Biomedical subjects

T Aono

Publications and source records attributed to T Aono.

At least 109 records · Page 6Linked to original sources

PubMed1997

Peculiar archaea found in Japanese paddy soils.

Archaeal 16S rDNA clones retrieved from paddy soil DNA were sequenced. Among 100 clones, 88 clones were assigned to methanogens and nine clones were assigned to crenarchaeota. However, three of the nine clones were phylogenetically far from the cultured crenarchaeota and closely related to marine planktonic archaea. The other three clones showed extremely novel 16S rDNA sequences and were phylogenetically far from both Crenarchaeola and Euryarchaeota. This paper reports the ubiquitous presence of crenarchaeotal and extremely novel clones in paddy soils.

Archaea↗

PubMed1997

Immunological functions of adult T cell leukemia cells of a patient complicated with synchronous double primary gynecologic cancer.

A patient with triple malignancies is reported, who presented cervical cancer, vulvar cancer and adult T cell leukemia (ATL). ATL was diagnosed as a smouldering type, because antibody to human T cell leukemia virus associated antigen (ATLA) was positive with a titer of 1:160. Although her malignant cells had an OKT 4+8-3+Tac+ phenotype, the cells did not display helper T cell functions. Namely they showed no response to Phytohemagglutinin (PHA) and Interleukin 2 (IL-2) and suppressed the PWM driven IgG synthesis of B cells obtained from healthy donor. They did not produce IL-2 by stimulation with PHA and phorbol myristate acetate (PMA). Furthermore, these ATL cells were producing IL-2 inhibitor like factors. As synchronous triple malignancies are extremely rare, two gynecologic cancers seem to ascribe to the suppressing state of the immunosurveillance mechanism by viral infection.

Aged↗

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↗

PubMed1997

[Physiology and action of prolactin].

Prolactin (PRL) is a peptide hormone secreted by the lactotroph of the anterior pituitary. Secretion of PRL is regulated negatively by hypothalamic hormone. Dopamine is the major physiologic prolactin inhibiting factor (PIF). PRFs as TRH, VIP and oxytosin have prolactin releasing activity. Prolactin secretion is induced by sleep, stress, sexual intercourse and suckling stimulus. Serum level of PRL is increased by estrogen. Therefore, PRL level is higher in women, especially in the late follicular phase and during pregnancy. Lactation is the major biologic function of PRL in humans and essential to reproduction. Other function of PRL, such as regulation of ovarian function, osmoregulation and immunoregulation is not fully established. Many action of PRL remained to be clarified.

Adolescent↗

PubMed1996

Suppression of hepatic portal blood flow caused by carbon dioxide pneumoperitoneum can be restored after dopamine administration in pigs.

Portal venous blood flow (PVF), hepatic arterial blood flow (HAF) and systemic arterial pressure (SAP) were examined after dopamine (DA) injection into the jugular vein under carbon dioxide pneumoperitoneum in pigs. When intraabdominal pressure (IAP) was increased by 12 mmHg, PVF and HAF were reduced, but SAP was unchanged. When IAP was kept at 12 mmHg, the injection of DA at 10 micrograms/kg/min for 2 min produced an increase in PVF without causing any change in HAF or SAP. The response in PVF was dose-dependent. When IAP was increased to 16 mmHg, PVF response was diminished, and no change in HAF or SAP was seen at the same dose of DA. These observations suggest that DA is effective in increasing PVF under enhanced IAP conditions, but such circulatory improvement due to the agent would be prominent when IAP is below 12 mmHg.

Animals↗

PubMed1996

Expression of Tn and sialyl-Tn antigens in the neoplastic transformation of uterine cervical epithelial cells.

The expression of simple mucin-type carbohydrate antigens, Tn and sialyl-Tn antigens, was evaluated by immunohistochemical staining with monoclonal antibodies in normal squamous epithelium, dysplasia, carcinoma in situ, and invasive squamous cell carcinoma of the uterine cervix. The expression of the Tn antigen detected by HB-Tn1 and B1.1 was found in 17 (20%) and 19 (23%) of the 83 invasive carcinomas, respectively, but was not found in the 36 normal squamous epithelia, 22 severe dysplasias, or 24 carcinomas in situ. The sialyl-Tn antigen was detected by HB-STn1 and TKH-2 in 14 (64%) and 11 (50%) of the 22 severe dysplasias, 13 (54%) and 10 (42%) of the 24 carcinomas in situ and 48 (58%) and 42 (51%) of the 83 invasive carcinomas, respectively, but was completely absent in 36 normal squamous epithelia. Coexpression of the sialyl-Tn antigen was observed in 89% of the cases expressing the Tn antigen. No significant difference was observed between the immunoreactivities of the antigens in the metastatic lymph nodes and primary tumors. No correlation was found between the expression of each antigen and clinical state, histologic type, depth of invasion, parametrial spread, lymphatic and vessel permeation, lymph node metastasis, or 5-year survival rate. The expression of Tn and sialyl-Tn demonstrates a specific change in the neoplastic progression from carcinoma in situ to invasive carcinoma and from normal to dysplasia, respectively, in squamous cell neoplastic lesions of the cervix. Tn and sialyl-Tn antigens may be useful markers for biologic investigation of neoplastic transformation in cervical squamous cell carcinoma.

Antigens, Tumor-Associated, Carbohydrate↗

PubMed1996

Indocyanine green disappearance enhanced by prostaglandin E1 in patients with hepatic resection.

Indocyanine green (ICG) is a reliable indicator reflecting hepatocyte function and hepatic blood flow. Prostaglandin E1 (PGE) has been indicated to increase hepatic blood flow and protect the hepatocyte. The purpose of this study is to investigate whether PGE influences the ICG disappearance rate in patients with hepatic resection. Eleven patients with hepatic resection were divided into two groups according to the presence of liver cirrhosis (LC, n = 4) and chronic hepatitis (CH, n = 7). ICG 0.1 mg/kg was given as an intravenous bolus into the cubital vein 5 min after PGE administration, then the disappearance rate of ICG (ICG-K) was determined by a finger monitoring method. PGE administration increased ICG-K in the LC and CH groups with normal liver function, and the ICG-K response was dose dependent when the dosage of PGE ranged from 0.01 to 0.05 microg/kg/min. When ICG-K relative to the ICG-K of the control was defined as the ICG-K ratio, the daily course of the ratio in the LC group was higher than in the CH group. PGE increases the ICG-K of patients with normal liver function before and after hepatic resection, and this is evident in the case of liver cirrhosis.

Aged↗

PubMed1996

Hepatocellular carcinoma associated with precirrhotic primary biliary cirrhosis successfully treated by a right hepatic lobectomy: report of a case.

We report herein the case of a 69-year-old woman in whom hepatocellular carcinoma (HCC) arising in the precirrhotic phase of primary biliary cirrhosis (PBC) was successfully managed by a right hepatic lobectomy. The patient, who had never received a blood transfusion, had a 4-year history of asymptomatic PBC of Scheuer's histological classification stage II. Abdominal computed tomography (CT) revealed a mass measuring 4.0 cm in the right hepatic lobe, and a right hepatic lobectomy was performed in consideration of her good liver function and the deep location of the tumor in the right lobe. The patient has remained well without any evidence of recurrent disease for 4 years since her operation. A review of the literature revealed only two cases of successful partial hepatectomy, but none of major hepatectomy. Most of the reported cases had been treated with transcatheter arterial embolization (TAE) and were associated with poor survival. Our experience of this patient indicates the potential value of hepatectomy as an alternative to TAE in selected patients with resectable disease and good hepatic function.

Aged↗

PubMed1996

Effect of prostaglandin E1 on ammonia concentration in blood of patients with hepatic resection.

Plasma concentrations of ammonia were examined following prostaglandin E1 (PGE1) administration in 16 patients who received hepatectomy for hepatocellular carcinoma. PGE1 at 0.01-0.04 microgram/kg/min was administered for approximately 24 hr during the perioperative periods. The ammonia concentration was reduced a day after the operation following intravenous administration of PGE1 in cirrhotic patients compared to noncirrhotic patients with or without PGE1 injection. Serum liver function scores, glutamic pyruvic transaminase, and total bilirubin concentrations were decreased after PGE1 administration. A similar ammonia response due to PGE1 was obtained after operation in cirrhotic patient when PGE1 0.5 microgram/kg was administered intravenously for 30 min. These results suggest that PGE1 administration is useful in reducing the enhanced ammonia concentration associated with hepatic resection, and it is particularly effective in the case of liver cirrhosis.

Alanine Transaminase↗

PubMed1996

Inducible nitric oxide synthase in uterine smooth muscle.

The expression of inducible nitric oxide synthase (iNOS) mRNA in rat uterus upon in vivo stimulation with lipopolysaccharide (LPS) was studied by reverse transcription and polymerase chain reaction. The injection of LPS induced an increase in mRNA levels of a macrophage-type iNOS. In unstimulated rats, low levels of iNOS mRNA was detected in the uterus and lungs, but absent or negligible in the kidneys and liver. NO was produced in the LPS-treated uterus by addition of 1 to 1000 microM L-arginine. The production of NO in uterine tissue that faces the outside of the body may provide a bacteriocidal protective function against microorganisms in physiological condition. However, NO produced in a large amounts by cytokine and LPS may play some pathological reaction during septic shock or infection.

Animals↗

PubMed1996

Transvaginal power Doppler angiography of the fetal brain.

Using transvaginal B-mode sonography combined with power Doppler flow mapping on a total of 65 fetuses between 12 and 30 weeks of gestation, fetal intracerebral arteries and veins and blood flow were demonstrated in the coronal and sagittal planes. Clear images of the fetal brain and intracerebral vascular flow were obtained in 36 of the 65 cases. Bilateral vertebral arteries, the basilar artery and posterior cerebral arteries were imaged in the coronal plane at 12 weeks of gestation. Bilateral carotid and middle cerebral arteries were also depicted in the coronal plane at 13 weeks of gestation. The middle cerebral arteries and their branches were depicted via the anterior fontanelle in the coronal plane at 20 weeks of gestation. The anterior cerebral artery and its branches were demonstrated in the sagittal plane at 26 weeks of gestation. The fetal cerebral venous systems of the superior sagittal sinus, internal cerebral vein, vein of Galen and straight sinus were clearly imaged in the mid-sagittal plane. Although we encountered several problems with this new technology of transvaginal power Doppler sonography, we were able to demonstrate its potential to assess fetal intracranial blood flow during pregnancy.

Blood Flow Velocity↗

PubMed1996

Hyperleptinemia in chronic renal failure.

To investigate the mechanism(s) of degradation of leptin, the protein product of ob (obese) gene, we measured serum leptin levels in 70 patients with chronic renal failure (CRF). The median of serum leptin concentrations of 36 male and 34 female patients with CRF were 7.3 ng/ml ranging from 0.5 to 39.0 ng/ml and 34.9 ng/ml from 1.1 to 76.1 ng/ml, respectively, while those of 29 male and 29 female healthy subjects were 5.8 ng/ml ranging from 0.5 to 37.7 ng/ml and 12.0 ng/ml from 2.0 to 45.2 ng/ml, respectively. The difference in male and female serum leptin concentrations between CRF group and the normal counterpart was statistically significant (p<0.005 and p<0.05, respectively). However, there was no significant correlation, either between serum creatinine or BUN, and serum leptin concentrations. These findings suggest that leptin is degraded and/or filtered in renal tissue.

Adult↗

PubMed1996

Effect of IL-1 in amniotic fluid on the fetal keratinocyte.

IL-1 alpha is predominantly increased in amniotic fluid of the patients with premature rupture of the membrane (PROM). In the present study we examined the effect of IL-1 on the fetal keratinocytes, one of the main tissue exposed to the increased IL-1. Exposure of IL-1 at over 0.1 pg/ml IL-1 significantly (p < 0.01) inhibited proliferation of the keratinocytes in low calcium keratinocyte growth medium obtained from the umbilical cord. Immunohistochemical analysis using antibodies to various cytokeratins revealed that the umbilical cord keratinocytes is more similar to the mucosal epithelium than the skin epithelium. These results suggest that IL-1 alpha increased in amniotic fluid in the PROM cases leads the immature proliferating mucosal epithelium to maturate for protection of the fetus against environment.

Amniotic Fluid↗

PubMed1996

In vivo biological activity of antioxidative aminothiazole derivatives.

For the development of novel antioxidants having therapeutic utility, a new series of condensed 4- and 5-aminothiazole derivatives has been synthesized using simple methods. Condensed 4-aminothiazoles were prepared by the reaction of alpha-bromolactams with thioamides in ethanol and 5-aminothiazole derivatives were obtained by the treatment of 3-(acylamino)lactams with a thiating agent such as phosphorous pentasulfide and Lawesson's reagent in pyridine. In vitro assay of the condensed 5-aminothiazole derivatives showed them to be potent inhibitors of lipid peroxidation. In order to evaluate these compounds in an in vivo system, we devised a simple and reproducible method in which the inhibition of characteristic behaviors induced by spinal injection of FeCl2 was expressed numerically. Compounds having strong in vitro activity protected the central nervous system form injury caused by iron-dependent lipid peroxidation. The results suggest that the in vivo assay developed in this study should be useful as a screening method for antioxidants and also that condensed 5-aminothiazole derivatives are promising candidates for the treatment of traumatic and ischemic injury of the central nervous system.

Animals↗

PubMed1996

Power spectral analysis of spontaneous blood pressure and heart rate variability in elderly hypertensives.

To examine the influence of hypertension on cardiovascular variability in elderly subjects, we measured spontaneous beat-to-beat blood pressure (BPV) and heart rate variability (HRV) in elderly subjects with or without hypertension at rest and during tilting. The study group consisted of 23 community-dwelling, male elderly subjects (aged 62-75 years) and was divided into two groups, i.e., a hypertensive group (HT group; n = 11) and normotensive group (NT group; n = 12). According to the modeling and decomposing algorithm of an autoregressive process, we estimated the component power of low-frequency (LF; 0.03-0.15 Hz) and high-frequency components (HF; respiratory frequency) of BPV and HRV by power spectral analysis. We also measured plasma norepinephrine (PNE) levels in the two groups at rest and during tilting. In the HT group, we found that the amplitude of LF-BPV was greater (p < 0.05) and its relative change by postural tilting was smaller (p < 0.05) than those in the NT group. We found no significant difference in the amplitude of LF-HRV and HF-HRV between the two groups, and found no significant response of the amplitude of LF-HRV and HF-HRV to postural tilting. We also found no difference in PNE level between the two groups at rest or during tilting. These results suggest that the regulatory function of sympathetic vasomotor activity assessed by power spectral analysis of BPV is altered in hypertensive elderly subjects, although the influence of hypertension on the autonomic control of the heart is less dominant in the elderly.

Aged↗

PubMed1996

Arachidonate 12-lipoxygenase in porcine anterior pituitary cells: its localization and possible function in gonadotrophs.

Arachidonate 12-lipoxygenase, which oxygenates positions 12 and 13 of arachidonic and linoleic acids, is present in porcine anterior pituitary cells. Colocalization of the 12-lipoxygenase with various pituitary hormones was examined by immunohistochemical double-staining using antibodies against 12-lipoxygenase and various anterior pituitary hormones. Under light microscopy, approximately 7% of the cells producing luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were positive for 12-lipoxygenase, whereas the enzyme was detected in less than 2% of the cells producing thyrotrophin, prolactin, growth hormone (GH), and adrenocorticotrophin. In an attempt to examine the participation of 12-lipoxygenase metabolites in pituitary hormone release, we incubated the primary culture of porcine anterior pituitary cells with 12-hydroperoxy-arachidonic acid or 13-hydroperoxy-linoleic acid. Significant stimulation of LH and FSH release by these hydroperoxides was observed at 10 microM in a time-dependent manner. At doses around 10 microM these compounds produced responses of similar magnitude to 1 nM gonadotrophin-releasing hormone (GnRH), but higher concentrations (30 microM) of the compounds were required for GH release. In contrast, 12-hydroxy-arachidonic and 13-hydroxy-linoleic acids were almost ineffective. Furthermore, the gonadotrophin release by 1 nM GnRH was inhibited by nordihydroguaiaretic acid (a lipoxygenase inhibitor) with an IC50 of about 5 microM. Thus, the hydroperoxy (but not hydroxy) products of 12-lipoxygenase may be involved in the release of pituitary hormones especially LH and FSH.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗

PubMed1996

[The effect of ACE inhibitors, beta blockers and calcium antagonists on the responses to pressor stress tests in the elderly hypertensive patients].

The purpose of the study was to elucidate the effects of antihypertensive drugs on the hemodynamics in elderly hypertensive patients. Forty-two elderly hypertensives (mean 72 +/- 5 years) were given either ACE inhibitors (A group: perindopril in 10 and captopril in 4 cases), beta blockers (B group: arotinolol in 15 cases) or calcium antagonists (C group: nifedipine in 3 and nitrendipine in 10 cases) for 8-12 weeks. The responses to handgrip and mental arithmetic stress and cardiac functional changes were determined by echocardiography before and after the medications. The decrease in blood pressure at rest and on the stress tests was similar among the three groups, though the hemodynamic responses to the stress tests showed some differences. In the A group, no hemodynamic changes were seen either at rest or on the stress tests after the medication. In the B group, the heart rate and the cardiac output were decreased at rest, and the increase of them on the stress tests were diminished after the medication. On the contrary, the heart rate and the cardiac output were increased, and showed exaggerated responses on the stress tests in the C group. In conclusion, in antihypertensive treatment of elderly hypertensive patients it is important to consider the effects of the antihypertensive drugs on the hemodynamics, although the comparable decrease in blood pressure is expected.

Adrenergic beta-Antagonists↗

PubMed1996

[Circadian variation in blood pressure in elderly hypertensive patients].

We studied circadian variation in blood pressure in elderly patients with hypertension, using three criteria for "non-dipper". Ambulatory blood pressure monitoring was done in 107 elderly outpatients whose average 24-hour systolic blood pressure was greater than 140 mmHg. Daytime was distinguished from nighttime by the level of physical activity as measured with an activity sensor and a questionnaire. The three criteria for "non-dipper" were as follows: 1. A nocturnal decline in systolic blood pressure that was less than 10% of the daytime average blood pressure. 2. A nocturnal decline in systolic blood pressure that was less than 10 mmHg. 3. A nighttime average systolic blood pressure that was greater than the daytime average systolic blood pressure. The nocturnal decrease in blood pressure was smaller in older patients than in younger patients. In patients over 80 years old, it was 6.0 mmHg (p < 0.05, as compared with patients aged 60-69 and with patients aged 70-79). The percentages of patients classified as "non-dippers" according to the criteria listed above were 53.3%, 37.4%, and 15.9%, respectively. Older patients were more likely than younger patients to be classified as "non-dippers". When defined according to criterion # 1, "non-dippers" made up 83.3% of those over 80 years old. These results was consistent with a continuous age-related decline in neuroendocrine regulation involving both peripheral and central nervous system.

Aged↗