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Biomedical subjects

Y Hatakeyama

Publications and source records attributed to Y Hatakeyama.

At least 19 recordsLinked to original sources
PubMed1998

An immunohistochemical study of the localization of biglycan, decorin and large chondroitin-sulphate proteoglycan in adult rat temporomandibular joint disc.

To analyse regional variations in extracellular matrix components of adult rat temporomandibular joint discs, immunohistochemical techniques were used to examine the localization of two small dermatan-sulphate proteoglycans, biglycan and decorin, and a large chondroitin-sulphate proteoglycan. Staining for biglycan was intense in the posterior band, although it had a rather weak and even distribution throughout the disc. In contrast, staining for decorin was faint in the intermediate zone and the central part of the posterior band, moderate in the anterior and posterior attachments and most intense in the junction between the anterior band and attachment. The upper surface of the disc stained more intensely than the lower. Similarly, there was intense staining for large chondroitin-sulphate proteoglycan in the peripheral band, but both the anterior and the temporal parts of the posterior attachments were faintly stained. These results demonstrate marked regional differences in the expression of biglycan, decorin and large chondroitin-sulphate proteoglycan in the temporomandibular joint discs of adult rats. These variations probably reflect the different biomechanical environments caused by the complicated articulatory functions of the temporomandibular joint.

Animals↗
PubMed1998

Uptake of doxorubicin by cultured kidney epithelial cells LLC-PK1.

The renal handling of doxorubicin (DXR) was investigated using a kidney epithelial cell line, LLC-PK1. The uptake of DXR by LLC-PK1 cells cultured on plastic dishes was shown to be temperature and concentration dependent. The initial uptake of DXR was slightly saturable. The Km and Vmax of the saturable component were calculated to be 20.2 microM, and 0.355 nmol/mg protein/10 min, respectively. The release of DXR from LLC-PK1 cells was very slow at 37 degrees C and almost negligible at 4 degrees C, indicating that most of the DXR in the cells irreversibly binds to cellular constituents and that only a slight amount of unbound DXR participates in the efflux out of the cells. DXR uptake at 37 degrees C was significantly decreased in the presence of 2,4-dinitrophenol. However, organic cations and aminoglycoside antibiotics, such as tetraethylammonium, N1-methylnicotinamide, guanidine, gentamicin and neomycin, did not inhibit DXR uptake, suggesting that a process distinct from the organic cation transport system and absorptive endocytosis might be involved in the uptake of DXR by LLC-PK1 cells.

Alkaline Phosphatase↗
PubMed1998

New steroidal constituents from the bulbs of Lilium candidum.

Eight spirostanol saponins, including four new compounds, and two known furostanol saponins were isolated from the fresh bulbs of Lilium candidum. The structures of new compounds were determined to be (25R,26R)-26-methoxyspirost-5-ene-3 beta,17 alpha-diol 3-O-¿O-alpha-L-rhamnopyranosyl-(1-->2)-O-[beta-D-glucopyranosyl-(1-->4)] -beta-D-glucopyranoside¿, (25R,26R)-26-methoxyspirost-5-ene-3 beta,17 alpha-diol 3-O-¿O-alpha-L-rhamnopyranosyl-(1-->2)-O-[6-O-acetyl-beta-D-glucopyranos yl- (1-->4)]-beta-D-glucopyranoside¿, (25R,26R)-26-methoxyspirost-5-ene-3 beta,17 alpha-diol 3-O-¿O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranoside¿ and (25S)-spirost-5-ene-3 beta,27-diol 3-O-¿O-beta-D-glucopyranosyl-(1-->3)-O-alpha-L-rhamnopyranosyl-(1-->2)-O - [beta-D-glucopyranosyl-(1-->4)]-beta-D-glucopyranoside¿, respectively, on the basis of spectroscopic analysis, including two-dimensional NMR techniques, and the result of hydrolysis. The inhibitory activity of the isolated saponins on Na+/K+ ATPase was evaluated.

Carbohydrate Sequence↗
PubMed1998

Clinical characteristics of breast cancer patients with family history.

This study was conducted to acquire information as to the clinicopathological characteristics of breast cancer patients with family history. Of 583 patients with breast cancer, 60 (10.3%) had family history in at least one relative within the second-degree. The affected family member was most frequently a sister (43%), followed by the mother (23%) and an aunt (20%). Comparison of the data for the patients between with and without family history revealed no significant differences for any of mean age, menopausal status, histological type, histological staging, and estrogen receptor status. Although the sample size was small, neither the survival rate nor the bilaterality of disease was influenced by the family history of breast cancer.

Adult↗
PubMed1998

[Diagnosis for human parvovirus B19-polyarthritis: usefulness of empty particle B19.ELISA and B19-DNA.PCR].

OBJECTIVE: To evaluate the usefulness of new ELISA for human parvovirus B19 (B19) antibodies and PCR for the diagnosis of acute onset of B19 polyarthritis. METHODS: We evaluated the reproducibility and sensitivity on the detection of anti-B19 antibody by ELISA using recombinant VP-1 and VP-2 (empty particle), and then studied for the prevalence of IgM and IgG B19 antibody in 125 samples for anti-B19 tests. The random study on anti-B19 antibody assay as well as PCR for B19-DNA was also performed in 130 cases with acute onset of arthritis excluding those with known origins, 224 with rheumatoid arthritis and 149 with other categories. RESULTS: The results by using B19-empty particle ELISA were reproducible and showed the assay was a sensitive way for clinical use. IgM anti-B19 antibodies were positive not only in all samples from erythema infectiosum, but also often in those from hemolytic anemia, pure red cell aplasia, fetal hydrops, hepatic injury, fever of unknown origin. Among 130 with acute onset of arthritis, 21 showed positive tests for IgM anti-B19 antibody and/or B19 DNA. On the other hand, 4 among 224 patients with rheumatoid arthritis were positive for IgM anti-B19 antibody, but all of 149 in control group were negative for IgM anti-B19 antibodies and for B19 DNA. CONCLUSION AND DISCUSSION: Anti-B19 ELISA using B19-empty particle which has been introduced as a routine test system, is a useful tool for the diagnosis of acute onset of B19 arthritis. An additional examination using PCR for B19 DNA may contribute for understanding persistent B19 polyarthritis or reactivation of B19 infection.

Adolescent↗
PubMed1997

Subcutaneous loperamide prevents gastric lesions induced by necrotizing agents in rats.

The effects of subcutaneous loperamide on gastric lesions induced by necrotizing agents were investigated in the rat. Loperamide produced a dose-dependent increase of gastric fluid volume and inhibition of gastric lesions caused by 0.6 N HCl or absolute ethanol. Pretreatment with naloxone almost completely blocked both fluid pooling effect and mucosal protective effect of loperamide. Omeprazole reduced the acidity of the gastric fluid in rats treated with loperamide without significantly decreasing the fluid volume. Various volumes of acid, given orally immediately before 0.6 N HCl, volume-dependently prevented gastric lesions. We conclude that subcutaneous loperamide protects the gastric mucosa against necrotizing agents through luminal dilution of irritants, which is mediated by naloxone-sensitive opiate receptors.

Animals↗
PubMed1997

Expression of osteocalcin in cementoblasts forming acellular cementum.

To determine the phenotypic expression of cementoblasts responsible for acellular cementum, an immunohistochemical study was performed using a polyclonal antibody raised against the aminoterminal peptide of rat osteocalcin (OC). Maxillary first molars of Wistar male rats aged 2 and 3 wk were used for observations. Serial sections of decalcified paraffin embedded specimens were stained either with hematoxylin and eosin or with the anti-OC antibody. In 2-wk-old rats, apical roots were lined with the epithelial root sheath. A thin layer of acellular cementum was seen at most of the root surface, but was not seen near to root apex. In 3-wk-old rats, cellular cementum began to be formed at root apex, and acellular cementum became more thick than in 2-wk-old rats. Acellular and cellular cementum were lined with the fibroblast-like cells. Osteocalcin staining was detected in cells lining root surface in both 2- and 3-wk-old rats. Almost all cells lining cellular cementum were positive for OC. In contrast OC positive cells lining acellular cementum and root surface devoid of cementum appeared at a specific site of the root. The cells at the interradicular area of root surface were positive but the cells at the outer area (the opposite side of the interradicular area) were negative for OC. Osteoblasts and odontoblasts were positive with the antibody. The present results suggest that the OC expression of cementoblasts forming acellular cementum is similar to that of cells forming cellular cementum as well as osteoblasts and odontoblasts, and has a role for calcification of acellular cementum.

Animals↗
PubMed1997

[Recent advances in Alzheimer's disease research--amyloid precursor protein trafficking, processing, and mutations in Alzheimer's disease linked genes].

Recent advances in Alzheimer's disease (AD) research were briefly reviewed. The AD affected brain is characterized by numerous amyloid plaques, neurofibrillary tangles, and neuronal losses. The amyloid is composed of amyloid beta peptide (A beta), a 40-42 amino acid fragment of large membrane protein, amyloid precursor protein (APP). A beta is cleaved by proteolytic enzyme, beta, and gamma secretase yielding N and C terminus of the A beta. Considerable effort has been directed to identify these enzymes, and to find the intracellular compartments where A beta is generated. Endosome, lysosomal pathway, or related acidic compartment is one of the candidates for A beta generation. Biochemical and immunopathological data implicate that A beta 42 is more important than A beta 40 in the pathogenesis of AD. On the other hand, many missence mutations in APP gene and other gene, S182 (presenilin1), and STM2 (presenilin2) were identified in familial AD. Neuropathology in these FAD appear basically quite similar, and AD is regarded as cerebral A beta amyloidosis. It was established that missense mutations in the genes encoding APP, presenilin1, and presenilin2, all treated APP processing, leading to increased production of A beta 42. AD amyloid is composed of many other proteins than A beta, designated as amyloid associated proteins, It should be a key issue to determine the precise mechanism, by which A beta is generated, and the alteration of APP trafficking resulting in increased A beta 42 generation with these mutant genes.

Alzheimer Disease↗
PubMed1997

[The disturbance of reversible operation in space in the early stage of Alzheimer's disease].

Constructional apraxia is one of the neuropsychological findings frequently observed in the early stage of the Alzheimer's disease, which may result from the visuo-spatial disturbances. The visual space consists of a variety of visual information processing, viewer-centered coordinate system, objects-centered coordinate system, integration of both coordinate systems, and verifying visual representation with the knowledge in the memory. The reversible operation in space, or mental rotation appears to play an important role in visuo-spatial functions, which refers to the operation of the visual representation at one orientation in viewer-centered coordinate system to construct the representation in object-centered coordinate system so that one can look like if it were presented at another orientation. To the present, little is known about reversible operation or mental rotation in patients with Alzheimer's disease. In this present paper, we attempted to investigate the ability of reversible operations in space so as to understand the mechanisms underlying constructional apraxia, or visuo-spatial disturbances in the early stage of Alzheimer's disease. The subjects were 12 patients with Alzheimer's disease in early stage (AD group), 12 patients with multi-infarcts dementia as disease control (MID group), 12 age matched persons as healthy control (HC group). In perspective taking tasks, that requires the subjects to imagine the spatial arrangement of the objects at the different view points from the subjects' one, AD group showed more severe deficits than MID group and HC group. Moreover, in a task that the subjects were asked to assume the photo-angle of the photograph taken of the model which was in front of them, AD group was imparied compared to the control groups. These disturbances were closely associated with deficits in Block Design test of WAIS. These results clearly demonstrate that the patients with Alzheimer's disease have disturbance in reversible operation in space and that the disturbance may be responsible for visuo-spatial dysfunctions, not only the constructional apraxia, but also a variety of performance deficits in the early stage of Alzheimer's disease.

Aged↗
PubMed1996

A pyrroline glucoside ester and steroidal saponins from Lilium martagon.

A new phenylpropanoid ester of a pyrroline derivative and two new steroidal saponins were isolated from the fresh bulbs of Lilium martagon, along with several previously known compounds. The structures of the new compounds were determined by spectroscopic data, hydrolysis, and by comparison with spectral data of known compounds to be (-)-5-hydroxy-3-methyl-3-pyrrolin-2-one 5-O-(6-O-p-coumaroyl-beta-D- glucopyranoside), (25S)-spirost-5-ene-3 beta,17 alpha, 27-triol 3-O-[O-beta-D-glucopyranosyl-(1-->2)-O-beta-D-glucopyranosyl- (1-->4)-beta-D-glucopyranoside] and (25S)-5 alpha-spirostane-3 beta,17 alpha,27-triol 3-O-[O-beta-D-glucopyranosyl-(1-->2)-O-beta-D-glucopyranosyl-(1-->4)-bet a-D- glucopyranoside], respectively. Lilium martagon crosses well with L. hansonii to produce a valuable garden hybrid lily. In this study, the secondary metabolites of L. martagon were revealed to be closely related to those of L. hansonii, giving a good example of the correlation between the secondary metabolites and cross-compatibility.

Carbohydrate Sequence↗
PubMed1996

Implication of sensory neurons in the diverse mechanisms of adaptive cytoprotection in the rat stomach.

Adaptive cytoprotection is mediated by diverse mediators and mechanisms. We investigated the implication of capsaicin-sensitive afferent neurons in the adaptive cytoprotection in the rat stomach, taking special notice of nitric oxide, prostaglandins and luminal dilution. Sensory deafferentation abolished the protective effect of capsaicin against 0.6 N HCl-induced gastric injury but not the indomethacin-resistant or NG-nitro-L-arginine-resistant adaptive cytoprotection conferred by 0.1 N NaOH. Nor did it attenuate the protection by 0.35 N HCl which accompanied luminal dilution. These findings suggest that certain mild irritants do not require sensory neurons to provide nitric oxide- and prostaglandins-mediated adaptive cytoprotection and, furthermore, that capsaicin-sensitive afferent neurons are not crucial, either, so long as there is a contribution of luminal dilution in the adaptive cytoprotection.

Animals↗
PubMed1996

Detection of HIV-1 and HIV-2 antibodies among Chlamydia trachomatis infected pregnant women in Japan.

An anonymous unlinked HIV antibody test was conducted on 1632 Chlamydia trachomatis (C. trachomatis) antibody positive women from 10 institutes of 7 prefectures in Japan. All the sera were negative for both HIV-1 and HIV-2 antibodies. The result may support the suggestion that HIV prevalence is low among general population in Japan. Such a test as this study will be useful not only for developing a reliable HIV surveillance system but also for the study of sexual behavior of general population, since C. trachomatis infection is sensitive to reflect sexual contact.

Adult↗
PubMed1996

[Aging brains and the dementias].

Dementia has been defined generally as an acquired persistent impairment of intellectual function caused by organic brain diseases. The rapidly increasing incidence of dementias has been claimed on the basis of epidemic studies in Japan as well as in Western developed countries. These observations are justified by the facts that most dementias are found in people over the age of 65 years, and that the elderly population is increasing rapidly resulting in both absolute numbers and percentage of the population. In Japan, it is estimated that 1.5 million of demented persons are present. The purpose of this paper is to describe clinical manifestations and morphological alterations of aged and demented individuals, diagnostic process to differential diagnosis to provide knowledgeable approach to management, and adequate care of the demented individuals. In aged brain, there are a variety of morphological changes. Some of these are usually observed in aged brains; atrophy of the brains, loss of neurons, accumulations of lipofuscin. Others observed in pathologically aged brains, or accelerated aging brains are Alzheimer's neurofibrillary tangles, senile plaques, and granulovacuolar degeneration. Psychiatric manifestations associated with aging and dementing diseases are described. It should be realized that clinical manifestations of the demented reflect primarily the topography of the organic lesions in the brain, and functional alterations, and are influenced by psychological and socio-environmental factors.

Aging↗
PubMed1995

Luminal dilution caused by certain mild irritants and capsaicin contributes to their gastric mucosal protection.

We have recently shown that certain mild irritants caused the increase in fluid volume in the rat stomach. The present study was conducted to investigate 1) whether standing fluid in the gastric cavity can prevent gastric mucosal injury caused by 0.6 N HCl and 2) the mechanisms by which certain mild irritants increase the gastric fluid volume. One milliliter of water administered immediately before irritants greatly inhibited gastric lesion formation. Sodium chloride and capsaicin induced a profound enhancement of gastric fluid volume, as acid mild irritants did also. Sensory denervation completely abolished the volume increase caused by capsaicin but hardly influenced that caused by mild irritants. Capsaicin increased the amount of Evans blue in the gastric fluid, but mild irritants did not. On the other hand, HCl and capsaicin significantly inhibited the emptying of phenol red. From these results, we conclude that mild irritants and capsaicin can induce volume increase that by itself is enough to afford protection through luminal dilution. Capsaicin but not mild irritants requires sensory neurons to increase the gastric fluid volume. Certain mild irritants may provide a fluid pooling effect partly by inhibiting gastric emptying.

Animals↗
PubMed1995

Change in membrane permeability induced by amyloid beta-protein fragment 25-35 in brain neurons dissociated from rats.

Effects of amyloid beta-protein fragment 25-35, A beta P(25-35), on the membrane permeability of organic molecules were examined in the brain neurons dissociated from rats by using an argon laser (equipped in flow cytometer and laser microscope) and a combination of two fluorescent dyes, fluo-3-AM and ethidium bromide. A beta P(25-35) at concentrations of 1 microM or greater induced both leakage of fluo-3 from the neurons and permeation of ethidium across the membrane in a dose-dependent manner, although both dyes are highly impermeant to the intact plasma membrane. Thus, A beta P(25-35) seems to increase not only membrane permeability of inorganic ions such as Ca2+, Na+ and K+, as previously suggested, but also that of organic molecules. Therefore, the brain neuron membrane is suggested to lose its integrity in the presence of A beta P(25-35) that leads to neuronal death.

Amyloid beta-Peptides↗
PubMed1994

Flow cytometric analysis on cytotoxic action of amyloid beta protein fragment 25-35 on brain neurons dissociated from the rats.

Effects of amyloid beta protein fragment 25-35, A beta P(25-35), on membrane permeability and cell viability were examined in the brain neurons dissociated from the rats using a flow cytometer and two fluorescent dyes, fluo-3 to monitor intracellular Ca2+ concentration ([Ca2+]i) of neurons and ethidium which is impermeant to membranes of intact neurons to stain dead and dying neurons. A beta P(25-35) augmented fluo-3 fluorescence of some neurons at concentrations greater than 1 microM, indicating an increase in [Ca2+]i although other neurons (about 80% of total neurons) did not respond to A beta P(25-35) even at 10 microM. A beta P(25-35) at 1 microM or greater increased dose-dependently the number of ethidium-stained neurons, suggesting a dose-dependent increase in number of dead and dying neurons. Results suggest that A beta P(25-35) increases the membrane permeability of brain neurons, resulting in a destabilized intracellular homeostasis that leads to neuonal death.

Amyloid beta-Peptides↗
PubMed1994

Effect of N,N-diethyldithiocarbamate on ionomycin-induced increase in oxidation of cellular 2',7'-dichlorofluorescin in dissociated cerebellar neurons.

Effect of N,N-diethyldithiocarbamate (DDC), an inhibitor for cytosolic superoxide dismutase, on an ionomycin-induced increase in oxidative metabolism was examined in cerebellar neurons dissociated from the rats, using a flow cytometer and 2',7'-dichlorofluorescin diacetate and fluo-3-AM, fluorescent dyes for intracellular hydrogen peroxide and Ca2+, respectively. DDC reduced the ionomycin-induced augmentation of 2',7'-dichlorofluorescin fluorescence in a dose-dependent manner. DDC did not affect cellular content of 2',7'-dichlorofluorescin and ionomycin-induced increase in intracellular Ca2+ concentration. Results indicate that ionomycin increases the formation of superoxide anion in brain neuron.

Aniline Compounds↗