Biomedical subjects

S Miyamoto

Publications and source records attributed to S Miyamoto.

At least 271 records · Page 15Linked to original sources

PubMed1998

[Clinical study on 6 cases of urosepsis associated with septic shock].

At Asama General Hospital, we experienced six cases of urosepsis with septic shock during a period of five years between 1989 and 1993. All six patients, whose average age was 74 years old, recovered. In four patients, the condition was caused by obstructive uropathy. The remaining two cases were caused by renal inflammatory disease, which was complicated by diabetes mellitus. One of them was renal abscess with renal papillary necrosis, and the other was emphysematous pyelonephritis. The patients, who exhibited symptoms such as gram-negative bacteremia, severe hypotension, tachycardia, decrease of urine volume and mental disturbance, were diagnosed with urosepsis with septic shock. In all cases, symptoms such as a high fever of over 39 degrees C, hypoxemia and thrombocytopenia were observed. Renal dysfunction was found in 67%, and both liver dysfunction and disseminated intravascular coagulation (DIC) were found in 50% of the cases. Since no patients suffered from adult respiratory distress syndrome, a high survival rate was apparent. Anti-shock therapy and anti-coagulation therapy were ineffective for the patients who had septic shock due to urinary tract obstruction. Urinary tract drainage was required to treat the latter patients. Nephrectomy could not be avoided in renal parenchymatous inflammatory disease. In the future, what might be essential in therapeutics against urosepsis with septic shock, particularly to avoid nephrectomy, are the treatments such as immunotherapy against endotoxins and their mediators, and hemoperfusion for the removal of endotoxins.

Aged↗

PubMed1997

Effects of long-term treatment with desipramine on microtubule proteins in rat cerebral cortex.

The molecular mechanism of the action of antidepressants beyond the receptor level has not yet been elucidated. We have investigated the effects of long-term treatment with desipramine on the phosphorylation state of microtubule-associated protein 2 (MAP2) and microtubule assembly in the rat cerebral cortex. Phosphorylation of MAP2 was detected by immunoblotting after immunoprecipitation of MAP2 in the soluble fraction. The degree of phosphorylation of serine residues of MAP2 was significantly increased after chronic administration of desipramine without changes in the total concentration of MAP2. Microtubule assembly in crude brain extracts was monitored in terms of changes in turbidity measured at 350 nm using a spectrophotometer. Chronic but not acute treatment with desipramine inhibited microtubule assembly, assayed in the presence of a phosphatase inhibitor, calyculin A, whereas the inhibition was completely nullified in the absence of calyculin A. Desipramine had no direct effect on microtubule assembly in vitro. These results raise the possibility that the changes in the degree of phosphorylation of MAP2 and microtubule assembly represent intracellular modifications involved in functional changes elicited by long-term treatment with desipramine.

Adrenergic Uptake Inhibitors↗

PubMed1997

Human recombinant tissue-factor pathway inhibitor prevents the proliferation of cultured human neonatal aortic smooth muscle cells.

Tissue-factor pathway inhibitor (TFPI) inhibits the procoagulant activity of the tissue-factor/factor VIIa complex. It was recently reported that TFPI prevented restenosis following tissue injury in a rabbit atherosclerotic model. In order to clarify the mechanism behind this successful prevention of restenosis, we investigated the direct effect of human recombinant TFPI (h-rTFPI) on the proliferation of cultured human neonatal aortic smooth muscle cells (hSMC). We found that h-rTFPI exhibits inhibitory activity toward hSMC proliferation, while h-rTFPI-C which lacks the carboxyl (C)-terminal region does not. Furthermore, we found that h-rTFPI binds to hSMCs with K(d) = 526 nM but that this binding is inhibited by the addition of the synthetic C-terminal peptide, Lys254-Met276, to h-rTFPI. Thus, the interaction of h-rTFPI with hSMCs mediated via the C-terminal region is responsible for the anti-proliferative action of h-rTFPI. On the basis of these results, we presume that the anti-proliferative effect of h-rTFPI in addition to its anticoagulant function plays a significant role in preventing restenosis following tissue injury.

Amino Acid Sequence↗

PubMed1997

Inhibition of HIV-1 protease by oxim derivatives.

In cell-free proteolytic processing using recombinant HIV-1 protease and Gag precursor polypeptide, certain simple oxim derivatives containing halogenomethylketone and phenyl moieties displayed HIV-1 protease inhibitory activity. Their Ki values ranged from 2.1 microM to 6.3 microM and they did not inhibit significantly other aspartic acid proteases. Both the halogenomethylketone moiety and the oxim structure were essential for the observed inhibition. Molecular modeling analysis suggested that these compounds are recognized by the HIV-1 protease as the P1 and P1' part of the substrate. In addition, one potent derivative showed inhibition of viral maturation in HIV-1IIIB chronically infected Molt-4 cells. These results indicate that it is possible to develop new and specific nonpeptidyl HIV protease inhibitors of low molecular weight.

Binding, Competitive↗

PubMed1997

Cloning, functional expression and tissue distribution of rabbit alpha 1d-adrenoceptor.

We have cloned a cDNA encoding rabbit alpha 1d-adrenoceptor from the rabbit liver cDNA library. The deduced amino-acid sequence of this clone encodes a protein of 576 amino acids that shows strong sequence homology to previously cloned human, rat and mouse alpha 1d-adrenoceptors. The pharmacological radioligand binding properties of this clone expressed in COS-7 cells were similar to those of rat alpha 1d-adrenoceptors. Competitive RT/PCR assays revealed wide tissue distribution of the alpha 1d-adrenoceptor mRNA in rabbit, especially abundant in vas deferens, aorta, prostate and cerebral cortex.

Amino Acid Sequence↗

PubMed1997

Primary adenocarcinoma of appendix, colonic type associated with perforating peritonitis in an elderly patient.

We report a case of colonic type adenocarcinoma of the appendix with perforating peritonitis in a 92-year-old man. The preoperative diagnosis was localized peritonitis due to acute appendicitis and emergency laparotomy was performed. A gray, hard tumor was palpated at the base of the appendix. Appendiceal cancer was suspected, and right hemicolectomy was performed. The histopathological diagnosis was moderately differentiated adenocarcinoma of the appendix. The tumor obstructed the orifice of the appendix, and this may have caused the perforation of the appendix. The patient had an uneventful postoperative course and there have been no signs of recurrence in the 2 years since the operation.

Adenocarcinoma↗

PubMed1997

Subclinical Graves' disease as a cause of subnormal TSH levels in euthyroid subjects.

In order to elucidate causes of subclinical thyrotoxicosis, we reviewed records of thyroid function tests obtained in our hospital between 1990 and 1992 showing normal thyroid hormones and subnormal TSH levels, and analyzed underlying clinical conditions of the patients. Of 186 patients with normal T4 and/or free T4 and normal T3 and/or free T3 but subnormal TSH (< 0.1 mU/l) levels in serum, 150 were under treatment with antithyroid drugs for hyperthyroid Graves' disease or with thyroid hormones for hypothyroidism. Twelve were in remission after treatment for Graves' disease, and 4 had destructive thyroiditis. Of the remaining 20 patients, 4 had autonomously functioning thyroid nodule (AFTN), 9 had euthyroid ophthalmic Graves' disease (EOG), and 7 had diffuse goiter without apparent ophthalmopathy (DG). When thyroid stimulating antibodies (TSAb) were measured in the last 3 groups of the patients, they were detected in none with AFTN but in all patients with EOG and DG. These 7 DG patients without ophthalmopathy had a clinical feature showing unstable thyroid functions, changeable to euthyroidism, overt hyperthyroidism and even hypothyroidism during follow-up. In conclusion, TSAb measurement is useful for detection of subclinical Graves' disease in euthyroid subjects with subnormal TSH levels in serum.

Adult↗

PubMed1997

Cloning, functional expression and tissue distribution of rabbit alpha1a-adrenoceptor.

A cDNA clone, which has an open reading frame of 1398 nucleotides encoding a 466-amino-acid peptide, has been isolated from rabbit liver cDNA library. Compared with the peptide sequence, it shows high homology to alpha1a adrenoceptors of human, bovine and rat. We expressed this clone in COS-7 and investigated the pharmacological properties, revealing similarity to those of human alpha1a adrenoceptors. Competitive RT/PCR has detected the mRNA in variety of rabbit tissues, especially abundantly in liver, vas deferens, brain, and aorta, but not in heart.

Amino Acid Sequence↗

PubMed1997

Surgical extirpation of the posterior hippocampal arteriovenous malformation.

BACKGROUND: Surgical extirpation of medial temporal (AVMs) arteriovenous malformations has been one of the most challenging issues in neurosurgery. Yaşargil classified mediobasal AVM into four subtypes: amygdala, anterior hippocampal, middle hippocampal, and posterior hippocampal lesions. The lesions around the trigone extending forward to the temporal horn, and medially adjacent to the midbrain, can be referred to as posterior hippocampal AVMs. The therapeutic indications and operative approaches for these lesions remain controversial. METHODS: Nine patients underwent surgical resection for AVMs of the posterior hippocampus using a laterobasal approach. RESULTS: In four patients, AVMs were located chiefly within the lateral ventricle, and the lesions were resected using a laterobasal approach through the occipitotemporal sulcus, or through a hematoma cavity within the fusiform gyrus. Clinical improvement followed the procedure in three of four patients. In the remaining five patients, the nidi were located chiefly within the ambient cistern, extending upward to the basal ganglia. Contralateral hemiparesis occurred in three patients. Two patients showed marked improvement following an initial decline in neurologic status. CONCLUSIONS: A laterobasal transventricular approach is suitable for ventricular AVMs, whereas only limited exposure can be afforded through a transventricular, transchoroidal fissure route for the AVMs within the ambient cistern. For these lesions, a conventional subtemporal approach to the tentorial incisura is preferable.

Adult↗

PubMed1997

Association of interleukin-6 in the cerebrospinal fluid during crisis of calf with ammoniated feed syndrome.

Ammoniated feed syndrome (AFS) in cattle is a neurotoxic syndrome caused by feeding specific ammoniated forage. To clarify the pathophysiology of AFS, we examined the association of interleukin-6 (IL-6) in the brain. By feeding milk either from cows fed such ammoniated forage or milk added with 4-methyl-imidazole, newborn calves showed a neurotoxic crisis of hyperexcitability, ataxia, muscle tremor, circling, roaring, epileptoid seizure, sweating and marked fever response. Although these calves had no pathological lesions in the brain, we detected a rise in IL-6 in the cerebrospinal fluid (CSF). Tumor necrosis factor-alpha (TNF-alpha) was not detected in the CSF. In the sera, IL-6 and TNF-alpha hardly changed during the experiment. Administration of recombinant human IL-6 into the lateral ventricle resulted in fever. Thus, we believe IL-6 in the CSF is related to the fever response in newborn calves with AFS.

Acute Disease↗

PubMed1997

Prevention of postmenopausal bone loss with minimal uterine bleeding using low dose continuous estrogen/progestin therapy: a 2-year prospective study.

OBJECTIVE: To re-examine the minimal effective dose of conjugated estrogen (CEE)-progestin hormone replacement on postmenopausal bone loss. DESIGN: A 2-year, prospective, open label, randomized study. SETTING: Department of Obstetrics and Gynecology of a university hospital. PARTICIPANTS: Fifty-two postmenopausal or oophorectomized women. INTERVENTION: One of the following regimens was continuously administered for 2 years: (1) CEE 0.625 mg/day, (2) CEE 0.625 mg + medroxyprogesterone (MPA) 2.5 mg/day, (3) CEE 0.31 mg + MPA 2.5 mg/day and (4) control. MEASUREMENTS: Lumbar spine and femoral BMD by dual energy X-ray absorptiometry (DXA), a monthly based incidence of bleeding, serum lipids, PTH, calcitonin. A1-p, and osteocalcin. RESULTS: Of the 52 patients enrolled in this study, 49 patients completed the 1 year of therapy and 36 completed the 2- year study. The control group showed a significant decrease in lumbar BMD over the 2 years (P < 0.05). The % changes in lumbar BMD at 2 years of CEE alone, CEE 0.625 + MPA and CEE 0.31 + MPA were 8.52% (95% confidence intervals; 4.61 approximately 12.4%), 7.4% (0.60 approximately 14.2%) and 3.20% (0.61 approximately 5.84%), respectively, and were significantly higher than pretreatment values. The incidence of bleeding was significantly lower in women taking CEE 0.31 mg + MPA. HDL cholesterol increased in women taking CEE 0.625 mg alone or with MPA. No significant changes in lipid profiles were seen in the control or in the group of women taking CEE 0.31 mg + MPA. CONCLUSIONS: Continuous hormone replacement therapy (HRT) using 0.31 mg of CEE and 2.5 mg of MPA is effective in increasing lumbar BMD in postmenopausal or oophorectomized women and can be an appropriate option for women with a normal lipid profile or those women wishing to eliminate unscheduled bleeding.

Bone Density↗

PubMed1997

Estrogen receptor gene polymorphism and bone mineral density at the lumbar spine of pre- and postmenopausal women.

In order to analyze the role of the estrogen receptor (ER) gene allelic polymorphisms on bone mineral density (BMD), 173 pre- and postmenopausal women were divided into four groups according to their menstrual status (group A: premenopausal women; group B: late premenopausal women; group C: postmenopausal women who had menopause for 5 years or less; and group D: postmenopausal women who had menopause for more than 5 years), and the relationship between ER gene polymorphism and lumbar spine BMD, the percent annual change in BMD and biochemical markers were studied. The restriction fragment length polymorphism (RFLPs) were represented as Xx (XbaI) and Pp (PvuII), with upper case and lower case letters signifying the absence or presence of restriction sites, respectively. In group A, the Xx genotype had significantly higher BMD (p < 0.01) than the xx genotype, but the difference was lost in groups B, C, and D. Because the percent annual change in BMD of group A was 0.052% and was not statistically different among genotypes, it is suggested that RFLP by Xba I is closely linked with peak bone mass that was attained during the subject's late thirties. In group B, serum N-region osteocalcin (N-OC) levels and the percent annual change in BMD showed a significantly larger increase than that of group A, indicating postmenopausal bone loss had commenced. Because the N-OC level of the Xx genotype was significantly higher than that of the xx genotype (p < 0.05), and the percent annual change in BMD of the Xx genotype showed a tendency to increase (p = 0.072), it is suggested that the high BMD of the Xx genotype is rapidly lost during menopausal transition. There were no significant relationships between RFLP and BMD in groups C and D, and between RFLP and BMD in groups C and D, and between RFLP by PvuII and BMD. The present study suggests that the Xx genotype is involved in accretion of BMD during young adulthood, but the effect was lost during menstrual transition.

Adult↗

PubMed1997

Value of combined technetium-99m hydroxy methylene diphosphonate and thallium-201 imaging in detecting bone metastases from thyroid carcinoma.

Detectability of bone metastases from differentiated thyroid carcinoma by technetium-99m hydroxymethylene diphosphonate ([99m]Tc-HMDP) bone scan is considered to be poor. Thallium-201 (201Tl) is also widely used for detecting metastatic lesions. Our present study was aimed at the evaluation of the combined use of (99m)Tc-HMDP and 201Tl imaging in successful detection of bone metastases from differentiated thyroid carcinoma. Twenty-seven thyroidectomized thyroid cancer patients (19 females, 8 males; 12 papillary type, 15 follicular type) with 77 bone lesions were included in this retrospective study. All of these patients received ablative doses of radioiodine. Thyroidal origin of the lesions was proved by positive iodine-131 (131I) uptake. In 131I-negative lesions, histological proof or absence of tumor markers other than thyroglobulin was considered when computed tomography (CT) and/or magnetic resonance imaging (MRI) suggested metastatic nature of the lesions. Of the 77 lesions, 58 (75.3%) were positive and 19 were negative in the (99m)Tc-HMDP bone scintigraphy, whereas 53 lesions (68.9%) could be detected by 201Tl scintigraphy. However, within the 19 (99m)Tc-HMDP-negative lesions, 14 showed abnormal accumulation of 201Tl, and within the 24 201Tl negative lesions, 19 were positive in (99m)Tc-HMDP scan. This resulted in a combined sensitivity of 93.5%. Our present study concludes that combined (99m)Tc-HMDP and 201Tl imaging is a sensitive and effective method for detecting bone metastases from thyroid carcinoma.

Adenocarcinoma, Follicular↗

PubMed1997

Discovery of a novel thrombopoietin mimic agonist peptide.

A random phage peptide library was constructed for the filamentous bacteriophage fuse5. The library was made by inserting a degenerate oligonucleotide which encodes 15 variable amino acids into the NH2-terminal region of the phage gene III protein. This library, containing 1x10(9) different phages, was screened with a human immunoglobulin fusion protein containing the extracellular region of human thrombopoietin receptor. Several phages were isolated following four cycles of enrichment and amplification. These phages specifically bound to the fusion protein. One phage peptide acted as an agonist of the thrombopoietin receptor, since it stimulated the proliferation of thrombopoietin-dependent cells and the differentiation of mouse bone marrow cells to megakaryocytes. The amino acid sequence of this peptide is not present in the primary amino acid sequence of thrombopoietin. This discovery may lead to the design of a small-molecular mimic of thrombopoietin.

Amino Acid Sequence↗

PubMed1997

Relationship between pentosidine levels in serum and urine and activity in rheumatoid arthritis.

Pentosidine is one of the advanced glycation end-products and is formed by glycosylation and oxidation. The aim of this study is to investigate the relationship between serum and urinary pentosidine levels and the activity of rheumatoid arthritis (RA). Using HPLC with column switching, we measured pentosidine in serum and urine from 77 patients with RA and 62 normal control subjects. The clinical features, blood biochemistry and activity of inflammation were examined in RA patients. Serum and urinary pentosidine in RA were significantly higher than in controls. Pentosidine significantly correlated with age, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), rheumatoid factor, joint score and Lansbury Index in RA. The levels of pentosidine were higher in patients with active RA than in those with inactive RA. Serum and urine levels of pentosidine correlated with the activity of RA, and serum and urinary pentosidine may be a significant and novel marker for evaluating the disease status and the activity of RA.

Adult↗

PubMed1997

Increased plasma concentrations of adrenomedullin correlate with relaxation of vascular tone in patients with septic shock.

OBJECTIVE: To investigate plasma concentrations of adrenomedullin in patients with septic shock and the potential association of these concentrations with relaxation of vascular tone. DESIGN: Prospective, case series. SETTING: Department of Emergency and Critical Care Medicine, Nara Medical University. PATIENTS: Twelve patients who fulfilled the clinical criteria for severe sepsis or septic shock (as defined by the Members of the American College of Chest Physicians/Society of Critical Care Medicine Consensus Conference Committee) and 13 healthy volunteers. INTERVENTIONS: Arterial blood samples were obtained via a 20-gauge cannula inserted into each patient's radial artery. MEASUREMENTS AND MAIN RESULTS: After extraction and purification, plasma adrenomedullin was measured by radioimmunoassay. Systemic vascular resistance index, pulmonary vascular resistance, cardiac index, and stroke volume index were determined with a thermodilution catheter. The mean plasma concentration of adrenomedullin was markedly higher in patients than in controls (226.1 +/- 66.4 [SEM] vs. 5.05 +/- 0.21 fmol/mL, p < .01). Moreover, these concentrations correlated significantly with cardiac index, stroke volume index, and heart rate values, and correlated significantly with decreases in diastolic blood pressure, systemic vascular resistance index, and pulmonary vascular resistance index values. CONCLUSIONS: Enhanced production of adrenomedullin in patients with septic shock may contribute to reduced vascular tone, hypotension, or both. More data are needed to clarify the role of adrenomedullin in the regulation of vascular tone in this patient population.

Adrenomedullin↗

PubMed1997

A case of primary malignant fibrous histiocytoma of the heart with a left-to-right atrial shunt.

A previously healthy 64-year-old woman attended our hospital with chest pain, facial edema, and general fatigue. A chest radiograph revealed cardiomegaly, small bilateral pleural effusions, and hilar congestion--findings that improved after early therapy with furosemide and methyldigoxin. A chest radiograph recorded 7 years earlier had revealed no dilation of cardiac shadow. There were no findings suggesting atrial septal defect (ASD) or valvular heart disease. Echocardiography revealed a tumor-like mass adhering to the posterior wall of the left atrium. Color-flow Doppler echocardiography revealed a left-to-right shunt at the atrial level. The Qp/Qs ratio as measured by cardiac catheterization was 2.0. Coronary angiography revealed abnormal dilated arteries from the atrioventricular nodal branch and several feeding arteries from the left circumflex branch. We hypothesized that the left-to-right shunt could be due to the tumor, which extended to the rim of the patent foramen ovale, or to the very small, previously unrecognized, ASD. This patient died 6 months after her first admission and an autopsy was performed. Light microscopic examination of the tumor revealed spindle-shaped fibroblast-like cells arranged in a storiform or fascicular pattern. The immunohistochemical findings were consistent with malignant fibrous histiocytoma (MFH). In the literature, left-to-right shunt at the atrial level has not been reported in patients with cardiac MFH.

Echocardiography↗

PubMed1997

Assessment of thyroid growth stimulating activity of immunoglobulins from patients with autoimmune thyroid disease by cytokinesis arrest assay.

OBJECTIVE: To develop a novel bioassay for the assessment of thyroid cell growth stimulating activity using cytochalasin B (CB) and to test immunoglobulins (IgGs) from patients with autoimmune thyroid diseases. DESIGN: The assay is based on the principle that growing cells during incubation with CB show an increased number of nuclei in a cell (N/C index), since CB, at appropriate concentrations, is known to inhibit cytoplasmic cleavage without affecting nuclear mitosis. The N/C index represents potential DNA production while cells are incubated with CB. METHODS: FRTL-5 thyroid cells were incubated with various thyroid stimulators in TSH-free medium containing 2 mg/J CB for 3 days. After the incubation, the cells were harvested in trypsin/EDTA to obtain single cell suspension, fixed, dropped onto a glass slide, stained and observed under a microscope to determine the N/C index. RESULTS: Bovine TSH at 10(-3)-1.0 U/I, forskolin at 1x10(-7)-10(-5) mol/l, cholera toxin at 10x10(-5)-10(-3) mg/l, or (Bu)2cAMP at 1 x 10(-5)-10(-3) mol/l increased the N/C index up to approximately 2.0 in a dose-dependent manner. IgGs not only from 27 patients with untreated goitrous Graves' disease but also from 14 patients with goitrous Hashimoto's thyroiditis elicited an increase in the N/C index, which exceeded the mean + 2 S.D. of the values for 17 normal subjects (mean +/- S.D., 1.063 +/- 0.014). Four patients with primary myxedema displayed a normal N/C index. In Graves' disease, the N/C index did not correlate significantly with thyroid stimulating antibodies (TSAb) activities but did correlate significantly with estimated goiter size (P < 0.05). IgGs containing blocking-type TSH-receptor antibodies inhibited the TSH- or Graves IgG-stimulated increase in N/C index almost completely, but did not influence the stimulatory effect of IgG from two patients with Hashimoto's thyroiditis. CONCLUSIONS: We have developed a sensitive and simple assay for thyroid growth stimulating activity by using CB, and found that all tested patients with goitrous Graves' disease and goitrous Hashimoto's thyroiditis have thyroid growth stimulating immunoglobulins whose activity does not correlate with TSAb.

Animals↗