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Biomedical subjects

Yoshio Suzuki

Publications and source records attributed to Yoshio Suzuki.

At least 37 records · Page 2Linked to original sources
PubMed2004

The capillary electrophoresis separation of benzodiazepine drug using dextran sulfate and SDS as running buffer.

Capillary electrophoresis has been applied the analyses of many clinical drugs due to its rapid, high-resolution separation. In this study, electrokinetic chromatography involving the combination of SDS and dextran sulfate, which are synthetic polymers, was examined in order to obtain high resolution. Use of 2% dextran sulfate (10,000 molecular weight), 20 mm SDS running buffer containing boric acid solution (pH 9.2) and a silica capillary (inner diameter of 75 micro m, effective length of 50 cm, 57 cm overall length) afforded separation of 10 kinds of benzodiazepines. The detection limit was 0.2 micro g/mL; additionally, reproducibilities were de fi ned as the peak height and migration time. The average peak height was 5.92% (2.46-17.61), whereas the average migration time was 0.44% (0.18-0.76; n = 5). This separations system can be applied to the analysis and measurement of other pharmaceuticals as well.

Benzodiazepines↗
PubMed2004

An example of social activities by registered dietitians: development of recipes for cook-chilled meals to be delivered to kidney disease patients in the conservative treatment and maintenance dialysis stages.

BACKGROUND: Many studies have indicated the effectiveness of medical nutrition therapy for kidney diseases in various stages. However, compliance with dietary therapy over a long period is not easy for patients living alone, elderly patients, and disabled patients, and the concern of registered dietitians working at medical facilities has become increased. Our activities started in the form of social services, developing recipes for cook-chilled foods, collaborating with a firm that had been providing a meal-delivery service, for patients with kidney diseases. METHODS: Our subjects were outpatients with renal failure at the conservative treatment stage, patients at the dialysis stage, and those with diabetic nephropathy. To develop recipes, the nutritional amounts of energy, protein, potassium, phosphorus, salt, and water content in the diet were determined on the basis of the guidelines of the Japanese Society of Nephrology. In 2000, a survey was conducted of 140 regular users of the cook-chilled and delivered foods. The items surveyed were: age, sex, duration of the use of the service, degree of satisfaction with the meals, palatability of menu items, opinions and requests, and reasons for the use of the service. RESULTS: Between February 1996 and August 2000, recipes for cook-chilled foods for patients with kidney diseases at the conservative-treatment stage, those at the dialysis stage, and those with diabetic nephropathy were gradually developed. As of July 2003, the total number of recipes was 946. Of the 140 users surveyed, we obtained valid responses from 91 (65.0%). Regarding duration of usage of the service (n = 91): it was 1 year or more in 38.6%, 6-12 months in 15.7%, 3-6 months in 22.9%. 1-3 months in 12.3%, and 1 month or less in 10.8%. Regarding degree of satisfaction with the meals (n = 91), it was very good or good in 58%, fair in 30%, and no good in 12% of respondents. CONCLUSIONS: As the results of the survey indicated, the home-delivered, cook-chilled foods were generally, favorably accepted by users (rate of satisfaction, 58% [very good and good], duration of usage, 54.3% [6 months or longer]), for them to continue their dietary therapy at their homes. It is suggested that the service of delivering cook-chilled meals can be used as one of the choices enabling continued dietary therapy for patients with chronic renal failure who have difficulty in self-management of the diet at home for diverse reasons.

Adult↗
PubMed2004

Melanoidin, a food protein-derived advanced maillard reaction product, suppresses Helicobacter pylori in vitro and in vivo.

BACKGROUND: Extracellular urease proteins located on the surface of Helicobacter pylori are gastric mucin-targeted adhesins, which play an important role in infection and colonization to the host. In this study we have determined the inhibitory activity of a variety of melanoidins, protein-derived advanced Maillard reaction products, ubiquitously found in heat-treated foods, on urease-gastric mucin adhesion. In addition, we have determined the anticolonization effect of melanoidin I, prepared by the Maillard reaction between casein and lactose, in an animal model and in human subjects infected with this bacterium. METHODS: The inhibitory activity of each compound was determined by a competitive binding assay of labeled gastric mucin to plate-immobilized urease. Melanoidin I was used in an in vivo trial using euthymic hairless mice as an infection model. Melanoidin I was consumed for 8 weeks by subjects infected with H. pylori. The [(13)C] urease breath test and H. pylori-specific antigen in the stool (HpSA) test were performed on subjects at week 0 and week 8. RESULTS: A variety of food protein-derived melanoidins strongly inhibited urease-gastric mucin adhesion in the concentration range of 10 micro g/ml to 100 micro g/ml. In particular, melanoidin I significantly (p <.05) suppressed colonization of H. pylori in mice when given for 10 weeks via the diets. Eight weeks daily intake of 3 g melanoidin I significantly (p <.05) decreased the optical density of HpSA in subjects. CONCLUSION: Foods containing protein-derived melanoidins may be an alternative to antibiotic-based therapy to prevent H. pylori that combines safety, ease of administration and efficacy.

Administration, Oral↗
PubMed2004

Design and synthesis of labeling reagents (MS probes) for highly sensitive electrospray ionization mass spectrometry and their application to the detection of carbonyl, alcohol, carboxylic acid and primary amine samples.

Novel labeling reagents, called MS probes, which possess a positively charged quaternary amine moiety and can transform a neutral analyte into a charged compound by simply mixing with the analyte and allowing the mixture to stand from several minutes to 30 min at room temperature or while heating to 50 degrees C, were designed and synthesized for the highly sensitive detection of carbonyl, alcohol, carboxylic acid and primary amine samples by electrospray ionization mass spectrometry (ESI-MS). The positively charged products can be detected with high sensitivity in an ESI-MS system, which is the most popular liquid MS instrument. All of the labeled products showed a remarkably large increase in the molecular-ion peak abundance detection sensitivity of over 500-fold at picomolar concentration levels compared to that of unlabeled analytes in an ESI-MS system. These MS probes, used together with liquid MS detection, are widely applicable as a convenient method for the highly sensitive detection of less than picomolar levels of analytes, and therefore greatly enhance the power of ESI-MS analysis.

Alcohols↗
PubMed2004

[Fluorescent probes for intracellular Mg2+ measurement].

Recently, fluorescent probes are widely used as tools for dynamical measurement of ion distributions and concentrations in cells. They are highly sensitive, and offer imaging by the use of fluorescent microscopy in easily and less cell damaging way. This paper discusses the selectivity and optical character of the three novel Mg(2+) fluorescent probes. KMG-20AM offers ratiometric quantative measurement of Mg(2+), KMG-104 provides high-sensitive qualitative analysis and 3-D measurement. With those improved Mg(2+) fluorescent probes, the physiological and pathological role of Mg(2+) are going to be more and more clear.

Cations, Divalent↗
PubMed2003

Portable sick house syndrome gas monitoring system based on novel colorimetric reagents for the highly selective and sensitive detection of formaldehyde.

Formaldehyde (HCHO) emitted from the furniture and the walls in the rooms injures the eyes, nose, and respiratory organs and causes allergies, which is called sick house syndrome. We designed and synthesized novel colorimetric HCHO-sensing molecules (KD-XA01 and KD-XA02) which possess an enaminone structure and developed a hand-held instrument to monitor indoor HCHO gas with the use of KD-XA01. These sensing molecules produced speedy color changes from colorless to yellow under mild conditions, which was caused by the fact that the enaminone structure in the reagent reacts with HCHO to give a lutidine derivative. This reaction took place not only in the solution phase but also in the solid phase (surface of the cellulose paper). To take advantage of this phenomena, a handy and rapid monitoring system has been developed for detecting indoor HCHO gas using a highly sensitive and selective detection tablet constructed from the porous cellulose paper that contains silica gel as an adsorbent, KD-XA01, and phosphoric acid under optimum conditions. This instrument detected the surface color change of the tablet from white to yellow, which was monitored as a function of the intensity of the reflected light illuminated by an LED (475 nm). The response was proportional to the HCHO concentration at a constant sampling time and flow rate; 0.05 ppm HCHO, which is under the standard value set by the World Health Organization, was able to be detected in 5 min. The detection limit was 0.005 ppm. This monitoring system was not interfered by carbonyl compounds such as acetaldehyde and acetone, alcohols, hydrocarbons, and typical gases such as carbon monoxide, carbon dioxide, nitrogen dioxide, etc., which contributes to the measurement of correct HCHO concentrations. It was possible to monitor the HCHO gas in the room of a new apartment and school using this instrument; the response values were in good agreement with those obtained by the standard DNPH method. This highly sensitive, selective, and handy HCHO gas monitor is widely applicable and convenient for users who are not specialists in this field.

Air Pollution, Indoor↗
PubMed2003

Adenosine 3', 5' cyclic monophosphate attenuates the production of fibronectin in the glomeruli of anti-glomerular basement membrane antibody-associated nephritic rats.

1. Excessive production of extracellular matrix is thought to be involved in the progression of glomerulonephritis and glomerulosclerosis. In chronic glomerulonephritis, fibronectin has been shown to accumulate in the glomeruli, accompanied by cell proliferation. 2. Glomerulonephritis was induced in rats by the injection of anti-glomerular basement membrane antibody. The rats showed proteinuria and histological alterations in the glomeruli. An increase in fibronectin levels in the culture medium of isolated nephritic glomeruli was confirmed, and was associated with the development of nephritis. Immunohistochemical staining demonstrated a marked accumulation of fibronectin in the glomeruli of nephritic rats. 3. Attenuated generation of cyclic AMP was also observed in the nephritic glomeruli treated with forskolin, prostaglandin E1 or adenosine. 4. Forskolin, prostaglandin E2 and 8-bromo-cyclic AMP markedly reduced the production of fibronectin by the nephritic glomeruli compared with controls in a dose-dependent manner. 8-Bromo-cyclic AMP suppressed the production of fibronectin by cultured mesangial cells. 5. These findings suggest that the attenuated generation of cyclic AMP in response to ligands is connected to the augmented accumulation of fibronectin in nephritic glomeruli, and may facilitate the development of methods for treating glomerulonephritis and glomerulosclerosis.

Animals↗
PubMed2003

Na+/Mg2+ transporter acts as a Mg2+ buffering mechanism in PC12 cells.

Mg(2+) buffering mechanisms in PC12 cells were demonstrated with particular focus on the role of the Na(+)/Mg(2+) transporter by using a newly developed Mg(2+) indicator, KMG-20, and also a Na(+) indicator, Sodium Green. Carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone (FCCP), a protonophore, induced a transient increase in the intracellular Mg(2+) concentration ([Mg(2+)](i)). The rate of decrease of [Mg(2+)](i) was slower in a Na(+)-free extracellular medium, suggesting the coupling of Na(+) influx and Mg(2+) efflux. Na(+) influxes were different for normal and imipramine- (a putative inhibitor of the Na(+)/Mg(2+) transporter) containing solutions. FCCP induced a rapid increase in [Na(+)](i) in the normal solution, while the increase was gradual in the imipramine-containing solution. The rate of decrease of [Mg(2+)](i) in the imipramine-containing solution was also slower than that in the normal solution. From these results, we show that the main buffering mechanism for excess Mg(2+) depends on the Na(+)/Mg(2+) transporter in PC12 cells.

Adrenergic Uptake Inhibitors↗
PubMed2003

Neuronal expression of alphaB crystallin in cerebral infarction.

alphaB crystallin (alphaBC) is one of the heat shock proteins that are induced under stressful conditions. In normal brains, alphaBC is present in oligodendrocytes and astrocytes, but not in neurons. Neuronal alphaBC expression in the central nervous system under pathological conditions has been investigated in several previous studies, most of which dealt with various neurodegenerative diseases with and without ballooned neurons. Neuronal expression of alphaBC has seldom been studied in cerebral infarction (CI), and the frequency of alphaBC-positive neurons in the various stages of CI is unknown. To investigate this issue, we examined 48 autopsy brains of patients with CI, and found neuronal expression of alphaBC in 68.8% of the cases. We found three types of alphaBC-positive neurons: normal morphological, convex, and ballooned neurons. Although alphaBC-positive neurons were present in the every stage of CI, they were more frequent later than 10 days after the onset of CI, and the frequency of alphaBC-positive ballooned neurons was particularly increased in the later stages of CI. This may indicate that morphologically normal neurons gradually swelled up through convex neurons, finally forming ballooned neurons. Previous studies indicated that alphaBC might have a cytoprotective function as a molecular chaperone, and we speculate that alphaBC is expressed in neurons subjected to ischemic stress, and exerts a cytoprotective effect on the neurons.

Age of Onset↗
PubMed2003

Evaluation of amino acid patterns in recipes for kidney disease patients.

OBJECTIVE: To examine first-limiting amino acids in EAA patterns of a low-protein diet from card-style printed recipes on the market in Japan. In addition, this research explored practical knowledge about which combination of foods could cause an imbalance, if any, of amino acids, and seek to further improve diets for patients with kidney disease. METHODS: Thirty-nine card-style printed recipes for patients with diabetic nephropathy or chronic renal disease or those already on dialysis were chosen for this study. These recipes are available at major book stores in Japan. From each recipe, the first-limiting amino acid, if any, and corresponding amino acid score were investigated and identified. To determine them, the reference amino acid scoring pattern in Report of a Joint FAO/WHO Ad Hoc Expert Committee, 1973, was used as a reference. RESULTS: Among the 39 cards (recipes) examined, we found threonine to be the first-limiting amino acid in 59% of those samples, followed by valine in 8%, methionine + cystine in 3%, lysine in 3%, and leucine in 3%. In the remaining 26%, we did not find any limiting amino acids. Amino acid scores ranged from > or = 100 (26%) to 90-99 (54%), 80-89 (18%), and 70-79 (3%). QUALITY: In 26% of the samples, no deficits in regard to amino acid patterns were found in our analysis of these recipes. Valine, which is an index of malnutrition, was found to be among the first-limiting amino acids. However, because amino acid scores of less than 79 represented only 3% of all recipes chosen, EAAs in protein-controlled diets might not necessarily be deficient. CONCLUSION: The majority of the tested sample recipes were not balanced in EAA pattern, especially for threonine as the first-limiting amino acid of a meal. To prevent malnutrition in chronic renal disease, especially for those following low-protein diets, well-balanced meals on a daily basis as well as adequate energy intake are considered to be necessary.

Amino Acids↗
PubMed2003

Effect of orally administered shao-yao-gan-cao-tang (Shakuyaku-kanzo-to) on muscle cramps in maintenance hemodialysis patients: a preliminary study.

Muscle cramps are one of the most common complications of hemodialysis (HD), and often are a source of great pain in spite of various clinical measures. The traditional herbal medicine, shao-yao-gan-cao-tang (Japanese name: Shakuyaku-kanzo-to), consists of equal amounts of paeony and licorice roots, and has been used in Japan and China for muscle pain or skeletal muscle tremors. To determine whether this medicine is able to prevent frequent and unendurable muscle cramps in patients undergoing HD, Shakuyaku-kanzo-to at 6 g per day was prospectively administered for 4 weeks to five patients on HD who were suffering from frequent muscle cramps. The frequency and severity of cramping before and after the treatment treatment were carefully observed and compared. Skeletal muscle cramps completely disappeared in two of the treated patients after the start of oral administration of Shakuyaku-kanzo-to. Moreover, the frequency of cramping was significantly decreased in two of the remaining three patients after persistent administration. The severity of muscle cramps was also decreased by this treatment in the responsive patients. No serious side effects were detected during the treatment period. The inhibitory effect of Shakuyaku-kanzo-to on muscle contraction was also experimentally examined by using phrenic nerve-diaphragm preparations from male Wistar rats. Differences between the twitch responses were determined when the diaphragms and the nerves were stimulated in the presence and absence of the extract of Shakuyaku-kanzo-to. The results demonstrated that extracts of paeony and licorice roots inhibit contraction of skeletal muscles in rats. Taken together, we suggest that administration of Shakuyaku-kanzo-to is a safe, effective treatment for preventing muscle cramps in patients undergoing HD.

Administration, Oral↗
PubMed2003

Effects of KD3-671, an angiotensin II type 1 receptor antagonist, on anti-thy-1 nephritis in rats.

We examined the effects of KD3-671 (2-propyl-8-oxo-1-[(2'-(H-tetrazole-5-yl)biphenyl-4-yl)methyl]-4,5,6,7-tetrahydrocycloheptimidazole), an angiotensin II type1 receptor antagonist, on an experimental rat model of mesangioproliferative glomerulonephritis, anti-Thy-1 nephritis. Anti-Thy-1 nephritis was induced by intravenous injection of 300 microg/kg of anti-Thy-1.1 monoclonal antibody into rats. KD3-671 (3, 10, 30 mg/kg per day) or enalapril (30 mg/kg per day), an angiotensin II converting enzyme inhibitor, was given p.o. once daily from the day before the antibody injection (the 1st day) to the 15th day after. KD3-671 significantly inhibited an increase in the number of total and proliferating cell nuclear antigen-positive cells and the deposition of alpha-smooth muscle actin and fibronectin in the glomeruli of nephritic rats, but enalapril (30 mg/kg per day) suppressed only the number of total cells and the deposition of alpha-smooth muscle actin in the glomeruli. Moreover, to elucidate the effect of KD3-671 on matrix deposition in the glomeruli, we measured the production of fibronectin in isolated glomeruli obtained from anti-Thy-1 nephritic rats. The glomeruli in anti-Thy-1 nephritic rats produced more fibronectin than that in control rats. KD3-671 (10(-8), 10(-7), 10(-6) M) dose-dependently attenuated fibronectin production in isolated nephritic glomeruli. These findings suggest that KD3-671 may be an effective agent for the treatment of mesangioproliferative glomerulonephritis.

Actins↗
PubMed2003

The immunoassay of methotrexate by capillary electrophoresis with laser-induced fluorescence detection.

Immunoassay is widely employed as a highly sensitive, specific analytical method for hormones and drugs in biological samples. A technique utilizing capillary electrophoresis with laser-induced fluorescence detection was examined based on the reaction process of these immunoassays in order to develop a protocol characterized by high sensitivity and high speed. The conditions of the antigen-antibody reaction and capillary electrophoresis were variously examined using fluorescein-labeled methotrexate and the antibody of methotrexate. As a result, the immunoassay could be completed within a few minutes. Moreover, detection in the pg range could be accomplished. The sensitivity corresponded to that of radioimmunoassay. A simultaneous multi-component analysis of the immunoassay is also possible due to the high resolving power of capillary electrophoresis. In this study, the possibility of a simultaneous analysis of methotrexate and vancomycin was also investigated.

Electrophoresis, Capillary↗
PubMed2003

Pharmacokinetic and pharmacodynamic studies of SK-896, a new human motilin analogue, in healthy male volunteers.

OBJECTIVE: To investigate the pharmacokinetics and pharmacodynamics of SK-896 ([Leu(13)]motilin-Hse) after intravenous administration to healthy male volunteers. DESIGN AND SETTING: This was a non-blinded phase I study. PARTICIPANTS: Thirty male Japanese volunteers (mean age 30.6 years) participated in this study. The volunteers were divided into five groups receiving different doses of SK-896. METHODS: The pharmacokinetics and pharmacodynamics of SK-896 were evaluated after single intravenous infusions of doses of 10, 20, 40 and 80 micro g over 20 minutes to fasting volunteers, or after multiple intravenous infusions (twice a day for 3 days) of doses of 40 micro g over 20 minutes to volunteers in the morning (fasting) and afternoon (non-fasting). Plasma concentrations of immunoreactive SK-896 were determined by radioimmunoassay, and borborygmus was measured as an indicator of drug effect (acceleration of gastrointestinal motility) with an improved Holter electrocardiograph attached to the abdomen. RESULTS: When SK-896 was given by single intravenous infusion at each dose, the plasma concentration of immunoreactive SK-896 rapidly increased to a maximum at the end of the infusion. After the infusion was completed, plasma concentrations declined monoexponentially with an elimination half-time of 4.57-5.64 minutes. The area under the concentration-time curve and the maximum concentration (1.04-9.08 microg-equiv./L) increased in proportion to the dose, and there were no dose-related changes in plasma clearance (7.59-9.34 mL/min/kg), mean residence time (7.83-9.51 minutes) or steady-state volume of distribution (62.9-73.9 mL/kg), indicating that SK-896 plasma concentrations can be described by a linear pharmacokinetic model within the dose range of the present study. After beginning administration, an increase in borborygmus was observed. At doses of 40 and 80 micro g, the borborygmus did not continue even when the plasma concentration was maintained, suggesting that tachyphylaxis occurs at a higher dose. When SK-896 was given as multiple intravenous infusions, the pharmacokinetics did not change with repeated administration. The intensity of borborygmus was low with afternoon administration, reaching only one-third to one-half that with morning administration, suggesting that, like native motilin, SK-896 does not stimulate gastrointestinal motility in the non-fasting state. CONCLUSIONS: The appropriate dose and administration period (fasting or non-fasting) are important factors in stimulating and maintaining gastrointestinal motility when treating gastroparalysis with SK-896.

Adult↗
PubMed2002

Correlation of plasma neurosteroid levels to the severity of negative symptoms in male patients with schizophrenia.

The authors examined the correlations among plasma levels of ACTH, cortisol, progesterone, testosterone, and dehydroepiandrosterone sulfate (DHEA-S) and their relationship with the scales for assessment of negative symptoms (SANS) in the male schizophrenic patients with negative symptoms. The subjects were 28 male schizophrenic patients categorized as with low negative symptoms (N = 14) and with moderate negative symptoms (N = 14) and 13 healthy subjects. Plasma levels of neurosteroids were measured by radioimmunoassay. Significant correlations of SANS scores with plasma levels of ACTH, cortisol and testosterone, but not progesterone and DHEA-S, were found in the male schizophrenic patients. Furthermore, plasma levels of ACTH, cortisol, and testosterone in the male schizophrenic patients with moderate negative symptoms, but not low negative symptoms, were significantly different from normal controls. The measurements of plasma neurosteroid levels could be a useful biological marker for the severity of negative symptoms in schizophrenic patients.

Adrenocorticotropic Hormone↗
PubMed2002

Zernike-type phase-contrast hard X-ray microscope with a zone plate at the Photon Factory.

A Zernike-type phase-contrast X-ray microscope with a zone plate and a phase plate was constructed at the Photon Factory BL3C2. Parallel monochromatic X-rays of 8.97 keV were incident on a specimen and a direct beam transmitted through the specimen was focused on the back focal plane of the zone plate, where an aluminium phase plate was placed. Tantalum line patterns as fine as 0.3 microm could be imaged. Phase-contrast images of polypropylene wires and polystyrene latex beads were obtained, which showed better contrast than that of their bright field images.

Journal Article↗
PubMed2002

X-ray refraction-enhanced imaging and a method for phase retrieval for a simple object.

Refraction-enhanced imaging is now widely used for imaging low-absorption-contrast specimens in the hard X-ray region. However, the interpretation of the details of a refraction-enhanced image is not always clear. In this paper the theoretical treatment of refraction-enhanced imaging and a method for phase retrieval from refraction-contrast images are discussed in comparison with angular-deflection mapping of the transmitting beam. The problems of thick and complicated objects are also discussed.

Birefringence↗