Amperometric detection studies of Nafion/indium hexacyanoferrate film for the determination of electroinactive cations in ion chromatography

An amperometric detector based on the chemical modification of Nafion and indium (III) hexacyanoferrate (II, III) thin film (Nafion/In-CN-Fe) onto a glassy carbon (GC) electrode, was first successfully used for the determination of electroinactive cations (Li+, Na+, K+, Rb+, Cs+, NH4+) in single column ion chromatography (IC). A set of well-defined peaks of electroinactive cations was obtained. The detection limits of the cations are 8.9 x 10(-6) mol/L for Li+, 2.3 x 10(-6) mol/L for Na+, 5.2 x 10(-6) mol/L for K+, 4.8 x 10(-6) mol/L for Rb+, 4.0 x 10(-6) mol/L for Cs+ and 5.3 x 10(-6) mol/L for NH4+ at a single-to-noise ratio of 3. The proposed method was quick, sensitive and simple. The cations in rainwater and mineral water were successfully analyzed by this method.

Molecular design of antibrowning agents

Tyrosinase inhibitory and antioxidant activity of gallic acid and its series of alkyl chain esters were investigated. All inhibited the oxidation of L-3,4-dihydroxyphenylalanine (L-DOPA) catalyzed by mushroom tyrosinase. However, gallic acid and its short alkyl chain esters were oxidized as substrates yielding the colored oxidation products. In contrast, the long alkyl chain esters inhibited the enzyme activity without being oxidized. This indicates that the carbon chain length is associated with their tyrosinase inhibitory activity, presumably by interacting with the hydrophobic protein pocket in the enzyme. On the other hand, the esters, regardless their carbon chain length, showed potent scavenging activity on the autoxidation of linoleic acid and 1,1-diphenyl-2-p-picryhydrazyl (DPPH) radical, suggesting that the alkyl chain length is not related to the activity. The effects of side-chain length of gallates in relation to their antibrowning activity are studied.

Protection of mitochondrial functions against oxidative stresses by isoflavans from Glycyrrhiza glabra

Isoflavan derivatives, glabridin (1), hispaglabridin A (2), hispaglabridin B (3), 4'-Omethylglabridin (4) and 3'-hydroxy-4'-O-methylglabridin (5), isolated from Glycyrrhiza glabra, were investigated for their ability to protect liver mitochondria against oxidative stresses. Mitochondrial lipid peroxidation linked to respiratory electron transport and that induced non-enzymatically were inhibited by these isoflavans. Hispaglabridin A (2) strongly inhibited both peroxidations and 3'-hydroxy-4'-O-methylglabridin (5) was the most effective at preventing NADH-dependent peroxidation. 3'-Hydroxy-4'-O-methylglabridin (5) protected mitochondrial respiratory enzyme activities against NADPH-dependent peroxidation injury. Dihydroxyfumarate-induced mitochondrial peroxidation was also prevented by this isoflavan. Isoflavans from G. glabra were shown to be effective in protecting mitochondrial function against oxidative stresses.

Determination of rare earth elements in human blood serum by inductively coupled plasma mass spectrometry after chelating resin preconcentration

The determination of all rare earth elements (REEs) in human blood serum by inductively coupled plasma mass spectrometry (ICP-MS) was performed with the aid of chelating resin (Chelex 100) preconcentration after acid digestion with HNO3 and HClO4. When chelating resin preconcentration was carried out at room temperature, the recoveries of heavy REEs were lower than those of light REEs because of their stable complex formation with residual organic compounds remaining in the digested serum solution. These problems were overcome by heating the solution at 80 degrees C during the chelating resin preconcentration process. As a result, the recoveries for all REEs were improved to 92-102% in the case of a concentration factor of 4, where the analytical detection limits for REEs were below 0.2 x 10(-12) g ml-1. Consequently, all REEs in individual human blood sera collected from five healthy volunteers could be determined by ICP-MS with good precision. The concentrations of REEs in human blood serum were extremely low, in the range from ca. 1 x 10(-12) g ml-1 of Eu to ca. 230 x 10(-12) g ml-1 of Ce.

Speciation of protein-binding zinc and copper in human blood serum by chelating resin pre-treatment and inductively coupled plasma mass spectrometry

A method for the speciation of zinc and copper binding with proteins in human serum was explored by chelating resin (Chelex-100) pre-treatment and inductively coupled plasma mass spectrometry (ICP-MS). It was shown by a SEC (size-exclusion chromatography)-ICP-MS system that albumin-zinc and albumin-copper (loosely-bound species) could be selectively removed from serum by adsorption on the Chelex-100 resin after the chelating resin pre-treatment, while alpha 2-macroglobulin-zinc and ceruloplasmin-copper (firmly-bound species) remained in the serum. The zinc and copper bound with alpha 2-macroglobulin and ceruloplasmin, respectively, were then determined by ICP-MS after batch treatment of the serum samples with the Chelex-100 resin. In addition, the total concentrations of zinc and copper were also determined by ICP-MS after a 20-fold dilution with 0.1 M HNO3. The albumin-zinc and -copper were estimated as the differences between the concentrations of total and firmly-bound species. The present batch pre-treatment method was applied to the speciation analysis of zinc and copper binding with proteins in sera donated from 25 healthy volunteers as well as from a pregnant woman and a myelodysplastic syndrome patient. The observed concentrations of alpha 2-macroglobulin-zinc and ceruloplasmin-copper were in the ranges 109-202 ng ml-1 (12.4-31.3% of total zinc) and 513-880 ng ml-1 (90.6-99.7% of total copper), respectively. The present method is simple (only addition of the chelating resin and centrifugation is required) and reproducible (average RSD = 2% for alpha 2-macroglobulin-zinc and 1% for ceruloplasmin-copper in intra-assay measurements, and 5% for alpha 2-macroglobulin-zinc and 4% for ceruloplasmin-copper in inter-assay measurements), and there is less risk of contamination during separation.

Progressive sensorineural hearing impairment in professional fishery divers

There have been many reports of a high rate of hearing impairment in divers. A prospective study was performed to determine whether sensorineural hearing acuity in the same divers deteriorated faster than in a normal population as they continued diving. After an observation period of approximately 5 years, audiometric examination was performed on a group of professional fishery divers who had normal hearing or sensorineural hearing loss at the time of initial study. Thirty-three ears of 18 divers were included in statistical analyses. The average hearing deterioration in the divers in 5 years, after elimination of the aging effect, was 6.6 dB (SD 4.5) and was statistically significant. We concluded that the hearing acuity of our subjects deteriorated faster than that of normal Japanese.

Antimicrobial triterpenes from Ilex integra and the mechanism of antifungal action

Antimicrobial triterpenes were isolated from the fruits of Ilex integra. Their structures were elucidated by spectral data and identified as rotundic acid (1), ulsolic acid (2) and peduncloside (3). Triterpene 1 showed significantly broad antimicrobial activity against bacteria, yeast and filamentous fungi. The antifungal activity of 1 was reversed by fatty acids. Cellular constituents leaked from Candida albicans cells incubated with triterpene 1. These results suggest that the antimicrobial activity of triterpenes in I. integra is due to a change of membrane permeability arising from membrane lipid alteration.

Direct injection determination of theophylline and caffeine in blood serum by high-performance liquid chromatography using an ODS column coated with a zwitterionic bile acid derivative

An ODS column dynamically coated with zwitterionic bile acid derivative, 3-[(3-cholamidopropyl)-dimethylammonio]-1-propanesulfonate (CHAPS), was evaluated for direct injection determination of drugs in blood serum by HPLC. Polar functional groups such as sulfonate, ammonium and the three hydroxyl groups in CHAPS protruding towards an aqueous mobile phase formed a hydrophilic layer over the ODS reversed-phase surface, which resulted in high molecular mass compounds such as proteins being prevented from penetrating into the internal hydrophobic region. The bulk of the proteins were eluted as an unretained or nearly unretained band by using 0.2 mM sodium hydrogenphosphate solution (pH 7.4) as the mobile phase. In contrast, small molecules such as some inorganic anions and aromatic compounds were retained and thereby separated from one another. It was confirmed that the ODS column modified with CHAPS acts as a restricted access-type column with a hydrophobic interior and a hydrophilic exterior. Hence biological fluids could be directly injected into the CHAPS-coated ODS column. The present HPLC system using the CHAPS-coated ODS column was applied to the determination of theophylline and caffeine in human blood serum. The detection limits for the two drugs with UV absorption at 273 nm were 0.2 and 0.5 mg l-1 (injection volume 20 microliters) and the relative standard deviations of peak area measurements were < 1.4% and 2.2%, respectively, for 10 replicate measurements of serum spiked with 5 mg l-1 of each of the drugs.

Mode of antibacterial action of retrochalcones from Glycyrrhiza inflata

Licochalcone A-D and echinatin, retrochalcones isolated from the roots of Glycyrrhiza inflata, showed antimicrobial activity. Among them, licochalcone A and C had potent activity against some Gram-positive bacteria. These retrochalcones inhibited oxygen consumption in susceptible bacterial cells. The oxidation of NADH in bacterial membrane preparations was also inhibited by them. NADH-cytochrome c reductase was inhibited by licochalcones, while cytochrome c oxidase was not. NADH-CoQ reductase and NADH-FMN oxidoreductase were not inhibited. The site of respiratory inhibition of licochalcones was thought to be between CoQ and cytochrome c in the bacterial respiratory electron transport chain.

Antioxidative and superoxide scavenging activities of retrochalcones in Glycyrrhiza inflata

Licochalcone A, B, C, D and echinatin, retrochalcones isolated from the roots of Glycyrrhiza inflata (licorice), along with an ordinary chalcone isoliquiritigenin, were assessed for their inhibitory activities on lipid peroxidation in various systems and radical scavenging activity. Among those tested, licochalcones B and D strongly inhibited superoxide anion production in the xanthine/xanthine oxidase system. These two compounds also showed potent scavenging activity on DPPH radical. Microsomal lipid peroxidation induced by Fe(III)-ADP/NAPDH was inhibited almost completely by 3 micrograms/ml of licochalcones B and D. Mitochondrial lipid peroxidation induced by Fe(III)-ADP/NADH was more sensitive to these retrochalcones; almost complete inhibition was observed at 10 micrograms/ml of all retrochalcones tested. Licochalcones B and D scavenged superoxide anion in microsome. Furthermore, these retrochalcones protected red cells against oxidative hemolysis. These phenolic compounds were shown to be effective to protect biological systems against various oxidative stresses.

An inhibitor of aldose reductase and sorbitol accumulation from Anthocepharus chinensis

A flavonoid glycoside was isolated from Anthocepharus chinensis. Its structure was elucidated by spectral data and determined to be myricetin 3-O-(4"-acetyl)-alpha-fucoside. This flavonoid glycoside and its aglycone showed potent inhibition against rat and porcine lens aldose reductase. The flavonoid aglycone also inhibited sorbitol accumulation in human red blood cells.

[A 10-year-old case with idiopathic oculomotor nerve palsy]

We reported a 10-year-old girl with acquired left oculomotor nerve palsy. Neurologic and radiological examinations failed to reveal the etiology. Following administration of corticosteroid and vitamin B6, diplopia improved within 6 weeks, and mydriasis has been improving over the past 9 months. Idiopathic acquired oculomotor nerve palsy is a very rare condition in childhood, and prognosis of the disease is sometimes good.

Single-trial analysis of P3 in patients with generalized epilepsy

The latencies and amplitudes of averaged P3, and the latencies, amplitudes and frequency components of single EEG responses to target tones were analyzed in 9 control subjects (CS group), 6 epileptics whose mean IQ was 100 (EP group) and 6 epileptics whose mean IQ was 52 (RE group), using an auditory oddball task. All of the subjects responded to the target tones correctly and there were no differences in the incidence of error in response to the target tones, or in the latencies and amplitudes of the averaged P3 among the three groups. However, the reaction times (RTs) in the RE group were significantly longer than those in the other groups (P < 0.05). Single EEG responses to target tone (single-trial ERPs) were classified into 2 types, those with and those without the P3 component. Type 1 had the P3 component and was observed in 42% of all of the responses in the RE group, significantly less than those in the CS (64%) and EP (61%) groups. The peak latencies of P3 in type 1 were similar among the three groups, but the amplitudes of P3 in type 1 in the RE group were significantly greater than those in the CS and EP groups. RTs in the RE group were significantly longer than those in the other groups, and had no correlation with the P3 latencies of type 1. There was little difference in the results of the frequency analysis among the three groups. These results suggest that all subjects in three groups recognized the target tones correctly, but they did not evaluate every target tone, since the incidence of P3 was almost 60% in the CS and EP groups, and 40% in the RE group. The characteristics of cognition and evaluation in three groups were the same, but the decrease in incidence of evaluation and the dissociation between the cognition and the response execution might be caused by impairment of the subject-environment contact mechanism, which resulted in the decrement of IQ in the RE group.

Clinical global measures of dementia. Position paper from the International Working Group on Harmonization of Dementia Drug Guidelines

Following is the report of the committee working on clinical global measures for antidementia drug guidelines. The concepts involved in global scales, the distinctions between change and severity scales, advantages and disadvantages of structured interviews, and anchoring of change scores are discussed, and selected existing clinical global scales are described. In addition, the committee assessed the utility of global scales in clinical trials for antidementia drugs. There was a consensus among the members of the working group on the following: (1) Clinical global scales are interview based; in most cases, they include information obtained from caregivers as well as directly from patients, but they can rely on information from the subject only. (2) Clinicians' global ratings are intended to assess clinically meaningful change based on multidimensional clinical assessment and take into account the clinical heterogeneity of dementia by assessing at least cognition, behavior, and functioning. (3) There are two distinct types of clinical global measures: (a) clinicians' interview-based global severity scales, which generally incorporate classification by stage or severity of illness and (b) clinicians' interview-based global change scales, which incorporate global assessment ratings of clinical change. The committee could not reach a consensus on whether global scales should be required in phase II and phase III clinical trials, or whether other specific assessments such as well-designed activities of daily living, cognition, and behavior measures could, when used in appropriate combinations, replace the global as assessments of clinical meaningfulness.

Vestibular schwannoma showing a dural tail on contrast-enhanced magnetic resonance images

The dural tail on contrast-enhanced magnetic resonance (MR) images, frequently observed in meningiomas, has been used to distinguish between cerebellopontine angle meningiomas and vestibular schwannomas. We report on a 66-year-old female with vestibular schwannoma showing the dural tail on contrast-enhanced MR images. Histological examination revealed that the dural tail corresponded to the thickened dura mater comprising of collagen fibres and scattered hyalinization with no tumoral invasion.

Antioxidative action of diterpenoids from Podocarpus nagi

Diterpenoids, totarol (1), totaradiol (2), 19-hydroxytotarol (3), totaral (4), 4 beta-carboxy-19-nortotarol (5), sugiol (6), isolated from Podocarpus nagi, were evaluated as antioxidants. Microsomal lipid peroxidation induced by Fe(III)-ADP/NADPH and mitochondrial lipid peroxidation induced by Fe(III)-ADP/ NADH were inhibited by these terpenoids. They inhibited linoleic acid autoxidation but not generation of superoxide anion. Totarol (1) protected mitochondrial respiratory enzyme activities against NADPH induced oxidative injury. Totarane diterpenes from P. nagi were shown to be effective to protect biological systems and function against various oxidative stresses.

Antioxidative constituents in Heterotheca inuloides

Sesquiterpenoids, 7-hydroxy-3,4-dihydrocadalin and 7-hydroxycadalin, and flavonoids, quercetin, kaempferol and their glycosides, isolated from Heterotheca inuloides (Asteraceae), a Mexican medicinal plant known as "arnica", were evaluated as antioxidants. These compounds showed potent scavenging activity on diphenyl-p-picrylhydrazyl (DPPH) radical. Microsomal lipid peroxidation induced by Fe(III)-ADP/NADPH was inhibited by both terpenoids and flavonoids, though only flavonoids possessed superoxide anion scavenging activity in microsome. Flavonoids also scavenged enzymatically and non-enzymatically generated superoxide anion. On the other hand, mitochondrial lipid peroxidation induced by Fe(III)-ADP/NADH was inhibited only by sesquiterpenoids. Furthermore, these terpenes protected mitochondrial enzyme activity against oxidative stress. These results showed that two types of antioxidants existed in the dried flower of H. inuloides and would contribute to protection of tissues against various oxidative stresses.

Inhibition of aldose reductase and sorbitol accumulation by astilbin and taxifolin dihydroflavonols in Engelhardtia chrysolepis

Dihydroflavonol taxifolin and its glycoside, astilbin, from Engelhardtia chrysolepis inhibited rat lens and recombinant human aldose reductase. Taxifolin also inhibited sorbitol accumulation in human red blood cells. Furthermore, this dihydroflavonol aglycone maintained the clarity of rat lens incubated with a high concentration of glucose. These dihydroflavonols may be effective for preventing osmotic stress in hyperglycemia.

Antiperoxidative activity of neolignans from Magnolia obovata

Honokiol and magnolol, neolignans in Magnolia obovata, have been evaluated as antioxidants. Microsomal lipid peroxidation induced by Fe(III)-ADP/NADPH and mitochondrial lipid peroxidation induced by Fe(III)-ADP/NADH were inhibited by these compounds. These neolignans protected mitochondrial respiratory chain enzyme activity against NADPH-induced peroxidative stress and protected red cells against oxidative haemolysis. The anti-oxidative activity of honokiol was more potent than that of magnolol. Neolignans in M. obovata were shown to be effective in protecting biological systems and functions against oxidative stress.

Respiratory stimulation and generation of superoxide radicals in Pseudomonas aeruginosa by fungal naphthoquinones

The mechanism of action of antimicrobial naphthoquinones from the fungus Fusarium was studied by using Pseudomonas aeruginosa. Bostricoidin, methyl ether fusarubin, and fusarubin stimulated the oxygen consumption of bacterial cells and induced cyanide-insensitive oxygen consumption. These activities of the tested compounds were also observed in bacterial membrane preparations in a dose-dependent manner. Naphthoquinones stimulated the generation of superoxide anion and hydrogen peroxide. The naphthoquinone effectively acted as the electron acceptors for bacterial diaphorase, which could explain the antibacterial activity of Fusarium naphthoquinones since electron acceptors lead to the stimulation of respiratory activity and the generation of oxygen radical species.

Primary localized nodular tongue amyloidosis associated with Sjögren's syndrome

We describe a case of primary localized nodular tongue amyloidosis associated with Sjögren's syndrome in a 62-year-old woman. The presence of Sjögren's syndrome was confirmed both serologically and histologically. The amyloid tumor, which was marginally excised, recurred 3 years later and was re-excised. Immunohistochemical examination revealed that the amyloid protein was of the AL (lambda-light chain) type. Infiltration of plasma cells was observed around the minor salivary glands of the tongue surrounded by amyloid. The relationship between the plasma cells and amyloid deposition is discussed.

Cytotoxic and antioxidative sesquiterpenoids from Heterotheca inuloides

Four sesquiterpenoids, beta-caryophyllene, beta-caryophyllene 4,5 alpha-oxide, 7-hydroxy-3,4-dihydrocadalin, and 7-hydroxycadalin, isolated from the dried flower of Heterotheca inuloides Cass. (Asteraceae), have been found to exhibit cytotoxic activity against several solid tumor cell lines. Among them, 7-hydroxy-3,4-dihydrocadalin and 7-hydroxycadalin have also been found to inhibit autoxidative and microsomal lipid peroxidation.