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Biomedical subjects

K Takamiya

Publications and source records attributed to K Takamiya.

At least 73 records · Page 4Linked to original sources
PubMed1992

Molecular cloning and functional expression of the second mouse nm23/NDP kinase gene, nm23-M2.

A new murine cDNA of nm23/NDP kinase was isolated. A RT-PCR product was obtained from the normal mouse liver mRNA with primers designed for the human nm23-H2 gene. The product was used as a probe to screen a cDNA library from the murine melanoma cell line, B16, and two clones containing the entire open reading frame were obtained. It was predicted that the DNA sequence encoded 152 amino acids which was 98% identical to the nm23-H2 protein. The entire nm23-M1 and -M2 gene-coding regions were translated as fusion proteins with a glutathione S-transferase. These fusion proteins displayed NDP kinase activities.

Amino Acid Sequence↗
PubMed1992

Purification and properties of trimethylamine N-oxide reductase from aerobic photosynthetic bacterium Roseobacter denitrificans.

Trimethylamine N-oxide (TMAO) reductase was purified from an aerobic photosynthetic bacterium Roseobacter denitrificans. The enzyme was purified from cell-free extract by ammonium sulfate fractionation, DEAE ion exchange chromatography, hydrophobic chromatography, and gel filtration. The purified enzyme was composed of two identical subunits with molecular weight of 90,000, as identified by SDS-polyacrylamide gel electrophoresis, containing heme c and a molybdenum cofactor. The molecular weight of the native enzyme determined by gel filtration was 172,000. The midpoint redox potential of heme c was +200 mV at pH 7.5. Absorption maxima appeared at 418,524, and 554 nm in the reduced state and 410 nm in the oxidized state. The enzyme reduced TMAO, nicotine acid N-oxide, picoline N-oxide, hydroxylamine, and bromate, but not dimethyl sulfoxide, methionine sulfoxide, chlorate, nitrate, or thiosulfate. Cytochrome c2 served as a direct electron donor. It probably catalyzes the electron transfer from cytochrome b-c1 complex to TMAO reductase. Cytochrome c552, another soluble low-molecular-weight cytochrome of this bacterium, also donated electrons directly to TMAO reductase.

Bacteria↗
PubMed1992

Monovinyl and divinyl protochlorophyllide pools in etiolated tissues of higher plants.

The composition of chlorophyll-precursor pigments, particularly the contents of monovinyl (MV) and divinyl (DV) protochlorophyllides (Pchlides), in etiolated tissues of higher plants were determined by polyethylene-column HPLC (Y. Shioi, S. I. Beale [1987] Anal Biochem 162: 493-499), which enables the complete separation of these pigments. DV-Pchlide was ubiquitous in etiolated tissue of higher plants. From the analyses of 24 plant species belonging to 17 different families, it was shown that the concentration of DV-Pchlide was strongly dependent on the plant species and the age of the plants. The ratio of DV-Pchlide to MV-Pchlide in high DV-Pchlide plants such as cucumber and leaf mustard decreased sharply with increasing age. Levels of DV-Pchlide in Gramineae plants were considerably lower at all ages compared with those of other plants. Etiolated tissues of higher plants such as barley and corn were, therefore, good sources of MV-Pchlide. Absorption spectra of the purified MV- and DV-Pchlides in ether are presented and compared.

Journal Article↗
PubMed1991

Distribution and physiology of aerobic bacteria containing bacteriochlorophyll a on the East and west coasts of australia.

Aerobic heterotrophic bacteria containing bacteriochlorophyll were isolated from specimens from a wide variety of marine environments on the west (Shark Bay, Lake Clifton, Lake Heyward, and Perth) and east (near Townsville and Brisbane) coasts of Australia. The bacteria were found in a high proportion (10 to 30%) of the total heterotrophic bacterial strains isolated from marine algae, seagrasses, stromatolites, the epiphytes on stromatolites, seawater, and sands; in some cases they constituted up to 49% of the total. This is much higher than the previous report of 6% from Japan. A high percentage, 13%, was also found in the seawater of Hamelin Pool, at Shark Bay, where the salinity was 66%. The number of these bacteria was generally low in seawater and sands, with a few exceptions. There were no aerobic bacteriochlorophyll-containing bacteria on sponges or corals. The isolated strains were orange or pink, and most had absorption maxima around 800 and 850 to 870 nm, the latter range being the absorption of bacteriochlorophyll a in vivo. The maximum bacteriochlorophyll content was 1 nmol/mg (dry weight) of bacterial cells. Most of the bacteria did not grow phototrophically under anaerobic conditions in a broth medium containing succinate. Cells and cell extracts grown under aerobic conditions had photochemical activities such as reversible photooxidations of the reaction center and cytochrome(s). Some strains showed denitrifying activity. The optimal salinity for bacterial growth varied between strains.

Journal Article↗
PubMed1991

Muscle morphometry in amyotrophic lateral sclerosis.

Quadriceps muscle biopsies from 24 patients with amyotrophic lateral sclerosis (ALS) and 15 age-matched controls were prepared for histochemistry and analyzed morphometrically. Pathological features for denervation and reinnervation were observed in most ALS patients, although considerable variation between patients was noted. Myopathic changes were also seen in one-third of the cases. The morphometric data were not only related to the duration and mean diameter of type I fiber, but also to the duration and hypertrophy factor of type II fiber, suggesting that the progression and severity of ALS depends on the preservation of both fibers.

Adult↗
PubMed1991

Oral syndrome: an incomplete form of cheiro-oral syndrome?

Cheiro-oral syndrome is a sensory disturbance observed around the corner of the mouth and the palm of the hand on the same side. We had an opportunity to observe a patient in whom sensory disturbance was limited only around the corner of the left mouth but not the hands or other findings. Computed tomography of the brain showed a low density area in the right thalamus. Could our case be called oral syndrome: incomplete form of cheiro-oral syndrome? We have to ask whether the our case is an oral syndrome or whether our case has to be regarded as a thalamic infarction.

Aged↗
PubMed1991

MRI in patients with amyotrophic lateral sclerosis: correlation with clinical features.

Magnetic resonance imaging (MRI) of the brain was performed in 10 patients with amyotrophic lateral sclerosis (ALS) and the findings were evaluated. Four patients had asymmetrical areas of increased signal intensity in the white matter. All patients showing abnormal MRI were young, had a longer clinical course, and clinically were more disabled. These MRI abnormalities were related to the pathological changes in the central white matter of patients with ALS and possible explanations for these findings in ALS are discussed.

Adult↗
PubMed1991

Thyroid function in patients with chronic headache.

Headache is one of the neurological manifestations of hypothyroidism but it is unknown whether there is a relationship between hyperthyroidism and chronic headache. Thyroid function tests were performed in 30 patients with chronic headache. Six were found to have hyperthyroidism and none had hypothyroidism. Thyroid testing may be useful for differential diagnosis of chronic headache, and indicates that headache could be caused by hyperthyroidism.

Adult↗
PubMed1990

Concurrence of myasthenia gravis and chorée fibrillaire de Morvan.

A case of myasthenia gravis associated with a syndrome resembling "chorée fibrillaire de Morvan" is described. This association has not been previously noted in the literature. It is postulated that this syndrome, when associated with myasthenia gravis, suggests an autoimmune pathogenesis, but prednisolone and plasmapheresis did not alter the symptoms. This case illustrates the fact that a separate entity should be considered when the clinical picture is not compatible with the underlying diagnosis.

Adult↗
PubMed1990

Cognitive impairment in amyotrophic lateral sclerosis and its relation to motor disabilities.

The performance of patients with amyotrophic lateral sclerosis (ALS) on selective neuropsychological tests was examined in regard to the applicability of such examinations to diagnosis. Eighteen patients with ALS, and 15 age- and education-matched controls were given a battery of tests designed to assess motor and intellectual functions. The ALS group displayed significantly lower scores on all tests than those in the control group. Correlation analyses on the several motor and neuropsychological results in ALS group revealed that there was a significant negative correlation between upper motor symptoms and mini-mental state examination, as well as memory tests.

Aged↗
PubMed1990

A case of pure motor monoparesis due to pontine infarction.

Pure motor hemiplegia (PMH) is a common manifestation of lacunar infarction. However, pure motor monoparesis (PMM), isolated corticospinal tract deficits confined to one limb, have received little attention. We observed a patients in whom the clinical feature was compatible with PMM and discussed the possible pathomechanism of PMM.

Aged↗
PubMed1990

Cognitive dysfunction in myasthenia gravis.

The performance of patients with myasthenia gravis (MG) on selective neuropsychological tests was examined to assess the diagnostic applicability of such examinations. Twenty-seven patients with MG and twenty-seven age, sex, and education-matched controls were given a battery of tests designed to assess cognitive functions. The MG group displayed significantly lower scores on Mini-mental state test and memory tests. The results indicated that MG patients had cognitive impairment. Results are also discussed with respect to the involvement of cholinergic pathways in the central nervous system.

Adult↗
PubMed1990

Neuropsychological dysfunctions in amyotrophic lateral sclerosis: relation to motor disabilities.

A study was undertaken to elucidate the existence of cognitive and memory impairments in patients with amyotrophic lateral sclerosis (ALS) by comparing a group of ALS patients with both nonneurological medical controls (MC) and healthy controls (HC) on neuropsychological tests. We also examined the relationship between the severity of motor disabilities and intellectual impairment. Twenty-two ALS patients, 18 MCs and 17 HCs participated. The tests used were the Mini-mental state examination (MMS) and the immediate and delayed memory tests. The mean MMS score of the ALS patients was lower than the mean scores of both control groups. In the memory tests, there were significant differences between the ALS group and the two control groups. Correlation analyses of several motor symptoms and neuropsychological results revealed that there was a significant negative correlation between upper motor neuron symptoms and MMS, as well as memory tests. The evidence for multisystem degeneration in ALS has prompted speculation that more sensitive neuropsychological measurements might reveal cerebral dysfunction in ALS patients who are not presenting evident dementia.

Amyotrophic Lateral Sclerosis↗
PubMed1990

[Trophic effect of angiotensin II, vasopressin and oxytocin on the ventral spinal cord of rat embryo].

We studied trophic effects of angiotensin II, vasopressin and oxytocin on explanted ventral spinal cord cultures derived from 13 to 14-old day rat embryos. There was a significant neurite promoting effect in angiotensin II and vasopressin-treated cultures. Angiotensin II had the most potent effect at any concentrations. It became clear that minimum effective concentration was 10(-8)M in both angiotensin II and vasopressin. However, oxytocin had no neurotrophic effect at any concentrations. Our results demonstrated that angiotensin II and vasopressin have a neurotrophic effect on ventral spinal cord in cultures, and may contribute to therapeutic strategy of amyotrophic lateral sclerosis.

Angiotensin II↗
PubMed1989

Two types of cytochrome cd1 in the aerobic photosynthetic bacterium, Erythrobacter sp. OCh 114.

Components I and II of cytochrome cd1 which had different spectral features were purified from the aerobic photosynthetic bacterium, Erythrobacter sp. strain OCh 114. Component I showed an absorption maxima at 700 and 406 nm in the oxidized form, and at 621, 552.5, 548 and 416 nm in the reduced form. Component II showed an absorption maxima at 635 and 410 nm in the oxidized form and at 628, 552.5, 548 and 417 nm in the reduced form. The relative molecular mass, Mr, of both cytochromes was determined to be 135,000 with two identical subunits. Components I and II showed pI values of 7.6 and 6.8, respectively. The redox potential of hemes ranged from +234 mV to +242 mV, except for the heme d1 of component I (Em7 = +134 mV). Components I and II showed both cytochrome c oxidase and nitrite reductase activities. Cytochrome c oxidase activity was strongly inhibited by a low concentration of nitrite and cyanide. Erythrobacter cytochromes c-551 and c-552 were utilized as electron donors for the cytochrome c oxidase reaction. The high affinity of cytochrome c-552 to component II (Km = 1.27 microM) suggested a physiological significance for this cytochrome. Erythrobacter cytochromes cd1 are unique in their presence in cells grown under aerobic conditions as compared to other bacterial cytochromes cd1 which are formed only under denitrifying conditions.

Amino Acids↗