Light exposure induces equivalent phase shifts of the endogenous circadian rhythms of circulating plasma melatonin and core body temperature in men.

Release of melatonin into the circulation by the pineal occurs almost exclusively during the nighttime hours. It has been proposed that this daily rhythm, like that of body temperature, reflects the output of a central circadian pacemaker in humans. In order to investigate the relationship of the circadian rhythms of body temperature and melatonin in humans and compare their resetting responses to light, we characterized the endogenous 24-h profiles of these rhythms in eight young male adults during constant routines before and after exposure to a stimulus consisting of bright light, room light, and darkness/sleep. We found that the time of the fitted maximum of the endogenous melatonin rhythm consistently preceded the fitted temperature minimum by a mean +/- SE of 1.8 +/- 0.2 h. Bright-light exposure induced substantial and equivalent phase shifts of the melatonin and temperature rhythms (mean +/- SE difference in the phase-shifting response, 0.03 +/- 0.32 h), and the body temperature and melatonin rhythms thus maintained their usual phase relationship even after light-induced circadian phase inversion. These results are consistent with the hypothesis that the endogenous circadian components of both the plasma melatonin and body temperature rhythms are generated by a single central circadian pacemaker in humans. Furthermore, using the time of the fitted temperature minimum as a reference standard, we found that the fitted maximum of the endogenous 24-h melatonin profile was a more reliable phase marker than the onset of the nocturnal rise of melatonin (F = 4.48; P less than 0.01).     

Orofacial neuralgia associated with a middle cerebral artery aneurysm

Chronic orofacial pain of neuropathic origin can present diagnostic and management dilemmas to dental practitioners and also affects the patient's quality of life. Intracranial aneurysms are a potential cause of stroke (e.g. sub‐arachnoid haemorrhage) that is usually associated with, high rates of mortality and morbidity. A patient who had been previously managed for symptoms of temporomandibular joint disorder (TMD) presented with sharp, shooting pain of moderate intensity. It was precipitated by swallowing, and radiated to the right throat, posterior border of the mandible, ear and temporomandibular joint. Clinical and radiological investigations ruled out odontogenic pain, TMD and other more common types of facial pain. Magnetic resonance imaging revealed a 7 × 6 mm aneurysm in the right middle cerebral artery (MCA) which was subsequently surgically clipped. Interestingly, the facial pain resolved after this procedure. Compression of the insular region of the brain innervated by the trigeminal, glossopharyngeal and vagus nerves provides a plausible explanation for the pain reported. To our knowledge, this is the first case of facial neuralgia associated with an aneurysm in the MCA which emphasizes the importance of a multidisciplinary approach in the diagnosis and management of unusual cases of chronic orofacial pain.     

Neuropathy and the vascular-bone axis in diabetes: lessons from Charcot osteoarthropathy

Emerging evidence from the last two decades has shown that vascular calcification (VC) is a regulated, cell-mediated process orchestrated by vascular smooth muscle cells (VSMCs) and that this process bears many similarities to bone mineralization. While many of the mechanisms driving VSMC calcification have been well established, it remains unclear what factors in specific disease states act to promote vascular calcification and in parallel, bone loss. Diabetes is a condition most commonly associated with VC and bone abnormalities. In this review, we describe how factors associated with the diabetic milieu impact on VSMCs, focusing on the role of oxidative stress, inflammation, impairment of the advanced glycation end product (AGE)/receptor for AGE system and, importantly, diabetic neuropathy. We also explore the link between bone and VC in diabetes with a specific emphasis on the receptor activator of nuclear factor κβ ligand/osteoprotegerin system. Finally, we describe what insights can be gleaned from studying Charcot osteoarthropathy, a rare complication of diabetic neuropathy, in which the occurrence of VC is frequent and where bone lysis is extreme.     

The Colonic Microbiota and Colonic Disease

The colonic ecosystem differs from that in the proximal gut in several important respects. The colonic microbiota represents the largest population of microbes colonizing humans from birth. Constraints on bacterial numbers, composition, and interaction with the host involve not only the innate and acquired immune system, but also the colonic mucin structure. While the microbiota provides beneficial protective, trophic, nutritional, and metabolic signals for the host, it may become a risk factor for disease depending on context and host susceptibility. Technological advances including DNA-based high-throughput compositional analysis have linked changes in the indigenous microbiota with several human diseases. In some instances, these findings have the potential to serve as new biomarkers of risk of disease. In this overview, recent advances are focused upon in relation to irritable bowel syndrome, inflammatory bowel disease, and colon cancer. The possibility that the therapeutic solution to some of these disorders may reside within the microbiota will also be addressed.     

Foreign body removal with fine-nosed forceps and assistance of image intensification

Foreign body removal has been developed as a routine radiology department service. Techniques, indications and hazards are described.