China
Africa
Explore chapters and articles related to this topic
Biological Effects of Millimeter and Submillimeter Waves
Published in Ben Greenebaum, Frank Barnes, Biological and Medical Aspects of Electromagnetic Fields, 2018
Stanislav I. Alekseev, Marvin C. Ziskin
The histological and molecular changes in the skin of 8-week-old male C57BL/6 mice exposed to an fs-pulsed THz beam were studied by Jo et al. (2014). The skin on the back of mice was exposed to 3-THz radiation with a pulse width of <200 fs and a repetition rate of 1 kHz for 1 h. The THz pulse energy was about 0.26 nJ/pulse. Accumulated energy in the exposed area (1 cm2) for 1 h was ~1.15 J/cm2. Skin biopsy samples were taken at 1 and 24 h after exposure. No histological changes were found in either 1 or 24 h post-exposure samples. The authors did not find any inflammatory cells or damaged skin cells such as sunburn cells. The collagen fibers in the dermis were also normal. A microarray analysis revealed that some genes in the exposed skin samples were either biologically activated or suppressed. For instance, the gene transcription of substance P, which is involved in local inflammation, decreased while the transcription of calcitonin gene-related peptide, another neuropeptide that is associated with neurogenic inflammation in eczema, increased significantly. These results are at variance with the histological data. The authors did not provide any explanation for these effects. Any information about the temperature elevation in the exposed skin is also missing.
Magnetic Materials for Nuclear Magnetic Resonance and Magnetic Resonance Imaging
Published in Sam Zhang, Dongliang Zhao, Advances in Magnetic Materials, 2017
Elizaveta Motovilova, Shaoying Huang
Until 2006 GBCAs were considered as one of the safest CAs used in humans [37]. Over 200 million patients have been exposed to gadolinium since the late 1980s. Worldwide post-marketing surveillance studies have all demonstrated that nearly all drug reactions can be characterized as very mild (<2.5%) or moderately severe (<0.02%) [38]. However in 2006 Grobner et al. reported about the possible association between GBCAs and a new and rare disease, NSF [39]. NSF was first described in the medical literature in 2000. NSF causes fibrosis of the skin, connective tissues like muscles, tendons, ligaments, and blood vessels throughout the body, leading to a thickening of the skin and severe decreasing of joints mobility. However, NSF has been reported only in patients with pre-existing chronic kidney disease and end-stage kidney disease. Due to the weak kidney function, the human body cannot clear itself of GBCAs and the extended presence of gadolinium may lead to irreversible health problems, possible confinement to a wheelchair, and even death. Table 3.7 shows an overview of worldwide unconfounded NSF cases for various GBCAs. A retrospective study with Omnisan in about 370 patients with severe renal insufficiency estimated the risk of NSF to be 4% [40]. It is still unknown what causes NSF, there is no cure for it so far, and skin biopsy is the only true means of diagnosis.
Fluorescent Technology in the Assessment of Metabolic Disorders in Diabetes
Published in Andrey V. Dunaev, Valery V. Tuchin, Biomedical Photonics for Diabetes Research, 2023
Elena V. Zharkikh, Viktor V. Dremin, Andrey V. Dunaev
The first study on noninvasive assessment of AGE accumulation by skin fluorescence levels was published in 2004 by Meerwaldt et al. [31]. To validate skin fluorescence as a tool capable of assessing AGE accumulation in DM, the authors performed noninvasive measurements in conditionally healthy volunteers and patients with DM, comparing results with AGE concentration in biopsy specimens (of both fluorescent and nonfluorescent AGE) from the same patients. The study showed a high correlation of skin autofluorescence measurement results with collagen-linked fluorescence in biopsy specimens of the same subjects. Figure 9.2 shows the correlation analysis of skin autofluorescence with collagen-linked (a) and pentosidine (b) fluorescence of skin biopsy specimens [31].
Recent advances in nanotechnology based combination drug therapy for skin cancer
Published in Journal of Biomaterials Science, Polymer Edition, 2022
Shweta Kumari, Prabhat Kumar Choudhary, Rahul Shukla, Amirhossein Sahebkar, Prashant Kesharwani
Diagnoses of skin cancer starts with a medical history, local examination of skin, dermatoscopy, high frequency ultrasonography and histopathological examination with surgical biopsy (Figure 3). Dermatoscopy is a noninvasive method, it refers to the examination of skin using skin surface microscopy (lens system) and a strong light source which is useful in distinguishing typical skin cancerous changes and is also called as ‘epiluminoscopy’ and ‘epiluminescent microscopy’. Dermatoscopy is mainly used for the evaluation of pigmented skin lesions. In, experienced hands, it is easier to diagnose melanoma. Dermatoscopy is helpful in diagnosing basal cell cancer in addition to skin inspection [31]. With both melanoma and non melanoma skin cancer, the diagnostic confirmation of a suspected lesion is done with the help of skin biopsy and histopathological examinations. The biopsy of the lesion is done by doing excision of 2–5 mm of healthy skin and is accomplished either using punch or shave biopsy. The treatment is decided on the basis of size and the anatomical site of the tumour.