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Biomedical subjects

S Yamano

Publications and source records attributed to S Yamano.

At least 73 records · Page 4Linked to original sources
PubMed1998

[Carotid artery atherosclerosis in patients with myocardial infarction].

This study investigated carotid artery atherosclerosis in patients with myocardial infarction. One hundred and two patients with acute myocardial infarction [Group MI: male 86, female 16, mean 62 (range 43-79) years] and 55 normal subjects matched for age and sex with negative responses to exercise electrocardiogram testing (control group: Group C) were included. Patients in Group MI were divided into 3 subgroups according to coronary angiographic findings as follows: 57 patients with one-vessel disease (Group I: mean 59 years), 34 with 2-vessel disease (Group II: mean 64 years), and 11 with 3-vessel disease (Group III: mean 64 years). Intima-media complex thickness (IMT) of the bilateral common carotid arteries (15 mm proximal to the bifurcation) and the internal carotid arteries (15 mm distal to the bifurcation) were measured by high-resolution B-mode ultrasonography, and the sum of maximum IMT of the bilateral carotid arteries (sigma IMT) were calculated. sigma IMT was significantly greater in Group MI (2.5 +/- 0.5 mm) than in Group C (1.8 +/- 0.3 mm), sigma IMT was 2.5 +/- 0.5 in Group I, 2.6 +/- 0.5 in Group II, and 2.7 +/- 0.4 mm in Group III. There was a significant positive correlation between sigma IMT and the number of involved vessels (tau = 0.45, p < 0.01). The percentage of patients with carotid artery atherosclerosis was 2% in Group C, 63% in Group MI, 54% in Group I, 68% in Group II, and 82% in Group III (p < 0.001). This study suggests that carotid artery atherosclerosis in patients with myocardial infarction is frequently complicated and severe, and more frequently complicated in patients with severe coronary artery disease.

Adult↗
PubMed1997

Purification, characterization and partial primary structure of morphine 6-dehydrogenase from rabbit liver cytosol.

Morphinone, a toxic metabolite, was formed from morphine by NAD(P)-dependent morphine 6-dehydrogenase(s) in both the cytosol and microsomal fractions of the rabbit liver at pH 7.4. The enzyme activity in the cytosol fraction was about twice that in the microsomal fraction and NAD served as the preferred cofactor in both fractions. The enzyme in the cytosol fraction was purified to a homogeneous protein by the use of various chromatographic techniques. The enzyme is a monomeric protein with a molecular weight of 36,000 and an isoelectric point of 6.4. The enzyme had a dual cofactor specificity but NAD was more efficiently utilized than NADP. With NAD, the enzyme showed an optimal pH of 9.4, and the Km and Vmax values toward morphine were 0.72 mM and 0.59 unit/mg protein, respectively. The enzyme also exhibited a significant activity for morphine analogs having an unsaturated bond at C-7,8 (codeine, ethylmorphine, and normorphine), alicyclic alcohols (3-hydroxyhexobarbital, 1-indanol, and cyclohexene-2-ol) and benzenedihydrodiol. In the reverse reaction, the enzyme exhibited highly restricted specificity for o-quinones. Sulfhydryl re-agents and quercetin inhibited the enzyme but pyrazole, barbital, and indomethacin had little effect on the enzyme activity. Androstanes, lithocholic acid, and estradiol potently inhibited the enzyme in a competitive manner toward morphine binding. The partial amino acid sequence of the random peptides obtained by the proteolytic digestion of the enzyme, which comprised about 40% of the whole protein, revealed a significant homology to the corresponding regions in the members of the aldo-keto reductase family. These results therefore indicate that the present enzyme is a new and unique member of the aldo-keto reductase family.

Alcohol Oxidoreductases↗
PubMed1997

Avoidance of oocyte retrieval on the weekend through the use of scheduled ovarian hyperstimulation for in vitro fertilization and embryo transfer.

OBJECTIVE: To avoid oocyte retrieval for IVF-ET during the weekend, the scheduled method of ovarian hyperstimulation, in which oocyte retrieval is planned in advance for Monday through Wednesday, was evaluated. DESIGN: A retrospective study. SETTING: The IVF-ET unit of the Department of Obstetrics and Gynecology at Tokushima University Hospital. PATIENT(S): One hundred seventy-eight cycles in patients undergoing ovarian hyperstimulation for IVF-ET were stimulated according to the scheduled method of ovarian hyperstimulation (scheduled group). One hundred seventy-one cycles in patients of similar age and with comparable causes of infertility were stimulated according to the conventional method of ovarian hyperstimulation for IVF-ET (conventional group). INTERVENTION(S): In the scheduled method, under GnRH-a, the day of oocyte retrieval was determined in advance for IVF-ET. Ovarian stimulation with FSH and hMG was started 12 days before oocyte retrieval. MAIN OUTCOME MEASURE(S): The cancellation and clinical pregnancy rates (PRs), the days of oocyte retrieval, and other clinical parameters were evaluated in the two groups. RESULT(S): The cancellation rates in the scheduled and conventional groups were 9.6% and 4.7%, respectively. In about 75% of cycles in the scheduled group, oocyte retrieval was conducted on the scheduled day. When oocyte retrieval was scheduled for Monday through Wednesday, overtime work on the weekend could be avoided in 91% of the cycles without cancellation. The clinical PR was comparable between the two groups. CONCLUSION(S): The scheduled method of ovarian hyperstimulation for IVF-ET was useful for avoiding oocyte retrieval on the weekend.

Adult↗
PubMed1997

In vivo and in vitro formation of morphinone from morphine in rat.

1. Morphinone, a toxic metabolite, and its glutathione adduct (MO-GSH) were identified in the bile of rat after subcutaneous injection of morphine (25 mg/kg) by hplc procedures. The amounts of morphinone and MO-GSH excreted in the 12-h bile were 0.8 +/- 0.3 and 8.4 +/- 4.3% respectively. 2. The 9000 g supernatants of rat, guinea pig, rabbit, mouse, hamster and bovine livers produced morphinone from morphine in the presence of either NAD+ or NADP+, NAD+ was a more efficient cofactor than NADP+ except in the guinea pig which equally utilized both cofactors. With NAD+ as cofactor, the amounts of morphinone formed in rat and guinea pig were 5.70 and 5.82 mumol/g liver/30 min respectively and were three-to-four times those in other species. 3. The enzyme activity responsible for formation of morphinone from morphine in the rat was almost exclusively distributed in the microsomal fraction, whereas guinea pig, hamster and bovine expressed the enzyme activity mainly in the cytosolic fraction. Rabbit and mouse gave higher activity in the cytosolic and microsomal fractions respectively, but other fractions of both species contained considerable activity. 4. The enzyme activities in male and female rat microsomes were characterized with respect to developmental pattern, kinetic parameters, pH dependency and susceptibility to inhibitors. 5. In conclusion the metabolism of morphine to morphinone in rat was confirmed by in vivo and in vitro experiments. It is also suggested that this pathway is a common route in morphine metabolism in several mammalian species.

Alcohol Oxidoreductases↗
PubMed1997

Retrovirus in salivary glands from patients with Sjögren's syndrome.

AIMS: To investigate the possibility of an immune response to retroviral antigens or of detecting retrovirus in Sjögren's syndrome. METHODS: Retroviruses were sought in labial salivary glands and peripheral blood mononuclear cells from patients with Sjögren's syndrome by immunoblotting assay, immunohistochemical assay, polymerase chain reaction (PCR), reverse transcriptase (RT) activity assay, and transmission electron microscopy. RESULTS: Sera from five of 15 patients with Sjögren's syndrome (33%) reacted against p24 group specific antigen (gag) of human immunodeficiency virus (HIV). Labial salivary gland biopsy specimens from seven of the 15 patients with Sjögren's syndrome (47%) contained an epithelial cytoplasmic protein reactive with a monoclonal antibody to p24 of HIV. PCR was performed to detect HIV and human T lymphotropic virus type I (HTLV-I) genes from salivary gland tissues and peripheral blood mononuclear cells from patients with Sjögren's syndrome. Mn2+ dependent, Mg2+ independent RT activity was detected in the salivary gland tissues in three of 10 patients. A-type-like retroviral particles were observed in epithelial cells of salivary glands by transmission electron microscopy. Target genes for HIV and HTLV-I were not found in any of the salivary gland tissues or peripheral blood mononuclear cells from Sjögren's syndrome patients. CONCLUSIONS: The data suggest the presence of an unknown retrovirus similar to HIV in the salivary gland which might be involved in the pathogenesis of a subpopulation in Sjögren's syndrome.

Adult↗
PubMed1997

[Relationship between carotid atherosclerosis and plasma endothelin-1 concentration in senile patients with hypertension].

The relationship between carotid atherosclerosis and plasma endothelin-1 (ET-1) concentration was studied in senile patients with essential hypertension. A total of 212 patients (83 M, 129 F; mean age, 63 years) with essential hypertension (WHO stage I-II), and 109 age-matched control subjects (mean age, 61 years) were enrolled in the study. The maximum thicknesses of the intima-media complex (IMTmax) in the right common carotid artery (CCA) and the right internal carotid artery (ICA) was measured by B-mode ultrasonography, and ET-1 was measured by enzyme immunoassay. ET-1 levels were significantly higher in the hypertensive patients than in the control subjects. In middle-aged patients (35-64 years old), IMTmax values of the ICA in patients with high ET-1 concentrations (ET-1 > or = 1.71 pg/ml) were significantly higher than in patients with normal ET-1 concentrations (ET-1 < 1.71 pg/ml). However, the IMTmax of the CCA did not show a similar correlation. In senile patients (65-83 years old), both the CCA and ICA IMTmax values were significantly higher in patients with high ET-1 concentrations than in those with normal ET-1 concentrations. These results indicate that high ET-1 levels in middle-aged patients with essential hypertension may play a role in the progression of ICA atherosclerosis. High ET-1 levels in senile patients with essential hypertension may cause progression of atherosclerosis in both the ICA and CCA.

Adult↗
PubMed1997

[Effects of atherogenic risk factors on asymptomatic brain infarct].

This study was done to clarify the relationship between asymptomatic brain infarcts and risk factors for atherogenis. A total of 312 patients (151 men and 161 women) who had no neurologic deficits were enrolled. Their ages ranged from 41 to 83 years (mean age 63 years). The patients were divided into two groups: 158 patients without asymptomatic brain infarct and 154 patients with at least one asymptomatic brain infarct of at least 5 mm as diagnosed by magnetic resonance imaging. The patients with asymptomatic brain infarct were more likely than those without asymptomatic brain infarct to be 65 years old or older, and to have essential hypertension, diabetes mellitus, or atrial fibrillation. Among patients with hypertension the frequency of left ventricular hypertrophy or hypertensive ocular findings (Scheie's class H2) was significantly higher in those with asymptomatic brain infarct than in those without asymptomatic brain infarct. These results indicate that aging, essential hypertension (especially with left ventricular hypertrophy or hypertensive ocular findings), diabetes mellitus, and atrial fibrillation are associated with asymptomatic brain infarct.

Adult↗
PubMed1997

[The relationship between brain atrophy and asymptomatic cerebral lesions].

In order to clarify the relationship between brain atrophy and asymptomatic cerebral lesions, total of 235 subjects (130 males and 105 females), who had neither neurologic deficits nor organic lesions on cerebral computed tomography, were studied. The subjects' ages ranged from 40 to 86 years (mean 66). They were divided into two groups: 90 controls without hypertension or diabetes mallitus (Group C), and 145 patients with essential hypertension (Group H). Brain atrophy was diagnosed using the caudate head index (CHI). Asymptomatic cerebral lesions on magnetic resonance imaging were defined as asymptomatic lacunae and white matter lesions. Caudate head index was higher in Group H than it was in Group C, and CHI in both groups was significantly correlated with the number of asymptomatic lacunae and the severity of white matter lesions on magnetic resonance imaging. These results indicate that brain atrophy may progress along with asymptomatic cerebral lesions.

Adult↗
PubMed1997

[Effects of long-term antihypertensive medication on common carotid hemodynamics in elderly patients with essential hypertension].

This longitudinal study was performed in order to clarify the effects of long-term antihypertensive medication on common carotid hemodynamics. A total of 84 patients (54 males and 30 females), who had been receiving treatment with antihypertensive medications for 5 years, were enrolled in this study. The subjects' ages ranged from 62 to 74 (mean 67). They were divided into three groups: 40 were treated with diuretics only (Group D), 28 with calcium antagonists only (Group C), and 16 with angiotensin converting enzyme inhibitors only (Group A). Mean blood flow volume (BF) and circulation resistance (Z) at the common carotid artery were measured by an ultrasonic quantitative flow measurement system. Blood flow volume, Z, and mean blood pressure (MBP) were measured twice over a 5-year period in patients and in 49 age-matched normal controls (Group N). Annual reductions in BF (delta BF) and MBP (delta MBP), and annual increases in Z (delta Z) were calculated. Blood flow volume of Group D showed larger decreases than that of the other three groups. Circulation resistance of Group C showed smaller increases than that of Group N. Reductions of BF and Z of Group A were similar to those of Group N. Reductions of Z of Group C showed a significant correlation with delta MBP. These results indicate that calcium antagonists may have beneficial effects on common carotid hemodynamics in elderly patients with essential hypertension.

Aged↗
PubMed1997

Prevalence, vasculature, and innervation of myocardial bridges in dogs.

OBJECTIVE: To report gross anatomic examination of the canine myocardial bridge (MB), a muscular band found above the coronary artery (CA), with respect to its occurrence, location, vascularization, and innervation. SAMPLE POPULATION: 629 canine hearts obtained within 1 to 3 hours after euthanasia. PROCEDURE: After an incision was made at the left fifth intercostal space, the pericardial sac was cut open, and if an MB was present, the heart, lungs, and annexed structures were removed together and subsequently subjected to macroscopic examination of MB musculature and innervation after formalin fixation. Vascular casting was performed by use of methyl methacrylate perfusion. RESULTS: Of the 629 canine hearts examined, 189 (30%) had MB, occurrence of which was independent of sex, age, and breed. Among 13 MB-containing specimens examined in detail, there was great variation in thickness (0.11 to 2.24 mm; mean, 0.45 mm) of MB and distance (24 to 236 microns; mean, 103 microns) between the MB and the paraconal interventricular branch of the left CA (PIBL). One pair or 2 pairs of blood vessels from the PIBL supplied the MB muscle. Venous blood returned to the coronary circulation via the branches of the great coronary vein coursing on both sides of the PIBL, in close contact with the PIBL and the groove wall. The 2 veins rejoined at the upper portion of the PIBL and passed obliquely to the coronary groove under the left auricle, and finally drained the blood through the coronary sinus into the right ventricle. Innervation to the MB muscle was derived from nerve branches of the middle cervical ganglion and left vagus nerve. CONCLUSION: Prevalence and localization of MB in dogs and human beings are similar. Vascularization of the MB muscle originates from the PIBL. The cervical ganglion and vagus nerve control the MB muscle.

Age Factors↗
PubMed1997

[Estrogen, progesterone--biosynthesis, receptor and action].

Ovarian sex steroid hormones, estrogen and progesterone, have crucial effects on female reproductive functions such as the development and maturation of reproductive organs and the appearance of normal menstrual cycles. The precursor of steroid hormones is a cholesterol that is synthesized de novo from acetate or that is taken in as LDL-cholesterol via LDL-receptor. Members of cytochrome P450 superfamily and hydroxysteroid dehydrogenase (HSD) involved in the biosynthesis of the steroid hormones. In the corpus luteum, P450scc and 3 beta-HSD catalyze the pathway from cholesterol to progesterone and in the granulosa cells, P450arom (aromatase) and two HSDs catalyze the biosynthesis of estrogen from C19 steroid synthesized in the theca cells having P450(17) alpha. In the target cell, steroid binds to and activates its receptor located primarily in the nucleus. Binding of ligand results in dimerization of the receptor due to its conformational change. The steroid-receptor complex binds to specific hormone responsive element of the target gene at the site of DNA binding region and then activates transcription of the gene. Main action of estrogen is to stimulate the proliferation and development of cells due to enhancement of the synthesis of specific DNAs and proteins in the female reproductive organs. Progesterone regulates the action of estrogen through the decrease of estrogen receptor and down regulation of its own receptor.

Estrogens↗
PubMed1996

Cardiac rod body: hypertrophic Z-line in an aged pony.

Numerous rod bodies were found in a heart sample from a 33-year-old pony by a conventional electron-microscopic technique. The rod bodies were concentrated in localized areas of both atria and ventricles, without a specific pattern of distribution. The rods appear to have a typical crystalline-like structure which presumably contains actin backbone filaments and alpha-actinin as major protein constituents. Diminution, fragmentation, and disorganization of the myofibrils, random expansion of electron-dense materials, especially at the fasciae adherens of the intercalated disc, an increase of intercellular space, frequently associated with connective tissue elements, and accumulation of glycogen granules, lipofuscin, mitochondria, and nonviable organelles in the rod body-containing cells suggested that rod-containing myocytes are in a degenerating stage and that rod body formation occurs in atrophic cardiomyocytes rather than normal or hypertrophic cardiomyocytes in the aged pony heart.

Aging↗
PubMed1995

High implantation rate and consequently high pregnancy rate by in vitro fertilization-embryo transfer treatment in infertile women with antisperm antibody.

OBJECTIVE: To examine the effect of antisperm immunity on postfertilization steps, such as implantation of embryos and fetal growth in IVF-ET treatment of women with sperm-immobilizing antibodies. DESIGN: Retrospective analysis of clinical laboratory data. SETTING: The IVF-ET program of the Department of Obstetrics and Gynecology. The University of Tokushima, School of Medicine. PATIENTS: Eighteen women with sperm-immobilizing antibodies and 122 infertile patients with nonimmune etiology as controls. Infertile couples due to a male factor and with unknown etiology were excluded. INTERVENTIONS: All patients received the same IVF-ET program with GnRH agonist. MAIN OUTCOME MEASURES: Rates of fertilization and cleavage, implantation rate per embryo transferred and pregnancy rate (PR) in both test and comparison groups. RESULTS: The rate of fertilization in the antisperm group (61.3%) was significantly lower than that in the comparison group (76.8%). But the implantation rate per embryo transferred (23.5%) and consequently the modified PR per oocyte recovery procedure (34.4%) in immunologically infertile women were significantly higher than those in the comparison group (7.9% and 17.8%, respectively). CONCLUSIONS: Although sperm-immobilizing antibodies prevent sperm-egg interaction, they do not seem to have any adverse effects on achievement of pregnancy. Moreover, the existence of antisperm immunity in woman with antisperm antibodies is suggested to be favorable for successful pregnancy by the IVF-ET procedure.

Adult↗
PubMed1995

Hypertrophic Z-line observed in aged one-humped camel (Camelus dromedarius).

The ultrastructure of cardiac muscle from 3 aged one-humped camels (Camelus dromedarius) was examined to see if aged camels also develop hypertrophic Z-lines as observed in the heart of aged humans and other animals. The results proved that the aged camel heart develops hypertrophic Z-lines together with other age-associated alterations, including loss of myofibrils and myofilaments, increase of intermyofibrillar spaces and intercellular spaces, and disruption of mitochondrial cristae and intercalated disc structure. Hypertrophic Z-lines are somewhat smaller than those of other species, but occur both in the atria and ventricles. Although the majority of cardiac muscle samples revealed a normal structure, the finding of hypertrophic Z-lines in camel heart is the first such observation in a ruminant animal. The anomalous camel muscle resembles that of other species in terms of cell alterations commonly associated with aged hearts.

Aging↗
PubMed1995

[Immunohistochemical study of the endomyocardial biopsy of systemic lupus erythematosus].

The mechanisms of cardiac involvement in systemic lupus erythematosus (SLE) were studied using immunohistochemical staining of endomyocardial biopsy specimens from 14 patients with SLE and normal coronary arteriograms. All 14 specimens showed mild interstitial edema, 11 showed mild cardiac fibrosis, and another two cases showed moderate cardiac fibrosis with myocardial derangements. Four specimens showed moderate cell infiltration in the interstitium. Area of fibrosis, diameter of myocardium and area of interstitial edema were increased in the SLE patients compared to the control cases. Immunofluorescence showed IgG and fibrinogen deposition in the membrane of cardiac myocytes and in the interstitium. Immunohistochemistry found no B lymphocytes in any of the seven SLE cases. T lymphocytes were observed in all seven SLE cases, and OKT 8 lymphocytes were increased significantly in the interstitial tissue as compared with OKT 4 lymphocytes. At endomyocardial biopsy, all 14 patients were receiving corticosteroid therapy and had low activity disease. The results suggest that cardiac tissue damage was associated with immunological abnormalities and might progress silently under conditions in which the disease activity was suppressed by corticosteroid therapy.

Adult↗
PubMed1995

[Detection of retrovirus in salivary glands of patients with Sjögren's syndrome].

As similar symptoms and glandular pathology are observed in certain persons infected with human immunodeficiency virus (HIV) and human T lymphotropic virus type I (HTLV-I), a search was initiated for a possible retroviral etiology in Sjögren's syndrome (SS). Sera from 33% of 15 SS patients reacted against p24 (gag) of HIV. Salivary gland (SG) biopsy specimens from 47% of the 15 SS patients contained an epithelial cytoplasmic protein, reactive with a monoclonal antibody to p24 of HIV. We also detected Mn2+ dependent, Mg2+ independent reverse transcriptase activity in the SG 3 of 10 SS patients. Target genes for HIV and HTLV-I were not found in any of the SG or peripheral blood mononuclear cells from SS patients. These data suggest the presence of an unknown retrovirus, similar to HIV, in the SG, which could contribute to the chronic inflammation of SS.

Animals↗
PubMed1994

Effect of lysophosphatidic acid on the preimplantation development of mouse embryos.

The effect of lysophosphatidic acid (LPA) on the preimplantation development of mouse embryos was examined. The blastocyst rates from 2-cell and 4-cell stage embryos were significantly higher in the presence of LPA at the pronuclear stage. However, the blastocyst rate from 4-cell stage embryos was significantly lower when LPA was added to the medium at the 4-cell stage than when it was added at the pronuclear stage. Furthermore, pretreatment of pronuclear stage embryos with pertussis toxin suppressed LPA-induced embryo development, suggesting that it is probably mediated by a Gi-protein-linked receptor.

Animals↗