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Biomedical subjects

H Seno

Publications and source records attributed to H Seno.

144 records · Page 8Linked to original sources

Rapid isolation with Sep-Pak C18 cartridges and wide-bore capillary gas chromatography of organophosphate pesticides.

A simple and rapid method for isolation of eleven organophosphate pesticides with Sep-Pak C18 cartridges from human urine and plasma, is presented. The detection of the pesticides was made by wide-bore capillary gas chromatography (GC) with flame ionization detection. The pesticide-containing samples, after mixing with water, were directly applied to the cartridges and eluted with chloroform/isopropanol (9:1). The recoveries with use of the cartridges were excellent for most pesticides. Separation of each pesticide peak from each other and from impurities on the gas chromatograms was also satisfactory with use of non-polar and slightly polar capillary columns. The isolation method with use of the cartridges, together with the wide-bore capillary GC, seems very useful in forensic and environmental chemistry and clinical toxicology.

Chromatography, Gas↗

Rapid isolation with Sep-Pak C18 cartridges and wide-bore capillary gas chromatography of benzophenones, the acid-hydrolysis products of benzodiazepines.

A simple extraction procedure with a Sep-Pak C18 cartridge for benzophenones and their detection after separation by wide-bore capillary gas chromatography (GC) are presented. The benzodiazepine-containing samples, after heating in acid and centrifugation, were passed through the cartridges and eluted with chloroform. Except for bromazepam, the recoveries of benzodiazepines detected as benzophenones were excellent. Separation of each benzophenone peak from impurities was achieved with an intermediately polar HP-17 capillary column. Electron capture detection gave sensitivity more than 10 times higher than that of flame ionization detection.

Acids↗

Rapid isolation with Sep-Pak C18 cartridges and wide-bore capillary gas chromatography of bromisovalum.

A simple and rapid method for isolation of bromisovalum with Sep-Pak C18 cartridges from human whole blood, plasma, and urine containing allylisopropylacetylurea as an internal standard, is presented. Detection of the drugs was made by nonpolar wide-bore capillary gas chromatography (GC) with flame ionization. The drug-containing samples, after mixing with water, were directly applied to the cartridges and eluted with chloroform-methanol (9:1). The recoveries of bromisovalum with use of the cartridges were excellent. Bromisovalum and internal standard allylisopropylacetylurea could be satisfactorily separated from each other and from impurities with the wide-bore capillary column. The detection limit for bromisovalum was 2-5 ng in an injected volume.

Bromisovalum↗

Capillary gas chromatography with four different detectors for dinitroaniline herbicides in human body fluids.

A simple and rapid method for extraction of seven dinitroaniline herbicides from human whole blood and urine using Sep-Pak C18 cartridges is presented. After mixing with distilled water, whole blood and urine samples containing the herbicides were loaded on Sep-Pak C18 cartridges and eluted with chloroform-methanol (9:1). The recovery of the seven compounds that were added to whole blood and urine was more than 91%. The herbicides were detected by capillary gas chromatography (GC) with electron-capture detection (ECD), surface-ionization detection (SID), nitrogen-phosphorus detection (NPD), and flame-ionization detection (FID). GC-ECD generally gave the highest sensitivity for all herbicides, whereas GC-FID gave the lowest sensitivity. Isopropalin could be detected by GC-SID with a sensitivity comparable with that of GC-ECD; high sensitivity could also be obtained for isopropalin, pendimethalin, and nitralin using GC-NPD. The calibration curve for the seven herbicides measured by GC-ECD showed linearity in the range of 0.047-3.0 pmol on-column. The detection limits of the herbicides were 24-45 fmol on-column for whole blood and 19-40 fmol on-column for urine.

Aniline Compounds↗

A simple and sensitive quantitation of N,N-dimethyltryptamine by gas chromatography with surface ionization detection.

A simple and sensitive method for determination of N,N-dimethyltryptamine (DMT) by gas chromatography (GC) with surface ionization detection (SID) is presented. Whole blood or urine, containing DMT and gramine (internal standard), was subjected to solid-phase extraction with a Sep-Pak C18 cartridge before analysis by GC-SID. The calibration curve was linear in the DMT range of 1.25-20 ng/mL blood or urine. The detection limit of DMT was about 0.5 ng/mL (10 pg on-column). The recovery of both DMT and gramine spiked in biological fluids was above 86%.

Calibration↗

Solid-phase microextraction and GC-ECD of benzophenones for detection of benzodiazepines in urine.

Benzodiazepines are common drugs that cause intoxication. Benzodiazepines and their metabolites can be converted by hydrolysis in acid to the corresponding benzophenones, which are easier to be separated from matrices because of their hydrophobic properties. In this study, a new separation technique called solid-phase microextraction (SPME), which can integrate extraction, concentration, sampling and sample introduction into one single procedure, has been employed to extract the products of benzodiazepines from urine after acid hydrolysis. The extracts were determined by gas chromatography with electron-capture detection (GC-ECD). The hydrolysis conditions were optimized by a statistic orthogonal design. Factors influencing direct-immersion (DI)-SPME process were also checked and chosen experimentally. The method was evaluated with spiked human urine samples. The recoveries of nine benzodiazepines ranged from 1 to 25%, with the highest for oxazolam and the lowest for bromazepam. The calibration curves were linear from 10 to 500 ng/mL for oxazolam, haloxazolam, flunitrazepam, nimetazepam, and clonazepam and from 20 to 1000 ng/mL for the others except bromazepam. The detection limits were 2-20 ng/mL for most drugs tested. The intraday and interday coefficients of variation of the developed method were within 10 and 17%, respectively. In addition, the utility of the method was confirmed by determining two ingested benzodiazepines (flunitrazepam and oxazolam) in a volunteer's urine; urine flunitrazepam was still detectable 32 h after a therapeutic dose (1.2 mg) of the drug. Finally, the DI-SPME was compared with the conventional liquid-liquid extraction with regard to detection limits and extraction efficiency of the analytes. By DI-SPME, more amounts of analytes could be introduced into GC column than by conventional liquid-liquid extraction, and thus lower detection limits of the analytes were reached, although benzophenone recoveries by DI-SPME were rather low.

Adult↗

Reversible pitch perception deficit caused by carbamazepine.

Carbamazepine (CBZ) is an antiepileptic drug frequently used to treat a variety of neurologic diseases or symptoms. In addition, the drug is used as a mood stabilizer in patients with affective or schizophrenic disorders. Among its adverse effects, auditory disturbance is described rarely. In this report, we describe a 25-year-old woman who noted falsely higher pitch perception after starting CBZ treatment for schizoaffective disorder. We also review the literature reporting CBZ-associated abnormal pitch perception.

Adult↗

3D-CT stereoscopic imaging in maxillofacial surgery.

We obtained stereoscopic 3D-CT images in maxillofacial bone fracture patients. These images are made at two different angles. One is equivalent to the view obtained by a subciliary incision during surgery. Another is equivalent to the view obtained by oral incision during surgery. A stereoscopic image is created with a pair of images that differ from each other by a 6 degree shift of the z axis.

Adult↗

Comparison between multiple lacunar infarcted patients with and without dementia in nursing homes in shimane prefecture, Japan.

We evaluated the activity of daily living (ADL) scores, the frequency of hypertension (HT) and diabetes mellitus (DM), and the frequency and distribution of white matter lesions in a vascular dementia group with multiple lacunar infarctions (VD group; 20 cases) and a nondemented group with multiple lacunar infarctions (non-D group; 32 cases), relative to a normal control group (29 cases). There were no significant differences in HT and DM among the three groups. ADL scores were significantly lower in the VD than in the non-D group, each of which was lower than in the control group. Frequency of white matter lesions (Binswanger's disease-like lesions in the frontal and parietal lobes) was significantly higher in the VD than in the non-D group, which was higher than in the control group. We believe that for dementia with multiple lacunar infarctions, diffusely affected cerebrum including white matter lesions, which results in low ADL scores for symptoms, may be a prerequisite.

Activities of Daily Living↗

A neuropathological study of dementia in nursing homes over a 17-year period, in Shimane Prefecture, Japan.

BACKGROUND: In Japan, vascular dementia (VD) has been responsible for the majority of all dementia cases in both epidemiological and neuropathological studies. Recently, however, several epidemiological investigations have shown that the rate of VD has decreased and senile dementia of the Alzheimer type (SDAT) is now the major cause of dementia, though few neuropathological investigations show that the majority of dementia is SDAT. OBJECTIVE: The purpose of the study was to clarify the rates of dementia types in Japanese nursing home residents and to compare the ratio of SDAT to VD in the first and second halves of the study. METHODS: One hundred and twenty-two demented nursing home residents (48 men and 74 women) were evaluated neuropathologically over a period of 17 years in Shimane prefecture, Japan. All subjects died between 1976 and 1992. The average age at death was 81.4 +/- 9.4 years for men, 85.0 +/- 7.2 for women and 83.6 +/- 8.3 for total samples. RESULTS: In classifying dementia type, SDAT accounted for 34% (41 cases); VD 35% (42); mixed dementia 11% (14); and 'other' dementia 20% (25) of all samples. Comparison of the first 9-year period with the second 8-year period revealed the ratio of SDAT to VD tended to increase (from 0.83 to 1.15). This increasing tendency was found both in men (from 0.53 to 0.7) and in women (from 1.13 to 1.44). These tendencies, however, were not statistically significant. CONCLUSION: There was no change statistically in the ratio of SDAT to VD between the first half of the study and the second half. However, there was an increasing tendency of the ratio in our study.

Aged↗

Frequency and classification of cerebral infarctions in nursing homes over a 17-year period in Shimane prefecture, Japan.

BACKGROUND: Several recent epidemiological investigations have shown that the rate of vascular dementia (VD) has decreased and the rate of senile dementia of the Alzheimer type has increased in Japan. In our previous neuropathological examination, such a trend but no significant differences were shown in nursing home residents in Shimane Prefecture, Japan. OBJECTIVE: The aim of this study was to clarify whether or not the frequency of cerebral infarctions (CI) and the ratio of CI [large infarction type (LI) and small multiple infarction (MI)] types changed between the first half of this study and the second half, corresponding to the decreasing trend of the rate of VD. METHODS: Three hundred and ten aged nursing home residents (146 men and 164 women) were evaluated neuropathologically in Shimane prefecture, Japan. All subjects died between 1976 and 1992. The average age +/- standard deviation at death was 79.1+/-8.7 years for men, 83.4+/-7.8 for women, and 81.4+/-8.5 overall. They were placed into the first or second study group and compared. RESULTS: (1) The incidence of hypertension (HT) decreased significantly from the first half of the study to the second half in both men and women. (2) The frequencies of CI and CI with HT were not significantly different between the first and second half (both men and women). (3) There was a decreasing trend in the ratio of LI to MI from the first to the second period in men. CONCLUSION: There may be no effect of the incidence of HT on CI frequency and some effects on CI types. The incidence of CI in total lifespan (both men and women) has not changed in our study. The recent decreasing trend in LI in men may have contributed to the decreasing tendency in the prevalence of vascular dementia.

Aged↗

Sensitive determination of n-hexane and cyclohexane in human body fluids by capillary gas chromatography with cryogenic oven trapping.

A sensitive method was developed for determination of n-hexane and cyclohexane in human body fluids by headspace capillary gas chromatography (GC) with cryogenic oven trapping. Whole blood and urine samples containing n-hexane and cyclohexane were heated in a 7.5 mL vial at 70 degrees C for 15 min, and 5 mL of the headspace vapor was drawn into a glass syringe. All vapor was introduced through an injection port of a GC instrument in the splitless mode into an Rtx-Volatiles middle-bore capillary column at an oven temperature of -40 degrees C for trapping volatile compounds. The oven temperature was programmed to 180 degrees C for GC with flame ionization detection. These conditions gave sharp peaks for both n-hexane and cyclohexane, a good separation of each peak, and low background impurities for whole blood and urine. The extraction efficiencies of n-hexane and cyclohexane were 13.2-30.3% for whole blood and 12.7-20.7% for urine. The coefficients of within-day variation in terms of extraction efficiency of both compounds were 5.0-9.5% for whole blood and 3.8-10.8% for urine; those of day-to-day variation for the compounds were not greater than 16.6%. The regression equations for n-hexane and cyclohexane showed good linearity in the range of 5-500 ng/0.5 mL for whole blood and urine. The detection limits (signal-to-noise ratio = 3) for both compounds were 1.2 and 0.5 ng/0.5 mL for whole blood and urine, respectively. The data on n-hexane or cyclohexane in rat blood after inhalation of each compound are also presented.

Animals↗

Familial Creutzfeldt-Jakob disease: three autopsy cases of the panencephalopathic type.

Three autopsy cases of panencephalopathic type of familial Creutzfeldt-Jakob disease (CJD) were investigated. Cases 1 (51-year-old male) and 3 (54-year-old female) were siblings and Case 2 (68-year-old female) was their aunt. In cases 1 and 3, the age of onset (Case 1:51, Case 3:53), duration of illness (Case 1:9 months, Case 3:8 months) and neuropsychiatric symptoms (pyramidal and extrapyramidal tracts involvements, blindness and dementia in chronological order) were similar, but in Case 2, the onset was later (66 years old), duration was longer (32 months) and the initial symptom was dementia. Myoclonus and apallic state in the terminal stage were common to all 3 cases. Neuropathologically, all 3 cases had characteristics that indicated panencephalopathic type of CJD. Cases 1 and 3 had similar neuropathological findings with characteristic circumscribed necrotic foci in the subcortical white matter. In Case 2 in contrast, diffuse demyelination and fibrillary gliosis in the cerebral white matter were observed without circumscribed necrotic foci. In the cerebellum of Case 3, granular cell loss was very slight. The other lesions in the cerebral cortex and striatum of the 3 cases were common. In conclusion, the clinical symptoms and neuropathological findings of our familial CJD cases were different from one another.

Aged↗

Neuro-Behçet disease with demyelination and gliosis of the frontal white matter.

A rare case of neuro-Behçet disease with diffuse demyelination and gliosis of the frontal white matter is reported clinico-pathologically. The disease began with genital ulcer and recurrent oral aphthosis when the patient was 42 years of age. There was erythema, moderate fever, CSF (cerebrospinal fluid)-pleocytosis and elevated CSF-globulin. He was diagnosed as having neuro-Behçet disease and treated with prednisolone. He gradually became euphoric, disinhibited, indifferent and demented. His cranial CT showed diffuse low density areas in the bilateral frontal white matter. He became bedridden, akinetic mute and died from respiratory dysfunction 3 1/2 years after onset. The following neuropathological findings were observed: 1) Moderate demyelination and gliosis was present mainly in the frontal and parietal white matter. 2) There were many micro-spongious necrotic foci in the gray and white matters of the cerebrum, basal ganglia, thalamus, midbrain and pons, some of which were accompanied by gliosis. 3) From 1/2 to 1/3 of all micro-necrotic foci in the frontal white matter were old and accompanied by gliosis. The white matter containing numerous micro-necrotic foci had myelin pallor and gliosis. 4) There was neither micro-necrosis nor gliosis in the occipital lobe. The pathogenetic correlation of white matter lesions with primary and secondary circulatory disturbances is discussed.

Atrophy↗