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Yuko Saito

Publications and source records attributed to Yuko Saito.

45 records · Page 3Linked to original sources
PubMed2003

The effect of light on the gravimorphogenesis of cucumber seedlings.

Light affects the responses of plants to gravity. For example, light is inhibitory to the gravimorphogenesis of cucumber seedlings, peg formation. We have suggested that auxin regulates peg formation by stimulating the expression of auxin-inducible genes including CsACS1 that encodes key enzyme in ethylene synthesis. We also have hypothesized that ethylene promotes the development of peg in cucumber seedlings. To understand how light inhibits peg formation, we examined the effects of light on the auxin-induced peg formation, the expression of auxin-inducible genes and ethylene production in cucumber seedlings. Number of seedlings that produced a peg in response to applied IAA was significantly decreased by exposure to light compared with that in the dark. In addition, exposure of seedlings to light decreased mRNA accumulation of CsACS1 and ethylene production. However ethylene application did not compensate the inhibition of peg formation by light. These results suggest that light blocks auxin-mediated step(s) including CsACS1 expression for the initiation of peg formation.

Cucumis sativus↗
PubMed2003

Effects of gravity on early embryogenesis [correction of embryogeneis] in Caenorhabditis elegans.

The embryonic development of the nematode Caenorhabditis elegans was examined under different gravitational conditions. The embryos after fertilization normally hatched under hypergravity (200 G) or 3D-clinorotation, whereas the number of eggs laid from an adult hermaphrodite decreased and their hatching rate was reduced under the hypergravity condition. The first cleavage plane in the 1-cell embryo was slid to some extent by re-orientation of liquid culture vessel, but the pattern and timing of cleavages were not affected.

Animals↗
PubMed2002

Severe involvement of the ambient gyrus in a case of dementia with argyrophilic grain disease.

We report here the severe involvement of the ambient gyrus in a case of argyrophilic grain (AG) dementia (AGD). The patient was a 78-year-old man who was first presented with prosopagnosia (agnosia of the face) at age 68, which was followed by progressive mental decline and the patient's death in a state of tetraplegia. The postmortem study showed severe atrophy of the medial temporal lobe with anterior gradient, most prominent in the ambient gyrus. Histologically, numerous AGs, pretangles and coiled bodies were detected by Gallyas-Braak (G-B) silver staining and also by immunostaining with various anti-tau antibodies in the affected area. Tau-immunoreactive ballooned neurons were also present. Neuronal loss and gliosis with laminar sponginess were evident in the ambient gyrus. Diffuse plaques were seen in the neocortex and frequently associated with clusters of AGs, which were morphologically distinct from neuritic plaques. Neurofibrillary tangles were localized in the entorhinal area. Vascular lesions were very scanty. Thus, this case fulfilled the morphological criteria of AGD. It is still unclear whether AG itself causes neuronal degeneration leading to dementia. The present case may reflect the importance of the ambient gyrus in the center of neuronal degeneration in AGD.

Aged↗
PubMed2002

Niemann-Pick type C disease: accelerated neurofibrillary tangle formation and amyloid beta deposition associated with apolipoprotein E epsilon 4 homozygosity.

Niemann-Pick type C disease is a neurovisceral storage disorder. Neurofibrillary tangles similar to those in Alzheimer's disease have been reported in most juvenile/adult patients without amyloid beta protein (Abeta) deposits. Recently, we found deposits of Abeta in the form of diffuse plaques in three (31- and 32-year-old sisters and a 37-year-old man) of nine Niemann-Pick type C disease patients, who presented with most severe tauopathy and with numerous neurofibrillary tangles. Abeta deposits were not detected in any of the control brains of patients younger than age 42 years. These three patients with Abeta deposit all were homozygotes of apolipoprotein E epsilon 4. Our study suggested that NPC1 gene mutations combined with homozygosity of apolipoprotein E epsilon 4 alleles could manifest neuropathology similar to that of Alzheimer's disease. Investigation of these patients may provide an important clue for understanding the pathogenesis of Alzheimer's disease.

Adult↗
PubMed2002

Severe involvement of ambient gyrus in dementia with grains.

Argyrophilic grains are detected as punctate or filiform structures in the neuropil of the medial temporal lobe, and dementia with grains (DG) is defined as a form of dementia with argyrophilic grains as the only explainable cause. We found argyrophilic grains in 43.2% of our 190 serial autopsy brains (mean age, 79.7 yr) from a community-based geriatric hospital, but only 20% of these argyrophilic grain-positive brains fulfilled the criteria for DG. To determine if there are structural differences between cognitively normal cases with argyrophilic grains (CNG) and DG, we studied 14 brains with CNG and 15 brains with DG. All cases of DG had severe atrophy of the ambient gyrus (the junction between temporal lobe and amygdala) with spongiosis, neuronal loss, and gliosis, as well as many grains, pretangles, coiled bodies, and tau-immunoreactive astrocytes. Comparable changes were not present in the ambient gyrus of CNG brains. The temporal neocortex and hippocampus were relatively spared in DG, in contrast to Alzheimer disease. Our study suggests that selective severe involvement of the ambient gyrus may explain the clinical manifestations of a limbic-type dementia in DG.

Aged↗
PubMed2002

[2001 survey of pollen in Wakayama City with a real-time pollen counter].

Self-care is gradually being recognized as important in the treatment of pollinosis, based up to now on data on airborne pollen. To determine the real-time numbers of airborne pollen would be more useful in self-care, however, so we studied the usefulness of the real-time pollen counter. Between Feb. 2, 2001, and Apr. 26, 2001, 4 types of airborne pollen i.e., Japanese cedar, Japanese cypress, black alder, and beech observed in Wakayama City were counted with a Durham pollen counter and a real-time pollen counter (Yamato Manufacturing Co. Ltd.). Correlation between the 2 pollen counters was r = 0.69 for Japanese cedar in March and r = 0.89 for Japanese cypress in April. A high correlation was observed between outcomes of the 2 pollen counters. The amount of pollen from black alder and beech was less than that from Japanese cedar and cypress. Unexpected peaks were observed not related to the pollen number is apparently due to snow. We have taken measure against snow, so we concluded that the real-time pollen counter was useful in counting the amount of airborne pollen over time.

Air Pollutants↗