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Body Exposure (body + exposure)
Selected AbstractsTotal body exposure to ultraviolet radiation does not influence plasma levels of immunoreactive ,-endorphin in manPHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE, Issue 6 2001Marjolein Wintzen Background/Aims: A growing number of reports support evidence of proopiomelanocortin (POMC)-derived peptides in human skin cells, although not consistently. Also the effect of ultraviolet radiation (UVR) on cutaneous and plasma levels of these POMC peptides has not been established unequivocally. We hypothesized that production of ,-endorphin (,E) may explain the sense of well-being many people experience when sun-bathing. The aim of the present study was to investigate whether exposure of the skin to UVR elevates plasma ,E. Method: Healthy volunteers (n=26) received a single, weighted dose of 15 J/cm2 of UVA. Several times during the hour following irradiation, plasma ,E- immunoreactivity (,E-IR) was determined by radioimmunoassay. The effect of repeated exposure wasassessed in 35 patients treated with UVB, UVA, or UVA-1. Plasma ACTH-IR was monitored in parallel. Results: Overall, plasma levels of ,E-IR and ACTH-IR showed no significant changes during the experiment, indicating that these peptides are not influenced by single or repeated exposures to UVR of different wavelengths. Conclusion: On the basis of these results, the skin does not appear to contribute significantly to the levels of circulating ,E or ACTH. These data offer no support for the hypothesis that exposure to UVR leads to an increased concentration of circulating ,E, which could contribute to the feeling of well-being that often accompanies sun-bathing. [source] The effect of whole-body sunbed ultraviolet A exposure on the pharmacokinetics of the photolabile drug nifedipinePHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE, Issue 3 2000H. S. Al-Ajmi The calcium antagonist nifedipine absorbs ultraviolet A (UVA) radiation and readily photodegrades in vitro to a toxic nitroso-pyridine photoproduct. We examined whether whole body exposure of normal subjects to sunbed UVA radiation would affect the pharmacokinetics of nifedipine. Eight healthy, male, Caucasian volunteers (phototypes I,III) participated in this ethically approved, randomised, cross-over study. Each subject attended on 2 occasions, one week apart, and on each occasion was given a single oral dose (10 mg) of nifedipine following which blood samples were collected at 0, 0.5, 1. 1.5, 2, 2.5, 3, 3.5, 4, 5, 6 and 7 h. During one of the visits, 15 min after nifedipine ingestion, a whole-body UVA (sunbed comprising Philips R-UVA lamps) dose of 70% of the individual's predetermined minimal phototoxic dose was delivered over a period of 17,36 min. Plasma nifedipine levels were measured using a standard reverse-phase high-performance liquid chromatography method. The area under the plasma concentration-time curve (AUC) of nifedipine during the UVA irradiation session (median 206 ng,·,ml,1,·,h,1) was significantly higher than during the non-irradiation control session (median 174.5 ng,·,ml,1,·,h,1) (P=0.03; 95% C.I. for difference in medians 9.9 to 55.9 ng,·,ml,1,·,h,1). UVA irradiation did not significantly affect any of the other measured pharmacokinetic parameters (Cmax, t1/2, tmax). We demonstrate that sunbed UVA irradiation does not lead to in vivo photodegradation of nifedipine in healthy humans after a single dose. The apparent increase in AUC during UVA irradiation may be due to slightly slower metabolism of nifedipine in the presence of toxic photoproduct(s) or due to blood distribution changes affecting liver blood flow. [source] ORIGINAL RESEARCH,PAIN: Pain, Psychosocial, Sexual, and Psychophysical Characteristics of Women with Primary vs.THE JOURNAL OF SEXUAL MEDICINE, Issue 1 2009Secondary Provoked Vestibulodynia ABSTRACT Introduction., Women with provoked vestibulodynia (PVD), a common cause of dyspareunia, are typically considered a homogeneous group. However, research suggests that differences on some factors (e.g., medical history, pain characteristics, psychological functioning, treatment response) exist based upon whether the pain was present at first intercourse (primary PVD: PVD1) or developed at some later point (secondary PVD: PVD2). Aims., The purpose of this study was to examine differences in demographic variables, pain characteristics, psychosocial and psychosexual adjustment, and pain sensitivity between women with PVD1 and PVD2. Methods., Twenty-six women suffering from PVD (13 with PVD1 and 13 with PVD2) completed a screening assessment, a standardized gynecological examination, an interview, questionnaires, and a quantitative sensory testing session. Main Outcome Measures., These included pain ratings during the gynecological examination and interview, scores on measures of psychosocial/sexual functioning (e.g., Short Form-36 [SF-36] Health Survey, Female Sexual Function Index), and thresholds and pain ratings during thermal sensory testing over the dominant forearm and vulvar vestibule. Results., The women with PVD1 were more likely to be nulliparous, but they were not significantly different from the women with PVD2 on other demographic variables or in their pain ratings during the gynecological examination. The women with PVD1 reported lower levels of social and emotional functioning and heightened anxiety surrounding body exposure during sexual activity, and they also displayed lower heat pain tolerance over the forearm and lower heat detection and pain thresholds at the vulvar vestibule than the women with PVD2. Conclusions., The findings from this study support previous research indicating that women with PVD1 and PVD2 differ in a number of domains. Further research is needed to confirm and elaborate on these findings. Sutton KS, Pukall C, and Chamberlain S. Pain, psychosocial, sexual, and psychophysical characteristics of women with primary vs. secondary provoked vestibulodynia. J Sex Med 2009;6:205,214. [source] Electromagnetic Field Treatment of Nerve Crush Injury in a Rat Model: Effect of Signal Configuration on Functional RecoveryBIOELECTROMAGNETICS, Issue 4 2007Janet L. Walker Abstract Electromagnetic fields (EMFs) have been demonstrated to enhance mammalian peripheral nerve regeneration in vitro and in vivo. Using an EMF signal shown to enhance neurite outgrowth in vitro, we tested this field in vivo using three different amplitudes. The rat sciatic nerve was crushed. Whole body exposure was performed for 4 h/day for 5 days in a 96-turn solenoid coil controlled by a signal generator and power amplifier. The induced electric field at the target tissue consisted of a bipolar rectangular pulse, having 1 and 0.3 ms durations in each polarity, respectively. Pulse repetition rate was 2 per second. By varying the current, the coils produced fields consisting of sham (no current) and peak magnetic fields of 0.03 mT, 0.3 mT, and 3 mT, corresponding to peak induced electric fields of 1, 10, and 100 µV/cm, respectively, at the tissue target. Walking function was assessed over 43 days using video recording and measurement of the 1,5 toe-spread, using an imaging program. Comparing injured to uninjured hind limbs, mean responses were evaluated using a linear mixed statistical model. There was no difference found in recovery of the toe-spread function between any EMF treatments compared to sham. Bioelectromagnetics 28:256,263, 2007. © 2007 Wiley-Liss, Inc. [source] Induced current measurements in whole body exposure condition to radio frequency electric fieldsBIOELECTROMAGNETICS, Issue 8 2001Jonna Wilén Abstract The current induced in a human exposed to radio frequency electric fields has been studied by the use of a stripline, in which whole body exposure to vertical electric fields (3,27 MHz) can be produced. We have examined two different techniques to measure the induced current; parallel plate meters and current probes. When the subject has good connection to the ground, the choice of measurement technique is not crucial, since there are only minor differences in readings between the instruments. But when the subject is wearing shoes and/or standing on a wooden plate, the difference between the instruments increases considerably. The difference can mainly be explained by the capacitive coupling between the parallel plate meters and the ground; therefore, the current probes are preferred when the subject does not have perfect contact with the ground. Since the International Commission on Non-Ionizing Radiation Protection guidelines demand measurements of induced current in humans exposed to radio frequency fields in the range of 10,110 MHz, the importance of finding an appropriate measurement procedure becomes apparent. Bioelectromagnetics 22:560,567, 2001. © 2001 Wiley-Liss, Inc. [source] | ||||||||||