Home About us Contact
|
Home About us Contact | ||
|
|
||
Light Treatment (light + treatment)
Selected AbstractsSafety of Lidocaine 15% and Prilocaine 5% Topical Ointment Used as Local Anesthesia for Intense Pulsed Light TreatmentDERMATOLOGIC SURGERY, Issue 7 2010J. ALASTAIR CARRUTHERS MD BACKGROUND Literature cautions against applying lidocaine 15%/prilocaine 5% over an area larger than 300 cm2. The area of the face, neck, and chest is 400 cm2 or greater. OBJECTIVE To investigate the safety of lidocaine 15%/prilocaine 5% topical anesthetic ointment used as anesthesia for intense pulsed light (IPL) treatment. METHODS AND MATERIALS Lidocaine 15%/prilocaine 5% ointment was applied to the face only (n=10) for 30 ± 15 minutes or to the face, neck, and chest (n=10) for a total of 60 ± 15 minutes before IPL. Blood lidocaine and prilocaine levels were measured. Adverse events were recorded. RESULTS For the entire cohort, blood was drawn 25.6 ± 6.6 minutes after IPL was completed. In the face only group, the mean lidocaine level was 0.122 ± 0.125 ,g/mL, and the mean prilocaine level was 0.048 ± 0.029 ,g/mL. In the face, neck, and chest group, the mean lidocaine level was 0.272 ± 0.208 ,g/mL, and the mean prilocaine level was 0.087 ± 0.060 ,g/mL. No adverse events related to systemic toxicity were observed or reported to the nurse. At the 24-hour follow-up, no subject reported symptoms of systemic toxicity after leaving the clinic. CONCLUSION Under the conditions of this study, topical lidocaine 15%/prilocaine 5% produces low levels of systemic absorption. The authors have indicated no significant interest with commercial supporters. [source] Papular Hyperplasia of the Follicular Infundibulum After Intense Pulsed Light Treatment for PhotoagingDERMATOLOGIC SURGERY, Issue 12 2009MARIA LETICIA CINTRA MD First page of article [source] Decision Factors and the Recognition of Medical Specialty in Patients Receiving Cosmetic Laser and Intense Pulsed Light TreatmentDERMATOLOGIC SURGERY, Issue 12 2007TIEN-YI TZUNG MD BACKGROUND In addition to dermatologists and plastic surgeons, physicians of other medical specialties also provide cosmetic laser and light treatment. OBJECTIVE This study aimed to determine the major decision factors in patients who received cosmetic laser or intense pulsed light treatment and how they perceived different medical specialties in providing such services. METHODS The method of factor analysis was adopted to extract the common characteristics (major decision factors) from a list of 17 items patients would regard as important when they planned to receive laser and intense pulsed light treatment. In addition, the level of recognition of different medical specialties in cosmetic patients was indirectly forecast using an analytic hierarchy process. RESULTS Medical competence (0.3296) was the most important decision factor, followed by recommendation (0.2198), friendliness (0.1350), cost (0.1307), complete service (0.0984), and the physical attributes of the physician (0.0865). Dermatologists and plastic surgeons outscored cosmetic practitioners in five factors except for cost, in which the plastic surgeons were weakest. CONCLUSION Medical competence and recommendation are the core issues for cosmetic patients. Dermatologists and plastic surgeons gain better overall recognition than physicians of other medical specialties in cosmetic patients. [source] Intense Pulsed Light Treatment of Photoaged Facial SkinDERMATOLOGIC SURGERY, Issue 8 2004Douglas E. Kligman MD Background. It has been reported that intense pulsed light is efficacious for rejuvenation of photoaged skin, specifically the improvement of appearance of telangiectases and solar lentigines. Objective. The objective was to define the treatment variables for photodamaged facial skin using a newer intense pulsed light system. Methods. Twenty-three female subjects received three treatments using double-stacked pulses with fluences of 24 and 30 J/cm2. Response to treatment was evaluated using digital photography. Three signs of photoaging were evaluated: surface texture/roughness, mottled hyperpigmentation, and erythema/telangiectases. Results. There was a shift in clinical grading from more to less severe on all three measures of photoaging. Conclusion. Intense pulsed light therapy was efficacious in ameliorating the clinical signs of photoaging. The device was well tolerated with minimal side effects. [source] Effect of Light Treatment on Sleep and Circadian Rhythms in Demented Nursing Home PatientsJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 2 2002Sonia Ancoli-Israel PhD First page of article [source] Light regulation of retinal dopamine that is independent of melanopsin phototransductionEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 4 2009M. A. Cameron Abstract Light-dependent release of dopamine (DA) in the retina is an important component of light-adaptation mechanisms. Melanopsin-containing inner retinal photoreceptors have been shown to make physical contacts with DA amacrine cells, and have been implicated in the regulation of the local retinal environment in both physiological and anatomical studies. Here we determined whether they contribute to photic regulation of DA in the retina as assayed by the ratio of DA with its primary metabolite, 3,4-dihydroxyphenylacetic acid (DOPAC), and by c-fos induction in tyrosine hydroxylase (TH)-labelled DA amacrine cells. Light treatment (,0.7 log W/m2 for 90 min) resulted in a substantial increase in DA release (as revealed by an increase in the DOPAC : DA ratio), as well as widespread induction of nuclear c-fos in DA amacrine cells in wild-type mice and in mice lacking melanopsin (Opn4,/,). Light-induced DA release was also retained in mice lacking rod phototransduction (Gnat1,/,), although the magnitude of this response was substantially reduced compared with wild-types, as was the incidence of light-dependent nuclear c-fos in DAergic amacrines. By contrast, the DAergic system of mice lacking both rods and cones (rd/rd cl) showed no detectable light response. Our data suggest that light regulation of DA, a pivotal retinal neuromodulator, originates primarily with rods and cones, and that melanopsin is neither necessary nor sufficient for this photoresponse. [source] Decision Factors and the Recognition of Medical Specialty in Patients Receiving Cosmetic Laser and Intense Pulsed Light TreatmentDERMATOLOGIC SURGERY, Issue 12 2007TIEN-YI TZUNG MD BACKGROUND In addition to dermatologists and plastic surgeons, physicians of other medical specialties also provide cosmetic laser and light treatment. OBJECTIVE This study aimed to determine the major decision factors in patients who received cosmetic laser or intense pulsed light treatment and how they perceived different medical specialties in providing such services. METHODS The method of factor analysis was adopted to extract the common characteristics (major decision factors) from a list of 17 items patients would regard as important when they planned to receive laser and intense pulsed light treatment. In addition, the level of recognition of different medical specialties in cosmetic patients was indirectly forecast using an analytic hierarchy process. RESULTS Medical competence (0.3296) was the most important decision factor, followed by recommendation (0.2198), friendliness (0.1350), cost (0.1307), complete service (0.0984), and the physical attributes of the physician (0.0865). Dermatologists and plastic surgeons outscored cosmetic practitioners in five factors except for cost, in which the plastic surgeons were weakest. CONCLUSION Medical competence and recommendation are the core issues for cosmetic patients. Dermatologists and plastic surgeons gain better overall recognition than physicians of other medical specialties in cosmetic patients. [source] Lux vs. wavelength in light treatment of Seasonal Affective DisorderACTA PSYCHIATRICA SCANDINAVICA, Issue 3 2009J. L. Anderson Objective:, Published dosing guidelines for treatment of Seasonal Affective Disorder (SAD) refer to photopic lux, which is not appropriate for short-wavelength light. Short wavelengths are most potent for many non-visual responses to light. If SAD therapy were similarly mediated, standards utilizing lux risk overestimating necessary dose. We investigated antidepressant responses to light using two light-emitting diode (LED) sources, each emitting substantial short-wavelength light, but <2500 lux. Method:, A randomized, double-blind trial investigated 3-week 45 min/day out-patient treatment with blue-appearing (goLITE®) or blue-enriched white-appearing light in 18 moderately-depressed adults (12F, 49.1 ± 9.5 years). Equivalent numbers of photons within the short-wavelength range were emitted, but the white source emitted twice as many photons overall and seven-fold more lux. Results:, Depression ratings (SIGH-ADS; http://www.cet.org) decrease averaged 82% (SD = 17%) from baseline (P < 0.0001) in both white- and blue-light groups. Both sources were well tolerated. Conclusion:, Short-wavelength LED light sources may be effective in SAD treatment at fewer lux than traditional fluorescent sources. [source] Time course analysis of gene expression during light-induced photoreceptor cell death and regeneration in albino zebrafishDEVELOPMENTAL NEUROBIOLOGY, Issue 8 2007Sean C. Kassen Abstract Constant intense light causes apoptosis of rod and cone photoreceptors in adult albino zebrafish. The photoreceptors subsequently regenerate from proliferating inner nuclear layer (INL) progenitor cells that migrate to the outer nuclear layer (ONL) and differentiate into rods and cones. To identify gene expression changes during this photoreceptor regeneration response, a microarray analysis was performed at five time points during the light treatment. The time course included an early time point during photoreceptor death (16 h), later time points during progenitor cell proliferation and migration (31, 51, and 68 h) and a 96 h time point, which likely corresponds to the initial photoreceptor differentiation. Mean expression values for each gene were calculated at each time point relative to the control (0 h light exposure) and statistical analysis by one-way ANOVA identified 4567 genes exhibiting significant changes in gene expression along the time course. The genes within this data set were clustered based on their temporal expression patterns and proposed functions. Quantitative real-time PCR validated the microarray expression profiles for selected genes, including stat3 whose expression increased markedly during the light exposure. Based on immunoblots, both total and activated Stat3 protein expression also increased during the light treatment. Immunolocalization of Stat3 on retinal tissue sections demonstrated increased expression in photoreceptors and Müller glia by 16 h of light exposure. Some of the Stat3-positive Müller cells expressed PCNA at 31 h, suggesting that Stat3 may play a role in signaling a subset of Müller cells to proliferate during the regeneration response. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007. [source] SURVEY OF APPLE GROWING, HARVESTING, AND CIDER MANUFACTURING PRACTICES IN WISCONSIN: IMPLICATIONS FOR SAFETYJOURNAL OF FOOD SAFETY, Issue 2 2000HEIDI E. ULJAS ABSTRACT To evaluate the safety of current apple growing, harvesting and cider manufacturing practices in Wisconsin, cider manufacturers were contacted in a three-phase survey. Results revealed that seasonal, small-scale production was characteristic of the industry. Most cider mills produced less than 5,000 gal/year; only 6% produced more than 20,000 gal/year. Most cider makers used only tree picked apples (86%), inspected apples before washing (94%), washed (93%) and brushed (87%) apples, but only 16% of mills sanitized washed apples. Most mills (92%) sanitized cider making equipment after each use; however, only a few sanitized between custom pressing apples from different customers. Respondents reported that they strived to improve cider safety by pasteurization (43% of all cider), UV light treatment (4%), use of preservatives (30%), and HACCP (17%). For 31% of all cider, however, processors relied solely on refrigeration and/or freezing. These results show that most cider mills practice many steps believed to enhance cider safety, but results also identify procedures that must be addressed to further improve cider safety. [source] Energy Dissipation and Photoinhibition in Douglas-Fir Needles with a Fungal-Mediated Reduction in Photosynthetic RatesJOURNAL OF PHYTOPATHOLOGY, Issue 11-12 2002Daniel K. Manter Abstract The dissipation of absorbed light and potential for photooxidative damage was explored in Douglas-fir (Pseudotsuga menziesii ) seedlings with and without Phaeocryptopus gaeumannii infection. The presence of P. gaeumannii significantly reduced net CO2 assimilation rates from ca. 6 ,mol/m2/s to 1.5 ,mol/m2/s, without any significant impact on chloroplast pigments. The partitioning of absorbed light-energy to photochemistry or thermal dissipation was determined from chlorophyll fluorescence measurements. Maximum thermal dissipation for both control and infected needles was ca. 80%, consistent with the similar xanthophyll pool sizes in the two treatments. At high photosynthetic photon flux density (PPFD), when thermal dissipation was maximized, the lower photochemical utilization in infected needles resulted in greater amounts of excess absorbed light (ca. 20 and 10% for the infected and control needles, respectively). A second experiment, monitoring changes in photosystem II (PSII) efficiency (Fv/Fm) in response to a 1 h high light treatment (PPFD=2000 ,mol/m2/s) also suggests that infected needles absorb greater amounts of excess light. In this experiment, declines in Fv/Fm were 1.5 times greater in infected needles, despite the similar xanthophyll pool sizes. Furthermore, increases in minimum fluorescence (178 and 122% of initial values for the infected and control needles, respectively) suggest that the reduction in PSII efficiency is largely attributable to photooxidative damage. Finally, reductions in PSII efficiency under high light conditions provide a plausible explanation for the greater pathogenicity (e.g. premature needle abscission) of P. gaeumannii in sun-exposed foliage. [source] Effect of stimulation of endogenous melatonin secretion during constant light exposure on 6-sulphatoxymelatonin rhythmicity in ratsJOURNAL OF PINEAL RESEARCH, Issue 1 2000D.J. Kennaway When light is presented unexpectedly at night to rats, melatonin production and secretion is acutely inhibited and the time of onset of production on the subsequent night is altered. In a series of experiments, we examined the effects of 6,12 hr light (200 lux) at night on melatonin metabolite excretion (6-sulphatoxymelatonin, aMT.6S). During the light exposure, we administered isoproterenol to stimulate endogenous production of melatonin by the pineal gland to determine if replacement of melatonin would block any phase shifting effects of the light. Exposure to 6 hr of light either during the first or second half of the night suppressed aMT.6S excretion during the light treatment and delayed the onset of melatonin secretion by 3.7±0.6 and 2.5±0.6 hr, respectively, compared to a change of 0.5±0.1 hr in animals maintained in darkness. Twelve hours light exposure (i.e. one night of continuous light) suppressed aMT.6S excretion completely and resulted in a delay in the onset the next night of 2.1±0.7 hr. When propranolol (10 mg/kg) was administered at 2-hr intervals during darkness, aMT.6S excretion was suppressed throughout the night, but on the subsequent release into constant darkness the onset of excretion was not delayed (0.6±0.1 hr delay). Administration of isoproterenol (10 mg/kg) to animals in constant light, at the time of expected lights off (CT12), and 5 hr later (CT17) resulted in an increase in melatonin production and aMT.6S excretion that was similar in duration and amount to the control night. The stimulation of endogenous melatonin production failed to block the phase shifting effects of the light exposure and, in fact, appeared to potentiate the delay at least on the first night (4.2±0.9 hr). The timing of the release into constant darkness following the light treatment had an unexpected effect on melatonin production on the cycle after treatment. Thus, animals exposed to 12 hr light and released into darkness at the normal time of lights off as above had a delay of about 2 hr and excreted 71±18% of the aMT.6S excreted on a control night. Animals released into darkness at the expected time of lights on failed to excrete more than 20 pmol/hr (i.e. no onset of excretion could be determined) at any time on the first subjective night after light treatment, which was no different from the excretion during the light treatment. On the next subjective night, the onset was delayed as expected and the amount of aMT.6S produced was restored. Treatment with isoproterenol at CT12 and CT17 failed to affect either the amount of aMT.6S excreted on the first subjective night after light treatment or the phase delay on the second night after treatment. The failure to produce melatonin on the first subjective night after 12 hr light exposure and release into darkness at CTO was not due to failure at the level of the pineal gland since injection of isoproterenol at CT12 and CT17 on the first subjective night after light restored the normal amount of melatonin production. These results suggest that the absence of melatonin during light stimulation at night is not responsible for the phase delay in melatonin production and excretion on subsequent nights. The basis of the failure of the rats to commence melatonin production following 12 hr extended light exposure followed immediately by continuous darkness is not known. [source] Photobleaching, light-induced discolouration in red peppersJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 14 2006Ji Won Jung Abstract Red peppers dried in sunlight experience surface bleaching, centred near the calyx, on the face exposed to the light. In this study, bleaching mechanisms were studied under simulated irradiation conditions by placing pericarp discs in 2-(N -morpholino) ethane sulfonic acid (MES) and sucrose solution. The moisture content near the calyx of the pepper decreased more slowly than that on the apex side. In addition, pericarp discs incubated without MES/sucrose solution retained more carotenoids than those incubated with solution after 27 h of light treatment. Carotenoids in pericarp discs exposed to the light decreased rapidly over the incubation time, whereas in the dark they decreased slowly and remained higher in content. Changes in malondialdehyde (MDA) level and electrolyte leakage were not observed for pericarp incubation in the dark. A sharp increase in the level of MDA and a change in electrolyte leakage from discs exposed to the light occurred when carotenoids were exhausted. Carotenoid degradation was markedly suppressed by the addition of ascorbic acid. These results demonstrate that carotenoids in red pepper pericarp played a role in protecting cells and were subsequently degraded under intense light conditions. Copyright © 2006 Society of Chemical Industry [source] Effect of Visible Light on Normal and P23H-3 Transgenic Rat Retinas: Characterization of a Novel Retinoic Acid Derivative Present in the P23H-3 RetinaPHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 3 2006Todd Duncan ABSTRACT Transgenic rats with the P23H mutation in rhodopsin exhibit increased susceptibility to light damage, compared with normal animals. It is known that light-induced retinal damage requires repetitive bleaching of rhodopsin and that photoreceptor cell loss is by apoptosis; however, the underlying molecular mechanism(s) leading to photoreceptor cell death are still unknown. Photoproducts, such as all- trans retinal or other retinoid metabolites, released by the extensive bleaching of rhodopsin could lead to activation of degenerative processes, especially in animals genetically predisposed to retinal degenerations. Using wild-type and transgenic rats carrying the P23H opsin mutation, we evaluated the effects of acute intense visible light on retinoid content, type and distribution in ocular tissues. Rats were exposed to green light (480,590 nm) for 0, 5, 10, 30 and 120 min. Following light treatment, rats were sacrificed and neural retinas were dissected free of the retinal pigment epithelium. Retinoids were extracted from retinal tissues and then subjected to HPLC and mass spectral analysis. We found that the light exposure affected relative levels of retinoids in the neural retina and retinal pigment epithelium of wild-type and P23H rat eyes similarly. In the P23H rat retina but not the wild-type rat retina, we found a retinoic acid-like compound with an absorbance maximum of 357 nm and a mass of 304 daltons. Production of this retinoic acid-like compound in transgenic rats is influenced by the age of the animals and the duration of light exposure. It is possible that this unique retinoid may be involved in the process of light-induced retinal degeneration. [source] Antivascular Tumor Eradication by Hypericin-mediated Photodynamic Therapy,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 5 2002Bin Chen ABSTRACT Photodynamic therapy (PDT) with hypericin has been shown to inhibit tumor growth in different tumor models, and tumor vascular damage was suggested to be mainly responsible for the antitumoral effect. Here, we demonstrate tumor vascular damage and its consequence on local tumor control after hypericin-mediated PDT by using both short and long drug,light intervals. Radiation-induced fibrosarcoma-1 tumors were exposed to laser light at either 0.5 or 6 h after a 5 mg/kg dose of hypericin. Tumor perfusion was monitored by fluorescein dye,exclusion assay and by Hoechst 33342 staining of functional blood vessels. Significant reduction in tumor perfusion was found immediately after both PDT treatments. A complete arrest of vascular perfusion was detected by 15 h after the 0.5 h-interval PDT, whereas well-perfused areas could still be found at this time in tumors after the 6 h-interval PDT. A histological study confirmed that primary vascular damage was involved in both PDT treatments. Tumor cells appeared intact shortly after light treatment, degenerated at later hours and became extensively pycnotic at 24 h after the 0.5 h-interval PDT. PDT under this condition led to complete tumor cure. In contrast, significant numbers of viable tumor cells, especially at the tumor periphery, were found histologically at 24 h after the 6 h-interval PDT. No tumor cure was obtained when PDT was performed at this time. Our results strongly suggest that targeting the tumor vasculature by applying short drug,light interval PDT with hypericin might be a promising way to eradicate solid tumors. [source] Short- and long-term modulation of the lutein epoxide and violaxanthin cycles in two species of the Lauraceae: sweet bay laurel (Laurus nobilis L.) and avocado (Persea americana Mill.)PLANT BIOLOGY, Issue 3 2008R. Esteban Abstract Short- and long-term responses of the violaxanthin (V) and lutein epoxide (Lx) cycles were studied in two species of Lauraceae: sweet bay laurel (Laurus nobilis L.) and avocado (Persea americana L.). The Lx content exceeded the V content in shade leaves of both species. Both Lx and V were de-epoxidised on illumination, but only V was fully restored by epoxidation in low light. Violaxanthin was preferentially de-epoxidised in low light in L. nobilis. This suggests that Lx accumulates with leaf ageing, partly because its conversion to lutein is limited in shade. After exposure to strong light, shade leaves of avocado readjusted the total pools of ,- and ,-xanthophyll cycles by de novo synthesis of antheraxanthin, zeaxanthin and lutein. This occurred in parallel with a sustained depression of Fv/Fm. In Persea indica, a closely related but low Lx species, Fv/Fm recovered faster after a similar light treatment, suggesting the involvement of the Lx cycle in sustained energy dissipation. Furthermore, the seasonal correlation between non-reversible Lx and V photoconversions and pre-dawn Fv/Fm in sun leaves of sweet bay supported the conclusion that the Lx cycle is involved in a slowly reversible downregulation of photosynthesis analogous to the V cycle. [source] Improvement in behavioral symptoms and advance of activity acrophase after short-term bright light treatment in severe dementiaPSYCHIATRY AND CLINICAL NEUROSCIENCES, Issue 4 2004ARVID SKJERVE psyd Abstract Ten elderly subjects with severe dementia were given bright light (5000,8000 lux) for 45 min each morning for 4 weeks. Two rating scales of behavioral symptoms in dementia were used as outcome measures: Cohen-Mansfield Agitation Inventory (CMAI) and Behavior Pathology In Alzheimer's Disease Rating Scale (BEHAVE-AD), a scale for sleep,wake disturbances, and actigraphy to monitor activity rhythm. Behavioral symptoms improved with treatment. No changes in sleep,wake measures were found. There was an advance of the activity rhythm acrophase during treatment. These results suggest that short-time bright light improves behavioral symptoms and aspects of activity rhythm disturbances even in severely demented subjects. [source] Bright light treatment for night-time insomnia and daytime sleepiness in elderly people: Comparison with a short-acting hypnoticPSYCHIATRY AND CLINICAL NEUROSCIENCES, Issue 3 2000Akira Usui MD Abstract Night-time bright light (BL) treatment and triazolam (0.125 mg/day) were given to three healthy elderly people in a cross-over design. They kept a daytime sleepiness test and a sleep log, and their wrist-activity was monitored simultaneously. Subjectively, BL increased daytime sleepiness and naps, and decreased night-time sleep. Triazolam decreased daytime sleepiness and naps, and increased night-time sleep. Actigraphic night-time sleep and naps on the first day were similar to these results. However, on the fourth day night-time insomnia induced by BL had recovered, and naps were shorter than the baseline. Triazolam increased actigraphic naps as the days passed. [source] Reproductive challenges of a rare grass, Calamagrostis porteri subsp. insperata (Swallen) C. Greene: implications for habitat restorationAPPLIED VEGETATION SCIENCE, Issue 3 2009David J. Gibson Abstract Background: Habitat management for reproductively challenged rare species is a problem when there is insufficient knowledge of their autecology. This study investigated reproductive failure in the rare grass Calamagrostis porteri ssp. insperata (Swallen) C. Greene (Reed bentgrass). Does the management recommendation of high light stimulate clonal growth, flowering, and seed production? Location: Shawnee National Forest, IL, USA, and in a greenhouse and an experimental garden at Southern Illinois University, Carbondale, IL, USA. Methods: Clones obtained from the three known Illinois populations were grown in a glasshouse under experimental light and soil moisture treatments. After 3 years, plants from the high light treatment were planted outside in an experimental garden where the light treatments were maintained for two more years. In the field, vegetative and flowering tiller density, canopy cover, and associated biotic and abiotic variables including abundance of co-occurring plant species were monitored for 5 years. The overhead tree canopy was cleared over a portion of one population. Results: In the glasshouse, plants increased in size under high light and moist soil, and there were size differences among populations. Sixty-six per cent (20 of 30) of the genets flowered when planted outdoors under full sunlight but did not produce seed. In the field, flowering only occurred in Calamagrostis growing in the cleared area, but no seed were produced. The plants in the flowering population were smaller than plants in the other two populations. The herbaceous community associated with Calamagrostis in the open diverged from the communities remaining under the shade. Conclusions: This study highlights the difficulty of managing reproductively challenged rare species. Calamagrostis populations can be managed to enhance clonal growth, but establishment of new populations would require translocation of vegetative material as it is highly unlikely that seed can be obtained. [source] Photodynamic therapy of multiple actinic keratoses: reduced pain through use of visible light plus water-filtered infrared A compared with light from light-emitting diodesBRITISH JOURNAL OF DERMATOLOGY, Issue 3 2010V. Von Felbert Summary Background, Photodynamic therapy (PDT) with methyl aminolaevulinate (MAL) is an effective treatment for multiple actinic keratoses (AKs). Pain, however, is a major side-effect. Objectives, To compare pain intensity, efficacy, safety and cosmetic outcome of MAL PDT with two different light sources in an investigator-initiated, randomized, double-blind study. Methods, Eighty patients with multiple AKs grade I,II were assigned to two groups: group 1, MAL PDT with visible light and water-filtered infrared A (VIS + wIRA); group 2, MAL PDT with light from light-emitting diodes (LEDs), with a further division into two subgroups: A, no spray cooling; B, spray cooling on demand. MAL was applied 3 h before light treatment. Pain was assessed before, during and after PDT. Efficacy, side-effects, cosmetic outcome and patient satisfaction were documented after 2 weeks and 3, 6 and 12 months. Where necessary, treatment was repeated after 3 months. Results, Seventy-six of the 80 patients receiving MAL PDT completed the study. Patient assessment showed high efficacy, very good cosmetic outcome and high patient satisfaction. The efficacy of treatment was better in the group of patients without spray cooling (P = 0·00022 at 3 months, P = 0·0068 at 6 months) and showed no significant differences between VIS + wIRA and LED. VIS + wIRA was significantly less painful than LED: the median of maximum pain was lower in the VIS + wIRA group than in the LED group for PDT without spray cooling. Pain duration and severity assessed retrospectively were less with VIS + wIRA than with LED, irrespective of cooling. Conclusions, All treatments showed high efficacy with good cosmetic outcome and high patient satisfaction. Efficacy of treatment was better without spray cooling. VIS + wIRA PDT was less painful than LED PDT for PDT without spray cooling. [source] In vitro and in vivo comparison of two different light sources for topical photodynamic therapyBRITISH JOURNAL OF DERMATOLOGY, Issue 4 2006P. Babilas Summary Background, Photodynamic therapy (PDT) with 5-aminolaevulinic acid (ALA) is an effective and safe treatment option for the treatment of actinic keratosis (AK). Incoherent lamps are often used, matching the absorption maxima of ALA. Objectives, A comparative trial was performed to evaluate the efficacy of recently developed light-emitting diodes (LEDs). Methods, Human epidermal keratinocytes were incubated for 24 h with ALA (100, 200, 300, 400 or 500 ,mol L,1) and irradiated consecutively using either an incoherent halogen lamp (,em = 580,750 nm; 24 J cm,2; 40 mW cm,2) or an LED system (,em = 633 ± 3 nm; 3, 6, 12 or 24 J cm,2; 40 mW cm,2). Topical ALA-PDT was performed on 40 patients with AK (n = 584) in a symmetrical distribution suitable for two-sided comparison. After incubation with ALA (20% in cream base) irradiation was performed with the incoherent lamp (100 J cm,2; 160 mW cm,2) on one side and the LED system (40 J cm,2; 80 mW cm,2) on the opposite side followed by re-evaluation up to 6 months. Results, No significant differences between the LED system (3, 6, 12 or 24 J cm,2) and the incoherent light source (24 J cm,2) regarding cytotoxicity was found in vitro. The complete remission rate yielded in the in vivo investigation was also not significantly different at 6 weeks (P = 0·95), 3 months (P = 0·75) and 6 months (P = 0·61) following therapy. Six weeks following therapy complete remission rates of 84·3% (LED system) and 82·8% (incoherent lamp) were achieved. There was also no significant difference between both light sources regarding pain during light treatment (P = 0·67), patient satisfaction (P = 1·0) or cosmesis (P = 1·0) following therapy. Conclusions, These results show the efficacy of an LED system for ALA-PDT both in vitro and in vivo. ALA-PDT with the LED system showed a noninferiority regarding the clinical outcome in the treatment of AK compared with the incoherent lamp. [source] The role of light for fish,zooplankton,phytoplankton interactions during winter in shallow lakes , a climate change perspectiveFRESHWATER BIOLOGY, Issue 5 2009METTE ELISABETH BRAMM Summary 1.,Variations in the light regime can affect the availability and quality of food for zooplankton grazers as well as their exposure to fish predation. In northern lakes light is particularly low in winter and, with increasing warming, the northern limit of some present-day plankton communities may move further north and the plankton will thus receive less winter light. 2.,We followed the changes in the biomass and community structure of zooplankton and phytoplankton in a clear and a turbid shallow lake during winter (November,March) in enclosures both with and without fish and with four different light treatments (100%, 55%, 7% and <1% of incoming light). 3.,In both lakes total zooplankton biomass and chlorophyll- a were influenced by light availability and the presence of fish. Presence of fish irrespective of the light level led to low crustacean biomass, high rotifer biomass and changes in the life history of copepods. The strength of the fish effect on zooplankton biomass diminished with declining light and the effect of light was strongest in the presence of fish. 4.,When fish were present, reduced light led to a shift from rotifers to calanoid copepods in the clear lake and from rotifers to cyclopoid copepods in the turbid lake. Light affected the phytoplankton biomass and, to a lesser extent, the phytoplankton community composition and size. However, the fish effect on phytoplankton was overall weak. 5.,Our results from typical Danish shallow eutrophic lakes suggest that major changes in winter light conditions are needed in order to have a significant effect on the plankton community. The change in light occurring when such plankton communities move northwards in response to global warming will mostly be of modest importance for this lake type, at least for the rest of this century in an IPCC A2 scenario, while stronger effects may be observed in deep lakes. [source] Modulation of the bacterial response to spectral solar radiation by algae and limiting nutrientsFRESHWATER BIOLOGY, Issue 11 2002J. M. Medina-Sánchez SUMMARY 1. The response of bacterial production (measured as [3H]TdR incorporation rate) to spectral solar radiation was quantified experimentally in an oligotrophic high-mountain lake over 2 years. Bacterial responses were consistent: ultraviolet-B (UVB) was harmful, whereas ultraviolet-A (UVA) + photosynthetically active radiation (PAR) and PAR enhanced bacterial activity. Full sunlight exerted a net stimulatory effect on bacterial activity in mid-summer but a net inhibitory effect towards the end of the ice-free period. 2. Experiments were undertaken to examine whether the bacterial response pattern depended on the presence of algae and/or was modulated by the availability of a limiting inorganic nutrient (phosphorus, P). In the absence of algae, [3H]TdR incorporation rates were significantly lower than when algae were present under all light treatments, and the consistent bacterial response was lost. This suggests that the bacterial response to spectral solar radiation depends on fresh-C released from algae, which determines the net stimulatory outcome of damage and repair in mid-summer. 3. In the absence of algae, UVB radiation inhibited bacteria when they were strongly P-deficient (mean values of N : P ratio: 46.1), whereas it exerted no direct effect on bacterial activity when they were not P-limited. 4. P-enrichment of lake water markedly altered the response of bacteria to spectral solar radiation at the end of ice-free period, when bacteria were strongly P-deficient. Phosphorus enrichment suppressed the inhibitory effect of full sunlight that was observed in October, both in whole lake water (i.e. including algae) and in the absence of algae. This indicates that the bacterial P-deficiency, measured as the cellular N : P ratio, was partly responsible for the net inhibitory effect of full sunlight, implying a high bacterial vulnerability to UVB. [source] Trade-offs in low-light CO2 exchange: a component of variation in shade tolerance among cold temperate tree seedlingsFUNCTIONAL ECOLOGY, Issue 2 2000M. B. Walters Abstract 1.,Does enhanced whole-plant CO2 exchange in moderately low to high light occur at the cost of greater CO2 loss rates at very-low light levels? We examined this question for first-year seedlings of intolerant Populus tremuloides and Betula papyrifera, intermediate Betula alleghaniensis, and tolerant Ostrya virginiana and Acer saccharum grown in moderately low (7·3% of open-sky) and low (2·8%) light. We predicted that, compared with shade-tolerant species, intolerant species would have characteristics leading to greater whole-plant CO2 exchange rates in moderately low to high light levels, and to higher CO2 loss rates at very-low light levels. 2.,Compared with shade-tolerant A. saccharum, less-tolerant species grown in both light treatments had greater mass-based photosynthetic rates, leaf, stem and root respiration rates, leaf mass:plant mass ratios and leaf area:leaf mass ratios, and similar whole-plant light compensation points and leaf-based quantum yields. 3.,Whole-plant CO2 exchange responses to light (0·3,600 µmol quanta m,2 s,1) indicated that intolerant species had more positive CO2 exchange rates at all but very-low light (< 15 µmol quanta m,2 s,1). In contrast, although tolerant A. saccharum had a net CO2 exchange disadvantage at light > 15 µmol quanta m,2 s,1, its lower respiration resulted in lower CO2 losses than other species at light < 15 µmol quanta m,2 s,1. 4.,Growth scaled closely with whole-plant CO2 exchange characteristics and especially with integrated whole-plant photosynthesis (i.e. leaf mass ratio × in situ leaf photosynthesis). In contrast, growth scaled poorly with leaf-level quantum yield, light compensation point, and light-saturated photosynthetic rate. 5.,Collectively these patterns indicated that: (a) no species was able to both minimize CO2 loss at very-low light (i.e. < 15 µmol quanta m,2 s,1) and maximize CO2 gain at higher light (i.e. > 15 µmol quanta m,2 s,1), because whole-plant respiration rates were positively associated with whole-plant photosynthesis at higher light; (b) shade-intolerant species possess traits that maximize whole-plant CO2 exchange (and thus growth) in moderately low to high light levels, but these traits may lead to long-term growth and survival disadvantages in very-low light (< 2·8%) owing, in part, to high respiration. In contrast, shade-tolerant species may minimize CO2 losses in very-low light at the expense of maximizing CO2 gain potential at higher light levels, but to the possible benefit of long-term survival in low light. [source] The use of light-emitting diode therapy in the treatment of photoaged skinJOURNAL OF COSMETIC DERMATOLOGY, Issue 3 2007FACCS, FRACGP, Fabien Baez MBBS, MAACS, MCPSA Summary Background, Light-emitting diode (LED) therapy is an increasingly popular methodology for the treatment of sun damage. Combination use of light wavelengths reported to stimulate collagen synthesis and accelerate fibroblast,myofibroblast transformation may display a composite rejuvenative effect. Objective, To clinically assess reduction in sun damage signs following a 5-week course of LED therapy and to assess subject's perception of the treatment. Methods, Thirteen subjects with wrinkles or fine lines in the periorbital and nasolabial region and those presenting Glogau scale photodamage grade II,III received nine 20-min duration light treatments using the OmniluxÔ LED system. The treatments combined wavelengths of 633 and 830 nm at fluences of 126 and 66 J/cm2, respectively. Sun-damage reduction was assessed at 6, 9, and 12 weeks by clinical photography and patient satisfaction scores. Results, The majority of subjects displayed "moderate" (50%) or "slight" (25%) response to treatment at investigator assessment. Treatment of the periorbital region was reported more effective than the nasolabial region. At 12-week follow-up, 91% of subjects reported improved skin tone, and 82% reported enhanced smoothness of skin in the treatment area. Conclusion, Good response to LED therapy has been shown in this modest sample. Larger trials are needed to assess optimum frequency of light treatments and overall treatment time. [source] An experimental test of a visual-based push,pull strategy for control of wood boring phytosanitary pestsAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 3 2009Stephen Mark Pawson Abstract 1,International phytosanitary standards require mandatory fumigation for key wood boring beetle pests prior to export. Pressure to reduce the use of toxic fumigants has created a need for alternative control techniques. 2,A visual based push,pull strategy that exploits a differential attraction to yellow and ultra violet (UV) lights was tested for its efficacy at controlling Cerambycidae. 3,The relative attraction of four ,push' lighting treatments [two yellow (high and low-pressure Sodium), one white (metal halide) and a control (no light)] to beetles was assessed. Highly attractive UV ,pull' traps were compared with a paired control trap, the difference used as a measure of the UV traps attractiveness to residual beetles attracted by ,push' lights. 4,Trap catch beneath the two yellow ,push' lights was more similar to the control (no light) treatment than the white light for both species. Control ,push' lights had the highest average catch of Arhopalus ferus, whereas white light was least attractive. This finding was counter intuitive to expectations, and potential mechanisms are discussed. The white ,push' light was most attractive to Prionoplus reticularis. 5,Ultraviolet ,pull' traps were highly attractive to residual beetles drawn to yellow ,push' light treatments. Relative attraction to the UV ,pull' traps beneath control and white ,push' lights differed between species. 6,The results obtained suggest that a push,pull strategy combining yellow site lighting with UV kill traps could provide site specific control of wood borers. Future research should attempt large-scale trials that are subject to competing alternative stimuli at a wood processing site. [source] EFFECTS OF UV RADIATION ON GROWTH AND PHLOROTANNINS IN FUCUS GARDNERI (PHAEOPHYCEAE) JUVENILES AND EMBRYOS,JOURNAL OF PHYCOLOGY, Issue 3 2004Brianne E. Henry Diminishing levels of atmospheric ozone are increasing UV stress on intertidal algae. Early developmental stages tend to be more susceptible to environmental stresses; however, little research has examined how these stages are protected from UV radiation (UVR). Many brown algae contain high levels of phlorotannins, which are thought to function in screening UVR. In this study, we tested the effects of ambient levels of UV-B and UV-A on growth and phlorotannin production in 1- to 2-cm juvenile and microscopic postsettlement embryos of the intertidal alga Fucus gardneri Silva. Algae were grown in four light treatments: 1) ambient light; 2) under cellulose acetate, which lowered light quantity but did not affect light quality; 3) under MylarTM, which filtered UV-B; and 4) under PlexiglasTM, which blocked UV-A and UV-B. Over a 3-week period, UV-B inhibited and UV-A enhanced the growth of F. gardneri embryos, whereas the growth of juveniles was not affected. Phlorotannin concentrations of both embryos and juveniles did not differ in any of the light treatments. Our results suggest that embryos of F. gardneri are susceptible to UV light but develop a tolerance to it as they mature. This tolerance may result from increases in phlorotannin concentrations that occur during maturation; however, phlorotannin production in embryonic or juvenile stages is either not induced by UV light or takes more than 3 weeks to occur. [source] Light-Enhanced Resistance to Magnaporthe grisea Infection in the Rice Sekiguchi Lesion MutantsJOURNAL OF PHYTOPATHOLOGY, Issue 4 2000S. Arase The rice sl mutant showed two types of responses to Magnaporthe grisea infection by light treatments. One was an sl -mutant-type response characterized by Sekiguchi lesion expression under light waves of 400,700 nm, and the other was a wild-type response characterized by blast and/or necrotic spot lesion expression in the dark or at wavelength between 290 and 330 nm. There was a large difference in the resistance to M. grisea infection between the mutant- and wild-type responses in the rice sl mutant. When the mutant-type response was induced in the rice sl mutant, the disease resistance was enhanced relative to that in the wild-type response. Enhanced resistance was demonstrated by two components: (a) the number of Sekiguchi lesions was reduced relative to that of blast or necrotic lesions; (b) sporulation of M. grisea was not induced in Sekiguchi lesions. The enhanced resistance was dependent on light of 400,700 nm. Zusammenfassung In Abhängigkeit von einer Bestrahlung mit Licht zeigte die sl -Mutante von Reis zwei Typen von Reaktionen auf Magnaporthe-grisea -Infektionen. Zum einen trat eine Reaktion vom sl-Mutantentyp auf, charakterisiert durch Expression von Sekiguchi-Läsionen bei Wellenlängen von 400 bi 700 nm. Zum anderen war eine Wildtypreak-tion festzustellen, bei der es zu Bräune und/oder Expression nekrotischer Flecken bei Dunkelheit oder bei Wellenlängen zwischen 290 und 330 nm kam. Hinsichtlich der Resistenz gegen die M.-grisea -Infektion bestand ein großer Unterschied zwischen den Mutanten- und den Wildtypreaktionen der sl -Mutante des Reis. Wurde die Reaktion vom Mutantentyp in der sl -Mutante induziert, so war die Krankheitsresistenz im Vergleich zur Wildtypreaktion erhöht. Die höhere Resistenz zeigte sich an zwei Komponenten: (a) die Zahl der Sekiguchi-Läsionen war kleiner als die der braunen bzw. nekrotischen Läsionen (b) in Sekiguchi-Läsionen wurde keine Sporulation von M. grisea induziert. Die erhöhte Resistenz war abhängig von Licht im Wellenlängenbereich 400 bis 700 nm. [source] PAR and UV Effects on Vertical Migration and Photosynthesis in Euglena gracilis,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 4 2007Peter Richter Recently it was shown that the unicellular flagellate Euglena gracilis changes the sign of gravitaxis from negative to positive upon excessive radiation. This sign change persists in a cell culture for hours even if subsequently transferred to dim light. To test the ecological relevance of this behavior, a vertical column experiment was performed (max. depth 65 cm) to test distribution, photosynthetic efficiency and motility in different horizons of the column (surface, 20, 40 and 65 cm). One column was covered with a UV cut-off filter, which transmits photosynthetically active radiation (PAR) only, the other with a filter which transmits PAR and UV. The columns were irradiated with a solar simulator (PAR 162 W m,2, UV-A 32.6 W m,2, UV-B 1.9 W m,2). The experiment was conducted for 10 days, normally with a light/dim light cycle of 12 h:12 h, but in some cases the light regime was changed (dim light instead of full radiation). Under irradiation the largest fraction of cells was found at the bottom of the column. The cell density decreased toward the surface. Photosynthetic efficiency, determined with a pulse amplitude modulated fluorometer, was negligible at the surface and increased toward the bottom. While the cell suspension showed a positive gravitaxis at the bottom, the cells in the 40 cm horizon were bimodally oriented (about the same percentage of cells swimming upward and downward, respectively). At 20 cm and at the surface the cells showed negative gravitaxis. Positive gravitaxis was more pronounced in the UV + PAR samples. At the surface and in the 20 and 40 cm horizons photosynthetic efficiency was better in the PAR-only samples than in the PAR + UV samples. At the bottom photosynthetic efficiency was similar in both light treatments. The data suggest that high light reverses gravitaxis of the cells, so that they move downward in the water column. At the bottom the light intensity is lower (attenuation of the water column and self shading of the cells) and the cells recover. After recovery the cells swim upward again until the negative gravitaxis is reversed again. [source] Correlation between leaf growth variables suggest intrinsic and early controls of leaf size in Arabidopsis thalianaPLANT CELL & ENVIRONMENT, Issue 11 2005SARAH J. COOKSON ABSTRACT Leaf development is affected by both internal (genetic) and external (environmental) regulatory factors. The aim of this work was to investigate how leaf growth variables are related to one another in a range of environments. The leaf growth variables of wild-type Arabidopsis thaliana and leaf development mutants (ang4, ron2-1, elo1, elo2 and elo4) were studied under different incident light treatments (light and shade). The leaves studied were altered in various leaf development variables, such as the duration of expansion, relative and absolute expansion rates, epidermal cell size, epidermal cell number and initiation rate. Final leaf area was correlated to maximal absolute leaf expansion rate and cell number, but not to duration of leaf expansion or cell size. These relationships were common to all studied genotypes and light conditions, suggesting that leaf size is determined early in development. In addition, the early variables involved in leaf development were correlated to one another, and initial relative expansion rate was negatively correlated to the duration of expansion. These relationships between the leaf development variables were used to construct a conceptual model of leaf size control. [source] | ||||||||||||||||||||||||||||