Topical application of spent coffee ground extracts protects skin from ultraviolet B-induced photoaging in hairless mice.

The aim of this study was to evaluate the protective effect of spent coffee ground (SCG) on ultraviolet (UV) B-induced photoaging in hairless mice. The oil fraction (OSCG) and ethanol extract (ESCG) of SCG were prepared from SCG. OSCG contained a much higher level of caffeine (547.32 ± 1.68 µg mg(-1)) when compared to the sum of its chlorogenic acid derivatives (∼119 µg mg(-1)), and pyrazines were the major aromatic compounds in OSCG. OSCG effectively inhibited the UVB-induced increase in intracellular reactive oxygen species in HaCaT cells. Topical application of OSCG or ESCG significantly reduced the UVB-induced wrinkle formation in mice dorsal skin. The combined application of OSCG and ESCG (OEH) led to a decrease in the wrinkle area by over 35% when compared with the UVB-treated control (UVBC). Epidermal thickness was also reduced by 40%. This result was connected to the significant reduction in transdermal water loss (27%) and erythema formation (48%) that result from UVB irradiation. Polarization-sensitive optical coherence tomography (PS-OCT) and antibody-based histological analyses showed that OSCG and ESCG effectively suppressed the UVB-induced decrease in collagen content. The level of type 1 collagen (COL1) in the OEH group was enhanced by around 40% compared with the UVB control group (UVBC). This was attributed to the down-regulation of matrix metalloproteinases (MMP2, 9, and 13), which are known to be responsible for collagen destruction. Our results indicate that topical treatment with OSCG/ESCG protects mouse skin from UVB-induced photoaging by down-regulating MMPs; therefore, suggesting the potential of SCG extracts as a topical anti-photoaging agent.

UVB induces epidermal 11ß-hydroxysteroid dehydrogenase type 1 activity in vivo.

Detrimental consequences of ultraviolet radiation (UVR) in skin include photoageing, immunosuppression and photocarcinogenesis, processes also significantly regulated by local glucocorticoid (GC) availability. In man, the enzyme 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) generates the active GC cortisol from cortisone (or corticosterone from 11-dehydrocorticosterone in rodents). 11ß-HSD1 oxo-reductase activity requires the cofactor NADPH, generated by hexose-6-phosphate dehydrogenase. We previously demonstrated increased 11ß-HSD1 levels in skin obtained from photoexposed versus photoprotected anatomical regions. However, the direct effect of UVR on 11ß-HSD1 expression remains to be elucidated. To investigate the cutaneous regulation of 11ß-HSD1 following UVR in vivo, the dorsal skin of female SKH1 mice was irradiated with 50, 100, 200 and 400 mJ/cm(2) UVB. Measurement of transepidermal water loss, 11ß-HSD1 activity, mRNA/protein expression and histological studies was taken at 1, 3 and 7 days postexposure. 11ß-HSD1 and hexose-6-phosphate dehydrogenase mRNA expression peaked 1 day postexposure to 400 mJ/cm(2) UVB before subsequently declining (days 3 and 7). Corresponding increases in 11ß-HSD1 protein and enzyme activity were observed 3 days postexposure coinciding with reduced GC receptor mRNA expression. Immunofluorescence studies revealed 11ß-HSD1 localization to hyperproliferative epidermal keratinocytes in UVB-exposed skin. 11ß-HSD1 expression and activity were also induced by 200 and 100 (but not 50) mJ/cm(2) UVB and correlated with increased transepidermal water loss (indicative of barrier disruption). UVB-induced 11ß-HSD1 activation represents a novel mechanism that may contribute to the regulation of cutaneous responses to UVR exposure.

Modeling and validation of microwave ablations with internal vaporization.

Numerical simulation is increasingly being utilized for computer-aided design of treatment devices, analysis of ablation growth, and clinical treatment planning. Simulation models to date have incorporated electromagnetic wave propagation and heat conduction, but not other relevant physics such as water vaporization and mass transfer. Such physical changes are particularly noteworthy during the intense heat generation associated with microwave heating. In this paper, a numerical model was created that integrates microwave heating with water vapor generation and transport by using porous media assumptions in the tissue domain. The heating physics of the water vapor model was validated through temperature measurements taken at locations 5, 10, and 20 mm away from the heating zone of the microwave antenna in homogenized ex vivo bovine liver setup. Cross-sectional area of water vapor transport was validated through intraprocedural computed tomography (CT) during microwave ablations in homogenized ex vivo bovine liver. Iso-density contours from CT images were compared to vapor concentration contours from the numerical model at intermittent time points using the Jaccard index. In general, there was an improving correlation in ablation size dimensions as the ablation procedure proceeded, with a Jaccard index of 0.27, 0.49, 0.61, 0.67, and 0.69 at 1, 2, 3, 4, and 5 min, respectively. This study demonstrates the feasibility and validity of incorporating water vapor concentration into thermal ablation simulations and validating such models experimentally.

Analysis of ultrasonic waves propagating in a bone plate over a water half-space with and without overlying soft tissue.

Recent in vitro studies have shown that guided waves can characterize bone properties. However, for clinical applications to be viable, the soft-tissue layer should be considered. This study examined the effect of soft tissue on guided waves using a bovine bone plate over a water half-space and overlaid by a 4-mm gelatin-based soft-tissue mimic. The data (with and without soft tissue) clearly show a high-frequency, fast-propagating wave packet and a low-frequency, delayed phase group. The presence of soft tissue attenuates the signals significantly and increases mode density and number as predicted by theory. The data retain higher frequency content than the bone-plate data at large offsets. Using theoretical dispersion curves, the guided modes can be identified with mode 1 (similar to the A0 Lamb mode) minimally affected by the addition of soft tissue. There is infiltration of high-frequency, late-arriving energy within the low-velocity guided-wave regime. Results of travel-time calculation suggest that P-wave and PP-reflections/multiples within the soft tissue may be responsible for the high-frequency oscillations.

Evaluación del peso seco y el agua corporal según bioimpedancia vectorial frente al método tradicional / Assessing dry weight and body water using bioimpedance vector analysis compared to the traditional method

Introducción: La bioimpedancia eléctrica se puede utilizar para establecer el estado de hidratación y nutrición en hemodiálisis. La valoración del estado de hidratación de los pacientes se hace habitualmente a modo de 'arte clínico' mediante el concepto de 'peso seco'. Existen pocos trabajos que estudien la concordancia entre el peso seco estimado de forma clínica y el deducido post-bioimpedancia. Material y métodos: Se estudiaron 36 pacientes (26 varones y 10 mujeres). Se realizó bioimpedancia eléctrica vectorial antes y 30’ después de diálisis de mitad de semana midiendo, el peso, el agua total y su distribución, el ángulo de fase, la relación de Na/K, y la posición del vector de cada paciente en el normograma de esferas: percentiles 50,75 y 95. El peso-seco se estimó según la valoración subjetiva del nefrólogo, enfermera y paciente. Además en 12 pacientes estables se continuó el análisis por bioimpedancia durante 4 semanas. Resultados: La edad fue de 69.6±12.5 (r=29-89). Prediálisis el peso fue de 73.1±14.1, y postdiálisis de 70.4±13.6. El agua corporal total fue de 24.7±2.8 L/m (53.7±8.2% del peso); 22.1±3.0 L (56.2±5.9% del peso) correspondían a agua extracelular y 17.4±3.8 L/m a intracelular. Posthemodiálisis, el agua total se redujo a 22.8±2.4 L/m (51.8±8.6% del peso) (23.5±2.2 L en varo- María Teresa Centellas Tristán, María Luisa Garcinuño Martín, Reyes González de Antonio, Elvira Roig Gaspar, Daniel Corbacho Barrenechea Enfermeros/as, Servicio de Nefrología. Complejo Asistencial de Ávila nes; y 21,5±3 L en mujeres) de los que 19.6±2.5 L (54,3±5.8% del peso) correspondían a agua extracelular y 16.7±3.3 a agua intracelular. Un varón y 5 mujeres sobrepasaron el valor de referencia más alto. El peso posthemodiálisis fue de 70,4±13,6 ligeramente superior al peso seco establecido: 70,2±13,4 (p=0,02). El ángulo de fase fue <4 en 9 pacientes (25%) y el intercambio Na/K en 13 pacientes (36%) era >1.2, indicando malnutrición. El estudio de las elipses mostró en el percentil 50 el 58.3% (21 pacientes). El resto se repartían en el 75% de sobrehidratación: 9 (25%) y en el 95%, 5 (13,8%). En los 12 pacientes en los que se efectuaron las bioimpedancias seriadas durante 4 semanas, los resultados mostraron variaciones poco significativas de los parámetros estudiados. Conclusiones: Aunque la bioimpedancia aporta conocimientos más exactos sobre la composición hídrica corporal y la distribución del agua, el peso seco establecido por estimación clínica sigue siendo de gran valor. La bioimpedancia ayuda a detectar pequeños cambios subclínicos, que podrían tener trascendencia a más largo plazo. La bioimpedancia pone de manifi esto de forma objetiva la desnutrición presente en casi la mitad de pacientes de hemodiálisis(AU)

Introduction: Electrical bioimpedance can be used to establish the hydration and nutritional state in haemodialysis. Assessing the hydration status of patients is habitually done as a 'clinical art' using the concept of 'dry weight'. There are few studies that examine the concordance between dry weight estimated clinically and the dry weight deduced postbioimpedance analysis. Material and methods: 36 patients were studied (26 men and 10 women). Electrical bioimpedance vector analysis was performed before and 30’ after midweek dialysis, measuring weight, total water and its distribution, phase angle, Na/K ratio, and the position of each patient’s vector in the sphere normogram: percentiles 50.75 and 95. Dry weight was estimated according to the subjective assessment of the nephrologist, nurse and patient. Furthermore, in 12 stable patients the bioimpedance analysis continued for 4 weeks. Results: The age was 69.6±12.5 (r=29-89). Weight was 73.1±14.1 predialysis, and 70.4±13.6 postdialysis. Total body water was 24.7±2.8 L/m (53.7±8.2% of weight); 22.1±3.0 L (56.2±5.9% of weight) corresponded to extracellular water and 17.4±3.8 L/m to intracellular water. Following haemodialysis, total water fell to 22.8±2.4 L/m (51.8±8.6% of weight) (23.5±2.2 L in men; and 21.5±3 L in women) of which 19.6±2.5 L (54.3±5.8% of weight) corresponded to extracellular water and 16.7±3.3 to intracellular water. One man and 5 women exceeded the highest reference value. Posthaemodialysis weight was 70.4±13.6, slightly higher than the established dry weight: 70.2±13.4 (p=0.02). The phase angle was <4 in 9 patients (25%) and Na/K exchange in 13 patients (36%) was >1.2, indicating malnutrition. The study of the ellipses showed 58.3% (21 patients) in the 50th percentile. The rest were distributed in the 75th percentile of overhydration: 9 (25%) and in the 95th percentile, 5 (13.8%). In the 12 patients on whom series of bioimpedance analyses were carried out over 4 weeks, the results showed variations of little significance from the parameters studied. Conclusions: Although bioimpedance provides more accurate knowledge on body hydric composition and on the distribution of water, the dry weight established by clinical estimate continues to be of great value. Bioimpedance helps to detect small sub-clinical changes which could be more relevant in the longer term. Bioimpedance objectively shows the malnutrition present in almost half of haemodialysis patients(AU)

Evaluation of drug and sunscreen permeation via skin irradiated with UVA and UVB: comparisons of normal skin and chronologically aged skin.

BACKGROUND: Ultraviolet (UV) exposure is the predominant cause of skin aging. A systematic evaluation of drug skin permeation via photoaged skin is lacking. OBJECTIVES: The aim of this work was to investigate whether UVA and UVB affect absorption by the skin of drugs and sunscreens, including tetracycline, quercetin, and oxybenzone. METHODS: The dorsal skin of nude mice was subjected to UVA (24 and 39 J/cm(2)) or UVB (150, 200, and 250 mJ/cm(2)) irradiation. Levels of skin water loss, erythema, and sebum were evaluated, and histological examinations of COX-2 and claudin-1 expressions were carried out. Permeation of the permeants into and through the skin was determined in vitro using a Franz cell. In vivo skin uptake was also evaluated. Senescent skin (24 weeks old) was used for comparison. RESULTS: Wrinkling and scaling were significant signs of skin treated with UVA and UVB, respectively. The level of claudin-1, an indicator of tight junctions (TJs), was reduced by UVA and UVB irradiation. UVA enhanced tetracycline and quercetin skin deposition by 11- and 2-fold, respectively. A similar enhancement was shown for flux profiles. Surprisingly, a lower UVA dose revealed greater enhancement compared to the higher dose. The skin deposition and flux of tetracycline both decreased with UVB exposure. UVB also significantly reduced quercetin flux. The skin absorption behavior of chronologically aged skin approximated that of the UVA group, with photoaged skin showing higher enhancement. UV generally exhibited a negligible effect on modulating oxybenzone permeation. CONCLUSIONS: Skin disruption produced by UV does not necessarily result in enhanced skin absorption. It depends on the UV wavelength, irradiated energy, and physicochemical properties of the permeant. To the best of our knowledge, this is the first report establishing drug permeation profiles for UV-irradiated skin.

The magnetic field dependence of water T1 in tissues.

The magnetic field dependence of the composite (1)H(2)O nuclear magnetic resonance signal T(1) was measured for excised samples of rat liver, muscle, and kidney over the field range from 0.7 to 7 T (35-300 MHz) with a nuclear magnetic resonance spectrometer using sample-shuttle methods. Based on extensive measurements on simpler component systems, the magnetic field dependence of T(1) of all tissues studied are readily fitted at Larmor frequencies above 1 MHz with a simple relaxation equation consisting of three contributions: a power law, A*ω(-0.60) related to the interaction of water with long-lived-protein binding sites, a logarithmic term B*τ(d) *log(1+1/(ωτ(d))(2)) related to water diffusion at macromolecular interfacial regions, and a constant term associated with the high frequency limit of water-spin-lattice relaxation. The parameters A and B include the concentration and surface area dependences respectively. The logarithmic diffusion term becomes significant at high magnetic fields and is consistent with rapid translational dynamics at macromolecular surfaces. The data are fitted well with translational correlation times of approximately 15 ps for human brain white matter, but with a B value three times larger than gray matter tissues. This analysis suggests that the water-surface translational correlation time is approximately three times longer than in gray matter.

Objective and longitudinal assessment of dermatitis after postoperative accelerated partial breast irradiation using high-dose-rate interstitial brachytherapy in patients with breast cancer treated with breast conserving therapy: reduction of moisture deterioration by APBI.

PURPOSE: To objectively evaluate the radiation dermatitis caused by accelerated partial breast irradiation (APBI) using high-dose-rate interstitial brachytherapy. PATIENTS AND METHODS: The skin color and moisture changes were examined using a newly installed spectrophotometer and corneometer in 22 patients who had undergone APBI using open cavity implant high-dose-rate interstitial brachytherapy (36 Gy in six fractions) and compared with the corresponding values for 44 patients in an external beam radiotherapy (EBRT) control group (50-60 Gy in 25-30 fractions within 5-6 weeks) after breast conserving surgery. RESULTS: All values changed significantly as a result of APBI. The extent of elevation in a∗ (reddish) and reduction in L∗ (black) values caused by APBI were similar to those for EBRT, with slightly delayed recovery for 6-12 months after treatment owing to the surgical procedure. In contrast, only APBI caused a change in the b∗ values, and EBRT did not, demonstrating that the reduction in b∗ values (yellowish) depends largely on the surgical procedure. The changes in moisture were less severe after APBI than after EBRT, and the recovery was more rapid. The toxicity assessment using the Common Toxicity Criteria, version 3, showed that all dermatitis caused by APBI was Grade 2 or less. CONCLUSION: An objective analysis can quantify the effects of APBI procedures on color and moisture cosmesis. The radiation dermatitis caused by APBI using the present schedule showed an equivalent effect on skin color and a less severe effect on moisture than the effects caused by standard EBRT.

Study of the formalism used to determine the absorbed dose for low-energy x-ray beams.

We have studied the procedure commonly recommended by dosimetry protocols for the determination of the absorbed dose in water for low-energy x-rays beams, generated with potentials up to 150 kVp. X-ray beams with different spectra obtained with the XCOMP5R code were transported using the Monte Carlo code PENELOPE in order to calculate backscatter factors and mass-energy absorption coefficients. We have analyzed the uncertainty in the absorbed doses, calculated using the half-value layer to characterize the x-ray beams, due to the uncertainties in both backscatter factors and mass-energy absorption coefficients. We have found that this uncertainty is larger than 5% and can reach values above 11% for some HVL(1) values. The characterization of these doses with the homogeneity coefficient or the generating potential, in addition to the half-value layer is also studied. Using HVL(1) and the kVp, the absorbed dose to water can be reproduced to within 3% for all spectra.

Short-TE localised 1H MRS of the human brain at 3 T: quantification of the metabolite signals using two approaches to account for macromolecular signal contributions.

The goal of this study was to validate metabolite quantification at short TE, with particular focus on how to best account for the macromolecular signal contribution. A robust, short-TE PRESS protocol is presented, which allows reliable quantification, in vivo, of metabolite signals at 3 T in human brain. Water suppression was adapted to the experimental conditions at 3 T. Metabolite signal from the parietal white matter was quantified in the time domain using QUEST (jMRUI). The increased macromolecular signal contribution at short TE was dealt with by two approaches, based on either metabolite nulling or initial signal truncation. A detailed comparison of the two approaches was made. The first used a metabolite-nulled signal, measured either individually or averaged over different subjects. The second used the total signal, metabolites and macromolecules, from a single scan. The two approaches gave similar quantification results in terms of metabolite concentrations, but differed in their precision and the number of metabolites quantified reliably. With an average metabolite-nulled baseline, a set of seven metabolites could be reliably quantified in parietal white matter under these experimental conditions: N-acetylaspartate, myo-inositol, glucose, glutamate, glutathione, creatine and choline. When initial signal truncation was used, glucose was removed from this set. The short TE (10-11 ms) facilitated quantification of glutamate. The reliable quantification of N-acetylaspartyl glutamate at 3 T proved very difficult.

MRI study of human brain exposed to weak direct current stimulation of the frontal cortex.

OBJECTIVE: To determine whether weak transcranial direct current stimulation (tDCS), which is an interesting new tool inducing prolonged cortical excitability shifts in humans, induces brain edema, disturbance of the blood-brain barrier or structural alterations of the brain detectable by magnetic resonance imaging (MRI). METHODS: In 10 healthy individuals, tDCS, which is known to alter cortical excitability for about 1 h, was applied over motor and pre-frontal cortices. contrast-enhanced t1-, t2-, and diffusion-weighted mri was performed immediately before, 30 and 60 min after tdcs. RESULTS: MRI performed 30 and 60 min after tDCS did not show pathological signal alterations in pre- and post-contrast-enhanced T1-weighted and diffusion-weighted MR sequences. CONCLUSIONS: tDCS protocols which are known to result in cortical excitability changes persisting for an hour after stimulation do not induce brain edema or alterations of the blood-brain barrier or cerebral tissue detectable by MRI. SIGNIFICANCE: These results deliver further evidence for the safety of the currently applied tDCS protocols in humans.

Corona discharge influences ozone concentrations near rats.

Ozone can be produced by corona discharge either in dry air or when one electrode is submerged in water. Since ozone is toxic, we examined whether ozone production by corona near laboratory animals could reach levels of concern. Male rats were exposed to a corona discharge and the concentration of ozone produced was measured. The resulting concentration of ozone ranged from ambient levels to 250 ppb when animals were located 1 cm from a 10 kV source. Similar ozone concentrations were observed when a grounded water source was present. Possible explanations for, as well as concerns regarding, ozone production under these conditions are discussed.

Theoretical cross sections for electron collisions in water: structure of electron tracks.

To understand what happens when biological matter is irradiated needs a detailed knowledge of the microscopic distribution of interactions and especially of the energy deposited in irradiated matter. Monte Carlo event-by-event simulations are particularly suitable for this task. However, the development of these track-structure codes necessitates accurate interaction cross sections for all the electronic processes: ionization, excitation and elastic scattering. In these conditions, we have recently developed a Monte Carlo code for electrons in water, this latter being commonly used to simulate the biological medium. All the electronic processes are studied in detail via theoretical differential and total cross-section calculations. The purpose of this work is to make an inter-comparison of our cross sections with those used in the electron track-structure codes developed in the literature, and to compare macroscopic quantities such as stopping powers and mean energy transfer distributions to available experimental data and/or to theoretical predictions in liquid water.

A novel method of studying total body water content using a resonant cavity: experiments and numerical simulation.

A novel electromagnetic method of obtaining total body water is proposed, in which the water content is obtained from the dielectric properties as measured by a resonant perturbation technique. A screened room acts as a radio-frequency cavity, in our case resonating at 59 MHz, a frequency at which both real and imaginary parts of the complex permittivity of tissues are correlated to their moisture content. The presence of a human subject in the room leads to both a negative shift in the room's resonant frequency and a reduction in its Q-factor. We simulated the room and the body using the transmission line matrix (TLM) method, a computational electromagnetic code which models the problem in the time domain. Experiment and numerical model showed good agreement for two orientations of the subject. The sensitivity of the technique was investigated by measuring the response before and after the subject drank a small quantity of water, less than 2% of body mass. The resulting change in the resonant frequency was significant, and was also predicted by the numerical model. The proposed technique for studying body composition is simple, non-invasive and employs non-ionizing radio waves at low power.

Continuous UVB irradiation to modify the biophysical properties and protein conformation of rat skin.

In order to determine the continuous irradiation effects of UVB on the skin of live Sprague Dawley (SD) rats, the changes in biophysical properties and protein conformation of the skin were studied. The continuous UVB irradiation affecting the water content, skin color and protein structure of the rat skin was investigated by using a skin surface hygrometer, a Chroma meter and an attenuated total reflection (ATR)/Fourier transform infrared (FT-IR) spectroscopy. Test areas on the dorsal skin were continuously irradiated with 600 +/- 10 microW/cm2 UVB for 56 h. Part of the dorsal skin was covered with a bandage as a non-irradiated control. The results indicated that the water content of the irradiated skin decreased with UVB irradiation, but the non-irradiated control skin exhibited a higher level of water content. The decrease in the skin's water-binding capacity from cracks induced by continuous UVB irradiation, and the occlusive dressing of the non-irradiated skin to prevent water loss and form full hydration might be responsible for the results. The decrease of L* value and the increase in a*, b* and delta E values in the skin color parameters with UVB irradiation indicates an incremental darkening of the skin and a marked increase in erythema. However, there was no significant change in skin color for the non-irradiated control skin. A slight modification of the protein secondary structure in the skin after continuous UVB irradiation was also evidenced by transforming the alpha-helix structure into a beta-sheet structure after long-term continuous UVB irradiation. Continuous UVB irradiation of SD rat skin may decrease the skin's water-binding capacity, cause darkening, increase erythema and modify the protein secondary structure of the skin.

Correlation of radiation tolerance dose of normal human organs with organ weight, blood, and water content.

The concerted effort to minimize the radiation exposure to normal human tissues while delivering a high radiation dose to the tumor often results in complications. This limits the efficacy of radiation treatment. Analysis of radiation tolerance dose with organ weight in 15 human organs yields a correlation coefficient of 0.62, whereas the correlation of radiation tolerance dose with blood and water content yields correlation coefficients of 0.82 and 0.60, respectively. Results indicate that as the organ weight and/or blood and water content increases, radiation tolerance dose decreases.

Alterations in skin properties during rapid and slow tissue expansion for breast reconstruction.

This study comprises 23 women who had had mastectomies because of breast cancer. They were randomly divided into two groups when they were admitted for breast reconstruction by tissue expansion. The first group was expanded rapidly, i.e., every day, and the other group was expanded slowly, i.e., every week. There were no other differences in the treatment between the two groups. Three months after completion of expansion, the expander was replaced by a permanent prosthesis. The follow-up time was up to 6 months after the second operation. Three different parameters--distensibility, elasticity, and hysteresis--were measured noninvasively on the breast skin and at a control site on several occasions throughout the treatment. During the treatment period there were no differences in skin properties between rapidly and slowly expanded patients. Of the three parameters, distensibility showed the most prominent changes: decreasing during the expansion period, increasing after the expander had been replaced by a permanent prosthesis, and decreasing during the following 6 months. Elasticity did not change significantly, except decreasing after insertion of the permanent prosthesis, and the hysteresis increased at the same time. These findings indicate that tissue expansion alters breast skin only to a small extent and that the mechanical resistance sometimes encountered during tissue expansion is due to deeper structures such as underlying muscles or capsule formation.