Applications of Electron Spin Resonance Spectrometry for Reactive Oxygen Species and Reactive Nitrogen Species Research

Electron spin resonance (ESR) spectroscopy has been widely applied in the research of biological free radicals for quantitative and qualitative analyses of reactive oxygen species (ROS) and reactive nitrogen species (RNS). The ESR spin-trapping method was developed in the early 1970s and enabled the analysis of short-lived free radicals. This method is now widely used as one of the most powerful tools for free radical studies. In this report, some of the studies that applied ESR for the measurement of ROS and RNS during oxidative stress are discussed

Electronic Videoendoscopy of Laryngeal Lesions Using a New Type of Rhinolarynx Endoscope Portion

Patients with laryngeal lesions were observed and the lesions were recorded with an electronic videoendoscope system using the PENTAX EPM-3300 video processor and the PENTAX VNL-1330 endoscope portion. The electronic videoendoscope system differs from the conventional fiberoptic endoscope connected to a video camera in that a small monochrome charge-coupled device (CCD) chip is built in the tip of the endoscope portion. The PENTAX VNL-1330 rhinolarynx endoscope portion has a tip and insertion tube of approximately 4mm in outer diameter to allow its introduction through the nasal passages into the larynx. The dynamic color images provided by this system were superior to those obtained by a conventional rhinolarynx flexible fiberscope connected to a video camera in both quality and resolution of detail. This system should be useful in diagnosing laryngeal lesions

Squamous Cell Carcinoma With Sarcomatous Stroma of the Mesopharynx

A case of squamous cell carcinoma with sarcomatous stroma of the mesopharynx is presented. The patient was a 62-year-old man who complained of a foreign body sensation. Endoscopic examination revealed a large pedunculated mass arising from the posterior wall of the mesopharynx. The lesion was surgically resected, using a cutting snare by the endo-oral approach, and was completely removed. A diagnosis of squamous cell carcinoma with sarcomatous stroma was made histopathologically. The clinicopathological features of this case are described and compared with those of previously reported cases

Clinical Experience With a New Type of Rhino-Larynx Electronic Endoscope PENTAX VNL-1530

We observed recordings of pictures obtained from patients with diseases of the larynx by using a new type of rhino-larynx electronic endoscope, PENTAXVNL-1530 connected to a video processor, PENTAX EPM-3300 (Asahi Optical Co., Ltd.). The electronic endoscope differs from the fiberoptic endoscope in that it contains a small light-sensitive charge coupled device (CCD) chip that is attached to the tip of the endoscope. This electronic endoscope has the smallest CCD camera of 5.1 mm in diameter, in the tip portion, and can be passed through the nasal passage into the laryngeal cavity. The dynamic image provided by this system is superior to that obtained by a flexible laryngofiberscope in resolution of the detail

Scavenging or Quenching Effect of Melanin on Superoxide Anion and Singlet Oxygen

Although photoprotective properties of skin melanin have been well documented, a few studies on the effect of melanin on reactive oxygen species (ROS) generated by ultraviolet (UV) irradiation have been reported. To study the interaction of melanin with ROS, scavenging or quenching effect of melanin on O2•− and 1O2 was examined by electron spin resonance (ESR)-spin trapping methods and a spectrophotometric method, respectively. Melanin potently interacted with O2•− generated in a hypoxanthine (HPX)-xanthine oxidase (XOD) reaction, and with 1O2 generated from a peroxidase, H2O2, and halide system. In the HPX-XOD reaction, it was proved that melanin doses not interfere with the enzyme reaction. It is confirmed that one of the mechanisms by which melanin protects UV-induced skin damage is likely scavenging or quenching activity against ROS such as O2•− and 1O2

Verrucous Carcinoma of the Larynx Presenting as a Hairy Whitish Tumor

A patient was encountered with verrucous carcinoma of the larynx that presented as a hairy whitish tumor. There was a recurrence because simple excision with forceps by endolaryngeal microsurgery was performed in the first operation. However, in the second operation endolaryngeal microscopic laser surgery using a direct laryngoscope was performed and followed by adjuvant chemotherapy with oral UFT, a combination of uracil and tegafur in a molar ratio of 4:1. The patient’s course has been favorable to date. The case is reported in this paper and discussed from the viewpoint of diagnosis and treatment of this neoplasm

Initial Experience of Endoscopic Phonosurgery With a Prototype of the Therapeutic Rhinolarynx Electronic Endoscope

We performed endoscopic phonosurgery in a patient with a laryngeal lesion using a prototype of the therapeutic rhino-larynx electronic endoscope connected to a video processor (Asahi Optical Co., Ltd.). This therapeutic electronic endoscope differs from the fiberoptic endoscope, because it contains an instrument channel and a miniature television camera attached to the tip of the endoscope, consisting of a small light-sensitive CCD chip. The dynamic image provided by this system is superior in resolution to that obtained by conventional flexible laryngofiberscopes. Using this therapeutic electronic endoscope and flexible forceps, we succeeded in removing a vocal fold polyp. This endoscope can be passed through the nasal passage into the laryngeal cavity. The therapeutic electronic endoscope is introduced and a clinical case is presented

Generation Mechanism of Radical Species by Tyrosine-Tyrosinase Reaction

Alleviated melanin formation in the skin through inhibition of tyrosine-tyrosinase reaction is one of the major targets of cosmetics for whitening ability. Since melanin has a pivotal role for photoprotection, there are pros and cons of inhibition of melanin formation. This study applying electron spin resonance (ESR)-spin trapping method revealed that •H and •OH are generated through tyrosine-tyrosinase reaction. When deuterium water was used instead of H2O, the signal of 5,5-dimethyl-1-pyrroline N-oxide (DMPO)-H (a spin adduct of DMPO and •H) greatly decreased, whilst DMPO-OH (a spin adduct of DMPO and •OH) did not. Thus, it is suggested that •H was derived from H2O, and •OH through oxidative catalytic process of tyrosine to dopaquinone. Our study suggests that tyrosinase inhibitors might contribute to alleviate the oxidative damage of the skin by inhibiting •OH generation via the enzyme reaction

Lymphoepithelial Cyst of the Hypopharynx

A rare case of lymphoepithelial cyst formed in the piriform sinus of the hypopharynx is reported. Histopathological examination revealed a lymphoepithelial cyst. It was removed by laryngomicrosurgical technique using a side-opened direct laryngoscope. Because this cyst was wide-based on the antero-medial region in the right piriform sinus of the hypopharynx, the mucous membrane around the cyst was incised electrosurgically and then detached to facilitate removal. In this paper, we describe our surgical procedure for removing the cyst in this case and discuss the possible causes of the disease