Explore the vast range of titles available.

Many animals use the Earth’s geomagnetic field for orientation and navigation. Yet, the molecular and cellular underpinnings of the magnetic sense remain largely unknown. A biophysical model proposed that magnetoreception can be achieved through quantum effects of magnetically-sensitive radical pairs formed by the photoexcitation of cryptochrome (CRY) proteins. Studies in Drosophila are the only ones to date to have provided compelling evidence for the ultraviolet (UV)-A/blue light-sensitive type 1 CRY (CRY1) involvement in animal magnetoreception, and surprisingly extended this discovery to the light-insensitive mammalian-like type 2 CRYs (CRY2s) of both monarchs and humans. Here, we show that monarchs respond to a reversal of the inclination of the Earth’s magnetic field in an UV-A/blue light and CRY1, but not CRY2, dependent manner. We further demonstrate that both antennae and eyes, which express CRY1, are magnetosensory organs. Our work argues that only light-sensitive CRYs function in animal light-dependent inclination-based magnetic sensing. Exactly how some animals use magnetic fields to navigate is a longstanding puzzle. A study using a new behavioural assay and transgenic butterflies finds the cryptochrome gene necessary for inclination-based magnetic sensing, and shows that both antennae and eyes, which express this gene, are magnetosensory organs.

Although many animals use the Earth’s magnetic field for orientation and navigation 1 , 2 , the precise biophysical mechanisms underlying magnetic sensing have been elusive. One theoretical model proposes that geomagnetic fields are perceived by chemical reactions involving specialized photoreceptors 3 . However, the specific photoreceptor involved in such magnetoreception has not been demonstrated conclusively in any animal. Here we show that the ultraviolet-A/blue-light photoreceptor cryptochrome (Cry) is necessary for light-dependent magnetosensitive responses in Drosophila melanogaster . In a binary-choice behavioural assay for magnetosensitivity, wild-type flies show significant naive and trained responses to a magnetic field under full-spectrum light (∼300–700 nm) but do not respond to the field when wavelengths in the Cry-sensitive, ultraviolet-A/blue-light part of the spectrum (<420 nm) are blocked. Notably, Cry-deficient cry 0 and cry b flies do not show either naive or trained responses to a magnetic field under full-spectrum light. Moreover, Cry-dependent magnetosensitivity does not require a functioning circadian clock. Our work provides, to our knowledge, the first genetic evidence for a Cry-based magnetosensitive system in any animal.

OBJECTIVE:--The purpose of this study was to determine the effect of monochromatic infrared energy (MIRE) on plantar sensation in subjects with diabetic peripheral neuropathy. RESEARCH DESIGN AND METHODS--In this randomized, double-blind, placebo-controlled study, 39 subjects with diabetic peripheral neuropathy completed the 8-week study. Subjects received 30 min of active or placebo MIRE three times a week for 4 weeks. Plantar sensation was tested with monofilaments at the beginning of the study (M1), following 4 weeks of treatment (M2), and after an additional 4 weeks of nontreatment (M3). The number of sites that could sense the 5.07 monofilament was totaled at M1, M2, and M3. Data were analyzed using a special repeated-measures statistic followed by a post hoc Tukey-Kramer test. RESULTS:--The average number of sites that patients could sense the 5.07 monofilament increased for both the active and placebo groups. There were significant gains from M1 to M2 (P < 0.002), no significant gains from M2 to M3 (P = 0.234), and significant gains from M1 to M3 (P < 0.002) for both the active and placebo groups. There were no significant differences between active and placebo groups at any measurement. CONCLUSIONS:--Thirty minutes of active MIRE applied 3 days per week for 4 weeks was no more effective than placebo MIRE in increasing sensation in subjects with diabetic peripheral neuropathy. Clinicians should be aware that MIRE may not be an effective modality for improving sensory impairments in patients with diabetic neuropathy.

Humans are not believed to have a magnetic sense, even though many animals use the Earth's magnetic field for orientation and navigation. One model of magnetosensing in animals proposes that geomagnetic fields are perceived by light-sensitive chemical reactions involving the flavoprotein cryptochrome (CRY). Here we show using a transgenic approach that human CRY2, which is heavily expressed in the retina, can function as a magnetosensor in the magnetoreception system of Drosophila and that it does so in a light-dependent manner. The results show that human CRY2 has the molecular capability to function as a light-sensitive magnetosensor and reopen an area of sensory biology that is ready for further exploration in humans. In animals, cryptochrome proteins are thought to be the detectors of the Earth's magnetic field, but humans have not been shown to posess mangetosensing capabilities. Foley et al . demonstrate that the human cryptochrome protein, CRY2, when expressed in Drosophila melanogaster can mediate magnetoreception in a light-dependent manner.

The aim of this study was to investigate the relationship between simulated solar radiation and thermal comfort. Three studies investigated the effects of (1) the intensity of direct simulated solar radiation, (2) spectral content of simulated solar radiation and (3) glazing type on human thermal sensation responses. Eight male subjects were exposed in each of the three studies. In Study 1, subjects were exposed to four levels of simulated solar radiation: 0, 200, 400 and 600 Wm-². In Study 2, subjects were exposed to simulated solar radiation with four different spectral contents, each with a total intensity of 400 Wm-² on the subject. In Study 3, subjects were exposed through glass to radiation caused by 1,000 Wm-² of simulated solar radiation on the exterior surface of four different glazing types. The environment was otherwise thermally neutral where there was no direct radiation, predicted mean vote (PMV)=0±0.5, [International Standards Organisation (ISO) standard 7730]. Ratings of thermal sensation, comfort, stickiness and preference and measures of mean skin temperature (tsk) were taken. Increase in the total intensity of simulated solar radiation rather than the specific wavelength of the radiation is the critical factor affecting thermal comfort. Thermal sensation votes showed that there was a sensation scale increase of 1 scale unit for each increase of direct radiation of around 200 Wm-². The specific spectral content of the radiation has no direct effect on thermal sensation. The results contribute to models for determining the effects of solar radiation on thermal comfort in vehicles, buildings and outdoors.

Complete or incomplete spinal cord injury (SCI) results in permanent neurological deficits due to the interruption of nerve impulses, causing the loss of motor and sensory function, which leads to a reduction in quality of life. The focus of rehabilitation for such individuals is to improve quality of life and promote functional recovery. Photobiomodulation (PBM) has proved to be promising complementary treatment in cases of SCI. The aim of the present study was to investigate the effects of PBM combined with physiotherapy on sensory-motor responses below the level of the injury and quality of life in individuals with SCI. Thirty participants were randomized for allocation to the PBM group (active PBM + physiotherapy) or sham group (sham PBM + physiotherapy). Physiotherapy was administered three times a week. Sensitivity and motor skills were evaluated using the ASIA impairment scale. Quality of life was assessed using the WHOQOL-BREF questionnaire. The data were analyzed with the level of significance set to 5%. Improvements in sensitivity and an increase in the perception of muscle contraction were found in the active PBM group 30 days after treatment compared with the sham group. The results of the WHOQOL-BREF questionnaire revealed a significant difference in general quality of life favoring the active PBM group over the sham group after treatment. Physiotherapy combined with PBM leads to better sensory-motor recovery in patients with SCI as well as a better perception of health and quality of life. Trial registration identifier: NCT 03031223

We observed visual sensations (VSs) in patients undergoing intensity modulated radiotherapy (IMRT) of the brain without the beam passing through ocular structures. We analyzed this phenomenon especially with regards to reproducibility, and origin. Analyzed were ten consecutive patients (aged 41-71 years) with glioblastoma multiforme who received pulsed IMRT (total dose 60Gy) with helical tomotherapy (TT). A megavolt-CT (MVCT) was performed daily before treatment. VSs were reported and recorded using a triggered event recorder. The frequency of VSs was calculated and VSs were correlated with beam direction and couch position. Subjective patient perception was plotted on an 8x8 visual field (VF) matrix. Distance to the orbital roof (OR) from the first beam causing a VS was calculated from the Dicom radiation therapy data and MVCT data. During 175 treatment sessions (average 17.5 per patient) 5959 VSs were recorded and analyzed. VSs occurred only during the treatment session not during the MVCTs. Plotting events over time revealed patient-specific patterns. The average cranio-caudad extension of VS-inducing area was 63.4mm (range 43.24-92.1mm). The maximum distance between the first VS and the OR was 56.1mm so that direct interaction with the retina is unlikely. Data on subjective visual perception showed that VSs occurred mainly in the upper right and left quadrants of the VF. Within the visual pathways the highest probability for origin of VSs was seen in the optic chiasm and the optic tract (22%). There is clear evidence that interaction of photon irradiation with neuronal structures distant from the eye can lead to VSs.

Background To quantify the development of radiation neuropathy in corneal subbasal nerve plexus (SNP) after plaque brachytherapy, and the subsequent regeneration of SNP micromorphology and corneal sensation. Methods Nine eyes of 9 melanoma patients (ciliary body: 3, iris: 2, conjunctiva: 4) underwent brachytherapy (ruthenium-106 plaque, dose to tumour base: 523 ± 231 Gy). SNP micromorphology was assessed by in-vivo confocal microscopy. Using software developed in–house, pre-irradiation findings were compared with those obtained after 3 days, 1, 4 and 7 months, and related to radiation dose and corneal sensation. Results After 3 days nerve fibres were absent from the applicator zone and central cornea, and corneal sensation was abolished. The earliest regenerating fibres were seen at the one-month follow-up. By 4 months SNP structures had increased to one-third of pre-treatment status (based on nerve fibre density and nerve fibre count), and corneal sensation had returned to approximately two-thirds of pre-irradiation values. Regeneration of SNP and corneal sensation was nearly complete 7 months after plaque brachytherapy. Conclusions The evaluation of SNP micromorphology and corneal sensation is a reliable and clinically useful method for assessing neuropathy after plaque brachytherapy. Radiation-induced neuropathy of corneal nerves develops quickly and is partly reversible within 7 months. The clinical impact of radiation-induced SNP damage is moderate.

In the present study, the gastrocolonic response after ingestion of a standardized liquid meal and the response to a local chemical stimulus were investigated in 10 healthy volunteers and 10 patients with slow-transit constipation (as determined by marker studies). Colonic pressures were recorded while fasting, after ingestion of a standardized meal and after intracolonic bisacodyl infusion, using a 12-channel water-perfused catheter. Pressure waves propagating over at least 20 cm (HAPPW) were identified visually and automated analysis was carried out on remaining segmental motility. Increases of motility after a meal and bisacodyl were seen in healthy subjects, whereas patients did not show these responses. The time until occurrence of the first HAPPW after bisacodyl infusion tended to be prolonged (4.3 +/- 1.4 vs 36.1 +/- 15.3; P = 0.053) and the number of HAPPWs in the first 30 min. after infusion was lower compared to healthy subjects (2.1 +/- 0.2 vs 5.4 +/- 0.3; P < 0.01). The percentage of HAPPWs that were experienced as urge or cramp was significantly lower in constipated patients (53 +/- 3% vs 95 +/- 1%; P < 0.005). In conclusion, this study shows that in patients with slow-transit constipation, the colonic motor response to a meal and to bisacodyl, as well as the perception of bisacodyl-induced propagated pressure waves is decreased.