image at the emission wavelength to determine the optical properties of the tissue. Following this, bioluminescence images are modelled using a single point source and the optical properties from the reflectance image, and the depth and power are iteratively adjusted to find the best agreement with the experimental image. The forward models for light propagation are based on the diffusion approximation, with appropriate boundary conditions. The method was tested using Monte Carlo simulations, Intralipid tissue-simulating phantoms and ex vivo chicken muscle. Monte Carlo data showed that depth could be recovered within 6% for depth 4-12 mm, and the corresponding relative source power within 12%. In Intralipid, the depth could be estimated within 8% for depth 4-12 mm, and the relative source power, within 20%. For ex vivo tissue samples, source depths of 4.5 and 10 mm and their relative powers were correctly identified.

Coronary air embolism treated with aspiration catheter.

Coronary air embolism remains a recognised complication of coronary catheterisation despite a strong emphasis on prevention. Current treatment consists of supportive measures with 100% oxygen and analgesia. Recent case reports describe the use of mechanical treatments aimed at dispersing or removing the air embolus with variable success. A case of coronary air embolism causing an acute coronary syndrome is described that was definitively treated with an aspiration system. The effectiveness of the aspiration system in the distal section of an obtuse marginal artery indicates that such dedicated aspiration systems may prove useful in the standard treatment of air embolism.

Singlet oxygen luminescence as an in vivo photodynamic therapy dose metric: validation in normal mouse skin with topical amino-levulinic acid.

Although singlet oxygen ((1)O(2)) has long been proposed as the primary reactive oxygen species in photodynamic therapy (PDT), it has only recently been possible to detect it in biological systems by its luminescence at 1270 nm. Having previously demonstrated this in vitro and in vivo, we showed that cell survival was strongly correlated to the (1)O(2) luminescence in cell suspensions over a wide range of treatment parameters. Here, we extend this to test the hypothesis that the photobiological response in vivo is also correlated with (1)O(2) generation, independent of individual treatment parameters. The normal skin of SKH1-HR hairless mice was sensitised with 20% amino-levulinic acid-induced protoporophyrin IX and exposed to 5, 11, 22 or 50 J cm(-2) of pulsed 523 nm light at 50 mW cm(-2), or to 50 J cm(-2) at 15 or 150 mW cm(-2). (1)O(2) luminescence was measured during treatment and the photodynamic response of the skin was scored daily for 2 weeks after treatment. As observed by other authors, a strong irradiance dependence of the PDT effect was observed. However, in all cases the responses increased with the (1)O(2) luminescence, independent of the irradiance, demonstrating for the first time in vivo an unequivocal mechanistic link between (1)O(2) generation and photobiological response.

Experimental verification of the effect of refractive index mismatch on the light fluence in a turbid medium.

Diffusion theory is often used to model the transport of light within tissue. It can be used to calculate the light fluence rate in tissue, for example, during photodynamic therapy, or to measure the absorption and scattering properties of tissue. For both of these applications, the influence of the interface between the tissue and the exterior medium on the fluence rate inside the tissue must be known in order to make accurate calculations. We present an experimental investigation of the effect of the refractive index mismatch at the tissue interface on the internal light fluence rate and on the spatially resolved diffuse reflectance as the boundary conditions of the tissue/external medium are changed. The effects of changing the relative refractive index at the boundary are compared to predictions of diffusion theory. The effect of the refractive index mismatch is predicted correctly by diffusion theory.

A diffusion theory model of spatially resolved fluorescence from depth-dependent fluorophore concentrations.

A photon diffusion model has been developed to calculate the steady-state spatially resolved fluorescence from pencil beam excitation in layered tissue. The model allows the calculation of both the excitation reflectance and the fluorescence escape for an arbitrary continuous depth distribution of tissue optical properties and fluorophore concentration. The validity of this model was verified by comparison with Monte Carlo simulations and experimental measurements using phantoms with tissue-like optical properties. The potential usefulness of the spatially resolved fluorescence was explored using the model and simulations of realistic drug distributions. It was shown that using this technique it may be possible to quantify the diffusion of a topically administered drug into the skin, or the photobleaching of a sensitizer during photodynamic therapy.

Determination of the optical properties of two-layer turbid media by use of a frequency-domain hybrid monte carlo diffusion model.

The general two-layer inverse problem in biomedical photon migration is to estimate the absorption and scattering coefficients of each layer as well as the top-layer thickness. We attempted to solve this problem, using experimental and simulated spatially resolved frequency-domain (FD) reflectance for optical properties typical of skin overlying muscle or skin overlying fat in the near infrared. Two forward models of light propagation were used: a two-layer diffusion solution [Appl. Opt. 37, 779 (1998)] and a hybrid Monte Carlo (MC) diffusion model [Appl. Opt. 37, 7401 (1998)]. MC-simulated FD reflectance data were fitted as relative measurements to the hybrid and the pure diffusion models. It was found that the hybrid model could determine all the optical properties of the two-layer media studied to ~5%. Also, the same accuracy could be achieved by means of fitting MC-simulated cw reflectance data as absolute measurements, but fitting them as relative ones is an ill-posed problem. In contrast, two-layer diffusion could not retrieve the top-layer optical properties as accurately for FD data and was ill-posed for both relative and absolute cw data. The hybrid and the pure diffusion models were also fitted to experimental FD reflectance measurements from two-layer tissue-simulating phantoms representative of skin-on-fat and skin-on-muscle baseline optical properties. Both the hybrid and the diffusion models could determine the optical properties of the lower layer. The hybrid model demonstrated its potential to retrieve quantitatively the transport scattering coefficient of skin (the upper layer), which was not possible with the pure diffusion model. Systematic discrepancies between model and experiment may compromise the accuracy of the deduced top-layer optical properties. Identifying and eliminating such discrepancies is critical to practical application of the method.

Noninvasive measurement of fluorophore concentration in turbid media with a simple fluorescence /reflectance ratio technique.

Measurement of the concentration of fluorescent compounds in turbid media is difficult because the absorption and multiple scattering of excitation and emission of light has a large effect on the detected fluorescence. For surface measurements with optical fibers we demonstrate by experiments and numerical simulation that this effect can be minimized by measurement of the fluorescence at one source-detector distance, the diffusely reflected excitation light at a second distance, and with the ratio of these two signals as an indicator of fluorophore concentration. For optical properties typical of soft tissue in the red and the near infrared the optimum performance is obtained by measurement of fluorescence at 0.65 mm and reflectance at 1.35 mm. This choice reduces the rms error in fluorophore concentration to 14.6% over a wide range of absorption and scattering coefficients.

Anisotropy of light propagation in human skin.

Using spatially resolved, steady state diffuse reflectometry, a directional dependence was found in the propagation of visible and near infrared light through human skin in vivo. The skin's reduced scattering coefficient mu(s)' varies by up to a factor of two between different directions of propagation at the same position. This anisotropy is believed to be caused by the preferential orientation of collagen fibres in the dermis, as described by Langer's skin tension lines. Monte Carlo simulations that examine the effect of partial collagen fibre orientation support this hypothesis. The observation has consequences for non-invasive diagnostic methods relying on skin optical properties, and it could be used non-invasively to determine the direction of lines of cleavage in order to minimize scars due to surgical incisions.

Monte carlo diffusion hybrid model for photon migration in a two-layer turbid medium in the frequency domain.

We propose a hybrid Monte Carlo (MC) diffusion model for calculating the spatially resolved reflectance amplitude and phase delay resulting from an intensity-modulated pencil beam vertically incident on a two-layer turbid medium. The model combines the accuracy of MC at radial distances near the incident beam with the computational efficiency afforded by a diffusion calculation at further distances. This results in a single forward calculation several hundred times faster than pure MC, depending primarily on model parameters. Model predictions are compared with MC data for two cases that span the extremes of physiologically relevant optical properties: skin overlying fat and skin overlying muscle, both in the presence of an exogenous absorber. It is shown that good agreement can be achieved for radial distances from 0.5 to 20 mm in both cases. However, in the skin-on-muscle case the choice of model parameters and the definition of the diffusion coefficient can lead to some interesting discrepancies.

Comparison of the in vivo photodynamic threshold dose for photofrin, mono- and tetrasulfonated aluminum phthalocyanine using a rat liver model.

The photodynamic threshold dose in normal rat liver was determined from the measured depth of necrosis following surface irradiation. The threshold was determined for the photosensitizing drugs Photofrin and monosulfonated aluminum chlorophthalocyanine, AlPcS1, at 24 h postinjection and was found to be (3.4 x/divided by 1.3) x 10(18) and (8.2 x/divided by 1.5) x 10(18) photons cm-3, respectively, compared with the previously reported value of (38 +/- 2) x 10(18) photons cm-3 for the tri/tetrasulfonated phthalocyanine, AlPcS4. These values were independent of drug concentration or total light fluence. For all three drugs the depth of tissue necrosis decreased as the time between drug and light administration increased from 10 min to 72 h. This decrease can be attributed both to the change in the tissue drug concentration as well as to changes in the efficiency of photodynamic therapy for producing tissue damage, related to the photodynamic necrosis threshold. The threshold values for all three photosensitizers were lowest at 10 min post injection: (1.4 x/divided by 1.4) x 10(18), (1.6 x/divided by 1.3) x 10(18) and (23 x/divided by 1.3) x 10(18) photons cm-3 for Photofrin, AlPcS1 and AlPcS4, respectively. The changes in necrosis threshold with time may be due to an initial change from entirely vascular to a combination of vascular and cellular damage, with later redistribution of the photosensitizer to targets at the subcellular level.