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Biomedical subjects

H Mori

Publications and source records attributed to H Mori.

At least 199 records · Page 11Linked to original sources
PubMed2000

Electro-acupuncture stimulation to a hindpaw and a hind leg produces different reflex responses in sympathoadrenal medullary function in anesthetized rats.

The effects of electro-acupuncture stimulation (EAS) of two different areas of a hindlimb with different stimulus intensities on sympathoadrenal medullary functions were examined in anesthetized artificially ventilated rats. Two needles of 160 microm diameter and about 5 mm apart were inserted about 5 mm deep into a hindpaw (Chungyang, S42) or a hind leg (Tsusanli, S36) and current of various intensities passed to excite various afferent nerve fiber groups at a repetition rate of 20 Hz and pulse duration of 0.5 ms for 30-60 s. Fiber groups of afferent nerves stimulated in a hindlimb were monitored by recording evoked action potentials from the afferents innervating the areas stimulated. The sympathoadrenal medullary functions were monitored by recording adrenal sympathetic efferent nerve activity and secretion rates of catecholamines from the adrenal medulla. EAS of a hindpaw at a stimulus strength sufficient to excite the group III and IV somatic afferent fibers produced reflex increases in both adrenal sympathetic efferent nerve activity and the secretion rate of catecholamines. EAS of a hind leg at a stimulus strength sufficient to excite the group III and IV afferent fibers produced reflex responses of either increases or decreases in sympathoadrenal medullary functions. All responses of adrenal sympathetic efferent nerve activity were lost after cutting the afferent nerves ipsilateral to the stimulated areas, indicating that the responses are the reflexes whose afferents nerve pathway is composed of hindlimb somatic nerves. It is concluded that electro-acupuncture stimulation of a hindpaw causes an excitatory reflex, while that of a hind leg causes either excitatory or inhibitory reflex of sympathoadrenal medullary functions, even if both group III and IV somatic afferent fibers are stimulated.

Action Potentials↗
PubMed2000

Effects of 6-formylpterin, a xanthine oxidase inhibitor and a superoxide scavenger, on production of nitric oxide in RAW 264.7 macrophages.

As well as superoxide generated from neutrophils, nitric oxide (NO) produced by inducible nitric oxide synthase (iNOS) in macrophages plays an important role in inflammation. We previously showed that 6-formylpterin, a xanthine oxidase inhibitor, has a superoxide scavenging activity. In the present study, to elucidate other pharmacological activities of 6-formylpterin, we investigated the effects of 6-formylpterin on production of nitric oxide (NO) in the murine macrophage cell line RAW 264.7 stimulated by lipopolysaccharide (LPS) and interferon-gamma (INF-gamma). 6-Formylpterin suppressed the expression of iNOS, and it also inhibited the catalytic activity of iNOS, which collectively resulted in the inhibition of NO production in the stimulated macrophages. However, 6-formylpterin did not scavenge the released NO from an NO donor, S-nitroso-N-acetylpenicillamine (SNAP). These results indicate that 6-formylpterin inhibits pathological NO generation from macrophages during inflammation, but that it does not disturb the physiological action of NO released from other sources.

Animals↗
PubMed2000

DNA fragmentation in the CA2 sector of gerbil hippocampus following transient forebrain ischemia.

It has been reported that following transient forebrain ischemia in the gerbil, "delayed neuronal death" and "reactive change" occur in hippocampal CA1 and CA2 sectors, respectively. In the present study, using the gerbil transient forebrain ischemia model, we examined brain sections after various recirculation periods and demonstrated, employing the in situ nick-end labeling (TUNEL) method, a nuclear DNA fragmentation in the damaged CA2 neurons.

Animals↗
PubMed2000

Increase of fragmented DNA transport in apical dendrites of gerbil CA1 pyramidal neurons following transient forebrain ischemia by mild hypothermia.

Mild hypothermia (38 degrees C) accelerated transport of fragmented DNA in apical dendrites of the gerbil CA1 pyramidal neurons and increased dendrite-terminal fragmented DNA pooling in the apoptotic process following transient forebrain ischemia. The specific DNA fragmentation after the ischemic insult in gerbil hippocampus was examined by in situ nick-end-labeling method, and fluorescence DNA detection technique by DAPI was also performed. There is a precise temperature dependence for the migration of fragmented DNA from nuclei into apical dendrites of CA1 pyramidal cells during apoptosis following transient forebrain ischemia. Increase of fragmented DNA pooling is highly temperature sensitive, occurring at 38 degrees C, while at 39 degrees C there is a marked decrease in DNA pooling.

Animals↗
PubMed2000

Inhibitory effect of a proline-to-alanine substitution at codon 12 of peroxisome proliferator-activated receptor-gamma 2 on thiazolidinedione-induced adipogenesis.

Peroxisome proliferator-activated receptor-gamma (PPARgamma) is a member of the nuclear hormone receptor superfamily of transcription factors and appears to be a key regulator of adipogenesis. Members of the thiazolidinedione class of insulin-sensitizing agents act as high-affinity ligands for PPARgamma, indicating that PPARgamma is also important in systemic insulin action. To determine whether Pro(12) --> Ala (P12A) mutation in PPARgamma gene contributes to the development of obesity or insulin sensitivity, we examined the effects of the P12A mutation on the function of PPARgamma by expression of the mutant protein in COS or 3T3-L1 cells. The abilities of the P12A mutant of PPARgamma to mediate both transcriptional activation of a luciferase reporter gene construct containing the peroxisome proliferator response element and adipogenesis induced by a thiazolidinedione drug were reduced compared with those of the wild-type protein. These results suggest that the P12A substitution in PPARgamma gene may be associated with abnormalities of adipose tissue formation and insulin sensitivity.

3T3 Cells↗
PubMed2000

14-3-3tau associates with a translational control factor FKBP12-rapamycin-associated protein in T-cells after stimulation by pervanadate.

Proteins of the 14-3-3 family can associate with and/or modulate the activities of a variety of proteins, such as protooncogene and oncogene products, Cdc25 phosphatases and phosphatidylinositol 3-kinase, and thus are implicated in regulation of signaling pathways and the cell cycle. We report here that treatment of Jurkat T-cells with an inhibitor of protein tyrosine phosphatase, pervanadate, induces the association of 14-3-3tau with a translational control factor, FKBP12-rapamycin-associated protein (FRAP), with significant latter's autophosphorylation. Coimmunoprecipitation of various mutants of FRAP coexpressed with 14-3-3tau in COS-7 cells revealed that 14-3-3tau binds to the C-terminal side of FRAP at unknown site(s) different from the predicted binding motifs to date.

14-3-3 Proteins↗
PubMed2000

Mutations influencing the frr gene coding for ribosome recycling factor (RRF).

A total of 52 null, six reversion, and five silent mutations of frr (the gene encoding for ribosome recycling factor (RRF)) of Escherichia coli are discussed along with 12 temperature-sensitive (ts) mutations and 14 intergenic suppressor strains of ts RRF. The null mutations were classified into six different categories. A computer-based secondary structure analysis showed three domains; domain A which has the N-terminal helix, domain B which contains coil, alpha-helix and beta-strand structure, and domain C which is a C-terminal helix. The ts mutations fell into domains A and C but not in domain B. More than a half of the null mutations fell into domain B while the silent mutations fell outside domain B. Substitution of Arg132 in domain C by other amino acids was observed among five independently isolated null mutants. It is suggested that domain B is important for maintaining the RRF structure, while the region including Arg132 is one of the active sites. A total of 14 intergenic suppressor strains of ts RRF were grouped into four categories, depending on which temperature-sensitive alleles were suppressed.

Amino Acid Sequence↗
PubMed2000

AMY plaques in familial AD: comparison with sporadic Alzheimer's disease.

OBJECTIVE: To assess AMY expression in familial AD (FAD). BACKGROUND: The discovery of nonbeta-amyloid (Abeta), plaque-like deposits composed of a 100-kd protein (AMY) in sporadic AD (SAD) brains prompted us to determine whether these plaques (AMY plaques) also occur in AD due to mutations of the presenilin-1 (PS-1), presenilin-2 (PS-2), or the amyloid precursor protein (APP) genes. METHODS: We used immunohistochemistry and confocal laser scanning microscopy to probe the brains of 22 patients with FAD (13 with PS-1, 5 with PS-2, and 4 with APP mutations) and 14 patients with SAD. RESULTS: AMY plaques were present in all SAD and FAD brains, including an FAD/PS-1 brain from an individual with preclinical disease. The morphology of AMY plaques in SAD and FAD brains was indistinguishable, but they differed from Abeta deposits because AMY plaques lacked an immunoreactive core. AMY plaques sometimes colocalized with Abeta(x-42) deposits, but they did not colocalize with Abeta(x-40) plaque cores in either SAD or FAD brains. The percent of cortical area occupied by AMY was greater in FAD than in SAD brains (mean percent area = 9.8% and 5.9%, t = 2.487, p = 0.018). In particular, APP and PS-1 cases had more AMY deposition than PS-2 or SAD cases (12.9%, 10.5%, 6.2% in APP, PS-1, and PS-2 AD). CONCLUSIONS: AMY plaques are consistently present in familial AD due to presenilin-1 (PS-1), PS-2, and amyloid precursor protein mutations, and they can begin to accumulate before the emergence of dementia.

Aged↗
PubMed2000

Chemopreventive effects of coffee bean and rice constituents on colorectal carcinogenesis.

Polyphenolic compound chlorogenic acid (CGA) known to be much contained in coffee beans was found to have a regressive effect on induced aberrant crypt foci (ACF) as well as on development of ACF in azoxymethane (AOM)-induced colorectal carcinogenesis in rats. Rice germ and gamma-aminobutyric acid-enriched defatted rice germ inhibited AOM-induced ACF formation and colorectal carcinogenesis in rats. Ferulic acid (FA) also known to be contained in coffee beans and rice prevented AOM-induced ACF formation and intestinal carcinogenesis in rats. Both of food factors, coffee and rice may be of benefit to prevention of human colorectal cancers.

Animals↗
PubMed2000

Solitary myofibromatosis of the skull.

We present a case of solitary infantile myofibromatosis of the skull in a 3-month-old boy. A right parietal subcutaneous lump was found at birth, and it increased in size over the ensuing 3 months. Surgery was performed, and a diagnosis of myofibromatosis was confirmed histopathologically. Solitary myofibromatosis of the skull is extremely rare. The radiographical, CT, and MR appearances, as well as histopathological findings, are described in this article.

Humans↗
PubMed2000

MR analysis of nasopharyngeal carcinoma: correlation of the pattern of tumor extent at the primary site with the distribution of metastasized cervical lymph nodes. Preliminary results.

The purpose of this study was to correlate the pattern of tumor extent of nasopharyngeal carcinoma at the primary site on magnetic resonance (MR) imaging with the distribution of cervical lymph node metastasis. MR images of 32 patients with biopsy-proven nasopharyngeal carcinoma were reviewed and classified into five patterns of tumor extent in correlation with the distribution of cervical lymphadenopathy. The assessment of cervical lymph node metastasis was done on the basis of the computed tomography (CT) findings. The tumor volume was also correlated with the occurrence of contralateral lymphadenopathy. Of the 32 patients, five (16%) presented as type 1, tumor limited to the nasopharyngeal mucosa; 12 (38%) as type 2a, tumor which had invaded either lateral side but did not extend over the roof of nasopharynx; three (9%) as type 2b, tumor which had invaded bilaterally across the midline but did not extend over the roof of nasopharynx; three (9%) as type 2c, tumor which had invaded mainly the skull base but did not cross the midline; and nine (28%) as type 3, tumor which had extended anteriorly to the nasal cavity without invasion. Twenty-five patients (78%) demonstrated cervical lymphadenopathy. Patients with type 1, type 2b and type 3 spread had frequent bilateral cervical lymphadenopathy; those with type 2a had only ipsilateral lymphadenopathy. There was statistical significance (P < 0.005) regarding the existence of contralateral lymphadenopathy with midline tumors as well as the absence of contralateral cervical lymphadenopathy with non-midline tumors. This study therefore suggests that the distribution of metastasized lymph nodes depends on the pattern of tumor extent at the primary site.

Adolescent↗
PubMed2000

The local spread of lower bile duct cancer: evaluation by thin-section helical CT.

This study illustrates the local spread of lower bile duct cancer with thin-section helical CT in correlation with the surgical and pathological findings. Pathologically, 16 patients had pancreatic invasion, 4 had small bowel mesentery invasion, 7 had extrapancreatic nerve plexus invasion, and 3 patients had vascular invasion. On thin-section helical CT, pancreatic invasion was correlated to the clarity or non-clarity of the bile duct mass-pancreas border and the presence of an intrapancreatic mass. Cases with small bowel mesentery and extrapancreatic nerve plexus invasion showed mass or stranding around the superior mesenteric artery and/or inferior pancreatoduodenal artery. Vascular invasion was seen as tumor contiguity to these vessels.

Adenocarcinoma↗
PubMed2000

Naturally occurring and experimentally induced beta-amyloid deposits in the brains of marmosets (Callithrix jacchus).

Cerebral beta-amyloid occurs in elderly animals of some species and in Alzheimer's disease. Previously, we injected 3 young marmosets intracerebrally with brain tissue from a patient with Alzheimer's disease. Six years later, when the monkeys were middle aged, we found moderate numbers of intracerebral plaques and cerebrovascular deposits containing beta-amyloid. We have re-examined these brains and those of 10 other marmosets injected with brain homogenate containing beta-amyloid, and have found some beta-amyloid in animals injected more than 4 years previously. We have found beta-amyloid in 4 of 26 elderly control marmosets, but not in 9 young to middle-aged control marmosets. The beta-amyloid found in middle aged marmosets injected with Alzheimer brain tissue was, therefore, not a consequence of their age. Deposits in large cerebral vessels in elderly marmosets, and in marmosets previously injected with brain tissue containing beta-amyloid, reacted with antibodies to Abeta and Abeta1-40; plaques and microvessel deposits reacted with antibodies to Abeta and Abeta1-42.

Age Factors↗
PubMed2000

A 37-kDa peroxidase secreted from liverworts in response to chemical stress.

A peroxidase was purified from the culture medium of a suspension culture of Marchantia polymorpha (liverwort) after treatment with bornyl acetate, which acts as a chemical stress agent to the cells. The peroxidase was characterised as a glycoprotein of molecular mass 37-kDa having a pl of about 10 and an optimal pH of 6.5. The peroxidase was thermally stable at 50 degrees C for up to 60 min. The partial amino acid sequence of the peroxidase was determined and found to be dissimilar to the amino acid sequences of other higher plant peroxidases. The oxidative polymerization of lunularin by this peroxidase was examined and the formation of a dimer, a trimer and a tetramer was demonstrated by negative ion Fast Atom Bombardment (FAB)-mass spectroscopy of the reaction products.

Bibenzyls↗
PubMed2000

Minimally differentiated acute myeloid leukemia (AML-M0) with extensive erythrophagocytosis and del(20)(q11) chromosome abnormality.

We describe an 84-year-old woman who presented severe pancytopenia and 36.6% of blasts accompanied with erythrophagocytosis in the bone marrow. According to cytochemical and immunological findings, a diagnosis of minimally differentiated acute myeloid leukemia (AML-M0) was established. Cytogenetic analysis revealed del(20)(q11) which were previously reported for one case each of ALL and MDS associated with cytophagocytosis by blasts, leading us to speculate a disease entity. Interestingly, a high expression of mRNA of TNF-alpha was detected by RT-PCR on the bone marrow mononuclear cells.

Acute Disease↗
PubMed2000

Absolute number of circulating CD34+ cells is abnormally low in refractory anemias and extremely high in RAEB and RAEB-t; novel pathologic features of myelodysplastic syndromes identified by highly sensitive flow cytometry.

We scored absolute numbers of circulating CD34+ cells by a highly sensitive triple-color flow cytometric analysis using CD45 monoclonal antibody, CD34 monoclonal antibody and propidium iodide. Forty-one patients with MDS (RA: 27, RARS: 1, RAEB: 6, RAEB-t: 3,CMML: 4), 12 patients with aplastic anemia (AA) and 36 age-adjusted normal subjects were studied. RA had significantly decreased numbers of cells expressing CD34 (0.21 +/- 0.29 x 10(6)/l) compared with normal subjects (0.81 +/- 0.36 x 10(6)/l)(P < 0.001). This low number of CD34+ cells in RA resembles the case of AA (0.39 +/- 0.73 x 10(6)/l). In light-scatter analysis, the CD34+ cells of RA patients were distributed mainly in low forward scatter (FSC) (lymphocyte region). In contrast, the CD34+ cell counts were extremely high in patients with RAEB (46.54 +/- 71.37 x 10(6)/l) and RAEB-t (57.00 +/- 52.36 x 10(6)/l) (P < 0.001) and the CD34+ cells were observed in high FSC (blast region).CMML patients showed moderately increased numbers of CD34+ cells (3.69 +/- 4.64 x 10(6)/l). Thus, there was a distinct difference in cell size and number of circulating CD34+ cells between RA and RAEB/RAEB-t. In univariate and multivariate analysis, a high CD34+ cell count (> or = 1.0 x 10(6)/l) was a poor prognostic factor. This method allows one to distinguish RA from other MDS subtypes more reliably than by morphology alone and provides early signs of progression to acute leukemia.

Adult↗
PubMed2000

Action of chlorogenic acid in vegetables and fruits as an inhibitor of 8-hydroxydeoxyguanosine formation in vitro and in a rat carcinogenesis model.

Various plant extracts, such as carrot, burdock (gobou), apricot and prune, showed inhibitory effects in an in vitro assay of lipid peroxide-induced 8-hydroxydeoxyguanosine (8-OH-dG) formation. The major inhibitor purified from various plants extracts was identified as chlorogenic acid (CA), on the basis of UV- and mass-spectra and comparison with a standard sample. To examine whether CA also inhibits 8-OH-dG formation in animal organs, an oxygen radical-forming carcinogen, 4-nitroquinoline-1-oxide, was administered to rats, with or without CA. The 8-OH-dG level in the DNA of the rat tongue, the target organ, was significantly reduced in the CA-treated group.

4-Nitroquinoline-1-oxide↗