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Sentinel lymph node biopsy of the vulva
Published in Charles F. Levenback, Ate G.J. van der Zee, Robert L. Coleman, Clinical Lymphatic Mapping in Gynecologic Cancers, 2022
Maaike Oonk, Ate G.J. van der Zee
A recent randomized controlled trial by Deken et al. compared standard sentinel node detection with a hybrid tracer ICG-99Tc nanocolloid in 48 patients.32 They found that the percentage of blue sentinel nodes was lower compared with the percentage of fluorescent sentinel nodes (65.3% versus 92.5%, P < 0.001). The rate of successful sentinel node procedures was not different between both groups (92.1% for the standard group, 97.2% for blue dye, P = 0.33). There are several advantages of near-infrared fluorescence imaging over blue dye. First, the penetration depth of the fluorescence emission. Blue dye cannot be seen through the skin or soft tissue, whereas indocyanine green (ICG) has a penetration depth of up to 8 mm. Second, blue dye and has a lower sensitivity for sentinel node detection. Furthermore, blue dye has a small risk of anaphylaxis, which is much lower for ICG.33 On the other hand, near-infrared fluorescence imaging requires a fluorescent camera system, training in near-infrared imaging, and convenience with the technique. Also, there are some shortcomings of this procedure. Because of its molecular size, ICG migrates through the lymph vessels without specificity for the first draining lymph nodes compared to the higher-echelon nodes. Because of this feature, it also induces spillage during surgical manipulation.34 There are only a few contraindications for ICG: iodine allergy (since indocyanine green contains sodium iodide), pregnancy or breastfeeding, liver disease, dialysis or renal failure, and previous anaphylactic reaction.33
Acute Acoustic Trauma and Blast-Related Hearing Loss
Published in Mansoor Khan, David Nott, Fundamentals of Frontline Surgery, 2021
Jameel Muzaffar, Christopher Coulson, Jonathan D. E. Lee, Linda E. Orr
The best mitigation of noise-induced hearing injury is avoidance of exposure. If this is not possible, then appropriate use of personal protective equipment is the next most effective option. Several potential prophylactic and treatment options have been mooted, including a variety of vitamins, antioxidants, and, more recently, near-infrared light. None of these yet have convincing evidence to support their routine use; glucocorticoid steroids have the strongest evidence base for post-exposure treatment of AAT. Some of the rationale for this originated from the treatment of other conditions, such as Idiopathic Sudden Onset Sensorineural Hearing Loss (ISSHL). Current evidence for the treatment of ISSHL suggests intratympanic injection is superior to oral administration of steroid as salvage and as first-line treatment. The authors' own case series has shown very promising initial results for the treatment of AAT, with more than 80% of patients treated showing significant recovery following early ITSI +/− oral steroid treatment.
Engineered Nanoparticles for Drug Delivery in Cancer Therapy *
Published in Valerio Voliani, Nanomaterials and Neoplasms, 2021
Tianmeng Sun, Yu Shrike Zhang, Pang Bo, Dong Choon Hyun, Miaoxin Yang, Younan Xia
Near-infrared (NIR, 700–900 nm) irradiation can penetrate more deeply into soft tissues than UV and visible light without significantly damaging/heating the area of application. The capability of plasmonic nanoparticles to transduce the absorbed NIR light into heat has been used to trigger the release of drug molecules [129]. For example, doxorubicin-loaded Au nanocages could be used for controlled release by irradiation at 808 nm, improving anticancer activity and potentially reducing systemic toxicity [129a]. A brief discussion on this system can be found in Section 6.8. The photothermal effect of Au nanorods upon exposure to NIR irradiation can also cause rapid rise in local temperature, which has been exploited to induce dehybridization of DNA helices conjugated to the surface and thereby release doxorubicin molecules bound to consecutive cytosine–guanine base pairs [129b]. However, inorganic nanoparticles are usually not biodegradable and raise concerns in their potential long-term toxicity [130]. Recently, organic transducers that can convert absorbed NIR light into heat have attracted significant attention [131]. Among them, indocyanine green (ICG), an FDA-approved fluorescent dye, is the most widely used molecule for cancer therapy [132]. For example, PLGA-based nanoparticles loaded with doxorubicin and ICG showed strong temperature responsiveness and faster doxorubicin release under NIR irradiation [133].
Examining Interhemispheric PFC Connectivity during AUD Abstinence with Multilevel Modeling
Published in Alcoholism Treatment Quarterly, 2022
Spencer Bradshaw, Adam Jones, Rebecca Lucero Jones, Sterling Shumway, Thomas Kimball
Functional near-infrared spectroscopy is an imaging technique that is growing in popularity and is used to examine oxygenated (oxy-Hb) and deoxygenated (deoxy-Hb) hemoglobin in the blood through near-infrared light. More specifically, measures of oxy-Hb and deoxy-Hb can be identified through the examination of changes in hemoglobin in the blood. These measures of oxy-Hb and deoxy-Hb cerebral blood flow (CBF) can then be used as assessment measures of neuronal activation that corresponds with brain activity (Ayaz, Shewokis, Bunce, Schultheis, & Onaral, 2009). The popularity of fNIRS has grown given its portability (fNIRS is a very light weight and transportable device), noninvasiveness, low operating cost, high temporal resolution, and robust ability to manage movement artifacts (Ayaz et al., 2006). For some research contexts, these features make fNIRS an affordable alternative to functional magnetic resonance imaging (fMRI).
Progress in tumour-targeted drug delivery based on cell-penetrating peptides
Published in Journal of Drug Targeting, 2022
Xinru Kong, Jiangkang Xu, Xiaoye Yang, Yujia Zhai, Jianbo Ji, Guangxi Zhai
However, owing to the short wavelength of UV light, the penetration in biological tissues is limited and may cause tissue damage, which prevents the use of UV light to treat large or internal tumours [102]. Therefore, the use of UV light for adjustable CPP activity in vivo may be limited. Near-infrared (NIR) can overcome the above-mentioned problems because it has a longer wavelength than UV, can penetrate deeper into living tissue, and cause minimal damage to the application site [103]. Therefore, it is widely used for tumour treatment. Yang et al. [103] temporarily trapped the positively charged lysine residues on CPP using the NIR two-photon excitation protection group (4,5-dimethoxy-2-nitrobenzyl, PG), thereby forming light-sensitive peptides (PSPs) (Figure 8(C)). Once irradiated by NIR light in the tumour tissue, these PGs are cleaved, which restores the positively charged CPP activity, thus promoting the rapid delivery of liposomes to cancer cells. Compared to unmodified liposomes, NIR-activated PSP-L produced higher anti-tumour effects in an MCF-7 tumour nude mouse model.
Influence of extracerebral layers on estimates of optical properties with continuous wave near infrared spectroscopy: analysis based on multi-layered brain tissue architecture and Monte Carlo simulation
Published in Computer Assisted Surgery, 2019
Yan Zhang, Xin Liu, Qisong Wang, Dan Liu, Chunling Yang, Jinwei Sun
Due to the presence of extracerebral layer, the accuracy of near-infrared spectroscopy is degraded due to the difference between the partial optical pathlength and the mean optical pathlength. Thus we adopt Monte Carlo simulations to obtain partial optical pathlength and mean optical pathlength to compensate the partial volume effect. After correcting the partial volume effect, the measured data can be compared with the true value directly for different wavelength and different source-detector spacings. The results indicate the performance of functional near infrared spectroscopy is influenced by the extracerebral layer when we want to know the optical properties of deep layer. However, if the anatomic structure of the brain could be predicted or measured with other technologies, Monte Carlo simulations are a possible way to be implemented to correct the measured data. Therefore, we verified with the in-vitro experiments with five-layered model that the partial volume effect can influence the detection for optical parameters in gray matter and the possible correction method with Monte Carlo simulations.