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Biomedical subjects

K Maeda

Publications and source records attributed to K Maeda.

At least 19 recordsLinked to original sources
PubMed1979

Pattern of aliphatic dicarboxylic acids in uremic serum including a new organic acid, 2,4-dimethyladipic acid.

(1) 2,4-Dimethyladipic acid was first identified in normal human urine using gas chromatography-mass spectrometry. Urinary excretion of 2,4-dimethyladipic acid in 7 healthy adults ranged from 4.9 mumol to 14 mumol per 24 h. (2) Succinic acid, adipic acid, 3-methyladipic acid, 2,4-dimethyladipic acid, pimelic acid and azelaic acid were identified in the ultrafiltrate of the blood obtained from a chronic uremic patient using a hemodialyzer. (3) Levels of succinic acid, adipic acid, 3-methyladipic acid, 2,4-dimethyladipic acid, pimelic acid and azelaic acid in uremic serum were determined using a mass fragmentographic technique. Concentration of succinic acid in uremic serum was comparable to that in normal serum, whereas concentrations of adipic acid, 3-methyladipic acid, 2,4-dimethyladipic acid, pimelic acid and azelaic acid were highly elevated in uremic serum.

Adipates↗
PubMed1979

A gas chromatographic-mass spectrometric assay for nine hydroxyphenolic acids in uremic serum.

A mass fragmentographic method for the determination of m-hydroxybenzoic acid, p-hydroxybenzoic acid, o-hydroxyphenylacetic acid, m-hydroxyphenylacetic acid, p-hydroxyphenylacetic acid, vanillic acid, p-hydroxymandelic acid, homovanillic acid and vanilmandelic acid in uremic serum is described. The hydroxyphenolic acids were extracted from one ml of serum ultrafiltrate. After trimethylsilylation, the extract was analyzed by a gas chromatograph-mass spectrometer. Concentrations of nine hydroxyphenolic acids are higher in uremic serum. In particular, p-hydroxybenzoic acid and p-hydroxyphenylacetic acid are markedly increased in uremic serum. The influence of hemodialysis on the hydroxyphenolic acids was studied by quantitating the acids before and after hemodialysis.

Female↗
PubMed1979

Ion-exchange chromatographic separation and fluorometric detection of guanidino compounds in physiologic fluids.

A high-performance liquid chromatographic procedure has been developed for the separation and fluorometric detection of guanidino compounds in physiologic fluids. All guanidino compounds were separated on a 17 X 0.46 cm cation-exchange column using a stepwise pH gradient. The chromatographic system was designed to enable the use of the specific reagent 9,10-phenanthrenequinone as a means of monitoring the guanidino compounds of physiologic fluids. This new analytical method is so sensitive that it enables the analysis at the picomole level. Our automatic guanidino-compound analyzer was successfully applied to the quantitative determination of all guanidino compounds in physiologic fluids from normal controls and uremic patients.

Autoanalysis↗
PubMed1979

Quantitative analysis of methylguanidine and guanidine in physiologic fluids by high-performance liquid chromatography-fluorescence detection method.

A rapid and sensitive high-performance liquid chromatographic method has been developed for the quantitative analysis of methylguanidine and guanidine in physiological fluids. These quanidino compounds are separated on a 6 x 0.23 cm cation-exchange column with 0.5 M sodium hydroxide solution. The guanidino compounds are detected with a fluorometer, which monitors the fluorescent guanidine derivatives produced by the reaction of the eluted constituents with 9,10-phenanthrenequinone. Sensitivity to sub-nanomole levels of methylguanidine and guanidine is demonstrated. The method was successfully applied to physiological fluids such as serum and cerebrospinal fluid from uremic patients.

Chromatography, High Pressure Liquid↗
PubMed1979

Surveillance of the daily PCB intake from diet of Japanese women from 1972 through 1976.

A survey of the daily PCB intake from the total diet of Japanese women was made for the years 1972 through 1976. All but one sample of 177 samples analyzed were contaminated with PCBs. Only one sample exceeded the acceptable daily intake (ADI) of PCBs of 5 micrograms/kg body weight in Japan. The average daily intake of PCBs per person was approximately 10 micrograms, which was very low compared to the ADI value. The main source of PCBs in the diet in Japan was inshore fishes, in contrast to fresh water fishes as in the U.S.A. The data obtained from this surveillance showed no statistically significant change of daily PCB intake from the diet during this 5-year period. However, there has been a marked decrease in the estimated intake of PCBs since 1972. Gas chromatograph analysis of the residual PCB patterns in the diet showed that the patterns in the marine products were somewhat different from those in dairy, meat, and poultry products. The former was similar to the pattern of the PCB standards mixture and the latter was similar to the PCB pattern found in human milk and tissue samples from the Japanese population.

Adult↗
PubMed1979

[Posture and muscular fatigue during work with a book-keeping machine].

A survey on localized fatigue was carried out in 119 accounting machine operators. In 51 cases the dimensions of the working places and different characteristics of the body postures were measured. The incidence of localized fatigue symptoms was found to be related to the degree of ulnar deviation of the hand, to the angle of the elbow as well as to the angle of the head inclination.

Adolescent↗
PubMed1979

Thermosensory transduction in Escherichia coli: inhibition of the thermoresponse by L-serine.

Information processing of the thermoresponse in Escherichia coli was compared with that of the chemoresponse. Competition experiments between various chemical stimuli and the thermal stimulus showed that only L-serine was a potent inhibitor of the thermosensory transduction. The concentration of L-serine necessary for complete inhibition of the thermoresponse was about 0.1 mM. L-Serine at this concentration did not inhibit chemoresponses to many amino acids. Pleiotropic aspartate-taxis mutants (tar) showed normal thermoresponse but pleiotropic serine-taxis mutants (tsr) showed decreased or almost no thermoresponse. These results suggest that the thermosensory transducing system in E. coli has an intimate interaction with the chemosensory transducing pathway specific for L-serine. A simple model for the thermosensory transduction is discussed.

Aminoisobutyric Acids↗
PubMed1979

Problems with activated charcoal and alumina as sorbents for medical use.

Although activated charcoal and alumina have been used extensively as sorbents in uremic patients, the following problems remain to be solved: 1) elution of SO4--from activated charcoal which does not adsorb it; 2) production of methylguanidine from creatinine on the surface of activated charcoal; 3) production of lipoperoxide from fatty acids by chemical reaction of activated charcoal; 4) adsorption of Ca++ and Mg++ when alumina adsorbs inorganic phosphate. These problems are studied in vitro and clinically.

Adsorption↗
PubMed1979

Cancer in the aged: an autopsy study of 940 cancer patients.

In an autopsy study of 940 elderly cancer patients, 1,030 cancers were identified. The prevalence rate for overall cancer declined after age 85 in men and after age 75 in women. The chief sites of major cancers were the stomach, lung, esophagus, liver, and pancreas, in that order. Incidental cancers (chiefly of the prostate, thyroid, and colon) were found more often in patients over 80 years old. For multiple primary cancers, the prevalence rate was relatively constant until the age of 70, when it rose to a peak in the 80--84 age group before declining to the original level.

Age Factors↗
PubMed1979

Diagnosis and classification of the mitral valve prolapse by the ultrasoundcardiotomography and the evaluation of the M-mode technic.

Eighty cases with mitral valve prolapse excluding the secondary prolapse of the mitral valve caused by known underlying diseases were studied by real-time ultrasoundcardiotomography and M-mode technic. It was thought that observation of the left ventricle with long axis sector scan was useful and sensitive technic to diagnose the mitral valve prolapse. By comparative study of M-mode technic and ultrasoundcardiotomography, echo sources and the mechanism of so called prolapse patterns such as pansystolic bowing, mid-systolic buckling and multilayered echoes were explained. Pansystolic bowing and mid-systolic buckling were considered as the reliable signs for diagnosis of anterior leaflet prolapse, but were not contributory to diagnose posterior leaflet prolapse and ultrasoundcardiotomographic technic was needed to detect the posterior leaflet prolapse. According to the mode of prolapsing findings by ultrasoundcardiotomograms classification of severity of mitral valve prolapse was undertaken and its grade was expressed as AmPn in which A and P designated prolapse of the anterior and posterior leaflet respectively and m and n indicated the grade of severity in number from zero to five.

Adolescent↗
PubMed1979

Studies on the progress of occupational cervicobrachial disorder by analysing the subjective symptoms of work-women in assembly lines of a cigarette factory.

The Committee on Cervicobrachial Syndrome in Japan Association of Industrial Health (JAIH) made a report on the questionnaires for checking for the complaints of patients suffering from Occupational Cervicobrachial Disorder (OCD). In order to reveal how the complaints develop in the progress of OCD, we analysed the complaints of 117 workwomen in assembly lines of a cigarette factory by using the questionnaires. And the followings were made clear: 1) At the mild stage of OCD, stiffness or dullness at the neck and shoulders, and eyestrain become remarkable. 2) At the moderate stage, pain at the neck, shoulders, arms and hands, dullness at extremities, general fatigue, pain or heavy feeling in the head, increased irritability etc. become remarkable in addition to the mild stage complaints. 3) At the severe stage, pain and dullness at the back, numbness at arms and hands, hand coldness, sleep disturbance etc. become remarkable in addition to the moderate stage complaints. 4) Various sufferings in daily life such as "I want to lie down at rest time," "I lack patience to go on reading long," "It is hard for me to go on writing long," and "Fixed sitting soon tires me" become more and more frequent as the stage advances. We consider it is important in the diagnosis of OCD to pay attention to the general symptoms such as general fatigue, pain or heavy feeling in the head, increased irritability and sleep disturbance, together with complaints at the neck, shoulders, arms and hands.

Adult↗