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Biomedical subjects

Y Tokunaga

Publications and source records attributed to Y Tokunaga.

At least 73 records · Page 4Linked to original sources
PubMed1999

Prop-1 gene expression in human pituitary tumors.

A novel type of pituitary-specific transcription factor, Prophet of Pit-1 (Prop-1) gene (PROP1), expresses in just early embryonic stage in mouse and closely related as a causative gene in combined pituitary hormone deficiency. We studied PROP1 expression to further clarify its correlation with tumorigenesis and biological behavior in human pituitary adenomas. Eighteen pituitary adenomas and three normal pituitary glands were examined for the expression of PROP1 and POU1F1 by using RT-PCR Pituitary adenomas were diagnosed as non-functioning adenomas (n = 11), prolactinomas (n=5), GH-producing adenoma (n = 1) and ACTH-producing adenoma (n = 1). One of non-functioning adenomas was pituitary carcinoma with cerebellar metastasis and CSF dissemination. Our results demonstrated PROP1 expression in all pituitary tumors examined, in contrast, POU1F1 was detected in 14 of pituitary tumors. PROP1 was also expressed in normal pituitary gland, however, it was not in normal brain tissue, glioblastomas (cell lines and tumor tissues) and meningioma. Our data indicated that PROP1 expression was observed constantly both in the pituitary tumors and normal human adult pituitary tissues, suggesting that PROP1 is an essential transcriptional factor for pituitary specific gene expression in human. Therefore, detection of PROP1 might be a useful indicator for differentiating pituitary adenomas, regardless of their hormonal phenotypes, from other brain tumors.

Adenoma↗
PubMed1999

Dietary effect of guar gum and its partially hydrolyzed product on the lipid metabolism and immune function of Sprague-Dawley rats.

The dietary effect of the water-soluble dietary fibers (WSDF), guar gum, partially hydrolyzed guar gum (PHGG), glucomannan, highly methoxylated (HM) pectin, on the serum lipid level and immunoglobulin (Ig) production of Sprague-Dawley rats was compared with that of water-insoluble cellulose. Although serum total cholesterol and triglyceride levels were significantly lower in the rats fed with WSDF than in those fed with cellulose, a decrease in the level of phospholipids was only observed in the rats that had been fed on guar gum or glucomannan. In addition, all WSDF feeding enhanced IgA productivity in the spleen and mesenteric lymph node lymphocytes, although the increase in serum IgA level was only observed in the rats fed on WSDF, and not on PHGG. When mesenteric lymph node lymphocytes were cultured in the presence of various concentrations of guar gum or glucomannan, no significant increase in Ig production was apparent. These data suggest that WSDF indirectly enhanced the Ig production of lymphocytes, and that serum lipid reduction and IgA production-enhancing activities of WSDF were dependent on their molecular sizes.

Animals↗
PubMed1999

Ets-1 transcription factor-mediated urokinase-type plasminogen activator expression and invasion in glioma cells stimulated by serum and basic fibroblast growth factors.

Overexpression of urokinase plasminogen activator (uPA) has been proposed to be one of the mechanisms by which malignant glioma cells cause pericellular proteolysis of stromal structures during brain-tissue invasion. However, knowledge about the mechanisms that regulate uPA in glioma cells is still rather scant. Growth factors, particularly epidermal growth factor and basic fibroblast growth factor (bFGF), regulate uPA synthesis in various nonglial cells. Because these factors have been associated with glioma invasion, we thought that perhaps similar events may occur in glioma cells. In this study, we demonstrate that growth factors regulate uPA gene transcription in glioma cells by induction of Ets-1 transcription factor. Serum and bFGF treatment concomitantly stimulated baseline levels of Ets-1 and uPA mRNA and protein, and this was associated with a marked increase in the migration and invasion potentials of glioma cells in vitro. Treatment of cells with antisense Ets-1 but not the control sense oligonucleotides concurrently inhibited the expression of Ets-1 and uPA, and this blocked glioma cell migration and invasion by more than 50%. In addition, medium conditioned by antisense Ets-1 oligonucleotide-treated cells showed markedly reduced uPA activity, as determined by casein zymography. These results strongly suggest that serum and bFGF control glioma invasion by inducing synthesis of Ets-1 transcription factor, which directly up-regulates expression of uPA in glioma cells. Antisense inhibition of Ets-1 expression may therefore provide a potential and exciting therapeutic target for preventing invasion by glioma cells.

Blood↗
PubMed1999

[Peripheral blood stem cell transplantation--practices of mobilization and harvest].

Recently, mobilized peripheral blood stem cells (PBSC) are increasingly used as an alternative to bone marrow for engrafting procedures. Chemotherapy followed by recombinant human granulocyte-colony stimulating factor (rhG-CSF) or rhG-CSF alone are the most commonly used PBSC mobilization schedules. Current timing of apheresis has now been yet decided on time by flowcytometric analysis of CD34 positivity of peripheral blood whole white cell count. Because apheresis procedure has been established quite well, PBSC harvest procedure becomes fast, safe and stable.

Blood Component Removal↗
PubMed1998

Immunohistochemical analysis of metallothionein in astrocytic tumors in relation to tumor grade, proliferative potential, and survival.

BACKGROUND: Metallothionein (MT) is the name for a family of predominantly intracellular protein thiol compounds involved in anticancer drug resistance. For certain tumors, MT is related to grade of tumor malignancy and prognosis. The authors evaluated the expression of MT in 114 astrocytic tumors in relation to the proliferative potential of tumors and the survival of patients. METHODS: Paraffin embedded tissue sections were stained with monoclonal anti-metallothionein and MIB-1 Ki-67 antibodies by avidin-biotin complex immunohistochemistry. RESULTS: MT expression was observed in 2 of 6 pilocytic astrocytomas, in 10 of 24 Grade 2 astrocytomas, in 16 of 25 anaplastic astrocytomas, and in 47 of 59 glioblastomas. In addition to the tumor cells, microvascular endothelial proliferation and smooth muscle of tumor vessel walls were frequently MT positive. The glioblastomas had a significantly higher percentage of MT positive cells compared with low grade (P < 0.0001) and anaplastic (P < 0.04) astrocytomas. MT expression in astrocytomas had no correlation with tumor recurrence. The mean Ki-67 labeling index (LI) was significantly higher in the high grade (3-4) compared with the low grade (1-2) astrocytomas. MT positive astrocytic tumors had statistically significantly higher mean Ki-67 LI compared with MT negative tumors, irrespective of histologic grade. Although the levels of MT and Ki-67 LI varied in individual tumors, the mean Ki-67 LI increased in parallel to the increasing MT staining grade, and this difference attained statistical significance only for glioblastoma. MT positive anaplastic astrocytoma and glioblastoma patients did not survive as long as the MT negative patients, although this difference attained statistical significance only for anaplastic astrocytoma. CONCLUSIONS: The current study suggests that MT might play a significant role in the growth of astrocytic tumors, with an acquired enhanced ability to produce MT as the malignant potential of a tumor increases.

Adolescent↗
PubMed1998

Compact superconducting ring at ritsumeikan university.

A compact superconducting storage ring (0.575 GeV and 300 mA) with a racetrack microtron injection system was installed at Ritsumeikan University and has been operated successfully since April 1996. As the radius of the circular electron orbit is small (0.5 m), it is possible to use a radiation beam of relatively high photon flux at a short distance from the source point. Beamlines have been constructed including those for XAFS, soft X-ray spectroscopy, VUV spectroscopy, fluorescent X-ray analysis, soft X-ray microscopy, X-ray diffraction/scattering and photoelectron spectroscopy; the photoelectron spectrometer is combined with an ion-beam-scattering spectrometer to obtain information both on the electronic states and on the atomic arrangements of a solid surface. In addition there are two beamlines, one for LIGA exposure and the other for synchrotron radiation ablation, which are devoted to producing new devices and materials. The synchrotron radiation facility is open not only to users in the University but also to researchers in industry, governmental institutions and other universities.

Journal Article↗
PubMed1998

A novel junction-like membrane complex in the optic nerve astrocyte of the Japanese macaque with a possible relation to a potassium ion channel.

BACKGROUND: A new type of junction-like membrane complex (JMC) was detected between adjacent astrocytes in the optic nerve of Japanese macaque (macaca fuscata). This membrane complex morphologically resembled a cell junction, but a possible role for potassium ion channels could not be denied based on freeze-fracture replica observation. We attempted to determine the chemical nature and function of the novel JMC. METHODS: Using an electron microscope, we observed JMCs in the optic nerve astrocyte. In addition, we observed them using a freeze-fracture replica and immunohistochemistry with connexin 43, a gap junction specific protein. Furthermore, immunolocalization of an inwardly rectifying potassium ion channel, K(AB)-2 (Kir4.1), was studied with a confocal laser-scanning microscope, and an electron microscope using a newly developed pre-embedding method. RESULTS: These JMCs were abundant around the blood vessel in the area just behind the lamina cribrosa. At JMCs the inner leaflet was thicker than the outer leaflet and electron-dense materials were packed in the intercellular space. Freeze-fracture replica observation revealed orthogonal arrays of particles, probably at the place of JMCs, that have been considered a potassium ion channel. No connexin 43 immunoreactivity was detected in JMCs, while K(AB)-2 was mostly localized on either side of the opposing cell membranes of JMC. CONCLUSIONS: These JMCs do not seem to be a simple junction, but relate to a potassium ion channel. The area just behind the lamina cribrosa may be important in terms of conductance of the optic nerve impulse.

Amino Acid Sequence↗
PubMed1998

Antiinflammatory potency of dehydrocurdione, a zedoary-derived sesquiterpene.

OBJECTIVE AND DESIGN: Dehydrocurdione, a sesquiterpene isolated from zedoary, was tested for in vivo and in vitro antiinflammatory actions. MATERIALS: Analgesic effect was tested in ICR mice by the acetic acid-induced writhing method. Antipyretic effect was studied in Sprague-Dawley rats treated with baker's yeast. Antiinflammatory activities were tested in Wistar rats with carrageenan-induced paw edema and adjuvant-induced chronic arthritis. In vitro analyses included the capabilities to inhibit cyclooxygenase activity, and to scavenge free radicals as determined by electron paramagnetic resonance (EPR). RESULTS: Oral administration of dehydrocurdione (40 to 200 mg/kg) mitigated the writhing reflex. induced by acetic acid and the fever elicited by baker's yeast. A higher dose (200 mg/kg) of dehydrocurdione was required to inhibit the carrageenan-induced paw edema. Oral administration of dehydrocurdione at 120 mg/kg/day for 12 days significantly reduced chronic adjuvant arthritis. Unlike indomethacin (IC50: 0.1 microM), dehydrocurdione showed minimal cyclooxygenase inhibition. However, dehydrocurdione (100 microM to 5 mM) significantly reduced free radical formation from hydrogen peroxide and ferrous iron determined by EPR spectrometry using 5,5'-dimethyl-1-pyrroline-N-oxide as a spin trap agent. CONCLUSION: In addition to the well-known effect of zedoary as a stomachic, dehydrocurdione, the major component of Curcuma zedoaria Roscoe has antiinflammatory potency related to its antioxidant effect.

Acetic Acid↗
PubMed1998

Spontaneous perforation of the rectum with possible stercoral etiology: report of a case and review of the literature.

Stercoral perforation of the colon or rectum is a rare cause of acute abdomen, with fewer than 70 cases documented in the literature. We report herein the case of a 60-year-old man who presented with anuria and epigastric pain with physical signs of peritonitis. An abdominal X-ray showed bilateral subphrenic free air accumulation, and an emergency laparotomy subsequently revealed perforation of the rectum, suggestive of a stercoral cause, which was treated by simple closure after debridement. Following an uneventful postoperative course, he was discharged from the hospital 3 weeks after his operation and is now doing well without having suffered any further gastrointestinal problems. The clinical features, diagnosis, and treatment of the disease are reviewed following the presentation of this case. Surgeons should be aware of the possibility of this fatal disease, despite its rare incidence. Furthermore, it is important to recognize the condition at an early stage because it has a significantly high mortality if not treated early. Conversely, the surgical outcome is satisfactory provided surgery is performed in due time.

Debridement↗
PubMed1998

Development of approximate formula for LDL-chol, LDL-apo B and LDL-chol/LDL-apo B as indices of hyperapobetalipoproteinemia and small dense LDL.

Estimation of LDL-chol and LDL-apo B is useful for the diagnosis of hyperapobetalipoproteinemia (normal LDL-chol with increased LDL-apo B), which is one of the most commonly occurring lipoprotein disorders associated with atherosclerotic cardiovascular diseases. The LDL-chol/LDL-apo B ratio reflects the level of small dense LDL, which is an important risk factor for IHD, CVD and ASO. In order to estimate LDL-apo B and LDL-chol/LDL-apo B ratio from blood chol, TG, HDL-chol and apo B values, we developed a formula for LDL-chol ¿0.94Chol- 0.94HDL-chol - 0.19TG¿, LDL-apo B ¿apo B - 0.09Chol + 0.09HDL-chol-0.08TG¿, and LDL-chol/LDL-apo B [¿0.94Chol-0.94HDL-chol - 0.19TG¿/¿apo B - 0.09Chol + 0.09HDL-chol-0.08TG¿] using ultracentrifugal data from 2179 subjects. These were calculated by the least squares method on the assumption that a certain compositional relationship exists between Chol, TG and apo B in VLDL, IDL and LDL. Friedewald's formula for LDL-chol (Chol - HDL-chol - 0.2TG) includes IDL-chol, but the present new formula theoretically excludes IDL-chol. It suggests a better estimation for the correct LDL-chol. Estimated LDL-apo B is useful for the diagnosis of hyperapobetalipoproteinemia and detection of small dense LDL. Without performing ultracentrifuge, additional information is obtained for the quantitative and qualitative alteration of LDL, such as small dense LDL. The above formulae and a new classification of lipoproteinemia including apo B were applied to the analyses of lipoprotein profiles of subjects with cardiovascular diseases, which were compared with those in the general population. Hyperapobetalipoproteinemia with high TG was observed 2-3 times more frequently in subjects with CAD, MI and ASO than in the Suita population. Lower ratios of LDL-chol/LDL-apo B, reflecting preponderance of small dense LDL, were observed in the above three groups. Type IIb and combined low HDL-chol were also frequent phenotypes in CAD, A-Th and ASO. The present formulae are useful for the detailed analyses of lipoprotein disorders in both qualitative as well as quantitative aspects.

Apolipoproteins B↗
PubMed1998

Density of Helicobacter pylori infection in patients with peptic ulcer perforation.

BACKGROUND: A lack of change in prevalence of severe ulcer complications requiring emergency operation has been reported, despite the common use of histamine-2 (H2)-receptor antagonists and proton pump inhibitors. This may be attributable to use of ulcerogenic drugs or Helicobacter pylori (HP) infection, or both. In this study, HP infection was evaluated semiquantitatively in patients with peptic ulcer who required surgery, and the severity of histologic change was investigated. METHODS: We reviewed a total of 113 consecutive patients (98 men and 15 women) operated on for perforation, hemorrhage, or stenosis of gastroduodenal ulcer between January 1986 and December 1995. Detection of HP was carried out by immunohistochemical staining. We graded the density of HP infection according to the number of individual HP bacteria counted in a highly magnified visual field (x 1,000 of light microscopy). The grade of HP infection was defined as follows: (0) = 0; (1+) = 1-9; (2+) = 10-29; (3+) = 30-99; (4+) > or = 100. The severity of gastritis was evaluated by histologic examination using the criteria of Rauws. RESULTS: Although the number of operations for gastroduodenal ulcer declined significantly, the rate of emergency operation for gastroduodenal ulcer increased from 60% to 90%, with the result that the frequency of operations for perforation or bleeding remained virtually constant and that for stenosis significantly decreased. HP infection was more prevalent in perforated ulcer (92%) than hemorrhagic ulcer (55%) or stenotic ulcer (45%). The grades of HP infection were 3.0 +/- 0.14 (mean +/- SEM) in perforated ulcer, 2.3 +/- 0.34 in hemorrhagic ulcer, and 2.5 +/- 0.22 in stenotic ulcer. Perforated ulcer was associated with significantly more severe HP infection and gastritis changes than hemorrhagic ulcer or stenotic ulcer. CONCLUSIONS: This study indicates that patients with perforated ulcer were infected with HP more severely than those with hemorrhagic ulcer or stenotic ulcer at the time of surgery. A close relationship was observed between the perforated ulcer and the density of HP infection determined semiquantitatively using immunohistochemical stain.

Adolescent↗
PubMed1998

Four acylated triterpenoid saponins from Albizia procera.

Four new oleanane-type triterpene glycosides, proceraosides A-D (1-4), were isolated from the seeds of Albizia procera. Their structures were established by extensive NMR experiments and chemical methods. Compounds 1-3 comprised acacic acid as the aglycon and a monoterpenic carboxylic acid linked to a monoterpene quinovoside as the acyl moiety at C-21. The common oligosaccharide moiety linked to C-28 in 1-3 was determined as alpha-l-arabino- furanosyl-(1-->4)-[beta-D-glucopyranosyl-(1-->3)]-alpha-L-rhamnopyranosy l- (1-->2)-beta-D-glucopyranosyl ester. These compounds differed in the C-3-linked sugar unit or in the configuration of C-6' of the inner monoterpene moiety in the C-21-linked acyl unit. Compound 4 was established as the 16-deoxy analogue of 1.

Carbohydrate Sequence↗
PubMed1998

Fatal cytomegalovirus interstitial pneumonia following autologous peripheral blood stem cell transplantation. Fukuoka Bone Marrow Transplantation Group.

A 52-year-old Japanese woman suffering from AML (FAB classification M4) in her first remission received an autologous peripheral blood stem cell transplant (APBSCT). She was seropositive for CMV prior to APBSCT. Her post-APBSCT course was complicated with CMV-associated disease and hemophagocytic syndrome. Finally, CMV interstitial pneumonia developed and death ensued. Even after APBSCT, there can be a short period of immune deficiency resembling that occurring following allogeneic or autologous BMT. CMV infection must be considered in the differential diagnosis in cases of unexplained fever or pneumonia following APBSCT.

Cytomegalovirus Infections↗
PubMed1998

Effect of thrombopoietin on proliferation of blasts from CD7-positive acute myelogenous leukaemia.

We investigated the effect of thrombopoietin (TPO) on the growth of leukaemic blasts from 30 acute myelogenous leukaemia (AML) patients according to the surface expression of CD7 and CD34: 10 patients were CD7 positive (CD7+), nine were CD7 negative/CD34+ (CD7-/CD34+) and the remaining 11 were CD7-/CD34-. Significant growth response of leukaemic blasts to TPO was observed in 10/10 CD7+, 5/9 CD7-/CD34+ and 2/11 CD7-/CD34- AML cases using 3H-thymidine incorporation. Synergistic stimulatory effects of TPO with stem cell factor (SCF), interleukin-3 (IL-3), granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor were observed in both TPO-responding cases (9/17) and TPO-non-responding cases (8/13). In a leukaemic blast colony assay. significant growth response to TPO was observed in 5/6 CD7+ and 4/17 CD7-AML cases examined. However, the effect of TPO on the growth of CD7+ leukaemic blasts was not so potent as that of IL-3 and SCF, both of which support the proliferation of primitive haemopoietic progenitors. Expression of c-mpl (TPO receptor) was significantly higher in CD7+ AML cases than in CD7- cases, suggesting a relationship between expression of c-mpl and proliferative response to TPO. These data indicate that CD7+ leukaemic blasts express functional TPO receptors and proliferate in response to TPO. These observations also imply that CD7 expression on AML blasts may indicate involvement of leukaemic progenitors at an early stage of multipotent haemopoietic stem cells.

Adolescent↗
PubMed1998

Clinical features of pathological grief reaction in elderly patients.

The present study investigates elderly patients suffering from a pathological grief reaction to bereavement. The subjects were nine elderly inpatients with pathological grief reactions in the Department of Psychiatry in Fukuoka University Hospital between April 1991 and March 1995. Medical records of all patients were investigated retrospectively. The results were as follows: (i) all patients were female; (ii) the deceased were all husbands; (iii) most cases were sudden death; (iv) the period to onset was variable, from immediately after death to 10 years after death; (v) a delay of grief reactions was seen in many patients; (vi) the direct causes were often something other than bereavement, such as conflict with sisters, change of residence, bone fracture and daughter's malignant illness; (vii) although there was no significant difference, the ratio of those who began to live alone after bereavement was high; (viii) the number of children were insignificant; and (ix) many patients suffered the death of a parent in childhood. The paper presents observations on the results, and discusses the psychosocial factors of elderly patients with pathological grief reactions to bereavement.

Aged↗
PubMed1998

The incidence of colorectal cancer during pregnancy in Japan: report of two cases and review of Japanese cases.

Colorectal cancer during pregnancy is very rare. We report two additional cases of rectal carcinoma. A 34-year-old woman with an obstructive adenocarcinoma of the rectal region was diagnosed at labor. A 35-year-old woman with an adenocarcinoma of the rectal region was diagnosed at 32 weeks of gestation and underwent a cesarean section and rectal resection at 35 weeks of gestation. A retrospective review of the Japanese literature was performed to identify patients who appeared to have primary colorectal cancer during pregnancy. Thirty-six patients with colon cancer (75.0%), 10 (20.8%) with rectal cancer, and two (4.2%) of unknown sites have been reported in Japanese series. The average age of the mother was 32.2 years. The calculated incidence of colorectal cancer among Japanese pregnant women was one case per 502,316 live births during the years between 1986 through 1995. Although the majority of colorectal cancers diagnosed during pregnancy are rectal carcinomas, the patients in Japan were predominantly complicated by colon cancer. The fetal risk seems small, because there were no cases of colorectal cancer metastatic to the products of conception.

Adenocarcinoma↗
PubMed1998

Antitumor effect of oxycellulose as a hemostatic during operation.

Oxycellulose, a hemostatic agent used in operation showed antitumor effect in vitro on a murine hepatic cell carcinoma (MH 134), a murine fibrosarcoma (Meth A) and a murine colon carcinoma (Colon 26). The effect was also confirmed in vivo by the survival of mice inoculated with Meth A or MH 134. Eighty milligrams per mouse of this agent, however, showed a toxicity rather than an antitumor effect. The antitumor effect of oxycellulose on Meth A did not compare with that of etoposide or mitomycin C in vivo. The antitumor effect on MH 134 was equal to that of etoposide but not mitomycin C. Oxycellulose inhibited tritium thymidine uptake into Colon 26 cells to the same extent as 5-fluorouracil and mitomycin C and it caused 51Cr-labelled Colon 26 cells but not from 5-fluorouracil or mitomycin C. Oxycellulose decreased a larger number of viable tumor cells than 5-fluorouracil or mitomycin C when the tumor cells were incubated for 24 hours at 37 degrees C. DNA histogram with MH 134 cells showed oxycellulose decreased a ratio of tumor cells in S-phase. These results suggest that the antitumor effect of oxycellulose is cytocidal and phase-specific.

Animals↗