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Biomedical subjects

H Seno

Publications and source records attributed to H Seno.

At least 19 recordsLinked to original sources

Trace levels of pyrroloquinoline quinone in human and rat samples detected by gas chromatography/mass spectrometry.

A detailed procedure for the assay of free pyrroloquinoline quinone (PQQ) in human and rat samples by gas chromatography/mass spectrometry (GC/MS) has been established with stable-isotopic PQQ as internal standard. PQQ was extracted from the samples, after addition of the internal standard, with butanol under acid conditions and with Sep-Pak C18 cartridges. After derivatization of PQQ with phenyltrimethylammonium hydroxide, molecular peaks at m/z 448 and 462 were used for detection of PQQ and [U-13C]PQQ by selected ion monitoring, respectively. Trace amounts of free PQQ were detected in eight organs, plasma and urine of the human, and in three organs of the rat. The PQQ level was highest in the human spleen (5.9 +/- 3.4 ng/g tissue, followed by the pancreas and lung, and it was below detection limits for human brain and heart. Trace levels of PQQ were also found in rat small intestine, liver and testis. Our data are far below those measured by the redox cycling method of Gallop's group for human plasma, adrenal and urine.

Animals

Rapid isolation with Sep-Pak C18 cartridges and capillary gas chromatography of triazine herbicides in human body fluids.

A simple and rapid method, for the isolation of eight triazine herbicides from human serum and urine, using Sep-Pak C18 cartridges is presented. After mixing with distilled water, serum and urine samples containing the herbicides, were loaded on Sep-Pak C18 cartridges and eluted with either chloroform only or chloroform/methanol (9:1). The herbicides were detected by capillary gas chromatography with both flame ionization detection (FID) and nitrogen-phosphorus detection (NPD). Separation of eight triazine herbicides from each other and from impurities was generally satisfactory with the use of a non-polar DB-1 capillary column. Recovery of most compounds was excellent for both chloroform and chloroform/methanol (9:1) as elution solvents. Backgrounds were cleaner and evaporation time was shorter for the chloroform only than for the chloroform/methanol (9:1). The NPD gave sensitivity more than 10-20 times higher than that of FID.

Chromatography, Gas

Diurnal monoamine variation in young and old rats: a microdialysis study.

The levels of striatal extracellular DA, DOPAC, HVA and 5-HIAA significantly decreased in aged rats compared to young adults. The magnitude of age-related reduction was greater in dopaminergic than serotonergic substances. The levels of striatal extracellular monoamines in young adult rats showed significant diurnal variations. On the other hand, these substances of aged rats, except for HVA, did not exhibit significant diurnal variations. Enriched environment housing increased levels of striatal extracellular DOPAC in aged rats, but did not influence on the age-related changes of diurnal variations in the striatal extracellular monoamines.

Aging

[An autopsy case of ataxic form of Creutzfeldt-Jakob disease].

An autopsy case of ataxic form of Creutzfeldt-Jakob disease (Brownell and Oppenheimer, 1965) was reported. The patient, a 71-year-old male, noticed ataxic gait at the beginning of June in 1988, and was admitted to the Hiroshima City Hospital for the neurological examination at the end of June. He showed ataxia of the left arm and legs and diplopia. Gradually he became delirious at night. On July 16, tremor-like involuntary movement of the left hand was noticed. On July 20, he became somnolent and doubly incontinent. Myoclonus and paratonic rigidity were also observed. The EEG showed periodic synchronous discharge on July 25. The brain CT and MRI were normal. He became apallic gradually and died on October 28. The duration of illness was 5 months. At autopsy, brain weighed 1000gr. Cerebral atrophy and slight enlargement of the ventricles were observed. The cerebellum was also slightly atrophic. Histologically, the destruction of the cerebral cortical layer, slight sieve-like spongy state of the neuropil, slight neuronal loss of the thalamus and sieve-like spongy state of the striatum were observed. The cerebellar lesion was the most severe, where granular cell loss and gliosis of the cortex were observed.

Aged

Failure to verify high activities of polyamine oxidase in pregnancy serum.

The activity of polyamine oxidase in human pregnancy serum was measured by our new specific method with radioisotopic N1-acetylspermine as substrate. The activity in pregnancy serum was very low and did not increase during gestation; it was not higher than that in nonpregnancy serum. The high polyamine oxidase activities previously reported by others appear to result from contamination with diamine oxidase, the level of which is high in pregnancy serum.

Brain

Quantitative analysis of chlorpromazine by electron spin resonance (ESR) spectroscopy.

A simple and sensitive method is described for quantitative analysis of chlorpromazine in blood, serum, urine and tissue homogenate. The chlorpromazine cation radical produced by adding perchloric acid and 2,3-dichloro-5,6-dicyano-p-benzoquinone to the sample can be detected by the ESR method at room temperature. The sensitivity limit is 10 ng, that is, 20 microliters of the solution containing 0.5 microgram chlorpromazine/ml. The time needed for the measurement is within 10 min. The chlorpromazine radical thus produced is very stable; for example, 95% of the radical was observed after 24 h. The advantage of this method is discussed by comparing with the ordinary spectrophotometry which requires the purification of the sample.

Chlorpromazine

Positive and negative ion mass spectrometry and rapid isolation with Sep-Pak C18 cartridges of ten local anaesthetics.

The positive ion electron impact (PIEI), positive ion chemical ionization (PICI) and negative ion chemical ionization (NICI) mass spectra and a rapid isolation procedure using Sep-Pak C18 cartridges are presented for ten local anaesthetics. In the PIEI mode, molecular peaks were very small or missing for most compounds. Peaks at m/z 86 due to the diethylaminoethyl or propylaminoethyl group constituted base peaks in six compounds. In the PICI mode, peaks due to M + H and M + C2H5 appeared. The cation at m/z 86 was also observed for the six compounds. This ion seems useful for the screening of local anaesthetics. In the NICI mode, anions at m/z M - H constituted base peaks for all compounds, peaks at m/z M + 12 appeared in many compounds. The total ion current in the PIEI and PICI modes generally gave higher sensitivity than in the NICI mode. Local anaesthetics present in whole blood or cerebrospinal fluid (CSF) could be rapidly isolated by use of Sep-Pak C18 cartridges with chloroform/methanol as an elution solvent. Their detection was possible using wide-bore capillary gas chromatography with SPB-1 and HP-17 wide-bore capillary columns with satisfactory separation from impurities.

Anesthetics, Local

Real-time monitoring of slow-wave sleep by electroencephalogram variance.

Based on statistical variance as an index of electroencephalogram (EEG) parameters, we monitored slow-wave sleep in both humans and rats in real time and on-line with a widely used personal computer. This EEG variance method may be a useful tool to carry out biological rhythm research, including sleep studies.

Analysis of Variance

A radioisotopic assay for polyamine oxidase.

A new radioisotopic assay for polyamine oxidase with N1-acetylspermine as substrate is presented. A modified method for the chemical synthesis of radioactive N1-acetylspermine, which gave a good yield, is also described. The reaction mixture, containing N1-[14C]acetylspermine and tissue homogenate, was incubated for the enzyme reaction and applied to a minicolumn of Amberlite CG-50. The reaction product 3-[14C]-acetamidopropanal did not adsorb to the column, but passed through it; thus the eluate could be directly subjected to liquid scintillation counting. The blank levels were low and relatively constant even with crude tissue homogenates. The detection limit obtained was 0.05 nmol per tube. This method is simple, highly sensitive, and highly specific.

Animals

Failure to verify the presence of pyrroloquinoline quinone (PQQ) in bovine plasma amine oxidase by gas chromatography/mass spectrometry.

The presence of covalently bound pyrroloquinoline quinone (PQQ) in bovine plasma amine oxidase (BPAO) was examined by the use of gas chromatography/mass spectrometry. The enzyme was subjected to proteolysis with proteinase in the presence of [U-13C]PQQ as an internal standard. After isolation and derivatization of PQQ with phenyltrimethylammonium hydroxide, molecular peaks at m/z 448 and 462 were used for detection of PQQ and [U-13C]PQQ, respectively, by selected ion monitoring (SIM). In the SIM profile, although the sample extract obtained from BPAO treated with proteinase clearly showed the peak at m/z 462 for the internal standard, there were no peaks detectable at m/z 448, showing the absence of PQQ in the proteolysis digest of BPAO. Thus, our results do not support the claim that BPAO contains covalently bound PQQ in its structure.

Amine Oxidase (Copper-Containing)

Extractions of pyrroloquinoline quinone from crude biological samples.

The best conditions for extractions of free pyrroloquinoline quinone (PQQ) from crude biological samples were investigated with various organic solvents and Sep-Pak C18 cartridges. PQQ was measured with use of its native fluorescence in aqueous solution. PQQ was well extracted into n-butanol under acid conditions, and addition of NaCl did not improve the solvent extraction. PQQ, which had been extracted into n-butanol, could be re-extracted into an aqueous phase by addition of either n-heptane or pyridine, or combination of them. PQQ, which had been adsorbed to Sep-Pak C18 cartridges, could be eluted with a mixture of pyridine and water with very excellent recovery. The recovery of 1 micrograms PQQ, which had been added to 1 g human liver, brain and 1 ml plasma and had undergone the n-butanol and the Sep-Pak extractions, was 50, 75 and 105%, respectively. From the blank fluorescence, endogenous levels of free PQQ in human liver, brain and plasma were found not greater than 0.41, 0.08 and 0.13 micrograms/g or ml, respectively, if present.

Brain Chemistry

Positive- and negative-ion mass spectrometry and rapid clean-up of some carbamate pesticides.

Positive-ion electron impact (PIEI), positive-ion chemical ionization (PICI) and negative-ion chemical ionization (NICI) mass spectra of 9 carbamate pesticides are presented. In the PIEI mode, the spectra showed small molecular peaks, intense or base peaks due to M - CH3NHCO + H and peaks at m/z 58 due to CH3NHCO. In the PICI mode, peaks due to M + H, M + C2H5, M - CH3NHCO + 2H, CH3NHCO(m/z 58) and M-28 appeared. The cations at m/z 58 found in both PIEI and PICI modes seem very useful for screening of a carbamate. In the NICI mode, the spectra showed peaks due to M - CH3NHCO and characteristic anions appearing at mass numbers higher than molecular ones, which were probably due to dimerization of [M - CH3NHCO]-followed by hydrogen attachment. Carbamates, which had been added to urine, plasma, whole blood, the liver, kidney and brain, could be rapidly isolated by use of Sep-Pak C18 cartridges with chloroform as an elution solvent. They could be detected by wide-bore capillary gas chromatography with a SPB-5 column, with satisfactory separation from impurities in their underivatized forms.

Body Fluids

Relative frequencies of dementia of the Alzheimer type and vascular dementia in Japanese nursing homes.

We have studied neuropathologically 200 aged nursing home residents (101 men and 99 women) autopsied between 1976 and 1985. Seventy-three of the 200 showed dementia during life, that is, 27% and 55% of the residents in nursing homes and special nursing homes, respectively. The relative frequencies of SDAT and VD in nursing homes as a whole were the same (34%). The relative frequencies of SDAT and VD in special nursing homes, where usually high concentrations of VD have been noted, were 21% and 52%, respectively. A comparison of the results of our special nursing homes (SDAT:VD = 1:2.5) and nursing homes as a whole (SDAT:VD = 1:1) with those of Barnes and Raskind (SDAT:VD = 2:1) and Rovner et al. (SDAT:VD = 3:1) showed that the frequencies of VD in Japanese nursing homes are considerably higher than those in their American counterparts.

Aged

Rapid isolation of some antiepileptic hydantoins and their analogues with Sep-Pak C18 cartridges and capillary gas chromatography with splitless injection.

A simple and rapid method for isolation of seven antiepileptics (2 hydantoin, 2 oxazolidin, and 3 suximide derivatives) from urine and plasma is presented. Urine and plasma (1 ml) samples containing seven antiepileptics were mixed with distilled water (4 ml), and the sample solution was poured into a pretreated Sep-Pak C18 cartridge; this was washed with water and chloroform/methanol was passed through it to elute the antiepileptics. The eluate was mixed with isoamyl acetate and evaporated under a stream of N2. The drugs were detected by gas chromatography with fused silica capillary columns, splitless injection and flame ionization detection. Separation of the seven antiepileptics from each other and from impurities was satisfactory with the use of an SPB-1 capillary column. The detection limit for the seven antiepileptics with the present method was 0.1-1.0 microgram/ml urine or plasma. The recovery of the drugs from urine and plasma was more than 70% and 50%, respectively.

Anticonvulsants

[Cases of numerous diffuse plaques in the neocortex but without severe senile changes in the hippocampus].

Using modified Bielschowsky method, we studied neuropathologically 159 aged subjects autopsied during the period from 1976 to 1988, of which we found 19 cases (average age at death: 82.6 ys) with numerous diffuse plaques in the frontal and temporal neocortex and no severe senile changes in H1-H3 of Ammon's horn (dp group). Amyloid angiopathy had been excluded and one case was excluded because of considerable cerebrovascular lesions. The dp group was divided into 8 demented (average age at death: 86.0 ys) and 10 nondemented patients (average age at death: 79.7 ys). We compared the number, type, and ratio of types of senile plaques in the frontal cortex, temporal cortex, and putamen of the demented and nondemented groups, and obtained the following results: (1) Eight (14%) of the 59 nondemented and 8 (40%) of the 20 demented cases in which no severe senile changes in the neocortex and hippocampus had been detected by Bodian stain showed numerous diffuse plaques in the neocortex when the modified Bielschowsky method was used. (2) The ratio of classic and primitive plaques to diffuse plaques in the frontal cortex was the same in both groups, but the nondemented group had exclusively diffuse plaques in the temporal cortex. (3) In the putamen 2 nondemented cases (20%) and 6 demented cases (75%) had exclusively diffuse plaques. We considered that classic and primitive plaques are more closely related to dementia than are diffuse plaques in the temporal lobe in cases without severe senile changes in the hippocampus.

Aged

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

A simple and rapid method for isolation of five butyrophenones with Sep-Pak C18 cartridges from human samples, and their wide-bore capillary gas chromatography (GC), are presented. The GC was made by both flame ionization and electron capture detections. The drugs contained in alkaline samples were directly applied to the cartridges and eluted with chloroform/isopropanol (9:1). The recoveries with use of the cartridges were excellent for most drugs in both urine and plasma samples. We can recommend the Sep-Pak C18 cartridges for isolation of butyrophenones because of simplicity and rapidity, and also wide-bore capillary GC because of high sensitivity and low decomposition of drugs during passage through the column.

Antipsychotic Agents

Semicarbazide-sensitive amine oxidase activity in catfish tissues.

1. Semicarbazide-sensitive amine oxidase activity was found in five tissues of the siluroid catfish, Parasilurus asotus, using benzylamine as substrate. It was highest in the intestine, followed by the liver and skin. 2. The apparent Km value and optimal pH for benzylamine in the intestine were 49.8 microns and 8.8, respectively. 3. Substrate specificity of the enzyme was tested in the intestine and the highest activity was found with beta-phenylethylamine, followed by tryptamine and benzylamine.

Amine Oxidase (Copper-Containing)

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

A simple and rapid method for isolation of nine barbiturates with Sep-Pak C18 cartridges from human urine, plasma and whole blood, is presented; the detection of drugs was made by wide-bore capillary gas chromatography (GC) with flame ionization. The drug-containing samples, after mixing with dilute acid solution, were directly applied to the cartridges and eluted with either chloroform/methanol (9:1) or acetonitrile. Separation of the nine drugs was satisfactory with use of an intermediately polar HP-17 capillary column. Recoveries of most compounds were excellent for both chloroform/methanol and acetonitrile as elution solvents. However, backgrounds were cleaner and evaporation time was much shorter for the chloroform/methanol system. The present isolation method with use of Sep-Pak C18 cartridges and wide-bore capillary GC seem very useful in the fields of forensic chemistry, clinical toxicology and clinical pharmacology.

Barbiturates