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Biomedical subjects

Y Higuchi

Publications and source records attributed to Y Higuchi.

At least 163 records · Page 9Linked to original sources
PubMed1995

Different time-course production of peptidic and nonpeptidic leukotrienes and prostaglandins E2 and F2 alpha in the ovary during ovulation in gonadotropin-primed immature rats.

Temporal changes in ovarian leukotrienes (LTs) and prostaglandins (PGs) were examined during ovulation to assess roles they may play in this process. Ovulation was induced in immature rats by injection with human chorionic gonadotropin (hCG; 10 IU, s.c.) 2 days after they had been primed with pregnant mare serum gonadotropin (10 IU, s.c.). The ovaries were extirpated at various intervals after hCG administration and assayed for LTB4, and LTC4/D4/E4, as well as PGE2, and PGF2 alpha. Ovarian concentration of LTB4 increased (P < 0.01) rapidly, reaching a peak at 1 hour after hCG administration, then declined (P < 0.05) by 4 hours and remained low thereafter. In contrast, LTC4/D4/E4 peaked (P < 0.01) between 1 and 2 hours, declined (P < 0.05), and then increased (P < 0.01) to achieve a second, larger peak at 10 hours. Prostaglandin E2 increased (P < 0.01) at 6 hours after hCG and did not decrease from the peak value until (P < 0.01) 14 hours after hCG. Concentrations of PGF2 alpha increased (P < 0.01) at 4 hours after hCG, but decreased (P < 0.01) from the peak by 10 hours. Although LTB4, LTC4/D4/E4, PGE2, and PGF2 alpha all increased during ovulation, the time-course differed. This suggests that each eicosanoid may play a distinct role in the process of follicular rupture.

Animals↗
PubMed1995

Marsupialization of cystic ameloblastoma: a clinical and histopathologic study of the growth characteristics before and after marsupialization.

PURPOSE: This study evaluated the effectiveness of marsupialization for the treatment of cystic ameloblastoma. MATERIALS AND METHODS: Clinical and histologic examination of 24 cystic ameloblastomas were performed before and after marsupialization. RESULTS: Clinically and radiographically, the effect of marsupialization was evaluated as extremely effective (five cases), effective (11 cases), and noneffective (eight cases). Marsupialization was most effective in teenaged patients. In three cases, the tumor disappeared macroscopically, and further surgery was not done. Histologically, the growth characteristics of the tumor were classified into expansive and invasive types. Cytologic pattern was classified into three types according to the outer cell layer of the tumor parenchyme: cuboidal cell, columnar cell, and basal cell. Premarsupialization, the expansive pattern with the cuboidal cell type was dominant, whereas for postmarsupialization many cases that had been expansive changed to an invasive type showing columnar or basal cell types. CONCLUSION: Marsupialization was found to be useful as a preliminary treatment of the cystic ameloblastoma. However, it must be borne in mind that following marsupialization the tumor still has a potential to infiltrate into the surrounding tissues.

Adolescent↗
PubMed1995

Neurodegeneration in the limbic and paralimbic system in progressive supranuclear palsy.

Progressive supranuclear palsy is neuropathologically characterized by neuronal degeneration of the basal ganglia, brain stem, and cerebellum. In addition, cortical neuronal degeneration associated with neurofibrillary tangles formation has been identified over wide areas of the brain in patients with progressive supranuclear palsy. We studied the distribution of alpha B-crystallin-positive degenerating neurons in cases with progressive supranuclear palsy, and compared them with those in Pick's disease. Alzheimer's disease, senile dementia of Alzheimer type, and normal aged individuals. A large number of alpha B-crystallin-positive neurons was found in the cerebral cortices of four out of nine patients with progressive supranuclear palsy. In particular, alpha B-crystallin-positive ballooned neurons were frequently observed in deep cortical pyramidal cell layers of the limbic and paralimbic systems in these diseases. The involvement of the limbic and paralimbic systems may thus contribute to personality changes as well as to memory and cognitive impairment in some patients with progressive supranuclear palsy.

Aged↗
PubMed1995

Bone marrow neutrophilia and suppressed bone turnover in human interleukin-6 transgenic mice. A cellular relationship among hematopoietic cells, osteoblasts, and osteoclasts mediated by stromal cells in bone marrow.

To elucidate the effect of interleukin-6 (IL-6) on bone and bone marrow (BM), human IL-6 transgenic mice (hIL-6 tgm) were produced. Their bone and BM were examined histologically, radiologically, histomorphometrically, and hematologically on a temporal basis. hIL-6 tgm showed histologically evident neutrophilia in BM. Increase in precursors of granulocytes and monocytes in hIL-6 tgm was demonstrated by an assay for colony forming unit in culture (CFU-C) of BM cells. Decrease in osteoblasts and osteoid and suppression of primary spongiosa formation were predominantly observed in hIL-6 tgm at 14 weeks old, the terminal stage of life for hIL-6 tgm. An assay for colony forming unit in fibroblastic (CFU-F) of BM cells revealed a decrease in osteoblast precursor (with regard to alkaline phosphatase-positive colonies) in hIL-6 tgm at 15 weeks old. Histomorphometry demonstrated a decrease of both osteoclast number and bone resorption in hIL-6 tgm. These results suggested that enhanced granulocytic hematopoiesis, suppressed bone turnover, and alteration of cellular population in stromal cells in BM occurred in hIL-6 tgm. Thus we provide new findings that facilitate understanding of cellular interrelationships among hematopoietic cells, osteoblasts, and osteoclasts mediated by stromal cells in BM.

Animals↗
PubMed1995

[Falls among the elderly living in a rural community--prevalence and circumstances of falls by season].

The purpose of the study is to assess the prevalence and circumstances of falls by season among the elderly living in a rural community. From 1992 to 1993 four interview surveys on falls were conducted every three months. Out of the total 1,321 subjects aged 65 and over (male: 532, mean age: 73.2 yr, female: 789, mean age: 74.5 yr), 1,317 responded to the survey in summer, 1,306 in autumn, 1,236 in winter and 1,248 in spring. The prevalence of falls (the rate of subjects with falls) were 7.4% in summer, 5.9% in autumn, 6.5% in winter and 6.7% in spring. The seasonal variation was not statistically significant. In each season, there was no significant difference between genders. The prevalence in the older group aged 75 and over is higher than that in younger group aged 65-74 except in spring. As to the circumstances of falls, there were seasonal differences in the distribution of place, footwear and cause of falls. These differences may be due to the climate of the area.

Accidental Falls↗
PubMed1995

Total colectomy and ileorectal anastomosis in ulcerative colitis.

In an attempt to determine the best indications for the classically adopted ileo-rectal anastomosis (IRA) and the new techniques of restorative proctocolectomy, namely, ileal J-pouch-anal anastomosis (IAA) ilea J-pouch-anal canal anastomosis (IACA), we retrospectively studied 72 surgically treated patients with ulcerative colitis (UC) followed in our surgical department in the period between 1963 and 1994. Compared to these new techniques, IRA had a lower incidence of postoperative fecal incontinence, and was one-stepped in the majority of the patients. No significant difference regarding postoperative bowel function, operation time, volume of bleeding, hospital stay, and the need for postoperative prednisolone was observed. We concluded that IRA is a good procedure that is indicated for patients receiving high-dose prednisolone, for those who need a quick return to social activity, and for those with poor anal function. IACA is a good indication for those patients with good anal function assessed preoperatively, who agree to receive a multi-step operation. For those patients with cancer or dysplasia, IAA should be the operation of first choice.

Anal Canal↗
PubMed1995

Results of cancer surveillance in ulcerative colitis.

A total of 144 patients with total or left-sided colitis of 7 years or more duration were enrolled in a surveillance program to screen for dysplasia at Tokyo University Hospital between 1979 and 1994. The program consisted of an annual colonoscopy, with multiple biopsies being performed at 10-cm intervals in the colonic flat mucosa; additional biopsies were taken from elevated lesions. A higher proportion of patients who had had four surveillance colonoscopies or more up to the detection of carcinoma had an earlier stage of carcinoma compared with patients who had had less than three colonoscopies. In addition, the incidence and stage of carcinoma were higher in the patients with an initially higher grade of dysplasia and in those patients with elevated lesions compared with patients with flat mucosal lesions with the same grade of dysplasia. Microspectrophotometric DNA analysis was performed for 66 consecutive patients who had been under surveillance between 1987 and 1990. Dysplasia and carcinoma occurred at a higher rate in patients who had an initial abnormal DNA content compared with patients who showed diploidy. These findings indicate that surveillance colonoscopy with DNA analysis could be useful in the early detection of colonic carcinoma in long-standing ulcerative colitis.

Biopsy↗
PubMed1994

Cloning and characterization of the human osteopontin gene and its promoter.

We isolated the human osteopontin (hOP) gene and the 5' upstream region, and analysed its exon-intron structure and potential regulatory sequences of the promoter region in comparison with those of the mouse and porcine gene. The coding sequence is split into 7 exons which are similar to those of the mouse gene, although the hOP gene is longer than the mouse gene. The difference in length is mainly due to variations in intron 3, which is approximately 2.7-fold longer than that of the mouse OP gene. The 5' upstream region of the hOP, which is highly conserved up to nucleotide -250, contains a number of potential cis regulatory consensus sequences. A series of sequentially 5'-deleted chimeric clones was tested for the ability to stimulate chloramphenicol acetyltransferase (CAT). Initial CAT analysis demonstrated that nucleotides at positions -474 to -270, -124 to -80, and -55 to -39 contained cis-acting enhancing sequences in a human monocyte cell line, SCC-3, although the -124 to -80 region was much more active than other regions. Deletion of the sequences between -474 and -270 localized this cis region to the sequence at positions -439 to -410, whereas the deletion between -124 to -80 localized the regions to -124 to -115, and -94 to -80. Gel-shift analysis using as probes synthesized double-stranded DNA corresponding to the 10 and 15 bp region at positions -124 to -115 and -94 to -80 respectively revealed that each probe formed a major band complexed with nuclear proteins prepared from SCC-3 cells.

Amino Acid Sequence↗
PubMed1994

Location of active sites of NiFe hydrogenase determined by the combination of multiple isomorphous replacement and multiwavelength anomalous-diffraction methods.

The active centers of NiFe hydrogenase from Desulfovibrio vulgaris Miyazaki F have been located in the electron-density map calculated at 4 A resolution. The electron-density map based on five heavy-atom derivatives showed four strong peaks which were clearly distinguished from the protein region. These strong densities have been successfully assigned to three iron-sulfur clusters and one Ni atom by a difference Fourier technique with coefficients of the best phases from the multiple isomorphous replacement (MIR) method and structure factors obtained at five wavelengths (1.040, 1.487, 1.730, 1.743 and 1.750 A) with the use of a synchrotron radiation source. Four active centers are approximately lined up at a distance of ca 13 A, which seems reasonable if they are connected with the electron-transfer chain.

Journal Article↗
PubMed1994

Motilin induces the endothelium-dependent relaxation of smooth muscle and the elevation of cytosolic calcium in endothelial cells in situ.

Using front-surface fluorometry with fura-2 and porcine aortic valvular strips, we investigated the effect of motilin, a gastrointestinal peptide, on the cytosolic Ca2+ concentration ([Ca2+]i) of endothelial cells in situ. Motilin induced a biphasic elevation of [Ca2+]i of the endothelial cells on the porcine aortic valvular strips. To investigate the physiological role of these Ca2+ transients in the endothelial cells, we determined the effect of motilin on [Ca2+]i as well as the tension of the smooth muscles in the porcine coronary strips with an intact endothelium. Motilin decreased [Ca2+]i and the tension of the coronary smooth muscle precontracted by U46619, a thromboxane A2 analogue, in an endothelium-dependent manner. In the presence of indomethacin (a cyclooxygenase inhibitor), motilin induced an endothelium-dependent relaxation of the coronary strips which was partially inhibited by N omega-nitro-L-arginine (L-NNA; a NO synthase inhibitor). These results thus indicate that motilin induces Ca2+ transients of the endothelial cells while it also induces vasorelaxation, which may be mediated by both L-NNA sensitive and resistant factors that are derived from the endothelium.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1994

Zonisamide reduces hypoxic-ischemic brain damage in neonatal rats irrespective of its anticonvulsive effect.

The neuroprotective effect of a novel anticonvulsant, zonisamide, was investigated in neonatal rats with hypoxic-ischemic brain damage. Rats underwent left carotid ligation followed by hypoxic exposure (8% O2) for 2.5 h. When zonisamide (75 mg/kg) was administered i.p. 1 h before hypoxia, it reduced the cortical infarction volume to 6 +/- 5% (mean +/- S.E.M.) from 68 +/- 7% in vehicle-treated controls and the striatal volume to 8 +/- 4% from 78 +/- 7%. Zonisamide also reduced neuronal necrosis in 5 hippocampal regions (the dentate gyrus, CA4, CA3, CA1, and the subiculum). The plasma zonisamide concentration before and after hypoxia was 47.9 +/- 2.0 microgram/ml and 42.3 +/- 3.9 microgram/ml, respectively. Epidural electrodes were implanted in 6 pups one day before hypoxia-ischemia. Electroencephalograms were recorded during hypoxia-ischemia in rats given zonisamide or vehicle before the insult. The intensity of seizure activities was similar in the zonisamide-treated pups and the vehicle-treated controls. These findings demonstrate that zonisamide reduces neonatal hypoxic-ischemic brain damage and that this protective effect does not depend on its anticonvulsant action.

Animals↗
PubMed1994

Upregulation of mouse CD14 expression in Kupffer cells by lipopolysaccharide.

Western blot analysis showed that a monoclonal antibody against recombinant mouse CD14 (mCD14), designated rmC5-3, specifically reacted with mouse macrophage cell line J774, but not myeloma cell line NS1. Fluorographic and immunocytochemical analysis demonstrated specific binding of rmC5-3 with mouse resident macrophages, inflammatory monocytes and neutrophils, and macrophage cell lines. Immunohistochemical staining using rmC5-3 showed that CD14-positive Kupffer cells (KC) were small in number in the liver in nonstimulated mice. The number of stained KC, which were rich in the midzonal and periportal regions, gradually increased with time after intraperitoneal injection of lipopolysaccharide (LPS), peaked 6 h after injection, and returned to normal by 20 h after injection. Staining intensity over time was proportional to the number of KC. A slight increase in mCD14 expression was observed in peritoneal macrophages 2 h after LPS administration in vivo using flow cytometric analysis. mCD14 mRNA became detectable at 1 h after the intraperitoneal injection of LPS (20 micrograms/mice), and the level dramatically increased with time, peaking at 3 h, and sharply dropped at 6 h. The resident peritoneal macrophages demonstrated a constitutively high mCD14 mRNA expression, which slightly increased 2 h after LPS (100 ng/ml) stimulation in vitro. The level of mCD14 expression in macrophages did not increase after intraperitoneal injection of LPS (20 micrograms/mice).

Animals↗
PubMed1994

Enhancement of murine serum amyloid A3 mRNA expression by glucocorticoids and its regulation by cytokines.

Macrophages are regulated by hormones, cytokines, and other substances. We examined the effects of glucocorticoids (GC) on serum amyloid A (SAA) mRNA expression using an antisense SAA3 probe, and found that dexamethasone (DEX) and triamcinolone (TC) increased SAA3 mRNA expression by macrophage cell lines in a time- and concentration-dependent manner. Both an RNA polymerase II antagonist, alpha-amanitin, and a specific GC antagonist, RU38486, inhibited the enhancement of SAA3 mRNA expression by DEX. These results show that GC lead to enhanced SAA3 mRNA transcription. Nuclear run-on experiments supported these results. Enhanced expression of SAA3 mRNA by DEX was accompanied by production of SAA3 protein. Interferon-gamma (IFN-gamma) alone showed any effect on SAA3 mRNA expression. Enhanced SAA3 expression by DEX was inhibited by treatment with IFN-gamma in a dose-dependent manner. Either transforming growth factor (TGF)-beta 1 or interleukin (IL)-4 alone showed no effect on SAA3 mRNA expression, but suppressed DEX-induced SAA3 expression. The timing of the effects of IFN-gamma and TGF-beta 1 on DEX-induced SAA3 expression differed: IFN-gamma showed its effect between 30 h before and 18 h after DEX administration, whereas TGF-beta 1 showed an effect when administered concomitantly with DEX and in the late stages after DEX administration. IL-4 mildly suppressed DEX-induced SAA3 expression when given 12 h before and after DEX administration.

Animals↗
PubMed1994

A novel synthetic vitamin D analogue, 2 beta-(3-hydroxypropoxy)1 alpha, 25-dihydroxyvitamin D3 (ED-71), increases bone mass by stimulating the bone formation in normal and ovariectomized rats.

We performed dosing experiments to evaluate the bone mass increasing action of a novel, synthetic vitamin D derivative, 2 beta-(3-hydroxypropoxy)-1 alpha,25(OH)2D3 (ED-71), in normal and estrogen-deficient rats. The first experiment consisted of 31 Sprague-Dawley rats, 28 weeks of age. The second experiment consisted of 44 animals who were ovariectomized (OVX) or sham operated at the age of 12 weeks. ED-71 was given twice a week for the duration of 12 weeks. At the end of the experiments, serum chemistries were examined and lumbar vertebrae were assessed histomorphometrically. Serum alkaline-phosphatase levels tended to decrease by ED-71 administration in the first experiment and their elevated values after ovariectomy were also depressed by ED-71 in the second experiment. Serum osteocalcin levels, however, increased by the agent. In the first experiment, cancellous bone volume (BV/TV) increased dose dependently. Bone formation rates (BFR/BS) also increased. In the second experiment, BV/TV significantly decreased by ovariectomy and it increased in ED-71-treated groups, but not in 1 alpha-(OH)D3-treated group. BFR/BS increased by ED-71. Activation frequency did not decrease by ED-71 in either experiment. These data clearly demonstrated that ED-71 administration was capable of increasing the bone mass by stimulating bone formation in normal and estrogen-deficient rats.

Alkaline Phosphatase↗
PubMed1994

Florid cemento-osseous dysplasia. Radiographic study with special emphasis on computed tomography.

This article describes the computed tomographic and conventional radiographic findings for florid cemento-osseous dysplasia. A low-density thin layer or cystlike area was observed around the high-density masses in the tooth-bearing area in the seven cases studied. Expansion of the buccal and lingual cortical plates was observed in association with cystlike areas, but was infrequently observed in florid cemento-osseous dysplasia not having such areas. The computed tomographic number of the high-density masses ranged from 772 to 1587 Hounsfield Units and was equivalent to that of cementum or cortical bone.

Adult↗
PubMed1994

Radiographic patterns of osteomyelitis in the mandible. Plain film/CT correlation.

Mandibular osteomyelitis often is associated with involvement of the masticator space. Assessment of mandibular osteomyelitis should therefore involve assessment of soft tissue involvement of the lesion. The purpose of this study was to clarify the relationship between computed tomography patterns and the presence of inflammation in soft tissues. Thirty-three cases diagnosed with osteomyelitis of the mandible were analyzed radiologically with conventional radiographs and with computed tomography scans. Computed tomography patterns of osteomyelitis were classified into four types, lytic, mixed, sclerotic, and sequestrum patterns. Location, extent of the lesion, and change of the cortical plate were evaluated and compared with conventional radiographic findings. Mixed pattern cases displayed diffuse bone abnormalities, which sometimes were accompanied by cortical plate disruption and periosteal reaction. In addition, most mixed pattern cases showed soft tissue involvement, especially of the masseter muscle. Inflammation of the masseter muscle was found to be related to periosteal reaction and disruption of the buccal cortical plate. The data demonstrate a close interaction between cortical plate disruption and muscle inflammation. The extent of inflammation including soft tissue involvement was better appreciated with computed tomography in osteomyelitis, especially in mixed pattern cases.

Adolescent↗
PubMed1994

A detailed comparison of the refined structures of cytochrome c3 molecules from two strains in Desulfovibrio vulgaris: the relationship between the heme structures and their redox properties.

The refined structures of the cytochrome c3 molecules from Desulfovibrio vulgaris Miyazaki and Hildenborough have been compared in detail. Though there are no significant differences of the overall structure and spatial arrangement of four heme groups between two molecules, there are some unique features with regard to the local structures near the heme pockets. Two of the heme groups show significant differences including a hydrogen bonding scheme between the imidazole rings and water molecules in heme pocket. The water molecule near the heme 1 pocket in Miyazaki cytochrome c3 is replaced by the C delta 1 atom of Leu9 in the Hildenborough structure. The rotation around the C alpha-C beta bond of Leu9 results in the increase of the solvent accessibility of the portion of the heme 1 edge. On the other hand, in heme3 one water molecule is additionally included in the hydrogen bonding network with a N delta 1 atom of the imidazole ring and carbonyl oxygen atom of the main chain in Hildenborough cytochrome c3. This additional hydrogen bonding network will contribute to the possible passage between the imidazole ring and the molecular surface. These features have been related to the upfield shift of the C2 proton signals of NMR spectra and the low redox potentials of the cytochrome c3 molecules of Desulfovibrio vulgaris Hildenborough in comparison with those from Miyazaki.

Amino Acid Sequence↗