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H Yoshida

Publications and source records attributed to H Yoshida.

At least 541 records · Page 30Linked to original sources
PubMed1999

Heme oxygenase-1 expression in oral squamous cell carcinoma as involved in lymph node metastasis.

Thirty-eight oral squamous cell carcinomas (SCCs) were semi-quantitatively analyzed by immunohistochemical staining, and the relation between heme oxygenase-1 (HO-1) expression and the clinical status were correlated. High immunostaining of HO-1 was detected in lymph node metastasis negative groups (P = 0.0018) and in well-differentiated SCCs (P = 0.0016). There were no significant correlations between heme oxygenase-1 expression and other factors, such as size of the tumor, staging, age and sex. These findings further support the proposition that high heme oxygenase-1 expression in oral SCCs can be useful in identifying patients at low risk of lymph node metastasis.

Adult↗
PubMed1999

The effect of a thymidine phosphorylase inhibitor on angiogenesis and apoptosis in tumors.

Thymidine phosphorylase (TP) is an enzyme involved in the reversible conversion of thymidine to thymine and is identical to an angiogenic factor, platelet-derived endothelial cell growth factor. TP is expressed at higher levels in a wide variety of solid tumors than in the adjacent nonneoplastic tissues. Patients with TP-positive colon and esophageal tumors have a poorer prognosis than those with TP-negative tumors. We have recently synthesized a new TP inhibitor (TPI), 5-chloro-6-[1-(2-iminopyrrolidinyl) methyl] uracil hydrochloride. We investigated the effect of TPI on angiogenesis in KB cells transfected with platelet-derived endothelial cell growth factor cDNA, KB/TP, and a mock transfectant, KB/CV, using the mouse dorsal air sac assay model. We found that KB/TP cells had a higher angiogenic ability than KB/CV cells and that TPI completely suppressed angiogenesis by KB/TP. Furthermore, at a dose of 50 mg/kg/day, TPI considerably decreased the growth rate of KB/TP cells xenografted into nude mice. Microvessel density in KB/TP tumors was higher than that in KB/CV tumors, and TPI did not significantly change the density in either of the tumors. The apoptotic index in KB/TP tumors was significantly lower than that in KB/CV tumors, and TPI significantly increased the apoptotic index in KB/TP tumors but not in KB/CV tumors. These findings, taken together with previous reports, suggest that the expression of TP plays an important role in tumor growth and that TPI suppresses tumor growth by increasing the proportion of apoptotic cells and probably inhibiting angiogenesis.

Animals↗
PubMed1999

Interhemispheric asymmetry of event-related fields concerned with logical processing during auditory oddball stimulation.

This study investigated the cortex during logical processing of auditory information using a 122-channel dc-SQUID gradiometer. The experimental task was designed to require a simple logical decision prior to counting rare paired tones, which consisted of two different pitches and were presented to separate ears. Among six subjects, left and right predominant dipolar activity was observed in three subjects each. When the dipolar sources were superimposed on MR images, the inferior region of the supramarginal gyrus showed activation, suggesting that logical processing occurred in the association cortex but not in the auditory cortex. We propose a modified cognitive sequence model in which auditory information processed in Heschl's gyri is transmitted to the supramarginal gyrus to commence automatic detection processing.

Acoustic Stimulation↗
PubMed1999

Intraperitoneal administration of anti-c-fms monoclonal antibody prevents initial events of atherogenesis but does not reduce the size of advanced lesions in apolipoprotein E-deficient mice.

BACKGROUND: Atherosclerosis results from complex inflammatory-fibroproliferative responses. To elucidate the central role of macrophage and macrophage-colony stimulating factor (M-CSF) during atherogenesis, we used a new strategy to administer to adult apolipoprotein E (apoE)-deficient mice a monoclonal antibody (AFS98) raised against c-fms, the receptor of M-CSF. METHODS AND RESULTS: When 6-week-old apoE-deficient mice were fed a high-fat diet and injected with 2 mg of AFS98 intraperitoneally on alternate days for 6 weeks, accumulation of macrophage-derived foam cells in the aortic root was suppressed by 70% compared with that in controls. This preventive effect was associated with neither remarkable decrease of the number of circulating monocytes nor systemic growth retardation. In contrast, when apoE-deficient mice that had been fed a high-fat diet from 6 weeks of age were given AFS98 from 12 to 18 weeks of age, a minimal protective effect on lesion size was observed. CONCLUSIONS: These results suggest that (1) macrophage and M-CSF/c-fms play an essential role in the arterial wall during development of the fatty streak lesion and (2) blockade of the M-CSF/c-fms pathway could act as protection from at least early atherogenesis but could have a less preventive effect on maintenance of the advanced lesions.

Animals↗
PubMed1999

Apaf-1 and caspase-9 in p53-dependent apoptosis and tumor inhibition.

The ability of p53 to promote apoptosis in response to mitogenic oncogenes appears to be critical for its tumor suppressor function. Caspase-9 and its cofactor Apaf-1 were found to be essential downstream components of p53 in Myc-induced apoptosis. Like p53 null cells, mouse embryo fibroblast cells deficient in Apaf-1 and caspase-9, and expressing c-Myc, were resistant to apoptotic stimuli that mimic conditions in developing tumors. Inactivation of Apaf-1 or caspase-9 substituted for p53 loss in promoting the oncogenic transformation of Myc-expressing cells. These results imply a role for Apaf-1 and caspase-9 in controlling tumor development.

Animals↗
PubMed1999

Correlation of antiangiogenic and antitumor efficacy of N-biphenyl sulfonyl-phenylalanine hydroxiamic acid (BPHA), an orally-active, selective matrix metalloproteinase inhibitor.

The antiangiogenic activity and antitumor efficacy of a newly developed matrix metalloproteinase (MMP) inhibitor were examined. N-biphenyl sulfonyl-phenylalanine hydroxiamic acid (BPHA) potently inhibits MMP-2, -9, and -14, but not MMP-1, -3, or -7. In contrast, (-)BPHA, an enantiomer of BPHA, was inactive against all MMPs tested. Daily oral administration of 200 mg/kg BPHA, but not (-)BPHA in mice resulted in potent inhibition of tumor-induced angiogenesis, primary tumor growth, and liver metastasis. The growth inhibition activity of BPHA was 48% and 45% in a B16-BL6 melanoma and F2 hemangio-endothelioma model, respectively. BPHA also showed 42% inhibition of the liver metastasis of C-1H human colon carcinoma cells. These results indicate that selective MMP inhibition is correlated with antiangiogenic and antitumor efficacy and that the selective MMP inhibitor BPHA has therapeutic potential.

Animals↗
PubMed1999

Genetic evidence for functional redundancy of Platelet/Endothelial cell adhesion molecule-1 (PECAM-1): CD31-deficient mice reveal PECAM-1-dependent and PECAM-1-independent functions.

Platelet/endothelial cell adhesion molecule-1 (PECAM-1; CD31), a member of the Ig superfamily, is expressed strongly at endothelial cell-cell junctions, on platelets, and on most leukocytes. CD31 has been postulated to play a role in vasculogenesis and angiogenesis, and has been implicated as a key mediator of the transendothelial migration of leukocytes. To further define the physiologic role of CD31, we used targeted gene disruption of the CD31 gene in embryonic stem cells to generate CD31-deficient mice. CD31-deficient mice (CD31KO) are viable and born at the expected Mendelian frequency, remain healthy, and exhibit no obvious vascular developmental defects. In response to inflammatory challenge, polymorphonuclear leukocytes of CD31KO mice are arrested between the vascular endothelium and the basement membrane of inflammatory site mesenteric microvessels, confirming a role for CD31 in the migration of neutrophils through the subendothelial extracellular matrix. Normal numbers of leukocytes are recovered from inflammatory sites in CD31KO mice, however, suggesting that the defect in leukocyte migration across basal lamina observed in the absence of CD31 may be compensated for by the use of other adhesion molecules, or possibly an increased rate of migration. Homing of T lymphocytes in vivo is normal, and CD31KO mice are able to mount a cutaneous hypersensitivity response normally. In addition, CD31-mediated homophilic adhesion does not appear to play a role in platelet aggregation in vitro. This study provides genetic evidence that CD31 is involved in transbasement membrane migration, but does not play an obligatory role in either vascular development or leukocyte migration.

Animals↗
PubMed1999

OPGL is a key regulator of osteoclastogenesis, lymphocyte development and lymph-node organogenesis.

The tumour-necrosis-factor-family molecule osteoprotegerin ligand (OPGL; also known as TRANCE, RANKL and ODF) has been identified as a potential osteoclast differentiation factor and regulator of interactions between T cells and dendritic cells in vitro. Mice with a disrupted opgl gene show severe osteopetrosis and a defect in tooth eruption, and completely lack osteoclasts as a result of an inability of osteoblasts to support osteoclastogenesis. Although dendritic cells appear normal, opgl-deficient mice exhibit defects in early differentiation of T and B lymphocytes. Surprisingly, opgl-deficient mice lack all lymph nodes but have normal splenic structure and Peyer's patches. Thus OPGL is a new regulator of lymph-node organogenesis and lymphocyte development and is an essential osteoclast differentiation factor in vivo.

Animals↗
PubMed1999

Effects of ketamine and pentobarbital on noradrenaline release from the medial prefrontal cortex in rats.

PURPOSE: To determine the effects of ketamine and pentobarbital on noradrenaline release from the medial prefrontal cortex. METHODS: In 14 male Wistar rats, a microdialysis probe with a 2 mm long semipermeable membrane was implanted in the medial prefrontal cortex. The dialysis probe was perfused at a rate of 1 microl x min(-1) with an artificial cerebrospinal fluid solution. The rats were randomly allocated to two groups: ketamine (group K, n=7) and pentobarbital (group P, n=7). Each rat was subsequently given 0 (saline), 1, 10 and 100 mg x kg(-1) ketamine i.p. in group K, and 0 (saline), 0.5, 5 and 50 mg x kg(-1) pentobarbital i.p. in group P. Sixty minutes elapsed between administration. Noradrenaline concentration was measured by HPLC with an electrochemical detector at 20 min intervals. (detection limit: 250 fg x 20 microl(-1), coefficient variation of the assay: 4.9%). The data in the 20-40 min after each dose of ketamine or pentobarbital i.p. were used for the statistical analysis. RESULTS: Noradrenaline release after 100 mg x kg(-1) ketamine increased by 7.7 +/- 2.0 (SEM) pg x collection(-1) compared with 2.7 +/- 0.7, 3.3 +/- 1.0 and 4.2 +/- 0.8 pg x collection(-1) after saline, 1 and 10 mg x kg(-1) ketamine, respectively (P < 0.05). Noradrenaline release did not change after pentobarbital. CONCLUSION: This study suggests the ketamine and pentobarbital have different effects on noradrenergic neurons in the medial prefrontal cortex. The stimulating effect of ketamine on noradrenaline release from the cortex might contribute to unique clinical features of ketamine anesthesia.

Adjuvants, Anesthesia↗
PubMed1999

Covering the head and face maintains intraoperative core temperature.

PURPOSE: To determine the effect of covering the patient's head and face on the prevention of intraoperative hypothermia (<35.5 degrees C). METHODS: This randomized, prospective trial included 44 adults undergoing elective abdominal surgery. After the induction of anesthesia with thiopental, in 44 patients their extremities and trunk were covered with towels and sheets. In addition, 22 patients (covered group) had their face and head fully covered. Anesthesia was maintained with N2O 50-66% (2-3 L x min(-1)) and isoflurane (<IMAC) in oxygen combined with thoracic epidural anesthesia. Core temperature was measured at the tympanic membrane continuously and was recorded at 15 min intervals from the induction of anesthesia. Heat and moisture exchangers were used in their anesthetic circuit. Ambient temperature was maintained near 25 degrees C. RESULTS: Neither group demonstrated intraoperative hypothermia. However, tympanic membrane temperature at 75, 90, 105 min in the covered group were higher than those of control group (36.7+/-0.4 degrees C vs. 36.5+/-0.4 degrees C, 36.8+/-0.5 degrees C vs. 36.4+/-0.5 degrees C, 36.8+/-0.5 degrees C vs. 36.4+/-0.5 degrees C, respectively, P<0.05). CONCLUSION: Covering the patient's head and face maintains intraoperative core temperature.

Adult↗
PubMed1999

Post-parturition infectious endocarditis in a patient with a normal mitral valve.

A 29-year-old woman with no history of heart disease was admitted for the treatment of congestive heart failure. Six months earlier, she had given birth, then 20 days later developed a fever and cardiac failure ensued. An echocardiogram demonstrated severe mitral valve regurgitation. Her blood cultures were positive, and we made a diagnosis of mitral valve regurgitation due to infectious endocarditis. Despite treatment for congestive heart failure and antibiotic therapy, resulting in negative blood cultures, her congestive heart failure did not improve, and vegetation on the mitral valve was observed by echocardiography. We successfully removed the infected tissue with mitral valve plasty.

Adult↗
PubMed1999

Effects of sedatives on noradrenaline release from the medial prefrontal cortex in rats.

RATIONALE: N-Methyl-d-aspartate (NMDA) receptor antagonism and GABA(A) receptor activation are believed to be critical targets for general anesthetic action. However, as NMDA antagonism of intravenous anesthetic agents causes post-anesthetic emergence reactions such as hallucination and agitation, while the GABA(A)-mimetic intravenous anesthetic agents do not, these two classes of intravenous anesthetic agents produce differential clinical profiles. OBJECTIVE: We have investigated the differential effects of the GABA(A) agonists propofol and midazolam and the NMDA antagonist ketamine on noradrenaline release from the medial prefrontal cortex of the rat using microdialysis, as noradrenergic neurons have a role to play in anesthesia and are known to be important in the control of sleep, attention and learning. METHODS: Twenty-one male Wistar rats (200-270 g) were randomly allocated into three groups: ketamine 100 mg x kg(-1) (n = 6), propofol 60 mg x kg(-1) (n = 8) and midazolam 5 mg x kg(-1) (n = 7) IP. A unilateral guide cannula was implanted stereotaxically into the medial prefrontal cortex under pentobarbital anesthesia (50 mg x kg(-1) IP). Forty-eight hours later, a dialysis probe was inserted through the guide cannula, and perfused with an artificial cerebrospinal fluid solution containing 1 mM pargyline. Following an equilibration period, samples of dialysate were collected every 10 min. Noradrenaline content was measured by high-performance liquid chromatography using an electrochemical detector. RESULTS: Anesthesia times, defined as the duration between the loss of righting reflex and recovery, were 24.7+/-5.6 (SEM), 20.5+/-1.9 and 25.2+/-1.5 min for propofol, midazolam and ketamine, respectively (no significant between-group differences). Both GABA(A )agonists, propofol and midazolam, significantly decreased noradrenaline release (75% and 71% of basal release, respectively). The NMDA antagonist ketamine markedly increased noradrenaline release (413% of basal). CONCLUSION: These data suggest that different clinical profiles observed with these two classes of sedatives may result from changes in noradrenaline release from the medial prefrontal cortex.

Animals↗
PubMed1999

Ethnic difference in contribution of Sp1 site variation of COLIA1 gene in genetic predisposition to osteoporosis.

Osteoporosis, a condition characterized by low bone mineral density (BMD) leading to bone fragility [1], is a major public health concern in Japan as well as in other countries. Although genetic predisposition seems to be a factor in the pathogenesis of osteoporosis [2-4], the precise cohort of genes that may be involved is not well defined. The COLIA1 and COLIA2 genes encode polypeptide constituents of collagen type Ialpha1 and Ialpha2, respectively. Both are important candidates as genetic regulators of BMD, since mutations in either gene result in osteogenesis imperfecta, a disorder characterized by severe osteoporosis [5]. Some patients with adult osteoporosis also carry mutations in COLIA1 or COLIA2 genes [6].http://link.springer-ny. com/link/service/journals/00223/bibs/65n5p352.html</++ +hea

Aged↗
PubMed1999

Inhibitory effects of FK506 on the development of experimental allergic/immune-mediated blepharoconjunctivitis in Lewis rats by systemic but not by topical administration.

BACKGROUND: FK506 has been used for treatment of cell-mediated immune disorders such as graft rejection in transplantation or Behçet disease. To evaluate the effectiveness of FK506 in another ocular disease model, we injected FK506 in rats with experimental allergic/immune-mediated blepharo conjunctivitis (EAC) the induction mechanism of which depends on cell-mediated immunity. METHODS: Lewis rats were immunized with ovalbumin (OVA) in emulsion of complete Freund's adjuvant (CFA). We injected 2 (n = 6), 20 (n = 6) or 200 (n = 5) microg of FK506 intramuscularly daily from the day of immunization (day 0) to day 6. Control rats were not treated with FK506 (n = 4). In addition, we injected 200 microg of FK506 from day 7 to day 13 (n = 12) to compare the timing of FK506 administration (day 0 to day 6, n = 12; control, n = 12). Twenty-one days after immunization, all rats were challenged with OVA by eye drops, and 24 h later they were killed after clinical evaluation and their eyes, blood and draining lymph nodes were harvested for histology, antibody titers and proliferation assay or flow cytometric analysis. In another set of experiments, rats that had received OVA-primed lymph node cells did (n = 9) or did not (n = 9) receive additional FK506 by injection daily for 4 days. Four days after transfer, these rats were challenged with OVA and evaluated as mentioned. To investigate possible suppression of disease by topical administration of FK506, both actively immunized and passively immunized rats received OVA together with 0.3% (weight/volume) of FK506 (n = 16) or vehicle (n = 10) by eye drops and 24 h after challenge, rats were evaluated as mentioned. RESULTS: Development of disease, induced by either active or passive immunization, was inhibited in the group treated with 200 microg of FK506, regardless of timing of administration. Cellular proliferative responses to OVA were inhibited only in this group. Flow cytometry demonstrated a decrease of about 20% in the proportion of all cells made up by CD4-positive T cells. Topical administration of FK506 inhibited the development of EAC, though not significantly. CONCLUSIONS: Systemic treatment with 200 microg of FK506 either in the induction or the effector phase inhibits the development of EAC in Lewis rats. Topical administration is not so effective as systemic administration.

Adoptive Transfer↗
PubMed1999

Visualization of acidic compartments in cultured osteoclasts by use of an acidotrophic amine as a marker for low pH.

Using the acidotrophic amine 3-(2,4-dinitroanillino)-3'-amino-N-methyldipropylamine (DAMP) as a marker for low pH and immunofluorescence cytochemistry, we examined acidic compartments of osteoclasts cultured on cover glasses or bone slices, where they could resorb the bone surface, forming resorptive lacunae. DAMP-positive structures were seen as vesicular and tubular forms in the cytoplasm, indicating lysosomes and endosomes. Not only the osteoclastic cytoplasm but also the extracellular area around the ruffled border and resorptive lacunae were stained with DAMP, suggesting acidic regions. Immunofluorescence was localized predominantly on the substratum side of actively resorbing osteoclasts, whereas an evenly distributed staining pattern was seen in the nonactive cell. The most intensive reaction was seen at the advancing front of resorptive lacunae within the actively resorbing osteoclasts. The distribution pattern of DAMP seemed to be correlated with the osteoclastic activity, since osteoclasts exhibit alternating resorption and migration phases during the bone-remodeling cycle. In this culture system, the resorptive lacunae were left behind after the osteoclasts had completed resorption and migrated along the bone surface. These exposed resorptive lacunae were also stained with DAMP, which were presumably kept at an acidic pH. The effect of treatment with monensin, chloroquine, ammonium chloride, or nigericin was varied in terms of the immunoreactivity for DAMP, but not complete abolition of the staining was obtained. Weak bases such as chloroquine or ammonium chloride inhibited both intra- and extracellular immunoreactivity. Immunoreactivity for the vacuolar type of proton ATPase (V-ATPase) was demonstrable in the cytoplasm of the osteoclasts but was weakened by the addition of bafilomycin. Immunofluorescence of the resorptive lacunae was still retained even after the treatment with bafilomycin and acetazolamide. Besides, both bafilomycin and acetazolamide reversibly inhibited cellular acidity as judged by DAMP immunocytochemistry, which agrees with the fact that ostoeclastic acidification results from the action of vacuolar proton-pump ATPase coupled with carbonic anhydrase.

Acetazolamide↗
PubMed1999

Polyarthritis nodosa with mesenteric aneurysms demonstrated by angiography: report of a case and successful treatment of the patient with prednisolone and cyclophosphamide.

Polyarteritis nodosa is a necrotizing angitis that predominantly affects small and medium-sized arteries. The prognosis of untreated polyarteritis nodosa is very poor. Since symptoms are diverse and no serologic test is specific for polyarteritis nodosa, the diagnosis is difficult and often delayed. We describe a patient with polyarteritis nodosa who had gastrointestinal involvement with multiple aneurysms of the inferior mesenteric artery; only abdominal angiography provided a conclusive diagnosis. Alleviation of symptoms and regression of aneurysms were observed after combination therapy of an immunosuppressive agent, cyclophosphamide, and prednisolone. We emphasize the importance of early diagnosis by angiography and aggressive therapy in patients in whom physical signs indicating definite polyarteritis nodosa are not present.

Aneurysm↗
PubMed1999

The relationship between facet joint osteoarthritis and disc degeneration of the lumbar spine: an MRI study.

The role of MRI in assessing facet joint osteoarthritis is unclear. By developing a grading system for severity of facet joint osteoarthritis on MRI, the relationship between disc degeneration and facet joint osteoarthritis was determined. The accuracy of MRI in assessing facet joint osteoarthritis against CT was 94%. Under 40 years of age, the degree of disc degeneration varied among individuals. Over the age of 60, most of the discs were markedly degenerated. Under 40 years of age osteoarthritic changes in facet joints were minimal. Over the age of 60, variable degrees of facet joint osteoarthritis were observed but some facets did not show osteoarthritis. No facet joint osteoarthritis was found in the absence of disc degeneration and most facet joint osteoarthritis appeared at the intervertebral levels with advanced disc degeneration. Disc degeneration is more closely associated with aging than with facet joint osteoarthritis. The present study supports the hypothesis that "disc degeneration precedes facet joint osteoarthritis", and also supports the concept that it may take 20 or more years to develop facet joint osteoarthritis following the onset of disc degeneration.

Adult↗