Akihide Itoh

Clinicoepidemiologic Features of Sudden Deafness Diagnosed and Treated at University Hospitals in Japan

Nationwide epidemiologic surveys were done 3 times by the Research Committee of the Ministry of Health and Welfare in Japan to investigate the number of patients and clinical manifestations of idiopathic sudden sensorineural hearing loss (sudden deafness). The first, second, and third surveys were carried out during the 1970s, 1980s, and 1990s, respectively. For each patient, we have compiled data regarding age, sex, onset day, presence or absence of vertigo, and hearing ability, including initial and final audiograms, in a computer in the Nagoya University Computer Center. Regarding patients who visited university hospitals, complete data were collected for 421 subjects (age: 40.2 ± 15.4 years, female: 203, male: 218) between July 1973 and June 1974, for 813 subjects (age: 45.1 ± 15.4 years, female: 407, male: 406) in 1987, and for 1112 subjects (age: 49.1 ± 16.0 years, female: 591, male: 521) in 1993. The number of patients with sudden deafness treated in university hospitals in Japan has increased, especially in the elderly population. This increase is associated with population increase and age-adjusted incidence rates per 100,000 in the elderly population. The initial and final hearing levels in the first survey were worse than those in the second and third surveys; there was no significant difference in hearing between the second and third surveys. The hearing levels were worse in children and elderly patients than in the other age groups.

Speciation of yttrium and lanthanides in natural water by inductively coupled plasma mass spectrometry after preconcentration by ultrafiltration and with a chelating resin

A combined system of size exclusion chromatography, UV absorption detection and ICP-MS was used for elucidation of the dissolved states of yttrium and lanthanide elements in lake water collected from Lake Biwa, Japan. The lake water samples were filtered with a membrane filter (pore size 0.45 µm) just after filtration with a glass filter (pore size 1.0 µm). The total concentrations of the dissolved lanthanide elements in the filtrate were determined by ICP-MS after chelating resin preconcentration. For speciation analysis, the above filtered water samples were further preconcentrated 30–500-fold with an ultrafiltration filter, which allowed preconcentration of molecules with molecular masses >10000. The preconcentrated sample solution was then subjected to speciation analysis using the above combined system, where a size exclusion column with the molecular permeation range between 1000 and 300000 was used for molecular separation. In the size exclusion chromatograms obtained with UV absorption detection at 254 nm, two peaks of some large organic molecules were obtained at retention times corresponding to molecular masses of >300000 (peak 1) and about 50000–10000 (peak 2). In the chromatograms, which were measured on-line by ICP-MS, yttrium and lanthanide elements (Y, La, Ce and Pr) were found at the two peak positions corresponding to above large organic molecules.

Evaluation of sulfobetaine-type zwitterionic stationary phases for ion Chromatographic separation using water as a mobile phase

Abstract Ion Chromatographic separation of inorganic ions (anions and cations) was investigated by using three kinds of sulfobetaine-type surfactants (CHAPS, C12SB, and C14SB) as the stationary phases, which were coated by hydrophobic adsorption on the ODS column. In the present separation system, pure water was used as a mobile phase. Since the amount of surfactant adsorbed on the ODS surface significantly influenced the retention behaviors of inorganic ions, the amounts of the sulfobetaine-type surfactants adsorbed were estimated by the breakthrough procedure. The maximum amounts of CHAPS, C12SB and C14SB adsorbed were 0.40, 0.87 and 1.08 mmol, respectively. It was elucidated from the chromatograms of inorganic ions that the retention behavior of inorganic anions was directly related to the surface charges arising from the adsorbed surfactants. The large surface charge was effective for the efficient separation of inorganic ions in water elution. In addition, their retention behavior was strongly affected by the hydrophobicity of the adsorbed surfactants as well as the ionic functional groups of the surfactants which produced the charged surface. The elution order of inorganic anions was correlated with the Hofmeister series. This suggests that the hydration energies of the ions play important roles in separation in the water elution system.

Lymphoepithelioma-like carcinoma of the larynx associated with an Epstein-Barr viral infection:

L ymphoepithelioma is a term used to describe undifferentiated squamous cell carcinoma variants of nasopharyngeal neoplasms (WHO type 3). Correlations between lymphoepithelioma and Epstein-Barr virus (EBV) have been investigated with serologic1 and pathologic evaluation.2,3 Recently, nonnasopharyngeal neoplasms, which have morphologic features identical to those of lymphoepithelioma, called lymphoepithelioma-like carcinoma (LEC), have been reported in other anatomic sites.4–10 Seven cases of laryngeal LEC have been reported in the English literature to date, but EBV has yet to be detected in laryngeal LEC. In this article, LEC in the epiglottis of the larynx is described with cellular localization of EBV-encoded immediate-early RNAs (BHLF) in the tumor cells of the larynx. This case report is the first to show laryngeal LEC associated with an EBV infection.

Amperometric detection studies of poly-o-phenylenediamine film for the determination of electroinactive anions in ion-exclusion chromatography

An amperometric detector based on the chemical modification of poly-o-phenylenediamine (P-OPD) on a gold electrode was successfully used for the determination of electroinactive anions (SO42−, Cl−, NO3−, F−, CH3COO− and PO43−) by single-column ion-exclusion chromatography. All of the anions were detected conveniently and reproducibly in a linear concentration range of 1.0 × 10−5–5.0 × 10−3 mol L−1. The detection limits of the anions were 2.10 × 10−6 mol L−1 for SO42−, 2.47 × 10−6 mol L−1 for Cl−, 3.53 × 10−6 mol L−1 for NO3−, 3.41 × 10−6 mol L−1 for F−, 5.82 × 10−6 mol L−1 for CH3COO− and 3.86 × 10−6 mol L−1 for PO43− at a signal-to-noise ratio of 3. The proposed method was successfully applied to the analysis of rainwater and river water samples. The electrode was stable during a 2 week period of operation with no evidence of chemical or mechanical deterioration.

Simultaneous Determination of Silicic Acid, Ca, Mg and Al in Mineral Water and Composite Tablets by Ion Chromatography

SummaryA simple, selective and sensitive ion-chromatography method was investigated for simultaneously determining silicic acid, Ca2+, Mg2+, Al3+ and anions (Cl− and NO3−) in real samples. It involved a single-column ion-chromatograph with sodium hydroxide-methanol-water eluent and conductometric detection. Cations were converted to complex anions by adding EDTA to the sample solution. A set of well-defined peaks of silicic acid, Ca2+, Mg2+, Al3+, Cl− and NO3− were obtained. Detection limits using 3.3σ (σ=standard deviation of blank solution) were 1.25×10−6 M for H3SiO4−, 1.32×10−6 M for Ca2+, 1.28×10−6 M for Mg2+, 1.33×10−6 M for Al3+, 1.31×10−6 M for Cl− and 1.24×10−6 M for NO3−. The method was successfully applied to analysis of mineral water and composite tablets.

A Novel Ion Chromatographic Method Using Zwitterionic Surfactants as the Stationary Phase and Water as the Mobile Phase

Abstract Zwitterionic surfactants immobilized on the surfaces of octadecylsilica (ODS) are used for the stationary phase and water as the mobile phase for the ion chromatography (IC) of target analytes. The creation of an electrical double layer (EDL), when a zwitterionic stationary phase is in contact with the analyte ions, is proposed to explain the separation mechanism. When an EDL is created using a zwitterionic stationary phase (ZWEDL), its properties differ considerably to those of a single charge-fixed stationary phase created EDL. For a ZWEDL, (i) the electrostatic field is increased, resulting in the simultaneous retention and separation of both cations and anions; (ii) the electrostatic affinity between the analytes in the ZWEDL and the stationary phase is extremely weak. This results in the “effective” distribution of the analytes between the stationary phase and the mobile phase without the need for ion-exchange. Since only water is used for the mobile phase, the sensitivity of detection by co...

Simultaneous amperometric detection of electroinactive anions and cations in ion chromatography

An amperometric detector with two working electrodes modified with polydiphenylamine (PDPA) and polydiphenylamine dodecyl sulfate (PDPA-DS) was successfully used for the simultaneous determination of electroinactive anions (SO42−, Cl−, NO3−) and cations (Na+, NH4+ and K+) in single-column ion-exclusion chromatography–cation-exchange chromatography (IEC-CEC). The PDPA-DS chemically modified electrode (CME) was based on the incorporation of dodecyl sulfate (DS) into PDPA by electropolymerization of diphenylamine (DPA) in the presence of surfactant. The electrochemical responses against the anions and cations in differential pulse voltammetry were studied. A set of well-defined peaks of electroinactive anions and cations were obtained. The relative standard deviations (RSDs) of chromatographic peak height (nA) for anions were all <4.4% and those for cations were all <4.1%. The anions and cations were detected conveniently and reproducibly in the linear concentration range 6.0 ×10−6–5.0 × 10−3 mol L−1 and their correlation coefficients were all >0.990. Their detection limits were investigated using 3s (where s represents the standard deviation of a blank solution, n = 11). They were 9.86 × 10−7 mol L−1 for SO42−, 6.92 × 10−7 mol L−1 for Cl−, 7.86 × 10−7 mol L−1 for NO3−, 7.86 × 10−7 mol L−1 for Na+, 9.79 × 10−7 mol L−1 for NH4+ and 8.94 × 10−7 mol L−1 for K+. The recoveries of the anions and cations by this method were in the range 97.8–103%. The proposed method was rapid, sensitive and simple and was successfully applied to the analysis of rainwater samples. Both electrodes were stable during a 1 week period of operation with no evidence of chemical or mechanical deterioration.

Multielement profiling analysis of geochemical and environmental samples by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and inductively coupled plasma-mass spectrometry (ICP-MS)

Simultaneous multielement analysis of geochemical and environmental samples such as rock, sediment, seawater, and lake water have been carried out by inductively coupled plasma atomic emission spectroscopy (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS). In these experiments, some instrumental improvement and sample pretreatment techniques were required to fulfil accurate multielement determination of 30-50 elements for each sample described above. Consequently, it becomes possible to characterize the samples by comparing the profiles of their multielement concentration distributions. Such multielement profiling analysis of various samples may be useful in the research fields such as geochemistry, environmental chemistry, material science and so forth.<<ETX>>